Patent ID: 7434606
Filing Date: 2008-10-14
Classification: B60C

Abstract:
1. A pneumatic tire in which a tread surface thereof is divided into a central land portion between inner longitudinal grooves, intermediate land portions between the inner and outer longitudinal grooves, and shoulder land portions axially outside the outer longitudinal grooves, by being provided with the inner longitudinal grooves extending on both sides of a tire equator in a circumferential direction of the tire and the outer longitudinal grooves extending on both sides thereof in the circumferential direction of the tire, a width Wi of the inner longitudinal grooves being 1.1 to 1.5 times a width Wo of the outer longitudinal grooves, wherein the central land portion and the intermediate land portions are formed into circumferential ribs which continuously extend in the circumferential direction of the tire, and on each of the shoulder land portions, blocks divided by lug grooves are arranged as a block row in the circumferential direction of the tire, each intermediate land portion includes inclined grooves extending outward in the axial direction of the tire from an inner end away from the inner longitudinal groove by a small distance La to an outer end which intersects with the outer longitudinal grooves while increasing an angle θ with respect to the circumferential direction of the tire, the angle θ in the inner end is 0 to 25° and the angle θ in the outer end is 60 to 80°, a pitch P the lug grooves each being provided with a groove volume reducing portion in the vicinity of an intersecting portion between the lug grooves and the outer longitudinal grooves, each groove volume reducing portion reducing a groove volume of each lug groove, each groove volume reducing portion being a tie-rod which protrudes from a groove bottom of each lug groove.