Carbon fiber forming mold having a honeycomb sandwich structure

Abstract

The utility model provides a kind of carbon fiber forming die with honeycomb sandwich structure, the carbon fiber forming die with honeycomb sandwich structure includes first carbon fiber bottom plate, second carbon fiber bottom plate, rigid frame and polyimide film sequentially arranged from bottom to top;The rigid frame is filled with honeycomb panel.The carbon fiber forming die with honeycomb sandwich structure of the utility model significantly improves the overall dimensional stability of product, ensures that product obtains excellent dimensional accuracy in forming process, meets subsequent use requirement.

Description

Technical Field

[0001] This utility model relates to the field of mold technology, and in particular to a carbon fiber molding mold with a honeycomb sandwich structure. Background Technology

[0002] In recent years, with the increasingly widespread application of high-performance carbon fiber composite materials in aerospace, automotive and other fields, higher requirements have been placed on the precision of molding dies. Traditional carbon fiber molding dies face significant limitations in meeting these stringent requirements, making it difficult to reliably guarantee the dimensional accuracy of products. They also suffer from high manufacturing costs and limited service life, thus restricting production efficiency and economic benefits.

[0003] CN112536945A discloses a molding die for carbon fiber parts, comprising: a die body, one or more movable inserts, a drilling device, and a bonding device; the die body has a carbon fiber part forming cavity, the movable inserts are detachably mounted on the wall and / or bottom surface of the carbon fiber part forming cavity, the drilling device is detachably mounted on the movable inserts, and the bonding device is mounted on the bonding fixing surface of the movable inserts. This molding die and molding method for carbon fiber parts integrates curing, drilling, and bonding functions into one unit through the design of the movable inserts, drilling device, and bonding device. This allows the vacuum flow molding, drilling, and bonding processes of carbon fiber composite materials to be completed within the same die, effectively shortening the processing cycle, reducing the number of dies, and saving development costs for carbon fiber composite parts.

[0004] CN208629951U discloses a rough forming mold for carbon fiber products, including an upper mold and a lower mold. An upper forming groove is provided on the lower surface of the upper mold, and a lower forming groove is provided on the upper surface of the lower mold, opposite to the upper forming groove. The upper and lower forming grooves form a forming cavity. An air-bag inner mold is provided within the forming cavity. A non-woven fabric layer with a porous structure is provided between the air-bag inner mold and the cavity wall. The non-woven fabric layer includes at least two carbon fiber substrate layers, with a carbon felt layer forming an air layer between adjacent carbon fiber substrate layers. By utilizing the excellent porosity of the non-woven fabric layer of the carbon fiber substrate, resin can be absorbed uniformly. During high-pressure curing of the carbon fiber product, an air layer is formed in the middle, reducing the curing speed of the outer resin layer. Furthermore, the porous structure of the non-woven fabric layer enhances the resin flowability of the product, carrying away air from the interlayer and achieving defoaming.

[0005] CN219256524U discloses a molding die for a carbon fiber T-shaped component, including an upper die and a lower die. The lower die has a side-opening groove, and a slider is provided in the groove through the side opening. The groove and / or the slider at the mating surface of the groove and the slider have an inner groove. The upper surfaces of the lower die and the upper surfaces of the slider on the left and right sides above the inner groove have outer grooves respectively. A pushing block is installed below the upper die to push the slider towards the inner side of the groove. The upper die is fastened above the lower die and the slider. The pushing block pushes the slider into the groove and locks it in the groove. The inner groove, the outer groove and the lower surface of the upper die form a T-shaped component molding cavity.

[0006] However, the aforementioned carbon fiber molding molds still have the problem of low dimensional accuracy of the products after molding. Utility Model Content

[0007] In view of the problems existing in the prior art, the present invention provides a carbon fiber molding die with a honeycomb sandwich structure. The carbon fiber material is used as the base plate, and a honeycomb plate is filled in the rigid frame to form a sandwich, which solves the shortcomings of the existing carbon fiber molding die in terms of precision control. The carbon fiber molding die with a honeycomb sandwich structure significantly improves the overall dimensional stability of the product, ensures that the product obtains excellent dimensional accuracy during the molding process, and meets the requirements of subsequent use.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] This utility model provides a carbon fiber molding die with a honeycomb sandwich structure. The carbon fiber molding die with a honeycomb sandwich structure includes a first carbon fiber base plate, a second carbon fiber base plate, a rigid frame and a polyimide film arranged sequentially from bottom to top; the rigid frame is filled with a honeycomb plate.

