Oil quantity indicator tester

Abstract

This utility model relates to the field of aviation measurement tool technology, specifically a fuel level signal tester, including a bracket, a simulated fuel tank, an upper cover, a lower cover, a nitrogen cylinder, a first pressure gauge, a dual-way valve, a three-way connector, a second pressure gauge, a high-pressure hose, and a multimeter. The simulated fuel tank is fixed on the bracket, the fuel level signal to be tested is mounted on the upper cover, and a valve is provided at the lower end of the lower cover. The upper and lower covers are mounted on the simulated fuel tank, forming a sealed cavity with the simulated fuel tank. The outlet of the nitrogen cylinder is connected to the inlet of the dual-way valve via a high-pressure hose, and the outlet of the dual-way valve is connected to the second pressure gauge and the valve at the lower end of the lower cover via a high-pressure hose. The nitrogen cylinder is pre-filled with high-pressure nitrogen. The multimeter is externally mounted, and its positive and negative terminals are connected to the first and second pins of the fuel level signal to be tested. This utility model can simulate the working environment of the fuel level signal on the ground, thereby avoiding on-air testing, resulting in low testing cost and short cycle.

Description

Technical Field

[0001] This utility model relates to the field of aviation testing tools, specifically a fuel level signal tester. Background Technology

[0002] Fuel level indicators mainly include full fuel indicator, low fuel indicator, fuel level sensor indicator, and emergency low fuel indicator. All of these fuel level indicators consist of an internal magnetic float and a signal sensor. They are components in the aircraft fuel system used to provide the pilot with the status of the aircraft's total fuel consumption. The proper functioning of fuel level indicators is crucial for flight safety. They must be tested during scheduled aircraft maintenance or repairs before being installed on the aircraft.

[0003] The full fuel indicator is used to send a signal when the auxiliary fuel tanks in the fuselage and wings are full during pressurized refueling. Its working principle is as follows: when pressurized refueling is carried out, the magnetic float rises with the fuel level. When it reaches the specified height (i.e., the distance from the mounting surface of the magnetic float to the fuel level is 90mm±5mm), the reed switch inside the magnetic float is magnetized and attracted by the magnet. The signal sensor of the full fuel indicator is activated, and the full fuel indicator light illuminates. When the fuel level continues to rise, the signal sensor remains constantly activated.

[0004] The fuel level indicator is used to issue a fuel level warning signal when the remaining fuel in the aircraft fuel tank is 500L. Its working principle is as follows: the magnetic float descends with the fuel level. When the fuel level reaches a specified height (i.e., the distance from the mounting surface of the magnetic float to the fuel level is 255mm±8mm), the reed switch inside the magnetic float is magnetized and attracted, the signal sensor of the fuel level indicator is turned on, and the fuel level warning light is illuminated; when the fuel level continues to descend, the signal sensor remains constantly on.

[0005] The fuel level sensor is used to indicate the remaining fuel level of an aircraft. Its working principle is as follows: the magnetic float floats up and down with the change of fuel level. When the fuel level reaches a specified height (i.e., the distance from the mounting surface of the magnetic float to the fuel level is 520mm ± 5mm), the reed switch inside the magnetic float is magnetized and attracted, and the signal sensor of the fuel level sensor is turned on. The hysteresis zone of the signal sensor of the fuel level sensor is 2.5mm to 10mm. The hysteresis zone refers to the difference between the distance from the mounting surface of the magnetic float to the fuel level when the magnetic float is turned on (or off) when it moves upward and the distance when the magnetic float is turned off (or on) when it moves downward.

[0006] The emergency low fuel indicator is used to issue an emergency low fuel warning signal when the remaining fuel in the aircraft fuel tank is 500L. Its working principle is as follows: the magnetic float descends with the fuel level. When the fuel level reaches the specified height (i.e., the distance from the mounting surface of the magnetic float to the fuel level is 440mm±5mm), the reed switch inside the magnetic float is magnetized and attracted, the signal sensor of the emergency low fuel indicator is activated, and the emergency low fuel warning light illuminates; when the fuel level continues to descend, the signal sensor remains constantly activated.

