JPH0437219Y2 - - Google Patents
Info
- Publication number
- JPH0437219Y2 JPH0437219Y2 JP1986060747U JP6074786U JPH0437219Y2 JP H0437219 Y2 JPH0437219 Y2 JP H0437219Y2 JP 1986060747 U JP1986060747 U JP 1986060747U JP 6074786 U JP6074786 U JP 6074786U JP H0437219 Y2 JPH0437219 Y2 JP H0437219Y2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust
- exhaust pipe
- gas flow
- sound
- diameter
- 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
- 230000003584 silencer Effects 0.000 claims description 22
- 238000011144 upstream manufacturing Methods 0.000 claims description 21
- 239000011358 absorbing material Substances 0.000 claims description 17
- 238000010521 absorption reaction Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 230000007423 decrease Effects 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Exhaust Silencers (AREA)
Description
【考案の詳細な説明】
（産業上の利用分野）
本考案は、排気サイレンサ構造の改良に関する
ものである。[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in the structure of an exhaust silencer.
（従来技術）
エンジンから排出される排気ガスは消音器（サ
イレンサ）を通過させ、消音を行つてから大気中
に放出させている。(Prior Art) Exhaust gas discharged from an engine is passed through a silencer to muffle the noise before being released into the atmosphere.
このような消音器の構造としては特に高周波成
分を吸音により低減する吸音型構造のものが知ら
れている。第４図に示すように多孔１ａを有する
多孔排気管１の外周に吸音材により構成された吸
音層２を配しケーシング３で覆い、前記多孔排気
管１を矢印Ａ方向に通過する排気ガスの消音を行
う構造のものがある（実開昭59−165520号公報）。
しかしこのような排気サイレンサ構造は、2kc以
上の周波数の高周波の低減には効果が大きいが、
多孔排気管の内部を流れるガス流速が速くなるに
つれ、多孔排気管１に負圧が発生し多孔排気管１
の外周の吸音材２が多孔１ａより排気管１に吸引
され排気ガス流とともに外部へ排出されることが
ある。このため使用期間の増加に伴い、吸音材の
量が減少ししたがつて吸音層の吸音効果が低下す
ることがある。 As a structure of such a silencer, a sound absorbing structure that reduces high frequency components by sound absorption is particularly known. As shown in FIG. 4, a sound-absorbing layer 2 made of a sound-absorbing material is arranged around the outer periphery of a porous exhaust pipe 1 having porous holes 1a and covered with a casing 3, so that the exhaust gas passing through the porous exhaust pipe 1 in the direction of arrow A is There is one that has a structure that muffles noise (Japanese Utility Model Publication No. 165520/1983).
However, although this type of exhaust silencer structure is highly effective in reducing high frequencies of 2kc or higher,
As the gas flow rate inside the porous exhaust pipe increases, negative pressure is generated in the porous exhaust pipe 1.
The sound absorbing material 2 on the outer periphery of the exhaust pipe 1 may be sucked into the exhaust pipe 1 through the holes 1a and discharged to the outside together with the exhaust gas flow. Therefore, as the period of use increases, the amount of sound-absorbing material decreases, and the sound-absorbing effect of the sound-absorbing layer may decrease.
また、実開昭60−90510号公報に示すサイレン
サ４は、第５図のように、内部に吸音材２が配設
された外筒５の半径を排気管の軸線に沿つて連続
的に変化させることにより、外筒５の空間の半径
方向の寸法を連続的に変化させて、吸音材２の配
設状態の経時劣化を防止する構造を有する。 In addition, the silencer 4 shown in Japanese Utility Model Application Publication No. 60-90510 has the radius of the outer cylinder 5 in which the sound absorbing material 2 is disposed inside continuously changing along the axis of the exhaust pipe, as shown in Fig. 5. By doing so, it has a structure in which the radial dimension of the space of the outer cylinder 5 is continuously changed to prevent the arrangement state of the sound absorbing material 2 from deteriorating over time.
