| 摘要 |
PURPOSE:To simplify a control circuit by turning on and off pilot injection in synchronization with the operation of an exhaust change-over valve wherein the operation regions of small and large turbo charges are changed over by opening and closing the exhaust change-over valve. CONSTITUTION:A series two-stage supercharging Diesel engine has large and small turbo chargers A, B disposed in series in the direction of gas flow. An exhaust change-over valve D is provided in an exhaust bypass path C bypassing the small turbo charger so that the operation regions of the small and large turbo chargers B, A are changed over by opening and closing the exhausted change-over valve D. Then, a fuel injector E is is constituted to perform pilot injection and provided with a pilot injection controlling means F for selectively performing the pilot injection according to the opening and closing operations of the exhaust change-over valve D. The pilot injection is controlled to be performed in closing the exhaust change-over valve D and stopped in opening the same. |
