Abstract: A precision forming method of a high-efficiency and near-net hollow valve blank of an engine is provided, wherein the precision performing is realized by the cross wedge rolling mold, under the rolling the metal tubing for the valve deforms, with a middle part sunken and two ends elongating, the middle part forms a stem part of a hollow valve, the two ends form disk parts to be machined, and the connection sections between the disk parts and the stem part form neck parts having arced concave faces and a frustoconical lateral face in structure, achieving better consistency among the acquired hollow valve blanks. The disk part of each acquired hollow valve preformed blank is machined by the die-forging forming mold that is matched with the disk structure of the manufactured hollow valve, the hollow valve preformed blank is directly placed in the cavities of the die-forging forming mold for forging.

Abstract: A precision forming method of a high-efficiency and near-net hollow valve blank of an engine is provided, wherein the precision performing is realized by the cross wedge rolling mold, under the rolling the metal tubing for the valve deforms, with a middle part sunken and two ends elongating, the middle part forms a stem part of a hollow valve, the two ends form disk parts to be machined, and the connection sections between the disk parts and the stem part form neck parts having arced concave faces and a frustoconical lateral face in structure, achieving better consistency among the acquired hollow valve blanks. The disk part of each acquired hollow valve preformed blank is machined by the die-forging forming mold that is matched with the disk structure of the manufactured hollow valve, the hollow valve preformed blank is directly placed in the cavities of the die-forging forming mold for forging.