Vibration Characteristics Analysis And Structure Optimization Of Vertical Machining Center

With the continuous development of science and technology,the processing of modern mechanical products puts higher requirements on the machining precision and processing efficiency of CNC machine tools.The machining center is obtained in the machinery industry because of its high efficiency,high precision and high stability.Widely used.The vibration characteristics of the machining center directly affect the machining accuracy of the machine tool.Therefore,it is important to analyze the vibration characteristics of the machining center and its main components.In this paper,the G7 gantry vertical machining center independently researched and developed by a company is studied.The vibration characteristics of the whole machine and main components are studied,and the key parts are optimized.The specific work includes the following aspects:Firstly,the modal test and vibration test were carried out on the vertical machining center.The modal parameters of the whole machine were obtained by the moving force hammer method.The vibration data of the vertical machining center under working condition was obtained by the variable depth of cut vibration experiment.After analyzing the experimental data,the main frequencies that cause the vibration of the vertical machining center were found,and the sources of these frequencies were analyzed.Secondly,the three-dimensional model of the whole machine of the vertical machining center is built and its finite element model is established.The modal analysis and harmonic response analysis of the whole machine of the vertical machining center are carried out by using the finite element method.The accuracy of the finite element model is verified by comparing the calculated results with the experimental data.At the same time,the modal analysis of the spindle box,cross beam and column of the main parts of the vertical machining center is carried out.Through the analysis of the calculation results,the weak links of the vertical machining center are found,and the spindle box and cross beam are determined as the main components for the next optimization.Finally,based on the finite element model,the structure of the cross beam is optimized and the layout of ribs in the cross beam is redesigned.At the same time,through the orthogonal experiment of the main structure size of the spindle box,the relationship between the structure size and the performance of the spindle box is explored,and the size of the larger size is optimized.By comparison,the dynamic and static performance of the optimized structure has been improved,and the processing accuracy has been improved.In this paper,the vibration characteristics of the vertical machining center are analyzed,and the weak links of the machining center are optimized.The results of the analysis and the methods used for optimization can provide a reference value for practical engineering.