Patent ID: 7178388

Claim:
An intake air flow detecting device for an internal combustion engine, the detecting device being provided to an intake air passage, through which intake air flows into the internal combustion engine, intake air, which flows through the intake air passage, being divided into intake air flowing through a main passage and intake air flowing through a bypass passage, the detecting device comprising: a thermal type air flowmeter that includes a detector arranged in the bypass passage, the detector detecting an air flow amount in the intake air passage; a bypass flow delay information calculating means that calculates a bypass flow delay information, the bypass flow delay information being an information of delay in variation in a bypass flow amount with respect to variation in a main flow amount, the bypass flow amount being an air flow amount in the bypass passage, the main flow amount being an air flow amount in the main passage; a response delay compensating means that compensates delay in response of the air flowmeter in accordance with the bypass flow delay information; a first means that calculates air flow velocity in the main passage in accordance with the main flow amount, the air flow velocity calculated using the first means being a main flow velocity; and a second means that calculates air flow velocity in the bypass passage in accordance with the main flow velocity, a loss factor of the main passage, and a loss factor of the bypass passage, the air flow velocity calculated using the second means being a bypass flow velocity, wherein the bypass flow delay information calculating means that calculates the bypass flow delay information in accordance with the bypass flow velocity.