A method for sealing complex joint surfaces of an aero-piston engine

Abstract

The application discloses a kind of aviation piston engine complex joint surface glue sealing method, it is related to aviation piston engine assembly technical field.For solve the problems such as high porosity of existing manual gluing process, interface bonding strength is insufficient, high-altitude low-pressure condition is easy to leak, the core process of the present application is: after preheating to the connected piece with complex joint surface, coating sealant and leveling glue surface, after installing fastening screw, complete initial pre-tightening with rated torque 5~15%, realize interface bubble diffusion to colloid by constant temperature preservation, then high temperature low pressure environment is extracted in glue bubble, after normal temperature standing, sealant is solidified, and secondary pre-tightening is completed to rated torque to complete assembly.The application greatly reduces the porosity of glue layer, improves sealing reliability and high-altitude environmental adaptability, and adapts to the manual gluing scene of aviation piston engine multi-variety small-batch production and maintenance.

Description

Technical Field

[0001] This invention relates to the field of aviation piston engine assembly technology, and specifically to a method for applying adhesive to seal complex mating surfaces of aviation piston engines. Background Technology

[0002] With the rapid development of the low-altitude general aviation industry, aero-engine piston engines, with their core advantages of compact structure, high power-to-weight ratio, and convenient maintenance, have been widely used and promoted in small general aviation aircraft, drones, and other aviation equipment. High power-to-weight ratio has always been a core objective in aerospace product design. However, due to the current rapid development of China's aero-engine piston industry, products are characterized by multi-variety, small-batch production. The overall structural design tends to be compact and integrated, resulting in irregular, wide-body, discontinuous, and complex joint surfaces for assembly and maintenance. A standardized, fully automated mass production assembly system has not yet been formed. Regular and standardized maintenance is crucial for ensuring the reliability of such aero-engines. To balance the flexibility of production assembly and after-sales maintenance, highly automated adhesive application equipment has significant limitations in this scenario. Therefore, manual adhesive application will remain the mainstream process for sealing complex joint surfaces of aero-engine piston engines for a considerable period of time.

[0003] The sealing performance of the engine housing's mating surfaces directly determines the overall reliability and service life of the engine. Current sealing processes using manual application of sealant generally suffer from insufficient sealing reliability. The core defects are: First, manual application easily leads to uneven sealant application and poor surface morphology. For complex mating surfaces with single-connected areas, grooves exceeding 1mm in size, and pores, the sealant cannot effectively fill them, resulting in high porosity after curing. This leads to significant differences in the bonding force between the two mating surfaces and the sealant, and insufficient effective contact area between the sealant and one side of the mating surface, easily forming continuous voids within the sealant layer. Second, during manual application and assembly, air bubbles are easily trapped at the interface between the sealant and the mating surfaces. Current processes cannot effectively eliminate these bubbles, especially... Under extreme low-pressure conditions at high altitudes and high altitudes, air bubbles in the adhesive layer will expand, directly causing the sealing surface to fail, leading to lubricant leakage and insufficient lubrication of internal moving parts of the engine. Prolonged operation will cause a major safety malfunction such as in-flight shutdown. Thirdly, in the existing conventional cold assembly process, the ultra-smooth joint surface has insufficient storage capacity for sealant, and the bonding strength between the sealant and the joined surface is low. At the same time, the pre-tightening assembly process is unreasonable, which further aggravates the batch-to-batch differences in the sealing performance of the joint surface. Leakage problems will not only affect the appearance quality of the product, but also cause pollution and damage to other precision control components inside the engine, seriously restricting the overall operational reliability and environmental adaptability of the aero piston engine.

