JPS62617A - Exhaust muffler for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent the reduction of the sound suppressing effect of a sound absorbing material by arranging an inner cylinder which has an exhaust taking-in port in the lower part and is charged with sound absorbing material, into an outer cylinder having an exhaust taking-in port in the upper part, thus suppressing the condensation of water portion in the sound absorbing material. CONSTITUTION:An inner cylinder 3 charged with sound absorbing material 20 and 21 is installed into a bottomed cylindrical outer cylinder 2 having an exhaust inlet 5 in the upper part. Said inner cylinder 3 has an exhaust taking-in port 9 in the lower part and an exhaust outlet 10 in the upper part. Therefore, the exhaust introduced from the upper part of the outer cylinder descends, turning in spiral form between the outer and inner cylinders 2 and 3, and the water portion contained in the exhaust contacts with the outer cylinder 2, and is formed into water droplets, and is discharged from a drain discharge hole 6. Further, since the sound absorbing material in the inner cylinder 3 is heated by the exhaust, condensation of water portion in the sound absorbing material can be prevented.

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消音装置に関するものである。[Detailed description of the invention] [Industrial application field] The present invention relates to an exhaust silencer for an internal combustion engine.

〔従来の技術〕[Conventional technology]

一般に内燃機関の排気音を軽減する排気消音装置は、内
部に排気を導入し、グラスウールなどの吸音材で吸音し
たり、共鳴減衰させたり、あるいは排気通路断面積の急
激な拡大により音波を干渉させたりすることにより、爆
発音を軽減するように構成されている。Exhaust silencing devices that reduce exhaust noise from internal combustion engines generally introduce exhaust gas into the interior and either absorb the sound with sound-absorbing materials such as glass wool, attenuate it by resonance, or interfere with sound waves by rapidly expanding the cross-sectional area of the exhaust passage. The structure is designed to reduce explosion noise by

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

しかしながら、従来のこの種の内燃機関の排気消音装置
においては、必ずしも吸音材による消音効果が維持でき
ないという不具合があった。これは、排気温度が低くな
ると、内燃機関の排気中に含まれた水分が凝縮し、この
水分が吸音材に吸収されるためと考えられる。すなわち
、水分によって、吸音材の密度が変化したり、孔が塞が
れたりするため、これが消音効果に影響するものと考え
られる。However, conventional exhaust silencing devices for internal combustion engines of this type have a problem in that the silencing effect of the sound absorbing material cannot always be maintained. This is thought to be because when the exhaust gas temperature becomes low, moisture contained in the exhaust gas from the internal combustion engine condenses, and this moisture is absorbed by the sound absorbing material. In other words, moisture changes the density of the sound absorbing material and blocks the pores, which is thought to affect the sound deadening effect.

〔問題点を解決するための手段〕[Means for solving problems]

本発明はこのような事情に鑑みなされたもので、吸音材
による消音効果が維持できる内燃機関の排気消音装置を
徒供するものである。本発明に係る内燃機関の排気消音
装置は、上方に開口された有底筒状の外筒と、この外筒
内に挿入され下方に排気取入口を有し上方に排気出口を
有する内筒とからなり、この内筒内には吸音材を装填し
、前記外筒の上方に排気入口を設けたものである。The present invention was made in view of these circumstances, and provides an exhaust muffling device for an internal combustion engine that can maintain the muffling effect of the sound absorbing material. The exhaust silencing device for an internal combustion engine according to the present invention includes an outer cylinder having a bottomed cylindrical shape that is opened upward, and an inner cylinder that is inserted into the outer cylinder and has an exhaust intake in the lower part and an exhaust outlet in the upper part. A sound absorbing material is loaded into the inner cylinder, and an exhaust inlet is provided above the outer cylinder.

〔作用〕[Effect]

本発明においては、内筒を外筒中を通る排気熱で加熱す
ることにより、内筒内を通過する排気中の水分が凝縮す
るのを防止する。In the present invention, moisture in the exhaust gas passing through the inner cylinder is prevented from condensing by heating the inner cylinder with exhaust heat passing through the outer cylinder.

〔実施例〕〔Example〕

以下、本発明の一実施例を図により詳細に説明する。第
１図は本発明に係る内燃機関の排気消音装置を示す断面
図、第２図は第１図のｎ−ｎ線断面図で、これらの図に
おいて符号１で示すものは排気消音装置を示し、この排
気消音装置１は図示しないエンジンの排気口に接続され
た排気管の途中に設けられており、上方に開口を有する
外筒２と、この外筒２内に前記開口側から長手方向に挿
入された内筒３などから構成されている。外筒２は樹脂
材から球面状の底部を有する円筒状に形成されている。Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an exhaust silencing device for an internal combustion engine according to the present invention, and FIG. 2 is a sectional view taken along line nn in FIG. , this exhaust silencer 1 is installed in the middle of an exhaust pipe connected to an exhaust port of an engine (not shown), and includes an outer cylinder 2 having an opening at the top, and a cylinder extending longitudinally from the opening side into the outer cylinder 2. It is composed of an inserted inner cylinder 3 and the like. The outer cylinder 2 is formed from a resin material into a cylindrical shape with a spherical bottom.

