JPH06308969A - Hybrid type noise silencer - Google Patents
Hybrid type noise silencerInfo
- Publication number
- JPH06308969A JPH06308969A JP5094601A JP9460193A JPH06308969A JP H06308969 A JPH06308969 A JP H06308969A JP 5094601 A JP5094601 A JP 5094601A JP 9460193 A JP9460193 A JP 9460193A JP H06308969 A JPH06308969 A JP H06308969A
- Authority
- JP
- Japan
- Prior art keywords
- sound
- receiving plate
- noise
- sound receiving
- transmitted
- 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.)
- Pending
Links
Landscapes
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、騒音を減衰させるノイ
ズサイレンサ−に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise silencer that attenuates noise.
【０００２】[0002]
【従来の技術】従来、道路を走行する車両からの騒音、
航空機の飛行による騒音、あるいは変電所における電力
用変圧器から発生する騒音などが人々を悩ませているた
め、これらの騒音を減衰させるためには、防音壁を築い
たり、家屋の窓を二重にしたり変圧器を建物で密閉状に
囲むというような防音対策がとられている。2. Description of the Related Art Conventionally, noise from a vehicle traveling on a road,
Noise from airplane flight or noise generated from electric power transformers in substations is annoying to people.Therefore, in order to attenuate these noises, noise barriers should be built or windows of houses should be double-walled. The soundproofing measures are taken, for example, by enclosing the transformer in a sealed manner in a building.
【０００３】[0003]
【発明が解決しようとする課題】上記従来の騒音に対す
る防音対策によれば、防音壁、あるいは二重窓による防
音効果は十分ではなく、変圧器等を建物で密閉状に囲む
場合は、建物の建築費が高くなるという問題がある。そ
こで本発明では、電気的な手段で騒音を十分に、且つ安
価に減衰させることを解決すべき技術的課題とするもの
である。According to the above conventional soundproofing measures against noise, the soundproofing effect by the soundproof wall or the double window is not sufficient, and when the transformer or the like is enclosed in a building in a sealed manner, There is a problem that the construction cost becomes high. In view of this, the present invention provides a technical problem to be solved in which noise is sufficiently and inexpensively attenuated by electric means.
【０００４】[0004]
【課題を解決するための手段】上記課題解決のための技
術的手段は、ハイブリッド型ノイズサイレンサ−を、受
音面に外部からの音による音圧を受けたときその音圧に
応じた電圧を発生する圧電素子から成る受音板と、その
受音板から発生された前記電圧によって流れる電流を通
電させてその電流に応じたジュ−ル熱を発生させる電気
抵抗体と、前記受音板を透過した前記音を検出し、その
検出音に応じた信号を出力するセンサ−と、そのセンサ
−からの信号に基づいて前記受音板を透過した前記音の
位相と逆の位相で振幅が等しい音波を出力し、前記受音
板を透過した前記音を減衰させる音波出力手段とを備え
た構成にすることである。The technical means for solving the above-mentioned problems is to provide a hybrid noise silencer with a voltage corresponding to the sound pressure of a hybrid type noise silencer when the sound receiving surface receives the sound pressure by the sound from the outside. A sound receiving plate composed of a piezoelectric element for generating, an electric resistor for supplying a current flowing by the voltage generated from the sound receiving plate to generate jule heat corresponding to the current, and the sound receiving plate. A sensor that detects the transmitted sound and outputs a signal corresponding to the detected sound, and an amplitude equal to the phase of the sound that has passed through the sound receiving plate based on the signal from the sensor and in the opposite phase. And a sound wave output unit that outputs a sound wave and attenuates the sound transmitted through the sound receiving plate.
