Tire and tire manufacturing method

Abstract

A tire 10 comprises: a resin frame body 20 formed from a thermoplastic resin, the resin frame body 20 having a bead part 12, a side part 14, and a crown part 16, and being such that a recessed part 80 is formed in an inner peripheral surface 50I of a thick-walled part; and an RFID tag 70 accommodated in the recessed part 80.

Description

Tire and tire manufacturing method

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

[0002] Japanese Patent Application Laid-Open No. 2023-087598 discloses a tire having an annular tire frame member made of resin, which includes a bead portion, a side portion connected to the outer side of the bead portion in the tire radial direction, and a crown portion connected to the inner side of the side portion in the tire width direction, and an RFID tag attached to the outer surface of the side portion.

[0003] In the configuration described in JP 2023-087598 A, the RFID tag is attached during the tire manufacturing process, so there is a possibility that the RFID tag may be displaced from the desired position.

[0004] The present disclosure aims to provide a technology relating to a tire in which the positioning accuracy of an RFID tag is improved compared to when the RFID tag is embedded in a location other than the bead portion.

[0005] The tire of the first aspect is formed of a thermoplastic resin and has a bead portion, a side portion, and a crown portion, and is equipped with a resin skeleton having a recessed portion formed on an inner surface in the tire axial direction, and an RFID tag housed in the recessed portion.

[0006] In this tire, a recess is formed in the bead portion on the inner surface of the resin skeleton in the tire axial direction, and an RFID tag is housed in the recess, thereby improving the positioning accuracy of the RFID tag in the tire according to this aspect compared to when the RFID tag is placed in a location other than the recess.

[0007] A tire of a second aspect is the tire according to the first aspect, wherein the recessed portion is formed on an axially inner surface of the bead portion.

[0008] In this tire, the recessed portion is formed on the axially inner surface of the bead portion, so that the tire is less likely to deform due to the load of the vehicle even when in use. As a result, the tire according to this aspect has higher durability than tires in which the recessed portion is formed at a location other than the axially inner surface of the bead portion.

[0009] A third aspect of the tire manufacturing method includes the steps of using a holding mold to hold a bead core at an inner end in the radial direction of an inner mold; arranging a depression-forming core along the inner mold; forming a cavity using an outer mold facing a wall surface of the inner mold with a gap therebetween; injecting a resin material into the cavity to form a resin skeleton having a bead portion, a side portion, a crown portion and a depression portion; and accommodating an RFID tag in the depression portion of the formed resin skeleton.

[0010] In this tire, a recess is formed on the axially inner surface of the resin skeleton, and an RFID tag is housed in the recess. Here, if an RFID tag is placed on the inner surface of the resin skeleton in a tire having an RFID tag, it is difficult to determine the position of the RFID tag during manufacturing. In the tire manufacturing method according to this aspect, a recess is formed on the axially inner surface of the resin skeleton, and the RFID tag is housed in the recess, making it easier to position the RFID tag compared to when no recess is formed.

[0011] A tire manufacturing method of a fourth aspect is the tire manufacturing method according to the third aspect, wherein the depression-forming core is the holding mold.

[0012] In this tire manufacturing method, the holding mold also serves as a depression-forming core that forms depressions in the resin skeleton. According to the tire manufacturing method of this aspect, fewer types of molds are required than when depression-forming cores are prepared separately from the holding mold, thereby reducing manufacturing costs.

[0013] According to the present disclosure, it is possible to provide a technology relating to a tire in which the positioning accuracy of an RFID tag is improved compared to when an RFID tag is embedded in a location other than the bead portion.

