The effect of dynamic characteristics of machine tool spindle systems on the chatter stability in end milling

摘要

In this paper, simulated results for dynamic cutting process in end milling are reported to examine the effect of dynamic characteristics of spindle system in vertical machining center. The spindle system was represented by three degrees of freedom system consisting of spindle, tool holder and end mill. The dynamic parameters such as mass, stiffness and damping coefficient in each structural element are modified to investigate the interaction of these parameters onto the change of compliance transfer functions of spindle system. Simultaneously, the equations of motion for dynamic end milling process were solved numerically. And stability lobes are made to clarify the correlation with dynamic characteristics of spindle system. The results showed that mainly the modal coupling between tool and tool holder influences chatter stability. For the improvement of stability, stiffness of tool and tool holder is more effective than that of spindle. And then, the chatter stability is dominated greatly by both stiffness and mass than the damping coefficient at higher spindle speed range.