Low pressure casting is a method for metal liquid to fill the cavity from bottom to top under pressure and solidify under pressure. The pressure used is relatively low (usually 0.02~0.05MPa), which is called low pressure casting. Low pressure casting equipment generally consists of maintaining furnace and its auxiliary device, mold opening and closing mechanism, air pressure system and control system. According to the connection mode between mold and maintaining furnace, it can be divided into overhead low pressure casting machine and side low pressure casting machine.
The overhead low-voltage casting machine structure is currently the most widely used low-voltage casting machine type. It is characterized by simple structure, easy manufacture and convenient operation; But the production efficiency is low, because only one mold can be placed on maintaining furnace, in one production cycle of castings, all operations are carried out on the furnace, so nearly half of the maintaining furnace in one cycle is idle. Secondly, the lower mold is affected by the heat radiation of the maintaining furnace cover, and the cooling is slow, which prolongs the solidification time of the casting; Moreover, the lower mold cannot be set with the ejector rod device, which increases the inconvenience to the mold design. Maintaining furnace sealing, maintenance and alloy handling are inconvenient.
In order to overcome the disadvantage of overhead low-pressure casting machine, side-mounted low-pressure casting machine was developed, which placed the mold on the side of the maintaining furnace, and the mold and maintaining furnace were connected by Riser tube. Such a maintaining furnace can provide metal liquid for more than two models at the same time, thus improving the production efficiency. Loading, slag removal and Jinye treatment are also more convenient; The heating conditions of the mold are also improved.
