JP2020101579A - Soundproof structure and soundproof panel - Google Patents

Abstract

To provide a soundproof structure and a soundproof panel, which achieve both structural rigidity and soundproof performance, which are applied by fastening a porous body to perforated plates.SOLUTION: A soundproof structure 10 and a soundproof panel comprise: core bodies 12 constituting a plurality of cells 14; a back plate 18 for covering opening faces of the respective cells in a thickness direction of the core bodies; perforated plates 20 which are arranged on an opposite side of the back plate via the core bodies in the thickness direction and in which through holes are formed; a porous body 24 which is brought into contact with the perforated plates in the thickness direction; and a fastening part 28 for fastening the porous body to a member except for the porous body. A ratio of an area in a range where the porous body is fastened to the perforated plates by the fastening part with respect to a contact area with the perforated plates in the porous body is 92% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a soundproof structure and a soundproof panel, and in particular, it is configured by disposing a core body forming a plurality of cells between a back plate and a perforated plate, and adhering a porous body to the perforated plate. The present invention relates to a soundproof structure and a soundproof panel using the same.

For a soundproof structure and a soundproof panel using the soundproof structure, quality improvement is required from various viewpoints such as weight, rigidity, and strength.

More specifically, a lighter soundproof panel is desirable from the viewpoints of ease of transportation and safety when it falls. Further, assuming that the soundproof panel is used as a simple wall or partition, a high-rigidity soundproof panel that is not easily changed in shape and can suppress change in acoustic performance is required. In addition, a soundproof panel having higher strength is desirable from the viewpoint of breakage resistance.

By the way, a porous body such as urethane foam and felt is usually used as a sound absorbing material for the soundproof structure. However, since the porous body is soft, it has no rigidity and it is difficult to secure strength. On the other hand, a sound absorbing material composed of a metal material, ceramics or the like may be used. Among them, there is a sound absorbing material which is a foam material and has high rigidity, but even such a sound absorbing material has a large weight and it is difficult to maintain strength.

Based on the above circumstances, various soundproof structures have been developed so far. As an example thereof, as described in Patent Document 1, a core body that constitutes a plurality of cells is arranged between a back plate and a perforated plate, and a porous body is arranged adjacent to the perforated plate. Examples include soundproof structures and soundproof panels.

The soundproof panel described in Patent Document 1 (indicated as “acoustic plate” in Patent Document 1) includes a woven fabric (porous body) made of a metal fiber or a fibrous material, and through holes having a predetermined diameter formed at regular intervals. Further, it is configured by laminating a perforated sheet (perforated plate), an intermediate honeycomb layer (core body), and a lower layer (back plate). With such a structure, it is possible to realize a soundproof structure having a high sound absorbing property, a wide band sound absorbing characteristic, and a high rigidity.

In order to provide a soundproof structure having the above-mentioned laminated structure as a product, it is necessary to integrate members adjacent to each other in the soundproof structure by adhesion or the like (in other words, each constituent member is not easily detached). .. Here, as a configuration in which a porous body such as cloth and a member adjacent to the porous body are integrated by adhesion or the like in the soundproof structure, the configuration described in Patent Document 2 can be mentioned. Patent Document 2 describes a configuration in which a sheet-shaped material layer as a porous body and a base material are bonded with an adhesive.

JP, 2002-189475, A JP, 2008-155627, A

However, in the soundproof structure having a laminated structure such as the soundproof panel described in Patent Document 1, the porous body is generally adhered and fixed to the perforated plate by an adhesive or the like. However, as a result of intensive studies by the present inventors, the larger the area of the range in which the porous body is fixed to the perforated plate by adhesion or the like, the larger the soundproof performance of the soundproof panel including the porous body (specifically, sound absorption coefficient). It has become clear that
The configuration described in Patent Document 2 described above is one in which a sheet-like material as a porous body is bonded to a base material (for example, a non-woven board or the like) different from the perforated plate. Therefore, the bonding method and the like described in Patent Document 2 is not suitable for the above-described laminated soundproof structure, and it is difficult to apply the method as it is to the soundproof structure.
Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to solve the following objects.
Specifically, the present invention is capable of solving the problems of the above-mentioned conventional techniques and achieving both structural rigidity imparted by keeping a porous body on a perforated plate and soundproofing performance. An object is to provide a soundproof structure and a soundproof panel.

As described above, the soundproof structure that is formed by arranging the core bodies that form a plurality of cells between the back plate and the perforated plate and stacking the porous body on the perforated plate is relatively small and lightweight. However, it has a high rigidity and high strength structure.
Then, as a result of intensive studies to solve the above problems, the present inventors have found that the soundproof performance (sound absorbing performance) is impaired if the porous body is directly fastened to the perforated plate, and the porous body is The present invention has been completed by finding that the soundproofing performance is improved as the area of the perforated plate is reduced.
That is, the inventors have found that the above problems can be solved by the following configurations.

[1] A core body that constitutes a plurality of cells, a back plate that covers each opening surface of the plurality of cells in the thickness direction of the core body, and a core plate that is arranged on the opposite side of the back plate through the core body in the thickness direction. And, having a perforated plate in which the through holes are formed, a porous body that is in contact with the perforated plate in the thickness direction, and a fastening portion that fastens the porous body to a member other than the porous body, A soundproof structure, wherein the ratio of the area of the area where the porous body is retained by the retaining portion to the apertured plate to the contact area of the porous body with the apertured plate is 92% or less.

[2] The soundproof structure according to [1], which has a ratio of 46% or less.
[3] The soundproof structure according to [1] or [2], wherein the planar arrangement of the fastening portions is a pattern arrangement.
[4] The soundproof structure according to any one of [1] to [3], wherein the fastening portion is arranged along an edge of a contact portion of the porous body with the perforated plate.
[5] The soundproof structure according to any one of [1] to [4], wherein the porous body is made of cloth.
[6] The soundproof structure according to any one of [1] to [5], wherein the flow resistance of the porous body is 300 Pa·s/m or more and 1500 Pa·s/m or less.
[7] The soundproof structure according to any one of [1] to [6], wherein the surface density of the porous body is 20 g/m ² or more and 2000 g/m ² or less.
[8] The soundproof structure according to any one of [1] to [7], wherein the through holes have a diameter of more than 1 mm and 15 mm or less.
[9] The hole diameter of the end closer to the core body in the through hole and the hole diameter of the end further away from the core body in the through hole are different from each other, [1] to [8] The soundproof structure according to.
[10] The hole diameter of the through hole increases toward the end of the through hole farther from the core body, and the end of the through hole farther from the core body is directed toward the side where the sound source is located. The soundproof structure according to [9].
[11] In a state where the porous body and the perforated plate are stacked on the core body in the thickness direction, the porous body covers the opening surface of each of the plurality of cells on the side opposite to the back plate in the thickness direction[ The soundproof structure according to any one of 1] to [10].
[12] The porous body has a processed portion that has been processed to modify the properties of the porous body, and the flow resistance of the processed portion after processing is 300 Pa·s/m or more and 1500 Pa. The soundproof structure according to any one of [1] to [11], which has a s/m or less.
[13] A soundproof panel comprising the soundproof structure according to any one of [1] to [12].

ADVANTAGE OF THE INVENTION According to this invention, the soundproof structure and soundproof panel which can make the structural rigidity provided by keeping a porous body on a perforated plate, and soundproof performance are implement|achieved.

It is a fragmentary sectional view showing a soundproofing structure concerning one embodiment of the present invention. FIG. 2 is a top view schematically showing the soundproof structure shown in FIG. 1 by partially breaking it. It is a top view which shows the modification of the structure of a core body. It is a fragmentary sectional view of the soundproofing structure which replaced the arrangement position of a perforated plate and a porous body. FIG. 6 is a partial cross-sectional view of a soundproof structure in which a through-hole having a varying hole diameter is formed in a perforated plate. It is a figure which shows the 1st example of the arrangement pattern of a fastening part. It is a figure which shows the 2nd example of the arrangement pattern of a fastening part. It is a figure which shows the 3rd example of the arrangement pattern of a fastening part. FIG. 6 is a partial cross-sectional view of a soundproof structure in which a porous body is fastened to a back plate. It is a perspective view showing a soundproof panel concerning one embodiment of the present invention. It is a figure which shows the measurement result of the sound absorption coefficient in Example 1 (the 1). It is a figure which shows the measurement result of the sound absorption coefficient in Example 1 (the 2). It is a figure which shows the measurement result of the sound absorption coefficient in Example 1 (the 3). It is a figure which shows the correspondence of an area ratio and a sound absorption coefficient.

The soundproof structure and soundproof panel of the present invention will be described in detail below based on the preferred embodiments shown in the accompanying drawings.
The description of the constituent elements described below may be made based on a typical embodiment of the present invention, but the present invention is not limited to such an embodiment.

In addition, in the present specification, the numerical range represented by "to" means a range including the numerical values before and after "to" as the lower limit value and the upper limit value.
In addition, in the present specification, “orthogonal” and “parallel” include a range of error allowed in the technical field to which the present invention belongs. For example, “orthogonal” and “parallel” mean that the angle is within ±10° with respect to strict orthogonality or parallelism. Here, the error with respect to strict orthogonality or parallelism is preferably 5° or less, and more preferably 3° or less.
In addition, in the present specification, “identical” and “identical” include an error range generally accepted in the technical field to which the present invention belongs. Further, in the present specification, when referring to “all”, “any” or “entire surface” and the like, in addition to the case of 100%, the error range generally accepted in the technical field to which the present invention belongs is included. The case where it is 99% or more, 95% or more, or 90% or more is included.

