A method of autoclave molding of a variable curvature variable cross-section orthogrid composite member

Abstract

The application discloses a kind of variable curvature variable cross-section orthogonal grid composite component autoclave forming method, the digital model of variable curvature variable cross-section orthogonal grid composite component to be formed is divided into through grid assembly, non-through grid assembly and reinforcing layer assembly;And design corresponding mold laying tooling, mold laying is carried out, then respectively pre-compaction is carried out again assembly co-solidification.The application is formed by using "soft mold+expansion silica gel" auxiliary autoclave forming, adaptive variable curvature variable cross-section orthogonal grid composite component, and the forming mode avoids the phenomena such as fiber accumulation, fiber wrinkle, fiber fracture in grid intersection area, while reducing overpressure or insufficient pressure phenomenon, improve component strength;And the forming mode manufacturing process is simple, combination between different molds is convenient, easy to demould, greatly improve production efficiency, with good application value and popularization prospect.

Description

Technical Field

[0001] This invention relates to an autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section. Background Technology

[0002] Orthogonal mesh composite material components are a special type of composite material component, such as... Figure 1 As shown, it consists of fiber meshes arranged in two or more directions. A key feature of this type of component is the right-angled relationship between the fiber meshes, forming an orthogonal mesh structure. Orthogonal mesh composite components typically consist of two types of fibers: longitudinal fibers and transverse fibers. Longitudinal fibers are arranged along the length of the component, providing high strength and rigidity. Transverse fibers are arranged at right angles to the longitudinal fibers, increasing the component's transverse strength and rigidity. Variable curvature and variable cross-section orthogonal mesh composite components are a type of orthogonal mesh composite component with dynamic deformation capabilities. Compared to ordinary orthogonal mesh composite components, they have the ability to actively or passively adjust their shape and cross-section. This type of component typically consists of two or more layers of orthogonal meshes, where the fiber orientation of each layer can be controlled as needed. By adjusting the fiber orientation of different layers, changes in the curvature and cross-sectional shape of the component can be achieved. For example, when force or strain is applied, the fiber orientation can be changed, resulting in bending or torsion of the component.

[0003] Currently, the fabrication processes for orthogonal mesh composite material components with variable curvature and cross-section include mixing processes, die expansion processes, and pultrusion-interlocking molding processes. However, these methods all have certain drawbacks, which are summarized as follows:

[0004] 1) These forming processes are only suitable for manufacturing simple components with uniform curvature and small thickness variations, and cannot be applied to forming orthogonal grid structures with variable curvature and cross-section.

[0005] 2) These molding processes are prone to fiber accumulation, fiber wrinkling and fiber breakage in the grid intersection area. They are also prone to over-pressure or under-pressure, resulting in the strength of the molded component failing to meet the design requirements.

[0006] 3) These molding processes often ensure that the inner cavity surface of the component cannot simultaneously maintain the shape of the outer surface of the part, thus failing to meet the requirements of different working conditions and limiting their application range;

[0007] 4) The molding process requires a lot of tooling, and the tooling fit relationship is highly demanding, resulting in wasted tooling and high manufacturing costs; in addition, the manufacturing process is complex, the operation is difficult, and there are difficulties in demolding.

[0008] Therefore, how to prepare high-strength, well-formed internal and external surfaces, orthogonal mesh composite material components with variable curvature and cross-section using a simple process remains an urgent problem to be solved. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a method for autoclaving orthogonal mesh composite material components with variable curvature and cross-section. By employing a "soft mold + expanding silicone" assisted autoclaving process, the manufacturing of the variable curvature and cross-section orthogonal mesh composite material is completed. This molding process offers advantages such as high reliability, repeatability, easy demolding, and low cost, not only solving the aforementioned problems but also saving manufacturing costs. The specific technical solution is as follows:

[0010] A method for autoclaving a variable curvature, variable cross-section orthogonal mesh composite material component includes the following steps:

[0011] 1) Mold design: Based on the digital model of the orthogonal mesh composite material component with variable curvature and variable cross-section to be formed, its structure is divided into through mesh components, non-through mesh components, intermediate reinforcing layer components and peripheral baffle components.

