摘要 |
To improve the strength properties of the seat face (4) of a nozzle body (1), which seat face cooperates with the tip of a nozzle needle (2) and contains the mouths of fuel injection holes (5), it is proposed to effect a plastic deformation of the nozzle body (1) beyond the yield point adjacent to the seat face (4) for the nozzle needle in such a manner tha the plastic deformation is effected only in part of the wall thickness of the nozzle body adjacent to the seat face (4) for the nozzle needle. To effect that plastic deformation, a mandrel consisting particularly of the nozzle needle (2) is used as a tool. Adjacent to the seat face (4) for the nozzle needle that mandrel has preferably a multiconical or crowned shape. The apparatus for carrying out the process comprises an abutment (10) for the nozzle body (1) and a hydraulic press (11), by which a nozzle needle (2) can be forced against the associated seat face (4) (FIG. 4 ). |