JP6327932B2 - Sound absorber using Helmholtz resonance - Google Patents
Sound absorber using Helmholtz resonance Download PDFInfo
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- JP6327932B2 JP6327932B2 JP2014095851A JP2014095851A JP6327932B2 JP 6327932 B2 JP6327932 B2 JP 6327932B2 JP 2014095851 A JP2014095851 A JP 2014095851A JP 2014095851 A JP2014095851 A JP 2014095851A JP 6327932 B2 JP6327932 B2 JP 6327932B2
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- 239000006096 absorbing agent Substances 0.000 title claims description 24
- 238000010521 absorption reaction Methods 0.000 description 14
- 238000005422 blasting Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 238000005192 partition Methods 0.000 description 3
- 230000030279 gene silencing Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 210000002268 wool Anatomy 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000003584 silencer Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
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- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Description
本発明はヘルムホルツ共鳴を利用した吸音器に関するものであり、さらに詳細には、吸音器の構造を大きく変えることなく、また、吸音器の材料を変えることなく、ヘルムホルツ共鳴を低い周波数に設定することができるヘルムホルツ共鳴を利用した吸音器に関するものである。 The present invention relates to a sound absorber using Helmholtz resonance. More specifically, the Helmholtz resonance is set to a low frequency without greatly changing the structure of the sound absorber and without changing the material of the sound absorber. The present invention relates to a sound absorber that uses Helmholtz resonance.
山岳トンネルの延伸工事においては、坑口側から順に坑内での発破を繰り返しながら、延伸工事おこなわれる場合があるが、この発破の際に生じる発破音は広帯域の周波音を含んでおり、さらに、音圧レベルもきわめて高いことが知られている。このような物理的特性を有する発破音が外部に漏れ出すと、周辺環境への騒音の問題が生じるだけでなく、発破音に含まれている周波数が５０Ｈｚ以下の低周波音が周辺建物を振動させるという問題もあった。 In the extension work of a mountain tunnel, the extension work may be carried out while repeating the blasting in the tunnel in order from the mine entrance side, but the blasting sound generated during this blasting includes broadband frequency sound, It is known that the pressure level is also very high. When a blasting sound with such physical characteristics leaks to the outside, not only does it cause a problem of noise to the surrounding environment, but low frequency sound with a frequency of 50 Hz or less contained in the blasting sound vibrates the surrounding buildings. There was also a problem of making it happen.
このように、トンネル発破音のうち、とくに周辺建物を振動させる低周波数帯域の音（低周波音）を消音させるトンネル発破音消音方法が特願２０１１−２５６６０９号公報（特許文献１）によって提案されている。 As described above, Japanese Patent Application No. 2011-256609 (Patent Document 1) proposes a tunnel blasting sound silencing method that silences a low frequency band sound (low frequency sound) that vibrates surrounding buildings among tunnel blasting sounds. ing.
特許文献１によって提案されているトンネル発破音消音方法は、トンネルの坑口ないし坑内を所定の隔壁で閉塞して、それぞれ、経路長の異なる複数の管体をこの隔壁より切羽側に設置することによって、低周波音の消音を図るものであり、低周波音を消音させるために、その１／４波長の経路長を備えた管体を隔壁よりも切羽側に設置することを提案している。 In the tunnel blasting sound silencing method proposed by Patent Document 1, the tunnel well or inside the tunnel is closed with a predetermined partition wall, and a plurality of pipe bodies having different path lengths are respectively installed on the face side from this partition wall. In order to mute the low frequency sound, in order to mute the low frequency sound, it has been proposed to install a tubular body having a path length of ¼ wavelength on the face side of the partition wall.
また、特許第５３９８８８３号公報には、概略立方体の中空な箱形をなし、その１つの面に筒状部材を挿入可能な開口を備え、他の消音装置とは別個独立して形成される消音装置が開示されている。 Japanese Patent No. 5398883 has a substantially cubic hollow box shape, and has an opening into which a cylindrical member can be inserted on one surface, and is formed separately from other silencers. An apparatus is disclosed.
