Single dump single solenoid fuel injector
AssigneeThe Bendix Corporation
InventorsAlbert E. Sisson, Edward J. Hayes
Life of this patent
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Abstract
A unit injector having a mechanically driven piston and a remotely situated metering piston situated in a bore. The interplunger volume defining a timing chamber and the volume below the metering piston defining a metering chamber. The injector further including a single electrically responsive valve for controlling the functions of injection timing and fuel metering and a single dump port fabricated in the walls of the bore for relieving the fuel pressure on the timing chamber which correspondingly permits the pressure of fuel in the metering chamber to be decreased.
Claims7
A fuel injector for an internal combustion engine comprising:
- a body having an axially extending bore, a pumping piston and a remotely positioned metering piston positioned within said bore for axial movement therein;
- a timing chamber defined within said bore between the pumping piston and the metering piston and a metering chamber defined between the metering piston and the lower portion of the bore;
- a first fuel passage having an electronically controlled valve situated therein for receiving pressurized fuel and for transmitting the fuel to the timing chamber and for establishing, when closed, a hydraulic link between said pumping piston and said metering piston;
- a second fuel passage for receiving pressurized fuel and for transporting the received fuel to the metering chamber;
- a pressure regulator situated in said second fuel passage for regulating the fuel pressure within said metering chamber at a predetermined level between the pressure level of said received pressurized fuel and the pressure level established in said timing chamber during the interval when said valve is closed and said pumping piston is retracting, said pressure regulator including means for preventing reverse fuel flow from the metering chamber to said second fuel passage;
- a spring chamber situated remote from the metering chamber;
- nozzle means situated remote from said metering chamber and partially extending into said spring chamber for selectively releasing fuel therefrom;
- biasing means located within said spring chamber for biasing said nozzle means in a closed position during non-injecting modes of operation;
- fuel passage means for providing a means for relieving pressure within the timing chamber thereby breaking said hydraulic link as said metering piston uncovers said fuel passage means as it is moved into said metering chamber under the influence of said pumping piston and for developing a hydraulic biasing force to further bias said nozzle means toward a closed condition to terminate the injection of fuel therefrom.
Dependencies are inferred from the claim text.