JP2004170665A - Sound absorption and insulation structure - Google Patents

Sound absorption and insulation structure Download PDF

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Publication number
JP2004170665A
JP2004170665A JP2002336160A JP2002336160A JP2004170665A JP 2004170665 A JP2004170665 A JP 2004170665A JP 2002336160 A JP2002336160 A JP 2002336160A JP 2002336160 A JP2002336160 A JP 2002336160A JP 2004170665 A JP2004170665 A JP 2004170665A
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Japan
Prior art keywords
sound absorbing
sound
cell
cells
sound absorption
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JP2002336160A
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Japanese (ja)
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Yasuhiko Nishimura
靖彦 西村
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Toyota Motor Corp
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Toyota Motor Corp
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Priority to JP2002336160A priority Critical patent/JP2004170665A/en
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  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound absorption and insulation structure for realizing not only noise of a specified frequency band, but also efficient absorption to the noise of a wide frequency band. <P>SOLUTION: The sound absorption and insulation structure 10 includes a plurality of sound absorption cells 71 and a substantially sheet-like sound absorption material 60 covering openings of the plurality of the sound absorption cells 71. The plurality of the sound absorption cells 71 are mutually adjacently arranged, have the openings in only one direction (Z direction), and depths H thereof from an opening face to a bottom face are respectively different. <P>COPYRIGHT: (C)2004,JPO

Description

【0001】
【発明の属する技術分野】
本発明は、耳障りな騒音を吸収及び遮断するための吸遮音構造に関する。
【0002】
【従来の技術】
従来の吸音装置として、吸音装置本体内部に箱部を形成し、箱部とエンジンルームとを連通させる連通管を設けた吸音装置が知られている(例えば、特許文献1参照。)。この従来の吸音装置は、共鳴型吸音装置を構成し、エンジンルーム側に箱部の内部空間を連通管を介して開口させることによって、エンジンルーム内の低周波の騒音に対する吸音性能を高めること可能とする。
【0003】
また、その他の従来の吸音装置として、略平らな基板と、当該基板と対向する吸音材とを備え、基板と吸音材との間の空気層を複数の格子状のセルに分割する仕切り板を更に備えた吸音装置が知られている(例えば、特許文献2参照。)。この従来の吸音装置は、吸音材背後の空気層の厚さ(即ち、各セルの深さ)を、吸収すべき音波の波長の1/4倍に設定することにより、音波のエネルギの効率的な減衰を図っている。この従来の吸音装置によれば、特定の周波数成分の吸音率が向上し、吸音性能の向上と共に軽量化が実現される。
【0004】
【特許文献1】
実開平3−64855号
【特許文献2】
特開平11−161282号(第6貢、第16図)
【0005】
【発明が解決しようとする課題】
ところで、車両のエンジンルームや車室内にはエンジンの燃焼音(約1kHz〜3kHz)を主とする広範な周波数域の騒音が存在する。このため、車両のエンジンルーム等においては、ある程度広い周波数域の騒音に対して効果的な吸音がなされる必要がある。しかしながら、上述の従来の吸音装置では、吸音効果が特定の周波数帯域に集中するため、人が感じる官能的な吸音効果を高めることができるものの、ある程度広い周波数域の騒音が存在する空間においては良好な吸音効果が得られないという問題点がある。
