JPS6248047B2 - - Google Patents
Info
- Publication number
- JPS6248047B2 JPS6248047B2 JP53124656A JP12465678A JPS6248047B2 JP S6248047 B2 JPS6248047 B2 JP S6248047B2 JP 53124656 A JP53124656 A JP 53124656A JP 12465678 A JP12465678 A JP 12465678A JP S6248047 B2 JPS6248047 B2 JP S6248047B2
- Authority
- JP
- Japan
- Prior art keywords
- introduction pipe
- frequency
- resonance
- sound
- movable valve
- 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.)
- Expired
Links
- 230000010349 pulsation Effects 0.000 claims description 7
- 230000003321 amplification Effects 0.000 description 9
- 238000003199 nucleic acid amplification method Methods 0.000 description 9
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 230000003584 silencer Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000011358 absorbing material Substances 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
Landscapes
- Exhaust Silencers (AREA)
- Pipe Accessories (AREA)
Description
【発明の詳細な説明】
本発明は、脈動源又は音源から出る音を消音器
に導くための導入管、特に自動車用エンジンに用
いられる導入管に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an introduction pipe for guiding sound emitted from a pulsation source or a sound source to a muffler, and particularly to an introduction pipe used in an automobile engine.
従来、この種の導入管は、固定された1本の管
により構成されているので、導入管内の状態によ
つては共鳴が起こり、これを避けるため、大型で
複雑な構成を有する消音器を必要としていた。特
に、自動車用エンジンに用いられる場合は、運転
状態が大きく変るため、ある回転数で共鳴しなく
とも、別の回転数で共鳴してしまい、これを消音
するために新たな消音構造を付加しなければなら
ず、消音器の構造を複雑にし、消音器の設計を困
難にしていた。 Conventionally, this type of introduction tube has been constructed from a single fixed tube, so resonance may occur depending on the conditions inside the introduction tube.To avoid this, a large and complicated silencer has been installed. I needed it. In particular, when used in automobile engines, the operating conditions change significantly, so even if it does not resonate at a certain rotation speed, it will resonate at a different rotation speed, so a new noise-reducing structure is added to muffle this noise. This complicates the structure of the silencer and makes the design of the silencer difficult.
そこで、本発明は、導入管の途中に電磁式の可
動弁により導入管との連通または遮断を制御され
る、境界構造を形成する室を設け、可動弁を適宜
開閉制御することにより、導入管内が常に共鳴状
態にならないように構成し、もつて前述の欠点を
解消した反共鳴導入管を提供することを目的とす
るものである。 Therefore, the present invention provides a chamber in the middle of the introduction pipe that forms a boundary structure whose communication or isolation with the introduction pipe is controlled by an electromagnetic movable valve, and controls the opening and closing of the movable valve as appropriate. It is an object of the present invention to provide an anti-resonance introduction tube which is constructed so that the resonance does not always occur, and which eliminates the above-mentioned drawbacks.
以下、図面に示す実施例に基づき、本発明を詳
細に説明する。 Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
導入管1は、第1図に示すように、エンジン等
の脈動源又は音源2と消音器3とを連結してい
る。導入管1の中央部には孔1aが穿設されてお
り、孔1aは吸音材で囲まれた、入口の他は密閉
された室5に連通している。 As shown in FIG. 1, the introduction pipe 1 connects a pulsation source or sound source 2, such as an engine, and a muffler 3. A hole 1a is bored in the center of the introduction pipe 1, and the hole 1a communicates with a chamber 5 surrounded by sound absorbing material and sealed except for the entrance.
