EFFICIENCY OF KINEMATIC CHIP BREAKING ON A CNC LATHE

Abstract

When turning many materials, especially such as high-alloyed steels and a some of non-ferrous metal alloys, long continuous chips are usually formed which clutter the working area of the machine tools and are dangerous for the workers. One of the effective and reliable methods of chip breaking during turning is vibration cutting, when the uniform motion of the cutter relative to the workpeace during the turning process is superimposed with an additional vibration motion of the cutter. The use of oscillating movements of the cutter in the direction of longitudinal feed is the most effective for chip breaking during longitudinal turning. To ensure the necessary amplitude-frequency range of cutter oscillations, the use of a toolholder with an elastic part in the form of a machined spring of cross slot configuration and directional stiffness. The toolholder is equipped with a mechanism of oscillating movements of the elastic part, which receives movement from the drive of the tool spindle of the machine tool. The development and research of the mathematical model of the cutting tool elastic system determined the conditions under which reliable chip breaking takes place regardless of the cutting modes and the properties of the processing material. The conducted experimental studies confirmed the effectiveness of the proposed toolholder with elastic elements for reliable chip breaking during longitudinal turning.

Key words: chip breaking, vibration cutting, mathematical simulation, toolholder with machined spring of cross slot configuration.