JP2000099034A - Resonator type sound absorbing device - Google Patents
Resonator type sound absorbing deviceInfo
- Publication number
- JP2000099034A JP2000099034A JP10266726A JP26672698A JP2000099034A JP 2000099034 A JP2000099034 A JP 2000099034A JP 10266726 A JP10266726 A JP 10266726A JP 26672698 A JP26672698 A JP 26672698A JP 2000099034 A JP2000099034 A JP 2000099034A
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- Japan
- Prior art keywords
- wall
- sound absorbing
- front wall
- sound
- frequency
- 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.)
- Granted
Links
Landscapes
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、音源からの音の周波数
の時間的または位置的変化に応じて共鳴周波数を変化さ
せることのできる適応吸音能力を有する共鳴器型吸音装
置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator type sound absorbing device having an adaptive sound absorbing capability capable of changing a resonance frequency according to a temporal or positional change of the frequency of a sound from a sound source.
【０００２】[0002]
【従来の技術】従来、空調ダクトや塀、壁の吸音等に
は、いわゆるヘルムホルツ共鳴器として知られた共鳴器
型吸音構造が多用されている。また、近年、騒音源の近
傍に二次音源を配置することにより騒音低減を図る、ア
クティブノイズコントロールの手法も盛んに研究されて
いる。2. Description of the Related Art Conventionally, a resonator-type sound absorbing structure known as a so-called Helmholtz resonator is frequently used for air-conditioning ducts, walls, walls and the like. In recent years, active noise control techniques for reducing noise by arranging a secondary sound source near a noise source have been actively studied.
【０００３】[0003]
【発明が解決しようとする課題】ところで、上記共鳴器
型吸音構造は、単純なメカニズムで吸音が可能な利点が
あるが、設計時に定めた共鳴周波数以外の音には対応で
きないという問題を有している。一方、上記アクティブ
ノイズコントロールの手法は、単純な形状を有する空間
における消音にはそれなりの効果を奏するものの、例え
ば、鉄道のパンタグラフ周辺や自動車等のエンジン内部
のような複雑な形状を有する空間における騒音低減に
は、未だ十分な効果を奏するに至っていない。The above-described resonator type sound absorbing structure has an advantage that sound can be absorbed by a simple mechanism, but has a problem that it cannot cope with a sound having a resonance frequency other than the resonance frequency determined at the time of design. ing. On the other hand, the above-described active noise control method has a certain effect on noise reduction in a space having a simple shape, but for example, noise in a space having a complicated shape such as around a pantograph of a railway or inside an engine of a car or the like. Sufficient effects have not yet been achieved for the reduction.
【０００４】[0004]
【課題を解決するための手段】本発明は、上述の共鳴器
型吸音装置を改良することにより、時間的または位置的
に周波数の変化する騒音にも対応可能な共鳴器型吸音装
置を提供することを目的とする。According to the present invention, there is provided a resonator type sound absorbing device which can cope with noise whose frequency changes with time or position by improving the above described resonator type sound absorbing device. The purpose is to:
【０００５】そのため、本発明の請求項１の共鳴器型吸
音装置は、前面壁と、この前面壁との間に間隔を隔てて
対向配置された剛壁と、前面壁と剛壁の周縁部同士を連
結する連結壁とからなる壁体で囲まれた空間を共鳴空間
とするとともに、上記前面壁に上記共鳴空間を外部と連
通する入口を設け、且つ上記前面壁または剛壁の少なく
とも一方を上記連結壁との間で気密を保持しながら相手
側に接近または離間する方向へ移動可能としたことを特
徴とするものである。[0005] Therefore, a resonator-type sound absorbing device according to claim 1 of the present invention has a front wall, a rigid wall opposed to the front wall at a distance from the front wall, and peripheral portions of the front wall and the rigid wall. A space surrounded by a wall body composed of a connecting wall connecting each other is defined as a resonance space, and an entrance for communicating the resonance space with the outside is provided on the front wall, and at least one of the front wall or the rigid wall is provided. It is characterized by being movable in a direction approaching or moving away from the other side while maintaining airtightness with the connection wall.
【０００６】上記の構成において、前面壁または剛壁の
少なくとも一方を相手方と接近または離間するように移
動させることにより、前面壁と剛壁間の間隔を減少また
は増加させて上記共鳴空間の容積を変化させると、それ
に応じて、上記共鳴器型吸音装置の共鳴周波数を変化さ
せることができる。[0006] In the above configuration, by moving at least one of the front wall and the rigid wall so as to approach or separate from the opponent, the distance between the front wall and the rigid wall is reduced or increased, and the volume of the resonance space is increased. When changed, the resonance frequency of the resonator type sound absorbing device can be changed accordingly.
【０００７】請求項２の共鳴器型吸音装置は、請求項１
の構成において、上記壁体内に上記前面壁及び剛壁と略
直交して上記前面壁から剛壁まで上記共鳴器型吸音装置
の厚み方向全域に渡って延びる仕切りを設けることによ
り上記共鳴器型吸音装置を複数の吸音ユニットに分割
し、各吸音ユニットに対応させて上記前面壁の入口を設
けるとともに、上記前面壁または剛壁の少なくとも一方
を各吸音ユニット毎に分割された分割体として構成し、
前面壁または剛壁の各分割体を互いに独立に移動可能と
したことを特徴とするものである。ここでは、各吸音ユ
ニット毎に上記前面壁または剛壁の分割体を移動させ、
各吸音ユニット毎の共鳴空間の容積を変化させることが
できる。According to a second aspect of the present invention, there is provided a resonator type sound absorbing device.
In the above structure, the resonator type sound absorbing device is provided by providing a partition in the wall body that extends substantially perpendicularly to the front wall and the rigid wall from the front wall to the rigid wall over the entire thickness direction of the resonator type sound absorbing device. The device is divided into a plurality of sound absorbing units, and the entrance of the front wall is provided corresponding to each sound absorbing unit, and at least one of the front wall or the rigid wall is configured as a divided body divided for each sound absorbing unit,
The front wall or the rigid wall can be moved independently of each other. Here, the divided body of the front wall or the rigid wall is moved for each sound absorbing unit,
The volume of the resonance space for each sound absorbing unit can be changed.
【０００８】請求項３の共鳴器型吸音装置は、請求項２
の構成において、音源からの音の周波数である吸音周波
数を検出する検出器を各吸音ユニット毎に設け、検出さ
れた吸音周波数に基づいて各吸音ユニット毎に共鳴周波
数が吸音周波数と一致するように上記前面壁または剛壁
の分割体を移動させる制御手段を設けたことを特徴とす
るものである。ここでは、各吸音ユニット毎に検出した
吸音周波数に基づいて各吸音ユニットの共鳴周波数を自
律的に調整するようにしている。According to a third aspect of the present invention, there is provided a resonator type sound absorbing device.
In the configuration of the above, a detector for detecting the sound absorption frequency that is the frequency of the sound from the sound source is provided for each sound absorption unit, so that the resonance frequency of each sound absorption unit matches the sound absorption frequency based on the detected sound absorption frequency. Control means for moving the divided body of the front wall or the rigid wall is provided. Here, the resonance frequency of each sound absorbing unit is autonomously adjusted based on the sound absorbing frequency detected for each sound absorbing unit.
【０００９】請求項４の共鳴器型吸音装置は、前面壁を
含む壁体で囲まれた空間を共鳴空間とするとともに、上
記前面壁に上記共鳴空間を外部と連通する入口を設け、
且つ上記壁体内に上記前面壁と略平行な隔壁を設けて上
記共鳴空間を複数に分割し、この隔壁に両側の空間を連
通する連通口を設ける一方、この連通口を開閉する開閉
手段を設けたことを特徴とするものである。According to a fourth aspect of the present invention, there is provided a resonator type sound absorbing device, wherein a space surrounded by a wall including a front wall is a resonance space, and the front wall is provided with an inlet for communicating the resonance space with the outside.
The resonance space is divided into a plurality of parts by providing a partition wall substantially parallel to the front wall in the wall body, and a communication port for communicating the spaces on both sides is provided on the partition wall, and an opening / closing means for opening and closing the communication port is provided. It is characterized by having.
【００１０】上記構成において、上記連通口が開いてい
る状態では、隔壁の両側の空間が共鳴空間となるのに対
し、上記開閉手段で連通口を閉じた状態では、隔壁を境
界として上記前面壁側の空間のみが実質的な共鳴空間と
なる。このように、開閉手段で連通口を開閉することに
より、実質的な共鳴空間の容積を変更し、共鳴周波数を
変化させることができる。In the above structure, when the communication port is open, the space on both sides of the partition wall becomes a resonance space, whereas when the communication port is closed by the opening / closing means, the front wall is bounded by the partition wall. Only the space on the side becomes a substantial resonance space. Thus, by opening and closing the communication port by the opening and closing means, it is possible to change the substantial volume of the resonance space and change the resonance frequency.
【００１１】請求項５の共鳴器型吸音装置は、請求項４
の構成において、上記壁体内に上記前面壁及び隔壁と略
直交して上記吸音ユニットの厚み方向全域に渡って延び
る仕切りを設けて上記共鳴器型吸音装置を複数の吸音ユ
ニットに分割し、各吸音ユニットに対応させて上記前面
壁の入口、上記隔壁の連通口及び該連通口を開閉する上
記開閉手段を設けたことを特徴とするものである。ここ
では、各吸音ユニット毎に開閉手段を開閉させることに
より、各吸音ユニット毎の実質的な共鳴空間の容積を変
更することができる。According to a fifth aspect of the present invention, there is provided a resonator type sound absorbing device.
