Edge detection device and method for manufacturing pneumatic tire

Abstract

The present invention provides an edge detection device and a method for manufacturing a pneumatic tire, wherein the edge detection device (22) is capable of detecting the position of an edge (36) of a sheet (26). The edge detection device (22) comprises: a line camera (38) that captures an image of a composite sheet (24) in the width direction, the composite sheet (24) being formed by laminating at least two sheets (26), the positions of the edges (36) of the at least two sheets (26) being offset in the width direction; and a pair of lighting units (40) that irradiate light onto the composite sheet (24). In the length direction of the composite sheet 24, the pair of lighting units 40 are arranged across the line camera (38), and the portion irradiated by the light of one lighting unit (40) is irradiated by the light of another lighting unit (40). The field of view of the line camera (38) includes the edge (36) of another sheet (26) located on one sheet (26).

Description

Technical Field

[0001] The present invention relates to an edge detection device. Specifically, the present invention relates to an edge detection device that detects an edge of another sheet located on one sheet in a composite sheet formed by laminating at least two sheets, wherein the positions of the edges of the at least two sheets are offset in the width direction. The present invention also relates to a method for manufacturing a pneumatic tire including an inner liner and a chafer. Background Art

[0002] Fig.12 Indicates the bead portion 4 of the tire 2. In the bead portion 4, the edge 8 that contacts the flange of the rim is located axially outside the bead 6. The edge 8 is composed of cross-linked rubber. The bead filler 10 that contacts the rim seat is located radially inside the bead 6. The bead filler 10 is composed of cloth and rubber impregnated in the cloth. The inner liner 12 that forms the inner surface of the tire 2 is located axially inside the bead 6. The inner liner 12 is composed of cross-linked rubber. The isolation layer 16 is located between the inner liner 12 and the carcass 14. The isolation layer 16 is composed of cross-linked rubber.

[0003] Although not described in detail, in the manufacture of the tire 2, the beads 6, the carcass 14 and other components are combined to form an unvulcanized tire (hereinafter also referred to as a green tire). The tire 2 is obtained by vulcanizing the green tire.

[0004] In the molding of the green tire, the chafer 10, the inner liner 12, and the separator 16 molded in a sheet shape are combined to prepare a composite sheet (hereinafter also referred to as a composite lining).

[0005] Fig.13 A cross section of a composite lining 18 is shown. Fig.13 In the figure, the left-right direction is the width direction of the composite lining sheet 18. The direction perpendicular to the paper surface is the length direction of the composite lining sheet 18.

[0006] Fig.13 The composite lining 18 shown is composed of a pair of chafers 10, an inner liner 12, and an isolation layer 16. In the composite lining 18, the width of the inner liner 12 is narrower than the width of the isolation layer 16, and the inner liner 12 is entirely laminated on the isolation layer 16. The pair of chafers 10 are respectively laminated on the isolation layer 16 protruding outward from the inner liner 12 in the width direction.

[0007] Fig.14 An example of a method for forming the composite lining 18 is shown. Fig.14 As shown, the inner liner 12 is attached to the separator 16, and the chafer 10 is attached to the separator 16 protruding from the inner liner 12. The separator 16, the inner liner 12, and the pair of chafers 10 are pressed together by a roller 20. Thus, the composite lining 18 is obtained.

[0008] The positions of the edges of the isolation layer 16, the inner liner 12 and the chafer 10 in the composite lining 18 affect Fig.12 The positions of the edges of the components in the cross section of the tire 2 are shown. Therefore, development of a device capable of grasping the width of a sheet and the position of the edge of the sheet is underway (for example, Patent Document 1 listed below).

[0009] For example, the following Patent Document 2 describes a method for manufacturing a pneumatic tire, which includes a composite lining forming step, wherein a composite lining is formed by combining an unvulcanized sheet-like inner liner and a sheet-like chafer with an inner liner layer and an isolation layer. The composite lining forming step includes a joining step of splicing sheet-like chafers at both side edges of the sheet-like inner liner in the tire axial direction.

[0010] Patent Document 1: Japanese Patent Application Publication No. 2001-201335

[0011] Patent Document 2: Japanese Patent Application Publication No. 2015-541 Summary of the invention

[0012] The rubber used for the components of the tire 2 contains carbon black. Therefore, the color of each component constituting the tire 2 is black. Since the sheets of the same black color are stacked, it is not easy to detect the edge of the sheets.

[0013] If the sheet has a certain thickness, the edge of the sheet can be detected by using a displacement sensor, for example. However, from the viewpoint of weight reduction, when a thin sheet is used as a component of the tire 2, it is difficult to detect the edge using a displacement sensor.

[0014] Furthermore, Patent Document 2 mentioned above does not examine the case of overlapping the sheet-like chafer and the sheet-like inner liner with high accuracy.

[0015] The present invention is made in view of such actual situation, and its object is to provide an edge detection device capable of detecting the edge position of a sheet. In addition, the present invention is to provide a method for manufacturing a pneumatic tire, which can form a composite lining formed by overlapping a sheet-like chafer and a sheet-like inner liner with high precision.

[0016] An edge detection device according to one embodiment of the present invention detects the edge of another sheet located on one sheet in a composite sheet formed by laminating at least two sheets, wherein the positions of the edges of the at least two sheets are offset in the width direction, and the edge detection device comprises: a line camera that captures an image of the composite sheet in the width direction; and a pair of lighting units that irradiate light to the composite sheet. In the length direction of the composite sheet, the pair of lighting units are arranged across the line camera, and the portion irradiated by the light of one lighting unit is irradiated with the light of the other lighting unit. The edge of the other sheet located on the one sheet is included in the field of view of the line camera.

[0017] Preferably, in the edge detection device, the line camera captures an image in the width direction of the composite sheet located directly therebelow.

[0018] Preferably, in the edge detection device, an angle formed by the direction of light from the one illumination unit with respect to the optical axis of the line camera is the same as an angle formed by the direction of light from the other illumination unit with respect to the optical axis of the line camera.

[0019] Preferably, the edge detection device has a conveying unit for conveying the composite sheet in a length direction of the composite sheet.

