A method of forming a honeycomb sandwich assembly and the assembly

Abstract

The application relates to the technical field of aerospace materials, in particular to a forming method of a honeycomb sandwich assembly and the assembly, which comprises an isolation plate, a sealing rubber strip and a rod, the rod is matched with the shape of a core grid on a honeycomb core, the sealing rubber strip is used for sealing a to-be-potted position on the honeycomb core, the sealing rubber strip is communicated with at least one vacuum nozzle, the isolation plate is provided with air permeation holes communicated with the bottom of the core grid at the to-be-potted position, and the bottom of the isolation plate is transversely provided with exhaust gaps communicated with the air permeation holes and the inner side of the sealing rubber strip; the application realizes the homodirection of the exhaust path and the filling power in the potting process, solves the bubble retention problem, significantly improves the compactness and uniformity of the potting, and eliminates the defects of the decrease of structural strength and fatigue life caused by the potting bubbles.

Description

Technical Field

[0001] This invention relates to the field of aerospace materials technology, and in particular to a method for forming a honeycomb sandwich assembly and the assembly itself. Background Technology

[0002] With the increasing performance requirements of aerospace vehicles, the configurations of honeycomb sandwich structures are becoming increasingly complex. Both honeycomb and composite materials possess high specific strength, and honeycomb sandwich structures formed by honeycomb and composite materials have been widely used in the aerospace field. The honeycomb core splicing method mainly involves using a honeycomb as the center, splicing composite materials and honeycomb with the honeycomb using an adhesive, and then curing it at high temperature to form a new whole. Using this whole as the center, it is then spliced ​​with composite material components and honeycomb again using adhesive to form a new whole, and this cycle is repeated to complete the splicing of honeycomb and composite materials.

[0003] Chinese patent document with application number 201110151156.6 discloses a pre-filling molding tooling and process method for honeycomb sandwich components. The method involves placing a honeycomb on a mold, connecting the mold and the honeycomb core through positioning pins, placing baffles around the honeycomb, placing a filling template on the honeycomb, placing the filling adhesive on the honeycomb, placing a pressure plate on the filling adhesive, and using a vacuum bag to draw vacuum, filling the honeycomb cells with the filling adhesive through the pressure plate.

[0004] However, although this scheme utilizes vacuum bags to apply overall pressure, it still suffers from poor gas expulsion within the honeycomb lattice, causing air bubbles to easily become trapped in the potting compound and form potting bubbles. This severely affects the structural strength and reliability. The defect problem of air bubble formation within the honeycomb core lattice has not been fundamentally solved, seriously impacting the structural strength and fatigue life. Specifically, this is caused by the following structural defects: 1. The existing process is a top-down injection method. The bottom of the honeycomb cell is tightly attached to the mold to form a closed or semi-closed space. When the high-viscosity adhesive is injected, it acts like a viscous piston pressing down, forcing the air at the bottom to be expelled upwards. However, the upward venting path is quickly blocked by the subsequent flow of adhesive itself, causing the air to be compressed and trapped at the bottom of the cell or inside the adhesive, unable to be expelled smoothly.

[0005] 2. From a fluid dynamics perspective, the natural escape direction of air and the forced filling direction of the adhesive are completely opposite in the same narrow channel, forming direct competition. While the external vacuum pressure drives the adhesive to fill downwards, it actually exacerbates the blocking effect on the exhaust port above, making it more difficult for gas to escape.

[0006] 3. The negative pressure generated by the vacuum bag acts on the macroscopic surface of the workpiece. For bubbles that are trapped deep in the microscopic core and are encased in viscous adhesive, this macroscopic pressure is difficult to effectively penetrate the liquid medium and expel them. The removal of bubbles can only rely on extremely slow molecular diffusion, which cannot be completed before the adhesive solidifies. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a molding method and assembly for a honeycomb sandwich component. This method achieves the alignment of the venting path and filling force during the potting process, solves the problem of air bubble retention, significantly improves the density and uniformity of the potting, and eliminates the defects of reduced structural strength and fatigue life caused by potting air bubbles.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a method for molding a honeycomb sandwich assembly, comprising the following steps: S1. Use a template to mark the areas of the honeycomb core that need to be filled, and use paper tape to isolate the non-filled areas. S2. Place the honeycomb core on the isolation plate with vents. Seal the surface of the isolation plate with sealing strips. The inner end of the vent is connected to the bottom of the core cell in the position to be filled on the honeycomb core, and the outer end of the vent is connected to the internal space of the sealing strip. S3. Fill the core cell with adhesive and use rods that are compatible with the honeycomb core to help compact the core cell. The pre-extraction space is formed by the inner side of the sealing strip, the bottom space of the core cell filled with adhesive, the bottom of the honeycomb core and the bottom surface of the partition plate, so that there is an air vent gap between the bottom of the partition plate and the sealing strip. S4. Vacuum the pre-extraction space to allow the adhesive to fill the bottom of the cell under negative pressure, while simultaneously ensuring that the pre-extraction space is at a preset vacuum level, and then cure the honeycomb core.

