Servo-driven clamping unit for use in injection molding machine

A clamping unit for use in an injection molding machine, comprising:

• a plurality of tie bars symmetrically positioned and mounted in parallel to corners of a front platen and a rear platen;
• a movable platen movably sleeved about the tie bars and positioned between the front and rear platens;
• a servo-motor mounted on the rear platen, for providing power for operating the clamping unit;
• a belt-gear mechanism associated with the servo-motor, for transmitting torque force and turning speed provided from the servo-motor;
• a ball screw transmission mechanism including a ball screw and a guide device connected to the belt-gear mechanism, for converting the torque force transmitted from the belt-gear mechanism into axial pushing force, wherein the guide device is formed with a threaded hole for allowing the ball screw to be inserted through the threaded hole;
• a toggle linkage mechanism for interconnecting the rear platen and the movable platen, and bearing the axial pushing force from the ball screw transmission mechanism so as to drive the movable platen to move along the tie bars.