Molding apparatus and molding method

Abstract

The application discloses a forming device and a forming method. The forming device comprises a first cover plate, a core barrel, a plurality of male die blocks, a plurality of female die blocks and a second cover plate. The first cover plate, the second cover plate, the plurality of male die blocks and the plurality of female die blocks are assembled to form the forming device. Since the barrel diameter of the core barrel gradually increases in the direction away from the first cover plate, and the thickness of the male die blocks gradually decreases in the direction away from the first cover plate, at least one male die block can be disassembled, and the position of the disassembled male die block provides a buffer space for the reinforcing fibers. In this way, the reinforcing fibers are smoothly and conveniently sleeved on the periphery of the plurality of male die blocks, and then the thin end of the disassembled male die block is inserted into the buffer space. The taper of the core barrel is used to gradually pressurize the male die blocks on the reinforcing fibers until the disassembled male die block is fixed in place to make the reinforcing fibers adhere to the male die, thereby preventing the reinforcing fibers from being torn and damaged, and improving the quality of the formed product.

Description

Technical Field

[0001] This application belongs to the field of composite material preparation technology, specifically relating to molding apparatus and molding method. Background Technology

[0002] Resin Transfer Molding (RTM) is a commonly used process in composite material manufacturing. The basic principle of RTM is to place glass fiber reinforcement material into a closed mold cavity, inject resin into the mold cavity under pressure to impregnate the glass fiber reinforcement material, and then cure and demold to form the finished product.

[0003] When the RTM process is used to mold an elliptical column structure, the reinforcing fiber is loaded into the tooling. Because the reinforcing material is light and relatively soft, external force can cause the reinforcing material to tear and be damaged when it comes into contact with the tooling, thus affecting the quality of the molded product. Summary of the Invention

[0004] In order to solve the technical problem of tearing and damage to the reinforcing material caused by external force causing it to adhere to the tooling in the related technology, this application provides a molding device and molding method.

[0005] A first aspect of this application provides a molding apparatus, the molding apparatus comprising:

[0006] First cover plate;

[0007] A core cylinder is detachably mounted on the first cover plate. The diameter of the core cylinder gradually increases along a preset direction, which is perpendicular to and away from the first cover plate.

[0008] Multiple punch blocks are sequentially and detachably arranged around the periphery of the core cylinder and respectively attached to the outer side wall of the core cylinder to form punches;

[0009] Multiple concave mold blocks are sequentially arranged around the periphery of the convex mold to form the concave mold. The concave mold and the convex mold are spaced apart. The concave mold and the first cover plate are detachably connected.

[0010] The second cover plate is located at the end of the core cylinder away from the first cover plate and is detachably connected to the core cylinder and the multiple concave mold blocks. The first cover plate, the second cover plate, the multiple convex mold blocks and the multiple concave mold blocks surround and form a molding cavity. The first cover plate or the second cover plate is provided with a conveying hole for conveying the curing material, and the conveying hole is connected to the molding cavity.

[0011] In some embodiments, the second cover plate has a mounting groove, and the end of the punch block away from the first cover plate is inserted into the mounting groove.

[0012] In some embodiments, the molding apparatus further includes:

[0013] A punch retaining ring is detachably connected to the first cover plate and located on the periphery of the core cylinder. The end of the punch assembly away from the second cover plate is located between the core cylinder and the punch retaining ring.

[0014] A second aspect of this application provides a molding method applied to the molding apparatus described above, the molding method comprising:

[0015] Place the first cover plate on the assembly platform;

[0016] The core cylinder, punch retaining ring, multiple punch blocks, multiple die blocks and a second cover plate are sequentially assembled onto the first cover plate to form a molding device. The second cover plate, the first cover plate, the multiple punch blocks and the multiple die blocks surround and form a molding cavity.

[0017] Flip the molding device over and place the second cover plate on the assembly platform;

[0018] Disassemble the first cover plate, the punch retaining ring, the multiple die blocks, and at least one punch block;

[0019] Fabricate reinforcing fibers and attach the reinforcing fibers to the periphery of the remaining multiple punch blocks;

[0020] Install the disassembled punch assembly into place;

[0021] The disassembled multiple concave mold pieces and the first cover plate are then installed in place.

[0022] The cured material is conveyed into the molding cavity through a conveying hole, which is opened in the first cover plate or the second cover plate. The cured material and the reinforcing fiber are cured to form a columnar structure.

[0023] The cylindrical structure is removed from the molding cavity of the molding device.

