Zf Friedrichshafen Ag

Michael Sohler

Peter Schiele

Thilo Schmidt

Klaus Steinhauser

Falko Platzer

Bernd Allgaier

Jorg Arnold

Franz Brugger

Magnus Stiefenhofer

Matthias Dietlmeier

Thomas Raab

Tobias Kohr

Bernd Haegele

Tobias Hartmann

Patrick Ledig

A method for operating a motor vehicle with a prime mover (), a drive output (), and a parking lock () is provided. The parking lock (), in an engaged condition, blocks a shaft () coupled to the drive output () and, in a disengaged condition, releases the shaft (). In order to disengage the parking lock (), at least one coupling mass () is coupled to the shaft (), which is coupled to the drive output (), while increasing the moment of inertia effective at the shaft ().

Method and control unit for operating a motor vehicle

A method for operating a motor vehicle with a prime mover (), a transmission (), a driven end (), and a parking lock system () is provided. A shift element () of the transmission () and a parking lock actuator () of the parking lock system () utilize a common pressure control. When the shift element () is actuated with the aid of a pressure control effecting an at least partial engagement of the shift element () and when the pressure control is less than a limiting value for holding the parking lock system () in the disengaged position, the method includes monitoring a parking lock sensor () to determine whether the parking lock sensor () detects a movement of the parking lock actuator () or a signal corresponding to the movement of the parking lock actuator () despite a parking lock detent () having been actuated for locking.

A method for operating a drivetrain of a motor vehicle includes elevating a system pressure acting on a plurality of shift elements (A, B, C, D, E, F) when one of at least one positively locking shift element (A, F) is closed in a force-locking-free state, increasing a torque output by a drive assembly () and then subsequently reducing the torque output by the drive assembly () while the system pressure is elevated by an intervention with the drive assembly (), and reducing the system pressure after reducing the torque output by the drive assembly (). The one of the at least one positively locking shift element (A, F) closed in the force-locking-free state or another one of the at least one positively locking shift element (A, F) is opened while the system pressure is elevated and the torque output by the drive assembly () changes.

Method and control device for operating a transmission

A method is provided for reducing the reaction time of an automatic transmission of a motor vehicle, the vehicle having a hydraulic control unit with a pressure regulator, from an engine stop of an automatic start-stop mechanism. The oil volume that is still present in the hydraulic control unit (HCU) of the transmission prior to the stopping of the internal combustion engine is used for the supply of oil for the actuation of the shifting elements of the transmission upon an engine start.

Method for reducing the reaction time of an automatic transmission of a motor vehicle

A method of operating a drive train having a hybrid drive including a combustion engine and electric motor, a clutch located between the engine and the motor, a transmission, a starting element and a brake pedal. For electric crawling from a state in which the clutch is disengaged, the brake pedal is activated and the combustion engine is turned off, initially the starting element is brought to or maintained at a filling pressure. Next, the rotational speed of the electric motor is adjusted to be higher, by a defined slippage rotational speed, than a transmission side rotational speed. When this slippage is reached, the starting element is further engaged to create a crawl torque at the output. The electric motor continues at rotational speed control so that the slippage is maintained.

Method for operating a drivetrain

A method of monitoring an emergency condition in an automatic transmission, with which, by comparing a theoretical with an actual rotational speed, measured on the transmission input side, overlap of the activated emergency condition, with a gear engagement process called for during the normal condition, is prevented.

Method for checking an emergency condition in a transmission system

A method of operating a vehicle hybrid drive train comprising an internal combustion engine and electric machine whose torque is applicable to a drive output of the drive train. The drive train comprises a clutch arranged between the internal combustion engine and electric machine, an oil pump connected in the drive train downstream of the clutch in relation to the internal combustion engine, and the oil pump can be driven by the internal combustion engine and the electric machine, and a transmission which comprises a shifting elements for producing various gear ratios and which is supplied with hydraulic fluid by the oil pump in an operating-status-dependent manner. The speed of the electric machine is set independently of the speed of the internal combustion engine, in order to supply the transmission with a flow of a volume hydraulic fluid required for the operating point of the transmission present at the time.

Method for operating a vehicle hybrid drive train having an internal combustion engine and having an electric machine

An method for controlling a parallel hybrid drive-train of a vehicle comprising an automatic transmission and a combustion engine which is connected, via a first shifting device, to an electrical machine, which is connected, via a drive shaft, a starting clutch positioned in the transmission. To guarantee safety and high drive comfort of the vehicle during failure of the starting clutch, shifting failures of the starting clutch are monitored. If a shifting failure is recognized, predetermined contingency procedures are initiated and executed in which either continued drive of the vehicle or slowing down of the vehicle to a stop is possible. A device comprises a monitor with a sensor and parts for analyzing and recognizing shifting failures of the starting clutch. Control parts initiate and execute contingency procedures such that a continued drive operation or slowing down of the vehicle to a stop is possible.

Growing community of inventors

Isny, Germany

Michael Sohler