IP Library › Granted Patent US 12,359,609
Granted Patent B1
US 12,359,609 · App. 18/679,767 · Granted Jul 15, 2025

Extended-life prechamber sparkplug for engine system and engine system operating method

Inventors: James Jay Cress (West Lafayette, IN); Andrew G. Hockett (Austin, TX); Sean J. Moser (Bellingham, WA)
Assignee: Caterpillar Inc.
F02B19/02F02B19/12F02B19/18F02M21/023
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Quick Facts
Patent No.
US 12,359,609
App. No.
18/679,767
Granted
Jul 15, 2025
Kind
B1
Abstract

A prechamber sparkplug includes a sparkplug housing forming a prechamber, and an electrode within the prechamber and defining a spark gap with the sparkplug housing. The prechamber sparkplug further includes a valvular element such as a check, a valve, or a tesla valve, structured to preferentially permit ejection of fluids from the prechamber over admission of fluids to the prechamber. Varying relative restriction of fluids into versus out of the prechamber can limit a charge density within the prechamber extending sparkplug service life, particularly in high power density engine applications. Related apparatus and methodology is also disclosed.

Claims (31)

1. A prechamber spark plug comprising:

a spark plug housing including an outer housing surface, and an inner housing surface forming a prechamber;

an electrode within the prechamber, and defining a spark gap with the spark plug housing;

the spark plug housing further forming at least one fluid conduit extending between the inner housing surface and the outer housing surface;

a valvular element at least partially within the at least one fluid conduit and structured to preferentially permit ejection of fluids from the prechamber over admission of fluids to the prechamber via the at least one fluid conduit; and

the spark plug housing forms a plurality of always-open fluid conduits extending between the inner housing surface and the outer housing surface and fluidly connected to the prechamber.

2. The prechamber spark plug of claim 1 wherein the valvular element is movable to vary a flow area through the at least one fluid conduit.

3. The prechamber spark plug of claim 2 wherein the valvular element is pivotable relative to the spark plug housing in a pivoting range.

4. The prechamber spark plug of claim 3 wherein the pivoting range extends outside of the spark plug housing.

5. The prechamber spark plug of claim 1 wherein the valvular element includes a check movable from an open position to a second position in response to an incoming flow of fluids through the at least one conduit.

6. The prechamber spark plug of claim 5 wherein the second position includes a closed position blocking admission of fluids to the prechamber.

7. The prechamber spark plug of claim 6 wherein the at least one fluid conduit includes a plurality of fluid conduits, and the check blocks the plurality of fluid conduits at the closed position.

8. The prechamber spark plug of claim 1 wherein the at least one fluid conduit fluidly connects a plurality of outer ports formed in the outer housing surface to a singular inner port formed in the inner housing surface.

9. The prechamber spark plug of claim 8 wherein the spark plug housing includes a tip piece, and the at least one fluid conduit is one of a plurality of fluid conduits formed in the tip piece, and the valvular element is one of a plurality of valvular elements each positioned at least partially within a respective one of the plurality of fluid conduits.

10. The prechamber spark plug of claim 1 wherein the valvular element includes a tesla valve.

11. A prechamber spark plug comprising:

a spark plug housing including an outer housing surface, and an inner housing surface forming a prechamber;

an electrode within the prechamber, and defining a spark gap with the spark plug housing;

the spark plug housing further forming at least one fluid conduit extending between the inner housing surface and the outer housing surface; and

a valvular element at least partially within the at least one fluid conduit and structured to preferentially permit ejection of fluids from the prechamber over admission of fluids to the prechamber via the at least one fluid conduit;

wherein the valvular element includes a check movable from an open position to a second position in response to an incoming flow of fluids through the at least one conduit;

wherein the second position includes a closed position blocking admission of fluids to the prechamber;

wherein the at least one fluid conduit includes a plurality of fluid conduits, and the check blocks the plurality of fluid conduits at the closed position; and

wherein the spark plug housing forms a plurality of always-open fluid conduits extending between the inner housing surface and the outer housing surface.

12. A prechamber spark plug comprising:

a spark plug housing including an outer housing surface, and an inner housing surface forming a prechamber;

an electrode within the prechamber, and defining a spark gap with the spark plug housing;

the spark plug housing further forming at least one fluid conduit extending between the inner housing surface and the outer housing surface; and

a valvular element at least partially within the at least one fluid conduit and structured to preferentially permit ejection of fluids from the prechamber over admission of fluids to the prechamber via the at least one fluid conduit,

wherein the at least one fluid conduit fluidly connects a plurality of outer ports formed in the outer housing surface to a singular inner port formed in the inner housing surface,

wherein the spark plug housing includes a tip piece, and the at least one fluid conduit is one of a plurality of fluid conduits formed in the tip piece, and the valvular element is one of a plurality of valvular elements each positioned at least partially within a respective one of the plurality of fluid conduits.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 31, 2024
From: CRESS, JAMES JAY; HOCKETT, ANDREW G.; MOSER, SEAN J.
To: CATERPILLAR INC.
Reel/Frame 067579/0772 →
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