Prevention of wire breakage during wire EDM-2nd report: grouping method of gap signals according to discharged location

摘要

In the 1st report{sup}1) we investigated about 3 gap monitoring signals: discharge voltage, ignitiondelay time and a radio signal just before wire breakage, in order to know which of them is the bestsignal to pre-monitor the wire breakage during wire EDM. Results showed that the discharge voltageis the best signal by which to pre-monitor the wire breakage. But other signals were not so clear.In the present report, we propose a new detecting method dividing these signals into groups accordingto discharged locations. This method clarify an abnormal gap state just before the wire breakage.Finally, we discuss a model of wire breakage that is able to explain obtained experimental results.