[0012] 2) Laying fixture design: Based on the structural form of each component, design and prepare the corresponding mold laying fixture, and determine the layup thickness and layup structure of each component.

[0013] 3) Partitioning and Laying: Based on the partitioning design, the prepreg used to prepare orthogonal mesh composite material components with variable curvature and cross-section is divided accordingly; and each component prepreg is laid on the corresponding partitioning and laying fixture according to the requirements.

[0014] 4) Pre-molding: After the prepreg of each component is laid out, the prepreg of each component along with its respective prepreg laying fixture is sent into the autoclave for hot compaction to obtain through components, non-through components, reinforced components and peripheral baffle components.

[0015] 5) Co-curing: After the pre-forming by mold splitting, the through components, non-through components, reinforcing components and peripheral baffle components are assembled by mold closing using positioning plates as required, and carbon twisted wire is filled at the R-corners of each grid connection. Then, it is sent into a hot autoclave for hot-press co-curing.

[0016] 6) Demolding and molding: After co-curing, the installation fixtures of each component are removed to obtain a variable curvature and variable cross-section orthogonal grid composite material component.

[0017] In the aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section, step 2) involves designing corresponding parting and laying fixtures based on the structural morphology of each component, wherein:

[0018] The mold-laying fixture for the through-type mesh component consists of a flexible core mold and a hot-pressing fixture.

[0019] The parting and laying fixture for non-through mesh components is a metal male mold with a silicone layer;

[0020] The mold-separation and installation fixture for the intermediate reinforcing layer component is a metal cavity mold with installation grooves;

[0021] The mold-laying fixture for the perimeter baffle assembly includes four metal plate molds that can be closed into a frame.

[0022] The aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section, wherein the flexible mandrel is a silicone rubber airbag with a carbon fiber reinforcement layer sandwiched inside, comprising a central shaped part and two clamping and positioning parts at both ends; the shaped part is designed and manufactured according to the cavity surface of the through-grid of the orthogonal mesh composite material component with variable curvature and cross-section; the clamping and positioning parts include a clamping support section and a clamping sleeve section, wherein the cross-sectional area of ​​the clamping support section is larger than the cross-sectional area of ​​the clamping sleeve section.

[0023] In the aforementioned autoclave molding method for a variable curvature and variable cross-section orthogonal mesh composite material component, the metal male mold with a silicone layer has a silicone layer prepared by a specially designed injection tool. This injection tool has a closed structure with a silicone molding gap inside that matches the non-through-grid inner surface of the variable curvature and variable cross-section orthogonal mesh composite material component, and a filling port at its top. The adhesive used to prepare the silicone layer is injected into the silicone molding gap through the filling port and cured to obtain the desired silicone layer. The silicone layer has a thickness of 12–15 mm, and its expansion at the autoclaving temperature is 0.6–0.8 mm. The metal male mold is provided with an assembly latch for mold closing, and this assembly latch is located at the end furthest from the silicone layer.

[0024] In the aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and variable cross-section, the shape of the metal cavity mold with the paving groove is consistent with the shape of the divided intermediate reinforcing layer, and the depth is consistent with the thickness of the divided intermediate reinforcing layer.

[0025] The aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section, wherein the four metal plate molds include:

[0026] The first template has connecting holes on both ends;

[0027] Two second templates, one end of which has a bolt through hole that matches the connection hole of the first template, and the other end of which is turned outward into an L-shape as a positioning connection part;

[0028] A third template has positioning connection areas at both ends that match the positioning connection parts of the second template, and a prepreg laying platform in the middle.

[0029] In the aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section, step 3) involves mold splitting and laying:

[0030] The prepreg of the through-grid assembly is laid on the surface area of ​​the flexible core mold, and the hot-pressed metal tooling is installed on the outer surface of the prepreg.

[0031] After the non-through mesh component prepreg is laid on a metal male mold with a silicone layer, it is directly encapsulated and hot-pressed.

