微细电火花加工机床关键技术

KEY TECHNOLOGIES OF MICRO EDM MACHINE TOOLS

研制开发两台高精度、高性能,具有自主知识产权的微细电火花加工机床,并对微细电火花加工机床的几个特有关键技术进行了深入研究。基于压电陶瓷的宏微伺服进给系统能实现分辨率为3.42nm的微进给,并且能实现振动式进给,以改善微细电火花加工的间隙状态,提高微细电火花的加工效率和加工质量。结合块电极反拷与线电极反拷的微细工具电极反拷系统,可高效高精度地现场制作微细电极,电极直径最小可达4μm。基于多传感器信息融合技术的放电间隙状态监测技术,能很好地解决微细电火花加工间隙状态的监测与识别问题。RC脉冲电源不存在维持电压现象,这一最新发现为降低单脉冲放电能量难题提供一个新的解决途径,使得基于RC方法开发的超微能脉冲电源的单脉冲放电能量最小降至皮焦级,为微细电火花加工奠定了良好的基础。最后的微细电火花加工试验表明,所开发的微细电火花加工机床性能稳定,且加工质量良好,尤其适合加工孔径为50～200μm的微细孔。

Two high-precision and high-performance micro electrical discharge machining （EDM） machine tools are designed and developed with independent intellectual property fight. Some key technologies about the micro EDM machine tool are deeply researched. A macro-micro servo control system based on piezoelectric ceramic can realize 3.42 nm displacement, and vibration feeding serve, which can greatly improve the gap state of micro EDM, and enhance the machining efficiency and quality. A reverse machining system for fabricating micro-electrode, which combined the block electrode reverse machining system and wire electrode discharge grinding （WEDG）, is able to make the microelectrode on-site, and the diameter of such an electrode can reach 4 μm. After that, the detecting circuit with a multiple-sensor fusion system for discharging process can solve the problem of gap state detection and identification for micro EDM process. No sparkle maintaining voltage exists during discharging of RC power supply. This discovery provides a new solution to solve the problem of decreasing single pulse energy. Thus the least single pulse energy based RC power supply of ultra-micro energy can be down to pico-joule, which is the basis of micro EDM. The last part shows that the implementation of these EDM machine tools verifies that the micro EDM can be performed stably, and can achieve the high operating quality. The micro EDM machine tool is especially suitable to process the hole whose aperture is around 50～200μm.