The automobile hub support is an important support of the rear suspension system of the car, one for the left and one for the right wheels, which is used to connect the rod system of the rear suspension frame, brake and shock absorber, and bear the alternating impact load when the car is running. The structure of hub support is complex, with the maximum wall thickness of 31.75 mm and the minimum of 4.75 mm, and the single piece mass of 6.9 kg. Because it needs to be connected with other automobile parts, there are many connecting holes on the parts, but they are not cast due to their small size. Only two connecting holes of outer bushing are cast through sand core. The three-dimensional part view of the hub support is shown in the figure.
According to the structural characteristics and application of high strength and Toughness Nodular Cast Iron automobile hub support casting, the production process and preliminary nodular cast iron process scheme are analyzed and designed.
The chemical composition, melting production, spheroidizing treatment and inoculation treatment of high strength and toughness pearlite ferrite based nodular cast iron were determined. According to the actual structure of nodular cast iron, the preliminary process design of nodular cast iron is carried out, which mainly includes the selection of modeling method and pouring position, the determination of parting surface and relevant process parameters, and the design of pouring and feeding system: the castings are produced by ordinary wet sand gravity casting method with two pieces in one box, and the pouring position is selected at the thick part of the upper surface where hot spots are most likely to occur, Adopt curved surface parting; The semi closed gating system is selected. Two side risers and one middle riser are used to feed the two castings. The riser is set between the casting and the sprue to make the nodular cast iron enter the mold through the riser, so that the riser has the effect of slag retaining while feeding the casting.