JP2000097008A - Expansion type muffler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion type muffler which can be changed over between the normal service mode with low noise emission and the high output service mode using a simple structure and can prevent the emission of excessive exhaust noise by the two-stage expansion even in the high output service mode. SOLUTION: The inside of a casing 2 is partitioned by plates 6 and 7 so that a first expansion chamber 11 where an inlet pipe 14 is connected, a second expansion chamber 12 in communication to the first 11 through a communication pipe, and a third expansion chamber 13 which is in communication with the second expansion chamber 12 through a pipe and where an outlet pipe 15 is connected are formed to form an expansion type muffler, wherein a tubing 21 to generate communication between the first expansion chamber 11 and third expansion chamber 13 is installed on the partitioning plate, and an opening/closing valve 31 for this tubing 21 is installed.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】この発明は、オートバイや自
動車のエンジンの排気音を減ずる膨張型マフラに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflatable muffler for reducing exhaust noise of a motorcycle or an automobile engine.

【０００２】[0002]

【従来の技術】オートバイや自動車のエンジンの排気音
を減ずるマフラとしては、ケーシング内を複数の膨張室
に区画して各膨張室を連通管により連通した膨張型のマ
フラが多く用いられている。2. Description of the Related Art As a muffler for reducing the exhaust noise of a motorcycle or automobile engine, an expansion type muffler in which a casing is divided into a plurality of expansion chambers and each expansion chamber is communicated by a communication pipe is often used.

【０００３】ところがこの膨張型マフラは、排気音は十
分消音され市街地走行には好適であるが、排気ガスの多
段にわたる膨張と絞りにより排気抵抗が大きく、エンジ
ン出力は低下したものとなる。一方、山野やサーキット
などにおけるスポーツ走行には、消音性能は多少低下し
てもエンジン出力の向上をはかることが望まれるが、い
ちいちスポーツマフラに付替えるのはマフラを２組用意
しておく必要があるうえ、付替けに手間がかかるので好
ましくない。[0003] However, this expansion type muffler has a sufficiently low exhaust noise and is suitable for traveling in an urban area. However, the exhaust resistance is large due to the multi-stage expansion and throttling of exhaust gas, and the engine output is reduced. On the other hand, it is desirable to improve the engine output even if the noise reduction performance is slightly reduced for sports driving in Yamano and circuits, but it is necessary to prepare two sets of mufflers to replace each with a sports muffler. In addition, it is not preferable because it takes time to change.

【０００４】そこで１組のマフラで消音およびエンジン
出力特性を切換えて使用できるものとして、たとえば特
公平４−７４５２３号公報においては、排気ガスを入口
管から３室の膨張室を経て第２マフラー管へ流出させる
低騒音の使用態様と、入口管から第２マフラー管へと直
接流出させる高出力の使用態様とに切替えられるように
した消音器が提案されているが、高出力の使用態様では
排気ガスは全く膨張室を通らないためその騒音レベルは
非常に大きく、使用場所はごく限られたものとなってし
まう。また低騒音の使用態様ではエンジン出力の低下が
大きく、両使用態様の中間的な、エンジン出力は向上す
るが騒音レベルもやや大きいといった態様での使用はで
きない。For example, Japanese Unexamined Patent Publication No. Hei 4-74523 discloses that a set of mufflers can be used to switch the silencing and engine output characteristics. For example, in Japanese Patent Publication No. 4-74523, exhaust gas is supplied from an inlet pipe to a second muffler pipe through three expansion chambers. A silencer has been proposed that can be switched between a low noise use mode in which the exhaust pipe flows out of the exhaust pipe and a high output use mode in which the output pipe directly flows from the inlet pipe to the second muffler pipe. Since the gas does not pass through the expansion chamber at all, its noise level is very high and its use place is very limited. Further, in the use mode with low noise, the engine output is greatly reduced, and the engine output is improved between the two use modes, but it cannot be used in a mode in which the noise level is slightly large.

【０００５】また実開昭５９−６２２１８号公報には、
各膨張室間を連通する２つの通気路のうちの１方の通気
路に着座する弁を、吸気管負圧によりリンクレバー機構
を介して駆動し、エンジンの高負荷運転時に上記弁を開
方向に駆動して排気抵抗を減少させるモードが選択でき
るようにした可変消音器が提案されている。しかしこの
消音器ではエンジン出力向上がはかれるのは高負荷運転
時のみであり、また排気は３室の膨張室を通って３段の
膨張と絞りを繰返すので、排気抵抗の減少、従ってエン
ジン出力の向上の巾は、あまり大きくとれず、さらにリ
ンクレバー機構は複雑で消音器側方にスペースを必要と
し、揺動する弁軸のケーシング貫通部の防音や高温排気
ガスもれ防止などのために、複雑な機構を必要とする。In Japanese Utility Model Laid-Open Publication No. 59-62218,
A valve seated in one of the two air passages communicating between the expansion chambers is driven by a negative pressure of the intake pipe via a link lever mechanism, and the valve opens in a high load operation of the engine. A variable muffler has been proposed in which a mode for reducing exhaust resistance by driving the muffler can be selected. However, with this silencer, the engine output can be improved only during high-load operation, and the exhaust gas repeats three stages of expansion and throttling through the three expansion chambers, reducing the exhaust resistance and thus reducing the engine output. The range of improvement is not very large, and the link lever mechanism is complicated and requires space on the side of the muffler.In order to prevent sound from leaking through the casing of the oscillating valve shaft and prevent leakage of high-temperature exhaust gas, Requires complex mechanisms.

