Patent ID: 7506632

Claim:
An air-intake device for an internal combustion engine, comprising: a throttle valve, disposed in an intake air passage, for controlling an amount of air taken into the internal combustion engine, the throttle valve being hinged to the intake air passage to be pivotally movable around a shaft supporting one end of the throttle valve; an airflow passage, disposed downstream of the throttle valve, for rectifying an airflow therein and for promoting formation of a uniform air-fuel mixture in the internal combustion engine in a predetermined region of an opening-degree of the throttle valve, wherein: an open area of the airflow passage between the throttle valve and a member for forming the airflow passage is changed according to the opening-degree of the throttle valve in the predetermined region of the opening-degree of the throttle valve to thereby control an amount of intake air supplied to the internal combustion engine; and a width (W) of the open area of the airflow passage is narrower than a width of the intake air passage and constant in the predetermined region of the opening-degree of the throttle valve.