A structural member and a forming method

Abstract

This application provides a structural component and a molding method, relating to the field of composite material molding technology. The method includes providing a mold comprising a first plate, a second plate, and a third plate connected sequentially, with the first and third plates respectively having a rounded transition at their connections to the second plate. Prepreg is laid on the surfaces of the first, second, and third plates of the mold. A skin is laid on top of the prepreg, comprising a bottom skin and a top skin stacked sequentially, the bottom skin covering the rounded area of ​​the prepreg, and the top skin covering the prepreg. The prepreg is then hot-pressed to cure, forming the structural component. The bottom skin prevents the prepreg in the rounded area from sliding towards both ends during hot-pressing curing, while the top skin prevents the prepreg in the flat area from sliding towards the rounded area during hot-pressing curing. Through their synergistic effect, the flow of the prepreg is jointly controlled during hot-pressing curing, greatly alleviating the problem of prepreg accumulation in the rounded area and improving the flatness of the structural component.

Description

Technical Field

[0001] This application relates to the field of composite material molding technology, and more specifically, to a structural component and a molding method. Background Technology

[0002] Autoclave molding is a core manufacturing method that involves encapsulating a mold covered with prepreg in a vacuum bag and then placing it in a high-temperature, high-pressure vessel. The combined effect of gas pressure and vacuum environment allows the resin to cure and crosslink under precise temperature control, resulting in composite material structural parts with high fiber volume fraction, low porosity, excellent mechanical properties, and precise dimensions.

[0003] When using autoclave molding to prepare structural parts with small-angle (R<1.5mm) arc-shaped areas, prepreg accumulation is prone to occur in the arc-shaped areas during the autoclave molding process, resulting in wrinkles in the molded structural parts. Summary of the Invention

[0004] The purpose of this application is to address the shortcomings of the prior art by providing a structural component and a molding method, in order to solve the problem that when using autoclave molding to prepare structural components with arc-shaped areas of small angle (R < 1.5 mm), prepreg accumulation in the arc-shaped area is prone to occur during the autoclave molding process, resulting in wrinkles in the molded structural component.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: One aspect of this application provides a method for forming a structural component, comprising: providing a mold, the mold including a first plate, a second plate and a third plate connected in sequence, the first plate and the third plate respectively having a rounded transition at the connection points with the second plate; laying prepreg on the surfaces of the first plate, the second plate and the third plate of the mold; laying a skin on top of the prepreg, the skin including a bottom skin and a top skin stacked in sequence, the bottom skin covering the rounded area of ​​the prepreg, and the top skin covering the prepreg; and hot-pressing the prepreg to cure it to form a structural component.

[0006] Optionally, the skin also includes an outer skin, which is laid on top of the top skin and covers the arcuate area of ​​the prepreg.

[0007] Optionally, the prepreg is made of unidirectional carbon fiber and epoxy resin or unidirectional glass fiber and epoxy resin, the bottom skin is made of the same material as the prepreg, and the top skin and outer skin are made of silicone rubber.

[0008] Optionally, a skin is laid on top of the prepreg, the skin comprising a bottom skin and a top skin stacked sequentially, the bottom skin covering the arcuate area of ​​the prepreg, and before the top skin covers the prepreg, the method further includes: squeezing the prepreg along the fiber extension direction of the prepreg to remove air bubbles between the prepreg and the mold.

[0009] Optionally, after extruding the prepreg along the fiber extension direction to remove air bubbles between the prepreg and the mold, the method further includes laying a first semi-permeable membrane over the prepreg, the first semi-permeable membrane being used to allow gas inside the prepreg to pass through and to prevent the prepreg from flowing.

[0010] Optionally, a skin is laid on top of the prepreg, the skin comprising a bottom skin and a top skin stacked in sequence, the bottom skin covering the arcuate area of ​​the prepreg, and after the top skin covers the prepreg, the method further includes: opening through holes in the skin, the through holes corresponding to the arcuate area of ​​the prepreg. Optionally, there are multiple through holes, which are arranged at intervals along the arc area. The distance between two adjacent through holes is L, 100mm≤L≤500mm, and the diameter of the through holes is Φ, 2mm≤Φ≤3mm.