【０００６】[0006]

【発明が解決しようとする課題】この発明は上記従来の
問題点を解決しようとするもので、簡潔な構造によって
通常の低騒音の使用態様と、高出力の使用態様に切替え
られ、高出力の使用態様においても２段膨張により過大
排気音の発生が防止される膨張型マフラを提供すること
を目的とする。SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and can be switched between a normal low-noise use mode and a high-output use mode by a simple structure, thereby providing a high-output mode. It is another object of the present invention to provide an expansion type muffler in which an excessive exhaust sound is prevented from being generated by two-stage expansion even in a usage mode.

【０００７】請求項２〜３記載の発明は、上記の目的に
加えて、高出力の使用態様に比べて低騒音であり低騒音
の使用態様に比べてエンジンの高出力が得られる、中間
特性の使用態様への切替えもおこなえ、走行環境や所望
の出力特性などに応じて３段階の使用態様が得られる膨
張型マフラを提供することを目的とする。[0007] In addition to the above objects, the invention according to claims 2 to 3 has an intermediate characteristic in which low noise is obtained as compared with a high output use mode and high engine output is obtained as compared with a low noise use mode. It is an object of the present invention to provide an inflatable muffler which can be switched to a use mode and can obtain a three-stage use mode according to a traveling environment and a desired output characteristic.

【０００８】[0008]

【課題を解決するための手段】請求項１記載の発明の膨
張型マフラは、ケーシング内を仕切板で仕切って、入口
管が接続された第１膨張室と、連通管により前記第１膨
張室と連通する第２膨張室と、連通管により前記第２膨
張室と連通し出口管が接続された第３膨張室とを設けた
膨張型マフラにおいて、前記第１膨張室と前記第３膨張
室とを連通する管体を前記仕切板に取付け、前記管体を
開閉する開閉弁を設けたことを特徴とする。According to a first aspect of the present invention, there is provided an inflatable muffler according to the first aspect of the present invention, wherein the inside of a casing is partitioned by a partition plate, and a first inflatable chamber to which an inlet pipe is connected and a first inflatable chamber by a communication pipe. And a third expansion chamber provided with a second expansion chamber communicating with the first expansion chamber and a third expansion chamber communicating with the second expansion chamber through a communication pipe and connected to an outlet pipe. A pipe body communicating with the pipe is attached to the partition plate, and an on-off valve for opening and closing the pipe body is provided.

【０００９】請求項２記載の発明の膨張型マフラは、ケ
ーシング内を仕切板で仕切って、入口管が接続された第
１膨張室と、連通管により前記第１膨張室と連通する第
２膨張室と、連通管により前記第２膨張室と連通し出口
管が接続された第３膨張室とを設けた膨張型マフラにお
いて、一端部が前記第１膨張室に開口し前記第２および
第３膨張室内に延びて該第２および第３膨張室に開口す
る開口部を有する管体を、前記仕切板に取付け、前記各
開口部を開閉して前記管体を閉鎖状態から該管体を介し
て前記第１膨張室が前記第２膨張室に連通する中間連通
状態、および前記第１膨張室が前記第２および第３膨張
室に連通する短絡連通状態に切替える切替弁を設けたこ
とを特徴とする。According to a second aspect of the present invention, there is provided an expansion type muffler in which a casing is partitioned by a partition plate, and a first expansion chamber to which an inlet pipe is connected and a second expansion chamber which communicates with the first expansion chamber by a communication pipe. An expansion type muffler provided with a chamber and a third expansion chamber connected to the second expansion chamber by a communication pipe and connected to an outlet pipe, wherein one end of the muffler is opened to the first expansion chamber and the second and third mufflers are opened. A pipe having an opening extending into the expansion chamber and opening to the second and third expansion chambers is attached to the partition plate, and the openings are opened and closed to close the pipe from the closed state through the pipe. A switching valve for switching between an intermediate communication state in which the first expansion chamber communicates with the second expansion chamber and a short-circuit communication state in which the first expansion chamber communicates with the second and third expansion chambers. And

【００１０】また請求項３記載の発明の膨張型マフラ
は、ケーシング内を仕切板で仕切って、入口管が接続さ
れた第１膨張室と、連通管により前記第１膨張室と連通
する第２膨張室と、連通管により前記第２膨張室と連通
し出口管が接続された第３膨張室とを設けた膨張型マフ
ラにおいて、一端部が前記第１膨張室に開口し前記第２
および第３膨張室内に延びて該第２および第３膨張室に
開口する開口部を有する管体を、前記仕切板に取付け、
前記各開口部を開閉して前記管体を閉鎖状態から該管体
を介して前記第１膨張室が前記第２膨張室に連通する中
間連通状態、および前記第１膨張室が前記第３膨張室に
連通する短絡連通状態に切替える切替弁を設けたことを
特徴とする。According to a third aspect of the present invention, in the expansion type muffler, the casing is partitioned by a partition plate, and the first expansion chamber connected to the inlet pipe and the second expansion chamber connected to the first expansion chamber by a communication pipe. In an expansion type muffler provided with an expansion chamber and a third expansion chamber connected to the second expansion chamber by a communication pipe and connected to an outlet pipe, one end is opened to the first expansion chamber and the second expansion chamber is opened.
And a pipe extending into the third expansion chamber and having an opening opening to the second and third expansion chambers is attached to the partition plate;
The first expansion chamber is communicated with the second expansion chamber through the pipe body from the closed state by opening and closing the respective openings, and the first expansion chamber is in the third expansion state. A switching valve for switching to a short-circuit communication state communicating with the chamber is provided.

