JPH06222778A - Sound absorbing rubber - Google Patents
Sound absorbing rubberInfo
- Publication number
- JPH06222778A JPH06222778A JP5008166A JP816693A JPH06222778A JP H06222778 A JPH06222778 A JP H06222778A JP 5008166 A JP5008166 A JP 5008166A JP 816693 A JP816693 A JP 816693A JP H06222778 A JPH06222778 A JP H06222778A
- Authority
- JP
- Japan
- Prior art keywords
- pores
- rubber
- sound absorbing
- sound
- absorbing rubber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、音波を吸収するゴム
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to rubber that absorbs sound waves.
【０００２】[0002]
【従来の技術】実験水槽の壁面と水面の音波の反射波や
水中の物体からの音波の反射波を少なくする水中用の吸
音材には、ゴム中にアルミや鉛などの金属の粉末を混合
したゴム、木材を楔形に加工した吸音楔、ゴム中に多数
の気孔を封入した吸音ゴムなどが従来用いられている。2. Description of the Related Art A sound absorbing material for underwater that reduces reflected waves of sound waves on the wall and surface of an experimental water tank and reflected waves of underwater objects is mixed with powder of metal such as aluminum or lead in rubber. Conventionally used are rubber, a sound absorbing wedge formed by cutting wood into a wedge shape, and a sound absorbing rubber in which a large number of pores are enclosed in rubber.
【０００３】ゴム中にアルミや鉛などの金属の粉末を封
入したゴムは、ゴム中の金属の粉末の振動が熱に変換さ
れ吸音するもので、数１０ｋＨｚ以上の高周波数で効果
がある。Rubber in which powder of metal such as aluminum or lead is enclosed in rubber absorbs sound by converting vibration of powder of metal in rubber into heat, and is effective at a high frequency of several tens of kHz or more.
【０００４】また、木材の吸音楔は、先端を細くして徐
々に音波を木材中に吸収して吸音するもので、音波の半
波長以上の長さが必要である。そのため１０ｋＨｚ以上
で実用化されているが、低周波にまで効果をもたせるに
は寸法が長くなり、実用的でない。また、木材は腐食す
る欠点もある。Further, the sound absorbing wedge of wood has a thin tip and gradually absorbs sound waves into the wood to absorb sound, and it is necessary that the sound absorbing wedge has a length equal to or longer than a half wavelength of the sound waves. Therefore, it has been put to practical use at 10 kHz or higher, but it is not practical because the dimension becomes long to have an effect even at low frequencies. In addition, wood has the drawback of corroding.
【０００５】さらに、ゴム中に多数の気孔を封入した吸
音ゴムでは、ゴムと気孔の混合体の音響インピーダンス
を気孔の大きさと数とで水の音響インピーダンスに順次
等しくなるようにして、ゴムの材質中で吸音させている
（実吉ほか、超音波技術便覧ｐｐ．４７０〜４７６ 日
刊工業新聞社刊、昭和４１年１０月３１日およびＥ．
Ｇ．Ｒｉｃｈａｒｄｓｏｎ、Ｔｅｃｈｎｉｃａｌ Ａｓ
ｐｅｃｔｓ ｏｆ Ｓｏｕｎｄ ｐｐ．２８１ Ｅｌｓ
ｅｖｉｅｒ Ｐｕｂｌｉｓｈｉｎｇ Ｃｏｍｐａｎｙ
Ａｍｓｔｅｒｄａｍ−Ｎｅｗ Ｙｏｒｋ， １９５
７）。Further, in a sound-absorbing rubber in which a large number of pores are enclosed in rubber, the acoustic impedance of a mixture of rubber and pores is made equal to the acoustic impedance of water sequentially by the size and number of pores, and the material of the rubber is made. (Mikichi et al., Ultrasonic Technology Handbook, pp. 470-476, published by Nikkan Kogyo Shimbun, October 31, 1966, and E.I.
G. Richardson, Technical As
ects of Sound pp. 281 Els
evi Publishing Company
Amsterdam-New York, 195
7).
【０００６】また、ゴム中に微小球の気孔を封入し、微
小球の気孔の振動による吸音をＭｅｙｅｒは報告してい
る。（Ｍｅｙｅｒほか、Ｊ．Ａｃｏｕｓｔ．Ｓｏｃ．Ａ
ｍ．３０．ｐｐ．１１１６−１１２４，１９５８）。Meyer also reported sound absorption due to vibration of the pores of the microspheres by encapsulating the pores of the microspheres in rubber. (Meyer et al., J. Aust. Soc. A.
m. 30. pp. 1116-1124, 1958).
【０００７】さらにまた、微小球の共振周波数は、微小
球の直径に反比例するため従来の吸音ゴムは、例えばゴ
ム板に直径２〜８ｍｍ程度の円柱状の気孔を多数個配列
して設け、その両面にゴム板を張り合わせて、ゴム板中
に多数の気孔を封入した構造もある。この場合の吸音特
性は、ほぼ４〜５ｋＨｚ以上の高周波数で効果がある
が、それ以下の低周波数領域まで吸音特性を広げるに
は、気孔の直径を大きくする必要がある。しかし、従来
の吸音ゴムでは、ゴムの硬度が低いのでゴム板中に外周
寸法が８ｍｍ程度の大きさの気孔の封入が限度であり、
大きな外周寸法の気孔を封入することは困難であった。
従って、４〜５ｋＨｚ以下の低周波数領域での吸音は困
難であった（伊藤 豊ほか：気孔入りゴムの吸音特性
防衛庁技報１８１号 ｐｐ．４９−５５ 堀井 浩ほ
か：吸音楔の水圧特性の改善 海洋音響学会講演論文集
ｐｐ．１−２，１９９１年５月１７日）。Furthermore, since the resonance frequency of the microspheres is inversely proportional to the diameter of the microspheres, the conventional sound absorbing rubber has, for example, a large number of cylindrical pores having a diameter of 2 to 8 mm arranged on a rubber plate. There is also a structure in which a large number of pores are enclosed in the rubber plate by laminating rubber plates on both sides. The sound absorption characteristics in this case are effective at a high frequency of approximately 4 to 5 kHz or higher, but it is necessary to increase the diameter of the pores in order to extend the sound absorption characteristics to a low frequency range lower than that. However, in the conventional sound-absorbing rubber, since the hardness of the rubber is low, it is limited to enclose pores having a peripheral dimension of about 8 mm in the rubber plate.
It has been difficult to enclose pores with large peripheral dimensions.
Therefore, it was difficult to absorb sound in the low frequency region of 4 to 5 kHz or less (Yutaka Ito et al .: Sound absorption characteristics of rubber with pores).
Defense Agency Technical Bulletin 181 pp. 49-55 Hiroi Horii et al .: Improvement of water pressure characteristics of sound absorbing wedge Proceedings of Ocean Acoustics Society pp. 1-2, May 17, 1991).
【０００８】以上のように、これまでは２ｋＨｚ程度の
低周波数から１０ｋＨｚ以上の高周波数までの十分な広
帯域特性を有する吸音ゴムが得られないという問題があ
った。As described above, there has been a problem that a sound absorbing rubber having a sufficient wide band characteristic from a low frequency of about 2 kHz to a high frequency of 10 kHz or more cannot be obtained so far.