[0007] Currently, the maintenance depot lacks dedicated tooling for testing the fuel level indicator on a certain type of aircraft. To ensure product performance, the only current method is to test it in the actual fuel environment on board. This requires installing the untested indicator on the aircraft, refueling it for a certain period, and then releasing all the fuel. Only during this process can the airtightness and connection altitude of the indicator be tested to determine if it is functioning correctly. This testing process is time-consuming and resource-intensive. If the indicator fails the on-board test, it must be disassembled, repaired, and the test repeated, increasing the aircraft's maintenance cycle and consuming significant resources due to repeated disassembly and reinstallation. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, this invention provides a fuel level indicator tester for testing the fuel level indicator of a certain type of aircraft. This invention uses a simulated fuel tank and a replaceable top cover to fix the fuel level indicator to be tested onto the top cover. This allows for testing on the ground, simulating the aircraft's operating environment, thus avoiding on-board testing and repeated disassembly and reassembly. The testing cost is low and the cycle is short, facilitating rapid aircraft maintenance and readiness for flight.

[0009] The technical solution of this utility model is:

[0010] An oil level signal tester includes a bracket, a simulated oil tank, an upper cover, a lower cover, a nitrogen cylinder, a first pressure gauge, a dual-way valve, a three-way connector, a second pressure gauge, a high-pressure hose, and a three-way meter.

[0011] The simulated fuel tank is fixedly mounted on the bracket by clamps; the upper end of the upper cover has an inclined mounting surface for fixing the fuel level signal to be tested, simulating the installation of the fuel level signal on the aircraft; the lower end of the lower cover has a valve for simulating the intake and exhaust of fuel in the fuel tank; the upper cover is detachably and sealingly mounted on the top of the simulated fuel tank, and the lower cover is fixedly and sealingly mounted on the bottom of the simulated fuel tank; the upper and lower covers and the simulated fuel tank form a sealed cavity for simulating the fuel tank of the aircraft fuel system; the outer side of the simulated fuel tank has a scale to display the height of the center point of the upper cover mounting surface from the aviation kerosene level;

[0012] The nitrogen cylinder is pre-filled with high-pressure nitrogen to simulate the high-pressure gas source on the machine and to test the airtightness of the oil quantity signal device after it is installed in place; a first pressure gauge is provided at the mouth of the nitrogen cylinder to display the gas source pressure;

[0013] The dual-way valve is equipped with an air inlet, an air inlet control switch, an air outlet, and an air outlet control switch. The dual-way valve is also equipped with a vent switch. The air inlet control switch is used to control the opening and closing of the air inlet, the air outlet control switch is used to control the opening and closing of the air outlet, and the vent switch is used to exhaust air.

[0014] The nitrogen cylinder outlet is connected to the dual-way valve inlet via a high-pressure hose; the dual-way valve outlet is connected to the second pressure gauge and the lower valve of the lower cap via a high-pressure hose through a three-way connector.

[0015] The multimeter is externally mounted. Its positive and negative terminals are connected to pins one and two in the pin interface of the fuel level signal sensor to be measured. Pins one and two are connected to the signal sensor through the magnetic float of the fuel level signal sensor to be measured. When the multimeter is rotated to the buzzer setting, the beeping sound indicates that the signal sensor is activated.

[0016] Furthermore, the inclination angle of the inclined mounting surface at the upper end of the upper cover is selected according to the model of the fuel level indicator to be tested, and different upper covers are made according to different fuel level indicator specifications; the upper cover has an axially penetrating circular hole in the middle, and the diameter of the circular hole matches the diameter of the lower section of the fuel level indicator to be tested; the fuel level indicator to be tested is inserted into the upper cover through the circular hole from top to bottom, and the inclined mounting surface at the upper end of the upper cover is attached to the inclined surface at the upper end of the fuel level indicator to be tested and fastened with screws, and a rubber ring is provided between the upper cover and the fuel level indicator to be tested to ensure airtightness; after installation and fixing, the pin interface of the fuel level indicator to be tested is located on the outside of the inclined mounting surface at the upper end of the upper cover, which facilitates connection with the multimeter.

[0017] Furthermore, the upper cover is detachably mounted on top of the simulated oil tank via threads.

[0018] Furthermore, the simulated fuel tank is made of transparent resin material.

