CONTROL VALVE ASSEMBLY FOR A PARKING BRAKE SYSTEM FOR MOTOR VEHICLES AND PARKING BRAKE SYSTEM FOR MOTOR VEHICLES

摘要

The present invention relates to a control valve assembly (20) for a parking brake system (1) for motor vehicles, comprising a housing (60); comprising a cylinder chamber (62) and a housing chamber (64), a control piston (66) guided in the cylinder chamber (62) of the housing (60), a spring (21) which spring loads the control piston (66); comprising a first port (20a) and a second port (20b), which are connected to the housing chamber (64), and a third port (20c), which is connected to the cylinder chamber (62); wherein the control piston (66) has a first piston ring (68) and a second piston ring (70); wherein the first piston ring (68) is guided in the cylinder chamber (62) and wherein the second piston ring (70) is located outside the cylinder chamber (62) in the housing chamber (64); wherein in a first control position the second piston ring (70) seals the cylinder chamber (62) with respect to the housing chamber (64) and in at least one second control position the cylinder chamber (62) and the housing chamber (64) are interconnected; wherein in the first control position the pneumatically acting surfaces of the first piston ring (68) and the second piston ring (70) are substantially identical. The present invention also relates to a parking brake system (1) for motor vehicles.