(19)
(11)EP 1 325 892 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
11.05.2011 Bulletin 2011/19

(21)Application number: 02749314.7

(22)Date of filing:  17.07.2002
(51)International Patent Classification (IPC): 
C03B 23/025(2006.01)
C03B 23/033(2006.01)
C03B 35/18(2006.01)
(86)International application number:
PCT/JP2002/007268
(87)International publication number:
WO 2003/008349 (30.01.2003 Gazette  2003/05)

(54)

Glass plate curving apparatus

Krümmungsvorrichtung für Glasplatten

Appareil de cintrage de verre


(84)Designated Contracting States:
BE CZ DE FR GB IT

(30)Priority: 18.07.2001 JP 2001217759

(43)Date of publication of application:
09.07.2003 Bulletin 2003/28

(73)Proprietor: ASAHI GLASS COMPANY LTD.
Tokyo 100-8405 (JP)

(72)Inventors:
  • NEMUGAKI, Youichi, Asahi Glass Company, Limited
    Chita-gun, Aichi 470-2514 (JP)
  • SATO, Toshimitsu, Asahi Glass Company, Limited
    Chita-gun, Aichi 470-25 14 (JP)

(74)Representative: Müller-Boré & Partner Patentanwälte 
Grafinger Straße 2
81671 München
81671 München (DE)


(56)References cited: : 
EP-A- 1 006 086
EP-A2- 1 006 086
JP-A- 10 218 629
US-A- 4 820 327
EP-A1- 1 020 412
WO-A-91/03432
US-A- 4 139 359
  
      
    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

    TECHNICAL FIELD



    [0001] The present invention relates to an apparatus for bending a glass sheet and a curved roller, particularly, to an apparatus for bending a glass sheet used for transporting machines such as automobiles, vessels, trains and aircrafts, buildings and other various applications, and a curved roller.

    BACKGROUND ART



    [0002] The inventors of the present application proposed in JP-A-2000-72460 a forming apparatus for bending a glass sheet heated to a temperature close to the softening point in a heating furnace into a glass sheet having a desired curvature. This apparatus conveys a glass sheet heated in the heating furnace, along a conveying plane defined by a plurality of rollers of a roller conveyer, and by moving the rollers up and down according to the position of the glass sheet, a part of the conveying plane is bent with respect to the glass sheet conveying direction and the glass sheet is bent to have a desired curvature.

    [0003] Meanwhile, US patent No. 4,123,246 discloses an apparatus for bending a glass sheet heated to a temperature close to the softening point in a heating furnace, by conveying the glass sheet on a roller conveyer constituted by a plurality of curved rollers each curved with respect to the direction perpendicular to the glass sheet conveying direction.

    [0004] According to the apparatus disclosed in the above two documents, the softened glass bends down by its own weight along the curved plane, whereby the glass sheet can be bent according to the curved conveying plane.

    [0005] However, although JP-A-2000-72460 discloses that a glass sheet is formed to have a plane curved with respect to the glass sheet conveying direction, it does not disclose that a glass sheet is formed to have a plane curved with respect to the direction perpendicular to the glass sheet conveying direction.

    [0006] Further, the conventional apparatus for bending disclosed in US patent No. 4,123,246 had a problem that although it could form a glass sheet to have a curved plane with respect to the direction perpendicular to the glass sheet conveying direction, it could not form a glass sheet to have a curved plane with respect to the glass sheet conveying direction.

    [0007] Both of these apparatuses have a conveying plane curved only with respect to one direction, and therefore, it is difficult to form a complicatedly curved glass having a plane curved with respect to two directions.

    [0008] EP-A-1 006 086 discloses a glass bending process and a corresponding apparatus with longitudinally spaced roll-forming units for shaping or otherwise bending a heated flat glass sheet into a desired curvature. Each of the roll forming units is composed of a pair of upper and lower forming roll mechanisms and having upper and lower forming rolls and, respectively. The upper and lower forming rolls and are downwardly bowed or arched, and they are rotated at the same peripheral speed, so that the flat glass sheet, as it is passed between the upper and lower forming rolls, is bent or curved about an axis thereof extending parallel to the direction of conveyance of the glass sheet. By the bending section thus arranged, the flat glass sheet is bent or curved in the transverse direction. Moreover, a bi-directional bending process is also disclosed.

    [0009] US-A-4 139 359 describes the shaping of heat-softened glass sheets into either simple or compound bends while being continuously conveyed by means of forming rolls having transverse curvature, wherein, in at least the first position of the bending station, the force of gravity alone causes the glass sheets to sag into substantial conformity with the transverse curvature of the forming rolls. Support for each glass sheet is gradually transferred from straight conveyor rolls to curved forming rolls without vertically reciprocating the rolls. Optionally, at the exit end of the forming station, a set of upper forming rolls having transverse curvature complementary to that of the lower forming rolls may be provided to assure close conformance to the desired curvature.

    [0010] It is an object of the present invention to solve the above problems of the conventional techniques, and to provide a curved roller whose curvature can optionally be changed, and an apparatus for bending a glass sheet, so that a glass sheet having a complicatedly curved shape can be produced.

    [0011] This object is solved by an apparatus for bending a glass sheet having the features defined in claim 1. Preferred embodiments are defined in the dependent claims.

    DISCLOSURE OF THE INVENTION



    [0012] The present invention provides an apparatus for bending a glass sheet, comprising a heating furnace to heat a glass sheet to a bending temperature, and a roller conveyer having a plurality of rollers to convey the heated glass sheet along a conveying plane defined by the rollers, said rollers being movable up and down according to the position of the glass sheet, to have a part of said conveying plane bent with respect to the conveying direction of the glass sheet thereby to let the glass sheet bend by its own weight to have a desired curvature; characterized in that said rollers are curved rollers, wherein said rollers are curved rollers, wherein said curved rollers each has a guide-shaft formed to have a desired curvature, and a plurality of ring rollers rotatably fitted on the guide-shaft so that they rotate about the axial center of the guide-shaft, wherein rotating driving means for rotating an outer cylinder covering the end of the guide-shaft are provided at one end or at both ends of the guide-shaft, and wherein driving means for moving up and down the outer cylinder and the guide shaft are provided at one end or at both ends of the guide-shaft, so that the outer cylinder and the guide-shaft are bendable by operation of the driving means, so as to bend the conveying plane defined by the plurality of ring rollers:

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0013] 

    Fig. 1: A perspective view illustrating an embodiment of an apparatus for bending a glass sheet according to the present invention.

