Tire, and method for producing tire

Abstract

A tire 10 comprises: a knitted fabric layer 41 having a knitted fabric body 36 that is formed of a first fibrous material 38, has a mesh having a folded-over shape and being continuous in the tire circumferential direction and the tire radial direction, and is endless in the circumferential direction, and a reinforcement body 40 that is formed of a reinforcing fibrous material, and is knitted into the knitted fabric body 36 in an evenly spaced manner in the tire circumferential direction to limit extension of the knitted fabric body 36 in the tire radial direction; a resin skeleton body 20 which is formed of a thermoplastic resin, and in which the knitted fabric layer 41 is integrated and arranged from a bead section 12 having a bead core 18 embedded therein to a crown section 16; and an RFID tag 70 that is embedded in the resin skeleton body 20 inward or outward of the knitted fabric layer 41 in the tire axial direction.

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 the RFID tag is prone to shifting from the desired position.

[0004] The present disclosure aims to provide a technology relating to tires with improved positioning accuracy of RFID tags.

[0005] The tire of the first aspect includes a knitted layer having a knitted body formed from a first fiber material, having a folded-over mesh that is continuous in the tire circumferential direction and the tire radial direction and is endless in the circumferential direction, and reinforcing bodies formed from a reinforcing fiber material and woven into the knitted body at equal intervals in the tire circumferential direction and that regulate the elongation of the knitted body in the tire radial direction; a resin skeleton formed from a thermoplastic resin and in which the knitted layer is integrated and arranged from a bead portion in which a bead core is embedded to a crown portion; and an RFID tag embedded in the resin skeleton on the inner side or the outer side in the tire axial direction of the knitted layer.

[0006] In this tire, the RFID tag is disposed on the inner side or the outer side of the knitted fabric layer in the tire width direction. As a result, in the tire according to this aspect, when the RFID tag is disposed on the outer side of the knitted fabric layer in the tire axial direction, the positioning accuracy of the RFID tag is improved. Furthermore, in the tire according to this aspect, when the RFID tag is disposed on the inner side of the knitted fabric layer in the tire axial direction, the durability of the RFID tag can be improved compared to when the RFID tag is disposed on the outer side of the knitted fabric layer in the tire axial direction.

[0007] A tire of a second aspect is the tire according to the first aspect, wherein the RFID tag is embedded in the resin skeleton in a state where it is joined to the knitted fabric layer.

[0008] In this tire, the RFID tag is embedded in the resin skeleton while being bonded to the knitted layer, which makes it more difficult for the knitted layer and the RFID tag to become misaligned. As a result, the tire according to this aspect has higher positioning accuracy for the RFID tag than when the RFID tag is embedded in the resin skeleton without being bonded to the knitted layer.

[0009] A tire of a third aspect is the tire according to the first or second aspect, wherein the RFID tag is embedded in the bead portion of the resin skeleton.

[0010] In this tire, the RFID tag is embedded in the bead portion of the resin skeleton, so that the tire is less likely to deform due to the load of the vehicle even when in use. As a result, in the tire according to this aspect, the durability of the RFID tag is higher than when the RFID tag is embedded in a location other than the bead portion.

[0011] A fourth aspect of the tire manufacturing method includes the steps of: forming a primary formed body by integrating an annular bead core with an inner end portion in the tire radial direction of a knit layer having: a knitted body formed from a first fiber material and having folded-back meshes formed continuously in the tire circumferential direction and the tire radial direction, the knitted body having ends on both sides in the tire radial direction and being endless in the tire circumferential direction; and reinforcing bodies formed from a reinforcing fiber material and knitted into the knitted body at equal intervals in the tire circumferential direction while restricting elongation of the knitted body in the tire radial direction; holding the bead core of the primary formed body at the inner end portion in the radial direction of an inner mold, and placing an RFID tag between the knitted layer and the inner mold; forming a cavity using an outer mold facing a wall surface of the inner mold with a gap between them; and injecting a resin material into the cavity from a position inside the bead core in the tire axial direction of the inner mold, and forming a resin skeleton body while pressing the primary formed body against the outer mold.

