Intake air quantity control method for internal combustion engines

摘要

A method for controlling the flow rate of supplementary air supplied to an internal combustion engine via at least one supplementary air passage bypassing a throttle valve arranged in the intake air passage, by means of at least one control valve arranged across the at lease one supplementary air passage. The valve opening of the control valve is decreased with a decrease in the engine rotational speed, when the throttle valve is detected to be in a substantially fully closed position and at the same time the engine rotational speed is higher than a predetermined value which is higher than an idling speed of the engine. Preferably, the at least one supplementary air passage comprises a plurality of air passages, and the at least one control valve comprises a plurality of on-off valves arranged across respective ones of the air passages. One or more of the on-off valves are selectively opened in response to the extent of engine warming-up and/or an increase in engine load.