Sound absorbing member

Abstract

The subject of the invention is a sound absorbing member comprising at least one honeycomb structure interposed between an acoustic resistive layer and a reflective layer, said at least one honeycomb structure comprising a plurality of cells (60) and at least one partition tube (62), at least one partition tube (62) is located in one of the plurality of cells (60) and is configured to define in the cell (60) two cavities forming two resonators, the partition tube (62) comprising at least two flat portions (72, 72 '), the wall defining the cell (60) into which the partition tube (62) is inserted comprising the flat portions (72, 72') of the partition tube (62). 72 '), and at least two partition walls spaced apart from the side wall of the partition tube (62).

Description

Technical Field

[0001] The present application relates to a sound absorption member including a honeycomb structural member and at least one partition tube having at least two flat portions connected to the walls of the honeycomb structural member. Background Art

[0002] According to an embodiment of the prior art, an aircraft propulsion assembly includes a nacelle and a twin - flow turbine located within the nacelle. The twin - flow turbine has a main injection duct at the rear, and the combustion exhaust gas generated by combustion is discharged through the main injection duct. The main injection duct includes a sound absorption member on its skin for attenuating noise in multiple frequency bands, such as noise related to combustion (300 to 1000 Hz) and noise related to turbine operation (greater than or equal to 4000 Hz).

[0003] According to a first embodiment, the sound absorption member includes at least one honeycomb structural member located between a sound resistance layer and a reflection layer, and the sound resistance layer is in contact with the medium in which sound waves propagate. This embodiment allows for obtaining a quarter - wavelength resonator suitable for attenuating high - frequency sound waves. According to this embodiment, the frequency range of attenuated sound waves depends on the height of the cells of the honeycomb structural member.

[0004] According to the second embodiment visible in Figure 1 and described in the document FR094668, the sound absorption member 10 includes a first honeycomb structural member 12 and a second honeycomb structural member 14 located between a sound resistance layer 16 and a reflection layer 18, and the sound resistance layer 16 is in contact with the medium in which sound waves propagate. The sound absorption member 10 includes a separation layer 20 inserted between the first honeycomb structural member 12 and the second honeycomb structural member 14. The first honeycomb structural member 12 is inserted between the sound resistance layer 16 and the separation layer 20, and the second honeycomb structural member 14 is inserted between the reflection layer 18 and the separation layer 20.

[0005] According to this second embodiment, the separation layer 20 includes holes 22 for communicating the cells of the first honeycomb structural member 12 with the cells of the second honeycomb structural member 14, and each hole 22 is extended by a tube 24 located in the second honeycomb structural member 14.

[0006] The sound absorption member 10 is capable of obtaining two types of resonators: a first resonator of Helmholtz type located at the cells of the first honeycomb structural member 12, which is suitable for attenuating low - frequency sound waves, and a second resonator of quarter - wavelength type located at the cells of the second honeycomb structural member 14, which is suitable for attenuating high - frequency sound waves.

[0007] According to this second embodiment, each tube 24 is connected to the separation layer by a connecting member 24.1, and then the first honeycomb structural member 12 and the second honeycomb structural member 14 are connected to the separation layer 20 by connecting members 12.1, 14.1. The cells of the first honeycomb structural member 12 and the second honeycomb structural member 14 must be perfectly aligned such that each cell of the first honeycomb structural member 12 communicates only with a single cell of the second honeycomb structural member 14.

[0008] Even though this second embodiment allows for weakening sound waves over a wider frequency range, it is not entirely satisfactory because a large number of connecting members result in an increase in the mass of the sound-absorbing member 10 and complicate its manufacturing process. The latter is more complex to implement because the cells of the first honeycomb structural member and the second honeycomb structural member must be perfectly aligned to obtain optimal functionality. According to another drawback, such a sound-absorbing member requires at least two drainage systems, one for each of the first honeycomb structural member 12 and the second honeycomb structural member 14, which tends to complicate the sound-absorbing member. Finally, in view of the connecting members 12.1, 14.1 that connect the ends of the walls defining the cells of the first honeycomb wall 12 and the second honeycomb wall 14 to the separation layer 20, forming the curved profile of the sound-absorbing member 10 has proven to be difficult. Summary of the Invention

[0009] The present invention aims to overcome all or part of the drawbacks of the prior art.

[0010] To this end, the subject of the present invention is a sound-absorbing member comprising at least one honeycomb structural member inserted between a sound resistance layer and a reflection layer, said at least one honeycomb structural member comprising a first face in contact with the sound resistance layer, a second face in contact with the reflection layer, and a plurality of cells, each cell being open at the first face and the second face, and each cell being defined by walls.