[0011] Optionally, before the hot-pressed prepreg is cured to form a structural component, the method further includes: sequentially stacking a second semi-permeable membrane, a breathable felt, and a vacuum bag on the skin; sealing the mold with the vacuum bag; and venting the vacuum bag to -0.08 MPa and holding the pressure for 30-60 minutes.

[0012] Optionally, the process of hot-pressing prepreg to cure and form a structural component includes: placing a mold with a skin onto an autoclave; controlling the temperature of the autoclave to first increase from room temperature to 90°C at a rate of 1°C / min and holding for 40 min; then controlling the pressure of the autoclave to increase from normal atmospheric pressure to 0.3 MPa at a rate of 0.1 MPa / 10 min and increasing its temperature to 100°C at a rate of 1°C / min and holding for 90 min; then controlling the pressure of the autoclave to increase to 0.6 MPa at a rate of 0.1 MPa / 10 min and increasing its temperature to 140°C at a rate of 1°C / min and holding for 100 min; then cooling the temperature of the autoclave to 60°C at a rate of 0.5°C / min and maintaining the pressure of the autoclave at 0.6 MPa; and finally controlling the autoclave to cool naturally to room temperature and then depressurizing.

[0013] In another aspect of this application, a structural component is provided, comprising a structural component prepared using the above-described structural component forming method. The structural component includes a fourth plate, a fifth plate, and a sixth plate connected in sequence, with the fourth plate and the sixth plate respectively forming a rounded transition at their connection points with the fifth plate.

[0014] The beneficial effects of this application include: This application provides a method for forming a structural component, comprising: providing a mold, the mold including a first plate, a second plate, and a third plate connected in sequence, with the first and third plates respectively having a rounded transition at their connection points with the second plate; laying prepreg on the surfaces of the first, second, and third plates of the mold; laying a skin on top of the prepreg, the skin including a bottom skin and a top skin stacked in sequence, the bottom skin covering the rounded area of ​​the prepreg, and the top skin covering the prepreg; and hot-pressing the prepreg to cure it and form a structural component. By setting the bottom skin and the top skin, the bottom skin only covers the prepreg in the rounded area, playing a local anchoring role and preventing the prepreg in the rounded area from sliding and accumulating at both ends during hot-pressing and curing. The top skin covers the entire area of ​​the prepreg, providing overall constraint and preventing the prepreg in the flat area from sliding into the rounded area during hot-pressing and curing, and evenly distributing pressure. Through the synergistic effect of the bottom skin and the top skin, the flow of the prepreg is jointly controlled during hot-pressing and curing, greatly alleviating the problem of prepreg accumulation in the rounded area and improving the flatness of the structural component. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is one of the flowcharts for a structural component forming method provided in an embodiment of this application; Figure 2 This is a schematic diagram of the mold provided in the embodiments of this application; Figure 3 This is one of the structural schematic diagrams of a structural component forming method provided in an embodiment of this application; Figure 4 This is a second schematic diagram of a structural component forming method provided in an embodiment of this application; Figure 5 A second flowchart illustrating a structural component forming method provided in this application embodiment; Figure 6 A flowchart of a structural component forming method provided in this application embodiment; Figure 7 This is a schematic diagram of the skin structure provided in an embodiment of this application; Figure 8 A flowchart of a structural component forming method provided in this application embodiment; Figure 9 This is the third structural schematic diagram of a structural component forming method provided in the embodiments of this application; Figure 10 This is a structural schematic diagram of a structural component provided in an embodiment of this application.

[0017] Icons: 100 - Mold; 110 - First plate; 120 - Second plate; 130 - Third plate; 200 - Prepreg; 210 - Arc area; 300 - Skin; 310 - Bottom skin; 320 - Top skin; 330 - Outer skin; 340 - Through hole; 400 - First semi-permeable membrane; 500 - Second semi-permeable membrane; 600 - Breathable felt; 700 - Vacuum bag; 900 - Structural component; 910 - Fourth plate; 920 - Fifth plate; 930 - Sixth plate. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this application, it should be noted that the terms "center," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] In existing technologies, when fabricating structural parts with small-angle (R < 1.5 mm) arc-shaped regions using autoclave molding, the viscosity of the epoxy resin decreases after heating during the hot-pressing curing process, increasing the lubricity of the prepreg. Simultaneously, the autoclave pressure drives the prepreg to flow towards areas of lower pressure. The geometry of the arc-shaped region prevents the prepreg from being effectively fixed, resulting in prepreg slippage and accumulation near the arc-shaped region, leading to wrinkles in the molded structural parts. Therefore, this application provides a structural part molding method to solve the problem of wrinkles in molded structural parts caused by prepreg accumulation. The technical solution of this application is described in detail below.