In the above structure, a partition is provided in the wall body, which extends substantially perpendicularly to the front wall and the partition wall over the entire area in the thickness direction of the sound absorbing unit, and the resonator type sound absorbing device is divided into a plurality of sound absorbing units. An entrance of the front wall, a communication port of the partition, and the opening / closing means for opening and closing the communication port are provided corresponding to the unit. Here, the volume of the substantial resonance space of each sound absorbing unit can be changed by opening and closing the opening and closing means for each sound absorbing unit.
【００１２】請求項６の共鳴器型吸音装置は、請求項５
の構成において、音源からの音の周波数である吸音周波
数を検出する検出器を各吸音ユニット毎に設け、検出さ
れた吸音周波数に基づいて各吸音ユニット毎に共鳴周波
数が吸音周波数と一致するように上記開閉手段を開閉さ
せる制御手段を設けたことを特徴とするものである。こ
こでは、各吸音ユニット毎に検出した吸音周波数に基づ
いて各吸音ユニットの共鳴周波数を自律的に調整するよ
うにしている。According to a sixth aspect of the present invention, there is provided a resonator type sound absorbing apparatus.
In the configuration of the above, a detector for detecting the sound absorption frequency that is the frequency of the sound from the sound source is provided for each sound absorption unit, so that the resonance frequency of each sound absorption unit matches the sound absorption frequency based on the detected sound absorption frequency. A control means for opening and closing the opening and closing means is provided. Here, the resonance frequency of each sound absorbing unit is autonomously adjusted based on the sound absorbing frequency detected for each sound absorbing unit.
【００１３】請求項７の共鳴器型吸音装置は、請求項１
乃至６のいずれかの構成において、上記共鳴器型吸音装
置は音源の一部または全部を被覆するケース部材に取り
付けるか、またはケース部材の一部として構成すること
を特徴とするものである。According to a seventh aspect of the present invention, there is provided a resonator type sound absorbing device.
In any one of the constitutions (1) to (6), the resonator type sound absorbing device is characterized in that it is attached to a case member that covers a part or the whole of a sound source, or is configured as a part of the case member.
【００１４】[0014]
【発明の実施の形態】以下、本発明の実施の形態を図面
を参照しながら説明する。図１にヘルムホルツ共鳴器の
模式図を示す。ヘルムホルツ共鳴器１は壁体２内に共鳴
空間３を設けるとともに、壁体２に設けた入口４を介し
て上記共鳴空間３を外部と連通してなる。このヘルムホ
ルツ共鳴器１は入口４を通して共鳴空間３内に入力され
る音響エネルギーを共鳴によって熱エネルギーに変換す
ることにより吸音する。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic diagram of a Helmholtz resonator. The Helmholtz resonator 1 has a resonance space 3 provided in a wall 2 and communicates the resonance space 3 with the outside through an inlet 4 provided in the wall 2. The Helmholtz resonator 1 absorbs sound by converting acoustic energy input into the resonance space 3 through the inlet 4 into heat energy by resonance.
【００１５】上記ヘルムホルツ共鳴器１の共鳴周波数ｆ
0 は、音速をｃ、共鳴空間３の容積をＶ、入口４の径を
ｄ、入口４の深さ、つまり、入口４における壁体２の厚
みをｔとすると、次の数１の式で表される。The resonance frequency f of the Helmholtz resonator 1
0 is given by the following equation (1) , where c is the sound speed, V is the volume of the resonance space 3, V is the diameter of the inlet 4, and d is the depth of the inlet 4, that is, t is the thickness of the wall 2 at the inlet 4. expressed.
【００１６】[0016]
【数１】 (Equation 1)
【００１７】数１の式の中のａは定数で、例えば、０．
８０〜０．８５程度の値となる。数１の式から明らかな
ように、共鳴周波数ｆ0 は共鳴空間３の容積Ｖが大きく
なるに伴って小さくなる。また、入口４の径ｄが小さく
なる程共鳴周波数ｆ0 は小さくなるとともに、入口４の
深さｔが大きくなる程共鳴周波数ｆ0 は小さくなる。す
なわち、入口４のアスペクト比（ｔ／ｄ）が大きくなる
に伴って、共鳴周波数ｆ0 は小さくなる。In the equation (1), a is a constant.
The value is about 80 to 0.85. As is clear from the equation (1), the resonance frequency f 0 decreases as the volume V of the resonance space 3 increases. Further, the resonance frequency f 0 larger the diameter d of the inlet 4 is reduced along with reduced, the resonance frequency f 0 larger the depth t increases the inlet 4 is reduced. That is, as the aspect ratio (t / d) of the entrance 4 increases, the resonance frequency f 0 decreases.
【００１８】本発明は、以上の原理に基づき、 共鳴空間３の容積Ｖを可変とすることにより、ヘル
ムホルツ共鳴器１を用いた共鳴器型吸音装置の共鳴周波
数ｆ0 を変化させること、及び 入口４のアスペクト比（ｔ／ｄ）をできるだけ大き
くすることにより、従来より一層低い周波数域での吸音
をも可能とすることを目的とする。According to the present invention, the resonance frequency f 0 of the resonator type sound absorbing device using the Helmholtz resonator 1 is changed by changing the volume V of the resonance space 3 based on the above principle. It is an object of the present invention to make it possible to absorb sound in a lower frequency range than before by increasing the aspect ratio (t / d) of Aspect 4 as much as possible.
【００１９】図２及び図３に本発明の第１の実施の形態
に係る共鳴器型吸音装置を模式的に示す。この共鳴器型
吸音装置１１は前面壁１２と、この前面壁１２との間に
間隔を隔てて前面壁１２と平行に配置された剛壁１３
と、前面壁１２と剛壁１３の周縁部間で前面壁１２及び
剛壁１３と垂直な方向へ延びて前面壁１２と剛壁１３の
周縁部同士を連結する連結壁１４とを備えている。前面
壁１２、剛壁１３及び連結壁１４は壁体１５を構成す
る。剛壁１３は音を反射することのできる壁であって、
例えば、厚みが３〜４mm程度の合成樹脂板（ポリメチル
メタクリレート板等）で形成される。また、前面壁１２
も、剛壁１３と同一材料で、同程度の厚みに形成するこ
とが好ましい。FIG. 2 and FIG. 3 schematically show a resonator-type sound absorbing device according to a first embodiment of the present invention. The resonator type sound absorbing device 11 includes a front wall 12 and a rigid wall 13 arranged in parallel with the front wall 12 with a space between the front wall 12 and the front wall 12.
And a connecting wall 14 extending in a direction perpendicular to the front wall 12 and the rigid wall 13 between the peripheral edges of the front wall 12 and the rigid wall 13 and connecting the peripheral edges of the front wall 12 and the rigid wall 13 to each other. . The front wall 12, the rigid wall 13, and the connecting wall 14 constitute a wall body 15. The rigid wall 13 is a wall that can reflect sound,
For example, it is formed of a synthetic resin plate (polymethyl methacrylate plate or the like) having a thickness of about 3 to 4 mm. Also, the front wall 12
Also, it is preferable that the rigid wall 13 be formed of the same material as that of the rigid wall 13 and have the same thickness.
【００２０】ここでは、前面壁１２と剛壁１３とは円板
状を成す一方、連結壁１４は円筒状を成しており、前面
壁１２、剛壁１３及び連結壁１４で囲まれた範囲が円柱
状の共鳴空間１６を形成しているが、これに限らず、例
えば、前面壁１２と剛壁１３を矩形板状等とし、連結壁
１４を角筒状等としてもよい。In this case, the front wall 12 and the rigid wall 13 have a disc shape, while the connecting wall 14 has a cylindrical shape, and the area surrounded by the front wall 12, the rigid wall 13 and the connecting wall 14 is shown. Form a cylindrical resonance space 16, but the present invention is not limited to this. For example, the front wall 12 and the rigid wall 13 may have a rectangular plate shape, and the connecting wall 14 may have a rectangular cylindrical shape.
【００２１】前面壁１２には、上下方向及び左右方向に
各々所定の間隔を隔てて複数の入口１７を設け、前面壁
１２を多孔壁としている。また、剛壁１３の後方には、
剛壁１３と連結壁１４との間で気密を保持しながらこの
剛壁１３を前面壁１２に接近または離間する方向へ移動
させる移動手段１８を設けている。移動手段１８は、例
えば、その雄ねじ１８ａを剛壁１３側に設けた不図示の
雌ねじに回転自在に螺合してなるねじ装置と、上記雄ね
じを回転させるステップモータとからなる。The front wall 12 is provided with a plurality of entrances 17 at predetermined intervals in the vertical and horizontal directions, respectively, and the front wall 12 is a porous wall. Also, behind the rigid wall 13,
Moving means 18 is provided for moving the rigid wall 13 in a direction to approach or separate from the front wall 12 while maintaining airtightness between the rigid wall 13 and the connecting wall 14. The moving means 18 includes, for example, a screw device rotatably screwing the male screw 18a to a female screw (not shown) provided on the rigid wall 13 side, and a step motor for rotating the male screw.
