| 摘要 |
PURPOSE:To improve off-road running performance and sound performance by arranging U-shaped tire block sets, whose closed sides are connected back to back each other and open sides are faced to the tread end, alternately each other in the tire circumferential direction. CONSTITUTION:Main groove group is formed with zigzag-shaped circumferential- direction main grooves 10 extending on a tread surface along the tire equator face O, main lug grooves 20 extending from each vertex of zigzags to the tread end, and sub lug grooves 21 being unopen to the circumferential-direction main grooves 10 at their tire equator face 0 side. The sub lug grooves 21 and the main lug grooves 20 are connected to the first and second sub grooves 30, 31 and the sub lug grooves 21 and connecting parts 11 of the circumferential-direction main grooves 10 and the main lug grooves 20 are connected to the first and the third sub grooves 30, 32. Formation of these grooves allows to form a block pattern in which U-shaped block sets, whose closed sides are connected back to back each other at the tire equation face O side and open sides are faced to the tread end, are arranged alternately each other in the tire circumferential direction. Thus the pneumatic tire can secure superior performance in start, straight running, traction property and sound property equally during off-road running. |