[0012] In this tire manufacturing method, by disposing the RFID tag between the knitted fabric layer and the inner mold, the RFID tag gets caught on the knitted fabric layer when resin is injected into the cavity, making it less likely to move to an unexpected location. Therefore, the tire manufacturing method according to this aspect can improve the positioning accuracy of the RFID tag in the manufacturing process of a tire having an RFID tag in a resin skeleton.

[0013] A tire manufacturing method of a fifth aspect is the tire manufacturing method according to the fourth aspect, wherein in the step of forming the resin skeleton, a resin material is injected from an inner end of the cavity in the tire axial direction.

[0014] In this tire manufacturing method, the resin material is injected from the inner end of the cavity in the tire axial direction, which reduces the pressure of the resin material flowing into the portion adjacent to the bead core. As a result, the tire manufacturing method according to this aspect can improve the positioning accuracy of the RFID tag compared to when the resin material is injected from a location other than the inner end of the cavity in the tire axial direction.

[0015] A sixth aspect of the tire manufacturing method includes the steps of forming a primary formed body by integrating an annular bead core with an inner end portion in the tire radial direction of a knit layer, the knit layer including: a knitted body formed of a first fiber material, having folded-back meshes formed continuously in the tire circumferential direction and the tire radial direction, with ends on both sides in the tire radial direction and being endless in the tire circumferential direction; and reinforcing bodies formed of a reinforcing fiber material and knitted into the knitted body at equal intervals in the tire circumferential direction while restricting elongation of the knitted body in the tire radial direction. The method includes the steps of: arranging the knitted layer along the wall surface of the inner mold while holding the bead core of the primary formed body at the radially inner end of the inner mold; arranging an RFID tag on the side of the knitted layer opposite the inner mold; forming a cavity using an outer mold that faces the wall surface of the inner mold with a gap between them; and injecting a resin material into the cavity from a position inside the inner mold in the tire axial direction, further inside than the bead core, and forming a resin skeleton while pressing the primary formed body against the outer mold.

[0016] In this tire manufacturing method, the primary molded body is placed along the wall surface of the inner mold, and then the RFID tag is placed on the opposite side of the knitted fabric layer from the inner mold, so that the RFID tag can be pressed down by the knitted fabric layer when the resin material is injected. Therefore, the tire manufacturing method according to this aspect can improve the positioning accuracy of the RFID tag in the manufacturing process of a tire having an RFID tag in a resin skeleton.

[0017] A seventh aspect of the tire manufacturing method is the tire manufacturing method according to the sixth aspect, wherein in the step of forming the resin skeleton, a resin material is injected from an inner end of the cavity in the radial direction.

[0018] In this tire manufacturing method, the resin material is injected from the radially inner end of the cavity, so the RFID tag is pressed against the wall surface of the cavity while being covered by the knitted fabric layer of the primary molded body. As a result, the tire manufacturing method according to this aspect can improve the positioning accuracy of the RFID tag compared to when the resin material is injected from a location other than the radially inner end of the cavity.

[0019] A tire manufacturing method of an eighth aspect is a tire manufacturing method according to any one of the fourth to seventh aspects, wherein in the step of placing the RFID tag, the RFID tag is placed in a portion of the knitted fabric layer adjacent to the bead core.

[0020] In this tire manufacturing method, the RFID tag is embedded in the bead portion of the resin skeleton to be disposed in the cavity adjacent to the bead core. Here, in a tire having a resin skeleton, the bead portion is less likely to deform during use than other portions. Therefore, according to the tire manufacturing method of this aspect, the durability of the RFID tag in the tire is increased compared to when the RFID tag is disposed in a portion other than the portion adjacent to the bead core.

