Process method for improving quality of honeycomb block splicing seam

Abstract

The invention discloses a process method for improving the quality of a honeycomb block splicing seam. The process method comprises the following steps: S10, processing a honeycomb block; s20, processing the metal sheet; s30, forming the rubber; s40, splicing the honeycombs; s50, honeycomb positioning is carried out; s60, placing the metal sheet; s70, packaging is carried out; s80, curing is carried out; the method has the beneficial effects that stress concentration is reduced by performing variable-thickness chamfering processing on the aramid paper honeycomb block, and then uniform pressure distribution is provided in a variable-thickness area by combining the characteristics of a metal sheet and rubber, so that uniform pressurization in the curing process is ensured, and the curing quality of the aramid paper honeycomb block is improved. The problem that the polystyrene foam in the area is bulged due to the fact that honeycombs on the two sides of a splicing seam are sunken due to the fact that the polystyrene foam and the aramid paper honeycombs are inconsistent in rigidity in the honeycomb variable-thickness area of the honeycomb interlayer piece is solved.

Description

Technical Field

[0001] The invention relates to a process method for improving the quality of honeycomb block joint seams. Background Art

[0002] The honeycomb sandwich structure has the advantages of high rigidity, strong impact resistance, excellent thermal insulation, and light weight, and is widely used in the aerospace industry. The honeycomb sandwich structure is composed of upper and lower panels of prepreg and honeycomb core materials, and the core materials mainly include aramid paper honeycomb, metal aluminum honeycomb, carbon fiber honeycomb, etc. Due to the characteristics of easy processing, low cost, low thermal deformation and environmental friendliness, honeycomb sandwich structure parts usually use aramid paper honeycomb; at the same time, due to the limitation of honeycomb width, large-size honeycombs are manufactured by block splicing. Foam glue is often used as an adhesive for honeycomb splicing because of its stable mechanical properties and strong bonding ability. Since the stiffness of the foam glue and aramid paper honeycomb after honeycomb splicing is inconsistent, the paper honeycomb is prone to depression at the variable thickness splicing seam during subsequent co-gluing, which eventually leads to bulges at the splicing seam in this area. In view of this, the present invention proposes a process method for improving the quality of the splicing seam of honeycomb blocks to solve the above problems. Summary of the invention

[0003] The object of the present invention is to provide a process for improving the quality of honeycomb block joints to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A process for improving the quality of honeycomb block joints, comprising the following steps: S10. Honeycomb block processing: The three sides of the two groups of aramid paper honeycomb blocks are machined to form chamfers to form a thickened area with an angle of 5° to 30°. The side without chamfers is kept vertical in the thickness direction to form a surface to be spliced; S20. Metal sheet processing: Cut the metal sheet so that it matches the two sets of aramid paper honeycomb blocks, and embed rubber around the metal sheet; S30. Rubber molding: The joints of rubber and metal sheets are fixed with pressure-sensitive tape, packaged on metal flat plate tooling, and sent into the tank for curing and forming; S40. Honeycomb splicing: Spreading foam glue on one side of the two groups of surfaces to be spliced ​​in S10 to form a foam glue layer, and using a hot air gun to completely fill the foam glue layer into the honeycomb core of the aramid paper honeycomb block, and exceeding the height of the aramid paper honeycomb block by 0 to 3 mm, then butting the two groups of surfaces to be spliced ​​together and sending them into a tank for curing and forming; S50. Cellular positioning: Lay the lower skin panel prepreg on the surface of the forming tooling, position the aramid paper honeycomb blocks in S40 on the lower skin panel prepreg by means of a laser projector or a positioning card, and lay the skin panel prepreg on the surfaces of the two groups of aramid paper honeycomb blocks; S60. Metal sheet placement: An isolation film is laid on the upper skin panel prepreg, and the margin area around the isolation film is fixed to the molding tool by pressure-sensitive tape, and the metal sheet cured and formed in S30 is laid on the two groups of surfaces to be spliced; S70.Package: Place breathable felt on the laid metal sheet, put it down naturally without dragging or adjusting, and make a vacuum bag to wrap it to complete the vacuum packaging; S80.Curing: The vacuum-packed aramid paper honeycomb blocks and the forming tooling in S70 are sent into the tank for curing and forming, and the aramid paper honeycomb blocks are demoulded after being taken out of the tank to obtain the spliced ​​aramid paper honeycomb blocks.

[0005] As an improvement of the above technical solution, in S10, the machined aramid paper honeycomb block is dried at 120±8°C for not less than 60 minutes.

[0006] As an improvement of the above technical solution, the curing parameters in S30 are: temperature 120° C. to 180° C., full-process vacuuming -280 kPa to -650 kPa, and a heat preservation time of not less than 120 minutes.

