JPH0598926A - Low noise equipment - Google Patents
Low noise equipmentInfo
- Publication number
- JPH0598926A JPH0598926A JP3264516A JP26451691A JPH0598926A JP H0598926 A JPH0598926 A JP H0598926A JP 3264516 A JP3264516 A JP 3264516A JP 26451691 A JP26451691 A JP 26451691A JP H0598926 A JPH0598926 A JP H0598926A
- Authority
- JP
- Japan
- Prior art keywords
- noise
- opening surface
- sounding body
- sound
- equipment
- 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
- Exhaust Silencers (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、小形コンピュータや空
調機などに好適な低騒音機器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to low noise equipment suitable for small computers, air conditioners and the like.
【0002】[0002]
【従来の技術】従来、流体機械から発生する騒音の低減
に対して、流路に多孔質吸音材料を内張りした吸収型サ
イレンサや断面変化を利用したリアクティブ型サイレン
サ機器に装着する方法が広く使われている。しかし、流
体機械のような周波数の低い騒音を対象とする場合、機
器が大形となり、重量が増加する等の、改善に対する要
求が多い。2. Description of the Related Art Conventionally, in order to reduce noise generated from a fluid machine, a method of mounting it on an absorption silencer having a porous sound absorbing material lined in a flow path or a reactive silencer device utilizing a cross section change has been widely used. It is being appreciated. However, in the case of targeting low frequency noise such as fluid machinery, there are many demands for improvement such that the equipment becomes large and the weight increases.
【0003】一方、これに対して、別の方法として、古
くから提案されていた能動型消音装置即ち、音源からの
伝搬波に対して、逆位相の付加音を加え、音波干渉によ
って消音を強制的に生じさせる方法、すなわち、破壊的
消音方法が着目されつつある。On the other hand, as another method, an active silencer that has been proposed for a long time, that is, an additive sound having an opposite phase is added to a propagating wave from a sound source, and the silence is forced by sound wave interference. A method of generating noise, that is, a destructive muffling method is attracting attention.
【0004】能動型消音装置は電子デバイス,信号処理
技術等の急速な発達に伴って、最近様々な観点からの研
究成果が次々と発表されている。With the rapid development of electronic devices, signal processing technology, and the like, research results from various viewpoints have recently been announced one after another for the active silencer.
【0005】ところで、特開平2−261997 号公報に記載
の消音装置に示すように、発音体をダクト開口部の周囲
に環状に囲むようにして、音場のむらによる消音効果の
低下を抑制可能とする消音装置が公開されている。これ
には、能動的消音手段のみが示されている。By the way, as shown in the silencer disclosed in Japanese Unexamined Patent Publication No. 261997/1990, the sounding body is surrounded by a ring around the opening of the duct to suppress the reduction of the silencing effect due to the unevenness of the sound field. The device is open to the public. Only active muffling is shown.
【0006】[0006]
【発明が解決しようとする課題】一般に機器騒音の評価
位置は固定されないから、機器が収納された部屋内の何
れの位置も静粛でなければならないから、機器の開口面
からの放射騒音のエネルギを小さくしなければならな
い。そのため必然的に騒音の放射面、すなわち、開口面
の近傍に発音体を設ける必要がある。この場合、この消
音効果は、消音対象とする音波の波長に対する開口面と
発音体のそれぞれ中心軸間の距離の比に比例するから、
極力この距離が小さくなるように消音装置搭載機器の構
成を工夫しなければならないが、発音体が開口面を囲む
ように取り付ける方法では、開口面と発音体のそれぞれ
中心軸間の距離を低減しようとしても、発音体または開
口面を小さくするには、それぞれ低周波数での放射パワ
ーの低減や流速増加に伴う流体抵抗の増加を招くので、
効果的な消音ができない。また、機器開口面から放射さ
れる騒音は、流体機械の回転数と羽根枚数の積で決定さ
れる羽根音のような低い周波数成分の音と、羽根表面の
剥離に伴って発生する乱流音のような比較的周波数の高
い成分の音から構成されており、静粛な機器を実現する
には、低周波数から高周波数の幅広い音の低減が求めら
れるが、本質的に能動的消音手段のみでは、高い周波数
の音の消音効果は期待できない。Generally, since the evaluation position of the equipment noise is not fixed, any position in the room where the equipment is housed must be quiet. Therefore, the energy of the radiated noise from the opening surface of the equipment is reduced. Must be small. Therefore, it is inevitably necessary to provide the sounding body in the vicinity of the noise emission surface, that is, the opening surface. In this case, this silencing effect is proportional to the ratio of the distance between the central axes of the aperture and the sounding body to the wavelength of the sound wave to be silenced,
It is necessary to devise the structure of the device equipped with a silencer so that this distance will be as small as possible, but in the method of mounting the sounding body so as to surround the opening surface, try to reduce the distance between the opening surface and the center axis of the sounding body. Even so, reducing the size of the sounding body or the opening surface leads to a decrease in radiation power at low frequencies and an increase in fluid resistance due to an increase in flow velocity.
