The pneumatic brake booster is complementary and hydraulic boosting the braking assistance with such a booster

摘要

An air compressed brake booster with mixed pneumatic-hydraulic brake system is improved by providing complementary hydraulic power-assist (19, 20) supplied by a hydraulic circuit beyond a saturation point (Psat) of the pneumatic circuit operating conditions, taking into account (50) hysteresis instability phenomena of the pneumatic part of the brake booster, selecting to compensate (A) by said hydraulic circuit the defect in the operating conditions of the pneumatic circuit. In one embodiment, said correction is produced by means of a microprocessor which imposes a corrected processing signal. With said signal, pressure offsets in the pneumatic system are neutralised.