CN107380482B - Universal test bench for pneumatic accessories of airplane - Google Patents

Abstract

The invention relates to a universal test bench for aircraft pneumatic accessories, which includes a test bench body. The outside of the test bench body is provided with a console and a control panel. The test bench body is provided with an air-conditioning system and an electrical system. The electrical system and The air-conditioning system is connected to provide power to the air-conditioning system; the air-conditioning system includes a first test unit for testing ordinary pneumatic accessories, a second test unit for testing special pneumatic accessories, and a second test unit for testing aircraft fuel ventilation. Flow test unit for pneumatic accessories of booster systems. The invention can perform pressure and flow performance testing on the pneumatic accessories of the aircraft air-conditioning system, environmental control system and fuel ventilation and pressurizing system, and meets the requirements of the pneumatic accessories of the aircraft air-conditioning system, environmental control system and fuel ventilation and pressurizing system before installation and on a regular basis. Basic requirements for performance testing during work.

Description

Universal test bench for aircraft pneumatic accessories

Technical field

The invention belongs to the technical field of aircraft accessory testing, and relates to aircraft pneumatic accessory testing technology. Specifically, it relates to a universal test bench for aircraft pneumatic accessories, which is used for the installation of pneumatic accessories of air-conditioning systems, environmental control systems and fuel ventilation and boosting systems on aircraft. Performance testing of pneumatic accessories before and during regular work.

Background technique

Because pneumatic systems are safe, reliable, and have long service life, pneumatic technology is used on aircraft. Pneumatic technology is mainly used in aircraft air-conditioning systems, environmental control systems, and fuel ventilation and pressurization systems. Before the pneumatic accessories involved in the above system are installed or after the pneumatic accessories have been working regularly for a period of time, the performance of the pneumatic accessories needs to be tested to avoid aircraft flight safety problems caused by damage or failure of the pneumatic accessories to work properly, thereby ensuring the aircraft's good performance.

At present, most pneumatic accessories performance test benches have relatively single functions, and aircraft users are restricted by objective conditions. Many users are not equipped with test equipment matching pneumatic accessories. Therefore, developing a universal test bench for pneumatic accessories can meet the performance testing of pneumatic accessories of aircraft air-conditioning system, environmental control system and fuel ventilation and boosting system before installation and after regular operation. It is of great significance to ensure the aircraft good rate and improve aircraft safety. Significance.

Contents of the invention

In view of the above-mentioned problems existing in the prior art, the present invention provides a universal test bench for aircraft pneumatic accessories, which can perform pressure and flow performance testing on the pneumatic accessories of the aircraft air-conditioning system, environmental control system and fuel ventilation and boosting system.

In order to achieve the above object, the present invention provides a universal test bench for aircraft pneumatic accessories, which includes a test bench body. The outside of the test bench body is provided with a console and a control panel. The inside of the test bench is provided with an air-conditioning system and an electrical system. , the electrical system is connected to the air-conditioning system and supplies power to the air-conditioning system;

The air-conditioning system includes a first test unit for testing common pneumatic accessories, a second test unit for testing special pneumatic accessories, and a flow test unit for testing pneumatic accessories of the aircraft fuel ventilation and boosting system;

The first test unit includes a first pipeline with an air inlet nozzle at one end and an air outlet nozzle at the other end. The first pipeline is provided with a pressure gauge with a range of 0-25MPa and a 5MPa pressure gauge along the air outlet direction. pressure regulator, brake regulator, air-conditioning switch and a pressure gauge with a range of 0-1.6MPa; three branch pipelines are connected to the first pipeline, and the first branch pipeline is connected to the air inlet nozzle and the 5MPa pressure reducer On the first pipeline between them, the second branch pipeline and the third branch pipeline are both connected to the first pipeline between the 5MPa pressure reducer and the brake regulator; the air outlet end of each branch pipeline Both are equipped with air outlet nozzles. The first branch pipe and the second branch pipe are equipped with air-conditioning switches and pressure gauges with a range of 0-16MPa in sequence along the air outlet direction. The second branch pipe is sequentially equipped in the air outlet direction. There is a cold air switch and a pressure gauge with a range of 0-10MPa. The third branch pipeline is provided with a 0.3MPa pressure reducer, a cold air switch and a pressure gauge with a range of 0-0.4MPa along the air outlet direction;

The second test unit includes a first test circuit for testing the electromagnetic air-conditioning valve, a second test circuit for testing the brake pressure reducing valve, a third test circuit for testing the air release solenoid valve, and a first test circuit for testing the brake pressure reducing valve. A fourth test circuit for the brake pressure regulator and brake differential, a fifth test circuit for testing the second brake pressure regulator and brake distributor, a sixth test circuit for testing the brake amplifier, a test circuit for testing the cylinder and The seventh test circuit of the pneumatic switch and the booster circuit used to increase the air source pressure of the pneumatic accessories under test;

The flow test unit includes a small flow test circuit for testing gas flow in the range of 16ml/min- ^10m3 /h and a large flow test circuit for testing gas flow in the range of ^10-100m3 /h.

Preferably, the first pipeline and the outlet nozzle end of each branch pipeline are provided with pressure relief valves.

Preferably, the first pipeline between the air inlet nozzle and the pressure gauge with a range of 0-25MPa is provided with a cold air filter and a one-way valve in sequence.

Preferably, the first test circuit includes a second pipeline connected to the first pipeline, a third pipeline connected to the third branch pipeline, and an electromagnetic cold air switch air inlet nozzle connected to the electromagnetic cold air valve. The second pipeline and the third pipeline are both connected to the air inlet nozzle of the electromagnetic cold air switch; the second pipeline is connected to the high-pressure gas bottle, and the second pipeline is successively provided with an air inlet switch and a pressure range of 0-16MPa Table; the third pipeline is connected to the low-pressure gas cylinder, and the third pipeline is successively provided with an air inlet switch and a pressure gauge with a range of 0-10MPa.

Preferably, the second test circuit includes a fourth pipeline connected to the first pipeline and a 1.5L high-pressure cold air bottle connected to the fourth pipeline, and air intake switches are sequentially provided on the fourth pipeline , brake pressure reducing valve and pressure gauge with a range of 0-16MPa.

Further, the third test circuit includes a fifth pipeline connected to the first pipeline, a fourth branch pipeline connected to the fifth pipeline, and a 0.5L pipe connected to the fifth pipeline. A low-pressure gas cylinder and a 1L low-pressure gas cylinder connected to the fourth branch pipeline; the fifth pipeline is provided with a 5MPa pressure reducer, a pressure gauge with a range of 0-10MPa for measuring the intake pressure, and an intake switch. , a bleed solenoid valve and a pressure gauge with a range of 0-10MPa for measuring the outlet pressure; the fourth branch pipeline is connected to the fifth pipeline between the air intake switch and the bleed solenoid valve.

