pneumatic tires

Abstract

The present invention provides a pneumatic tire that can improve the communication performance of electronic components and the durability of the pneumatic tire and electronic components. [Solution] The pneumatic tire 1 includes at least one electronic component 21. The electronic component 21 is covered with a cover rubber having an electrical resistivity of 1.0 × 10¹⁰ Ω·cm or more. When the height Ha of the bead apex rubber 8 from the outer surface 5a of the bead core 5 in the tire radial direction is less than 25 mm, the electronic component 21 is positioned in a region of 5 mm or more and 25 mm or less from the outer surface 5a of the bead core 5 in the tire radial direction. When the height Ha of the bead apex rubber 8 is 25 mm or more, the electronic component 21 is positioned in a region A2 that is 5 mm or more from the outer surface 5a of the bead core 5 in the tire radial direction and is less than or equal to the outer edge 8e of the bead apex rubber 8 in the tire radial direction.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 below describes a pneumatic tire provided therein with an electronic component capable of communicating with the outside, such as an RFID (Radio Frequency Identification) tag. In Patent Document 1 below, the electronic component is provided outside the carcass in the tire axial direction, and the silica content of the rubber member disposed outside the electronic component is defined. Thereby, the tire of Patent Document 1 below is said to be able to secure sufficient reading performance of the electronic component and suppress a decrease in the durability of the tire.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, in the pneumatic tire as described above, it has been desired to improve the communication performance (reading performance) of the electronic component and the durability performance of the pneumatic tire and the electronic component.

[0005] The present invention has been devised in view of the above actual situation, and the main problem is to provide a pneumatic tire capable of improving the communication performance of the electronic component and the durability performance of the pneumatic tire and the electronic component.

Means for Solving the Problems

[0006] The present invention is a pneumatic tire including a pair of bead portions and at least one electronic component, and the electronic component has an electrical resistivity of 1.0×1010 The tire is covered with a cover rubber of Ω·cm or more, and each of the pair of bead portions is provided with a bead core and a bead apex rubber extending outward in the tire radial direction from the outer surface of the bead core, and when the height of the bead apex rubber from the outer surface of the bead core in the tire radial direction is less than 25 mm, the electronic component is arranged in a region of 5 mm or more and 25 mm or less outward in the tire radial direction from the outer surface of the bead core, and when the height of the bead apex rubber is 25 mm or more, the electronic component is arranged in a region of 5 mm or more outward in the tire radial direction from the outer surface of the bead core and below the outer end of the bead apex rubber in the tire radial direction. [Effects of the Invention]

[0007] By adopting the above configuration, the pneumatic tire of the present invention can improve the communication performance of electronic components and the durability of the pneumatic tire and electronic components. [Brief explanation of the drawing]

[0008] [Figure 1] This is a meridian cross-sectional view of a pneumatic tire according to one embodiment of the present invention. [Figure 2] This is a magnified perspective view of an electronic component. [Figure 3] This is a meridional cross-section of a pneumatic tire with a bead apex rubber height of less than 25 mm. [Figure 4] This is an enlarged cross-sectional view of the carcass, inner liner layer, and electronic components. [Figure 5] This is an enlarged cross-sectional view of the bead portion showing the first element. [Figure 6] This is a cross-sectional view of an electronic component as seen from the direction of the tire's rotation axis. [Figure 7] This is a meridian cross-sectional view of the right half of a pneumatic tire in another embodiment. [Figure 8] This is a front view of the reinforcing rubber layer formed as a pneumatic tire, as seen from the direction of the tire's rotation axis. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The drawings contain exaggerations and representations that differ from the actual structural dimensional ratios in order to aid in understanding the present invention. Furthermore, where there are multiple embodiments, the same or common elements are denoted by the same reference numerals throughout the specification, and redundant descriptions are omitted.

