Special points and processing conditions of medium wire cutting machine

The middle thread cutting process is mainly used for mold manufacturing, and it has also been increasingly used in the processing of templates, cams, forming tools, precision small parts and special materials. EDM wire-cutting wire-cutting machine tools have their own particularities, and must also meet certain conditions during processing.
In the trial production of motors, electrical appliances and other products, some parts can be directly processed by the medium wire cutting machine, which saves the time for manufacturing stamping dies and shortens the trial production period. In addition to the basic features of wire EDM machining, EDM Wire-cutting machine tools have some other special features:
First, any two-dimensional surface with a straight line as a busbar can be machined without the need to make tool electrodes with complex shapes.
Second, it can cut slits of about 0.05 mm.
Third, not all redundant materials are processed into waste during processing, improving energy and material utilization.
Fourth, in the process of low-speed wire-cut WEDM machining where the electrode wire is not recycled, the electrode wire is continuously updated, which helps to improve the machining accuracy and reduce the surface roughness.
Fifth, the cutting efficiency that can be achieved in the wire removal is generally 20-60 mm2/min, up to 300 mm2/min; the machining accuracy is generally ±0.01-±0.02 mm, and the highest is ±0.004 mm; Roughness is generally Rα2.5 ~ 1.25 microns, up to Rα0.63 microns; cutting thickness is generally 40 ~ 60 mm, the maximum thickness of up to 800 mm.
The Chinese wire drawing technology pointed out that the following conditions must be met for the middle thread cutting to work properly:
First, there must be a certain gap between the molybdenum wire and the machined surface of the workpiece. The width of the gap depends on the processing conditions such as working voltage and processing volume. Secondly, when WEDM machining, it must be carried out in a liquid medium with certain insulating properties, such as kerosene, saponified oil, deionized water, etc. The requirement for high insulation is to facilitate the generation of pulsed spark discharges. The medium also has the effect of eliminating the electrolytic corrosion products and cooling electrodes in the gap. Molybdenum wire and the workpiece to maintain a certain gap between the surface, if the gap is too large, the voltage between the poles can not break through the inter-electrode media, you can not produce spark discharge; if the gap is too small, it is easy to form a short circuit connection, can not produce electricity Spark discharge. Third, pulsed power must be used, ie spark discharges must be pulsed and intermittent. During the pulse interval, the gap medium is deionized so that the next pulse can puncture the discharge between the two poles.