[0020] One embodiment of the present invention is a method for manufacturing a pneumatic tire, which includes an innerliner and a pair of chafers arranged at both ends of the innerliner in the tire axial direction, the method for manufacturing the pneumatic tire includes a composite lining forming process for forming a composite lining, the composite lining is composited by an unvulcanized sheet-like innerliner and a pair of unvulcanized sheet-like chafers, the composite lining forming process includes: an innerliner forming step, forming the sheet-like innerliner by overlapping a first rubber sheet with a second rubber sheet wider than the first rubber sheet; a detection step, detecting the two ends of the first rubber sheet; and a pasting step, pasting the sheet-like innerliner to each of the sheet-like chafers based on the detected positions of the two ends of the first rubber sheet.

[0021] Preferably, in the method for manufacturing a pneumatic tire, in the detecting step, an imaging unit for imaging both ends of the first rubber sheet is used.

[0022] Preferably, in the method for manufacturing a pneumatic tire, the second rubber sheet of the sheet-like inner liner extends to an outer side than both ends of the first rubber sheet.

[0023] Preferably, in the method for manufacturing a pneumatic tire, in the attaching step, the second rubber sheet and each of the sheet-like chafers are overlapped at positions outside both ends of the first rubber sheet.

[0024] Effects of the Invention

[0025] The edge detection device of the present invention can detect the edge position of the sheet. The edge detection device can help manufacture high-quality tires. In the manufacturing method of the pneumatic tire of the present invention, the overlapping position of the sheet inner liner and the pair of sheet chafers is positioned based on the two ends of the first rubber sheet detected in the detection step. As a result, the manufacturing method of the pneumatic tire of the present invention can form a composite lining formed by compounding the sheet inner liner and the sheet chafers with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a front view schematically showing an edge detection device according to one embodiment of the present invention.

[0027] Figure 2 is a top view of the edge detection device.

[0028] Figure 3 It is the image captured by the edge detection device.

[0029] Figure 4 It is a cross-sectional view showing the right half of an example of a pneumatic tire formed by the manufacturing method of the present invention.

[0030] Figure 5 is a cross-sectional view of a composite lining.

[0031] Figure 6 (a) is a side view conceptually showing a lining forming step, Figure 6 (b) is a cross-sectional view of the sheet lining.

[0032] Figure 7 This is a three-dimensional diagram conceptually showing the detection step and the attachment step.

[0033] Figure 8 (a) is a top view conceptually showing the conveying state of the sheet-like chafer. Figure 8 (b) is Figure 8 (a) AA line cross-sectional view.

[0034] Fig. 9 (a) is a cross-sectional view conceptually showing the composite lining winding process. Fig. 9 (b) is a cross-sectional view conceptually showing the carcass ply winding process and the bead core installation process, Fig. 9 (c) is a cross-sectional view conceptually showing the molding process.

[0035] Fig.10 It is a perspective view showing a modified example of the manufacturing apparatus.

[0036] Fig.11(a) is a graph showing the accuracy of the composite lining manufactured by the manufacturing method of this embodiment, Fig.11 (b) is a graph showing the accuracy of the composite lining produced by the production method of the comparative example.

[0037] Fig.12 It is a cross-sectional view showing a bead portion of a tire.

[0038] Fig.13 It is a cross-sectional view showing a composite sheet composed of a plurality of sheets.

[0039] Fig.14 It is a perspective view for explaining a conventional method for forming a composite sheet.

[0040] Description of symbols

[0041] 2: tire; 4: bead portion; 10: bead packing cloth; 12: inner liner; 16: isolation layer; 18: composite lining; 22, 222: detection device; 24: composite sheet; 26: sheet; 28: first sheet; 30: second sheet; 32: edge of first sheet 28; 34: edge of second sheet 30; 36: edge of sheet 26; 38, 238: line camera; 40, 240: lighting unit; 42, 242: control unit; 44 , 244: first lighting unit; 46, 246: second lighting unit; 50: analysis unit; 52: conveying unit; 101: pneumatic tire; 111N: sheet liner; 112N: sheet chafer; 113: composite lining; 114: first rubber sheet; 115: second rubber sheet; 114e: end of first rubber sheet 114; S1: composite lining forming process; s1: lining forming step; s2: output step; s3: pasting step. DETAILED DESCRIPTION

[0042] Hereinafter, the present invention will be described in detail based on preferred embodiments, with appropriate reference to the drawings.

[0043] [First embodiment: edge detection device]

[0044] Figure 1 and Figure 2 The following is an overview of an edge detection device 22 according to an embodiment of the present invention. The edge detection device 22 is a device for detecting an edge of another sheet located on a composite sheet 24 formed by laminating at least two sheets, the edges of the at least two sheets being offset in the width direction.

[0045] exist Figure 1 In the figure, the left-right direction is the length direction of the composite sheet 24. The direction perpendicular to the paper surface is the width direction of the composite sheet 24. Figure 2In the figure, the left-right direction is the length direction of the composite sheet 24 , and the up-down direction is the width direction of the composite sheet 24 .

[0046]

Composite sheet 24

[0047] Figure 1 and Figure 2 The composite sheet 24 shown is composed of two sheets 26 of different widths. In the composite sheet 24, a first sheet 28 of narrow width is stacked on a second sheet 30 of wide width.

[0048] like Figure 2 As shown, in the composite sheet 24, in the width direction, the edge 32 of the first sheet 28 is located inside the edge 34 of the second sheet 30. In other words, the edge 32 of the first sheet 28 is configured to be offset inward in the width direction from the edge 34 of the second sheet 30. The composite sheet 24 is formed by laminating two sheets 26, the edge 32 of the first sheet 28 is located on the second sheet 30, and the positions of the edges 36 of the two sheets 26 are staggered in the width direction.

[0049] The sheet 26 forming the composite sheet 24 is obtained by processing unvulcanized rubber into a sheet shape using a molding machine such as a calendar roll. The sheet 26 forming the composite sheet 24 may be a rubber-coated cord member (not shown) composed of a plurality of parallel cords and rubber covering the cords.

