Honeycomb sandwich acoustic liner structure

Abstract

A honeycomb sandwich acoustic liner structure not only can improve sound absorption and noise reduction effects, but also can meet the requirements of an engine for broadband sound absorption and noise reduction. Comprising a top panel provided with a plurality of sound absorption holes; the honeycomb sandwich panel comprises a plurality of honeycomb core grids, and the top panel is connected to the end face of one side, in the height direction, of the honeycomb sandwich panel; the top panel is connected to the end face of one side of the honeycomb sandwich panel in the height direction, the bottom panel is connected to the end face of the other side of the honeycomb sandwich panel in the height direction, and one or more particles capable of freely moving are contained in a cavity defined by the top panel, all the honeycomb core grids of the honeycomb sandwich panel and the bottom panel.

Description

Technical Field

[0001] The utility model relates to a honeycomb sandwich acoustic lining structure, which is used for controlling high-intensity noise environments such as noise reduction design of an aeroengine nacelle. Background Art

[0002] In the past, as an acoustic lining structure for an aeroengine nacelle, a single-degree-of-freedom acoustic lining structure including a layer of honeycomb sandwich panel and a double-degree-of-freedom acoustic lining structure including two layers of honeycomb sandwich panels have been known. The above-mentioned single-degree-of-freedom acoustic lining structure is configured such that the cross-section of each honeycomb cell in the honeycomb sandwich panel along the height direction is hexagonal and the structure of each honeycomb is the same, and it can only have a good sound absorption and noise reduction effect on the noise near a single specific frequency.

[0003] Compared with the above-mentioned single-degree-of-freedom acoustic lining structure, the above-mentioned double-degree-of-freedom acoustic lining structure is only different in that it includes two layers of honeycomb sandwich panels and can have a good sound absorption and noise reduction effect on the noise near two specific frequencies.

[0004] However, both the above-mentioned single-degree-of-freedom acoustic lining structure and the double-degree-of-freedom acoustic lining structure absorb sound and reduce noise through the mechanical impedance of the honeycomb sandwich panel itself and the acoustic impedance generated by the air friction inside it, and the mechanical impedance of the honeycomb sandwich panel itself and the acoustic impedance generated by the air friction inside it are small. Therefore, the sound absorption and noise reduction effect is limited.

[0005] In addition, compared with the requirement of broadband sound absorption and noise reduction of the engine, the sound absorption and noise reduction capabilities of the above-mentioned single-degree-of-freedom acoustic lining structure and the double-degree-of-freedom acoustic lining structure are still insufficient. Summary of the Utility Model

[0006] The present utility model is completed in view of the above technical problems, and its purpose is to provide a honeycomb sandwich acoustic lining structure that can both improve the sound absorption and noise reduction effect and meet the requirement of broadband sound absorption and noise reduction of the engine.

[0007] One aspect of the present utility model provides a honeycomb sandwich acoustic lining structure, including: a top panel, the top panel is provided with a plurality of sound absorption holes; a honeycomb sandwich panel, the honeycomb sandwich panel includes a plurality of honeycomb cells, the top panel is connected to one end face of the honeycomb sandwich panel in the height direction; and a bottom panel, the bottom panel is connected to the other end face of the honeycomb sandwich panel in the height direction, and it is characterized in that more than one particle that can move freely is received in the cavity surrounded by the top panel, each of the honeycomb cells of the honeycomb sandwich panel and the bottom panel.

[0008] According to the above structure, since more than one particle that can move freely is accommodated in the cavity formed by the top panel, the honeycomb core cells, and the bottom panel, factors such as the friction between particles, the friction inside the particles, the kinetic energy and potential energy of the particles will all generate acoustic impedance. Therefore, as the acoustic impedance of the honeycomb sandwich acoustic lining structure as a whole, on the basis of the acoustic impedance generated by the air friction in the existing cavity and the structure of the honeycomb core cells itself, the acoustic impedance generated by more than one freely moving particle as described above is also increased. Thus, the acoustic impedance increases. In this way, the vibration of the sound wave entering the interior of the honeycomb sandwich acoustic lining structure is weakened, and thereby, the sound absorption and noise reduction effect of the honeycomb sandwich acoustic lining structure can be improved.

