Research On Micro Wire Electrical Discharge Machining Pulse Generator Based On Ultrosonic Modulation

With the development of manufacturing, machining precision and efficiency ismore and more important for wire electrical discharge machining. To provide tinydischarge energy of single pulse is necessary to micro wire electrical dischargemachining (MWEDM) pulse generator. Pulse duration and open circuit voltage isthe key factors that affecting single discharge energy. It is proved by the theory andpractice that both reduce pulse width and reduce open circuit voltage can effectivelyreduce the discharge energy of single pulse. How to obtain tiny discharge energy ofsingle pulse is researched.First, development of MWEDM pulse power is described, then characteristicsof the low circuit voltage MWEDM is analyzed, advantage is can be obtainedsmaller discharge energy of single pulse and contribute to improve the machiningaccuracy. But small discharge gap that produced by low circuit voltage MWEDMcause discharge debris exhaust difficult, that limit the application of low circuitvoltage MWEDM. Today, closely integrated of interdisciplinary that provides a newidea to solve the problems by combined with ultrasonic. Discharge debris andbubble which generated during processing can be exhausted easily by usingultrasonic. This paper promote the discharge debris exhausted by reference toultrasonic, and achieve the purpose of reducing effective discharge pulse duration ofsingle pulse by ultrasonic modulation.This paper use DSP and CPLD as the control core. Frequency tracking ofultrasonic generator is realized by DSP, frequency tracking is achieved by detectingthe phase difference between the voltage and current of transducer; Ultrasonicmodulation is realized by CPLD, that control pulse generator generate pulse signalby ultrasonic signal.At last, this paper design processing experiments used MWEDM pulsegenerator by ultrasonic modulation, and compared with single wire electricaldischarge machining. Experimental results show that ultrasonic can promote exhaustdischarge debris in low open circuit voltage machining and reduce the short pulse.Reducing effective discharge pulse duration of single pulse is achieved by ultrasonicmodulation.