切込み方向振動による切削過程のスティフネス伝達特性の解析

切削過程の動特性に関する研究 (第1報)

抄録

In order to study the mechanics of machining chatter, an investigation into the dynamics of the metal cutting process has been carried out using experimental approaches. A new experimental method is proposed to obtain the dynamic stiffness of metal cutting process without measuring the dynamic cutting force. In the method, the tool is attached to a cantilevertype structure and is excited sinusoidally with a small electrodynamic exciter in the direction of the principal mode of the structure, while both the dynamic force applied to the tool and the displacement of the tool are measured simultaneously. The dynamic stiffness of metal cutting process is given as the vectorial difference between the dynamic stiffness of the structure when in cutting and that when in not cutting. Dynamic cutting stiffness is shown in this paper as experimentally obtained when the tool is excited in the normal direction to the cut surface. The experimental results are shown to agree with the theoretical model of the so-called “penetration effect” proposed by Das and Tobias. Effects of depth of cut, feed rate, wave length of chatter marks and built-up edge formation on the onset of the regenerative chatter are also investigated in this paper.