Research Into Computer Aided Wire-EDM CNC Programming System

Wire Electro-discharge Machining (WEDM) technology is widly used in manufacturing industry because of its minute cutting force and the ability to shape high hardness material, and it has played an important role especially in the field of mould manufacturing. Now in China, Wire Electro-discharge Maching with High traveling Speed (WEDM-HS) has been developed into a high level, and at the same time, the research on Wire Electro-discharge Machining with Low traveling Speed (WEDM-LS) is being further promoted. However, the performance of the CNC system inWEDM-HS is not fully satisfied, and there are still the obstacles between the CNC systems of WEDM-HS and WEDM-LS. On the other hand, the CNC software made in China for WEDM has defects of tech hysteresis and inconvenience, and the import software has poor universality and is hard to use. These conditions have greatly limited the further developement of WEDM technology in China, thus, the research on CNC software for WEDM is meaningful.Under the circumstances, we began the research on CNC software for WEDM by means of an Open Modular Architecture (OMA) conception. The research include almost all aspects of Computer Aided CNC Programing technology, such as the study of graph generation and editing, cutting track generation, CNC coding, file conversion and manufacture simulation et.al.In this dissertation, the framework and features of OMA CNC system has been discussed, and a structure of CNC software for WEDM with OMA conception has been presented. At the same time, we discussed the master plan of WEDM CNC programming system based on the Object Oriented Programming idea; studied the fitting method of planar curve, brought out an efficient and stable curve approximating method-near-equal-error biarc fitting; studied the planar translations of graphs and arc copulations between curves; discussed the offset strategy of cutting track, and brought about a noninterventional cutting track offset method according the defects of conventional algorism; studied the format of 3B and ISO code, and discussed theautomatically code generating algorism; studied the format of DXF files, and made a file converting module which use DXF as transition format; at last, discussed the simulation algorism based on the interpolating technology.Based on the above research works, developed a WEDM programming software-CAWEP, using C++language and MFC foundation classes. The CAWEP software employed interactive graphics automatic programming technology, and will run on PC and Windows platform.