TREAD DESIGN FOR H/D RADIAL TYRE

摘要

PURPOSE:To reduce the effect of RRO on RFV so as to improve the performance of the comfortableness to drive by setting a crown part so as to reduce the shape coefficient defined by a specific equation and to make the value almost constant as compared with a shoulder section on both sides. CONSTITUTION:A tread part is provided with a pair of longitudinal grooves G1 and G2 that are extended in the circumferential direction of a tire at the position of approximately 30% in the distance from tire equatorial surface C to right and left treads ends TE and is also partitioned into crown part CR and shoulder part SH. In this case, the crown part CR is set so as to reduce the shape coefficient defined by the following equation and to make the value almost constant as compared with the shoulder part SH. That is, the equation can be defined as Shape coefficient F = Load area AL/Free surface area AF. Where, the load area AL is specified as the effective ground area of the tread part and the free surface area AF is the total area of the block or rib side wall of the tread part.