Vibration distribution over support system of machine tools under ball-rod hardening of wheelpair assemblies

Introduction. Acoustic field in the allowable zone of the equipment operators, and, in particular, under ball-rod hardening of wheelpairs, is generated by the simultaneous emission of sound energy from two sources. The first one is the acoustic subsystem of “hardenable workpiece - reinforcer”. The second source includes all elements of the supporting machine system, in particular, spindle head housings, foundation slab, etc. When measuring sound pressure levels, it is practically impossible to detect the contribution from each separate source, therefore it is needed to carry out experimental studies on the distribution of vibrations throughout the entire machine carrier system both at idle speed and under the process implementation. Materials and Methods. Measurements of the vibration levels were carried out under certain technological operations. Roll surface machining was performed on a wheel-turning lathe on which ball-rod reinforcers were installed instead of cutting tools. Hard-facing of the landing surfaces of the wheelpair axles was carried out on a purpose-designed axle turning lathe on which the ball-rod reinforcers were installed in place of the cutters. Hard-facing of the wheel landing surface was carried out on a boring-and-turning lathe. In all these cases, octave vibration levels were measured at idle and under hardening. Comparison of the vibration spectra and noise spectra makes it possible to determine implicitly the contribution of the machine carrier system elements to the sound field at the operators' workplaces. Research Results. The research objectives, the results of which are given, consisted in studying the regularities in the distribution of vibration levels throughout the elements of the bearing systems of the ball-rod hardening equipment for wheelpairs. A qualitative assessment of the contribution of each source (hardenable part, reinforcer, and elements of the supporting system) can be performed on the basis of comparing the noise and vibration spectra. Measurements were carried out on three types of machines: special wheel-turning lathe on which the rolling surface is hardened; purpose-designed axle turning lathe on which the landing surface of the wheelpair axle is strengthened; and boring-and-turning lathe on which the wheel opening is reinforced. Discussion and Conclusions. The results of vibration measurements show that the intensity of sound emission of the machine carrier system elements does not cause excess over the sanitary norms of noise. Thus, the development of a noise-vibration protection system can be limited to the “hardenable workpiece - reinforcer” subsystem.

вибрация, шарико-стержневое упрочнение, колесные пары, vibration, ball-rod hardening, wheelpairs

1. Shumomery. Chast' 1. Tekhnicheskie trebovaniya: GOST 17187-2010. [State standard 17187-2010. Sound level meters. Part 1. Technical requirements.] Available at: http://www.g-ost.ru/51675.html (accessed: 12.10.17) (in Russian).

2. Ob utverzhdenii Metodiki provedeniya spetsial'noy otsenki uslo-viy truda, Klassifikatora vrednykh i (ili) opasnykh proizvodstvennykh faktorov, formy otcheta o provedenii spetsial'noy otsenki usloviy truda i instruktsii po ee zapolneniyu: Prikaz Ministerstva truda i sotsial'noy zashchity RF ot 24 yanvarya 2014 g. № 33n. [On approval of Methodology for special assessment of working conditions, Classifier of occupational and (or) process safety hazards, reporting form on special evaluation of working conditions and its completion guidelines: Order of Ministry of Labor and Social Protection of the Russian Federation of January 24, 2014, no. 33n] Available at: http://www.rosmintrud.ru/docs/mintrud/orders/170.html (accessed: 12.10.17) (in Russian).

3. Akustika. Izmereniya shuma dlya otsenki ego vozdeystviya na chelove-ka. Metod izmereniy na rabochikh mestakh: Natsional'nyy standart RF GOST R ISO 9612-2013. Federal'noe agentstvo po tekhnicheskomu regulirovaniyu i metrologii. [National Standard RF GOST R ISO 9612-2013. Acoustics. Noise measurement for the purpose of evaluating human exposure to noise. Method of measurements at workplaces.] Federal Agency for Technical Regulation and Metrology. Moscow: Standartinform, 2014, 42 p. (in Russian).

4. Natsional'nyy standart RF GOST R 54500.3-2011/ Rukovodstvo ISOMEK 98-3:2008. Neopredelennost' izmereniya. Chast' 3. Rukovodstvo po vyrazheniyu neopredelennosti izmereniya. Federal'noe agentstvo po tekhnicheskomu regulirovaniyu i metrologii. [National Standard RF GOST R 54500.3-2011. ISO/ IEC Guide 98-3:2008. Uncertainty of measurement. Part 3. Guide to the expression of uncertainty in measurement.] Federal Agency for Technical Regulation and Metrology. Moscow: Standartinform, 2012, 76 p. (in Russian).

5. O spetsial'noy otsenke usloviy truda: feder. zakon. [On special assessment of working conditions: Federal law.] Available at: http://www.rg.ru/2013/ 12/30/ocenka-dok.html (accessed: 12.10.17) (in Russian).

6. Shum na rabochikh mestakh, v pomeshcheniyakh zhilykh, obshchestvennykh zdaniy i na territorii zhiloy zastroyki: SN 2.2.4/2.1.8.562-96. [Noise at workplaces, in residential and public buildings, and on residential development territory: SN 2.2.4/ 2.1.8.562-96.] SCSES RF. Available at: http://docs.cntd.ru/document/901703278.html (accessed: 12.10.17) (in Russian).

7. Proizvodstvennaya vibratsiya, vibratsiya v pomeshcheniyakh zhilykh i ob-shchestvennykh zdaniy: SN 2.2.4/2.1.8.566-96. [Industrial vibration, vibration in premises of residential and public buildings: SN 2.2.4 / 2.1.8.566-96.] SCSES RF. Available at: http://docs.cntd.ru/document/90170328.html (accessed: 12.10.17) (in Russian).

8. Infrazvuk na rabochikh mestakh, v zhilykh i obshchestvennykh pomeshche-niyakh i na territorii zhiloy zastroyki: SN 2.2.4/2.1.8.566-96. [Infrasound at workplaces, in residential and public premises and on residential development territory: SN 2.2.4/2.1.8.566-96.] SCSES RF. Available at: http://docs.cntd.ru/document/1200029239.html (accessed: 12.10.17) (in Russian).

9. Chukarin, A.N., Minko, V.A., Finochenko, T.A. Uluchshenie usloviy truda operatorov vysokoskorostnykh prutkovykh tokarnykh stankov za schet snizheniya shuma. [Improving the working conditions of operators of high-speed bar lathes through reducing noise.] Rostov-on-Don: DSTU Publ. Centre, 2012, 140 p. (in Russian).

10. Stuzhenko, N.I. Eksperimental'nye issledovaniya spektrov shuma protsessa shariko-sterzhnevogo uprochneniya uzlov kolesnykh par. [Experimental studies on noise spectra of ball-rod hardening of wheel pair assemblies.] Vestnik of DSTU, 2017, no. 1 (88), pp. 92–98 (in Russian).