[0050] The rubber in the unvulcanized state (hereinafter also referred to as unvulcanized rubber) is obtained by mixing the base rubber and chemicals using a mixer such as a Banbury mixer. As the base rubber, natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), isoprene rubber (IR), ethylene propylene rubber (EPDM), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR) and butyl rubber (IIR) can be exemplified. As chemicals, reinforcing agents such as carbon black or silica, plasticizers such as aromatic oils, fillers such as zinc oxide, lubricants such as stearic acid, antioxidants, processing aids, sulfur and vulcanization accelerators can be exemplified. The selection of base rubber and chemicals, the content of the selected chemicals, etc. are appropriately determined according to the specifications of the components to which the rubber is applied.

[0051] exist Figure 1 and Figure 2 In the composite sheet 24 shown, the first sheet 28 is Fig.13 The inner lining layer 12 in the composite lining sheet 18 shown. The second sheet 30 is the Fig.13 The insulating layer 16 in the composite lining 18 is shown. The chafer 10 as the third sheet is attached to the second sheet 30 exposed from the first sheet 28, thereby obtaining Figure 4The composite lining 18 shown. The composite sheet 24 obtained by laminating the narrow first sheet 28 as the inner liner 12 to the wide second sheet 30 as the isolation layer 16 is also called an inner liner. The composite lining 18 is a composite sheet obtained by laminating the chafer 10 to the inner liner.

[0052] In the composite sheet 24, the first sheet 28 and the second sheet 30 have the same color. The unvulcanized rubber used for the first sheet 28 and the unvulcanized rubber used for the second sheet 30 include carbon black. The colors of the first sheet 28 and the second sheet 30 are black.

[0053] [Edge detection device 22]

[0054] The edge detection device 22 is part of the production line (also referred to as a manufacturing device) of the tire 2. Although not shown in the figure, in the production line, the edge detection device 22 is located on the downstream side of the molding machine that forms the composite sheet 24 by bonding the first sheet 28 and the second sheet 30 together. The edge detection device 22 is located on the downstream side of the molding machine that forms the composite sheet 24 by bonding the two third sheets to the composite sheet 24. Figure 4 The composite lining 18 is shown on the upstream side of the forming machine. Figure 1 and Figure 2 In the figure, the left side of the paper is the upstream side of the edge detection device 22, and the right side of the paper is the downstream side of the edge detection device 22.

[0055] The edge detection device 22 (hereinafter also referred to as the device 22 ) includes a line camera 38 , a pair of lighting units 40 , and a control unit 42 .

[0056] The line camera 38 is located above the composite sheet 24. In the device 22, the line camera 38 captures an image of the composite sheet 24 located directly below it. The line camera 38 is not two-dimensional like an area camera, but has light receiving elements arranged in a linear shape. The line camera 38 captures an image in the width direction of the composite sheet 24. As the line camera 38, for example, the trade name "XG-X series line camera" manufactured by KEYENCE can be cited.

[0057] A pair of lighting units 40 are arranged across the line camera 38 in the longitudinal direction of the composite sheet 24. Each lighting unit 40 irradiates light toward the composite sheet 24. In the device 22, the lighting unit 40 located on the upstream side is the first lighting unit 44, and the lighting unit 40 located on the downstream side is the second lighting unit 46.

[0058] As the lighting unit 40, area lighting and line lighting can be cited. Line lighting is preferred from the viewpoint of being able to uniformly irradiate the composite sheet 24 linearly along the width direction. As the light source used in the lighting unit 40, it is preferred to use a light source that can irradiate light with high directivity. As such a light source, an LED light source can be cited. As the lighting unit 40 of the device 22, line lighting formed by arranging a plurality of LED light sources in a straight line is more preferred.

[0059] The control unit 42 is composed of, for example, a microcomputer having a computing unit such as a CPU, a storage unit including a RAM and a ROM, and the computing unit executes a program stored in the storage unit to perform a predetermined function. In the device 22, the elements constituting the device 22 such as the line camera 38 are connected to the control unit 42 via a communication cable 48. Although not described in detail, the control unit 42 controls the operation of these elements.

[0060] In the device 22, a line camera 38 captures an image of the entire width direction of the composite sheet 24. The field of view of the line camera 38 includes the edge 32 of the first sheet 28 located on the second sheet 30.

[0061] In the device 22, the lighting units 40 located on both sides of the line camera 38 irradiate light onto the composite sheet 24. The light of the second lighting unit 46 is irradiated onto the portion irradiated with light from the first lighting unit 44. Alternatively, the light of the first lighting unit 44 may be irradiated onto the portion irradiated with light from the second lighting unit 46. The line camera 38 captures images of the portion irradiated with light from the two lighting units 40.

[0062] Figure 3 38 shows a portion of an image captured by the line camera 38 of the device 22. In the device 22, an image reflecting the surface state of the composite sheet 24, in particular, an image reflecting the contrast difference at the boundary between the first sheet 28 and the second sheet 30 is captured. Figure 3 As shown, the edge 32 of the first sheet 28 located on the second sheet 30 is clearly shown in this image.

[0063] In the device 22, the image captured by the line camera 38 is input as data to the control unit 42. In the control unit 42, the data is analyzed by a known program for image processing pre-stored in the storage unit. Thus, the position of the edge 32 of the first sheet 28 extending in the length direction of the composite sheet 24 is detected. In the device 22, the control unit 42 has a function as an analysis unit 50 that analyzes the data of the image captured by the line camera 38. The device 22 has the analysis unit 50 that analyzes the data of the image captured by the line camera 38.

[0064] In the apparatus 22, although the first sheet 28 and the second sheet 30 are the same color and appear black, the edge 32 of the first sheet 28 located on the second sheet 30 is clearly shown in the image captured by the line camera 38. Based on the image showing the edge 36, the position of the edge 36 of the sheet 26 is detected.

