Metal Parts Batch Production
Casting is a method of producing a product by pouring molten metal into a cavity of a mold and cooling and solidifying. In the automobile manufacturing process, there are many parts made of cast iron, which account for about 10% of the total weight of the car, such as the cylinder block, the transmission case, the steering gear housing, the rear axle housing, the brake drum, various brackets, etc. .
Cast iron parts are usually made of sand. The sand type raw material is mainly composed of sand and mixed with a binder, water, and the like. The sand material must have a certain bond strength in order to be molded into the desired shape and to withstand the scouring of high temperature molten iron without collapse.
In order to mold a cavity in the sand mold that conforms to the shape of the casting, it is necessary to first make a model of wood, called a wood mold. The volume of the hot molten iron will be reduced after cooling. Therefore, the size of the wood mold needs to be increased according to the original size of the casting, and the surface to be machined is correspondingly thickened.
Hollow castings require the formation of a sand core and a corresponding core wood mold (core box). With a wooden mold, you can convert the cavity sand type (casting is also called "turning sand"). When manufacturing the sand mold, it is necessary to consider how the upper and lower flasks are separated to take out the wood mold, and also consider where the molten iron flows in, and how to fill the cavity to obtain a high quality casting
After the sand mold is made, it can be poured, that is, the molten iron is poured into the sand cavity. When pouring, the temperature of the molten iron is between 1250 and 1350 degrees, and the temperature is higher during melting.