[0009] In addition, since more than one particle moves freely in the cavity, when the particles move to different positions in the cavity, the composition inside the cavity of the cavity changes, and accordingly, the acoustic modal vibration mode and frequency of the cavity change. Moreover, the particles have a reflection effect on the sound wave, changing the cavity from a resonant cavity with a fixed modal frequency to a reverberant cavity with randomly changing modal frequencies. Moreover, under the influence of the external environmental vibration of the acoustic lining structure, the particles will continuously change their positions in the cavity, and the acoustic modal frequency of the cavity will change within a large range. In this way, the frequency bandwidth of sound absorption and noise reduction can be increased, and sound absorption and noise reduction can be achieved with greater freedom.

[0010] The honeycomb sandwich acoustic lining structure of the second aspect of the present utility model is based on the honeycomb sandwich acoustic lining structure of the first aspect of the present utility model, and is characterized in that the diameter of the particles is greater than the diameter of the sound absorption holes and less than the distance between the opposite surfaces in the cavity.

[0011] According to the above structure, the diameter of the particles is greater than the diameter of the sound absorption holes and less than the distance between the opposite surfaces in the cavity. Therefore, the particles are allowed to move freely in the cavity and will not block the sound absorption holes.

[0012] The honeycomb sandwich acoustic lining structure of the third aspect of the present utility model is based on the honeycomb sandwich acoustic lining structure of the first aspect or the second aspect of the present utility model, and is characterized in that the honeycomb sandwich panel includes a plurality of inclined ribs inclined with respect to the height direction and a plurality of vertical ribs parallel to the height direction. In a plane perpendicular to the height direction, the plurality of vertical ribs are arranged in one direction, the plurality of inclined ribs are arranged in another direction intersecting with the one direction, and the plurality of inclined ribs are staggered in the one direction.

[0013] According to the above structure, the honeycomb sandwich panel includes a plurality of inclined vertical ribs inclined with respect to the height direction and a plurality of vertical vertical ribs parallel to the height direction. Moreover, in a plane perpendicular to the height direction, the plurality of vertical vertical ribs are arranged in one direction, and the plurality of inclined vertical ribs are arranged in another direction intersecting the one direction. The structure of the inclined vertical ribs is more firm than that of the vertical vertical ribs, and the plurality of inclined vertical ribs are staggered in one direction, which can further improve the structural strength of the overall honeycomb core in one direction.

[0014] The honeycomb sandwich sound lining structure of the fourth aspect of the present invention is based on the honeycomb sandwich sound lining structure of the third aspect of the present invention, and is characterized in that each of the honeycomb cores is composed of two of the inclined vertical ribs and two of the vertical vertical ribs.

[0015] According to the above structure, since each honeycomb core is composed of two inclined vertical ribs and two vertical vertical ribs, the inclined vertical ribs can ensure the overall structural strength of the honeycomb sandwich panel, while the vertical vertical ribs can ensure the overall mechanical properties of the honeycomb sandwich panel and are convenient for manufacturing.

[0016] The honeycomb sandwich sound lining structure of the fifth aspect of the present invention is based on the honeycomb sandwich sound lining structure of the third aspect of the present invention, and is characterized in that when observed along the height direction, each of the honeycomb cores is in the shape of a quadrilateral with different sizes.

[0017] According to the above structure, since when observed along the height direction, each honeycomb core is in the shape of a quadrilateral with different sizes, the frequencies of noise that each aluminum honeycomb core can absorb are different. Therefore, the frequency bandwidth of noise absorption can be increased.

