Zf Friedrichshafen Ag

Christoph Rüchardt

Mario Steinborn

Marcus Gansohr

Klaus Schweiger

Otto Ebner

Andreas Schwenger

Matthias Winkel

Thomas Knoblauch

Thomas Jäger

Roland Mair

Jochen Breuer

Melchor Moro-Oliveros

A method for controlling a pneumatic actuator () of a transmission having at least one sealing element () that is arranged between two elements () of the actuator () that move relative to one another, and within a specifiable operating temperature range in which a leakproofness of the actuator () is ensured. The pneumatic actuator is acted upon with compressed air from an air supply system for actuating a transmission component. When a temperature of the actuator () is below a glass transition temperature of the at least one sealing element (), the actuator () is acted upon with pre-heated compressed air from the air supply system to warm up the at least one sealing element () above the glass transition temperature.

Method for controlling a pneumatic actuator

A method for controlling a pneumatic actuator () of a transmission having at least one sealing element (), arranged between two elements () of the clutch actuator () that move relative to one another, and within a specifiable operating temperature range in which leakproofness of the clutch actuator () is ensured. The clutch actuator () is acted upon with compressed air from an air supply system for actuating a shifting and/or starting clutch arranged between a drive aggregate and a transmission. In order to warm up the clutch actuator (), if a temperature of the clutch actuator () is lower then a glass transition temperature of the at least one sealing element (), the drive aggregate is operated at a higher rotational speed compared to the idling speed of the drive aggregate.

Method for warming-up a pneumatic clutch actuator

A method of operating a vehicle drive train () comprising a combustion engine (), a turbo charger () assigned to the combustion engine, a mechanism for the injection of additional compressed air into an air intake system () of the combustion engine (), a start and shift clutch (), and a transmission (). To optimally prepare and execute a start procedure of such an equipped vehicle, additional compressed air is only injected into the air intake system () of the combustion engine () if, depending upon the actual operating situation of the vehicle, the injection of additional compressed air benefits the safety of the driver, fuel consumption, drive comfort and/or the clutch wear.

Method for controlling a compressed air supply of an internal combustion engine during a starting process

A method is proposed for determining a clutch application point in a transmission of a vehicle having a spring-actuated clutch system in which the clutch application point is adapted according to at least one adequate regulated quantity of the clutch system.

Method for determining the clutch application point

A known device for increasing the functional reliability for a hydraulic circuit of a hydraulic clutch having a pressure reservoir () and a release cylinder () which comprises a primary piston () and a secondary piston (). A compensation volume is developed in the sense that when the vehicle is at a standstill and the parking brake released, an unintentional release of the clutch is prevented. A pressure-monitoring/pressure-supply device () is used for determining a reference operating pressure and establishes a static pressure which, in case of any system error, only allows displacement of the secondary piston () such that the contact pressure of the clutch discs, against one another, is still sufficient to maintain the vehicle at a standstill.

Device for increasing the functional reliability of a hydraulic circuit of a hydraulically operable clutch

A method for clutch actuation at low temperatures for a motor vehicle having a hydraulically actuatable clutch, below a predetermined temperature a situation-dependent pre-opening of the clutch is executed when a braking is probable.

Method for actuating a clutch at low temperatures

A device for rendering a hydraulic actuating device operational. A motor vehicle clutch with an emitter-receiver system located in the transmission path of the actuating device comprising two pistons whose positions, relative to one another, can vary as a function of the desired operating behavior of the actuating device and is developed further such that in relation to the emitter-receiver system that is to be filled with fluid, operationality can be established comparatively quickly and by simple way. A fluid supply unit () comprises one impulse valve () that serves to release an essentially constant volume flow, acted upon by an impulse valve control device () which is constructed such that the fluid volume flow released by the fluid supply unit () and flowing into the emitter-receiver system () does not exceed a limiting volume flow Q.

Device for rendering operational a hydraulic actuating device

An operating time is determined by an approximation method within the scope of the method for determining the actual operating time of a hydraulic, electrohydraulic or electric component of a motor vehicle or of a working machine within a reference time or a monitoring period.

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Bodolz, Germany

Christoph Rüchardt