JP2000276177A - Sound absorbing material - Google Patents
Sound absorbing materialInfo
- Publication number
- JP2000276177A JP2000276177A JP11076643A JP7664399A JP2000276177A JP 2000276177 A JP2000276177 A JP 2000276177A JP 11076643 A JP11076643 A JP 11076643A JP 7664399 A JP7664399 A JP 7664399A JP 2000276177 A JP2000276177 A JP 2000276177A
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- JP
- Japan
- Prior art keywords
- sound absorbing
- sound
- absorbing material
- density
- sheet
- 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.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、吸音材に係り、特
に低音域のみを吸音できる吸音材に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing material, and more particularly to a sound absorbing material capable of absorbing sound only in a low frequency range.
【０００２】[0002]
【従来の技術】吸音材には、多孔質材料や穴あき板構
造、板状構造、膜状構造などが知られている。グラスウ
ールやロックウールなどの繊維質材や発砲コンクリート
などの多孔質材料を用いる吸音材では、高い周波数は吸
音するが、低い周波数は吸音しようとする周波数の波長
の１／４以上の厚みが必要であり、特に低音域のみを吸
音することは不可能である。2. Description of the Related Art As a sound absorbing material, a porous material, a perforated plate structure, a plate-like structure, a film-like structure and the like are known. In sound absorbing materials using fiber materials such as glass wool and rock wool and porous materials such as foamed concrete, high frequencies absorb sound, but low frequencies require a thickness of 1/4 or more of the wavelength of the frequency to be absorbed. In particular, it is impossible to absorb only the low frequency range.
【０００３】また、穴あき板などに代表されるヘルムホ
ルツレゾネーターは、共鳴・共振現象により吸音するた
め、共鳴する周波数では鋭い吸音ピークを持つという特
徴がある（特開平１−２９８０５２号公報参照）。Further, a Helmholtz resonator represented by a perforated plate or the like absorbs sound by a resonance / resonance phenomenon, and therefore has a feature that it has a sharp sound absorption peak at a resonance frequency (see Japanese Patent Application Laid-Open No. 1-298052).
【０００４】このため、低音域の周波数を幅広く吸音す
るには、数種類の共鳴周波数が異なる共鳴型吸音材を組
み合わせる構造のものが知られている。穴あき板構造な
どの共鳴型吸音材の共鳴周波数ｆｒ（Ｈｚ）は、次の式
に示すように開孔率Ｐ、穴の大きさｄ（ｍ）、板の厚さ
ｔ（ｍ）と背後の空気層の厚さＬ（ｍ）によって定ま
る。共鳴周波数を低くするためには、背後の空気層を厚
くしなければならず、吸音材の体積が大きくなるという
問題点がある。[0004] Therefore, in order to absorb a wide range of frequencies in the low frequency range, there is known a structure in which several types of resonance type sound absorbing materials having different resonance frequencies are combined. The resonance frequency fr (Hz) of the resonance type sound absorbing material such as a perforated plate structure is represented by the following formula, the opening ratio P, the hole size d (m), the plate thickness t (m), and Is determined by the thickness L (m) of the air layer. In order to lower the resonance frequency, it is necessary to increase the thickness of the air layer behind, and there is a problem that the volume of the sound absorbing material increases.
【数１】 (Equation 1)
【０００５】[0005]
【発明が解決しようとする課題】本発明は、このような
問題点を解決するものであり、低周波数域のみの音域を
幅広く吸音できる構造であること、室内に設置するため
に可能な限り薄型であること、定在波が発生しやすいコ
ーナー部などの個所でも吸音特性が変化しない構造であ
ることを主たる目的とする吸音材にある。SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a structure capable of absorbing a wide range of sound only in a low frequency range, and is as thin as possible for indoor installation. And a sound absorbing material whose main purpose is to have a structure in which the sound absorbing characteristics do not change even at corners or the like where standing waves are likely to occur.
