Design points of die castings:
(a) the shape and structure of die casting requirements: A, remove the inner side concave; B, avoid or reduce the core position; C core structure and avoid cross; die casting structure can not only simplify the die, reduce the manufacturing cost, but also improve the quality of castings.
(two) the wall thickness of casting design requirements: die casting wall thickness (usually called the thickness) is an important factor in the casting process, the wall thickness and the whole process specifications are closely related, such as filling time calculation, ingate speed selection, solidification time calculation, mold temperature gradient analysis, pressure (final pressure) role, the length of time, die casting ejector and low operation efficiency of temperature; a partial thickness and the thickness of parts will make the mechanical properties of die casting of thin-walled castings decreased obviously, good compactness, relatively improve the casting strength and pressure resistance; B, wall thickness of casting not too thin, too thin will cause poor filling of liquid aluminum, forming difficulty, make Aluminum Alloy welding of casting surface is not good, easy to produce cold insulation defects, and die casting process difficulties; die castings with the wall thickness increasing, the porosity and shrinkage hole Defects, so if the casting has enough strength and stiffness under the premise, should try to reduce the thickness of the casting section and maintain uniform thickness, in order to avoid the defects such as shrinkage, thick wall of casting thickness should be reduced (less material), add ribs; for large thick wall plate casting, set reinforcement to reduce the wall thickness of casting; according to the casting surface area, reasonable wall Aluminum Alloy casting thickness as follows: die casting surface area /mm2 S thickness /mm = 251 ~ 3.0>25~1001.5 ~ 4.5>100~4002.5 ~ 5.0>4003.5 ~ 6.
(three) requirement of casting design bars:
The reinforcing effect is thin wall thickness change, in order to improve the strength and rigidity of the parts, to prevent and reduce the casting shrinkage deformation, avoid the workpiece ejection from the mold when deformed, filled with auxiliary circuit (via metal flow), die casting rib thickness should be less than the thickness of the wall. In general the thickness of 2/3~3/4.
(four) fillet requirements for casting design:
Die casting connection all wall and wall, right angle, acute angle or obtuse angle, regardless of the blind hole and groove of the root, should be designed with rounded corners, only when the estimated for the type of site, do not use the rounded connection, other parts must generally be rounded rounded, should not be too large or too small, too small die casting easy to crack, easy to produce excessive shrinkage porosity, casting wall thickness of fillet general: 1/2 = R = thickness; rounded effect is helpful for metal flow, reduce eddy turbulence; avoid the parts due to the presence of a fillet due to stress concentration caused by cracking; when the parts to the plating or coating, the fillet can obtain uniform coating, prevent corner deposition; can prolong the service life of die, not due to existence of the mold cavity angle caused chipping or cracking.