| 摘要 |
<p>PURPOSE:To improve disconnecting reliability of a driving force transmission system using a clutch and to improve safety when abnormality occurs by interposing two clutches in a series in the driving force transmission system between an electric motor and a rear wheel steering member. CONSTITUTION:A clutch 48 is controlled by a control unit, so that when a designated abnormality occurs, a driving force transmission system between a servo motor 32 and a rear wheel steering shaft 30 is disconnected to let the rear wheel steering shaft 30 be free, whereby the steering shaft 30 is returned to the neutral position by centering spring means 36 to be put in the two-wheel state, thereby accomplishing fail-safe. The clutch 48 is a twin-electromagnetic clutch where two clutches are disposed in a series. An upper clutch 48A is of a normal-open type and a low clutch 48B is of a normal-close type.</p> |