[0021] According to the present disclosure, a technology relating to a tire with improved positioning accuracy of an RFID tag can be provided.

[0022] 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 of a first embodiment; FIG. 3 is a plan view illustrating an RFID tag provided in the tire according to the present embodiment; FIG. 4 is a side view illustrating an RFID tag provided in the tire according to the present embodiment; FIG. 5 is a view illustrating a primary molded body according to the first embodiment of the present disclosure; FIG. 6 is an enlarged view of portion 3A of FIG. 4, illustrating the structure of a knit layer of the primary molded body according to the first embodiment of the present disclosure; FIG. 7 is a view illustrating a manufacturing process of a tire according to the first embodiment of the present disclosure, illustrating a state in which the primary molded body is placed in an inner mold; FIG. 8 is a view illustrating a manufacturing process of a tire according to the first embodiment of the present disclosure, illustrating a state in which the primary molded body is placed on the inner mold; FIG. 9 is a view illustrating a manufacturing process of a tire according to the first embodiment of the present disclosure, illustrating a state in which a resin is injected into a cavity to form a skeletal member; FIG. 10 is a cross-sectional view illustrating a skeletal member of a second embodiment; FIG. 11 is a view illustrating a primary molded body according to a second embodiment of the present disclosure; FIG. 12 is a view illustrating a manufacturing process of a tire according to a second embodiment of the present disclosure, illustrating a state in which the primary molded body is placed on the inner mold; FIG. 13 is a view illustrating a manufacturing process of a tire according to the second embodiment of the present disclosure, illustrating a state in which the primary molded body is placed on the inner mold; FIG. 10 is a diagram illustrating a manufacturing process of a tire according to a second embodiment of the present disclosure, illustrating how a resin is injected into a cavity to form a frame member.

[0023] 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.

[0024] 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.

[0025] 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).

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 .

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 2 , the tire half body 17A has the bead portion 12, the knitted fabric layer 41, and a resin skeleton 20 in which the knitted fabric layer 41 is disposed radially outward of the tire 10 and integrated with the bead core 18 to the crown portion 44. The tire 10 according to the present embodiment also has 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 (described later) and then integrated with the resin skeleton 20.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 2, the RFID tag 70 is embedded in the bead portion 12 of the resin skeleton 20, more inward in the tire width direction than the knitted fabric layer 41. More specifically, the RFID tag 70 is embedded in the bead portion 12 of the resin skeleton 20, in the inclined portion 48 along the knitted fabric layer 41 (described later).

[0045] 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 surface of the side portion 14, the outer peripheral surface 48E of the inclined portion 48 in the bead portion 12, the thick-portion outer peripheral surface 50E, the thick-portion bottom surface 50B, and the thick-portion inner peripheral surface 50I. 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.

[0046] (Primary molded body 34) Fig. 4 is a diagram showing the primary molded body 34 of the tire half body 17A according to this embodiment. 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 the bead core 18.

[0047] 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 ).

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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).

[0052] 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.

[0053] 2, in this embodiment, the knitted fabric layer 41 is embedded in the resin skeleton 20 along the outer contour of the resin skeleton 20 in the axial direction. In other words, the knitted fabric layer 41 is disposed biased toward the outer side of the resin skeleton 20 in the axial direction.

[0054] 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.

[0055] (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.

[0056] 4, an RFID tag 70 is attached to the primary molded body so as to be adjacent to the bead core 18 on the radially outer side of the bead core 18. The RFID tag 70 may be attached to the primary molded body by any method, but as an example, the knitted fabric layer 41 and the resin coating portion 76 are bonded together with an adhesive.

[0057] (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).

[0058] 7, the RFID tag 70 is located axially inward of the knitted fabric body 36. In other words, the RFID tag 70 is disposed in the adjacent portion 46 of the bead core 18 within the cavity C. The adjacent portion 46 of the bead core 18 corresponds to the location where the inclined portion 48 of the bead portion 12 is formed in the tire 10 manufactured by the tire manufacturing method of this embodiment.

