A composite material open-cell frame, a forming die and a manufacturing method thereof

Abstract

The application provides a composite material opening frame, a forming die and a manufacturing method thereof, and belongs to the field of composite material forming. The problem that a structure with inconsistent thickness and an internal stiffening reinforcing structure are difficult to be synchronously formed is solved. The application relates to a composite material opening frame and a forming die. The opening frame is an integrally formed structure, and comprises side plates, a top plate and reinforcing plates. The top plate is octagonal, and a first opening is arranged at the center position. Four second openings are uniformly arranged on the top plate. The side plates are arranged around the top plate. The reinforcing plates are cross-shaped and have a square structure at the center. The reinforcing plates are arranged at the centers of the vertical direction and the horizontal direction of the top plate and are connected with the side plates. The forming die is used for processing the composite material opening frame. The composite material opening frame is mainly processed by the forming die through an integrally forming technology.

Description

Technical Field

[0001] This invention belongs to the field of composite material molding technology, and in particular relates to a composite material perforated frame, its molding die, and its manufacturing method. Background Technology

[0002] With the rapid development of high-end manufacturing fields such as aerospace and new energy vehicles, lightweighting and structural-functional integration have become core requirements for structural design. As a key sealing component of storage and transportation systems, the mechanical properties, environmental resistance, and service life of the storage tank cover directly affect the safety and reliability of the entire system.

[0003] Traditional tank cover opening frames are mostly made of metal materials such as aluminum alloy and titanium alloy. Although they have good machinability and fatigue resistance, they still have obvious limitations: First, the high density of metal materials leads to insufficient structural strength, resulting in a weight reduction bottleneck under high load conditions; Second, they are prone to stress corrosion or plastic deformation in extreme environments such as acid and alkali corrosion, humid heat or low temperature; Third, the problem of local stress concentration in welded or bolted connections becomes prominent, resulting in high long-term sealing maintenance costs.

[0004] Composite materials, due to their high strength, high modulus, and low density, are gradually becoming an ideal alternative to traditional metal materials. However, existing composite frame structures still face the following challenges in design and manufacturing:

[0005] Molding difficulties with inconsistent thickness: To meet the stress requirements of different areas, the frame thickness needs to be designed to be inconsistent. Traditional manufacturing methods are difficult to achieve integrated molding of structures with inconsistent thicknesses, usually requiring segmented manufacturing and then connection, which increases manufacturing costs and assembly difficulty.

[0006] The internal reinforcement structure is complex: In order to improve stiffness, the frame needs to be designed with internal stiffening and reinforcement structures. However, in the existing technology, these structures usually need to be prefabricated separately and then assembled with the main structure, which makes it difficult to achieve synchronous molding, resulting in uneven stiffness and strength of the overall structure.

[0007] Challenges of integrated molding: For products with complex structures and varying thicknesses, traditional molding methods struggle to achieve efficient and high-quality integrated manufacturing, resulting in high molding difficulty. Summary of the Invention

[0008] In view of this, the present invention aims to propose a composite material perforated frame, its molding die and manufacturing method, to solve the problems of difficult integral molding of composite material frames with large openings and inconsistent thickness, and complex internal reinforcement structures.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a composite material perforated frame, wherein the perforated frame is made of carbon fiber composite material and is an integrally molded structure with an octagonal outer contour. It includes side plates, a top plate, and reinforcing plates. The top plate is octagonal with a first opening at its center. Four second openings are evenly distributed on the top plate. Side plates are arranged around the top plate. The reinforcing plates are cross-shaped and have a square structure at their center. The reinforcing plates are respectively arranged at the center of the top plate in the vertical and horizontal directions and are connected to the side plates.

[0010] Furthermore, the overall height H of the perforated frame is 95mm, the minimum height h is 55mm, the radius of the first perforation is 30mm, and the radius of the second perforation is 137.5mm.

[0011] Furthermore, the top plate is 5mm thick, the reinforcing plate is 4mm thick, and the side plate is 1.8mm thick.

[0012] A molding die for a composite material perforated frame includes an inner segmented module, an outer segmented module, a pressure cap, a positioning block, and a base. The pressure cap is octagonal with four through holes. The positioning block is cubic with a central through hole, a cylindrical protrusion on the top surface, and a square protrusion on the bottom surface. Both the positioning block and the inner segmented module are mounted on the base, with the inner segmented module positioned outside the outer segmented module. The outer segmented module includes four short trapezoidal modules and four long trapezoidal modules. Short trapezoidal modules and long trapezoidal modules are alternately arranged around the inner segmented module. The inner segmented module includes four polygonal modules. Each module has a cylindrical protrusion on its upper surface and a cylindrical through hole in the middle. The top surface of the cylindrical protrusion on the module has a threaded hole. The side wall of the module has a stepped recess. The top surface of the base has a cross-shaped protrusion and four openings. The cross has a notch in the middle that matches the square protrusion on the bottom surface of the positioning block. The cross has a through hole in the middle, which corresponds to the through hole in the center of the positioning block.

