Patent ID: 7175756
Filing Date: 2007-02-13
Classification: B23H

Abstract:
1. A device for treating working fluid for electric discharge machining, in which a workpiece is machined by applying electric voltage between an electrode and the workpiece to generate electric discharge between the electrode and the workpiece, said device comprising a polluted fluid tank for collecting and storing the polluted working fluid used in the machining, a cleaned fluid tank for storing cleaned working fluid obtained by delivering the polluted working fluid from said polluted fluid tank to a filter device by means of a filter device pump and filtering the polluted working fluid, a working fluid supply pump for supplying the cleaned working fluid from said cleaned fluid tank to an electric discharge machining area during the machining, and a pump controller for controlling a discharge rate of said filter device pump, wherein said device further comprises fluid level detecting means for detecting a fluid level of the cleaned working fluid in said cleaned fluid tank, and a control unit for determining a discharge rate command for the filter device pump, based on the fluid level detected by said fluid level detecting means, said control unit outputting the determined discharge rate command to said pump controller, said pump controller controlling said filter device pump, based on the discharge rate command, to transfer the working fluid from said polluted fluid tank to said cleaned fluid tank through said filter device.