| 摘要 |
PURPOSE:To stably and effectively evacuate molds to vacuum at low cost by a method in which solenoid switching valves are provided to a cavity side and vacuum pump side ports of a tank leading to the vacuum pump in the exhaust pipeline of the mold cavity, and a branched pipe leading to the atmospheric pressure is provided through a solenoid switching valve between the cavity and the solenoid switching valve. CONSTITUTION:When the internal pressure of a tank 16 reaches a given pressure, it is detected by a pressure switch 19, a timer 35 begins to count by the operation of the pressure switch 19, A-contact 1TR1 is connected, and the timer 35 is self-holded. Since the pipeline is opened at the same time, a cavity 12 is connected with the tank 16, and the air, etc., of the cavity 12 is sucked into the tank 16. When the evacuating operation is ended, a vacuum pumps 14 begins to operate and the tank 16 is again evacuated. On the other hand, when time set to an injection-operating timer 38 by the time-out signal of the timer 35 is suspended, a carrying timer 41 begins to operate, the pipeline 20 is opened by the time- out signal of a carrying time relay 41, and the cavity 12 is led to the open air. |
