| 摘要 |
A reference angle detecting device includes a control shaft (60) that is connected to a controlled object (e.g., to a variable valve actuation mechanism of an engine E) and an electric motor (73) that causes the control shaft (60) to rotate via a worm gear mechanism (72), a stopper (80) disposed on a motion track of a worm wheel (74), an angle sensor (94) that can detect a rotation angle of the control shaft (60), and a controller (90). The stopper (80) includes a spring member (for example, torsion coil spring (84)) which is elastically deformable in an operation direction of the worm wheel (74). The controller (90) drives the electric motor (73) to operate so that the worm wheel (74) may face the stopper (80), and stores the rotation angle at a time point when a change rate É of the rotation angle ¸ detected by the angle sensor (94) changes to a value less than a predetermined threshold É1 as a reference angle ¸ 0 . With this, the reference angle can be detected with high accuracy for control of an angle of the control shaft. |
