Patent ID: 6448762
Filing Date: 2002-09-10
Classification: F02D,G01D

Abstract:
A rotation-angle-detection device for detecting an open angle of a throttle valve of an air intake system at an idling operation of an engine comprising:a throttle body having a throttle valve and an opening end on which a motor and a speed reduction unit are mounted; an elongated resinous cover for covering said opening end and said motor and speed reduction unit, said cover having a longitudinal axis; a magnetic cylindrical rotor core linked to said throttle valve; a magnetic stator core having a magnetic detection gap extending through a center of said stator core in parallel with said longitudinal axis of said cover, said stator core being disposed inside said rotor core to be coaxial therewith and molded into said resinous cover, a permanent magnet fixed to said cylindrical rotor core to be rotatable in response to opening operation of said throttle valve; a magnetic sensor having a detection direction, said magnetic sensor being fixed to said resinous cover and disposed in said magnetic detection gap so that said detection direction and said longitudinal axis of said cover cross each other at a right angle, wherein said permanent magnet is disposed so that said output signal of said magnetic sensor becomes zero when said throttle valve is positioned at said idling operation.