A METHOD FOR CREATING LOW PRESSURE IN A BRAKE ACTIVATION DEVICE OF A MOTOR VEHICLE BRAKE SYSTEM

摘要

The invention relates to a method for creating low pressure in a brake activation device of a motor vehicle brake system comprising a pneumatic brake force booster (1), of which the inside is divided into at least one low-pressure chamber and one work chamber, one main brake cylinder (2), and a pneumatic motor pump unit (3) for creating the low pressure in the low-pressure chamber, which comprises a low-pressure pump (6) and a motor (7) that drives the low-pressure pump (6). During the process, the low pressure in the low-pressure chamber, or the pressure difference between the low-pressure chamber and the work chamber, is recorded by a sensor (9), and the motor pump unit (3) is switched on by an electronic control unit (12) if a predefined, first, lower low-pressure level Pe is not achieved, and is switched off when a predefined, second, upper low-pressure level Pa is reached. To ensure the adequate performance of the brake force booster (1) when using the low-pressure pump (6) as the sole supplier of low pressure, the invention recommends that the predefined, first, lower low-pressure level Pe and the predefined, second, upper low-pressure level Pa in the low-pressure chamber are controlled depending on the speed v of the vehicle.