【０００６】上記目的とする本発明の吸音材には、次の
ような利用例があり、その一例を説明する。 近時、音響関連のＪＩＳ規格は、国際整合化にとも
なってＩＳＯ規格での測定方法の導入が予定されてい
る。ＩＳＯ規格での音響透過損失測定用の試験室では、
残響室時間を試験室の容積によって調整することが規定
されている。この試験室は、直方体にコンクリートで造
られ、その残響時間は、低い周波数（１００Ｈｚ）では
１０秒、高い周波数（４０００Ｈｚ）では１秒というよ
うに周波数が高くなるに従って残響時間が短くなってい
る。そして、ＩＳＯ規格（ＩＳＯ １４０−１）では、
全周波数域で１〜２（Ｖ／５０）２／３ 秒に調整する
ことを規定している。Ｖは受音室の容積であり、一般的
には５０ｍ３ 程度なので、残響時間は上記の式により
１〜２秒となる。全周波数域で残響時間を１〜２秒に調
整するためには、低音域のみを吸音する吸音材が必要に
なる。このような低周波数域の残響時間調整用に本発明
の吸音材が利用できる。[0006] The sound absorbing material of the present invention aimed at the above purpose has the following usage examples, one example of which will be described. Recently, the measurement method based on the ISO standard is scheduled to be introduced in accordance with the international harmonization of the acoustic JIS standard. In a laboratory for measuring sound transmission loss according to the ISO standard,
It is specified that the reverberation room time is adjusted according to the volume of the test room. This test chamber is made of concrete in a rectangular parallelepiped, and the reverberation time decreases as the frequency increases, such as 10 seconds at a low frequency (100 Hz) and 1 second at a high frequency (4000 Hz). And, in the ISO standard (ISO 140-1),
It regulates to adjust to 1 to 2 (V / 50) 2/3 seconds in the entire frequency range. V is the volume of the sound receiving room, which is generally about 50 m 3 , so that the reverberation time is 1-2 seconds according to the above equation. In order to adjust the reverberation time to 1 to 2 seconds in the entire frequency range, a sound absorbing material that absorbs only the low range is required. The sound absorbing material of the present invention can be used for adjusting the reverberation time in such a low frequency range.
【０００７】 変電設備から発生する低周波音は、基
本周波数５０〜６０Ｈｚの２倍や４倍の周波数の低周波
音が発生する。このような特定の低周波騒音の低減に本
発明の吸音材が利用できる。[0007] The low-frequency sound generated from the substation equipment is a low-frequency sound having a frequency twice or four times the fundamental frequency of 50 to 60 Hz. The sound absorbing material of the present invention can be used to reduce such specific low-frequency noise.
【０００８】 ポンプやコンプレッサなどから発生す
る特定の低周波騒音の低減に本発明の吸音材が利用でき
る。The sound absorbing material of the present invention can be used for reducing specific low-frequency noise generated from a pump, a compressor, and the like.
【０００９】 ホールや会議室などの室内の低周波域
の残響時間の調整が必要な場合に本発明の吸音材が利用
できる。The sound-absorbing material of the present invention can be used when it is necessary to adjust the reverberation time in a low-frequency region in a room such as a hall or a conference room.
【００１０】[0010]
【課題を解決するための手段】上記目的を達成するた
め、本発明に係る第１の発明は、面密度０．８〜５．０
Ｋｇ／ｍ３ の膜状材料からなる吸音シートを長方形の
フレームに張り付けて、前記吸音シートの裏面に密度２
４〜８０Ｋｇ／ｍ３ の繊維質材料をバックアップ材と
して貼り合わせてなることを特徴とするものである。In order to achieve the above object, a first invention according to the present invention provides an areal density of 0.8 to 5.0.
A sound absorbing sheet made of a film material of Kg / m 3 is attached to a rectangular frame, and a density of 2
It is characterized in that a fibrous material of 4 to 80 kg / m 3 is bonded as a backup material.
