Patent ID: 8500222
Filing Date: 2013-08-06
Classification: B60T

Abstract:
1. An activation unit of a brake-by-wire system for a motor vehicle, having: a) a brake booster which is configured to be activated either by a brake pedal or as a function of a driver's request or independently of the driver by an electronic control unit, with a mechanism to permit decoupling of a force-transmitting connection between the brake pedal and brake booster in a “brake-by-wire” operating mode being provided between the brake pedal and the brake booster, b) a master brake cylinder which is connected downstream of the brake booster, c) means for sensing a driver's request or an activation travel of the brake pedal, d) a pedal travel simulator which interacts with the brake pedal and by means of which a restoring force which acts on the brake pedal in the “brake-by-wire” operating mode can be simulated independently of activation of the brake booster, and e) a hydraulic activation and deactivation device which activates the pedal travel simulator in the “brake-by-wire” operating mode and deactivates the pedal travel simulator outside of the “brake-by-wire” operating mode, and which is formed by a cylinder-piston arrangement whose pressure space is connected by a disconnectable connection to a pressure medium volume accommodating element and on whose piston a simulator housing is supported via a piston rod, wherein a connection having three degrees of freedom is provided between the piston and the piston rod, wherein the connection between the piston and the piston rod is embodied as an articulated connection in which the piston rod has a spherical articulation head, and the piston is provided with a correspondingly formed head receptacle, wherein the piston rod has a ball segment shaped section that is separate from the spherical articulation head which, in the unactivated position of the cylinder-piston arrangement, bears against a correspondingly shaped stop element that is separate from the piston, wherein in an activated position of the cylinder-piston arrangement, the spherical articulation head is separated from the correspondingly shaped stop element.