Vehicle brake system with brake support mechanism

摘要

The braking system is designed so that if the lifting speed exceeds a reference value of a lifting speed threshold value, a solenoid is switched on to attract an armature. An air valve is opened independently of the position of a plunger piston. As a consequence, power pistons (6a,b) are moved forward together with an output rod by a thrust, according to a pressure difference between a constant pressure chamber (7a,b) and a variable pressure chamber (8a,b). In order to carry out a braking operation with full power, a reaction adjusting mechanism operates so that if a part of the reaction force of the output shaft, which is transmitted to the input rod reaches a predetermined value, a reinforcing ratio is increased so that the reference value of a lifting speed threshold value can be adjusted to 'high', in order to prevent unnecessary braking.