Passenger vehicle tire

Abstract

In the passenger vehicle tire, the tread rubber (T07) is composed of crown rubber (T07C) and base rubber (T07B), the crown rubber is located on the outer side in the tire radial direction relative to the base rubber and located on the two outer sides in the tire width direction relative to the base rubber, and the whole base rubber is composed of rubber with the same components. The width of the base rubber in the tire width direction is shorter than the width of the crown rubber in the tire width direction, and the storage modulus E'of the base rubber is 2.0 times or more of the storage modulus E 'of the crown rubber.

Description

Technical Field

[0001] The present disclosure relates to a passenger vehicle tire.

[0002] This application claims the benefit of Japanese Patent Application No. 2023-011339, filed in Japan on January 27, 2023, the entire contents of which are incorporated herein by reference. Background Art

[0003] Conventionally, there are passenger car tires in which tread rubber is composed of cap rubber and base rubber (for example, Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-159893 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, in conventional passenger car tires, there is room for improvement in wear resistance.

[0009] The present disclosure aims to provide a passenger vehicle tire capable of improving wear resistance.

[0010] Solutions for solving problems

[0011] [1] A passenger car tire comprising:

[0012] The tread rubber consists of cap rubber and base rubber.

[0013] The cap rubber is located on the outer side of the base rubber in the tire radial direction, and is also located on both outer sides of the base rubber in the tire width direction.

[0014] The base rubber is composed of rubber with the same composition as the whole.

[0015] The width of the base rubber in the tire width direction is shorter than the width of the cap rubber in the tire width direction, and

[0016] The storage modulus E' of the base rubber is at least 2.0 times the storage modulus E' of the cap rubber.

[0017] Effects of the Invention

[0018] According to the present disclosure, a passenger vehicle tire capable of improving wear resistance can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] [ Figure 1 ] Figure 1Schematic diagram for explaining the configuration of tread rubber of a passenger car tire according to one embodiment of the present disclosure.

[0020] [ Figure 2 ] Figure 2 1 is a diagram for explaining an example of an internal tire structure applicable to a passenger vehicle tire according to an optional embodiment of the present disclosure, and is a schematic tire widthwise cross-sectional view showing half of the tire in cross section in the tire width direction.

[0021] [ Figure 3 ] Figure 3 It is a graph used to illustrate the analysis results.

[0022] [ Figure 4 ] Figure 4 is a schematic diagram showing the configuration of the tread rubber of a passenger car tire according to Comparative Example 1. DETAILED DESCRIPTION

[0023] The passenger vehicle tire according to the present disclosure may be applicable to any passenger vehicle pneumatic tire.

[0024] Hereinafter, embodiments of a passenger vehicle tire according to the present disclosure will be illustratively described with reference to the accompanying drawings.

[0025] In this specification, a passenger car tire is also simply referred to as a "tire."

[0026] In the drawings, the same reference numerals are given to common components and parts.

[0027] Figure 1 1 is a schematic diagram for explaining the configuration of a tread rubber T07 of a passenger car tire T01 according to one embodiment of the present disclosure. Figure 2 1 is a diagram for illustrating an example of an internal tire structure that can be applied to a tire T01 according to any embodiment of the present disclosure, and is a schematic tire width direction cross-sectional view showing a tire half (a portion on one side relative to the tire equatorial plane CL) of the tire T01 through a section in the tire width direction.

[0028] Figure 1 The tire T01 of the embodiment in FIG. 1 is configured as a passenger car tire (more specifically, a passenger car pneumatic tire).

[0029] like Figure 2 As shown, the tire T01 according to each embodiment of the present disclosure includes a tread portion T01t, a pair of sidewall portions T01w extending radially inward from both ends of the tread portion T01t in the tire width direction, and a pair of bead portions T01b provided at the radially inner ends of the respective sidewall portions T01w. The bead portions T01b are configured to contact the rim at the radially inner side and the widthwise outer side of the tire when the tire T01 is mounted on the rim.

[0030] In the tread portion T01t, the tread rubber T07 is located radially outside the belt T06. The tread rubber T07 constitutes the tread surface 8, which is the radially outer surface of the tread portion T01t. A tread pattern is formed on the tread surface 8. Any tread pattern can be provided on the tread surface 8.