このため、周壁には抜き勾配が設けられている。また、
外筒２の上方には排気管から排気を導入する排気人口４
が設けられている。この排気人口４は排気を外筒２の内
周面に沿って案内するように、内周面の接線方向に開口
されている。５は排気人口４を排気管に接続するための
金属製の接続管であり、排気人口４に挿入され接着され
ている。６は外筒２の底部に開口されたドレン排出孔で
、接続管７を介して鎖線で示すドレンタンク８に接続さ
れている。For this reason, the peripheral wall is provided with a draft angle. Also,
Exhaust population 4 where exhaust is introduced from the exhaust pipe above the outer cylinder 2
is provided. The exhaust port 4 is opened in the tangential direction of the inner circumferential surface of the outer cylinder 2 so as to guide the exhaust gas along the inner circumferential surface of the outer cylinder 2. 5 is a metal connecting pipe for connecting the exhaust port 4 to the exhaust pipe, and is inserted into the exhaust port 4 and bonded. Reference numeral 6 denotes a drain discharge hole opened at the bottom of the outer cylinder 2, which is connected via a connecting pipe 7 to a drain tank 8 shown by a chain line.

前記内筒３は外筒２と同様に樹脂材から円筒状に形成さ
れており、下方には内筒３内を外筒２内と連通ずる排気
取入口９が設けられ、上方には内筒３内と外部とを連通
ずる排気出口１０が径方向に設けられている。内筒３の
内部は内周面に一体に立設された隔壁１１と、この隔壁
１１の上方および下方に設けられた隔壁１２および隔壁
１３によって、共鳴室１４および膨張室１５．１５に画
成されている。また、内筒３の上部には内筒３と外筒２
との間を閉塞する蓋体１７が一体に設けられている。The inner cylinder 3 is formed into a cylindrical shape from a resin material like the outer cylinder 2, and is provided with an exhaust intake port 9 on the lower side that communicates the inside of the inner cylinder 3 with the inside of the outer cylinder 2, and on the upper side is an exhaust intake port 9 that communicates the inside of the inner cylinder 3 with the inside of the outer cylinder 2. An exhaust outlet 10 is provided in the radial direction to communicate between the inside of 3 and the outside. The interior of the inner cylinder 3 is divided into a resonance chamber 14 and an expansion chamber 15, 15 by a partition wall 11 integrally erected on the inner peripheral surface, and partition walls 12 and 13 provided above and below this partition wall 11. has been done. In addition, the upper part of the inner cylinder 3 has an inner cylinder 3 and an outer cylinder 2.
A lid body 17 is integrally provided to close the space between the two.

２０は前記膨張室１５．１６に装填された第１の吸音材
で、ニットメツシュや金網などからなる抵抗型の吸音材
であり、低周波音を減衰する。２１は共鳴室１４に装填
された高周波音を減衰する第２の吸音材である。この第
２の吸音材２１は、グラスウールやスチールウールなど
からなり、前記隔壁１１．１２間に支持された多数の孔
を有するパンチングメタルパイプ２２と内筒３の内周面
との間に保持されている。Reference numeral 20 denotes a first sound absorbing material loaded in the expansion chambers 15 and 16, which is a resistance type sound absorbing material made of knit mesh, wire gauze, etc., and attenuates low frequency sounds. 21 is a second sound absorbing material loaded into the resonance chamber 14 and attenuating high frequency sound. This second sound absorbing material 21 is made of glass wool, steel wool, etc., and is held between the inner peripheral surface of the inner cylinder 3 and a punched metal pipe 22 having a large number of holes supported between the partition walls 11 and 12. ing.

２３は排気出口ｌＯを下流側の排気管と接続する接続管
、２４は排気消音装置１を取付けるためのブラケットで
あり、内筒３と一体に形成されている。23 is a connecting pipe that connects the exhaust outlet lO with the exhaust pipe on the downstream side, and 24 is a bracket for mounting the exhaust silencer 1, which is formed integrally with the inner cylinder 3.

このように構成された内燃機関の排気消音装置において
は、排気人口４から外筒２内に導入された排気は、矢印
で示すように外筒２の内周面と内筒３の外周面との間を
螺旋状に旋回しながら下降する。このとき、排気中に水
滴が含まれている場合は、この水滴に遠心力が作用する
と共に外気により冷却されてる外筒２への接触により、
排気中から水分を分離することができる。分離された水
分は外筒２の内周面に沿って流下し、ドレン排出孔６か
ら排出される。In the exhaust silencer for an internal combustion engine configured in this way, the exhaust gas introduced into the outer cylinder 2 from the exhaust port 4 travels between the inner peripheral surface of the outer cylinder 2 and the outer peripheral surface of the inner cylinder 3 as shown by the arrows. It descends while spiraling between the two. At this time, if there are water droplets in the exhaust gas, centrifugal force acts on these water droplets and they come into contact with the outer cylinder 2, which is cooled by the outside air.
Moisture can be separated from exhaust gas. The separated water flows down along the inner peripheral surface of the outer cylinder 2 and is discharged from the drain hole 6.

