| 摘要 |
PURPOSE:To control fuel stably and accurately by changing over the drive frequency of a solenoid valve for controlling fuel when decelerating an internal- combustion engine in a method of controlling the air-fuel ratio of the engine. CONSTITUTION:The quantity of fuel supplied to an engine is arithmetically operated by an air-fuel ratio arithmetic means 1 by the quantity of air QA sucked into the engine and ignition pulses Ig as revolution-number signals, and transmitted to a drive means 3 as pulse width signals T. The air-fuel ratio arithmetic means 1 decides the presence of the deceleration of the engine, and transmits a frequency dividing ratio such as m=3 to a frequency-division ratio changeover means 2 when decelerating the engine and the ratio such as m=1 to the means 2 when the engine is not decelerated. The frequency-division ratio changeover means 2 divides the frequency F1 of ignition pulses Ig by the frequency dividing ratio (m). Consequently, F reaches the frequency of F1/3 when decelerating the engine and F1 when the engine is not decelerated. Accordingly, the desirable quantity of fuel to be reduced can be realized stably and accurately when decelerating the engine. |