【００１１】第２の発明は、傾斜状に配した吸音材の裏
面に、頂部側が肉厚となる背後空気層を形成してなるこ
とを特徴とし、第３の発明は、吸音材表面に音響的に透
明な表面材を形成してなることを特徴とするものであ
る。A second aspect of the invention is characterized in that a rear air layer having a thicker top portion is formed on the back surface of the inclined sound absorbing material. It is characterized by forming a transparent material that is transparent.
【００１２】[0012]
【作用】本発明の第１の発明によれば、５００Ｈｚ以下
の低周波数域でのみ吸音する薄型の吸音材となり、ま
た、第２の発明によれば、背後空気層の厚さが変化して
も吸音特性が変化しない吸音材となる。第３の発明によ
れば、吸音材の意匠性を容易に高めることができる。According to the first aspect of the present invention, a thin sound absorbing material which absorbs sound only in a low frequency range of 500 Hz or less is provided. According to the second aspect, the thickness of the back air layer changes. This is also a sound absorbing material whose sound absorbing characteristics do not change. According to the third aspect, the design of the sound absorbing material can be easily improved.
【００１３】[0013]
【発明の実施の形態】本発明の実施形態を図面を参照し
て説明する。図１は、本発明に係る第１実施例の斜視
図、図２は、同第２実施例の斜視図、図３は、同第３実
施例の斜視図である。Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a first embodiment according to the present invention, FIG. 2 is a perspective view of the second embodiment, and FIG. 3 is a perspective view of the third embodiment.
【００１４】本発明の基本形態は、膜状材料からなる吸
音シートの裏面に、繊維質材料からなるバックアップ材
を備えることを特徴としている。この吸音シートとして
面密度０．８〜５．０Ｋｇ／ｍ３ の樹脂シートやゴム
シート、鉄粉などを入れたゴムシートなどを用いた膜状
材料からなる吸音構造のシートを基本としている。The basic aspect of the present invention is characterized in that a backing material made of a fibrous material is provided on the back surface of a sound absorbing sheet made of a film material. As the sound absorbing sheet, a sheet having a sound absorbing structure made of a film material using a resin sheet having a surface density of 0.8 to 5.0 kg / m 3, a rubber sheet, a rubber sheet containing iron powder, or the like is basically used.
【００１５】そして、上記吸音シートには、経年変化で
膜状材料が延びて初期の吸音性能を発揮できないことを
考慮し、膜状材料のヘタリを防止するために、裏面に厚
さ１０〜１００ｍｍ、密度２４〜８０Ｋｇ／ｍ３ の繊
維質材料をバックアップ材として貼り合わせてある。繊
維質材料は、ロックウールやグラスウールなどを使用し
ている。The sound absorbing sheet has a thickness of 10 to 100 mm on the back surface in order to prevent the film material from settling in consideration of the fact that the film material extends over time and cannot exhibit the initial sound absorbing performance. And a fibrous material having a density of 24 to 80 kg / m 3 as a backup material. As the fibrous material, rock wool, glass wool, or the like is used.
【００１６】吸音シートの共鳴周波数ｆｒ（Ｈｚ）は、
次の式に示すように、その面密度ｍ（Ｋｇ／ｍ３ ）と
背後空気層の厚さＬ（ｍ）によって変わるが、本発明の
吸音材では、裏面にバックアップ材が存在するために、
背後空気層の厚さによる影響は殆どないことが特徴であ
り、この特徴は後記するように本願の発明者らが実施し
た測定結果から確認できた。The resonance frequency fr (Hz) of the sound absorbing sheet is
As shown in the following formula, although it depends on the surface density m (Kg / m 3 ) and the thickness L (m) of the air layer behind, in the sound-absorbing material of the present invention, since the backup material exists on the back surface,
The feature is that there is almost no influence by the thickness of the back air layer, and this feature can be confirmed from the measurement results performed by the inventors of the present application as described later.
