System and method for measuring liquid discharge and internal leakage rate of pressure accumulator of aircraft hydraulic system

Abstract

The invention relates to a system and a method for measuring liquid drainage and internal leakage of a pressure accumulator of an aircraft hydraulic system. The system comprises a liquid discharge and leakage measuring device and a control unit connected with the liquid discharge and leakage measuring device, the liquid discharging and leakage measuring device comprises an oil liquid detector arranged near the upper end of the liquid discharging and leakage measuring device and used for detecting the internal leakage oil liquid amount of the pressure accumulator of the aircraft hydraulic system. The liquid discharging and leakage measuring device further comprises an automatic liquid discharging valve arranged in the liquid discharging and leakage measuring device and used for discharging internal leaked oil. The control unit is configured to judge whether the internal leakage oil quantity is higher than or equal to an oil quantity warning value or not; judging whether the system pressure is lower than or equal to a preset pressure value; if the control unit receives the internal leakage signal and the system pressure relief signal, the control unit sends an opening command to control the automatic drain valve to be opened; and if the internal leakage oil quantity is lower than the oil quantity warning value, the oil detector relieves the internal leakage signal and sends the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve to be closed.

Description

Technical Field

[0001] The invention relates to the field of civil transport aircraft design, and in particular to an accumulator discharge and internal leakage measurement system and method for an aircraft hydraulic system. Background Art

[0002] Piston accumulators are often used in aircraft hydraulic systems to maintain the boost pressure for the self-pressurizing hydraulic oil tank, provide emergency hydraulic energy to the system in a short period of time, and buffer and absorb pressure shocks.

[0003] The piston accumulator stores gas at one end and is filled with hydraulic oil and connected to the hydraulic oil tank at the other end. The hydraulic pressure pushes the piston to compress the gas, which can store hydraulic energy in the gas. When the hydraulic pressure drops, the gas pressure can push the piston to release energy to maintain the boost pressure of the hydraulic oil tank for a short time. In the above process, in order to ensure the smooth movement of the piston in the housing, a certain gap needs to be maintained between the two, otherwise the piston and the housing will be in close contact, and the friction will be too large to move. Due to the existence of the matching gap between the piston and the housing, when the accumulator is working, there will be a physical phenomenon that the hydraulic oil flows from the liquid side of the accumulator to the gas side, and the gas flows from the gas side of the accumulator to the liquid side. This flow occurs inside the accumulator and is called internal leakage. In addition, the contact surface between the piston and the housing is damaged, the piston and the housing are not tightly fitted, and the large matching gap between the piston and the housing caused by poor manufacturing and assembly quality may cause the internal leakage of the accumulator to exceed the standard. In summary, the internal leakage of the accumulator occurs inside, which is not easy to observe and cannot be avoided. Once the internal leakage exceeds the standard, the ability of the accumulator to maintain the boost pressure of the hydraulic oil tank will decrease.

[0004] In the prior art, the oil end of the piston accumulator of the hydraulic system is generally installed higher than the gas end so that the gas leaking from the gas end to the liquid end of the accumulator can be discharged. However, when the hydraulic oil leaks from the liquid end to the gas end, the hydraulic oil tends to accumulate at the gas end joint under the action of gravity, blocking the joint and polluting the inflation line. The inflation line is relatively long, and the internal leaked oil adheres to the inflation line, which is not easy to clean or collect, and it is even more difficult to measure the leakage amount and reflect the sealing condition of the accumulator piston, which brings great inconvenience to ground maintenance, thus leading to the invention.

[0005] The hydraulic system of B777 / 787 aircraft uses a piston accumulator to maintain the boost pressure of the self-pressurized hydraulic oil tank. When installed, the accumulator's gas end faces downward and the liquid end faces upward, and there is a gas charging pipeline between the accumulator and the gas charging valve and pressure gauge. This method is convenient for the gas leakage from the gas end to the liquid end to be discharged, but the hydraulic oil leaking from the liquid end to the gas end is easy to accumulate in the gas end joint under the action of gravity, blocking the joint and polluting the gas charging pipeline.