[0059] 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 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.

[0060] 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.

[0061] (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.

[0062] 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 .

[0063] In the state shown in FIG. 7, a gate portion 60 for injecting a thermoplastic resin (described later) is formed on one axial side of the inner mold 52 radially outward from the bead core 18.

[0064] 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.

[0065] (Injection Process) Next, from the state shown in Fig. 7 , molten thermoplastic resin is injected into the cavity C through the gate portion 60. The thermoplastic resin injected through the gate portion 60 presses the knitted body 36 against the inner surface 56I of the outer mold 56 in the cavity C, as shown in Fig. 9 . Then, with the knitted 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. Note that, as the molten thermoplastic resin is injected through the gate portion 60, air in the cavity C is discharged through the air vent 58.

[0066] 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.

[0067] 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. That is, the reinforcing body 40 woven into the knitted fabric body 36 is integrated with the resin skeleton 20 of the tire half body 17A in a state in which it expands in the circumferential direction of the tire 10. As a result, in the present embodiment, the RFID tag 70 is embedded in the bead portion 12 of the tire half body 17A, inside the knitted fabric layer 41 and adjacent to the bead core 18.

[0068] 9, the thermoplastic resin injected from the gate 60 flows through the radially outer side of the cavity C to the bead core 18 side. Therefore, in the injection process according to this embodiment, the thermoplastic resin flows to the vicinity of the bead core 18 with a lower momentum (flow rate, pressure, etc.) than near the gate 60.

[0069] As a result, in this embodiment, the RFID tag 70 is embedded inside the knit layer 41 near the bead core 18 in the tire half body 17A. More specifically, the RFID tag 70 is embedded in the inclined portion 48 in the knit layer 41 of the tire half body 17A.

[0070] Through the above steps, the tire half body 17A according to this embodiment is manufactured.

[0071] Next, a tire manufacturing method will be described. The tire manufacturing method according to the present disclosure includes a rubber layer disposing step, a joining step, a belt layer disposing step, and a tread layer disposing step.

[0072] (Rubber Layer Arranging Step) In the rubber layer arranging step, the rubber layer 24 is arranged on one widthwise side of the pair of tire half bodies 17A manufactured by the steps described above.

[0073] 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.

[0074] (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.

[0075] (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 .

[0076] 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.

[0077] The tire 10 of this embodiment is obtained through the above steps. Then, as shown in Fig. 2 and other figures, the RFID tag 70 in the resin skeleton 20 is embedded in the bead portion 12 of the tire 10.

[0078] Next, the actions and effects obtained by the tire 10 and the tire manufacturing method according to the present disclosure will be described.

[0079] (Actions and Effects) In the tire 10 according to this embodiment, the RFID tag 70 is disposed on the inner side in the tire width direction than the knitted fabric layer 41. Here, in the tire 10 having the knitted fabric layer 41, when an impact is applied to the side portion 14 from the outer side in the tire axial direction during use, the knitted fabric layer 41 easily absorbs the impact. Therefore, the tire 10 according to this aspect can improve the durability of the RFID tag 70 compared to when the RFID tag 70 is disposed on the outer side in the tire axial direction than the knitted fabric layer 41.

[0080] Furthermore, in the tire 10 according to the present embodiment, the RFID tag 70 is embedded in the resin skeleton 20 while being bonded to the knitted layer 41, which makes it more difficult for the knitted layer 41 and the RFID tag 70 to become misaligned. As a result, the tire 10 according to this aspect has improved positioning accuracy of the RFID tag 70 compared to a case in which the RFID tag 70 is embedded in the resin skeleton 20 without being bonded to the knitted layer 41.

[0081] Furthermore, in the tire 10 according to this embodiment, the RFID tag 70 is embedded in the bead portion 12 of the resin skeleton 20, 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 durability of the RFID tag 70 in the tire 10 according to this aspect is higher than when the RFID tag 70 is embedded in a location other than the bead portion 12.

