Piston With a Low Overall Height

• US 20190024606A1
• Filed: 08/29/2016
• Published: 01/24/2019
• Est. Priority Date: 08/28/2015
• Status: Abandoned Application

• Current Assignee: KS Kolbenschmidt GmbH (Rheinmetall AG)
• Original Assignee: KS Kolbenschmidt GmbH (Rheinmetall AG)
• Inventors: Weiss, Eberhard, Luz, Gerhard, Muller, Jochen, Ottliczky, Emmerich
• Application Number:
  US15/755,239
• Publication Number:
  US 20190024606A1
• Time in Patent Office: Days
• CPC Class Codes: B23K 20/129 specially adapted for particular articles or workpieces
• CPC Class Codes: B23K 2101/003 Pistons
• CPC Class Codes: B23P 15/10 pistons
• 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 3/10 having surface coverings F02F3/02 takes precedence
• CPC Class Codes: F02F 3/22 the fluid being liquid
• CPC Class Codes: F02F 3/26 having combustion chamber in piston head the surface thereof being covered F02F3/14

Abstract

The invention relates to a piston for an internal combustion engine having an upper part integrally joined to a lower part having a shaft and at least one pin bore. The upper part including a combustion chamber bowl recess and a piston crown with a crown edge. At least one joint is arranged in the region of a ring zone and in an outer wall of the combustion bowl recess, and the ratio of piston compression height (h₁) and the diameter of the piston (d₁) is less than 0.53.

Claims

1. A piston for an internal combustion engine, having an upper part joined by material bonding to a lower part, wherein the lower part comprises a shaft and at least one pin bore, wherein the upper part comprises a combustion bowl and a piston crown having a crown edge, characterized in that at least one joint is arranged in a region of a ring field and in an outer wall of the combustion bowl and a ratio of piston compression height (h₁) and diameter of the piston (d₁) is smaller than 0.53.

2. The piston of claim 1, wherein the joint in the outer wall of the combustion bowl is positioned above a finished combustion bowl base in a direction of a piston stroke axis.

3. The piston of claim 1, wherein the piston crown defines at least one recess.

4. The piston of claim 3, wherein the at least one recess defines at least one clearance which passes at least partially through the crown edge of the piston crown.

5. The piston of claim 3, wherein the at least one clearance is configured in a circular segment shape.

6. The piston of claim 3, wherein the at least one recess defines a first valve pocket.

7. The piston of claim 6 wherein the at least one recess defines a second valve pocket, wherein a distance (x₁) between a line positioned between a pressure side and counter-pressure side and a center point of the first valve pocket is larger than a distance (x₂) between the line and a center point of the second valve pocket.

8. The piston of claim 7, wherein the distance (x₁) is at least twice as large as the distance (x₂).

9. The piston of claim 1 further comprising a coating positioned on the piston shaft, the coating operable to reduce friction.

10. The piston of claim 1 further comprising a cooling duct.

11. The piston of claim 10, further comprising at least one elongated intake in communication with the cooling duct operable to provide the admission of oil to the cooling duct.

12. The piston of claim 11, wherein the cooling duct defines at least one molded-in recess in a cooling duct contour.

13. The piston of claim 12, wherein the at least one molded-in recess in the cooling duct is positioned at a point of impact of focal rays in the combustion bowl.

14. The piston of claim 1 wherein the upper part comprises a warm forged upper part.

15. A piston for an internal combustion engine comprising:

a lower part having a shaft defining at least one pin bore having a pin bore axis, the lower part oriented along a piston stroke axis perpendicular to the pin bore axis;

an upper part connected to the lower part at a joint, the upper part further having a top surface and defining a combustion bowl recess extending from the top surface toward the lower part;

the connected upper part and lower part further comprising;

a ring field extending radially from and longitudinally along the piston stroke axis, the joint positioned in the ring field;

a piston compression height (h1) defined between the pin bore axis and the upper part top surface;

a piston outer diameter (d1);

wherein a ratio of the piston compression height (h1) and the piston outer diameter (d1) is between 0.48 and 0.75.

16. The piston of claim 15 wherein the ratio of the piston compression height (h1) and the piston outer diameter (d1) is less than 0.53.

17. The piston of claim 16, wherein the piston compression height (h1) is between 70 millimeters and 90 millimeters, and the piston outer diameter (d1) is between 100 millimeters and 150 millimeters.

18. The piston of claim 15 wherein the upper part further defines a first recess in the top surface and extending toward the lower part.

19. The piston of claim 18 wherein the upper part further defines a first valve pocket positioned within the first recess.

20. The piston of claim 19, wherein:

the recess defines a clearance positioned through an outer edge of the upper part top surface; and

the first valve pocket includes a diameter (d4) between 35 millimeters and 55 millimeters.