A soft mold suitable for large-thickness and large-size composite R-angle structure

Abstract

The application discloses a soft mold suitable for R-angle structure of large-thickness and large-size composite materials, which comprises an upper forming layer and a lower forming layer, a reinforcing layer and a flexible R-angle reinforcing layer; the upper forming layer and the lower forming layer are continuous integral structure layers respectively, the reinforcing layer and the flexible R-angle reinforcing layer are combined and connected in a splicing form in the same paving plane to form a continuous composite reinforcing layer, and the reinforcing layer and the flexible R-angle reinforcing layer are paved between the upper forming layer and the lower forming layer. The application solves the problem that when a composite material component with an R-angle structure is formed by using a traditional soft mold, a bridging phenomenon occurs in the R-angle area, so that the forming pressure cannot be effectively conducted to the R-angle position of the component, and the forming quality of the component is seriously affected.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of composite material molding and manufacturing technology, and particularly to a soft mold suitable for molding large-thickness, large-size composite material R-angle structures. Background Technology

[0002] For composite material components formed by autoclave molding, a soft mold is used as the pressure transmission medium during the molding process. The soft mold is used in conjunction with a rigid mold, and the composite prepreg is compacted and cured by applying high temperature and high pressure in the autoclave, thereby obtaining a part with precise shape and high internal quality.

[0003] Currently, a widely used traditional flexible mold in the industry employs a three-layer composite structure. This structure consists of two uncured rubber layers on the top and bottom, and a multi-layer composite prepreg layer sandwiched in the middle. The multi-layer prepreg in the middle provides the necessary support and shape stability for the flexible mold as a whole, while the top and bottom rubber layers are responsible for uniformly transmitting pressure and conforming to the molded surface during the curing process.

[0004] The aforementioned traditional soft mold structure has significant limitations in practical applications. When applied to composite material components with rounded corners, the prepreg layer in the middle of the soft mold has high rigidity and the fibers are not easily stretched, so "bridging" is prone to occur in the rounded corner area. This makes it impossible for the soft mold surface to fully conform to and fit the composite material surface, thus seriously affecting the molding quality of the part. Summary of the Invention

[0005] The purpose of this invention is to provide a soft mold suitable for molding R-corner structures of composite materials with large thickness and large size, so as to solve the problem that when molding composite material components with R-corner structures using traditional soft molds, bridging occurs in the R-corner area, which makes it impossible to effectively transmit molding pressure to the R-corner position of the part, thus seriously affecting the molding quality of the part.

[0006] The technical solution of the present invention is as follows: The present invention provides a molding soft mold suitable for the R-angle structure of composite materials with large thickness and large size, including: an upper shaping layer 1 and a lower shaping layer 2, a reinforcing layer 3, and a flexible R-angle reinforcing layer 4; The upper shaping layer 1 and the lower shaping layer 2 are continuous integral structural layers. The reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are combined and connected in a splicing manner on the same laying plane to form a continuous composite reinforcing layer. The reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are laid between the upper shaping layer 1 and the lower shaping layer 2.

[0007] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, The lower molding layer 2 has the same geometric surface as the outer or inner upper surface of the composite material part 6 where the molding soft mold is located.

[0008] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, Both the upper shaping layer 1 and the lower shaping layer 2 are uncured non-silicone rubber.

[0009] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, The reinforcing layer 3 is an uncured prepreg laminate, and the number of prepreg layers in the reinforcing layer 3 is 1 to 8. The reinforcing layer 3 is obtained by cutting the prepreg laminate formed by laying and splicing. After curing, the reinforcing layer 3 is used to provide rigid support to ensure the accuracy of the shaped surface.

[0010] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, The reinforcing layer 3 is a resin prepreg laminate reinforced with carbon fiber or glass fiber, and the resin system is one or more of epoxy resin, bismaleimide resin, polyimide resin, and cyanate resin.

[0011] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, The width of the reinforcing layer 3 covering the upper surface of the composite material part is the same as the width of the upper surface of the composite material part; the width of the reinforcing layer 3 covering the side surface of the composite material part is greater than the width of the side surface of the composite material part.