[0032] The prepreg of the intermediate reinforcing layer component is laid in the laying groove of the metal cavity mold;

[0033] The prepreg of the perimeter baffle assembly is laid on the corresponding four metal plate molds according to its position.

[0034] The aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and variable cross-section includes positioning plates comprising single-row positioning plates and integral positioning plates.

[0035] The single-row positioning plate is a plate-shaped body with a row of several snap-fit ​​sleeves that match the snap-fit ​​positioning part of the soft core mold; the size of the snap-fit ​​sleeve is smaller than the cross-sectional dimension of the snap-fit ​​support section, and can fit exactly on the snap-fit ​​sleeve section to position and assemble multiple through components into a row of assembly units.

[0036] The overall positioning plate is a polygonal frame that assembles multiple assembly units and non-through components into a whole.

[0037] The aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section involves the following mold assembly process:

[0038] 5-1) First, use single-row card plates to sort the components by column and clamp them onto the clamping sleeves at both ends of the flexible core mold at the corresponding positions on each single-row card plate. Combine the components to obtain a series of assembled units.

[0039] 5-2) Fill the gaps in each column of assembly units with carbon twisted wire to prepare for mold closing;

[0040] 5-3) The overall positioning plate is clamped on the clamping sleeve section on the outside of the single-row plate, and the assembled individual units and non-through components after being filled with carbon twisted wire are assembled into a whole according to the design position.

[0041] 5-4) While assembling the mold, remove the pre-formed reinforcing components from their mounting molds and clamp them one by one between the columns of the assembled unit and the non-through components.

[0042] 5-5) The pre-formed peripheral baffle assembly is placed around the perimeter of the through-part and non-through-part components after the mold is closed, according to the designed position, and the four metal plate molds are locked together with bolts.

[0043] 5-6) After the mold is closed, fill the R-corners of each mesh connection with carbon twisted wire to prepare for hot pressing and co-curing in an autoclave.

[0044] The aforementioned autoclave molding method for orthogonal mesh composite material components with variable curvature and cross-section, wherein the parameters for co-curing in the autoclave are: temperature 180±6℃, curing pressure 0.55~0.65Mpa, and holding time 150~220min.

[0045] The beneficial effects of this invention are as follows:

[0046] 1) The molding process of this invention adopts the "soft mold + expanding silicone" assisted autoclave molding method, which is suitable for molding orthogonal grid composite material components with variable curvature and cross section. This molding method avoids fiber accumulation, fiber wrinkles, fiber breakage and other phenomena in the grid intersection area, while reducing the occurrence of overpressure or insufficient pressure and improving the strength of the component.

[0047] 2) The molding process of this invention adopts "soft mold + expanding silicone" assisted autoclave molding, which can not only ensure the inner cavity surface of the component, but also maintain the outer surface shape, which can meet the requirements of different working conditions and has a wide range of applications; in addition, the manufacturing process of this molding method is simple, the combination of different molds is convenient, the demolding is easy, and the disassembly and assembly are convenient.

[0048] 3) The molding process of this invention cleverly divides the orthogonal grid component into a through grid component, a non-through grid component, an intermediate reinforcing layer component, and a peripheral baffle component; and by cleverly setting the laying fixtures of each component, and using single-row clamping plates and integral clamping plates for assembly, the orthogonal grid composite material component with variable curvature and variable cross-section is successfully and perfectly molded, effectively maintaining the shape of the inner cavity and outer surface of the component at the same time, and can be adapted to different working conditions, with a wide range of applications.

[0049] 4) The tooling required for the molding process of this invention is simple, the tooling fit relationship is clear, it is easy to operate, and it can be reused after demolding, ensuring the uniformity of component quality in different batches, greatly improving production efficiency, and has good application value and promotion prospects. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of the orthogonal mesh composite material component with variable curvature and variable cross-section according to the present invention;

[0051] Figure 2 This is a schematic diagram of the digital model division of the orthogonal mesh composite material component with variable curvature and variable cross-section according to the present invention;

[0052] Figure 3 A schematic diagram of the flexible core mold for the parting tooling of the through-type mesh component of the present invention;

[0053] Figure 4 A schematic diagram of the metal hot-pressing fixture structure for the through-type mesh component of the present invention;

[0054] Figure 5 A schematic diagram of a metal male mold structure with a silicone layer for the non-through mesh component laying and parting tooling of the present invention.

