Wire Cut Electrical Discharge Machining (WEDM)
The working principle is shown in the figure below. The electrode wire 1 wound on the wire transport cylinder 4 moves at a certain speed along the rotation direction of the wire transport cylinder, and the workpiece 3 installed on the machine tool workbench moves relative to the electrode wire according to the predetermined control trajectory by the workbench. One pole of the pulse power supply is connected to the workpiece, and the other pole is connected to the electrode wire.
There is always a certain discharge gap between the workpiece and the electrode wire, and the working liquid is sprayed. The spark discharge between the electrodes corrodes a certain gap, and the continuous pulse discharge cuts out the workpiece of the required shape and size.
The electrode wire of the low-speed wire cutting machine uses copper wire as the tool electrode, generally at a speed of less than 0.2m/s for one-way movement. The pulse voltage of 60~300V is applied between the copper wire and the processed materials such as copper, steel or superhard alloy, and the gap is maintained between 5~50um. The gap is filled with deionized water (close to distilled water) and other insulating media.
Make the spark discharge between the electrode and the processed material, and each other is consumed, corrosion, on the workpiece surface of the electrical corrosion of countless small pits, through the NC control monitoring and control, servo mechanism execution, so that the discharge phenomenon is uniform, so that the processing material is processed, so that it becomes the required size and shape precision of the product. At present, the precision can reach 0.001mm, and the surface quality is close to the grinding level.
Electrode wire discharge is no longer used, and the use of non-resistance anti-electrolytic power supply, generally with automatic wire threading and constant tension device. The work is stable, uniform, small jitter, high machining precision, good surface quality, but not suitable for processing large thickness of the workpiece. Because of the precision structure of the machine tool, high technical content, the machine tool price is high, so the use cost is high.
