METHOD FOR CONTROLLING A BRAKE PRESSURE BOOSTER

摘要

A method for controlling a brake pressure booster with hydraulic brake boosting wherein the activation of an additional pressure source takes place upon exceeding a specified brake cylinder pressure threshold value. The threshold value lying, between 50% and 100%, preferably between 70% and 80%, of a pressure limit value, from which the operating travel/brake pressure curve without additional brake pressure assistance has a knee point. Further upon exceeding a specified piston rod activation travel limit value, which lies at 20% to 100% of the available travel, preferably at 40% to 60% of the available travel. Furthermore, the speed of the vehicle, its lateral deceleration and its longitudinal deceleration can be used as criteria. Deactivation takes place on falling below a specified piston rod deactivation travel limit value. Based on selection of activation/deactivation criteria additional brake pressure boosting can be operationally during braking maneuvers.

主权项

1. A method for controlling a brake pressure booster with hydraulic brake pressure boosting in a motor vehicle, the brake pressure booster comprising:
providing a tandem brake master cylinder connected directly or indirectly via a piston rod to a brake pedal for applying brake fluid to the service brakes of the motor vehicle; providing an additional hydraulic pressure source that can be selectively activated or deactivated by means of a control device depending on various engine operating parameters and whose pressure fluid in the case of activation assists the brake pressure applied by the brake pedal; and recording at least the pressure in the tandem brake master cylinder and the piston rod travel of the tandem brake master cylinder by the control device wherein activation of the additional pressure source takes place with the cumulative presence of at least the following criteria: a) exceeding a specified tandem brake master cylinder pressure threshold value of between 50% and 100% of a pressure limit value, from which the operating travel/brake pressure curve comprises a knee point without additional brake pressure assistance, and b) exceeding a specified piston rod activation travel limit value of 20% to 100% of the available travel.