| 摘要 |
PURPOSE:To improve output performance upon decreased operating cylinders operation and reduce shock upon switching to the decreased operating cylinders operation by a method wherein rich oxygen air, amplified by an oxygen concentration amplifying device, is supplied to the cylinders being supplied with fuel upon the decreased operating cylinders operation. CONSTITUTION:Under full cylinders operation, a shutter valve 8, interposed in a branched path 2a of first cylinder group 1A side, is fully opened. Under the decreaed operating cylinders operation, the igniting operation of the first cylinders group 1A is stopped. When the operation of the engine is brought into light load operating condition while running under the full cylinders operation, a control unit 26 decides, from the outputs of a vacuum sensors 27 and a temperature sensor 28, that the operating condition is in the area of decreased operating cylinders operation. Then, the actuator 22 of an oxygen concentration regulating unit 18 is energized and closes a control valve 19 and a relief valve 25 while opens the control valve 20. According to these operations, the rich oxygen air, amplified by the oxygen concentration amplifying device 13, is supplied to the engine. On the other hand, the actuator 9 is energized with a predetermined time delay and the shutter valve 8 is closed, whereby the operation, effected by the second cylinder group 1B only, may be effected. |