【００１１】請求項２および３記載の発明においては、
切替弁としては種々の形式のものを用いることができる
が、請求項４記載の発明のように、前記管体内に、回転
および／または摺動自在に嵌合し一端部が底板で閉鎖さ
れた筒状の弁体と、前記底板に基部を固着され前記ケー
シングの端板を貫通して該端板の外側に操作端部を形成
した弁軸とから成り、この操作端部の回転および／また
は押引操作により前記管体の閉鎖および連通状態の切替
えをおこなうようにした切替弁を用いれば、１個の弁体
に固着した弁軸の操作端部を端板の外側で操作すること
により弁体内の排気ガス流の切替え、従ってマフラの各
使用態様の切替えをおこなうことができ、これらの切替
操作が容易であるとともに切替弁の構造が簡潔であるの
で、特に好ましい。[0011] In the second and third aspects of the invention,
As the switching valve, various types can be used. As in the invention according to claim 4, the switching valve is rotatably and / or slidably fitted in the pipe and one end is closed by a bottom plate. It comprises a cylindrical valve body, and a valve shaft having a base fixed to the bottom plate and penetrating through an end plate of the casing to form an operation end outside the end plate, and rotating and / or rotating the operation end. By using a switching valve that closes and switches the communication state by a push-pull operation, the valve is operated by operating the operating end of the valve shaft fixed to one valve body outside the end plate. It is particularly preferable because it is possible to switch the exhaust gas flow in the body, and thus to switch the manner in which the muffler is used, so that the switching operation is easy and the structure of the switching valve is simple.

【００１２】[0012]

【発明の実施の形態】以下この発明の実施の形態を、そ
の第１例（請求項１記載の発明に対応）を示す図１〜図
６を参照しながら説明する。図中１は膨張型マフラで、
２はそのケーシングであり、外筒３の両端部を端板４，
５で閉鎖してなる。ケーシング２の内部は仕切板６，７
で仕切って、第１膨張室１１，第２膨張室１２，および
第３膨張室１３に区画し、各膨張室を連通する連通管
８，９を仕切板６，７に固設し、端板４には第１膨張室
１１に開口する入口管１４を、端板５には第３膨張室１
３に開口する出口管１５を固設してあり、上記各部は溶
接等により結合されている。１６は出口管１５の開口部
を包囲する保護筒で、端板５に固設されている。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. 1 to 6 showing a first example (corresponding to the first aspect of the present invention). 1 is an inflatable muffler in the figure.
Numeral 2 is the casing, and both ends of the outer cylinder 3 are end plates 4,
Closed at 5. The interior of the casing 2 has partition plates 6 and 7
The first expansion chamber 11, the second expansion chamber 12, and the third expansion chamber 13 are partitioned, and communication pipes 8, 9 for communicating the respective expansion chambers are fixed to the partition plates 6, 7, and the end plate is provided. 4 is an inlet pipe 14 opening to the first expansion chamber 11, and the end plate 5 is a third expansion chamber 1
An outlet pipe 15 that opens to 3 is fixedly provided, and the above-mentioned parts are connected by welding or the like. Reference numeral 16 denotes a protective cylinder surrounding the opening of the outlet pipe 15 and is fixed to the end plate 5.

【００１３】一方２１は、第１膨張室１１と第３膨張室
１３を連通する管体で、その一端部２１ａは第１膨張室
１１に開口し、他端部２１ｂは仕切板７に突当溶接さ
れ、中間部は仕切板６に溶接されており、第３膨張室１
３に開口する２個の開口部２２，２２を管壁部に穿設し
てある。On the other hand, reference numeral 21 denotes a tube which communicates the first expansion chamber 11 and the third expansion chamber 13 with one end 21a opening to the first expansion chamber 11 and the other end 21b abutting against the partition plate 7. The intermediate portion is welded to the partition plate 6, and the third expansion chamber 1 is welded.
Two openings 22, 22 opening to 3 are bored in the tube wall.

【００１４】３１はこの開口部２２を開閉する開閉弁
で、管体２１内に摺動自在に嵌装された弁体３２と、こ
の弁体３２に基部を固着した弁軸３３とから成る。弁体
３２は筒状部３２ａの一端を底板３２ｂで閉鎖したカッ
プ状を呈し、弁軸３３は底板３２ｂ部に溶接されてい
る。また弁軸３３はケーシングの端板５を貫通して、該
端板の外側に操作端部３４が形成されている。この操作
端部３４は、電動機などを用いた電動駆動機構やワイヤ
リンケージ機構等により操作することもできるが、この
例は手動操作式の場合を示し、弁軸３３の先端部に固着
したつまみから成る操作端部３４を用いている。７ａは
仕切板７の弁軸３３貫通部に設けた穴で、弁体３２摺動
時の空気流通用に弁軸３３よりやや大径としてある。ま
た３４ａは、弁軸３３、従って弁体３２の回転状態を示
すために操作端部３４に付したマークである。Reference numeral 31 denotes an on-off valve for opening and closing the opening 22. The on-off valve 31 includes a valve body 32 slidably fitted in the tube 21 and a valve shaft 33 having a base fixed to the valve body 32. The valve body 32 has a cup shape in which one end of a cylindrical portion 32a is closed by a bottom plate 32b, and the valve shaft 33 is welded to the bottom plate 32b. The valve shaft 33 extends through the end plate 5 of the casing, and an operation end portion 34 is formed outside the end plate. The operating end 34 can be operated by an electric drive mechanism using an electric motor or the like, a wire linkage mechanism, or the like, but this example shows a case of a manual operation type, in which a knob fixed to the distal end of the valve shaft 33 is used. The operating end 34 of FIG. Reference numeral 7a denotes a hole provided in the partition plate 7 at a portion where the valve shaft 33 penetrates, and has a slightly larger diameter than the valve shaft 33 for air flow when the valve body 32 slides. Numeral 34a is a mark attached to the operation end portion 34 to indicate the rotation state of the valve shaft 33 and thus the valve body 32.

