Casting process design of tractor split axle housing by sand casting

The design takes the tractor split axle housing as the research object. The axle housing is made of zg40mn low alloy cast steel. The water glass sand mold casting process is adopted. The process of filling, solidification and casting defects of the axle housing are simulated by ProCAST computer simulation software. On this basis, the casting process of the axle housing is designed and optimized.

Three kinds of gating systems are designed, which are closed gating system, open gating system and semi closed gating system. Three different pouring schemes were simulated and compared by using numerical simulation software, and the gating system was optimized. The results show that the three semi closed gating system has the best process, the least defects and high production efficiency. It is the optimal gating system for axle housing casting. The main conclusions are as follows:

(1) Through the analysis of the simulation results of the filling flow field of the casting system of the axle housing, the sprue, the sprue and the sprue are always in the full state. The melt flow in each runner is smooth, without turbulence, and there is no obvious overturning phenomenon. Therefore, the casting defects such as sand hole and slag are less in the filling process of the axle housing.

(2) It can be seen from the temperature field of the filling mold of the axle housing that there is no fluid phenomenon such as cut-off and splashing during the pouring process of the molten metal, and the melt temperature is always above the liquid temperature line. Therefore, the possibility of casting defects such as cold shut, cold beans and insufficient pouring of the axle housing is very small.

(3) The results of computer numerical simulation show that shrinkage cavity and porosity appear in the isolated liquid region during cooling process. On the basis of the original scheme, a riser is added in the front of the inner gate, three risers are added at the top of the gate, and 6 are added in the inner cavity The results of numerical simulation show that the shrinkage porosity and shrinkage cavity in the axle housing completely disappear and all of them are transferred to the riser. Therefore, the scheme of three semi closed gating system is the best casting process scheme of this project.