Controller for adjusting zero point for load cell in a motor-driven injection molding machine

A motor-driven injection molding machine, comprising:

• an injection device driven by a servo motor;
• a load cell for use in detecting a pressure of a molten resin stored in front of a screw;
• a position detector for detecting a position of the screw;
• and
• a controller for controlling said servo motor in accordance with detected values obtained by said load cell and said position detector,
• wherein said controller is configured to control said servo motor, in response to a command to adjust a zero point for said load cell, to move said screw a plurality of back and forth movements such that said screw is moved in a retracting movement and in an advancing movement during each back and forth movement, and calculates an average value of a corresponding plurality of detected values obtained by said load cell during each back and forth movement of said screw to adjust the zero point for said load cell.