    Fig. 2: A view illustrating up/down movement of curved rollers according to the position of a glass sheet being conveyed.

    Fig. 3: A view illustrating a mechanism for moving a curved roller up and down.

    Fig. 4: A view illustrating a curved roller of a first embodiment.

    Fig. 5: An enlarged cross-sectional view of the substantial part of the curved roller shown in Fig. 4.

    Fig. 6: A view illustrating a curved roller that does not belong to the scope of the invention.

    Fig. 7: An exaggerated cross-sectional view of the curved roller shown in Fig. 6.

    Fig. 8: An exaggerated cross-sectional view of the curved roller formed to have a barrel shape.

    Fig. 9: A view illustrating a curved roller of a third embodiment.

    Fig. 10: An enlarged cross-sectional view of the substantial part of the curved roller shown in Fig. 9

    Fig. 11: A vertical cross-sectional view of the curved roller shown in Fig. 9.

    Fig. 12: A diagram of the substantial part of the curved roller shown in Fig. 9.

    Fig. 13: A view illustrating a curved roller of a fourth embodiment.

    Fig. 14: A side view illustrating another embodiment of the curved roller.

    Fig. 15: An enlarged view of the substantial part of Fig. 14.

    Fig. 16: A perspective view illustrating an apparatus for bending a glass sheet by its own weight.


    BEST MODE FOR CARRYING OUT THE INVENTION



    [0014] Now, preferred embodiments of an apparatus for bending a glass sheet, according to the present invention, will be described with reference to drawings.

    [0015] Fig. 1 is a perspective view illustrating an embodiment of an apparatus for bending a glass sheet. As illustrated in the view, an apparatus 10 for bending is constituted by a heating furnace 16, a forming zone 16a and an air-cooling/tempering apparatus 16b as main components. Further, the driving control of each part of the apparatus 10 for bending is carried out by a motion controller CNT constituted by e.g. a computer.

    [0016] Firstly, the bending step of a glass sheet 18 by the apparatus 10 for bending, will be described. The glass sheet 18 before bending is positioned to a conveying position at the entrance of the heating furnace 16, and is conveyed into the heating furnace 16 by a roller conveyer, not shown. Then, the glass sheet 18 is heated by a heater in the heating furnace 16 while it is conveyed in the heating furnace 16, whereby it is heated up to the bending temperature (about from 600 to 700°C) at the exit of the heating furnace 16. The glass sheet 18 heated up to the bending temperature, is conveyed by a roller conveyer 13a for bending to the forming zone 16a provided on a downstream side of the heating furnace 16.

    [0017] Rollers constituting the roller conveyer 13a, are each a curved roller curved vertically downward in a convex form so as to form, in the glass sheet 18, a curved plane curving with respect to the direction perpendicular to the conveying direction. And further, by moving up and down each roller of the roller conveyer 13a like the propagation of a wave while the glass sheet 18 is conveyed in the forming zone 16a, the glass sheet 18 will have a curved plane curving with respect to the conveying direction. As a result, the glass sheet 18 can be formed to have a curved plane having a curvature with respect to two directions. Here, rollers curving vertically upward in a convex form, can also be employed, but from a viewpoint of stability of conveying the glass sheet 18, rollers curving vertically downward in a convex form, are more excellent.

    [0018] The bent glass sheet 18 is conveyed from the exit of the forming zone 16a into the air-cooling/tempering apparatus 16b by a roller conveyer 13b of the air-cooling/tempering apparatus 16b, to be tempered by air-cooling. The air-cooling/tempering apparatus 16b has an upper blowing head 17a and a lower blowing head 17b disposed sandwiching the roller conveyer 13b, and the glass sheet 18 is cooled and tempered by air blown from the blowing heads 17a and 17b towards the glass sheet 18.

    [0019] Here, the cooling performance of the air-cooling/tempering apparatus 16b is appropriately set depending on e.g. a thickness of the glass sheet 18. The glass sheet 18 tempered by air-cooling, is conveyed to the inspection apparatus (not shown) as the next step by a roller conveyer 13c from the exit of the air-cooling/tempering apparatus 16b. This is all about the bending step of the glass sheet 18 in the apparatus 10 for bending.

    [0020] Curved rollers 12A to 12M, ···, constituting the roller conveyer 13(13a, 13b and 13c) shown in Fig. 2, are each independently rotated by a rotation driving means (not shown), and each independently moved up and down by an elevating means (not shown). As illustrated in (A) to (E) in the view, the conveying plane of the glass sheet 18 constituted by the rollers, deforms like the propagation of a wave from upstream side to downstream side. As a result, the curvature of the glass sheet 18, gradually increases as it is conveyed from upstream side to downstream side. Here, the driving of these rotation driving means and elevating means, are controlled by a motion controller CNT in Fig. 1.

    [0021] Fig. 3 is a diagram illustrating a rotation driving means and a elevating means of each of the curved rollers 12A to 12M, ···. Here, since the rotation driving means and the elevating means of the curved rollers 12A to 12M, ···, have the same structure, Fig. 3 illustrates only the structure of a curved roller 12A, and the description regarding the structure of other curved rollers 12B to 12M, ···, is omitted for convenience.

    [0022] The curved roller 12A is rotatably supported at its both ends via bearings 32, 32 by a movable frame 30 formed to have a concave shape. Further, to the left end of the curved roller 12A in Fig. 3, a gear 34 is attached as shown in Fig. 4, and the gear 34 is engaged with a gear 36 at a side of a servo motor 38. Accordingly, by driving the servo motor 38, the curved roller 12A is rotated at a predetermined angular speed. This is all about the structure of the rotation driving means.

