Method for manufacturing a honeycomb structure and honeycomb structure thus obtained
By manufacturing honeycomb structures through bending and forming, the problem of material strip plastic deformation limitation in existing technologies has been solved, enabling diverse choices of materials and thicknesses, and achieving effective absorption of high-frequency and low-frequency sound waves in thin layers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- AIRBUS OPERATIONS (SAS)
- Filing Date
- 2022-05-26
- Publication Date
- 2026-07-14
AI Technical Summary
In the manufacturing of honeycomb structures, existing technologies limit the choice of material and thickness of the material strips due to plastic deformation, resulting in an increase in the thickness of the honeycomb structure and making it difficult to achieve effective absorption of high-frequency and low-frequency sound waves in thin layers.
By bending and shaping the first and second material strips, alternating first and second concave shapes are formed, and a honeycomb structure is formed by bending and connecting them, including a third cell between each row of cells. The connection of the material strips and the formation of channels are achieved by using bending lines and cuts.
It expands the range of material and thickness options, simplifies the assembly of the honeycomb structure, achieves effective absorption of high-frequency and low-frequency sound waves, and realizes efficient sound wave absorption in the thin layer of the honeycomb structure.
Smart Images
Figure CN115410545B_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method for manufacturing a honeycomb structure obtained from bent strips of material, and also to a honeycomb structure thus obtained. More broadly, this application relates to a sound-absorbing covering layer for use in aircraft. Background Technology
[0002] According to one embodiment, the sound-absorbing covering layer includes a porous layer, a honeycomb structure, and a reflective layer in contact with the medium through which sound waves propagate.
[0003] According to a simplified embodiment, a honeycomb structure comprises multiple identical cells with hexagonal cross-sections, adjacent to each other. This type of honeycomb structure is suitable for a certain frequency range, and more particularly for high frequencies. For low frequencies, larger cells are required, which leads to an increase in the thickness of the honeycomb structure. However, the sound-absorbing covering layer must be as thin as possible.
[0004] Reference FR-3.098.143 proposes a specific honeycomb structure for increasing the volume of cells without increasing the thickness of the honeycomb structure. For example... Figure 1 and Figure 2 As shown, this honeycomb structure includes multiple rows of cells 10, 10', each row of cells alternately having a first cell 12 and a second cell 14. These first cells are open in a direction intended to abut a first surface of the porous layer and closed in a direction intended to abut a second surface of the reflective layer. These second cells are closed in the direction of the first surface and open in the direction of the second surface. Each first cell 12 is connected to a second cell 14 via a conduit 16 positioned near the second surface. In this way, the volume of the cells corresponds to the sum of the volumes of the first cell 12, the second cell 14, and the conduit 16.
[0005] The multiple rows of small cells 10 and 10' are identical and are placed side by side with an offset, with the first cell of the first row placed against the second cell of the second row that is placed side by side with the first row.
[0006] According to one embodiment, each row of cells 10, 10' is obtained by connecting two material strips 18, 18'. Figure 3 As shown, each material strip 18, 18' alternately includes a first indentation 20 corresponding to half of the first chamber 12, a second indentation 22 corresponding to half of the second chamber 14, and a channel connecting the first indentation 20 and the second indentation 22 and corresponding to one half of the pipe 16.
[0007] According to a procedure, a method for manufacturing cellular structures includes... Figure 3The steps that can be seen include using tool 24 to shape the material strips 18, 18' by forging or stamping to obtain indentations 20, 22, and assembling the material strips 18, 18' by welding or adhesive bonding.
[0008] The forming process requires plastic deformation of the material, which causes the material to stretch in some areas and wrinkle in others. This plastic deformation limits the choice of material and thickness that can be used for the material strips 18 and 18'. Summary of the Invention
[0009] This invention aims to overcome all or some of the deficiencies of the prior art.
[0010] Therefore, the subject of this invention is a method for manufacturing a honeycomb structure having a first face and a second face and also having multiple rows of cells, each row of cells alternately having a first cell open in the direction of the first face and a second cell open in the direction of the second face; the honeycomb structure also includes third cells between each row of cells, these third cells being open in the direction of the first face and the second face.