[0024] One aspect of the embodiments of this application, such as Figure 1 As shown, a method for forming a structural component is provided, comprising: S100: Provides a mold, which includes a first plate, a second plate and a third plate connected in sequence, with the first plate and the third plate respectively having a rounded transition at the connection with the second plate.

[0025] like Figure 2 As shown, the shape of mold 100 is the same as that of structural component 900. Specifically, mold 100 includes a first plate 110, a second plate 120, and a third plate 130. The first plate 110 is connected to one end of the second plate 120 with a rounded transition at the connection point, and the third plate 130 is connected to the other end of the second plate 120 with a rounded transition at the connection point. The radius corresponding to the rounded transition is R, where R < 1.5 mm. For example, R can be 1.4 mm, 1.3 mm, 1.2 mm, 1.1 mm, or 1 mm, without any specific limitation. The bending direction of the rounded arcs at the connection points of the first plate 110 and the third plate 130 with the second plate 120 can be the same or opposite. For example, the shape of mold 100 can be C-shaped or S-shaped, without any specific limitation.

[0026] S200: Prepreg is laid on the surfaces of the first, second, and third plates of the mold.

[0027] like Figure 3As shown, based on the shapes of the first plate 110, the second plate 120, and the third plate 130, the prepreg 200 is cut using a cutting machine or blade to a shape that can simultaneously cover the surfaces of the three plates. Then, the prepreg 200 is laid on the surfaces of the first plate 110, the second plate 120, and the third plate 130. For example, the second plate 120 is laid first in the middle area of ​​the prepreg 200, and then the first plate 110 and the third plate 130 are laid on the edge areas of the prepreg 200, respectively. Alternatively, the prepreg 200 is laid sequentially along the arrangement direction of the first plate 110, the second plate 120, and the third plate 130 on the mold 100, or sequentially along the arrangement direction of the third plate 130, the second plate 120, and the first plate 110. It should be noted that after laying, a rubber scraper or pressure roller is used to squeeze the prepreg 200 to remove air bubbles between the prepreg 200 and the mold 100.

[0028] In some embodiments, the prepreg 200 can be laid in one, two, three, or four or more layers. The specific number of layers can be laid according to the actual situation and is not specifically limited here.

[0029] In some embodiments, the prepreg 200 is made of unidirectional carbon fiber and epoxy resin or unidirectional glass fiber and epoxy resin, and there is no specific limitation.

[0030] S300: A skin is laid on top of the prepreg. The skin includes a bottom skin and a top skin that are stacked in sequence. The bottom skin covers the arc area of ​​the prepreg, and the top skin covers the prepreg.

[0031] like Figure 4 As shown, after the prepreg 200 is laid on the mold 100, a skin 300 is laid on top of the prepreg 200. The skin 300 includes a bottom skin 310 covering the arcuate region 210 of the prepreg 200 and a top skin 320 covering the entire region of the prepreg 200. That is, the top skin 320 covers the bottom skin 310 and the prepreg 200. During laying, in order to make the bottom skin 310 cover the arcuate region 210, for example, the central area of ​​the skin 300 is first laid in the middle part of the arcuate region 210, and then the skin 300 is pressed towards both ends of the arcuate region 210 using pressure rollers; alternatively, one end of the skin 300 can be laid in one end of the arcuate region 210 first, and then laid in the middle part to the other end of the arcuate region 210 and pressed with pressure rollers. The laying method of the top layer skin 320 is the same as that of the bottom layer skin 310. The middle part of the arc area 210 can be laid first and then the two ends can be laid, or one end can be laid first, then the middle part can be laid and then the other end can be laid. After laying, the skin is compacted with a pressure roller.

[0032] In some implementations, the number of bottom skin layers 310 can be one, two, three, or more, without specific limitation. Similarly, the number of top skin layers 320 can also be one, two, three, or more, without specific limitation. It should be noted that the bottom skin layers 310 and the top skin layers 320 have the same number of layers. For example, as... Figure 4 As shown, the bottom layer skin 310 is one layer, and the top layer skin 320 is also one layer.

