Research On Structural Optimization Design Of Small Gantry Machining Center

With the rapid development of domestic high-end manufacturing,such as the aerospace,the rail transportation,the large-scale power generation equipment and the high precision instrumentation,the equipment manufacturing area has put forward higher requirements for the surface quality and geometric precision of machined parts,this also prompted development in the direction of high efficiency,high speed,high precision machine tool.At the same time,in the fierce market competition,machine tool manufacturers must also be through the control of manufacturing costs to improve product advantages.However,the traditional experience and analog design and other methods have been far from meeting the development needs of modern manufacturing.Therefore,the introduction of modern optimization design in the structural design of machine tools to create high-performance and low-cost machine tool equipment is particularly important.The XHGS256 gantry machining center is taken as the research object,the purpose of this paper is to seek for a kind of optimization design method for the high stiffness and light weight of the machining center.For this reason,this paper combined with the design and optimization of the key parts and the whole machine of gantry machining center,the main research work carried out as follows:3D numerical model of the machining center is established by using SolidWorks software,then the static and dynamic characteristics of the original beams and columns are obtained by finite element analysis method.Through the comparison and analysis of the performance index of machine tools,find out the weak links,and extract the data from the concrete,laid the foundation for subsequent structure optimization.According to the defects of the key components of the column and beam,the topology optimization and size optimization combination design is used.The model of conceptual design of columns and beams is acquired by using topology optimization method,and then structure is designed in detail by size optimization.Finally,using the finite element method,analyzes the performance of the optimized structure,the results show that the new column structure quality is reduced by 6.16%,the maximum deformation decreased 38.63%,the first natural frequency is increased by 8.40%;the new beam structure in case of quality is basically unchanged,the maximum deformation is reduced by 17.69%,the first natural frequency is increased by 29.04%;both meet the design requirements.For the realization of lightweight of machining center,the design variables that affect the performance of the whole machine are selected by the method of experimental design and use the application of adaptive response surface method to realize the static and dynamic multi-objective optimization design of the machining center.Finally in order to meet the demand of the cutter head deformation index,compared to the original machine structure,the first and second frequencies are increased by 5.13% and 19.64%,the quality is reduced by 16.05%,the lightweight effect is remarkable.In this paper,the works of structural optimization of the key parts of the XHGS256 gantry machining center and the application of the multi-objective size optimization of the machine show that using modern optimization design method in machine tool design can effectively improve the machine static and dynamic performance,also can realize the lightweight design of structure.