【００２２】上記共鳴器型吸音装置１１は、図１のヘル
ムホルツ共鳴器１を上下方向及び左右方向に各々複数個
アレイ状に配列したものであり、個々の入口１７に対応
する各吸音部１１ａ（図３中便宜上点線で区画した１ブ
ロック）が各々ヘルムホルツ共鳴器１を成すものと考え
ることができる。従って、共鳴空間１６全体の容積を吸
音部１１ａの個数で除した、個々の吸音部１１ａ毎の共
鳴空間の容積をＶ、各入口１７の径及び深さを各々ｄ及
びｔとすると、各吸音部１１ａについて大略前記の数１
の式の関係が成立する。なお、図２、図３に示す装置で
は、実際には、隣接する吸音部１１ａ間に仕切りは設け
ていない。The above-described resonator type sound absorbing device 11 is one in which a plurality of Helmholtz resonators 1 of FIG. 1 are arranged in an array in the vertical and horizontal directions, respectively, and each sound absorbing portion 11 a ( For convenience, one block defined by a dotted line in FIG. 3) can be considered to constitute the Helmholtz resonator 1. Accordingly, when the volume of the resonance space for each individual sound absorbing portion 11a is V and the diameter and depth of each inlet 17 are d and t, respectively, the total volume of the resonance space 16 is divided by the number of the sound absorbing portions 11a. About the part 11a, the above equation 1
The following relationship holds. In addition, in the apparatus shown in FIGS. 2 and 3, no partition is actually provided between the adjacent sound absorbing portions 11a.
【００２３】上記移動手段１８で図２の仮想線の如く剛
壁１３を前面壁１２に接近または離間する方向へ移動さ
せ、共鳴空間１６の容積を増減させると、それに応じて
各吸音部１１ａに対応する容積Ｖも変化し、共鳴器型吸
音装置１１の共鳴周波数ｆ0が変化することになる。本
共鳴器型吸音装置１１は、不図示の音源からの音の周波
数である吸音周波数の時間的変化及び位置的変化が比較
的少ない環境での使用に適したものであって、例えば、
不図示の検出器で定期的に吸音周波数を検出し、吸音周
波数の変動に応じて、適宜剛壁１３を移動させることに
より、共鳴器型吸音装置１１の共鳴周波数ｆ0 をその時
点での吸音周波数と合致させるように制御すればよい。
なお、上記の実施の形態では、剛壁１３を移動させるこ
とにより共鳴周波数を変化させるようにしたが、これに
代えて、前面壁１２を移動させたり、或いは前面壁１２
及び剛壁１３の双方を移動させるようにしてもよい。When the rigid wall 13 is moved toward or away from the front wall 12 as shown by the imaginary line in FIG. 2 by the moving means 18, and the volume of the resonance space 16 is increased or decreased, the sound absorbing portions 11a are correspondingly moved. The corresponding volume V also changes, and the resonance frequency f 0 of the resonator type sound absorbing device 11 changes. The present resonator-type sound absorbing device 11 is suitable for use in an environment in which a temporal change and a positional change of a sound absorbing frequency, which is a frequency of a sound from a sound source (not shown), are relatively small.
The sound absorption frequency is periodically detected by a detector (not shown), and the rigid wall 13 is appropriately moved in accordance with the fluctuation of the sound absorption frequency, so that the resonance frequency f 0 of the resonator type sound absorption device 11 is changed to the sound absorption at that time. What is necessary is just to control so that it may match with a frequency.
In the above embodiment, the resonance frequency is changed by moving the rigid wall 13, but instead the front wall 12 may be moved or the front wall 12 may be moved.
Alternatively, both the rigid wall 13 and the rigid wall 13 may be moved.
【００２４】以下、上記共鳴器型吸音装置１１を含む実
験装置を用いて、剛壁１３の移動、つまり、共鳴空間１
６の容積の変化に伴う共鳴周波数ｆ0 の変化を実際に測
定した結果を説明する。図４に示すように、この実験装
置２１は円筒状の音響管２２の一端部近傍に上記共鳴器
型吸音装置１１を設けてなり、実験装置２１の一端部近
傍が前記連結壁１４を構成している。音響管２２の他端
部には、音源としてのスピーカ２３を配置するととも
に、音響管２２内に挿入されたマイクロフォン２４を検
出装置２５に接続している。Hereinafter, the movement of the rigid wall 13, that is, the resonance space 1, will be described using an experimental device including the resonator type sound absorbing device 11.
The result of the actual measurement of the change in the resonance frequency f 0 accompanying the change in the volume of No. 6 will be described. As shown in FIG. 4, the experimental device 21 is provided with the resonator type sound absorbing device 11 near one end of a cylindrical acoustic tube 22, and the connecting wall 14 is formed near one end of the experimental device 21. ing. A speaker 23 as a sound source is arranged at the other end of the acoustic tube 22, and a microphone 24 inserted into the acoustic tube 22 is connected to the detection device 25.
【００２５】ここでは、垂直入射吸音率α0 を測定する
ことにより、上記の共鳴周波数ｆ0を求めた。すなわ
ち、スピーカ２３で正弦波状の音波が発生され、これが
音響管２２内を共鳴器型吸音装置１１側へ伝搬される
と、入力波と反射波の干渉により定在波が発生する。な
お、定在波比ｎはマイクロフォン２４で音圧を測定する
ことにより求めることができる。Here, the above-mentioned resonance frequency f 0 was obtained by measuring the normal incidence sound absorption coefficient α 0 . That is, when a sine-wave sound wave is generated by the speaker 23 and propagated through the acoustic tube 22 toward the resonator-type sound absorbing device 11, a standing wave is generated due to interference between the input wave and the reflected wave. The standing wave ratio n can be obtained by measuring the sound pressure with the microphone 24.
【００２６】共鳴器型吸音装置１１の音響反射係数をＲ
とすると、Ｒは定在波比ｎから求めることができるの
で、垂直入射吸音率α0 は次の数２の式により表され
る。The acoustic reflection coefficient of the resonator type sound absorbing device 11 is R
Then, since R can be obtained from the standing wave ratio n, the normal incidence sound absorption coefficient α 0 is expressed by the following equation (2).
【００２７】[0027]
【数２】 従って、マイクロフォン２４からの音の周波数を変化さ
せながら定在波比ｎの変化を追跡することにより、音源
からの音の周波数と垂直入射吸音率α0 との関係を知る
ことができ、且つ共鳴器型吸音装置１１の共鳴周波数ｆ
0 は垂直入射吸音率α0 が最大となる周波数として求め
ることができる。(Equation 2) Therefore, by tracking the change in the standing wave ratio n while changing the frequency of the sound from the microphone 24, it is possible to know the relationship between the frequency of the sound from the sound source and the normal incidence sound absorption coefficient α 0 , and Frequency f of the sound absorber 11
0 can be obtained as the frequency at which the normal incidence sound absorption coefficient α 0 becomes maximum.
【００２８】次に、前面壁１２と剛壁１３間のギャップ
寸法、つまり、共鳴空間１６の容積を複数通りに変化さ
せながら、上記の原理で共鳴器型吸音装置１１の共鳴周
波数ｆ0 を求めた結果を図５に示す。横軸はスピーカ２
３からの音の周波数、縦軸は垂直入射吸音率α0 であ
り、ここでは、前面壁１２と剛壁１３間のギャップを６
mm、８mm、１０mm、１２mm（各々曲線Ｉ乃至IV）の４通
りに変化させた。各々の場合の共鳴周波数ｆ0 、つま
り、垂直入射吸音率α0 のピーク値は、ギャップ、つま
り、共鳴空間１６の容積が大きくなるに伴って小さくな
っている。Next, while changing the gap size between the front wall 12 and the rigid wall 13, that is, the volume of the resonance space 16 in a plurality of ways, the resonance frequency f 0 of the resonator type sound absorbing device 11 is obtained according to the above principle. The results are shown in FIG. The horizontal axis is speaker 2
3, the vertical axis is the normal incidence sound absorption coefficient α 0 , and here, the gap between the front wall 12 and the rigid wall 13 is 6
mm, 8 mm, 10 mm, and 12 mm (curves I to IV, respectively). In each case, the resonance frequency f 0 , that is, the peak value of the normal incidence sound absorption coefficient α 0 , decreases as the gap, that is, the volume of the resonance space 16 increases.
【００２９】図６に本発明の第２の実施の形態を示す。
この実施の形態の共鳴器型吸音装置１１は、上記第１の
実施の形態の共鳴器型吸音装置１１の壁体１５内に、前
面壁１２及び剛壁１３と直交して前面壁１２から剛壁１
３まで共鳴器型吸音装置１１の厚み方向全域に渡って延
びる仕切り２６を設け、共鳴空間１６を複数に分割する
ことにより、共鳴器型吸音装置１１を複数の吸音ユニッ
ト１１ｂに分割している。ここでは、各吸音ユニット１
１ｂに対応して前面壁１２に複数の入口１７を備え、各
吸音ユニット１１ｂが複数の吸音部１１ａからなる。FIG. 6 shows a second embodiment of the present invention.
