SYSTEME DE FREINAGE HYDRAULIQUE POUR VEHICULE AUTOMOBILE, COMPORTANT UN AMPLIFICATEUR DE FORCE HYDRAULIQUE

A hydraulic brake system for automotive vehicles with a master brake cylinder (51) and with a hydraulic power booster (49) connected upstream of the master brake cylinder, in which a pressure medium pump (18) which may be driven by an electric motor (17) is used for providing an auxiliary hydraulic energy, the drive of which may be switched on by a pressure accumulator (1), on the one hand, and by a brake pedal contact (58), on the other hand, in the unbraked operation of the automotive vehicle the pressure accumulator (1) permanently being kept on a pressure level sufficient for an initial actuation of the brake and the charge of the pressure accumulator (1) being monitored by a pressure control valve (19). In view of an energy demand of the brake system which will be as low as possible, this invention suggests that a valve passage (40, 42) of the valve arrangement (19) is operable by a pressure in the booster chamber of the hydraulic power booster (49) such as to establish a direct communication between the outlet of the pressure medium pump (18) and the pressure medium port of the hydraulic power booster (49).