Furthermore, “soundproof” in the present invention is a concept including both “sound insulation” and “sound absorption”. Here, “sound insulation” means “sound shielding”, in other words, “sound is not transmitted”, and mainly means reflecting sound (sound). Further, "sound absorption" means "to reduce reflected sound", and means to absorb sound (sound) for easy understanding. Further, in the present invention, since the back plate described later is used, the transmitted sound is small and the reflected sound becomes a problem. In such a system, it is appropriate to use an index evaluated from the viewpoint of "sound absorption" described above (that is, an index of low reflected sound). Therefore, in the following, "soundproof" is mainly "sound absorption", and "sound insulation" and "sound absorption" are called to distinguish them.

<<Outline of Soundproof Structure of the Present Invention>>
First, the outline of the soundproof structure of the present invention will be described.
The soundproof structure of the present invention includes a core body that constitutes a plurality of cells, a back plate that covers the opening surfaces of the plurality of cells in the thickness direction of the core body (hereinafter referred to as the thickness direction), and a core body in the thickness direction. It has a perforated plate disposed on the side opposite to the back plate through the, and a porous body that is in contact with the perforated plate in the thickness direction (see, for example, FIG. 1 ).

Further, the soundproof structure of the present invention has a retaining portion for retaining the porous body on a member other than the porous body, specifically, the core body, the back plate or the perforated plate (see, for example, FIGS. 4 to 6). ). As a method for fastening the porous body to the member other than the porous body by the fastening portion, for example, a method using an adhesive and an adhesive tape, a method using a stapler and a thumbtack, a method by stitching, a surface fastener, etc. are used. The method includes a fitting method using a frame material and the like, a method including pushing into a gap, a method using a magnet and the like.

The core body and the back plate form a resonance structure, more specifically, an air column resonance structure. This resonance structure exhibits high sound absorption performance in a relatively low frequency range. Through holes are formed in the perforated plate. The porous body is breathable and has a large number of fine pores formed therein. Each of the micropores extends from the front side to the back side of the porous body, and forms a ventilation portion of the porous body. Then, the porous body functions as a sound absorbing body, and imparts sound absorbing performance in the medium and high frequency bands to the soundproofing structure of the present invention.

The porous body may be in contact with the perforated plate on the side opposite to the core body in the thickness direction, or may be in contact with the perforated plate while being sandwiched between the core body and the perforated plate. May be.

The soundproof structure of the present invention configured as described above has both the sound absorbing effect of the air column resonance structure formed by the core body and the back plate and the sound absorbing effect of the porous body. As a result, according to the soundproof structure of the present invention, the soundproof structure has high rigidity and high strength while being lightweight, and has a relatively small (compact) structure, so that a relatively low frequency sound such as a human voice can be obtained. It is possible to absorb sound in a wide band.

Further, in the soundproofing structure of the present invention, the ratio of the area of the range in which the porous body is fastened to the perforated plate by the fastening portion to the contact area of the porous body with the perforated plate is 92% or less. As a result, according to the soundproof structure of the present invention, it is possible to favorably secure structural rigidity and soundproof performance.

More specifically, in order to manufacture the soundproof structure having the above-described laminated structure, it is necessary to integrate members adjacent to each other in the thickness direction (for example, a porous body and a perforated plate) by bonding or the like. However, the present inventors have confirmed that when the porous body is directly fastened to the perforated plate, the soundproof performance (sound absorbing performance) of the soundproof structure is impaired. Further, the present inventors conducted an experiment in which the soundproof structure was switched for each element (member) to confirm the sound absorption performance, and from the result of the experiment, a state in which the porous body was fastened to the perforated plate Was identified as the main cause of the sound absorption performance deterioration.

Here, the mechanism by which the porous body functions as a sound absorbing body will be described. There are mainly two sound absorbing mechanisms of the porous body. The first sound absorbing mechanism is that when sound passes through the fine pores in the porous body, friction is generated, and the sound energy is converted into heat energy to absorb sound. The second sound absorbing mechanism is that sound that has entered the porous body vibrates the entire porous body as a string or a film to convert sound energy into mechanical energy and absorb sound.

The soundproof structure of the present invention is considered to be involved in the above two sound absorbing mechanisms. Specifically, regarding the first mechanism, when the porous body and the perforated plate are simply overlapped with each other, a ventilation portion is formed in the porous body in a portion adjacent to the through hole of the perforated plate. It In addition, even in the part of the porous body that is out of the through-holes of the perforated plate (that is, the part that is adjacent to the plate part of the perforated plate), the non-perforated part (material part) of the porous body is bent and expanded, etc. A part is formed. However, if the porous body is fastened to the perforated plate, the non-perforated portion of the porous body is prevented from being bent or expanded and contracted in the portion of the porous body adjacent to the plate portion of the perforated plate. As a result, the part where the air passage is formed is limited to a part of the porous body (specifically, the part adjacent to the through hole of the perforated plate), which reduces the sound absorbing performance of the porous body. Will end up.

Regarding the second mechanism, when the porous body and the perforated plate are simply overlapped, the degree of freedom of vibration in the porous body becomes relatively high. However, if the porous body is retained on the perforated plate, the degree of freedom of vibration in the porous body decreases, and as a result, the sound absorbing performance of the porous body deteriorates.

Considering the above points, it is considered preferable to minimize the range in which the porous body is directly fastened to the perforated plate from the viewpoint of suppressing the deterioration of the sound absorbing performance. On the other hand, in providing the soundproof structure as a product, the contact state between the porous body and the perforated plate is maintained and both members are well integrated (in other words, the detachment of the porous body is suppressed. )There is a need. With respect to these contents, no measures are taken in the soundproof panel of Patent Document 1 having the same laminated structure as that of the present invention, and no particular consideration is given to reduction in sound absorbing performance. As a result, the porous body is retained on the perforated plate over substantially the entire contact surface of the porous body with the perforated plate, resulting in a significant decrease in sound absorbing performance.

The bonding method described in Patent Document 2 is a method of bonding a base material having felts laminated to a sheet-like body, and is not a method of bonding a perforated plate and a porous body. Therefore, the bonding method described in Patent Document 2 cannot be applied as it is to a structure in which a core body, a back plate, a perforated plate and a porous body are laminated, and is not suitable for the above laminated structure. It is a thing.

On the other hand, in the soundproof structure of the present invention, the porous body is fastened to a member other than the porous body by the fastening portion, and the porous body is retained by the fastening portion with respect to the contact area with the perforated plate in the porous body. The ratio of the area retained in the perforated plate is set to 92% or less. That is, the sound absorbing performance of the porous body is gradually recovered by reducing the area of the range where the porous body is retained by the perforated plate. In view of that, in the present invention, the range in which the porous body is retained on the perforated plate in the range in which the structural rigidity imparted by retaining the porous body with the perforated plate can be maintained. It was decided to reduce the area of.

More specifically, by setting the above ratio to 92% or less, the maximum sound absorption coefficient obtained when the conditions such as the maximum frequency are changed exceeds 0.8 (for example, FIGS. 11A to 11C, and FIG. 12). Explaining the technical significance of the maximum sound absorption coefficient exceeding 0.8, the maximum sound absorption coefficient increases from 0.6 to 0.7 when the change in auditory sensation (hearing difference) with respect to the increase in the maximum sound absorption coefficient is evaluated. In the case of doing so, since the hearing difference (dB difference) is less than 3, it cannot be said to be a clear hearing difference. On the other hand, when the maximum sound absorption coefficient is increased from 0.7 to 0.8, the hearing difference (dB difference) becomes 3.5, so that the difference can be perceived by human hearing. Therefore, if the maximum sound absorption coefficient exceeds 0.8, a hearing difference (dB) that can be clearly perceived by human hearing can be obtained. In addition, when the maximum sound absorption rate is increased from 0.8 to 0.9, the hearing difference (dB difference) becomes 6, and the hearing difference becomes clearer. Further, the maximum sound absorption coefficient=0.8 is adopted as a standard value for a general high sound absorption coefficient.
Further, according to the study by the present inventors, the lower the above ratio, the higher the maximum sound absorption coefficient becomes, and when the above ratio becomes 62% or less, the maximum sound absorption coefficient becomes 0.9 or more, and the above ratio becomes 46%. In the following, it was revealed that the maximum sound absorption coefficient reached about 1 (for details, see the section of Examples described later).

As described above, according to the soundproof structure of the present invention, it is possible to favorably secure the structural rigidity imparted by fastening the porous body to the perforated plate and the soundproof performance. ..

Here, the "contact area of the porous body with the perforated plate" means the perforated plate (strictly speaking, the plate excluding the through holes of the perforated plate) among the surfaces facing the perforated plate of the porous body. (Part) is the area of the part that is in contact with. Further, "the area of the range in which the porous body is fastened to the perforated plate by the retaining portion" is the area of the range of the porous body directly fixed to the perforated plate by the retaining portion. In other words, it is the area of the range in which the fixing force of the fastening portion extends to the porous body.

More specifically, for example, when the fastening portion is a layer (adhesive layer) made of an adhesive or an adhesive tape interposed between the porous body and the perforated plate, the adhesive layer is a porous body or an adhesive tape. The area of the range in contact with the perforated plate corresponds to the "area of the range in which the porous body is fastened to the perforated plate by the fastening portion".

