A large-size honeycomb sandwich structure panel with an embedded reinforcement frame, a forming method thereof, and a pressurizing tool

Abstract

A large-sized honeycomb sandwich structure plate with an embedded reinforcement frame, a molding method thereof and a pressurizing tool. The present invention relates to a high-rigidity honeycomb sandwich structure plate and a molding method thereof, which is designed to solve the problem of the complicated molding process of the existing honeycomb sandwich structure plate using autoclave pressurization and curing. The large-sized honeycomb sandwich structure plate with an embedded reinforcement frame of the present invention comprises a reinforcement frame, an upper skin, a lower skin, a honeycomb core and metal embedded parts. The reinforcement frame is a rectangular frame, and the reinforcement frame is composed of a right-angle joint, two tee joints and a plurality of square tubes. A honeycomb core is arranged in the frame of the reinforcement frame, and the metal embedded parts are embedded in the honeycomb core. The upper skin and the lower skin are respectively glued to the upper and lower surfaces of the reinforcement frame. The molding method is to close the lower mold and the upper mold of the metal pressurizing tool, and tighten the bolts with a torque wrench to apply pressure. The present invention adopts a metal mold pressurization method, which is suitable for single small batch products, and the mold pressurization method can reduce the preparation cost.

Description

Technical Field

[0001] The invention relates to a high-rigidity honeycomb sandwich structure plate and a forming method and a forming tool thereof. Background Art

[0002] Honeycomb sandwich structures are common structural forms in the aerospace field. This is mainly because the honeycomb sandwich structure is light in weight and the installation interfaces of instruments and equipment can be arranged arbitrarily on the board, making it suitable for installing dispersed equipment. Usually composed of skin, honeycomb core, and adhesive, the usual honeycomb sandwich structure can meet the use requirements of general installation boards, but for honeycomb boards with high rigidity requirements, the rigidity of the honeycomb boards needs to be strengthened. According to research, the following four methods are usually used to strengthen the rigidity of honeycomb boards:

[0003] 1. Increasing the thickness of the panel is equivalent to increasing the thickness of the wing surface of the I-beam in the honeycomb sandwich structure, thereby increasing the rigidity. However, increasing the thickness of the panel will result in a heavier weight.

[0004] 2. Increasing the height of the honeycomb core is equivalent to increasing the moment of inertia of the section, which can improve the stiffness. However, some products are subject to size limitations and the overall product height cannot be changed.

[0005] 3. Choose honeycombs with small specifications and sizes. Once the honeycomb specifications are limited, the stiffness cannot be further improved.

[0006] 4. Embedded metal reinforcements. The processing cycle of metal reinforcements is short, but the weight is relatively heavy. The density of general aluminum alloy is 2.7g / cm 3 .

[0007] Moreover, most of the honeycomb sandwich structure panels are pressurized and cured in an autoclave. The honeycomb sandwich structure panels formed in an autoclave are pressurized evenly and have stable performance, but the cost is too high and the forming steps are complicated and numerous. Summary of the invention

[0008] The purpose of the present invention is to solve the problem of complicated molding process of existing honeycomb sandwich structure panels using autoclave pressure curing, and to provide a large-size honeycomb sandwich structure panel with an embedded reinforcement frame, a molding method and a molding tool thereof.

[0009] The large-size honeycomb sandwich structure panel with an embedded reinforcement frame of the present invention comprises a reinforcement frame, an upper skin, a lower skin, a honeycomb core and metal embedded parts, wherein the reinforcement frame is composed of a right-angle joint, two three-way joints and a plurality of square tubes, the reinforcement frame is a rectangular frame, the three-way joint is T-shaped, a right-angle joint is arranged at the right angle of the rectangular frame, a three-way joint is arranged at the midpoint of the long side of the rectangular frame, square tubes are glued between adjacent right-angle joints and between the right-angle joint and the three-way joint, and a square tube is glued between two three-way joints, a honeycomb core is arranged in the frame of the reinforcement frame, the metal embedded parts are embedded in the honeycomb core (at the position of the device to be connected), and the upper skin and the lower skin are glued to the upper surface and the lower surface of the reinforcement frame respectively.

