Перегляд за Автор "Kundrák, János"
Зараз показуємо 1 - 12 з 12
Результатів на сторінці
Налаштування сортування
Документ Changes in the values of roughness parameters on face-milled steel surface(Національний технічний університет "Харківський політехнічний інститут", 2020) Nagy, Antal; Kundrák, JánosIn this paper, the roughness characteristics of the face milled surface were investigated made with a parallelogram insert (κr = 90°) on C45 steel. Changes in surface roughness were analyzed for the specific surface created by the milling movement conditions (rotational main movement and linear feed motion). The topography was created by a tool moving in the plane of symmetry of the workpiece, which produced double cutting-edge grooves. We found that the roughness varies in different parts of the resulting pattern, and we analyzed its nature and the magnitude of the variance based on the average over the entire surface. Also, in parallel measurements, the Rz parameter was at its maximum in the symmetry plane, and in the perpendicular direction roughness values are the lowest in the middle and increase with distance.Документ Chip removal characteristics with constant chip cross-sectional area and different ap/fz ratios in face milling(НТУ "ХПІ", 2017) Sztankovics, István; Kundrák, JánosA main development direction in production engineering is the of the enhancement productivity of machining procedures among the increasing of the accuracy and the improvement of surface quality. Since the sizes of blanks are getting closer to the final prescribed dimensions of the parts, the depth of cut and/or the number of passes decreases. Therefore, the improved productivity in face milling can be achieved by the increase of the cutting speed and/or the feed rate values. Due to the spread use of high speed milling procedures the possibilities in the cutting speed increase are more or less applied, so the study of feed rate intensification came into view.Документ Comparative analysis of hard machined bores based on the roughness and accuracy(Національний технічний університет "Харківський політехнічний інститут", 2020) Kundrák, János; Sztankovics, István; Lukács, F.The results of a comparative study on the machining of hard machined surfaces are presented in this paper. We compared the surface roughness, roundness and cylindricity errors of bores machined by grinding, hard turning and a combined procedure. Based on the results we ranked the studied procedures to help in decision making in process planning.Документ Effect of cutting data selection on productivity in face milling(НТУ "ХПІ", 2018) Kundrák, János; Molnár, Viktor; Deszpoth, István; Makkai, TamásFace milling as a cutting procedure is used for high productivity manufacturing of prismatic components. In the automotive industry, characterized by mass production, the enhancement of productivity is a primary goal for manufacturing companies. There is a wide range of methods for increasing productivity. This paper analyses how productivity can be increased by the mach ining time, material removal rate and surface rate by choosing the appropriate cutting data. Cutting experiments were carried out for machining prismatic components and the change in machining time was analysed. It was proved that within the performance limits of the WGMT (Workpiece – Gadget – Machine – Tool) system a significant amount of manufacturing time and therefore cost can be saved while the geometric accuracy and surface quality of the component remain as specified in the blueprint.Документ Efficiency of material removal and machining in cutting(Національний технічний університет "Харківський політехнічний інститут", 2020) Molnár, Viktor; Deszpoth, István; Kundrák, János; Markopoulos, Angelos P.Among the methods and parameters used for analyzing the productivity of machining procedures, this paper deals with an analysis based on the efficiency (material volume removed in unit time) of material removal. The paper focuses on how this specific indicator, the material removal rate (MRR), changes when different machining procedures and production sub-phases are considered.Документ Examination of 2D and 3D surface roughness parameters of face milled aluminium surfaces(НТУ "ХПІ", 2018) Kundrák, János; Varga, Gyula; Nagy, Antal; Makkai, TamásMaterial removal with a rotating cutting tool has a series of special characteristics due to the movement relations. For face milling, looped cycloids occur, which also affects the roughness characteristics of the machined surface. This article analyses how the values of 2D and 3D roughness parameters change in symmetrical milling of flat surfaces of aluminium parts in planes parallel to the feed direction.Документ Experimental study on surface roughness of face milled parts with round insert at various feed rates(Національний технічний університет "Харківський політехнічний інститут", 2020) Kundrák, János; Nagy, Antal; Markopoulos, Angelos P.; Karkalos, Nikolaos E.; Skondras-Giousios, D.In the present paper, the variation of surface roughness of machined parts during symmetrical face milling is investigated. During this experimental work, the effect of using a milling insert with a round geometry under various feed rate values on the topography of milled parts is examined. For that purpose, both 2D and 3D surface roughness measurements were performed in three planes parallel to the feed direction, with one of the planes being on the symmetrical plane and the other two being at the same distance from it but in opposite sides. The analysis of the experimental results indicated that although surface roughness increases gradually with increase of feed rate, a considerable increase of surface roughness occurs for feed rate values over 0.4 mm/tooth. Moreover, the overall higher surface roughness values were found to be on the symmetrical plane, which was also more affected by the increase of feed rate than the other two planes.