Design requirements for die castings:

   (1) The shape and structure requirements of die castings:
a. Eliminate internal undercut;
b. Avoid or reduce core pulling parts;
c. Avoid cross cores; reasonable die casting structure can not only simplify the structure of die casting mold, reduce manufacturing cost, but also improve the quality of castings.

   (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 process. The wall thickness is closely related to the entire process specification, such as the calculation of filling time, the selection of gate speed, the calculation of solidification time, and the mold Analysis of temperature gradient, the effect of pressure (final specific pressure), the length of mold retention time, the level of casting ejection temperature and operating efficiency.
a. Part wall thickness is too thick, which will significantly reduce the mechanical properties of die castings, thin-walled castings have good compactness, and relatively improve the strength and pressure resistance of castings;
b. The wall thickness of the casting should not be too thin. Too thin will cause poor filling of molten aluminum, difficulty in forming, poor welding of aluminum alloy, defects such as cold barriers on the surface of the casting, and difficulties in the die casting process; die castings vary with the wall thickness In order to avoid defects such as shrinkage porosity, the thickness of the castings should be reduced as much as possible and the thickness of the cross-section should be kept uniform on the premise of ensuring that the castings have sufficient strength and rigidity. The thickness of the thick wall should be reduced (material reduction) and ribs should be increased; for large-area flat thick-walled castings, ribs should be set to reduce the wall thickness of the casting.
According to the surface area of the die casting, the reasonable wall thickness of the aluminum alloy die casting is as follows:
Die casting surface area/mm2 wall thickness S/mm
≤25 1.0～3.0
＞25~100 1.5~4.5
＞100~400 2.5～5.0
＞400 3.5～6.0

   (3) Requirements for design ribs of castings:

The function of the ribs is to increase the strength and rigidity of the parts after the wall thickness is thinned, to prevent the shrinkage and deformation of the castings, and to avoid the deformation of the workpiece when it is ejected from the mold. It is used to act as an auxiliary circuit (metal flow path) during filling. , The thickness of the die-casting ribs should be less than the thickness of the wall where it is located, generally 2/3~3/4 of the thickness at that location;

   (4) Fillet requirements for casting design:

Any wall-to-wall connection on die-casting parts, regardless of right angles, acute angles or obtuse angles, blind holes and groove roots, should be designed with rounded corners, and rounded corners should not be used only when it is expected to be the parting surface. , The remaining parts must generally be rounded corners. The rounded corners should not be too large or too small. Die castings that are too small are prone to cracks, and too large are prone to loose shrinkage holes. The rounded corners of die-castings are generally taken as: 1/2 wall thickness ≤ R ≤ wall Thick; the role of rounded corners is to help the flow of metal, reduce eddy or turbulence; to avoid the presence of rounded corners and cause stress concentration and cracking; when the parts are to be electroplated or coated, the rounded corners can be obtained Uniform coating to prevent deposition at sharp corners; can prolong the service life of the die-casting mold, and prevent corner chipping or cracking due to the sharp corners of the mold cavity;

   (5) Casting slope requirements for die casting design:

The role of the slope is to reduce the friction between the casting and the mold cavity, and it is easy to take out the casting; to ensure that the surface of the casting is not strained; and to extend the service life of the die casting mold.