JP3326996B2 - Automotive exhaust silencer - Google Patents
Automotive exhaust silencerInfo
- Publication number
- JP3326996B2 JP3326996B2 JP24635594A JP24635594A JP3326996B2 JP 3326996 B2 JP3326996 B2 JP 3326996B2 JP 24635594 A JP24635594 A JP 24635594A JP 24635594 A JP24635594 A JP 24635594A JP 3326996 B2 JP3326996 B2 JP 3326996B2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- exhaust
- opening
- urging means
- rotation
- 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 - Lifetime
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
- F01N1/16—Silencing apparatus characterised by method of silencing by using movable parts
- F01N1/166—Silencing apparatus characterised by method of silencing by using movable parts for changing gas flow path through the silencer or for adjusting the dimensions of a chamber or a pipe
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Silencers (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、自動車等の排気系から
発生する騒音を低減する自動車用排気消音装置の改良に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an exhaust muffler for an automobile which reduces noise generated from an exhaust system of an automobile or the like.
【０００２】[0002]
【従来の技術】従来の自動車用排気消音装置としては、
エンジンの低回転域の排気騒音を低減するとともに、同
じく高回転域の排気損失を低減しながら排気騒音の低減
を行うものが提案されており、例えば特開昭６４−６０
７０９号公報に開示されるようなものが知られている。2. Description of the Related Art Conventional exhaust silencers for automobiles include:
Japanese Patent Application Laid-Open No. Sho 64-60 discloses a technique for reducing exhaust noise in a low engine speed range while also reducing exhaust loss in a high engine speed range.
The one disclosed in Japanese Patent Publication No. 709 is known.
【０００３】これは、エンジンの低回動域における排気
騒音の低減を重視する第１の排気管路と、エンジンの高
回転域における排気騒音の低減を重視する第２の排気管
路とを備えたマフラにおいて、第２の排気管路に介装し
た制御弁をエンジンの低回転域で閉弁する一方、高回転
域で開弁するもので、低回転域では第１の排気管路のみ
で排気を行う一方、高回転域では第１及び第２の排気管
路により排気を行うことで排気損失の増大を抑制しなが
ら騒音を低減するものである。[0003] This is provided with a first exhaust line emphasizing reduction of exhaust noise in a low rotation region of the engine and a second exhaust line emphasis on reduction of exhaust noise in a high rotation region of the engine. In the muffler, the control valve interposed in the second exhaust pipe is closed at a low engine speed while the valve is opened at a high engine speed. In the low engine speed range, only the first exhaust pipe is used. On the other hand, in the high rotation range, the exhaust is performed by the first and second exhaust pipes, thereby suppressing an increase in exhaust loss and reducing noise.
【０００４】このような排気消音装置では、制御弁をエ
ンジンの回転数に応じてモータ等で駆動するため、制御
手段が必要となって装置全体が複雑になるとともに、製
造コストを増大させてしまうという問題があり、特別な
制御手段を必要とすることなく、簡易な構成でありなが
ら、エンジンの低回転域の排気騒音を低減するととも
に、同じく高回転域の排気損失を低減しながら排気騒音
の低減を行う装置を本願出願人は特願平６−９５３３６
号として提案した。In such an exhaust silencer, since the control valve is driven by a motor or the like in accordance with the number of revolutions of the engine, control means is required, so that the entire apparatus becomes complicated and the manufacturing cost increases. This eliminates the need for special control means and reduces the exhaust noise in the low engine speed range while reducing the exhaust noise in the high engine speed range with a simple configuration. The applicant of the present application has disclosed a device for reducing the noise in Japanese Patent Application No. 6-95336.
No. proposed.
【０００５】これについて説明すると、図１３、図１４
に示すように、マフラ９１にはエンジンの排気を常時排
出するテールチューブ８２と、同じく高回転域における
排気を行うテールチューブ８３が配設される。[0005] This will be described with reference to FIGS.
As shown in FIG. 5, a muffler 91 is provided with a tail tube 82 for constantly discharging the exhaust of the engine, and a tail tube 83 for discharging the exhaust in a high rotation speed region.
【０００６】マフラ９１の内部には、エンジンの低回転
域における排気騒音の低減を重視する拡張室９２〜９４
がバッフル板９６、９７によって画成され、排気を導入
するインレットチューブ９９とテールチューブ８２はこ
れら拡張室９２〜９４を介して連通され、さらに、高回
転域における排気騒音を低減する拡張室９５がバッフル
板９８で画成され、この拡張室９５がテールチューブ８
３を介して外部と連通する。[0006] Inside the muffler 91, expansion chambers 92 to 94 emphasizing reduction of exhaust noise in a low engine speed range.
Are defined by baffle plates 96 and 97, an inlet tube 99 for introducing exhaust and a tail tube 82 are communicated through these expansion chambers 92 to 94, and an expansion chamber 95 for reducing exhaust noise in a high rotation range is provided. The expansion chamber 95 is defined by a baffle plate 98,
3 and communicate with the outside.
【０００７】そして、バッフル板９８には拡張室９２、
９５を連通する貫通孔８４と、拡張室９２の内圧に応じ
て貫通孔８４を開閉するバルブ８６が配設され、バルブ
８６はスプリング８７でバッフル板９８へ向けて付勢さ
れる。The baffle plate 98 has an expansion chamber 92,
A through-hole 84 communicating with 95 and a valve 86 that opens and closes the through-hole 84 according to the internal pressure of the expansion chamber 92 are provided. The valve 86 is urged by a spring 87 toward a baffle plate 98.
【０００８】エンジンの低回転域ではバルブ８６が閉弁
してインレットチューブ９９からの排気は拡張室９２〜
９４を介してテールチューブ８２から外部へ排出される
一方、エンジンの高回転域では拡張室９２の内圧が上昇
してバルブ８６が開弁し、低回転域の経路に加えて拡張
室９５を介してテールチューブ８３からも排気が行われ
る。In the low engine speed range, the valve 86 closes and the exhaust from the inlet tube 99 is discharged from the expansion chamber 92 to
On the other hand, the exhaust gas is discharged from the tail tube 82 to the outside via 94, while the internal pressure of the expansion chamber 92 increases in the high rotation range of the engine and the valve 86 opens, and in addition to the path in the low rotation range, the expansion chamber 95 passes through the expansion chamber 95. The exhaust is also performed from the tail tube 83.
【０００９】[0009]
【発明が解決しようとする課題】ところで、上記従来の
装置においては、エンジンの低回転域でバルブ８６を確
実に閉弁して拡張室９５への排気漏れを防ぐ必要があ
り、スプリング８７のバネ定数を大きく設定している。In the above-mentioned conventional apparatus, it is necessary to close the valve 86 securely in the low engine speed range to prevent the exhaust gas from leaking into the expansion chamber 95. The constant is set large.
【００１０】しかしながら、エンジンの高回転域になる
と拡張室９２の内圧の増大に応じてバルブ８６はスプリ
ング８７に抗して開弁するが、バルブ８６の開度に対す
る拡張室９２の内圧の増加分はスプリング８７のバネ定
数が大きさに伴って大きくなり、高回転域における排気
圧力の増大、すなわち、排気損失の増大を効果的に抑制
できず、出力の低下を招く場合があった。However, when the engine speed is high, the valve 86 opens against the spring 87 in response to the increase in the internal pressure of the expansion chamber 92. In this case, the spring constant of the spring 87 increases with the size, and the increase in the exhaust pressure in the high rotation range, that is, the increase in the exhaust loss cannot be effectively suppressed, and the output may decrease in some cases.
【００１１】そこで本発明は、上記問題点に鑑みてなさ
れたもので、エンジンの高回転域における排気損失の増
大を効果的に抑制しながら、全回転域において消音性能
を確保するとともに、製造コストの増大を抑制可能な自
動車用排気消音装置を提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it has been found that while effectively suppressing an increase in exhaust loss in a high engine speed range, it is possible to ensure noise reduction performance in all engine speed ranges and to reduce manufacturing costs. It is an object of the present invention to provide a vehicle exhaust silencer capable of suppressing an increase in the exhaust gas.
【００１２】[0012]
【課題を解決するための手段】第１の発明は、エンジン
の運転状態に応じて排気流路を切り換えて、低回転域と
高回転域での排気騒音を減衰、吸収するようにした自動
車用排気消音装置において、排気圧力に応動して排気流
路を切り換える開閉バルブと、排気圧力に対抗して前記
開閉バルブを閉弁方向に付勢する手段と、前記開閉バル
ブの回動角が所定の値を越えると前記付勢手段の反力の
増分を減少するバネ定数変更手段とを備える。According to a first aspect of the present invention, there is provided a vehicle for an automobile in which an exhaust passage is switched in accordance with an operating state of an engine to attenuate and absorb exhaust noise in a low rotation range and a high rotation range. In an exhaust silencer, an opening / closing valve for switching an exhaust flow path in response to exhaust pressure, means for urging the opening / closing valve in a valve closing direction against exhaust pressure, and a turning angle of the opening / closing valve being a predetermined angle A spring constant changing means for decreasing the increment of the reaction force of the urging means when the value exceeds the value.
【００１３】また、第２の発明は、前記第１の発明にお
いて、前記付勢手段は基端を前記開閉バルブの回動軸か
ら所定の位置に配設される一方、自由端で前記開閉バル
ブに摺接し、付勢手段が摺接する開閉バルブにはバネ定
数変更手段として、開閉バルブの回動角が所定値以下で
はこの回動角に応じて基端を軸に回動する付勢手段の回
動角を第１の比率で増大させる第１の摺接面と、開閉バ
ルブの回動角が所定値を越えると前記第１の比率よりも
小さい第２の比率で回動角に応じて基端を軸に回動する
付勢手段の回動角を増大させる第２の摺接面とをそれぞ
れ形成する。According to a second aspect of the present invention, in the first aspect, the biasing means has a base end disposed at a predetermined position from a rotation axis of the open / close valve, and has a free end provided with the open / close valve at a free end. When the turning angle of the opening / closing valve is equal to or less than a predetermined value, the urging means that pivots around the base end when the turning angle of the opening / closing valve is equal to or less than a predetermined value. A first sliding contact surface for increasing the rotation angle at a first ratio, and a second ratio smaller than the first ratio according to the rotation angle when the rotation angle of the on-off valve exceeds a predetermined value. A second sliding contact surface is formed to increase the rotation angle of the urging means that rotates about the base end.
【００１４】また、第３の発明は、前記第１の発明にお
いて、前記開閉バルブの回動軸は排気消音装置の所定の
外部に配設されたカムと同期的に回動可能に形成され、
前記付勢手段は同じく所定の外部に配設されるととも
に、基端を前記カムの回動軸から所定の位置に配設され
る一方、自由端で前記カムに摺接し、バネ定数変更手段
はこのカムに形成されて開閉バルブの回動角が所定値以
下では開閉バルブの回動角の増大に応じて基端を軸に回
動する付勢手段の回動角を第１の比率で増大させる第１
の摺接面と、開閉バルブの回動角が所定値を越えると前
記第１の比率よりも小さい第２の比率で付勢手段の回動
角を第２の比率で増大させる第２の摺接面とをそれぞれ
形成する。According to a third aspect of the present invention, in the first aspect, the rotating shaft of the open / close valve is formed so as to be capable of rotating synchronously with a cam disposed outside a predetermined outside of the exhaust silencer.
