Static And Dynamic Characteristics Analysis And Structure Optimization Of Turning-milling Machine Tool

In recent years,due to the increasing demand for small and medium-sized complex parts such as crankshaft and eccentric cam,the traditional NC machine tools have the disadvantages of low machining efficiency,poor precision and single machining products,so it is difficult to meet the market demand.The machine tool industry is developing in the direction of integration,automation and intelligence,so it is necessary to develop and study the multifunctional composite machine tool.In this paper,based on turning and combining the advantages of turning and milling,a new type of turn-milling compound machining machine is developed,and the static and dynamic characteristics of the machine are analyzed.Topology optimization and dimension optimization are carried out for the related parts of the machine tool.At the same time,some modal parameters are determined by modal experiments on the related components of the machine tool.In this paper,the function of the machine tool is concretely planned from the point of view of the processing requirement of complex parts,and the overall layout scheme of the machine tool is determined.According to the actual processing demand,the scheme of the lathe turning unit,the main drive system and the feed transmission system are made,and the calculation of the cutting force is completed based on the theory of metal processing,and the transmission of the cutting force is completed.The relevant parts of the moving parts were calculated and the motor was selected.The key parts of the machine tool were designed in detail,and the 3D model of the whole machine was built in PRO/E.Combined with the static analysis theory,the finite element model of the whole machine is established in ANSYS Workbench,the static simulation analysis of the whole machine under turning and milling conditions is completed,and the displacement and stress distribution cloud diagram of the whole machine at different working conditions is obtained.The static analysis results provide a reference for the identification of the weak links of the whole machine to some extent,and also provide a direction for the optimization of machine parts in the later stage.In view of the condition that the machine tool is turning and milling,the modal simulation analysis of the whole machine is completed,the first six natural frequencies and main vibration modes of the whole machine are obtained,and the vibration form of the whole machine is obtained.The harmonic response analysis of the whole machine is carried out and the weakest link of the machine tool and the parts to be optimized are determined.This result is consistent with the static analysis result.The structural optimization module of ANSYS Workbench software is used to optimize the structure of the machine tool column.According to the optimal distribution of material,the structure of the column is improved for the purpose of lightening.On the other hand,the size of the slide base of the tool holder is optimized,and the optimum structural design size is determined,so that the design requirement of reducing the weight can be achieved on the basis of maintaining the stiffness and strength.The vibration characteristics of spindle and worktable of machine tool are tested by setting up the modal test platform of machine tool parts,and the natural frequency is obtained.The order corresponding to its natural frequency is determined by finite element simulation.The experimental results verify the correctness of the simulation analysis and provide a certain method and experience for the vibration modal experimental study of machine tools.