Brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type, and method for operating a motor vehicle braking system by means of such a brake actuating unit

摘要

A brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type having a brake booster. In order to provide a brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type, which on the one hand fulfills the statutory requirements care and which on the other hand is inexpensive to produce, it is proposed according to aspects of the invention, that the brake booster be provided as a travel-controlled brake booster, so that when not in the “brake-by-wire” operating mode the brake pedal is decoupled from feedback forces of the brake actuating unit, and the return force is simulated by the pedal travel simulator even when not in the “brake-by-wire” operating mode.

主权项

1. A brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type, wherein the brake actuating unit comprises:
a brake booster having a booster housing, the interior of which is divided by at least one moveable wall into a vacuum chamber and a working chamber, and having a control housing which supports the moveable wall and in which a control valve is arranged, which controls a pneumatic pressure differential acting on the moveable wall, wherein the control valve can be actuated by a solenoid both by an input element that can be subjected to an input force and brought into a force-transmitting connection with a brake pedal, and also by means of an electronic control unit, wherein a distance (a), which allows a decoupling of a force-transmitting connection between the brake pedal and the brake booster in the “brake-by-wire” operating mode, is provided between the brake pedal and the brake booster, a brake master cylinder which is connected to the output side of the brake booster and to the piston of which an output force of the brake booster is transmitted, means for detecting the actuation travel of the brake pedal, and a pedal travel simulator, which interacts with the brake pedal and which serves, in the “brake-by-wire” operating mode, to simulate a return force acting on the brake pedal irrespective of an actuation of the brake booster, wherein the brake booster is provided as a travel-controlled brake booster, so that when not in the “brake-by-wire” operating mode the brake pedal is decoupled from feedback forces of the brake actuating unit, and the return force is simulated by the pedal travel simulator even when not in the “brake-by-wire” operating mode.