[0031] In this specification, the "tread surface (8)" refers to the outer peripheral surface of the tire that contacts the road surface over the entire circumference when the tire is assembled on an applicable rim and filled with a standard internal pressure and rolled under a maximum load.

[0032] In this specification, the "ground contact end (E)" refers to the end of the tread surface (8) in the tire width direction.

[0033] In this specification, "ground contact width (TW)" refers to the distance in the tire width direction between a pair of ground contact ends (E) of the tread surface (8).

[0034] Here, "applicable rim" refers to a standard rim of an applicable size that has been recorded or will be recorded in the future in the industry standards effective in the area where the tire is produced and used, such as the JATMA Yearbook of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan, the standard manual of the European Tire and Rim Technical Organization (ETRTO) in Europe, and the yearbook of the Tire and Rim Association (TRA) in the United States (that is, the above "applicable rim" also includes, in addition to the current sizes, sizes that will be recorded in the future in the aforementioned industry standards. An example of "sizes to be recorded in the future" can be the sizes listed as "FUTURE DEVELOPMENTS" in the 2013 edition of the ETRTO standard manual). In the case of a size not recorded in the above-mentioned industry standards, the "applicable rim" is a rim having a width corresponding to the bead width of the tire.

[0035] In addition, "standard internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity under the applicable size and ply grade recorded in the aforementioned JATMA Yearbook and other industry standards, and in the case of sizes not listed in the aforementioned industry standards, "standard internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is installed.

[0036] "Maximum load" refers to the load corresponding to the above-mentioned maximum load capacity.

[0037] Note that the air mentioned here may be replaced with an inert gas such as nitrogen.

[0038] In this specification, unless otherwise specified, the dimensions of various elements (such as grooves and land portions) are measured with the tire assembled to the applicable rim, inflated to the standard internal pressure, and unloaded. Here, the dimensions of various elements on the tread surface, such as grooves and land portions, are measured in a developed view of the tread surface. In this specification, "developed view of the tread surface" refers to a plan view of the tread surface with the tread surface deployed on a plane.

[0039] In the following, reference will be made to Figure 1 The structure of the tread rubber T07 in the tire T01 of this embodiment will be described. Figure 1 , illustration of components other than the tread rubber T07 in the internal structure of the tire T01 is omitted.

[0040] like Figure 1 As shown, in this embodiment, the tread rubber T07 is composed of a cap rubber T07C and a base rubber T07B. The cap rubber T07C is located radially outward from the base rubber T07B and also on both sides of the width direction outside the base rubber T07B. The cap rubber T07C extends across the entire tire widthwise region between the pair of contact points E. The base rubber T07B is located on the tire equatorial plane CL. On the tire equatorial plane CL, the cap rubber T07C is located radially outward from the base rubber T07B. On both sides of the width direction outside the base rubber T07B, the tread rubber T07 consists solely of the cap rubber T07C.

[0041] The base rubber T07B is entirely composed of rubber having the same composition throughout.

[0042] Preferably, the cap rubber T07C is also entirely composed of rubber having the same composition throughout.

[0043] The base rubber T07B may be composed of a single rubber member as in the example in the drawings. As in the example in the drawings, the cap rubber T07C may also be composed of a single rubber member.

[0044] The width WB of the base rubber T07B in the tire width direction is shorter than the width WC of the cap rubber T07C in the tire width direction.

[0045] The storage modulus E' of the base rubber T07B is at least 2.0 times the storage modulus E' of the cap rubber T07C.

[0046] In this specification, the “storage modulus (E′)” is measured using a viscoelastic meter at room temperature 25° C., a frequency of 52 Hz, an initial strain rate of 2%, and a dynamic strain rate of 2%.

[0047] The value of the storage modulus E' can be increased, for example, by increasing the carbon black content in the rubber.

[0048] Here, the effects of the tire T01 of the present embodiment will be described.

