Tire and method for manufacturing tire

Abstract

To provide a tire having a resin tire skeleton member and improving productivity.SOLUTION: A tire includes a resin tire skeleton member having a bead part 12, a side part 14 which is continuous to outside in a tire radial direction of the bead part, and a crown part 16 which is continuous to inside in a tire width direction of the side part, and a tread 34 which is arranged outside in the tire radial direction of the crown part. The crown part includes a belt layer 28 where one or a plurality of reinforcement cords are coated with a resin, and a resin film 37 which is wider than the belt layer and is arranged inside in the tire radial direction of the belt layer. The inner peripheral surface of the resin film constitutes the inner peripheral surface of the crown part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to tires and methods for manufacturing tires. [Background technology]

[0002] Patent Document 1 discloses a tire having a tire frame member made of resin. A belt layer including resin-coated cords, in which reinforcing cords are resin-coated, and a rubber tread are arranged on the radially outer side of a crown portion of the tire frame member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014-129380 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the tire disclosed in Patent Document 1 has a structure in which, after the tire frame member is formed, a belt layer is disposed on the outer side of the crown portion in the tire radial direction, and there is room for improvement in terms of productivity.

[0005] The present disclosure aims to improve productivity in tires having tire frame members made of resin. [Means for solving the problem]

[0006] A tire according to a first aspect of the present disclosure comprises a tire frame member made of resin, the tire frame member having bead portions, side portions connected to the outer side of the bead portions in the tire radial direction, and a crown portion connected to the inner side of the side portions in the tire width direction, and a tread disposed on the outer side of the crown portion in the tire radial direction, wherein the crown portion includes a belt layer having one or more reinforcing cords resin-coated therein, and a resin film that is wider than the belt layer and disposed on the inner side of the belt layer in the tire radial direction, and the inner surface of the resin film constitutes the inner surface of the crown portion.

[0007] In the tire of the first aspect, the belt layer and the resin film are included in the crown portion of the tire frame member, and the inner circumferential surface of the resin film arranged radially inward of the belt layer forms the inner circumferential surface of the crown portion. In the tire, when the resin tire frame member is molded, the crown portion can be formed in a state in which the belt layer and the resin film are arranged so that the inner circumferential surface of the resin film forms the inner circumferential surface of the crown portion. Therefore, since the belt layer is arranged in the crown portion when the tire frame member is molded, the tire has improved productivity compared to tires in which the belt layer is arranged radially outward of the crown portion after the tire frame member is formed.

[0008] A tire according to a second aspect of the present disclosure is the tire according to the first aspect, wherein the belt layer and the resin film are welded together.

[0009] In the tire of the second aspect, the belt layer and the resin film are welded together, so that the joining strength between the belt layer and the resin film is high, and the rigidity of the crown portion is improved.

[0010] A tire of a third aspect of the present disclosure is the tire of the first or second aspect, wherein the belt layer is formed by winding a coated cord, in which one or more of the reinforcing cords are resin-coated, spirally in the tire circumferential direction.

[0011] In the tire of the third aspect, a belt layer is formed by winding a resin-coated cord, which is one or more reinforcing cords, spirally around the tire circumferential direction. By including such a belt layer in the crown portion, the rigidity of the crown portion is improved, and tire performance is improved.

[0012] A tire according to a fourth aspect of the present disclosure is the tire according to any one of the first to third aspects, wherein the crown portion includes a resin layer disposed radially outward of the belt layers.

[0013] A tire having a resin tire frame member can be used as a retread tire (also called a retread tire) by removing the tread and replacing it with a new tread. However, if the tread is attached to the belt layer, there is a concern that the belt layer may be damaged when the tread is removed. In contrast, in the tire of the fourth aspect, the crown portion includes the belt layer and a resin layer arranged radially outward of the belt layer, so that it is possible to prevent the belt layer from being damaged when the tread is removed.

[0014] A tire according to a fifth aspect of the present disclosure is the tire according to the fourth aspect, wherein the resin layer and the tread are bonded together.

[0015] In the tire of the fifth aspect, the resin layer and the tread are bonded together, i.e., the outermost layer of the crown portion is formed of a resin layer. Therefore, in the tire of the fifth aspect, when the tread is peeled off while cutting the resin layer along the tire circumferential direction, the amount of parts required to repair the tire frame member after peeling off the tread can be reduced compared to a configuration in which the resin layer forms an intermediate layer of the crown portion.

[0016] A tire according to a sixth aspect of the present disclosure is the tire according to the fourth or fifth aspect, wherein the belt layer and the resin layer are welded together.

[0017] In the tire of the sixth aspect, the belt layer and the resin layer are welded together, so that the joining strength between the belt layer and the resin layer is high, and the rigidity of the crown portion is improved.

[0018] A tire according to a seventh aspect of the present disclosure is the tire according to any one of the fourth to sixth aspects, wherein the resin constituting the belt layer and the resin constituting the resin layer are the same type of resin.

[0019] In the tire of the seventh aspect, the resin constituting the belt layer and the resin constituting the resin layer are the same type of resin, so that the bonding strength between the belt layer and the resin layer is higher.

[0020] A tire according to an eighth aspect of the present disclosure is the tire according to any one of the fourth to seventh aspects, wherein the resin layer is made of only resin.

[0021] In the tire of the eighth embodiment, the resin layer is made of only resin, so that even if the resin layer is damaged when the tread is removed, it is easier to repair the resin layer compared to a configuration in which the resin layer includes a reinforcing member other than resin, for example.

[0022] A tire manufacturing method of a ninth aspect of the present disclosure includes the steps of: arranging a belt having one or more resin-coated reinforcing cords on the outer peripheral surface of a resin film; setting the belt arranged on the resin film and a vulcanized or semi-vulcanized tread in a cavity formed by a tire molding mold so that a gap is formed between them; and injecting molten resin into the cavity to mold a tire frame member having bead portions, side portions connected to the outer side of the bead portions in the tire radial direction, and a crown portion connected to the inner side of the side portions in the tire width direction.

[0023] In a ninth aspect of the tire manufacturing method, first, a belt having one or more resin-coated reinforcing cords is placed on the outer peripheral surface of a resin film. Next, the belt and a vulcanized or semi-vulcanized tread are set in a cavity formed by a tire mold so that a gap is formed between them. Then, molten resin is injected into the cavity to mold a tire frame member having a bead portion, a side portion, and a crown portion. The crown portion of the molded tire frame member includes a resin film, a belt layer, and a resin layer formed by the molten resin filled in the gap between the belt and the tread. The inner peripheral surface of the crown portion is also formed by the inner peripheral surface of the resin film. Then, a tread is disposed on the outer periphery of the crown portion of the tire frame member. In this way, in the tire manufacturing method described above, the crown portion of the tire frame member is formed by the molten resin with the resin film and belt layer set in the cavity. That is, in the above-described tire manufacturing method, the resin film and the belt layer are disposed in the crown portion when the tire frame member is molded, and therefore productivity is improved compared to a manufacturing method in which the belt layer is disposed on the tire radially outer side of the crown portion after the tire frame member is formed.