[0006] The hydraulic system of the A319 / 320 / 321 / 330 aircraft uses a bladder accumulator to maintain the boost pressure for the self-pressurizing hydraulic oil tank. Its advantage is that the internal gas is completely isolated from the hydraulic oil, eliminating the problem of internal oil leakage. On the aircraft, it can be installed with the inflation end facing down or up. However, the airbag is usually difficult to withstand excessive pressure, and its quality and life are easily affected by processing technology, assembly method, fluid corrosion, and temperature changes. In addition, even if the piston accumulator has internal leakage, it will only slowly reduce the pressure retention performance. Once the bladder accumulator ruptures, it will cause the accumulator to fail completely. Therefore, the reliability and life of the bladder accumulator are not as good as those of the piston accumulator.

[0007] As can be seen from the above, in the hydraulic system of civil aircraft in the prior art, each hydraulic subsystem uses at least one accumulator to maintain the boost pressure for the self-pressurized hydraulic oil tank, and the piston accumulator is installed in a way that the oil end is higher than the inflation end, so that the gas leaked from the gas end to the liquid end can be discharged. If the oil end is lower than the inflation end, the internal leakage gas will always remain on the oil side of the accumulator, which will reduce the pressure holding performance of the accumulator. However, the installation scheme of the prior art is difficult to avoid the internal leakage hydraulic oil clogging the joints, polluting the inflation pipeline and inflation equipment, and it is not convenient to discharge the internal leakage hydraulic oil, and it is not convenient to measure the internal leakage amount.

[0008] In addition, in the entire hydraulic field, for leakage detection, if flow sensors are used, it is difficult to measure or the measurement accuracy is very low in the case of micro or small flow, which cannot meet the requirements of large measuring range and high measurement accuracy, and the detection is cumbersome and time-consuming. If ultrasonic measurement is used, it will cause a large increase in system weight, reduce reliability and safety, and increase costs. Summary of the invention

[0009] An object of the present invention is to provide a system and method for discharging and measuring internal leakage of an accumulator of an aircraft hydraulic system, which can overcome the deficiencies of the prior art and realize internal leakage oil detection, automatic discharging and internal leakage measurement of an accumulator of an aircraft hydraulic system.

[0010] The above objects of the present invention are achieved by a system for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system, the system comprising a discharge and leakage measuring device and a control unit, wherein the discharge and leakage measuring device is installed to the accumulator gas end of the accumulator of the aircraft hydraulic system, and the control unit is connected to the discharge and leakage measuring device;

[0011] The drainage and leakage measuring device includes an oil detector disposed near its upper end for detecting the amount of internal leakage oil in the accumulator of the aircraft hydraulic system;

[0012] The drainage and leakage measuring device further comprises an automatic drainage valve disposed in the drainage and leakage measuring device for discharging internal leakage oil;

[0013] The control unit is configured to:

[0014] Determine whether the internal leakage oil volume is higher than or equal to the oil volume warning value. If the internal leakage oil volume is higher than or equal to the oil volume warning value, the oil detector sends an internal leakage signal to the control unit;

[0015] Determine whether the system pressure is lower than or equal to a preset pressure value, wherein the system pressure is measured by a pressure oil filter pressure sensor, and if the system pressure is lower than or equal to the preset pressure value, the pressure oil filter pressure sensor sends a system pressure relief signal to the control unit;

[0016] If the control unit has received an internal leakage signal and a system pressure relief signal, the control unit sends an opening command to control the automatic drain valve to open and drain the internal leakage oil;

[0017] If the internal leakage oil volume is lower than the oil volume warning value, the oil detector releases the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve to close.

[0018] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: it can realize the internal leakage oil detection, automatic drainage and internal leakage measurement of the air end of the aircraft hydraulic system accumulator, with high reliability and easy maintenance.

[0019] Preferably, the drainage and leakage measuring device also includes an oil storage measuring cylinder and a pressure relief valve, wherein the oil storage measuring cylinder is arranged at the lower end of the drainage and leakage measuring device, and is used to temporarily store the internal leakage oil and indicate the amount of internal leakage oil discharged, and the pressure relief valve is arranged in the drainage and leakage measuring device and is located upstream of the oil storage measuring cylinder, and is used to reduce the pressure of the discharged gas and the internal leakage hydraulic oil.

[0020] According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: it can discharge the internal leakage oil in a timely manner, making it convenient for ground maintenance personnel to read the internal leakage oil amount.

[0021] Preferably, the drainage and leakage measuring device also includes an accumulator gas end connector, an air charging line connector, and an R-type three-way housing, wherein the accumulator gas end connector is connected to the accumulator gas end of the aircraft hydraulic system accumulator, and the air charging line connector is connected to the air charging line used for the aircraft hydraulic system accumulator. The R-type three-way housing is arranged at the upper end of the drainage and leakage measuring device and is used to respectively connect the accumulator gas end connector, the air charging line connector and the automatic drainage valve, and the accumulator gas end connector and the air charging line connector form an acute angle of 30 to 60 degrees in azimuth.