The biasing means is also disposed outside the predetermined outside, and the base end is disposed at a predetermined position from the rotation axis of the cam, while the free end slides on the cam, and the spring constant changing means is When the rotation angle of the opening / closing valve formed on the cam is equal to or less than a predetermined value, the rotation angle of the urging means that rotates about the base end as the rotation angle of the opening / closing valve increases at a first ratio. First
A second sliding means for increasing the rotation angle of the biasing means at a second ratio at a second ratio smaller than the first ratio when the rotation angle of the opening / closing valve exceeds a predetermined value. And a contact surface.
【００１５】また、第４の発明は、前記第１の発明にお
いて、前記バネ定数変更手段は、開閉バルブの回動軸と
開閉バルブが付勢手段へ加える排気圧力の作用点との距
離を増大させて相対的に付勢手段の反力の増分を減少さ
せる。In a fourth aspect based on the first aspect, the spring constant changing means increases a distance between a rotation axis of the on-off valve and a point of application of the exhaust pressure applied to the urging means by the on-off valve. Thus, the increment of the reaction force of the urging means is relatively reduced.
【００１６】また、第５の発明は、前記第４の発明にお
いて、前記付勢手段は基端を前記開閉バルブの回動軸か
ら所定の位置に配設される一方、自由端で前記開閉バル
ブに摺接し、付勢手段が摺接する開閉バルブにはバネ定
数変更手段として、開閉バルブの回動角が所定値以下で
は回動軸から第１の距離で前記付勢手段と摺接する第１
の摺接手段と、開閉バルブの回動角が所定値を越えると
開閉バルブの回動軸から前記第１の距離よりも大きい第
２の距離で付勢手段と摺接する第２の摺接手段とをそれ
ぞれ形成する。In a fifth aspect based on the fourth aspect, the urging means has a base end disposed at a predetermined position from a rotation axis of the opening / closing valve, and has a free end provided with the opening / closing valve at a free end. A spring constant changing means is provided for the opening / closing valve which is in sliding contact with the urging means and which is in sliding contact with the urging means at a first distance from the rotation axis when the rotation angle of the opening / closing valve is a predetermined value or less.
And a second sliding contact means for slidingly contacting the urging means at a second distance greater than the first distance from the pivot axis of the on-off valve when the rotation angle of the on-off valve exceeds a predetermined value. Are formed respectively.
【００１７】また、第６の発明は、エンジンの運転状態
に応じて排気流路を切り換えて、低回転域と高回転域で
の排気騒音を減衰、吸収するようにした自動車用排気消
音装置において、排気圧力に応動して排気流路を切り換
える開閉バルブと、排気圧力に対抗して前記開閉バルブ
を閉弁方向に付勢する手段と、前記開閉バルブの回動角
の増大に応じて前記付勢手段の反力の増分を減少するバ
ネ定数変更手段とを備える。According to a sixth aspect of the present invention, there is provided an exhaust muffler for an automobile in which an exhaust passage is switched in accordance with an operation state of an engine to attenuate and absorb exhaust noise in a low rotation range and a high rotation range. An opening / closing valve for switching an exhaust flow path in response to exhaust pressure; a means for urging the opening / closing valve in a valve closing direction against exhaust pressure; and an opening / closing valve for increasing the rotation angle of the opening / closing valve. Spring constant changing means for reducing the increment of the reaction force of the biasing means.
【００１８】また、第７の発明は、前記第６の発明にお
いて、前記付勢手段は基端を前記開閉バルブの回動軸か
ら所定の位置に配設される一方、自由端で前記開閉バル
ブに摺接し、付勢手段が摺接する開閉バルブにはバネ定
数変更手段として、開閉バルブの回動角の増大に応じて
基端を軸に回動する付勢手段の回動角の増分値を減少す
る所定の曲面を形成する。In a seventh aspect based on the sixth aspect, the biasing means has a base end disposed at a predetermined position from a rotation axis of the opening / closing valve, and has a free end provided with the opening / closing valve at a free end. As the spring constant changing means, the increment value of the turning angle of the urging means which turns around the base end as the turning angle of the on-off valve increases is provided as a spring constant changing means for the on-off valve which is in sliding contact with the urging means. Form a predetermined curved surface that decreases.
【００１９】[0019]
【作用】第１の発明は、消音装置内部の排気圧力が所定
値未満のエンジンの低回転域では、付勢手段の所定のバ
ネ定数によって開閉バルブは確実に閉弁して低回転域の
流路と高回転域の流路とを画成する一方、排気圧力が所
定値を越えるエンジンの高回転域では付勢手段に抗して
バルブは開弁して高回転域の排気流路に切り換える。排
気圧力の増大に応じてバルブの回動角はさらに増大する
が、この回動角が所定値を越えると付勢手段の反力の増
分値が低減されるため、開閉バルブは円滑に開弁して圧
力及び流量の増大した排気を通過させて消音装置の内圧
の増大を抑制することができ、エンジンの高回転域にお
ける排気損失の増大を抑制し、排気圧力に応じて排気流
路を切り換えてエンジンの全回転域での消音を確実に行
いながら出力の低下を抑制する。According to the first aspect of the present invention, in the low rotation range of the engine in which the exhaust pressure inside the muffler is less than a predetermined value, the on-off valve is reliably closed by the predetermined spring constant of the urging means, and the flow in the low rotation range is reduced. On the other hand, in the high rotation range of the engine where the exhaust pressure exceeds a predetermined value, the valve opens to switch to the high rotation range exhaust flow path while the exhaust pressure exceeds a predetermined value. . The turning angle of the valve further increases in accordance with the increase in the exhaust pressure. However, when the turning angle exceeds a predetermined value, the incremental value of the reaction force of the urging means is reduced, so that the on-off valve opens smoothly. As a result, it is possible to suppress the increase in the internal pressure of the silencer by passing the exhaust gas having increased pressure and flow rate, suppress the increase in exhaust loss in the high engine speed range, and switch the exhaust passage according to the exhaust pressure. In this way, the noise reduction is suppressed in the entire engine speed range while reducing the output.
【００２０】また、第２の発明は、付勢手段は基端を開
閉バルブの回動軸から所定の位置に配設されて開閉バル
ブの回動に応じて自由端を回動させ、付勢手段の回動角
度に応じた反力で開閉バルブは閉弁方向へ付勢される。
開閉バルブの回動角が所定値未満では開閉バルブの回動
角に応じて付勢手段は第１の比率で回動角を増大し、回
動角に応じて増大する反力を発生するが、排気圧力が増
大して開閉バルブの回動角が所定値を越えると、付勢手
段は第１の比率よりも小さい第２の比率で回動するた
め、開閉バルブの所定の回動角以上では反力の増分値を
減少させることができ見かけのバネ定数が減少するた
め、開閉バルブは円滑に開弁して圧力及び流量の増大し
た排気を通過させることで消音装置の内圧の増大を抑制
し、エンジンの高回転域における排気損失の増大を抑制
することができる。According to a second aspect of the present invention, the urging means has a base end disposed at a predetermined position from a rotation axis of the opening / closing valve, and rotates the free end in accordance with the rotation of the opening / closing valve. The open / close valve is urged in the valve closing direction by a reaction force corresponding to the rotation angle of the means.
When the rotation angle of the opening and closing valve is less than a predetermined value, the biasing means increases the rotation angle at the first ratio according to the rotation angle of the opening and closing valve, and generates a reaction force that increases according to the rotation angle. When the exhaust pressure increases and the turning angle of the opening / closing valve exceeds a predetermined value, the biasing means turns at a second ratio smaller than the first ratio, so that the urging means turns over the predetermined turning angle of the opening / closing valve. Since the reaction force increment can be reduced and the apparent spring constant decreases, the open / close valve opens smoothly to allow the exhaust with increased pressure and flow rate to pass, thereby suppressing the increase in the internal pressure of the silencer. In addition, it is possible to suppress an increase in exhaust loss in a high rotation range of the engine.
【００２１】また、第３の発明は、付勢手段を排気消音
装置の所定の外部に配設するとともに、カムを介して開
閉バルブを付勢するようにしたため、付勢手段は高温の
排気と直接接触することがなくなって、耐熱性、耐食性
を緩和することができる。According to the third aspect of the present invention, the urging means is disposed outside the exhaust muffler at a predetermined position and the opening / closing valve is urged via a cam. Direct contact is eliminated, and heat resistance and corrosion resistance can be reduced.
【００２２】また、第４の発明は、開閉バルブの回動角
が所定値を越えるとこの回動軸から開閉バルブが付勢手
段に加える排気圧の作用点までの距離を増大させて、排
気圧力のモーメントを増大し、回動角に応じて増大する
付勢手段の反力の増分値を相対的に減少させることで見
かけのバネ定数が低減され、開閉バルブは円滑に開弁し
て圧力及び流量の増大した排気を通過させて消音装置の
内圧の増大を抑制し、エンジンの高回転域における排気
損失の増大を抑制することができる。According to a fourth aspect of the present invention, when the rotation angle of the on-off valve exceeds a predetermined value, the distance from the rotation axis to the point of application of the exhaust pressure applied to the biasing means by the on-off valve is increased, and The apparent spring constant is reduced by increasing the moment of pressure and relatively decreasing the incremental value of the reaction force of the biasing means, which increases in accordance with the rotation angle, and the open / close valve opens smoothly to increase the pressure. In addition, it is possible to suppress the increase in the internal pressure of the silencer by passing the exhaust gas having the increased flow rate, thereby suppressing the increase in the exhaust loss in the high engine speed range.
【００２３】また、第５の発明は、第１及び第２摺接手
段によって開閉バルブの回動角に応じて開閉バルブが付
勢手段に加える排気圧力の作用点のモーメントを切り換
えるようにしたため、回動角が所定値以上では排気圧力
は第１の距離より大きい第２の距離で付勢手段に対抗
し、回動角に応じて増大する付勢手段の反力の増分値を
相対的に減少することができ、開閉バルブは円滑に開弁
して圧力及び流量の増大した排気を通過させることで消
音装置の内圧の増大を抑制し、エンジンの高回転域にお
ける排気損失の増大を抑制することができる。According to a fifth aspect of the present invention, the moment of the operating point of the exhaust pressure applied to the urging means by the on-off valve is switched by the first and second sliding contact means in accordance with the rotation angle of the on-off valve. When the rotation angle is equal to or larger than the predetermined value, the exhaust pressure opposes the urging means at a second distance larger than the first distance, and relatively increases the reaction force increment value of the urging means that increases according to the rotation angle. The on-off valve can be smoothly opened to suppress the increase in the internal pressure of the silencer by allowing the exhaust gas having the increased pressure and flow rate to pass, thereby suppressing the increase in the exhaust loss in the high engine speed range. be able to.
