Obrabotka Metallov 2015 No. 3

ОБРАБОТКА МЕТАЛЛОВ № 3 (68) 2015 80 ОБОРУДОВАНИЕ. инструменты accompanied by the appearance of the resonance, when the forced oscillation frequency, dependent on the operating mode, multiples the natural oscillation frequency of the tool. There is another phenomenon accompanying the deep holes’ machining, called chatter. This kind of self-excited vibration can also lead to resonance. It causes various working errors to appear, the one hardest to reduce being the wall thickness variation, which is presented due to the tool axis deviation in relation to the axis of the hole. Authors suggested a boring bar equipped with gyroscopic stabilizer. It contains a frame mounted on the body of stabilizer by the means of cardan suspension, which provides two degrees of freedom for the gyroscope. The third degree of freedom is offered by the boring bars’ body. Gyroscopic stabilizer mounted inside the boring bar and behind the tool. Thus, when the boring bar starts to bend the frame simultaneously starts to swing and it achieves the lateral vibration suppression. The paper covers the proposed method of deep holes manufacturing. A structure of gyroscopic stabilizer for boring bars with a large length-to-diameter ratio is presented. The experimental stand for the study of the process of damping by the proposed method is described. Ninefold reduction of the amplitude of the resonant vibrations is achieved in the forced oscillations frequency range of 152...1100 rad/s for following values of the natural oscillations frequency of the tool model: ω 01 = 9,41 rad/s, ω 02 = 9,55 rad/s, ω 03 = 9,99 rad/s, ω 04 = 10,11 rad/s. It is established, that achieving lower values of the vibrations amplitude requires the tool to be maintained in a resonant or near-resonant state. It allows minimizing tool axis deviation and its consequences, which reduce the ac- curacy of the deep hole machining. Keywords: deep hole boring tool, gyroscopic stabilizer of the tool. DOI: 10.17212/1994-6309-2015-3-75-81 References 1. Troitskii N.D. Glubokoe sverlenie [The Deep hole drilling]. Leningrad, Mashinostroenie Publ., 1971. 176 p. 2. Ushakov A.I. Dinamicheskie protsessy pri obrabotke glubokikh otverstii. Diss. kand. tekhn. nauk [Dynamic processes in the deep holes processing. PhD eng. sci. diss.]. Moscow, 1974. 177 p. 3. Utkin N.F., Kizhnyaev Yu.N., Pluzhnikov S.K., Shamanin A.A., Drozdov F.M., Nemtsev B.A., Bychkov N.A., Borzov V.F. Obrabotka glubokikh otverstii [The Deep holes machining]. Leningrad, Mashinostroenie Publ., 1988. 269 p. 4. Minkov M.A. Tekhnologiya izgotovleniya glubokikh tochnykh otverstii [Technology of precise holes manufac- turing]. Moscow, Leningrad, Mashinostroenie Publ., 1965. 176 p. 5. Kostyukovich S.S., Dechko E.M., Dolgov V.I. Tochnost’obrabotki glubokikh otverstii [Accuracy of deep holes manufacturing]. Minsk, Vysheishaya shkola Publ., 1978. 144 p. 6. Otenii Ya.N., Smol’nikov N.Ya., Ol’shtynskii N.V. Progressivnye metody obrabotki glubokikh otverstii [Pro- gressive methods of deep holes manufacturing]. Volgograd, VolgGTU Publ., 2003. 136 p. ISBN 5-230-04102-2 7. Gorelova A.Y., Pleshakov A.A., Kristal M.G. Metody povysheniya tochnosti obrabotki glubokikh otverstii [Ways to increase the accuracy of deep holes’ manufacturing]. Izvestija Tulskogo gosudarstvennogo universiteta. Tekhnicheskie nauki – News of the Tula State University. Technical sciences , 2013, no. 7–2, pp. 363–370. 8. Mikhik P. Reztsederzhatel’, dempfiruyushchii vibratsii [Tool holder that damps vibrations]. Patent RF, no. 2365471, 2009. 9. Korjukina N.A. Rastochnoi instrument [Boring tool]. Patent RF, no. 2298456, 2007. 10. Komaishko S.G., Komaishko A.G., Kulik G.N., Moisej M.V., Pluzhnikov S.K., Suzdal’ K.V., Tonkonog A.Yu. Sposob sverleniya glubokogo otverstiya v detail [Method of drilling deep holes]. Patent RF, no. 2421302, 2011. 11. Aschenbach B. Rotary mechatronical tool system for e.g. drilling process, has gyroscopic unit controlled de- pending on dynamic characteristic changes during chipping process, where axis of rotation of unit is identical to axis of rotation of tool. Patent DE, no. 102004024170 A1, 2005. 12. Deqing M., Tianrong K., Albert J.S., Zichen C. Magnetorheological fluid-controlled boring bar for chatter suppression. Journal of Materials Processing Technology , 2009, vol. 209, iss. 4, pp. 1861–1870. doi: 10.1016/j. jmatprotec.2008.04.037 13. Matsubara A., Maeda M., Yamaji I. Vibration suppression of boring bar by piezoelectric actuators and LR circuit. CIRP Annals-Manufacturing Technology , 2014, vol. 63, iss. 1, pp. 373–376. doi: 10.1016/j.cirp.2014.03.132