[0033] In some implementations, such as Figure 4 As shown, the skin 300 also includes an outer skin 330, which is laid on top of the top skin 320 and covers the arc-shaped area 210 of the prepreg 200. By adding an outer skin 330 that only covers the arc-shaped area 210 on top of the bottom skin 310 and the top skin 320, a triple gradient constraint of local-overall-local is formed. During the hot-press curing process, additional pressure is concentrated on the arc-shaped area where stacking is most likely to occur. The outer skin 330 can act as a physical barrier to prevent epoxy resin from flowing out too quickly before curing, maintain the stability of the fiber and epoxy resin ratio in the arc-shaped area 210, further alleviate the problem of prepreg 200 stacking in the arc-shaped area 210, and improve the flatness of the structural component 900.

[0034] In some embodiments, the number of outer skin layers 330 can be one, two, three, or more, without specific limitation. It should be noted that the number of outer skin layers 330 is the same as the number of layers in the bottom skin layer 310 and the top skin layer 320, for example, as... Figure 4 As shown, the outer skin 330 is also a single layer.

[0035] In some embodiments, the prepreg 200 is made of unidirectional carbon fiber and epoxy resin or unidirectional glass fiber and epoxy resin. The bottom skin 310 is made of the same material as the prepreg 200; for example, the bottom skin 310 can be made of unidirectional carbon fiber and epoxy resin or unidirectional glass fiber and epoxy resin. The top skin 320 and the outer skin 330 are made of silicone rubber. By setting the bottom skin 310 to be the same material as the prepreg 200, during the hot-press curing process, the bottom skin 310 and the prepreg 200 in the arc region 210 are cured together, firmly holding the most slippery interface layer. The top skin 320 and the outer skin 330 are made of silicone rubber. During the hot-press curing process, the silicone rubber flexibly deforms under hot pressure and evenly transmits pressure to the arc region 210 of the prepreg 200, reducing the accumulation in the arc region 210 while improving the surface quality of the structural component 900.

[0036] S400: Hot-pressed prepreg is cured to form structural components.

[0037] Specifically, the mold 100, with the skin 300 and prepreg 200 laid on it, is first placed in an autoclave. The temperature of the autoclave is controlled to rise from room temperature to 90°C at a rate of 1°C / min and held for 40 minutes. During this process, the autoclave is not pressurized (remains at atmospheric pressure). The slow temperature rise avoids thermal shock and ensures a uniform temperature field between the mold 100 and the prepreg 200, providing a gentle preheating and impregnation environment for the unidirectional fibers, while avoiding premature pressurization that could cause epoxy resin loss. At this time, the epoxy resin in the bottom skin 310 begins to soften as the temperature rises and begins to fuse with the prepreg 200 in the arc region 210. The top skin 320 maintains close contact with the bottom skin 310 and the prepreg 200 below it, while the outer skin 330 maintains additional pressure in the arc region 210 to prevent fiber slippage after the epoxy resin softens.

[0038] Next, the pressure in the autoclave is increased from normal atmospheric pressure to 0.3 MPa at a rate of 0.1 MPa / 10 min, and the temperature is increased to 100°C at a rate of 1°C / min and held for 90 min. This slow pressurization allows air to escape from the fiber bundles, while the 90-min holding at 100°C allows the epoxy resin to flow out and fill the fiber gaps. Slow pressurization and heat treatment within the optimal flow window of the epoxy resin simultaneously complete venting, impregnation, and compaction, preventing the unidirectional fibers from being squeezed out or deformed under high pressure. At this point, since the bottom skin 310 and the prepreg 200 are made of the same material, the epoxy resin in the bottom skin 310 fully impregnates the interface and locks the fibers in the arc region 210 in place. Simultaneously, the outer skin 330 applies additional pressure to the arc region 210, forming a localized high-pressure zone that actively inhibits fiber slippage. The top layer skin 320 adapts to the shape of the overall prepreg 200 through flexible deformation, and uniformly transmits the 0.3MPa can pressure, so that the pressure in the flat area and the arc area 210 of the prepreg 200 is consistent, reducing fiber slippage driven by pressure gradient.