[0018] In addition, the cross-section of the existing honeycomb core is a regular hexagon and will overlap with itself every 60 degrees of rotation relative to the center. Therefore, a large number of acoustic modal frequencies will coincide at specific frequencies. In contrast, the cross-section of the honeycomb core of the present invention is a quadrilateral and will only overlap with itself when rotated 180 or 360 degrees relative to the center. Therefore, the number of acoustic modal frequencies that coincide at specific frequencies is reduced. In this way, the frequency bandwidth of sound absorption can be increased compared with the existing honeycomb core.

[0019] In addition, since when observed along the height direction, the cross-sectional shapes of each honeycomb core, that is, quadrilaterals, are different, the frequencies of sound absorption of each honeycomb core are different. In this way, the frequency bandwidth of sound absorption can be further increased.

[0020] The honeycomb sandwich sound lining structure of the sixth aspect of the present invention is based on the honeycomb sandwich sound lining structure of the third aspect of the present invention, and is characterized in that the quadrilaterals are different in size at different height positions of the honeycomb core.

[0021] According to the above structure, the cross-sectional shape of each honeycomb cell, that is, the quadrilateral, is different in size at different height positions. Therefore, even within the same honeycomb cell, the frequencies that can absorb sound are different at different height positions. Thus, the frequency bandwidth that can absorb sound can be further increased.

[0022] The honeycomb sandwich acoustic lining structure of the seventh aspect of the present invention is based on the honeycomb sandwich acoustic lining structure of the third aspect. Its characteristic is that when observing along the other direction, the honeycomb cell is in the shape of an isosceles trapezoid.

[0023] According to the above structure, since the honeycomb cell is in the shape of an isosceles trapezoid when observing along the other direction, the structural strength of the honeycomb cell can be improved compared with other shapes such as rectangles.

[0024] The honeycomb sandwich acoustic lining structure of the eighth aspect of the present invention is based on the honeycomb sandwich acoustic lining structure of the first aspect or the second aspect. Its characteristic is that the particles are made of a high-damping material.

[0025] According to the above structure, since the particles are made of a high-damping material, the acoustic impedance generated by the particles themselves is large, and the overall acoustic impedance of the honeycomb sandwich acoustic lining structure can be further improved. Thus, the vibration of the sound wave entering the interior of the honeycomb sandwich acoustic lining structure is further weakened. Thereby, the sound absorption, noise reduction, and shock absorption effects of the honeycomb sandwich acoustic lining structure can be further improved.

[0026] The honeycomb sandwich acoustic lining structure of the ninth aspect of the present invention is based on the honeycomb sandwich acoustic lining structure of the first aspect or the second aspect. Its characteristic is that the particles are made of rigid solid foam, rigid porous foam, hollow rigid plastic, a powder / debris core material wrapped in a flexible shell, and ceramic balls.

[0027] According to the above structure, since the particles are made of rigid solid foam, rigid porous foam, hollow rigid plastic, a powder / debris core material wrapped in a flexible shell, and ceramic balls, the foam is light in weight and can absorb sound, can move freely in the cavity without generating noise, and the ceramic balls have good high-temperature resistance and will not be deformed by heat even in a high-temperature environment near the engine.

[0028] (Main effects of this embodiment)

[0029] In the honeycomb sandwich acoustic lining structure according to this embodiment, since one or more freely movable particles are accommodated in the cavity surrounded by the top panel, honeycomb cells, and bottom panel, factors such as the friction between particles, the friction inside the particles, the kinetic energy and potential energy of the particles will all generate acoustic impedance. Therefore, as the acoustic impedance of the honeycomb sandwich acoustic lining structure as a whole, on the basis of the acoustic impedance generated by the air friction in the existing cavity and the structure of the honeycomb cells itself, the acoustic impedance generated by one or more freely movable particles as described above is also added. Thus, the acoustic impedance increases. In this way, the vibration of the sound wave entering the inside of the honeycomb sandwich acoustic lining structure is weakened. Thereby, the sound absorption and noise reduction effect of the honeycomb sandwich acoustic lining structure can be improved. In addition, since one or more particles move freely in the cavity, when the particles move to different positions in the cavity, the composition inside the cavity changes, and accordingly, the acoustic mode vibration pattern and frequency of the cavity change. Moreover, the particles have a reflection effect on the sound wave, changing the cavity from a resonance cavity with a fixed modal frequency to a reverberation cavity with randomly varying modal frequencies. Moreover, under the influence of the external environmental vibration of the acoustic lining structure, the particles will continuously change their positions in the cavity, and the acoustic modal frequency of the cavity will change within a large range. In this way, the frequency bandwidth of sound absorption and noise reduction can be increased, and sound absorption and noise reduction can be achieved with greater freedom. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the various embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 is a perspective view showing the honeycomb sandwich acoustic lining structure of the embodiment of the present invention.

