Particularities of multi-cutter cutting dynamics

Abstract

Certain particularities of steady continuous cutting dynamics for multi-cutter turning and the results of mathematical modeling are discussed in the paper. The effect of processing parameters on the excitation of vibration in the case of multi-cutter turning of a long cylindrical part with finite flexibility is studied. Depending on the fixing rigidity of the cutters and their relative positioning, different forms of the tool oscillation and formed chips are analyzed. The model is based on equations of motion and the cutting law in the form of a fractional function together with the equation for new surfaces formation which are represented as a system of differential-algebraic equations with several delays describing the dynamics of multi-cutter turning. These equations allow consider the regenerative mechanism of oscillations excitation in the system. The evolution of the cutter’s oscillations to steady regime in the case of an angular shift of the cutters, as well as the evolution of chips are shown in the work. An example of the operation of cutters, which angular shift allows to control the work of the cutting edges is given. The reasons for the stability loss and the self-oscillations excitation are noticed. The procedure for integrating systems of differentialalgebraic equations with retarded argument and the model of two-cutter turning taking into account the compliance of the cutting tool fixation is considered. Influence of the technological system parameters on the stability of continuous cutting regime is analyzed.