[0022] According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: the present invention designs the charging pipe joint and the accumulator gas end joint to be at an acute angle of 30 to 60 degrees in orientation, which greatly reduces the possibility of the leaked oil in the accumulator entering the charging pipe from a physical point of view; the anti-pollution design greatly reduces the possibility of the charging pipe being contaminated by the internal leakage oil, facilitates the charging and maintenance of the accumulator, reduces the maintenance cost, and improves the reliability of the hydraulic system.

[0023] Preferably, the drainage and leakage measuring device further comprises a valve actuator, wherein the valve actuator is connected to the control unit, and the control unit sends an opening or closing command to the valve actuator to control the automatic drainage valve to open or close.

[0024] According to the above technical scheme, the aircraft hydraulic system accumulator draining and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: it is convenient to open or close the automatic drain valve, so that the automatic draining of the leaked oil at the air end of the aircraft hydraulic system accumulator is more timely.

[0025] Preferably, the oil volume warning value is the product of an upper limit of an internal leakage index of the accumulator under normal operation and an average flight time of the aircraft.

[0026] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: through the appropriate oil volume warning value, the automatic drainage of the leaking oil at the air end of the aircraft hydraulic system accumulator can be better achieved.

[0027] Preferably, the predetermined value of the system pressure is 50 psi.

[0028] According to the above technical scheme, the aircraft hydraulic system accumulator draining and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: through a suitable system pressure preset value, the automatic draining of the internal leakage oil at the gas end of the aircraft hydraulic system accumulator can be better realized, ensuring that the internal leakage oil is only discharged after the system is depressurized.

[0029] The above object of the present invention is also achieved by a method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system, the method comprising:

[0030] An oil detector is used to detect the amount of internal oil leakage of the aircraft hydraulic system accumulator, wherein the oil detector is arranged near the upper end of the discharge and leakage measuring device, and the discharge and leakage measuring device is installed to the accumulator gas end of the aircraft hydraulic system accumulator;

[0031] Determine whether the internal leakage oil volume is higher than or equal to the oil volume warning value. If the internal leakage oil volume is higher than or equal to the oil volume warning value, the oil detector sends an internal leakage signal to the control unit;

[0032] Determine whether the system pressure is lower than or equal to a preset pressure value, wherein the system pressure is measured by a pressure oil filter pressure sensor, and if the system pressure is lower than or equal to the preset pressure value, the pressure oil filter pressure sensor sends a system pressure relief signal to the control unit;

[0033] If the control unit has received an internal leakage signal and a system pressure relief signal, the control unit sends an opening command to control the automatic drain valve to open and drain the internal leaked oil, wherein the automatic drain valve is arranged in the drain and leakage measuring device;

[0034] If the internal leakage oil volume is lower than the oil volume warning value, the oil detector releases the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve to close.

[0035] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: it can realize the internal leakage oil detection, automatic drainage and internal leakage measurement of the air end of the aircraft hydraulic system accumulator, with high reliability and easy maintenance.

[0036] Preferably, after the automatic drain valve is opened and the internal leakage oil is discharged, the pressure relief valve is opened to discharge the oil into the oil storage measuring cylinder, and the amount of internal leakage oil in the oil storage measuring cylinder is read out, wherein the oil storage measuring cylinder is arranged at the lower end of the drain and leakage measuring device, and the pressure relief valve is arranged in the drain and leakage measuring device and is located upstream of the oil storage measuring cylinder.

[0037] According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: the internal leakage oil can be discharged in a timely manner, making it convenient for ground maintenance personnel to read the internal leakage oil amount.

[0038] Preferably, the drainage and leakage measuring device also includes an accumulator gas end connector, an air charging line connector, and an R-type three-way housing, wherein the accumulator gas end connector is connected to the accumulator gas end of the aircraft hydraulic system accumulator, and the air charging line connector is connected to the air charging line used for the aircraft hydraulic system accumulator. The R-type three-way housing is arranged at the upper end of the drainage and leakage measuring device and is used to respectively connect the accumulator gas end connector, the air charging line connector and the automatic drainage valve, and the accumulator gas end connector and the air charging line connector form an acute angle of 30 to 60 degrees in azimuth.

