Diesel combustion chamber
View Patent ↗A combustion chamber assembly for use in a diesel engine includes a combustion chamber being defined intersecting a crown of a piston, the combustion chamber being defined by a first curved surface having a reentrancy formed proximate a first curved surface first end and having a post formed proximate a first curved surface second end, a corner being formed at a juncture of the first curved surface second end and the post, adjacent surfaces being direct smooth junctures. A piston and a method of forming a combustion chamber are further included.
1. A combustion chamber assembly for use in a diesel engine, comprising:
a combustion chamber being formed free of flat surfaces and being defined intersecting a crown of a piston, the combustion chamber being defined by a first curved surface having a reentrancy formed proximate a first curved surface first end and having a post formed proximate a first curved surface second end, a corner being formed at a juncture of the first curved surface second end and the post, adjacent surfaces having smooth junctures therebetween.
2. The combustion chamber assembly of claim 1 , a combustion chamber center portion being defined at least in part by the post, a post surface being a convex spherical surface, the spherical surface having a radius and an origin, the spherical surface radius being substantially greater than a radius of the first curved surface; and
the combustion chamber first curved surface being a concave annular surface and having an origin of the radius, the first curved surface providing a minor part of the combustion chamber reentrancy.
3. The combustion chamber assembly of claim 2 , wherein the reentrancy is formed by four sequentially joined annular surfaces in cooperation with the first curved surface.
4. The combustion chamber assembly of claim 3 , the four sequentially joined annular surfaces and the first curved surface comprising three concave annular surfaces and two convex annular surfaces.
5. The combustion chamber assembly of claim 2 , wherein the origin of the post spherical surface is disposed on the center axis of the combustion chamber, the center axis of the combustion chamber being coaxial with a center axis of the piston.
6. The combustion chamber assembly of claim 2 , wherein the ratio of a radius of a center portion convex spherical surface, RS 1 , of the combustion chamber to a maximum bowl diameter, D 2 , is greater than 0.15 and less than 0.65.
7. The combustion chamber assembly of claim 6 , wherein the ratio of the radius of the center portion convex spherical surface, RS 1 , of the combustion chamber to the maximum bowl diameter, D 2 , is substantially 0.497.
8. The combustion chamber assembly of claim 2 , wherein the ratio of a combustion chamber bowl diameter D 2 to a piston diameter D 1 is greater than 0.45 and less than 0.85.
9. The combustion chamber assembly of claim 8 , wherein the ratio of the combustion chamber bowl diameter D 2 to the piston diameter D 1 is preferably substantially 0.587.
10. The combustion chamber assembly of claim 2 , wherein the ratio of a diameter of the bowl lip D 3 to a maximum bowl diameter D 2 is greater than 0.45 and less than 0.995.
11. The combustion chamber assembly of claim 10 , wherein the ratio of the diameter of the bowl lip D 3 to the piston diameter D 2 is substantially 0.94.
12. The combustion chamber assembly of claim 2 , wherein the ratio of a concave annular surface R 2 to a maximum diameter of the bowl D 2 is between 0.05 and 0.35.
13. The combustion chamber assembly of claim 12 , wherein the ratio of the annular surface R 2 to the maximum diameter of the bowl D 2 is substantially 0.129.
14. The combustion chamber assembly of claim 2 wherein the ratio of a convex annular surface R 3 to a maximum diameter of the bowl D 2 is between 0.15 and 0.45.
15. The combustion chamber assembly of claim 14 , wherein the ratio of the annular surface R 3 to the maximum diameter of the bowl D 2 is substantially 0.292.
16. The combustion chamber assembly of claim 2 , wherein the ratio of a maximum bowl depth H 1 to a maximum bowl diameter D 2 is between 0.15 and 0.55.
17. The combustion chamber assembly of claim 16 , wherein the ratio of the maximum bowl depth H 1 to the maximum bowl diameter D 2 is preferably substantially 0.292.
18. The combustion chamber assembly of claim 2 , wherein a ratio of a height of the bowl post H 2 to a maximum bowl diameter D 2 is between 0.05 and 0.35.
19. The combustion chamber assembly of claim 18 , wherein the ratio of the bowl post height H 2 to the maximum bowl diameter D 2 is preferably substantially 0.181.
20. The combustion chamber assembly of claim 2 , wherein a ratio of a distance between the bowl reentrancy center and the piston top surface H 3 to a maximum bowl diameter D 2 is between 0.05 and 0.25.