[0049] Typically, in passenger car tires, the tire axial force distribution in actual vehicles is primarily composed of a large free-rolling component. Therefore, reducing the wear energy during free-rolling is effective for improving wear resistance. Due to the tire's structure, the outer surface typically has curvature in the tire's widthwise cross-section, resulting in differences in the turning radius depending on the tire's widthwise position. Consequently, braking forces are primarily applied to the shoulder side (outer widthwise portion), and slippage on the road surface occurs during traction starts, potentially generating wear energy.

[0050] Therefore, in this embodiment, as described above, the cap rubber T07C is located radially outward from the base rubber T07B and also on both widthwise outward sides of the base rubber T07B. The base rubber T07B is entirely composed of a rubber having the same composition throughout. The width WB of the base rubber T07B is shorter than the width WC of the cap rubber T07C. Furthermore, the storage modulus E' of the base rubber T07B is at least 2.0 times that of the cap rubber T07C. In other words, roughly speaking, the relatively hard base rubber T07B is located only in the center (inner) portion of the tire.

[0051] As a result, during a traction start, a braking force component is applied to the center section, while a driving force component is applied to the shoulder sections, thereby offsetting the wear energy of each section during free rolling. By making the storage modulus E' of the base rubber T07B relatively high, the shear deformation of the base rubber T07B during a traction start is reduced, while the overall deformation of the tread rubber T07 remains approximately constant, thereby increasing the shear deformation of the cap rubber T07C. The shear force generated by the relative displacement between the belt T06 and the tread rubber T07 on the traction side is directed in the braking direction. By making the base rubber T07B harder, the shear deformation of the cap rubber T07C becomes even greater, thereby increasing the braking force component in the center section. This braking force offsets the driving force generated during a traction start, thereby reducing the wear energy during free rolling. Furthermore, by suppressing the shear deformation of the base rubber T07B, the actual rotation radius becomes smaller, thereby reducing the difference in rotation radius between the shoulder and center sections and suppressing braking in the shoulder sections during a traction start. Therefore, the wear energy in the shoulder side portion can also be offset.

[0052] In this way, the wear resistance can be improved.

[0053] Preferably, the storage modulus E' of the base rubber T07B is not more than 2.5 times the storage modulus E' of the cap rubber T07C. That is, preferably, the storage modulus E' of the base rubber T07B is 2.0 to 2.5 times the storage modulus E' of the cap rubber T07C.

[0054] This makes it possible to further improve the wear resistance.

[0055] It is preferable that the tire width direction width WB of the base rubber T07B is at least 40% of the ground contact width TW, and more preferably at least 50% of the ground contact width TW. This makes it possible to further improve the wear resistance.

[0056] It is preferable that the tire width direction width WB of the base rubber T07B is not more than 70% of the ground contact width TW, and more preferably not more than 60% of the ground contact width TW. This makes it possible to further improve the wear resistance.

[0057] It is preferable that the tire width direction width WC of the cap rubber T07C is at least 100% of the ground contact width TW.

[0058] As in Figure 1 In the example shown, the tread surface 8 may be provided with a plurality of ( Figure 1 In the example of three) main slots 3 and one or more (in Figure 1 In the example of two) central land portions 6. Each main groove 3 extends in the tire circumferential direction. One or more (in Figure 1 The central land portion 6 is divided into a plurality of (two in the example) Figure 1 In the example of three) main slots 3. Figure 1 In the example of three main grooves 3, a pair of shoulder land portions 5 are separated between a pair of main grooves 3 located at the outermost positions in the tire width direction and a pair of ground contact edges E.

[0059] In the tire widthwise region corresponding to each central land portion 6 located within the tire widthwise region corresponding to the base rubber T07B, it is preferred that the average value of the ratio of the thickness GB of the base rubber T07B to the thickness GT of the tread rubber T07 be at least 20%, and more preferably at least 30%. This makes it possible to further improve wear resistance.

[0060] In the tire widthwise region corresponding to each central land portion 6 located within the tire widthwise region corresponding to the base rubber T07B, it is preferred that the average value of the ratio of the thickness GB of the base rubber T07B to the thickness GT of the tread rubber T07 be no greater than 50%, and more preferably no greater than 40%. This makes it possible to further improve wear resistance.