[0065] As described above, in the molding machine located on the downstream side, two third sheets are bonded to the composite sheet 24 to form a Figure 5 The composite lining 18 shown in FIG. 1 is a composite lining 18. By reflecting the position data of the detected edge 36 in the action program for forming the composite lining 18, the molding machine can correctly attach the third sheet to the correct position. The device 22 can also confirm the width of the first sheet 28 stacked on the second sheet 30 based on the position data of the detected edge 36. The device 22 can contribute to the manufacture of high-quality tires 2.

[0066] exist Figure 1 In FIG. 1 , the dotted line AL is the optical axis of the line camera 38. The optical axis AL extends perpendicularly to the length direction of the composite sheet 24. The solid line L1 is the direction of the light of the first lighting unit 44, and the solid line L2 is the direction of the light of the second lighting unit 46. The direction of the light of the lighting unit 40 is adjusted by the direction of the lighting unit 40 relative to the composite sheet 24.

[0067] exist Figure 1 In , the angle α is the angle formed by the direction L1 of the light of the first lighting unit 44 with respect to the optical axis AL of the line camera 38 . The angle β is the angle formed by the direction L2 of the light of the second lighting unit 46 with respect to the optical axis AL of the line camera 38 .

[0068] In the device 22, the angle α formed by the direction L1 of the light of the first lighting unit 44 with respect to the optical axis AL of the line camera 38 is the same as the angle β formed by the direction L2 of the light of the second lighting unit 46 with respect to the optical axis AL of the line camera 38. In the device 22, since an image reflecting the surface state of the composite sheet 24 is captured, the edge 32 of the first sheet 28 located on the second sheet 30 is more clearly displayed. Since an image showing the edge 36 more clearly is obtained, the device 22 can reliably detect the position of the edge 36 of the sheet 26. From this viewpoint, in the device 22, it is preferable that the angle α formed by the direction L1 of the light of the first lighting unit 44 with respect to the optical axis AL of the line camera 38 is the same as the angle β formed by the direction L2 of the light of the second lighting unit 46 with respect to the optical axis AL of the line camera 38. In addition, in the device 22, when the difference between the angle α and the angle β is within the range of -3° or more and 3° or less, it is determined that the angle α and the angle β are the same.

[0069] In the device 22, from the viewpoint of obtaining an image showing the edge 36 more clearly, the angle α formed by the direction L1 of the light of the first lighting unit 44 with respect to the optical axis AL of the line camera 38 is preferably 30° or more and preferably 60° or less. From the same viewpoint, the angle β formed by the direction L2 of the light of the second lighting unit 46 with respect to the optical axis AL of the line camera 38 is preferably 30° or more and preferably 60° or less. In the device 22, it is more preferable that the angle α formed by the direction L1 of the light of the first lighting unit 44 with respect to the optical axis AL of the line camera 38 is 30° or more and 60° or less, the angle β formed by the direction L2 of the light of the second lighting unit 46 with respect to the optical axis AL of the line camera 38 is 30° or more and 60° or less, and the angle α and the angle β are the same.

[0070] The device 22 may include a conveying unit 52 for conveying the composite sheet 24 in the length direction of the composite sheet 24. The device 22 including the conveying unit 52 may continuously or intermittently capture an image of the composite sheet 24 in the width direction while conveying the composite sheet 24. The device 22 may detect the position of the edge 36 of the sheet 26 over the entire length direction of the composite sheet 24. The device 22 contributes to the manufacture of high-quality tires 2. From this viewpoint, the device 22 preferably includes a conveying unit 52 for conveying the composite sheet 24 in the length direction of the composite sheet 24.

[0071] exist Figure 1 and Figure 2 In the device 22 shown, a roller conveyor is used as the conveying unit 52. In the device 22, the conveying unit 52 is not limited to the roller conveyor. For example, a belt conveyor may be used as the conveying unit 52.

[0072] As described above, the edge detection device 22 of the present invention can detect the position of the edge 36 of the sheet 26. The edge detection device 22 can contribute to the manufacture of a high-quality tire 2.

[0073] [Second embodiment: Method for manufacturing a pneumatic tire]

[0074] Figure 4 1 is a cross-sectional view showing an embodiment of a pneumatic tire (hereinafter sometimes simply referred to as a "tire") 101 formed by the manufacturing method of the present invention. Figure 4 2 shows a tire 101 for a passenger car, for example. The present invention can also be applied to other types of tires such as tires for motorcycles or heavy loads.

[0075] like Figure 4 As shown, the tire 101 of the present embodiment includes a carcass 106, an air-impermeable inner liner 111, and a chafer 112 for preventing rim displacement.

[0076] The carcass 106 of this embodiment extends from the tread portion 102 through the sidewall portion 103 to the bead core 105 of the bead portion 104. The carcass 106 is composed of, for example, a carcass ply 106A in which carcass cords are arranged. In this embodiment, the carcass ply 106A includes a main body 106a extending between the bead cores 105 on both sides, and a pair of folded portions 106b connected to the main body 106a and folded around the bead core 105 from the inner side to the outer side of the tire axial direction. In addition, the carcass 106 is not limited to such a method, and various known methods can be used.

[0077] A tread reinforcing layer 107 including, for example, a belt layer 107a or a cap layer 107b and a tread rubber 102G forming the outer surface of the tread portion 102 are arranged on the tire radially outer side of the carcass 106. A bead apex rubber 108 made of hard rubber is arranged between the main body portion 106a and the return portion 106b. The tread reinforcing layer 107, the tread rubber 102G and the bead apex rubber 108 can adopt various well-known methods.

[0078] The inner liner 111 is, for example, arranged on the inner side of the carcass 106 in the tire radial direction to form the inner cavity surface 101S of the tire 101. In the present embodiment, the inner liner 111 is formed of a double-layer structure of an inner layer portion 111a (also referred to as an inner liner layer) along the inner cavity surface 101S and an outer layer portion 111b (also referred to as an isolation layer) arranged on the outer side of the inner layer portion 111a.

[0079] The inner layer 111a is composed of, for example, a first rubber G1 of a non-air-permeable butyl rubber system. In the present embodiment, the first rubber G1 is butyl rubber, a halogenated butyl rubber as a derivative thereof, and a mixed rubber containing 60% by mass or more of butyl rubber or halogenated butyl rubber in the rubber component. In the case of a mixed rubber, the remaining rubber is preferably a diene rubber such as NR (natural rubber), SBR (styrene butadiene rubber), BR (butadiene rubber), IR (isoprene rubber), etc.