21. The combustion chamber assembly of claim 20 , wherein a ratio of a distance between the bowl reentrancy center and the piston top surface H 3 to a maximum bowl diameter D 2 is preferably 0.056.
22. The combustion chamber assembly of claim 2 , wherein the ratio of the radius of the curved surface R 4 to the maximum bowl diameter D 2 is between 0.015 and 0.15.
23. The combustion chamber assembly of claim 22 , wherein the ratio of the radius of the curved surface R 4 to the maximum bowl diameter D 2 is preferably substantially 0.028.
24. The combustion chamber assembly of claim 2 , wherein the ratio of the radius of the curved surface R 5 to the maximum bowl diameter D 2 is between 0.05 and 0.25.
25. The combustion chamber assembly of claim 24 , wherein the ratio of the radius of the curved surface R 5 to the maximum bowl diameter D 2 is preferably substantially 0.073.
26. The combustion chamber assembly of claim 1 , wherein the juncture between the first curved surface and the post spherical surface is effected by an interposed small annular surface.
27. The combustion chamber assembly of claim 1 , wherein the combustion chamber is symmetrical about a combustion chamber center axis.
28. The combustion chamber assembly of claim 1 , the combustion chamber having a central axis, the combustion chamber central axis being coincident with a piston central axis.
29. A piston of a diesel engine having a combustion chamber assembly defined therein, comprising:
a combustion chamber being formed free of flat surfaces and being defined intersecting a crown of the piston, the combustion chamber being defined by a first curved surface having a reentrancy formed proximate a first curved surface first end and having a post formed proximate a first curved surface second end, a corner being formed at a juncture of the first curved surface second end and the post, adjacent surfaces having smooth junctures therebetween.
30. The piston of claim 29 , a combustion chamber center portion being defined at least in part by the post, a post surface being a convex spherical surface, the spherical surface having a radius and an origin, the spherical surface radius being substantially greater than a radius of the first curved surface; and
the combustion chamber first curved surface being a concave annular surface and having an origin of the radius, the first curved surface providing a minor part of the combustion chamber reentrancy.
31. The piston of claim 30 , wherein the reentrancy is formed by four sequentially joined annular surfaces in cooperation with the first curved surface.
32. The piston of claim 31 , the four sequentially joined annular surfaces and the first curved surface comprising three concave annular surfaces and two convex annular surfaces.
33. The piston of claim 30 , wherein the origin of the post spherical surface is disposed on the center axis of the combustion chamber, the center axis of the combustion chamber being coaxial with a center axis of the piston.
34. The piston of claim 29 , wherein the juncture between the first curved surface and the post spherical surface is effected by an interposed small annular surface.
35. The piston of claim 29 , wherein the combustion chamber is symmetrical about a combustion chamber center axis.
36. The piston of claim 29 , the combustion chamber having a central axis, the combustion chamber central axis being coincident with a piston central axis.
37. A method of forming a combustion chamber for use in a diesel engine, comprising:
forming a combustion chamber intersecting a crown of a piston free of flat surfaces, defining the combustion chamber by a first curved surface having a reentrancy formed proximate a first curved surface first end and having a post formed proximate a first curved surface second end, forming a corner at a juncture of the first curved surface second end and the post and forming adjacent surfaces with smooth junctures therebetween.
38. The method of claim 37 , including defining a combustion chamber center portion at least in part by the post, forming a post surface as a convex spherical surface, the spherical surface having a radius and an origin, and forming the spherical surface radius substantially greater than a radius of the first curved surface; and
forming the combustion chamber first curved surface as a concave annular surface and having an origin and a radius, the first curved surface providing a minor part of the combustion chamber reentrancy.
39. The method of claim 38 , including forming the reentrancy by four sequentially joined annular surfaces in cooperation with the first curved surface.
40. The method of claim 39 , including comprising the four sequentially joined annular surfaces and the first curved surface of three concave annular surfaces and two convex annular surfaces.
41. The method of claim 39 , including disposing the origin of the post on the center axis of the combustion chamber and disposing the center axis of the combustion chamber coaxially with a center axis of the piston.
42. The method of claim 37 , including effecting the juncture between the first curved surface and the post by an interposed small annular surface.
43. The method of claim 37 , including forming the combustion chamber symmetrically about a combustion chamber center axis.