[0007] As an improvement of the above technical solution, the curing parameters in S40 are: temperature 174° C. to 186° C., full-process vacuuming -200 kPa to -350 kPa, and a heat preservation time of not less than 120 minutes.

[0008] As an improvement of the above technical solution, the curing parameters in S80 are: temperature 120°C to 180°C, full vacuum -200kpa to -350kpa, and insulation time not less than 120min.

[0009] As an improvement of the above technical solution, in S10, the length of the metal sheet is greater than the sum of the two side edges and the top edge of the surface to be spliced, the width is 10 to 30 mm, and the thickness is 0.1 to 0.3 mm.

[0010] As an improvement of the above technical solution, in S30, the thickness of the rubber is 0.20-0.4 mm, and the gap between the rubber 20 and the metal sheet is ≤1.5 mm.

[0011] As an improvement of the above technical solution, in S60, when the metal sheet is placed, the center of the metal sheet is aligned with the seams of the two groups of surfaces to be spliced, and it is attached to the two groups of thickened areas. The metal sheet is disconnected in the area where the curvature exists, and the metal sheet is re-joined. During the joining process, the disconnected metal sheet is fixed with pressure-sensitive tape.

[0012] As an improvement of the above technical solution, in S70, the vacuum environment during vacuum packaging is -20 kPa to -40 kPa.

[0013] Compared with the prior art, the present invention has the following beneficial effects: By performing variable thickness chamfering on the aramid paper honeycomb blocks, stress concentration is reduced. Secondly, by combining the characteristics of metal sheets and rubber, uniform pressure distribution is provided in the thickened area, ensuring uniform pressurization during the curing process, and avoiding the honeycomb depression on both sides of the joint seam caused by the inconsistent stiffness of the foam glue and the aramid paper honeycomb in the honeycomb variable thickness area of ​​the honeycomb sandwich parts, which ultimately causes the foam glue in this area to bulge. In addition, precise positioning of the aramid paper honeycomb blocks and proper placement of the metal sheets, as well as the application of vacuum packaging and curing technology, ensure the uniform distribution of pressure of the entire structure during the curing process, thereby significantly improving the overall quality and performance of the honeycomb sandwich structure and achieving flatness and firmness at the joint seams. These comprehensive measures not only improve the durability and reliability of the honeycomb structure, but also optimize production efficiency and cost-effectiveness, with significant technological progress and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the metal sheet and rubber of the present invention; Figure 2 This is a schematic diagram of the structure of the aramid paper honeycomb block of the present invention; Figure 3 It is a schematic diagram of the positions of the aramid paper honeycomb block and the foaming rubber layer of the present invention; Figure 4 It is a side view of the aramid paper honeycomb block of the present invention; Figure 5 It is a schematic structural diagram of the vacuum packaging of the aramid paper honeycomb block of the present invention.

[0015] In the figure: 10, metal sheet; 20, rubber; 30, aramid paper honeycomb block; 31, thickened area; 32, surface to be spliced; 40, foam rubber layer; 50, lower skin panel prepreg; 60, molding tool; 70, upper skin panel prepreg; 71, isolation film; 80, breathable felt; 90, vacuum bag. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Example: like Figure 1-5 As shown, this embodiment proposes a process method for improving the quality of honeycomb block joints, comprising the following steps: S10. Honeycomb block processing: The three sides of the two groups of aramid paper honeycomb blocks 30 are machined to form chamfers to form a thickened area 31 with an angle of 5° to 30°. The side without chamfers is kept vertical in the thickness direction to form a surface to be spliced ​​32; S20. Metal sheet processing: Cutting the metal sheet 10 so that the metal sheet 10 matches the two groups of aramid paper honeycomb blocks 30, and embedding the rubber 20 around the metal sheet 10; S30. Rubber molding: The rubber 20 and the metal sheet 10 are fixed at the joints with a pressure-sensitive tape, and are packaged on a metal flat plate tooling, and then sent into a tank for curing and forming; S40. Honeycomb splicing: Spreading foam glue on one side of the two groups of surfaces to be spliced ​​32 in S10 to form a foam glue layer 40, and using a hot air gun to completely fill the foam glue layer 40 into the honeycomb core of the aramid paper honeycomb block 30, and exceeding the height of the aramid paper honeycomb block 30 by 0 to 3 mm, then butting the two groups of surfaces to be spliced ​​32, and sending them into a tank for curing and forming; S50. Cellular positioning: Lay the lower skin panel prepreg 50 on the surface of the forming tool 60, position the aramid paper honeycomb block 30 in S40 on the lower skin panel prepreg 50 by a laser projector or a positioning card, and lay the skin panel prepreg 70 on the surfaces of the two groups of aramid paper honeycomb blocks 30; S60. Metal sheet placement: An isolation film 71 is laid on the upper skin panel prepreg 70, and the margin area around the isolation film 71 is fixed to the molding tool 60 by a pressure-sensitive adhesive tape, and the metal sheet 10 cured and formed in S30 is laid on the thickened area 31 of the two groups of surfaces to be spliced ​​32; S70.Package: A breathable felt 80 is placed on the laid metal sheet 10, and is naturally placed without dragging or adjustment, and a vacuum bag 90 is made to wrap it, thereby completing vacuum packaging; S80.Curing: The vacuum-packed aramid paper honeycomb block 30 and the forming tool 60 in S70 are sent into a tank for curing and forming, and then demoulded after being taken out of the tank to obtain the spliced ​​aramid paper honeycomb block 30 .

