| 摘要 |
PURPOSE:To improve durability of a belt part, and reduce the occurrence of the failure of separation by making the belt part which is interposed between the carcass part and the tread part of a radial tire, in at least three layers and considering the providing position, etc. of each belt layer. CONSTITUTION:A radial tire 1 has a carcass part 6 which has at least one layer of carcass layer 6, and a belt part 7, which is placed on the outside in the radial direction of tire of the carcass part 6 and inside a tread part 2. The belt part 7 consists of at least three layers of mutually parallel cords 9-9'' which are covered by a rubber layer, and these layers are placed in the order of the first to third belts 10-12 from the inside in the radial direction of tire, with a certain layer distance D0 (approximately 0.7mm.) being provided. The cords 9', 9'' are placed so as to cross each other, and the first belts 10 have a cord direction of 40-60 deg. to the equation plane of tire, and are separated from each other right and left symmetrically with respect to the equation plane. |
