| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To increase the durability of a bead part by preventing CBU (Cord Broken Up) of a carcass cord. <P>SOLUTION: The topping rubber Tg1 of a carcass ply 6A has a hardness Ht1 of 68-90 degrees. A bead core 5 consists of: a bead core substrate 10 formed of the bundle of steel wires 5w; a wrapping material 11 which surrounds the outer peripheral surface of the bead core substrate 10 and which comprises a ply 11A obtained by coating the parallel body of organic fiber cords with a topping rubber Tg2 having a hardness Ht2 of 70-90 degrees; and a bead coating rubber 12 which the gaps between the steel wires 5w is filled with, and which has a hardness Hb of 78-90 degrees. The shortest distance L1 between the steel wire 5w1 of the bead core substrate 10 on the tire axial innermost side and a carcass cord 6c is 0.8-3.0 mm. The organic fiber cord of the wrapping material 11 has a thickness D1 of 940-4,200 dtex, a cord distance W1 of 0.3-1.4 mm, and an angleα1 of 20-70 degrees in the cord longitudinal direction to the tire circumferential direction. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
