Verfahren zum Herstellen eines Ventilsitzes in der Querwand einer Düse

摘要

A method of producing a cylindrical nozzle incorporated in a fuel injection valve for an internal combustion engine including the steps of: setting a cylindrical nozzle blank on a second die so that a lower bottom face of the cylindrical nozzle blank rests on the second die; pressing a punch into the cylindrical nozzle blank while being guided along the inner wall face of the cylindrical nozzle blank; pressing the punch onto a bottom of the cylindrical nozzle blank to induce plastic flow, thereby transfer forming a seat portion at a center on the upper bottom face of the cylindrical nozzle blank; removing a projection formed on the lower bottom face of the cylindrical nozzle blank due to the plastic flow; boring a nozzle injection hole at the center of the transfer formed seat portion of the projection removed cylindrical nozzle blank; and hardening the bored cylindrical nozzle blank.