【０００５】[0005]
【作用】上記構成のハイブリッド型ノイズサイレンサ−
によれば、受音板の受音面に音発生源からの音の音圧が
印加されると、受音板はその音圧に応じた電圧を発生さ
せるため、同電圧に応じた電流が電気抵抗体に通電され
ることから電気抵抗体においてジュ−ル熱が発生される
ため、上記音によるエネルギ−が熱に変換され、受音板
を透過する音のエネルギ−が減衰される。この透過音が
センサ−により検出され、その検出音に応じた信号が出
力されると、音波出力手段はその信号に応じて透過音の
位相と逆の位相で振幅が等しい音波を出力し、透過音を
相殺するため発生源からの音は十分に減衰される。尚、
受音板及び電気抵抗体から成るパッシィブ型の音減衰手
段とセンサ−及び音波出力手段から成るアクティブ型の
音減衰手段とをカスケ−ド状に配設すれば音の減衰が更
に顕著になる。[Function] A hybrid type noise silencer having the above structure
According to this, when the sound pressure of the sound from the sound generation source is applied to the sound receiving surface of the sound receiving plate, the sound receiving plate generates a voltage according to the sound pressure, so that a current corresponding to the voltage is generated. Since the electric resistance is energized to generate Jule heat in the electric resistance, the energy due to the sound is converted into heat, and the energy of the sound transmitted through the sound receiving plate is attenuated. When this transmitted sound is detected by the sensor, and a signal corresponding to the detected sound is output, the sound wave output means outputs a sound wave having the same amplitude in a phase opposite to the phase of the transmitted sound according to the signal, and the transmitted sound is transmitted. The sound from the source is sufficiently attenuated to cancel the sound. still,
If the passive type sound attenuating means including the sound receiving plate and the electric resistor and the active type sound attenuating means including the sensor and the sound wave output means are arranged in a cascade manner, the sound attenuation becomes more remarkable.
【０００６】[0006]
【実施例】次に、本発明の実施例を図面を参照しながら
説明する。図１は、例えば道路を走行する車両の走行音
をビルの窓の部分で減衰させるため、その窓の部分に装
備するハイブリッド型ノイズサイレンサ−１の構成を示
したものである。図１に示すように、ビルの窓部には圧
電素子から成る受音板２が配設されており、道路を走行
する車両の走行音、即ち、図面上ではノイズとして示し
た音圧ＮＰを受音面２Ｓに受けたとき、その音圧に応じ
た電圧が発生する。そして受音板２の図面上、上下両端
部には端子２Ａ，２Ｂが設けられており、その端子２
Ａ，２Ｂ間に上記電圧が発生する。Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows the configuration of a hybrid noise silencer-1 installed in a window portion of a building, for example, in order to attenuate the running sound of a vehicle traveling on a road. As shown in FIG. 1, a sound receiving plate 2 made of a piezoelectric element is arranged in a window portion of a building, and a traveling sound of a vehicle traveling on a road, that is, a sound pressure NP shown as noise in the drawing is generated. When received by the sound receiving surface 2S, a voltage corresponding to the sound pressure is generated. In the drawing of the sound receiving plate 2, terminals 2A and 2B are provided at both upper and lower ends, respectively.
The above voltage is generated between A and 2B.
【０００７】上記端子２Ａ，２Ｂ間には抵抗３が接続さ
れている。尚、この抵抗３は大きく図示されているが、
実際には窓の視界を妨げない任意の位置に配設される一
方、抵抗３と端子２Ａ，２Ｂ間のリ−ド線４Ａ，４Ｂは
導電性の細い透明体で、受音板２の周縁部に沿って貼着
されている。従って、上記端子２Ａ，２Ｂ間に現れた電
圧は抵抗３に通電され、抵抗３でジュ−ル熱に変換され
るため、道路を走行する車両の走行音は熱に変換され、
受音板２を透過するノイズが減衰される。A resistor 3 is connected between the terminals 2A and 2B. Although the resistor 3 is shown in a large size,
In practice, the lead wires 4A and 4B between the resistor 3 and the terminals 2A and 2B are thin conductive conductive bodies and are arranged at arbitrary positions that do not obstruct the view of the window. It is attached along the section. Therefore, the voltage appearing between the terminals 2A and 2B is applied to the resistor 3 and converted into juule heat by the resistor 3, so that the running sound of the vehicle traveling on the road is converted into heat.
The noise transmitted through the sound receiving plate 2 is attenuated.
【０００８】受音板２の受音面２Ｓと反対面には、受音
板２を透過したノイズを検出し、その検出音に応じた信
号を出力する圧電セラミックスから成るセンサ−５が着
接されている。また、同センサ−５が着接されている受
音板２の面から僅かの空隙を介した位置にはスピ−カ６
が配設されている。尚、このスピ−カ６はスピ−カシン
ボルで図示しているが、実際には圧電セラミックスを用
いた平面スピ−カであり、数ミリメ−トルの厚みを有す
る平板状のものである。A sensor 5 made of piezoelectric ceramics is attached to the surface of the sound receiving plate 2 opposite to the sound receiving surface 2S, which detects noise transmitted through the sound receiving plate 2 and outputs a signal corresponding to the detected sound. Has been done. In addition, the speaker 6 is placed at a position with a slight gap from the surface of the sound receiving plate 2 to which the sensor 5 is attached.
