| 摘要 |
PURPOSE:To prevent the occurrence of hydro-planing on a road having a rain group, by a method wherein at least 2 circumferential grooves are provided in the outer peripheral surface of a tread along the peripheral direction of the tyre, and the angle of the circumferential groove with the equator surface of a tyre is specified. CONSTITUTION:For example, 6 circumferential grooves 7 are formed along the peripheral direction of a tyre in an outer peripheral surface 2a of a tread part 2 of pneumatic tyre. The circumferential groove 7 is formed at an angle alphaof 1-25 deg. with an equatoral surface E of the tyre. Adjoining circumferential grooves 7 have central lines paralleling each other, but each central line is extended so that it has at least 2 bending points 8 at which it is bent in the direction of length as shown in a development A. The use of said tyre enables prevention of the occurrence of hydro-planing phenomenon in which a tyre is brought to a floating state and phenomenon in which a handle is rendered ineffective when running at a high speed on a rainy day on a road, having a rain group, where a number of fine groove lines are formed in a whole road surface in parallel to the advancing direction of a car. |