【０００９】[0009]
【発明が解決しようとする課題】水中音響機器の使用周
波数は、４〜５ｋＨｚ以下の低周波数領域の場合も多く
あり、従来の吸音ゴムでは十分な効果がなく、実験水槽
では４〜５ｋＨｚ以下での機器の特性に関する測定は困
難であった。また、吸音ゴムの吸音特性を低周波数領域
まで広げるには、気孔の寸法を大きくする必要がある
が、従来の吸音ゴムでは硬度が低いため、気孔の形が変
形してしまい、低周波数領域での吸音が困難であった。The frequency of use of the underwater acoustic equipment is often in the low frequency region of 4 to 5 kHz or less, and the conventional sound absorbing rubber is not sufficiently effective, and in the experimental water tank it is 4 to 5 kHz or less. It was difficult to measure the characteristics of the equipment. Also, in order to expand the sound absorption characteristics of the sound absorbing rubber to the low frequency region, it is necessary to increase the size of the pores, but since the conventional sound absorbing rubber has low hardness, the shape of the pores will be deformed, and in the low frequency region. It was difficult to absorb sound.
【００１０】この発明の目的は、吸音特性が、１０ｋＨ
ｚ以上の高周波領域はもとより、４〜５ｋＨｚ以下の低
周波数領域までの十分な広帯域特性となる吸音ゴムを提
供することにある。An object of the present invention is to have a sound absorption characteristic of 10 kHz.
It is to provide a sound-absorbing rubber having a sufficient wide band characteristic not only in a high frequency region of z or more but also in a low frequency region of 4 to 5 kHz or less.
【００１１】この発明の他の目的は、気孔の外周寸法が
大きくても、気孔が吸音ゴムの吸音特性が十分広帯域特
性を維持できる程度にしか変形しない構造の吸音ゴムを
提供することにある。Another object of the present invention is to provide a sound-absorbing rubber having a structure in which the pores are deformed to such an extent that the sound-absorbing characteristics of the sound-absorbing rubber can sufficiently maintain a wide-band characteristic even when the outer peripheral dimension of the pore is large.
【００１２】[0012]
【課題を解決するための手段】この目的の達成を図るた
め、この発明によれば、ゴム中に多数の気孔を封入した
吸音ゴムにおいて、気孔の内部に気孔壁を支える支柱を
有することを特徴とする。In order to achieve this object, according to the present invention, in a sound absorbing rubber in which a large number of pores are enclosed in a rubber, a column for supporting the pore wall is provided inside the pores. And
【００１３】また、この発明による吸音ゴムによれば、
気孔の外周寸法比が２n （ｎ：整数）又は、ほぼ２n と
なる複数の大きさの異なる気孔を封入して成ることを特
徴とする。According to the sound absorbing rubber of the present invention,
It is characterized in that a plurality of different sized pores having a peripheral dimension ratio of pores of 2 n (n: integer) or approximately 2 n are enclosed.
【００１４】[0014]
【作用】上述したこの発明の構成によれば、気孔に支柱
を設けてあるので、外周寸法の大きな気孔の場合、ゴム
の硬度が小さくてもゴム板の強度を低下することがな
く、従って、気孔が潰れたり、または吸音特性に悪影響
を及ぼすような変形を生じたりすることがない。従っ
て、支柱のある気孔をゴム中に封入した場合は、気孔の
外周寸法を、支柱のない気孔を封入したゴムに比べてゴ
ム板の強度をあまり低下することなく大きくできるの
で、より低周波数での吸音特性が可能となる。According to the above-mentioned structure of the present invention, since the columns are provided with the columns, the strength of the rubber plate does not decrease even if the hardness of the rubber is small in the case of the pores having a large outer peripheral dimension. The pores will not be crushed or deformed to adversely affect the sound absorption characteristics. Therefore, when the pores with columns are enclosed in rubber, the outer diameter of the pores can be increased without significantly lowering the strength of the rubber plate compared to rubber with pores without columns, so at a lower frequency. The sound absorption characteristics of are possible.
【００１５】また、この発明の上述した構成によれば、
外周寸法比が２n （ｎ：整数）または、ほぼ２n となる
複数の異なる寸法の気孔を組み合わせ封入してあるの
で、一番小さい寸法の気孔に対応する共振周波数が一番
高い周波数で、その次に小さい寸法の気孔に対応する共
振周波数がその周波数の半分の周波数、順に、さらに半
分の周波数ごとに共振する吸音特性を有する。一番大き
い寸法の気孔に対応する共振周波数は一番低周波数であ
る。気孔の共振のＱは小さく、気孔の大きさに対応する
吸音特性はなだらかに変化するので、隣り合う寸法の共
振による吸音特性は、スタガーとなるので、気孔の外周
寸法を、倍、倍となる気孔を組み合わせて配列すると、
高周波数から低周波数までの広帯域で吸音特性の良好な
吸音ゴムが実現できる。このとき、外周寸法の大きな気
孔は支柱を有する気孔とする。According to the above-mentioned structure of the present invention,
Since a plurality of differently sized pores having a peripheral dimension ratio of 2 n (n: integer) or approximately 2 n are combined and enclosed, the resonance frequency corresponding to the smallest pore has the highest frequency, The resonance frequency corresponding to the next smaller pore has a sound absorbing characteristic that resonates at a frequency of half the frequency, and in sequence, at each half frequency. The resonance frequency corresponding to the pore with the largest size is the lowest frequency. Since the Q of the resonance of the pores is small and the sound absorption characteristics corresponding to the size of the pores change gently, the sound absorption characteristics due to the resonance of adjacent dimensions become a stagger, so the outer peripheral dimensions of the pores are doubled or doubled. If you combine and arrange the pores,
It is possible to realize a sound absorbing rubber having a wide range of high to low frequencies and good sound absorbing characteristics. At this time, pores having a large outer peripheral dimension are pores having columns.
【００１６】また、同一ゴム板中に上述した支柱を有す
る気孔と支柱を有しない気孔とを混在させてもよく、ま
たそれぞれの気孔の外周寸法比を２n （ｎを固定値）と
して一定値としてもよく、いずれの組み合わせの場合で
も吸音特性を低周波数領域から高周波領域まで、従来よ
りも十分広い領域までに広げることができる。It is also possible to mix the above-mentioned pores having a strut and pores having no strut in the same rubber plate, and the outer peripheral dimension ratio of each pore is set to a constant value of 2 n (n is a fixed value). In any combination, the sound absorption characteristics can be expanded from the low frequency region to the high frequency region, to a region sufficiently wider than the conventional one.
【００１７】[0017]
【実施例】以下、図面を参照しながら、この発明の実施
例について説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１８】なお、図はこの発明が理解できる程度に、
各構成成分の形状、大きさ、および配置関係は概略的に
示してあるにすぎない。また、ここで説明する実施例
は、単なる一例であって、ここに説明される具体的な動
作、順序、および具体的な数値は、これに限定されるも
のではなく、部分的に動作を追加したり、あるいは削除
したり、また別の動作、および数値で置き換えても同様
な効果を達成することができる。It should be noted that the drawings are such that the present invention can be understood.
