Belt manufacturing apparatus, retrieval roller, and belt manufacturing method

Abstract

Provided are a belt manufacturing apparatus, a turn-back roller, and a belt manufacturing method that prevent deterioration of reliability or durability of a tire even when the thickness of a member used in a belt layer of the tire is reduced. A belt manufacturing apparatus (200) according to the present disclosure is characterized by comprising: a transport unit (main belt transport unit (50)) for a main belt material (10); and a rubber sheet folding-back unit (30) that includes a folding-back roller (31) that folds back a region of the rubber sheet (20) that protrudes outward from both ends of the main belt material (10) in the width direction from one side of the main belt material (10) to the other side of the main belt material (10). The belt manufacturing equipment (200) is further characterized in that in the return roller (31), the roller surface in contact with the rubber sheet (20) is formed by an elastic member (31c), and the elastic member (31c) can elastically deform towards the radial inner side of the return roller (31).

Description

[0001] Cross-reference to related applications

[0002] This application claims priority based on JP2022-198096A filed in Japan on December 12, 2022, the entire specification of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to a belt manufacturing apparatus, a return roller, and a belt manufacturing method. Background art

[0004] In recent years, in order to improve the fuel efficiency of automobiles, the demand for reducing the rolling resistance of tires has been increasing. One means of reducing the rolling resistance of tires is to reduce the weight of tire components, particularly the belt layer. For example, in the method of manufacturing a tire reinforcing member described in Patent Document 1, an attempt is made to reduce the tire weight by making the main belt material (tire reinforcing member) and the rubber sheet covering the edge portion of the main belt material (edge belt) thinner.

[0005] Prior art documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-276215 Summary of the invention

[0008] Problems to be solved by the invention

[0009] However, when the main belt material and the rubber sheet are made thinner, wrinkles are more likely to occur when the rubber sheet is attached to the edge portion of the main belt material, and air is more likely to enter between the main belt material and the rubber sheet, leaving room for improvement in terms of the reliability and durability of the belt layer.

[0010] It would be helpful to provide a belt manufacturing apparatus, a return roller, and a belt manufacturing method that do not deteriorate the reliability and durability of a tire even when the materials used in the belt layer of the tire are made thinner.

[0011] Solutions to the problems

[0012] To solve the above technical problems, the belt manufacturing apparatus according to the present disclosure is [1]

[0014] A belt manufacturing apparatus for manufacturing a belt in which both widthwise ends of a main belt material are wrapped with rubber sheets, the belt manufacturing apparatus including:

[0015] A conveying unit for the main belt material; and

[0016] A rubber sheet folding unit, which includes folding rollers configured to fold regions of the rubber sheet protruding outward from both ends in the width direction of the main belt material from one side of the main belt material to the other side of the main belt material, wherein,

[0017] The folding rollers are arranged at both ends in the width direction of the main belt material, and the roller surfaces in contact with the rubber sheet are formed of elastic members that can elastically deform radially inward of the folding rollers.

[0018] By adopting such a configuration, the rubber sheet receives an elastic force in a direction toward the center in the width direction of the main belt material from the elastic member, so that the rubber sheet can be bent when the rubber sheet is pressed against the main belt material with a defined load. Therefore, even when the width W of the main belt material varies within the expected range, the folding rollers can continuously follow the width W of the main belt material, and the elastic member continuously provides an elastic force in a direction toward the center in the width direction to the main belt material and the rubber sheet. Therefore, the occurrence of defects can be suppressed, examples of which include air entering between the rubber sheet and the main belt material when folding the rubber sheet when the width of the main belt material is less than the standard width, or wrinkles formed on the rubber sheet when folding the rubber sheet when the width of the main belt material is greater than the standard width.

[0019] In addition, according to the belt manufacturing apparatus of the present disclosure, [2]

[0021] According to the configuration described in [1] above, preferably, it further includes a rubber sheet supply unit configured to supply the rubber sheet to both ends in the width direction of one side of the conveyed main belt material and supply the rubber sheet overlapping the main belt material in a manner protruding outward from both ends in the width direction of the conveyed main belt material.

[0022] By adopting such a configuration, the rubber sheet can be accurately positioned relative to the main belt material in the width direction of the main belt material, effectively suppressing the occurrence of defects such as wrinkles on the rubber sheet when folding the rubber sheet.

[0023] In addition, according to the belt manufacturing apparatus of the present disclosure, [3]

[0025] According to the configuration described in [1] or [2] above, preferably, the elastic member is a spring member.

[0026] By adopting such a configuration, the folding rollers can follow the width of the main belt material with a simple configuration and press the rubber sheet against the ends in the width direction of the main belt material with a defined load.

[0027] In addition, according to the belt manufacturing apparatus of the present disclosure, [4]

[0029] According to the structure described in any one of [1] to [3] above, it is preferably further configured such that the return roller is arranged on the upstream side of the position where the main belt material is brought into the rubber sheet return unit, and the belt manufacturing apparatus preferably further includes an auxiliary roller downstream of the return roller, the auxiliary roller being configured to facilitate the return of the rubber sheet to the other side.

[0030] By adopting such a structure, the rubber sheet that has been folded by the return roller to be substantially perpendicular to the main belt material can be further returned to align with the other side of the main belt material.

[0031] In addition, for the belt manufacturing apparatus according to the present disclosure, [5]

[0033] According to the structure described in [4] above, it is preferably further configured such that the auxiliary roller is inclined in a direction in which the folding angle of the rubber sheet increases as the rubber sheet comes into contact with the roller surface of the auxiliary roller relative to the return roller or another auxiliary roller adjacent to the auxiliary roller on the upstream side.

