Characteristic Analysis And Optimization Design Of WH-7 Horizontal Machining Center Column

NC machine tools are the main machine tools for manufactu ring equipment industry,and the important equipments reflecting the level of industrial technology,which are widely used in various fields of industrial manufacturing.In our country,research and development of NC machine tool started later,and is still in an important stage of rapid development and continuous breakthrough,and there is still a big gap between the international advanced level,especially in structural design and machining accuracy.In this paper,the main research object is the column of WH-7 horizontal machining center,through the finite element modeling method,analyzed the static and dynamic performance of the horizontal machining center,and proposed the optimization method of the column structure,finally made the optimization design to the column.The main contents include:(1)Dynamic performance analysis and finite element model of main joint surface in horizontal machining center with fictitious medium method.To establish finite element model of horizontal machining center,analyzed the static performance of the whole machine,and based on the finite element model,established the finite element model of main joint surface in horizontal machining center by fictitious medium method,got the accurate dynamic performance data.(2)Topological optimization of column by comprise programming method with satisfaction weighting factor.Taking the column as topological optimization object,using the satisfactory degree theory to improve the compromise programming method,a multi-objective topology optimization mathematical model with multi-case satisfaction weighting factor is established.Set up five sets of topological optimization mathematical models with different flexibility and frequency objective function weight ratio,selected the optimization result with the weight ratio of 0.7:0.3 which structure is cleared.Based on the optimization results,The column conceptual model of topological optimization is obtained.(3)Design of experimental scheme for key dimensions of column model and selection of optimal schemes by grey relational analysi s.Based on the column conceptual model of topological optimization,three critical column structure sizes,including the thickness of the rib in the support cavity,the width of the left support cavity and the wall thickness of the column support structure,were selected as experimental factors.Using the Box-Behnken experimental design method,got 12 sets of experimental schemes,established the column model of each experimental scheme,according to the four evaluation indexes: mass,maximum deformation,maximum stress value and the first order natural frequency,using grey relational analysis method to calculate the gray relational degree of each scheme,and the optimal scheme is selected.Comparing with the original horizontal machining center,it is found that the total deformation of the horizontal machining center with optimized column is reduced by 43.65%,the maximum stress value is decreased by 12.95%,the first to fouth order natural frequencies are improved in different degrees,and the first-order foundation is improved,especially the first order natural frequency has increased by 30.07%.These compare results proved the effectiveness of the optimized design of column structure of the horizontal machining center.