JP2003041528A - Sound absorbing structure - Google Patents
Sound absorbing structureInfo
- Publication number
- JP2003041528A JP2003041528A JP2001230978A JP2001230978A JP2003041528A JP 2003041528 A JP2003041528 A JP 2003041528A JP 2001230978 A JP2001230978 A JP 2001230978A JP 2001230978 A JP2001230978 A JP 2001230978A JP 2003041528 A JP2003041528 A JP 2003041528A
- Authority
- JP
- Japan
- Prior art keywords
- plate
- sound
- absorbing structure
- sound absorbing
- perforated plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Devices Affording Protection Of Roads Or Walls For Sound Insulation (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、種々の設備、装置
等で採用可能な吸音構造体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing structure that can be used in various equipments and devices.
【０００２】[0002]
【従来の技術】音を吸収する材料として、今まで種々の
ものが提供されている。例えば、グラスウール、ロック
ウールなどの多孔質材料、孔あき石こうボード、孔あき
ハードボードなどの孔あき板構造体などが知られてい
る。2. Description of the Related Art Various materials have been provided as materials for absorbing sound. For example, porous materials such as glass wool and rock wool, perforated gypsum boards, perforated board structures such as perforated hard boards are known.
【０００３】最近では、騒音問題等から吸音材を必要と
する範囲が拡大し、それに伴い、生産性、経済性だけで
なく、今までにない機能が吸音材に要求されている。そ
の一つが、透視性である。つまり、吸音できるだけでな
く、向こう側が見通せるようになっていることである。
しかし、前述した材料は透視性のないものであった。In recent years, the range in which a sound absorbing material is required has been expanded due to noise problems and the like, and accordingly, not only productivity and economical efficiency but also an unprecedented function is required of the sound absorbing material. One of them is transparency. In other words, not only can sound be absorbed, but the other side can see through.
However, the above-mentioned materials have no transparency.
【０００４】透視性を確保したものの例として、特許第
２５１８５８９号に開示の「膜振動吸音材」がある。し
かし、これは、エキスパンドメタルやパンチングメタル
などの板状体で樹脂薄膜を挟んだものであり、透視性は
あるものの十分ではなく、しかも剛性はなく、採用でき
る箇所が限られるものであった。[0004] As an example of a material that ensures transparency, there is a "membrane vibration sound absorbing material" disclosed in Japanese Patent No. 2518589. However, this is one in which a resin thin film is sandwiched between plate-shaped members such as expanded metal and punching metal, and although it has transparency, it is not sufficient, and it is not rigid, and the places that can be adopted are limited.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、以上のよう
な状況に鑑みてなされたもので、透視性を持たせること
が可能であり、剛性等の面でも優れる吸音材を提供する
ことを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a sound-absorbing material which can be transparent and excellent in rigidity and the like. To aim.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決する第１
の発明に係る吸音構造体の構成は、板に等ピッチ又は不
等ピッチで多数の細孔を設けて多孔板とすると共に、前
記細孔の空間部分の空気を振動させようとするときの抵
抗、前記細孔の縁の部分における摩擦による抵抗、前記
細孔の空間部分の空気を介して音波を放射するときの抵
抗を考慮して、吸音を目的とする周波数（ターゲット周
波数）に対しての、前記多孔板の表面インピーダンス
が、空気の密度と音速との積で定まるインピーダンスに
近づくように、前記多孔板の表面に対する前記細孔の開
口率を定めたことを特徴とする。[Means for Solving the Problems] First to solve the above problems
The structure of the sound absorbing structure according to the invention, the plate is provided with a large number of pores at an equal pitch or unequal pitch to form a perforated plate, and resistance when trying to vibrate the air in the space portion of the pores. In consideration of the resistance due to friction at the edge portion of the pores and the resistance when sound waves are radiated through the air in the space portion of the pores, considering the sound absorption target frequency (target frequency), The aperture ratio of the pores with respect to the surface of the perforated plate is determined so that the surface impedance of the perforated plate approaches an impedance determined by the product of the density of air and the speed of sound.
【０００７】上記課題を解決する第２の発明に係る吸音
構造体の構成は、上記第１の発明において、前記多孔板
における音源側と反対の側に、前記多孔板と所定の間隔
をあけて第２の板を設け、吸音を目的とする周波数に対
しての、前記多孔板の表面インピーダンスが、空気の密
度と音速との積で定まるインピーダンスに近づくよう
に、前記開口率、及び前記多孔板と第２の板の間の間隔
を定めたことを特徴とする。The structure of the sound absorbing structure according to the second invention for solving the above-mentioned problems is the same as in the first invention, wherein a predetermined space is provided between the perforated plate and the side opposite to the sound source side. A second plate is provided, and the aperture ratio and the perforated plate are set so that the surface impedance of the perforated plate with respect to a frequency for sound absorption approaches an impedance determined by a product of air density and sound velocity. And a second plate is defined as a space.
【０００８】上記課題を解決する第３の発明に係る吸音
構造体の構成は、上記第２の発明において、前記第２の
板に等ピッチ又は不等ピッチで多数の細孔をあけたこと
を特徴とする。The structure of the sound absorbing structure according to the third invention for solving the above problems is that in the second invention, a large number of pores are formed in the second plate at equal pitches or unequal pitches. Characterize.
【０００９】上記課題を解決する第４の発明に係る吸音
構造体の構成は、上記第１の発明において、前記多孔板
の片側又は両側に空気の流れを形成することを特徴とす
る。空気の流れは、多孔板における音源側の面、音源側
と反対側の面又はその両方に沿って形成される。空気の
流れを形成する手段としては、ファンなどが採用され
る。また、冷房や空調などの空気の流れを利用すること
もできる。A structure of a sound absorbing structure according to a fourth invention for solving the above-mentioned problems is characterized in that, in the first invention, an air flow is formed on one side or both sides of the perforated plate. The air flow is formed along the sound source side surface of the perforated plate, the surface opposite to the sound source side, or both. A fan or the like is used as a means for forming the flow of air. In addition, it is possible to use the air flow such as cooling and air conditioning.
【００１０】上記課題を解決する第５の発明に係る吸音
構造体の構成は、上記第２又は第３の発明において、前
記多孔板と前記第２の板との間に空気の流れを形成する
ことを特徴とする。空気の流れを形成する手段として
は、ファンなどが採用される。また、冷房や空調などの
空気の流れを利用することもできる。The structure of the sound absorbing structure according to the fifth invention for solving the above-mentioned problems is that in the above-mentioned second or third invention, an air flow is formed between the perforated plate and the second plate. It is characterized by A fan or the like is used as a means for forming the flow of air. In addition, it is possible to use the air flow such as cooling and air conditioning.
【００１１】上記課題を解決する第６の発明に係る吸音
構造体の構成は、上記第４又は第５の発明において、前
記空気の流れの速度を考慮して前記開口率を定めたこと
を特徴とする。The structure of the sound absorbing structure according to the sixth invention for solving the above-mentioned problems is characterized in that, in the above-mentioned fourth or fifth invention, the opening ratio is determined in consideration of the velocity of the air flow. And
【００１２】上記課題を解決する第７の発明に係る吸音
構造体の構成は、上記第１ないし６のいずれかの発明に
おいて、前記多孔板又は前記第２の板又は前記多孔板及
び前記第２の板の双方が透明な板状材料であることを特
徴とする。透明な板状材料としては、例えばアクリル樹
脂等が用いられる。The structure of a sound absorbing structure according to a seventh invention for solving the above-mentioned problems is the porous plate or the second plate or the porous plate and the second plate according to any one of the first to sixth inventions. Both of the plates are transparent plate-shaped materials. As the transparent plate-shaped material, for example, acrylic resin or the like is used.