    [0023] On the other hand, the movable flame 30 is, as illustrated in Fig. 3, supported at its both sides by a fixed frame 42 via a LM (linear motion) guide so as to be movable up and down. This LM guide comprises a guide rail 44 disposed vertically at a side of the movable frame 30, and linear motion guides 46, at a side of the fixed frame 42, engaged with this guide rail 44.

    [0024] Further, at both ends of a lower portion of the movable frame 30, racks 48, 48 are provided so as to protrude downward therefrom, and pinions 50, 50 are engaged with the racks 48, 48. The pinions 50, 50 are fixed to a rotational shaft 52 provided horizontally, and the rotational shaft 52 is supported by the bearings 54, 54 at its both ends, and its left end portion in Fig. 3 is connected to a spindle 58 of a servo motor 56. Therefore, when the servo motor 56 rotates the rotation shaft 52, the rotational movement is converted to a linear movement by the effect of the pinions 50 and the racks 48, and a curved roller 12A is moved up and down together with the movable frame 30. That is all about the structure of the elevating means. Here, numeric symbols 60, 62 in Fig. 3 indicate heaters provided in the heating furnace 16. Further, in a case of an out-furnace apparatus for bending having curved rollers 12A to 12M, ···, provided outside the furnace, the heaters 60, 62 are not provided.

    [0025] The rotation driving means and the elevating means described above, are provided for all of other curved rollers 12A to 12M, ···, and the servo motors 38, 56 for those means are controlled by a motion controller CNT in Fig. 1.

    [0026] When the type of the glass sheet 18 is input from an external input means not shown, the motion controller CNT prepares angular speed control data and up/down movement control data of the curved rollers 12A to 12M, ···, which correspond to the curvature of the glass sheet 18 of the type. Then, the motion controller CNT controls the servo motors 38 based on the angular speed control data prepared, and controls the servo motors 56 based on the up-down movement control data. Namely, the motion controller CNT carries out multi-axis control of the curved rollers 12A to 12M, ···, so that the glass sheet 18 is bent to have a desired curvature during the conveyance by the curved rollers 12A to 12M, ···.

    [0027] Secondly, the multi-axis control method of the curved rollers 12A to 12M by the motion controller CNT will be described. Basic up/down movement of the rollers is such that according to the conveyance of a glass sheet G, down-movement and up-movement of the curved rollers 12A to 12M, ···, are carried out sequentially in this order.

    [0028] The curved rollers 12A to 12M, ···, subjected to multi-axis control by the motion controller CNT, behave such that for example as illustrated in Fig. 2(A), when the heated glass sheet 18 reaches the entrance side curved roller 12A, all the curved rollers 12A to 12M, ···, are at the top position, and the curved conveying path 14 defined by the curved rollers 12A to 12M, ···, is curving only with respect to a B direction (the direction perpendicular to the glass sheet conveying direction) in Fig. 1. Thereafter, when the glass sheet 18 is further conveyed, the curved rollers 12B and 12C move down.

    [0029] Then, when the glass sheet 18 is conveyed as illustrated in Fig. 2(B), the curved rollers 12D to 12F move down, whereby among the conveying path 14 defined by the curved rollers 12A to 12M, ···, a curved conveying path defined by the curved rollers 12D to 12F deforms to curve in a gentle downward convex form having a large curvature radius. Namely, the curved conveying path deforms with respect to the direction of A (glass sheet conveying direction) in Fig. 1. Consequently, when the glass sheet 18 passes on the curved rollers 12D to 12F, the glass sheet 18 bends downwardly by its own weight along a conveying plane defined by the curved rollers 12D to 12F, and deforms to have a shape along the curved plane. Consequently, the glass sheet 18 is formed to be a complicatedly curved glass.

    [0030] Thereafter, when the glass sheet 18 is further conveyed as illustrated in Fig. 2(C), the curved rollers 12F to 12H move down more deeply than the previous curved rollers 12D to 12F, whereby a curved conveying path defined by the curved rollers 12F to 12H deforms to have a curved shape having a smaller curvature radius (sharply curved) than the previous curved conveying path. Consequently, when the glass sheet 18 passes on the curved rollers 12F to 12H, the glass sheet 18 further bends downwardly along the conveying plane defined by the curved rollers 12F to 12H, and is deformed to have a shape along the curved plane

    [0031] Thereafter, when the glass sheet 18 reaches a substantially middle point of the curved conveying path as illustrated in Fig. 2(D), the curved rollers 12H to 12J move down more deeply than the previous curved rollers 12F to 12H, whereby a two-directional conveying plane defined by the curved rollers 12H to 12J, deforms to have a curved shape having a smaller curvature radius than the previous curved plane. Consequently, when the glass sheet 18 passes on the curved rollers 12H to 12J, the glass sheet 18 bends downwardly along the conveying plane defined by the curved rollers 12H to 12J, and is deformed to have a shape along the conveying plane.

    [0032] Thereafter, when the glass sheet 18 reaches a downstream side of the curved conveying path as illustrated in Fig. 2(E), the curved rollers 12J to 12L move down more deeply than the previous curved rollers 12H to 12J, whereby a conveying plane defined by the curved rollers 12J to 12L deforms into a curved shape having a curvature corresponding to the finally obtainable curvature of the glass sheet 18. Consequently, when the glass sheet 18 passes on the curved rollers 12J to 12L, it is deformed to have a shape along the conveying plane, whereby it is bent to have a desired curvature. That is all about the bending operation of the glass sheet 18 by the above curved rollers 12A to 12M.

    [0033] As described above, the apparatus 10 for bending of this embodiment employs, as rollers of a roller conveyer in an apparatus for bending a glass sheet with respect to the glass sheet conveying direction by moving the rollers up and down, curved rollers 12 each having the surface curved with respect to the direction perpendicular to the glass sheet conveying direction. Consequently, a complicatedly curved glass curved along the conveying direction and along the horizontal direction perpendicular to the conveying direction, can be produced.

    [0034] In the following, an embodiment of the curved roller 12 will be described.