[0024] In some embodiments, the fabrication of the reinforcing fibers includes:

[0025] The first density needle-punched felt is set on the outer layer;

[0026] The second density needle-punched felt is disposed inside, the density of the first density needle-punched felt is greater than the density of the second density needle-punched felt, the first density needle-punched felt and the second density needle-punched felt are needle-punched felt structures and are connected by Z-direction needle punching.

[0027] Quartz cloth is interspersed within needle-punched felt of the first density and needle-punched felt of the second density, the needle-punched felt of the first density, the needle-punched felt of the second density, and the quartz cloth to form the reinforcing fiber.

[0028] In some embodiments, after the disassembled multiple concave mold pieces and the first cover plate are installed in place, the process includes:

[0029] After a preset time period, the multiple concave mold blocks and the first cover plate will be disassembled.

[0030] The needles at the folds of the reinforcing fibers are repaired using a mesh, and the excess parts of the reinforcing fibers are trimmed and adjusted.

[0031] The disassembled concave mold pieces and the first cover plate are then installed in place.

[0032] In some embodiments, the density of the needle-punched felt of the first density is 0.3 g / cm³. 3 Up to 0.35 g / cm 3 The density of the second density needle-punched felt is 0.2 g / cm³. 3 Up to 0.25 g / cm 3 The thickness of the quartz cloth is 0.06 mm to 0.2 mm.

[0033] In some embodiments, the curing material is a hybrid resin with a density of 0.3 g / cm³. 3 Up to 0.45 g / cm 3 .

[0034] In some embodiments, conveying the cured material into the molding cavity through a delivery hole includes:

[0035] The hybrid resin is injected into the molding cavity through a delivery hole at a temperature of 20°C to 40°C and a pressure of 0.05 MPa to 0.15 MPa.

[0036] In some embodiments, removing the column structure from the molding cavity of the molding apparatus includes:

[0037] Flip the molding device over and place the first cover plate on the assembly platform;

[0038] Disassemble the second cover plate, the multiple concave mold pieces, and the core cylinder;

[0039] Move the multiple punch blocks inward until they detach from the column structure;

[0040] Remove the cylindrical structure.

[0041] According to one or more embodiments of this application, the molding apparatus and molding method include a first cover plate, a core cylinder, multiple punch blocks, multiple die blocks, and a second cover plate. The first cover plate, the second cover plate, the multiple punch blocks, and the multiple die blocks are assembled to form the molding apparatus. Since the diameter of the core cylinder gradually increases away from the first cover plate, and the thickness of the punch blocks gradually decreases away from the first cover plate, at least one punch block can be disassembled to provide a buffer space for the reinforcing fiber. This allows the reinforcing fiber to be smoothly and conveniently fitted onto the periphery of the multiple punch blocks. Then, the thin end of the disassembled punch block is inserted into the buffer space. The taper of the core cylinder gradually applies pressure to the reinforcing fiber until the disassembled punch block is properly seated, allowing the reinforcing fiber to adhere to the die blocks, thereby preventing tearing and damage to the reinforcing fiber and improving the quality of the molded product. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the molding apparatus in one or more embodiments of this application;

[0043] Figure 2 This is a schematic diagram of the molding apparatus (omitting the two die blocks) in one or more embodiments of this application;

[0044] Figure 3 This is a schematic diagram of the molding apparatus (excluding the die block and the second cover plate) in one or more embodiments of this application;

[0045] Figure 4 This is a schematic diagram of the molding apparatus (omitting the concave die block, the second cover plate, and one of the convex die blocks) in one or more embodiments of this application;

[0046] Figure 5 This is a cross-sectional structural schematic diagram of the molding apparatus in one or more embodiments of this application;

[0047] Figure 6 This is a cross-sectional view of the molding apparatus from another angle in one or more embodiments of this application;

[0048] Figure 7 This is a flowchart of a molding method in one or more embodiments of this application.

[0049] Explanation of reference numerals in the attached figures:

[0050] 10. First cover plate; 20. Core cylinder; 30. Punch assembly; 40. Die assembly; 50. Second cover plate; 60. Elliptical column structure; 70. Forming cavity; 80. Punch retaining ring. Detailed Implementation

[0051] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0052] Resin Transfer Molding (RTM) is a commonly used process in composite material manufacturing. The basic principle of RTM is to place glass fiber reinforcement material into a closed mold cavity, inject resin into the mold cavity under pressure to impregnate the glass fiber reinforcement material, and then cure and demold to form the finished product.