Further, the fourth test circuit includes a sixth pipeline connected to the third branch pipeline, a fifth branch pipeline connected to the sixth pipeline, and a 1.5L pipeline connected to the sixth pipeline. A high-pressure cold air bottle and a 0.75L low-pressure cold air bottle connected to the fifth branch pipeline. The sixth pipeline is provided with an air inlet switch, a first brake regulator and a range for measuring the outlet pressure of 0- 10MPa pressure gauge; the fifth branch pipeline is connected to the sixth pipeline of the air outlet of the first brake pressure regulator, and the fifth branch pipeline is sequentially provided with an air intake switch, a brake differential and a measuring range It is a pressure gauge of 0-10MPa.

The fifth test circuit includes a seventh pipeline connected to the third branch pipeline, a sixth branch pipeline connected to the seventh pipeline, a 2L high-pressure gas bottle connected to the seventh pipeline, and A 1L low-pressure cold air bottle connected to the sixth branch pipeline, and the seventh pipeline is provided with an air inlet switch, a second brake pressure regulator and a pressure gauge with a range of 0-10MPa for measuring the outlet pressure; The sixth branch pipeline is connected to the seventh pipeline of the air outlet of the second brake pressure regulator. The sixth branch pipeline is sequentially provided with an air intake switch, a brake distributor and a pressure range of 0-10MPa. surface.

Preferably, the sixth test circuit includes an eighth pipeline connected to the third branch and a 0.5L low-pressure gas bottle connected to the eighth pipeline, and air intake switches are sequentially provided on the eighth pipeline. , a brake amplifier and a pressure gauge with a range of 0-10MPa for measuring the outlet pressure; the brake amplifier is connected to the air outlet of the second brake pressure regulator through a seventh branch pipeline, and the seventh branch pipeline Equipped with air intake switch.

The seventh test circuit includes a ninth pipeline connected to the third branch pipeline, a pneumatic switch connected to the ninth pipeline, and a cylinder connected to the pneumatic switch. The ninth pipeline is provided with There is an air intake switch, the pneumatic switch closing nozzle of the pneumatic switch is connected to the cylinder closing nozzle of the cylinder, and the pneumatic switch lowering nozzle of the pneumatic switch is connected to the cylinder lowering nozzle of the cylinder.

Preferably, the pressurization circuit includes a tenth pipeline connected to the first pipeline, the air outlet end of the tenth pipeline is provided with an air outlet nozzle, and the tenth pipeline is provided with a 5MPa reducer. Pressure regulator, air inlet switch, pressure gauge with a range of 0-10MPa, pneumatic switch, supercharger, pressure gauge with a range of 0-25MPa for measuring the outlet pressure of the supercharger, outlet switch, and a pressure gauge for measuring the output pressure A pressure gauge with a measuring range of 0-25MPa; the pneumatic switch lowers the nozzle and is connected to the low-pressure chamber of the supercharger through a pipeline, and the pneumatic switch puts the nozzle up and passes through a one-way valve. The pipeline is connected to the high pressure chamber of the supercharger.

Preferably, the small flow test circuit includes an air inlet pipe with an air inlet nozzle and a pressure gauge with a range of 0-1.6MPa at the air inlet end. The air inlet pipe is connected with multiple flow meters for testing different flows. The measuring range of each flow meter is different, and a test switch is provided on the air inlet pipeline between the pressure gauge with a measuring range of 0-1.6MPa and each flow meter; the large flow test circuit includes a test switch at the air inlet end. The air inlet nozzle and the air inlet pipeline of a pressure gauge with a measuring range of 0-1.6MPa. The air inlet pipeline is connected to a flow meter with a measuring range of ^10-100m3 /h. The flow meter and the measuring range are 0-1.6MPa. There is a test switch between the pressure gauges.

Compared with the existing technology, the advantages and positive effects of the present invention are:

The invention can perform pressure and flow performance testing on pneumatic accessories of aircraft air-conditioning systems, environmental control systems and fuel ventilation and boosting systems. It can also test the sealing, sensitivity, accuracy and intake and exhaust speeds of special pneumatic accessories. Performance parameter testing meets the basic requirements for performance testing of pneumatic accessories of the aircraft's air-conditioning system, environmental control system and fuel ventilation and boosting system before installation and during regular operation.

Description of the drawings

Figure 1 is a test principle diagram of the air-conditioning system in the test bench according to the embodiment of the present invention.

Figure 2 is a test principle diagram of the first test unit according to the embodiment of the present invention.

Figure 3 is a test principle diagram of the first test circuit according to the embodiment of the present invention.

Figure 4 is a test principle diagram of the second test loop according to the embodiment of the present invention.

Figure 5 is a test principle diagram of the third test circuit according to the embodiment of the present invention.

Figure 6 is a test principle diagram of the fourth test loop according to the embodiment of the present invention.

Figure 7 is a test principle diagram of the fifth test circuit according to the embodiment of the present invention.

Figure 8 is a test principle diagram of the sixth test circuit according to the embodiment of the present invention.

Figure 9 is a test principle diagram of the seventh test circuit according to the embodiment of the present invention.

Figure 10 is a schematic diagram of the test of the booster circuit according to the embodiment of the present invention.

Figure 11 is a test principle diagram of the flow test unit according to the embodiment of the present invention.

1. Air intake nozzle, 2. Cold air filter, 3. One-way valve, 4. 5MPa pressure reducer, 5. Second brake regulator, 6. 0.3MPa pressure reducer, 7. First brake pressure regulator, 8 : Brake differential, 9. 1.5L high-pressure cold air bottle, 10. 0.75L low-pressure cold air bottle, 11. Brake distributor, 12. 2L high-pressure gas bottle, 13. 1L low-pressure gas bottle, 14. Brake amplifier, 15. 0.5 L low-pressure gas cylinder, 16. 16-160mL/min flow meter, 17. 0.16-1.60L/min flow meter, 18. 0.1-1m ³ /h flow meter, 19. 1-10m ³ /h flow meter meter, 20. 10-100m ³ /h flow meter, 21. 0-25MPa pressure gauge, 22. 0-16MPa pressure gauge, 23. 0-10MPa pressure gauge, 24. 0-1.6MPa pressure gauge , 25. 0-0.16MPa pressure gauge, 26. Brake pressure reducing valve, 27. Pneumatic switch, 28. One-way valve, 29. Supercharger, 30. Electromagnetic air-conditioning valve, 31. High-pressure gas cylinder, 32. Low-pressure Gas bottle, 33. Air outlet nozzle, 34. Air outlet nozzle, 35. Air outlet nozzle, 36. Air outlet nozzle, 37. Air outlet nozzle, 38. Pneumatic switch closes the nozzle, 39. Pneumatic switch puts the nozzle down, 40. Cylinder retracts the nozzle, 41. Cylinder puts the nozzle down, 42. Air inlet nozzle, 43. Air inlet nozzle, 44. Cylinder, 45. Electromagnetic air conditioner switch air inlet nozzle, 46. Air conditioner switch, 47. Bleed electromagnetic Valve, 48. First pipeline, 49. Second pipeline, 50. Third pipeline, 51. Fourth pipeline, 52. Fifth pipeline, 53. Sixth pipeline, 54. Seventh pipeline , 55, the eighth pipeline, 56, the ninth pipeline, 57, the tenth pipeline.

