| 摘要 |
A fail-safe mechanism of an air induction control apparatus for automotive engines is provided which is designed to hold a throttle valve at a middle position when a valve actuator has failed to move the throttle valve. The fail-safe mechanism includes a middle position hold stopper, an opener lever connected to the throttle shaft, and a first and a second coil spring. The first coil spring works to exert a first spring pressure on the opener member in a first rotational direction in which the throttle valve is rotated from a fully opened position to the middle position. The first coil spring is urged at an end thereof into constant engagement with the middle position hold stopper to hold the opener member from rotating in a second rotational direction opposite the first rotational direction. The second coil spring has a first and a second end between which the opener member extends. The first end abuts against the middle position hold stopper. The second end abuts against the opener member so as to exert a second spring pressure on the opener member in the second rotational direction to nip the opener member between the second end of the second coil spring and the end of the first coil spring elastically through the first and second spring pressures, thereby holding the throttle valve at the middle position.
|
