JP2009198902A - Sound absorbing structure, sound absorbing structure group, acoustic chamber, method of adjusting sound absorbing structure and noise reduction method - Google Patents
Sound absorbing structure, sound absorbing structure group, acoustic chamber, method of adjusting sound absorbing structure and noise reduction method Download PDFInfo
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Abstract
Description
本発明は、音を吸音する技術に関する。 The present invention relates to a technique for absorbing sound.
特許文献１に開示された吸音構造のように、板状（または膜状）の振動体と、この振動体の背後の空気層により音を吸収する吸音構造（以下、板・膜振動型吸音構造という）がある。この板・膜振動型吸音構造においては、振動体の質量成分と、空気層のバネ成分によってバネマス系が形成され、振動体が弾性を有して屈曲振動をする場合には、屈曲振動による屈曲系の性質が加わる。 As in the sound absorbing structure disclosed in Patent Document 1, a sound absorbing structure that absorbs sound by a plate-like (or film-like) vibrating body and an air layer behind the vibrating body (hereinafter referred to as a plate / membrane vibrating type sound absorbing structure) Called). In this plate / membrane vibration type sound-absorbing structure, a spring mass system is formed by the mass component of the vibrating body and the spring component of the air layer. System properties are added.
板・膜振動型吸音構造においては、振動体を密度の大きなものにすると吸音される音の周波数が低くなり、吸音される音を低いものにすることができる。しかしながら、振動体の密度を大きくすると振動体全体では質量が大きくなり、ひいては、吸音構造全体が重くなる。吸音構造全体が重くなると、軽量化が求められる用途については使用することが難しくなり、また、壁面などに配置する場合には、吸音構造を支える構造を吸音構造の重さに耐えうる丈夫な構造に必要があり、簡便に配置することが難しくなる。 In the plate / membrane vibration type sound absorbing structure, if the vibrating body has a high density, the frequency of the sound to be absorbed becomes low, and the sound to be absorbed can be made low. However, when the density of the vibrating body is increased, the mass of the entire vibrating body increases, and as a result, the entire sound absorbing structure increases. When the entire sound absorbing structure becomes heavy, it becomes difficult to use it for applications that require weight reduction, and when it is placed on a wall surface, the structure that supports the sound absorbing structure can withstand the weight of the sound absorbing structure. Therefore, it is difficult to arrange easily.
本発明は、上述した背景の下になされたものであり、振動体や吸音構造全体の質量を大きく変更することなく吸音する音を変更可能とする技術を提供することを目的とする。 The present invention has been made under the above-described background, and an object of the present invention is to provide a technique that can change sound absorption without greatly changing the mass of the vibrating body or the entire sound absorbing structure.
上述した課題を解決するために本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度が、振幅の節または極小となる位置の密度と異なることを特徴とする吸音構造を提供する。
この発明では、前記振動体においては、前記振動体が屈曲振動したときに振幅が極大となる位置を含む所定領域の密度が、前記所定領域以外の部分の密度と異なっていてもよい。
In order to solve the above-described problems, the present invention includes a hollow housing having an opening and a plate-like or membrane-like vibrating body, and the opening is closed by the vibrating body. An air layer is formed between the body and the vibration body, and in the vibration body, the density of at least a part of the region other than the position where the vibration body is bent and vibrated or other than the position where the amplitude is minimized is The sound absorbing structure is characterized in that it has a density different from the density of the nodes or minimum positions.
In the present invention, in the vibrating body, the density of a predetermined region including a position where the amplitude becomes maximum when the vibrating body bends and vibrates may be different from the density of a portion other than the predetermined region.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さが、振幅の節または極小となる位置の厚さと異なることを特徴とする吸音構造を提供する。
この発明では、前記振動体においては、前記振動体が屈曲振動したときに振幅が極大となる位置を含む所定領域の厚さが、前記所定領域外の部分の厚さと異なっていてもよい。
The present invention also includes a hollow housing having an opening and a plate-like or membrane-like vibrating body, the opening being closed by the vibrating body, and the housing and the vibrating body. In the vibrating body, the thickness of at least a part of the region other than the position where the amplitude node or the minimum is obtained when the vibrating body vibrates flexibly is the amplitude node or the minimum. The sound absorbing structure is characterized by being different from the thickness of the position.
In this invention, in the vibrating body, the thickness of the predetermined region including the position where the amplitude becomes maximum when the vibrating body is flexibly vibrated may be different from the thickness of the portion outside the predetermined region.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体と、付加部材とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に前記付加部材を有することを特徴とする吸音構造を提供する。
この発明では、前記振動体においては、前記振動体が屈曲振動したときに振幅が極大となる位置を含む所定領域に付加部材を有していてもよい。
また、この発明においては、前記振動体の前記所定領域の表面に付加部材が固定されていてもよい。
また、この発明においては、前記振動体の前記所定領域の部分に付加部材が混入されていてもよい。
The present invention also includes a hollow casing having an opening, a plate-like or membrane-like vibrating body, and an additional member, and the opening is closed by the vibrating body. An air layer is formed with the vibrating body, and the vibrating body has the additional member in at least a part of a region other than a position where an amplitude node or a local minimum when the vibrating body vibrates. A sound absorbing structure is provided.
In this invention, the vibrating body may have an additional member in a predetermined region including a position where the amplitude becomes maximum when the vibrating body is flexibly vibrated.
Moreover, in this invention, the additional member may be fixed to the surface of the predetermined region of the vibrating body.
Moreover, in this invention, the additional member may be mixed in the part of the said predetermined area | region of the said vibrating body.
また、本発明は、上記付加部材を有する吸音構造を複数組み合わせた吸音構造群であって、組み合わされた複数の吸音構造の各付加部材の質量が各々異なる吸音構造群を提供する。
また、本発明は、上記のいずれか一の吸音構造を複数組み合わせた吸音構造群を提供する。
この本発明においては、組み合わされた複数の吸音構造の各空気層のサイズが各々異なっていてもよい。
また、この本発明においては、組み合わされた複数の吸音構造の各空気層の厚みが各々異なっていてもよい。
また、本発明は、上記のいずれか一の吸音構造または上記のいずれか一の吸音体群を有する音響室を提供する。
The present invention also provides a sound absorbing structure group obtained by combining a plurality of sound absorbing structures having the additional member, wherein the additional members of the plurality of combined sound absorbing structures have different masses.
The present invention also provides a sound absorbing structure group in which any one of the above sound absorbing structures is combined.
In the present invention, the sizes of the air layers of the plurality of combined sound absorbing structures may be different from each other.
Moreover, in this invention, the thickness of each air layer of the some sound absorption structure combined may differ, respectively.
