Views: 3 Author: Site Editor Publish Time: 2018-04-07 Origin: Site
H2. Sand type precision casting is preferred.According to statistics, in our country or international, in total casting production, 60 ~ 70% of casting is made of sand,and about 70% of them are made of clay sand.The main reason is that sand casting is cheaper than other casting methods、the production process is simple and the production cycle is short.Therefore, the engine cylinder block, cylinder head, crankshaft and other castings are produced by using clay wet sand molding process.When the wet type cannot meet the requirements, consider using clay sand table dry sand type, dry sand type or other sand type.The weight of castings in wet sand moulds can range from a few kilograms to dozens of kilograms, while the casting of clay dry type can weigh tens of tons.In general, for medium and large castings, cast iron pieces can use resin self-hardening sand mold casting parts can be production of water glass sand mold, can obtain the size precision, smooth surface castings, but the cost is higher.Of course, the casting precision, surface finish, material density and metallographic structure and mechanical properties of sand mold casting are often poor.Therefore, other casting methods should be adopted, such as investment casting, die-casting, low-pressure casting, etc., when the performance requirements of the casting are higher.
H3. Low pressure casting, die-casting, centrifugal casting and other casting methods, due to the high price of equipment and mold, suitable for mass production.For small castings, the production line and real model of the non-box high pressure molding machine with horizontal parting or vertical parting are high and the area is small.In order to adapt to the requirements of fast and high-precision molding production line, we can choose a variety of production line and air-shock molding line of various boxes of high-pressure molding machines.Core method can be used: cold core box, hot core box, shell core and other efficient core method.Medium batch large castings may consider the application of resin from hard sand molding and core.Single small batch production of heavy castings, hand modeling is still an important method, manual modeling can adapt to various complex requirements more flexible, do not require a lot of technological equipment.Water glass sand type, VRH water glass sand type, organic ester water glass self - hard sand type, clay dry type, resin self - hard sand type and cement sand type can be applied.For heavy castings of single parts,the method is low cost and fast in production.Batch production or long-term production of finalize the design product box, split box shape modelling method is appropriate, although high mould and sand box to start investing, but from compensated save modelling cycle time, improve the quality of its products.