[0039] According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: the present invention designs the charging pipeline joint and the accumulator gas end joint to be an acute angle of 30 degrees to 60 degrees in orientation, which greatly reduces the possibility of the leaked oil in the accumulator entering the charging pipeline physically; the anti-pollution design greatly reduces the possibility of the charging pipeline being contaminated by the internal leakage oil, facilitates the charging and maintenance of the accumulator, reduces the maintenance cost, and improves the reliability of the hydraulic system.

[0040] Preferably, the drainage and leakage measuring device further comprises a valve actuator, wherein the valve actuator is connected to the control unit, and the control unit sends an opening or closing command to the valve actuator to control the automatic drainage valve to open or close.

[0041] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: it is easy to open or close the automatic drain valve, so that the automatic drainage of the leaked oil at the air end of the aircraft hydraulic system accumulator is more timely.

[0042] Preferably, the oil volume warning value is the product of an upper limit of an internal leakage index of the accumulator under normal operation and an average flight time of the aircraft.

[0043] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: through the appropriate oil volume warning value, the automatic drainage of the leaking oil at the air end of the aircraft hydraulic system accumulator can be better achieved.

[0044] Preferably, the predetermined value of the system pressure is 50 psi.

[0045] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: through a suitable system pressure preset value, the automatic drainage of the internal leakage oil at the gas end of the aircraft hydraulic system accumulator can be better realized, ensuring that the internal leakage oil is discharged only after the system is depressurized. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The present invention is a schematic diagram of an accumulator discharge and internal leakage measurement system for an aircraft hydraulic system according to an embodiment of the present invention.

[0047] Figure 2 The present invention is a schematic structural diagram of a discharge and leakage measuring device in an accumulator discharge and internal leakage measuring system of an aircraft hydraulic system according to an embodiment of the present invention.

[0048] Figure 3 The present invention is a flowchart of a method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system according to an embodiment of the present invention.

[0049] Reference numerals list

[0050] 11: Oil detector;

[0051] 12: Automatic drain valve;

[0052] 13: Oil storage measuring cylinder;

[0053] 14: Pressure relief valve;

[0054] 15: Accumulator gas end connector;

[0055] 16: Inflatable pipe connector;

[0056] 17: R-type three-way shell;

[0057] 18: Valve actuator. DETAILED DESCRIPTION

[0058] The specific embodiments of the present invention will be described below. It should be noted that in the specific description of these embodiments, in order to be concise and clear, this specification cannot provide a detailed description of all the features of the actual embodiments. It should be understood that in the actual implementation of any embodiment, just as in the process of any engineering project or design project, in order to achieve the specific goals of the developer and to meet system-related or business-related restrictions, various specific decisions are often made, and this will also change from one embodiment to another. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the content disclosed by the present invention, some changes in design, manufacturing or production based on the technical content disclosed in this disclosure are just conventional technical means, and should not be understood as insufficient content of this disclosure.

[0059] Unless otherwise defined, the technical or scientific terms used in the claims and the specification shall have the usual meaning understood by persons with ordinary skills in the technical field to which the invention belongs. The words "first", "second" and similar words used in the patent application specification and the claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "One" or "one" and other similar words do not indicate a quantitative limitation, but indicate the existence of at least one. "Include" or "comprises" and other similar words mean that the elements or objects appearing before "include" or "comprises" include the elements or objects listed after "include" or "comprises" and their equivalent elements, and do not exclude other elements or objects. "Connected" or "connected" and other similar words are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0060] In the following description, in order to clearly show the structure and working mode of the present invention, many directional words will be used for description, but the words "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", "down", etc. should be understood as convenient terms and should not be understood as restrictive terms.

[0061] Figure 1 The present invention is a schematic diagram of an accumulator discharge and internal leakage measurement system for an aircraft hydraulic system according to an embodiment of the present invention. Figure 2 The present invention is a schematic structural diagram of a discharge and leakage measuring device in an accumulator discharge and internal leakage measuring system of an aircraft hydraulic system according to an embodiment of the present invention. Figure 3 The present invention is a flowchart of a method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system according to an embodiment of the present invention.

