Pneumatic tire

Abstract

To readily fit an RFID tag in a pneumatic tire that includes: a bead filler having an outside surface made of a resin material; and a carcass ply including a cord covered with a coating rubber.SOLUTION: A pneumatic tire 10 includes: a carcass 16 including a cord covered with a coating rubber; a bead filler part 18 having an outside surface opposite to the carcass 16 and made of a resin that is harder than the coating rubber; and an RFID tag 50 installed to the bead filler part 18.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pneumatic tire.

Background Art

[0002] Conventionally, an RFID tag has been embedded inside a tire, and information has been stored in the RFID tag or the stored information has been read by wireless communication. Various aspects have been proposed regarding the mounting position of the RFID. For example, in Patent Document 1, an RFID tag is provided on the inner side in the tire radial direction and the outer side in the tire width direction of the tire belt portion.

[0003] This is a technology for rubber tires such as Patent Document 1, and for a pneumatic tire having a resin material as a component of a part of the tire, it is necessary to consider the position where the RFID tag is provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to easily attach an RFID tag to a pneumatic tire having a bead filler with an outer surface made of a resin material and a carcass ply in which cords are coated with a coating rubber.

Means for Solving the Problems

[0006] The pneumatic tire according to the first aspect includes a carcass in which cords are coated with a coating rubber, a bead filler portion having an outer surface facing the carcass and formed of a resin harder than the coating rubber, and an RFID tag provided on the bead filler portion.

[0007] In the pneumatic tire according to the first aspect, since the RFID tag is provided in the bead filler portion formed of resin, it is easier to attach the RFID tag during manufacturing as compared with the case where the RFID tag is provided in the rubber portion. Therefore, in a pneumatic tire having a bead filler whose outer surface is made of a resin material and having a carcass ply in which the cord is coated with coating rubber, the RFID tag can be easily attached.

[0008] In the pneumatic tire according to the second aspect, in the cross-sectional shape, the bead filler portion has a thick portion in which the bead core is embedded and arranged on the inner side in the tire radial direction, and a thin portion arranged on the outer side in the tire radial direction and having a thickness in the tire width direction thinner than that of the thick portion, and the RFID tag is arranged in the thin portion of the bead filler portion.

[0009] In the pneumatic tire according to the second aspect, the RFID tag is arranged in the thin portion in the tire radial direction of the bead filler portion. Since the thin portion in the tire radial direction of the bead filler portion is arranged at a position away from the bead core, interference between the bead core and the RFID tag during communication can be suppressed.

[0010] In the pneumatic tire according to the third aspect, the RFID tag is arranged in the inner peripheral portion in the tire width direction of the bead filler portion.

[0011] In the pneumatic tire according to the third aspect, the RFID tag is arranged in the inner peripheral portion in the tire width direction of the bead filler portion. The inner peripheral portion in the tire width direction of the bead filler portion is relatively difficult to deform during running, and damage to the RFID tag can be suppressed.

[0012] No. 1 The tire according to the aspect has a resin coating portion in which the main body chip and the antenna are embedded. The resin material forming the resin coating portion is the same type of material as the resin material forming the bead filler portion.

[0013] In the tire according to the fourth aspect, the resin coating portion of the RFID tag can be easily integrated with the bead filler portion by melting or the like.

Advantages of the Invention

[0014] As described above, according to the pneumatic tire of the present invention, in a pneumatic tire having a bead filler whose outer surface is made of a resin material and having a carcass ply in which cords are coated with a coating rubber, an RFID tag can be easily attached.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0016] Referring to FIGS. 1 to 5, a pneumatic tire 10 according to an embodiment of the present invention will be described. In the drawings, the arrow R direction indicates the tire radial direction, and the arrow W direction indicates the tire width direction. The tire radial direction means a direction orthogonal to the tire rotation axis (not shown). The tire width direction means a direction parallel to the tire rotation axis. The tire width direction can also be referred to as the tire axis direction.

[0017] The method for measuring the dimensions of each part is based on the method described in the 2021 edition YEAR BOOK issued by JATMA (Japan Automobile Tire Manufacturers Association). When the TRA standard or ETRTO standard is applied at the place of use or manufacturing, follow each standard.