[0009] Before step S1, the honeycomb core is installed in the milling mold, and the honeycomb core and the milling mold are placed together in a freezer for refrigeration at a specified temperature for at least 24 hours. Then, the honeycomb core is taken out of the freezer and its shape is processed.

[0010] This includes a molding base, which has a first laying outline corresponding to the lower panel, and a reference positioning hole. After step S4, it further includes: S5. Take out the lower panel, check the projection line of the lower panel with the first laying outline line to ensure that the projection line of the lower panel corresponds accurately with the first laying outline line, and lay the lower panel on the forming fixture along the first laying outline line. S6. Use auxiliary materials to perform a vacuum leak check on the lower panel, and cure the lower panel in a hot autoclave. After curing, remove the auxiliary materials from the lower panel and make a first positioning hole, which corresponds to the reference positioning hole.

[0011] The process includes, after step S6: S7. Align the first positioning hole with the reference positioning hole, lay the lower panel on the molding base, and lay the core adhesive film wrapped with a non-porous release film on the surface of the lower panel.

[0012] Step S7 further includes: The filled and cured honeycomb core is placed on the bottom plate, and limiting blocks are installed around the molding base to achieve the shape calibration of the bottom plate and the honeycomb core. Then, a conformal composite pressure plate is placed on the upper surface of the honeycomb core. The composite pressure plate is made of flexible material, and vacuum sealing is performed using auxiliary materials. It is then cured in an autoclave. Under vacuum and autoclave pressure, the composite pressure plate conforms to the honeycomb contour, avoiding gaps in the frame and effectively preventing the bag from breaking.

[0013] In step S7, the honeycomb core is placed on the bottom plate by adhesive bonding, and the process also includes: The upper surface of the honeycomb core is laid with a lower adhesive film. After the laying is completed, a pre-vacuum is performed. The outline of the honeycomb core and the outline of the lower panel are accurately placed according to the projection relationship. Then, vacuum sealing and curing are performed. After cooling, the auxiliary materials are removed.

[0014] This also includes a hole-making mold, which has a hole-making positioning hole corresponding to the first positioning hole and a cavity adapted to the honeycomb core. After step S7, it further includes: S8. Flip the lower panel and the honeycomb core so that the honeycomb core fits into the cavity, so that the first positioning hole on the lower panel and the hole-making mold accurately corresponds to the hole-making positioning hole. First, based on the position of the honeycomb core and the size requirements of the hole position, compile the hole-making position and program that meet the requirements, conduct simulation trial run, and after the trial run meets the requirements, perform CNC hole making. When making holes using CNC machining, the hole-making tool passes through the lower panel and the honeycomb core from top to bottom. Excess material and residue in the hole are left inside the cavity, and excess residue in the honeycomb core also flows into the cavity.

[0015] This also includes a layup base, which has a second layup outline corresponding to the honeycomb core outline. After step S8, it further includes: S9. Place the cured lower panel and honeycomb core on the stacking base according to the second laying outline, so that the lower panel is below the honeycomb core. Accurately lay the adhesive film and upper panel on the surface of the honeycomb core according to the projection of the second laying outline. Place auxiliary materials to perform a vacuum leak test on the lower panel, honeycomb core and upper panel as a whole, and cure them in a hot autoclave. Then, the auxiliary materials are removed, and the top panel is drilled and its shape is inspected to ensure that the product outline after drilling meets the measurement standards.

[0016] The folding base is also provided with a finished product outline, which is located inside the second folding outline line. The lower panel, honeycomb core and upper panel after folding are all cut according to the finished product outline to ensure that the size of the finished product meets the preset value.

