Weft monitoring method and weft monitoring device for fluid jet loom

Abstract

 A weft monitoring method for a fluid jet loom is provided. The fluid jet loom includes a weft insertion device (60) including a plurality of weft supply systems (L), each weft supply system (L) including a weft supply package (1), a weft measuring-and-storing device (4), and a weft insertion nozzle (5). The weft insertion device (60) performs weft insertions by successively using the weft supply systems (L) in turn in accordance with a preset weft insertion pattern. The weft insertion device (60) is such that, when a supply weft breakage occurs in any of the weft supply systems (L), the weft insertion device (60) excludes the weft supply system (L) in which the supply weft breakage has occurred and continues the weft insertion using only the other weft supply system (L) or the other weft supply systems (L). In the fluid jet loom, sensors that detect movements of wefts are provided, each sensor being provided at a location between the weft supply package (1) and the weft measuring-and-storing device (4) in the corresponding weft supply system (L). The weft monitoring method includes the step of outputting a loom stop signal when the sensor detects the movement of the weft in the weft supply system (L) in which the supply weft breakage has occurred.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a weft monitoring method and a weft monitoring device for monitoring a weft in a fluid jet loom including a weft insertion device including a plurality of weft supply systems.

2. Description of the Related Art

[0002] As disclosed in Japanese Unexamined Patent Application Publication No. 2008-19515 (Patent Literature 1 (PTL 1)), a fluid jet loom is provided with a weft insertion device including a plurality of weft supply systems each including a weft supply package, a weft measuring-and-storing device, and a nozzle. In the weft insertion device, weft insertions are performed by successively using the weft supply systems in turn in accordance with a preset weft insertion pattern. In addition, in the weft insertion device, if yarn breakage (supply weft breakage) occurs in any one of the weft supply systems at a location that is upstream from the weft measuring-and-storing device in a weft draw-out direction (hereunder simply referred to as "upstream side"), the weft supply system in which the supply weft breakage has occurred is excluded and the weft insertion is continued using only the remaining weft supply systems.

[0003] Similarly, Japanese Unexamined Patent Application Publication No. 5-9838 (Patent Literature 2 (PTL 2)) discloses performance and continuation of weft insertion using a method that is similar to that disclosed in PTL 1, with a plurality of channels (weft supply systems) each including a weft supply package, a storage drum (weft measuring-and-storing device), and a main nozzle (weft insertion nozzle) being provided.

[0004] In such weft insertion devices disclosed in PTL 1 and PTL 2, even if, during weaving, a supply weft breakage occurs in any one of the plurality of weft supply systems, the loom is not stopped, and the weaving is continued by weft insertion using the remaining weft supply systems that insert wefts of the same type. Therefore, the above-described weft insertion devices are capable of increasing operation rate of a loom by reducing the number of stoppages of the loom. Incidentally, the weft insertion devices disclosed in PTL 1 and PTL 2 refer not only to those in which insertion of one type of weft is performed by all of the weft supply systems, but also to those in which a plurality of weft supply systems are used to insert at least one type of weft among a plurality of types of wefts.

[0005] In the weft insertion devices disclosed in PTL 1 and PTL 2, even if a supply weft breakage occurs in any one of the weft supply systems as mentioned above, the loom is not stopped, and weft insertion is continued by the remaining weft supply systems. Therefore, a weft extending from a weft supply package in a weft supply system in which a supply weft breakage has occurred is transported while it becomes entangled with a weft of another weft supply system that continues weft insertion, as a result of which the weft of the weft supply system in which the supply weft breakage has occurred may be inserted along with the weft of the other weft supply system.

[0006] More specifically, in the weft supply system in which the supply weft breakage has occurred, an end of a weft CC extending from the weft supply package (hereunder referred to as "cut weft") is a free end, and, for example, hangs down from, for example, a weft guide member (including a weft supply sensor) that is provided downstream from the weft supply package in the weft draw-out direction (hereunder simply referred to as "downstream side"). (See Fig. 1.)

[0007] Therefore, the end of the cut weft that hangs down may contact a portion of the weft disposed between the weft measuring-and-storing device and the weft supply package of the other weft supply system that continues weft insertion, and may become entangled with this portion of the weft (the wefts become entangled or fluffs of the wefts become entangled and, thus, the wefts stick to each other).

[0008] In this case, when the cut weft that is entangled with the weft of the other weft supply system is transported as the aforementioned portion of the weft moves forward as the other weft supply system performs the weft insertion, the winding of the weft around the weft measuring-and-storing device and the weft insertion are performed with the two wefts being entangled. In addition, when the cut weft is inserted along with the weft of the other weft supply system as described above, the weft insertion is performed in a state that differs from a proper state. Therefore, defective quality of a fabric results.

[0009] If only the case shown in Fig. 1 is assumed, when a supply weft breakage occurs in the bottommost weft supply system among the plurality of weft supply systems, it may seem that the above-described problems do not occur. However, even here, the above-described problems may occur. For example, when the plurality of weft supply systems are disposed side by side, all of the weft supply systems are the bottommost weft supply systems. When a supply weft breakage occurs in any one of the weft supply systems in this case, air current that is generated at the loom and air current in a weaving mill may cause a cut weft extending from the weft supply package of the weft supply system in which the supply weft breakage has occurred to be transported as the weft of the neighboring weft supply system is inserted.

SUMMARY OF THE INVENTION

[0010] Accordingly, in view of the above-described situation, it is an object of the present invention to, when a supply weft breakage occurs in any one of weft supply systems in a fluid jet loom including a weft insertion device similar to that disclosed in either PTL 1 or PTL 2 and when a cut weft extending from a weft supply package of the weft supply system in which the supply weft breakage has occurred becomes entangled with a weft of another weft supply system and is transported, detect the transport of the weft to overcome problems such as those mentioned above.

