Verification method for spacecraft closed cavity process hole plugging measures

Abstract

The present application relates to the field of aerospace technology, and more particularly to a method for verifying a sealing measure for a process hole of a closed cavity of a spacecraft, wherein the method abandons conventional vacuum extraction and direct pressurization, uses a sealed tank as a transition container, slowly provides a high-pressure environment for the sealed test piece, slowly changes the pressure of the test piece to the high-pressure environment, and then sets a time according to the test requirements to release the pressure and check whether there is any leakage at the sealing position, thereby avoiding the problems of direct and rapid pressurization damaging the sealing structure and slow and direct pressurization failing to reach the required pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace technology, and in particular to a method for verifying a process hole measure of a closed cavity of a spacecraft. BACKGROUND

[0002] In order to reduce the mass of the aerospace structure to reduce the launch cost, materials with high specific stiffness are generally used, such as titanium alloy, magnesium-aluminum alloy, and carbon fiber, etc. In some cases, in order to enhance the support stiffness and efficiency of the structure, a closed structure design is used. Considering the pressure difference between the ground and the space environment and the mechanical process, the closed structure needs to reserve a process hole. Because the aerospace load will be discharged within a few minutes during the launch process, the pressure in the closed space will be close to 0 from 1 atmosphere, and the excess material in the closed hole will be leaked. In addition, in the orbit operation in the microgravity environment, the excess material may also be leaked. Such a situation is prohibited during the operation of the aerospace load.

[0003] In order to prevent the leakage of excess material, it is necessary to implement plugging measures for the closed cavity in advance and verify the plugging effect. According to the traditional process of the existing experimental method, a vacuum pump is used to vacuum the sealed container. For a vacuum discharge experiment, in order to simulate the discharge process in the launch stage, the vacuum degree of the sealed container needs to reach 1.3x10 -3 pa within a few minutes. To meet this requirement, ordinary vacuum pumps cannot meet the above requirements, and additional experimental costs are needed to meet the requirements. SUMMARY

[0004] The method for verifying the plugging of the process hole of the closed cavity of the spacecraft provided by the present application specifically includes the following steps:

[0005] S1, clean the stainless steel sealed tank with a dust-free cloth and alcohol, and confirm that the inside of the stainless steel sealed tank is dry and clean;

[0006] S2, perform plugging operation on the test piece;

[0007] S3, clean the outer surface of the test piece after plugging and place it in the stainless steel sealed tank; after confirming that the test piece after plugging and the stainless steel sealed tank are free of surface excess dust, close the stainless steel sealed tank;

[0008] S4, connect the filtered gas source and the inflation pressure gauge into the gas inlet nozzle of the stainless steel sealed tank, and inject pressure into the stainless steel sealed tank, so that the internal pressure of the test piece after plugging is consistent with the internal pressure of the stainless steel sealed tank;

[0009] S5, use the air release valve of the stainless steel sealed tank to discharge air, so that the internal pressure of the test piece after plugging is consistent with the atmospheric pressure;

[0010] S6, open the stainless steel sealing tank, and check whether there is leakage of excess material on the inside of the stainless steel sealing tank and the surface of the plugged test piece.

[0011] Further, the plugging operation of step S2 specifically comprises the following steps:

[0012] S21, fill micron-sized diamond sand into the inside of the test piece with the air hole;

[0013] S22, smear a small amount of GD414 glue around the air hole, so that the polytetrafluoroethylene filter screen covers and adheres to the air hole;

[0014] S23, press the polytetrafluoroethylene adhesive tape after punching and length fixing to the polytetrafluoroethylene filter screen, so as to completely fix the polytetrafluoroethylene filter screen to the test piece;

[0015] S24, apply GD414 glue on the four corner points of the polyimide adhesive tape, so as to prevent the polyimide adhesive tape from falling off when the test piece is running on the track.

[0016] Further, the diameter of the polytetrafluoroethylene filter screen is greater than the diameter of the air hole.

[0017] Compared with the prior art, the application can achieve the following beneficial effects:

[0018] The application uses pressurization instead of a vacuum pump to replace the vacuumization of the sealed container, and the experiment is simple and efficient, and can more easily achieve full coverage of the experiment air release time; and the sealing tank is set as a transition container to provide a high-pressure environment for the test piece slowly, avoiding the problems that direct rapid pressurization will damage the plugging structure and slow direct pressurization cannot reach the required pressure of the test. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a flow chart of a verification method of a spacecraft closed cavity process hole plugging measure according to an embodiment of the application;

[0020] Figure 2 is an example structure diagram of a verification method of a spacecraft closed cavity process hole plugging measure according to an embodiment of the application;

[0021] Figure 3 is a flow chart of a spacecraft closed cavity process hole plugging method according to an embodiment of the application;

[0022] Figure 4 is a plugging structure schematic diagram of a spacecraft closed cavity process hole plugging according to an embodiment of the application.

[0023] The drawings show that: the test piece 1, the GD414 glue 2, the polytetrafluoroethylene filter screen 3, the polyimide adhesive tape 4, the stainless steel sealing tank 5, the air inlet nozzle 6, and the air release valve 7. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not constitute a limitation on the present application.