[0011] According to the present invention, a method for manufacturing a honeycomb structure includes the steps of forming a first material strip and a second material strip by bending to obtain a first recessed shape and a second recessed shape for each material strip and also obtaining a connecting region separating the first recessed shape and the second recessed shape, the first material strip and the second material strip being identical; and further including the step of assembling the first material strip and the second material strip to form a honeycomb structure by abutting and connecting the connecting regions of the first material strip to the connecting regions of the second material strip, the first recessed shape and the second recessed shape being alternated and arranged to form a first cell and a second cell and also to form a third cell.
[0012] According to the invention, during the step of forming the first material strip and the second material strip by bending, each first material strip is bent to obtain a first channel, and each second material strip is bent to obtain a second channel, the first channel and the second channel forming a conduit, each of these conduits connecting a pair of first chambers and second chambers.
[0013] Compared to plastic deformation, bending allows for a wider range of choices regarding the materials and thicknesses of the first and second material strips. Furthermore, because the first and second material strips are identical, it facilitates the assembly of the honeycomb structure. This is because the first and second material strips can be easily rotated and offset to form the first and second cells.
[0014] According to another feature, each first material strip and second material strip includes main bend lines arranged such that each first recessed shape and second recessed shape includes a main surface separated from the first and second triangular sides, the first and second sides being arranged on both sides of the main surface; and also includes secondary bend lines arranged such that each first and second side is separated from the connection, the main surface is tilted relative to the connection area, and during the assembly step, the main surface of each first material strip abuts against and connects to the main surface of the second material strip.
[0015] According to another feature, for each first recessed shape and second recessed shape, the primary bend line and the secondary bend line are symmetrical with respect to the longitudinal intermediate axis that is equidistant from the connecting areas arranged on both sides of the first recessed shape and the second recessed shape.
[0016] According to another feature, the first channel and the second channel are positioned on the main surfaces of the first recessed shape and the second recessed shape, and each channel includes bends that are arranged such that each pair of first channels and second channels forms a conduit positioned between two abutting main surfaces.
[0017] According to another feature, each first channel and second channel includes a central bend line, and also includes two inclined bend lines that are symmetrical with respect to the central bend line and intersect at the central bend line.
[0018] According to another feature, the manufacturing method includes, prior to the bending and forming step, making a cut in the main surface of each first recessed shape and second recessed shape of each of the first and second material strips in a flat state, each cut being configured to communicate a first chamber or a second chamber with a conduit.
[0019] According to the first embodiment, each first material strip and second material strip includes a first longitudinal side and a second longitudinal side, and the cut is offset relative to the first longitudinal side and the second longitudinal side of the first material strip and the second material strip.
[0020] According to the second embodiment, each first material strip and second material strip includes a first longitudinal side and a second longitudinal side, and the cut intersects with one of the longitudinal sides of the first longitudinal side and the second longitudinal side of the first material strip and the second material strip.
[0021] Another subject of the invention is a honeycomb structure obtained by the manufacturing method, wherein the sound-absorbing covering layer comprises a porous layer, a reflective layer, and such a honeycomb structure between the porous layer and the reflective layer, and is also an aircraft comprising at least one such sound-absorbing covering layer.
[0022] More specifically, the subject of the present invention is a honeycomb structure having a first face and a second face and also having multiple rows of cells, each row of cells alternately having a first cell open in the direction of the first face and a second cell open in the direction of the second face. The honeycomb structure also includes third cells between each row of cells, these third cells being open in the direction of the first face and the second face. Each row of cells includes a first material strip and a second material strip placed abutting each other. Each first material strip and second material strip includes a first recessed shape and a second recessed shape and also includes a connecting region separating the first recessed shape and the second recessed shape. The first recessed shape and the second recessed shape are alternately arranged to form the first cell, the second cell, and also to form the third cell.
[0023] According to the present invention, the first material strip and the second material strip are identical and are formed by bending.
[0024] According to the present invention, the honeycomb structure includes channels, each of which connects a pair of first cells and second cells, each channel including a first channel in each first material strip and a second channel in each second material strip.
[0025] According to another feature, each first recessed shape or second recessed shape includes a main surface tilted relative to the connecting area, and also includes a first triangular side surface and a second triangular side surface arranged on both sides of the main surface, wherein the main surface of each first material strip abuts against and connects to the main surface of each second material strip.
