2022 № 96 Різання та інструменти в технологічних системах
Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/65925
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Документ The effect of the point sampling to the result of coordinate measuring of free-form surface(Національний технічний університет "Харківський політехнічний інститут", 2022) Varga, B.; Mikó, BalázsThe coordinate measuring technique appropriates to measure dimensional and geometric properties of a machine part. The result of the measuring is effected by several parameters, like the measuring method, the point sampling technique, and the mathematical processing of the measured coordinates. The current article investigates the effect of the point sampling methods in case of a freeform surface. Two methods are compared: the uniform matrix method, and the Halton-Zaremba quasirandom method. The number of measured points is investigated also. The free-form test surface was produced by ball-end milling, and the radius, the cylindricity and the surface profile error were assessed.Документ Theoretical value and experimental study of arithmetic mean deviation in rotational turning(Національний технічний університет "Харківський політехнічний інститут", 2022) Sztankovics, István; Kundrak, JanosThe calculation method of the Arithmetic Mean Deviation (Ra) is presented for rotational turning. The necessary equations for the calculation of Ra are given beginning from the equation of the cut surface theoretical profile, and we determine the theoretical values in the studied range of the technological parameters. Cutting experiments with these data were performed and the roughness values of the machined surfaces were measured. Then we carried out a comparative analysis of the measured and the calculated values ofthe arithmetic mean deviation.Документ Improving the processing quality of cylinder liners using combined technology(Національний технічний університет "Харківський політехнічний інститут", 2022) Nemyrovskyi, Ya.; Shepelenko, I.; Osin, R.; Posviatenko, E.Due to the use of surface engineering methods, a combined technology for processing the working surface of internal combustion engines cylinder liners has been developed. The advantages and disadvantages of traditional liners processing technologies are analyzed, which allowed identifying ways to improve them. A new technological process of cylinder liners processing is proposed, which includes operations of deforming broaching and finishing antifriction non-abrasive treatment. The technological equipment and tools for the chosen technological process realization are chosen. Experimental studies of the proposed technical solutions feasibility are carried out. The microrelief of the treated surface, roughness parameters, hardness distribution according to the wall thickness were determined for the studied liners, and the amount of wear was determined for the liners after running-in. Parameters analysis of geometric, mechanical and tribological characteristics of the liners working surface, processed by the existing and proposed technology showed significant advantages of the latter. There is an increase in the productivity of processing part up to 4 times, reducing the cost of the tool up to 3 times, and in general – reducing the cost of restoring the liner. It is proved that the use of the proposed technology allows improving the physical-mechanical characteristics of the working surface: strengthening the surface layer to a depth of 0.3 mm, as well as obtaining a roughness close to the operational.Документ Wear resistance of hard turned surfaces(Національний технічний університет "Харківський політехнічний інститут", 2022) Molnar, ViktorThe quality of working surfaces plays an important role in automotive industrial components. One of the main characteristics of such surfaces is their wear resistance. In this study external cylindrical surfaces were analyzed. A Design ofExperiment methodology was applied and hard turning experiments were carried out to analyze the effects of the cutting parameters on the 3D surface roughness values of reduced peak height, skewness and kurtosis. The study confirmed earlier findings that at lower feed the wear resistance is higher based on the analyzed roughness parameters. The cutting speed and the depth-of-cut do not influence these parameter values significantly.Документ Main technological factors determining the efficiency and quality of the vibration process(Національний технічний університет "Харківський політехнічний інститут", 2022) Mitsyk, A. V.; Fedorovich, V. A.; Grabchenko, A. I.The factors that determine the efficiency and quality of vibration treatment are indicated. Characteristic cases of interaction of abrasive granules with the processed surface are noted. The influence of the hardness of the processed part material and the shape of its surface, as well as the influence of chemically active solutions on the efficiency and quality of vibration processing, is substantiated. The characteristics of abrasive granules and their volume ratio with the processed parts are given. It is indicated that the underestimation of the possibilities of vibration processing technologies is explained by their insufficient studies. It has been established that vibration processing, depending on the characteristics and composition of the processing medium, is a mechanical or mechanochemical removal of the smallest particles of metal or its oxides and plastic deformation of microroughness due to mutual collisions of the medium granules with the processed surface, caused by vibrations of the reservoir in which the processing medium and, the processed parts are placed. It is noted that, according to the classification, vibration treatment refers to mechanical processing methods and, in particular, to the group of mechanical-chemical processing methods or to combined methods when chemically active solutions are introduced into the working medium, It is also noted that vibration treatment refers to dynamic, and for technological purposes – to dimensionless processing methods, according to the type of tool used - to the group of processing methods with a free abrasive. It has beene stablished that the efficiency of vibration processing depends on the oscillation modes of the vibrating machine, the mass of the processed parts and abrasive granules, the hardness of the parts material and the shape of their treated surfaces, the characteristics of the abrasive medium, the volume ratio of the parts and abrasive granules, as well as on the composition of the chemically active solution. The characteristic cases of interaction of abrasive granules with the processed surface are given. The situations of the highest processing productivity for performing the operations of vibration grinding, vibration polishing, washing and descaling have been established. It is noted how the hardness of the processed part and the shape of their surface affects the performance and quality of vibration processing operations. The characteristics of the working medium, which affects the efficiency and quality of vibration treatment, are given, including the influence of grain size and hardness of the material of abrasive granules. The volume ratios of abrasive and processed parts are considered. The types of actions on the vibration treatment processes are given.