しかし、このような構造においても前述した例
と同様に、吸音材２が排気管１の孔部１ａから吸
引され矢印Ａ方向に吹き抜けて外部へ排出される
ことから生ずる吸音効果の低下は防止できない。 However, even in such a structure, as in the above-mentioned example, it is impossible to prevent the sound-absorbing effect from decreasing due to the sound-absorbing material 2 being sucked through the hole 1a of the exhaust pipe 1, blowing through in the direction of arrow A, and being discharged to the outside. .
このような吸音材２の飛散を防止するために、
吸音材間の繊維の中に接着剤等を入れ繊維間の結
びつきを強くして、飛散を防止する方法が考えら
れるがこれは、繊維間の結びつきが強くなること
から吸音材が硬化してしまうため吸音性能が低下
する。 In order to prevent such scattering of the sound absorbing material 2,
One possible method is to put adhesive etc. into the fibers between the sound-absorbing materials to strengthen the bonds between the fibers and prevent scattering, but this strengthens the bonds between the fibers and causes the sound-absorbing material to harden. Therefore, the sound absorption performance decreases.
したがつて確実な消音性能を保持しうる排気サ
イレンサ構造の開発が要望されている。 Therefore, there is a need for the development of an exhaust silencer structure that can maintain reliable noise reduction performance.
（考案の目的）
本考案は、前記のような状況に鑑み、吸音材の
吹き抜けによる吸音効果の劣下が防止可能な排気
サイレンサ構造の提供を目的しするものである。(Purpose of the invention) In view of the above-mentioned situation, the present invention aims to provide an exhaust silencer structure that can prevent deterioration of the sound absorption effect due to the blow-through of the sound absorption material.
（考案の構成）
本考案の排気サイレンサ構造は、多孔排気管内
を流れる排気ガスの排気音を吸収するために、多
孔排気管を囲んで外周に吸音材が配設される排気
サイレンサ構造において、前記多孔排気管の断面
の径を、ガス流方向下流部分の径がガス流方向上
流部分の径より太くなるように形成し、
前記下流部分の太径部分の孔部開口率（排気管
の単位面積当りの孔部開口面積）が前記上流部分
の小径部分の孔部開口率より大きくなるよう、多
面積または多数の孔部を下流部分に開設したこと
を特徴とする。(Structure of the invention) The exhaust silencer structure of the invention includes the above-mentioned exhaust silencer structure in which a sound-absorbing material is disposed on the outer periphery surrounding a porous exhaust pipe in order to absorb the exhaust sound of exhaust gas flowing inside the porous exhaust pipe. The diameter of the cross section of the porous exhaust pipe is formed so that the diameter of the downstream part in the gas flow direction is larger than the diameter of the upstream part in the gas flow direction, and the pore opening ratio (unit area of the exhaust pipe) of the large diameter part of the downstream part is It is characterized in that a large area or a large number of holes are provided in the downstream portion so that the perforation opening area) is larger than the hole opening ratio of the small diameter portion of the upstream portion.
ここでガス流方向とは、排気系内を排気ガスの
流れる方向であり、上流とは、エンジン装置に近
い側、下流とは排気孔に近い側を意味するものと
する。 Here, the gas flow direction is the direction in which exhaust gas flows within the exhaust system, and upstream means the side closer to the engine device, and downstream means the side closer to the exhaust hole.
（実施例）
以下図面を用いて本考案による排気サイレンサ
の実施例を説明する。(Example) An example of the exhaust silencer according to the present invention will be described below with reference to the drawings.
第１図は、エンジンの排気系の一例を示す概略
図である。エンジン４より排出させた排気ガス
は、キヤタリストコンバータ５を通過し、プリマ
フラ６メインマフラ７で消音され外部へ排出され
る。 FIG. 1 is a schematic diagram showing an example of an engine exhaust system. Exhaust gas discharged from the engine 4 passes through a catalyst converter 5, is muffled by a pre-muffler 6 and a main muffler 7, and is discharged to the outside.
本考案による排気サイレンサ構造は、プリマフ
ラ６にもメインマフラ７にも適用される。 The exhaust silencer structure according to the present invention is applied to both the pre-muffler 6 and the main muffler 7.