【0006】
そこで、本発明は、特定の周波数帯域の騒音のみならず、当該特定の周波数帯域周辺の騒音に対しても効率的な吸音を実現できる、吸遮音構造の提供を目的とする。
【0007】
【課題を解決するための手段】
上記目的は、請求項1に記載する如く、互いに隣接して配設され、一方向のみに開口を有し、開口面から底面までの深さがそれぞれ異なる複数の吸音セルと、
前記複数の吸音セルの開口を覆う吸音材とを含むことを特徴とする、吸遮音構造によって達成される。
【0008】
本発明において、吸遮音構造は、互いに隣接して配設される複数の吸音セルと、吸音材とを含む。複数の吸音セルは、吸音材が設けられる側にのみ開口を有しており、それぞれの開口から異なる距離隔たった位置にそれぞれの底面を有する。この複数の吸音セルに音波が入力されると、各吸音セル内には、入射波と底面で反射した反射波との合成により定在波が形成される。本発明によれば、複数の吸音セルがそれぞれの開口から異なる距離隔たった位置にそれぞれの底面を有するので、開口位置での定在波の位相が各吸音セル相互間で互いに異なる。この結果、吸音セルの開口面内に広がる波面が生まれ、当該開口面内に設けた吸音材による効率的な吸音が実現される。
【0009】
また、本発明によれば、複数の吸音セルがそれぞれの開口から異なる距離隔たった位置にそれぞれの底面を有するので、ある周波数の音波が入力されるとある吸音セル内に吸音材の位置で腹となる定在波が形成され、上記周波数とは異なる周波数の音波が入力されると上記吸音セルとは異なる吸音セル内に吸音材の位置で腹となる定在波が形成されるといったように、幅広い周波数域の音波を効率的に吸収することが可能である。
【0010】
また、本発明による吸遮音構造は、好ましくは、前記吸音セルの底面に立設されたリブを更に含む。これにより、吸音セルの底面の剛性が高まり透過音の低減を図ることができる。
【0011】
また、本発明による吸遮音構造において、前記吸音セルの複数の異なる深さは、好ましくは、吸収すべき周波数帯域の音の波長の1/4倍の値が取りうる範囲内で設定される。これにより、前記所定の周波数帯域の音波は、何れかの吸音セル内において、最も高い粒子速度を持つ位置(即ち、定在波の腹の位置)で吸音材を通過することになるため、幅広い周波数帯域に亘って良好な吸音効果を得ることができる。
【0012】
【発明の実施の形態】
図1は、本発明による吸遮音構造を部分的に示す斜視図であり、図2は、本発明による吸遮音構造の断面図である。本発明による吸遮音構造を備えた吸音装置10は、以下で詳説するように、吸音材60と、セル構造体50とから構成される。
【0013】
セル構造体50は、吸音材60側(図1のZ方向側)に開口を有する複数の吸音セル71を有している。各吸音セル71は、吸音材60側の開口以外は閉塞されており、略同一平面内に開口面を有している。各吸音セル71は、図1及び図2に示すように、隣接する各吸音セル71に対して異なる深さH(図1のZ方向の深さ)を有している。尚、セル構造体50は、アルミニウム板や鋼板等により形成されてもよく、又は、ポリプロピレン系樹脂のような硬質樹脂で一体成形されてもよい。
【0014】
吸音材60は、略平らなシート状であり、セル構造体50吸音セル71の開口面内に設けられ、各吸音セル71の開口を覆っている。尚、吸音材60は、吸音性能を有する材料、例えばグラスウールやロックウール等の無機質繊維、アルミニウム繊維等の金属繊維材料、ポリスチレン系樹脂やポリエチレン系樹脂等のような合成樹脂発泡体、ウレタンやゴム系の軟質な材料、多孔質材料等から形成されてよい。
【0015】
次に、図3を参照して、本発明による吸音装置10の吸音原理について説明する。
【0016】
図3を参照するに、波長λの音波が吸音装置10に入射した場合、上述の吸音セル71内には入射波と反射波との合成により定在波が形成される。この定在波は、波長λの1/4の奇数倍だけ吸音セル71の底面72から離れた位置で腹を有しており、当該腹で音波の粒子速度が最大となる。従って、粒子速度が最大となる位置に吸音材60を設け、最も高い粒子速度を持つ位置で音波を吸音材60に通過させれば、最も効率的に音波を減衰させることができる。
【0017】
この目的のため、本発明による吸音セル71の深さHは、吸収すべき音波の波長λの1/4倍(若しくはその奇数倍)に設定される。また、吸音セル71の開口幅Aは、吸音セル71への音波の効率的な入力を実現するため、吸収すべき周波数帯域の音波の波長λよりも小さく設定される。
【0018】
ところで、本発明による吸音装置10においては、上述の如く、各吸音セル71は、隣接する各吸音セル71に対して異なる深さHを有している。従って、深さHがλ/4に設定された吸音セル71a内に波長λの音波が入射した場合、上述の如く吸音セル71a内には、吸音材60の位置に腹を有する定常波が形成される一方で、吸音セル71aに隣接する深さHの異なる吸音セル71b(本例では深さH>λ/4)内には、吸音材60の位置より下方に腹を有する定常波が形成されることになる。かかる場合、上述した吸音原理を考慮すると、吸音セル71aに入射した音波は効率的に減衰されるのに対して、吸音セル71bに入射した音波は効率的に減衰されないように思われる。
【0019】
しかしながら、本発明による吸音装置10は、上述の如く、各吸音セル71の開口面が略同一平面内に広がっているため、開口面付近で空気粒子の相互作用が引き起こされやすくなり、結果的に音波を効率的に減衰させることができる。より具体的には、上述の如く隣接する吸音セル71a,71bで形成される各定在波の粒子速度が吸音材60の位置で異なるため、吸音材60の位置で圧力バランス(空気の粗密)が崩れ、空気粒子が横方向に押し出されたり、引き戻されたりするような現象が起こる。この結果、吸音材60の内面(吸音セル71の開口面内)の粒子速度の増大が助長され、吸音材60で効果的な吸音を実現することが可能となる。
