Patent ID: 6433295
Filing Date: 2002-08-13
Classification: B23H

Abstract:
A method of electric discharge machining in which electric power for working is supplied between an electrode and a workpiece which is fixed onto a surface plate table arranged in a work tank in which work fluid is stored and the workpiece is worked by electric discharge, whereinwhen the surface roughness on a work face of the workpiece is more than a predetermined value, a bladder capable of expanding or contracting by the pressure of fluid filled in said bladder is contracted, and the work fluid is filled in a space between the working tank and the surface plate table and working is conducted on the workpiece; and when the surface roughness on a work face of the workpiece is not more than a predetermined value, said bladder is expanded, and a quantity of work fluid in the space between the work tank and the surface plate table is reduced and working is conducted on the workpiece.