Taking the horizontal centrifugal casting machine for furnace tube supported by roller as the research object, the dynamic performance of the machine and the influence of various factors on its dynamic performance were systematically studied, including the influence of mold centroid distribution, the influence of roller and mold cylindrical error, the influence of roller and mold surface roughness and the influence of foundation characteristics – effect of liquid steel solidification coupling on solidification process and final wall thickness of furnace tube. The specific research contents of each chapter are as follows:
This paper introduces the research background of this paper, summarizes the research status at home and abroad from the factors affecting the vibration of centrifugal casting, the filling process of liquid metal, the solidification process of centrifugal casting and the research of rotating machinery dynamics, points out the shortcomings of the current research, and determines the research content of this paper.
The mechanical analysis of the centrifugal casting machine with roller support is carried out. The deformation of each part is obtained according to Hertz elastic contact theory, and then the support stiffness of each part is obtained through mechanical analysis. Then the dynamic model of the centrifugal casting machine is established by combining with vibration theory. The dynamic model is solved by transfer matrix method, and the roller support angle and support position are studied The vibration simulation test bench of roller supported horizontal centrifugal casting machine was designed and built, and the correctness of the theoretical model was verified through the simulation test.
Considering the surface shape error and surface roughness of the roller and the mold, the calculation model of the excitation force caused by the surface shape error and surface roughness of the roller and the mold was established by mechanical analysis. The excitation force was substituted into the vibration model to solve the problem. The influence of the surface error and surface roughness of the roller and the mold on the dynamic performance of the mold was studied.
According to the vibration theory, the vibration model is further improved. The performance and vibration of the foundation are introduced into the vibration model. Based on the calculation formula of stiffness and damping of the rectangular foundation, which is derived by Pais, and combined with the vibration theory, the transfer matrix method for solving the dynamic mechanical properties of the furnace tube in the off center casting considering the foundation vibration is derived. Through an example, the size of the foundation is studied The influence of soil and foundation characteristics on the vibration performance of centrifugal casting mold.
Through mechanical analysis, the coupling model of molten steel flow and mold vibration in horizontal centrifugal casting is established, and the coupling algorithm of molten steel flow and mold vibration is established. The amount of mold vibration and molten steel flow at each time can be calculated simultaneously. Through an example, the influence of the coupling effect of molten steel flow and mold vibration on the wall thickness of centrifugal casting furnace tube is studied.
Further considering the cooling and solidification process of the furnace tube, a coupled model of molten steel flow mold vibration molten steel cooling for horizontal centrifugal casting is established based on the theory of heat transfer. The model can solve the flow of molten steel in each section, the vibration of the mold and the temperature of each point at any time. The cooling and solidification process of the furnace tube and the vibration separation are studied through the analysis of an example The influence law of final wall thickness of core casting furnace tube.
This paper summarizes the research work, summarizes the main conclusions and innovation points, points out the shortcomings, and on this basis, prospects the further research work in this field in the future.