| 摘要 |
PURPOSE:To raise the stability in car running and secure the safety by putting one of the two control mechanism, a four-wheel steering control mechanism and a front-and-rear-wheel driving force distribution control mechanism, which remains to operate normally into the failsafe side, when the other is in failure. CONSTITUTION:When a car is running normally, detection signals from a steering angle sensor 20, a car speed sensor 23, etc., are fed into a controller 19 to decide the optimum front-and-rear-wheel driving force distributing proportion, which suits best the running conditions and road surface condition, and a front wheel driving clutch 8 is controlled to perform 4WD drive. If judgement at this time is that 4WD is in failure, the driving force distributing proportion shall be corrected so as to raise the front wheel driving force. It it then judged whether sensors and solenoids necessary for 4WD control are in failure, and if yes, the 4WD control shall be interrupted. If no, a solenoid proportional pressure regulator valve 18 is controlled in accordance with the driving force distributing proportion corrected as mentioned above, and the clutch pressure of a clutch 8 is controlled. |
