| 摘要 |
PURPOSE:To accelerate the atomization and gasification of injected fuel by partially opening an air bleed passage near the nozzle hole of the secondary fuel injection nozzle directly injecting the fuel into an operation chamber to blowout air in a specified operation range. CONSTITUTION:A control unit 20 judges the operation range of an engine 1 from a throttle opening (a), boost pressure (b) and the number of engine revolutions (c), and causes the secondary fuel injection nozzle 16 to directly inject fuel into an operation chamber 15 instead of the primary fuel injection nozzle 14 for stratifying the fuel on the side of ignition plugs 111, 112 in an intake operation chamber 15 during a light load. A valve 17 is opened at the same time to blowout air passing through an air bleed passage 18 from the nearby part of a blowouting part 16a for accelerating fuel atomization. In the operation range where knocking is apt to occur, the air is not supplied through said air bleed passage 18, and the fuel is injected toward the rotor recess part 12 of a rotor flank surface 13 for its cooling. Thus the combustion efficiency of an engine can be improved, and the occurrence of the knocking can be also prevented. |