外筒２の下方に流れた排気は球面状の底部によって流れ
の方向が反転されて上方に向かい、排気取入口９から内
筒３内へ流入する。内筒３内において、排気は先ず膨張
室ｌＧ内の第１の吸音材２０で低周波音が減衰される０
次いで共鳴室１４内の第２の吸音材２１で高周波音が減
衰され、さらに膨張室１５内の第１の吸音材２０で再び
低周波音が減衰された後、排気出口ｌＯから排出される
。ここで、異なる種類の第１の吸音材２０と第２の吸音
材２１との組み合わせによって、消音効果が高められて
いる。　・ また、外筒２内に流入した排気は内筒３の外周面に接触
しながら下降するので、内筒３を排気の熱を利用して加
熱することができる。換言すれば、外筒２内に流入した
直後の温度が高い排気で内筒３内の吸音材が加熱される
。このため、内筒３内の第１の吸音材２０．２０や第２
の吸音材２１が保温されるので、ここを通過する排気中
の水分が凝縮するのを防止することができる。The flow direction of the exhaust gas that has flowed downward through the outer cylinder 2 is reversed by the spherical bottom portion, heads upward, and flows into the inner cylinder 3 through the exhaust intake port 9. In the inner cylinder 3, the exhaust gas first has low frequency sounds attenuated by the first sound absorbing material 20 in the expansion chamber 1G.
Next, the high-frequency sound is attenuated by the second sound-absorbing material 21 in the resonance chamber 14, and the low-frequency sound is further attenuated again by the first sound-absorbing material 20 in the expansion chamber 15, and is then exhausted from the exhaust outlet IO. Here, the combination of different types of first sound absorbing material 20 and second sound absorbing material 21 enhances the sound deadening effect. - Moreover, since the exhaust gas that has flowed into the outer cylinder 2 descends while contacting the outer peripheral surface of the inner cylinder 3, the inner cylinder 3 can be heated using the heat of the exhaust gas. In other words, the sound absorbing material in the inner cylinder 3 is heated by the high-temperature exhaust gas that has just flown into the outer cylinder 2 . For this reason, the first sound absorbing material 20.20 and the second sound absorbing material inside the inner cylinder 3 are
Since the sound absorbing material 21 is kept warm, moisture in the exhaust gas passing through it can be prevented from condensing.

〔発明の効果〕〔Effect of the invention〕

以上説明したように本発明によれば、上方に開ロされた
有底筒状の外筒と、この外筒内に挿入され下方に排気取
入口を有し上方に排気出口を有する内筒とからなり、こ
の内筒内には吸音材を装填し、前記外筒の上方に排気入
口を設けたから、吸音材を外筒中を通る排気熱で加熱す
ることができる。As explained above, according to the present invention, there is provided an outer cylinder having a cylindrical shape with a bottom that opens upward, and an inner cylinder that is inserted into the outer cylinder and has an exhaust intake in the lower part and an exhaust outlet in the upper part. Since a sound absorbing material is loaded into the inner cylinder and an exhaust inlet is provided above the outer cylinder, the sound absorbing material can be heated by exhaust heat passing through the outer cylinder.

したがって、吸音材内を通過する排気中の水分が凝縮す
るのを防止することができるから、長期間にわたって吸
音材の消音効果を維持することができる。Therefore, since it is possible to prevent moisture in the exhaust gas passing through the sound absorbing material from condensing, the sound damping effect of the sound absorbing material can be maintained for a long period of time.

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

第１図は本発明に係る内燃機関の排気消音装置を示す断
面図、第２図は第１図のｌ１ｊ−ｆｆ線断面図である。 ２・・・・外筒、３・・・・内筒、４・・・・排気入口
、９・・・・排気取入口、１０・・・・排気出口、２０
・・・・第１の吸音材、２１・・・・第２の吸音材。 Ｌ、　　　、−ＪFIG. 1 is a sectional view showing an exhaust muffler for an internal combustion engine according to the present invention, and FIG. 2 is a sectional view taken along the line l1j-ff in FIG. 2...Outer cylinder, 3...Inner cylinder, 4...Exhaust inlet, 9...Exhaust intake port, 10...Exhaust outlet, 20
...First sound absorbing material, 21... Second sound absorbing material. L, , -J

Claims (1)

【特許請求の範囲】[Claims] 上方に開口を有する有底筒状の外筒と、この外筒内に前
記開口側から挿入され下方に排気取入口を有し上方に排
気出口を有する内筒とからなり、この内筒内には吸音材
が装填されており、前記外筒の上方には排気入口が設け
られてなる内燃機関の排気消音装置。It consists of a bottomed cylindrical outer cylinder having an opening at the top, and an inner cylinder which is inserted into the outer cylinder from the opening side and has an exhaust intake port at the bottom and an exhaust outlet at the top. An exhaust silencing device for an internal combustion engine, which is loaded with a sound absorbing material and has an exhaust inlet above the outer cylinder.