March 2012


MM (Modern Machinery) Science Journal, March 2012
Stefan Valencik
Technical University of Kosice

The paper presents primer base of knowledge in the field of development of modules of machine systems, including their formation into specific assemblies in accordance with development, manufacturing and utilization strategy. The paper is based on elaborated strategy of architecture and development of reconfigurable machine systems, which was used at searching for new possibilities and principles of solutions and at elaboration of non-standard conceptions of 2D motion modules. In addition, the paper elaborates the module of machine system with integrated and reconfigurable effects with high internal and external compatibility. Elaborated reference structures of motion modules were used in practical phase of solution under construction of 2D motion module with reconfigurable impacts for synchronous movements in two axes, or for movements in one of these axes.

Keywords: producing technique, operating technique, dynamic module, integrated kinematics
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MM (Modern Machinery) Science Journal, March 2012
Jan Vesely, Jan Smolik, Pavel Rybar, Vojtech Matyska, Jaroslav Sindler, Tomas Zavazal, Lukas Havlik2, Tomas Kozlok3
RCMT, CTU Prague, 2 Kovosvit MAS, a. s., 3 TOS Varnsdorf, a. s.

Looking at modern machine tools from a design point of view, we observe that a number of their basic characteristics and methods used for their optimised design are the same. This even applies to very different categories of machines with different proportions, dimensions, parameters and specific structures. The project introduced in this paper—Synergic machine tool design (SMTD – aims to find such shared characteristics and use them in creating a knowledge and simulation system: SYNTOS. From an application point of view the system is oriented towards the support and development of new machine tools, with a special focus on the early stage involving the design of machine tool structures and drives. The aim is to assess a wide range of options linked to different initial requirements, and to systematise them for the purposes of selecting the definitive solution. During this selection process, the purpose is to provide the user with a number of dependences that make it possible to assess different configurations of machine drives and whole machine tool structures. The project has been implemented in cooperation between CTU-RCMT, Kovosvit MAS, a.s. and TOS Varnsdorf, a.s., with support from the Ministry of Industry and Trade of the Czech Republic (MPO).

Keywords: synergy, simulation, database, mechanical structure, drive
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MM (Modern Machinery) Science Journal, March 2012
Jaroslav Rasa, Radka Bicistova
Czech Technical University in Prague, Faculty of Mechanical Engineering,
Research Center of Manufacturing Technology
Prague, Czech Republic

The article presents the results of research on laser machinability of materials. The research has been carried out on pure substances, namely C, Zn, Ti, Si, Al, Ni, Cu, Fe, Cr, as well as different types of steel, cast iron, bronze, brass and titanium alloys. A diode-pumped solid-state Ns:YAG laser with a medium output power of 50 W has been used as the radiation source. Based on experimental results, a method for defining and evaluating laser machinability of materials has been proposed, including the classification of materials in corresponding machinability classes. The definition method is based on the crystal lattice type of the material. The impact of working speed and laser pulse frequency on machinability has been assessed.

Keywords: Laser, machinability of materials, pure substances, alloys, impact of working speed, impact of pulse frequency
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MM (Modern Machinery) Science Journal, March 2012
Andreas Archenti, Mihai Nicolescu and Thomas Lundholm
KTH Royal Institute of Technology
Department of Production Engineering, Stockholm, Sweden

The aim of this paper is to introduce a novel methodology, based on a finite element (FE) computation engine for simulation of process machine interaction occurring in machining systems. FE modelling of the milling process has the purpose of being accountable for a thorough validation of the parametric identification approach, and of providing a good physical insight into the phenomena investigated. The system considered here has a lower number of degree-of-freedoms which permits a thorough analysis. However, when taking into account the system’s nonlinear and time-varying nature, it is apparent that the results are far from being trivial. Therefore, the analysis of the milling process, taking into account nonlinearities restricting the growth of response amplitudes in the case of chatter-type instability, provides some intrinsic information of the basic features on the system that might be of both fundamental interest and practical use.

Keywords: FEM, milling, simulation, machine tool, cutting process
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