JPS6235008A - Temperature control type adaptive noise suppressor - Google Patents
Temperature control type adaptive noise suppressorInfo
- Publication number
- JPS6235008A JPS6235008A JP60175196A JP17519685A JPS6235008A JP S6235008 A JPS6235008 A JP S6235008A JP 60175196 A JP60175196 A JP 60175196A JP 17519685 A JP17519685 A JP 17519685A JP S6235008 A JPS6235008 A JP S6235008A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- resonator
- resonance
- sound source
- temperature
- 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
- F01N1/02—Silencing apparatus characterised by method of silencing by using resonance
-
- 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
- F01N2490/00—Structure, disposition or shape of gas-chambers
- F01N2490/14—Dead or resonance chambers connected to gas flow tube by relatively short side-tubes
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Silencers (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、内燃機関の排気音や、送風機、換気扇など回
転機器から生じるダクト内の周期音を大幅に消音させろ
装置に係る。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for significantly silencing the exhaust noise of an internal combustion engine and the periodic noise in a duct generated from rotating equipment such as a blower or a ventilation fan.
従来技術及びその問題点
共鳴型の消音器は、形状を大きくすることなしに、低周
波数の音を減衰させるのに効果があるため、単独である
いは空洞型消音器と組合わせて用いられている。その減
衰量は、共鳴周波数frただし、C:音速
S:共鳴管の断面積
l:共鳴管の長さ
V:共鳴室の容積
において、理論的には無限大となり、実際的にも極めて
大きくできる。したがって、音源の卓越周波数に共鳴器
の共鳴周波数を設定しておけば、消音効果は極めて大き
い。しかし、この共鳴型消音器は、共鳴周波数以外の周
波数の音をほとんど減衰させろことができない欠点をも
つ。そのため、回転数が常に変動する内燃機関などに共
鳴型消音器を適用した場合、そのままでは消音効果は発
揮できない。したがって、共鳴型消音器の共鳴管の数を
増したり、形状を変える(特公昭59−5764)など
して、共鳴周波数以外でもある程度減衰させろ発明があ
る。しかし、これば、共鳴周波数における極めて大きな
減衰効果を犠牲にしているため、純粋な共鳴器はどの消
音効果は期待できない欠点をもつ。また、共鳴室の容積
を変えて、共鳴周波数を音源の卓越周波数に適応的に追
従させる方法(特開昭59−250969)もある。し
かし、このように機械的に容積等を変えることは、機構
が複雑になるだけでなく、保守管理が困難になる欠点が
ある。Prior art and its problems Resonance-type silencers are effective in attenuating low-frequency sounds without increasing their size, so they are used alone or in combination with cavity-type silencers. . The amount of attenuation is determined by the resonance frequency fr, where C: speed of sound S: cross-sectional area of the resonance tube l: length of the resonance tube V: volume of the resonance chamber, theoretically it is infinite, and it can be made extremely large in practice. . Therefore, if the resonant frequency of the resonator is set to the predominant frequency of the sound source, the silencing effect is extremely large. However, this resonant muffler has the disadvantage that it cannot attenuate almost any sound at frequencies other than the resonant frequency. Therefore, when a resonant silencer is applied to an internal combustion engine or the like where the rotational speed constantly fluctuates, the noise reduction effect cannot be achieved as is. Therefore, there has been an invention to attenuate frequencies other than the resonance frequency to some extent by increasing the number of resonance tubes in a resonance type muffler or changing their shape (Japanese Patent Publication No. 59-5764). However, this comes at the expense of a very large damping effect at the resonant frequency, so a pure resonator has the disadvantage that no sound damping effect can be expected. There is also a method (Japanese Patent Laid-Open No. 59-250969) in which the volume of the resonance chamber is changed to adaptively make the resonance frequency follow the dominant frequency of the sound source. However, mechanically changing the volume, etc. in this way not only complicates the mechanism, but also has the drawback of making maintenance management difficult.
