(1) Determination of specific shape and size of riser of wheel hub in investment casting sand casting
According to the specific shape of impeller investment casting sand casting hub, the standard waist round open riser is selected, and its shape and size are shown in the figure.
Modulus and shrinkage of riser in investment casting sand casting of impeller ε After determination, the specific size of the required riser can be found out from the table data of riser in investment casting sand mold casting of relevant standard impeller according to the type and shape of riser.
M hub = 2.48 according to the data:
a=120mm b=180mm h=150mm
Considering the width of the hub, the height of the flange diameter is set to be 10mm,
Impeller investment casting – sand casting, the diameter of the flange is the same as the width of the hub, which is 50mm.
Impeller investment casting – sand casting riser weight is about 25kg, when ε＝ At 6%, the maximum volume of castings that can be fed is VC = 4.3 × 103cm3
(2) Calculation of feeding capacity of riser in impeller investment casting sand casting hub
Half of the width of impeller investment casting sand casting hub and spoke (inner part of the circle with a radius of 14.65cm) is fed by the riser of impeller investment casting sand casting hub part. The required feeding casting volume of hub part = (14.652-8.52) × three point one four × 3+(8.52-3.52) × three point one four × 13.8 =3.94 × 103cm3﹤VC=4.3 × 103cm3,
Therefore, only one riser needs to be set on the impeller investment casting – sand casting hub.