JP4027068B2 - Sound absorbing material - Google Patents
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- JP4027068B2 JP4027068B2 JP2001313646A JP2001313646A JP4027068B2 JP 4027068 B2 JP4027068 B2 JP 4027068B2 JP 2001313646 A JP2001313646 A JP 2001313646A JP 2001313646 A JP2001313646 A JP 2001313646A JP 4027068 B2 JP4027068 B2 JP 4027068B2
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【０００１】
【発明の属する技術分野】
本発明は、音源の周囲に取り付けられ、この音源から発生する空気伝搬音、固体伝搬音、振動等を低減する吸音制振材に関する。
【０００２】
【従来の技術】
我々の周囲には例えば恒常的に交通車両や船舶等の乗物から発生する音や振動あるいは工場の機械類から発生する音や振動等様々な音や振動が発生しており、時にはこれらの音や振動が日常生活に支障を来す場合も少なくない。
【０００３】
従来から恒常的に発生する音や振動を低減するような方法が種々なされている。例えば、周波数帯域が５００Ｈｚを超えるような騒音に対してはグラスウールやロックウール等の多孔質吸音材を使用すると効果的な吸音が得られることが知られている。また、５００Ｈｚ以下の騒音に対しては多孔質吸音材の厚さを厚くしたり、さらに低周波数帯域に対しては吸音材の背後に空気層を設けるなどの試みがなされている。
【０００４】
あるいは、特開平８−１５２８９０号に開示されているように、通気度が５〜１００倍異なる高密度と低密度の繊維集合体を少なくとも２層以上積層した吸音構造体も提案されている。この発明は、空気の粘性抵抗を利用し、音波のエネルギーを熱エネルギーに変換して吸音する多孔質吸音構造体に、さらに密度が異なる繊維集合体を積層することで、高密度部分が付加質量、低密度部分がバネの役割を担う、いわゆる動吸振機を構成させて特に低周波数帯域の吸音率を向上させたものである。
【０００５】
【発明が解決しようとする課題】
ところで、上記のような従来の技術には、次のような解決すべき課題があった。
即ち、周波数帯域でも例えば５００Ｈｚ以下の周波数帯域に対してはグラスウールやロックウール等の多孔質吸音材の厚さを厚くしたり、吸音材の背後に空気層を設けるなどの試みがなされているが、十分な吸音効果を得ようとすると重量が重くなることやスペースを広くとらなければならない等の問題が生じていた。
【０００６】
また、特開平８−１５２８９０号に開示されているような技術では、特に１００Ｈｚ以下のいわゆる低周波帯域においては十分な吸音効果が得られていないのが現状である。さらに、低周波帯域の音や振動は空気伝搬音だけではなく、建物や窓のがたつきなども発生させるため、固体伝搬音及び振動を防止する対策を同時に行う必要があり、従来の吸音材ではその対策が困難であった。
【０００７】
本発明は音源の周囲の建物の壁面や天井あるいは高速道路の防音壁等に取り付けられ、交通車両、船舶、工場等の各種機械類のような外部から発生する空気伝搬音、固体伝搬音、振動の低減に効果的な吸音制振材を提供するものである。
【０００８】
【課題を解決するための手段】
本発明は以上の点を解決するため次の構成を採用する。
〈構成１〉
内部に連続気泡を有する粘弾性体からなる発泡体であって、前記粘弾性発泡体は音源側に近づくほど発泡密度が増加しもしくは減少するように発泡密度分布が調整されていることを特徴とする吸音制振材。
【０００９】
〈構成２〉
前記粘弾性発泡体は、それぞれ発泡密度が異なる複数の粘弾性発泡体を、音源側に近づくほど発泡密度が大きいものもしくは小さいものが配置されるように積層されたものであることを特徴とする構成１に記載の吸音制振材。
【００１０】
〈構成３〉
前記粘弾性発泡体の発泡密度は音源側で高密度としたことを特徴とする構成１または構成２に記載の吸音制振材。
【００１１】
〈構成４〉
前記粘弾性発泡体の発泡密度は音源側で低密度としたことを特徴とする構成１または構成２に記載の吸音制振材。
【００１２】
〈構成５〉
前記粘弾性発泡体の音源側に粘弾性体からなる制振シートを積層したことを特徴とする構成１から構成４までのいずれかの構成に記載の吸音制振材。