[0034] By adopting such a structure, the rubber sheet that has been folded by the return roller to be substantially perpendicular to the main belt material can be further gradually returned to align with the other side of the main belt material.

[0035] In addition, for the belt manufacturing apparatus according to the present disclosure, [6]

[0037] According to the structure described in [4] or [5] above, it is preferably further configured such that the roller surface of the auxiliary roller is provided on the outer ring of a bearing that is arranged at a plurality of positions along the axial direction and is rotatable relative to the shaft member.

[0038] By adopting such a structure, the rotation of the roller surface in the axial direction can be changed according to the contact state between the roller surface of the auxiliary roller and the rubber sheet, thereby suppressing an increase in friction between the roller surface of the auxiliary roller and the rubber sheet.

[0039] In addition, for the belt manufacturing apparatus according to the present disclosure, [7]

[0041] According to the structure described in any one of [4] to [6] above, it is preferably further configured such that the roller surface of the auxiliary roller is coated with an anti-adhesion coating by filling the concave portions of the unevenness of the roller surface with resin.

[0042] By adopting such a structure, the adhesion of the rubber sheet to the roller surface of the auxiliary roller can be effectively suppressed, and the conveying resistance can be suppressed. In addition, the rubber sheet is not subjected to unexpected tension, so that wrinkling of the rubber sheet can be suppressed.

[0043] In addition, the belt manufacturing apparatus according to the present disclosure [8]

[0045] According to the structure described in [2] above, it is preferably further configured such that the main belt material and the rubber sheet pass through a position higher than the height position of the main belt material in the upstream conveying unit and higher than the height position of the rubber sheet in the rubber sheet supply unit in the rubber sheet folding unit.

[0046] By adopting this structure, appropriate tension is applied to the main belt material and the rubber sheet in the rubber sheet folding unit, and the end portions in the width direction of the rubber sheet are slightly pulled downward in the rubber sheet folding unit and droop with respect to the main belt material. This can prevent the rubber sheet from strongly contacting the folding roller.

[0047] In addition, the folding roller according to the present invention is [9]

[0049] A folding roller used in a belt manufacturing apparatus for manufacturing a belt, the belt including a main belt material wrapped with rubber sheets at both ends in the width direction, wherein

[0050] the folding roller is configured to fold back the regions of the rubber sheets protruding outward from both ends in the width direction of the main belt material from one side of the main belt material to the other side of the main belt material, and the folding roller includes:

[0051] a shaft member; a plurality of rotating members separately arranged in the axial direction of the shaft member and capable of rotating around the shaft member; and an elastic member connecting the rotating members in the axial direction and forming a roller surface with which the rubber sheet contacts.

[0052] By adopting this structure, the rubber sheet receives an elastic force in the direction toward the center in the width direction of the main belt material from the elastic member, and thus the rubber sheet can be bent when pressing the rubber sheet against the main belt material with a defined load. Therefore, even when the width W of the main belt material varies within an expected range, the folding roller can continuously follow the width W of the main belt material, and the elastic member continuously provides an elastic force in the direction toward the center in the width direction to the main belt material and the rubber sheet. Therefore, the occurrence of defects can be suppressed, examples of which include air entering between the rubber sheet and the main belt material when folding back the rubber sheet when the width of the main belt material is smaller than the standard width, or wrinkles formed on the rubber sheet when folding back the rubber sheet when the width of the main belt material is larger than the standard width.

[0053] In addition, the belt manufacturing method according to the present invention is

[10]

[0055] A belt manufacturing method for manufacturing a belt including a main belt material wrapped with rubber sheets at both ends in the width direction, the belt manufacturing method comprising:

[0056] a step of conveying the main belt material; and

[0057] a folding step of folding, by means of folding rollers, regions of the rubber sheets protruding outward from both ends in the width direction of the main belt material from one side of the main belt material to the other side of the main belt material, wherein,

[0058] the folding rollers are arranged at both ends in the width direction of the main belt material, and the roller surfaces in contact with the rubber sheets are formed of elastic members that can elastically deform radially inward of the folding rollers.

[0059] With this configuration, the rubber sheets receive an elastic force in a direction toward the center in the width direction of the main belt material from the elastic members, and thus the rubber sheets can be bent when the rubber sheets are pressed against the main belt material with a defined load. Therefore, even when the width W of the main belt material varies within an expected range, the folding rollers can continuously follow the width W of the main belt material, and the elastic members continuously provide an elastic force in a direction toward the center in the width direction to the main belt material and the rubber sheets. Therefore, the occurrence of defects can be suppressed, examples of which include air entering between the rubber sheets and the main belt material when folding the rubber sheets when the width of the main belt material is smaller than the standard width, or wrinkles formed on the rubber sheets when folding the rubber sheets when the width of the main belt material is larger than the standard width.

[0060] Effects of the Invention

[0061] According to the present disclosure, it is possible to provide a belt manufacturing apparatus, folding rollers, and a belt manufacturing method that do not deteriorate the reliability and durability of a tire even when the material used in the belt layer of the tire is made thinner. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In the drawings:

[0063] Figure 1A is a view showing the configuration of a belt manufacturing apparatus according to an embodiment of the present disclosure;

[0064] Figure 1B is a cross-sectional view of a belt produced by a belt manufacturing apparatus according to an embodiment of the present disclosure;

[0065] Figure 2 is a perspective view showing the configuration of a rubber sheet folding unit used in a belt manufacturing apparatus according to an embodiment of the present disclosure;

[0066] Figure 3is a front view cross-sectional view of a folding roller of a rubber sheet folding unit used in a belt manufacturing apparatus according to an embodiment of the present disclosure;

[0067] Figure 4A is a view showing a main belt material having a standard width in contact with an elastic member of the folding roller shown in Figure 3 cross-sectional view;

[0068] Figure 4B is a view showing a main belt material having a width smaller than the standard width in contact with an elastic member of the folding roller shown in Figure 3 cross-sectional view;

[0069] Figure 4C is a view showing a main belt material having a width larger than the standard width in contact with an elastic member of the folding roller shown in Figure 3 cross-sectional view; and

[0070] Figure 5 is a flowchart showing a process of a belt manufacturing method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0071] A belt manufacturing apparatus 200 according to the present disclosure will be described below with reference to the drawings. Components and parts common to each drawing are denoted by the same reference numerals.