【００１３】上記課題を解決する第８の発明に係る吸音
構造体の構成は、上記第１、３、５、６のいずれかの発
明において、前記多孔板と前記第２の板との間に、各板
とほぼ直交する複数の仕切り板を設けたことを特徴とす
る。The structure of the sound absorbing structure according to the eighth invention for solving the above-mentioned problems is the structure according to any one of the first, third, fifth and sixth inventions, wherein the porous plate and the second plate are arranged between the porous plate and the second plate. , A plurality of partition plates that are substantially orthogonal to the respective plates are provided.
【００１４】上記課題を解決する第９の発明に係る吸音
構造体の構成は、上記第８の発明において、前記複数の
仕切り板が透明な板状材料であることを特徴とする。透
明な板状材料としては、多孔板、第２の板と同様に、例
えばアクリル樹脂等が用いられる。A structure of a sound absorbing structure according to a ninth invention for solving the above-mentioned problems is characterized in that, in the eighth invention, the plurality of partition plates are transparent plate-shaped materials. As the transparent plate-shaped material, for example, acrylic resin or the like is used similarly to the porous plate and the second plate.
【００１５】上記課題を解決する第１０の発明に係る吸
音構造体の構成は、上記第１ないし９のいずれかの発明
において、前記多孔板又は前記第２の板における前記細
孔を塞ぐフィルムを設けたことを特徴とする。フィルム
は、通気性のものであっても非通気性のものであっても
よい。また、フィルムは、各細孔ごとに設けてもよい
し、多孔板の全面を覆うものであってもよい。The structure of the sound absorbing structure according to the tenth invention for solving the above-mentioned problems is that in any one of the above-mentioned first to ninth inventions, a film for closing the pores in the perforated plate or the second plate is used. It is characterized by being provided. The film may be breathable or non-breathable. In addition, the film may be provided for each pore, or may cover the entire surface of the perforated plate.
【００１６】上記課題を解決する第１１の発明に係る吸
音構造体の構成は、上記第１ないし１０のいずれかの発
明において、前記多孔板又は前記第２の板における前記
細孔の直径が前記多孔板又は前記第２の板の厚さより小
さいことを特徴とする。The structure of the sound absorbing structure according to the eleventh invention for solving the above-mentioned problems is the invention according to any one of the first to tenth inventions, wherein the diameter of the pores in the perforated plate or the second plate is the above-mentioned. It is characterized in that it is smaller than the thickness of the perforated plate or the second plate.
【００１７】上記課題を解決する第１２の発明に係る吸
音構造体の構成は、上記第１、３、６、７のいずれかの
発明において、前記多孔板又は前記第２の板の表面に対
する前記細孔の開口率を１０％以下としたことを特徴と
する。The structure of a sound absorbing structure according to a twelfth invention for solving the above-mentioned problems is the above-mentioned first, third, sixth or seventh invention, wherein the sound absorbing structure is formed on the surface of the perforated plate or the second plate. The aperture ratio of the pores is 10% or less.
【００１８】上記課題を解決する第１３の発明に係る吸
音構造体の構成は、上記第１の発明において、吸音率が
０．５以上となるように、吸音を目的とする周波数に対
しての、前記多孔板の表面インピーダンスが、空気の速
度と音速との積で定まるインピーダンスに近づくように
前記開口率を定めたことを特徴とする。The structure of the sound absorbing structure according to the thirteenth invention for solving the above-mentioned problems is the sound absorbing structure according to the first invention, wherein the sound absorption coefficient is 0.5 or more with respect to the frequency of sound absorption. The aperture ratio is set so that the surface impedance of the perforated plate approaches an impedance determined by the product of the velocity of air and the speed of sound.
【００１９】上記課題を解決する第１４の発明に係る吸
音構造体の構成は、上記第１の発明において、吸音率が
０．５以上となるように、吸音を目的とする周波数に対
しての、前記多孔板の表面インピーダンスが、空気の速
度と音速との積で定まるインピーダンスに近づくように
前記開口率及び前記空気の流れの速度を定めたことを特
徴とする。なお、吸音率を０．５以上としたのは、実用
上効果のある吸音構造体を得るためである。The structure of the sound absorbing structure according to the fourteenth invention for solving the above-mentioned problems is the sound absorbing structure for the frequency for which sound absorption is intended in the first invention, so that the sound absorbing coefficient becomes 0.5 or more. The aperture ratio and the velocity of the air flow are set so that the surface impedance of the perforated plate approaches an impedance determined by the product of the velocity of the air and the sound velocity. The sound absorption coefficient is set to 0.5 or more in order to obtain a sound absorbing structure that is practically effective.
【００２０】上記課題を解決する第１５の発明に係る吸
音構造体の構成は、上記第１の発明において、吸音率が
０．５以上となるように、吸音を目的とする周波数に対
しての、前記多孔板の表面インピーダンスが、空気の密
度と音速との積で定まるインピーダンスに近づくよう
に、前記開口率、及び前記多孔板と前記第２の板との間
の間隔を定めたことを特徴とする。The structure of the sound absorbing structure according to the fifteenth invention for solving the above-mentioned problems is the sound absorbing structure according to the first invention, wherein the sound absorption coefficient is 0.5 or more with respect to the frequency of sound absorption. The aperture ratio and the distance between the porous plate and the second plate are set so that the surface impedance of the porous plate approaches an impedance determined by the product of air density and sound velocity. And
【００２１】上記課題を解決する第１６の発明に係る吸
音構造体の構成は、上記第１の発明において、吸音率が
０．５以上となるように、吸音を目的とする周波数に対
しての、前記多孔板の表面インピーダンスが、空気の密
度と音速との積で定まるインピーダンスに近づくよう
に、前記開口率、前記多孔板と前記第２の板との間の間
隔、及び前記空気の流れの速度を定めたことを特徴とす
る。The structure of the sound absorbing structure according to the sixteenth invention for solving the above-mentioned problem is the sound absorbing structure according to the first invention, in which the sound absorption coefficient is 0.5 or more with respect to the target frequency of sound absorption. , So that the surface impedance of the perforated plate approaches the impedance determined by the product of the density of air and the speed of sound, the aperture ratio, the distance between the perforated plate and the second plate, and the flow of the air. It is characterized by setting the speed.
【００２２】本発明に係る吸音構造体は、更に具体的に
は、第１の板と、第１の板と間隔（背後層）をあけて設
けた第２の板とからなり、第１の板に細孔を設け、第１
の板と第２の板との間に空気を流すようにした吸音構造
体においては、吸音の目標とする音の周波数が８００Ｈ
ｚである場合には、前記第１の板の開口率を０．８〜
３．１％、背後層を１４〜５０ｍｍ、空気流の流速を５
〜１５ｍ／ｓとしたことを特徴とする。More specifically, the sound absorbing structure according to the present invention comprises a first plate and a second plate spaced apart from the first plate (a back layer). First, the plate has pores
In the sound absorbing structure in which air is made to flow between the plate of No. 2 and the plate of No. 2, the frequency of the sound to be absorbed is 800H.
When it is z, the aperture ratio of the first plate is 0.8 to
3.1%, the back layer 14 to 50 mm, the air flow velocity 5
It is characterized in that it is set to -15 m / s.
