부산대학교 도서관

In an internal combustion engine to which an air pressure actuation mechanism such as a variable vibration isolating support device is installed side by side, the engine speed at the time of idling is made to suitably converge on the target idling speed. The idling speed control device includes: an idling speed control mechanism for controlling the intake air amount of the internal combustion engine to make the engine speed be the desired target idling speed at the time of idling of the internal combustion engine; an air pressure actuation mechanism operated by selectively introducing the atmospheric pressure and the intake tube negative pressure produced in the intake passage on the down stream side of the throttle valve; and an intake air amount compensating mechanism for compensating the adjusting position of the idling speed control mechanism in the direction of decreasing the intake air amount of the internal combustion engine when introducing the intake tube negative pressure after the introduction of the atmospheric pressure into the air pressure actuation mechanism.