【００１３】
〈構成６〉
前記粘弾性発泡体の音源側に粘弾性体からなる独立気泡発泡体を積層したことを特徴とする構成１から構成４までのいずれかの構成に記載の吸音制振材。
【００１４】
〈構成７〉
前記粘弾性発泡体の音源側に金属薄膜層を積層したことを特徴とする構成１から構成４までのいずれかの構成に記載の吸音制振材。
【００１５】
〈構成８〉
前記粘弾性発泡体の剛壁側に粘弾性体からなる制振シートを積層したことを特徴とする構成１から構成８までのいずれかの構成に記載の吸音制振材。
【００１６】
【発明の実施の形態】
以下、本発明の実施の形態を具体例を用いて説明する。
【００１７】
図１は本発明における吸音制振材の一実施の形態を表した断面図である。
図１において、吸音制振材１は内部に連続気泡を有する複数のシート状の粘弾性発泡体２が積層されており、これら複数の粘弾性発泡体はそれぞれ発泡密度が２ａ、２ｂ、２ｃ、２ｄで異なっている。そして、積層された状態で、一方の面から他方の面に向かって、発泡密度が次第に増加もしくは減少するように、発泡密度を厚さ方向に傾斜的に異ならせている。即ち、、粘弾性発泡体は音源側に近づくほど発泡密度が増加しもしくは減少するように発泡密度分布が調整されている。また、音源側及び建物の壁面等のいわゆる剛壁５側には粘弾性体からなる制振シート３及び４を積層している。
【００１８】
本実施の形態において、粘弾性体からなる連続気泡発泡体を用いる理由は、音波が粘弾性発泡体に入射した場合、気泡部分の空気が振動し、この空気の粘性抵抗によって音波のエネルギーが熱エネルギーに変換されて吸音が行われるとともに、粘弾性体も振動し、やはり粘弾性体の粘性抵抗により音波のエネルギーが熱エネルギーに変換されるためにより効果的に吸音が行われるからである。
【００１９】
なお、本発明の粘弾性体からなる連続気泡発泡体は複数の発泡体を積層したものではなく、内部の発泡密度を傾斜的に異ならせた１枚の連続気泡発泡体から構成しても差し支えない。
【００２０】
また、本発明の吸音制振材は粘弾性体からなる連続気泡発泡体だけで構成してもよいが、本実施の形態のように音源側に粘弾性体からなる充実体の制振シートを積層すると、低周波の吸音に効果があるばかりではなく、建物等を伝搬してくる固体伝搬音及び振動も低減でき、加えて剛壁側にやはり粘弾性体からなる充実体の制振シートを積層すると固体伝搬音及び振動の低減をさらに効果的に行うことができる。
【００２１】
ところで、図１の実施の形態では音源側に粘弾性体からなる制振シートを積層して吸音制振材を構成したが、粘弾性体からなる独立気泡発泡体を積層してもよく、また薄膜層、例えばアルミニウム等の金属薄膜層を積層しても同様の効果を得ることができる。
【００２２】
これは、粘弾性体からなる制振シート、独立気泡発泡体、薄膜層等の部分は付加質量、即ち錘の役割、粘弾性体からなる連続気泡発泡体部分はバネ、いわゆる空気バネの役割として作用し、粘弾性体からなる制振シート、独立気泡発泡体、薄膜層等の部分は膜振動によって吸音が行われる。特に粘弾性体を用いた場合は制振性を有しているために、音波のエネルギーが熱エネルギーに変換されて吸音が行われるとともにさらに振動を低減する目的のために効果的である。
【００２３】
なお、音源側に積層する粘弾性体からなる制振シート、独立気泡発泡体、薄膜層等は目的とする吸音の程度により最も効果の高いものを選択すればよい。
【００２４】
次に、本発明による吸音機構の原理を説明する。
図２は前述した本発明の吸音機構を模式的に説明した図である。即ち図２において示すように、本発明の吸音機構は空気の粘性抵抗による吸音機構（ａ）と弾性効果と粘性抵抗を組み合わせた粘弾性体の吸音機構（ｂ）、それに錘と弾性効果を組み合わせた動吸振機による吸音機構（ｃ）とが加わった作用により実現されるものである。このような吸音機構は特に例えば１００Ｈｚ以下のような低周波吸音に対してより効果的である。
【００２５】
ここで、粘弾性体からなる連続気泡発泡体の発泡密度を音源側で高く、剛壁側で低くするように傾斜的に異ならせた場合、高密度部分は前記した付加質量の役割を果たし、低密度部分はバネの役割を果たすことで吸音が行われることになる。
【００２６】
一方、発泡密度を音源側で低く、剛壁側で高くするように傾斜的に異ならせた場合は連続気泡発泡体表面での音波の反射を低減し、より吸音率を向上させることができ、特に低周波の吸音効果に優れている。
【００２７】
【実施例】