[0082] Furthermore, in the tire manufacturing method according to this embodiment, by disposing the RFID tag 70 between the knitted fabric layer 41 and the inner mold 52, the RFID tag 70 gets caught on the knitted fabric layer 41 and is less likely to move to an unexpected location when resin is injected into the cavity C. Therefore, according to the tire manufacturing method according to this aspect, it is possible to improve the positioning accuracy of the RFID tag 70 in the manufacturing process of the tire 10 having the RFID tag 70 in the resin skeleton 20.

[0083] Furthermore, in the tire manufacturing method according to this embodiment, the resin material is injected from the inner end of the cavity C in the axial direction of the tire 10, thereby reducing the pressure of the resin material flowing into the adjacent portion 46 of the bead core 18. As a result, according to the tire manufacturing method according to this aspect, the positioning accuracy of the RFID tag 70 can be improved compared to when the resin material is injected from a location other than the inner end of the cavity C in the axial direction of the tire 10.

[0084] Furthermore, in the tire manufacturing method according to this embodiment, the RFID tag is disposed in the cavity C in the adjacent portion 46 of the bead core 18, and therefore the RFID tag 70 is embedded in the bead portion 12 of the resin skeleton 20. Here, in a tire having the resin skeleton 20, the bead portion 12 is less likely to deform during use than other portions. Therefore, according to the tire manufacturing method according to this aspect, the durability of the RFID tag 70 in the tire 10 is increased compared to when the RFID tag 70 is disposed in a portion other than the adjacent portion 46 of the bead core 18.

[0085] (Modification) In the above description, the RFID tag 70 is disposed in the inclined portion 48 of the bead portion 12, but the tire 10 according to the present embodiment is not limited to this. For example, the RFID tag 70 may be disposed in the thick portion 50 as long as it is disposed axially inward of the knitted layer 41. Since the thick portion 50 is less likely to deform during use than the inclined portion 48, in this case, the durability of the RFID tag 70 can be further increased.

[0086] The RFID tag may be disposed in the side portion 14 as long as it is disposed axially inward of the knitted layer 41. In this case, the RFID tag 70 is located farther from the outer edge of the rim flange (not shown) than when the RFID tag 70 is disposed in the bead portion 12, making it easier to communicate with the RFID tag 70.

[0087] In the above description, the RFID tag 70 is embedded in the resin skeleton 20 in a state where it is welded to the knitted layer 41, 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 knitted layer 41 using an adhesive, or may be fastened using a hook-and-loop fastener or the like. In this case, too, the same functions and effects as those of the tire 10 described above can be obtained.

[0088] In the above description, the RFID tag 70 is embedded in the resin skeleton 20 while being welded to the knitted layer 41, but the tire 10 according to the present embodiment is not limited to this. For example, the RFID tag 70 may simply be placed without being joined to the knitted layer 41, as long as it does not shift from the position shown in Fig. 6 during the injection process. Even in this case, the same actions and effects as those of the tire 10 described above can be obtained.

[0089] Furthermore, in the above description, the RFID tag 70 is disposed in the adjacent portion 46 of the cavity C to the bead core 18, but the location where the RFID tag 70 is disposed is not limited to the adjacent portion 46, as long as it is located inside the knitted layer 41. Even in this case, by disposing the RFID tag 70 inside the knitted layer 41 of the bead portion 12 in the tire axial direction, the positioning accuracy of the RFID tag is improved compared to when the RFID tag 70 is embedded in a location other than the bead portion 12. Even in this case, the same actions and effects as those of the tire 10 described above can be obtained.

[0090] Next, a tire 110 according to a second embodiment of the present disclosure will be described with reference to Fig. 10 to Fig. 14. In the description of the tire 110 according to the second embodiment, the same components as those according to the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

[0091] Second Embodiment (Configuration) FIG. 10 is a cross-sectional view taken along the width direction of a tire 110, showing an example of the configuration of a tire 110 according to this embodiment.