[0072] Figure 1A is a view showing a configuration of a belt manufacturing apparatus 200 according to an embodiment of the present disclosure.

[0073] As Figure 1A shown, the belt manufacturing apparatus 200 includes: a main belt conveying unit 50 that conveys a main belt material 10 that is a main component of the belt 100; a rubber sheet supply unit 40 that supplies a rubber sheet 20 to both ends in the width direction on one side ( Figure 1A the upper side in) of the conveyed main belt material 10; a rubber sheet folding unit 30 that includes a folding roller 31 that folds a region of the rubber sheet 20 protruding outward from both ends in the width direction of the main belt material 10 from one side of the main belt material 10 to the other side of the main belt material 10 ( Figure 1A the lower side in). In the plane of the main belt material 10, the width direction of the main belt material 10 is orthogonal to the longitudinal direction ( Figure 1A the left-right direction in).

[0074] As Figure 1A shown, the main belt conveying unit 50 is arranged in the direction of the arrow in the figure toward the downstream ( Figure 1AA rubber sheet folding unit 30 (on the left side in the figure) conveys the main belt material 10 cut and joined from the main belt roll material 10a in a rolled state. The main belt roll material 10a is cut at a defined interval such that the cutting width W (that is, the width W of the main belt material 10 after joining) is equal, but the cutting width W has a variation of approximately 2 mm to 3 mm (peak to peak). Therefore, the variation in the cutting width W becomes the variation in the width W of the main belt material 10 after joining.

[0075] Although Figure 1A Only a conveyor for conveying the main belt material 10 as the main belt conveying unit 50 is shown, but the main belt conveying unit 50 may include a control motor, a control device, etc. in addition to the conveyor.

[0076] According to the present embodiment, the main belt material 10 has a thickness of, for example, approximately 0.8 mm, and has a structure in which multiple cords are embedded in a coated rubber. In the main belt material 10, generally, multiple cords are stretched side by side. Such cords are usually steel cords. In addition, there is no particular limitation on the structure of such cords. However, from the viewpoint of effectively achieving both improved tire durability and low rolling resistance, the cord preferably has a 1×N structure in which N filaments are twisted together (where N is an integer selected from 2 to 6). In particular, for a tire with a tire load index less than 100, the above cord preferably has a 1×2 structure, and for a tire with a tire load index of 100 or more, the above cord preferably has a 1×5 structure. In addition, from the same viewpoint, the cord is preferably filaments that are not twisted together and are stretched side by side. In addition, in the case of the above 1×N structure, the cord may have a 1×N open structure in which the filaments are twisted together with a space between them and do not contact each other. A cord with an open structure has excellent fatigue resistance compared to a cord in which the filaments are twisted together in a state of contacting each other.

[0077] A 1×N open structure cord can be formed by placing uncured rubber between the filaments and twisting the filaments together, or by coating the surface of the filaments with uncured rubber and then twisting the filaments together.

[0078] The filaments of the cord used in the main belt material 10 are preferably classified as ST grade (super high tensile strength cord) or UT grade (ultra high tensile strength cord) as defined in ISO 17832:2018, and particularly preferably classified as UT grade. In this case, both improved tire durability and lower rolling resistance can be effectively achieved.

[0079] The main belt material 10 is not limited to the above form as long as the main belt material 10 has some strengthening structure.

[0080] The coating rubber for the main belt material 10 is not particularly limited as long as it is a typical rubber component capable of coating the cord. Examples of the rubber component are diene rubbers, and in particular, natural rubber or isoprene rubber is preferred. Additionally, fillers such as carbon black can be blended into the coating rubber to such an extent that properties such as adhesiveness and durability as the coating rubber are not affected. As the carbon black, HAF type carbon black is preferred, and the content of carbon black in the coating rubber can be 50 to 70 parts by mass per 100 parts by mass of the rubber component. Additionally, in addition to the above components, the coating rubber can appropriately contain, for example: vulcanization accelerators; crosslinking chemicals such as sulfur, zinc oxide, etc.; adhesion promoters such as cobalt compounds including cobalt salts, etc.; anti-aging agents; oils; resins, etc. As the anti-aging agent, examples include amine anti-aging agents such as 6PPD, bisphenol anti-aging agents such as o-MBp14, etc., and one or more of such anti-aging agents can be used alone or in combination.

[0081] The main belt roll material 10a that has been cut and joined is conveyed downstream (to the Figure 1A left side in Figure 1A ), and the rubber sheet 20 from the rubber sheet supply unit 40 is supplied to both ends in the width direction on one side (the Figure 1B upper side in Figure 1A and Figure 1B ) of the main belt material 10. The rubber sheet supply unit 40 supplies the rubber sheet 20 that overlaps on one side (the upper side) of the main belt material 10 in a manner that protrudes outward from both ends in the width direction of the conveyed main belt material 10. According to the present embodiment, the rubber sheet 20 is arranged such that the region of the rubber sheet 20 that protrudes outward from the main belt material 10 in the width direction is wider than the width of the region of the rubber sheet 20 that overlaps the top surface of the main belt material 10. As Figure 1A and Figure 1B shown, the belt 100 produced by the belt manufacturing apparatus 200 according to the present embodiment has a configuration in which the width of the rubber sheet 20 that overlaps the other side (the Figure 1A and Figure 1BThe belt plies are stacked in such a way that the lower sides (in the lower side in the figure) are in close contact with each other to suppress the formation of gaps between the belt plies 100. However, there is no limitation in this configuration, and the width of the rubber sheet 20 overlapping one side of the main belt ply material 10 can be configured to be equal to the width of the rubber sheet 20 overlapping the other side of the main belt ply material 10. Additionally, the width of the rubber sheet 20 overlapping the other side of the main belt ply material 10 can be configured to be smaller than the width of the rubber sheet 20 overlapping one side of the main belt ply material 10.