【0020】
以上の通り、本発明の吸音装置10によれば、略同一平面内に開口面を持つ複数の吸音セル71の深さHを異なる値に設定することによって、吸音材60付近での空気粒子の相互作用を利用した効果的な吸音を実現することが可能となる。
【0021】
更に、本発明による吸音装置10は、上述の如く、異なる深さHの吸音セル71を有している故に、各吸音セル71の協働により広い周波数域の騒音を効果的に吸収することができる。即ち、各吸音セル71の深さHは、所定の周波数域(例えば、1kHz〜3kHz)に亘り効率的な吸音を実現すべく、当該所定の周波数域の音波の1/4波長の値が取りうる範囲(例えば、約28mm〜85mm)内で設定される。従って、本発明の吸音装置10によれば、エンジンの燃焼音(約1kHz〜3kHz)を主とする広範な周波数域の騒音が存在するエンジンルームや車室内においても、良好な吸音効果を得ることが可能である。
【0022】
また、本発明による吸音装置10は、上述の如く、深さHの異なる吸音セル71を有しているので、セル構造体50の底部50bが全体として高い剛性を有することとなり、セル構造体50の底部50bを透過する際に音のエネルギを効果的に損失させることが可能である。従って、本発明による吸音装置10は、セル構造体50が背後(底部50b側)からの音に対して高い遮音性能を併せ持つため、吸音セル71が開口する側の空間の静粛性を一層高めることができる。
【0023】
尚、この遮音性能を更に高めるべく、図4に示すように、セル構造体50の底部50bを構成する個々の吸音セル71の底面72にリブ73を立設することも可能である。即ち、吸音セル71の底面72にリブ73を立設することによって、セル構造体50の底部50bの剛性が更に高くなり、背後からの音に対する吸音装置10の遮音性能を更に高めることができる。
【0024】
次に、本発明による吸音装置10の設置方法と共にそれに関連する遮音性能について図5及び図6を参照して説明する。
【0025】
吸音装置10は、図5に示すように、ボデーパネル(例えば、フロアパネルやルーフパネル等)やエンジンサポートメンバに固定されたブラケット12により所定位置に固定されてよい。この場合、吸音装置10は、セル構造体50の底部50bがボデーパネル等から離間するように、セル構造体50の側部50aでブラケット12により支持される。これにより、セル構造体50の底部50bへのボデーパネル等の振動の直接的な伝達を防止することができる。
【0026】
或いは、吸音装置10は、図6に示すように、最も深さHの大きい吸音セル71の底面72をボデーパネル等にスクリュウ等により締結することや接着剤等により固着することによって、所定位置に設置されてもよい。この場合、セル構造体50の外周を画成する吸音セル71を最も大きい深さHに設定することで、吸音装置10の安定性のある設置状態を実現すると共に、セル構造体50の背後に新たな吸音セル74を画成して当該吸音セル74を利用した吸遮音を実現することも可能である。例えば、図6に示すように、セル構造体50の底部50bとボデーパネルとの間に吸音性のある低ばね材75を介在させることにより、低ばね材75及び吸音材60による吸音装置10の両側(図1のZ方向の両側)での吸音を実現すると共に、セル構造体50の底部50bでの遮音性を高めることも可能である。
【0027】
尚、吸音装置10は、図5に示すように、音源14(例えば、エンジン)からの音波が各吸音セル71の開口に垂直に入射するように、所定位置に設置されてもよい。かかる場合、各吸音セル71に上述の定在波が形成され易くなり、上述した吸音原理により効率的な吸音が実現される。或いは、吸音装置10は、図6に示すように、音源14からの音波が各吸音セル71の開口に斜めに入射するように、所定位置に設置されてもよい。かかる場合、音源14からの音波が各吸音セル71の表面を通過する際に、隣接する吸音セル71への作用が位相差をもって行われるため、吸音材60を通過する粒子速度が増大する。更に各吸音セル71の端76を通過する際に、吸音材60の面内を進行する音波が生まれ、吸音材60で効果的な吸音が実現される。
【0028】
以上、本発明の好ましい実施例について詳説したが、本発明は、上述した実施例に制限されることはなく、本発明の範囲を逸脱することなく、上述した実施例に種々の変形及び置換を加えることができる。
【0029】
例えば、一の吸音セル71は、当該一の吸音セル71に隣接する最大6つの吸音セル71のすべてに対して必ずしも異なる深さを有する必要はなく、隣接する吸音セル71の一部と同一の深さを有してもよい。また、同一の深さを有する同種の吸音セル71の分布は、必ずしも規則的である必要はなく、周辺の音響特性等に応じた不規則性を有してよい。また、吸音セル71の開口幅A(図3参照)は、各吸音セル71で必ずしも同一である必要はなく、上述の如く、吸収すべき音波の波長の相違に応じて異なる値を有してよい。
【0030】
【発明の効果】
本発明は、以上説明したようなものであるから、以下に記載されるような効果を奏する。即ち、本発明によれば、深さの異なる複数の吸音セルを配設することによって、幅広い周波数域の音波を効率的に吸収することができる。また、吸音セルの底面にリブを設けることによって、透過音の低減を図ることもできる。
【図面の簡単な説明】
【図1】本発明による吸遮音構造を部分的に示す斜視図である。
【図2】本発明による吸遮音構造の断面図である。
【図3】本発明による吸遮音構造の吸音原理の説明図である。
【図4】吸音セルの底面に立設したリブを示す斜視図である。
【図5】本発明による吸音装置の設置方法の説明図である。
【図6】本発明による吸音装置の設置方法の説明図である。
【符号の説明】
10 吸音装置10
12 ブラケット
50 セル構造体
50a 側部
50b 底部
60 吸音材
71 吸音セル
72 底面
73 リブ
74 吸音セル
