| 摘要 |
PURPOSE:To improve startability of an engine and reduce its vibration and noise at low loaded time of the engine, while suppressing the generation of unburned gas smoke, by performing a great amount of exhaust gas recirculation (EGR) in addition to an intake throttle. CONSTITUTION:If cranking of an engine is started, air flows from an exhaust pipe 6 in an exhaust gas recirculation (EGR) gas introducing pipe 23 in an initial cycle, and is introduced to an intake pipe 5. While air, introduced and fed into a cylinder, is used for combustion, and exhaust gas flows out into the exhaust pipe 6. If the engine increases its speed to, for instance, at least 400rpm, an actuator 22 is operated by an unbruned component detecting means 25 to open a subthrottle valve 10b and supply fresh air. Then a main throttle valve 10a and an EGR control valve 10c, provided in the EGR passage 23, are operated interlocking in such a manner that the EGR control valve 10c is fully opened when the main throttle valve 10a is fully closed. |
