| 摘要 |
<p>PURPOSE:To measure the average flow rate of pulsating air flow containing reverse flow by accumulating the air flow rate between the intake strokes and subtracting two times of a reverse air flow rate, determined by a response delay means and an air flow direction detecting means, from the accumulated air flow. CONSTITUTION:An air flow rate signal from a flow rate detecting section in a hot wire air flowmeter 1 is fed to an engine control circuit 3 along with a reverse air flow rate signal from an air flow direction detecting means 2(flow rate detecting section and air temperature detecting section have that function). The circuit 3 accumulates the air flow rate between intake strokes determined by the flowmeter 1 and two times of a reverse air flow rate (practically, an appropriate value between one and two times of reverse air flow rate) determined by a response lag correcting means and the flow direction detecting means, is subtracted from the accumulated air flow thus obtaining the average flow rate of pulsating air flow containing a reverse flow. The reverse air flow rate is an approximate value determined by corrective calculation and accompanied with an error, but since it is significantly lower than the forward air flow rate in the intake air flow, the error has insignificant effect on the average air flow rate and an accurate average air flow rate can be obtained.</p> |
