Papers by Author: Peter Monka

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Authors: Katarina Monkova, Peter Monka, Andrej Andrej, Matej Somsak
Abstract: The article deals with the welding fixture design for the rear headrest bracket of Audi. The fixture has to ensure the right position of individual components, because well done weld is the necessity of passenger ́s and transport safety. As the first, the 3D model of products was created then the fixture (and its components) was designed and at last the virtual model of the welding table for automated production was prepared in software Autodesk Inventor Professional. On the base of the model, the real fixture was manufactured and its functionality was verified in real production. The efficiency of the whole welding process increased several times in comparison with the previous hand welding activities. The initial costs invested in the automated process start-up have returned very quickly.
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Authors: Katarina Monkova, Peter Monka
Abstract: The article deals with the utilization of group technology inside new software. This software aids the multivariant manufacturing process plans creation and consequently it supported the processing of information in several versions. It can be used for optimization according to the selected criteria, for the generation of technological documentation and NC programs on the basis of hybrid approach. NC program, as one of process plans form, can be for individual parts generated automatically on the basis of group representative that is created as 3D model in CAD/CAM system. The output of CAM module – CL data – is imported into new software application as the basis of NC program. System was called Individual Application system – IAS.
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Authors: Katarina Monkova, Peter Monka
Abstract: The article deals with the influence of WC-Co deposition layer on some properties of steel C45. The coating was obtained by electro spark deposition followed by a laser treatment with three different powers of laser beam. Within experiments the tribological measurements were carried out at which wear resistance and friction coefficient were investigated. The results have shown that the highest coefficient of friction was measured at uncoated steel C45 without laser processing. The micro-hardness has been studied in three various layers of the samples. It can be said that towards the surface micro-hardness is significantly increasing. Maximum value of micro-hardness has shown steel with WC-Co coating, but after laser treatment the micro-hardness slightly decreased. Using point and line analysis, it was possible to find an evidence about mixing of C45 steel with WC-Co coating, i.e. about alloying. Based on results it is possible to say that laser treatment modifies the properties of coats applied in electro spark way along with base material.
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Authors: Katarina Monkova, Peter Monka, Slavomir Hric, Vladimir Ondek, Marek Urban
Abstract: The article deals with the investigation of chip dimensional characteristics that are created by the tool with linear cutting edge nonparallel to the workpiece axis. It is the tool with special geometry that was designed by authors in order to improve product quality and shorten the time of its production. Aim of the research has been focused on the obtaining of dependencies of the chip dimensions on both feed per revolution and setting of tool corner height in relation to the workpiece axis during machining of 12 050 steel. Measured data were processed statistically and they were evaluated by means of regression analysis in matrix expression. Measured data have indicated that with the increasing of feed per revolution, the chip width and chip thickness are increasing, too. As for the depth of cut, if it is increasing, the width of chip is also increasing, but chip thickness is not changing. The experiments have shown that the shape of chips at the machining by tool with linear cutting edge is not suitable for usage in production without direct control by operator. Therefore, when considering usage of this tool, it will be necessary to design the tool with chip breaker.
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Authors: Pavol Hvizdoš, Dagmar Jakubéczyová, Sergej Hloch, Ján Kľoc, Ján Balko, Peter Monka
Abstract: Various bone cements with different compositions were prepared in several model configurations which differed in volume (i.e. setting temperature profile) and mode of mixing (manual and vacuum bowl). Local mechanical properties (nanohardness, elasticity modulus) of all experimental states were measured by nanoindentation technique and compared. Role of the preparation route as well as influence of composition, particularly of presence of antibiotics, on the measured properties was investigated.
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Authors: Katarina Monkova, Peter Monka, Andrea Cizikova, Filip Murgas, Jan Rehor, Milan Edl
Abstract: The article deals with the modal analysis as a tool for specification of natural frequencies and the mode shapes of the turning tool. This type of analysis is the first step that is necessary to do at the dynamic analysis of technical components. At the beginning, the verification of numerical method was realized in laboratory conditions, where the fixed beam substituted the turning tool. Vibrodiagnostics of the real cutting tool in the workshop and the modal analysis using FEM in the software PTC Creo followed. It can be said that the results of the numerical method based on FEM were comparable with the data achieved by means of experimental measurements. The work described in this paper can be considered as a foundation for the dynamic tool life analysis.
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Authors: Jan Řehoř, Jaroslava Fulemová, Katarína Monková, Peter Monka
Abstract: High-speed cutting (HSC) or high-speed machining (HSM) is an issue that the scientists deals with in long-term. To demonstrate the explicitness, that a full HSC machining process is considered, it is necessary to monitor the series of factors. In particular, the process of chip formation, cutting forces, cutting temperature, vibration, tool life and surface finish quality in relation to the method of machining, machined material and its properties. The article deals with the detailed analysis and evaluation of the chip formation in order to determine the hard area, transition area and veritable HSC machining. The evaluation process is based on the proposed experimental model, which is confronted with the measurement results.
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Authors: Katarina Monkova, Peter Monka, Andrea Cizikova, Slavomir Hric
Abstract: The article deals with the mould running system design. The goal of design presented in the article was to propose the mould form so to be achieved the minimum waste for selected component. Studied component is intended to serve as a stopper in the automotive spotlight. The waste is considered the material that solidifies in the volume of plastic inside the running system. 3D model of the mould was created in Autodesk Inventor Proffesional software and then solidification of material was simulated in Autodesk Moldflow Insight software. There were designed three alternatives of running system at which the waste amount was evaluated. On the basis of the best solution, the real form was manufactured and placed into the injection moulding machine Arburg Allrounder 320 C.
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Authors: Katarina Monkova, Peter Monka
Abstract: The article deals with dynamic analysis of mechanism HR 3001 used at the lifting and transporting of various types of bodies or loads. It can be placed on the lorry so the manipulator becomes part of it. The goal of the analysis is to investigate the drive forces in hydraulic cylinders which are necessary for the lifting of load with specified mass. The modern methods used computer aid with the special software for analysis processing, which can simulate not only the motion of the mechanism, but they can define the position, velocity, acceleration, forces, moments and other parameters in every moments of time, but verification and mechanics laws understanding are necessary. The results serve for dimensioning of hydraulic cylinders at the designing of mechanism.
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Authors: Katarina Monkova, Peter Monka
Abstract: The article deals with the influence of the laser melting process on the surface roughness characteristics of the coat deposited on material by electrospark way granted by KEGA 035TUKE-4/2011 project of Ministry of education of Slovak republic. The aim of the article is research of material properties after coating by WC-Co and laser treatment. As the research method were used experiments and tools of statistics. Experiments were carried out on WC-Co coat (the anode), which was deposited on C45 carbon steel (the cathode) and molten by a laser beam. After surface treatment were analysed of changes in surface structure of the coat. Results of the research shows influence of parameters of this process to roughness, tribologic properties and morphology of the surface layer prepared by WC-Co coating and laser treatment.
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