| 摘要 |
PURPOSE:To improve the ice snow characteristic and facilitate manufacture by specifying the heardness of a tread part, the tilt angle, depth, and quantity of sipings formed on each block of a crown part and a shoulder part and the ratio of the longitudinal length to lateral length of the block. CONSTITUTION:A shoulder block row LS, crown block row LC and an intermedi ate block row LM are arranged in a tread part 2. Further, shoulder sipings SS and crown sipings SC are formed on the shoulder block BS and the crown block CS. Further, the tilt angle (alphac) of the SC for the tire equator C is 90 + or -10 deg. and over the tilt angle of the SS, and the depth of the SC is smaller than the depth of the SS, and the quantity of the SC is set less than the quantity of the SS. While, in the intermediate block BM, the longitudinally long block BMl having the ratio the longitudinal length to the lateral length l/w of 1.2 or more and the laterally long block BMw having the ratio of 0.9 or less are formed. The ratio l/w of the longitudinal length to the lateral length of the shoulder block BS is set to 1.2 or more. |