次に本発明の実施例を説明する。以下に説明する本発明の実施例において、連続気泡発泡体はウレタン−アスファルトからなる基材を化学発泡させることにより得たものを用いた。
【００２８】
〈実施例１〉
厚さが２５ｍｍで音源側からの発泡密度がそれぞれ２５．２、７３．５、１４９、４２０ｋｇ／ｍ３の４枚の連続気泡発泡体を積層した吸音制振材。
【００２９】
〈実施例２〉
厚さが２５ｍｍで音源側からの発泡密度がそれぞれ４２０、１４９、７３．５、２５．２ｋｇ／ｍ３の４枚の連続気泡発泡体を積層した吸音制振材。
【００３０】
〈実施例３〉
実施例１において、音源側に厚さ０．０５ｍｍの粘弾性充実体からなる制振シートを積層した吸音制振材。
【００３１】
〈実施例４〉
実施例１において、音源側に厚さ３ｍｍの粘弾性体からなる独立気泡発泡体を積層した吸音制振材。
【００３２】
〈実施例５〉
実施例１において、音源側に厚さ０．０２ｍｍのアルミニウムの薄膜を積層した吸音制振材。
【００３３】
〈実施例６〉
実施例３において、剛壁側に厚さ２ｍｍの粘弾性充実体からなる制振シートを積層した吸音制振材。
【００３４】
〈実施例７〉
実施例４において、剛壁側に厚さ２ｍｍの粘弾性充実体からなる制振シートを積層した吸音制振材。
【００３５】
〈実施例８〉
実施例５において、剛壁側に厚さ２ｍｍの粘弾性充実体からなる制振シートを積層した吸音制振材。
【００３６】
〈比較例１〉
厚さが２５ｍｍで音源側からの発泡密度がそれぞれ２０、２４、３２、４０ｋｇ／ｍ３の４枚のグラスウールを積層した吸音材。
【００３７】
〈比較例２〉
厚さが２５ｍｍで音源側からの発泡密度がそれぞれ４０、３２、２４、２０ｋｇ／ｍ３の４枚のグラスウールを積層した吸音材。
【００３８】
上記の１〜８までの実施例及び比較例１、２につき、それぞれ吸音特性の指標となる吸音率と制振性の指標となる損失係数を測定した。
ここで、吸音率の測定は、JIS A 1405「音響−インピーダンス管による吸音率及びインピーダンスの測定−定在波比法」に従い、垂直入射吸音率を測定した。また、損失係数の測定は、JIS G 0602「制振鋼板の振動減衰特性試験方法」に準拠し、試験片の保持は中央支持方式、試験片の加振は電磁加振器、損失係数算出方法は半値幅法により行った。なお、吸音率はオンテックＲ＆Ｄ社製音響管式吸音特性測定システム、損失係数はリオン製の測定器を用いて行った。
【００３９】
図３は本発明の実施例における各周波数毎の吸音率、図４は各周波数毎の損失係数の値をそれぞれ比較例ととも示したものである。
【００４０】
図３及び図４から、本発明の実施例では吸音率においては特に３００〜４００Ｈｚ以下の低周波数に対して効果が顕著であり、１００Ｈｚの低周波数においても比較例に比べて充分吸音効果が高いことがわかる。
【００４１】
また、固体伝搬音や振動の低減の指標となる損失係数においては比較例に比べてすべての周波数において勝っており、１００Ｈｚ以下の低い周波数においても優れた効果を奏していることが明らかである。
【００４２】
【発明の効果】
上記したように本発明の吸音制振材によれば、粘弾性体からなる連続気泡発泡体を厚さ方向に発泡密度が傾斜的に異ならせ、さらに音源側に粘弾性体からなる制振シートや粘弾性体からなる独立気泡発泡体あるいは金属薄膜層を積層したり、剛壁側に粘弾性体からなる制振シートを積層したので、特に３００〜４００Ｈｚ以下の低周波の吸音に効果があり、また粘弾性体からなるため制振性も併せ持っているためすべての周波数において固体伝搬音や振動の低減に効果的な吸音制振材を提供できる。
【図面の簡単な説明】
【図１】本発明における吸音制振材の一実施の形態を表した断面図である。
【図２】本発明の吸音機構を模式的に説明した図である。
【図３】本発明の実施例における各周波数毎の吸音率の値を示した図である。
【図４】本発明の実施例における各周波数毎の損失係数の値を示した図である。
【符号の説明】
１ 吸音制振材
２ 連続気泡発泡体
３ 制振シート
４ 制振シート
５ 剛壁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sound absorbing material that is attached around a sound source and reduces air-borne sound, solid-borne sound, vibration, and the like generated from the sound source.
