Die for integrally forming honeycomb composite material core

Abstract

The invention discloses a mould for integrally forming a honeycomb composite material core. The device comprises an upper groove seat, a stud, an upper mold, a PTFE mold, a short frame, a long frame, a lower mold and a lower groove seat, the die has the advantages that the die is simple in structure and easy to machine, and die steel materials are not wasted; the die greatly increases the contact area of the core layer through the short frame or the long frame, and compared with a core of an existing hexagonal honeycomb composite material sandwich board, the hexagonal honeycomb composite material sandwich board is good in buckling deformation resistance and high in shear strength and compressive strength. The PTFE mold has extremely high chemical stability and extremely low friction coefficient, and the composite material core is easy to demold; the mold is reasonable in design and low in cost; honeycomb core structures with different wall thicknesses can be processed; and the mold is very convenient to assemble and disassemble.

Description

Technical Field

[0001] The invention belongs to the technical field of molding equipment, and in particular relates to a mold for integrally molding a honeycomb composite material core. Background Art

[0002] Compared with metal cores, composite cores have improved specific stiffness and specific strength, so they have excellent mechanical properties and a wide range of application scenarios.

[0003] Currently, the most widely used composite sandwich structure is the aramid honeycomb structure. However, the aramid core has low in-plane shear stiffness and strength, making it difficult to achieve high strength and low weight. Furthermore, the faceplates and core are in linear contact, resulting in low interfacial bonding strength. Honeycomb core structures made from high-performance composite materials such as carbon fiber offer higher strength and stiffness, and their increased contact area significantly enhances the strength of the bonding layer.

[0004] At present, the preparation of honeycomb composite material core structures is mostly made by gluing layers of corrugated plates together. This preparation method requires multiple moldings and is therefore relatively cumbersome. However, the composite honeycomb core prepared by the mold for integrated molding of honeycomb composite material cores not only has higher strength and rigidity, but also the preparation process is one-time molding, which is more convenient and quick. Summary of the Invention

[0005] In order to solve the above problems, the object of the present invention is to provide a mold for integrally molding a honeycomb composite material core.

[0006] In order to achieve the above-mentioned purpose, the mold for integrated molding of honeycomb composite material core provided by the present invention includes an upper groove seat, a stud, an upper mold, a PTFE mold, a short frame, a long frame, a lower mold and a lower groove seat; wherein, the upper mold and the lower mold are both plate-shaped structures, arranged horizontally in the up and down directions, and a plurality of parallel and corresponding slots are formed at equal intervals on the bottom surface of the upper mold and the top surface of the lower mold; the PTFE mold is a hexagonal structure, and a screw hole is formed at both ends of each PTFE mold. Multiple PTFE molds are stacked together in sequence along the up and down directions to form a row, and the lower part of the lowest PTFE mold in each row and the upper part of the highest PTFE mold are respectively inserted into a pair of corresponding slots on the lower mold and the upper mold, and the positions of adjacent rows of PTFE molds are staggered with each other; the long frame and the short frame are both strip-shaped, and a plurality of through holes are formed thereon at intervals along the length direction, which are arranged vertically in the horizontal direction, and the long frame and the short frame are staggered. The PTFE molds are stacked at both ends of multiple rows, and the PTFE molds of the same height in each row are connected by a long frame or a short frame. Then, each screw is passed through a through hole on the long frame or the short frame to be fixed in the corresponding screw hole of each PTFE mold, thereby fixing all PTFE molds to avoid displacement during installation and resulting in uneven core wall thickness; the lower groove seat is a U-shaped structure, with a screw hole formed at each end, and the two lower groove seats are arranged in parallel; the two side edges of the lower mold are respectively inserted into the grooves of the two lower groove seats; the upper groove seat is an inverted U-shaped structure, with a through hole formed at each end, and the two upper groove seats are arranged in parallel; the two side edges of the upper mold are respectively inserted into the grooves of the two upper groove seats; the lower end of each stud passes downward through a through hole on the upper groove seat and is threadedly connected to a corresponding screw hole on the lower groove seat, and the upper part of the stud is locked with a nut to provide the pressure required for core molding, so as to facilitate full curing of the prepreg.

[0007] The long frame and the short frame are both made of aluminum alloy.

[0008] The upper mold, the lower mold, the lower groove seat, the upper groove seat and the studs are all made of steel to ensure the molding effect of the honeycomb composite material core.

[0009] The upper and lower ends of the PTFE mold are relatively short edges, so as to facilitate the folding of the prepreg into a honeycomb shape and ensure that the prepreg is fully compressed and formed.

[0010] The longitudinal cross-section of the clamping grooves on the lower mold and the upper mold is the same as the longitudinal cross-section of the upper part or the lower part of the PTFE mold.

[0011] The beneficial effects of the present invention are:

[0012] 1. The mold of the present invention has a simple configuration, is easy to process, and does not waste mold steel materials;

[0013] 2. The mold of the present invention greatly increases the contact area of the core layer through the short frame or the long frame. Compared with the core of the existing hexagonal honeycomb composite sandwich panel, it has good anti-buckling deformation ability, high shear strength and compressive strength.

