| With the development of manufacturing, we have more precise requirements for machinery manufacturing. And as the source of machinery manufacturing, the performance of machine is very important for us. Some scientists have concluded that the error due to thermal deformation holds 50% in the modern manufacturing errors of workpiece. Therefore, to improve the thermal characteristics of the machine has been the focus of scholarly research, and if we want to get it, we must know thermal characteristics law of the machine. I have put forward new ideas of rail friction heat loading and convection heat transfer coefficient on the basis of predecessors.Firstly, I make the TC500 vertical drilling center feed system for my study object. I developed appropriate conditions according to the characteristics of the machine and calculated theoretical equations of rails, bearings and other hot key parameters. The rail is divided into sections according to the contact area between the heating part. And I establish a function between heat load and time based on slider operation rule. Considering convective heat transfer coefficient is changing of the temperature difference varies, in this paper, the changing coefficient values will be loaded into wall by using the appropriate value with the wall temperature reaches the appropriate temperature.The temperature test experiments of the machine TC500 is taken on the corresponding conditions. I got the temperature data of heat sources such as slider, bearings, connecting block by using contact temperature measurement method, and then making the simulation model more perfect by analyzing problems of simulation model on simulation data.Finally, the developed simulation model was applied to thermal analysis of milling machine. And we got the temperature field and thermal deformation data of base, linker, column and other parts. This can provide the basis for the study on the thermal characteristics of optimization design. |
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