[0010] The carbon fiber molding die with a honeycomb sandwich structure described in this invention uses a first carbon fiber base plate with a low coefficient of thermal expansion as a substrate. This base plate can fix the molding die and prevent dimensional deviations caused by expansion and contraction during vacuum forming, effectively solving the shortcomings of traditional molds in precision control. A stable molding die structure is formed by sequentially setting a second carbon fiber base plate, a rigid frame, and a polyimide film on the first carbon fiber base plate. The polyimide film acts as an isolation layer to prevent the carbon fiber from sticking to the mold during curing; it also reduces friction, protects the mold surface, and partially absorbs interfacial stress caused by temperature changes, reducing the risk of microcracks or delamination in the molded product due to thermal mismatch.

[0011] This invention, by filling a rigid frame with a honeycomb panel, can not only significantly reduce the weight of the mold, but also effectively distribute the load and prevent the mold from deforming due to pressure or temperature during the molding process. The combination of the rigid frame and the honeycomb panel can suppress local buckling and improve the mold's resistance to compression and bending.

[0012] The carbon fiber molding die with a honeycomb sandwich structure described in this utility model is used for autoclave molding and is used in conjunction with auxiliary materials such as vacuum bags, breathable felt, and release cloth. It is mainly used for molding high-precision aerospace components such as aircraft fuselage skin and wing panels.

[0013] Preferably, the thickness of the first carbon fiber base plate is 5 to 8 mm, for example, it can be 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7.5 mm or 8 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] The preferred thickness of the first carbon fiber base plate in this invention is 5-8 mm, which can control the dimensional deviations caused by expansion and contraction of the molding die during vacuum forming. When the thickness of the first carbon fiber base plate is too small, the bending stiffness is significantly reduced, making it prone to deformation under molding pressure, leading to decreased mold surface accuracy and reduced dimensional accuracy of the formed product; moreover, a smaller thickness of the first carbon fiber base plate will shorten the mold's service life. Conversely, a larger thickness of the first carbon fiber base plate will result in higher mold costs, delayed thermal response, and is detrimental to product forming.

[0015] Preferably, the thickness of the second carbon fiber base plate is 0.1 to 0.4 mm, for example, it can be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm or 0.4 mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, the thickness of the rigid frame is 8 to 13 mm, for example, it can be 8 mm, 9 mm, 10 mm, 11 mm, 12 mm or 13 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, the thickness of the honeycomb panel is 8 to 13 mm, for example, it can be 8 mm, 8.5 mm, 9.2 mm, 10.5 mm, 11.8 mm or 13 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, along the long side, the rigid frame comprises 2 to 4 parts, which are separated by connecting rods, for example, 2, 3 or 4 parts.

[0019] The carbon fiber molding die with a honeycomb sandwich structure described in this utility model can be configured into multiple parts according to actual needs, and products that meet the requirements can be prepared through processing and molding.

[0020] Preferably, when the rigid frame comprises four parts, the first part is symmetrical to the fourth part, and the second part is symmetrical to the third part.

[0021] Preferably, the area ratio of the first part, the second part, the third part, and the fourth part is (0.8~1.2):(0.7~2.4):(0.7~2.4):(0.8~1.2), for example, it can be 0.8:0.7:0.7:0.8, 0.9:1.0:1.2:1.0, 1.0:1.5:1.8:1.1, 1.1:2.0:2.2:1.0, 1.2:2.3:2.4:0.9, or 1.2:2.4:2.4:1.2, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] Preferably, the rigid frame has positioning holes on the connecting rods perpendicular to its long side. The positioning holes securely fix the rigid frame, ensuring that it does not shift position during processing and forming, thus guaranteeing the quality of the final molded product.

[0023] This invention does not specify the exact location of the positioning hole; it can be designed reasonably according to actual needs.

[0024] The carbon fiber molding die with a honeycomb sandwich structure described in this utility model is rectangular in shape. The long side refers to the side with the longer side of the carbon fiber molding die, and the other side perpendicular to the long side is the short side.

