| 摘要 |
PURPOSE:To prevent occurrence of troubles on turbo-chargers by enabling early determination of the troubles on both intake and exhaust change-over valves on the basis of the detected results of supercharge pressures before and after the changeover from the operation of a main supercharger alone to the operation of both main auxiliary superchargers. CONSTITUTION:In an engine wherein, in the low air intake quantity region, both an intake changeover valve 18 and an exhaust changeover valve 17 are closed so that a main turbocharger 7 alone is operated in supercharging and in the high air intake region both main auxiliary changeover valves 17, 18 are opened so that both auxiliary turbochargers 7, 8 are operated in supercharging, an ECU 29 in which are inputted the outputs of a supercharge pressure sensor 30, a throttle opening degree sensor 5, etc., is provided. Following changeover from the supercharging operation of the main turbocharger 7 alone to the supercharging operation of both turbochargers 7, 8, when the pressure value obtained by subtracting a minimum supercharge pressure value after the changeover from the maximum supercharge pressure value sensed by a supercharging pressure sensor 30 is smaller than a specified pressure value, presence of troubles in the intake changeover valve 18 and the exhaust changeover valve 17 is determined and this information is indicated on a display means 62. |
