Injection nozzle

摘要

An injection nozzle comprising a nozzle body provided with a bore within which a valve needle is moveable, the valve needle being engageable with a valve seating to control fuel delivery through a set of nozzle outlets, said nozzle outlets including respective entry openings defined in a wall of a sac volume of the nozzle body, wherein the valve needle includes a first valve region, a second valve region and a seat region defined by a transition between the first and second valve regions which seats against the valve seating when the nozzle is in a non-injecting state. The valve needle comprises a third valve region adjacent the second valve region, the third valve region having an outer surface defining a curved profile, the end of the outer surface terminating substantially in alignment with the entry openings when the valve needle is engaged with the valve seating.

主权项

1. An injection nozzle for an internal combustion engine, the injection nozzle comprising:
a nozzle body provided with a bore within which a valve needle is moveable along an axis, the valve needle being engageable with a valve seating to control fuel delivery through a set of nozzle outlets, wherein the valve seating transitions into a sac volume of the nozzle body defined by a steeply walled portion located at the very bottom of the bore, said nozzle outlets including respective entry openings defined in a wall of the sac volume, wherein the valve needle includes a first valve region, a second valve region and a seat region defined by a transition between the first and second valve regions and which seats against the valve seating when the nozzle is in a non-injecting state, the valve needle comprising a third valve region, adjacent the second valve region, the third valve region having an outer surface defining a curved profile, the end of the outer surface terminating in alignment with a plane passing through the centers of the entry openings, said plane being perpendicular to the axis, when the valve needle is engaged with the valve seating, wherein the outer surface (65) of the third valve region is spaced a distance (L) from the entry openings of the nozzle outlets of between 10% and 30% of the entry diameter (D) of the sac volume.