Cabin thermal protection structure forming method

Abstract

The invention belongs to the technical field of composite material forming, and relates to a cabin thermal protection structure forming method which comprises the following steps: designing a needled felt; the needled felt is prepared; loading the needled felt into a mold and sealing; hybrid phenolic resin is injected into the mold; heating the mold to cure the hybrid phenolic resin; obtaining, heating and drying the heat-proof layer in the mold; the bonding face of the heat-proof layer and the structural part is coated with a primer; coating a silicon-based adhesive on the bonding surface; bonding and curing the heat-proof layer and the structural member; and processing the bonding allowance. According to the cabin thermal protection structure forming method provided by the invention, the heat-proof sleeve and the force-bearing structure are separately prepared, and then the heat-proof sleeve and the force-bearing structure are connected into the integral part in a sleeving manner, so that the heat-proof sleeve and the structural part can be produced in parallel, the production efficiency of products is greatly improved, and the production period is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material molding, and in particular to a method for molding a cabin thermal protection structure. Background Art

[0002] When an aircraft flies over a large area in the atmosphere, its working environment is a typical high-temperature, long-flight environment. Ordinary phenolic ablative resin-based composite materials have too much ablation in this working environment, and have high thermal conductivity and fast heat transfer, so they cannot meet the aircraft's heat protection and insulation requirements.

[0003] At the same time, C-scan, acoustic resonance and other detection methods commonly used for internal quality inspection of composite materials are difficult to detect the bonding quality between the thermal protection layer and the structural layer due to the structural shape and porous characteristics of the thermal protection material. Summary of the invention

[0004] In view of this, the present invention provides a method for forming a cabin thermal protection structure.

[0005] Specifically, the present invention is achieved through the following technical solutions:

[0006] According to a first aspect of the present invention, a method for forming a cabin thermal protection structure is provided, the method comprising the steps of:

[0007] Design needle felt;

[0008] preparing the needle felt;

[0009] The needle felt is placed into a mold and sealed;

[0010] injecting a hybrid phenolic resin into the mold;

[0011] heating the mold to cure the hybrid phenolic resin;

[0012] Obtaining and heating and drying the heat-proof layer in the mold;

[0013] Applying a primer on the bonding surface of the heat-proof layer and the structural member;

[0014] Applying a silicone-based adhesive to the bonding surface;

[0015] Bonding and curing the heat protection layer and the structural member;

[0016] Processing bonding allowance.

[0017] Optionally, the designing of the needle felt comprises the steps of:

[0018] Get technical parameters;

[0019] The structural parameters of the needle felt are designed according to the technical parameters.

[0020] Optionally, the obtaining of technical parameters comprises the steps of:

[0021] Obtaining the bulk density of the composite material;

[0022] Get tensile strength parameters;

[0023] Obtain high temperature ablation parameters.

[0024] Optionally, designing the structural parameters of the needle felt according to the technical parameters comprises the steps of:

[0025] Designing comprehensive density parameters of the needle felt;

[0026] Designing the fabric layer parameters of the inner reinforcement fabric of the needle felt;

[0027] Designing the fabric structure of the inner reinforcement fabric of the needle felt;

[0028] Designing the tread density of the needle-punched net for reinforcing fabric inside the needle-punched felt;

[0029] The number of web layers of the inner reinforcing fabric of the needle felt is designed.

[0030] Optionally, the injecting of the hybrid phenolic resin into the mold comprises the steps of:

[0031] Maintaining the pressure of the mold at 0.05MPa-0.3MPa;

[0032] A hybrid phenolic resin is injected into the mold.

[0033] Optionally, the heating temperature of heating the mold to cure the hybrid phenolic resin is 80°C-130°C.

[0034] Optionally, the heating time of heating the mold to cure the hybrid phenolic resin is 16 hours to 40 hours.

[0035] Optionally, the heating temperature for obtaining and heating and drying the heat-proof layer in the mold is 40°C-100°C.

[0036] Optionally, the heating time for obtaining and heating and drying the heat-proof layer in the mold is 48-72 hours.

