Structural design characteristics and casting requirements of precision castings

The structural design of precision castings should not only meet the requirements of the machine equipment itself and the requirements of mechanical processing technology, but also meet the requirements of the casting process. The structural design of castings should pay attention to the following points:

1、 To facilitate the manufacturing of models, core boxes, and shapes:

1) The inner cavity of small mixer and U-shaped mixer castings should strive to avoid or minimize the use of cores during casting. When using cores, it should be convenient for their support, fixation, and exhaust sand production. If necessary, sufficient process holes should be provided;

2) For structures such as the inner and outer sides of castings and reinforcing ribs, a certain structural slope should be set in the mold lifting direction;

3) The convex part on the casting should not differ too much from the casting body, and it is better to take the same height. Several convex parts that are closer to each other on the same side are better connected to form a whole convex part.

4) The appearance of castings should be as simple as possible to facilitate mold removal, and the casting parting surface should be as flat as possible with a smaller number;

2、 To reduce the tendency to produce casting defects:

1) It should be avoided to have large horizontal planes inside the casting as much as possible;

2) The casting holes on the flat wall of the casting should be reinforced with raised edges to reduce wall thickness;

3) The casting structure should be designed to allow for unobstructed shrinkage during cooling as much as possible;

4) There should be several connecting columns for large areas of interlayer cavities such as water and gas channels inside the casting.

Medium batch large castings can be considered for resin self hardening sand molding and core making.