METHOD FOR PRODUCING A HOLLOW ENGINE VALVE

摘要

The present invention provides a method for producing a hollow engine valve, with which the production process can be simplified and the processing precision can be improved. To this end, the present invention provides a method for producing a hollow engine valve (1) which is provided with a valve main body (10) in which a hollow hole (10c) is formed along a valve umbrella part (10a) and a hollow shaft part (10b), wherein a solid round bar (11) forming the material of the valve main body (10) is moulded to a semi-finished article (12) by means of a single hot-forging process, the semi-finished article (12) is subjected to rotary swaging whereby the semi-finished article (12) is moulded into a semi-finished article (13), the semi-finished article (13) is subjected to necking whereby the semi-finished article (13) is moulded into the valve main body (10), and a shaft end sealing member (20) is joined to the end part of the hollow shaft part (10b) of the valve main body (10) .