Research On Three-axis CNC Controlling EDM Milling Technology

Since the beginning of the 21 st century,nontraditional machining technology has developed rapidly.As an important machining direction in nontraditional machining,EDM milling technology has the advantages of the wide range of EDM molding process,freedom from material toughness,and other advantages.The production of complexly shaped electrodes is widely used in aerospace,medical devices,mold manufacturing and other fields.In EDM milling,pulse power and motion control systems are key to achieving high efficiency,high stability,and high-quality machining.This paper aims at the problems of serious energy consumption,low power utilization,unstable motion control system,and low control accuracy of traditional EDM pulse generators.Based on the three-axis linkage CNC machining machine,the pulsed power supply design,motion control system development,and related processing technologies were developed.The following research results were achieved.A new kind of variable voltage and current energy-saving pulse power supply is designed by comparing the advantages and disadvantages of various pulse power supplies.This pulse power supply adopts inductance to replace the current limiting resistance of conventional power supply,which greatly improves the energy efficiency.PWM pulse width modulation is used to control the timing of the power tube,and the output current is controlled by adjusting the duty ratio.On this basis,the combination of traditional pulse power supply can meet the requirements of rough,medium and fine.The overall design of the EDM milling CNC system was studied and designed.A gap discharge state detection circuit was designed to enable real-time detection and feedback of the discharge gap state.Based on the PMAC motion controller,the servo PLC program of the motion control system and the machine-related control system was programmed,and the precise servo motion control in the EDM process was realized based on the integral detached PID control algorithm.In addition,a human-computer interaction interface was developed based on Visual Basic 6.0,which included parameter setting,program editing,manual operation,serial port setting,real-time monitoring,and help.The communication between power control system and PMAC motion controller was realized,which caused real-time monitoring and control of EDM machining status.Based on the developed pulse power supply and PMAC motion controller,some EDM milling experiments were conducted,and the influence of different processing parameters on processing performance was discussed.The effects of processing parameters such as peak current,pulse width,inter pulse and electrode cross-sectional area on machining efficiency,electrode relative loss rate and surface quality were obtained.Finally,the summary and analysis were carried out.