[0011] The present invention presupposes a fluid jet loom including a weft insertion device including a plurality of weft supply systems, each weft supply system including a weft supply package, a weft measuring-and-storing device, and a weft insertion nozzle. The weft insertion device performs weft insertions by successively using the weft supply systems in turn in accordance with a preset weft insertion pattern. The weft insertion device is such that, when a supply weft breakage occurs in any of the weft supply systems, the weft insertion device excludes the weft supply system in which the supply weft breakage has occurred and continues the weft insertion using only the other weft supply system or the other weft supply systems. However, as in the aforementioned PTL 1 and PTL 2, the weft insertion device for the fluid jet loom presupposed by the present invention is such that the weft insertion device includes not only that in which insertion of one type of weft is performed by all of the weft supply systems, but also that in which a plurality of types of wefts are inserted and a plurality of weft supply systems are used to insert at least one type of weft among the plurality of types of wefts.

[0012] A weft monitoring method for the fluid jet loom according to the present invention is provided. In the fluid jet loom, sensors that detect movements of wefts are provided, each sensor being provided at a location between the weft supply package and the weft measuring-and-storing device in the corresponding weft supply system. The weft monitoring method includes the step of outputting a loom stop signal when the sensor detects the movement of the weft in the weft supply system in which the supply weft breakage has occurred.

[0013] A weft monitoring device for the fluid jet loom according to the present invention corresponding to such a weft monitoring method includes sensors that detect movements of wefts, each sensor being provided at a location between the weft supply package and the weft measuring-and-storing device in the corresponding weft supply system; and a monitoring unit that outputs a loom stop signal when the sensor has detected the movement of the weft under the condition that the supply weft breakage is occurring in the weft supply system in which the sensor is included.

[0014] According to the weft monitoring method and the weft monitoring device of the present invention, each sensor may be a weft supply sensor for detecting the supply weft breakage during weaving, each weft supply sensor being included in the corresponding weft supply system.

[0015] According to the present invention, in the weft supply system in which the supply weft breakage has occurred, it is possible to stop the loom in accordance with a loom stop signal that is output when the drawing out of the weft from the weft supply package is detected. Therefore, it is possible to prevent defective quality of a fabric to be woven.

[0016] If the weft supply sensor that is previously provided in each weft supply system is also used as a monitoring sensor (that is, a sensor that detects the transport of a weft), the device can be simplified.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 

Fig. 1 is a schematic view of a weft insertion device including a weft monitoring device according to an embodiment of the present invention.

Fig. 2 is a control block diagram of the weft insertion device including the weft monitoring device according to the embodiment.

Fig. 3 illustrates an input screen and a display screen of a setting unit in the weft insertion device including the weft monitoring device according to the embodiment.

Fig. 4 is a time chart showing, for example, a detection function of each weft supply sensor in the weft monitoring device according to the embodiment.

Fig. 5 is a time chart showing a supply weft breakage detection function of the weft insertion device.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] Fig. 1 is a schematic view of an example in which a basic structure of a weft insertion device 60 that is used in an air jet loom, serving as an exemplary fluid jet loom to which the present invention is applied, is made specific from the structural viewpoint. The weft insertion device 60 according to the embodiment is a multi-color weft insertion device that is capable of inserting a plurality of different types of wefts C in accordance with a preset weft insertion pattern. More specifically, the weft insertion device 60 according to the embodiment is a six-color weft insertion device including six weft supply systems (L1 to L6) serving as a plurality of weft supply systems L. However, since Fig. 1 is a side view of the weft insertion device 60, and three of the six weft supply systems L1 to L6 are disposed at the near side and the other three are disposed at the far side, Fig. 1 shows only the three weft supply systems L1 to L3 at the near side. In the weft insertion device 60, a plurality of weft supply systems L are grouped; and, in the weft supply systems L in the same group, wefts C of the same type are set, and the weft supply systems L in the group successively perform weft insertions in turn. Accordingly, a group of weft supply systems L that insert wefts C of the same type is hereunder called a "weft insertion group".

[0019] Each weft supply system L includes a weft supply package 1, a weft guide 2, a weft measuring-and-storing device 4, a weft supply sensor 3, and a weft insertion nozzle 5. Each weft supply package 1 is mounted to a weft supply peg (not shown). Each weft guide 2 guides a weft (weft C) that is released from the corresponding weft supply package 1 to a predetermined location at the downstream side of the corresponding weft supply package 1. Each weft measuring-and-storing device 4 is provided at the downstream side of the corresponding weft guide 2. Each weft supply sensor 3 is disposed between its corresponding weft guide 2 and its corresponding weft measuring-and-storing device 4. Each weft insertion nozzle 5 is disposed at the downstream side of its corresponding weft measuring-and-storing device 4. In the illustrated embodiment, each weft insertion nozzle 5 includes an auxiliary main nozzle 5a and a main nozzle 5b. Each auxiliary main nozzle 5a is disposed at the downstream side of its corresponding weft measuring-and-storing device 4. Each main nozzle 5b is disposed at the downstream side of its corresponding auxiliary main nozzle 5a. Of the nozzles 5a and 5b, an end of the main nozzle 5b is provided so as to oppose a warp shed S.

