Збірники наукових праць ЦНТУ
Permanent URI for this communityhttps://dspace.kntu.kr.ua/handle/123456789/1
Browse
7 results
Search Results
Item Удосконалення процесу обробки тіл обертання електричною дугою(ЦНТУ, 2020) Боков, В. М.; Сіса, О. Ф.; Юр’єв, В. В.; Bokov, V.; Sisa, O.; Yuryev, V.; Сиса, О. Ф.; Юрьев, В. В.Запропоновано та досліджено високопродуктивний спосіб розмірної обробки тіл обертання електричною дугою в гідродинамічному потоці робочої рідини та пристрій для його реалізації, що покращують умови праці оператора за рахунок усунення ефекту розбризкування робочої рідини та усунення світлового ефекту від горіння дуги в зоні обробки, а також підвищують довговічність роботи електродотримача. In modern mechanical engineering, electrical discharge machining (EDM) methods are widely used for machining bodies of rotation from difficult-to-machine materials. Those methods ensure sparing cutting and make it possible to machine any electrically conductive material irrespective of its physical and chemical properties, in particular hardness. There is a known method for dimensional machining of bodies of rotation with electric arc using a wire electrode tool that is pulled along in the machining area thus "compensating" for that tool's EDM wear and tear. The machining accuracy is therefore significantly heightened. However, when implementing this method, an effect of splashing the working fluid outside the working area of the machine and a pronounced luminous effect from the burning of the electric arc in the machining area are observed. That worsens the working conditions. In addition, when pulling the wire electrode tool along the convex surface of the electrode holder, the sliding friction arises, which eventually leads to mechanical destruction of the contact point. As a result, a deep kerf is formed on the electrode holder. When the depth of the kerf reaches the diameter of the wire electrode tool, the destruction of the electrode holder by the electric arc begins. Consequently, the durability of the electrode holder in the known method is unsatisfactory. A method of dimensional machining of bodies of rotation with electric arc using a wire electrode tool with the immersion of the machining area in the working fluid has been proposed, which makes it possible to improve the working conditions of the operator by eliminating the effect of fluid splashing and removing the luminous effect of arc burning in the machining area. In addition, it has been proposed to make the electrode holder in the form of a roller that rotates with a guide groove for the wire electrode tool, while the nozzle for creating the transverse hydrodynamic fluid flow has been proposed to be mounted in a separate fixed housing that is adjacent to the electrode holder. This technical solution replaces the sliding friction with the rolling one thus enhancing the durability of the electrode holder. Mathematical models of the process characteristics of the DMA-process (dimensional machining with electric arc) for bodies of rotation using a wire electrode tool with the immersion of the machining area in the working fluid have been obtained that make it possible to control the machining productivity, the specific machining productivity, the specific electric power consumption, and the roughness of the surface machined. Предложен и исследован высокопроизводительный способ размерной обработки тел вращения электрической дугой в гидродинамическом потоке рабочей жидкости и устройство для его реализации, которые улучшают условия работы оператора за счёт устранения эффекта разбрызгивания рабочей жидкости и устранения светового эффекта от горения дуги в зоне обработки, а также повышают долговечность работы электрододержателя.Item Розмірна обробка тіл обертання електричною дугою з використанням дротового електрода-інструмента(ЦНТУ, 2019) Боков, В. М.; Bokov, V.Запропоновано та досліджено високопродуктивний спосіб розмірної обробки тіл обертання електричною дугою з використанням дротового електрода-інструмента, який дозволяє підвищити точність обробки. Предложен и исследован высокопроизводительный способ размерной обработки тел вращения электрической дугой с использованием проволочного электрода-инструмента, который позволяет повысить точность обработки. In modern engineering electro-erosion methods are used for treatment of rotation bodies made of hard-to-machine materials. They provide non-force cutting and allow treating any electrically conductive material regardless of its hardness. Thus, a high-performance arc treatment method is known. The method applies a graphite electrode-tool, but it does not provide high machining accuracy due to increased abrasive wear of the electrode-tool. In addition, there is a method of electro-spark machining of rotation bodies which compensates for wear by pulling the wire electrode tool in the treatment area, but does not provide high processing performance. The author of the work combines the advantages of these methods. The result of the combination is a new method of dimensional arc treatment of rotation bodies using a wire electrode tool. Thus, the objective of the study is to improve the accuracy of the process of dimensional treatment by an arc of rotation bodies using a wire electrode tool. The basis of the proposed method is a new technological scheme of shaping the surface of the rotation body. An electric arc is excited in the hydrodynamic fluid flow between the workpiece electrode, which rotates, and the wire electrode tool, which is pulled in the treatment area along the convex surface of the electrode holder in a plane that is perpendicular to the axis of rotation of the workpiece electrode. The process is carried out with a guaranteed gap between the non-treated surface of the workpiece electrode and the electrode-tool without tracking the supply of the electrode-tool. Broaching the wire electrode tool allows compensating its wear. The use of the proposed method, in comparison with the known, allows increasing the accuracy of shaping the surface of the rotation body from 14 to 8 points of accuracy degree. Mathematical models of technological characteristics, characterizing the performance and quality of the process of dimensional arc treatment using a wire electrode-tool, which allow them to control and forecast, are obtained. The physical mechanism of formation of surface roughness is investigated. The possibility of forming the surface successively in several passes or in one pass is shown.Item Підвищення ефективності електродугового різання бідротовим електродом-інструментом(ЦНТУ, 2018) Боков, В. М.; Bokov, V.