[0053] In related technologies, when the RTM process is used to mold an elliptical cylindrical segment structure 60, reinforcing fibers are installed into the tooling. To ensure the appearance quality of the molded product, the dimensional tolerances of the reinforcing fibers and the tooling are relatively strict, typically ranging from 0.3mm to 0.5mm. Due to the shape and structure of the elliptical cylindrical segment structure 60, a certain external force needs to be applied during the transfer and installation of the reinforcing fibers into the tooling to ensure that the axial and radial positions of the reinforcing fibers and the tooling are consistent. Because the reinforcing material has a low density, is lightweight and relatively soft, external force causing the reinforcing material to adhere to the tooling can cause tearing damage to the reinforcing material, affecting the quality of the molded product.

[0054] To address the technical problem of tearing and damage to reinforcing materials caused by external forces causing them to adhere to tooling in related technologies, this application provides a molding apparatus and a molding method.

[0055] The first aspect of this application provides a molding apparatus, please refer to... Figures 1 to 3 The molding device is used to form an elliptical cylindrical structure 60 using the RTM process. The elliptical cylindrical structure 60 is a hollow cylindrical shape. The molding device includes a first cover plate 10, a core cylinder 20, a punch assembly 30, a die assembly 40, and a second cover plate 50.

[0056] The first cover plate 10 serves as the mounting base. The first cover plate 10 is rectangular and can increase the contact area with the assembly platform, thereby improving the stability of the molding device.

[0057] The core tube 20 is cylindrical, with a first threaded hole at one end and a first through hole (not shown in the figure) at the first cover plate 10. The screw is threadedly connected to the first threaded hole on the core tube 20 through the first through hole (not shown in the figure), so that the core tube 20 can be detachably installed on the first cover plate 10, and the axis of the core tube 20 is perpendicular to the plane of the first cover plate 10.

[0058] The punch assembly 30 is plate-shaped and consists of multiple pieces. These multiple punch assemblies 30 are sequentially and detachably arranged around the periphery of the core cylinder 20 and respectively adhere to the outer wall of the core cylinder 20 to form a punch. (See also...) Figure 3 The punch assembly 30 may consist of eight pieces, and the structural shapes of the eight punch assemblies 30 may differ depending on the contact position between the punch assembly 30 and the core cylinder 20. In some embodiments, the number and structural shape of the punch assembly 30 may be set according to the shape of the molded product and the shape of the core cylinder 20, and this application does not impose any limitations on them.

[0059] The die cavity block 40 is plate-shaped and consists of multiple pieces. These multiple die cavity blocks 40 are sequentially arranged around the periphery of the punch to form a die cavity, with the die cavity and punch spaced apart. Since the first cover plate 10 is rectangular, four die cavity blocks 40 can be provided. A first notch (not shown in the figure) is provided at the end of the die cavity block 40 near the first cover plate 10. The edge of the first cover plate 10 can be directly inserted into the first notch, improving the sealing performance of the connection between the die cavity block 40 and the first cover plate 10. A second through hole (not shown in the figure) is provided at the first notch position of the first cover plate 10, and a second threaded hole (not shown in the figure) is provided on the edge of the first cover plate 10. Screws are connected to the second threaded hole on the first cover plate 10 through the second through hole, allowing the die cavity block 40 to be detachably installed on the first cover plate 10, improving the stability of the connection between the die cavity block 40 and the first cover plate 10.

[0060] The second cover plate 50 is a rectangular cover plate located at the end of the core cylinder 20 away from the first cover plate 10, and is detachably connected to the core cylinder 20 and the multiple die assembly blocks 40. The second cover plate 50 has a third through hole (not shown in the figure) at the corresponding position of the core cylinder 20, and the core cylinder 20 has a third threaded hole (not shown in the figure) on the side away from the first cover plate 10. The screw is connected to the third threaded hole on the core cylinder 20 through the third through hole, so that the second cover plate 50 can be detachably installed on the core cylinder 20.

[0061] A second notch (not shown in the figure) is provided at the corresponding position of the die assembly 40 and the second cover plate 50. The edge of the second cover plate 50 can be directly inserted into the second notch, improving the sealing performance of the connection between the second cover plate 50 and the die assembly 40. A fourth through hole (not shown in the figure) is provided at the corresponding position of the second notch on the second cover plate 50. A fourth threaded hole (not shown in the figure) is provided on the side of the die assembly 40 away from the second cover plate 50. Screws are connected through the fourth through hole and the fourth threaded hole on the second cover plate 50, improving the connection stability between the die assembly 40 and the second cover plate 50.

[0062] It should be noted that the core cylinder 20 can also be detachably connected to the first cover plate 10 and the second cover plate 50 by snap-fit ​​or other means, and the concave mold block 40 can also be detachably connected to the first cover plate 10 and the second cover plate 50 by snap-fit ​​or other means. These can be set according to actual needs, and this application does not limit them.

