| 摘要 |
PURPOSE:To improve fuel consumption at the time of a light-load operation by making mixture leaner by a certain amount without having feed back in the light-load operation in the case of feed back control accompanied by an O2 sensor. CONSTITUTION:A solenoid valve 15 for carburetor air bleed control is activated by the feed back control of the O2 sensor 11 and a control circuit 12. At the time of a light-load operation, a switching control circuit 18 outputs signal (a) for a certain time of a timer 29 by the signal from a load detector 13 to turn the SW20 on, then, an average position operation circuit operates an average value of valve operation and keep the value in ''hold'' 27. The circuit 18 outputs signal (b) after a certain time, and, while comparing a value (IV) from a valve operating position operation circuit 25 with a value (VII) kept in ''hold'' 27 plus a certain value, a signal for opening a valve is output until the value (IV) of the circuit 25 coincides with the value (VII). At this time, the SW21 and SW22 are changed over to each other so as to avoid the feed back control for executing the specified leaning control of the mixture. |
