| 摘要 |
PURPOSE:To effectively prevent river wear generated at rib ends of both sides of a vertical groove. CONSTITUTION:A notch 7 whose width and depth extend toward a groove bottom 10 of a vertical groove 3 is formed on a groove wall of the vertical groove 3, and an inverse inclined part 13 is arranged at a trough part 12 of the notch 7 in which profile R of the trough part 12 is inclined in the direction extending to the groove width of the vertical groove 3 opposite to the inclination of the groove wall forming an angle theta against a vector N against the surface of a tread part. |
