Device and method for electrical discharge machining

Abstract

The electrical discharge machining device includes storage apparatus for storing the two-dimensional contour pass of the machined shape formed by the primary machining operation, the dimension of the taper of the side surface of the workpiece to be machined, the amounts of feed of the electrode in a given Z direction with respect to the movements of the electrode in the X and Y direction under respective machining conditions; information adding apparatus for adding offset information to the above-mentioned contour pass; machining operation number calculating apparatus, in accordance with a previously obtained machining depth per round about an electrode pass, for calculating the number of machining operations to be repeatedly executed around the electrode pass until a target depth is obtained; offset displacement amount calculating apparatus for calculating an offset displacement amount per round about the electrode pass in accordance with the length in the above-mentioned side surface direction of the side surface taper dimensions and the number of repeated machining operations; and, electrode position control apparatus, in accordance with an offset position added to the contour pass by the offset information adding apparatus, for controlling the offset displacement amount each time the electrode pass is machined.