| 摘要 |
PURPOSE: To perform the injection molding or a plastic product by using a pressure fluid by injecting molten plastic into a mold cavity and introducing a fluid into a flow path to house the same in a product until the product is solidified. CONSTITUTION: Plastic is melted to be supplied to the front chamber of a cylinder 34 by a rotary screw 36 and the molten plastic is passed through a nozzle 18 by advancing the screw 36 to be sent to a flow path 16. The filling gas of the second chamber 50 of a cylinder 42 communicates with a lower fluid injection orifice 30 through segments 26, 28 and the fluid pressure in the orifice 30 is set to a predetermined level smaller than the injection pressure of plastic. After an injection stroke is completed, the pressure of plastic is lowered to the predetermined pressure of a fluid or less and plastic enters a flow path mold cavity. The gas passes through the min. resistance passage in the mold cavity to cool the molten plastic and the gas pressure applies constant oil pressure to a compression piston 44 to be held to a constant level. When a plastic article is sufficiently cooled, the gas is discharged through passages 26, 28 by regulating a valve 54. |