The shape, size, and positional relationship of each component are only schematically shown. Further, the embodiments described here are merely examples, and the specific operations, sequences, and specific numerical values described herein are not limited thereto, and some operations may be added. The same effect can be achieved by doing or deleting or replacing with another operation and a numerical value.
【００１９】図１、図２は、この発明を説明するための
図で、図１は、図２の吸音ゴム１０のＩ−Ｉ線断面図、
図２は、吸音ゴム１０の部分的平面図である。ゴム板１
１中に、例えば１種類の大きさの気孔１３を所定の間隔
で封入する。気孔としては球形、楕円形、円板形、円筒
形、矩形、半円板形、半円柱形などとする。ここでは製
作の容易な円柱形の気孔の場合について説明する。1 and 2 are views for explaining the present invention. FIG. 1 is a sectional view of the sound absorbing rubber 10 of FIG.
FIG. 2 is a partial plan view of the sound absorbing rubber 10. Rubber plate 1
For example, the pores 13 of one size are enclosed in 1 at predetermined intervals. The pores may be spherical, elliptical, disk-shaped, cylindrical, rectangular, semi-circular, semi-cylindrical, or the like. Here, the case of a cylindrical pore that is easy to manufacture will be described.
【００２０】円柱形の気孔の内部に支柱１５を設け気孔
の形状を円筒状とする。円筒の外周寸法の大きな気孔の
場合でも支柱１５があるため、ゴムの硬度が小さくても
ゴム板の強度を低下することが少ない。ゴム中に封入し
た球形の気孔の壁の外周寸法がゴム中の音波の横波の２
波長に等しい周波数で気孔が共振振動して吸音すること
が報告されている（菊地 年晃：ゴム中の気泡振動と吸
音特性 海洋音響学会誌 １５巻３号、１９８８年７月
ｐｐ．１４８−１５１）、円筒状気孔の場合には、円
筒直径の外周寸法が近似的に球形の外周寸法に相当す
る。外周寸法の大きな気孔の共振周波数は低くなる。従
って、支柱のある気孔をゴム中に封入した場合は、気孔
の外周寸法を支柱のない気孔を封入したゴムに比べて、
ゴム板の強度をあまり低下することなく大きくできるの
で、より低周波数での吸音特性が可能となる。The columns 15 are provided inside the cylindrical pores to make the pores cylindrical. Even in the case of a hole having a large outer peripheral dimension of the cylinder, since the pillars 15 are provided, the strength of the rubber plate is less likely to decrease even if the hardness of the rubber is small. The peripheral dimension of the wall of the spherical pores enclosed in the rubber is the transverse wave of the sound wave in the rubber.
It has been reported that the pores resonate and absorb sound at a frequency equal to the wavelength (Kikuchi Toshiaki: Bubble vibration in rubber and sound absorption characteristics, Journal of the Ocean Acoustic Society, Vol. 15, No. 3, July 1988, pp. 148-151. ), In the case of cylindrical pores, the outer peripheral dimension of the cylinder diameter approximately corresponds to the spherical outer peripheral dimension. The resonance frequency of the pore having a large outer peripheral dimension becomes low. Therefore, when the pores with columns are enclosed in rubber, the outer diameter of the pores is smaller than that of rubber with pores without columns.
Since the strength of the rubber plate can be increased without significantly lowering it, sound absorption characteristics at lower frequencies are possible.
【００２１】支柱１５としては、ゴムと同一の材質でよ
いが、ゴムと特性が近いプラスチックなどの材質を用い
てもよい。The pillar 15 may be made of the same material as rubber, but may be made of a material such as plastic having similar characteristics to rubber.
【００２２】図１、図２では、同一寸法の気孔を規則的
に配列した例を図示したが、気孔の大きさと間隔は、所
定の範囲内であれば任意の大きさと配列でよい。このこ
とは、以下の説明でも同じである。Although FIG. 1 and FIG. 2 show examples in which pores of the same size are regularly arranged, the size and interval of the pores may be any size and arrangement as long as they are within a predetermined range. This also applies to the following description.
【００２３】気孔の外周寸法比が２n （ｎ：整数）とな
る複数の異なる寸法の気孔を組み合わせて封入すれば、
一番小さい寸法の気孔に対応する共振周波数が一番高い
周波数で、その次に小さい寸法の気孔に対応する共振周
波数がその周波数の半分の周波数、順に、さらに半分の
周波数ごとに共振する吸音特性を有する。一番大きい寸
法の気孔に対応する共振周波数は一番低周波数である。
気孔の共振のＱは小さく、気孔の大きさに対応する吸音
特性はなだらかに減少するので、隣り合う寸法の共振に
よる吸音特性は、スタガーとなるので、気孔の外周寸法
を、倍、倍となる気孔を組み合わせて配列すると、高周
波数から低周波数までの広帯域で吸音特性の良好な吸音
ゴムが実現できる。このとき、外周寸法の大きな気孔は
支柱を有する気孔とする。By combining a plurality of pores having different outer diameters of 2 n (n: an integer) with different dimensions,
A sound absorption characteristic in which the resonance frequency corresponding to the pore with the smallest size is the highest frequency, and the resonance frequency corresponding to the pore with the next smallest size resonates at a frequency that is half that frequency, in that order, and at each half frequency. Have. The resonance frequency corresponding to the pore with the largest size is the lowest frequency.
Since the Q of the resonance of the pores is small and the sound absorption characteristics corresponding to the size of the pores are gradually reduced, the sound absorption characteristics due to the resonance of adjacent dimensions become a stagger, so the outer peripheral dimension of the pores is doubled or doubled. By arranging the pores in combination, it is possible to realize a sound absorbing rubber having a wide range of high to low frequencies and good sound absorbing characteristics. At this time, pores having a large outer peripheral dimension are pores having columns.
【００２４】例えば、製作の容易な円柱形の気孔の一例
として、直径を４ｍｍ、８ｍｍ，１６ｍｍ、３２ｍｍの
円柱形の気孔を封入した場合の一例を図３、図４に示
す。図３は、図４の一点鎖線ＩＩＩ上の吸音ゴム１６の
部分的断面図、図４は、図３の一点鎖線ＩＩ上の吸音ゴ
ム１６の平面図である。ゴム板１７中の気孔２１は直径
４ｍｍ、気孔２３は直径８ｍｍで外周寸法が小さいので
支柱がなく、気孔２５は直径１６ｍｍ、気孔２７は直径
３２ｍｍで外周寸法が大きいのでそれぞれ支柱２９、３
１を有する。For example, as an example of a cylindrical pore that is easy to manufacture, an example in which cylindrical pores having a diameter of 4 mm, 8 mm, 16 mm, and 32 mm are enclosed is shown in FIGS. 3 and 4. 3 is a partial cross-sectional view of the sound absorbing rubber 16 on the alternate long and short dash line III in FIG. 4, and FIG. 4 is a plan view of the sound absorbing rubber 16 on the alternate long and short dash line II in FIG. Since the pores 21 in the rubber plate 17 have a diameter of 4 mm, the pores 23 have a diameter of 8 mm and a small outer peripheral dimension, there is no column, and the pores 25 have a diameter of 16 mm and the pores 27 have a diameter of 32 mm and a large outer dimension, so that the columns 29 and 3 respectively.