[0082] Although Figure 1A only the conveyor for conveying the rubber sheet 20 as the rubber sheet supply unit 40 is shown, the rubber sheet supply unit 40 may further include a control motor, a control device, etc. in addition to the conveyor.

[0083] According to the present embodiment, the thickness of the rubber sheet 20 may be, for example, about 0.4 mm to 0.5 mm. The material of the rubber sheet 20 is not particularly limited. For example, the same rubber component as the coating rubber of the main belt ply material 10 can be used.

[0084] Downstream of the rubber sheet supply unit 40 ( Figure 1A on the left side in the figure) is the rubber sheet folding unit 30. The rubber sheet folding unit 30 includes a folding roller 31 that folds back the regions of the rubber sheet 20 protruding outward from both ends in the width direction of the main belt ply material 10 to the other side of the main belt ply material 10. As Figure 1A shown, the rubber sheet folding unit 30 is arranged such that the main belt ply material 10 passes through a position higher than the height at the upstream main belt ply conveying unit 50. As Figure 1A shown, the rubber sheet folding unit 30 is provided on both sides in the width direction of the main belt ply material 10, where the rubber sheet 20 overlaps both sides in the width direction.

[0085] Figure 2 One side of the rubber sheet folding unit 30 provided on both sides in the width direction of the main belt ply material 10 is shown. As Figure 2 shown, the rubber sheet folding unit 30 includes a folding roller 31 that folds back the regions of the rubber sheet 20 protruding outward from both ends in the width direction of the main belt ply material 10 to the other side of the main belt ply material 10. Figure 2 The left side in the figure is the upstream side, and the main belt ply material 10 and the rubber sheet 20 are brought into the rubber sheet folding unit 30 from the left side in the direction of the arrow. Figure 2 from the left side of

[0086] The main belt material 10 that is brought into the rubber sheet folding unit 30 together with the rubber sheet 20 is supported from below by the main belt material support roller 37. Further, the rubber sheet holding roller 34 is disposed above the brought-in main belt material 10 at the left end of the rubber sheet folding unit 30. The front end of the rubber sheet holding roller 34 is disposed to be inclined in a direction in which the upward interval from the main belt material 10 increases, from the end in the width direction of the main belt material 10 toward the center in the width direction of the main belt material 10. For example, when the width W of the main belt material 10 is greater than the standard width, the rubber sheet holding roller 34 prevents the main belt material 10 and the rubber sheet 20 from strongly impacting the elastic member 31c (spring member) included in the folding roller 31 described below and damaging the elastic member 31c. In other words, the rubber sheet holding roller 34 presses down the end regions in the width direction of the main belt material 10 and the rubber sheet 20 to soften the contact with the folding roller 31.

[0087] Further, according to the present embodiment, as Figure 1A shown, the main belt material 10 and the rubber sheet 20 pass through a position in the rubber sheet folding unit 30 that is higher than the height position of the main belt material 10 in the upstream main belt conveying unit 50 and higher than the height position of the rubber sheet 20 in the rubber sheet supply unit 40. According to this configuration, appropriate tension is applied to the main belt material 10 and the rubber sheet 20 in the rubber sheet folding unit 30, and the end regions in the width direction of the rubber sheet 20 are slightly pulled downward in the rubber sheet folding unit 30 and sag with respect to the main belt material 10. This can also prevent the rubber sheet 20 from strongly contacting the folding roller 31.

[0088] The main belt material 10 and the rubber sheet 20 that have passed through the rubber sheet holding roller 34 pass through the folding roller 31 that is oriented in a vertical direction substantially perpendicular to the main belt material 10. As Figure 3 shown, the folding roller 31 includes: a shaft member 31a; a plurality of rotating members 31b that are separately arranged in the axial direction of the shaft member 31a and are capable of rotating around the shaft member 31a; and an elastic member 31c that connects the rotating members 31b in the axial direction and forms the roller surface that the rubber sheet 20 contacts.

[0089] According to the present embodiment, the elastic member 31c is configured as a tension spring and is fixed to the rotating member 31b by fitting the outer surface of the reduced-diameter portion of each rotating member 31b that is disposed near the axial end of the shaft member 31a but separated from the axial end of the shaft member 31a to the inner surface of the tension spring. The elastic member 31c fixed to the rotating member 31a can rotate around the axis together with the rotating member 31b with respect to the shaft member 31a.

[0090] Figure 4AShows the main belt material 10 with a standard width W in contact with the elastic member 31c of the return roller 31 and the rubber sheet 20 fixed to the main belt material 10. The elastic member 31c of the return roller 31 is arranged in the width direction such that when in contact with the rubber sheet 20 and the main belt material 10 with the standard width, the elastic member 31c elastically deforms radially inward in a manner approaching the shaft member 31a. With this configuration, the main belt material 10 and the rubber sheet 20 receive an elastic force in the direction toward the center in the width direction from the elastic member 31c, so that the rubber sheet 20 can be bent while pressing the rubber sheet 20 against the main belt material 10 with a defined load. The radial direction is along a straight line perpendicular to the central axis (a line passing through the center in the left - right direction in Figure 3 from top to bottom) passing through the return roller 31. In addition, the radially inner side means the direction along the straight line approaching the central axis.

