| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve run-flat durability while suppressing an increase the mass of a tire and a deterioration in rolling resistance performance of the tire. <P>SOLUTION: This run-flat tire 1 includes: a carcass 6 which leads to a bead core 5 of a bead part 4 via a sidewall part 3 from a tread part 2; a belt layer 7 which is arranged on the radial-direction-of-tire outside of the carcass 6 and inside the tread part 2, and which has a belt cord inclined at an angle of 15-45 degrees with respect to a tire equator C; and an approximately crescentic cross-section reinforcing rubber layer 10 that is arranged inside the carcass 6 of the sidewall part 3. The carcass 6 includes a two-ply structure that includes an inner ply 6A made of a carcass cord 11A having heat shrinkage stress S1 at 130°C set at 4.0 N or less, and an outer ply 6B arranged on the outside of the inner ply 6A and made of a carcass cord 11B having heat shrinkage stress S2 at 130°C set at 8.5 N or more. <P>COPYRIGHT: (C)2013,JPO&INPIT |
