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.