INJECTION-MOLDED HOLLOW ARTICLE, HOLLOW INJECTION INJECTION-MOLDED HOLLOW ARTICLE, HOLLOW INJECTION MOLDING METHOD AND METAL MOLD THEREFOR MOLDING METHOD AND METAL MOLD THEREFOR

摘要

Disclosed is an injection-molded hollow article having large hollow portions 1 which securely provide the strength required by the injection-molded hollow article without depending upon ribs as more solid remaining portions being unstable in position and size. A melted resin and pressurized fluid are injected under pressure into a metal mold cavity 4, a movable core 5 projected into the metal mold cavity 4 is moved and then a support portion 2 is formed at the position from which the movable core 5 is moved. The position and size of the support portion 2 can be determined by selecting the position and size of the movable core 5.