75 低ばね材
A 吸音セルの開口幅
H 吸音セルの深さ
[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sound absorbing and insulating structure for absorbing and blocking harsh noise.
[0002]
[Prior art]
2. Description of the Related Art As a conventional sound absorbing device, there is known a sound absorbing device in which a box portion is formed inside a sound absorbing device main body and a communication pipe for communicating the box portion with an engine room is provided (for example, see Patent Document 1). This conventional sound absorbing device constitutes a resonance type sound absorbing device, and it is possible to enhance the sound absorbing performance against low frequency noise in the engine room by opening the internal space of the box portion on the engine room side through a communication pipe. And
[0003]
Further, as another conventional sound absorbing device, a partition plate that includes a substantially flat substrate and a sound absorbing material facing the substrate, and divides an air layer between the substrate and the sound absorbing material into a plurality of lattice-shaped cells. A sound absorbing device further provided is known (for example, see Patent Document 2). In this conventional sound absorbing device, the thickness of the air layer behind the sound absorbing material (that is, the depth of each cell) is set to 1 / times the wavelength of the sound wave to be absorbed, so that the energy of the sound wave is efficiently reduced. It is aiming for a great attenuation. According to this conventional sound absorbing device, the sound absorbing ratio of a specific frequency component is improved, and the sound absorbing performance is improved and the weight is reduced.
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. 3-64855 [Patent Document 2]
JP-A-11-161282 (6 tribute, FIG. 16)
[0005]
[Problems to be solved by the invention]
By the way, noises in a wide frequency range mainly including engine combustion noise (about 1 kHz to 3 kHz) exist in an engine room or a vehicle interior of a vehicle. For this reason, in a vehicle engine room or the like, it is necessary to effectively absorb noise in a relatively wide frequency range. However, in the above-described conventional sound absorbing device, since the sound absorbing effect is concentrated in a specific frequency band, the sensual sound absorbing effect perceived by a human can be enhanced, but the sound absorbing effect is good in a space where noise in a relatively wide frequency range exists. There is a problem that a great sound absorbing effect cannot be obtained.