【００２４】また、第６の発明は、開閉バルブの回動角
の増大に応じて付勢手段の反力の増分値が低減されるた
め、開閉バルブは円滑に開弁して圧力及び流量の増大し
た排気を通過させて消音装置の内圧の増大を抑制するこ
とができ、エンジンの高回転域における排気損失の増大
を抑制し、排気圧力に応じて排気流路を切り換えてエン
ジンの全回転域での消音を確実に行いながら出力の低下
を抑制する。According to the sixth aspect of the present invention, since the incremental value of the reaction force of the urging means is reduced in accordance with the increase in the rotation angle of the on-off valve, the on-off valve is opened smoothly, and the pressure and the flow rate are reduced. The increased exhaust gas can be passed to suppress the increase in the internal pressure of the silencer, suppress the increase in exhaust loss in the high engine speed range, and switch the exhaust flow path according to the exhaust pressure to achieve the entire engine speed range. The output is suppressed while the noise is reliably suppressed.
【００２５】また、第７の発明は、開閉バルブの回動角
の増大に応じて付勢手段は開閉バルブの曲面に沿って徐
々に回動角の増分値が減少するため、付勢手段の反力の
増分値は開閉バルブの開弁角度の増大に伴って低減し、
開閉バルブは円滑に見かけのバネ定数を低減しながら開
弁し、圧力及び流量の増大した排気を通過させることで
消音装置の内圧の増大を抑制し、エンジンの高回転域に
おける排気損失の増大を抑制することができる。According to a seventh aspect of the present invention, the urging means gradually decreases the increment of the turning angle along the curved surface of the on-off valve in accordance with the increase of the turning angle of the on-off valve. The incremental value of the reaction force decreases as the opening angle of the on-off valve increases,
The on-off valve opens smoothly while reducing the apparent spring constant, and suppresses the increase in the internal pressure of the silencer by allowing the exhaust with increased pressure and flow rate to pass, thereby reducing the increase in exhaust loss at high engine speeds. Can be suppressed.
【００２６】[0026]
【実施例】以下、本発明の実施例を添付図面に基づいて
説明する。Embodiments of the present invention will be described below with reference to the accompanying drawings.
【００２７】図１、図２に示すように、マフラ１は前記
従来例と同様にほぼ長円形状の断面を備えており、マフ
ラ１の内周にはバッフル板６、７、８がマフラ１の横断
方向に配設され、これらバッフル板６、７、８によって
図１において右側より拡張室４、３、２及び共鳴室１８
１が順次隣合う位置でそれぞれ画成される。As shown in FIGS. 1 and 2, the muffler 1 has a substantially elliptical cross section as in the prior art, and baffle plates 6, 7, 8 are provided on the inner periphery of the muffler 1. 1, the expansion chambers 4, 3, 2 and the resonance chamber 18 are arranged from the right side in FIG.
1 are sequentially defined at adjacent positions.
【００２８】図示しないエンジンからの排気をマフラ１
へ導くインレットチューブ５は、拡張室３、４を順次貫
通した後に拡張室２に開口し、エンジンからの排気を拡
張室２へ導く。Exhaust from an engine (not shown) is
The inlet tube 5 that leads to the expansion chamber 2 is opened to the expansion chamber 2 after sequentially passing through the expansion chambers 3 and 4, and guides exhaust gas from the engine to the expansion chamber 2.
【００２９】拡張室２と拡張室３はバッフル板６を貫通
したパスチューブ９を介して連通しており、同様に拡張
室２と共鳴室１８はバッフル板８を貫通した首管１６、
１７を介して連通する。The expansion chamber 2 and the expansion chamber 3 communicate with each other via a pass tube 9 penetrating the baffle plate 6. Similarly, the expansion chamber 2 and the resonance chamber 18 communicate with the neck tube 16 penetrating the baffle plate 8,
The communication is made via a communication line 17.
【００３０】そして、拡張室３には外部と連通するテー
ルチューブ１０が開口し、このテールチューブ１０は拡
張室３から拡張室２、共鳴室１８を順次貫通した後にマ
フラ１の外部に突出するもので、エンジンの低回転域に
おける排気騒音の低減を重視する所定の径及び長さを備
える。A tail tube 10 communicating with the outside is opened in the expansion chamber 3, and this tail tube 10 projects from the expansion chamber 3 to the outside of the muffler 1 after passing through the expansion chamber 2 and the resonance chamber 18 in order. And a predetermined diameter and length that emphasize the reduction of exhaust noise in the low rotation range of the engine.
【００３１】拡張室３と隣合う位置でバッフル板７を介
して画成された拡張室４は、エンジンの高回転域におけ
る排気騒音の低減を重視する所定の容量を備え、この拡
張室４には外部と連通するテールチューブ１１が開口
し、このテールチューブ１１は上記テールチューブ１０
と平行してマフラ１の外部へ突出する。The expansion chamber 4 defined by a baffle plate 7 at a position adjacent to the expansion chamber 3 has a predetermined capacity that emphasizes reduction of exhaust noise in a high engine speed range. Opens a tail tube 11 communicating with the outside, and this tail tube 11
Project out of the muffler 1 in parallel.
【００３２】ここで、拡張室２、共鳴室１８を貫通する
区間のテールチューブ１０、１１の内周には多数の貫通
孔からなる多孔部１９が形成されるとともに、これら多
孔部１９を形成したテールチューブ１０、１１の外周に
は気流音を減衰するための吸音材２０がそれぞれ設けら
れ、さらに、この吸音材２０の外周を覆うように外筒２
１が形成されてテールチューブ１０、１１から拡張室２
及び共鳴室１８への排気の漏れを防止する。Here, a plurality of perforated portions 19 formed of a large number of through holes are formed on the inner periphery of the tail tubes 10 and 11 in a section penetrating the extension chamber 2 and the resonance chamber 18, and these perforated portions 19 are formed. A sound absorbing material 20 for attenuating the airflow noise is provided on the outer periphery of the tail tubes 10 and 11, respectively.
1 is formed to extend the expansion chamber 2 from the tail tubes 10 and 11.
In addition, leakage of exhaust gas to the resonance chamber 18 is prevented.
【００３３】一方、バッフル板７には拡張室３と拡張室
４とを連通する排気通路としての貫通孔１２がパスチュ
ーブ９と対峙する所定の位置に形成され、バッフル板７
の拡張室４側には貫通孔１２を開閉するバルブ１４が設
けられる。On the other hand, the baffle plate 7 is formed with a through hole 12 as an exhaust passage communicating the extension chamber 3 and the extension chamber 4 at a predetermined position facing the pass tube 9.
A valve 14 for opening and closing the through hole 12 is provided on the side of the expansion chamber 4.
【００３４】このバルブ１４は、図１、図２に示すよう
に、所定の位置に拡張室４側に開口するとともに拡張室
３側、すなわち、閉弁方向に向かってくぼんだ凹部１４
Ａを備えた板状部材で形成されるとともに、バッフル板
７に固設された軸１５を介してバルブ１４の基端がヒン
ジ結合され、バルブ１４は基端を軸に拡張室４側へ回動
自在に支持されて貫通孔１２が開口した弁座としてのバ
ッフル板７と接離可能となる。基端から凹部１４Ａまで
の区間が第１の摺接面を構成する一方、凹部１４Ａが第
２の摺接面を構成する。As shown in FIGS. 1 and 2, the valve 14 opens at a predetermined position on the side of the expansion chamber 4 and has a concave portion 14 which is recessed toward the expansion chamber 3, ie, in the valve closing direction.
A, and a base end of a valve 14 is hinged via a shaft 15 fixed to the baffle plate 7, and the valve 14 turns around the base end toward the expansion chamber 4. The baffle plate 7 as a valve seat, which is movably supported and has a through hole 12 opened, can come and go. The section from the base end to the recess 14A forms a first sliding contact surface, while the recess 14A forms a second sliding contact surface.
【００３５】そして、バルブ１４をバッフル板７へ向け
て付勢するリターンスプリング１３は、ほぼＬ字状に形
成されたブラケット３０の自由端側に基端１３Ａを固設
される。なお、このブラケット３０の基端はバルブ１４
の基端側に近接したバッフル板７に固設される一方、自
由端側を拡張室４内へ突出する。The return spring 13 for urging the valve 14 toward the baffle plate 7 has a base end 13A fixed to the free end side of a bracket 30 formed substantially in an L shape. The base end of the bracket 30 is connected to the valve 14.
Is fixed to the baffle plate 7 adjacent to the base end side, while the free end side protrudes into the expansion chamber 4.
【００３６】リターンスプリング１３は所定のバネ定数
を備えた板状部材を屈曲形成したもので、ブラケット３
０に固設された基端１３Ａからバルブ１４の中央部側へ
向けて屈曲した後、自由端１３Ｂでバルブ１４と摺接す
る。The return spring 13 is formed by bending a plate-like member having a predetermined spring constant.
After bending from the base end 13A fixed to 0 toward the center of the valve 14, the free end 13B comes into sliding contact with the valve 14.
【００３７】ここで、リターンスプリング１３の基端１
３Ａとバルブ１４の軸１５との間は所定の間隔に設定さ
れ、バルブ１４の回動角の増大に応じてリターンスプリ
ング１３は基端を軸に回動して反力、すなわち、閉弁方
向への力を増大させる。Here, the proximal end 1 of the return spring 13
3A and the shaft 15 of the valve 14 are set at a predetermined interval. As the rotation angle of the valve 14 increases, the return spring 13 rotates about the base end as a reaction force, that is, the valve closing direction. Increase the power to
【００３８】ここで、バルブ１４に形成した第２摺接面
としての凹部１４Ａは、図２に示すように、バルブ１４
が閉弁した状態、すなわち、バルブ１４がバッフル板７
に当接した位置において、リターンスプリング１３の自
由端１３Ｂが当接した位置から図中上方へ所定の間隔を
おいてバルブ１４の拡張室４側の面に対して所定の角度
で拡張室３側へ傾斜を開始する屈曲位置１４Ｂを備え、
凹部１４Ａはこの屈曲位置１４Ｂから拡張室３へ向けて
傾斜する。なお、凹部１４Ａはリターンスプリング１３
が出入り可能な所定の幅を備える。Here, as shown in FIG. 2, the recess 14A as the second sliding contact surface formed on the valve 14 is
Is closed, that is, the valve 14 is
At a predetermined distance from the position where the free end 13B of the return spring 13 is in contact with the expansion chamber 4 at a predetermined angle with respect to the surface of the valve 14 on the expansion chamber 4 side. With a bending position 14B to start tilting to
The concave portion 14A is inclined from the bending position 14B toward the expansion chamber 3. The recess 14A is provided with the return spring 13
Is provided with a predetermined width that allows access.
