Thermal Characteristics Analysis And Test Of Machining Center

With the increasingly fierce competition in mechanical manufacturing industry, it raises more requirements on product quality and performance in the design of the machine tool. Compared to the static and dynamic characteristics of Numerical control machine in finish machining process, thermal error has become the main factors to the processing precision. In the design process, designers are used to only consider the static stiffness and the dynamic factors, do not consider the thermal characteristic data.This project is funded by the National Major Science and Technology Project ’high-grade CNC machine tools and basic manufacturing equipments’and National Technology Support Project. The project’s name is’digital design&software of machine tool oriented its static-dynamic-thermal characteristics’(NO.2009ZX04014-034), and ’concept-unitTechnology and Application in light-weight design of machine tool’(NO.2011BAF11B03).The thermal characteristics analysis of machine tools using Finite Element models and their experimental calibration techniques are presented in this paper. The concrete research works are focused on the following aspects:(1) The thermal characteristics analysis and calculation method based on the finite element and the relevant software have been develped. Through the review of the heat transfer theory, combined with the structure, heat-source distribute and operation condition of machine tool, The paper covers the basics of thermal deformation together with the analytical expressions and design data for the estimation of the magnitude of heat generated and determining the thermal boundary condition.Integrate the thermal characteristic coefficient calculation,test technique and the data processing into the software,forming machine thermal characteristic analysis calculation methods.The software is developed to realize the digital solution of the FEA loads and the boundary conditions of the CNC machine tool thermal characteristics, including three parts: the parametric mechanical loads distribution module, the parametric heat generation module, the heat transfer boundary conditions model.(2) The above methods and software have been applied in thermal characteristic analysis of the horizontal machining centre.Gets the temperature field and its spindle thermal deformation in different locations in processing space, analysis how many percent of the component’s thermal deformation in the contribution of the whole. The result can be used to provide the reference point to improve the thermal characteristics of the whole machine and. judge the reasonable structural layout in the stage of machine tool design.(3) Application temperature-displacement monitoring system and thermal infrared imaging system to test machine tool temperature field and thermal deformation of spindle under various regimes. Identify thermal loading of machine tools, test the thermal characteristics of the horizontal processing center.The experimental result is compared to the theoretical,it improve that the estimation of the magnitude of heat generated and determining the thermal boundary condition calculation model which is established in this paper is high credible.