【００１５】また３５は、端板５の弁軸３３貫通部に設
けたロック装置で、図４および図５に示すように、弁軸
３３に少量のすきまをもって嵌合する貫通穴３６ａを中
央部にそなえ、コレットチャックと同様な、すり割り部
３６ｂをそなえた円錐体状のコレット３６と、このコレ
ット３６の円錐面部に係合する円錐面３７ａを内径側に
形成し、端板５に設けたねじ穴３８にねじ込まれるナッ
ト３７とから成り、ナット３７の端板５への締込みによ
り円錐面３７ａによって押圧されたコレット３６の爪部
３６ｃにより、弁軸３３が挾圧されてロック状態とな
り、ナット３７をゆるめれば上記ロックは解除されるも
のである。Reference numeral 35 denotes a lock device provided at a portion of the end plate 5 that penetrates the valve shaft 33. As shown in FIGS. 4 and 5, a through hole 36a fitted to the valve shaft 33 with a small clearance is provided at the center. In addition, a conical collet 36 having a slit portion 36b similar to the collet chuck and a conical surface 37a engaging with the conical surface portion of the collet 36 are formed on the inner diameter side and provided on the end plate 5. And a nut 37 screwed into the screw hole 38. The pawl portion 36c of the collet 36 pressed by the conical surface 37a when the nut 37 is tightened into the end plate 5 causes the valve shaft 33 to be clamped and locked. If the nut 37 is loosened, the lock is released.

【００１６】上記構成の膨張型マフラ１を、通常の市街
地走行に適した低騒音の使用態様で使用するには、操作
端部３４を端板５の内方へ押込んでロック装置３５によ
りロックした状態、すなわち図１および図２に示す状態
で使用する。弁体３２は管体２１の開口部２２を閉鎖し
ているので、入口管１４から第１膨張室１１内に流入し
たエンジンの排気ガスは、全量が連通管８を経て第２膨
張室１２へ、次いで連通管９を経て第３膨張室１３へと
流れ、３段階の膨張および絞り作用を受けて十分消音さ
れ、出口管１５から流出する。In order to use the inflatable muffler 1 having the above-described structure in a low-noise mode suitable for ordinary city driving, the operating end 34 is pushed into the end plate 5 and locked by the lock device 35. Used in the state, that is, the state shown in FIG. 1 and FIG. Since the valve body 32 closes the opening 22 of the tube 21, the entire amount of the engine exhaust gas flowing into the first expansion chamber 11 from the inlet pipe 14 passes through the communication pipe 8 to the second expansion chamber 12. Then, it flows into the third expansion chamber 13 via the communication pipe 9, undergoes three-stage expansion and throttling actions, is sufficiently silenced, and flows out of the outlet pipe 15.

【００１７】次に高出力の使用態様で使用するには、ロ
ック装置３５のロックを解除し、操作端部３４を手指等
により引張り、図６に示すように弁体３２の底板３２ｂ
が仕切板７に当るまで引出して、ロック装置３５により
ロックする。これによって図６に示すように弁体３２の
矢印Ｘ方向への移動により管体２１の開口部２２，２２
が開放状態となるので、入口管１４から第１膨張室１１
内へ流入した排気ガスは、一部は前記低騒音の使用態様
と同様に連通管８，第２膨張室１２，連通管９を経て第
３膨張室１３へと流れるが、この流通路の排気抵抗より
も管体２１およびその開口部２２，２２から成る短絡流
路を流れるときの排気抵抗の方が小さいので、排ガスの
大半はこの管体２１および開口部２２，２２を経て第１
膨張室１１から第３膨張室１３へ短絡流として流れ、第
２膨張室１２よりの排ガス流と共に出口管１５から流出
する。Next, in order to use the device in a high output mode, the lock device 35 is unlocked, the operating end 34 is pulled by a finger or the like, and the bottom plate 32b of the valve body 32 as shown in FIG.
Is pulled out until it hits the partition plate 7 and locked by the lock device 35. As a result, as shown in FIG.
Is opened, so that the first expansion chamber 11
A part of the exhaust gas flowing into the inside flows through the communication pipe 8, the second expansion chamber 12, and the communication pipe 9 to the third expansion chamber 13 in the same manner as in the low noise use mode. Since the exhaust resistance when flowing through the short-circuit flow path composed of the pipe 21 and the openings 22, 22 is smaller than the resistance, most of the exhaust gas passes through the pipe 21 and the openings 22, 22 and then passes through the first pipe 21.
It flows as a short-circuit flow from the expansion chamber 11 to the third expansion chamber 13, and flows out of the outlet pipe 15 together with the exhaust gas flow from the second expansion chamber 12.

【００１８】そして上記短絡流路の形成により排ガスの
排気抵抗は、前記低騒音の使用態様のときよりも大巾に
低減化され、エンジンは高出力で運転されるのである。
またこの運転状態においては、排気ガスは上記短絡流分
は第１膨張室１１と第３膨張室１３による２段階の膨張
・絞り作用を、第２膨張室１２を通る非短絡流分は３段
階の膨張・絞り作用を受けるので、膨張室を通過しない
排気ガスに比べて排気騒音レベルは大巾に低減化され、
過大排気音の発生が防止されるのである。The exhaust resistance of the exhaust gas is greatly reduced by the formation of the short-circuit flow path as compared with the low noise use mode, and the engine is operated at a high output.
In this operating state, the short-circuit flow of the exhaust gas has a two-stage expansion and throttling action by the first expansion chamber 11 and the third expansion chamber 13, and the non-short-circuit flow of the exhaust gas has a three-stage flow through the second expansion chamber 12. , The exhaust noise level is greatly reduced compared to exhaust gas that does not pass through the expansion chamber.
The generation of excessive exhaust noise is prevented.

