Passive igniter cooling in cylinder head assembly
AssigneeCaterpillar Inc.
InventorsJonathan Richard Chittenden, Jeff Allen Howard, Viorel Petrariu, John W Milem
Life of this patent
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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.
Claims20
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.
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.
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.
Dependencies are inferred from the claim text.