[0062] like Figure 1 As shown in the figure, taking the most basic hydraulic system composed of a hydraulic oil tank, a hydraulic pump, a pressure oil filter, and a hydraulic user as an example, a self-pressurizing priority valve and a piston accumulator liquid end are connected to the oil tank boosting oil circuit (the piston accumulator liquid end is basically installed upward and can be tilted appropriately). When the inlet pressure decreases, the self-pressurizing priority valve is closed, and the hydraulic energy stored in the accumulator gas end drives the piston to move to maintain the boosting oil circuit pressure for a short time. The piston accumulator gas end is connected to the charging pressure gauge assembly through a section of charging pipeline, and the charging pressure gauge assembly can inflate the accumulator during ground maintenance. The accumulator gas end is also connected to a drainage and leakage measurement device, and the drainage and leakage measurement device and the control unit transmit signals to each other to perform drainage and internal leakage measurement operations.

[0063] like Figures 1 to 3As shown, according to one embodiment of the present invention, a system for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system comprises a discharge and leakage measuring device and a control unit, wherein the discharge and leakage measuring device is installed to an accumulator gas end of an accumulator of an aircraft hydraulic system, and the control unit is connected to the discharge and leakage measuring device;

[0064] The discharge and leakage measuring device comprises an oil detector 11 arranged near its upper end for detecting the amount of internal leakage oil in the accumulator of the hydraulic system of the aircraft;

[0065] The drainage and leakage measuring device also includes an automatic drainage valve 12 arranged in the drainage and leakage measuring device, which is used to discharge the internal leakage oil;

[0066] The control unit is configured as:

[0067] Determine whether the internal leakage oil volume is higher than or equal to the oil volume warning value. If the internal leakage oil volume is higher than or equal to the oil volume warning value, the oil detector 11 sends an internal leakage signal to the control unit;

[0068] Determine whether the system pressure is lower than or equal to a preset pressure value, wherein the system pressure is measured by a pressure oil filter pressure sensor. If the system pressure is lower than or equal to the preset pressure value, the pressure oil filter pressure sensor sends a system pressure relief signal to the control unit;

[0069] If the control unit has received an internal leakage signal and a system pressure relief signal, the control unit sends an opening command to control the automatic drain valve 12 to open and drain the internal leakage oil;

[0070] If the internal leakage oil volume is lower than the oil volume warning value, the oil detector 11 releases the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve 12 to close.

[0071] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: it can realize the internal leakage oil detection, automatic drainage and internal leakage measurement of the air end of the aircraft hydraulic system accumulator, with high reliability and easy maintenance.

[0072] In some embodiments, Figures 1 to 3As shown, the discharge and leakage measuring device also includes an oil storage cylinder 13 and a pressure relief valve 14, wherein the oil storage cylinder 13 is arranged at the lower end of the discharge and leakage measuring device, and is used to temporarily store the internal leakage oil and indicate the amount of internal leakage oil discharged, and the pressure relief valve 14 is arranged in the discharge and leakage measuring device and is located upstream of the oil storage cylinder 13 (it should be noted that "upstream" here refers to the discharge direction), and is used to reduce the pressure of the discharged gas and the internal leakage hydraulic oil. According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: it can discharge the internal leakage oil in a timely manner, so that ground maintenance personnel can read the amount of internal leakage oil.

[0073] Preferably, the oil storage measuring cylinder 13 is made of transparent or translucent material, is detachable, and has scales on the cylinder body, and is used to temporarily store the internal leakage oil and indicate the amount of the internal leakage oil discharged.

[0074] Preferably, the pressure relief valve 14 is used to reduce the pressure of the exhaust gas and hydraulic oil, and the design of the two valves (automatic drain valve 12 and pressure relief valve 14) can reduce the loss of nitrogen during the draining process.

[0075] In some embodiments, Figure 1 to Figure 2 As shown, the discharge and leakage measuring device also includes an accumulator gas end connector 15, an air charging line connector 16, and an R-type three-way housing 17, wherein the accumulator gas end connector 15 is connected to the accumulator gas end of the aircraft hydraulic system accumulator, and the air charging line connector 16 is connected to the air charging line for the aircraft hydraulic system accumulator. The R-type three-way housing 17 is arranged at the upper end of the discharge and leakage measuring device, and is used to connect the accumulator gas end connector 15, the air charging line connector 16 and the automatic discharge valve 12 respectively, and the accumulator gas end connector 15 and the air charging line connector 16 form an acute angle of 30 to 60 degrees in orientation. That is to say, the extension direction of the accumulator gas end connector 15 is consistent with the extension direction of the main body of the R-type three-way housing 17, and the extension direction of the air charging line connector 16 is consistent with the extension direction of the branch of the R-type three-way housing 17, and relative to the main body of the R-type three-way housing 17, it extends obliquely upward, forming an acute angle of 30 to 60 degrees. According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: the present invention designs the charging pipe joint and the accumulator gas end joint to be at an acute angle of 30 to 60 degrees in orientation, which greatly reduces the possibility of the leaked oil in the accumulator entering the charging pipe from a physical point of view; the anti-pollution design greatly reduces the possibility of the charging pipe being contaminated by the internal leakage oil, facilitates the charging and maintenance of the accumulator, reduces the maintenance cost, and improves the reliability of the hydraulic system.