[0006]
Therefore, an object of the present invention is to provide a sound absorbing and insulating structure that can realize efficient sound absorption not only for noise in a specific frequency band but also for noise around the specific frequency band.
[0007]
[Means for Solving the Problems]
The above object is, as described in claim 1, a plurality of sound absorbing cells arranged adjacent to each other, having an opening only in one direction, and having different depths from the opening surface to the bottom surface,
A sound absorbing material that covers the openings of the plurality of sound absorbing cells.
[0008]
In the present invention, the sound absorbing and insulating structure includes a plurality of sound absorbing cells arranged adjacent to each other and a sound absorbing material. The plurality of sound absorbing cells have openings only on the side where the sound absorbing material is provided, and have respective bottom surfaces at positions separated by different distances from the respective openings. When a sound wave is input to the plurality of sound absorbing cells, a standing wave is formed in each sound absorbing cell by combining the incident wave and the reflected wave reflected on the bottom surface. According to the present invention, since the plurality of sound absorbing cells have their bottom surfaces at different distances from the respective openings, the phases of the standing waves at the opening positions are different from each other among the sound absorbing cells. As a result, a wavefront spreading in the opening surface of the sound absorbing cell is generated, and efficient sound absorption by the sound absorbing material provided in the opening surface is realized.
[0009]
Further, according to the present invention, since the plurality of sound absorbing cells have respective bottom surfaces at positions different from the respective openings by different distances, when a sound wave of a certain frequency is input, the sound absorbing material is placed in a certain sound absorbing cell at the position of the sound absorbing material. When a sound wave having a frequency different from the above frequency is input, a standing wave that forms an antinode at the position of the sound absorbing material is formed in a sound absorbing cell different from the sound absorbing cell. It is possible to efficiently absorb sound waves in a wide frequency range.
[0010]
In addition, the sound absorbing and insulating structure according to the present invention preferably further includes a rib erected on a bottom surface of the sound absorbing cell. Thus, the rigidity of the bottom surface of the sound absorbing cell is increased, and transmitted sound can be reduced.
[0011]
In the sound absorbing and insulating structure according to the present invention, the plurality of different depths of the sound absorbing cell are preferably set within a range in which a value of 1/4 times the wavelength of sound in a frequency band to be absorbed can be taken. Accordingly, the sound wave in the predetermined frequency band passes through the sound absorbing material at a position having the highest particle velocity (that is, a position of the antinode of the standing wave) in any of the sound absorbing cells. A good sound absorbing effect can be obtained over a frequency band.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a perspective view partially showing a sound absorbing and insulating structure according to the present invention, and FIG. 2 is a sectional view of the sound absorbing and insulating structure according to the present invention. The sound absorbing device 10 having the sound absorbing and insulating structure according to the present invention includes a sound absorbing material 60 and a cell structure 50 as described in detail below.
[0013]
The cell structure 50 has a plurality of sound absorbing cells 71 having openings on the sound absorbing material 60 side (Z direction side in FIG. 1). Each sound absorbing cell 71 is closed except for the opening on the sound absorbing material 60 side, and has an opening surface in substantially the same plane. As shown in FIGS. 1 and 2, each sound absorbing cell 71 has a different depth H (depth in the Z direction in FIG. 1) with respect to each adjacent sound absorbing cell 71. The cell structure 50 may be formed of an aluminum plate, a steel plate, or the like, or may be integrally formed of a hard resin such as a polypropylene resin.
[0014]
The sound absorbing material 60 has a substantially flat sheet shape, is provided in the opening surface of the cell structure 50 sound absorbing cell 71, and covers the opening of each sound absorbing cell 71. The sound absorbing material 60 is made of a material having sound absorbing performance, for example, inorganic fiber such as glass wool or rock wool, metal fiber material such as aluminum fiber, synthetic resin foam such as polystyrene resin or polyethylene resin, urethane or rubber. It may be formed from a system soft material, a porous material, or the like.
[0015]
Next, the sound absorbing principle of the sound absorbing device 10 according to the present invention will be described with reference to FIG.
