Longitudinal ring band reinforced composite cabin section forming die and forming method thereof

Abstract

The application provides a longitudinal ring band reinforced form composite cabin section forming die and a forming method thereof, which comprises a core die, a split male die, an outer female die, a mouth frame pressing tool, an upper end frame pressing ring, a lower end frame pressing ring and a base. The core die is arranged in the center of the forming die and fixed on the base. The split male die is wrapped on the outer wall of the core die. A reinforcing ring groove is arranged on the split male die along the longitudinal direction and the circumferential direction. The mouth frame pressing tool is arranged on the outer side of the split male die. The upper end frame pressing ring is horizontally fixed on the upper end surface of the core die. The lower end frame pressing ring is horizontally fixed on the bottom surface of the core die. The outer female die is wrapped on the outer wall of the split male die. The cabin section has the consistency of the overall performance and quality, and the structure has high dimensional position precision, better surface state and good rigidity and bearing capacity.

Description

Technical Field

[0001] This invention relates to the field of composite material molding technology, and in particular to a molding die for a composite material compartment with longitudinal ring reinforcement and its molding method. Background Technology

[0002] With the development of the aerospace industry, especially the continuous improvement of aerospace material processing technology, composite materials are being used more and more widely in the field of cabin manufacturing. Compared with traditional metal materials, carbon fiber composites have the characteristics of high specific modulus and high specific strength, which can reduce the structural weight to the maximum extent while meeting structural performance requirements. However, when molding composite reinforced mesh cabins, which are widely used, it is necessary to open rib grooves in the metal male module and wind carbon fiber prepreg into the rib grooves to form a mesh structure. The mechanical properties of this structure are stable, but it is difficult to design and process the mold. It is not easy to apply pressure to both sides of the ribs, and the molding quality is difficult to control. In the harsh environment of flight, composite material cabins mostly adopt the form of reinforced mesh, while non-critical cabins can choose process methods with less processing difficulty and easier molding quality control. Functional frames located in cabins are generally opened by machining. The premise of ensuring mechanical performance is the continuity of composite fiber. However, machining opens disrupt the continuity of composite fiber, resulting in a reduction in structural stiffness and strength. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a molding die and molding method for composite material compartments with longitudinal ring reinforcement, which can ensure the consistency of overall performance and quality of the compartments, and make the structure have high dimensional and positional accuracy, better surface condition, and good rigidity and load-bearing capacity.

[0004] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0005] The present invention provides a longitudinally reinforced composite material compartment molding die, comprising a core mold, a segmented male mold, an outer female mold, a mouth frame pressing fixture, an upper end frame pressing ring, a lower end frame pressing ring, and a base. The core mold is placed at the center of the molding die and fixed on the base. The segmented male mold is wrapped around the outer wall of the core mold. Reinforcing annular grooves are provided on the segmented male mold along the longitudinal and circumferential directions. The mouth frame pressing fixture for pressing the exit frame feature on the surface of the compartment is installed on the outer side of the segmented male mold. The upper end frame pressing ring is horizontally fixed on the upper end surface of the core mold, and the lower end frame pressing ring is horizontally fixed on the bottom surface of the core mold. The outer female mold covers the outer wall of the segmented male mold.

[0006] Preferably, a boss feature is formed on the upper frame pressure ring.

[0007] Preferably, the core mold and the outer female mold are made of steel.

[0008] Preferably, the material of the segmented male mold is aluminum alloy.

[0009] Preferably, positioning pins and positioning pin holes are provided on the upper frame pressing ring, the lower frame pressing ring, the outer female mold, and the opening frame pressing fixture. The positioning pins and positioning pin holes are used to fix the relative positions of the upper frame pressing ring, the lower frame pressing ring, the outer female mold, and the opening frame pressing fixture.

[0010] Preferably, connecting holes are made between the upper frame pressing ring, the lower frame pressing ring, the outer female mold, the opening frame pressing tool and the core mold, respectively. The connecting holes are matched with bolts, and torque is applied between the upper frame pressing ring, the lower frame pressing ring, the outer female mold, the opening frame pressing tool and the core mold through the bolts.