この室5は境界構造を形成するもので、ここで
いう境界構造とは、音響的に境界をなす構造をい
う。また音響的に境界をなすとは、次のように説
明される。即ち、媒質中の音の進行方向に垂直な
ある平面上での平均音圧pと体積速度Uとの複素
数比を音響インピーダンスZといい、
Z〓=p〓/U〓
(「・」は、角周波数ωと位相角θとを含めた複素
数実効値であることを示す)で表わされるが、第
6図のようなA点を含む垂直平面の左右における
音圧と体積速度とをそれぞれp〓1、U〓1およびp〓
2、U〓2としたときそれぞれのインピーダンス
Z〓1=p〓1/U〓1、Z〓2=p〓2/U
〓2
がZ1≠Z2のとき、A点を含む垂直平面は音響的に
境界をなすという。 This chamber 5 forms a boundary structure, and the boundary structure here refers to a structure that forms an acoustic boundary. Also, forming an acoustic boundary is explained as follows. In other words, the complex ratio between the average sound pressure p and the volume velocity U on a plane perpendicular to the direction of sound propagation in the medium is called acoustic impedance Z, and Z〓=p〓/U〓 (“・” means It is expressed as a complex effective value including the angular frequency ω and the phase angle θ), but the sound pressure and volume velocity on the left and right sides of the vertical plane including the point A as shown in Fig. 6 are respectively expressed as p〓 1 , U〓 1 and p〓
2 , U〓 2 , the respective impedances Z〓 1 = p〓 1 /U〓 1 , Z〓 2 = p〓 2 /U
〓 When Z 1 ≠ Z 2 , the vertical plane containing point A is said to be acoustically bounded.
また、孔1aは可動弁6により開閉自在となつ
ており、可動弁6は第2図に示すように、電磁コ
イル7の励磁によりスプリング8に抗して開放作
動される。電磁コイル7は、エンジンの回転数等
により検出される周波数検出器10に基づき作動
する演算装置である演算スイツチ11の切換操作
により、電源12から通電され或いは通電を遮断
される。 The hole 1a can be opened and closed by a movable valve 6, and the movable valve 6 is opened against a spring 8 by the excitation of an electromagnetic coil 7, as shown in FIG. The electromagnetic coil 7 is energized or de-energized by a power source 12 by a switching operation of an arithmetic switch 11, which is an arithmetic device operated based on a frequency detector 10 detected by the engine rotational speed or the like.
ところで、本実施例による導入管1は一端閉
管、他端開管となつているので、可動弁6を閉塞
した状態では
fc=(2n−1)c/4l
なる周波数で管系共鳴を起こす。なお、ここでn
は1、2、3等の自然数、cは音速、lは導入管
1の長さである。これを図示すれば、第3図に破
線aで示すようになる。即ち、この管系では、n
=1、2、3、………等のときの上式により算出
される周波数c/4l、3c/4l、5c/4l、……
…(これらをfaで
示す)に対して共鳴するので、周波数と音の増幅
量との関係は、第3図の波線aのようになる。ま
た、可動弁2を開放し、孔1aにより導入管1の
中央に室5を通じさせ、導入管1の中央に境界構
造を設けると、境界自身の効果を無視すれば、第
3図に一点鎖線bで示すように、その共鳴周波数
は、破線aの共鳴周波数faとは位相がずれた位置
に表われる。この場合は、一端閉管、他端開管の
挿入管(導入管1の左半部)と、両端開管の挿入
管(導入管1の右半部)の二つの挿入管とは等価
になる。 By the way, since the introduction pipe 1 according to this embodiment has one end closed and the other end open, when the movable valve 6 is closed, the pipe system resonates at a frequency of f c =(2n-1)c/4l. . Note that here n
is a natural number such as 1, 2, or 3, c is the speed of sound, and l is the length of the introduction pipe 1. This is illustrated by the broken line a in FIG. 3. That is, in this tube system, n
Frequencies c/4l, 3c/4l, 5c/4l, . . . calculated by the above formula when = 1, 2, 3, . . .
... (these are indicated by fa), so the relationship between the frequency and the amount of sound amplification is as shown by the dotted line a in Fig. 3. Furthermore, if the movable valve 2 is opened and the chamber 5 is made to communicate with the center of the introduction pipe 1 through the hole 1a, and a boundary structure is provided at the center of the introduction pipe 1, then if the effect of the boundary itself is ignored, As shown by b, the resonant frequency appears at a position out of phase with the resonant frequency fa indicated by the broken line a. In this case, the two insertion tubes are equivalent: the insertion tube with one end closed and the other end open (the left half of introduction tube 1), and the insertion tube with both ends open (the right half of introduction tube 1). .