The resonator-type sound absorbing device 11 of this embodiment is rigidly mounted on the wall 15 of the resonator-type sound absorbing device 11 of the first embodiment from the front wall 12 at right angles to the front wall 12 and the rigid wall 13. Wall 1
By providing a partition 26 extending over the entire thickness direction of the resonator type sound absorbing device 11 up to 3 and dividing the resonance space 16 into a plurality, the resonator type sound absorbing device 11 is divided into a plurality of sound absorbing units 11b. Here, each sound absorbing unit 1
A plurality of entrances 17 are provided in the front wall 12 corresponding to 1b, and each sound absorbing unit 11b includes a plurality of sound absorbing portions 11a.
【００３０】また、剛壁１３は各吸音ユニット１１ｂ毎
に複数の分割体１３ａに分割し、個々の分割体１３ａを
連結壁１４または仕切り２６との間の気密を保持しなが
ら前面壁１２と接近または離間する方向へ移動させる移
動手段１８を各分割体１３ａ毎に独立に設けている。さ
らに、各入口１７に対応して音源からの音の周波数であ
る吸音周波数を検出する検出器２７を剛壁１３に埋め込
み形式等で設ける一方、検出器２７で検出される吸音周
波数に応じて移動手段１８の駆動制御を行い、当該吸音
ユニット１１ｂの共鳴周波数が上記吸音周波数と一致す
るように各分割体１３ａを移動させる制御手段２８を設
けている。The rigid wall 13 is divided into a plurality of divided bodies 13a for each sound absorbing unit 11b, and each divided body 13a approaches the front wall 12 while maintaining the airtightness between the connecting wall 14 and the partition 26. Alternatively, the moving means 18 for moving in the separating direction is provided independently for each divided body 13a. Further, a detector 27 for detecting the sound absorption frequency, which is the frequency of the sound from the sound source, is provided in the rigid wall 13 in an embedded manner or the like corresponding to each of the entrances 17, and moves in accordance with the sound absorption frequency detected by the detector 27. There is provided a control means 28 for controlling the driving of the means 18 and moving each of the divided bodies 13a such that the resonance frequency of the sound absorbing unit 11b matches the sound absorbing frequency.
【００３１】上記構成において、第２の実施の形態の共
鳴器型吸音装置１１は、例えば、吸音周波数が位置的に
変化する場合でも、個々の吸音ユニット１１ｂにおける
吸音周波数を検出器２７で検出し、検出結果に応じて制
御手段２８で各移動装置１８を介して剛壁１３の分割体
１３ａを移動させることにより、各吸音ユニット１１ｂ
の共鳴周波数が各々当該吸音ユニット１１ｂの位置にお
ける吸音周波数と一致するように制御するものである。In the above configuration, the resonator-type sound absorbing device 11 of the second embodiment detects the sound absorbing frequency of each sound absorbing unit 11b with the detector 27 even if the sound absorbing frequency changes in position. By moving the divided body 13a of the rigid wall 13 by the control means 28 via each moving device 18 according to the detection result, each sound absorbing unit 11b
Are controlled so that the resonance frequencies of the respective sound absorption units 11b coincide with the sound absorption frequency at the position of the sound absorption unit 11b.
【００３２】なお、各吸音ユニット１１ｂ毎に複数の検
出器２７を設けたが、これは個々の吸音ユニット１１ｂ
内で吸音周波数の分布が存在する場合に、各吸音ユニッ
ト１１ｂの共鳴周波数を最適な値とするためには、各吸
音ユニット１１ｂの複数箇所で吸音周波数を検出するこ
とが好ましいためである。但し、各吸音ユニット１１ｂ
が十分に小さい場合、各吸音ユニット１１ｂ毎に一つの
検出器２７を設けるのみでもよい。A plurality of detectors 27 are provided for each sound absorbing unit 11b.
This is because it is preferable to detect the sound absorption frequency at a plurality of locations of each sound absorption unit 11b in order to make the resonance frequency of each sound absorption unit 11b an optimum value when the distribution of the sound absorption frequency exists within the sound absorption units. However, each sound absorbing unit 11b
Is sufficiently small, only one detector 27 may be provided for each sound absorbing unit 11b.
【００３３】また、この第２の実施の形態では、剛壁１
３を各吸音ユニット１１ｂ毎の分割体１３ａに分割し
て、各分割体１３ａを互いに独立に移動させるようにし
たが、前面壁１２を各吸音ユニット１１ｂ毎の分割体に
分割して、各分割体を移動させるようにしてもよい。In the second embodiment, the rigid wall 1
3 is divided into divided bodies 13a for each of the sound absorbing units 11b, and the divided bodies 13a are moved independently of each other. However, the front wall 12 is divided into divided bodies for each of the sound absorbing units 11b. The body may be moved.
【００３４】ところで、共鳴器型吸音装置１１で低い周
波数域の騒音を吸収するためには、前記数１の式から明
らかなように、入口１７の径ｄを小さくする一方、入口
１７の深さｔを大きくしてアスペクト比（ｔ／ｄ）を大
きくする必要がある。しかしながら、深さｔを大きくす
ると、前面壁１２の厚みが増して、共鳴器型吸音装置１
１のサイズ全体が大型化する。従って、深さｔをある一
定限度以下としてアスペクト比（ｔ／ｄ）を大きくする
ためには、入口１７の径ｄをできるだけ小さく、例え
ば、数１０μｍ乃至１００μｍ程度以下とすることが好
ましい。In order for the resonator type sound absorbing device 11 to absorb noise in a low frequency range, the diameter d of the inlet 17 is reduced while the depth of the inlet 17 is reduced, as is apparent from the equation (1). It is necessary to increase t to increase the aspect ratio (t / d). However, when the depth t is increased, the thickness of the front wall 12 increases, and the resonator type sound absorbing device 1
The overall size of 1 increases. Therefore, in order to increase the aspect ratio (t / d) by setting the depth t to a certain limit or less, it is preferable that the diameter d of the inlet 17 be as small as possible, for example, about several tens μm to 100 μm or less.
【００３５】なお、上述のように剛壁１３の移動等によ
って共鳴空間１６の容積を減少させることにより、共鳴
周波数ｆ0 を増加させて高い周波数域にも対応させるこ
とが可能であるので、入口１７の径ｄを小さくして低周
波数域に対応可能とすることにより、結果的に共鳴器型
吸音装置１１で対応可能な音の周波数範囲を拡張するこ
とができる。また、入口１７の径ｄが小さくなるに伴っ
て、吸音周波数の位置的変化によりきめ細かく対応する
ことが可能となるので、この面からも入口１７の径ｄを
できるだけ小さくすることが好ましい。As described above, by reducing the volume of the resonance space 16 by moving the rigid wall 13 or the like, the resonance frequency f 0 can be increased to cope with a high frequency range. By making the diameter d of 17 smaller and making it possible to cope with a low frequency range, the frequency range of sound that can be coped with by the resonator type sound absorbing device 11 can be expanded as a result. Further, as the diameter d of the inlet 17 becomes smaller, it is possible to respond more finely to the positional change of the sound absorption frequency. Therefore, it is preferable to make the diameter d of the inlet 17 as small as possible.
【００３６】ここで、厚みｔができるだけ小さい前面壁
１２に径ｄの小さい入口１７を形成するためには、例え
ば、シンクロトロン放射光源（以下、ＳＲ光源という）
を用いたＸ線リソグラフィ法を用いることが好ましい。
すなわち、図７に示すように、小型のＳＲ光源３１（例
えば、０．６ＧｅＶ程度のエネルギーを有し、放射スペ
クトルが１．５ｎｍ程度のピーク波長を有するととも
に、スポットサイズが３０mm×５mm程度のもの）から多
数の孔３２ａを有するＸ線マスク３２を介して、前面壁
１２の材料であるポリメチルメタクリレート板３３（以
下、ＰＭＭＡ板３３）にＳＲ光を照射した後、所定の現
像剤で、例えば、数時間程度上記ＰＭＭＡ板３３を現像
すると、図８に示すように、Ｘ線マスク３２の孔３２ａ
を介してＳＲ光が照射された部位でＰＭＭＡ板３３に孔
３３ａが形成される。このＰＭＭＡ板３３を前面壁１２
として用いることができる（孔３３ａが入口１７とな
る）。Here, in order to form an entrance 17 having a small diameter d in the front wall 12 having a thickness t as small as possible, for example, a synchrotron radiation light source (hereinafter, referred to as an SR light source)
It is preferable to use an X-ray lithography method using
That is, as shown in FIG. 7, a small SR light source 31 (for example, having an energy of about 0.6 GeV, a radiation spectrum having a peak wavelength of about 1.5 nm, and a spot size of about 30 mm × 5 mm) ), Through a X-ray mask 32 having a large number of holes 32a, a polymethyl methacrylate plate 33 (hereinafter, PMMA plate 33), which is a material of the front wall 12, is irradiated with SR light, and then is irradiated with a predetermined developer, for example. After developing the PMMA plate 33 for about several hours, as shown in FIG.
A hole 33a is formed in the PMMA plate 33 at a position irradiated with the SR light via the. This PMMA plate 33 is attached to the front wall 12.
(The hole 33a becomes the inlet 17).