[0063] Please see Figures 1 to 3 The first cover plate 10, the second cover plate 50, the multiple punch blocks 30 and the multiple die blocks 40 are assembled into a molding device. The first cover plate 10, the second cover plate 50, the multiple punch blocks 30 and the multiple die blocks 40 are arranged in the molding device to form a molding cavity 70. The first cover plate 10 has a conveying hole (not shown in the figure) which is connected to the molding cavity 70. The cured material can be conveyed into the molding cavity 70 through the conveying hole. The cured material and the reinforcing fiber in the molding cavity 70 are cured to form an elliptical column structure 60.

[0064] In some embodiments, the conveying hole may also be opened on the second cover plate 50, which can be set according to actual needs, and this application does not limit it.

[0065] Before the cured material is delivered into the molding cavity 70, the reinforcing fiber needs to be sleeved around the periphery of the multi-punch assembly 30 and located inside the molding cavity 70. Then the cured material is delivered into the molding cavity 70 and cured with the reinforcing fiber to form an elliptical columnar structure 60.

[0066] The elliptical column structure 60 is a regular column and is formed between multiple punch blocks 30 and multiple die blocks 40. The side wall of the punch block 30 away from the core cylinder 20 and the side wall of the die block 40 near the punch block 30 are perpendicular to the first cover plate 10, respectively.

[0067] Please see Figures 4 to 6 Since the diameter of the core cylinder 20 gradually increases along the preset direction, and the preset direction is perpendicular to and away from the first cover plate 10, and the thickness of the punch block 30 gradually decreases along the direction away from the first cover plate 10, when the reinforcing fiber is sleeved on the periphery of the multiple punch blocks 30, the assembled molding device can be flipped over, the second cover plate 50 can be placed on the assembly platform, the first cover plate 10, the multiple concave die blocks 40 and at least one of the punch blocks 30 can be disassembled, and the reinforcing fiber can be sleeved on the periphery of the remaining seven punch blocks 30. The removal of one punch block 30 from the punch provides a buffer space for the reinforcing fiber, allowing the reinforcing fiber to be smoothly and conveniently fitted around the seven punch blocks 30. Then, the thin end of the removed punch block 30 is inserted into the buffer space, and the taper of the core cylinder 20 gradually applies pressure to the reinforcing fiber using the punch block 30. The removal of the punch block 30 is then put into place so that the reinforcing fiber fits with the punch, preventing the reinforcing fiber from tearing and being damaged, and improving the quality of the molded product.

[0068] It should be noted that the assembled molding device can simultaneously disassemble multiple (two or three) punch blocks 30, and the positions where multiple punch blocks 30 are disassembled on the punch can provide buffer space for the reinforcing fibers.

[0069] After the reinforcing fiber is installed in place, the disassembled first cover plate 10 and the disassembled multiple concave mold blocks 40 can be assembled. Then, the curing material is transported to the molding cavity 70, so that the curing material and the reinforcing fiber are cured into an elliptical columnar structure 60.

[0070] Because the forming device needs to be rotated multiple times during the process of attaching the reinforcing fiber to the periphery of the multiple punch blocks 30, a mounting groove (not shown in the figure) is provided on the second cover plate 50 to prevent the positions of the punch blocks 30 and the die blocks 40 from shifting during the rotation of the forming device. The end of the punch block 30 away from the first cover plate 10 is inserted into the mounting groove. Please refer to [link to relevant documentation]. Figures 4 to 6 The molding device also includes a punch retainer ring 80, which is detachably connected to the first cover plate 10 and located on the periphery of the core cylinder 20. The end of the punch assembly 30 away from the second cover plate 50 is located between the core cylinder 20 and the punch retainer ring 80. This can limit the position of the punch assembly 30 and the die assembly 40, ensure the dimensional accuracy of the molding cavity 70, and improve the molding quality of the elliptical column structure 60.

[0071] It should be noted that the convex membrane retaining ring can be detachably connected to the first cover plate 10 or can be integrally formed with the first cover plate 10. It can be set according to actual needs, and this application does not limit it.

[0072] The second aspect of this application provides a molding method; please refer to [link / reference]. Figures 1 to 7 The molding methods include:

[0073] S202. Place the first cover plate 10 on the assembly platform.

[0074] S204. The core cylinder 20, the punch retaining ring 80, the multiple punch blocks 30, the multiple die blocks 40 and the second cover plate 50 are sequentially assembled on the first cover plate 10 to form a molding device. The second cover plate 50, the first cover plate 10, the multiple punch blocks 30 and the multiple die blocks 40 surround to form a molding cavity 70.

