Patent ID: 9718314
Date: 2017-08-01
CPC Classifications: B60C

Claim:
1. A pneumatic tire, comprising, in a tread portion, a center rib formed by two circumferential main grooves extending along a tire circumferential direction in a center of a tire width direction including a tire equatorial plane; wherein a main inclined groove and an auxiliary inclined groove are formed in the center rib, the main inclined groove being provided so as to incline with respect to the tire circumferential direction in a manner so as to become distanced from the tire equatorial plane from a leading side toward a trailing side in a tire rotational direction, a trailing end communicating with the circumferential main groove, a plurality of the main inclined grooves being juxtaposed in the tire circumferential direction and disposed alternately in the tire circumferential direction on both sides of the tire equatorial plane; the auxiliary inclined groove being provided so as to incline with respect to the tire circumferential direction in a manner so as to become distanced from the tire equatorial plane from the leading side toward the trailing side in the tire rotational direction, a leading end and a trailing end terminating within the center rib while intersecting at least two of the main inclined grooves, a plurality of the auxiliary inclined grooves being juxtaposed in the tire circumferential direction and disposed alternately in the tire circumferential direction on both sides of the tire equatorial plane, mutual leading end sides of the main inclined grooves disposed alternately in the tire circumferential direction extend beyond the tire equatorial plane and are in communication, and form a zigzag shaped central groove along the tire circumferential direction on the tire equatorial plane where a distance in the tire width direction from the tire equatorial plane to the central groove varies gradually and continuously; a groove width of the central groove being formed so as to be in a range of not less than 2 mm and not greater than 6 mm, and the main inclined groove has a curved shape being curved such that an angle of the inclined main groove with respect to the circumferential direction gradually and continuously increases from the leading end of the main inclined groove to the trailing end of the main inclined groove.