特許文献１に提案されるように、１／４波長の経路長を備えた管体を用いて、たとえば、１０Ｈｚの低周波音を低減する場合には、約８．５ｍの長さの管体を必要であり、特許文献１はトンネル内に約８．５ｍの長さの管体を収めるために、管体を途中で屈曲させることを提案している。 As proposed in Patent Document 1, when a low frequency sound of, for example, 10 Hz is reduced using a tube having a 1/4 wavelength path length, the tube has a length of about 8.5 m. Patent Document 1 proposes bending the tube halfway in order to accommodate the tube body having a length of about 8.5 m in the tunnel.
しかしながら、様々な長さを有し、途中で屈曲された複数の管体をトンネル内という限られた空間内に収容する場合には、トンネル内で、複数の長さが異なり、屈曲された複雑な形状の管体が交錯し、トンネル内において、重機の設置スペースや作業員の通路を確保することが困難になるという問題があった。 However, when a plurality of pipes that have various lengths and are bent in the middle are accommodated in a limited space in the tunnel, a plurality of lengths differ in the tunnel, and the bent complicated There was a problem that it was difficult to secure installation space for heavy machinery and a passage for workers in the tunnel because of the crossing of the tubular bodies of various shapes.
また、特許文献２に開示された消音装置は、概略立方体の中空な箱形をなし、その１つの面に筒状部材を挿入可能な開口を備え、他の消音装置とは別個独立して形成されているが、かかるヘルムホルツ共鳴器において、共鳴周波数を変更するためには、長さが大きく異なる筒状部材に取り換えるか、筒状部材を抜き取って、開口を塞ぐなどの大幅な設計変更が必要となる。さらに、箱形体を嵌合して、奥行きを変化させることによって、共鳴周波数を変化させることも可能であるが、共鳴周波数を低くするためには、箱形体の容積を大きくする必要があるため，結果的に、箱形体の容積が大きくなり，トンネル通路の確保が困難になるという問題があった。 Further, the silencer disclosed in Patent Document 2 has a substantially cubic hollow box shape, and has an opening into which a cylindrical member can be inserted on one surface, and is formed independently of other silencers. However, in such Helmholtz resonators, in order to change the resonance frequency, it is necessary to make a major design change such as replacing the cylindrical member with a greatly different length, or removing the cylindrical member to close the opening. It becomes. Furthermore, it is possible to change the resonance frequency by fitting the box shape and changing the depth, but in order to lower the resonance frequency, it is necessary to increase the volume of the box shape. As a result, there is a problem that the volume of the box-shaped body becomes large and it is difficult to secure the tunnel passage.
したがって、本発明は、従来のヘルムホルツ共鳴器のように、筒状部材の長さを変えたり、また箱形体の容積を大きくする必要もなく、簡単な構成変更で、共鳴周波数を低い周波数に変化させることができるヘルムホルツ共鳴を利用した吸音器を提供することを目的とするものである。 Therefore, according to the present invention, unlike the conventional Helmholtz resonator, it is not necessary to change the length of the cylindrical member or increase the volume of the box-shaped body, and the resonance frequency can be changed to a low frequency by a simple configuration change. It is an object of the present invention to provide a sound absorber that uses Helmholtz resonance.
ヘルムホルツ共鳴器の共鳴周波数Fresは、次式によって与えられる。 The resonance frequency Fres of the Helmholtz resonator is given by:
したがって、ヘルムホルツ共鳴器の共鳴周波数Fresを低くするためには、（１）箱状体の中空部分の容積を大きくするか、（２）筒状体の長さを長くするか（３）筒状体の断面積を小さくすることが必要である。 Therefore, in order to reduce the resonance frequency Fres of the Helmholtz resonator, (1) increase the volume of the hollow portion of the box-shaped body, or (2) increase the length of the cylindrical body. It is necessary to reduce the cross-sectional area of the body.
このうち、（１）と（２）は、ヘルムホルツ共鳴器のサイズが過大になってしまうため、特別の場合以外は採用することはできない。これに対して、（３）は筒状体の断面積を小さくすればいい。しかしながら、筒状体の断面積を小さくすると、共鳴周波数Fresを低くすることは可能になるものの、吸音量を最大化するのに必要な筒状体の抵抗値が非常に小さくなる。このため、筒状体の内壁と空気との摩擦の影響が大きくなり、抵抗部材をつけなくても、筒状体の抵抗値が理想の値を大幅に超えてしまい、共鳴はするものの、吸音率が低くなってしまうため、本発明の前記目的を達成することができなかった。 Among these, (1) and (2) cannot be adopted except in special cases because the size of the Helmholtz resonator becomes excessive. On the other hand, (3) should just make the cross-sectional area of a cylindrical body small. However, if the cross-sectional area of the cylindrical body is reduced, the resonance frequency Fres can be lowered, but the resistance value of the cylindrical body necessary for maximizing the sound absorption volume becomes very small. For this reason, the influence of the friction between the inner wall of the cylindrical body and the air becomes large, and the resistance value of the cylindrical body greatly exceeds the ideal value without a resistance member, and although there is resonance, sound absorption Since the rate is low, the object of the present invention cannot be achieved.