[0025] The verification method of the spacecraft closed cavity process hole plugging measure provided by the present application discards the conventional vacuum extraction method and the direct pressurization method, uses a sealed tank as a transition container to provide a high-pressure environment for a test piece, slowly changes the pressure of the test piece to the high-pressure environment, and then releases the pressure and checks whether there is excess leakage at the plugging position.

[0026] Figure 1 and Figure 2 The flow of the verification method of the spacecraft closed cavity process hole plugging measure provided by the embodiments of the present application and an example structure of the verification method are shown respectively.

[0027] As shown in Figure 1 and Figure 2 The verification method of the spacecraft closed cavity process hole plugging measure provided by the embodiments of the present application specifically includes the following steps:

[0028] S1, clean the stainless steel sealed tank 5 using a dust-free cloth and alcohol, and confirm that the inside of the stainless steel sealed tank 5 is dry and clean.

[0029] S2, perform plugging operation on the test piece 1 according to the above plugging method.

[0030] S3, clean the outer surface of the plugged test piece 1 and place it in the stainless steel sealed tank 5; after confirming that the plugged test piece 1 and the stainless steel sealed tank 5 have no surface excess dust, close the stainless steel sealed tank 5.

[0031] S4, connect the filtered gas source and the inflation pressure gauge into the air inlet nozzle 6 of the stainless steel sealed tank 5, inject 0.25mpa pressure into the stainless steel sealed tank 2, wait for 5min, and make the internal pressure of the plugged test piece 1 consistent with the internal pressure of the stainless steel sealed tank 5.

[0032] S5, use the air release valve 7 of the stainless steel sealed tank 5 to release air, and after releasing air, stand for 5min to make the internal pressure of the plugged test piece 1 consistent with the atmospheric pressure.

[0033] S6, open the stainless steel sealed tank 5, and check whether there is excess leakage at the inside of the stainless steel sealed tank 5 and the surface of the plugged test piece 1.

[0034] Figure 3 and Figure 4The flow of the spacecraft closed cavity process hole plugging method and the structure of the closed cavity provided by the embodiment of the application are shown respectively.

[0035] As shown in Figure 3 and Figure 4 , the plugging method of step S2 specifically includes the following steps:

[0036] S21, micron-sized diamond sand is filled into the inside of the test piece 1 with the air hole left.

[0037] S22, a small amount of GD414 glue 2 is smeared around the air hole, so that the polytetrafluoroethylene filter screen 3 covers and sticks to the air hole.

[0038] The diameter of the polytetrafluoroethylene filter screen 3 is greater than the diameter of the air hole.

[0039] S23, the polytetrafluoroethylene adhesive tape 4 after punching and lengthening is pressed to the polytetrafluoroethylene filter screen 3, so that the polytetrafluoroethylene filter screen 3 is completely fixed to the test piece 1.

[0040] S24, GD414 glue 2 is applied to the four corner points of the polyimide adhesive tape 4, which is used to prevent the polyimide adhesive tape 4 from falling off when the test piece 1 is in orbit.

[0041] It should be understood that the various forms of the flow shown above can be used to reorder, add or delete steps. For example, the steps described in the present disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions of the present disclosure can be achieved, which are not limited herein.

[0042] The above specific embodiments do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A verification method for sealing process holes in a spacecraft enclosed cavity, characterized in that, Specifically comprising the following steps: S1, cleaning the stainless steel sealed tank with a dust-free cloth and alcohol, and confirming that the inside of the stainless steel sealed tank is dry and clean; S2, sealing the test piece; The sealing operation of step S2 specifically comprises the following steps: S21, filling micron-sized corundum into the inside of the test piece with a gas permeation hole; S22, applying a small amount of GD414 glue around the gas permeation hole to cover and paste the polytetrafluoroethylene filter screen on the gas permeation hole; S23, pressing the polytetrafluoroethylene filter screen with the polytetrafluoroethylene adhesive tape punched and fixed in length to completely fix the polytetrafluoroethylene filter screen and the test piece; S24, applying GD414 glue on the four corner points of the polytetrafluoroethylene adhesive tape to prevent the polytetrafluoroethylene adhesive tape from falling off when the test piece is running on the track; S3, cleaning the outer surface of the sealed test piece and placing it in the stainless steel sealed tank; after confirming that the surface of the sealed test piece and the stainless steel sealed tank is free of excess dust, closing the stainless steel sealed tank; S4, connecting the filtered gas source and the inflation pressure gauge into the air inlet nozzle of the stainless steel sealed tank, and injecting pressure into the stainless steel sealed tank to make the internal pressure of the sealed test piece consistent with the internal pressure of the stainless steel sealed tank; S5, using the air release valve of the stainless steel sealed tank to release air to make the internal pressure of the sealed test piece consistent with the atmospheric pressure; S6, opening the stainless steel sealed tank and checking whether there is excess leakage in the inside of the stainless steel sealed tank and the surface of the sealed test piece.

2. The method of verifying a spacecraft closed volume process port closure of claim 1, wherein, The diameter of the polytetrafluoroethylene filter screen is greater than the diameter of the gas permeation hole.

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