[0076] In some embodiments, Figure 1 to Figure 2As shown, the discharge and leakage measuring device further includes a valve actuator 18, which is connected to the control unit, and the control unit sends an opening or closing command to the valve actuator 18 to control the opening or closing of the automatic discharge valve 12. According to the above technical scheme, the aircraft hydraulic system accumulator discharge and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: it is convenient to open or close the automatic discharge valve, so that the automatic discharge of the leaked oil at the gas end of the aircraft hydraulic system accumulator is more timely.

[0077] Preferably, the automatic drain valve 12 can be a ball valve, a butterfly valve, a stop valve, etc. Preferably, the valve actuator 18 is an electric actuator.

[0078] In some embodiments, Figures 1 to 3 As shown, the oil volume warning value is the product of the internal leakage index upper limit of the accumulator under normal operation and the average flight time of the aircraft. According to the above technical solution, the aircraft hydraulic system accumulator drainage and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: through the appropriate oil volume warning value, the automatic drainage of the internal leakage oil at the gas end of the aircraft hydraulic system accumulator can be better realized.

[0079] In some embodiments, Figures 1 to 3 As shown, the preset value of the system pressure is 50psi. According to the above technical solution, the aircraft hydraulic system accumulator discharge and internal leakage measurement system of the present invention can achieve the following beneficial technical effects: through the appropriate preset value of the system pressure, the automatic discharge of the internal leakage oil at the gas end of the aircraft hydraulic system accumulator can be better realized, ensuring that the internal leakage oil is discharged only after the system is depressurized.

[0080] like Figures 1 to 3 As shown, according to one embodiment of the present invention, a method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system includes:

[0081] An oil detector 11 is used to detect the amount of internal oil leakage of the aircraft hydraulic system accumulator, wherein the oil detector 11 is arranged near the upper end of the discharge and leakage measuring device, and the discharge and leakage measuring device is installed to the accumulator gas end of the aircraft hydraulic system accumulator;

[0082] Determine whether the internal leakage oil volume is higher than or equal to the oil volume warning value. If the internal leakage oil volume is higher than or equal to the oil volume warning value, the oil detector 11 sends an internal leakage signal to the control unit;

[0083] Determine whether the system pressure is lower than or equal to a preset pressure value, wherein the system pressure is measured by a pressure oil filter pressure sensor. If the system pressure is lower than or equal to the preset pressure value, the pressure oil filter pressure sensor sends a system pressure relief signal to the control unit;

[0084] If the control unit has received the internal leakage signal and the system pressure relief signal, the control unit sends an opening command to control the automatic drain valve 12 to open and drain the internal leakage oil, wherein the automatic drain valve 12 is arranged in the drain and leakage measurement device;

[0085] If the internal leakage oil volume is lower than the oil volume warning value, the oil detector 11 releases the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve 12 to close.

[0086] According to the above technical scheme, the aircraft hydraulic system accumulator drainage and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: it can realize the internal leakage oil detection, automatic drainage and internal leakage measurement of the air end of the aircraft hydraulic system accumulator, with high reliability and easy maintenance.

[0087] In some embodiments, Figures 1 to 3 As shown, after the automatic drain valve 12 is opened and the internal leakage oil is discharged, for example, during ground maintenance, the pressure relief valve 14 is opened to discharge the oil to the oil storage measuring cylinder 13, and the amount of internal leakage oil in the oil storage measuring cylinder 13 is read, wherein the oil storage measuring cylinder 13 is arranged at the lower end of the drain and leakage measuring device, and the pressure relief valve 14 is arranged in the drain and leakage measuring device and is located upstream of the oil storage measuring cylinder 13. According to the above technical scheme, the aircraft hydraulic system accumulator drain and internal leakage measurement method of the present invention can achieve the following beneficial technical effects: the internal leakage oil can be discharged in time, which is convenient for ground maintenance personnel to read the amount of internal leakage oil.

