| 摘要 |
PROBLEM TO BE SOLVED: To provide a molding tool and a molding method for performing highly precise molding excellent in roundness and free from warping, falling or the like, improving insufficiency of strength at a weld joint part and making high-cycle molding possible by using a high-speed charging and low-pressure compression injection molding method, in the molding tool and the molding method for manufacturing an annular component made of synthetic resin material, for example, the retainer of a roller bearing. SOLUTION: While retreating an annular piston which clamps the inner part of an annular cavity formed by an upper mold and a lower mold and uniformly compresses the inner part of the annular cavity, the melt synthetic resin material is charged by a specified quantity into the cavity from the inside part of the cavity via a spool, a runner and a submarine gate, after or simultaneously with the charging, the piston is advanced to block the submarine gate and separate the inner part of the cavity, further, the piston is advanced and, thereby, high-density melt synthetic resin material is uniformly compression-molded throughout the whole inner part of the cavity. COPYRIGHT: (C)2009,JPO&INPIT |