Has 1.
【００２５】硬度約４５度の天然ゴム中の横波の音速を
約１００ｍ／ｓｅｃとすると前記４種類の各々の気孔に
対応する理論的な共振周波数は、それぞれ約１６ｋＨ
ｚ、８ｋＨｚ、４ｋＨｚ、２ｋＨｚとなる。それぞれの
共振特性は、なだらかな周波数特性を有するので、これ
ら４種類の寸法の気孔を封入した場合の吸音特性は、２
ｋＨｚ付近から１６ｋＨｚ付近までの広帯域で吸音特性
を有する吸音ゴムが実現できる。When the acoustic velocity of transverse waves in natural rubber having a hardness of about 45 degrees is about 100 m / sec, the theoretical resonance frequencies corresponding to the above-mentioned four types of pores are about 16 kHz, respectively.
z, 8 kHz, 4 kHz, 2 kHz. Since each resonance characteristic has a gentle frequency characteristic, the sound absorption characteristic when the pores of these four sizes are enclosed is 2
It is possible to realize a sound absorbing rubber having a sound absorbing characteristic in a wide band from around kHz to around 16 kHz.
【００２６】図３、図４では、寸法の異なる気孔を同じ
数として示しているが、各寸法の気孔の数は同一である
必要はなく、それぞれ異なる割合で封入してもよい。各
々の気孔の大きさに対応した各周波数領域において、各
気孔の数に対応した吸音特性を得ることができる。3 and 4, the same number of pores having different sizes is shown, but the number of pores having different sizes does not have to be the same and may be filled in different proportions. In each frequency region corresponding to the size of each pore, it is possible to obtain sound absorption characteristics corresponding to the number of each pore.
【００２７】また、図３、図４では、異なる寸法の気孔
を同一のゴム板中１７に配列した場合として示してある
が、同一のゴム板中に必要な、異なる寸法の気孔をすべ
て封入する必要はなく、１枚のゴム板中に同一の寸法の
気孔を封入し、気孔の寸法がゴム板間で異なるゴム板を
複数枚組み合わせ、全体として必要な寸法の気孔をすべ
て含むようにしても同様の効果が得られる。例えば、一
例として図５の部分的断面図に示すように、ゴム板３３
には一番小さい気孔４１を、ゴム板３５には２番目に小
さい気孔４３を、ゴム板３６には支柱４９を有する２番
目に大きい気孔４５を、ゴム板３７には支柱５１を有す
る一番大きい気孔４７を各々封入し、３３、３５、３
７、３９のゴム板を重ね合わせて吸音ゴム３０としても
同様の効果がある。Although FIGS. 3 and 4 show the case where the pores of different sizes are arranged in the same rubber plate 17, all the pores of different sizes required are enclosed in the same rubber plate. It is not necessary to fill the pores of the same size in one rubber plate, combine a plurality of rubber plates with different pore sizes between the rubber plates, and include all the pores of the required size as a whole. The effect is obtained. For example, as shown in the partial sectional view of FIG.
Has the smallest pores 41, the rubber plate 35 has the second smallest pores 43, the rubber plate 36 has the second largest pores 45 having columns 49, and the rubber plate 37 has the largest columns 51. Enclose large pores 47, 33, 35, 3
The same effect can be obtained by stacking the rubber plates 7 and 39 to form the sound absorbing rubber 30.
【００２８】また、ゴム板中に複数の異なる寸法の気孔
を組み合わせて封入し、複数の異なる寸法の気孔の組み
合わせが、ゴム板間で異なるゴム板を組み合わせても同
様の効果が得られる。例えば、一例として図６の部分的
断面図に示すように、ゴム板５３には一番小さい気孔４
１と２番目に小さい４３を、ゴム板５５には２番目に小
さい気孔４３と支柱４９を有する２番目に大きい気孔４
５を、ゴム板５７には一番小さい気孔４１と支柱５１を
有する一番大きい気孔４７を各々封入し、５３、５５、
５７の３枚のゴム板を重ね合わせて吸音ゴム４０として
も同様の効果がある。ここでは１枚のゴム板中に２種類
の大きさの気孔を封入した例で説明したが、１枚のゴム
板中に封入する気孔の大きさは、１種類でも、２種類で
も、３種類以上でもよい。また、同じ大きさの気孔を異
なるゴム板中に封入してもよいことは、いうまでもな
い。このような構造により、目的とする吸音特性にあわ
せて、異なった気孔を含むゴム板を選択して複数組み合
わせて目的を達成できる利点がある。Further, a plurality of pores having different sizes are combined and enclosed in the rubber plate, and the same effect can be obtained by combining the plurality of pores having different sizes with each other. For example, as shown in the partial sectional view of FIG. 6 as an example, the rubber plate 53 has the smallest pores 4
The first and second smallest pores 43, the rubber plate 55 has the second smallest pores 43, and the second largest pores 4 having struts 49.
5, the rubber plate 57 is filled with the smallest pores 41 and the largest pores 47 having the columns 51, 53, 55,
The same effect can be obtained by stacking the three rubber plates 57 to form the sound absorbing rubber 40. Here, the example in which two kinds of pores are sealed in one rubber plate has been described, but the size of the pores sealed in one rubber plate is one kind, two kinds, or three kinds. Or more. Needless to say, pores of the same size may be enclosed in different rubber plates. With such a structure, there is an advantage that a rubber plate having different pores can be selected and combined in plural in accordance with a desired sound absorption characteristic to achieve the purpose.
【００２９】図７および図８は、本発明の吸音ゴムの一
実施例の損失特性および吸音特性の実施例で、直径３ｍ
ｍ，６ｍｍ，１３ｍｍ，１６ｍｍの気孔を厚さ２ｍｍの
ゴム板に空け、その両面に厚さ２ｍｍのゴム板を張り合
わせた場合の測定結果である。白丸の曲線６０は、透過
損失、黒丸の曲線６２は反射損失である。FIGS. 7 and 8 show examples of loss characteristics and sound absorption characteristics of one embodiment of the sound absorbing rubber of the present invention, which has a diameter of 3 m.
It is a measurement result when the pores of m, 6 mm, 13 mm, and 16 mm are formed in a rubber plate having a thickness of 2 mm, and the rubber plates having a thickness of 2 mm are attached to both surfaces thereof. A white circle curve 60 is a transmission loss, and a black circle curve 62 is a reflection loss.
【００３０】図７の吸音率は次式で表される。 吸音率＝１−（透過率＋反射率） 図７の透過損失と反射損失の測定結果から吸音率を算出
し図８に示す。The sound absorption coefficient of FIG. 7 is expressed by the following equation. Sound absorption coefficient = 1- (transmittance + reflectance) The sound absorption coefficient is calculated from the measurement results of the transmission loss and the reflection loss in FIG. 7 and is shown in FIG.
