The difference between EDM drilling machine, EDM wire cut machine, and EDM die sinking machine is that the electrode of the electric pulse is a hollow copper rod, and the medium passes through the small hole in the middle of the copper rod hole to perform cooling and chip removal (EDM driller). It relies on the discharge between the electrode and the metal to produce high temperature corrosion of the metal to achieve the purpose of perforation.
Therefore, the electrode used in EDM small hole drilling machine is equivalent to the forming tool used in processing, which directly affects the dimensional accuracy and geometric shape of the processing.
It is the basis of processing. Without a good electrode, no matter how good other conditions are, a good hole shape cannot be processed. Therefore, the electrode occupies an extremely important position in the machining of EDM drillers.
A good electrode must meet the following requirements :
1. Material
The commonly used electrode materials for small holes drilling machine are brass tube and copper tube. The commonly used capillary size (outer diameter) is 0.2-4mm. It is recommended to use brass tubes for processing general materials, and copper tubes for processing hard alloy holes.
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 electric discharge or processing.
(3) It has a certain rigidity (elasticity) and can withstand a certain external force. After being deformed by the external force, it can quickly return to its original state. The electrode of the EDM small hole driller is a micro tube, which cannot be applied with external force, so it is required to be handled gently.
(4) The tube’s hole is smooth and unobstructed, and the thickness of the tube wall is uniform.
(5) The end surface of the tube is cut by wire cutting or EDM die sinker, and the surface roughness is not less than Ra 1.6.
The EDM driller is widely used in small hole processing, and it is suitable for processing various difficult-to-machine materials. It can be used to process general mechanical drilling and deep small hole processing problems that cannot be solved by other EDM machine, and can realize the efficient processing of micro and deep small holes, and it is more and more used in industrial production.
