(19)
(11)EP 3 223 009 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.07.2020 Bulletin 2020/31

(21)Application number: 17162909.0

(22)Date of filing:  24.03.2017
(51)International Patent Classification (IPC): 
G01N 27/407(2006.01)
G01N 27/417(2006.01)

(54)

GAS SENSOR MANUFACTURING METHOD AND GAS SENSOR MANUFACTURING APPARATUS

GASSENSORHERSTELLUNGSVERFAHREN UND GASSENSORHERSTELLUNGSVORRICHTUNG

PROCÉDÉ ET APPAREIL DE FABRICATION DE CAPTEUR DE GAZ


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 25.03.2016 JP 2016061512

(43)Date of publication of application:
27.09.2017 Bulletin 2017/39

(73)Proprietor: NGK Insulators, Ltd.
Nagoya-city, Aichi 467-8530 (JP)

(72)Inventors:
  • ISAKA, Kenji
    Nagoya-city, Aichi 467-8530 (JP)
  • EGAWA, Koji
    Nagoya-city, Aichi 467-8530 (JP)
  • IKOMA, Nobukazu
    Nagoya-city, Aichi 467-8530 (JP)

(74)Representative: Mewburn Ellis LLP 
Aurora Building Counterslip
Bristol BS1 6BX
Bristol BS1 6BX (GB)


(56)References cited: : 
EP-A1- 2 730 917
EP-A1- 3 093 655
US-A1- 2005 022 361
EP-A1- 2 784 498
JP-A- 2008 145 339
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION


    Field of the invention



    [0001] The present invention relates to a method for manufacturing a gas sensor including a ceramic sensor element.

    Description of the Background Art



    [0002] Conventionally, there have been well known gas sensors having sensor elements formed from an oxygen-ion conductive solid electrolyte ceramic, such as zirconia (ZrO2), as devices for determining the concentrations of predetermined gas components in measurement gas, such as combustion gasses and exhaust gasses in internal combustion engines such as automobile engines.

    [0003] Such gas sensors generally include a sensor element (detection element) with an elongated plate shape which is made of a ceramic, wherein the sensor element is secured by a plurality of ceramic supporters which are ceramic insulators and by powder compacts made of ceramics such as talc which are embedded between the ceramic supporters, in a hollow portion of a metal housing and a cylindrical inner tube secured thereto through welding, so that the powder compacts provide hermetic sealing between a space on one end side of the sensor element and a space on the other end side of the sensor element. The hermetic sealing is achieved by pressing the ceramic supporters and the powder compacts which are sequentially and annularly mounted to the sensor element using a predetermined sealing jig to compress the powder compacts, and subsequently swaging the inner tube from outside using a predetermined swaging jig (refer to Japanese Patent Application Laid-Open No. 2015-169606, for example).

    [0004] In order to secure airtightness with the hermetic sealing described above, a pressing by a sealing jig needs to be performed with a relatively high load of 400 kgf or more, for example. In addition, the sensor element needs to be disposed in a correct position in a correct attitude after the hermetic sealing so that the gas sensor satisfies desired characteristics.

    [0005] If the sensor element is inclined and comes in contact with the ceramic supporters at the time of the sealing, thereby being subjected to an action of a stress from the ceramic supporters, a crack may occur in a portion of the sensor element being in contact with the ceramic supporters in a process of manufacture or in use, or the sensor element may be broken at the contact portion. In a manufacturing process, it is required that a generation of such a defective product is reduced and, if the defective product is generated, it needs to be reliably found and excluded from a shipping object.

    SUMMARY OF THE INVENTION



    [0006] The present invention relates to a method for manufacturing a gas sensor including a ceramic sensor element and, more particularly, is directed to a suppression of breakage failure of the element at a time of assembly.

    [0007] According to the present invention, a method for manufacturing a gas sensor, the method including a step of obtaining an assembled body constituting the gas sensor by performing a predetermined processing on a semi-assembled body which is manufactured in advance, and the semi-assembled body includes: an annular-mounted assembly in which a plurality of annularly-mounted members, at least one of which is a ceramic powder compact, each having a disc shape or cylindrical shape are annularly mounted to a sensor element with an elongated plate shape which is mainly made of a ceramic; and a tubular body which is annularly mounted to an outer periphery of the annularly-mounted members and capable of engaging one end side of the annularly-mounted members therein. The step of obtaining the assembled body includes steps of: a) causing one end of the sensor element constituting the semi-assembled body to abut to a predetermined positioning member for positioning the sensor element; and b) applying a first force to the annularly-mounted members from the other end side of the sensor element having been positioned through the step a) and thereby compressing the powder compact so as to fix the sensor element inside of the tubular body, wherein the step b) is performed while constraining the sensor element in a predetermined constraining region in the other end side of the sensor element.

    [0008] According to the present invention, an occurrence of a breakage failure of the element inside the assembled body, which constitutes the main body of the gas sensor, can be appropriately suppressed, so that a generation of a defective product in the gas sensor is suppressed.

    [0009] Preferably, in the method for manufacturing the gas sensor of the present invention, the step of obtaining the assembled body further includes a step of: c) after the step b), applying a second force which is larger than the first force to the annularly-mounted members from the other end side of the sensor element with the one end of the sensor element not abutting to the positioning member and thereby further compressing the powder compact so as to hermetically seal between spaces located on one end side and the other end side of the sensor element inside of the tubular body.

    [0010] In this case, the second compression for the hermetic sealing between the spaces located on one end side and the other end side of the sensor element inside of the tubular body is successively performed subsequent to the first compression performed mainly for purpose of positioning the sensor element, without using the element positioning member, so that the hermetic sealing can be achieved without a chip or break in the sensor element.

    [0011] Alternatively, preferably, in the method for manufacturing the gas sensor of the present invention, the annularly-mounted members include a washer, and the method further includes steps of: f) obtaining an inclination amount of the washer in a state where the assembled body is in the assembly posture; and g) determining that the assembled body is a defective product when the inclination amount exceeds a predetermined threshold value.

    [0012] In this case, the usage of the assembled body having the breakage failure of the element due to the washer inclination or holding a potential of it in the future, to the gas sensor can be appropriately prevented.

    [0013] Accordingly, the object of the present invention is to provide a method for manufacturing a gas sensor which suppresses a generation of a defective product caused by an improper posture of the sensor element inside the gas sensor.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0014] 

    Fig. 1 is a perspective view of an external appearance of a gas sensor 1.

    Fig. 2 is a partial cross-sectional view illustrating a main structure inside the gas sensor 1.

    Figs. 3A to 3C are views for describing details of an electrode terminal 13 of a sensor element 10.

    Fig. 4 is a view exemplifying a heater structure included in the sensor element 10.

    Fig. 5 is a view schematically illustrating a procedure of manufacturing and inspecting an assembled body 40.

    Fig. 6 is a block diagram schematically illustrating a structure of a manufacturing apparatus 100.

    Figs. 7A to 7C are views schematically illustrating a-semi-assembled body assembling process.

    Fig. 8 is a planar view schematically illustrating a transport of a-semi-assembled body 40α and the assembled body 40 in a transportation part 110 and a delivery of the semi-assembled body 40α between the transportation part 110 and respective parts.

    Fig. 9 is a view illustrating a more specific procedure of a tentative sealing process.

    Fig. 10 is a side view schematically illustrating a structure of a tentative sealing processing part 130.

    Figs. 11A and 11B are views for describing an element constraining jig 133.

    Figs. 12A and 12B are views illustrating a state halfway through the tentative sealing process in stages.

    Figs. 13A and 13B are views illustrating a state halfway through the tentative sealing process in stages.

    Figs. 14A to 14C are cross-sectional views of a main part of the assembled body 40 for describing an effect of formation of a constraining region 133e at the time of the tentative sealing.

    Fig. 15 is a view describing how to evaluate a misalignment of the sensor element 10 in the assembled body 40.

    Fig. 16 is a view exemplifying an effect of the element constraining jig 133.

    Fig. 17 is a view illustrating a more specific procedure of a main sealing process and a first swaging process.

    Fig. 18 is a side view schematically illustrating a structure of a main sealing/swaging processing part 140.

    Fig. 19 is a view illustrating a state halfway through the main sealing process in stages.

    Fig. 20 is a view illustrating a state halfway through the main sealing process in stages.

    Figs. 21A and 21B are views for describing an operation of a swaging jig movement mechanism 143m at the time of the first swaging.

    Fig. 22 is a view illustrating a state halfway through the first swaging process in stages.

    Fig. 23 is a view illustrating a state halfway through the first swaging process in stages.

    Fig. 24 is a view illustrating a state halfway through the first swaging process in stages.

    Fig. 25 is a view illustrating a more specific procedure of a second swaging process.

    Fig. 26 is a side view schematically illustrating a structure of a retightening processing part 150.

    Fig. 27 is a view illustrating a state halfway through the second swaging process in stages.

    Fig. 28 is a view illustrating a state halfway through the second swaging process in stages.

    Fig. 29 is a view illustrating a state halfway through the second swaging process in stages.

    Fig. 30 is a view illustrating a state halfway through the second swaging process in stages.

    Fig. 31 is a view exemplifying a structure of an impact test apparatus 1000 of the assembled body 40.

    Fig. 32 is a view exemplifying a result of an impact test performed using the impact test apparatus 1000.

    Fig. 33 is a view illustrating a more specific procedure of a washer inclination inspection process and a subsequent continuity inspection process.

    Fig. 34 is a side view schematically illustrating a structure of an inspection processing part 160.

    Figs. 35A and 35B are views more specifically illustrating a positional relationship of constituent elements of the inspection processing part 160 at a time of starting the inspection process.

    Figs. 36A and 36B are views illustrating a state halfway through the washer inclination inspection process.

    Fig. 37 is a view illustrating a state halfway through the washer inclination inspection process.

    Figs. 38A to 38C are views illustrating a state halfway through the continuity inspection process in stages.

    Figs. 39A and 39B are views illustrating a relationship between a direction of the sensor element 10 and an object with which each probe pin of a first conduction measurement part 163A and second conduction measurement part 163B is abutted in the continuity inspection process.


    DESCRIPTION OF THE PREFERRED EMBODIMENTS


    <Configuration of Gas Sensor>



    [0015] Fig. 1 is an external perspective view of a gas sensor (more specifically, its main body) 1 to be manufactured in this preferred embodiment. Fig. 2 is a partial cross-sectional view illustrating a main structure inside the gas sensor 1. In this preferred embodiment, the gas sensor 1 serves to detect a predetermined gas component (such as NOx) with a sensor element 10 (Fig. 2) included therein.

    [0016] The sensor element 10 is an elongated columnar or thin-plate like member including, as a main constituent material, an oxygen-ion conductive solid electrolyte ceramic such as zirconia. The sensor element 10 has a configuration in which a gas inlet, an internal space, and the like are provided on a first tip portion 10a side and various electrodes and wiring patterns are provided on a surface and inside of an element body. In the sensor element 10, a detection gas introduced into the internal space is reduced or decomposed in the internal space, to thereby generate oxygen ions. The gas sensor 1 determines the concentration of the gas component based on a fact that an amount of oxygen ions flowing inside an element is proportional to the concentration of the gas component in the detection gas. A surface facing a front in Fig. 2 is referred to as a main surface P1 of the sensor element 10, and a surface that is perpendicular to the main surface P1 and extends along a longitudinal direction is referred to as a side surface P2. Both the main surface P1 and the side surface P2 extend in the longitudinal direction of the sensor element 10, and a width of the main surface P1 is larger than that of the side surface P2.

    [0017] The outside of the gas sensor 1 is mainly formed of a first cover 2, a fixing bolt 3, and a second cover 4.

    [0018] The first cover 2 is an approximately cylindrical exterior member that protects a portion of the sensor element 10 that comes in direct contact with the detection gas in use, which is specifically the first tip portion 10a including a gas inlet 11 and a closed space 12 (buffer space 12a, first internal space 12b, and second internal space 12c) and the like. The gas inlet 11 is open at the first tip portion 10a, which is the lowermost end of the sensor element 10 in Fig. 2. Each of the buffer space 12a, first internal space 12b, and second internal space 12c is provided inside the sensor element 10. The gas inlet 11, the buffer space 12a, the first internal space 12b, and the second internal space 12c are arranged in this order along the longitudinal direction of the sensor element 10 and are communicated with each other via a diffusion-controlling part.

    [0019] More specifically, the first cover 2 has a double-layer structure of an outside cover 2a and an inside cover (not shown). Each of the outside cover 2a and inside cover has a circular bottom on one side and has a plurality of through holes through which a gas passes in its side surface. Fig. 1 exemplifies through holes HI provided in the outside cover 2a, which are merely an example. A position and number of through holes arranged may be appropriately determined in consideration of how a measurement gas flows into the first cover 2.

    [0020] The fixing bolt 3 is an annular member to be used when the gas sensor 1 is fixed at a measurement position. The fixing bolt 3 includes a threaded bolt portion 3a and a held portion 3b to be held when the bolt portion 3a is screwed. The bolt portion 3a is screwed with a nut provided at a position at which the gas sensor 1 is mounted. For example, the bolt portion 3a is screwed with a nut portion provided in the car exhaust pipe, whereby the gas sensor 1 is fixed to the exhaust pipe such that the first cover 2 side thereof is exposed in the exhaust pipe.

    [0021] The second cover 4 is a cylindrical member that protects other part of the gas sensor 1. A wire harness WH which houses a plurality of lead wires (not shown) for electrically connecting the gas sensor 1 and a drive controller (not shown) extends from an end of the second cover 4.

    [0022] Fig. 2 shows the internal configuration of the gas sensor 1, more specifically, the configuration of the gas sensor 1 except for the first cover 2 and second cover 4 shown in Fig. 1.

    [0023] As shown in Fig. 2, inside the gas sensor 1, a washer 7, three ceramic supporters 8 (8a, 8b, and 8c), and two powder compacts 9 (9a and 9b) are each annularly mounted to the part of the sensor element 10 except for the first tip portion 10a, which includes the gas inlet 11 and the like, and a second tip portion 10b, which includes a connection terminal (electrode terminal) 13 for connection with the lead wires (not shown) housed in the wire harness WH, such that the sensor element 10 is positioned about the axis. The ceramic supporter 8 is a ceramic insulator. Meanwhile, the powder compact 9 is obtained by shaping ceramic powders such as talc. In the following description, the washer 7, the ceramic supporters 8, and the powder compacts 9 are collectively referred to as annularly-mounted members, in some cases, and an assembly in a state that these annularly-mounted members are annularly mounted to the sensor element 10 is referred to as a post-annularly-mounted assembly 31 (refer to Figs. 7A to 7C), in some cases.

    [0024] As shown in Fig. 2, a cylindrical tubular body (inner tube welded product) 30, which is obtained by integrating a housing 5 being a metallic cylindrical member and an inner tube 6 being a metallic cylindrical member, is annularly mounted to the outer peripheries of the washer 7, the ceramic supporters 8 (8a, 8b and 8c), and the power compacts 9 (9a and 9b).

    [0025] The tubular body 30 is a member that the housing 5 and the inner tube 6 are integrated, with one end of the inner tube 6 welded to the housing 5. The housing 5 and the inner tube 6 have substantially the same inside diameter and are connected coaxially. An inside diameter of the tubular body 30 is set to be larger than designed values of maximum outside diameters of the respective annularly-mounted members.

    [0026] The housing 5 is provided with a tapered portion 5c at one end side of the inside thereof. One end side of the post-annularly-mounted assembly 31 is engaged with an inside of the tubular body 30 by the tapered portion 5c. In a position of the inner tube 6 right above the washer 7 and a position of the inner tube 6 at the side of the powder compact 9a, respectively, concave portions 6a and 6b concaved inwardly are formed. Other end side of the post-annularly-mounted assembly 31 is engaged with an inside of the tubular body 30 by the concave portions 6a and 6b.

    [0027] More specifically, the powder compact 9 is compressed after being annularly mounted, and is thereby attached firmly to the sensor element 10. The concave portions 6a and 6b are provided after compressing the powder compact 9. As a result that the firm attachment of the powder compact 9 to the sensor element 10 is achieved, in the tubular body 30, the sensor element 10 is fixed, and a sealing is achieved between the first tip portion 10a side including the gas inlet 11 or the like and the second tip portion 10b including the connection terminal (electrode terminal) 13 for the connection with the lead wires or the like in the sensor element 10. According to the above configuration, airtightness between a measurement gas space including the inspected gas (the measurement gas) which the first tip portion 10a of the sensor element 10 contacts and a reference gas space including a reference gas such as the atmosphere, for example, which the second tip portion 10b contacts is secured. The concave portions 6a and 6b are provided to maintain the compression state of the powder compact 9.

    [0028] In this preferred embodiment, the sealing (the hermetic sealing) for maintaining the airtightness is performed in two stages, that is, a tentative sealing (a first compression) and a main sealing (a second compression). The detail of the hermetic sealing is described hereinafter.

    [0029] In the following description, referred to as the assembled body 40 is a configuration that the tubular body 30 is annularly mounted to the post-annularly-mounted assembly 31 and the concave portions 6a and 6b are provided in the post-annularly-mounted assembly 31 as shown in Fig. 2. In the meanwhile, a workpiece under a state that the formation of the concave portion 6b, which is last performed in sequential assembling processes except for the inspection process, is not completed is referred to as a-semi-assembled body 40α (refer to Figs. 7A to 7C).

    [0030] The assembled body 40 having the aforementioned configuration in Fig. 2 is covered with the first cover 2, fixing bolt 3, and second cover 4, finally to form the gas sensor 1. Specifically, the first cover 2 is connected to a tubular portion 5a at a tip portion of the housing 5. The fixing bolt 3 is annularly mounted to the outer periphery of the housing 5 so as to come in contact with a projection (a flange portion) 5b. Moreover, the second cover 4 is mounted so as to be fitted into an annular groove (not shown) between the fixing bolt 3 and housing 5, which is formed through the above annular mounting.

    [0031] Due to the above-mentioned configuration, in the gas sensor 1, the atmosphere around the first tip portion 10a of the sensor element 10 (atmosphere in the first cover 2) is completely cut off from the outside atmosphere in a case that the gas sensor 1 is mounted at a predetermined position. This allows for accurate measurement of the concentration of the targeted gas component in the detection gas.

    [0032] Figs. 3A to 3C are views for describing details of an electrode terminal 13 of the sensor element 10. As shown in Fig. 3A, the plurality of electrode terminals 13 are provided in the side of the second tip portion 10b in the two main surfaces P1 (P1a and P1b) facing each other in the sensor element 10. More precisely, as shown in Figs. 3B and 3C, each of the two main surfaces P1 is provided with the four electrode terminals 13, that is, the eight electrode terminals 13 in total. Specifically, electrode terminals 13a to 13d are provided in the one main surface P1a, and electrode terminals 13e to 13h are provided in the other main surface P1b. Particularly, the electrode terminals 13f to 13h in the above electrode terminals 13 are also referred to as H+ electrode, H- electrode, and Ht electrode, respectively.

    [0033] Fig. 4 is a view exemplifying a heater structure included in the sensor element 10. The sensor element 10 comprises therein a heater 70 and a pair of heater leads 71 (71a and 71b) connected to both ends of the heater 70. The heater 70 is a resistance heater which generates heat when electrical power is supplied from outside of the sensor element 10 via the heater lead 71 which is an energizing path. The heater 70 can be formed of platinum, for example. The heater 70 is embedded in the side of the first tip portion 1a of the sensor element 10. An insulating layer made of alumina, for example, is formed above and below the heater 70 and heater lead 71 with a view to obtaining an electric insulation with an oxygen-ion conductive solid electrolyte.

    [0034] The heater lead 71a and the heater lead 71b are provided to have substantially the same shape, that is to say, to have the same resistance value as each other. The one heater lead 71a is connected to the H+ electrode (the electrode terminal 13f) inside the sensor element 10, and the other heater lead 71b is connected to the H- electrode (the electrode terminal 13g) inside the sensor element 10.

    [0035] Furthermore, a resistance detection lead 72 is provided in a manner of being lead from a connection part 70a of the heater 70 and the heater lead 71b. A resistance value of the resistance detection lead 72 can be ignored. The resistance detection lead 72 is connected to the Ht electrode (the electrode terminal 13h) inside the sensor element 10.

    [0036] The electrode terminals 13f to 13h are also referred to as the heater electrode terminal hereinafter.

    [0037] In the sensor element 10, electrical current is applied between the H+ electrode and the H- electrode heat with the heater 70, so that the closed space 12 and a surrounding area thereof (and the electrodes provided in each of them) can be heated to and kept at a predetermined temperature. The oxygen-ion conductivity of the solid electrolyte constituting the sensor element 10 is increased by the heat generation of the heater 70.

