刀具螺旋角对高速铣削系统稳定性的影响

考虑铣刀螺旋角的影响，将刀齿的切削过程划分为连续，切入和切出3个过程，建立了高速铣削系统的动力学模型。运用半离散估计技术，将无限维特征值稳定性判定问题转化为有限维Floquet变换矩阵特征乘子稳定性判定问题，判定了系统的稳定性，获得了系统的稳定性极限图。结果显示，在考虑刀具螺旋角影响的情况下，铣削系统稳定性极限较传统情况有所增大，出现了类似“岛”的结构，其位置由轴向切削深度和螺旋齿距的关系决定，且由于切削刀齿切入、切出过程的影响，“岛”不是孤立的，而是有稳定性“桥”连接。理论结果通过铣削实验进行了验证。

INFLUENCE OF TOOL HELIX ANGLE ON STABILITY IN HIGH-SPEED MILLING PROCESS

An integrated dynamic model considering the influence of the helix angle is developed through dividing the cutting process into three cutting processes: uninterrupted, entry, and exit cutting processes. The semi-discretized technique is used to approximate the finite dimensional Floquet transition matrix of the dynamic control equation to determine the stability of milling process. The stability charts for helix mills are obtained. Results show that the helix angle plays an important role in the stability of milling process. The stability regions with helix angle become larger than those without helix angle. Some ″islands″ are presented in the stability charts, and ″island″ locations are determined by the relation between the axial depth of cut and the helix pitch. The ″islands are connected by the ″bridge″ by the effects of entry and exit cutting processes. The theoretical results are validated by milling experiments.