Patent ID: 7975738
Filing Date: 2011-07-12
Classification: B60C

Abstract:
1. A pneumatic tire having a tread surface on which block rows are formed, the block rows being constituted of blocks partitioned by vertical grooves extending in the tire circumferential direction and lateral grooves intersecting the vertical grooves and extending in the tire width direction, and on which the blocks are cyclically arranged at two or more different types of pitches in the tire circumferential direction, wherein, on the tread surface, a pitch having a larger pitch length is set to have a smaller groove area ratio per pitch, and to have a larger groove wall angle α on the obtuse angle side that is formed by a groove wall of a lateral groove and a direction tangential to the tread surface, each of lateral grooves partitioning a block row on either shoulder of the tread surface is formed with a depth that becomes smaller toward the outer side of the tire, a protruding portion is formed on the groove bottom of the lateral groove at a tire equator line side, a length of the protruding portion in the longitudinal direction of the groove is set to be from 5% to 50% of a length of the lateral groove, and a height of the protruding portion is set to be from 5% to 85% of a maximum depth of the lateral groove, wherein, in each of the lateral grooves partitioning the block row on either shoulder, a portion of the lateral groove with a smaller depth is formed to have a larger groove wall angle α on an obtuse angle side that is formed by the groove wall and the direction tangential to the tread surface than a portion of the lateral groove with a larger depth.