| 摘要 |
PURPOSE:To enhance the control accuracy of a engine control device in which the data of intake-air flow rates are detected in accordance with the frequency of generation of Karman vortices, by correcting the above-mentioned data of intake-air flow rate in accordance with the pressure condition of intake-air to correct errors in the data of intake-air flow rates caused by pulsations of intake-air. CONSTITUTION:An intake-air pressure sensor 26 for detecting the pressure condition of intake-air in an intake-air passage 22 in an engine 21, is attached to a Karman vortex type air flow meter 24 which is disposed in the air-inlet port of the intake passage 22 and integrally incorporated with an air-cleaner 23. The above-mentioned flow meter 24 utilizes, as the data of intake-air flow rates, deviations obtained by a phase comparing circuit 9 for comparing a reference signal from an averaged phase follow-up circuit 8 with the output signal from a receiver 6 which receives ultrasonic waves transmitted from an ultrasonic wave transmitter 5 that is applied with a pulse signal from a signal generating circuit 7. Then, a computing circuit 51 subtracts output signals obtained from the intake-air pressure sensor 26 through an amplifier 50 are subtracted from the data of intake-air flow-rates to remove pulsation components due to the pulsation of intake-air, from the data of the intake-air flow rates.
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