【数２】 (Equation 2)
【００１７】また、本発明の吸音シートは、上記するよ
うにゴムシートに代表されるように一般的に黒色で意匠
性が低い。このため、吸音シートの表面に音響的に透明
な表面材を配することによって容易に意匠性を高めるこ
とができる。例えば、通気抵抗の低い不織布や網目状の
布、アルミ繊維成形板などが挙げられる。The sound-absorbing sheet of the present invention is generally black and has low designability as represented by a rubber sheet as described above. For this reason, by arranging an acoustically transparent surface material on the surface of the sound absorbing sheet, the design can be easily enhanced. For example, a nonwoven fabric, a mesh-like cloth, and an aluminum fiber molded plate having low airflow resistance can be used.
【００１８】次に、本発明の実施例について説明する。
図１に示す第１実施例の吸音材１は、本発明の基本形態
であり、長方形のフレーム２内に面密度４ｇ／ｃ
ｍ３ 、厚さ５ｍｍの膜状材料からなる吸音構造の吸音
シート３を張り付け、この吸音シート３の裏面に、密度
３２Ｋｇ／ｍ３ 、均一な厚さ５０ｍｍの繊維質材料を
バックアップ材４として配した薄型構成に特徴がある。Next, an embodiment of the present invention will be described.
The sound absorbing material 1 of the first embodiment shown in FIG. 1 is a basic form of the present invention, and has a rectangular frame 2 having an area density of 4 g / c.
A sound absorbing sheet 3 having a sound absorbing structure made of a film material having a thickness of m 3 and a thickness of 5 mm is adhered, and a fibrous material having a density of 32 kg / m 3 and a uniform thickness of 50 mm is disposed on the back surface of the sound absorbing sheet 3 as a backup material 4. It is characterized by its thin configuration.
【００１９】上記フレーム２は、図示の場合、５００×
１０００×５０ｍｍの大きさ寸法に構成してある。ま
た、吸音シート３の表面に通気抵抗の低い上記する表面
材５を付設するとよい。このような構成の吸音材１につ
いて、ＪＩＳ規格で定める残響室法吸音率を測定した結
果は、図４に示すように５００Ｈｚ以下の低周波数域の
みの音域を幅広く吸音できることが確認できた。The above frame 2 has a size of 500 ×
It has a size of 1000 × 50 mm. In addition, it is preferable to attach the above-mentioned surface material 5 having low airflow resistance to the surface of the sound absorbing sheet 3. As a result of measuring the reverberation chamber method sound absorption coefficient defined by the JIS standard for the sound absorbing material 1 having such a configuration, as shown in FIG. 4, it was confirmed that sound can be widely absorbed only in a low frequency range of 500 Hz or less.
【００２０】図２に示す第２実施例の吸音材１ａは、傾
斜状の一端側が厚めのフレーム２ａ内に張り付けた吸音
シート３の裏面に、同様な密度３２Ｋｇ／ｍ３ 、均一
な厚さ５０ｍｍの繊維質材料をバックアップ材４として
裏打ちしてヘタリの防止を施した上、一端側が順次肉厚
になる傾斜状の背後空気層６を形成した構成に特徴があ
り、上記する定在波が生じ易く、共振周波数がずれるコ
ーナー部に適用させるコーナー設置用の吸音材１ａとし
てある。The sound absorbing material 1a of the second embodiment shown in FIG. 2 has a similar density of 32 kg / m 3 and a uniform thickness of 50 mm on the back surface of a sound absorbing sheet 3 attached to a slanted frame 2a having one end side thicker. The backing material 4 is used as a backing material 4 to prevent settling, and the inclined back air layer 6 whose one end side is gradually thicker is formed. This is a sound absorbing material 1a for installing a corner, which is easily applied to a corner portion where the resonance frequency is shifted.
【００２１】これについて、同様に残響室法吸音率を測
定した結果は、図４に示すように５００Ｈｚ以下の低周
波数域のみの音域を幅広く吸音できることが確認でき
た。なお、このフレーム１ａは、１０００×１０００×
２００ｍｍの大きさ寸法に構成してある。As a result, the sound absorption coefficient of the reverberation chamber method was measured in the same manner. As a result, as shown in FIG. 4, it was confirmed that sound can be widely absorbed only in the low frequency range of 500 Hz or less. The frame 1a is 1000 × 1000 ×
It has a size of 200 mm.