In addition, the present invention provides an acoustic chamber having any one of the above sound absorbing structures or any one of the above sound absorbing bodies.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度が、振幅の節または極小となる位置の密度と異なる吸音構造の調整方法であって、前記振動体において前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度を変更して吸音構造の共振周波数を調整する吸音構造の調整方法を提供する。 The present invention also includes a hollow housing having an opening and a plate-like or membrane-like vibrating body, the opening being closed by the vibrating body, and the housing and the vibrating body. In the vibrating body, the density of at least a part of the region other than the position where the amplitude node or the minimum is obtained when the vibrating body is flexibly vibrated becomes the amplitude node or the minimum. A method for adjusting a sound absorbing structure different from a density of a position, wherein the sound absorbing structure is configured by changing a density of at least a part of a region other than a position where an amplitude node or a minimum is obtained when the vibrating body is flexurally vibrated in the vibrating body. A method for adjusting a sound absorbing structure that adjusts the resonance frequency of the sound absorber is provided.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さが、振幅の節または極小となる位置の厚さと異なる吸音構造の調整方法であって、前記振動体において前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さを変更して吸音構造の共振周波数を調整する吸音構造の調整方法を提供する。 The present invention also includes a hollow housing having an opening and a plate-like or membrane-like vibrating body, the opening being closed by the vibrating body, and the housing and the vibrating body. In the vibrating body, the thickness of at least a part of the region other than the position where the amplitude node or the minimum is obtained when the vibrating body vibrates flexibly is the amplitude node or the minimum. A method of adjusting a sound absorbing structure different from a thickness of a position, wherein a thickness of at least a part of a region other than a position where an amplitude node or a local minimum is obtained when the vibrating body is flexibly vibrated in the vibrating body is changed. A method for adjusting a sound absorbing structure for adjusting a resonance frequency of the sound absorbing structure is provided.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体と、付加部材とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に前記付加部材を有する吸音構造の調整方法であって、前記前記付加部材を変更して吸音構造の共振周波数を調整する吸音構造の調整方法を提供する。 The present invention also includes a hollow casing having an opening, a plate-like or membrane-like vibrating body, and an additional member, and the opening is closed by the vibrating body. An air layer is formed with the vibrating body, and the vibrating body includes the additional member in at least a part of a region other than a position where an amplitude node or a minimum is obtained when the vibrating body vibrates. There is provided a method for adjusting a sound absorbing structure, wherein the additional member is changed to adjust a resonance frequency of the sound absorbing structure.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体が振動して騒音を低減する騒音低減方法であって、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度を、振幅の節または極小となる位置の密度と異ならせることを特徴とする騒音低減方法を提供する。 The present invention also includes a hollow housing having an opening and a plate-like or membrane-like vibrating body, the opening being closed by the vibrating body, and the housing and the vibrating body. An air layer is formed, and the vibration body vibrates to reduce noise, wherein the vibration body has a position where an amplitude node or a minimum is obtained when the vibration body is flexibly vibrated. The noise reduction method is characterized in that the density of at least a part of the region other than the above is made different from the density of the amplitude node or the minimum position.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体が振動して騒音を低減する騒音低減方法であって、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さを、振幅の節または極小となる位置の厚さと異ならせることを特徴とする騒音低減方法を提供する。 The present invention also includes a hollow housing having an opening and a plate-like or membrane-like vibrating body, the opening being closed by the vibrating body, and the housing and the vibrating body. An air layer is formed, and the vibration body vibrates to reduce noise, wherein the vibration body has a position where an amplitude node or a minimum is obtained when the vibration body is flexibly vibrated. The noise reduction method is characterized in that the thickness of at least a part of the region other than the above is made different from the thickness of the amplitude node or the minimum position.
また、本発明は、中空で開口部を備えた筐体と、板状または膜状の振動体と、付加部材とを有し、前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、前記振動体が振動して騒音を低減する騒音低減方法であって、前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に前記付加部材を配置することを特徴とする騒音低減方法を提供する。 The present invention also includes a hollow casing having an opening, a plate-like or membrane-like vibrating body, and an additional member, and the opening is closed by the vibrating body. An air layer is formed with the vibration body, and the vibration body vibrates to reduce noise, wherein the vibration body has an amplitude node or vibration when the vibration body is flexibly vibrated. A noise reduction method is provided, wherein the additional member is arranged in at least a part of a region other than the position where the position is minimized.
本発明によれば、振動体や吸音構造全体の質量を大きく変更することなく吸音する音を変更可能となる。 According to the present invention, it is possible to change the sound absorbing sound without greatly changing the mass of the vibrating body or the entire sound absorbing structure.
図１は、本発明の一実施形態に係る吸音構造１の外観図、図２は、吸音構造１の分解斜視図、図３は吸音構造１のＡ−Ａ線断面図である。なお、図面においては、本実施形態の構成を分かりやすく図示するために、吸音構造１の寸法を実際の寸法とは異ならせてある。 FIG. 1 is an external view of a sound absorbing structure 1 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the sound absorbing structure 1, and FIG. 3 is a cross-sectional view taken along line AA of the sound absorbing structure 1. In the drawings, the dimensions of the sound absorbing structure 1 are different from the actual dimensions in order to easily illustrate the configuration of the present embodiment.
図に示したように、吸音構造１は、吸音構造１を構成する部材として筐体１０と振動体２０を有している。合成樹脂で形成されている筐体１０は、正方形の角管の一方の開口部を閉じた形状となっており、筐体１０の底面となる底面部１１と、筐体１０の側壁となる側壁１２を有している。 As shown in the figure, the sound absorbing structure 1 includes a housing 10 and a vibrating body 20 as members constituting the sound absorbing structure 1. The casing 10 formed of a synthetic resin has a shape in which one opening of a square square tube is closed, and includes a bottom surface portion 11 serving as a bottom surface of the casing 10 and a sidewall serving as a sidewall of the casing 10. 12.
振動体２０は、弾性を有する合成樹脂で形成された板状で正方形の第１部材２１と、第２部材２２とで構成されており、力を加えると変形し、弾性により復元力を発生して振動する部材である。第２部材２２は、第１部材２１より面密度が小さく弾性を有する合成樹脂で形成され、中央部分に正方形の孔を有している。本実施形態においては、第１部材２１と第２部材２２の厚さは同じであり、第１部材２１が第２部材２２の孔に固着されて板状の振動体２０が形成されている。
なお、本実施形態においては、振動体２０を構成する部材の素材は合成樹脂としているが、振動体２０を構成する部材の素材は合成樹脂に限定されず、弾性を有し板振動が生じるのであれば紙、金属、繊維板など他の素材であってもよい。
また、本実施形態においては、振動体２０における第１部材２１の領域は、振動体２０が屈曲振動したときに振幅が極大となる位置を含む領域となっている。なお、第１部材２１の領域は、振動体２０が屈曲振動したときに振幅が極大となる位置を含むのであれば、図に示した広さに限定されず任意に変更することができる。
The vibrating body 20 is composed of a plate-like square first member 21 and a second member 22 formed of a synthetic resin having elasticity, and deforms when a force is applied, and generates a restoring force due to elasticity. This is a member that vibrates. The second member 22 is formed of a synthetic resin having a smaller surface density than the first member 21 and having elasticity, and has a square hole in the central portion. In the present embodiment, the first member 21 and the second member 22 have the same thickness, and the first member 21 is fixed to the hole of the second member 22 to form the plate-like vibrating body 20.
In this embodiment, the material of the member constituting the vibrating body 20 is a synthetic resin. However, the material of the member constituting the vibrating body 20 is not limited to the synthetic resin, and has elasticity and plate vibration occurs. Other materials such as paper, metal, and fiberboard may be used.