[0010] The molding method of the large-size honeycomb sandwich structure plate with an embedded reinforcement frame of the present invention is implemented according to the following steps:

[0011] 1. Apply J47B+C adhesive film on the lower skin, glue the honeycomb core in the reinforcement frame, place the lower skin and the reinforcement frame on the carbon fiber positioning plate in sequence, locate the reinforcement frame according to the reference hole on the carbon fiber positioning plate, and locate the metal embedded parts in the honeycomb core by positioning screws to obtain the reinforcement frame + carbon fiber positioning plate assembly;

[0012] 2. Apply J47B glue 2-3 times on the upper surface of the reinforced frame. After drying, place the upper skin coated with J47B+C on the upper surface of the reinforced frame, and then place the reinforced frame + carbon fiber positioning plate assembly on the lower mold of the metal pressurized tooling;

[0013] 3. The lower mold and the upper mold of the metal pressurizing tool are closed, and the lower mold and the upper mold are connected by a connecting piece. The lower mold and the upper mold are tightened with a torque wrench to apply pressure. After the pressurization is completed, they are placed in a curing furnace. After the curing is completed, they are cooled to room temperature to obtain a large-sized honeycomb sandwich structure panel with an embedded reinforcement frame.

[0014] The pressurized tooling used for forming large-size honeycomb sandwich structure panels includes a lower mold, an upper mold and a positioning edge, wherein the upper mold is a rectangular frame structure mold, a plurality of square holes are separated by partitions in the frame structure of the upper mold, a plurality of positioning plates are respectively arranged at the lower part of the mold walls of the long sides of the upper mold, and each positioning plate on the upper mold is provided with two positioning stops;

[0015] The lower mold is a rectangular solid mold, and a positioning edge is provided on the upper surface of the lower mold. Multiple positioning plates are respectively provided on the long side mold walls of the lower mold. Two positioning stoppers are opened on each positioning plate on the lower mold. The upper mold and the lower mold are combined, and the upper mold and the lower mold are fastened together by connecting parts in the corresponding positioning stoppers above and below.

[0016] The large-size honeycomb sandwich structure plate with an embedded reinforcement frame of the present invention comprises a reinforcement frame, an upper skin, a lower skin, a honeycomb core and metal embedded parts. The honeycomb panel structure is strengthened by the reinforcement frame, thereby improving the rigidity of the conventional honeycomb sandwich structure plate. Its main molding method is that the upper skin, the lower skin, the honeycomb core and the reinforcement frame are glued by medium-temperature curing adhesive film J47B+C and J145 expansion adhesive. The square tube, the three-way joint and the corner joint are prepared by the metal mold pressurization method, and the mold is demoulded after the preparation is completed. After passing the flaw detection and size inspection, they are assembled by the gluing tool. After the frame processing is completed, the skin, the honeycomb core and the reinforcement frame are bonded by J47B+C and J145 expansion adhesive, and the frame and the metal embedded parts are positioned by the carbon fiber plate. After completion, the metal mold pressurization method is used for molding, which is suitable for single small batch products. The metal mold pressurization method can reduce the preparation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of a large-sized honeycomb sandwich structure panel with an embedded reinforcement frame according to the present invention;

[0018] Figure 2 It is a structural schematic diagram of a right-angle joint;

[0019] Figure 3 It is a structural schematic diagram of a three-way connector;

[0020] Figure 4 It is a structural schematic diagram of a pressurizing tool used for forming a large-size honeycomb sandwich structure panel in a tenth specific implementation mode;

[0021] Figure 5 It is a structural schematic diagram of the positioning edge fixing method of the metal pressurizing tool in the fourteenth specific implementation method. DETAILED DESCRIPTION

[0022] Specific implementation method one: The large-size honeycomb sandwich structure panel with an embedded reinforcement frame in this implementation method includes a reinforcement frame, an upper skin 1, a lower skin 2, a honeycomb core 6 and metal embedded parts, wherein the reinforcement frame is composed of a right-angle joint 3, two three-way joints 5 and a plurality of square tubes 4, the reinforcement frame is a rectangular frame, the three-way joint 5 is T-shaped, a right-angle joint 3 is arranged at the right angle of the rectangular frame, a three-way joint 5 is arranged at the midpoint of the long side of the rectangular frame, square tubes 4 are glued between adjacent right-angle joints 3 and between the right-angle joint 3 and the three-way joint 5, and square tubes 4 are glued between two three-way joints 5, a honeycomb core 6 is arranged in the frame of the reinforcement frame, metal embedded parts are embedded in the honeycomb core 6 (at the position of the device to be connected), and the upper skin 1 and the lower skin 2 are glued to the upper surface and the lower surface of the reinforcement frame respectively.

