Research Of Low Wear And Energy Saving Die Sinking Edm Pulse Power Supply And Servo System

Electric discharge machining(EDM)is one of the most widely used nontraditional machining technologies.With no contact between workpiece and electrode,EDM has a great advantage over traditional machining.However,domestic EDM machine is still at a disadvantage of low utilization rate of electric energy,poor processing quality and so on.In this paper,the low wear and energy saving pulse power supply and it's servo system for EDM machining is designed.This paper presents an energy-saving method used in EDM machining which combines high voltage circuit of low energy to breakdown discharge channel with low voltage circuit to process material removal.The resistance applied to adjust current is eliminated and the energy utilization rate is considerably improved.The high voltage breakdown circuit as well as the high frequency transformer used in the full bridge inverter circuit is designed and calculated.MATLAB software is used to model and simulate the full bridge inverter circuit.The characteristics of different discharge waveforms in EDM are summarized,and a new lossless discharge waveform is proposed.The waveform mainly reduces electrode wear by decreasing current rising rate and improves the stability of discharge circuit by voltage step wave.The reduction of current rising rate is realized through the hindrance of inductance to the current,and the rate of the current rising is changed by altering the magnitude of inductance.The low loss circuit reduces the EDM electrode loss and improves the processing quality.A constant discharge energy EDM circuit is proposed.With STM32 embedded system utilized as the central control processor,JK trigger used to detect voltage breakdown signal and MOSFET as the switching component,the machining effect is significantly improved.The program used in the control circuit is compiled and debugged.MOSFET driving circuit is designed to ensure the quick and reliable opening and closing.Redundant circuit is studied to ensure the reliability of detection circuit.The schematic diagram of the control circuit is drawn,and the PCB diagram is designed and laid out to facilitate the installation and testing of power supply.The control scheme of EDM pulse power servo system based on PMAC Clipper movement card is put forward.The system takes PMAC multi-axis motion control card as the control unit and AC servo motor as the execution element.The requirements of servo system are analyzed and the gap voltage detection circuit is designed,PID control algorithm of servo system is applied and the control flow of the servo system is designed.Experimental processing is carried out with the assembled power supply.The influence of pulse width and peak current on machining is studied,and the machining effect is evaluated separately from material removal rate,surface roughness and relative electrode wear.The low wear machining circuit are verified and the experiment results are analyzed.