To avoid the destabilization of vehicle behavior by simultaneous locking of four wheels while utilizing an advantage of a four-wheel drive vehicle on braking to the maximum.
A control device of the four-wheel drive vehicle includes a transfer clutch CT, by which part of the driving forces of rear wheels WRL, WRR can be distributed to front wheels WFL, WFR. In this device, the engagement of the transfer clutch CT is released for only a predetermined period of time when a friction coefficient of a road surface is determined to be low and a driver's braking operation is detected. Thus, the transfer clutch CT prevents the four wheels mutually connected from falling into a locked state simultaneously and the stability of vehicle behavior can be secured by enabling a side slip prevention device (ABS device) to be operated by wheel speed differences generated in the four wheels before the vehicle behavior in the lateral direction is disturbed. Moreover, since the time of releasing the engagement of the transfer clutch CT can be suppressed to the necessary minimum, the advantage of the four-wheel drive vehicle that vehicle stability increases on braking can be utilized to the maximum.
| JPS6243322A | 1987-02-25 | |||
| JPH01249554A | 1989-10-04 |
Kazuaki Niki
Nude Shima Shinji