The design of the die casting must take into account the wall thickness of the die casting, the casting fillet and the draft angle of the die casting, the reinforcement ribs, the minimum distance between the casting hole and the hole to the edge on the die casting, the rectangular hole and groove on the die casting, the die casting There are seven aspects of the machining allowance of inserts and die castings in the parts.

Casting fillet design specification: Usually, each part of the die casting should have a fillet (except at the parting surface), which can make the metal flow smoothly when filling, and the gas can be easily discharged and can avoid cracks caused by sharp angles. For die castings that require electroplating and finishing, filleted corners can be uniformly coated to prevent paint build-up at sharp corners. The fillet radius R of the die casting should generally not be less than 1mm, and the minimum fillet radius is 0.5mm.

Design specifications of inserts in die castings: First, the number of inserts on the die castings should not be too much; secondly, the connection between the inserts and the die castings must be firm, and at the same time, the inserts are required to be slotted, raised, knurled, etc.; Thirdly, the inserts must avoid sharp corners to facilitate placement and prevent the stress concentration of the castings. If there is serious galvanic corrosion between the castings and the inserts, the surface of the inserts needs to be protected by plating; finally, castings with inserts should be avoided. Heat treatment to avoid volume change due to phase transition of the two metals, loosening the insert.

Design specification for casting fillet of die castings

Design specifications for wall thickness of die castings: Thin-walled die-castings have higher strength and better compactness than thick-walled die-castings. In view of this, the design of die-casting parts should follow the following principles: On the premise of ensuring that the castings have sufficient strength and rigidity The lower wall thickness should be reduced as much as possible, and the wall thickness should be kept uniform. The practice has proved that the wall thickness design of die-casting parts is generally 2.5-4mm, and parts with wall thickness exceeding 6mm should not be produced by the die-casting process. The performance of the influence of too thick and too thin walls of die castings on the quality of the castings: If the walls of the castings are too thin in the design, the metal welding will not be good, which will directly affect the strength of the castings, and at the same time will cause difficulties in forming; the walls are too thick or severely uneven On the other hand, with the increase of wall thickness, defects such as pores and shrinkage in the casting also increase, which will also reduce the strength of the casting and affect the quality of the casting.

Design specifications for machining allowances of die castings: In general, due to the limitations of the die casting process, when certain dimensional accuracy, surface roughness, or geometric tolerances of die castings cannot meet the requirements of the product drawings, enterprises should first consider using Such as correction, polishing, extrusion, shaping and other finishing methods to repair, when finishing can not completely solve these problems, some parts of the die casting should be machined. It should be noted here that, When machining, a small machining allowance should be considered, and at the same time, try to use the surface that is not affected by the parting surface and active forming as the blank reference surface, so as not to affect the machining accuracy.

Design specifications for the demoulding slope of die castings: When designing die castings, there should be a structural slope on the structure. When there is no structural slope, there must be a process slope for demolding where necessary. The direction of the inclination must be consistent with the release direction of the casting.