Abstract
This report describes a three-dimensionally and numerically controlled electric discharge machining (EDM) system which is newly developed in order to solve a serious problem of the tool electrode wear in the contouring EDM. In order to obtain higher accuracy in machining this system comprizes faculties of both accurate monitoring of the deforming process of the electrode due to wear and automatic compensation of tool path. Shapes of the tool electrode are standardized into a cylindrical form and the constant rotation is given to the electrode to make the electrode wear axis-symmetric for facilities of the measurement. The shape of the worn electrode is measured periodically during machining process by using automatic touch-sensing mechanism, and proper compensation is given to the tool path in each time. Main results are as follows : (1) Various contours including corners are formed with high accuracy, and spherical contours are also obtained only by changing the machining programs. (2) By utilizing the deformed shapes of the worn electrodes smoothed surfaces as well as corners with small radius are obtained. (3) The deformation process of the electrodes is clarified.
