Patent ID: 9682423
Date: 2017-06-20
CPC Classifications: B22D

Claim:
1. An electric die casting machine, comprising: a screw shaft which is held rotatably; a nut body which is threadably mounted on the screw shaft to be able to move forward and backward; an injection plunger which moves forward and backward in conjunction with the forward and backward movement of the nut body; an injection electric servo motor and an intensification electric servo motor which drive and rotate the screw shaft; a one-way clutch which is provided between the screw shaft and the intensification electric servo motor; and a controller which controls the injection electric servo motor and the intensification electric servo motor; wherein: the one-way clutch is attached so that, when the screw shaft is driven and rotated in a direction to drive and move forward the injection plunger, the one-way clutch rotates idly if a rotation speed of the screw shaft driven and rotated by the injection electric servo motor is higher than a rotation speed of the screw shaft driven and rotated by the intensification electric servo motor, and the one-way clutch transmits a torque of the intensification electric servo motor to the screw shaft if the rotation speed of the screw shaft driven and rotated by the injection electric servo motor is lower than the rotation speed of the screw shaft driven and rotated by the intensification electric servo motor; and the controller controls the injection electric servo motor in accordance with a predetermined drive condition to execute a low-speed injection step and a high-speed injection step in an injection step, and starts up the intensification electric servo motor during deceleration control of the injection electric servo motor in the high-speed injection step or before the start of the deceleration control to execute an intensification step following the injection step.