本発明者は、本発明の前記目的を達成し、かかる問題を解決するため、鋭意研究を重ねた結果、中空な筒状体の断面積を変化させず、吸音率を最大化させる抵抗値を大きいまま維持しつつ、中空な筒状体の開放端部の断面積のみを小さくすることによって、伝達率Ｇを下げ、ヘルムホルツ共鳴器の共鳴周波数Fresを低くし得ることを見出した。 The present inventor achieved the above object of the present invention and solved the problem by intensive research.As a result, the resistance value that maximizes the sound absorption coefficient without changing the cross-sectional area of the hollow cylindrical body is obtained. It has been found that the transmissivity G can be lowered and the resonant frequency Fres of the Helmholtz resonator can be lowered by reducing only the cross-sectional area of the open end of the hollow cylindrical body while keeping it large.
本発明はかかる知見に基づくものであって、本発明にかかるヘルムホルツ共鳴を利用した吸音器は、一面に複数の開口部が形成された中空な箱状体の表面に、中空な筒状体が、その断面が前記開口部を含むように箱状体の外側又は内側に設けられ、前記中空な筒状体の開放端部の断面積が前記中空な筒状体の断面積よりも小さいことを特徴とするものである。 The present invention is based on such knowledge, and the sound absorber using Helmholtz resonance according to the present invention has a hollow cylindrical body on the surface of a hollow box-shaped body having a plurality of openings formed on one surface. , the cross-section is provided on the outside or inside of the box-like body so as to include the opening, the cross-sectional area of the open end of said hollow tubular body is smaller than the cross-sectional area of the hollow cylindrical body It is a feature.
ここに、本明細書においては、中空な筒状体の断面が開口部を含むとは、中空な筒状体の断面が開口部よりも大きい場合のみならず、中空な筒状体の断面が開口部と同じである場合を包含している。 Here, in this specification, that the cross section of the hollow cylindrical body includes the opening is not only the case where the cross section of the hollow cylindrical body is larger than the opening, but also the cross section of the hollow cylindrical body. The same case as the opening is included.
本発明によれば、中空な筒状体の開放端部の断面積を小さくするのみで、吸音率を最大化する抵抗部材の抵抗値を全く変更することなく、吸音率を高く維持したまま、共鳴周波数Fresのみを低くすることが可能になる。 According to the present invention, only by reducing the cross-sectional area of the open end of the hollow cylindrical body, without changing the resistance value of the resistance member that maximizes the sound absorption rate, while maintaining the sound absorption rate high, Only the resonance frequency Fres can be lowered.
本発明の好ましい実施態様においては、ヘルムホルツ共鳴を利用した吸音器において、前記中空な筒状体が、前記開口部より大きな断面を有し、その断面が前記開口部を含み、前記箱状体の内部に設けられている。 In a preferred embodiment of the present invention, in the sound absorber using Helmholtz resonance, the hollow cylindrical body has a larger cross section than the opening, and the cross section includes the opening. It is provided inside.
本発明のさらに好ましい実施態様においては、ヘルムホルツ共鳴を利用した吸音器において、前記中空な箱状体の前記開口部が形成された面を構成する面部材の厚さが前記中空な箱状体の他の５面を構成している面部材の厚さよりも厚くなるように構成されている。 In a further preferred embodiment of the present invention, in the sound absorber using Helmholtz resonance, the thickness of the surface member constituting the surface in which the opening of the hollow box-shaped body is formed is that of the hollow box-shaped body. It is comprised so that it may become thicker than the thickness of the surface member which comprises the other 5 surfaces.