[0017] The present invention also provides a molding component, including a separator plate, a sealing strip, and a rod. The rod is adapted to the shape of the core cell on the honeycomb core. The sealing strip is used to seal the position to be filled on the honeycomb core. The sealing strip is connected to at least one vacuum nozzle. The separator plate is provided with a vent hole communicating with the bottom of the core cell at the position to be filled. The bottom of the separator plate is provided with a horizontally arranged exhaust gap communicating with the vent hole and the inner side of the sealing strip. The beneficial effects of this invention are: This molding method alters the filling force direction and gas discharge path of the potting compound. Compared to the traditional top-down filling and upward gas discharge method, which involves opposing directions and easily leads to gas stagnation, this solution, through the vent holes on the isolation plate and the establishment of a pre-evacuation space, places the vacuum extraction port on the same side as the downward direction of the compound filling, corresponding to the bottom of the core. When vacuum extraction is required, the negative pressure acts directly on the bottom of the core and below the compound.

[0018] Therefore, under the action of negative pressure, a downward pulling effect is generated on the adhesive. On the one hand, the negative pressure serves as the main driving force, pulling the adhesive downward to fully fill every corner of the core cell. On the other hand, the air at the bottom of the core cell and the air bubbles trapped in the adhesive naturally escape in the same direction as the direction of the negative pressure and the direction of the adhesive flow, all flowing downward. This allows the gas to be smoothly drawn into the pre-evacuation space through the vent holes and then extracted by the vacuum system through the exhaust gap. Combined with the auxiliary compaction of the rod as a preliminary mechanical extrusion, this works synergistically with the subsequent vacuum pull-down to further ensure the compaction of the adhesive.

[0019] This achieves the alignment of the venting path and filling power during the potting process, completely solving the problem of air bubble retention caused by the opposing competition between gas and liquid flow in traditional methods. It significantly improves the density and uniformity of the potting, and eliminates the defects of reduced structural strength and fatigue life caused by potting air bubbles. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the molded component.

[0021] Figure 2 This is a three-dimensional structural diagram of a milling die.

[0022] Figure 3 This is a schematic diagram of the honeycomb core structure.

[0023] Figure 4 This is an exploded view of the three-dimensional structure of the molded base.

[0024] Figure 5 This is a three-dimensional structural diagram of a hole-making mold.

[0025] Figure 6 This is a schematic diagram of the three-dimensional structure of the folded base.

[0026] Figure 7 This is a structural diagram showing a base with a second laying outline and a finished product outline.

[0027] 01. Honeycomb core; 02. Lower panel; 021. First positioning hole; 03. Upper panel; 1. Molding components; 11. Isolation plate; 1101. Vent hole; 1102. Exhaust gap; 12. Sealing strip; 1201. Vacuum nozzle; 13. Rod stock; 2. Milling molds; 3. Molding base; 31. Limiting block; 3101. Reference positioning hole; 4. Composite material uniformly pressed board; 5. Hole-making mold; 5101. Cavity; 5102. Hole-making positioning hole; 6. Lay out the base; 6101. Lay out the outline for the second time; 6102. Finished outline. Detailed Implementation

[0028] To facilitate understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments and accompanying drawings. Specific embodiments of the present invention will be described below. It should be noted that, in order to provide a concise description of these embodiments, this specification cannot provide a detailed description of all features of the actual embodiments.

[0029] refer to Figures 1 to 7 As shown, the present invention provides a method for molding a honeycomb sandwich assembly, comprising the following steps: S1. Use the template to mark the locations where the honeycomb core 01 needs to be potted, and use paper tape to isolate the non-potted locations.

[0030] S2. Place the honeycomb core 01 on the isolation plate 11 with vent holes 1101. The surface of the isolation plate 11 is sealed with a sealing strip 12. The inner end of the vent hole 1101 is connected to the bottom of the core cell in the position to be filled on the honeycomb core 01, and the outer end of the vent hole 1101 is connected to the internal space of the sealing strip 12.

[0031] S3. Fill the core cell with adhesive and use a rod 13 that is compatible with the honeycomb core 01 to help compact the core cell. The pre-evacuation space is formed by the inner side of the sealing strip 12, the bottom space of the core cell filled with adhesive, the bottom of the honeycomb core 01 and the bottom surface of the isolation plate 11, so that there is an exhaust gap 1102 between the bottom of the isolation plate 11 and the sealing strip 12, ensuring that the pre-evacuation space is connected to the external vacuum system.

[0032] S4. Vacuum the pre-extraction space to allow the adhesive to fill the bottom of the core cell under negative pressure, while simultaneously ensuring that the pre-extraction space is at a preset vacuum level, and then cure the honeycomb core 01.

