Patent ID: 8449047
Filing Date: 2013-05-28
Classification: B60T

Abstract:
1. A brake system for a motor vehicle comprising: a master cylinder to which wheel brake cylinders are connectable; a first piston which is coupled to a brake pedal via a push rod that transmits actuating forces; a second piston which can be actuated by the first piston and which can be brought into force-transmitting connection to a third piston via which the master cylinder is actuated; at least one elastic element which forms a pedal travel simulator which, in a brake-by-wire operating mode, gives a driver of the vehicle a pedal sensation; means for coupling movements of the first piston and of the second piston, with the result that the pedal travel simulator is either switched on or switched off; an interspace capable of being acted upon with hydraulic pressure, between the second piston and the third piston, wherein pressure upon the interspace loads the second piston and the third piston in opposite directions; an electrically controllable pressure supply device which has a high-pressure source and which allows both a filling of the interspace with pressure medium and emptying thereof; and a valve device that is configured to vary pressure that is fed in the interspace, wherein the means for coupling the movements of the first piston and of the second piston comprise a further piston which can be acted upon by the hydraulic pressure provided by the pressure supply device, and wherein the further piston restricts movement of the first piston in an event of an absent pressure supply and allows a movement of the first piston with the effect of the actuation of the pedal travel simulator when acted upon by the hydraulic pressure provided by the electrically controllable pressure supply device.