Basalt fiber cotton honeycomb core, honeycomb structure and filling method thereof

Abstract

The present application relates to the technical field of honeycomb structure, and particularly relates to a basalt fiber cotton honeycomb core, a honeycomb structure and a filling method thereof. The honeycomb core is filled with basalt fiber cotton. The filling method comprises the following steps: performing dehydration and drying treatment on the basalt fiber cotton; injecting liquid tert-butyl alcohol into the dehydrated and dried basalt fiber cotton to make it coagulate and solidify; cutting the solidified basalt fiber cotton into a regular hexagonal column which is consistent with the size of the inner cavity of the honeycomb core, the height of the core and the arrangement direction; filling the regular hexagonal column into the honeycomb core and making it adhere to the inner cavity of the honeycomb core; performing vacuum freeze drying on the honeycomb core filled with the basalt fiber cotton to obtain a basalt fiber cotton honeycomb structure. The basalt fiber cotton honeycomb core, the honeycomb structure and the filling method thereof aim to solve the problems of poor mechanical structure strength and corrosion resistance and insufficient low-frequency noise reduction capacity of the existing sound-absorbing honeycomb.

Description

Technical Field

[0001] This invention relates to the field of honeycomb structure technology, specifically to a basalt fiber cotton honeycomb core, honeycomb structure and its filling method. Background Technology

[0002] Metal honeycomb noise reduction structures are composed of perforated panels, a honeycomb core, and non-perforated panels, bonded or welded together. They offer advantages such as lightweight, noise reduction, and high specific strength. Based on the Helmholtz resonance effect, metal honeycomb noise reduction converts sound energy into heat energy through a resonant system formed by the honeycomb structure. This method is simple to operate, technologically mature, and widely used in shipbuilding, rail transportation, and other fields. However, current noise reduction structures used in aircraft generally have a narrow noise reduction spectrum and poor low-frequency noise reduction performance. Research indicates that filling the honeycomb with sound-absorbing material is an effective way to improve low-frequency noise reduction performance.

[0003] However, existing sound-absorbing honeycomb structures are generally paper honeycomb structures, with internal filling materials such as polyester resin and melamine foam. Their mechanical structural strength and corrosion resistance are poor, and they cannot meet the performance requirements of the engine nacelle on aircraft in terms of operating temperature range and resistance to moisture, salt spray and acid / alkalinity.

[0004] Therefore, the inventors provide a basalt fiber cotton honeycomb core, honeycomb structure and filling method thereof. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] This invention provides a basalt fiber cotton honeycomb core, honeycomb structure and filling method, which solves the technical problems of poor mechanical strength and corrosion resistance and insufficient low-frequency noise reduction capability of existing sound-absorbing honeycomb structures.

[0007] (2) Technical solution

[0008] The first aspect of the present invention provides a basalt fiber cotton honeycomb core, wherein the honeycomb core is filled with basalt fiber cotton and the honeycomb core is made of metal.

[0009] Furthermore, the areal density of the basalt fiber cotton is 410–810 g / m³. 2 .

[0010] Furthermore, the thickness of the basalt fiber cotton is 15mm to 25mm.

[0011] Furthermore, the basalt fiber cotton has a regular hexagonal columnar structure.

[0012] A second aspect of the present invention provides a basalt fiber cotton honeycomb structure, including an upper panel, a lower panel and the aforementioned honeycomb core, wherein the upper panel and the lower panel are respectively attached to the upper and lower surfaces of the honeycomb core, the upper panel has perforations and the lower panel does not have perforations.

[0013] A third aspect of the present invention provides a method for filling a basalt fiber cotton honeycomb core, comprising the following steps:

[0014] Basalt fiber cotton is dehydrated and dried.

[0015] Liquid tert-butanol was injected into the dehydrated and dried basalt fiber cotton, and the liquid tert-butanol was solidified.

[0016] The solidified basalt fiber cotton is cut into regular hexagonal columns that match the inner cavity size, core height, and arrangement direction of the honeycomb core.

