The Static Dynamic And Thermal Characteristic Analysis Of The Turning Centre And The Structure Optimization Design Of The Saddle Bed

CNC Turning Center has been widely used in mechanical processing areas, which requirements the high performance of the machine, so, analyze the static and dynamic thermal characteristics of machine tool and optimal design of structural components is of great significance.The subject from the sub-topics of National Science and Technology Projects (NO.2009ZX040 14-034):"for static and dynamic thermal characteristics of tools digital design and software",(NO.2009ZX04001-031):"VHT series vertical machining and milling complex center",and National Science and Technology Support Program (NO.2007BAF21B01) "Development of Multi-axis high-speed gantry-type series of CNC", mainly use the method of finite element analysis to analyze the static,dynamic and thermal characteristics of key components, examine its comprehensive features, the topology optimization theory and structural design are combined to optimal design the structure of the saddle bed, this method made a very good design effect, the main research works are focused in the following aspects:The components and machine's mechanical model are established, which are based on analysis of the structure and the maximum working load of the turning center and the connection loads simplifying of CNC turning center, Static deformation of components and machine, processing error and stiffness are analyzed.The components are analyzed by modal analysis to get the first six natural frequencies and corresponding vibration modes, the dynamic characteristics of machine is analyzed to get the natural frequencies and corresponding vibration modes, in which the joint surface's impact of modal analysis is taken into account.The heat source is analyzed according to the steady-state heat transfer and convection heat transfer theory, the steady temperature field, thermal stress and deformation of the spindle box are obtained by the thermal characteristics analysis,furthermore, the stress and deformation are obtained based on the thermal-structural coupled analysis.The structure light-weight design method of the saddle bed of Turning Center is studied. The boundary and loads conditions of the saddle bed based on typical working conditions are analyzed. A multi-objective topology optimization model of the saddle bed based on volume constraint is established, which considers both the static performance on multiple load cases and the dynamic performance of the structure, then get the conceptual model and design the structure of the saddle bed based on the conceptual model,then new design plans are proposed. The weight of the saddle bed is reduced up to 14.33%,and the new structure can meets the static performance and the dynamic performance requirements, this new design method which is discussed in this paper is proved to be efficient on light-weight design.