Galleryless piston with connection to pockets

Patent metadata

Field	Value
Publication number	US-10352270-B2
Application number	US-201715441659-A
Country	US
Kind code	B2
Filing date	Feb 24, 2017
Priority date	Mar 1, 2016
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A piston galleryless piston capable achieving improved thermal efficiency, fuel consumption, and engine performance is provided. The piston includes an undercrown surface exposed from an underside of the piston, a ring belt, pin bosses, and a pair of skirt panels coupled to the pin bosses by struts. The piston includes an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels, struts, and pin bosses. The piston also includes a pair of outer pockets extending along the undercrown surface and each being surrounded by a portion of the ring belt, one of the pin bosses, and the struts coupling the one pin boss to the skirt panels. Each pin boss includes an opening extending from the inner undercrown region to one of the outer pockets for conveying cooling oil. The opening is located between a pin bore of the associated pin boss and the undercrown surface.

First claim

The invention claimed is:

1. A piston, comprising:
an upper wall including an undererown surface exposed from an underside of said piston,
a ring belt depending from said upper wall and extending circumferentially around a center axis of said piston,
a pair of pin bosses depending from said upper wall,
a pair of skirt panels depending from said ring belt and coupled to said pin bosses by struts,
an inner undercrown region extending along said undererown surface and surrounded by said skirt panels and said struts and said pin bosses,
a first outer pocket and a second outer pocket each extending along said undercrown surface,
said first outer pocket being surrounded by a portion of said ring belt, one of said pin bosses, and two off, said struts,
said second outer pocket being surrounded by another portion of said ring belt, another one of said pin bosses, and another two of said struts, and
an opening extending through one of said pin bosses from said inner undercrown region to one of said outer pockets.

2. The piston of claim 1 , wherein said opening is disposed between said undercrown surface and a pin bore of said pin boss.

3. The piston of claim wherein said opening and a pin bore of said pin boss each present a cross-sectional area when said piston is viewed in cross-section from a side facing said pin boss, and said cross-sectional area of said opening is less than said cross-sectional area of said pin bore.

4. The piston of claim 3 , wherein said cross-sectional area of said opening is 10% to 50% of said cross-sectional area of said pin bore.

5. The piston of claim 1 , wherein said opening has a length extending from said undercrown surface to a lower surface of said opening and a width extending between opposite side surfaces of said opening, and said width is greater than said length.

6. The piston of claim 1 , wherein when said piston is viewed in cross-section in a direction facing said pin boss, said undercrown surface presents a cross-sectional shape which is upwardly curved along said opening relative to a center of said opening, said opening includes a lower surface which is upwardly curved along said opening relative to a center of said opening, and said opening includes side surfaces which are concave relative to a center of said opening.

7. The piston of claim 1 , wherein when said piston is viewed in cross-section in a direction facing said pin boss said undercrown surface presents u cross-sectional shape which is straight along said opening, said opening includes a lower surface which is straight along said opening, and said opening includes side surfaces which are concave relative to a center of said opening.

8. The piston of claim 1 , wherein said pin boss including said opening also includes a pin bore, and when said piston is viewed in cross-section along a width of said pin bore, said undercrown surface is convex along said opening relative to a center of said opening, and a lower surface of said opening is straight along said opening.

9. The piston of claim 1 , wherein said pin boss including said opening also includes a pin bore, and when said piston is viewed in cross-section along a width of said pin bore, a first portion of said undercrown surface extending tom said inner undercrown region is straight along said opening, and a second portion of said undercrown surface extending from said first portion to said outer pocket is convex along said opening relative to a center of said opening.

10. The piston of claim 1 , wherein said piston includes a body formed of a single piece of material, said body includes said upper wall, said ring belt, said pin bosses, and said skirt panels.

11. The piston of claim 10 , wherein said material of said body is formed of steel.

12. The piston of claim 1 , wherein said piston does not include a cooling gallery floor or other feature bounding or partially bounding a cooling gallery.

13. The piston of claim 1 including a body formed of a single piece of material,
said material of said body is formed of steel,
said body does not have a cooling gallery floor or other features bounding or partially bounding a cooling gallery,
said body includes said upper wall presenting an upper combustion surface,
said upper combustion surface is a non-planar surface around said center axis,
said ring belt includes a top land and a plurality of ring grooves extending circumferentially around said center axis and along an outer diameter of said piston,
said pin bosses are disposed inwardly of said ring belt and provide a pair of laterally spaced pin bores surrounding a pin bore axis,
said pair of skirt panels are located diametrically opposite one another,
said undercrown surface is disposed radially inwardly of said ring belt,
said undercrown surface is not bounded by an enclosed or partially enclosed cooling gallery,
a first portion of said undercrown surface is provided by said inner undercrown region and a second portion of said undercrown surface is provided by said outer pockets,
said inner undererown region is located at said center axis and is surrounded by said pin bosses and said skirt panels and said struts,
said undercrown surface located in said inner undercrown region is concave when viewed from the bottom of said piston,
said outer pockets are located outwardly of said pin bosses,
said opening of said pin, boss is disposed between said undercrown surface and said pin bore of said pin boss,
said opening of said pin boss is spaced from said pin bore by a portion of said pin boss,
said opening of said phi boss and said pin bore of said pin boss each present a cross-sectional area when said piston is viewed in cross-section in a direction facing said pin boss,
said cross-sectional area of said opening is 10% to 50% of said cross-sectional area of said pin bore,
said opening extends from said undercrown surface to a lower surface with side surfaces connecting said undercrown surface and said lower surface;
said opening of said pin boss has a length extending from said undercrown surface to said lower surface and a width extending between said opposite side surfaces which is greater than said length, and
both of said pin bosses include said opening.

14. A method of manufacturing a piston, comprising the steps of:
providing a body including an upper wall, the upper wall including an undercrown surface exposed from an underside of the piston; a ring belt depending m the upper wall and extending circumferentially around a center axis of the piston; a pair of pin bosses depending from the upper wall; a pair of skirt panels depending from the ring belt and coupled to the pin bosses by struts; an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels and the struts and the pin bosses; a first outer pocket and a second outer pocket each extending along the undercrown surface; the first outer pocket being surrounded by a portion of the ring belt, one of the pin bosses, and two of the struts; the second outer pocket being surrounded by another portion of the ring belt, another cane of the pin bosses, and another two of the struts; and
forming an opening extending through one of the pin bosses from the inner undercrown region to one of the outer pockets.

15. The method of claim 14 , wherein the step of forming the opening includes machining the opening through the pin boss.

16. The method of claim 14 , wherein the body is a single piece of material, and the step of providing the body includes forging or casting the body.

17. The method of claim 16 , wherein the

Assignees

• Tenneco Inc

Inventors

• Weinenger Michael
• Riffe Jeffrey L

Classifications

• F02F2200/04

  Forging of engine parts · CPC title

• F02F3/22 Primary

  the fluid being liquid · CPC title

• F02F3/20 Primary

  the means being a fluid flowing through or along piston · CPC title

• F02F3/26

  having combustion chamber in piston head (the surface thereof being covered F02F3/14) · CPC title

• F02F2200/06

  Casting · CPC title