考虑模态耦合的球头铣刀颤振稳定域建模方法

球头铣刀广泛应用于曲面加工中,因此构造出针对球头铣刀的颤振稳定域叶瓣图意义重大。利用精细积分法对铣削系统二阶动力学方程进行时域数值求解,由切削刃与切触区域不同时刻的关系,确定出时域数值求解方程中所需要的刀刃瞬时切削部位,通过Floquet定理获得了高精度的颤振稳定域叶瓣图,并在三轴数控机床上进行了正确性试验验证。试验结果与预测结果相一致,表明所提供的方法能够为球头铣刀实现无颤振切削加工提供有力的技术支撑。

Modeling Method for Chatter Stability Lobes of Ball-End Mill Based on Precise Integration

Since ball-end mill plays an increasing role in machining sculptured surface, it is of great significance to construct the chatter stability lobes for ball-end mill. The precise integration method is proposed in this paper to solve the two order kinetic equation of the milling system considering modal coupling. Based on the condition of the period of delay equal to the single tooth cutting cycle, the instantaneous cutting parts of the cutting edges are determined by the relationship between the contact area and the cutting edge at different time. The Floquet theory is applied to acquire the high precision chatter stability lobes, which are verified by the flat surface machining in the three-axis numerical control (NC) machine tool. The experimental results are in good agreement with the predicted results, indicating the method proposed in this paper can provide the technical support for ball-end milling without chatter.