Research On Super-large Thickness Machining Technology Of WEDM

A new super-large thickness cutting technology based on WEDM-HS has been studied in this thesis. Reasons that super-large thickness workpiece can not be processed even by employed WEDM-HS have been found out. These problems have been deeply analyzed. To overcome these problems, the WEDM super-large thickness tool has been ameliorated, and the related test and analysis has been designed and built up. During the process, a new type of electrode wire has been invented, and the primary type has been fabricated. Then some experiment results has been obtained and analyzed.In the first part of this paper, the essential theory and status quo of the super-large thickness cutting technology has been analyzed, mainly based on the processing mechanism and characteristics, and the actuality machining experience on the super-large thickness with WEDM technology in the world has been congregated. By summarizing the experience of predecessors on the area of cutting super-large thickness workpiece, it can be concluded that there are three basic reasons for the problem existing in the process as followed: (1) Discharge debris is difficult to be discharged in this super-large thickness cutting condition. For the slot processing area is too narrow while it is difficult to be enlarged; (2) Longer span wire electrode causes severe vibration; (3) Unsuitable processing parameters are key points that cause super-large thickness can not be cut. Based on these three fundamental problems, research has been carried on. And experiment conditions have been built up by actualizing a series of improvements on the existing tool, include designing the appropriate tension, following the installation of the moving-wire transducer, custom positioning of the wire, raising the adaptability between the wire guide group and wire reel group, designing the new filtration device for dielectrics fluid, and selecting high-performance and environmental friendly dielectrics fluid.Finally, a large number of experiments have been conducted to test the validity of these measures. The experiments mainly have been carried out in two aspects: the one is studying the processing parameters' impact on processing indicators under the super-large thickness, especially the machining speed. Through preliminary study, best processing parameters in the super-large thickness of the workpiece cutting have been obtained. The other is, to fulfil the actual industry requirements, a narrow groove has been successfully cut in a super-large thickness roller by this technology, and then the problem which bothered the enterprise for many years has been solved. And it also incarnated practical value of this research.This paper systematically studies the theory and practice of the super-large thickness workpiece cutting technology with WEDM. Some solutions for cutting super-large thickness workpiece have been put forward. And equipment have been redesigned and improved. A series of technologic experiments have been conducted. And the super-large thickness processing mechanism with WEDM has been studied. By this study, the cutting thickness of WEDM-HS has been largely improved and the preliminary cutting theory has been formed.