Patent ID: 6640776
Filing Date: 2003-11-04
Classification: F02D

Abstract:
An air induction control apparatus for an internal combustion engine comprising:a throttle valve supported by a throttle shaft rotatably within an intake air passage to control the quantity of intake air flowing through the intake air passage; an actuator working to produce an output which rotates the throttle shaft for opening and closing said throttle valve selectively between a fully closed portion and a fully opened position; a middle position hold stopper defining a middle position at which said throttle valve is held between the fully opened and closed positions when said actuator outputs no torque; an opener member connected to the throttle shaft to be rotatable together with the throttle shaft; and a spring made up of a first and a second winding and a third spring portion formed by a connection of the first and second windings, an end of the first winding opposite the third spring portion engaging a stopper formed on a throttle body so as to produce a first spring pressure which urges the third spring portion in a first rotational direction in which said throttle valve is rotated from the fully opened position to the middle position, an end of the second winding opposite the third spring portion engaging said opener member so as to produce a second spring pressure which urges said opener member in a second rotational direction in which said throttle valve is rotated from the fully closed position to the middle position, when said actuator produces no output, said third spring portion being held in engagement with said middle position hold stopper to nip said opener member between the third spring portion and the end of the second winding elastically through the first and second spring pressures, thereby holding said throttle valve at the middle position.