| 摘要 |
<p>PROBLEM TO BE SOLVED: To surely prevent generation of an abnormal stick of a variable nozzle by providing a forcible opening/closing means to forcibly open/close the variable nozzle provided inside an exhaust gas turbine of a turbocharger when an internal combustion engine is in the specified running condition. SOLUTION: A plurality of variable nozzles 60 to variably adjust the effective area of an internal flow passage are provided on an exhaust gas turbine 50 of a turbocharger 44, and these variable nozzles 60 are drive-controlled by a negative actuator 62 through a negative pressure regulating valve 64 to be controlled by an ECU 12. To prevent any abnormal stick of these variable nozzles 60, when the ECU 12 judges that a vehicle is stopped, and an internal combustion engine 10 is in an idling condition, the variable nozzles are controlled to forcibly drive the variable nozzles 60 over the whole range between the totally-closed position and the totally-opened position. Carbon is prevented from being deposited in the vicinity of the variable nozzles 60, and any abnormal stick is prevented in advance.</p> |