    [0035] Fig. 4 and Fig. 5 show a curved roller 12 of the first embodiment. In the curved roller 12, a plurality of ring rollers 72, 72, ···, are rotatably supported by a guide shaft 70 preliminarily bent to have a predetermined curvature. A ring roller 72 is constituted by a roller body 74 and a color 76. The roller body 74 is formed to have a tubular form, and has in its central portion a large diameter perforation 78 opening to one end and a small diameter perforation 80 opening to the other end. The small diameter perforation 80 is formed to have a larger diameter than the outer diameter of the guide shaft 70. A bush 82 is inserted in the large diameter perforation 78, and the bush 82 is fitted to the guide shaft 70. Consequently, the plurality of ring rollers 72, 72, ···, are rotatably supported by the guide shaft 70.

    [0036] Further, annular ribs 84, 84 are formed on both ends of the roller body 74 of the ring roller 72, and threaded holes 86, 86, ···, are formed at two positions in the outer peripheral surface of each of the ribs. Further, a color 76 is fitted to the outer peripheral surface of the roller body 74 by e.g. shrinkfitting. The color 76 has a width substantially same as the total width of the roller body 74, and a hole 88 is formed in the extension of a threaded hole 86 of the roller body 74.

    [0037] Adjacent ring rollers 72, 72 are connected each other by an elastic tubular member 90 made of rubber attached to their circular ribs 84, 84. Namely, the elastic tubular member 90 has perforations 92 at both ends, and is connected by screws 94 each inserted in a perforation 92 and screwed in the threaded hole 86 of the rib 84. Such elastic tubular member 90 has an inflated portion 90A formed in the entire circumference at the middle portion in its width direction.

    [0038] Further, the curved roller 12 has a sprocket housing 96 at a left end of the ring roller 72. The sprocket housing 96 is rotatably supported by the guide shaft 70 via bushes 98. The sprocket housing 96 has a circular rib 100 formed on a ring roller 72 side end, and threaded holes 102 are formed at two positions in the circular rib 100. To each of the circular rib 100 and the circular rib 84 of the ring roller 72, an end portion of the elastic tubular member 90 made of rubber is fitted. The screws 94 each inserted in the perforation 92 of the elastic tubular member 90 are screwed in the threaded hole 86 of the circular rib 84, and screws 104 each inserted in the perforation 92 of the elastic tubular member 90 are screwed in the threaded hole 102 of the circular rib 100, whereby the sprocket housing 96 and the ring roller 72 are mutually connected. Further, a gear 34 is fixed to the sprocket housing 96.

    [0039] Here, the connection between the sprocket housing 106 and the ring roller 72 on a right side in Fig. 4, is also achieved by an elastic tubular member 90 made of rubber in the same manner as in the connection between the sprocket housing 96 and the ring roller 72 on a left side, and its connection structure is also the same. Therefore, the description will be omitted.

    [0040] The curved roller 12 thus constituted, has a guide shaft 70 preliminarily curved, whereby the curved conveying path 14 curved with respect to the direction perpendicular to the glass sheet conveying direction can be formed. Further, in this curved roller 12, when the gear 34 is rotated by a servo motor 38, the torque is transmitted to the ring rollers 72, 72, ···, via elastic tubular members 90, 90, ···. Accordingly, the conveying power of the glass sheet 18 can be obtained.

    [0041] Fig. 6 and Fig. 7 show a curved roller 110 that does not belong to the scope of the invention. Here, Fig. 7 is an enlarged cross-sectional view showing the curved roller 110 of Fig. 6 with exaggeration. In these Figures, the curved roller 110 is formed to have an hourglass shape. The curved roller 110 comprises a core shaft 114 formed to have a straight rod-shape and connected to a servo motor 112 to be rotated, a driving rotor 116 formed integrally with the core shaft 114 at the central portion in the axial direction of the core shaft 114, and a pair of driven rotors 118, 118 supported by the core shaft 114 on both sides of the driving rotor 116 and each formed to have a substantially frustum conical shape.

    [0042] According to the curved roller 110, a curved line curved with respect to the direction perpendicular to the glass sheet conveying direction is defined by a ridge line L of each of the driving rotor 116 and driven rotors 118, 118. Therefore, by disposing a plurality of such curved rollers 110, a curved conveying path can be defined.

    [0043] By the way, if the driven rotors 118, 118 are integrally formed with the core shaft 114 like the driving rotor 116, the driven rotors 118, 118 have larger diameters than the driving rotor 116, and accordingly, peripheral velocities of the driven rotors 118, 118 are larger than that of the driving rotor 116. Therefore, due to a difference of peripheral velocity, slipping will occur between each of the rotors 116, 118, and the glass sheet, which may cause a scratch on the surface of the glass sheet.

    [0044] For this problem, the curved roller 110 is so constructed that the driving rotor 116 is formed integrally with the core shaft 114, and the driven rotors 118, 118 are driven by the core shaft 114. Accordingly, the driven rotors 118, 118 idle about the core shaft 114 to cancel the above peripheral velocity difference. Therefore, the slip as mentioned above does not occur and glass sheet can be bent well.

    [0045] Here, instead of the hourglass-shaped curved roller 110, a barrel-shaped curved roller 110A shown in Fig. 8 may be applied. This curved roller 110A has a driving rotor 116A formed integrally with a core shaft 114 at the central portion in the axial direction of the core shaft 114, and a pair of driven rotors 118A, 118A supported by the core shaft 114 on both sides of the driving rotor 116A. According to this curved roller 110A, the ridge line L' is formed in the opposite direction to the hourglass-shaped curved roller 110 shown in Fig. 7.

    [0046] Fig. 9 to Fig. 11 show a curved roller 120 of the third embodiment. The curved roller 120 has a rod-shaped curved rod 124 comprising a plurality of oval link members 122, 122, ···, wherein adjacent link members 122, 122 are swingably connected one another via the gear portions 123, 123 in Fig. 10, and a plurality of ring rollers 126 rotatably fitted on the curved rod 124 and rotatable about the axial center P of the curved rod 124.

