Static And Dynamic Characteristics Analysis Of Birotary CNC Universal Milling Head

CNC machine tools are widely used as the main processing equipment of modem manufacturing industry. As the key component of five-axis CNC machine tools, the structure and performance of the bi-rotary CNC universal milling head significantly determine the performance of the whole machine tools. In this paper, static and dynamic characteristics analysis of the milling head were taken by combining theory, simulation and experiment.Firstly, analyzed the general layout, working principle and error source of the milling head. Based on multi-body kinematics theory, the geometric motion errors model has been established. And error component of the geometric motion errors in the base coordinates was carried out. According to the errors model, analyzed the influence of the swing of Aaxis to geometric motion errors of the milling head.Secondly, created finite element model of the milling head. To ensure the correctness of the finite element model, simplified the unnecessary parts as point mass and added them to the model. Then, considering three working conditions as A-axis is swinging and its real force condition, two steps were taken to analyze the mechanical property of milling head. We got deformations and stress of milling head varying with the swing of A-axis, and got the static stiffness of the milling head by calculating.Thirdly, based on static mechanics analysis, modal analysis and harmonic response analysis were carried out to the milling head. And obtained first six order modals and mold vibration of the milling head at three different working conditions, also got displacement response curve of tool apron central point. And got the dynamic stiffness of the milling head by calculating.Finally, static experiment was carried out to the milling head. To meet the demand of applying load, a device was designed. Proposed a method for static experiment, and obtained its real deformation when the milling head was under different force. The analysis conclusions can provide effective technical support for the design of the bi-rotary universal milling head.