【００１９】なお上記の例では、管体２１の管壁に設け
た開口部２２を弁体３２の筒状部３２ａのすべり動作で
開閉するようにしたが、図７に示すように短尺の管体２
３を仕切板６に溶接により取付け、弁体３２の筒状部３
２ａに穴３９を穿設しておき、弁軸３３と共に矢印Ｘ方
向へ摺動した弁体３２の穴３９を管体２３外の鎖線４０
で示す位置に移動することにより、管体２３を開状態と
し、反対動作で閉状態とするすべり弁形式の開閉弁４１
を用いてもよい。In the above example, the opening 22 formed in the tube wall of the tube 21 is opened and closed by the sliding operation of the cylindrical portion 32a of the valve body 32. However, as shown in FIG. Body 2
3 is attached to the partition plate 6 by welding.
A hole 39 is drilled in 2a, and the hole 39 of the valve body 32 slid in the direction of the arrow X together with the valve shaft 33 is inserted into a chain line 40 outside the tube body 23.
The slide valve-type on-off valve 41 is moved to the position shown by the arrow to open the pipe 23 and close it in the opposite operation.
May be used.

【００２０】また図８および図９に示すように、図１の
開閉弁３１において、弁体３２の筒状部３２ａに穴４２
を穿設し、弁軸３３を９０度回動させてこの穴４２と管
体２１の開口部２２を連通させることにより、管体２１
を開状態とし、９０度反対方向に回動させて図８および
図９に示すように開口部２２および穴４２が閉鎖された
閉状態とする形式の、回転弁式の開閉弁４３を用いるこ
ともできる。あるいは、管体２３の端部に係脱されるポ
ペット弁など、さらに他形式の開閉弁の採用もできる。As shown in FIGS. 8 and 9, in the on-off valve 31 shown in FIG.
Is formed, and the valve shaft 33 is rotated by 90 degrees so that the hole 42 and the opening 22 of the tube 21 communicate with each other.
Is opened, and a rotary valve-type on-off valve 43 of a type in which the opening 22 and the hole 42 are closed as shown in FIGS. Can also. Alternatively, other types of opening / closing valves such as a poppet valve engaged with and disengaged from the end of the tube 23 can be employed.

【００２１】次にこの発明の実施の形態の第２例（請求
項２記載の発明に対応）を、図１０〜図１５により説明
する。図中、前記の例と同一または相当部分には同一符
号を付して図示し、それらの詳細な説明は省略する。
（以下他の例も同様とする。）Next, a second embodiment of the present invention (corresponding to the second aspect of the present invention) will be described with reference to FIGS. In the figure, the same or corresponding parts as those in the above example are denoted by the same reference numerals, and detailed description thereof will be omitted.
(The same applies to other examples below.)

【００２２】図において２４は、一端部２４ａが第１膨
張室１１に開口し、第２膨張室１２および第３膨張室１
３内に延びる管体で、仕切板６，７（いずれか一方でも
よい）に溶接され、第２膨張室１２に開口する２個の開
口部２５，２５、および第３膨張室１３に開口する２個
の開口部２６，２６を管壁部に穿設してある。In FIG. 2, reference numeral 24 denotes an end portion 24a opened to the first expansion chamber 11, and the second expansion chamber 12 and the third expansion chamber 1 are opened.
3 is a pipe body that is welded to the partition plates 6 and 7 (or one of them) and is opened to the second expansion chamber 12 and the two openings 25 and 25 and the third expansion chamber 13. Two openings 26, 26 are drilled in the tube wall.

【００２３】５１は切替弁で、管体２４内に回転および
摺動自在に嵌装された弁体３２と、この弁体３２に基部
を固着した弁軸３３とから成る。弁体３２は前記第１例
よりも長尺の筒状部３２ａを有し、この筒状部３２ａに
は、図１０における開口部２５に対応する上下位置に、
２個の穴５２，５２を穿設してある。そして図１０に示
す弁軸３３の操作端部３４を押込んだ状態で、筒状部３
２ａの先端は、開口部２６を閉鎖している。Reference numeral 51 denotes a switching valve, which comprises a valve body 32 rotatably and slidably fitted in the tube 24, and a valve shaft 33 having a base fixed to the valve body 32. The valve body 32 has a tubular portion 32a which is longer than the first example, and the tubular portion 32a has a vertical position corresponding to the opening 25 in FIG.
Two holes 52, 52 are drilled. Then, with the operating end 34 of the valve shaft 33 shown in FIG.
The tip of 2 a closes the opening 26.

【００２４】また管体２４の底部には、図１３および図
１４に示すように、弁体３２の回転および摺動を規制す
る平面形状Ｌ形のガイド溝５３が穿設され、弁体３２の
筒状部３２ａに固設したピン５４が、このガイド溝５３
に、該溝に沿って移動できるように嵌合している。As shown in FIGS. 13 and 14, a flat L-shaped guide groove 53 for restricting rotation and sliding of the valve body 32 is formed in the bottom of the tube body 24. The pin 54 fixed to the cylindrical portion 32a is
, So as to be movable along the groove.