[0026] According to another feature, the main face of each first recessed shape and second recessed shape includes a cutout configured to communicate the first chamber or the second chamber with a conduit. Attached Figure Description
[0027] Other features and advantages will become apparent from the following description of the invention, which is given by way of example only with reference to the accompanying drawings, in which:
[0028] Figure 1 This is a perspective view of a row of cells in a honeycomb structure, illustrating an embodiment of the prior art.
[0029] Figure 2 This is a top view illustrating a honeycomb structure of an embodiment of the prior art.
[0030] Figure 3 It is a schematic representation of a material strip formed according to a procedure of existing technology.
[0031] Figure 4 This is a side view of the aircraft.
[0032] Figure 5This is a perspective view of a main exhaust duct including at least one sound-absorbing covering layer, illustrating an application of the present invention.
[0033] Figure 6 This is a perspective view illustrating the sound-absorbing covering layer of an embodiment of the present invention.
[0034] Figure 7 This is a front view showing a material strip in a flat state according to the first embodiment of the present invention.
[0035] Figure 8 Is Figure 7 A portion of the material strip can be seen in the 3D model after bending.
[0036] Figure 9 This is a perspective view showing a portion of an assembly of two juxtaposed material strips according to a first embodiment of the present invention.
[0037] Figure 10 Is Figure 9 The side view of the component that can be seen in the image.
[0038] Figure 11 From such Figure 7 The top view of multiple rows of small cells obtained from the material strips shown in the image.
[0039] Figure 12 This is a front view showing a material strip in a flat state according to the second embodiment of the present invention.
[0040] Figure 13 Is Figure 12 A portion of the material strip can be seen in the 3D model after bending.
[0041] Figure 14 This is a perspective view showing a portion of an assembly of two juxtaposed material strips according to a second embodiment of the present invention.
[0042] Figure 15 Is Figure 14 The top view of the components that can be seen in the image.
[0043] Figure 16 Is Figure 14 The side view of the component that can be seen in the image.
[0044] Figure 17 From such Figure 12 The material strips shown are used to obtain a top view of multiple rows of small cells.
[0045] Figure 18 This is a perspective view showing multiple material strips of the second embodiment of the present invention before assembly, and
[0046] Figure 19 By assembling in Figure 18A three-dimensional image of a portion of the honeycomb structure obtained from the material strips can be seen in the image. Detailed Implementation
[0047] Figure 4 An aircraft 30 is depicted, which has propulsion units 32 fixed below its wings 34. Each propulsion unit 32 includes a nacelle 36 and a turbine 38 located within the nacelle 36.
[0048] According to Figure 5 As can be seen in the embodiment, the propulsion unit 32 includes a secondary exhaust duct 40 that guides the secondary airflow, the secondary exhaust duct being defined by an inner wall 42 (also referred to as IFS "internal fixed structure") and an outer wall 44 (also referred to as OFS "external fixed structure").
[0049] According to one configuration, the inner wall 42 or the outer wall 44 includes a sound-absorbing covering layer 46 (also referred to as a sound-absorbing panel).
[0050] Although described as being applied to the secondary exhaust duct 40, the invention is not limited to this application. Therefore, the sound-absorbing covering 46 can be positioned on any surface in contact with the medium through which sound waves propagate during operation, such as the lip and air intake of the aircraft nacelle, the fan housing of the aircraft nacelle, or any other surface of the propulsion unit 32. Regardless of configuration, the aircraft 30, and more specifically, one of the propulsion units 32 of the aircraft, includes at least one sound-absorbing covering 46.
[0051] According to Figure 6 As can be seen in the embodiment, the sound-absorbing covering layer 46 has an outer surface SE that contacts the medium in which sound waves propagate during operation and an inner surface SI opposite to the outer surface SE. The sound-absorbing covering layer 46, from the outer surface SE to the inner surface SI, includes a porous layer 48 (also referred to as a resistive layer), at least one honeycomb structure 50, and a reflective layer 52, one side of the porous layer forming the outer surface SE and one side of the reflective layer forming the inner surface SI. Thus, the porous layer 48 abuts against a first surface 50.1 of the honeycomb structure 50, and the reflective layer 52 abuts against a second surface 50.2 of the honeycomb structure 50 opposite to the first surface 50.1.