[0012] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, The flexible R-angle reinforcement layer 4 is an uncured flexible material, including: uncured non-silicone rubber or uncured sealing strip; and the width of the flexible R-angle reinforcement layer 4 is: W ≥ πr / 2, where r is the R-angle radius of the composite material part.

[0013] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, The upper and lower surfaces of the composite reinforcing layer formed by the reinforcing layer 3 and the flexible R-angle reinforcing layer 4 are respectively bonded to the upper shaping layer 1 and the lower shaping layer 2, and after curing and vulcanization molding, it can cover the upper shaping layer 1 and the lower shaping layer 2.

[0014] Optionally, as described above, in the molding soft mold suitable for large-thickness, large-size composite material R-angle structures, After the upper shaping layer 1, lower shaping layer 2, reinforcing layer 3 and flexible R-corner reinforcing layer 4 of the molding soft mold are combined and formed, they are simultaneously cured and vulcanized to obtain a molding soft film for R-corner forming of composite material parts, and the flexible R-corner reinforcing layer 4 is flexible after vulcanization.

[0015] The beneficial effects of this invention are as follows: This invention provides a molding soft mold suitable for large-thickness, large-size composite material R-angle structures. In this molding soft mold, the upper shaping layer 1 and the lower shaping layer 2 are continuous integral structural layers. The reinforcing layer 3 and the flexible R-angle reinforcing layer 4 are combined and connected in a splicing manner on the same laying plane to form a continuous composite reinforcing layer. Furthermore, the reinforcing layer 3 and the flexible R-angle reinforcing layer 4 are laid between the upper shaping layer 1 and the lower shaping layer 2. After the above four-layer structure is combined and molded, it undergoes simultaneous curing and vulcanization treatment to obtain a molding soft mold for R-angle molding of composite material parts. The molding soft mold provided by the embodiments of this invention has the following beneficial effects: The cured prepreg laminate (i.e., reinforcing layer 3) provides rigid support to ensure the accuracy of the molding surface. The flexible rubber surface (i.e., upper and lower molding layers) facilitates the soft mold to pressurize and mold the surface of the composite material part. In addition, by replacing the prepreg laminate in the reinforcing area of ​​the R-corner in the traditional soft mold with other flexible materials such as uncured non-silicone rubber or sealing strip material that still have flexibility after vulcanization, the deformation allowance during the pressurization process is retained, which improves the fit between the soft mold and the part during part encapsulation. It avoids internal defects and surface quality problems caused by the soft mold bridging at the R-corner of the composite material part, and can further guarantee and improve the molding quality of the product. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0017] Figure 1 A schematic diagram of a multi-layer composite structure of a molding soft mold suitable for forming large-thickness, large-size composite material R-angle structures is provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the molding structure of a soft mold suitable for forming large-thickness, large-size composite material R-angle structures provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the molding structure of a soft mold suitable for forming large-thickness, large-size composite material R-angle structures, provided in Embodiment 1 of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0019] As explained in the background section, the traditional soft film has a structural composition and function in the autoclave molding process of composite components, and there are problems with the application of traditional soft film to composite components with rounded corners. Specifically, "bridging" is prone to occur in the rounded corner area, which seriously affects the molding quality of the part. In particular, the "bridging" phenomenon in the rounded corner area makes it impossible to effectively transmit the molding pressure to the rounded corner position of the part, resulting in problems such as resin enrichment, thickness deviation, insufficient surface accuracy, porosity, and delamination in the rounded corner area of ​​the composite material.

[0020] To address the aforementioned issues, a new soft mold technology is urgently needed to significantly improve the fit between the soft mold and the R-angle region of the composite material component, as well as the pressure transmission efficiency, thereby solving the problems and ensuring the molding quality of the parts.

[0021] Based on the above requirements, this invention provides a soft mold suitable for forming large-thickness, large-size composite material R-angle structures.

