| 摘要 |
PURPOSE:To protect an auxiliary turbocharger positively from high temperature even in the case of an intake change-over valve, disposed at a secondary intake port, being out of order in the closed state. CONSTITUTION:An escape valve 81 for allowing the inflow of intake air into a first intake passage 71 from a second intake passage 72 is provided upstream of the throttle valves 4 of the first and second intake passages 71, 72. Accordingly, even in the case of an intake change-over valve 18 being out of order in the closed state, the supercharged air from an auxiliary turbocharger 8 is let escape into the first intake passage 71 connected to a main turbocharger 7 through the escape valve 81 so as to prevent the notable rise of intake air temperature. |