[0016]
Referring to FIG. 3, when a sound wave having a wavelength λ enters the sound absorbing device 10, a standing wave is formed in the sound absorbing cell 71 by combining the incident wave and the reflected wave. This standing wave has an antinode at a position away from the bottom surface 72 of the sound absorbing cell 71 by an odd multiple of 波長 of the wavelength λ, and the particle velocity of the sound wave becomes maximum at the antinode. Therefore, if the sound absorbing material 60 is provided at the position where the particle velocity is maximum, and the sound wave passes through the sound absorbing material 60 at the position having the highest particle velocity, the sound wave can be attenuated most efficiently.
[0017]
For this purpose, the depth H of the sound absorbing cell 71 according to the present invention is set to 1/4 (or an odd multiple thereof) the wavelength λ of the sound wave to be absorbed. Further, the opening width A of the sound absorbing cell 71 is set smaller than the wavelength λ of the sound wave in the frequency band to be absorbed in order to realize efficient input of the sound wave to the sound absorbing cell 71.
[0018]
By the way, in the sound absorbing device 10 according to the present invention, as described above, each sound absorbing cell 71 has a different depth H with respect to each adjacent sound absorbing cell 71. Therefore, when a sound wave of wavelength λ enters the sound absorbing cell 71a whose depth H is set to λ / 4, a standing wave having an antinode at the position of the sound absorbing material 60 is formed in the sound absorbing cell 71a as described above. On the other hand, a standing wave having an antinode below the position of the sound absorbing material 60 is formed in a sound absorbing cell 71b having a different depth H (in this example, a depth H> λ / 4) adjacent to the sound absorbing cell 71a. Will be. In such a case, considering the above-described sound absorbing principle, it seems that the sound wave incident on the sound absorbing cell 71a is efficiently attenuated, whereas the sound wave incident on the sound absorbing cell 71b is not efficiently attenuated.
[0019]
However, in the sound absorbing device 10 according to the present invention, as described above, since the opening surfaces of the respective sound absorbing cells 71 are spread in substantially the same plane, the interaction of air particles is likely to be caused near the opening surfaces, and as a result, Sound waves can be efficiently attenuated. More specifically, since the particle velocity of each standing wave formed by the adjacent sound absorbing cells 71a and 71b differs at the position of the sound absorbing material 60 as described above, the pressure balance (the density of air) at the position of the sound absorbing material 60. Collapses, causing a phenomenon that air particles are pushed out or pulled back in the lateral direction. As a result, an increase in the particle velocity on the inner surface of the sound absorbing material 60 (in the opening surface of the sound absorbing cell 71) is promoted, and the sound absorbing material 60 can achieve effective sound absorption.
[0020]
As described above, according to the sound absorbing device 10 of the present invention, by setting the depths H of the plurality of sound absorbing cells 71 having the opening surfaces in substantially the same plane to different values, the air particles in the vicinity of the sound absorbing material 60 can be reduced. Effective sound absorption utilizing the interaction can be realized.
[0021]
Further, since the sound absorbing device 10 according to the present invention has the sound absorbing cells 71 having different depths H as described above, it is possible to effectively absorb noise in a wide frequency range by cooperation of the sound absorbing cells 71. it can. That is, the depth H of each sound absorbing cell 71 is a value of 1 / wavelength of the sound wave in the predetermined frequency range in order to realize efficient sound absorption over a predetermined frequency range (for example, 1 kHz to 3 kHz). It is set within the range (for example, about 28 mm to 85 mm). Therefore, according to the sound absorbing device 10 of the present invention, it is possible to obtain a good sound absorbing effect even in an engine room or a vehicle interior where noises in a wide frequency range mainly including engine combustion noise (about 1 kHz to 3 kHz) are present. Is possible.
[0022]
Further, since the sound absorbing device 10 according to the present invention has the sound absorbing cells 71 having different depths H as described above, the bottom 50b of the cell structure 50 has high rigidity as a whole, and the cell structure 50 has a high rigidity. It is possible to effectively lose the energy of sound when transmitting through the bottom 50b. Therefore, in the sound absorbing device 10 according to the present invention, since the cell structure 50 also has high sound insulation performance against sound from behind (the bottom 50b side), the quietness of the space where the sound absorbing cell 71 is opened can be further enhanced. Can be.