    [0038] Since the heater lead 71a and the heater lead 71b have the same resistance value as each other and the resistance value of the resistance detection lead 72 can be ignored, a resistance value of the heater 70 (the heater resistance value) RH is calculated by the following equation when a resistance value between the H+ electrode and the Ht electrode is represented by R1 and a resistance value between the H- electrode and the Ht electrode is represented by R2:



    [0039] As described hereinafter, the heater resistance value calculated by the equation (1) is subject to the inspection in a process of manufacturing the gas sensor 1 as the mass-produced product and shipping it according to this preferred embodiment.

    <Outline of Manufacture and Inspection of Assembled Body>



    [0040] Next, there will be described a process of manufacturing the assembled body 40, which is a main subject in this preferred embodiment, in a process of manufacturing the gas sensor 1 and a subsequent inspection process. Fig. 5 is a view schematically illustrating a procedure of manufacturing and inspecting the assembled body 40.

    [0041] The assembled body 40 is manufactured by performing the following processes, in the procedure shown in Fig. 5, on the semi-assembled body 40α assembled by a-semi-assembled body assembling process (a step S1): performing the sealing process for hermetically sealing the inside of the semi-assembled body 40α in two stages, that is, the tentative sealing (the first compression) process (a step S2) and the main sealing (the second compression) process (a step S3), then forming the concave portion 6a in the inner tube 6 by the first swaging process (a step S4), and further forming the concave portion 6b in the inner tube 6 by the second swaging process (a step S5).

    [0042] Then, sequentially performed as the inspection process are a washer inclination inspection process of inspecting an inclination of the washer 7 (a step S5) and a continuity inspection process of inspecting a conductive state by measuring a resistance value of the heater 70 (a heater resistance value) RH (a step S6).

    [0043] When an index value for representing the inclination of the washer 7 obtained in the washer inclination inspection process meets a predetermined acceptability criterion (YES in a step S8) and also when the heater resistance value RH obtained in the continuity inspection process meets a predetermined acceptability criterion (YES in a step S9), the assembled body 40 is determined to be an OK product (an acceptable product) and is then provided to the process in the subsequent stages. In the meanwhile, when the index value obtained in the washer inclination inspection process or the heater resistance value obtained in the continuity inspection process does not meet their acceptability criteria (NO in the step S8 or NO in the step S9), the assembled body is determined to be an NG product (a defective product) and is excluded from a manufacturing object.

    <Outline of Manufacturing Apparatus>



    [0044] Fig. 6 is a block diagram schematically illustrating a structure of a manufacturing apparatus 100 for manufacturing and inspecting the assembled body 40 by the procedure shown in Fig. 5.

    [0045] The manufacturing apparatus 100 includes a control part 101 for controlling the overall operations of the manufacturing apparatus 100, which is constituted by a CPU 101a, a ROM 101b, a RAM 101c and the like, an operating part 102 being an input interface constituted by switches, buttons, a touch panel and the like for providing various types of execution commands to the manufacturing apparatus 100, a display part 103 constituted by a display and measuring instruments for displaying various types of operation menus and operation states of the manufacturing apparatus 100, and a storage part 104 storing an operation program 104p for the manufacturing apparatus 100 and operation condition data and the like which are not illustrated. In the manufacturing apparatus 100, the operation program 104p is executed by the control part 101, so that a series of operations which will be described later are performed through automatic processing.

    [0046] As components for actually manufacturing and inspecting the assembled body, the manufacturing apparatus 100 further includes a transportation part 110, a-semi-assembled body assembling part 120, a tentative sealing processing part 130, a main sealing/swaging processing part 140, a retightening processing part 150, and an inspection processing part 160.

    [0047] The transportation part 110 is a part for transporting the semi-assembled body 40α and the assembled body 40 in the manufacturing apparatus 100. The transportation part 110 includes a transportation pallet 111 on which the semi-assembled body 40α and the assembled body 40 are disposed, a pallet movement mechanism 112 which moves the transportation pallet 111 to each part by a predetermined procedure, and a pallet delivery mechanism 113 for delivering the transportation pallet 111, in which the semi-assembled body 40α and the assembled body 40 are disposed, between each processing part.

    [0048] The semi-assembled body assembling part 120 is a part for assembling the semi-assembled body 40α. The semi-assembled body assembling part 120 includes a first annularly-mounting mechanism 121 for annularly mounting the annularly-mounted members to the sensor element 10 to obtain the post-annularly-mounted assembly 31 and a second annularly-mounting mechanism 122 for annularly mounting the tubular body 30 to the post-annularly-mounted assembly 31 to obtain the semi-assembled body 40α.

    [0049] Further, the semi-assembled body assembling part 120 includes an element standby part 123 and an annularly-mounted member standby part 124 in which the sensor element 10 and the annularly-mounted members (the washer 7, the ceramic supporter 8, and the powder compact 9), which are to be assembled, are disposed respectively, and also includes a tubular body standby part 125.

    [0050] The tentative sealing processing part 130 is a part for performing the tentative sealing (the first compression), which is a processing for compressing the powder compact 9, mainly for purpose of positioning (fixing) the sensor element 10. The tentative sealing processing part 130 includes a pallet mounting stand 131 on which the transportation pallet 111 is disposed, an element positioning pin 132 for positioning the sensor element 10 at the time of the tentative sealing, an element constraining jig 133 for constraining the sensor element 10 during the tentative sealing to be located within a predetermined range, and a tentative sealing jig (a first compression jig) 134 for pressing the washer 7 at the time of the tentative sealing.

    [0051] The tentative sealing processing part 130 further includes a positioning pin elevating mechanism 132m for performing operations for elevating the element positioning pin 132 in a vertical direction, a constraining jig movement mechanism 133m for moving the element constraining jig 133 in a horizontal plane, and a tentative sealing jig elevating mechanism 134m for performing operations for elevating the tentative sealing jig 134 in the vertical direction.

    [0052] The main sealing/swaging processing part 140 is a part for performing the main sealing (the second compression) to secure the airtightness (hermetic sealing) between the measurement gas space and the reference gas space in the gas sensor 1 and forming the concave portion 6a by swaging the inner tube 6 (the first swaging). The main sealing/swaging processing part 140 includes a pallet mounting stand 141 on which the transportation pallet 111 is disposed, a main sealing jig 142 for pressing the washer 7 at the time of the main sealing, and a first swaging jig 143 for swaging the inner tube 6 to form the concave portion 6a.

    [0053] The main sealing/swaging processing part 140 further includes a mounting stand elevating mechanism 141m for performing operations for elevating the pallet mounting stand 141 in the vertical direction and a swaging jig movement mechanism 143m for performing operations for moving the first swaging jig 143 in a horizontal plane.

    [0054] The retightening processing part 150 is a part for forming the concave portion 6b by swaging the inner tube 6 (the second swaging). In this preferred embodiment, referred to as a retightening is the formation, in the inner tube 6, of the concave portion 6b in the second swaging process subsequent to the formation of the concave portion 6a in the first swaging process. The retightening processing part 150 includes a pallet mounting stand 151 on which the transportation pallet 111 is disposed, a retightening assist jig 152 abutting on the washer 7 at the time of the retightening, and a second swaging jig 153 for swaging the inner tube 6 to form the concave portion 6b.

    [0055] The retightening processing part 150 further includes a mounting stand elevating mechanism 151m for performing operations for elevating the pallet mounting stand 151 in the vertical direction and a swaging jig movement mechanism 153m for performing operations for moving the second swaging jig 153 in a horizontal plane.

    [0056] The inspection processing part 160 is a part for performing the washer inclination inspection and the continuity inspection on the assembled body 40 having reached to completion through the retightening performed by the retightening processing part 150. The inspection processing part 160 includes a pallet mounting stand 161 on which the transportation pallet 111 is disposed, a first height measurement part 612A and second height measurement part 162B for measuring height positions in different two parts of the washer 7 at the same time, a first conduction measurement part 163A and second conduction measurement part 163B electrically connected to the electrode terminals 13 provided in the different sides of the two main surfaces P1 (P1a and P1b) of the sensor element 10, and a work guide 164 for holding the sensor element 10 in measuring the conductivity.

    [0057] The inspection processing part 160 further includes a height measurement part drive mechanism 162m for performing operations for elevating the first height measurement part 162A and second height measurement part 162B in the vertical direction and rotating them in the horizontal plane, a conduction measurement part drive mechanism 163m for performing operations for moving the first conduction measurement part 163A and second conduction measurement part 163B in the horizontal plane, a work guide movement mechanism 164m for performing operation for moving the work guide 164 in the horizontal plane, and a resistance measuring instrument 165 for outputting a resistance value of a component at the time when the first conduction measurement part 163A and second conduction measurement part 163B are electrically connected to the electrode terminal 13.

    [0058] In addition, the manufacturing apparatus 100 further includes an inclination determination part 105 and a conduction determination part 106 as functional constituent elements achieved by a control part 101 due to the execution of the operation program 104p.

    [0059] The inclination determination part 105 performs a processing for calculating the index value representing the inclination of the washer 7 based on a measurement result of the height position of the washer 7 in the first height measurement part 162A and second height measurement part 162B and thereby determining whether or not the calculated value falls within a range of a predetermined acceptability criterion (a threshold value).

    [0060] The conduction determination part 106 performs a processing for obtaining resistance values from the resistance measuring instrument 165 for respective parts to which each of the first conduction measurement part 163A and second conduction measurement part 163B are connected, and performing a calculation based on the equation (1) from those resistance values to determine whether or not the obtained values fall within a predetermined acceptability criterion.

    < Assembly of Intermediate Member >



    [0061] A detailed description of the manufacturing and inspecting the assembled body 40 performed by the procedure shown in Fig. 5 is sequentially provided hereinafter.

    [0062] Figs. 7A to 7C are views schematically illustrating a-semi-assembled body assembling process performed in the semi-assembled body assembling part 120 (the step S1 in Fig. 5).

    [0063] In the semi-assembled body assembling process, firstly, the first annularly-mounting mechanism 121 obtains the sensor element 10 from the element standby part 123 and holds the sensor element 10 using a holding means not shown in the drawings. Subsequently, the first annularly-mounting mechanism 121 obtains the washer 7, the ceramic supporter 8a, the powder compact 9a, the ceramic supporter 8b, the powder compact 9b, and the ceramic supporter 8c from the annularly-mounted member standby part 124 in this order and then annularly mounts them to the sensor element 10 from the first tip portion 10a side of the sensor element 10 as indicated by an arrow AR1 in Fig. 7A. Accordingly, the post-annularly-mounted assembly 31 shown in Fig. 7B is obtained. The sensor element 10 and each annularly-mounted member are manufactured in a predetermined place in advance and prepared in the element standby part 123 and the annularly-mounted member standby part 124, respectively, prior to the execution of the semi-assembled body assembling process.

    [0064] More specifically, each annularly-mounted member has a disc shape or cylindrical shape. For annularly mounting as described above, a circular through hole 7h is provided at the axis center position of the washer 7, and through holes 8ah, 9ah, 8bh, 9bh, and 8ch having a rectangular shape corresponding to the cross-sectional shape of the sensor element 10 are provided in the ceramic supporter 8a, powder compact 9a, ceramic supporter 8b, powder compact 9b, and ceramic supporter 8c, respectively. Those through holes are fitted with the sensor element 10, so that the members are each annularly mounted to the sensor element 10. In the above case, the washer 7, ceramic supporters 8, and powder compacts 9 are coaxially arranged.

    [0065] From the point of securing the airtightness, the through holes of the ceramic supporters 8 and the through holes of the powder compacts 9 are configured such that a difference with a design cross-sectional size of the sensor element 10 is 0.25 to 0.35 mm and a dimensional tolerance is 0.1 mm. Meanwhile, the through hole 7h of the washer 7 is provided so as to have a difference with the design cross-sectional size of the sensor element 10 of at least 1 mm or more and 1.3 mm or less. The washer 7, ceramic supporters 8, and powder compacts 9 are configured to have a difference in outside diameter value of approximately 0.35 mm at a maximum.

    [0066] Next, the second annularly-mounting mechanism 122 obtains the tubular body 30 from the tubular body standby part 125 to annularly mount it to the post-annularly-mounted assembly 31 from an inner tube 6 side. Specifically, the tubular body 30 is annularly mounted to the post-annularly-mounted assembly 31 from a side providing the first tip portion 10a of the sensor element 10, as indicated by an arrow AR2 in Fig. 7B. Accordingly, the semi-assembled body 40α shown in Fig. 7C is obtained. At this time, since the semi-assembled body 40α is not sealed yet, the sensor element 10 is not completely fixed. Accordingly, the sensor element 10 can be displaced in the longitudinal direction due to an action of an external force, for example. In other words, in the semi-assembled body 40α which is not yet sealed, the sensor element 10 is not positioned. The sensor element 10 is positioned in the tentative sealing process performed in a next step.

    <Transportation and Delivery by Transportation Part>



    [0067] The semi-assembled body 40α assembled in the semi-assembled body assembling part 120 is then transported by the transportation part 110 and is delivered between the transportation part 110 and respective parts performing processing in subsequent stages.

    [0068] Fig. 8 is a planar view schematically illustrating a transportation of the semi-assembled body 40α and the assembled body 40 in the transportation part 110 and the delivery of the semi-assembled body 40α and the assembled body 40 between the transportation part 110 and respective parts.

    [0069] In outline, the transportation part 110 is configured such that the semi-assembled body 40α and the assembled body 40 are transported in a state of being disposed on the transportation pallet 111, and the delivery of the semi-assembled body 40α or the assembled body 40 between the transportation part 110 and respective parts is performed together with the transportation pallet 111 on which the semi-assembled body 40α or the assembled body 40 is disposed.

    [0070] A fitting part 111a is provided in an upper part of the transportation pallet 111, and the semi-assembled body 40α or the assembled body 40 is fitted with the fitting part 111a, so that the semi-assembled body 40α or the assembled body 40 is disposed on and fixed to the transportation pallet 111. More specifically, a lower portion of the tubular body 30 of the semi-assembled body 40α or the assembled body 40 in such a posture that its side provided with the washer 7 is directed upward is fitted into the fitting part 111a, so that the semi-assembled body 40α or the assembled body 40 is disposed on and fixed to the transportation pallet 111 (refer to Fig. 10, for example.) In this preferred embodiment, the lower portion of the tubular body 30 indicates the projection 5b and a part located below the projection 5b in the housing 5 in Fig. 2. In other words, the semi-assembled body 40α and the assembled body 40 are transported by the transportation pallet 111 in such a posture that the longitudinal direction of the sensor element 10 extends in the vertical direction and its side provided with the second tip portion 10b is directed upward. Such a posture of the semi-assembled body 40α and the assembled body 40 is also referred to as an assembly posture.

    [0071] The semi-assembled body 40α and the assembled body 40 are preferably positioned so that a rotational deviation is prevented in the horizontal plane at the time of the disposition and fixing. This may be achieved by causing an outer periphery shape of the housing 5 to have anisotropy and also causing the fitting part 111a to have a shape corresponding to the outer periphery shape, or the holding means (not shown) included in the transportation pallet 111 may hold a horizontal posture of the semi-assembled body 40α and the assembled body 40.

    [0072] In the transportation part 110, determined in advance are a first delivery position Pos1 for receiving the assembled semi-assembled body 40α from the semi-assembled body assembling part 120 and second delivery position Pos2 to fifth delivery position Pos5 for delivering the semi-assembled body 40α or the assembled body 40 between the transportation part 110 and the tentative sealing processing part 130, the main sealing/swaging processing part 140, the retightening processing part 150, and the inspection procession part 160, respectively.

    [0073] The tentative sealing processing part 130, the main sealing/swaging processing part 140, the retightening processing part 150, and the inspection processing part 160 are provided with the pallet mounting stands 131, 141, 151, and 161 which the transportation pallet 111 is disposed on and fixed to, respectively. The pallet mounting stands 131, 141, 151, and 161 include pallet fitting parts 131a, 141a, 151a, and 161a, respectively, and the transportation pallet 111 is fitted into these pallet fitting parts 131a, 141a, 151a, and 161a in each processing part to achieve a state where the transportation pallet 111 is disposed on and fixed to the pallet mounting stands 131, 141, 151, and 161.

    [0074] The pallet movement mechanism 112 (not shown in Fig. 8) firstly places the transportation pallet 111 in the first delivery position Pos1 at a timing of assembling the semi-assembled body 40α in the semi-assembled body assembling part 120. The obtained semi-assembled body 40α is delivered to the transportation pallet 111 disposed in the first delivery position Pos1, as indicated by an arrow AR3, by the pallet delivery mechanism 113 not shown in Fig. 8.

    [0075] Subsequently, alternately performed are the transport of the transportation pallet 111 to the second delivery position Pos2 to fifth delivery position Pos5 performed by the pallet movement mechanism 112 indicated by arrows AR4 to AR7 and the delivery of the transportation pallet 111 between each delivery position and pallet mounting stand performed by the pallet delivery mechanism 113 indicated by arrows AR8 to AR11 in Fig. 8.

    [0076] The transportation pallet 111 is returned from the inspection processing part 160 to the fifth delivery position Pos5 after the completion of the inspection processing in the inspection processing part 160. When the assembled body 40 held by the transportation pallet 111 is an acceptable product in the inspection performed in the inspection processing part 160, the assembled body 40 is delivered to an assembled body standby part 170. In the meanwhile, when the assembled body 40 is a rejected product in the inspection, the assembled body 40 is discarded. In any case, the transportation pallet 111 which has become empty is returned to the first delivery position Pos1 and is then used in the subsequent processing again.

    [0077] Alternatively, it is also applicable the transportation pallet 111 which has transported the semi-assembled body 40α or the assembled body 40 from a previous delivery position to a delivery position corresponding to a certain processing part is different from the transportation pallet 111 which transports the semi-assembled body 40α or the assembled body 40 to a next delivery position after the completion of the processing in the processing part.

    <Tentative Sealing>



    [0078] The semi-assembled body 40α which has been assembled in the semi-assembled body assembling part 120 is provided to the tentative sealing (the first compression) process (the step S2 in Fig. 5) performed in the tentative sealing processing part 130. The tentative sealing process is a process performed mainly for purpose of tentatively fixing the sensor element 10 in a position where the sensor element 10 abuts to the element positioning pin 132. The term "tentative" is used herein by reason that a slight displacement of the sensor element 10 occurs at the time of the main sealing (the second compression) which is to be performed subsequently.

    [0079] Fig. 9 is a view illustrating a more specific procedure of the tentative sealing process. Fig. 10 is a side view (a partial cross-sectional view) schematically illustrating a structure of the tentative sealing processing part 130. Figs. 11A and 11B are views for describing the element constraining jig 133. Furthermore, Figs. 12A to 13B are views illustrating a state halfway through the tentative sealing process in stages.

    [0080] The tentative sealing processing part 130 mainly includes the pallet mounting stand 131, the element positioning ping 132, the pair of element constraining jigs 133 (133a and 133b), and the tentative sealing jig 134.

    [0081] Fig. 10 illustrates a state where the transportation pallet 111 holding (placing and fixing) the semi-assembled body 40α is disposed on the pallet mounting stand 131. Fig. 10 illustrates a state where the semi-assembled body 40α is disposed and fixed in the assembly posture, in which a thickness direction of the sensor element 10 coincides a horizontal direction of Fig. 10, in other words, the main surface P1 is perpendicular to the horizontal direction of Fig. 10, and one of the side surfaces P2 is directed to a near side of Fig. 10. The state where the transportation pallet 111 to which the semi-assembled body 40α is placed and fixed is disposed on and fixed to the pallet mounting stand 131 is also referred to simply as a state where the semi-assembled body 40α is fixed to the pallet mounting stand 131. In Fig. 10 and subsequent drawings, a coordinate in which a vertical upper side is defined as a forward direction of a z axis is illustrated, appropriately.

    [0082] As shown in Fig. 10, a hole part 111b is provided in a lower side of the fitting part 111a in the transportation pallet 111 to prevent the sensor element 10 protruding in a lower side of the semi-assembled body 40α from interfering with the transportation pallet 111. In addition, the pallet mounting stand 131 also includes a hole part 131b in a lower side of the pallet fitting part 131a. The hole part 131b is provided so as to come to be coaxial with the hole part 111b of the transportation pallet 111 at the time when the transportation pallet 111 is disposed on the pallet fitting part 131a.

    [0083] As described above, since the sensor element 10 is not positioned, it can displaced up and down in the hole part 111b and further in the hole part 131b as indicated by an arrow AR12.