[0024] A tire manufacturing method according to a tenth aspect of the present disclosure is the tire manufacturing method according to the ninth aspect, wherein the molten resin is injected into the cavity from both outer sides of the tread in the tire width direction.

[0025] In the tire manufacturing method of the tenth aspect, the molten resin is injected into the cavity from both outer sides of the tread in the tire width direction, so that the cavity can be easily filled with the molten resin without any gaps.

[0026] A tire manufacturing method according to an eleventh aspect of the present disclosure is the tire manufacturing method according to the eighth or ninth aspect, wherein a portion of the tread contacts the belt and supports the belt when the tire is set in the cavity.

[0027] In the tire manufacturing method of the eleventh aspect, the tread and the belt are set in the cavity so that a portion of the tread is in contact with the belt and supports each other, thereby ensuring a gap between the tread and the belt, thereby enabling the manufacture of a high-quality tire with a resin layer having a predetermined thickness. [Effects of the Invention]

[0028] According to the present disclosure, productivity can be improved in tires having tire frame members made of resin. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a cross-sectional view taken along the tire width direction of a tire according to an embodiment of the present disclosure. [Figure 2A] FIG. 2 is an enlarged view of a portion indicated by an arrow 2AX in FIG. [Figure 2B] FIG. 2 is an enlarged view of a portion indicated by an arrow 2BX in FIG. [Figure 3] FIG. 3 is an enlarged view of the portion indicated by arrow 3X in FIG. [Figure 4] FIG. 2 is a side view of a part of the rubber chafer shown in FIG. 1 as seen from the inside of the tire. [Figure 5] 2 is a cross-sectional view showing a cross section of a bead portion at a support portion of the rubber chafer shown in FIG. 1 taken along the tire width direction. [Figure 6] FIG. 2 is a cross-sectional view taken along the tire width direction, showing the periphery of a through-hole in the tread shown in FIG. [Figure 7A] FIG. 2 is a cross-sectional view of the tread shown in FIG. 1 taken along the tire width direction. [Figure 7B] FIG. 7B is a plan view of the inner peripheral surface of the tread shown in FIG. 7A. [Figure 8] FIG. 2 is a cross-sectional view of a tire mold for molding the tire shown in FIG. [Figure 9] FIG. 9 is a cross-sectional view of the tire mold shown in FIG. 8 with a tread, a belt, a bead core, and a rubber chafer set in the cavity of the tire mold. [Figure 10]FIG. 10 is an enlarged view of a portion indicated by an arrow 10X in FIG. 9. [Figure 11] FIG. 2 is a cross-sectional view of a tire mold showing the periphery of a through hole of a tread set in a cavity. [Figure 12] FIG. 2 is a cross-sectional view of the tire mold showing the state in which the resin filled in the cavity has solidified. [Figure 13] FIG. 2 is a cross-sectional view taken along the tire width direction of a tire according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in each drawing are the same or similar components. Note that duplicated descriptions and reference numerals may be omitted in the embodiments described below. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships and ratios of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships and ratios of elements between multiple drawings do not necessarily correspond to the actual ones.

[0031] In the drawings, arrow TC indicates the tire circumferential direction, arrow TW indicates the tire width direction, and arrow TR indicates the tire radial direction. Hereinafter, the side closer to the tire rotational axis along the tire radial direction will be referred to as the "tire radially inner side," and the side farther from the tire rotational axis along the tire radial direction will be referred to as the "tire radially outer side." Meanwhile, the side closer to the tire equatorial plane CL along the tire width direction will be referred to as the "tire widthwise inner side," and the side farther from the tire equatorial plane CL along the tire width direction will be referred to as the "tire widthwise outer side." The method for measuring the dimensions of each part is based on the method described in the 2023 edition of the YEAR BOOK published by JATMA (Japan Automobile Tire Manufacturers Association).

[0032] As shown in FIG. 1, the tire 10 of this embodiment is, as an example, a pneumatic tire that is mounted on a standard rim (not shown) and filled with air, and has a cross-sectional shape that is approximately the same as that of a conventional pneumatic tire made of rubber (hereinafter referred to as a "rubber tire" as appropriate).

[0033] [Tire frame member 18] The tire 10 of this embodiment has an annular tire frame member 18 made of resin, which serves as a frame portion of the tire 10 .

[0034] The tire frame member 18 includes a pair of bead portions 12 spaced apart in the tire width direction, side portions 14 connected to the tire radially outer sides of the bead portions 12, and a crown portion 16 connected to the tire widthwise inner sides of the side portions 14 and connecting the tire radially outer ends of each side portion 14. The circumferential direction, width direction, and radial direction of the tire frame member 18 correspond to the tire circumferential direction, tire axial direction, and tire radial direction, respectively.

[0035] The tire frame member 18 is mainly formed of a thermoplastic resin 19. Details of this thermoplastic resin 19 will be described later.

[0036] (Bead part 12) As shown in Fig. 3, the bead portion 12 is a portion that fits onto a standard rim (not shown) via a rubber chafer 26. An annular bead core 20 extending along the tire circumferential direction is embedded inside the bead portion 12. The bead core 20 is formed by coating a bead cord 22 made of a metal (e.g., steel), organic fiber, or the like that is wound into an annular shape with a thermoplastic resin 24. Details of the thermoplastic resin 24 will be described later.

[0037] -Rubber Chafer 26- The rubber chafer 26 is disposed on the outer side of the bead portion 12 in the tire width direction. Specifically, the rubber chafer 26 is disposed on the outer side surface of the bead portion 12 in the tire width direction and the inner side surface in the tire radial direction, which are in contact with a standard rim (not shown). The rubber chafer 26 is formed of vulcanized rubber (rubber that has been vulcanized) and is joined to the bead portion 12. Specifically, the outer surface of the bead portion 12 (including the outer side surface of the bead portion 12 in the tire width direction and the inner side surface in the tire radial direction) and the inner surface of the rubber chafer 26 are bonded together. The bonding between the outer surface of the bead portion 12 and the inner surface of the rubber chafer 26 will be described in detail below.

