How to determine the casting surface of precision casting

The position of precision casting castings in the mold endangers the quality of precision castings, the precision of specifications, and the difficulty coefficient of modeling design and processing technology.

Selection criteria for pouring parts:

1. The key production processing surface or key production processing surface of precision casting precision castings is facing down or located on the side: when pouring, the vapor, slag and sand in the mold will increase, which will cause The upper end of the casting has shortcomings such as vent holes, weld bumps, sand holes, etc., and the lower part of the casting has the probability of defects, the structure is higher.

a. The pouring part of the CNC lathe body should have the slide rail facing down to ensure the quality of the key tunneling face. The quality requirements on the top of the circle are relatively high, and the vertical pouring plan is selected, so that the top of the circle is on the side, and the quality and quantity are evenly balanced.

2. The large plan view of precision casting precision castings is pouring downward or obliquely: Because the hot metal material liquid has obvious radiant heat to the upper end of the mold during pouring, the sand mold on the top of the wall swells and even cracks, making the large plan view There are shortcomings such as sand inclusions and sand holes. The large plan view faces downwards or the choice of inclined casting method can prevent the manufacturing welding defects of the large plan view.

3. The thick wall of the precision casting casting is facing down, inclined or inclined: In order to avoid the disadvantages of cold isolation and failure to pour due to the thick wall position of the casting, the thick wall with a large total area should be placed under the casting or placed at On the outer wall or inclined part.

4. The majority of the thickness of precision castings should be placed on the top or on the side of the clinical diagnosis surface. The key purpose is to facilitate the placement of risers in thick areas for feeding.