    [0084] The hole parts 111b and 131b are also used as a space of elevating the element positioning pin 132. Although not shown in the drawings, the hole part 131b has a configuration that the sensor element 10 does not protrude from the transportation pallet 111.

    [0085] The element positioning pin 132 has a configuration that it can be elevated in the vertical direction as indicated by an arrow AR13 and can enter the hole parts 111b and 131b in the positioning pin elevating mechanism 132m not shown in Fig. 10. Although the detail will be described hereinafter, the element positioning pin 132 raised by the positioning pin elevating mechanism 132m comes to abut to the sensor element 10 in the hole part 111b at the time of the tentative sealing, and the sensor element 10 is thereby positioned.

    [0086] The pair of element constraining jigs 133 (133a and 133b) are provided in a position which is located in an upper side of the semi-assembled body 40α in the state where the semi-assembled body 40α is fixed to the pallet mounting stand 131. As shown in Fig. 11A, the element constraining jigs 133a and 133b have shapes line-symmetrical to each other in planar view but are provided at a predetermined distance Δh from each other in the vertical direction, which is also an extending direction of the sensor element 10. That is to say, they are provided in different height positions.

    [0087] More specifically, the element constraining jigs 133a and 133b have groove portions 133c and 133d at their end portions, respectively, and the element constraining jigs 133a and 133b are disposed so that these groove portions 133c and 133d face each other in planar view.

    [0088] The element constraining jigs 133a and 133b can move close to and away from each other in the horizontal plane as indicated by arrows AR14 and AR15 in Fig. 11A by the constraining jig movement mechanism 133m not shown in Figs. 11A and 11B. More specifically, the element constraining jigs 133a and 133b are brought close to each other by the constraining jig movement mechanism 133m, with the sensor element 10 existing therebetween as shown in Fig. 11A, and then they forms the constraining region 133e having a rectangular shape in planar view with an intersection of each other as shown in Fig. 11B, so that the sensor element 10 (more specifically, the second tip portion 10b side) can be constrained within a range of the constraining region 133e.

    [0089] The element constraining jig 133a and the element constraining jig 133b might be provided in the same height position. However, when their height position are differently provided as this preferred embodiment, a collision between them does not need to be considered at a time of bringing the element constraining jig 133a and the element constraining jig 133b close to each other to form the constraining region 133e. Therefore, this preferred embodiment is advantageous in view of a degree of freedom in processing the element constraining jig 133a and the element constraining jig 133b and size accuracy of the constraining region 133e.

    [0090] The tentative sealing jig 134 is provided so as to be elevated in the vertical direction by the tentative sealing jig elevating mechanism 134m not shown in Fig. 10 in a position which is located in a vertical upper side of the semi-assembled body 40α (more specifically, the sensor element 10) in the state where the semi-assembled body 40α is fixed to the pallet mounting stand 131. The tentative sealing jig 134 includes a pair of abutting parts 134a in its lower side in the vertical direction. The pair of abutting parts 134a extend toward a vertically lower side, and abut to two portions, opposing each other of an upper surface of the washer 7, which constitutes the semi-assembled body 40α, from the upper side at the time of the tentative sealing. The tentative sealing jig 134 is disposed coaxially with the semi-assembled body 40α fixed to the pallet mounting stand 131.

    [0091] A cavity part 134b is located between the pair of abutting parts 134a. The cavity part 134b is a part in which the sensor element 10 and the element constraining jig 133 are housed at the time of the tentative sealing. The cavity part 134b is provided to prevent interference between the tentative sealing jig 134 and the sensor element 10 and element constraining jig 133 when the tentative sealing jig 134 descends for the tentative sealing.

    [0092] In performing the tentative sealing process in the tentative processing part 130, firstly, the transportation pallet 111, which has been delivered from the semi-assembled body assembling part 120 in the first delivery position Pos1 and holds (places and fixes) the semi-assembled body 40α, is disposed in the second delivery position Pos2 by the pallet movement mechanism 112, and then, the transportation pallet 111 is disposed on and fixed to the pallet mounting stand 131 in the tentative sealing processing part 130 together with the semi-assembled body 40α, by the pallet delivery mechanism 113, as shown in Fig. 10 (a step S21).

    [0093] Upon disposition and fixing, the positioning pin elevating mechanism 132m raises the element positioning pin 132 to the vertical upper side in the hole part 131b and the hole part 111b as indicated by an arrow AR16 in Fig. 12A to place the element positioning pin 132 in a predetermined position (a step S22).

    [0094] More specifically, when a target value of a distance between a lowermost end of the ceramic supporter 8c and a lowermost end of the sensor element 10 (the end in the first tip portion 10a side) under a state that the assembled body 40 is hermetically sealed finally (referred to as a protruding length) is defined as t0, the element positioning pin 132 is disposed so that the protruding length is set to t1 which is shorter than t0. Accordingly, the sensor element 10 is pushed up as indicated by an arrow AR17, so that the second tip portion 10b protrudes from the tubular body 30. The position where the sensor element 10 is located at this time is defined as a first position.

    [0095] Such a placement of the sensor element 10 in the first position where the protruding length is t1 due to pushing up the lowermost end of the sensor element 10 with the element positioning pin 132 is performed in consideration of the shifting that the sensor element 10 descends from the first position in the process in the subsequent stages, and the protruding length gets closer to t0. A difference between the protruding lengths t0 and t1 is experimentally determined in advance.

    [0096] After the element positioning pin 132 is disposed in the first tip portion 10a side of the sensor element 10, an existing range of the sensor element 10 in the horizontal plane is subsequently limited by the element constraining jig 133 (a step S23).

    [0097] Specifically, the element constraining jig 133a and the element constraining jig 133b are moved in a direction close to each other as indicated by arrows AR18 and AR19 in Fig. 12A by the constraining jig movement mechanism 133m, thereby being disposed to form the constraining region 133e shown in Figs. 11A and 11B. Fig. 12B shows a state where the element constraining jig 133a and the element constraining jig 133b are disposed as described above. Accordingly, in the subsequent processes, the existing range of the sensor element 10 in the horizontal plane (more generally, in a plane perpendicular to the extending direction of the sensor element 10 and the tubular body 30) is limited within the range of the constraining region 133e.

    [0098] After the constraining region 133e is formed, the tentative sealing (the first compression) is subsequently performed by the tentative sealing jig 134 (a step S24).

    [0099] The tentative sealing is achieved by lowering the tentative sealing jig 134 from the upper side of the semi-assembled body 40α toward the vertically lower side as indicated by an arrow AR20 in Fig. 12B, with the tentative sealing jig elevating mechanism 134m not shown in Fig. 12B.

    [0100] When the tentative sealing jig elevating mechanism 134m lowers the tentative sealing jig 134, the abutting part 134a of the tentative sealing jig 134 abuts to the washer 7 in due course. At this time, the sensor element 10 and the element constraining jig 133 (133a and 133b) are housed in the cavity part 134b.

    [0101] The tentative sealing jig elevating mechanism 134m continues to lower the tentative sealing jig 134 as indicated by an AR21 in Fig. 13A after the abutting part 134a abuts to the washer 7. The abutting part 134a of the tentative sealing jig 134 thereby presses the washer 7 to apply a vertically downward force (load) F1 (a first force) to the washer 7. Herein, the force F1 is applied within a range that the sensor element 10 can be fixed but a crack (or a break) does not occur in the sensor element 10. The actual value of the force F1 may be set in view of an area of the abutting part 134a which abuts to the washer 7.

    [0102] When the force F1 acts on the washer 7 from the abutting part 134a, the washer 7 is slightly pushed vertically downward, and the force F1 also acting on the powder compacts 9a and 9b via the ceramic supporters 8a and 8b acts as a compression force. The powder compacts 9a and 9b are thereby compressed. In accordance with the compression, a gap between the powder compacts 9a and 9b and the sensor element 10 disappears, and the powder compacts 9a and 9b are attached firmly to the sensor element 10. Then, the sensor element 10 which has been displaceable in the vertical direction is fixed by the powder compacts 9a and 9b. Since the sensor element 10, which is positioned by the element positioning pin 132, is kept in the first position, the sensor element 10 is fixed, as a result, to the first position at which the protruding length in the lowermost end of the sensor element 10 is t1.

    [0103] After the tentative sealing is finished, as indicated by arrows AR22 and AR25 in Fig. 13B, the tentative sealing jig 134, the element positioning pin 132, the element constraining jig 133a, and the element constraining jig 133b are sequentially taken off (a step S25). Then, the transportation pallet 111 holding the semi-assembled body 40α, on which the tentative sealing has been performed, is delivered from the pallet mounting stand 131 to the pallet movement mechanism 112 by the pallet deliver mechanism 113 (a step S26). That is to say, the transportation pallet 111 is disposed in the second deliver position Pos2 again. The tentative sealing process is thereby finished.

    [0104] In the above tentative sealing process, the tentative sealing is performed with forming the constraining region 133e, as described above. Figs. 14A to 14C are cross-sectional views of a main part of the assembled body 40 for describing an effect of formation of the constraining region 133e at the time of the tentative sealing.

    [0105] The assembled body 40 is obtained through the main sealing process, the first swaging process, and the second swaging process after the tentative sealing process, and it is ideal that in the assembled body 40, the sensor element 10 is fixed to have a gap G between the sensor element 10 and the ceramic supporter 8a as shown in Fig. 14A. If the sensor element 10 is fixed in the assembled body 40 with being excessively inclined at the second tip portion 10b side or being totally displaced, the sensor element 10 may come in contact with the ceramic supporter 8a as indicated by a broken line part E shown in Fig. 14B, for example, and a stress may act on the sensor element 10 from the ceramic supporter 8a. Such a stress acting on the sensor element 10 may cause a defect such as a crack CR, a chip, or a breakage of the sensor element 10 originated in the crack CR, as shown in Fig. 14C. Such an inclination or displacement of the sensor element 10 is also referred to as "the misalignment" hereinafter. The defect due to the breakage of the sensor element 10 is also referred to as "the breakage failure of the element".

    [0106] Such a misalignment of the sensor element 10 is most likely to occur in the tentative sealing process which is performed under a circumstance that the sensor element 10 is not completely fixed although it is annularly mounted with each annularly-mounted member and is positioned by the element positioning pin 132.

    [0107] In this preferred embodiment, in view of the above points, the tentative sealing is performed under the circumstance that the constraining region 133e is formed by the pair of element constraining jigs 133, so that the misalignment, which may occur in the sensor element 10 at the time of the tentative sealing, is suppressed to such an extent that the sensor element 10 only comes in direct contact with the element constraining jig 133a or the element constraining jig 133b. A plane size of the constraining region 133e which is actually formed, the distance Δh between the element constraining jigs 133a and 133b, or the like, are different according to the size of the sensor element 10, the target value t0 of the protruding length of the sensor element 10, or the like. However, as long as at least a clearance between the pair of element constraining jigs 133 and the sensor element 10 at the time when the constraining region 133e is formed is equal to or smaller than a maximum possible design value of the gap between the sensor element 10 and the ceramic supporter 8a, which is closest to the constraining region 133e in the three ceramic supports 8 and, the sensor element 10 does not come in contact with the ceramic supporter 8a even if the sensor element 10 is inclined in the assembled body 40 to some degree.

    [0108] Fig. 15 is a view describing how to evaluate the misalignment of the sensor element 10 in the assembled body 40. In this preferred embodiment, the degree of the misalignment of the sensor element 10 in the assembled body 40 is evaluated with a distance ΔC between a position C0 of a central axis of the inner tube 6 in the cross section perpendicular to the longitudinal direction of the assembled body 40 and a position C1 of a central axis of the sensor element 10. Therefore, the distance ΔC is also referred to as "the misalignment amount".

    [0109] Fig. 16 is a view exemplifying an effect of the element constraining jig 133. Specifically, Fig. 16 is a histogram indicating a distribution of the misalignment amount in case of preparing the thirty assembled bodies 40 using the element constraining jig 133 at the time of the tentative sealing ("constrained" in Fig. 16) and the thirty assembled bodies 40 without using the element constraining jig ("not constrained" in Fig. 16) and evaluating the misalignment amount for all the assembled bodies 40.

    [0110] It is confirmed from Fig. 16 that the alignment amount tends to be smaller in the case of "constrained" compared with the case of "not constrained". This means that using the element constraining jig 133 at the time of the tentative sealing has the effect of suppressing the misalignment.

    <Main Sealing and First Swaging>



    [0111] The semi-assembled body 40α on which the tentative sealing is performed in the tentative sealing processing part 130 is provided to the main sealing (the second compression) process (the step S3 in Fig. 5) and the subsequent first swaging process (the step S4 in Fig. 5) performed in the main sealing/swaging processing part 140. The main sealing process is a process performed mainly for purpose of securing the airtightness between the measurement gas space and the reference gas space. The first swaging process is a process performed for completely constraining the annularly-mounted member in the tubular body 30 of the main-sealed semi-assembled body 40α.

    [0112] Fig. 17 is a view illustrating a more specific procedure of the main sealing (the second compression) process and the first swaging process. The main sealing process and the first swaging process are sequentially performed in the main sealing/swaging processing part 140. Fig. 18 is a side view (a partial cross-sectional view) schematically illustrating a structure of the main sealing/swaging processing part 140. Figs. 19 and 20 are views illustrating a state halfway through the main sealing process in stages. Figs. 21A and 21B are views for describing an operation of the swaging jig movement mechanism 143m at the time of the first swaging. Furthermore, Figs. 22, 23, and 24 are views illustrating a state halfway through the first swaging process in stages.

    [0113] The main sealing/swaging processing part 140 mainly includes the pallet mounting stand 141, the main sealing jig 142, and the first swaging jig 143.

    [0114] Fig. 18 illustrates a state where the transportation pallet 111 holding (placing and fixing) the semi-assembled body 40α is disposed on the pallet mounting stand 141. Fig. 18 also illustrates, in a manner similar to Fig. 10, a state where the semi-assembled body 40α is disposed and fixed in the assembly posture, in which the thickness direction of the sensor element 10 coincides the horizontal direction when seeing Fig. 18. The state where the transportation pallet 111 to which the semi-assembled body 40α is placed and fixed is disposed on and fixed to the pallet mounting stand 141 is also referred to simply as a state where the semi-assembled body 40α is fixed to the pallet mounting stand 141.

    [0115] Although the pallet mounting stand 141 has a configuration similar to the pallet mounting stand 131 included in the tentative sealing processing part 130, it differs from the pallet mounting stand 131 in that it can be elevated in the vertical direction by the mounting stand elevating mechanism 141m. The mounting stand elevating mechanism 141m is made up of a servo cylinder.

    [0116] The main sealing/swaging processing part 140 includes a support shaft 140s extending in the vertical direction in an upper position of the pallet mounting stand 141, and the main sealing jig 142 is attached to the support shaft 140s. More specifically, the support shaft 140s has a cavity part 140a which opens downward in its lower end, and the main sealing jig 142 is fixedly provided to the support shaft 140s so as to protrude to the cavity part 140a.

    [0117] The main sealing jig 142 includes a substantially annular abutting part 142a, which abuts to the washer 7 which constitutes the semi-assembled body 40α from its upper side, in a lowermost end thereof in the vertical direction, and, a cavity part 142b which opens toward a vertically lower side. The main sealing jig 142 is disposed coaxially with the semi-assembled body 40α fixed to the pallet mounting stand 141.

    [0118] A through hole 140b is provided in the support shaft 140s so as to extend laterally from the cavity part 140a, and the first swaging jig 143 is provided in the through hole 140b so as to be movable along an extending direction of the through hole 140b.

    [0119] Fig. 18 illustrates the two through holes 140b in the horizontal direction of Fig. 18 and also illustrates the first swaging jig 143 disposed in each through hole 140b, however, the through hole 140b is actually provided in each of four sides of the cavity part 140a, that is to say, in four parts in total as described hereinafter. The first swaging jig 143 is also provided in each of the through hole 140b in the four parts (refer to Figs. 21A and 21B).

    [0120] The first swaging jig 143 includes a claw part 143a in one end directed to the cavity part 140a side and a guided part 143b which is guided by the swaging jig movement mechanism 143m in the other end side.

    [0121] The swaging jig movement mechanism 143m includes a servo cylinder 144 provided to be extensible in the vertical direction and a guide member 145 provided in a lower end of the servo cylinder 144. The servo cylinder 144 and the guide member 145 are provided in four parts in total to correspond to each first swaging jig 143. The guide member 145 includes a guide surface 146 for guiding the guided part 143b of the first swaging jig 143. The guide surface 146 is inclined at an angle of a predetermined degrees with respect to the vertical direction and is perpendicular to a vertical plane including the extending direction of the through hole 140b in which the corresponding first swaging jig 143 exists. The guided part 143b of the first swaging jig 143 is provided to be in contact with the guide surface 146 and to be movable along the inclination direction of the guide surface 146.

    [0122] In performing the main sealing process and the subsequent first swaging process in the main sealing/swaging processing part 140, the transportation pallet 111, which has been delivered from the tentative sealing processing part 130 in the second delivery position Pos2 and holds (places and fixes) the semi-assembled body 40α, is disposed in the third delivery position Pos3 by the pallet movement mechanism 112, and then, the transportation pallet 111 is disposed on and fixed to the pallet mounting stand 141 in the main sealing/swaging processing part 140 together with the semi-assembled body 40α, by the pallet delivery mechanism 113, as shown in Fig. 18 (a step S31).

    [0123] After the transportation pallet 111 is disposed and fixed as described above, with the operation of the mounting stand elevating mechanism 141m, the pallet mounting stand 141 to which the semi-assembled body 40α is fixed is raised as indicated by an arrow AR26 in Fig. 18. When the pallet mounting stand 141 continues to be raised, the washer 7 of the semi-assembled body 40α comes to abut to the abutting part 142a of the main sealing jig 142 in due course, as shown in Figs. 14A to 14C (a step S32). At this time, the sensor element 10 is housed in the cavity part 142b.

    [0124] The mounting stand elevating mechanism 141m continues to raise the pallet mounting stand 141 as indicated by an arrow AR27 in Fig. 19 after the abutting part 142a abuts to the washer 7. The abutting part 142a of the main sealing jig 142 thereby presses the washer 7 to apply a vertically downward force (load) F2 (a second force) to the washer 7 as shown in Fig. 20. At this time, the force F2 is set to be large compared with the force F1 applied at the time of the tentative sealing. The actual value of the force F2 may be set in view of an area of the abutting part 142a which abuts to the washer 7.

    [0125] When the force F2 acts on the washer 7 from the abutting part 142a, the washer 7 is further pushed vertically downward, and the force F2 also acting on the powder compacts 9a and 9b via the ceramic supporters 8a and 8b acts as a compression force. The powder compacts 9a and 9b are thereby further compressed. As a result, the hermetic sealing is achieved between the measurement gas space and the reference gas space. Accordingly, the main sealing (the second compression) is achieved (a step S33).

    [0126] An upper limit value of the pressure acting on the washer 7 at the time of applying the force F2 may be appropriately set in view of a material strength of the main sealing jig 142, the washer 7, or the ceramic supporter 8, for example.

    [0127] Since the main sealing is performed without causing the element positioning pin 132 to abut to the sensor element 10, the sensor element 10 which is once fixed in the first position by the powder compacts 9a and 9b at the time of the tentative sealing further slightly descends at the time of the main sealing. When the protruding length of the sensor element 10 after the main sealing is defined as t2, t2 has a value closer to t0 rather than t1. The position of the sensor element 10 after the main sealing is defined as a second position. Although it is ideal to satisfy t2 = t0, it can be determined that the sensor element 10 is successfully fixed as long as a value Δt = t2 - t0 falls within a predetermined error range allowed in light of characteristics desired for the gas sensor 1, that is to say, as long as the second position is within a range which is determined in advance for the position of the sensor element 10 in the assembled body 40 (the semi-assembled body 40α in this stage). Accordingly, in this preferred embodiment, the position of the element positioning pin 132 is determined so that the second position satisfies such a condition of the range. The allowable error range of Δt may be appropriately determined in advance.

    [0128] In this preferred embodiment, the reason why the hermetic sealing is performed in two-stages is to prevent the occurrence of the chip (the break) in the sensor element 10 caused by applying a strong force at the time of the sealing. That is to say, although the lowermost end of the sensor element 10 abuts to the element positioning pin 132 at the time of the tentative sealing, the force F1 added to compress the powder compact 9 at the time of the tentative sealing is sufficiently smaller than the force F2 added at the time of the main sealing for securing the airtightness. Since the lowermost end of the sensor element 10 does not abut to the element positioning pin 132 at the time of the main sealing, the strong force does not act on the first tip portion 10a of the sensor element 10. Accordingly, in the case of the two-stage sealing performed in this preferred embodiment, the chip (the break) does not occur in the sensor element 10. In this preferred embodiment, accordingly, the occurrence of the defect caused by the chip (the break) in the sensor element 10 can be reliably prevented at the time of the hermetic sealing of the assembled body 40.