[0020] Each weft measuring-and-storing device 4 includes a storage drum 41, a rotary yarn guide 42, a feeder motor 43, and a stopper pin 44. Each weft C having a length that is supplied in one weft insertion is wound upon its corresponding storage drum 41. Each rotary yarn guide 42 has the shape of a pipe, receives the weft C from its corresponding weft supply package 1, and is disposed at the upstream side of its corresponding storage drum 41. A downstream-side end portion of each rotary yarn guide 42 faces an outer peripheral surface of its corresponding storage drum 41. Each feeder motor 43 drives its corresponding rotary yarn guide 42. Each stopper pin 44 is disposed at the downstream side of its corresponding storage drum 41. Each stopper pin 44 allows the weft C wound upon the outer peripheral surface of its corresponding storage drum 41 to be releasable and unreleasable by advancing and retreating from its corresponding storage drum 41 as a result of being driven by a solenoid. Although not shown in Fig. 1, each weft measuring-and-storing device 4 includes a pushbutton 6 serving as restoring means that restores a weft supply system L that has been excluded from a weft insertion pattern (hereunder may be referred to as an "excluded weft supply system") to the weft insertion pattern by a manual operation (see Fig. 2).

[0021] Fig. 2 shows, in a control block diagram, an example in which a basic structure of the weft insertion device 60 according to the embodiment is made specific from the viewpoint of control. A weft insertion controlling device 11 of the weft insertion device 60 includes a weft insertion control circuit 12, a setting unit 13, and a weft insertion pattern setting unit 14. The setting unit 13 includes an input screen 13a, a display screen 13b, and a computing circuit 13c. Since, as mentioned above, the weft supply systems L are successively used in turn in each weft insertion group, the setting unit 13 is used for setting which weft supply system L is to belong to which weft insertion group in accordance with each weft C that is set.

[0022] Fig. 3 illustrates the input screen 13a and the display screen 13b of the setting unit 13 for setting which weft supply system L is to belong to which weft insertion group. The input screen 13a and the display screen 13b are provided at the same screen of an operation-condition input/display liquid crystal panel that is set at an operating panel.

[0023] The input screen 13a is provided with a "weft supply system no." section 13aa serving as a selecting section for selecting individual weft supply systems L. By touching a circular area including a corresponding number in the "weft supply system no." section 13aa, the weft supply system L of the corresponding number is selected. The input screen 13a is also provided with circles that indicate the identifying colors of the corresponding wefts C on the left of "weft C" sections of the input screen 13a, that is, on the left of a "first weft C1" section, a "second weft C2" section, a "third weft C3" section, a "fourth weft C4" section, a "fifth weft C5" section, and a "sixth weft C6" section. Regarding the circles beside the corresponding weft sections, different colors are used as identifying colors. However, for convenience, the different colors are represent by patterns in the circles.

[0024] The display screen 13b includes six circular areas in which numbers from 1 to 6 are indicated. Each circular area is displayed on the display screen 13b in correspondence with the weft supply system L of the corresponding number so that the circular area no. 1 corresponds to the first weft supply system L1, the circular area no. 2 corresponds to the second weft supply system L2, etc. Each circular area illuminates with a color corresponding to the identifying color of the weft C that is set at the corresponding weft supply system L. This allows an operator to know by color perception which type of weft C is set at the weft supply system L of the corresponding number.

[0025] On the basis of a fabric specification, considering, for example, the frequency with which weft insertion is performed and physical properties of the wefts C, the number of weft supply systems L that are used with each weft C and which wefts C are to be set at which weft supply systems L are previously determined, so that the weft supply packages 1 for each weft C type are set at the determined number of weft supply systems. For example, in the embodiment, the specification of a fabric to be woven is such that weaving is performed by using three types of wefts (that is, the first weft C1, the second weft C2, and the third weft C3) and by performing weft insertions in accordance with a weft insertion pattern in which weft insertion in the order C1 => C2 => C3 is defined as one cycle. In the weft insertion pattern, the frequency with which each weft C is inserted is the same. In the embodiment, two weft supply systems L are provided for setting the first weft C1, two weft supply systems L are provided for setting the second weft C2, and two weft supply systems L are provided for setting the third weft C3. In addition, it is determined which weft C is to be inserted by which weft supply system L, that is, it is determined which weft C is to correspond to which weft supply system L. On the basis of this, two weft supply packages 1 for each weft C type are set at the corresponding number of weft supply systems by an operator. As a result, in the embodiment, the first weft C1 is set at the first weft supply system L1 and the second weft supply system L2, the second weft C2 is set at the third weft supply system L3 and the fourth weft supply system L4, and the third weft C3 is set at the fifth weft supply system L5 and the sixth weft supply system L6.

[0026] Then, when each weft C type is set at the corresponding weft supply systems L in the weft insertion device 60 as mentioned above, on the basis of this, the setting unit 13 sets the weft insertion controlling device 11 so that the weft supply systems L at which the same type of weft C is set are set in one weft insertion group. That is, as a result of setting each type of weft C at the corresponding weft supply systems L as mentioned above, the first weft supply system L1 and the second weft supply system L2 at which the first weft C1 is set are set in one weft insertion group including two weft supply systems L and inserting the first weft C1. Similarly, the third weft supply system L3 and the fourth weft supply system L4 at which the second weft C2 is set are set in one weft insertion group that inserts the second weft C2. Further, the fifth weft supply system L5 and the sixth weft supply system L6 at which the third weft C3 is set are set in one weft insertion group that inserts the third weft C3.

[0027] More specifically, the setting of the weft insertion groups with respect to the weft insertion controlling device 11 is carried out from the input screen 13a in accordance with 1) to 3) below.