[0091] Figure 4B Shows the rubber sheet 20 in contact with the elastic member 31c of the return roller 31 when the main belt material 10 has a width W smaller than the standard width. According to this embodiment, when the main belt material 10 with the lower limit width W is brought in, the elastic member 31c is arranged in the width direction such that the elastic member 31c elastically deforms slightly radially inward by contacting the rubber sheet 20. With this configuration, the main belt material 10 and the rubber sheet 20 receive an elastic force in the direction toward the center in the width direction from the elastic member 31c, so that the rubber sheet 20 can be bent while pressing the rubber sheet 20 against the main belt material 10 with an appropriate load.

[0092] Figure 4B Shows the rubber sheet 20 in contact with the elastic member 31c of the return roller 31 when the main belt material 10 has a width W larger than the standard width. According to this embodiment, when the main belt material 10 with the upper limit width W is brought in, as Figure 4C shown, the elastic member 31c is arranged in the width direction such that the elastic member 31c elastically deforms significantly radially inward by contacting the rubber sheet 20 to an extent close to but not contacting the shaft member 31a. With this configuration, the main belt material 10 and the rubber sheet 20 receive an elastic force in the direction toward the center in the width direction from the elastic member 31c, so that the rubber sheet 20 can be bent while pressing the rubber sheet 20 against the main belt material 10 with an appropriate load.

[0093] As described above, according to the present embodiment, even when the width W of the main belt material 10 varies within an expected range, this configuration enables the main belt material 10 and the rubber sheet 20 to always receive an elastic force in the direction toward the center in the width direction from the elastic member 31c. This configuration allows the return roller 31 to follow the width W of the main belt material 10 and allows the return roller 31 to press the rubber sheet 20 against the width-direction ends of the main belt material 10 with a defined load. Therefore, the occurrence of defects can be suppressed, examples of which include air entering between the rubber sheet 20 and the main belt material 10 when folding back the rubber sheet 20 when the width W of the main belt material 10 is less than the standard width, or wrinkles formed on the rubber sheet 20 when folding back the rubber sheet 20 when the width W of the main belt material 10 is greater than the standard width.

[0094] According to the present embodiment, it is assumed that the variation in the width W of the main belt material 10 is approximately 2 mm to 3 mm, and it is assumed that Figures 4A to 4C the position variation of the ends of the main belt material 10 in

[0095] The rubber sheet 20 that has been folded back by approximately 90 degrees to the other side (lower side) of the main belt material 10 by the return roller 31 is gradually folded back by five auxiliary rollers from the first auxiliary roller 33a to the fifth auxiliary roller 33e that are arranged adjacent to the downstream of the return roller 31 in Figure 2 in order to align with the other side ( Figure 1A the lower side in

[0096] As Figure 2 shown, the first auxiliary roller 33a is relative to the upstream side ( Figure 2The return roller 31 (on the left side in ) is arranged such that the lower end of the first auxiliary roller 33a is inclined upward by 15 degrees with respect to the upper end toward the center in the width direction of the main belt material 10. Further, the second auxiliary roller 33b is arranged with respect to the first auxiliary roller 33a adjacent on the upstream side such that the lower end of the second auxiliary roller 33b is inclined upward by an additional 15 degrees with respect to the upper end toward the center in the width direction of the main belt material 10. Thus, the five auxiliary rollers from the first auxiliary roller 33a to the fifth auxiliary roller 33e are arranged with respect to the auxiliary roller adjacent on the upstream side such that the lower end of the downstream adjacent auxiliary roller is inclined upward by an additional 15 degrees with respect to the upper end toward the center in the width direction of the main belt material 10. Thus, the fifth auxiliary roller 33e is arranged at an angle of approximately 75 degrees with respect to the return roller 31 on the upstream side. With this configuration, each time the rubber sheet 20 passing through the return roller 31 on the upstream side contacts the roller surfaces of the five auxiliary rollers from the first auxiliary roller 33a to the fifth auxiliary roller 33e, it is bent in the direction in which the return angle increases by 15 degrees. Thus, the rubber sheet 20 can be gradually and smoothly returned from a state substantially perpendicular to the main belt material 10 to a state attached to the other (lower) side of the main belt material 10.

[0097] According to the present embodiment, the roller surfaces of the first auxiliary roller 33a to the fifth auxiliary roller 33e are provided on the outer rings of ball bearings arranged at multiple positions along the axial direction and capable of rotating relative to the shaft member.

[0098] The roller surfaces of the first auxiliary roller 33a to the fifth auxiliary roller 33e may be coated with an anti-adhesion coating to prevent adhesion to the rubber sheet 20. The anti-adhesion coating is formed by filling the recesses in the unevenness of the roller surface with resin. Examples of the anti-adhesion coating include the (Tosical is a registered trademark in Japan and other countries) S coating (sequence name: TS-1080), etc. The anti-adhesion coating may be applied to the outer ring of the above-mentioned ball bearing, or to the roller surface other than the ball bearing.

[0099] When the width W of the main belt material 10 is greater than the standard width, the end portions in the width direction of the main belt material 10 may be bent upward such that the main belt material 10 can be supported by the upper portions of the auxiliary rollers. When the width W of the main belt material 10 is less than the standard width, the end portions in the width direction of the main belt material 10 may droop such that the main belt material 10 can be supported by the lower portions of the auxiliary rollers. That is, even when the width W of the main belt material 10 is greater than or less than the standard width, the first auxiliary roller 33a to the fifth auxiliary roller 33e can always contact the rubber sheet 20 and return the rubber sheet 20 toward the lower side of the main belt material 10.

