| 摘要 |
PURPOSE:To keep off any abnormal rise in back pressure by detecting any malfunction in an exhaust cut valve controlling the drive of a second supercharger being driven only at a high flow driving range, and when the malfunction is the case, controlling exhaust energy related to a fist supercharger being normally driven so as to be lowered. CONSTITUTION:In a supercharged engine, installing an exhaust cut valve 5, opening a second exhaust passage 3b only at a high flow side driving range, in this passage 3b leading exhaust gas to a turbine 2a of a second turbosupercharger 2, a detecting means 51, detecting an opening malfunction of the exhaust cut valve 5 on the basis of each output of an air flow meter 16 and a pressure sensor 54 detecting pressure in the downstream of a compressor 1b of a first turbosupercharger 1 being normally driven is installed in a control unit 50 controlling the exhaust cut valve 5 or the like. When this opening malfunction is detected, a waste gate valve 11 is opened by an exhaust energy lowering means 62, and exhaust energy acting on the first supercharger 1 is made so as to be lowered. |
