Method for controlling a separating clutch in a hybrid drive train, and drive train

摘要

A hybrid drivetrain and method for controlling a friction clutch of a hybrid drivetrain of a motor vehicle having a combustion engine which is coupled by means of a freewheel to a transmission input shaft of a transmission to transmit the engine torque, and having an electric machine which starts the combustion engine and/or propels the motor vehicle, which friction clutch transmits to the combustion engine a summed torque formed of a starting torque for starting the combustion engine by means of the electric machine and a drag torque which acts on the combustion engine when the drivetrain is in drag mode. To be able to operate the friction clutch reliably and to avoid over-dimensioning of the friction clutch as a result of high summed torques, a torque present at the friction clutch is limited to a predefined transmission torque which can be transmitted via the friction clutch.

主权项

1. A method for controlling a friction clutch of a hybrid drivetrain of a motor vehicle having a combustion engine, which is coupled by means of a freewheel to a transmission input shaft of a transmission to transmit engine torque, the method comprising the following steps:
transmitting drag torque from the input shaft to the friction clutch; transmitting starting torque from an electric machine to the friction clutch; transmitting, via the friction clutch, a summed torque, formed of the starting torque and the drag torque, to the combustion engine for starting the combustion engine by means of the electric machine; and, slipping the friction clutch to limit the summed torque present at the friction clutch to a predefined transmission torque which can be transmitted via the friction clutch.