【００２３】[0023]
【実施の形態】次に、本発明に係る吸音構造体の実施の
形態について説明する。図１には本発明の一実施形態に
係る吸音構造体の一部の斜視外観を示す。板（多孔板）
１は透明なアクリル樹脂により形成されており、この板
１に、等ピッチで多数の細孔２があけられている。細孔
２の板１の表面積に対する割合、即ち開口率は１０％以
下と、吸音に使われる通常の穴開き板に比べはるかに小
さくなっている。BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the sound absorbing structure according to the present invention will be described. FIG. 1 shows a perspective external view of a part of a sound absorbing structure according to an embodiment of the present invention. Plate (perforated plate)
1 is made of a transparent acrylic resin, and a large number of pores 2 are formed in this plate 1 at equal pitches. The ratio of the pores 2 to the surface area of the plate 1, that is, the opening ratio is 10% or less, which is much smaller than that of a normal perforated plate used for sound absorption.
【００２４】開口率は、種々の条件により変更される。
例えば、吸音対象の音の周波数、つまりターゲット周波
数などに応じて変更される。開口率は、基本的には、そ
の当該吸音構造体のインピーダンスが、空気のインピー
ダンス（媒質の密度（ρ）×音速（ｃ））に近づくよう
に設定されるが、吸音構造体に要求される他の要素、例
えば強度を確保するための板の厚さなどが考慮される。
つまり、吸音構造体として所望の強度を確保するために
は、板厚は必然的に決まり、それに応じて細孔２の径、
開口率が定まる。The aperture ratio is changed according to various conditions.
For example, it is changed according to the frequency of the sound to be absorbed, that is, the target frequency. The aperture ratio is basically set so that the impedance of the sound absorbing structure approaches the impedance of air (medium density (ρ) × sound velocity (c)), but is required for the sound absorbing structure. Other factors are considered, such as the thickness of the plate to ensure strength.
That is, in order to secure the desired strength as the sound absorbing structure, the plate thickness is inevitably determined, and accordingly, the diameter of the pores 2,
The aperture ratio is fixed.
【００２５】当該吸音構造体に当たる音のエネルギは、
前記細孔２の空間部分の空気を振動させようとするとき
の抵抗（質量抵抗）、前記細孔２の縁の部分における摩
擦による抵抗（摩擦抵抗）、細孔２の空間部分の空気を
介して音波を放射するときの抵抗（放射抵抗）により吸
収される。従って、細孔２を適宜設計、つまり板１の板
厚、細孔２の径、開口率を適宜設計することにより、タ
ーゲット周波数に対し効果的に吸音を行うことができ
る。The energy of the sound hitting the sound absorbing structure is
Via the resistance (mass resistance) when trying to vibrate the air in the space of the pores 2, the resistance due to friction at the edge of the pores 2 (friction resistance), the air in the space of the pores 2 Is absorbed by the resistance (radiation resistance) when radiating sound waves. Therefore, by appropriately designing the pores 2, that is, by appropriately designing the plate thickness of the plate 1, the diameter of the pores 2, and the aperture ratio, it is possible to effectively absorb sound at the target frequency.
【００２６】多孔板のインピーダンスＺを、多孔板表面
での音圧ｐ＝ｐexp(ｉωｔ）と多孔板表面での粒子速度
法線方向成分ｕn ＝ｕn exp(ｉωｔ）の比Ｚ＝ｐ／ｕn
で定義する。ｕn の正方向を、入射音波の進行方向と一
致するようにとる。多孔板の背後に空気層があり、更
に、その背後は剛壁とする。多孔板のインピーダンスは
以下のように評価される。The impedance Z of the perforated plate is expressed by the ratio Z = p / of the sound pressure p = pexp (iωt) on the surface of the perforated plate and the particle velocity normal direction component u n = u n exp (iωt) on the surface of the perforated plate. u n
Define in. The positive direction of u n is taken to coincide with the traveling direction of the incident sound wave. There is an air layer behind the perforated plate, and behind it is a rigid wall. The impedance of the perforated plate is evaluated as follows.
【００２７】[0027]
【数１】 [Equation 1]
【００２８】ただし、 ν ：ガスの動粘性係数（m2/s） Ｍ0 ：音波の粒子速度のマッハ数（−） Ｍ ：板に沿うマッハ数（−） θ ：入射角(rad) （垂直入射は０(rad)) ω ：音波の角周波数(rad/s) κ ：音波の波数(=２π/ λ) ｂ ：背後層の厚さ（ｍ） ρ ：空気の密度(kg/m3) ｃ ：音速（m/s) ρp ：多孔板の開口率（−） ｔ ：多孔板の厚さ（ｍ） ｄ ：孔の直径（ｍ） λ ：音波の波長（ｍ）Where ν: kinematic viscosity coefficient of gas (m 2 / s) M 0 : Mach number (-) of particle velocity of sound wave M: Mach number along plate (-) θ: incident angle (rad) (vertical Incident is 0 (rad)) ω: Angular frequency of sound wave (rad / s) κ: Wave number of sound wave (= 2π / λ) b: Thickness of back layer (m) ρ: Air density (kg / m 3 ) c: speed of sound (m / s) ρ p : aperture ratio of perforated plate (-) t: thickness of perforated plate (m) d: diameter of hole (m) λ: wavelength of sound wave (m)
【数２】
式（１）において、添字の「１」は多孔板の音源側、添
字の「２」は音源と反対側を意味する。[Equation 2] In the formula (1), the subscript “1” means the sound source side of the perforated plate, and the subscript “2” means the opposite side to the sound source.
【００２９】垂直入射する音波に対する多孔板の音響反
射率Ｒは、インピーダンスＺを用いて次式にて評価され
る。The acoustic reflectance R of the perforated plate with respect to a sound wave that is vertically incident is evaluated by the following equation using the impedance Z.
【数３】 [Equation 3]
【００３０】音響反射率Ｒと吸音率αの関係は以下の通
りである。The relationship between the acoustic reflectance R and the sound absorption coefficient α is as follows.
【数４】 [Equation 4]
【００３１】上記式は、図２に示すように、多孔板と板
との組み合わせの場合の式であるが、一重多孔板、二重
多孔板の場合も同様の考えで式を構築することができ
る。As shown in FIG. 2, the above equation is an equation in the case of a combination of perforated plates and plates. However, the equation can be constructed by the same idea in the case of a single perforated plate and a double perforated plate. it can.
【００３２】この実施形態によれば、当該吸音構造体に
より音を吸収することができると共に、板１が透明であ
るので、吸音構造体の双方の側から他方側の様子を視認
することができる。勿論、透視性を必要としない場合に
は、板１は透明である必要はない。また、板１の材料と
しても、アクリル樹脂に限らず、プラスチック、その他
の材料を使用することができる。According to this embodiment, sound can be absorbed by the sound absorbing structure, and since the plate 1 is transparent, the state of the sound absorbing structure on the other side can be visually recognized. . Of course, the plate 1 does not need to be transparent if transparency is not required. Further, the material of the plate 1 is not limited to acrylic resin, and plastic or other material can be used.
