Fuel injector and nozzle assembly having spray duct with center body for increased flame liftoff length

Patent metadata

Field	Value
Publication number	US-11879418-B2
Application number	US-202217582346-A
Country	US
Kind code	B2
Filing date	Jan 24, 2022
Priority date	Jan 24, 2022
Publication date	Jan 23, 2024
Grant date	Jan 23, 2024

Abstract

A fuel injector includes a nozzle body, and spray ducts coupled to the nozzle body and in spray path alignment with spray orifices therein. A nozzle check is movable within the nozzle body to open and close the spray orifices. Each of the spray ducts defines a duct center axis, and includes a center body forming, together with a duct inner surface, a spray jet passage circumferential of the duct center axis and reduced in area in a direction of spray jet advancement from the nozzle body.

First claim

What is claimed is:

1. A fuel injector comprising:
a nozzle body having a plurality of spray orifices formed therein;
a plurality of spray ducts coupled to the nozzle body and in spray path alignment with the plurality of spray orifices;
a nozzle check movable within the nozzle body between an open position, and a closed position blocking the plurality of spray orifices; and
each of the plurality of spray ducts defining a duct center axis, and including a duct inner surface, and a center body forming, together with the duct inner surface, a spray jet passage extending circumferentially around the duct center axis and reduced in area in a direction of spray jet advancement from the nozzle body.

2. The fuel injector of claim 1 wherein the center body includes a center body outer surface tapered in the direction of spray jet advancement.

3. The fuel injector of claim 2 wherein the center body outer surface is conoidal and extends between a leading cone peak located on the duct center axis and a trailing cone base.

4. The fuel injector of claim 3 wherein an outlet of the spray jet passage is defined between the duct inner surface and the center body and extends circumferentially around the trailing cone base.

5. The fuel injector of claim 1 further comprising at least one support connecting between the duct inner surface and the center body.

6. The fuel injector of claim 5 wherein the at least one support is one of a plurality of supports spaced circumferentially around the duct center axis and located within the spray jet passage.

7. The fuel injector of claim 6 wherein the plurality of supports are arranged in an inlet set and an outlet set spaced from the inlet set in the direction of spray jet advancement.

8. The fuel injector of claim 6 wherein the at least one support includes a vane oriented to impart swirl to fuel spray through the spray jet passage.

9. The fuel injector of claim 1 wherein the nozzle body defines a nozzle center axis, and the plurality of spray ducts are spaced circumferentially around the nozzle center axis and angularly oriented relative to the nozzle center axis.

10. A fuel injector nozzle assembly comprising:
a nozzle body defining a nozzle center axis and including an inner nozzle surface, an outer nozzle surface, and a spray orifice extending from the inner nozzle surface to the outer nozzle surface and oriented angularly to the nozzle center axis;
a spray duct coupled to the nozzle body in spray path alignment with the spray orifice;
the spray duct including a duct wall extending between a duct inlet and a duct outlet, and a center body coupled to the duct wall and positioned in a spray jet path extending between the duct inlet and the outlet; and
a spray jet passage is defined peripherally between the duct wall and the center body.

11. The nozzle assembly of claim 10 wherein the spray jet passage is fully circumferential of the center body between the duct inlet and the duct outlet.

12. The nozzle assembly of claim 11 wherein the spray duct further includes at least one support within the spray jet path and connecting the center body to the duct wall.

13. The nozzle assembly of claim 11 wherein the center body is conoidal.

14. The nozzle assembly of claim 13 wherein the duct wall includes a cylindrical duct inner surface.

15. The nozzle assembly of claim 13 wherein the center body includes a cone peak facing a direction of the spray orifice.

16. The nozzle assembly of claim 13 wherein the center body defines a cone angle less than 45°.

Assignees

• Caterpillar Inc

Inventors

• Fitzgerald Russell P
• Martin Glen Clifford

Classifications

• F02M29/06 Primary

  generating whirling motion of mixture · CPC title

• F02M35/10085

  having a connecting piece, e.g. a flange, between the engine and the air intake being foreseen with a throttle valve, fuel injector, mixture ducts or the like · CPC title

• F02M35/10216

  Fuel injectors; Fuel pipes or rails; Fuel pumps or pressure regulators · CPC title

• F02M67/02

  the gas being compressed air, e.g. compressed in pumps (arrangements or adaptations of such pumps F02B) · CPC title

• F02M69/047

  injectors with air chambers, e.g. communicating with atmosphere for aerating the nozzles (F02M69/325 takes precedence) · CPC title