[0037] Optionally, the step of applying a primer on the bonding surface of the heat protection layer and the structural member comprises the following steps:

[0038] Clean the inner bonding surface of the heat-proof layer and the outer bonding surface of the load-bearing structural member and let them dry;

[0039] The primer is applied to the bonding surface of the heat-proof layer and the structural member respectively and left to cool for a preset time.

[0040] The technical solution provided by the present invention brings at least the following beneficial effects:

[0041] The present application provides a method for forming a cabin thermal protection structure by separately preparing a heat protection sleeve and a load-bearing structure, and then sleeved them into an integral part. This method can enable the heat protection sleeve and the structural parts to be produced in parallel, greatly improving the production efficiency of the products and shortening the production cycle. Flexible silicone-based glue is used for the sleeve, and the amount of silicone-based glue and the brushing shape are controlled during the glue liquid coating process. The bonding is reliable and can be deformed to coordinate the effect of thermal deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0044] Figure 1 A schematic diagram of a serrated scraper in a cabin thermal protection structure forming method provided in this application;

[0045] Figure 2 A schematic diagram of the first scraping of a strip-shaped adhesive in a cabin thermal protection structure molding method provided in the present application;

[0046] Figure 3 A schematic diagram of a dot matrix glue set after secondary scraping in a cabin thermal protection structure molding method provided in this application;

[0047] Figure 4 A schematic diagram of the cross-section of the cabin structure after assembly in a cabin thermal protection structure molding method provided in the present application. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Reference Figure 1-4As shown, the present application provides a method for forming a cabin thermal protection structure, the method comprising the steps of:

[0050] S1: Design needle felt;

[0051] Exemplarily, the design of needle felt comprises the steps of:

[0052] Get technical parameters;

[0053] The structural parameters of the needle felt are designed according to the technical parameters.

[0054] In the embodiment of the present application, the structural parameters of the needle felt are designed according to the technical parameters required by the material design input. If necessary, the surface layer is designed as a dense layer with many layers of reinforced fabric and high density, and the inner layer is designed as a lightweight layer with few layers of fabric and low density. The technical requirement document of the needle felt is formed according to the design results of the needle felt. The advantages are: 1. The performance of the needle felt can be improved: the surface layer is designed as a dense layer with many layers of reinforced fabric and high density, which can enhance the wear resistance, tear strength and corrosion resistance of the needle felt, thereby increasing its service life; the inner layer is designed as a lightweight layer with few layers of fabric and low density, which helps to reduce the overall weight of the needle felt while maintaining good air permeability and filtration efficiency. 2. The material utilization rate can be optimized: by accurately designing the structural parameters of the needle felt, the material can be reasonably allocated according to actual needs to avoid material waste; for different application environments, the number of layers and density of the needle felt can be flexibly adjusted to achieve the best material utilization rate and performance balance. 3. Meet diverse needs: This design method can customize needle felt with specific properties according to different application requirements, such as high temperature, high pressure, strong corrosion and other environments; by adjusting the structural parameters of the needle felt, it can meet the special requirements of different industries for the performance of needle felt. 4. Simplify the production process: With clear technical requirements documents, each step in the production process can be carried out in accordance with the document requirements, thereby simplifying the production process and improving production efficiency; technical requirements documents can also be used as a basis for quality control and inspection to ensure that the produced needle felt meets the design requirements.

[0055] Exemplarily, the obtaining of technical parameters comprises the steps of:

[0056] Obtaining the bulk density of the composite material;

[0057] Get tensile strength parameters;

[0058] Obtain high temperature ablation parameters.

[0059] In the embodiments of the present application, the technical parameters include the volume density, tensile strength, high temperature ablation, etc. of the composite material.

[0060] Exemplarily, designing the structural parameters of the needle felt according to the technical parameters comprises the steps of:

[0061] Designing comprehensive density parameters of the needle felt;

[0062] Designing the fabric layer parameters of the inner reinforcement fabric of the needle felt;

[0063] Designing the fabric structure of the inner reinforcement fabric of the needle felt;

[0064] Designing the tread density of the needle-punched net for reinforcing fabric inside the needle-punched felt;

[0065] The number of web layers of the inner reinforcing fabric of the needle felt is designed.

