| 摘要 |
PROBLEM TO BE SOLVED: To provide an engine capable of restraining hunting of engine rotation. SOLUTION: In this engine, supercharging is performed in an intake passage 3 by a supercharger 30 driven by exhaust energy, and the intake passage 3 is linked with a valve working pressure chamber 34 of a valve actuator 8 via a supercharging pressure transmission passage 20 by using the pneumatic type valve actuator 8 for driving an EGR valve 9. The valve working pressure of the valve working pressure chamber 34 of the valve actuator 8 is increased as supercharging pressure in the intake passage 3 increases. When the valve working pressure of the valve working pressure chamber 34 becomes less than a predetermined value, a valve closing state of the EGR valve 9 is maintained by a valve closing energizing means 9b, and when the valve working pressure of the valve working pressure chamber 34 becomes the predetermined valve or more, the EGR valve 9 is opened by the valve working pressure of the valve working pressure chamber 34. A check valve 24 for allowing a backflow of a predetermined flow rate is arranged in the middle of the supercharging pressure transmission passage 20 so that this check valve 24 becomes passing resistance of the backflow of a transmission medium from the valve working pressure chamber 34 side. COPYRIGHT: (C)2009,JPO&INPIT
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