Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki K.k.

Morihisa Nishikawa

Yoshio Ozaki

Yoshihide Kinbara

Atsushi Taneda

Toshiaki Tanaka

Masahiro Nakata

Kooji Akamatsu

A waveform control device for an electrical discharge machine apparatus which supplies current pulses to the gap between an electrode and a workpiece for machining of the workpiece. A first D.C. source, which supplies at least a part of a voltage that is applied across the gap, is connected in parallel with first and second circuits comprising a series connection of a switch and a diode. Connected between a first and second series circuit is a switched conductive circuit which, together with an auxiliary D.C. source, maintains the current flow at a base current level. Control of operation of the switches in the first and second circuits permit a controlled discharge of current across the gap while permitting the output voltage to be clamped at a safe level. A plurality of inductive circuits may be used to provide selectivity, where the inductances are different and to provide further control of the discharge current shape. A variable inductance, whose value is proportional to the output peak current, may be used to control current ripple.

Waveform control device for electrical discharge machining apparatus

Electric discharge machining method and device

Growing community of inventors

Aichi, Japan

Morihisa Nishikawa