Extruding and die-casting process for electric steering shell with high strength and low porosity

Abstract

The invention relates to an extruding and die-casting process for an electric steering shell with high strength and low porosity. The die-casting method comprises the following steps: melting materials, fixing a mold with a local extruding device to a die-casting machine, carrying out extrusion and die casting when the materials are semi-solidified, and carrying out final die casting to obtain a product. The extruding and die-casting process has the advantages that in structure design of the mold, the local extruding device is adopted, so as to extrude the connecting parts (parts where the die casting pressure cannot be transferred) between holes with thicker walls; a special mold is adopted for designing the structure, when mixed materials are filled into a cavity and then take on a semi-solidified state, an extruding pin is pushed by an oil cylinder to extrude the connecting parts between the holes with thicker walls tightly, so that the defect of hole shrinkage is avoided, and the porosity can be controlled within 3%; the internal structure of a die-casting part is finer, so that the strength of the product is greatly improved.

Description

technical field [0001] The invention relates to the field of die-casting, and more particularly relates to a extrusion die-casting process of a high-strength and low-porosity electric steering housing. Background technique [0002] With the popularization of electric power steering systems, the production capacity requirements of steering gear housings are also getting higher and higher. At the same time, under the influence of cost reduction and weight reduction in the automotive market, the use of die-casting aluminum alloys and the weight design of parts tend to maintain a reduction While being heavy, higher product strength is required to ensure that the car is lightweight and has higher safety performance. The above-mentioned technical standards are reflected in the casting quality of the steering gear casing, that is, the internal porosity of the key stress-bearing parts is below 3%, and there is no shrinkage cavity at the same time. [0003] In the prior art, the str...

AI Technical Summary

Problems solved by technology

However, due to the lightweight design, most of the wall thickness is about 4mm, which makes the connection between the local holes of the product have a problem that the local wall thickness is too large, so that the die-casting gate cannot transfer the pressurization during die-casting to the holes. The connection part, resulting in substandard porosity and shrinkage cavity

Such products have a low pass rate, poor internal quality, and reduced safety

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