Detailed ways

Below, the present invention is described in detail through exemplary embodiments. It is to be understood, however, that elements, structures, and features of one embodiment may be beneficially combined in other embodiments without further recitation.

The invention discloses a universal test bench for aircraft pneumatic accessories, which includes a test bench body. The outside of the test bench body is provided with a console and a control panel. The test bench body is provided with an air-conditioning system and an electrical system. The electrical system Connected to the air-conditioning system to provide power to the air-conditioning system; the air-conditioning system includes a first test unit for testing ordinary pneumatic accessories, a second test unit for testing special pneumatic accessories, and a second test unit for testing aircraft fuel Flow test unit for pneumatic accessories of ventilation and boosting systems. Detailed description will be given below with reference to the accompanying drawings and specific embodiments.

In order to complete the test of ordinary pneumatic accessories, referring to Figures 1 and 2, the first test unit includes a first pipeline 48 with an air inlet nozzle 1 at one end and an air outlet nozzle 35 at the other end. The pipeline 48 is provided with a pressure gauge 21 with a range of 0-25MPa, a 5MPa pressure reducer 4, a brake regulator 5, an air conditioner switch 46 and a pressure gauge 22 with a range of 0-1.6MPa along the air outlet direction; the first pipeline There are three branch pipes connected to 48. The first branch pipe is connected to the first pipe 48 between the intake nozzle 1 and the 5MPa pressure reducer 4, the second branch pipe and the third branch pipe The pipelines are all connected to the first pipeline 48 between the 5MPa pressure reducer 4 and the brake regulator 5; the air outlet end of each branch pipeline is equipped with an air outlet nozzle, and the first branch pipeline The air-conditioning switch 46 and the pressure gauge 22 with a measuring range of 0-16MPa are sequentially provided on the second branch pipeline and the air-outlet direction of the second branch pipeline. Pressure gauge 23, the third branch pipeline is provided with a 0.3MPa pressure reducer 6, a cold air switch 46 and a pressure gauge 25 with a range of 0-0.4MPa in sequence along the air outlet direction.

Continuing to refer to Figures 1 and 2, the first pipeline 48 and the nozzle end of the air outlet on each branch pipeline are provided with pressure relief valves. After the test is completed, turn off each air-conditioning switch and open the pressure relief valve to release the air-conditioning in the test circuit to ensure the safety of accessories and personnel.

Continuing to refer to Figures 1 and 2, preferably, the first pipeline 48 between the air inlet nozzle and the pressure gauge with a range of 0-25MPa is equipped with a cold air filter 2 and a one-way valve 3. Use the cold air filter 2 to filter impurities in the cold air to prevent clogging of the test pipeline and the pneumatic accessories being tested. The one-way valve 3 prevents the cold air entering the pipeline from flowing back.

In addition to ordinary pneumatic accessories, the aircraft air-conditioning system also includes special pneumatic accessories, such as: electromagnetic air-conditioning valve, brake pressure reducing valve, bleed solenoid valve, brake pressure regulator, brake differential, brake distributor, Brake amplifiers, cylinders and pneumatic switches, etc. In order to complete the test of the special pneumatic accessories, continue to refer to Figure 1. The second test unit includes a first test circuit for testing the electromagnetic cold air valve 30, a second test circuit for testing the brake pressure reducing valve 26, The third test circuit for testing the bleed solenoid valve 47, the fourth test circuit for testing the first brake pressure regulator 7 and the brake differential 8, and the second test circuit for testing the second brake pressure regulator 5 and the brake distributor 11 The fifth test circuit, the sixth test circuit for testing the brake amplifier 14, the seventh test circuit for testing the cylinder 44 and the pneumatic switch 27, and the booster circuit for increasing the air source pressure of the pneumatic accessories under test.

In order to complete the flow test of the pneumatic accessories of the aircraft fuel ventilation and boosting system, the flow test unit includes a small flow test circuit for testing gas flow in the range of 16ml/min- ^10m3 /h and a small flow test circuit for testing the gas flow in the range of 10-100m Large flow test circuit with gas flow rate within ³ /h.

The electromagnetic air-conditioning valve is used to control the working air path of aircraft parachute release and parachute throwing. That is, when the circuit is connected, cold air is input into the cylinder; when the circuit is powered off, the air circuit is closed and the cold air in the cylinder is eliminated. In order to complete the test of the electromagnetic air-conditioning valve, as a preferred design of the above-mentioned test bench, see Figures 1 and 3. The first test circuit includes a second pipeline 49 connected to the first pipeline 48 and a third branch pipeline. The third pipeline 50 and the electromagnetic cold air switch air inlet nozzle 45 are connected to the electromagnetic cold air valve 30. The second pipeline 49 and the third pipeline 50 are both connected to the electromagnetic cold air switch air inlet nozzle 45; The second pipeline 49 is connected to the high-pressure gas cylinder 31. The second pipeline 49 is successively provided with an air inlet switch and a pressure gauge 22 with a range of 0-16MPa; the third pipeline 50 is connected to the low-pressure gas cylinder 32. The third pipeline 50 is sequentially provided with an air inlet switch and a pressure gauge 23 with a range of 0-10MPa.

The brake pressure reducing valve is used to control the intake and release of aircraft emergency brakes and adjust the brake pressure. In order to complete the test of the brake pressure reducing valve, as a preferred design of the above-mentioned test bench, see Figures 1 and 4, the second test circuit includes a fourth pipeline 51 connected to the first pipeline 48 and a fourth pipeline 51 connected to the first pipeline 48. The fourth pipeline 51 is connected to the 1.5L high-pressure cold air bottle 9. The fourth pipeline 51 is provided with an air intake switch, a brake pressure reducing valve 26 and a pressure gauge 22 with a range of 0-16MPa.