[0014] FIG. 1 is a cross-sectional view showing a tire according to the present disclosure. FIG. 2 is a cross-sectional view illustrating a skeletal member according to the present disclosure. FIG. 3 is a plan view illustrating an RFID tag provided in a tire according to the present embodiment. FIG. 4 is a side view illustrating an RFID tag provided in a tire according to the present embodiment. FIG. 5 is a view illustrating a primary molded body according to the present disclosure. FIG. 6 is an enlarged view of portion 3A of FIG. 4, illustrating the structure of a knit layer of a primary molded body according to the present disclosure. FIG. 7 is a view illustrating a manufacturing process for a tire according to the present disclosure, illustrating a state in which a primary molded body is placed in an inner mold. FIG. 8 is a view illustrating a manufacturing process for a tire according to the present disclosure, illustrating a state in which a primary molded body is placed on an inner mold. FIG. 9 is a view illustrating a manufacturing process for a tire according to the present disclosure, illustrating a state in which a resin is injected into a cavity to form a skeletal member. FIG. 10 is a view illustrating a manufacturing process for a tire according to the present disclosure, illustrating a state in which a recessed portion is formed in a skeletal member. FIG. 11 is a cross-sectional view illustrating a skeletal member according to a first modified example of the present disclosure.

[0015] An example of an embodiment of the present disclosure will be described below with reference to the drawings. In each drawing, the same or equivalent components and parts are designated by the same reference numerals. Furthermore, the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0016] Additionally, arrow R shown in each drawing indicates the radial direction of the tire 10, arrow W indicates the width direction (axial direction) of the tire 10, and arrow θ indicates the circumferential direction of the tire 10. In this disclosure, the "outside of the tire" refers to the outside in both the tire radial direction and the tire width direction, and coincides with the directions of arrows R and W in each drawing.

[0017] 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).

[0018] In this disclosure, a thermoplastic resin (including a thermoplastic elastomer) refers to a polymer compound that softens and flows with increasing temperature and becomes relatively hard and strong when cooled. In this specification, a polymer compound that softens and flows with increasing temperature and becomes relatively hard and strong when cooled and has rubber-like elasticity is referred to as a thermoplastic elastomer, and a polymer compound that softens and flows with increasing temperature and becomes relatively hard and strong when cooled and does not have rubber-like elasticity is referred to as a non-elastomer thermoplastic resin.

[0019] 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.

[0020] 1 and 2 show a tire 10 according to the present disclosure. The tire 10 according to the present disclosure includes a tire frame member 17 having a pair of bead portions 12, side portions 14 extending from the bead portions 12 radially outward of the tire 10, and a crown portion 16 (outer peripheral portion) connecting a radially outer end of one side portion 14 to a radially outer end of the tire 10 of the other side portion 14. The tire frame member 17 is provided with a belt layer 32 formed of a resin cord member 26 on the radially outer side of the tire 10, and a tread layer 30 on the radially outer side of the belt layer 32, thereby forming the tire 10.

[0021] In the present disclosure, the radial direction, width direction, and circumferential direction of the tire half body 17A coincide with the radial direction, width direction, and circumferential direction of the tire 10 as shown in FIG. 1 .

[0022] FIG. 2 is a cross-sectional view taken along the width direction of the tire 10, showing an example of the configuration of the tire 10 according to this embodiment.

[0023] 2, the belt layer 32 is formed by wrapping the resin cord member 26 around the outer periphery of the tire frame member 17 in the circumferential direction of the tire 10 and joining it to the tire frame member 17. The belt layer 32 is also formed by joining together adjacent portions of the resin cord member 26 in the width direction of the tire 10. The resin cord member 26 is formed by coating a cord member with a coating resin layer.

[0024] A tread layer 30 made of rubber, which is a material with better abrasion resistance than the resin material that constitutes the tire frame member 17, is arranged on the radially outer peripheral side of the belt layer 32 of the tire 10.

[0025] The resin-coated cord member in the resin cord member 26 is made of a monofilament (single wire) of metal fiber, organic fiber, or the like, or a multifilament (twisted wire) made of twisted fibers of these fibers. Examples of the resin cord member 26 include a monofilament (single wire) made of a single metal cord, and a multifilament (twisted wire) made of twisted multiple metal cords.

