Method for controlling a hydrodynamic retarder which can be disengaged mechanically via a separating clutch

摘要

There is provided a method for controlling a hydrodynamic retarder. The method includes determining a presence of a retarder switch-off request, and keeping a separating clutch closed, after the determining, for a preset time span and emptying a working chamber of the hydrodynamic retarder of a working medium by continuous actuation of a rotating bladed rotor and interruption of infeed of the working medium into the working chamber. The method further included varying the preset time span according to at least one of the following parameters or at least one parameter correlated with one of the following parameters: a rotational speed of the rotating bladed rotor, an output pressure, against which the working medium is emptied from the working chamber, a filling level of the working chamber with the working medium, a temperature of the working medium, and a braking torque of the hydrodynamic retarder.

主权项

1. A method for controlling a hydrodynamic retarder which can be disengaged mechanically via a separating clutch in a motor vehicle, the hydrodynamic retarder including a rotating bladed rotor and a bladed stator or a rotating bladed rotor and a bladed counter-rotor rotating in an opposite direction thereto, which together form a working chamber filled with a working medium in a braking operation and emptied of the working medium in a non-braking operation, wherein the rotating bladed rotor is driven in the braking operation via a drive train with a closed separating clutch and the working chamber is emptied when passing from the braking operation to the non-braking operation and the separating clutch opens, wherein a transition from the braking operation to the non-braking operation is initiated via a retarder switch-off request of a driver assistance system or via an actuation of an input device by a vehicle driver, the method comprising:
determining a presence of the retarder switch-off request; keeping the separating clutch closed, after the determining, for a preset time span and emptying the working chamber of the hydrodynamic retarder of the working medium by continuous actuation of the rotating bladed rotor and interruption of infeed of the working medium into the working chamber; varying the preset time span according to at least one of the following parameters or at least one parameter correlated with one of the following parameters:
a rotational speed of the rotating bladed rotor;an output pressure, against which the working medium is emptied from the working chamber;a filling level of the working chamber with the working medium;a temperature of the working medium; anda braking torque of the hydrodynamic retarder.