Study On Rotary EDM CNC System And Servo Control

Electric Discharge Machining (EDM) is a new type of nontraditional machining and has been developing for a few decades. Now EDM is heading towards high efficiency, high accuracy and intelligence. Generally, EDM can be simply classified into following varieties: shape EDM, hole EDM, wire EDM and rotary EDM, etc. The rotary EDM is used for machining super-hard conductive materials, such as polycrystalline diamond and ceramics, etc., especially for the cutting tool or mold fabrication.With the rapid development of science and technology, the urgent requirements for the hard-to-cut materials were proposed. The further research on rotary EDM all over the world is becoming natural. Therefore the main task of this paper is to develop a new NC system based on PC and a new servo control system for improvement of the present rotary EDM machine tool.In this paper, EDM theory was firstly analyzed according to the documentation mainly, and the mechanism of rotary EDM was then discussed. The effective factors of EDM process, electrode wear, machining accuracy and surface roughness have been studied. These works pave the way for setting up a new servo control system.In order to perform the machining process with higher efficiency and stability, a new NC system based on PC and a number of interface cards were established. These cards were based on PC ISA bus. Through these control cards, PC can connect CPU with external signals and exchange information easily. The new NC system developed by windows system can control the machining process automatically.Recognition of machining status for rotary EDM was analyzed and the different methods for servo control system were discussed. According to above works, a new servo control system was finally established. The experiments showed that the new servo control system was stable and reliable for machining and the control operation was convenient.Other control software finished by visual technology based on windows system and on using DLL in operation system for rotary EDM was also developed. Through all of these software, all machining processes were automatically controlled.