Sound barrier
Patent Information
- Application Number
- JP2024051637
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-27
- Publication Date
- 2025-10-09
Smart Images
Figure 2025150642000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a sound insulating wall. [Background technology]
[0002] Structures with sound insulation capabilities are in demand in the fields of architecture, railways, etc. As an example of such capabilities, Patent Document 1 discloses a honeycomb sandwich panel with improved soundproofing properties, in which a honeycomb structure is sandwiched between plates. Patent Document 2 also discloses a sound-insulating panel that combines a fibrous layer made of a fibrous material such as glass wool or rock wool with a structure such as a honeycomb or roll core having an air layer. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-307720 [Patent Document 2] Japanese Patent Publication No. 61-83743 Summary of the Invention [Problem to be solved by the invention]
[0004] However, although the sound-insulating panel of Patent Document 1 can achieve sound-insulating performance, there is still room for improvement, particularly in the low- to mid-frequency range. Also, the sound-insulating panel of Patent Document 2 requires a process of providing a fibrous material such as glass wool or rock wool, which poses a problem of requiring a lot of manufacturing effort.
[0005] The present invention has been made in view of the above problems, and has as its object to provide a sound insulating wall that can reduce the manufacturing time and effort and has excellent sound insulating performance in the low and medium frequency ranges. [Means for solving the problem]
[0006] The first invention for solving such problems is a sound-insulating wall having a sound-insulating structure and a face material, wherein the sound-insulating structure comprises a plate material and a plurality of core materials arranged adjacent to each other, the core materials are made of a rectangular thin plate material formed into a cylindrical shape, one axial end of the core materials is joined to the plate material, adjacent core materials are able to slide against each other at their side wall portions, and the face material is arranged opposite the other axial end of the core material with an air layer between them, relative to the sound-insulating structure.
[0007] According to the sound-insulating wall of the present invention, the sound-insulating structure has adjacent core materials that are not bonded together and can slide relative to each other, so the vibration of one core material has little effect on the adjacent core material. Therefore, each core material can efficiently attenuate vibration. Furthermore, in this sound-insulating wall, the face material is arranged opposite the sound-insulating structure with an air gap between them, so the sound-insulating wall has excellent sound-insulating performance in the low-to-mid frequency range. It is also possible to omit fibrous materials such as glass wool and rock wool. If these can be omitted, the manufacturing effort can be reduced.
[0008] The second invention of the present invention for solving the above-mentioned problems is a sound-insulating wall having a pair of sound-insulating structures, the sound-insulating structures comprising a plate material and a plurality of core materials arranged adjacent to each other, the core materials being made of a rectangular thin plate material formed into a cylindrical shape, one axial end of the core materials being joined to the plate material, adjacent core materials being able to slide relative to each other at their side wall portions, and the pair of sound-insulating structures being arranged opposite each other with an air layer interposed between the other axial end portions of the core materials.
[0009] According to the sound-insulating wall of the present invention, the sound-insulating structure has adjacent core materials that are not bonded together and can slide relative to each other, so the vibration of one core material has little effect on the adjacent core material. Therefore, each core material can efficiently attenuate vibration. Furthermore, in this sound-insulating wall, a pair of sound-insulating structures are arranged opposite each other with an air gap between them, so the sound-insulating wall has excellent sound-insulating performance in the low-to-mid frequency range. It is also possible to omit fibrous materials such as glass wool and rock wool. If these can be omitted, the manufacturing effort can be reduced.
[0010] In the sound insulating wall of the present invention, the core material and the air layer are preferably enclosed by a frame material arranged around the sound insulating structure. With this configuration, the air layer is sealed off, thereby further improving the sound insulating performance.
[0011] In the sound insulating wall of the present invention, it is preferable that gaps are formed between the circumferential ends of the rectangular thin plates, and the side wall portion of the core material has slits along the axial direction. With this configuration, since the ends of the rectangular thin plates are open, the core material is more likely to vibrate, and damping efficiency is improved.
[0012] In the sound insulating wall of the present invention, the core material and the plate material are preferably joined with an epoxy adhesive, which makes it easy to fix only the bottom surface of the core material to the plate material.