I cannot mute effectively. In addition, the noise radiated from the equipment opening surface is a low frequency component sound such as a blade noise determined by the product of the rotational speed of the fluid machine and the number of blades, and the turbulent sound generated by the separation of the blade surface. , Which is composed of relatively high-frequency component sounds, and it is necessary to reduce a wide range of sounds from low frequencies to high frequencies in order to realize quiet equipment, but it is essentially only active sound-deadening means. , High frequency sound muffling effect can not be expected.
【0007】本発明の目的は、機器開口面から放射され
る騒音を効果的に全周波数帯域にわたって低減するため
の消音装置を搭載した低騒音機器を提供することにあ
る。An object of the present invention is to provide a low noise device equipped with a silencer for effectively reducing the noise radiated from the device opening surface over the entire frequency band.
【0008】[0008]
【課題を解決するための手段】本発明は、上記の目的を
達成するために、騒音源の騒音信号または騒音信号と高
い相関をもつ信号をセンサによって検出し、この検出信
号を信号処理装置によって加工後、発音体から音として
発生することにより、騒音源からの音波と発音源からの
音波を音波干渉して消音を行う能動的消音装置を設けた
低騒音機器において、発音体の面積が開口面より広く、
かつ、発音体の中心軸と開口面の中心軸がほぼ等しく、
発音体は、開口面から一定の距離をおいて設けたことを
特徴とする。In order to achieve the above object, the present invention detects a noise signal of a noise source or a signal having a high correlation with a noise signal by a sensor, and the detected signal is detected by a signal processing device. After processing, a low-noise device equipped with an active muffling device that muffles sound waves from a noise source by interfering with sound waves from the sound source by generating sound as a sound Wider than the plane,
And, the central axis of the sounding body and the central axis of the opening surface are almost equal,
The sounding body is characterized by being provided at a constant distance from the opening surface.
【0009】[0009]
【作用】本発明は、発音体の中心軸と開口面の中心軸が
ほぼ等しく、発音体は、開口面から一定の距離をおいて
設けたので、開口面の騒音と発音体の音波はいずれも、
同一の指向性パターンにて機器筐体外側へ放射されるの
で、それぞれの音の振幅が等しく、位相を逆になるよう
に制御すれば、これらは完全に空間中でミキシングし、
破壊的干渉を起し、特に、比較的周波数の低い騒音に対
して、大巾低減し、この消音効果は周波数が高くなるほ
ど逆に小さくなる。一方、本発明の機器では、同時に発
音体の面積が開口面より広くなるように構成しているの
で、騒音源すなわち、流体機械からの騒音は、発音体の
周囲を回折して機器開口面から機器周囲に伝搬するが、
この時、回折による減音作用が生じ、能動的消音手法が
不得意とする高周波数ほど減音効果が増加する。In the present invention, since the central axis of the sounding body and the central axis of the opening surface are substantially equal and the sounding body is provided at a constant distance from the opening surface, the noise of the opening surface and the sound wave of the sounding body are both Also,
Since they are radiated to the outside of the equipment casing in the same directivity pattern, if they are controlled so that the amplitudes of the sounds are equal and the phases are reversed, they will be completely mixed in space,
Destructive interference is caused, and particularly, noise having a relatively low frequency is greatly reduced, and this silencing effect is decreased as the frequency is increased. On the other hand, in the device of the present invention, since the area of the sounding body is made larger than the opening surface at the same time, the noise source, that is, the noise from the fluid machine is diffracted around the sounding body and is emitted from the opening surface of the device. Propagates around the device,
At this time, a sound-reducing effect due to diffraction occurs, and the sound-reducing effect increases as the frequency becomes high, which the active sound-deadening method is not good at.