[0023]
In order to further enhance the sound insulation performance, as shown in FIG. 4, a rib 73 may be provided upright on the bottom surface 72 of each sound absorbing cell 71 constituting the bottom 50b of the cell structure 50. That is, by providing the rib 73 on the bottom surface 72 of the sound absorbing cell 71, the rigidity of the bottom portion 50b of the cell structure 50 is further increased, and the sound insulating performance of the sound absorbing device 10 against sound from behind can be further improved.
[0024]
Next, the installation method of the sound absorbing device 10 according to the present invention and the related sound insulation performance will be described with reference to FIGS.
[0025]
As shown in FIG. 5, the sound absorbing device 10 may be fixed at a predetermined position by a body panel (for example, a floor panel or a roof panel) or a bracket 12 fixed to an engine support member. In this case, the sound absorbing device 10 is supported by the bracket 12 on the side 50a of the cell structure 50 so that the bottom 50b of the cell structure 50 is separated from the body panel or the like. This can prevent direct transmission of vibration of the body panel or the like to the bottom 50b of the cell structure 50.
[0026]
Alternatively, as shown in FIG. 6, the sound absorbing device 10 can be fixed at a predetermined position by fastening the bottom surface 72 of the sound absorbing cell 71 having the largest depth H to a body panel or the like with a screw or the like, or by fixing with an adhesive or the like. It may be installed. In this case, by setting the sound absorbing cell 71 defining the outer periphery of the cell structure 50 to the largest depth H, a stable installation state of the sound absorbing device 10 is realized, and the sound absorbing device 10 is provided behind the cell structure 50. It is also possible to define a new sound absorbing cell 74 and realize sound absorbing and insulating using the sound absorbing cell 74. For example, as shown in FIG. 6, by interposing a low spring material 75 having a sound absorbing property between the bottom 50b of the cell structure 50 and the body panel, the sound absorbing device 10 using the low spring material 75 and the sound absorbing material 60 is provided. It is possible to realize sound absorption on both sides (both sides in the Z direction in FIG. 1) and to improve the sound insulation at the bottom 50b of the cell structure 50.
[0027]
Note that the sound absorbing device 10 may be installed at a predetermined position such that sound waves from the sound source 14 (for example, an engine) are vertically incident on the openings of the sound absorbing cells 71 as shown in FIG. In this case, the above-described standing wave is easily formed in each sound absorbing cell 71, and efficient sound absorption is realized by the above sound absorbing principle. Alternatively, the sound absorbing device 10 may be installed at a predetermined position such that sound waves from the sound source 14 obliquely enter the openings of the sound absorbing cells 71 as shown in FIG. In such a case, when the sound wave from the sound source 14 passes through the surface of each sound absorbing cell 71, the action on the adjacent sound absorbing cell 71 is performed with a phase difference, so that the velocity of the particles passing through the sound absorbing material 60 increases. Further, when passing through the end 76 of each sound absorbing cell 71, a sound wave traveling in the plane of the sound absorbing material 60 is generated, and the sound absorbing material 60 realizes effective sound absorption.
[0028]
Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and various modifications and substitutions can be made to the above-described embodiment without departing from the scope of the present invention. Can be added.
[0029]
For example, one sound absorbing cell 71 does not necessarily have to have a different depth for all of up to six sound absorbing cells 71 adjacent to the one sound absorbing cell 71, and is the same as a part of the adjacent sound absorbing cell 71. It may have a depth. The distribution of the same type of sound absorbing cells 71 having the same depth does not necessarily have to be regular, and may have irregularities corresponding to the surrounding acoustic characteristics and the like. Also, the opening width A of the sound absorbing cells 71 (see FIG. 3) does not necessarily have to be the same for each sound absorbing cell 71, and has a different value according to the difference in the wavelength of the sound wave to be absorbed as described above. Good.
[0030]
【The invention's effect】
Since the present invention is as described above, the following effects can be obtained. That is, according to the present invention, sound waves in a wide frequency range can be efficiently absorbed by arranging a plurality of sound absorbing cells having different depths. Further, by providing a rib on the bottom surface of the sound absorbing cell, transmitted sound can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view partially showing a sound absorbing and insulating structure according to the present invention.
FIG. 2 is a cross-sectional view of the sound absorbing and insulating structure according to the present invention.
