Patent ID: 8657388
Filing Date: 2014-02-25
Classification: B60T

Abstract:
1. A brake system for motor vehicles comprising: a brake master cylinder that can be operated by a brake pedal, a fluid reservoir assigned to the brake master cylinder, a hydraulic booster chamber which is operatively connected to an inlet side of the brake master cylinder, with a booster piston which is subjected to a hydraulic boost pressure supplied by a pressure source and which in all operating modes allows a direct mechanical action by the brake pedal on a hydraulic piston of the brake master cylinder, a brake circuit operatively connected to an outlet side of the brake master cylinder, and a pressure regulating valve arrangement for metering a boost pressure, the pressure regulating valve arrangement directly hydraulically connected to the brake circuit, wherein the pressure regulating valve arrangement is electrically controllable in a first operating mode and is hydraulically controllable in a second operating mode, wherein the pressure regulating valve arrangement includes an electrically controllable pilot control stage comprising a pair of control valves and a hydraulic center tap between the pair of control valves, the center tap directly hydraulically connected with a control chamber of the pressure regulating valve arrangement, the control chamber defined between a pair of control pistons within the pressure regulating valve arrangement.