[0100] The main belt material 10 and the rubber sheet 20 that have passed through the fifth auxiliary roller 33e are at a height position between the main belt material holding roller 35 and the main belt material supporting rollers 36a and 36b that are adjacent to the fifth auxiliary roller 33e and are arranged above and below it.

[0101] Finally, the main belt material 10 contacts the turning-back roller 31 on the downstream side ( Figure 2 the right side). The main belt material 10 is pressed by the turning-back roller 31 on the downstream side in the central direction in the width direction to ensure the turning-back of the rubber sheet 20 and stabilize the conveyance of the main belt material 10. The above processing completes the attachment of the rubber sheet 20 to the upper surface and the lower surface of the main belt material 10 to form the belt 100.

[0102] According to the present embodiment, the turning-back roller 31 including the elastic member 31c is arranged at the upstream and downstream ends of the rubber sheet turning-back unit 30, but this is not restrictive. The turning-back roller 31 including the elastic member 31c may be provided only on the upstream side of the rubber sheet turning-back unit 30, and may be provided at three or more positions. The turning-back roller 31 including the elastic member 31c is preferably provided upstream of the auxiliary roller.

[0103] In addition, according to the present embodiment, the roller surfaces of the first auxiliary roller 33a to the fifth auxiliary roller 33e are configured to be made of stainless steel bearings, but this is not restrictive, and at least one of the first auxiliary roller 33a to the fifth auxiliary roller 33e may be provided with a roller surface configured as an elastic member.

[0104] The following refers to Figure 5 the process of the belt manufacturing method according to the present embodiment. When manufacturing the belt 100 according to the present embodiment, first, the main belt material 10 cut and joined from the main belt coil material 10a is conveyed downstream through the main belt conveying unit 50 including a conveyor ( Figure 5 step S101 in it). The main belt conveying unit 50 may be configured to convey the main belt material 10 downstream by means other than a conveyor.

[0105] Next, the rubber sheet 20 is supplied to both ends in the width direction on one side ( Figure 1A the upper side in it) of the conveyed main belt material 10 ( Figure 5 step S102 in it). The rubber sheet supply unit 40 supplies the rubber sheet 20 overlapping on the upper surface of the main belt material 10 in a manner that protrudes outward from both ends in the width direction of the conveyed main belt material 10.

[0106] Next, the regions of the rubber sheet 20 that protrude outward from both ends in the width direction of the main belt material 10 are turned back to the other side ( Figure 1A the lower side in it) of the main belt material 10 ( Figure 5in step S103). According to the present embodiment, it includes Figure 2 The rubber sheet folding unit 30 of the folding roller 31 shown in Figure 2 is provided at each end in the width direction, and each rubber sheet folding unit 30 folds the region of the rubber sheet 20 protruding outward in the width direction to the other side. According to the present embodiment, as described above, the region of the rubber sheet 20 protruding outward in the width direction is folded by the upstream folding roller 31 in a direction perpendicular to the main belt material 10, and then further gradually folded by five auxiliary rollers arranged downstream of the folding roller 31 to align with the other side.

[0107] As described above, the present embodiment is a belt manufacturing apparatus 200 for manufacturing a belt 100 in which rubber sheets 20 are wrapped around both ends in the width direction of the main belt material 10. The belt manufacturing apparatus 200 includes: a conveying unit for the main belt material 10 (main belt conveying unit 50); a rubber sheet folding unit 30 including a folding roller 31 configured to fold the regions of the rubber sheet 20 protruding outward from both ends in the width direction of the main belt material 10 from one side of the main belt material 10 to the other side. The folding rollers 31 are arranged at both ends in the width direction of the main belt material 10, and the roller surface in contact with the rubber sheet 20 is formed by an elastic member 31c that can elastically deform radially inward of the folding roller 31. By adopting such a configuration, the rubber sheet 20 receives an elastic force in the direction toward the center in the width direction of the main belt material 10 from the elastic member 31c, so that the rubber sheet 20 can be bent when the rubber sheet 20 is pressed against the main belt material 10 with a defined load. Therefore, even when the width W of the main belt material 10 varies within the expected range, the folding roller 31 can continuously follow the width W of the main belt material 10, and the elastic member 31c continuously provides an elastic force in the direction toward the center in the width direction to the main belt material 10 and the rubber sheet 20. Therefore, the occurrence of defects can be suppressed. Examples of the defects include air entering between the rubber sheet 20 and the main belt material 10 when folding the rubber sheet 20 when the width of the main belt material 10 is smaller than the standard width, or wrinkles formed on the rubber sheet 20 when folding the rubber sheet 20 when the width of the main belt material 10 is larger than the standard width.

[0108] In addition, according to the present embodiment, it further includes a rubber sheet supply unit 40 that supplies the rubber sheet 20 to both ends in the width direction on one side of the conveyed main belt material 10 and supplies the rubber sheet 20 overlapping the main belt material 10 in a manner protruding outward from both ends in the width direction of the conveyed main belt material 10. By adopting such a configuration, the rubber sheet 20 can be accurately positioned relative to the main belt material 10 in the width direction of the main belt material 10, effectively suppressing defects such as wrinkles generated on the rubber sheet 20 when the rubber sheet 20 is folded.

[0109] In addition, according to the present embodiment, the elastic member 31c is configured as a spring member. By adopting such a configuration, the return roller 31 can follow the width W of the main belt material 10 with a simple structure and press the rubber sheet 20 against the end portions in the width direction of the main belt material 10 with a defined load.

