JPH05257483A - Active silencer - Google Patents
Active silencerInfo
- Publication number
- JPH05257483A JPH05257483A JP4058284A JP5828492A JPH05257483A JP H05257483 A JPH05257483 A JP H05257483A JP 4058284 A JP4058284 A JP 4058284A JP 5828492 A JP5828492 A JP 5828492A JP H05257483 A JPH05257483 A JP H05257483A
- Authority
- JP
- Japan
- Prior art keywords
- sound
- duct
- pipe
- sound source
- heat insulating
- 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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/06—Silencing apparatus characterised by method of silencing by using interference effect
- F01N1/065—Silencing apparatus characterised by method of silencing by using interference effect by using an active noise source, e.g. speakers
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Silencers (AREA)
- Duct Arrangements (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、エンジンや送風機のよ
うな、高温ガスの排気ダクトから発生する騒音を消音す
る能動的消音装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active muffler for silencing noise generated from a hot gas exhaust duct such as an engine or a blower.
【０００２】[0002]
【従来の技術】騒音を消音するための装置として、特開
昭６２−２０６２１２号公報などに開示された能動的消
音装置があり、図１０はこれら従来の能動的消音装置を
示す概略構成図である。能動的消音装置は、一般に、一
次音源１からの騒音をダクト２に通し、ダクト２の途中
で一次音源１による音量を音量検出マイク６で検出し、
検出した信号を信号処理回路４で加工し、これを基に一
次音源１の騒音と逆位相で同振幅の音を二次音源として
のスピーカ３から放射し、一次音源１の騒音をスピーカ
３の音と干渉させて消音するもので、これによってダク
ト２の出口の音量検出マイク５で検出する音を最小にし
ようとするものである。2. Description of the Related Art As a device for silencing noise, there is an active silencing device disclosed in JP-A-62-206212 and the like. FIG. 10 is a schematic configuration diagram showing these conventional silencing devices. is there. In general, an active silencer passes the noise from the primary sound source 1 through the duct 2, and detects the volume of the primary sound source 1 in the middle of the duct 2 with the volume detection microphone 6.
The detected signal is processed by the signal processing circuit 4, and based on this, a sound having the same amplitude as the noise of the primary sound source 1 but having the opposite phase is radiated from the speaker 3 as the secondary sound source, and the noise of the primary sound source 1 is output from the speaker 3. The sound is interfering with the sound to be muted, so that the sound detected by the volume detection microphone 5 at the exit of the duct 2 is minimized.
【０００３】この能動的消音装置を、高温ガスが流れる
エンジンや送風機のダクトに適用する場合には、スピー
カ３や音量検出マイク５、６を熱から守り、かつスピー
カ３の出力不足を補うために、図１０のようにこれらを
ダクト２の出口に設けたり、耐熱性のあるスピーカ３や
音量検出マイク５，６を用いるなどの対策が講じられて
いた。When this active silencer is applied to a duct of an engine or a blower in which high temperature gas flows, in order to protect the speaker 3 and the volume detecting microphones 5 and 6 from heat and to supplement the output shortage of the speaker 3. As shown in FIG. 10, measures have been taken such as providing them at the outlet of the duct 2 or using a heat-resistant speaker 3 and volume detection microphones 5 and 6.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、二次音
源や音量検出マイクをダクトの出口に設けるのは、その
設置場所が限定されるため、施工やメンテナンスに困難
な場合を生じたり、雨や風に対する特別の対策が必要と
なる。また、ダクトの外で音の干渉が行われることにな
り、減音効果に指向性が生じる等の課題があった。本発
明は、これらの課題を解決して、安価で効果的な能動的
消音装置を提供することを目的とする。However, the installation of the secondary sound source and the volume detection microphone at the outlet of the duct limits the installation location, which may cause difficulty in construction and maintenance, rain and wind. Special measures against In addition, there is a problem that sound interference occurs outside the duct, and the sound reduction effect has directivity. It is an object of the present invention to solve these problems and provide an inexpensive and effective active silencer.
【０００５】[0005]
【課題を解決するための手段】第１の発明は、一次音源
と、一次音源から発せられる音波を伝搬するダクトと、
音量を検出する音量検出センサと、一次音源から発せら
れる音波と逆位相で同振幅の音波を放射する二次音源と
を備えた能動的消音装置において、音を通過させ断熱効
果を有する音透過断熱体をダクトに設け、この音透過断
熱体に前記二次音源と音量検出センサを設置したもので
ある。A first invention is a primary sound source, and a duct for propagating a sound wave emitted from the primary sound source.
