The choice of casting pouring position refers to the spatial position obtained by pouring in the mold. Whether the casting pouring position is selected correctly or not has great influence on the casting. The following principles should be followed when selecting:

(8) The important surface (machined surface) of the casting should be downward or sideways, because the cooling speed of the upper part of the casting is slow, the grain is coarse, and shrinkage cavities and pores are easy to form, and the density of gas and nonmetallic inclusions is low, so that defects such as pores and slag inclusion pores are easy to form in the casting. For example, the guide surface of the machine tool bed should face down. ?

(9) The wide plane of the casting should be downward, because in the casting process, the strong radiation of molten metal on the upper surface of the cavity is easy to make the molding sand on the upper surface expand rapidly and arch or crack, thus forming sand inclusion and scar defects on the casting surface. ?

(10) Thin-walled parts with large area should be placed in the lower part or vertical position of the mold, because if placed in the upper part, defects such as pouring failure and cold preservation may occur. ?

(1 1) For castings prone to shrinkage cavity, the thick section should be placed on the upper part or side near the parting surface, which is convenient for placing the riser and solidifying the castings from top to bottom. ?

(12) The number of cores shall be reduced as much as possible to facilitate the installation, fixing and ventilation of cores. ?

Selection of parting surface of castings:?

1) Simplify the setting process: the maximum section of the casting should be selected for the parting surface; The selection of parting surface should reduce the number of cores and parts as much as possible to simplify the process of mold making, modeling and matching. The parting surface should be as vertical as possible; Minimize parting surface. ?

2) As far as possible, the important machined surfaces or most machined surfaces of the casting and the machining datum are placed in the same sand box, which can reduce the possibility of misplaced boxes and burrs and maintain the machining accuracy. ?

3) The cavity and the main core should be located in the lower box, so as to facilitate the molding of the lower core and check the box size.