[0092] As shown in FIG. 10 , in the resin skeleton 20 of this embodiment, the knitted fabric layer 41 and the bead cores 18 are integrated into a primary molded body 134 (described later) and then integrated into the resin skeleton 20 .

[0093] 10 , in the present embodiment, the RFID tag 70 is embedded in the bead portion 12 of the resin skeleton 20, outside the knitted fabric layer 41 in the tire width direction. More specifically, the RFID tag 70 is embedded in the bead portion 12 outside the bead core 18 in the tire radial direction and at the interface between the resin skeleton 20 and the rubber layer 24. The RFID tag 70 may be wrapped in the resin skeleton 20.

[0094] (Primary molded body 134) Figure 11 is a diagram showing a primary molded body 134 included in a tire half body 17A according to this embodiment. As shown in Figure 11, the primary molded body 134 includes a knitted fabric layer 41 having a knitted fabric main body 36 and a reinforcing body 40, and a bead core 18. Note that the position at which the RFID tag 70 is disposed in the primary molded body 134 according to this embodiment differs from that in the primary molded body 34 according to the first embodiment. More specifically, in the primary molded body 134 according to this embodiment, the RFID tag 70 is disposed on the opposite surface across the knitted fabric layer 41 from that in the first embodiment (see also Figure 4).

[0095] The other configurations of the tire 110 in this embodiment are the same as those in the first embodiment.

[0096] Next, a tire half body manufacturing method and a tire manufacturing method according to this embodiment will be described with appropriate reference to Figures 11 to 14. The tire half body manufacturing method according to this embodiment includes a primary molding step, a fixing step, a mold clamping step, and an injection step.

[0097] (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 110 to form a primary molded body 134. The procedure for creating the primary molded body 134 is the same as in the first embodiment.

[0098] (Fixing Step) The fixing step is the same as in the first embodiment. However, in this embodiment, the RFID tag 70 is located axially outward of the knitted fabric body 36, as shown in Fig. 12 . In other words, the RFID tag 70 is disposed in the cavity C in the adjacent portion 46 of the bead core 18. The adjacent portion 46 of the bead core 18 corresponds to the location where the bead portion 12 is formed in the tire 110 manufactured by the tire manufacturing method of this embodiment.

[0099] (Clamping Process) The clamping process is the same as that in the first embodiment, as shown in FIG.

[0100] 12, a gate portion 160 for injecting a thermoplastic resin, which will be described later, is formed on one axial side of the inner mold 52 radially inward of the bead core 18. The air vent 158 ​​in this embodiment is formed on the outer side in the tire radial direction.

[0101] (Injection Process) In the injection process of the present embodiment, molten thermoplastic resin is injected into the cavity C through the gate portion 160 from the state shown in Fig. 12 . The thermoplastic resin injected through the gate portion 160 presses the knitted body 36 against the inner surface 56I of the outer mold 56 in the cavity C, as shown in Fig. 14 . Then, with the knitted 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. Note that, as the molten thermoplastic resin is injected through the gate portion 160, air in the cavity C is discharged through the air vent 158.

[0102] 14 , the tire half body 17A according to the present disclosure is cooled in a state in which the knitted fabric body 36 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 110 (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.

[0103] 14 , 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 110. As a result, in the present embodiment, the RFID tag 70 is integrated together with the knitted fabric body 36 in a state in which it is pressed against the outer mold 56. That is, 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 110 of the tire half body 17A. As a result, in the present embodiment, the RFID tag 70 is embedded in the bead portion 12 of the tire half body 17A outside the knitted fabric layer 41 and adjacent to the bead core 18.

[0104] The tire half 17A according to this embodiment is manufactured through the above steps. The tire manufacturing method is the same as that of the first embodiment.

