Fuel injector for fuel system having damping adjustment valve
AssigneeCaterpillar Inc.
InventorAndrew Ogden Marrack
Life of this patent
Estimating the term…
Abstract
A fuel injector for a fuel system in an internal combustion engine includes an injector housing, a direct-operated nozzle check movable within the injector housing, a check biasing spring within a spring chamber and biasing the nozzle check toward the closed position. The injector housing defines a damping control space, an always-open vent from the spring chamber to the damping control space, and a second vent from the spring chamber to the damping control space. The fuel injector further includes a hydraulically actuated damping adjustment valve movable responsive to a pressure of fuel supplied to the fuel injector between a higher damping position blocking the second vent, and a lower damping position where the second vent is open.
Claims20
A fuel injector for an engine comprising:
- an injector housing having formed therein a fuel inlet, a nozzle passage extending to a plurality of nozzle outlets, a check control chamber, and a spring chamber;
- a direct-operated nozzle check movable between a closed position blocking the plurality of nozzle outlets, and an open position;
- a check biasing spring within the spring chamber and biasing the direct-operated nozzle check toward the closed position;
- the injector housing defining a damping control space fluidly connected to the fuel inlet, an always-open vent from the spring chamber to the damping control space, and a second vent from the spring chamber to the damping control space;
- and
- a damping adjustment valve movable between a higher damping position blocking the second vent, and a lower damping position where the second vent is open.
A fuel system for an engine comprising:
- a variable pressure fuel supply;
- a fuel injector including a direct-operated nozzle check, a biasing spring for the direct-operated nozzle check, and a damping adjustment valve;
- the fuel injector having formed therein a fuel inlet and a damping control space each fluidly connected to the variable pressure fuel supply, a spring chamber receiving the biasing spring, and a plurality of vents connecting between the spring chamber and the damping control space;
- and
- the damping adjustment valve being hydraulically-actuated between a higher damping position where the damping adjustment valve blocks one of the plurality of vents, and a lower damping position where the damping adjustment valve does not block the one of the plurality of vents and at least one of the plurality of vents is open.
A method of operating a fuel system for an engine comprising:
- opening a nozzle check in a fuel injector a first time to spray fuel from the fuel injector;
- venting fuel through each of a first vent from a spring chamber in the fuel injector and a second vent from the spring chamber during the opening a nozzle check in a fuel injector a first time;
- varying a pressure of fuel supplied to the fuel injector;
- moving a damping adjustment valve from a lower damping position where each of the first vent and the second vent is open, to a higher damping position where the damping adjustment valve blocks the second vent but not the first vent, based on the varying a pressure of fuel;
- opening the nozzle check a second time to spray fuel from the fuel injector;
- venting fuel through the first vent but not the second vent during the opening the nozzle check a second time;
- and
- damping the opening of the nozzle check a second time based on the venting fuel through the first vent but not the second vent.
Dependencies are inferred from the claim text.