Modeling is also known as vacuum modeling. At present, molding technology has become one of the world’s advanced modeling. It is used to produce various castings of various casting alloys. According to the market demand, in order to improve the casting quality and reduce the cost, a kind of rotating film was proposed. The vacuum solution of vacuum pump in the process of vacuum molding can improve the internal and external quality of castings, reduce the production cost of castings, reduce labor force, create more benefits and compete in the market.
The vacuum forming process has the following characteristics:
(1) The casting quality is good, the dimensional accuracy can reach gb5 ~ 7 and the surface roughness can reach 25 ~ 6.3 μ M;
(2) The casting cost is low;
(3) Good working conditions;
(4) Reduce capital investment;
(5) The productivity of the automatic forming production line is still lower than that of the high-pressure molding production line and the air stamping molding production line. The shape of the castings produced should not be too complicated, and it is better not to have a core.
Vacuum sealing molding of application range
Gray iron accessories: machine tool, machine tool with T-groove working platform, drilling machine base, rock wall drilling machine, crank, counterweight, forklift counterweight, gearbox, vortex furnace, bathtub, body, automobile flywheel, brake drum, pump impeller, pump head casting, pulley, etc
Ductile iron: pipe fittings, valves, shaft shells, etc
Steel casting: valve, lining, bolster, rear axle, cabinet, etc
However, some castings with complex geometry need to be combined with other processes, such as resin sand, coated sand and disappearing foam, and it is feasible to solve complex castings which are difficult to cover.
The vacuum pump system used in vacuum forming process includes vacuum pump, vacuum tank, filter tank and pipeline. When designing and forming the vacuum pump system, it is necessary to prevent dust or fine sand from invading the vacuum pump and affecting its performance. There are two types of vacuum pumps for modeling, wet and dry. In Japan, it is usually installed on the ground. For lamination, molding and casting, the wet pump is a wet pump, i.e. a water ring vacuum pump, which is sealed with water and used for road driving for casting. Pump. The selection of pump vacuum and pumping capacity is the key to the success of the model. Generally, the highest vacuum degree in production is about 66.7kpa, and the rotary vane vacuum pump can meet the requirements.
Rotary vane vacuum pump are as follows of features
1. Low noise, low vibration, long life, fixed magnet, safe and convenient;
2. It can be equipped with stainless steel oil mist filter, independent oil tank design and oil mist collector to prevent oil mist from scattering in the air and reduce air pollution in the laboratory;
3. It can be used in high flow, medium and high vacuum in laboratory, such as vacuum drying oven, vacuum filtration, vacuum oven, centrifugal concentrator, etc.
The rotary vane vacuum pump can remove the dry gas in the sealed container, and a certain amount of condensable gas can be removed if the gas stabilizer is installed. However, it is not suitable for removing gases with excessive oxygen, corrosive to metal, chemical reactivity to pump oil and containing fine dust.