【００３１】図９は、従来の吸音ゴムの反射特性の測定
結果の一例である。厚さ３ｍｍのゴム板に直径２ｍｍか
ら８ｍｍまでの気孔を設け、その両面に厚さ３ｍｍ，６
ｍｍ，および９ｍｍのゴム板を張り合わせて、ゴム板の
全厚が９ｍｍ，１５ｍｍ，および２１ｍｍの３通りの場
合の反射損失（ＥＲで表してある）の測定結果である
り、それぞれ曲線８０、８２、および８４で示してあ
る。（堀井 浩ほか：吸音楔の水圧特性の改善、海洋音
響学会講演論文集ｐｐ．１−２，１９９１年５月１７
日）。FIG. 9 shows an example of the measurement result of the reflection characteristic of the conventional sound absorbing rubber. A rubber plate with a thickness of 3 mm is provided with pores with a diameter of 2 mm to 8 mm, and both sides have a thickness of 3 mm, 6 mm.
mm and 9 mm rubber plates are pasted together, and the measurement results of the reflection loss (represented by ER) are shown when the total thickness of the rubber plates is 3 mm of 9 mm, 15 mm, and 21 mm. , And 84. (Hori Hori et al .: Improvement of water pressure characteristics of sound absorbing wedge, Proceedings of JSCE, pp.1-2, May 1991, 17)
Day).
【００３２】従来の吸音ゴムに比べて５ｋＨｚ以下での
吸音特性が著しく向上し、約１ｋＨｚから１０ｋＨｚま
での広帯域で吸音特性の良好な吸音ゴムが実現できた。Compared with the conventional sound absorbing rubber, the sound absorbing characteristic at 5 kHz or less is remarkably improved, and the sound absorbing rubber having a good sound absorbing characteristic in a wide band from about 1 kHz to 10 kHz can be realized.
【００３３】なお、気孔の共振のＱは小さく、気孔の大
きさに対応する吸音の周波数特性は、なだらかで帯域が
あるので、気孔の外周寸法比は、厳密に２n （ｎ：整
数）でなくてもよく、ほぼ倍、倍となる寸法であれば十
分目的は達成できる。Since the resonance Q of the pores is small and the frequency characteristic of sound absorption corresponding to the size of the pores has a smooth band, the outer peripheral dimension ratio of the pores is strictly 2 n (n: integer). It does not need to be provided, and the object can be sufficiently achieved as long as the dimension is approximately doubled.
【００３４】また、気孔の外周寸法比が２n （ｎ：整
数）以外の大きさの気孔を有していてもよい。また、気
孔の外周寸法比が２n （ｎ：整数）である気孔のうち、
ある寸法の気孔の代わりに、その寸法より少し大きい寸
法と、少し小さい寸法の大きさの異なる複数の気孔に分
けても同様の効果が得られる。Further, the outer peripheral size ratio of the pores may have pores having a size other than 2 n (n: integer). In addition, among the pores whose outer peripheral dimension ratio is 2 n (n: integer),
The same effect can be obtained by substituting a plurality of pores having a slightly larger size and a slightly smaller size instead of the pores having a certain size.
【００３５】ここでの説明ではゴム板は、図２に示すよ
うに矩形としたが、実際に実験水槽の壁などに使用する
場合には、任意の形状を組み合わせて使用しても同様の
効果がある。In the description here, the rubber plate has a rectangular shape as shown in FIG. 2, but when it is actually used as a wall of an experimental water tank or the like, the same effect can be obtained by combining arbitrary shapes. There is.
【００３６】また、水中で使用する場合について説明し
たが、空中で使用すれば広帯域の吸音特性を持つ良好な
吸音材として効果がある。Further, although the case of using in water has been described, it is effective as a good sound absorbing material having wide band sound absorbing characteristics when used in the air.
【００３７】また、振動を減衰する防振ゴムとして使用
すれば、減衰量の大きく、かつ広帯域の良好な防振ゴム
として効果がある。When it is used as a vibration isolating rubber that damps vibrations, it is effective as a good vibration isolating rubber having a large attenuation amount and a wide band.
【００３８】[0038]
【発明の効果】上述の説明で明らかなように、この発明
の吸音ゴムによれば、低周波領域まで良好に吸音する広
帯域の吸音特性を実現できるので、水中物体の表面をこ
の発明の吸音ゴムで覆うと反射特性を低周波域まで低減
でき、また無響水槽の壁に設置すると無響水槽の反射特
性を低周波数域まで低減できる効果がある。また、空中
での吸音材や防振ゴムとしても効果がある。As is apparent from the above description, according to the sound absorbing rubber of the present invention, it is possible to realize a wide band sound absorbing characteristic that absorbs sound well in the low frequency region. The effect of reducing the reflection characteristics of the anechoic aquarium to the low frequency range can be achieved by covering with a wall, and the reflection characteristics of the anechoic aquarium can be reduced to the low frequency range. It is also effective as a sound-absorbing material or vibration-proof rubber in the air.
【図１】この発明の吸音ゴムの一実施例の説明のための
断面図である。FIG. 1 is a sectional view for explaining an embodiment of a sound absorbing rubber of the present invention.
【図２】この発明の吸音ゴムの一実施例の説明のための
平面図である。FIG. 2 is a plan view for explaining one embodiment of the sound absorbing rubber of the present invention.
【図３】この発明の吸音ゴムの一実施例の断面図であ
る。FIG. 3 is a sectional view of an embodiment of the sound absorbing rubber of the present invention.
【図４】この発明の吸音ゴムの一実施例の断面図であ
る。FIG. 4 is a sectional view of an embodiment of the sound absorbing rubber of the present invention.
【図５】この発明の吸音ゴムの一実施例の断面図であ
る。FIG. 5 is a sectional view of an embodiment of the sound absorbing rubber of the present invention.
【図６】この発明の吸音ゴムの一実施例の断面図であ
る。FIG. 6 is a sectional view of an embodiment of the sound absorbing rubber of the present invention.
【図７】この発明の吸音ゴムの一実施例の測定データの
一例である。FIG. 7 is an example of measurement data of one embodiment of the sound absorbing rubber of the present invention.
【図８】この発明の吸音ゴムの一実施例の吸音特性測定
データの一例である。FIG. 8 is an example of sound absorption characteristic measurement data of an embodiment of the sound absorbing rubber of the present invention.
【図９】従来の吸音ゴムの反射特性測定データの一例で
ある。FIG. 9 is an example of reflection characteristic measurement data of a conventional sound absorbing rubber.