【００２２】図３に示す第３実施例の吸音材１ｂは、上
記吸音材１ａを変形させた構成であり、緩く開いた逆Ｖ
字状のフレーム２ｂ内に、互いに頂部に向けて傾斜状に
配した２枚の吸音シート３，３の裏面に、この傾斜に沿
わせて密度３２Ｋｇ／ｍ３、均一な厚さ５０ｍｍの繊維
質材料をバックアップ材４として裏打ちしてヘタリの防
止を施した上、中央部が肉厚な背後空気層６を形成した
構成に特徴がある。The sound absorbing material 1b of the third embodiment shown in FIG. 3 has a configuration in which the above sound absorbing material 1a is deformed,
In the letter-shaped frame 2b, on the back surface of the two sound absorbing sheets 3 and 3 which are inclined toward the top, a fiber material having a density of 32 kg / m 3 and a uniform thickness of 50 mm is formed along this inclination. It is characterized in that the backing material 4 is used as a backing material 4 to prevent settling, and the central portion of the backing air layer 6 is formed thick.
【００２３】この吸音材１ｂは、上記するコーナー部な
ど共振周波数がずれる個所に適用させる背後空気層の厚
さを変えた構成に特徴がある。これについて、同様に残
響室法吸音率を測定した結果は、図４に示すように５０
０Ｈｚ以下の低周波数域のみの音域を幅広く吸音できる
ことが確認できた。なお、このフレーム１ｂは、１００
０×１０００×２００ｍｍの大きさ寸法に構成してあ
る。The sound absorbing material 1b is characterized in that the thickness of the back air layer applied to a place where the resonance frequency is shifted, such as the above-mentioned corner, is changed. For this, similarly, the result of measuring the reverberation chamber method sound absorption coefficient was 50 as shown in FIG.
It was confirmed that sound can be widely absorbed only in the low frequency range of 0 Hz or less. Note that this frame 1b has 100
It has a size of 0 × 1000 × 200 mm.
【００２４】本願の発明者らは、これら吸音材１，１
ａ，１ｂにつき、ＩＳＯ規格に定める条件で音響透過損
失測定を行った。試験室は、コンクリートで容積５０ｍ
３ の直方体に造り、この試験室の壁面に吸音材を設置
しない場合と、壁面に吸音材１を３個、吸音材１ａを２
個、吸音材１ｂを２個それぞれ設置した場合との残響時
間の測定結果を図５に示す。その結果は、図に示される
ように、低周波音が吸音されて低音域の残響時間だけ短
くなり、全周波数域で残響時間が１〜２秒に調整され、
ＩＳＯ規格を満足することができた。The inventors of the present application have proposed that these sound absorbing materials 1, 1
The sound transmission loss was measured for a and 1b under the conditions specified in the ISO standard. The test room is 50m in concrete
3 in which no sound absorbing material is installed on the wall of the test room, and three sound absorbing materials 1 and two sound absorbing materials 1a on the wall.
FIG. 5 shows the measurement results of the reverberation time in the case where two pieces and two pieces of the sound absorbing material 1b were installed. As a result, as shown in the figure, the low-frequency sound is absorbed and shortened by the reverberation time in the low frequency range, and the reverberation time is adjusted to 1-2 seconds in the entire frequency range,
The ISO standard was satisfied.
【００２５】[0025]
【発明の効果】本発明によれば、５００Ｈｚ以下の低音
域のみを吸音できる吸音構造の吸音材であり、また、可
能な限り薄型の構造となり、定在波が発生しやすいコー
ナー部などの個所でも吸音特性が変化しない構造とな
る。According to the present invention, a sound-absorbing material having a sound-absorbing structure capable of absorbing only a low-frequency range of 500 Hz or less, and having a structure as thin as possible, such as a corner portion where a standing wave is easily generated. However, the structure has no change in the sound absorption characteristics.