[0026] In FIG. 2, the cross-sectional shape of the resin cord member 26 (the shape of the cross section perpendicular to the longitudinal direction of the resin cord member 26) is approximately rectangular, but the resin cord member 26 according to this embodiment is not limited to this and can have various shapes, such as an approximately parallelogram.

[0027] The tread layer 30 is a portion provided on a peripheral surface 52C, which is the outer peripheral surface of the tire 10, and is formed by wrapping a member such as rubber around the belt on the outside in the radial direction of the tire 10.

[0028] 2, the tire frame member 17 includes a pair of tire halves 17A each having a resin frame 20 formed by injection molding of a thermoplastic resin, integrally forming the bead portion 12, the side portion 42, and the half-width crown portion 44. The pair of tire halves 17A are formed by facing each other and joining them at the tire equatorial plane, as shown in FIG.

[0029] 2, the tire half body 17A has the bead portion 12, the knitted fabric layer 41, and the resin skeleton 20 in which the knitted fabric layer 41 is disposed and integrated with the bead core 18 to the crown portion 44 on the radially outer side of the tire 10. Also, as shown in FIG. 2, the tire 10 according to the present embodiment houses an RFID (Radio Frequency Identification) tag 70. The resin skeleton 20 is formed of a thermoplastic resin. In the resin skeleton 20 according to the present embodiment, the knitted fabric layer 41 and the bead core 18 are integrated as a primary molded body 34, which will be described later, and then integrated with the resin skeleton 20.

[0030] In this embodiment, the ranges of the bead portion 12, the side portion 14, and the crown portion 16 are determined based on the dimensions of the tire 10 when it is in use. More specifically, the bead portion 12 is a range H1 in which the thickness gradually decreases radially outward relative to a range H from the radially inner end to the radially outer end excluding the tread layer 30 and the belt layer 32. The side portion 14 is a range H2 in which the thickness is approximately the same relative to the range H excluding the range H1.

[0031] 2, an annular bead core 18 made of a resin-coated steel cord and having, for example, a substantially rectangular cross section is embedded in the bead portion 12. More specifically, as shown in FIG. 2, the bead portion 12 has a thick portion 50 that is thicker than the side portion 14 and in which the bead core 18 is embedded, and an inclined portion 48 that connects the thick portion 50 to the side portion 14.

[0032] The thick portion 50 is a portion that abuts against a rim flange (not shown) and functions to prevent the bead portion 12 from coming off the rim flange. The thick portion 50 has a thick portion outer peripheral surface 50E that abuts against a flange portion of the rim flange (not shown) in the width direction, a thick portion bottom surface 50B that contacts the rim flange (not shown) from the radially outer side, and a thick portion inner peripheral surface 50I that is the surface on the inner side in the width direction relative to the thick portion bottom surface 50B. The thick portion bottom surface 50B is aligned along the axis of the tire 10 (width direction), or is inclined from a heel portion 50H, which is the boundary with the thick portion outer peripheral surface 50E, toward the inner side in the width direction of the tire 10 so as to approach the central axis of the tire 10. Furthermore, the thick portion outer peripheral surface 50E, for example, is aligned radially outward from the heel portion 50H or is slightly inclined toward the inner side in the tire width direction. As an example, the thick portion inner circumferential surface 50I extends radially outward from the toe portion 50T, which is the boundary with the thick portion inner circumferential surface 50I, or is slightly inclined toward the inside in the tire width direction.

[0033] The inclined portion 48 is a portion that functions to distribute stress in the side portion 14 that deforms due to load when the tire 10 is in use. The outer peripheral surface 48E of the inclined portion 48 connects the thick-portion outer peripheral surface 50E of the thick portion 50 and the outer peripheral surface of the side portion 14 while curving in an arch that is slightly recessed in the width direction of the tire 10. Furthermore, the inner peripheral surface 48I of the inclined portion 48 connects the thick-portion inner peripheral surface 50I of the thick portion 50 and the inner peripheral surface of the side portion 14, so that the thickness of the inclined portion 48 gradually decreases from the thick-portion 50 side (radially inner side) toward the side portion 14 side (radially outer side).