[0019] Furthermore, the method for using the aforementioned fuel quantity signal tester to test the fuel quantity signal is as follows:

[0020] Step 1: Select the matching top cover according to the model of the fuel level signal device to be tested, fix the fuel level signal device to be tested on the mounting surface of the top cover with screws, and install the top cover onto the simulated fuel tank.

[0021] Step 2: Open the air inlet control switch and the air outlet control switch, close the venting switch, open the lower valve of the lower cap, and control the gas in the nitrogen cylinder to enter the simulated oil tank through the dual-way valve and the three-way connector. When the pressure of the second pressure gauge reaches 0.3 MPa, close the air inlet control switch. Apply soap solution to the joint between the upper cap and the simulated oil tank, and between the upper cap and the oil quantity signal device to be tested. No bubbles should overflow from the joint. Visually observe the reading of the second pressure gauge and keep it for two minutes. If the reading does not change, it proves that the airtightness meets the requirements.

[0022] Step 3: Open the vent switch and vent until the pressure on the second pressure gauge is 0MPa. Then disconnect the pipeline connection from the tee connector to the valve at the bottom of the lower end of the cover and close the valve at the bottom of the lower end of the cover.

[0023] Step 4: Open the top cover of the simulated fuel tank, fill it with 2 / 3 aviation kerosene, and then reinstall the top cover on the simulated fuel tank; connect the positive and negative terminals of a multimeter to the first and second pins of the fuel level indicator to be tested, set the multimeter to the buzzer setting, and perform the following classification operations and judgments:

[0024] Scenario 1: If the full fuel indicator is being tested, and the simulated fuel tank is 2 / 3 full of aviation kerosene, which corresponds to the highest liquid level in a real fuel environment, then if the multimeter continuously beeps, the full fuel indicator is normal; otherwise, it is not normal.

[0025] Scenario 2: If the test is for a fuel level indicator, open the lower valve of the simulated fuel tank to allow aviation kerosene to flow out. When the multimeter beeps, close the lower valve of the lower valve and read the distance from the center point of the mounting surface to the aviation kerosene level from the scale on the outer side of the simulated fuel tank and record it. If the recorded distance is within the range of 255mm ± 8mm, the fuel level indicator is normal; otherwise, it is abnormal.

[0026] Scenario 3: If the fuel level sensor is being tested, open the lower valve of the simulated fuel tank to allow aviation kerosene to flow out. When the multimeter beeps, close the lower valve of the lower cover. Read and record the distance from the center point of the mounting surface to the aviation kerosene level from the scale on the outer side of the simulated fuel tank. If the recorded distance is within the range of 520mm ± 5mm, record it as n1. Continue to open the lower valve of the lower cover to allow aviation kerosene to flow out of the simulated fuel tank. When the multimeter beeps stop, close the lower valve of the lower cover. Read and record the distance from the center point of the mounting surface to the aviation kerosene level from the scale on the outer side of the simulated fuel tank as n2. Calculate the hysteresis zone by subtracting n1 from n2. If the hysteresis zone value is between 2.5mm and 10mm, the fuel level sensor is normal; otherwise, it is not normal.

[0027] Scenario 4: If the emergency fuel level indicator is being tested, open the lower valve of the simulated fuel tank to allow aviation kerosene to flow out of the simulated fuel tank. When the multimeter beeps, close the lower valve of the lower valve and read the distance from the center point of the mounting surface to the aviation kerosene level from the scale on the outer side of the simulated fuel tank and record it. If the recorded distance is within the range of 440mm ± 5mm, the emergency fuel level indicator is normal; otherwise, it is not normal.

[0028] Step 5: After the test is completed, drain all the aviation kerosene from the simulated fuel tank and clean the equipment with a silk cloth to ensure that the test apparatus is clean.