[0004] Current technologies for sealing aero-engine mating surfaces primarily focus on optimizing automated adhesive application equipment or improving sealant formulations for regular planar mating surfaces. They fail to address the complex manual adhesive application scenarios of aero-engine piston engines, thus failing to fundamentally solve the industry pain points of high adhesive porosity, insufficient interfacial bonding, and easy leakage under high-altitude, low-pressure conditions caused by manual adhesive application. (Invention Content) In view of this, the present invention provides a method for sealing complex mating surfaces of aero-piston engines by applying adhesive, which addresses the problems of high porosity of the adhesive layer, insufficient interfacial bonding, and easy leakage under high-altitude and low-pressure conditions in existing adhesive application processes.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for sealing complex mating surfaces of an aero-piston engine using adhesive, the method being used for sealing and assembling complex mating surfaces between a first connected component and a second connected component, wherein the first connected component and the second connected component are locked together by fastening screws, and includes the following steps: Step S1: Preheat the first and second connected parts to make the overall temperature field of the two connected parts uniform. Step S2: Apply sealant to the complex joint surfaces of the first and second connected parts after preheating, and smooth the coated surface. Step S3: Align the first and second connected parts coated with sealant into the assembly box so that their complex mating surfaces fit precisely. Install all the fastening screws used to fasten the two connected parts and apply an initial pre-tightening torque to all the fastening screws. The initial pre-tightening torque is 5% to 15% of the rated pre-tightening torque of the fastening screws. This completes the initial pre-tightening assembly. Step S4: Place the pre-tightened assembly in a constant temperature environment of 75℃~85℃ and keep it still to allow the air bubbles sealed at the interface between the complex joint surface and the sealant to diffuse into the interior of the sealant. Step S5: Place the assembled body after heat preservation in a high temperature and low pressure environment of 75℃~85℃ and absolute pressure of 100Pa~200Pa to release the air bubbles inside the sealant and improve the density of the sealant. Step S6: Place the assembly that has undergone high temperature and low pressure treatment in a normal temperature and pressure environment to cool and stand, allowing the sealant to fully cure and solidify. Step S7: Apply the rated preload torque to the fastening screws on the assembly after the sealant has cured to complete the secondary preload assembly.

[0006] Further, in step S1, the preheating treatment specifically involves placing the first and second connected components in an insulated box and heating them at a temperature controlled between 80°C and 100°C for at least 30 minutes, until the temperature fields of the two connected components are uniform. This preheating treatment improves the interfacial wettability between the connected components and the sealant, mitigating the problems of insufficient sealant flow and weak adhesion to the joint surface during cold assembly at room temperature. It also avoids uneven curing defects caused by temperature differences between the connected components and the sealant after assembly.

[0007] Furthermore, prior to step S1, the surface roughness of the complex mating surfaces of the first and second connected components is controlled to Ra3.2. Precise control of the mating surface roughness effectively increases the amount of sealant stored in the complex mating surfaces, significantly improves the effective contact area between the sealant and the complex mating surfaces, enhances the bonding strength between the sealant and the mating surfaces, and solves the problems of insufficient sealant storage capacity and easy delamination of the sealant layer in ultra-smooth mating surfaces.

[0008] Furthermore, the sealant applied in step S2 is an anaerobic sealant, specifically SI5930 anaerobic sealant or Loctite 577 anaerobic sealant. The aforementioned anaerobic sealant can achieve stable curing in an oxygen-isolated environment, making it suitable for sealing the joint surfaces of aero-engine housings. It possesses excellent resistance to high and low temperatures, media, and vibration, and exhibits excellent compatibility with the process flow of this invention.

[0009] Furthermore, the adhesive surface smoothing treatment in step S2 specifically involves: smoothing out single-connected areas, grooves or holes with feature dimensions exceeding 1mm on the adhesive surface after application, ensuring a uniform adhesive surface on the complex mating surfaces of the first and second connected components. This adhesive surface smoothing treatment eliminates localized defects on the adhesive surface caused by manual application, ensuring a uniform adhesive layer thickness after assembly, avoiding internal porosity defects in the adhesive layer due to insufficient local adhesive application or grooves and holes, and improving sealing consistency.

