(1) Application: Manual modeling is widely used in single piece and small batch production because of its flexible operation, simple process equipment, strong adaptability and no need for modeling equipment.

(2) Common manual modeling methods:

(1) Integral modeling: For castings with simple shapes, flat ends and the largest cross section, integral modeling should be adopted.

(2) Parting molding: For castings with simple shape, flat ends and the largest cross section, it is advisable to adopt integral molding.

(3) Three-box modeling: the casting shape is big at both ends and small in the middle, such as belt wheel, grooved wheel and lathe square tool rest. In order to ensure the smooth demoulding, three-box parting molding should be adopted.

(4) Movable block modeling: parts (such as bosses, ribs, etc. ) and the movable block is detachably connected with the die main body through a pin or a dovetail structure.

(5) Sand scraping modeling: When the outer contour of the casting is curved (such as handwheel) and its maximum cross section is not at the end, and the pattern is not suitable to be divided into two halves, the pattern should be made into a whole, and the molding sand that prevents the pattern from being taken out should be dug out during modeling. This modeling method is called dredging modeling.

Extended data

Casting is a process method of liquid metal forming, which is mainly used to produce blank parts. Casting has a long history. According to documentary records and textual research of unearthed cultural relics, it is proved that China's foundry production technology has a history of at least 4000 years. It can be roughly divided into two stages of development: the first two thousand years were dominated by bronze casting, and the smelting and casting technology was developed, forming a splendid bronze culture of Shang and Zhou Dynasties.

For example, the bronze wares unearthed in Hubei, weighing about 10 ton, have 64 chimes, which are beautifully cast, accurate in temperament and beautiful in timbre. It is fully proved that the smelting technology and casting technology of copper alloy reached a high level during this period. In the last two thousand years, it was mainly cast iron production. For example, the cast iron production technology based on pig iron casting farm tools and hand tools has greatly changed social production and promoted the development of casting technology.

For half a century, with the rapid development of national economy, China's foundry technology has developed rapidly. Foundry production, as the basic industry of industrial production, occupies an important position in machinery manufacturing. Roughly estimated, the proportion of casting weight in various machinery industries is: machine tools, internal combustion engines and heavy machinery account for about 70-90%; Fans and compressors account for about 60-80%; Tractors and agricultural machinery account for about 40-70%; Cars account for about 20-30%.

Casting production is a complex multi-process combination process, which includes the following main processes:

1) production process preparation: according to the parts drawing, production batch and delivery date to be produced, the production process plan and process documents are formulated, and the casting process drawing is drawn;

2) Production preparation, including preparation of materials for smelting, materials and patterns for molding and core making, core boxes, sand boxes and other process equipment;

3) modeling and core making;

4) melting and pouring;

5) Main processes such as sand falling cleaning and casting inspection.

References:

Baidu encyclopedia-casting