When the fastening portion is a stapler core that bundles the porous body and the perforated plate, or when the suture thread is sewn to the porous body and the perforated plate, the core or the suture thread contacts the porous body. The area of the part (specifically, the part of the core or suture that penetrates the porous body and the part that is passed between the penetrating parts) is defined as "the porous body is It corresponds to the area of the area that is fastened to the perforated plate.

Further, in the case where the retaining portion is a pushpin pierced into the porous body and the perforated plate, the range in which the gripping portion of the pushpin contacts the porous body (that is, the porous body is pressed by the gripping portion Area) corresponds to the “area of the area where the porous body is fastened to the perforated plate by the fastening portion”.

Further, when the retaining portion is an N-pole magnet or an S-pole magnet provided between the porous body and the perforated plate, the area of the portion where the magnet is bonded to the porous body is The area of the area that is fastened to the perforated plate by the section".
Further, when the fastening portion has a fitting structure provided on the frame member or the like, the area of the portion of the porous body fitted in the fitting portion provided on the frame material is The area of the area that is fastened to the perforated plate by the section".
In addition, when the fastening portion is a gap into which a part of the porous body is pushed, the area of the portion of the porous body pushed into the gap is "the porous body is fastened to the perforated plate by the fastening portion. The area of the area that is In this case, since the porous body is fastened at the portion not in contact with the perforated plate, the area of the range where the porous body is fastened to the perforated plate by the fastening portion becomes zero.

Further, when the fastening portion is a surface fastener provided between the porous body and the perforated plate, the area of the portion where the surface fastener is adhered to the porous body is "the porous body has a perforation by the fastening portion. It corresponds to the area of the area that is fastened to the board.
When the fastening portion fastens the porous body to the core body or the back plate (for example, the configuration shown in FIG. 9), the area of the range where the porous body is fastened to the perforated plate by the fastening portion becomes 0. ..

Although the structure and effects of the soundproof structure of the present invention have been described above, the soundproof structure of the present invention can be used for various purposes, for example, a house, a hall, an elevator, a classroom, an office, It is used for building various sound environments such as conference rooms, schools, nurseries and kindergartens, other buildings (specifically, factories and animal sheds, etc.), and structures other than buildings.

Further, the soundproof structure of the present invention can be used for applications other than the above, and for example, it can be used as a distribution material such as an acoustic plate of an engine of an aircraft, an interior material of an automobile, a box material, a packing material, and the like. it can. Further, the soundproof structure of the present invention can be used as a material for copying machines, blowers, air conditioners, ventilation fans, pumps, generators, ducts, and the like. Furthermore, the soundproofing structure of the present invention includes various types of industrial equipment that emits sound, such as a coating machine, a rotating machine, and a carrier machine; vehicles such as automobiles and trains; and transportation equipment such as aircraft; and It can be used for general household appliances such as refrigerators, washing machines, dryers, televisions, copiers, microwave ovens, game machines, air conditioners, fans, personal computers, vacuum cleaners, air cleaners, and ventilation fans.
In addition, the soundproof structure of the present invention is appropriately arranged at a position where the sound generated from the noise source passes in the above-described various devices.

<<Structural Example of Soundproof Structure of the Present Invention>>
Next, a configuration example of the soundproof structure of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a partial cross-sectional view showing a soundproof structure (hereinafter, soundproof structure 10) according to an embodiment of the present invention. It should be noted that FIG. 1 also shows an enlarged view of a part of a porous body described later. FIG. 2 is a top view schematically showing the soundproof structure 10 by partially breaking it. For convenience of illustration, the fastening portion is omitted in FIG.

In FIG. 1, the thickness direction of the soundproof structure 10 is indicated by an arrow. Here, the thickness direction of the soundproof structure 10 corresponds to the thickness direction of the core body 12 described later, and in the following description, both thickness directions will be collectively referred to as "thickness direction".

In addition, in FIG. 2, in order to facilitate understanding of the structure of the soundproof structure 10, the part of the soundproof structure 10 from which the perforated plate 20 and the porous body 24, which will be described later, are removed is shown in the left side of FIG. The parts from which only the body 24 has been removed are shown in the central part of FIG. 2, respectively.

As shown in FIGS. 1 and 2, the soundproof structure 10 is configured by stacking a porous body 24, a perforated plate 20, a core body 12 and a back plate 18 in the thickness direction. .. Further, the porous body 24 is fastened to either the perforated plate 20, the core body 12 or the back plate 18 by the fastening portion 28.

As shown in FIG. 2, the core body 12 is a member that constitutes a plurality of cells 14. Each cell 14 is a frame having a cylindrical opening 14a along the thickness direction and a partition wall 14b surrounding the opening. Further, both end surfaces of each of the plurality of cells 14 in the thickness direction are open surfaces.

As shown in FIG. 1, the back plate 18 is a plate that covers the opening surface (strictly speaking, the end surface on the back side) of each of the plurality of cells 14 in the thickness direction. In the configuration shown in FIG. 1, the back plate 18 is joined to one end surface of the core body 12 in the thickness direction, and closes the opening 14 a of each cell 14.

As shown in FIG. 1, the perforated plate 20 is superposed on the core body 12 at a position on the side opposite to the back plate 18 (that is, on the side closer to the sound source) with the core body 12 in the thickness direction. In the configuration shown in FIG. 1, the perforated plate 20 is joined to the other end face of the core body 12 in the thickness direction (the end face opposite to the side to which the back plate 18 is joined), and the back plate 18 The opposite side covers the opening surface of each of the plurality of cells 14. Further, as shown in FIG. 2, the perforated plate 20 has through holes 22 formed at positions corresponding to each of the plurality of cells. Each through hole 22 is provided at a position communicating with the opening 14 a of the cell 14.

The porous body 24 is in contact with the perforated plate 20 in the thickness direction. In the configuration shown in FIG. 1, the porous body 24 is adjacent to the perforated plate 20 on the side opposite to the core body 12, and forms the outermost layer of the soundproof structure 10. Further, the porous body 24 has air permeability, and inside thereof, fine pores 26 forming a ventilation portion are formed. Further, the contact state between the porous body 24 and the perforated plate 20 is stably maintained by the retaining portion 28 retaining the porous body 24 at a predetermined position. The porous body 24 is preferably made of cloth. Here, the cloth refers to a fiber aggregate including a non-woven fabric, a woven fabric, a knitted fabric and the like. The material of the cloth may be natural thread, synthetic thread, metallic material or the like.

Hereinafter, each component of the soundproof structure 10 will be individually described.
[Core body]
The core body 12 is sandwiched between the back plate 18 and the perforated plate 20 in the thickness direction. Each opening 14 a of the plurality of cells 14 constituted by the core body 12 is closed by the back plate 18 and the perforated plate 20. That is, on the back side of the through-hole 22 of the perforated plate 20, the opening 14a of each cell 14 is a closed space, and a back space is formed. Then, each cell 14 of the core body 12 and the back plate 18 cooperate to form an air column resonance structure.

Further, as shown in FIG. 1, a plurality of through holes 22 are formed in the perforated plate 20 so that one of the through holes 22 of the perforated plate 20 communicates with the opening 14a of one cell 14. Is preferred. That is, it is preferable that the plurality of through holes 22 formed in the perforated plate 20 are arranged in a one-to-one correspondence with one of the openings 14 a of the plurality of cells 14. In this case, if the openings 14a of the plurality of cells 14 are regularly arranged, the plurality of through holes 22 should also be regularly arranged in the perforated plate 20 according to the regularity of the arrangement of the openings 14a. become.
Further, even when each through hole 22 is arranged so that a plurality of through holes 22 correspond to one cell 14, the same effect as above can be obtained. That is, for example, it is possible to arrange the through holes 22 periodically so that the opening 14a of one cell 14 and the three through holes 22 communicate with each other. However, considering the time and effort required to form the through holes 22 in the perforated plate 20, it is more cost effective to form one large hole than to form a plurality of holes. It is desirable that one through hole 22 corresponds.
In addition, the through holes 22 do not have to correspond one-to-one with respect to all the cells 14, and if the number of the through holes 22 corresponds to a certain number of cells, the same effect as above can be obtained. Specifically, if 50% or more of all cells 14 have corresponding numbers of through holes 22, the same effect as described above can be obtained. It is preferable that the number of the through holes 22 corresponds to 70% or more, and more preferably 90% or more of the cells 14.

The arrangement of the openings 14a of the cells 14 in the core body 12 and the positional relationship between the openings 14a of the cells 14 and the through holes 22 of the perforated plate 20 are not limited to those described above. For example, two or more through holes 22 of the perforated plate 20 may be arranged so as to correspond to the opening 14a of one cell 14. Further, the openings 14 a of the cells 14 do not have to be regularly arranged in the core body 12.

From the viewpoint of ensuring the strength of the soundproof structure 10, the core body 12 is preferably a honeycomb core having a honeycomb structure. That is, the shape of the plurality of cells 14 is preferably a honeycomb (regular hexagon) shape in plan view as shown in FIG. However, the structure of the core body 12 is not limited to the honeycomb structure, and the cell shape may be a substantially rectangular shape in a plan view like a grating, or the cell shape may be a rectangular shape in a plan view like an expanded metal. It may have a substantially rhombic shape. Alternatively, as shown in FIG. 3, the structure of the core body 12 may be a structure in which a plurality of corrugated slate are arranged so that the front and back directions are alternately interchanged, and the cell shape is a substantially spindle shape in plan view. Good. FIG. 3 is a top view showing a modified example of the structure of the core body 12.

