JPH0218261Y2 - - Google Patents

Description

【考案の詳細な説明】 〔産業上の利用分野〕 共鳴器の咽喉管と排気導入管とを同軸上に設
け、導入管から吐出する排気圧力を共鳴器に導く
構造を持つ内燃機関の消音器（例えば実公昭54−
44089号・実開昭58−104311号公報参照）に関す
る。[Detailed description of the invention] [Industrial application field] A muffler for an internal combustion engine that has a structure in which the throat pipe of the resonator and the exhaust gas introduction pipe are coaxially arranged, and the exhaust pressure discharged from the gas introduction pipe is guided to the resonator. (For example, Jikko 54-
44089 and Utility Model Application Publication No. 104311/1983).

〔従来の技術〕[Conventional technology]

上記構造の共鳴器は一般にパルス・クツシヨン
チヤンバと呼ばれ、排気ガス流が咽喉管内で圧力
を活性化する為共鳴器が励振を受けやすくなり減
衰量を増大する。 A resonator having the above structure is generally referred to as a pulse cushion chamber, and the exhaust gas flow activates pressure within the throat tube, making the resonator more susceptible to excitation and increasing attenuation.

一方、自動車やオートバイの様に、エンジン回
転が常に変動するものにおいては、排気圧力も変
動し減衰量の増減がある。又、特に自動車におけ
る消音器の共鳴器はほとんどと云つてよい程低周
波音に当てられている。これは周知の如く、エン
ジン回転の基本次数が低周波であり、この周波数
が室内へのこもり音につながる為であるのと、
中・高周波数は比較的他の消音手段で容易に対処
出来ることにある。 On the other hand, in vehicles such as automobiles and motorcycles where the engine rotation always fluctuates, the exhaust pressure also fluctuates and the amount of attenuation increases or decreases. Furthermore, most of the resonators of mufflers, particularly in automobiles, are used for low-frequency sounds. This is because, as is well known, the fundamental order of engine rotation is low frequency, and this frequency leads to muffled noise inside the room.
The problem lies in the fact that medium and high frequencies can be dealt with relatively easily by other noise reduction means.

〔考案が解決しようとする課題〕[The problem that the idea aims to solve]

この様に低周波成分を主体に考えると、容積を
大きく、咽喉管も太く、長くした構造が減衰量と
しては理想であるが、実車のレイアウトの関係で
決められた容積内で対処せざるを得ないから、結
局は小容積の共鳴室、細い咽喉管となる。 Considering mainly low-frequency components in this way, a structure with a large volume and a thick and long throat tube would be ideal in terms of attenuation, but it must be dealt with within the volume determined by the layout of the actual vehicle. In the end, it becomes a small-volume resonance chamber and a narrow throat tube.

ところが細い咽喉管を用いる場合は、エンジン
回転が低い場合や減速時においては咽喉管に受け
る排気圧力も低下し、結果的には減衰効果も低下
してしまう。 However, when a narrow throat tube is used, the exhaust pressure applied to the throat tube decreases when the engine speed is low or during deceleration, resulting in a decrease in the damping effect.

本考案は、これらの問題に鑑みて排気圧力が低
下しても細い咽喉管でも減衰効果を低下させる事
のない構造を提供することを目的とする。 In view of these problems, it is an object of the present invention to provide a structure that does not reduce the damping effect even if the exhaust pressure decreases even if the throat tube is narrow.

〔課題を解決するための手段〕[Means to solve the problem]

本考案は、排気導入管２と共鳴器３の咽喉管４
とを同一軸線上に対向させた消音器において、導
入管２を咽喉管４の近くにおいてテーパ状に絞
り、その先端２ａの開口を咽喉管４の開口径より
も小さく形成してその両開口を近接対向させ、上
記テーパ絞り部を含む導入管の周面にパンチング
開口５を設けた構成とする。 The present invention consists of an exhaust introduction pipe 2 and a throat pipe 4 of the resonator 3.
In the muffler, the introduction tube 2 is tapered near the throat tube 4, and the opening at the tip 2a is formed smaller than the opening diameter of the throat tube 4, so that both openings are closed. A punching opening 5 is provided on the circumferential surface of the introduction pipe including the tapered constriction part so as to face each other closely.

