BRAKING SYSTEM FOR MOTOR VEHICLES WITH ELECTRIC DRIVE

摘要

A braking system for motor vehicles with electric drive has an hydraulic pressure transmitter and uses hydraulic friction brakes to enhance the braking action produced by the electric drive motor. The combined action of the electric drive motor with the hydraulic friction brakes is controlled by an electronic control unit. To raise the operational reliability of the braking system by providing for an hydraulic pressure build-up in the friction brakes on the driven axle in the event of a failure of the electronic control unit or of the vehicle's entire electrical system, the invention proposes that the pressure transmitter (2) is designed as a two-circuit main brake cylinder, the first pressure chamber (22) of which is linked with the friction brakes (3, 4) acting on the non-driven axle and the second pressure chamber (23) of which is linked with the friction brakes (5, 6) acting on the driven axle, with the connection between the second pressure chamber (23) and the friction brakes (5, 6) acting on the driven axle being effected via at least one electrically switchable return flow locking valve (20) that is open when currentless.