Research On The Process Of High Low Double Speed WEDM

Nowadays, for some inherent defects and shortcomings, the cutting efficiency and cutting accuracy of the High Speed Wire-cut Electrical Discharge Machining (HSWEDM) with Chinese characteristics have been in a relatively low level for a long time, compared with Low Speed Wire-cut Electrical Discharge Machining (LSWEDM) abroad. Therefore, technological gap in cutting efficiency and cutting accuracy between HSWEDM and LSWEDM is seriously increasing and urgently requires a rapid development of the high-efficient, high-accuracy and low-cost technology of WEDM which should not just has chinese own intellectual property rights, but also take into account of the current industrial condition. In this dissertation, the High Low Double Speed WEDM that systematically combined the HSWEDM and the LSWEDM was presented through careful analysis of the machining characteristics of the HSWEDM and the LSWEDM. By adopting a reciprocating high traveling speed of wire-electrode in the first cutting and a one-way low traveling speed of wire-electrode in the subsequent multi-cutting, the High Low Double Speed WEDM works more precisely than the HSWEDM and more economically than the LSWEDM. In a consideration of lifting the High Low Double Speed WEDM to the level of the medium-grade LSWEDM, some research into the process of High Low Double Speed WEDM was done, including high efficiency of the HSWEDM, single cutting and multi-cutting of the LSWEDM, blanking cutting and compound machining of the HSWEDM and the LSWEDM. The main work and conclusions in this paper are presented as follows:(1) According to the design requirement and objective, both schematic drawing and realization of the High Low Double Speed WEDM were introduced and the experimental system was established.(2) Two kinds of basic gap flows, pressure-gradient flow and shear flow, were studied in terms of their influence on the inter-electrode flow field of the WEDM, the computational model of which was established and simplified with FLUENT, professional fluent software in a finite element manner. The effects of a variety of spraying pressure, wire-electrode traveling speed and discharge gap on inter-electrode flow field were also investigated.(3) The mechanism of high-efficient cutting of high traveling speed wire-electrode with high energy discharging was analyzed. Numerical simulation of inter-electrode flow was conducted and proved by experimental result which showed that the compositing pressure-gradient flow and shear flow highly favors improving inter-electrode flow by diminishing burned-area across the processed surface and by increasing cutting efficiency. (4) The conventional electrical and non-electrical parameters were studied in a relation with their influences on the cutting efficiency of the HSWEDM that involves high energy and composited cooling liquid.(5) The technological rules of the LSWEDM based on composited cooling liquid were studied, including machining accuracy of one cutting, surface roughness of multi-cutting, blanking cutting and so forth.(6)By combining the HSWEDM and the LSWEDM, a technological comparison between the High Low Double Speed WEDM and multi-cutting of the HSWEDM was presented, focusing on the influences exerted by these two types of process on the cutting accuracy and surface roughness.