| 摘要 |
PURPOSE:To facilitate shaping of a lug part of a hollow tire and prevent crack initiation at the base of the lug by furnishing this base with a cavity directly leading to the hollow part of tire. CONSTITUTION:Attraction parts 31', 31 are furnished at an upper die 12 and a lower die 11 forming the outer surface of a lug 102, and a protrusion 46 to press its inner surface is provided on a core 20 forming a hollow 108. When the upper and lower dies 12, 11 and core 20 are assembled to perform shaping, attraction is made from the attraction parts 31, 31' while a press is applied by the protrusion on the core 20. Thereby a cavity 108' in communication to the hollow 108 is formed in the base of the lug 102. This prevents crack initiation at the lug and enhances the cushioning property. This also enables the shaping process performed wherein rubber is spread till the tip of lug. |
