| 摘要 |
<p>PURPOSE:To reduce the supercharging pressure by maintaining a valve of an idle speed control device at a fully-opened state while the operational state of engine is within a supercharging region and the exhaust temperature is over a fixed high-temperature level. CONSTITUTION:When an exhaust temperature is below about 850 deg.C on the basis of an exhaust temperature signal taken in from an exhaust temperature sensor 19, an idle speed control device 18 is perfectly closed. Since a bypass air flow to an upper stream side passage 11 of a turbo-charger from a surge tank 9 is reduced to or maintained at zero, the compressed air pressurized by the turbo- charger 14 is supplied to an engine main body 1 without being reduced. When the exhaust temperature is over about 850 deg.C, the idle speed control device 18 is fully opened. The compressed air pressurized by the turbo-charger 14 is supplied to the engine main body 1 reduced in pressure.</p> |
