| 摘要 |
<P>PROBLEM TO BE SOLVED: To control an actual air-fuel ratio to a predetermined air-fuel ratio on the lean side with high accuracy, even when an outboard motor is mounted on a different hull, or its fuel is changed to alcohol-mixed gasoline. <P>SOLUTION: The air-fuel ratio control device includes an open loop controller for controlling the air-fuel ratio to the target air-fuel ratio based on the operating state of an internal combustion engine and a learned value stored in a storage unit, a feedback controller for shifting the target air-fuel ratio to the theoretical air-fuel ratio, and executing the feedback control of the air-fuel ratio to the theoretical air-fuel ratio by using the feedback correction coefficient to be determined based on the output of an O<SB POS="POST">2</SB>sensor in a part of cylinders of the internal combustion engine when a predetermined condition is firstly satisfied after the engine is started while the open loop controller controls the target air-fuel ratio to the predetermined air-fuel ratio on the lean side, and a learned value calculator for calculating the learned value based on the feedback correction coefficient, and rewriting the storage unit. <P>COPYRIGHT: (C)2012,JPO&INPIT |
