| 摘要 |
PURPOSE:To prevent heat emission and deterioration of rubber by forming the tread crown part of a pneumatic tire from a cap rubber layer made from a specific foaming rubber and base rubber layer made from non-foaming rubber, and enlarging the volume fraction of the base rubber layer having a large resilience. CONSTITUTION:A pneumatic tire 1 is so structured that the volume fraction of a base rubber layer 8 is 0.5 or more relative to the whole rubber area of a tread crown part 6. The resilience of a cap rubber layer 7 is set to 30-60% while the resilience of the base rubber layer 8 set to 45-75%. wherein the resilience of the base rubber layer 8 is made larger by 5% of that of the cap rubber layer 7. The tread crown part 6 is fitted with two main grooves for dividing into tread land parts in the central area and the two shoulder areas, two thin grooves to divide the central area, and crosswise grooves intersecting them, and with these grooves a number of land blocks are generated. The land blocks are provided with thypes which intersect them across the width. |