[0011] According to the present invention, the honeycomb structural member comprises at least one partition tube located in one of the cells, said at least one partition tube comprising a first conduit extending between a first end and a second end and having a first cross-section between the first end and the second end, a second conduit extending between the first end and the second end and having a second cross-section between the first end and the second end, and a connecting wall connecting the second ends of the first conduit and the second conduit, the second cross-section being smaller than the first cross-section; the first end of the first conduit is closed by the first layer of the sound resistance layer and the reflection layer, and the first end of the second conduit is spaced apart from the second layer different from the first layer of the sound resistance layer and the reflection layer. In addition, the first conduit of the partition tube comprises at least two flat portions and at least one side wall, and the walls defining the cell in which the partition tube is inserted comprise at least a first fixed wall and a second fixed wall against which the flat portions of the partition tube are pressed and fixed and at least two spacer walls spaced apart from the side wall of the partition tube, the first fixed wall and the second fixed wall being planar.

[0012] This solution allows for obtaining a cellular structural member that includes two types of resonators configured to attenuate sound waves over a wide frequency band or multiple frequency bands. The fact of providing a dividing tube that includes at least two flat portions fixed to the first and second planar walls of the cell simplifies the fixing of the dividing tube, provides better strength for the connection between the dividing tube and the cellular structural member, and allows the cellular structural member to maintain a certain flexibility for shaping it.

[0013] According to another feature, the sound-absorbing member includes at least one first drainage network and at least one second drainage network. The at least one first drainage network includes a first opening and a second opening passing through the first and second fixed walls, and the at least one second drainage network includes a third opening and a fourth opening passing through the third and fourth walls opposite the first and second fixed walls.

[0014] According to another feature, each wall of the cell in which the dividing tube is located includes a first end edge and a second end edge located at the positions of the first and second faces of the cellular structural member. In addition, the first opening, the second opening, the third opening, and the fourth opening are located at the position of the first end edge or the second end edge where the first end of the first conduit of the dividing tube in the wall is positioned.

[0015] According to another feature, the dividing tube includes at least one notch extending from the first end of the first conduit, and the at least one notch is configured to release at least the first opening and the second opening when the dividing tube is fixed to the first and second fixed walls.

[0016] According to another feature, the dividing tube includes a single notch that releases the first opening and the second opening.

[0017] According to another feature, the notch is defined by a first edge and second and third edges connecting the first edge to the upper end of the first conduit, and the second and third edges are away from the side wall.

[0018] According to another feature, the first and second fixed walls are connected by a common side edge, and the dividing tube includes an intermediate region separating the two flat portions, and the intermediate region is spaced apart from the common side edge of the first and second fixed walls.

[0019] According to another feature, each flat portion extends from the first end to the second end of the first conduit.

[0020] According to another feature, the side wall includes two planar portions parallel to each other and connected to the flat portion, and a curved portion connecting the two planar portions, and the planar portion and the curved portion of the side wall are spaced apart from the wall of the cell in which the dividing tube is located.

[0021] According to another feature, on a given area, each cell of the honeycomb structural member includes a partition tube connected to a first fixed wall and a second fixed wall, the first fixed wall and the second fixed wall are penetrated by a first opening and a second opening, and are spaced apart from a third wall and a fourth wall that are opposite to the first fixed wall and the second fixed wall and are penetrated by a third opening and a fourth opening. In addition, the first fixed wall and the second fixed wall of the cell are connected to each other so as to form at least one first broken line in a top view, the partition tube is located on both sides of the first broken line and is connected to the first fixed wall and the second fixed wall, and wherein the third wall and the fourth wall of the cell are connected to each other so as to form at least one second broken line spaced apart from the first broken line in a top view. Description of the Drawings

[0022] 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:

[0023] - Figure 1 is a schematic cross-sectional view showing an acoustic absorption member of a prior art embodiment,

[0024] - Figure 2 is a side view of an aircraft,

[0025] - Figure 3 is a longitudinal cross-sectional view of a part of an aircraft propulsion assembly,

[0026] - Figure 4 is a longitudinal cross-sectional view showing a part of an acoustic absorption member of an embodiment of the present invention,

[0027] - Figure 5 is a longitudinal cross-sectional view showing a part of an acoustic absorption member of another embodiment of the present invention,

[0028] - Figure 6 is a schematic view showing the respective steps of a manufacturing method of an acoustic absorption member of an embodiment of the present invention,

[0029] - Figure 7 is a schematic view showing the respective steps of a manufacturing method of an acoustic absorption member of another embodiment of the present invention,

[0030] - Figure 8 is a side view showing a notchless partition tube of an embodiment of the present invention,

