| 摘要 |
PURPOSE:To decrease molding defect and to improve molding efficiency by a method wherein, in a process for retaining the pressure in an injection molding machine with a plurality of cavities, the behavior of fused resin is controlled in continuous comparison with an already specified pattern. CONSTITUTION:Filling-up pressure gradients of fused resin and falling gradients of retained pressure thereof are set in advance to presetting devices 5, 6. After the resin has been injected, the pressures in the dies in each cavity 1a-c are detected by sensors 3 in the dies, amplified with pressure transformers 4 in the dies and input to a controller 9. Comparative operation is exercised with each set valve on the basis of input signals detected by the pressure in the dies and the controlled signals are output from the controller 9, amplified by a power amplifier 10 and the pressure and the flow rate of the working oil supplied to an injection cylinder 15 are controlled properly. |