The bleed solenoid valve is used to receive the electrical signal from the inertial sensor when the aircraft wheel comes off, cuts off the brake air path and discharges the cold air in the brake chamber, thereby solving the problem of the wheel coming off and preventing the tire from bursting. In order to complete the test of the deflation solenoid valve, as a preferred design of the above-mentioned test bench, see Figures 1 and 5, the third test circuit includes a fifth pipeline 52 connected to the first pipeline 48, and a fifth pipeline 52 connected to the first pipeline 48. The fourth branch pipeline connected to the fifth pipeline 52, the 0.5L low-pressure gas bottle 15 connected to the fifth pipeline 52, and the 1L low-pressure gas bottle 13 connected to the fourth branch pipeline; the fifth pipeline 52 is provided with a 5MPa pressure reducer 4, a pressure gauge 23 for measuring the inlet pressure with a range of 0-10MPa, an air inlet switch, a bleed solenoid valve 47 and a pressure gauge for measuring the outlet pressure with a range of 0-10MPa. Pressure gauge 23; the fourth branch pipeline is connected to the fifth pipeline 52 between the air intake switch and the exhaust solenoid valve 47.

The first brake regulator is used to control the air intake and exhaust of the aircraft and adjust the brake pressure. The brake differential is used to ensure that the left and right wheels are braked independently when the aircraft is taxiing to control the direction and operation of the aircraft during takeoff or landing and to enable the aircraft to turn on the ground. In order to complete the test of the first brake regulator and the brake differential, as a preferred design of the above-mentioned test bench, continue to refer to Figures 1 and 6. The fourth test circuit includes a sixth test circuit connected to the third branch pipeline. Pipeline 53, a fifth branch pipe connected to the sixth pipeline 53, a 1.5L high-pressure cold air bottle 9 connected to the sixth pipeline 53, and a 0.75L low-pressure cold air bottle connected to the fifth branch pipe. Bottle 10, the sixth pipeline 53 is provided with an air inlet switch, a first brake pressure regulator 7 and a pressure gauge 23 with a range of 0-10MPa for measuring the outlet pressure; the fifth branch pipeline is connected On the sixth pipeline 53 of the air outlet of the first brake pressure regulator 7, the fifth branch pipeline is provided with an air intake switch, a brake differential 8 and a pressure gauge 23 with a range of 0-10MPa.

The second brake regulator is also used to control the air intake and exhaust of the aircraft and adjust the brake pressure. The brake distributor also ensures that the left and right wheels are braked independently when the aircraft is taxiing to control the direction and operation of the aircraft during takeoff or landing and enable the aircraft to turn on the ground. In order to complete the test of the second brake regulator and the brake distributor, as a preferred design of the above-mentioned test bench, continue to refer to Figures 1 and 7. The fifth test circuit includes a seventh pipe connected to the third branch pipe. Road 54, a sixth branch pipeline connected to the seventh pipeline 54, a 2L high-pressure gas bottle 12 connected to the seventh pipeline 54, and a 1L low-pressure cold gas bottle 13 connected to the sixth branch pipeline, The seventh pipeline 54 is provided with an air intake switch, a second brake pressure regulator 5 and a pressure gauge 23 with a range of 0-10MPa for measuring the outlet pressure; the sixth branch pipeline is connected to the On the seventh pipeline 54 of the air outlet of the second brake pressure regulator 5, the sixth branch pipeline is provided with an air intake switch, a brake distributor 11 and a pressure gauge 23 with a range of 0-10MPa.

The brake amplifier is used to accelerate the braking and releasing actions and proportionally amplify the outlet pressure adjusted by the brake regulator. In order to complete the test of the brake amplifier, as a preferred design of the above-mentioned test bench, continue to refer to Figures 1 and 8. The sixth test circuit includes an eighth pipe 55 connected to the third branch circuit and an eighth pipe 55 connected to the third branch circuit. The 0.5L low-pressure gas cylinder 15 is connected to the pipeline 55. The eighth pipeline 55 is provided with an air intake switch, a brake amplifier 14 and a pressure gauge 23 with a range of 0-10MPa for measuring the outlet pressure; the brake amplifier 14 is connected to the air outlet of the second brake pressure regulator 5 through a seventh branch pipeline, and an air intake switch is provided on the seventh branch pipeline.

The cylinder uses cold air expansion to push the piston connecting rod to move to control the movement of the components. The pneumatic switch controls the retraction and release of the cylinder. In order to complete the test of the cylinder and the pneumatic switch, as the preferred design of the above-mentioned test bench, continue to refer to Figures 1 and 9. The seventh test circuit includes a ninth pipeline 56 connected to the third branch pipeline and The pneumatic switch 27 connected to the ninth pipeline 56 and the cylinder 44 connected to the pneumatic switch 27 are provided with an air inlet switch. The pneumatic switch of the pneumatic switch 27 retracts the nozzle 38 The pneumatic switch lowering nozzle 39 of the pneumatic switch 27 is connected to the cylinder lowering nozzle 41 of the air cylinder 44 .

In order to increase the air source pressure of the pneumatic accessories under test, as a preferred design of the above-mentioned test bench, see Figures 1 and 10, the pressurization circuit includes a tenth pipeline 57 connected to the first pipeline 48. The air outlet end of the tenth pipeline 57 is provided with an air outlet nozzle 37. The tenth pipeline 57 is provided with a 5MPa pressure reducer 4, an air inlet switch, a pressure gauge 23 with a range of 0-10MPa, and a pneumatic switch 27. , supercharger 29, a pressure gauge 21 with a range of 0-25MPa for measuring the outlet pressure of the supercharger, an outlet switch, a pressure gauge 21 with a range of 0-25MPa for measuring the output pressure; the pneumatic switch 27 The lowering nozzle of the pneumatic switch is connected to the low-pressure chamber of the supercharger 29 through a pipeline, and the pneumatic switch retracting nozzle of the pneumatic switch 27 is connected to the supercharger 29 through a pipeline provided with a one-way valve 28 High pressure chamber connection.

In order to complete the small flow and large flow test of the pneumatic accessories of the aircraft fuel ventilation and boosting system, as the preferred design of the above test bench, see Figure 1 and Figure 11, the small flow test circuit includes an air inlet nozzle 42 and The air inlet pipeline of the pressure gauge 24 with a measuring range of 0-1.6MPa. The air inlet pipeline is connected with multiple flow meters for testing different flows. Each flow meter has a different measuring range. The measuring range is 0-1.6MPa. A test switch is provided on the air inlet pipeline between the pressure gauge 24 and each flow meter; the large flow test circuit includes an inlet nozzle 43 at the air inlet end and a pressure gauge 24 with a range of 0-1.6MPa. Air pipeline, the air inlet pipeline is connected to a flow meter 20 with a range of 10-100m ³ /h, and a test switch is provided between the flow meter 20 and the pressure gauge 24 with a range of 0-1.6MPa. As a preferred design, continue to refer to Figures 1 and 11. In the small flow test circuit, the air inlet pipeline is connected to four flow meters for testing different flows, which are: flow meter 16 with a measuring range of 16-160mL/min. Flowmeter 17 with a range of 0.16-1.60L/min, flowmeter 18 with a range of 0.1-1m ³ /h, flowmeter 19 with a range of 1-10m ³ /h.