[0013] Furthermore, threaded holes are provided around the outer perimeter of the four through holes of the pressure cap, and the threaded holes of the pressure cap correspond to the threaded holes of the module.

[0014] Furthermore, the base has four openings with threaded holes around the outer edge, which correspond to the positions of the threaded holes on the module.

[0015] Furthermore, the depth of the stepped recess in the module is 1.8 mm.

[0016] Furthermore, the inner diameter of the opening in the gland is 138 mm.

[0017] Furthermore, the base, outer segmented module, inner segmented module, positioning block, and pressure cap are all made of 45# steel.

[0018] A method for manufacturing a composite material perforated frame includes the following steps:

[0019] S1: Apply release agent to the surface of the inner segmented module group and the positioning block, and then install it in the center of the base after laying 2mm of prepreg around the positioning block;

[0020] S2: Apply 2mm of prepreg to the upper surface, inner side and stepped recess of each module of the inner segmented module. Use the prepreg to level the stepped recess on the outer side, and then install the inner segmented module on the base.

[0021] S3: Apply 1.2mm of prepreg to the upper surface of the module and positioning block, and then apply 1.8mm of prepreg to the top and side surfaces of the inner segmented module and the top surface of the positioning block.

[0022] S4: Install the outer segmented module around the inner segmented module, and then install the pressure cap on top of the inner segmented module;

[0023] S5: Vacuum pre-compact the entire mold by bagging it, and demold it after curing.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention achieves simultaneous molding of the frame body, openings, internal reinforcement, and local reinforcement through an integrated molding process, solving the problem of difficulty in achieving simultaneous molding of large openings, inconsistent overall structural thickness, and internal reinforcement structures in traditional manufacturing methods.

[0026] 2. This invention reduces overall costs by setting appropriate forming molds. The forming molds are made of 45# steel, which significantly reduces manufacturing costs compared to traditional high-cost nickel-based alloy molds.

[0027] 3. This invention achieves integrated molding of complex structures. By adopting a modular mold combination design and precise assembly of positioning blocks, it enables integrated demolding of structures with large openings, complex cross sections, and thickness differences, avoiding structural damage during disassembly. Furthermore, the modular mold combination supports rapid assembly and disassembly, shortening the production cycle of a single product. By adjusting the number of segmented molds, it can adapt to different opening sizes, and the molds can be reused.

[0028] 4. This invention improves the overall rigidity and strength of the product through an integrated molding process, while reducing manufacturing costs and molding difficulty, making it suitable for aerospace, automotive, and rail transportation industries. Attached Figure Description

[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 This is a schematic diagram of the axial side structure of a composite material perforated frame according to the present invention;

[0031] Figure 2 This is a schematic diagram of the front structure of a composite material perforated frame according to the present invention;

[0032] Figure 3 This is a top view schematic diagram of a composite material perforated frame structure according to the present invention;

[0033] Figure 4 This is a schematic diagram of the overhead structure of a composite material perforated frame according to the present invention;

[0034] Figure 5 An exploded view of a molding die for a composite material perforated frame according to the present invention;

[0035] Figure 6 This is a schematic diagram of the axial side structure of the long trapezoidal module of the molding die for a composite material perforated frame according to the present invention.

[0036] Figure 7 This is a front structural diagram of the long trapezoidal module of the molding die for a composite material perforated frame according to the present invention.

[0037] Figure 8 This is a top view schematic diagram of the long trapezoidal module of the molding die for a composite material perforated frame according to the present invention;

[0038] Figure 9 This is a schematic diagram of the axial side structure of the short trapezoidal module of the molding die for a composite material perforated frame according to the present invention;

[0039] Figure 10 This is a front structural diagram of the short trapezoidal module of the molding die for a composite material perforated frame according to the present invention.

[0040] Figure 11 This is a top view schematic diagram of the short trapezoidal module of the molding die for a composite material perforated frame according to the present invention.

[0041] Figure 12 This is a schematic diagram of the axial structure of a molding die module for a composite material perforated frame according to the present invention.

[0042] Figure 13 This is a front structural diagram of a module of a molding die for a composite material perforated frame according to the present invention.

