PURPOSE: To reduce fluctuation of torque, by feeding pressurized air supplied from a supercharger only to cylinders at rest at the time of partial-cylinder operation of an engine having a supercharger and designed to be capable of changing the number of cylinders to be operated.
CONSTITUTION: An intake passage 2 of a multi-cylinder engine having a supercharger 25 is divided into an inoperative-cylinder passage 4 and an operative- cylinder passage 3, and a gate valve 11 is attached to a partition wall for dividing the intake passage 2 into two passages 3 and 4. Further, there are provided a control valve 39 and a switching passage 35 connected to the inoperative-cylinder passage 4 from the intake passage 2 extended from an intake-air compressor 27. When partial-cylinder operation is instructed by a control unit 32, the gate valve 11 is closed and an auxiliary passage 34 and the operative-cylinder pasage 3 are communicated with each other by switching control valves 37 and 39. At the same time, pressurized air supplied from the compressor 27 is carried into the inoperative-cylinder passage 4 via the switching passage 35. Thus, since pressurized air is supplied only to inoperative cylinders AWC, it is enabled to reduce fluctuation of torque at the time of partial-cylinder operation of the engine.
FUJII TAKASHI
KAMEGAYA SHIGERU
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