A method for air and water tightness test of an aircraft internal water storage structure before installation

Abstract

The application belongs to the technical field of aircraft production test, and specifically discloses a method for air-tight and water-tight test of an aircraft internal water storage structure before installation, which comprises the following processes: air-tight strength test is performed on a single water storage structure, when the air-tight strength test is passed, a second-stage air-tight test is performed, when the second-stage air-tight test is performed, air is filled into the water storage structure to a certain pressure, then air supply is stopped and the pressure in the water storage structure is continuously recorded; when the second-stage air-tight test is passed, a water-tight test is performed; when the water-tight test is passed, a pure air-tight test is performed. The test method can quickly verify the water-tightness and air-tightness of the water storage structure before installation, greatly reduces the risk of structure damage, production cycle and transportation cost, and has practicality and engineering research and development significance.

Description

Technical Field

[0001] This invention belongs to the field of aircraft production testing technology, specifically relating to a method for airtight and watertight testing of an internal water storage structure before its installation. Background Technology

[0002] Due to the frequent occurrence of forest fires and the weakness of aerial firefighting capabilities, a special-purpose fixed-wing aircraft equipped with a water storage structure can supplement the existing forest aviation firefighting equipment system and rapidly increase aerial firefighting capabilities.

[0003] The water storage structure, comprising a thin-walled water tank and piping, is installed inside the aircraft fuselage. This structure isolates the atmosphere from the aircraft cabin. Due to cabin pressurization, the outer surface of the water storage structure bears the airtight load of the cabin, while the inner surface bears the pressure and overload of the water. Therefore, the water storage structure must meet the requirements of not being damaged under airtight loads, ensuring the airtightness and strength of the aircraft cabin, and preventing water from leaking into the cabin through the surface of the water storage structure.

[0004] If the aircraft water storage structure is directly transported to the main engine plant for assembly on a test aircraft after being manufactured by the supplier, damage to the water storage structure under airtight loads could damage the test aircraft, resulting in significant losses. Furthermore, conducting airtightness tests along with the test aircraft requires a large and expensive experimental setup to accommodate the entire test aircraft containing the water storage structure. However, if the airtightness, airtightness strength, and watertightness of the water storage structure are not verified before installation, and these defects are found after assembly into mass-produced aircraft, the structure must be returned to the supplier for modification, significantly extending the production cycle, increasing transportation costs, raising labor costs, and increasing the risk of structural damage. Therefore, inventing a method for airtightness testing of the water storage structure before installation has significant engineering research and development value. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide a method for testing the airtightness and watertightness of an aircraft's internal water storage structure before installation. This invention requires relatively small testing equipment, incurs low costs, and is easy to implement.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for conducting airtightness and watertightness tests on an aircraft's internal water storage structure before installation includes the following steps:

[0008] An airtightness test is conducted on a single water storage structure. After the airtightness test is passed, a second-stage airtightness test is conducted. During the second-stage airtightness test, the water storage structure is pressurized with air, the air supply is stopped, and the pressure inside the water storage structure is continuously recorded. After the second-stage airtightness test is passed, a watertightness test is conducted.

[0009] After the watertightness test is passed, the airtightness test is carried out.

[0010] Preferably, a single water storage structure includes a water storage tank, which is provided with a filling port, a connecting pipe, a drain outlet, and an air replenishment overflow channel that communicate with the inner cavity of the water storage tank. The air replenishment overflow channel is located at the top of the water storage tank, and the connecting pipe and the drain outlet are located at the bottom of the water storage tank. The connecting pipe is used to connect with the connecting pipes of other water storage structures.

[0011] Preferably, one water storage structure is selected from those with the same structure and that have passed the watertightness test for a pure airtightness test. The pure airtightness test process includes:

[0012] Seal the connecting pipes, drain outlet, and air replenishment overflow channel on the water storage tank. Pump air into the inner cavity of the water storage tank through the filling port to the first preset pressure. Check the airtightness of the water storage structure under the first preset pressure. If the water storage structure is intact under the first preset pressure, it indicates that the water storage structure has passed the pure airtightness test.