[0014] 3. The PTFE mold of the present invention has extremely high chemical stability and extremely low friction coefficient, and the composite material core is easy to demold; the mold of the present invention is reasonably designed and low in cost; honeycomb core structures with different wall thicknesses can be processed; and the assembly and disassembly of the mold is very convenient.

[0015] 4. The mold of the present invention can integrally mold the core, eliminating the subsequent step of bonding the core, thereby greatly improving the production efficiency.

[0016] 5. The short frame or long frame fixes each row of PTFE molds on the same horizontal plane to apply uniform and stable restraint force to the prepreg, thereby obtaining uniform wall thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a mold assembly diagram for the integrated molding of the honeycomb composite material core provided by the present invention.

[0018] Figure 2 This is a diagram of the stud structure in a mold for integrated molding of a honeycomb composite material core provided by the present invention.

[0019] Figure 3 This is a structural diagram of the upper groove seat in the mold for integrated molding of the honeycomb composite material core provided by the present invention.

[0020] Figure 4 This is a structural diagram of the lower groove seat in the mold for integrated molding of the honeycomb composite material core provided by the present invention.

[0021] Figure 5 This is a structural diagram of the short frame of a mold for integrated molding of the honeycomb composite material core provided by the present invention.

[0022] Figure 6 This is a structural diagram of the middle and long frame of a mold for integrally forming the honeycomb composite material core provided by the present invention.

[0023] Figure 7 This is a structural diagram of the middle and upper molds for the integrated molding of the honeycomb composite material core provided by the present invention.

[0024] Figure 8 This is a structural diagram of the PTFE mold in the mold for integrated molding of the honeycomb composite material core provided by the present invention. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figures 1 to 8 As shown, the mold for integrated molding of the honeycomb composite material core provided by the present invention includes an upper groove seat 1, a stud 2, an upper mold 3, a PTFE mold 4, a short frame 5, a long frame 6, a lower mold 7 and a lower groove seat 8; wherein, the upper mold 3 and the lower mold 7 are both plate-like structures, arranged horizontally in the up and down directions, and a plurality of parallel and corresponding slots are formed at equal intervals on the bottom surface of the upper mold 3 and the top surface of the lower mold 7; the PTFE mold 4 is a hexagonal structure, and a screw hole is formed at both ends of each PTFE mold 4, and multiple PTFE molds 4 are stacked together in the up and down directions to form a row, and the lower part of the lowest PTFE mold 4 in each row and the upper part of the highest PTFE mold 4 are respectively inserted into a pair of corresponding slots on the lower mold 7 and the upper mold 3, and the positions of the PTFE molds 4 in adjacent rows are staggered from each other; the long frame 6 and the short frame 5 are both strip-shaped, and a plurality of through holes are formed thereon at intervals along the length direction, which are arranged vertically in the horizontal direction, and the long frame 6 and the short frame 5 are staggered in a staggered manner. The PTFE molds 4 are stacked at both ends of multiple rows, and the PTFE molds 4 of the same height in each row are connected by a long frame 6 or a short frame 5. Then, each screw is passed through a through hole on the long frame 6 or the short frame 5 and fixed in the corresponding screw hole of each PTFE mold 4, thereby fixing all the PTFE molds 4 to avoid displacement during installation and resulting in uneven core wall thickness; the lower groove seat 8 is a U-shaped structure, with a screw hole formed at both ends, and the two lower groove seats 8 are arranged in parallel; the two side edges of the lower mold 7 are respectively inserted into the grooves of the two lower groove seats 8; the upper groove seat 1 is an inverted U-shaped structure, with a through hole formed at both ends, and the two upper groove seats 1 are arranged in parallel; the two side edges of the upper mold 3 are respectively inserted into the grooves of the two upper groove seats 1; the lower end of each stud 2 downwardly passes through a through hole on the upper groove seat 1 and is threadedly connected to a corresponding screw hole on the lower groove seat 8, and the upper part of the stud 2 is locked with a nut to provide the pressure required for core molding, so that the prepreg is fully cured.

[0027] The long frame 6 and the short frame 5 are both made of aluminum alloy.

[0028] The upper mold 3, the lower mold 7, the lower groove seat 8, the upper groove seat 1 and the stud 2 are all made of steel to ensure the molding effect of the honeycomb composite material core.

[0029] The upper and lower ends of the PTFE mold 4 are relatively short edges, so as to facilitate the folding of the prepreg into a honeycomb shape and ensure that the prepreg is fully compressed and formed.

[0030] The longitudinal cross-section of the clamping grooves on the lower mold 7 and the upper mold 3 is the same as the longitudinal cross-section of the upper part or the lower part of the PTFE mold 4.

[0031] The method for using the mold for integrally forming the honeycomb composite material core provided by the present invention is now described as follows:

[0032] Step 1: Clean the mold: Use a film cleaning agent to clean the outer surfaces of the upper mold 3, the lower mold 7 and the PTFE mold 4, and then apply a release agent to the outer surface of the lower mold 7;

[0033] Step 2: Heating the mold: Place the lower mold 7 and the PTFE mold 4 on a hot press or heating table to heat them. The heating temperature range is 10-20°C below the glass transition temperature of the prepreg.

