The ratio of the volume of the axle housing divided by the heat transfer surface area is called the solidification time of the axle housing, also known as the solidification coefficient, referred to as modulus. The calculation formula of axle housing modulus is as follows:
M — modulus (CM);
V — volume (cm3);
A — heat dissipation surface area (cm 2).
According to the overall dimension data of the axle housing, the modulus of the axle housing is calculated as follows:
Riser feeding design is an important part ofdesign. Its purpose is to ensure the material of axle housing, meet the requirements of axle housing use and corresponding acceptance conditions, and consider the feeding economy. The riser of the axle housing should not be placed on the hot spot, but should be set near the hot spot.
Using viewer in ProCAST simulation software It can be seen from the module that shrinkage casting defects are more likely to occur in the flange connection end and top surface of the axle housing poured by the closed gating system of scheme 1 and scheme 3 semi closed gating system. The reason for this defect is that during the solidification process, excessive molten metal flow scours the sand wall to form hot spots, and forms an isolated liquid phase zone during solidification, If the effective liquid metal feeding is not enough, the porosity and shrinkage cavity will be formed finally.
Design of the riser of the axle housing:
The riser design of the axle housing is based on the sectional proportion method. The calculation formula for riser diameter (4-3) and height is as follows:
Where σ is the wall thickness at the hot spot of the axle housing.
The case adopts limit value to simulate the influence of different riser sizes on the axle housing
Riser diameter: Dr = 22 = 44 mM,
Riser height: HR = 1.5dr = 66 mm,
Combined with relevant data and the overall dimensions of the axle housing, the riser diameter is 80 mm and the riser height is 150 mm.
The riser modulus is about: M = 18.75mm > 9.7mm (axle housing modulus).
Through the above calculation, it is known that the riser modulus is greater than that of the axle housing, which meets the requirements.