Abstract: A motor control device for an electric injection molding machine. The injection molding machine has a screw rotating mechanism including a rotary shaft associated with one end of a resin feeding screw received in a heating cylinder, a holding member rotatably holding said rotary shaft and slidable in the axial direction of said rotary shaft, and a first motor for driving said screw through said rotary shaft. The injection molding machine also includes a second motor for producing a force for advancing said screw in the injecting direction and retracting said screw, a screw shaft and a nut for converting the output torque of said second motor into linear movement, and a sliding member to which said nut is fixed. The motor control device includes a load detecting member fixed at one end to said holding member and at the other end to said sliding member, and a controller for controlling the operation of the first and second motors in accordance with the level of load detected by the load detecting member.

Abstract: A molding machine which performs molding by means of one mold part held by a fixed platen and the other mold part held by a movable platen movable toward and away from the one mold part. A shaft having an axis extending in the direction of reciprocal movement of the movable platen is disposed on a stationary frame for rotation with respect thereto and for reciprocal movement along the axis of the shaft, and is rotated by an electrical motor. First and second nut members are respectively screwed onto first and second threaded portions formed along the axis of the shaft. The first nut member is secured to one of the stationary frame and the movable platen while the second nut member is capable of being rigidly coupled with the other thereof via a clutch. While the shaft is being rotated, the second nut member is rigidly coupled with the other of the stationary frame and the movable platen via the clutch, a relative movement is produced between the shaft and the first and second nut members.