| 摘要 |
A fuel injector includes a spool control valve, a plunger which moves in a fuel pressure chamber between retracted and full stroke positions. The fuel injector may include a spill port for spilling fuel from the fuel pressure chamber, the spill port being open at the start and closed by the translating motion of the plunger to delay the start of injection. The fuel injector chamber may further include a control port which is closed at the start of plunger motion and is opened by the plunger to connect the pressure chamber to a needle back chamber to bias the needle valve closed. The needle back chamber becomes isolated from the pressure chamber by further movement of the plunger and includes a pressure control passage to allow the pressure therein to decay upon control port closure, thereby effecting split injection or rate shaping. |