[0088] Preferably, when the system is powered off, the automatic drain valve 12 automatically returns to the closed state.

[0089] The innovative features of the aircraft hydraulic system accumulator discharge and internal leakage measurement system and method of the present invention are mainly as follows:

[0090] (1) Automatic drainage of internal leakage in the piston accumulator of the hydraulic system. The present invention installs an automatic drain valve at the gas end of the accumulator, and sets an oil detector at the upper end of the automatic drain valve. When the amount of internal leakage oil exceeds the warning value, an internal leakage signal is sent to the control unit to monitor the internal leakage. After executing the logical judgment, the control unit can issue an open command to control the automatic drain valve to discharge the leaked oil at the upper end. This design can effectively discharge the leaked oil in the accumulator, so that the accumulator maintains a stable pressure holding performance, while reducing the contamination of nitrogen by hydraulic oil and solid impurities, reducing the possibility of solid pollutants further scratching the end surface of the cylinder piston, and improving the safety and reliability of the hydraulic system.

[0091] (2) Internal leakage measurement of piston accumulators in hydraulic systems. On the one hand, an oil detector is installed at the top of the automatic drain valve. When the oil volume exceeds the warning value, an internal leakage signal is sent to the control unit to monitor the internal leakage volume. On the other hand, an oil storage cylinder is designed at the tail of the automatic drain valve. It is used to store the internal leakage oil for a short time in ground maintenance scenarios and manually measure the amount of discharged oil. This design enables ground maintenance personnel to understand the piston dynamic sealing performance of the accumulator and the pressure holding capacity of the accumulator, which is beneficial to the charging and maintenance of the accumulator.

[0092] (3) Anti-pollution design for the accumulator charging pipeline of the hydraulic system. The present invention designs the charging pipeline and the accumulator gas end joint to be at an acute angle of 30 to 60 degrees in terms of orientation, which greatly reduces the possibility of leaked oil from the accumulator entering the charging pipeline physically. The anti-pollution design greatly reduces the possibility of the charging pipeline being contaminated by leaked oil, facilitates the charging and maintenance of the accumulator, reduces maintenance costs, and improves the reliability of the hydraulic system.

[0093] The above describes the specific embodiments of the present invention, but those skilled in the art will understand that the above specific embodiments do not constitute a limitation of the present invention. Those skilled in the art can make various modifications based on the above disclosure without exceeding the scope of the present invention.

Claims

1. An aircraft hydraulic system accumulator discharge and internal leakage measurement system, the aircraft hydraulic system accumulator discharge and internal leakage measurement system comprising a discharge and leakage measurement device and a control unit, wherein: The drainage and leakage measuring device is mounted to the accumulator gas end of the aircraft hydraulic system accumulator, and the control unit is connected to the drainage and leakage measuring device; The drainage and leakage measuring device includes an oil detector disposed near its upper end for detecting the amount of internal leakage oil in the accumulator of the aircraft hydraulic system; The drainage and leakage measuring device further comprises an automatic drainage valve disposed in the drainage and leakage measuring device for discharging internal leakage oil; The control unit is configured to: Determine whether the internal leakage oil volume is higher than or equal to the oil volume warning value. If the internal leakage oil volume is higher than or equal to the oil volume warning value, the oil detector sends an internal leakage signal to the control unit; Determine whether the system pressure is lower than or equal to a preset pressure value, wherein the system pressure is measured by a pressure oil filter pressure sensor, and if the system pressure is lower than or equal to the preset pressure value, the pressure oil filter pressure sensor sends a system pressure relief signal to the control unit; If the control unit has received an internal leakage signal and a system pressure relief signal, the control unit sends an opening command to control the automatic drain valve to open and drain the internal leakage oil; If the internal leakage oil volume is lower than the oil volume warning value, the oil detector releases the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve to close.

2. The aircraft hydraulic system accumulator discharge and internal leakage measurement system according to claim 1, characterized in that: The discharge and leakage measuring device also includes an oil storage measuring cylinder and a pressure relief valve, wherein the oil storage measuring cylinder is arranged at the lower end of the discharge and leakage measuring device, and is used to temporarily store the internal leakage oil and indicate the amount of internal leakage oil discharged; the pressure relief valve is arranged in the discharge and leakage measuring device and is located upstream of the oil storage measuring cylinder, and is used to reduce the pressure of the discharged gas and the internal leakage hydraulic oil.

