Internal combustion engine

摘要

An internal combustion engine is disclosed which includes active cylinders being always active and inactive cylinders being inactive when the engine load is below a predetermined value. The engine has an intake passage divided into first and second branches connected to active and inactive cylinders, respectively. The second branch is provided near its inlet with a stop valve and is connected through an EGR valve to the engine exhaust passage and also through an air valve to air source. A sensor is located in the exhaust passage for providing a feedback signal to ensure that the fuel supplied to the engine is maintained at a desired air/fuel ratio. Control means is provided to close the stop valve, open the EGR valve, and cut off the flow of fuel for the inactive cylinders. Means is provided to close the EGR valve, open the air valve, and determined the amount of fuel to the engine regardless of the feedback signal from the sensor under extremely low load conditions.