Brother Kogyo Kabushiki-Kaisha

Akihiro Komori

Makoto Goto

Kunio Kohsaka

Yuji Ishibashi

Takao Okabe

Hisao Hachisuka

A discharge frequency per unit time between a wire electrode and a workpiece is detected, and the thickness of the workpiece is estimated on the basis of the discharge frequency, the relative moving speed between the wire electrode and the workpiece and the information on the shape of the workpiece. Thereafter, the optimum discharge period is calculated on the basis of the estimated thickness of the workpiece and the set processing conditions to perform the processing of the workpiece.

Wire electric discharge machine having alterable discharge period

In a wire electric discharge machine, a permissible discharge frequency is calculated on the basis of an average discharge frequency per unit time which is estimated on the basis of a target inter-electrode voltage or a detected average inter-electrode voltage and a discharge period. The number of times a discharge is actually induced between a wire electrode and a workpiece every unit time is counted and the application of a pulse-shaped voltage is ceased for a residual time of the unit time by a control device when the discharge frequency exceeds the permissible discharge frequency.

Wire electric discharge machine having function for counting number of

An electrical discharge machining power supply unit which detects fluctuations in the voltage of a DC power source (3) and sends a signal to an A/D converter (5) and has a microprocessing unit (8) to change the on-time of a transistor switching element (12) in inverse proportion to the rate of voltage fluctuations computed by the microprocessing unit (8), thereby maintaining the voltage supplied across the electrode (1) and workpiece (2). In a second embodiment a pilot power supply and a current detecting element for detecting a dielectric breakdown of the gap is used.

Power supply unit for electrical discharge machine

An electric discharge machine has a CPU that controls a switching element that supplies a pulse voltage to the gap between an electrode (which may be a wire electrode) and a workpiece. The CPU is able to determine the average pre-discharge time (the average time between the turning on of the switching element and the start of each electrical discharge) based on the sampling time interval and the counted number of discharges that occurred during the sampling time interval, by turning off the switching element at a set time after the start of each electrical discharge, and turning the switching element on again after a longer set time has elapsed from the start of each electrical discharge. The average gap voltage and average gap current are then calculated and displayed from this data. The feeding of the electrode and the workpiece relative to each other is controlled to reduce the difference between the counted number of discharges that occurred during the sampling time interval and a calculated desired number of discharges.

Growing community of inventors

Nagoya, Japan

Akihiro Komori