本発明の別の好ましい実施態様においては、ヘルムホルツ共鳴を利用した吸音器において、前記中空な筒状体が、前記開口部の周囲から前記箱状体の外部に延び、先端部に前記開口部よりも断面積が小さい開放端部が形成されている。 In another preferred embodiment of the present invention, in the sound absorber using Helmholtz resonance, the hollow cylindrical body extends from the periphery of the opening to the outside of the box-shaped body, and is at the tip from the opening. Also, an open end portion having a small cross-sectional area is formed.
本発明は、５０Ｈｚ以下の低周波数帯域の音の減衰にとくに効果的であり、１０Ｈｚ以下の低周波数帯域の音の減衰にも効果的であることが確認されている。 It has been confirmed that the present invention is particularly effective for attenuation of sound in a low frequency band of 50 Hz or less, and is effective for attenuation of sound in a low frequency band of 10 Hz or less.
本発明によれば、中空な筒状体の開放端部の断面積を小さくするのみで、吸音率を最大化する抵抗部材の抵抗値を全く変更することなく、吸音率を高く維持したまま、共鳴周波数Fresのみを低くすることが可能になる。 According to the present invention, only by reducing the cross-sectional area of the open end of the hollow cylindrical body, without changing the resistance value of the resistance member that maximizes the sound absorption rate, while maintaining the sound absorption rate high, Only the resonance frequency Fres can be lowered.
図１は、本発明の好ましい実施態様にかかるヘルムホルツ共鳴を利用した吸音器の略斜視図であり、図２は、図１のＡ−Ａ線に沿った略断面図である。 FIG. 1 is a schematic perspective view of a sound absorber using Helmholtz resonance according to a preferred embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line AA of FIG.
図１および図２に示されるように、本実施態様にかかる吸音器は、中空な箱状体１と、箱状体１の一面に形成された開口部２と、開口部２より大きな断面を有し、その断面が開口部２を含む中空な筒状体３を箱状体１の内部に備えている。
中空な筒状体３の外側に向いた箱状体１の一面に形成された開口部２は筒状体の開放端部２０である。
また筒状体３の開口部２側と対向する端部には抵抗部材２６を備えている。抵抗部材２６としては、グラスウウール、ウールなどからなる粗毛フェルト、アセテートやナイロンなどの化学繊維系のもの、ウレタン系のものや、連続気泡多孔質材などを挙げることができる。
As shown in FIGS. 1 and 2, the sound absorber according to this embodiment has a hollow box 1, an opening 2 formed on one surface of the box 1, and a larger cross section than the opening 2. The hollow cylindrical body 3 having a cross section including the opening 2 is provided inside the box-shaped body 1.
An opening 2 formed on one surface of the box-like body 1 facing the outside of the hollow tubular body 3 is an open end 20 of the tubular body.
Further, a resistance member 26 is provided at an end of the cylindrical body 3 facing the opening 2 side. Examples of the resistance member 26 include coarse wool felt made of glass wool, wool, etc., chemical fiber materials such as acetate and nylon, urethane materials, and open-cell porous materials.
図３は、中空な筒状体の断面積が１００ｃｍ２で、開口部２と対向する端部に抵抗部材２６が設けられ、箱状体１の開口部２を１００ｃｍ２とした比較サンプル、箱状体１の開口部２を３６ｃｍ２としたサンプル＃１、箱状体１の開口部２を１６ｃｍ２としたサンプル＃２および箱状体１の開口部２を４ｃｍ２としたサンプル＃３の共鳴周波数と吸音率の関係を計算によって求めたグラフである。 FIG. 3 shows a comparative sample in which a hollow cylindrical body has a cross-sectional area of 100 cm 2 , a resistance member 26 is provided at an end facing the opening 2 , and the opening 2 of the box-like body 1 is 100 cm 2 . sample # 1 the opening 2 was 36cm 2 of shaped body 1, an opening 2 of the box-shaped body 1 was 16cm 2 sample # 2 and the box-like body 1 of sample # 3 which opening 2 is set to 4 cm 2 It is the graph which calculated | required the relationship between a resonant frequency and a sound absorption coefficient by calculation.
