The method of casting liquid metal into the casting cavity corresponding to the shape of the part and obtaining the part or blank after it is cooled and solidified is called casting. Castings obtained by casting are called castings.

Cast parts refer to products produced by casting process. The so-called casting is a production method in which the liquid metal is cast into the casting cavity corresponding to the shape of the part, and the part or blank is obtained after it is cooled and solidified.

Casting structure design: ensure its working performance and mechanical performance requirements, consider the requirements of casting process and alloy casting performance on casting structure, and whether the casting structure design is reasonable or not has a great impact on the quality, productivity and cost of castings.

General principles for determining the pouring position of Dalian castings:

1. The important machining surface, main working surface and stress-bearing surface of the casting shall be placed at the bottom or side as far as possible to prevent casting defects such as sand holes, air holes and slag inclusions on these surfaces.

2. The pouring position shall ensure that the molten metal solidifies according to the determined solidification sequence. For the alloy with large shrinkage, the pouring position shall be conducive to sequential solidification, and the thick part of the casting shall be generally placed above the pouring position to facilitate the setting of feeding riser.

3. The pouring position of precision casting shall be conducive to the positioning, support and exhaust of the core, and the hanging core and cantilever core shall be avoided as far as possible.

4. The large plane shall be placed at the lower part or inclined lower part to prevent sand inclusion and other defects. In order to facilitate modeling, such methods as "horizontal vertical pouring" and "horizontal inclined pouring" are often used.

5. The thin-walled part shall be placed at the bottom or side to prevent casting defects such as insufficient pouring and cold shut.

6. Burr and flash should be easy to clean in mass production.

7. It is necessary to avoid segregation on the main working face under the riser of heavy castings.

There is never an easy thing in this world, and so is mechanical design. Anyone who is engaged in mechanical design starts from drawing simple parts. For example, surveying and mapping a simple part, helping others to draw a part drawing from the part drawing, etc. These are all stages that a novice must go through.

However, even a simple part drawing will be full of errors: or the dimensions are incomplete, or the tolerance dimensions are inappropriate, or there is a closed dimension chain, or the technical requirements are incorrect, and so on. Therefore, the machinery industry always needs a long time of accumulation and learning. The foundation is very important for a tall building to rise from the ground.