In low-pressure casting, the mold is placed in a closed holding furnace, and the cavity is connected to the metal in the furnace through a riser. During operation, compressed air is added to the furnace and molten metal will flow from the riser into the cavity. After the molten metal solidifies, the compressed air in the furnace is released, and the unsolidified metal flows back into the furnace from the riser.

The aluminum hub and blades in the torque converter core adopt low-pressure casting, which has four advantages: compact low-pressure casting structure, good mechanical properties; high process output. According to statistics, the pass rate of low-pressure die casting process isMore than 93%, the gravity casting productivity of the same product is between 70% and 80%; the production efficiency is high, the production efficiency of the same product die-casting process is three times that of gravity casting; the surface is smooth, which will reduce the machining allowance.

The following to introducelow pressure castingofProduction process:

1. Mold inspection. The paint should be cleaned before using the mold. After the end of the production cycle, if the paint fails or the surface is not smooth, you need to use a grinding wheel for grinding, and then clean the aluminum shavings of the ejector rod and clean the exhaust plug.

2. The working temperature of the baking mold is (360±10)℃, so the mold should be baked to the working temperature before low pressure casting.

3. Coating: When the mold is heated to 300°C, spray the coating. The coating must be uniform and not sag. The coating mainly serves the following functions: preventing the aluminum alloy from corroding the cavity and prolonging the life of the mold for low pressure casting. Secondly, the aluminum alloy is prevented from adhering to the cavity or the parting surface, so that the production can be carried out continuously and rapidly. The coating makes the cavity have a layer of heat insulation protection structure, so that the molten metal can flow into the cavity smoothly, reduce the flow resistance of molten aluminum, and improve the filling performance of molten metal.

4. Set process parameters. The process parameters of low pressure casting are mainly the temperature of molten aluminum, the pressure speed and pressure setting of the equipment. These three factors will directly affect the quality of low-pressure castings. If the process parameters are set incorrectly, defects such as sand adhesion and insufficient pouring will result. Therefore, parameter setting is very important for low pressure casting.

5. Low pressure casting pouring.