Compact one piece cooled piston and method

• US 6,286,414 B1
• Filed: 08/16/1999
• Issued: 09/11/2001
• Est. Priority Date: 08/16/1999
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Kruse, Brian K.
• Primary Examiner(s): Ryznic, John E.
• Application Number:
  US09/375,322
• Time in Patent Office: 757 Days
• Field of Search: 921/76, 921/81.R, 921/86, 922/09, 922/14, 922/38, 123/193.6
• US Class Current: 92/186
• CPC Class Codes: F02F 2003/0061 by welding
• CPC Class Codes: F02F 2200/04 Forging of engine parts
• 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: F05C 2201/0448 Steel

Abstract

A compact one piece piston for use in an internal combustion engine has a compression height (“CH”) of between 55 percent and 70 percent the piston diameter (“D”) and a closed piston cooling gallery defined by a piston ring belt welded at spaced locations to a piston body and to a flange portion of the piston body. The flange portion supports a second end of the piston ring belt and resists deflection of the piston ring belt. The closed piston cooling gallery is configured to promote heat transfer and piston cooling by facilitating shaking of a cooling fluid located within the closed piston cooling gallery during reciprocal piston movement. A piston skirt extending from the flange provides additional strength and rigidity.

Claims

1. A compact one piece piston, comprising:

a piston body having a top surface and a longitudinal axis;

a support portion extending in a direction longitudinally from said piston body and defining a pair of spaced apart pin bosses, said pin bosses having a pin bore and a pin bore axis oriented transverse the longitudinal axis, said pin bore axis being spaced from said top surface a preselected compression height distance “

CH”

;

a flange portion extending in a direction radially from said piston body at a preselected location between the top surface and the pin bore;

a piston ring belt portion having a preselected diameter “

D” and

being disposed about said piston body, said piston ring belt portion being connected to said piston body and to said flange portion by welding, said piston body, flange portion and ring belt portion defining a closed piston cooling gallery, said compression height distance “

CH”

being within a magnitude of between 55 percent and 70 percent the magnitude of diameter “

D”

.

2. The compact one piece piston, as set forth in claim 1, wherein said closed piston cooling gallery having first and second spaced apart extreme end locations defining a preselected longitudinal gallery length “

L”

, said length being of a magnitude sufficient to enable substantial shaking of a cooling fluid contained within the closed piston cooling gallery.

3. The compact one piece piston, as set forth in claim 2, wherein the length “

L”

of the closed piston cooling gallery being a function of the diameter “

D”

of the piston and within a range between 20 and 30 percent of the magnitude of the diameter “

D”

.

4. The compact one piece piston, as set forth in claim 2, wherein said piston ring belt portion having a plurality of spaced apart piston ring grooves disposed therein, said piston ring grooves being spaced axially relative to the longitudinal axis between the first and second extreme end locations of the closed piston cooling gallery.

5. The compact one piece piston, as set forth in claim 4, wherein said piston ring belt portion having first and second ends and an inside surface, said inside surface being welded to the piston body and said second end being welded to the flange portion.

6. The compact one piece piston, as set forth in claim 5, wherein said flange portion having a ring end portion, said ring end portion including a first side of a first piston ring groove of said plurality of piston ring grooves and said piston ring belt portion defining a second side of the first piston ring groove, said first and second sides being spaced a preselected distance apart, said welding connecting the flange portion to the second end of the piston ring belt portion being at a location between the first and second sides of the first piston ring groove.

7. The compact one piece piston, as set forth in claim 4, including a piston skirt having first and second spaced apart opposite skirt portions, said first and second skirt portions each being connected to the flange portion and the support portion.

8. The compact one piece piston, as set forth in claim 7, wherein said piston skirt extending from the flange portion in an axial direction relative to the longitudinal axis to a location past the pin bore axis.

9. The compact one piece piston, as set forth in claim 7, wherein said first and second skirt portions each are connected to the first and second spaced apart pin bosses.

10. The compact one piece piston, as set forth in claim 7, wherein said piston body, said support portion, said flange portion, and said piston skirt being forged in one piece from a steel material.

11. A method of producing a compact one piece piston having a top surface and a longitudinal axis;

comprising the steps of;

forging a one piece piston body having a head portion, a flange portion arranged in a substantially radial direction, and a support portion, said flange and support portions being connected to the head portion, said head portion having a top surface and said support portion having a pin bore axis spaced a preselected compression height distance “

CH”

from the top surface;

providing a cooling gallery disposed annularly about the piston body; and

connecting a piston ring belt portion to the piston body and closing off the cooling gallery, said ring belt having a preselected diameter “

D” and

said compression height distance “

CH”

being within a magnitude of between 55 percent and 70 percent the magnitude of diameter “

D”

.

12. The method, as set forth in claim 11, wherein the step of connecting the piston ring belt portion to the piston body includes the steps of:

welding an inside surface of the piston ring belt portion to the piston body; and

welding a second end of the piston ring belt to the flange portion.

13. The method, as set forth in claim 12, including the step of machining a plurality of axially spaced apart piston ring grooves in the piston ring belt.

14. The method, as set forth in claim 11, including the step of providing a forged piston skirt on the piston body, said piston skirt being connected to the flange portion and the support portion of the piston body.

15. A compact one piece piston for an internal combustion engine, comprising:

a cylinder having a cylinder bore disposed therein, said compact one piece piston being disposed in the cylinder bore and being adapted to reciprocally move in said cylinder bore, said compact one piece piston including;

a piston body having a top surface and a longitudinal axis;

a support portion extending in a direction longitudinally from said piston body and defining a pair of spaced apart pin bosses, said pin bosses having a pin bore and a pin bore axis oriented transverse the longitudinal axis, said pin bore axis being spaced from said top surface a preselected compression height distance “

CH”

;

a flange portion extending in a direction radially from said piston body at a preselected location between the top surface and the pin bore;

a piston ring belt portion having a preselected diameter “

D” and

being disposed about said piston body, said piston ring belt portion being connected to said piston body and to said flange portion by welding, said piston body, flange portion and ring belt portion defining a closed piston cooling gallery, said compression height distance “

CH”

being within a magnitude of between 55 percent and 70 percent the magnitude of the preselected diameter “

D”

;

said closed piston cooling gallery having first and second spaced apart extreme end locations defining a preselected longitudinal gallery length “

L”

, said length being of a magnitude sufficient to enable substantial shaking of a cooling fluid contained within the closed piston cooling gallery;

said piston ring belt portion having a plurality of spaced apart piston ring grooves disposed therein, said piston grooves being spaced axially relative to the longitudinal axis between the first and second extreme end locations of the closed piston cooling gallery; and

said piston ring belt portion having first and second ends and an inside surface, said inside surface being connected to the piston body by welding and said second end being connected to the flange portion by welding.