Method for producing a hollow valve with an optimised interior stem geometry for internal combustion engines

Abstract

A method for producing a valve body of a hollow valve with optimised interior stem geometry includes a preform with a valve plate and a tubular wall surrounding a cavity. Flow forming the tubular wall over a flow-forming mandrel, which is inserted into the cavity to enlarge a length of the tubular wall. An interior area of the tubular wall is embossed with a structure either due to the fact that the flow-forming mandrel is a structuring mandrel having a surface structure, or alternatively, because the method includes a further step of reducing an outer diameter of the tubular wall by swaging or drawing and ironing over a structuring mandrel. Furthermore, a hollow valve is produced by this method.