The Influence of Forces in the Cutting Zone on the Feed Drive Movement of a Milling Machine

An analysis of the influence of mechanical processes of metal milling on the accuracy of machining by a working body (a table with a workpiece) when the feed is controlled by a software program through a series of electric drives is an important problem. A review of literature revealed a lack of works on the estimation of force pulsations in the cutting zone during milling and their effect on the feed drive movement. To solve this problem, the authors of the article developed a mathematical model of the milling process that took into account two degrees of freedom, using which a simulation model was obtained to study pulsations of the force in the cutting zone in magnitude and direction. The study showed that during milling, especially with cylindrical and face mills, the amplitude of force pulsations in the cutting zone can reach 50% relative to the average value. The study of the influence of the milling parameters on the relative movement of the working body and the cutter made it possible to establish a relationship between the rotational speed of the cutter, feed per tooth and positioning error, as well as the error due to the characteristics of the feed drive. Expressions of the load torque fluctuations of the output shafts of the electric drives and the fluctuations of their rotation speeds caused by force pulsations were obtained.

References

[1] Kharchenko A.O. Metalloobrabatyvayushchiye stanki i oborudovaniye mashinostroitel’nykh proizvodstv [Metalworking machinery and equipment for machine-building industries]. Moscow, INFRA-M publ., 2015. 260 p.

[2] Cherpakov B.I., Al’perovich T.A. Metallorezhushchiye stanki [Metal cutting machines]. Moscow, Akademiya publ., 2003. 368 p.

[3] Bushuev V.V., Kuzovkin V.A., Molodtsov V.V., Filatov V.V. Analysis of metal cutting feed drives error and theirs reduction methods. Measurement Techniques, 2006, no. 6, pp. 18–22 (in Russ.).

[4] Dodonov V.V. Working accuracy enhancement for machine tools with digital programming control. Engineering Journal: Science and Innovation, 2016, no. 6 (in Russ.). Available at: http://www.engjournal.ru/catalog/mesc/tempp/1506.html, doi: 10.18698/2308-6033-2016-06-1506

[5] Veyts V.L., Kolovskiy M.3., Kochura A.E. Dinamika upravlyayemykh mashinnykh agregatov [Dynamics of controlled machine units]. Moscow, Nauka publ., 1984. 352 p.

[6] Mikhaylov O.P. Avtomatizirovannyy elektroprivod stankov i promyshlennykh robotov [Automated electric drive of machine tools and industrial robots]. Moscow, Mashinostroyeniye publ., 1990. 304 p.

[7] Onishchenko G.B. Teoriya elektroprivoda [Electric drive theory]. Moscow, INFRA-M publ., 2015. 294 p.

[8] Logominov V.A. Formirovaniye sherokhovatosti obrabotannoy poverkhnosti pri kontsevom tsilindricheskom frezerovanii tonkostennykh elementov detaley. Kand. Diss. [Formation of roughness of the machined surface during end cylindrical milling of thin-walled elements of parts. Cand. Diss.]. Zaporozh’ye, 2013. 226 p.

[9] Bykador V.S., Kostenko G.Yu., Babenko T.S. An occurrence of a self-oscillation in simple cutting system. Vestnik Voronezhskogo gosudarstvennogo tekhnicheskogo universiteta, 2016, no. 2, pp. 119–123 (in Russ.).

[10] Zakovorotnyy V.L., Fam D.T., Nguyen S.T., Ryzhkin M.N. Dynamic coupling modeling formed by turning in cutting dynamics problems (positional coupling). Vestnik Donskogo gosudarstvennogo tekhnicheskogo universiteta, 2011, no. 3(54), pp. 301–311 (in Russ.).

[11] Kudinov V.A. Dynamic machine calculations (basic principles). STIN, 1995, no. 8, pp. 3–13 (in Russ.).

[12] Kudinov V.A. Dinamika stankov [Machine dynamics]. Moscow, Mashinostroyeniye publ., 1967. 360 p.

[13] Sokolovskiy A.P. Zhestkost’ v tekhnologii mashinostroyeniya [Rigidity in mechanical engineering technology]. Moscow-Leningrad, Mashgiz publ., 1946. 207 p.

[14] Zakovorotnyy V.L., Blokhin V.P., Alekseychik M.I. Vvedeniye v dinamiku tribosistem [Introduction to the dynamics of tribosystems]. Rostov-na-Donu, InfoServis publ., 2004. 680 p.

[15] Zakovorotnyy V.L., Fam D.T., Bykador V.S. Self-Organization and bifurcations of dynamical metal cutting system. Izvestiya VUZ. Applied Nonlinear Dynamics, 2014, no. 3, pp. 26–39 (in. Russ.), doi: 10.18500/0869-6632-2014-22-3-26-39

[16] Ermolayev A.I., Erofeyev V.I., Plekhov A.S. Analysis of vibrations arising in the milling process. Bulletin of Science and Technical Development, 2019, no. 3, pp. 12–23 (in Russ.), doi: 10.18411/vntr2019-139-2

[17] Kozhevnikov D.V., Kirsanov S.V. Metallorezhushchiye instrumenty [Metal cutting tools]. Tomsk, TSU publ., 2003. 392 p.

[18] Bobrov V.F. Osnovy teorii rezaniya metallov [Foundations of the theory of metal cutting]. Moscow, Mashinostroyeniye publ., 1975. 344 p.

[19] Tlusty I. Avtokolebaniya v metallorezhushchikh stankakh [Self-oscillation in machine tools]. Moscow, Mashgiz publ., 1956. 395 p.