Mitsubishi Denki Kabushiki Kaisha

Hiroyuki Ooguro

Seiji Satou

Takashi Hashimoto

Akihiko Iwata

Akihiro Suzuki

Hisashi Yamada

Yoshikazu Tsunoda

Yoshikazu Ukai

Taichirou Tamida

Naka Sakakida

A power supply apparatus for an electric discharge machine configured to perform melt-removal on a workpiece by supplying pulse-like power to a machining gap between an electrode () and a workpiece (). This power supply apparatus includes a second machining circuit configured to control a voltage to be applied to the machining gap and to cause a discharge in the machining gap, a first machining circuit adapted to operate to supply, when a discharge occurring in the machining gap in response to application of a voltage by the second machining circuit is detected in a first drive mode, a constant current to the machining gap, and also configured to operate to adapt a voltage source () in the second machining circuit to output a constant voltage in a second drive mode, and connection means () configured to close connection to a power supply () to supply electric power through the second machining circuit in the first mode and also configured to open the connection to the power supply () in the second mode so that the second machining circuit operates at a constant voltage supplied from the voltage source ().

Power supply apparatus for electric discharge machine and power supply control method

A power supply device for electric discharge machining includes a switching circuit that supplies a discharge pulse current to an inter-electrode portion that is a portion between an electrode and a workpiece serving as another electrode arranged to be opposed to the electrode at a predetermined interval; and a pulse-width control unit that generates a control pulse signal of a predetermined pulse width in response to a detection signal for starting a discharge at the inter-electrode portion. The switching circuit includes a switching circuit including a switching element suitable for a high-speed operation and a switching circuit including a switching element suitable for a low-speed operation, and receives the control pulse signal in parallel.

Discharge-processing power source device

Machining electrical power supply device for wire electrical discharge machining. Includes an electrical discharge state distinguishing circuit () for distinguishing at least two inter-electrode states, including electrical shorting and normal electrical discharge, between a wire electrode (E) and a workpiece (W), and an inter-electrode current waveform control means for supplying, and for switching between supply of, a triangular wave and a trapezoidal wave current to the electrodes. According to the inter-electrode state distinguished by the electrical discharge state distinguishing circuit (), in cases where the inter-electrode state is that of electrical shorting (Y), the inter-electrode current waveform control means supplies a triangular wave current (I) to the electrodes, and in cases where the inter-electrode state is that of normal electrical discharge (Y), it supplies a trapezoidal wave current (I) to the electrodes. Breakage of the wire electrode (E) can be avoided and machining speed can be improved.

Machining power supply for wire electrical discharge machine

Charge accumulated in a capacitor is used to provide a processing current flow between a target and an electrode. When a diode is turned on, a first dc power supply is used to provide the processing current flow between the target and the electrode. In this state, after a lapse of a predetermined time, the current supply using the first dc power supply is stopped, and an induced electromotive voltage, induced by two floating reactors, is used to rapidly drop the processing current flowing between the target and the electrode, while charging the capacitor.

Growing community of inventors

Tokyo, Japan

Hiroyuki Ooguro