考虑变时滞效应的弱刚度球头铣刀铣削稳定性研究  

Study on milling stability of weak-stiffness ball-end-milling-cutters with variable time delay effect

作　　者：董永亨[1] 李淑娟[1] 张倩 李鹏阳[1] 李旗[1] Dong Yongheng;Li Shujuan;Zhang Qian;Li Pengyang;Li Qi(School of Mechanical and Precision Instrument Engineering,Xi'an University of Technology,Xi'an 710048,China;School of Mechanical and Electrical Engineering,Guilin University of Electronic Science and Technology,Guilin 541004,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048 [2]桂林电子科技大学机电工程学院,桂林541004

出　　处：《仪器仪表学报》2021年第10期148-160,共13页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(52075439);校博士启动金(102-451121001)项目资助。

摘　　要：弱刚度球头铣刀广泛应用于深腔模具零件的铣削中,加工过程中容易发生颤振,确定加工稳定域是实现稳定铣削的重要手段,但该铣削系统具有变时滞特点,稳定性分析的难度较大,制约着加工质量的提高。为此,提出一种弱刚度球头铣刀铣削稳定性分析方法。首先,建立弱刚度刀具系统的动力学方程;接着,基于Newton-Raphson求解出刀齿选定点的时滞量;最后,基于全离散法提出考虑变时滞再生效应的稳定性分析方法,并利用Floquet定理获得了不同转速所对应的临界切深,构建出铣削稳定性叶瓣图。实验结果表明在叶瓣图的非稳定域铣削时铣削力中含颤振频率成分,所加工表面的S_(y)和S_(a)比稳定域内加工表面增大35%和42%,说明该分析方法是可靠的,可为切削参数的选择和优化提供依据。The weak-stiffness ball-end-milling-cutter is widely used in the milling of deep cavity die parts.The chatter is easy to occur in the machining process.How to determine machining stability region is an important way to enable stable milling.However,the milling system has a characteristic of variable time delay.It is difficult to analyze the milling stability,which restricts the improvement of machining quality.Therefore,a milling stability analysis method for the ball-end-milling-cutter with weak stiffness is proposed.Firstly,the dynamic equation of the cutter system with weak stiffness is established.Then,the time delay of the selected point of the cutter tooth is solved by using Newton-Raphson.Finally,based on the full-discretization method,a stability analysis method considering the regeneration effect with variable delay is proposed,and the critical cutting depth corresponding to different rotational speeds is obtained by the Floquet theorem.The milling stability lobe diagram is constructed.Experimental results show that there are chatter frequencies in the milling force when milling in the unstable region of the lobe diagram.Compared with those of the milled surface in the stable region,the S_(y) and S_(a) of the milled surface are increased by 35%and 42%.Results show that the analytical method is reliable,which can provide a basis for the selection and optimization of the cutting parameters.

关 键 词：弱刚度球头铣刀 振动 变时滞 稳定性 全离散建模法 

分 类 号：TH165[机械工程—机械制造及自动化]