Unterdruck-Bremskraftverstärker mit mechanischer Notbremshilfe

摘要

The invention relates to a vacuum brake booster (10) comprising a vacuum chamber (16), a working chamber (18) which is separated from said vacuum chamber by a moveable wall, and a control valve (20) comprising a housing (12) which is coupled to the moveable wall in a force-transmitting manner (14). Said control valve is able to control the supply of atmospheric pressure or vacuum to the working chamber (18) according to the displacement of an actuating piston (28), in order to obtain a pressure difference on the moveable wall (14). The inventive vacuum brake booster (10) comprises an emergency braking auxiliary system having a permanent magnet (38) and an armature (36) which interacts with the permanent magnet (38). Said armature is elastically pre-stressed against the actuating direction and is pulled by the permanent magnet (38) in the event of emergency braking in the system, in such a way that the control valve (20) is held open for the supply of atmospheric pressure to the working chamber (18). The vacuum brake booster (10) comprises a coupling device (90) for detachably coupling the armature (36) to the actuating piston (28).