Документ Investigating the impact of feed and cutting speed on cutting forces for the increase of surface removal rate in face milling(НТУ "ХПІ", 2017) Kundrák, János; Makkai, Tamás; Markopoulos, Angelos P.Face milling is used for the manufacturing of engineering surfaces. A significant part of the produced surfaces pertains to flat surfaces with high quality. Surface quality, in turn, is connected to the machining conditions used in the process. In this paper, the influence of feed and cutting speed on cutting forces is experimentally investigated, with a view to increase surface removal rate A w (mm²/min) of the process. The experimental results are treated with ANOVA, indicate a high influence of the feed on all components of the cutting force. With the analysis, optimum conditions may be obtained with the aim of lower cutting forces.Документ Investigation of cutting force in face milling(НТУ "ХПІ", 2017) Kundrák, János; Makkai, Tamás; Deszpoth, István; Nagy, AntalThe increase of cutting applied in finishing processes can be achieved first of all by increasing the cutting speed and feed. In face milling, if feed fz per tooth is increased and/or the shape of the chip cross section is changed, the load of the cutting edges changes and influences the cutting forces and the actual efficiency. In this paper, the cutting force arising in chip removal and changing under the influence of the increased feed is analysed.Документ Roughness of aluminum surfaces face milled with a diamond tool(Національний технічний університет "Харківський політехнічний інститут", 2020) Kundrák, János; Makkai, Tamás; Nagy, Antal; Emri, G.This article describes the results of face milling experiments. The roughness parameters of machined surfaces with diamond were examined. Measurements were made in three planes parallel to the feed direction. Changes in the roughness profile diagram and roughness values as a function of the feed rate were analyzed.Документ Some features of the surface micro- and macroprofile formation at flat face grinding with spindle axis inclination(Trans Tech Publications Inc., 2015) Kundrák, János; Fedorovich, Vladimir; Pyzhov, Ivan; Markopoulos, Angelos; Klimenko, VitalyThe work described in this paper pertains to the identification of some features of microand macroprofile formation of surfaces to be machined with flat face grinding, with inclination of the spindle axis. The question of the formation of machined surface profile at through-feed grinding and multiple-pass scheme are considered by using computer-aided simulations in COMPASS environment. More specifically, for flat face through-feed grinding, a generalized empirical equation exhibiting the dependency of concavity from the outer diameter of the face grinding wheel, the spindle axis inclination angle and the width of the surface of the workpiece is acquired. Furthermore, based on the maximum allowable value of flatness deviation and with pre-determined grinding wheel diameter and workpiece width, it is possible to identify the maximum inclination angle at which concavity falls within acceptable limits. For the case of multiple pass flat face grinding, the role of factors such as inclination angle of spindle axis, cross-feed and diameter of the grinding wheel on the height of residual ridges on the surface of the parts is determined through the proposal of an empirical equation. With the aforementioned equations the machinist may reasonably prescribe machining conditions in practice. The conducted research contributes to the expansion of ideas regarding technological possibilities of improvement of flat face grinding.Документ Waste reduction possibilities in a manufacturing process(Національний технічний університет "Харківський політехнічний інститут", 2018) Molnár, Viktor; Szabó, Gergely; Kundrák, JánosIn this paper the manufacturing process of a high load-bearing capacity gear is introduced. These gears are built into truck and bus transmission systems and are machined at a high level of accuracy. The process has particular importance not only because the accuracy has to be ensured but because the machining of precision components requires relatively complicated processes. Here the process was described and quantified for a given component. The focus was on one-piece flow of components and its effect on decreasing lead time. On the basis of the analysis it was shown that one-piece flow can significantly decrease the lead time but the time spent with material handling increases, which results in a load on the operator or the material handling equipment. Therefore, multi-variable optimization is needed. The available results can be used for improvement of manufacturing processes of other component groups manufactured by similar technology.