Passive igniter cooling in cylinder head assembly

Patent metadata

Field	Value
Publication number	US-11536220-B1
Application number	US-202217691516-A
Country	US
Kind code	B1
Filing date	Mar 10, 2022
Priority date	Mar 10, 2022
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A cylinder head in a cylinder head assembly includes an upper deck, a fire deck, gas exchange conduits, and a coolant cavity extending peripherally around the gas exchange conduits. The cylinder head also includes an igniter socket having an igniter post, and a radially outward sleeve step continuously circumferential of an igniter bore center axis. A cooling moat is formed between the igniter post and the sleeve step. The coolant cavity includes a valve bridge through-channel and a valve bridge part-way channel each fluidly connected to the igniter socket to provide coolant flow into and out of the cooling moat passively.

First claim

What is claimed is:

1. A cylinder head comprising:
a cylinder head casting including an upper deck, a fire deck, four gas exchange conduits extending to four gas exchange openings in the fire deck, a coolant cavity formed between the upper deck and the fire deck and extending peripherally around the four gas exchange conduits, and an igniter bore defining a bore center axis and extending downwardly through the upper deck to the coolant cavity;
the cylinder head casting further including an igniter socket having a radially inward igniter post, a radially outward sleeve step that is circumferential of the bore center axis, and a cooling moat formed between the igniter post and the sleeve step; and
the coolant cavity including a valve bridge through-channel extending to the igniter socket and formed between two of the four gas exchange conduits, and a valve bridge part-way channel extending from the igniter socket and formed between two of the four gas exchange conduits.

2. The cylinder head of claim 1 wherein the coolant cavity includes a second valve bridge through-channel arranged opposite to the first valve bridge through-channel, circumferentially around the bore center axis.

3. The cylinder head of claim 2 wherein the coolant cavity includes a second valve bridge part-way channel arranged opposite to the first valve bridge part-way channel, circumferentially around the bore center axis.

4. The cylinder head of claim 3 wherein:
the coolant cavity forms a peripherally outward cavity space that is circumferential of the four gas exchange conduits;
each respective valve bridge through-channel fluidly connects the peripherally outward cavity space to the igniter socket; and
the cylinder head casting includes cast material blocking each respective valve bridge part-way channel from the peripherally outward cavity space.

5. The cylinder head of claim 3 wherein each respective valve bridge part-way channel is contoured to direct an outgoing flow of coolant from the igniter socket upward in the cylinder head casting.

6. The cylinder head of claim 1 wherein the igniter post is cylindrical.

7. The cylinder head of claim 6 wherein the sleeve step includes an upward facing step surface, and a peripheral wall surface radially outward of the upward facing step surface.

8. The cylinder head of claim 6 wherein the peripheral wall surface is cylindrical, and the upward facing step surface extends from the peripheral wall surface to a cylindrical outer moat surface.

9. The cylinder head of claim 7 wherein each of the valve bridge through-channel and the valve bridge part-way channel is formed by an as-cast surface, and the peripheral wall surface includes a machined surface forming a first common edge with the as-cast surface at the valve bridge through-channel, and a second common edge with the as-cast surface at the valve bridge part-way channel.

10. A cylinder head assembly comprising:
a cylinder head having formed therein an igniter bore extending downwardly from an upper deck to a coolant cavity and defining a bore center axis, and an igniter socket including an igniter post extending upwardly from a fire deck in a direction of the coolant cavity;
an igniter sleeve including a first axial sleeve end within the igniter bore, a second axial sleeve end interference-fitted with the igniter post, and a plurality of stop surfaces located between the first axial sleeve end and the second axial sleeve end;
the igniter socket further including a sleeve step extending continuously circumferentially around the bore center axis and contacted by the plurality of stop surfaces, and a cooling moat formed between the sleeve step and the igniter post and receiving the second axial sleeve end; and
a plurality of coolant openings are defined between the igniter sleeve and the sleeve step at locations angularly between the plurality of stop surfaces, circumferentially around the bore center axis, and coolant flow between the coolant cavity and the cooling moat is confined to the plurality of coolant openings.

11. The cylinder head assembly of claim 10 wherein the plurality of stop surfaces and the plurality of coolant openings each number 3 or 4.

12. The cylinder head assembly of claim 10 wherein:
the cylinder head further includes four gas exchange conduits and four valve bridges in an alternating arrangement with the four gas exchange conduits circumferentially around the bore center axis; and
the coolant cavity further includes a first valve bridge through-channel and a second valve bridge through-channel formed in two of the four valve bridges, and a first valve bridge part-way channel and a second valve bridge part-way channel formed in a different two of the four valve bridges.

13. The cylinder head assembly of claim 12 wherein the first and the second valve bridge through-channels are in an alternating arrangement with the first and the second valve bridge part-way channels, circumferentially around the bore center axis.

14. The cylinder head assembly of claim 10 wherein the sleeve step includes an upward facing step surface oriented normal to the bore center axis, and a peripheral wall surface radially outward of the upward facing step surface.

15. The cylinder head assembly of claim 14 wherein the peripheral wall surface is cylindrical.

16. The cylinder head assembly of claim 10 further comprising a sparkplug igniter within the igniter sleeve.

17. A method of cooling an igniter in a cylinder head assembly comprising:
conveying coolant through a first valve bridge channel of a coolant cavity to an igniter socket in a cylinder head;
conveying the coolant through a cooling moat of the igniter socket receiving an igniter sleeve for the igniter;
exchanging heat between the coolant and the igniter sleeve within the cooling moat;
conveying the coolant from the igniter socket to a second valve bridge channel of the coolant cavity; and
limiting a flow of the coolant between the cooling moat and the coolant cavity to a finite number of coolant openings defined between the igniter sleeve and the igniter socket.

18. The method of claim 17 wherein the conveying coolant through a cooling moat includes conveying the coolant through a cooling moat extending circumferentially around an igniter post interference-fitted with the igniter sleeve in the cylinder head.

19. The method of claim 18 wherein the limiting a flow of the coolant includes limiting the flow to a finite number of coolant openings defined between the igniter sleeve and a sleeve step of the igniter socket extending continuously circumferentially around the cooling moat and the igniter post.

20. The method of claim 17 wherein the conveying coolant through a first valve bridge channel to an igniter socket includes conveying the coolant through a valve bridge through-channel, and the conveying the coolant from the igniter socket to a second valve bridge channel includes conveying the coolant to a valve bridge part-way channel.

Assignees

• Caterpillar Inc

Inventors

• Chittenden Jonathan Richard
• Howard Jeff Allen
• Petrariu Viorel
• Milem John W

Classifications

• F01P3/16

  for cooling fuel injectors or sparking-plugs · CPC title

• F01P3/14

  for cooling intake or exhaust valves · CPC title

• F02F1/40 Primary

  cylinder heads with means for directing, guiding, or distributing liquid stream · CPC title

• F02F1/242 Primary

  Arrangement of spark plugs or injectors · CPC title

• F01P3/02

  Arrangements for cooling cylinders or cylinder heads · CPC title