[0039] Then, the pressure in the autoclave is increased from 0.1 MPa to 0.6 MPa at 10 min, and the temperature is increased to 140℃ at 1℃ / min and held for 100 min. When the pressure reaches its maximum and the temperature is at the optimal curing temperature of the epoxy resin, the epoxy resin begins to cross-link, and the unidirectional fibers are fixed in their final positions, forming structural component 900. At this point, the bottom skin 310 and the prepreg 200 of the arc region 210 are completely cured together, and the fiber positions of the arc region 210 are fixed. The top skin 320 evenly transmits the 0.6 MPa pressure, while the silicone rubber remains flexible. The outer skin 330 applies even higher pressure to the arc region 210, ensuring that the arc region 210 is continuously compressed during the epoxy resin gelation process.

[0040] Then, the temperature of the autoclave is reduced to 60℃ at a rate of 0.5℃ / min while maintaining the pressure at 0.6 MPa. The autoclave is then allowed to cool naturally to room temperature before being depressurized. By lowering the temperature, shrinkage or warping of structural component 900 is prevented. At this point, the bottom skin 310 has solidified into the structural component 900, acting as a rigid structure to transfer and withstand shrinkage stress. The elastic deformation of the top skin 320 absorbs shrinkage strain, reducing residual stress transmitted to the structural component 900. The outer skin 330 absorbs additional shrinkage stress in the arc region 210, preventing microcracks from forming in this area due to stress concentration.

[0041] This application lays a skin 300 on the prepreg 200. The skin 300 includes a bottom skin 310 and a top skin 320. The bottom skin 310 only covers the prepreg 200 in the arc area 210, which plays a local anchoring role and prevents the prepreg 200 in the arc area 210 from sliding and accumulating at both ends during the hot-press curing process. The top skin 320 covers the entire area of ​​the prepreg 200, which provides overall constraint and prevents the prepreg 200 in the flat area from sliding into the arc area 210 during the hot-press curing process and evenly distributes the pressure. Through the synergistic effect of the bottom skin 310 and the top skin 320, the flow of the prepreg 200 is jointly controlled during the hot-press curing process, which greatly alleviates the problem of prepreg 200 accumulation in the arc area 210 and improves the flatness of the structural component 900.

[0042] Optionally, such as Figure 5 As shown, S300: A skin is laid on top of the prepreg, the skin comprising a bottom skin and a top skin stacked sequentially, the bottom skin covering the arcuate area of ​​the prepreg, and before the top skin covers the prepreg, the method further includes: S500: Extruding the prepreg along the fiber extension direction to remove air bubbles between the prepreg and the die.

[0043] The prepreg 200 in this application is made of unidirectional fibers arranged in parallel. Tiny grooves exist between the fiber bundles, and extrusion along the fiber extension direction can more effectively remove air bubbles between the prepreg 200 and the mold 100. For example, using a rubber scraper or pressure roller to perform unidirectional scraping along the direction from the first plate 110 to the third plate 130 improves the air bubble removal effect. When the prepreg 200 has multiple layers, air venting is required after each layer is laid. This step can significantly reduce the porosity of the structural component 900 and prevent delamination defects caused by air bubble aggregation.

[0044] Optionally, such as Figure 5 As shown, S500: After extruding the prepreg along the fiber extension direction to remove air bubbles between the prepreg and the mold, the method further includes: S600: A first semi-permeable membrane is laid over the prepreg, which allows gas inside the prepreg to pass through and prevents the prepreg from flowing.

[0045] By laying a first semi-permeable membrane 400 on top of the prepreg 200, gas can be effectively discharged between the prepreg 200 and the mold 100 and between the prepregs 200 during the hot-press curing process, while preventing epoxy resin loss and maintaining the pressure stability of the epoxy resin, thereby reducing the porosity of the structural component 900 and improving the surface quality of the simple structure.

