Hydraulische Fahrzeugbremsanlage

摘要

Hydraulic vehicle braking systems are known in which normal service brake operation can be carried using hydraulic extraneous energy whereas, when there is a lack of hydraulic extraneous energy, auxiliary braking operation can be carried out using muscle power with hydraulic transmission from a master cylinder which can be operated by means of the brake pedal. The hydraulic extraneous energy is stored, for example, in an accumulator with a gas cushion, which can result in gas being present in the pressure medium used for service brake operation. According to the invention, a dual-circuit master cylinder (9) is associated with those wheel brakes (5, 6) on a vehicle axle which make the greater contribution to vehicle deceleration. To that end, cylinder-piston arrangements (52, 53) are fitted between these wheel brakes (5, 6) and their associated service brake valves (27, 28) in order to ensure that hydraulic pressure medium does not pass out of the extraneous energy source and into these wheel brakes (5, 6). The advantage of the invention is that neither gas nor air is conveyed into the wheel brakes (5, 6) where it could produce bubbles when the pressure drops and have a negative effect on auxiliary braking via the master cylinder. The cylinder-piston arrangements (52, 53) increase the operational reliability of the vehicle braking system when braking is brought about by muscle power.