Patent ID: 6951526

Claim:
A power train for a motor vehicle, said power train comprising: a drive unit; a power-shift gearbox with a first gearbox input shaft and a second gearbox input shaft; and a clutch device with a first multi-disk clutch arrangement, which is assigned to the first gearbox input shaft, and a second multi-disk clutch arrangement, which is assigned to the second gearbox input shaft, for transmitting torque between the drive unit an the gearbox; means for supplying an operating fluid to the clutch arrangements for operation under the action of the operating fluid; and an actuator arrangement and a control unit, which controls the actuator arrangement, by means of which gears assigned to the first and the second gearbox input shafts can be engaged and disengaged; wherein the control unit also controls a hydraulic actuating device assigned to the clutch device in order to actuate the clutch arrangements in the engaging and disengaging directions; and wherein the control unit is designed, when in power-shift mode, to use the actuating device to actuate the clutch arrangements in opposite directions when the gearbox is in a state in which a starting gear assigned to the one gearbox input shaft and a target gear assigned to the other gearbox input shaft are engaged in order to transfer the drive torque of the drive unit from the one to the other gearbox input shaft continuously and without interruption in the tractive force and to deactivate the starting gear as a torque-transmitting gear and to activate the target gear as the torque-transmitting gear, and wherein the control unit is designed, when a change is being made from a lower starting gear to a higher target gear, to actuate the clutch arrangement assigned to the target gear in the engaging direction from the disengaged state to such an extent that gearbox input shaft assigned to the target gear, which up to now has been rotating under the action of gearbox drag torques and/or braking torques at a maximum speed which is less than the synchronous speed for the target gear, is accelerated toward the synchronous rpm value and at least approximately reaches it.