The structure of the core body 12, that is, the shape of each cell 14 is not limited to the above contents, and includes a special quadrangle such as a circle, an ellipse, a parallelogram, or a trapezoid, a triangle, a pentagon, and an octagon. It may be polygonal or irregular. Further, the shape of the cells 14 may be the same (constant) among all the cells 14, or may be different among the cells 14.

Incidentally, the size of the opening 14a of the cell 14 may be defined as the diameter or the length of the longest diagonal in the regular polygon when the planar shape of the opening 14a is a regular polygon such as a circle or a square. it can. Further, when the planar shape of the opening 14a is polygonal, elliptical, or irregular, it can be defined as a circle equivalent diameter. Here, the “circle equivalent diameter” is a diameter when converted into circles having the same area.

Supplementally regarding the cells 14 of the core body 12, the size of the opening 14a of each cell 14 (that is, the diameter of the opening 14a, the length of the longest diagonal, and the equivalent circle diameter) is as shown in FIG. The diameter is larger than the diameter of the through hole 22 of the perforated plate 20. By the way, the size of the opening 14a is preferably 1.0 mm to 500 mm, more preferably 5 mm to 250 mm, and particularly preferably 10 mm to 100 mm. Here, the reason why the size of the opening 14a is preferably 1.0 mm to 500 mm is that when it is smaller than 1.0 mm, the air viscous resistance in the inner wall surrounding the opening 14a is significantly increased, and the sound absorbing effect is reduced. In addition, it is difficult to manufacture the core body 12. Moreover, if the size is larger than 500 mm, the rigidity of the core body 12 is significantly reduced.

The size of the opening 14a of each cell 14 may be the same (constant) among all the cells 14, and the size of the opening 14a of some cells 14 may be the same as that of the other cells 14. May be different in size. Further, the shape and size of the opening 14a (in other words, the shape and the plane size of the cell 14) are not particularly limited, and may depend on the plane shape and the size (area) of each of the back plate 18 and the perforated plate 20. And set appropriately.

Further, the ratio of the openings 14a of the cells 14 to the end surface of the core body 12 in the thickness direction (opening occupancy ratio) is higher than the opening ratio of the through holes 22 in the perforated plate 20 (the opening ratio will be described later). It's getting bigger.

The thickness of the core body 12 is equal to the distance between the back plate 18 and the perforated plate 20. The thickness of the core body 12 is not particularly limited and may be appropriately set depending on the place and environment in which the soundproof structure 10 of the present invention is used, but is preferably 1.0 mm to 200 mm, for example. It is more preferably 5 mm to 100 mm, particularly preferably 10 mm to 50 mm. Here, the reason why the thickness of the core body 12 is preferably 1.0 mm to 200 mm is that when the thickness is less than 1.0 mm, the rigidity of the core body 12 is significantly reduced, and when it is more than 200 mm, the soundproof structure 10 is provided. However, the size may be increased, and it may not be possible to dispose depending on the place.

The material of the core body 12 is not particularly limited as long as it is lightweight, has high rigidity, and exhibits the function of the core body 12 well. That is, the core body 12 supports the perforated plate 20 and the porous body 24, maintains a constant gap between the back plate 18 and the perforated plate 20, and forms a columnar resonance structure together with the back plate 18. Any material may be used as long as it is configured, and the material of the core body 12 can be freely selected so far.

Explaining in detail the material of the core body 12, the material of the core body 12 may be, for example, a combustible material. Here, the flammable material refers to a material other than the flame-retardant material described later, and examples thereof include paper materials, wood, and resin materials such as synthetic resins. Examples of the paper material include Japanese paper, paper, a corrugated board structure using a pulp raw material, a honeycomb corrugated board structure, and a board. Examples of the resin material include PET (polyethylene terephthalate), TAC (triacetyl cellulose), PVDC (polyvinylidene chloride), PE (polyethylene), PVC (polyvinyl chloride), PMP (polymethylpentene), COP (cycloolefin). Polymer), ZEONOR, polycarbonate, PEN (polyethylene naphthalate), PP (polypropylene), PS (polystyrene), PAR (polyarylate), aramid, PPS (polyphenylene sulfide), PES (polyether sulfone), nylon, PEs ( Polyester), COC (Cyclic Olefin Copolymer), Diacetylcellulose, Nitrocellulose, Cellulose derivative, Polyamide, Polyamideimide, POM (Polyoxymethylene), PEI (Polyetherimide), PMMA (Polymethylmethacrylate), Polyrotaxane (Slide) Ring material) and polyimide. Furthermore, a so-called Pradan structure mainly using polypropylene or polycarbonate can be used.

However, the material of the core body 12 may be, for example, a flame retardant material, without being limited to the above contents. Here, the flame-retardant material, when used as a building material, is a non-combustible material specified by Article 2 No. 9 of the Building Standards Act, a quasi-specified by Article 1 No. 5 of the Enforcement Order of the Building Standards Act. It refers to non-combustible materials and flame-retardant materials specified in Article 1-6 of the Enforcement Order. These materials should not be burned for more than 5 minutes after the start of heating when heat from a normal fire is applied, no deformation, melting, cracking, or other damage harmful to fire prevention, or harmful for evacuation. It is necessary to satisfy the following three points: no generation of smoke or gas. Examples of the flame-retardant material include materials such as metal materials, inorganic materials, flame-retardant plywood, flame-retardant fiber board, and flame-retardant plastic board. Examples of the metal material include aluminum, steel, titanium, magnesium, tungsten, iron, steel, chromium, chromium molybdenum, nichrome molybdenum, and alloys thereof. Examples of the inorganic material include glass, concrete, gypsum board, sapphire, and ceramics. In addition, it can be used as a flame retardant material by coating a flammable material with aramid resin or the like.

Examples of the material of the core body 12 other than the above include carbon fiber reinforced plastics (CFRP), carbon fibers, and materials containing carbon fibers such as glass fiber reinforced plastics (GFRP). To be
In addition, the core body 12 may be configured by combining a plurality of kinds of the materials mentioned above.

By the way, among the above-mentioned materials for the core body 12, the paper material, the metal material and the resin material are preferable, and the paper material is more preferable because it is lighter weight and can be easily incinerated. Further, a paper material coated with an aramid resin is more preferable because it gives fire resistance.

The thickness (plate thickness) of the material itself of the core body 12 is not particularly limited, but is preferably 0.001 mm (1 μm) to 5 mm, for example, 0.01 mm (10 μm) to 2 mm. Is more preferable, and 0.1 mm (100 μm) to 1.0 mm is particularly preferable. Here, the reason why the plate thickness of the material of the core body 12 is preferably 0.001 mm (1 μm) to 5 mm is that the rigidity of the core body 12 cannot be sufficiently secured when it is less than 0.001 mm (1 μm). .. Further, if it exceeds 5 mm, the core body 12 becomes extremely heavy, which impairs the lightness of the core body 12.

Further, among the plurality of cells 14 included in the core body 12, at least some of the cells 14 have, in the openings 14a, a sound absorbing material made of a fiber such as a porous sound absorbing material, for example, woven fabric, knitted fabric, non-woven fabric or felt. Alternatively, a foam material such as porous urethane may be arranged. Further, a sound absorbing material may be interposed between the core body 12 and the perforated plate 20. Further, as shown in FIG. 3, the perforated plate 20 may be located at the outermost layer of the soundproof structure 10x, and the porous body 24 may be interposed between the perforated plate 20 and the core body 12 in the thickness direction. .. FIG. 3 is a partial cross-sectional view of the soundproof structure 10x in which the arrangement positions of the perforated plate 20 and the porous body 24 are exchanged, and is a view corresponding to FIG.

Further, the core body 12 is preferably fixed to the back plate 18, the perforated plate 20 or the porous body 24 without any gap. Regarding the method of fixing the back plate 18 and the perforated plate 20 or the porous body 24 to the core body 12, any method may be used as long as the fixed state can be favorably held, and there is no particular limitation. It is not something that will be done. Examples of the fixing method include a method using an adhesive and a method using a physical fixing tool.

Explaining a fixing method using an adhesive, the adhesive is applied to both end surfaces of the core body 12 (in other words, opening surfaces of the plurality of cells 14) in the thickness direction, and the back plate 18 is placed on one end surface. Then, the perforated plate 20 or the porous body 24 is placed on the other end surface, and each is fixed to the core body 12. Examples of the adhesive include epoxy adhesives (Araldite (registered trademark) (manufactured by Nichiban Co., Ltd.), cyanoacrylate adhesives (Aron Alpha (registered trademark) (manufactured by Toagosei Co., Ltd.), and acrylic adhesives. An adhesive or the like can be used.

Explaining a method using a physical fixture, the back plate 18 and the perforated plate 20 (or the porous body 24) arranged so as to sandwich the core body 12 in the thickness direction are used as the core body 12 and the rod. And a fixing member (not shown), and the fixing member is fixed to the core body 12 by a fixing member (fastener) such as a screw and a screw.

[Back plate]
The back plate 18 is a plate member that closes the opening surface of each of the plurality of cells 14 included in the core body 12 on the back surface side (that is, the side opposite to the side where the perforated plate 20 is provided). That is, as shown in FIG. 1, the back plate 18 covers the back surface of the core body 12 and is arranged in the thickness direction with a gap from the perforated plate 20.