[0018] In this case, when the vacuum-packed aramid paper honeycomb block 30 is fed into the tank, the auxiliary materials on the aramid paper honeycomb block 30 are fed into the tank together; When demolding, remove the auxiliary materials on the surface of the parts to obtain smooth and flat parts.

[0019] In this embodiment, the aramid paper honeycomb block 30 is subjected to variable thickness chamfering processing to reduce stress concentration. Secondly, in combination with the characteristics of the metal sheet 10 and the rubber 20, uniform pressure distribution is provided in the thickened area 31 to ensure uniform pressurization during the curing process, thereby avoiding the problem of honeycomb depression on both sides of the joint seam caused by the inconsistent stiffness of the foam glue and the aramid paper honeycomb 30 in the honeycomb variable thickness area 31 of the honeycomb sandwich, which ultimately causes the foam glue in this area to bulge. In addition, the precise positioning of the aramid paper honeycomb block 30 and the proper placement of the metal sheet 10, as well as the application of vacuum packaging and curing technology, ensure the uniform distribution of pressure of the entire structure during the curing process, thereby significantly improving the overall quality and performance of the honeycomb sandwich structure, and achieving the flatness and firmness of the joint seams. These comprehensive measures not only improve the durability and reliability of the honeycomb structure, but also optimize the production efficiency and cost-effectiveness, and have significant technical progress and application value.

[0020] Of course, in this case, the metal sheet 10 has sufficient rigidity to evenly transmit pressure in the splicing area, which helps to maintain the shape and position of the honeycomb structure during the curing process and prevent local collapse or deformation due to uneven pressure. The rubber 20 has a certain elasticity and flexibility and can adapt to different splicing surfaces and curvature changes. The rubber 20 can form a buffer around the metal sheet 10 to further ensure the uniform distribution of pressure and eliminate the indentation of the metal sheet 10 on the surface of the honeycomb sandwich parts during the curing process.

[0021] Specifically, in S10, the machined aramid paper honeycomb block 30 is dried at 120±8°C for not less than 60 minutes.

[0022] Specifically, the curing parameters in S30 are: temperature 120° C. to 180° C., full-process vacuuming -280 kPa to -650 kPa, and a heat preservation time of not less than 120 minutes.

[0023] In this embodiment, the above parameters ensure that the metal sheet 10 is slightly melted at high temperature and bonded to the rubber 20 to achieve uniform curing. The insulation time of not less than 120 minutes ensures that the adhesive has enough time to undergo sufficient chemical reaction and physical cross-linking, thereby improving the strength and durability of the bond.

[0024] Specifically, the curing parameters in S40 are: temperature 174° C. to 186° C., full-process vacuuming of -200 kPa to -350 kPa, and a heat preservation time of not less than 120 minutes.

[0025] In this embodiment, the above parameters promote the bonding between the aramid paper honeycomb block 30 and the foam glue, ensuring a strong connection during the splicing process.

[0026] Specifically, the curing parameters in S80 are: temperature 120° C. to 180° C., full-process vacuuming of -200 kPa to -350 kPa, and a heat preservation time of not less than 120 minutes.

[0027] In this embodiment, the above parameters are helpful to achieve the overall stability and structural integrity of the aramid paper honeycomb block 30 in the final curing stage. The parameters of this step may be intended to ensure complete curing and bonding between all materials including the aramid paper honeycomb block 30, the lower skin panel prepreg 50 and the upper skin panel prepreg 70. At the same time, the metal sheet 10 with rubber 20 butt-jointed on all sides transmits pressure evenly at the variable thickness joints to keep the surface of the entire structure smooth and flat.

[0028] Specifically, in S10, the length of the metal sheet 10 is greater than the sum of the two side edges and the top edge of the surface to be spliced ​​32, the width is 10-30 mm, and the thickness is 0.1-0.3 mm.

[0029] Specifically, in S30 , the thickness of the rubber 20 is 0.20-0.4 mm, and the gap between the rubber 20 and the metal sheet 10 is ≤1.5 mm.

