Abstract
By a programed variation of the spindle speed of machine tools, it is possible to control the onset of the regenerative-type self-excited chatter. In this paper, the effect of the wave form of spindle speed variation and the practical improvement of the metal removal rate in this method are theoretically analyzed, and the results are verified by some turning experiments. The results obtained are as follows. (1) Among various waves such as rectangular wave, sinusoidal wave, triangular wave and multi-stepped wave, the triangular wave is the most effective as the mode of spindle speed variation. (2) By means of complex method, it is possible to find more effective wave form of spindle speed variation theoretically. (3) If the dynamic characteristics of the cutting process and the machine tool structure are known, it is possible to predict the maximum allowable depth of cut under varying spindle speed.
