Fanuc Corporation

Nobuaki Hashimoto

Motohiro Nagaya

Tatsuya Kawasaki

Koichi Nishimura

Mitsushi Yoshioka

Shingo Okada

Shingo Fanuc Okada

A fall-prevention leg portion is provided projecting rearward from the central bottom portion of a stationary platen. This leg portion is formed with a pin hole, which receives a pivot pin that fixes the stationary platen for angular motion around a vertical axis, and bolt holes, which receive tilt adjusting bolts for adjusting a longitudinal tilt of a mold mounting surface of the stationary platen with respect to the vertical axis. The parallelism between the stationary platen and the movable platen can be easily adjusted by regulating the angular motion of the stationary platen around the pivot pin and the longitudinal tilt of the stationary platen by the adjusting bolts.

Mold clamping mechanism for injection molding machine

A nozzle touch mechanism which does not allow an injection unit to move back by the force of inertia at the time of acceleration of injection and prevents leakage of the molten resin. A damper is arranged between the injection unit and a stationary platen secured to a base, so as to generate a strong braking force only at the time of high acceleration of the injection unit. A ball screw is rotated by driving an electric motor to move forward a nut member screwed onto the ball screw, whereby the injection unit is moved via a spring. When the injection unit is stopped by contacting a nozzle to a metal mold, the spring is contracted. When the amount of contraction of the spring reaches a predetermined value, the motor is stopped and locked such that the nozzle touch force corresponding to the amount of contraction of the spring is generated. Even though the injection unit undergoes the force working to move back the unit due to the inertia force at the time of acceleration of the injection, the injection unit is not moved back because the damper substantially prevents the movement back of the unit and the leakage of molten resin.

Nozzle touch mechanism

A connecting member is formed by an upper plate portion and a side plate portion. One end of the upper plate portion is fixed to a fixed platen of an injection molding machine, and a lower end of the side plate portion is fixed to a base frame to which the fixed platen is fixed. This connecting member prevents the fixed platen from being tilted when a nozzle touch force is applied from an injection apparatus.

Injection molding machine

A system for controlling nozzle touch force, which is capable of maintaining the touch force relying upon a simple constitution. An electric motor moves the injection unit forward via a spring to bring a nozzle into contact with a metal mold. Further, the spring is compressed to impart a preset nozzle touch force. In the injection/pressure-maintaining step, the screw is driven, and a position/speed detector provided on a servo motor for injecting the resin detects the injection speed at regular intervals. A force produced by the force of inertia of the moving portions such as the injection screw and the pusher plate that move due to the injection operation, is found from the acceleration that is found from the injection speed. The amount of compression of the spring is controlled by varying the rotational position of the motor by an amount corresponding to the force that is found to maintain the nozzle touch force constant. Since the nozzle touch force is maintained constant, no resin leaks and an excess of nozzle touch force is not produced, either.

Growing community of inventors

Yamanashi, Japan

Nobuaki Hashimoto