In the present embodiment, the region of the first member 21 in the vibrating body 20 is a region including a position where the amplitude becomes maximum when the vibrating body 20 undergoes bending vibration. The region of the first member 21 is not limited to the area shown in the drawing and can be arbitrarily changed as long as it includes a position where the amplitude becomes maximum when the vibrating body 20 undergoes bending vibration.
底面部１１を側壁１２に固着して筐体１０を構成し、振動体２０を筐体１０の開口部に接着して固定することにより吸音構造１の内部（振動体２０の背後）に区画された空気層３０が形成され、吸音構造１においては、振動体２０の質量成分と空気層３０のバネ成分によってバネマス系の吸音メカニズムが形成される。また、吸音構造１においては振動体２０が弾性を有して屈曲振動をするため、屈曲振動による屈曲系の吸音メカニズムが加わる。なお、空気層３０は、筐体１０に多少の開口部を設けて密閉されていなくてもよい。
そして、吸音構造１においては、音波が振動体２０に到達すると、音波の音圧と吸音構造１の空気層３０内の圧力との差により振動体２０が振動し、音波のエネルギーは、この振動により消費されて音が吸音される。
ここで、吸音構造１は、バネマス系と屈曲系の両方の吸音メカニズムが形成されているため、吸音される音の周波数と吸音率との関係を見ると、バネマス系の共振周波数における吸音率及び屈曲系の共振周波数における吸音率が高くなる。
The bottom surface portion 11 is fixed to the side wall 12 to form the housing 10, and the vibrating body 20 is bonded and fixed to the opening of the housing 10 to be partitioned inside the sound absorbing structure 1 (behind the vibrating body 20). The air layer 30 is formed, and in the sound absorbing structure 1, a spring mass sound absorbing mechanism is formed by the mass component of the vibrating body 20 and the spring component of the air layer 30. In the sound absorbing structure 1, since the vibrating body 20 has elasticity and bends and vibrates, a bending-type sound absorbing mechanism by bending vibration is added. Note that the air layer 30 may not be sealed by providing some openings in the housing 10.
In the sound absorbing structure 1, when the sound wave reaches the vibrating body 20, the vibrating body 20 vibrates due to the difference between the sound pressure of the sound wave and the pressure in the air layer 30 of the sound absorbing structure 1. The sound is absorbed and consumed.
Here, since the sound absorbing structure 1 has both a spring mass system and a flexural sound absorbing mechanism, the relationship between the sound absorption frequency and the sound absorption coefficient indicates that the sound absorption coefficient at the resonance frequency of the spring mass system and The sound absorption coefficient at the resonance frequency of the bending system is increased.
図４は、空気層３０の縦と横の大きさが１００ｍｍ×１００ｍｍで厚さが１０ｍｍの筐体１０に振動体２０（大きさが１００ｍｍ×１００ｍｍ、厚さ０．８５ｍｍ）を固着し、第１部材２１（大きさ２０ｍｍ×２０ｍｍ、厚さ０．８５ｍｍ）の面密度を変化させた時の吸音構造１の垂直入射吸音率のシミュレート結果を示したグラフである。なおシミュレーション手法は、JIS A 1405-2（音響管による吸音率及びインピーダンスの測定−第２部：伝達関数法）に従って、上記吸音構造を配置した音響管内の音場を有限要素法と境界要素法とを併用して求め、その伝達関数より吸音特性を算出した。
具体的には、図５に示したように、第１部材２１の面密度を、（１）３９９．５［ｇ／ｍ２］、（２）７９９［ｇ／ｍ２］、（３）１１９９［ｇ／ｍ２］、（４）１５９８［ｇ／ｍ２］、（５）２３９７［ｇ／ｍ２］とし、第２部材２２の面密度を７９９［ｇ／ｍ２］として振動体２０の平均面密度を、（１）７８３［ｇ／ｍ２］、（２）７９９［ｇ／ｍ２］、（３）８１５［ｇ／ｍ２］、（４）８３１［ｇ／ｍ２］、（５）８６２．９［ｇ／ｍ２］とした場合のシミュレーション結果である。
なお、（２）の場合は、第１部材２１の面密度と第２部材２２の面密度が同じ、即ち、振動体２０全体が同じ素材で形成されている場合をシミュレートしたものであり、固有振動が１×１のモードに対応する共振周波数として４００Ｈｚにピークが表れている（図５、条件（２）の共振周波数（屈曲系）の欄）。
FIG. 4 shows an example in which a vibrating body 20 (size: 100 mm × 100 mm, thickness: 0.85 mm) is fixed to a casing 10 having a vertical and horizontal size of 100 mm × 100 mm and a thickness of 10 mm. It is the graph which showed the simulation result of the normal incidence sound absorption coefficient of the sound-absorbing structure 1 when changing the surface density of 1 member 21 (size 20mm * 20mm, thickness 0.85mm). The simulation method is finite element method and boundary element method according to JIS A 1405-2 (Measurement of sound absorption coefficient and impedance by sound tube-Part 2: Transfer function method). The sound absorption characteristics were calculated from the transfer function.
Specifically, as shown in FIG. 5, the surface density of the first member 21 is (1) 399.5 [g / m 2 ], (2) 799 [g / m 2 ], (3) 1199. [G / m 2 ], (4) 1598 [g / m 2 ], (5) 2397 [g / m 2 ], and the surface density of the second member 22 is 799 [g / m 2 ]. The average surface density is (1) 783 [g / m 2 ], (2) 799 [g / m 2 ], (3) 815 [g / m 2 ], (4) 831 [g / m 2 ], ( 5) A simulation result in the case of 862.9 [g / m 2 ].
In the case of (2), the surface density of the first member 21 and the surface density of the second member 22 are the same, that is, the case where the entire vibrating body 20 is formed of the same material is simulated. A peak appears at 400 Hz as a resonance frequency corresponding to a mode in which the natural vibration is 1 × 1 (FIG. 5, column of resonance frequency (bending system) in condition (2)).
シミュレート結果を見ると、図４に示したように、３００［Ｈｚ］〜５００［Ｈｚ］の間と、７００［Ｈｚ］付近において吸音率が高くなっている。
７００［Ｈｚ］付近で吸音率が高くなっているのは、振動体２０のマス（mass：質量）と空気層３０のバネ成分によって形成されるバネマス系の共振によるものである。吸音構造１においては上記バネマス系の共振周波数での吸音率をピークとして音が吸音されており、第１部材２１の面密度を大きくしても、振動体２０全体のマスは大きく変わらないので、バネマス系の共振周波数も大きく変わらないことが分かる。
また、３００［Ｈｚ］〜５００［Ｈｚ］の間で吸音率が高くなっているのは、振動体２０の屈曲振動によって形成される屈曲系の共振によるものである。吸音構造１においては屈曲系の共振周波数での吸音率が低音域側のピークとして表れており、第１部材２１の面密度を大きくしていくと屈曲系の共振周波数だけが低くなっていることが分かる。一般に、屈曲系の共振周波数は、振動体の弾性振動を支配する運動方程式で決定され、振動体の密度（面密度）に反比例する。また、前記共振周波数は、固有振動の腹（振幅が極大値となる場所）の密度により大きく影響される。このため、上記シミュレーションでは、１×１の固有モードの腹となる領域を第１部材２１で異なる面密度に形成したので、屈曲系の共振周波数が変化したものである。
Looking at the simulation results, as shown in FIG. 4, the sound absorption coefficient is high between 300 [Hz] and 500 [Hz] and in the vicinity of 700 [Hz].