[0061] exist Figure 1In the example of , the base rubber T07B extends over all of the central land portions 6 ; in other words, in the tire widthwise region corresponding to the base rubber T07B, the entire tire widthwise region of each of the central land portions 6 is located.

[0062] exist Figure 1 In the example, the base rubber T07B is not located in the pair of shoulder land portions 5 ; in other words, the tire width direction region corresponding to the base rubber T07B is located only widthwise inside relative to the tire width direction region of each of the pair of shoulder land portions 5 .

[0063] However, these configurations are not required.

[0064] As in Figure 1 In the example of , it is preferable that the center of the base rubber T07B in the tire width direction is located on the tire equatorial plane CL.

[0065] In the examples described in this specification, the tire T01 may have any internal structure other than the tread rubber T07 described above. Figure 2 , an example of the internal structure of the tire T01 excluding the tread rubber T07 will be described.

[0066] exist Figure 2 In the example shown, the tire T01 includes a pair of bead cores T02 , a pair of bead fillers T03 , a carcass T05 , a belt T06 , a tread rubber T07 , a sidewall rubber T08 , and an inner liner T09 .

[0067] Each bead core T02 is embedded in the corresponding bead portion T01b. The bead core T02 comprises a plurality of rubber-covered bead wires. The bead wires can be made of metal (e.g., steel) or organic fibers such as polyester, nylon, rayon, or aramid. The bead wires can be formed, for example, from monofilament or stranded wire.

[0068] Each bead filler T03 is located radially outward relative to the corresponding bead core T02. The bead filler T03 extends radially outward of the tire in a tapered shape. The bead filler T03 is made of rubber.

[0069] The carcass T05 extends between a pair of bead cores T02 and extends in a toroidal shape. Figure 1 In the example of FIG, the carcass ply T05p is composed of one or more carcass cords and a coating rubber covering the carcass cords. The carcass cords can be formed of monofilaments or twisted wires.

[0070] The carcass cords may be made of metal (eg, steel), or may be made of organic fibers such as polyester, nylon, rayon, or aramid.

[0071] The carcass T05 preferably has a radial structure, but may also have a bias structure.

[0072] The belt T06 is arranged on the radially outer side of the crown portion of the carcass T05. The belt T06 includes one or more ( Figure 1 In the example, there are two belt plies T06p. Each belt ply T06p includes one or more belt cords and a coating rubber covering the belt cords. The belt cords may be formed from monofilaments or twisted wires. The belt cords may be made of metal (e.g., steel) or organic fibers such as polyester, nylon, rayon, or aramid.

[0073] The sidewall rubber T08 is located on the sidewall portion T01w. It forms the outer surface of the sidewall portion T01w in the width direction. It is located widthwise outward relative to the carcass T05. It is located widthwise outward relative to the bead filler T03. The sidewall rubber T08 is integrally formed with the tread rubber T07.

[0074] The inner liner T09 is arranged inside the carcass T05 and can be, for example, laminated thereto. The inner liner T09 is composed, for example, of a butyl-based rubber having low air permeability. Butyl-based rubbers include, for example, butyl rubber and halogenated butyl rubber, a derivative of butyl rubber. The inner liner T09 is not limited to butyl-based rubber and can be composed of other rubber compositions, resins, or elastomers.

[0075] Although not shown, the tire T01 may or may not include a cushion rubber between the carcass T05 and the tread rubber T07 in the tire radial direction. The cushion rubber may be located near the widthwise ends of the belt T06.

[0076] like Figure 2 As shown, the tire T01 may include a rubber chafer T11 in a portion of each bead portion T01b configured to contact the rim.

[0077] like Figure 2 As shown, the tire T01 may include one or more (in Figure 2 In the example of a) wire bead packing cloth T14. Figure 2 In the example of , the wire chafer T14 may be arranged on the opposite side of the bead core T02 relative to the carcass T05. The wire chafer T14 is made of metal (eg, steel).

[0078] Although not shown, the tire T01 may include one or more nylon chafers surrounding each bead core T02. Figure 1In the example of , the nylon chafer may be arranged on the opposite side of the bead core T02 relative to the carcass T05. The nylon chafer is made of nylon.