[0013] Furthermore, in the sound insulating wall of the present invention, the height of the adhesive from the plate material after hardening is preferably 5% or less of the axial dimension of the core material. With this configuration, only the lower end of the core material is fixed, and the area above the lower end of the core material is more likely to vibrate, thereby increasing damping efficiency.
[0014] In the sound insulating wall of the present invention, it is preferable that the diameter of the core material be the same before and after bonding to the plate material. With this configuration, no stress is applied to the core material after bonding, making it easier for the core material to vibrate and further increasing the damping efficiency. [Effects of the Invention]
[0015] The sound insulating wall of the present invention can reduce the manufacturing effort and improve sound insulating performance in the low and medium frequency ranges. [Brief explanation of the drawings]
[0016] [Figure 1] 1 is a perspective view showing a sound-insulating structure of a sound-insulating wall according to an embodiment of the present invention. [Figure 2] 1A is a perspective view showing a rectangular thin plate material before processing, and FIG. 1B is a perspective view showing a processed core material. [Figure 3] 1 is an enlarged cross-sectional view showing a sound-insulating structure of a sound-insulating wall according to an embodiment of the present invention. [Figure 4] 1 is a partially cutaway perspective view showing a sound insulating wall according to a first embodiment of the present invention. [Figure 5] FIG. 4 is a partially cutaway perspective view showing a sound insulating wall according to a second embodiment of the present invention. [Figure 6] 10(a) to 10(d) are perspective views for explaining the shapes of samples used in the first sound insulation experiment. [Figure 7] 10 is a graph showing the results of a first sound insulation experiment. [Figure 8] 10 is a table for explaining the shapes of samples in the second sound insulation experiment. [Figure 9] 10 is a graph showing the results of Sample 1 in the second sound insulation experiment. [Figure 10] 10 is a graph showing the results of Sample 2 in the second sound insulation experiment. [Figure 11] 10 is a graph showing the results of Sample 3 in the second sound insulation experiment. [Figure 12] 10 is a graph showing the results of Sample 4 in the second sound insulation experiment. [Figure 13] 10 is a graph showing the results of Sample 5 in the second sound insulation experiment. [Figure 14] 10 is a graph showing the results of Sample 6 in the second sound insulation experiment. [Figure 15] 10 is a graph showing the results of Sample 7 in the second sound insulation experiment. [Figure 16] FIG. 10 is a perspective view showing a core material according to a modified example. DETAILED DESCRIPTION OF THE INVENTION
[0017] A sound insulating wall according to a first embodiment of the present invention will be described in detail with reference to the drawings. First, the configuration of a sound insulating wall 1 will be described. As shown in FIG. 4, the sound insulating wall 1 of this embodiment has a sound insulating structure 2 and a face material 3. As shown in FIGS. 1 to 3, the sound insulating structure 2 has a plate material 10, a core material 20, and a frame material 30.
[0018] The plate material 10 is a base member for fixing the core material 20, and has, for example, a rectangular planar shape. The plate material 10 is, for example, a metal plate made of an aluminum alloy, and has a thickness of 1 mm. Note that the material and thickness of the plate material 10 are merely examples and are determined appropriately depending on the shape and weight of the core material 20 to be attached.
[0019] As shown in FIG. 2, the core material 20 is formed by bending a rectangular thin plate material 21 into a cylindrical shape. The rectangular thin plate material 21 is made of an aluminum alloy and is configured as a thin plate with a thickness of, for example, 0.2 mm. The material and thickness of the rectangular thin plate material 21 are determined appropriately according to the required sound absorption performance, and the shape of the core material 20, such as the core diameter and core height, are also determined appropriately. Core diameters are, for example, 12 mm, 28 mm, and 50 mm, and core heights are, for example, 12 mm, 25 mm, 50 mm, 75 mm, and 100 mm. As shown in FIG. 2(b), the core material 20 is formed so that end portions 24, 24 of the rectangular thin plate material 21 overlap each other, forming a circular (V-shaped) cross section.