[0029] Beneficial effects

[0030] This utility model provides a fuel level signal tester. By setting up a simulated fuel tank and a replaceable top cover, the fuel level signal to be tested is fixed on the top cover. It can simulate the working environment of the fuel level signal on the aircraft on the ground for testing, thereby avoiding on-board testing and repeated disassembly and installation. The testing cost is low and the cycle is short, which is conducive to the rapid maintenance and release of aircraft. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0032] Figure 2 This is a schematic diagram of the structure of the oil quantity signal device to be tested according to an embodiment of this utility model;

[0033] Figure 3 This is a schematic diagram of the upper cover of an embodiment of the present utility model;

[0034] Figure 4 This is a schematic diagram of the lower cover of an embodiment of the present utility model;

[0035] In the diagram: 1-Bracket; 2-Simulated oil tank; 21-Scale; 3-Upper cap; 31-Inclined mounting surface; 32-Axial circular hole; 4-Lower cap; 41-Lower cap lower valve; 5-Nitrogen cylinder; 6-First pressure gauge; 7-Dual-way valve; 71-Inlet nozzle; 72-Inlet control switch; 73-Outlet nozzle; 74-Outlet control switch; 75-Vacuum release switch; 8-T-connector; 9-Second pressure gauge; 10-Multi-function gauge; 11-Fuel quantity signal device to be tested; 111-Mounting surface of fuel quantity signal device to be tested; 112-Pin interface of fuel quantity signal device to be tested; 113-Magnetic float. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0037] One embodiment of this utility model is, for example... Figure 1As shown, an oil quantity signal tester includes a bracket 1, a simulated oil tank 2, an upper cover 3, a lower cover 4, a nitrogen cylinder 5, a first pressure gauge 6, a dual-way valve 7, a three-way connector 8, a second pressure gauge 9, a high-pressure hose, and a multimeter 10.

[0038] The simulated fuel tank 2 is fixedly mounted on the bracket 1 using clamps; as shown Figure 2 and Figure 3 As shown, the upper end of the upper cover 3 is provided with an inclined mounting surface 31 for fixing and mounting the fuel quantity signal device 11 to be tested, simulating the installation of the fuel quantity signal device 11 to be tested on the machine; as Figure 4 As shown, the lower end of the lower cover 4 is provided with a valve 41 for simulating the intake and exhaust of fuel in the fuel tank 2; the upper cover 3 is detachably and sealingly installed on the top of the simulated fuel tank 2, and the lower cover 4 is fixedly and sealingly installed on the bottom of the simulated fuel tank 2; the upper cover 3, the lower cover 4 and the simulated fuel tank 2 form a sealed cavity for simulating the fuel tank of an aircraft fuel system; a scale 21 is provided on the outer side of the simulated fuel tank 2 to display the height of the center point of the mounting surface of the upper cover 3 from the level of aviation kerosene;

[0039] The nitrogen cylinder 5 is pre-filled with high-pressure nitrogen to simulate the high-pressure gas source on the machine and to test the airtightness of the oil quantity signal device 11 after it is installed in place; a first pressure gauge 6 is provided at the mouth of the nitrogen cylinder 5 to display the gas source pressure.

[0040] The dual-way valve 7 is equipped with an air inlet 71, an air inlet control switch 72, an air outlet 73, and an air outlet control switch 74. The dual-way valve 7 is also equipped with a venting switch 75. The air inlet control switch 72 is used to control the opening and closing of the air inlet 71, the air outlet control switch 74 is used to control the opening and closing of the air outlet 73, and the venting switch 75 is used for venting.

[0041] The outlet of the nitrogen cylinder 5 is connected to the inlet 71 of the dual-way valve 7 via a high-pressure hose; the outlet 73 of the dual-way valve 7 is connected to the second pressure gauge 9 and the lower valve 41 of the lower cap 4 via a high-pressure hose through a three-way connector 8.

[0042] The multimeter 10 is externally mounted. The positive and negative terminals of the multimeter 10 are used to connect to the first and second pins in the pin interface 112 of the fuel level signal device 11 to be measured. The first and second pins are connected to the signal sensor through the magnetic float 113 of the fuel level signal device 11 to be measured. When the multimeter 10 is rotated to the buzzer setting, the multimeter emits a buzzing sound, which indicates that the signal sensor is connected.

