Збірники наукових праць ЦНТУ
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Item 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.Item Розмірна обробка електричною дугою бічної поверхні напрямного ролика з композиційного матеріалу на основі реліту(ЦНТУ, 2018) Сіса, О. Ф.; Пукалов, В. В.; Свяцький, В. В.; Сиса, О. Ф.; Свяцкий, В. В.; Sisa, O.; Pukalov, V.; Sviatskyi, V.Виконано обґрунтування технологічної схеми формоутворення зовнішньої бічної поверхні напрямного ролика, 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 «Реліт» з режимами обробки і геометричними параметрами. Выполнено обоснование технологической схемы формообразования внешней боковой поверхности направляющего ролика, 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 «Релит» с режимами обработки и геометрическими параметрами. The article is dedicated to development of technology and equipment of rough machining method by electric arc of a guide roller side surface, as high performance alternative to traditional methods of rough machining. During operation, the damage to the surface of the hard alloys guide roller caliber occurs by abrasion and chipping of carbide particles. The development of net shaped roll marks occurs by the occurrence of hotbeds of accelerated cluster abrasion and chipping of smaller particles with subsequent growth of these areas and unification in a closed net shaped roll marks. The turned out particles of hard alloy leave the machining marks on the wire, in such a worn the hard alloy rolling roller does not meet the specified dimensions and it is reground to a smaller diameter by grinding of diamond tool on the rough machining stage. It is proposed on the stage of rough machining to remove the worn-out profile of a guide roller side surface with help of dimensional electric arc, which allows you to remove big allowances of material at the lowest treatment costs. It is suggested to get the lateral surface by dimensional electric arc with a given roughness of Ra = 10..20mkm, which allows you to take great allowances material at the lowest cost processing time.In this case, the processing cycle of hard alloy side surface decreased of 1,4…2,6 times. The justification of technical scheme of forming the guide roller side surface by electric arc sizing method is done taking into account features of physical formatting mechanism and hydrodynamic phenomena in the electrode gap. The analytical communication of technological characteristics of rough machining process by electric arc made of composite material, based on relit, with the modes of processing and geometric parameters are established. The obtained models allow to control the productivity and specific productivity, specific electricity consumption, quality and surface accuracy which is processed, predicted and optimized given characteristics. A technical solution is proposed that allows to expand the technological possibilities of processing the guide roller.Item Технологія виготовлення порожнин високоміцних гайок спеціального призначення(ЦНТУ, 2017) Сіса, О. Ф.; Пукалов, В. В.; Юр’єв, В. В.; Sisa, O.; Pukalov, V.; Yuryev, V.Виконано обґрунтування технологічної схеми формоутворення поверхонь порожнини високоміцної гайки спеціального призначення, 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 сталі 20Г2Р з режимами обробки і геометричними параметрами. The article is devoted to the development of technology and equipment for the method of electric arc machining of cavities of high-strength screw-nuts for special purposes, as a highly effective alternative to traditional methods of processing. In the conditions of a single and small-scale production, high-strength nuts of special purpose with an internal cavity under a special key for tightening are used to assemble and fasten the critical elements of mining equipment, therefore it is economically disadvantageous to use the technology of stamping such nuts because of the high cost of the die tooling. The technology for manufacturing of special screw-nuts consists of two basic operations: obtaining a special nut billet and forming an internal special profile. An important factor in increasing the load-bearing capacity of high-loaded high-strength screw-nuts is to increase the elasticity of the thread. This is ensured by the grade of material and the quality of the steel billet. When developing technology and equipment, it is necessary to take into account the conditions that will ensure the production of high-quality threads and the formation of a reinforced cavity under a special tightening key with an appropriate surface roughness. Therefore, the method of dimensional processing by electric arc makes it possible to obtain hardened cavities with an appropriate roughness for a special tightening key. It is established that the optimal parameters of the walls of the cavities of high-strength screw-nuts of special purpose at processing capacity M = 6010 mm³ / min., dimensional electric arc, there is a roughness Ra = 6,3..21 mkm, which provides the necessary geometric dimensions and surface quality. It is proposed to receive cavities of high-strength screw-nuts of special purpose with a dimensional electric arc with a given roughness Ra = 6,3..21 mkm, side walls, which allows you to shoot large material allowances with the least time spent on processing. At the same time, the treatment cycle of the cavity of high-strength screw-nuts for special purposes decreased 10 times. The feasibility study of the technological scheme for the formation of cavities of high-strength screw-nuts of a special purpose by the method of dimensional processing by an electric arc is made, taking into account the features of the physical mechanism of formation and hydrodynamic phenomena in the interelectrode gap. Analytical links of technological characteristics to the process of dimensional processing by an electric arc of steel 20G2Р, with processing modes and geometrical parameters are established.Item Розмірна обробка електричною дугою бічної поверхні твердосплавного прокатного валка(КНТУ, 2014) Сіса, О. Ф.; Sisa, O.Виконано обґрунтування технологічної схеми формоутворення бічної поверхні твердосплавного валка 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 чорнової розмірної обробки електричною дугою сплаву ТС-15 з режимами обробки і геометричними параметрами. The article is dedicated to development of technology and equipment of rough machining method by electric arc of hard-alloy forming roll side surface, as high performance alternative to traditional methods of rough machining. During operation, the damage to the surface of the hard alloys roll caliber occurs by abrasion and chipping of carbide particles. The development of net shaped roll marks occurs by the occurrence of hotbeds of accelerated cluster abrasion and chipping of smaller particles with subsequent growth of these areas and unification in a closed net shaped roll marks. The turned out particles of hard alloy leave the machining marks on the wire, in such a worn the hard alloy roll does not meet the specified dimensions and it is reground to a smaller diameter by grinding of diamond tool on the rough machining stage. It is proposed on the stage of rough machining to remove the worn-out profile of hard alloy roll side surface with help of dimensional electric arc, which allows you to remove big allowances of material at the lowest treatment costs. In this case, the processing cycle of hard alloy side surface decreased of 1,9 times. The justification of technical scheme of forming the hard alloy roll side surface by electric arc sizing method is done taking into account features of physical formatting mechanism and hydrodynamic phenomena in the electrode gap. The analytical communication of technological characteristics of rough machining process by electric arc alloy TS-15, with the modes of processing and geometric parameters are established.