[0011] The method for forming a composite material compartment with longitudinal ring reinforcement provided by the present invention includes the following steps:

[0012] S1. Making molding molds;

[0013] S2. Prepare the prepreg and cut it into templates using a cutting machine;

[0014] S3. Place the sample material on the corresponding reinforcing annular groove, the mouth frame pressing fixture, and the upper and lower end frames of the forming mold on the segmented male mold.

[0015] S4. Lay out the 90° layer of skin using prepreg and wrap the unidirectional narrow strip prepreg with tape wrapping adhesive. Lay out the remaining layers by hand.

[0016] S5. After the prepreg is laid out, press the reinforcing annular groove, the mouth frame pressing tool, the upper and lower end frames of the forming mold, and the skin.

[0017] S6. Close the molding mold and place it in a curing oven for high-temperature curing.

[0018] S7. Remove the molding die.

[0019] Preferably, the unidirectional narrow band width ranges from 5 to 15 mm.

[0020] Preferably, the curing regime is set as follows: temperature is 120-190℃, curing time is 7-8 hours, and the heating rate during curing is 1.5-2℃ / min.

[0021] Preferably, step S4 further includes:

[0022] S41. After the unidirectional narrow strip prepreg is laid out, the frame pressing fixture is used to press the frame feature. After pressing, it is wrapped with plastic film and then pre-pressed with a forming mold. At the same time, the upper frame pressing ring is used to press the boss feature.

[0023] S42. After the skin is laid out, the mouth frame features are pressed again using a mouth frame pressing fixture. After pressing, it is wrapped with plastic film, and then pre-pressed again using a forming mold.

[0024] The present invention can achieve the following technical effects:

[0025] 1. By reinforcing the annular groove longitudinally and circumferentially, the overall processability is improved, the molding difficulty is reduced, and demolding is easier, saving time and economic costs.

[0026] 2. By setting positioning pins and connecting holes in the upper and lower end frame pressing rings, the outer female mold and the opening frame pressing fixture, the fixture is connected by positioning, so that the outer female mold can only move along the normal direction of the positioning pins or connecting holes, thereby ensuring the compaction and surface accuracy of the product.

[0027] 3. By using a direct molding method to process the boss features and frame features, the mechanical properties are reduced due to fiber discontinuity caused by machining.

[0028] 4. By using a steel core mold and an outer female mold, and an aluminum alloy segmented male mold, the rigidity of the structure is ensured while reducing the possibility of deformation during mold use. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a composite material compartment molding die with longitudinal ring reinforcement provided in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the structure of the reinforced annular groove provided according to an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the structure of the boss feature provided in an embodiment of the present invention.

[0032] Figure 4 This is a structural schematic diagram of the frame feature provided in an embodiment of the present invention.

[0033] Figure 5 This is a flowchart of a method for forming a composite material compartment with longitudinal ring reinforcement according to an embodiment of the present invention.

[0034] The reference numerals in the attached drawings include: core mold 1, split male mold 2, external female mold 3, mouth frame pressing fixture 4, upper frame pressing ring 5, lower frame pressing ring 6, base 7, reinforcing annular groove 8, mouth frame feature 9, boss feature 10. Detailed Implementation

[0035] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0037] Figure 1 The structure of the molding die for the composite material compartment with longitudinal ring reinforcement provided in an embodiment of the present invention is shown.

[0038] like Figure 1 As shown, the longitudinal ring reinforced composite material compartment molding die provided in this embodiment of the invention includes a core mold 1, a segmented male mold 2, an outer female mold 3, a mouth frame pressing fixture 4, an upper frame pressing ring 5, a lower frame pressing ring 6, and a base 7. The core mold 1 is placed at the center of the molding die and fixed on the base 8. The segmented male mold 2 is wrapped around the outer wall of the core mold 1. Reinforcing annular grooves 8 are formed on the segmented male mold 2 along the longitudinal and circumferential directions. The mouth frame pressing fixture 4 is installed on the outer side of the segmented male mold 2. The upper frame pressing ring 5 is horizontally fixed on the upper end surface of the core mold 1, and the lower frame pressing ring 6 is horizontally fixed on the bottom surface of the core mold 1. The outer female mold 3 covers the outer wall of the segmented male mold 2. A boss feature 10 is formed on the upper frame pressing ring 5. The core mold 1 and the outer female mold 3 are made of steel. The segmented male mold 2 is made of aluminum alloy.

