Method for determining the pouring surface of precision casting

The position of castings in the mold during casting affects the quality of precision castings, the precision of specification and the difficulty of appearance skills.

Casting orientation selection criteria:

1. The primary processing surface or the primary processing surface of the precision casting faces down or is located on the surrounding surface: during pouring, the gas in the metal liquid, slag and sand particles in the casting mold will float up, which may make the upper part of the casting present such defects as air holes, slag inclusion and sand holes, while the lower part of the casting is arranged in a finer way under the possibility of defects.

A. The casting position of the machine bed should be such that the guide rail face down to ensure the quality of the primary working surface. The quality of the circular surface is relatively high. The vertical pouring scheme can make the circular surface be in the surrounding surface and ensure that the quality is uniform.

2. The large plane of precision casting is down or skewed pouring: because of the intense heat radiation of hot metal liquid on the upper part of the casting mold during pouring, the top sand mold will swell and arch and even crack, resulting in the defects of sand inclusion and sand holes in the large plane. Large plane face down or choose the method of skewed pouring can avoid large plane casting defects.

3. Thin wall of precision casting is down, side or skewed: in order to avoid cold insulation and pouring defects in the thin wall of casting, the thin wall with large area should be placed in the lower part of casting or in the side wall or skewed direction.

4. The thickness of precision castings should be placed on the top or around the parting surface. The primary purpose is to facilitate the placement of risers at the thickness for retraction.