| 摘要 |
<p>PURPOSE:To improve high-speed durability and wear resistance, reduce shoulder wear and prevent decrease in wet grip and traction performance during the latter available period of a tire by arranging horizontal holes in line which pass through respective shoulder portions and have respective innermost ends positioned nearer to the shoulder sides than vertical groove sides at buttress portions of a tire. CONSTITUTION:Each horizontal hole 8 provided in a tire 1 diffuses heat generated inside each shoulder portion 5b by rotational movement of the tire 1 for air cooling, thus preventing tread separation at a tread part 5, especially at one edge of a belt layer 14 and improving high-speed durability of the tire 1. Rising temperature restriction of the shoulder portion 5b permits the thickness of a rubber at the tread part 5 to be increased and wear resistance life to be lengthened. The horizontal hole 8 exposed to the surface of one tread at the latter wear period prevents decrease in wet grip and traction performance. In addition, termination of the innermost end of the horizontal hole 8 on the shoulder side of a vertical groove 6 prevents decrease in rigidity and also reduces shoulder wear.</p> |
