| 摘要 |
PURPOSE:To prevent deviated wear of a tread by a method wherein blocks are divided into a plurality of regions, having different sizes, by means of a plurality of sipes having given depth and inclination angle so that the widths thereof satisfy respective specified relations. CONSTITUTION:Blocks 3 surrounded with circumferential main grooves 1 and lateral grooves 2 are divided into three or more regions 6 by means of sipes 5 with a depth being 0.4-1.0 time as large as the depth of a deepmost groove surrounding the block 3 and an average angle of 45-90 deg. with the circumferential direction of a tyre. The width of region 6a on both ends, each nipped by the sipe 5 and the lateral groove 2, of the regions 6 is set to a value lower than that of an intermediate region 6b nipped on both sides by the sipes 5, and a ratio b/a between the two widths is set to 0.8 or less. An average width (a) of the region 6a at least the one end is set to 25-40% of the length, in the circumferential direction of a tyre, of the block 3. This constitution enables prevention of deviated wear of a tyre. |