[0025] Preferably, the thickness of the polyimide film is 0.1 to 0.4 mm, for example, it can be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm or 0.4 mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] The method of using the carbon fiber molding die with a honeycomb sandwich structure described in this utility model includes:

[0027] Carbon fiber material is placed on the carbon fiber molding mold with a honeycomb sandwich structure to form a layup. Then, it is covered and sealed with auxiliary materials such as vacuum bags, breathable felt, and release cloth. The entire "mold + layup + vacuum bag system" is placed in an autoclave. The layup is compacted onto the surface of the rigid mold and cured by the combined action of the gas pressure inside the autoclave and the negative pressure under the vacuum bag.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] The carbon fiber molding die with a honeycomb sandwich structure provided by this utility model has a reasonable structural design and is easy to use. It significantly improves the overall dimensional stability of carbon fiber products, and the molded carbon fiber products have high dimensional accuracy, meeting the requirements of use. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view along the short side of the carbon fiber molding die with a honeycomb sandwich structure provided in Embodiment 1 of this utility model.

[0031] Figure 2 This is a schematic diagram of the structure of the unfilled honeycomb plate of the carbon fiber molding mold with a honeycomb sandwich structure provided in Embodiment 1 of this utility model.

[0032] Figure 3 This is a top view of the carbon fiber molding die with a honeycomb sandwich structure provided in Embodiment 1 of this utility model.

[0033] In the figure: 1-First carbon fiber base plate; 2-Second carbon fiber base plate; 3-Rigid frame; 4-Polyimide film; 5-Honeycomb panel; 6-First part; 7-Second part; 8-Third part; 9-Fourth part; 10-Positioning hole. Detailed Implementation

[0034] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims.

[0036] It should be understood that in the description of this utility model, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0037] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" 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 utility model based on the specific circumstances.

[0038] Example 1

[0039] This embodiment provides a carbon fiber molding die with a honeycomb sandwich structure, the cross-sectional view of which along the short side is shown below. Figure 1 As shown; a schematic diagram of the structure of the unfilled honeycomb panel is shown below. Figure 2 As shown; Top view as Figure 3 As shown.

[0040] The carbon fiber molding die with a honeycomb sandwich structure includes a first carbon fiber base plate 1, a second carbon fiber base plate 2, a rigid frame 3, and a polyimide film 4 arranged sequentially from bottom to top; the rigid frame 3 is filled with a honeycomb panel 5.

[0041] The thickness of the first carbon fiber base plate 1 is 6mm.

[0042] The thickness of the second carbon fiber base plate 2 is 0.2 mm.

[0043] The rigid frame 3 has a thickness of 10 mm.

[0044] The thickness of the honeycomb panel 5 is 10mm.

[0045] Along its long side, the rigid frame 3 comprises four parts, which are separated by connecting rods. The first part 6 is symmetrical to the fourth part 9, and the second part 7 is symmetrical to the third part 8.

[0046] The area ratios of Part 6, Part 7, Part 8, and Part 9 are 1:2:2:1.

[0047] The rigid frame 3 has a positioning hole 10 on the connecting rod perpendicular to the long side direction.

[0048] The polyimide film 4 has a thickness of 0.2 mm.

[0049] Example 2

[0050] This embodiment provides a carbon fiber molding die with a honeycomb sandwich structure. The carbon fiber molding die with a honeycomb sandwich structure includes a first carbon fiber base plate, a second carbon fiber base plate, a rigid frame, and a polyimide film arranged sequentially from bottom to top; the rigid frame is filled with a honeycomb plate.

[0051] The thickness of the first carbon fiber base plate is 5mm.

[0052] The thickness of the second carbon fiber base plate is 0.4 mm.

[0053] The rigid frame has a thickness of 13 mm.

[0054] The thickness of the honeycomb panel is 13mm.

[0055] Along its long side, the rigid frame comprises four parts, which are separated by connecting rods. The first part is symmetrical to the fourth part, and the second part is symmetrical to the third part.

[0056] The area ratios of the first, second, third, and fourth parts are 0.8:2.1:2.1:0.8, respectively.

[0057] The rigid frame has positioning holes on the connecting rods perpendicular to the long side direction.

[0058] The polyimide film has a thickness of 0.1 mm.

[0059] Example 3

[0060] This embodiment provides a carbon fiber molding die with a honeycomb sandwich structure. The carbon fiber molding die with a honeycomb sandwich structure includes a first carbon fiber base plate, a second carbon fiber base plate, a rigid frame, and a polyimide film arranged sequentially from bottom to top; the rigid frame is filled with a honeycomb plate.

[0061] The thickness of the first carbon fiber base plate is 8mm.

[0062] The thickness of the second carbon fiber base plate is 0.1 mm.

[0063] The rigid frame has a thickness of 8 mm.

[0064] The thickness of the honeycomb panel is 8mm.