[0022] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0023] Figure 1 This invention provides a schematic diagram of a soft mold suitable for forming large-thickness, large-size composite material R-angle structures. (See diagram below.) Figure 1 As shown, the molding soft mold for the composite material R-angle structure provided by the present invention consists of a three-layer structure, including: an upper shaping layer 1, a lower shaping layer 2, a reinforcing layer 3, and a flexible R-angle reinforcing layer 4.

[0024] like Figure 1 As shown, in the molded soft film provided in this embodiment of the invention, the upper shaping layer 1 and the lower shaping layer 2 are continuous integral structural layers, and the reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are combined and connected in a splicing manner on the same laying plane to form a continuous composite reinforcing layer; and the reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are laid between the upper shaping layer 1 and the lower shaping layer 2.

[0025] In one implementation of this invention, the lower molding layer 2 has the same geometric surface as the outer or inner upper molding surface of the composite material part 6 where the molding soft mold is located; for example... Figure 2 and Figure 3 As shown, the composite material part is, for example, a U-shaped or inverted U-shaped structure. Based on the different shapes of the part, a lower shaping layer 2 is formed to match the shape of the part.

[0026] In one embodiment of the present invention, before the four-layer structure is assembled, the upper molding layer 1 and the lower molding layer 2 are both uncured non-silicone rubber. Since the upper molding layer 1 and the lower molding layer 2 have a certain hardness after curing, they are not easy to be molded. Therefore, uncured non-silicone rubber is used as the molding layer when assembling the multi-layer structure. After the four-layer structure is spliced, it is molded on the molding mold of the part and cured and vulcanized.

[0027] In one embodiment of the present invention, the reinforcing layer 3 is an uncured prepreg laminate, and the number of prepreg layers in the reinforcing layer 3 is 1 to 8. The reinforcing layer 3 for splicing is obtained by cutting the prepreg laminate formed by splicing. After curing, the reinforcing layer 3 is used to provide rigid support to ensure the accuracy of the shaped surface.

[0028] In one embodiment of the present invention, the reinforcing layer 3 is a resin prepreg laminate reinforced with carbon fiber or glass fiber, and the resin system is one or more of epoxy resin, bismaleimide resin, polyimide resin, and cyanate resin.

[0029] In this implementation, the width of the reinforcing layer 3 covering the upper surface of the composite material part is the same as the width of the upper surface of the composite material part; the width of the reinforcing layer 3 covering the side surface of the composite material part is slightly larger than the width of the side surface of the composite material part.

[0030] In one implementation of this invention, the flexible R-corner reinforcement layer 4 is an uncured flexible material, including: uncured non-silicone rubber or uncured sealing strip; and the width of the flexible R-corner reinforcement layer 4 is: W ≥ πr / 2, where r is the R-corner radius of the composite material part.

[0031] In one embodiment of the present invention, the upper and lower surfaces of the composite reinforcing layer formed by the reinforcing layer 3 and the flexible R-angle reinforcing layer 4 are respectively bonded to the upper shaping layer 1 and the lower shaping layer 2, and after curing and vulcanization molding, it can cover the upper shaping layer 1 and the lower shaping layer 2.

[0032] It should be noted that after the upper shaping layer 1, lower shaping layer 2, reinforcing layer 3 and flexible R-corner reinforcing layer 4 of the molding soft mold are combined and formed, they need to undergo simultaneous curing and vulcanization treatment. For the prepreg layer (i.e. reinforcing layer 3), the curing treatment is performed, and for the rubber, the vulcanization treatment is performed. In this embodiment of the invention, the curing and vulcanization are carried out in the same thermal field. The molding soft film obtained by simultaneous treatment is used for R-corner forming of composite material parts, and the flexible R-corner reinforcing layer 4 is flexible after vulcanization.

