| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic tire for a heavy load having a block land portion on a step face of a tread, which can highly suppress a separation failure between a tread rubber and a belt by reducing a shearing strain quantity and a calorific value in a tire circumference direction in a tread part.SOLUTION: A tire has, on a step face of a tread, blocks partitioned by a plurality of circumferential main grooves continuously extending in a tire circumference direction and a plurality of crossing grooves that communicate circumferential main grooves adjacent in a tire width direction with each other. In a region in the tire width direction having a width in the tire width direction that is 50% of the width of the tread with a tire equator as a center, in at least one block of the blocks is provided with a block dividing groove, which is opened to each of the crossing grooves partitioning the blocks and shallower than the circumferential main grooves, and the one block is divided into a plurality of small blocks, and in at least one block of the small blocks is provided with a block sub groove, one end of which is opened to the block dividing groove and the other end of which is opened to the circumferential main grooves or the crossing grooves, which is shallower than the circumferential main grooves. |
