Servo-driven clamping unit for use in injection molding machine

The present invention relates to servo-driven clamping units for use in injection molding machines, and more particularly, to a servo-driven clamping unit for use in an injection molding machine, which can facilitate precise positioning control of mold clamping, so as to improve stability and reliability for proceeding an injection molding process. A clamping unit for use in an injection molding machine is proposed, wherein a plurality of tie bars are symmetrically positioned and mounted in parallel to corners of a front platen and a rear platen, and a movable platen is movably sleeved about the tie bars and positioned between the front and rear platens. A servo-motor mounted on the rear platen acts as a power source for operating the clamping unit. A belt-gear mechanism associated with the servo-motor transmits torque force and turning speed provided from the servo-motor to a ball screw transmission mechanism connected to the belt-gear mechanism. The ball screw transmission mechanism converts the torque force into axial pushing force, so as to drive a toggle linkage mechanism that interconnects the rear platen and the movable platen, and move the movable platen along the tie bars for performing mold-opening and mold-clamping operations.