| 摘要 |
PROBLEM TO BE SOLVED: To improve a traction performance of a pneumatic tire on snow by arranging minute grooves of specific dimensions on the groove side walls of longitudinal and/or lateral grooves as well as setting the angles of the groove side walls of longitudinal and lateral grooves within a specific range, in the case of a pneumatic tire including a number of blocks formed by the longitudinal and lateral grooves in treads. SOLUTION: In the tread pattern of a tire, 5 lines of longitudinal grooves 1 provided at intervals in the tire axial direction and extending in the circumferential direction, a number of lateral grooves 2 provided in the circumferential direction at intervals and extending in the tire axial direction and many blocks 3 formed by these longitudinal grooves 1 and lateral grooves 2. In this case, angles of the longitudinal grooves 1 and lateral grooves 2 in relation to the radial direction of the groove side walls are set to 30 to 20deg. And also minute grooves 4 extending approximately in parallel to approximate radial direction are arranged on the groove side walls and the groove width W and groove depth D of these minute grooves 4 are both set to 0.05 to 2mm, the interval L between adjacent minute grooves 4 is less than 1.5mm and the ratio of the groove width W of the minute groove 4 to the distance L between minute grooves 4 is set within a range 0.1 to 0.3. |