[0043] Figure 14 This is a top view schematic diagram of the molding die module for a composite material perforated frame according to the present invention;

[0044] Figure 15 This is a schematic diagram of the top view of a module of a molding die for a composite material perforated frame according to the present invention.

[0045] Figure 16 This is a schematic diagram of the axial side structure of the positioning block of the molding die for a composite material perforated frame according to the present invention.

[0046] Figure 17 This is a front structural diagram of the positioning block of the molding die for a composite material perforated frame according to the present invention.

[0047] Figure 18 This is a top view schematic diagram of the positioning block of the molding die for a composite material perforated frame according to the present invention.

[0048] Figure 19 This is a schematic diagram of the upward structure of the positioning block of the molding die for a composite material perforated frame according to the present invention.

[0049] Figure 20 This is a schematic diagram of the axial side structure of the base of the molding die for a composite material perforated frame according to the present invention.

[0050] Figure 21 This is a front structural diagram of the base of the molding die for a composite material perforated frame according to the present invention.

[0051] Figure 22 This is a top view schematic diagram of the base of the molding die for a composite material perforated frame according to the present invention.

[0052] Figure 23 This is a schematic diagram of the base of the molding die for a composite material perforated frame according to the present invention, viewed from above.

[0053] Figure 24 This is a schematic diagram of the axial side structure of the pressure cap of the molding die for a composite material perforated frame according to the present invention.

[0054] Figure 25 This is a front structural diagram of the pressure cap of the molding die for a composite material perforated frame according to the present invention.

[0055] Figure 26 This is a top view schematic diagram of the molding die cap for a composite material perforated frame according to the present invention;

[0056] Figure 27This is a schematic diagram of the top surface structure of the pressure cap of the molding die for a composite material perforated frame according to the present invention.

[0057] In the picture:

[0058] 1. Side panel; 2. Top panel; 3. Reinforcing plate; 4. First opening; 5. Second opening; 6. Cover; 7. Short trapezoidal module; 8. Long trapezoidal module; 9. Positioning block; 10. Module; 11. Base. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0060] Detailed implementation method: See Figure 1-4 This embodiment describes a composite material perforated frame. The perforated frame is made of carbon fiber composite material, which significantly reduces the structural weight while providing excellent mechanical properties. The perforated frame is a one-piece molded structure with an octagonal outer contour. The octagonal structure has good mechanical properties and stability, effectively dispersing stress and reducing local stress concentration. It includes side plates 1, a top plate 2, and reinforcing plates 3. The top plate 2 is octagonal with a first opening 4 at its center. Four second openings 5 ​​are evenly distributed on the top plate 2. Side plates 1 are arranged around the top plate 2. The reinforcing plates 3 are cross-shaped with a square structure at their center. The reinforcing plates 3 are respectively located at the center of the top plate 2 in the vertical and horizontal directions and connected to the side plates 1. The cross-shaped reinforcing plates 3 can effectively enhance the bending and torsional resistance of the frame while maintaining the integrity of the structure. The composite material second perforated frame has a good surface condition, uniform thickness, and meets the design requirements in terms of shape and size.

[0061] The overall height H of the second opening frame is 95mm, the minimum height h is 55mm, the radius of the first opening 4 is 30mm, and the radius of the second opening 5 is 137.5mm.

[0062] The top plate 2 has a thickness of 5mm, the reinforcing plate 3 has a thickness of 4mm, and the side plate 1 has a thickness of 1.8mm.

[0063] See Figure 4-27This embodiment describes a molding die for a composite material perforated frame. It includes an inner segmented module, an outer segmented module, a pressure cap 6, a positioning block 9, and a base 11. The pressure cap 6 is an octagonal structure with four through holes. The pressure cap 6 covers the top of the molding die, providing pressure distribution during molding. The positioning block 9 is a cube with a central through hole, corresponding to the through hole in the base 11 for alignment within the mold. The top surface of the positioning block 9 has a cylindrical protrusion for contacting the inner segmented module. The module is designed to mate with a square protrusion on the bottom surface of the positioning block 9, which matches the notch in the middle of the cross-shaped protrusion on the base 11. The positioning block 9 serves as a support point inside the molding die. Both the positioning block 9 and the inner segmented module are mounted on the base 11. The inner segmented module is positioned outside the positioning block 9. The outer segmented module includes four short trapezoidal modules 7 and four long trapezoidal modules 8. The short trapezoidal modules 7 and long trapezoidal modules 8 are alternately arranged around the inner segmented module, and are designed to mate with the inner segmented module. The inner segmented module, through its cooperation, enables control over the external shape and size of the frame. The inner segmented module comprises four polygonal modules 10, each with a cylindrical protrusion on its upper surface and a cylindrical through-hole in the center. Threaded holes are formed on the top surface of the cylindrical protrusions on the module 10, with several vertically penetrating the module 10 and evenly distributed along the circumference. These threaded holes mate with the threaded holes of the base 11. The sidewalls of the module 10 have stepped recesses for forming the reinforcing plate structure within the frame sidewalls. The top surface of the base 11 has a cross-shaped protrusion and four openings. A notch matching the square protrusion on the bottom surface of the positioning block 9 is located in the center of the cross, mates with the square protrusion on the bottom surface of the positioning block 9. A through-hole is located in the center of the cross-shaped protrusion, corresponding to the through-hole in the center of the positioning block 9. The segmented design of the inner and outer segmented modules facilitates mold assembly and demolding, while also adapting to complex frame structures. The cooperation between the positioning block 9 and the base 11 ensures the alignment accuracy within the mold and improves molding quality.