    [0047] Further, to a link member 122 at left end side of the curved rod 124 in Fig. 9, a rod portion 172 of a hydraulic cylinder 170 for moving the link member 122 up and down, is connected via a linear motion guide member 174. Further, the link member 122 on the left end side in Fig. 9 is provided on the top end of the rod portion 172 via a pin 176 so as to be swingable in a vertical direction. Here, instead of the hydraulic cylinder 170, an elevating mechanism employing a servo motor and a ball screw device, may be applied. By this elevating mechanism, an up/down stroke control of the link member 122 will become possible.

    [0048] The curved rod 124 is constituted by a first link structure 122 and a second link structure 130. As illustrated in Figs. 11 and 12, adjacent link members 122-1, 122-2 are swingably supported by a link member 132 via pins 130, and each of the pins 130 is inserted in pinholes 122a, 132a of the link members 122-1, 132-2, whereby they are swingably supported by the ring roller 126. A link member 132-1 has an identical shape with the link member 122-1, and is attached to the link member 122-1 at a position shifted by a half length of the link member 122-1, and connected with an adjacent link member 132-1 via a gear portion, not shown.

    [0049] Accordingly, when the left end portion of the link structure 122 at the left end of the Fig. 9 is elevated by elevating the rod portion 172 of the hydraulic cylinder 170 shown in Fig. 9, the left end link member is rotated about the pin 176 in the clockwise direction, and the rotation propagates via gear portions 123, 123 to adjacent link members 122-1, 132-1, 122-2, 132-2, ···. By this operation, the crossing angles defined by adjacent pairs of link member 122-1, 132-1, 122-2, 132-2, ···, gradually increase while maintaining the all angles to be equal. Accordingly, the curved rod 124 is curved downward in a convex form having a single curvature.

    [0050] When the curved rod 124 is curved, cores 126A and each of the ring rollers 126, 126, ···, swing along the curved rod 124, and as a result, the curved roller 120 is curved with a single curvature with respect to the direction perpendicular to the glass sheet conveying direction. Further, by adjusting the amount of elevation given to the curved rod 124, the curvature of the curved rod 124, namely the curvature of the curved conveying path, can be adjusted. Accordingly, a different type of glass sheet having a different model (curvature) can be formed by a single type of curved rollers 120. By this effect, the job change of the curved roller accompanied by the change of the glass sheet model, is substantially eliminated.

    [0051] Here, a gear 134 is fixed to the ring roller 126 on left end side in Fig. 9, and with the gear 134, a driving gear 140 connected to a spindle 138 of a servo motor 136, is engaged. Further, the ring rollers 126, 126, ···, are connected by elastic tubular members 142, 142, ···, as shown in Fig. 10. Accordingly, by applying the torque of the servo motor 136 to the ring roller 126 at a left end side in Fig. 9, all of the ring rollers 126, 126, ···, are rotated whereby the conveying power for a glass sheet can be obtained. Further, the servo motor 136 is installed on a platform 178 attached to the link member 122 at the left side end in Fig. 9 so as to move up and down together with the link member 122.

    [0052] Fig. 13 illustrates a curved roller 150 of the fourth embodiment. The curved roller 150 has a flexible shaft 152 constituted to be bendable, a plurality of ring rollers 154, 154, ···, fitted on the flexible shaft 152 so as to rotate about the axial center of the flexible shaft 152, and a link structure 124 (corresponding to the conveying plane curving means in Claim) for bending the flexible shaft 152 into a desired curvature to thereby curve the conveying plane defined by the plurality of ring rollers. The curved rod 124 and the flexible shaft 152 are connected via bearings 156. By curving the curved rod 124, the flexible shaft 152 is bent along the curved rod 124, and the conveying plane defined by the ring rollers 154, 154, ···, is curved with respect to the direction perpendicular to the glass sheet conveying direction.

    [0053] Further, to the left end portion of the flexible shaft 152 in Fig. 13, a gear 158 is fixed. And with the gear 158, a driving gear 164 connected to a spindle 162 of a servo motor 160, is engaged. Further, the ring rollers 154, 154, ···, are connected via annular connecting members 166. Accordingly, by providing a torque of the servo motor 160 to the flexible shaft 152, all of the ring rollers 154, 154, ···, are rotated whereby the conveying force for the glass sheet can be obtained.

    [0054] The left end portion of the curved rod 124 in Fig. 13 is connected to a spindle 184 of a servo motor 182 via a ball screw device 180 which moves up and down. Further, to a nut portion 186 of the ball screw device 180, a platform 188 is horizontally connected, and a servo motor 160 is mounted on this platform. Therefore, when the nut portion 186 is moved up and down by rotating the ball screw device 180 by the servo motor 182, the curved rod 124 is moved up and down together with the servo motor 160 to create a single curvature.

    [0055] Fig. 14 and Fig. 15 show another embodiment of the curved roller. Since the roller portion as the main portion for defining the conveying plane of the curved roller 190, has the same construction as the curved roller 12 shown in Fig. 5, members same as or similar to the members of the curved roller 12 are identified with the same numeric symbols. The guide shaft 70 (Fig. 5) of the curved roller 190, is made of a material (for example S45C) bendable due to an elastic deformation and formed to have a straight rod-shape. A plurality of ring rollers 72, 72, ···, fitted on the guide shaft 70, are each connected with an adjacent one via an elastic tubular member made of a rubber, to constitute a single hollow roller structure 192 as a whole.

    [0056] Both ends 70A of the guide shaft 70 are protruded from both ends 192A of the hollow roller structure 192 by a predetermined length as shown in Fig. 15, and an outer cylinder 194 covering a protruded end 70A, is disposed. One end 194A of the outer cylinder 194, is connected to an end 192A of the hollow roller structure 192, and supported by a supporting member 198 via a bearing 196. Further, the bearing 196 is supported by the supporting member 198 via a horizontally implanted pin 199, so that the outer cylinder 194 and the end 70A of the guide shaft 70 (Fig. 5) can be bent with an elasticity as shown by double dotted lines in Fig. 15. Here, the supporting member 198 is fixed to a stand 200 supporting the entire curved roller 190.

