Improvement of the EDM Head for DIMENSIONAL Treatment of Rods with an Arc on the Basis of a Desktop Drilling Machine
Authors:   Central Ukrainian National Technical University, Serheiev Anton , Bokov Viktor ,   Central Ukrainian National Technical University, Shmelov Vitaly ,   Central Ukrainian National Technical University
Published: January 2025

Modern enterprises use various equipment for the production of rods, for example, hydraulic presses for direct extrusion and metal cutting machines. However, this equipment is not used for the production of rods from hard-to-process materials. In this regard, EDM machines are of some practical interest, as they are more universal and reliable.
Electroerosion machines that can be used for the manufacture of rods include electric spark machines, electric pulse machines and machines for dimensional processing by electric arc (ROD - dimensional processing by arc). It is shown that the most productive machines are those implementing the ROD method. However, known machines for ROD rods have a high cost and occupy a large area, and therefore cannot be applied in repair factories and workshops.
There are well-known electroerosion heads for dimensional treatment with an arc for metal-cutting equipment. They have a low cost and occupy a small area, but do not provide high-quality and accurate processing of rods. This is due to the fact that the working fluid together with erosion products moves in the end interelectrode gap in the direction from the periphery to the center of the electrode-tool - reverse pumping. As a result of this, the lateral interelectrode gap in the direction of the liquid flow continuously increases, the lateral surface of the rod is shaped like a cone, and its roughness increases.
A well-known electroerosion head for dimensional processing with an arc based on a desktop drilling machine. When processing rods, it is adjusted from reverse to direct pumping, in which the working fluid in the end interelectrode gap moves in the direction from the center to the periphery of the electrode-tool. As a result of the fact that the erosion products do not fall into the lateral interelectrode gap, the rod is formed in a cylindrical shape, and the roughness of the treated side surface is noticeably reduced. However, during operation of the known EDM head, the erosion products are not removed from the sealed chamber, but accumulate in it. The latter is due to the fact that the level of intake of the working fluid together with the erosion products in the sealed chamber of the head is much higher than the level of the end interelectrode gap and the erosion products must move upwards. Since there is no hydrodynamic component of upward movement of the particle in the hermetic chamber, after processing each rod, the operator must clean the chamber from erosion products, which is very inconvenient and time-consuming.
The purpose of the study is to improve the operational characteristics of the EDM head during ROD of rods due to the creation of conditions for the removal of erosion products from the processing zone.
The proposed new EDM head for dimensional treatment of rod arcs on the basis of a table-top drilling machine is supplied with a backing plate through which the working fluid, together with the erosion products, are removed from the treatment zone. Under the influence of gravity, erosion products (metal powder) fall down, and through a channel in which the flow rate is sufficient, are completely removed from the head to the filter, and the purified working fluid is returned to the tank. It is shown that the use of such a head improves operational characteristics and allows the removal of erosion products from the processing area without the use of manual labor.