Three-Dimensional Controlled EDM Using Column-Shaped Electrode (1st Report)

Changing Process of Electrode Shape on Ditch Forming

Abstract

Introducing the computer technology, three-dimensional controlled EDM using simple-shaped electrode is put to practical use. This paper describes some basic researches on this method. There are more complicated problems on the three-dimensional controlled EDM than the one-dimensional method. And in order to develop the former method and to extend the area of application, it is important to grasp the basic machining characteristics, especially the changing process of the electrode shape. In this research an equipment on a trial basis of the three-dimensional controlled EDM, including a measure-compensating mechanism for the electrode wear length, is made, and some experiments are performed to form straight ditch using column-shaped electrodes. And the changing process of the cross sectional shapes of the ditches, exactly the shapes of the electrodes is considered. From the results of these experiments the following became clear mainly that the wear is progressed linearly in the radial direction in each part of the electrode, and that the process can be supposed on ditch forming with repeated several notchings.