    [0057] The other end 194B of the outer cylinder 194, is connected to a bracket 204 via a bearing 202. The bearing 202 is rotatably connected to the bracket 204 via a horizontally implanted pin 206, whereby the bending of the outer cylinder 194 and the end 70A of the guide shaft 70 indicated by double dotted lines in Fig. 15, can be permitted when the bracket 204 is elevated.

    [0058] To a lower portion of the bracket 204, a slider 208 is connected, and the slider 208 is connected to a feed screw device 210 for moving up and down the slider 208. The feed screw device 210 is driven by a driving force of a motor 212. Here, the feed screw device 210 is fixed to a leg portion 201 of the stand 200.

    [0059] Further, the other end 194B of the outer cylinder 194, is connected to an output shaft 220 of a motor 218 via a gear 214 and a gear 216. In this construction, when the motor 218 is driven, the torque is transmitted via the gear 216, the gear 214 and the outer cylinder 194 to the hollow roller structure 192, whereby the hollow roller structure 192 is rotated. Here, the gear 214 is rotatably supported by the guide shaft 70, and the gear 216 is rotatably supported by a bearing portion 224 of an inclination guide frame 222.

    [0060] The inclination guide frame 222 has one end attached to the supporting member 198 via pins 226, 226 so as to be inclined, and has the bearing portion 224 formed at the other end. Therefore, the inclination guide frame is inclined according to the bending of the outer cylinder 194 and the end portion 70A of the guide shaft 70 shown by the double dotted lines in Fig. 15. Further, a stopper pin 228 is provided underneath the inclination guide frame 222, and a head portion 229 of the stopper pin 228 is in contact with a stopper plate 230 of the leg portion 201 to limit the inclination angle of the inclination guide frame 222, whereby bending amounts of the outer cylinder 194 and the end portion 70A (refer to double dotted lines in Fig. 15) of the guide shaft 70 are limited.

    [0061] When the slider 208 is elevated by the feed screw device 210 driven by the motor 212, the force is transmitted via the bracket 204 to the pin 206, and via this pin 206, the outer cylinder 194 is pushed upward as it is pivoted by the pin 199. By this operation, the outer cylinder 194 and the end portion 70A of the guide shaft 70 are bent as illustrated by the double dotted lines in Fig. 15, and according to this, the hollow roller structure 192 is bent downwardly in a convex form as illustrated by double dotted lines in Fig. 14. Accordingly, the curved roller 190 is curved. The curving angle of the curved roller 190 can be adjusted by controlling the elevated position of the slider 208.

    [0062] Here, since the pin 206 as a power point is apart by a predetermined distance from the pin 199 as a pivotal point, the curved roller 190 can be curved with a small power without applying an unreasonable power. Further, the right end portion of the guide shaft 70 in the Figure, has substantially the same construction as the above construction. Namely, the driving means for moving up and down the outer cylinder 194 and the guide shaft 70, are provided at both ends of the guide shaft 70, while the rotating driving means for rotating the outer cylinder 194, is provided only at one end of the guide shaft 70. However, as the case requires, the rotating driving means may be provided at both ends of the guide shaft 70, or a means for moving the outer cylinder 194 and the guide shaft 70 up and down may be provided only at one end of the guide shaft 70 wherein the guide shaft 70 at the other end may only be supported so as to be movable up and down by employing e.g. LM guide.

    [0063] Further, in Figs. 14 and 15, the hollow roller structure 192 and the outer cylinder 194 are connected via the bearing 196, and the hollow roller structure 192 is rotated by rotating the outer cylinder 194. However, since a very large load is applied to the bearings 196 and 202 in order to curve the guide shaft 70 (Fig. 5), a high durability withstanding the load is required to these bearings. For this problem, it is preferred to attach a gear at the end of the hollow roller structure 194 so that the torque of the motor is transmitted to the end of the hollow roller structure 192 without the bearing 196. It becomes unnecessary to use the outer cylinder 194, and the bearings 196 and 202 becomes unnecessary, whereby the above problem will be solved.

    [0064] In the above, description has been made with respect to an example of an apparatus for bending which moves up and down each roller of the roller conveyer independently, but the present invention is not limited thereto. Namely, the curved roller 110, 110A, 120, 150 or 192 illustrated in Figs. 16 to 15 may be applied to the apparatus for bending shown in Fig. 16. Further, these curved rollers may be installed not only in the forming zone but also in the cooling zone where the air-cooling/tempering apparatus is installed, or in the subsequent step. Namely, by installing the curved rollers between the upper and lower blowing ports, the glass sheet is pushed toward the curved rollers by a wind pressure of the air blown from the blowing ports, whereby not only the bending by its own weight in the forming zone, but also the bending by the wind pressure in the air-cooling zone can be carried out.

    [0065] The apparatus 10 for bending a glass sheet shown in Fig. 16, has a roller conveyer 13 constituted by a plurality of curved rollers 12, 12, ···. The specific construction of each of the curved rollers 12, 12, ···, is as illustrated in Figs. 6 to 15. The curved rollers 12, 12, ···, are disposed substantially in parallel to each other, and a curved conveying path 14 curving along the horizontal direction (the direction indicated by an arrow B in Fig. 16) perpendicular to the glass sheet conveying direction (the direction indicated by an arrow A in Fig. 16), is formed in a roller conveyer 13. The conveying path 14 is formed from the exit of the heating furnace 16 toward the air-cooling/tempering apparatus, not shown, installed outside the heating furnace 16. The driving control of each part is carried out by a motion controller CNT.

    [0066] Further, the curvature of the curved conveying path 14 with respect to the direction of arrow B, gradually increases from the upstream side of the curved conveying path 14 towards the downstream side, and becomes a curvature corresponding to the curvature of the produced glass sheet at the most downstream side of the curved conveying path 14. Therefore, the glass sheet 18 conveyed in the heating furnace 16 is bent gradually by its own weight according to the curvature of the curved conveying path 14, and bent to have a curvature corresponding to the produced glass sheet at the most downstream side of the curved conveying path 14.

    INDUSTRIAL APPLICABILITY



    [0067] As described above, according to the apparatus for bending a glass sheet according to the present invention, a complicatedly curved glass having a curved plane with respect to two directions can be formed.


