Device and method for controlling the state of an energy accumulator

1. A method of checking a state of an accumulator with energy reserve that is connected to a fluid system, the method comprising;

pressurizing the fluid system to an operating pressure P F ;

maintaining the fluid system at the operating pressure P F for at least a period of time τ to ensure a stabilization of the fluid system;

stopping the pressurisation of the fluid system after an expiration of the at least time period τ;

detecting that a pressure value of the fluid system falls from the operating pressure P F to a predetermined pressure value P 1 ;

initiating a checking process to determine a time Δt taken by the system to change from the detected predetermined pressure P 1 to a predetermined pressure P 2 , wherein P 2 <P 1 <P F ;

comparing the time Δt with a predetermined reference time T ref wherein the state of the accumulator is determined by a result of the comparison of time Δt with predetermined reference time T ref .

2. A method according to claim 1 , further comprising comparing the time Δt with the predetermined reference time T ref using a real-time processing unit, the reference time T ref being stored in a non-volatile memory of the processing unit.

3. A method according to claim 2 , further comprising, after comparing the time Δt with the predetermined reference time T ref , sending a state signal from the processing to a display unit to indicate the status of the accumulator.

4. A method according to claim 1 , further comprising that the reference time T ref is pre-determined using a reference accumulator.

5. A method according to claim 1 , further comprising that the pre-determined pressure value P 2 is a pre-charging pressure of the accumulator.

6. A method according to claim 1 , further comprising that the pre-determined pressure value P 1 is 1/10 P F <P 1 <P F .

7. A method according to claim 1 , further comprising that the fluid is air.

8. A method according to claim 1 , further comprising that the fluid is a liquid.

9. The method of claim 1 further comprising that the state of the accumulator indicates a need for maintenance when the time Δt is less than the predetermined reference time T ref .

10. The method of claim 1 further comprising that the state of the accumulator indicates the accumulator is properly charged when the time Δt is greater than the predetermined reference time T ref .

11. The method of claim 1 wherein the time Δt is a pressure discharge time for the fluid system to go from predetermined pressure P 1 to predetermined pressure P 2 .

12. A device for determining a state of an accumulator with energy reserve, the accumulator connected to a high-pressure line (HP) of a fluid system, the fluid system comprising at least one pump for pressuring the system, the device comprising:

a real-time processing unit having a non-volatile memory,

at least one pressure detector for measuring a pressure of a fluid in the high-pressure line (HP), the detector configured to send to the processing unit a measurement signal representing a pressure measured by the detector,

wherein the processing unit comprises electronic means for measuring an interval of time Δt separating two predetermined pressure measurements P 1 and P 2 , and means for comparing the time interval Δt with a reference value stored in the non-volatile memory in order to determine the state of the accumulator.

13. A device according to claim 12 , wherein the pressure detector measures pressures ranging up to 420 bar.

14. A device according to claim 12 , wherein the real-time unit is configured to send a signal identifying a state of the accumulator to a display means.

15. An aircraft comprising at least one accumulator with energy reserve the aircraft comprising at least one device according to claim 12 .