第２図は本考案による排気サイレンサ構造の一
実施例の断面図である。図示の排気サイレンサ構
造は、多数の小孔が形成された多孔排気管１０の
外周に吸音材１１を配設し、該吸音材１１をケー
シング１２によつて囲んでなるものである。この
排気サイレンサの内部を矢印Ａ方向に排気ガスが
流れる。排気サイレンサの内部を貫通する多孔排
気管１０はガス流方向上流部分１０ａからガス流
方向下流部分１０ｂにむかつて、断面径が次第に
大きくなるよう形成されている。すなわちガス流
方向上流部分１０ａの排気管がガス流方向下流部
分１０ｂの排気管にくらべ細い略円錐型の筒状を
なす。 FIG. 2 is a sectional view of an embodiment of the exhaust silencer structure according to the present invention. The illustrated exhaust silencer structure is constructed by disposing a sound absorbing material 11 around the outer periphery of a porous exhaust pipe 10 in which a large number of small holes are formed, and surrounding the sound absorbing material 11 with a casing 12. Exhaust gas flows inside this exhaust silencer in the direction of arrow A. The porous exhaust pipe 10 that penetrates the inside of the exhaust silencer is formed so that its cross-sectional diameter gradually increases from the upstream portion 10a in the gas flow direction to the downstream portion 10b in the gas flow direction. That is, the exhaust pipe in the upstream portion 10a in the gas flow direction has a substantially conical cylindrical shape that is thinner than the exhaust pipe in the downstream portion 10b in the gas flow direction.
さらに、この多孔排気管１０の表面に開設され
た単位面積当りの孔部の開口面積（孔部開口率）
が排気管の径の増加に伴つて広くなるよう、テー
パ状に形成された排気管１０の断面径の細い部分
に形成される孔部１３ａより径の太い部分に形成
される孔部１３ｂの面積を広くし、また孔の数を
多数とする。本実施例においては、上流部分１０
ａに並べ多径且つ多数の孔部を下流部分１０ｂに
開孔し、細管部分より太管部分の開口部の面積を
広く形成したが、上流部分１０ａと同面積の孔部
を下流部分１０ｂに多数開孔してもよく又上流部
分１０ａ下流部分１０ｂの孔部数を同数として下
流部分１０ｂの孔部の面積を大きくしてもよい。
すなわち多孔排気管１０の断面の径の増大に伴つ
て孔部開口率が大きくなるよう孔部が開設されれ
ばよい。 Furthermore, the opening area of the holes per unit area (hole opening ratio) provided on the surface of the porous exhaust pipe 10
The area of the hole 13b formed in the part with a larger diameter than the hole 13a formed in the part with a narrower cross-sectional diameter of the exhaust pipe 10 formed in a tapered shape so that the diameter becomes wider as the diameter of the exhaust pipe increases. The holes should be made wider and the number of holes should be increased. In this embodiment, the upstream portion 10
A, a large number of holes with multiple diameters are formed in the downstream portion 10b, and the area of the opening in the thick tube portion is wider than that in the thin tube portion. A large number of holes may be formed, or the number of holes in the upstream portion 10a and the downstream portion 10b may be the same, and the area of the holes in the downstream portion 10b may be increased.
That is, the holes may be opened so that the hole opening ratio increases as the diameter of the cross section of the porous exhaust pipe 10 increases.
前記多孔排気管１０の外周にはグラスウール等
の吸音材１１からなる吸音層が形成される。本実
施例においては、ケーシング１２の断面径が、ガ
ス流方向上流部分１０ａとガス流方向下流部分１
０ｂとが同径に形成されているため多孔排気管１
０の断面径の増加に伴い上流部分の吸音層１１ａ
の厚みより下流部分の吸音層１１ｂの厚みが薄い
吸音層が形成されている。ここでさらに効果的に
吸音を行うには、第３図に示すように、ケーシン
グ２２を略円筒形に形成しガス流方向上流部分の
断面径２２ａよりガス流方向下流部分の断面径２
２ｂを太径に形成する必要がある。その際多孔排
気管２０の上流部分２０ａと下流部分２０ｂの断
面径増加率よりケーシング２２の上流部分断面径
２２ａと下流部分断面径２２ｂの増加率を大きく
するのがより好ましい。本実施例においても、第
２図における実施例と同様に多孔排気管２０の小
径部分の孔部２３ａより太径部分の孔部２３ｂを
多数または多面積に形成し、その外周に吸音層２
１を設けることにより、孔部の開口面積の増加に
伴つて吸音率を増加させ、下流部分においてより
効果的な吸音が可能となる。 A sound absorbing layer made of a sound absorbing material 11 such as glass wool is formed on the outer periphery of the porous exhaust pipe 10. In this embodiment, the cross-sectional diameter of the casing 12 is the same as the upstream portion 10a in the gas flow direction and the downstream portion 1 in the gas flow direction.
