| US 7,472,678 B2 | ||
| Combustion chamber shape of direct injection type diesel engine | ||
| Keiichi Tsujimoto, Osaka (Japan); and Shunji Hamaoka, Osaka (Japan) | ||
| Assigned to Yanmar Co., Ltd., Osaka-shi (Japan) | ||
| Appl. No. 11/629,707 PCT Filed May 25, 2005, PCT No. PCT/JP2005/009545 § 371(c)(1), (2), (4) Date Dec. 15, 2006, PCT Pub. No. WO2006/006308, PCT Pub. Date Jan. 19, 2006. |
||
| Claims priority of application No. 2004-203257 (JP), filed on Jul. 09, 2004. | ||
| Prior Publication US 2007/0272191 A1, Nov. 29, 2007 | ||
| Int. Cl. F02B 23/02 (2006.01); F02B 23/06 (2006.01); F02F 3/26 (2006.01) | ||
| U.S. Cl. 123—299 [123/193.6; 123/276] | 4 Claims |
| 1. A combustion chamber shape of a direct injection type diesel engine having a combustion chamber formed in a recessed shape
in a piston top wall and injecting fuel at a predetermined nozzle hole angle into the combustion chamber from a nozzle hole
of a fuel injection valve having a nozzle hole center substantially on a cylinder center line,
wherein a wall face of the combustion chamber includes:
a conical mountain portion formed at a central portion in the combustion chamber and having such a slope angle and skirt end
diameter that fuel spray does not collide with the mountain portion;
a slope portion that inclines downward and outward from a skirt end of the mountain portion at a smaller angle than the slope
angle of the mountain portion and with which the fuel spray collides; and
a saucer portion which rises in an arc shape from an outer peripheral end of the slope portion to reach an outer peripheral
end of the combustion chamber and with which the fuel spray collides.
wherein, in the mountain portion, a ratio H2/H1 of a mountain portion height H2 from a combustion chamber bottom face to a
combustion chamber depth H1 is 0.7≤H2/H1≤1.0,
a ratio D1/B of a diameter D1 of a mountain portion top face to a bore diameter B is D1/B≤0.3, and
a ratio D2/B of a diameter D2 of the skirt end of the mountain portion to the bore diameter B is D2/B0.5.
|