The thickness of the back plate 18 is not particularly limited, but is preferably 0.001 mm (1 μm) to 5 mm, more preferably 0.01 mm (10 μm) to 2 mm, and 0.1 mm, for example. (100 μm) to 1.0 mm is particularly preferable.

The planar shape and size (planar size) of the back plate 18 are not particularly limited as long as they can cover the surface of the core body 12 on the back side, and other members in the soundproof structure 10 (core body 12). It may be appropriately set according to the planar shape and size of the perforated plate 20 and the porous body 24).

The material of the back plate 18 is not particularly limited, and the same material as the material of the core body 12 described above can be used. More specifically, examples of the material of the back plate 18 include paper materials, various metals such as aluminum and iron, and various resin materials such as polyethylene terephthalate (PET) and polypropylene (PP).

The back plate 18 only needs to be capable of sandwiching the core body 12 together with the perforated plate 20, and for example, a housing or cover of a device in which the soundproof structure 10 is installed may be used as the back plate 18. .. Alternatively, a room wall or the like may be used as the back plate 18. That is, for example, when the structure including the porous body 24, the perforated plate 20, and the core body 12 is installed on the wall, the above-mentioned structure is arranged so that the surface on the back side of the core body 12 contacts the wall. The wall may function as the back plate 18 by being arranged.

[Perforated plate]
The perforated plate 20 is made of a plate material having a slight thickness and has a plurality of through holes 22 penetrating therethrough. Here, in the configuration of FIG. 1, the plurality of through holes 22 formed in the perforated plate 20 are covered with the porous body 24 arranged on the perforated plate 20 and are invisible. Such an aspect is preferable in terms of the appearance (design) of the soundproof structure 10. Hereinafter, unless otherwise specified, the configuration of FIG. 1, that is, the configuration in which the porous body 24 is arranged on the perforated plate 20 will be described as a premise.

The formation position of the through hole 22 in the perforated plate 20 is set corresponding to the opening 14a of the cell 14 of the core body 12, as described above. More specifically, a closed space (air layer) surrounded by the partition wall 14b of each cell 14 of the core body 12 and the back plate 18 is formed on the back side of each through hole 22. In this closed space, air column resonance occurs at a frequency according to the length (back surface distance) of the closed space. That is, each cell 14 having the opening 14a and the back plate 18 that closes the opening surface on the back side of each cell 14 constitute an air column resonance structure. Further, the through hole 22 of the perforated plate 20 communicating with the above-mentioned closed space is formed to be large enough not to interfere with air column resonance. Strictly speaking, the diameter of the through hole 22 and the induction of Helmholtz resonance due to the expansion and compression of the volume of the closed space are small, and the through hole 22 is formed under the condition that the air column resonance due to the back distance is predominant.

The through holes 22 may be regularly arranged in the perforated plate 20 or may be randomly arranged. However, the arrangement pattern (arrangement rule) of the openings 14 a of the cells 14 in the core body 12 is arranged. It is preferable that they are regularly arranged according to. Further, only one through hole 22 may be formed in the perforated plate 20.

Further, the perforated plate 20 may be any one as long as the through holes 22 do not induce Helmholtz resonance and can properly support the porous body 24. As described above, the thickness of the perforated plate 20 is not particularly limited, but is preferably 0.001 mm (1 μm) to 5 mm, more preferably 0.01 mm (10 μm) to 2 mm, It is particularly preferable that the thickness is 0.1 mm (100 μm) to 1.0 mm.

Further, the planar shape and size (planar size) of the perforated plate 20 are not particularly limited and may be appropriately set according to the place and environment where the soundproof structure 10 is used.

The shape of the through hole 22 is preferably circular in a plan view, but is not limited to this. The shape of the through hole 22 is a shape other than a circle, for example, a square, a rectangle, a rhombus, or another quadrangle such as a parallelogram and a trapezoid, a polygon including an triangle, a pentagon, and a hexagon, an oval, or an irregular shape. May be Further, the shape of the through holes 22 may be the same (constant) among all the through holes 22, or may be different among the through holes 22.

Further, the hole diameter (specifically, the diameter and the opening width) of the through hole 22 needs to be set within a range that does not hinder the air column resonance that occurs on the back side of the through hole 22 (that is, does not cause the Helmholtz resonance). .. Here, the hole diameter of the through hole 22 can be defined similarly to the size of the opening 14a of the cell 14 of the core body 12.

The diameter of the through hole 22 is preferably more than 1.0 mm and 15 mm or less. The reason why the preferable range of the hole diameter of the through hole 22 is set to the above range is that when the hole diameter of the through hole 22 is 1.0 mm or less, the viscous resistance of the inner wall surrounding the through hole 22 increases, resulting in a large decrease in the sound absorbing characteristic. This is because there is a risk of Further, if the diameter of the through hole 22 is more than 15 mm, it is difficult to secure the rigidity of the soundproof structure 10. However, since the through hole 22 can have various shapes, the lower limit and the upper limit of the hole diameter are not necessarily strictly determined, and can be designed with a certain degree of tolerance.

The hole diameters of the through holes 22 may be the same (constant) among all the through holes 22, or the hole diameters of some of the through holes 22 may be different from the hole diameters of the other through holes 22. That is, the perforated plate 20 may be provided with two or more kinds of through holes 22 having different hole diameters. When the pore diameters are distributed, the average pore diameter may be adopted as the pore diameter so as to satisfy the above size.

The through hole 22 may be a straight hole having a uniform hole diameter over the entire length of the through hole 22, or may be a hole whose hole diameter changes along the depth direction of the through hole 22. .. That is, as shown in FIG. 5, the hole diameter at the end closer to the core body 12 in the through hole 22 and the hole diameter at the end further away from the core body 12 may be different from each other. FIG. 5 is a partial cross-sectional view of the soundproof structure 10y in which the through hole 22 having a variable hole diameter is formed in the perforated plate 20.

Here, as the through hole 22 whose hole diameter changes, for example, the tapered through hole 22 illustrated in FIG. 5 can be cited. Regarding the tapered through hole 22, it is desirable that the diameter of the through hole 22 gradually increases toward the end farther from the core body 12. Further, from the viewpoint of easily guiding the sound from the sound source into the cell 14 having the air column resonance structure and effectively absorbing the sound, as shown in FIG. 5, the end of the through hole 22 that is farther from the core body 12 is formed. However, it is desirable that the sound source is directed to the side where it is located. However, the shape is not limited to this, and the through hole 22 may have an inverted taper shape obtained by vertically inverting the shape shown in FIG.
Incidentally, the tapered through hole 22 can be formed by a physical method such as punching, and the through hole 22 formed by such a method is preferable because it has many acoustic advantages.

In addition, as the size of the hole diameter of the through hole 22 in which the hole diameter changes, an average value of the hole diameters of the respective portions of the through hole 22 may be adopted.

Further, the aperture ratio of the through hole 22 in the perforated plate 20 is set within a range that does not hinder the air column resonance generated on the back side of the through hole 22 (that is, does not cause Helmholtz resonance), like the hole diameter of the through hole 22. There is a need. Here, the aperture ratio of the through hole 22 in the perforated plate 20 is the ratio of the area of the through hole 22 to the area of the closed space (air layer) behind the through hole 22, that is, the opening of the cell 14 of the core body 12. It can be defined as the ratio of the area of the through hole 22 to the cross-sectional area of the portion 14a (the area of the cross section whose normal line is the thickness direction).

In addition, when the cross-sectional area of the opening 14a of the cell 14 of the core body 12 is not uniform, or when the area of the through hole 22 is not uniform, the average opening ratio of the through hole 22 is set as the opening ratio of the through hole 22. To use. Here, the average opening ratio of the through holes 22 can be obtained as a ratio of the total area of all the through holes 22 to the total area of all the opening portions 14 a in the core body 12. The total area of all the openings 14a may be obtained by obtaining the number and the average area of all the openings 14a within the predetermined range of the core body 12, and by calculating the product of the number and the average area. The total area of all the through holes 22 may be obtained by calculating the number and the average area of all the through holes 22 within the predetermined range of the perforated plate 20, and calculating the product of the number and the average area.

Then, the aperture ratio of the through hole 22 described above needs to be 1.0% or more, preferably 5.0% or more, for the reason that air column resonance generated on the back side of the through hole 22 is not hindered. It is more preferably at least 10%, further preferably at least 20%. From the viewpoint of rigidity, the aperture ratio is preferably 90% or less, more preferably 80% or less, further preferably 70% or less, and particularly preferably 50% or less.

The material of the perforated plate 20 is not particularly limited as long as it can support the porous body 24 on its surface and can sandwich the core body 12 together with the back plate 18, and specifically, The same material as the material of the core body 12 can be used. More specifically, examples of the material of the perforated plate 20 include paper materials, various metals such as aluminum and iron, and various resin materials such as polyethylene terephthalate (PET) and polypropylene (PP).

In the configuration described so far, the core body 12, the back plate 18 and the perforated plate 20 are separate members, but at least two of these members and the porous body 24 are integrated. (Strictly speaking, it may be an integrally molded product). For example, using a 3D printer or the like, the perforated plate 20 and the core body 12 may be integrally formed, or the core body 12 and the back plate 18 may be integrally formed, or the porous body 24. The perforated plate 20, the core body 12, and the perforated plate 20, the core body 12, and the back plate 18 may be integrally formed. Further, the entire soundproof structure 10 (that is, the porous body 24, the perforated plate 20, the core body 12, and the back plate 18) may be integrally molded.