[0010] Furthermore, in step S3, the initial pre-tightening torque applied to the fastening screw is 10% of the rated pre-tightening torque of the fastening screw. By using a low initial pre-tightening torque, a uniform and stable extrusion force can be provided to the adhesive layer, ensuring that the sealant is evenly spread in complex joint surfaces without being over-extended due to excessive pre-tightening force. At the same time, it provides stable pressure conditions for interfacial bubbles to diffuse into the interior of the adhesive.

[0011] Furthermore, in step S4, the temperature of the constant temperature environment is controlled at 80℃, and the holding time is no less than 2 hours. By holding at a constant temperature, the fluidity of the sealant can be further improved, allowing air bubbles trapped at the interface between the joint surface and the sealant during the assembly process to diffuse fully and evenly into the sealant body, avoiding adhesion failure caused by air bubbles concentrating at the interface, and laying the foundation for the subsequent air bubble exudation process.

[0012] Furthermore, in step S5, the temperature of the high-temperature, low-pressure environment is controlled at 80℃, the absolute pressure is controlled at 133Pa, and the standing time is no less than 4 hours. Through high-temperature, high-vacuum, and low-pressure environment treatment, air bubbles diffused into the colloid can be quickly and fully expelled from the sealant, significantly reducing the overall gas content and porosity of the cured adhesive layer, and significantly improving the density and structural strength of the colloid. This fundamentally solves the problem of sealing failure caused by air bubble expansion within the adhesive layer under high-altitude, low-pressure conditions.

[0013] Furthermore, in step S6, the temperature of the ambient temperature and pressure environment is controlled between 15℃ and 25℃, and the cooling and settling time is no less than 4 hours. By slowly cooling and settling under ambient temperature and pressure, the sealant can be fully cured and formed in a stable environment, avoiding defects such as stress concentration in the adhesive layer and cracking at the bonding interface caused by sudden temperature changes, thus ensuring the long-term stability of the sealing structure.

[0014] Furthermore, in step S2, after the first and second connected components are removed from the insulation box, the total time for applying sealant to the complex joint surfaces does not exceed 2 minutes. Strictly controlling the application time prevents a significant drop in temperature of the connected components during the application process, ensuring that the connected components remain within the preheated temperature range throughout the application process. This maintains the sealant's good flowability and interfacial wettability, ensuring stable application quality.

[0015] The beneficial effects of this invention are as follows: This invention constructs a complete process closed loop through systematic optimization of the entire process, specifically addressing the core pain points of manual gluing in complex mating surfaces of aero-piston engines. It retains the flexibility of manual gluing in multi-variety, small-batch production and after-sales maintenance scenarios, while fundamentally eliminating the defects of high adhesive porosity, insufficient interfacial bonding strength, and poor batch consistency caused by manual gluing. It can achieve a significant improvement in sealing performance without the need for high investment in automated equipment, and has extremely strong process compatibility and engineering practicality.

[0016] This invention effectively improves the interfacial wettability between the sealant and complex joint surfaces through the synergistic combination of preheating treatment of the connected parts, precise control of the roughness of the joint surface, and smoothing of the adhesive surface. It significantly increases the effective contact area and bonding strength between the sealant and the joint surface, solving the problems of insufficient adhesive bonding force, poor adhesive storage capacity of ultra-smooth surface, and insufficient filling of adhesive layer in complex structures in conventional cold assembly processes. At the same time, it eliminates the initial defects such as grooves and holes on the adhesive surface caused by manual application of adhesive, ensuring the uniformity and continuity of the adhesive layer.

[0017] This invention achieves efficient step-by-step treatment of air bubbles within the adhesive layer through a staged bubble control process involving initial low-torque pre-tightening, constant-temperature heat preservation, and high-temperature low-pressure vacuum treatment. First, initial pre-tightening and constant-temperature heat preservation uniformly diffuse the bubbles sealed at the interface into the interior of the adhesive, preventing bonding failure caused by bubble concentration at the interface. Then, the high-temperature low-pressure environment fully dissipates the air bubbles within the adhesive layer, significantly reducing the overall gas content and porosity of the adhesive layer, improving its density and structural strength. This fundamentally solves the problems of sealing failure and lubricant leakage caused by bubble expansion within the adhesive layer under high-altitude, low-pressure conditions, preventing engine in-flight shutdown due to insufficient lubrication, and significantly improving the engine's adaptability to extreme environments and operational reliability.