[0002]
[Prior art]
Various sounds and vibrations are generated around us, such as sounds and vibrations that are constantly generated from vehicles such as traffic vehicles and ships, or sounds and vibrations that are generated from factory machinery. In many cases, vibrations interfere with daily life.
[0003]
Conventionally, various methods for reducing sound and vibration that are constantly generated have been used. For example, it is known that effective noise absorption can be obtained when a porous sound absorbing material such as glass wool or rock wool is used for noise whose frequency band exceeds 500 Hz. Further, attempts have been made to increase the thickness of the porous sound absorbing material for noise of 500 Hz or less, and to provide an air layer behind the sound absorbing material for a low frequency band.
[0004]
Alternatively, as disclosed in JP-A-8-152890, a sound-absorbing structure in which at least two layers of high-density and low-density fiber assemblies having different air permeability of 5 to 100 times are laminated has been proposed. This invention uses the viscous resistance of air to convert sound wave energy into thermal energy to absorb sound, and then laminates fiber assemblies with different densities to add additional mass to the high density part. A so-called dynamic vibration absorber in which the low density portion plays the role of a spring is configured to improve the sound absorption coefficient particularly in the low frequency band.
[0005]
[Problems to be solved by the invention]
By the way, the conventional techniques as described above have the following problems to be solved.
That is, even in the frequency band of 500 Hz or less, for example, attempts have been made to increase the thickness of a porous sound absorbing material such as glass wool or rock wool, or to provide an air layer behind the sound absorbing material. In order to obtain a sufficient sound absorbing effect, there have been problems such as an increase in weight and a large space.
[0006]
Also, with the technique disclosed in Japanese Patent Laid-Open No. 8-152890, a sufficient sound absorption effect is not obtained particularly in a so-called low frequency band of 100 Hz or less. Furthermore, since low-frequency band sounds and vibrations generate not only air-propagating sounds, but also rattling of buildings and windows, it is necessary to take measures to prevent solid-propagating sounds and vibrations at the same time. Then, the countermeasure was difficult.
[0007]
The present invention is attached to a wall or ceiling of a building around a sound source or a soundproof wall of an expressway, and generates air-borne sound, solid-borne sound, vibration generated from outside such as various vehicles such as traffic vehicles, ships, factories, etc. The present invention provides a sound absorbing material that is effective in reducing the noise.
[0008]
[Means for Solving the Problems]
The present invention adopts the following configuration in order to solve the above points.
<Configuration 1>
A foam comprising a viscoelastic body having open cells therein, wherein the viscoelastic foam has a foam density distribution adjusted such that the foam density increases or decreases toward the sound source side. Sound damping material
[0009]
<
The viscoelastic foam is a laminate of a plurality of viscoelastic foams each having a different foaming density so that a foaming density that is larger or smaller is arranged closer to the sound source side. The sound-absorbing material according to Configuration 1.
[0010]
<
3. The sound absorbing material according to Configuration 1 or
[0011]
<
The sound-absorbing material according to Configuration 1 or
[0012]
<
5. The sound absorbing material according to any one of Configurations 1 to 4, wherein a damping sheet made of a viscoelastic material is laminated on a sound source side of the viscoelastic foam.
[0013]
<Configuration 6>
5. The sound absorbing material according to any one of configurations 1 to 4, wherein a closed cell foam made of a viscoelastic material is laminated on a sound source side of the viscoelastic foam.
[0014]
<Configuration 7>
5. The sound absorbing material according to any one of Configurations 1 to 4, wherein a metal thin film layer is laminated on a sound source side of the viscoelastic foam.
[0015]
<Configuration 8>
9. The sound absorbing material according to any one of Configurations 1 to 8, wherein a damping sheet made of a viscoelastic material is laminated on a rigid wall side of the viscoelastic foam.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described using specific examples.
