| 摘要 |
PURPOSE:To reduce weight of a tire by providing a carcass of a specified constitution, an inner reinforcement layer, and an intermediate layer comprising two plies, to suppress lowering of bead rigidity and steering stability. CONSTITUTION:A carcass 6 is formed with inner and outer plies 6a and 6b in which cords are arranged in parallel with each other at a slant angle of 75 deg. to 90 deg. relative to the circumferential direction of a tire. Also the carcass raised height Hca of the raised portion 6Ba of the outer ply 6a is set to not less than 1/2 the tire cross section height Ht. In addition, an adjacent portion Y is formed in the main body 6A of the carcass 6 and a raised portion 6B through an intermediate reinforcement layer 9. On the other hand, an inner reinforcement layer 8 is formed with plies using high tensile steel, and their cords are inclined at an angle of 15 deg. to 50 deg. relative to circumferential direction of the tire. Then the cords of plies 9A and 9B for the intermediate reinforcement layer 9 are inclined at an angle of 30 deg. to 60 deg. relative to the radial direction of the tire, and a distance d1 of the cords between the plies 9a and 9B is set to more than the diameter of the cord and below two times the diameter of it. |
