The electric spark punching machine is different from the wire cutting machine and the forming machine in that the electrode of the electric pulse is a hollow copper rod, and the medium passes through the fine hole in the middle of the hole of the copper rod to perform cooling and chip evacuation. It relies on the discharge between the electrode and the metal to produce high temperature corrosion metal to achieve the purpose of perforation. Therefore, the tool electrode used in the machining of the EDM is quite suitable for the forming tool used for machining, which directly affects the dimensional accuracy and geometry of the machining. It is the basis of processing, there is no good electrode, other conditions are better, and no good hole shape can be processed. Therefore, the electrode occupies an extremely important position in the machining of the EDM machine. A good electrode must meet the following requirements. :
1, material
Commonly used electrode materials for machining small holes in EDM machines are brass tubes and copper tubes. The commonly used capillary size (outer diameter) is 0.2-4 mm. Brass tubes are recommended for the processing of small holes in general materials, and copper tubes are recommended for machining holes of cemented carbide.
2, performance
(1) The linearity of the electrode should be good, and the dimensional accuracy should be uniform;
(2) The electrode material has stable performance and will not be deformed by discharge or processing;
(3) It has a certain rigidity (elasticity) and can withstand a certain external force. It can be quickly restored to its original shape after being deformed by external force. The electrode of the EDM micro-hole is a micro-capillary tube, and it is impossible to apply an external force. put;
(4) The capillary hole is smooth and unobstructed, and the thickness of the tube wall is uniform;
(5) The end face of the capillary is cut by wire cutting or electric discharge machining, and the surface roughness of the machined surface is not lower than Ra l.6.
The electric spark punching machine is widely used in the processing of small holes, and it is suitable for processing various difficult materials. It can be used to process general mechanical drilling and deep hole machining problems that cannot be solved by general EDM. It can realize the efficient processing of fine deep and small holes, and it is applied more and more in industrial production.