[0018] As shown in FIG. 1, the pneumatic tire 10 of the present embodiment is a so-called radial pneumatic tire used for, for example, a passenger car, and includes a pair of bead portions 20 in which bead cores 12 are embedded. A carcass 16 composed of a single carcass ply 14 straddles between one bead portion 20 and the other bead portion 20. Note that FIG. 1 shows the shape of the pneumatic tire 10 before air filling (internal pressure = atmospheric pressure) in a natural state when mounted on a standard rim 19.

[0019] The carcass ply 14 is formed by coating a plurality of cords 13A (not shown in FIG. 1, see FIG. 2) extending in the radial direction of the pneumatic tire 10 with a coating rubber 13B (not shown in FIG. 1, see FIG. 2). That is, the pneumatic tire 10 of the present embodiment is a so-called radial pneumatic tire. The material of the cords 13A of the carcass ply 14 is, for example, PET, but other conventionally known materials may also be used.

[0020] The carcass 16 has end portions in the tire width direction where the bead cores 12 are folded back radially outward of the tire. The carcass 16 has a portion straddling from one bead core 12 to the other bead core 12 called a main body portion 16A, and a portion folded back from the bead core 12 called a folded-back portion 16B.

[0021] Between the main body portion 16A and the folded-back portion 16B of the carcass 16, a bead filler portion 18 is disposed. The bead filler portion 18 gradually decreases in thickness from the bead core 12 toward the outer side in the tire radial direction. In the pneumatic tire 10 of the present embodiment, the entire portion inside the tire radial direction from the outer end 18A in the tire radial direction of the bead filler portion 18 is defined as the bead portion 20.

[0022] (Bead core) As shown in FIG. 3, the bead core 12 of the present embodiment has a bead cord 12B covered with a covering layer 12A. As an example, the bead core 12 of the present embodiment is formed by winding a single bead cord 12B covered with a covering layer 12A made of a resin material for covering and joined with the covering layer 12A a plurality of times in the tire circumferential direction, and joining the covering layers 12A of adjacent bead cords 12B by welding. In other words, the bead core 12 of the present embodiment has a structure in which the outer surface is the covering layer 12A and the bead cord 12B is embedded inside.

[0023] Here, as the bead cord 12B, it is preferable to use a monofilament (single wire) such as a metal fiber or an organic fiber, or a multifilament (twisted wire) obtained by twisting a metal fiber or an organic fiber. As the metal fiber, it is preferable to use a steel fiber or the like, and as the organic fiber, it is preferable to use an aromatic polyamide fiber, an aliphatic polyamide (nylon) fiber, or the like. Note that the metal fiber and the organic fiber are not limited to the above-described fibers. In the present embodiment, a steel monofilament is used as the bead cord 12B.

[0024] In the present embodiment, the covering layer 12A is formed of a thermoplastic material having thermoplasticity (for example, a thermoplastic resin, a thermoplastic elastomer, etc.). Further, the covering layer 12A is formed of a resin material for covering having a higher tensile elastic modulus than the coating rubber 13B that covers the cord 13A of the carcass ply 14.

[0025] (Bead filler portion) As shown in FIG. 1, the bead filler portion 18 is disposed between the main body portion 16A and the folded-back portion 16B of the carcass 16. The bead filler portion 18 of the present embodiment is formed of a resin material, and as an example, is formed of a thermoplastic material having thermoplasticity (for example, a thermoplastic resin, a thermoplastic elastomer, etc.). The bead filler portion 18, the bead core 12, and the RFID tag 50 described later can be integrally formed in advance and sandwiched by the carcass 16 for tire molding. Before vulcanization of the tire, as an example, as shown in FIG. 3, in terms of cross-sectional shape, the bead filler portion 18 has a thick portion 18B in which the bead core 12 is embedded and disposed on the inner side in the tire radial direction, and a thin portion 18C disposed on the outer side in the tire radial direction and extending in the tire radial direction and having a thickness in the tire width direction thinner than that of the thick portion 18B. It is sandwiched by the carcass 16 and disposed in a vulcanization mold, and after vulcanization molding, the bead filler portion 18 is designed to have the shape shown in FIG. 1.

