Theoretical And Application Research Of Thermal Deformation Of Precision Planes

The thermal deformation caused by the change of temperature is widespread and inevitable. In the process of precision measurement and precision machining, the thermal deformation will lead to change of shape and size of the machine parts, thus lowers the accuracy of measurement and machining, and even influences the normal performance of mechanical apparatus. With the development of modern Science and Technology and the improvement of machining technology, the thermal deformation has been key technical barriers for improving the accuracy in these areas. So it is not only academic significant but also practically valuable to further study the mechanism of thermal deformation and measure it accurately, so as to take effective measures to minimize the impact of temperature. Under the funding from Education Department of Anhui province Natural Science Capital Program(Item Number:KJ2007B269). this paper completes the following major aspects on the basis of domestic and foreign thermal deformation theory and research results.Under the situation of temperature field changes, the conformation of a stress field in mechanical parts will generate strain, thus the original shape and size will be changed. For precision plane parts, the most direct manifestation is the change in flatness. This paper first qualitatively analyses the thermal deformation situation of precision plane parts, the result indicates that the shapes of precision plane parts are not similar before and after their thermal deformation. That is, precision plane parts perform a non-similarity feature before and after their thermal deformation. At the same time, this paper uses the large-scale finite element analysis software ANSYS to simulate the thermal deformation of precision plane parts, which provide a basis for the analysis of their thermal deformation laws and the impact on the processing accuracy. With a high-accuracy thermal deformation experimental devices employed to measure and control temperature, detect geometric parameters by mechanical, optical, electrical equipments, the thermal deformation laws of precision planes between 0℃—60℃can be studied experimentally. The results of experiment and simulation tend to a consistency, which shows the reliability of ANSYS simulation. Finally, this paper compares the same points and differences of thermal deformation between the three precision planes, which provides the basis for the selection of datum flat and further thermal deformation error correction during the mechanical measurement and process.