In a sound deadening device including a sound volume detection sensor for detecting a sound volume and a secondary sound source that emits a sound wave having the same amplitude as that of a sound wave emitted from a primary sound source, a sound transmission adiabatic that allows sound to pass and has a heat insulating effect. The body is provided in a duct, and the secondary sound source and the volume detection sensor are installed in the sound transmission heat insulating body.
【０００６】第２の発明は、第１の発明の音透過断熱体
を、複数のパイプを平行にして一端をダクトに固定した
パイプ構造物とし、ダクトと反対側のパイプ端部に二次
音源と音量検出センサを設置したものである。A second invention is a pipe structure in which a plurality of pipes are parallel to each other and one end is fixed to a duct, and the secondary sound source is provided at an end of the pipe opposite to the duct. And a volume detection sensor is installed.
【０００７】第３の発明は、第２の発明の音透過断熱体
を、周囲を囲った箱体にこの箱体を貫通する複数のパイ
プを配したパイプ構造物とし、このパイプ構造物のパイ
プと平行な箱体の一面を前記ダクトに固定し、ダクトと
反対側の箱体面に二次音源と音量検出センサを設置した
ものである。A third aspect of the present invention is a pipe structure in which the sound-transmitting heat insulating body of the second aspect is arranged in a box body surrounding the box body, and a plurality of pipes penetrating the box body are arranged. One side of the box parallel to the above is fixed to the duct, and the secondary sound source and the volume detection sensor are installed on the side of the box opposite to the duct.
【０００８】第４の発明は、第２、第３のパイプ構造物
のパイプ総断面積又はパイプ長又はパイプ総断面積及び
パイプ長を変更可能としたものである。A fourth aspect of the present invention makes it possible to change the total pipe cross-sectional area or pipe length of the second and third pipe structures or the total pipe cross-sectional area and pipe length.
【０００９】[0009]
【作用】第１の発明においては、音透過断熱体が、ダク
トと二次音源及び音量検出センサとの間で、熱を遮断
し、音を通過させる。In the first aspect of the present invention, the sound transmitting heat insulating body blocks heat between the duct and the secondary sound source and the sound volume detecting sensor, and allows sound to pass therethrough.
【００１０】第２の発明においては、パイプ構造物のパ
イプ内部を音が通過し、パイプ外部が外気にさらされて
パイプ構造物が冷却される。In the second aspect of the invention, the sound passes through the inside of the pipe of the pipe structure, the outside of the pipe is exposed to the outside air, and the pipe structure is cooled.
【００１１】第３の発明においては、パイプ構造物のパ
イプ外部を音が通過し、パイプ内部が外気にさらされて
パイプ構造物が冷却される。In the third aspect of the invention, the sound passes through the outside of the pipe of the pipe structure, the inside of the pipe is exposed to the outside air, and the pipe structure is cooled.
【００１２】第４の発明においては、パイプ総断面積又
はパイプ長又はパイプ総断面積及びパイプ長を変更する
ことにより、特定の周波数で二次音源の音圧レベルを増
大させることができる。In the fourth aspect of the invention, the sound pressure level of the secondary sound source can be increased at a specific frequency by changing the total pipe cross-sectional area or pipe length or the total pipe cross-sectional area and pipe length.
【００１３】[0013]
【実施例】図１は本発明の一実施例を示す能動的消音装
置の構成図である。一次音源１の音波を伝搬するダクト
２の途中に、音を通過させ断熱効果を有する音透過断熱
体８を取り付け、この音透過断熱体８を介して二次音源
のスピーカ３と音量検出マイク５，６を設置する。これ
によって、スピーカ３と音量検出マイク５，６を熱から
保護しつつ、ダクト２に対してスピーカ及び音量検出マ
イクとしての機能を十分に発揮させようとしたものであ
る。なお、４は信号処理回路であり、この能動的消音装
置も、一次音源からの音の消音は従来例で説明したと同
様にしてなされる。図２は本発明の別の実施例を示す能
動的消音装置の構成図であって、一次音源１からの音量
検出を、回転パルス計７で行なわせたものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an active silencer showing an embodiment of the present invention. A sound transmissive heat insulator 8 that allows sound to pass therethrough and has a heat insulating effect is attached in the middle of a duct 2 that propagates the sound wave of the primary sound source 1, and a speaker 3 and a volume detection microphone 5 of a secondary sound source are attached via the sound transmissive heat insulator 8. , 6 are installed. Thus, the speaker 3 and the volume detecting microphones 5 and 6 are protected from heat, and at the same time, the duct 2 is made to sufficiently exhibit the functions of the speaker and the volume detecting microphone. Reference numeral 4 denotes a signal processing circuit, and this active muffling device also muffles the sound from the primary sound source in the same manner as described in the conventional example. FIG. 2 is a block diagram of an active muffler showing another embodiment of the present invention, in which the sound volume from the primary sound source 1 is detected by a rotary pulse meter 7.
