High Speed Vertical Machining Center Multi-objective Structural Optimization Design

With the full implementation of 2025 strategic plan "made in China",our country will be gradually transfer from great manufacturing nation to powerful manufacturing nation.The CNC machining has higher requirements for quality,development cycle and cost,so companies constantly trying to use the advanced design method and technology to optimize product design,in order to improve the performance and reduce the production cost.In this paper,we will focus on researching structure optimization with multi-objective,multiple variables and constraints through a variety of optimization methods,in order to realize the aim of reducing machine weight under the premise of CNC machining without reducing strength index.First,in order to master the dynamic and static performance of lathe bed,column,spindle box,workbench,saddle and the whole machine,and find out the weak links and space that can be optimized,this paper takes the VL1060 vertical machining center as the research object,and carries on the structure design and finite element analysis based on domestic and foreign related the lightweight design of the CNC machining.The dynamic and static characteristics research provided a strong theoretical basis for topology optimization of the column and multi-objective size optimization of lathe bed and spindle box.Second,through cell density as design variable,flexibility as objective function,volume fraction as constraint condition,we can apply topological optimization for column by using the method of relative density.According to the topology structure shape,unit structure theory and framework optimization theory,we can optimize the ribs layout of the column and build a new column to realize the aim of reducing machine weight under the premise of without reducing strength index.Third,based on the structural feature of lathe bed and spindle box,we can put the key design sizes of the lathe bed and spindle box as design variables,and put the quality,stiffness and 1 order natural frequency as the objective function of optimization,then we can determine the optimal value of the key design sizes through multi-objective size optimization based on response surface method in order to reduce the weight of machine under the premise of meeting the dynamic performance.Finally,we can assemble the CNC machining and carry on finite element analysis.In order to reflect the static and dynamic performance in the actual working conditions,we can make use of LMS equipment to test the dynamic performance of CNC machining and compare with the finite element analysis results.Through the experiment,we can verify the accuracy of the optimized model and the feasibility of the optimization method.The results show that after optimization of the whole machine weight reduce from 5852.3 Kg to 5571.14 Kg,weight loss of 4.8%,maximum deformation reduce by 21.1%,and the first three order natural frequency increase in different degrees,achieving the target of the CNC machining optimization design.