PURPOSE: To simplify a means for controlling intake air quantity by controlling the pressure of pressurized air to be fed to the actuator of an intake air throttle valve in response to an engine operating condition.
CONSTITUTION: Pressurized air is fed from a pneumatic pump 13 to an actuator 7 for driving an intake air throttle valve 2. A control valve 17 for opening and closing a discharge port 16 is provided in an air passage 14. A control device 19 detects an operating condition such as engine starting, idling, and deceleration, and opens and closes the control valve 17 in response to said detected result for controlling the throttle valve 2. Accordingly, it is not required to provide a throttle valve driving mechanism at each engine operating condition. Thus, the control device can be simplified in its construction.
FURUKAWA MICHITAKE
ABE TETSUO
HARADA SHINICHI