[0080] The outer layer 111b is composed of, for example, a second rubber G2 of NR type having excellent adhesiveness. Such an outer layer 111b can improve the adhesive strength between the inner layer 111a and the carcass 106. In the present embodiment, the second rubber G2 is a mixed rubber of NR and a rubber component containing 60% by mass or more of butyl rubber or halogenated butyl rubber. In the case of a mixed rubber, the remaining rubber is preferably a diene rubber such as SBR, BR, or IR.

[0081] The bead chafer 112 is, for example, a rubber sheet-shaped member reinforced by a fiber material. In the present embodiment, the bead chafer 112 is formed as a canvas bead chafer formed by rubber coating a canvas composed of organic fibers such as aramid, nylon, and rayon. In addition, the bead chafer 112 is not limited to such a form, and may also be a known structure formed by rubber coating a cord array body.

[0082] The tire chafer 112 is formed, for example, by a base portion 112a, an inner portion 112b and an outer portion 112c. In the present embodiment, the base portion 112a extends along the tire bead bottom surface 104S. In the present embodiment, the inner portion 112b is bent toward the inner side of the tire axial direction of the base portion 112a and extends along the inner cavity surface 101S. In the present embodiment, the outer end of the inner portion 112b is butted against the inner end of the inner layer portion 111a of the inner liner 111. In the present embodiment, the outer portion 112c is bent toward the outer side of the tire axial direction of the base portion 112a and extends along the return portion 106b.

[0083] Next, a method for manufacturing the tire 101 is described. In the manufacturing method of this embodiment, Figure 5 As shown, the composite lining forming step S1 of forming the composite lining 113 is included. The composite lining 113 is obtained by compounding an unvulcanized sheet-like inner liner 111N with a pair of unvulcanized sheet-like chafers 112N, 112N.

[0084] In the present embodiment, the composite lining forming process S1 includes a lining forming step s1 , a detection step s2 , and a pasting step s3 .

[0085] like Figure 6 As shown in (a), in the liner forming step s1, a first rubber sheet 114 is overlapped with a second rubber sheet 115 having a width wider than the first rubber sheet 114 to form a sheet-shaped liner 111N. The first rubber sheet 114 is obtained, for example, by calendering the first rubber G1 using a known calendering unit 116. The second rubber sheet 115 is obtained, for example, by calendering the second rubber G2 using a known calendering unit 116.

[0086] In this embodiment, the first rubber sheet 114 and the second rubber sheet 115 are overlapped on a conveying roller 117 of a known structure, thereby forming a sheet-shaped liner 111N. Figure 6 As shown in (b) of FIG. 1 , the sheet-like inner liner 111N includes a protrusion 118 where the second rubber sheet 115 protrudes from the first rubber sheet 114. In the present embodiment, the protrusion 118 is disposed at both ends of the second rubber sheet 115 in the width direction.

[0087] The sheet liner 111N is cooled, for example, by a known cooling drum 119. The cooled sheet liner 111N may be temporarily wound into a roll and then conveyed to the next inspection step s2, or may be conveyed to the inspection step s2 while remaining in a sheet shape.

[0088] Next, the detection step s2 and the pasting step s3 are performed. In the detection step s2, the two ends 114e, 114e of the first rubber sheet 114 of the sheet-like inner liner 111N are detected. In the pasting step s3, based on the positions of the detected two ends 114e, 114e, the sheet-like chafer 112N is pasted on the sheet-like inner liner 111N to form the composite lining 113. Figure 7 is a three-dimensional diagram conceptually showing the detection step s2 and the pasting step s3. Figure 7 As shown, in this embodiment, the sheet liner 111N is transported by a known conveyor 120 with the second rubber sheet 115 located at the bottom and the first rubber sheet 114 located at the top. In addition, a known forming drum 132 ( Figure 6 The composite lining 113 conveyed by the conveyor 120 is wound on the forming drum 132.

[0089] In this specification, the conveying direction (length direction) of the sheet liner 111N is indicated by arrow Y. In addition, the vertical (up and down) direction perpendicular to arrow Y is indicated by arrow Z. In addition, the width direction of the sheet liner 111N perpendicular to arrows Y and Z is indicated by arrow X. The width direction X is, for example, a horizontal direction.

[0090] In the detection step s2 and the pasting step s3 of the present embodiment, both ends 114e ( Figure 6 The detection device 121 and the pasting device 122 for pasting the sheet-like inner liner 111N and the sheet-like chafer 112N are shown in (b). The detection device 121 and the pasting device 122 constitute a part of the manufacturing device 133 of the tire 101. The manufacturing device 133 of the tire 101 has the detection device 121 and the pasting device 122.

[0091] The detection device 121 includes, for example, a photographing unit 123 and a control unit 124 .

[0092] The imaging unit 123, for example, images the two ends 114e, 114e of the first rubber sheet 114, obtains image data thereof, and outputs an electrical signal corresponding to the positions of the two ends 114e, 114e to the control unit 124. As such an imaging unit 123, for example, a camera or a video camera is preferable, and a CCD camera such as a line scan camera of a layer processing system (XG-X series) manufactured by KEYENCE Corporation is particularly preferable. The CCD camera can detect the positions of the two ends 114e, 114e of the black first rubber sheet 114 arranged on the black second rubber sheet 115 with high accuracy by using the overlapping shadows of the rubber sheets. In the present embodiment, the imaging unit 123 includes two CCD cameras. These CCD cameras are arranged to be spaced apart in the width direction X. In addition, the detection device 121 may include a known distance measuring unit (not shown) such as a laser displacement meter instead of the imaging unit 123, and the distance measuring unit may detect the two ends 114e, 114e.

[0093] The control unit 124 controls the sticking device 122 based on the electric signal from the imaging unit 123. Thus, the sheet-like inner liner 111N and the sheet-like chafer 112N can be stuck together with high accuracy.