    [0129] Furthermore, the sensor element 10 can be appropriately fixed in the desired position by appropriately determining a position of the element positioning pin 132 at the time of the tentative sealing, the force F1 acting on the powder compact 9 at the time of the tentative sealing, and the force F2 acting on the powder compact 9 at the time of the main sealing.

    [0130] Specifically, in some cases, there is a strong correlation (a linear relationship, for example) between the protruding length t1 after the tentative sealing and the protruding length t2 after the main sealing. In the case that such a correlation is specified in advance, the protruding length t2 of the sensor element 10 after the main sealing can be set within the allowable error range of Δt based on the correlation, by appropriately determining the position of the lowermost end of the sensor element 10 at the time of the tentative sealing (that is to say, the upper end position of the element positioning pin 132) and the values of the forces F1 and F2 acted on by the tentative sealing jig 134 and the main sealing jig 142 at the time of the tentative sealing and the main sealing. That is to say, the sensor element 10 can be fixed in the desired position in light of the characteristics of the gas sensor 1.

    [0131] After the main sealing is performed according to the above described manner, the first swaging process is subsequently performed while maintaining the state where the main sealing jig 142 is abutting to the washer 7. In outline, the first swaging is achieved by, as indicated by an arrow AR28 in Fig. 20, extending the servo cylinder 144 vertically downward in the swaging jig movement mechanism 143m.

    [0132] Figs. 21A and 21B are views for describing detailed configuration and operation of the first swaging jig 143 and the swaging jig movement mechanism 143m which is a movement mechanism of the first swaging jig 143. As illustrated by a schematic top view in a lower side of Fig. 21A, in the main sealing/swaging processing part 140, the four first swaging jigs 143 are provided toward four directions in the horizontal plane, respectively. Each first swaging jig 143 is configured to be movable along the through hole 140b extending in the horizontal direction. Under the state that the washer 7 of the semi-assembled body 40α abuts to the main sealing jig 142, these four first swaging jigs 143 are symmetrically located with respect to the inner tube 6 of the semi-assembled body 40α.

    [0133] In the swaging jig movement mechanism 143m, when the servo cylinder 144 corresponding to each first swaging jig 143 is extended vertically downward as indicated by the arrow AR29, the guide member 145 associated with the servo cylinder 144 descends vertically downward. The guide member 145 then applies a vertically downward force to the guided part 143b of the first swaging jig 143 which is in contact with the guide surface 146 of the guide member 145 and is about to press down the guided part 143b. However, as described above, although the guided part 143b is provided to be movable along the inclination direction of the guide surface 146 which is the inclination surface, the first swaging jig 143 as a whole is configured to be movable along the through hole 140b extending in the horizontal direction. That is to say, the moving direction of the first swaging jig 143 is limited within the horizontal plane. Accordingly, as a result, when the guide member 145 descends due to the extension of the servo cylinder 144, the guided part 143b is relatively raised along the guide surface 146 as indicated by an arrow AR30 in Fig. 21A and at the same time, the first swaging jig 143 moves in the through hole 140b toward the inner tube 6 as indicated by an arrow AR31. When the servo cylinder 144 extends by a predetermined distance ΔZ, the claw part 143a of the first swaging jig 143 comes to abut to an outer periphery surface of the inner tube 6.

    [0134] As shown in Figs. 21A and 21B, an end of the claw part 143a included in each first swaging jig 143 has a curved surface in accordance with a shape of the inner tube 6, so that when the claw part 143a abuts to the inner tube 6, its whole curved surface is abutted to the inner tube 6.

    [0135] As shown in Fig. 21B, a position (a height position) in which each claw part 143a abuts to the outer periphery surface of the inner tube 6 is set to a position right above the washer 7. In the manufacturing apparatus 100 according to this preferred embodiment, determined are the second force F2 added to the washer 7 in the main sealing process and the configuration and operation manner of the swaging jig movement mechanism 143m including the shape of the claw part 143a of the first swaging jig 143 or the like, in order to satisfy the positional relationship.

    [0136] As shown in Fig. 22, when the servo cylinder 144 is continuously extended vertically downward as indicated by an arrow AR32 after the claw part 143a of the first swaging jig 143 comes to abut to the outer periphery surface of the inner tube 6, the inner tube 6 is pressed by the claw part 143a. The inner tube 6 is thereby swaged from the outer periphery side, and as shown in Fig. 23, the concave portion 6a is formed in the outer periphery surface of the inner tube 6 located right above the washer 7 (a step S41). The annularly-mounted member in the tubular body 30 is thereby completely constrained. Since the first swaging jigs 143 are located only in the four sides as shown in Figs. 21A and 21B, the concave portion 6a is not necessarily formed around the inner tube 6 in the whole circumferential direction uniformly and continuously.

    [0137] After the concave portion 6a is formed, the servo cylinder 144 is shortened vertically upward as indicated by an arrow AR33 in Fig. 23. Accordingly, the first swaging jig 143 which has pressed the inner tube 6 is also taken off as indicated by an arrow AR34 (a step S42).

    [0138] After the first swaging jig 143 is taken off, the mounting stand elevating mechanism 141m operates again to lower the pallet mounting stand 141 to a default position as indicated by an arrow AR35 (a step S43). Fig. 24 illustrates a state after the pallet mounting stand 141 descends to the default position.

    [0139] Then, the transportation pallet 111 holding the semi-assembled body 40α, on which the first swaging has been performed, is delivered from the pallet mounting stand 141 to the pallet movement mechanism 112 by the pallet deliver mechanism 113 (a step S44). That is to say, the transportation pallet 111 is disposed in the second deliver position Pos3 again. The main sealing process and the subsequent first swaging process are thereby finished.

    <Second Swaging (Retightening)>



    [0140] The semi-assembled body 40α on which the main sealing and the first swaging are performed in the main sealing/swaging processing part 140 is provided to the second swaging (retightening) process performed in the retightening processing part 150 (the step S5 in Fig. 5). The second swaging process is a process for further securing the constraining of the annularly-mounted member in the tubular body 30.

    [0141] Fig. 25 is a view illustrating a more specific procedure of the second swaging process. Fig. 26 is a side view (a partial cross-sectional view) schematically illustrating a structure of the retightening processing part 150. Furthermore, Figs. 27, 28, 29, and 30 are views illustrating a state halfway through the second swaging process in stages.

    [0142] The retightening processing part 150 mainly includes the pallet mounting stand 151, the retightening assist jig 152, and the second swaging jig 153.

    [0143] Fig. 26 illustrates a state where the transportation pallet 111 holding (placing and fixing) the semi-assembled body 40α is disposed on the pallet mounting stand 151. Fig. 26 also illustrates, in a manner similar to Fig. 10, a state where the semi-assembled body 40α is disposed and fixed in the assembly posture, in which a thickness direction of the sensor element 10 coincides to the horizontal direction when seeing Fig. 26. The state where the transportation pallet 111 to which the semi-assembled body 40α is placed and fixed is disposed on and fixed to the pallet mounting stand 151 is also referred to simply as a state where the semi-assembled body 40α is fixed to the pallet mounting stand 151.

    [0144] The retightening processing part 150 has a configuration similar to the main sealing/swaging processing part 140 described above. That is to say, the pallet mounting stand 151 and the mounting stand elevating mechanism 151m have configurations similar to the pallet mounting stand 141 and the mounting stand elevating mechanism 141m of the main sealing/swaging processing part 140. The retightening processing part 150 includes a support shaft 150s extending in the vertical direction in an upper position of the pallet mounting stand 151, and the support shaft 150s has a cavity part 150a which opens downward in a lower end thereof. The retightening assist jig 152 is fixedly provided to the support shaft 150s so as to protrude to the cavity part 150a. These configurations are similar to the configuration manner of the support shaft 140s, the cavity part 140a, and the main sealing jig 142 in the main sealing/swaging processing part 140.

    [0145] However, a height position of an abutting part 152a of the retightening assist jig 152 is determined so that a height position of the powder compact 9a constituting the semi-assembled body 40α coincides with a height position of a claw part 153a of the second swaging jig 153 under a state that the washer 7 abuts to the abutting part 152a. A protruding length of the retightening assist jig 152 protruding from the support shaft 150s is thereby smaller than that of the main sealing jig 142 protruding from the support shaft 140s.

    [0146] The configurations of the second swaging jig 153 (the claw part 153a and a guided part 153b), a through hole 150b in which the second swaging jig 153 is disposed, and the swaging jig movement mechanism 153m for moving the second swaging jig 153 in the horizontal plane (a servo cylinder 154, a guide member 155, and the guide surface 156) are also substantially similar to those of the first swaging jig 143 (the claw part 143a and the guided part 143b), a through hole 140b in which the first swaging jig 143 is disposed, and the swaging jig movement mechanism 143m for moving the first swaging jig 143 in the horizontal plane (the servo cylinder 144, the guide member 145, and the guide surface 146). Accordingly, a detailed description of the configuration in the retightening processing part 150 is omitted.

    [0147] However, the shape of the claw part 153a of the second swaging jig 153 may differ from the shape of the claw part 143a of the first swaging jig 143. The shape of the claw part 153a of the second swaging jig 153 illustrated in Figs. 26 to 30 differs from the shape of the claw part 143a of the first swaging jig 143 illustrated in Figs. 18 to 24.

    [0148] In performing the second swaging (retightening) process in the retightening processing part 150 having the above configuration, firstly, the transportation pallet 111, which has been delivered from the main sealing/swaging processing part 140 in the third delivery position Pos3 and holds (places and fixes) the semi-assembled body 40α, is disposed in the fourth delivery position Pos4 by the pallet movement mechanism 112, and then, the transportation pallet 111 is disposed on and fixed to the pallet mounting stand 151 in the retightening processing part 150 together with the semi-assembled body 40α, by the pallet delivery mechanism 113, as shown in Fig. 26 (a step S51).

    [0149] After the transportation pallet 111 is disposed and fixed as described above, with the operation of the mounting stand elevating mechanism 151m, the pallet mounting stand 151 to which the semi-assembled body 40α is fixed is raised as indicated by an arrow AR36 in Fig. 26. When the pallet mounting stand 151 continues to be raised, the washer 7 of the semi-assembled body 40α comes to abut to the abutting part 152a of the retightening assist jig 152 in due course, as shown in Fig. 27 (a step S52). At this time, the sensor element 10 is housed in the cavity part 152b.

    [0150] After the washer 7 abuts to the abutting part 152a according to the above described manner, the servo cylinder 154 is extended vertically downward in the swaging jig movement mechanism 153m as indicated by an arrow AR37 in Fig. 27. Then, the second swaging jig 153 moves in the through hole 150b toward the inner tube 6 as indicated by an arrow AR38, and the claw part 153a of the second swaging jig 153 comes to abut to the outer periphery surface of the inner tube 6 in the lateral position of the powder compact 9a in due course as shown in Fig. 28.

    [0151] When the servo cylinder 154 is continuously extended vertically downward, as indicated by an arrow AR39, after the claw part 153a comes to abut to the outer periphery surface of the inner tube 6, the inner tube 6 is pressed by the claw part 153a. The inner tube 6 is thereby swaged from the outer periphery side, and as shown in Fig. 29, the concave portion 6b is formed in the outer periphery surface of the inner tube 6 in the lateral position of the powder compact 9a (a step S53). The constraining of the annularly-mounted member in the tubular body 30 is further secured as a result that the concave portion 6b is formed. The assembly of the assembled body 40 is finished by forming the concave portion 6b.

    [0152] After the concave portion 6b is formed, the servo cylinder 154 is shortened vertically upward as indicated by an arrow AR40 in Fig. 29. Accordingly, the second swaging jig 153 which has pressed the inner tube 6 is also taken off as indicated by an arrow AR41 (a step S54).

    [0153] After the second swaging jig 153 is taken off, the mounting stand elevating mechanism 151m operates again to lower the pallet mounting stand 151 to a default position as indicated by an arrow AR42 (a step S55). Fig. 30 illustrates a state after the pallet mounting stand 141 descends to the default position.

    [0154] Then, the transportation pallet 111 holding the assembled body 40 is delivered from the pallet mounting stand 151 to the pallet movement mechanism 112 by the pallet deliver mechanism 113 (a step S56). That is to say, the transportation pallet 111 is disposed in the fourth deliver position Pos4 again. The second swaging (retightening) process is thereby finished.

    [0155] In this preferred embodiment, the assembled body 40 constituting the main body of the gas sensor 1 is manufactured by the procedure described above. As described above, in this preferred embodiment, positioning and fixing the sensor element 10 and hermetically sealing the space of both end sides of the sensor element 10 by compressing the powder compact 9 is performed in the two stages, that is, the tentative sealing (the first compression) mainly for purpose of positioning the sensor element 10 and the main sealing (the second compression) performed after the tentative sealing without using the element positioning pin 132, and furthermore, the range of inclination or displacement of the sensor element 10 is bound by the element constraining jig 133 at the time of the tentative sealing. Accordingly, the occurrence of the defect caused by the chip (the break) or the breakage failure of the element in the sensor element 10 is appropriately suppressed inside the assembled body 40.

    [0156] The position of the element positioning pin 132 is determined in consideration of the positional deviation of the sensor element at the time of the main sealing, so that fixing of the sensor element 10 in a desired position without the chip (the break) therein as well as hermetic sealing is achieved inside the assembled body 40.

    [0157] The inventor or the present invention confirmed that an occurrence ratio of the breakage failure of the element inside the assembled body 40 (a ratio of breakage failure of the element) when the assembled body 40 is assembled without using the element constraining jig 133 at the time of the tentative sealing is 0.3 %, whereas the ratio of breakage failure of the element is reduced to 0.001 % when the element constraining jig 133 is used at the time of the tentative sealing.

    <Inspection of Assembled Body>



    [0158] The assembled body 40 having reached to completion through the retightening is provided to the inspection process performed in the inspection processing part 160, that is to say, the washer inclination inspection process (the step S6 in Fig. 5) and the subsequent continuity inspection process (the step S7 in Fig. 5).

    [0159] The washer inclination inspection process is performed in order to exclude the assembled body 40 in which the washer 7 is inclined beyond a predetermined allowable range from a manufacturing object of the gas sensor 1. The breakage failure of the element tends to occur easily in the gas sensor 1 having the washer 7 with larger inclination. It is considered that this is because, when the washer 7 is inclined, the ceramic supporter 8a which is in contact with the washer 7 is also inclined, so that even when the sensor element 10 is not inclined or displaced, the sensor element 10 comes in contact with the ceramic supporter 8a and the stress thereby acts on the sensor element 10, and the sensor element 10 is broken by the stress. This tendency is also confirmed from a result of an impact test performed on the plurality of assembled bodies 40 having different degrees of inclination of washer 7.

    [0160] In this preferred embodiment, defined as a washer inclination amount is a difference value between a maximum value and a minimum value in heights of four points in the washer 7 making 90-degree angle with each other in a circumferential direction, and the washer inclination amount is used as an index value indicating a degree of the inclination of the washer 7.

    [0161] Fig. 31 is a view exemplifying a structure of an impact test apparatus 1000 for the assembled body 40. The impact test apparatus 1000 includes a support shaft 1001 extending in the vertical direction, an arm part 1003 pivoting in a vertical plane around a pivoting center 1002 located in an upper end portion of the support shaft 1001, an attachment part 1004, to which the gas sensor 1 is attached, provided in an end portion opposite to the pivoting center 1002 in the arm part 1003, and a resin plate 1005 attached to the support shaft 1001 to abut to the attachment part 1004 when the attachment part 1004 is located in a lowermost end portion in the vertical plane.

    [0162] More specifically, the assembled body 40 is attached to the attachment part 1004 in such a posture that the longitudinal direction of the assembled body 40 is perpendicular to the vertical plane in which the arm part 1003 pivots, with the bolt portion 3a being screwed with the attachment part 1004.

    [0163] Fig. 32 is a view exemplifying a result of an impact test performed using the impact test apparatus 1000. The detail of the impact test is as follows.
    1. (1) The arm part 1003 in which the assembled body 40 is attached to the attachment part 1004 is temporarily held to have an angle θ with respect to the vertical direction.
    2. (2) When the above held state is released, the attachment part 1004 pivots as indicated by an arrow AR43 and collides with the resin plate 1005.
    3. (3) Confirmed is whether or not the sensor element 10 is broken in the assembled body 40 after the collision.
    4. (4) The processes of (1) to (3) are repeatedly performed on the assembled body 40 in which the sensor element 10 has not been broken, with a larger angle θ.


    [0164] A default value of the angle θ was set to 50° and an incremental value of the angle θ was set to 10°. A pivoting radius of the arm part 1003 was 1217 mm, and the resin plate 1005 was made of polyacetal.

    [0165] Fig. 32 shows a relationship between the angle (θ) provided to the sensor element 10 and a ratio (an occurrence rate) of the sensor element 10 which is broken at the angle for each of three levels, that is, 0 ≦ X < 0.1 mm, 0.1 mm ≦ X < 0.2 mm, and 0.2 ≦ X < 0.3 mm as the washer inclination amount (X) in the assembled body 40 being subject to the test. As can be seen from Fig. 32, the sensor element 10 tends to be broken as the washer inclination amount gets large as 0.2 mm or more. The result indicates that the washer inclination inspection process has a technical significance. The assembled body 40 in which the defect occurs as exemplified in Figs. 14B and 14C can be reliably excluded by performing the washer inclination inspection process.

    [0166] In the meanwhile, the continuity inspection process is performed in order to reliably exclude the assembled body 40 in which the breakage failure of the element occurs from the manufacturing object of the gas sensor 1. Because the conduction between the heater 70 and the electrode terminal 13 cannot be obtained in the broken sensor element 10, the assembled body 40 in which the breakage failure of the element occurs can be reliably excluded.

    [0167] Fig. 33 is a view illustrating a more specific procedure of the washer inclination inspection process and the subsequent continuity inspection process performed in the inspection processing part 160. Fig. 34 is a side view (a partial cross-sectional view) schematically illustrating a structure of the inspection processing part 160. Figs. 35A and 35B are views more specifically illustrating a positional relationship of constituent elements of the inspection processing part 160 at a time of starting the inspection process. Specifically, Fig. 35A is a partial view of Fig. 34, and Fig. 35B is a planar view of a main part corresponding to the partial view of Fig. 34. Figs. 36 and 37 are views illustrating a state halfway through the washer inclination inspection process. Figs. 38A to 38C are views illustrating a state halfway through the continuity inspection process in stages. Figs. 39A and 39B are views illustrating a relationship between a direction of the sensor element 10 and an abutting target to which each probe pin of the first conduction measurement part 163A and second conduction measurement part 163B is abutted in the continuity inspection process.

    [0168] The inspection processing part 160 mainly includes the pallet mounting stand 161, the first height measurement part 162A, the second height measurement part 162B, the first conduction measurement part 163A, the second conduction measurement part 163B, and a pair of work guides 164.

    [0169] Fig. 34 illustrates a state where the transportation pallet 111 holding (placing and fixing) the assembled body 40 is disposed on the pallet mounting stand 161. Fig. 34 also illustrates, in a manner similar to Fig. 10, a state where the assembled body 40 is disposed and fixed in the assembly posture, in which the thickness direction of the sensor element 10 coincides to the horizontal direction of Fig. 34. The state where the transportation pallet 111 to which the assembled body 40 is placed and fixed is disposed on and fixed to the pallet mounting stand 161 is also referred to simply as a state where the assembled body 40 is fixed to the pallet mounting stand 161.

    [0170] The pallet mounting stand 161 has a configuration similar to the pallet mounting stand 131 included in the tentative sealing processing part 130.

    [0171] As shown in Fig. 34, the first height measurement part 162A and the second height measurement part 162B are provided above the pallet mounting stand 161 so that they can be integrally elevated and rotated in the horizontal plane by the height measurement part drive mechanism 162m. Each of the first height measurement part 162A and the second height measurement part 162B is a dial gauge or a digital gauge, for example, and has a probe 162p extending vertically downward. The first height measurement part 162A and the second height measurement part 162B are integrally lowered by the height measurement part drive mechanism 162m, so that heights of two different positions in the upper surfaces of the washer 7 can be measured at the same time with the probe 162p provided in each of the first height measurement part 162A and the second height measurement part 162B being abutted to those positions.

    [0172] More specifically, as exemplified in Fig. 35B, the two probes 162p in the first height measurement part 162A and the second height measurement part 162B are disposed to be located above two points opposing to each other with a central axis therebetween in the upper surface of the washer 7, so that the heights of the two points can be measured at the same time.

