Zf Friedrichshafen Ag

Karl Locher

Martin-Joachim Bader

Markus Terwart

Olaf Moseler

Rainer Novak

Alexander Hoffmann

Mario Bühner

Dietmar Zuber

Robert Gronner

Michael Vollmann

Ahmet Macar

Frank Veth

The invention relates to a method for operating a vehicle drive train () comprising a prime mover (), comprising a transmission (), and comprising a driven end (). A friction-locking shift element () is provided, the power transmission capacity of which is variable and, with the aid of which, at least a portion of the torque transmitted in the vehicle drive train () can be transmitted between a transmission output shaft () and an area () of the driven end (). One shift-element half is operatively connected to the transmission output shaft () and the other shift-element half is operatively connected to the area () of the driven end (). The rotational speed of the transmission output shaft () is determined as a function of the rotational speed in the area () of the driven end () and also as a function of the rotational speed of the prime mover () and the ratio currently engaged in the area of the transmission (). In the event of a deviation between the rotational speed of the transmission output shaft () determined on the output end and the rotational speed of the transmission output shaft () determined on the transmission-input end, which is greater than or equal to a threshold value and/or an operating temperature in the area of the friction-locking shift element (), which is greater than or equal to a limiting value, measures reducing loads of the friction-locking shift element () are initiated.

Method for operating a vehicle drive train

A method for controlling a hydraulic fluid supply system of an automatic transmission of a motor vehicle includes supplying the hydraulic fluid supply system with hydraulic fluid from at least one of a hydraulic pump controlled on an engine side and a hydraulic pump controlled on a gear set side. The method also includes controlling a cooling valve of the hydraulic fluid supply system as a function of detected motor vehicle parameters in order to set an adjusted power distribution with the hydraulic pump controlled on the engine side and the hydraulic pump controlled on the gear set side.

Method for controlling a hydraulic-medium supply system of an automatic transmission

A method for controlling a hydraulic fluid supply system of an automatic transmission of a motor vehicle includes supplying the hydraulic fluid supply system with hydraulic fluid from at least one of a hydraulic pump controlled on an engine side and a hydraulic pump controlled on a gear set side. The method also includes controlling a retaining valve of the hydraulic fluid supply system as a function of detected motor vehicle parameters in order to set an adjusted power distribution with the hydraulic pump controlled on the engine side and the hydraulic pump controlled on the gear set side.

Method for actuating a hydraulic medium supply system of an automatic transmission

A method of determining a touch-point of a friction clutch of a motor vehicle that is relevant for control purposes such that a current, actual touch-point of the friction clutch is determined adaptively, and such that the current touch-point is modified, with a correction value that depends on the elasticity of the friction clutch, in order to determine the control-relevant touch-point. The control device comprises elements for carrying out the method.

Method and device for determination a touch point of a friction clutch

A method of operating a clutch serving as a shift element and/or starting clutch of a drive train. During engagement, the clutch will be filled by a fast filling up to a defined minimum pressure. The fast filling is at least subdivided into two phases comprising a basic filling phase and an extension and/or a cutout phase. At the end of the basic filling phase, the actual clutch pressure is measured, and then, when the actual clutch pressure is equal to or larger than the minimum pressure, the extension and/or cutout phase is activated immediately following the basic filling phase. When the actual clutch pressure is lower than the minimum pressure, activation of the extension and/or the cutout phase is at least delayed by a pressure holding phase and, if necessary, by a pressure surplus phase.

Method for operating a clutch

A method of adapting the rapid filling time of a clutch. During adaptation, the clutch is filled by at least two successive rapid filling pulses with increasing rapid filling times. For each rapid filling pulse a reaction, resulting from the filling pulse, is monitored. If a defined reaction, for one of the rapid filling pulses, is recognized for the first time whereas for the, or for each of the previous rapid filling pulse(s) the defined reaction was not observed, then as a function of the rapid filling time of that rapid filling pulse for which the defined reaction was recognized for the first time, carrying out the adaptation of the rapid filling time and, for each rapid filling pulse used for the adaptation, gradients of the clutch pressure produced as a result of the respective rapid filling pulse are evaluated to determine the defined reaction pressure.

Method for adapting the rapid filling time of a clutch

A method for determination of the synchronization point of an automatic double clutch transmission comprising two component transmissions each with one input shaft that connects via a friction clutch to the drive shaft of a motor and several gears, each shifted via a friction-synchronized gear clutch. The method includes the steps of selecting the gear clutch of a gear of a momentarily load-free component transmission; moving the associated gear setter to the neutral position as needed; successive movement of the associated gear setter in the direction of the shifting position of the selected gear until synchronous running is attained on the gear clutch within an applicable threshold; determination of the current synchronization point of the gear clutch from the current adjustment parameter of the associated gear setter; and adaptation of the valid synchronization point of the gear clutch to the current synchronization point.

Synchronous state determination method for automatic dual clutch transmission

A method for clutch characteristic curve adaptation of an automatic dual-clutch transmission which comprises two sub-gearboxes each with an input shaft connected, via a friction clutch, to the drive shaft of a motor and several gears that are shifted via a friction-synchronized gear clutch. A value of the current touch point of the friction clutch can be determined with the motor running and the gears disengaged in a load-free sub-gearbox. The method includes the steps of starting synchronization of a gear clutch with a defined force of a regulator. Waiting until the gear clutch is synchronized. Engaging the friction clutch of the until the gear clutch is synchronizes. Determination the current touch point from the current synchronous torque of the gear clutch and the current regulating parameter of the associated clutch regulator. Then, adapting the clutch characteristic curve of the friction clutch in view of the current touch point.

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Pfronstetten-Tigerfeld, Germany

Karl Locher