| 摘要 |
PURPOSE: To make hollow part in the molding plastic material in a cavity by supplying pressured gas and stopping supply of the gas to open a valve communicated to the hollow in order to vent the gas in the hollow to atmosphere after molding. CONSTITUTION: A plastic material 19 is put into a mold cavity 13 through a hot runner manifold 17 by operation of a screwed ram 18. Simultaneously a delay timer starts to activate at the end of the time a solenoid valve 40 in order to fill the outlet of a nozzle 26 with plastic material. The gas is poured into the plastic material through the nozzle 26 using a piston 33 and cylinder 34 by opening of a valve 36 to make a hollow part containing the gas in the plastic material and spread the plastic material over the whole area in the mold cavity. After curing of the plastic, the valve 36 is closed, the piston 33 is returned, the valve 40 works in reverse to return the nozzle 26 and vent the gas in the hollow to atmosphere through the valve outlet 42. |