[0030] In this embodiment, the joint gap between the metal sheet 10 and the rubber 20 is extremely small ≤1.5 mm, which helps to form an integral rigid platform so that the pressure applied during the curing process can be evenly transmitted to the entire joint area.

[0031] Specifically, in S60, when the metal sheet 10 is placed, the center of the metal sheet 10 is aligned with the seam of the two groups of surfaces to be spliced ​​32, and is attached to the two groups of thickened areas 31. The metal sheet 10 is disconnected in the area where the curvature exists, and then the metal sheet 10 is reconnected. During the connection process, the disconnected metal sheet 10 is fixed with a pressure-sensitive tape.

[0032] In this embodiment, the rejoining portion is fixed with a pressure-sensitive tape, which increases the stability of the metal sheet 10 after it is broken and ensures that the structure will not be displaced or deformed due to internal pressure or external factors during the curing process.

[0033] Specifically, in S70, the vacuum environment during vacuum packaging is -20 kPa to -40 kPa.

[0034] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for improving the quality of honeycomb block joints, characterized in that: The following steps are involved: S10. Honeycomb block processing: The three sides of the two groups of aramid paper honeycomb blocks (30) are machined to form chamfers to form a thickened area (31) with an angle of 5° to 30°, and the side without the chamfer is kept vertical in the thickness direction to form a surface to be spliced ​​(32); S20. Metal sheet processing: Cutting the metal sheet (10) so that the metal sheet (10) matches the two groups of aramid paper honeycomb blocks (30), and embedding rubber (20) around the metal sheet (10); S30. Rubber molding: The rubber (20) and the metal sheet (10) are fixed at the joints using a pressure-sensitive tape, and are packaged on a metal flat plate tooling, and are sent into a tank for curing and forming; S40. Honeycomb splicing: Spreading foam glue on one side of the two groups of surfaces to be spliced ​​(32) in S10 to form a foam glue layer (40), and using a hot air gun to completely fill the foam glue layer (40) into the honeycomb core of the aramid paper honeycomb block (30) and to extend beyond the height of the aramid paper honeycomb block (30) by 0 to 3 mm, then butting the two groups of surfaces to be spliced ​​(32) and sending them into a tank for curing and forming; S50. Cellular positioning: Laying a lower skin panel prepreg (50) on the surface of a forming tool (60), positioning the aramid paper honeycomb block (30) in S40 on the lower skin panel prepreg (50) by means of a laser projector or a positioning card, and paving the skin panel prepreg (70) on the surfaces of two groups of aramid paper honeycomb blocks (30); S60. Metal sheet placement: Laying an isolation film (71) on the upper skin panel prepreg (70), fixing the margin area around the isolation film (71) to the molding tool (60) by means of a pressure-sensitive adhesive tape, and laying the metal sheet (10) cured and molded in S30 on the thickened area (31) of the two groups of surfaces to be spliced ​​(32); S70.Package: Placing a breathable felt (80) on the laid metal sheet (10), naturally lowering it without dragging or adjusting it, and making a vacuum bag (90) to wrap it, thereby completing vacuum packaging; S80.Curing: The vacuum-sealed aramid paper honeycomb block (30) and the molding tool (60) in S70 are placed in a tank for curing and molding, and after being taken out of the tank, the aramid paper honeycomb block (30) is demoulded to obtain a spliced ​​aramid paper honeycomb block (30).

2. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: In S10, the machined aramid paper honeycomb block (30) is dried at 120±8°C for not less than 60 minutes.

3. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: The curing parameters in S30 are: temperature 120°C ~ 180°C, full vacuum -280kpa ~ -650kpa, and insulation time not less than 120min.

4. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: The curing parameters in S40 are: temperature 174°C ~ 186°C, full vacuum -200kpa ~ -350kpa, and insulation time not less than 120min.

5. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: The curing parameters in S80 are: temperature 120℃~180℃, full vacuum -200kpa~-350kpa, and insulation time not less than 120min.

6. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: In S10, the length of the metal sheet (10) is greater than the sum of the two side edges and the top edge of the surface to be spliced ​​(32), the width is 10 to 30 mm, and the thickness is 0.1 to 0.3 mm.

7. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: In S30, the thickness of the rubber (20) is 0.20-0.4 mm, and the gap between the rubber (20) and the metal sheet (10) is ≤1.5 mm.

8. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: In S60, when the metal sheet (10) is placed, the center of the metal sheet (10) is aligned with the joints of the two sets of surfaces to be spliced ​​(32), and is attached to the two sets of thickened areas (31). The metal sheet (10) is disconnected in the area where the curvature exists, and then the metal sheet (10) is reconnected. During the connection process, the disconnected metal sheet (10) is fixed using a pressure-sensitive tape.

9. A process for improving the quality of honeycomb block joints according to claim 1, characterized in that: In S70, the vacuum environment during vacuum packaging is -20 kPa to -40 kPa.

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