| 摘要 |
PURPOSE:To actively atomize and vaporize fuel and improve ignitability of an engine by injecting fuel and air against the spark plug in a combustion chamber by the control of a fuel injection valve and an air injection valve in a prescribed time from the latter half of a suction stroke to the compression stroke at a light load of the engine. CONSTITUTION:A primary and a secondary passages 8, 9 are provided in the combustion chamber 7 of each cylinder and a swirl control valve 10 which is controlled through an actuator 11 is provided in the passage 9. A fuel injection valve 21 is arranged to face a spark plug 20 and an air injection valve 22 is arranged in such a direction that the injected air is mingled with the injected fuel. When the engine load is light, at a prescribed time in the latter half of a compression stroke, fuel is injected against the spark plug 20 from the injection valve 21 to supply fuel mainly to the vicinity of the spark plug 20, which facilitates the ignition and combustion even the fuel quantity is small. In addition, air is injected at this time from the injection valve 22 to be mingled with the injected fuel, which allows efficient atomization and vaporization of the fuel in a short time and improves ignitability. |
