JP7684098B2 - Sound absorbing panels and soundproof walls - Google Patents

Description

The present invention relates to sound-absorbing panels and soundproof walls.

Conventionally, the technologies disclosed in Patent Documents 1 to 3 have been proposed as technologies related to sound-absorbing panels.

The soundproof wall disclosed in Patent Document 1 is composed of an FRP soundproof panel and a mounting part with a depth of 2 to 20% of the height of the soundproof panel and a through hole for fixing so that the panel can be attached to the building frame. A sound-absorbing panel is installed on the noise source side of the FRP soundproof wall, and a reinforcing stiffener is attached to the side of the sound-absorbing panel.

The soundproofing panels disclosed in Patent Document 2 are installed between pillars that are set at regular intervals, and fall prevention fittings are attached to each soundproofing panel by bolts (at least one per soundproofing panel). Fall prevention wire ropes are threaded through each wire rope hole in order to weave around each fall prevention fitting, which are arranged in a connected arrangement in the vertical and horizontal directions.

The soundproofing panel disclosed in Patent Document 3 is a soundproofing panel that is attached to a wall surface erected at the edge of a vehicle roadway, and is equipped with upper and lower engaging parts with a grooved cross section that are attached to the vehicle road side of the wall surface and extend laterally along the wall surface, and a sound absorbing body that has a panel case that contains sound absorbing material and has many small holes formed on the front side, and has an upper end that fits into the upper engaging part and a lower end that fits into the lower engaging part.

JP 2011-58252 A JP 2009-108634 A JP 2013-204345 A

However, in the technology disclosed in Patent Document 1, the reinforcing stiffener is provided on the side of the sound-absorbing material. Because this reinforcing stiffener does not have a sound-absorbing surface, there is a risk of multiple reflected sound occurring between the reinforcing stiffener extending in the vertical direction and a vehicle such as a train. This results in a problem of low sound absorption efficiency.

The technology disclosed in Patent Document 2 is not a type that has an integrated support, but rather fixes adjacent panels via the support. For this reason, it is necessary to adjust the support spacing according to the panel dimensions, and then erect the support. This poses the problem of low workability as a soundproof wall.

The technology disclosed in Patent Document 3 is not one that is integrated with the supports, but rather one in which the soundproofing panels are attached to the surface of a wall made of cast-in-place concrete. This means that it is necessary to construct a concrete wall surface for mounting the soundproofing panels. This poses the problem of low ease of construction as a soundproof wall.

The present invention was devised in consideration of the above-mentioned problems, and its purpose is to provide a sound-absorbing panel and soundproof wall that can improve workability and sound-absorbing efficiency.

The sound-absorbing panel according to the present invention is a pillar-integrated sound-absorbing panel, comprising a sound-absorbing material, a casing in which the sound-absorbing material is housed, and a pillar member, the casing having a front plate disposed on the sound source side and having a plurality of punched holes formed therein, a rear plate disposed on the sound-receiving side of the front plate, and a pair of side plates connecting the front plate and the rear plate, the pillar member having a pair of pillar flanges opposed to the rear plate and spaced apart from each other, a pair of pillar webs extending from the pair of pillar flanges toward the sound-receiving side, and a pillar plate portion connecting the pair of pillar webs, the casing having a fixing portion provided on the pillar flanges. the pair of column webs are fixed to the support member by material, the pair of column webs are flush with a pair of first reference surfaces which are flush with the outer surfaces of the pair of side panels, or are arranged in a region between the pair of first reference surfaces , the rear panel has a first rear panel formed along the front panel, a second rear panel formed along the front panel and arranged on the sound receiving side of the first rear panel, and a third rear panel connecting the first rear panel and the second rear panel, and inside the casing, a first region on the sound source side of the first rear panel and a second region on the sound receiving side of the first rear panel are formed, and the sound absorbing material is contained in the first region and the second region .

The sound-absorbing panel of the present invention is characterized in that multiple sound-absorbing panels of the present invention are arranged side by side with no gaps.

The present invention makes it possible to improve workability and sound absorption efficiency.