3. The aircraft hydraulic system accumulator discharge and internal leakage measurement system according to claim 1, characterized in that: The discharge and leakage measuring device also includes an accumulator gas end joint, an air charging pipeline joint, and an R-type three-way housing, wherein the accumulator gas end joint is connected to the accumulator gas end of the aircraft hydraulic system accumulator, and the air charging pipeline joint is connected to the air charging pipeline used for the aircraft hydraulic system accumulator. The R-type three-way housing is arranged at the upper end of the discharge and leakage measuring device, and is used to respectively connect the accumulator gas end joint, the air charging pipeline joint and the automatic discharge valve, and the accumulator gas end joint and the air charging pipeline joint form an acute angle of 30 to 60 degrees in azimuth.

4. The aircraft hydraulic system accumulator discharge and internal leakage measurement system according to claim 1, characterized in that: The drainage and leakage measuring device further comprises a valve actuator, which is connected to the control unit. The control unit sends an opening or closing command to the valve actuator to control the automatic drainage valve to open or close.

5. The aircraft hydraulic system accumulator discharge and internal leakage measurement system according to claim 1, characterized in that: The oil volume warning value is the product of the upper limit of the internal leakage index of the accumulator under normal operation and the average flight time of the aircraft.

6. The aircraft hydraulic system accumulator discharge and internal leakage measurement system according to claim 1, characterized in that: The preset pressure value is 50 psi.

7. A method for measuring the discharge and internal leakage of an accumulator in an aircraft hydraulic system, comprising: An oil detector is used to detect the amount of internal oil leakage of the aircraft hydraulic system accumulator, wherein the oil detector is arranged near the upper end of the discharge and leakage measuring device, and the discharge and leakage measuring device is installed to the accumulator gas end of the aircraft hydraulic system accumulator; Determine whether the internal leakage oil volume is higher than or equal to the oil volume warning value. If the internal leakage oil volume is higher than or equal to the oil volume warning value, the oil detector sends an internal leakage signal to the control unit; Determine whether the system pressure is lower than or equal to a preset pressure value, wherein the system pressure is measured by a pressure oil filter pressure sensor, and if the system pressure is lower than or equal to the preset pressure value, the pressure oil filter pressure sensor sends a system pressure relief signal to the control unit; If the control unit has received an internal leakage signal and a system pressure relief signal, the control unit sends an opening command to control the automatic drain valve to open and drain the internal leaked oil, wherein the automatic drain valve is arranged in the drain and leakage measuring device; If the internal leakage oil volume is lower than the oil volume warning value, the oil detector releases the internal leakage signal to the control unit, and the control unit sends a closing command to control the automatic drain valve to close.

8. The method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system according to claim 7, characterized in that: After the automatic drain valve is opened and the internal leakage oil is discharged, the pressure relief valve is opened to discharge the oil into the oil storage measuring cylinder, and the amount of internal leakage oil in the oil storage measuring cylinder is read out, wherein the oil storage measuring cylinder is arranged at the lower end of the drain and leakage measuring device, and the pressure relief valve is arranged in the drain and leakage measuring device and is located upstream of the oil storage measuring cylinder.

9. The method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system according to claim 7, characterized in that: The discharge and leakage measuring device also includes an accumulator gas end joint, an air charging pipeline joint, and an R-type three-way housing, wherein the accumulator gas end joint is connected to the accumulator gas end of the aircraft hydraulic system accumulator, and the air charging pipeline joint is connected to the air charging pipeline used for the aircraft hydraulic system accumulator. The R-type three-way housing is arranged at the upper end of the discharge and leakage measuring device, and is used to respectively connect the accumulator gas end joint, the air charging pipeline joint and the automatic discharge valve, and the accumulator gas end joint and the air charging pipeline joint form an acute angle of 30 to 60 degrees in azimuth.

10. The method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system according to claim 7, characterized in that: The drainage and leakage measuring device further comprises a valve actuator, which is connected to the control unit. The control unit sends an opening or closing command to the valve actuator to control the automatic drainage valve to open or close.

11. The method for measuring the discharge and internal leakage of an accumulator of an aircraft hydraulic system according to claim 7, characterized in that: The oil volume warning value is the product of the upper limit of the internal leakage index of the accumulator under normal operation and the average flight time of the aircraft.

12. The aircraft hydraulic system accumulator discharge and internal leakage measurement method according to claim 7, characterized in that: The preset pressure value is 50 psi.

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