[0028] 1) First, an operator touches a "setting start" section 13ad at the "first weft" section at the input screen 13a. This makes it possible to set the first weft C1, that is, the weft supply systems L that perform weft insertions when the first weft C1 of the weft insertion pattern is selected. Next, after touching and selecting the circular area including the number 1 in the "weft supply system no." section 13aa, the operator touches an "include" section 13ab. This sets the first weft supply system L1 as a weft supply system L that performs weft insertion when the first weft C1 is selected, and causes the circular area including the number 1 at the display screen 13b to change color to the identifying color of the first weft C1. Similarly, after touching the circular area including the number 2 in the "weft supply system no." section 13aa, the operator touches the "include" section 13ab. This sets the second weft supply system L2 as a weft supply system L that performs weft insertion when the first weft C1 is selected, and causes the circular area including the number 2 at the display screen 13b to illuminate with the same color as that of the circular area including the number 1.

[0029] In this state, a confirmation is made that the circular areas including the other numbers are not illuminated with the identifying color of the first weft C1. For example, if a circular area including any of the other numbers illuminates with the identifying color of the first weft C1, that is, if, by, for example, an erroneous operation, a weft supply system L that was not intended to be selected is set so as to perform weft insertion when the first weft C1 is selected and the circular area including the number corresponding to the number of this weft supply system L illuminates with the identifying color of the first weft C1, the following is performed. That is, in order to correct this, after touching and selecting the circular area including this number at the "weft supply system no." section 13aa, the operator touches a "delete" section 13ac. This cancels the incorrect setting, and causes the circular area including this number to be turned off at the display screen 13b.

[0030] 2) After the setting operation, the operator touches a "setting completed" section 13ae at the "first weft" section. This determines the setting of the first weft supply system L1 and the second weft supply system L2 as the weft supply systems L that perform weft insertions when the first weft C1 is selected. That is, the first weft supply system L1 and the second weft supply system L2 are set in a weft insertion group in which the first weft supply system L1 and the second weft supply system L2 successively perform weft insertions in turn in accordance with when the first weft C1 of the weft insertion pattern is selected.

[0031] 3) Even at the "second weft" section and the "third weft" section at the input screen 13a, the same operations that are performed at the "first weft" section are performed. This causes the third weft supply system L3 and the fourth weft supply system L4 to be set in a weft insertion group in which the third weft supply system L3 and the fourth weft supply system L4 successively perform weft insertions in turn in accordance with when the second weft C2 of the weft insertion pattern is selected. In addition, this causes the fifth weft supply system L5 and the sixth weft supply system L6 to be set in a weft insertion group in which the fifth weft supply system L5 and the sixth weft supply system L6 successively perform weft insertions in turn in accordance with when the third weft C3 of the weft insertion pattern is selected. Although selection is made for every weft supply system L to set each weft supply system L in accordance with its corresponding weft C type, a part of a previous weaving condition matches the current weaving condition, so that a weft supply system L that is already set to the corresponding weft C type may be such that a selection operation and an inclusion operation of a weft supply system L is omitted.

[0032] The operation of the weft insertion device 60 in which the weft insertion groups are set in this way is hereunder described on the basis of Fig. 2.

[0033] At the setting unit 13, the weft supply systems L that are selected with each weft C type at the input section 13a are set in weft insertion groups with each weft C type at the computing circuit 13c. The computing circuit 13c causes the circular areas at the display screen 13b to illuminate with different identifying colors with each weft C type that is set at its corresponding weft supply systems L.

[0034] On the basis of information of a weft insertion operation mode that is input from the computing circuit 13c, the weft insertion control circuit 12 determines the order of the weft supply systems L that successively perform weft insertions in turn, in accordance with the weft insertion groups for the corresponding weft C types. In the embodiment, the weft insertion control circuit 21 determines the order of use of the weft supply systems L that are successively used in turn for the insertions of the first weft C1 to the third weft C3 as follows. For the insertion of the first weft C1, the order is L1 → L2, that is, the first weft supply system L1 → the second supply system L2 → the first weft supply system L1 → the second weft supply system L2. For the insertion of the second weft C2, similarly to the order for the insertion of the first weft C1, the order is the third weft supply system L3 → the fourth weft supply system L4. For the insertion of the third weft C3, similarly to the order for the insertion of the first weft C1, the order is the fifth weft supply system L5 → the sixth weft supply system L6.

[0035] The weft insertion control circuit 12 is connected to the weft insertion pattern setting unit 14, and includes a storage unit (not shown) that stores weft insertion pattern information that has been input from the weft insertion pattern setting unit 14. The pushbuttons 6, the weft supply sensors 3, the feeder motors 43, the solenoids of the stopper pins 44, and electromagnetic on-off valves (which continually supply air from a pressure air source (not shown) to the corresponding auxiliary main nozzles 5a and the corresponding main nozzles 5b) of the corresponding weft supply systems L are connected to the weft insertion control circuit 12.

[0036] When the operation of a loom is started, with each loom cycle (with each rotation of a main shaft of the loom), the weft insertion control circuit 12 reads out the weft C type that is to be inserted next from the stored weft insertion pattern information, and, on the basis of the order of use of the weft supply systems L that successively insert the wefts C in turn, the weft supply systems L that perform the weft insertions are determined. On the basis of information of the rotational angle of the main shaft of the loom from an encoder EN connected to a main motor M that drives the main shaft of the loom (not shown), the weft insertion control circuit 21 drives at a predetermined time the electromagnetic on-off valves of the weft supply systems that perform the weft insertions, and causes the electromagnetic on-off valves to start and end air jetting from the auxiliary main nozzles 5a and the main nozzles 5b.