[0010] Figure 1 is a meridian cross-sectional view of a pneumatic tire 1 (hereinafter sometimes simply referred to as "tire") in its normal state, including the tire rotation axis Tc, showing one embodiment of the present invention. The present invention is suitably used, for example, as a tire for a passenger car. The present invention may also be used as a tire for heavy loads or for motorcycles.

[0011] The aforementioned "normal condition" refers to a state in which, in the case of pneumatic tires for which various standards are defined, the tire is mounted on a standard rim, filled to the standard internal pressure, and is under no load. In the case of tires for which various standards are not defined, the aforementioned "normal condition" means a standard operating condition according to the intended use of the tire, and is under no load. In this specification, unless otherwise specified, the dimensions of each part of the tire are values ​​measured under the aforementioned "normal condition."

[0012] A "standard rim" is the rim defined for each tire within the standards system that the tire is based on. For example, it is the "standard rim" for JATMA, the "Design Rim" for TRA, and the "Measuring Rim" for ETRTO.

[0013] "Regular internal pressure" refers to the air pressure specified for each tire by each standard within the tire standard system, including the standard on which the tire is based. For JATMA, it is the "maximum air pressure," for TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES," and for ETRTO, it is the "INFLATION PRESSURE."

[0014] As shown in FIG. 1, the tire 1 of the present embodiment includes a pair of bead portions 4 and at least one electronic component 21. Further, the tire 1 includes a pair of sidewall portions 3 each connected to one of the pair of bead portions 4, and a tread portion 2 connected to each of the pair of sidewall portions 3.

[0015] Each of the pair of bead portions 4 is provided with a bead core 5 and a bead apex rubber 8 extending outward in the tire radial direction from the outer surface 5a of the bead core 5 in the tire radial direction.

[0016] FIG. 2 is an enlarged perspective view of the electronic component 21. As shown in FIG. 2, the electronic component 21 is covered with a cover rubber 22. The cover rubber 22 has an electrical resistivity of 1.0×10 10 Ω·cm or more. Such a cover rubber 22 can suppress noise, radio wave interference, etc. generated in the electronic component 21, so that the communication performance can be improved. Further, the cover rubber 22 can suppress the contact between the electronic component and other tire constituent members, and improve the durability performance of the electronic component. In this specification, the member composed of the electronic component 21 and the cover rubber 22 is defined as an electronic module 20.

[0017] Furthermore, the present invention is based on the discovery that the region of low circumferential shear strain differs depending on whether the height Ha of the bead apex rubber 8 from the outer surface 5a (outer end in the tire radial direction) of the bead core 5 is greater than or less than 25 mm. Figure 3 is a meridional cross-sectional view of the left half of a tire 1 in which the height Ha of the bead apex rubber 8 is less than 25 mm. As shown in Figure 3, when the height Ha of the bead apex rubber 8 is less than 25 mm, the circumferential shear strain generated in the electronic component 21 can be reduced by placing the electronic component 21 in a region A1 that extends 5 mm or more and 25 mm or less radially outward from the outer surface 5a of the bead core 5. Figure 1 is a meridional cross-sectional view of a tire 1 in which the height Ha of the bead apex rubber 8 is 25 mm or more. As shown in Figure 1, when the height Ha of the bead apex rubber 8 is 25 mm or more, the electronic component 21 is positioned in region A2, which is 5 mm or more outward in the tire radial direction from the outer surface 5a of the bead core 5, and below the outer edge 8e of the bead apex rubber 8 in the tire radial direction. This reduces the shear strain in the tire circumferential direction that occurs in the electronic component 21. Therefore, damage to the tire 1 originating from the electronic component 21, and damage to the electronic component 21 itself, can be suppressed, thereby improving the durability of both the electronic component 21 and the tire 1. Furthermore, if the electronic component 21 is located too close to the bead core 5, the reading performance of the electronic component 21 deteriorates due to the influence of the bead core 5. In particular, if the bead wire (not shown) of the bead core 5 is made of metal such as steel, the reading performance of the electronic component 21 deteriorates. For this reason, by not positioning the electronic component 21 less than 5 mm outward in the tire radial direction from the outer surface 5a, the reading performance of the electronic component 21 can be maintained at a high level.

