| 摘要 |
PURPOSE: To reduce the irregular wear of the tread having a V-shaped inclined main groove by providing the groove wall of the tip part of the main groove, a main part and a rear end part of U-shape in the prescribed angular range, and providing the groove wall of the main part and the rear end part where the step-in side is inclined at the angle larger than that of the kick-out side. CONSTITUTION: A main groove 2 consists of the tip part (x) at the center region X corresponding to 20% of the main tread width W around the equatorial plane O, a main part (y) in the middle region Y corresponding to 30% of the main tread width W on each side, and a rear end part (z) in an end part region Z between the middle region and the main tread end. The groove walls of the tip part (x) of the main groove, the main part (y) and the rear end part (z) present the U-shape open in the angular range of 0-10 deg., 5-20 deg., and 5-15 deg. respectively relative to the normal of the main tread surface, and in the groove walls of the main part (y) and the rear end part (z), the step-in side in inclined at the larger angle than the kick-out side. The irregular wear of the tread can be reduced thereby. |