    [0173] In the inspection processing part 160, the height measurement part drive mechanism 162m integrally rotates the first height measurement part 162A and the second height measurement part 162B in the horizontal plane, so that an array direction of the probes 162p provided in the first height measurement part 162A and the second height measurement part 162B can be changed. Accordingly. the inspection processing part 160 can measure heights of four different positions or more in the upper surface of the washer 7.

    [0174] Each of the first conduction measurement part 163A and the second conduction measurement part 163B has three probe pins 163p as shown in Fig. 35B. With these probe pins 163p being abutted to the predetermined electrode terminal 13 of the sensor element 10, the continuity inspection is performed. However, the first conduction measurement part 163A and the second conduction measurement part 163B stand by in a lateral position of the assembled body 40 until the continuity inspection process comes to be performed, as shown in Figs. 35A and 35B.

    [0175] The three probe pins 163p provided in the first conduction measurement part 163A are also referred to as probe pins pr1, pr2, and pr3 from a central portion toward an end portion in this order in planar view. The three probe pins 163p included in the second conduction measurement part 163B are also referred to as probe pins pr4, pr5, and pr6 from the central portion toward the end portion in this order in planar view.

    [0176] Only the probe pin pr2 in the three probe pins 163p provided in the first conduction measurement part 163A is disposed in a height position different from the other two probe pins. That is to say, the probe pins pr1 to pr3 are disposed so that those tip portions are not located in the same straight line, in other words, a line segment connecting the tip portions forms a triangle. In the similar manner, only the probe pin pr5 in the three probe pins 163p provided in the second conduction measurement part 163B is disposed in a height position different from the other two probe pins. That is to say, also the probe pins pr4 to pr6 are disposed so that those tip portions are not located in the same straight line, in other words, a line segment connecting the tip portions forms a triangle. The above arrangement has an effect of enhancing stability in an abutting state where the probe pins 163p abut to the sensor element 10 compared with a case where the tip portions of the three probe pins 163p are arranged in the same straight line.

    [0177] As schematically shown in Fig. 35B, the probe pins pr1 and pr2 of the first conduction measurement part 163A and the probe pins pr4 and pr5 of the second conduction measurement part 163B are electrically connected to one electrode of the resistance measuring instrument 165, and the probe pin pr3 of the first conduction measurement part 163A and the probe pin pr6 of the second conduction measurement part 163B are electrically connected to the other electrode of the resistance measuring instrument 165.

    [0178] The pair of work guides 164 is provided to abut to the sensor element 10 from both side of the sensor element 10 at the time of the continuity inspection, thereby holding and fixing the sensor element 10. The pair of work guides 164, in a manner similar to the first conduction measurement part 163A and the second conduction measurement part 163B, also stand by in a lateral position of the assembled body 40 as shown in Figs. 35A and 35B until the continuity inspection process comes to be performed.

    [0179] In performing the washer inclination inspection process and the subsequent continuity inspection process in the inspection processing part 160, firstly, the transportation pallet 111, which has been delivered from the retightening processing part 150 in the fourth delivery position Pos4 and holds (places and fixes) the assembled body 40, is disposed in the fifth delivery position Pos5 by the pallet movement mechanism 112, and then, the transportation pallet 111 is disposed on and fixed to the pallet mounting stand 161 in the inspection processing part 160 together with the assembled body 40, by the pallet delivery mechanism 113, as shown in Fig. 34 (a step S61).

    [0180] After the transportation pallet 111 is disposed and fixed as described above, heights of two points opposing to each other with the central axis therebetween in the upper surface of the washer 7 (making 180-degree angle with each other in the circumferential direction of the washer 7) are measured by the first height measurement part 162A and the second height measurement part 162B (a first measurement) (a step S62).

    [0181] Specifically, under the state that the two probes 162p provided in each of the first height measurement part 162A and the second height measurement part 162B are located above two points opposing to each other with the central axis therebetween in the upper surface of the washer 7 as shown in Fig. 35B, the height measurement part drive mechanism 162m lowers the first height measurement part 162A and the second height measurement part 162B vertically downward as indicated by an arrow AR44 in Fig. 36A, thereby causing each probe 162p to abut to the upper surface of the washer 7.

    [0182] The height position of the tip portion of each probe 162p in the abutting state is obtained as a measurement value in the first height measurement part 162A and the second height measurement part 162B in the first measurement. Each measurement value is provided to the inclination determination part 105.

    [0183] The heights of the four points in the washer 7 making 90-degree angle with each other in the circumferential direction need to be measured to obtain the inclination amount for the determination target in the washer inclination inspection process, and in the first measurement described above, the measurement at the two points opposing to each other with the sensor element 10 therebetween among such four points is achieved.

    [0184] After the first measurement is completed, the height measurement part drive mechanism 162m temporarily raises the first height measurement part 162A and the second height measurement part 162B vertically upward as indicated by an arrow AR45 in Fig. 36B to separate the probes 162p from the washer 7. Subsequently, the height measurement part drive mechanism 162m rotates the first height measurement part 162A and the second height measurement part 162B 90 degrees around a central axis O of the washer 7 (a step S63).

    [0185] Accordingly, as indicated by an arrow AR46 in Fig. 37, the position of each probe 162p of the first height measurement part 162A and the second height measurement part 162B rotates 90 degrees around the central axis O of the washer 7.

    [0186] After the rotational movement is performed, a height measurement (a second measurement) is performed on two points opposing to each other with the central axis therebetween in the upper surface of the washer 7 (facing each other in a direction perpendicular to the array direction of the probes 162p in the first measurement), in a manner similar to the above first measurement, by the first height measurement part 162A and the second height measurement part 162B at the position after the movement (a step S64). The measurement values in the first height measurement part 162A and the second height measurement part 162B at this time are also provided to the inclination determination part 105.

    [0187] After the second measurement is completed, the height measurement part drive mechanism 162m raises the first height measurement part 162A and the second height measurement part 162B vertically upward as indicated by the arrow AR45 in Fig. 36B to separate the probes 162p from the washer 7. The washer inclination inspection process is thereby finished.

    [0188] In the case that the first measurement is performed under the state that the array direction of the two probes 162p in the horizontal plane is inclined with respect to the sensor element 10, the second measurement is also performed under the state that the array direction of the two probes 162p in the horizontal plane is inclined with respect to the sensor element 10. This manner is preferable in that interference between a protruding part inside the inner tube 6 caused by providing the concave portions 6a from the four side of the outer periphery and the probe 162p descending at the time of the inclination measurement is prevented, so that the probe 162p can be reliably caused to abut to the washer 7.

    [0189] After the washer inclination inspection process is finished, the continuity inspection process is subsequently performed. Firstly, the work guide movement mechanism 164m not shown in Figs. 38A to 38C moves the pair of work guides 164 in the standby state as indicated by arrows AR47 and AR48 in Fig. 38A, thereby causing the pair of work guides 164 to hold a portion near the second tip portion 10b of the sensor element 10, as shown in Fig. 38B (a step S71).

    [0190] After the work guides 164 hold the sensor element 10, the conduction measurement part drive mechanism 163m not shown in Figs. 38A to 38C moves the first conduction measurement part 163A and the second conduction measurement part 163B, which are also in the standby state, as indicated by an arrow AR49 in Fig. 38B. Subsequently, as shown in Fig. 38C, each probe pin 163p (pr1 to pr3 and pr4 to pr6) are caused to abut to the electrode terminal 13 provided in the two main surfaces PI of the sensor element 10 to measure the resistance value (the heater resistance value) RH of the heater 70 (a step S72).

    [0191] However, there are two ways to abut the probe pins pr1 to pr3 provided in the first conduction measurement part 163A and probe pins p4 to p6 provided in the second conduction measurement part 163B, as shown in Figs. 39A and 39B, in accordance with the direction of the sensor element 10 in the assembled body 40, therefore, only one of the first conduction measurement part 163A and the second conduction measurement part 163B actually contributes to the measurement (calculation) of the heater resistance value RH.

    [0192] For example, in the case shown in Fig. 39A, the probe pins pr1, pr2, and pr3 provided in the first conduction measurement part 163A abut to the electrode terminals 13f (H+ electrode), 13g (H- electrode), and 13h (Ht electrode), respectively, so that the first conduction measurement part 163A contributes to the measurement (calculation) of the heater resistance value RH.

    [0193] In contrast, in the case shown in Fig. 39B, the probe pins pr4, pr5, and pr6 provided in the second conduction measurement part 163B abut to the electrode terminals 13f (H+ electrode), 13g (H- electrode), and 13h (Ht electrode), respectively, so that the second conduction measurement part 163B contributes to the measurement (calculation) of the heater resistance value RH.

    [0194] As described above, the reason why there are the two ways in combination of the probe pin 163p and the electrode terminal 13 to which the probe pin 163p abuts in this preferred embodiment is that, although the electrode terminals 13f (H+ electrode), 13g (H- electrode), and 13h (Ht electrode) used for calculating the heater resistance value RH are provided in only one of the two main surfaces P1 (P1a and P1b) of the sensor element 10 (the main surface P1b in the case of Figs. 3A to 3C), the two main surfaces P1a and P1b are especially not distinguished in the sequential processes described above, so that it varies depending on the individual assembled body 40 which of the first conduction measurement part 163A and the second conduction measurement part 163B the main surfaces P1a and P1b are directed to, respectively.

    [0195] Therefore, the abutting of each probe pin 163p of the first conduction measurement part 163A and the second conduction measurement part 163B according to the manner shown in Fig. 38C means that the probe pins 163p are concurrently abutted to the plurality of electrode terminals 13 which may correspond to the heater electrode terminals, regardless of which of the manner shown in Fig. 39A or 39B is achieved.

    [0196] However, as shown in Fig. 35B, since the probe pins which come to be abutted the same electrode terminal are connected to the same electrode of the resistance measuring instrument 165, the heater resistance value RH of the sensor element 10 can be obtained by the resistance measuring instrument 165 regardless of which of the first conduction measurement part 163A and the second conduction measurement part 163B contributes the actual measurement. In other words, in this preferred embodiment, the heater resistance value RH can be obtained by one measurement operation regardless of the direction of the heater electrode terminals 13 (13f (H+ electrode), 13g (H- electrode), and 13h (Ht electrode)).

    [0197] According to the above configuration of connection, the heater resistance value RH can be obtained without specifying the direction of the sensor element 10, so that the above configuration of connection is deemed to contribute to the improvement of the productivity of the gas sensor 1.

    [0198] The obtained heater resistance value RH is provided from the resistance measuring instrument 165 to the conduction determination part 106. To be exact, a resistance value R1 between the H+ electrode and the Ht electrode and a resistance value R2 between the H- electrode and the Ht electrode are directly measured by the resistance measuring instrument 165, and the heater resistance value RH is the value calculated from the equation (1) described above.

    [0199] Since the resistance values R1 and R2 reach an infinite value at the side of the probe pin 163p being abutted to the electrode terminal 13 which is not the heater electrode terminal, the value of the heater resistance value RH cannot be obtained.

    [0200] As shown in Figs. 39A and 39B, either one of the first conduction measurement part 163A and second conduction measurement part 163B does not contribute to the measurement of the heater resistance value RH. However, the manner of causing the first conduction measurement part 163A and second conduction measurement part 163B to abut to the sensor element 10 from its both sides as described above brings the effect that the state where the probe pins 163p undertaking the measurement of the heater resistance value RH abut to the sensor element 10 (more specifically, the H+ electrode, the H- electrode, and the Ht electrode) is stabilized by causing the probe pins 163p not undertaking the measurement to support the opposite side of the sensor element 10. It can be said that the probe pins 163p not contributing to the measurement of the heater resistance value RH in the first conduction measurement part 163A and second conduction measurement part 163B also function as a supporting member for stabilizing the state where the probe pins 163p contributing to the measurement of the heater resistance value RH abut to the electrode terminal, including the fact described above that the height positions of the probe pins pr2 and pr5 are different from those of the other probe pins 163p.

    [0201] After the heater resistance value RH is obtained by the resistance measuring instrument 165, the abutting of the probe pins 163p is dissolved, and subsequently, the work guides 164 are also taken off to the default standby position (a step S73).

    [0202] After the work guides 164 are taken off, the transportation pallet 111 holding the assembled body 40 is delivered from the pallet mounting stand 161 to the pallet movement mechanism 112 by the pallet deliver mechanism 113 (a step S74). That is to say, the transportation pallet 111 is disposed in the fifth deliver position Pos5 again. The inspection process is thereby finished.

    <Determination of Inspection Result>



    [0203] After the inspection process is finished, a determination processing based on an inspection result in the washer inclination inspection process and the continuity inspection process is performed for the individual assembled body 40.

    [0204] Firstly, the inclination determination part 105 performs the inclination determination processing. Specifically, the inclination determination part 105 specifies a maximum value and a minimum value in the values of the heights in the four points in the washer 7 obtained by the first measurement and the second measurement in the washer inclination inspection process, thereafter to calculate the washer inclination amount as the difference value between the maximum value and the minimum value. Subsequently, the inclination determination part 105 compares the washer inclination amount and a predetermined threshold value, and determines that the assembled body 40 has passed the washer inclination inspection when the washer inclination amount is smaller than the threshold value (YES in the step S8).

    [0205] For example, when the impact test result shown in Fig. 32 is obtained in advance, it is considered to be preferable that the threshold value of the washer inclination amount is set to 0.2 mm.

    [0206] Subsequently, the conduction determination part 106 performs the conduction determination processing for the assembled body 40 which has passed the washer inclination inspection. Specifically, the heater resistance value RH measured in the continuity inspection process for the sensor element 10 included in the assembled body 40 is compared with the predetermined threshold value, and when the heater resistance value RH is smaller than the threshold value, the conduction determination part 106 determines that the assembled body 40 has passed the continuity inspection (YES in the step S9). The result that the heater resistance value RH is larger than the threshold value indicates that the conduction is not sufficiently secured in the sensor element 10. It is likely that the breakage failure of the element occurs in the assembled body 40 for which such a result is obtained in the conduction determination processing.

    [0207] The assembled body 40 which has passed both the inclination determination processing and the continuity inspection processing is the OK product (the non-defective product), so that it is delivered to the assembled body standby part 170 so as to be provided to the process in the subsequent stages.

    [0208] In the meanwhile, the assembled body 40 which is rejected in the inclination determination processing by reason that the washer inclination amount exceeds the predetermined threshold value (NO in the step S8) and the assembled body 40 which is rejected in the continuity inspection processing by reason that the heater resistance value RH is larger than the predetermined threshold value (NO in the step S9) are the NG product (the defective product), so that they are discarded without being provided to the process in the subsequent stages.

    [0209] As described above, in this preferred embodiment, since the inclination or displacement of the sensor element 10 is limited with the usage of the element constraining jig 133 at the time of the hermetic sealing of the assembled body 40, the ratio of the breakage failure of the element in the assembled body 40 is sufficiently reduced in the first place. However, performing the inspection process described above thereby to exclude the defective product enables that the defect of the gas sensor 1 caused by the breakage of the sensor element 10 is almost certainly prevented.

    [0210] As described above, according to this preferred embodiment, the range of inclination or displacement of the sensor element is constrained by the element constraining jig at the time of the tentative sealing for fixing the sensor element with the powder compact performed in the process of manufacturing the assembled body constituting the main body of the gas sensor, so that the occurrence of the breakage failure of the element inside the assembled body can be appropriately suppressed.

    [0211] Moreover, the washer inclination inspection process is performed after completing the assembled body, so that the usage of the assembled body having the breakage failure of the element due to the washer inclination or holding a potential of having it in the future, to the gas sensor can be appropriately prevented.

    [0212] Furthermore, the washer continuity inspection process is performed after completing the assembled body, so that the usage of the assembled body having the breakage failure of the element to the gas sensor can be appropriately prevented.

    [0213] In addition, the continuity inspection process is performed subsequent to the washer inclination inspection process, so that the usage of the assembled body having the breakage failure of the element or holding a potential of having it in the future to the gas sensor can be almost certainly prevented. However, both the washer inclination inspection process and the continuity inspection process are not necessary, but only one of them may be performed as long as the usage of the assembled body having the breakage failure of the element to the gas sensor is sufficiently suppressed.


    Claims

    1. A method for manufacturing a gas sensor (1), said method including a step of obtaining an assembled body (40) constituting said gas sensor by performing a predetermined processing on a semi-assembled body (40α) which is manufactured in advance, and said semi-assembled body (40α) comprising:

    an annular-mounted assembly in which a plurality of annularly-mounted members (7, 8, 9), at least one of which is a ceramic powder compact (9), each having a disc shape or cylindrical shape are annularly mounted to a sensor element (10) with an elongated plate shape which is made of a ceramic; and

    a tubular body (30) which is annularly mounted to an outer periphery of said annularly-mounted members (7, 8, 9) and capable of engaging one end side of said annularly-mounted members therein, and

    said step of obtaining said assembled body (40) comprising steps of:

    a) causing one end of said sensor element (10) constituting said semi-assembled body (40α) to abut to a positioning member (132) for positioning said sensor element (10); and

    b) applying a first force to said annularly-mounted members (7, 8, 9) from other end side of said sensor element (10) having been positioned through said step a) and thereby compressing said powder compact (9) so as to fix said sensor element (10) inside of said tubular body (30), wherein

    said step b) is performed while constraining said sensor element (10) in a predetermined constraining region (133e) in said other end side of said sensor element (10).


     
    2. The method for manufacturing said gas sensor according to claim 1,
    said step b) comprising a step of:
    b-1) forming said constraining region (133e) with a pair of constraining jigs (133a, 133b), wherein
    said powder compact (9) is compressed after said constraining region (133e) is formed in said step b-1).
     
    3. The method for manufacturing said gas sensor according to claim 2, wherein
    in said step b-1), said constraining region (133e) is formed with said pair of constraining jigs (133a, 133b) being disposed at a predetermined distance from each other in an extending direction of said sensor element (10).
     
    4. The method for manufacturing said gas sensor according to claim 2 or 3, wherein
    said plurality of annularly-mounted members (7, 8, 9) include a plurality of ceramic insulators (8) and
    in said step b-1), a clearance between said pair of constraining jigs (133a, 133b) and said sensor element (10) is equal to or smaller than a maximum value of a gap between one of said plurality of ceramic insulators (8), which is closest to said constraining region (133e) in said plurality of ceramic insulators (8), and said sensor element (10).
     
    5. The method for manufacturing said gas sensor according to any of claims 1 to 4,
    said step of obtaining said assembled body further comprising a step of:
    c) after said step b), applying a second force which is larger than said first force to said annularly-mounted members (7, 8, 9) from said other end side of said sensor element (10) with said one end of said sensor element not abutting to said positioning member (132) and thereby further compressing said powder compact (9) so as to hermetically seal between spaces located in one end side and said other end side of said sensor element (10) inside of said tubular body (30).
     
    6. The method for manufacturing said gas sensor according to claim 5, wherein
    a posture of each of said intermediate body and said assembled body (40) in which a longitudinal direction of said sensor element (10) extends in a vertical direction and said other end side is located in an upper side is defined as an assembly posture of each of said semi-assembled body (40α) and said assembled body (40),
    said step a) is a step of causing said positioning member (132) to abut to said one end of said sensor element (10) from a lower side of said sensor element with said semi-assembled body (40α) being in said assembly posture,
    in said step b), said first force is applied to an upper portion of said annularly-mounted members (7, 8, 9) as a vertically downward force under a state that said semi-assembled body (40α) is in said assembly posture and said sensor element (10) has been positioned through said step a), so that said powder compact (9) is compressed, and said sensor element is fixed in a first position depending on a position of said positioning member (132) by said compressed powder compact, and
    in said step c), said second force is applied to said upper portion of said annularly-mounted members (7, 8, 9) in said state where said semi-assembled body (40α) is in said assembly posture.
     
    7. The method for manufacturing said gas sensor according to claim 6, wherein
    said sensor element (10) is displaced from said first position to a second position in a vertical direction through said step c), and
    said positioning member (132) is disposed in said step a) so that said second position is located within a range which is determined in advance as a position of said sensor element in said assembled body (40).
     
    8. The method for manufacturing said gas sensor according to claim 7, wherein
    in said step a), said positioning member (132) is disposed so that said second position is located within said range which is determined based on a correlation between said first position and said second position of said sensor element (10), said correlation being specified in advance.
     
    9. The method for manufacturing said gas sensor according to any of claims 5 to 8,
    said step of obtaining said assembled body (40) further comprising a step of:
    d) swaging said tubular body (30), in said state where said semi-assembled body (40α) is in said assembly posture, with a first swaging element (143) from an outer periphery thereof, in a first swaging position which is located right above an uppermost portion of said annularly-mounted members (7, 8, 9) whose powder compact (9) has been compressed in said step c).
     
