Збірники наукових праць ЦНТУ
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Item Удосконалення електроерозійної головки розмірної обробки дугою стрижнів на базі настільного свердлувального верстата(ЦНТУ, 2024) Сергеєв, А. О.; Боков, В. М.; Шмельов, В. М.; Serheiev, A.; Bokov, V.; Shmelov, V.Запропонована нова електроерозійна головка розмірної обробки дугою стрижнів на базі настільного електроерозійного верстата, що постачається підкладною плитою, через яку робоча рідина, разом з продуктами ерозії, вилучається із зони обробки. Показано, що використання даної головки покращує її експлуатаційні характеристики та дозволяє вилучати продукти ерозії із зони обробки без застосування ручної праці. 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.Item Багатомодульна електроерозійна головка розмірної обробки дугою(ЦНТУ, 2023) Сергєєв, А. О.; Боков, В. М.; Шмельов, В. М.; Sergeev, А.; Bokov, V.; Shmelov, V.Запропоновано концепцію багатомодульної електроерозійної головки розмірної обробки дугою, що включає склад, загальний технічний опис та схеми підключення модулів. Показано, що використання електроерозійної головки розмірної обробки дугою зі станцією робочої рідини та джерелом живлення технологічним струмом на базі настільного свердлувального верстата дозволяє розширити її технологічні можливості за рахунок використання багатомодульного принципу обробки без суттєвого підвищення вартості обладнання. In modern conditions at repair plants and workshops, there is a need to process various parts from hardto-machine materials, for example, from G13 steel, hardened steels and hard alloys. When implementing electropulse processing, the process is accompanied by mandatory pauses that negatively affect processing performance. A distinctive feature of the arc dimensional processing method, compared to electric pulse processing, is a significantly higher processing productivity (approximately by an order of magnitude or more), but stationary machines are massive, difficult to manufacture, occupy a large area and are very expensive. Therefore, only some of them are used for repair work. In addition, portable EDM machines and heads implementing the ROD process are used for repair work, but they have a narrow technological purpose.Item Удосконалення електроерозійної головки розмірної обробки дугою на базі настільного свердлувального верстата з ручною подачею електрода-інструмента(ЦНТУ, 2023) Сергєєв, А. О.; Боков, В. М.; Шмельов, в. м.; Sergeev, А.; Bokov, V.; Shmelov, V.Запропоновано самогальмувальну передачу в якості механізму керування ручною подачею електрода-інструмента для електроерозійної головки розмірної обробки дугою на базі настільного свердлувального верстата. Показано, що використання такої електроерозійної головки дозволяє покращати її експлуатаційні характеристики за рахунок розвантаження оператора від осьових зусиль при керуванні та підвищити якісні показники обробки шляхом зменшення кількості коротких замикань та підвищення точності керування. 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.Item Удосконалення технології розбирання металоконструкцій механізованого шахтного кріплення(ЦНТУ, 2023) Боков, В. М.; Сіса, О. Ф.; Мірзак, В. Я.; Телюта, Р. В.; Пукалов, В. В.; Bokov, V.; Sisa, О.; Mirzak, V.; Teliuta, R.; Pukalov, V.Запропоновано технологію для розбирання металоконструкцій шахтного кріплення, що дозволяє замінити фізично важку та небезпечну працю оператора на більш легкий, механізований процес з використанням потужного гідравлічного біпреса. During operation, the hinge connections of mine supports practically stop rotating. This is due to the fact that, as a result of the aggressive mine water and strong dustiness, the diametrical clearance of 1-2 mm between the axis and the bushing is tightly filled with oxides and coal dust, especially in the connections of the base. This circumstance leads to the fact that the axes (pins) in the hinges lose their mobility and require significant effort for their dismantling. To repair the mechanized mine support, it is necessary to dismantle the hinge connections, which are formed by axes and holes in levers (traverses), base ears, and overlaps. Currently, the dismantling of hinge connections of mine supports is carried out using manual impact tools. This operation is extremely labor-intensive, physically heavy, and belongs to hazardous work. The goal of the study is to improve the working conditions of the operator during the dismantling process of axes in hinge connections of mine supports by using a mechanized specialized hydraulic press. To achieve the set goal, the following tasks must be solved: to determine the maximum permissible disassembly force of the axes, taking into account the strength of the load-bearing