[0043] In this embodiment, the inclination angle of the inclined mounting surface 31 at the upper end of the upper cover 3 is selected according to the model of the oil level signal device 11 to be tested, and different upper covers 3 are made according to different specifications of the oil level signal device 11; the upper cover 3 is provided with an axially penetrating circular hole 32 in the middle, such as Figure 3 As shown, the diameter of the circular hole 32 matches the diameter of the lower section of the fuel level indicator 11 to be tested; the fuel level indicator 11 to be tested passes through the circular hole 32 from top to bottom and is inserted into the upper cover 3. The inclined mounting surface 31 at the upper end of the upper cover 3 is attached to the inclined surface 111 at the upper end of the fuel level indicator 11 to be tested and is fastened with screws. A rubber ring is provided between the upper cover 3 and the fuel level indicator 11 to be tested to ensure airtightness. After installation and fixing, the pin interface 112 of the fuel level indicator 11 to be tested is located outside the inclined mounting surface 31 at the upper end of the upper cover 3, which facilitates connection with the multimeter 10.

[0044] In this embodiment, the upper cover 3 is detachably installed on the top of the simulated oil tank 2 via threads.

[0045] In this embodiment, the simulated fuel tank 2 is made of transparent resin material.

[0046] In this embodiment, the method of using the above-mentioned fuel quantity signal tester to test the fuel quantity signal 11 is as follows:

[0047] Step 1: Select the matching upper cover 3 according to the model of the fuel quantity signal device 11 to be tested, fix the fuel quantity signal device 11 to be tested on the mounting surface 31 of the upper cover 3 with screws, and install the upper cover 3 onto the simulated fuel tank 2.

[0048] Step 2: Open the air intake control switch 72 and the air outlet control switch 74, close the venting switch 75, open the lower valve 41 of the lower cap, and control the gas in the nitrogen cylinder 5 to enter the simulated oil tank 2 through the dual valve 7 and the three-way connector 8. When the pressure of the second pressure gauge 9 reaches 0.3 MPa, close the air intake control switch 72. Apply soap solution to the joint between the upper cap 3 and the simulated oil tank 2, and between the upper cap 3 and the oil quantity signal device 11 to be tested. No bubbles should overflow from the joint. Visually observe the reading of the second pressure gauge 9 and keep it for two minutes. If the reading does not change, it proves that the airtightness meets the requirements.

[0049] Step 3: Open the vent switch 75 and vent until the pressure on the second pressure gauge 9 is 0MPa. Then disconnect the pipeline connection from the tee connector 8 to the lower valve 41 of the lower end of the cover and close the lower valve 41 of the lower end of the cover.

[0050] Step 4: Open the top cover 3 of the simulated fuel tank, fill it with 2 / 3 aviation kerosene, and then reinstall the top cover 3 on the simulated fuel tank 2; connect the positive and negative terminals of the multimeter 10 to the first and second pins of the fuel level signal device 11 to be tested, set the multimeter 10 to the buzzer setting, and perform the following classification operations and judgments:

[0051] Scenario 1: If the full fuel indicator is being tested, and the simulated fuel tank is 2 / 3 full of aviation kerosene, which corresponds to the highest liquid level in the real fuel environment, then if the multimeter 10 continuously beeps, the full fuel indicator is normal; otherwise, it is not normal.

[0052] Scenario 2: If the remaining fuel signal is being tested, open the lower cap valve 41 of the simulated fuel tank 2 to allow aviation kerosene to flow out of the simulated fuel tank 2. When the multimeter 10 beeps, close the lower cap valve 41. Read and record the distance from the center point of the mounting surface to the aviation kerosene level from the scale 21 on the outer side of the simulated fuel tank 2. If the recorded distance is within the range of 255mm ± 8mm, the remaining fuel signal is normal; otherwise, it is abnormal.

[0053] Scenario 3: If the fuel level sensor is being tested, open the lower valve 41 of the simulated fuel tank 2 to allow aviation kerosene to flow out of the simulated fuel tank 2. When the multimeter 10 beeps, close the lower valve 41 of the lower cover. Read and record the distance from the center point of the mounting surface to the aviation kerosene level from the scale 21 on the outer side of the simulated fuel tank 2. If the recorded distance is within the range of 520mm±5mm, record it as n1. Continue to open the lower valve 41 of the lower cover to allow aviation kerosene to flow out of the simulated fuel tank 2. When the multimeter 10 stops beeping, close the lower valve 41 of the lower cover. Read and record the distance from the center point of the mounting surface to the aviation kerosene level from the scale 21 on the outer side of the simulated fuel tank 2 as n2. Calculate the hysteresis zone by subtracting n1 from n2. If the value of the hysteresis zone is between 2.5mm and 10mm, the fuel level sensor is normal; otherwise, it is not normal.