[0037] When, in any one of the weft supply systems L, a supply weft breakage occurs, the weft insertion control circuit 12 determines that a supply weft breakage has occurred in this weft supply system L on the basis of a yarn detection signal from the weft supply sensor 3. Then, the weft insertion control circuit 12 excludes this weft supply system L from the weft insertion group for the weft C type that is set at this weft supply system L (that is, from the successive weft insertions that are performed in turn), so that the insertion of this weft C type is continued using the remaining weft supply system L. For example, when a supply weft breakage occurs in the first weft supply system L1 that belongs to the group that inserts the first weft C1, the subsequent insertion of the first weft C1 is continued only by the second weft supply system L2, which is the other weft supply system of the group that inserts the first weft C1.

[0038] When the weft supply system L is excluded, the weft insertion control circuit 12 outputs information of the excluded weft supply system L towards the computing circuit 13c of the setting unit 13. By this, the computing circuit 13c changes a lighting mode of the circular area including the number of the excluded weft supply system L at the display screen 13b, for example, from a continuous lighting mode to a flashing lighting mode. This allows the operator to easily know which weft supply system L is excluded.

[0039] When repairing of the weft supply system L that has been excluded from the weft insertion group in which the supply weft breakage has occurred is completed, and the operator operates the pushbutton 6, a repair completion signal is output to the weft insertion control circuit 12. On the basis of the repair completion signal, the weft insertion control circuit 12 restores the weft supply system L to a state in which it is used to successively perform the insertions of the set weft C type in turn along with the other weft insertion system L; and outputs a restoring signal, which indicates the restoration of the weft supply system L, towards the computing circuit 13c. By this, the computing circuit 13c causes the lighting mode of the circular area including the number of the excluded weft supply system L at the display screen 13b to be restored to its original lighting mode.

[0040] In the air jet loom according to the embodiment described above, the weft insertion device 60 includes a weft monitoring device according to the present invention. The weft monitoring device includes sensors and a monitoring unit 15. The sensor is provided between the weft measuring-and-storing device 4 and the weft supply package 1 of each weft supply system L, and detects the movement of a weft C. The monitoring unit 15 outputs a loom stop signal when any one of the sensors has detected movement of a weft C under the condition that yarn breakage is occurring in a weft supply system L. In the embodiment, the weft supply sensors 3 that are provided for determining a supply weft breakage during weaving are used as the sensors that detect movements of wefts C.

[0041] In the embodiment, as shown in Fig. 2, it is assumed that the monitoring unit 15 is included in the weft insertion controlling device 11. However, the monitoring unit 15 is not limited to that included in the weft insertion controlling device 11. The monitoring unit 15 may be formed independently of the weft insertion controlling device 11, or may be included in the weft insertion control circuit 12 (which functions as the monitoring unit 15) in the weft insertion controlling device 11.

[0042] As shown in Fig. 2, the monitoring unit 15 is connected to the weft insertion control circuit 12. Signals from the weft supply sensors 3 are input to the monitoring unit 15 via the weft insertion control circuit 12. As regards a yarn detection signal that is output to the monitoring unit 15 from the weft insertion control circuit 12, it is possible to determine the weft supply sensor 3 of which weft supply system L the yarn detection signal is output from. Further, an exclusion signal that is output towards the computing circuit 13c of the setting unit 13 from the weft insertion control circuit 12 when a supply weft breakage has occurred in any of the weft supply systems L is also output to the monitoring unit 15. The restoring signal that is output towards the computing circuit 13c from the weft insertion control circuit 12 when the repairing of the weft supply system L that has been excluded from the weft insertion group due to the supply weft breakage is completed and when the operator pushes the corresponding pushbutton 6 is also assumed as being output to the monitoring unit 15.

[0043] The monitoring unit 15 receives the exclusion signal and temporarily stores in a built-in memory information regarding which of the weft supply systems L1 to L6 is the weft supply system (excluded weft supply system) excluded from the weft insertion group. The monitoring unit 15 receives the restoring signal and clears the content stored in this memory.

[0044] Each weft supply sensor 3 detects the movement of the weft C and outputs a yarn detection signal. Each weft supply sensor 3 outputs a high-level yarn detection signal when the movement of the weft C is detected, and a low-level yarn detection signal when the movement of the weft C is not detected. More specifically, as shown in Fig. 1, each weft supply sensor 3 includes an annular yarn guide portion 3a that is provided towards its corresponding weft guide 2 at a location between its corresponding weft guide 2 and its corresponding weft measuring-and-storing device 4, and that receives the weft C. The weft C is inserted in its corresponding yarn guide portion 3a. However, each weft supply sensor 3 is a piezoelectric weft passage sensor (sliding sensor). Its yarn guide portion 3a is positioned slightly above a path of the weft C (determined by the weft guide 2 and a weft introducing opening 42a of the rotary yarn guide 42 of its corresponding weft measuring-and-storing device 4) so that the weft C is slightly press-contacted against the inner peripheral surface of its corresponding yarn guide portion 3a. Then, an increase in contact pressure caused by an increase in the tension of the weft C as a result of drawing out the weft C is detected via the corresponding yarn guide portion 3a, so that the movement of the weft C is detected.

[0045] Fig. 5 is a time chart showing a supply weft breakage detection function. On the basis of Fig. 5, the function of detecting supply weft breakage using any of the weft supply sensors 3 when operating a weft supply system L (that is, when a weft supply system L is not excluded from a weft insertion group) is hereunder described as reference.

[0046] A supply weft breakage primarily occurs when a weft C is being drawn out by a weft measuring-and-storing device 4 (that is, when a weft C is being moved). The weft C is drawn out as a result of rotation of the rotary yarn guide 42 of the weft measuring-and-storing device 4. Therefore, a detection period of the supply weft breakage is set on the basis of a period in which the rotary yarn guide 42 is rotationally driven. The details are as follows.