〔作用〕[Effect]

導入管２を咽喉管４の近くにおいてテーパ状に
絞り、その先端２ａの開口とその開口より大きい
開口の咽喉管４の開口とを近接対向させたから、
エンジン回転が低く排気流圧が低い場合でも、ま
た咽喉管が細径でも排気ガスは導入管２のテーパ
部から噴射直進的に主として咽喉管４に流入す
る。高速回転時には排気ガスはパンチング開口５
からも流れ出るので背圧損失によりエンジン出力
が低下することはない。またテーパ部の周囲に生
ずる負圧姿勢も、咽喉管内の圧力活性化に有効に
作用し、相まつてエンジンの運転状態の変動に拘
らず常に本来の低周波音減量の機能を理想的に発
揮する。 The introduction tube 2 is tapered near the throat tube 4, and the opening at the tip 2a and the opening of the throat tube 4, which is larger than the opening, are closely opposed to each other.
Even when the engine speed is low and the exhaust flow pressure is low, and even if the throat tube has a small diameter, the exhaust gas primarily flows into the throat tube 4 in a straight injection manner from the tapered portion of the introduction tube 2. During high speed rotation, exhaust gas flows through the punched opening 5.
Since it also flows out from the engine, there is no reduction in engine output due to back pressure loss. In addition, the negative pressure generated around the tapered part effectively activates the pressure inside the throat canal, and this means that the original low-frequency sound reduction function is always ideally exhibited regardless of changes in engine operating conditions. .

〔実施例〕〔Example〕

第１図は、共鳴器３、第１・第２の膨張室６，
７、結合管８、排出管９からなる消音器を例示す
る、消音器の全体構成は限定されるものではな
い。 FIG. 1 shows a resonator 3, first and second expansion chambers 6,
7, a silencer consisting of a coupling pipe 8 and a discharge pipe 9 is exemplified, but the overall structure of the silencer is not limited.

第２図〜第６図は導入管２の先端２ａの絞り形
状の例を示すもので、第２図・第３図は円錐形、
第４図は円錐形部の先端に細管２ａ１を形成した
例、第５図・第６図は放射四方向２ａ２をテーパ
状に絞つた例で、いずれも先端２ａの開口径を咽
喉管４の開口径Ｄより小さくしたものである。 Figures 2 to 6 show examples of the constricted shape of the tip 2a of the introduction tube 2, and Figures 2 and 3 are conical,
Fig. 4 shows an example in which a thin tube 2a1 is formed at the tip of the conical part, and Figs. 5 and 6 show examples in which the four radial directions 2a2 are tapered. The opening diameter is smaller than D.

〔考案の効果〕[Effect of idea]

前記作用の項に記載の理由で、小容積の共鳴
室、細い咽喉管でも理想的に機能し、自動車のレ
イアウトに応じた大きさの共鳴型消音器が得られ
る。 For the reasons described in the above-mentioned operation section, it is possible to obtain a resonance type muffler that functions ideally even in a small-volume resonance chamber and a narrow throat tube, and whose size corresponds to the layout of the automobile.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本考案を実施した消音器の縦断面図、
第２図乃至第６図は導入管の先端形状の説明図。 １は消音器、２は導入管、３は共鳴器、４は咽
喉管、Ｄはその直径、５はパンチング開口、２ａ
は導入管の先端。 Figure 1 is a vertical cross-sectional view of a silencer implementing the present invention.
FIGS. 2 to 6 are explanatory diagrams of the shape of the tip of the introduction tube. 1 is a silencer, 2 is an introduction tube, 3 is a resonator, 4 is a throat tube, D is its diameter, 5 is a punching opening, 2a
is the tip of the introduction tube.

Claims (1)

【実用新案登録請求の範囲】 排気導入管と共鳴器の咽喉管とを同一軸線上に
対向させた消音器において、 導入管を咽喉管の近くにおいてテーパ状に絞
り、その先端の開口を咽喉管の開口径よりも小さ
く形成してその両開口を近接対向させ、上記テー
パ絞り部を含む導入管の周面にパンチング開口を
設けたことを特徴とする内燃機関の消音器。[Scope of Claim for Utility Model Registration] In a silencer in which an exhaust inlet pipe and a throat pipe of a resonator face each other on the same axis, the inlet pipe is tapered near the throat pipe, and the opening at its tip is connected to the throat pipe. 1. A muffler for an internal combustion engine, characterized in that a punching opening is formed on the circumferential surface of the introduction pipe including the tapered throttle part, the opening diameter being smaller than the diameter of the opening, the openings being close to each other and facing each other.