図３に示されるように、吸音率が最大の１．０になる共鳴周波数は、比較サンプルの場合に比較して、本発明かかるサンプル＃１ないし＃３の場合は低くなり、箱状体１の開口部２の断面積が小さくなるほど、吸音率が最大の１．０になる共鳴周波数が低くなり、箱状体１の開口部２を４ｃｍ２としたサンプル＃３の共鳴周波数は、比較サンプルの共鳴周波数の約１／２であることがわかる。 As shown in FIG. 3, the resonance frequency at which the sound absorption coefficient reaches a maximum of 1.0 is lower in the samples # 1 to # 3 according to the present invention than in the comparative sample. The smaller the cross-sectional area of the opening 2 is, the lower the resonance frequency at which the sound absorption coefficient becomes 1.0, and the resonance frequency of the sample # 3 in which the opening 2 of the box-like body 1 is 4 cm 2 is a comparative sample. It can be seen that the resonance frequency is about ½.
図４は、本発明の別の好ましい実施態様にかかるヘルムホルツ共鳴を利用した吸音器の略斜視図であり、図５は、図４のＢ−Ｂ線に沿った略断面図である。 FIG. 4 is a schematic perspective view of a sound absorber using Helmholtz resonance according to another preferred embodiment of the present invention, and FIG. 5 is a schematic cross-sectional view taken along line BB of FIG.
図４および図５に示されるように、本実施態様にかかる吸音器は、中空な箱状体１１と、箱状体１の一面に形成された開口部１２と、開口部１２の周囲から箱状体１１の外部に延び、先端部１５に開口部１２よりも断面積が小さい開放端部１６が形成された中空な筒状体１３を備えている。 As shown in FIGS. 4 and 5, the sound absorber according to this embodiment includes a hollow box 11, an opening 12 formed on one surface of the box 1, and a box from the periphery of the opening 12. A hollow cylindrical body 13 is provided which extends to the outside of the cylindrical body 11 and has an open end portion 16 having a smaller cross-sectional area than the opening portion 12 at the distal end portion 15.
図６は、本発明のさらに好ましい実施態様にかかるヘルムホルツ共鳴を利用した吸音器の略斜視図であり、図７は、図６のＣ−Ｃ線に沿った略断面図である。 FIG. 6 is a schematic perspective view of a sound absorber using Helmholtz resonance according to a further preferred embodiment of the present invention, and FIG. 7 is a schematic cross-sectional view taken along the line CC of FIG.
図６および図７に示されるように、本実施態様にかかる吸音器は、図１および図２に示された吸音器と同様に、中空な箱状体２１と、箱状体２１の一面に形成された開口部２２と、開口部２２より大きな断面を有し、その断面が開口部２２を含む中空な筒状体２３を箱状体１の内部に備えている。
中空な筒状体２３の外側に向いた箱状体２１の一面に形成された開口部２２は筒状体の開放端部２０である。
また、筒状体２３の開口部２２と対向する端部には抵抗材
２６を備えている。本実施態様においては、開口部２２が形成された箱状体２１の面を構成する面部材２５の厚さが、箱状体２１の他の五面を構成する面部材の厚さより大きく設定されている。
As shown in FIGS. 6 and 7, the sound absorber according to this embodiment is similar to the sound absorber shown in FIGS. 1 and 2, and has a hollow box 21 and one surface of the box 21. The formed opening 22 and a hollow cylindrical body 23 having a cross section larger than the opening 22 and including the opening 22 are provided inside the box-shaped body 1.
An opening 22 formed on one surface of the box-shaped body 21 facing the outside of the hollow cylindrical body 23 is an open end 20 of the cylindrical body.
Further, a resistance member 26 is provided at an end portion of the cylindrical body 23 facing the opening 22. In the present embodiment, the thickness of the surface member 25 constituting the surface of the box-shaped body 21 in which the opening 22 is formed is set to be larger than the thickness of the surface members constituting the other five surfaces of the box-shaped body 21. ing.