【００２５】上記構成の膨張型マフラ５０を、通常の市
街地走行に適した低騒音の使用態様で使用するには、操
作端部３４を端板５の内方へ押込んでさらに反時計方向
へ回転させ、ピン５４がガイド溝５３の先端部５３ａに
当った位置でロック装置３５によりロックした状態、す
なわち図１０〜図１３に示す状態で使用する。弁体３２
は管体２４の開口部２５および２６を閉鎖しているの
で、入口管１４から第１膨張室１１内に流入したエンジ
ンの排気ガスは、全量が連通管８を経て第２膨張室１２
へ、次いで連通管９を経て第３膨張室１３へと流れ、３
段階の膨張および絞り作用を受けて十分消音され、出口
管１５から流出する。In order to use the inflatable muffler 50 having the above-described configuration in a low noise use mode suitable for ordinary city driving, the operating end 34 is pushed inward of the end plate 5 and further rotated counterclockwise. Then, the pin 54 is used in a state where it is locked by the lock device 35 at a position where the pin 54 contacts the front end portion 53a of the guide groove 53, that is, a state shown in FIGS. Valve 32
Has closed the openings 25 and 26 of the pipe 24, the entire amount of the exhaust gas of the engine that has flowed into the first expansion chamber 11 from the inlet pipe 14 via the communication pipe 8 passes through the second expansion chamber 12.
And then to the third expansion chamber 13 via the communication pipe 9,
The sound is sufficiently silenced by the stepwise expansion and throttling action, and flows out of the outlet pipe 15.

【００２６】次に低騒音の使用態様と後述の高出力の使
用態様の中間の騒音および出力特性を有する中間特性の
使用態様で使用するには、ロック装置３５のロックを解
除し、操作端部３４を手指等で時計方向へ回転させ、ピ
ン５４がガイド溝５３の曲り角部５３ｂに当った状態
（図１４にこのときのピン５４を鎖線で示す）でロック
装置３５によりロックして、使用する。これによって弁
体３２は図１０〜図１３の状態から９０度回転し、図１
５に示すように弁体３２の穴５２が管体２４の開口部２
５に連通するので、第１膨張室１１が管体２４（および
弁体３２）を介して第２膨張室１２に連通する中間連通
状態となる。Next, in order to use the device in the use mode of the intermediate characteristic having the noise and output characteristics intermediate between the use mode of the low noise and the use mode of the high output described later, the lock of the lock device 35 is released, and the operation end portion is used. The pin 34 is rotated clockwise with a finger or the like, and the pin 54 is used by being locked by the lock device 35 in a state where the pin 54 contacts the bend 53b of the guide groove 53 (in FIG. 14, the pin 54 is shown by a chain line). . As a result, the valve body 32 rotates 90 degrees from the state shown in FIGS.
As shown in FIG. 5, the hole 52 of the valve body 32 is
5, the first expansion chamber 11 is in an intermediate communication state in which it communicates with the second expansion chamber 12 via the pipe 24 (and the valve body 32).

【００２７】この状態では、入口管１４から第１膨張室
１１へ流入した排気ガスは、一部は連通管８を経て、他
は上記の管体２４を経て、第２膨張室１２へ流入し、合
流後連通管９を経て第３膨張室１３へと流れる。これに
よって第１膨張室１１から第２膨張室１２へ流れる排気
ガスの排気抵抗、従ってマフラ全体の排気抵抗が、前記
低騒音の使用態様よりも低減化され、該使用態様よりも
エンジンは高出力で運転されるのである。またこの運転
状態においては、排気ガスは、全量が第１膨張室１１〜
第３膨張室１３を流通し３段階の膨張・絞り作用を受け
るので、前記低騒音の使用態様に近い消音特性が得られ
るのである。In this state, the exhaust gas flowing from the inlet pipe 14 into the first expansion chamber 11 flows into the second expansion chamber 12 partly through the communication pipe 8 and the other part through the pipe 24 described above. After the confluence, it flows to the third expansion chamber 13 via the communication pipe 9. As a result, the exhaust resistance of the exhaust gas flowing from the first expansion chamber 11 to the second expansion chamber 12, and hence the exhaust resistance of the muffler as a whole, is reduced as compared with the low noise use mode, and the engine has a higher output than the low noise use mode. It is driven by. Further, in this operation state, the exhaust gas is entirely in the first expansion chambers 11 to 11.
Since the gas flows through the third expansion chamber 13 and undergoes the three-stage expansion / throttle action, noise reduction characteristics close to the low-noise usage mode can be obtained.

