Patent ID: 7264318

Claim:
A brake pressure control arrangement for a hydraulic vehicle braking system of a vehicle having wheels with brakes, comprising: a hydraulic actuating unit ( 2 ) actuatable by an operator of the vehicle, receiver units ( 15 , 15 ′) in communication with the hydraulic actuating unit for operating the brakes ( 16 , 16 ′) of the wheels, at least one pump unit ( 25 , 25 ′) connected to the receiver units ( 15 , 15 ′) via a communication line ( 18 , 18 ′) including control valves ( 19 , 19 ′, 22 , 22 ′) for controlling admission of hydraulic fluid to, and its release from, the receiver units ( 15 , 15 ′), an intake flow control valve ( 27 , 27 ′) arranged between the actuating unit ( 2 ) and the pump unit ( 25 , 25 ′), the intake flow control valve ( 27 , 27 ′) being an over-pressure valve subjected to the pressure of the actuating unit ( 2 ) in an opening direction and having a controllable opening pressure behavior, and a control unit ( 29 ) for controlling the control valves and the intake flow control valve in such a way that, with the actuating unit ( 2 ) actuated, in a first operating state, the receiver units are, in intervals, connected only to the suction side of the pump unit ( 25 , 25 ′) so as to reduce the hydraulic pressure therein, and, in a second operating state, the receiver units ( 15 , 15 ′) are connected to the pressure side of the pump unit ( 25 , 25 ′) for supplying pressurized hydraulic fluid to the receiver units ( 15 , 15 ′) and the pump suction side is in communication with the actuating unit ( 2 ) such that the hydraulic fluid volume supplied to the receiver unit is determined solely by the intake flow volume of the receiver unit ( 15 , 15 ′) as provided by the pump unit ( 25 , 25 ′) and, with the actuating unit not operated, in a third operating state, the pump unit ( 25 , 25 ′) is connected with its intake side to the actuating unit and with its pressure side to the receiver unit ( 15 , 15 ′), and a normally closed shutoff valve ( 20 , 20 ′), which is arranged parallel to the intake flow control valve ( 27 , 27 ′) in a circuit branch extending between the actuating unit ( 2 ) and the intake side of the pump unit ( 25 , 25 ′) and which, in the third operating state, is opened by the control unit ( 29 ).