Extrusion die-casting method of a thin-walled aluminum alloy automobile engine pump body cover

Abstract

The invention relates to an extrusion die casting method for a thin-wall aluminum alloy automobile engine pump body cover. The method is suitable for obtaining the automobile engine pump body cover which is good in gas tightness and compactness, high in product qualified rate, complex in shape structure and thin in wall. The extrusion die casting method comprises an extrusion die casting step, wherein a quantitative pouring cup is adopted to convey aluminum base alloy melt into a material cylinder chamber of a die casting machine from a heat preservation furnace; a punch of the extrusion die casting machine smoothly propels the aluminum base alloy melt into a die cavity; the process of propelling the aluminum base alloy melt comprises three stages in sequence: according to the first stage, the punch is propelled at extrusion die casting speed, the propelling stroke accounts for 50 percent to 60 percent of the full stroke, and therefore air in a material cylinder runs away, the alloy melt slowly enters the middle segment of the die cavity, and the air runs away and air wrapping is reduced; according to the second stage, the punch is propelled at the die casting speed of a horizontal die casting machine, the propelling stroke accounts for 33 percent to 43 percent of the full stroke, pressing injection is rapidly carried out, and therefore mold filling is completely carried out on the product, and the cold shut is solved through rapid forming; and according to the third stage, pressure maintaining and feeding are carried out, and therefore crystalline grains are compacted, and a casting workblank is obtained.

Description

technical field [0001] The invention relates to the field of casting, in particular to an extrusion die-casting method for thin-walled aluminum alloy parts, in particular to an extrusion die-casting method for automobile engine pump body covers, cylinder heads, cylinder covers and the like. Background technique [0002] In order to save energy and reduce consumption, reduce exhaust emissions, improve driving comfort and vehicle mechanical properties, cars are now developing in the direction of lightweight. From the perspective of structural materials, the main means to achieve vehicle lightweight is to replace traditional materials with lightweight materials with high specific performance (specific strength and specific stiffness). The aluminum alloy material has the characteristics of low price, high specific performance, and outstanding damping and vibration reduction performance. The use of aluminum alloys in automobile structures can reduce vehicle weight and fuel consu...

AI Technical Summary

Problems solved by technology

However, conventional high-pressure die-casting in a cold chamber cannot effectively solve the problems of more air bubbles and lower compactness of the product.

[0005] The use of aluminum alloy extrusion casting to produce the above-mentioned thin-walled aluminum alloy automobile engine pump body cover also has limitations. First, the slow injection speed leads to insufficient filling capacity, and complex castings cannot be well filled; second, the axial (thickness) ) with low dimensional accuracy

That is, the advantage of traditional squeeze casting is that it can effectively solve the airtightness problem of the die casting machine, and can solve the conditions of porosity and shrinkage porosity from the source, but the disadvantage is that the filling capacity is insufficient, and complex parts and thin-walled parts cannot be effectively formed.

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