structure elements; to develop a concept of a mechanized hydraulic press, including the composition of the installation, the general technical description, the principle of operation, the kinematic scheme, and the tool. Studies have been carried out on the deformation modeling of mine support elements under load using the SOLIDWORKS Simulation calculation module to determine the maximum permissible disassembly force of the axes. It has been shown that the disassembly load of the shaft support axis with a force of more than 1000 kN leads to the loss of the structural strength reserve, which is unacceptable. An effective technology for dismantling the axes of a mechanized mine support has been proposed. A concept of an original specialized hydraulic press "Kit-100" for dismantling axes has been developed, which allows replacing the physically heavy and dangerous work of the operator with a lighter, mechanized process.Item Фізичні особливості процесу багатоопераційного витягування циліндричних деталей із металевої сітки(ЦНТУ, 2022) Боков, В. М.; Сіса, О. Ф.; Мірзак, В. Я.; Свяцький, В. В.; Шмельов, В. М.; Bokov, V.; Sisa, О.; Mirzak, V.; Sviatskyi, V.; Shmelyov, V.Вивчено фізичні обмеження, що обумовлюють граничний коефіцієнт багатоопераційного витягування циліндричних деталей із металевої сітки. Виявлено явище пружності дротів сітки, в наслідок чого бічна стінка деталі набуває викривлену, близьку до конічної форму. Показано фізичну подібність процесу деформування окремого дроту металевої сітки при багатоопераційному витягуванні та процесу гнуття плоскої заготовки, що дозволяє визначити технологічне зусилля кожної операції витягування з застосуванням формул для розрахунку зусилля гнуття. Виявлено дві форми неусталеності процесу багатоопераційного витягування циліндричних деталей із металевої сітки з квадратним вічком та запропоновано новий спосіб витягування, який створює такі умови штампування, при яких асиметрична деформація деталі (непоправний брак) не спостерігається, а окремі додаткові засоби для обрізування краю відштампованої деталі не використовуються. In modern mechanical engineering, a method of single-operation extraction of cylindrical parts from a metal grid with a square mesh is known, which, in particular, has found application for the manufacture of microphone casings. Further improvement of the technology of extracting parts from a metal mesh in the direction of increasing the relative height of the stamped part is associated with the use of a multi-operation method of extraction. The study of this process will allow to significantly reduce the limit coefficient of extraction and thereby significantly increase the relative height of the part. Therefore, the work aimed at improving the technology of manufacturing parts from a metal mesh due to the use of a multi-operation method of extraction is an urgent scientific and practical task. The purpose of the study is to improve the technology of manufacturing cylindrical parts from a metal mesh by using a multi-operation method of drawing. The result of the work is the study of physical limitations that determine the limiting coefficient of multi-operational extraction of cylindrical parts from a metal mesh. The phenomenon of elasticity of the mesh wires was revealed, as a result of which the side wall of the part acquires a curved, close to conical shape. The physical similarity between the process of deformation of a single wire of a metal mesh during multi-operation drawing and the process of bending a flat workpiece is shown, which allows determining the technological effort of each drawing operation using formulas for calculating the bending force. In addition, two forms of instability of the process of multi-operational drawing of cylindrical parts from a metal grid with a square mesh were revealed, and a new method of drawing was proposed, which creates such stamping conditions, in which asymmetric deformation of the part (irreparable defect) is not observed, and separate additional means for cutting the edge of the stamped parts are not used.Item Витягування циліндричних деталей із не суцільного матеріалу(ЦНТУ, 2021) Боков, В. М.; Сіса, О. Ф.; Павленко, І. І.; Bokov, V.; Sisa, O.; Pavlenko, I.