| 摘要 |
PROBLEM TO BE SOLVED: To improve the purifying performance of a catalyst by avoiding the deterioration of the catalyst, or the like.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, and an exhaust gas recirculation device 90 for cooling exhaust gas after passing through a catalyst 48a with a cooling device 93, and then recirculating it into the exhaust collection part 35. In a high-load and high-speed region A5 where an engine load is higher than a predetermined reference load T3 and an engine speed N2 is higher than a predetermined reference speed, the exhaust gas after passing through the catalyst 48a is recirculated into the exhaust collection part 35 by the exhaust recirculation device 90, and the negative pressure changing means 39 is controlled toward increasing the negative pressure in the exhaust collection part 35.SELECTED DRAWING: Figure 1 |
