US 4,310,741 AGranted

Storage-capacitor-type EDM power supply

AssigneeInoue-Japax Research Incorporated

InventorKiyoshi Inoue

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Abstract

A storage-capacitor-type EDM power-supply system wherein the storage capacitor is charged from a DC source to store a predetermined amount of charge thereon under the control of a switch connected between the DC source and the capacitor. The discharge circuit connecting the capacitor with an EDM gap to allow the stored charge to be discharged through the latter also includes a switch which is controlledly rendered conductive by a signal pulse generator which provides a controlled switching signal preprogrammed in a microprocessor such that the capacitor discharge machining current has a predetermined waveform corresponding to the preprogrammed signal. Preferably, the machining current in each capacitor-discharge cycle is in the form of a composite pulse consisting of a series of periodically interrupted pulses of a minimum on-time and off-time.

Claims5

Dependent claims

A power-supply system for electrical discharge machining comprising:

a direct-current source connected in series with first and second switch means to a machining gap formed between a tool electrode and a workpiece;
a storage capacitor connected to said direct current source in parallel with said machining gap;
a charging circuit connecting said direct-current source to said capacitor and including said first switch means;
a discharging circuit connecting said capacitor to said machining gap and including said second switch means directly in series with said gap;
first pulsing means for controlledly turning on and off said first switch means to permit said capacitor to store a predetermined charge from said DC source;
and
second pulsing means for controlledly turning on and off said second switch means to permit said predetermined charge stored on said capacitor to be discharged directly through said machining gap to provide a discharge current therein of a predetermined waveform preset in said second pulsing means.

4 more elements

Dependencies are inferred from the claim text.