After the above-mentioned test bench is connected to the gas cylinder, 10.8-12.7MPa air pressure can be input, and then transmitted to the first test unit, the second test unit and the flow test unit respectively.

1. Test of ordinary pneumatic accessories:

After the cold air passes through the air inlet nozzle 1, the cold air filter 2 and the one-way valve 3, it can obtain an air source of 10.8-12.7MPa. The air source pressure can be measured by a pressure gauge 21 with a range of 0-25MPa and adjusted by a 5MPa pressure reducer 4 and a brake. After the regulator 5 and the 0.3MPa pressure reducer 6 are installed, air sources of 5MPa, 1MPa, and 0.3MPa are formed respectively, and the cold air switches of the first branch pipeline, the second branch pipeline, the first pipeline 48, and the third branch pipeline are opened. , the air-conditioning at the required pressure can be obtained, and the air-conditioning pressure is indicated by the pressure gauges 22, 23, 24, and 25 respectively. For convenience of use, the outlet pressures of the 5MPa pressure reducer 4, the brake regulator 5, and the 0.3MPa pressure reducer 6 should usually be 5MPa, 1MPa, and 0.3MPa respectively.

2. Testing of special pneumatic accessories:

(1)Electromagnetic air conditioner valve test

Working reliability test:

When the air intake nozzle is not inflated, turn on the power, adjust the variable resistor, and slowly adjust it from 0 until the electromagnet makes a "ticking" sound. The voltage should not be greater than 22V, and the current consumption should not be greater than 3.5A. Turn on the voltage for the fifth time. It should be stable with no more than 2V error each time.

When the air intake nozzle is inflated, inflate the air to a pressure of 0.98MPa, turn on the power, and when the voltage ≯ 22V, test 5 times. The electromagnetic air-conditioning valve should work normally; inflate the air to a pressure of 6.86MPa, turn on the power, and when the voltage ≯ 20V, test 5 times, the solenoid air conditioner valve should work normally.

Rapidity and continuity testing:

The air pressure is 1.96-2.94MPa, the voltage is 24V, and the rocker must make 12 sounds when rotating at a speed of no more than 2 seconds per revolution, that is, it cannot not work once.

Sealing test:

When no power is supplied, add 0.98MPa, 2.94MPa, 4.9MPa and 6.86MPa air pressure respectively, and maintain them for 1 minute each. No air leakage is allowed anywhere.

Turn on the power supply voltage 24V, add 0.98MPa, 2.94MPa, 4.9MPa and 6.86MPa air pressure respectively. The air leakage volume under each pressure is ≯ 200 ml/second.

Comprehensive testing:

The air outlet nozzle is connected to the spring compression cylinder. When the voltage is 24V, the air inlet pressure is 0.98MPa, 2.94MPa, 4.9MPa. At this time, the power is energized. Regardless of its continuous working speed, there should be no sluggishness or air leakage. and other malfunctions.

(2) Brake pressure reducing valve test

Performance test: Turn on the air inlet switch, input 10.8-12.7MPa air pressure into the air inlet of the brake pressure reducing valve, move the control handle, and the outlet pressure reduction range is 0.3-6.9MPa.

Check the valve inlet and exhaust speed:

According to the air intake speed, adjust the decompression pressure to 6.9MPa, quickly press the control handle, and the time required for the pressure of the 1.5-liter gas cylinder to rise from 0 to 6.2MPa should be no more than 2 seconds.

Exhaust speed: when the control handle is quickly raised, the time required for the pressure of a 1.5-liter gas cylinder to drop from 6.2MPa to 0 liters should not be greater than 2.5 seconds.

Maximum control force: no more than 55 kg.

Total stroke: no more than 7 mm, of which the empty stroke is no more than 2.5 mm.

(3) Vent solenoid valve test

Valve running-in experiment:

Block the air outlet nozzle, add 1.176MPa air pressure to the air inlet nozzle, and turn on the electromagnet 200 times, no more than 80-100 times per minute, to allow the valve to run in.

Sealing test:

Open the 1L gas cylinder, add 1.764MPa air pressure to the exhaust solenoid valve, then close the air inlet switch and keep it for 1 minute. The pressure drop value of the air inlet pressure gauge should not exceed 0.49MPa.

Close the 0.5L gas bottle and the 1L gas bottle, disconnect the electromagnet, add 0.196MPa and 1.764MPa air pressure to the deflation solenoid valve respectively, then close the air inlet switch, hold each for 1 minute, the pressure drop value of the air inlet pressure gauge should not be decline.

Check the charging and deflating time:

When the electromagnet is turned on, the time required for the pressure of the outlet pressure gauge to drop from 1.764MPa to 0.049MPa does not exceed 1.2 seconds.

When the electromagnet is disconnected, the time required for the pressure of the outlet pressure gauge to rise from 0 to 1.127MPa does not exceed 1.2 seconds.

Check the accuracy of your work:

Disconnect the 0.5L gas bottle and the 1L gas bottle, add air pressure of 1.176MPa and 1.764MPa respectively, and turn on the electromagnet 20 times. At the moment when the electromagnet is turned on each time, the vent hole should start to deflate.

Check the minimum operating voltage of the electromagnetic valve:

Disconnect the 0.5L gas bottle and the 1L gas bottle, set the voltage to 18V, add 1.176MPa air pressure, and turn on the electromagnet 5 times. The vent hole should start deflating immediately after each turn on.

(4) First brake regulator test

Experimental conditions: Experiment at a temperature of 15-30°C. The input pressure is 4.9MPa.

Sealing test:

In the air intake chamber, adjust the pressure of the air intake pressure gauge to 4.9MPa, then turn off the air intake switch and hold it for 1 minute. The pressure drop indicated on the air intake pressure gauge is allowed to be no more than 0.049MPa.

In the decompression chamber, close the 1.5L gas cylinder, use the control handle to adjust the pressure decibels of the outlet pressure gauge to 2.45MPa and 0.49MPa, hold each for 1 minute, and the pressure drop indicated on the outlet pressure gauge is allowed to be no greater than 0.049MPa.

