PURPOSE: To keep off any hunting in and around a control valve selecting point due to flow characteristic variations within the tolerance of each control valve by installing an opening clamp means which clamps the opening of a control valve according to specified conditions of a total duty and resumes the opening control of the control valve.
CONSTITUTION: Plural bypass air passages 6 are set up parallelly in an intake pipe of an internal combustion engine as bypassing a throttle valve, and each control valve 5 is installed in these passages. In addition, on the basis of engine speed of an engine speed detecting means 1, each total duty of these control valves 5 is set by a duty setting means 2. Moreover, it is controlled by a duty distributing means 4 so as to secure the total duty of each control valve 5. In the above device, when the total duty has come within the specified range before and after the value to select an on-off control valve to full-close or specified duty opening, the opening of all control valves 5 is clamped, and when the engine speed produced a deviation of more than the specified value to the setting engine speed, there is provided an opening clamp means 3 which resumes the opening control of each control valve 5.
OBA HIDEHIRO
MEGURO TAIICHI
