Actuator for an electronically controllable brake actuation system

The invention relates to an actuation unit for an electronically regulated braking system for automobiles. The inventive actuation unit consists of a pressure generator which is actuated by means of an operating pedal and a simulator which interacts with the pressure generator and which has a simulator spring. The aim of the invention is to produce a harmonic pedal characteristic and to considerably improve the haptic feel of the pedal so that it corresponds to a large extent with human ergonomics. To this end, the simulator (15) is formed by metallic bellows (17) which are impinged upon by the hydraulic pressure controlled in the pressure generator (2). The area inside the bellows accommodates the simulator spring (18) and can be connected to a reservoir (7) for the pressure means.