[0047] In each weft measuring-and-storing device 4, the rotary yarn guide 42 is rotationally driven by its corresponding built-in driving motor (the feeder motor 43 in Fig. 2). A pulse generator (not shown) is attached to each driving motor. Each pulse generator outputs a detection pulse signal (feeder pulse) corresponding to the rotation of the driving motor to the weft insertion control circuit 12.

[0048] In the illustrated example, the start of monitoring a supply weft breakage (starting point of the detection period) is set after a predetermined condition is attained after starting the rotational driving of a rotary yarn guide 4. More specifically, the monitoring of the supply weft breakage is started when the number of pulses of the pulse signal from the pulse generator reaches a predetermined number (three pulses in the illustrated example). The end of monitoring the supply weft breakage is the time when the rotation speed of the feeder motor 43 reaches a preset rotation speed as a result of a decrease in speed of the feeder motor 43 when the driving of the rotation yarn guide 42 by the feeder motor 43 ends.

[0049] As the rotary yarn guide 42 is rotationally driven by the feeder motor 43, the weft C is wound upon the storage drum 41 of the weft measuring-and-storing device 4, as a result of which the weft C is drawn out from the weft supply package 1. As the weft C is drawn out from the weft supply package 1 by the weft measuring-and-storing device 4, the weft C is moved between the weft supply package 1 and the weft measuring-and-storing device 4. The weft supply sensor 3 detects the movement of the weft C, and outputs a yarn detection signal towards the weft insertion control circuit 12.

[0050] When yarn breakage occurs within the detection period, the movement of the weft C is stopped. Therefore, the yarn detection signal becomes a low-level signal as indicated by a double-dotted chain line in Fig. 5, and the weft insertion control circuit 12 determines that a supply weft breakage has occurred. However, in order to prevent temporary stoppage of the movement of the weft C from being erroneously determined as a supply weft breakage, the weft insertion control circuit 12 determines that a supply weft breakage has occurred when the period in which the yarn detection signal is a low-level signal continues for a preset time or more. Therefore, when the yarn detection signal is temporarily a low-level signal as indicated by a dotted line in Fig. 5, the weft insertion control circuit 12 does not determine that a supply weft breakage has occurred.

[0051] When the weft insertion control circuit 12 determines that a supply weft breakage has occurred as mentioned above, the weft insertion control circuit 12 excludes the weft supply system L at which the supply weft breakage is determined to have occurred from the weft insertion group that inserts the weft C type that is set at this weft supply system L, and outputs the exclusion signal towards the computing circuit 13c and the monitoring unit 15.

[0052] Fig. 4 shows the function of monitoring transport of a cut weft CC. In Fig. 4, the detection period is the period in which a supply weft breakage is detected (monitored) during operation (the time at which a weft insertion system L is not excluded). The monitoring period is the period in which transport of the cut weft CC is monitored in a state in which a weft supply system in which a supply weft breakage has occurred is excluded from its weft insertion group. A weft monitoring method using the above-described weft monitoring device is hereunder described on the basis of Fig. 4.

[0053] After determining that a supply weft breakage has occurred as mentioned above, regarding the weft supply system L that has been excluded from the weft insertion group due to the supply weft breakage, the monitoring of the transport of the cut weft CC by the weft C of the other weft supply system is started. The details are as follows.

[0054] First, in the embodiment, considering the movement of the weft C, the monitoring period is started from when the feeder motor 43 of a weft measuring-and-storing device 4 is completely stopped.

[0055] As mentioned above, the monitoring unit 15 stores information regarding the excluded weft supply system among the weft supply systems L1 to L6. In the case where, for example, a certain weft supply system (here, the first weft supply system L1) is excluded from its weft insertion group, if a yarn detection signal output from the weft supply sensor 3 and input via the weft insertion control circuit 12 is a yarn detection signal from the weft supply sensor 3 included in the weft supply system L1, the monitoring unit 15 determines that the transport of the cut weft CC has occurred in the excluded weft supply system. More specifically, the excluded weft supply system is excluded from the weft insertion group that performs the insertion of the weft C type that is set at the excluded weft supply system L, and does not perform the weft insertion until it is restored to the weft insertion group. Therefore, essentially, the drawing out of the weft C from the weft supply package 1 cannot be performed. However, when the drawing out of the weft in such weft supply system is detected, that is, when the weft supply sensor 3 of this weft supply system L outputs a yarn signal for detecting the movement of the weft C, the monitoring unit 15 determines that the transport of the cut weft CC has occurred in this weft supply system L.

[0056] Accordingly, as a condition for the existence of an excluded weft supply system, the monitoring unit 15 determines that the cut weft CC has been transported in the excluded weft supply system when the weft supply sensor 3 included in the excluded weft supply system L outputs a yarn detection signal that indicates that the movement of the weft C has been detected. Then, as a result of determining the transport of the cut weft CC, the monitoring unit 15 outputs a loom stop signal (one shot) to a loom control circuit (not shown), and, as a result, the loom is stopped. As in detecting a supply weft breakage when the aforementioned weft supply system L operates (when a weft insertion system L is not excluded from its weft insertion group), when a yarn detection signal is output from the weft supply sensor 3 included in the excluded weft supply system, as illustrated, the monitoring unit 15 outputs the loom stop signal only when the output of the yarn detection signal has been continued for a preset time or more so as not to perform an erroneous determination due to a temporary movement of the weft C.