[0023] The large-sized honeycomb sandwich structure panel with embedded reinforcement frame in this embodiment mainly includes upper skin, lower skin, honeycomb and reinforcement frame, wherein the reinforcement frame is composed of composite square tube, three-way joint and corner joint. The reinforcement frame is bonded with honeycomb, upper and lower skins by adhesive film and expansion adhesive. This embodiment is suitable for forming honeycomb sandwich panels with embedded reinforcement frame, which solves the disadvantage of low rigidity of conventional honeycomb sandwich panels. It adopts metal mold forming process instead of autoclave forming process, and has the characteristics of simple forming method, low cost and high efficiency. It is mainly used in the fields of space station and satellite manufacturing.

[0024] Specific implementation method 2: This implementation method is different from the specific implementation method 1 in that the square tube 4 is a carbon fiber / epoxy resin composite material, the carbon fiber is M55JB or M60JB, and the epoxy resin is TDE85, AG80 or AFG90.

[0025] Specific implementation method three: This implementation method is different from specific implementation methods one or two in that the thickness of the upper skin 1 and the lower skin 2 is 0.3-0.5 mm.

[0026] Specific implementation method 4: This implementation method is different from any one of specific implementation methods 1 to 3 in that the material of the upper skin 1 and the lower skin 2 is a carbon fiber / epoxy resin composite material, the carbon fiber is M55JB or M60JB, and the epoxy resin is TDE85, AG80 or AFG90.

[0027] In this embodiment, the upper skin and the lower skin are prepared by wet winding + vacuum bag pressing method.

[0028] Specific implementation mode 5: This implementation mode is different from specific implementation modes 1 to 4 in that the honeycomb core 4 is made of aluminum honeycomb or aramid paper honeycomb, wherein the aluminum honeycomb is made of 5A02 aluminum alloy and is a regular hexagonal aluminum honeycomb core.

[0029] This embodiment uses Class II aluminum honeycomb core material with a nominal density of 27-44 kg / m 3 .

[0030] Specific implementation method 6: The difference between this implementation method and specific implementation methods 1 to 5 is that the metal embedded parts are made of aluminum alloy or magnesium alloy embedded parts, and the surface of the metal embedded parts is anodized or chemically oxidized.

[0031] Specific implementation method 7: The molding method of the large-size honeycomb sandwich structure plate with an embedded reinforcement frame in this implementation method is implemented according to the following steps:

[0032] 1. Apply J47B+C adhesive film on the lower skin 2, glue the honeycomb core 6 in the reinforcement frame, place the lower skin 2 and the reinforcement frame on the carbon fiber positioning plate in sequence, locate the position of the reinforcement frame according to the reference hole on the carbon fiber positioning plate, locate the metal embedded parts in the honeycomb core 6 by the positioning screws, and obtain the reinforcement frame + carbon fiber positioning plate assembly;

[0033] 2. Apply J47B glue 2-3 times on the upper surface of the reinforcement frame. After drying, place the upper skin 1 coated with J47B+C on the upper surface of the reinforcement frame, and then place the reinforcement frame + carbon fiber positioning plate assembly on the lower mold 7 of the metal pressurizing tooling;

[0034] 3. The lower mold 7 and the upper mold 8 of the metal pressurizing tooling are closed, and the lower mold 7 and the upper mold 8 are connected by a connecting piece. The lower mold 7 and the upper mold 8 are tightened with a torque wrench to apply pressure. After the pressurization is completed, they are placed in a curing furnace. After the curing is completed, they are cooled to room temperature to obtain a large-sized honeycomb sandwich structure panel with an embedded reinforcement frame.

[0035] In this embodiment, the strengthening frame is glued to the skin and metal embedded parts, wherein J47C+B glue film is used on the skin surface, and the glue mold thickness is controlled between 0.1 and 0.2 mm. J145 or J47D expansion glue is used to glue the strengthening frame to the metal embedded parts, and the filling range is 1 to 3 honeycomb circles near the metal parts.

[0036] Specific embodiment eight: The difference between this embodiment and specific embodiment seven is that the honeycomb core 6 is glued to the reinforcement frame by J145 or J47D foam glue.

[0037] Specific embodiment 9: The difference between this embodiment and specific embodiment 7 is that the curing is performed at a temperature of 120° C. to 140° C. for 3 to 5 hours.

