Evaluation of the influence of cutting modes on the vibration of the boring cutter and the accuracy of the processed holes on CNC machines

Autor: Yu.I. Boiko, O.A. Lytvynenko, V.A. Yanovskyi
Jazyk: English<br />Ukrainian
Rok vydání: 2020
Předmět:
Zdroj: Технічна інженерія, Vol 2, Iss 86, Pp 34-40 (2020)
Druh dokumentu: article
ISSN: 2706-5847
2707-9619
DOI: 10.26642/ten-2020-2(86)-34-40
Popis: The accuracy of hole machining is significantly affected by factors such as vibrations that inevitably occur during the manufacturing of parts in the technological processing system (TPS). Among them, the vibration of the cutting tool is the most negative phenomenon, since it affects the accuracy and roughness of the treated surfaces, the performance of the machine and the service life of the cutting tool. Cantilever fixing of the cutting tool when boring holes reduces the rigidity of the TPS, which leads to a decrease in their accuracy. Currently, there are no systematic studies of the effect of the vibration stiffness of cantilever fixing tools on the accuracy of the resulting holes. Therefore, the study of the influence of vibrations of the boring cutter on the accuracy of hole processing on numerically controlled machines (CNC) is of great practical importance. When processing parts on modern CNC metal-cutting machines, their performance can be determined by the potentiometer indicators, which allows you to analyze the efficiency of the cutting process, its stability, the amplitude and magnitude of tool vibrations. The article analyzes the influence of vibrations of cutting tools that occur in the TPS during processing on the accuracy of boring holes, using the example of developing a technological route for mechanical processing of a part ‒ a floating pin designed to ensure the alignment of guides in the mold body, using the inventor 3D CAD-CAM system and the «Siemens NX» program. The problem was solved by boring precise holes with a diameter of 30H7 in 40X hardened steel workpieces using a «Sandvik-A20s-STFCR 11-RB1 CoroTurn 107» anti-vibration boring cutter equipped with a replaceable TCMT090204-UM carbide plate. The study was conducted at a modern CNC turning and milling center of the HAAS DS-30y model. Theoretically, it is shown that reducing the vibration of the boring cutter when boring a precise hole is achieved in the following cutting modes: depth t = 0,4 mm, feed s =0,1 mm/rpm and spindle speed n, which changes in the «acceleration‒braking» time interval of 2 seconds, that is, increases from n =1800 rpm to n =2000 rpm and, conversely, allows you to get a 30H7 hole with a cylindrical tolerance of up to 0,02 mm at a length of 100 mm.
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