Is provided. Although the speaker 6 is shown by a speaker symbol, it is actually a flat speaker using piezoelectric ceramics and is a flat plate having a thickness of several millimeters.
【０００９】上記センサ−５及びスピ−カ６は、音波出
力回路７に接続されている。この音波出力回路７は高速
演算素子、即ちディジタルシグナルプロセッサ（ＤＳ
Ｐ）を内蔵し、前記センサ−５からの信号をディジタル
化した信号をリアルタイムに処理したうえ受音板２を透
過したノイズのデ−タを瞬時に演算する。そして高速演
算素子は、そのデ−タに基づいて受音板２を透過した音
と逆位相で、振幅が等しい音波をスピ−カ６から出力さ
せるためのデ−タを演算したうえ、そのデ−タに基づい
た出力信号をスピ−カ６に通電する。その結果、スピ−
カ６からは受音板２を透過したノイズと逆位相で、振幅
が等しい音波が出力されるため、受音板２を透過したノ
イズがスピ−カ６により相殺され、ほぼゼロに減衰され
る。The sensor 5 and the speaker 6 are connected to a sound wave output circuit 7. The sound wave output circuit 7 is a high-speed arithmetic device, that is, a digital signal processor (DS).
P) is built in, the signal from the sensor 5 is digitized, the signal is processed in real time, and the data of the noise transmitted through the sound receiving plate 2 is instantly calculated. Based on the data, the high speed computing element computes data for causing the speaker 6 to output a sound wave having an opposite phase to the sound transmitted through the sound receiving plate 2 and having the same amplitude. -The speaker 6 is energized with an output signal based on the output signal. As a result,
Since the sound wave having a phase opposite to that of the noise transmitted through the sound receiving plate 2 and the same amplitude is output from the speaker 6, the noise transmitted through the sound receiving plate 2 is canceled by the speaker 6 and attenuated to almost zero. .
【００１０】尚、受音板２と抵抗３から成るノイズ減衰
部は、受動的にノイズを減衰するものであるためパッシ
ブサイレンサ−を構成する一方、センサ−５、スピ−カ
６及び音波出力回路７から成るノイズ減衰部は、能動的
にノイズを減衰するものであるためアクティブサイレン
サ−を構成している。Since the noise attenuating section comprising the sound receiving plate 2 and the resistor 3 passively attenuates noise, it constitutes a passive silencer, while the sensor 5, the speaker 6 and the sound wave output circuit are provided. The noise attenuator 7 is an active silencer because it actively attenuates noise.
【００１１】上記ノイズ減衰作用から明らかなように、
受音板２と抵抗３から成るパッシブサイレンサ−及びセ
ンサ−５、スピ−カ６、音波出力回路７から成るアクテ
ィブサイレンサ−をカスケ−ド接続すれば、より効果的
にノイズを減衰させることができる。As is clear from the above noise attenuation action,
If the passive silencer composed of the sound receiving plate 2 and the resistor 3 and the active silencer composed of the sensor 5, the speaker 6, and the sound wave output circuit 7 are cascade-connected, the noise can be attenuated more effectively. .
【００１２】次に、上記のような構成のハイブリッド型
ノイズサイレンサ−１を変電所の電力用変圧器から発生
する騒音を低減させるための騒音低減用として用いた応
用例について説明する。一般に、電力用変圧器１１は、
商用周波数の５０Ｈｚもしくは６０Ｈｚの強電流が通電
されているため、１００Ｈｚもしくは１２０Ｈｚの周期
で電磁力による鉄心及び巻線の振動が発生し、この鉄心
の振動が騒音となって変電所の周囲に伝播されるため、
環境対策上、防音が必要である。Next, a description will be given of an application example in which the hybrid noise silencer-1 having the above-mentioned configuration is used for noise reduction for reducing noise generated from the power transformer of the substation. In general, the power transformer 11
Since a strong current of commercial frequency 50 Hz or 60 Hz is applied, vibration of the iron core and windings occurs due to electromagnetic force at a cycle of 100 Hz or 120 Hz, and the vibration of the iron core becomes noise and propagates around the substation. Because
Soundproofing is necessary for environmental protection.
