Balanyuk H. Improving the accuracy and quality of multi-cutting boring of stepped holes based on the study of the technological system dynamics

The thesis deals with improving the efficiency of multi-cutting fine boring of stepped holes based on the study of dynamic interactions in the technological system. To reduce the vibration level this paper is concerned with its excitation sources, behaviour of change in the forced vibration level during multi-cutting fine boring, interaction of cutters, dependence of changes in weight-geometry parameters of cantilevered boring bars on their stiffness and proper frequencies, as well as the effect of radial cutting force components and position of cutters on the boring process efficiency. The calculation model has been refined to determine the forced vibration amplitudes, and behaviour of their change with the varied step lengths and diameters, the total boring bar length, stiffness, proper frequencies and cutting modes have been investigated. The theory of accuracy has been developed for fine multi-cutting step boring based on experimental and theoretical study of changes in the patterns of static and dynamic errors.