Integrated winding forming method of grid-type load-bearing cylinder metal structure and grid body

Abstract

This invention discloses a method for integrated winding forming of a mesh-type load-bearing cylinder metal structure and a mesh body, comprising: fabricating a winding mold; fitting a metal structure onto the outer surface of the bottom of the winding mold; winding impregnated fibers onto the outer surface of the winding mold and the outer surface of the metal structure to obtain an integrated blank of the composite material mesh structure and the metal structure; placing the integrated blank and the winding mold as a whole into an autoclave for curing to obtain a cured whole; removing the winding mold from the cured whole to obtain the cured integrated blank of the composite material mesh structure and the metal structure; and machining the cured integrated blank of the composite material mesh structure and the metal structure to obtain the integrated product of the composite material mesh structure and the metal structure. This invention achieves a reliable connection between the composite material mesh body and the metal parts, ensuring interface accuracy and improving processing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber reinforced resin matrix composite material structure manufacturing technology, and particularly relates to a method for integrally winding and forming a mesh-type load-bearing cylinder metal structure and the mesh body. Background Technology

[0002] To meet the basic configuration and force transmission path requirements of the spacecraft, a main load-bearing cylindrical structure was equipped with an outer envelope of Φ1200 (inner diameter) × 1620 (height) × 15 (wall thickness) mm, satisfying the requirements for lightweight and efficient manufacturing. Traditional metal structures have long development cycles and low yield rates, making them unsuitable for lightweight requirements. Meanwhile, conventional composite material load-bearing structures such as skin-reinforced structures, honeycomb sandwich structures, and truss structures cannot meet the needs of efficient manufacturing.

[0003] The composite mesh structure is a hollow structure based on unidirectional composite material ribs, featuring lightweight, high damage resistance, high directional load-bearing capacity, and easy automation of repetitive mesh patterns. External mounting surfaces and interfaces are still achieved using metal structures, typically employing a combination of adhesive bonding and screwing to fix the composite mesh body to the metal parts. According to this approach, the composite mesh body and metal parts are formed separately, then bonded together using adhesive bonding and screwing, resulting in a slightly longer overall processing cycle. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for integrated winding forming of a mesh-type load-bearing cylinder metal structure and a mesh body, which realizes a reliable connection between the composite material mesh body and the metal parts, ensuring interface accuracy and improving processing efficiency.

[0005] The objective of this invention is achieved through the following technical solution: a method for integrally winding a mesh-type load-bearing cylinder metal structure and a mesh body, comprising: fabricating a winding mold; fitting a metal structure onto the outer surface of the bottom of the winding mold; winding impregnated fibers onto the outer surface of the winding mold and the outer surface of the metal structure to obtain an integral blank of the composite material mesh structure and the metal structure; placing the integral blank of the composite material mesh structure and the metal structure and the winding mold as a whole into an autoclave for curing to obtain a cured whole; removing the winding mold from the cured whole to obtain the cured integral blank of the composite material mesh structure and the metal structure; and machining the cured integral blank of the composite material mesh structure and the metal structure to obtain the integrated product of the composite material mesh structure and the metal structure.

[0006] In the above-mentioned method for the integrated winding forming of a mesh-type load-bearing cylinder metal structure and a mesh body, the winding mold includes a core mold and a forming soft mold; wherein, the core mold is cylindrical, and the forming soft mold is disposed on the outer surface of the core mold.

[0007] In the above-mentioned method for the integrated winding forming of the mesh-type load-bearing cylinder metal structure and the mesh body, the inner wall of the core mold is provided with an annular plate and longitudinal ribs; wherein, the annular plate and the longitudinal ribs are connected in a mesh pattern.

[0008] In the above-mentioned method for integrally winding and forming the mesh-type load-bearing cylinder metal structure and the mesh body, the forming soft mold is silicone rubber.

[0009] In the above-mentioned method for the integrated winding forming of the metal structure and the mesh body of the grid-type load-bearing cylinder, between the process of winding the impregnated fiber on the outer surface of the winding mold and the outer surface of the metal structure to obtain the integrated blank of the composite material grid structure and the metal structure, and placing the integrated blank of the composite material grid structure and the metal structure and the winding mold as a whole into a hot autoclave for curing to obtain the cured whole, the method further includes: pre-pressing the integrated blank of the composite material grid structure and the metal structure and the winding mold as a whole at room temperature.