【００１３】図２は、電力用変圧器１１の上面部及び側
面部を囲むようにハイブリッド型ノイズサイレンサ−１
を配設した断面図である。図２に示すように、電力用変
圧器１１の上面部及び側面部には、ハイブリッド型ノイ
ズサイレンサ−１を構成する前記受音板２と抵抗３から
成る複数のパッシブサイレンサ−が密閉状に配設されて
いる。そして各受音板２の受音面と反対の面には、アク
ティブサイレンサ−を構成する前記センサ−５が着接さ
れ、更に各センサ−５に対応して前記スピ−カ６が配設
されている。尚、受音板２を透過した音と逆位相で、振
幅が等しい音波をスピ−カ６から出力する前記音波出力
回路７は図示していない。また、風雨及び太陽光等から
上記各ハイブリッド型ノイズサイレンサ−１を防御する
ため、上面部及び側面部にカバ−部材１２が配置されて
いる。FIG. 2 shows a hybrid noise silencer-1 which surrounds the upper and side surfaces of the power transformer 11.
It is sectional drawing which arranged. As shown in FIG. 2, a plurality of passive silencers composed of the sound receiving plate 2 and the resistor 3 forming the hybrid noise silencer-1 are hermetically arranged on the upper surface portion and the side surface portion of the power transformer 11. It is set up. The sensor 5 constituting an active silencer is attached to the surface of each sound receiving plate 2 opposite to the sound receiving surface, and the speaker 6 is arranged corresponding to each sensor 5. ing. The sound wave output circuit 7 for outputting a sound wave from the speaker 6 having a phase opposite to that of the sound transmitted through the sound receiving plate 2 and having the same amplitude is not shown. Further, a cover member 12 is arranged on the upper surface portion and the side surface portion in order to protect each of the hybrid noise silencers-1 from wind and rain and sunlight.
【００１４】以上のように構成された電力用変圧器騒音
減衰用の各ハイブリッド型ノイズサイレンサ−１におい
て、電力用変圧器１１から発生した騒音の音圧が、各ハ
イブリッド型ノイズサイレンサ−１の受音板２の受音面
２Ｓに印加されると、各受音板２の前記端子２Ａ，２Ｂ
間に騒音の音圧に対応した電圧が発生するため、各端子
２Ａ，２Ｂ間に接続された抵抗３に電流が通電され、各
抵抗３でジュ−ル熱に変換されるため、電力用変圧器１
１から発生した騒音は熱に変換され、各受音板２を透過
する騒音が減衰される。In each of the hybrid noise silencer-1 for noise attenuation of the power transformer configured as described above, the sound pressure of the noise generated from the power transformer 11 is received by each hybrid noise silencer-1. When applied to the sound receiving surface 2S of the sound receiving plate 2, the terminals 2A, 2B of each sound receiving plate 2 are applied.
Since a voltage corresponding to the sound pressure of noise is generated between the terminals, a current is passed through the resistors 3 connected between the terminals 2A and 2B, and the resistors 3 are converted into jule heat. Bowl 1
The noise generated from 1 is converted into heat, and the noise transmitted through each sound receiving plate 2 is attenuated.
【００１５】各受音板２を透過した騒音は、前記各セン
サ−５で検出され、各検出信号が音波出力回路７に入力
されると、音波出力回路７に内蔵された前記ディジタル
シグナルプロセッサは、各センサ−５からの信号をディ
ジタル化した信号をリアルタイムに処理したうえ受音板
２を透過した騒音デ−タを瞬時に演算する。そしてその
騒音デ−タに基づいて受音板２を透過した騒音と逆位相
で、振幅が等しい音波をスピ−カ６から出力させるため
のデ−タを演算したうえ、そのデ−タに基づいた出力信
号をスピ−カ６に通電する。その結果、スピ−カ６から
は受音板２を透過した騒音と逆位相で、振幅が等しい音
波が出力されるため、受音板２を透過した騒音はスピ−
カ６から出力された上記音波により相殺される。The noise transmitted through each sound receiving plate 2 is detected by each sensor-5, and when each detection signal is input to the sound wave output circuit 7, the digital signal processor incorporated in the sound wave output circuit 7 , A signal obtained by digitizing the signal from each sensor 5 is processed in real time, and the noise data transmitted through the sound receiving plate 2 is instantly calculated. Then, based on the noise data, the data for causing the speaker 6 to output the sound wave having the same phase as the noise transmitted through the sound receiving plate 2 but having the opposite phase to the noise is calculated. The output signal is applied to the speaker 6. As a result, a sound wave having a phase opposite to that of the noise transmitted through the sound receiving plate 2 and having the same amplitude is output from the speaker 6, so that the noise transmitted through the sound receiving plate 2 is sped up.
