During the running of the freight train, the coupler tongue will be frequently pulled and compressed. During the pulling, the main bearing part is the inner wrist surface of the coupler tongue; During compression, the main bearing parts are the two ends of the inner wrist surface of the hook tongue and the curved surface of the compression push table. According to the simulation analysis results of mold filling and solidification process of hook tongue sand casting process, the following analysis conclusions are obtained:
(1) During the mold filling process of sand casting, the sand core at the pin hole of the hook tongue and the mold are facing the gate. Due to the large impact of liquid steel, the erosion will be serious, which may produce defects such as sand flushing, slag inclusion and sand sticking, which seriously affect the quality of sand casting and need to be optimized;
(2) During the solidification process of sand casting, although there are shrinkage porosity defects at the corner of coupler tail stop, the hot crack tendency of the corner of coupler tail stop and the inner corner of coupler wrist is large, because it is not the main bearing part, so it does not need to be optimized temporarily;
(3) The inner wrist surface of the hook tongue and the arc part of the guard pin flange close to the outer side of the hook wrist have large wall thickness, with an average of about 55mm, and the riser feeding channel is relatively narrow, so it is difficult to carry out effective feeding. During solidification, an independent liquid phase area will be formed, resulting in shrinkage porosity defects. The stress of the guard pin flange and traction flange is large, and the hot crack tendency is large. It is the main stress part, which needs to be optimized.