【0010】[0010]
【実施例】以下、図面に基づいて本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.
【0011】図1は本発明の一実施例に係る消音装置を
搭載した機器の構成を示す説明図である。この装置が従
来の装置と異なる点は、発音体の面積が開口面より広く
かつ、発音体の中心軸と開口面の中心軸がほぼ等しく、
発音体は、開口面から一定の距離をおいて設けられてい
る点にある。FIG. 1 is an explanatory view showing the configuration of a device equipped with a silencer according to an embodiment of the present invention. The difference between this device and the conventional device is that the area of the sounding body is wider than the opening surface, and the central axis of the sounding body and the central axis of the opening surface are almost equal.
The sounding body is provided at a certain distance from the opening surface.
【0012】以下、この消音装置の動作について説明す
る。機器1の発熱部2を冷却するために流体機械である
ファン3を設ける。これから発生された騒音は、筐体4
の内部を伝搬し、発熱体2を冷却後、発音体である圧電
型スピーカ5と筐体4間の音・流れの流路6を通り、筐
体開口部7から周囲に放射される。一方、流体機械3の
近傍に取り付けられた騒音検出用センサであるマイク8
の出力信号9は適応型信号処理装置10に入力される。
この信号をもとに、信号処理装置10は、第二のセンサ
である集音マイク11からの出力値が適応アルゴリズム
に従って、常に最小となるよう、ファン3からの騒音と
同振幅で逆位相の音波を発音体である圧電型スピーカ5
から放射するように適応型信号処理装置10内の係数を
調整する。The operation of this silencer will be described below. A fan 3 which is a fluid machine is provided to cool the heat generating portion 2 of the device 1. The noise generated from this is the case 4
After propagating through the inside of the housing, the heating element 2 is cooled, and then passes through the sound / flow channel 6 between the piezoelectric speaker 5 as the sounding body and the housing 4, and is radiated to the surroundings from the housing opening 7. On the other hand, the microphone 8 which is a noise detection sensor mounted near the fluid machine 3
The output signal 9 of is input to the adaptive signal processing device 10.
Based on this signal, the signal processing device 10 has the same amplitude as that of the noise from the fan 3 and an opposite phase so that the output value from the sound collecting microphone 11 which is the second sensor is always minimized according to the adaptive algorithm. Piezoelectric speaker 5 that produces sound waves
The coefficients in the adaptive signal processing device 10 are adjusted so as to radiate from.
