Figure 1 is the flow field simulation diagram of automobile steering wheel formed by opposite side casting. It can be seen from the flow field simulation diagram of the side casting automobile steering wheel that the liquid metal first flows into the gating system, and then flows to the rim and hub of the steering wheel. The filling time is 0.0629s, which indicates that the design of gating system is reasonable, the flow direction and velocity of liquid metal are appropriate in the filling process, and there is only a small amount of splash in the filling process. The overflow tank plays the role of containing slag.
Fig. 2 simulation diagram of automobile steering wheel formed by opposite side casting method. Figure 2 (a) shows the temperature field. The lowest temperature is distributed in the overflow groove. The shell of the casting is the low temperature zone of the casting, which meets the actual production requirements. Fig. 2 (b) shows the pressure field. The pressure at the rim of the whole gating system, hub and part is higher, and the pressure in the mold cavity decreases gradually, and there is no stress concentration phenomenon. The pressure is in a relatively stable state after filling. Figure 2 (c) shows the surface defects. When the liquid metal is filled, the oxide defects are mainly concentrated at the overflow groove of the last filling, and a small amount of oxide (cold shut-off) is produced at the flange and hub. Fig. 2 (d) shows the temperature field distribution of the casting (except the gating system) below the solidus after filling. After solidification, the temperature distribution of the die casting is uniform and the temperature difference is very small, so the phenomenon of early solidification will not occur, which reduces the possibility of shrinkage porosity and other defects.
According to the simulation diagram, it can be seen from the simulation diagram that there is no excessive metal splash during the filling process; the temperature distribution is reasonable; there is no stress concentration and the stress distribution is relatively stable; the oxide defects are concentrated in the overflow groove, and a small amount of oxide is produced at the flange and hub. If the center casting system is used, the liquid metal filling cavity will be incomplete and the liquid metal splashing will be serious, which will greatly increase the possibility of generating air volume and cold shut, and the central pouring will also cause great impact on the core, which will affect the service life of the steering wheel. In conclusion, the die casting should be side cast and can basically meet the actual production requirements.