    Claims

    1. An apparatus for bending a glass sheet (18), comprising a heating furnace (16) to heat a glass sheet (18) to a bending temperature, and a roller conveyer (13) having a plurality of rollers(12A - 12M) to convey the heated glass sheet (18) along a conveying plane defined by the rollers (12A - 12M), said rollers (12A - 12M) being movable up and down according to the position of the glass sheet (18), to have a part of said conveying plane bent with respect to the conveying direction of the glass sheet (18) thereby to let the glass sheet (18) bend by its own weight to have a desired curvature;
    wherein said rollers (12A -12M) are curved rollers (12A -12M),
    wherein said curved rollers (12A - 12M) each has a guide-shaft (70) formed to have a desired curvature, and a plurality of ring rollers (72) rotatably fitted on the guide-shaft (70) so that they rotate about the axial center of the guide-shaft (70),
    wherein rotating driving means for rotating an outer cylinder (194) covering the end (70A) of the guide-shaft (70) are provided at one end (70A) or at both ends (70A) of the guide-shaft (70), and
    wherein driving means for moving up and down the outer cylinder (194) and the guide shaft (70) are provided at one end (70A) or at both ends (70A) of the guide-shaft (70), so that the outer cylinder (194) and the guide-shaft (70) are bendable by operation of the driving means, so as to bend the conveying plane defined by the plurality of ring rollers (72).
     
    2. The apparatus for bending a glass sheet (18) according to claim 1,
    characterized in that each of said curved rollers (12A - 12M) has a guide shaft (70) being bendable by an elastic deformation,
    a hollow roller structure (192) rotatably fitted on said guide-shaft (70), and having a shorter length than the total length of said guide-shaft (70),
    a first outer cylinder (194) covering one end (70A) of said guide-shaft (70) protruding from said hollow roller structure (192), and
    a second outer cylinder (194) covering the other end (70A) of said guide-shaft (70) protruding from said hollow roller structure (192),
    wherein one end of each of said first and second outer cylinders (194) is connected to the respective end of said hollow roller structure (192), and supported by a supporting member (198) on a stand (200) via a bearing (196); the other end of said first and/or second outer cylinder (194) is supported by said stand (200) via an elevating mechanism, said other end of said first and/or second outer cylinder (194) is connected to a predetermined rotation-driving means so that a torque can be transmitted, whereby
    said guide-shaft (70) and said hollow roller structure (192) are curved by elevating the other end of said first and/or second outer cylinder (194) about said supporting member (198) as a fulcrum point by said elevating mechanism, and the conveying plane defined by said hollow roller structure is curved.
     
    3. The apparatus for bending a glass sheet (18) according to claim 2, wherein said follow roller structure (192) is constituted by a plurality of ring rollers (72) in which said shaft (70) is inserted, and a plurality of flexible tubular members for connecting the ring rollers (72) to one another.
     
    4. The apparatus for bending a glass sheet (18) according to any one of claims 1 to 3, which produces a glass sheet (18) to be used as a window glass of an automobile
     
    5. The apparatus for bending a glass sheet (18) according to any one of claims 1 to 4, wherein said curved rollers (12A - 12M) are arranged in a cooling zone.
     


    Ansprüche

    1. Vorrichtung zum Biegen einer Glasscheibe (18), die umfasst: einen Heizofen (16), um eine Glasscheibe (18) auf eine Biegetemperatur zu heizen, eine Rollenbahn (13) mit einer Vielzahl von Rollen (12A - 12M), um die geheizte Glasscheibe (18) entlang einer von den Rollen (12A - 12M) definierten Förderebene zu befördern, wobei die Rollen (12A - 12M) entsprechend der Position der Glasscheibe (18) nach oben und unten beweglich sind, so dass ein Teil der Förderebene in Bezug auf die Förderrichtung der Glasscheibe (18) gebogen wird, um dadurch die Glasscheibe (18) sich durch ihr Eigengewicht biegen zu lassen, so dass sie eine gewünschte Krümmung hat;
    wobei die Rollen (12A - 12M) gekrümmte Rollen (12A - 12M) sind, wobei die gekrümmten Rollen (12A - 12M) jeweils eine Führungswelle (70) haben, die ausgebildet ist, so dass sie eine gewünschte Krümmung hat, und wobei eine Vielzahl von Ringwalzen (72) drehbar auf die Führungswelle (70) montiert sind, so dass sie sich um die axiale Mitte der Führungswelle (70) drehen,
    wobei Drehantriebsmittel zum Drehen eines Außenzylinders (194), der das Ende (70A) der Führungswelle (70) bedeckt, an einem Ende (70A) oder an beiden Enden (70A) der Führungswelle (70) bereitgestellt sind, und
    wobei Antriebsmittel zum Bewegen des Außenzylinders (194) und der Führungswelle (70) nach oben und unten an einem Ende (70A) oder an beiden Enden (70A) der Führungsrolle (70) bereitgestellt sind, so dass der Außenzylinder (194) und die Führungswelle (70) durch den Betrieb der Antriebsmittel biegbar sind, um die durch die Vielzahl von Ringwalzen (72) definierte Förderebene zu biegen.
     
    2. Vorrichtung zum Biegen einer Glasscheibe (18) nach Anspruch 1,
    dadurch gekennzeichnet, dass jede der gekrümmten Rollen (12A - 12M) eine Führungswelle (70) hat, die durch eine elastische Verformung biegbar ist,
    eine Hohlwalzenstruktur (192) drehbar auf die Führungswelle (70) montiert ist und eine kürzere Länge als die Gesamtlänge der Führungswelle (70) hat,
    der erste Außenzylinder (194) ein Ende (70A) der Führungswelle (70), das von der Hohlwalzenstruktur (192) vorsteht, bedeckt, und
    ein zweiter Außenzylinder (194) das andere Ende (70A) der Führungswelle (70), das von der Hohlwalzenstruktur (192) vorsteht, bedeckt,
    wobei ein Ende jedes der ersten und zweiten Außenzylinder (194) mit dem jeweiligen Ende der Hohlwalzenstruktur (192) verbunden ist und von einem Halteelement (198) auf einem Untersatz (200) über ein Lager (196) gehalten wird,
    wobei das andere Ende des ersten und/oder zweiten Außenzylinders (194) über einen Hebemechanismus von dem Untersatz (200) gehalten wird, das andere Ende des ersten und/oder zweiten Außenzylinders (194) mit einem vorgegebenen Drehantriebsmittel verbunden ist, so dass ein Drehmoment übertragen werden kann, wodurch
    die Führungswelle (70) und die Hohlwalzenstruktur (192) durch Erhöhen des anderen Endes des ersten und/oder zweiten Außenzylinders (194) um das Halteelement (1098) als einen Drehpunkt durch den Hebemechanismus gekrümmt werden, und die von der Hohlwalzenstruktur definierte Förderebene gekrümmt wird.
     
