Three-dimensional Modeling of Deep Hole Vibratory Drilling Dynamics

In this work, a new three-dimensional approach to the numerical dynamics modeling of drilling processes with a special elastic device contributing to the tool's axial self-oscillations excitation on specified machining regimes is being proposed. The numerical model considers the possibility of self-oscillations excitation in the system due to the regeneration mechanism of cutting. Sufficient axial vibration amplitude causes fragmentation of chips, which significantly facilitates chip removal from the cutting zone and causes a positive influence on machining process quality. On the other side, in the device-tool-workpiece system along with the axial vibrations, lateral vibrations in other directions can be excited, which results in a distorted polygon-like shape of the drilled hole. Time realizations of device-tool system motion, machined surface configuration and the shape of the drilled hole were obtained for different machining regimes as simulation results. The proposed approach to the modeling and obtained results may be used in designing devices for vibratory drilling and to the rational machining regimes selection in the drilling of deep holes with application of such devices.