| 摘要 |
PROBLEM TO BE SOLVED: To provide an air-fuel radio control apparatus for a general-purpose engine, estimating an air-fuel ratio without providing an air-fuel ratio sensor, estimating an alcohol ratio from the deviation of the air-fuel ratio and injecting the appropriate injection amount of fuel. SOLUTION: In this air-fuel ratio control apparatus for the general-purpose internal combustion engine, a throttle opening is adjusted so that engine speed matches a target rotational speed, the amount of fuel injected is calculated according to fuel injection quantity characteristics predetermined based on the engine speed and throttle opening, and mixed fuel composed of alcohol and gasoline is injected based on the calculated amount of fuel injected. When it is determined that a load connected to the engine is constant, the increased/reduced amount of fuel injected increased or increased/reduced with respect to the calculated amount of fuel injected is injected, an output air-fuel ratio is estimated based on the throttle opening adjusted at that time, and an alcohol rate is estimated from the estimated output air-fuel ratio (S308, S312). The amount of fuel injected is calculated using the fuel injection quantity characteristics in accordance with the alcohol rate(S310, S314). COPYRIGHT: (C)2011,JPO&INPIT |
