Intake air control apparatus for an engine

Abstract

An intake air control apparatus for an engine is capable of suppressing the influence of external magnetic flux from outside thereby to prevent a variation in an output of a rotational angle detection sensor due to the external magnetic flux. A permanent magnet is provided on an end portion of a shaft. A rotational angle detection sensor is disposed in a spaced parallel relation with respect to the permanent magnet, and has a magnetoresistive element for detecting a change in direction of a magnetic flux of the permanent magnet thereby to detect a rotational angle of a throttle valve. A bypass member is disposed to enclose the rotational angle detection sensor with its side near the permanent magnet apertured to form an opening surface, the bypass member being made of a magnetic material which is adapted to form a bypass path for the magnetic flux from the permanent magnet.

Dependencies are inferred from the claim text.