[0065] Along its long side, the rigid frame comprises four parts, which are separated by connecting rods. The first part is symmetrical to the fourth part, and the second part is symmetrical to the third part.

[0066] The area ratios of the first, second, third, and fourth parts are 1.2:0.8:0.7:1.2, respectively.

[0067] The rigid frame has positioning holes on the connecting rods perpendicular to the long side direction.

[0068] The polyimide film has a thickness of 0.4 mm.

[0069] The carbon fiber molding die with honeycomb sandwich structure provided in Examples 1-3 has a reasonable structural design and is easy to use. The first carbon fiber base plate with a low coefficient of thermal expansion is used as the base to fix the molding die and prevent dimensional deviations caused by expansion and contraction during vacuum forming. It can effectively solve the shortcomings of traditional molds in precision control, significantly improve the overall dimensional stability of carbon fiber products, and produce carbon fiber products with high dimensional accuracy.

[0070] Example 4

[0071] This embodiment provides a carbon fiber molding die with a honeycomb sandwich structure. Except for the thickness of the first carbon fiber base plate being 3mm, the carbon fiber molding die with a honeycomb sandwich structure is the same as that in Embodiment 1.

[0072] In this embodiment, due to the small thickness of the first carbon fiber base plate, the bending stiffness is significantly reduced, making it prone to deformation under molding pressure. This leads to a decrease in the accuracy of the mold surface, a reduction in the dimensional accuracy of the product after molding, and a shortening of the mold's service life.

[0073] Example 5

[0074] This embodiment provides a carbon fiber molding die with a honeycomb sandwich structure. Except for the thickness of the first carbon fiber base plate being 10mm, the carbon fiber molding die with a honeycomb sandwich structure is the same as that in Embodiment 1.

[0075] In this embodiment, the large thickness of the first carbon fiber base plate leads to higher mold costs and delayed thermal response, which is not conducive to product molding.

[0076] Comparative Example 1

[0077] This comparative example provides a carbon fiber molding die with a honeycomb sandwich structure. Except for the absence of a first carbon fiber base plate, the carbon fiber molding die with a honeycomb sandwich structure is the same as that in Example 1.

[0078] Because this comparative example does not have a first carbon fiber base plate, the molding mold cannot be fixed well. During the vacuum forming process, the expansion and contraction will produce large dimensional deviations, resulting in a large dimensional deviation in the final molded product.

[0079] Comparative Example 2

[0080] This comparative example provides a carbon fiber molding die with a honeycomb sandwich structure. The carbon fiber molding die with a honeycomb sandwich structure is the same as that in Example 1, except that the honeycomb plate filled in the rigid frame is replaced with a rigid plate of the same thickness.

[0081] Because the rigid frame in this comparative example is filled with a rigid plate, the carbon fiber molding die will deform due to pressure or temperature during the molding process, which will affect the quality of the final product.

[0082] The applicant declares that the detailed structural features of this utility model are illustrated through the above embodiments, but this utility model is not limited to the above detailed structural features, that is, it does not mean that this utility model must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions of selected components, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this utility model.

[0083] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A carbon fiber molding die with a honeycomb sandwich structure, characterized in that, The carbon fiber molding die with a honeycomb sandwich structure includes a first carbon fiber base plate, a second carbon fiber base plate, a rigid frame, and a polyimide film arranged sequentially from bottom to top; the rigid frame is filled with a honeycomb panel.

2. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, The thickness of the first carbon fiber base plate is 5-8 mm.

3. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, The thickness of the second carbon fiber base plate is 0.1 to 0.4 mm.

4. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, The thickness of the rigid frame is 8–13 mm.

5. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, The thickness of the honeycomb panel is 8–13 mm.

6. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, Along its long side, the rigid frame comprises 2 to 4 parts, which are separated by connecting rods.

7. The carbon fiber molding die with a honeycomb sandwich structure according to claim 6, characterized in that, When the rigid frame comprises four parts, the first part is symmetrical to the fourth part, and the second part is symmetrical to the third part.

8. The carbon fiber molding die with a honeycomb sandwich structure according to claim 7, characterized in that, The area ratios of the first, second, third, and fourth parts are (0.8–1.2):(0.7–2.4):(0.7–2.4):(0.8–1.2), respectively.

9. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, The rigid frame has positioning holes on the connecting rods perpendicular to the long side direction.

10. The carbon fiber molding die with a honeycomb sandwich structure according to claim 1, characterized in that, The thickness of the polyimide film is 0.1 to 0.4 mm.

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