In order to reduce the weight of the soundproof structure 10, at least one of the core body 12, the back plate 18 and the perforated plate 20 is a paper material such as corrugated board, a fiber aggregate such as thick cloth, or foam. It may be made of a resin material such as plastic and closed-cell urethane.

In order to reduce the weight of the soundproof structure 10, it is preferable that all of the core body 12, the back plate 18 and the perforated plate 20 are made of the above-mentioned materials. Further, from the viewpoints of easiness of molding and easiness of incineration, it is particularly preferable that all of the core body 12, the back plate 18 and the perforated plate 20 are made of a paper material. Furthermore, from the viewpoint of making it difficult for sound to leak between the cells 14, a material having no air permeability such as closed-cell urethane or a structure having a low air permeability such as corrugated board is preferable among the above materials. In addition to such a structure, it is also possible to use a structure in which the air permeability is lowered by providing a non-breathable coating layer or film on the surface of the above-mentioned material.

[Porous material]
The porous body 24 is superposed on the perforated plate 20 in the thickness direction, and forms the outermost layer in the soundproof structure 10 in the configuration of FIG. 1. In this case, the surface of the perforated plate 20 (the surface on the side opposite to the core body 12) is covered with the porous body 24 so that the perforated plate 20 having the through holes 22 formed therein cannot be visually recognized. You can As a result, it is possible to suppress deterioration of the aesthetics (design) and texture of the soundproof structure 10. In order to obtain such an effect, it is preferable that the surface of the porous body 24 has an area that can cover the entire surface of the perforated plate 20 on the viewing side (sound source side).

Further, the porous body 24 functions as a sound absorbing material in the soundproof structure 10, as described above. More specifically, the porous body 24 absorbs sound by the two mechanisms described above. That is, when the sound passes through the fine holes 26 of the porous body 24, the porous body 24 absorbs sound energy by converting sound energy into heat energy by friction between the inner wall surface of the fine hole 26 and air. .. In addition, the porous body 24 is vibrated as a string or a film body by the sound that has entered the inside, and thereby the sound energy is converted into mechanical energy to absorb the sound.

The porous body 24 is preferably made of a foam material such as urethane foam, a thin film porous body made of a resin material or metal, a wood aggregate, porous ceramics, or a fiber aggregate such as cloth and paper. From the viewpoint of design, the porous body 24 is preferably made of cloth. Examples of the cloth constituting the porous body 24 include woven cloth, knitted cloth, and non-woven cloth. In addition, it is preferable to use fibers having a fiber diameter of submicron order (order of 1 to 100 nm) as the fibers of the cloth forming the porous body 24, because they are thinner than conventional non-woven fabrics and have a higher sound absorbing effect. Examples of the non-woven fabric forming the porous body 24 include a non-woven fabric made of Thinsulate (trademark, manufactured by 3M Co., Ltd.), sound absorbing felt, and metal fiber (Poal (manufactured by Unix Co.)). Examples of the woven fabric constituting the porous body 24 include broad (plain woven fabric), sheeting (plain woven fabric), poplin (plain woven fabric), and non-combustible cloth (made by ISTFLON Corporation IST). it can.
When the porous body 24 is made of cloth, the porous body 24 may be made of one piece of cloth, or a plurality of cloths may be stacked to make up the porous body 24. In order to reduce the weight, size, and cost of the body 10, it is preferable to configure the porous body 24 with only one cloth.

Fibers constituting the porous body 24 include cellulose fibers (including cotton fibers, cotton fibers, and hemp fibers), silk fibers, animal fibers, feather fibers, mineral fibers, aramid fibers, glass fibers, nylon fibers, vinylon fibers. , Polyester fiber, polyethylene fiber, polypropylene fiber, polyolefin fiber, rayon fiber, low density polyethylene resin fiber, ethylene vinyl acetate resin fiber, synthetic rubber fiber, copolyamide resin fiber, copolyester resin fiber, etc. Examples thereof include fibers made of metal materials such as stainless steel fibers, fibers made of carbon materials, and fibers made of carbon-containing materials.

Materials other than the cloth constituting the porous body 24 include glass wool, rock wool, urethane foam, and gypsum board.

Further, when the porous body 24 made of a metal material (for example, a cloth sheet made of metal fibers) is used, the flame retardancy of the soundproof structure 10 can be improved. Such an effect is particularly effective when the core body 12, the back plate 18 and the perforated plate 20 are made of a combustible material such as paper. Incidentally, among the metal materials, copper, nickel, stainless steel, titanium and aluminum are preferable from the viewpoint of cost and availability. In particular, it is most preferable to use aluminum and an aluminum alloy because they are lightweight, easily form fine pores by etching, etc., and from the viewpoint of availability and cost.

Furthermore, with respect to the porous body 24 made of a metal material, ozone resistance can be improved and radio waves can be shielded. Furthermore, since the porous body 24 made of a metal material has conductivity and is hard to be charged, minute dust and dirt are not attracted to the film by static electricity, and the fine pores 26 of the porous body 24 are protected from dust and dirt. It is possible to prevent the sound absorbing performance from being deteriorated by clogging with dust and the like. Further, since the metallic material has a high reflectance to the radiant heat due to the far infrared rays, the porous body 24 made of the metallic material also functions as a heat insulating material for preventing heat transfer due to the radiant heat. At that time, since a large number of micropores 26 having a relatively small diameter are formed in the porous body 24, the porous body 24 functions as a reflection film against radiant heat.

Further, with respect to the porous body 24 made of a metal material, metal plating may be applied to the surface from the viewpoint of suppressing rust and the like. At this time, at least the inner wall surface of the fine holes 26 may be subjected to metal plating to adjust the average diameter of the fine holes 26 to be smaller. In addition, when performing metal plating, it is desirable to perform metal plating so that no knot points are formed between fibers.

The porous body 24 has a plurality of fine holes 26 as shown in FIG. Here, the fine holes 26 form a ventilation portion, and the sound emitted from the sound source enters the cell 14 through the ventilation portion. In the cloth forming the porous body 24, the fine pores 26 are spaces between fibers and are three-dimensionally arranged in a mesh shape. That is, in the cloth forming the porous body 24, the average diameter and the average aperture ratio of the micropores 26 are determined by the fiber diameter and the density. Here, the average diameter and the average aperture ratio of the fine holes 26 are not particularly limited and can be set arbitrarily.

From the viewpoint of absorbing relatively low frequency sound in a wide band, the flow resistance of the porous body 24 is preferably 300 Pa·s/m or more and 1500 Pa·s/m or less. By the way, the flow resistance of the porous body 24 is more preferably 350 Pa·s/m or more and 1200 Pa·s/m or less, and is 375 Pa·s/m or more and 1000 Pa·s/m or less. Particularly preferred.
The flow resistance of the porous body 24 is 4 cc/cm ² /s per unit area of the surface of the porous body 24 using a ventilation resistance measuring device (KES F-8 manufactured by Kato Tech Co., Ltd.). It can be set to and measured. This method is a method of measuring the ventilation resistance by a constant ventilation amount method, and a step of sandwiching the porous body 24 in the measurement part and releasing air at the above ventilation amount toward the atmosphere through the sample, and Similarly, it is composed of two steps of sucking the sample from the atmosphere through the sample to the apparatus side, and is a method of measuring the flow resistance by measuring the pressure at each step. When the flow resistance in the surface of the porous body 24 is not uniform, the average value of the flow resistance of each part of the surface may be adopted as the flow resistance of the porous body 24. For example, it is possible to measure three points in the cloth constituting the porous body 24 and use the average value thereof as the flow resistance.
Also, when a plurality of members having different flow resistances are used, such as pasting different kinds of cloths in different places, or when the flow resistances are different for each region, each member or region is different. The above measurement should be performed.
Regarding the flow resistance, the flow resistance may be measured using a system such as "Flow Resistance Measurement System AirReSys" manufactured by Nippon Acoustic Engineering. The method adopted by this system is the method specified in ISO 9053 (ISO 9053-1:2018 as of 2018), and as long as this method is followed, it is possible to measure with other devices.

Further, the surface density of the porous body 24 affects the sound absorbing performance. Specifically, the frequency (sound absorption peak frequency) that maximizes the sound absorption coefficient with respect to a predetermined flow resistance, the easiness of vibration in the porous body 24 having a relatively large flow resistance, and the sound absorption peak frequency. Affects sound absorption (ie maximum sound absorption). For example, the higher the surface density, the lower the sound absorption peak frequency and the less likely it is that vibration will occur. In consideration of such a situation, the surface density of the porous body 24 is preferably 20 g/m ² or more and 2000 g/m ² or less. This range is preferable for the purpose of absorbing a low frequency sound and optimizing a lightweight structure. As for the lower limit of the surface density of the porous body 24, the maximum sound absorption coefficient can exceed 99%, and more preferably 100 g/m ² if it is 70 g/m ² or more. On the other hand, the upper limit value of the surface density of the porous body 24 is preferably 400 g / ^{m 2,} and more preferably a 300 g / ^{m 2.}

The surface density can be obtained by measuring the size (area) of the surface of the porous body 24 and measuring the weight of the porous body 24 by a usual measuring method. Regarding the surface area of the porous body 24, the area in the form used for the soundproof structure is measured. More specifically, when the porous body 24 made of a material that stretches well is stretched and stuck, the area in the stretched state is measured. In this case, the measurement result is basically equal to the area of the perforated plate 20 adjacent to the porous body 24. After the area is measured, if the size is large, the porous body 24 is folded and the weight is measured in that state using a scale. Then, the surface density of the porous body 24 can be obtained by calculating (measured weight)/(measured area).
When the entire size of the porous body 24 cannot be measured by weighing due to its large size, and the porous body 24 cannot be folded, a part of the porous body 24 may be cut out for measurement. The area to be cut out at that time is not particularly limited, but the weight can be measured, for example, by cutting out in a square shape of 10 cm×10 cm.
Also, in the same way as the flow resistance measurement, when a plurality of members with different flow resistance are clearly used or the flow resistance is completely different in each area, such as pasting different types of cloth in different places. The above measurement may be performed for each member or region.