【００３３】更に、音のエネルギは空気の流れの境界層
における抵抗によっても吸収される。従って、図３に示
すように、板１における、音が来る側（図３において矢
印を記載した側）の裏面に沿って並行な空気の流れが形
成されるようにする。この空気の流れの形成は、ファン
などにより形成される。冷房や空調などの空気の流れで
兼用することもできる。このように、空気流Ａを形成す
るようにした場合には、空気流Ａの流速も開口率を決定
する要素となる。また、空気流Ａを形成することによ
り、透明な板１の結露、曇りを防ぐことができ、細孔２
にほこりが詰まりにくくもなる。更に、この例では細孔
２内の空気の流速が増すことにより、吸音性能も向上し
ている。In addition, sound energy is also absorbed by resistance in the boundary layer of the air flow. Therefore, as shown in FIG. 3, a parallel air flow is formed along the back surface of the plate 1 on the side where the sound comes (the side indicated by the arrow in FIG. 3). The formation of this air flow is formed by a fan or the like. It can also be used as an air flow for cooling and air conditioning. In this way, when the air flow A is formed, the flow velocity of the air flow A is also a factor that determines the aperture ratio. Further, by forming the air flow A, it is possible to prevent the transparent plate 1 from dew condensation and fogging, and to form the pores 2
It also prevents dust from clogging. Further, in this example, the sound absorbing performance is also improved by increasing the flow velocity of the air in the pores 2.
【００３４】板１が長尺である場合には、１台のファン
のみによって板１の全長に亘って並行な空気量Ａを形成
することは困難であるので、ファンを複数台設置した
り、板１に沿い適当な間隔でパイプを立て、そのパイプ
から空気を噴出させるようにしてもよい。When the plate 1 is long, it is difficult to form the parallel air amount A over the entire length of the plate 1 by only one fan, so that a plurality of fans may be installed, Pipes may be erected at appropriate intervals along the plate 1, and air may be ejected from the pipes.
【００３５】板１に穿設してある多数の細孔２がほこり
等が詰まってしまうと、吸音性能が低下してしまうの
で、空気流Ａを形成するだけではなく、図４に示すよう
に、細孔２の入口及び出口に、通気性又は非通気性のフ
ィルム３を貼ってほこり等が入らないようにしてもよ
い。フィルム３は、音を通すものとし、吸音性能に影響
を与えないようにする。なお、図４では、各細孔２ごと
にフィルムを設けるようにしているが、板１の表裏面全
面を覆うようにフィルム３を張ってもよい。If a large number of pores 2 formed in the plate 1 are clogged with dust or the like, the sound absorbing performance will be deteriorated, so that not only the air flow A is formed but also as shown in FIG. A breathable or non-breathable film 3 may be attached to the entrance and exit of the pores 2 to prevent dust and the like from entering. The film 3 transmits sound and does not affect the sound absorbing performance. Although a film is provided for each pore 2 in FIG. 4, the film 3 may be stretched so as to cover the entire front and back surfaces of the plate 1.
【００３６】図５には他の実施の形態を示す。この実施
の形態は、図１及び図３に示した板１の背後側、つまり
音源側と反対の側に更に第２の板４を設け、吸音に寄与
する空間を形成したものである。この板１と２との間の
空気層、つまり背後層５の厚さｂが吸音性に影響を与え
る。透視性を必要とする場合には、この第２の板４を、
例えば透明なアクリル樹脂などで製作する。この吸音構
造体では、音は板１により前述の如く吸音され、板１と
４との間に入った音は、この間に閉じ込められ、吸音構
造体の裏側に漏れることはない。板１と４間にファン等
により空気流Ａを形成することにより更なる吸音が図れ
る。FIG. 5 shows another embodiment. In this embodiment, a second plate 4 is further provided on the back side of the plate 1 shown in FIGS. 1 and 3, that is, on the side opposite to the sound source side to form a space that contributes to sound absorption. The air layer between the plates 1 and 2, that is, the thickness b of the back layer 5 affects the sound absorption. When the transparency is required, this second plate 4 is
For example, it is made of transparent acrylic resin. In this sound absorbing structure, the sound is absorbed by the plate 1 as described above, and the sound entering between the plates 1 and 4 is trapped between them and does not leak to the back side of the sound absorbing structure. Further sound absorption can be achieved by forming the air flow A between the plates 1 and 4 with a fan or the like.
【００３７】図６には図５に示した吸音構造体の一実施
例の、周波数に対する吸音率を示す。この実施例は、吸
音の対象とする周波数８００Ｈｚをターゲット周波数と
したもので、板１の厚さは４ｍｍであり、細孔２の径を
１ｍｍ、開口率を２．３％、孔ピッチを６．４ｍｍ、背
後層５の厚さｂを２１ｍｍ、板１と４との間に流す空気
流の速度を１０ｍ／ｓとして設計したものである。図６
からわかるように、ターゲット周波数である８００Ｈｚ
では吸音率は、１．０となっている。また、６００Ｈｚ
〜１１００Ｈｚ間では、０．５以上の高い吸音率を示
す。この例からもわかるように、細孔２の径、開口率
は、かなり小さいものであることがわかる。FIG. 6 shows the sound absorption coefficient with respect to frequency of the embodiment of the sound absorbing structure shown in FIG. In this example, the target frequency is 800 Hz, which is the target of sound absorption, the thickness of the plate 1 is 4 mm, the diameter of the pores 2 is 1 mm, the aperture ratio is 2.3%, and the hole pitch is 6 mm. The thickness of the back layer 5 was designed to be 21 mm and the velocity of the air flow flowing between the plates 1 and 4 was 10 m / s. Figure 6
As you can see, the target frequency is 800Hz
The sound absorption coefficient is 1.0. Also, 600 Hz
A high sound absorption coefficient of 0.5 or more is exhibited between 1100 Hz. As can be seen from this example, it can be seen that the diameter and aperture ratio of the pores 2 are quite small.
【００３８】図７〜９はいずれも同様の構造の吸音構造
体において、８００Ｈｚをターゲット周波数としたもの
で、細孔２のピッチは１１ｍｍである。開口率、背後
層、流速を変更することにより、吸音率、効果的な吸音
のできる範囲が変わることがわかる。これらの図より、
８００Ｈｚを中心とした範囲の周波数の音を吸音のター
ゲットとした場合、０．５以上の吸音率を得る場合に
は、開口率を０．８％〜３．１％、背後層を１４ｍｍ〜
５０ｍｍ、流速を５ｍ／ｓ〜１５ｍ／ｓにすればよいこ
とがわかる。7 to 9 show a sound absorbing structure having the same structure with a target frequency of 800 Hz, and the pitch of the pores 2 is 11 mm. It can be seen that the sound absorption coefficient and the effective sound absorption range are changed by changing the aperture ratio, the back layer, and the flow velocity. From these figures,
When a sound with a frequency in the range around 800 Hz is used as a sound absorption target, in order to obtain a sound absorption coefficient of 0.5 or more, the aperture ratio is 0.8% to 3.1% and the back layer is 14 mm to.
It can be seen that the flow rate may be 50 mm and the flow velocity may be 5 m / s to 15 m / s.
【００３９】図１０は図５に示した実施の形態におい
て、更に第２の板４にも細孔６をあけたものである。従
って、第２の板４の細孔６によっても吸音がなされる。
第２の板４の細孔６は、吸音するターゲット周波数に応
じて、径、開口率を定めることができる。具体的には、
板１の厚さ、細孔２の径と数、板４の厚さ、細孔６の径
と数によりターゲット周波数が決まる。FIG. 10 shows the second embodiment in which pores 6 are further formed in the embodiment shown in FIG. Therefore, sound is also absorbed by the pores 6 of the second plate 4.