[0031] - Figure 9 is Figure 8 a perspective view of the partition tube visible in

[0032] - Figure 10 is showing, in an embodiment of the present invention, the Figure 8 top view of the partition tube visible in the cell of the honeycomb structural member,

[0033] -Figure 11 is a side view showing a part including two separating tubes according to an embodiment of the present invention,

[0034] - Figure 12 is a side view showing a separating tube according to an embodiment of the present invention,

[0035] - Figure 13 is Figure 12 a perspective view of the separating tube visible in

[0036] - Figure 14 is a perspective view showing a unit and a separating tube of a honeycomb structural member before and after assembly according to an embodiment of the present invention,

[0037] - Figure 15 is a perspective view showing a plurality of units and a plurality of separating tubes of a honeycomb structural member during the assembly process according to an embodiment of the present invention,

[0038] - Figure 16 is a perspective view showing a part of a honeycomb structural member according to an embodiment of the present invention. Detailed Description

[0039] Figure 2 shows an aircraft 30 having a fuselage 32, two wings 34 disposed on both sides of the fuselage 32, and a propulsion assembly 36 fixed below the wings 34. Each propulsion assembly 36 includes a nacelle 38 and a turbine 40 located within the nacelle 38.

[0040] According to Figure 3 the embodiment shown, the turbine 40 includes a main jet duct 42 at the rear, through which combustion gases in the turbine 40 escape. The main jet duct 42 is externally defined by an outer wall 44 and internally defined by an inner wall 46 extending through a nozzle cone 48.

[0041] According to one configuration, the outer wall 44 and the inner wall 46 each include at least one sound-absorbing member 50.

[0042] Each sound-absorbing member 50 includes an outer surface SE in contact with the medium in which sound waves propagate and an inner surface SI opposite to the outer surface SE.

[0043] Although described as being applied to the main jet duct 42, the present invention is not limited to this application. Thus, the sound-absorbing member 50 can be positioned at a location on a wall having an outer surface SE in contact with the medium in which sound waves propagate.

[0044] Each sound-absorbing member 50 includes at least one honeycomb structural member 52 inserted between a sound impedance layer 54 through which sound waves can pass and a reflection layer 56 through which sound waves cannot pass. The sound impedance layer 54 has a first surface 54.1 corresponding to the outer surface SE and a second surface 54.2 facing the honeycomb structural member 52 and connected to the honeycomb structural member 52. The reflection layer 56 has a first surface 56.1 corresponding to the inner surface SI and a second surface 56.2 facing the honeycomb structural member 52 and connected to the honeycomb structural member 52.

[0045] The sound impedance layer 54, the reflection layer 56, the connecting member between the sound impedance layer 54 and the honeycomb structural member 52, and the connecting member between the reflection layer 56 and the honeycomb structural member 52 will not be described further because they can be the same as those in the prior art.

[0046] The honeycomb structural member 52 extends between a first surface 52.1 in contact with the sound impedance layer 54 and a second surface 52.2 in contact with the reflection layer 56, and includes a plurality of substantially rectangular walls 58.1 to 58.6. Each of the plurality of walls 58.1 to 58.6 has a first edge and a second edge located at positions on the first surface 52.1 and the second surface 52.2, respectively. These walls 58.1 to 58.6 are connected to each other to define a cell 60 that is open at the first surface 52.1 and the second surface 52.2.

[0047] According to one embodiment, the honeycomb structural member 52 is a honeycomb-like structure. As Figure 10 shown, each cell 60 is defined by six walls 58.1 to 58.6 and has a hexagonal cross-section with six identical sides of width L60. Each hexagonal cell 60 includes an inscribed circle diameter D60 of the cell. The cell diameter D60 is between 9.6 mm and 19.1 mm. Each cell 60 has a cell height H60 corresponding to the spacing distance between the first surface 52.1 and the second surface 52.2 (visible in Figure 14 ). The cell height H60 is between 30 mm and 70 mm. The length of each rectangular wall 58.1 to 58.6 is equal to the cell height H60, and the length of each rectangular wall 58.1 to 58.6 is between 30 mm and 70 mm and the width is between about 5 mm and 12 mm.

[0048] Of course, for the cell 60, the present invention is not limited to this embodiment. Each of the cells is open at a first end and a second end respectively closed by the sound impedance layer 54 and the reflection layer 56. Each of the cells is defined by planar walls 58.1 to 58.6, two of which are fixed walls 58.1, 58.2.