【0013】ところで、圧電型スピーカ5は、機器筐体
開口部7の中心軸上でかつ、この開口部7からある一定
距離dだけ離して取付けられているから、開口面7から
のファン3の騒音と圧電型スピーカ5からの音波はいず
れも、同一の指向性パターンで機器1の筐体5の外側へ
放射されるので、それぞれの音の振幅が等しく、位相を
逆になるように制御すれば、これらは完全に空間中でミ
キシングし、破壊的干渉を起し、特に、比較的周波数の
低い騒音に対して、大巾低減し、この消音効果は周波数
が低くなるほど大きくなる。一方、本発明の機器では、
同時に発音体である圧電型スピーカ5の面積が開口面7
より広くなるように構成しているので、騒音源、すなわ
ち、流体機械3からの騒音は、圧電型スピーカ5の周囲
を回折して機器開口面7から機器1の周囲に伝搬する
が、この時、回折による減音作用が生じ、能動的消音手
法が不得意とする高周波数ほど減音効果が増加する。セ
ンサが、電源周波数の検出センサである場合には、この
周波数とその高調波成分の騒音が破壊的干渉によって消
音される。同様に、センサが、流体機械のごく近傍に設
けられた圧力脈動の検出センサである場合には、この周
波数とその高調波成分の騒音が破壊的干渉によって消音
される。図2は筐体に取り付けられた消音用発音体の構
成を示す本発明の他の実施例を示す。また低騒音機器の
開口面の周囲に、開口面を取り囲むように圧電型スピー
カ5bと5cを設けて構成すると、開口面7に加えて、
開口面7の周囲から、開口面7からの放射騒音を包み込
むように、消音用音波が放射できるので、音場にむらが
生ぜず、さらに各発音体トータルの振動面の面積を大き
くできるので低周波数帯域での音波放射パワーも増大す
る。これら総合された作用により、機器1の筐体4の外
側では、これらの波は、完全に破壊的干渉を起し、騒音
を大巾に激減できる。図1およば図2に示す実施例で
は、発音体に平面スピーカである圧電型スピーカ5を採
用している。これはスピーカの体積が小さいことから、
機器1の筐体4内の空間を効率良く利用できる利点を有
する。図3は他の実施例を示し、筐体に取り付けられた
消音用発音体の構成を示す。圧電型スピーカ5を筐体4
の外部に設けたもので、本実施例は本発明と同一の作用
と効果を示す。図4は他の実施例を示し、筐体に取り付
けられた消音用発音体の構成を示す。この実施例のよう
に、発音体は平面型にとらわれずスピーカボックス12
cに収納され、振動面12aはコーン状であり、アクチ
ュエータ12bで駆動される構造の動電型スピーカ12
であって、少なくとも開口面7の中心軸と同一軸上で筐
体4内に設けたスピーカであれば、音・流れ流路6を阻
害しないから、本発明と同一に作用し同一の効果が得ら
れる。さらに、図1及び図2では、発音体である圧電型
スピーカ5を筐体4の内部に設けているが、平面型スピ
ーカが開口面7とほぼ同一軸上であれば、筐体外部に設
けても本発明と同一に作用し、同一の効果が得られる。By the way, since the piezoelectric type speaker 5 is mounted on the central axis of the device housing opening 7 and at a certain distance d from the opening 7, the piezoelectric speaker 5 is attached to the fan 3 from the opening surface 7. Both the noise and the sound wave from the piezoelectric speaker 5 are radiated to the outside of the housing 5 of the device 1 in the same directivity pattern, so that the amplitudes of the sounds should be equal and the phases should be reversed. For example, they completely mix in space and cause destructive interference, which is greatly reduced, especially for relatively low-frequency noise, and this silencing effect becomes greater at lower frequencies. On the other hand, in the device of the present invention,
At the same time, the area of the piezoelectric speaker 5, which is the sounding body, is equal to the opening surface 7.