【００３７】上記Ｘ線マスク３２としては、例えば、直
径が数１０μｍ乃至１００μｍ以下程度の孔３２ａを有
し、厚みが１００乃至２００μｍ程度の銅板その他の金
属板等を用いることができ、これにより、ＰＭＭＡ板３
３に直径数１０μｍ乃至１００μｍ以下程度の孔３３ａ
を多数形成することができる。ＰＭＭＡ板３３の厚み
は、例えば、３乃至４mm以下程度とし、孔３３ａのアス
ペクト比は、孔３３ａの径に応じて１０乃至１００程度
とすることができる。そして、本発明では孔３３ａのア
スペクト比を最大で１００程度とすることにより、２０
０乃至３００Ｈｚ程度の低周波数域の騒音の吸収が可能
となる。As the X-ray mask 32, for example, a copper plate or other metal plate having a hole 32a having a diameter of about several tens μm to 100 μm and a thickness of about 100 to 200 μm can be used. PMMA plate 3
3, a hole 33a having a diameter of about 10 μm to 100 μm or less.
Can be formed in large numbers. The thickness of the PMMA plate 33 is, for example, about 3 to 4 mm or less, and the aspect ratio of the hole 33a can be about 10 to 100, depending on the diameter of the hole 33a. In the present invention, by setting the aspect ratio of the hole 33a to about 100 at the maximum,
It becomes possible to absorb noise in a low frequency range of about 0 to 300 Hz.
【００３８】図９に本発明の第３の実施の形態を示す。
この実施の形態の共鳴器型吸音装置４１は、例えば、と
もに円板状を成す前面壁４２と剛壁４３との周縁部同士
を円筒状の連結壁４４で連結することにより、これら前
面壁４２、剛壁４３及び連結壁４４からなる壁体４５で
囲まれた円柱状の空間を共鳴空間４６としている。ま
た、共鳴空間４６内の前面壁４２と剛壁４３との間に円
板状の隔壁４７を設け、共鳴空間４６を前面壁４２と隔
壁４７間の第１空間４８と、隔壁４７と剛壁４３間の第
２空間４９とに区画している。ここで、前面壁４２及び
剛壁４３は第１の実施の形態と同様に、例えば、厚みが
３乃至４mm程度の合成樹脂板で形成することができ、ま
た、隔壁４７は、例えば、厚みが０．５mm程度のＳｉ板
で形成することができる。FIG. 9 shows a third embodiment of the present invention.
The resonator-type sound absorbing device 41 of this embodiment is configured such that, for example, the peripheral portions of a front wall 42 and a rigid wall 43, both of which have a disc shape, are connected to each other by a cylindrical connecting wall 44, so that these front walls 42 A cylindrical space surrounded by a wall body 45 including a rigid wall 43 and a connecting wall 44 is defined as a resonance space 46. Further, a disk-shaped partition wall 47 is provided between the front wall 42 and the rigid wall 43 in the resonance space 46, and the resonance space 46 is divided into a first space 48 between the front wall 42 and the partition wall 47, and the partition wall 47 and the rigid wall. The space 43 is divided into a second space 49. Here, the front wall 42 and the rigid wall 43 can be formed of, for example, a synthetic resin plate having a thickness of about 3 to 4 mm, as in the first embodiment. It can be formed of a Si plate of about 0.5 mm.
【００３９】前面壁４２には複数の入口５０を形成する
一方、隔壁４７には複数の連通孔５１を形成し、且つ各
連通孔５１を開閉する複数の小型の開閉アクチュエータ
５２（開閉手段）を設けている。図１０に示すように、
開閉アクチュエータ５２は金属層５２ａを図示しない２
つのポリイミド層（絶縁層）で上下からサンドイッチ状
に挟み込んで３層で構成し、基板としての役割を有する
隔壁４７上に配置している。なお、この実施の形態で
は、隔壁４７上に絶縁層４７ａを形成しているが、絶縁
層４７ａは必ずしも設ける必要はない。A plurality of entrances 50 are formed in the front wall 42, a plurality of communication holes 51 are formed in the partition wall 47, and a plurality of small opening / closing actuators 52 (opening / closing means) for opening and closing the communication holes 51 are provided. Provided. As shown in FIG.
The opening / closing actuator 52 includes a metal layer 52a (not shown).
It is composed of three layers sandwiched between two polyimide layers (insulating layers) in a sandwich shape from above and below, and is arranged on a partition wall 47 serving as a substrate. In this embodiment, the insulating layer 47a is formed over the partition wall 47; however, the insulating layer 47a is not necessarily provided.
【００４０】上記３層構造の開閉アクチュエータ５２は
隔壁４７上に固着される大略Ｔ字状の基部５３と、屈曲
部５４を介して基部５３と連結される長尺の開閉弁部５
５からなり、開閉弁部５５は予めカーリング加工で湾曲
形成している。これにより、常時、つまり、スイッチ５
６がオフの非通電時には図１０の実線の如く開閉弁部５
５が湾曲し、連通孔５１を開放している。一方、スイッ
チ５６をオンとし、電源５７により隔壁４７と開閉アク
チュエータ５２の金属層５２ａとの間に通電すると、図
１０の仮想線の如く開閉弁部５５が隔壁４７に吸着され
て略直線状となり、連通孔５１を閉じるようになってい
る。なお、この実施の形態では、隔壁４７自体を開閉ア
クチュエータ５２の対向電極層として用いたが、対向電
極層を隔壁４７と別途に隔壁４７上に積層するようにし
てもよい。The opening / closing actuator 52 having the three-layer structure has a substantially T-shaped base 53 fixed on a partition 47 and a long opening / closing valve 5 connected to the base 53 through a bent portion 54.
The on-off valve portion 55 is formed in a curved shape by curling in advance. Thereby, at all times, that is, the switch 5
When the switch 6 is turned off and not energized, the on-off valve unit 5 is turned on as shown by the solid line in FIG.
5 is curved to open the communication hole 51. On the other hand, when the switch 56 is turned on and power is supplied between the partition 47 and the metal layer 52a of the opening / closing actuator 52 by the power supply 57, the opening / closing valve portion 55 is adsorbed by the partition 47 as shown by a virtual line in FIG. , The communication hole 51 is closed. In this embodiment, the partition 47 itself is used as a counter electrode layer of the opening / closing actuator 52, but the counter electrode layer may be laminated on the partition 47 separately from the partition 47.
【００４１】上記共鳴器型吸音装置４１において、各開
閉アクチュエータ５２を開いて第１及び第２空間４８、
４９を連通状態とすると、第１及び第２空間４８、４９
が実質的な共鳴空間となり、共鳴器型吸音装置４１の共
鳴周波数ｆ0 は比較的小さな値となる。一方、各開閉ア
クチュエータ５２を閉じて第１空間４８と第２空間４９
とを遮断すると、第１空間４８のみが実質的な共鳴空間
となり、共鳴空間の容積が減少するので、共鳴器型吸音
装置４１の共鳴周波数ｆ0 は開閉アクチュエータ５２の
開時よりも大きな値となる。このように、本実施の形態
では、開閉アクチュエータ５２で連通孔５１を開閉する
ことにより、共鳴器型吸音装置４１の共鳴周波数ｆ0 を
変化させることができる。In the above-described resonator type sound absorbing device 41, each opening / closing actuator 52 is opened to open the first and second spaces 48,
Assuming that the first and second spaces 49 and 49 are in communication, the first and second spaces 48 and 49
Becomes a substantial resonance space, and the resonance frequency f 0 of the resonator type sound absorbing device 41 has a relatively small value. On the other hand, each opening / closing actuator 52 is closed to close the first space 48 and the second space 49.
Is cut off, only the first space 48 becomes a substantial resonance space, and the volume of the resonance space is reduced. Therefore, the resonance frequency f 0 of the resonator type sound absorbing device 41 is set to a value larger than when the opening / closing actuator 52 is opened. Become. As described above, in the present embodiment, the resonance frequency f 0 of the resonator type sound absorbing device 41 can be changed by opening and closing the communication hole 51 with the opening and closing actuator 52.
【００４２】次に、共鳴器型吸音装置４１において、開
閉アクチュエータ５２で連通孔５１を開閉した場合の共
鳴周波数の変化を測定した実験結果を示す。この実験で
は、厚み１mmのＰＭＭＡ板からなる前面壁４２に４００
個の径１００μｍの入口５０を設ける一方、厚み１mmの
ＰＭＭＡ板からなる隔壁４７に２５個の径１mmの連通孔
５１を形成するとともに、各連通孔５１に対応して各々
開閉アクチュエータ５２を設け、これら２５個の連通孔
５１を各開閉アクチュエータ５２で全て閉じた場合と全
て開いた場合との各々について、図４の実験装置と同様
の方法で吸音周波数を変化させながら、吸音周波数と垂
直入射吸音率α0 との関係を測定した。Next, an experimental result of measuring a change in resonance frequency when the communication hole 51 is opened and closed by the opening and closing actuator 52 in the resonator type sound absorbing device 41 is shown. In this experiment, 400 mm was applied to the front wall 42 made of a 1 mm thick PMMA plate.
In addition to providing the inlet 50 having a diameter of 100 μm, the partition 47 made of a PMMA plate having a thickness of 1 mm is provided with 25 communication holes 51 having a diameter of 1 mm, and an opening / closing actuator 52 is provided corresponding to each communication hole 51. The sound absorption frequency and the normal incidence sound absorption were changed by changing the sound absorption frequency in the same manner as in the experimental apparatus of FIG. The relationship with the rate α 0 was measured.