[0055] Figure 6 This is a schematic diagram of the injection tooling structure for silicone layer molding according to the present invention;

[0056] Figure 7 A schematic diagram of the metal cavity mold structure of the interlayer reinforcement component laying and parting tooling of the present invention;

[0057] Figure 8 A schematic diagram of the four metal plate mold structures of the perimeter baffle assembly laying and parting tooling of the present invention;

[0058] Figure 9 This is a schematic diagram of the assembly unit structure formed by assembling the through component using a single-row positioning card plate according to the present invention;

[0059] Figure 10 This is a schematic diagram of a series of assembly units formed by assembling a single row of positioning plates according to the present invention;

[0060] Figure 11 This is a schematic diagram of the non-through-type component assembly using an integral positioning plate according to the present invention;

[0061] Figure 12 This is a physical image of the orthogonal mesh composite material component with variable curvature and variable cross-section after molding according to the present invention. Detailed Implementation

[0062] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are merely preferred embodiments of the present invention, and not all embodiments, nor are they intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications or equivalent variations based on the disclosed technical content. However, any simple modifications, equivalent variations, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

[0063] Example 1

[0064] This embodiment describes a method for autoclaving a variable curvature, variable cross-section orthogonal mesh composite material component, which specifically includes the following steps:

[0065] 1) Mold design: such as Figure 2 As shown, to facilitate the pre-forming of the intermediate mesh structure, based on the digital model of the variable curvature and variable cross-section orthogonal mesh composite material component to be formed, all the meshes are separated into structures that can be laid individually, which are divided into through mesh components and non-through mesh components. Since the mesh structure is arranged orthogonally in both directions, in order to ensure its longitudinal strength, a reinforcing layer is also provided between the longitudinal mesh structures. This part is also separated from the digital model for pre-forming. In addition, to facilitate laying and to determine the wall thickness of each mesh after mold closing, the outermost mesh is separated into a peripheral baffle assembly.

[0066] 2) Laying fixture design: Based on the structural form of each component, design and prepare the corresponding mold-separating laying fixture, and determine the layup thickness and layup structure of each component. Among them:

[0067] The mold-laying fixture for the through-type mesh component consists of a flexible core mold and a hot-pressing fixture. The flexible core mold is a silicone rubber airbag with an internal carbon fiber reinforcement layer. Figure 3 As shown, it includes a central profile and two end mounting and positioning sections. The profile is designed and manufactured based on the cavity profile of a through-grid orthogonal mesh composite material component with variable curvature and cross-section. The mounting and positioning section includes a mounting support section and a mounting sleeve section, wherein the cross-sectional area of ​​the mounting support section is larger than that of the mounting sleeve section. In this embodiment, both the mounting support section and the mounting sleeve section of the mounting and positioning section are designed with a cylindrical cross-section that matches the cross-sectional shape of the through-grid. In other embodiments, they can be designed as circular or other shapes. From the perspective of ease of preparation and assembly, a square cylindrical design is the simplest and most practical. Furthermore, the height of the cylindrical mounting sleeve section is greater than the sum of the thicknesses of the single-row positioning plate and the overall positioning plate.

[0068] In this embodiment, the hot compaction fixture for the through-type mesh component is a four-lobed design, such as... Figure 4 As shown, specifically, two sub-mold bodies in the four-lobed hot-pressing fixture are symmetrically designed with the centerline of the curved surface of the through-mesh component as the other two sub-mold bodies; and each of the four sub-mold bodies has an assembly connection handle extending along the symmetrical centerline; the joints of the four sub-mold bodies at the other two end faces of the through-mesh component are designed with a mating interface consistent with the curvature of the curved surface, and the mating position is located at the centerline of the end face. In use, the through-mesh component prepreg is laid on the surface area of ​​the flexible core mold, and then the hot-pressing metal fixture is installed on the outer surface of the prepreg for hot pressing.