[0034] 3A and 3B, an RFID tag 70 includes a main body chip 72 and an antenna 74. The main body chip 72 includes a processor including a CPU or MPU and a memory capable of storing various types of information. The antenna 74 extends from one side and the other side of the main body chip 72.

[0035] The main chip 72 and the antenna 74 are embedded in a resin coating 76 made of a resin material. The resin material forming the resin coating 76 is preferably the same type of material as the resin material forming the resin skeleton 20. The main chip 72 may be embedded in the resin coating 76 by sandwiching it between a film, or the thickness of the main chip 72 may be absorbed by a thick resin coating 76. As shown in FIG. 3B , the RFID tag 70 is flexible in the thickness direction. The RFID tag 70 is also arranged so that the longitudinal direction of the antenna 74 extends along the tire circumferential direction.

[0036] More specifically, the RFID tag 70 is housed in one of a plurality of recesses 80 formed along the bead core 18 in the tire circumferential direction.

[0037] 2 , the tire half 17A has a rubber layer 24 formed on the outer side in the width direction of the tire 10, from the bead portion 12 to the crown portion 44. More specifically, the rubber layer 24 is formed from the crown portion 44 to the outer peripheral surfaces of the side portions 14, the outer peripheral surfaces 48E of the inclined portions 48 in the bead portions 12, the thick-portion outer peripheral surface 50E, the thick-portion bottom surface 50B, and the thick-portion inner peripheral surface 50I. The rubber layer 24 is formed to cover the recessed portions 80. In other words, the recessed portions 80 are covered by the rubber layer 24 that covers the side portions 14 of the tire 10. When the tire 10 is mounted on a wheel, this rubber layer 24 protects the tire half 17A from sunlight and the like, improving weather resistance.

[0038] (Primary molded body 34) Fig. 4 is a diagram showing the primary molded body 34 of the tire half body 17A according to the present disclosure. As shown in Fig. 4, the primary molded body 34 has a knitted body 36, a knitted layer 41 having a reinforcing body 40, and a bead core 18.

[0039] 4 and 5 , the knitted fabric body 36 is formed from a thread-like first fiber material 38, has a folded mesh that is continuously formed in the circumferential direction and radial direction of the tire 10, has ends on both radial sides of the tire 10, and is endless in the circumferential direction of the tire 10. In other words, the knitted fabric body 36 is a member formed by knitting the first fiber material 38 into a ring shape, and has stretchability in the radial direction and circumferential direction (the up-down direction and the left-right direction in FIG. 5 ).

[0040] As will be described later, the first fiber material 38 is made of a material that is compatible with the resin skeleton 20 and the resin coating of the bead cores 18. Specifically, the first fiber material 38 is made of a material such as a polyester-based thermoplastic elastomer, and the same type of resin as the resin skeleton 20 is preferably used. In the present disclosure, compatibility refers to the property of different materials being easily mixed with each other in a molten state.

[0041] As shown in FIGS. 4 and 5 , the reinforcing members 40 are formed from a reinforcing fiber material, extend in the tire radial direction, and are evenly distributed in the tire circumferential direction by being knitted into the knitted fabric main body 36 in the circumferential direction of the tire 10. These thread-like members restrict the elongation of the knitted fabric main body 36 in the radial direction of the tire 10. As described below, the reinforcing fiber material is formed from a material that is incompatible with the resin skeleton 20. Specifically, a material having a higher softening temperature and higher tensile strength than the first fiber material 38, such as aramid fiber or steel cord, is used. The reinforcing fiber material is not limited to a single material, and may be an artificial resin such as aramid fiber, or a fiber body in which steel cord or the like is coated with a resin of the same type as the first fiber material 38. The shape and number of the reinforcing members 40 are determined appropriately depending on the specifications of the tire 10 to be manufactured. The above-mentioned even distribution means that the multiple reinforcing members 40 are spaced approximately equally apart from one another macroscopically. The reinforcing members 40 are preferably arranged at a density of about 10 pieces / mm to 60 pieces / mm in the tire circumferential direction.