【００２８】次に高出力の使用態様で使用するには、ロ
ック装置３５のロックを解除し、上記中間特性の使用態
様から操作端部３４を手指等により引張り、図１６に示
すように弁体３２の底板３２ｂが端板５に当るまで引出
して、ロック装置３５によりロックする。これによって
図１６に示すように弁体３２の矢印Ｘ方向への移動によ
り管体２４の開口部２６が開放状態となり、さらに弁体
３２の穴５２が第２膨張室１２に開口するので、第１膨
張室１１が第２膨張室１２および第３膨張室１３に連通
する短絡連通状態となる。この状態では、入口管１４か
ら第１膨張室１１内へ流入した排気ガスは、一部は前記
中間特性の使用態様と同様に連通管８および管体２４を
経て第２膨張室１２へ流入し、連通管９を経て第３膨張
室１３へと流れるが、この流通路の排気抵抗よりも管体
２４およびその開口部２６，２６から成る短絡流路を流
れるときの排気抵抗の方が小さいので、排ガスの大半は
この管体２４および開口部２６，２６を経て第１膨張室
１１から第３膨張室１３へ短絡流として流れ、第２膨張
室１２よりの排ガス流と共に出口管１５から流出する。Next, for use in a high output use mode, the lock of the lock device 35 is released, and the operating end 34 is pulled by a finger or the like from the use mode of the above intermediate characteristic, and as shown in FIG. 32 is pulled out until the bottom plate 32b hits the end plate 5 and locked by the lock device 35. As a result, as shown in FIG. 16, the opening 26 of the tube 24 is opened by the movement of the valve body 32 in the direction of the arrow X, and the hole 52 of the valve body 32 is opened in the second expansion chamber 12. The first expansion chamber 11 is in a short-circuit communication state in which the second expansion chamber 12 and the third expansion chamber 13 communicate with each other. In this state, a part of the exhaust gas flowing into the first expansion chamber 11 from the inlet pipe 14 flows into the second expansion chamber 12 via the communication pipe 8 and the pipe 24 in the same manner as in the use mode of the intermediate characteristic. Flows through the communication pipe 9 to the third expansion chamber 13, but the exhaust resistance when flowing through the short-circuit flow path formed by the pipe 24 and the openings 26, 26 is smaller than the exhaust resistance of this flow passage. Most of the exhaust gas flows as a short-circuit flow from the first expansion chamber 11 to the third expansion chamber 13 through the pipe 24 and the openings 26, 26, and flows out of the outlet pipe 15 together with the exhaust gas flow from the second expansion chamber 12. .

【００２９】そして上記短絡流路の形成により排ガスの
排気抵抗は、前記低騒音の使用態様のときよりも大巾に
低減化され、前記中間特性の使用態様のときよりも低減
化され、エンジンは高出力で運転されるのである。また
この運転状態においては、排気ガスは上記短絡流分は第
１膨張室１１と第３膨張室１３による２段階の膨張・絞
り作用を、第２膨張室１２を通る非短絡流分は３段階の
膨張・絞り作用を受けるので、膨張室を通過しない排気
ガスに比べて排気騒音レベルは大巾に低減化され、過大
排気音の発生が防止されるのである。The exhaust resistance of the exhaust gas is greatly reduced by the formation of the short-circuit flow path as compared with the low noise use mode, and the exhaust resistance is reduced as compared with the intermediate characteristic use mode. It is operated at high output. In this operating state, the short-circuit flow of the exhaust gas has a two-stage expansion and throttling action by the first expansion chamber 11 and the third expansion chamber 13, and the non-short-circuit flow of the exhaust gas has a three-stage flow through the second expansion chamber 12. As a result, the exhaust noise level is greatly reduced as compared with exhaust gas that does not pass through the expansion chamber, and the generation of excessive exhaust noise is prevented.

【００３０】上記の例では、管体２４内に回転および摺
動自在に嵌合した筒状の弁体３２を、弁軸３３の操作端
部３４の回転および押引操作により駆動して管体２３の
閉鎖および連通状態の切替えをおこなうようにした切替
弁５１を用いたので、中間特性の使用態様時における中
間連通状態の弁体３２のセット（位置ぎめ）は、操作端
部３４による回転端位置あるいは押込終端位置として確
実容易にセットできるという長所を有するものである。In the above example, the tubular valve body 32 rotatably and slidably fitted in the tube 24 is driven by rotating and pushing / pulling the operating end 34 of the valve shaft 33. Since the switching valve 51 is used to close and switch the communication state of the valve 23, the set (positioning) of the valve body 32 in the intermediate communication state in the use mode of the intermediate characteristic is performed by the rotating end of the operating end 34. This has the advantage that it can be easily and reliably set as the position or the pushing end position.

【００３１】なお弁体３２に設ける穴５２を長穴とした
り、開口部２６に対応する別の穴を弁体３２に穿設する
などすれば、上記第２例とは摺動と回転の順序は異なる
が、同様な切替作用を有する回転・摺動型の切替弁を得
ることもできる。If the hole 52 provided in the valve body 32 is elongated, or another hole corresponding to the opening 26 is formed in the valve body 32, the order of sliding and rotation differs from that of the second example. However, a rotary / sliding type switching valve having a similar switching action can be obtained.

【００３２】また上記の回転・摺動型の切替弁のかわり
に、図１７に示す摺動型の切替弁５５や図１８〜図２０
に示す回転型の切替弁５６を用いることもできる。Instead of the above-mentioned rotary / sliding type switching valve, a sliding type switching valve 55 shown in FIG. 17 and FIGS.
Alternatively, a rotary switching valve 56 shown in FIG.

【００３３】すなわち図１７の切替弁５５は、前記第２
例よりも短尺の管体２４内に摺動自在に嵌合する弁体３
２の筒状部３２ａに、穴５２，５２を穿設してあり、図
１７に示す閉鎖状態から、弁軸３３の操作端部３４を引
出して、鎖線５７で示す位置まで弁体３２を矢印Ｘ方向
に摺動駆動すれば、穴５２が第２膨張室１２に開口し、
中間連通状態となる。さらに弁体３２を底板３２ｂが端
板５に当るまで摺動させれば、弁体３２の筒状部先端縁
５８が開口部２６を越えるので、開口部２６が開放され
て第３膨張室１３が管体２４を介して第１膨張室１１と
連通し、穴５２も第２膨張室１２に開口しているので、
短絡連通状態となり、この切替弁５５によれば、操作端
部３４の押引操作により、管体２４の閉鎖および連通状
態の切替えをおこなうことができる。That is, the switching valve 55 shown in FIG.
Valve body 3 slidably fitted in tube 24 shorter than the example
Holes 52, 52 are drilled in the second cylindrical portion 32a. The operating end 34 of the valve shaft 33 is pulled out from the closed state shown in FIG. If the slide drive is performed in the X direction, the hole 52 opens in the second expansion chamber 12,
An intermediate communication state is established. If the valve body 32 is further slid until the bottom plate 32b hits the end plate 5, the leading edge 58 of the tubular portion of the valve body 32 exceeds the opening 26, so that the opening 26 is opened and the third expansion chamber 13 is opened. Communicates with the first expansion chamber 11 via the pipe 24, and the hole 52 is also open to the second expansion chamber 12,
A short-circuit communication state is established, and according to the switching valve 55, the tube 24 can be closed and the communication state can be switched by the push / pull operation of the operation end portion.