[0049] The honeycomb structural member 52 includes at least one partition tube 62 located in a cell 60. According to one configuration, the honeycomb structural member 52 includes a plurality of partition tubes 62 each located in a cell 60. According to one arrangement, in at least one region of the honeycomb structural member 52, the honeycomb structural member 52 includes one partition tube 62 in each cell 60, as Figure 4 and Figure 5 shown.

[0050] As Figure 8 and Figure 10 shown, each partition tube 62 includes a first conduit 64 extending between a first end 64.1 and a second end 64.2 and having a first cross-section S1 between the first end 64.1 and the second end 64.2, a second conduit 66 extending between a first end 66.1 and a second end 66.2 and having a second cross-section S2 between the first end 66.1 and the second end 66.2, the second cross-section S2 being smaller than the first cross-section S1, and a connecting wall 68 connecting the second ends 64.2, 66.2 of the first conduit 64 and the second conduit 66. According to one configuration, the second cross-section S2 is 25% smaller than the first cross-section S1, preferably 15% smaller.

[0051] Each partition tube 62 is integrally formed, and the first conduit 64, the second conduit 66, and the connecting wall 68 are formed in the same manufacturing step.

[0052] According to one embodiment, the first cross-section S1 is constant along a first height H1 between the first end 64.1 and the second end 64.2. Thus, the first conduit 64 has a first axis A64. The first height H1 is between 1 mm and 20 mm. According to one arrangement, the first height H1 is between 25% and 75% of the cell height H60. According to one configuration, the first height H1 is substantially equal to half of the cell height H60.

[0053] According to one embodiment, the second cross-section S2 is constant along a second height H2 between the first end 66.1 and the second end 66.2. Thus, the second conduit 66 has a second axis A66. According to one embodiment, the second cross-section S2 is circular. According to one configuration, the second cross-section S2 is between 0.15 mm 2 and 20 mm 2 corresponding to diameters of approximately 0.5 mm and 5 mm, respectively. The second height H2 is between 10 mm and 25 mm.

[0054] According to one arrangement, the first axis A64 and the second axis A66 are aligned.

[0055] According to one embodiment, the connecting wall 68 is located in a plane perpendicular to the first axis A64, i.e., substantially perpendicular to the first duct 64. Of course, the present invention is not limited to this embodiment for the connecting wall 68. The connecting wall 68 may not be planar, but for example, frustoconical.

[0056] According to Figure 4 In the first embodiment shown, the first end 64.1 of the first duct 64 is located at the position of the first face 52.1 of the honeycomb structure 52 so as to be enclosed by the acoustic impedance layer 54 and connected to the acoustic impedance layer 54 in a sealed manner. The first end 66.1 of the second duct 66 is spaced from the reflection layer 56 and the second face 52.2 of the honeycomb structure 52 by a distance between 0.5 mm and 70% of the cell height H60.

[0057] According to Figure 5 In the second embodiment shown, the first end 64.1 of the first duct 64 is positioned at the level of the first face 52.2 of the honeycomb structure 52 so as to be enclosed by the reflection layer 56 and connected to the reflection layer 56 in a sealed manner. The first end 66.1 of the second duct 66 is spaced from the acoustic impedance layer 54 and the first face 52.1 of the honeycomb structure 52 by a distance between 0.5 mm and 70% of the honeycomb height H60.

[0058] Regardless of the embodiment, the partition duct 62 divides the cell 60 in which it is located into a first cavity 70.1 and a second cavity 70.2. The first cavity 70.1 is located inside the partition duct 62 and is defined by the partition duct 62 and the first of the acoustic impedance layer 54 and the reflection layer 56. The second cavity 70.2 is located outside the partition duct 62 and is defined by the walls 58.1 to 58.6 of the honeycomb structure 52, the partition duct 62, the reflection layer 56, and the acoustic impedance layer 54. The first cavity 70.1 and the second cavity 70.2 communicate via the second duct 66. Thus, one of the cavities 70.1, 70.2 forms a first Helmholtz-type resonator adapted to attenuate low-frequency sound waves. In addition, the other of the cavities 70.1, 70.2 forms a second quarter-wavelength-type resonator adapted to attenuate high-frequency sound waves.

[0059] This solution allows to obtain an acoustic absorption member configured to attenuate sound waves in a wide frequency band or multiple frequency bands.

[0060] According to Figure 4 In the embodiment shown, the first cavity 70.1 forms a first Helmholtz-type resonator adapted to attenuate low-frequency sound waves. In addition, the second cavity 70.2 forms a second quarter-wavelength-type resonator adapted to attenuate high-frequency sound waves.