[0066] In the embodiments of the present application, the structural parameters of the needle felt include the comprehensive density of the needle felt, the structure of the reinforcing fabric inside the needle felt (generally a two-dimensional plain fabric or twill fabric) such as the number of fabric layers, the fabric structure (such as surface density, thickness, plain or twill weave), and the surface density and number of mesh layers of the needle felt.

[0067] S2: preparing the needle felt;

[0068] In the embodiment of the present application, according to the cabin structure shape, a prefabricated needle punching mold (generally a cylindrical or conical shape with the same shape as the cabin, and can be made of wood or plastic) is prepared, and the mesh tire and reinforcing fabric are laid on the needle punching mold according to the needle felt structure design, and are laid and needle punched layer by layer until the thickness and number of layers meet the design requirements. A margin of no less than 20 mm is reserved at the front and rear ends of the cabin needle felt. It is required to inspect the needle felt with an X-ray detector, DR detector or metal detector to prevent the inclusion of foreign matter such as metal inside. The prepared cabin needle felt interconnection mold is transferred to the RTM (resin transfer molding) mold installation site. The benefits are: 1. Improving the adaptability of the cabin needle felt: By prefabricating the needle punching mold according to the cabin structure shape, it can be ensured that the shape of the needle punched felt is exactly the same as the cabin, thereby improving the adaptability and installation efficiency of the needle punched felt on the cabin; the reserved front and rear end margins (not less than 20mm) will help to make necessary adjustments during subsequent processing and installation to ensure that the needle punched felt can fit tightly to the cabin surface. 2. Optimizing the preparation process of needle punched felt: Laying the mesh tire and reinforcing fabric layer by layer on the needle punching mold and performing needle punching can ensure that the number of layers and thickness of the needle punched felt meet the design requirements, while ensuring that the internal structure of the needle punched felt is uniform and dense; this preparation method avoids the errors and unevenness that may occur in traditional manual laying, and improves the quality and consistency of the needle punched felt. 3. Ensure the quality of needle felt: Use X-ray detectors, DR detectors or metal detectors and other detection equipment to check needle felt, which can effectively prevent the inclusion of metal and other foreign matter inside, and ensure the purity and safety of needle felt; these detection equipment have high precision and high sensitivity, and can accurately detect tiny foreign matter inside the needle felt, so as to ensure that the quality of needle felt meets relevant standards and requirements. 4. Improve production efficiency: Prefabricated needle felt molds and layer-by-layer laying and needle punching preparation methods can realize the automated or semi-automated production of needle felt, thereby greatly improving production efficiency; directly transferring the prepared cabin needle felt interconnection mold to the RTM mold installation site can reduce intermediate links and transportation time, and further speed up production progress. 5. Reduce costs: The production cost of needle felt can be reduced by optimizing the preparation process and improving production efficiency; prefabricated needle felt molds can be reused, reducing mold costs; the use of detection equipment can reduce rework and scrapping caused by quality problems, further reducing production costs.

[0069] S3: loading the needle felt into a mold and sealing it;

[0070] In an embodiment of the present application, a layer of pressure-sensitive tape is affixed to the working surface of the metal RTM mold; the prepared needle felt is removed from the needle mold and assembled together with the male mold of the RTM mold, and then the mold female mold is assembled to pre-press the needle felt through the female mold. The pre-pressing time is maintained for about 15 minutes to 60 minutes, and then the mold is opened to check the apparent quality of the needle felt, and to deal with problems such as wrinkles that appear; then the pre-pressing inspection is performed again until there are no obvious wrinkles or other defects on the surface. Then the mold is loaded and sealed with a sealing rope. The advantages are: 1. Improving the sealing of the mold: A layer of pressure-sensitive tape is affixed to the working surface of the metal RTM mold, which can effectively prevent the resin from leaking from the mold gap during the injection process, thereby improving the sealing of the mold; the pressure-sensitive tape has good adhesion and releasability, is easy to stick on and remove from the mold, and will not cause damage to the mold surface. 2. Optimize the matching between needle felt and mold: Assemble the prepared needle felt with the convex mold of RTM mold and pre-press it through the concave mold, so that the needle felt can better fit the mold surface and avoid dislocation or movement during the resin injection process; the pre-pressing process can also make the fibers inside the needle felt more closely arranged, improving the strength and stability of the needle felt. 3. Ensure the apparent quality of needle felt: Through multiple pre-pressing and inspection, the wrinkles, bubbles and other defects on the surface of the needle felt can be found in time and treated; this can ensure that the surface of the final composite product is flat and smooth to meet the quality requirements. 4. Improve production efficiency: The pre-pressing and sealing steps can ensure that a certain pressure and temperature are maintained inside the mold during the resin injection process, thereby accelerating the curing of the resin and the formation of the composite material; this helps to shorten the production cycle and improve production efficiency. 5. Reduce production costs: By optimizing the preparation and assembly process, rework and scrap caused by quality problems such as mold leakage and needle felt dislocation can be reduced; this helps to reduce production costs and improve the economic benefits of enterprises. 6. Enhance the performance of composite products: The use of pressure-sensitive tape and the good match between needle felt and mold can ensure that the resin is evenly distributed inside the mold and fully infiltrates the needle felt; this helps to enhance the mechanical properties, heat resistance and chemical corrosion resistance of composite products.

