| 摘要 |
<p>A fuel injector (100) for use in an internal combustion engine comprising an injection nozzle (118) having a nozzle body (120) provided with a nozzle bore (130), a first valve needle (136) received within the nozzle bore and being engageable with a first seat region (137) to control fuel delivery through a first set of nozzle outlets (126), and a second valve needle (138) received within a valve bore (140) provided in the first valve needle and being engageable with a second seat region (144) arranged to control fuel delivery through a second set of nozzle outlets (128). A control chamber (184) for fuel is provided, preferably at least in part, between the first valve needle and the second valve needle, wherein movement of the first valve needle is responsive to fuel pressure in the control chamber, and wherein movement of the second valve needle is coupled to a first actuator arrangement (159), such that when the second valve needle lifts away from the second seating region, a fuel flow path is established between the control chamber and the second set of nozzle outlets. The fuel injector further includes a second actuator arrangement (200) that is operable to control fuel flow into the control chamber thereby regulating fuel pressure within the control chamber and, thus, movement of the first valve needle.</p> |
