Danylchenko M. Ensuring of technological machining system dynamic quality during turning

The dissertation solves an important scientific and practical problem of increasing quality of turning by improving prediction and suppression technology of regenerative oscillations. This technology is based on the use of dynamic modeling results of interaction of the TMS with the cutting process, considering machining «by chatter marks». Unlike previous studies of methods and tools for regenerative oscillations suppression, to describe the interaction of elastic TMS and cutting process, it is proposed to apply the model of tool relative oscillations in 3D space. The model takes into account the influence of natural feedback between the elastic TMS and the cutting process on the depth, feed and cutting speed change. For the first time, the effect of machining «by chatter marks» was taken into account in the model in two directions - cutting depth and feed, which allowed obtaining the characteristics of the tool spatial movement relative to the workpiece as a function of stock change, directly related with controlled cutting data. To choose the form of elastic TMS representation, a theoretical and experimental study of workpiece and tool contact interaction during turning on the elastic TMS dynamic characteristics formation. Dynamic model of a lathe is considered as a complex mechanical oscillating system spindle unit-workpiece-carriage taking into account workpiece and tool contact interaction and components definition by distributed models. The results of the study proved the adequacy of the dynamic model of elastic TMS interaction with the cutting process, considered as single-mass system with elastic and dissipative characteristics determined experimentally. Comparison of simulation results and experimental studies on the variability of natural oscillation frequencies of elastic TMS during longitudinal feed of the cutter, correspondence of profile diagrams spectral characteristics of machined surfaces and free oscillations of TMS elements, as well as reduction of surface roughness when using SSV option on HAAS ST-30 (USA) with theoretically determined amplitudes and period spindle speed change period, confirms the adequacy of the developed mathematical models and the effectiveness of their application for SSV parameters determination on CNC lathes.