Method for actuating a retarder of a motor vehicle

摘要

A method of actuating a retarder of a motor vehicle, for example a hydrodynamic retarder of a commercial vehicle, in which during overrun operation the driver uses an operating element to call for a braking action by the retarder. To implement the method simply, conveniently and inexpensively, the accelerator pedal of the motor vehicle is used as the operating element for demanding a braking action by the retarder. In such manner that when the torque of the drive engine of the motor vehicle becomes negative due to overrun operation, the braking action demand is signaled by at least partially releasing the accelerator pedal.

主权项

1. A method of actuating a retarder for a motor vehicle during overrun operation of the motor vehicle, the method comprising the steps of:
monitoring engine torque with a control unit; when a negative engine torque is recognized, monitoring a position of an accelerator pedal via sensor signals that are delivered to the control unit; actuating a retarder to apply retarder braking torque; applying a retarder braking torque when the accelerator pedal is released to a threshold pedal position, and while the engine torque is recognized as being negative; adjusting the retarder braking torque proportionally to the accelerator pedal position when the accelerator pedal is released to pedal positions between the threshold pedal position and a second pedal position, and while the engine torque is recognized as being negative; and applying a maximum retarder braking torque when the accelerator pedal is released to pedal positions beyond the second pedal position, and while the engine torque is recognized as being negative.