[0018] As shown by way of example in Fig. 1, the tire 1 further includes a toroidal carcass 6 extending between bead cores 5 of a pair of bead portions 4, and a toroidal inner liner layer 10 extending between the pair of bead portions 4 inside the carcass 6. Further, the tire 1 includes a sidewall rubber 3G forming the sidewall portion 3, and a clinch rubber 4G of a well-known structure forming the bead portion 4. The sidewall rubber 3G and the clinch rubber 4G are configured with a well-known structure.

[0019] The carcass 6 of the present embodiment is, for example, composed of a single carcass ply 6A. The carcass ply 6A includes, for example, a body portion 6a and a turned-up portion 6b. The body portion 6a extends between, for example, two bead portions 4. The turned-up portion 6b is connected to the body portion 6a and is turned up from the inner side in the tire axial direction to the outer side around the bead core 5. In the present embodiment, the outer end 6e in the tire radial direction of the turned-up portion 6b is located on the outer side in the tire radial direction with respect to the tire maximum width position M. Note that the outer end 6e in the tire radial direction of the turned-up portion 6b may be located on the inner side in the tire radial direction with respect to the tire maximum width position M. The tire maximum width position M is specified by the outermost point in the tire axial direction of the carcass ply 6A. In the tread portion 2, a belt layer 7 of a well-known structure is provided on the outer side in the tire radial direction of the carcass 6.

[0020] Fig. 4 is an enlarged view schematically showing a cross section near the electronic component 21 shown in Fig. 1. Fig. 4 shows the carcass ply 6A, the inner liner layer 10, and the electronic component 21. As shown in Fig. 4, the carcass ply 6A includes a plurality of carcass cords 15 (only one carcass cord 15 is shown in Fig. 4) and a topping rubber layer 16 covering the plurality of carcass cords 15.

[0021] For example, an organic fiber cord such as aramid or rayon is adopted for the carcass cord 15. The carcass cords 15 are preferably arranged, for example, at an angle (not shown) of 70 to 90° with respect to the tire equator C.

[0022] Examples of rubber components for the topping rubber layer 16 include diene rubbers such as isoprene rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), and styrene-isoprene-butadiene copolymer rubber (SIBR). These may be used individually or in combination of two or more. Among these, isoprene rubber, SBR, and BR are preferred.

[0023] The inner liner layer 10 is positioned inside the carcass 6 and constitutes the inner surface 1i of the tire. In this embodiment, the inner liner layer 10 includes an inward-facing surface 10a that constitutes the inner surface 1i of the tire, and an outward-facing surface 10b that faces in the opposite direction to the inward-facing surface 10a and towards the carcass ply 6A. The inner liner layer 10 has an extremely low air permeability and can maintain the internal pressure of the tire. The inner liner layer 10 contains, for example, 80% by mass or more of butyl-based rubber such as butyl rubber or halogenated butyl rubber. Thus, the inner liner layer 10 employs a well-known configuration.

[0024] The tire 1 of this embodiment includes an adhesive rubber layer 12 disposed on the outer side of the inner liner layer 10 in the tire axial direction. The adhesive rubber layer 12 is disposed, for example, sandwiched between the inner liner layer 10 and the carcass 6 (carcass ply 6A). In this embodiment, the adhesive rubber layer 12 extends in a toroidal shape between a pair of bead portions 4. The adhesive rubber layer 12 enhances the adhesion between the carcass ply 6A and the inner liner layer 10, thereby suppressing their delamination. Preferably, the adhesive rubber layer 12 is made of an elastomer composition containing, for example, natural rubber or styrene-butadiene rubber. In this embodiment, the adhesive rubber layer 12 employs a well-known configuration.