一端閉管の部分については、元の管の長さlを
1/2にしたものに等しいから、前式より算出され
る共鳴周波数は、n=1、2、………に対して
2c/4l、6c/4l、10c/4l、………となる
。 For the part with one end closed, the length l of the original pipe is
Since it is equal to 1/2, the resonant frequencies calculated from the above equation are 2c/4l, 6c/4l, 10c/4l, . . . for n=1, 2, .
また、両端開管の場合の共鳴周波数fcを表わ
す式(Lは管の長さ、n、cは前式を同じ)
fc=nc/2L
においてL=l/2とし、n=1、2、………とすれ
ば両端開管の部分における共鳴周波数は、4c/4l、
8c/4l、………となる。 Also, the formula expressing the resonant frequency f c in the case of a pipe with both ends open (L is the length of the pipe, n and c are the same as the previous formula) fc = nc/2L, where L = l/2, n = 1, 2 , . . . , the resonant frequencies at the portion where both ends are open are 4c/4l, 8c/4l, .
そこで両部分全体として、周波数が2c/4l、4c
/4l、
6c/4l、8c/4l、………(これらをfbとする)
の場合に共
鳴を起し、周波数と音の増幅量との関係は第3図
の一点鎖線bのようになる。 Therefore, the frequencies of both parts as a whole are 2c/4l, 4c
/4l, 6c/4l, 8c/4l, ...... (these are fb)
In the case of , resonance occurs, and the relationship between the frequency and the amount of sound amplification is as shown by the dashed-dotted line b in FIG.
そこで管1に導入される音の周波数を、エンジ
ンの回転数計測等の手段を利用した周波数検出器
10で検出し、周波数がfaの何れかである場合
は、演算スイツチ11を閉じて電磁コイル7を励
磁し、可動弁6を開く。これにより導入管1の周
波数に対する共鳴状態は第3図の一点鎖線bの状
態となり、周波数faに対しては共鳴せず、周波数
の変化に対して増幅量は一点鎖線bの裾の部分d
に沿つて変化する。 Therefore, the frequency of the sound introduced into the pipe 1 is detected by a frequency detector 10 using means such as engine rotation speed measurement, and if the frequency is fa, the calculation switch 11 is closed and the electromagnetic coil is 7 is energized and the movable valve 6 is opened. As a result, the resonant state of the introduction tube 1 with respect to the frequency becomes the state shown by the dashed-dotted line b in FIG.
changes along.
周波数fbの音が導入された場合は、周波数検出
器10によりこれを検知して可動弁6を閉じる
と、導入管1の共鳴状態は波線aの状態となるか
ら、増幅量は第3図の破線aの裾の部分eに沿つ
て変化するようになる。 When a sound with frequency fb is introduced, when it is detected by the frequency detector 10 and the movable valve 6 is closed, the resonance state of the introduction pipe 1 becomes the state shown by the broken line a, so the amount of amplification is as shown in Fig. 3. It begins to change along the bottom part e of the broken line a.
このようにして導入される音の周波数に対応し
て可動弁6を開閉すれば、導入管1が著しく共鳴
することを避けて、各線a,bの裾の部分d,e
に沿い増幅量を小さくして音を通過させることが
できる。 By opening and closing the movable valve 6 in accordance with the frequency of the sound introduced in this way, the introduction tube 1 can be prevented from resonating significantly, and the bottom portions d and e of each line a and b can be
It is possible to reduce the amount of amplification along the lines and allow the sound to pass through.