[0032] Figure 2 is shown as viewed from the first direction Figure 1 the side view obtained of the shown honeycomb sandwich acoustic lining structure.

[0033] Figure 3 is shown as viewed from the second direction Figure 1 the side view obtained of the shown honeycomb sandwich acoustic lining structure.

[0034] Figure 4 is shown as viewed from the height direction Figure 1 the top view obtained of the shown honeycomb sandwich acoustic lining structure.

[0035] Figure 5 is shown as removing Figure 1 the top panel of the shown honeycomb sandwich acoustic lining structure in a perspective view.

[0036] (Symbolic description)

[0037] 1 Honeycomb sandwich acoustic lining structure;

[0038] 2 Top panel;

[0039] 21 Sound absorption holes;

[0040] 211 First sound absorption hole;

[0041] 212 Second sound absorption hole;

[0042] 3 Honeycomb sandwich panel;

[0043] 31 Honeycomb core cells;

[0044] 310 Cavity;

[0045] 311 Oblique ribs;

[0046] 312 Vertical ribs;

[0047] 4 Particles;

[0048] 41 Core part;

[0049] 42 Coating;

[0050] 5 Bottom panel. Detailed implementation manners

[0051] Hereinafter, with reference to Figures 1 to 5 each implementation manner of the honeycomb sandwich acoustic lining structure of the present utility model will be described. The honeycomb sandwich acoustic lining structure of this implementation manner is used for the control of high sound intensity environments such as the noise reduction design of an aeroengine nacelle. Figures 1 to 5 Only the schematic structure of the honeycomb sandwich acoustic lining structure related to the present utility model is illustrated, and more detailed parts of this structure are omitted from the illustration herein.

[0052] It should be noted that the honeycomb sandwich acoustic lining structure of the present utility model is generally wedge-shaped, but for the convenience of illustrating the detailed structures of the vertical ribs and the oblique ribs, only a part of the cuboid composed of a plurality of vertical ribs and a plurality of oblique ribs of the wedge shape is illustrated in Figures 1 to 5 hereinafter. Moreover, in the preferred implementation manner of Figures 1 to 5 hereinafter, more than one freely movable particle is accommodated in only two honeycomb core cells of the honeycomb sandwich acoustic lining structure 1, but actually more than one freely movable particle is accommodated in each honeycomb core cell. And the present utility model is not limited thereto, as long as more than one particle is accommodated in more than one honeycomb core cell.

[0053] Hereinafter, for the sake of convenience of description, the height direction in the honeycomb core sound lining structure 1 is set as the Z direction, one direction in the plane perpendicular to the Z direction is set as the X direction (i.e., the first direction), and the other direction orthogonal to the X direction is set as the Y direction (i.e., the second direction).

[0054] (Honeycomb core sound lining structure 1 of the embodiment)

[0055] In this embodiment, as Figure 1 shown, the honeycomb core sound lining structure 1 is composed of a top panel 2, a bottom panel 5, and a honeycomb core panel 3 sandwiched between the top panel 2 and the bottom panel 5, and is in an overall cuboid shape.

