Controlled spark ignited flame kernel flow in fuel-fed prechambers

Patent metadata

Field	Value
Publication number	US-10907532-B2
Application number	US-201615332718-A
Country	US
Kind code	B2
Filing date	Oct 24, 2016
Priority date	Nov 23, 2010
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

A pre-chamber spark plug that includes a shell. Additionally, the pre-chamber spark plug includes an insulator disposed within the shell. In a particular embodiment, a center electrode has a first portion surrounded by the insulator, and a second portion that extends from the insulator into a pre-chamber. The pre-chamber defined by the shell. In a further embodiment, a ground electrode is attached to the insulator. In particular embodiments, the ground electrode is tubular in shape and includes an inner spark surface ring spaced in surrounding relation to the center electrode to create a spark gap, an outer ring attached to the shell, and a plurality of rounded spokes connecting the inner and outer rings. In a particular embodiment, the ground and center electrodes accommodate attachment of precious metal alloys to increase electrode surface life. In another embodiment the ground electrode and insulator is coaxial to the center electrode.

First claim

What is claimed is:

1. A pre-chamber igniter comprising:
a pre-chamber housing defining an enclosed pre-chamber;
a first body in the pre-chamber housing, the first body comprising a portion extending forward from a back of the pre-chamber into the pre-chamber; and
a second body in the pre-chamber housing and surrounding the first body, the second body comprising:
a first portion spaced in surrounding relation to the first body to define an ignition region between the second body and the first body, and
a second portion defining a radial offset circumferential extension extending axially forward past an end of the first body to form an aerodynamic nose cone, the radial offset circumferential extension defining an internal cavity and comprising an opening to the internal cavity at a longitudinal end of the second portion, where the radial offset circumferential extension extends continuously from the first portion surrounding the end of the first body to a position past the end of the first body, where the opening is wider than the first body in the ignition region, and the internal cavity is widest at the opening at the longitudinal end of the second portion.

2. The pre-chamber igniter of claim 1 , comprising a first stage defined by a cavity formed between the first body and a velocity control tube of the second body, the velocity control tube surrounding the entire portion of the first body extending into the pre-chamber.

3. The pre-chamber plug of claim 2 , comprising a second stage defined by a cavity between the velocity control tube and the pre-chamber housing.

4. The pre-chamber plug of claim 3 , wherein the velocity control tube comprises a lateral opening exposing the first stage to the second stage and configured to allow a flame kernel to exit the first stage and enter the second stage.

5. The pre-chamber of claim 4 , wherein the lateral opening is angled such that the lateral opening has a longitudinal axis that is neither perpendicular nor parallel to a longitudinal axis of the pre-chamber igniter and does not intersect the longitudinal axis of the pre-chamber igniter.

6. The pre-chamber igniter of claim 1 , comprising an opening in the pre-chamber housing configured to direct a primary flow of an air/fuel mixture into the aerodynamic nose cone at a velocity between one and one-hundred meters per second.

7. The pre-chamber igniter of claim 6 , comprising a second opening in the pre-chamber housing configured to cause a secondary flow of the air/fuel mixture into the pre-chamber to swirl about the pre-chamber.

8. The pre-chamber igniter of claim 7 , wherein the second opening comprises a plurality of second openings angled such that each has a longitudinal axis that is neither perpendicular nor parallel to a longitudinal axis of the pre-chamber igniter and does not intersect the longitudinal axis of the pre-chamber igniter.

9. The pre-chamber igniter of claim 1 , comprising a fuel injector nozzle in the pre-chamber configured to enrich a fuel to air ratio of the pre-chamber.

10. The pre-chamber igniter of claim 1 , wherein a front end of the first body is a flat surface.

11. The pre-chamber igniter of claim 1 , comprising a tube surrounding the entire portion of the first body in the pre-chamber, the tube comprising the radial offset circumferential extension.