【００３９】以上のように構成され、次に作用について
説明する。The configuration is as described above. Next, the operation will be described.
【００４０】エンジンからの排気はインレットチューブ
５を介してまず拡張室２へ流入する。拡張室２へ流入し
た排気は首管１６、１７を介して連通した共鳴室１８で
騒音、すなわち、圧力波を減衰された後、パスチューブ
９を介してさらに騒音を減衰しながら拡張室３へ流入す
る。The exhaust gas from the engine first flows into the expansion chamber 2 via the inlet tube 5. The exhaust gas that has flowed into the expansion chamber 2 is attenuated by the resonance chamber 18 communicating via the neck pipes 16 and 17, that is, the pressure wave is attenuated, and then is further attenuated through the pass tube 9 to the expansion chamber 3. Inflow.
【００４１】エンジンの低回転域においては排気圧力が
低いためリターンスプリング１３の所定のバネ定数で付
勢されたバルブ１４は開弁せず、拡張室３の排気はテー
ルチューブ１０より外部へ排出される一方、テールチュ
ーブ１１からの排気の排出は行われない。Since the exhaust pressure is low in the low engine speed range, the valve 14 urged by the predetermined spring constant of the return spring 13 does not open, and the exhaust of the expansion chamber 3 is discharged to the outside from the tail tube 10. On the other hand, the exhaust from the tail tube 11 is not discharged.
【００４２】拡張室２、３及び共鳴室１８の容量がエン
ジンの低回転域に応じた所定の容量を備えているため、
エンジンの回転数に同期する排気の脈動成分が拡張室
２、３を順次通過する際に減衰されることで排気騒音を
低減することができ、さらに、テールチューブ１０の多
孔部１９及び吸音材２０でも排気騒音の減衰が行われ
る。Since the capacities of the expansion chambers 2 and 3 and the resonance chamber 18 have predetermined capacities corresponding to the low engine speed range,
Exhaust noise can be reduced by attenuating the pulsating component of exhaust synchronized with the engine speed when sequentially passing through the expansion chambers 2 and 3, and furthermore, the porous portion 19 and the sound absorbing material 20 of the tail tube 10 can be reduced. However, the exhaust noise is attenuated.
【００４３】一方、エンジンの高回転域になるとインレ
ットチューブ５から流入する排気圧力が増大し、拡張室
３の内圧が所定値を越えるとリターンスプリング１３に
抗してバルブ１４が開弁する。On the other hand, when the engine speed becomes high, the exhaust pressure flowing from the inlet tube 5 increases, and when the internal pressure of the expansion chamber 3 exceeds a predetermined value, the valve 14 opens against the return spring 13.
【００４４】マフラ１へ流入した排気は上記低回転域と
同様にして拡張室２、３を介してテールチューブ１０か
ら外部へ排出されるとともに、拡張室４を介してテール
チューブ１１からも排出され、マフラ１から排出される
排気の管路面積はテールチューブ１０の断面積にテール
チューブ１１の断面積が加わるため、排気管路の径を拡
大することと等価となって排気流量の増大する高回転域
における排気損失を低減してエンジン出力の低下を抑制
するとともに、排気の気流騒音を低減することができ
る。The exhaust gas flowing into the muffler 1 is discharged from the tail tube 10 through the expansion chambers 2 and 3 to the outside in the same manner as in the low rotation speed region, and is also discharged from the tail tube 11 through the expansion chamber 4. Since the cross-sectional area of the tail tube 10 is added to the cross-sectional area of the tail tube 10, the pipe area of the exhaust gas discharged from the muffler 1 is equivalent to enlarging the diameter of the exhaust pipe, and the exhaust flow rate increases. It is possible to reduce the exhaust loss in the rotation range, suppress the engine output from lowering, and reduce the exhaust airflow noise.
【００４５】ここで、バルブ１４の開弁は図３に示すよ
うに、エンジンの回転数の増大に伴って拡張室３の内圧
が上昇すると、この内圧に抗してバルブ１４を閉弁して
いたリターンスプリング１３の自由端１３Ｂは、バルブ
１４の基端側から表面と摺接しながら凹部１４Ａへ向け
て変位し、バルブ１４の拡張室４側へ向けた回動を許容
する。As shown in FIG. 3, when the internal pressure of the expansion chamber 3 increases as the engine speed increases, the valve 14 is closed against the internal pressure. The free end 13B of the return spring 13 is displaced toward the recess 14A while slidingly contacting the surface from the base end side of the valve 14 to allow the valve 14 to rotate toward the expansion chamber 4 side.
【００４６】バルブ１４は軸１５を中心に回動する一
方、リターンスプリング１３は軸１５から所定距離だけ
離れた基端１３Ａを軸に回動するため、リターンスプリ
ング１３の自由端１３Ｂは凹部１４Ａへ向けてバルブ１
４の表面上を摺接しながら変位する。The valve 14 rotates about the shaft 15 while the return spring 13 rotates about the base end 13A that is a predetermined distance away from the shaft 15, so that the free end 13B of the return spring 13 goes into the recess 14A. Valve 1 for
4 while sliding on the surface.
【００４７】まず、バルブ１４が閉弁位置から図中θ1
だけ回動すると、バルブ１４の閉弁位置では図中Ｐ1の
バルブ１４の表面上にあった自由端１３Ｂは、図中Ｐ2
の屈曲位置まで変位して、リターンスプリング１３はα
1だけ回動角を増大する。First, the valve 14 is moved from the closed position to θ 1 in FIG.
In the closed position of the valve 14, the free end 13B on the surface of the valve 14 at P 1 in the figure is moved to P 2 in the figure.
And the return spring 13 is moved to the bending position
Increase the rotation angle by one .
【００４８】バルブ１４が閉弁位置からθ1だけ回動す
る区間では、リターンスプリング１３の自由端１３Ｂが
Ｐ1からＰ2へ移動して、バルブ１４の回動角θ1に対応
してリターンスプリング１３は第１の比率で回動角をα
1だけ増大し、リターンスプリング１３はバネ定数と回
動角度に応じた反力をバルブ１４の閉弁方向へ発生す
る。In a section in which the valve 14 rotates from the valve closing position by θ 1 , the free end 13B of the return spring 13 moves from P 1 to P 2 and returns in accordance with the rotation angle θ 1 of the valve 14. The spring 13 has a rotation angle α at a first ratio.
The return spring 13 generates a reaction force corresponding to the spring constant and the rotation angle in the valve closing direction of the valve 14.
【００４９】さらに拡張室３の内圧が増大すると、バル
ブ１４はリターンスプリング１３の反力に抗して回動す
るが、リターンスプリング１３は屈曲位置１４Ｂ、すな
わち、図中Ｐ2以降は自由端１３Ｂが凹部１４Ａに沿っ
て摺接し、自由端１３Ｂは凹部１４Ａの底部へ向かって
変位するため、軸１５から自由端１３Ｂの摺接位置まで
の距離の増分値は減少するとともに、リターンスプリン
グ１３の回動角の増分は凹部１４Ａの傾斜角に応じて低
減される。[0049] Further the internal pressure of the expansion chamber 3 is increased, the valve 14 is rotated against the reaction force of the return spring 13 but the return spring 13 bending position 14B, that is, in the drawing P 2 after the free end 13B Slides along the recess 14A, and the free end 13B is displaced toward the bottom of the recess 14A. Therefore, the incremental value of the distance from the shaft 15 to the slide contact position of the free end 13B decreases, and the return spring 13 rotates. The increment of the movement angle is reduced according to the inclination angle of the recess 14A.
【００５０】すなわち、図中θ2（ただし、θ2＞θ1）
までバルブ１４が回動すると、自由端１３Ｂは凹部１４
Ａに沿ったＰ3まで変位してリターンスプリング１３の
回動角は第２の比率で増大した角度α2となる。仮に自
由端１３Ｂがバルブ１４の平面上を変位した位置がＰ3'
とすると、自由端１３ＢがＰ3の位置ではリターンスプ
リング１３の回動角がΔαだけ低減されてΔαに相当す
るバネ反力の増分を低減することができ、リターンスプ
リング１３の見かけのバネ定数は低減する。That is, in the figure, θ 2 (where θ 2 > θ 1 )
When the valve 14 rotates, the free end 13B is
Rotation angle of the return spring 13 is displaced to P 3 along the A is an angle alpha 2 which is increased by the second ratio. The position where the free end 13B is displaced on the plane of the valve 14 is P 3 ′.
When the free end 13B are able to rotation angle of the return spring 13 at the position of the P 3 reduces an increment of spring reaction force corresponding to the is reduced by [Delta] [alpha] [Delta] [alpha], the spring constant of the apparent return spring 13 Reduce.
【００５１】したがって、自由端１３Ｂがバルブ１４の
屈曲位置１４Ｂを通過するまでの区間Ｐ1〜Ｐ2ではバル
ブ１４の回動角に応じてリターンスプリング１３の反力
は第１の比率で増大するが、自由端１３Ｂが凹部１４Ａ
と摺接する位置Ｐ2以降の区間ではリターンスプリング
１３の反力は第２の比率で増大し、反力の増分値はＰ2
までの区間に比して低減されるため、バルブ１４を開弁
して拡張室４へ流入する排気は、バルブ１４が所定の回
転角度θ1以上になればリターンスプリング１３の反力
の増分値が低減されるために円滑に通過することがで
き、マフラ１内の圧力の増大を抑制し、前記従来例に比
して背圧の増大、すなわち、排気損失の増大を抑制して
エンジンの高回転域における出力低下を抑制して効率良
くテールチューブ１１からの排出を行うことが可能とな
る。Therefore, in the section P 1 to P 2 until the free end 13 B passes the bending position 14 B of the valve 14, the reaction force of the return spring 13 increases at the first ratio according to the rotation angle of the valve 14. However, the free end 13B is the recess 14A.
And increase in the reaction force to the second ratio of the return spring 13 in sliding contact position P 2 and subsequent sections, increment of reaction force P 2
The exhaust flowing into the expansion chamber 4 with the valve 14 opened is reduced when the valve 14 reaches a predetermined rotation angle θ 1 or more, and the reaction force increment value of the return spring 13 As a result, the passage through the muffler 1 can be suppressed smoothly, the increase in the pressure inside the muffler 1 can be suppressed, and the increase in the back pressure, that is, the increase in the exhaust loss can be suppressed as compared with the conventional example. The output from the tail tube 11 can be efficiently discharged by suppressing the output reduction in the rotation range.
【００５２】なお、拡張室４は高回転域に応じた所定の
容積を備えているため、拡張室３から流入した排気に含
まれる高周波成分の騒音を減衰することができ、また、
テールチューブ１１の多孔部１９、吸音材２０も上記と
同様に騒音及び気流音を減衰し、高回転域においても排
気騒音の低減を確実に行うことができるのである。Since the expansion chamber 4 has a predetermined volume corresponding to the high rotation range, it is possible to attenuate high frequency component noise contained in exhaust gas flowing from the expansion chamber 3.