[0017]
FIG. 1 is a cross-sectional view showing an embodiment of a sound absorbing material in the present invention.
In FIG. 1, the sound-absorbing material 1 is laminated with a plurality of sheet-like viscoelastic foams 2 having open cells therein, and these viscoelastic foams have foam densities of 2a, 2b, 2c, 2d is different. Then, in the stacked state, the foam density is inclined and varied in the thickness direction so that the foam density gradually increases or decreases from one surface to the other surface. That is, the foam density distribution of the viscoelastic foam is adjusted so that the foam density increases or decreases as it approaches the sound source side. Damping
[0018]
In this embodiment, the reason for using an open cell foam made of a viscoelastic body is that when sound waves are incident on the viscoelastic foam, the air in the bubble portion vibrates and the energy of the sound waves is heated by the viscous resistance of the air. This is because the sound is absorbed by being converted into energy, and the viscoelastic body also vibrates, and the sound wave energy is converted into thermal energy by the viscous resistance of the viscoelastic body, so that the sound absorption is more effectively performed.
[0019]
The open cell foam made of the viscoelastic material of the present invention is not formed by laminating a plurality of foams, and may be composed of a single open cell foam having a different internal foam density. Absent.
[0020]
Further, the sound-absorbing material of the present invention may be composed only of an open-cell foam made of a viscoelastic material, but a solid vibration-damping sheet made of a viscoelastic material on the sound source side as in this embodiment. Laminating not only has an effect on low-frequency sound absorption, but can also reduce solid-borne sound and vibration propagating through buildings, etc. In addition, a solid damping sheet made of viscoelastic material is also provided on the rigid wall side. When laminated, the solid propagation sound and vibration can be reduced more effectively.
[0021]
By the way, in the embodiment of FIG. 1, the sound absorbing material is configured by laminating a damping sheet made of a viscoelastic body on the sound source side, but a closed cell foam made of a viscoelastic body may be laminated, The same effect can be obtained by laminating a thin film layer, for example, a metal thin film layer such as aluminum.
[0022]
This is because the vibration damping sheet made of viscoelastic material, closed cell foam, thin film layer, etc. has an additional mass, that is, the role of weight, and the open cell foam made of viscoelastic material acts as a spring, so-called air spring. The parts such as the vibration damping sheet, the closed cell foam, and the thin film layer made of viscoelastic material are absorbed by the membrane vibration. In particular, when a viscoelastic body is used, since it has vibration damping properties, it is effective for the purpose of further reducing vibration while the sound wave energy is converted into heat energy to absorb sound.
[0023]
In addition, what is necessary is just to select the damping sheet, the closed-cell foam, a thin film layer, etc. which consist of the viscoelastic body laminated | stacked on the sound source side, and the most effective thing according to the target sound absorption degree.
[0024]
Next, the principle of the sound absorbing mechanism according to the present invention will be described.
FIG. 2 is a diagram schematically illustrating the above-described sound absorbing mechanism of the present invention. That is, as shown in FIG. 2, the sound absorbing mechanism of the present invention is composed of a sound absorbing mechanism (a) based on the viscous resistance of air, a sound absorbing mechanism (b) of a viscoelastic body combining elastic effect and viscous resistance, and a combination of weight and elastic effect. This is realized by the action of adding the sound absorbing mechanism (c) by the dynamic vibration absorber. Such a sound absorption mechanism is particularly effective for low-frequency sound absorption such as 100 Hz or less.
[0025]
Here, when the foaming density of the open-cell foam made of viscoelastic material is increased on the sound source side and inclined to be lowered on the rigid wall side, the high-density portion plays the role of the additional mass described above, The low-density part plays a role of a spring, so that sound absorption is performed.
[0026]
On the other hand, if the foaming density is changed so as to be low on the sound source side and high on the rigid wall side, the reflection of sound waves on the surface of the open cell foam can be reduced, and the sound absorption rate can be further improved. In particular, the sound absorption effect at low frequencies is excellent.
[0027]
【Example】
Next, examples of the present invention will be described. In the examples of the present invention described below, the open cell foam used was obtained by chemically foaming a base material made of urethane-asphalt.
