| 摘要 |
PURPOSE:To make it possible to finely control the flow rate of exhaust recirculation gas by connecting the downstream section of an exhaust gas recirculation passage to a bypass passage upstream of a flow control valve, and by providing a change-over valve in the connection between both passages so that a flow control valve is also used for exhaust recirculation control. CONSTITUTION:Intake-air introduced into an intake-air passage 13 through an air-cleaner 12 is mixed with fuel jetted from a fuel injection valve 17 after the flow rate thereof is regulated by a throttle valve 16, and then is fed into a combustion chamber 5 through an intake-air valve 7. Further, a flow rate control valve 24 for controlling the flow rate of bypass intake-air or the flow rate of exhaust recirculation gas is disposed in a passage bypassing the throttle valve 16. In this arrangement, the downstream section 25a of an exhaust gas recirculation passage 25 connected to an exhaust passage 8 is connected to the bypass passage 23 upstream of the flow control valve 24. Further, a change- over valve 27 is disposed in the connection between both passages 25, 23, and is change over by a control device 22 in accordance with the operating condition of an engine. |