[0094] The control unit 124 includes, for example, a computing unit composed of a CPU (central processing unit), a storage unit that stores control steps and programs in advance, and a work memory (not shown) that reads the control steps from the storage unit. The control unit 124 may also be provided with a display unit for displaying processing results, etc., and an operation unit for an operator to operate. As such a control unit 124, for example, a known programmable sequencer, a microcomputer, a personal computer, etc. are preferably used.

[0095] In this embodiment, the sticking device 122 includes an applicator 125 and a pressing roller 126 .

[0096] The applicator 125 is used to supply the sheet-like chafer 112N to the sheet-like inner liner 111N on the conveyor 120. The applicator 125 includes, for example, a guide portion 127 that guides the sheet-like chafer 112N onto the conveyor 120 and a moving tool 128 that moves the guide portion 127. The applicator 125 includes, for example, a conveying roller (not shown), thereby conveying the sheet-like chafer 112N on the guide portion 127.

[0097] like Figure 8As shown in (a) and (b), the guide portion 127 includes, for example, a carrier sheet 127a, a first upright sheet 127b, and a second upright sheet 127c. In the present embodiment, the carrier sheet 127a carries a sheet-like chafer 112N. In the present embodiment, the first upright sheet 127b stands from one end of the carrier sheet 127a in the width direction X. In the present embodiment, the second upright sheet 127c stands from the other end of the carrier sheet 127a in the width direction X. The carrier sheet 127a, the first upright sheet 127b, and the second upright sheet 127c extend along the conveying direction Y. Such a guide portion 127 can stably guide the sheet-like chafer 112N onto the sheet-like inner liner 111N without causing the sheet-like chafer 112N to fall off from the carrier sheet 127a. In the present embodiment, the first raised pieces 127 b are arranged on the inner side in the width direction X of the sheet-like liner 111N, and in the present embodiment, the second raised pieces 127 c are arranged on the outer side in the width direction X of the sheet-like liner 111N.

[0098] In the present embodiment, the guide portion 127 is provided with a guide piece 127d which extends obliquely upward from the first rising piece 127b side of the carrier piece 127a toward the second rising piece 127c side. The sheet-like chafer 112N on the carrier piece 127a is conveyed by being supported by the guide piece 127d through the upper side of the guide piece 127d. Therefore, one end of the sheet-like chafer 112N in the width direction is positioned along one end of the carrier piece 127a on the first rising piece 127b side. Thus, the position of the sheet-like chafer 112N in the width direction X can be determined with high accuracy.

[0099] The guide piece 127d has a length greater than the width of the sheet-like chafer 112N, for example. In the present embodiment, the guide piece 127d is formed of a rod-shaped member.

[0100] like Figure 7 As shown, in the present embodiment, the moving tool 128 is formed by a cylinder mechanism 129 of a known structure having a rod portion 129a that can be extended and retracted in the width direction X. A guide portion 127 is fixed to the rod portion 129a of the present embodiment. The position of the guide portion 127 in the width direction X is determined by the extension and retraction of the rod portion 129a. The extension and retraction amount of the rod portion 129a is determined based on the electrical signal from the imaging unit 123 input to the control unit 124. As a result, the sheet-like chafer 112N guided by the guide portion 127 moves to a predetermined position in the width direction X. Therefore, in the manufacturing method of the present embodiment, the composite lining 113 can be manufactured with high precision. In addition, the moving tool 128 is not limited to such a cylinder mechanism, and may also have a ball screw mechanism or a pinion rack mechanism, for example.

[0101] The pressing roller 126 is used, for example, to press and attach the sheet-like chafer 112N guided by the guide portion 127 to the sheet-like inner liner 111N. The pressing roller 126 of this embodiment adopts a known structure including a support shaft 126a extending in the width direction X and a roller portion 126b rotatably held on the support shaft 126a. In this embodiment, the support shaft 126a is held by a moving unit 130 of a known structure fixed to the guide portion 127 so as to be movable in three axial directions. By using such a detection device 121 and a pasting device 122, a pair of sheet-like chafers 112N are pasted at predetermined positions on both sides of the sheet-like inner liner 111N with high precision, thereby forming a composite lining 113. The composite lining 113 is formed, for example, by butting the sheet-like chafer 112N against the two ends 114e, 114e of the first rubber sheet 114.

[0102] In addition, for example, the composite lining 113 formed by the overlap position of the sheet-like chafer 112N and the sheet-like inner liner 111N deviates significantly from the predetermined specified position, which reduces the uniformity and other qualities of the tire 101. Therefore, such a composite lining 113 needs to be re-pasted in step s3. In addition, the tire 101 manufactured using the composite lining 113, for example, has residual air in the tire 101 in addition to the deterioration of uniformity, so it has to be discarded. In this way, the composite lining 113 whose overlap position deviates significantly from the specified position will cause a large manufacturing loss. In the manufacturing method of the pneumatic tire of the present embodiment, since the overlap position can be pasted at the specified position, it is possible to suppress the rework of the pasting step s3 or the discarding of the tire 101, thereby suppressing the occurrence of manufacturing losses.

[0103] In this manufacturing method, after the composite lining forming step S1, a composite lining winding step S2, a carcass ply winding step S3, a bead core mounting step S4, and a molding step S5 are performed.

[0104] like Fig. 9 As shown in (a), in the composite lining winding step S2, for example, the composite lining 113 is wound on the outer peripheral surface of a forming drum 132 of a known structure. Fig. 9 As shown in (b), in the carcass ply winding step S3, for example, a sheet-shaped carcass ply 106N is wound on the outside of the composite lining 113 to form a cylindrical carcass laminate M. In the bead core installation step S4, for example, a pair of bead core assemblies K consisting of a bead core 105 and a bead apex 108 are provided on both end sides of the outer peripheral surface of the carcass laminate M. Fig. 9As shown in (c), in the forming step S5, for example, while the bead core assemblies K and K are brought close to each other, the carcass laminate is formed into a ring shape between the bead core assemblies K and K. As a result, the expanded portion of the carcass laminate M is joined to the tread ring P that forms the tread rubber 102G and the tread reinforcing layer 107 that are previously waiting outside the tire radial direction, and an unvulcanized green tire 101a is formed. The composite lining winding step S2, the carcass ply winding step S3, the bead core installation step S4, and the forming step S5 adopt various conventional methods.

