Method and apparatus for controlling brake pressure in vehicle brake systems

An apparatus for controlling and adapting brake pressure in a vehicle brake system, comprising a hydraulic brake booster provided with an associated pedal-actuated brake valve for feeding a pressure medium from a pressure medium supply means to at least one wheel brake cylinder in at least one closed brake circuit between said brake booster and said at least one wheel brake cylinder, at least one supplementary pump piston being provided in said at least one closed brake circuit between said brake booster and said at least one wheel brake cylinder, said supplementary pump piston being provided with pressure supply and pressure withdrawal lines for regulating its supply of brake pressure and said supplementary pump piston has a pressure supply line for pressurizing said pressure chamber to a booster chamber of the hydraulic brake booster and said supplementary pump piston further has a return line connected via a second magnetic valve to the pressure medium supply means for depressurizing said pressure chamber, and said pressure supply and return lines include throttle means therein.

An apparatus for controlling and adapting brake pressure in a vehicle brake system, comprising a hydraulic brake booster provided with an associated pedal-actuated brake valve for feeding a pressure medium from a pressure medium supply means to at least one wheel brake cylinder in at least one brake circuit between said brake booster and said at least one wheel brake cylinder, at least one supplementary piston being provided in said at least one brake circuit between said brake booster and said at least one wheel brake cylinder, said supplementary piston being regulatable in its supply of brake pressure, and an electronic comparison and logic circuit is provided for detecting actual pressure values in the at least one brake circuit equipped with the at least one supplementary piston and for comparing said values selectively with a travel of at least one of a booster piston in the brake booster and a travel of a brake pedal, said logic and comparison circuit being arranged to deliver trigger signals selectively to a first magnetic valve to reduce pressure in a pressure chamber of the supplementary piston, said trigger signals serving to reproduce a predetermined set-point characteristic curve by clocking same against deviation from given set-point values and from regulatory deviation.

An apparatus for controlling and adapting brake pressure in a vehicle brake system, comprising a hydraulic brake booster provided with an associated pedal-actuated brake valve for feeding a pressure medium from a pressure medium supply means to at least one wheel brake cylinder in at least one brake circuit between said brake booster and said at least one wheel brake cylinder, at least one supplementary piston being provided in said at least one brake circuit between said brake booster and said at least one wheel brake cylinder, said supplementary piston being regulatable in its supply of brake pressure, said at least one brake circuit includes a first magnetic valve group which when actuated blocks the brake booster by blocking outflow of pressure medium from a rear chamber of the booster piston, and said at least one brake circuit includes a second magnetic valve group selectively operable to deliver pressure medium from a pressure supply means to a booster portion of the brake booster and to evacuate the booster chamber into a pressure medium return line.