Combustion Chamber with Double Convex Surfaces and Double Concave Surfaces

• US 20100108044A1
• Filed: 11/06/2008
• Published: 05/06/2010
• Est. Priority Date: 11/06/2008
• Status: Abandoned Application

• Current Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Original Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Inventors: LIU, ZHENGBAI
• Application Number:
  US12/265,771
• Publication Number:
  US 20100108044A1
• Time in Patent Office: Days
• US Class Current: 123/664
• CPC Class Codes: F02B 23/0672 Omega-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder center axis the surrounding wall being exactly vertical F02B23/0696
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A combustion chamber bowl is defined in a crown of a piston for use in a cylinder of a diesel engine. The combustion chamber bowl includes a center convex spherical portion, first and second annular concave portions and an annular convex portion. The center convex spherical portion is elevated relative to a bottom plane of the combustion chamber bowl and smoothly transitions into the first concave annular portion which transitions smoothly into the second concave annular portion. The second concave annular portion smoothly transitions into the convex annular portion which smoothly transitions into the top surface of the piston crown.

Claims

1. A combustion chamber bowl defined in a crown of a piston, the piston having a central axis, the piston for use in a cylinder of a diesel engine, the combustion chamber bowl comprising:

a center portion being elevated relative to a bottom plane of the combustion chamber bowl, the center portion defined by a portion of a sphere, the sphere having a spherical radius, and the combustion chamber bowl having a first concave annular surface smoothly transitioned from an outer perimeter of said center portion, said first concave annular surface having a first concavity radius, and a second concave annular surface smoothly transitioned from an outer perimeter of the first concave annular surface, said second concave annular surface having a second concavity radius, and a convex annular surface smoothly transitioned from an outer perimeter of said second concave annular surface, said convex annular surface having a convexity radius and smoothly transitioning into a top surface of the crown of said piston.

2. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1, and the piston has a diameter D1 and a center axis A2 that is a distance H3 away from the combustion chamber bowl center axis A1, wherein the distance H3 is between 0.0 and 0.08D1.

3. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1, and the piston has a diameter D1 and a center axis A2 that is coincident with the combustion chamber bowl axis A1.

4. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1, and the piston has a diameter D1 and a center axis A2, and the spherical radius of the convex spherical surface has an origin located a distance H4 below the point of intersection of the combustion chamber bowl axis A1 with a bottom plane of the combustion chamber bowl, and the distance H4 is between 0.0 and 0.35D1.

5. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1, and the piston has a diameter D1 and a center axis A2, and the spherical radius of the convex spherical surface has an origin located a distance H4 below the point of intersection of the combustion chamber bowl axis A1 with a bottom plane of the combustion chamber bowl, and the distance H4 is about 0.164D1.

6. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the piston has a diameter D1 and a center axis A2, the ratio of D2/D1 is greater than 0.44 and less than 0.84.

7. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the piston has a diameter D1 and a center axis A2, the ratio of D2/D1 is about 0.63.

8. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, the piston has a diameter D1 and a center axis A2, and the convex annular surface has diameter D3, the ratio of D3/D2 is greater than 0.69 and less than 0.999.

9. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, the piston has a diameter D1 and a center axis A2, and the convex annular surface has diameter D3, the ratio of D3/D2 is about 0.98.

10. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, the piston has a diameter D1 and a center axis A2, and the spherical radius is R20, the ratio of R20/D2 is greater than 0.18 and less than 0.68.

11. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, the piston has a diameter D1 and a center axis A2, and the spherical radius is R20, the ratio of R20/D2 is about 0.42.

12. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a maximum diameter D2 and a depth H1 to a bottom plane of the combustion chamber bowl, the ratio of H1/D2 is greater than 0.14 and less than 0.44.

13. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a maximum diameter D2 and a depth H1 to a bottom plane of the combustion chamber bowl, the ratio of H1/D2 is about 0.24.

14. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the convex spherical surface has a height H2 from a bottom plane of the combustion chamber bowl, and the ratio of H2/D2 is greater than 0.11 and less than 0.41.

15. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the convex spherical surface has a height H2 from a bottom plane of the combustion chamber bowl, and the ratio of H2/D2 is about 0.16.

16. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the first concavity radius is R22, the ratio of R22/D2 is greater than 0.06 and less than 0.36.

17. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the first concavity radius is R22, the ratio of R22/D2 is about 0.12.

18. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the second concavity radius is R24, the ratio of R24/D2 is greater than 0.16 and less than 0.66.

19. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the second concavity radius is R24, the ratio of R24/D2 is about 0.41.

20. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the convexity radius is R26, the ratio of R26/D2 is greater than 0.01 and less than 0.11.

21. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2, and the convexity radius is R26, the ratio of R26/D2 is about 0.034.

22. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2 and a depth H1 to a bottom plane of the combustion chamber bowl, the piston has a diameter D1 and a center axis A2, the convex spherical surface has a height H2 from the bottom plane of the combustion chamber bowl, the spherical radius is R20, the first concavity radius is R22, the second concavity radius is R24, the convex annular surface has diameter D3, and the convexity radius is R26:

the ratio of D2/D1 is greater than 0.44 and less than 0.84;

the ratio of D3/D2 is greater than 0.69 and less than 0.999;

the ratio of R20/D2 is greater than 0.18 and less than 0.68;

the ratio of H1/D2 is greater than 0.14 and less than 0.44;

the ratio of H2/D2 is greater than 0.11 and less than 0.41;

the ratio of R22/D2 is greater than 0.06 and less than 0.36;

the ratio of R24/D2 is greater than 0.16 and less than 0.66; and

the ratio of R26/D2 is greater than 0.01 and less than 0.11.

23. The combustion chamber bowl of claim 22, wherein the piston center axis A2 is a distance H3 away from the combustion chamber bowl center axis A1, wherein the distance H3 is between 0.0 and 0.08D1.

24. The combustion chamber bowl of claim 23, wherein the spherical radius of the convex spherical surface has an origin located a distance H4 below the point of intersection of the combustion chamber bowl axis A1 with the bottom plane of the combustion chamber bowl, and the distance H4 is between 0.0 and 0.35D1.

25. The combustion chamber bowl of claim 1, wherein the combustion chamber bowl has a combustion chamber bowl center axis A1 and a maximum diameter D2 and a depth H1 to a bottom plane of the combustion chamber bowl, the piston has a diameter D1 and a center axis A2, the convex spherical surface has a height H2 from the bottom plane of the combustion chamber bowl, the spherical radius is R20, the first concavity radius is R22, the second concavity radius is R24, the convex annular surface has diameter D3, and the convexity radius is R26:

the ratio of D2/D1 is about 0.63;

the ratio of D3/D2 is about 0.98;

the ratio of R20/D2 is about 0.42;

the ratio of H1/D2 is about 0.24;

the ratio of H2/D2 is about 0.16;

the ratio of R22/D2 is about 0.12;

the ratio of R24/D2 is about 0.41; and

the ratio of R26/D2 is about 0.034.

26. The combustion chamber bowl of claim 25, wherein the spherical radius of the convex spherical surface has an origin located a distance H4 below the point of intersection of the combustion chamber bowl axis A1 with the bottom plane of the combustion chamber bowl, and the distance H4 is between 0.0 and 0.35D1.