[0038] A portion of the rubber chafer 26 is in contact with the bead core 20 embedded in the bead portion 12. As shown in Figures 3 and 5, the contact portion 27 of the rubber chafer 26 is a portion that protrudes from the inner surface 26A of the rubber chafer 26 in the tire width direction toward the bead core 20. As shown in Figure 4, a plurality of contact portions 27 are provided at intervals in the tire circumferential direction. Note that the contact portions 27 are preferably arranged at equal intervals in the tire circumferential direction.

[0039] As shown in FIGS. 3 and 5, the contact portion 27 supports the bead core 20 from the outer side in the tire width direction.

[0040] (Side part 14) 1, the side portion 14 is a portion that constitutes the side of the tire 10. The side portion 14 is gently curved from the bead portion 12 toward the crown portion 16 so as to be convex outward in the tire width direction.

[0041] As shown in Fig. 5, the thickness of the side portion 14 increases in a portion corresponding to the end 26B of the rubber chafer 26 on the outer side in the tire radial direction. Specifically, the thickness of the side portion 14 is constant from the portion on the crown portion 16 side to the vicinity of the portion corresponding to the end 26B of the rubber chafer 26, and increases in the portion corresponding to the end 26B of the rubber chafer 26. Therefore, a step is formed on the outer surface of the side portion 14 in front of the portion corresponding to the end 26B of the rubber chafer 26 (outside in the tire radial direction) due to the increase in thickness. Note that, in this embodiment, the portion of the side portion 14 corresponding to the end 26B of the rubber chafer 26 is the portion of the side portion 14 on the bead portion 12 side.

[0042] (Crown part 16) As shown in Fig. 1, the crown portion 16 is a portion that supports a tread 34 (described later) disposed radially outward in the tire. In this embodiment, the outer peripheral surface of the crown portion 16 is formed flat along the tire width direction. Note that the symbol CW in Fig. 1 indicates the width of the crown portion 16 along the tire width direction.

[0043] -Resin film 37- As shown in FIGS. 1 , 2A, and 2B , the crown portion 16 includes a belt layer 28 in which one or more reinforcing cords 30 are resin-coated, and a resin film 37 that is wider than the belt layer 28 and arranged on the radially inner side of the belt layer 28. The resin film here refers to a film with a thickness of less than 1 mm. The crown portion 16 also includes a resin layer 29 arranged on the radially outer side of the belt layer 28. In the present embodiment, as an example, the crown portion 16 has a three-layer structure, with the resin film 37 constituting the inner layer of the crown portion 16 (the layer on the radially inner side of the tire) and the resin layer 29 constituting the outer layer of the crown portion 16 (the layer on the radially outer side of the tire). Therefore, in the tire 10, the inner circumferential surface of the resin film 37 constitutes the inner circumferential surface of the crown portion 16, and the outer circumferential surface of the resin layer 29 constitutes the outer circumferential surface of the crown portion 16.

[0044] 2B , both end portions 37A of the resin film 37 in the tire width direction are located outward in the tire width direction from both end portions 28A of the belt layer 28 in the tire width direction. That is, the width of the resin film 37 is wider than the width of the belt layer 28.

[0045] The belt layer 28 and the resin film 37 may be welded together. As an example, the resin film 37 in this embodiment is made of the same type of resin as the thermoplastic resin 19. It is preferable that the resin constituting the resin film 37 is a resin having the same components as the thermoplastic resin 19. However, the present disclosure is not limited to this configuration, and the resin film 37 may be made of a resin different from the thermoplastic resin 19.

[0046] The resin film 37 of this embodiment has, for example, a cylindrical shape with a constant diameter.

[0047] -Belt layer 28- As shown in Fig. 1, the belt layer 28 is formed by spirally winding a coated cord, in which one or more reinforcing cords 30 are coated with a thermoplastic resin 32, in the circumferential direction of the tire. In other words, the belt layer 28 is formed by coating a reinforcing cord 30 made of a metal (e.g., steel), organic fiber, or the like, wound in an annular shape with the thermoplastic resin 32. In the present embodiment, as an example, the belt layer 28 is formed by spirally winding a coated cord, in which two reinforcing cords 30 are coated with the thermoplastic resin 32, in the circumferential direction of the tire (see Fig. 2A). Details of the thermoplastic resin 32 used in the belt layer 28 will be described later.

[0048] The belt layer 28 of the present embodiment has, for example, a cylindrical shape with a constant diameter.

[0049] 1, the range from the end 28A of the belt layer 28 on the outer side in the tire width direction to the side portion 14 is formed only from the thermoplastic resin 19. Specifically, the range from the end 28A of the belt layer 28 to the end of the side portion 14 on the inner side in the tire radial direction is formed only from the thermoplastic resin 19.

[0050] -Resin layer 29- 1, the resin layer 29 is made of only a resin. Specifically, the resin layer 29 is made of a single resin. In the present embodiment, as an example, the resin layer 29 is made of only a thermoplastic resin 19.

[0051] The resin layer 29 is also bonded to the tread 34. Specifically, the outer peripheral surface of the tire frame member 18, including the outer peripheral surface of the resin layer 29, is bonded to the inner peripheral surface of the tread 34. The bonding between the outer peripheral surface of the tire frame member 18 and the inner peripheral surface of the tread 34 will be described in detail later.

[0052] The belt layer 28 and the resin layer 29 are welded together. Specifically, the outer peripheral surface of the belt layer 28 and the inner peripheral surface of the resin layer 29 are welded together. More specifically, the thermoplastic resin 32 constituting the belt layer 28 and the thermoplastic resin 19 constituting the resin layer 29 are welded together. In the present embodiment, as an example, the thermoplastic resin 32 and the thermoplastic resin 19 are the same type of resin, more specifically, resins having the same components, but they may be different types of resins.

[0053] (Tread 34) 1, a tread 34 made of vulcanized rubber (rubber that has been vulcanized) is disposed on the tire radially outer side of the crown portion 16 of the tire frame member 18. The inner peripheral surface of the tread 34 is bonded to the outer peripheral surface of the tire frame member 18, including the crown portion 16.

[0054] A tread pattern (not shown) is formed on the outer peripheral surface of the tread 34 at the contact surface with the road surface.

[0055] The inner peripheral surface of the tread 34 is flat. As shown in Fig. 1 and Fig. 2A, the inner peripheral surface of the tread 34 is provided with a plurality of protrusions 35 that protrude toward the outer peripheral surface of the belt layer 28. The plurality of protrusions 35 penetrate the resin layer 29. The tips of the protrusions 35 are in contact with the outer peripheral surface of the belt layer 28. That is, in this embodiment, the protrusions 35, which are part of the tread 34, are in contact with the outer peripheral surface of the belt layer 28.