【００２６】また、本発明によれば、低音域の残響時間
を短くでき、特にＩＳＯ規格に規定されている全周波数
域で１〜２秒に調整できる。Further, according to the present invention, the reverberation time in the low frequency range can be shortened, and in particular, can be adjusted to 1 to 2 seconds in the entire frequency range specified by the ISO standard.
【図１】本発明に係る第１実施例の斜視図。FIG. 1 is a perspective view of a first embodiment according to the present invention.
【図２】同第２実施例の斜視図。FIG. 2 is a perspective view of the second embodiment.
【図３】同第３実施例の斜視図。FIG. 3 is a perspective view of the third embodiment.
【図４】第１〜第３実施例の残響室法吸音率測定結果を
示すグラフ。FIG. 4 is a graph showing the results of measuring the sound absorption coefficient of the reverberation chamber method of the first to third embodiments.
【図５】第１〜第３実施例のＩＳＯ規格の音響透過損失
測定結果を示すグラフ。FIG. 5 is a graph showing the measurement results of sound transmission loss according to the ISO standard of the first to third examples.
１ 吸音材 ２ フレーム ３ 吸音シート ４ バックアップ材 DESCRIPTION OF SYMBOLS 1 Sound absorbing material 2 Frame 3 Sound absorbing sheet 4 Backup material
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4F100 AB10 AC10 AG00 AK01 AN00 AR00A AR00C AS00C AT00C BA02 BA03 BA07 BA10A BA10C BA41A DB17 DD21 DE01B DG11 DG15 GB08 JA13A JA13B JD11C JH00C JH01A YY00A YY00B 5D061 AA04 AA16 AA22 AA29 BB28 BB31 DD02 DD11 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F100 AB10 AC10 AG00 AK01 AN00 AR00A AR00C AS00C AT00C BA02 BA03 BA07 BA10A BA10C BA41A DB17 DD21 DE01B DG11 DG15 GB08 JA13A JA13B JD11C JH00C JH01A YY00A YA02B ADD DD5
Claims (3)
状材料からなる吸音シートを長方形のフレームに張り付
けて、前記吸音シートの裏面に密度２４〜８０Ｋｇ／ｍ
３ の繊維質材料をバックアップ材として貼り合わせて
なることを特徴とする吸音材。1. A sound absorbing sheet made of a film material having an areal density of 0.8 to 5.0 kg / m 3 is attached to a rectangular frame, and a density of 24 to 80 kg / m 3 is provided on the back surface of the sound absorbing sheet.
Sound absorbing material, characterized by comprising bonding a third fibrous material as the backup material.
が肉厚となる背後空気層を形成してなることを特徴とす
る請求項１記載の吸音材。2. The sound-absorbing material according to claim 1, wherein a back air layer having a thicker top portion is formed on the back surface of the sound-absorbing material arranged in an inclined manner.
成してなることを特徴とする請求項１又は２記載の吸音
材。3. The sound absorbing material according to claim 1, wherein an acoustically transparent surface material is formed on the surface of the sound absorbing material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07664399A JP3495942B2 (en) | 1999-03-19 | 1999-03-19 | Sound absorbing material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07664399A JP3495942B2 (en) | 1999-03-19 | 1999-03-19 | Sound absorbing material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000276177A true JP2000276177A (en) | 2000-10-06 |
| JP3495942B2 JP3495942B2 (en) | 2004-02-09 |
Family
ID=13611078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP07664399A Expired - Fee Related JP3495942B2 (en) | 1999-03-19 | 1999-03-19 | Sound absorbing material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3495942B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002193569A (en) * | 2000-12-28 | 2002-07-10 | Toshiba Corp | Elevator car |
-
1999
- 1999-03-19 JP JP07664399A patent/JP3495942B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002193569A (en) * | 2000-12-28 | 2002-07-10 | Toshiba Corp | Elevator car |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3495942B2 (en) | 2004-02-09 |
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