[0069] The parting and laying fixture for the non-through mesh component is a metal male mold with a silicone layer, such as... Figure 5As shown, the silicone layer of the metal male mold is prepared using a specially designed injection molding tool. The metal male mold has a mold-closing latch section at the end furthest from the silicone layer, facilitating the assembly of the overall positioning clamping plate during mold closing. This latch section is shaped like a rectangular tube formed by extending the port of a non-through-type mesh component, facilitating the positioning and assembly of the overall positioning clamping plate. The silicone layer molding injection molding tool has a closed structure, such as... Figure 6 As shown, the injection fixture has a silicone molding gap inside that matches the non-through mesh inner surface of the orthogonal mesh composite material component with variable curvature and cross-section. A filling port is located at the top. The adhesive used to prepare the silicone layer is poured into the silicone molding gap through the filling port and cured to obtain the desired silicone layer. In this embodiment, the silicone layer thickness is 12–15 mm, and its expansion at the hot-pressing co-curing temperature is 0.6–0.8 mm.

[0070] The mold-laying fixture for the intermediate reinforcing layer assembly is a metal cavity mold with laying grooves, such as... Figure 7 As shown, the shape of the metal cavity mold paving groove is consistent with the shape of the divided intermediate reinforcing layer, and its depth is consistent with the thickness of the divided intermediate reinforcing layer. After the prepreg of the reinforcing layer is paved in the paving groove and pre-pressed in the autoclave, it is demolded and then clamped between the longitudinal columns when the whole mold is closed.

[0071] The mold-laying fixture for the perimeter baffle assembly includes four metal plate molds capable of being closed into a frame, such as... Figure 8 As shown, it includes a first template, two second templates, and a third template. The first template has connecting holes on both ends, and the two second templates have bolt through holes on one side that match the connecting holes of the first template for mold assembly. The other end of each second template is turned outward as a positioning connection part, making the second template L-shaped for mold assembly with the third template. The third template has positioning connection areas at both ends that match the positioning connection parts of the second templates, with the middle part protruding upward to form a prepreg laying platform for easy laying and mold assembly.

[0072] 3) Partitioning and Laying: Based on the partitioning design, the prepreg used to prepare orthogonal mesh composite material components with varying curvature and cross-section is divided accordingly; and each component's prepreg is laid onto the corresponding partitioning and laying fixture according to requirements; wherein:

[0073] The prepreg of the through-type mesh component is laid on the surface area of ​​the flexible mandrel, and the hot-pressed metal tooling is attached to the outer surface of the prepreg, such as... Figure 4 As shown;

[0074] After the non-through-mesh component prepreg is laid on a metal male mold with a silicone layer, it is directly encapsulated and hot-pressed, such as... Figure 5 As shown;

[0075] The prepreg of the intermediate reinforcing layer component is laid in the laying groove of the metal cavity mold, such as... Figure 7 As shown;

[0076] The prepreg for the perimeter baffle assembly is laid on the corresponding four metal plates according to its location, such as... Figure 8 As shown.

[0077] 4) Pre-molding: After the prepreg of each component is laid out, the prepreg of each component along with its respective prepreg laying fixture is sent into the autoclave for hot compaction to obtain through components, non-through components, reinforced components and peripheral baffle components.

