Zf Friedrichshafen Ag

Zahnradfabrik Friedrichshafen, Ag.

Klaus Schweiger

Marcus Gansohr

Christoph Rüchardt

Otto Ebner

Andreas Schwenger

Matthias Winkel

Thomas Knoblauch

Manfred Schwab

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.

Method for calculating the operating time of hydraulic components

Gear-shift control and gear-range selector for a semi-automatic or

A shifting system used in combination with a motor-vehicle engine having an output connected via a clutch to the input of a multiratio transmission in turn having an output connected to a load comprises respective sensors for detecting the speeds of the motor output, transmission input, and transmission output and for generating outputs corresponding thereto, and respective clutch and transmission sensors for detecting the settings of the clutch and transmission and generating outputs corresponding thereto. A shifter element can move between an actuated position and an unactuated position. A double-display has a current-setting part and an ideal-setting part and is connected to a controller that is also connected to the sensors. This controller displays on the current-setting part the current setting of the transmission and on the ideal-setting part a setting calculated to be ideal based at least on engine characteristics and transmission output speed. In addition it resets the transmission by means of its actuator to the ideal setting when same is different from the current setting, the selector element is in the drive position, and the shifter element is actuated. It also disengages and engages the clutch by means of its actuator on any transmission speed change and engaging the clutch by means of its actuator on startup of the motor vehicle from halt.

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Friedrichshafen, Germany

Klaus Schweiger