Fuel injector assembly having sleeve for directing fuel flow

Patent metadata

Field	Value
Publication number	US-9976527-B1
Application number	US-201715405925-A
Country	US
Kind code	B1
Filing date	Jan 13, 2017
Priority date	Jan 13, 2017
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A fuel injector assembly for an engine system includes a fuel pressurization mechanism, a fuel injector, and a flow-directing sleeve positioned about the fuel injector and including sealing surfaces for sealing with a cylinder head and with an injector body. Slots are formed at least in part in the sealing surfaces to direct fuel from the cylinder head into an incoming cooling passage extending to the fuel pressurization mechanism, and from an outgoing cooling fuel passage into the cylinder head.

First claim

What is claimed is:

1. A fuel injector assembly comprising:
a fuel pressurization mechanism;
a fuel injector coupled with the fuel pressurization mechanism, and including an injector body defining a nozzle outlet for injecting pressurized fuel into an engine cylinder, a fuel inlet, a fuel outlet, an incoming cooling passage extending between the fuel inlet and the fuel pressurization mechanism, and an outgoing cooling passage extending between the fuel pressurization mechanism and the fuel outlet;
a flow-directing sleeve positioned about the injector body, the flow-directing sleeve defining a longitudinal axis and including a first sealing surface extending circumferentially around the longitudinal axis and structured to sealingly contact a cylinder head in the internal combustion engine, and a second sealing surface extending circumferentially around the longitudinal axis and structured to sealingly contact the injector body; and
a first slot being formed at least in part in the first sealing surface, for fluidly connecting the fuel inlet to a first segment of a fuel conduit within the cylinder head, and a second slot being formed at least in part in the second sealing surface, for fluidly connecting the fuel outlet to a second segment of the fuel conduit.

2. The assembly of claim 1 wherein at least a portion of the flow-directing sleeve is located axially between the fuel inlet and the fuel outlet, and wherein the first sealing surface includes an outer sealing surface having a conical shape, and the second sealing surface includes an inner sealing surface having a conical shape.

3. The assembly of claim 2 wherein the first sealing surface is positioned at a first axial location closer to the nozzle outlet, and the second sealing surface is positioned at a second axial location further from the nozzle outlet, and wherein the incoming cooling passage and the outgoing cooling passage each have an axial extent and a radial extent within the injector body.

4. The assembly of claim 3 wherein the injector body includes an outer body surface including a first retention surface facing a first axial direction, and the flow-directing sleeve includes a second retention surface facing a second axial direction that is opposite the first axial direction and abutting the first retention surface to limit axial displacement of the flow-directing sleeve relative to the injector body.

5. The assembly of claim 4 wherein the outer body surface includes an outer injector body surface having a conical shape, and the second sealing surface sealingly contacts the outer body surface.

6. The assembly of claim 3 wherein the first slot is positioned at a first circumferential location about the longitudinal axis, and the second slot is positioned at a second circumferential location about the longitudinal axis that is less than 180 degrees from the first circumferential location.

7. The assembly of claim 5 wherein the flow-directing sleeve includes an interior channel located axially between the first sealing surface and the second sealing surface, the interior channel extending circumferentially around the longitudinal axis and fluidly connecting the fuel outlet to the second slot.

8. The assembly of claim 1 wherein the fuel pressurization mechanism is attached to the injector body and includes a plunger, and a tappet coupled with the plunger.

9. The assembly of claim 8 wherein the fuel outlet is located at a first axial position in the injector body, and the injector body defines a second fuel outlet located at a second axial position in the injector body that is further from the nozzle outlet than the first axial position.

10. An engine system comprising:
a cylinder head defining a fuel conduit having a first segment and a second segment, and an injector bore positioned fluidly between the first segment and the second segment of the fuel conduit;
a fuel injector positioned at least partially within the injector bore, and including a fuel pressurization mechanism;
the fuel injector including an injector body defining a fuel inlet, a fuel outlet, an incoming cooling passage extending between the fuel inlet and the fuel pressurization mechanism, and an outgoing cooling passage extending between the fuel pressurization mechanism and the fuel outlet;
a flow-directing sleeve positioned about the injector body and defining a longitudinal axis, the flow-directing sleeve including a first sealing surface extending circumferentially around the longitudinal axis and in sealing contact with the cylinder head, and a second sealing surface extending circumferentially around the longitudinal axis and in sealing contact with the injector body; and
a first slot being formed at least in part in the first sealing surface and fluidly connecting the fuel inlet to the first segment of the fuel conduit, and a second slot being formed at least in part in the second sealing surface and fluidly connecting the fuel outlet to the second segment of the fuel conduit.

11. The system of claim 10 wherein the first segment of the fuel conduit and the second segment of the fuel conduit define a common plane oriented normal to the longitudinal axis.

12. The system of claim 10 wherein the fuel injector is one of a first set of fuel injectors each including a fuel pressurization mechanism having a plunger and a tappet coupled with the plunger, and further comprising a second set of fuel injectors each of which does not include a fuel pressurization mechanism.

13. The system of claim 12 wherein the flow-directing sleeve is one of a plurality of flow-directing sleeves in the engine system, and a total number of the plurality of flow-directing sleeves is equal to less than a total number of the fuel injectors of the first set.

14. The system of claim 12 further comprising a common fuel rail, and wherein each of the fuel injectors of the first set and each of the fuel injectors of the second set is in fluid communication with the common fuel rail.

15. A sleeve for directing a flow of cooling fuel into and out of a fuel injector in a cylinder head of an internal combustion engine, the sleeve comprising:
a one-piece annular body positionable about a fuel injector, the one-piece annular body defining a longitudinal axis and including a first axial end, a second axial end, and an inner peripheral surface and an outer peripheral surface each extending between the first axial end and the second axial end;
the outer peripheral surface including a first sealing surface structured to sealingly contact a cylinder head within an injector bore receiving the fuel injector within the cylinder head, the first sealing surface extending circumferentially around the longitudinal axis at a first location axially between the first axial end and the second axial end;
the inner peripheral surface including a second sealing surface structured to sealingly contact the fuel injector, and extending circumferentially around the longitudinal axis at a second location axially between the first axial end and the second axial end;
a first slot being formed at least in part in the first sealing surface, for fluidly connecting a fuel inlet in the fuel injector to a first segment of a fuel conduit within the cylinder head; and
a second slot being formed at least in part in the second sealing surface, for fluidly connecting a fuel outlet in the fuel injector to a second segment of the fuel conduit.

16. The sleeve of claim 15 wherein the first slot is positioned at a first circumferential location about the longitudinal axis, and the second slot is positioned at a second circumferenti

Assignees

• Caterpillar Inc

Inventors

• Campion Robert
• Joseph George Kodikulam
• Pillarisetti Satya Naga Deepak
• Li Zhenyu

Classifications

• F02M55/004

  Joints; Sealings · CPC title

• F02M55/008

  Arrangement of fuel passages inside of injectors · CPC title

• F02M55/025

  Common rails · CPC title

• F02M53/043 Primary

  with cooling means other than air cooling · CPC title

• F02M61/14

  Arrangements of injectors with respect to engines; Mounting of injectors · CPC title