[0017] The regular hexagonal columnar material is filled into the honeycomb core and fits into the inner cavity of the honeycomb core.

[0018] A basalt fiber cotton-filled honeycomb core was subjected to vacuum freeze-drying to sublimate and volatilize tert-butanol, thereby obtaining a basalt fiber cotton honeycomb structure.

[0019] Furthermore, the dehydration and drying treatment of the basalt fiber cotton specifically involves a drying temperature of 200±5℃ and a drying time of 3 to 4 hours.

[0020] Furthermore, solidification and curing are carried out at a temperature of 15℃ to 20℃.

[0021] Furthermore, the step of cutting the cured basalt fiber cotton into regular hexagonal prisms with the same inner cavity size, core height, and arrangement direction as the honeycomb core specifically includes the following steps:

[0022] The solidified basalt fiber cotton is adsorbed onto the cutting platform, and the honeycomb core is placed directly above the basalt fiber cotton.

[0023] The honeycomb core is clamped and fixed, and the processing path of the CNC cutting needle is controlled so that it reads and records the inner cavity contour route of the honeycomb core;

[0024] The honeycomb core is moved horizontally away, and the CNC cutting needle is moved vertically downward to cut out regular hexagonal columnar fiber cotton on the basalt fiber cotton, which has the same inner cavity size, core height and arrangement direction as the honeycomb core.

[0025] Furthermore, the process of vacuum freeze-drying the honeycomb core filled with basalt fiber cotton specifically involves the following steps: the vacuum degree of the freeze-drying process is 50±30Pa, the temperature is 50±5℃, and the time is 3 to 5 hours.

[0026] (3) Beneficial effects

[0027] In summary, this invention, by filling basalt fiber cotton, still exhibits a good sound absorption coefficient in low-frequency noise environments. Acoustic performance testing results show that the low-frequency sound absorption coefficient and noise reduction spectrum range of this invention are increased compared to the original without porous sound-absorbing material. Furthermore, compared to non-metallic honeycomb cores, it has higher mechanical structural strength. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a basalt fiber cotton honeycomb core provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic flowchart of a method for filling a basalt fiber cotton honeycomb core according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the CNC cutting needle reading the contour path in a filling method for basalt fiber cotton honeycomb core provided in an embodiment of the present invention.

[0032] In the picture:

[0033] 1-Honeycomb core; 2-Basalt fiber cotton; 3-Clamp; 4-CNC cutting needle. Detailed Implementation

[0034] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Figure 1 This is a schematic diagram of the structure of a basalt fiber cotton honeycomb core provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the honeycomb core 1 is filled with basalt fiber cotton 2, and the honeycomb core 1 is made of metal.

[0037] Specifically, the areal density of basalt fiber cotton 2 is 410–810 g / m³. 2 The thickness of the basalt fiber cotton 2 is 15mm to 25mm. This size design is intended to improve its acoustic performance. The basalt fiber cotton 2 is designed as a regular hexagonal columnar structure to facilitate its fit with the inner wall of the honeycomb core 1, ensuring a proper fit between the honeycomb core 1 and the basalt fiber cotton 2. The honeycomb core 1 is preferably an aluminum honeycomb.

[0038] Acoustic performance testing showed that, compared to the original method without porous sound-absorbing material, the present invention increased the low-frequency sound absorption coefficient and the noise reduction spectrum range. Specifically, the honeycomb height was 15mm and the filling density was 32.40kg / m³. 3 The honeycomb core has a noise reduction spectral range improvement rate of 60%.

[0039] This invention provides a basalt fiber cotton honeycomb structure, including an upper panel, a lower panel, and a honeycomb core. The upper and lower panels are respectively attached to the upper and lower surfaces of the honeycomb core. The upper panel has perforations, while the lower panel does not. This basalt fiber cotton honeycomb structure has advantages such as excellent noise reduction performance, high structural strength, light weight, good high-temperature resistance, and good corrosion resistance. It can be used in the sound liner structure of certain aircraft to achieve good sound absorption and noise reduction functions.