[0061] According to Figures 12 to 16The specific features of the present invention shown, the first conduit 64 of the separating tube 62 includes at least two flat portions 72, 72' which are at least in close contact with and fixed to adjacent first and second fixed walls 58.1, 58.2 among the walls 58.1 to 58.6 of the unit 60, and at least one side wall 74 spaced apart from the other walls 58.3 to 58.6 of the unit 60, which is called a spacer wall.

[0062] According to the nature of the elements to be assembled, each flat portion 72, 72' is fixed to the fixed walls 58.1, 58.2 by any suitable means such as gluing, welding, snapping or other means.

[0063] According to one configuration, each flat portion 72, 72' extends from the first end 64.1 to the second end 64.2 over the entire height of the first conduit 64.

[0064] According to one embodiment, each of the walls 58.1 to 58.6 of the unit 60 includes a first end edge 58a located at the position of the second face 52.2 of the honeycomb member 52, a second end edge 58b located at the position of the first face 52.1 of the honeycomb member 52, and side edges 58c, 58d connecting the first end edge 58a and the second end edge 58b. The first fixed wall 58.1 and the second fixed wall 58.2 are connected by a common side edge 58c.

[0065] The unit 60 has a hexagonal cross-section, and the fixed walls 58.1, 58.2 form an angle of 120° with each other. In addition, the flat portions 72, 72' form an angle of about 120° with each other so as to be in close contact with the first fixed wall 58.1 and the second fixed wall 58.2. The width of each flat portion 72, 72' is less than the width of the corresponding first fixed wall 58.1 or second fixed wall 58.2.

[0066] Each side wall 74 is spaced from the spacer walls 58.3 to 58.6 of the unit 60 by a substantially constant distance. According to one embodiment, the side wall 74 includes two planar portions 74.1, 74.2 parallel to each other and connected to the flat portions 72, 72', and a curved portion 74.3 connecting the two planar portions 74.1, 74.2.

[0067] According to one arrangement, the curved portion 74.3 of the side wall 74 is a cylindrical portion having an axis coinciding with the first axis A64 of the first conduit 64.

[0068] Each flat portion 72, 72' forms an angle of about 120° with the planar portions 74.1, 74.2 of the adjacent side wall 74.

[0069] The planar and curved portions 74.1, 74.2, 74.3 of the side wall 74 are spaced from the third, fourth, fifth, and sixth partition walls 58.3 to 58.6 facing them by a distance between 5% and 50% of the diameter D60 of the inscribed circle in the first cross-section S1.

[0070] According to one configuration, the separating tube 62 includes an intermediate region 76 that separates two flat portions 72, 72'. The intermediate region 76 is spaced from the side edge 58c common to the first fixed wall 58.1 and the second fixed wall 58.2. According to one arrangement, the intermediate region 76 is planar and extends from the first end 64.1 to the second end 64.2 over the entire height of the first conduit 64. The intermediate region 76 forms an angle of the order of 150° with each flat portion 72, 72' and has a width of the order of a few millimeters (dimension perpendicular to the first end 64.1), which is less than half the width of the flat portions 72, 72'.

[0071] According to the present invention, the separating tube 62 is connected to at least two fixed walls 58.1, 58.2 of the unit 60 in which the separating tube 62 is located and is connected to at most four partition walls 58.3 to 58.6. Thus, the unit 60 includes at least the first fixed wall 58.1 and the second fixed wall 58.2 adjacent to which the separating tube 62 is connected, and at least two partition walls 58.3 to 58.6 spaced from the separating tube 62. As long as the separating tube 62 is not connected to all the walls 58.1 to 58.6 of the unit 60, the honeycomb structure 52 retains a certain flexibility. Thus, the honeycomb structure 52 retains the flexibility that allows it to be shaped. The flexibility of the honeycomb structure 52 increases as the number of walls to which the separating tube 62 is connected decreases.

[0072] According to Figure 6 the first embodiment shown, the method of manufacturing the sound-absorbing member includes: the step of manufacturing the honeycomb structure 52 including the first plane 52.1 and the second plane 52.2, as Figure 6 shown in part (A) of Figure 6 the step of disposing the sound resistance layer 54 on the first face 52.1 of the honeycomb structure 52, as Figure 6 shown in part (B) of Figure 6 the step of inserting each separating tube 62 into the unit 60, as

[0073] According to Figure 7The second embodiment shown includes the steps of manufacturing a honeycomb structural member 52 including a first plane 52.1 and a second plane 52.2, such as Figure 7 the step of disposing a reflective layer 56 on the second face 52.2 of the honeycomb structural member 52 as shown in part (A) of Figure 7 the step of inserting each partition tube 62 into a unit 60 as shown in part (B) of Figure 7 the step of fixing the partition tube 62 inserted into the unit 60 to at least two fixed walls 58.1, 58.2 of the unit 60, possible steps of forming the honeycomb structural member 52, and such as Figure 7 the step of disposing an acoustic resistance layer 54 on the first face 52.1 of the honeycomb structural member 52 as shown in part (D) of

