| 摘要 |
<p>A method of blow molding and a pressurized fluid injection and discharge device therefor, wherein a pressurized fluid is injected to thereby form a hollow portion in molten resin in a mold cavity, and it is an object of the present invention to eliminate back flow of the molten resin into a pressurized fluid path and perform reliable injection of the pressurized fluid and quick discharge of the pressurized fluid. A space formed between a tubular sleeve and a shaft core inserted into this sleeve is made to be a pressurized fluid path, the forward end of the shaft core is allowed to project into a mold from the sleeve, and with the outer peripheral surface of the projection portion of the shaft core used as a guide surface and, further, by sliding of the shaft core, an opening of the pressurized fluid path on the side of the mold is changed over between a narrow-down state, in which the pressurized fluid is allowed to pass therethrough but the molten resin is prohibited from intruding, and an enlarged state. The shaft core is slid to change the width of the opening of the pressurized fluid path on the mold side, so that the back flow of the molten resin can be prevented, the pressurized fluid can be quickly discharged and the reliable injection of the pressurized fluid can be carried out by the guide surface.</p> |
