| 摘要 |
PURPOSE:To uniform each rigidity of the obtuse area and the acute area of the land area of the tire, so as to obtain the restraint of a deflective abrasion and the like by gradually increasing the inclination of the side wall of the land area formed by each lateral-direction and circumferential-direction main groove from the obtuse corner area to the acute corner area. CONSTITUTION:A tire 11 has plural circumferential-direction main grooves 13 placed in the center range 12b on the surface area 12a of a tread 12, and a couple of circumferential-direction main grooves 15 placed on the both-side areas 13c of the center area. And each of plural lateral-direction main grooves 18 with a termination area 18a extending toward the center area C from a tread end area 12d to a side rib 16 as land areas is provided in the surface area 12a of the tread 12. And plural blocks 20, 21 as a land area are formed by each main groove 15, 18. In this structure, the angle of the side wall 15c of the block 20 is gradually increased from an obtuse corner area F with a minimum groove wall angle to an acute corner area E with a maximum inclination. And also, the inclination of a block-shaped side area 16a is provided in the same way. |