[0025] As shown in Figures 1 and 3, the bead apex rubber 8 of this embodiment is formed from a hard rubber having a tapered cross-section that extends outward from the inside to the outside in the tire axial direction toward the radially outward direction of the tire. The outer end 8e of the bead apex rubber 8 is located radially inward from the tire's maximum width position M. The bead apex rubber 8 is formed from a hard rubber with a rubber hardness of, for example, 50 degrees or more, and more preferably 60 degrees or more. The rubber hardness is the durometer A hardness measured at 23°C using a durometer type A based on JIS-K6253. Furthermore, it is desirable that the complex modulus of elasticity E* of the bead apex rubber 8 is 2 to 40 MPa, more preferably 10 to 30 MPa. In addition, it is desirable that the loss tangent tanδ of the bead apex rubber 8 is 0.08 to 0.15. The complex modulus of elasticity E* and the loss tangent tanδ are values ​​measured under the following conditions in accordance with the provisions of JIS-K6394, and are measured using test specimens taken from bead apex rubber 8. Initial strain: 10% Amplitude: ±2% Frequency: 10Hz Deformation mode: Tension Measurement temperature: 70℃ Viscoelastic spectrometer: Manufactured by Iwamoto Manufacturing Co., Ltd. The aforementioned test specimen: length 20 mm × width 4 mm × thickness 1 mm (the tire circumference is the length direction of the test specimen, and the tire axis direction is the thickness direction of the test specimen).

[0026] The bead core 5 has a polygonal cross-sectional shape, for example, by winding a bead wire (not shown) in multiple rows and layers. The bead core 5 in this embodiment has a substantially square cross-sectional shape. The bead core 5 includes an outer surface 5a adjacent to the bead apex rubber 8, an inner surface 5b facing inward in the tire radial direction opposite to the outer surface 5a, and a pair of side surfaces 5c connecting the outer surface 5a and the inner surface 5b. The bead wire employs a well-known configuration and is, for example, made of steel.

[0027] To improve the reading performance of the electronic component 21, in both cases where the height Ha of the bead apex rubber 8 is less than 25 mm (the configuration shown in Figure 3) and where the height Ha of the bead apex rubber 8 is 25 mm or more (the configuration shown in Figure 1), it is desirable to position the electronic component 21 at a position of 10 mm or more outward in the tire radial direction from the outer surface 5a of the bead core 5, and more preferably at a position of 12 mm or more. Furthermore, it is desirable to position the electronic component 21 in region A3 between a position that is 5 mm or more outward in the tire radial direction from the outer surface 5a and the tire's maximum width position M. Placing the electronic component 21 in region A1 to A3 means that the entire main body portion 21a, described later, is placed within region A1 to A3, and preferably, the entire electronic component 21 is placed within region A1 to A3. Furthermore, placing the electronic component 21 in region A1 to A3 means that the entire electronic module 20 is placed within region A1 to A3.

[0028] Furthermore, it is even more desirable that the electronic component 21 be located in a low-strain region (not shown) where the sum of strains is 60% or less of the maximum value of the sum of strains. This further improves the durability of the tire 1 and the electronic component 21. The "strain" is numerical data output from the results (for example, the finite element method) of a tire simulation (a rolling simulation in which the tire model is rolled at least once) using the computer described in Japanese Patent Publication No. 4608306 (hereinafter referred to as "the Patent Publication"). The "strain" is output, for example, from a plurality of "first elements e1" (shown in Figure 5) described in the Patent Publication. The "sum of strain" is the sum of six components of strain, consisting of the normal strain in the tire meridian direction, tire circumferential direction, and tire thickness direction, respectively, the shear strain of shear deformation in the tire meridian direction, the shear strain of shear deformation in the tire circumferential direction, and the shear strain of shear deformation in the tire thickness direction, as described in the Patent Publication.