Further, the thickness of the porous body 24 is not particularly limited, but the thinner the porous body 24 is, the more preferable it is from the viewpoints of size reduction, weight reduction, air permeability and light transmission. For example, the thickness of the porous body 24 is preferably 50 mm or less, more preferably 25 mm or less, more preferably 20 mm or less, further preferably 10 mm or less, still more preferably 5 mm or less, still more preferably 2 mm or less, and 1 mm. Less than is most preferred. Further, since the porous body 24 is likely to be mechanically damaged if it is too thin, the thickness of the porous body 24 is preferably 0.1 μm or more, more preferably 1.0 μm or more, More preferably, it is 10 μm or more.

The planar shape and size (area) of the porous body 24 are not particularly limited, but may be set as appropriate according to the planar shape and size of the core body 12 and the perforated plate 20. Incidentally, in the state where the perforated plate 20 and the porous body 24 are stacked on the core body 12 in the thickness direction, the porous body 24 covers the entire opening surface of each of the plurality of cells 14 formed by the core body 12. It is preferable to have only the area. In this case, the porous body 24 can effectively absorb sound before the sound enters the cell 14.

Regarding the porous body 24 such as cloth, functions other than sound absorbing performance, for example, flame retardancy, designability, waterproofness, water repellency, oil repellency, antifouling property, abrasion resistance, weather resistance, and shape retention property. For the purpose of imparting the like, processing for modifying the property of flow resistance may be performed. The soundproof structure 10 using the porous body 24 that has been subjected to the above-mentioned processing is installed and used in a place where the soundproof structure has not been used in the past, and therefore its market value. And the usefulness is increased.

On the other hand, depending on the processing method, the air permeability and sound absorption of the porous body 24 may be reduced. In order to maintain the sound absorbing property of the porous body 24, it is necessary to select an appropriate processing method with respect to the characteristics imparted to the porous body 24 (the characteristics to be modified). However, as the cloth that constitutes the porous body 24, a cloth that has been processed to impart desired characteristics while maintaining sound absorption is rarely available on the market. As the cloth forming the porous body 24, there is a cloth on which a predetermined image is printed for improving the design, but the kind (cloth) of the cloth is limited, and the image is further requested when printing is requested. Since manuscript submission is required, processing cost and labor will increase.

For the above reasons, when processing the cloth constituting the porous body 24 in the present invention, among the mechanical properties on the surface of the cloth, those related to sound absorption (specifically, flow resistance, fiber strength, It is preferable to use a method capable of maintaining the aperture ratio, the knotting ratio, etc.). In other words, the porous body 24 may have a processed portion that has been processed to modify the properties (physical properties) of the porous body 24. Here, the flow resistance of the processed portion after processing is preferably 300 Pa·s/m or more and 1500 Pa·s/m or less.

A specific example will be explained. The flow resistance of the cloth before processing is 300 to 1500 Pa·s/m, and design is imparted to the cloth (for easy understanding, an image or a pattern is formed on the processed portion). Examples of the method of applying include dyeing with a dye, coloring with a paint, and transfer of a printed film. Among these, dye dyeing makes it difficult for the mechanical properties of the cloth surface related to sound absorption to change before and after processing. On the other hand, in paint coloring and film transfer, the mechanical properties of the cloth surface related to sound absorption tend to change before and after processing. Therefore, it is considered that dyeing is preferable as a processing method for providing an image or a pattern on the processed portion.

As another water-repellent treatment for imparting water repellency to a cloth having a flow resistance of 300 to 1500 Pa·s/m, a method of laminating a water-repellent coating layer on the cloth surface, and A method of immersing a cloth in a chemical solution to chemically bond the water-repellent component to the fibers of the cloth material can be mentioned. In the former method, the mechanical properties of the cloth surface related to sound absorption are likely to change before and after processing, but in the latter method, changes in the mechanical properties are suppressed. Therefore, as a method of imparting water repellency to the processed portion, a method of chemically bonding a water repellent component to the fibers of the cloth material is considered to be preferable.

Examples of the processing applied to the processed portion include dyeing processing and water repellent processing described above, and include, for example, printing processing, sublimation transfer processing, raised processing, antibacterial processing, water absorption processing, quick-drying processing, morphological stabilization processing, Wrinkle-proof processing, photocatalytic processing, ultraviolet ray cutting processing, dust-proof processing, cool feeling processing, negative ion processing, flameproof processing, pollen adhesion prevention processing, and pest repellent processing, at least one of these is applied to the processed part. It should have been done.

The ratio of the region belonging to the processed portion in the surface to the surface of the porous body 24 in the thickness direction (strictly speaking, the surface on the side opposite to the perforated plate 20) is preferably more than 5%. More preferably more than 30%, particularly preferably more than 70%. That is, the processed portion and the non-processed portion may be mixed in the porous body 24 as long as the flow resistance (air permeability) is the same between the processed portion and the non-processed portion.

[Clamp]
The retaining portion 28 retains the porous body 24 on the core body 12, the back plate 18 or the perforated plate 20 in order to maintain the contact state between the porous body 24 and the perforated plate 20. The retaining portion 28 is not particularly limited, but is, for example, one provided between the porous body 24 and the perforated plate 20 for retaining the porous body 24 on the perforated plate 20, or a porous body. The thing which penetrates both the body 24 and the perforated plate 20 is mentioned.

Examples of the retaining portion 28 provided between the porous body 24 and the perforated plate 20 include an adhesive layer made of an adhesive or an adhesive tape, a magnet, and a surface fastener. Of these, when the retaining portion 28 made of the adhesive layer is used, the porous body 24 and the perforated plate 20 can be integrated with each other to improve the structural rigidity. The adhesive forming the adhesive layer may be selected according to the material of the porous body 24, the material of the perforated plate 20, and the like. Examples of adhesives include epoxy adhesives (Araldite (registered trademark) (manufactured by Nichiban Co., Ltd.), cyanoacrylate adhesives (Aron Alpha (registered trademark) (manufactured by Toagosei Co., Ltd.), and acrylic adhesives. Adhesives and the like can be mentioned.

Examples of the retaining portion 28 that penetrates both the porous body 24 and the perforated plate 20 include a fastening pin such as a thumbtack, a stapler core, and a suture thread.

Then, in the soundproof structure 10 of the present invention, as described above, the range in which the porous body 24 is fastened to the perforated plate 20 by the fastening portion 28 with respect to the contact area of the porous body 24 with the perforated plate 20. The area ratio (hereinafter, referred to as “area ratio” for convenience) is 92% or less. As a result, in the soundproof structure 10 of the present invention, both structural rigidity and soundproof performance can be ensured, and more specifically, the maximum sound absorption coefficient is 0.8 or more. From the viewpoint of further improving the maximum sound absorption coefficient, the area ratio is more preferably 62% or less, and in this case, the maximum sound absorption coefficient is 0.9 or more. Furthermore, it is particularly preferable that the area ratio is 46% or less, in which case the maximum sound absorption coefficient reaches about 1.

Further, regarding the planar arrangement of the retaining portion 28 interposed between the porous body 24 and the perforated plate 20, the area of the retaining portion 28 can be reduced by patterning the retaining portion 28 as shown in FIGS. 6 to 8. Even if the size is small, the rigidity can be effectively maintained. More specifically, as shown in FIGS. 6 to 8, if the retaining portions 28 are arranged along the acting direction of the external force on the porous body 24, the area ratio can be reduced while maintaining the structural rigidity. Is possible.

Further, as shown in FIG. 8, it is more preferable that the retaining portions 28 are linearly arranged along the edge (outer periphery) of the contact portion of the porous body 24 with the perforated plate 20. With such a configuration, it is possible to secure the structural rigidity and use only the edge of the contact portion as a knot point. As a result, it is possible to further widen the area of the portion that vibrates (string vibration or film vibration) due to sound absorption in the contact portion.

6 to 8 are diagrams showing variations of the arrangement pattern of the fastening portions 28. Strictly explaining, each of FIGS. 6 to 8 shows a surface of the porous body 24 facing the perforated plate 20 when the retaining portion 28 is interposed between the porous body 24 and the perforated plate 20. 6 schematically shows the arrangement pattern of the fastening portions 28 in FIG. Here, the arrangement pattern shown in FIG. 6 is a pattern in which the retaining portions 28 form a pair of parallel lines. The arrangement pattern shown in FIG. 7 is a pattern in which the fastening portions 28 are arranged at four apexes and a center point in a rectangle. As described above, FIG. 8 shows a pattern in which the retaining portions 28 are linearly arranged along the edge of the contact portion of the porous body 24 with the perforated plate 20.
Incidentally, as for the arrangement pattern of the fastening portions 28, naturally, patterns other than those shown in FIGS. 6 to 8 can be considered, and if the area ratio is in the above range, one of those patterns is arbitrarily selected and adopted. May be.