[0013] Preferably, the first preset pressure is the pure airtight pressure value of the aircraft cabin. If the water storage structure is still intact after maintaining the first preset pressure for 3 seconds, it indicates that the pure airtightness test of the water storage structure has been passed.

[0014] Preferably, the process of conducting an airtightness strength test on a single water storage structure includes:

[0015] Seal the connecting pipes, drain outlet, and air filling overflow channel on the water storage tank. Inflate the water storage tank to the second preset pressure through the filling port. Check the bulging and sound of the water storage structure under the second preset pressure. If there is no obvious bulging or sound of the water storage structure under the second preset pressure, release the pressure and check the deformation of the water storage structure. If there is no permanent deformation, cracks, or air leakage, it indicates that the water storage structure has passed the air tightness strength test.

[0016] Preferably, the second preset pressure is the airtightness value of the aircraft.

[0017] Preferably, when air is added to the water storage tank through the filling port, the pressurization rate is controlled at 35Pa / s-50Pa / s.

[0018] Preferably, the process during the second stage of the airtightness test includes:

[0019] Seal the connecting pipes, drain outlets, and air replenishment overflow channels on the water storage tank. Inflate the water storage tank through the filling port to the required airtight pressure value of the water storage structure, then stop the air supply and continuously record the air pressure changes. When the air pressure change in the water storage structure is within the preset range, it indicates that the water storage structure has passed the second stage airtightness test.

[0020] Preferably, the process of conducting a watertightness test on the water storage structure includes:

[0021] Seal the drain outlet and connecting pipe of the water storage structure, and fill the water tank with water through the filling port. Stop filling the water when the water level reaches the vertical section of the air filling overflow channel. Then fill the air filling overflow channel with air and pressurize it to the third preset pressure value for testing. Check whether there is any water leakage in the water storage structure. If there is no water leakage, it means that the water storage structure has passed the water tightness test.

[0022] Preferably, the third preset pressure value is the aircraft overload pressure;

[0023] After pressurizing to the third preset pressure value, stop water injection and let it stand for ten minutes to check for leaks on the outside of the water storage structure.

[0024] The present invention has the following beneficial effects:

[0025] The airtightness and watertightness testing method for the aircraft's internal water storage structure before installation, as described in this invention, involves conducting airtightness strength tests, second-stage airtightness tests, watertightness tests, and pure airtightness tests on a single water storage structure. The required testing equipment is relatively simple. Compared to installing the water storage structure into a testing machine and conducting airtightness tests along with the machine, this significantly reduces the size of the testing equipment and effectively avoids the risk of damage to the testing machine if the water storage structure fails to meet airtightness standards during the airtightness test. Furthermore, using the above-mentioned technical solution of this invention, the airtightness of the aircraft's internal water storage structure can be tested before installation. Suppliers do not need to repeatedly transport the structure for testing, avoiding time and cost losses during transportation, greatly reducing testing risks, and making it highly practical. Attached Figure Description

[0026] Figure 1 A schematic diagram of the installation structure for the water storage structure inside the aircraft.

[0027] Figure 2 This is a schematic diagram of an embodiment of the airtightness and watertightness test method for the internal water storage structure of an aircraft before installation.

[0028] In the diagram: 1-Fuse structure; 2-Water storage structure; 2-1-Drain outlet; 2-2-Connecting pipe; 2-3-Air replenishment overflow channel; 3-Injection port; 41-Drain outlet plug; 42-Air replenishment overflow channel plug; 43-Pipe plug. Detailed Implementation

[0029] The invention will now be further described with reference to the accompanying drawings.