[0057] In the embodiment, the weft monitoring device includes monitoring function stopping means for stopping the monitoring by the monitoring unit 15 (that is, for making ineffective (setting off) the monitoring function). In addition, in the embodiment, as shown in Fig. 2, a monitoring function stop button 13d is provided as the weft monitoring function stopping means at the setting unit 13. Incidentally, the monitoring function stop button 13d may be a button that is displayed on the touch-panel input screen 13a.

[0058] The monitoring function stop button 13d is operated when fixing a supply weft breakage of a weft supply system in which a supply weft breakage has occurred (that is, a weft supply system has been excluded from its weft insertion group). That is, when the supply weft breakage of the weft supply system L in which the supply weft breakage occurs is to be fixed, an operator, for example, draws out the weft C from the weft supply package 1. This may cause the sensor 3 to detect the movement of the weft C, and, as a result, may cause the monitoring unit 15 to make an erroneous determination that is not in accordance with the actual state (that is, to make a determination that the cut weft CC has been transported). Therefore, the aforementioned erroneous determination is prevented from occurring by stopping the monitoring by the monitoring unit 15 when fixing such a supply weft breakage.

[0059] When the operator completes the fixing of the supply weft breakage and pushes the pushbutton 6, the weft insertion control circuit 12 outputs a restoring signal for restoring the excluded weft supply system L to its original weft insertion group. This causes the excluded weft supply system L to be restored to its original weft insertion group, the stored content in the monitoring unit 15 to be cleared, and the monitoring function of the monitoring unit 15 that had been made ineffective by the operation of the monitoring function stop button 13d to be effective again. However, in this state, an excluded weft supply system under the condition for determining transport of a cut weft CC does not exist (that is, is not stored). Therefore, even if a yarn detection signal is input to the monitoring unit 15, a determination regarding the transport of the cut weft CC is not performed.

[0060] Accordingly, in the weft monitoring device according to the embodiment, a yarn detection signal from a weft supply sensor 3 that indicates that a weft C is properly being drawn out from the weft supply package 1 when a weft supply system L operates (that is, when a weft insertion system L is not excluded) is used as indicating an abnormality (transport of a cut weft CC) when this weft supply system L is excluded from its weft insertion group. On the basis of the output of the yarn detection signal, it is determined that the weft CC is transported. This makes it possible to prevent defective quality of a fabric caused when the cut weft CC becomes entangled with a weft C of another weft supply system and the cut weft CC is inserted along with the weft C of the other weft supply system. In the embodiment, each weft supply sensor 3 that is provided for detecting a supply weft breakage when the corresponding weft supply system L operates is also used as a sensor in the weft monitoring device. Therefore, it is possible to simplify the structure of each weft supply system L including the structure related to the weft monitoring device.

[0061] Although an embodiment of the present invention is described above, the present invention is not limited to the weft monitoring method and the weft monitoring device according to this embodiment. The following modifications are possible.

[0062] For example, in the embodiment, each weft supply sensor 3 used for detecting a supply weft breakage when its corresponding weft supply system L operates is also used as a sensor for monitoring a cut weft CC in an excluded weft supply system. However, instead, it is possible to use sensors that differ from the weft supply sensors 3 and that detect supply weft breakages only when weft supply systems L to which certain weft supply sensors 3 belong are excluded from their weft insertion groups. In this case, each sensor is disposed, for example, at a location between its corresponding weft supply package 1 and its corresponding weft supply sensor 3 or between its corresponding weft supply sensor 3 and its corresponding weft measuring-and-storing device 4; and the detection function of each sensor is turned on/off when the exclusion signal/restoring signal is input. In this case, each sensor performs detection under the condition that a weft supply system L to which the sensor belongs is excluded from its weft insertion group (that is, a supply weft breakage is occurring). Therefore, a detection signal that is output from each sensor only indicates the transport of a cut weft CC. In this case, it is possible to omit the function of the monitoring unit 15 of storing information regarding an excluded weft supply system.

[0063] In the embodiment, the start of the monitoring period of a cut weft CC in a weft supply system L that has been excluded from its weft insertion group is from when the feeder motor 43 of a weft measuring-storing device 4 stops completely. However, the monitoring period may start when a supply weft breakage occurs or after the passage of a preset time from when a supply weft breakage occurs.

[0064] In the embodiment, a piezoelectric weft passage sensor is used for each sensor (weft supply sensor 3) that detects the movement of a weft C for monitoring a cut weft CC. However, instead, a photoelectric sensor (optical sensor) may also be used. More specifically, for example, each photoelectric sensor includes a light emitter and a photodetector, and is disposed so that the weft C passes an optical axis provided between the light emitter and the photodetector. In addition, a threshold value is set for a change in the amount of light received (amplitude of a signal based on the amount of light received) in each photodetector with respect to detecting means that processes a signal from each sensor. When the change in the amount of light received exceeds the predetermined threshold value, it is determined that a weft C is being moved and a yarn detection signal is output. That is, when the optical axis of each photoelectric sensor (optical sensor) that is provided at a loom is formed so that each weft C passes its corresponding optical axis, the amount of change in the amount of light received (amplitude of a signal based on the amount of light received) is greater when the weft C is being moved than when the weft C is stopped. Therefore, when the threshold value is set and it is determined whether or not the amount of change in the amount of light received exceeds the threshold value, it is possible to detect whether or not the weft C is stopped or is being moved.

[0065] In the embodiment, the monitoring function stop button 13d is provided as the monitoring function stopping means that stops the monitoring function of the monitoring unit 15 when fixing a supply weft breakage in an excluded weft supply system. In addition, in the embodiment, the monitoring function of the monitoring unit 15 itself is turned off. However, the following modifications in items 1) and 2) are possible.