発明の目的
本発明は、かかる欠点を解決すべく、共鳴器部の温度を
加減することにより共鳴器の共鳴周波数を音源の卓越周
波数に応じて適応的に追従させ、回転数が常に変化する
自動車エンジンの排気音や、換気扇などを通して出てく
る工場騒音を大幅に減衰させるのに利用せんとするもの
である。OBJECTS OF THE INVENTION In order to solve these drawbacks, the present invention provides an automobile whose rotational speed constantly changes, in which the resonant frequency of the resonator adaptively follows the dominant frequency of the sound source by adjusting the temperature of the resonator section. It is intended to be used to significantly attenuate engine exhaust noise and factory noise coming out through ventilation fans.
発明の構成
本発明は、ダクト内の音を消すための共鳴型消音器にお
いて、音源となる回転機器の回転数を測定する回転計部
、あるいはダクト内の音源側の音波を周波数分析して、
その中で卓越した成分の周波数を検出する検出部と、上
記回転数や卓越周波数を共鳴器の共鳴周波数に比例させ
る変換部と、共鳴器の温度を加減して共鳴周波数を調整
させることのできる温度調節部とからなり、共鳴器の共
鳴周波数を回転数や卓越周波数に追従させろ構成となっ
ている。Structure of the Invention The present invention provides a resonant silencer for muffling sounds in a duct, which includes a tachometer unit that measures the rotational speed of a rotating device serving as a sound source, or a frequency analysis of a sound wave from the sound source side in the duct.
A detection section that detects the frequency of a prominent component among them, a conversion section that makes the rotation speed and predominant frequency proportional to the resonant frequency of the resonator, and a resonant frequency that can be adjusted by adjusting the temperature of the resonator. It consists of a temperature control section and is configured to make the resonance frequency of the resonator follow the rotational speed and dominant frequency.
発明の作用
図を用いて本発明の作用をさらに詳しく説明する。第1
図は、本発明の原理図である。この第1図において、4
は自動車のエンジン、送風機、換気扇など回転にともな
って生じる騒音源であり、それによって生じる音がダク
ト1に放出されていることを示す。ダクトには長さ11
断面積Sの共鳴管2、容積Vの共鳴室3からなるヘルム
ホルツ共鳴器が取りつけである。一般に、回転機器から
生じる音は、回転に同期した周期波形である。フーリエ
変換すればわかるように、周期波形(、t、基本周波数
とその整数倍の周波数成分をもっている。The operation of the present invention will be explained in more detail using the operation diagram of the invention. 1st
The figure is a diagram of the principle of the present invention. In this Figure 1, 4
is a noise source generated by the rotation of an automobile engine, blower, ventilation fan, etc., and indicates that the sound generated by this is emitted into the duct 1. The length of the duct is 11
A Helmholtz resonator consisting of a resonance tube 2 with a cross-sectional area S and a resonance chamber 3 with a volume V is attached. Generally, sound generated from rotating equipment has a periodic waveform that is synchronized with rotation. As can be seen by Fourier transformation, the periodic waveform (,t) has a fundamental frequency and frequency components that are integral multiples of the fundamental frequency.
すなわち、第2図のような周波数特性となる。その中で
卓越している周波数foは、回転機器の回転数をn、比
例定数をkとすれば、
fo=kn ・・(2)となる。That is, the frequency characteristics are as shown in FIG. 2. The predominant frequency fo among them is fo=kn (2), where n is the rotational speed of the rotating equipment and k is the proportionality constant.
