| 摘要 |
PURPOSE:To maintain a constant cavity pressure and obtain solid painting material which has no stripe-pattern and is difficult to break by withdrawing the core pins in the mold cavity in accordance with the movement of the screw in an injection cylinder in order to maintain a constant cavity pressure. CONSTITUTION:A screw 4 turns and moves forwards, and a rack 11 causes a pinion 12 to rotate, consequently a potentiometer 10 operates to detect the screw position, which is converted into a speed signal in a speed detecting circuit 13. The speed signal is applied through an amplifier 14 to a current controller 8 to control the valve opening so that an oil-hydraulic cylinder 7 is operated at a speed according to the speed signal. Accordingly, a core plate 5 and core pins 6 unitary therewith are withdrawn at a speed according to the speed of the screw 4 to perform injection molding. |
