Injection molding machine and method of controlling the injection molding machine

Abstract

An injection molding machine comprises a pre-pressure addition meansadding a pre-pressure B acting in the opposite direction of a molding material pressure A received by a screwto a detection meansand/or the screw, the detection meansdetecting the axial pressures A and B of the screw, and a screw movement control meanscontrolling the axial pressure based on a different between the pre-pressure B and the molding material pressure A, wherein the pre-pressure addition meansis made non-contact with the direction means, a forward and backward driving motoris disposed adjacent to a heating cylinder, and a screw connectorat the rear end of the screwis spline-connected inside a rotating rotor of a screw rotating motor. According to the machine, the molding material pressure received by the screw can be accurately detected without being affected by the wear of the machine so as to properly control the axial pressure of the screw and to make the machine compact.