Phase Characteristics of Self-Excited Chatter in Cutting

Abstract

The behavior of the self-excited chatter in cutting was investigated from the space phase point of view; the space phase is defined as that between outer and inner modulation. Records of oscillation for the horizontal motion of the work and those for the horizontal component of the cutting force were stored in a newly developed measurement system. The amplitude of the vibration increases for decreasing cutting speed and vice versa, the amplitude for the cutting force does not increase as the amplitude of the work motion does. Amplified and damped amplitudes for the decreasing and the increasing cutting speed are shown to be closely related to decreasing and increasing space phases, respectively. The mechanism of this phenomenon was analyzed on the complex plane by taking the cutting dynamics and the structural compliance into account. Attempts to suppress the chatter amplitude were conducted on the basis of these phenomena.