[0110] In addition, according to the present embodiment, the return roller 31 is arranged on the upstream side where the main belt material 10 is brought into the rubber sheet return unit 30, and further includes an auxiliary roller, which is downstream of the return roller 31 and is configured to facilitate the return of the rubber sheet 20 to the other side. By adopting such a configuration, the rubber sheet 20 that has been folded at a right angle with respect to the main belt material 10 by the return roller 31 can be further returned to align with the other side of the main belt material 10.

[0111] In addition, according to the present embodiment, each auxiliary roller is configured to be inclined in a direction of increasing the folding angle of the rubber sheet 20 as the rubber sheet 20 comes into contact with the roller surface of the auxiliary roller with respect to the adjacent return roller 31 or another auxiliary roller on the upstream side. By adopting such a configuration, the rubber sheet 20 that has been folded at a right angle with respect to the main belt material 10 by the return roller 31 can be gradually returned further to align with the other side of the main belt material 10.

[0112] In addition, according to the present embodiment, the roller surface of the auxiliary roller is provided on the outer ring of a bearing that is arranged at a plurality of positions along the axial direction and is rotatable relative to the shaft member 31a. By adopting such a configuration, according to the contact state between the roller surface of the auxiliary roller and the rubber sheet 20, the rotation of the roller surface in the axial direction can be changed, thereby suppressing an increase in the friction between the roller surface of the auxiliary roller and the rubber sheet 20.

[0113] In addition, according to the present embodiment, the roller surface of the auxiliary roller is coated with an anti-adhesion coating by filling the concave portions of the unevenness of the roller surface with resin. By adopting such a configuration, the adhesion of the rubber sheet 20 to the roller surface of the auxiliary roller can be effectively suppressed, and the conveying resistance can be suppressed. In addition, the rubber sheet 20 is not subjected to an accidental tension, so that wrinkling of the rubber sheet 20 can be suppressed.

[0114] In addition, according to the present embodiment, the main belt material 10 and the rubber sheet 20 are configured to pass through a position in the rubber sheet return unit 30 that is higher than the height position of the main belt material 10 in the upstream main belt conveying unit 50 and higher than the height position of the rubber sheet 20 in the rubber sheet supply unit 40. By adopting such a configuration, an appropriate tension is applied to the main belt material 10 and the rubber sheet 20 in the rubber sheet return unit 30, and the end portions in the width direction of the rubber sheet 20 are slightly pulled downward in the rubber sheet return unit 30 and sag with respect to the main belt material 10. This can prevent the rubber sheet 20 from coming into strong contact with the return roller 31.

[0115] Further, the present embodiment is a return roller 31 used in a belt manufacturing apparatus 200 for manufacturing a belt 100. The belt 100 includes a main belt material 10 with rubber sheets 20 wrapped around both ends in the width direction. The return roller 31 is configured to return the regions of the rubber sheets 20 that protrude outward from both ends in the width direction of the main belt material 10 from one side of the main belt material 10 to the other side. The return roller 31 includes: a shaft member 31a; a plurality of rotating members 31b that are arranged separately in the axial direction of the shaft member 31a and are rotatable around the shaft member 31a; and an elastic member 31c that connects the rotating members 31b in the axial direction and forms a roller surface that the rubber sheet 20 contacts. By adopting such a configuration, the rubber sheet 20 receives an elastic force from the elastic member 31c in the direction toward the center in the width direction of the main belt material 10, and thus the rubber sheet 20 can be bent when pressing the rubber sheet 20 against the main belt material 10 with a defined load. Therefore, even when the width W of the main belt material 10 varies within the expected range, the return roller 31 can continuously follow the width W of the main belt material 10, and the elastic member 31c continuously provides an elastic force to the main belt material 10 and the rubber sheet 20 in the direction toward the center in the width direction. Therefore, the occurrence of defects can be suppressed, examples of which include air entering between the rubber sheet 20 and the main belt material 10 when returning the rubber sheet 20 when the width of the main belt material 10 is smaller than the standard width, or wrinkles formed on the rubber sheet 20 when returning the rubber sheet 20 when the width of the main belt material 10 is larger than the standard width.

[0116] In addition, the present embodiment is a belt manufacturing method for manufacturing a belt 100 including a main belt material 10, and the main belt material 10 has both widthwise ends wrapped with rubber sheets 20. The belt manufacturing method includes: a step of conveying the main belt material 10; and a step of folding back, by means of a folding-back roller 31, regions of the rubber sheets 20 protruding outward from both widthwise ends of the main belt material 10 from one side of the main belt material 10 to the other side of the main belt material 10. The folding-back roller 31 is arranged at both widthwise ends of the main belt material 10, and the roller surface in contact with the rubber sheets 20 is formed by an elastic member 31c that can elastically deform radially inward of the folding-back roller 31. By adopting such a configuration, the rubber sheets 20 receive an elastic force in a direction toward the center in the width direction of the main belt material 10 from the elastic member 31c, and thus the rubber sheets 20 can be bent when the rubber sheets 20 are pressed against the main belt material 10 with a defined load. Therefore, even when the width W of the main belt material 10 varies within an expected range, the folding-back roller 31 can continuously follow the width W of the main belt material 10, and the elastic member 31c continuously provides an elastic force in a direction toward the center in the width direction to the main belt material 10 and the rubber sheets 20. Therefore, the occurrence of defects can be suppressed, examples of which include air entering between the rubber sheets 20 and the main belt material 10 when folding back the rubber sheets 20 when the width of the main belt material 10 is smaller than the standard width, or wrinkles formed on the rubber sheets 20 when folding back the rubber sheets 20 when the width of the main belt material 10 is larger than the standard width.