[0056] Among them, as Figure 4 shown, when viewed from above along the Z direction, the top panel 2 is rectangular, and twelve sound absorption holes 21 are linearly arranged in the X direction. These twelve sound absorption holes 21 are formed by alternating six first sound absorption holes 211 and six second sound absorption holes 212. Ten suction holes 21 are linearly formed in the Y direction. These ten sound absorption holes 21 are formed by alternating five first sound absorption holes 211 and five second sound absorption holes 212. The diameter of the first sound absorption hole 211 is smaller than the diameter of the second sound absorption hole 212.

[0057] As Figure 1 shown, the bottom panel 5 is opposite to the top panel 2 on the Z2 side of the top panel 2, and is in a rectangular shape corresponding to the top panel 2. In this embodiment, the bottom panel 5 has the same shape and size as the top panel 2, but the present invention is not limited thereto, and the bottom panel 5 may also have a different shape and size from the top panel 2.

[0058] As Figure 5 shown, a honeycomb core panel 3 is sandwiched between the top panel 2 and the bottom panel 5. The honeycomb core panel 3 is formed with a total of 110 honeycomb core cells 31, where 11 honeycomb core cells 31 are arranged in the X direction and 10 honeycomb core cells 31 are arranged in the Y direction. Moreover, as Figure 2 shown, when observing the honeycomb core sound lining structure 1 from the X2 side to the X1 side in Figure 1 , among the 10 honeycomb core cells 31 arranged in the Y direction, in the area of the top panel 2 corresponding to the honeycomb core cell 31 closest to the Y2 side, a second sound absorption hole 212 is formed. Starting from this honeycomb core cell 31, the first sound absorption hole 211, the second sound absorption hole 212, the first sound absorption hole 211... are alternately arranged one by one until the area of the top panel 2 corresponding to the honeycomb core cell 31 closest to the Y1 side is formed with the first sound absorption hole 211.

[0059] As Figure 3 shown, when observing from Figure 1When observing the honeycomb sandwich acoustic lining structure 1 from the Y1 side to the Y2 side, among the 11 honeycomb core cells 31 arranged in the X direction, a first sound absorption hole 211 is formed in the area of the top panel 2 corresponding to the honeycomb core cell 31 closest to the X2 side. Starting from this honeycomb core cell 31, the second sound absorption holes 212 and the first sound absorption holes 211 are arranged alternately one by one... until a second sound absorption hole 212 is formed in the area of the top panel 2 corresponding to the honeycomb core cell 31 closest to the X1 side.

[0060] In the top panel 2 of the honeycomb sandwich acoustic lining structure 1 of the present embodiment, the first sound absorption holes 211 and the second sound absorption holes 212 are shown Figure 4 in the manner as shown.

[0061] As Figure 5 shown, the honeycomb sandwich panel 3 sandwiched between the top panel 2 and the bottom panel 5 is composed of a total of 10 columns of diagonal ribs 311 formed by 9 vertical ribs 312 arranged in the Y direction (i.e., one direction) and 12 diagonal ribs 311 arranged in the X direction (i.e., the other direction). Among them, the 10 columns of diagonal ribs 311 and the 9 vertical ribs 312 are alternately arranged in the Y direction from the Y1 side in the manner of one column of diagonal ribs 311 and one vertical rib 312, and both the closest to the Y1 side and the closest to the Y2 side are a total of 12 diagonal ribs 311 in one column. Each of the 9 vertical ribs 312 extends throughout the entire X direction of the bottom panel 5, and each of the 12 diagonal ribs 311 is inclined with respect to the Z direction (i.e., the height direction of the honeycomb sandwich panel 3). For example, as Figure 5 shown, taking the first column of 12 diagonal ribs 311 starting from the Y1 side as an example, the adjacent diagonal ribs 311 approach each other as they go from the Z2 side towards the Z1 side. Taking the second column of 12 diagonal ribs 311 starting from the Y1 side as an example, the adjacent diagonal ribs 311 move away from each other as they go from the Z2 side towards the Z1 side. In this way, the diagonal ribs 311 and the vertical ribs 312 in each column are alternately arranged from the Y1 side to the Y2 side.

