Obrabotka Metallov 2019 Vol. 21 No. 3

OBRABOTKAMETALLOV Vol. 21 No. 3 2019 56 EQUIPMENT. INSTRUMENTS References 1. Kudinov V.A. Dinamika stankov [Dynamics of machines]. Moscow, Mashinostroenie Publ., 1967. 359 p. 2. Tlusty I., Ismail F., Basic non-linearity in machining chatter. Annals of the CIRP , 1981, pp. 299–304. DOI: 10.1016/S0007-8506(07)60946-9 . 3. Tlusty I. Avtokolebaniya v metallorezhushchikh stankakh [Self-oscillations in machine tools]. Moscow. Mashgiz Publ., 1956. 395 p.) 4. Tobias S.A. Machine tool vibrations . London, Blackie, 1965. DOI: 10.1049/tpe:19640084 . The Influence of the Vibration on the Tool Shape-Generating Trajectories when Turning Vilor Zakovorotny a , Valery Gvindjiliya b, * Don State Technical University, 1 Gagarin square, Rostov-on-Don, 344000, Russian Federation a https://orcid.org/0000-0003-2187-9897, vzakovorotny@dstu.edu.ru, b https://orcid.org/0000-0003-1066-4604, sinedden@yandex.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2019 vol. 21 no. 3 pp. 42–58 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2019-21.3-42-58 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 10 April 2019 Revised: 21 May 2019 Accepted: 01 July 2019 Available online: 15 September 2019 Keywords : Nonlinear dynamic Vibrations Cutting process Geometric topology of the detail surface Funding This study was performed with finan- cial support of RFBR grant № 19-08- 00022 ABSTRACT Introduction. Vibrations always accompany the cutting process and affect the quality parameters of the parts and the state of the cutting process is estimated by the intensity of tool wear. Vibrations, generated by the machine itself (spindle group beats, kinematic perturbations, variations of the allowance, etc.), as well as specially controlled vibrations, introduced into the cutting zone to improve the quality of parts manufacturing, are considered in the paper. The trajectories of shape-generating movements depend on the trajectories of the executive elements of the machine, additional vibrations and elastic deformation displacements of the tool relative to the workpiece are changed by the vibrations. The trajectories of shape-generating movements are the main factor in the formation of the geometric topology of the part surface in the unity of geometric accuracy, waviness and surface roughness. However, to date, there is no consensus about the influence of vibrations on the quality parameters of the part. Method of research. The influence of vibrations on the trajectory of shape-generating movements of the tool tip relative to the workpiece is considered on the basis of mathematical modeling of the dynamic cutting system in the paper as the main factor determining the geometric topology of the part. In contrast to the well-known works, first, the dynamic link parameters are provided in the state coordinates. Secondly, the machines influence of the vibration perturbances on dynamic properties (for instance stabiliti) and machining result (primly geometric topology) is considered. Results and discussion. The simulation results, revealing the effects of nonlinear dynamics, which can cause both improvement and deterioration of the parameters of geometric topology, are presented. These effects appear in the formation of a dynamic constant component of deformation displacements, in the formation of the various attracting sets of deformation displacements along the trajectory and its bifurcations. The ways of improving the quality of the surface formed by the cutting process taking into account agreement of the input and (or) existing naturally external perturbations with the properties of the dynamic system and CNC-controlled trajectories of the executive elements of the machine are outlined. The aim of the research is to improve the efficiency of the process in terms of the quality of parts manufacturing. It can also be used to dynamically monitor state of the process during machining, such as tool wear. For citation: Zakovorotny V.L., Gvindjiliya V.E. The influence of the vibration on the tool shape-generating trajectories when turning. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2019, vol. 21, no. 3, pp. 42–58. DOI: 10.17212/1994-6309-2019-21.3-42-58. (In Russian). ______ * Corresponding author Gvindjiliya Valery E., Post-graduate Student Don State Technical University, 1 Gagarin square, 344000, Rostov-on-Don, Russian Federation Tel.: +7 (918) 583-23-33, e-mail: sinedden@yandex.ru