[0052] For the remainder of the description, the longitudinal direction is perpendicular to the first surface 50.1. The longitudinal plane encompasses the longitudinal direction. The transverse plane is a plane perpendicular to the longitudinal direction.
[0053] like Figure 11 , Figure 17 and Figure 19As shown, the cellular structure 50 includes multiple rows of cells 54 oriented in a first direction D1, and each row of cells alternately has a first cell 56 and a second cell 58. Each of the first cells has a first opening 56.1 leading to a first face 50.1 and a cross section that increases toward the first face 50.1. Each of the second cells has a second opening 58.1 leading to a second face 50.2 and a cross section that increases toward the second face 50.2.
[0054] The first chamber 56, which faces the porous layer 48 and opens to the first surface 50.1, is able to attenuate high frequencies, while the second chamber 58, which faces the reflective layer 52 and opens to the second surface 50.2, is able to attenuate low frequencies.
[0055] Each row of compartments 54 includes a first material strip 60 and a second material strip 62 placed abutting against each other. The first material strip 60 includes a first inner surface F60 oriented toward the second material strip 62 and a first outer surface F60' opposite to the first inner surface F60. The first material strip 60 also includes a first longitudinal side 60.1 and a second longitudinal side 60.2 that are parallel to each other, and the first longitudinal side 60.1 and the second longitudinal side 60.2 are respectively positioned on the first surface 50.1 and the second surface 50.2.
[0056] Meanwhile, the second material strip 62 includes a second inner surface F62 oriented toward the first material strip 60 and a second outer surface F62' opposite to the second inner surface F62. The second material strip 62 also includes a first longitudinal side 62.1 and a second longitudinal side 62.2 that are parallel to each other, and the first longitudinal side 62.1 and the second longitudinal side 62.2 are respectively positioned on the first surface 50.1 and the second surface 50.2.
[0057] Each first material strip 60 includes a first recessed shape 64, a second recessed shape 66, and a connecting region 68 separating the first recessed shape 64 and the second recessed shape 66, which alternate. The connecting region 68 is coplanar and positioned in a reference plane. Each first recessed shape 64 includes a first edge 64.1 positioned on a first longitudinal side 60.1, spaced apart from the reference plane, forming a first half of a first opening 56.1 of a first chamber 56. Each second recessed shape 66 includes a second edge 66.1 positioned on a second longitudinal side 60.2, spaced apart from the reference plane, forming a first half of a second opening 58.1 of a second chamber 58.
[0058] Each second material strip 62 includes a first recessed shape 70, a second recessed shape 72, and a connecting region 74 separating the first recessed shape 70 and the second recessed shape 72, which alternate. The connecting region 74 is coplanar and positioned in a reference plane. Each first recessed shape 70 includes a first edge 70.1 positioned at a first longitudinal side 60.1, spaced apart from the reference plane, forming a second half of a first opening 56.1 of a first chamber 56. Each second recessed shape 72 includes a second edge 72.1 positioned at a second longitudinal side 60.2, spaced apart from the reference plane, forming a second half of a second opening 58.1 of a second chamber 58.
[0059] To obtain a row of cells 54, the first material strip 60 and the second material strip 62 are placed abutting each other by means of adhesive bonding, welding, or any other assembly technique via connecting areas 68, 74. For this purpose, the first and second recessed shapes 64, 66, 70, 72 and the connecting areas 68, 74 are arranged such that the first cell 56 and the second cell 58 are formed when the first material strip 60 and the second material strip 62 are assembled.
[0060] The first material strip 60 and the second material strip 62 are identical. For each of the first material strip 60 and the second material strip 62, the first recessed shapes 64, 70 and the second recessed shapes 66, 72 are positioned relative to the transverse intermediate axis AMT (in) which is equidistantly located with respect to the first longitudinal side portions 60.1, 60.2; 62.1, 62.2 of the first material strip 60 and the second material strip 62. Figure 7 and Figure 12 Symmetry is visible in the middle.
[0061] According to one feature of the invention, the first recessed shape and the second recessed shape 64, 66, 70, 72 of the first material strip 60 and the second material strip 62 are obtained by bending.