[0030] See Figure 1 and Figure 2Each water storage structure 2 includes a water storage tank. The water storage tank is provided with a filling port 3, a connecting pipe 2-2, a drain outlet 2-1, and an air replenishment overflow channel 2-3 that communicate with the inner cavity of the water storage tank. The air replenishment overflow channel 2-3 is located at the top of the water storage tank, and the connecting pipe 2-2 and the drain outlet 2-1 are located at the bottom of the water storage tank. The connecting pipe 2-2 is used to connect with the connecting pipes 2-2 of other water storage structures 2. Multiple water storage structures 2 can be connected through the connecting pipes 2-2 to form the water storage structure of the entire aircraft.

[0031] See Figure 1 and Figure 2 The airtightness and watertightness test method for the aircraft internal water storage structure before installation of the present invention specifically includes the following steps:

[0032] Step 1: Conduct an airtightness test. Use drain plug 41 to seal the drain outlet 2-1 at the bottom of the water storage structure 2, and use drain plug 42 to seal the air replenishment overflow channel 2-3 at the top of the water storage structure 2. Connect the air inlet hose to the filling port 3, and then slowly inflate the water storage structure 2 to the aircraft's airtightness of 35 kPa. Control the pressurization rate at 35 Pa / s-50 Pa / s, and stop the air supply after maintaining this for 6 minutes.

[0033] Step 2: When the air tightness test is pressurized to the aircraft's air tightness strength of 35 kPa, there should be no obvious bulging or noise. After the pressure is released, check the water storage structure 2 to see if there is any permanent deformation or crack. At the same time, check and record any obvious leaks and eliminate them to create conditions for subsequent tests.

[0034] Step 3: Conduct the second stage airtightness test. Ensure that the drain outlet 2-1 and connecting pipe 2-2 at the bottom of the water storage structure 2 and the air replenishment overflow channel 2-3 at the top have been sealed with the drain outlet plug 41 and the air replenishment overflow channel 42, respectively. Pressurize the inside of the water storage structure 2 to the airtightness pressure requirement value of 30 kPa, then stop the air supply and continuously record the air pressure changes.

[0035] Step 4: Conduct a watertight test. Seal the lower opening of the water storage structure 2 using the drain plug 41. Connect the external water supply device to the filling port 3 on the water storage structure 2 and fill with water at the set speed, ensuring the water level reaches the vertical section of the upper air overflow channel 2-3 of the water storage structure 2. After filling with water, connect the external air source device to the upper air overflow channel 2-3 of the water storage structure 2 and pressurize it to the aircraft overload pressure of 10 kPa for testing.

[0036] Step 5: After the water level of the watertight test reaches the target position, stop the water injection and let it stand for ten minutes. Observe whether there is any leakage on the outside of the water storage structure. Record the leakage points and eliminate them after the test.

[0037] Step Six: Select one water storage structure 2 of the same structure for a pure airtightness test. Use the drain plug 41 to seal the lower opening of the water storage structure 2 (i.e., drain 2-1 and connecting pipe 2-2), use the air filling overflow channel plug 42 to seal the upper air filling overflow channel 2-3 of the water storage structure 2, and use the pipe plug 43 to seal all the connecting pipes 2-2 at the bottom of the water storage structure 2. Connect the air pump to the filling port 3 on the structure 21 and pump the pressure inside the water storage structure 2 to the pure airtightness of 69 kPa in the aircraft cabin. If the water storage structure 2 remains intact for 3 seconds, it indicates that the water storage structure 2 has passed the pure airtightness test.

[0038] In the above-described scheme of the present invention, the air used in the airtightness test must be filtered clean to prevent the ingress of moisture and oil, and the watertightness test must use clean domestic water.