[0074] According to another embodiment, a method of manufacturing an acoustic absorption member includes the steps of manufacturing a honeycomb structural member 52 including a first plane 52.1 and a second plane 52.2, the step of inserting each partition tube 62 into a unit 60, the step of fixing the partition tube 62 inserted into the unit 60 to at least two fixed walls 58.1, 58.2 of the unit 60, the step of forming the honeycomb structural member 52, and the step of disposing the acoustic resistance layer 54 and the reflective layer 56 after the step of fixing the partition tube 62 to the unit 60 of the honeycomb structural member 52.

[0075] The step of inserting the partition tubes 62 can be carried out uniformly, one partition tube after another, or multiple partition tubes can be inserted simultaneously.

[0076] The step of inserting the partition tubes 62 can be mechanized and / or carried out before or after the forming step.

[0077] According to one mode of operation, during the step of fixing each partition tube 62, at least one centering element is used to keep the partition tube 62 spaced apart from the spacer walls 58.3 to 58.6.

[0078] According to one embodiment, the honeycomb structural member 52 can be a metal or a composite material. The partition tubes 62 can be made of metal, composite material, or plastic material.

[0079] When they are made of plastic material, the partition tubes 62 can be produced by, for example, blow molding, injection molding, or stamping processes.

[0080] According to one mode of operation, the manufacturing method includes the step of cutting out at least one partition tube in a part 78.

[0081] Therefore, as Figure 11As shown, two separating tubes 62, 62' can be cut out from the same part 78 made integrally. This part 78 includes a central section 80 having the same cross-section as the first conduits 64 of each separating tube 62, 62', and two secondary sections 82, 82' located on both sides of the central section 80 and extending along the central section 80. Each secondary section 82, 82' has the same cross-section as the second conduits 66 of each separating tube 62, 62'. The length L80 of the central section 80 is greater than the sum of the lengths of the two first conduits 64. Thus, the central section 80 includes the two first conduits 64 of the two separating tubes 62, 62' and an additional length 80.1. In addition, the lengths L82, L82' of each secondary section 82, 82' are greater than the length of the second conduit 66 of the separating tubes 62, 62'. Thus, each secondary section 82, 82' includes the second conduit 66 of the separating tubes 62, 62' and additional lengths 82.1, 82.1'. According to this embodiment, two separating tubes 62, 62' can be cut out from a single part 78 made integrally, and each separating tube 62, 62' has a first conduit 64 of a suitable length, which can be different for each separating tube. In addition, two secondary sections 82, 82' can be cut to adjust the length of the second conduit 66 of each separating tube 62, 62'.

[0082] Of course, the present invention is not limited to this production method for repairing tubes.

[0083] According to Figure 16 a feature of the present invention as shown, the sound-absorbing member 50 includes at least one first drainage network 84 intersecting with a first cavity 70.1 inside the separating tube 62 located in a given unit 60, and at least one second drainage network 86 intersecting with a second cavity 70.2 located outside the separating tube 62 and between the separating tube 62 and the unit 60.

[0084] The first drainage network 84 includes a first opening 84.1 and a second opening 84.2 passing through the first fixed wall 58.1 and the second fixed wall 58.2 at the position of the unit 60. In addition, the second drainage network 86 includes a third opening 86.1 and a fourth opening 86.2 passing through a third wall 58.3 and a fourth wall 54.4 opposite to the first fixed wall 58.1 and the second fixed wall 58.4 at the position of the unit 60. The first opening 84.1, the second opening 84.2, the third opening 86.1, and the fourth opening 86.2 are located at the position of the first end edge 58a or the second end edge 58b where the first end 64.1 of the first conduit 64 of the separating tube 62 of the walls 58.1 to 58.6 is located.

