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US 12,078,136 B2Granted
Fuel injector nozzle assembly including needle having flow guiding tip for directing fuel flow
AssigneeCaterpillar Inc.
InventorsKenth I Svensson, Russell P Fitzgerald
Life of this patent
Estimating the term…
Abstract
A fuel injector includes a nozzle needle movable within an injector housing and including a flow guiding tip. The flow guiding tip includes an outer ramp surface, defining, in profile, a concave curve and a fuel trajectory line tangent to the concave curve and extending through a spray orifice inlet to direct fuel into the same. Related methodology is also disclosed.
Claims20
A fuel injector comprising:
- an injector housing defining a longitudinal axis and having formed therein each of a fuel inlet, a nozzle passage extending to a spray orifice having a spray orifice inlet and a spray orifice outlet, and a needle seat;
- a nozzle needle movable within the injector housing between a closed needle position blocking the spray orifice from the nozzle passage, and an open needle position, and including a seating surface in contact with the needle seat at the closed needle position, and a flow guiding tip;
- and
- the flow guiding tip including an outer ramp surface extending axisymmetrically around the longitudinal axis and defining, in profile, a concave curve originating at an axially inward location and terminating at an axially outward location, and a linear fuel trajectory line that is tangent to the concave curve at the axially outward location and extends from the axially outward location in a direction that is radially outward and axially outward of the flow guiding tip through the spray orifice inlet at the closed needle position.
1 more element
A fuel injector nozzle assembly comprising:
- a nozzle body including a needle seat, an end bulb, and a plurality of spray orifices formed in the end bulb and arranged at a plurality of spray orifice angular locations around a longitudinal axis;
- a nozzle needle movable relative to the needle seat, and including a seating surface in contact with the needle seat;
- a sac volume fluidly connected to each of the plurality of spray orifices is defined within the end bulb between the nozzle needle and the nozzle body;
- the nozzle needle further including a flow guiding tip having an outer ramp surface exposed to the sac volume and having a concave profile defining a fuel path extending, at each of the plurality of spray orifice angular locations, directly into the plurality of spray orifices;
- and
- the concave profile extending from an axially inward location to an axially outward location, and the flow guiding tip defining a width, between the axially inward location and the axially outward location, that is narrowest at a location coincident with a minimum point of the concave profile.
3 more elements
A method of operating a fuel system comprising:
- moving a nozzle needle in a fuel injector defining a longitudinal axis from a closed needle position closing a needle seat and blocking a sac volume from a nozzle passage in the fuel injector, to an open needle position where the needle seat is open;
- advancing a pressurized fuel through the sac volume from the nozzle passage to a plurality of spray orifices of the fuel injector based on the moving the nozzle needle;
- and
- impinging the pressurized fuel advanced through the sac volume upon a concave ramp surface of a flow guiding tip of the nozzle needle defining a plurality of linear fuel trajectory lines at each of a plurality of spray orifice locations, and each of the plurality of linear fuel trajectory lines extending away from the flow guiding tip in a direction that is radially outward and axially outward into a respective one of the plurality of spray orifices;
- and
- advancing at least some of the pressurized fuel impinged upon the concave ramp surface along the respective linear fuel trajectory lines directly into the plurality of spray orifices.
3 more elements
Dependencies are inferred from the claim text.