【００４３】図１１の横軸は吸音周波数、縦軸は垂直入
射吸音率α0 であり、前述のように、垂直入射吸音率α
0 のピークが共鳴周波数である。図１１中曲線Ｉは開閉
アクチュエータ５２で連通孔５１を閉じた場合の特性、
曲線IIは連通孔５１を開いた場合の特性であり、連通孔
５１を開いた場合は共鳴周波数がより低くなることが分
かる。In FIG. 11, the horizontal axis represents the sound absorption frequency, and the vertical axis represents the normal incidence sound absorption coefficient α 0 , as described above.
The peak at 0 is the resonance frequency. A curve I in FIG. 11 indicates a characteristic when the communication hole 51 is closed by the opening / closing actuator 52,
Curve II shows the characteristics when the communication hole 51 is opened, and it can be seen that the resonance frequency becomes lower when the communication hole 51 is opened.
【００４４】図１２に第４の実施の形態を示す。この実
施の形態では、第３の実施の形態の共鳴器型吸音装置４
１における壁体４５内に前面壁４２及び隔壁４７と直交
して共鳴器型吸音装置４１の厚み方向の全域に渡って延
びる仕切り５８を設け、共鳴器型吸音装置４１を複数の
吸音ユニット４１ａに分割している。そして、各吸音ユ
ニット４１ａ毎に前面壁４２に１または複数の入口５０
を設け、隔壁４７に１または複数の連通孔５１を設ける
とともに、各連通孔５１を開閉する開閉アクチュエータ
５２を設けている。FIG. 12 shows a fourth embodiment. In this embodiment, the resonator type sound absorbing device 4 of the third embodiment is used.
In the wall 45 of FIG. 1, a partition 58 is provided which extends perpendicularly to the front wall 42 and the partition wall 47 and extends over the entire area in the thickness direction of the resonator type sound absorbing device 41, and the resonator type sound absorbing device 41 is provided to a plurality of sound absorbing units 41a. Divided. Then, one or a plurality of inlets 50 are provided in the front wall 42 for each sound absorbing unit 41a.
The partition wall 47 is provided with one or a plurality of communication holes 51, and an opening / closing actuator 52 for opening and closing each communication hole 51 is provided.
【００４５】また、各吸音ユニット４１ａに対応させて
前面壁４２等に吸音周波数を検出するための１または複
数の検出器５８を設けるとともに、これらの検出器５８
の検出結果に応じて、各吸音ユニット４１ａの開閉アク
チュエータ５２を開閉駆動し、各吸音ユニット４１ａの
共鳴周波数が当該吸音ユニット４１ａの位置における吸
音周波数と一致するように制御する制御手段６０を設置
している。この実施の形態によれば、吸音周波数が位置
的に変化する場合でも、個々の吸音ユニット４１ａ毎に
共鳴周波数を個別に制御できるとともに、この共鳴周波
数の制御を検出器５８の検出結果に基づいて自律的に行
える利点がある。In addition, one or a plurality of detectors 58 for detecting the sound absorption frequency are provided on the front wall 42 or the like corresponding to each sound absorbing unit 41a, and these detectors 58 are provided.
In response to the detection result, a control means 60 is provided for opening and closing the opening / closing actuator 52 of each sound absorbing unit 41a and controlling the resonance frequency of each sound absorbing unit 41a so as to match the sound absorbing frequency at the position of the sound absorbing unit 41a. ing. According to this embodiment, even when the sound absorption frequency changes in position, the resonance frequency can be individually controlled for each sound absorption unit 41a, and the control of the resonance frequency is performed based on the detection result of the detector 58. It has the advantage of being autonomous.
【００４６】なお、上記第３及び第４の実施の形態の共
鳴器型吸音装置４１では、隔壁４７を一つのみ設けて共
鳴周波数ｆ0 を２段階に変化させるようにしたが、隔壁
４７を２つ以上設けて共鳴空間４６を３つ以上の空間に
区画し、且つ個々の隔壁４７の連通孔５１に各々開閉ア
クチュエータ５２を設けることにより、共鳴周波数ｆ 0
を３段階以上に変化させることも可能である。また、開
閉アクチュエータ５２としては、上記した開閉弁部５５
を湾曲状または直線状に変形させるものの他に、例え
ば、スライド式のもの等、種々の形式の開閉アクチュエ
ータを用いることができる。It should be noted that the third and fourth embodiments are common.
In the sound absorber type sound absorbing device 41, only one partition wall 47 is provided and shared.
Sound frequency f0Was changed in two steps,
Provide two or more 47 and make the resonance space 46 into three or more spaces
The partition walls 47 are individually opened and closed in the communication holes 51 of the individual partition walls 47.
By providing the actuator 52, the resonance frequency f 0
Can be changed in three or more steps. Also open
As the closing actuator 52, the above-described on-off valve portion 55
In addition to those that deform a curved or linear shape,
Various types of opening and closing actuators, such as sliding type
Data can be used.
【００４７】上記各実施の形態の共鳴器型吸音装置１
１、４１は、具体的には、例えば、図１３に示すように
自動車のエンジンルーム６１（ケース部材）内の側壁６
１ａや蓋体６１ｂの裏面等に設置したり、図１４に示す
ように、タービン６２やファン６３等を有する航空機用
のターボプロットエンジン６４のケース部材６５等に設
置することができる。また、これらの各種エンジン等の
ケース部材自体の一部を共鳴器型吸音装置１１、４１で
構成することも可能である。The resonator type sound absorbing device 1 of each of the above embodiments.
Specifically, for example, the side walls 6 in the engine room 61 (case member) of the automobile as shown in FIG.
1a or the back surface of the lid 61b, or as shown in FIG. 14, a case member 65 of an aircraft turboplot engine 64 having a turbine 62, a fan 63, and the like. Also, a part of the case member itself of these various engines and the like can be constituted by the resonator type sound absorbing devices 11 and 41.
【００４８】[0048]
【発明の効果】請求項１の共鳴器型吸音装置は、前面壁
と、この前面壁との間に間隔を隔てて対向配置された剛
壁と、前面壁と剛壁の周縁部同士を連結する連結壁とか
らなる壁体で囲まれた空間を共鳴空間とするとともに、
上記前面壁に上記共鳴空間を外部と連通する入口を設
け、且つ上記前面壁または剛壁の少なくとも一方を上記
連結壁との間で気密を保持しながら相手側に接近または
離間する方向へ移動可能としたものであり、上記前面壁
または剛壁の少なくとも一方を移動させて前面壁と剛壁
間の間隔を増減させ、上記共鳴空間の容積を変化させる
ことによって、上記共鳴器型吸音装置の共鳴周波数を変
化させることができるので、例えば、音源からの音の周
波数である吸音周波数が時間的に変化するような場合で
も、共鳴器型吸音装置の共鳴周波数をそれに合わせて変
化させることにより、適応吸音処理を実現することが可
能となる。According to the first aspect of the present invention, there is provided a resonator type sound absorbing device in which a front wall, a rigid wall opposed to the front wall at a distance from the front wall, and peripheral edges of the front wall and the rigid wall are connected. The space surrounded by the wall consisting of the connecting wall that makes
The front wall is provided with an entrance for communicating the resonance space with the outside, and at least one of the front wall and the rigid wall can be moved in a direction approaching or separating from the other side while maintaining airtightness with the connection wall. By moving at least one of the front wall or the rigid wall to increase or decrease the distance between the front wall and the rigid wall, and changing the volume of the resonance space, the resonance of the resonator type sound absorbing device is improved. Since the frequency can be changed, for example, even when the sound absorption frequency, which is the frequency of the sound from the sound source, changes with time, the resonance frequency of the resonator-type sound absorption device is changed in accordance with the change, so that it can be adapted. Sound absorption processing can be realized.
【００４９】請求項２の共鳴器型吸音装置は、上記壁体
内に上記前面壁及び剛壁と略直交して上記前面壁から剛
壁まで上記共鳴器型吸音装置の厚み方向全域に渡って延
びる仕切りを設けることにより上記共鳴器型吸音装置を
複数の吸音ユニットに分割し、各吸音ユニットに対応さ
せて上記前面壁の入口を設けるとともに、上記前面壁ま
たは剛壁の少なくとも一方を各吸音ユニット毎に分割さ
れた分割体として構成し、前面壁または剛壁の各分割体
を互いに独立に移動可能としたものであるから、例え
ば、吸音周波数が位置的に変化するような場合でも、各
吸音ユニット毎の共鳴空間の容積を独立に変化させ、各
吸音ユニット毎の共鳴周波数を当該位置での吸音周波数
と一致させることにより、位置的に変化する吸音周波数
に対応した適応吸音処理が可能となる。According to a second aspect of the present invention, in the resonator type sound absorbing device, the front wall and the rigid wall extend from the front wall to the hard wall substantially in the thickness direction of the resonator type sound absorbing device. By providing a partition, the resonator-type sound absorbing device is divided into a plurality of sound absorbing units, an entrance of the front wall is provided corresponding to each sound absorbing unit, and at least one of the front wall or the rigid wall is provided for each sound absorbing unit. Since each divided body of the front wall or the rigid wall is configured to be movable independently of each other, for example, even when the sound absorbing frequency changes in position, each sound absorbing unit is formed. By changing the volume of each resonance space independently and matching the resonance frequency of each sound absorption unit with the sound absorption frequency at the position, adaptive sound absorption corresponding to the sound absorption frequency that changes positionally Management is possible.