一方、共鳴室内の温度をt℃とすれば、速度Cはc =
(332+0.6t ) tn / sとなる。した
がって、(1)式の共鳴周波数は、比例定数をhとすれ
ば、次式で表される。On the other hand, if the temperature inside the resonance chamber is t°C, the velocity C is c =
(332+0.6t) tn/s. Therefore, the resonance frequency in equation (1) is expressed by the following equation, where h is the proportionality constant.
fr = h (332+0.6t ) −(3
)(2)式の foと(3)式の f「を一致させるに
は、
t−1,67((k / h ) n−332)
−(4)とすればよい。すなわち、変換器6は、
回転計5で測定された回転数nを(4)式によってLに
変換させる。温度調節部7は、共鳴室の周囲に設けられ
たヒータを加熱して、共鳴室の温度をt℃に保持する。fr = h (332+0.6t) −(3
) To match fo in equation (2) and f in equation (3), use t-1,67((k/h) n-332)
−(4) may be used. That is, the converter 6 is
The rotational speed n measured by the tachometer 5 is converted to L using equation (4). The temperature controller 7 heats a heater provided around the resonance chamber to maintain the temperature of the resonance chamber at t°C.
このようにすれば、
fo = fr ・ (5)と
なり、共鳴器の共鳴周波数を消音すべき卓越周波数に一
致させることができる。共鳴器は共鳴周波数成分に対し
て大きく消音することができるので、ダクトの出口部で
は、回転器からの騒音が大幅に低下する。また、回転機
器の回転数が変化しても、第1図のように構成すれば、
共鳴周波数が音源の卓越周波数に常に一致する様になる
為、共鳴器の消音能力を最大限に利用することができる
。In this way, fo = fr · (5), and the resonant frequency of the resonator can be matched with the dominant frequency to be muted. Since the resonator can significantly damp the resonant frequency components, the noise from the rotor is significantly reduced at the outlet of the duct. Also, even if the rotation speed of the rotating equipment changes, if it is configured as shown in Figure 1,
Since the resonant frequency always matches the predominant frequency of the sound source, the silencing ability of the resonator can be utilized to the fullest.
実施例
回転数が測れない場合や、非回転機器による音源の場合
には、第3図のようにダクト内の音源寄りの1点からマ
イクロホン9で音源4′の騒音を検出して、10で周波
数分析をし、卓越周波数fr蚕検出して、変換器6、温
度調節部7を通して、fo=frとなるように温度調節
をなし、共鳴器の共鳴周波数を卓越周波数に追従させれ
ばよい。Example If the rotation speed cannot be measured or if the sound source is a non-rotating device, detect the noise from the sound source 4' with the microphone 9 from a point near the sound source in the duct as shown in Figure 3. Frequency analysis is performed to detect the dominant frequency fr, and the temperature is adjusted through the converter 6 and the temperature controller 7 so that fo=fr, and the resonant frequency of the resonator is made to follow the dominant frequency.
さらに、卓越周波数fO以外の成分2 fo、3toも
消音したい場合には、いままでのべたような共鳴器をダ
クト内に複数個設置すればよい。Furthermore, if it is desired to mute the components 2fo and 3to other than the dominant frequency fO, a plurality of resonators as described above may be installed in the duct.
発明の効果
以上性べて来た如く本発明によれば共鳴型消音器の高い
消音能力を常に発揮できるように共鳴周波数を適応的に
調節しているので、卓越層′e数が絶えず変動する騒音
においても、消音力か極めて強い効果がある。また、共
鳴周波数を変えるために、機械的可@機構を用いていな
いので、機構や保守が容易であり、音がもれ出る欠点も
ない。さらに、一つの共鳴器であらゆる周波数に適応で
きるので、共鳴周波数の異なる多くの共鳴器を用いろ必
要がない。したがって、装置を小型化することができる
効果もある。As described above, according to the present invention, the resonant frequency is adaptively adjusted so that the high silencing ability of the resonant silencer can always be exhibited, so that the number of dominant layers'e constantly fluctuates. It also has an extremely strong silencing effect when it comes to noise. Furthermore, since no mechanical mechanism is used to change the resonance frequency, the mechanism and maintenance are easy, and there is no problem of sound leakage. Furthermore, since one resonator can accommodate all frequencies, there is no need to use many resonators with different resonance frequencies. Therefore, there is an effect that the device can be made smaller.