[0039] As can be seen from the above scheme, the method of the present invention can be used to conduct watertight and airtight tests on the internal water storage structure of the aircraft before installation, which greatly reduces the risk of structural damage, production cycle and transportation cost, and has strong practicality.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for conducting airtightness and watertightness tests on an aircraft's internal water storage structure before installation, characterized in that... The process includes the following: An airtightness test was conducted on a single water storage structure (2). After the airtightness test was passed, a second-stage airtightness test was conducted. During the second-stage airtightness test, the water storage structure (2) was pressurized with air and the air supply was stopped while the pressure inside the water storage structure (2) was continuously recorded. After the second-stage airtightness test was passed, a watertightness test was conducted. After the water tightness test is passed, the pure air tightness test is carried out. A single water storage structure (2) includes a water storage tank, which is provided with a filling port (3), a connecting pipe (2-2), a drain outlet (2-1), and an air replenishment overflow channel (2-3) that are connected to the inner cavity of the water storage tank. The air replenishment overflow channel (2-3) is located at the top of the water storage tank, and the connecting pipe (2-2) and the drain outlet (2-1) are located at the bottom of the water storage tank. The connecting pipe (2-2) is used to connect with the connecting pipes (2-2) of other water storage structures (2). One water storage structure (2) with the same structure and that has passed the watertightness test is selected for a pure airtightness test. The pure airtightness test process includes: The connecting pipe (2-2), drain (2-1) and air filling overflow channel (2-3) on the water storage tank are all sealed. Air is drawn into the inner cavity of the water storage tank through the filling port (3) to the first preset pressure. The air tightness of the water storage structure (2) is checked under the first preset pressure. If the water storage structure (2) is intact under the first preset pressure, it indicates that the water storage structure (2) has passed the pure air tightness test. The process of conducting an airtightness test on a single water storage structure (2) includes: Seal the connecting pipe (2-2), drain (2-1) and air filling overflow channel (2-3) on the water storage tank. Fill the water storage tank with air through the filling port (3) to the second preset pressure. Check the bulging and sound of the water storage structure (2) under the second preset pressure. If the water storage structure (2) does not bulge or make a sound under the second preset pressure, release the pressure and check the deformation of the water storage structure (2). If there is no permanent deformation, cracks or air leakage, it indicates that the water storage structure (2) has passed the air tightness strength test. The process during the second phase of the airtightness test includes: The connecting pipe (2-2), drain (2-1) and air filling overflow channel (2-3) on the water storage tank are all sealed. Air is filled into the water storage tank through the filling port (3) until the airtightness pressure requirement of the water storage structure (2) is reached, and then the air supply is stopped. The air pressure change is continuously recorded. When the air pressure change in the water storage structure (2) is within the preset range, it indicates that the water storage structure (2) has passed the second stage airtightness test. The process of conducting a watertight test on the water storage structure (2) includes: Seal the drain outlet (2-1) and connecting pipe (2-2) of the water storage structure (2), and fill the water tank with water through the filling port (3). Stop filling the water when the water level reaches the vertical section of the air filling overflow channel (2-3). Then fill the air filling overflow channel (2-3) with air and pressurize it to the third preset pressure value to test and check whether the water storage structure (2) has any leakage. If there is no leakage, it means that the water storage structure (2) has passed the water tightness test.

2. The method for airtightness and watertightness testing of an aircraft internal water storage structure before installation, as described in claim 1, is characterized in that... The first preset pressure is the pure airtight pressure value of the aircraft cabin. If the water storage structure (2) is still intact after maintaining the first preset pressure for 3 seconds, it indicates that the pure airtight test of the water storage structure (2) has been passed.

3. The method for airtightness and watertightness test of an aircraft internal water storage structure before installation according to claim 1, characterized in that, The second preset pressure is the airtightness value of the aircraft.

4. The method for airtightness and watertightness test of an aircraft internal water storage structure before installation according to claim 1, characterized in that, When filling the water tank with air through the filling port (3), the pressurization rate is controlled at 35Pa / s-50Pa / s.

5. The method for airtightness and watertightness test of an aircraft internal water storage structure before installation according to claim 1, characterized in that, The third preset pressure value is the aircraft overload pressure. After pressurizing to the third preset pressure value, stop water injection and let it stand for ten minutes to check for water leakage on the outside of the water storage structure (2).

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