[0079] Although not shown, the tire T01 may include a hat rubber between the bead filler T03 and the sidewall rubber T08 in the tire width direction in each tire half.

[0080] like Figure 2 As shown, the tire T01 can be provided with an RF tag 10 as a communication device. The RF tag 10 includes an IC chip and an antenna. The RF tag 10 can be arranged, for example, to be sandwiched between a plurality of members of the same or different types constituting the tire T01. By doing so, it is easier to attach the RF tag 10 during the production of the tire T01, thereby improving the productivity of the tire T01 equipped with the RF tag 10. Figure 2 In the example of , the RF tag 10 may be arranged to be sandwiched between the bead filler T03 and another member adjacent to the bead filler T03 , for example.

[0081] The RF tag 10 can also be embedded within any component of the tire T01. This reduces the load applied to the RF tag 10 compared to when it is sandwiched between multiple components of the tire T01. Consequently, the durability of the RF tag 10 can be improved. In this example, the RF tag 10 can be embedded within a rubber component such as the tread rubber T07 or the sidewall rubber T08.

[0082] It is preferable that the RF tag 10 is not arranged at a position that serves as a boundary between components having different rigidities in the circumferential direction, which is a direction along the outer surface of the tire in a cross-sectional view in the tire width direction. By doing so, the RF tag 10 is not arranged at a position where strain may be concentrated due to a rigidity step difference. Therefore, the load applied to the RF tag 10 can be reduced. Therefore, the durability of the RF tag 10 can be improved. In this example, it is preferable that the RF tag 10 is not arranged at a position that serves as a boundary between the end of the carcass T05 and a component adjacent to the end of the carcass T05 (such as the sidewall rubber T08) in a cross-sectional view in the tire width direction.

[0083] The number of RF tags 10 is not particularly limited. The tire T01 may be provided with only one RF tag 10, or may be provided with two or more RF tags 10. Here, the RF tag 10 is described as an example of a communication device, but a communication device different from the RF tag 10 may also be used.

[0084] The RF tag 10 may be arranged, for example, in the tread portion T01t of the tire T01. By doing so, the RF tag 10 is not damaged by the side cut of the tire T01.

[0085] The RF tag 10 can be placed, for example, in the center of the tread in the tire width direction. This is the location in the tread portion T01t where buckling is less likely to be concentrated. This reduces the load applied to the RF tag 10, thereby improving the durability of the RF tag 10. Furthermore, it can suppress the occurrence of differences in communication with the RF tag 10 from the two outer sides of the tire T01 in the tire width direction. In this example, the RF tag 10 can be placed, for example, within a range of 1 / 2 the tread width in the tire width direction, centered on the tire equatorial plane CL.

[0086] The RF tag 10 can be placed, for example, at a tread end in the tire width direction. If the position of a reader with which the RF tag 10 communicates is predetermined, the RF tag 10 can be placed, for example, at a tread end closer to the reader. In this example, the RF tag 10 can be placed within a range of ¼ of the tread width, with the tread end being the outer end in the tire width direction.

[0087] The RF tag 10 can be arranged, for example, on the inner cavity side of the tire relative to the carcass T05, which includes one or more carcass plies T05p spanning between the bead portions T01b. By doing so, the RF tag 10 becomes less susceptible to damage from external impacts, side cuts, or nail punctures. As an example, the RF tag 10 can be arranged in close contact with the surface of the carcass T05 on the inner cavity side of the tire (see Figure 2 As another example, when there is another member on the tire inner cavity side relative to the carcass T05, the RF tag 10 can be arranged, for example, between the carcass T05 and the other member located on the tire inner cavity side relative to the carcass T05. As an example of another member located on the tire inner cavity side relative to the carcass T05, the inner liner T09 forming the inner surface of the tire can be mentioned. As another example, the RF tag 10 can be attached to the inner surface of the tire facing the tire inner cavity (see Figure 2 (see point P32 in the figure). By configuring the RF tag 10 to be attached to the inner surface of the tire, attachment of the RF tag 10 to the tire T01 and inspection or replacement of the RF tag 10 can be easily performed. In other words, the attachability and maintainability of the RF tag 10 can be improved. Furthermore, by attaching the RF tag 10 to the inner surface of the tire, the RF tag 10 can be prevented from becoming a source of tire failure, compared to a configuration in which the RF tag 10 is embedded within the tire T01.