[0026] The bead filler portion 18 may be formed of the same material as the coating resin material forming the coating layer 12A, or may be formed of a different material.

[0027] The bead filler portion 18 is formed of a resin material having a higher tensile elastic modulus (in other words, harder) than the side rubber layer 24 in order to ensure the bending rigidity of the bead portion 20. Further, the bead filler portion 18 is formed of a resin material having a higher tensile elastic modulus than the coating rubber 13B covering the cord 13A of the carcass 16.

[0028] Incidentally, the tensile elastic modulus (Young's modulus) of the coating rubber 13B of the carcass 16 is set within a range of 10 to 200 MPa as an example.

[0029] The tensile elastic modulus of the resin material forming the coating layer 12A of the bead core 12 is higher than the tensile elastic modulus of the coating rubber 13B, and is set within a range of 100 to 1000 MPa as an example.

[0030] The tensile elastic modulus of the resin material forming the bead filler portion 18 is higher than that of the coating rubber 13B, and is set, for example, within the range of 100 to 1000 MPa.

[0031] There is no limitation on the value of the tensile elastic modulus for the coating layer 12A of the bead core 12 and the bead filler portion 18, and either one may be harder or they may be the same.

[0032] An inner liner 22 made of rubber is disposed inside the pneumatic tire of the carcass 16. On the other hand, a side rubber layer 24 is disposed outside the carcass 16 in the tire width direction. The side rubber layer 24 extends by folding back the radially inner portion of the bead core 12 to a part of the inner surface of the tire.

[0033] In the present embodiment, a tire case 25 is constituted by the bead core 12, the carcass 16, the bead filler portion 18, the inner liner 22, and the side rubber layer 24. In other words, the tire case 25 is a tire skeleton member that forms the skeleton of the pneumatic tire 10.

[0034] (Belt) A belt 26 is disposed outside the crown portion of the carcass 16, in other words, outside the carcass 16 in the tire radial direction. The belt 26 of the present embodiment is formed flat when viewed in a cross section along the tire rotation axis, in other words, is formed linearly from one end in the width direction to the other end, and is in close contact with the outer peripheral surface of the carcass 16 except for a part on both sides in the width direction. The belt 26 of the present embodiment is formed by winding a resin-coated cord 34 obtained by coating a plurality of (two in the present embodiment) reinforcing cords 30 with a resin 32.

[0035] (Layer) Near the end 26A in the tire width direction of the belt 26, it is covered from the outside in the tire radial direction by a belt-like layer 38. The layer 38 preferably covers at least the outermost reinforcing cord 30 in the tire width direction of the belt 26 from the outside in the tire radial direction. In this embodiment, from the outermost in the tire width direction to the second reinforcing cord 30 are covered by the layer 38. Further, the layer 38 extends outward in the tire width direction from the end 26A of the belt 26.

[0036] (Tread) On the outside in the tire radial direction of the belt 26, a tread 36 made of a rubber material is disposed. As the rubber material used for the tread 36, those conventionally well-known are used. In the tread 36, grooves 37 for drainage are formed. Also, as the pattern of the tread 36, those conventionally well-known are used.

[0037] (RFID tag) An RFID tag 50 is provided in the bead filler portion 18. The RFID tag 50 is disposed on the inner peripheral portion in the tire width direction of the bead filler portion 18. As shown in FIG. 3, the RFID tag 50 can be joined to the thin portion 18C of the bead filler portion 18 before tire vulcanization.

[0038] As shown in FIGS. 4(A) and 4(B), the RFID tag 50 includes a main body chip 52 and an antenna 54. The main body chip 52 includes a processor including a CPU or MPU and a memory capable of storing various information. The antenna 54 extends from the main body chip 52 to one side and the other side.

[0039] The main body chip 52 and the antenna 54 are embedded in a resin coating portion 56 formed of a resin material. The resin material forming the resin coating portion 56 is preferably the same type of material as the resin material forming the bead filler portion 18. The embedding in the resin coating portion 56 may be sandwiched with a film-like one, or the thickness of the main body chip 52 may be absorbed by the thick resin coating portion 56. The RFID tag 50 has flexibility in the thickness direction as shown in FIG. 4(B).