    10. The method for manufacturing said gas sensor according to claim 9, wherein
    said step d) is successively performed subsequent to said step c) with said second force being kept to apply to said upper portion of said annularly-mounted members (7, 8, 9).
     
    11. The method for manufacturing said gas sensor according to claim 9 or 10,
    said step of obtaining said assembled body (40) further comprising a step of:
    e) swaging said tubular body, in said state where said semi-assembled body (40α) is in said-assembly posture, with a second swaging element (153) from an outer periphery thereof, in a second swaging position which is located in a lateral position of said powder compact (9) after said step d).
     
    12. The method for manufacturing said gas sensor according to any of claims 6 to 11,
    said annularly-mounted members (7, 8, 9) including a washer (7), and
    the method further comprising steps of:

    f) obtaining an inclination amount of said washer (7) in a state where said assembled body (40) is in said assembly posture; and

    g) determining that said assembled body (40) is a defective product when said inclination amount exceeds a predetermined threshold value.


     
    13. The method for manufacturing said gas sensor according to claim 12, wherein
    in said step f), a difference value between a maximum value and a minimum value in the values of the heights in four points in said washer (7) making 90-degree angle with each other in a circumferential direction is obtained as said inclination amount.
     
    14. The method for manufacturing said gas sensor according to claim 13, said step f) comprising steps of:

    f-1) measuring height positions of two points opposing to each other with said sensor element (10) therebetween in said four points by two height measurement elements (162p) at a time; and

    f-2) measuring height positions of remaining two points which have not been measured in said step f-1) in said four points by said two height measurement elements (162p) at a time, and
    said inclination amount is calculated based on a measurement result in said step f-1) and said step f-2).


     
    15. The method for manufacturing said gas sensor according to any of claims 6 to 14,
    said sensor element (10) including a heater (70) made up of a resistance heater therein,
    a plurality of heater electrode terminals (13f, 13g) being electrically connected to said heater (70) in said other end side, and
    the method further comprising steps of:

    h) measuring a resistance value of said heater via said plurality of heater electrode terminals of said sensor element included in said assembled body; and

    i) determining that said assembled body is a defective product when said resistance value of said heater obtained in said step h) exceeds a predetermined threshold value.


     
    16. The method for manufacturing said gas sensor according to claim 15, wherein
    said plurality of heater electrode terminals (13f, 13g) are provided only in one of two main surfaces opposing to each other of said sensor element (10), and
    in said step h), while probe pins (163p) for measurement are abutted to a plurality of electrode terminals which may correspond to said plurality of heater electrode terminals (13f, 13g) included in each of said two main surfaces with said assembled body being in said assembly posture, said resistance value of said heater (70) is measured via electrode terminals which actually correspond to said plurality of heater electrode terminals in said plurality of electrode terminals.
     
    17. The method for manufacturing said gas sensor according to claim 16, wherein
    said plurality of heater electrode terminals are three electrode terminals, and
    in said step h), three probe pins (163p) for measurement, whose end portions are not located in an identical straight line, are prepared for each side of said two main surfaces, and each of said three probe pins for measurement are abutted to either of said three electrode terminals which may correspond to said plurality of heater electrode terminals in each side of said two main surfaces.
     
    18. A gas sensor manufacturing apparatus, said apparatus including at least an element for obtaining an assembled body (40) constituting said gas sensor by performing a predetermined processing on a-semi-assembled body (40α) which is manufactured in advance, and said semi-assembled body (40α) comprising:

    an annular-mounted assembly in which a plurality of annularly-mounted members (7, 8, 9), at least one of which is a ceramic powder compact (9), each having a disc shape or cylindrical shape are annularly mounted to a sensor element (10) with an elongated plate shape which is made of a ceramic; and

    a tubular body (30) which is annularly mounted to an outer periphery of said annularly-mounted members (7, 8, 9) and capable of engaging one end side of said annularly-mounted members therein, and

    said element for obtaining said assembled body comprising:

    a positioning member (132) abutting to one end of said sensor element (10) constituting said semi-assembled body (40α) for positioning said sensor element (10);

    a first compression element (134) applying a first force to said annularly-mounted members (7, 8, 9) from other end side of said sensor element (10) which has been positioned by said positioning member (132) and thereby performing a first compression of compressing said powder compact (9); and

    a constraining element (133) capable of constraining said sensor element (10) in a predetermined constraining region (133e) in said other end side of said sensor element (10), wherein

    said first compression element (134) performs said first compression under a state that said constraining element (133) constrains said sensor element (10) in said constraining region (133e) in said other end side of said sensor element (10), thereafter to fix said sensor element (10) inside said tubular body (30).


     
    19. The gas sensor manufacturing apparatus according to claim 18, wherein said constraining element (133) is a pair of constraining jigs, and each of said pair of constraining jigs are disposed at a predetermined distance from each other in an extending direction of said sensor element (10) at the time of forming said constraining region (133e).
     
    20. The gas sensor manufacturing apparatus according to claim 18 or 19, wherein
    said plurality of annularly-mounted members (7, 8, 9) include a plurality of ceramic insulators (8), and
    said constraining region (133e) is formed so that a clearance between said constraining element (133) and said sensor element (10) is equal to or smaller than a maximum value of a gap between one of said plurality of insulators (8), which is closest to said constraining region (133e) in said plurality of insulators (8), and said sensor element (10).
     
    21. The gas sensor manufacturing apparatus according to any of claims 18 to 20,
    said first compression element (134) comprising:

    a first compression jig abutting to said annularly-mounted members (7, 8, 9) from said other end side of said sensor element (10) to apply said first force, wherein

    said first compression jig abuts to said annularly-mounted members, thereby applying said first force, while housing therein said constraining element (133) forming said constraining region (133e).


     
    22. The gas sensor manufacturing apparatus according to any of claims 18 to 21,
    said element for obtaining said assembled body (40) further comprising:
    a second compression element applying, after said first compression, a second force which is larger than said first force to said annularly-mounted members (7, 8, 9) from said other end side of said sensor element (10) with said one end of said sensor element not abutting to said positioning member (132) and thereby performing a second compression of further compressing said powder compact (9), so as to hermetically seal between spaces located on one end side and said other end side of said sensor element is performed inside of said tubular body (30).
     
    23. The gas sensor manufacturing apparatus according to claim 22, wherein
    a posture of each of said intermediate body and said assembled body in which a longitudinal direction of said sensor element (10) extends in a vertical direction and said other end side is located in an upper side is defined as an assembly posture of each of said semi-assembled body (40α) and said assembled body (40),
    said positioning member (132) abuts to said one end of said sensor element (10) from a lower side of said sensor element with said semi-assembled body (40α) being in said assembly posture,
    in said first compression, said first force is applied to an upper portion of said annularly-mounted members (7, 8, 9) as a vertically downward force under a state that said semi-assembled body (40α) is in said assembly posture and said sensor element (10) has been positioned with said positioning member (132), so that said powder compact (9) is compressed, and said sensor element (10) is fixed in a first position depending on a position of said positioning member (132) by said compressed powder compact, and
    in said second compression, said second force is applied to said upper portion of said annularly-mounted members (7, 8, 9) in said state where said semi-assembled body (40α) is in said assembly posture.
     
    24. The gas sensor manufacturing apparatus according to claim 23, wherein said sensor element (10) is displaced from said first position to a second position in a vertical direction through said second compression, and
    said positioning member (132) is disposed so that said second position is located within a range which is determined in advance as a position of said sensor element (10) in said assembled body (40).
     
    25. The gas sensor manufacturing apparatus according to claim 24, wherein said positioning member (132) is disposed so that said second position is located within said range which is determined based on a correlation between said first position and said second position of said sensor element (10), said correlation being specified in advance.
     
    26. The gas sensor manufacturing apparatus according to any of claims 22 to 25,
    said element for obtaining said assembled body further comprising:
    a first swaging element (143) performing a first swaging for swaging said tubular body (30), in said state where said semi-assembled body (40α) is in said assembly posture, from an outer periphery thereof, in a first swaging position which is located right above an uppermost portion of said annularly-mounted members (7, 8, 9) whose powder compact (9) has been compressed by said second compression.
     
    27. The gas sensor manufacturing apparatus according to claim 26, wherein
    said first compression element performs said first swaging with said second compression element keeping to apply said second force to said upper portion of said annularly-mounted members (7, 8, 9).
     
    28. The gas sensor manufacturing apparatus according to claim 26 or 27,
    said element for obtaining said assembled body further comprising:
    a second swaging element (153) performing a second swaging for swaging said tubular body (30), in said state where said semi-assembled body (40α) is in said assembly posture, from an outer periphery thereof, in a second swaging position which is located in a lateral position of said powder compact (9) after said first swaging.
     
    29. The gas sensor manufacturing apparatus according to any of claims 23 to 28,
    said annularly-mounted members including a washer (7), and
    the gas sensor manufacturing apparatus further comprising:

    an inclination amount calculation element for obtaining an inclination amount of said washer in a state where said assembled body is in said assembly posture; and

    an inclination determination element for determining that said assembled body is a defective product when said inclination amount exceeds a predetermined threshold value.


     
    30. The gas sensor manufacturing apparatus according to claim 29, wherein said inclination amount calculation element obtains a difference value between a maximum value and a minimum value in the values of the heights in four points in said washer making 90-degree angle with each other in a circumferential direction as said inclination amount.
     
    31. The gas sensor manufacturing apparatus according to claim 30, wherein
    said inclination amount calculation element is configured to perform
    a first measurement to measure height positions of two points opposing to each other with said sensor element therebetween in said four points by two height measurement elements at a time and
    a second measurement to measure height positions of remaining two points which have not been measured in said first measurement in said four points by said two height measurement elements at a time,
    thereby calculating said inclination amount based on a measurement result in said first measurement and said second measurement.
     
    32. The gas sensor manufacturing apparatus according to any of claims 23 to 31,
    said sensor element including a heater (70) made up of a resistance heater therein, and
    a plurality of heater electrode terminals (13f, 13g) being electrically connected to said heater (70) in said other end side,
    the gas sensor manufacturing apparatus further comprising:

    a resistance measurement element measuring a resistance value of said heater (70) via said plurality of heater electrode terminals (13f, 13g) of said sensor element (10) included in said assembled body (40); and

    a continuity determination element determining that said assembled body is a defective product when said resistance value of said heater (70) obtained in said resistance measurement element exceeds a predetermined threshold value.


     
    33. The gas sensor manufacturing apparatus according to claim 32, wherein
    said plurality of heater electrode terminals (13f, 13g) are provided only in one of two main surfaces opposing to each other of said sensor element (10), and
    said resistance measurement element makes probe pins (163p) for measurement abutted to a plurality of electrode terminals which may correspond to said plurality of heater electrode terminals (13f, 13g) included in each of said two main surfaces with said assembled body being in said assembly posture, and measures said resistance value of said heater (70) via electrode terminals which actually correspond to said plurality of heater electrode terminals in said plurality of electrode terminals.
     
    34. The gas sensor manufacturing apparatus according to claim 33, wherein
    said plurality of heater electrode terminals are three electrode terminals, and
    said resistance measurement element includes three probe pins (163p) for measurement, whose end portions are not located in an identical straight line, for each side of said two main surfaces, and causes each of said three probe pins for measurement to abut to either of said three electrode terminals which may correspond to plurality of heater electrode terminals in each side of said two main surfaces.
     
    35. The gas sensor manufacturing apparatus according to any of claims 18 to 34, further comprising:

    a first annularly-mounting mechanism for annularly mounting said plurality of annularly-mounted members to said sensor element (10) to obtain said annularly-mounted assembly; and

    a second annularly-mounting mechanism for annularly mounting said tubular body (30) to said outer periphery of said annularly-mounted assembly to obtain said semi-assembled body (40α).


     


    Ansprüche

    1. Verfahren zur Herstellung eines Gassensors (1), wobei das Verfahren einen Schritt umfasst, bei dem durch Ausführen einer vorgegebenen Verarbeitung eines teilfertigen Körpers (40α), der im Voraus hergestellt wird, ein den Gassensor bildender fertiger Körper (40) erhalten wird, und der teilfertige Körper (40α) Folgendes umfasst:

    eine ringförmig angebrachte Anordnung, wobei eine Vielzahl von ringförmig angebrachten Elementen (7, 8, 9), von denen zumindest eines ein Keramikpulverpressling (9) ist, alle scheibenförmig oder zylindrisch, ringförmig an einem Sensorelement (10) mit einer länglichen Plattenform aus Keramik angebracht wird; und

    ein rohrförmiger Körper (30), der ringförmig am Außenumfang der ringförmig angebrachten Elemente (7, 8, 9) angebracht ist und in der Lage ist, eine Endseite der ringförmig angebrachten Elemente in diesem in Eingriff zu bringen, und

    wobei der Schritt des Erhaltens des fertigen Körpers (40) die folgenden Schritte umfasst:

    a) das Herbeiführen, dass ein Ende des Sensorelements (10), das den teilfertigen Körper (40α) bildet, an ein Positionierungselement (132) zum Positionieren des Sensorelements (10) anstößt; und

    b) das Aufbringen einer ersten Kraft auf die ringförmig angebrachten Elemente (7, 8, 9) von der anderen Endseite des Sensorelements (10), das durch den Schritt a) angeordnet wurde, und dadurch Verdichten des Pulverpresslings (9) zur Fixierung des Sensorelements (10) innerhalb des rohrförmigen Körpers (30), wobei der Schritt b) ausgeführt wird, während das Sensorelement (10) in einem vorgegebenen Einschränkungsbereich (133e) auf der anderen Endseite des Sensorelements (10) eingeschränkt wird.


     
    2. Verfahren zur Herstellung eines Gassensors nach Anspruch 1, wobei der Schritt b) folgenden Schritt umfasst:
    b-1) das Bilden eines Einschränkungsbereichs (133e) mit einem Paar von Einschränkungsspannvorrichtungen (133a, 133b), wobei
    der Pulverpressling (9) nach dem Bilden des Einschränkungsbereichs (133e) in Schritt b-1) komprimiert wird.
     
    3. Verfahren zur Herstellung eines Gassensors nach Anspruch 2, wobei
    in Schritt b-1) der Einschränkungsbereich (133e) mit dem Paar von Einschränkungsspannvorrichtungen (133a, 133b) gebildet wird, die in einem vorgegebenen Abstand voneinander in einer Erstreckungsrichtung des Sensorelements (10) vorgesehen sind.
     
    4. Verfahren zur Herstellung eines Gassensors nach Anspruch 2 oder 3, wobei
    die Vielzahl ringförmig angebrachter Elemente (7, 8, 9) eine Vielzahl von Keramikisolatoren (8) einschließt und
    in dem Schritt b-1) ein Freiraum zwischen dem Paar von Einschränkungsvorrichtungen (133a, 133b) und dem Sensorelement (10) gleich einem oder kleiner als ein Maximalwert eines Spalts zwischen einem der Vielzahl von Keramikisolatoren (8), der dem Einschränkungsbereich (133e) der Vielzahl von Keramikisolatoren (8) am nächsten ist, und dem Sensorelement (10) ist.
     
    5. Verfahren zur Herstellung eines Gassensors nach einem der Ansprüche 1 bis 4,
    wobei der Schritt zum Erhalten des fertigen Körpers ferner den folgenden Schritt umfasst:
    c) nach dem Schritt b) das Aufbringen einer zweiten Kraft, die größer als die erste Kraft ist, auf die ringförmig angebrachten Elemente (7, 8, 9) von der anderen Endseite des Sensorelements (10) mit dem einen Ende des Sensorelements, das nicht an das Positionierungselement (132) anstößt, und dadurch das weitere Verdichten des Pulverpresslings (9), sodass Hohlräume in einer Endseite und der anderen Endseite des Sensorelements (10) in dem rohrförmigen Körper (30) hermetisch abgedichtet werden.
     
    6. Verfahren zur Herstellung eines Gassensors nach Anspruch 5, wobei eine räumliche Lage sowohl des Zwischenkörpers als auch des fertigen Körpers (40), in der sich eine Längsrichtung des Sensorelements (10) in einer vertikalen Richtung erstreckt und die andere Endseite in einer oberen Seite angeordnet ist, als eine Assemblierungslage sowohl des teilfertigen Körpers (40α) als auch des fertigen Körpers (40) definiert wird,
    der Schritt a) ein Schritt ist, der herbeiführt, dass das Positionierungselement (132) an das eine Ende des Sensorelements (10) von einer unteren Seite des Sensorelements anstößt, wobei sich der teilfertige Körper (40α) in der Assemblierungslage befindet,
    in dem Schritt b) die erste Kraft auf einen oberen Abschnitt der ringförmig angebrachten Elemente (7, 8, 9) als eine vertikal nach unten gerichtete Kraft in einem Zustand aufgebracht wird, in dem sich der teilfertige Körper (40α) in der Assemblierungslage befindet und das Sensorelement (10) durch den Schritt a) positioniert worden ist, so dass der Pulverpressling verdichtet wird und das Sensorelement in einer ersten Position in Abhängigkeit von einer Position des Positionierungselements (132) durch den verdichteten Pulverpressling fixiert wird, und
    in dem Schritt c) die zweite Kraft auf den oberen Abschnitt der ringförmig angebrachten Elemente (7, 8, 9) aufgebracht wird, in dem Zustand, bei dem sich der teilfertige Körper (40α) in der Assemblierungslage befindet.
     
    7. Verfahren zur Herstellung eines Gassensors nach Anspruch 6, wobei
    das Sensorelement (10) durch den Schritt c) aus der ersten Position in eine zweite Position in vertikaler Richtung verschoben wird
    und das Positionierungselement in Schritt a) so angeordnet ist, dass die zweite Position innerhalb eines Bereichs liegt, der im Voraus als Position des Sensorelements in dem fertigen Körper (40) bestimmt wird.
     
    8. Verfahren zur Herstellung eines Gassensors nach Anspruch 7, wobei
    in dem Schritt a), das Positionierungselement (132) so angeordnet ist, dass die zweite Position innerhalb des Bereichs liegt, der auf Basis einer Korrelation zwischen der ersten Position und der zweiten Position des Sensorelements (10) bestimmt wird, wobei die Korrelation im Voraus festgelegt wird.
     
    9. Verfahren zur Herstellung eines Gassensors nach einem der Ansprüche 5 bis 8,
    wobei der Schritt des Erhaltens des fertigen Körpers (40) ferner folgenden Schritt umfasst:
    d) Stauchen des rohrförmigen Körpers (30) in dem Zustand, bei dem sich der teilfertige Körper (40α) in der Assemblierungslage befindet, mit einem ersten Stempelelement (143) von einem Außenumfang desselben, in einer ersten Stauchungsposition, die sich direkt über einem obersten Abschnitt der ringförmig angebrachten Elemente (7, 8, 9) befindet, deren Pulverpressling (9) in Schritt c) verdichtet wurde.
     
    10. Verfahren zur Herstellung eines Gassensors nach Anspruch 9, wobei
    der Schritt d) nach dem Schritt c) nacheinander durchgeführt wird, wobei die zweite Kraft weiterhin auf den oberen Abschnitt der ringförmig angeordneten Elemente (7, 8, 9) aufgebracht wird.
     
    11. Verfahren zur Herstellung eines Gassensors nach Anspruch 9 oder 10, wobei der Schritt des Erhaltens des fertigen Körpers (40) ferner folgenden Schritt umfasst:
    e) Stauchen des rohrförmigen Körpers in dem Zustand, bei dem der teilfertige Körper (40α) sich in der Assemblierungslage befindet, mit einem zweiten Stempelelement (153) von einem Außenumfang desselben, in einer zweiten Stauchungsposition, die sich in einer seitlichen Position des Pulverpresslings (9) befindet, nach dem Schritt d).
     
    12. Verfahren zur Herstellung eines Gassensors nach einem der Ansprüche 6 bis 11,
    wobei die ringförmig angebrachten Elemente (7, 8, 9) eine Unterlegscheibe (7) umfassen, und
    das Verfahren ferner folgende Schritte umfasst:

    f) Erhalten eines Neigungsausmaßes der Unterlegscheibe (7) in einem Zustand, bei dem sich der fertige Körper (40) in der Assemblierungslage befindet; und

    g) Bestimmen, dass der fertige Körper (40) ein fehlerhaftes Erzeugnis ist, wenn das Neigungsausmaß einen vorgegebenen Grenzwert übersteigt.


