| 摘要 |
PURPOSE:To reduce the generation of type noise, by a method wherein trim remaining projected parts of a vent hole burr are formed in a given region of a tread surface. CONSTITUTION:Trim remaining projected parts 4, 4... of vent hole burr are left remaining in a region except a region A nipped by a position (e) 5 mm inner than an earthing end E of a tread surface, determined according to a JIS standard condition and a position (m) 5 mm outer than a central line M of an outermost main groove 2. This constitution enables reduction of the generation of type noise. |
