ACTUATING UNIT FOR AN ELECTROHYDRAULIC BRAKING SYSTEM

摘要

The invention relates to an actuating unit (1) for an electrohydraulic braking system of the "brake-by-wire" type, which is configured as a dual master cylinder (2), whose first (20) and second pistons (30) are respectively tensioned against the direction of actuation by a return spring (114, 115). The first pressure chamber (4) of the dual master cylinder is connected to a hydraulic chamber (119, 219) which is delimited by a simulator element (118, 218). On its other side, said simulator element (118, 218) delimits a simulator chamber (121, 221) which accommodates a simulator spring (122) and is connected to a storage container (6) for hydraulic fluid. A valve device (123, 124, 217, 224; 140) that closes or releases the hydraulic connection (123, 217) between the simulator chamber (121, 221) and the hydraulic fluid storage container (6) or the first pressure chamber (219) and the hydraulic chamber (219) is also provided. To increase the operational safety of a braking system equipped with the inventive actuating unit, the invention is characterized in that means (50, 116) for testing the function of the valve device (123, 124; 217, 224; 140) are provided.