STEEL PISTON WITH COOLING GALLERY AND METHOD OF CONSTRUCTION THEREOF

• US 20140352650A1
• Filed: 08/14/2014
• Published: 12/04/2014
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: Tenneco Incorporated (Apollo Global Management, Inc.)
• Original Assignee: Federal-Mogul Corporation (Apollo Global Management, Inc.)
• Inventors: Muscas, Florin, Matsuo, Eduardo H.
• Granted Patent: US 10,590,884 B2
• Time in Patent Office: Days
• US Class Current: 123/193.6
• CPC Class Codes: F02F 2003/0061 by welding
• CPC Class Codes: F02F 3/003 the parts being connected by casting, brazing, welding or clamping
• CPC Class Codes: F02F 3/22 the fluid being liquid
• CPC Class Codes: Y10T 29/49256 with assembly or composite article making

Abstract

A piston and method of construction is provided. The piston includes a top part fixed to a bottom part. The top part has an uppermost surface with annular inner and outer upper joining surfaces depending therefrom. The bottom part has a pair of pin bosses with pin bores aligned with one another along a pin bore axis; a pair of upwardly extending annular inner and outer lower joining surfaces and a combustion bowl wall. Inner and outer weld joints fix the inner and outer upper and lower joining surfaces to one another. An annular cooling gallery is formed laterally between the upper and lower joining surfaces. The inner weld joint joining the top part to the bottom part is located within the combustion bowl wall and configured to minimized the compression height of the piston.

Claims

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

a top part having an uppermost surface with annular inner and outer upper joining surfaces depending from said uppermost surface;

a bottom part having a pair of pin bosses providing a pair of laterally spaced pin bores aligned with one another along a pin bore axis and having a pair of upwardly extending annular inner and outer lower joining surfaces joined by separate respective inner and outer weld joints to said inner and outer upper joining surfaces with an annular cooling gallery formed radially between said upper joining surfaces and radially between said lower joining surfaces, said bottom part having a combustion bowl wall recessed below said uppermost surface, said combustion bowl wall having a thickness extending between an upper apex and a lower apex underlying said upper apex with an annular valley surrounding said upper apex and said lower apex; and

wherein said thickness is substantially constant.

2. The piston of claim 1 wherein said uppermost surface has an outer diameter and further including a pair of skirt panels on opposite sides of said pin bore axis, said skirt panels having a radially extending thickness ranging between about 2.0% to 3.0% of said outer diameter.

3. The piston of claim 2 wherein said combustion bowl wall thickness is about 2.5% to 4.0% of said outer diameter.

4. The piston of claim 1 wherein a compression height extends between said pin bore axis and said uppermost surface and said uppermost surface has an outer diameter, said compression height having a ratio to said outer diameter between about 38% to 45%.

5. The piston of claim 1 wherein said top part and said bottom part extend along a longitudinal central axis and said cooling gallery is non-concentric with said longitudinal central axis.

6. The piston of claim 5 wherein said combustion bowl wall has a uniform thickness.

7. The piston of claim 5 wherein said cooling gallery is asymmetrical about said longitudinal central axis.

8. The piston of claim 5 wherein said cooling gallery has an oil inlet with an oil deflector cast as one piece with said bottom part, said oil deflector extending radially across said oil inlet to substantially bifurcate said oil inlet.

9. The piston of claim 1 wherein said top part and said bottom part extend along a longitudinal central axis and said cooling gallery undulates relative to said longitudinal central axis.

10. The piston of claim 9 wherein said cooling gallery has a floor, said floor rising in smooth undulating fashion over said pin bores.

11. The piston of claim 1 further comprising a pair of skirt panels configured diametrically opposite one another, each of said skirt panels having opposite sides extending generally parallel to a central longitudinal axis and being operably joined to said pin bosses, each of said skirt panels having a continuously varying wall thickness extending between said opposite sides.

12. The piston of claim 11 wherein each of said skirt panels have central regions between said opposite sides, said central regions having a thickness about 5% less than a thickness of said skirt panels at said opposite sides.

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

a top part having an uppermost surface with annular inner and outer upper joining surfaces depending from said uppermost surface;

a bottom part having a pair of pin bosses providing a pair of laterally spaced pin bores axially aligned along a pin bore axis and having a pair of upwardly extending annular inner and outer lower joining surfaces joined by separate respective inner and outer weld joints to said inner and outer upper joining surfaces with an annular cooling gallery formed radially between said upper joining surfaces and radially between said lower joining surfaces, said top part and said bottom part forming a piston head region having an outer diameter; and

a compression height extending between said uppermost surface of said top part and said pin bore axis, said compression height ranging between about 38% to 45% of said piston head region outer diameter.

14. The piston of claim 13 wherein said bottom part includes a combustion bowl wall having a uniform thickness.

15. The piston of claim 13 wherein said top part and said bottom part extend along a longitudinal central axis and said cooling gallery is non-concentric with said longitudinal central axis.

16. The piston of claim 15 wherein said cooling gallery is asymmetrical about said longitudinal central axis.

17. The piston of claim 15 wherein said cooling gallery has an oil inlet with an oil deflector cast as one piece with said bottom part, said oil deflector extending radially across said oil inlet to substantially bifurcate said oil inlet.

18. The piston of claim 13 wherein said top part and said bottom part extend along a longitudinal central axis and said cooling gallery undulates relative to said longitudinal central axis.

19. The piston of claim 18 wherein said cooling gallery has a floor provided by said bottom part, said floor rising in smooth undulating fashion over said pin bores.

20. The piston of claim 13 further comprising a pair of skirt panels configured diametrically opposite one another, each of said skirt panels having opposite sides extending generally parallel to a central longitudinal axis and being operably joined to said pin bosses, each of said skirt panels having a continuously varying wall thickness extending between said opposite sides.

21. The piston of claim 13 wherein each of said skirt panels have central regions between said opposite sides, said central regions having a thickness about 5% less than a thickness of said skirt panels at said opposite sides.