図８は、中空な筒状体の断面積が１００ｃｍ２で、開口部２２が形成された箱状体２１の面を構成する面部材２５の厚さを１ｍｍとした比較サンプル＃２、開口部２２が形成された箱状体２１の面を構成する面部材２５の厚さを８０ｍｍとしたサンプル＃１１、開口部２２が形成された箱状体２１の面を構成する面部材２５の厚さを６０ｍｍとしたサンプル＃１２、開口部２２が形成された箱状体２１の面を構成する面部材２５の厚さを４０ｍｍとしたサンプル＃１３、開口部２２が形成された箱状体３１の面を構成する面部材２５の厚さが２０ｍｍとしたサンプル＃１４および開口部２２が形成された箱状体２１の面を構成する面部材２５の厚さが１ｍｍとしたサンプル＃１５の共鳴周波数と吸音率の関係を計算によって求めたグラフである。 FIG. 8 shows comparative sample # 2 in which the cross-sectional area of the hollow cylindrical body is 100 cm 2 and the thickness of the surface member 25 constituting the surface of the box-shaped body 21 in which the opening 22 is formed is 1 mm, the opening Sample # 11 in which the thickness of the surface member 25 constituting the surface of the box-like body 21 on which the 22 is formed is 80 mm, the thickness of the surface member 25 constituting the surface of the box-like body 21 on which the opening 22 is formed Of sample # 12 having a thickness of 60 mm, sample # 13 having a thickness of the surface member 25 constituting the surface of the box-shaped body 21 in which the opening 22 is formed, and sample of the box-shaped body 31 in which the opening 22 is formed. Resonance frequency of sample # 14 in which the thickness of the surface member 25 constituting the surface is 20 mm and sample # 15 in which the thickness of the surface member 25 constituting the surface of the box-shaped body 21 in which the opening 22 is formed is 1 mm Is a graph obtained by calculation The
図８に示されるように、吸音率が最大の１．０になる共鳴周波数は、比較サンプル＃２の場合に比較して、本発明かかるサンプル＃１１ないし＃１５の場合は低く、開口部２２が形成された箱状体２１の面を構成する面部材の厚さが厚いほど、吸音率が最大の１．０になる共鳴周波数が低くなることが判明した。 As shown in FIG. 8, the resonance frequency at which the sound absorption coefficient reaches a maximum of 1.0 is lower in the samples # 11 to # 15 according to the present invention than in the comparative sample # 2, and the opening 22 It has been found that as the thickness of the surface member constituting the surface of the box-shaped body 21 formed with is increased, the resonance frequency at which the sound absorption coefficient reaches 1.0 becomes lower.
本発明は、以上の実施態様に限定されることなく、特許請求の範囲に記載された発明の範囲内で種々の変更が可能であり、それらも本発明の範囲内に包含されるものであることはいうまでもない。 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.
１ 中空な箱状体
２ 開口部
３ 中空な筒状体
１１ 中空な箱状体
１２ 開口部
１３ 中空な筒状体
１５ 筒状体の先端部
１６ 筒状体の開放端部
２０ 開放端部
２１ 中空な箱状体
２２ 開口部
２３ 中空な筒状体
２５ 面部材
２６ 抵抗部材
DESCRIPTION OF SYMBOLS 1 Hollow box-shaped body 2 Opening part 3 Hollow cylindrical body 11 Hollow box-shaped body 12 Opening part 13 Hollow cylindrical body 15 End part 16 of a cylindrical body Open end part of a cylindrical body
20 Open end portion 21 Hollow box-shaped body 22 Opening portion 23 Hollow cylindrical body 25 Surface member 26 Resistance member
Claims (4)
口部を含み、前記箱状体の内部に設けられていることを特徴とする請求項１
記載のヘルムホルツ共鳴を利用した吸音器。 The hollow cylindrical body has a larger cross section than the opening, and the cross section includes the opening and is provided inside the box-shaped body.
A sound absorber using the described Helmholtz resonance.
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| JP2014095851A JP6327932B2 (en) | 2014-05-07 | 2014-05-07 | Sound absorber using Helmholtz resonance |
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| Application Number | Priority Date | Filing Date | Title |
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| JP2014095851A JP6327932B2 (en) | 2014-05-07 | 2014-05-07 | Sound absorber using Helmholtz resonance |
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| JP6327932B2 true JP6327932B2 (en) | 2018-05-23 |
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| JP7070700B2 (en) * | 2018-11-05 | 2022-05-18 | ヤマハ株式会社 | Sound absorbing member, sound absorbing unit and sound absorbing structure |
| CN111105774A (en) * | 2019-10-29 | 2020-05-05 | 同济大学 | Helmholtz resonator and low-frequency broadband sound absorption and noise reduction structure based on same |
| CN111739503B (en) * | 2020-06-01 | 2023-07-21 | 南京航空航天大学 | Petal type inner inserting tube type Helmholtz resonance sound absorption structure |
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| JP6240446B2 (en) * | 2012-09-13 | 2017-11-29 | 大成建設株式会社 | Box Helmholtz Resonator Assembly and Tunnel Blasting Reduction Method |
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