[0042] As described above, the knitted body 36 is formed by stockinette knitting, as an example, although any knitting method may be used as long as the knitted body 36 has stretchability in the radial and circumferential directions of the tire 10. In other words, the primary molded body 34 in the present disclosure has a so-called inlay structure in which a reinforcing fiber material is knitted into the knitted body 36.

[0043] The shape of the knitted fabric body 36 is determined appropriately depending on the specifications of the tire 10 to be manufactured, but is shaped so as to be arranged in the resin skeleton 20 from the bead core 18 to the crown portion 44 (see also Figures 6 and 9).

[0044] The resin coating of the bead core 18 and the braid body 36 are made of materials that are compatible with each other, and the braid body 36 and the resin coating of the bead core 18 can be welded to each other. For this reason, the bead core 18 in this embodiment is welded to the inner end of the braid body 36 in the radial direction of the tire 10.

[0045] Next, a tire half body manufacturing method and a tire manufacturing method according to the present disclosure will be described with appropriate reference to Figures 4 to 9. The tire half body manufacturing method according to the present disclosure includes a primary molding step, a fixing step, a mold clamping step, and an injection step.

[0046] (Primary Molding Step) In the primary molding step, the annular bead core 18 is integrated with the inner end of the knitted fabric layer 41 in the radial direction of the tire 10 to form a primary molded body.

[0047] (Fixing Process) Figure 6 is a diagram illustrating the state in which the primary formed body is placed in the radially expanding inner mold 52. In the fixing process, the radially outer end of the primary formed body is hooked onto the radially outer circumferential surface 52C of the inner mold 52. More specifically, as shown in Figure 6, the primary molded body 34 is placed over the inner mold 52, which is formed into a cylindrical shape by circumferentially arranging multiple parts, so as to cover it from one axial side (the right side in Figure 6, the bottom side in Figure 7) to the other axial side (the left side in Figure 6, the top side in Figure 7). In addition, a bead core 18 is positioned on one axial side of the inner mold 52. As shown in Figure 6, the primary formed body is not fixed on the other axial side, and the primary molded body 34 is placed over the inner mold 52 as the knitted fabric body 36 shrinks in the axial and radial directions of the inner mold 52, and remains aligned with the wall surfaces of the inner mold 52 (the radial outer sides of the peripheral surface 52C and side surface 52S).

[0048] Note that a plurality of slide dies 54 that can move further toward one axial side from a side surface 52S on one axial side of the inner mold 52 are provided at intervals in the tire circumferential direction on one axial side (inner side) of the inner mold 52. As shown in Fig. 7 , the slide dies 54 extend in the circumferential direction and are recessed toward one axial side, and the bead cores 18 are disposed in the recesses of the slide dies 54. Note that, as shown in Fig. 8 , at locations of the inner mold 52 in the tire circumferential direction where no slide dies 54 are disposed, the bead cores 18 are disposed with a gap between them and the inner mold 52.

[0049] Although not shown in Figure 6, an outer mold 56 is arranged opposite the inner mold 52 on one axial side of the inner mold 52, covering the radial direction and one axial side of the inner mold 52 and forming a gap.

[0050] (Mold Clamping Process) Subsequently, in the mold clamping process, a cavity C is formed using the circumferential surface 52C of the inner mold 52 and an outer mold 56 that faces the side surface 52S of the inner mold 52 with a gap therebetween. More specifically, from the state shown in FIG. 6 , the outer mold 56, which covers the radial direction and one axial side of the inner mold 52, is brought closer from one axial side of the inner mold 52 to form a cavity C, which is a gap, between the side surface 52S and circumferential surface 52C of the inner mold 52 and the inner surface 56I of the outer mold 56. Furthermore, with the cavity C formed, the slide mold 54 is moved to one axial side, thereby pressing the bead core 18 against the inner surface 56I of the outer mold 56, as shown in FIG. 7 . This cavity C has a shape equivalent to that of the tire half body 17A according to the present disclosure, and the tire half body 17A is formed by pouring molten thermoplastic resin into the cavity C, as described below.