0b are formed to have the same diameter, so the porous exhaust pipe 1
As the cross-sectional diameter of 0 increases, the sound absorption layer 11a in the upstream portion
A sound absorbing layer is formed that is thinner than the thickness of the sound absorbing layer 11b in the downstream portion. In order to more effectively absorb sound, as shown in FIG. 3, the casing 22 is formed into a substantially cylindrical shape so that the cross-sectional diameter 22a of the upstream portion in the gas flow direction is smaller than the cross-sectional diameter 22a of the downstream portion in the gas flow direction.
It is necessary to form 2b with a large diameter. In this case, it is more preferable that the increase rate of the upstream section diameter 22a and downstream section diameter 22b of the casing 22 is larger than the increase rate of the section diameter of the upstream section 20a and downstream section 20b of the porous exhaust pipe 20. In this embodiment as well, similar to the embodiment shown in FIG.
1, the sound absorption coefficient increases as the opening area of the hole increases, making it possible to more effectively absorb sound in the downstream portion.
これらの実施例のように多孔排気管の断面の径
を，ガス流方向下流部分を上流部分より徐々に太
くなるよう略円錐型に形成することにより排気管
内の排気ガスの流速を徐々に変化させ下流部分の
排気管の負圧を低くすることができる。すなわち
均一な断面径を有する排気管を備えた排気サイレ
ンサ構造は、下流部分の排気管に上流部分の排気
管より大きな負圧がかかるが、下流部分の排気管
の径を太くしたことで、排気ガス流による負圧を
下流部において小さくすることが可能となり、負
圧の低下に伴つて孔部開口率を増加させることが
可能となる。 As in these embodiments, the cross-sectional diameter of the porous exhaust pipe is formed into a substantially conical shape so that the downstream part in the gas flow direction is gradually thicker than the upstream part, thereby gradually changing the flow velocity of the exhaust gas in the exhaust pipe. The negative pressure in the downstream exhaust pipe can be lowered. In other words, with an exhaust silencer structure that has an exhaust pipe with a uniform cross-sectional diameter, a larger negative pressure is applied to the exhaust pipe in the downstream part than in the exhaust pipe in the upstream part, but by increasing the diameter of the exhaust pipe in the downstream part, the exhaust It becomes possible to reduce the negative pressure caused by the gas flow in the downstream portion, and it becomes possible to increase the pore opening ratio as the negative pressure decreases.
（考案の効果）
本考案による排気サイレンサ構造は、ガス流方
向下流の多孔排気管の断面の径をガス流方向上流
の断面の径より太く形成し、かつ排気管の単位面
積当りの孔部の開口面積を、排気管の断面の径の
増加に伴つて大きく形成したことにより、下流部
分のガス流速を上流部分より遅くすることが可能
で、このため下流部分の多孔排気管内の負圧が上
流部分に比較して小さくなる。さらに負圧の大き
い部分である上流部分の孔部開口面積は小さく負
圧の小さい部分である下流部分の孔部開口面積を
大きくするため、上流部分の多孔排気管の外周の
吸音材は、排気管内へ吸引される率が減少し、ま
た下流部分は孔部面積が大きくても負圧が低いた
め吸引力が弱く、吸音材の減少が防止でき、さら
に孔部面積が広いため消音効果が増すものであ
る。(Effects of the invention) The exhaust silencer structure according to the invention has a cross-sectional diameter of the porous exhaust pipe downstream in the gas flow direction larger than that of the cross-section upstream in the gas flow direction, and the number of holes per unit area of the exhaust pipe is By increasing the opening area as the cross-sectional diameter of the exhaust pipe increases, it is possible to make the gas flow velocity in the downstream part slower than in the upstream part, and as a result, the negative pressure in the porous exhaust pipe in the downstream part is lower than that in the upstream part. Be small compared to the portion. Furthermore, in order to increase the hole opening area in the upstream section, where the negative pressure is large, and the downstream section, where the negative pressure is small, the sound absorbing material on the outer periphery of the porous exhaust pipe in the upstream section is The rate of suction into the pipe is reduced, and even if the hole area is large in the downstream area, the negative pressure is low, so the suction force is weak, preventing the loss of sound-absorbing material, and the large hole area increases the sound deadening effect. It is something.