The perforated portion 19 and the sound absorbing material 20 of the tail tube 11 also attenuate the noise and the airflow noise in the same manner as described above, so that the exhaust noise can be reliably reduced even in a high rotation speed region.
【００５３】このようにして、エンジンの低回転域の消
音を主に行う拡張室２、３及び共鳴室１８と、エンジン
の高回転域回転の消音を行う拡張室４とを設け、排気圧
力に応じて開弁するバルブ１４を拡張室３、４の間に介
装するとともに、バルブ１４を付勢するリターンスプリ
ング１３の見かけのバネ定数を低減する凹部１４Ａを設
けたため、前記従来例のように排気圧力の増大に比例し
てリターンスプリング１３の反力が増大するのを抑制す
ることができ、エンジンの低回転域ではバルブ１４を確
実に閉弁可能なバネ定数をリターンスプリング１３に設
定しても、バルブ１４が所定の回動角以上となるとリタ
ーンスプリング１３の反力の増分値は低減されるため、
エンジンの運転状態に応じて排気流路を確実に切り換え
ながらも高回転域では背圧の増大を抑制し、前記従来例
に比して高回転域で出力を向上させなることが可能とな
り、エンジンの全回転域における出力を確保しながら確
実に排気騒音を低減することが可能となり、特別な制御
手段を必要とすることなく装置の構成を簡素にして製造
コストの増大を抑制することができるのである。In this way, the expansion chambers 2, 3 and the resonance chamber 18, which mainly perform noise reduction in the low rotation range of the engine, and the expansion chamber 4, which performs noise reduction in the high rotation range of the engine, are provided. A valve 14 that opens correspondingly is interposed between the expansion chambers 3 and 4, and a concave portion 14A that reduces the apparent spring constant of the return spring 13 that biases the valve 14 is provided. It is possible to suppress an increase in the reaction force of the return spring 13 in proportion to the increase in the exhaust pressure, and set the return spring 13 to a spring constant that allows the valve 14 to be reliably closed in the low engine speed range. However, when the valve 14 has a predetermined rotation angle or more, the incremental value of the reaction force of the return spring 13 is reduced.
While reliably switching the exhaust flow path in accordance with the operating state of the engine, it is possible to suppress an increase in the back pressure in the high rotation range and improve the output in the high rotation range as compared with the conventional example. It is possible to reliably reduce exhaust noise while ensuring output in the entire rotation range of the device, and it is possible to simplify the configuration of the device without requiring special control means and suppress an increase in manufacturing cost. is there.
【００５４】図４、図５は第２の実施例を示し、前記第
１実施例における板状のリターンスプリング１３をコイ
ル状のリターンスプリング４０に置き換えると共に、第
１実施例の凹部１４Ａの傾斜角度をθaに増大した凹部
１４Ａ′としたもので、その他の構成は前記第１実施例
と同様である。FIGS. 4 and 5 show a second embodiment, in which the plate-shaped return spring 13 in the first embodiment is replaced by a coil-shaped return spring 40, and the inclination angle of the recess 14A of the first embodiment is changed. Is reduced to θa, and the other configuration is the same as that of the first embodiment.
【００５５】リターンスプリング４０はバルブ１４′を
軸支する軸１５から所定の距離だけ離れるとともにほぼ
平行して配設された軸４３に巻き付けられ、基端４０Ａ
をバッフル板７に当接する一方、自由端４０Ｂを上記第
１実施例と同様にバルブ１４′と摺接する。なお、軸１
５、４３は、それぞれ拡張室４側のバッフル板７に固設
された軸受３２、３２で両端を支持される。The return spring 40 is separated from the shaft 15 supporting the valve 14 'by a predetermined distance and is wound around a shaft 43 disposed substantially parallel to the shaft 15 and has a base end 40A.
Is in contact with the baffle plate 7, while the free end 40B is in sliding contact with the valve 14 'as in the first embodiment. In addition, axis 1
The ends 5 and 43 are supported at both ends by bearings 32 fixed to the baffle plate 7 on the expansion chamber 4 side.
【００５６】リターンスプリング４０の自由端４０Ｂ側
には拡張室４の内部へ向けて屈曲した屈曲部４０Ｃを形
成して、バルブ１４が回動した際に屈曲位置１４Ｂ′が
自由端４０Ｂ以外のリターンスプリング４０に干渉する
のを防いでいる。A bent portion 40C bent toward the inside of the expansion chamber 4 is formed on the free end 40B side of the return spring 40, and when the valve 14 is turned, the bent position 14B 'is set to a return position other than the free end 40B. Interference with the spring 40 is prevented.
【００５７】図６に示すように、エンジンが高回転域と
なって拡張室３側の圧力が増大すると、自由端４０Ｂが
屈曲位置１４Ｂ′に達するまでの区間、図中Ｐ1〜Ｐ2で
はリターンスプリング４０の反力は前記と同様に第１の
比率で増大した回動角に比例するが、自由端４０Ｂが凹
部１４Ａ′と摺接するＰ2以降の区間ではリターンスプ
リング４０の反力の増分値は前記と同様に第２の比率で
増大する回動角に比例して低減され、拡張室３の内圧の
上昇を抑制して排気損失を低減することができるのであ
る。[0057] As shown in FIG. 6, the engine is the pressure of the high rotation region and is in extension chamber 3 side is increased, the interval up to the free end 40B reaches a bending position 14B ', in figure P 1 to P 2 Although the reaction force of the return spring 40 is proportional to the rotation angle increased by the first ratio in the same manner as described above, the increment of the reaction force of the return spring 40 is P 2 and subsequent sections the free end 40B is in sliding contact with the concave portion 14A ' As described above, the value is reduced in proportion to the rotation angle that increases at the second ratio, so that an increase in the internal pressure of the expansion chamber 3 can be suppressed and exhaust loss can be reduced.
【００５８】ここで、凹部１４Ａ′の傾斜角度θａを前
記第１実施例の凹部１４Ａに比して増大したため、位置
Ｐ2以降のリターンスプリング４０の反力の増分値をさ
らに低減することができ、前記第１実施例に比して排気
圧力の増大をさらに抑制することができ、エンジンの高
回転域での排気損失をさらに低減して出力を向上させる
ことが可能となり、低回転域では確実にバルブ１４′を
閉弁する付勢力を確保することができる。Here, since the inclination angle θa of the concave portion 14A ′ is increased compared to the concave portion 14A of the first embodiment, the incremental value of the reaction force of the return spring 40 after the position P 2 can be further reduced. As compared with the first embodiment, it is possible to further suppress the increase in the exhaust pressure, to further reduce the exhaust loss in the high rotation range of the engine and to improve the output, and to ensure the improvement in the low rotation range. Therefore, the urging force for closing the valve 14 'can be secured.
【００５９】また、バッフル板７とバルブ１４′との間
に緩衝部材３１を介装することで、バルブ１４′の開閉
を円滑に行うと共に、低回転域での排気のシール性を向
上することができる。Further, by interposing the buffer member 31 between the baffle plate 7 and the valve 14 ', the valve 14' can be smoothly opened and closed, and the sealing performance of the exhaust in a low rotation range can be improved. Can be.
【００６０】図７は第３の実施例を示し、前記第２実施
例における凹部１４Ａ′を曲面で構成した凹部１４Ａ”
としたもので、その他の構成は前記第２実施例と同様で
ある。FIG. 7 shows a third embodiment, in which the concave portion 14A 'in the second embodiment is formed by a curved surface.
The other configuration is the same as that of the second embodiment.
【００６１】凹部１４Ａ”はバルブ１４′の平面上の屈
曲位置１４Ｂ′から図中上方へ向かうに従って拡張室３
側へ向けた傾斜角度を徐々に増大する曲面としたため、
バルブ１４′の回動角度の増大に伴ってリターンスプリ
ング４０の回動角、すなわち、反力の増分値は漸次減少
され、上記と同様にエンジンの低回転域ではバルブ１４
を確実に閉弁して高回転域用の排気流路への漏れを防ぎ
ながら、高回転域における排気圧力の増大を効果的に抑
制して出力の向上をさらに推進することができ、凹部１
４Ａ′の曲面に応じて滑らかに見かけのバネ定数を変更
してバルブ１４′の開閉を円滑に行うことができる。The recess 14A "extends from the bending position 14B 'on the plane of the valve 14' to the expansion chamber 3 in the upward direction in the figure.
Because the angle of inclination toward the side is a curved surface that gradually increases,
As the rotation angle of the valve 14 'increases, the rotation angle of the return spring 40, that is, the incremental value of the reaction force, gradually decreases.
Is reliably closed to prevent leakage to the exhaust passage for the high rotation range, and increase in the exhaust pressure in the high rotation range is effectively suppressed to further promote the output improvement.
The valve 14 'can be smoothly opened and closed by changing the apparent spring constant smoothly in accordance with the curved surface of 4A'.
【００６２】図８は第４の実施例を示し、拡張室３、４
との間の貫通孔１２を開閉するバルブ２４の拡張室４側
に第１摺接手段としての凸部２４Ａを形成し、このバル
ブ２４をバッフル板７へ向けて付勢する板バネ４１を拡
張室４の内部の所定の位置に配設したもので、その他の
構成は前記第１実施例と同様である。FIG. 8 shows a fourth embodiment, in which the expansion chambers 3, 4
A convex portion 24A as a first sliding contact means is formed on the side of the expansion chamber 4 of the valve 24 that opens and closes the through hole 12 between the valve spring 24 and the leaf spring 41 that urges the valve 24 toward the baffle plate 7 is expanded. It is arranged at a predetermined position inside the chamber 4, and the other configuration is the same as that of the first embodiment.
【００６３】バルブ２４は基端を軸１５で支持されて拡
張室４側へ回動可能となってバッフル板７と接離し、貫
通孔１２を挟んで軸１５からＬ1だけ離れた所定の位置
にバルブ２４の自由端２４Ｂが形成され、軸１５からＬ
2の位置には凸部２４Ａが拡張室４の内部へ向けて突設
される。The valve 24 has its base end supported by the shaft 15 and is rotatable toward the expansion chamber 4 so as to come into contact with and separate from the baffle plate 7 and to be separated from the shaft 15 by a distance L 1 with the through hole 12 therebetween. The free end 24B of the valve 24 is formed at
At the position 2, a protrusion 24 </ b > A protrudes toward the inside of the expansion chamber 4.
【００６４】そして、所定のバネ定数を備えた板バネ４
１は回動軸４１Ａを軸１５側に配設するとともに、バル
ブ２４の閉弁位置において、板バネ４１は基端４１Ａと
自由端４１Ｂとの間でバルブ２４の凸部２４Ａと摺接
し、板バネ４１はバルブ２４を付勢する。The leaf spring 4 having a predetermined spring constant
Reference numeral 1 designates a rotary shaft 41A disposed on the shaft 15 side, and at the valve closing position of the valve 24, the leaf spring 41 slides on the convex portion 24A of the valve 24 between the base end 41A and the free end 41B. Spring 41 biases valve 24.