[0064] The mold assembly relationship is as follows:

[0065] The positioning block 9 is installed in the center of the base 11. The bottom protrusion of the positioning block 9 corresponds to the notch in the center of the cross-shaped protrusion of the base 11. The inner segmented module is installed around the outside of the positioning block 9. The inner segmented module is fixed to the base 11 through threaded holes. The short trapezoidal module 7 and the long trapezoidal module 8 in the outer segmented module are alternately installed around the outside of the inner segmented module. The pressure cap 6 is installed on the top of the mold and fixed to the inner segmented module through threaded holes, covering the upper part of the entire mold. The above-mentioned molding mold is suitable for various composite material molding processes, has high versatility and scalability, and the assembly and disassembly process of the mold is simple and easy to operate. It can effectively shorten the production cycle and significantly improve production efficiency and product quality.

[0066] The pressure cap 6 has threaded holes around the four through holes on its outer perimeter. The threaded holes of the pressure cap 6 correspond to the threaded holes of the module 10, and the pressure cap 6 and the module 10 are connected through the threaded holes.

[0067] The base 11 has four openings with threaded holes around its outer edge, which correspond to the threaded holes of the module 10. The module 10 is connected to the base 11 through the threaded holes.

[0068] The stepped recess of module 10 has a depth of 1.8 mm.

[0069] The inner diameter of the opening in the pressure cap 6 is 138 mm.

[0070] The base 11, outer segmented module, inner segmented module, positioning block 9, and pressure cover 6 are all made of 45 steel.

[0071] See Figure 1-27 This embodiment describes a method for manufacturing a composite material perforated frame, comprising the following steps:

[0072] S1: Apply release agent to the surface of the inner segment mold and positioning block 9 to prevent the prepreg from sticking to the mold and facilitate subsequent demolding. Lay 2mm of prepreg around the positioning block 9 to ensure there are no bubbles or wrinkles. Then install the positioning block 9 in the center of the base 11 through the positioning device to ensure the accuracy of the positioning block 9's position.

[0073] S2: Apply 2mm of prepreg to the upper surface, inner side surface, and stepped recess of each module 10 of the inner segmented module. Use the prepreg to level the stepped recess on the outer side to ensure that the surface is flat and the thickness is uniform. Then install each module 10 of the inner segmented module on the base 11 in sequence and fix it to the base 11 through the threaded holes. At this time, the thickness of the prepreg between every two modules 10 is 4mm, and the thickness of the prepreg in the stepped recess on the outer side is also 4mm.

[0074] S3: Apply 1.2mm of prepreg to the upper surface of module 10 and positioning block 9, and then apply 1.8mm of prepreg to the top and side surfaces of the inner segmented module and the top surface of the positioning block. At this time, the thickness of the prepreg on the top surface of the inner segmented module is 5mm, and the thickness of the prepreg around the outer side of the inner segmented module is 1.8mm.

[0075] S4: Install the outer segmented module around the inner segmented module, ensuring a tight fit between the components. Use clamps or positioning pins to fix the outer segmented module. Then install the pressure cap 6 on top of the inner segmented module, ensuring good sealing between the pressure cap 6 and other molds.

[0076] S5: The overall mold is bagged, vacuumed and pre-compacted, and then sent to a hot autoclave for curing. That is, it is kept at 100°C for two hours, then the temperature is raised to 150°C and kept for two hours. After curing, it is cooled in the hot autoclave. Usually, the mold temperature is reduced to no more than 30°C of room temperature. After curing, it is allowed to cool and solidify before demolding. During demolding, the following order is followed: pressure cap 6, outer segmented module, base 11, inner segmented module and positioning block 9. Then the demolded product is polished flat to obtain the composite material second open frame.

