| 摘要 |
PROBLEM TO BE SOLVED: To accurately determine whether supplied fuel is heavy fuel at a low temperature.SOLUTION: An internal combustion engine fuel property determination device is applied to an internal combustion engine including an ignition plug and ignition timing control means exerting a feedback control to correct ignition timing that is timing at which a spark is generated from the spark generation unit so that an engine rotational speed converges into a target rotational speed, and comprises a control unit a property of fuel supplied to the internal combustion engine is heavy if an ignition sufficiency rate that is a ratio of an advanced position correction amount of the ignition timing to a maximum ignition correction width that is a maximum width by which the ignition timing can be corrected at a time of correcting the ignition timing by the feedback control is equal to or higher than a predetermined threshold Ch, the control unit setting the threshold Ch to a value in response to an engine temperature representative value having a correlation to a temperature of the internal combustion engine. It is thereby possible to accurately determine whether the fuel supplied to the internal combustion engine is heavy fuel even at a low temperature.SELECTED DRAWING: Figure 2 |