[0033] refer to Figures 1 to 3 As shown in the figure, in summary, this molding method changes the filling force direction of the potting compound and the gas discharge path. Compared with the traditional process of top-down filling and upward gas discharge, which makes the two directions opposite and prone to gas retention, this solution, through the vent holes 1101 on the isolation plate 11 and the establishment of the pre-evacuation space, sets the vacuum extraction port on the same side of the downward direction of the compound filling, that is, at the bottom of the core cell. When vacuum extraction is required, the negative pressure acts directly on the bottom of the core cell and below the compound.

[0034] refer to Figure 1 As shown, under the action of negative pressure, a downward pulling effect is generated on the adhesive. On the one hand, the negative pressure serves as the main driving force, pulling the adhesive downward to fully fill every corner of the core. On the other hand, the air at the bottom of the core and the air bubbles trapped in the adhesive naturally escape in the same direction as the direction of the negative pressure and the direction of the adhesive flow, both flowing downward. This allows the gas to be smoothly drawn into the pre-evacuation space through the vent 1101 and then extracted by the vacuum system through the exhaust gap 1102. Combined with the auxiliary compaction of the rod 13 as a preliminary mechanical extrusion, it works synergistically with the subsequent vacuum pull-down to further ensure the compactness of the adhesive.

[0035] This achieves the alignment of the venting path and filling power during the potting process, completely solving the problem of air bubble retention caused by the opposing competition between gas and liquid flow in traditional methods. It significantly improves the density and uniformity of the potting, and eliminates the defects of reduced structural strength and fatigue life caused by potting air bubbles.

[0036] refer to Figure 1 , 2As shown, in this embodiment, before step S1, the honeycomb core 01 is installed in the milling mold 2, and the honeycomb core 01 and the milling mold 2 are placed together in a freezer for refrigeration at a specified refrigeration temperature for at least 24 hours. Then, it is taken out of the freezer and the shape of the honeycomb core 01 is processed.

[0037] In practical applications, the honeycomb core 01 material is relatively soft and lacks rigidity at room temperature. Directly milling or other machining operations can easily lead to collapse, deformation, or burrs. By setting up a machining method that involves first chilling the material before milling, the hardness and rigidity of the honeycomb core 01 material can be temporarily and significantly improved. Furthermore, high-speed milling in this state, using a sharp aluminum carbide end mill as the cutting tool, can cut the material more cleanly, reducing plastic deformation and fiber / foil stretching. This results in a dimensionally accurate shape with neat boundaries. By strictly controlling the chilling time (≥24h), the overall temperature of the honeycomb core 01 material is ensured to drop to the process requirements and reach the optimal processing state. This solves the problem of easy damage during machining of the honeycomb core 01, thus obtaining a high-precision, high-quality outline, laying a reliable foundation for subsequent precise potting and assembly.

[0038] refer to Figure 1 , 3 As shown, in this embodiment, a molding base 3 is included. The molding base 3 is provided with a first laying outline corresponding to the lower panel 02. The molding base 3 is provided with a reference positioning hole 3101. After step S4, the following is also included: In practical application, S5, take out the pre-prepared lower panel 02, carefully check and align the projection lines of the lower panel 02 edge with the first laying contour line to ensure that the projection lines of the lower panel 02 correspond accurately with the first laying contour line, and lay the lower panel 02 along the first laying contour line on the forming fixture; S6, use vacuum bag film and other auxiliary materials to seal the lower panel 02 and perform a vacuum leakage check. After confirming that the seal is intact, send it into a hot autoclave and cure it under hot pressure. After curing, remove the auxiliary materials from the lower panel 02 and make the first positioning hole 021, which corresponds to the reference positioning hole 3101; by using the forming base 3 as the reference fixture for forming the lower panel 02, the first laying contour line on it provides the panel laying. The precise spatial positioning guidance ensures the accurate initial positioning of the lower panel 02. The final shape and mechanical properties of the lower panel 02 are given by the autoclave curing process. The first positioning hole 021, which is made after curing, is located from the reference positioning hole 3101 on the base. This is equivalent to accurately corresponding the reference coordinate system on the molding base 3 with the reference coordinate system of the lower panel 02, establishing a unified and precise positioning reference that runs through all subsequent assembly stages. This realizes the precise forming and reference transfer of the composite material lower panel 02, and provides a crucial positioning basis for the subsequent accurate assembly of components such as the honeycomb core 01 and the upper panel 03 onto the lower panel 02. This solves the problem of excessive cumulative error and inaccurate alignment in large or complex sandwich structures.

[0039] refer to Figure 3 , 4 As shown, in this embodiment, after step S6, the method further includes: S7, accurately aligning the first positioning hole 021 with the reference positioning hole 3101, laying the lower panel 02 on the molding base 3, and laying a core adhesive film wrapped with a non-porous isolation film on the surface of the lower panel 02.

