Збірники наукових праць ЦНТУ

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Author: search.filters.author.Pukalov, V.Subject: search.filters.subject.tool

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    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.
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    Розмірна обробка електричною дугою бічної поверхні зносостійкого інструменту
    (ЦНТУ, 2018) Сіса, О. Ф.; Пукалов, В. В.; Юр’єв, В. В.; Сиса, О. Ф.; Юрьев, В. В.; Sisa, O.; Pukalov, V.; Yuryev, V.
    Виконано обґрунтування технологічної схеми формоутворення зовнішньої бічної поверхні пуансону, способом розмірної обробки електричною дугою з урахуванням особливостей фізичних механізмів їх утворення та гідродинамічних явищ в міжелектродному проміжку. Встановлені аналітичні зв’язки технологічних характеристик процесу розмірної обробки електричною дугою твердого сплаву ВК8 з режимами обробки і геометричними параметрами. Выполнено обоснование технологической схемы формообразования внешней боковой поверхности пуансона, способом размерной обработки электрической дугой с учетом особенностей физического механизма образования и гидродинамических явлений в межэлектродном промежутке. Установлены аналитические связи технологических характеристик процесса размерной обработки электрической дугой твердого сплава ВК8 с режимами обработки и геометрическими параметрами. The article is devoted to development of the technology and equipment for rough machining of hard-face puncheon's lateral surface with electrical arc as a highly efficient alternative to the conventional methods of rough machining. In order to extend the durability period of the sheet material blanking die, the strong wearproof materials should be used. The hard-face axial puncheons are used due to high strength, hardness and wearproofness. The puncheons are made of the cylindrical hard-face cores, with diameter ranging from 2...20 mm. Then they are grinded. The cores are made of hard alloys with wolfram carbide grain size less than 1 µm, and the 8...25% of cobalt binding content. The cores are produced by the hard-face powder pressing and further sintering in vacuum-compressor furnace. When sintering the cores shrink, followed with the contraction process. The core bending may reach up to 0.35 mm and more. Such curve cores are not used for grinding. Therefore, the problem is to find some optional technologies of treating the hard-face cores for the puncheons. It is suggested to remove the puncheon's lateral surface with electrical arc at the stage of the hard-face blank treatment. This allows removing large allowances of material along with the shortest treatment time. It is suggested to produce the puncheon lateral surface with roughness of Ra = 16…30 µm following rough machining. Thus, the large allowances of material are removed with the shortest treatment time. Here, the treatment cycle of the hard-face puncheon's lateral surface reduces by 1.4...1.8 times. The substantiation was made for the process flow diagram covering fabrication of the hard-face puncheon's lateral surface subject to specifics of the physical mechanism of formation and the hydrodynamic phenomena in the inter-electrode gap. The analytical links were determined between the technological specifications of the process featuring ВК8 alloy rough machining with electrical arc, the processing modes and geometrical parameters. The resulting models enable managing the capacity, specific capacity, specific consumption of electric power and the treated surface accuracy, along with forecasting and optimizing these parameters. The technical solution is offered enabling to expand the processing capacities of the hard-face puncheon's production.