[0018] This invention employs a graded assembly process of initial pre-tightening and secondary pre-tightening with rated torque after curing. This process provides stable pressure conditions for the adhesive layer during the bubble treatment stage, ensuring uniform spread of the adhesive and full diffusion and precipitation of bubbles. Furthermore, the secondary pre-tightening after the sealant has fully cured compensates for the attenuation of pre-tightening force during the curing process, ensuring the assembly accuracy and connection rigidity of the assembly. This avoids sealing failure caused by changes in the gap between the joint surfaces, thus achieving a dual guarantee of sealing performance and assembly accuracy.

[0019] The process parameters of this invention have been verified under actual working conditions and are fully compatible with the sealing and assembly requirements of wide-body, irregular and complex joint surfaces of aero-engines (especially two-stroke aero-engines). It can be directly adapted to the manual assembly and maintenance scenarios of existing aero-engines. It can not only significantly improve the sealing life of the engine housing joint surfaces, but also effectively reduce the engine maintenance costs and failure risks caused by sealing failure, and has extremely high promotion and application value.

[0020] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is an assembly diagram of the first and second assembled components; Figure 2 A schematic diagram of the complex mating surface of the first or second assembled component; Figure 3 A flowchart of the adhesive sealing method for complex mating surfaces of an aero-piston engine provided by the present invention.

[0022] Reference numerals: 1-First connected component; 2-Second connected component; 3-Fasting screw; 4-Complex mating surface. Detailed Implementation

[0023] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0026] The following combination Figures 1-3 The specific embodiments of the present invention will be described in detail below. The present invention relates to the field of aviation piston engine assembly technology, specifically to a method for applying adhesive to seal complex mating surfaces of aviation piston engines, which is particularly suitable for manual adhesive application and sealing of wide-body, discontinuous, and irregularly shaped complex mating surfaces 4 in scenarios of multi-variety, small-batch production and after-sales maintenance of two-stroke aviation piston engines.

[0027] The assembly components adapted to this invention include a first connected component 1 and a second connected component 2 to be sealed and assembled, and a fastening screw 3 for locking the two connected components; the mating sealing surfaces of the first connected component 1 and the second connected component 2 are discontinuous, irregularly shaped complex mating surfaces 4, which are adapted to the assembly method of manual gluing.

[0028] Before performing the adhesive sealing process of this invention, the pre-preparation of the components to be assembled must be completed: the surface roughness of the complex mating surface 4 of the first connected component 1 and the second connected component 2 is pre-controlled to Ra3.2. This roughness parameter setting can increase the amount of sealant stored on the complex mating surface 4 while ensuring the sealant filling performance, thereby increasing the contact area between the sealant and the connected components, solving the problem of insufficient sealant storage capacity on ultra-smooth surfaces, and providing a basic guarantee for subsequent sealing performance.

[0029] Example 1 This embodiment is a preferred embodiment of the present invention, and the specific process steps are as follows: Step S1: Preheat the first and second connected components 1 and 2 after preparation to ensure a uniform temperature field. Specifically, place them in an insulated box at 80°C. Once the set temperature is reached, continue heating for 30 minutes to ensure uniform temperature. This preheating process improves the wettability of the sealant on the complex mating surface 4, mitigating insufficient bonding between the sealant and the mating surface during cold assembly at room temperature. This provides a stable temperature basis for subsequent adhesive application and assembly processes.