[0020] As shown in FIGS. 1 and 3, a plurality of core materials 20 are provided and arranged adjacent to one another on the surface of the plate material 10 (hereinafter referred to as the "sound-insulating surface 11"). The core materials 20 are arranged inside the peripheral edge of the plate material 10, leaving an installation space for the frame material 30. The side wall portions 22 of the core materials 20 abut against the side wall portions 22 of other adjacent core materials 20. The core materials 20 are fixed to the plate material 10 with, for example, an epoxy-based adhesive 12. Specifically, one axial end of the core material 20 is bonded to the sound-insulating surface 11 of the plate material 10. As shown in FIG. 3, the height from the sound-insulating surface 11 after the adhesive 12 has hardened (the height of the adhesive 12 attached to the core material 20) is 5% or less of the axial dimension of the core material 20. In other words, only one axial end of the core material 20 is adhered to the sound-insulating surface 11, and the portion near the other end (the side away from the plate material 10) excluding the one end is not adhered to the adjacent core material 20, allowing the side wall portions 22, 22 to slide against each other.
[0021] The diameter of the core material 20 is the same before and after it is bonded to the sound-insulating surface 11. In other words, the core material 20 is in a bonded state with no stress applied thereto.
[0022] The adhesive 12 is an epoxy adhesive. A highly durable two-component adhesive is suitable as an epoxy adhesive. The adhesive 12 is composed of an epoxy resin as the main agent and a modified silicone resin as the curing agent. The Shore hardness of the adhesive 12 after curing is 50 or more (62 in this embodiment).
[0023] The frame material 30 is a member that surrounds the core material 20 and the air layer 5 (described later), and is arranged along the periphery of the plate material 10. The frame material 30 is made of, for example, an extruded aluminum alloy material, and is formed in a long rod shape. The frame material 30 is arranged in a rectangular frame shape that follows the outer periphery of the plate material 10. The frame material 30 is bolted to the plate material 10. Note that the method of fixing the frame material 30 to the plate material 10 is not limited to bolting, and may be, for example, adhesive bonding. The frame material 30 is attached around the entire periphery of the plate material 10 so as to surround the multiple core materials 20 that are lined up. The thickness dimension of the frame material 30 (the dimension along the axial direction of the core material 20) is the sum of the axial dimension of the core material 20 and the thickness dimension of the air layer 5.
[0024] Next, a method for manufacturing the sound insulation structure of this embodiment will be described. The method for manufacturing the sound insulation structure includes a core material forming step, a frame material attaching step, an adhesive applying step, a core material arranging step, and a curing step.
[0025] The core material forming process is a preparatory process prior to manufacturing the sound-insulating structure, in which the core material 20 is formed in advance. In the core material forming process, as shown in FIG. 2, a rectangular thin plate 21 is processed into a cylindrical shape to form the core material 20. The rectangular thin plate 21 has a short side dimension equal to the height dimension (axial dimension) of the core material 20 and a long side dimension greater than the circumferential dimension of the core material 20 by an overlapping area between the ends. The rectangular thin plate 21 is curved so that the ends 24, 24 overlap each other and have the same curvature around the entire circumference. The core material 20 is formed to have the same shape and dimensions as after bonding. In other words, the diameter of the core material 20 is the same before and after bonding to the sound-insulating surface 11. The processing method for the core material 20 is not limited to the above-described form; it may also be formed by forming an extruded member with a C-shaped cross section and cutting it to a predetermined length.
[0026] The frame material mounting process is a process of mounting the frame material 30 on the plate material 10. The frame material 30 is mounted to the plate material 10 using fastening members such as bolts. The mounting means for the frame material 30 is not limited to fastening members, and it may also be mounted using an adhesive. The frame material mounting process may also be performed after the adhesive application process described below.
[0027] The adhesive application process is a process of applying adhesive to the surface of the plate material 10. The adhesive 12 is applied inside the frame material 30 over the entire surface of the plate material 10 on the side that will become the sound-insulating surface 11. The thickness of the applied adhesive 12 is set so that the height of the adhesive 12 adhering to the core material 20 when the core material 20 is installed does not exceed 5% of the axial dimension of the core material 20. When the core material 20 is installed, the adhesive 12 is pushed aside by the core material 20. Therefore, the applied thickness of the adhesive 12 is set smaller than the height of the adhesive adhering to the core material 10 (for example, about 0.5 mm).