[0077] Because the frame has many openings, large radii, and large overall thickness variations, the molding process is complex and difficult to produce. Therefore, this invention designs a molding die for a composite material frame, which can realize the one-piece molding of the composite material frame. The die combination is simple, the operation is easy, the single-piece production cycle is short, and it is easy to demold. Moreover, the composite material frame processed by the above steps has a good surface condition, uniform thickness, and the external dimensions meet the design requirements.

[0078] The specific embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A molding die for a composite material perforated frame, characterized in that: The composite material perforated frame is formed using a molding die for the composite material perforated frame. The molding die includes an inner segmented module, an outer segmented module, a pressure cap (6), a positioning block (9), and a base (11). The pressure cap (6) is an octagonal structure with four through holes. The positioning block (9) is a cube structure with a through hole in the center, a cylindrical protrusion on the top surface, and a square protrusion on the bottom surface. The positioning block (9) and the inner segmented module are both set on the base (11). The inner segmented module is set outside the outer block (9). The outer segmented module includes a short trapezoidal module (7) and a long trapezoidal module (8). There are four short trapezoidal modules (7) and four long trapezoidal modules (8). The short trapezoidal modules (7) and the long trapezoidal modules (8) are alternately arranged around the inner segmented module. The inner segmented module includes four polygonal modules (10). Each module (10) has a cylindrical protrusion on its upper surface and a cylindrical through hole in the middle. A threaded hole is provided on the top surface of the cylindrical protrusion on the block (10). A stepped recess is provided on the side wall of the module (10). A cross-shaped protrusion and four openings are provided on the top surface of the base (11). A notch matching the square protrusion on the bottom surface of the positioning block (9) is provided in the middle of the cross. A through hole is provided in the middle of the cross-shaped protrusion. The through hole corresponds to the through hole in the center of the positioning block (9). The opening frame is made of carbon fiber composite material and is an integrally molded structure with an octagonal outer contour. The opening frame includes a side plate (1), a top plate (2), and a reinforcing plate (3). The top plate (2) is octagonal and has a first opening (4) at the center. Four second openings (5) are evenly distributed on the top plate (2). Side plates (1) are provided around the top plate (2). The reinforcing plate (3) is cross-shaped and has a square structure at the center. The reinforcing plate (3) is respectively located at the center of the top plate (2) in the vertical and horizontal directions and is connected to the side plate (1).

2. The molding die for a composite material perforated frame according to claim 1, characterized in that: The overall height H of the perforated frame is 95mm, the minimum height h is 55mm, the radius of the first perforation (4) is 30mm, and the radius of the second perforation (5) is 137.5mm.

3. The molding die for a composite material perforated frame according to claim 1, characterized in that: The top plate (2) has a thickness of 5 mm, the reinforcing plate (3) has a thickness of 4 mm, and the side plate (1) has a thickness of 1.8 mm.

4. The molding die for a composite material perforated frame according to claim 1, characterized in that: The four through holes of the pressure cap (6) are provided with threaded holes around the perimeter, and the threaded holes of the pressure cap (6) correspond to the threaded holes of the module (10).

5. The molding die for a composite material perforated frame according to claim 4, characterized in that: The base (11) has four openings with threaded holes around its outer edge, which correspond to the threaded holes of the module (10).

6. The molding die for a composite material perforated frame according to claim 5, characterized in that: The stepped recess of the module (10) has a depth of 1.8 mm.

7. The molding die for a composite material perforated frame according to claim 1, characterized in that: The inner diameter of the opening of the pressure cap (6) is 138 mm.

8. The molding die for a composite material perforated frame according to claim 1, characterized in that: The base (11), outer segmented module, inner segmented module, positioning block (9) and pressure cover (6) are all made of No. 45 steel.

9. A method for manufacturing a composite material perforated frame using a molding die for a composite material perforated frame as described in claim 1, characterized in that, Includes the following steps: S1: Apply release agent to the surface of the inner segmented module group and the positioning block (9), and after laying 2mm of prepreg around the positioning block (9), install it in the center of the base (11); S2: Apply 2mm of prepreg to the upper surface, inner side and stepped recess of each module (10) of the inner segmented module, use the prepreg to level the stepped recess on the outer side, and then install the inner segmented module on the base (11). S3: Apply 1.2mm of prepreg to the upper surface of the module (10) and the positioning block (9), and then apply 1.8mm of prepreg to the top and side surfaces of the inner segmented module and the top surface of the positioning block; S4: Install the outer segmented module around the inner segmented module, and then install the pressure cap (6) on top of the inner segmented module; S5: Vacuum pre-compact the entire mold by bagging it, and demold it after curing.

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