Patent ID: 9315180
Filing Date: 2016-04-19
CPC Classification: B60T

Claim Text:
1. A brake system for motor vehicles having multiple wheel brakes, which brake system can be actuated both by a vehicle driver in a brake by wire operating mode and also independently of the vehicle driver in the brake by wire operating mode, which is normally operated in the brake by wire operating mode, and can be operated in at least one fall-back operating mode in which only actuation by the vehicle driver is possible, comprising, a brake pedal for actuating a pedal decoupling unit having a housing, with two pistons which are arranged in series and which, in the housing, delimit two pressure chambers, the pistons are subjected to an actuating force when the brake pedal is actuated by the driver, and the pistons are positioned in an initial position by restoring springs when the brake pedal is not actuated, a pressure medium reservoir which is assigned to the pressure chambers and which is at atmospheric pressure, a travel measuring device which measures the actuating travel of the brake pedal or of one of the pistons which is connected to the brake pedal, a travel simulator with a simulator enable valve which, in the brake by wire operating mode, enables a haptic brake pedal feel to the vehicle driver, the travel simulator being hydraulically connected to one of the pressure chambers, and the action of travel simulator can be deactivated in the fall-back operating mode, an electrohydraulic pressure generating device which outputs a brake system pressure, a pressure modulation unit which has an inlet valve and an outlet valve for each corresponding wheel brake of the wheel brakes of the vehicle for setting wheel-specific brake pressures derived from the brake system pressure, wherein the inlet valves transmit the brake system pressure when in a non-actuated state, wherein the wheel brakes are arranged in two brake circuits, each brake circuit includes an associated system pressure line which connects inlet ports of the inlet valves corresponding to the brake circuit to each other, cut-off valves for isolating the pressure chambers from the pressure modulation unit, and an electronic control and regulating unit, for each individual brake circuit of the two brake circuits, one electrically actuatable activation valve associated with each individual brake circuit interposed in terms of circuit layout between the pressure generating device and the pressure modulation unit, the activation valve, when in an actuated state, provides a hydraulic connection between the pressure generating device and the corresponding system pressure line; wherein for each individual brake circuit, the one electrically actuatable activation valve associated with each individual brake circuit is the only electrically actuatable valve disposed between the pressure generating device and each of the associated system pressure lines.