Tire

摘要

In the tire (1), a region of the tread portion (10) overlapping with a range of 80% of a length of the circumferential belt layer (40) in a tread widthwise direction around a tire equator line CL is a central region CR in the tire radial direction trd, and a remaining region of the tread portion (10) is a terminal region TR, a maximum curvature radius of the arc portion of the central circumferential groove 50a is R1, a minimum curvature radius of the arc portion of the terminal circumferential groove 50b is R2, a maximum depth in the tire radial direction trd from the tread surface (11) to a groove bottom 55a of the central circumferential groove 50a is D1, a maximum depth in the tire radial direction trd from the tread surface (11) to a groove bottom 55b of the terminal circumferential groove 50b is D2, and a relationship of R1/D1≦0.130 and a relationship of R2/D2>0.195 are satisfied.

主权项

1. A tire which comprises
a tread portion having
a tread surface that comes into contact with a road surfaceand a circumferential groove that extends in a tire circumferential direction,in a cross section taken along a direction orthogonal to an extension direction of the circumferential groove and along a tire radial direction,
a groove bottom of the circumferential groove having one or more arc portions each of which is formed in an arc shape, anda center of every arc of the arc portions being positioned outside of tire material, the tire comprising: a circumferential belt layer located inside of the tread portion and extending in the tire circumferential direction; and a crossing belt layer located outside of the circumferential belt layer in the tire radial direction, wherein
a region of the tread portion overlapping with a portion of the circumferential belt layer in the tire radial direction is a central region such that the overlapping portion has a 80% width of the circumferential belt layer in a tread widthwise direction with a center thereof positioned on a tire equator line, anda remaining region of the tread portion is a terminal region, wherein
cords of the crossing belt layer cross cords of the circumferential belt layer, wherein
the circumferential groove located in the central region is a central circumferential groove, andthe circumferential groove located in the terminal region is a terminal circumferential groove, wherein
a maximum curvature radius of the arc portion of the central circumferential groove is R1,a minimum curvature radius of the arc portion of the terminal circumferential groove is R2,a maximum depth in the tire radial direction from the tread surface to a groove bottom of the central circumferential groove is D1,a maximum depth in the tire radial direction from the tread surface to a groove bottom of the terminal circumferential groove is D2,a relationship of R1/D1≦0.130 and a relationship of R2/D2>0.195 are satisfied, anda round non-contact area of the tread surface is 20% or smaller with respect to an area of the tread surface.