[0033] This invention provides a molding soft mold suitable for forming large-thickness, large-size composite material R-corner structures. In this molding soft mold, the upper shaping layer 1 and the lower shaping layer 2 are continuous integral structural layers. The reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are combined and connected in a splicing manner on the same laying plane to form a continuous composite reinforcing layer. The reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are laid between the upper shaping layer 1 and the lower shaping layer 2. After the above four-layer structure is molded, it undergoes simultaneous curing and vulcanization treatment to obtain a molding soft mold for forming R-corners of composite material parts. The molding soft mold provided by this invention has the following beneficial effects: The cured prepreg laminate (i.e., reinforcing layer 3) provides rigid support to ensure the accuracy of the molding surface. The flexible rubber surface (i.e., upper and lower molding layers) facilitates the soft mold to pressurize and mold the surface of the composite material part. In addition, by replacing the prepreg laminate in the reinforcing area of ​​the R-corner in the traditional soft mold with other flexible materials such as uncured non-silicone rubber or sealing strip material that still have flexibility after vulcanization, the deformation allowance during the pressurization process is retained, which improves the fit between the soft mold and the part during part encapsulation. It avoids internal defects and surface quality problems caused by the soft mold bridging at the R-corner of the composite material part, and can further guarantee and improve the molding quality of the product.

[0034] The following examples illustrate the implementation of the molding soft mold provided by the present invention, which is suitable for large-thickness, large-size composite material R-angle structures.

[0035] Implementation Example 1 A certain composite material beam is manufactured using a male mold forming method. The upper mold surface is 1000 mm wide, the left and right side mold surfaces are 150 mm high, and the radius of the rounded corners is 20 mm. The prepreg of the part is laid on the forming fixture using a U-shaped structure of the male mold. For example... Figure 2 As shown, the technical solution of this embodiment example 1 is as follows: (1) The lower molding layer 2 has the same geometric surface as the outer upper molding surface of the composite material part 6 where the molding soft mold is located; (2) The upper shaping layer 1 and the lower shaping layer 2 are continuous integral structures; the reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are combined and connected in the same laying plane in a splicing form to form a continuous composite reinforcing layer; the reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are laid between the upper shaping layer 1 and the lower shaping layer 2. (3) The upper molding layer 1 and the lower molding layer 2 are uncured non-silicone rubber; (4) The reinforcing layer 3 is a carbon fiber reinforced resin prepreg laminate, and the resin system is bismaleimide resin.

[0036] (5) The number of reinforcing layers 3 is 6. The width of the reinforcing layer 3 covering the upper surface of the composite material part 6 is 1000 mm, and the height of the reinforcing layer 3 covering the left and right sides of the composite material part 6 is 150 mm.

[0037] (6) The flexible R-angle reinforcing layer 4 is made of uncured non-silicone rubber with a width of W = 32 mm; (7) The composite reinforcing layer formed by the reinforcing layer 3 and the flexible R-angle reinforcing layer 4 is continuous and is bonded to the upper shaping layer 1 and the lower shaping layer 2. After curing and vulcanization, it can cover the upper shaping layer 1 and the lower shaping layer 2.

[0038] (8) The lower shaping layer 2 is attached to the upper surface of the part 6 where the soft mold is located, and the overall width of the lower shaping layer 2 is 1364 mm.

[0039] Implementation Example 2 A composite beam has an inner top profile width of 800 mm, left and right side profile widths of 100 mm, and a radius of 15 mm for its corners. The prepreg is laid on the molding fixture using a U-shaped female mold. For example... Figure 3 As shown, the technical solution of this implementation example 2 is as follows: (1) The lower molding layer 2 has the same geometric surface as the upper inner surface of the composite material part 6 where the molding soft mold is located; (2) The upper shaping layer 1 and the lower shaping layer 2 are continuous integral structures; the reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are combined and connected in the same laying plane in a splicing form to form a continuous composite reinforcing layer; the reinforcing layer 3 and the flexible R-corner reinforcing layer 4 are laid between the upper shaping layer 1 and the lower shaping layer 2. (3) The upper molding layer 1 and the lower molding layer 2 are uncured non-silicone rubber; (4) The reinforcing layer 3 is a carbon fiber reinforced resin prepreg laminate, and the resin system is epoxy resin.

