Piston with cooling gallery and cooling gallery fins

Patent metadata

Field	Value
Publication number	US-9404439-B2
Application number	US-201314051756-A
Country	US
Kind code	B2
Filing date	Oct 11, 2013
Priority date	Oct 12, 2012
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A piston may include a piston crown including radially inner and outer crown mating surfaces, the crown defining at least in part a cooling gallery extending about a periphery of the crown. The piston may include a piston skirt including a pair of oppositely disposed pin bosses, the pin bosses each defining a piston pin bore. The piston skirt may have a radially inner skirt mating surface cooperating along a radially inner interface region with the radially inner crown mating surface, and a radially outer skirt mating surface cooperating along a radially outer interface region with the radially outer crown mating surface such that the cooling gallery is substantially enclosed. The piston may include at least one cooling fin extending from an interior surface of the cooling gallery.

First claim

What is claimed is:

1. A piston, comprising:
a piston crown having a longitudinal axis and including a radially inner crown mating surface and a radially outer crown mating surface, the piston crown defining at least in part a cooling gallery extending about a periphery of the piston crown; and
a piston skirt, including:
a pair of oppositely disposed pin bosses, the pin bosses each defining a piston pin bore;
a radially inner skirt mating surface cooperating along a radially inner interface region with the radially inner crown mating surface;
a radially outer skirt mating surface cooperating along a radially outer interface region with the radially outer crown mating surface such that the cooling gallery is substantially enclosed; and

at least one cooling fin extending from an interior surface of the cooling gallery, the at least one cooling fin having an axial extent and a radial extent transverse to the axial extent, wherein the axial extent is greater than the radial extent, and wherein the radial extent is greatest at a base of the at least one cooling fin and decreases in a direction away from the interior surface from which the at least one cooling fin extends.

2. The piston of claim 1 , wherein the at least one cooling fin is formed in one of an upper interior surface of the cooling gallery and an interior lower surface of the cooling gallery.

3. The piston of claim 1 , wherein at least two cooling fins extend from the interior surface of the cooling gallery, and wherein one of the at least two cooling fins extends from an axially lower interior surface of the cooling gallery and another of the at least two cooling fins extends from an axially upper interior surface of the cooling gallery.

4. The piston of claim 3 , wherein at least a free end of the at least two cooling fins overlap in an axial direction along the longitudinal axis.

5. The piston of claim 1 , wherein the piston crown and the piston skirt form at least one of a friction welded joint, a laser welded joint and a brazed joint along at least one of the radially inner interface region and the radially outer interface region.

6. The piston of claim 1 , wherein the radially inner skirt mating surface and the radially inner crown mating surface couple at the radially inner interface region to define a radially inner joint, and wherein the radially inner joint is disposed in a combustion bowl when the at least one cooling fin is arranged extending from an upper interior surface of the cooling gallery.

7. The piston of claim 1 , wherein the radially inner skirt mating surface and the radially inner crown mating surface couple at the radially inner interface region to define a radially inner joint, and wherein the radially inner joint is disposed below the combustion bowl when the at least one cooling fin is arranged extending from a lower interior surface of the cooling gallery.

8. The piston of claim 1 , wherein the interior surface of the cooling gallery is depressed axially to define a radius at the base of the at least one cooling fin adjacent to a radially inner surface and a radially outer surface of the at least one cooling fin.

9. A piston, comprising:
a piston crown having a longitudinal axis and including a first crown mating surface and a second crown mating surface, the piston crown defining at least partially a cooling gallery extending about a periphery of the piston crown;
a piston skirt, including:
a pair of oppositely disposed pin bosses, the pin bosses each defining a piston pin bore;
a first skirt mating surface cooperating with the first crown mating surface along a first interface region;
a second skirt mating surface cooperating with the second crown mating surface along a second interface region, at least one of the first interface region and the second interface region securely fixed to define a joint;

wherein the piston crown and the piston skirt together define an interior surface of the cooling gallery such that the cooling gallery is substantially enclosed; and
at least one cooling fin extending from at least one of an upper boundary and an axially lower boundary of the interior surface of the cooling gallery, the at least one cooling fin having a radial extent that decreases gradually in a direction away from the interior surface from which the at least one cooling fin extends.

10. The piston of claim 9 , wherein at least two cooling fins are disposed in the cooling gallery, and wherein one of the at least two cooling fins extends from the upper boundary of the interior surface and another of the at least two cooling fins extends from the lower boundary of the interior surface such that a free end of the at least two cooling fins overlap in an axial direction along the longitudinal axis.

11. The piston of claim 9 , wherein the first interface region defines the joint, and the joint is a first radially inner joint disposed in a combustion bowl; and
wherein the second interface region defines a second radially inner joint, the second radially inner joint disposed below the combustion bowl.

12. A method, comprising:
providing a piston crown having a longitudinal axis and including a first crown mating surface and a second crown mating surface, the piston crown defining at least in part a cooling gallery extending about a periphery of the piston crown;
providing a piston skirt including a first skirt mating surface and a second skirt mating surface;
forming at least one cooling gallery fin from at least one of the piston crown and the piston skirt;
adjoining the piston crown to the piston skirt, wherein adjoining the piston crown to the piston skirt includes coupling the first crown mating surface and the second crown mating surface with the first skirt mating surface and the second skirt mating surface to form a first interface region between the first crown mating surface and the first skirt mating surface, a second interface region between the second crown mating surface and the second skirt mating surface, and the cooling gallery defined by the piston crown together with the piston skirt, wherein the piston skirt includes a pair of oppositely disposed pin bosses defining a piston pin bore; and
wherein the at least one cooling gallery fin extends from an interior surface of the cooling gallery and has an axial extent greater than a radial extent, and wherein the radial extent is greatest at a base of the at least one cooling gallery fin and decreases in a direction away from the interior surface from which the at least one cooling gallery fin extends.

13. The method of claim 12 , wherein adjoining the piston crown to the piston skirt further includes fixing the piston crown and the piston skirt together along at least one of the first interface region and the second interface region via at least one of friction welding, laser welding and brazing.

14. The method of claim 12 , wherein forming the at least one cooling gallery fin includes machining a plurality of fins from a block portion formed within the cooling gallery.

15. The method of claim 12 , wherein the at least one cooling gallery fin extends from an axially upper interior surface of the cooling gallery.

16. The method of claim 15 , wherein the first interface region defines a joint, and the joint is a radially inner joint disposed in a combustion bowl area of the piston.

17. The method of claim 12 , wherein the at least one cooling gallery fin extends from an axially lower interior surface of the cooling gallery.

18. The method of claim 17 , wherein the first interface region forms a radially

Assignees

• Mahle Int Gmbh

Inventors

• Klein Ralph

Classifications

• F02F3/22 Primary

  the fluid being liquid · CPC title

• Y10T29/49256

  with assembly or composite article making · CPC title

• F02F2003/0061

  by welding · CPC title

• F02F3/16 Primary

  having cooling means · CPC title

• F02F2003/0038

  by brazing · CPC title