[0062] Each of the first or second recessed shapes 64, 66, 70, 72 includes a main surface 76 and a first triangular side surface 78 and a second triangular side surface 78', which are arranged on both sides of the main surface 76 and connect the main surface 76 to one of the connecting areas 68, 74. The main surface 76 is separated from the first side surface 78 by a first main bend line 80 and from the second side surface 78' by a second main bend line 80'. Each connecting area 68, 74 is approximately rectangular. The first side surface 78 is separated from the first connecting area 68, 74 by a first primary bend line 82. The second side surface 78' is separated from the second connecting area 68, 74 by a second primary bend line 82'. The first primary bend line 82 and the second primary bend line 82' are perpendicular to the first longitudinal side and the second longitudinal side 60.1, 60.2, 62.1, 62.2.
[0063] For each of the first or second recessed shapes 64, 66, 70, 72, the first main bend line and the second main bend line 80, 80', the first-level bend line and the second-level bend line 82, 82' are symmetrical with respect to the longitudinal intermediate axis AML equidistant from the connecting areas 68, 74.
[0064] For the first recessed shapes 64 and 70 of the first material strip 60 and the second material strip 62, the first side 78 and the second side 78' each include a side located at the first longitudinal side portion 60.1 and 62.1. For the second recessed shapes 66 and 72 of the first material strip 60 and the second material strip 62, the first side 78 and the second side 78' each include a side located at the second longitudinal side portion 60.2 and 62.2.
[0065] The multiple rows of small cells 54 are arranged such that:
[0066] a. The main surface 76 of the first recessed shape 64 of the first material strip 60 in the first row abuts against the main surface 76 of the second recessed shape 72 of the second material strip 62 in the second row;
[0067] b. The main surface 76 of the second recessed shape 66 of the first material strip 60 in the first row abuts against the main surface 76 of the first recessed shape 70 of the second material strip 62 in the second row.
[0068] According to a specific feature of the invention, each first cell 56 in the first row of the cellular structure 50 includes a first conduit 84 that connects the first cell to a second cell 58 in the second row that is placed against the first cell 56, and each second cell 58 in the first row includes a second conduit 86 that connects the second cell to a first cell 56 in the second row that is placed against the second cell 58.
[0069] The first chamber 56 attenuates high frequencies and then transmits the sound to the second chamber 58, which attenuates low frequencies. The first chamber 56 and the second chamber 58 thus operate together.
[0070] Compared with existing technologies, the Helmholtz resonator is not obtained by connecting the first and second cells of the same row of cells, but by connecting the first cell of the first row of cells with the second cell of the second row of cells, or by connecting the second cell of the first row of cells with the first cell of the second row of cells.
[0071] According to one configuration, a first conduit 84 is located between the main surface 76 of the first recessed shape 64 of the first material strip 60 in the first row and the main surface 76 of the second recessed shape 72 of the second material strip 62 in the second row. A second conduit 86 is located between the main surface 76 of the second recessed shape 66 of the first material strip 60 in the first row and the main surface 76 of the first recessed shape 70 of the second material strip 62 in the second row.
[0072] According to a particular feature of the invention, each first conduit or second conduit 84, 86 includes a first channel 88 in a first material strip 60 and a second channel 90 in a second material strip 62, the first channel 88 and the second channel 90 being arranged such that when the first material strip 60 and the second material strip 62 are assembled, they interact to form the first conduit or second conduit 84, 86.
[0073] The first channel 88 and the second channel 90 are located on the main surface 76 of the first recessed shape and the second recessed shape 64, 66, 70, 72.
[0074] According to a specific feature of the invention, the first channel 88 and the second channel 90 are obtained by bending.
[0075] Each first channel or second channel 88, 90 includes a central bend 92 located at the longitudinal intermediate axis AML of each recessed shape 64, 66, 70, 72, and two inclined bends 94, 94' symmetrical with respect to the central bend 92 and intersecting at the central bend 92. Thus, for each first channel or second channel 88, 90, the central bend 92 corresponds to the base of the first channel or second channel 88, 90, and the inclined bends 94, 94' correspond to the edges of the first channel or second channel 88, 90. Regardless of the embodiment, each first channel or second channel 88, 90 includes bends 92, 94, 94' arranged such that the first channel 88 and the second channel 90 (of different material strips) form a first conduit or second conduit 84, 86 located between two abutting main surfaces 76.