[0040] In practical applications, the lower panel 02 is precisely reset onto the molding base 3 through the first positioning hole 021, restoring its reference position during molding in steps S5-S6. The core adhesive film subsequently laid is an adhesive layer used to connect the lower panel 02 and the honeycomb core 01. The use of a non-porous release film for wrapping prevents foreign matter from adhering to the film in advance or causing displacement during subsequent operations, while also facilitating operation and positioning. When the honeycomb core 01 is subsequently placed and hot-pressed, the non-porous release film is pulled out or melted, allowing the adhesive film to function and ensuring that the adhesive material is precisely and cleanly pre-placed at the predetermined bonding interface, thus preparing for a high-strength, defect-free bond between the panel and the core material.

[0041] refer to Figure 3 , 4As shown, in this embodiment, step S7 further includes: placing the filled and cured honeycomb core 01 on the lower panel 02, and installing limiting blocks 31 around the molding base 3 to achieve the shape calibration of the lower panel 02 and the honeycomb core 01. The limiting blocks 31 play a role in mechanically positioning and clamping the component before the vacuum pressure is applied, preventing it from shifting in subsequent processing.

[0042] Then, a conformal composite pressure equalizing plate 4 is placed on the upper surface of the honeycomb core 01. The composite pressure equalizing plate 4 is made of flexible material, vacuum-sealed with auxiliary materials, and cured in a thermostatic precipitator. Under vacuum and thermostatic pressure, the composite pressure equalizing plate 4 conforms to the honeycomb contour, avoiding gaps and effectively preventing bag breakage. Specifically, because the composite pressure equalizing plate 4 is flexible, it can adaptively conform to the undulating contour of the upper surface of the honeycomb core 01 under pressure, that is, to the edge of each core cell, thereby uniformly transmitting pressure to the entire top surface of the honeycomb core 01. This avoids local stress concentration or "bridging" at the corners of the honeycomb cells, forming gaps. The uniform pressure ensures that the core adhesive film is uniformly compacted, and the adhesive interface is dense. At the same time, it effectively prevents the hard corners of the honeycomb cells from puncturing the vacuum bag film above under pressure. This solves the process problems of uneven pressure transmission and easy bag breakage during the adhesive curing of honeycomb sandwich structures, ensuring the uniformity and reliability of the adhesive quality.

[0043] refer to Figure 3 , 4 As shown, in this embodiment, in step S7, the honeycomb core 01 is placed on the lower panel 02 by adhesive bonding, and the method further includes: In practical applications, a special adhesive film is used to cover the entire lower surface of the honeycomb core 01. After the film is laid, a brief pre-vacuum is performed to initially remove the air between the adhesive film and the honeycomb core 01, so that it can be initially bonded and stabilized. Then, the honeycomb core 01, together with the adhesive film on its lower surface, is precisely placed on the lower panel 02 according to the projection relationship between its outline and the outline of the lower panel 02. Finally, it is vacuum sealed and sent to an autoclave for curing. After cooling, all auxiliary materials are removed.

[0044] The pre-lamination of the adhesive film provides a quantitative and uniform amount of adhesive for bonding. A pre-vacuuming step removes most of the interfacial air, preventing bonding defects caused by air expansion or retention during curing. Subsequently, the honeycomb core 01 is precisely placed according to the projection relationship, ensuring a perfect fit with the designed position of the lower panel 02. During autoclave curing, heat melts, flows, and wets the adhesive film onto the bonding surface, while pressure fully compacts it and expels residual trace gases, ultimately achieving a high-strength, high-reliability structural bond. This optimizes the bonding process window between the honeycomb core 01 and the panel, solving quality problems such as porosity and delamination at the bonding interface, thus significantly improving the interfacial strength and durability of the sandwich structure.

[0045] refer to Figure 3 , 4 As shown in Figure 5, this embodiment also includes a hole-making mold 5. The hole-making mold 5 is provided with a hole-making positioning hole 5102 corresponding to the first positioning hole 021 and a cavity 5101 adapted to the honeycomb core 01. After step S7, the embodiment further includes: S8, flipping the lower panel 02 and the honeycomb core 01 so that the honeycomb core 01 is fitted into the cavity 5101 so that the first positioning hole 021 on the lower panel 02 and the hole-making mold 5 accurately corresponds to the hole-making positioning hole 5102. First, according to the position of the honeycomb core 01 and the hole position size requirements, a hole-making position and program that meet the requirements are compiled and a simulation test run is performed. After the test run meets the requirements, the holes are numerically controlled.

