The Study Of Motion Control Mechanism Of Low Speed Wire-Electric Discharge Machining Tool

Low speed wire-electric discharge machining (LSWEDM) is a sort of precise manufacture technology used in the die industry and the manufacturing of aviation and astronavigation. With the development of the die industry and the manufacturing of aviation and astronavigation in our country, wire-electric discharge machining (WEDM) has been making progress. The idea of developing the LSWEDM machine tool, which has our own sciential property, has been recognized in the electro-discharge machining industry of our country. This dissertation summarizes the situation of the research of WEDM presently at home and aboard. Based on the research project of developing the CNC system of the LSWEDM machining tool, the thesis titled"The Study of Motion Control of Low Speed Wire-Electric Discharge Machining Tool"is put forward. Main research work are as follows:(1) The thesis analyses two type of typical configuration and reference frame of the LSWEDM machining tool. Based on the configuration of which the wire guiding rack is fixed and the Charmills OXYUVZ five-axis right-angle reference, the thesis analyses the motion of the machining platform and the wire guiding head when machining planar and three-dimensional workpiece.(2) The post processing of the CNC system has been designed, which can achieve decoding, wire radius compensation and coordinate conversion while machining taper. The ISO code achieved by manual or automatic programming can be disposed, and the result can transmit to the motion control card with the function of interpolation directly.(3) The thesis analyses and realizes the function of wire radius compensation (including discharging gap) of the LSWEDM machine tool. The author discusses the locus of the traveling wire at all kinds of transfer cases both in left tool offset (G41) and right tool offset (G42) in detail for the first time. The thesis brings forward corresponding examples for practical machining and the figure simulation, and the method of amending the offset radius while the wire leans has been explained.(4) Based on the motion analysis of the four-axis LSWEDM machine tool, an algorithm about how to control the four-axis motion is proposed, which is applicable both on the case of invariable taper and variational taper. The author expatiates the algorithm by deducing the motion locus of the machining platform and the wire guiding head according to the bottom surface locus of the workpiece and the taper angle,...