Control device and control method for injection molding machine

A control device for an injection molding machine including a cylinder into which a resin is supplied, and a screw configured to move forward and rearward and rotate inside the cylinder, the control device comprising:

• a metering control unit configured to perform metering of the resin inside the cylinder by controlling a forward rotation and a rearward movement of the screw until the screw has been moved rearward to a predetermined metering position, based on a predetermined metering condition;
• a rearward movement speed acquisition unit configured to acquire a rearward movement speed of the screw during metering;
• a speed determination unit configured to determine a suck back speed in order for a pressure of the resin to be made to reach a target pressure, based on the rearward movement speed of the screw acquired during metering by the rearward movement speed acquisition unit;
• and
• a suck back control unit configured to cause the screw to be further moved rearward based on the suck back speed, after the screw has reached the predetermined metering position.