[0028] The core material bonding process is a process in which multiple core materials 20 are lined up on the sound-insulating surface 11 to which adhesive 12 has been applied and bonded to the plate material 10. The core materials 20 are identical in shape, and six core materials 20 are arranged in parallel so that each core material 20 abuts at equal angular intervals. At this time, the side wall portions 22 of adjacent core materials 20 abut along the entire length in the axial direction. At the lower ends of the core materials 20, 20, adhesive 12 is applied to the inner surfaces (the surfaces opposite the abutting sides), bonding the core materials 20 to the plate material 10. The adhesive 12 is pressed by the core materials 20, 20 and rises slightly, but the height of the adhesive 12 does not exceed 10% of the axial dimension of the core material 20. The core materials 20 are arranged in parallel on the sound-insulating surface 11 of the plate material 10 in their original state without being deformed. This ensures that the diameter of the core material 20 remains the same before and after it is bonded to the sound-insulating surface 11 .
[0029] The curing step is a step of curing for a predetermined time to harden the adhesive 12. The adhesive 12 hardened through the curing step has a Shore hardness of 62.
[0030] The face material 3 is a flat plate disposed at a predetermined distance from the sound-insulating structure 2. Specifically, the face material 3 is disposed opposite the other axial end of the core material 20 with an air layer 5 interposed therebetween. The face material 3 has a rectangular planar shape, similar to the plate material 10. The face material 3 is a metal plate made of, for example, an aluminum alloy, and has a thickness of 1 mm. Note that the material and thickness of the face material 3 are merely examples and are not limited to those in this embodiment, but are determined appropriately depending on the shape and size of the face material 3. The outer peripheral edge of the face material 3 abuts against the side surface of the frame material 30 (the surface of the frame material 30 opposite to the side surface that abuts the plate material 10) and is fastened with bolts. Note that the method of fastening the face material 3 to the frame material 30 is not limited to bolting, and may be, for example, adhesive bonding.
[0031] The thickness of the air layer 5 (the distance from the tip (other axial end) of the core material 20 to the surface of the face material 3) is, for example, 5 mm. Because the air layer 5 is formed between the other axial end of the core material 20 and the face material 3, the core material 20 is not constrained and can be maintained in a state in which it is easy to vibrate. Regardless of the size of the axial dimension of the core material 20, the thickness of the air layer 5 is preferably 1 to 10 mm, and more preferably 2.5 to 7.5 mm.
[0032] When forming the sound insulating wall 1 having the above configuration, the face material 3 is brought into contact with the side surface of the frame material 30 of the sound insulating structure 2 manufactured by the above manufacturing method, and attached to the plate material 10 using fastening members such as bolts. The means for attaching the frame material 30 is not limited to fastening members, and it may also be attached using an adhesive. Here, the thickness dimension of the frame material 30 is the sum of the axial dimension of the core material 20 and the thickness dimension of the air layer 5, so by fixing the face material 3 to the side surface of the frame material 30, the air layer 5 is formed between the core material 20 and the face material 3.
[0033] Next, a sound insulating wall according to a second embodiment of the present invention will be described in detail with reference to Fig. 5. As shown in Fig. 5, a sound insulating wall 1a of this embodiment has a pair of sound insulating structures 2, 2. As in the first embodiment, the sound insulating structure 2 includes a plate material 10, a core material 20, and a frame material 30a. The pair of sound insulating structures 2, 2 are arranged so that the tip ends of the core materials 20 face each other. An air layer 5 is provided between the tip ends of the core materials 20 facing each other, and the pair of sound insulating structures 2, 2 are arranged with a gap between them. The core materials 20, 20 facing each other are arranged coaxially, with their openings facing each other.
[0034] Like the frame member 30 of the first embodiment, the frame member 30a is arranged along the periphery of the sound insulation structure 2 and is formed in the shape of a long rod made of, for example, an extruded aluminum alloy material. In the frame member 30a of the second embodiment, a thicker frame member 30a is attached to one sound insulation structure 2, and the plate member 10 of the other sound insulation structure 2 abuts and is fixed to the side of the frame member 30a (the side opposite to the side abutting the plate member 10). In other words, the frame members of a pair of sound insulation structures 2, 2 are integrated to form the frame member 30a. With the sound insulation structures 2, 2 attached, the frame member 30a spans between the plate members 10, 10 of the pair of opposing sound insulation structures 2. Both end faces of the frame member 30a are fixed in abutting contact with the surfaces of the plate members 10, 10, respectively. The thickness of the integrated frame material 30a is the sum of the axial dimension of the core material 20, the thickness of the air layer 5, and the axial dimension of the core material 20.