１０，１６，３０，４０：吸音ゴム １１，１７，３３，３５，３７，３９：吸音ゴム １３，２１，２３，２５，２７，４１，４３，４５，４
７：気孔 １５，２９，３１，４９，５１：支柱 ６０，６２：測定データ10, 16, 30, 40: Sound absorbing rubber 11, 17, 33, 35, 37, 39: Sound absorbing rubber 13, 21, 23, 25, 27, 41, 43, 45, 4
7: Porosity 15, 29, 31, 49, 51: Support 60, 62: Measurement data
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年５月１２日[Submission date] May 12, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００５[Name of item to be corrected] 0005
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００５】ゴム中に多数の気孔を封入した吸音ゴムの
構造は、気孔を封入した大きさの異なる楔形のゴムを組
合せている（Ｅ．Ｍｅｙｅｒほか、Ａｃｏｕｓｔｉｃ
ａ、Ｖｏｌ．１０，ｐｐ．２８１−２８７，１９６
０）。ゴム中に多数の気孔を封入した吸音ゴムの吸音機
構は気孔の共振振動によっている。ゴム中の微小の気孔
の共振周波数は気孔の形状に関係せず、気孔の体積に依
存することをＭｅｙｅｒは報告している。図１０はＭｅ
ｙｅｒが文献中に報告している図である（Ｍｅｙｅｒほ
か、Ｊ．Ａｃｏｕｓｔ．Ｓｏｃ．Ａｍ．３０．ｐｐ．１
１１６−１１２４，１９５８）。ゴム中に封入した球、
楕円、円筒および正方形の形状の気孔の共振周波数の測
定値（νｍａｘ）の逆数（縦軸）を気孔の体積の３乗根
（横軸）に対して図示している。この図より、ゴム中の
微小の気孔の共振周波数は気孔の形状に関係せず、気孔
の体積の３乗根に依存することを示している。The structure of a sound-absorbing rubber in which a large number of pores are enclosed in rubber is a combination of wedge-shaped rubbers in which pores are enclosed and having different sizes (E. Meyer et al., Acoustic).
a, Vol. 10, pp. 281-287,196
0). The sound absorbing mechanism of sound absorbing rubber in which a large number of pores are enclosed in rubber is based on the resonance vibration of the pores. Meyer reported that the resonance frequency of minute pores in rubber is not related to the shape of the pores but depends on the volume of the pores. Figure 10 is Me
It is the figure which yer has reported in the literature (Meyer et al., J.Acoust.Soc.Am.30.pp.1).
116-1124, 1958). Sphere enclosed in rubber,
The reciprocal (vertical axis) of the measured value (νmax) of the resonance frequency of the pores having an elliptical shape, a cylindrical shape, and a square shape is shown with respect to the cube root of the pore volume (horizontal axis). From this figure, it is shown that the resonance frequency of minute pores in rubber is not related to the shape of the pores but depends on the cube root of the volume of the pores.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００６[Correction target item name] 0006
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００６】従来の気孔を封入した吸音ゴムの構造は、
図１０の関係を応用すると共に、ゴムと気孔の混合体の
音響インピーダンスを水の音響インピーダンスに順次等
しくなるよう気孔の大きさと数とを決めている（Ｅ．
Ｇ．Ｒｉｃｈａｒｄｓｏｎ、Ｔｅｃｈｎｉｃａｌ Ａｓ
ｐｅｃｔｓ ｏｆ Ｓｏｕｎｄ ｐ．２８１ Ｅｌｓｅ
ｖｉｅｒ Ｐｕｂｌｉｓｈｉｎｇ Ｃｏｍｐａｎｙ Ａ
ｍｓｔｅｒｄａｍ−Ｎｅｗ Ｙｏｒｋ，１９５７）。例
えば、ゴム板に直径２〜８ｍｍ程度の円柱状の気孔を多
数個配列して設け、その両面にゴム板を張り合わせて、
ゴム板中に多数の気孔を封入している。吸音の周波数特
性はほぼ４〜５ｋＨｚ以上の高周波数で効果がある。そ
れ以下の低周波数領域まで吸音効果を広げるには、気孔
の直径を大きくする必要がある。The structure of the conventional sound-absorbing rubber in which pores are enclosed is
While applying the relationship of FIG. 10, the size and number of pores are determined so that the acoustic impedance of the rubber / pore mixture becomes equal to that of water sequentially (E.
G. Richardson, Technical As
pects of Sound p. 281 Else
vier Publishing Company A
msterdam-New York, 1957). For example, a large number of columnar pores having a diameter of about 2 to 8 mm are arranged on a rubber plate, and the rubber plates are attached to both sides thereof,
A large number of pores are enclosed in a rubber plate. The frequency characteristics of sound absorption are effective at high frequencies of approximately 4 to 5 kHz or higher. In order to extend the sound absorbing effect to the low frequency region below that, it is necessary to increase the diameter of the pores.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００７[Correction target item name] 0007
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００７】しかし、従来の吸音ゴムでは、ゴムの硬度
が低いのでゴム板中に外周寸法が８ｍｍ程度の大きさの
気孔の封入が限度であり、大きな外周寸法の気孔を封入
することは困難であった。従って、４〜５ｋＨｚ以下の
低周波数領域に於ても吸音の効果を有する吸音ゴムの実
現は困難であった（Ｅ．Ｍｅｙｅｒほか：Ａｃｏｕｓｔ
ｉｃａ、Ｖｏｌ．１０，ｐｐ．２８１−２８７，１９６
０、伊藤 豊ほか：気孔入りゴムの吸音特性、防衛庁技
報１８１号、ｐｐ．４９−５５、堀井 浩ほか：吸音く
さびの水圧特性の改善、海洋音響学会講演論文集ｐｐ．
１−２，１９９１年５月１７日）。そのため、２ｋＨｚ
程度の低周波数から１０ｋＨｚ以上の高周波数までの十
分な広帯域特性を有する吸音ゴムが得られないという欠
点があった。However, in the conventional sound absorbing rubber, since the hardness of the rubber is low, it is limited to fill the pores with a peripheral dimension of about 8 mm in the rubber plate, and it is difficult to fill the pores with a large peripheral dimension. there were. Therefore, it has been difficult to realize a sound absorbing rubber having a sound absorbing effect even in a low frequency region of 4 to 5 kHz or less (E. Meyer et al .: Acost
ica, Vol. 10, pp. 281-287,196
0, Yutaka Ito et al .: Sound absorption characteristics of rubber with pores, Defense Agency Technical Report 181, pp. 49-55, Hiroi Horii et al .: Improvement of water pressure characteristics of sound absorbing wedge, Proceedings of Ocean Acoustics Society, pp.
1-2, May 17, 1991). Therefore, 2 kHz
There is a drawback in that a sound absorbing rubber having a sufficient wide band characteristic from a low frequency of about 10 kHz to a high frequency of 10 kHz or more cannot be obtained.
