A fuel injection nozzle for internal combustion engines has a holder (11) with a projecting fixed nozzle needle (15) with the end section (17) bearing a valve cone (18) of which an annular valve diaphragm (31) acts in the manner of a valve. The outer edge section (41) of the valve diaphragm (31) is clamped against the holder (11) by a union nut (32), whereby the edge (49) surrounding the aperture (39) is spring-loaded against the valve cone (18). In order to keep the stresses during the bending-generated movement of the valve diaphragm (31) low over their entire range, the valve diaphragm (31) has a bulge (40) against the direction of movement. The bulge (40) preferably consists of an annular region (42) with a steep inclination (α) adjacent the clamped outer edge section (41) and an annular region (43) extending to the aperture (39) with a shallow inclination (β). The bulge (40) may also be cone or dome shaped. To limit the travel of the valve diaphragm (31) there is a travel abutment disc (33) which is clamped to the holder (11) together with the valve diaphragm (31) by the union nut (32). The shape of the injection jet is influenced by the shape of the end section (17) of the nozzle needle (15) and the through aperture (51) in the travel abutment disc (33).

Indra Jaromir

Papers

Einspritzvorrichtung fuer brennkraftmaschinen