[0105] Fig.10 express Figure 7 A modified example of the manufacturing device 133 shown in FIG. In the manufacturing device 201, Figure 1 The edge detection device 22 shown is used as the detection device 222. In the manufacturing method using the manufacturing device 201, the two ends 114e of the first rubber sheet 114 are detected by using the detection device 222 in the detection step s2.

[0106] In the description of this manufacturing method, the first rubber sheet 114 corresponds to the first sheet 28. The end 114e of the first rubber sheet 114 corresponds to the edge 32 of the first sheet 28. The second rubber sheet 115 corresponds to the second sheet 30.

[0107] In the manufacturing device 201, in addition to the detection device 222, there are Figure 7 The structure of the manufacturing device 133 shown in the figure is the same. Except for the detection device 222, the same reference numerals are given and the description thereof is omitted.

[0108] The detection device 222 includes a line camera 238, a pair of lighting units 240, and a control unit 242. The line camera 238 corresponds to Figure 7 The shooting unit 123 of the detection device 121 shown. The control unit 242 corresponds to Figure 7 The control unit 124 of the detection device 121 is shown.

[0109] In the detection device, the line camera 238 captures an image of the entire width direction of the liner 111N corresponding to the composite sheet 24. The field of view of the line camera 238 includes both ends 114e of the first rubber sheet 114 located on the second rubber sheet 115.

[0110] In the detection device 222, the illuminating units 240 located on both sides of the line camera 238 irradiate the liner 111N with light. The portion irradiated with light from the first illuminating unit 244 is irradiated with light from the second illuminating unit 246. The line camera 238 captures images of the portion irradiated with light from the two illuminating units 240.

[0111] In the detection device 222, an image reflecting the surface state of the inner liner 111N, in particular, an image reflecting the contrast difference of the boundary position of the first rubber sheet 114 and the second rubber sheet 115 is captured. Therefore, although the first rubber sheet 114 and the second rubber sheet 115 are the same color and appear black, in the image, both ends 114e of the first rubber sheet 114 located on the second rubber sheet 115 are clearly displayed. Based on the image, the positions of the both ends 114e of the first rubber sheet 114 are detected.

[0112] In the attaching device 122, the sheet-like chafer 112N on the mounting sheet 127a is conveyed by being supported by the guide sheet 127d through the upper side of the guide sheet 127d. Therefore, one end of the sheet-like chafer 112N in the width direction is positioned along one end of the mounting sheet 127a on the first rising piece 127b side. Thus, the position of the sheet-like chafer 112N in the width direction X can be determined with high accuracy.

[0113] The position of the guide portion 127 in the width direction X is determined by the extension and contraction of the rod portion 129a. The extension and contraction amount of the rod portion 129a is determined based on the electrical signal from the line camera 238 input to the control unit 242. As a result, the sheet-like chafer 112N guided by the guide portion 127 moves to a predetermined position in the width direction X. Therefore, the manufacturing method of this embodiment can manufacture the composite lining 113 with high accuracy.

[0114] In this manufacturing method, a pair of sheet-like chafers 112N are accurately attached to the sheet-like inner liner 111N at predetermined positions using the detection device 222 and the attachment device 122 to form a composite lining 113. The composite lining 113 is formed by, for example, butting the sheet-like chafer 112N against both ends 114e, 114e of the first rubber sheet 114.

[0115] In this manufacturing method, the sheet-like chafer 112N is correctly pasted at the correct position by reflecting the detected position data of the two ends 114e, 114e of the first rubber sheet 114 in the action program for forming the composite lining 113. Based on the detected position data of the two ends 114e, 114e, the width of the first rubber sheet 114 stacked on the second rubber sheet 115 can also be confirmed. In this manufacturing method, a high-quality tire 2 is manufactured. Moreover, in this manufacturing method, since the overlapping position can be pasted at a specified position, rework of the pasting step s3 or discarding of the tire 101 can be suppressed. This manufacturing method can suppress the occurrence of manufacturing losses. This manufacturing method can stably manufacture high-quality tires 101.

[0116] In this manufacturing method, as long as the correct position data of the two ends 114e, 114e of the first rubber sheet 114 can be obtained, the position for capturing the image for detecting the two ends 114e, 114e of the first rubber sheet 114 can be set to the upstream side or the downstream side of the position where the sheet-like chafer 112N is attached. Based on the understanding of the positions of the two ends 114e, 114e of the first rubber sheet 114, from the viewpoint of attaching the sheet-like chafer 112N, it is preferred that the position for capturing the image for detecting the two ends 114e, 114e of the first rubber sheet 114 be set to the upstream side of the position where the sheet-like chafer 112N is attached.

[0117] As mentioned above, although the particularly preferred embodiments of the present invention have been described in detail, the present invention is not limited to these embodiments, and can be implemented in various modified forms.

[0118] [Example]

[0119] The present invention will be described in further detail below with reference to Examples and the like, but the present invention is not limited only to the following Examples.

[0120] In order to confirm the effect of the present invention, Figure 7 The detection device and the pasting device shown are manufactured Figure 5 The composite lining shown is used to measure the difference δ between the actual pasting position of the sheet-like chafer and the predetermined specified position. 5,000 sheets of the composite lining are manufactured in both the embodiment and the comparative example. In addition, a pneumatic tire containing the composite lining is manufactured through the composite lining winding step S2, the carcass cord layer winding step S3, the bead core installation step S4 and the molding step S5 of the existing method, and the known vulcanization step. In addition, the composite lining of the comparative example is formed by overlapping the sheet-like inner liner and the sheet-like chafer by manual operation of the operator. The general specifications of the composite lining are as follows.