[0028]
<Example 1>
A sound-absorbing vibration damping material in which four open-cell foams having a thickness of 25 mm and a foaming density from the sound source side of 25.2, 73.5, 149, and 420 kg /
[0029]
<Example 2>
A sound-absorbing vibration damping material in which four open-cell foams having a thickness of 25 mm and foam densities from the sound source side of 420, 149, 73.5, and 25.2 kg /
[0030]
<Example 3>
In Example 1, the sound-absorbing vibration damping material in which a vibration damping sheet made of a viscoelastic solid body having a thickness of 0.05 mm is laminated on the sound source side.
[0031]
<Example 4>
In Example 1, the sound-absorbing material having a closed cell foam made of a viscoelastic material having a thickness of 3 mm on the sound source side.
[0032]
<Example 5>
In Example 1, the sound-absorbing vibration damping material in which a thin film of aluminum having a thickness of 0.02 mm is laminated on the sound source side.
[0033]
<Example 6>
In Example 3, the sound-absorbing vibration damping material in which a damping sheet made of a viscoelastic solid body having a thickness of 2 mm is laminated on the rigid wall side.
[0034]
<Example 7>
In Example 4, the sound-absorbing vibration damping material in which a damping sheet made of a viscoelastic solid body having a thickness of 2 mm is laminated on the rigid wall side.
[0035]
<Example 8>
In Example 5, the sound-absorbing vibration damping material in which a damping sheet made of a viscoelastic solid body having a thickness of 2 mm is laminated on the rigid wall side.
[0036]
<Comparative example 1>
A sound-absorbing material in which four glass wools with a thickness of 25 mm and foam densities from the sound source side of 20, 24, 32, and 40 kg /
[0037]
<Comparative example 2>
A sound-absorbing material in which four glass wools having a thickness of 25 mm and foaming densities from the sound source side of 40, 32, 24, and 20 kg /
[0038]
With respect to the above Examples 1 to 8 and Comparative Examples 1 and 2, the sound absorption coefficient as an index of the sound absorption characteristic and the loss coefficient as an index of the damping property were measured.
Here, the sound absorption coefficient was measured according to JIS A 1405 “Acoustic-Measurement of sound absorption coefficient and impedance by impedance tube—standing wave ratio method”. The loss factor is measured in accordance with JIS G 0602 “Test method for vibration damping characteristics of damping steel plate”. The test piece is held in the center support method, the test piece is excited in the electromagnetic vibrator, and the loss factor calculation method. The half-width method was used. The sound absorption rate was measured using an acoustic tube type sound absorption characteristic measurement system manufactured by Ontec R & D, and the loss coefficient was measured using a measuring instrument manufactured by Lion.
[0039]
FIG. 3 shows the sound absorption coefficient for each frequency in the embodiment of the present invention, and FIG. 4 shows the value of the loss coefficient for each frequency together with the comparative example.
[0040]
3 and 4, in the embodiment of the present invention, the sound absorption rate is particularly effective for a low frequency of 300 to 400 Hz or less, and the sound absorption effect is sufficiently higher than that of the comparative example even at a low frequency of 100 Hz. I understand that.
[0041]
In addition, it is clear that the loss coefficient, which is an index for reducing solid-borne sound and vibration, is superior at all frequencies as compared with the comparative example, and has an excellent effect even at a low frequency of 100 Hz or less.
[0042]
【The invention's effect】
As described above, according to the sound-absorbing vibration-damping material of the present invention, the foam density of the open-cell foam made of a viscoelastic body is changed in the thickness direction in an inclined manner, and the vibration-damping sheet made of a viscoelastic body on the sound source side. In addition, a closed cell foam or metal thin film layer made of a viscoelastic material is laminated, or a damping sheet made of a viscoelastic material is laminated on the rigid wall side, which is particularly effective for sound absorption at a low frequency of 300 to 400 Hz or less. In addition, since it is made of a viscoelastic body, it also has vibration damping properties, so that it is possible to provide a sound absorbing material that is effective in reducing solid-borne sound and vibration at all frequencies.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a sound absorbing material in the present invention.
FIG. 2 is a diagram schematically illustrating a sound absorbing mechanism of the present invention.
FIG. 3 is a diagram showing the value of the sound absorption coefficient for each frequency in the embodiment of the present invention.
FIG. 4 is a diagram showing a loss coefficient value for each frequency in the embodiment of the present invention.
