| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic radial tire capable of improving high-speed durability and road noise without degrading load durability. SOLUTION: In the pneumatic radial tire, a carcass layer 4 is formed between a pair of beads 3, 3 and at least two belt layers 6 are arranged on the outer-periphery side of the carcass layer 4 in a tread portion 1. In addition, a belt reinforcing layer 7 including one or a plurality of organic fiber cords circulating in the peripheral direction of a tire is disposed as a reinforcing cord on the outer periphery side of the belt layer 6 to cover both ends of at least the belt layer 6. A coefficient of elasticity of the reinforcing cord of the belt reinforcing layer 7 is not less than 5,000 MPa and less than 10,000 MPa when the reinforcing cord elongates by 2%, and residual tension per reinforcing cord of the belt reinforcing layer 7 is set to be not less than 10 N and less than 40 N. COPYRIGHT: (C)2011,JPO&INPIT |