【００１４】図３は図１の音透過断熱体８の一例を示す
ダクトの断面斜視図である。図において、２はダクト、
３はスピーカ、９はスピーカ３のケース、１０はダクト
の内側に設けた軽量の断熱材である。１１はパイプであ
って、ダクト２とケース９との間に複数平行に設け、各
パイプ１１の端をそれぞれダクト２とケース９に溶接又
はねじ等で固定する。複数のパイプ１１を図３のように
構成したパイプ構造物１２は、パイプ１１の内部を音が
通過し、パイプ１１の外部が外気にさらされてパイプ構
造物が冷却され、ダクト２とケース９との間で音透過断
熱体として作用する。FIG. 3 is a cross-sectional perspective view of a duct showing an example of the sound transmission heat insulating body 8 of FIG. In the figure, 2 is a duct,
3 is a speaker, 9 is a case of the speaker 3, and 10 is a lightweight heat insulating material provided inside the duct. Reference numeral 11 denotes a pipe, and a plurality of pipes 11 are provided in parallel between the duct 2 and the case 9, and the ends of each pipe 11 are fixed to the duct 2 and the case 9 by welding or screws. In the pipe structure 12 in which a plurality of pipes 11 are configured as shown in FIG. 3, sound passes through the inside of the pipe 11, the outside of the pipe 11 is exposed to the outside air, and the pipe structure is cooled. Acts as a sound-transmitting heat insulator between and.
【００１５】図４は図１の音透過断熱体８の別の例を示
すダクトの断面斜視図である。１３は周囲が囲われた箱
体であって、箱体１３には複数のパイプ１１を貫通させ
る。そして、パイプ１１の貫通方向と平行な箱体１３の
対向面を、それぞれダクト２とケース９に溶接又はねじ
等で固定する。複数のパイプ１１を図４のように構成し
たパイプ構造物１４は、パイプ１１の外部を音が通過
し、パイプ１１の内部が外気にさらされてパイプ構造物
が冷却され、ダクト２とケース９との間で音透過断熱体
として作用する。なお、図３、図４のパイプ構造物１
２，１４に用いるパイプは熱伝導率の大きいものがよ
く、銅パイプなどが好適である。FIG. 4 is a cross-sectional perspective view of a duct showing another example of the sound transmission heat insulating body 8 of FIG. Reference numeral 13 is a box whose circumference is enclosed, and a plurality of pipes 11 are passed through the box 13. Then, the opposing surfaces of the box body 13 parallel to the penetrating direction of the pipe 11 are fixed to the duct 2 and the case 9 by welding or screws. In the pipe structure 14 in which the plurality of pipes 11 are configured as shown in FIG. 4, sound passes through the outside of the pipe 11, the inside of the pipe 11 is exposed to the outside air, and the pipe structure is cooled. Acts as a sound-transmitting heat insulator between and. The pipe structure 1 shown in FIGS.
The pipes used for 2 and 14 are preferably those having a high thermal conductivity, and copper pipes and the like are preferable.
【００１６】図５は図３又は図４の構成において、ダク
ト２内を流れる気体温度及びパイプ構造物１２、１４の
各部寸法をある状態に設定して実験した、ダクト２側と
スピーカ３側の温度比較図である。これによれば、スピ
ーカ３側の温度を常温程度に維持できることがわかる。
なお、スピーカ３側の温度を常温程度に維持すること
は、パイプ構造物１２、１４の各部の寸法の組合わせに
よって、いろいろな場合に実現できる。FIG. 5 shows an experiment in which the temperature of the gas flowing in the duct 2 and the dimensions of the pipe structures 12 and 14 in the configuration of FIG. It is a temperature comparison figure. According to this, it is understood that the temperature of the speaker 3 side can be maintained at about room temperature.
