| 主权项 |
1. A connectable four-wheel drive vehicle comprising:
an engine having a drive shaft; a pair of main drive wheels; a main transmission line, which permanently connects the drive shaft to the main drive wheels and comprises a main gearbox and a main differential; a pair of secondary drive wheels, which are normally driven; a connectable secondary transmission line to connect the drive shaft also to the secondary drive wheels and comprising at least one secondary clutch, which, on one side, is connected to the drive shaft upstream of the main gearbox and, on the other side, is connected to the secondary drive wheels; and a control unit; wherein the connectable secondary transmission line comprises a continuously variable transmission, which can be electronically controlled so as to continuously vary its gear ratio between two limit values without ever interrupting the torque transmission; wherein the control unit controls the continuously variable transmission of the connectable secondary transmission line such that, when the vehicle is driving along a bend, the output of each secondary clutch always rotates more slowly than the input of the secondary clutch itself. |