[0038] Specific embodiment ten: The pressurized tooling for forming a large-size honeycomb sandwich structure panel in this embodiment includes a lower mold 7, an upper mold 8 and a positioning edge 11, wherein the upper mold 8 is a rectangular parallelepiped frame structure mold, and a plurality of square holes 10 are separated by partitions in the frame structure of the upper mold 8, and a plurality of positioning plates 9 are respectively arranged at the lower part of the long side mold walls on both sides of the upper mold, and each positioning plate 9 on the upper mold 8 has two positioning stoppers;

[0039] The lower mold 7 is a rectangular solid mold, and a positioning edge 11 is provided on the upper surface of the lower mold 7. A plurality of positioning plates 9 are respectively provided on the long side mold walls of the lower mold 7. Each positioning plate 9 on the lower mold 7 has two positioning stoppers. The upper mold 8 and the lower mold 7 are combined with each other, and the upper mold 8 and the lower mold 7 are fastened together by connecting parts in the corresponding positioning stoppers.

[0040] Specific embodiment eleven: This embodiment is different from the specific embodiment ten in that reinforcing ribs are provided on the positioning plate 9 of the upper mold 8, and reinforcing ribs are also provided on the positioning plate 9 of the lower mold 7.

[0041] Specific embodiment 12: The difference between this embodiment and specific embodiment 10 is that the positioning plates (9) on the two long side mold walls of the upper mold (8) are symmetrically arranged.

[0042] Specific embodiment 13: The difference between this embodiment and specific embodiment 10 is that 5 to 8 positioning plates (9) are respectively provided at the lower part of the long side mold walls on both sides of the upper mold (8).

[0043] Specific implementation fourteen: This implementation is different from specific implementation ten in that the connecting member is a bolt.

[0044] Specific embodiment 15: This embodiment differs from specific embodiment 10 in that the positioning edge (11) is fixed to the upper surface of the lower mold (7) by screws.

[0045] Embodiment: The molding method of the large-size honeycomb sandwich structure plate with embedded reinforcement frame in this embodiment is implemented according to the following steps:

[0046] 1. Apply J47B+C adhesive film on the lower skin, paste 1mm J47D expansion adhesive inside the reinforcement frame, glue the honeycomb core, place the lower skin and reinforcement frame on the carbon fiber positioning plate in sequence, locate the reinforcement frame according to the reference hole on the carbon fiber positioning plate, locate the metal embedded parts in the honeycomb core by positioning screws, and obtain the reinforcement frame + carbon fiber positioning plate assembly;

[0047] Second, apply J47B glue 3 times on the upper surface of the reinforced frame, and after drying, place the upper skin coated with J47B+C on the upper surface of the reinforced frame. The metal pressurizing tooling includes a lower mold 7, an upper mold 8 and a positioning edge 11. The upper mold 8 is a rectangular frame structure mold. A plurality of square holes 10 are separated by partitions in the frame structure of the upper mold 8. A plurality of positioning plates 9 are respectively arranged at the lower part of the long side mold walls on both sides of the upper mold. Two positioning stoppers are provided on each positioning plate 9 on the upper mold 8.

[0048] The lower mold 7 is a rectangular solid mold, and a positioning edge 11 is provided on the upper surface of the lower mold 7. A plurality of positioning plates 9 are respectively provided on the mold walls of the long sides of the lower mold 7. Two positioning stoppers are provided on each positioning plate 9 of the lower mold 7. The upper mold 8 and the lower mold 7 are molded together. The upper mold 8 and the lower mold 7 are fastened and connected by bolts in the corresponding positioning stoppers above and below, and the reinforcement frame + carbon fiber positioning plate assembly is placed in the positioning edge 11 of the lower mold 7;

[0049] 3. The lower mold 7 and the upper mold 8 of the metal pressurizing tool are closed, and the positioning is performed through the positioning stop of the lower mold 7 and the upper mold 8. The bolts are tightened with a torque wrench to apply pressure. After the pressurization is completed, it is placed in a curing furnace with a curing temperature of 130±5℃ and a time of 4h. After the curing is completed, it is cooled to room temperature to obtain a large-sized honeycomb sandwich structure panel with an embedded reinforcement frame.

[0050] The large-size honeycomb sandwich structure panel with an embedded reinforcement frame in this embodiment comprises a reinforcement frame, an upper skin 1, a lower skin 2, a honeycomb core 6 and metal embedded parts, wherein the reinforcement frame is composed of a right-angle joint 3, two three-way joints 5 and a plurality of square tubes 4, the reinforcement frame is a rectangular frame, the three-way joint 5 is T-shaped, a right-angle joint 3 is arranged at the right angle of the rectangular frame, a three-way joint 5 is arranged at the midpoint of the long side of the rectangular frame, square tubes 4 are glued between adjacent right-angle joints 3 and between the right-angle joint 3 and the three-way joint 5, and square tubes 4 are glued between two three-way joints 5, a honeycomb core 6 is arranged in the frame of the reinforcement frame, metal embedded parts are embedded in the honeycomb core 6, and an upper skin 1 and a lower skin 2 are glued to the upper surface and lower surface of the reinforcement frame respectively.

