| 摘要 |
PURPOSE:To perform a precise pressure control with good responsiveness by a method wherein degree of opening of a proportional electromagnetic flow control valve for controlling feed pressure from a variable capacity pump whose delivery rate of pressure oil can be changed by changing angles of a swash plate is controlled based on set speed in injection loading process and is controlled by comparing feed pressure with set pressure in dwelling process. CONSTITUTION:In injection loading process, injection speed is important and pressure control is not needed. Therefore, degree of opening of a proportional electromagnetic flow control valve EH is set corresponding to speed control values from a CPU14 and molten resin is injected into a mold cavity regardless of pressure. And then in dwelling process, set pressure signals stored in the CPU14 is compared with measured pressure signals of a pressure sensor 16 provided on a secondary side L2 of a delivery line L to control degree of opening of the valve EH so that the measured values conform with set values. In this manner, by performing an open control in the injection loading process and an closed control 'in the dwelling process, precise pressure control can be performed with good responsiveness. |