[0075] S206, Flip forming device, placing the second cover plate 50 on the assembly platform.

[0076] S208. Disassemble the first cover plate 10, the punch retaining ring 80, the multiple die assembly blocks 40 and at least one punch assembly block 30.

[0077] S210. Make reinforcing fibers and attach the reinforcing fibers to the periphery of the remaining multi-piece punch assembly 30.

[0078] The production of reinforcing fibers in S210 specifically includes:

[0079] S302, The needle-punched felt of the first density is set on the outer layer.

[0080] S304. The second density needle-punched felt is placed inside, the density of the first density needle-punched felt is greater than the density of the second density needle-punched felt, the first density needle-punched felt and the second density needle-punched felt are needle-punched felt structures and are connected by Z-direction needle punching.

[0081] S306. Quartz cloth is interspersed within needle-punched felt of first density and needle-punched felt of second density, the needle-punched felt of first density, the needle-punched felt of second density and quartz cloth forming reinforcing fibers.

[0082] The reinforcing fiber is a quartz needle-punched felt with a gradient structure; the density of the first density needle-punched felt is 0.3 g / cm³. 3 Up to 0.35 g / cm 3 The needle-punched felt on the outer layer of the formed elliptical column structure 60 has a high density, which improves the strength and ablation resistance of the elliptical column structure 60; the second density needle-punched felt has a density of 0.2 g / cm³. 3 Up to 0.25 g / cm 3 This results in a low density of the needle-punched felt inside the elliptical column structure 60, meeting the high-efficiency thermal insulation requirements of the elliptical column structure 60; the density of the mesh surface (achieved by overlapping multiple layers of mesh according to the product thickness requirements, with the joints between the multiple layers of mesh completed by needle punching, thus realizing the integrated structure of the product) is 45 g / cm³. 3 Up to 85g / cm 3 The density of the needle-punched felt in the inner and outer layers of the reinforcing fiber is controlled at 0.2 g / cm³. 3 Up to 0.35 g / cm 3 In this way, the weight of the needle-punched felt can be increased while maintaining its strength, thereby improving both the weight and strength of the reinforcing fibers. When the density of the needle-punched felt is less than 0.2 g / cm³... 3 If the strength of the reinforcing fiber cannot be guaranteed, the strength of the formed elliptical column structure 60 cannot be guaranteed, and thus the ablation resistance of the elliptical column structure 60 cannot be guaranteed.

[0083] Needle-punched felt and quartz cloth can be connected to form thin (0.08 mm to 0.1 mm) and high-strength (breaking strength greater than 1000 N) reinforcing fibers, making the strength of the reinforcing fibers higher than 40 MPa. This can improve the strength of the reinforcing fibers and thus improve the overall strength of the formed elliptical column structure 60.

[0084] It should be noted that the quartz cloth can be woven from type B, type C, or type D quartz yarn into plain weave, twill, or satin weave quartz cloth, with a weave thickness of 0.06 mm to 0.2 mm. Using quartz cloth with a thickness of 0.06 mm to 0.2 mm within needle-punched felt (including first-density and second-density needle-punched felt) can improve the overall strength of the reinforcing fibers.

[0085] S212. Install the disassembled punch assembly 30 into place.

[0086] S214. Install the disassembled multi-part concave mold assembly 40 and the first cover plate 10 into place.

[0087] As the diameter of the core cylinder 20 gradually increases along a preset direction, which is perpendicular to and away from the first cover plate 10, and the thickness of the punch block 30 gradually decreases along the direction away from the first cover plate 10, at least one punch block can be disassembled to provide a buffer space for the reinforcing fiber. This allows the reinforcing fiber to be smoothly and conveniently fitted around the periphery of multiple punch blocks. Then, the thin end of the disassembled punch block is inserted into the buffer space, and the taper of the core cylinder is used to gradually press the punch block against the reinforcing fiber until the disassembled punch block is in place, so that the reinforcing fiber adheres to the punch, thereby preventing the reinforcing fiber from tearing and being damaged, and improving the quality of the molded product.

[0088] S214 may also include:

[0089] S402. After a preset time, disassemble the multiple concave mold blocks 40 and the first cover plate 10.

[0090] The reinforcing fiber is installed inside the molding cavity 70 and sleeved around the periphery of the multiple punch blocks 30. The disassembled punch blocks 30, the disassembled multiple die blocks 40, and the first cover plate 10 are then installed in clockwise or counterclockwise order to assemble the molding device completely. The reinforcing fiber is pre-compressed and finally shaped within the molding cavity 70 of the molding device.

