The top duckbill riser technology is based on the design theory of direct practical riser technology, which is mainly used in the casting production of small and medium-sized cylinder block iron castings. The feature of top duckbill riser technology is long riser neck, that is, the ratio of height to diameter of riser neck is very large. The advantages of this method are that there is no contact hot spot, the thermal interference of riser to cast iron castings can be almost ignored, and the cleaning of late casting is convenient. The relationship between riser diameter (unit: mm), riser height (unit: mm), riser neck diameter (unit: mm), riser neck height (unit: mm) and mass of cylinder block iron castings (unit: kg) in production were counted.
In the actual casting production of cylinder block iron castings, the shape of duck beak riser is generally cylindrical. Taking the casting mass (unit: kg) as the classification standard, the selection of diameter D (unit: mm) is related to the wall thickness t (unit: mm), that is, d = KT and the value of the relationship coefficient K.
The value of height diameter ratio coefficient β is between 1.00 and 1.54, that is, the relationship between riser height h and riser diameter D is
The diameter D (unit: mm), height L (unit: mm) and casting wall thickness (unit: mm) of riser neck.
The section area ratio of gating system and the mass of cast iron (unit: kg) for top duckbill riser process.