[0034] Step 3: Laying prepreg: A layer of prepreg is laid on the lower mold 7. The lower ends of multiple PTFE molds 4 are then placed in the slots on the lower mold 7 and pressure is applied to completely press the prepreg into the slots, thereby folding the flat plate into a honeycomb shape. The second layer of prepreg is then laid. After each layer of prepreg is laid, the multiple PTFE molds 4 that have been laid can form a row of slots with the same equal spacing. This cycle can be repeated to lay the desired number of layers until the desired height is reached.

[0035] Step 4: Assemble the frames: Multiple long frames 6 and short frames 5 are stacked in a staggered manner at both ends of multiple rows of PTFE molds 4. Then, each screw is fixed to the corresponding screw hole of each PTFE mold 4 by passing through a through hole on the long frame 6 or the short frame 5. In this way, all PTFE molds 4 are fixed and a uniform and stable restraining force is applied to the prepreg to prevent displacement during the installation process and cause uneven core wall thickness.

[0036] Step 5. Clamp the mold: After covering the upper mold 3, constrain it through the lower groove seat 8, the upper groove seat 1 and the stud 2, and finally use the nut to tightly close the mold;

[0037] Step 6: Curing the prepreg: Curing the prepreg at a temperature of 100-200°C, a pressure of 0.3-0.5 MPa, and a curing time of 2-3 hours.

[0038] Step 7: Disassemble the mold: Loosen the nuts and remove the lower mold 7, the PTFE mold 4, and the upper mold 3 from the honeycomb core layer structure to obtain a honeycomb composite material core.

Claims

1. A mold for integrally forming a honeycomb composite material core, characterized by: The mold for integrally forming the honeycomb composite material core comprises an upper groove seat (1), a stud (2), an upper mold (3), a PTFE mold (4), a short frame (5), a long frame (6), a lower mold (7) and a lower groove seat (8); wherein the upper mold (3) and the lower mold (7) are both plate-shaped structures, arranged horizontally in the up-down direction, and a plurality of parallel and corresponding slots are formed on the bottom surface of the upper mold (3) and the top surface of the lower mold (7) at equal intervals; the PTFE mold (4) is a hexagonal prism structure, and the two ends of each PTFE mold (4) are A screw hole is formed on each of the plurality of PTFE molds (4) and the plurality of PTFE molds (4) are stacked in sequence in the up-down direction to form a row. The lower portion of the lowest PTFE mold (4) and the upper portion of the highest PTFE mold (4) in each row are respectively inserted into a pair of corresponding slots on the lower mold (7) and the upper mold (3), and the positions of the PTFE molds (4) in adjacent rows are staggered with each other. The long frame (6) and the short frame (5) are both strip-shaped, and a plurality of through holes are formed thereon at intervals along the length direction and are arranged vertically in the transverse direction. The long frame (6) and the short frame (5) are staggered. The PTFE molds (4) are stacked at both ends of multiple rows of PTFE molds (4), and the PTFE molds (4) of the same height in each row are connected by a long frame (6) or a short frame (5). Then, each screw is fixed in the corresponding screw hole of each PTFE mold (4) by passing through a through hole on the long frame (6) or the short frame (5), thereby fixing all the PTFE molds (4) to avoid displacement during installation and causing uneven core wall thickness; the lower groove seat (8) is a U-shaped structure, with a screw hole formed at each end, and the two lower groove seats (8) are arranged in parallel. The lower mold (7) is respectively inserted into the grooves of the two lower groove seats (8); the upper groove seat (1) is an inverted U-shaped structure, with a through hole formed at both ends, and the two upper groove seats (1) are arranged in parallel; the upper mold (3) is respectively inserted into the grooves of the two upper groove seats (1); the lower end of each stud (2) is downwardly penetrated through a through hole on the upper groove seat (1) and then threadedly connected to a corresponding screw hole on the lower groove seat (8), and the upper part of the stud (2) is locked by a nut to provide the pressure required for core molding, so as to facilitate the full curing of the prepreg.

2. The mold for integrally molding a honeycomb composite material core according to claim 1, characterized in that: The long frame (6) and the short frame (5) are both made of aluminum alloy.

3. The mold for integrally molding a honeycomb composite material core according to claim 1, characterized in that: The upper mold (3), the lower mold (7), the lower groove seat (8), the upper groove seat (1) and the stud (2) are all made of steel to ensure the molding effect of the honeycomb composite material core.

4. The mold for integrally molding a honeycomb composite material core according to claim 1, characterized in that: The upper and lower ends of the PTFE mold (4) are relatively short edges, so as to facilitate the folding of the prepreg into a honeycomb shape and ensure that the prepreg is fully compressed and formed.

5. The mold for integrally molding a honeycomb composite material core according to claim 1, characterized in that: The longitudinal cross-sections of the lower mold (7) and the upper grooves of the upper mold (3) are the same as the longitudinal cross-sections of the upper or lower parts of the PTFE mold (4).

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