Patent ID: 6834639
Filing Date: 2004-12-28
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 produces 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 first 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; a first spring winding disposed so as to exert a first spring pressure on said opener member in a first rotational direction in which said throttle valve is rotated from the fully opened position to the middle position, when said actuator produces no output, said first spring winding being urged at an end thereof into constant engagement with said first stopper to hold said opener member from rotating in a second rotational direction in which said throttle valve is rotated from the fully closed position to the middle position; and a second spring winding having a first and a second end between which said opener member extends, when said actuator produces no output, the first end abutting against a second stopper, the second end abutting against said opener member so as to exert a second spring pressure on said opener member in the second rotational direction to nip said opener member between the second end of said second spring winding and the end of said first spring winding elastically through the first and second spring pressures, thereby holding said throttle valve at the middle position.