Abstract: In a 4WD vehicle that is basically an FF type, a propeller shaft 4 includes, on a front end and a rear end thereof, respective driving force transmission devices 3 and 5. The propeller shaft 4 includes an electric motor 41, and when the electric motor 41 is rotated in a backward direction of the vehicle during a 2WD state, a hypoid ring gear 36 of a transfer mechanism 32 of the driving force transmission device 3 is moved so as to engage a clutch mechanism 31. By such an engagement, engine torque is transmitted to the driving force transmission device 5 via the propeller shaft 4. Thus, a hypoid ring gear 56 of a transfer mechanism 52 of the driving force transmission device 5 is moved so as to engage a clutch mechanism 51. Accordingly, a drive state is switched to a 4WD state.

Abstract: In a 4WD vehicle that is basically an FF type, a propeller shaft 4 includes, on a front end and a rear end thereof, respective driving force transmission devices 3 and 5. The propeller shaft 4 includes an electric motor 41, and when the electric motor 41 is rotated in a backward direction of the vehicle during a 2WD state, a hypoid ring gear 36 of a transfer mechanism 32 of the driving force transmission device 3 is moved so as to engage a clutch mechanism 31. By such an engagement, engine torque is transmitted to the driving force transmission device 5 via the propeller shaft 4. Thus, a hypoid ring gear 56 of a transfer mechanism 52 of the driving force transmission device 5 is moved so as to engage a clutch mechanism 51. Accordingly, a drive state is switched to a 4WD state.

Abstract: A driving force distribution device for distributing driving force from an engine to left and right rear wheels has: a differential case which accommodates a differential mechanism therein; an intermediate shaft which is provided parallel to an output shaft extending leftward or rightward from the differential mechanism; a speed-up mechanism which is provided to the left or right of the differential case and changes and transmits driving force input to the differential case to the output shaft via the intermediate shaft; and a clutch mechanism capable of switching between a transmitting state in which the speed-up mechanism transmits the driving force to the output shaft and a blocking state in which the transmission of the driving force is blocked. According to the driving force distribution device, cost reduction and downsizing of the driving force distribution mechanism and a housing thereof can be realized.

Abstract: A driving force distribution device for distributing driving force from an engine to left and right rear wheels has: a differential case which accommodates a differential mechanism therein; an intermediate shaft which is provided parallel to an output shaft extending leftward or rightward from the differential mechanism; a speed-up mechanism which is provided to the left or right of the differential case and changes and transmits driving force input to the differential case to the output shaft via the intermediate shaft; and a clutch mechanism capable of switching between a transmitting state in which the speed-up mechanism transmits the driving force to the output shaft and a blocking state in which the transmission of the driving force is blocked. According to the driving force distribution device, cost reduction and downsizing of the driving force distribution mechanism and a housing thereof can be realized.

Abstract: A drive force control apparatus for a vehicle, having at least one engaging element and configured to implement drive force control to control transmitting of a drive force generated by a drive power source, to left and right drive wheels by controlling an engaged state of the at least one engaging element in accordance with a demand for control of the drive force, includes control demand determining means determining possibility that the demand for control of the drive force is made on the basis of a predetermined standard, and engagement control means implementing preliminary control to control the engaged state of the at least one engaging element to a stage prior to implementing of the drive force control if the control demand determining means determines that it is possible that the demand for control would be made.