The reason why the sound absorption coefficient is high in the vicinity of 700 [Hz] is due to resonance of the spring mass system formed by the mass of the vibrating body 20 and the spring component of the air layer 30. In the sound absorbing structure 1, sound is absorbed with the sound absorption coefficient at the resonance frequency of the spring mass system as a peak, and even if the surface density of the first member 21 is increased, the mass of the entire vibrating body 20 does not change greatly. It can be seen that the resonance frequency of the spring mass system does not change greatly.
Moreover, the sound absorption coefficient between 300 [Hz] and 500 [Hz] is high due to the resonance of the bending system formed by the bending vibration of the vibrating body 20. In the sound absorbing structure 1, the sound absorption coefficient at the resonance frequency of the bending system appears as a peak on the low frequency range side, and only the resonance frequency of the bending system decreases as the surface density of the first member 21 increases. I understand. In general, the resonance frequency of the bending system is determined by an equation of motion that governs the elastic vibration of the vibrating body, and is inversely proportional to the density (surface density) of the vibrating body. The resonance frequency is greatly influenced by the density of antinodes (places where the amplitude becomes a maximum value) of the natural vibration. For this reason, in the above simulation, the region that becomes the antinode of the 1 × 1 eigenmode is formed with different areal densities by the first member 21, so that the resonance frequency of the bending system is changed.
このように、シミュレーション結果は、第１部材２１の面密度を第２部材２２の面密度より大きくすると吸音率のピークとなる周波数の内、低音域側の吸音率のピークが更に低音域側へ移動することを表している。従って、第１部材２１の面密度を変更することにより吸音率のピークとなる周波数の一部を更に低音域側または高音域側に移動（シフト）させることができることを表している。
上述した吸音構造１においては、第１部材２１の面密度を変えるだけで吸音される音のピークの周波数を変える（シフトさせる）ことができるため、振動体２０全体を同じ素材で板状に形成し、振動体２０全体の質量を重くして吸音する音を変更する場合と比較して、吸音構造１全体の質量を大きく変えることなく吸音される音を低くできる。
Thus, the simulation result shows that the peak of the sound absorption coefficient on the low frequency side is further lowered to the low frequency side of the frequency at which the sound absorption coefficient peaks when the surface density of the first member 21 is larger than the surface density of the second member 22. It represents moving. Therefore, it is shown that by changing the surface density of the first member 21, a part of the frequency at which the sound absorption coefficient peaks can be moved (shifted) further to the low sound range side or the high sound range side.
In the sound absorbing structure 1 described above, since the frequency of the sound absorption sound can be changed (shifted) simply by changing the surface density of the first member 21, the entire vibrating body 20 is formed into a plate shape with the same material. And compared with the case where the sound which absorbs sound by changing the mass of the whole vibration body 20 is changed, the sound absorbed can be made low, without changing the mass of the whole sound-absorbing structure 1 largely.
［変形例］
以上、本発明の実施形態について説明したが、本発明は上述した実施形態に限定されることなく、他の様々な形態で実施可能である。例えば、上述の実施形態を以下のように変形して本発明を実施してもよい。
[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. For example, the present invention may be implemented by modifying the above-described embodiment as follows.
本発明において振動体２０は、弾性を有する弾性体で形成されているのであれば、板状以外に膜の形状（フィルム状やシート状）であってもよい。なお、板状とは、直方体（立体）に対して相対的に厚さが薄く２次元的な広がりをもつことを意味し、膜状（フィルム状、シート状）とは、板状よりもさらに相対的に厚さが薄く、張力により復元力を発生することを意味する。 In the present invention, as long as the vibrating body 20 is formed of an elastic body having elasticity, the vibrating body 20 may have a film shape (film shape or sheet shape) in addition to the plate shape. The plate shape means that the thickness is relatively thin with respect to a rectangular parallelepiped (solid) and has a two-dimensional extension, and the film shape (film shape, sheet shape) is more than the plate shape. It means that the thickness is relatively thin and a restoring force is generated by tension.
上述した実施形態においては、第１部材２１の形状は正方形となっているが、第１部材２１の形状は、長方形、台形、多角形、円形、楕円形など、他の形状であってもよい。第１部材２１の形状が正方形でなくとも、振動体２０が屈曲振動したときに振幅が極大となる部分の面密度が第２部材２２の面密度より大きければ、振動体２０全体を同じ素材で形成した場合と比較して吸音する音が低くなる。 In the embodiment described above, the shape of the first member 21 is a square, but the shape of the first member 21 may be other shapes such as a rectangle, a trapezoid, a polygon, a circle, and an ellipse. . Even if the shape of the first member 21 is not square, if the surface density of the portion where the amplitude is maximized when the vibrating body 20 is bent and vibrated is larger than the surface density of the second member 22, the entire vibrating body 20 is made of the same material. Compared with the case where it forms, the sound which absorbs sound becomes low.
上述した実施形態においては、振動体２０が屈曲振動したときに振幅が極大となる部分に、第２部材２２より面密度の大きい部材を配置しているが、図６に示した吸音構造１Ａのように、振動体２０全体を同じ素材とし、屈曲振動したときに振幅が極大となる部分（図６では中央部分）を含む第１領域２３の厚さを、周縁部分より厚くするようにしてもよい。
図７は、空気層の縦と横の大きさが１００ｍｍ×１００ｍｍ、厚さ１０ｍｍの筐体１０に面密度８００［ｇ／ｍ２］の振動体２０（大きさ１００ｍｍ×１００ｍｍ）を固着し、第１領域２３の厚さを（１）周縁部分と同じ（厚さ０．８５ｍｍ）、（２）周縁部分の２倍、（３）周縁部分の３倍、（４）周縁部分の４倍、（５）周縁部分の５倍と変えた時の吸音構造１Ａの垂直入射吸音率の測定結果を示したグラフである（測定は、JIS A 1405-2（音響管による吸音率及びインピーダンスの測定−第２部：伝達関数法）による）。
In the above-described embodiment, a member having a surface density larger than that of the second member 22 is disposed in a portion where the amplitude becomes maximum when the vibrating body 20 undergoes bending vibration. However, the sound absorbing structure 1A illustrated in FIG. As described above, the entire vibrating body 20 is made of the same material, and the thickness of the first region 23 including the portion (the central portion in FIG. 6) in which the amplitude becomes maximum when bending vibration is made thicker than the peripheral portion. Good.
FIG. 7 shows a vibrating body 20 (size: 100 mm × 100 mm) having a surface density of 800 [g / m 2 ] fixed to a casing 10 having a vertical and horizontal size of 100 mm × 100 mm and a thickness of 10 mm. The thickness of the first region 23 is (1) the same as the peripheral part (thickness 0.85 mm), (2) twice the peripheral part, (3) three times the peripheral part, (4) four times the peripheral part, (5) It is a graph showing the measurement result of the normal incidence sound absorption coefficient of the sound absorbing structure 1A when changed to 5 times the peripheral part (measurement is JIS A 1405-2 (measurement of sound absorption coefficient and impedance by an acoustic tube) Part 2: Transfer function method)).
