Research On Dynamic Performance Analysis Of Guideway Feeding System

With the development of China Made 2025,advanced numerical control equipment has been included in the national key development industry,and higher requirements have been put on the machining accuracy of advanced numerical control equipment.High-precision,high-speed and high-acceleration machining has become a trend,but in high-speed and high-acceleration feeds,the machine tool feed direction is prone to vibration,which directly affects the machining accuracy.The reason why the guideway feed system is prone to vibration in the feed direction is analyzed.The dynamic model of the guideway feed system is established using the D’Alembert’s principle.The influence of inertial force,friction force,and load quality on the system stiffness is studied.Law was verified by experiments.Theoretical calculations and experimental methods are used to determine various parameters in the mathematical model of the feed system,and the effects of system stiffness and damping changes on the system motion accuracy are studied,which lays a theoretical foundation for the subsequent improvement of guide rail motion accuracy.The main research content is as follows:A dynamic model containing inertia force and friction force was established.The equivalent axial stiffness of the feed system was calculated using the D’Alembert’s principle and the Hertzian contact theory,and the established dynamic model of the track feed system was simplified.The effects of the feed system’s high speed,high acceleration,and various parameters on the axial stiffness of the feed system were studied,and the inertial force and load quality and the variation of each component’s parameters on the axial stiffness of the system were obtained.Build a sliding guide and rolling guide vibration test system.The relationship between the feed acceleration of the guide rail and the amplitude of the guide table was studied under the condition of constant speed of the guide rail feed system.The relationship between the feed speed of the guide rail feed system and the amplitude of the guide table was studied under the condition of constant acceleration,and the correctness of the theory was verified.The dynamic characteristics of the guideway feed system were analyzed to obtain the system damping ratio,mode shape and natural frequency,which laid the foundation for subsequent theoretical analysis.The effects of variable stiffness and damping on system motion accuracy were studied,the open-loop and closed-loop transfer functions of the system were established,and the position error of the rail feed system due to stiffness and damping changes was analyzed,and an accurate mathematical expression was established.The modal experiment was performed on the sliding guide,the system damping parameters were identified,and the accurate mathematical expression of the feed system was established.Finally,the impulse response function of the feed system with different stiffness and damping is analyzed,and the main factors affecting the feed system’s motion accuracy are obtained.