[0085] To ensure the continuity between the first opening 84.1 and the second opening 84.2, the partition tube 62 includes at least one notch 88 extending from the first end 64.1 of the first conduit 64, and the notch 88 is configured to at least release the first opening 84.1 and the second opening 84.2 when the partition tube 62 is fixed to the first fixed wall 58.1 and the second fixed wall 58.2. According to the first configuration, the partition tube 62 includes two notches, one notch for each of the first opening 84.1 and the second opening 84.2. According to Figure 9 and Figures 12 to 16 the second configuration visible in, the partition tube 62 includes a single notch 88 that releases the first opening 84.1 and the second opening 84.2 and extends over two flat portions 72, 72' and an intermediate region 76. The notch 88 is defined by a first edge 88.1 that is substantially parallel to the first end 64.1 of the first conduit 64, and a second edge 88.2 and a third edge 88.3 that are substantially perpendicular to the upper end 64.1, and the second edge 88.2 and the third edge 88.3 connect the first end 64.1 and the first edge 88.1, are close to two planar portions 74.1, 74.2 of the side wall 74 and are away from the side wall 74. The notch 88 is away from the side wall 74, particularly away from the two planar portions 74.1, 74.2 of the side wall 74. Thus, each of the flat portions 72, 72' includes a strip of material 72.1 that extends to the first end 64.1 of the first conduit 64 such that the two strips of material 72.1 of the flat portions 72, 72' are in close contact with and fixed to the first fixed wall 58.1 and the second fixed wall 58.2 until the first end 64.1 is on both sides of the notch 88.

[0086] The fact that the partition tube 62 is connected to the first fixed wall 58.1 and the second fixed wall 58.2 and includes at least one notch 88 that releases the first opening 84.1 and the second opening 84.2 preset at the first fixed wall 58.1 and the second fixed wall 58.2 allows the first drainage network 84 to be isolated from the second drainage network 86.

[0087] According to one embodiment, in a given area, each cell 60 of the honeycomb structural member 52 includes a partition tube 62. The first fixed wall 58.1 and the second fixed wall 58.2 are connected to each other such that at least one first fold line 90 is formed in a top view. Parallelly, the third wall 58.3 and the fourth wall 58.4 are connected to each other such that at least one second fold line 92 is formed in a top view, the second fold line 92 is spaced apart from the first fold line 90, and is connected to the first fold line 90 by a fifth wall 58.5 and a sixth wall 58.6 that are parallel to each other and have no cuts.

[0088] The partition tubes 62 are located on both sides of the first fold line 90 and are connected to the first fixed wall 58.1 and the second fixed wall 58.2. Accordingly, each of the first fixed wall 58.1 and the second fixed wall 58.2 is connected to two partition tubes 62 located on both sides of the fixed walls 58.1, 58.2.

[0089] According to this embodiment, the honeycomb structural member 52 includes a plurality of first drainage networks 84, each first drainage network 84 being located on either side of the first fold line 90 and including a first opening 84.1 and a second opening 84.2 preset at the first fixed wall 58.1 and the second fixed wall 58.2 forming the first fold line 90 and a first cavity 70.1 connecting to the partition tubes 62 connected to the first fixed wall 58.1 and the second fixed wall 58.2 forming the first fold line 90. In addition, the honeycomb structural member 52 includes a plurality of second drainage networks 86, each second drainage network 86 being located on either side of the second fold line 92 and including a third opening 86.1 and a fourth opening 86.2 preset at the third wall 58.3 and the fourth wall 58.4 forming the second fold line 92 and a second cavity 70.2 of the unit 60 located on either side of the second fold line 92.

[0090] According to an operating mode, a method of manufacturing the acoustic honeycomb structural member 52 includes at least one grooving step for manufacturing the openings 84.1, 84.2, 86.1, 86.2 of the first drainage network 84 and the second drainage network 86. This grooving step is performed before the step of inserting the partition tubes 62 and the steps of setting the acoustic resistance layer 54 and the reflective layer 56.

[0091] Of course, the present invention is not limited to these embodiments of the first drainage network 84 and the second drainage network 86.

Claims

1. An acoustic absorption member, comprising at least one honeycomb structural member (52) inserted between a sound resistance layer (54) and a reflection layer (56), the honeycomb structural member (52) comprising a first surface (52.1) in contact with the sound resistance layer (54), a second surface (52.2) in contact with the reflection layer (56), and a plurality of cells (60), each cell (60) being open at the first and second surfaces (52.1, 52.2), each cell (60) being defined by walls (58.1 to 58.6); characterized in that, The honeycomb structural member (52) includes at least one partition tube (62) located in one of the cells (60). The partition tube (62) includes a first conduit (64) extending between a first end and a second end (64.1, 64.2) and having a first cross-section (S1) between the first end and the second end (64.1, 64.2), a second conduit (66) extending between the first end and the second end (66.1, 66.2) and having a second cross-section (S2) between the first end and the second end (66.1, 66.2), and a connecting wall (68) connecting the second ends (64.2, 66.2) of the first conduit and the second conduit (64, 66). The second cross-section (S2) is smaller than the first cross-section (S1). The first end (64.1) of the first conduit (64) is closed by the first layer of the acoustic impedance layer (54) and the reflective layer (56). The first end (66.1) of the second conduit (66) is spaced apart from the second layer different from the first layer of the acoustic impedance layer (54) and the reflective layer (56). The first conduit (64) of the partition tube (66) includes at least two flat portions (72, 72') and at least one side wall (74). The walls (58.1 to 56.6) of the cell (60) in which the partition tube (62) is inserted include at least a first fixed wall and a second fixed wall (58.1, 58.2) against which the flat portions (72, 72') of the partition tube (62) are closely attached and fixed, and at least two spaced walls (58.3 to 58.6) spaced apart from the side wall (74) of the partition tube (62). The first fixed wall and the second fixed wall (58.1, 58.2) are planar.