     
    13. Verfahren zur Herstellung eines Gassensors nach Anspruch 12, wobei
    in Schritt f) ein Differenzwert zwischen einem Maximalwert und einem Minimalwert der Werte der Höhen in vier Punkten in der Unterlegscheibe (7), die einen 90-Grad-Winkel miteinander in einer Umfangsrichtung bilden, als Neigungsausmaß erhalten wird.
     
    14. Verfahren zur Herstellung eines Gassensors nach Anspruch 13, wobei der Schritt f) folgende Schritte umfasst:

    f-1) Messen von Höhenpositionen von zwei einander gegenüberliegenden Punkten mit dem Sensorelement (10) dazwischen in den vier Punkten durch jeweils zwei Höhenmesselemente (162p) zu einem Zeitpunkt; und

    f-2) Messen von Höhenpositionen der verbleibenden zwei Punkte, die in Schritt f-1) nicht gemessen wurden, in den vier Punkten jeweils durch die beiden Höhenmesselemente (162p) zu einem Zeitpunkt, und
    das Neigungsausmaß auf der Basis eines Messergebnisses aus Schritt f-1) und Schritt f-2) berechnet wird.


     
    15. Verfahren zur Herstellung eines Gassensors nach einem der Ansprüche 6 bis 14,
    wobei das Sensorelement (10) eine Heizvorrichtung (70) enthält, die aus einer Widerstandsheizvorrichtung darin besteht,
    wobei eine Vielzahl von Heizelektrodenanschlüssen (13f, 13g) elektrisch mit der Heizvorrichtung (70) an der anderen Endseite verbunden ist, und
    wobei das Verfahren ferner die folgenden Schritte umfasst:

    h) Messen eines Widerstandwerts der Heizvorrichtung über die Vielzahl von Heizelektrodenanschlüssen des Sensorelements, die der fertige Körper umfasst; und

    i) Bestimmen, dass der fertige Körper ein fehlerhaftes Erzeugnis ist, wenn der Widerstandswert der in dem Schritt h) erhaltenen Heizvorrichtung einen vorgegebenen Grenzwert überschreitet.


     
    16. Verfahren zur Herstellung eines Gassensors nach Anspruch 15, wobei
    die Vielzahl von Heizelektrodenanschlüssen (13f, 13g) nur auf einer von zwei einander gegenüberliegenden Hauptoberflächen des Sensorelements (10) bereitgestellt ist, und
    in dem Schritt h), wobei Taststifte (163p) zur Messung an eine Vielzahl von Elektrodenanschlüssen zur Anlage gebracht werden, die der Vielzahl von Heizelektrodenanschlüssen (13f, 13g) entsprechen können, die jede der beiden Hauptoberflächen mit dem fertigen Körper umfasst, der sich in der Assemblierungslage befindet, der Widerstandswert der Heizvorrichtung (70) über Elektrodenanschlüsse, die tatsächlich der Vielzahl von Heizelektrodenanschlüssen in der Vielzahl von Elektrodenanschlüssen entsprechen, gemessen wird.
     
    17. Verfahren zur Herstellung eines Gassensors nach Anspruch 16, wobei
    die Vielzahl von Heizelektrodenanschlüssen drei Elektrodenanschlüsse sind, und
    in dem Schritt h) drei Taststifte (163p) zur Messung, deren Endabschnitte nicht in einer identischen geraden Linie liegen, für jede Seite der beiden Hauptoberflächen hergestellt werden, und jeder der drei Taststifte zur Messung an einen der drei Elektrodenanschlüsse zur Anlage gebracht wird, die der Vielzahl von Heizelektrodenanschlüssen auf jeder Seite der beiden Hauptoberflächen entsprechen können.
     
    18. Vorrichtung zur Herstellung eines Gassensors, wobei die Vorrichtung zumindest ein Element zum Erhalten eines fertigen Körpers (40) umfasst, der den Gassensor bildet, durch Ausführen einer vorgegebenen Verarbeitung eines teilfertigen Körpers (40α), der im Voraus hergestellt wird, und der teilfertige Körper (40α) Folgendes umfasst:

    eine ringförmig angebrachte Anordnung, in der eine Vielzahl von ringförmig angebrachten Elementen (7, 8, 9), wovon zumindest eines ein Keramikpulverpressling (9) ist und jedes davon scheibenförmig oder zylindrisch ist, ringförmig an ein Sensorelement (10) in Form einer länglichen Platte aus Keramik angebracht ist; und

    ein rohrförmiger Körper (30), der ringförmig an einem Außenumfang der ringförmig angebrachten Elemente (7, 8, 9) angebracht ist und eine Endseite der ringförmig angebrachten Elemente darin in Eingriff bringen kann, und

    das Element zum Erhalten des fertigen Körpers Folgendes umfasst:

    ein Positionierungselement (132), das an ein Ende des Sensorelements (10), das den teilfertigen Körper (40α) bildet, anstößt, um das Sensorelement (10) zu positionieren;

    ein erstes Verdichtungselement (134), das eine erste Kraft auf die ringförmig angebrachten Elemente (7, 8, 9) von der anderen Endseite des Sensorelements (10) aufbringt, das durch das Positionierungselement (132) positioniert wurde, und somit durch die Verdichtung des Pulverpresslings (9) eine erste Verdichtung durchführt; und

    ein Einschränkungselement (133), das in der Lage ist, das Sensorelement (10) in einem vorgegebenen Einschränkungsbereich (133e) auf der anderen Endseite des Sensorelements (10) einzuschränken, wobei

    das erste Verdichtungselement (134) die erste Verdichtung in einem Zustand ausführt, in dem das Einschränkungselement (133) das Sensorelement (10) in dem Einschränkungsbereich (133e) auf der anderen Endseite des Sensorelements (10) einschränkt, um danach das Sensorelement (10) innerhalb des rohrförmigen Körpers (30) zu fixieren.


     
    19. Vorrichtung zur Herstellung eines Gassensors nach Anspruch 18, wobei das Einschränkungselement (133) aus einem Paar von Einschränkungsspannvorrichtungen besteht, und jede des Paars von Einschränkungsvorrichtungen in einem vorgegebenen Abstand voneinander in einer Erstreckungsrichtung des Sensorelements (10) zum Zeitpunkt der Bildung des Einschränkungsbereichs (133e) angeordnet ist.
     
    20. Vorrichtung zur Herstellung eines Gassensors nach Anspruch 18 oder 19, wobei
    die Vielzahl von ringförmig angebrachten Elementen (7, 8, 9) eine Vielzahl von Keramikisolatoren (8) umfasst, und
    der Einschränkungsbereich (133e) so gebildet wird, dass zwischen dem Einschränkungselement (133) und dem Sensorelement (10) ein Abstand gleich oder kleiner als ein Maximalwert eines Spalts zwischen einem der Vielzahl von Isolatoren (8), der dem Einschränkungsbereich (133e) in der Vielzahl von Isolatoren (8) am nächsten ist, und dem Sensorelement (10) ist.
     
    21. Vorrichtung zur Herstellung eines Gassensors nach einem der Ansprüche 18 bis 20,
    wobei das erste Verdichtungselement (134) Folgendes umfasst:

    eine erste Verdichtungsvorrichtung, die an die ringförmig angeordneten Elemente (7, 8, 9) von der anderen Endseite des Sensorelements (10) anstößt, um die erste Kraft aufzubringen, wobei

    die erste Verdichtungsvorrichtung an die ringförmig angebrachten Elemente anstößt und dadurch die erste Kraft aufbringt, während darin das Einschränkungselement (133) aufgenommen ist, das den Einschränkungsbereich (133e) bildet.


     
    22. Vorrichtung zur Herstellung eines Gassensors nach einem der Ansprüche 18 bis 21,
    wobei das Element zum Erhalten des fertigen Körpers (40) ferner Folgendes umfasst:
    ein zweites Verdichtungselement, das nach der ersten Verdichtung von der anderen Endseite des Sensorelements (10) mit dem einen Ende des Sensorelements, das nicht an das Positionierungselement (132) anstößt, eine zweite Kraft auf die ringförmig angebrachten Elemente (7, 8, 9) aufbringt, die größer als die erste Kraft ist, und dadurch durch weitere Verdichtung des Pulverpresslings (9) eine zweite Verdichtung ausführt, sodass Hohlräume, die sich an einer Endseite befinden, hermetisch abgedichtet werden und die andere Endseite des Sensorelements innerhalb des rohrförmigen Körpers ausgeführt wird.
     
    23. Vorrichtung zur Herstellung eines Gassensors nach Anspruch 22, wobei
    eine räumliche Lage eines jeden Zwischenkörpers und des fertigen Körpers, in dem sich eine Längsrichtung des Sensorelements (10) in einer vertikalen Richtung erstreckt und sich die andere Endseite in einer oberen Seite befindet, als Assemblierungslage eines jeden teilfertigen Körpers (40α) und dem fertigen Körper (40) definiert wird,
    das Positionierungselement (132) von einer unteren Seite des Sensorelements an das eine Ende des Sensorelements (10) anstößt, während sich der teilfertige Körper (40α) in der Assemblierungslage befindet,
    die erste Kraft in der ersten Verdichtung als eine vertikal nach unten gerichtete Kraft auf einen oberen Abschnitt der ringförmig angebrachten Elemente (7, 8, 9) aufgebracht wird, in einem Zustand, bei dem der teilfertige Körper (40α) sich in der Assemblierungslage befindet und das Sensorelement (10) mit dem Positionierelement (132) positioniert wurde, sodass der Pulverpressling (9) verdichtet wird, und das Sensorelement (10) durch den verdichteten Pulverpressling in einer ersten Position fixiert wird, die von einer Position des Positionierelements (132) abhängt, und
    die zweite Kraft in der zweiten Verdichtung auf den oberen Abschnitt der ringförmig angebrachten Elemente (7, 8, 9) aufgebracht wird, in einem Zustand, bei dem der teilfertige Körper (40α) sich in der Assemblierungslage befindet.
     
    24. Vorrichtung zur Herstellung eines Gassensors nach Anspruch 23, wobei
    das Sensorelement (10) durch die zweite Verdichtung in einer vertikalen Richtung von einer ersten Position in eine zweite Position verschoben wird, und
    das Positionierungselement (132) so angeordnet ist, dass die zweite Position innerhalb des Bereichs liegt, der im Voraus als Position des Sensorelements (10) in dem teilfertigen Körper (40) bestimmt wird.
     
    25. Vorrichtung zum Herstellen eines Gassensors nach Anspruch 24, wobei
    das Positionierungselement (132) so angeordnet ist, dass die zweite Position innerhalb des Bereichs liegt, der auf Basis einer Korrelation zwischen der ersten Position und der zweiten Position des Sensorelements (10) bestimmt wird, wobei die Korrelation im Voraus festgelegt wird.
     
    26. Vorrichtung zum Herstellen eines Gassensors nach einem der Ansprüche 22 bis 25,
    wobei das Element zum Erhalten des fertigen Körpers ferner Folgendes umfasst:
    ein erstes Stempelelement (143), das ein erstes Stauchen ausführt, um den rohrförmigen Körper (30) zu stauchen, und zwar in dem Zustand, bei dem der teilfertige Körper (40α) sich in der Assemblierungslage befindet, von einem Außenumfang desselben, in eine erste Stauchungsposition, die direkt über einem obersten Abschnitt der ringförmig angeordneten Elemente (7, 8, 9) liegt und dessen Pulverpressling (9) durch die zweite Verdichtung verdichtet wurde.
     
    27. Vorrichtung zum Herstellen eines Gassensors nach Anspruch 26, wobei
    das erste Verdichtungselement das erste Stauchen ausführt, während das zweite Verdichtungselement die zweite Kraft weiterhin auf den obersten Abschnitt der ringförmig angebrachten Elemente (7, 8, 9) aufbringt.
     
    28. Vorrichtung zum Herstellen eines Gassensors nach einem der Ansprüche 26 oder 27,
    wobei das Element zum Erhalten des fertigen Körpers ferner Folgendes umfasst:
    ein zweites Stempelelement (153), das ein zweites Stauchen ausführt, um den rohrförmigen Körper (30) zu stauchen, und zwar in dem Zustand, bei dem der teilfertige Körper (40α) sich in der Assemblierungslage befindet, von einem Außenumfang desselben, in eine zweite Stauchungsposition, die nach dem ersten Stauchen in einer seitlichen Position des Pulverpresslings (9) liegt.
     
    29. Vorrichtung zur Herstellung eines Gassensors nach einem der Ansprüche 23 bis 28,
    wobei die ringförmig angebrachten Elemente eine Unterlegscheibe (7) umfassen, und
    die Vorrichtung zur Herstellung eines Gassensors ferner Folgendes umfasst:

    ein Berechnungselement des Neigungsausmaßes zum Erhalten eines Neigungsausmaßes der Unterlegscheibe in einem Zustand, bei dem sich der fertige Körper in der Assemblierungslage befindet; und

    ein Neigungsbestimmungselement zur Bestimmung des fertigen Körpers als ein fehlerhaftes Erzeugnis, wenn das Neigungsausmaß einen vorgegebenen Grenzwert überschreitet.


     
    30. Vorrichtung zum Herstellen eines Gassensors nach Anspruch 29, wobei
    das Berechnungselement des Neigungsausmaßes einen Differenzwert zwischen einem Maximalwert und einem Minimalwert der Werte der Höhen in der Unterlegscheibe in vier Punkten, die in einer Umfangsrichtung einen 90-Grad-Winkel miteinander bilden, als Neigungsausmaß erhält.
     
    31. Vorrichtung zum Herstellen eines Gassensors nach Anspruch 30, wobei
    das Berechnungselement des Neigungsausmaßes so konfiguriert ist, dass es
    eine erste Messung ausführt, um die Höhenpositionen zweier Punkte zu messen, die einander, mit dem Sensorelement dazwischen, gegenüber liegen, mit jeweils zwei Höhenmesselementen gleichzeitig in den vier Punkten, und
    eine zweite Messung ausführt, um die Höhenpositionen der übrigen zwei Punkte zu messen, die in der ersten Messung noch nicht gemessen wurden, mit jeweils zwei Höhenmesselementen gleichzeitig in den vier Punkten,
    und dadurch das Neigungsausmaß auf Basis eines Messergebnisses in der ersten Messung und in der zweiten Messung berechnet wird.
     
    32. Vorrichtung zum Herstellen eines Gassensors nach einem der Ansprüche 23 bis 31,
    wobei das Sensorelement eine Heizvorrichtung (70) umfasst, die aus einer Widerstandsheizvorrichtung darin besteht, und
    eine Vielzahl von Heizelektrodenanschlüssen (13f, 13g) elektrisch mit der Heizvorrichtung (70) an der anderen Endseite verbunden wird,
    und die Vorrichtung zur Herstellung eines Gassensors ferner Folgendes umfasst:

    ein Widerstandsmesselement, das über eine Vielzahl von Heizelektrodenanschlüssen (13f, 13g) des Sensorelements (10), das der fertige Körper (40) umfasst, einen Widerstandswert der Heizvorrichtung (70) misst; und

    ein Kontinuitätsbestimmungselement, das den fertigen Körper als fehlerhaftes Erzeugnis bestimmt, wenn der durch das Widerstandsmesselement erhaltene Widerstandswert der Heizvorrichtung (70) einen vorgegebenen Grenzwert überschreitet.


     
    33. Vorrichtung zur Herstellung eines Gassensors nach Anspruch 32, wobei
    die Vielzahl von Heizelektrodenanschlüssen (13f, 13g) nur auf einer von zwei einander gegenüberliegenden Hauptoberflächen des Sensorelements (10) bereitgestellt ist, und
    das Widerstandsmesselement Taststifte (163p) zur Messung an eine Vielzahl von Elektrodenanschlüssen in Anlage bringt, was der Vielzahl von Heizelektrodenanschlüssen (13f, 13g), die jede der beiden Hauptoberflächen umfasst, während sich der fertige Körper in der Assemblierungslage befindet, entsprechen kann, und den Widerstandswert der Heizvorrichtung (70) über Elektrodenanschlüsse misst, die tatsächlich der Vielzahl von Heizelektrodenanschlüssen in der Vielzahl von Elektrodenanschlüssen entsprechen.
     
    34. Vorrichtung zur Herstellung eines Gassensors nach Anspruch 33, wobei
    die Vielzahl von Heizelektrodenanschlüssen drei Elektrodenanschlüsse sind, und
    das Widerstandsmesselement für jede Seite der beiden Hauptoberflächen drei Taststifte (163p) zur Messung umfasst, deren Endabschnitte nicht in einer identischen geraden Linie liegen, und jeden der drei Taststifte zur Messung an einen der drei Elektrodenanschlüsse anstoßen lässt, die der Vielzahl von Heizelektrodenanschlüssen auf jeder Seite der beiden Hauptoberflächen entsprechen können.
     
    35. Vorrichtung zur Herstellung eines Gassensors nach einem der Ansprüche 18 bis 34, ferner umfassend:

    einen ersten Mechanismus zum ringförmigen Anbringen, um die Vielzahl von ringförmig angebrachten Elementen an das Sensorelement (10) ringförmig anzubringen, um die ringförmig angebrachte Anordnung zu erhalten; und

    einen zweiten Mechanismus zum ringförmigen Anbringen, um den rohrförmigen Körper (30) am Außenumfang der ringförmig angebrachten Anordnung ringförmig anzubringen, um den teilfertigen Körper (40α) zu erhalten.


     


    Revendications

    1. Procédé pour fabriquer un capteur de gaz (1), ledit procédé comprenant une étape consistant à obtenir un corps assemblé (40) constituant ledit capteur de gaz en réalisant un traitement prédéterminé sur un corps semi-assemblé (40α) qui est fabriqué à l'avance, et ledit corps semi-assemblé (40α) comprenant :

    un ensemble monté annulaire dans lequel une pluralité d'éléments montés de manière annulaire (7, 8, 9), dont au moins l'un est un comprimé de poudre en céramique (9), ayant chacun une forme de disque ou une forme cylindrique, sont montés de manière annulaire sur un élément de capteur (10) avec une forme de plaque allongée, qui est réalisé avec une céramique ; et

    un corps tubulaire (30) qui est monté de manière annulaire sur une périphérie externe desdits éléments montés de manière annulaire (7, 8, 9) et pouvant se mettre en prise sur un côté d'extrémité desdits éléments montés de manière annulaire dans ce dernier, et

    ladite étape consistant à obtenir ledit corps assemblé (40) comprenant les étapes consistant à :

    a) amener une extrémité dudit élément de capteur (10) constituant ledit corps semi-assemblé (40α) à venir en butée contre un élément de positionnement (132) pour positionner ledit élément de capteur (10) ; et

    b) appliquer une première force sur lesdits éléments montés de manière annulaire (7, 8, 9) à partir de l'autre côté d'extrémité dudit élément de capteur (10) qui a été positionné par le biais de ladite étape a) et compresser ainsi ledit comprimé de poudre (9) afin de fixer ledit élément de capteur (10) à l'intérieur dudit corps tubulaire (30), dans lequel :

    ladite étape b) est réalisée tout en contraignant ledit élément de capteur (10) dans une région de contrainte (133e) prédéterminée dans ledit autre côté d'extrémité dudit élément de capteur (10).


     
    2. Procédé pour fabriquer ledit capteur de gaz selon la revendication 1,
    ladite étape b) comprenant une étape consistant à :
    b-1) former ladite région de contrainte (133e) avec une paire de gabarits de contrainte (133a, 133b), dans lequel :
    ledit comprimé de poudre (9) est comprimé après que ladite région de contrainte (133e) a été formée à ladite étape b-1).
     
    3. Procédé pour fabriquer ledit capteur de gaz selon la revendication 2, dans lequel :
    à ladite étape b-1), ladite région de contrainte (133e) est formée avec ladite paire de gabarits de contrainte (133a, 133b) qui sont disposés à une distance prédéterminée l'un de l'autre dans une direction d'extension dudit élément de capteur (10).
     
    4. Procédé pour fabriquer ledit capteur de gaz selon la revendication 2 ou 3, dans lequel :

    ladite pluralité d'éléments montés de manière annulaire (7, 8, 9) comprend une pluralité d'isolants en céramique (8), et

    à ladite étape b-1), un jeu entre ladite paire de gabarits de contrainte (133a, 133b) et ledit élément de capteur (10) est égal ou inférieur à une valeur maximum d'un espace entre l'un de ladite pluralité d'isolants en céramique (8), qui est le plus proche de ladite région de contrainte (133e) dans ladite pluralité d'isolants en céramique (8), et ledit élément de capteur (10).