[0078] 5) Co-curing: After pre-forming by mold splitting, the through-hole components, non-through-hole components, reinforcing components, and peripheral baffle components are assembled using positioning clamps as required. Carbon twisted wire is filled at the R-corners of each mesh connection, and then the assembly is placed in an autoclave for hot-press co-curing. The mold assembly process is as follows:

[0079] 5-1) First, using single-row clamping plates, the through-type components are clamped onto the clamping sleeves at both ends of the flexible core mold at their corresponding positions on the corresponding positions of each single-row clamping plate. The through-type components are then combined to obtain a series of assembled units, such as... Figure 9 As shown;

[0080] 5-2) Fill the gaps in each column of assembly units with carbon twisted wire to prepare for mold closing;

[0081] 5-3) Using an integral positioning clamping plate, the individual units and non-through components filled with carbon twisted wire are assembled into a whole according to the design position, such as... Figure 10 and Figure 11 As shown;

[0082] 5-4) While assembling the mold, remove the pre-formed reinforcing components from their mounting molds and clamp them one by one between the columns of the assembled unit and the non-through components.

[0083] 5-5) The pre-formed peripheral baffle assembly is placed around the perimeter of the through-part and non-through-part components after the mold is closed, according to the designed position, and the four metal plate molds are locked together with bolts.

[0084] 5-6) After mold closing, fill the R-corners of each mesh connection with carbon twisted wire to prepare for hot pressing and co-curing in an autoclave. The co-curing parameters are: temperature 180±6℃, curing pressure 0.55~0.65Mpa, and holding time 150~220min.

[0085] 6) Demolding and Molding: After co-curing, the installation fixtures for each component are removed to obtain a variable curvature, variable cross-section orthogonal mesh composite material component, such as... Figure 12As shown.

[0086] Example 2

[0087] This embodiment describes the fabrication of a variable curvature, variable cross-section orthogonal mesh composite material component using the molding method described in Example 1. The structure of this variable curvature, variable cross-section orthogonal mesh composite material component is as follows: Figure 1 As shown, it includes a 3-row, 3-column orthogonal grid, where each column includes one non-through grid and two through grids, with the non-through grids located in the same row. Because one edge of this component has a variable curvature structure, ordinary molding fixtures are difficult to adapt, making it difficult to guarantee the molding quality of the inner and outer surfaces of the grid after molding. According to the molding method of Example 1, this embodiment divides the digital model, then designs a mold-laying fixture according to the shape of each grid, pre-forms each part of the prepreg separately, and then uses clamping plates to assemble them into a whole, which is then molded in an autoclave. The details are as follows:

[0088] like Figure 2 As shown, the digital model structure of the part is divided into a through-grid assembly, a non-through-grid assembly, a reinforcing layer assembly, and a perimeter baffle assembly. Based on the structural morphology of the through-grid, a flexible core mold installation fixture and a metal hot-pressing fixture are designed and fabricated, such as... Figure 3 and Figure 4 As shown; a metal male mold with a silicone layer was designed and manufactured based on the structural morphology of a non-through-mesh grid, such as... Figure 5 As shown; a metal cavity mold with a mounting groove is designed according to the structural morphology of the reinforcing layer, such as... Figure 7 As shown; four metal plate molds are designed according to the structural shape of the perimeter baffle, such as Figure 8 As shown, the baffle located on the side with variable curvature is designed as a straight plate with connecting holes on both ends; the two side baffles connected to the straight plate baffle are designed as L-shaped, with bolt through holes on the upper side that match the connecting holes of the first template for mold assembly; the outward turning part at the lower end serves as a positioning connection part for mold assembly with the third template; the template of the last baffle is designed with the middle part protruding upward to form a prepreg laying platform, and the two ends are slightly thinner as positioning connection areas that match the positioning connection parts of the L-shaped template for easy laying and mold assembly.