[0040] Figure 2 This is a schematic flowchart of a method for filling a basalt fiber cotton honeycomb core according to an embodiment of the present invention, as shown below. Figure 2 As shown, the method may include the following steps:

[0041] S100, Dehydration and drying treatment of basalt fiber cotton;

[0042] S200, inject liquid tert-butanol into the dehydrated and dried basalt fiber cotton, and solidify the liquid tert-butanol;

[0043] S300. Cut the cured basalt fiber cotton into regular hexagonal columns that are consistent with the inner cavity size, core height and arrangement direction of the honeycomb core.

[0044] S400: Fill the honeycomb core with regular hexagonal prisms and fit them into the inner cavity of the honeycomb core;

[0045] S500: Vacuum freeze-drying is performed on the honeycomb core filled with basalt fiber cotton to sublimate and volatilize tert-butanol, thereby obtaining a basalt fiber cotton honeycomb structure.

[0046] In the above embodiments, after the cut basalt fiber cotton is filled into the inner cavity of the honeycomb core, it exerts no stress or deformation on the inner wall of the honeycomb core, ensuring the flatness of the honeycomb structure; the CNC-cut regular hexagonal columnar basalt fiber cotton has high dimensional accuracy, ensuring the fit gap between the honeycomb core and the filling fiber; the filling fiber is fixed on the lower non-perforated panel, preventing the filling fiber from shaking or escaping in the honeycomb core, effectively controlling the pore blockage rate of the upper perforated panel, and ensuring the noise reduction capability of the sound-absorbing liner.

[0047] The use of tert-butanol vacuum freeze-drying technology can solve the problem that basalt fiber cannot be directly mechanically processed due to its soft material and insufficient rigidity. After sublimation drying, the original mechanical properties, sound absorption properties and corrosion resistance of basalt fiber cotton will not be changed.

[0048] The drying temperature is 200±5℃ and the drying time is 3~4h.

[0049] The solidification process is carried out at a temperature of 15℃ to 20℃.

[0050] The freeze-drying process involves a vacuum of 50±30Pa, a temperature of 50±5℃, and a time of 3–5 hours. Freeze-drying can sublimate and dry the solidified tert-butanol, achieving efficient filling of the basalt fiber cotton honeycomb structure.

[0051] As an optional implementation, in step S300, the cured basalt fiber cotton is cut into regular hexagonal prisms with the same inner cavity size, core height, and arrangement direction as the honeycomb core. This specifically includes the following steps:

[0052] S301. Adsorb the cured basalt fiber cotton onto the cutting platform and place the honeycomb core directly above the basalt fiber cotton.

[0053] S302. Clamp and fix the honeycomb core, control the processing path of the CNC cutting needle, and make it read and record the inner cavity contour route of the honeycomb core.

[0054] S303. Horizontally move the honeycomb core aside, and move the CNC cutting needle vertically downward to cut out regular hexagonal columnar fiber cotton on the basalt fiber cotton, which has the same inner cavity size, core height and arrangement direction as the honeycomb core.

[0055] In the above embodiments, such as Figure 3 As shown, fixture 3 clamps and fixes the honeycomb core 1, and computer programming controls the machining path of CNC cutting needle 4 to read and input the inner cavity contour route of the honeycomb core 1. The integrated cutting and filling fixture can realize the automated control of the cutting and filling process, ensuring that the cutting size is consistent with the inner cavity contour of the honeycomb core, and that the filling density and height are uniform. The mechanical operation provides high efficiency and stable quality.

[0056] Example 1

[0057] A highly efficient filling method for basalt fiber cotton honeycomb structure includes the following steps:

[0058] S1: A surface density of 410 g / m² is used. 2 The basalt fiber cotton has a thickness of 15mm; the basalt fiber cotton is glued and fixed to the lower non-perforated panel using adhesive J116-A, and the panel thickness is 1mm.

