| 摘要 |
PURPOSE:To prevent interference caused by confluence of exhaust gas by allowing exhaust gas flows discharged to both exhaust systems to make a confluent flow in series to both exhaust turbines at the time of a low speed and a low load and on the other hand, by allowing them to flow in parallel and individually at the time of a high speed and a high load. CONSTITUTION:Exhaust systems 15, 17 for discharging exhaust gas supplied from a plurality of cylinders of an engine while dividing the same exhaust gas into two system lines, and two turbochargers 9, 7 in which turbine units 33, 41 are positioned individually in the exhaust systems 15, 17, are provided. Communicating passages 31, 23 and control valves 45, 47, 37, 39 are provided in both exhaust systems 15, 17. Opening/closing operations of the control valves 45, 47, 37, 39 are controlled by a control circuit 49 so as to make exhaust gas discharged to both exhaust 15, 17 to be confluent in series to both turbine units 33, 41 at the time of a low speed and a low load and on the other hand, to flow individually in parallel at the time of high speed and a high load. It is thus possible to prevent fault in which function reduction of the turbo chargers 9, 7 may take place by interference following confluence of exhaust gas at the time of high speed. |