[0071] S4: injecting a hybrid phenolic resin into the mold;

[0072] In the embodiment of the present application, the hybrid phenolic resin is injected at a pressure of 0.05MPa-0.3MPa, and the mold is kept sealed. The benefits are: 1. Ensure that the resin is fully infiltrated: Injecting the hybrid phenolic resin under appropriate pressure can ensure that the resin can fully infiltrate the fibers in the needle felt and form a tight bond. This helps to improve the strength and stability of the composite product. 2. Improve the performance of the composite material: The hybrid phenolic resin has excellent heat resistance, flame retardancy, low smoke emission and low toxicity. Injecting the resin under appropriate pressure can give full play to these properties, thereby preparing high-performance composite products. 3. Optimize the curing process: Keeping the mold sealed and injecting the resin under appropriate pressure helps to control the temperature and pressure conditions during the curing process. This can ensure that the resin forms a uniform network structure during the curing process and improve the overall performance of the composite material. 4. Reduce bubbles and defects: Appropriate pressure and sealing conditions help to eliminate bubbles and impurities in the resin and reduce defects in composite products. This helps to improve the quality and reliability of the product. 5. Improve production efficiency: This preparation method can shorten the production cycle and improve production efficiency. Because appropriate pressure and sealing conditions can accelerate the curing of the resin and the formation of the composite material. 6. Reduce production costs: By optimizing the preparation process, rework and scrap caused by quality problems can be reduced, thereby reducing production costs. At the same time, using hybrid phenolic resin as the matrix material can also reduce material costs to a certain extent.

[0073] S5: heating the mold to cure the hybrid phenolic resin;

[0074] In the embodiment of the present application, a buffer tank that is connected to the mold cavity is connected to the glue outlet at the top of the mold, and the volume of the buffer tank is about 2%-15% of the volume of the mold cavity. While maintaining a sealed state, use an oven or the like to heat to cure the resin; the heating temperature is 80°C-130°C, and the heating time is 16h-40h. The benefits are: 1. Pressure stability and bubble reduction: The setting of the buffer tank can effectively stabilize the pressure in the mold cavity. During the resin curing process, the pressure in the cavity may change with the flow and curing reaction of the resin. The buffer tank can absorb and release these pressure changes, thereby maintaining the relative stability of the pressure in the cavity. Stable pressure helps to reduce the generation of bubbles in the resin. Bubbles are common defects in composite products, which will reduce the strength and durability of the products. Through the buffering effect of the buffer tank, the formation of bubbles can be significantly reduced and the quality of the product can be improved. 2. Resin flow control: The buffer tank can also serve as a "buffer" for resin flow to help control the flow speed and direction of the resin in the mold cavity. This helps to ensure that the resin can evenly fill the entire mold cavity, avoiding local glue shortages or resin accumulation. Uniform resin distribution is crucial to the performance of composite materials. It can ensure that the product has consistent mechanical properties and durability in all directions. 3. Optimization of heating and curing effect: Using heating equipment such as an oven to cure the resin while maintaining a sealed state can ensure that the resin is not affected by the external environment during the curing process. The sealed state helps prevent impurities such as oxygen and moisture from entering the mold cavity, thereby affecting the curing reaction of the resin. Accurate control of heating temperature and time is crucial to the curing effect of the resin. In this embodiment, the heating temperature is 80℃-130℃, and the heating time is 16h-40h. The selection of these parameters can be adjusted according to the specific resin type and product requirements to ensure that the resin can be fully cured and form a stable network structure. 4. Improved product performance: Through the above measures, composite products with excellent performance can be prepared. These products have the characteristics of high strength, high toughness, good heat resistance, etc., and can meet the use requirements in various harsh environments. In addition, since the resin is fully infiltrated and cured during the curing process, the internal structure of the product is more compact and uniform, thereby improving its durability and service life. 5. Production efficiency and cost control: Although the setting of the buffer tank and the heating and curing process require a certain amount of time and cost investment, in the long run, these measures can significantly improve production efficiency and reduce production costs. By optimizing the resin flow control and curing process, rework and scrap caused by product defects can be reduced. This helps to reduce production costs and improve the economic benefits of the enterprise.

