In the middle of the 20th century, when the Lazarinkos of the Soviet Union studied the phenomenon and cause of corrosion damage to switch contacts by spark discharge, they discovered that the instantaneous high temperature of electric sparks could melt and oxidize local metals, thereby inventing and inventing electricity Spark machining methods, wire-cut electric discharge machines were also invented in the Soviet Union in 1960. At that time, I manually fed the work surface with a projector to view the front and back of the contour. In fact, I thought that although the processing speed was slow, it could process fine shapes that were not easily processed by traditional machinery. A representative practical example is the processing of special-shaped holes for chemical weaving nozzles. Mineral oil (lamp oil) for processing fluids used at the time. High insulation, small distance between poles, processing speed is lower than the current machinery, limited practicality.
NC-based, machine models processed in deionized water (close to distilled water) were first exhibited by the Swiss EDM plant at the Paris Machine Tool Exhibition 1969 to improve processing speed and establish safety in unmanned operation . However, the production of NC paper tape is very troublesome, and it will be a great burden on the user if automatic programming of a large computer is not used. Prior to the advent of inexpensive Automatic Programed Tools (APT), popularity was slow. Japanese manufacturers have developed wire-cut electrical discharge machining machines designed with a small computer automatic program, which is cheap and has accelerated its popularity. The machining shape of the WEDM is a two-dimensional contour. The automatic programming device widely uses simple APT (APT language is easier than formal models). The emergence of simple APT is an important factor in the development of wire cutting discharge machines.