[0056] The plurality of protrusions 35 are formed to a fixed height so as to maintain a fixed distance between the tread 34 and the belt layer 28. The height of the protrusions 35 is preferably set so that molten resin can easily move between the tread 34 and the belt layer 28 during tire molding.

[0057] 7A and 7B, the multiple protrusions 35 are provided at intervals in the tire circumferential direction and the tire width direction. The multiple protrusions 35 are preferably provided at equal intervals in the tire circumferential direction. The multiple protrusions 35 are preferably provided at equal intervals in the tire width direction. In this embodiment, as an example, the tire circumferential positions of the protrusions 35 located on both end sides of the tread 34 in the tire width direction are offset from the tire circumferential positions of the protrusions 35 located on the center side in the tire width direction. Specifically, the protrusions 35 located on both end sides of the tread 34 in the tire width direction are located at the center between the protrusions 35 located on the center side in the tire width direction.

[0058] As shown in FIG. 7B , the tread 34 is provided with a plurality of through holes 36 penetrating in the tire radial direction. These through holes 36 are provided in the tread 34 at intervals in the tire circumferential direction. These through holes 36 are used, for example, as gas vent holes during tire molding. A plurality of through holes 36 may be formed along the injection direction of molten resin from a gate 46 of a mold 40, which will be described later. In FIG. 7B , as an example, three through holes 36 are formed at equal intervals in the injection direction of molten resin from the gate 46. Of the three through holes 36, two are formed on one side of the tire circumferential direction and two are formed on the other side, equally spaced from the through hole 36 on the center line of the tread 34. Note that in this embodiment, the center line of the tread 34 coincides with the tire equatorial plane CL, and is therefore denoted by the symbol CL in FIGS. 7A and 7B . The positions of the through holes 36 formed in the tread 34 are not limited to those described above, and are preferably set to optimal positions depending on the position of the gate 46 for molten resin, the injection pressure, and the like.

[0059] The plurality of through holes 36 are each filled with the thermoplastic resin 19 that forms the resin layer 29. The thermoplastic resin 19 that fills the through holes 36 protrudes from the outer peripheral surface of the resin layer 29. In other words, the molten thermoplastic resin 19 that forms the resin layer 29 during tire formation enters the through holes 36, and the through holes 36 are filled with the thermoplastic resin 19 after the resin has solidified.

[0060] As shown in FIG. 2A, in the tire 10 of this embodiment, the resin thickness dimension t1 between the tread 34 and the reinforcing cord 30 is thicker than the resin thickness dimension t2 between the inner circumferential surface of the crown portion 16 and the reinforcing cord 30.

[0061] As described above, in the tire 10 of this embodiment, the range from the outer end 28A of the belt layer 28 in the tire width direction to the inner end of the side portion 14 in the tire radial direction is formed only from the thermoplastic resin 19. When the thickness of the thermoplastic resin 19 in the above range of the tire frame member 18 is T (see FIG. 1 ), the product of the thickness T and the elastic modulus of the thermoplastic resin 19 is preferably set to 200 MPa·mm or more and 600 MPa·mm or less, and more preferably set to 250 MPa·mm or more and 450 MPa·mm or less.

[0062] Next, the thermoplastic resin 19 used in the tire frame member 18, the thermoplastic resin 24 used in the bead core 20, and the thermoplastic resin 32 used in the belt layer 28 will be described below.

[0063] Thermoplastic resins (including thermoplastic elastomers) are polymeric compounds that soften and flow as the temperature rises, and become relatively hard and strong when cooled.

[0064] In this specification, a distinction is made between thermoplastic elastomers, which are polymeric compounds that soften and flow with increasing temperature, become relatively hard and strong when cooled, and have rubber-like elasticity, and non-elastomer thermoplastic resins, which are polymeric compounds that soften and flow with increasing temperature, become relatively hard and strong when cooled, and do not have rubber-like elasticity.

[0065] Examples of thermoplastic resins (including thermoplastic elastomers) include polyolefin thermoplastic elastomers (TPO), polystyrene thermoplastic elastomers (TPS), polyamide thermoplastic elastomers (TPA), polyurethane thermoplastic elastomers (TPU), polyester thermoplastic elastomers (TPC), and dynamically crosslinked thermoplastic elastomers (TPV), as well as polyolefin thermoplastic resins, polystyrene thermoplastic resins, polyamide thermoplastic resins, and polyester thermoplastic resins.

[0066] The thermoplastic resin may have a deflection temperature under load (under a load of 0.45 MPa) of 78°C or higher as specified in ISO 75-2 or ASTM D648, a tensile yield strength of 10 MPa or higher as specified in JIS K7113, a tensile elongation at break of 50% or higher as specified in JIS K7113, and a Vicat softening temperature (method A) of 130°C as specified in JIS K7206. A polyester resin may be used instead of the polyester thermoplastic elastomer (TPC).

[0067] In this embodiment, the thermoplastic resin 19, the thermoplastic resin 24, and the thermoplastic resin 32 are made of a polyester thermoplastic elastomer (TPC).

[0068] Next, a method for manufacturing a tire according to this embodiment will be described. First, a mold 40 used for manufacturing the tire will be described.

[0069] [Mold] Fig. 8 shows a cross-sectional view of a mold 40 as an example of a tire mold for molding the tire 10 of this embodiment. The mold 40 includes an outer mold 42 for molding the outer surface side of the tire, and an inner mold (in other words, a core) 44 for molding the inner surface side of the tire. A cavity S (space) for molding the tire 10 is formed between the outer mold 42 and the inner mold 44. Arrows TW and TR shown in Figs. 8 to 12 indicate the tire width direction and tire radial direction of the tire 10 molded by the mold 40.

[0070] The outer mold 42 includes a first mold 42A for molding the outer peripheral side of the tire, and a pair of second molds 42B for molding the side portions of the tire.

[0071] The first mold 42A is composed of a plurality of blocks divided in the tire circumferential direction of the tire 10 to be molded by the mold 40. Note that Figs. 8, 9, and 12 show a cross section of one of the blocks constituting the first mold 42A. As shown in Fig. 8, each block is configured to be movable in the tire radial direction. Specifically, each block is configured to be movable in the tire radial direction, that is, in the direction approaching and moving away from the inner mold 44. Note that the direction in which each block approaches the inner mold 44 is also referred to as the mold closing direction of the first mold 42A, and the direction in which each block moves away from the inner mold 44 is also referred to as the mold opening direction of the first mold 42A.