[0089] The prepregs used to prepare the part are divided into through-component prepregs, non-through-component prepregs, and reinforcing component prepregs according to the mold parting design. Each component prepreg is then laid onto its corresponding mold parting fixture as required. After laying, each component prepreg, along with its respective mold parting fixture, is placed into an autoclave for hot compaction. The hot compaction parameters are: hot pressing temperature 60–85℃, hot pressing pressure 0.5–0.65 MPa, and hot pressing holding time 30–50 min. This yields the through-component, non-through-component, and reinforcing components of the part. The through-components are then molded using a single-row positioning clamp to form assembly units, and carbon twisted wire is filled into the gaps in each row of assembly units. Figure 9 As shown; then, the through-type component assembly unit and the non-through-type grid component are molded together using an integral assembly plate, as shown. Figure 10 and Figure 11 As shown, a middle reinforcing layer component taken from the layup mold is sandwiched in the middle of each column. After each column is assembled, the pre-formed peripheral baffle assembly is placed around the perimeter of the through-type and non-through-type components after the mold is closed, according to the designed position, and the four metal plate molds are locked together with bolts. Then, carbon twisted wire is filled at the R-corners of each grid connection after the mold is closed. Finally, it is sent to a hot autoclave for hot-press co-curing; the co-curing parameters are temperature 185℃, curing pressure 0.6Mpa, and holding time 180min. After co-curing, the soft core mold, the metal male mold with silicone layer, and the four metal plate molds are removed to obtain a variable curvature and variable cross-section orthogonal grid composite material component, such as... Figure 12 As shown.

[0090] This invention employs a "soft mold + expanding silicone" assisted autoclave molding process, suitable for molding orthogonal mesh composite material components with varying curvature and cross-section. This molding method avoids fiber accumulation, wrinkling, and breakage at mesh intersections, while also reducing over- or under-pressure, thus improving component strength. Furthermore, this molding process ensures both the internal cavity shape and the external shape of the component, meeting diverse working conditions and having a wide range of applications. The manufacturing process is simple, with easy assembly and demolding of different molds, facilitating disassembly and reassembly. It is adaptable to various working conditions, has a wide range of applications, significantly improves production efficiency, and possesses excellent application value and promising prospects for widespread adoption.

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalent elements of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0092] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method of autoclave molding a variable curvature variable cross-section orthogrid composite structure, characterized by: The method comprises the following steps: 1) mold design: according to the numerical model of the variable curvature and variable cross-section orthogonal grid composite component to be formed, the structure is divided into through grid components, non-through grid components, intermediate reinforcement layer components and perimeter baffle components; 2) laying tool design: according to the structure of each component, the corresponding mold laying tool is designed and prepared, and the thickness and structure of each component are determined; wherein: the mold laying tool of the through grid component is a soft core mold and a hot compaction tool, the mold laying tool of the non-through grid component is a metal positive mold with a silica gel layer, the mold laying tool of the intermediate reinforcement layer component is a metal cavity mold with a laying groove, the mold laying tool of the perimeter baffle component comprises four metal plate molds that can be closed to form a frame; 3) mold laying: according to the division results of the mold design, the prepreg for preparing the variable curvature and variable cross-section orthogonal grid composite component is divided accordingly; and each component prepreg is laid on the corresponding mold laying tool according to the requirements; 4) mold preforming: after mold laying, each component prepreg is sent into a hot press tank together with the corresponding mold laying tool for hot compaction, to obtain through components, non-through components, reinforcement components and perimeter baffle components; 5) co-curing: after mold preforming, the through components, non-through components, reinforcement components and perimeter baffle components are assembled by positioning clamps according to requirements, and carbon twisted wires are filled at the R angles of each grid connection, and then sent into a hot press tank for hot pressing and co-curing; 6) demolding forming: after co-curing, the laying tool of each component is removed, and a variable curvature and variable cross-section orthogonal grid composite component is obtained.

2. The autoclave molding method of the variable-elasticity variable cross-section orthogrid composite member according to claim 1, characterized by: The soft core mold is a silica rubber airbag with a carbon fiber reinforcement layer inside, which includes a profile part in the middle and a clamping positioning part at both ends; The profile part is designed and manufactured according to the inner profile of the through grid of the variable curvature and variable cross-section orthogonal grid composite component; The clamping positioning part includes a clamping support section and a clamping sleeve section, and the cross-sectional area of the clamping support section is larger than that of the clamping sleeve section.

