Measuring and testing – Volume or rate of flow – By measuring vibrations or acoustic energy
Patent
1987-04-15
1989-03-28
Levy, Stewart J.
Measuring and testing
Volume or rate of flow
By measuring vibrations or acoustic energy
7386123, G01F 132
Patent
active
048153249
ABSTRACT:
An intake air meter for measuring the intake air of an internal combustion engine operates on the principle of an ultrasonic Karman vortex flowmeter. A Karman vortex shedder is disposed in the main intake air passageway of an engine. Ultrasonic waves which are generated by an ultrasonic transmitter are phase modulated by the Karman vortex street which is shed by the vortex shedder. An ultrasonic receiver receives the ultrasonic waves and produces a phase modulated output signal, which is demodulated using a phase locked loop and a low-pass filter. The output of the low-pass filter can be used to count the rate of which Karman vortices are generated by the vortex shedder. A pressure-dependent component in the output signal from the low-pass filter which is caused by pressure variations within the main intake air passageway is removed by compensating means comprising a pressure sensor which measures the air pressure in the vicinity of the vortex shedder, an amplifier which amplifies the AC component of the output of the pressure sensor to equal the amplitude of the pressure-dependent component, an inverter which inverts the amplified output, and a waveform shaper which sums the inverted output and the output from the low-pass filter.
REFERENCES:
patent: 3818877 (1974-06-01), Barrera et al.
patent: 3965730 (1976-06-01), Innes
patent: 4452089 (1984-05-01), Wada
patent: 4555937 (1985-12-01), Sumal
Joy, Robert D., "Airflow Measurement for Engine Control", Feb. 23, 1976, p. 5.
Abe Minoru
Tada Yasuo
Bell Robert P.
Levy Stewart J.
Mitsubishi Denki & Kabushiki Kaisha
LandOfFree
Intake air meter for an internal combustion engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Intake air meter for an internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intake air meter for an internal combustion engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1651136