[0062] By arranging the vertical ribs 311 and the diagonal ribs 312 in the honeycomb sandwich panel 3 in the above manner, 11 honeycomb core cells 31 in the X direction and 10 honeycomb core cells 31 in the Y direction, a total of 11 * 10 = 110 honeycomb core cells 31 can be formed. Moreover, when observing along the Y direction, each honeycomb core cell 31 is an isosceles trapezoid, and when observing along the Z direction, each honeycomb core cell 31 is a rectangle, and the sizes of the rectangles of the honeycomb core cells 31 are different at different positions in the Z direction.

[0063] In addition, when the top panel 2 forming the first sound absorption holes 211 and the second sound absorption holes 212 in the above-described manner covers the honeycomb core sandwich panel 3 from the Z1 side, the sound absorption holes 211 as described above are formed in the region of the top panel 2 corresponding to the short side of the isosceles trapezoid of the honeycomb core cell 31, and the sound absorption holes 212 as described above are formed in the region of the top panel 2 corresponding to the long side of the isosceles trapezoid of the honeycomb core cell 31.

[0064] A cavity 310 is formed inside the 110 honeycomb core cells 31 formed as described above. Although Figure 1 、 3 、only 2 of the 5 honeycomb core cells 31 contain more than one freely movable particle 4. These particles 4 are respectively spherical, ellipsoidal, oblong spherical, etc., spherical shapes that are convenient for bouncing, and include a core and a coating on the outer surface covering the core. They can be either solid or hollow. Their diameters are larger than the diameters of the first sound absorption holes 211 and the second sound absorption holes 212 and smaller than the distance between the opposite faces of the cavity 310. Thus, it is convenient for each particle 4 to move freely in the cavity 310 and not block each sound absorption hole.

[0065] Moreover, the particles 4 are preferably made of a material with light weight and high damping, which can increase the acoustic impedance of the particles 4 themselves while facilitating the bouncing of the particles 4. Moreover, each particle 4 is preferably made of rigid solid foam, rigid porous foam, hollow rigid plastic, a flexible outer shell wrapping a powder / debris core material, or ceramic balls. Since the particles 4 are light in weight, they can move under high-frequency micro-amplitude vibrations of the external environment, and preferably can move under the drive of high-intensity sound waves.

[0066] In addition, in the present embodiment, it is preferable that the top panel 2, the vertical ribs 312 and the inclined ribs 311 forming each honeycomb core cell 31 in the honeycomb core sandwich panel 3, and the bottom panel 5 are connected by bonding, high-temperature curing, welding, etc. Moreover, it is preferable that the top panel 2, the honeycomb core sandwich panel 3, and the bottom panel 5 are obtained from a single integral block.

[0067] (Technical effects of the present embodiment)

[0068] According to the honeycomb core sandwich acoustic lining structure 1 of the present embodiment, as Figure 1As shown, one or more freely movable particles 4 are accommodated in the cavity 310 surrounded by the top panel 2, the honeycomb core lattice 31, and the bottom panel 5. Factors such as the friction between the particles 4, the friction inside the particles 4, the kinetic energy and potential energy of the particles 4 will all generate acoustic impedance. Therefore, as the acoustic impedance of the honeycomb sandwich acoustic lining structure 1 as a whole, on the basis of the acoustic impedance generated by the air friction in the existing cavity 310 and the structure of the honeycomb core lattice 31 itself, the acoustic impedance generated by one or more freely movable particles 4 as described above is also increased. Thus, the acoustic impedance increases. In this way, the vibration of the sound wave entering the interior of the honeycomb sandwich acoustic lining structure 1 is weakened. Thereby, the sound absorption and noise reduction effect of the honeycomb sandwich acoustic lining structure 1 can be improved. In addition, since one or more particles 4 move freely in the cavity, when the particles 4 move to different positions in the cavity 310, the composition inside the cavity 310 of the cavity changes, and the corresponding acoustic mode vibration pattern and frequency of the cavity 310 change. Moreover, the particles 4 have a reflecting effect on the sound wave, causing the cavity 310 to change from a resonant cavity with a fixed modal frequency to a reverberant cavity with a randomly changing modal frequency. Moreover, under the influence of the external environmental vibration of the honeycomb sandwich acoustic lining structure 1, the particles 4 will continuously change their positions in the cavity 310, and the acoustic modal frequency of the cavity 310 will change within a large range. In this way, the frequency bandwidth of sound absorption and noise reduction can be increased, and sound absorption and noise reduction can be achieved with greater freedom.

