Patent ID: 6469522
Filing Date: 2002-10-22
Classification: B23H

Abstract:
An electrical discharge state detecting device for an electrical discharge machine, comprising:high-frequency component detecting means for detecting a high-frequency component superimposed on either an electrical discharge voltage or an electrical discharge current at a machining clearance between an electrode and a workpiece; rectifying means for outputting a rectified component obtained by rectifying said high-frequency component detected by said high-frequency component detecting means; first integrating means for integrating, over time, said rectified component outputted from said rectifying means; reference voltage output means for outputting a reference voltage; second integrating means for integrating, over time, said reference voltage outputted from said reference voltage output means; integration stopping means for stopping integrations in said first integrating means and said second integrating means only for a predetermined time on the basis of an operation of an internal switching element for use in current controlling of a machining power source; time changing means for changing a duration of said predetermined time, for stopping the integration in said integrating stopping means, in accordance with a magnitude of a machining current value; control means for controlling a starting and an ending of the integrations in said first integrating means and said second integrating means; and comparing means for comparing an integrated value obtained by said first integrating means with an integrated value obtained by said second integrating means.