[0029] The first element e1 is assigned, for example, to the clinch rubber 4G, sidewall rubber 3G, adhesive rubber layer 12, bead apex rubber 8 and / or inner liner layer 10 (shown in Figure 1). Figure 5 is an enlarged cross-sectional view of the bead portion 4 showing the first element e1 of this embodiment. As shown in Figure 5, a plurality of first elements e1 are assigned to the inner liner layer 10 in this embodiment. The first element e1 of this embodiment is assigned to the first element E1 that constitutes the outward-facing surface 10b of the inner liner layer 10. The first element E1 is arranged, for example, continuously across the inner and outer surfaces of the inner liner layer 10 in the tire radial direction. In this embodiment, the first element E1 is assigned between the tire radial height position of the outer surface 5a of the bead core 5 and the tire radial height position of the tire radial outer end 6e (shown in Figure 1) of the folded portion 6b of the carcass ply 6A. Furthermore, the first element e1 may be cracked against the adhesive rubber layer 12 adjacent to the outward-facing surface 10b.

[0030] Furthermore, the "boundary conditions" described in the aforementioned patent publication include, for example, the tire 1 in a normal state with a normal load applied, the rotational speed based on the assumed maximum speed of the tire 1, and the coefficient of friction of the road surface on which the tire 1 is assumed to travel. It is even more desirable that the low strain region is such that the sum of strains is 50% or less of the maximum value of the sum of strains. As shown in Figure 5, the calculation of the low strain region is performed with the tire 1 without any electronic components 21 installed.

[0031] The aforementioned "standard load" refers to the load specified for each tire by each standard within the standards system that the tire is based on. For example, it is the "maximum load capacity" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and the "LOAD CAPACITY" for ETRTO.

[0032] The electronic component 21 is positioned between the carcass 6 and the inner liner layer 10. In this embodiment, one electronic component 21 is positioned on one of the pair of bead portions 4 (the left side in Figure 1). However, the configuration is not limited to this, and the electronic component 21 may be positioned on both sides of the bead portion 4, for example. Furthermore, multiple electronic components 21 may be provided on the circumference of the tire.

[0033] As shown in Figure 4, the electronic component 21 is positioned between the inner liner layer 10 and the adhesive rubber layer 12 so as not to come into contact with the topping rubber layer 16. This allows the tire 1 of this embodiment to suppress damage caused by contact between the electronic component 21 and the carcass cord 15, even when repeated deformation occurs during driving.

[0034] The electronic component 21 consists of, for example, an RFID tag, a pressure sensor, a temperature sensor, an acceleration sensor, and a magnetic sensor. In this embodiment, the electronic component 21 is an RFID tag. When an RFID tag receives a query radio wave, it uses this as electrical energy and transmits various data stored in its memory as a response radio wave. Such an RFID tag employs a known configuration.

[0035] As shown in Figure 2, the electronic component 21 of this embodiment includes a main body 21a equipped with an IC chip and a coil-shaped antenna 21b. The IC chip is composed of, for example, a transmitting and receiving circuit, a control circuit, a memory, etc. In this embodiment, the antenna 21b includes a coil portion 24a in which metal wires are wound spirally and an internal coil space 24b in which the coil central axis K1 of the coil portion 24a is located.

[0036] In this embodiment, the electronic component 21 is not directly connected to the antenna 21b and the main body 21a, and the main body 21a is located in the internal coil space 24b of the antenna 21b. As a result, the main body 21a is protected by the antenna 21b, further improving the durability of the electronic component 21. The main body 21a is held, for example, by contacting the outer surface of the wires of the coil portion 24a. The spiral outer diameter d1 of the antenna 21b (shown in Figure 4) is, for example, 1.5 to 2.5 mm, preferably 1.8 to 2.0 mm. The total length of the electronic component 21 (including the antenna 21b) is, for example, about 35 to 50 mm.

[0037] The cover rubber 22 may be made of a known rubber with excellent adhesive properties. The cover rubber 22 may be made of the same rubber as the topping rubber layer 16 of the carcass ply 6A (shown in Figure 2).