The fastening portion 28 is not limited to one that fastens the porous body 24 to the perforated plate 20, and may be one that fastens the porous body 24 to the back plate 18 as shown in FIG. 24 may be fastened to the core body 12. FIG. 9 is a partial cross-sectional view of the soundproof structure 10z in which the porous body 24 is fastened to the back plate 18.

In the configuration shown in FIG. 9, the plane size of the porous body 24 is larger than the plane size of the perforated plate 20, and the portion where the porous body 24 protrudes outside the outer edge of the perforated plate 20 (hereinafter , The protruding portion). The end of the protruding portion of the porous body 24 wraps around to the back side of the back plate 18, and is fastened to the back plate 18 by an adhesive layer as a fastening portion 28, a thumbtack, a hook-and-loop fastener, etc., as shown in FIG. With such a configuration, since there is no portion of the porous body 24 that is directly fixed to the perforated plate 20, the area ratio is 0%.

<<About the soundproof panel of the present invention>>
Next, a soundproof panel of the present invention configured using the soundproof structure 10 described above will be described by taking the configuration of the soundproof panel B shown in FIG. 10 as an example. FIG. 10 is a perspective view showing the soundproof panel B.

As shown in FIG. 10, the soundproof panel B has a panel body Bx composed of the soundproof structure 10 and a frame body By surrounding the panel body, and has a sound absorbing performance (that is, a sound absorbing panel). Is. In the soundproof panel B shown in FIG. 10, a part of the soundproof structure is formed by the soundproof structure 10. However, the present invention is not limited to this, and the soundproof panel B is entirely formed by the soundproof structure 10. Good. Further, of the panel body Bx and the frame body By, only the frame body By may be configured as the soundproof structure 10.

The soundproof panel B is used for a soundproof member, a soundproof box, a soundproof enclosure structure, a soundproof room, and the like. As the soundproof member, for example, one used as a building material, one used for air conditioning equipment, one installed in an opening such as a window of a room, one installed on a ceiling, one installed for a floor, and a room Items installed in room openings such as doors or sliding doors, items installed inside toilets, items installed on balconies, items used for indoor tone adjustment, items used to construct simple soundproof rooms, pet sheds , Those installed in amusement facilities, those used for sound insulation at construction sites, those installed in the interior of moving bodies such as vehicles (for example, passenger compartments in automobiles, trains, airplanes, etc.), In addition, those installed in the tunnel can be mentioned.

The soundproof box is a box body constructed by arranging a plurality of panel materials including the soundproof panel B in a box shape, and is used, for example, for building a building and other structures, for transportation, and for logistics. be able to. The soundproof box using the soundproof panel B can prevent sound from leaking from the inside of the box to the outside or from entering from the outside to the inside of the box. The soundproof box is used, for example, as a pet house or as a housing of equipment that becomes a noise source.

The soundproof enclosure structure is configured by arranging a plurality of panel materials including the soundproof panel B as an outer peripheral wall (that is, a partition), and by arranging a sound source in the inner space thereof, a sound absorbing effect on noise is exhibited. To do. The soundproof enclosure structure is not limited to the soundproof panel B arranged in a ring shape so as to surround the sound source, and may be one or two partitions. Further, the soundproof enclosure structure may be used in a form attached to a chair, a desk or the like.
The soundproof room is a room configured by using a plurality of panel materials including the soundproof panel B for a room wall or a ceiling, and exhibits a sound absorbing effect against a voice of a person who is active indoors or noise generated outdoors. To do.
The above-mentioned sound source may be a device that emits sound or a human voice.

Hereinafter, the present invention will be described in more detail with reference to Examples. The materials, usage amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the following examples.

[Example 1]
A plurality of soundproof structures having the structure shown in FIG. 1 were produced by changing the area ratio. Specifically, a 230 μm thick porous body, a 1 mm thick perforated plate thickness, a 30 mm thick cell, and a 1 mm thick back plate were laminated in this order to produce a soundproof structure. In addition, a through hole having a hole diameter of 5 mm was formed on the perforated plate so that the aperture ratio was 20%. A cloth is used as the porous body, and the reference value of the flow resistance is 447 Pa·s/when the air flow rate is measured by the above-mentioned measurement method at 0.4 cc/cm ² /s. m, and the areal density is 83 g/m ² .
The area ratios of the produced soundproofing structures are 100%, 91%, 80%, 65%, 54%, 46%, 27%, 16% and 0%, respectively. In Example 1, the porous body was fastened to the perforated plate by the retaining portion composed of the adhesive layer, and the porous body was adhered to the perforated plate with respect to the contact area of the porous body with the perforated plate. The area ratio is defined as the area ratio of the range.

With respect to each soundproof structure, the porous body in the soundproof structure was arranged so as to face the sound source side, and the sound absorption coefficient was measured with the acoustic tube. As the acoustic tube measuring method, according to "JIS A 1405-2", a measurement system for normal incidence sound absorption coefficient using two microphones was prepared and evaluated. The internal diameter of the acoustic tube was 4 cm, and the system was designed to measure up to about 4000 Hz. In addition, WinZacMTX manufactured by Nippon Acoustic Engineering can be used for the same measurement.

Changes in the sound absorption coefficient measured for the produced soundproofing structure are shown in FIGS. 11A to 11C. 11A to 11C are diagrams showing the results of measuring the sound absorption coefficient for each area ratio, in which the horizontal axis represents frequency and the vertical axis represents sound absorption coefficient. Further, the maximum sound absorption coefficient and the sound absorption coefficient at 2000 Hz obtained in each area ratio are shown in FIG. FIG. 12 is a diagram showing a correspondence relationship between the area ratio and the sound absorption coefficient, in which the horizontal axis represents the area ratio and the vertical axis represents the sound absorption coefficient. The mathematical formula shown in FIG. 12 represents a regression formula (approximate formula) of the area ratio and the sound absorption coefficient of 46% or more.

As can be seen from FIGS. 11A to 11C and FIG. 12, when the area ratio is 92% or less, the maximum sound absorption coefficient is 0.8 or more. Further, as can be seen from FIG. 12, when the area ratio is decreased from 100%, the maximum sound absorption coefficient and the sound absorption coefficient at 2000 Hz increase in a substantially linear shape. Further, when the area ratio is 62% or less, the maximum sound absorption coefficient is 0.9 or more, and when the area ratio is 46%, the maximum sound absorption coefficient reaches about 1, and when the area ratio is 46% or less, the maximum sound absorption coefficient is maintained at 1. ..
The effects of the present invention are clear from the first embodiment described above.

10, 10x, 10y, 10z Soundproof structure 12 Core body 14 Cell 14a Opening 14b Partition wall 18 Back plate 20 Perforated plate 22 Through hole 24 Porous body 26 Fine hole 28 Fastening part B Soundproof panel Bx Panel body By Frame body

Claims (13)

A core body that constitutes a plurality of cells,
A back plate that covers the opening surface of each of the plurality of cells in the thickness direction of the core body;
A perforated plate that is arranged on the opposite side of the back plate through the core body in the thickness direction, and has a through hole formed therein;
A porous body that is in contact with the perforated plate in the thickness direction,
A fastening portion for fastening the porous body to a member other than the porous body,
The ratio of the area of the range in which the porous body is fastened to the perforated plate by the fastening portion to the contact area of the porous body with the perforated plate is 92% or less. Structure. The soundproof structure according to claim 1, wherein the ratio is 46% or less. The soundproof structure according to claim 1 or 2, wherein the planar arrangement of the fastening portions is a pattern-like arrangement. The soundproofing structure according to any one of claims 1 to 3, wherein the retaining portion is arranged along an edge of a contacting portion of the porous body with the perforated plate. The soundproof structure according to any one of claims 1 to 4, wherein the porous body is made of cloth. The soundproof structure according to any one of claims 1 to 5, wherein the flow resistance of the porous body is 300 Pa·s/m or more and 1500 Pa·s/m or less. The soundproof structure according to any one of claims 1 to 6, wherein an area density of the porous body is 20 g/m ² or more and 2000 g/m ² or less. The soundproof structure according to any one of claims 1 to 7, wherein the through hole has a hole diameter of more than 1 mm and 15 mm or less. The hole diameter of the end closer to the core body in the through hole and the hole diameter of the end further away from the core body in the through hole are different from each other. The soundproof structure described. The hole diameter of the through hole increases toward the end of the through hole farther from the core body,
The soundproofing structure according to claim 9, wherein an end of the through hole farther from the core body is directed to a side where a sound source is located. In a state where the porous body and the perforated plate are stacked on the core body in the thickness direction, the porous body has an opening surface of each of the plurality of cells on the side opposite to the back plate in the thickness direction. The soundproof structure according to any one of claims 1 to 10, which covers the soundproof structure. The porous body has a processed portion that has been processed to modify the properties of the porous body,
The soundproof structure according to any one of claims 1 to 11, wherein the flow resistance of the processed portion after processing is 300 Pa·s/m or more and 1500 Pa·s/m or less. A soundproof panel comprising the soundproof structure according to any one of claims 1 to 12.