[0046] When making holes using CNC machining, the drilling tool passes through the lower panel 02 and the honeycomb core 01 from top to bottom. Excess material and residue in the hole are left inside the cavity 5101. Excess residue in the honeycomb core 01 also flows into the cavity 5101. This causes the chips, residues and other excess material generated by cutting to fall naturally downwards under the action of gravity and remain inside the cavity 5101 of the drilling mold 5, instead of remaining in the core of the honeycomb core 01.

[0047] refer to Figure 3 , 5 As shown, in practical applications, by flipping the mold, the honeycomb core 01 area that needs to be perforated is suspended above the mold cavity 5101, providing space for chip removal. The perforation mold 5 ensures the absolute positional accuracy of the part during processing through the positioning hole system, changing the perforation sequence and chip removal direction. Compared with the traditional process of perforating after both skins are glued, this solution perforates only after the lower panel 02 is glued, and processes from the lower panel 02 side to the honeycomb core 01 side. Under the combined action of drilling force and gravity, the chips fall completely into the open cavity 5101 below, achieving source isolation and automatic collection of foreign matter. This solves the industry problem of foreign matter remaining inside the honeycomb sandwich structure after perforation, avoiding abnormal noise, wear or functional failure caused by foreign matter due to vibration and impact, and greatly improving the reliability and lifespan of the product.

[0048] refer to Figure 6 , 7 As shown, in this embodiment, a layup base 6 is also included. The layup base 6 is provided with a second layup outline 6101 corresponding to the outline of the honeycomb core 01. After step S8, the following is also included: refer to Figure 7As shown in step S9, the cured lower panel 02 and honeycomb core 01 are placed on the stacking base 6 according to the second laying outline 6101, so that the lower panel 02 is below the honeycomb core 01. The adhesive film and upper panel 03 are accurately laid on the surface of the honeycomb core 01 according to the projection of the second laying outline 6101. Auxiliary materials are placed to perform a vacuum leak check on the lower panel 02, honeycomb core 01, and upper panel 03 as a whole, and then cured in a hot autoclave. Then the auxiliary materials are removed, and the upper panel 03 is drilled and its shape is inspected to ensure that the product outline after drilling meets the measurement standards.

[0049] refer to Figure 3 , 6 As shown in Figure 7, in practical applications, the set stacking base 6 and the second laying outline 6101 provide a precise positioning reference for the final stage of panel assembly. The upper panel 03 ensures precise alignment with the components below through projection stacking. Through the subsequent autoclave curing process, the adhesive film melts and flows, firmly bonding the upper panel 03 and the honeycomb core 01 into one, ultimately forming a complete "lower panel 02-honeycomb core 01-upper panel 03" sandwich structure. After final testing, the product is ensured to meet all size and shape requirements, completing the final integrated manufacturing of the honeycomb sandwich structure. Through strict step-by-step positioning and overall curing, the accuracy of the final product form and the structural integrity are guaranteed.

[0050] refer to Figure 6 , 7 As shown, in this embodiment, the stacking base 6 is also provided with a finished product outline 6102. The finished product outline 6102 is located inside the second laying outline line 6101. The lower panel 02, honeycomb core 01 and upper panel 03 are all cut according to the finished product outline 6102 to ensure that the size of the finished product meets the preset value.

[0051] In practical applications, in addition to the second laying outline 6101, the final finished outline 6102 is also engraved on the laying base 6. Since the finished outline 6102 is located inside the second laying outline 6101, and the two maintain a fixed offset distance, such as 5-15mm, after the overall curing is completed in step S9, the edges of the lower panel 02, the honeycomb core 01 and the upper panel 03 are all uniformly cut according to the finished outline 6102.

[0052] The second laying outline 6101 serves as the process boundary line during the laying and assembly process, providing necessary operational margins and safety boundaries for material laying, honeycomb placement, and other operations, preventing insufficient material in the effective area due to minor alignment deviations or natural extension during material laying. The finished product outline 6102 line is used to determine the final design boundary of the product. After all internal connections and functional structure manufacturing are completed, such as the potting area and positioning holes, the outer process margins are removed by one-time cutting to directly obtain the final product with precise dimensions. This ensures both operability and tolerance in the manufacturing process, as well as the accuracy and consistency of the final product dimensions, solving the problem of out-of-tolerance final products caused by accumulated errors or processing losses during the manufacturing process of complex components.

