Intake air flow rate detector
AssigneeNissan Motor Co., Ltd.
InventorToru Kita
Life of this patent
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Abstract
An intake air flow rate detector of an internal engine using a Karman vortex sensor, wherein the mass flow rate is obtained by detecting a volumetric flow rate by the Karman vortex sensor and a dynamic pressure or differential pressure at upstream and downstream of the sensor by a strain gage mounted on a partition in a closed chamber. Density compensation of the flow of air is effected only taking said measurement values at a standard range in which the Karman vortex is stable and the differential pressure has a large value.
Claims3
An intake air flow rate detector of an internal engine using a Karman vortex sensor provided in an intake system of the engine for measuring the amount of the intake air comprising:
- first means for delivering a first signal each time an output of the Karman vortex sensor assumes a predetermined period or is within a predetermined frequency range,
- second means for detecting a dynamic pressure of the intake air or a differential pressure between two points in said intake system;
- third means for sampling and holding an output of said second means at each time of delivery of the first signal, and
- fourth means responsive to outputs of said Karman vortex sensor and said third means for delivering an output signal which has a value corresponding to the output of the Karman vortex sensor after density compensation.
Dependencies are inferred from the claim text.