【手続補正４】[Procedure amendment 4]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２３[Name of item to be corrected] 0023
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２３】気孔の外周寸法比が２n （ｎ：整数）とな
る複数の異なる寸法の気孔を組み合わせて封入すれば、
一番小さい寸法の気孔に対応する共振周波数が一番高い
周波数で、その次に小さい寸法の気孔に対応する共振周
波数がその周波数の半分の周波数である。以下順に、さ
らに半分の周波数ごとに共振する吸音特性を有する。一
番大きい寸法の気孔に対応する共振周波数は一番低周波
数である。気孔の共振のＱは小さく、気孔の大きさに対
応する吸音特性はなだらかに減少するので、隣り合う寸
法の共振による吸音特性は、スタガーとなるので、気孔
の外周寸法を、倍、倍となる気孔を組み合わせて配列す
ると、高周波数から低周波数までの広帯域で吸音特性の
良好な吸音ゴムが実現できる。このとき、外周寸法の大
きな気孔は支柱を有する気孔とする。By combining a plurality of pores having different outer diameters of 2 n (n: an integer) with different dimensions,
The resonance frequency corresponding to the pore of the smallest size is the highest frequency, and the resonance frequency corresponding to the pore of the next smallest size is half the frequency. In the following order, it further has a sound absorption characteristic that resonates for each half frequency. The resonance frequency corresponding to the pore with the largest size is the lowest frequency. Since the Q of the resonance of the pores is small and the sound absorption characteristics corresponding to the size of the pores are gradually reduced, the sound absorption characteristics due to the resonance of adjacent dimensions become a stagger, so the outer peripheral dimension of the pores is doubled or doubled. By arranging the pores in combination, it is possible to realize a sound absorbing rubber having a wide range of high to low frequencies and good sound absorbing characteristics. At this time, pores having a large outer peripheral dimension are pores having columns.
【手続補正５】[Procedure Amendment 5]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３０[Name of item to be corrected] 0030
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３０】図７の透過損失と反射損失の測定結果から
吸音率を算出し図８に示す。吸音率は次式で表される。 吸音率＝１−（透過率＋反射率）The sound absorption coefficient was calculated from the measurement results of the transmission loss and the reflection loss in FIG. 7 and is shown in FIG. The sound absorption coefficient is expressed by the following equation. Sound absorption rate = 1- (transmittance + reflectance)
【手続補正６】[Procedure correction 6]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３１[Correction target item name] 0031
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３１】図９は従来の吸音ゴムの反射損失特性の測
定結果の一例である。厚さ３ｍｍのゴム板に直径２ｍｍ
から８ｍｍまでの気孔を設け、その両面に厚さ３ｍｍ、
６ｍｍおよび９ｍｍのゴム板を貼り合わせて、ゴム板の
全厚が９ｍｍ、１５ｍｍおよび２１ｍｍの３通りの場合
について Ｔａｒｇｅｔ ｓｔｒｅｎｇｔｈ を測定し
た結果から反射損失（ＥＲで表してある）を求めて、そ
れぞれ曲線８０、８２および８４で示してある（堀井
浩ほか：吸音くさびの水圧特性の改善、海洋音響学会講
演論文集ｐｐ．１−２，１９９１年５月１７日）。FIG. 9 shows an example of the measurement result of the reflection loss characteristic of the conventional sound absorbing rubber. 2 mm diameter on a 3 mm thick rubber plate
To 8mm, and 3mm thick on both sides,
6 mm and 9 mm rubber plates were pasted together, and the reflection loss (expressed as ER) was calculated from the results of measuring the target strength for three cases where the total thickness of the rubber plates was 9 mm, 15 mm and 21 mm, and the curves were obtained. It is shown at 80, 82 and 84 (Horai
Hiro et al .: Improving the water pressure characteristics of a sound absorbing wedge, Proceedings of the Acoustical Society of Japan pp. 1-2, May 17, 1991).
【手続補正７】[Procedure Amendment 7]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】図１０[Name of item to be corrected] Fig. 10
【補正方法】追加[Correction method] Added
【補正内容】[Correction content]
【図１０】ゴム中の気孔の共振周波数の逆数と気孔の体
積の３乗根との関係を示すデータである。FIG. 10 is data showing the relationship between the reciprocal of the resonance frequency of the pores in the rubber and the cube root of the pore volume.
【手続補正８】[Procedure Amendment 8]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図８[Correction target item name] Figure 8
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図８】 [Figure 8]
【手続補正９】[Procedure Amendment 9]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図１０[Name of item to be corrected] Fig. 10
【補正方法】追加[Correction method] Added
【補正内容】[Correction content]
【図１０】 ─────────────────────────────────────────────────────
[Figure 10] ─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年９月２１日[Submission date] September 21, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３１[Correction target item name] 0031
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３１】図９は支柱が無い気孔が設けられている従
来の３種類の吸音ゴムの反射損失特性の測定結果の一例
である。厚さ３ｍｍの一枚のゴム板に直径２ｍｍ、４ｍ
ｍおよび８ｍｍの気孔を設け、このゴム板の両面に厚さ
３ｍｍのゴム板を貼り合わせて全厚が９ｍｍのものと、
６ｍｍのゴム板を貼り合わせて全厚が１５ｍｍのもの
と、および９ｍｍのゴム板を貼り合わせて全厚が２１ｍ
ｍのものと３通りの場合についてターゲット・ストレン
グス（Ｔａｒｇｅｔ ｓｔｒｅｎｇｔｈ）を測定した結
果から反射損失（ＥＲで表してある）を求めて、それぞ
れ曲線８０、８２および８４で示してある（堀井 浩ほ
か：吸音くさびの水圧特性の改善、海洋音響学会講演論
文集ｐｐ．１−２，１９９１年５月１７日）。図９から
も明らかなように、従来の吸音ゴムでは、約２ｋＨｚ以
下ではその反射損失が測定できず、また、透過損失はい
ずれの周波数でも測定できなかった。また、上述したこ
の発明の実施例では、使用したゴムシートに設けられた
気孔の直径は１３ｍｍと１６ｍｍであって、直径１２ｍ
ｍおよび２４ｍｍの気孔ではない。直径が２n ｍｍであ
るのが理想的ではあるが、直径が１３ｍｍ、１６ｍｍ、
１２ｍｍおよび２４ｍｍの気孔は、いずれも５ｋＨｚよ
りも低い周波数帯で反射損失または吸音率にピーク値を
与えるので、本来１２ｍｍおよび２４ｍｍであるべき気
孔の直径を１３ｍｍおよび１６ｍｍの直径の気孔として
も大した相違はなく、吸音ゴムの特性に支障は無い。図
１１は、この発明の吸音ゴムと従来の吸音ゴムとの相違
を説明するための反射損失−周波数特性をそれぞれ示す
図である。図１１において、図７に示した反射損失曲線
６２を曲線１００として示してあり、また、図９に示し
た反射損失曲線を曲線１０２として示してある。これら
曲線１００および１０２の比較から、４ｋＨｚ以下の周
波数帯域では、この発明の実施例の反射損失は従来のも
のよりも大きく、従って、この発明の吸音ゴムは従来の
吸音ゴムよりも優れていることがわかる。FIG. 9 shows an example of measurement results of reflection loss characteristics of three types of conventional sound absorbing rubbers provided with pores having no support. Diameter of 2mm and 4m on one rubber plate with thickness of 3mm
m and 8 mm pores are provided, and a rubber plate having a thickness of 3 mm is attached to both sides of the rubber plate to have a total thickness of 9 mm,
The total thickness is 15 mm with a 6 mm rubber plate attached, and the total thickness is 21 m with a 9 mm rubber plate attached.