図７のグラフに示したように、吸音構造１Ａでは、２００［Ｈｚ］〜５００［Ｈｚ］の間においては、振動体２０の屈曲系の共振周波数での吸音率をピークとして音が吸音されており、第１領域２３の厚さを厚くしていくと屈曲系の共振周波数も低くなっていることが分かる。 As shown in the graph of FIG. 7, in the sound absorbing structure 1 </ b> A, sound is absorbed between 200 [Hz] and 500 [Hz] with the sound absorption coefficient at the resonance frequency of the bending system of the vibrating body 20 as a peak. It can be seen that as the thickness of the first region 23 is increased, the resonance frequency of the bending system is also lowered.
このように、測定結果は、屈曲振動したときに振幅が極大となる部分を含む第１領域２３の厚さを他の部分より厚くすると、吸音される音が低くなることを表しており、また、第１領域２３の厚さを変更することにより、吸音される音を変えることができることを表している。
また、上述した吸音構造１Ａにおいては、第１領域２３の厚さを変えるだけで吸音される音を変えることができるため、振動体２０全体を同じ素材で板状に形成し、振動体２０全体の質量を重くして吸音する音を変更する場合と比較して、吸音構造１Ａ全体の質量を大きく変えることなく、吸音される音を低くできる。なお、第１領域２３の厚さを厚くする場合、周縁部分から滑らかに厚みが厚くなるようにしてもよい。また、第１領域２３の領域は、振動体２０が屈曲振動したときに振幅が極大となる位置を含むのであれば、図に示した広さに限定されず任意に変更することができる。
As described above, the measurement result indicates that the sound absorbed is reduced when the thickness of the first region 23 including the portion where the amplitude becomes maximum when bending vibration is made thicker than the other portions, and This indicates that the sound absorbed can be changed by changing the thickness of the first region 23.
Further, in the sound absorbing structure 1A described above, since the sound to be absorbed can be changed simply by changing the thickness of the first region 23, the entire vibrating body 20 is formed into a plate shape with the same material, and the entire vibrating body 20 is formed. As compared with the case of changing the sound to be absorbed by increasing the mass of the sound, the sound to be absorbed can be lowered without largely changing the mass of the entire sound absorbing structure 1A. Note that when the thickness of the first region 23 is increased, the thickness may be increased smoothly from the peripheral portion. Moreover, the area | region of the 1st area | region 23 will not be limited to the area shown in the figure, but can be arbitrarily changed if the area | region where an amplitude becomes maximum when the vibrating body 20 carries out bending vibration is included.
本発明に係る吸音構造においては、図８に示した吸音構造１Ｂのように振動体２０を板状部材２４と付加部材２５とで構成してもよい。板状部材２４は、弾性を有する素材を板状に形成した正方形の部材であり、付加部材２５は、板状で矩形の部材であり、板状部材２４に固着して一体化される。
振動体２０においては、板状部材２４が屈曲振動したときに振幅が極大となる位置を含む第１領域２３に付加部材２５が貼り付けられている。なお、付加部材２５は振動体２０を筐体１０に取り付けた時に空気層３０に面する側に貼り付けてもよいし、空気層３０に面する側と反対側に貼り付けてもよい。
In the sound absorbing structure according to the present invention, the vibrating body 20 may be composed of the plate-like member 24 and the additional member 25 as in the sound absorbing structure 1B shown in FIG. The plate member 24 is a square member in which a material having elasticity is formed into a plate shape, and the additional member 25 is a plate-like and rectangular member, and is fixed to and integrated with the plate member 24.
In the vibrating body 20, the additional member 25 is attached to the first region 23 including a position where the amplitude becomes maximum when the plate-like member 24 undergoes bending vibration. The additional member 25 may be attached to the side facing the air layer 30 when the vibrating body 20 is attached to the housing 10, or may be attached to the side opposite to the side facing the air layer 30.
この構成においては、上述した実施形態または変形例と同様に、振動体２０の中心領域の質量は、振動体２０全体を同じ素材で板状に形成したときの中心領域の質量より重くなるため、振動体２０全体を同じ素材で板状に形成したときと比較して、屈曲系の共振周波数が低くなり、また、付加部材２５の重さを変更することにより吸音される音を変えることができる。 In this configuration, the mass of the central region of the vibrating body 20 is heavier than the mass of the central region when the entire vibrating body 20 is formed in a plate shape with the same material, as in the above-described embodiment or modification. Compared with the case where the entire vibrating body 20 is formed of the same material in a plate shape, the resonance frequency of the bending system is lowered, and the sound absorbed can be changed by changing the weight of the additional member 25. .
なお、付加部材２５を使用する場合、本発明に係る吸音構造においては、図９に示したように板状部材２４において振動体２０が屈曲振動したときに振幅が極大となる位置を含む領域の内部に付加部材２５を混入して振動体２０を構成してもよい。また、板状部材２４において振動体２０が屈曲振動したときに振幅が極大となる位置を含む領域の内部に部材を混入する場合、混入する部材は板状に限らず、板状部材２４より密度の大きい粒状の部材を複数混入してもよいし、板状部材２４より密度の大きい線状の部材を複数混入してもよい。 When the additional member 25 is used, in the sound absorbing structure according to the present invention, as shown in FIG. 9, in the plate-like member 24, the region including the position where the amplitude becomes maximum when the vibrating body 20 undergoes flexural vibration. The vibrating member 20 may be configured by mixing the additional member 25 therein. In addition, when a member is mixed in a region including a position where the amplitude becomes maximum when the vibrating body 20 undergoes flexural vibration in the plate-shaped member 24, the mixed member is not limited to the plate shape, and the density is higher than that of the plate-shaped member 24. A plurality of granular members may be mixed, or a plurality of linear members having a higher density than the plate-like member 24 may be mixed.
上述した実施形態または変形例に係る吸音構造は、音響特性を制御する各種の音響室に配置することが可能である。ここで各種音響室とは、防音室、ホール、劇場、音響機器のリスニングルーム、会議室等の居室、各種輸送機器の空間、スピーカや楽器などの筐体などである。
なお、上述した実施形態または変形例に係る吸音構造を配置する場合、図１０に示したように大きさの同じ吸音構造を複数組み合わせた吸音体群を配置してもよい。また、図１の吸音構造１を複数組み合わせる場合には、組み合わせる吸音構造毎に第１部材２１の面密度を異ならせ、複数の吸音構造で複数の周波数の音を吸音するようにしてもよい。
また、図６の吸音構造を複数組み合わせる場合には、組み合わせる吸音構造毎に第１領域２３の厚さを異ならせ、複数の吸音構造で複数の周波数の音を吸音するようにしてもよく、また、図８または図９の吸音構造を複数組み合わせる場合には、組み合わせる吸音構造毎に付加部材２５の質量を異ならせ、複数の吸音構造で複数の周波数の音を吸音するようにしてもよい。また、吸音構造を複数組み合わせる場合には、組み合わせる吸音構造毎に空気層３０の縦と横のサイズを一定にして厚さを異ならせてもよく、空気層３０の厚さを一定にして空気層３０の縦と横のサイズを各々異ならせてもよい。また、空気層３０の厚さとサイズの両方を各々異ならせてもよい。
The sound absorbing structure according to the embodiment or the modification described above can be disposed in various acoustic chambers that control acoustic characteristics. Here, the various acoustic rooms include a soundproof room, a hall, a theater, a listening room for audio equipment, a room such as a conference room, a space for various transportation equipment, a housing for speakers, musical instruments, and the like.