[0051] That is, in the present disclosure, the radial direction, width direction, and circumferential direction of the inner mold 52 coincide with the radial direction, width direction, and circumferential direction of the tire 10 as shown in FIG. 1 .

[0052] In the state shown in FIG. 7, a gate portion 58 for injecting a thermoplastic resin (described later) is formed on one axial side of the inner mold 52 radially inward of the bead core 18.

[0053] Furthermore, as shown in Figure 7, when the knitted fabric body 36 of the primary molded body 34 is hung on the inner mold 52, it is stretched in the axial and radial directions of the inner mold 52, and therefore a contracting force acts on it, and inside the cavity C, it is in contact with the inner mold 52 from the side surface 52S to the peripheral surface 52C.

[0054] (Injection process) Next, from the state shown in Fig. 7 , molten thermoplastic resin is injected into the cavity C through the gate portion 58. In this case, since the gate portion 58 is provided radially inward of the inner mold 52 relative to the bead cores 18, the knitted fabric body 36 is pressed against the inner surface 56I of the outer mold 56 in the cavity C by the molten thermoplastic resin injected through the gate portion 58, as shown in Fig. 9 . Then, with the knitted fabric body 36 pressed against the inner surface 56I of the outer mold 56, the thermoplastic resin cools, thereby forming the tire half body 17A in the cavity C.

[0055] In the tire half body 17A according to the present disclosure, as shown in FIG. 9 , the knitted fabric body 36 is cooled in a state where it is pressed against an inner surface 56I of an outer mold 56 in the cavity C. Therefore, the knitted fabric body 36 is integrated with the formed resin skeleton 20 while being positioned on the outer side of the tire. More specifically, in the side portion 42 of the resin skeleton 20 (one axial side of the resin skeleton 20), the knitted fabric body 36 is preferably integrated with the resin skeleton 20 while being positioned on one axial side of a position 0.5 times the thickness of the side portion 42 of the resin skeleton 20. Furthermore, in the crown portion 16 of the tire 10 (radially outer side of the resin skeleton 20), the knitted fabric body 36 is preferably integrated with the resin skeleton 20 while being positioned radially outward of a position 0.5 times the thickness of the crown portion 16 of the resin skeleton 20.

[0056] 9 , the knitted fabric body 36 is pressed against the inner surface 56I of the outer mold 56 in the cavity C, whereby the knitted fabric body 36 is integrated in a state in which it expands radially outward and circumferentially outward of the tire 10. In other words, the reinforcing body 40 woven into the knitted fabric body 36 is integrated with the resin skeleton 20 in a state in which it expands in the circumferential direction of the tire 10 of the tire half body 17A.

[0057] Through the above steps, the tire half body 17A according to the present disclosure is manufactured.

[0058] Next, a tire manufacturing method will be described. The tire manufacturing method according to the present disclosure includes an RFID tag arrangement step, a rubber layer arrangement step, a joining step, a belt layer arrangement step, and a tread layer arrangement step.

[0059] (RFID Tag Placement Process) In the RFID tag placement process, an RFID tag 70 is further placed on the pair of tire halves 17A manufactured by the process described above. More specifically, as shown in FIG. 10 , recesses 80 are formed extending in the circumferential direction on the thick-portion inner circumferential surface 50I formed by the injection process described above. Furthermore, as shown in FIG. 10 , each recess 80 is formed across the bead core 18 in the tire radial direction. Because the slide mold 54 that holds the bead core 18 functions as a so-called core in the injection process, these recesses 80 are formed side by side with the bead core 18 in the tire axial direction. In other words, the slide mold 54 according to this embodiment is an example of a "holding mold" and an example of a "recess-forming core." Although not shown in FIG. 10 , multiple recesses 80 are formed in the circumferential direction. Furthermore, the thick-portion inner circumferential surface 50I in this embodiment is an example of an "axially inner surface" in this embodiment.

