| 摘要 |
A fuel injection apparatus for an internal combustion engine comprises a fuel feeding device for feeding intermittently a high pressure fuel to a fuel injection valve apparatus for injecting fuel to the engine. The fuel injection valve apparatus comprises a valve housing formed with a fuel chamber and an injection orifice, and a needle valve element slidably disposed within the valve housing for opening and closing the injection nozzle orifice. The injection orifice is opened by the high pressure fuel supplied from the fuel feeding apparatus, and is closed by a biasing means such as a spring in association with a hydraulic thrusting means which accumulates the high pressure fuel to thrust the needle valve element toward the injection orifice closing position thereby to accomplish a rapid termination of the fuel injection. The fuel feeding apparatus comprises a cylinder and a plunger. The cylinder has a feed hole , while the plunger has a notch having a straight leading edge. At the end of the fuel feeding stroke of the plunger, the feed hole is communicated with the plunger chamber through the notch with the feed hole, whereby the fuel within the plunger chamber returns to a fuel supply. Thus, the fuel pressure counteracting the injection orifice closing operation is abruptly decreased to allow a rapid termination of the fuel injection.
|
