| 摘要 |
An injection nozzle for an internal combustion engine, the injection nozzle including an outer valve needle (14) which is engageable with an outer valve seating (30) so as to control injection through a first nozzle outlet (20), an inner valve needle (22) which is movable within the outer valve needle (14) and engageable with an inner valve seating (34) so as to control injection through a second nozzle outlet (26), and coupling means (22b, 122; 22b, 222) for coupling movement of the outer valve needle (14) to the inner valve needle (22) in circumstances in which the outer valve needle (14) is moved away from the outer valve seating (30) beyond a predetermined amount (L), thereby to permit fuel injection through both the first and second nozzle outlets (20, 26). The outer valve seating (30) defines first and second seats (56, 58) for the outer valve needle (14), wherein co-operation between the outer valve needle (14) and the first seat (56) controls fuel flow between a first delivery chamber (46) and the first nozzle outlet (20) and co-operation between the outer valve needle (14) and the second seat (58) controls fuel flow between a second delivery chamber (49) and the first nozzle outlet (20). The second delivery chamber (49) communicates with the first delivery chamber (46) by way of a supplementary flow path (24, 47) defined, at least partially, within the outer valve needle (14). The coupling means includes a resilient member (60) carried by the outer valve needle (14), the resilient member (60) being brought into engagement with the inner valve needle (22) following movement of the outer valve needle (14) beyond the predetermined amount (L) so as to cause the inner valve needle (22) to move together with the outer valve needle (14). <IMAGE> <IMAGE> |