[0075] S6: obtaining and heating and drying the heat-proof layer in the mold;

[0076] In the embodiment of the present application, after the curing is completed, the mold concave mold is removed and left to cool at room temperature for 8-50 hours; then the convex mold is placed in an oven or the like together with the product in an open state for heating, and heated at 40℃-100℃ for 48-72 hours to dry and shape the heat-proof layer product. After drying, the heat-proof layer product is demoulded and separated from the convex mold. The heat-proof layer is inspected by an X-ray detector or a DR detector to detect abnormal defects such as metal inclusions and uneven resin impregnation inside the composite material. The advantages of doing this are: 1. Benefits of cooling at room temperature: After the curing is completed, the mold concave mold is removed and left to cool at room temperature for a period of time (8-50 hours), which helps the product to gradually cool and release internal stress. This can reduce deformation or cracks caused by rapid cooling and improve the dimensional stability and mechanical properties of the product. 2. Advantages of heating and drying molding: Put the convex mold together with the product in an oven or other heating equipment in an open state, and heat it at 40℃-100℃ for 48-72 hours, so that the heat-proof layer product can be further dried and formed. This process helps to remove residual moisture or volatile substances in the product and improve the density and heat resistance of the product. At the same time, heating can also promote further cross-linking reactions between resin and fiber, enhance the internal bonding force of the composite material, and thus improve the overall performance of the product. 3. Convenience of demoulding and separation: After drying, the heat protection layer product is demoulded and separated from the punch. Since sufficient heating and drying treatment has been carried out before, the adhesion between the product and the mold will be greatly reduced, making the demoulding process smoother and more efficient. 4. Accuracy of detecting internal defects: Using an X-ray detector or a DR detector to inspect the heat protection layer can accurately detect abnormal defects such as metal and other foreign matter inclusions in the product and uneven resin impregnation in the composite material. If these defects are not discovered and handled in time, they may seriously affect the performance and safety of the product. Through this non-destructive detection method, the internal quality of the product can be comprehensively and accurately evaluated without destroying its appearance and structure. 5. Improve the reliability of product quality: The implementation of the above series of treatment measures can significantly improve the quality and reliability of the heat protection layer products. Through strict testing and quality control measures, it can be ensured that each batch of products meets the design requirements and quality standards.

[0077] S7: Applying a primer on the bonding surface of the heat protection layer and the structural member;

