Patent ID: 6881171
Filing Date: 2005-04-19
Classification: B60K,B60L,B60W,B60Y,F16D,F16H,Y02T,Y10S,Y10T

Abstract:
1. Method for operating a drive train belonging to a motor vehicle, the drive train being provided with: torque-generating device comprising at least one drive unit; a gearbox comprising a synchronizing device, at least one gearbox output shaft, a first gearbox input shaft assigned at least to a first gear, and a second gearbox input shaft assigned at least to a second gear; a multi-clutch device installed between the drive unit and the gearbox to transmit torque between the drive unit and the gearbox, said multi-clutch device comprising a first clutch arrangement assigned to the first gearbox input shaft and a second clutch arrangement assigned to the second gearbox input shaft wherein said clutch arrangements can be actuated independently of each other, said method comprising, during a shifting sequence in at least one of a pull-mode operating state and a push-mode operating state of the drive train, shifting between said first gear and said second gear by actuating the clutch arrangements and controlling the torque-generating device so that at least one of the following criteria is fulfilled: (a) during a transition phase in the shifting sequence, a monotonically changing torque is present at the gearbox output shaft, where the difference between the torque at the beginning of the transition phase and the torque at the end of the transition phase corresponds essentially to the change in the gear ratio of the gearbox which occurs during the shifting method; (b) during the shifting sequence, the torque present at the gearbox output shaft remains essentially the same before and after the transition phase; (c) during the shifting sequence, a gearbox input torque, which remains essentially constant and which corresponds for a certain period of time to the sum of a first torque contribution introduced via the first gearbox input shaft and a second torque contribution introduced via the second gearbox input shaft, is introduced into the gearbox via the gearbox input shafts; and (d) during the shifting sequence, it is achieved that the vehicle accelerates in one of an essentially monotonically rising and an essentially monotonically falling manner.