第1図は本発明の原理図を示す。第2図は、卓越周波数
fOをもつ周期性騒音の周波数特性の例である。第3図
は、本発明の別の実施例を示す。
図中において、1はダクト、2は共鳴管、3は共鳴室、
4は回転を伴なう音源、4′は一般的な音源、5は回転
計、6は変換部、7は温度調節部、8はヒータ、9はマ
イクロホン、10は卓越周波数検出部である。
第10FIG. 1 shows a diagram of the principle of the present invention. FIG. 2 is an example of frequency characteristics of periodic noise having a dominant frequency fO. FIG. 3 shows another embodiment of the invention. In the figure, 1 is a duct, 2 is a resonance tube, 3 is a resonance chamber,
4 is a sound source accompanied by rotation, 4' is a general sound source, 5 is a tachometer, 6 is a conversion section, 7 is a temperature adjustment section, 8 is a heater, 9 is a microphone, and 10 is a dominant frequency detection section. 10th
Claims (1)
となる回転機器の回転数を測定する回転計部、あるいは
音源の卓越周波数を検出する検出部と、上記回転数や卓
越周波数を共鳴器の共鳴周波数に比例させる変換部と、
共鳴周波数を変えるために共鳴器を加熱冷却できる温度
調節部とからなり、共鳴器の共鳴周波数を回転数や卓越
周波数に追従させることを特徴とした温度制御式適応消
音装置。A resonant silencer for eliminating sound in a duct includes a tachometer unit that measures the rotation speed of a rotating device that is a sound source, or a detection unit that detects the predominant frequency of the sound source, and a resonator that detects the rotation speed or predominant frequency. a conversion unit that makes the resonance frequency proportional to the resonance frequency of the
A temperature-controlled adaptive silencer is characterized by comprising a temperature control section that can heat and cool a resonator in order to change the resonance frequency, and making the resonance frequency of the resonator follow the rotational speed and dominant frequency.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60175196A JPS6235008A (en) | 1985-08-08 | 1985-08-08 | Temperature control type adaptive noise suppressor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60175196A JPS6235008A (en) | 1985-08-08 | 1985-08-08 | Temperature control type adaptive noise suppressor |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6235008A true JPS6235008A (en) | 1987-02-16 |
JPH0260844B2 JPH0260844B2 (en) | 1990-12-18 |
Family
ID=15991972
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP60175196A Granted JPS6235008A (en) | 1985-08-08 | 1985-08-08 | Temperature control type adaptive noise suppressor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6235008A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02285686A (en) * | 1989-04-27 | 1990-11-22 | Matsushita Electric Ind Co Ltd | Gas laser |
FR2696268A1 (en) * | 1992-08-26 | 1994-04-01 | Daimler Benz Ag | Resonant cavity. |
JP2001265355A (en) * | 2000-01-24 | 2001-09-28 | Eads Deutschland Gmbh | Sound absorbing device and sound absorbing method |
-
1985
- 1985-08-08 JP JP60175196A patent/JPS6235008A/en active Granted
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02285686A (en) * | 1989-04-27 | 1990-11-22 | Matsushita Electric Ind Co Ltd | Gas laser |
FR2696268A1 (en) * | 1992-08-26 | 1994-04-01 | Daimler Benz Ag | Resonant cavity. |
JP2001265355A (en) * | 2000-01-24 | 2001-09-28 | Eads Deutschland Gmbh | Sound absorbing device and sound absorbing method |
EP1120774A3 (en) * | 2000-01-24 | 2004-11-03 | EADS Deutschland Gmbh | Acoustic absorber and method for sound absorption |
Also Published As
Publication number | Publication date |
---|---|
JPH0260844B2 (en) | 1990-12-18 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EXPY | Cancellation because of completion of term |