Fuel injector having a self-contained replaceable pilot valve assembly

Patent metadata

Field	Value
Publication number	US-11466652-B2
Application number	US-201715622541-A
Country	US
Kind code	B2
Filing date	Jun 14, 2017
Priority date	Jun 14, 2017
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

A fuel injector device for injecting fuel into a combustion chamber of an internal combustion engine is provided. Included in the fuel injector is a body having a chamber and a pilot valve assembly including a seat retainer configured to be detachably insertable into the chamber of the body. A pilot valve seat is disposed in the seat retainer and substantially enclosed by the seat retainer. A stator assembly is disposed in the seat retainer and at least partially enclosed by the seat retainer. The pilot valve seat and the stator assembly in the pilot valve assembly are replaceable as a single unit of the pilot valve assembly for the fuel injector.

First claim

What is claimed is:

1. A fuel injector, comprising:
an injector body having a chamber in contact with fuel inside the chamber, the injector body including an integrated needle sleeve for receiving a needle valve;
a pilot valve assembly including a seat retainer configured to be detachably insertable into the chamber of the injector body and an armature assembly and a guide support disposed in the seat retainer, the seat retainer extending outside of the chamber of the injector body when inserted into the chamber of the injector body;
a pilot valve seat disposed in the seat retainer and substantially enclosed by the seat retainer, the seat retainer substantially enclosing the pilot valve seat by enclosing a lower portion of the pilot valve seat to be fully within the seat retainer; and
a stator assembly disposed in the seat retainer, the stator assembly being in contact with a portion of the seat retainer and at least partially enclosed by the portion of the seat retainer in contact with the stator assembly;
wherein:
a lower end of the guide support includes a radially inclined inner surface in contact with an upper portion of the pilot valve seat having a corresponding radially inclined outer surface, the radially inclined inner surface having a wider opening relative to a longitudinal axis of the guide support, toward an edge of the lower end;
each of the seat retainer, the pilot valve seat, the stator assembly, and the armature assembly includes a central axis aligned to each other; and
the stator assembly, the pilot valve seat, and the armature assembly are replaceable as a single unit for the fuel injector.

2. The fuel injector of claim 1 , wherein no portion of the pilot valve seat is exposed outside of the seat retainer.

3. The fuel injector of claim 1 , wherein the seat retainer and the stator assembly are integrated as a unitary unit.

4. The fuel injector of claim 1 , wherein a lower portion of the seat retainer includes a retainer central passage extending longitudinally from a lower end of the seat retainer toward an upper end of the seat retainer.

5. The fuel injector of claim 4 , wherein the pilot valve seat includes a valve seat central passage extending longitudinally from a lower end of the pilot valve seat toward an upper end of the pilot valve seat.

6. The fuel injector of claim 5 , wherein the valve seat central passage is fluidly coupled to the retainer central passage of the seat retainer.

7. The fuel injector of claim 1 , wherein the chamber of the injector body is configured for receiving, at least partially, a lower end of the seat retainer.

8. The fuel injector of claim 1 , wherein the guide support is disposed between the armature assembly and the pilot valve seat.

9. The fuel injector of claim 8 , wherein the stator assembly includes a solenoid disposed directly above the armature assembly, and the solenoid has an active state in which the armature assembly is in an upward position and an inactive state in which the armature assembly is in a downward position.

10. The fuel injector of claim 8 , wherein the armature assembly is positioned within the chamber and includes a plunger central bore configured for receiving a plunger.

11. The fuel injector of claim 8 , wherein the guide support, has an inner bore configured to receive an armature spring and a lower end of the armature assembly.

12. A pilot valve assembly used in a fuel injector, the pilot valve assembly comprising:
a seat retainer having an inner chamber configured to be detachably insertable into a chamber of an injector body of the fuel injector, a lower portion of the seat retainer including a retainer central passage and the seat retainer extending outside of the chamber of the injector body when inserted into the chamber of the injector body;
a stator assembly disposed in the inner chamber of the seat retainer, the stator assembly being in contact with a portion of the seat retainer and at least partially enclosed by the portion of the seat retainer in contact with the stator assembly;
a pilot valve seat disposed in the inner chamber of the seat retainer and substantially enclosed by the seat retainer, the seat retainer substantially enclosing the pilot valve seat by enclosing a lower portion of the pilot valve seat to be fully within the seat retainer such that the pilot valve seat does not extend into the retainer central passage;
an armature assembly disposed between the stator assembly and the pilot valve seat configured to facilitate reciprocal movement within the inner chamber of the seat retainer,
a guide support disposed in the inner chamber of the seat retainer between the armature assembly and the pilot valve seat, a lower end of the guide support including a radially inclined inner surface having a wider opening relative to a longitudinal axis of the guide support toward an edge of the lower end, the radially inclined inner surface being in contact with an upper portion of the pilot valve seat having a corresponding radially inclined outer surface;
wherein:
each of the seat retainer, the pilot valve seat, the stator assembly, and the armature assembly includes a central axis aligned to each other; and
the stator assembly, the pilot valve seat, and the armature assembly disposed, at least partially, in the inner chamber of the seat retainer are replaceable as a single unit for the fuel injector.

13. The pilot valve assembly of claim 12 , wherein the retainer central passage extends longitudinally from a lower end of the seat retainer toward an upper end of the seat retainer.

14. The pilot valve assembly of claim 13 , wherein the pilot valve seat includes a valve seat central passage extending longitudinally from a lower end of the pilot valve seat toward an upper end of the pilot valve seat such that the valve seat central passage is fluidly coupled to the retainer central passage of the seat retainer.

15. A fuel injector, comprising:
an injector body having a chamber in contact with fuel inside the chamber, the injector body including an integrated needle sleeve for receiving a needle valve;
a pilot valve assembly including a seat retainer configured to be detachably insertable into the chamber of the injector body and an armature assembly and a guide support disposed in the seat retainer, the seat retainer extending outside of the chamber of the injector body when inserted into the chamber of the injector body;
a pilot valve seat disposed in the seat retainer and substantially enclosed by the seat retainer, the seat retainer substantially enclosing the pilot valve seat by enclosing a lower portion of the pilot valve seat to be fully within the seat retainer;
a plunger positioned above the pilot valve seat and extending through the armature assembly; and
a stator assembly disposed in the seat retainer, the stator assembly being in contact with a portion of the seat retainer and at least partially enclosed by the portion of the seat retainer in contact with the stator assembly;
wherein:
a lower end of the guide support includes a radially inclined inner surface in contact with an upper portion of the pilot valve seat having a corresponding radially inclined outer surface, the radially inclined inner surface having a wider opening relative to a longitudinal axis of the guide support toward an edge of the lower end;
each of the seat retainer, the pilot valve seat, the stator assembly, and the armature assembly includes a central axis aligned to each other; and
the stator assembly, the pilot valve seat, and the armature assembly are replaceable as a single unit for the fuel injector.

Assignees

• Cummins Inc

Inventors

• Primus Raymond V
• Gray Jr Ryan S

Classifications

• F02M2200/8076

  involving threaded members · CPC title

• F02M63/0029 Primary

  using a pilot valve controlling a hydraulic chamber · CPC title

• F02M2200/28

  Details of throttles in fuel-injection apparatus · CPC title

• F02M61/168

  Assembling; Disassembling; Manufacturing; Adjusting · CPC title

• F02M2200/708

  with hydraulic chambers formed by a movable sleeve · CPC title