[0076] Each main face 76 includes a cutout 96 configured to connect a first or second chamber 56, 58 to a first or second conduit 84, 86.
[0077] According to Figures 7 to 11 In the first embodiment that can be seen, the cut 96 is offset relative to the first longitudinal side and the second longitudinal side 60.1, 60.2; 62.1, 62.2 of the first material strip 60 and the second material strip 62.
[0078] According to Figures 12 to 19In the second embodiment that can be seen, the cut 96 intersects with one of the longitudinal sides of the first longitudinal side and the second longitudinal side 60.1, 60.2; 62.1, 62.2 of the first material strip 60 and the second material strip 62.
[0079] Multiple embodiments are conceivable for obtaining a first concave shape and a second concave shape 64, 66, 70, 72, as well as a first channel 88 and a second channel 90, by bending.
[0080] According to Figures 7 to 11 As can be seen in the first embodiment described with respect to the first material strip 60, the main surface 76 of the first recessed shape 64 has a trapezoidal shape and has a large base positioned at the second longitudinal side 60.2, and also has a small base positioned at the first longitudinal side 60.1. This main surface 76 has inclined bend lines 94, 94', which are spaced apart from the intermediate bend line 92 at the first longitudinal side 60.1 and converge at the second longitudinal side 60.2. The cutout 96 has a disc-shaped configuration positioned symmetrical with respect to the intermediate bend line 92 and close to the second longitudinal side 60.2.
[0081] Furthermore, the main surface 76 of the second recessed shape 66 has a trapezoidal shape and a large base positioned at the first longitudinal side 60.1, and a small base positioned at the second longitudinal side 60.2. This main surface 76 has inclined bend lines 94, 94', which are spaced apart from the intermediate bend line 92 at the second longitudinal side 60.2 and converge at the first longitudinal side 60.1. The cutout 96 has a disc-like shape positioned on the intermediate bend line 92 and close to the first longitudinal side 60.1.
[0082] According to this first embodiment, the first material strip 60 and the second material strip 62 are identical.
[0083] According to Figures 12 to 19 As can be seen in the second embodiment described with respect to the first material strip 60, the main surface 76 of the first recessed shape 64 has a trapezoidal shape and has a large base located at the second longitudinal side 60.2 and a small base located at the first longitudinal side 60.1. This main surface 76 has inclined bend lines 94, 94', which are spaced apart from the intermediate bend line 92 at the second longitudinal side 60.2 and converge at the first longitudinal side 60.1. The cutout 96 has a V-shape extending from the second longitudinal side 60.2, and the two sides of the V-shape are substantially parallel to the inclined bend lines 94, 94'.
[0084] Furthermore, the main surface 76 of the second recessed shape 66 has a trapezoidal shape and a large base located at the first longitudinal side 60.1, and a small base located at the second longitudinal side 60.2. This main surface 76 has inclined bend lines 94, 94', which are spaced apart from the intermediate bend line 92 at the first longitudinal side 60.1 and converge at the second longitudinal side 60.2. The cutout 96 has a V-shape extending from the first longitudinal side 60.1, and the two sides of the V-shape are substantially parallel to the inclined bend lines 94, 94'.
[0085] Of course, the invention is not limited to this embodiment for the first and second recessed shapes 64, 66, 70, 72. Therefore, each first or second material strip 60, 62 includes bends arranged such that each first or second recessed shape 64, 66, 70, 72 includes a main face 76 tilted relative to the connecting regions 68, 74, and such that when assembling the first and second material strips 60 and 62 to form the honeycomb structure 50, the main face 76 of the first material strip 60 abuts and connects to the main face 76 of the second material strip 62 by adhesive bonding, welding, or any other assembly technique.
[0086] According to one configuration, at least at one of the first longitudinal side portions 60.1, 60.2; 62.1, 62.2, the first material strip 60 and the second material strip 62 include a notch 98 (in... Figure 18 and Figure 19 (As can be seen), these notches cooperate from one material strip to another to form an emission network.
