Improvement of the EDM Head for Dimensional Processing With an Arc on the Basis of a Desktop Drilling Machine With Manual Feeding of the Electrode-Tool
Authors:   Central Ukrainian National Technical University, Sergeev Anton , Bokov Viktor ,   Central Ukrainian National Technical University, Shmelov Vitaly ,   Central Ukrainian National Technical University
Published: December 2023

Currently, in mechanical engineering, the nomenclature of processed materials and the shape of processed products stimulate the use of various types of electrical processing of metals. The most common of them is electropulse treatment. The cost of a modern electric pulse machine is estimated at hundreds of thousands of dollars. In addition, this method of processing uses as an energy carrier an electric spark or an electric pulse that burns in the end interelectrode gap with pauses. During a pause, the part is not processed, therefore, the electropulse method of processing does not provide the maximum possible processing productivity. At the same time, the conditions of repair factories and workshops do not require high processing precision, but require cheaper equipment and high processing performance. A highly productive method of dimensional processing of metals with an electric arc is known. A well-known electroerosion head for dimensional treatment with an arc, created on the basis of a desktop machine. It has a manual axial feed of the electrode-tool from a gear shaft driven by a steering wheel, easy to manufacture, occupies a small area, does not require the modernization of the basic machine, and therefore does not require additional funds, is not expensive, and therefore can be used in repair factories and in workshops. However, when operating a known EDM head, the operator feels a great force on the handle of the steering wheel, which feeds the electrode-instrument. Moreover, the greater the difference between the outer diameter of the electrode holder and the diameter of the hole being stitched, the greater the effort the operator must overcome. This leads to a significant narrowing of the operational characteristics of the head. In addition, with frequent artificial short circuits related to the accuracy of the feed, the quality of processing deteriorates. That is why the use of the head in repair factories and workshops is limited. The purpose of the research is to improve the operational characteristics of the head and increase the quality indicators of processing due to the use of a self-braking transmission. The task of unloading is solved in the well-known electroerosion head of dimensional treatment with an arc on the basis of a table-top drilling machine with manual feeding of the electrode-tool due to the fact that a self-braking transmission, for example, a one-way worm, with a flywheel and a handle, is installed in place of the steering wheel of the gear shaft drive, and the head is supplied with an ammeter that measures the current strength during processing, and the ammeter is located in the field of view of the operator. A self-braking transmission is proposed as a control mechanism for the manual feeding of the electrode-tool for the EDM head of dimensional treatment with an arc based on a desktop drilling machine. It is shown that the use of such an EDM head allows to improve its operational characteristics by relieving the operator from axial forces during control and to increase the quality indicators of processing by reducing the number of short circuits and increasing control accuracy.