| 摘要 |
PURPOSE:To improve turning property on the surface of frozen and wet road by forming a narrow width land section and a wide width land section which are narrow grooves which tilt in the direction of width of stepping face at the predetermined angle and have the predetermined wall thickness respectively in a land section which consists of a main groove and an auxiliary groove, and setting thickness of the land section which is orthogonal to the narrow groove to the predetermined thickness in a studless tire. CONSTITUTION:A tread face 1 consists of main grooves 2 and auxiliary grooves 3 to form land section divisions 4. Further, a narrow groove 5 which tilts at the inclination angle theta1 of 45 deg. or more for the direction of width of the stepping face 1 is formed in each land section division 4 to divide into a narrow width land section 6 and a wide width land section 7. Average thickness T which is measured in the orthogonal direction of groove wall of the narrow groove 5 of the land section division 4 is set to 1.5 times or more thickness from the bottom of the narrow groove 5 to the bottom of a mutually divided groove 2. Also, wall thickness TS of the narrow width land section 6 is set to 0.1 to 0.5 times depth h of the narrow groove 5, and thickness TL of the wide width land section 7 is set to 0.78 times or more depth (h) of the narrow groove 5, respectively. |