[0069] In addition, the diameter of the particles 4 is larger than the diameter of the second sound absorption holes 212 and smaller than the distance between the opposite surfaces in the cavity 310. Since the diameter of the second sound absorption holes 212 is larger than the diameter of the first sound absorption holes 211, the particles 4 will not leak out from these sound absorption holes. Moreover, since the particles 4 are smaller than the distance between the opposite surfaces in the cavity 310, the particles 4 can move freely in the cavity 310.

[0070] In addition, the honeycomb sandwich panel 3 includes 12 inclined ribs 311 inclined with respect to the Z direction (i.e., the height direction) and 9 vertical ribs 312 parallel to the height direction. In a plane perpendicular to the height direction, the 9 vertical ribs 312 are arranged in the Y direction, and the 12 inclined ribs 311 are arranged in the X direction. The 12 inclined ribs 311 are staggered in the Y direction. In this way, since the inclined surfaces of the inclined ribs 311 will cause the overall mechanical properties to decline and produce obvious anisotropy. By arranging the inclined ribs 311 in a staggered manner in the Y direction, the macroscopic mechanical properties of the overall acoustic lining structure can be improved.

[0071] In addition, each honeycomb core lattice 31 is respectively composed of two inclined ribs 311 and two vertical ribs 312. The honeycomb core lattice 31 arranged in this way is quadrilateral when viewed along the Z direction and is an isosceles trapezoid when viewed along the Y direction. Moreover, at different height positions, the size of the quadrilateral of the honeycomb core lattice 31 when viewed along the Z direction is different.

[0072] Thus, the shape of the existing honeycomb cell 31 when viewed along the Z direction is hexagonal, and this hexagon overlaps with itself every time it rotates 60 degrees relative to the center. Therefore, a large number of acoustic mode frequencies will coincide at a unified specific frequency. As a result, the bandwidth of the acoustic mode frequencies that can be absorbed will be affected. In contrast, the shape of the honeycomb cell 31 in the present embodiment when viewed along the Z direction is quadrilateral, and this quadrilateral only overlaps with itself when it rotates 180 degrees and 360 degrees. Therefore, compared with the hexagonal case, the number of overlapping specific frequencies is smaller, and the bandwidth of the acoustic mode frequencies that can be absorbed is larger. On this basis, the quadrilaterals of each honeycomb cell 31 when viewed along the Z direction are of different sizes at different positions in the Z direction (i.e., different height positions). Therefore, the acoustic mode frequencies absorbed by each honeycomb cell 31 are different. Thus, compared with the case where the existing honeycomb cells 31 have the same size as the hexagons when viewed along the Z direction, the bandwidth of sound absorption and noise reduction can be increased. In addition, since the structural strength of an isosceles trapezoid is better than that of a quadrilateral, by setting the shape of the honeycomb cell 31 when viewed along the Y direction as an isosceles trapezoid, the overall structural strength of the honeycomb sandwich acoustic lining structure 1 can be improved.

[0073] In addition, since the particles are made of rigid solid foam, rigid porous foam, hollow rigid plastic, a flexible shell wrapping powder / debris core material, and ceramic balls, the solid foam uses a lightweight foam material, so it has a light mass and will not generate noise even when freely moving within the honeycomb cell; the rigid porous foam uses a lightweight foam material and has a porous structure, so it has a light mass and will not generate noise even when freely moving within the honeycomb cell. The hollow rigid plastic has a hollow structure, so it has a light mass. The flexible shell wrapping powder / debris core material can endow the particles with elasticity because the shell is flexible. In addition, the particles are made of ceramic balls, and the ceramic balls have good high-temperature resistance, and the particles will not be thermally deformed even in the high-temperature environment near the engine.