[0072] The pair of second dies 42B are configured to be movable in the tire width direction. Specifically, as shown in Fig. 8, the pair of second dies 42B are configured to be movable in the tire width direction, i.e., in directions approaching and moving away from the inner die 44. The direction in which the second dies 42B approach the inner die 44 is also referred to as the die closing direction of the second die 42B, and the direction in which the second dies 42B move away from the inner die 44 is also referred to as the die opening direction of the second die 42B.

[0073] The first die 42A of the outer mold 42 has gates 46 for injecting molten resin into the cavity S at positions on both outer sides of the tread 34 in the tire width direction in the cavity S. Specifically, each block constituting the first die 42A has a gate 46. Note that the pair of gates 46 on both outer sides in the tire width direction may be provided in one block, or multiple pairs spaced apart in the tire circumferential direction.

[0074] The inner mold 44 is provided with protruding holding portions 48 that hold the bead cores 20. Specifically, the holding portions 48 protrude from the inner mold 44, and recesses 48A into which the bead cores 20 fit are formed at the protruding tips. The bead cores 20 are held by fitting into these recesses 48A. Furthermore, a plurality of holding portions 48 are provided on the inner mold 44 at intervals in the circumferential direction (the same direction as the tire circumferential direction). It is preferable that the holding portions 48 are provided on the inner mold 44 at equal intervals.

[0075] [Tire manufacturing method] Next, a manufacturing process of the tire 10 of this embodiment will be described.

[0076] First, the tread 34, resin film 37, belt layer 28, rubber chafer 26, and bead core 20 that constitute the tire 10 are prepared. In this embodiment, as an example, the belt layer 28 is formed on the resin film 37 by spirally winding a coated cord, which is formed by coating one or more reinforcing cords with resin on the outer peripheral surface of the cylindrically formed resin film 37, in the circumferential direction of the resin film 37.

[0077] In the present embodiment, as an example, the tread 34 and the rubber chafer 26 are formed of vulcanized rubber. The tread 34 and the rubber chafer 26 may be formed of semi-vulcanized rubber. In this case, the tread 34 and the rubber chafer 26 may be vulcanized after the tire frame member 18 is molded. The belt layer 28 is an example of a belt in the present disclosure.

[0078] The tread 34 used in this embodiment is subjected to a primer treatment with a chlorine compound at the portion that comes into contact with the molten thermoplastic resin 19 .

[0079] Furthermore, the rubber chafer 26 used in this embodiment is subjected to a primer treatment with a chlorine compound at the portion that comes into contact with the molten thermoplastic resin 19 .

[0080] Next, as shown in FIG. 9 , the tread 34, the resin film 37, the belt layer 28, the rubber chafer 26, and the bead core 20 are placed in predetermined positions in the cavity S of the mold 40. Specifically, the tread 34 and the belt layer 28 are set in the cavity S so that a gap is formed between the tread 34 and the belt layer 28. More specifically, the tread 34 is set with a portion of the tread 34 in contact with the belt layer 28 so that a gap is formed between the tread 34 and the belt layer 28. In the present embodiment, as an example, the tread 34 and the belt layer 28 are set in the cavity S with the tips of the multiple protrusions 35 of the tread 34 in contact with the outer peripheral surface of the belt layer 28. This ensures a gap between the tread 34 and the belt layer 28. Note that, as a method for setting the tread 34 and the belt layer 28 in the cavity S, there may be mentioned a method in which the tread 34 is held in the first mold 42A, and the resin film 37 on which the belt layer 28 is disposed is held in the inner mold 44, and the first mold 42A is then closed to set the tread 34, the belt layer 28, and the resin film 37 in the cavity S. Note that the present disclosure is not limited to this setting method, and, for example, the resin film 37 on which the belt layer 28 is disposed may be held in the inner mold 44, and the tips of the multiple protrusions 35 may be brought into contact with the outer peripheral surface of the belt layer 28 to hold the tread 34, and the first mold 42A may be closed to set the tread 34, the belt layer 28, and the resin film 37 in the cavity S, or another method may be used.

[0081] 10 , the bead core 20 is fitted into and held in the recesses 48A of the multiple holding portions 48. Then, the rubber chafer 26 and the bead core 20 are set in the cavity S with a portion of the rubber chafer 26 in contact with the bead core 20 from the side opposite the multiple holding portions 48. Specifically, the rubber chafer 26 and the bead core 20 are set in the cavity S with the bead core 20 sandwiched and held between the multiple holding portions 48 and the contact portion 27 of the rubber chafer 26 in the clamping direction of the second mold 42B. One method for setting the bead core 20 and the rubber chafer 26 in the cavity S is to hold the bead core 20 with the multiple holding portions 48 of the inner mold 44, and clamp the pair of second molds 42B with the rubber chafer 26 held therein, thereby setting the bead core 20 and the rubber chafer 26 in the cavity S. Note that the present disclosure is not limited to this setting method.

[0082] Next, molten thermoplastic resin 19 for forming the tire frame member 18 is injected from multiple gates 46 into the cavity S in which the tread 34, resin film 37, belt layer 28, rubber chafer 26, and bead core 20 have been set. Specifically, the molten thermoplastic resin 19 is injected into the cavity S from both outer sides of the tread 34 in the tire width direction. When the thermoplastic resin 19 is injected into the cavity S from each gate 46, gas is generated. The generated gas is discharged from the through holes 36 formed in the tread 34, as shown in FIG. 11 . Note that as the molten thermoplastic resin 19 fills the cavity S due to injection pressure, some of it enters and fills the through holes 36. This fills the through holes 36 in the tread 34.

[0083] The cavity S is then filled with the injected molten thermoplastic resin 19. Here, the tread 34 has been subjected to a primer treatment with a chlorine compound at the portion that comes into contact with the molten thermoplastic resin 19, so after the resin solidifies, the tread 34 and the thermoplastic resin 19 are directly and firmly bonded (adhered) together. Note that the term "directly bonded (adhered)" used here means that the rubber member and the thermoplastic resin are in direct contact with each other and are bonded together without any bonding material such as an adhesive being interposed between them.

[0084] In addition, since the rubber chafer 26 is treated with a primer of a chlorine compound at the portion that comes into contact with the molten thermoplastic resin 19, the rubber chafer 26 and the thermoplastic resin 19 are directly and firmly bonded (adhered) together after the resin solidifies.

[0085] Then, when the thermoplastic resin 19 solidifies, the molding of the tire 10 is completed. Thereafter, the first mold 42A and the second mold 42B are each moved in the mold opening direction, and the tire 10 is removed from the inner mold 44, thereby completing the production of the tire 10.