[0091] A skin is placed along the axial direction of the molding device at the connection point between the side contacts of two adjacent punch blocks 30. The skin is used to prevent the fabric from being squeezed and damaged at the mold joint during the mold closing process. A skin can also be placed at the connection point between two die blocks 40 along the axis of the molding device. The thickness of the skin is 0.4 mm to 0.6 mm. The use of the skin can control the size and appearance of the reinforcing fibers, ensure the accuracy of the reinforcing fiber size, and improve the molding quality of the elliptical column structure 60.

[0092] The molding device uses rigid materials such as steel and iron. The reinforcing fibers (including needle-punched felt and quartz cloth) are soft and have a compression ratio of approximately 1 mm. If the skin thickness is greater than 0.6 mm, the needle-punched felt cannot be compacted; if the skin thickness is less than 0.4 mm, the compressive force will be too great and damage the reinforcing fibers.

[0093] S406. Needle punching is used to repair the wrinkles of the reinforcing fibers with mesh, and excess reinforcing fibers are trimmed and adjusted.

[0094] S408. Install the disassembled multi-part concave mold assembly 40 and the first cover plate 10 into place.

[0095] S216. The cured material is conveyed into the molding cavity 70 through the conveying hole, which is opened in the first cover plate or the second cover plate. The cured material and the reinforcing fiber are cured to form a column structure.

[0096] To reduce the overall density of the molded elliptical column structure 60 and improve its lightweight nature, a hybrid phenolic resin is selected as the curing material. One of the lightweight phenolic resins such as HP-4, PF30, PF45, and FAM can be chosen. The molded elliptical column structure 60 is a phenolic resin-based thermal protection material. Phenolic resin-based thermal protection materials have good processability, wide temperature range adaptability, and excellent heat insulation capabilities, making them the preferred material for future aircraft thermal protection. By reducing the overall density of the elliptical column structure 60, the lightweight level of the elliptical column structure 60 can be improved; simultaneously, reducing the density of the elliptical column structure 60 can also reduce production costs. By controlling the strength of the outer layer of the elliptical column structure 60, its heat insulation performance can be enhanced.

[0097] Through the release of small molecules from the hybrid phenolic resin after curing, a porous and lightweight structure (nanoporous hybrid phenolic composite material) with elliptical columnar segments (60) is formed. The density of the hybrid phenolic resin is 0.3 g / cm³. 3 Up to 0.45 g / cm 3 This reduces the density of the elliptical column structure 60, increasing its lightweight while maintaining its strength. If the density of the hybrid phenolic resin is less than 0.3 g / cm³... 3 This results in a sacrifice in the bonding performance and ablation resistance of the elliptical column segment structure 60; the density of the hybrid phenolic resin is greater than 0.45 g / cm³. 3 This will increase the density of the elliptical column structure 60, affecting its lightweight design.

[0098] The hybrid phenolic resin is injected into the molding cavity 70 at a temperature of 20℃ to 40℃, with the pressure controlled between 0.05MPa and 0.15MPa. Due to the soft texture of the reinforcing material, the injection pressure (0.05MPa to 0.15MPa) provides good wettability to the reinforcing material, allowing the hybrid phenolic resin to fill the molding cavity 70 evenly, thus improving the uniformity and consistency of the elliptical column structure 60. If the injection pressure exceeds 0.15MPa, it will impact the surface of the reinforcing fibers, causing wrinkles and displacement, affecting the molding quality of the elliptical column structure 60.

[0099] After the glue injection is completed, the hybrid phenolic resin in the molding cavity 70 is cured. The curing temperature is raised from room temperature to 100℃. After curing and heat preservation (12h to 24h), the temperature is lowered to no higher than 60℃ for demolding.

[0100] S218. Remove the column structure from the forming cavity 70 of the forming device.

[0101] S218 specifically includes:

[0102] S502, The flipping forming device places the first cover plate 10 on the assembly platform.

[0103] S504. Disassemble the second cover plate 50, the multi-part concave mold assembly 40, and the core cylinder 20.

[0104] It should be noted that after the glue injection is completed, the multi-part concave mold assembly 40 can be disassembled, and the elliptical column structure 60 can be dried. The drying process uses a stepped temperature, with the highest temperature not exceeding 80℃.

[0105] S506. Move the multiple punch blocks 30 inward until they detach from the column structure.