【００５０】請求項３の共鳴器型吸音装置は、請求項２
の構成において、音源からの音の周波数である吸音周波
数を検出する検出器を各吸音ユニット毎に設け、検出さ
れた吸音周波数に基づいて各吸音ユニット毎に共鳴周波
数が吸音周波数と一致するように上記前面壁または剛壁
の分割体を移動させる制御手段を設けたものであるか
ら、上記検出器で検出された吸音周波数に基づいて、各
吸音ユニットの共鳴周波数を当該位置での吸音ユニット
と一致させる制御を自律的に行うことができる。According to a third aspect of the present invention, there is provided a resonator type sound absorbing device.
In the configuration of the above, a detector for detecting the sound absorption frequency that is the frequency of the sound from the sound source is provided for each sound absorption unit, so that the resonance frequency of each sound absorption unit matches the sound absorption frequency based on the detected sound absorption frequency. Since the control means for moving the front wall or the rigid wall divided body is provided, the resonance frequency of each sound absorbing unit matches the sound absorbing unit at the position based on the sound absorbing frequency detected by the detector. Control can be performed autonomously.
【００５１】請求項４の共鳴器型吸音装置は、前面壁を
含む壁体で囲まれた空間を共鳴空間とするとともに、上
記前面壁に上記共鳴空間を外部と連通する入口を設け、
且つ上記壁体内に上記前面壁と略平行な隔壁を設けて上
記共鳴空間を複数に分割し、この隔壁に両側の空間を連
通する連通口を設ける一方、この連通口を開閉する開閉
手段を設けたものであり、上記連通口を開いた場合は上
記隔壁の両側の空間が共鳴空間となり、上記開閉手段に
よって連通口を閉じた場合は隔壁を境界として上記前面
壁側の空間のみが実質的な共鳴空間となるから、上記連
通口を開閉して実質的な共鳴空間の容積を変化させるこ
とにより、共鳴器型吸音装置の共鳴周波数を変化させる
ことができるので、例えば、吸音周波数が時々刻々変化
するような場合でも、それに対応した適応吸音処理が可
能となる。According to a fourth aspect of the present invention, a space surrounded by a wall including a front wall is used as a resonance space, and an entrance is provided in the front wall to communicate the resonance space with the outside.
The resonance space is divided into a plurality of parts by providing a partition wall substantially parallel to the front wall in the wall body, and a communication port for communicating the spaces on both sides is provided on the partition wall, and an opening / closing means for opening and closing the communication port is provided. When the communication port is opened, the space on both sides of the partition wall becomes a resonance space, and when the communication port is closed by the opening / closing means, only the space on the front wall side with the partition wall as a boundary is substantial. Since it becomes a resonance space, the resonance frequency of the resonator type sound absorbing device can be changed by opening and closing the communication port to change the volume of the substantial resonance space, for example, the sound absorbing frequency changes every moment. Even in such a case, adaptive sound absorption processing corresponding to this is possible.
【００５２】請求項５の共鳴器型吸音装置は、請求項４
の構成において、上記壁体内に上記前面壁及び隔壁と略
直交して上記吸音ユニットの厚み方向全域に渡って延び
る仕切りを設けて上記共鳴器型吸音装置を複数の吸音ユ
ニットに分割し、各吸音ユニットに対応させて上記前面
壁の入口、上記隔壁の連通口及び該連通口を開閉する上
記開閉手段を設けたものであるから、例えば、吸音周波
数が位置的に変化するような場合であっても、各吸音ユ
ニット毎に上記開閉手段で連通口を個別に開閉すること
により、各吸音ユニットの共鳴周波数を個別に制御し
て、音源の周囲の各位置毎で最適の吸音処理を実現する
ことが可能となる。According to a fifth aspect of the present invention, there is provided a resonator type sound absorbing device.
In the above structure, a partition is provided in the wall body, which extends substantially perpendicularly to the front wall and the partition wall over the entire area in the thickness direction of the sound absorbing unit, and the resonator type sound absorbing device is divided into a plurality of sound absorbing units. Since the entrance of the front wall, the communication port of the partition and the opening / closing means for opening / closing the communication port are provided in correspondence with the unit, for example, in a case where the sound absorption frequency changes in position. Also, by individually opening and closing the communication port by the opening / closing means for each sound absorbing unit, individually controlling the resonance frequency of each sound absorbing unit and realizing an optimum sound absorbing process at each position around the sound source. Becomes possible.
【００５３】請求項６の共鳴器型吸音装置は、請求項５
の構成において、音源からの音の周波数である吸音周波
数を検出する検出器を各吸音ユニット毎に設け、検出さ
れた吸音周波数に基づいて各吸音ユニット毎に共鳴周波
数が吸音周波数と一致するように上記開閉手段を開閉さ
せる制御手段を設けたものであるから、上記検出器で検
出された吸音周波数に基づいて、各吸音ユニットの共鳴
周波数を当該位置での吸音ユニットと一致させる制御を
自律的に行うことができる。According to a sixth aspect of the present invention, there is provided a resonator type sound absorbing apparatus.
In the configuration of the above, a detector for detecting the sound absorption frequency that is the frequency of the sound from the sound source is provided for each sound absorption unit, so that the resonance frequency of each sound absorption unit matches the sound absorption frequency based on the detected sound absorption frequency. Since the control means for opening and closing the opening / closing means is provided, based on the sound absorbing frequency detected by the detector, the control for matching the resonance frequency of each sound absorbing unit with the sound absorbing unit at the position is performed autonomously. It can be carried out.
【００５４】請求項７の共鳴器型吸音装置は、請求項１
乃至６のいずれかの構成において、上記共鳴器型吸音装
置は音源の一部または全部を被覆するケース部材に取り
付けるか、またはケース部材の一部として構成したもの
であるから、音源自体に共鳴器型吸音装置を設けること
ができ、吸音処理のために余分のスペースを必要としな
い利点がある。According to the seventh aspect of the present invention, there is provided a resonator type sound absorbing device.
In any one of the constitutions from 1 to 6, the resonator type sound absorbing device is attached to a case member covering a part or the whole of the sound source, or is configured as a part of the case member. There is an advantage that a mold type sound absorbing device can be provided, and no extra space is required for sound absorbing processing.
【図１】一般的なヘルムホルツ共鳴器を示す模式図FIG. 1 is a schematic diagram showing a general Helmholtz resonator
【図２】本発明の第１の実施の形態に係る共鳴器型吸音
装置の概略縦断面図。FIG. 2 is a schematic longitudinal sectional view of the resonator type sound absorbing device according to the first embodiment of the present invention.
【図３】第１の実施の形態に係る共鳴器型吸音装置の概
略正面図。FIG. 3 is a schematic front view of the resonator-type sound absorbing device according to the first embodiment.
【図４】第１の実施の形態の共鳴器型吸音装置を含む実
験装置を示す概略縦断面図。FIG. 4 is a schematic longitudinal sectional view showing an experimental apparatus including the resonator-type sound absorbing device of the first embodiment.
【図５】上記実験装置を用いて前面壁と剛壁間のギャッ
プを変化させながら吸音周波数と垂直入射吸音率との関
係を求めた結果を示すグラフ。FIG. 5 is a graph showing the result of obtaining the relationship between the sound absorption frequency and the normal incidence sound absorption coefficient while changing the gap between the front wall and the rigid wall using the experimental apparatus.
【図６】本発明の第２の実施の形態に係る共鳴器型吸音
装置を示す概略縦断面図。FIG. 6 is a schematic longitudinal sectional view showing a resonator type sound absorbing device according to a second embodiment of the present invention.
【図７】Ｘ線リソグラフィ法を用いて前面壁に入口を形
成する様子を示す説明図。FIG. 7 is an explanatory view showing a state in which an entrance is formed in a front wall using an X-ray lithography method.
【図８】上記入口を形成する後続の手順を示す説明図。FIG. 8 is an explanatory view showing a subsequent procedure for forming the entrance.
【図９】本発明の第３の実施の形態に係る共鳴器型吸音
装置を示す概略縦断面図。FIG. 9 is a schematic longitudinal sectional view showing a resonator type sound absorbing device according to a third embodiment of the present invention.
【図１０】第３の実施の形態に係る共鳴器型吸音装置に
おける開閉アクチュエータを示す拡大斜視図。FIG. 10 is an enlarged perspective view showing an opening / closing actuator in a resonator type sound absorbing device according to a third embodiment.
【図１１】第３の実施の形態の共鳴器型吸音装置の開閉
アクチュエータを開閉させながら吸音周波数と垂直入射
吸音率との関係を求めた実験結果を示すグラフ。FIG. 11 is a graph showing an experimental result in which a relationship between a sound absorption frequency and a normal incidence sound absorption coefficient is obtained while opening and closing an opening / closing actuator of the resonator type sound absorbing device according to the third embodiment.
【図１２】本発明の第４の実施の形態に係る共鳴器型吸
音装置の概略縦断面図。FIG. 12 is a schematic longitudinal sectional view of a resonator type sound absorbing device according to a fourth embodiment of the present invention.
【図１３】上記各実施の形態の共鳴器型吸音装置の第１
の適用例を示す斜視図。FIG. 13 shows a first example of the resonator type sound absorbing device of each of the above embodiments.
The perspective view showing the example of application of.
【図１４】上記各実施の形態の共鳴器型吸音装置の第２
の適用例を示す斜視図。FIG. 14 shows a second example of the resonator type sound absorbing device of each of the above embodiments.
