| 摘要 |
PROBLEM TO BE SOLVED: To suppress heat deterioration of an exhaust pipe and a catalyst in a proper balance, by using a waste gate valve.SOLUTION: An engine 10 includes a supercharger 36, a waste gate valve (WGV) 44, and an air bypass valve (ABV) 50, and the like. An exhaust passage 20 has an upstream exhaust pipe part 20a as a part upstream a turbine 38, and an ECU 80 acquires a temperature of the upstream exhaust pipe part 20a as an upstream exhaust pipe temperature. Further, the ECU 80 increases an opening of the WGV 44, when a catalyst temperature is higher than an OT temperature (heat-deterioration start temperature) and the upstream exhaust pipe temperature is higher than the catalyst temperature. On the other hand, the opening of the WGV 44 is decreased and an opening of the ABV 50 is increased, when the catalyst temperature is higher than the OT temperature and the upstream exhaust pipe temperature is lower than the catalyst temperature. Therefore, heat deterioration of the upstream exhaust pipe part 20a and the catalyst 26 can be suppressed in a proper balance. |
