What three aspects are involved in the design requirements of die castings
Posted by Admin
2022-03-04
(1) Requirements for design ribs of castings:
The function of the rib is to improve the strength and rigidity of the part after the wall thickness is reduced, to prevent the shrinkage and deformation of the casting from being reduced, and to avoid the deformation of the workpiece when it is ejected from the mold. , the thickness of the die-casting rib should be less than the thickness of the wall where it is located, generally taking 2/3 to 3/4 of the thickness of the location;
(2) Wall thickness requirements for casting design:
The wall thickness of die castings (usually called wall thickness) is a factor of special significance in the die-casting mold process. Analysis of mold temperature gradient, the effect of pressure (final specific pressure), length of mold retention time, casting ejection temperature, and operating efficiency;
a. The thicker wall thickness of the parts will significantly reduce the mechanical properties of the die castings, and the thin-walled castings have good compactness, which relatively improves the strength and pressure resistance of the castings;
b. The wall thickness of the casting should not be too thin. If it is too thin, it will cause poor aluminum liquid filling, difficulty in forming, poor welding of the aluminum alloy, and defects such as cold insulation on the surface of the casting, which will bring difficulties to the die-casting process; The increase in the number of internal pores, shrinkage holes, and other defects increases. Therefore, on the premise of ensuring sufficient strength and rigidity of the casting, the wall thickness of the casting should be reduced as much as possible and the thickness of the section should be kept uniform. In order to avoid defects such as shrinkage, the casting should be The thickness of the thick wall should be reduced (material reduction), and ribs should be increased; for large-area flat-type thick-walled castings, ribs should be set to reduce the wall thickness of the casting;
(3) The shape and structure requirements of die castings:
a. Eliminate internal undercuts;
b. Avoid or reduce core pulling parts;
c. Avoid core crossing;
A reasonable die-casting structure can not only simplify the structure of the die-casting mold, reduce the manufacturing cost, but also improve the casting quality.