The perspective view showing the example of application of.
１１、４１ 共鳴器型吸音装置 １１ｂ、４１ａ 吸音ユニット １２、４２ 前面壁 １３、４３ 剛壁 １３ａ 分割体 １４、４４ 連結壁 １５、４５ 壁体 １６、４６ 共鳴空間 １７、５０ 入口 １８ 移動手段 ２８、６０ 制御手段 ４７ 隔壁 ５１ 連通孔 ５２ 開閉アクチュエータ（開閉手段） 11, 41 Resonator type sound absorbing device 11b, 41a Sound absorbing unit 12, 42 Front wall 13, 43 Rigid wall 13a Divided body 14, 44 Connecting wall 15, 45 Wall 16, 46 Resonant space 17, 50 Inlet 18 Moving means 28, Reference Signs List 60 control means 47 partition 51 communication hole 52 opening / closing actuator (opening / closing means)
Claims (7)
てて対向配置された剛壁と、前面壁と剛壁の周縁部同士
を連結する連結壁とからなる壁体で囲まれた空間を共鳴
空間とするとともに、上記前面壁に上記共鳴空間を外部
と連通する入口を設け、且つ上記前面壁または剛壁の少
なくとも一方を上記連結壁との間で気密を保持しながら
相手側に接近または離間する方向へ移動可能としたこと
を特徴とする共鳴器型吸音装置。1. A wall comprising a front wall, a rigid wall opposed to the front wall at a distance from the front wall, and a connecting wall connecting peripheral edges of the front wall and the rigid wall. The front space is provided with an entrance for communicating the resonance space with the outside, and at least one of the front wall and the rigid wall is kept airtight between the front wall and the connecting wall while the other space is provided as a resonance space. A resonator type sound absorbing device characterized by being movable in a direction approaching or moving away from the device.
交して上記前面壁から剛壁まで上記共鳴器型吸音装置の
厚み方向全域に渡って延びる仕切りを設けることにより
上記共鳴器型吸音装置を複数の吸音ユニットに分割し、
各吸音ユニットに対応させて上記前面壁の入口を設ける
とともに、上記前面壁または剛壁の少なくとも一方を各
吸音ユニット毎に分割された分割体として構成し、前面
壁または剛壁の各分割体を互いに独立に移動可能とした
ことを特徴とする請求項１記載の共鳴器型吸音装置。2. The resonator-type sound absorbing device according to claim 1, wherein a partition extending in the thickness direction of the resonator-type sound absorber from the front wall to the rigid wall substantially perpendicular to the front wall and the rigid wall is provided in the wall body. Dividing the sound absorbing device into multiple sound absorbing units,
Along with providing an entrance of the front wall corresponding to each sound absorbing unit, at least one of the front wall or the rigid wall is configured as a divided body divided for each sound absorbing unit, and each divided body of the front wall or the rigid wall is formed. The resonator type sound absorbing device according to claim 1, wherein the sound absorbing device is movable independently of each other.
を検出する検出器を各吸音ユニット毎に設け、検出され
た吸音周波数に基づいて各吸音ユニット毎に共鳴周波数
が吸音周波数と一致するように上記前面壁または剛壁の
分割体を移動させる制御手段を設けたことを特徴とする
請求項２記載の共鳴器型吸音装置。3. A detector for detecting a sound absorption frequency which is a frequency of a sound from a sound source is provided for each sound absorption unit, and a resonance frequency of each sound absorption unit is matched with the sound absorption frequency based on the detected sound absorption frequency. 3. The resonator type sound absorbing device according to claim 2, further comprising control means for moving the front wall or the rigid wall divided body.
空間とするとともに、上記前面壁に上記共鳴空間を外部
と連通する入口を設け、且つ上記壁体内に上記前面壁と
略平行な隔壁を設けて上記共鳴空間を複数に分割し、こ
の隔壁に両側の空間を連通する連通口を設ける一方、こ
の連通口を開閉する開閉手段を設けたことを特徴とする
共鳴器型吸音装置。4. A space surrounded by a wall including a front wall is defined as a resonance space, an entrance is provided in the front wall to communicate the resonance space with the outside, and the wall is substantially parallel to the front wall. A resonant partition which divides the resonance space into a plurality of sections and provides a communication port for communicating the spaces on both sides with the partition, and an opening / closing means for opening and closing the communication port. .
交して上記吸音ユニットの厚み方向全域に渡って延びる
仕切りを設けて上記共鳴器型吸音装置を複数の吸音ユニ
ットに分割し、各吸音ユニットに対応させて上記前面壁
の入口、上記隔壁の連通口及び該連通口を開閉する上記
開閉手段を設けたことを特徴とする請求項４記載の共鳴
器型吸音装置。5. A partition extending in the thickness direction of the sound absorbing unit in a direction substantially perpendicular to the front wall and the partition wall in the wall body to divide the resonator type sound absorbing device into a plurality of sound absorbing units. 5. The resonator type sound absorbing device according to claim 4, further comprising an inlet of said front wall, a communication port of said partition wall, and said opening / closing means for opening and closing said communication port corresponding to said sound absorbing unit.
を検出する検出器を各吸音ユニット毎に設け、検出され
た吸音周波数に基づいて各吸音ユニット毎に共鳴周波数
が吸音周波数と一致するように上記開閉手段を開閉させ
る制御手段を設けたことを特徴とする請求項５記載の共
鳴器型吸音装置。6. A detector for detecting a sound absorption frequency which is a frequency of a sound from a sound source is provided for each sound absorption unit, and a resonance frequency of each sound absorption unit matches the sound absorption frequency based on the detected sound absorption frequency. 6. The resonator type sound absorbing device according to claim 5, further comprising control means for opening and closing said opening and closing means.
は全部を被覆するケース部材に取り付けるか、またはケ
ース部材の一部として構成することを特徴とする請求項
１乃至６のいずれか記載の共鳴器型吸音装置。7. The sound absorber according to claim 1, wherein the sound absorber is mounted on a case member that covers a part or the whole of the sound source, or is configured as a part of the case member. Resonator type sound absorber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26672698A JP3486629B2 (en) | 1998-09-21 | 1998-09-21 | Resonator type sound absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26672698A JP3486629B2 (en) | 1998-09-21 | 1998-09-21 | Resonator type sound absorber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000099034A true JP2000099034A (en) | 2000-04-07 |
| JP3486629B2 JP3486629B2 (en) | 2004-01-13 |
Family
ID=17434840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26672698A Expired - Fee Related JP3486629B2 (en) | 1998-09-21 | 1998-09-21 | Resonator type sound absorber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3486629B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007252938A (en) * | 2007-05-07 | 2007-10-04 | Mitsubishi Electric Corp | Noise reducer |
| US7942234B2 (en) | 2006-08-29 | 2011-05-17 | Nec Display Solutions, Ltd. | Noise suppressor, electronic apparatus, and noise suppression characteristic control method |
| KR101829586B1 (en) * | 2017-06-27 | 2018-02-20 | 정광민 | Apparatus for varying the reverberation time |
| WO2020036027A1 (en) * | 2018-08-17 | 2020-02-20 | 富士フイルム株式会社 | Soundproof structural body and soundproof unit |
| CN111622367A (en) * | 2020-06-11 | 2020-09-04 | 河南理工大学 | Noise reduction device for sound absorption of recording studio |
| CN112567452B (en) * | 2018-08-17 | 2024-08-02 | 富士胶片株式会社 | Sound insulation structure and sound insulation unit |
-
1998
- 1998-09-21 JP JP26672698A patent/JP3486629B2/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7942234B2 (en) | 2006-08-29 | 2011-05-17 | Nec Display Solutions, Ltd. | Noise suppressor, electronic apparatus, and noise suppression characteristic control method |
| US8127886B2 (en) | 2006-08-29 | 2012-03-06 | Nec Display Solutions, Ltd. | Noise suppressor, electronic apparatus, and noise suppression characteristic control method |
| JP2007252938A (en) * | 2007-05-07 | 2007-10-04 | Mitsubishi Electric Corp | Noise reducer |
| KR101829586B1 (en) * | 2017-06-27 | 2018-02-20 | 정광민 | Apparatus for varying the reverberation time |
| WO2020036027A1 (en) * | 2018-08-17 | 2020-02-20 | 富士フイルム株式会社 | Soundproof structural body and soundproof unit |
| CN112567452A (en) * | 2018-08-17 | 2021-03-26 | 富士胶片株式会社 | Sound insulation structure and sound insulation unit |
| JPWO2020036027A1 (en) * | 2018-08-17 | 2021-08-12 | 富士フイルム株式会社 | Soundproof structure and soundproof unit |
| US11756521B2 (en) | 2018-08-17 | 2023-09-12 | Fujifilm Corporation | Soundproof structure and soundproof unit |
| CN112567452B (en) * | 2018-08-17 | 2024-08-02 | 富士胶片株式会社 | Sound insulation structure and sound insulation unit |
| CN111622367A (en) * | 2020-06-11 | 2020-09-04 | 河南理工大学 | Noise reduction device for sound absorption of recording studio |
| CN111622367B (en) * | 2020-06-11 | 2021-09-07 | 河南理工大学 | Noise reduction device for sound absorption of recording studio |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3486629B2 (en) | 2004-01-13 |
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