Документ The ralationship betwheen the parameters of roughness and features of surface formation with a special microprofile(Національний технічний університет "Харківський політехнічний інститут", 2022) Lavrinenko, V.; Solod, V.This article shows the regularities of the formation of the relationship between the parameters of the roughness of the treated surface under the conditions of processing with a tool made of superhard materials. Features offormation of the ratio of height parameters of roughness Rmax/Ra for conditions of diamond-abrasive processing are shown. In general, in relation to Rmax/Ra we have a kind of "roughness arc", when first for a normal untreated rough source surface it is close to 4, then abrasive-diamond treatment of this surface raises this ratio to 6 and then to 8, but further methods of abrasive finishing and polishing reduce the ratio to 6 and then chemical-mechanical polishing to a high-quality surface returns this ratio to values close to 4. This means that if the initial cost of grinding the original surface affects the increase in the ratio, then the subsequent cost of finishing and polishing work reduces the value of the ratio Rmax/Ra to the original. The peculiarities of obtaining a treated surface with a special microprofile, which is a flat protrusions with recesses (a kind of "pockets") for placing oil to increase the service life of such a surface.Документ The effect of elastic recoil of closed-type lifting ropes after their manufacture and drawing(Національний технічний університет "Харківський політехнічний інститут", 2022) Kurgan, V. O.; Sydorenko, I. I.; Vaysman, V. O.; Pavlyshko, A.; Litvinov, V. F.; Vovk, V.A study was made of stresses and factors of internal forces in the elements of ropes of a closed structure during their manufacture. It is established that when twisting a rope of closed construction, its shaped wires suffer from bending deformation, twisting and stretching. In this case, the shaped wires are subjected to a complex load with the concomitant rotation of the axes of the stress tensor. The stresses in the elastic cross-sectional area of the rope wire are considered and its limit is determined for shaped cross-sections and for asymmetric shaped cross-sections. Formulas for approximate determination of tangential and normal stresses in the elements of a closed rope of noncircular profile are obtained: (wedge-shaped, zeta-shaped and x-shaped).Документ Decision support method for the applicability of hard turning(Національний технічний університет "Харківський політехнічний інститут", 2022) Kundrak, Janos; Deszpoth, Istvan; Molnar, ViktorIn this study the applicability of hard turning is analyzed in the case of disc-shaped parts (gear wheels). The relevance of such parts has been increasing in the automotive industry; therefore, the efficiency of large series or mass production has high priority. The novelty of this paper is the collection of factors that has to be considered in preparation for applicability decisions of hard turning in order to ensure efficient machining. This can be the basis of the IT support, i.e. an automation solution for technologists. The introduced process is elaborated on the basis of theoretical considerations and production shop-floor experience.Документ Evaluation of performance efficiency of packing a group of products in the workplace of additive machine using a genetic algorithm(Національний технічний університет "Харківський політехнічний інститут", 2022) Garachenko, Ya.Research results of possibilities of packing a group of 3D-models of products in a layered build space using a genetic algorithm are presented. It is proposed to determine the efficiency of the optimization problem of rational arrangement of 3D-models group in the workspace of additive machines depending on the number of loaded products. Condition for efficient use of the layered build workspace is the minimum number of layers per product and the largest relative filling. Such criteria are important, for example, for SLS/SLM technologies. Examples of evaluation based on the analysis of derived voxel 3D model of the workspace with located products are considered. Industrial products with different geometrical complexity were selected as test 3D models. This approach allowed to perform a comparative analysis of the results depending on the design features of products. The practical realization was performed in the subsystem of packing 3D-models in a workspace, which is part of the technological preparation system for the manufacture of complex products by additive methods. This system was developed at the Department of "Integrated Technologies of Mechanical Engineering" named after M. Semko of NTU "KhPI".Документ Optimisation of Milkrun routes in manufacturing systems in the automotive industry(Національний технічний університет "Харківський політехнічний інститут", 2022) Francuz, A.; Banyai, T.The in-plant supply has a great impact on the performance of manufacturing operation, because the manufacturing-related logistics operations influence the efficiency of manufacturing. There are different solutions to perform in-plant supply, in the automotive industry the milkrun and water spider solutions are widely used. Within the frame of this article the authors describe the optimization of milkrun routes in the manufacturing plant of an automotive supplier. The described methodology simplifies the problem for single- and multi-milkrun problems and the solution is demonstrated with an Excel Solver-based methodology. The optimization process and its practicability will be demonstrated through an example.