Zf Friedrichshafen Ag

Other

Bernd Allgaier

Peter Schiele

Friedrich Tenbrock

Michael Gromus

Christian Popp

Thilo Schmidt

Klaus Steinhauser

Christian Schwemer

Johannes Kaltenbach

Thomas Lemp

Ralf Dreibholz

Georg Gierer

Stefan Blattner

Gerd Frotscher

Tobias Zollner

Stefan Kilian

Markus Herrmann

Franz-Josef Schuler

Markus Henneken

Michael Sohler

Holger Bacher

Peter Spoerl

Heinrich Zeller

Clemens Kuhn

Patrick Peter

Lorenz Fehrenbach

Martin Neumann

Klaus Habe

Ruben Cüppers

When the stop valve is in a first shifting position, a torque-transferring shift element is sealed tight against the rest of a hydraulic system by a stop valve, such that the actuating pressure enclosed in the shift element remains essentially constant or does not decrease. The stop valve is formed and arranged in the hydraulic system such that the stop valve is held in the first shifting position by the force of a barrier pressure generated by the pump, and, upon a standstill of the pump or falling below a certain value of the pressure generated by the pump, the stop valve is automatically displaceable at least through the action of the trapped shift element pressure into a second shifting position, in which the respective shift element is connected to the rest of the hydraulic system and the shift element is open.

Hydraulic control device for an automatic transmission

A method for operating an automatic transmission of a motor vehicle, whereas the automatic transmission features several interlockable shifting elements, involves determining, from the data made available from the driving operation of the motor vehicle, a change to consumption of the motor vehicle expected to be caused by an activated interlocking of the shifting elements and a change to the shifting dynamics of the motor vehicle expected to be caused by an activated interlocking of the shifting elements. The changes are evaluated such that, depending on the change to consumption and depending on the change to shifting dynamics, an interlocking of the shifting elements is permitted or not permitted.

Method and control device thereto for operating an automatic transmission

A method of operating a drive-train of a hybrid vehicle which comprises at least a hybrid drive with an internal combustion engine and an electric machine, an automatic or automated change-speed transmission connected between the hybrid drive and a drive output, and a clutch connected between the internal combustion engine and the electric machine. When starting the internal combustion engine from a purely electric driving mode, the clutch is initially disengaged. To start the internal combustion engine, the clutch is at least partially engaged and the internal combustion engine is drag-started by the electric machine, and, in parallel with starting the internal combustion engine, a downshift in the transmission is initiated once a rotational speed of the internal combustion engine reaches or exceeds an applicable threshold value.

Method and control unit for operating a drive train of a hybrid vehicle

A method for operating a hybrid vehicle comprises conducting unfire operation in an internal-combustion engine in a fuel cut-off mode during a hybrid-mode ride in deceleration of the internal-combustion engine, disconnecting the internal-combustion engine from an output while maintaining the fuel cut-off mode, and reducing a transmission capacity of a clutch configured to couple the internal-combustion engine and an electric motor. During a hybrid-mode ride in deceleration of the internal-combustion engine for transition to the purely electric drive, the internal-combustion engine may be disconnected from the output and shut down. When the internal-combustion engine is operated unfired in a fuel cut-off mode, the internal-combustion engine may be disconnected from the output and shut down by reducing the transmission capacity of the clutch that is connected between the internal-combustion engine and the electric motor.

Method and system for operating a hybrid vehicle

A method of operating a drive train of a motor vehicle in which the drive train comprises at least a hybrid drive with an internal combustion engine and an electric motor, a clutch connected between the combustion engine and the electric motor, a transmission arranged between the hybrid drive and a drive output, and preferably a transmission-internal or -external starting element. When the combustion engine is entrained into motion with the help of the electric motor, the clutch connected between the internal combustion engine and the electric motor is partially engaged to a slipping condition where the clutch transmits a constant torque, and during this entrainment, and comparing an actual gradient of the combustion engine's speed produced with a nominal gradient of the combustion engine's speed. When the actual gradient is greater than the nominal gradient, the method concludes that the combustion engine is started and actively providing torque.

Method for operation of a drive train

A transmission control device () of a transmission () for a drivetrain which includes, in addition to the transmission (), a hybrid drive with an internal combustion engine () and an electric motor (). The transmission control device () stores parameters which form the basis of the manner with which gearshifts are controlled or regulated. At least some parameters are stored in duplicate, firstly, for operating the transmission () under purely electric-motor power using only the electric motor (), and secondly for operating the transmission () during hybrid driving using both the internal combustion engine () and the electric motor ().

