| 摘要 |
PURPOSE:To improve water runaway ability and prevent hydroplaining from occurring by providing curved grooves in a hyperbola shape which extends toward a shoulder part gradually in a tire anti-rotation direction with the part in vicinity of a main groove taken as a starting point respectively on both the right and left sides of the main groove in a treat surface. CONSTITUTION:A tread pattern is a directional pattern with an arrowheaded direction T taken as a tire rotational direction. With this constitution, one main groove 2 which continues over the whole periphery in a tire peripheral direction EE' is provided at the central part of a tread surface 1, and plural sub-grooves 3 which continue from the main groove 2 to both shoulder ends on both of right and left sides are provided. Besides, plural curved grooves 5 in a hyperbola shape are provided from a position in vicinity of both the sides of the main groove 2 to both side shoulder parts 4, 4. The curved grooves 5 are formed so that its tangential line in vicinity of the main groove may have an angle of 0-45 degree to the tire peripheral direction, its tangential line at the shoulder part may have an angle of 45-90 degree to the tire peripheral direction and the curved grooves may be drawn in a hyperbola shape in a top view. |
