Air-flow meter for internal combustion engine

摘要

An air-flow meter wherein a bypass air passage for bypassing a main air passage is provided in a throttle chamber of an internal combustion engine, and a hot wire is arranged within the bypass air passage, with the amount of air flow being measured on the basis of a change in the resistance of the hot wire. A portion for diverting the direction of air streams is disposed in an upstream part of the bypass air passage so as to assign a dust removing function, and a diameter of the hot wire is selected so that dust particles flowing to the vicinity of the hot wire do not adhere to the hot wire. A surface of the hot wire is coated with glass, and a temperature of the surface of the hot wire is maintained at or above about 100 DEG C. to enhance the prevention of dust particles adhering to the hot wire.