[0053] refer to Figure 1 As shown, the present invention also provides a molding component, including a partition plate 11, a sealing strip 12, and a rod 13. The rod 13 is adapted to the shape of the core cell on the honeycomb core 01. The sealing strip 12 is used to seal the position to be filled on the honeycomb core 01. The sealing strip 12 is connected to at least one vacuum nozzle 1201. The partition plate 11 is provided with a vent hole 1101 communicating with the bottom of the core cell at the position to be filled. The bottom of the partition plate 11 is provided with an exhaust gap 1102 communicating with the vent hole 1101 and the inner side of the sealing strip 12.

[0054] In practical applications, the rod 13 is hexagonal in shape to match the shape of the core cells on the honeycomb core 01, thereby assisting in compacting the adhesive filling the core cells; the sealing strip 12 is used to seal the area to be filled on the honeycomb core 01, forming a closed sealing area, and at least one vacuum nozzle 1201 is connected to the sealing strip 12 for connecting to an external vacuum system; the isolation plate 11 is provided with several vent holes 1101, the positions of which correspond one-to-one or in groups to the bottom of the core cells in the area to be filled, ensuring that the bottom of each core cell to be filled has an exhaust channel; in addition, the bottom of the isolation plate 11 is designed with a horizontally extending groove, thereby forming an exhaust gap 1102 that communicates with all the vent holes 1101 and the inner area of ​​the sealing strip 12.

[0055] Specifically, during the vacuum potting process, the vacuum nozzle 1201 is connected to an external vacuum generator to smoothly generate negative pressure. When negative pressure is applied through the vacuum nozzle 1201, the negative pressure suction force of the vacuum acts directly on the bottom space of each core cell to be potted through the exhaust gap 1102 and the vent 1101. This negative pressure environment produces two core functions: First, as a powerful force, it actively pulls the adhesive from above downwards to fill the core cell, allowing it to overcome viscous resistance and flow into the bottom and corners of the core cell; Second, it provides a clear, smooth, and consistent downward discharge path for the air and air bubbles that may be trapped in the adhesive at the bottom of the core cell, allowing the gas to be quickly removed. The exhaust gap 1102 ensures the uniformity of air extraction from each vent 1101, avoiding local blockage.

[0056] In summary, the molding component 1 not only satisfies the filling of the core lattice adhesive at the potting position, but also physically realizes the process layout of the vacuum vent located below the potting surface. This supports the core principles of "pull-down" potting and "co-directional venting" in the aforementioned method, providing a direct and effective tool guarantee for solving the problem of air bubbles in the potting process.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present invention without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A method for molding a honeycomb sandwich component, characterized in that, Includes the following steps: S1. Use a template to mark the locations in the honeycomb core (01) that need to be filled, and use paper tape to isolate the non-filled locations; S2. Place the honeycomb core (01) on the isolation plate (11) with vent holes (1101). The surface of the isolation plate (11) is sealed with a sealing strip (12). The inner end of the vent hole (1101) is connected to the bottom of the core cell in the position to be filled on the honeycomb core (01), and the outer end of the vent hole (1101) is connected to the internal space of the sealing strip (12). S3. Fill the core cell with adhesive and use a rod (13) that is compatible with the honeycomb core (01) to help compact the core cell. The pre-extraction space is formed by the inner side of the sealing strip (12), the bottom space of the core cell filled with adhesive, the bottom of the honeycomb core (01) and the bottom surface of the isolation plate (11), so that there is an exhaust gap (1102) between the bottom of the isolation plate (11) and the sealing strip (12). S4. Vacuum extraction is performed on the pre-extraction space so that the adhesive is filled into the bottom of the core cell under negative pressure. At the same time, the pre-extraction space is kept at the preset vacuum level. Then the honeycomb core (01) is cured.

2. The molding method of the honeycomb sandwich assembly according to claim 1, characterized in that, Before step S1, the honeycomb core (01) is installed in the milling mold (2), and the honeycomb core (01) and the milling mold (2) are placed together in the freezer for refrigeration at the specified refrigeration temperature for at least 24 hours. Then, the honeycomb core (01) is taken out of the freezer and its shape is processed.

3. The molding method of the honeycomb sandwich assembly according to claim 1, characterized in that, The system includes a molding base (3), which has a first laying outline corresponding to the lower panel (02) and a reference positioning hole (3101). After step S4, the system further includes: S5. Take out the lower panel (02), check the projection line of the lower panel (02) against the first laying outline line to ensure that the projection line of the lower panel (02) corresponds accurately to the first laying outline line, and lay the lower panel (02) along the first laying outline line on the forming fixture. S6. Use auxiliary materials to perform vacuum leakage inspection on the lower panel (02) and cure the lower panel (02) in a hot autoclave. After curing, remove the auxiliary materials from the lower panel (02) and make a first positioning hole (021). The first positioning hole (021) corresponds to the reference positioning hole (3101).