上記のように本考案による排気サイレンサ構造
においては、長期使用によつても、吸音効果を落
とすことなく、確実な消音を行つて排気ガスを排
出することができる。 As described above, in the exhaust silencer structure according to the present invention, even after long-term use, exhaust gas can be discharged with reliable noise reduction without reducing the sound absorption effect.
第１図は排気系の概略図、第２図は、本考案に
よる排気サイレンサの一実施例の水平方向の断面
図、第３図は、本考案による排気サイレンサ構造
の他の実施例の水平方向の断面図、第４図は、従
来例の水平方向の断面図、第５図は、さらに異な
る従来例の水平方向の断面図である。
１０，２０……多孔排気管、１１，２１……吸
音材、１２，２２……ケーシング、１３ａ，２３
ａ，１３ｂ，２３ｂ……孔部。
FIG. 1 is a schematic diagram of the exhaust system, FIG. 2 is a horizontal sectional view of one embodiment of the exhaust silencer according to the present invention, and FIG. 3 is a horizontal cross-sectional view of another embodiment of the exhaust silencer structure according to the present invention. FIG. 4 is a horizontal cross-sectional view of a conventional example, and FIG. 5 is a horizontal cross-sectional view of a still different conventional example. 10, 20... Porous exhaust pipe, 11, 21... Sound absorbing material, 12, 22... Casing, 13a, 23
a, 13b, 23b... hole.
Claims (1)
サイレンサ構造において、前記多孔排気管の排気
ガス流方向下流部分の径を排気ガス流方向上流部
分の径より大径に形成し、さらに前記排気ガス流
方向上流部分の孔部の開口率より前記排気ガス流
方向下流部分の孔部の開口率を大にしたことを特
徴とする排気サイレンサ構造。 In an exhaust silencer structure in which a sound absorbing material is arranged around the outer periphery of a porous exhaust pipe, a diameter of a downstream portion of the porous exhaust pipe in the exhaust gas flow direction is formed to be larger than a diameter of an upstream portion in the exhaust gas flow direction; An exhaust silencer structure characterized in that the aperture ratio of the holes in the downstream part in the exhaust gas flow direction is larger than the aperture ratio of the holes in the upstream part in the exhaust gas flow direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1986060747U JPH0437219Y2 (en) | 1986-04-22 | 1986-04-22 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1986060747U JPH0437219Y2 (en) | 1986-04-22 | 1986-04-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62171609U JPS62171609U (en) | 1987-10-30 |
| JPH0437219Y2 true JPH0437219Y2 (en) | 1992-09-02 |
Family
ID=30893439
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1986060747U Expired JPH0437219Y2 (en) | 1986-04-22 | 1986-04-22 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0437219Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104220121B (en) * | 2012-03-27 | 2016-11-09 | 帝人制药株式会社 | Silencer and possess its oxygen concentrating device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5431237U (en) * | 1977-08-05 | 1979-03-01 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60170100U (en) * | 1984-04-20 | 1985-11-11 | 松下精工株式会社 | Silencer for axial blower |
-
1986
- 1986-04-22 JP JP1986060747U patent/JPH0437219Y2/ja not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5431237U (en) * | 1977-08-05 | 1979-03-01 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62171609U (en) | 1987-10-30 |
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