Kabushiki Kaisha Kobe Seiko Sho

Noriharu Nakagawa

Masanobu Kurumaji

Hiroaki Kondo

Hiroshi Ueda

Naoki Takeuchi

Tsutomu Sano

Koichi Fukushima

Kazuyuki Kajiyama

Tutomu Sano

Toshiaki Akita

Etujiro Imanishi

Yoshihiro Fukuda

Nobuo Kimura

Kazuyuki Kijayama

Hiroyuki Kuwano

Satoshi Hirota

A method of controlling a hydraulic press wherein changing over from velocity control to pressure control can be effected at an optimum point of time in accordance with a condition of material being filled. When a movable mold half of a metal mold is moved by a hydraulic cylinder to compression mold a work within a cavity defined in the metal mold, the velocity of movement of the mold half by the hydraulic cylinder is controlled until pressurization of the work is started, but after starting of the pressurization, the pressurizing force of the hydraulic cylinder is controlled. During the velocity control, a parameter which varies as the compression proceeds is successively detected during the velocity control, and changing over from the velocity control to the pressure control is effected at a point of time when the detected parameter coincides with a preset value--that is, when the work is fully filled in the cavity. A device for controlling a hydraulic press is also disclosed wherein optimal pressure control can be assured in accordance with a current condition of material for molding.

Method of controlling hydraulic press

A press working control method for controlling the press working operation of a press having a pressure cylinder for applying a working pressure to a workpiece, a press slide operatively connected to the pressure cylinder and carrying a movable die, a bed fixedly mounted with a fixed die, a plurality of control cylinders supporting the press slide in a level position during the press working operation, and a press control system for carrying out the press working control method. The press control system comprises a first pressure detector for detecting the operative pressure of the pressure cylinder, quick-response control valves each for regulating the height of the control cylinder, height detectors each for detecting the height of the control cylinder, second pressure detectors each for detecting the operative pressure of the control cylinder, servovalves each for detecting the operative pressure of the control cylinder, and a control unit including a computer for deciding manipulated variables for the height and operative pressure control of the control cylinders on the basis of data obtained by the detectors. The respective heights of the control cylinders are regulated individually so that the press slide is maintained in a level position during the press working operation, while the respective operative pressure of the control cylinders are regulated so that a desired working pressure is applied to the workpiece.

Press control for maintaining a level position and a uniform pressure on

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Neyagawa, Japan

Noriharu Nakagawa