Запропоновано, розроблено та досліджено новий спосіб витягування циліндричних деталей із плоскої металевої сітки з квадратним вічком. В даному способі витягування здійснюють із квадратної заготовки, сторони якої паралельні діагоналям вічка сітки. Використання способу, що пропонується, порівняно з відомим, створює такі умови витягування, при яких нерівномірність висоти циліндричної частини деталі суттєво зменшується, що дозволяє на 35-40 % знизити собівартість штампування циліндричних деталей із плоскої металевої сітки з квадратним вічком. Запропоновано та експериментально випробувано новий спосіб витягування деталей з притиском фланцю плоскої листової заготовки, який відрізняється тим, що заготовку попередньо перфорують; перфорацію заготовки виконують тільки в області фланцю, внутрішній діаметр якої дорівнює середньому діаметру dс отриманої циліндричної деталі; перфорацію заготовки виконують так, щоб сума усіх перемичок за шириною аі на кожному концентричному колі розташування отворів перфорації дорівнювала довжини кола за середнім діаметром dс отриманої циліндричної деталі, тобто є справедливим вираз: . Використання способу, що пропонується, порівняно з відомим, створює такі умови витягування, при яких граничний коефіцієнт витягування значно зменшується (< 0,46), що дозволяє реалізувати більш глибоке витягування деталей за один хід пресу. A new method for drawing cylindrical parts from a flat metal mesh netting with square openings has been proposed, developed and investigated. According to this method, drawing is carried out from a square workpiece, whose sides are parallel to the diagonals of the netting mesh. A new method of drawing parts with flange clamping of a sheet workpiece has been proposed and experimentally tested, which differs in that the workpiece is pre-perforated; perforation of the workpiece is performed only in the flange area, whose inner diameter is equal to the average diameter dc of the cylindrical part obtained; perforation of the workpiece is performed so that the sum of all jumpers by the width ai on each concentric circle of the location of the perforation holes is equal to the circumference at the average diameter dc of the cylindrical part obtained, i.e. formula is valid. The use of the proposed method, in comparison with the known one, creates such conditions for drawing, under which the limiting drawing ratio becomes significantly lower (< 0,46), which makes it possible to conduct a deeper drawing of parts in one press run. The scientific novelty of this research is as follows. Usually, when manufacturing parts such as caps or box shapes, stamping is used in several runs to avoid the phenomenon of tearing- off of the bottoОдержаноm. However, the use of stamping in several runs leads to a complication of the process equipment and an increase in the cost of the product, which is justified only for cases of obtaining a high-quality product and provided that the integrity of the part is intact at a considerable depth. When trying to draw parts of considerable depth, objective difficulties arise associated with breaking-off of the bottom, which are due to exceeding by the tensile stresses in the critical section of the workpiece (between the bottom and lateral surfaces) of the ultimate tensile strength в of the latter. As part of the research described in this article, a way to overcome those difficulties has been proposed. It is based on the fact that when implementing the stamping process at lower values of the drawing ratio than the critical one, a metal mesh netting or perforated workpiece is used, and tearing-off of the bottom is therefore no longer observed. This method made it possible to obtain an integral shape of the part while using a significant depth of drawing due to the prior perforation of the workpiece, which significantly reduces the cost of the product. That means that the obtained scientific result in the form of a proposed kinetic description of the stamping process compared to the known one creates such drawing conditions, under which the unevenness of the height of the cylindrical portion of the part is significantly reduced, which in turn reduces by 35-40% the cost of stamping cylindrical parts from a flat metal mesh netting with square openings. This result is interesting from a theoretical point of view. As far as the practical point of view is concerned, a mechanism of transition of plastic bending of netting meshes into cold volumetric expanding of its constituent wires has been revealed, which makes it possible to determine the conditions for using the process of manufacturing parts from metal mesh netting or perforated workpieces. Consequently, an applied aspect of using the scientific result obtained is the possibility of improving the typical technological process of stamping, where the stamping force will be significantly reduced and hence the stress in the critical section, which will make it possible to reduce significantly the limiting drawing ratio and increase the depth of stamping. This constitutes prerequisites for the transfer of the obtained technological solutions of the process of drawing from a metal mesh netting or a perforated workpiece.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.