【００６５】拡張室３側の排気圧力が増大すると、図９
に示すように、バルブ２４は板バネ４１に抗して回動を
開始し、図中θ1の位置では自由端２４Ｂが板バネ４１
の自由端４１Ｂ側と当接して、バルブ２４を付勢する板
バネ４１の作用点は凸部２４Ａから第２摺接手段として
の自由端２４Ｂへ移行する。When the exhaust pressure on the side of the expansion chamber 3 increases, FIG.
As shown in, the valve 24 is a plate starts rotating against the spring 41, the free end 24B leaf spring 41 in the position of figure theta 1
The point of action of the leaf spring 41 that abuts on the free end 41B side of the valve and biases the valve 24 shifts from the convex portion 24A to the free end 24B as the second sliding contact means.
【００６６】図１０に示すように、さらにバルブ２４が
回動して角度θ2（θ2＞θ1）となると、バルブ２４に
加わる排気圧力の作用点は軸１５からＬ1の距離の自由
端２４Ｂに移行するため、エンジンの低回転域では図中
Ｌ2（Ｌ1＞Ｌ2）の作用点で所定のバネ定数に応じて確
実にバルブ２４を閉弁する一方、バルブ２４が所定の角
度θ1以上開弁した後は作用点をＬ1に移行することで排
気圧力のモーメントを増大し、板バネ４１の反力の増分
値を相対的に低減することで上記と同様に排気圧力の増
大を抑制して高回転域における出力の低下を抑制する一
方、低回転域での閉弁を確実に行うバネ定数に設定でき
るのである。As shown in FIG. 10, when the valve 24 further rotates and reaches the angle θ 2 (θ 2 > θ 1 ), the point of application of the exhaust pressure applied to the valve 24 is free from the axis 15 at a distance of L 1. In order to shift to the end 24B, the valve 24 is reliably closed at a point of application of L 2 (L 1 > L 2 ) in the figure according to a predetermined spring constant in a low rotation range of the engine, while the valve 24 is in a predetermined position. After opening the valve by an angle θ 1 or more, the operating point is shifted to L 1 to increase the moment of the exhaust pressure, and the incremental value of the reaction force of the leaf spring 41 is relatively reduced to thereby reduce the exhaust pressure in the same manner as described above. While suppressing the increase in the output and suppressing the decrease in output in the high rotation range, it is possible to set the spring constant to surely close the valve in the low rotation range.
【００６７】図１１は第５の実施例を示し、前記第１実
施例に示したリターンスプリング１３をマフラ１の外部
に配設したリターンスプリング１３′に置き換えるとと
もに、バルブ１４に形成した凹部１４Ａをカム６０に置
き換えたものである。FIG. 11 shows a fifth embodiment, in which the return spring 13 shown in the first embodiment is replaced by a return spring 13 'disposed outside the muffler 1, and a recess 14A formed in the valve 14 is This is replaced with a cam 60.
【００６８】バルブ１４′は凹部１４Ａを廃止して平板
状に形成されて前記第１実施例と同様に軸１５を介して
回動自由に支持される。そして、マフラ１の外周の所定
の位置に固設されたケース５１には軸５０が軸支され、
マフラ１に形成した貫通孔５２を介して拡張室４の内周
に突出するとともに、軸５０の下端が軸１５の上端と結
合する。The valve 14 'is formed in a flat plate shape without the concave portion 14A, and is rotatably supported via the shaft 15 as in the first embodiment. A shaft 50 is supported on a case 51 fixed at a predetermined position on the outer periphery of the muffler 1.
The lower end of the shaft 50 is connected to the upper end of the shaft 15 while projecting through the through hole 52 formed in the muffler 1 to the inner periphery of the expansion chamber 4.
【００６９】ケース５１の内周の軸５０にはカム６０が
同軸的に結合され、さらにカム６０を付勢する板状のリ
ターンスプリング１３′は基端１３Ａ′側をケース５１
の内部に固設され、自由端１３Ｂ′をカム６０に摺接す
る。[0069] Cam 60 is axially 50 of the inner periphery of the case 51 is coaxially coupled, plate-like Li further urges the cam 60
The turn spring 13 ′ is provided on the base 51
And the free end 13B 'slides on the cam 60.
【００７０】カム６０は図１２において、基端６０Ｃ側
を軸５０に結合され、リターンスプリング１３′と対峙
する所定の位置に凸部６０Ａを形成する一方、凸部６０
Ａの背面６０はほぼ平板状に形成される。In FIG. 12, the cam 60 is connected to the shaft 50 at the base end 60C side, and forms a convex portion 60A at a predetermined position facing the return spring 13 '.
The back surface 60 of A is formed in a substantially flat plate shape.
【００７１】リターンスプリング１３′と対峙するカム
６０は、基端６０Ｃから所定の距離だけ離れた凸部６０
Ａまで徐々に肉厚を増大する第１の摺接面を形成する一
方、凸部６０Ａから自由端６０Ｂに向けて徐々に肉厚を
減少する第２の摺接面を形成して、凸部６０Ａはリター
ンスプリング１３′側に向いた頂部となる。The cam 60 facing the return spring 13 'is provided with a convex portion 60 which is separated from the base end 60C by a predetermined distance.
A, while forming a first sliding contact surface whose thickness gradually increases up to A, a second sliding contact surface whose thickness gradually decreases from the convex portion 60A toward the free end 60B is formed. 60A is the top facing the return spring 13 '.
【００７２】図１２において、矢印方向がバルブ１４′
の開弁方向を示し、リターンスプリング１３′の自由端
１３Ｂ′が凸部６０Ａより基端６０Ｃ側の位置で摺接す
る位置がバルブ１４′の閉弁位置となる。In FIG. 12, the direction of the arrow is the valve 14 '.
The position where the free end 13B 'of the return spring 13' slides on the base end 60C side of the convex portion 60A is the valve closing position of the valve 14 '.
【００７３】エンジンが高回転域となって排気圧力が増
大すると、バルブ１４′はリターンスプリング１３′に
抗して図１２においてカム６０を反時計回りに回動し、
リターンスプリング１３′の自由端１３Ｂ′は基端６０
Ｃ側から凸部６０Ａに向けて変位して、所定のバネ定数
に応じて反力を増大させる。When the engine is in a high rotation range and the exhaust pressure increases, the valve 14 'rotates the cam 60 counterclockwise in FIG. 12 against the return spring 13'.
The free end 13B 'of the return spring 13' is
It is displaced from the C side toward the convex portion 60A to increase the reaction force according to a predetermined spring constant.
【００７４】さらにバルブ１４′が回動して自由端１３
Ｂ′が凸部６０Ａを通過するとカム６０は肉厚が減少す
る方向に傾斜するためリターンスプリング１３′の反力
の増分値は上記と同様に低減され、高回転域における排
気損失を低減して出力の低下を抑制することができ、バ
ルブ１４′を付勢するリターンスプリング１３′をマフ
ラ１の外部に配設することによって、リターンスプリン
グ１３′に課せられる耐熱性、耐食性等を緩和すること
が可能となって、信頼性を向上させることができるので
ある。Further, the valve 14 ′ is rotated to move the free end 13.
When B 'passes through the convex portion 60A, the cam 60 is inclined in the direction of decreasing the thickness, so that the increment of the reaction force of the return spring 13' is reduced in the same manner as described above, and the exhaust loss in the high rotation region is reduced. A decrease in output can be suppressed, and the heat resistance, corrosion resistance, and the like imposed on the return spring 13 'can be reduced by disposing a return spring 13' for urging the valve 14 'outside the muffler 1. As a result, reliability can be improved.
【００７５】[0075]
【発明の効果】以上説明したように第１の発明は、エン
ジンの運転状態に応じて排気流路を切り換えて、低回転
域と高回転域での排気騒音を減衰、吸収するようにした
自動車用排気消音装置において、排気圧力に応動して排
気流路を切り換える開閉バルブと、排気圧力に対抗して
前記開閉バルブを閉弁方向に付勢する手段と、前記開閉
バルブの回動角が所定の値を越えると前記付勢手段の反
力の増分を減少するバネ定数変更手段とを備え、エンジ
ンの低回転域で確実に閉弁可能なバネ定数を付勢手段に
設定しても、エンジンの高回転域における排気圧力の増
大を抑制することができ、前記従来例のようなエンジン
の高回転域における出力の低下を抑制することが可能と
なり、エンジンの全回転域で消音性能を満足しながら排
気損失の増大を抑制することができる。As described above, the first aspect of the present invention is an automobile in which an exhaust passage is switched in accordance with an operating state of an engine to attenuate and absorb exhaust noise in a low rotation speed range and a high rotation speed range. An opening / closing valve for switching an exhaust flow path in response to exhaust pressure, means for urging the opening / closing valve in a valve closing direction against exhaust pressure, and a rotation angle of the opening / closing valve being predetermined. A spring constant changing means for reducing the increment of the reaction force of the urging means when the value exceeds the value of the urging means. It is possible to suppress an increase in the exhaust pressure in the high speed range of the engine, to suppress a decrease in output in the high speed range of the engine as in the conventional example, and to satisfy the noise reduction performance in the entire speed range of the engine. While suppressing increase in exhaust loss It can be.
【００７６】また、第２の発明は、前記付勢手段は基端
を前記開閉バルブの回動軸から所定の位置に配設される
一方、自由端で前記開閉バルブに摺接し、付勢手段が摺
接する開閉バルブにはバネ定数変更手段として、開閉バ
ルブの回動角が所定値以下ではこの回動角に応じて基端
を軸に回動する付勢手段の回動角を第１の比率で増大さ
せる第１の摺接面と、開閉バルブの回動角が所定値を越
えると前記第１の比率よりも小さい第２の比率で回動角
に応じて基端を軸に回動する付勢手段の回動角を増大さ
せる第２の摺接面とをそれぞれ形成し、所定値を越える
開閉バルブの回動角では付勢手段の回動角の増分を低減
することで反力の増分値を低減でき、エンジンの低回転
域で確実に閉弁可能なバネ定数を付勢手段に設定して
も、エンジンの高回転域における排気圧力の増大を抑制
することができ、前記従来例のようなエンジンの高回転
域における出力の低下を抑制することが可能となり、特
別な制御手段を必要としないため、構成を簡易にして製
造コストの増大を抑制することができる。According to a second aspect of the present invention, the urging means has a base end disposed at a predetermined position from a rotation axis of the opening / closing valve, and has a free end slidingly contacting the opening / closing valve. When the turning angle of the on-off valve is equal to or less than a predetermined value, the turning angle of the urging means that turns around the base end in accordance with this turning angle is set to a first constant. When the rotation angle of the first sliding contact surface, which is increased by a ratio, and the rotation angle of the opening / closing valve exceeds a predetermined value, the rotation is performed around the base end in accordance with the rotation angle at a second ratio smaller than the first ratio. And a second sliding contact surface for increasing the rotation angle of the urging means, and reducing the increment of the rotation angle of the urging means when the opening angle of the opening and closing valve exceeds a predetermined value. Can be reduced, and even if the spring constant is set in the biasing means that can be reliably closed in the low engine speed range, the It is possible to suppress an increase in the exhaust pressure in the engine region, to suppress a decrease in the output in the high engine speed region of the engine as in the conventional example, and to eliminate the need for special control means. Thus, an increase in manufacturing cost can be suppressed.
