CONTROL DEVICE FOR FOUR WHEEL DRIVE VEHICLE

摘要

A control device for a four wheel drive vehicle. Differential limitation is applied to both of right and left rear wheels, with 2WD_d state being maintained, by executing two wheel control for engaging or half-engaging a first clutch and a second clutch. As the two wheel drive control is executed, a moment that suppresses the rotation speed difference between the right and left rear wheels acts on the right and left rear wheels even in the 2WD_d state. When the rotation speed difference occurs between the right and left rear wheels, a braking force is allowed to act on the vehicle wheel on the high rotation side and a driving force is allowed to act on the vehicle wheel on the low rotation side through the execution of the two wheel drive control so that a stable moment acts on the vehicle without a transition to a 4WD state.

主权项

1. A control device for a four wheel drive vehicle, the four wheel drive vehicle including;
a disconnection mechanism configured to connect/disconnect a power transmission path transmitting a part of power of a driving force source transmitted to main driving wheels to auxiliary driving wheels during four wheel drive of the four wheel drive vehicle; a first clutch disposed in one of power transmission paths between the disconnection mechanism and both of right and left wheels of the auxiliary driving wheels; and a second clutch disposed in the other one of the power transmission paths between the disconnection mechanism and both of the right and left wheels of the auxiliary driving wheels, the control device comprising: an electronic control unit configured to: (a) switch an operation state of the disconnection mechanism, the first clutch, and the second clutch in accordance with a traveling state of the four wheel drive vehicle, and (b) execute a two wheel drive control for engaging or half-engaging the first clutch and the second clutch, based on the traveling state of the four wheel drive vehicle, with a two wheel drive state where the disconnection mechanism are released being maintained.