Study On The Dynamic Characteristics Of Woodworking Swing Milling Head

Woodworking swing milling head is a key core component of Wood five-axis high-speed machining center, and its dynamic performance directly affects the woodworking CNC machining accuracy and reliability. In this paper, high-speed and light-load carpentry double pendulum angle milling head as the research object, by collecting and reading lots of associated documents, the analytical methods for dynamic performance of woodworking swing milling head are determined. The aspects for errors, dynamics and vibration modes are studied to woodworking swing milling head. Details are as follows:(1) According to the principle and structure characteristics of wood high-speed five-axis machining center, the tool vector space model is built, and the error propagation equation is derived. The impact of timber deformation on machining accuracy is analyzed with force and hardness of the wood factor, to establish the corresponding error and compensation model. The numerical simulation results show that the model is valid.(2) Major error source of woodworking swing milling head is studied from the geometric and transmission error. On the basis of the pendulum shaft drive chain features, we analyze the relationship between the polygon effect and timing belt errors, and precision cycloid reducer the hysteresis characteristics, to establish the corresponding error model. The way is put forward that make direct use of laser interferometer to test the rotary axis precision of woodworking swing milling head. Respectively, rotary positioning and repeatability accuracy of the two pendulum rotation axis are tested. The results show that the rotating accuracy of woodworking swing milling head needs to be improved further, and appropriate measures about it are proposed.(3) The cutting torque model of woodworking swing milling head is built and preliminarily verified, with the empirical formula of cutting force and rotating homogeneous coordinate transformation matrix. Considering the actual work of the pendulum angular acceleration, driving quality and friction torque and other factors, the drive torque is derived. With analysis software based on virtual ADAMS, by dynamics simulation analysis the curves are obtained that corresponding angular acceleration, driving torque and other parameters. The results show that this woodworking swing milling head has a good comprehensive dynamic Performance, which could provide a reference for further optimizing its performance.(4) Considering the milling head structural features, method of the test modal analysis are determined to use, for studying vibration characteristics of woodworking swing milling head, according to the multi-body system theory and modal analysis method & principle. The way is put forward that make use PULSE multi-analyzer system, with hammering on the overall structure of woodworking swing milling head to be test modal analysis. With this method, the natural frequency damping ratio and structural modal shape corresponding the former six-modal are obtained, and the results show that vibration resistance of woodworking swing milling head could meet the requirements for wood processing.