| 摘要 |
PURPOSE:To obtain a thermoplastic resin molded product free from flaw such as sink caused by the shrinkage of the surface of a thick-walled part and having good appearance using an injection mold. CONSTITUTION:In a thermoplastic resin molded product having a thick-walled part and a thin-walled part, a plurality of small open ports are present in the thick-walled part at predetermined intervals and voids generated by the shrinkage of a peripheral resin are present in the small open ports in parallel to the surface of the thick-walled part. An injection mold has a cavity consisting of a thick-walled part 5 and a thin-walled part. The hollow protruding parts 6a, 6b, 6c protruding into the cavity and the pointed void insertion pins 7a, 7b, 7c piercing through the hollow protruding parts 6a, 6b, 6c to protrude into the cavity are fixed to the place corresponding to the thick-walled part of the mold cavity at a predetermined intervals and the gaps defined by the protruding parts 6a, 6b, 6c and the pins 7a, 7b, 7c communicate with an external gas source. |