The diameter and the aperture ratio of the pores 6 of the second plate 4 can be determined according to the target frequency of sound absorption. In particular,
The target frequency is determined by the thickness of the plate 1, the diameter and number of the pores 2, the thickness of the plate 4, and the diameter and number of the pores 6.
【００４０】図１１に示すものは他の実施の形態に係る
吸音構造体で、図１０に示した吸音構造体における板１
と４との間に複数の仕切り板７を設けたものである。仕
切り板７を設けたことにより板１と４に並行な方向の音
波の伝播を抑制することができる。仕切り板７は、吸音
の対象となる音波の最小波長の１／４程度以下とすると
効果的である。吸音構造体の透明性を保つためにはこの
仕切り板７も透明なアクリル樹脂などで作製する。この
実施形態では、仕切り板７は、第２の板４と一体に形成
してあるが、第１の板１と一体に形成してもよいし、別
途製作したものを板１と４との間に挟み込んでもよい。
なお、仕切り板７を設けることにより、背後層の厚さｂ
の調整が自動的にできるようになる。FIG. 11 shows a sound absorbing structure according to another embodiment, which is the plate 1 in the sound absorbing structure shown in FIG.
A plurality of partition plates 7 are provided between the parts 4 and 4. By providing the partition plate 7, it is possible to suppress the propagation of sound waves in a direction parallel to the plates 1 and 4. It is effective that the partition plate 7 has a length of about ¼ or less of the minimum wavelength of the sound wave to be absorbed. In order to maintain the transparency of the sound absorbing structure, the partition plate 7 is also made of transparent acrylic resin or the like. In this embodiment, the partition plate 7 is formed integrally with the second plate 4, but it may be formed integrally with the first plate 1 or a separately manufactured plate is used as the partition plate 7. It may be sandwiched between them.
By providing the partition plate 7, the thickness b of the back layer is
Can be adjusted automatically.
【００４１】本発明に係る吸音構造体は、吸音を必要と
するあらゆる箇所に使用することができ、透視性を持た
せた場合には、工場、道路等の透光遮音壁、作業機械等
の運転席の窓、電車等の客席の窓、オペレータルームの
窓などに利用できる。The sound absorbing structure according to the present invention can be used in any place where sound absorption is required, and when it is provided with transparency, it can be used for operation of transparent sound insulating walls such as factories and roads, work machines, etc. It can be used for seat windows, passenger seat windows such as trains, operator room windows, etc.
【００４２】[0042]
【発明の効果】第１の発明に係る吸音構造体によれば、
板に等ピッチ又は不等ピッチで多数の細孔を設けて多孔
板とすると共に、前記細孔の空間部分の空気を振動させ
ようとするときの抵抗、前記細孔の縁の部分における摩
擦による抵抗、前記細孔の空間部分の空気を介して音波
を放射するときの抵抗を考慮して、吸音を目的とする周
波数（ターゲット周波数）に対しての、前記多孔板の表
面インピーダンスが、空気の密度と音速との積で定まる
インピーダンスに近づくように、前記多孔板の表面に対
する前記細孔の開口率を定めたので、吸音したい周波数
に対し有効な吸音効果が得られる。また、ある程度の厚
さの板を用い、しかも開口率が小さくなるので、強度を
維持することができる。According to the sound absorbing structure of the first invention,
The plate is provided with a large number of pores at equal pitches or unequal pitches to form a perforated plate, and resistance when trying to vibrate the air in the space portion of the pores, due to friction at the edge portion of the pores Considering the resistance and the resistance when sound waves are radiated through the air in the space of the pores, the surface impedance of the perforated plate with respect to the frequency of sound absorption (target frequency) is Since the aperture ratio of the pores to the surface of the perforated plate is set so as to approach the impedance determined by the product of the density and the sound velocity, an effective sound absorbing effect can be obtained for the frequency at which sound is desired to be absorbed. Moreover, since a plate having a certain thickness is used and the aperture ratio is small, the strength can be maintained.
【００４３】第２の発明に係る吸音構造体によれば、上
記第１の発明において、前記多孔板における音源側と反
対の側に、前記多孔板と所定の間隔をあけて第２の板を
設け、吸音を目的とする周波数に対しての、前記多孔板
の表面インピーダンスが、空気の密度と音速との積で定
まるインピーダンスに近づくように、前記開口率、及び
前記多孔板と第２の板の間の間隔を定めたので、多孔板
の背後に吸音に寄与する背後層（空気層）が形成される
ことから、吸音効果が向上する。According to the sound absorbing structure of the second invention, in the first invention, the second plate is provided on the side of the perforated plate opposite to the sound source side with a predetermined distance from the perforated plate. The aperture ratio and the space between the porous plate and the second plate are provided so that the surface impedance of the porous plate with respect to the frequency of sound absorption is close to the impedance determined by the product of the density of air and the sound velocity. Since the interval is defined, a back layer (air layer) that contributes to sound absorption is formed behind the perforated plate, so that the sound absorbing effect is improved.
【００４４】第３の発明に係る吸音構造体によれば、上
記第２の発明において、前記第２の板に等ピッチ又は不
等ピッチで多数の細孔をあけたので、二つの板により二
重に吸音を行うことができる。第２の板を第１の板と同
じ構造、つまり細孔の径、開口率とすれば、同じ周波数
の音に対し、二重に吸音することができる。According to the sound absorbing structure of the third invention, in the second invention, since a large number of pores are formed in the second plate at equal pitches or unequal pitches, it is possible to form two holes by two plates. It can absorb sound heavily. If the second plate has the same structure as the first plate, that is, the diameter of the pores and the opening ratio, it is possible to doubly absorb sound of the same frequency.
【００４５】第４の発明に係る吸音構造体によれば、上
記第１の発明において、前記多孔板の片側又は両側に空
気の流れを形成するようにしたので、空気の流れによる
境界層の抵抗によっても吸音が図れ、吸音効果が向上す
る。また、空気流によって細孔内へのほこり等の侵入が
防止され、吸音効果の低減を防ぐことができ、板の結
露、曇りも防止される。According to the sound absorbing structure of the fourth aspect of the present invention, in the first aspect of the invention, since the air flow is formed on one side or both sides of the perforated plate, the resistance of the boundary layer due to the air flow. Sound absorption is also achieved by the sound absorption effect. In addition, the airflow prevents dust and the like from entering the pores, prevents the sound absorbing effect from being reduced, and prevents dew condensation and fogging on the plate.
【００４６】第５の発明に係る吸音構造体によれば、上
記第２又は第３の発明において、前記多孔板と前記第２
の板との間に空気の流れを形成するようにしたので、空
気の流れによる境界層の抵抗によっても吸音が図れ、吸
音効果が向上する。また、空気の流れによって細孔内へ
のほこり等の侵入が防止され、吸音効果の低減を防ぐこ
とができ、板の結露、曇りも防止される。According to the sound absorbing structure of the fifth invention, in the second or third invention, the perforated plate and the second plate are provided.
Since a flow of air is formed between the plate and the plate, sound can be absorbed by the resistance of the boundary layer due to the flow of air, and the sound absorbing effect is improved. Further, the flow of air prevents dust and the like from entering the pores, prevents the sound absorbing effect from being reduced, and prevents dew condensation and fogging on the plate.