[0060] In this embodiment, the RFID tag 70 is placed in one of the recesses 80 formed as shown in Fig. 10. More specifically, the RFID tag 70 is positioned by fitting it into one of the recesses 80, and then the RFID tag 70 is welded to the tire half 17A inside the recess 80 using a heating device (not shown).

[0061] (Rubber Layer Arrangement Step) In the rubber layer arrangement step, the rubber layer 24 is arranged on one widthwise side of the pair of tire halves 17A manufactured by the steps described above. As a result, the RFID tag 70 and the recessed portion 80 are covered with the rubber layer 24 as shown in FIG.

[0062] In the joining process, the pair of tire halves 17A on which the rubber layers 24 have been arranged in the process described above are joined at their widthwise inner end portions corresponding to the tire equatorial plane (opposite the direction in which the side portions 42 are formed). As an example of a joining method, the other surfaces of the tire halves 17A are welded together via a resin material to form the tire frame member 17 as shown in FIG.

[0063] (Belt Layer Arrangement Process) In the belt layer arrangement process, a circular belt layer 32 is arranged on the tire frame member 17 manufactured in the joining process on the radially outer side of the tire 10. The belt layer 32 can be formed by winding the resin cord member 26 around the crown portion 44 of the tire frame member 17.

[0064] (Tread Layer Arranging Step) In the tread layer arranging step, an annular tread layer is arranged on the tire frame member 17 manufactured in the belt layer arranging step, on the radially outer side of the tire 10 .

[0065] As an example, the radially outer end of the knitted fabric layer 41 extends to the crown portion 16 of the tire frame member 17 and overlaps with the belt layer 32. The overlapping amount with the belt layer 32 is preferably 5 mm or more from the end of the belt layer 32 in the width direction of the tire 10 toward the center in the width direction of the tire 10. Alternatively, the knitted fabric layer 41 may extend to the center in the width direction of the tire 10.

[0066] The tire 10 of this embodiment is obtained through the above steps. Then, as shown in Fig. 2 etc., the tire 10 of this embodiment is disposed between the resin skeleton 20 and the rubber layer 24 in the bead portion 12.

[0067] Next, the actions and effects obtained by the tire 10 and the tire manufacturing method according to the present disclosure will be described.

[0068] (Actions and Effects) In the tire 10 according to the present embodiment, a recess 80 is formed in the inner circumferential surface 50I of the thick portion of the resin skeleton 20, and an RFID tag 70 is housed in the recess 80. Here, if the RFID tag 70 is disposed on a smooth surface on the inside in the tire axial direction of the resin skeleton 20, the RFID tag 70 is likely to come off from its attachment position when the tire 10 is in use (when a vehicle equipped with the tire 10 is running).

[0069] On the other hand, in the tire 10 according to this aspect, a recessed portion 80 is formed in the thick-wall portion inner circumferential surface 50I, and the RFID tag 70 is accommodated in the recessed portion 80, so that the RFID tag 70 is less likely to come off from its attachment position during the manufacturing process compared to when the RFID tag 70 is placed in a location other than the recessed portion 80. As a result, in the tire 10 according to this aspect, the positioning accuracy of the RFID tag 70 is improved compared to when the RFID tag 70 is placed in a location other than the recessed portion 80.

[0070] Furthermore, in the tire 10 according to this embodiment, the recessed portions 80 are formed on the thick-walled inner circumferential surface 50I of the bead portion 12, and therefore deformation due to the load of the vehicle is unlikely to occur even when the tire 10 is in use. As a result, the tire 10 according to this aspect has higher durability than when the recessed portions 80 are formed in locations other than the bead portion 12.