[0066] 1) A switch that turns of/off the detection function may be attached to each sensor itself so that a yarn detection signal is not output from each sensor (weft supply sensor 3) when fixing a supply weft breakage. In this case, the on/off switches that are attached to the corresponding sensors correspond to the monitoring function stopping means.

[0067] 2) It is possible to form a structure in which the output of a yarn detection signal at the weft insertion control circuit 12 is stopped so as not to output the yarn detection signal that is output from a weft supply sensor 3 to the monitoring unit 15 from the weft insertion control circuit 12 when a supply weft breakage is to be fixed in the case where the yarn detection signal is output to the monitoring unit 15 from the sensor (weft supply sensor 3) via the weft insertion control circuit 12 as in the embodiment. In this case, an instruction switch for stopping the output of the yarn detection signal to the weft insertion control circuit 12 is provided at, for example, the setting unit 13, and the weft insertion control circuit 12 is set in a state in which the output of the yarn detection signal is stopped as a result of operating the instruction switch. In this case, the function of stopping the output of a yarn detection signal in the weft supply control circuit 12 and the instruction switch provide the monitoring function stopping means.

[0068] In the embodiment, a restoring signal (that is, a signal for restoring an excluded weft supply system to its weft insertion group) that is output from the weft insertion control circuit 12 is used as means for making effective again the monitoring function of the monitoring unit 15 in the stopped (ineffective) state. However, instead, it is possible to use a structure in which a restoring button that is manually operated by an operator is set at, for example, the setting unit 13, and in which the monitoring function of the monitoring unit 15 is made effective again on the basis of a signal that is output from, for example, the setting unit 13 when an operator manually operates the restoring button.

[0069] In the embodiment, one monitoring unit 15 that is a common monitoring device for the plurality of weft supply systems L monitors the transport of a cut weft CC in an excluded weft supply system. However, instead, each weft supply system L may include a monitoring unit that corresponds to part of the monitoring unit 15. In this case, the combination of the monitoring means that are provided at the respective weft supply systems L correspond to the monitoring unit according to the present invention. In this case, if it is determined that a cut weft CC is transported in an excluded weft supply system of the weft supply systems L to which the corresponding monitoring means belong, each monitoring means outputs an abnormality signal to the weft insertion control circuit 12, and the weft insertion control circuit 12 outputs a loom stop signal to the loom control circuit on the basis of the output abnormality signal. In this case, the function of the weft insertion control circuit 12 of outputting a loom stop signal as a result of receiving the abnormality signal is also part of the monitoring unit 15.

[0070] The structure is not limited to one in which a loom stop signal is output via the weft insertion control circuit 12 as mentioned above. The structure may be one in which each monitoring means outputs a loom stop signal to the loom control circuit. Even in this case, the monitoring means need not be provided with the function of storing information regarding an excluded weft supply system such as that of the monitoring unit 15 according to the embodiment. Instead of providing the monitoring means at each weft supply system L, monitoring means may be provided with a plurality of weft supply systems L that are smaller in number than the total number of weft supply systems L (that is, 1/n of the total, where n is an integer).

[0071] The present invention is not limited to the above-described embodiment. Modifications may be made as appropriate within a range that does not depart from the gist of the present invention.

Claims

1. A weft monitoring method for a fluid jet loom including a weft insertion device (60) including a plurality of weft supply systems (L), each weft supply system (L) including a weft supply package (1), a weft measuring-and-storing device (4), and a weft insertion nozzle (5), the weft insertion device (60) performing weft insertions by successively using the weft supply systems (L) in turn in accordance with a preset weft insertion pattern, the weft insertion device (60) being such that, when a supply weft breakage occurs in any of the weft supply systems (L), the weft insertion device (60) excludes the weft supply system (L) in which the supply weft breakage has occurred and continues the weft insertion using only the other weft supply system (L) or the other weft supply systems (L),
wherein, in the fluid jet loom, sensors that detect movements of wefts are provided, each sensor being provided at a location between the weft supply package (1) and the weft measuring-and-storing device (4) in the corresponding weft supply system (L), and
wherein the weft monitoring method comprises the step of outputting a loom stop signal when the sensor detects the movement of the weft in the weft supply system (L) in which the supply weft breakage has occurred.

2. The weft monitoring method for the fluid jet loom according to Claim 1, wherein each sensor is a weft supply sensor for detecting the supply weft breakage during weaving, each weft supply sensor being included in the corresponding weft supply system.

3. A weft monitoring device for a fluid jet loom including a weft insertion device (60) including a plurality of weft supply systems (L), each weft supply system (L) including a weft supply package (1), a weft measuring-and-storing device (4), and a weft insertion nozzle (5), the weft insertion device (60) performing weft insertions by successively using the weft supply systems (L) in turn in accordance with a preset weft insertion pattern, the weft insertion device (60) being such that, when a supply weft breakage occurs in any of the weft supply systems (L), the weft insertion device (60) excludes the weft supply system (L) in which the supply weft breakage has occurred and continues the weft insertion using only the other weft supply system (L) or the other weft supply systems (L), the weft monitoring device comprising:

sensors that detect movements of wefts, each sensor being provided at a location between the weft supply package (1) and the weft measuring-and-storing device (4) in the corresponding weft supply system (L); and

a monitoring unit that outputs a loom stop signal when the sensor has detected the movement of the weft under the condition that the supply weft breakage is occurring in the weft supply system (L) in which the sensor is included.

4. The weft monitoring device for the fluid jet loom according to Claim 3, wherein each sensor is a weft supply sensor for detecting the supply weft breakage during weaving, each weft supply sensor being included in the corresponding weft supply system.

Drawing