[0038] The cover rubber 22 has a total length greater than the total length of the electronic component 21 so that it can completely cover the electronic component 21. The cover rubber 22 is, for example, constructed in a rectangular parallelepiped shape. The length La of the cover rubber 22 is the length in the longitudinal direction of the antenna 21b (direction of the coil central axis K1), and is, for example, 45 to 70 mm. The width Lb of the cover rubber 22 is the length in the direction perpendicular to the longitudinal direction of the antenna 21b, and is smaller than the length La, for example, 8 to 15 mm. The thickness ta is the thickness in the direction perpendicular to the length La and width Lb, and is smaller than the length La and width Lb, for example, 2.0 to 3.0 mm, preferably 2.2 to 2.4 mm.

[0039] The cover rubber 22 of this embodiment includes an outer layer 26 in contact with the adhesive rubber layer 12 (shown in Figure 4) and an inner layer 27 in contact with the inner liner layer 10 (shown in Figure 4). In this embodiment, the electronic component 21 is positioned between the outer layer 26 and the inner layer 27 of the cover rubber 22. The thickness t1 of the inner layer 27 and the thickness t2 of the outer layer 26 are preferably 0.8 to 1.5 mm, and more preferably 1.0 to 1.3 mm, respectively. This further improves durability.

[0040] Figure 6 is a cross-sectional view of the tire 1 cut parallel to the tire equator C (shown in Figure 1) at the location where the electronic component 21 is installed. As shown in Figure 6, when viewed from the direction of the tire rotation axis Tc, the electronic component 21 is positioned such that the coil center axis K1 of the antenna 21b is at an angle θ1 of 45 degrees or less with respect to the tire circumferential direction. This reduces the load on the electronic component 21 during driving, thereby improving the durability of the electronic component 21 and the tire 1 (carcass cord 15). The angle θ1 is the angle between the tangent Yn of the tire circumferential line Y1 passing through the midpoint 21c in the longitudinal direction of the antenna 21b and the coil center axis K1. The angle θ1 is preferably within 25 degrees, and in this embodiment, it is 0 degrees.

[0041] Figure 7 is a meridian cross-sectional view of the right half of a tire 1 in another embodiment. As shown in Figure 7, the tire 1 in this embodiment includes a carcass 6 and a reinforcing rubber layer 30. The carcass 6 is composed of, for example, two carcass plies 6A and 6B arranged inside and outside the tire radially. In this embodiment, the outer end 6e in the tire radial direction of the folded portion 6b of the inner carcass ply 6A is located further outward in the tire radial direction than the outer end 6i in the tire radial direction of the folded portion 6b of the outer carcass ply 6B. The height Ha of the bead apex rubber 8 in this embodiment is 25 mm or more.

[0042] The reinforcing rubber layer 30 is located, for example, between the bead apex rubber 8 and the folded portion 6b of the outer carcass ply 6B. In this embodiment, the reinforcing rubber layer 30 extends inward and outward in the tire radial direction from the outer end 8e of the bead apex rubber 8 in the tire radial direction. The outer end 30e of the reinforcing rubber layer 30 in the tire radial direction is located inward from the outer end 6e of the folded portion 6b of the inner carcass ply 6A in the tire radial direction. The inner end 30i of the reinforcing rubber layer 30 in the tire radial direction is located inward from the outer end 6i of the folded portion 6b of the outer carcass ply 6B in the tire radial direction, and outward from the outer surface 5a of the bead core 5 in the tire radial direction. In this embodiment, the reinforcing rubber layer 30 is located, for example, on both sidewall portions 3 (only one is shown in Figure 7). The reinforcing rubber layer 30 includes, for example, a plurality of reinforcing cords 30a (shown in Figure 8) and a topping rubber 30b covering these reinforcing cords 30a. Such a reinforcing rubber layer 30 increases the rigidity of the sidewall portion 3 or the bead portion 4, thereby improving the durability of the tire 1. In this embodiment, the reinforcing cord 30a is made of metal, for example, steel.