Since it is configured to be wider, the noise source, that is, the noise from the fluid machine 3 is diffracted around the piezoelectric speaker 5 and propagates from the device opening surface 7 to the device 1 at this time. The sound reduction effect due to the diffraction occurs, and the sound reduction effect increases as the frequency becomes high, which the active noise reduction method is not good at. When the sensor is a power supply frequency detection sensor, noise of this frequency and its harmonic components is silenced by destructive interference. Similarly, when the sensor is a pressure pulsation detection sensor provided in the immediate vicinity of the fluid machine, noise of this frequency and its harmonic component is silenced by destructive interference. FIG. 2 shows another embodiment of the present invention showing the configuration of the sound deadening body attached to the housing. Further, when the piezoelectric speakers 5b and 5c are provided around the opening surface of the low noise device so as to surround the opening surface, in addition to the opening surface 7,
Since the sound wave for silencing can be radiated from the periphery of the opening surface 7 so as to wrap the radiated noise from the opening surface 7, there is no unevenness in the sound field, and the total vibrating surface area of each sounding body can be increased, so that it is low. The acoustic radiation power in the frequency band also increases. Due to these combined actions, outside the housing 4 of the device 1, these waves cause completely destructive interference, and the noise can be drastically reduced. In the embodiment shown in FIGS. 1 and 2, a piezoelectric speaker 5 which is a flat speaker is adopted as a sounding body. This is because the volume of the speaker is small,
This has the advantage that the space inside the housing 4 of the device 1 can be used efficiently. FIG. 3 shows another embodiment and shows the structure of the sound deadening body attached to the housing. The piezoelectric speaker 5 is installed in the housing 4
Is provided outside of the above, and this embodiment exhibits the same operation and effect as the present invention. FIG. 4 shows another embodiment and shows the structure of a sound deadening body attached to a housing. As in this embodiment, the speaker box 12 is not limited to a flat speaker.
The electro-dynamic loudspeaker 12 has a structure in which the vibrating surface 12a is cone-shaped and is driven by the actuator 12b.
However, if the speaker is provided in the housing 4 at least on the same axis as the central axis of the opening surface 7, the sound / flow channel 6 is not hindered, and thus the same operation and the same effect as the present invention can be obtained. can get. Further, in FIGS. 1 and 2, the piezoelectric speaker 5, which is a sounding body, is provided inside the housing 4. However, if the planar speaker is substantially on the same axis as the opening surface 7, it is provided outside the housing. However, the same operation and the same effect as the present invention can be obtained.
【0014】[0014]
【発明の効果】騒音源の騒音信号または騒音信号と高い
相関をもつ信号をセンサによって検出し、この検出信号
を信号処理装置によって加工後、発音体から音として発
生することにより、騒音源からの音波と発音源からの音
波を音波干渉して消音を行う能動的消音装置を設けた低
騒音機器において、発音体の面積が開口面より広くか
つ、発音体の中心軸と開口面の中心軸がほぼ等しく、発
音体は、開口面から一定の距離をおいて設けたので、能
動的消音による比較的低い周波数の騒音低減と回折に伴
う高周波数騒音の低減が共に実現できる。その結果、低
い周波数から高い周波数迄、広帯域騒音が効率よく低減
でき、音が静かな能動的消音装置を搭載した低騒音機器
が実現できる。The noise signal of the noise source or the signal having a high correlation with the noise signal is detected by the sensor, and the detected signal is processed by the signal processing device and then generated as a sound from the sounding body. In a low-noise device equipped with an active muffling device that muffles sound waves by interfering with sound waves from a sound source, the area of the sounding body is wider than the opening surface, and the central axis of the sounding body and the central axis of the opening surface are Almost the same, the sounding body is provided at a constant distance from the opening surface, so that noise reduction at a relatively low frequency due to active noise reduction and reduction of high frequency noise due to diffraction can both be realized. As a result, broadband noise can be efficiently reduced from a low frequency to a high frequency, and a low-noise device equipped with an active silencer that is quiet can be realized.
【図1】本発明の一実施例に係る消音装置を適用した機
器の説明図。FIG. 1 is an explanatory diagram of a device to which a silencer according to an embodiment of the present invention is applied.
【図2】筐体に取り付けられた消音用発音体の構成を示
す本発明の他の実施例の説明図。FIG. 2 is an explanatory view of another embodiment of the present invention showing a configuration of a sound deadening body attached to a housing.
【図3】他の実施例を示し、筐体に取り付けられた消音
用発音体の説明図。FIG. 3 is an explanatory view of a sound deadening body attached to a housing according to another embodiment.
【図4】他の実施例を示し、筐体に取り付けられた消音
用発音体の説明図。FIG. 4 is an explanatory diagram of a sound deadening body attached to a housing according to another embodiment.