The sound waves output from the mosquito 6 cancel each other out.
【００１６】以上のように電力用変圧器１１から発生し
た騒音は、電力用変圧器１１の上面部及び側面部に配設
された各ハイブリッド型ノイズサイレンサ−１により減
衰されるため、変電所の敷地境界における騒音を極めて
低レベルに低減することができる。As described above, the noise generated from the power transformer 11 is attenuated by the hybrid noise silencers-1 provided on the upper surface and the side surface of the power transformer 11, so that the noise of the substation is reduced. Noise at the site boundary can be reduced to an extremely low level.
【００１７】[0017]
【発明の効果】以上のように本発明によれば、受音板の
受音面にノイズ発生源からの音の音圧が印加されると、
受音板はその音圧に応じた電圧を発生するため、その電
圧は電気抵抗体に印加されることから同電圧に応じた電
流が電気抵抗体に通電され、その電気抵抗体においてジ
ュ−ル熱が発生されると、音のエネルギ−が熱に変換さ
れるため、受音板を透過する音のエネルギ−が減衰さ
れ、更に、この透過音がセンサ−により検出され、検出
音に応じた信号が出力されると、音波出力手段はその信
号に応じて透過音の位相と逆の位相で振幅が等しい音波
を出力し、透過音を相殺するため、発生源からのノイズ
を十分に減衰することができるという効果がある。As described above, according to the present invention, when the sound pressure of the sound from the noise source is applied to the sound receiving surface of the sound receiving plate,
Since the sound receiving plate generates a voltage according to its sound pressure, the voltage is applied to the electric resistor, so that a current corresponding to the same voltage is applied to the electric resistor, and the electric resistor has a jewel. When heat is generated, the energy of the sound is converted into heat, so the energy of the sound that passes through the sound receiving plate is attenuated, and this transmitted sound is detected by the sensor, and the detected sound responds to the detected sound. When a signal is output, the sound wave output means outputs a sound wave having the same phase and a phase opposite to that of the transmitted sound according to the signal, and cancels the transmitted sound, so that the noise from the source is sufficiently attenuated. The effect is that you can.
【図１】本発明の実施例の構成を示した側面図である。FIG. 1 is a side view showing a configuration of an exemplary embodiment of the present invention.
【図２】ハイブリッド型ノイズサイレンサ−の応用例を
示した断面図である。FIG. 2 is a sectional view showing an application example of a hybrid noise silencer.
１ ハイブリッド型ノイズサイレンサ− ２ 受音板 ２Ｓ 受音面 ３ 抵抗 ５ センサ− ６ スピ−カ ７ 音波出力回路 1 Hybrid type noise silencer 2 Sound receiving plate 2S Sound receiving surface 3 Resistance 5 Sensor 6 Speaker 7 Sound wave output circuit
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中村 光一 愛知県海部郡蟹江町大字蟹江新田字与太郎 124番地の５ (72)発明者 松村 司郎 愛知県知多市つつじが丘３−８−13 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Nakamura, Koichi Nakamura, Aichi prefecture, Kanie-cho, Daiji, Kanie, Shinta, No. 124, Yotaro 5 (72) Inventor, Shiro Matsumura, 3-8-13 Azajigaoka, Chita city, Aichi prefecture
Claims (2)
たときその音圧に応じた電圧を発生する圧電素子から成
る受音板と、その受音板から発生された前記電圧によっ
て流れる電流を通電させてその電流に応じたジュ−ル熱
を発生させる電気抵抗体と、前記受音板を透過した前記
音を検出し、その検出音に応じた信号を出力するセンサ
−と、そのセンサ−からの信号に基づいて前記受音板を
透過した前記音の位相と逆の位相で振幅が等しい音波を
出力し、前記受音板を透過した前記音を減衰させる音波
出力手段とを備えたことを特徴とするハイブリッド型ノ
イズサイレンサ−。1. A sound receiving plate composed of a piezoelectric element that generates a voltage corresponding to the sound pressure of the sound receiving surface when the sound pressure is generated by an external sound, and the voltage generated from the sound receiving plate. An electric resistor that energizes a flowing current to generate jule heat corresponding to the current, a sensor that detects the sound transmitted through the sound receiving plate, and outputs a signal corresponding to the detected sound, Based on a signal from the sensor, a sound wave output unit that outputs a sound wave having the same amplitude in a phase opposite to the phase of the sound transmitted through the sound receiving plate and attenuates the sound transmitted through the sound receiving plate. A hybrid noise silencer that is equipped with.