[0078] In the embodiment of the present application, the bonding surface of the inner profile of the heat-proof layer and the bonding surface of the outer profile of the load-bearing structural member are cleaned and dried; the primer is brushed on the bonding surface of the heat-proof layer and the structural member respectively, and left to cool for 30-60 minutes. The advantages of this are: 1. Improving the bonding strength: Cleaning the bonding surface and drying it can remove impurities such as oil and dust on the surface, and provide a clean and flat base surface for the application of the primer. This helps the primer to better penetrate and adhere to the bonding surface, thereby improving the bonding force between the primer and the bonding surface. The primer itself has the effect of enhancing the surface adhesion, can fill the tiny defects on the surface of the substrate, and form a uniform coating. This coating can increase the contact area and bonding force between the adhesive and the substrate, thereby improving the strength of the entire bonding system. 2. Optimizing the bonding effect: After the primer is brushed on the bonding surface, it can adjust the surface energy of the bonding surface to make it more suitable for the infiltration and diffusion of the adhesive. This helps the adhesive to form a more uniform and dense bonding layer on the bonding surface, thereby improving the bonding effect. The primer can also improve the wettability of the bonding surface, making it easier for the adhesive to penetrate into the tiny pores of the substrate to form a stronger bond. 3. Improve production efficiency: The process of cleaning and drying the bonding surface is relatively simple and quick, and does not take up too much production time. At the same time, the application and cooling process of the primer can also be completed in a shorter time, thereby improving the efficiency of the entire production process. 4. Reduce production costs: By optimizing the bonding process and using primers, rework and scrap caused by poor bonding can be reduced. This helps to reduce production costs and improve the economic benefits of the enterprise. 5. Enhance product reliability and durability: Good bonding effect can ensure a close connection between the heat protection layer and the structural parts, thereby improving the overall strength and stability of the product. This helps to enhance the reliability and durability of the product, enabling it to work normally in a more severe environment.

[0079] S8: Applying a silicone-based adhesive to the bonding surface;

[0080] In the embodiment of the present application, a silicone set adhesive (adhesive model JG-1C or S-1) is prepared according to the ratio, and then the set adhesive is brushed on the outer bonding surface of the load-bearing structural member and the inner bonding surface of the heat-proof layer. The brushing method is: use a serrated scraper (the sawtooth width of the serrated scraper should be greater than the width of the scraping strip), first brush along the axial angle of about 45 degrees, and brush the silicone-based adhesive into strips along the corresponding angle; then use a serrated scraper without adhesive to scrape once in the prefabricated vertical direction to make the adhesive liquid form a square lattice shape.

[0081] S9: bonding and curing the heat protection layer and the structural member;

[0082] In the embodiment of the present application, the load-bearing shell and the heat-proof layer are pressed together according to the positioning relationship between the heat-proof layer and the load-bearing structural member, and cured at room temperature for no less than 7 days.

[0083] S10: Processing bonding allowance.

[0084] In the embodiment of the present application, the excess of the front and rear end surfaces of the cabin section is removed by mechanical processing. The internal quality of the bonding surface of a certain angle of the cabin section is detected by an X-ray detector, a DR detector, or an industrial CT detector, and the grayscale difference of the bonding surface is used to evaluate the bonding quality of the bonding surface; then rotate 15-60° or move longitudinally to detect another cross section until the detection of one rotation is completed. The overall bonding quality of the cabin section is evaluated through the detection results of multiple angles of the entire cabin section.

[0085] In summary, the cabin thermal protection structure forming method provided in the embodiment of the present application includes the following advantages:

[0086] 1. Significant improvement in production efficiency: By preparing the heat shield and the load-bearing structure separately and then connecting them into an integral part, the present invention realizes the parallel production of the heat shield and the structural parts. This parallel production mode significantly improves production efficiency because the two parts can be prepared at the same time without waiting for one part to be completed before starting the production of the other part. This production method effectively shortens the production cycle and speeds up product delivery.

[0087] 2. Reduction of production costs: The improvement of production efficiency directly leads to the reduction of production costs. Due to the shortened production cycle, enterprises can reduce work-in-progress inventory and production costs, while improving equipment utilization and personnel work efficiency. In addition, the parallel production model also helps to reduce waste and rework in the production process, further reducing production costs.

[0088] 3. Improvement of product quality: The method of the present invention adopts strict process control and quality control measures during the preparation process. For example, when preparing needle felt, the uniformity and stability of the needle felt can be ensured by accurately controlling the needle density and fiber arrangement direction. When injecting hybrid phenolic resin, the sufficient infiltration and curing of the resin can be ensured by accurately controlling the injection pressure and temperature. These measures jointly improve the quality and reliability of the product.

