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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2014/195051
Kind Code:
The invention relates to a method for controlling a hydrodynamic retarder in a motor vehicle, which hydrodynamic retarder can be disengaged by a disconnect clutch. The motor vehicle has a drive motor, the power output of which can be controlled by means of an actuator such as a foot pedal or lever and which drive motor is operated in a first operating state, called traction operation, in dependence on the operation of the actuator, in which traction operation drive power of the drive motor is transmitted to drive wheels by means of a drive train of the motor vehicle in order to accelerate the motor vehicle, and in a second operating state, called overrun operation, in which drive power is transmitted from the drive wheels into the drive train. The hydrodynamic retarder has a driven bladed rotor and a bladed stator or a driven bladed rotor and a bladed counter-rotating rotor driven in a direction opposite the direction of the driven bladed rotor, which together form a working chamber that can be filled with a working medium and drained of said working medium, and the rotor can be selectively disengaged from the drive train and connected to the drive train in a rotationally fixed manner by means of a disconnect clutch, such that, in braking operation initiated by a vehicle driver or driver assistance system, the rotor is driven via the closed disconnect clutch in relation to the stationary stator or in a direction opposite the direction of the counter-rotating rotor and, with the working chamber filled, torque is transmitted from the rotor to the stator or the counter-rotating rotor, and, in non-braking operation initiated by the vehicle driver or the driver assistance system, with the disconnect clutch open, the drive power transmission to the rotor and/or the counter-rotating rotor is interrupted and the working chamber is drained of the working medium. In the transition from the non-braking operation to the braking operation, the disconnect clutch is closed and the working chamber is filled with working medium, and, in the transition from the braking operation to the non-braking operation, the working chamber is drained of the working medium and the disconnect clutch is opened simultaneously or at a delay. The method is characterized in that, in the overrun operation, an acceleration of the motor vehicle is detected or determined and compared with a specified acceleration limit value, and, in the non-braking operation, the disconnect clutch is closed independently of an initiation of the braking operation by the vehicle driver or the driver assistance system and the working chamber is kept drained if the acceleration lies above the acceleration limit value.

ADAMS, Werner (Melanchthonstr. 9, Crailsheim, 74564, DE)
LAUKEMANN, Dieter (Sonnenstraße 10/1, Crailsheim, 74564, DE)
MENNE, Achim (Am Ebenrain 4, Crailsheim, 74564, DE)
SCHADE, Ravi (Reußenbergstr. 64/2, Crailsheim, 74564, DE)
Application Number:
Publication Date:
July 23, 2015
Filing Date:
April 15, 2014
Export Citation:
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VOITH PATENT GMBH (Sankt Pöltener Straße 43, Heidenheim, 89522, DE)
International Classes:
B60T7/18; B60T10/02; F16D57/04; F16D67/02
Foreign References:
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