[0086] Next, the effects of this embodiment will be described. In the tire 10 of this embodiment, the belt layer 28 and the resin film 37 are included in the crown portion 16 of the tire frame member 18, and the inner circumferential surface of the resin film 37 arranged radially inward of the belt layer 28 forms the inner circumferential surface of the crown portion 16. That is, in the tire 10, when the resin tire frame member 18 is molded, the crown portion 16 can be formed in a state in which the belt layer 28 and the resin film 37 are arranged such that the inner circumferential surface of the resin film 37 forms the inner circumferential surface of the crown portion 16. Therefore, in the tire 10, the belt layer 28 is arranged in the crown portion 16 when the tire frame member 18 is molded, and therefore productivity is improved compared to tires in which a belt layer is arranged radially outward of the crown portion after the tire frame member is formed.

[0087] Furthermore, in the tire 10 of this embodiment, the width of the resin film 37 disposed on the inner side of the belt layer 28 in the tire radial direction is wider than that of the belt layer 28. Then, both end portions 37A of the resin film 37 are positioned outer in the tire width direction than both end portions 28A of the belt layer 28. Therefore, in the tire 10, compared to a tire in which the width of the resin film 37 is narrower than the width of the belt layer 28, it is possible to reduce the rigidity step near the end portions 28A of the belt layer 28 and to suppress the occurrence of cracks near the end portions 28A.

[0088] In the tire 10 of the present embodiment, the belt layer 28 and the resin film 37 are welded together, which increases the bonding strength between the belt layer 28 and the resin film 37 and improves the rigidity of the crown portion 16. In addition, an effect of suppressing cracks from occurring between the belt layer 28 and the resin film 37 can also be obtained.

[0089] In the tire 10 of this embodiment, the belt layer 28 is formed by spirally winding a coated cord in the tire circumferential direction, the coated cord being formed by resin-coating one or more reinforcing cords 30. By including such a belt layer 28 in the crown portion 16, the rigidity of the crown portion 16 is improved, and tire performance is improved.

[0090] A tire having a tire frame member made of resin can be used as a retread tire (also called a retread tire) by removing the tread and replacing it with a new tread. However, if the tread is attached to the belt layer, there is a concern that the belt layer may be damaged when the tread is removed. In contrast, in the tire 10 of this embodiment, the crown portion 16 includes the belt layer 28 and the resin layer 29, and therefore, damage to the belt layer 28 when the tread 34 is removed can be suppressed.

[0091] In the tire 10 of this embodiment, the resin layer 29 and the tread 34 are joined together, that is, the outermost layer of the crown portion 16 is formed of the resin layer 29. Therefore, in the tire 10, when the tread 34 is peeled off while cutting the resin layer 29 along the tire circumferential direction, the amount of parts required to repair the tire frame member 18 after the tread 34 is peeled off can be reduced, compared to a configuration in which a resin layer forms an intermediate layer of the crown portion 16.

[0092] In the tire 10 of this embodiment, the belt layer 28 and the resin layer 29 are welded together, so that the joining strength between the belt layer 28 and the resin layer 29 is high, and the rigidity of the crown portion 16 is improved.

[0093] In the tire 10 of the present embodiment, the resin constituting the belt layer 28 and the resin constituting the resin layer 29 are of the same type, so that the bonding strength between the belt layer 28 and the resin layer 29 is increased.

[0094] In the tire 10 of this embodiment, the resin layer 29 is made of only resin, so that even if the resin layer 29 is damaged when the tread 34 is peeled off, it is easier to repair the resin layer 29 compared to a configuration in which the resin layer 29 includes other components besides resin, for example.

[0095] Furthermore, in the tire 10 of this embodiment, the tire frame member 18 is formed only from the thermoplastic resin 19 in a region from the end 28A of the belt layer 28 in the tire width direction to the side portion 14. Therefore, the product of the thickness T of the resin (thermoplastic resin 19) of the tire frame member 18 in this region and the elastic modulus of the resin (thermoplastic resin 19) is set to 200 MPa·mm or more and 600 MPa·mm or less. Setting the product of the resin thickness T and the elastic modulus in the above range to 200 MPa·mm or more can suppress local deformation of the tire frame member 18 in the above range when the tire 10 rolls. Setting the product of the resin thickness T and the elastic modulus to 600 MPa·mm or less can suppress cracks from occurring in the above range of the tire frame member 18. Even if a crack occurs in the above range, its propagation can be suppressed. That is, in the tire 10, by setting the product of the resin thickness T and the elastic modulus to 200 MPa·mm or more and 600 MPa·mm or less, local deformation is suppressed within the above range of the tire frame member 18, thereby improving pressure resistance performance, compared to a tire in which, for example, only the elastic modulus of the resin is set, and further, crack generation and crack propagation are suppressed within the above range of the tire frame member 18, thereby improving reliability during rolling.

[0096] In the tire 10 of this embodiment, by setting the product of the resin thickness T and the elastic modulus to 250 MPa·mm or more and 450 MPa·mm or less, the pressure resistance performance and rolling reliability of the tire frame member 18 within the above range are further improved.

[0097] In the tire 10 of this embodiment, a part of the tread 34 (the protrusions 35) is in contact with the outer peripheral surface of the belt layer 28, and therefore the interface between the tread 34 and the crown portion 16 is not linear along the tire width direction but has a stepped shape in the tire width direction. Specifically, the protrusions 35 extend from the inner peripheral surface of the tread 34 toward the belt layer 28, and therefore the interface between the tread 34 and the crown portion 16 includes an interface along the inner peripheral surface of the tread 34 and an interface along the outer peripheral surfaces of the protrusions 35. Here, the interface along the inner peripheral surface of the tread 34 is along the tire width direction, but the interfaces along the outer peripheral surfaces of the multiple protrusions 35 are along a direction intersecting the tire width direction (a direction perpendicular to the tire width direction in this embodiment), and therefore the interface between the tread 34 and the crown portion 16 has a stepped shape in the tire width direction. Thus, in the tire 10, compared to a tire in which the interface between the tread 34 and the crown portion 16 is linear along the tire width direction, the stepped shape of the interface suppresses peeling at the interface and the progression of the peeled portion even when a shear force in the tire width direction is applied to the interface between the tread 34 and the crown portion 16. Therefore, with the tire 10, it is possible to suppress peeling of the tread 34 from the crown portion 16 in the tire frame member 18.