Note that maintaining the temperature on the speaker 3 side at about room temperature can be realized in various cases by combining the dimensions of the respective parts of the pipe structures 12 and 14.
【００１７】図６はパイプ構造物１２のパイプの総断面
積の変化による、スピーカの音圧レベルの周波数特性で
ある。実線は総断面積が零すなわちパイプ構造体１２を
使用しない場合、一点鎖線は総断面積がＡの場合、破線
は総断面積が２Ａの場合である。この図より、パイプ構
造体１２がない場合は、スピーカの音圧レベルはほぼ一
定しているのに対し、パイプ構造体１２を設けた場合
は、特定の周波数にてスピーカの音圧レベルが増大する
ことがわかる。また、総断面積がＡから２Ａへ２倍にな
ると、スピーカの音圧レベルが増大する周波数はｆ0 か
ら２1/2 ・ｆ0 に変化する。FIG. 6 is a frequency characteristic of the sound pressure level of the speaker according to the change in the total cross-sectional area of the pipe of the pipe structure 12. The solid line shows the case where the total cross-sectional area is zero, that is, the pipe structure 12 is not used, the dashed-dotted line shows the case where the total cross-sectional area is A, and the broken line shows the case where the total cross-sectional area is 2A. From this figure, when the pipe structure 12 is not provided, the sound pressure level of the speaker is substantially constant, whereas when the pipe structure 12 is provided, the sound pressure level of the speaker increases at a specific frequency. I understand that When the total cross-sectional area doubles from A to 2A, the frequency at which the sound pressure level of the speaker increases changes from f 0 to 2 1/2 · f 0 .
【００１８】図７は図３、図４の構造がヘルムホルツの
共鳴器として作用する説明図である。（ａ）は図３の場
合、（ｂ）は図４の場合をそれぞれ示し、図中の符号は
図３、図４と同一物を示す。いずれの場合にも、パイプ
構造物１２，１４がオリフィスとして作用し、オリフィ
スの総断面積Ｓは、（ａ）の場合にはパイプ総断面積で
あって、パイプ断面積×パイプ本数となり、（ｂ）の場
合には、スピーカと接する面の箱体断面積−パイプ総断
面積となる。そして、ヘルムホルツの共鳴周波数ｆは次
式（１）で表され、これが前述した総断面積の変化に伴
って、スピーカの音圧レベルが増大した理由でもある。FIG. 7 is an explanatory diagram in which the structure of FIGS. 3 and 4 functions as a Helmholtz resonator. (A) shows the case of FIG. 3, (b) shows the case of FIG. 4, respectively, and the reference numerals in the figure indicate the same parts as those in FIGS. In either case, the pipe structures 12 and 14 act as orifices, and the total cross-sectional area S of the orifices is the pipe total cross-sectional area in the case of (a), which is pipe cross-sectional area x number of pipes, In the case of b), it becomes the box cross-sectional area of the surface in contact with the speaker-the total cross-sectional area of the pipe. The Helmholtz resonance frequency f is expressed by the following equation (1), which is also the reason why the sound pressure level of the speaker is increased in accordance with the change in the total cross-sectional area described above.
【００１９】[0019]
【数１】 [Equation 1]
【００２０】なお、パイプ構造物１２，１４のパイプ総
断面積の変更は、パイプにあらかじめバルブやオリフィ
スを備えておき、このバルブやオリフィスによって行う
ことができる。また、パイプ総断面積やパイプ長の変更
は、パイプ構造物１２，１４のダクト２やケース９への
固定をねじで行うようにしておき、パイプ構造物１２，
１４全体を取替える等によって可能である。その他、パ
イプ構造物１２，１４をブロック単位で製作しておい
て、ブロック単位毎に取替えることもできる。The total cross-sectional area of the pipes of the pipe structures 12 and 14 can be changed by previously providing the pipes with valves and orifices. Further, the total cross-sectional area of the pipe and the pipe length are changed by fixing the pipe structures 12 and 14 to the duct 2 and the case 9 with screws.
It is possible by replacing the whole 14 or the like. In addition, the pipe structures 12 and 14 may be manufactured in block units and replaced in block units.