[0088] In addition, when the carcass T05 is provided with a plurality of carcass plies T05p and there is a position where the plurality of carcass plies T05p are stacked, the RF tag 10 may be arranged between the stacked carcass plies T05p.

[0089] The RF tag 10 may be arranged, for example, on the outer side in the tire radial direction relative to the belt T06 including one or more belt plies T06p in the tread portion T01t of the tire T01. As an example, the RF tag 10 may be arranged on the outer side in the tire radial direction relative to the belt T06 so as to be in close contact with the belt T06 (see FIG. Figure 2 As another example, when a belt reinforcement layer T04 is provided, the RF tag 10 may be arranged outside the belt reinforcement layer T04 in the tire radial direction so as to be in close contact with the belt reinforcement layer T04 (see Figure 2 As another example, the RF tag 10 may be embedded in the tread rubber T07 on the outside in the tire radial direction relative to the belt T06 (see Figure 2 By arranging the RF tag 10 on the outside in the tire radial direction relative to the belt T06 in the tread portion T01t of the tire T01, communication with the RF tag 10 from the outside of the tire T01 in the tire radial direction is less likely to be blocked by the belt T06. Therefore, communication with the RF tag 10 from the outside of the tire T01 in the tire radial direction can be improved.

[0090] Furthermore, the RF tag 10 can be arranged, for example, on the inner side of the belt T06 in the tread portion T01t of the tire T01 in the radial direction of the tire. By doing so, the outer side of the RF tag 10 in the radial direction of the tire is covered by the belt T06, so that the RF tag 10 becomes less susceptible to damage caused by impact or nail puncture from the tread surface. As an example, the RF tag 10 can be arranged between the belt T06 in the tread portion T01t of the tire T01 and the carcass T05 located on the inner side of the belt T06 in the radial direction of the tire (see Figure 2 Point P42 in the figure).

[0091] Furthermore, when the belt T06 is provided with a plurality of belt plies T06p, the RF tag 10 may be arranged between any two belt plies T06p of the tread portion T01t of the tire T01 (see Figure 2 By doing so, the RF tag 10 is covered on the outside in the tire radial direction by the one or more belt plies T06p, and thus the RF tag 10 becomes less susceptible to damage caused by impact or nail puncture from the tread surface.

[0092] The RF tag 10 may be placed, for example, on the sidewall portion T01w or the bead portion T01b of the tire T01. The RF tag 10 may be placed, for example, on the sidewall portion T01w or the bead portion T01b closer to a reader capable of communicating with the RF tag 10 (see Figure 2By doing so, the communication between the RF tag 10 and the reader can be enhanced. As an example, the RF tag 10 can be arranged between the carcass T05 and the sidewall rubber T08, or between the tread rubber T07 and the sidewall rubber T08 (see Figure 2 Point P61 in the figure).

[0093] The RF tag 10 can be placed, for example, between the tire's maximum width and the tread surface in the tire radial direction. This arrangement enhances communication with the RF tag 10 from the outside of the tire T01 in the tire radial direction, compared to a configuration in which the RF tag 10 is placed radially inward of the tire's maximum width.

[0094] The RF tag 10 can be arranged, for example, on the inner side of the tire radial direction at the position of the maximum width of the tire. By doing so, the RF tag 10 is arranged near the bead portion T01b having high rigidity. Therefore, the load applied to the RF tag 10 can be reduced. Therefore, the durability of the RF tag 10 can be improved. As an example, the RF tag 10 can be arranged at a position adjacent to the bead core T02 in the tire radial direction or the tire width direction. The area around the bead core T02 is an area where strain is less likely to concentrate. Therefore, the load applied to the RF tag 10 can be reduced. Therefore, the durability of the RF tag 10 can be improved.

