Intake air control apparatus for an engine

摘要

An air control apparatus for an engine can relax the tolerance of positional accuracy in the mounting of a rotational angle detection sensor. The intake air control apparatus includes: a shaft ( 6 ); a throttle valve ( 7 ) fixedly secured to the shaft ( 6 ) for adjusting the degree of opening in an intake passage through a rotational angle thereof; a permanent magnet ( 12 ) provided on an end portion of the shaft ( 6 ) with its N pole and S pole being positioned in a diametral direction thereof; and a rotational angle detection sensor ( 14 ) having a magnetoresistive element disposed in a spaced parallel relation with respect to the permanent magnet ( 12 ) for detecting a change in the azimuth of magnetic flux of the permanent magnet ( 12 ) thereby to sense a rotational angle of the throttle valve ( 7 ).