[0040] As shown in FIG. 5, the RFID tag 50 is arranged such that the longitudinal direction in which the antenna 54 extends is along the tire circumferential direction. In this way, by arranging the longitudinal direction of the RFID tag 50 along the tire circumferential direction, compared with a configuration in which the longitudinal direction is arranged along the tire radial direction, the antenna 54 is pulled following the deformation of the tire case 25 during running, and it is possible to suppress the antenna 54 from coming off the main body chip 52.

[0041] (Function, Effect) Next, the function and effect of the pneumatic tire 10 of the present embodiment will be described. In the pneumatic tire 10 of the present embodiment, since the RFID tag 50 is provided in the bead filler portion 18 formed of resin, the RFID tag can be easily attached during manufacturing as compared with the case where the RFID tag is provided in the rubber portion. In particular, as in the present embodiment, by embedding the main body chip 52 and the antenna 54 of the RFID tag 50 in the resin coating portion 56, the joining with the bead filler portion 18 of the resin material can be easily performed.

[0042] Further, in the present embodiment, the RFID tag 50 is arranged at the inner peripheral portion in the tire width direction of the thin portion 18C of the bead filler portion 18. Since the thin portion 18C is generally arranged at a position away from the bead core 12, interference between the bead core 12 and the RFID tag 50 during communication can be suppressed. In addition, since the inner peripheral portion in the tire width direction is less likely to deform during running as compared with the outer peripheral portion, damage to the RFID tag 50 can be suppressed.

[0043] In the present embodiment, the RFID tag 50 is arranged at the inner peripheral portion in the tire width direction of the thin portion 18C of the bead filler portion 18, but it is not necessarily at this position. As shown in FIG. 6, the RFID tag 50 may be arranged at the outer peripheral portion in the tire width direction of the thin portion 18C. Further, as shown in FIG. 7, the RFID tag 50 may be arranged at the intermediate portion in the tire width direction of the bead filler portion 18.

[0044] Furthermore, in this embodiment, the bead filler portion 18 is shaped to have a thin-walled portion 18C as the shape before being sandwiched and molded by the carcass 16. However, as shown in FIG. 8(A), a short bead filler portion 18D without the thin-walled portion 18C may be used, and the RFID tag 50 may be disposed at the inner peripheral portion in the tire width direction. In this case, a recess may be provided in the bead filler portion 18D to be flush with the surface of the bead filler portion 18D. Also, as shown in FIG. 8(B), a short bead filler portion 18D may be used, and the RFID tag 50 may be disposed at the outer peripheral portion in the tire width direction.

[0045] Also, in this embodiment, the RFID tag 50 is disposed such that its longitudinal direction is along the tire circumferential direction. However, the RFID tag 50 may be disposed such that its longitudinal direction is along the tire radial direction.

[0046] Note that the structure of the present invention can also be applied to a run-flat pneumatic tire whose side portion is reinforced with reinforcing rubber, and can also be applied to a pneumatic tire mounted on a vehicle other than a passenger car.

Explanation of Reference Numerals

[0047] 10…Pneumatic tire, 12…Bead core, 13A…Cord, 13B…Coating rubber, 16…Carcass 18…Bead filler portion, 18B…Thick-walled portion, 18C…Thin-walled portion 50…RFID tag, 56…Resin coating portion

Claims

1. A carcass with a cord coated with coating rubber, A bead filler portion formed of a resin harder than the coating rubber on an outer surface facing the carcass, An RFID tag provided on the bead filler portion, having, The RFID tag has a resin coating portion for embedding a main body chip and an antenna, and the resin material forming the resin coating portion is the same type of material as the resin material forming the bead filler portion, A pneumatic tire.

2. In terms of cross-sectional shape, the bead filler portion has a thick portion in which a bead core is embedded and arranged on the inner side in the tire diameter direction, and a thin portion arranged on the outer side in the tire diameter direction and having a smaller thickness in the tire width direction than the thick portion, The RFID tag is arranged in the thin portion of the bead filler portion. The pneumatic tire according to claim 1.

3. The RFID tag is arranged on the inner surface portion in the tire width direction of the bead filler portion. The pneumatic tire according to claim 1.

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