[0071] Furthermore, in the tire 10 according to this embodiment, a recess 80 is formed in the thick-portion inner circumferential surface 50I of the resin skeleton 20, and an RFID tag 70 is housed in the recess 80. Here, if the RFID tag 70 is to be placed on the inner surface of the resin skeleton 20 in a tire 10 having an RFID tag 70, it is difficult to determine the position of the RFID tag 70 during manufacturing. In the tire manufacturing method according to this aspect, the recess 80 is formed in the thick-portion inner circumferential surface 50I of the resin skeleton 20, and the RFID tag 70 is housed in the recess 80, making it easier to position the RFID tag 70 compared to a case in which the recess 80 is not formed.

[0072] Furthermore, in the tire manufacturing method according to this embodiment, the slide mold 54 also serves as a depression-forming core that forms the depression portion 80 in the resin skeleton 20. According to the tire manufacturing method according to this aspect, fewer types of molds are required compared to when the depression-forming core is prepared separately from the slide mold 54, thereby reducing manufacturing costs.

[0073] (First Modification) In the above description, in the tire manufacturing method, the holding mold also serves as the depression-forming core, but the tire manufacturing method according to the present embodiment is not limited to this. For example, in the injection step, a depression-forming core may be provided separately from the slide mold 54, so that the depression portion 80 is formed on the axially inner surface of the resin skeleton 20.

[0074] 11 , the recessed portion 180 may be formed in the bead portion 12 radially outward of the bead core 18. In this modification, the recessed portion 180 is preferably formed in the inner half of the range of the bead portion 12 radially in the tire. This is because if the recessed portion 180 is formed in the inner half of the range of the bead portion 12 radially in the tire, deformation is unlikely to occur even when the vehicle to which the tire 10 is attached is running, and the RFID tag 70 is unlikely to come off.

[0075] In this case as well, a tire 10 can be obtained that provides the same effects as those of the above-described embodiment.

[0076] (Other Modified Examples) In the above description, the recessed portions 80 are described as being formed in the bead portions 12, but the tire 10 according to the present embodiment is not limited to this. For example, the recessed portions 80 may be formed in the side portions 14 as long as the durability of the tire 10 is not significantly impaired due to, for example, the concentration of stress on the resin skeleton 20 caused by the formation of the recessed portions 80.

[0077] Furthermore, in the above description, the RFID tag 70 is attached to the resin skeleton 20 by being welded to the recessed portion 80, but the tire 10 according to the present embodiment is not limited to this. For example, the RFID tag 70 may be adhered to the recessed portion 80 by using an adhesive. In this case as well, a tire 10 that exhibits the same effects as those of the above embodiment can be obtained.

[0078] The above describes an embodiment of the present disclosure with reference to the accompanying drawings. However, it is clear that a person with ordinary knowledge in the field of technology to which the present disclosure pertains can conceive of various modifications or applications within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0079] The disclosure of Japanese Patent Application No. 2023-209518, filed on December 12, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A tire comprising: a resin skeleton formed of a thermoplastic resin, having a bead portion, a side portion, and a crown portion, and having a recessed portion formed on an axially inner surface of the resin skeleton; and an RFID tag housed in the recessed portion.

2. The tire according to claim 1, wherein the recessed portion is formed on an axially inner surface of the bead portion.

3. A tire manufacturing method comprising the steps of: using a retaining mold to hold a bead core at the radially inner end of an inner mold; arranging a recess-forming core along the inner mold; forming a cavity using an outer mold facing the wall surface of the inner mold with a gap; injecting a resin material into the cavity to form a resin skeleton having a bead portion, a side portion, a crown portion and a recess portion; and accommodating an RFID tag in the recess of the formed resin skeleton.

4. A tire manufacturing method according to claim 3, wherein the depression forming core is the retaining mold.

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