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

Abstract

The invention relates to an extrusion die-casting process of a high-strength and low-porosity electric steering housing. The die-casting method includes melting materials, fixing a mold with a local extrusion device to a die-casting machine, and performing extrusion die-casting when the materials are semi-solidified. And the final die-casting is carried out to obtain the product. The extrusion die-casting process of the present invention adopts a local extrusion device in the design of the mold structure, that is, to extrude the connection part (the part where the die-casting pressure cannot be transmitted) between the holes with thicker walls. A special mold design structure is adopted. When the mixed material is in a semi-solidified state after filling the cavity, the connection part between the thicker holes is squeezed tightly by pushing the extrusion pin through the oil cylinder, so as to avoid shrinkage cavity defects and the porosity can be controlled. It is within 3%; and it makes the internal structure of the die-casting parts finer and greatly improves the product strength.

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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