| 摘要 |
PURPOSE: To reflux exhaust gas while a turbine is positively driven, return an exhaust gas under reduced temperature, and facilitate the supply of sufficient amount of air into engine by returning exhaust gas to an intake passage after a turbine of a supercharger is driven. CONSTITUTION: In a supercharger 4 of an internal combustion engine, an air- supplying cooler 10 and a bypass passage 11 bypassing the cooler 10 are provided on the downstream side of a compressor 6 in an intake passage 2 to switch the flow of intake to either of the cooler 10 side and the bypass passage 11 side by a change-over valve 12. Then, the downstream side of a turbine 5 and the upstream side of the compressor 6 are communicated with each other by a connection passage 8, and the connection passage 8 is opened or closed by an opening/closing valve 9. In this case, when the internal combustion engine is in a specified operating range on the basis of detected information of operating condition detecting means 21 to 23, exhaust gas is returned through the connection passage 8 to the intake passage 2, and the bypass passage 11 is controlled to be opened by switching the change-over valve 12. |
