Development Of Pulse Power Supply For Multifunctional Discharge Milling

Discharge milling technology as an important method of special processing technology can realize high efficient and high quality processing effect for a variety of high hardness,high strength and high brittleness,high viscosity and high purity characteristics of new materials and a variety of complex cavity structure and special technical requirements of parts.This technology has been used more and more widely in the territories of electronics,precision machinery,mold manufacturing,defense industry and aerospace and so on.Pulse power supply is an important equipment of electric discharge milling machine tool,which output electrical characteristics are directly related to the processing efficiency size,energy loss and the machining surface quality.In recent years,with the rapid development of power electronic technology,electric discharge milling pulse power is continuously upgraded toward to a more functional,integration,intelligence,high frequency and high efficiency low energy consumption direction,in order to better meet the demand of electric discharge milling process.This paper introduces the application and development trend of electric discharge milling technology,combined with pulse power research present situation and technological achievements at home and abroad,emphasize the feasibility and necessity of the multi-function electric discharge milling design to used in short arc milling machining,electrochemical milling maching and micro-electro milling machining.Combining with the short arc milling,edm milling and micro milling technology requirements and their research of processing pulse power output characteristics,put forward the overall design requirements about multi-mode discharge milling pulse power supply.In this paper,the pulse power supply takes the DSP as the core,and there are three kinds of processing modes which can be arbitrarily switched to control stably,and main circuit structure is combined by DC/DC whole bridge inverter and chopper converters.In order to meet the output voltage amplitude requirements under different processing modes,the vice edge output circuit topology structure of the high frequency transformer is controlled by three independent parallel output circuit,and the former vice edge has its own turn ratio.According to the different work requirements ot level before and after the circuit,choose SG3525 A,CPLD pulse generating chip respectively,in order to provide drive pulse signal driver circuit for the front power switch tube IGBT and the backward stage MOSEFFT drive circuit,and finally the pulse power supply can realize the adjustable control of output pulse voltage amplitude,duty cycle and frequency.To protect the surface quality under the three milling mode processing,we design the different circuit for circuit and gap state detection circuit,and analyze the power source of electromagnetic interference,electromagnetic interference suppression measures are put forward to improve the stability of their own power.In this paper,the short arc milling,edm and electrochemical discharge control parameters in the system are analyzed,in order to further improve the level of intelligent control of pulse power supply,in the design of controlling system software,we use the two kinds of control algorithm,fuzzy control and neural network for pulse power electric parameters online and offline selected control scheme of the electrical parameters,greatly improving the machining surface quality.