【００４７】第６の発明に係る吸音構造体によれば、上
記第４又は第５の発明において、前記空気の流れの速度
を考慮して前記開口率を定めたので、種々の要素を考慮
した最適な吸音構造体を得ることができる。According to the sound absorbing structure of the sixth aspect of the invention, in the fourth or fifth aspect of the invention, the aperture ratio is determined in consideration of the velocity of the air flow, so various factors are considered. An optimum sound absorbing structure can be obtained.
【００４８】第７の発明に係る吸音構造体によれば、上
記第１ないし６のいずれかの発明において、前記多孔板
又は前記第２の板又は前記多孔板及び前記第２の板の双
方が透明な板状材料であるので、透視性を確保すること
ができ、透光、視認性などを必要とする種々の箇所に使
用範囲が拡大する。例えば、遮音と採光とを必要とする
工場の壁、騒音を発生する機械の窓、車両の窓などに利
用できる。従来の透光板型の遮音壁のその動作は反射型
であり、陽光の透過の点では優れるが、騒音エネルギを
吸収減衰する動作はできなかった。本発明によれば、陽
光の透過性能の劣化は最小にかつ透過部面積の減少もな
く、吸収型効果を持つ透明な遮音板、遮音壁が実現でき
る。According to the sound absorbing structure of the seventh invention, in any one of the first to sixth inventions, the perforated plate or the second plate or both the perforated plate and the second plate are Since it is a transparent plate-shaped material, it is possible to ensure transparency, and the range of use is expanded to various places where light transmission, visibility, etc. are required. For example, it can be used for a factory wall that requires sound insulation and lighting, a machine window that generates noise, a vehicle window, and the like. The operation of the conventional transparent plate type sound insulation wall is a reflection type, and although it is excellent in the transmission of sunlight, it cannot perform the operation of absorbing and attenuating noise energy. According to the present invention, it is possible to realize a transparent sound insulating plate and a sound insulating wall having an absorption type effect, with minimum deterioration of sunlight transmission performance and no reduction in the area of the transmission portion.
【００４９】第８の発明に係る吸音構造体によれば、上
記第１、３、５、６のいずれかの発明において、前記多
孔板と前記第２の板との間に、各板とほぼ直交する複数
の仕切り板を設けたので、板と並行な方向の音波の伝播
を抑制することができ、更なる吸音を図ることができ
る。According to an eighth aspect of the sound absorbing structure, in any one of the first, third, fifth and sixth aspects of the invention, the plate and the plate are substantially disposed between the perforated plate and the second plate. Since a plurality of partition plates that are orthogonal to each other are provided, it is possible to suppress the propagation of sound waves in a direction parallel to the plates and to further absorb sound.
【００５０】第９の発明に係る吸音構造体によれば、上
記第８の発明において、前記複数の仕切り板を透明な板
状材料としたので、吸音構造体の透視性が確保できる。According to the sound absorbing structure of the ninth invention, in the eighth invention, since the plurality of partition plates are transparent plate-shaped materials, the transparency of the sound absorbing structure can be secured.
【００５１】第１０の発明に係る吸音構造体によれば、
上記第１ないし９のいずれかの発明において、前記多孔
板又は前記第２の板における前記細孔を塞ぐフィルムを
設けたので、細孔内へのほこり等の侵入を確実に防ぐこ
とができる。According to the sound absorbing structure of the tenth invention,
In any one of the first to ninth inventions, since the film that closes the pores in the porous plate or the second plate is provided, it is possible to reliably prevent intrusion of dust and the like into the pores.
【００５２】第１１の発明に係る吸音構造体の構成は、
上記第１ないし１０のいずれかの発明において、前記多
孔板又は前記第２の板における前記細孔の直径を前記多
孔板又は前記第２の板の厚さより小さくしたので、今ま
でにない低い開口率の吸音構造体を得ることができる。The structure of the sound absorbing structure according to the eleventh invention is as follows.
In any one of the first to tenth aspects of the invention, since the diameter of the pores in the perforated plate or the second plate is made smaller than the thickness of the perforated plate or the second plate, an unprecedentedly low opening. It is possible to obtain a high-accuracy sound absorbing structure.
【００５３】第１２の発明に係る吸音構造体によれば、
上記第１、３、６、７のいずれかの発明において、前記
多孔板又は前記第２の板の表面に対する前記細孔の開口
率を１０％以下としたので、従来の穴開き板に比べ格段
に優れた吸音性を発揮する。ある程度の厚さの板を用
い、しかも開口率を小さくするので、強度を維持でき
る。According to the sound absorbing structure of the twelfth invention,
In any one of the first, third, sixth, and seventh inventions, the aperture ratio of the pores to the surface of the perforated plate or the second plate is set to 10% or less, so that it is significantly higher than that of a conventional perforated plate. Excellent sound absorption. Since a plate having a certain thickness is used and the aperture ratio is reduced, the strength can be maintained.
【００５４】第１３の発明に係る吸音構造体によれば、
上記第１の発明において、吸音率が０．５以上となるよ
うに、吸音を目的とする周波数に対しての、前記多孔板
の表面インピーダンスが、空気の速度と音速との積で定
まるインピーダンスに近づくように前記開口率を定めた
ので、得たい吸音率を確保することができる。According to the sound absorbing structure of the thirteenth invention,
In the first aspect of the invention, the surface impedance of the perforated plate with respect to the frequency of sound absorption is an impedance determined by the product of the velocity of air and the velocity of sound so that the sound absorption coefficient is 0.5 or more. Since the aperture ratio is set so as to approach, it is possible to secure the desired sound absorption coefficient.
【００５５】第１４の発明に係る吸音構造体によれば、
上記第１の発明において、吸音率が０．５以上となるよ
うに、吸音を目的とする周波数に対しての、前記多孔板
の表面インピーダンスが、空気の速度と音速との積で定
まるインピーダンスに近づくように前記開口率及び前記
空気の流れの速度を定めたので、種々の要素を考慮した
最適な吸音構造体を得ることができる。According to the sound absorbing structure of the fourteenth invention,
In the first aspect of the invention, the surface impedance of the perforated plate with respect to the frequency of sound absorption is an impedance determined by the product of the velocity of air and the velocity of sound so that the sound absorption coefficient is 0.5 or more. Since the aperture ratio and the velocity of the air flow are determined so as to approach each other, it is possible to obtain an optimum sound absorbing structure in consideration of various factors.
【００５６】第１５の発明に係る吸音構造体によれば、
上記第１の発明において、吸音率が０．５以上となるよ
うに、吸音を目的とする周波数に対しての、前記多孔板
の表面インピーダンスが、空気の密度と音速との積で定
まるインピーダンスに近づくように、前記開口率、及び
前記多孔板と前記第２の板との間の間隔を定めたので、
種々の要素を考慮した最適な吸音構造体を得ることがで
きる。According to the sound absorbing structure of the fifteenth invention,
In the first aspect of the invention, the surface impedance of the perforated plate with respect to the frequency of sound absorption is an impedance determined by the product of the density of air and the sound velocity so that the sound absorption coefficient becomes 0.5 or more. Since the aperture ratio and the distance between the perforated plate and the second plate are set so as to approach each other,
An optimal sound absorbing structure can be obtained in consideration of various factors.