[0030] Step S2: Remove the preheated first and second connected parts 1 and 2 from the insulation box. Apply sealant evenly to the complex joint surface 4 of both parts and smooth the coated surface. The specific operation is as follows: In this embodiment, SI5930 anaerobic sealant is used. The sealant is applied evenly to the sealing area of ​​the complex joint surface 4 by hand. The total time from removing the connected parts from the insulation box to completing the sealant application does not exceed 2 minutes. After application, any single-connected areas, grooves with a feature size exceeding 1mm, or holes on the sealant surface are smoothed to ensure a uniform sealant surface on the complex joint surface 4 of the two connected parts. This step strictly controls the application time to prevent a significant temperature drop in the connected parts during the application process, ensuring the sealant's fluidity and application quality. Smoothing the sealant surface eliminates defects caused by manual application, preventing poor sealant density due to grooves or holes, and ensuring the uniformity of the sealant layer after the boxes are closed.

[0031] Step S3: Align and assemble the first connected component 1 and the second connected component 2, coated with sealant, as required, ensuring precise contact between their complex mating surfaces 4. Install all fastening screws 3 and apply an initial pre-tightening torque to all screws 3 to complete the initial pre-tightening assembly. The specific operation is as follows: After assembling and positioning, install all fastening screws 3 sequentially, applying an initial pre-tightening torque to the screws 3 in a diagonal, crisscrossing order. The initial pre-tightening torque is 10% of the rated torque specified for each screw 3. This step, through low-torque initial pre-tightening, provides uniform extrusion pressure to the sealant layer, ensuring even spread of the sealant within the complex mating surface 4 without excessive extrusion due to excessive pre-tightening force. Simultaneously, it promotes the dispersion of air bubbles trapped at the interface between the sealant and the complex mating surface 4 into the interior of the sealant, increasing the effective contact area between the sealant and the connected components.

[0032] Step S4: Place the pre-tightened assembly in a constant temperature environment for static holding to allow air bubbles at the interface to fully diffuse into the sealant. Specifically, place the pre-assembled assembly in a constant temperature environment of 80℃ for 2 hours. This constant temperature holding step maintains the fluidity of the sealant, allowing air bubbles sealed at the interface during the assembly process to effectively diffuse into the sealant, preventing air bubbles from concentrating at the interface and forming leakage channels, thus laying the foundation for subsequent air bubble removal processes.

[0033] Step S5: After heat preservation and settling, place the assembly in a high-temperature, low-pressure environment to separate and release air bubbles from the sealant, improving its density. Specifically, transfer the assembly to an environment of 80°C and 133 Pa absolute pressure, and let it stand for 4 hours. This high-temperature, low-pressure treatment allows gases diffused into the sealant to be fully released, significantly reducing the overall gas content, lowering the porosity of the sealant layer, and improving its density and structural strength. This fundamentally solves the sealing leakage problem caused by air bubble expansion in the sealant layer during high-altitude, low-pressure environments.

[0034] Step S6: Place the assembly treated with high temperature and low pressure in a normal temperature and pressure environment to cool and allow the sealant to fully cure. The specific operation is as follows: Transfer the assembly to an atmospheric environment for natural cooling, controlling the ambient temperature at 20℃, and allow it to stand for at least 4 hours to ensure complete sealant curing. This step, through static cooling at normal temperature and pressure, allows the sealant to complete curing and cross-linking in a stable environment, avoiding stress concentration within the sealant layer caused by sudden temperature changes, and ensuring the structural stability and sealing performance of the cured sealant.

[0035] Step S7: After the sealant has fully cured, pre-tighten the fastening screws 3 on the assembly a second time, loading them to the rated torque according to process requirements to complete the final assembly. This step, through secondary pre-tightening with the rated torque after curing, can compensate for the pre-tightening force attenuation during the sealant curing process, ensuring the assembly accuracy of the connected parts, and further enhancing the sealing stability of the joint surface, avoiding seal failure due to insufficient pre-tightening force during engine operation.