    3. Vorrichtung zum Biegen einer Glasscheibe (18) nach Anspruch 2, wobei die Hohlwalzenstruktur (192) von einer Vielzahl von Ringwalzen (72), in die die Welle (70) eingesetzt ist, und eine Vielzahl von flexiblen rohrförmigen Gliedern zum Verbinden der Ringwalzen (72) miteinander gebildet wird.
     
    4. Vorrichtung zum Biegen einer Glasscheibe (18) nach einem der Ansprüche 1 bis 3, die eine Glasscheibe herstellt, die als ein Fensterglas eines Autos verwendet werden soll.
     
    5. Vorrichtung zum Biegen einer Glasscheibe (18) nach einem der Ansprüche 1 bis 4, wobei die gekrümmten Rollen (12A - 12M) in einer Kühlzone angeordnet sind.
     


    Revendications

    1. Un appareil pour cintrer une feuille de verre (18), comprenant un four de chauffe (16) pour chauffer une feuille de verre (18) à une température de cintrage, et un transporteur à rouleaux (13) ayant une pluralité de rouleaux (12A - 12M) pour transporter la feuille de verre chauffée (18) le long d'un plan de transport défini par les rouleaux (12A - 12M), lesdits rouleaux (12A - 12M) étant capables de se mouvoir vers le haut et vers le bas selon la position de la feuille de verre (18), pour avoir une partie du plan de transport incurvée par rapport à la direction de transport du la feuille de verre (18), permettant ainsi à la feuille de verre (18) de se courber sous son propre poids afin d'avoir la courbure souhaitée ;
    dans laquelle lesdits rouleaux (12A - 12M) sont des rouleaux courbés (12A - 12M),
    dans laquelle lesdits rouleaux courbés (12A - 12M) ont chacun un arbre de guidage (70) formé pour avoir une courbure souhaitée, et une pluralité de rouleaux annulaires (72) montés de manière rotative sur l'arbre de guidage (70) de manière à ce qu'ils tournent autour du centre axial de l'arbre de guidage (70),
    dans laquelle des moyens d'entraînement rotatifs pour mettre en rotation un cylindre extérieur (194) couvrant l'extrémité (70A) de l'arbre de guidage sont prévus à une extrémité (70A) ou aux deux extrémités (70A) de l'arbre de guidage (70), et
    dans laquelle les moyens d'entrainement destinés à mouvoir le cylindre extérieur (194) et l'arbre de guidage (70) vers le haut et vers le bas sont prévus à une extrémité (70A) ou aux deux extrémités (70A) de l'arbre de guidage (70), de sorte que la cylindre extérieur (194) et l'arbre de guidage (70) puissent être courbés par l'action des moyens d'entraînement, de manière à incurver le plan de transport défini par la pluralité de rouleaux annulaires (72).
     
    2. L'appareil pour le cintrage d'une feuille de verre (18) selon la revendication 1, caractérisé en ce que chacun desdits rouleaux courbés (12A - 12M) a un arbre de guidage (70) cintrable par une déformation élastique, une structure de rouleaux creux (192) fixée de manière rotative audit arbre de guidage (70), et ayant une longueur plus courte que la longueur totale dudit arbre de guidage (70),
    un premier cylindre extérieur (194) couvrant une extrémité (70A) dudit arbre de guidage (70) en saillie par rapport à ladite structure de rouleaux creux (192), et
    un second cylindre extérieur (194) couvrant l'autre extrémité (70A) dudit arbre de guidage (70) en saillie par rapport à ladite structure de rouleaux creux (192),
    dans laquelle une extrémité de chacun desdits cylindres extérieurs (194) est connectée à l'extrémité respective de ladite structure de rouleaux creux (192), et soutenue par un élément de support (198) sur un montant (200) par l'intermédiaire d'un palier (196), l'autre extrémité dudit premier et/ou second cylindre extérieur (194) est soutenue par ledit montant (200) au moyen d'un mécanisme élévateur, ladite autre extrémité dudit premier et/ou second cylindre extérieur (194) est connecté à un dispositif d'entraînement rotatif de manière à pouvoir transmettre un couple, par lequel
    ledit arbre de guidage (70) et ladite structure de rouleaux creux (192) sont cintrés par une élévation de l'autre extrémité dudit premier et/ou second cylindre extérieur (194) autour dudit élément de support (198) en tant que point pivot par ledit mécanisme élévateur, et le plan de transport défini par ladite structure de rouleaux creux est cintré.
     
    3. L'appareil pour le cintrage d'une feuille de verre (18) selon la revendication 2, dans lequel ladite structure de rouleaux creux (192) est constituée d'une pluralité de rouleaux annulaires (72) dans lesquels est inséré ledit arbre (70), et d'une pluralité d'éléments tubulaires flexibles destinés à relier les rouleaux annulaires (72) l'un à l'autre.
     
    4. L'appareil pour le cintrage d'une feuille de verre (18) selon l'une quelconque des revendications 1 à 3, qui produit une feuille de verre (18) à utiliser comme une vitre pour automobile.
     
    5. L'appareil pour le cintrage d'une feuille de verre (18) selon l'une quelconque des revendications 1 à 4, dans lequel lesdits rouleaux courbés (12A - 12M) sont disposés dans une zone de refroidissement.
     




    Drawing















































    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description