| 摘要 |
PROBLEM TO BE SOLVED: To improve turning performance by balancing a traction property with a slide property. SOLUTION: At least part of a first-come block edge E of a block 11 is provided with a notch 12 comprising a slope 12S formed by notching the block edge E in a chamfered shape. In the notch 12, an angleθof the slope 12S with respect to a ground surface 11S is set at 20 to 70°, and radial depth hb of the notch 12 is set 0.1 to 0.5 times radial height of the block 11. COPYRIGHT: (C)2003,JPO |