[0035] When forming the sound-insulating wall 1a having the above configuration, the plate material 10 to which the core material 20 is fixed is abutted against the side surface of the frame material 30a of the sound-insulating structure 2 manufactured by the above manufacturing method. Then, the plate material 10 is attached to the frame material 30a using fastening members such as bolts. The plate material 10 is attached so that the core material 20 attached to the plate material 10 is inside the frame material 30a. The means for attaching the frame material 30a and the plate material 10 is not limited to fastening members; adhesives may also be used. Here, the thickness of the frame material 30a is the sum of twice the axial dimension of the core material 20 and the thickness of the air layer 5. Therefore, by fixing the plate material 10 to the side surface of the frame material 30a, the air layer 5 is formed between the opposing core materials 20. The thickness of the air layer 5 is preferably 1 to 10 mm, more preferably 2.5 to 7.5 mm, regardless of the sum of the axial dimensions of the two opposing core materials 20.
[0036] In the above embodiment, the frame materials of the pair of sound insulation structures 2, 2 are integrated to form frame material 30a, but a frame material may be provided for each of the sound insulation structures 2, 2, and the side surfaces of the frame materials may be abutted against each other to be fixed. In this case, the thickness of the frame material is the sum of the axial dimension of core material 20 and half the thickness of air layer 5 (half the thickness of frame material 30a).
[0037] Next, with reference to FIGS. 6 and 7, a first sound insulation experiment will be described, which was conducted using the sound insulating wall 1 of the first embodiment, the sound insulating wall 1a of the second embodiment, and a comparative example of a sound insulating wall. In the sound insulation experiment, sound was incident from the sound insulating surface side of each of the sound insulating walls of the embodiments and the comparative example at multiple angles of incidence, and the sound insulation was measured for each. The experiment was conducted over a frequency range from 400 Hz to 10,000 Hz. The core material 20 used in this experiment had a core diameter of 28 mm and core heights of 22.5 mm, 25 mm, 45 mm, 50 mm, 75 mm, and 100 mm.
[0038] The first sample S1a in the first sound insulation experiment is a comparative example. As shown in FIG. 6(a), sample S1a has a two-plate structure without a core material, and uses only a single plate of the same weight as plate material 10. The single plate is made of an aluminum alloy plate and has the same rectangular shape as plate material 10. The spacing between the single plates is 50 mm. The second sample S1b is another comparative example. As shown in FIG. 6(b), sample S1b is a typical sandwich panel in which plate materials 10 are bonded to both axial sides of a round core material 20, and the core height is 50 mm.
[0039] The third sample S1c is the sound insulating wall 1 of the first embodiment. As shown in Fig. 6(c), sample S1c includes a sound insulating structure 2 and a face material 3, with the core height of the core material 20 being 45 mm and the thickness of the air layer 5 (the distance between the core material 20 and the face material 3) being 5 mm. The fourth sample S1d is the sound insulating wall 1a of the second embodiment. As shown in Fig. 6(d), sample S1d includes a pair of sound insulating structures 2, 2, with the core height of each core material 20 being 22.5 mm and the thickness of the air layer 5 (the distance between the core materials 20) being 5 mm.
[0040] As shown in Figure 7, the sound transmission loss values for each sample and the sound transmission loss values calculated using the mass law based on the average density of each sample are plotted on a graph. Note that for samples S1a, S1c, and S1d, the air layer is large enough that each component (plate or soundproofing structure) is considered to function independently, and the sound transmission loss values calculated using the mass law are added together (hereinafter referred to as the "sum of the mass law"). The sum of the mass law values is larger than the value calculated using the normal mass law.
[0041] In this experiment, it was found that the sound insulating wall 1 (sample S1c) of the first embodiment and the sound insulating wall 1a (sample S1d) of the second embodiment had larger sound transmission loss values in a specific high frequency range than the first sample S1a (two panels without a core material), and thus achieved a greater sound insulating effect. Also, it was found that the sound transmission loss values were larger in a specific frequency range (400 Hz or higher) than the second sample S1b (sandwich panel), and thus achieved a greater sound insulating effect.
