Zf Friedrichshafen Ag

Harry Nolzen

Markus Eisele

Jürgen Blaser

Otto Lutz

Dennis Wohlfahrt

Franz Sorg

Torsten Buchner

Thomas Vogt

Harm Adams

Juergen Blaser

A method for operating an automatic transmission () of a motor vehicle in which a hydraulic pump, associated with a hydraulic system, for supplying pressure in the hydraulic system is driven by a drive engine and in which hydraulic shifting elements (B, B, B, C, C) are actuated to engage gear steps. According to the method, before the drive engine is turned off for a short duration of time, at least one non-actuated shifting element (B, B, B, C, C) of the automatic transmission () is actuated or filled with pressure oil.

Method for operating an automatic gearbox of a motor vehicle

A method of shifting an automatic transmission of a motor vehicle having a hydrodynamic converter (). The method comprising the steps of detecting a presence of predetermined stopping conditions; determining that a driver of the motor vehicle intends to cause the motor vehicle to change from a driving state to a stopped state, based on the presence of one of the predetermined stopping conditions; and automatically shifting the automatic transmission () into a standby mode, before the driving state has concluded. The shifting into the standby mode typically occurs when a rotational speed of the hydrodynamic converter () decreases to less than a rotational speed () of a motor and the retarder apparatus (), of the automatic transmission, is disengaged no later than a time by which shifting into the standby mode occurs.

Method for shifting a motor vehicle automatic transmission with a hydrodynamic torque converter when the vehicle comes to a stop

A method of influencing an automated transmission of a motor vehicle having a tractional resistance detection unit, the method comprising the steps of reading data, via the tractional resistance detection unit, containing at least information about a torque of a drivetrain, a rotational speed of the drive train, and an acceleration of the vehicle, determining the external tractional resistance of the vehicle based upon the read data, and influencing the shift program by at least one of activation, adaptation and variation of the shift program, on a basis one of an actual and a statistically prepared data about the external tractional resistance of the vehicle.

Method for influencing an automatic gearbox, taking into consideration the tractional resistance

A method for determining characteristic parameter values within a transmission that includes, for example, hydraulically-operated shifting elements, hydro-dynamic brakes, and hydro-dynamic torque converters. Slip regulation is used to determine the actual slip at a transmission element, whose characteristic parameter values are to be determined, before engagement. This element to be adapted is activated by means of pressure application, and thus a specified slip is set that is clearly different from the actual slip at lower torques. The applied pressure or flow may be determined from the set slip, and occurrence of a set slip allows the occurring pressures to be determined.

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Tettnang, Germany

Harry Nolzen