[0036] Example 2 The adhesive sealing method for the complex mating surface 4 of the aero-piston engine described in this embodiment is completely identical to that in Embodiment 1 in terms of overall process steps. The only difference lies in the adjustment of process parameters and material selection, both of which are optional within the scope covered by the claims of this invention. 1. In step S1, the heating temperature of the heat preservation box is set to 100℃, and the heating and heat preservation time is 30 minutes; 2. In step S2, Loctite 577 anaerobic sealant is selected as the sealant; 3. In step S6, the ambient temperature for room temperature cooling is controlled within the range of 15℃~25℃, and the standing time is not less than 4 hours.

[0037] The process method described in this embodiment can also effectively separate the gas mixed in by manual adhesive application, ensure the amount of sealant and the bonding strength of the complex joint surface 4, improve the sealing reliability, and adapt to the sealing assembly requirements of the complex joint surface 4 of aero-piston engines under different working conditions.

[0038] 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 preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for sealing complex mating surfaces of an aero-piston engine using adhesive, the method being used for sealing and assembling complex mating surfaces between a first connected component and a second connected component, wherein the first connected component and the second connected component are locked together by fastening screws, characterized in that... Includes the following steps: Step S1: Preheat the first and second connected parts to make the overall temperature field of the two connected parts uniform. Step S2: Apply sealant to the complex joint surfaces of the first and second connected parts after preheating, and smooth the coated surface. Step S3: Align the first and second connected parts coated with sealant to ensure precise contact of their complex mating surfaces. Install all fastening screws for securing the two connected parts and apply an initial pre-tightening torque to all fastening screws. The initial pre-tightening torque is 5% to 15% of the rated pre-tightening torque of the fastening screws. This completes the initial pre-tightening assembly. Step S4: Place the pre-tightened assembly in a constant temperature environment of 75℃~85℃ and keep it still to allow the air bubbles sealed in the sealant interface on the complex joint surface to diffuse into the interior of the sealant. Step S5: Place the assembled body after heat preservation in a high temperature and low pressure environment of 75℃~85℃ and absolute pressure of 100Pa~200Pa to release the air bubbles inside the sealant and improve the density of the sealant. Step S6: Place the assembly that has undergone high temperature and low pressure treatment in a normal temperature and pressure environment to cool and stand, allowing the sealant to fully cure and solidify. Step S7: Apply the rated preload torque to the fastening screws on the assembly after the sealant has cured to complete the secondary preload assembly.

2. The method according to claim 1, characterized in that, In step S1, the preheating process specifically involves placing the first and second connected components in an insulated box for heating. The heating temperature is controlled at 80°C to 100°C, and the heating time is not less than 30 minutes, until the temperature field of the two connected components is uniform.

3. The method according to claim 1, characterized in that, Before step S1, the surface roughness of the complex joint surface between the first connected component and the second connected component is controlled at Ra3.2 to increase the amount of sealant stored in the complex joint surface and the contact area between the sealant and the complex joint surface.

4. The method according to claim 1, characterized in that, In step S2, the applied sealant is an anaerobic sealant, specifically SI5930 anaerobic sealant or Loctite 577 anaerobic sealant.

5. The method according to claim 1, characterized in that, In step S2, the surface smoothing treatment specifically involves scraping and smoothing out single-connected areas, grooves or holes with a feature size exceeding 1 mm that exist on the adhesive surface after application.

6. The method according to claim 1, characterized in that, In step S3, the initial preload torque applied to the fastening screw is 10% of the rated preload torque of the fastening screw.

7. The method according to claim 1, characterized in that, In step S4, the temperature of the constant temperature environment is controlled at 80℃, and the temperature is kept at a constant temperature for no less than 2 hours.

8. The method according to claim 1, characterized in that, In step S5, the temperature of the high-temperature and low-pressure environment is controlled at 80°C, the absolute pressure is controlled at 133Pa, and the standing time is not less than 4 hours.

9. The method according to claim 1, characterized in that, In step S6, the temperature of the ambient temperature and pressure environment is controlled at 15℃~25℃, and the cooling and standing time is not less than 4 hours.

10. The method according to claim 1, characterized in that, In step S2, after the first and second connected components are taken out of the insulation box, the time for applying sealant to the complex joint surface shall not exceed 2 minutes.

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