Transmission control device

A method of operating a drivetrain of a motor vehicle which comprises a hybrid drive with a combustion engine coupled by a clutch to an electric motor. To start the combustion engine with the electric motor, the clutch is partially engaged to a slipping condition to deliver electric motor torque from a starting value, the torque transmitted by the clutch is increased to a first final value. If during this, the combustion engine begins turning, the break-away torque of the internal combustion engine is determined. If the combustion engine does not begin turning, the clutch is further engaged to a slipping condition starting from a second initial value, such that torque transmitted by the clutch increases linearly until the combustion engine begins turning, and the break-away torque of the internal combustion engine is determined from the clutch torque at which the combustion engine begins turning.

Method for operating a drive train

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

A method for operating a hydraulic system of an automatic transmission, in particular in a hybrid drivetrain, in which the hydraulic system comprises a main pump that is powered by an internal combustion engine and/or an electric drive motor, an electric auxiliary pump and a system pressure valve for setting a system pressure, to ensure various operating functions. In addition to the main pump, the electric auxiliary pump also supplies the hydraulic system with a volume flow of an operating medium. The loading of the electric auxiliary pump is determined in an electronic control unit with regard to the value of the system pressure and the loading of the electric auxiliary pump is limited, by the electronic control unit, with regard to the selected operating function.

Method of operating an auxiliary electric pump

A method of controlling a hybrid drive-train of a vehicle in which the hybrid drive-train comprises a combustion engine having a driveshaft, an electric machine that can be connected to the driveshaft of the engine by a clutch, an automated transmission with an input which is connected to the rotor of the electric machine, and shifting elements for shifting between two gears. During electric driving operation with the engine stopped and the clutch disengaged, the engine can be drag-started in combination with a downshift in the transmission. Drag starting of the engine is carried out by disengaging the frictional shifting element to be disengaged to below a slipping limit, engaging the clutch until the engine reaches or exceeds its minimum starting speed, starting the engine self-starts, substantially disengaging the clutch, separately adjusting the engine and electric machine to the synchronous speed of the target gear, and fully engaging and disengaging associated shifting elements.

Method for controlling a hybrid drive train of a vehicle

A method for operating a drivetrain of a motor vehicle including a hybrid drive with a combustion engine and an electric motor. A transmission is arranged between the hybrid drive and a drive output and a clutch is arranged between the combustion engine and the electric motor so that, if a failure occurs in the drivetrain, especially in a transmission control device of the transmission, a gear corresponding to an emergency gear is engaged or remains engaged in the transmission. When the emergency gear is engaged, the motor vehicle is in motion and the engine speed falls below a defined value, the clutch arranged between the combustion engine and the electric motor disengages.

Method for operating a drivetrain

A method of controlling a hybrid drive train of a vehicle which comprises, in series, an internal combustion engine, a clutch, an electric motor and a transmission with an output connected to the drive axle. During traction operation, the vehicle changes from an electric driving mode into a combination driving mode or a combustion engine driving mode, in that the clutch is engaged and the electric torque is temporarily increased. The method includes regulating engagement of the clutch at least until reaching a starting rotational speed of the combustion engine such that the acceleration of the combustion engine occurs according to a predetermined progression of rotational speed and that the torque of the combustion engine is increased by the same amount as the transferable torque of the clutch is increased by the engagement process.

Method to control a hybrid drive train

A method for operating an automatic transmission of a motor vehicle, in particular a variable-speed automatic transmission. The automatic transmission has five shift elements and for transferring torque or force in a forward gear and in a reverse gear at least three of the five shift elements are engaged. In a neutral position of the automatic transmission, to prevent torque or force flow at least one of the shift elements that are engaged in the respective forward or reverse gear is fully disengaged.

Method for operating an automatic gearbox

A method for operating a drivetrain of a motor vehicle. The drivetrain includes at least a hybrid drive with an internal combustion engine and an electric motor, a clutch arranged between the internal combustion engine and the electric motor, and a transmission arranged between the hybrid drive and a drive output. When the vehicle is at rest, the clutch arranged between the internal combustion engine and the electric motor is filled at least with filling pressure and then, when the vehicle is started, if the starting torque desired by the driver is above a limit value, the internal combustion engine is immediately turned over and started up by the electric motor, whereas, when starting, if the starting torque desired by the driver is below the limit value, then on starting, the internal combustion engine is not turned over by the electric motor.

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Kressbronn, Germany

Bernd Allgaier