1…機器、2…発熱体、3…ファン、5…圧電型スピー
カ、6…音・流れ路、7…開口面、8…マイク、10…
適応型信号処理装置、11…集音マイク。1 ... Equipment, 2 ... Heating element, 3 ... Fan, 5 ... Piezoelectric speaker, 6 ... Sound / flow path, 7 ... Opening surface, 8 ... Microphone, 10 ...
Adaptive signal processor, 11 ... Sound collecting microphone.
Claims (1)
相関をもつ信号をセンサによって検出し、この検出信号
を信号処理装置によって加工後、発音体から音として発
生することにより、騒音源より機器内を伝搬し、機器開
口面から放射された音波と前記発音体からの音波を音波
干渉して消音を行う能動的消音装置を設けた低騒音機器
において、前記発音体の面積が前記機器開口面より広
く、前記発音体の中心軸と前記機器開口面の中心軸がほ
ぼ等しく、前記発音体は、前記機器開口面から一定の距
離をおいて設けたことを特徴とする低騒音機器。1. A device that detects a noise signal of a sound source or a signal having a high correlation with the noise signal by a sensor, processes the detection signal by a signal processing device, and then generates the sound from a sounding body to generate a sound from a noise source. In a low-noise device provided with an active muffling device that propagates through the inside of the device, the sound wave emitted from the device opening face and the sound wave from the sounding body interfere with each other, and the sounding body has an area of the device opening face. Wider, the central axis of the sounding body and the central axis of the device opening surface are substantially equal to each other, and the sounding member is provided at a constant distance from the device opening surface.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3264516A JP2961996B2 (en) | 1991-10-14 | 1991-10-14 | Low noise equipment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3264516A JP2961996B2 (en) | 1991-10-14 | 1991-10-14 | Low noise equipment |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0598926A true JPH0598926A (en) | 1993-04-20 |
JP2961996B2 JP2961996B2 (en) | 1999-10-12 |
Family
ID=17404336
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3264516A Expired - Fee Related JP2961996B2 (en) | 1991-10-14 | 1991-10-14 | Low noise equipment |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2961996B2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20030023062A (en) * | 2001-09-11 | 2003-03-19 | 주식회사 엘지이아이 | Outdoor-unit of airconditioner with speaker |
JP2006207508A (en) * | 2005-01-31 | 2006-08-10 | Yokohama National Univ | Fan noise reducing device and fan noise reducing method |
US7677354B2 (en) * | 2004-03-23 | 2010-03-16 | Sony Corporation | Electronic apparatus having speaker unit incorporated therein |
CN112218206A (en) * | 2020-09-28 | 2021-01-12 | 业泓科技(成都)有限公司 | Sound control method, device, equipment and medium based on film loudspeaker |
-
1991
- 1991-10-14 JP JP3264516A patent/JP2961996B2/en not_active Expired - Fee Related
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20030023062A (en) * | 2001-09-11 | 2003-03-19 | 주식회사 엘지이아이 | Outdoor-unit of airconditioner with speaker |
US7677354B2 (en) * | 2004-03-23 | 2010-03-16 | Sony Corporation | Electronic apparatus having speaker unit incorporated therein |
JP2006207508A (en) * | 2005-01-31 | 2006-08-10 | Yokohama National Univ | Fan noise reducing device and fan noise reducing method |
JP4690735B2 (en) * | 2005-01-31 | 2011-06-01 | 国立大学法人横浜国立大学 | Fan noise reduction device and fan noise reduction method |
CN112218206A (en) * | 2020-09-28 | 2021-01-12 | 业泓科技(成都)有限公司 | Sound control method, device, equipment and medium based on film loudspeaker |
CN112218206B (en) * | 2020-09-28 | 2022-07-19 | 业泓科技(成都)有限公司 | Sound control method, device, equipment and medium based on film loudspeaker |
Also Published As
Publication number | Publication date |
---|---|
JP2961996B2 (en) | 1999-10-12 |
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LAPS | Cancellation because of no payment of annual fees |