Research And Application On Key Technologies Of Structural Dynamic Design And Optimization Of Machine Tool

With the development of modern manufacturing technology in high-precision, efficiency, automation, informatization and microminiaturization, nowadays the design of NC machine tool should consider various requirements correspondingly. However, owing to the lag of dynamic optimal design application, NC machine tool can't be always designed flexibly in response to market requirement in time. Aiming at the problem, this thesis presents the structure innovation and optimization design method of machine, which combines the modularization idea, FEA and intelligence optimization. And the research work is done to improve the dynamic characteristics and design efficiency of NC machine tool, based on the principle of static/dynamic property analysis and dynamic design for mechanical structure.The main work can be described as follows:First, the method of dynamic design and composite optimization of large parts using virtual modular technology are proposed. It mainly consists of two parts, the complex optimization of key dimension of large parts framework based on the BP-GA and the optimization design of partial character of machine tool structural elements based on the virtual modular design. Here, NC machine tool is divided into large parts module and virtual modular etc, according to the classification characteristics of machine structure. So the dynamic performance and innovation depend on the performance and features of these basic modules.Second, the example of complex optimization of the column and spindle box in a vertical CNC center is given. This section discusses the complex optimization method of key dimension of large part framework based on the ANN and the GA, and puts forward two means respectively, one is automatic search and optimizing calculation method for variables in optimized dimension design of large parts module, the other is coordination and optimization method for whole machine parts. And the method mentioned above can improve performance and design efficiency of NC machine toolmore.Third, according virtual modular design technology, the optimization design principle of partial character of large parts in NC machine tool is described. Here, the layout of the vertical CNC center is analyzed firstly, and the dynamic/static characteristic analysis of main components and whole CNC center are done using the finite element software such as Hypermesh and ANSYS. Furthermore, this section investigates the influence of ribbed plate unit structure and craftwork holes of framework on large parts performance, and takes the optimization of the square box and worktable of the pentahedron CNC center as an example to show the effectiveness of optimization design principle of partial character of large parts.Finally, the preliminary study of thermal characteristics analysis of spindle system of machine tool is carried out, using the example of milling head in pentahedron CNC center. Then, the main conclusions of this thesis are summarized, and more research assumptions are brought forward.