     
    5. Procédé pour fabriquer ledit capteur de gaz selon l'une quelconque des revendications 1 à 4,
    ladite étape consistant à obtenir ledit corps assemblé comprenant en outre une étape consistant à :
    c) après ladite étape b), appliquer une seconde force qui est supérieure à ladite première force sur lesdits éléments montés de manière annulaire (7, 8, 9) à partir dudit autre côté d'extrémité dudit élément de capteur (10) avec ladite une extrémité dudit élément de capteur qui ne vient pas en butée contre ledit élément de positionnement (132) et ainsi compresser en outre ledit comprimé de poudre (9) afin de réaliser un scellement hermétique entre les espaces situés dans un côté d'extrémité et ledit autre côté d'extrémité dudit élément de capteur (10) à l'intérieur dudit corps tubulaire (30).
     
    6. Procédé pour fabriquer ledit capteur de gaz selon la revendication 5, dans lequel :

    une posture de chacun parmi ledit corps intermédiaire et ledit corps assemblé (40) dans laquelle une direction longitudinale dudit élément de capteur (10) s'étend dans une direction verticale et ledit autre côté d'extrémité est situé dans un côté supérieur, est définie comme étant une posture d'assemblage de chacun parmi ledit corps semi-assemblé (40α) et ledit corps assemblé (40),

    ladite étape a) est une étape consistant à amener ledit élément de positionnement (132) à venir en butée contre ladite une extrémité dudit élément de capteur (10) à partir d'un côté inférieur dudit élément de capteur avec ledit corps semi-assemblé (40α) qui est dans ladite posture d'assemblage,

    à ladite étape b), ladite première force est appliquée sur une partie supérieure desdits éléments montés de manière annulaire (7, 8, 9) en tant que force verticalement descendante dans un état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage et ledit élément de capteur (10) a été positionné par le biais de ladite étape a), de sorte que ledit comprimé de poudre (9) est compressé, et ledit élément de capteur est fixé dans une première position dépendant d'une position dudit élément de positionnement (132) par ledit comprimé de poudre compressé, et

    à ladite étape c), ladite seconde force est appliquée sur ladite partie supérieure desdits éléments montés de manière annulaire (7, 8, 9) dans ledit état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage.


     
    7. Procédé pour fabriquer ledit capteur de gaz selon la revendication 6, dans lequel :

    ledit élément de capteur (10) est déplacé de ladite première position à une seconde position dans une direction verticale par le biais de ladite étape c), et

    ledit élément de positionnement (132) est disposé à ladite étape a) de sorte que ladite seconde position est située dans une plage qui est déterminée à l'avance comme étant une position dudit élément de capteur dans ledit corps assemblé (40).


     
    8. Procédé pour fabriquer ledit capteur de gaz selon la revendication 7, dans lequel :
    à ladite étape a), ledit élément de positionnement (132) est disposé de sorte que ladite seconde position est positionnée dans ladite plage qui est déterminée sur la base d'une corrélation entre ladite première position et ladite seconde position dudit élément de capteur (10), ladite corrélation étant spécifiée à l'avance.
     
    9. Procédé pour fabriquer ledit capteur de gaz selon l'une quelconque des revendications 5 à 8,
    ladite étape consistant à obtenir ledit corps assemblé (40) comprenant en outre une étape consistant à :
    d) emboutir ledit corps tubulaire (30), dans ledit état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage, avec un premier élément d'emboutissage (143) à partir de sa périphérie externe, dans une première position d'emboutissage qui est positionnée juste au-dessus de la partie la plus haute desdits éléments montés de manière annulaire (7, 8, 9) dont le comprimé de poudre (9) a été compressé à ladite étape c).
     
    10. Procédé pour fabriquer ledit capteur de gaz selon la revendication 9, dans lequel :
    ladite étape d) est réalisée successivement après ladite étape c) avec ladite seconde force qui est conservée pour être appliquée sur ladite partie supérieure desdits éléments montés de manière annulaire (7, 8, 9).
     
    11. Procédé pour fabriquer ledit capteur de gaz selon la revendication 9 ou 10,
    ladite étape consistant à obtenir ledit corps assemblé (40) comprenant en outre une étape consistant à :
    e) emboutir ledit corps tubulaire dans ledit état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage, avec un second élément d'emboutissage (153) à partir de sa périphérie externe, dans une seconde position d'emboutissage qui est positionnée dans une position latérale dudit comprimé de poudre (9) après ladite étape d).
     
    12. Procédé pour fabriquer ledit capteur de gaz selon l'une quelconque des revendications 6 à 11,
    lesdits éléments montés de manière annulaire (7, 8, 9) comprenant une rondelle (7), et
    le procédé comprenant en outre les étapes consistant à :

    f) obtenir une quantité d'inclinaison de ladite rondelle (7) dans un état dans lequel ledit corps assemblé (40) est dans ladite posture d'assemblage ; et

    g) déterminer que ledit corps assemblé (40) est un produit défectueux lorsque ladite quantité d'inclinaison dépasse une valeur de seuil prédéterminée.


     
    13. Procédé pour fabriquer ledit capteur de gaz selon la revendication 12, dans lequel :
    à ladite étape f), une valeur de différence entre une valeur maximum et une valeur minimum dans les valeurs des hauteurs dans quatre points de ladite rondelle (7) faisant un angle de 90 degrés entre eux dans une direction circonférentielle, est obtenue en tant que dite quantité d'inclinaison.
     
    14. Procédé pour fabriquer ledit capteur de gaz selon la revendication 13,
    ladite étape f) comprenant les étapes consistant à :

    f-1) mesurer les positions de hauteur de deux points opposés entre eux avec ledit élément de capteur (10) entre eux, dans lesdits quatre points par deux éléments de mesure de hauteur (162p) à la fois ; et

    f-2) mesurer les positions de hauteur de deux points résiduels qui n'ont pas été mesurés à ladite étape f-1) dans lesdits quatre points par lesdits deux éléments de mesure de hauteur (162p) à la fois, et
    ladite quantité d'inclinaison est calculée sur la base d'un résultat de mesure à ladite étape f-1) et ladite étape f-2) .


     
    15. Procédé pour fabriquer ledit capteur de gaz selon l'une quelconque des revendications 6 à 14,
    ledit élément de capteur (10) comprend un dispositif de chauffage (70) composé d'un dispositif de chauffage à résistance dans ce dernier,
    une pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) étant électriquement raccordées audit dispositif de chauffage (70) dans ledit autre côté d'extrémité, et
    le procédé comprenant en outre les étapes consistant à :

    h) mesurer une valeur de résistance dudit dispositif de chauffage via ladite pluralité de bornes d'électrode de dispositif de chauffage dudit élément de capteur inclus dans ledit corps assemblé ; et

    i) déterminer que ledit corps assemblé est un produit défectueux lorsque ladite valeur de résistance dudit dispositif de chauffage obtenue à ladite étape h) dépasse une valeur de seuil prédéterminée.


     
    16. Procédé pour fabriquer ledit capteur de gaz selon la revendication 15, dans lequel :

    ladite pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) est prévue uniquement dans l'une des deux surfaces principales opposées entre elles dudit élément de capteur (10), et

    à ladite étape h), alors que des broches de sonde (163p) pour la mesure viennent en butée contre une pluralité de bornes d'électrode qui peut correspondre à ladite pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) incluses dans chacune desdites deux surfaces principales avec ledit corps assemblé qui est dans ladite posture d'assemblage, ladite valeur de résistance dudit dispositif de chauffage (70) est mesurée via des bornes d'électrode qui correspondent vraiment à ladite pluralité de bornes d'électrode de dispositif de chauffage dans ladite pluralité de bornes d'électrode.


     
    17. Procédé pour fabriquer ledit capteur de gaz selon la revendication 16, dans lequel :

    ladite pluralité de bornes d'électrode de dispositif de chauffage sont trois bornes d'électrode, et

    à ladite étape h), trois broches de sonde (163p) pour la mesure, dont les parties d'extrémité ne sont pas positionnées sur une ligne droite identique, sont préparées pour chaque côté desdites deux surfaces principales, et chacune desdites trois broches de sonde pour la mesure viennent en butée contre chacune parmi lesdites trois bornes d'électrode qui peuvent correspondre à ladite pluralité de bornes d'électrode de dispositif de chauffage de chaque côté desdites deux surfaces principales.


     
    18. Appareil de fabrication de capteur de gaz, ledit appareil comprenant au moins un élément pour obtenir un corps assemblé (40) constituant ledit capteur de gaz en réalisant un traitement prédéterminé sur un corps semi-assemblé (40α) qui est fabriqué à l'avance, et ledit corps semi-assemblé (40α) comprenant :

    un ensemble monté annulaire dans lequel une pluralité d'éléments montés de manière annulaire (7, 8, 9), dont au moins l'un est un comprimé de poudre en céramique (9), chacun ayant une forme de disque ou une forme cylindrique, sont montés de manière annulaire sur un élément de capteur (10) avec une forme de plaque allongée, qui est réalisé à partir d'une céramique ; et

    un corps tubulaire (30) qui est monté de manière annulaire sur une périphérie externe desdits éléments montés de manière annulaire (7, 8, 9) et pouvant mettre en prise un côté d'extrémité desdits éléments montés de manière annulaire dans ce dernier, et

    ledit élément pour obtenir ledit corps assemblé comprenant :

    un élément de positionnement (132) venant en butée contre une extrémité dudit élément de capteur (10) constituant ledit corps semi-assemblé (40α) pour positionner ledit élément de capteur (10) ;

    un premier élément de compression (134) appliquant une première force sur lesdits éléments montés de manière annulaire (7, 8, 9) depuis l'autre côté d'extrémité dudit élément de capteur (10) qui a été positionné par ledit élément de positionnement (132) et réalisant ainsi une première compression pour compresser ledit comprimé de poudre (9) ; et

    un élément de contrainte (133) pouvant contraindre ledit élément de capteur (10) dans une région de contrainte (133e) prédéterminée dans ledit autre côté d'extrémité dudit élément de capteur (10), dans lequel :
    ledit premier élément de compression (134) réalise ladite première compression dans un état dans lequel ledit élément de contrainte (133) contraint ledit élément de capteur (10) dans ladite région de contrainte (133e) dans ledit autre côté d'extrémité dudit élément de capteur (10), pour fixer ensuite ledit élément de capteur (10) à l'intérieur dudit corps tubulaire (30).


     
    19. Appareil de fabrication de capteur de gaz selon la revendication 18, dans lequel :
    ledit élément de contrainte (133) est une paire de gabarits de contrainte, et chacun de ladite paire de gabarits de contrainte est disposé à une distance prédéterminée de l'autre dans une direction d'extension dudit élément de capteur (10) au moment de la formation de ladite région de contrainte (133e).
     
    20. Appareil de fabrication de capteur de gaz selon la revendication 18 ou 19, dans lequel :

    ladite pluralité d'éléments montés de manière annulaire (7, 8, 9) comprend une pluralité d'isolants en céramique (8), et

    ladite région de contrainte (133e) est formée de sorte qu'un jeu entre ledit élément de contrainte (133) et ledit élément de capteur (10) est égal ou inférieur à une valeur maximum d'un espace entre l'un de ladite pluralité d'isolants (8) qui est le plus proche de ladite région de contrainte (133e) dans ladite pluralité d'isolants (8), et ledit élément de capteur (10).


     
    21. Appareil de fabrication de capteur de gaz selon l'une quelconque des revendications 18 à 20,
    ledit premier élément de compression (134) comprenant :
    un premier gabarit de compression venant en butée contre lesdits éléments montés de manière annulaire (7, 8, 9) depuis ledit autre côté d'extrémité dudit élément de capteur (10) pour appliquer ladite première force, dans lequel :
    ledit premier gabarit de compression vient en butée contre lesdits éléments montés de manière annulaire, appliquant ainsi ladite première force, tout en y logeant ledit élément de contrainte (133) formant ladite région de contrainte (133e).
     
    22. Appareil de fabrication de capteur de gaz selon l'une quelconque des revendications 18 à 21,
    ledit élément pour obtenir ledit corps assemblé (40) comprenant en outre :
    un second élément de compression appliquant, après ladite première compression, une seconde force qui est supérieure à ladite première force sur lesdits éléments montés de manière annulaire (7, 8, 9) depuis ledit autre côté d'extrémité dudit élément de capteur (10) avec ladite une extrémité dudit élément de capteur qui ne vient pas en butée contre ledit élément de positionnement (132) et réalisant ainsi une seconde compression pour compresser davantage ledit comprimé de poudre (9), pour réaliser un scellement hermétique entre les espaces situés sur un côté d'extrémité et ledit autre côté d'extrémité dudit élément de capteur est réalisé à l'intérieur dudit corps tubulaire (30).
     
    23. Appareil de fabrication de capteur de gaz selon la revendication 22, dans lequel :

    une posture de chacun parmi ledit corps intermédiaire et ledit corps assemblé dans lequel une direction longitudinale dudit élément de capteur (10) s'étend dans une direction verticale et ledit autre côté d'extrémité est positionné dans un côté supérieur, est définie comme étant une posture d'assemblage de chacun parmi ledit corps semi-assemblé (40α) et ledit corps assemblé (40),

    ledit élément de positionnement (132) vient en butée contre ladite une extrémité dudit élément de capteur (10) depuis un côté inférieur dudit élément de capteur avec ledit corps semi-assemblé (40α) qui est dans ladite posture d'assemblage,

    dans ladite première compression, ladite première force est appliquée sur une partie supérieure desdits éléments montés de manière annulaire (7, 8, 9) sous la forme d'une force verticalement descendante dans un état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage et ledit élément de capteur (10) a été positionné avec ledit élément de positionnement (132), de sorte que ledit comprimé de poudre (9) est compressé, et ledit élément de capteur (10) est fixé dans une première position dépendant d'une position dudit élément de positionnement (132) par ledit comprimé de poudre compressé, et

    dans ladite seconde compression, ladite seconde force est appliquée sur ladite partie supérieure desdits éléments montés de manière annulaire (7, 8, 9) dans ledit état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage.


     
    24. Appareil de fabrication de capteur de gaz selon la revendication 23, dans lequel :

    ledit élément de capteur (10) est déplacé de ladite première position à une seconde position dans une direction verticale par le biais de ladite seconde compression, et

    ledit élément de positionnement (132) est disposé de sorte que ladite seconde position est située dans une plage qui est déterminée à l'avance comme étant une position dudit élément de capteur (10) dans ledit corps assemblé (40).


     
    25. Appareil de fabrication de capteur de gaz selon la revendication 24, dans lequel :
    ledit élément de positionnement (132) est disposé de sorte que ladite seconde position est située dans ladite plage qui est déterminée sur la base d'une corrélation entre ladite première position et ladite seconde position dudit élément de capteur (10), ladite corrélation étant spécifiée à l'avance.
     
    26. Appareil de fabrication de capteur de gaz selon l'une quelconque des revendications 22 à 25,
    ledit élément pour obtenir ledit corps assemblé comprenant en outre :
    un premier élément d'emboutissage (143) réalisant un premier emboutissage pour emboutir ledit corps tubulaire (30) dans ledit état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage, à partir de sa périphérie externe, dans une première position d'emboutissage qui est positionnée juste au-dessus de la partie la plus haute desdits éléments montés de manière annulaire (7, 8, 9) dont le comprimé de poudre (9) a été compressé par ladite seconde compression.
     
    27. Appareil de fabrication de capteur de gaz selon la revendication 26, dans lequel :
    ledit premier élément de compression réalise ledit premier emboutissage avec ledit second élément de compression conservé pour appliquer ladite seconde force sur ladite partie supérieure desdits éléments montés de manière annulaire (7, 8, 9).
     
    28. Appareil de fabrication de capteur de gaz selon la revendication 26 ou 27,
    ledit élément pour obtenir ledit corps assemblé comprenant en outre :
    un second élément d'emboutissage (153) réalisant un second emboutissage pour emboutir ledit corps tubulaire (30), dans ledit état dans lequel ledit corps semi-assemblé (40α) est dans ladite posture d'assemblage, à partir de sa périphérie externe, dans une seconde position d'emboutissage qui est positionnée dans une position latérale dudit comprimé de poudre (9) après ledit premier emboutissage.
     
    29. Appareil de fabrication de capteur de gaz selon l'une quelconque des revendications 23 à 28,
    lesdits éléments montés de manière annulaire comprenant une rondelle (7), et
    l'appareil de fabrication de capteur de gaz comprenant en outre :

    un élément de calcul de quantité d'inclinaison pour obtenir une quantité d'inclinaison de ladite rondelle dans un état dans lequel ledit corps assemblé est dans ladite posture d'assemblage ; et

    un élément de détermination d'inclinaison pour déterminer que ledit corps assemblé est un produit défectueux lorsque ladite quantité d'inclinaison dépasse une valeur de seuil prédéterminée.


     
    30. Appareil de fabrication de capteur de gaz selon la revendication 29, dans lequel :
    ledit élément de calcul de quantité d'inclinaison obtient une valeur de différence entre une valeur maximum et une valeur minimum dans les valeurs des hauteurs dans quatre points dans ladite rondelle faisant un angle à 90 degrés entre eux dans une direction circonférentielle en tant que dite quantité d'inclinaison.
     
    31. Appareil de fabrication de capteur de gaz selon la revendication 30, dans lequel :
    ledit élément de calcul de quantité d'inclinaison est configuré pour réaliser :

    une première mesure pour mesurer les positions de hauteur de deux points opposés entre eux avec ledit élément de capteur entre eux, dans lesdits quatre points par deux éléments de mesure de hauteur à la fois, et

    une seconde mesure pour mesurer les positions de hauteur des deux points résiduels qui n'ont pas été mesurés dans ladite première mesure dans lesdits quatre points par lesdits deux éléments de mesure de hauteur à la fois,

    calculant ainsi ladite quantité d'inclinaison sur la base d'un résultat de mesure dans ladite première mesure et ladite seconde mesure.


     
    32. Appareil de fabrication de capteur de gaz selon l'une quelconque des revendications 23 à 31,
    ledit élément de capteur comprenant un dispositif de chauffage (70) composé par un dispositif de chauffage à résistance à l'intérieur de ce dernier, et
    une pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) qui sont électriquement raccordées audit dispositif de chauffage (70) dans ledit autre côté d'extrémité,
    l'appareil de fabrication de capteur de gaz comprenant en outre :

    un élément de mesure de résistance mesurant une valeur de résistance dudit dispositif de chauffage (70) via ladite pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) dudit élément de capteur (10) incluse dans ledit corps assemblé (40) ; et

    un élément de détermination de continuité déterminant que ledit corps assemblé est un produit défectueux lorsque ladite valeur de résistance dudit dispositif de chauffage (70) obtenue dans ledit élément de mesure de résistance dépasse une valeur de seuil prédéterminée.


     
    33. Appareil de fabrication de capteur de gaz selon la revendication 32, dans lequel :

    ladite pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) sont prévues uniquement dans l'une des deux surfaces principales opposées entre elles dudit élément de capteur (10), et

    ledit élément de mesure de résistance réalise des broches de sonde (163p) pour la mesure en butée contre une pluralité de bornes d'électrode qui peut correspondre à ladite pluralité de bornes d'électrode de dispositif de chauffage (13f, 13g) incluse dans chacune desdites deux surfaces principales avec ledit corps assemblé qui est dans ladite posture d'assemblage, et mesure ladite valeur de résistance dudit dispositif de chauffage (70) via des bornes d'électrode qui correspondent vraiment à ladite pluralité de bornes d'électrode de dispositif de chauffage dans ladite pluralité de bornes d'électrode.


     
    34. Appareil de fabrication de capteur de gaz selon la revendication 33, dans lequel :

    ladite pluralité de bornes d'électrode de dispositif de chauffage sont trois bornes d'électrode, et

    ledit élément de mesure de résistance comprend trois broches de sonde (163p) pour la mesure, dont les parties d'extrémité ne sont pas positionnées dans une ligne droite identique, pour chaque côté desdites deux surfaces principales, et amène chacune desdites trois broches de sonde pour la mesure, à venir en butée contre chacune desdites trois bornes d'électrode qui peuvent correspondre à la pluralité de bornes d'électrode de dispositif de chauffage de chaque côté desdites deux surfaces principales.


     
    35. Appareil de fabrication de capteur de gaz selon l'une quelconque des revendications 18 à 34, comprenant en outre :

    un premier mécanisme de montage annulaire pour monter de manière annulaire ladite pluralité d'éléments montés de manière annulaire sur ledit élément de capteur (10) afin d'obtenir ledit ensemble monté de manière annulaire ; et

    un second mécanisme de montage annulaire pour monter de manière annulaire ledit corps tubulaire (30) sur ladite périphérie externe dudit ensemble monté de manière annulaire afin d'obtenir ledit corps semi-assemblé (40α).


     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description