[0043] Figure 8 is a front view of the reinforcing rubber layer 30 formed as tire 1, viewed from the direction of the tire rotation axis Tc. As shown in Figure 8, it is desirable that the reinforcing cord 30a be arranged so as not to be parallel to the coil center axis K1 of antenna 21b. This suppresses radio wave interference and the like that occurring in electronic components 21. In order to maintain high communication performance, the angle θ2 between the reinforcing cord 30a and the coil center axis K1 is preferably 40 degrees or more, more preferably 65 degrees or more, preferably 140 degrees or less, and more preferably 115 degrees or less. In this embodiment, the angle θa of the reinforcing cord 30a with respect to the tire circumferential direction is set to 19 to 26 degrees. Angle θa is the angle with respect to the tangent (not shown) of the tire circumferential line Y2 at the midpoint 30c in the longitudinal direction of the reinforcing cord 30a. Angle θ2 is the angle between the reinforcing cord 30a closest to the midpoint 21c (shown in Figure 5) in the longitudinal direction of antenna 21b and the coil center axis K1.

[0044] Although several embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above and can be implemented in various modified forms. [Examples]

[0045] A passenger car tire (Tire A) with the basic structure shown in Figure 1 and a size of 285 / 65R17 116H, and a passenger car tire (Tire B) with the basic structure shown in Figure 3 and a size of 225 / 30ZR20 85Y XL were prototyped based on the specifications in Table 1. Each test tire includes the electronic module shown in Figure 2. Communication performance and durability tests were then conducted for each test tire. The common specifications and test methods for the tires are as follows. Tire A Rim: 17×8.5J Tire pressure: 250kPa Ha: 40mm Tire B Rim: 20×8.0J Tire pressure: 290kPa Ha: 15mm

[0046] <Communication performance> Communication performance was assessed in accordance with ISO 20912:2020 Conformity Test Method for RFID-Compatible Tires. RFID tags within each test tire were read using an RFID reader and an antenna for the RFID reader, and the reading signal strength (RSSI: amplitude of radio wave signal) was expressed as an index with a standard reading signal strength of 100. A higher test result indicates stronger radio waves and superior communication performance. Specifically, a test result of "30" or higher indicates sufficient communication and is considered a pass. A test result of less than "30" indicates insufficient communication and is considered a fail. RFID reader: IMPINJ Corporation (Model: SPEEDWAY R420) Antenna for RFID reader: Manufactured by Maspro Denkoh Co., Ltd. (Model number: RAF2031)

[0047] <Durability> Each test tire was run on a drum test machine according to the specifications below. Afterward, each test tire was disassembled, and the extent of damage to the carcass cords around the electronic components, as well as the extent of damage to the electronic components themselves, was examined. The extent of damage was evaluated on a three-point scale from A to C as described below. A: The damage is either absent or minor, and continued use will not adversely affect the tire's lifespan or the operation of the electronic components. B: The damage is greater than A, but there are no practical problems with the tires and electronic components. C: This is a more severe injury than B, and improvement is desired. Tire A Vertical load: 14.35kN Tire B Vertical load: 6.14kN Speed: 120 km / h (common to both tires A and B) Mileage: 20,000 km (common to tires A and B) Comparative Examples 1 and 2 mean that the electronic components are located outside region A2, while Comparative Example 3 and Examples 1-3 mean that the electronic components are located inside region A2. Furthermore, Comparative Examples 4 and 5 mean that the electronic components are located outside region A1, while Examples 4-6 mean that the electronic components are located inside region A1. The test results are shown in Table 1.

[0048] [Table 1]

[0049] As shown in Table 1, the tire of the embodiment exhibits superior durability of the tire (carcass cord) and electronic components compared to the tire of the comparative example. Furthermore, the tire of the embodiment also exhibits superior communication performance.

[0050] [Note] The present invention includes the following embodiments.