【００７７】また、第３の発明は、前記開閉バルブの回
動軸は排気消音装置の所定の外部に配設されたカムと同
期的に回動可能に形成され、前記付勢手段は同じく所定
の外部に配設されるとともに、基端を前記カムの回動軸
から所定の位置に配設される一方、自由端で前記カムに
摺接し、バネ定数変更手段はこのカムに形成されて開閉
バルブの回動角が所定値以下では開閉バルブの回動角の
増大に応じて基端を軸に回動する付勢手段の回動角を第
１の比率で増大させる第１の摺接面と、開閉バルブの回
動角が所定値を越えると前記第１の比率よりも小さい第
２の比率で付勢手段の回動角を第２の比率で増大させる
第２の摺接面とをそれぞれ形成し、付勢手段及びカムは
直接高温の排気と接触することがなくなって、耐熱性、
耐食性を緩和することで信頼性を向上させることが可能
となる。According to a third aspect of the present invention, the rotating shaft of the opening / closing valve is formed so as to be rotatable synchronously with a cam disposed outside a predetermined portion of the exhaust silencer, and the biasing means is also provided with a predetermined And the base end is disposed at a predetermined position from the rotation axis of the cam, while the free end slides on the cam, and the spring constant changing means is formed on the cam to open and close. When the rotation angle of the valve is equal to or less than a predetermined value, a first sliding contact surface that increases the rotation angle of the urging means that rotates about the base end at a first ratio in accordance with an increase in the rotation angle of the opening / closing valve. And a second sliding contact surface that increases the rotation angle of the biasing means at a second ratio at a second ratio smaller than the first ratio when the rotation angle of the on-off valve exceeds a predetermined value. Each formed, the biasing means and the cam do not directly contact the high-temperature exhaust, heat resistance,
The reliability can be improved by relaxing the corrosion resistance.
【００７８】また、第４の発明は、前記バネ定数変更手
段は、開閉バルブの回動軸と開閉バルブが付勢手段へ加
える排気圧力の作用点との距離を増大させて相対的に付
勢手段の反力の増分を減少させ、開閉バルブの回動角が
所定値を越えると付勢手段に対抗する排気圧力のモーメ
ントを増大することで付勢手段の反力の増分値を相対的
に減少し、エンジンの高回転域における排気圧力の増大
を抑制することができ、前記従来例のようなエンジンの
高回転域における出力の低下を抑制することが可能とな
り、特別な制御手段を必要としないため、構成を簡易に
して製造コストの増大を抑制することができる。According to a fourth aspect of the present invention, the spring constant changing means increases the distance between the rotation axis of the opening / closing valve and the point of application of the exhaust pressure applied to the urging means by the opening / closing valve. When the rotation angle of the opening and closing valve exceeds a predetermined value, the moment of the exhaust pressure opposing the urging means is increased, thereby increasing the reaction force of the urging means relatively. It is possible to suppress the increase in the exhaust pressure in the high rotation range of the engine, and to suppress the decrease in the output in the high rotation range of the engine as in the conventional example, which requires special control means. Therefore, it is possible to simplify the configuration and suppress an increase in manufacturing cost.
【００７９】また、第５の発明は、前記付勢手段は基端
を前記開閉バルブの回動軸から所定の位置に配設される
一方、自由端で前記開閉バルブに摺接し、付勢手段が摺
接する開閉バルブにはバネ定数変更手段として、開閉バ
ルブの回動角が所定値以下では回動軸から第１の距離で
前記付勢手段と摺接する第１の摺接手段と、開閉バルブ
の回動角が所定値を越えると開閉バルブの回動軸から前
記第１の距離よりも大きい第２の距離で付勢手段と摺接
する第２の摺接手段とをそれぞれ形成し、第１及び第２
摺接手段で排気圧力の作用点を切り換えることで排気圧
力の作用点のモーメントを増減することができ、第２摺
接手段では第１摺接手段よりも排気圧力のモーメントが
増大して相対的に付勢手段の反力の増分値を低減でき、
エンジンの高回転域における排気圧力の増大を抑制する
ことができ、前記従来例のようなエンジンの高回転域に
おける出力の低下を抑制することが可能となり、特別な
制御手段を必要としないため、構成を簡易にして製造コ
ストの増大を抑制することができる。According to a fifth aspect of the present invention, the urging means has a base end disposed at a predetermined position from a rotation axis of the opening / closing valve, and has a free end slidingly contacting the opening / closing valve. A first sliding contact means for slidingly contacting the urging means at a first distance from the rotation axis when the rotation angle of the opening and closing valve is equal to or less than a predetermined value; When the rotation angle exceeds a predetermined value, second sliding contact means for slidingly contacting the urging means at a second distance greater than the first distance from the rotation axis of the opening / closing valve are formed, respectively. And the second
By switching the point of action of the exhaust pressure by the sliding contact means, the moment at the point of action of the exhaust pressure can be increased or decreased, and the moment of the exhaust pressure increases relative to the first sliding contact means in the second sliding contact means. The incremental value of the reaction force of the biasing means can be reduced,
Since it is possible to suppress an increase in exhaust pressure in a high engine speed range of the engine, it is possible to suppress a decrease in output in a high engine speed range of the engine as in the conventional example, and special control means is not required. The configuration can be simplified and the increase in manufacturing cost can be suppressed.
【００８０】また、第６の発明は、エンジンの運転状態
に応じて排気流路を切り換えて、低回転域と高回転域で
の排気騒音を減衰、吸収するようにした自動車用排気消
音装置において、排気圧力に応動して排気流路を切り換
える開閉バルブと、排気圧力に対抗して前記開閉バルブ
を閉弁方向に付勢する手段と、前記開閉バルブの回動角
の増大に応じて前記付勢手段の反力の増分を減少するバ
ネ定数変更手段とを備え、開閉バルブの回動角の増大に
応じて付勢手段の反力の増分値が徐々に減少し、排気の
圧力及び流量の変動に応じて円滑に開閉バルブの開閉を
行うことができ、エンジンの高回転域では付勢手段の反
力の増大を抑制して排気損失を低減でき、前記従来例の
ようなエンジンの高回転域における出力の低下を抑制す
ることが可能となる。According to a sixth aspect of the present invention, there is provided an exhaust muffler for an automobile in which an exhaust passage is switched in accordance with an operation state of an engine to attenuate and absorb exhaust noise in a low rotation range and a high rotation range. An opening / closing valve for switching an exhaust flow path in response to exhaust pressure; a means for urging the opening / closing valve in a valve closing direction against exhaust pressure; and an opening / closing valve for increasing the rotation angle of the opening / closing valve. Spring constant changing means for decreasing the increment of the reaction force of the urging means, the incremental value of the reaction force of the urging means gradually decreases in accordance with the increase in the rotation angle of the on-off valve, and the pressure and flow rate of the exhaust gas are reduced. The opening / closing valve can be smoothly opened / closed in accordance with the fluctuation, and in the high engine speed region, the increase in the reaction force of the urging means can be suppressed to reduce the exhaust loss, and the high engine speed as in the conventional example can be reduced. Output can be suppressed in the .
【００８１】また、第７の発明は、前記付勢手段は基端
を前記開閉バルブの回動軸から所定の位置に配設される
一方、自由端で前記開閉バルブに摺接し、付勢手段が摺
接する開閉バルブにはバネ定数変更手段として、開閉バ
ルブの回動角の増大に応じてこの回動角に応じて基端を
軸に回動する付勢手段の回動角の増分値を減少する所定
の摺接面を形成し、所定の摺接面に応じて付勢手段の回
動角の増分値は徐々に減少し、排気の圧力及び流量の変
動に応じて円滑に開閉バルブの開閉を行うことができ、
エンジンの高回転域では付勢手段の反力の増大を抑制し
て排気損失を低減でき、前記従来例のようなエンジンの
高回転域における出力の低下を抑制することが可能とな
り、特別な制御手段を必要としないため製造コストの増
大を抑制することができる。According to a seventh aspect of the present invention, the urging means has a base end disposed at a predetermined position from a rotation axis of the opening / closing valve, and has a free end slidingly contacting the opening / closing valve. As the spring constant changing means, the incremental value of the rotation angle of the urging means that rotates about the base end in accordance with the rotation angle of the opening / closing valve is increased as the spring constant changing means. A predetermined sliding contact surface that decreases is formed, and the incremental value of the rotation angle of the biasing means gradually decreases in accordance with the predetermined sliding contact surface, and the opening and closing valve of the opening and closing valve smoothly changes according to the change in the pressure and the flow rate of the exhaust gas. Can be opened and closed,
In the high engine speed range, it is possible to suppress an increase in the reaction force of the urging means to reduce exhaust loss, and it is possible to suppress a decrease in output in the high engine speed range as in the conventional example. Since no means is required, an increase in manufacturing cost can be suppressed.
【図１】本発明の実施例を示すマフラの断面図。FIG. 1 is a sectional view of a muffler showing an embodiment of the present invention.
【図２】同じくバルブ部の斜視図。FIG. 2 is a perspective view of a valve unit.
【図３】同じくバルブの動作を説明する概略図。FIG. 3 is a schematic diagram illustrating the operation of the valve.
【図４】第２の実施例を示すバルブの正面図。FIG. 4 is a front view of a valve showing a second embodiment.
【図５】同じく図４の矢視Ａ−Ａ図。FIG. 5 is an AA view of FIG. 4;
【図６】同じくバルブの動作を説明する概略図。FIG. 6 is a schematic diagram illustrating the operation of the valve.
【図７】第３の実施例を示すバルブの概略断面図。FIG. 7 is a schematic sectional view of a valve showing a third embodiment.
【図８】第４の実施例を示すバルブの概略断面図。FIG. 8 is a schematic sectional view of a valve showing a fourth embodiment.
【図９】同じくバルブの動作を説明する概略図。FIG. 9 is a schematic diagram for explaining the operation of the valve.
【図１０】同じくバルブの動作を説明する概略図。FIG. 10 is a schematic diagram illustrating the operation of the valve.
【図１１】第５の実施例を示すマフラの断面図。FIG. 11 is a sectional view of a muffler showing a fifth embodiment.
【図１２】同じく図１１のＢ−Ｂ矢視断面図。FIG. 12 is a sectional view taken along the line BB of FIG. 11;
【図１３】従来の例を示すマフラの断面図。FIG. 13 is a sectional view of a muffler showing a conventional example.
