Condition Monitoring in Concurrent Micro-hole Electrical Discharge Machining with Electrode Feeding Devices Employing AZARASHI (Seal) Mechanism

This paper deals with condition monitoring of electrical discharge machining (EDM) with two electrode feeding devices. An electrode feeding device for micro-hole electrical discharge machining by using AZARASHI (Seal) mechanism has been proposed. The conditions of the gap between a tool electrode and workpiece were classified into 6 states based on the gap voltage and current: (a) open-circuit, (b) charge, (c) normal discharge, (d) continuous arc, (e) abnormal discharge and (f) short-circuit. In addition, the transitions among them were clarified. The machining performance in the case of using a single electrode was compared with that in the case of using two electrodes. The machining time in both cases was the same because the number of the normal discharge was almost the same.