[0074] <Other Embodiments>

[0075] In the above embodiment, the honeycomb cells of the honeycomb sandwich acoustic lining structure are quadrilateral when viewed from the Z direction, but the present invention is not limited to this. As long as the number of overlapping specific frequencies is less than that in the case of a hexagon, it can also be other shapes.

[0076] In the above embodiment, as the honeycomb sandwich acoustic lining structure, only a single-layer structure composed of a top panel, a honeycomb sandwich panel, and a bottom panel is listed, but the present invention is not limited to this, and it can also have

[0077] In the above-described embodiment, each honeycomb core cell of the honeycomb sandwich acoustic lining structure is an isosceles trapezoid when viewed in the Y direction. However, the present invention is not limited thereto, and it may also be in other shapes such as an X shape.

[0078] In the above-described embodiment, the inclined ribs 311 are staggeredly arranged in the Y direction. However, the present invention is not limited thereto, and the inclined ribs 311 may also be overlappedly arranged in the Y direction.

[0079] In the above-described embodiment, only five types of materials for the particles 4 are listed, namely rigid solid foam, rigid porous foam, hollow rigid plastic, flexible shell-wrapped powder / debris core material, and ceramic balls. However, the present invention is not limited thereto, and as long as the particles 4 are light in weight and elastic, other materials may also be used.

Claims

1. A honeycomb sandwich acoustic lining structure, comprising: A top panel, wherein the top panel is provided with a plurality of sound-absorbing holes; A honeycomb sandwich panel, the honeycomb sandwich panel comprising a plurality of honeycomb core cells, the top panel being connected to one side end surface of the honeycomb sandwich panel in a height direction; and A bottom panel, the bottom panel is connected to the other side end surface of the honeycomb sandwich panel in the height direction, It is characterized in that One or more particles that are free to move are contained in a cavity surrounded by the top panel, each of the honeycomb core cells of the honeycomb sandwich panel and the bottom panel.

2. The honeycomb sandwich acoustic lining structure according to claim 1, characterized in that: The diameter of the particle is larger than the diameter of the sound absorbing hole and smaller than the distance between the opposite surfaces in the cavity.

3. The honeycomb sandwich acoustic lining structure according to claim 1 or 2, characterized in that: The honeycomb sandwich panel includes a plurality of oblique ribs inclined relative to the height direction and a plurality of vertical ribs parallel to the height direction. In a plane perpendicular to the height direction, a plurality of the vertical ribs are arranged in one direction, and a plurality of the oblique ribs are arranged in another direction intersecting the one direction. The plurality of oblique ribs are staggered in the one direction.

4. The honeycomb sandwich acoustic lining structure according to claim 3, characterized in that: Each of the honeycomb core cells is respectively composed of two oblique ribs and two vertical ribs.

5. The honeycomb sandwich acoustic lining structure according to claim 3, characterized in that: When observed along the height direction, each of the honeycomb core cells is a quadrilateral of different sizes.

6. The honeycomb sandwich acoustic lining structure according to claim 5, characterized in that: The quadrilateral has different sizes at different height positions of the honeycomb core cell.

7. The honeycomb sandwich acoustic lining structure according to claim 3, characterized in that: When viewed along the other direction, the honeycomb core cell is in the shape of an isosceles trapezoid.

8. The honeycomb sandwich acoustic lining structure according to claim 1 or 2, characterized in that: The particles are made of a high damping material.

9. The honeycomb sandwich acoustic lining structure according to claim 1 or 2, characterized in that: The particles are made of hard solid foam, hard porous foam, hollow hard plastic, powder / crushed core material wrapped in a flexible shell, and ceramic balls.

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