| 摘要 |
<p>PURPOSE:To obtain a true intake air flow rate irrespective of generation of a back flow by detecting the flow rate as a mean intake air flow rate at a timing in which a differential value of an output of an airflow meter becomes a maximum. CONSTITUTION:A fuel injection valve 5 of an intake passage 3 injects fuel for a time of a pulse width according to a drive pulse signal from a control unit 6. The unit 6 samples an output (intake air flow rate Q) of a hot wire airflow meter 7, calculates a difference between the value Q this time and a previous value Qold, and obtains a differential value DELTAQ of the output of the meter 7. The value DELTAQ is compared with a maximum differential value nQmax so far, and the DELTAQmax is updated at the time of DELTAQ>DELTAQmax. The value Q is substituted for a value Q0, and a flow rate Q at the time of the maximum differential value is stored. Then, whether it is a predetermined angle for dividing a predetermined crank angle or not is decided, and at the time of the predetermined angle, the value Q0 stored as the flow rate Q at the time of the value DELTAQmax for a predetermined crank angle period is set to mean intake air flow rate QAVE. Thus, detecting accuracy of the intake air flow rate is improved irrespective of influence of generation of a back flow.</p> |
