In the past, similar steel castings used the core assembly molding, and the size of the sand core is relatively large. If the core assembly molding is also used, the core box will be slightly deformed, which will greatly affect the shape of the overall steel casting. Real sample modeling is adopted as shown in the figure to ensure the overall dimension and surface quality of the overall profile of the steel casting. The outline dimension of splay saddle head is 5 212 mm × 3 500 mm × 3090 mm, gross process weight 162 t, 2 pieces in total. In order to ensure that the surface quality of the external mold and core box is good, without damage or missing, and the movable block is positioned accurately, before modeling, the model should be leveled and aligned, and the size of the model should be measured to prevent deformation, and the quality of the model production should be controlled and the inspection should be done well.
The model requirements are as follows:
1) This process adopts real sample molding and resin sand production. The surface of the model shall be smooth and clean. As the core is relatively large, it is required to ensure the rigidity of the core box to prevent deformation. Other unspecified draft angles+1:30
2) The rib plates sandwiched in the middle of NO.1~NO.5 sand cores are pasted with foam plywood, and the dovetail groove embedded positioning is made for the fillet of all rib plates.
3) The cross center line is carved on the wooden model, and the model fillets are embedded. The draft angle and positioning of the movable block shall be accurate. Work at the part with difficulty in mold lifting.
4) According to the process drawing, cast the casting type on the non machined surface and test material of the steel casting, and the casting type draft angle is+1:3
5) Half of the wood samples of the two risers shall be made respectively for the purpose of placing insulation sleeves.
6) The draft angle and correction of side reinforcement shall be added according to the drawing. The wood sample is pasted with plywood.
7）NO. The position of 9 cores shall be marked on the model. The marking line is led to the sand mold for positioning.