| 摘要 |
PURPOSE:To prevent gas contained in resin flowing through a cavity space in an injection mold for producing a molded product of a hollow article from being stuck on a fixed pin and a void pin, enable air to be stably introduced, prevent reliably sink from occurring by the cooling of resin, and carry out continuous molding without any trouble. CONSTITUTION:A spring 8 is provided in a fixed pin 2 at the place of a flange 3a of a void pin 3 for processing. When air is admitted through an air admitting plate 7, the void pin 3 is slidingly moved by pushing up the flange 3a of the void pin 3 with the aid of an air pressure. After the stopping of air admission, the void pin 3 is returned to the former state that the void pin has taken before air is admitted, by means of the spring 8 interposed between the fixed pin 2 and the flange 3a of the void pin 3. According to a series of these operations, even when gas contained in resin infiltrates into a very small gas between the pins, gas is hardly stuck on the pins because the void pin is slidingly moved. |