[0046] Optionally, such as Figure 6 As shown, S300: A skin is laid on top of the prepreg, the skin comprising a bottom skin and a top skin stacked sequentially, the bottom skin covering the arc-shaped area of ​​the prepreg, and after the top skin covers the prepreg, the method further includes: S700: Through holes are provided on the skin, and the arc-shaped areas of the through holes prepreg are corresponding. like Figure 7 As shown, through holes 340 are opened on the skin 300. Through holes 340 provide a vertical exhaust channel for the gas in the arc region 210, significantly shortening the exhaust path and solving the problem of bubble aggregation caused by the geometry of the arc region 210. By forming an efficient local exhaust system with the first semi-permeable membrane 400 and the second semi-permeable membrane 500 mentioned below, the breathable felt 600 and the vacuum bag 700, the fit of the skin 300 is improved and the porosity of the structural component 900 is reduced.

[0047] In some implementations, through holes 340 are only formed on the top skin 320 and the outer skin 330.

[0048] In some implementations, such as Figure 7 As shown, there are multiple through holes 340, which are arranged at intervals along the arc region 210. The distance between two adjacent through holes 340 is L, 100mm≤L≤500mm. For example, the distance can be 100mm, 150mm, 200mm, 300mm, 400mm, or 500mm, and there is no specific limitation. The diameter of the through holes 340 is Φ, 2mm≤Φ≤3mm. For example, the diameter can be 2mm, 2.5mm, 2.8mm, or 3mm. By setting a larger hole spacing and a smaller hole diameter, it is possible to prevent epoxy resin from being sucked out.

[0049] Optionally, such as Figure 8 As shown, S400: Before the hot-pressed prepreg is cured to form a structural component, the method further includes: S800: A second semi-permeable membrane, a breathable felt, and a vacuum bag are sequentially stacked on the skin.

[0050] S900: Vacuum bag sealing mold.

[0051] like Figure 9 As shown, the second semi-permeable membrane 500 is a very thin, microporous film that allows air to escape. A fiber mat is laid on the separating membrane, providing a three-dimensional airflow channel; for example, the fiber mat can be fiberglass cloth. Finally, a vacuum bag 700 is laid on top, and the edges of the vacuum bag 700 and the mold 100 are sealed with sealant, thus encapsulating the mold 100 and the prepreg 200, the first semi-permeable membrane 400, the skin 300, the second semi-permeable membrane 500, and the breathable felt 600 above the mold 100 in a sealed space.

[0052] S1000: Exhaust the vacuum bag to -0.08MPa and maintain the pressure for 30-60 minutes.

[0053] Connect the vacuum bag 700 to the vacuum pump and evacuate the internal pressure to -0.08 MPa (relative pressure, i.e., 0.08 MPa lower than atmospheric pressure). Then close the valve and maintain the pressure for 30-60 minutes, for example, 30, 40, 50, or 60 minutes, the specific duration is not limited. This gentle and stable vacuuming method prevents slippage of the prepreg 200 and the skin 300. The prolonged pressure maintenance ensures sufficient venting and pre-compaction, while also facilitating leak detection. At this point, the bottom skin 310 initially contacts the prepreg 200 in the arc region 210, and the vacuum negative pressure presses it firmly into the arc region 210. The outer skin 330 increases local pressure in the arc region 210, pre-compacting the area most prone to buildup. The top skin 320 flexibly deforms, transferring the vacuum negative pressure to all areas below it. This process begins to suppress the slippage of the prepreg 200, preparing for the hot-pressing curing process.

[0054] Optionally, S200: Before laying the prepreg 200 on the surfaces of the first plate 110, the second plate 120, and the third plate 130 of the mold 100, the method further includes: Use sandpaper to polish mold 100. First, coarsely polish mold 100 with 800-grit sandpaper, then further polish with 1200-grit sandpaper, and finally finely polish with 2000-grit sandpaper to ensure a smooth, burr-free surface. Then, clean mold 100 sequentially with acetone and anhydrous ethanol to remove oil and impurities from its surface. Finally, apply a release agent to mold 100 and let it stand for 15-20 minutes (e.g., 15, 16, 17, 18, 19, or 20 minutes) to form a release layer. This release layer facilitates the release of structural component 900 from mold 100 after heat pressing and curing. It should be noted that the release agent can be a water-based semi-permanent release agent or a wax-based release agent; there are no specific restrictions.

[0055] Another aspect of the embodiments of this application, such as Figure 10 As shown, a structural component 900 is provided, comprising a structural component 900 prepared using the above-described structural component 900 molding method. The structural component 900 includes a fourth plate 910, a fifth plate 920, and a sixth plate 930 connected in sequence. The fourth plate 910 and the sixth plate 930 are respectively connected to the fifth plate 920 with rounded transitions. The structural component 900 prepared by the above-described structural component 900 molding method can greatly alleviate the problem of prepreg 200 accumulation in the rounded area 210 of the structural component 900, and improve the flatness and quality of the structural component 900.

