Patent ID: 9033012
Filing Date: 2015-05-19
Classification: B60C,Y10S

Abstract:
1. A tire comprising a plurality of rib-shaped land portions extending in a tire circumferential direction, the tire having a circumferential groove formed which is adjacent to the land portions and which extends in the tire circumferential direction, wherein the circumferential groove includes: a first groove portion formed between adjacent ones of the land portions; and a second groove portion being adjacent to the first groove portion in the tire circumferential direction and formed between the adjacent land portions, the first groove portion has a shape which becomes narrower in the tread width direction toward an inner side in a tire radial direction, and the second groove portion is formed of: side walls located respectively on both sides in the tread width direction and extending in the tire radial direction; and a groove bottom continuous with the side walls and extending in the tread width direction, and the second groove portion is recessed more inwardly in the tire radial direction than the first groove portion with a groove bottom of the first groove portion being an upper end of the second groove portion, wherein the first groove portion is curved such that an angle formed between the first groove portion and the straight line orthogonal to a groove center line of the circumferential groove becomes larger toward the groove center line, and the second groove portion is curved such that an angle formed between the second groove portion and the straight line orthogonal to the groove center line becomes larger toward the groove center line, wherein the first groove portion is formed of a first inner groove and a first outer groove, and the first inner groove and the first outer groove are curved to be opposite to each other in the tire circumferential direction.