12. The pre-chamber igniter of claim 1 , wherein the pre-chamber igniter is a laser igniter configured to direct a laser light beam to the ignition region, the laser light beam configured to heat an air-fuel mixture in the ignition region to an ignition temperature and create a flame kernel.

13. The pre-chamber igniter of claim 1 , wherein the ignition region is positioned within the pre-chamber and is configured to receive a flow of air/fuel mixture from an opening in the pre-chamber housing.

14. A method of facilitating combustion in an internal combustion engine using the pre-chamber igniter of claim 1 , the method comprising:
receiving the primary flow of air/fuel mixture through a first opening into the pre-chamber of the pre-chamber igniter, to permit a primary flow of the air/fuel mixture into the ignition region of the pre-chamber;
igniting the air/fuel mixture, wherein an ignition event produces a flame kernel;
transporting the flame kernel to a first stage of the pre-chamber wherein the first stage of the pre-chamber is defined by a cavity disposed between a tube surrounding the first body and the first body;
receiving a secondary flow of the air/fuel mixture into the pre-chamber through a second opening into the pre-chamber to disperse the secondary flow throughout a second stage of the pre-chamber, wherein the second stage of the pre-chamber is defined by a cavity disposed outside of the second body;
wherein the flame kernel travels from the first stage to the second stage; and
igniting the secondary flow of the air/fuel mixture causing a flame jet to issue from the first and second openings.

15. The method of claim 14 , wherein the flame kernel travels from the first stage to the second stage through lateral openings in the second body.

16. The method of claim 14 , wherein receiving the secondary flow comprises receiving the secondary flow into the pre-chamber through a plurality of second openings having a longitudinal axis that is not parallel with, perpendicular to, and does not intersect a longitudinal axis of the pre-chamber igniter.

17. The method of claim 14 , wherein the primary flow of the air/fuel mixture into the ignition region has a velocity between one and one-hundred meters per second.

18. The method of claim 14 , comprising cooling the ignition region and the second body with the primary flow.

19. The method of claim 14 , comprising:
injecting fuel into the pre-chamber via a fuel injector nozzle in the pre-chamber and enriching a fuel to air ratio of the pre-chamber.

20. A pre-chamber igniter, comprising:
a pre-chamber housing defining an enclosed pre-chamber;
a first body extending into the pre-chamber;
a second body in the pre-chamber, comprising:
an inner ring spaced in surrounding relation to the first body forming an ignition region there between; and
a portion defining a radial offset circumferential extension extending axially forward past an end of the first body, the radial offset circumferential extension defining an internal cavity and comprising an opening to the internal cavity at a longitudinal end of the portion of the second body, where the radial offset circumferential extension extends continuously from the inner ring surrounding the end of the first body to a position past the end of the first body, where the opening is wider than the first body in the ignition region, and the internal cavity is widest at the opening at the longitudinal end of the portion of the second body.

21. The pre-chamber igniter of claim 20 , comprising a gas admission valve integrally formed with the pre-chamber housing, wherein the gas admission valve dispenses fuel from storage chambers into the pre-chamber housing.

22. The pre-chamber igniter of claim 20 , comprising a plurality of openings in the pre-chamber housing configured to connect an end cap of the pre-chamber igniter to a cylinder chamber.

23. The pre-chamber igniter of claim 22 , comprising:
a first stage of the pre-chamber that is defined by a cavity spaced between an inner surface of the second body and an outer surface of the first body; and
a second stage of the pre-chamber that is def

Assignees

• Woodward Inc

Inventors

• Chiera Domenico
• Petruska David C
• Hampson Gregory James

Classifications

• F02B19/12 Primary

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title

• F02B19/16

  Chamber shapes or constructions not specific to sub-groups F02B19/02 - F02B19/10 · CPC title

• F02P15/001

  Ignition installations adapted to specific engine types (ignition of jet propulsion plants F02K9/95; for rotary piston engines F02B53/12) · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02P23/04

  Other physical ignition means, e.g. using laser rays · CPC title