| 摘要 |
<p>In a hydraulic motor vehicle servo brake comprising a tandem master cylinder (11), a brake valve (17) is provided which upon actuation through the brake pedal (16) applies, in controlled manner, pressure medium supplied by a hydraulic pump (18) connected to an intake reservoir (27) to the first master piston (24) and to a brake circuit (III) directly, to provide there a controlled pressure. A wheel slip brake control system at an initial slip of one or more motor vehicle wheels, will reduce automatically the brake force on the motor vehicle wheels to a value just sufficient to turn the wheels. Two switch valves (21, 21') to which the controlled pressure is applied are normally closed and open upon a beginning slip of one or several motor vehicle wheels to apply the controlled pressure to the master cylinder (11) from where the pressure medium is passed by way of two check valves (23, 123) to the pressure chambers located behind the master pistons (24, 80). The switch valves are actuated by way of a differential pressure control circuit (148) in response to exceeding a predetermined pressure difference in the two pressure chambers (76, 176) such that the switch valve connected to a defective brake circuit will be closed.</p> |