The reflection loss (represented by ER) was calculated from the results of measuring the target strengths for m and three cases, and they are shown by curves 80, 82 and 84, respectively (Horii Hiro et al .: Improvement of water pressure characteristics of sound absorbing wedge, Proceedings of Ocean Acoustics Society, pp. 1-2, May 17, 1991). As is clear from FIG. 9, in the conventional sound absorbing rubber, its reflection loss could not be measured at about 2 kHz or less, and the transmission loss could not be measured at any frequency. Further, in the above-described embodiment of the present invention, the diameter of the pores provided in the used rubber sheet is 13 mm and 16 mm, and the diameter is 12 m.
Not m and 24 mm pores. Ideally the diameter is 2 n mm, but the diameter is 13 mm, 16 mm,
Since the 12 mm and 24 mm pores both give a peak value to the reflection loss or the sound absorption coefficient in the frequency band lower than 5 kHz, the diameters of the pores originally supposed to be 12 mm and 24 mm were also large as 13 mm and 16 mm diameter pores. There is no difference and the characteristics of the sound absorbing rubber are not affected. FIG. 11 is a diagram showing reflection loss-frequency characteristics for explaining the difference between the sound absorbing rubber of the present invention and the conventional sound absorbing rubber. 11, the reflection loss curve 62 shown in FIG. 7 is shown as a curve 100, and the reflection loss curve shown in FIG. 9 is shown as a curve 102. From the comparison of these curves 100 and 102, in the frequency band of 4 kHz or less, the reflection loss of the embodiment of the present invention is larger than that of the conventional one, so that the sound absorbing rubber of the present invention is superior to the conventional sound absorbing rubber. I understand.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】図１１[Name of item to be corrected] Figure 11
【補正方法】追加[Correction method] Added
【補正内容】[Correction content]
【図１１】図９に示した、支柱を有さない気孔が形成さ
れている従来の吸音ゴムの反射損失特性と、図７に示し
た、支柱を有する気孔が形成されているこの発明の吸音
ゴムの反射損失特性との相違を説明するためのグラフで
ある。11 is a reflection loss characteristic of a conventional sound absorbing rubber in which pores having no columns are formed as shown in FIG. 9 and sound absorption of the present invention in which pores having columns are formed as shown in FIG. It is a graph for explaining the difference with the reflection loss characteristic of rubber.
【手続補正３】[Procedure 3]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図１０[Name of item to be corrected] Fig. 10
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図１０】 [Figure 10]
【手続補正４】[Procedure amendment 4]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図１１[Name of item to be corrected] Figure 11
【補正方法】追加[Correction method] Added
【補正内容】[Correction content]
【図１１】 FIG. 11
Claims (4)
において、気孔の内部に気孔壁を支える支柱を有するこ
とを特徴とする吸音ゴム。1. A sound-absorbing rubber in which a large number of pores are enclosed in the rubber, wherein the sound-absorbing rubber is provided with pillars for supporting the pore walls inside the pores.
において、気孔の外周寸法比が２n （ｎ：整数）、 また
はほぼ２n となる複数の大きさの異なる気孔を封入して
成ることを特徴とする吸音ゴム。2. A sound-absorbing rubber in which a large number of pores are enclosed in rubber, wherein a plurality of pores of different sizes are enclosed such that the outer peripheral dimension ratio of the pores is 2 n (n: integer) or approximately 2 n. Sound absorbing rubber characterized by that.
支柱のない気孔と、気孔の外周寸法が異なる複数の大き
さで、かつ支柱を有する気孔とを封入したことを特徴と
する吸音ゴム。3. A sound-absorbing rubber, characterized in that a plurality of pore-free pores having different outer circumferential dimensions of pores and a plurality of pores having different circumferential dimensions of pores and having pillars are enclosed. .
上の複数の大きさの異なる気孔を封入した吸音ゴムを複
数複合して、複数複合したゴム全体の中で気孔の外周寸
法比が２n （ｎ：整数）または、 ほぼ２n となることを
特徴とする吸音ゴム。4. A plurality of sound-absorbing rubbers containing a plurality of pores having different sizes of one or two or more outer circumferences of the pores are compounded, and the ratio of the outer circumferences of the pores is 2 in the whole compounded rubber. n (n: integer) or almost 2 n .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5008166A JPH0769706B2 (en) | 1993-01-21 | 1993-01-21 | Sound absorbing rubber plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5008166A JPH0769706B2 (en) | 1993-01-21 | 1993-01-21 | Sound absorbing rubber plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06222778A true JPH06222778A (en) | 1994-08-12 |
| JPH0769706B2 JPH0769706B2 (en) | 1995-07-31 |
Family
ID=11685756
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5008166A Expired - Lifetime JPH0769706B2 (en) | 1993-01-21 | 1993-01-21 | Sound absorbing rubber plate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0769706B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08160965A (en) * | 1994-12-08 | 1996-06-21 | Tech Res & Dev Inst Of Japan Def Agency | Sound absorbing and shielding material |
| JP2004286808A (en) * | 2003-03-19 | 2004-10-14 | Mitsubishi Heavy Ind Ltd | Sound absorbing structure |
| JP2009080487A (en) * | 2008-10-21 | 2009-04-16 | Mitsubishi Heavy Ind Ltd | Underwater sound absorbing device |
| WO2013136909A1 (en) * | 2012-03-13 | 2013-09-19 | 株式会社 日立ハイテクノロジーズ | Soundproof cover for charged-particle beam device, and charged-particle beam device |
| JP2013541741A (en) * | 2010-11-09 | 2013-11-14 | カリフォルニア インスティチュート オブ テクノロジー | Acoustic suppression system and related method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS533242A (en) * | 1976-06-29 | 1978-01-12 | Nippon Telegr & Teleph Corp <Ntt> | Recording system |
| JPH02276629A (en) * | 1989-04-19 | 1990-11-13 | Hayakawa Rubber Co Ltd | Vibration-damping and soundproofing panel |
-
1993
- 1993-01-21 JP JP5008166A patent/JPH0769706B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS533242A (en) * | 1976-06-29 | 1978-01-12 | Nippon Telegr & Teleph Corp <Ntt> | Recording system |
| JPH02276629A (en) * | 1989-04-19 | 1990-11-13 | Hayakawa Rubber Co Ltd | Vibration-damping and soundproofing panel |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08160965A (en) * | 1994-12-08 | 1996-06-21 | Tech Res & Dev Inst Of Japan Def Agency | Sound absorbing and shielding material |
| JP2004286808A (en) * | 2003-03-19 | 2004-10-14 | Mitsubishi Heavy Ind Ltd | Sound absorbing structure |
| JP2009080487A (en) * | 2008-10-21 | 2009-04-16 | Mitsubishi Heavy Ind Ltd | Underwater sound absorbing device |
| JP2013541741A (en) * | 2010-11-09 | 2013-11-14 | カリフォルニア インスティチュート オブ テクノロジー | Acoustic suppression system and related method |
| WO2013136909A1 (en) * | 2012-03-13 | 2013-09-19 | 株式会社 日立ハイテクノロジーズ | Soundproof cover for charged-particle beam device, and charged-particle beam device |
| JP2013191333A (en) * | 2012-03-13 | 2013-09-26 | Hitachi High-Technologies Corp | Noise-proof cover for charged particle beam device and charged particle beam device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0769706B2 (en) | 1995-07-31 |
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