Check valve operation constancy:

Adjust the decompression pressure to a certain value, namely 0.98MPa, 1.47MPa, 2.45MPa, fix the position of the limit screw, press the control handle onto the limit screw, do this three times each, and record the pressure value not greater than 0.098MPa.

Check the valve working accuracy:

Adjust the decompression pressure to 1.764, fix the position of the limiting screw, then relax the control handle, and reduce the decompression pressure to 1.47MPa, 0.98MPa, 0.49MPa, 0.196MPa in sequence. After each decrease, push the control handle back to the original adjustment position, the difference between the decompression pressure recovery value and the original adjusted pressure should not be greater than 0.098MPa.

Check the valve inlet and exhaust speed:

For the air intake speed, when the cylinder pressure is not less than 9.8MPa and the first brake regulator inlet pressure is 4.9MPa, adjust the decompression pressure to 2.45MPa, quickly press the control handle, and the decompression pressure rises from 0 When reaching 2.352MPa, the time required should be no more than 2 seconds.

For the exhaust speed, adjust the decompression pressure to 2.45MPa. When the control handle is quickly raised and the decompression pressure drops from 2.45MPa to 0.196MPa, the time required should not be more than 2.5 seconds.

(5)Brake differential test

Maximum tilt angle check:

The maximum angle at which the rocker arm tilts from the neutral position to either side shall not be less than 27 degrees.

Sealing test:

Place the rocker arm in the neutral position, turn on the air inlet switch, and input a pressure of 2.45MPa. When the pressure on the outlet pressure gauge reaches 2.45MPa, close the air inlet switch and keep it for 1 minute. The pressure drop on the outlet pressure gauge should not decrease. More than 0.049MPa.

Gradually tilt the rocker arm of the brake differential to one side from the middle position until the pressure on the left or right outlet pressure gauge drops to zero. At this moment, the pressure drop on the pressure gauge on the other side should not be greater than 0.049MPa; when the rocker arm tilts to the opposite side, check the other chamber of the brake differential according to the above requirements.

Work Accuracy Experiment:

Place the brake differential rocker arm in the middle position, turn on the air intake switch, and then operate the decompression valve to input 2.45MPa cold air to the brake differential and must evenly enter the two cylinders after passing through the brake differential.

Inlet and exhaust speed check:

Adjust the limit bolt so that the maximum output pressure of the pressure reducing valve is 2.45MPa, and the cylinder pressure must not be lower than 9.8MPa.

Check the double-chamber intake and exhaust speed, place the rocker arm in the middle position, quickly press the control handle to the limit bolt, when the pressure on the outlet pressure gauge reaches 2.352MPa, the time required shall not exceed 2.5 seconds; quickly press the control handle When the handle is lifted, the time required for the pressure to drop from 2.45MPa to 0.196MPa shall not exceed 2.5 seconds.

Check the intake and exhaust speed of a single chamber. The rocker arm is tilted 20-25 degrees to each side to exhaust a cylinder. The time required for the pressure to drop from 2.45MPa to 0.196MPa does not exceed 2 seconds; when the rocker arm is returned to the middle position, The pressure rises from zero to 2.35MPa in no more than 2 seconds.

(6) Second brake regulator test

Sealing test:

Add 5.88MPa air pressure from the air inlet nozzle, maintain it for 2 minutes, and check with neutral soapy water. No air leakage is allowed in the seal. Adjust the pressure of the outlet pressure gauge to 0.098MPa and 1.176MPa respectively, and maintain them for 1 minute each. No air leakage is allowed at the seal.

Performance experiment:

Add 4.9MPa air pressure from the air inlet nozzle, adjust the handle stop point, the pressure on the outlet pressure gauge is 0.98MPa, release the handle to release the air pressure of the 2L cylinder, and then quickly move the handle to the stop point, the pressure will be from 0 The time to rise to 0.931MPa does not exceed 2.2 seconds.

Adjust the pressure of the outlet pressure gauge to 0.98MPa and quickly release the handle. The time for the pressure of the 2L gas cylinder to drop from 0.98MPa to 0.049MPa should not exceed 2.2 seconds.

Constant experiment:

Adjust the second brake pressure regulator to a certain value, fix the position of the limiting screw, and press the control handle onto the limiting screw 3-4 times. The difference between the resulting pressure and the original adjusted pressure shall not exceed 0.049MPa.

Valve working accuracy experiment:

Adjust the handle stop point so that the pressure on the outlet pressure gauge is 0.784MPa. Release the handle. When the pressure drops to 0.588MPa, move the handle back to the stop point. The pressure at the outlet nozzle should not be less than 0.735MPa. Use the above method to adjust the pressure to 0.49MPa, 0.392MPa, 0.294MPa, 0.196MPa, 0.098MPa and check one by one. The pressure of the air outlet nozzle is not less than 0.735MPa.

(7)Brake distributor test

Maximum tilt angle check:

The maximum angle at which the rocker arm tilts from the neutral position to either side shall not be less than 27 degrees.

Adjust the experiment:

Place the rocker arm in the neutral position. When the rocker arm tilts no more than 5 degrees to either side, there should be no air leakage. When the rocker arm tilts to one side until the pressure drops to 0, the pressure on the other side is not allowed to drop. According to the above Method to inspect the other side of the car.

When the rocker arm tilts 14±1 degrees, the exhaust sound should be heard. At this time, the pressure should drop to 1.078MPa. According to actual work experience, it is better to adjust the rocker arm to 14-1 degrees, and the pressure at this time is 0.98MPa.

When the rocker arm tilts 16±1 degrees, the pressure should drop to 0.098MPa.

Performance experiment:

Check the inflation speed. In the case of single exhaust, the time from 0.98MPa to 0.049MPa does not exceed 2.2 seconds; in the case of double exhaust, the time from 0.98MPa to 0.049MPa does not exceed 3 seconds.

Residual gas experiment:

Adjust the outlet pressure of the second brake regulator to 0.098MPa, then quickly move the brake distributor rocker arm to check that the brake distributor should reduce the air pressure in the left and right chambers to 0.

Lightly reduce the pressure of the second brake regulator to 0.49MPa, and then move the brake distributor rocker arm to the left and right in sequence. At this time, the exhaust chamber of the brake distributor should reduce the pressure to 0.

Sealing test:

Install the brake distributor on the test fixture, block the air outlet nozzle, then add 0.196MPa and 1.176MPa air pressure respectively from the air inlet nozzle, keep each for 5 minutes, and use neutral soapy water to check the double brakes and the left and right single brakes. The sealing performance when the rocker arm is in the extreme position should not leak.

