| 摘要 |
PURPOSE:To prevent incomplete combustion of mixture that is possibly caused when the fuel injection timing is delayed for the purpose of reducing NOx, by shaping a subsidiary-chamber nozzle communicating a subsidary combustion chamber with a main combustion chamber such that ridge lines of said nozzle in its particular cross section are inclined in a specific tapered form. CONSTITUTION:A main combustion chamber 1 and a subsidiary combustion chamber 2 are comunicated with each other via a subsidiary-chamber nozzle 3. Here, the nozzle 3 is shaped in such a tapered form that the inclination angles OL, OR of ridges lines in the cross section of the nozzle 3 taken in the plane involving the center line A-A of the subsidiary combustion chamber 2 and the center line B-B satisfy the following relationship thetaL<thetaR. That is, the opening area at one end of the nozzle 3 locted on the side of the subsidiary combustion chamber 2 is made smaller than that of the nozzle 3 locted on the side of the main combustion chamber 1. With such an arrangement, ejection of gas from the subsidiary combustion chamber 2 to the main combustion chamber 1 is prevented even if ignition is caused in the subsidiary combustion chamber 2 during downward stroke of a piston 7 by delaying the ignition timing for the purpose of reducing NOx. Therefore, it is enabled to promote and stabilize combustion in the subsidiary combustion chamber 2. |