[0039] In the embodiments provided by the present invention, positioning pins and corresponding positioning pin holes can be provided in the upper frame pressing ring 5, the lower frame pressing ring 6, the outer female mold 3, and the opening frame pressing fixture 4. The positioning pins are used to fix the relative positions of the upper frame pressing ring 5, the lower frame pressing ring 6, the outer female mold 3, and the opening frame pressing fixture 4. Positioning pins and positioning pin holes can be provided between the upper frame pressing ring 5, the lower frame pressing ring 6, and the core mold 1, respectively. Connecting holes are provided between the upper frame pressing ring 5, the lower frame pressing ring 6, and the core mold 1, and torque is applied by bolt connection to achieve pressurization of the composite material compartment.

[0040] Figure 2 The structure of the reinforced annular groove provided in an embodiment of the present invention is shown.

[0041] like Figure 2 As shown, the reinforcing annular grooves 8 are evenly distributed in the circumferential and longitudinal directions of the molding die, and the inclination angle of the reinforcing annular grooves 8 is between 0 and 10° to ensure that the surface is continuous and smooth when the prepreg is laid.

[0042] Figure 3 The structure of the boss feature provided in an embodiment of the present invention is shown.

[0043] like Figure 3 As shown, the boss feature 10 formed by the upper frame pressure ring 5 can be directly solidified and pressed, so that when the product is pre-pressed using the molding die, the upper frame pressure ring 5 can focus on pressing and molding the boss feature 10, which is beneficial to further compact the prepreg and at the same time adjust it according to the compaction.

[0044] Figure 4 The structure of the frame feature provided in an embodiment of the present invention is shown.

[0045] like Figure 4 As shown, the mouth frame pressing tool 4 can be directly cured and pressed, presenting mouth frame features 9 on the cabin column section.

[0046] Figure 5 The flowchart of the method for forming a composite material compartment with longitudinal ring reinforcement provided in an embodiment of the present invention is shown.

[0047] like Figure 5 As shown, the method for forming a composite material compartment with longitudinal ring reinforcement provided in this embodiment of the invention includes the following steps:

[0048] S1. Make the molding mold.

[0049] S2. Prepare the prepreg and cut it into templates using a cutting machine;

[0050] S3. Place the prepreg on the corresponding reinforcing annular groove 8, the mouth frame pressing fixture 4, and the upper and lower end frames of the forming mold on the segmented male mold 2.

[0051] S4. Use prepreg to lay the skin. For the 90° layer, use tape wrapping adhesive to wrap the unidirectional narrow strip prepreg onto the product. The remaining layers are laid manually. During the laying process, vacuum once after laying 10 layers each time, so as to allow excess resin to evaporate and make it easier to compact the prepreg.

[0052] S41. After the unidirectional narrow strip prepreg is laid out, the frame pressing fixture 4 is used to press the frame feature 9. After pressing, it is wrapped with plastic film and then pre-pressed with a forming mold. At the same time, the upper frame pressing ring 5 is used to press the boss feature 10.

[0053] S42. After the skin is laid, use the frame pressing tool 4 to press the frame feature 9 again. After pressing, wrap it with plastic film. After wrapping, use the forming mold to pre-press again to further compact the prepreg and adjust it according to the compaction.

[0054] S5. After the prepreg is laid out, press the reinforcing annular groove 8, the mouth frame pressing tool 4, the upper and lower end frames of the forming mold, and the skin of the mold.

[0055] S6. Close the molding mold and place it in the curing oven for high-temperature curing. During the mold closing process, control the mold closing gap and accurately control the product size and position accuracy. After the requirements are met, place it in the oven for curing. The curing temperature is 120-190℃, the curing time is 7-8h, and the heating rate during curing is 1.5-2℃ / min.

[0056] S7. Remove the molding mold to obtain the longitudinally and circumferentially reinforced carbon fiber prepreg compartment.

