| 摘要 |
PURPOSE:To reduce the amount of steel cord thus to reduce the weight by coating specific coat rubber over the steel cord in belt layer while setting the tensile resiliency factor of organic fiber cord in carcass to specific level. CONSTITUTION:A carcass 2 composed of organic fiber cords is arranged in parallel with the meridian cross-section of tire while a belt layer 3 composed of rubbered steel cord is arranged between the carcass 2 and the tread 1. Here the steel cord in the belt layer 3 is coated with rubber coat having has the breakdown strength F(kg) defined by the formula I (where, n: number of strands, d: diameter of strand mm.) and 50% modulus within the range of 10-40kgf/cm<2>. The organic fiber cords in the carcass 2 are set such that the tensile resiliency factor of single cord will be higher than 1,800kgf/mm.<2>. With such arrangement, the purpose can be achieved without deteriorating the steering stability and the fuel consumption. |
