Fluid pressure control system with an accumulator responsive to a loss of system pressure

摘要

A fluid pressure control system which includes an operational reaction force generating device having a piston which includes a front surface facing a pressure chamber and is operatively connected to an operating member so as to reduce a volume of the pressure chamber in response to the operation of the operating member. The fluid pressure control system further includes a fluid pressure control valve capable of adjusting and outputting an output pressure from a fluid pressure supply source capable of outputting a constant fluid pressure in accordance with the operation amount of the operating member and a stroke accumulator connected to the pressure chamber. The stroke accumulator is of a structural arrangement such that the resilient biasing force acting on the accumulator piston by the movement of the back-up piston toward the accumulator piston with the abnormal reduction in fluid pressure in the pilot chamber connected to the fluid pressure supply source is increased more than the fluid pressure acting on the accumulator piston when the fluid pressure in the pilot chamber is normal. Thus, it is possible in the fluid pressure control system of this invention to prevent the amount in which the operating member operates from being increased more than necessary when the output fluid pressure from the fluid pressure supply source is abnormally reduced.