| 摘要 |
PURPOSE:To detect the intake air amount of engine in full operational region with high accuracy by obtaining the intake air amount by intake pressure and engine revolving number in the region where no exhaust recycling is made and also by a hot-wire flow meter in the region where exhaust recycling is made. CONSTITUTION:The auxiliary air inlet path 10 provided in parallel with the main air inlet path 9 is provided with the hot-wire flow meter 12 to measure the flow rate inside the path 10, the orifice 13 to keep the flow rate ratio of both the paths 9 and 10 constant under all operational conditions, and the intake air temperature compensating resistor 14. And, the pressure converter 19 is connected through the orifice 15, the rubber tube 16, and the damper chamber 17 to the upstream side of the fuel injection valve 5 of the main air inlet path 9. Exhaust recycling rate is calculated by the microcomputer 7 on the basis of intake pressure by the pressure converter 19, the temperature of cooling water, and the revolving number of engine, and when the exhaust recycling rate is zero, the intake air amount is obtained from the pressure of intake pipe and the revolving number of engine, whereas when exhaust recycling is made, it is obtained from the output of the hot-wire flow meter 12. |