[0010] In the above-mentioned method for the integrated winding forming of the metal structure and the mesh body of the grid-type load-bearing cylinder, the pre-pressing of the integrated blank of the composite material grid structure and the metal structure and the winding mold at room temperature as a whole includes: placing the integrated blank of the composite material grid structure and the metal structure and the winding mold as a whole into a vacuum bag film, evacuating to 0.01MPa, letting it stand at room temperature, and maintaining the pressure for 10h-12h.

[0011] In the above-mentioned method for the integrated winding forming of the mesh-type load-bearing cylinder metal structure and the mesh body, impregnated fibers are wound onto the outer surface of the winding mold and the outer surface of the metal structure using a carbon fiber / epoxy resin wet method to obtain an integrated blank of composite material mesh structure and metal structure.

[0012] In the above-mentioned method for integrally winding the metal structure of the grid-type load-bearing cylinder with the grid body, the curing process includes: raising the temperature from 25°C to 100°C-105°C within 30 minutes; maintaining the temperature at 100°C-105°C for 30 minutes; raising the temperature from 100°C-105°C to 140°C within 30 minutes; and maintaining the temperature at 140°C for 3 hours before cooling down to room temperature.

[0013] In the above-mentioned method for the integrated winding forming of the mesh-type load-bearing cylinder metal structure and the mesh body, the forming soft mold is made by pouring silicone rubber into a flat mold and then curing it at room temperature, and then winding it around the outer surface of the core mold.

[0014] In the above-mentioned method for integrating the mesh-type load-bearing tube metal structure with the mesh body through winding, the roundness of the integrated composite mesh structure and metal structure product is:

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention proposes a solution to solve the problem of integrated winding molding of the mesh body and the metal parts by first processing the metal part blank, then winding it in an integrated manner, and finally combining the processing. It combines various methods such as reserving and removing the process allowance of the metal parts, accommodating the ribs of the blank, pre-pressing at room temperature, and adapting the curing parameters to achieve a reliable connection between the composite material mesh body and the metal parts, which not only ensures the interface accuracy but also improves the processing efficiency. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0018] Figure 1 This is a schematic diagram of the integrated molded mesh load-bearing cylinder structure provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the metal structure provided in an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the state of a metal structural part provided in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the winding mold provided in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the end oblique winding path provided in an embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the end circumferential winding path provided in an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the product curing system provided in an embodiment of the present invention. Detailed Implementation

[0025] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] This embodiment provides a method for integrally winding and forming a mesh-type load-bearing cylinder metal structure and a mesh body, the method including the following steps:

[0027] Make a winding mold;

[0028] The metal structure is fitted onto the outer surface of the bottom of the winding mold;

[0029] Impregnated fibers are wet-wound onto the outer surface of a winding mold and the outer surface of a metal structure using a carbon fiber / epoxy resin method to obtain an integrated blank of composite material mesh structure and metal structure.

[0030] The composite material mesh structure and metal structure integrated blank and winding mold are placed in an autoclave for curing to obtain the cured whole;

[0031] After the curing mold is removed, the integrated blank of the composite material mesh structure and the metal structure is obtained.

[0032] The integrated composite mesh structure and metal structure product is obtained by machining the solidified composite mesh structure and metal structure integrated blank.

[0033] The winding mold includes a core mold and a forming soft mold; wherein the core mold is cylindrical, and the forming soft mold is disposed on the outer surface of the core mold. The inner wall of the core mold is provided with annular plates and longitudinal ribs; wherein the annular plates and the longitudinal ribs are connected in a mesh pattern.

[0034] The process of obtaining an integrated composite mesh structure and metal structure blank by winding impregnated fibers onto the outer surface of a winding mold and the outer surface of a metal structure, and then placing the integrated composite mesh structure and metal structure blank and the winding mold as a whole into an autoclave for curing to obtain a cured whole, also includes:

[0035] The composite mesh structure and metal structure integrated blank and winding mold are pre-pressed at room temperature as a whole.

[0036] Pre-pressing the composite mesh structure and metal structure integrated blank and winding mold at room temperature as a whole includes: placing the composite mesh structure and metal structure integrated blank and winding mold as a whole into a vacuum bag, evacuating to 0.01MPa, letting it stand at room temperature, and maintaining the pressure for 10h-12h.

[0037] The curing process includes: raising the temperature from 25°C to 100°C-105°C within 30 minutes; holding the temperature at 100°C-105°C for 30 minutes; raising the temperature from 100°C-105°C to 140°C within 30 minutes; holding the temperature at 140°C for 3 hours and then cooling down to room temperature.

