Piston with a cooling gallery

• US 20090151555A1
• Filed: 12/12/2007
• Published: 06/18/2009
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Inventors: Stan, Sorin, Walker, Steve, Gildemeister, Juan, Lapp, Michael T.
• Granted Patent: US 7,918,155 B2
• Time in Patent Office: Days
• US Class Current: 92/172
• CPC Class Codes: F02F 3/003 the parts being connected by casting, brazing, welding or clamping
• CPC Class Codes: F02F 3/0076 the inside of the pistons being provided with ribs or fins
• CPC Class Codes: F02F 3/025 having circumferentially slotted piston skirts, e.g. T-slots
• CPC Class Codes: F02F 3/22 the fluid being liquid
• CPC Class Codes: Y10T 29/49252 Multi-element piston making

Abstract

A piston for an internal combustion engine is provided. The piston crown includes an interior surface that defines at least in part a cooling gallery and a cooling gallery surface within the piston. An annular surface may defines at least in part an annular passageway that allows fluid communication between an outer surface of the piston and the cooling gallery. Opposing annular surfaces may be abutted with a predetermined force, thereby limiting fluid flow from the cooling gallery to an outer surface of the piston. Further, an annular surface may extend into the cooling gallery to form a deflector along the cooling gallery surface, thereby limiting fluid flow from the cooling gallery to an outer surface of the piston.

Claims

1. A piston for an internal combustion engine, comprising:

a piston crown including a crown annular surface and a crown interior surface; and

a piston skirt including a skirt annular surface and a skirt interior surface, the crown interior surface cooperating with the skirt interior surface to define a cooling gallery and a cooling gallery surface within the piston;

wherein the crown annular surface and the skirt annular surface cooperate to form an annular passageway, the annular passageway allowing for fluid communication between an outer surface of the piston and the cooling gallery;

wherein at least one of the crown annular surface and the skirt annular surface extend away from the outer surface of the piston and into the cooling gallery to form a deflector along the cooling gallery surface adjacent the annular passageway for limiting fluid flow from the cooling gallery to the outer surface of the piston.

2. The piston as recited in claim 1, wherein the deflector includes one of a generally triangular, a rectangular, and a generally semi-circular profile.

3. The piston as recited in claim 1, wherein the annular passageway extends from a ring belt portion of the outer piston surface.

4. The piston as recited in claim 1, wherein the crown annular surface and the skirt annular surface each extend away from the outer surface of the piston and into the cooling gallery to form the deflector.

5. The piston as recited in claim 1, wherein the annular passageway extends about a circumference of the piston.

6. The piston as recited in claim 1, wherein the piston crown includes an upper mating surface and the piston skirt includes a lower mating surface, the upper and the lower mating surfaces being fixedly joined to define a wall of the cooling gallery.

7. The piston as recited in claim 1, wherein the piston crown and the piston skirt are fixedly joined together by one of a friction weld, a beam weld, a laser weld, and a mechanical fastener.

8. The piston as recited in claim 1, further including a generally J-shaped groove defining a ledge along the outer surface of the piston and located between an outer edge of the skirt annular surface and the outer piston surface, the J-shaped groove configured to retain fluid between the outer surface of the piston and a cylinder wall.

9. The piston as recited in claim 1, wherein the crown interior surface includes a crown interior projection and the skirt interior surface includes a skirt interior projection inverted relative to the crown interior projection;

wherein the crown interior projection cooperates with the skirt interior surface and the skirt interior projection cooperates with the crown interior surface to form a baffle configured to limit fluid flow from the cooling gallery to the outer surface of the piston.

10. The piston as recited in claim 1, wherein the annular passageway includes an angled portion configured to limit fluid flow toward the outer piston surface.

11. A piston for an internal combustion engine, comprising:

a first interior surface, the first interior surface defining at least a portion of a cooling gallery of the piston;

a first annular surface defining at least a portion of an annular passageway of the piston that allows for fluid communication between an outer surface of the piston and the cooling gallery; and

a first deflector located along the first interior surface adjacent the annular passageway;

the deflector configured to extend into the cooling gallery to generally limit fluid flow from the cooling gallery to the outer surface of the piston.

12. The piston as recited in claim 11, further comprising a second annular surface cooperating with the first annular surface to define the annular passageway.

13. The piston as recited in claim 12, wherein the second annular surface extends inwardly toward the axis of the piston to form a second deflector along the cooling gallery surface at the annular passageway for further limiting fluid flow from the cooling gallery to the outer surface of the piston.

14. The piston as recited in claim 11, further including a generally J-shaped groove defining a ledge along the outer surface of the piston and located between an outer edge of the first annular surface and the outer piston surface, the J-shaped groove configured to retain fluid between the outer surface of the piston and a cylinder wall.

15. The piston as recited in claim 11, further comprising

a first interior projection;

and

a second interior projection inverted relative to the first interior projection;

wherein the first interior projection corresponds with the second interior projection to form a baffle configured to generally limit fluid flow from the cooling gallery to the outer surface of the piston.

16. The piston as recited in claim 11, wherein the annular passageway includes an angled portion configured to limit fluid flow toward the outer piston surface.

17. A method of assembling a piston, comprising:

providing a piston crown having a crown annular surface and a crown interior surface;

providing a piston skirt including a skirt annular surface and a skirt interior surface;

securing the piston crown to the piston skirt, wherein the crown interior surface cooperates with the skirt interior surface to define a cooling gallery and a cooling gallery surface within the piston; and

abutting the crown annular surface and the skirt annular surface with a predetermined force, wherein the predetermined force generally maintains the crown annular surface and skirt annular surface in abutment, thereby generally limiting fluid flow from the cooling gallery to an outer surface of the piston.

18. The method as recited in claim 17, wherein:

securing the piston crown to the piston skirt includes welding the piston crown to the piston skirt; and

abutting the crown annular surface and the skirt annular surface with the predetermined force includes compressing the piston crown and the piston skirt against each other before a weld between the piston crown and piston skirt is hardened.

19. The method as recited in claim 17,

wherein securing the piston crown to the piston skirt includes threadingly engaging the piston crown to the piston skirt;

and

wherein abutting the crown annular surface and the skirt annular surface with the predetermined force includes turning one of the piston crown and piston skirt to bring the crown and skirt annular surfaces into abutting engagement with the predetermined force.

20. The method as recited in claim 17, wherein at least one of the crown annular surface and the skirt annular surface extend away from the outer surface of the piston and into the cooling gallery to form a deflector along the cooling gallery surface.

21. A piston for an internal combustion engine, comprising:

a piston crown including a crown annular surface and a crown interior surface; and

a piston skirt including a skirt annular surface and a skirt interior surface, the crown interior surface cooperating with the skirt interior surface to define a cooling gallery and a cooling gallery surface within the piston;

wherein the crown annular surface and the skirt annular surface are abutted against each other with a predetermined force, thereby generally maintaining the crown annular surface and skirt annular surface in abutment and generally limiting fluid flow from the cooling gallery to an outer surface of the piston.

22. The piston as recited in claim 21, wherein at least one of the crown annular surface and the skirt annular surface extend away from the outer surface of the piston and into the cooling gallery to form a deflector along the cooling gallery surface adjacent the annular passageway for limiting fluid flow from the cooling gallery to the outer surface of the piston.

23. The piston as recited in claim 21, wherein the piston crown and piston skirt are mechanically fastened to each other at a first interface to provide the predetermined force between the crown annular surface and skirt annular surface at a second interface, said first and second interfaces being spaced away from each other.