| 摘要 |
PROBLEM TO BE SOLVED: To prevent fuel consumption deterioration caused by combustion deterioration in driving in a cold state, when recirculating part of an exhaust gas to an intake side to combust the gas again in a cylinder.SOLUTION: An EGR passage 20 is provided in communication downstream a catalytic converter 10, and the EGR passage 20 is divided into a first EGR passage 20a and a second EGR passage 20b via a switching valve 21. The first EGR passage 20a is brought into communication with an upstream side of a compressor 8a of a turbosupercharger 8 from the switching valve 21 via an EGR cooler 22 and an EGR valve 23, and the second EGR passage 20b is brought into communication with an intake passage 3 downstream a throttle valve 6 from the switching valve 21 directly. The first EGR passage 20a is used to perform EGR after an engine is warmed up, the second EGR passage 20b is used to perform the EGR in a cold state of the engine, and fuel consumption deterioration caused by combustion deterioration in driving in the cold state is thereby prevented. |
