Device for detecting and eliminating accumulator fluid leakage through control valve

A hydraulically-operated brake system for a vehicle, including a brake operating member, a hydraulic power source for generating a first hydraulic pressure in response to an operation of said brake operating member, an accumulator for storing a second hydraulic pressure, a wheel brake cylinder operated selectively by said first and second hydraulic pressures to apply a brake to a wheel of said vehicle, and a control valve through which said first and second hydraulic pressures are selectively applied to said wheel brake cylinder, said hydraulically-operated brake system comprising:

• a fluid leakage detection means for detecting leakage of fluid from said accumulator, and for generating an output signal indicative thereof;
• and
• a valve reciprocating means responsive to said output signal, for removing a cause of leakage flow from said accumulator by initiating at least one reciprocating movement of a valving member of said control valve.

A hydraulically-operated system including an accumulator for storing a fluid under pressure, a pressurizing means for raising a pressure of said fluid stored in said accumulator, and an actuator operated by the fluid supplied from said accumulator, said hydraulically-operated system comprising:

• a fluid leakage detecting means for detecting a leakage of the fluid from said accumulator by detecting whether an operation time of said pressurizing means is longer than a first predetermined reference time which is sufficient for said pressurizing means to raise the pressure in said accumulator to a predetermined normal level if there is an absence of leakage of the fluid from said accumulator, whether a non-operation time of said pressurizing means is shorter than a second predetermined reference time which is determined such that the pressure of the fluid in said accumulator will not be abnormally lowered during said second predetermined reference time if there is an absence of leakage in said fluid from said accumulator, and whether there is an abnormal drop after a third predetermined time commencing after an action to remove a cause of leakage flow is performed, said third predetermined time being sufficient for a rise of the pressure of the fluid in said accumulator to said predetermined normal level.

A hydraulically-operated system including an accumulator for storing a fluid under pressure, a pressurizing means for raising a pressure of said fluid stored in said accumulator, and an actuator operated by said fluid supplied from said accumulator, said hydraulically-operated system comprising:

• a fluid leakage detecting means for detecting leakage of the fluid from said accumulator, said fluid leakage detecting means includes a pressure drop detecting means for detecting an abnormal drop of the pressure of the fluid in said accumulator below a predetermined lower limit, said fluid leakage detecting means detects said leakage of the fluid when said pressure drop detecting means detects said abnormal drop after a predetermined time that an action to remove a cause of leakage flow is performed, said predetermined time being sufficient for a rise of the pressure of the fluid in said accumulator to a predetermined normal level.