Underpressure control, in a vehicle brake system, has a sensor to register underpressure levels for an electronic control to activate the vacuum pump to maintain the required level

摘要

To prepare the underpressure in a motor vehicle brake system, the pressure in the underpressure chamber or the pressure difference between the underpressure and working chambers in the brake force amplifier (1) is registered by a sensor (9). The motor pump assembly (3) is switched on by an electronic control (12) if the underpressure is below a certain level and is switched off when an upper level is achieved, taking the vehicle speed into account.