[0105] The tire 110 of this embodiment is obtained through the above steps. Then, as shown in Fig. 10 and other figures, the RFID tag 70 in the resin skeleton 20 is embedded in the bead portion 12 of the tire 110.

[0106] Next, the actions and effects obtained by the tire 110 and the tire manufacturing method according to the present disclosure will be described.

[0107] (Actions and Effects) In the tire 110 according to this embodiment, the RFID tag 70 is disposed in the bead portion 12 on the outer side of the knit layer 41 in the tire width direction. Here, when the RFID tag 70 is disposed in the tire 110 having the resin skeleton 20, the RFID tag 70 is likely to be displaced from the desired position during manufacturing. On the other hand, in the tire 110 according to this aspect, the RFID tag 70 is disposed on the outer side of the knit layer 41 during the manufacturing process of the tire half body 17A, and therefore, the tire 110 according to this aspect is molded in a state where it is pressed against the inner surface 56I of the outer mold 56 together with the knit body 36 within the cavity C. Therefore, the tire 110 according to this aspect has improved positioning accuracy of the RFID tag 70.

[0108] Furthermore, in the tire 110 according to this embodiment, the RFID tag 70 is embedded in the resin skeleton 20 while being joined to the knitted layer 41, which makes it more difficult for the knitted layer 41 and the RFID tag 70 to become misaligned. As a result, the tire 110 according to this aspect has improved positioning accuracy of the RFID tag 70 compared to a case in which the RFID tag 70 is embedded in the resin skeleton 20 without being joined to the knitted layer 41.

[0109] Furthermore, in the tire 110 according to this embodiment, the RFID tag 70 is embedded in the bead portions 12 of the resin skeleton 20, and therefore deformation due to the load of the vehicle is unlikely to occur even when the tire 110 is in use. As a result, the durability of the RFID tag 70 in the tire 110 according to this aspect is higher than when the RFID tag 70 is embedded in a location other than the bead portions 12.

[0110] Furthermore, in the tire manufacturing method according to this embodiment, the primary molded body 134 is placed along the wall surface of the inner mold 52, and then the RFID tag 70 is placed on the opposite side of the knitted fabric layer 41 from the inner mold 52, so that the RFID tag can be pressed down by the knitted fabric layer when the resin material is injected. Therefore, according to the tire manufacturing method according to this aspect, the positioning accuracy of the RFID tag 70 can be improved in the manufacturing process of the tire 110 having the RFID tag 70 in the resin skeleton 20.

[0111] Furthermore, in the tire manufacturing method according to this embodiment, the resin material is injected from the radially inner end of the cavity C, and therefore the RFID tag 70 is pressed against the wall surface of the cavity C while being covered by the knitted layer 41 of the primary molded body 134. As a result, according to the tire manufacturing method according to this aspect, the positioning accuracy of the RFID tag 70 can be improved compared to when the resin material is injected from a location other than the radially inner end.

[0112] Furthermore, in the tire manufacturing method according to this embodiment, the RFID tag is disposed in the portion 46 adjacent to the bead core 18 in the cavity C, and therefore the RFID tag 70 is embedded in the bead portion 12 of the resin skeleton 20. Here, in a tire having the resin skeleton 20, the bead portion 12 is less likely to deform during use than other portions. Therefore, according to the tire manufacturing method according to this aspect, the durability of the RFID tag 70 in the tire 110 is increased compared to when the RFID tag 70 is disposed in a portion other than the portion 46 adjacent to the bead core 18.

[0113] (Modification) In the above description, the RFID tag 70 is disposed in the portion 46 of the cavity C adjacent to the bead core 18, but the tire manufacturing method in this embodiment is not limited to this. For example, the RFID tag 70 may be disposed in the side portion 14 or the crown portion 16, as long as it is disposed outside the knitted fabric layer 41. Even in this case, by disposing the RFID tag 70 outside the knitted fabric layer 41 of the bead portion 12 in the tire axial direction, the positioning accuracy of the RFID tag is improved compared to when the RFID tag 70 is embedded in a location other than the bead portion 12. Even in this case, the same actions and effects as those of the tire 110 described above can be obtained.

