| 摘要 |
PURPOSE:To contrive to reduce plys-tear caused by a belt reinforcement layer and consequently to improve the straight running property and the durability at high speed running by a structure wherein the angle of the reinforcement cords of a carcass cord layer consisting of a single layer toward the peripheral direction of the tyre is taken in the range of 66-82 deg.. CONSTITUTION:A carcass cord layer 4 is arranged so that its angle alpha is made an angle of 66-82 deg. when measured from the side, from which of the peripheral direction of the tyre the reinforcement cords of a lower belt reinforcement layer 5d is measured acute. If the angle alpha is larger than 82 deg., plys-tear is not made better than its conventional level, while if the angle alpha is smaller than 66 deg., the plys-tear is improved further, however the load durability is lowered. When the angle alpha lies in the range of 66-82 deg., the plys-tear is made better than that of the conventional radial tyre, the angle alpha of which is 90 deg., resulting in improving the straight running stability and the durability at high speed running. |