[0056] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for forming a structural component, characterized in that, include: A mold is provided, the mold comprising a first plate, a second plate and a third plate connected in sequence, wherein the first plate and the third plate are respectively connected to the second plate by a rounded transition; Prepreg is laid on the surfaces of the first, second, and third plates of the mold; A skin is laid on top of the prepreg, the skin comprising a bottom skin and a top skin stacked in sequence, the bottom skin covering the arc area of ​​the prepreg, and the top skin covering the prepreg; The prepreg is hot-pressed to cure it and form a structural component.

2. The structural component forming method as described in claim 1, characterized in that, The skin also includes an outer skin layer, which is laid on top of the top skin layer and covers the arc-shaped area of ​​the prepreg.

3. The structural component forming method as described in claim 2, characterized in that, The prepreg is made of unidirectional carbon fiber and epoxy resin or unidirectional glass fiber and epoxy resin. The bottom skin is made of the same material as the prepreg, and the top skin and the outer skin are made of silicone rubber.

4. The structural component forming method as described in claim 3, characterized in that, The method further includes laying a skin over the prepreg, the skin comprising a bottom skin and a top skin stacked sequentially, the bottom skin covering the arcuate region of the prepreg, and before the top skin covers the prepreg, the method further includes: The prepreg is squeezed along the fiber extension direction to expel air bubbles between the prepreg and the mold.

5. The structural component forming method as described in claim 4, characterized in that, After extruding the prepreg along its fiber extension direction to remove air bubbles between the prepreg and the mold, the method further includes: A first semi-permeable membrane is laid over the prepreg, the first semi-permeable membrane being used to allow gas inside the prepreg to pass through and to prevent the prepreg from flowing.

6. The structural component forming method according to any one of claims 1 to 5, characterized in that, The method further includes laying a skin over the prepreg, the skin comprising a bottom skin and a top skin stacked sequentially, the bottom skin covering the arcuate area of ​​the prepreg, and the top skin covering the prepreg. Through holes are provided on the skin, and the through holes correspond to the arc-shaped areas of the prepreg.

7. The structural component forming method as described in claim 6, characterized in that, The number of through holes is multiple, and the multiple through holes are arranged at intervals along the arc area. The distance between two adjacent through holes is L, 100mm≤L≤500mm, and the diameter of the through holes is Φ, 2mm≤Φ≤3mm.

8. The structural component forming method according to any one of claims 1 to 5, characterized in that, Before the prepreg is cured by hot pressing to form a structural component, the method further includes: A second semi-permeable membrane, a breathable felt, and a vacuum bag are sequentially stacked on the skin. Seal the mold with the vacuum bag; The vacuum bag is vented to -0.08 MPa and held at that pressure for 30-60 minutes.

9. The structural component forming method according to any one of claims 1 to 5, characterized in that, The prepreg material is hot-pressed and cured to form a structural component, including: The mold covered with the skin is placed in an autoclave; The temperature of the autoclave is first increased from room temperature to 90°C at a rate of 1°C / min and held for 40 minutes. Then, the pressure of the autoclave is increased from normal atmospheric pressure to 0.3 MPa at a rate of 0.1 MPa / 10 minutes, and the temperature is increased to 100°C at a rate of 1°C / min and held for 90 minutes. Next, the pressure of the autoclave is increased to 0.6 MPa at a rate of 0.1 MPa / 10 minutes, and the temperature is increased to 140°C at a rate of 1°C / min and held for 100 minutes. Then, the temperature of the autoclave is decreased to 60°C at a rate of 0.5°C / min, and the pressure of the autoclave is maintained at 0.6 MPa. Finally, the autoclave is allowed to cool naturally to room temperature before the pressure is released.

10. A structural component, characterized in that, The structural component includes a structural component manufactured using the structural component forming method according to any one of claims 1 to 9, the structural component comprising a fourth plate, a fifth plate and a sixth plate connected in sequence, wherein the fourth plate and the sixth plate are respectively connected to the fifth plate by a rounded transition.

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