[0095] In particular, it is preferable to place the RF tag 10 radially inward of the tire's maximum width and radially outward of the bead core T02 of the bead portion T01b. This improves the durability of the RF tag 10 and makes communication between the RF tag 10 and a reader less likely to be blocked by the bead core T02, thereby enhancing the communication performance of the RF tag 10.

[0096] Furthermore, when the sidewall rubber T08 is constituted by a plurality of rubber members of the same or different types adjacent in the tire radial direction, the RF tag 10 may be arranged to be sandwiched between the plurality of rubber members constituting the sidewall rubber T08 .

[0097] The RF tag 10 can be placed so as to be sandwiched between the bead filler T03 and another member adjacent to the bead filler T03. This allows the RF tag 10 to be placed in a location where strain is less likely to concentrate due to the configuration of the bead filler T03. Consequently, the load applied to the RF tag 10 can be reduced, thereby improving the durability of the RF tag 10.

[0098] The RF tag 10 can, for example, be positioned so as to be sandwiched between the bead filler T03 and the carcass T05. The portion of the carcass T05 that, together with the bead filler T03, holds the RF tag 10 can be positioned outward or inward relative to the bead filler T03 in the tire width direction. When the portion of the carcass T05 that, together with the bead filler T03, holds the RF tag 10 outward relative to the bead filler T03 in the tire width direction, the load applied to the RF tag 10 due to damage or impact from outside the tire T01 in the tire width direction can be further reduced. Consequently, the durability of the RF tag 10 can be further improved.

[0099] Furthermore, the bead filler T03 may include a portion disposed adjacent to the sidewall rubber T08. In this case, the RF tag 10 may be disposed so as to be sandwiched between the bead filler T03 and the sidewall rubber T08.

[0100] In addition, the bead filler T03 may include a portion disposed adjacent to the rubber chafer T11. In this case, the RF tag 10 may be disposed so as to be sandwiched between the bead filler T03 and the rubber chafer T11.

[0101] The RF tag 10 may be arranged, for example, to be sandwiched between the rubber chafer T11 and the sidewall rubber T08 (see FIG. Figure 2 By doing so, the RF tag 10 can be placed at a location where strain is less likely to concentrate due to the configuration of the rubber chafer T11. Therefore, the load applied to the RF tag 10 can be reduced. Therefore, the durability of the RF tag 10 can be improved.

[0102] The RF tag 10 may be arranged, for example, to be sandwiched between the rubber chafer T11 and the carcass T05 (see Figure 2 By doing so, the load applied to the RF tag 10 due to damage or impact from the rim can be reduced. Therefore, the durability of the RF tag 10 can be improved.

[0103] The RF tag 10 can be arranged to be sandwiched between the wire chafer T14 and another member adjacent to the wire chafer T14 on the inside or outside in the tire width direction. By doing so, the position of the RF tag 10 becomes less likely to change during tire deformation. Therefore, the load applied to the RF tag 10 during tire deformation can be reduced. Therefore, the durability of the RF tag 10 can be improved. As an example of another member adjacent to the wire chafer T14 on the inside or outside in the tire width direction, a rubber member such as the rubber chafer T11 can be mentioned (see Figure 2In addition, as another member adjacent to the wire chafer T14 on the inner side or the outer side in the tire width direction, the carcass T05 (see Figure 2 point P101 in the figure).

[0104] The belt reinforcement layer T04 may also be provided radially outside the belt T06. For example, the belt reinforcement layer T04 may be formed by continuously spirally winding a belt reinforcement layer cord made of polyethylene terephthalate in the tire circumferential direction. Here, the belt reinforcement layer cord may be formed at least 6.9×10 -2 The belt reinforcement layer T04 can be subjected to adhesive treatment under a tension of 29.4 N / dtex and can have an elastic modulus of at least 2.5 mN / dtex·% measured at 160°C under a load of 29.4 N. Furthermore, the belt reinforcement layer T04 can be arranged to cover the entire belt T06 or only the ends of the belt T06. Furthermore, the winding density per unit width of the belt reinforcement layer T04 can vary depending on the position in the width direction. This can reduce road noise and flat spots on the tread without compromising high-speed durability.