[0042] The sound insulating wall 1 (sample S1c) of the first embodiment and the sound insulating wall 1a (sample S1d) of the second embodiment according to the present invention have sound insulating performance higher than the sum of the mass law in the low- to mid-frequency range (400 to 1.1 kHz). In the low- to mid-frequency range, noises such as running water sounds in toilets and bathrooms and factory noises are present, and when the sound insulating walls 1 and 1a are used as building materials, improved sound insulating performance in the low-frequency range is highly significant. The sound insulating walls 1 and 1a have sound insulating performance lower than the sum of the mass law in the high-frequency range (2 kHz or higher). Such sound insulating walls 1 and 1a are even more effective when used in situations where high-frequency sounds are not too loud. Furthermore, the frequency at which sound can be blocked can be changed by appropriately designing the shape of the core material 20 of the sound insulating structure 2.
[0043] Next, a second sound insulation experiment will be described with reference to FIGS. 8 to 15, in which the height of the core material (core thickness) was changed in the sound insulation wall 1 of the first embodiment and the sound insulation wall 1a of the second embodiment.
[0044] As shown in FIG. 8 , the first sample S2a in the second sound insulation experiment was a sound insulating wall 1a of the second embodiment with cores located on both sides, in which one core material 20 had a core thickness of 25 mm, the other core material 20 had a core thickness of 25 mm, and the air layer 5 had a thickness of 5 mm. The second sample S2b was a sound insulating wall 1 of the first embodiment with cores located on one side, in which the core material 20 had a core thickness of 50 mm, and the air layer 5 had a thickness of 5 mm. The third sample S2c was a sound insulating wall 1a of the second embodiment with cores located on both sides, in which one core material 20 had a core thickness of 25 mm, the other core material 20 had a core thickness of 50 mm, and the air layer 5 had a thickness of 5 mm. The fourth sample S2d was a sound insulating wall 1a of the second embodiment with cores located on both sides, in which the core thickness of one core material 20 was 25 mm, the other core material 20 had a core thickness of 75 mm, and the air layer 5 had a thickness of 5 mm. The fifth sample S2e is a sound insulating wall 1a of the second embodiment in which cores are located on both sides, with one core material 20 having a core thickness of 50 mm, the other core material 20 having a core thickness of 50 mm, and the air layer 5 having a thickness of 5 mm. The sixth sample S2f is a sound insulating wall 1 of the first embodiment in which cores are located on one side, with the core material 20 having a core thickness of 100 mm, and the air layer 5 having a thickness of 5 mm. The seventh sample S2g is a sound insulating wall 1a of the second embodiment in which cores are located on both sides, with the core thickness of one core material 20 being 25 mm, the other core material 20 having a core thickness of 100 mm, and the air layer 5 having a thickness of 5 mm.
[0045] The experimental results for the first to seventh samples S2a to S2g are shown in the graphs of Figures 9 to 15, respectively. As shown in Figure 9, for the first sample S2a, the sound transmission loss values of the sound insulating wall 1a (on both sides of the core) are greater than the mass law in the entire range from 400 to 10 kHz (high sound insulation performance). Furthermore, in the range below 1250 Hz, the sound transmission loss values of the sound insulating wall 1a are higher than the sum of the mass law values. For the first sample S2a, the sound transmission loss values drop in the range above 6 kHz.
[0046] As shown in Figure 10, the sound transmission loss of the second sample S2b (one side of the core) is greater than the mass law value in the entire range from 400 to 10 kHz. Furthermore, in the range below 2500 Hz, the sound transmission loss of the sound insulating wall 1 is higher than the sum of the mass law values. In the second sample S2b, the sound transmission loss value drops in the range above 5 kHz. The sound transmission loss value of the second sample S2b is generally greater than that of the first sample S2a.
[0047] As shown in Figure 11, in the third sample S2c, the sound transmission loss value of the sound insulating wall 1a (on both sides of the core) is greater than the mass law value in most regions (region below 8 kHz). Furthermore, in the region below 1250 Hz, the sound transmission loss value of the sound insulating wall 1a is higher than the sum of the mass law values. In the third sample S2c, the sound transmission loss value drops in the region above 6 kHz. The sound transmission loss value of the third sample S2c is greater than that of the first sample S2a in the region below 1600 Hz, and is smaller than that of the first sample S2a in the region above 1600 Hz.
[0048] As shown in Figure 12, in the fourth sample S2d, the sound transmission loss value of the sound insulating wall 1a (on both sides of the core) is greater than the mass law in most regions (region below 8 kHz). Furthermore, in the region below 1500 Hz, the sound transmission loss value of the sound insulating wall 1a is higher than the sum of the mass law values. In the fourth sample S2d, the sound transmission loss value drops in the region above 6 kHz. The sound transmission loss value of the fourth sample S2d is greater than that of the first sample S2a in the region below 7 kHz, and is smaller than that of the first sample S2a in the region above 7 kHz.
[0049] As shown in Figure 13, in the fifth sample S2e, the sound transmission loss value of the sound insulating wall 1a (on both sides of the core) is greater than the mass law in most regions (region below 7 kHz). Furthermore, in the region below 1500 Hz, the sound transmission loss value of the sound insulating wall 1a is higher than the sum of the mass law values. In the fifth sample S2e, the sound transmission loss value drops in the region above 6 kHz. The sound transmission loss value of the fifth sample S2e is greater than that of the first sample S2a in the region below 6 kHz, and is smaller than that of the first sample S2a in the region above 6 kHz.
[0050] As shown in FIG. 14, the sound transmission loss of the sixth sample S2f (one side of the core) is greater than the mass law in all frequencies between 400 and 10 kHz. Furthermore, the sound transmission loss of the sound insulating wall 1 is greater than the sum of the mass laws in the frequency range of 1500 Hz or less. The sound transmission loss of the sixth sample S2f drops in the frequency range of 6 kHz or more. The sound transmission loss of the sixth sample S2f is greater than that of the first sample S2a in all frequencies. Furthermore, the sound transmission loss of the sixth sample S2f is greater than that of the second sample S2b in the frequency range of 1600 Hz or less, and is smaller than that of the second sample S2b in the frequency range above 1600 Hz.
[0051] As shown in Figure 15, in the seventh sample S2g, the sound transmission loss values of the sound insulating wall 1a (on both sides of the core) are greater than the mass law in most regions (they are the same at 8 kHz). Furthermore, in the region below 2000 Hz, the sound transmission loss values of the sound insulating wall 1a are higher than the sum of the mass law values. In the seventh sample S2g, the sound transmission loss values drop in the region above 6 kHz. The sound transmission loss values of the seventh sample S2g are greater than the sound transmission loss values of the first sample S2a in the region except around 8 kHz.
[0052] Next, the samples are compared. In the low frequency range (400 to 1 kHz), the larger the core thickness (core height) of the core material 20 (the larger the aspect ratio), the higher the sound insulation performance became compared to the sum of mass law. This is thought to be because the sound insulation characteristics of the conventional single-layer lightweight sound insulation structure in which one axial end of the core material is joined to a plate material also appear in the double structure. Furthermore, as the core thickness increases, the drop in sound insulation performance becomes smaller in the high frequency range (2 kHz and above). This is thought to be a characteristic of the double structure. However, as a partial exception, when comparing cases where the core thickness is 50 mm and 75 mm, the sound insulation performance is higher in the 50 mm case.
[0053] Comparing the first sample S2a and the second sample S2b, both of which have a total sound insulation wall thickness of 57 mm, the drop in sound insulation performance in the high frequency range (2 kHz or higher) is greater for both sides of the core than for one side of the core. Comparing the fourth sample S2d, the fifth sample S2e, and the sixth sample S2f, both of which have a total sound insulation wall thickness of 107 mm, the sound insulation performance is higher for both sides of the core than for one side of the core in the low frequency range to 6 kHz. In the range of 6 Hz or higher, the sound insulation performance is higher for one side of the core than for both sides of the core.
[0054] According to the sound insulating walls 1 and 1a of the above embodiment, sound insulating performance is higher than that obtained by the sum of mass laws in the low frequency range (400 to 1 kHz). This is thought to be due to the influence of the sound insulating properties of the core material 20. Furthermore, according to the sound insulating walls 1 and 1a of the above embodiment, it is possible to reduce the drop in sound insulating properties in the mid- to high frequency range. This is thought to be because, although complex vibrations make it easy for sound to pass through a single panel, the core material 20 reduces the vibrations, thereby reducing the drop. Regarding the arrangement of the core material 20, the sound insulation performance required for a building material can be ensured whether it is on one side of the core or on both sides of the core.
[0055] Although the embodiments of the present invention have been described above, appropriate design changes are possible within the scope of the present invention. For example, in the second embodiment described above, the frame material 30a is suspended between the plate materials 10, 10 of a pair of sound-insulating structures 2, 2, but this is not limited to this. The frame material may be divided into individual sound-insulating structures 2, 2, and each may be fixed to the plate material 10 in advance. In this case, when the sound-insulating structures are integrated, the side surfaces of the frame material are abutted against each other and fixed to each other.
[0056] In the above embodiment, the adhesive 12 is an epoxy-based adhesive, but this is not limited to this. Other adhesives, such as silicone-based adhesives, may be used as long as they have a Shore hardness of at least a certain level. If the Shore hardness is 50 or more, the same effects as those of the above embodiment can be obtained.
[0057] Furthermore, in the above embodiment, the core material 20 has a circular (V-shaped) cross section in which the ends 24, 24 of the rectangular thin plate material 21 overlap, but this is not limited to this. For example, as shown in FIG. 16 , the core material 20 may be formed so that a gap is provided between the longitudinal ends 24, 24 of the rectangular thin plate material 21. That is, the side wall portion 22 of the core material 20 may be cylindrical with a slit portion 23 along the axial direction. Furthermore, the core material is not limited to a cylindrical shape, and may be elliptical or rectangular with a slit portion along the axial direction. Furthermore, the core material may be formed in a cylindrical shape with no overlapping or slit portions, with the ends of rectangular thin plates butted together. Even with other shapes such as those described above, the same effects as those of the above embodiment can be obtained. Furthermore, if the core material 20 has a shape with slit portions 23, it becomes easier for the core material 20 to vibrate.
[0058] Furthermore, in the above embodiment, the core material 20 is fixed to the plate material 10 using the adhesive 12, but this is not limited to this. It may be fixed by other joining methods such as brazing or welding. Although other joining methods such as brazing can also provide certain effects, it is preferable to use an adhesive. [Explanation of symbols]
[0059] 1. Soundproof walls 1a Sound barrier 2. Sound insulation structure 3-sided material 5 Air layer 10 Board material 11 Soundproofing surface 12 Adhesive 20 Core material 21 Rectangular thin plate material 22 Side wall 23 Slit section 24 End 30 Frame material 30a frame material
Claims
1. A sound-insulating wall having a sound-insulating structure and a surface material, The sound-insulating structure includes a plate material and a plurality of core materials arranged adjacent to each other, The core material is made of a rectangular thin plate material formed into a cylindrical shape, One axial end of the core material is joined to the plate material, The adjacent core materials are slidable relative to each other at their side wall portions, The face material is disposed opposite the sound-insulating structure at the other axial end of the core material with an air gap therebetween. A sound insulation wall characterized by:
2. A sound insulating wall having a pair of sound insulating structures, The sound-insulating structure includes a plate material and a plurality of core materials arranged adjacent to each other, The core material is made of a rectangular thin plate material formed into a cylindrical shape, One axial end of the core material is joined to the plate material, The adjacent core materials are slidable relative to each other at their side wall portions, The pair of sound-insulating structures are disposed opposite each other between the other axial ends of the core material with an air layer interposed therebetween. A sound insulation wall characterized by:
3. The core material and the air layer are surrounded by a frame material arranged around the sound-insulating structure.
3. The sound insulating wall according to claim 1 or 2.
4. A gap is formed between the circumferential ends of the rectangular thin plate material, The side wall of the core material has a slit along the axial direction.
3. The sound insulating wall according to claim 1 or 2.
5. The core material and the plate material are bonded together with an epoxy adhesive.
3. The sound insulating wall according to claim 1 or 2.
6. The height of the adhesive from the plate material after hardening is 5% or less of the axial dimension of the core material.
6. The sound insulating wall according to claim 5.
7. The diameter of the core material is the same before and after bonding to the plate material.
6. The sound insulating wall according to claim 5.