[0121] First sheet rubber: 110000mm×500mm×1.0mm (length×width×thickness)

[0122] Second sheet rubber: 110000mm×570mm×1.0mm (length×width×thickness)

[0123] Chafer rubber: 110000mm×45mm×0.8mm (length×width×thickness)

[0124] <Process capability index Cpk>

[0125] The deviation range (tolerance) of the difference δ is set to ±5.0 mm, and the process capability index Cpk value is calculated. The Cpk value is calculated by the following formula (1).

[0126] Cpk value = (1-K) × Cp (1)

[0127] Cp=(UL) / (6×σ)

[0128] K=|(U+L) / 2-μ| / (UL) / 2: Skewness

[0129] U: Upper limit standard (tolerance upper limit value)

[0130] L: Lower limit standard (lower limit of tolerance)

[0131] σ: standard deviation of the deviation

[0132] μ: average value of deviation

[0133] As a result, the larger the Cpk value, the better. In addition, a graph showing the ratio of the difference δ using the measurement results is shown as follows: Fig.11 shown. Fig.11 (a) is the ratio of the difference δ in the manufacturing method of this embodiment. Fig.11 (b) is the ratio of the difference δ of the manufacturing method of the comparative example.

[0134] <Material return rate and tire scrap rate>

[0135] Based on the difference δ measured when calculating the process capability index, the ratio of the composite lining returned to the composite lining forming step and the ratio of the pneumatic tires that failed the uniformity inspection are calculated through inspection after the composite lining winding step S2. The result is expressed as a ratio, and the smaller the value, the better.

[0136] Table 1 shows the test results.

[0137]

Table 1

[0138] Example Comparative Example Process Capability Index (Cpk) 1.195 0.948 Material return rate [%] 0 2.0 Tire scrap rate [%] 0 0.12

[0139] As a result of the test, it was confirmed that the manufacturing method of the embodiment can manufacture the composite lining with high precision compared with the manufacturing method of the comparative example. Fig.11 As shown in (a), the total number of differences δ is within the range of -2.0 mm to 3.0 mm. Furthermore, more than about 85% of the total number is controlled within the range of -2.0 mm to 2.0 mm. In addition, in the manufacturing method of the comparative example, Fig.11 As shown in (b), the total number of differences δ is within the range of -4.0 mm to 5.0 mm, which is wider than that of the embodiment. In addition, about 75% of the total number is within the range of -2.0 mm to 2.0 mm, which is smaller than that of the embodiment. In addition, the "-" of the difference δ indicates that the attachment position of the sheet-like chafer is closer to the center side of the width direction of the sheet-like inner liner than the predetermined specified position.

[0140] Industrial Applicability

[0141] The above-described technique for detecting the edge position of a sheet in a composite sheet can also be applied to detecting the edge position of other tire materials.

Claims

1. An edge detection device for detecting an edge of a sheet located on another sheet in a composite sheet material formed by laminating at least two sheets containing rubber, wherein the edge positions of the at least two sheets are offset in the width direction, the edge detection device being an edge detection device for tire materials, wherein: The edge detection device comprises: A line camera that captures an image of the composite sheet in the width direction; a pair of lighting units that irradiate light toward the composite sheet; as well as a control unit for analyzing the image data captured by the line camera, In the length direction of the composite sheet, the pair of lighting units are arranged across the line camera. The portion illuminated by the light of one lighting unit is illuminated by the light of another lighting unit. The pair of illumination units illuminates a range including two edges on both sides of the width direction of another sheet on one sheet, and the field of view of the line camera includes two edges on both sides of the width direction of another sheet on one sheet, thereby enabling the width of the other sheet stacked on the one sheet to be measured based on image data including the two edges captured by the line camera. The control unit detects, based on the image data, a position of an edge of another sheet located on one sheet and extending in a length direction of the composite sheet.

2. The edge detection device according to claim 1, wherein: The line camera captures an image in the width direction of the composite sheet located directly below it.

3. The edge detection device according to claim 1 or 2, wherein: An angle formed by a direction of light from the one illumination unit with respect to an optical axis of the line camera is the same as an angle formed by a direction of light from the other illumination unit with respect to the optical axis of the line camera.

4. The edge detection device according to claim 1 or 2, wherein: The edge detection device includes a conveying unit that conveys the composite sheet in the longitudinal direction of the composite sheet.

5. A method for manufacturing a pneumatic tire, the pneumatic tire comprising an inner liner and a pair of chafers disposed at both ends of the inner liner in the tire axial direction, wherein: The pneumatic tire manufacturing method includes a composite lining forming step of forming a composite lining, wherein the composite lining is formed by compounding an unvulcanized sheet-like inner liner and a pair of unvulcanized sheet-like chafers. The composite lining forming process comprises: a lining forming step of overlapping a first rubber sheet with a second rubber sheet having a width wider than the first rubber sheet to form the sheet-like lining; a detection step of capturing an image of the entire width direction of the sheet-like liner by a line camera, and simultaneously detecting both ends in the width direction of the first rubber sheet which overlaps the second rubber sheet and is narrower than the second rubber sheet based on the image, thereby being able to confirm the width of the first rubber sheet which overlaps the second rubber sheet based on the positions of the both ends; and a pasting step of pasting the sheet-like inner liner and each of the sheet-like chafers based on the detected positions of both ends of the first rubber sheet, The attaching step includes a positioning step of positioning each of the sheet-like chafers along one end in the width direction of a placing piece of a guide portion for guiding the sheet-like chafer to the sheet-like inner liner.

6. The method for manufacturing a pneumatic tire according to claim 5, wherein: In the detecting step, an imaging unit for imaging both ends of the first rubber sheet is used.

7. The method for manufacturing a pneumatic tire according to claim 5 or 6, wherein: The second rubber sheet of the sheet-like inner liner extends to the outside of both ends of the first rubber sheet.

8. The method for manufacturing a pneumatic tire according to claim 7, wherein: In the attaching step, the second rubber sheet and each of the sheet-like chafers are overlapped at positions outside both ends of the first rubber sheet.

9. The method for manufacturing a pneumatic tire according to claim 5 or 6, wherein: In the positioning step, each of the sheet-like chafers passes on an upper side of a guide piece of the guide portion that is inclined upward from the one end side toward the other end side of the mounting piece.

Images