【図１４】同じく図１３のＣ−Ｃ矢視断面図。FIG. 14 is a sectional view taken along the line CC of FIG. 13;
１ マフラ ２〜４ 拡張室 ５ インレットチューブ １０、１１ テールチューブ １２ 貫通孔 １３ リターンスプリング １３Ａ 基端 １３Ｂ 自由端 １４ バルブ １４Ａ 凹部 １４Ｂ 屈曲位置 １５ 軸 ２４ バルブ ２４Ａ 頂部 ３４ バルブ ４０ リターンスプリング ４１ リターンスプリング ６０ カム ６０Ａ 頂部 DESCRIPTION OF SYMBOLS 1 Muffler 2-4 Expansion room 5 Inlet tube 10, 11 Tail tube 12 Through hole 13 Return spring 13A Base end 13B Free end 14 Valve 14A Depression 14B Bending position 15 Shaft 24 Valve 24A Top 34 Valve 40 Return spring 41 Return spring 60 Cam 60A top
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平６−221130（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) F01N 1/08 F01N 1/02 F01N 1/10 F01N 7/08 ────────────────────────────────────────────────── (5) References JP-A-6-221130 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) F01N 1/08 F01N 1/02 F01N 1 / 10 F01N 7/08
Claims (7)
切り換えて、低回転域と高回転域での排気騒音を減衰、
吸収するようにした自動車用排気消音装置において、排
気圧力に応動して排気流路を切り換える開閉バルブと、
排気圧力に対抗して前記開閉バルブを閉弁方向に付勢す
る手段と、前記開閉バルブの回動角が所定の値を越える
と前記付勢手段の反力の増分を減少するバネ定数変更手
段とを備えたことを特徴とする自動車用排気消音装置。An exhaust passage is switched according to an operation state of an engine to attenuate exhaust noise in a low rotation range and a high rotation range.
In an automobile exhaust silencer that is made to absorb, an open / close valve that switches an exhaust flow path in response to exhaust pressure,
Means for urging the on-off valve in the valve closing direction against exhaust pressure, and spring constant changing means for decreasing the increment of the reaction force of the urging means when the rotation angle of the on-off valve exceeds a predetermined value A vehicle exhaust silencer comprising:
回動軸から所定の位置に配設される一方、自由端で前記
開閉バルブに摺接し、付勢手段が摺接する開閉バルブに
はバネ定数変更手段として、開閉バルブの回動角が所定
値以下ではこの回動角に応じて基端を軸に回動する付勢
手段の回動角を第１の比率で増大させる第１の摺接面
と、開閉バルブの回動角が所定値を越えると前記第１の
比率よりも小さい第２の比率で回動角に応じて基端を軸
に回動する付勢手段の回動角を増大させる第２の摺接面
とをそれぞれ形成したことを特徴とする請求項１に記載
の自動車用排気消音装置。2. The urging means has a base end disposed at a predetermined position from a rotation axis of the on-off valve, and has a free end slidably in contact with the on-off valve, the urging means being in sliding contact with the on-off valve. Is a spring constant changing means that, when the turning angle of the opening / closing valve is equal to or less than a predetermined value, the turning angle of the urging means that turns around the base end according to the turning angle is increased by a first ratio. When the rotation angle of the opening / closing valve exceeds a predetermined value, the rotation of the urging means that rotates about the base end at a second ratio smaller than the first ratio in accordance with the rotation angle. 2. The exhaust muffler for an automobile according to claim 1, wherein a second sliding contact surface for increasing a moving angle is formed.
の所定の外部に配設されたカムと同期的に回動可能に形
成され、前記付勢手段は同じく所定の外部に配設される
とともに、基端を前記カムの回動軸から所定の位置に配
設される一方、自由端で前記カムに摺接し、バネ定数変
更手段はこのカムに形成されて開閉バルブの回動角が所
定値以下では開閉バルブの回動角の増大に応じて基端を
軸に回動する付勢手段の回動角を第１の比率で増大させ
る第１の摺接面と、開閉バルブの回動角が所定値を越え
ると前記第１の比率よりも小さい第２の比率で付勢手段
の回動角を第２の比率で増大させる第２の摺接面とをそ
れぞれ形成したことを特徴とする請求項１に記載の自動
車用排気消音装置。3. A rotating shaft of the opening / closing valve is formed so as to be rotatable synchronously with a cam provided outside a predetermined portion of the exhaust silencer, and the biasing means is also provided outside the predetermined portion. At the same time, the base end is disposed at a predetermined position from the rotation axis of the cam, while the free end is in sliding contact with the cam, and a spring constant changing means is formed on the cam so that the rotation angle of the open / close valve can be adjusted. When the rotation angle of the opening and closing valve is equal to or less than a predetermined value, the first sliding contact surface that increases the rotation angle of the urging means that rotates about the base end at a first ratio in accordance with the increase of the rotation angle of the opening and closing valve, and the rotation of the opening and closing valve. A second sliding contact surface for increasing the rotation angle of the biasing means at a second ratio at a second ratio smaller than the first ratio when the movement angle exceeds a predetermined value; The vehicle exhaust silencer according to claim 1, wherein:
回動軸と開閉バルブが付勢手段へ加える排気圧力の作用
点との距離を増大させて相対的に付勢手段の反力の増分
を減少させることを特徴とする請求項１に記載の自動車
用排気消音装置。4. The spring constant changing means increases a distance between a rotation axis of the opening / closing valve and a point of application of exhaust pressure applied to the urging means by the opening / closing valve to relatively increase a reaction force of the urging means. 2. The vehicle exhaust silencer according to claim 1, wherein the exhaust noise is reduced.
動軸から所定の位置に配設される一方、自由端で前記開
閉バルブに摺接し、付勢手段が摺接する開閉バルブには
バネ定数変更手段として、開閉バルブの回動角が所定値
以下では回動軸から第１の距離で前記付勢手段と摺接す
る第１の摺接手段と、開閉バルブの回動角が所定値を越
えると開閉バルブの回動軸から前記第１の距離よりも大
きい第２の距離で付勢手段と摺接する第２の摺接手段と
をそれぞれ形成したことを特徴とする請求項４に記載の
自動車用排気消音装置。5. The urging means has a base end disposed at a predetermined position from a rotation axis of the on-off valve, and has a free end slidably in contact with the on-off valve, the urging means being in sliding contact with the on-off valve. When the turning angle of the on-off valve is equal to or less than a predetermined value, the first sliding contact means that slides on the urging means at a first distance from the turning shaft, and the turning angle of the on-off valve is a predetermined value. to claim 4, characterized in that the second sliding contact means in contact biasing means in sliding from the rotation axis of the opening and closing valve exceeds the value in the second distance greater than said first distance were formed A vehicle exhaust silencer according to the above.
切り換えて、低回転域と高回転域での排気騒音を減衰、
吸収するようにした自動車用排気消音装置において、排
気圧力に応動して排気流路を切り換える開閉バルブと、
排気圧力に対抗して前記開閉バルブを閉弁方向に付勢す
る手段と、前記開閉バルブの回動角の増大に応じて前記
付勢手段の反力の増分を減少するバネ定数変更手段とを
備えたことを特徴とする自動車用排気消音装置。6. An exhaust passage is switched according to an operation state of an engine to attenuate exhaust noise in a low rotation range and a high rotation range.
In an automobile exhaust silencer that is made to absorb, an open / close valve that switches an exhaust flow path in response to exhaust pressure,
Means for urging the on-off valve in the valve-closing direction against exhaust pressure, and spring constant changing means for decreasing an increase in the reaction force of the urging means in accordance with an increase in the rotation angle of the on-off valve. An exhaust muffler for automobiles, comprising:
回動軸から所定の位置に配設される一方、自由端で前記
開閉バルブに摺接し、付勢手段が摺接する開閉バルブに
はバネ定数変更手段として、開閉バルブの回動角の増大
に応じてこの回動角に応じて基端を軸に回動する付勢手
段の回動角の増分値を減少する所定の曲面を形成したこ
とを特徴とする請求項６に記載の自動車用排気消音装
置。7. The urging means has a base end disposed at a predetermined position from a rotation axis of the on-off valve, and has a free end slidably in contact with the on-off valve, the urging means being in sliding contact with the on-off valve. Is a predetermined curved surface as a spring constant changing means, which decreases the increment value of the turning angle of the urging means that turns around the base end in accordance with the turning angle according to the increase of the turning angle of the opening / closing valve. 7. The exhaust muffler for an automobile according to claim 6, wherein the muffler is formed.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24635594A JP3326996B2 (en) | 1994-10-12 | 1994-10-12 | Automotive exhaust silencer |
| US08/429,091 US5614699A (en) | 1994-05-09 | 1995-04-26 | Automobile exhaust noise suppressor |
| KR1019950011550A KR0155237B1 (en) | 1994-05-09 | 1995-05-08 | Automobile exhaust noise suppressor |
| US08/797,332 US5739483A (en) | 1994-05-09 | 1997-02-10 | Automobile exhaust noise suppressor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24635594A JP3326996B2 (en) | 1994-10-12 | 1994-10-12 | Automotive exhaust silencer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08109815A JPH08109815A (en) | 1996-04-30 |
| JP3326996B2 true JP3326996B2 (en) | 2002-09-24 |
Family
ID=17147330
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24635594A Expired - Lifetime JP3326996B2 (en) | 1994-05-09 | 1994-10-12 | Automotive exhaust silencer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3326996B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2680104Y (en) * | 2004-04-05 | 2005-02-23 | 陈洁茹 | Furniture with pet chamber |
| JP2008255879A (en) | 2007-04-04 | 2008-10-23 | Nissan Motor Co Ltd | Method for controlling exhaust sound for vehicle and device for controlling exhaust sound for vehicle |
| JP4935615B2 (en) * | 2007-10-15 | 2012-05-23 | 日産自動車株式会社 | Valve unit for silencer |
| JP4775355B2 (en) * | 2007-10-15 | 2011-09-21 | 日産自動車株式会社 | Valve unit for silencer |
| JP4719777B2 (en) * | 2008-07-16 | 2011-07-06 | 株式会社ユタカ技研 | Engine exhaust control valve |
| JP2012062878A (en) * | 2010-09-17 | 2012-03-29 | Sango Co Ltd | Exhaust control valve |
| FR2965296B1 (en) * | 2010-09-29 | 2012-10-26 | Faurecia Sys Echappement | VALVE FOR AN EXHAUST LINE MUFFLER OF A MOTOR VEHICLE |
| CN102705043B (en) * | 2012-06-05 | 2014-12-10 | 徐州重型机械有限公司 | Crane and silencer of crane exhaust system |
| JP6473306B2 (en) * | 2014-09-24 | 2019-02-20 | 川崎重工業株式会社 | Back pressure valve of engine exhaust silencer |
| JP7081144B2 (en) * | 2017-12-27 | 2022-06-07 | スズキ株式会社 | Engine exhaust |
-
1994
- 1994-10-12 JP JP24635594A patent/JP3326996B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08109815A (en) | 1996-04-30 |
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