Research On Power Supply And Detection System For Electrochemical Micromachining (ecmm)

Electrochemical Micromachining (ECMM) is one of the most important studying areas in the field of micromachining. As a kind of Minuteness Proeessing without macro manufacturing stress or tool wire, it has gethered much attention around the world. The power supply and detection technology are key technologies for ECMM, it's performance has great influence on technic index of ECMM, so it's great significance to study it's key technologies.This research subject introduces the current domestic and overseas progress in ECMM and power supply of ECMM and detecting technology of ECMM, base on the analysis for ECMM principle and gap characteristics, a nanosecond pulse power supply and detection system was designed and made. The power supply adopt the scheme of direct power amplifier output, use the MCU and CPLD as the control center, meanwhile a fast discharge circuit was designed and the problem of waveform distortion has been solved. The power supply can provide the pulse width to 60ns and the output current of 100mA, the pulse width and duty cycle can adjust independently.According to the technology characteristics and gap characteristics for ECMM, the gap detection scheme was designed. The average detection circuit was designed, it changed the high-frequency pulse voltage signal in the gap into a average voltage signal, this signal was transmit to the computer after sampling by the MCU, and the computer judge the gap state by the average voltage. According to the comparison of MCU sampling results and the servo reference value, when short-circuit state appear the CPLD was cutoff, so the power supply is proted by software method.At last, test and technics experiment was done for the power supply and detection system. According to the actual output waveform by power supply, the characteristic of dual pulse output and the phenomenon of electromagnetic in high-frequency output was analysed. By the application of this nanosecond power supply, the experiment of Electrochemical Turning was carry out, and a micro-electrode of 20μm in diameter and 3000μm in length was fabricated; analyze the affection of the key parameters to the gap of the hole processing, and a micro hole of 100μm in diameter with good circle quality was fabricated on SUS304; a clear three-dimensional micro-structure of convex sets was fabricated by stratified milling with the end of tool electrode. Experiment result show that this nanosecond pulse power supply is valid to advance the maching precision and the performence of this power supply is capability and reliability.