FIG. 3 is an explanatory diagram of a sound absorbing principle of the sound absorbing and insulating structure according to the present invention.
FIG. 4 is a perspective view showing ribs provided on the bottom surface of the sound absorbing cell.
FIG. 5 is an explanatory diagram of a method for installing a sound absorbing device according to the present invention.
FIG. 6 is an explanatory view of a method for installing a sound absorbing device according to the present invention.
[Explanation of symbols]
10 sound absorbing device 10
12 Bracket 50 Cell structure 50a Side 50b Bottom 60 Sound absorbing material 71 Sound absorbing cell 72 Bottom 73 Rib 74 Sound absorbing cell 75 Low spring material A Opening width H of sound absorbing cell H Depth of sound absorbing cell

Claims (3)

互いに隣接して配設され、一方向のみに開口を有し、開口面から底面までの深さがそれぞれ異なる複数の吸音セルと、
前記複数の吸音セルの開口を覆う吸音材とを含むことを特徴とする、吸遮音構造。
A plurality of sound absorbing cells arranged adjacent to each other, having an opening only in one direction, and having different depths from the opening surface to the bottom surface,
A sound absorbing material covering openings of the plurality of sound absorbing cells.
前記吸音セルの底面に立設されたリブを更に含む、請求項1記載の吸遮音構造。The sound absorbing and insulating structure according to claim 1, further comprising a rib provided on a bottom surface of the sound absorbing cell. 前記吸音セルの複数の異なる深さは、吸収すべき周波数帯域の音の波長の1/4倍の値が取りうる範囲内に属する、請求項1又は2記載の吸遮音構造。The sound absorbing and insulating structure according to claim 1, wherein the plurality of different depths of the sound absorbing cell belong to a range in which a value of 倍 times the wavelength of sound in a frequency band to be absorbed can be taken.
JP2002336160A 2002-11-20 2002-11-20 Sound absorption and insulation structure Pending JP2004170665A (en)

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006195257A (en) * 2005-01-14 2006-07-27 Mazda Motor Corp Resonator structure
JP2006195258A (en) * 2005-01-14 2006-07-27 Mazda Motor Corp Resonator structure
JP2007041111A (en) * 2005-08-01 2007-02-15 Railway Technical Res Inst Noise oscillation reducing apparatus and stand-alone type noise oscillation reducing body
JP2008233753A (en) * 2007-03-23 2008-10-02 Shizuoka Prefecture Sound absorbing structure
JP2009080487A (en) * 2008-10-21 2009-04-16 Mitsubishi Heavy Ind Ltd Underwater sound absorbing device
JP2010031582A (en) * 2008-07-30 2010-02-12 Yamaha Corp Sound absorbing structure, sound absorbing structure group, and acoustic room
JP2012166659A (en) * 2011-02-14 2012-09-06 Toyota Motor Corp Vehicle sound absorption structure
WO2024048130A1 (en) * 2022-08-31 2024-03-07 ソニーグループ株式会社 Sound-absorbing device and vehicle

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006195257A (en) * 2005-01-14 2006-07-27 Mazda Motor Corp Resonator structure
JP2006195258A (en) * 2005-01-14 2006-07-27 Mazda Motor Corp Resonator structure
JP2007041111A (en) * 2005-08-01 2007-02-15 Railway Technical Res Inst Noise oscillation reducing apparatus and stand-alone type noise oscillation reducing body
JP2008233753A (en) * 2007-03-23 2008-10-02 Shizuoka Prefecture Sound absorbing structure
JP2010031582A (en) * 2008-07-30 2010-02-12 Yamaha Corp Sound absorbing structure, sound absorbing structure group, and acoustic room
JP2009080487A (en) * 2008-10-21 2009-04-16 Mitsubishi Heavy Ind Ltd Underwater sound absorbing device
JP2012166659A (en) * 2011-02-14 2012-09-06 Toyota Motor Corp Vehicle sound absorption structure
CN103370225A (en) * 2011-02-14 2013-10-23 丰田自动车株式会社 Vehicle sound absorption structure
CN103370225B (en) * 2011-02-14 2015-11-25 丰田自动车株式会社 Vehicle sound absorption structure
WO2024048130A1 (en) * 2022-08-31 2024-03-07 ソニーグループ株式会社 Sound-absorbing device and vehicle

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