ブ型音減衰手段とセンサ−及び音波出力手段から成るア
クティブ型音減衰手段とをカスケ−ド状に配設したこと
を特徴とするハイブリッド型ノイズサイレンサ−。2. A hybrid type in which a passive type sound attenuating means composed of a sound receiving plate and an electric resistor and an active type sound attenuating means consisting of a sensor and a sound wave output means are arranged in a cascade form. Noise silencer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5094601A JPH06308969A (en) | 1993-04-21 | 1993-04-21 | Hybrid type noise silencer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5094601A JPH06308969A (en) | 1993-04-21 | 1993-04-21 | Hybrid type noise silencer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06308969A true JPH06308969A (en) | 1994-11-04 |
Family
ID=14114783
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5094601A Pending JPH06308969A (en) | 1993-04-21 | 1993-04-21 | Hybrid type noise silencer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06308969A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR970017932A (en) * | 1995-09-28 | 1997-04-30 | 로더리히 네테부쉬; 롤프 옴케 | Apparatus and Method for Processing Semiconductor Devices |
| JPH11242488A (en) * | 1998-02-26 | 1999-09-07 | Toshiba Corp | Sound insulating device |
| CN102479503A (en) * | 2010-11-25 | 2012-05-30 | 中原工学院 | Broadband active silencer for automobile |
| CN112053674A (en) * | 2020-09-15 | 2020-12-08 | 中国科学院合肥物质科学研究院 | Combined micro-perforated plate sound absorber structure based on piezoelectric material and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58166177A (en) * | 1982-03-26 | 1983-10-01 | Ikeda Denki:Kk | Changeover valve apparatus for use in solar-heat-utilizing water heater |
| JPS647797A (en) * | 1987-06-30 | 1989-01-11 | Bridgestone Corp | Sound insulation device |
| JPH0329997A (en) * | 1989-06-28 | 1991-02-07 | Idemitsu Kosan Co Ltd | Sound reducing body |
| JPH041914A (en) * | 1990-04-19 | 1992-01-07 | Fuji Photo Film Co Ltd | Magnetic recording medium |
-
1993
- 1993-04-21 JP JP5094601A patent/JPH06308969A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58166177A (en) * | 1982-03-26 | 1983-10-01 | Ikeda Denki:Kk | Changeover valve apparatus for use in solar-heat-utilizing water heater |
| JPS647797A (en) * | 1987-06-30 | 1989-01-11 | Bridgestone Corp | Sound insulation device |
| JPH0329997A (en) * | 1989-06-28 | 1991-02-07 | Idemitsu Kosan Co Ltd | Sound reducing body |
| JPH041914A (en) * | 1990-04-19 | 1992-01-07 | Fuji Photo Film Co Ltd | Magnetic recording medium |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR970017932A (en) * | 1995-09-28 | 1997-04-30 | 로더리히 네테부쉬; 롤프 옴케 | Apparatus and Method for Processing Semiconductor Devices |
| JPH11242488A (en) * | 1998-02-26 | 1999-09-07 | Toshiba Corp | Sound insulating device |
| CN102479503A (en) * | 2010-11-25 | 2012-05-30 | 中原工学院 | Broadband active silencer for automobile |
| CN112053674A (en) * | 2020-09-15 | 2020-12-08 | 中国科学院合肥物质科学研究院 | Combined micro-perforated plate sound absorber structure based on piezoelectric material and preparation method thereof |
| CN112053674B (en) * | 2020-09-15 | 2023-09-22 | 中国科学院合肥物质科学研究院 | Combined microperforated panel sound absorber structure based on piezoelectric material and preparation method thereof |
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