[0059] S2: Place the basalt fiber cotton into a hot drying oven, set the drying temperature to 200℃ and the drying time to 4 hours, and carry out dehydration and drying treatment.

[0060] S3: Heat solid tert-butanol to 26°C to melt it into a liquid state.

[0061] S4: Inject liquid tert-butanol into the dehydrated and dried basalt fiber cotton, and then place it in a CNC machining chamber with the ambient temperature set at 17°C to allow it to solidify.

[0062] S5: Adsorb the cured basalt fiber cotton onto the cutting platform. The inscribed circle diameter of the filled honeycomb core is 12.7mm and the wall thickness is 0.07mm. Place the honeycomb core directly above the basalt fiber cotton.

[0063] S6: An assembly fixture is used to clamp and fix the honeycomb core. The CNC cutting needle is controlled by computer programming to read and record the inner cavity contour route of the honeycomb core.

[0064] S7: Using an assembly fixture, the honeycomb core is moved horizontally, and the CNC cutting needle moves vertically downward to cut out regular hexagonal columnar fiber cotton on the solidified basalt fiber cotton, which has the same cavity size, core height and arrangement direction as the honeycomb core.

[0065] S8: Using an assembly fixture, move the honeycomb core horizontally back and vertically downward until the regular hexagonal columnar basalt fiber cotton is filled into the honeycomb core and fits into the inner cavity of the honeycomb core.

[0066] S9: Use an assembly fixture to clamp the perforated panel and move it vertically downwards to fit it onto the upper surface of the honeycomb core.

[0067] S10: The filled honeycomb structure is placed in a freeze dryer and subjected to vacuum freeze drying. The freeze drying process is performed at a vacuum degree of 60 Pa, a temperature of 50 °C, and a time of 4 h, so that the solidified tert-butanol is sublimated and dried, thereby realizing the filling preparation of the basalt fiber cotton honeycomb structure.

[0068] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0069] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A method for filling a basalt fiber cotton honeycomb core, wherein the honeycomb core is filled with basalt fiber cotton, and the honeycomb core is made of metal, characterized in that... The method includes the following steps: Basalt fiber cotton is dehydrated and dried. Liquid tert-butanol was injected into the dehydrated and dried basalt fiber cotton, and the liquid tert-butanol was solidified. The solidified basalt fiber cotton is cut into regular hexagonal columns that are consistent with the inner cavity size, core height and arrangement direction of the honeycomb core. The regular hexagonal columnar material is filled into the honeycomb core and fits into the inner cavity of the honeycomb core. A basalt fiber cotton-filled honeycomb core was subjected to vacuum freeze-drying to sublimate and volatilize tert-butanol, thereby obtaining a basalt fiber cotton honeycomb structure.

2. The filling method according to claim 1, characterized in that, The dehydration and drying treatment of basalt fiber cotton specifically includes: The drying temperature is 200±5℃, and the drying time is 3 to 4 hours.

3. The filling method according to claim 1, characterized in that, The liquid tert-butanol was solidified at a temperature of 15°C to 20°C.

4. The filling method according to claim 1, characterized in that, The process of cutting the cured basalt fiber cotton into regular hexagonal prisms with the same inner cavity size, core height, and arrangement direction as the honeycomb core includes the following steps: The solidified basalt fiber cotton is adsorbed onto the cutting platform, and the honeycomb core is placed directly above the basalt fiber cotton. The honeycomb core is clamped and fixed, and the processing path of the CNC cutting needle is controlled so that it reads and records the inner cavity contour route of the honeycomb core; The honeycomb core is moved horizontally away, and the CNC cutting needle is moved vertically downward to cut out regular hexagonal columnar fiber cotton on the basalt fiber cotton, which has the same inner cavity size, core height and arrangement direction as the honeycomb core.

5. The filling method according to claim 1, characterized in that, The vacuum freeze-drying of the honeycomb core filled with basalt fiber cotton specifically involves: The freeze-drying process uses a vacuum of 50±30 Pa, a temperature of 50±5℃, and a time of 3 to 5 hours.

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