| 摘要 |
The invention relates to a fuel-injection nozzle (1) comprising an annular chamber (8) that surrounds a valve needle (6) in a bore (3), said chamber being divided into an upstream sub-chamber (8a) and a downstream sub-chamber (8b), which extends up to the valve seat surface, by a throttle ring (9) that comprises at least one throttle opening (12). At least one section of the throttle ring (9) is carried along by an axial displacement of the valve needle (6) in opposition to the action of a restoring force. According to the invention, the throttle ring (9) lies permanently against the bore wall (11), sealing the latter and has a sealing edge (14) that co-operates with the valve needle (6) and can be axially deflected. The valve needle (6) in the annular chamber (8) comprises a ring collar (13) that engages behind the throttle ring (9) in the closing direction of the valve needle (6). The sealing edge (14) lies against said collar until a specific opening length of stroke (h<SUB>1</SUB>) has been attained by the valve needle (6). Once said opening length of stroke (h<SUB>1</SUB>) has been attained, the ring collar is lifted from the sealing edge (14), forming an additional opening cross-section that interconnects the two sub-chambers (8a, 8b). |