[0038] The metal structural components have pre-reserved manufacturing allowances in their part state, including external connection holes and connection surfaces. The metal structural components are generally circular frames and need to be assembled together with the winding mold.

[0039] The main material of the winding mold should be a raw material similar to that of the metal part, or a material with a similar coefficient of expansion, to ensure that the expansion of the two is matched during curing and heating, so as not to produce large curing deformation, which would cause the allowance of the metal part to fail to cover the final size, or even damage the metal part itself.

[0040] After the winding mold (including the annular frame) is assembled in place, a CNC winding machine is used to wind the composite material mesh body, winding the frame and the composite material mesh body into one piece.

[0041] After winding is completed, a vacuum compaction process is performed at room temperature. The process is as follows: Vacuum bag film, sealing strip and other auxiliary materials are wrapped in sequence to seal the blank into a vacuum system. After vacuuming to 0.01MPa, it is left to stand at room temperature and pressure is maintained for 12 hours. Then the vacuum is stopped and the auxiliary materials are removed.

[0042] The product blank is cured using an autoclave. A perforated release film, felt, vacuum bag film, and sealing strips are sequentially wrapped to encapsulate the blank and the winding mold assembly. The assembly is then placed in the autoclave, and cured under vacuum, heat, and pressure. The curing process is optimized by appropriately reducing the external curing pressure and holding temperature to further minimize curing deformation of the metal parts.

[0043] After demolding, the product blank is machined: the annular frame and its surrounding mesh body are machined to obtain the connection hole between the annular frame and the mesh body, the external mounting surface and the mounting hole.

[0044] Use standard parts such as screws, washers, and nuts of appropriate specifications to screw the circular frame and the composite material mesh body together to improve their connection strength.

[0045] Research and development such as Figure 1 The mesh-type load-bearing cylinder shown was first designed with a winding mold based on the product's shape. The mold has an aluminum core mold on the inside and a soft molding mold on the outside, achieving the purpose of integral winding, curing, and demolding of the composite material mesh structure and the metal structure. The main body is formed by hot pressing.

[0046] The core mold features a thin-walled design with an added reinforcing ring plate and longitudinal ribs on the inner side to ensure sufficient rigidity and reduce deformation when laid horizontally, thus helping to maintain the product's shape. A step is provided on one side of the core mold to facilitate the positioning and installation of the metal structure.

[0047] The molding soft mold is made by pouring silicone rubber into a flat mold, curing it at room temperature, and then winding it around the outer surface of the core mold. The soft mold has narrow slits on its surface, which serve as channels for the formation of the ribs.

[0048] Metal structure ( Figure 2 (As shown) is also an aluminum product. It is first machined to the required specifications, but with a machining allowance (as shown). Figure 3 As shown), and installed on the winding mold ( Figure 4 (As shown) at the corresponding positions. Four to eight Φ2.5mm small holes can be drilled in advance at the theoretical positions of the metal structure and the external mounting holes to facilitate the fastening of the metal structure and the core mold with M2 screws.

[0049] The fiber / epoxy resin wet winding method is adopted, and the ribs are wound in the narrow gap between the winding mold and the mesh load-bearing cylinder metal structure. The fibers are repeatedly stacked and impregnated until the product thickness requirements are met.

[0050] End winding path as follows Figure 5 , Figure 6 As shown, the end grid adopts a hard mold design, acting as a winding and returning yarn structure. The oblique layer is wound first, followed by the circumferential layer, ensuring fiber continuity as much as possible. The wall thickness is increased uniformly by adjusting the width of the end frame. When winding the circumferential layer, there are areas within a single layer that are not covered by yarn. Offsetting the transition area between the oblique and circumferential layers ensures that these uncovered areas are evenly distributed within the end frame of the grid body.

[0051] To ensure the blank adheres to the mold and reduce air mixing between layers, a room temperature vacuum compaction process is carried out after winding.

[0052] The product and mold assembly was cured in an autoclave. A vacuum was applied before heating, and the maximum temperature was 140℃ for 3 hours, with a maximum external pressure of 0.2 MPa. Compared to conventional conditions, both the maximum temperature (160℃) and maximum external pressure (0.4 MPa) were lower. After the heat treatment, the vacuum was immediately stopped, the external pressure was released, and then the temperature was lowered. The curing regime curve is shown below. Figure 7 As shown.

[0053] When the mold temperature drops to 40℃, remove the assembly from the curing platform and remove most of the soft mold and one end of the mandrel (excluding the metal structure end). Rotate the assembly 90° and stand it upright in a suitable position (with the metal structure end facing down). Remove the remaining soft mold and use an overhead crane and slings to remove the product along with the metal structure from the core mold. Remove any excess adhesive from the product surface.