次に第4図に示した、両端が開管になつている
か、もしくは両端が開管状態にある境界15にな
つており、長さlの導入管1′の後端からl/3の位
置に境界構造を設けた例について説明する。この
場合は、可動弁6を閉じると導入管1′の共鳴状
態は第5図の破線a′の状態となり、可動弁6を開
くと共鳴状態は一点鎖線b′の状態となる。そこで
音の周波数を周波数検出器10で検出して可動弁
6を開閉すれば、第3図の場合と同様に破線a′、
一点鎖線b′の裾の部分d′,e′に沿い増幅量を少な
くして音を通過させることができる。但し、この
例の場合は、孔1a′が導入管1′の中央にないた
め、管1′の2/3lの長さの前部と1/3lの長さの
後部との共鳴位置の重なる周波数があるので、一
点鎖線b′の3c/2l、3c/l、………の位置に増
幅量のピー
ク値の高い所ができる。この位置は破線a′のピー
ク位置と重なるから、可動弁6を操作しても増幅
値を破線a′のピーク値よりも小さくはできない。
従つてこの場合は他の手段によりこの周波数の音
を減衰させるように考慮する必要がある。この場
合も、孔1a′による境界構造を導入管1′の後端
からl/6の位置に設ければ、3c/2lの周波数での共
鳴
を阻止することができる。 Next, as shown in Fig. 4, both ends are open, or there is a boundary 15 where both ends are open, and the position is l/3 from the rear end of the introducing tube 1' having a length l. An example in which a boundary structure is provided will be explained. In this case, when the movable valve 6 is closed, the resonance state of the introduction pipe 1' becomes the state indicated by the broken line a' in FIG. 5, and when the movable valve 6 is opened, the resonance state becomes the state indicated by the dashed-dotted line b'. Therefore, if the frequency of the sound is detected by the frequency detector 10 and the movable valve 6 is opened and closed, the broken line a' and
Along the bottom portions d' and e' of the dashed-dotted line b', the amount of amplification can be reduced to allow the sound to pass. However, in this example, since the hole 1a' is not in the center of the introduction pipe 1', the resonance positions of the 2/3l length front part and the 1/3l length rear part of the pipe 1' overlap. Since there are frequencies, there are high peak values of the amplification amount at positions 3c/2l, 3c/l, . . . of the dashed-dotted line b'. Since this position overlaps with the peak position of the broken line a', the amplification value cannot be made smaller than the peak value of the broken line a' even if the movable valve 6 is operated.
Therefore, in this case, consideration must be given to attenuating the sound of this frequency by other means. In this case as well, resonance at the frequency of 3c/2l can be prevented by providing the boundary structure of the hole 1a' at a position 1/6 from the rear end of the introduction tube 1'.
以上説明したように、本発明は、導入管の途中
に可動弁6により導入管との連通および遮断を制
御される密閉された室5を設け、この室5の形成
する境界構造を利用して導入管内が共鳴状態にな
らないように室5と導入管とを連通させまたは遮
断するものであるから、導入管内の共鳴増幅を避
けることができ、消音器3は脈動源又は音源2の
みの消音を考慮すれば良く、消音器設計が大変容
易になる。特に、自動車用エンジンに用いれば、
周波数変化の範囲が広いにもかかわらず、常に共
鳴増幅を避けることができ、従来のように大型で
複雑な消音器を必要とせず、単純で安価な消音器
で、一層の消音効果をあげることができる。 As explained above, the present invention provides a sealed chamber 5 in the middle of an introduction pipe whose communication and isolation with the introduction pipe is controlled by a movable valve 6, and utilizes the boundary structure formed by this chamber 5. Since the chamber 5 and the introduction pipe are communicated with each other or cut off so that the inside of the introduction pipe does not become in a resonance state, resonance amplification within the introduction pipe can be avoided, and the muffler 3 is designed to silence only the pulsation source or the sound source 2. All you have to do is take this into account, and the design of the muffler becomes very easy. Especially when used in automobile engines,
To always avoid resonance amplification despite a wide range of frequency changes, and to achieve further noise reduction effects with a simple and inexpensive muffler without the need for a large and complicated muffler as in the past. Can be done.
第1図は本発明による導入管を示す側断面図、
第2図はその可動弁を示す断面図、第3図は第1
図に示す導入管による周波数特性図、第4図は他
の実施例を示す導入管の側断面図、第5図はその
周波数特性図、第6図は音響的境界の説明図であ
る。
1,1′:導入管、1a,1a′:孔、2:脈動
源又は音源、3:消音器、5:室、6:可動弁、
7:電磁コイル、8:スプリング、10:周波数
検出器、11:演算装置、12:電源、15:境
界。
FIG. 1 is a side sectional view showing an introduction tube according to the present invention;
Fig. 2 is a sectional view showing the movable valve, and Fig. 3 is a sectional view showing the movable valve.