(8) Brake amplifier test

Maximum output pressure:

The air source is 4.9MPa, the air pressure of 1.05±0.05MPa is input from the second brake regulator air outlet joint, and the brake amplifier outlet pressure is 1.6±1MPa.

Intake and exhaust speed:

At the air intake speed, the outlet of the brake amplifier is connected to a 0.5L gas cylinder, and cold air is quickly input to the upper part of the pressure regulating piston. When the pressure of the cylinder at the outlet of the brake amplifier rises from 0 to 1.766MPa, the required time is ≯ 0.8 seconds.

The exhaust speed quickly eliminates the air pressure in the control chamber. When the pressure of the brake amplifier outlet cylinder drops from 1.766MPa to 0.05MPa, the required time is ≯0.8 seconds.

(9) Boost circuit test

Inflate the air pressure of 10.8-12.7MPa into the supercharger inlet pipeline, turn on the supercharger air inlet switch, and adjust the outlet pressure of the 5MPa pressure reducer to 4.9MPa through the pressure regulating switch.

Supercharger air intake:

Turn the pneumatic switch to the intake position. At this time, the air source in the intake pipeline enters the high-pressure chamber of the supercharger through the pneumatic switch and one-way valve. The intake pressure is indicated by a pressure gauge with a range of 0-10MPa.

Supercharger boost:

Quickly turn the pneumatic switch to the boosting position. At this time, the 4.9MPa air source passes through the pneumatic switch and enters the low-pressure chamber of the supercharger. The pressure in the air inlet chamber is indicated by a pressure gauge with a range of 0-10MPa. The pressure in the high-pressure chamber after supercharging by the supercharger is indicated by a pressure gauge measuring the outlet pressure with a range of 0-25MPa. The outlet pressure should be 4 times the inlet pressure, and the pressure can rise to 20MPa.

Use of supercharger booster air source:

After the test pneumatic accessory is connected to the 20MPa air outlet nozzle, open the high-pressure 20MPa air outlet switch of the boosted air source to output 0-20MPa air pressure to the tested pneumatic accessory. The output pressure is indicated by a pressure gauge with a range of 0-25MPa.

(10) Cylinder and pneumatic switch test

Cylinder test:

For the sealing test, apply air pressure from the "retract" and "release" joints respectively. The piston and external shell should be sealed.

For performance experiments, connect the cylinder retracting joint to the test bench control panel switch retracting joint, and then pull the pneumatic switch to test the cylinder performance.

Pneumatic switch test:

For the sealing test, the "retract" and "release" joints are not blocked, the switch is in the "neutral" position, add air pressure from the "incoming air" connector, and no air leakage is allowed at the "retract", "release" joints and the casing. When the rocker arm tilts 5° left and right, air leakage is still not allowed in the "retract" and "release" joints.

For performance testing, connect the cylinder retracting connector on the control panel to the pneumatic switch retracting connector, connect the cylinder retracting connector on the control panel to the pneumatic switch retracting connector, and then flip the pneumatic switch back and forth from the closed to retracted and released positions, and the cylinder retracts and releases. Flexible, no air leakage allowed anywhere.

3. Testing of pneumatic accessories of aircraft fuel ventilation and pressurization system

Since there are many pneumatic accessories in the aircraft fuel system, these accessories require sealing tests and a considerable part of them require air flow tests. In order to adapt to a larger flow test range, this application is divided into two parts: large flow and small flow, which can meet the basic requirements for routine testing of most fuel ventilation and boosting system accessories. In order to ensure higher reliability, the flow meters used in the flow test unit of this application are not direct-reading float flow meters.

When performing a flow test, you only need to connect the air outlet connector of the pneumatic accessory under test to the air inlet connector of the flow meter, and then turn on the test switch to measure the instantaneous flow rate of the gas.

The above embodiments are used to explain the present invention rather than to limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modifications and changes made to the present invention fall within the protection scope of the present invention.

Claims (10)

1. The universal test bench for the pneumatic accessories of the aircraft comprises a test bench body, wherein an operating table and an operating panel are arranged outside the test bench body, and the universal test bench is characterized in that a cold air system and an electric system are arranged in the test bench body, and the electric system is connected with the cold air system and supplies power for the cold air system;

the air conditioning system comprises a first testing unit for testing a common type pneumatic accessory, a second testing unit for testing a special type pneumatic accessory and a flow testing unit for testing the pneumatic accessory of the fuel ventilation and pressurization system of the aircraft;

the first test unit comprises a first pipeline (48) with an air inlet nozzle (1) at one end and an air outlet nozzle (35) at the other end, wherein a pressure gauge (21) with the measuring range of 0-25MPa, a 5MPa pressure reducer (4), a brake regulator (5), a cold air switch (46) and a pressure gauge (22) with the measuring range of 0-1.6MPa are sequentially arranged on the first pipeline (48) along the air outlet direction; three branch pipelines are connected to the first pipeline (48), the first branch pipeline is connected to the first pipeline (48) between the air inlet nozzle (1) and the 5MPa pressure reducer (4), and the second branch pipeline and the third branch pipeline are both connected to the first pipeline (48) between the 5MPa pressure reducer (4) and the brake regulator (5); the air outlet end of each branch pipeline is provided with an air outlet nozzle (33, 34, 36), the first branch pipeline and the second branch pipeline are sequentially provided with a cold air switch (46) and a pressure gauge (22) with the measuring range of 0-16MPa along the air outlet direction, the second branch pipeline is sequentially provided with the cold air switch (46) and the pressure gauge (23) with the measuring range of 0-10MPa along the air outlet direction, and the third branch pipeline is sequentially provided with a 0.3MPa pressure reducer (6), the cold air switch (46) and the pressure gauge (25) with the measuring range of 0-0.4MPa along the air outlet direction;

The second test unit comprises a first test loop for testing the electromagnetic cold air valve (30), a second test loop for testing the brake pressure reducing valve (26), a third test loop for testing the air release solenoid valve (47), a fourth test loop for testing the first brake pressure regulator (7) and the brake differential (8), a fifth test loop for testing the second brake pressure regulator (5) and the brake distributor (11), a sixth test loop for testing the brake amplifier (14), a seventh test loop for testing the air cylinder (44) and the air switch (27) and a pressurizing loop for increasing the air source pressure of the tested pneumatic accessories; the first test loop comprises an electromagnetic cold air switch air inlet nozzle (45) connected with the electromagnetic cold air valve (30); the seventh test circuit comprises a cylinder (44) connected to the pneumatic switch (27);

the flow test unit comprises a flow meter for testing the flow meter in the range of 16ml/min-10m ³ Small flow test loop for gas flow in/h and test range of 10-100m ³ And a high flow test loop for gas flow in/h.