【００２１】また、音透過断熱体は図３、図４のように
パイプを用いた構造としないで、図８のように、ケース
９のスピーカ３とダクト２間に穴１５を数個あけただけ
の構造にしてもよい。図８の音透過断熱体８の利用例を
図９により説明する。図９中、１はエンジンなどの一次
音源、１６は建屋、１７は煙穴である。煙穴効果により
ダクト内圧力が背圧に成っている箇所に、音透過断熱体
８を設置すれば、外気を吸い込み自然冷却が促進され
る。穴１５の径が小さく、数が少なければ、穴１５から
建屋１６内部への漏れ音はわずかであり、問題は生じな
い。As shown in FIG. 8, several holes 15 are provided between the speaker 3 and the duct 2 of the case 9 as shown in FIG. You may make it a structure only. An example of using the sound transmission heat insulating body 8 in FIG. 8 will be described with reference to FIG. In FIG. 9, 1 is a primary sound source such as an engine, 16 is a building, and 17 is a smoke hole. If the sound transmitting heat insulating body 8 is installed at a place where the pressure inside the duct is back pressure due to the smoke hole effect, the outside air is sucked in and natural cooling is promoted. If the diameter of the holes 15 is small and the number thereof is small, the leakage sound from the holes 15 to the inside of the building 16 is slight and no problem occurs.
【００２２】[0022]
【発明の効果】以上説明したように本発明によれば、高
温ガスが流れるダクトに対しても、二次音源と音量検出
センサをダクトの途中の任意の場所に設けることがで
き、その結果、次のような効果を有する能動的消音装置
が得られる。 （ａ）二次音源と音量検出センサを外部に面して設置す
る必要がなくなり、雨や風に対する特別な対策が不要と
なる。 （ｂ）二次音源をダクトの途中に設けることで、ダクト
内部で音の干渉が行われ、減音効果に指向性を生じな
い。 （ｃ）二次音源と音量検出センサを任意の場所に設置で
きるので、施工性、メンテナンス性が向上する。 （ｄ）音透過断熱体であるパイプ構造物は構造が簡単で
あり、また、パイプ総断面積やパイプ長を変更すること
で、二次音源の音圧レベルを特定周波数において増大さ
せることができる。 （ｅ）全体として装置コスト、メンテナンス費の低減が
図れる。As described above, according to the present invention, the secondary sound source and the volume detecting sensor can be provided at any place in the duct even for the duct through which the high temperature gas flows, and as a result, An active silencer having the following effects can be obtained. (A) It is not necessary to install the secondary sound source and the volume detection sensor facing the outside, and special measures against rain and wind are unnecessary. (B) By providing the secondary sound source in the middle of the duct, sound interference occurs inside the duct, and directivity does not occur in the noise reduction effect. (C) Since the secondary sound source and the volume detection sensor can be installed at any place, the workability and maintainability are improved. (D) The pipe structure, which is a sound-transmitting heat insulator, has a simple structure, and the sound pressure level of the secondary sound source can be increased at a specific frequency by changing the total pipe cross-sectional area and the pipe length. .. (E) As a whole, the device cost and maintenance cost can be reduced.
【図１】本発明の一実施例を示す能動的消音装置の構成
図である。FIG. 1 is a configuration diagram of an active silencer showing an embodiment of the present invention.
【図２】本発明の別の実施例を示す能動的消音装置の構
成図である。FIG. 2 is a configuration diagram of an active silencer showing another embodiment of the present invention.
【図３】音透過断熱体の一例を示すダクトの断面斜視図
である。FIG. 3 is a cross-sectional perspective view of a duct showing an example of a sound-transmitting heat insulating body.
【図４】音透過断熱体の別の例を示すダクトの断面斜視
図である。FIG. 4 is a sectional perspective view of a duct showing another example of the sound-transmitting heat insulating body.
【図５】図３の構成におけるダクト側とスピーカ側の温
度比較図である。5 is a temperature comparison diagram between the duct side and the speaker side in the configuration of FIG.
【図６】スピーカの音圧レベルの周波数特性である。FIG. 6 is a frequency characteristic of a sound pressure level of a speaker.
【図７】ヘルムホルツの共鳴器の説明図である。FIG. 7 is an explanatory diagram of a Helmholtz resonator.
【図８】音透過断熱体の別の例を示すダクトの断面斜視
図である。FIG. 8 is a cross-sectional perspective view of a duct showing another example of the sound-transmitting heat insulating body.
【図９】図８の音透過断熱体の利用説明図である。。FIG. 9 is an explanatory view of using the sound-transmitting heat insulating body of FIG. .