FIG. 1 is a perspective view showing a soundproof wall using a sound-absorbing panel according to the first embodiment. FIG. 2 is an exploded perspective view showing the sound-absorbing panel according to the first embodiment. Figure 3 is a cross-sectional view of the sound-absorbing panel of the first embodiment cut in a plane perpendicular to the parallel installation direction, where Figure 3(a) is a cross-sectional view cut in a plane passing through the column flange, and Figure 3(b) is a cross-sectional view cut in a plane passing through the second sound-absorbing material. 4(a) is a cross-sectional view taken along line 3A-3A in FIG. 3(a), and FIG. 4(b) is a cross-sectional view taken along line 3B-3B in FIG. 3(a). FIG. 5 is a cross-sectional view of a soundproof wall using the sound-absorbing panel according to the first embodiment, taken along a plane perpendicular to the up-down direction. Figure 6 is a cross-sectional view of a sound-absorbing panel according to a second embodiment taken along a plane perpendicular to the vertical direction, where Figure 6(a) is a cross-sectional view taken along a plane passing through the first sound-absorbing material, and Figure 6(b) is a cross-sectional view taken along a plane passing through the reinforcing member. Figure 7 is a cross-sectional view of a sound-absorbing panel in accordance with a third embodiment taken along a plane perpendicular to the vertical direction, where Figure 7(a) is a cross-sectional view taken along a plane passing through the first sound-absorbing material, and Figure 7(b) is a cross-sectional view taken along a plane passing through the reinforcing member. Figure 8 is a cross-sectional view of a sound-absorbing panel in accordance with a fourth embodiment, taken along a plane perpendicular to the vertical direction, where Figure 8(a) is a cross-sectional view taken along a plane passing through the first sound-absorbing material, and Figure 8(b) is a cross-sectional view taken along a plane passing through the reinforcing member. Figure 9 is a cross-sectional view of a sound-absorbing panel in accordance with a fifth embodiment taken along a plane perpendicular to the vertical direction, where Figure 9(a) is a cross-sectional view taken along a plane passing through the first sound-absorbing material, and Figure 9(b) is a cross-sectional view taken along a plane passing through the reinforcing member. FIG. 10 is a cross-sectional view of the sound-absorbing panel according to the sixth embodiment, taken along a plane perpendicular to the up-down direction. FIG. 11 is a diagram showing the results of a normal incidence sound absorption test carried out in Example 1. FIG. 12 is a diagram showing the results of a reverberation chamber test carried out in Example 2. FIG. 13 is a diagram showing the results of a reverberation chamber test carried out in Example 3.

Below, we will explain in detail how to implement the sound-absorbing panel and soundproof wall to which the present invention is applied, with reference to the drawings.

First Embodiment
FIG. 1 is a perspective view showing a soundproof wall using a sound-absorbing panel according to the first embodiment. FIG. 2 is an exploded perspective view showing a sound-absorbing panel according to the first embodiment. FIG. 3 is a cross-sectional view of the sound-absorbing panel according to the first embodiment cut along a plane perpendicular to the juxtaposition direction, FIG. 3(a) is a cross-sectional view cut along a plane passing through the column flange, and FIG. 3(b) is a cross-sectional view cut along a plane passing through the second sound-absorbing material. FIG. 4(a) is a CC cross-sectional view of FIG. 3(a), and FIG. 4(b) is a CC cross-sectional view of FIG. 3(a). Note that punching holes are omitted from FIG. 2.

The soundproof wall 100 is erected on the edge of a vehicle path such as a railway or road. The soundproof wall 100 is provided with multiple sound-absorbing panels 1 lined up without any gaps. The multiple sound-absorbing panels 1 are connected to each other by connecting materials 9. The direction in which the sound-absorbing panels 1 are lined up is the juxtaposition direction X, the direction perpendicular to the juxtaposition direction X is the depth direction Y, and the direction perpendicular to the juxtaposition direction X and the depth direction is the up-down direction Z.

The sound-absorbing panel 1 is a sound-absorbing panel with an integrated support. The sound-absorbing panel 1 comprises a sound-absorbing material 2, a casing 3, and a support member 4.

The sound-absorbing material 2 is made of fibers such as glass wool and polyester, and has a certain sound-absorbing function.

The casing 3 houses the sound-absorbing material 2. The casing 3 has a front panel 31, a back panel 33, a pair of side panels 32, and a top panel 39.

The front plate 31 is a rectangular steel plate that is placed on the sound source side. The front plate 31 has multiple punched holes that allow the sound absorbing material 2 to absorb noise from the road on the ground, and serves as a sound absorbing surface that absorbs sounds generated by vehicles, etc.

The side plate 32 is a rectangular steel plate that connects the front plate 31 and the back plate 33.

The rear panel 33 is a steel plate that is positioned closer to the sound receiving side than the front panel 31. The rear panel 33 has a first rear panel 33a that is formed along the front panel 31, a second rear panel 33b that is formed along the front panel 31 and is positioned closer to the sound receiving side than the first rear panel 33a, and a third rear panel 33c that connects the first rear panel 33a and the second rear panel 33b.

The first rear panel 33a is formed along the front panel 31 from each of the pair of side panels 32. The third rear panel 33c is formed from each of the pair of first rear panels 33a toward the sound receiving side. The second rear panel 33b connects the pair of third rear panels 33c. The first rear panel 33a is provided with a fixing member 36 consisting of a bolt 37 and a nut 38. The fixing member 36 penetrates the first rear panel 33a and the column flange 41.

Inside the casing 3, a first area A1 is formed on the sound source side of the first back panel 33a, and a second area A2 is formed on the sound receiving side of the first back panel 33a. The first area A1 and the second area A2 house the sound absorbing material 2. The first area A1 houses the first sound absorbing material 21, and the second area A2 houses the second sound absorbing material 22. For example, the first sound absorbing material 21 and the second sound absorbing material 22 are preferably made of different materials, and the unit volume weight of the first sound absorbing material 21 is preferably smaller than the unit volume weight of the second sound absorbing material 22. The first sound absorbing material 21 and the second sound absorbing material 22 may be made of the same material and have the same unit volume weight.

A reinforcing member 35 is provided inside the casing 3, which is in contact with the front plate 31 and the back plate 33. The reinforcing member 35 has an upper reinforcing plate 35a arranged above the fixing member 36, a lower reinforcing plate 35b arranged below the fixing member 36, and a connecting reinforcing plate 35c connecting the upper reinforcing plate 35a and the lower reinforcing plate 35b. The reinforcing member 35 is formed with a U-shaped cross section, and for example, a C-shaped steel is used. The reinforcing member 35 may also be an H-shaped steel formed with an H-shaped cross section.

The top plate 39 is provided at the upper end to cover the front plate 31, the back plate 33, and the pair of side plates 32.

The support member 4 secures the casing 3 from the sound receiving side. A base plate 49 is attached to the lower end of the support member 4. The height of the support member 4 is greater than the height of the casing 3.

The support member 4 has a pair of column flanges 41 that face the back panel 33 and are spaced apart from each other, a pair of column webs 42 that extend from the pair of column flanges 41 toward the sound receiving side, and a column plate portion 43 that connects the pair of column webs 42.

A fixing member 36 consisting of a bolt 37 and a nut 38 is provided on the column flange 41. The casing 3 is fixed to the column member 4 by the fixing member 36.

The outer surfaces of the pair of column webs 42 are arranged flush with a pair of first reference surfaces L that are flush with the outer surfaces of the pair of side panels 32. The column webs 42 may be arranged in the area between the pair of first reference surfaces L.

The connecting member 9 connects the column flange 41 arranged above the casing 3 of one sound-absorbing panel 1 to the column flange 41 arranged above the casing 3 of the other sound-absorbing panel 1. The connecting member 9 is made of an angle bar or the like that has an L-shaped cross section. The connecting member 9 is fixed to the column flange 41 by a fixing member 91 such as a bolt or nut.

According to this embodiment, the sound absorbing material 2, the casing 3 in which the sound absorbing material 2 is housed, and the support member 4 to which the casing 3 is fixed from the sound receiving side are provided. The casing 3 has a front panel 31 arranged on the sound source side, a back panel 33 arranged on the sound receiving side of the front panel 31, and a pair of side panels 32 connecting the front panel 31 and the back panel. The support member 4 has a pair of column flanges 41 facing the back panel 33 and arranged at a distance from each other, a pair of column webs 42 each extending from the pair of column flanges 41 toward the sound receiving side, and a column plate portion 43 connecting the pair of column webs 42. The casing 3 is fixed to the support member 4 by a fixing member 36 provided on the column flange 41, and the pair of column webs 42 are arranged flush with a pair of first reference surfaces L that are flush with the outer surfaces of the pair of side panels 32, or in the area between the pair of first reference surfaces L.

As a result, as shown in FIG. 5, the sound source side is covered by the front plate 31 which serves as the sound absorbing surface, and the support member 4 is not exposed from the side of the front plate 31. Therefore, sound S1 generated when a vehicle such as a train runs can be made to enter the inside of the casing 3 from near the end of the front plate 31 in the parallel installation direction X, and can be absorbed by the sound absorbing material 2. As a result, it is possible to suppress multiple reflected sound generated between the vehicle and a member that does not have a sound absorbing function, such as a conventional reinforcing stiffener, and to improve sound absorption efficiency.

In addition, according to this embodiment, since the sound-absorbing panel 1 is an integrated type with the support posts, there is no need to adjust the support post spacing to match the dimensions of the panel and attach the panel to the support posts. This makes it possible to improve workability.

According to this embodiment, the rear panel has a first rear panel 33a formed along the front panel 31, a second rear panel 33b formed along the front panel 31 and positioned closer to the sound receiving side than the first rear panel 33a, and a third rear panel 33c connecting the first rear panel 33a and the second rear panel 33b. Inside the casing 3, a first area A1 is formed closer to the sound source than the first rear panel 33a, and a second area A2 is formed closer to the sound receiving side than the first rear panel 33a. The sound absorbing material 2 is housed in the first area A1 and the second area A2.

As a result, as shown in FIG. 5, when sound S2 generated when a train or other vehicle is traveling enters the inside of the casing 3 from the front panel 31, the sound can be absorbed by the sound-absorbing material 2 housed in the first area A1 and the second area A2. As a result, the thickness of the sound-absorbing material 2 in the depth direction Y can be secured more than if the sound-absorbing material 2 were housed only in the first area A1, and the sound absorption efficiency can be improved.

According to this embodiment, the first back panel 33a is formed along the front panel 31 from each of the pair of side panels 32, the third back panel 33c is formed from each of the pair of first back panels 33a toward the sound receiving side, and the second back panel 33b connects the pair of third back panels 33c. This allows the second sound absorbing material 22 to be stored in the second area A2 formed in one location inside the casing 3. This makes it easy to store the second sound absorbing material 22.

According to this embodiment, the sound absorbing material 2 has a first sound absorbing material 21 housed in the first area A1 and a second sound absorbing material 22 housed in the second area A2, and the unit volume weight of the second sound absorbing material 22 is greater than the unit volume weight of the first sound absorbing material 21. This makes it possible to improve the sound absorption efficiency in the frequency band of about 800 Hz to 4000 Hz. For this reason, it is more suitable for use as a sound absorbing panel for railways.

According to this embodiment, the fixing member 36 penetrates the back plate 33 and the column flange 41, and a reinforcing member 35 that contacts the front plate 31 and the back plate 33 is provided inside the casing 3. This makes it possible to improve the rigidity of the casing 3.

According to this embodiment, the reinforcing member 35 is provided to cover the first sound-absorbing material 21. This makes it possible to prevent the sound-absorbing material 2 from getting wet due to rainwater or the like that has entered the inside of the casing 3. This makes it possible to prevent a decrease in the sound-absorbing function of the sound-absorbing material 2.

According to this embodiment, the fixing member 36 penetrates the first back panel 33a and the column flange 41, and the head of the bolt 37 is placed on the back panel 33. As a result, the head of the bolt 37 is not exposed to the front panel 31. This makes it possible to suppress the building limit on the vehicle body side. In addition, when the sound-absorbing material 2 deteriorates over time, the casing 3 containing the sound-absorbing material 2 can be removed on-site by removing the bolt 37, and by following the reverse procedure, it is possible to replace the casing 3 containing the sound-absorbing material 2 with a new one while holding the support member 4. This makes it possible to easily replace the sound-absorbing material 2. In addition, since the support member 4, which serves as the wall surface, is present during the replacement work of the casing 3 containing the sound-absorbing material 2, there is no risk of the worker falling, and the replacement work can be performed safely.

According to this embodiment, multiple sound-absorbing panels 1 are arranged side by side with no gaps. As a result, the sound source side is covered by the front plate 31, which is the sound-absorbing surface, and the support member 4 is not exposed from the side of the front plate 31. Therefore, sound S1 generated when a vehicle such as a train runs can be made to enter the inside of the casing 3 from near the end of the front plate 31 in the parallel arrangement direction X, and can be absorbed by the sound-absorbing material 2. As a result, it is possible to suppress multiple reflected sound generated between the vehicle and a member that does not have a sound-absorbing function, such as a conventional reinforcing stiffener, and to improve sound absorption efficiency.

According to this embodiment, the height of the support member 4 is greater than the height of the casing 3, and a connecting member 9 is further provided to connect the column flange 41 arranged above the casing 3 of one sound-absorbing panel 1 to the column flange 41 arranged above the casing 3 of the other sound-absorbing panel 1. This allows adjacent sound-absorbing panels 1 to be connected to each other, making it possible to adjust the passage of the sound-absorbing panels 1.

Second Embodiment
In the sound-absorbing panel 1 according to the second embodiment, as shown in Fig. 6, fixing members 36 are provided in two locations, and reinforcing members 35 are provided on the upper side of each fixing member 36. The reinforcing members 35 are provided on the upper side of the first sound-absorbing material 21. Therefore, the reinforcing members 35 do not cover the entire upper side of the first sound-absorbing material 21. Note that Fig. 6(a) shows a portion corresponding to the 3A-3A cross section in Fig. 3(a), and Fig. 6(b) shows a portion corresponding to the 3B-3B cross section in Fig. 3(a).

According to this embodiment, the fixing member 36 penetrates the back plate 33 and the column flange 41, and a reinforcing member 35 that contacts the front plate 31 and the back plate 33 is provided inside the casing 3. This makes it possible to improve the rigidity of the casing 3.

Third Embodiment
In the sound-absorbing panel 1 according to the third embodiment, as shown in Fig. 7, the fixing member 36 penetrates the front plate 31, the first rear plate 33a, and the column flange 41. The head of the bolt 37 is exposed in the front plate 31. Fig. 7(a) shows a portion corresponding to the 3A-3A cross section in Fig. 3(a), and Fig. 7(b) shows a portion corresponding to the 3B-3B cross section in Fig. 3(a).

Even in this case, the sound source side is covered by the front plate 31, which serves as the sound absorbing surface, and the support member 4 is not exposed from the side of the front plate 31. Therefore, sound S1 generated when a vehicle such as a train runs can be made to enter the inside of the casing 3 from near the end of the front plate 31 in the parallel installation direction X, and can be absorbed by the sound absorbing material 2. As a result, it is possible to suppress multiple reflected sounds that occur between the vehicle and a member that does not have a sound absorbing function, such as a conventional reinforcing stiffener, and to improve sound absorption efficiency.

Fourth Embodiment
In the sound-absorbing panel 1 according to the fourth embodiment, as shown in Fig. 8, the second back plate 33b is formed from the pair of side plates 32 along the front plate 31, the third back plate 33c is formed from the pair of second back plates 33b toward the sound source side, and the first back plate 33a connects the pair of third back plates 33c. Note that Fig. 8(a) shows a portion corresponding to the 3A-3A cross section in Fig. 3(a), and Fig. 8(b) shows a portion corresponding to the 3B-3B cross section in Fig. 3(a).

The column flange 41 has a first column flange 41a facing the first back plate 33a, a second column flange 41b facing the second back plate 33b, and a first column flange 41c facing the third back plate 33c. A fixing member 36 is provided on the first column flange 41a.

According to this embodiment, the second back plate 33b is formed along the front plate 31 from each of the pair of side plates 32, the third back plate 33c is formed from each of the pair of second back plates 33b toward the sound source side, and the first back plate 33a connects the pair of third back plates 33c. This allows the second sound-absorbing material 22 to be housed in the second area A2 formed in two places inside the casing 3. This makes it possible to improve the sound absorption efficiency.

Fifth Embodiment
In the sound-absorbing panel 1 according to the fifth embodiment, as shown in Fig. 9, the back plate 33 is a flat plate extending along the front plate 31. As a result, only the first area A1 is formed inside the casing 3. Note that Fig. 9(a) shows a portion corresponding to the 3A-3A cross section in Fig. 3(a), and Fig. 9(b) shows a portion corresponding to the 3B-3B cross section in Fig. 3(a).

Even in this case, the sound source side is covered by the front plate 31, which serves as the sound absorbing surface, and the support member 4 is not exposed from the side of the front plate 31. Therefore, sound S1 generated when a vehicle such as a train runs can be made to enter the inside of the casing 3 from near the end of the front plate 31 in the parallel installation direction X, and can be absorbed by the sound absorbing material 2. As a result, it is possible to suppress multiple reflected sounds that occur between the vehicle and a member that does not have a sound absorbing function, such as a conventional reinforcing stiffener, and to improve sound absorption efficiency.

Sixth Embodiment
10 , in the sound-absorbing panel 1 according to the sixth embodiment, the second region A2 contains a second sound-absorbing material 22 and a third sound-absorbing material 23 as the sound-absorbing material 2. Therefore, the sound-absorbing material 2 contained in the second region A2 is configured in a laminated structure of the second sound-absorbing material 22 and the third sound-absorbing material 23. The unit volume weight of the third sound-absorbing material 23 is greater than the unit volume weight of the first sound-absorbing material 21 and is greater than the unit volume weight of the second sound-absorbing material 22.

As shown in FIG. 10, in the sound-absorbing panel 1, the third sound-absorbing material 23 is provided on the opposite side of the second sound-absorbing material 22 from the first sound-absorbing material 21. It is preferable that the unit volume weight of the second sound-absorbing material 22 is greater than the unit volume weight of the first sound-absorbing material 21, but it may be smaller than the unit volume weight of the first sound-absorbing material 21.

According to this embodiment, the sound absorbing material 2 has a first sound absorbing material 21 housed in the first area A1, a second sound absorbing material 22 housed in the second area A2, and a third sound absorbing material 23 housed in the second area A2 and provided on the opposite side of the first sound absorbing material 21 with the second sound absorbing material 22 in between, and the unit volume weight of the third sound absorbing material 23 is greater than the unit volume weight of the first sound absorbing material 21 and greater than the unit volume weight of the second sound absorbing material 22. As a result, the third sound absorbing material 23, which has the greatest unit volume weight, is housed on the sound receiving side inside the casing 3. This makes it possible to obtain a high sound absorption rate over a wide frequency band.

Test specimens for Cases 1 to 3 were prepared, and measurements of normal incidence sound absorption coefficients were carried out using an acoustic tube. Test specimens for Cases 1 to 3 were prepared with different sound absorbing material thicknesses and unit volume weights. In Case 1, a polyester fiber sound absorbing material with a unit volume weight of 24 kg/ ^m3 and a thickness of 50 mm was used as the sound absorbing material. In Case 2, a polyester fiber sound absorbing material with a unit volume weight of 24 kg/ ^m3 and a thickness of 70 mm was used as the sound absorbing material. In Case 3, a polyester fiber sound absorbing material with a unit volume weight of 24 kg/ ^m3 and a thickness of 50 mm and a polyester fiber sound absorbing material with a unit volume weight of 80 kg/ ^m3 and a thickness of 20 mm were used as the sound absorbing material. The overall thickness of the sound absorbing material in Case 3 was 70 mm, the same as that in Case 2. In Case 3, a sound absorbing material with a unit weight of 24 kg/ ^m3 was placed on the sound incident side, and a sound absorbing material with a unit weight of 80 kg/ ^m3 was placed adjacent to this.

Figure 11 shows the measurement results of normal incidence sound absorption coefficient in Example 1. In Figure 11, the vertical axis represents normal incidence sound absorption coefficient, and the horizontal axis represents 1/3 octave band center frequency (Hz).

As shown in Figure 11, in Cases 2 and 3, the normal incidence sound absorption coefficient on the low frequency side of about 400 to 1000 Hz was improved compared to Case 1. This means that by increasing the thickness of the sound absorbing material, it is possible to improve the sound absorption efficiency in the low frequency band of about 400 to 1000 Hz.

In addition, in case 3, the normal incidence sound absorption coefficient on the high frequency side of about 1000 Hz to 4000 Hz was improved compared to case 2. As a result, even if the thickness of the sound absorbing material is the same, by placing a sound absorbing material with a small unit weight on the sound incident side and placing a sound absorbing material with a larger unit weight adjacent to it, it is possible to improve the sound absorption efficiency in the high frequency band of about 1000 Hz to 4000 Hz.

Here, the frequency band of 400 Hz to 1000 Hz is dominant on roads, and the frequency band of 800 Hz to 4000 Hz is dominant on railways. Therefore, in sound-absorbing panels for roads, it is effective to suppress the frequency band of 400 Hz to 1000 Hz, and in railways, it is effective to suppress the frequency band of 800 Hz to 4000 Hz. In this regard, in case 3, it is possible to improve the sound absorption efficiency in the high frequency band of 800 Hz to 4000 Hz, and therefore it is suitable for use as a sound-absorbing panel for railways.

Test specimens for Cases 4 to 6 were prepared, and the reverberation room sound absorption coefficient was measured based on "JIS A 1409 Measurement method for reverberation room sound absorption coefficient". The test specimens used were laminated with a polyester fiber sound absorbing material with a unit weight of 24 kg/ ^m3 and a thickness of 50 mm, and a polyester fiber sound absorbing material with a unit weight of 80 kg/ ^m3 and a thickness of 20 mm. In Case 4, a steel plate was provided so that 33% of the area of the sound absorbing material was covered. In Case 5, a steel plate was provided so that 17% of the area of the sound absorbing material was covered. In Case 6, no steel plate was provided, and the entire sound absorbing material was used. The steel plate covering the sound absorbing material reflects sound and simulates a columnar surface. That is, in cases 4 and 5, a sound-absorbing panel is assumed in which the cylindrical surface that does not have sound-absorbing function is exposed on the sound source side, while in case 6, a sound-absorbing panel is assumed in which there is no cylindrical surface on the sound source side, and the entire sound source side of the sound-absorbing panel is the sound-absorbing surface.

Figure 12 shows the results of measuring the reverberation room sound absorption coefficient in Example 2. In Figure 11, the vertical axis shows the reverberation room sound absorption coefficient, and the horizontal axis shows the 1/3 octave band center frequency (Hz). Figure 12 shows the results for Cases 4 to 6.

As shown in Figure 12, the reverberation room sound absorption coefficient of Case 6 is improved over those of Cases 4 and 5. From the above results, it can be considered that although the sound absorption efficiency is low due to the cylindrical surface being exposed to the sound source side, the sound absorption efficiency can be improved as the area of the cylindrical surface is reduced.

Based on Example 2, test specimens of Comparative Example 1, Inventive Example 1, and Inventive Example 2 were prepared, and reverberation chamber tests were carried out based on "JIS A 1409 Method for Measuring Sound Absorption Coefficient in a Reverberation Chamber". The test specimens were made by laminating a polyester fiber sound absorbing material having a unit weight of 24 kg/ ^m3 and a thickness of 50 mm and a polyester fiber sound absorbing material having a unit weight of 80 kg/ ^m3 and a thickness of 20 mm as sound absorbing materials. Comparative Example 1 is similar to Case 4 of Example 2 described above. In Inventive Examples 1 and 2, sound absorbing materials were separately installed so as to cover the steel plate installed in Case 4. That is, Comparative Example 1 assumes a sound absorbing panel with exposed columnar surfaces that do not have a sound absorbing function, and Inventive Examples 1 and 2 assume a sound absorbing panel with no columnar surfaces and in which the entire sound source side of the sound absorbing panel is the sound absorbing surface. The sound absorbing material replaced in Inventive Example 1 is a polyester fiber sound absorbing material having a unit weight of 24 kg/ ^m3 and a thickness of 20 mm. The sound absorbing material substituted in Example 2 of the present invention is a polyester fiber sound absorbing material having a unit weight of 24 kg/ ^m3 and a thickness of 50 mm.

Figure 13 shows the results of measuring the reverberation room sound absorption coefficient in Example 3. In Figure 13, the vertical axis represents the reverberation room sound absorption coefficient, and the horizontal axis represents the 1/3 octave band center frequency (Hz). Figure 13 shows the results of Comparative Example 1 and Invention Examples 1 and 2.

As shown in Figure 13, the reverberation room sound absorption coefficient of invention examples 1 and 2 was improved over that of comparison example 1. From the above results, it is possible to improve sound absorption efficiency in a sound absorbing panel in which there is no columnar surface on the sound source side and the entire sound source side of the sound absorbing panel is the sound absorbing surface. In particular, invention examples 1 and 2 are suitable for use as sound absorbing panels for railways because they can improve sound absorption efficiency in the high frequency band of 800 Hz to 4000 Hz.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in appropriate combinations. Furthermore, this invention can be implemented in various new forms in addition to the above-mentioned several embodiments. Therefore, each of the above-mentioned several embodiments can be variously omitted, replaced, or modified without departing from the gist of this invention. Such new forms and modifications are included in the scope and gist of this invention, as well as in the invention described in the claims and the scope of equivalents of the invention described in the claims.

100: Soundproof wall 1: Sound absorbing panel 2: Sound absorbing material 21: First sound absorbing material 22: Second sound absorbing material 23: Third sound absorbing material 3: Casing A1: First area A2: Second area 31: Front panel 32: Side panel 33: Rear panel 33a: First rear panel 33b: Second rear panel 33c: Third rear panel 35: Reinforcement member 35a: Upper reinforcing plate 35b: Lower reinforcing plate 35c: Joint reinforcing plate 36: Fixing member 37: Bolt 38: Nut 39: Top panel 4: Support member 41: Column flange 41a: First column flange 41b: Second column flange 41c: First column flange 42: Column web 43: Column plate portion 49 : Base plate 9 : Connecting member 91 : Fixing member L : First reference plane X : Parallel arrangement direction Y : Depth direction

Claims (9)

A sound-absorbing panel with an integrated support,
Sound absorbing material;
A casing in which the sound absorbing material is housed;
A support member,
The casing comprises:
a front plate disposed on the sound source side and having a plurality of punched holes;
A back panel disposed on the sound receiving side relative to the front panel;
A pair of side plates connecting the front plate and the rear plate,
The support member is
A pair of column flanges arranged opposite the back panel and spaced apart from each other;
A pair of column webs extending from the pair of column flanges toward the sound receiving side,
A column plate portion connecting the pair of column webs,
The casing is fixed to the support member by a fixing member provided on the column flange,
The pair of column webs are disposed flush with a pair of first reference surfaces that are flush with the outer surfaces of the pair of side panels, or in an area between the pair of first reference surfaces ;
The back panel is
a first rear plate formed along the front plate;
a second rear panel formed along the front panel and disposed on a sound receiving side relative to the first rear panel;
a third rear plate connecting the first rear plate and the second rear plate,
A first area is formed inside the casing, the first area being closer to a sound source than the first back panel, and a second area is formed inside the casing, the first area being closer to a sound receiving side than the first back panel,
The sound absorbing material is accommodated in the first area and the second area.
A sound-absorbing panel that features: The first rear plate is formed along the front plate from each of the pair of side plates,
the third rear plate is formed from each of the pair of first rear plates toward the sound receiving side,
The sound-absorbing panel according to claim 1 , wherein the second back plate connects a pair of the third back plates. The second rear plate is formed along the front plate from each of the pair of side plates,
the third rear plate is formed from the pair of second rear plates toward a sound source side,
The sound-absorbing panel according to claim 1 , wherein the first back plate connects a pair of the third back plates. The sound absorbing material includes a first sound absorbing material accommodated in the first region and a second sound absorbing material accommodated in the second region,
4. The sound absorbing panel according to claim 1 , wherein the unit volume weight of the second sound absorbing material is greater than the unit volume weight of the first sound absorbing material. the sound-absorbing material includes a first sound-absorbing material accommodated in the first region, a second sound-absorbing material accommodated in the second region, and a third sound-absorbing material accommodated in the second region and provided on the opposite side of the first sound-absorbing material with the second sound-absorbing material in between,
The sound-absorbing panel according to any one of claims 1 to 3 , wherein the unit volume weight of the third sound-absorbing material is greater than the unit volume weight of the first sound-absorbing material and greater than the unit volume weight of the second sound-absorbing material. The fixing member penetrates the back plate and the column flange,
The sound-absorbing panel according to any one of claims 1 to 5 , wherein a reinforcing member is provided inside the casing and is in contact with the front panel and the back panel. The fixing member penetrates the back plate and the column flange,
a reinforcing member in contact with the front plate and the rear plate is provided inside the casing;
The reinforcing member is
An upper reinforcing plate is disposed on the upper side of the fixing member,
The sound-absorbing panel according to any one of claims 1 to 6 , wherein the reinforcing member is disposed so as to cover an upper side of the sound-absorbing material. A soundproof wall comprising a plurality of sound-absorbing panels according to any one of claims 1 to 7 arranged side by side without any gaps. The height of the support member is greater than the height of the casing,
9. The soundproof wall according to claim 8, further comprising a connecting member that connects the column flange that is disposed above the sound-absorbing panel of the support member of one of the sound-absorbing panels to the column flange that is disposed above the sound-absorbing panel of the support member of the other of the sound-absorbing panels.

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