| 摘要 |
PURPOSE:To detect something trouble earlier and make it alarmable by displaying a fact that an exhaust selector valve gets out of order at the opening side at a time when supercharging pressure in a state that only a main turbocharger is in supercharging operation is less than the map value. CONSTITUTION:An intake selector valve 18, opening or closing an intake passage, is installed downstream of a compressor 8b of a sub-turbocharger 8, while an exhaust selector valve 17, opening or closing an exhaust passage, is installed downstream or upstream of a turbine 8a. At a low speed range, the intake selector valve 18 and the exhaust selector valve 17 both are closed, thereby forcing a main turbocharger 7 alone into supercharging operation, and at a high speed range, both of them are opened together, thereby forcing both these turbochargers 7, 8 into the supercharging operation. Here an engine control unit 29 displays a fact that the exhaust selector valve 17 gets out of order at the opened side on a display means 62 in the case where supercharging pressure in a state that only the main turbocharger 7 is in supercharging operation is less than the preimparted map value from relations of throttle opening, engine speed and supercharging pressure. With this constitution, any trouble is detected at the early stage, thus it is alarmable. |