4. The molding method of the honeycomb sandwich assembly according to claim 3, characterized in that, Following step S6, the following is also included: S7. Accurately align the first positioning hole (021) with the reference positioning hole (3101), lay the lower panel (02) on the molding base (3), and lay the core adhesive film wrapped with a non-porous isolation film on the surface of the lower panel (02).

5. The molding method of the honeycomb sandwich assembly according to claim 4, characterized in that, Step S7 further includes: The filled and cured honeycomb core (01) is placed on the lower panel (02), and limiting blocks (31) are installed around the molding base (3) to achieve the shape calibration of the lower panel (02) and the honeycomb core (01); Then, a conformal composite pressure plate (4) is placed on the upper surface of the honeycomb core (01). The composite pressure plate (4) is made of flexible material, vacuum-sealed with auxiliary materials, and cured in a thermostatic precipitator. Under vacuum and thermostatic pressure, the composite pressure plate (4) fits the honeycomb contour, avoiding gaps in the frame space and effectively preventing the bag from breaking.

6. The method for forming a honeycomb sandwich assembly according to claim 5, characterized in that, In step S7, the honeycomb core (01) is placed on the lower panel (02) by adhesive bonding, and the process also includes: The upper surface of the honeycomb core (01) is laminated with a lower adhesive film. After the lamination is completed, a pre-vacuum is performed. The outline of the honeycomb core (01) and the outline of the lower panel (02) are accurately placed according to the projection relationship. Then, vacuum sealing and curing are performed. After cooling, the auxiliary materials are removed.

7. The method for forming a honeycomb sandwich assembly according to claim 5, characterized in that, It also includes a hole-making mold (5), which is provided with a hole-making positioning hole (5102) corresponding to the first positioning hole (021) and a cavity (5101) adapted to the honeycomb core (01). After step S7, it also includes: S8. Flip the lower panel (02) and the honeycomb core (01) so that the honeycomb core (01) fits into the cavity (5101) so that the first positioning hole (021) on the lower panel (02) and the hole-making mold (5) accurately corresponds to the hole-making positioning hole (5102). First, based on the position of the honeycomb core (01) and the hole position size requirements, compile the hole-making position and program that meet the requirements, conduct simulation trial run, and after the trial run meets the requirements, perform CNC hole making. When making holes, the hole-making tool passes through the lower panel (02) and the honeycomb core (01) from top to bottom. Excess material and residue in the hole are left inside the cavity (5101), and excess residue in the honeycomb core (01) also flows into the cavity (5101).

8. The method for forming a honeycomb sandwich assembly according to claim 7, characterized in that, It also includes a layup base (6), which is provided with a second layup outline (6101) corresponding to the outline of the honeycomb core (01). After step S8, it further includes: S9. Place the cured lower panel (02) and honeycomb core (01) on the stacking base (6) according to the second laying outline (6101), so that the lower panel (02) is below the honeycomb core (01). Accurately lay the adhesive film and upper panel (03) on the surface of the honeycomb core (01) according to the projection of the second laying outline (6101). Place auxiliary materials to perform a vacuum leak check on the lower panel (02), honeycomb core (01) and upper panel (03), and cure them in a hot autoclave. Then remove the auxiliary materials and perform hole making and shape inspection on the upper panel (03) to ensure that the product outline after hole making meets the measurement standards.

9. The method for forming a honeycomb sandwich assembly according to claim 8, characterized in that, The stacking base (6) is also provided with a finished product outline (6102), which is located inside the second laying outline line (6101). The lower panel (02), honeycomb core (01) and upper panel (03) after the process are all cut according to the finished product outline (6102) to ensure that the size of the finished product meets the preset value.

10. A molding component for molding a honeycomb sandwich component according to any one of claims 1 to 9, characterized in that, The device includes a partition plate (11), a sealing strip (12), and a rod (13). The rod (13) is adapted to the shape of the core cell on the honeycomb core (01). The sealing strip (12) is used to seal the position to be filled on the honeycomb core (01). The sealing strip (12) is connected to at least one vacuum nozzle (1201). The partition plate (11) is provided with a vent hole (1101) that communicates with the bottom of the core cell at the position to be filled. The bottom of the partition plate (11) is provided with an exhaust gap (1102) that communicates with the vent hole (1101) and the inner side of the sealing strip (12).

Images