Piston with cooling gallery and closed collar chamber

Patent metadata

Field	Value
Publication number	US-9657683-B2
Application number	US-201313928916-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Jun 27, 2012
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

Pistons and methods of making the same are disclosed. An exemplary piston assembly may include a piston crown and skirt. The crown may include a crown collar wall extending downward toward a free end of the crown collar wall. The skirt may include a pair of oppositely disposed pin bosses that each define piston pin bores configured to receive a piston pin for securing a connecting rod between the pin bosses. The skirt may further include a radially inner skirt mating surface abutted along a radially inner interface region with the radially inner crown mating surface, and a radially outer skirt mating surface abutted along a radially outer interface region with the radially outer crown mating surface such that a cooling gallery is substantially enclosed. The skirt may further include an inner collar wall extending upwards to the free end of the crown collar wall.

First claim

What is claimed is:

1. A piston, comprising:
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 crown including a crown collar wall extending downward to a free end; and
a piston skirt, including:
a pair of oppositely disposed pin bosses, the pin bosses each defining piston pin bores and cooperating to define a generally open central region configured to receive a connecting rod between the pin bosses;
a radially inner skirt mating surface abutted along a radially inner interface region with the radially inner crown mating surface;
a radially outer skirt mating surface abutted along a radially outer interface region with the radially outer crown mating surface such that the cooling gallery is substantially enclosed; and
a skirt collar wall disposed radially inwardly of the radially inner interface region and extending upwards to the free end of the crown collar wall;
wherein the crown collar wall cooperates with the skirt collar wall and the radially inner interface region to enclose an annular gallery to prevent fluid intrusion into the annular gallery; and
wherein a weld flashing extending from an associated pair of crown and skirt mating surfaces adjacent the crown and skirt collar walls is contained within the annular gallery;
wherein the crown collar wall cooperates with the skirt collar wall by overlapping one another in an unwelded joint to enclose the radially inner interface region formed between the radially inner skirt mating surface and the radially inner crown mating surface;
wherein at least one of the crown collar wall and the skirt collar wall defines an angled end surface, the angled end surface oriented at an oblique angle with respect to a longitudinal axis of the piston.

2. The piston of claim 1 , wherein the crown collar wall defines an upper angled end surface, and the skirt collar wall defines a lower angled end surface, the upper angled end surface oriented substantially parallel to the lower angled end surface.

3. The piston of claim 1 , wherein the crown collar wall is laterally aligned with the skirt collar wall.

4. The piston of claim 1 , wherein the crown and skirt are friction welded together along at least one of the radially inner and outer mating surfaces of the crown and skirt.

5. The piston of claim 1 , wherein the crown collar wall and skirt collar wall define opposing surfaces extending substantially perpendicular to a longitudinal axis of the piston.

6. The piston of claim 5 , wherein the opposing surfaces are oriented substantially parallel to at least one mated pair of the crown and skirt mating surfaces.

7. The piston of claim 1 , wherein the opposing surfaces of the crown collar wall and the skirt collar wall each define an axial distance from an associated crown mating surface and an associated skirt mating surface, respectively; and
wherein the axial distance is approximately equal to one half of an upset length associated with the associated crown and skirt mating surfaces.

8. A piston, comprising:
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 crown including a crown collar wall extending downward to a crown collar end; and
a piston skirt, including:
a pair of oppositely disposed pin bosses configured to receive a connecting rod between the pin bosses;
a radially inner skirt mating surface abutted along a radially inner interface region with the radially inner crown mating surface;
a radially outer skirt mating surface abutted along a radially outer interface region with the radially outer crown mating surface such that the cooling gallery is substantially enclosed; and
a skirt collar wall disposed adjacent one of the radially inner and radially outer interface regions and extending upwards to the free end of the crown collar wall;
wherein the crown collar wall cooperates with the skirt collar wall and the radially inner interface region to enclose an annular gallery to prevent fluid intrusion into the annular gallery; and
wherein a weld flashing extending from an associated pair of crown and skirt mating surfaces adjacent the crown and skirt collar walls is contained within the annular gallery;
wherein the crown collar wall cooperates with the skirt collar wall by overlapping one another in an unfused joint to enclose the radially inner interface region formed between the radially inner skirt mating surface and the radially inner crown mating surface;
wherein at least one of the crown collar wall and the skirt collar wall defines an angled end surface, the angled end surface oriented at an oblique angle with respect to a longitudinal axis of the piston.

9. The piston of claim 8 , wherein the skirt collar wall is disposed radially inwardly of the radially inner interface region.

10. A method, comprising:
providing 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;
abutting the inner and outer crown mating surface with corresponding inner and outer skirt mating surfaces of a piston skirt to form a radially inner interface region between the inner mating surfaces, a radially outer interface region between the outer mating surfaces, and a cooling gallery disposed between the radially inner and outer interface regions, the skirt including a pair of oppositely disposed pin bosses defining piston pin bores and cooperating to define a generally open central region configured to receive a connecting rod between the pin bosses;
forming a crown collar wall extending downward from the crown to a crown collar end;
providing a skirt collar wall disposed radially inwardly of the radially inner interface region and extending upwards to the free end of the crown collar wall, wherein the crown collar wall cooperates with the skirt collar wall and the radially inner interface region to enclose an annular gallery to prevent fluid intrusion into the annular gallery, and a weld flashing extending from an associated pair of crown and skirt mating surfaces adjacent the crown and skirt collar walls is contained within the annular gallery; and
defining wherein at least one of the crown collar wall and the skirt collar wall defines an angled end surface
wherein the crown collar wall cooperates with the skirt collar wall by overlapping one another in an unbonded joint to enclose the radially inner interface region formed between the radially inner skirt mating surface and the radially inner crown mating surface.

11. The method of claim 10 , further comprising enclosing the radially inner interface region from the central region with the inner collar wall.

12. The method of claim 10 , further comprising defining opposing surfaces of the crown and skirt collar walls, the opposing surfaces extending substantially perpendicular to a longitudinal axis of the piston.

13. The method of claim 10 , further comprising defining an axial distance from the opposing surfaces of the crown collar wall and the skirt collar wall to an associated crown mating surface and an associated skirt mating surface, respectively; and
establishing the axial distance as approximately equal to one half of an upset length associated with the associated crown and skirt mating surfaces.

14. The method of claim 10 , further comprising friction welding the radially inner and outer crown mating surfaces to the radially inner and outer skirt mating surfaces, respectiv

Assignees

• Mahle Int Gmbh

Inventors

• Wilder Montgomery L
• Seifried Matthias
• Edel Helmut
• Mueller Reiner

Classifications

• B23K20/12 Primary

  the heat being generated by friction; Friction welding · CPC title

• F02F3/003

  the parts being connected by casting, brazing, welding or clamping · CPC title

• B23K31/003

  relating to controlling of welding distortion · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title

• B23K2103/06

  Cast-iron alloys · CPC title