2. The universal test stand for aircraft pneumatic accessories according to claim 1, wherein the first test circuit further comprises a second pipeline (49) connected with the first pipeline (48), and a third pipeline (50) connected with the third branch pipeline, and the second pipeline (49) and the third pipeline (50) are connected with an electromagnetic cold air switch air inlet nozzle (45); the second pipeline (49) is connected with a high-pressure gas cylinder (31), and an air inlet switch and a pressure gauge (22) with the measuring range of 0-16MPa are sequentially arranged on the second pipeline (49); the third pipeline (50) is connected with the low-pressure gas cylinder (32), and the third pipeline (50) is sequentially provided with an air inlet switch and a pressure gauge (23) with the measuring range of 0-10 MPa.

3. The universal test bench for aircraft pneumatic accessories according to claim 1, characterized in that the second test circuit comprises a fourth pipeline (51) connected with the first pipeline (48) and a 1.5L high-pressure cold gas cylinder (9) connected with the fourth pipeline (51), and an air inlet switch, a brake pressure reducing valve (26) and a pressure gauge (22) with a measuring range of 0-16MPa are sequentially arranged on the fourth pipeline (51).

4. The aircraft pneumatic accessory universal test stand according to claim 1, characterized in that the third test circuit comprises a fifth line (52) connected to the first line (48), a fourth branch line connected to the fifth line (52), a 0.5L low pressure gas cylinder (15) connected to the fifth line (52) and a 1L low pressure gas cylinder (13) connected to the fourth branch line; the fifth pipeline (52) is sequentially provided with a 5MPa pressure reducer (4), a pressure gauge (23) with the measuring range of 0-10MPa for measuring the air inlet pressure, an air inlet switch, an air discharge electromagnetic valve (47) and a pressure gauge (23) with the measuring range of 0-10MPa for measuring the air outlet pressure; the fourth branch pipe is connected to a fifth pipe (52) between the air intake switch and the air discharge solenoid valve (47).

5. The universal test bench for aircraft pneumatic accessories according to claim 1, characterized in that the fourth test circuit comprises a sixth pipeline (53) connected with the third branch pipeline, a fifth branch pipeline connected with the sixth pipeline (53), a 1.5L high-pressure cold gas cylinder (9) connected with the sixth pipeline (53) and a 0.75L low-pressure cold gas cylinder (10) connected with the fifth branch pipeline, wherein an air inlet switch, a first brake pressure regulator (7) and a pressure gauge (23) for measuring the range of the air outlet pressure is arranged on the sixth pipeline (53) in sequence; the fifth branch pipeline is connected to a sixth pipeline (53) of the air outlet of the first brake pressure regulator (7), and the fifth branch pipeline is sequentially provided with an air inlet switch, a brake differential (8) and a pressure gauge (23) with the measuring range of 0-10 MPa.

6. The universal test bench for aircraft pneumatic accessories according to claim 1, characterized in that the fifth test circuit comprises a seventh pipeline (54) connected with the third branch pipeline, a sixth branch pipeline connected with the seventh pipeline (54), a 2L high-pressure gas cylinder (12) connected with the seventh pipeline (54) and a 1L low-pressure gas cylinder (13) connected with the sixth branch pipeline, wherein an air inlet switch, a second brake pressure regulator (5) and a pressure gauge (23) for measuring the air outlet pressure, with the range of 0-10MPa, are sequentially arranged on the seventh pipeline (54); the sixth branch pipeline is connected to a seventh pipeline (54) of the air outlet of the second brake pressure regulator (5), and the sixth branch pipeline is sequentially provided with an air inlet switch, a brake distributor (11) and a pressure gauge (23) with the measuring range of 0-10 MPa.

7. The universal test bench for aircraft pneumatic accessories according to claim 6, characterized in that the sixth test circuit comprises an eighth pipeline (55) connected with the third branch pipeline and a 0.5L low-pressure gas cylinder (15) connected with the eighth pipeline (55), and an air inlet switch, a brake amplifier (14) and a pressure gauge (23) for measuring the range of the air outlet pressure of 0-10MPa are sequentially arranged on the eighth pipeline (55); the brake amplifier (14) is connected with the air outlet of the second brake pressure regulator (5) through a seventh branch pipeline, and an air inlet switch is arranged on the seventh branch pipeline.

8. The universal test stand for aircraft pneumatic accessories as claimed in claim 1, wherein the seventh test circuit further comprises a ninth pipeline (56) connected with the third branch pipeline and a pneumatic switch (27) connected with the ninth pipeline (56), an air inlet switch is arranged on the ninth pipeline (56), a pneumatic switch take-up nozzle (38) of the pneumatic switch (27) is connected with a cylinder take-up nozzle (40) of the cylinder (44), and a pneumatic switch take-down nozzle (39) of the pneumatic switch (27) is connected with a cylinder take-down nozzle (41) of the cylinder (44).

9. The universal test bench for aircraft pneumatic accessories according to claim 1, characterized in that the pressurizing circuit comprises a tenth pipeline (57) connected with the first pipeline (48), an air outlet nozzle (37) is arranged at the air outlet end of the tenth pipeline (57), and a 5MPa pressure reducer (4), an air inlet switch, a pressure gauge (23) with the measuring range of 0-10MPa, a pneumatic switch (27), a supercharger (29), a pressure gauge (21) with the measuring range of 0-25MPa for measuring the air outlet pressure of the supercharger, an air outlet switch and a pressure gauge (21) with the measuring range of 0-25MPa for measuring the output pressure are arranged on the tenth pipeline (57); the pneumatic switch lowering nozzle of the pneumatic switch (27) is connected with the low-pressure cavity of the supercharger (29) through a pipeline, and the pneumatic switch collecting nozzle of the pneumatic switch (27) is connected with the high-pressure cavity of the supercharger (29) through a pipeline provided with a one-way valve (28).

10. The universal test stand for aircraft pneumatic accessories as claimed in claim 1, wherein the low flow test circuit comprises an inlet end provided with an inlet nozzle (42) and a pressure gauge (24) with a measuring range of 0-1.6MPaThe air inlet pipeline is connected with a plurality of flowmeters for testing different flow rates, the measuring range of each flowmeter is different, and a test switch is arranged on the air inlet pipeline between a pressure gauge (24) with the measuring range of 0-1.6MPa and each flowmeter; the large-flow test loop comprises an air inlet pipeline, the air inlet end of which is provided with an air inlet nozzle (43) and a pressure gauge (24) with the measuring range of 0-1.6MPa, and the air inlet pipeline is connected with a measuring range of 10-100m ³ And a test switch is arranged between the flowmeter (20) and the pressure gauge (24) with the measuring range of 0-1.6 MPa.