エンドミル加工の再生びびり振動に関する研究 (第1報)

側面切削における振動発生限界の理論的解析

抄録

A new approach is proposed in order to clarify theoretically the stability of a regenerative chatter vibration in end mill operation. In this analysis, the dynamic cutting force due to the penetrating velocity of a cutter is considered in addition to the cutting force proportional to the uncut chip thickness. Furthermore, an unstable region to the chatter vibration is examined on a surface generated by one cutting. The results obtained are as follows. The chatter vibration occurs easily in the region where the instantaneous depth of cut is small. A low cutting speed and a high helix angle of the cutting edge increases the chatter stability. On the contrary, width of cut and depth of cut does not affect the chatter stability in usual cutting condition. The increasing of stiffness, natural frequency and damping ratio of the end mill is effective for preventing the chatter vibration. The chatter stability in down milling is lower than that in up milling.