[0106] S508. Remove the column structure. After removing the elliptical column segment structure 60, clean the burrs and excess adhesive from the outer end face of the elliptical column segment structure 60 by sanding, improving the appearance quality of the elliptical column segment structure 60. The density of the resulting elliptical column segment structure 60 (composite material) is 0.6 g / cm³. 3 Up to 0.65 g / cm 3 With a strength greater than or equal to 40MPa and a thermal conductivity (200℃) less than or equal to 0.08W / (m·K), it also has ablation resistance, thereby improving the lightweight level and heat insulation performance of the elliptical column structure 60 (phenolic resin-based thermal protection material) while reducing production costs.

[0107] The elliptical column structure 60 adopts the RTM injection molding process. The shape of the molded elliptical column structure 60 can be guaranteed to have net dimensions through the molding device, which reduces the damage to the elliptical column structure 60 and environmental pollution caused by machining. At the same time, it can save the molding cycle of the elliptical column structure 60 and reduce production costs.

[0108] The molding process of the elliptical columnar segment structure 60 (phenolic resin-based thermal protection material) includes:

[0109] (1) Make the fabric structure (reinforcing fibers).

[0110] A 1:1 mold was fabricated according to the model dimensions of the elliptical column segment structure 60. Along the thickness direction of the elliptical column segment structure 60, the outer layer was made of high-density needle-punched felt (0.3g / cm³). 3 Up to 0.35 g / cm 3 The interior uses low-density needle-punched felt (0.2g / cm³). 3 Up to 0.25 g / cm 3 The inner and outer surfaces are both needle-punched felt structures with Z-direction needle-punching connections. The needle-punched felt is filled with quartz cloth with a thickness of 0.06mm to 0.2mm.

[0111] (2) Fabricate tooling structure (forming device).

[0112] The forming device includes a first cover plate 10, a second cover plate 50, a punch assembly 30, a die assembly 40, a core cylinder 20, and a punch retaining ring 80.

[0113] When installing the reinforcing fiber of the elliptical column structure 60, the first cover plate 10 is placed on the assembly platform to assemble the molding device as a whole; then the molding device is flipped over and the second cover plate 50 is placed on the assembly platform. The concave mold block 40, the first cover plate 10, and one of the convex mold blocks 30 are removed; then the reinforcing fiber is sleeved around the periphery of the multiple convex mold blocks 30; finally, the disassembled convex mold blocks 30 are slowly lowered into place against the core cylinder 20 until they are installed in place, so that the molding device is reassembled.

[0114] (3) Cleaning of tooling structure (forming device).

[0115] Clean and dry the surface of the molding device (used to enclose the forming cavity 70).

[0116] (4) Fabric structure (reinforcing fiber) trial fitting.

[0117] The reinforcing fiber is sleeved around the periphery of the multi-piece punch block 30, and the molding device is assembled in a clockwise or counterclockwise order to pre-press and finally shape the reinforcing fiber.

[0118] (5) Cutting and trimming.

[0119] After the fabric structure (reinforcing fibers) is loaded into the molding device, it is pre-pressed for 2 to 3 hours. Then the mold is opened to check the flatness of the fabric structure (reinforcing fibers). Minor wrinkles in the reinforcing fibers are repaired by needle punching with a mesh, and excess areas are trimmed and adjusted.

[0120] (6) Mold closing.

[0121] The molding device is equipped with a sealing rope to ensure the sealing of the molding cavity 70 inside the molding device.

[0122] It should be noted that the molding device's surface (used to enclose the molding cavity 70) needs to be bonded with release cloth or sprayed with release agent, and the sealing performance of the molding device should be tested after the mold is closed.

[0123] (7) Select resin.

[0124] Choose one of the following low-density hybrid phenolic resins: HP-4, PF30, PF45, and FAM.

[0125] (8) Inject glue.

[0126] The hybrid phenolic resin is injected into the molding cavity 70 at a temperature of 20°C to 40°C, and the pressure is controlled at 0.05MPa to 0.15MPa.

[0127] (9) Curing.

[0128] After the glue injection is completed, the hybrid phenolic resin in the molding cavity 70 is cured. The curing temperature is raised from room temperature to 100℃. After curing and heat preservation (12h to 24h), the temperature is lowered to no higher than 60℃ for demolding.

[0129] (10) Drying treatment.

[0130] After the glue injection is completed, the multiple concave mold blocks 40 can be disassembled, and the elliptical column structure 60 (composite material) can be dried. The drying process adopts a stepped temperature, with the highest temperature not exceeding 80℃.

[0131] (11) Demolding.

[0132] After drying is complete, the forming device is flipped over, and the first cover plate 10 is placed on the assembly platform. The second cover plate 50, the multi-part concave mold assembly 40, and the core cylinder 20 are disassembled. The multi-part convex mold assembly 30 is moved inward until it is separated from the elliptical column structure 60, and the elliptical column structure 60 is removed.