[0057] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0059] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a composite material compartment with longitudinal ring reinforcement, characterized in that, Includes the following steps: S1. Making a molding die; the molding die includes a core mold (1), a segmented male mold (2), an outer female mold (3), a mouth frame pressing fixture (4), an upper frame pressing ring (5), a lower frame pressing ring (6), and a base (7). The core mold (1) is placed in the center of the molding die and fixed on the base (7). The segmented male mold (2) is wrapped around the outer wall of the core mold (1). A reinforcing annular groove (8) is provided on the segmented male mold (2) along the longitudinal and circumferential directions. The inclination angle of the reinforcing annular groove (8) is 0~10°, and it is used for the surface of the compartment. The mouth frame pressing fixture (4) of the face pressing exit frame feature (9) is installed on the outside of the split male mold (2). The upper frame pressing ring (5) is horizontally fixed on the upper end surface of the core mold (1). The lower frame pressing ring (6) is horizontally fixed on the bottom surface of the core mold (1). The outer female mold (3) covers the outer wall of the split male mold (2). A boss feature (10) is formed on the upper frame pressing ring (5). When the product is pre-pressed using the forming mold, the upper frame pressing ring (5) is used to press and form the boss feature (10). S2. Prepare the prepreg and cut it into templates using a cutting machine; S3. The template material is placed on the corresponding reinforcing annular groove (8) on the segmented male mold (2), the mouth frame pressing fixture (4), and the upper and lower end frames of the forming mold. S4. Lay out the 90° layer of skin using prepreg and wrap the unidirectional narrow strip prepreg with tape wrapping adhesive. Lay out the remaining layers by hand. S41. After the unidirectional narrow strip prepreg is laid, the frame pressing fixture (4) is used to press the frame feature (9). After pressing, it is wrapped with plastic film. After wrapping, the forming mold is used for pre-pressing. At the same time, the upper frame pressing ring (5) is used to press the boss feature (10). S42. After the skin is laid, the mouth frame feature (9) is pressed again using the mouth frame pressing fixture (4). After pressing, it is wrapped with plastic film. After wrapping, it is pre-pressed again using the forming mold. S5. After the prepreg is laid out, the reinforcing annular groove (8), the mouth frame pressing tool (4), the upper and lower end frames of the forming mold and the skin are pressed and formed. S6. Close the molding mold and place it in a curing oven for high-temperature curing. S7. Remove the molding die.

2. The method for preparing the longitudinally reinforced composite material compartment as described in claim 1, characterized in that, The core mold (1) and the external female mold (3) are made of steel.

3. The method for preparing the longitudinally reinforced composite material compartment as described in claim 1, characterized in that, The material of the segmented male mold (2) is aluminum alloy.

4. The method for preparing the longitudinally reinforced composite material compartment as described in claim 1, characterized in that, Positioning pins and positioning pin holes are provided on the upper frame pressing ring (5), the lower frame pressing ring (6), the outer female mold (3), and the mouth frame pressing fixture (4). The positioning pins and positioning pin holes are used to fix the relative positions of the upper frame pressing ring (5), the lower frame pressing ring (6), the outer female mold (3), and the mouth frame pressing fixture (4).

5. The method for preparing the longitudinally reinforced composite material compartment as described in claim 1, characterized in that, Connection holes are respectively opened between the upper frame pressure ring (5), the lower frame pressure ring (6), the outer female mold (3), the mouth frame pressing tool (4) and the core mold (1). The connection holes are engaged with bolts, and torque is applied between the upper frame pressure ring (5), the lower frame pressure ring (6), the outer female mold (3), the mouth frame pressing tool (4) and the core mold (1) through the bolts.

6. The method for preparing the longitudinally reinforced composite material compartment as described in claim 1, characterized in that, The width of the unidirectional narrow band ranges from 5 to 15 millimeters.

7. The method for preparing a composite material compartment with longitudinal ring reinforcement as described in claim 1, characterized in that, Curing regime settings: temperature 120~190℃, curing time 7~8 hours, heating rate during curing 1.5~2℃ / min.

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