[0040] (5) There are 4 layers of reinforcing layer 3. The width of the inner upper surface of the composite material part covered by reinforcing layer 3 is 800 mm, and the width of the left and right sides of the composite material part 6 is 100 mm.

[0041] (6) The flexible R-corner reinforcement layer 4 is an uncured sealing strip with a width of W=24mm; (7) The composite reinforcing layer formed by the reinforcing layer 3 and the flexible R-angle reinforcing layer 4 is continuous and is bonded to the upper shaping layer 1 and the lower shaping layer 2. After curing and vulcanization, it can cover the upper shaping layer 1 and the lower shaping layer 2.

[0042] (8) The lower molding layer 2 is attached to the upper surface of the part 6 where the soft mold is located, and the width is 1048 mm.

[0043] It should be noted that the above-mentioned invention... Figure 2 and Figure 3The implementation example shown is based on a composite material part being U-shaped or inverted U-shaped. In reality, composite material parts may also be L-shaped, W-shaped, M-shaped, or other shapes with R-angle structures.

[0044] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A flexible mold suitable for forming large-thickness, large-size composite material R-angle structures, characterized in that, include: The upper shaping layer (1), the lower shaping layer (2), the reinforcement layer (3), and the flexible R-angle reinforcement layer (4); Among them, the upper shaping layer (1) and the lower shaping layer (2) are continuous integral structural layers, and the reinforcement layer (3) and the flexible R-corner reinforcement layer (4) are combined and connected in the same laying plane in a splicing form to form a continuous composite reinforcement layer; and the reinforcement layer (3) and the flexible R-corner reinforcement layer (4) are laid between the upper shaping layer (1) and the lower shaping layer (2).

2. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 1, characterized in that, The lower shaping layer (2) has the same geometric surface as the outer or inner upper surface of the composite material part (6) where the molding soft mold is located.

3. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 1, characterized in that, Both the upper shaping layer (1) and the lower shaping layer (2) are uncured non-silicone rubber.

4. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 1, characterized in that, The reinforcing layer (3) is an uncured prepreg laminate, and the number of prepreg layers in the reinforcing layer (3) is 1 to 8. The reinforcing layer (3) is obtained by cutting the prepreg laminate formed by the layup; and the reinforcing layer (3) is used to provide rigid support after curing to ensure the accuracy of the shaped surface.

5. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 4, characterized in that, The reinforcing layer (3) is a resin prepreg laminate reinforced with carbon fiber or glass fiber, and the resin system is one or more of epoxy resin, bismaleimide resin, polyimide resin, and cyanate resin.

6. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 1, characterized in that, The width of the reinforcing layer (3) covering the upper surface of the composite material part is the same as the width of the upper surface of the composite material part; the width of the reinforcing layer (3) covering the side surface of the composite material part is greater than the width of the side surface of the composite material part.

7. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 1, characterized in that, The flexible R-angle reinforcement layer (4) is an uncured flexible material, including: uncured non-silicone rubber or uncured sealing strip; and the width of the flexible R-angle reinforcement layer (4) is: W ≥ πr / 2, where r is the R-angle radius of the composite material part.

8. The molding soft mold for forming large-thickness, large-size composite material R-angle structures according to claim 1, characterized in that, The upper and lower surfaces of the composite reinforcement layer formed by the reinforcement layer (3) and the flexible R-angle reinforcement layer (4) are respectively attached to the upper shaping layer (1) and the lower shaping layer (2), and after curing and vulcanization molding, they can cover the upper shaping layer (1) and the lower shaping layer (2).

9. A flexible mold for forming large-thickness, large-size composite material R-angle structures according to any one of claims 1 to 8, characterized in that, After the upper shaping layer (1), lower shaping layer (2), reinforcing layer (3) and flexible R-corner reinforcing layer (4) of the molding soft mold are combined and formed, the molding soft film is obtained by synchronous curing and vulcanization treatment for R-corner forming of composite material parts, and the flexible R-corner reinforcing layer (4) is flexible after vulcanization.

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