[0051] [Invention 1] It is a pneumatic tire, A pair of bead sections, Including at least one electronic component, The aforementioned electronic component has an electrical resistivity of 1.0 × 10⁻⁶ 10 It is covered with a rubber cover of Ω·cm or larger. Each of the pair of bead portions is provided with a bead core and a bead apex rubber extending outward in the tire radial direction from the outer surface of the bead core in the tire radial direction. If the height of the bead apex rubber from the outer surface of the bead core in the tire radial direction is less than 25 mm, the electronic component is arranged in a region of 5 mm or more and 25 mm or less outward from the outer surface of the bead core in the tire radial direction. If the height of the bead apex rubber is 25 mm or more, the electronic component is positioned in an area that extends 5 mm or more outward in the tire radial direction from the outer surface of the bead core, and below the outer edge of the bead apex rubber in the tire radial direction. Pneumatic tires. [Invention 2] The pneumatic tire according to the present invention 1, wherein the electronic component is located in a low-strain region within the region where the sum of strains is 60% or less of the maximum value of the sum of strains. [Invention 3] A toroidal carcass extending between the bead cores of the pair of bead portions, The carcass further includes a toroidal inner liner layer extending between the pair of bead portions inside the carcass, The aforementioned electronic component is disposed between the carcass and the inner liner layer in the pneumatic tire according to invention 1 or 2. [4th Invention] The inner liner layer contains 80% by mass or more of butyl rubber, as described in any one of claims 1 to 3 of the present invention. [5th ​​Invention] The aforementioned electronic component includes a main body equipped with an IC chip and an antenna extending in a coil shape. The pneumatic tire according to any one of claims 1 to 4 of the present invention, wherein the antenna and the main body are not directly connected, and the main body is located in the internal space of the coil of the antenna. [Invention 6] The pneumatic tire according to the present invention, wherein, when viewed from the direction of the tire rotation axis, the electronic components are arranged such that the coil central axis of the antenna is at an angle of 45 degrees or less with respect to the tire circumferential direction. [Explanation of symbols]

[0052] 1. Pneumatic tire 4. Bead section 5 Bead core 5a Exterior 8 Bead Apex Rubber 8e outer edge Ha Bead Apex Rubber Height A2 area 21 Electronic Components

Claims

1. It is a pneumatic tire, A pair of bead sections, Including at least one electronic component, The aforementioned electronic component has an electrical resistivity of 1.0 × 10 １０ It is covered with a rubber cover of Ω·cm or larger. Each of the pair of bead portions is provided with a bead core and a bead apex rubber extending outward in the tire radial direction from the outer surface of the bead core in the tire radial direction. If the height of the bead apex rubber from the outer surface of the bead core in the tire radial direction is less than 25 mm, the electronic component is arranged in a region of 5 mm or more and 25 mm or less outward from the outer surface of the bead core in the tire radial direction. If the height of the bead apex rubber is 25 mm or more, the electronic component is positioned in an area that extends 5 mm or more outward in the tire radial direction from the outer surface of the bead core, and below the outer edge of the bead apex rubber in the tire radial direction. Pneumatic tires.

2. The pneumatic tire according to claim 1, wherein the electronic component is located in a low-strain region within the region where the sum of strains is 60% or less of the maximum value of the sum of strains.

3. A toroidal carcass extending between the bead cores of the pair of bead portions, The carcass further includes a toroidal inner liner layer extending between the pair of bead portions inside the carcass, The pneumatic tire according to claim 1 or 2, wherein the electronic component is disposed between the carcass and the inner liner layer.

4. The pneumatic tire according to claim 3, wherein the inner liner layer contains 80% by mass or more of butyl rubber.

5. The aforementioned electronic component includes a main body equipped with an IC chip and an antenna extending in a coil shape. The pneumatic tire according to claim 1 or 2, wherein the antenna and the main body are not directly connected, and the main body is located in the internal space of the coil of the antenna.

6. The pneumatic tire according to claim 5, wherein, when viewed from the direction of the tire rotation axis, the electronic components are arranged such that the central axis of the antenna coil is at an angle of 45 degrees or less with respect to the circumferential direction of the tire.

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