气介质电火花修整金刚石砂轮机理及分析

摘要

For the inefficiency of traditional mechanical diamond dresser and environment pollution of liquid Electrical Discharge Machining (EDM ) , the existing precision mechanical wheel trimmer is improved .The mechanism of diamond wheel dressing by the gas medium spark is analysed ,the impact of polarity effect and the pulse width on the wheel is experimented .It is found ,by analyzing the morphology of the machined w heel surface ,that the positive polarity processing of EDM should be used in dressing diamond grinding wheel in gas .Short circuit and arcing phenomenon are reduced by using rotating disk electrode ,thus the stability of the dressing increases .In 20~500μs pulse width range ,the wheel surface melting phenomenon is obvious ,the erosion pits are larger with the increase of pulse width .%针对传统机械式金刚石砂轮修整的低效和液体介质电火花加工污染环境等问题，介绍了对现有精密机械式砂轮修整机的改造，分析了气介质下电火花修整金刚石砂轮的机理，对极性效应和脉冲宽度对砂轮修整的影响进行了实验。通过分析被加工砂轮表面的形貌发现，气介质下电火花修整金刚石砂轮宜采用正极性加工，盘状电极的使用克服了加工过程的短路、拉弧的现象，提高了修整的稳定性。在20～500μs的脉冲宽度范围内，随着脉冲宽度的不断加大，砂轮表面结合剂熔融现象越来越明显，蚀除的凹坑也越大。