[0087] According to one embodiment, a method for manufacturing a honeycomb structure 50 includes a first step of forming a first material strip 60 and a second material strip 62 by bending to obtain a first recessed shape and a second recessed shape 64, 66, 70, 72 and also to obtain a first channel 88 and a second channel 90, and then includes a step of assembling the first material strip 60 and the second material strip 62 by abutting and connecting the connecting region 68 of the first material strip 60 to the connecting region 74 of the second material strip 62.
[0088] During this assembly step, the main surface 76 of the first recessed shape 64 of the first material strip 60 in the first row of chambers abuts against the main surface 76 of the second recessed shape 72 of the second material strip 62 in the second row of chambers. At the same time, the main surface 76 of the second recessed shape 66 of the first material strip 60 in the first row abuts against the main surface 76 of the first recessed shape 70 of the second material strip 62 in the second row.
[0089] During this assembly, the first channel 88 and the second channel 90 remain partially open to form the first pipe and the second pipe 84, 86.
[0090] According to one procedure, the assembly step may include a first sub-step of assembling each row of cells, followed by a second sub-step of assembling multiple rows of cells together. As a variation, it may be as follows: Figure 18 and Figure 19 The two sub-steps are executed simultaneously, as shown in the diagram.
[0091] Prior to the bending and shaping step, the method for manufacturing a honeycomb structure includes the step of making cuts 96 in a first and second material strip that are in a flat state.
[0092] Regardless of the embodiment, the first recessed shape and the second recessed shape 64, 66, 70, 72, as well as the first channel 88 and the second channel 90 of the first material strip 60 and the second material strip 62, are obtained by bending, which enables a wider range of choices of the material and thickness of the first material strip 60 and the second material strip 62.
[0093] like Figure 11 , Figure 17 and Figure 19 As shown, a third cell 57 is formed between two rows of cells 54, leading to the first surface 50.1 and the second surface 50.2 of the honeycomb structure 50. The third cell 57 is defined by the sides 78 and 78' of the concave shapes 64, 66, 70, and 72 of the connecting regions 68 and 74 and the first material strip 60 and the second material strip 62. These third cells 57 enable the attenuation of intermediate frequencies between high and low frequencies. These third cells 57 operate independently of the first cells 56 and the second cells 58.
Claims
1. A method for manufacturing a honeycomb structure (50), the honeycomb structure having a first face and a second face (50.1, 50.2), and further having multiple rows of cells (54), each row of cells alternately including a first cell (56) opening toward the first face (50.1) and a second cell (58) opening toward the second face (50.2), the honeycomb structure (50) also including a third cell (57) between each row of cells (54), the third cell opening toward the first face and the second face (50.1, 50.2); the method for manufacturing the honeycomb structure includes forming a first material strip and a second material strip (60, 62) by bending to obtain a first recessed shape and a second recessed shape for each first material strip and the second material strip (60, 62). The method further comprises the steps of obtaining connecting regions (68, 74) that separate the first and second recessed shapes (64, 66, 70, 72), wherein the first and second material strips (60, 62) are identical, and the method further comprises the steps of assembling the first and second material strips (60, 62) to form the honeycomb structure (50) by abutting and connecting the connecting regions (68) of the first material strip (60) to the connecting regions (74) of the second material strip (62), wherein the first and second recessed shapes (64, 66, 70, 72) are alternately arranged to form the first and second cells (56, 58) and also to form the third cell (57), wherein, During the step of forming the first and second material strips (60, 62) by bending, each first material strip (60) is formed by bending to obtain a first channel (88), and each second material strip (62) is formed by bending to obtain a second channel (90), the first and second channels (88, 90) forming the pipes (84, 86), each of the pipes connecting a pair of first and second chambers (56, 58).
2. The method for manufacturing a honeycomb structure (50) according to claim 1, wherein, Each first and second material strip (60, 62) includes a main bend line (80, 80') arranged such that each first and second recessed shape (64, 66, 70, 72) includes a main face (76) separated from a first triangular side and a second triangular side (78, 78') arranged on both sides of the main face (76), and each first and second material strip also includes a secondary bend line (82, 82') arranged such that each first and second side (78, 78') is separated from a connecting area (68, 74), the main face (76) being tilted relative to the connecting area (68, 74), and such that during the assembly step, the main face (76) of each first material strip (60) abuts against and connects to the main face (76) of the second material strip (62).