[0114] In other words, by embedding the RFID tag 70 on the inside or outside of the knitted layer 41 in the tire axial direction, the functions and effects shown in the tire 10 of the first embodiment or the tire 110 of the second embodiment can be obtained.

[0115] 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.

[0116] The disclosures of Japanese Patent Application Nos. 2023-209517 and 2023-209519, filed on December 12, 2023, are incorporated herein by reference in their 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 knitted layer having a knitted body formed from a first fiber material, the knitted body having a folded-back mesh that is continuous in the tire circumferential direction and the tire radial direction and is endless in the circumferential direction; and a reinforcing body formed from a reinforcing fiber material and woven into the knitted body at equal intervals in the tire circumferential direction and that regulates the elongation of the knitted body in the tire radial direction; a resin skeleton formed from a thermoplastic resin and in which the knitted layer is integrated from a bead portion in which a bead core is embedded to a crown portion; and an RFID tag embedded in the resin skeleton on the inner or outer side in the tire axial direction of the knitted layer.

2. The tire according to claim 1, wherein the RFID tag is embedded in the resin skeleton while being joined to the knitted layer.

3. A tire according to claim 1 or 2, wherein the RFID tag is embedded in the bead portion of the resin skeleton.

4. A tire manufacturing method comprising the steps of: forming a primary formed body by integrating an annular bead core with an inner end portion in the tire radial direction of a knitted layer having a knitted body formed of a first fiber material and having a folded-back mesh formed continuously in the tire circumferential direction and the tire radial direction, the knitted body having ends on both sides in the tire radial direction and being endless in the tire circumferential direction; and a reinforcing body formed of a reinforcing fiber material and woven into the knitted body at equal intervals in the tire circumferential direction while restricting extension of the knitted body in the tire radial direction; placing an RFID tag between the knitted layer and the inner mold while holding the bead core of the primary formed body at the inner end portion in the radial direction of an inner mold; forming a cavity using an outer mold facing a wall surface of the inner mold with a gap therebetween; and injecting a resin material into the cavity from a position inside the bead core in the tire axial direction of the inner mold, and forming a resin skeleton while pressing the primary formed body against the outer mold.

5. A tire manufacturing method according to claim 4, wherein in the step of forming a resin skeleton, a resin material is injected into the cavity from an inner end in the tire axial direction.

6. The steps of forming a primary formed body by integrating an annular bead core with an inner end in the tire radial direction of a knitted layer having a knitted body formed of a first fiber material and having a folded-back mesh formed continuously in the tire circumferential direction and the tire radial direction, the knitted body having ends on both sides in the tire radial direction and being endless in the tire circumferential direction, and a reinforcing body formed of a reinforcing fiber material and knitted into the knitted body at equal intervals in the tire circumferential direction and restricting extension of the knitted body in the tire radial direction, and forming a primary formed body; the steps of holding the bead core of the primary formed body at the inner end in the radial direction of an inner mold, and arranging the knitted layer along a wall surface of the inner mold; the steps of arranging an RFID tag on the side of the knitted layer opposite the inner mold; and the steps of forming a cavity using an outer mold facing the wall surface of the inner mold with a gap therebetween. injecting a resin material into the cavity from a position inside the inner mold in the tire axial direction relative to the bead core, and forming a resin skeleton while pressing the primary molded body against the outer mold.

7. A tire manufacturing method according to claim 6, wherein in the step of forming a resin skeleton, a resin material is injected from an inner end in the radial direction of the cavity.

8. A tire manufacturing method according to any one of claims 4 to 7, wherein in the step of placing the RFID tag, an RFID tag is placed in a portion of the knitted layer adjacent to the bead core.

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