| 摘要 |
PURPOSE:To hold the density of a molded form constant and to obtain a disk having high quality by previously setting the function of injection velocity so that the velocity of a fluid tip of resin material is specified in a cavity in the interval of one part in an injection step, varying and controlling the injection velocity on the basis of the function at time of injection. CONSTITUTION:Packing of resin material is performed for a sprue part 3s at the specified injection velocity V1 which is firstly set at the comparatively low velocity in an injection step. When the position of a screw 11 reaches the position correspondent to the volume of the sprue part 3s, a position detection part 6 detects this position and the injection velocity is changed over for function control. Transfer distance X of the screw 11 is imparted to a central arithmetic part 20 and the same 20 calculates the injection velocity by the function preset in a function setting part 5. The command value correspondent to the injection velocity Vs is imparted to an electromagnetic proportional flow rate controlling pump 22 via an output part 21. The pump 22 controls the flow rate of hydraulic fluid for an injection cylinder 16. The advancing velocity of the screw 11, namely the injection velocity is continuously varied and controlled. Therefore the velocity V of the fluid tip is held constant even when the volume of the cavity 3 is increased according to progress of packing of the resin material. |