[0098] In the tire 10 of this embodiment, a plurality of protrusions 35 extending toward the outer peripheral surface of the belt layer 28 is provided on the inner peripheral surface of the tread 34, and the plurality of protrusions 35 penetrate the resin layer 29. Therefore, in the tire 10, the interface between the tread 34 and the crown portion 16 has a shape with a plurality of steps in the tire width direction. This makes it possible to further suppress peeling of the tread 34 from the crown portion 16 of the tire frame member 18 in the tire 10.

[0099] In the tire 10 of this embodiment, multiple protrusions 35 are spaced apart in the tire circumferential direction and tire width direction, so that even if shear forces in the tire width direction and tire circumferential direction are applied to the interface between the tread 34 and the crown portion 16, the stepped shape of the interface can prevent the tread 34 from peeling off from the crown portion 16.

[0100] In the tire 10 of this embodiment, the through holes 36 provided in the tread 34 are filled with the thermoplastic resin 19 that forms the resin layer 29. Therefore, compared to a tire in which the through holes 36 are not filled with resin, for example, it is possible to visually confirm that the resin is filled without any gaps in the part that will become the resin layer 29 during manufacturing.

[0101] In the tire 10 of this embodiment, a portion of the rubber chafer 26 is in contact with the bead core 20 embedded in the bead portion 12. That is, in the tire 10, the bead portion 12 can be formed with a portion of the rubber chafer 26 in contact with the bead core 20 when the resin tire frame member 18 is molded. In the tire 10, the rubber chafer 26 is disposed in the bead portion 12 when the tire frame member 18 is molded. Therefore, compared to a tire in which the rubber chafer 26 is attached to the bead portion 12 after the tire frame member 18 is formed, there is a higher degree of freedom in the shape of the rubber chafer 26 and it is easier to ensure the positioning accuracy of the rubber chafer 26. Therefore, the tire has improved air sealing performance when mounted on a standard rim.

[0102] In the tire 10 of this embodiment, the rubber chafer 26 has multiple contact portions 27 that come into contact with the bead core 20 spaced apart around the tire, making it possible to prevent the bead core 20 from shifting in position due to the injection pressure when molding the tire frame member 18.

[0103] In the tire 10 of this embodiment, the contact portion 27 supports the bead core 20 from the outside in the tire width direction, so there is no need to extend the rubber chafer 26 to a predetermined height inside the bead portion 12, and the amount of rubber that makes up the rubber chafer 26 can be reduced.

[0104] In the tire 10 of this embodiment, the thickness of the side portion 14 increases in a portion corresponding to the end 26B of the rubber chafer 26 on the outer side in the tire radial direction, thereby ensuring strength in the portion of the side portion 14 on the bead portion 23 side. Also, in the tire 10, as shown in Fig. 10, the end 26B of the rubber chafer 26 fits into the cavity S so that the thickness of the side portion 14 increases in a portion corresponding to the end 26B of the rubber chafer 26, thereby preventing the injected molten resin from entering between the rubber chafer 26 and the second die 42B.

[0105] Furthermore, in the tire 10 of this embodiment, the portions of the tread 34 and the rubber chafer 26 that come into contact with the thermoplastic resin 19 are primed, and therefore, compared to when the primer treatment is not applied, the tread 34 and the rubber chafer 26 can be directly and firmly bonded (adhered) to the thermoplastic resin 19 that forms the tire frame member 18. Note that, "directly bonded" here means that the rubber member and the thermoplastic resin come into direct contact with each other and are bonded without an adhesive or the like being interposed between them.

[0106] Furthermore, in the tire 10 of this embodiment, the belt layer 28, the rubber chafer 26, and the bead core 20 are bonded to the thermoplastic resin 19 by bringing the molten thermoplastic resin 19 that forms the tire frame member 18 into contact with the belt layer 28, the rubber chafer 26, and the bead core 20, thereby improving productivity compared to the case where the belt layer 28, the rubber chafer 26, and the bead core 20 are bonded to the tire frame member 18 that has been molded in advance (hardened thermoplastic resin) using an adhesive.

[0107] 2A , in the tire 10 of this embodiment, the resin thickness dimension t1 between the tread 34 and the reinforcement cord 30 of the belt layer 28 is set to be thicker than the resin thickness dimension t2 of the reinforcement cord 30 on the side opposite to the tread 34, thereby increasing the distance from the tread 34 to the longitudinal ends of the reinforcement cord 30 of the belt layer 28. This makes it difficult for force acting from the tread surface side of the tread 34 to act near the ends of the reinforcement cord 30, thereby suppressing peeling and damage to the resin (thermoplastic resin 19, thermoplastic resin 32) around the longitudinal ends of the reinforcement cord 30.

[0108] In the manufacturing method of the tire 10 of this embodiment, the belt layer 28 arranged on the resin film 37 and the tread 34 are set in the cavity S so that a gap is formed between them. In this embodiment, the belt layer 28 and the tread 34 are set in the cavity S with a portion of the tread 34 in contact with the belt layer 28 so that a gap is formed between them. In addition, the bead cores 20 held by the holding portions 48 and the rubber chafers 26 are set with a portion of the bead cores 20 in contact with the bead cores 20 from the side opposite the holding portions 48. Next, a molten thermoplastic resin 19 is injected into the cavity S to form the tire frame member 18.

[0109] The crown portion 16 of the molded tire frame member 18 includes a resin film 37, a belt layer 28, and a resin layer 29 formed of molten thermoplastic resin 19 filled in gaps between the belt layer 28 and the tread 34. The inner circumferential surface of the crown portion 16 is formed by the inner circumferential surface of the resin film 37. The tread 34 is disposed on the outer periphery of the crown portion 16 of the tire frame member 18. In this manner, in the manufacturing method of the tire 10, the crown portion 16 of the tire frame member 18 is formed from the molten thermoplastic resin 19 with the belt layer 28 set in the cavity S. That is, in the above manufacturing method, the belt layer 28 is disposed in the crown portion 16 when the tire frame member 18 is molded, and therefore productivity is improved compared to a manufacturing method in which the belt layer 28 is disposed on the tire radially outer side of the crown portion 16 after the tire frame member 18 is formed.

[0110] Furthermore, in the molded tire frame member 18, a portion of the tread 34 is in contact with the outer peripheral surface of the belt layer 28, so the interface between the tread 34 and the crown portion 16 is not linear along the tire width direction but has a stepped shape in the tire width direction. Therefore, in the tire 10 manufactured by the above manufacturing method, the stepped shape of the interface suppresses interfacial peeling and the progression of the peeled portion even when a shear force in the tire width direction is applied to the interface between the tread 34 and the crown portion 16, compared to a tire in which the interface between the tread 34 and the crown portion 16 is linear along the tire width direction. Therefore, according to the manufacturing method of the tire 10, it is possible to manufacture a tire 10 that can suppress peeling of the tread 34 from the crown portion 16 of the tire frame member 18.

