| 摘要 |
PURPOSE:To obtain a technique for efficiently producing an injection molded piece having a superior appearance and a larger hollow structure. CONSTITUTION:A mold with a core 3 retractably disposed orthogonally to a parting line is provided with a mechanism consisting of a piston 11 fixed to the back face of the core 3 and a hydraulic cylinder 10 fixed to a movable clamping plate 2a for moving the core 3 forward and backward and a piston actuating mechanism, which is composed of a low hydraulic pressure supply means provided with a pump 23, a pressure regulating valve 20, and a flow regulating valve 22 for transmitting a low pressure to a rear chamber of the hydraulic cylinder; a high hydraulic pressure supply means provided with the pump 23 and a pressure regulating valve 19 for transmitting a high pressure to a front chamber 10b or the rear chamber of the hydraulic cylinder; and a hydraulic pressure discharge means provided with a proportional pressure regulating valve 21. |