In addition, when arrange | positioning the sound-absorbing structure which concerns on embodiment mentioned above or a modification, you may arrange | position the sound-absorbing body group which combined multiple sound-absorbing structures of the same magnitude | size as shown in FIG. Further, when a plurality of sound absorbing structures 1 in FIG. 1 are combined, the surface density of the first member 21 may be varied for each sound absorbing structure to be combined, so that sounds having a plurality of frequencies can be absorbed by the plurality of sound absorbing structures.
In addition, when combining a plurality of sound absorbing structures in FIG. 6, the thickness of the first region 23 may be different for each sound absorbing structure to be combined, and a plurality of sound absorbing structures may absorb sound of a plurality of frequencies. When a plurality of sound absorbing structures shown in FIG. 8 or FIG. 9 are combined, the mass of the additional member 25 may be varied for each sound absorbing structure to be combined, and a plurality of sound absorbing structures may be used to absorb sounds of a plurality of frequencies. In addition, when a plurality of sound absorbing structures are combined, the thickness of the air layer 30 may be different for each sound absorbing structure to be combined with the vertical and horizontal sizes constant, and the thickness of the air layer 30 may be constant. The vertical and horizontal sizes of 30 may be different from each other. Further, both the thickness and the size of the air layer 30 may be different from each other.
また、複数の空気層３０が形成されるように筐体１０の内部を図１１に示したように仕切部材１３で格子状に区切り、振動体２０において各空気層に対向する部分であって振動体２０が屈曲振動したときに振幅が極大となる位置を含む領域に付加部材２５を貼り付けるようにしてもよい。なお、この構成においては、付加部材２５毎に質量を異ならせるようにしてもよい。この構成においても複数の周波数の音を吸音することができる。 Further, as shown in FIG. 11, the inside of the housing 10 is divided into a lattice shape by the partition member 13 so that a plurality of air layers 30 are formed, and the vibration body 20 is a portion facing each air layer and vibrating. You may make it affix the additional member 25 to the area | region including the position where an amplitude becomes maximum when the body 20 carries out bending vibration. In this configuration, the mass of each additional member 25 may be different. Even in this configuration, it is possible to absorb a plurality of frequencies.
本発明においては、振動体２０の振幅が極大となる部分を含むのであれば、振動体２０の中央部分ではなく他の部分に第１部材２１や付加部材２５、第１領域２３の領域などがあってもよい。
また、振動体２０の振幅が極大となる部分を除き、極大となる部分周辺に第１部材２１や付加部材２５があってもよく、振動体２０の振幅が極大となる部分の周辺の厚さが極大となる部分より厚くなっていてもよい。
また、振動体２０の振幅の節または極小となる部分を除いた部分の少なくとも一部に第１部材２１や付加部材２５があってもよく、振動体２０の振幅の節または極小となる部分の周辺の厚さが節又は極小となる部分より厚くなっていてもよい。
In the present invention, the first member 21, the additional member 25, the region of the first region 23, and the like are not in the central portion of the vibrating body 20, as long as it includes a portion where the amplitude of the vibrating body 20 is maximized. There may be.
In addition, the first member 21 and the additional member 25 may be provided around the portion where the amplitude of the vibrating body 20 is maximized, and the thickness around the portion where the amplitude of the vibrating body 20 is maximized. It may be thicker than the portion where becomes maximum.
In addition, the first member 21 and the additional member 25 may be provided in at least a part of a portion excluding the node or the minimum portion of the amplitude of the vibrating body 20. The peripheral thickness may be thicker than a node or a local minimum.
上述した実施形態においては、振動体２０は、筐体１０に接着されて固定支持されており、接着部位においては変位（移動）も回転も拘束されているが、振動体２０は、筐体１０に対して変位が拘束され、回転が許容されている単純支持状態であってもよい。
また、変位が許容されている支持状態や自由支持など他の支持状態であってもよい。
In the above-described embodiment, the vibrating body 20 is fixedly supported by being bonded to the casing 10, and displacement (movement) and rotation are restricted at the bonded portion. A simple support state in which the displacement is restricted and the rotation is allowed may be employed.
Further, other support states such as a support state in which displacement is allowed and a free support may be used.
また、本発明に係る吸音構造においては、上述した実施形態に係る振動体の構成と変形例に係る振動体の構成とを組み合わせて振動体を構成してもよい。 In the sound absorbing structure according to the present invention, the vibrating body may be configured by combining the configuration of the vibrating body according to the above-described embodiment and the configuration of the vibrating body according to the modification.
本発明において、第１部材２１と第２部材２２の密度を異ならせることにより、振動体２０が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度が、振幅の節または極小となる位置の密度と異なる構成にあっては、密度が異なる複数の第１部材２１を準備し、第２部材２２に固着する第１部材２１を交換することにより、吸音構造におけるバネマス系の吸音メカニズムの共振周波数や屈曲系の吸音メカニズムの共振周波数を調整し、吸音構造における吸音率のピークとなる周波数を調整してもよい。
また、振動体２０が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さが、振幅の節または極小となる位置の厚さと異なる構成にあっては、第１領域２３の厚さを削って薄くする、または振動体２０と同じ素材の部材を第１領域２３に付加して厚さを厚くすることにより、吸音構造におけるバネマス系の吸音メカニズムの共振周波数や屈曲系の吸音メカニズムの共振周波数を調整し、吸音構造における吸音率のピークとなる周波数を調整してもよい。
また、振動体２０が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に付加部材２５を有する構成にあっては、密度が異なる複数の付加部材２５を準備し、板状部材２４に固着する付加部材２５を交換することにより、吸音構造におけるバネマス系の吸音メカニズムの共振周波数や屈曲系の吸音メカニズムの共振周波数を調整し、吸音構造における吸音率のピークとなる周波数を調整してもよい。
このような吸音構造の調整方法によれば、バネマス系の吸音メカニズムの共振周波数や屈曲系の吸音メカニズムの共振周波数の調整、吸音構造における吸音率のピークとなる周波数の調整を容易に行うことができる。
In the present invention, by making the density of the first member 21 and the second member 22 different, the density of at least a part of the region other than the position where the vibration body 20 undergoes flexural vibration other than the node or the minimum of the amplitude In the structure different from the density of the position of the node or the local minimum, by preparing a plurality of first members 21 having different densities and replacing the first member 21 fixed to the second member 22, The resonance frequency of the sound absorption mechanism of the spring mass system and the resonance frequency of the sound absorption mechanism of the bending system may be adjusted to adjust the frequency at which the sound absorption coefficient peaks in the sound absorption structure.