[0105] Example

[0106] As described below, the tires T01 according to the examples and comparative examples were evaluated by FEM analysis.

[0107] Figure 3 The results of an FEM analysis performed using a model of tire T01 are presented. In this analysis, as parameters of the tire T01 model, the ratio of the storage modulus E' of the base rubber T07B to the storage modulus E' of the cap rubber T07C (storage modulus E' of base rubber T07B / storage modulus E' of cap rubber T07C) ( Figure 3 (a) and Figure 3 ) and the ratio (%) of the tire width direction width WB of the base rubber T07B to the ground contact width TW ( Figure 3 (a) and Figure 3 The vertical axis in (b) of ) is varied, and the wear energy index ( Figure 3 (a) and Figure 3 Except for these parameters, the configuration of the tire T01 model is the same in each embodiment. Figure 3 (a) shows the wear energy index generated in each central land portion 6, and Figure 3 (b) shows the wear energy index generated in each shoulder land portion 5. The higher the value of the wear energy index, the better the wear resistance. The model of the tire T01 basically has a tread rubber T07 having a Figure 1 or Figure 4 In the tire T01 model in each embodiment, the three examples of Comparative Example 1, Example 1 and Example 2 (shown by Figure 3 , and are also presented in Table 1. In addition, Table 1 presents the wear energy of each of Comparative Example 1, Example 1, and Example 2 as an index with the wear energy of Comparative Example 1 being set to 100. The higher the value of this wear energy index, the better the wear resistance.

[0108] [Table 1]

[0109]

[0110] From Table 1 and Figure 3 It can be seen that the tires of the examples have a higher wear energy index than the tire of Comparative Example 1, and therefore have higher wear resistance.

[0111] Industrial applicability

[0112] The passenger vehicle tire according to the present disclosure may be applicable to any passenger vehicle pneumatic tire.

[0113] Description of Reference Numerals

[0114] T01: Passenger car tires (tire),

[0115] 3: Main slot,

[0116] 5: shoulder land portion,

[0117] 6: Central Land Department,

[0118] 8: Tread surface,

[0119] E: ground terminal,

[0120] TW: Ground contact width, WC: Cap rubber width in the tire width direction, WB: Base rubber width in the tire width direction,

[0121] GT: thickness of tread rubber, GB: thickness of base rubber,

[0122] T01t: tread, T01w: sidewall, T01b: bead,

[0123] T02: bead core,

[0124] T03: bead filler,

[0125] T04: belt reinforcement layer,

[0126] T05: carcass, T05p: carcass ply,

[0127] T06: belt, T06p: belt ply,

[0128] T07: tread rubber, T07C: cap rubber, T07B: base rubber,

[0129] T08: sidewall rubber,

[0130] T09: Inner liner, T11: Rubber chafer, T14: Wire chafer,

[0131] CL: Tire equatorial plane,

[0132] 10: RF tag

Claims

1. A passenger car tire, comprising: The tread rubber consists of cap rubber and base rubber, The cap rubber is located on the outer side in the tire radial direction relative to the base rubber and is also located on both outer sides in the tire width direction relative to the base rubber. The base rubber is entirely composed of rubber having the same composition. The width of the base rubber in the tire width direction is shorter than the width of the cap rubber in the tire width direction, and The storage modulus E' of the base rubber is at least 2.0 times the storage modulus E' of the cap rubber. 2 . The passenger car tire according to claim 1 , wherein the storage modulus E′ of the base rubber is 2.0 to 2.5 times the storage modulus E′ of the cap rubber. 3 . The passenger vehicle tire according to claim 1 , wherein a width of the base rubber in the tire width direction is 40% to 70% of a ground contact width.

4. The passenger car tire according to claim 1, wherein the tread surface is provided with Multiple main slots, and One or more central land portions separated between the plurality of main grooves, And among them, In a tire widthwise region corresponding to each of the central land portions located within a tire widthwise region corresponding to the base rubber, an average value of a ratio of a thickness of the base rubber to a thickness of the tread rubber is at least 20%.

Images