[0089] 4. Flexibility and scalability: The molding method of the present invention has high flexibility and scalability. By adjusting the design parameters of the needle felt, the type of resin and the curing conditions, etc., thermal protection structures with different performances and uses can be prepared. In addition, the method can also meet the needs of thermal protection structures of cabins of different sizes and shapes, providing the possibility for customization and diversification of products.

[0090] 5. Environmental protection and sustainability: As a high-performance composite matrix material, hybrid phenolic resin has excellent heat resistance, flame resistance and low toxicity. The thermal protection structure prepared using this material not only has excellent performance, but also meets the requirements of environmental protection and sustainability. In addition, the method of the present invention reduces the generation of waste and energy consumption during the preparation process, which helps to reduce the impact on the environment.

[0091] 6. Simplify the production process: The traditional method of preparing a thermal protection structure may require multiple complex steps and processes. The method of the present invention simplifies the production process by preparing the heat protection sleeve and the structural part separately and then connecting them into an integral part. This simplification not only improves production efficiency, but also helps reduce errors and uncertainties in the production process.

[0092] 7. Improve product adaptability: Since the heat shield and structural parts are prepared separately, they can be customized and optimized according to different application requirements. This flexibility enables the product to better adapt to different working environments and conditions, improving the adaptability and market competitiveness of the product.

[0093] A method for forming a cabin thermal protection structure provided in an embodiment of the present application prepares a heat protection sleeve and a load-bearing structure separately and then connects them into an integral part. This method can enable the heat protection sleeve and the structural parts to be produced in parallel, greatly improving the production efficiency of the products and shortening the production cycle. Flexible silicone-based glue is used for the sleeve, and the amount of silicone-based glue and the brushing shape are controlled during the glue application process. The bonding is reliable and can be deformed to coordinate the effect of thermal deformation.

[0094] It should be noted that, in the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0095] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0096] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0097] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0098] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for forming a cabin thermal protection structure, characterized in that: The method comprises the steps of: Design needle felt; preparing the needle felt; The needle felt is placed into a mold and sealed; injecting a hybrid phenolic resin into the mold; heating the mold to cure the hybrid phenolic resin; Acquiring and heating and drying the heat-proof layer in the mold; Applying a primer on the bonding surface of the heat-proof layer and the structural member; Applying a silicone-based adhesive to the bonding surface; Bonding and curing the heat protection layer and the structural member; Processing bonding allowance.

2. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The design of needle felt comprises the steps of: Get technical parameters; The structural parameters of the needle felt are designed according to the technical parameters.

3. The method for forming a cabin thermal protection structure according to claim 2, characterized in that: The obtaining of technical parameters comprises the steps of: Obtaining the bulk density of the composite material; Get tensile strength parameters; Obtain high temperature ablation parameters.

4. The method for forming a cabin thermal protection structure according to claim 2, characterized in that: The designing of the structural parameters of the needle felt according to the technical parameters comprises the following steps: Designing comprehensive density parameters of the needle felt; Designing the fabric layer parameters of the inner reinforcement fabric of the needle felt; Designing the fabric structure of the inner reinforcement fabric of the needle felt; Designing the tread density of the needle-punched net for reinforcing fabric inside the needle-punched felt; The number of web layers of the inner reinforcing fabric of the needle felt is designed.

5. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The step of injecting the hybrid phenolic resin into the mold comprises the following steps: Maintaining the pressure of the mold at 0.05MPa-0.3MPa; A hybrid phenolic resin is injected into the mold.

6. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The heating temperature for heating the mold to cure the hybrid phenolic resin is 80° C.-130° C.

7. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The heating time for heating the mold to cure the hybrid phenolic resin is 16 hours to 40 hours.

8. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The heating temperature for obtaining and heating and drying the heat-proof layer in the mold is 40°C-100°C.

9. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The heating time for obtaining and heating and drying the heat-proof layer in the mold is 48-72 hours.

10. The method for forming a cabin thermal protection structure according to claim 1, characterized in that: The step of applying a primer on the bonding surface of the heat-proof layer and the structural member comprises the following steps: Clean the inner bonding surface of the heat-proof layer and the outer bonding surface of the load-bearing structural member and let them dry; The primer is applied to the bonding surface of the heat-proof layer and the structural member respectively and left to cool for a preset time.

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