[0051] The area of ​​the large-sized honeycomb sandwich panel obtained in this embodiment can reach 3m 2 The rigidity is 5 to 10 times higher than that of a simple honeycomb sandwich structure. It is mainly for single pieces and small batches, and the cost is lower than that of an autoclave (mainly considering the maintenance cost of the autoclave).

Claims

1. A method for forming a large-size honeycomb sandwich structure plate with an embedded reinforcement frame, the large-size honeycomb sandwich structure plate with an embedded reinforcement frame comprising a reinforcement frame, an upper skin (1), a lower skin (2), a honeycomb core (6) and metal embedded parts, wherein the reinforcement frame is composed of a right-angle joint (3), two three-way joints (5) and a plurality of square tubes (4), the reinforcement frame is a rectangular frame, the three-way joint (5) is in a T-shape, a right-angle joint (3) is arranged at the right angle of the rectangular frame, a three-way joint (5) is arranged at the midpoint of the long side of the rectangular frame, square tubes (4) are glued between adjacent right-angle joints (3) and between the right-angle joint (3) and the three-way joint (5), and a square tube (4) is glued between two three-way joints (5), a honeycomb core (6) is arranged in the frame of the reinforcement frame, the metal embedded parts are embedded in the honeycomb core (6), and the upper skin (1) and the lower skin (2) are glued to the upper surface and the lower surface of the reinforcement frame respectively; characterized in that The molding method is implemented according to the following steps:

1. Apply J47B+C adhesive film on the lower skin (2), glue a honeycomb core (6) in the reinforcement frame, place the lower skin (2) and the reinforcement frame on the carbon fiber positioning plate in sequence, locate the reinforcement frame according to the reference hole on the carbon fiber positioning plate, locate the metal embedded parts in the honeycomb core (6) by means of positioning screws, and obtain a reinforcement frame + carbon fiber positioning plate assembly; 2. Apply J47B glue 2-3 times on the upper surface of the reinforcement frame, and after drying, place the upper skin (1) coated with J47B+C on the upper surface of the reinforcement frame, and then place the reinforcement frame + carbon fiber positioning plate assembly on the lower mold (7) of the metal pressurizing tooling; 3. The lower mold (7) and the upper mold (8) of the metal pressurizing tool are closed, the lower mold (7) and the upper mold (8) are connected by a connecting piece, the lower mold (7) and the upper mold (8) are tightened by a torque wrench to apply pressure, after the pressurization is completed, they are placed in a curing furnace, and after the curing is completed, they are cooled to room temperature to obtain a large-sized honeycomb sandwich structure panel with an embedded reinforcement frame; The pressurizing tooling comprises a lower die (7), an upper die (8) and a positioning edge (11); the upper die (8) is a rectangular parallelepiped frame structure die; a plurality of square holes (10) are separated by partitions in the frame structure of the upper die (8); a plurality of positioning plates (9) are respectively arranged at the lower part of the long side mold walls on both sides of the upper die (8); and each positioning plate (9) on the upper die (8) is provided with two positioning stoppers; The lower mold (7) is a rectangular solid mold, the upper surface of the lower mold (7) is provided with a positioning edge (11), and a plurality of positioning plates (9) are respectively provided on the mold walls of the long sides of the lower mold (7), and each positioning plate (9) on the lower mold (7) is provided with two positioning stoppers. The upper mold (8) and the lower mold (7) are molded together, and the upper mold (8) and the lower mold (7) are fastened and connected in the corresponding positioning stoppers at the upper and lower ends through a connecting piece.

2. The method for forming a large-size honeycomb sandwich structure panel with an embedded reinforcement frame according to claim 1, characterized in that The honeycomb core (6) is bonded to the reinforcement frame by means of J145 or J47D foam adhesive.

3. The method for forming a large-size honeycomb sandwich structure panel with an embedded reinforcement frame according to claim 1, characterized in that The curing is carried out at a temperature of 120° C. to 140° C. for 3 to 5 hours.

4. The method for forming a large-size honeycomb sandwich structure panel with an embedded reinforcement frame according to claim 1, characterized in that A reinforcing rib is arranged on the positioning plate (9) of the upper die (8), and a reinforcing rib is also arranged on the positioning plate (9) of the lower die (7).

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