【００５７】第１６の発明に係る吸音構造体によれば、
上記第１の発明において、吸音率が０．５以上となるよ
うに、吸音を目的とする周波数に対しての、前記多孔板
の表面インピーダンスが、空気の密度と音速との積で定
まるインピーダンスに近づくように、前記開口率、前記
多孔板と前記第２の板との間の間隔、及び前記空気の流
れの速度を定めたので、種々の要素を考慮した最適な吸
音構造体を得ることができる。According to the sound absorbing structure of the sixteenth invention,
In the first invention, the surface impedance of the perforated plate with respect to the frequency of sound absorption is an impedance determined by the product of the density of air and the sound velocity so that the sound absorption coefficient becomes 0.5 or more. Since the aperture ratio, the distance between the perforated plate and the second plate, and the velocity of the air flow are set so as to approach each other, it is possible to obtain an optimum sound absorbing structure in consideration of various factors. it can.
【００５８】更に、本発明に係る吸音構造体によれば、
第１の板と、第１の板と間隔（背後層）をあけて設けた
第２の板とからなり、第１の板に細孔を設け、第１の板
と第２の板との間に空気を流すようにした吸音構造体に
おいては、開口率を０．８〜３．１％、背後層を１４〜
５０ｍｍ、空気流の流速を５〜１５ｍ／ｓとすることに
より、特定の周波数である８００Ｈｚ前後の音に対し格
段の吸音効果が得られる。Furthermore, according to the sound absorbing structure of the present invention,
The first plate and the second plate spaced apart from the first plate (back layer) are provided, and the first plate is provided with pores so that the first plate and the second plate are separated from each other. In the sound absorbing structure in which air is allowed to flow between them, the aperture ratio is 0.8 to 3.1% and the back layer is 14 to
By setting the flow rate of the airflow to 50 mm and the airflow to 5 to 15 m / s, a remarkable sound absorbing effect can be obtained for the sound around a specific frequency of 800 Hz.
【図１】本発明の実施の一形態に係る吸音構造体の斜視
図である。FIG. 1 is a perspective view of a sound absorbing structure according to an embodiment of the present invention.
【図２】吸音原理を説明するための図である。FIG. 2 is a diagram for explaining the sound absorption principle.
【図３】図１に示した吸音構造体の平面に沿う断面図で
ある。FIG. 3 is a sectional view taken along the plane of the sound absorbing structure shown in FIG.
【図４】図１に示した吸音構造体の細孔にフィルムを貼
り付けた実施例の部分断面図である。4 is a partial cross-sectional view of an example in which a film is attached to the pores of the sound absorbing structure shown in FIG.
【図５】本発明の他の実施形態に係る吸音構造体の平面
に沿う断面図である。FIG. 5 is a cross-sectional view taken along the plane of a sound absorbing structure according to another embodiment of the present invention.
【図６】実施例における周波数と吸音率との関係を示す
グラフである。FIG. 6 is a graph showing the relationship between frequency and sound absorption coefficient in an example.
【図７】他の実施例における周波数と吸音率との関係を
示すグラフである。FIG. 7 is a graph showing the relationship between frequency and sound absorption coefficient in another example.
【図８】背後層、流速を変えた他の実施例における周波
数と吸音率との関係を示すグラフである。FIG. 8 is a graph showing the relationship between frequency and sound absorption coefficient in another example in which the back layer and the flow velocity are changed.
【図９】流速を変えた他の実施例における周波数と吸音
率との関係を示すグラフである。FIG. 9 is a graph showing the relationship between frequency and sound absorption coefficient in another example in which the flow velocity is changed.
【図１０】他の実施形態に係る吸音構造体の平面に沿う
断面図である。FIG. 10 is a sectional view taken along the plane of a sound absorbing structure according to another embodiment.
【図１１】更に他の実施形態に係る吸音構造体の平面に
沿う断面図である。FIG. 11 is a sectional view taken along the plane of a sound absorbing structure according to still another embodiment.
１ 板 ２ 細孔 ３ フィルム ４ 第２の板 ５ 背後層 ６ 細孔 ７ 仕切り板 1 plate 2 pores 3 film 4 second plate 5 back layer 6 pores 7 partition boards
───────────────────────────────────────────────────── フロントページの続き (72)発明者 西村 正治 兵庫県高砂市荒井町新浜二丁目１番１号 三菱重工業株式会社高砂研究所内 (72)発明者 寺西 進 兵庫県神戸市兵庫区和田崎町一丁目１番１ 号 三菱重工業株式会社神戸造船所内 (72)発明者 片山 重厚 兵庫県神戸市兵庫区和田崎町一丁目１番１ 号 三菱重工業株式会社神戸造船所内 Ｆターム(参考） 2D001 AA01 CA01 CB02 CD02 DA04 5D061 BB24 BB37 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Shoji Nishimura 2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Susumu Teranishi 1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Shigeta Katayama 1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard F term (reference) 2D001 AA01 CA01 CB02 CD02 DA04 5D061 BB24 BB37
Claims (16)
孔を設けて多孔板とすると共に、前記細孔の空間部分の
空気を振動させようとするときの抵抗、前記細孔の縁の
部分における摩擦による抵抗、前記細孔の空間部分の空
気を介して音波を放射するときの抵抗を考慮して、吸音
を目的とする周波数に対しての、前記多孔板の表面イン
ピーダンスが、空気の密度と音速との積で定まるインピ
ーダンスに近づくように、前記多孔板の表面に対する前
記細孔の開口率を定めたことを特徴とする吸音構造体。1. A plate is provided with a large number of pores at an equal pitch or an unequal pitch to form a perforated plate, and the resistance when trying to vibrate the air in the space of the pores, the edge of the pores. In consideration of the resistance due to friction in the portion of, and the resistance when sound waves are radiated through the air in the space of the pores, the surface impedance of the perforated plate with respect to the frequency of sound absorption is The sound absorbing structure is characterized in that the aperture ratio of the pores to the surface of the perforated plate is determined so as to approach an impedance determined by the product of the density and the sound velocity.
に、前記多孔板と所定の間隔をあけて第２の板を設け、
吸音を目的とする周波数に対しての、前記多孔板の表面
インピーダンスが、空気の密度と音速との積で定まるイ
ンピーダンスに近づくように、前記開口率、及び前記多
孔板と第２の板の間の間隔を定めたことを特徴とする請
求項１に記載の吸音構造体。2. A second plate is provided on the side of the perforated plate opposite to the sound source side with a predetermined distance from the perforated plate,
The aperture ratio and the distance between the porous plate and the second plate such that the surface impedance of the porous plate with respect to the frequency of sound absorption approaches the impedance determined by the product of the density of air and the speed of sound. The sound absorbing structure according to claim 1, wherein
で多数の細孔をあけたことを特徴とする請求項２に記載
の吸音構造体。3. The sound absorbing structure according to claim 2, wherein a large number of pores are formed in the second plate at equal pitches or unequal pitches.
を形成することを特徴とする請求項１に記載の吸音構造
体。4. The sound absorbing structure according to claim 1, wherein an air flow is formed on one side or both sides of the perforated plate.
の流れを形成することを特徴とする請求項２又は３に記
載の吸音構造体。5. The sound absorbing structure according to claim 2, wherein an air flow is formed between the perforated plate and the second plate.
口率を定めたことを特徴とする請求項４又は５に記載の
吸音構造体。6. The sound absorbing structure according to claim 4, wherein the opening ratio is determined in consideration of the velocity of the air flow.
孔板及び前記第２の板の双方が透明な板状材料であるこ
とを特徴とする請求項１ないし６のいずれかに記載の吸
音構造体。7. The perforated plate or the second plate or both the perforated plate and the second plate are transparent plate-shaped materials according to any one of claims 1 to 6. Sound absorbing structure.
