Analysis of mold filling process in sand casting of mud pump body

The traditional process design mainly depends on theoretical calculation and production experience. After determining the sand mold casting gating system of the mud pump body, trial production verification is required. In the process of trial production, if problems are found, the original gating system needs to be modified and then trial production verification. After repeated times, the final sand mold casting gating system of the mud pump body can be determined. This method takes a long time and increases the development cost. With the development of sand casting simulation technology, process designers can use simulation software to simulate and analyze the filling process of sand casting gating system of mud pump body, predict various defects that may appear in the filling process, and optimize the sand casting gating system of mud pump body through the simulation results. The application of simulation software can ensure the quality of sand castings, reduce the development cost and shorten the development cycle.

(1) The mathematical model and problems to be solved for the simulation calculation of sand mold casting filling process are described, including velocity field, temperature field, free surface problem and so on.

(2) The modeling design of mud pump body is completed by using the software Creo, which provides a three-dimensional model for the simulation calculation of sand mold casting filling process.

(3) The finite element mesh is divided by using the software geomesh and meshcast. The sand mold castings and sand mold materials are assigned in ProCAST. At the same time, the initial conditions and interface conditions required for mold filling model calculation are set, and the pre-processing of simulation calculation is completed.

(4) The software ProCAST is used to simulate the filling process of two sand mold casting pouring schemes of mud pump body, and the distribution diagrams of fluid metal temperature field and velocity field in the filling process are obtained. By analyzing the simulation results, various problems that may occur in the filling process are predicted, and the two sand mold casting pouring schemes of mud pump body are comprehensively evaluated, Finally, it is decided to adopt the process scheme and recalculate the size of each sprue of the gating system.

Simulation and analysis of liquid metal flow and heat transfer in sand casting filling process is an important content of sand casting process aided design and analysis. By simulating the flow process of liquid metal in the mold and gating system, the sand casting gating system of the mud pump body can be optimized to effectively prevent the suction of liquid metal in the sprue, avoid the oxidation of sand castings, reduce the turbulence of liquid metal, and reduce the possibility of air entry. Observe the filling sequence of the sand mold casting gating system of the mud pump body, evaluate the rationality of the size design of each sprue of the gating system, analyze the scouring degree of the metal liquid on the mold wall during the filling process, analyze the temperature field during the filling process, predict the defects such as cold shut and insufficient pouring, and provide the initial conditions of the temperature field for the solidification process simulation. Because the filling process is very complex, simulating the filling process requires solving a large number of mathematical and physical equations, such as continuity equation, energy equation and momentum equation, and multiple iterations are required to calculate the temperature field and pressure field. The amount of calculation is huge, and the iterative results are difficult to converge. It is difficult to verify the simulation results with experiments, special treatment of free surface problems and a series of problems, The numerical simulation of mold filling process is very difficult. However, with the development of computer technology, simulation method and testing technology, the simulation calculation of filling process is becoming more and more mature.

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