| 摘要 |
PROBLEM TO BE SOLVED: To develop good exhaust performance by more accurately keeping a catalyst at an activating temperature or higher.SOLUTION: A control device for an engine includes a plurality of independent exhaust passages 31 extending from respective exhaust ports 7, an exhaust collection part 35 provided on the downstream sides of the independent exhaust passages 31 and forming a common space communicated with the independent exhaust passages 31, negative pressure changing means 39 capable of changing a negative pressure to be generated in the exhaust collection part 35, a catalyst 48a provided on the downstream side of the exhaust collection part 35, and an exhaust gas recirculation device 90 communicating the downstream side of the catalyst 48a and the upstream side of the exhaust collection part 35 with each other for recirculating exhaust gas after passing through the catalyst 48a, into the exhaust collection part 35. In a region A1 where an exhaust temperature is a catalyst activating temperature or lower, the exhaust gas after passing through the catalyst is recirculated into the exhaust collection part 35 by the exhaust gas recirculation device 90 and the negative pressure to be generated in the exhaust collection part 35 is increased.SELECTED DRAWING: Figure 1 |