【図１０】従来の能動的消音装置の構成図である。FIG. 10 is a configuration diagram of a conventional active silencer.
１ 一次音源 ２ ダクト ３ スピーカ ４ 信号処理回路 ５，６ 音量検出マイク ８ 音透過断熱体 １１ パイプ １２，１４ パイプ構造物 1 Primary Sound Source 2 Duct 3 Speaker 4 Signal Processing Circuit 5, 6 Volume Detection Microphone 8 Sound Transmission Insulator 11 Pipe 12, 14 Pipe Structure
Claims (4)
波を伝搬するダクトと、音量を検出する音量検出センサ
と、一次音源から発せられる音波と逆位相で同振幅の音
波を放射する二次音源とを備えた能動的消音装置におい
て、 音を通過させ断熱効果を有する音透過断熱体をダクトに
設け、この音透過断熱体に前記二次音源と音量検出セン
サとを設置したことを特徴とする能動的消音装置。1. A primary sound source, a duct for propagating a sound wave emitted from the primary sound source, a volume detection sensor for detecting a sound volume, and a secondary sound source for radiating a sound wave of the same amplitude in a phase opposite to that of the sound wave emitted from the primary sound source. In the active muffling device including the above, a sound transmitting heat insulator having a heat insulating effect that allows sound to pass through is provided in the duct, and the secondary sound source and the volume detection sensor are installed in the sound transmitting heat insulator. Active silencer.
行にして一端を前記ダクトに固定したパイプ構造物と
し、ダクトと反対側のパイプ端部に二次音源と音量検出
センサを設置したことを特徴とする請求項１記載の能動
的消音装置。2. The sound-transmitting heat insulating body is a pipe structure in which a plurality of pipes are arranged in parallel and one end is fixed to the duct, and a secondary sound source and a volume detecting sensor are installed at a pipe end opposite to the duct. The active muffler according to claim 1, wherein
にこの箱体を貫通する複数のパイプを配したパイプ構造
物とし、このパイプ構造物のパイプと平行な箱体の一面
を前記ダクトに固定し、ダクトと反対側の箱体面に二次
音源と音量検出センサを設置したことを特徴とする請求
項１記載の能動的消音装置。3. The sound-transmitting heat insulating body is a pipe structure in which a plurality of pipes penetrating the box body are arranged in a box body surrounding the box body, and one surface of the box body parallel to the pipes of the pipe structure is provided. 2. The active muffler according to claim 1, wherein the active muffler is fixed to the duct, and a secondary sound source and a volume detection sensor are installed on the surface of the box opposite to the duct.
パイプ長又はパイプ総断面積及びパイプ長を変更可能と
したことを特徴とする請求項２又は請求項３記載の能動
的消音装置。4. The active silencer according to claim 2 or 3, wherein the total pipe cross-sectional area or pipe length of the pipe structure or the total pipe cross-sectional area and pipe length can be changed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4058284A JP2903841B2 (en) | 1992-03-16 | 1992-03-16 | Active silencer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4058284A JP2903841B2 (en) | 1992-03-16 | 1992-03-16 | Active silencer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05257483A true JPH05257483A (en) | 1993-10-08 |
| JP2903841B2 JP2903841B2 (en) | 1999-06-14 |
Family
ID=13079898
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4058284A Expired - Fee Related JP2903841B2 (en) | 1992-03-16 | 1992-03-16 | Active silencer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2903841B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0674097A1 (en) * | 1994-02-22 | 1995-09-27 | ELECTRONIC SOUND ATTENUATION S.p.A. | Active exhaust gas muffler |
| JP2017078403A (en) * | 2015-09-11 | 2017-04-27 | エーバーシュペッヒャー・エグゾースト・テクノロジー・ゲーエムベーハー・ウント・コンパニー・カーゲー | Connection pipe for connecting active silencer to exhaust system for combustion engine |
-
1992
- 1992-03-16 JP JP4058284A patent/JP2903841B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0674097A1 (en) * | 1994-02-22 | 1995-09-27 | ELECTRONIC SOUND ATTENUATION S.p.A. | Active exhaust gas muffler |
| JP2017078403A (en) * | 2015-09-11 | 2017-04-27 | エーバーシュペッヒャー・エグゾースト・テクノロジー・ゲーエムベーハー・ウント・コンパニー・カーゲー | Connection pipe for connecting active silencer to exhaust system for combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2903841B2 (en) | 1999-06-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |