NUMERICAL CONTROL METHOD AND APPARATUS FOR ELECTRIC-DISCHARGE MACHINING.

摘要

When retracting an electric-discharge machining electrode because the distance between the electrode and a workpiece has become smaller than a predetermined value, the electrode is retracted at a speed with a high magnification (f x M2) for a predetermined period of time set by a timer (302) from the time at which a retraction signal is generated. and is then retracted at a speed with a low magnification (f x M1). When switching over from retraction to advance. advance speeds are similarly changed over from one to another by means of a timer (305). By thus applying a drive signal of a high magnification for a short period of time from the point at which the oirection in which the electrode is moving changes, the response of the electrode movement control is improved, so that is is possible to prevent collisions between the electrode and the workpiece, it is also possible to eliminate unnecessary wasteful movements of the electrode.