[0133] (12) Elliptical column structure 60 surface polishing.

[0134] Clean the burrs and excess glue from the outer end face of the elliptical column segment 60.

[0135] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0136] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0137] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0138] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0139] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A molding method, applied to a molding apparatus, characterized in that, The molding device includes: a first cover plate; a core cylinder detachably mounted on the first cover plate, the diameter of the core cylinder gradually increasing along a preset direction, the preset direction being perpendicular to and away from the first cover plate; multiple punch blocks detachably arranged sequentially around the periphery of the core cylinder and respectively abutting against the outer side wall of the core cylinder to form punches; multiple die blocks detachably arranged sequentially around the periphery of the punches to form dies, the dies being spaced apart from the punches and detachably connected to the first cover plate; a second cover plate located at the end of the core cylinder away from the first cover plate and detachably connected to the core cylinder and the multiple die blocks, the first cover plate, the second cover plate, the multiple punch blocks, and the multiple die blocks forming a molding cavity, the first cover plate or the second cover plate having a conveying hole for conveying cured material, the conveying hole communicating with the molding cavity; The molding method includes: Place the first cover plate on the assembly platform; The core cylinder, punch retaining ring, multiple punch blocks, multiple die blocks and a second cover plate are sequentially assembled onto the first cover plate to form a molding device. The second cover plate, the first cover plate, the multiple punch blocks and the multiple die blocks surround and form a molding cavity. Flip the molding device over and place the second cover plate on the assembly platform; Disassemble the first cover plate, the punch retaining ring, the multiple die blocks, and at least one punch block; Fabricate reinforcing fibers and attach the reinforcing fibers to the periphery of the remaining multiple punch blocks; Install the disassembled punch assembly into place; The disassembled multiple concave mold pieces and the first cover plate are then installed in place. The cured material is conveyed into the molding cavity through a conveying hole, which is opened in the first cover plate or the second cover plate. The cured material and the reinforcing fiber are cured to form a columnar structure. The cylindrical structure is removed from the molding cavity of the molding device.

2. The molding method according to claim 1, characterized in that, The fabrication of the reinforcing fibers includes: The first density needle-punched felt is set on the outer layer; The second density needle-punched felt is disposed inside, the density of the first density needle-punched felt is greater than the density of the second density needle-punched felt, the first density needle-punched felt and the second density needle-punched felt are needle-punched felt structures and are connected by Z-direction needle punching. Quartz cloth is interspersed within needle-punched felt of the first density and needle-punched felt of the second density, the needle-punched felt of the first density, the needle-punched felt of the second density, and the quartz cloth to form the reinforcing fiber.

3. The molding method according to claim 1, characterized in that, After the disassembled multiple concave mold pieces and the first cover plate are installed in place, the process includes: After a preset time period, the multiple concave mold blocks and the first cover plate will be disassembled. The needles at the folds of the reinforcing fibers are repaired using a mesh, and the excess parts of the reinforcing fibers are trimmed and adjusted. The disassembled concave mold pieces and the first cover plate are then installed in place.

4. The molding method according to claim 2, characterized in that, The density of the first density needle-punched felt is 0.

3. Up to 0.35 The density of the second density needle-punched felt is 0.

2. Up to 0.25 The thickness of the quartz cloth is 0.06 mm to 0.2 mm.

5. The molding method according to claim 4, characterized in that, The curing material is a hybrid resin with a density of 0.

3. Up to 0.45 .

6. The molding method according to claim 5, characterized in that, The step of conveying the cured material into the molding cavity through the conveying hole includes: The hybrid resin is injected into the molding cavity through a delivery hole at a temperature of 20°C to 40°C and a pressure of 0.05 MPa to 0.15 MPa.

7. The molding method according to any one of claims 1 to 6, characterized in that, The step of removing the cylindrical structure from the molding cavity of the molding device includes: Flip the molding device over and place the first cover plate on the assembly platform; Disassemble the second cover plate, the multiple concave mold pieces, and the core cylinder; Move the multiple punch blocks inward until they detach from the column structure; Remove the cylindrical structure.

8. The molding method according to claim 1, characterized in that, The second cover plate has an installation groove, and the end of the punch block away from the first cover plate is inserted into the installation groove.

9. The molding method according to claim 8, characterized in that, The molding apparatus further includes: A punch retaining ring is detachably connected to the first cover plate and located on the periphery of the core cylinder. The end of the punch assembly away from the second cover plate is located between the core cylinder and the punch retaining ring.

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