| 摘要 |
PROBLEM TO BE SOLVED: To prevent a mold release unevenness, pit deviation or the like by substantially simultaneously releasing an outer peripheral ring from both a pair of molds in the case of opening the mold after molding. SOLUTION: An outer peripheral ring 4 is mounted at molds 2, 3 for forming a cavity via springs 8 or the like. The spring 8 is constituted to operate a force in a direction for opening the ring 4 and the molds 2, 3. After molten resin is cast in a mold 1, it is cooled, and the mold is opened. The ring 4 is supported to hold the ring 4 at an intermediate position between both the molds 2 and 3 by an operation of the spring 8, and the ring 4 is substantially simultaneously released from the pair of the molds 1. At this time, a molding disk 7 held by the ring 4 is substantially simultaneously released from both the molds. And, to release the ring 4 from both the molds 2, 3, the spring 8 is used, or a method of pneumatic, hydraulic pressure or the like is used. Thus, a mold release unevenness, a pit deviation or the like can be prevented. |