FIG. 4 is a side sectional view of the introduction tube showing another embodiment, FIG. 5 is a frequency characteristic diagram thereof, and FIG. 6 is an explanatory diagram of acoustic boundaries. 1, 1': introduction pipe, 1a, 1a': hole, 2: pulsation source or sound source, 3: muffler, 5: chamber, 6: movable valve,
7: Electromagnetic coil, 8: Spring, 10: Frequency detector, 11: Arithmetic device, 12: Power supply, 15: Boundary.
Claims (1)
入管において、この導入管の途中に、電磁式の可
動弁6を介して密閉および導入管内との連通自在
で、導入管に対して境界構造を形成する室5を設
け、前記脈動源又は音源の周波数を検出する周波
数検出器10、および導入管1内を共鳴状態にす
る音波が到来したときにこの周波数検出器10の
出力に基いて可動弁6を共鳴状態を阻止する方向
に駆動する演算装置を付設した反共鳴導入管。 2 前記脈動源又は音源が自動車用エンジンであ
り、かつ前記周波数の検出をエンジン回転数によ
り行なう前記特許請求の範囲第1項記載の反共鳴
導入管。[Scope of Claims] 1. In an introduction pipe that guides sound emitted from a pulsation source or a sound source to a muffler, an introduction pipe is provided in the middle of the introduction pipe, which can be sealed and freely communicated with the inside of the introduction pipe via an electromagnetic movable valve 6. A frequency detector 10 is provided with a chamber 5 forming a boundary structure for the tube, and detects the frequency of the pulsation source or sound source, and this frequency detector 10 detects the arrival of a sound wave that brings the interior of the introduction tube 1 into a resonant state. An anti-resonance introduction pipe equipped with a calculation device that drives the movable valve 6 in a direction to prevent a resonance state based on the output of the anti-resonance introduction pipe. 2. The anti-resonance introduction tube according to claim 1, wherein the pulsation source or sound source is an automobile engine, and the frequency is detected based on the engine rotation speed.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12465678A JPS5551909A (en) | 1978-10-12 | 1978-10-12 | Antiresonance inducing pipe |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12465678A JPS5551909A (en) | 1978-10-12 | 1978-10-12 | Antiresonance inducing pipe |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5551909A JPS5551909A (en) | 1980-04-16 |
JPS6248047B2 true JPS6248047B2 (en) | 1987-10-12 |
Family
ID=14890793
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP12465678A Granted JPS5551909A (en) | 1978-10-12 | 1978-10-12 | Antiresonance inducing pipe |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5551909A (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4389982A (en) * | 1981-10-20 | 1983-06-28 | Performance Industries, Inc. | Internal combustion engine fuel supply system |
US4539947A (en) * | 1982-12-09 | 1985-09-10 | Nippondenso Co., Ltd. | Resonator for internal combustion engines |
US4546733A (en) * | 1983-03-22 | 1985-10-15 | Nippondenso Co., Ltd. | Resonator for internal combustion engines |
JPH0819885B2 (en) * | 1988-12-28 | 1996-03-04 | マツダ株式会社 | Engine intake system |
CN111828129B (en) * | 2019-04-15 | 2021-09-14 | 广州汽车集团股份有限公司 | Exhaust noise adjusting device and method, exhaust noise adjusting system and vehicle |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5181225A (en) * | 1975-01-09 | 1976-07-16 | Nippon Soken | Nainenkikanno haikimyakudoseigyokiko |
-
1978
- 1978-10-12 JP JP12465678A patent/JPS5551909A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5181225A (en) * | 1975-01-09 | 1976-07-16 | Nippon Soken | Nainenkikanno haikimyakudoseigyokiko |
Also Published As
Publication number | Publication date |
---|---|
JPS5551909A (en) | 1980-04-16 |
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