3. The method for manufacturing a honeycomb structure (50) according to claim 2, wherein, For each first recessed shape and second recessed shape (64, 66, 70, 72), the primary bend line (80, 80') and the secondary bend line (82, 82') are symmetrical with respect to the longitudinal intermediate axis (AML) equidistant from the connecting areas (68, 74) arranged on both sides of the first recessed shape and the second recessed shape (64, 66, 70, 72).
4. The method for manufacturing a honeycomb structure (50) according to any one of claims 2 and 3, wherein, The first channel and the second channel (88, 90) are positioned on the main surface (76) of the first recessed shape and the second recessed shape (64, 66, 70, 72), and each channel includes a bend (92, 94, 94') arranged such that each pair of first channels and second channels (88, 90) forms a conduit (84, 86) positioned between two abutting main surfaces (76).
5. The method for manufacturing a honeycomb structure (50) according to claim 4, wherein, Each first channel and second channel (88, 90) includes a central bend line (92), and also includes two inclined bend lines (94, 94') that are symmetrical with respect to the central bend line (92) and intersect at the central bend line (92).
6. The method for manufacturing a honeycomb structure (50) according to any one of claims 2 and 3, wherein, The manufacturing method includes, prior to the bending and forming step, making a cut (96) in the main surface of the first recessed shape and the main surface (76) of the second recessed shape of each of the first and second material strips (60, 62) in the flat state, each cut (96) configured to communicate a first or second chamber (56, 58) with a conduit (84, 86).
7. The method for manufacturing a honeycomb structure (50) according to claim 6, wherein, Each first material strip and second material strip (60, 62) includes a first longitudinal side and a second longitudinal side (60.1, 60.2, 62.1, 62.2), and the cut (96) is offset relative to the first longitudinal side and the second longitudinal side (60.1, 60.2, 62.1, 62.2) of the first material strip and the second material strip (60, 62).
8. The method for manufacturing a honeycomb structure (50) according to claim 6, wherein, Each first material strip and second material strip (60, 62) includes a first longitudinal side and a second longitudinal side (60.1, 60.2, 62.1, 62.2), and the cut (96) intersects with one of the longitudinal sides of the first longitudinal side and the second longitudinal side (60.1, 60.2, 62.1, 62.2) of the first material strip and the second material strip (60, 62).
9. A honeycomb structure (50) manufactured by the method according to any one of claims 1 to 8, the honeycomb structure having a first face and a second face (50.1, 50.2) and further having multiple rows of cells (54), each row of cells alternately including a first cell (56) opening toward the first face (50.1) and a second cell (58) opening toward the second face (50.2), the honeycomb structure (50) also including a third cell (57) between each row of cells (54), the third cell opening toward the first face and the second face (50.1, 50.2), each row of cells (54) including identical and abutting first and second material strips (60, 62), each first and second material strip (60, 62) being formed by bending. It also includes a first recessed shape (64, 70), a second recessed shape (66, 72), and a connecting region (68, 74) separating the first and second recessed shapes (64, 66, 70, 72), the first and second recessed shapes (64, 66, 70, 72) alternating and arranged to form the first and second cells (56, 58) and also forming the third cell (57); the honeycomb structure (50) also includes conduits (84, 86), each of which connects a pair of first and second cells (56, 58), each conduit (84, 86) including a first channel (88) in each first material strip (60) and also including a second channel (90) in each second material strip (62).
10. The honeycomb structure (50) according to claim 9, wherein, Each first or second recessed shape (64, 66, 70, 72) includes a main surface (76) tilted relative to the connecting area (68, 74), and also includes a first triangular side surface and a second triangular side surface (78, 78') arranged on both sides of the main surface (76), wherein the main surface (76) of each first material strip (60) abuts against and connects to the main surface (76) of each second material strip (62).
11. The honeycomb structure (50) according to claim 10, wherein, Each main face (76) of each of the first and second recessed shapes (64, 66, 70, 72) includes a cutout (96) configured to communicate a first or second chamber (56, 58) with a conduit (84, 86).
12. A sound-absorbing covering layer, the sound-absorbing covering layer comprising a porous layer, a reflective layer, and a honeycomb structure according to any one of claims 9 to 11, the honeycomb structure being disposed between the porous layer and the reflective layer.