[Explanation of symbols]
1 Damping
Claims (5)
前記粘弾性発泡体の音源側及び剛壁側に粘弾性体からなる充実体の制振シートを積層したことを特徴とする吸音制振材。A plurality of sheet-like viscoelastic foams having open cells inside are laminated, and the plurality of viscoelastic foams have a foam density distribution such that the foam density increases or decreases as it approaches the sound source side. In the sound absorbing material that has been adjusted,
A sound-absorbing vibration damping material, wherein a solid vibration damping sheet made of a viscoelastic material is laminated on a sound source side and a rigid wall side of the viscoelastic foam.
前記粘弾性発泡体の音源側及び剛壁側に粘弾性体からなる独立気泡発泡体を積層したことを特徴とする吸音制振材。A plurality of sheet-like viscoelastic foams having open cells inside are laminated, and the plurality of viscoelastic foams have a foam density distribution such that the foam density increases or decreases as it approaches the sound source side. In the sound absorbing material that has been adjusted,
A sound-absorbing vibration damping material, wherein a closed cell foam made of a viscoelastic material is laminated on a sound source side and a rigid wall side of the viscoelastic foam.
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| JP2001313646A JP4027068B2 (en) | 2001-10-11 | 2001-10-11 | Sound absorbing material |
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| JP2001313646A JP4027068B2 (en) | 2001-10-11 | 2001-10-11 | Sound absorbing material |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106049301A (en) * | 2016-06-29 | 2016-10-26 | 广州恒成智道信息科技有限公司 | Automatic load shedding sound barrier |
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| JP2006352647A (en) * | 2005-06-17 | 2006-12-28 | Crie Inc | Sound pressure control system in enclosed space |
| JP4745117B2 (en) * | 2006-04-28 | 2011-08-10 | 株式会社東芝 | TV with built-in hard disk |
| CN103061424B (en) * | 2011-10-21 | 2016-12-14 | 贾猛虎 | A kind of sound insulation vibration absorber |
| CN106678219B (en) * | 2015-11-06 | 2019-10-22 | 苏州三星电子有限公司 | Dynamic absorber felt and shell |
| CN110593023A (en) * | 2019-08-30 | 2019-12-20 | 罗桂花 | Vibration and noise reduction device for track floating plate |
| CN112164382A (en) * | 2020-09-07 | 2021-01-01 | 西安交通大学 | Zigzag partition board filled with viscoelastic material underwater sound absorption structure |
| CN113799450B (en) * | 2021-09-17 | 2023-10-24 | 无锡希格声声学科技有限公司 | Noise reduction damping plate made of acoustic metamaterial |
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| JPS5830546A (en) * | 1981-08-19 | 1983-02-23 | Bridgestone Corp | Vibration damper |
| JPS60137528U (en) * | 1984-02-23 | 1985-09-12 | 菱和産資株式会社 | soundproofing material |
| JPH0684052B2 (en) * | 1986-03-31 | 1994-10-26 | 日東電工株式会社 | Multi-layer soundproof material |
| JP2567597B2 (en) * | 1987-02-12 | 1996-12-25 | 株式会社ブリヂストン | Vehicle Dash Panel Structure |
| JPH01288094A (en) * | 1988-05-13 | 1989-11-20 | Toyo Tire & Rubber Co Ltd | Vibrator |
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| JPH0747557A (en) * | 1993-08-05 | 1995-02-21 | Kotobukiya Furonte Kk | Production of floor carpet of car |
| JP3273222B2 (en) * | 1993-12-28 | 2002-04-08 | アサヒゴム株式会社 | Sound insulation |
| JPH09131818A (en) * | 1995-11-09 | 1997-05-20 | Sekisui Chem Co Ltd | Damping soundproof material |
| JPH10264293A (en) * | 1997-03-27 | 1998-10-06 | Sekiyu Sangyo Kasseika Center | Soundproofing material |
| JP3620570B2 (en) * | 1998-10-14 | 2005-02-16 | 株式会社神戸製鋼所 | Partition panel structure |
| JP3741413B2 (en) * | 1999-12-22 | 2006-02-01 | ニチアス株式会社 | Sound absorbing structure |
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| JP3749050B2 (en) * | 1999-10-05 | 2006-02-22 | ニチアス株式会社 | Sound absorbing structure |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106049301A (en) * | 2016-06-29 | 2016-10-26 | 广州恒成智道信息科技有限公司 | Automatic load shedding sound barrier |
| CN106049301B (en) * | 2016-06-29 | 2018-07-03 | 广州恒成智道信息科技有限公司 | Automatic deloading sound barrier |
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| JP2003122371A (en) | 2003-04-25 |
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