[0111] Furthermore, bead cores 20 are embedded in the bead portions 12 of the molded tire frame member 18, and rubber chafers 26 are disposed in contact with the bead cores 20. In this manner, in the manufacturing method of the tire 10, the bead portions 12 are formed with portions of the rubber chafers 26 in contact with the bead cores 20 when the resin tire frame member 18 is molded. Therefore, in the manufacturing method of the tire 10, the rubber chafers 26 are disposed in the bead portions 12 when the tire frame member 18 is molded. Therefore, compared to tire manufacturing methods in which the rubber chafers 26 are attached to the bead portions 12 after the tire frame member 18 is formed, there is a higher degree of freedom in the shape of the rubber chafers 26 and it is easier to ensure the positioning accuracy of the rubber chafers 26. Therefore, a tire manufactured by the above tire manufacturing method has improved air sealing performance when mounted on a standard rim.

[0112] In the manufacturing method of the tire 10 of this embodiment, the molten thermoplastic resin 19 is injected into the cavity S from both outer sides of the tread 34 in the tire width direction, making it easy to fill the cavity S with the molten thermoplastic resin 19 without leaving any gaps.

[0113] In the manufacturing method of the tire 10 of this embodiment, the tread 34 and the belt layer 28 are set in the cavity S so that a portion of the tread 34 contacts the belt layer 28 and supports each other, thereby ensuring a gap between the tread 34 and the belt layer 28. This makes it possible to manufacture a high-quality tire in which the resin layer 29 has a predetermined thickness.

[0114] In the manufacturing method of the tire 10 of the present embodiment, the through holes 36 are provided in the tread 34, so that gas generated when the molten thermoplastic resin 19 is injected into the cavity S can be discharged to the outside through the through holes 36. This makes it easy to fill the gap between the tread 34 and the belt layer 28 with the molten thermoplastic resin 19.

[0115] In the manufacturing method of the tire 10 of this embodiment, the bead core 20 is sandwiched and held between the holding portion 48 and a part of the rubber chafer 26 in the mold clamping direction of the second mold 42B, thereby preventing the position of the bead core 20 from shifting due to the injection pressure of the molten thermoplastic resin 19.

[0116] [Other embodiments] The above describes one example of an embodiment of the present disclosure, but the embodiment of the present disclosure is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit of the present disclosure.

[0117] In the above-described embodiment, a portion of the tread 34 (the protrusions 35) is in contact with the outer peripheral surface of the belt layer 28, but the present disclosure is not limited to this configuration. For example, a portion of the tread 34 may not be in contact with the outer peripheral surface of the belt layer 28. Specifically, as in the tire 100 shown in FIG. 13 , the protrusions 35 may not be provided on the inner peripheral surface of the tread 34. In this case, the tread 34 can be easily peeled off by, for example, melting the resin layer 29 and cutting it along the tire circumferential direction using an ultrasonic cutter or the like. In this way, when the protrusions 35 are not provided on the inner peripheral surface of the tread 34, the retreadability of the tire 100 is improved. Note that, here, retreadability refers to the ease with which the tread 34 can be peeled off. Furthermore, when the protrusions 35 are not provided, peeling of the tread 34 from the tips of the protrusions 35 can also be prevented.

[0118] In the above-described embodiment, the crown portion 16 has a two-layer structure of the belt layer 28 and the resin layer 29, but the present disclosure is not limited to this configuration. For example, the crown portion 16 may be formed of only the belt layer. Specifically, in FIG. 2A , the resin layer 29 may be omitted by forming a belt layer in which the resin thickness dimension t1 above the reinforcement cord 30 of the coated cord is greater than the resin thickness dimension t2. In this case, it is preferable to apply a primer treatment to the flat inner peripheral surface of the tread 34 and then join the belt layer 28, the outer peripheral surface of which has been melted, to the inner peripheral surface of the tread 34. [Explanation of symbols]

[0119] 10···Tire, 12···Bead portion, 14···Side portion, 16···Crown portion, 18···Tire frame member, 19···Thermoplastic resin, 37···Resin film, 28···Belt layer (an example of a belt), 29···Resin layer, 30···Reinforcing cord, 32···Thermoplastic resin, 34···Tread, mold 40 (an example of a tire molding mold), 100···Tire, 110···Tire, S···Cavity, TC···Tire circumferential direction, TR···Tire radial direction, TW···Tire width direction.

Claims

1. a tire frame member made of resin, the tire frame member having bead portions, side portions continuous with the bead portions on the outer side in the tire radial direction, and a crown portion continuous with the side portions on the inner side in the tire width direction; a tread disposed on the outer side of the crown portion in the tire radial direction; Equipped with the crown portion includes a belt layer in which one or more reinforcing cords are resin-coated, and a resin film that is wider than the belt layer and is arranged on the inner side of the belt layer in the tire radial direction, The tire, wherein the inner circumferential surface of the resin film constitutes the inner circumferential surface of the crown portion.

2. The tire according to claim 1, wherein the belt layer and the resin film are welded together.

3. The tire according to claim 1 , wherein the belt layer is formed by winding a coated cord, which is one or more of the reinforcing cords coated with a resin, spirally in the tire circumferential direction.

4. The tire according to claim 1 , wherein the crown portion includes a resin layer disposed radially outward of the belt layer.

5. The tire according to claim 4 , wherein the resin layer and the tread are bonded together.

6. The tire according to claim 4 , wherein the belt layer and the resin layer are welded together.

7. The tire according to claim 4 , wherein the resin constituting the belt layer and the resin constituting the resin layer are the same type of resin.

8. The tire according to claim 4 , wherein the resin layer is made of only resin.

9. a step of placing a belt having one or more resin-coated reinforcing cords on an outer peripheral surface of a resin film; a step of setting the belt disposed on the resin film and the vulcanized or semi-vulcanized tread in a cavity formed by a tire mold so that a gap is formed between them; a step of injecting molten resin into the cavity to form a tire frame member having bead portions, side portions continuous with the bead portions on the outer sides in the tire radial direction, and a crown portion continuous with the side portions on the inner sides in the tire width direction; A tire manufacturing method comprising:

10. The tire manufacturing method according to claim 9 , wherein the molten resin is injected into the cavity from both outer sides of the tread in the tire width direction.

11. The method for manufacturing a tire according to claim 9, wherein the tread and the belt are set in the cavity so that a portion of the tread contacts the belt and supports each other.

Images