[0117] Although the present disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can make variations and modifications based on the present disclosure. Therefore, it should be noted that such variations and modifications are included within the scope of the present disclosure. For example, as long as there is no logical inconsistency, the structures, functions, etc. included in each embodiment can be reconfigured. The structures, functions, etc. included in each embodiment can be used in combination with other embodiments, and multiple structures, functions, etc. can be combined, divided, or partially omitted.

[0118] For example, according to the present embodiment, an apparatus for manufacturing a belt 100, a folding-back roller 31 used in the apparatus, and a method for manufacturing a belt 100 are described, where the belt is a tire reinforcing member, but it can also be used to manufacture a belt 100 for applications other than tire reinforcing members.

[0119] In addition, according to the present embodiment, the belt manufacturing apparatus 200 is configured to include a rubber sheet supply unit 40, but is not limited to this configuration. For example, the rubber sheets 20 previously arranged at both widthwise ends on one side of the main belt material 10 can be supplied to the rubber sheet folding-back unit 30 by the main belt conveying unit 50, and the rubber sheets 20 can be folded back.

[0120] Industrial Applicability

[0121] The present disclosure relates to a belt manufacturing apparatus 200, a folding roller 31, and a belt manufacturing method that do not deteriorate the reliability and durability of a tire even when the material used in the belt layer of the tire is made thinner.

[0122] List of Reference Numerals

[0123] 10 Main belt material

[0124] 10a Main belt roll material

[0125] 20 Rubber sheet

[0126] 30 Rubber sheet folding unit

[0127] 31 Folding roller

[0128] 31a Shaft member

[0129] 31b Rotating member

[0130] 31c Elastic member

[0131] 33a First auxiliary roller

[0132] 33b Second auxiliary roller

[0133] 33c Third auxiliary roller

[0134] 33d Fourth auxiliary roller

[0135] 33e Fifth auxiliary roller

[0136] 34 Rubber sheet holding roller

[0137] 35 Main belt material holding roller

[0138] 36a Main belt material supporting roller

[0139] 36b Main belt material supporting roller

[0140] 37 Main belt material supporting roller

[0141] 40 Rubber sheet supply unit

[0142] 50 Main belt conveying unit (conveying unit)

[0143] 100 Belt

[0144] 200 Belt manufacturing apparatus

[0145] W (cutting) width

Claims

1. A belt manufacturing apparatus for manufacturing a belt in which both widthwise ends of a main belt material are wrapped with rubber sheets, the belt manufacturing apparatus comprising: a conveying unit for the main belt material; and a rubber sheet folding unit including a folding roller configured to fold a region of the rubber sheet protruding outward from both widthwise ends of the main belt material from one side of the main belt material to the other side of the main belt material, wherein, the folding roller is disposed at both widthwise ends of the main belt material, and a roller surface in contact with the rubber sheet is formed of an elastic member that can elastically deform radially inward of the folding roller.

2. The belt manufacturing apparatus according to claim 1, further comprising a rubber sheet supply unit configured to supply the rubber sheets to both widthwise ends on one side of the conveyed main belt material and to supply the rubber sheets overlapping the main belt material so as to protrude outward from both widthwise ends of the conveyed main belt material.

3. The belt manufacturing apparatus according to claim 1 or 2, wherein, The elastic member is a spring member.

4. The belt manufacturing apparatus according to claim 1 or 2, wherein, The folding roller is disposed on the upstream side of the position where the main belt material is introduced into the rubber sheet folding unit, and the belt manufacturing apparatus further includes an auxiliary roller downstream of the folding roller, the auxiliary roller being configured to facilitate the folding of the rubber sheet to the other side.

5. The belt manufacturing apparatus according to claim 4, wherein, The auxiliary roller is inclined in a direction in which the folding angle of the rubber sheet increases as the rubber sheet comes into contact with the roller surface of the auxiliary roller relative to the folding roller adjacent to the auxiliary roller on the upstream side or another auxiliary roller.

6. The belt manufacturing apparatus according to claim 4, wherein, The roller surface of the auxiliary roller is provided on the outer ring of a bearing that is disposed at a plurality of positions along the axial direction and is rotatable relative to a shaft member.

7. The belt manufacturing apparatus according to claim 4, wherein, The roller surface of the auxiliary roller is coated with an anti-adhesion coating by filling recesses in the unevenness of the roller surface with resin.

8. The belt manufacturing apparatus according to claim 2, wherein, The main belt material and the rubber sheets pass through a position that is higher than the height position of the main belt material in the upstream conveying unit and higher than the height position of the rubber sheets in the rubber sheet supply unit in the rubber sheet folding unit.

9. A folding roller used in a belt manufacturing apparatus for manufacturing a belt including a main belt material whose both widthwise ends are wrapped with rubber sheets, wherein, the folding roller is configured to fold a region of the rubber sheet protruding outward from both widthwise ends of the main belt material from one side of the main belt material to the other side of the main belt material, and the folding roller includes: a shaft member; a plurality of rotating members that are separately arranged in the axial direction of the shaft member and are rotatable around the shaft member; and an elastic member that connects the rotating members in the axial direction and forms the roller surface in contact with the rubber sheet.

10. A belt manufacturing method for manufacturing a belt including a main belt material whose both widthwise ends are wrapped with rubber sheets, the belt manufacturing method comprising: a step of conveying the main belt material; and A folding step of folding, by means of folding rollers, regions of the rubber sheet that protrude outward from both ends in the width direction of the main belt material from one side of the main belt material to the other side of the main belt material, wherein, the folding rollers are arranged at both ends in the width direction of the main belt material, and the roller surfaces in contact with the rubber sheet are formed of elastic members that can elastically deform radially inward of the folding rollers.

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