pneumatic tires

Abstract

In pneumatic tires equipped with carcass cords whose stretch direction changes, the reduction in wear resistance is suppressed. [Solution] The system comprises a carcass, a reinforcing layer, and a cap tread, the reinforcing layer including belt plies and band plies, the angle at which the extension direction of the carcass cords is inclined from the tire circumferential direction at the position of the tire centerline is A1 (°), the angle at which it is inclined from the tire circumferential direction at the position of the tire's maximum width is A2 (°), the shortest distance between the carcass cords and belt cords is Da (mm), the shortest distance between the belt cords and band cords is Db (mm), and the complex modulus of elasticity of the cap tread at 30°C is 30°E * A pneumatic tire that satisfies the following equation, where c is (MPa) and K is a constant. |A2-A1|>0; Db / Da>0.50; and 30℃E * c > K / {|A2 - A1| × (Db - 0.5 × Da)} (where K is 2.8)

Claims

1. A pneumatic tire comprising a carcass, a reinforcing layer positioned radially outward of the carcass, and a cap tread positioned radially outward of the reinforcing layer, The aforementioned cap tread is made of a rubber composition containing rubber components, The reinforcing layer includes belt plies and band plies, The carcass is composed of at least one carcass ply, The belt ply, the band ply, and the carcass ply each include a belt cord, a band cord, and a carcass cord, respectively. Of the carcass plies, the angle at which the extension direction of the carcass cord of at least one of the carcass plies is inclined from the tire circumferential direction at the position of the tire centerline is A 1 (°), A is the angle of inclination from the tire circumferential direction at the position of the tire's widest width. 2 (°), Da (mm) is the shortest distance between the cord surfaces of the carcass cord and the belt cord at the tire centerline, Db (mm) is the shortest distance between the cord surfaces of the belt cord and the band cord at the tire centerline, and the complex modulus of elasticity of the rubber composition constituting the cap tread at 30°C is 30°CE * When c (MPa) is a constant and K is the case, A 1 A 2 , Da, Db, 30℃E * A pneumatic tire in which c and K satisfy the following equations (1), (2), and (3). (1)|A 2 -A 1 |>0 (2) Db / Da>0.50 (3)30℃E * c>K / {|A 2 -A 1 |×(Db-0.5×Da)} (However, K is 2.8)

2. The pneumatic tire according to claim 1, wherein the constant K in formula (2) is 4.

0.

3. The pneumatic tire according to claim 1 or 2, wherein the rubber component constituting the cap tread includes isoprene-based rubber.

4. The pneumatic tire according to claim 1 or 2, wherein the rubber component constituting the cap tread contains styrene-butadiene rubber with a styrene content of 30% by mass or less.

5. The pneumatic tire according to claim 1 or 2, wherein the rubber composition constituting the cap tread includes a resin.

6. A R1 , A R2 The pneumatic tire according to claim 1 or 2, wherein Da and Db satisfy the following formula (4). (4)(Db-0.5×Da) / |A 2 -A 1 |>0.001

7. The pneumatic tire according to claim 1 or 2, wherein at least one of the band cords is an organic fiber cord containing filaments made of polyester fibers.

8. In at least one of the belt plies and band plies, the angle A in which the extension direction of the cords in the ply is inclined from the tire circumferential direction. RF (°) is the above A I A pneumatic tire according to claim 1 or 2, which is different from (°).

9. A RF The inclination direction from the tire circumferential direction is the A 1 The pneumatic tire according to claim 8, wherein the direction of inclination is opposite to the direction of inclination from the circumferential direction of the tire.

10. The pneumatic tire according to claim 1 or 2, wherein the carcass is composed of a single carcass ply.

11. The pneumatic tire according to claim 1 or 2, wherein the reinforcing layer is composed of one belt ply and one band ply.

12. A 2 A pneumatic tire according to claim 1 or 2, wherein the angle is +70° or more and +90° or less, or -70° or less and greater than -90°.

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