| 摘要 |
PROBLEM TO BE SOLVED: To extend the life of a mold by reducing deformation, peeling or damage of a sipe when a tire is molded by using the mold having the sipe cast therein, for forming fine grooves in the tire. SOLUTION: The sipe 124a shown by a broken line, which is cast into an aluminum alloy mold 128 and provided at the block end part 122 of the aluminum alloy mold 128, has a mold release angleθa of about 17 deg.. The sipe 124a is inclined in the upward mold release direction of the aluminum alloy mold 128 to be set as a sipe 124b having a mold release angleθb of about 7 deg.. The sipes 124a and 124b to be used have a thickness of 0.6 mm and the distance between the block end surface 126 of the mold and the sipes 124a and 124b, that is, the wall thickness(t) of the block end part 122 is set to about 2.0 mm. By this method, a problem such as the deformation, peeling or the like of the sipes 124a and 124b can be eliminated to a large extent by a simple method for altering only the mold release anglesθa andθb of the sipes 124a and 124b when the sipes 124a and 124b are cast without providing a projection or the like. |