板とほぼ直交する複数の仕切り板を設けたことを特徴と
する請求項２、３、５、６のいずれかに記載の吸音構造
体。8. A plurality of partition plates, which are substantially orthogonal to each plate, are provided between the perforated plate and the second plate, according to any one of claims 2, 3, 5, and 6. The sound absorbing structure described.
あることを特徴とする請求項８に記載の吸音構造体。9. The sound absorbing structure according to claim 8, wherein the plurality of partition plates are transparent plate-shaped materials.
前記細孔を塞ぐフィルムを設けたことを特徴とする請求
項１ないし９のいずれかに記載の吸音構造体。10. The sound absorbing structure according to claim 1, further comprising a film that closes the pores in the perforated plate or the second plate.
前記細孔の直径が前記多孔板又は前記第２の板の厚さよ
り小さいことを特徴とする請求項１ないし１０のいずれ
かに記載の吸音構造体。11. The diameter of the pores in the perforated plate or the second plate is smaller than the thickness of the perforated plate or the second plate, according to claim 1. Sound absorbing structure.
対する前記細孔の開口率を１０％以下としたことを特徴
とする請求項１又は３又は６又は７に記載の吸音構造
体。12. The sound absorbing structure according to claim 1, wherein the aperture ratio of the pores to the surface of the porous plate or the second plate is 10% or less.
音を目的とする周波数に対しての、前記多孔板の表面イ
ンピーダンスが、空気の速度と音速との積で定まるイン
ピーダンスに近づくように前記開口率を定めたことを特
徴とする請求項１に記載の吸音構造体。13. The surface impedance of the perforated plate with respect to the frequency of sound absorption is close to the impedance determined by the product of the velocity of air and the velocity of sound so that the sound absorption coefficient becomes 0.5 or more. The sound absorbing structure according to claim 1, wherein the aperture ratio is set to 1.
音を目的とする周波数に対しての、前記多孔板の表面イ
ンピーダンスが、空気の速度と音速との積で定まるイン
ピーダンスに近づくように前記開口率及び前記空気の流
れの速度を定めたことを特徴とする請求項４に記載の吸
音構造体。14. The surface impedance of the perforated plate with respect to the frequency of sound absorption is close to the impedance determined by the product of the velocity of air and the velocity of sound so that the sound absorption coefficient becomes 0.5 or more. The sound absorbing structure according to claim 4, wherein the aperture ratio and the velocity of the air flow are defined in the above.
音を目的とする周波数に対しての、前記多孔板の表面イ
ンピーダンスが、空気の密度と音速との積で定まるイン
ピーダンスに近づくように、前記開口率、及び前記多孔
板と前記第２の板との間の間隔を定めたことを特徴とす
る請求項２に記載の吸音構造体。15. The surface impedance of the perforated plate with respect to the frequency of sound absorption is close to the impedance determined by the product of the density of air and the sound velocity so that the sound absorption coefficient becomes 0.5 or more. The sound absorbing structure according to claim 2, wherein the opening ratio and the distance between the porous plate and the second plate are defined.
音を目的とする周波数に対しての、前記多孔板の表面イ
ンピーダンスが、空気の密度と音速との積で定まるイン
ピーダンスに近づくように、前記開口率、前記多孔板と
前記第２の板との間の間隔、及び前記空気の流れの速度
を定めたことを特徴とする請求項５に記載の吸音構造
体。16. The surface impedance of the perforated plate with respect to the frequency of sound absorption is close to the impedance determined by the product of the density of air and the speed of sound so that the sound absorption coefficient becomes 0.5 or more. The sound absorbing structure according to claim 5, wherein the opening ratio, the distance between the perforated plate and the second plate, and the velocity of the air flow are determined.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001230978A JP2003041528A (en) | 2001-07-31 | 2001-07-31 | Sound absorbing structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001230978A JP2003041528A (en) | 2001-07-31 | 2001-07-31 | Sound absorbing structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003041528A true JP2003041528A (en) | 2003-02-13 |
Family
ID=19063099
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001230978A Withdrawn JP2003041528A (en) | 2001-07-31 | 2001-07-31 | Sound absorbing structure |
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| Country | Link |
|---|---|
| JP (1) | JP2003041528A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007262765A (en) * | 2006-03-29 | 2007-10-11 | Yamaha Corp | Sound absorbing material and sound absorbing panel |
| JP2008064042A (en) * | 2006-09-08 | 2008-03-21 | Kyoto Univ | Noise reducing structure and method |
| CN107180132A (en) * | 2017-05-17 | 2017-09-19 | 河海大学常州校区 | A kind of Design method of structural parameters for suppressing microperforated panel nonlinear effect |
| JP2019040137A (en) * | 2017-08-28 | 2019-03-14 | 富士フイルム株式会社 | Soundproof structure, optical device, and electronic device |
| JP2019507387A (en) * | 2016-03-01 | 2019-03-14 | ガーディアン・グラス・エルエルシーＧｕａｒｄｉａｎ Ｇｌａｓｓ， Ｌｌｃ | Acoustic wall assembly with active noise disturbance characteristics and / or method of manufacture and / or use thereof |
| JP2019512727A (en) * | 2016-03-01 | 2019-05-16 | ガーディアン・グラス・エルエルシーＧｕａｒｄｉａｎ Ｇｌａｓｓ， Ｌｌｃ | Acoustic wall assembly with double wall construction and active noise interference properties, and / or method of making and / or using the same |
| KR102512257B1 (en) * | 2022-10-20 | 2023-03-20 | 권경이 | Transparent soundproofing panal for avoiding bird strike prevention apparatus |
-
2001
- 2001-07-31 JP JP2001230978A patent/JP2003041528A/en not_active Withdrawn
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007262765A (en) * | 2006-03-29 | 2007-10-11 | Yamaha Corp | Sound absorbing material and sound absorbing panel |
| JP2008064042A (en) * | 2006-09-08 | 2008-03-21 | Kyoto Univ | Noise reducing structure and method |
| JP2019507387A (en) * | 2016-03-01 | 2019-03-14 | ガーディアン・グラス・エルエルシーＧｕａｒｄｉａｎ Ｇｌａｓｓ， Ｌｌｃ | Acoustic wall assembly with active noise disturbance characteristics and / or method of manufacture and / or use thereof |
| JP2019512727A (en) * | 2016-03-01 | 2019-05-16 | ガーディアン・グラス・エルエルシーＧｕａｒｄｉａｎ Ｇｌａｓｓ， Ｌｌｃ | Acoustic wall assembly with double wall construction and active noise interference properties, and / or method of making and / or using the same |
| CN107180132A (en) * | 2017-05-17 | 2017-09-19 | 河海大学常州校区 | A kind of Design method of structural parameters for suppressing microperforated panel nonlinear effect |
| CN107180132B (en) * | 2017-05-17 | 2020-05-05 | 河海大学常州校区 | Structural parameter design method for inhibiting nonlinear effect of micro-perforated plate |
| JP2019040137A (en) * | 2017-08-28 | 2019-03-14 | 富士フイルム株式会社 | Soundproof structure, optical device, and electronic device |
| KR102512257B1 (en) * | 2022-10-20 | 2023-03-20 | 권경이 | Transparent soundproofing panal for avoiding bird strike prevention apparatus |
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Legal Events
| Date | Code | Title | Description |
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| A300 | Withdrawal of application because of no request for examination |
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