[0054] Scenario 4: If the emergency fuel level indicator is being tested, open the lower cap valve 41 of the simulated fuel tank 2 to allow aviation kerosene to flow out of the simulated fuel tank 2. When the multimeter 10 beeps, close the lower cap valve 41. Read and record the distance from the center point of the mounting surface to the aviation kerosene level from the scale 21 on the outer side of the simulated fuel tank 2. If the recorded distance is within the range of 440mm ± 5mm, the emergency fuel level indicator is normal; otherwise, it is not normal.

[0055] Step 5: After the test is completed, drain all the aviation kerosene from the simulated fuel tank 2 and clean the equipment with a silk cloth.

[0056] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An oil level indicator tester characterized by: Includes a bracket, a simulated oil tank, an upper cap, a lower cap, a nitrogen cylinder, a first pressure gauge, a dual-way valve, a three-way connector, a second pressure gauge, a high-pressure hose, and a multimeter. The simulated fuel tank is fixedly mounted on the bracket by clamps; the upper end of the upper cover has an inclined mounting surface for fixing the fuel level signal to be tested, simulating the installation of the fuel level signal on the aircraft; the lower end of the lower cover has a valve for simulating the intake and exhaust of fuel in the fuel tank; the upper cover is detachably and sealingly mounted on the top of the simulated fuel tank, and the lower cover is fixedly and sealingly mounted on the bottom of the simulated fuel tank; the upper and lower covers and the simulated fuel tank form a sealed cavity for simulating the fuel tank of the aircraft fuel system; the outer side of the simulated fuel tank has a scale to display the height of the center point of the upper cover mounting surface from the aviation kerosene level; The nitrogen cylinder is pre-filled with high-pressure nitrogen to simulate the high-pressure gas source on the machine and to test the airtightness of the oil quantity signal device after it is installed in place; a first pressure gauge is provided at the mouth of the nitrogen cylinder to display the gas source pressure; The dual-way valve is equipped with an air inlet, an air inlet control switch, an air outlet, and an air outlet control switch. The dual-way valve is also equipped with a vent switch. The air inlet control switch is used to control the opening and closing of the air inlet, the air outlet control switch is used to control the opening and closing of the air outlet, and the vent switch is used to exhaust air. The nitrogen cylinder outlet is connected to the dual-way valve inlet via a high-pressure hose; the dual-way valve outlet is connected to the second pressure gauge and the lower valve of the lower cap via a high-pressure hose through a three-way connector. The multimeter is externally mounted. Its positive and negative terminals are connected to pins one and two in the pin interface of the fuel level signal sensor to be measured. Pins one and two are connected to the signal sensor through the magnetic float of the fuel level signal sensor to be measured. When the multimeter is rotated to the buzzer setting, the beeping sound indicates that the signal sensor is activated.

2. The oil level indicator tester of claim 1, wherein: The inclination angle of the upper inclined mounting surface of the upper cover is selected according to the model of the fuel level indicator to be tested. Different upper covers are made according to different fuel level indicator specifications. The upper cover has an axial through hole in the middle, and the diameter of the hole matches the diameter of the lower section of the fuel level indicator to be tested. The fuel level indicator to be tested is inserted into the upper cover through the hole from top to bottom. The upper inclined mounting surface of the upper cover is in contact with the upper inclined surface of the fuel level indicator to be tested and is fastened with screws. A rubber ring is provided between the upper cover and the fuel level indicator to be tested to ensure airtightness. After installation and fixing, the pin interface of the fuel level indicator to be tested is located on the outside of the upper inclined mounting surface of the upper cover, which is convenient for connection with the multimeter.

3. The oil level indicator tester of claim 1, wherein: The top cover is detachably mounted on the top of the simulated oil tank via threads.

4. The oil quantity signal tester according to claim 1, characterized in that: The simulated fuel tank is made of transparent resin material.

Images