3. The autoclave molding method of the variable-elasticity variable cross-section orthogrid composite member according to claim 1, characterized by: The metal positive mold with a silica gel layer is prepared by a special injection tooling; The injection tooling is a closed structure with a silica gel forming gap inside consistent with the inner profile of the non-through grid of the variable curvature and variable cross-section orthogonal grid composite component, and a glue injection port at the top; the glue liquid for preparing the silica gel layer is injected into the silica gel forming gap through the glue injection port for curing and forming, thereby obtaining the required silica gel layer; The thickness of the silica gel layer is 12-15 mm, and the expansion amount at the hot pressing and co-curing temperature is 0.6-0.8 mm; The metal positive mold is provided with an assembly clamping section for closing the mold, and the assembly clamping section is located at the end away from the silica gel layer.

4. The autoclave molding method of the variable-elasticity variable- cross-section orthogrid composite member according to claim 1, characterized by: The metal cavity mold with a laying groove has a laying groove shape consistent with the shape of the divided intermediate reinforcement layer, and a depth consistent with the thickness of the divided intermediate reinforcement layer.

5. The autoclave molding method of the variable-choic variable cross-section orthogrid composite material member according to claim 1, characterized by: The four metal plate molds include: a first mold plate provided with connecting holes at both ends; Two second molds, one end side is provided with bolt through holes matched with the connecting holes of the first mold, the other end is outwardly turned to L-shaped as a positioning connecting part; A third mold is provided with a positioning connecting area matched with the positioning connecting part of the second mold at both ends, and the middle part is a prepreg laying platform.

6. The autoclave molding method of the variable-choic variable cross-section orthogrid compound material member according to claim 1, characterized by: In step 3), the said split laying: The through grid assembly prepreg is laid on the profile area of the soft core mold, and the hot compaction metal tooling is added on the outer profile of the prepreg; The non-through grid assembly prepreg is laid on the metal male mold with a silica gel layer, and is directly packaged and hot-pressed; The middle reinforcing layer assembly prepreg is laid in the laying groove of the metal cavity mold; The peripheral baffle assembly prepreg is laid on the corresponding four metal plate molds according to its position.

7. The autoclave molding method of the variable-choic variable cross-section orthogrid compound material member according to claim 2, characterized by: The said positioning clamping plate includes single-column positioning clamping plate and integral positioning clamping plate; The single-column positioning clamping plate is a plate-shaped body provided with a column of clamping sleeve rings matched with the clamping positioning part of the soft core mold; the size of the clamping sleeve ring is smaller than the cross-sectional dimension of the clamping support section, and can be exactly sleeved on the clamping sleeve section, so as to position and assemble a plurality of through assemblies into a column of assembly units; The integral positioning clamping plate is a polygonal frame body, which assembles a plurality of assembly units and non-through assemblies into a whole.

8. The autoclave molding method of the variable- curvature variable-stiffness orthogrid composite member according to claim 7, characterized by: The process of assembly is as follows: 5-1) first, the through assemblies are clamped on the clamping sleeve sections at both ends of the soft core mold in the corresponding positions of each single-column clamping plate by using the single-column clamping plate to sort by column, so as to combine the through assemblies and obtain a series of assembly units; 5-2) carbon twisted wires are filled in the gaps in each column of assembly units for assembly; 5-3) the integral positioning clamping plate is clamped on the clamping sleeve sections outside the single-column clamping plate, and the assembly units filled with carbon twisted wires and the non-through assemblies are assembled into a whole according to the designed position; 5-4) while assembling, the preformed reinforcing assemblies are removed from the laying mold and clamped between the columns of assembly units and non-through assemblies one by one; 5-5) the preformed peripheral baffle assembly is arranged around the through assemblies and non-through assemblies after assembly according to the designed position, and the four metal plate molds are locked by assembly through bolts; 5-6) carbon twisted wires are filled at the R angles of the grids connected in the whole after assembly for hot-pressing and co-curing in the hot-pressing pot.

9. The autoclave molding method of the variable-choic variable cross-section orthogrid compound material member according to claim 1, characterized by: The parameters for co-curing in the hot-pressing pot are: temperature 180±6℃, curing pressure 0.55-0.65Mpa, and holding time 150-220min.

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