Удосконалено та досліджено високопродуктивний спосіб електродугового різання металів бідротовим електродом-інструментами шляхом застосування зворотного прокачування органічного середовища. Усовершенствован и исследован высокопроизводительный способ электродугового резания металлов бипроволочным электродом-инструментом за счёт применения обратной прокачки органической среды. Modern engineering applies electrical, physical and chemical methods for cutting hard-to-treat materials. In most cases it is the process productivity that determines the choice of a cutting method. We know the technological shaping scheme for electric arc cutting which compensates the electric erosion wear of the electrode tool due to the parallel pulling of two electrode tools (that is, a bipolar electrode tool) with the direct pumping of process water through the front inter-electrode gap clearance. However, the direct pumping creates conditions for the concentration of torsion products in the lateral gap clearance. As a result, long arcs appear which, on the one hand, form an inclined cutting surface and increase cutting time, and, on the other hand, they destroy the electrode holders. Besides, technical water, as the process water, partially conducts electric current. Due to this part of power linked up with the electrode is not effectively used/ The objective of the work is to increase the efficiency of electric arc cutting with a bipolar electrode tool by applying reverse pumping of the organic medium. We know the technological scheme for shaping which compensates the wear of the bipolar electrode tool due to its pulling in the cutting zone, in which the direct pumping of process water is used. However, the application of this technology creates conditions for the concentration of erosion in the lateral inter-electrode gap clearance. As a result, long arcs appear that form an inclined cutting surface and destroy the electrode holders. And the leakage of current (through water) reduces the cutting performance. The work suggests a new technological shaping scheme for the electric arc cutting by a bipolar electrode tool which uses reverse pumping and organic medium. The new scheme allowed eliminating the above-mentioned disadvantages of the known scheme. Experimental research was carried out and mathematical models of technological characteristics which allow managing and predicting productivity, accuracy and quality of electric arc cutting have been obtained. Thus, a high-performance method of electric arc cutting of metals by a bipolar electrode tool has been studied and improved by using reverse pumping of the organic medium.Item Електродугове різання металів бідротовим електродом-інструментом(ЦНТУ, 2017) Боков, В. М.; Bokov, V.Запропоновано та досліджено високопродуктивний спосіб електродугового різання металів бідротовим електродом-інструментами. Розроблено концепцію проектування експериментального верстата, що реалізує даний спосіб різання. The goal of the work is to develop a new way of electric arc metal cutting with electrode tool wear compensation and to develop a machine design concept. In this new of electric arc metal cutting that is proposed, a new cut shaping technology scheme, in which the electric arc is excited in the hydrodynamic flow of the working fluid between an electrode-blank and a composite electrode-tool, is used. This electrode-tool includes two parallel wires, which are pulled over the convex surface of the electrode holder. The work fluid is pumped into the cutting zone under a process pressure the electrode holder and into the gap between the wires; the size of the gap is less or equal two interelectrode end backlashes. This allows conducting the cutting process without the formation of technological protrusion between wires. Distinctive features of a new cut shaping technology scheme are reflected in a machine design concept, which ensures the following: optimal process conditions in the cutting zone, minimal cut width, maximum possible cutting performance, parallel pulling and tensioning of the two wires in the cutting zone, wire in pulling speed adjustment, cutting depth monitoring, optimum wear of the bi-wire electrode-tool. This article proposes and examines a high performance way of electric arc metal cutting with bi-wire electrode-tool. The physical cutting mechanism is described. Machine design concept, which implements this method, is developed. Experimental machine «Knife-1» for electric arc hard materials cutting with bi-wire electrode-tool is designed, manufactured and examined.Item Удосконалення розмірної обробки твердосплавних прокатних валків біполярним інструментом(КНТУ, 2010) Боков, В. М.; Сіса, О. Ф.; Попова, М. І.; Bokov, V.; Sisa, O.; Popova, M.Запропоновано та розроблено новий спосіб розмірної обробки твердосплавних валків біполярним інструментом, що дозволяє виконувати одночасну обробку двох деталей за один хід шпинделя з прогнозованим зніманням з них різних припусків. При цьому цикл обробки зменшується в 2,0 – 2,5 рази. A new method of dimensional processing of hardmetal rolls with bipolar tool is suggested and worked out. It allows to execute concurrently the processing of two details for one spindle travel with predictable excess material beveling. At that processing cycle is lessening as 2,0 – 2,5 times.Item Гідродинаміка процесу біполярної обробки електричною дугою двох твердосплавних валків(КНТУ, 2012) Боков, В. М.; Сіса, О. Ф.; Попова, М. І.; Bokov, V.; Sysa, О.; Popova, М.Запропоновано принцип активного керування гідродинамічним режимом потоку в торцевому зазорі при біполярної обробки дугою двох твердосплавних валків. The principle of active control hydrodynamic mode of the flow in the end clearance under the conditions of bipolar treatment by electric arc of two hard-alloyed rolls was proposed.Item Фізичний механізм формування електричною дугою шорсткості бічної поверхні(КНТУ, 2011) Боков, В. М.; Попова, М. І.; Bokov, V.; Popova, M.Досліджено та описано фізичний механізм формування електричною дугою шорсткості бічної поверхні електрода-заготовки в умовах варіювання кута нахилу твірної бічної поверхні електрода-інструмента. Physical mechanism of lateral surface roughness forming of electrode-billet in the conditions of inclination variation of lateral surface generatrix of electrode-instrument is studied and described.