Steel piston with filled gallery

Patent metadata

Field	Value
Publication number	US-9951714-B2
Application number	US-201514700654-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	Apr 30, 2014
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A steel piston for an internal combustion including a cooling gallery containing a solid coolant, such as an aluminum-based material, is provided. The solid coolant has a thermal conductivity which is greater than the thermal conductivity of the steel material and fills at least 15 volume percent (vol. %) of the cooling gallery. The solid coolant provides for exceptional cooling along a crown of the piston, reduces corrosion and erosion along the crown, and avoids the problem of oil coking.

First claim

What is claimed is:

1. A piston for an internal combustion engine, comprising:
a body formed of a steel material having a thermal conductivity and extending circumferentially about a center axis;
said body including a crown and a cooling gallery extending along at least a portion of said crown and circumferentially about said center axis;
a coolant filling at least 15 volume percent (vol. %) of said cooling gallery;
said coolant having a thermal conductivity greater than said thermal conductivity of said steel material of said body;
said coolant being a monolithic solid aluminum-based material extending circumferentially continuously about said center axis along said portion of said crown and remaining solid at a temperature of at least 200° C. such that said coolant provides solid structural support to said crown at piston operating temperature of at least 200° C.; and
all surfaces of said coolant being exposed to gas or engaging said steel material of said body.

2. The piston of claim 1 , wherein said crown includes an upper wall, a lower wall, and at least one side wall defining said cooling gallery, said coolant extends continuously along said upper wall, said coolant fills less than 100 vol. % of said cooling gallery and defines a pocket filled with said gas, said gas is air, and said pocket is spaced from said upper wall by said coolant.

3. The piston of claim 1 , wherein said crown includes an upper crown portion and a lower crown portion, said upper crown portion includes a first outer rib and a first inner rib, said lower crown portion includes a second outer rib and a second inner rib, said outer ribs are joined to form an outer side wall, said inner ribs are joined to form an inner side wall, and said side walls define said cooling gallery.

4. The piston of claim 1 , wherein said crown includes a plurality of walls defining said cooling gallery, at least one of said walls includes an inlet hole to said cooling gallery.

5. The piston of claim 4 , wherein said inlet hole is sealed by at least one of said solid coolant, a plug, adhesive, weld, and braze.

6. The piston of claim 1 , wherein said crown includes an upper wall and an inner side wall and an outer side wall together defining said cooling gallery, and said cooling gallery is open.

7. The piston of claim 1 , wherein said body extends circumferentially around a center axis and longitudinally along said center axis from an upper end to a lower end;
said body includes an outer surface and an inner surface;
said crown includes an upper wall and a lower wall and at least one side wall;
said inner surfaces of said upper wall and said lower wall and said at least one side wall of said crown define said cooling gallery;
said outer surface of said crown presents an apex at said center axis, a bowl-shape surrounding said center axis, and a bowl-rim surrounding said bowl-shape;
said at least one side wall includes an outer side wall;
said outer surface of said outer side wall presents a plurality of ring grooves facing away from said center axis and extending circumferentially around said center axis;
said cooling gallery extends circumferentially around said center axis;
said coolant fills at least 50 vol. % of said cooling gallery;
said body includes at least one pin boss depending from said crown and extending circumferentially about said center axis;
said at least one pin boss presents a pin bore extending perpendicular to said center axis;
said body includes at least one skirt section depending from said crown and extending circumferentially about said center axis, and said at least one skirt section is joined to said at least one pin boss.

8. A piston for an internal combustion engine, comprising:
a body formed of a steel material having a thermal conductivity and extending circumferentially about a center axis;
said body including a crown and a cooling gallery extending along at least a portion of said crown and circumferentially about said center axis;
a coolant filling a volume percent (vol. %) of said cooling gallery;
said coolant having a thermal conductivity greater than said thermal conductivity of said steel material of said body;
said coolant being a monolithic aluminum-based material extending circumferentially continuously about said center axis along said portion of said crown such that said coolant provides solid structural support to said crown at piston operating temperature of at least 200° C.; and
wherein said coolant fills at least 90 vol. % of said cooling gallery.

9. The piston of claim 8 , wherein said coolant fills 100 vol. % of said cooling gallery.

10. A piston for an internal combustion engine, comprising:
a body formed of a steel material having a thermal conductivity and extending circumferentially about a center axis;
said body including a crown and a cooling gallery extending along at least a portion of said crown and extending circumferentially about said center axis, said cooling gallery being sealed;
a coolant filling at least 15 volume percent (vol. %) of said sealed cooling gallery;
said coolant having a thermal conductivity greater than said thermal conductivity of said steel material of said body;
said coolant being a monolithic aluminum-based material extending circumferentially continuously about said center axis along said portion of said crown such that said coolant provides solid structural support to said crown at piston operating temperature of at least 200° C.; and
wherein said crown includes a plurality of walls defining said sealed cooling gallery, said coolant extends continuously along each of said walls and completely around said sealed cooling gallery, said coolant fills less than 100 vol. % of said sealed cooling gallery and defines a pocket filled with air, and said pocket is spaced from each of said walls by said coolant.

11. A piston for an internal combustion engine, comprising:
a body formed of a steel material having a thermal conductivity and extending circumferentially about a center axis;
said body including a crown and a cooling gallery extending along at least a portion of said crown and extending circumferentially about said center axis;
a coolant filling at least 15 volume percent (vol. %) of said cooling gallery;
said coolant having a thermal conductivity greater than said thermal conductivity of said steel material of said body;
said coolant being a monolithic aluminum-based material extending circumferentially continuously about said center axis along said portion of said crown such that said coolant provides solid structural support to said crown at piston operating temperature of at least 200° C.; and wherein said crown includes an upper wall and a lower wall and an outer side wall together defining said cooling gallery, and said cooling gallery extends continuously along said upper wall of said crown and through a center axis of said piston.

12. A method of manufacturing a piston for an internal combustion engine, comprising the steps of:
providing a body formed of a steel material having a thermal conductivity and extending circumferentially about a center axis, the body including a crown with a cooling gallery extending along at least a portion of the crown and extending circumferentially about the center axis; and
filling at least 15 volume percent (vol. %) of the cooling gallery with a coolant, the coolant having a thermal conductivity greater than the thermal conductivity of the steel material of the body, the coolant being a monolithic aluminum-based material extending circumferentially continuously about the center axis along the portion of the crown and remaining a solid at a temperature of at least

Assignees

• Federal Mogul Corp
• Fed Mogul Llc

Inventors

• Weinenger Michael

Classifications

• F05C2201/021

  Aluminium · CPC title

• B23P15/10

  pistons · CPC title

• F05C2201/0448

  Steel · CPC title

• Y10T29/49254

  Utilizing a high energy beam, e.g., laser, electron beam · CPC title

• F02F3/18 Primary

  the means being a liquid or solid coolant, e.g. sodium, in a closed chamber in piston · CPC title