If the thickness of at least a part of the region other than the position where the amplitude or node is minimized when the vibrating body 20 undergoes flexural vibration is different from the thickness of the position where the amplitude or node is minimized, The resonance frequency of the sound absorption mechanism of the spring mass system in the sound absorption structure can be reduced by thinning the thickness of the first region 23 or by adding a member made of the same material as the vibrating body 20 to the first region 23 to increase the thickness. The resonance frequency of the sound absorption mechanism of the bending system may be adjusted to adjust the frequency at which the sound absorption coefficient peaks in the sound absorption structure.
In addition, in the configuration having the additional member 25 in at least a part of the region other than the position where the amplitude or node is minimized when the vibrating body 20 undergoes bending vibration, a plurality of additional members 25 having different densities are prepared, By exchanging the additional member 25 fixed to the plate-like member 24, the resonance frequency of the sound absorption mechanism of the spring mass system in the sound absorption structure and the resonance frequency of the sound absorption mechanism of the bending system are adjusted, and the frequency at which the sound absorption coefficient in the sound absorption structure peaks May be adjusted.
According to such a method for adjusting the sound absorbing structure, it is possible to easily adjust the resonance frequency of the sound absorbing mechanism of the spring mass system, the resonant frequency of the sound absorbing mechanism of the bending system, and the frequency at which the sound absorption coefficient in the sound absorbing structure becomes a peak. it can.
上述した吸音構造のうち、振動体２０を第１部材２１と第２部材２２とで構成し、振動体２０が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度が、振幅の節または極小となる位置の密度と異なる吸音構造にあっては、当該吸音構造を、吸音構造の吸音率のピークの周波数の音が騒音として発生している場所に配置して騒音を低減させてもよい。
また、上述した吸音構造のうち、振動体２０の厚さが均一でなく、振動体２０が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さが振幅の節または極小となる位置の厚さと異なる吸音構造についても、当該吸音構造を、吸音構造の吸音率のピークの周波数の音が騒音として発生している場所に配置して騒音を低減させてもよい。
また、上述した吸音構造のうち、振動体２０を板状部材２４と付加部材２５とで構成し、振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に付加部材２５を配置する吸音構造についても、当該吸音構造を、吸音構造の吸音率のピークの周波数の音が騒音として発生している場所に配置して騒音を低減させてもよい。
このように本発明に係る吸音構造を騒音の発生場所に配置して騒音を低減させる騒音低減方法によれば、振動体２０が振動して騒音のエネルギーが消費されて騒音が低減されることとなる。
なお、騒音の発生場所としては、例えば車両や飛行機など各種輸送機器の内部、工場や工事現場などで運転されている各種機械などがある。
Of the above-described sound absorbing structure, the vibrating body 20 is composed of the first member 21 and the second member 22, and at least a part of the region other than the position where the amplitude node or the minimum is obtained when the vibrating body 20 undergoes flexural vibration. If the sound absorption structure has a density different from that of the position where the amplitude is a node or a minimum, the sound absorption structure should be placed in a place where the sound at the peak frequency of the sound absorption coefficient of the sound absorption structure is generated as noise. Noise may be reduced.
Further, in the sound absorbing structure described above, the thickness of the vibrating body 20 is not uniform, and the thickness of at least a part of the region other than the position where the vibration body 20 is bent and vibrated except for the position where the amplitude becomes a node or the minimum is the amplitude. Regarding the sound absorbing structure that is different from the thickness of the node or the position where the position is minimal, the sound absorbing structure may be arranged in a place where the sound having the peak frequency of the sound absorption rate of the sound absorbing structure is generated as noise. .
In addition, in the above-described sound absorbing structure, the vibrating body 20 is configured by the plate-like member 24 and the additional member 25, and at least a part of the region other than the position where the amplitude node or the minimum is obtained when the vibrating body vibrates. As for the sound absorbing structure in which the additional member 25 is disposed, the sound absorbing structure may be disposed in a place where the sound having the peak frequency of the sound absorption rate of the sound absorbing structure is generated as noise.
As described above, according to the noise reduction method for reducing the noise by arranging the sound absorbing structure according to the present invention, the vibration body 20 vibrates and the noise energy is consumed to reduce the noise. Become.
Note that the noise generation location includes, for example, various machines operating in factories, construction sites, etc., inside various transportation equipment such as vehicles and airplanes.
１，１Ａ，１Ｂ・・・吸音構造、１０・・・筐体、１１・・・底面部、１２・・・側壁、１３・・・仕切部材、２０・・・振動体、２１・・・第１部材、２２・・・第２部材、２３・・・第１領域、２４・・・板状部材、２５・・・付加部材、３０・・・空気層 DESCRIPTION OF SYMBOLS 1,1A, 1B ... Sound absorption structure, 10 ... Case, 11 ... Bottom part, 12 ... Side wall, 13 ... Partition member, 20 ... Vibrating body, 21 ... No. 1 member, 22 ... second member, 23 ... first region, 24 ... plate-like member, 25 ... additional member, 30 ... air layer
Claims (19)
板状または膜状の振動体とを有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度が、振幅の節または極小となる位置の密度と異なることを特徴とする吸音構造。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
The vibrator is characterized in that the density of at least a part of the region other than the position where the amplitude node or the local minimum becomes different when the vibration body is flexibly vibrated is different from the density of the amplitude node or the local minimum position. Sound absorbing structure.
板状または膜状の振動体とを有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さが、振幅の節または極小となる位置の厚さと異なることを特徴とする吸音構造。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
In the vibrating body, the thickness of at least a part of a region other than the position where the amplitude node or the local minimum becomes when the vibrating body vibrates is different from the thickness of the position where the amplitude node or the local minimum becomes. Sound absorption structure.
板状または膜状の振動体と、
付加部材と
を有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に前記付加部材を有することを特徴とする吸音構造。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
With additional members,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
The sound absorbing structure according to claim 1, wherein the additional member is provided in at least a part of a region other than a position where an amplitude node or a local minimum is obtained when the vibrating member undergoes bending vibration.
板状または膜状の振動体とを有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度が、振幅の節または極小となる位置の密度と異なる吸音構造の調整方法であって、
前記振動体において前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度を変更して吸音構造の共振周波数を調整する吸音構造の調整方法。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
In the vibrating body, adjustment of the sound absorbing structure in which the density of at least a part of the region other than the position where the amplitude node or the local minimum becomes different when the vibrating body vibrates is different from the density of the amplitude node or the local minimum position. A method,
A method of adjusting a sound absorbing structure, wherein the resonance frequency of the sound absorbing structure is adjusted by changing a density of at least a part of a region other than a position where an amplitude node or a minimum is obtained when the vibrating member is flexibly vibrated.
板状または膜状の振動体とを有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さが、振幅の節または極小となる位置の厚さと異なる吸音構造の調整方法であって、
前記振動体において前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さを変更して吸音構造の共振周波数を調整する吸音構造の調整方法。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
In the vibrating body, the thickness of at least a part of the region other than the position where the amplitude node or the local minimum is obtained when the vibrating body is flexibly vibrated is different from the thickness of the position where the amplitude node or the local minimum is different. An adjustment method,
A method for adjusting a sound absorbing structure, wherein the resonance frequency of the sound absorbing structure is adjusted by changing a thickness of at least a part of a region other than a position where an amplitude node or a minimum is obtained when the vibrating member is flexibly vibrated.