2. The sound-absorbing member according to claim 1, characterized in that, The sound-absorbing member includes at least one first drainage network (84) and at least one second drainage network (86). The at least one first drainage network (84) includes a first opening and a second opening (84.1, 84.2) passing through the first fixed wall and the second fixed wall (58.1, 58.2). The at least one second drainage network (86) includes a third opening and a fourth opening (86.1, 86.2) passing through a third wall and a fourth wall (58.3, 54.4) opposite to the first fixed wall and the second fixed wall (58.1, 58.4).

3. The sound-absorbing member according to the previous claim, characterized in that, Each wall (58.1 to 58.6) of the unit (60) in which the dividing tube (62) is located includes a first end edge and a second end edge (58a, 58b) at positions on the first and second faces (52.1, 52.2) of the honeycomb structure (52), and the first opening, second opening, third opening, and fourth opening (84.1, 84.2, 86.1, 86.2) are located at positions on the first end edge or the second end edge (58a, 58b) where the first end (64.1) of the first conduit (64) of the dividing tube (62) in the wall (58.1 to 58.6) is positioned.

4. The sound-absorbing member according to the preceding claim, characterized in that, The dividing tube (62) includes at least one notch (88) extending from the first end (64.1) of the first conduit (64), and the notch (88) is configured to release at least the first opening and the second opening (84.1, 84.2) when the dividing tube (62) is fixed to the first fixed wall and the second fixed wall (58.1, 58.2).

5. The sound-absorbing member according to the previous claim, characterized in that, The dividing tube (62) includes a single notch (88) that releases the first opening and the second opening (84.1, 84.2).

6. The sound-absorbing member according to the previous claim, characterized in that, The notch (88) is defined by a first edge (88.1) and second and third edges (88.2, 88.3) connecting the first edge (88.1) to the upper end (64.1) of the first conduit (64), and the second and third edges (88.2, 88.3) are away from the side wall (74).

7. The sound-absorbing member according to one of the preceding claims, characterized in that, The first fixed wall and the second fixed wall (58.1, 58.2) are connected by a common side edge (58c), and the dividing tube (62) includes an intermediate region (76) separating the two flat portions (72, 72'), and the intermediate region (76) is spaced apart from the common side edge (58c) of the first fixed wall and the second fixed wall (58.1, 58.2).

8. The sound-absorbing member according to one of the preceding claims, characterized in that, Each of the flat portions (72, 72') extends from the first end (64.1) of the first conduit (64) to the second end (64.2).

9. The sound-absorbing member according to one of the claims, characterized in that, The side wall (74) includes two planar portions (74.1, 74.2) that are parallel to each other and connected to the flat portions (72, 72'), and a curved portion (74.3) connecting the two planar portions (74.1, 74.2), and the planar and curved portions (74.1, 74.2, 74.3) of the side wall (74) are spaced apart from the walls (58.3 to 58.6) of the unit (60) in which the dividing tube (62) is located.

10. The sound-absorbing member according to one of the preceding claims, characterized in that, In a given area, each cell (60) of the honeycomb structural member (52) includes a partition tube (62) connected to the first fixed wall and the second fixed wall (58.1, 58.2), the first fixed wall and the second fixed wall (58.1, 58.2) being penetrated by the first opening and the second opening (84.1, 84.2) and spaced apart from a third wall and a fourth wall (58.3, 58.4) that are opposite to the first fixed wall and the second fixed wall (58.1, 58.2) and are penetrated by the third opening and the fourth opening (86.1, 86.2), wherein the first fixed wall and the second fixed wall (58.1, 58.2) of the cell (60) are connected to each other such that at least one first broken line (90) is formed in a top view, the partition tube (62) being located on both sides of the first broken line (90) and connected to the first fixed wall and the second fixed wall (58.1, 58.2), and wherein the third wall and the fourth wall (58.3, 58.4) of the cell (60) are connected to each other such that at least one second broken line (92) spaced apart from the first broken line (90) is formed in a top view.

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