[0054] The product blank is machined to ensure that the external mounting surfaces and holes of the metal structure, as well as the connection holes with the grid body, meet the requirements. Alternatively, a special drilling jig can be used to drill the external mounting holes of the metal structure, ensuring that the position of these holes is consistent with the condition of the relevant components.

[0055] Finally, use standard parts such as screws, washers, and nuts of appropriate specifications to bolt the metal structure to the composite material mesh body, and apply a reasonable tightening torque. Alternatively, custom-made washers can be used to improve the bolting strength.

[0056] The resulting product's dimensions meet the design requirements, and the roundness of the composite material mesh body is [value missing]. The flatness of the external mounting surface of the metal structure is 0.3mm, and the position of the mounting holes is...

[0057] This embodiment proposes a solution to address the problem of integrated winding molding of the mesh body and metal parts by first processing the metal part blank, then integrally winding, and finally combining the processing. It combines various methods such as reserving and removing the process allowance of the metal parts, accommodating the rib characteristics of the blank, room temperature pre-pressing, and adaptive adjustment of curing parameters to achieve a reliable connection between the composite material mesh body and the metal parts, which not only ensures the interface accuracy but also improves the processing efficiency.

[0058] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for integrally winding and forming a mesh-type load-bearing cylinder metal structure and a mesh body, characterized in that... include: Make a winding mold; The metal structure is fitted onto the outer surface of the bottom of the winding mold; Impregnated fibers are wet-wound onto the outer surface of a winding mold and the outer surface of a metal structure using a carbon fiber / epoxy resin method to obtain an integrated blank of composite material mesh structure and metal structure; wherein, the end mesh adopts a hard mold design, which acts as a winding return structure; first the oblique layer is wound, and then the circumferential layer is wound to ensure fiber continuity, and the wall thickness is uniformly increased by increasing or decreasing the width of the end frame; when winding the circumferential layer, there are areas not covered by yarn in a single layer, and the areas not covered by yarn are uniformly distributed within the end frame of the mesh body by offsetting the transition area between the oblique layer and the circumferential layer; The composite material mesh structure and metal structure integrated blank and winding mold are placed in an autoclave for curing to obtain the cured whole; After the curing mold is removed, the integral blank of the composite material mesh structure and metal structure is obtained by removing the winding mold. The integrated composite mesh structure and metal structure blank after curing and molding are machined to obtain the integrated composite mesh structure and metal structure product. The winding mold includes a core mold and a forming soft mold; wherein, the core mold is cylindrical, and the forming soft mold is disposed on the outer surface of the core mold; The inner wall of the core mold is provided with an annular plate and longitudinal ribs; wherein the annular plate and the longitudinal ribs are connected in a mesh pattern. The molding soft mold is made of silicone rubber; The process of obtaining an integrated composite mesh structure and metal structure blank by winding impregnated fibers onto the outer surface of a winding mold and the outer surface of a metal structure, and then placing the integrated composite mesh structure and metal structure blank and the winding mold as a whole into an autoclave for curing to obtain a cured whole, also includes: The composite mesh structure and metal structure integrated blank and winding mold are pre-compressed at room temperature as a whole; this room temperature pre-compressing includes: The composite material mesh structure and metal structure integrated blank and winding mold are placed as a whole into a vacuum bag film, vacuumed to 0.01MPa, left to stand at room temperature, and then kept under pressure for 10-12 hours.

2. The method for integrated winding forming of the mesh-type load-bearing cylinder metal structure and the mesh body according to claim 1, characterized in that: Curing and molding include: The temperature can be raised from 25℃ to 100℃-105℃ within 30 minutes; Maintain the temperature at 100℃-105℃ for 30 minutes; The temperature can be raised from 100℃-105℃ to 140℃ within 30 minutes; After maintaining the temperature at 140℃ for 3 hours, the temperature was lowered to room temperature.

3. The method for integrated winding forming of the mesh-type load-bearing cylinder metal structure and the mesh body according to claim 1, characterized in that: The molding soft mold is made by pouring silicone rubber into a flat mold and then curing it at room temperature, and then winding it around the outer surface of the core mold.

4. The method for integrated winding forming of the mesh-type load-bearing cylinder metal structure and the mesh body according to claim 1, characterized in that: The roundness of the integrated composite mesh structure and metal structure product is 3mm.

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