板状または膜状の振動体と、
付加部材と
を有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に前記付加部材を有する吸音構造の調整方法であって、
前記前記付加部材を変更して吸音構造の共振周波数を調整する吸音構造の調整方法。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
With additional members,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
The vibrating body is a method for adjusting a sound absorbing structure having the additional member in at least a part of a region other than a position where an amplitude node or a local minimum when the vibrating body vibrates,
A method for adjusting a sound absorbing structure, wherein the additional member is changed to adjust a resonance frequency of the sound absorbing structure.
板状または膜状の振動体とを有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体が振動して騒音を低減する騒音低減方法であって、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の密度を、振幅の節または極小となる位置の密度と異ならせること
を特徴とする騒音低減方法。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
A noise reduction method in which the vibrator vibrates to reduce noise,
In the vibrating body, the density of at least a part of a region other than a position where the amplitude becomes a node or a minimum when the vibrating body vibrates is different from a density of a position where the amplitude becomes a node or a minimum. Noise reduction method.
板状または膜状の振動体とを有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体が振動して騒音を低減する騒音低減方法であって、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部の厚さを、振幅の節または極小となる位置の厚さと異ならせることを特徴とする騒音低減方法。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
A noise reduction method in which the vibrator vibrates to reduce noise,
In the vibrating body, the thickness of at least a part of the region other than the position where the amplitude node or the local minimum becomes when the vibrating body is flexurally vibrated is different from the thickness of the position where the amplitude node or the local minimum becomes. A characteristic noise reduction method.
板状または膜状の振動体と、
付加部材と
を有し、
前記開口部が前記振動体で塞がれて前記筐体と前記振動体とで空気層が形成されており、
前記振動体が振動して騒音を低減する騒音低減方法であって、
前記振動体においては、前記振動体が屈曲振動したときに振幅の節または極小となる位置以外の領域の少なくとも一部に前記付加部材を配置することを特徴とする騒音低減方法。 A hollow housing with an opening;
A plate-like or membrane-like vibrator,
With additional members,
The opening is closed with the vibrating body, and an air layer is formed between the casing and the vibrating body,
A noise reduction method in which the vibrator vibrates to reduce noise,
In the vibrating body, the noise reduction method is characterized in that the additional member is disposed in at least a part of a region other than a position where an amplitude node or a local minimum becomes when the vibrating body vibrates.
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| JP2008041772A JP2009198902A (en) | 2008-02-22 | 2008-02-22 | Sound absorbing structure, sound absorbing structure group, acoustic chamber, method of adjusting sound absorbing structure and noise reduction method |
| US12/388,282 US20090223738A1 (en) | 2008-02-22 | 2009-02-18 | Sound absorbing structure and vehicle component having sound absorption property |
| CN2009100053807A CN101515453B (en) | 2008-02-22 | 2009-02-20 | Sound absorbing structure and vehicle component having sound absorption property |
| EP09002472A EP2093754A2 (en) | 2008-02-22 | 2009-02-20 | Sound absorbing structure and vehicle component having sound absorption properties |
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|---|---|---|---|
| JP2008041772A Pending JP2009198902A (en) | 2008-02-22 | 2008-02-22 | Sound absorbing structure, sound absorbing structure group, acoustic chamber, method of adjusting sound absorbing structure and noise reduction method |
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| JP (1) | JP2009198902A (en) |
| CN (1) | CN101515453B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2017532478A (en) * | 2014-09-03 | 2017-11-02 | ゼネラル・エレクトリック・カンパニイ | Sound absorption processing assembly for turbine systems |
| KR20190053667A (en) * | 2017-11-10 | 2019-05-20 | 현대자동차주식회사 | Vibration reduction device |
| EP3550557A4 (en) * | 2016-11-29 | 2019-12-18 | Fujifilm Corporation | Soundproof structure |
| CN112259066A (en) * | 2020-10-23 | 2021-01-22 | 西安交通大学 | N-order acoustic metamaterial low-frequency sound insulation structure |
| US11218798B2 (en) | 2019-04-09 | 2022-01-04 | Samsung Electronics Co., Ltd. | Electronic device including a display panel speaker |
| WO2023032618A1 (en) * | 2021-08-30 | 2023-03-09 | 富士フイルム株式会社 | Ventilation path silencer |
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| CN107103898A (en) * | 2011-10-06 | 2017-08-29 | Hrl实验室有限责任公司 | High bandwidth anti-resonance vibration film |
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| CN109859732A (en) * | 2019-03-28 | 2019-06-07 | 苏州拓朴声学科技有限公司 | The standardized sound insulation sound absorption unitary module of one kind and selection method |
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| JP2005134653A (en) * | 2003-10-30 | 2005-05-26 | Kobe Steel Ltd | Sound absorbing structure |
| US7395898B2 (en) * | 2004-03-05 | 2008-07-08 | Rsm Technologies Limited | Sound attenuating structures |
| CN101329865A (en) * | 2007-06-18 | 2008-12-24 | 中国科学院声学研究所 | Resonance sound-absorbing structure for sheet |
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| JPS6165296A (en) * | 1984-09-07 | 1986-04-03 | 日本ゼオン株式会社 | Plaster board excellent in sound insulation |
| JPS6223094A (en) * | 1985-07-23 | 1987-01-31 | 日本ゼオン株式会社 | Sound insulating board material |
| JP2000330571A (en) * | 1999-05-21 | 2000-11-30 | Nok Vibracoustic Kk | Sound absorbing structure |
| JP2006265872A (en) * | 2005-03-22 | 2006-10-05 | Matsushita Electric Works Ltd | Sound absorbing folded-up ceiling unit |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017532478A (en) * | 2014-09-03 | 2017-11-02 | ゼネラル・エレクトリック・カンパニイ | Sound absorption processing assembly for turbine systems |
| EP3550557A4 (en) * | 2016-11-29 | 2019-12-18 | Fujifilm Corporation | Soundproof structure |
| US11049485B2 (en) | 2016-11-29 | 2021-06-29 | Fujifilm Corporation | Soundproof structure |
| KR20190053667A (en) * | 2017-11-10 | 2019-05-20 | 현대자동차주식회사 | Vibration reduction device |
| KR102371259B1 (en) | 2017-11-10 | 2022-03-04 | 현대자동차 주식회사 | Vibration reduction device |
| US11218798B2 (en) | 2019-04-09 | 2022-01-04 | Samsung Electronics Co., Ltd. | Electronic device including a display panel speaker |
| CN112259066A (en) * | 2020-10-23 | 2021-01-22 | 西安交通大学 | N-order acoustic metamaterial low-frequency sound insulation structure |
| WO2023032618A1 (en) * | 2021-08-30 | 2023-03-09 | 富士フイルム株式会社 | Ventilation path silencer |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101515453B (en) | 2012-07-04 |
| CN101515453A (en) | 2009-08-26 |
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