【００３４】また図１８〜図２０の切替弁５６は、第２
例の管体２４に設ける開口部２５，２６は各１個ずつと
し、弁体３２の筒状部３２ａには２個の穴５２，５９を
図１９に示すように９０度位相をずらせて穿設するとと
もに、開口部２６に対応する位置にも、穴５９と同位相
位置に穴６０を１個穿設してある。The switching valve 56 shown in FIGS.
The opening 24, 26 provided in the tube 24 of the example is one each, and two holes 52, 59 are formed in the tubular portion 32a of the valve 32 with a phase shift of 90 degrees as shown in FIG. At the same time, one hole 60 is formed at a position corresponding to the opening 26 at the same phase position as the hole 59.

【００３５】図に示す閉鎖状態から、弁軸３３の操作端
部３４を矢印Ｒ方向に９０度回転させれば、穴５２が開
口部２５と連通して、第２膨張室１２が第１膨張室１１
と連通する中間連通状態となる。さらに操作端部３４を
同方向に９０度回転させれば、穴５９が開口部２５と、
穴６０が開口部２６と、それぞれ連通して短絡連通状態
となるので、この切替弁５６によれば、操作端部３４の
回転操作により、管体２４の閉鎖および連通状態の切替
えをおこなうことができるのである。When the operating end 34 of the valve shaft 33 is rotated by 90 degrees in the direction of arrow R from the closed state shown in the drawing, the hole 52 communicates with the opening 25, and the second expansion chamber 12 is in the first expansion state. Room 11
An intermediate communication state is established in which the communication is established. When the operation end 34 is further rotated by 90 degrees in the same direction, the hole 59 is
Since the hole 60 communicates with the opening 26 to be in a short-circuit communication state, the switching valve 56 can close the pipe 24 and switch the communication state by rotating the operation end 34. You can.

【００３６】次にこの発明の実施の形態の第３例（請求
項３記載の発明に対応）を、図２１により説明する。こ
の例の膨張型マフラ６１は、前記第２例における管体２
４を端板５の近傍位置まで延長したものであり、その他
の点は第２例と同構造を有する。Next, a third embodiment of the present invention (corresponding to the third aspect of the present invention) will be described with reference to FIG. The inflatable muffler 61 of this example is the same as the tubular body 2 of the second example.
4 is extended to a position near the end plate 5, and the other points have the same structure as the second example.

【００３７】そして図示の状態から前記第２例と同様に
操作端部３４を９０度時計方向に回転させた中間連通状
態においては、穴５２と開口部２５の連通により第２例
と同じ第１膨張室１１と第２膨張室１２の連通状態が得
られるが、操作端部３４を矢印Ｘ方向に引出した短絡連
通状態においては、弁体３２の穴５２は鎖線で示すよう
に管体２４内にあって管体２４により閉鎖されているの
で、第１膨張室１１が管体２４を介して第３膨張室１３
のみに連通した短絡連通状態が得られるのである。In the intermediate communication state in which the operating end 34 is rotated 90 degrees clockwise in the same manner as in the second example from the state shown in the figure, the communication between the hole 52 and the opening 25 allows the same first example as in the second example. A communication state between the expansion chamber 11 and the second expansion chamber 12 is obtained, but in a short-circuit communication state in which the operating end portion 34 is pulled out in the arrow X direction, the hole 52 of the valve body 32 is Is closed by the pipe 24, the first expansion chamber 11 is connected to the third expansion chamber 13 through the pipe 24.
Thus, a short-circuit communication state that is communicated only with the terminal is obtained.

【００３８】この例の膨張型マフラ６１は、上記のよう
に短絡連通状態において、第１膨張室１１と第２膨張室
１２の連通をなくし、より多くの排気ガスを積極的に第
３膨張室１３に導くことにより、前記第２例よりは高回
転運転時の出力が向上する。The expansion type muffler 61 of this embodiment eliminates the communication between the first expansion chamber 11 and the second expansion chamber 12 in the short-circuit communication state as described above, and actively increases the amount of exhaust gas to the third expansion chamber. By leading to 13, the output during high-speed operation is improved as compared with the second example.

【００３９】なお図１７の切替弁５５においても、管体
２４を上記と同様に端板５側に延長すれば、上記と同じ
短絡連通状態が得られる摺動型の切替弁が得られるし、
図１８〜図２０の切替弁５６における穴５９を省略すれ
ば、上記と同じ短絡連通状態が得られる回転型の切替弁
が得られる。Also in the switching valve 55 of FIG. 17, if the pipe 24 is extended toward the end plate 5 in the same manner as described above, a sliding type switching valve capable of obtaining the same short-circuit communication state as described above can be obtained.
If the hole 59 in the switching valve 56 of FIGS. 18 to 20 is omitted, a rotary switching valve that can achieve the same short-circuit communication state as described above is obtained.

【００４０】この発明は上記各例に限定されるものでは
なく、たとえば各部の具体的形状や構造、図１２におけ
る各連通管と管体の配置などは、上記以外のものとして
もよく、またロック装置３５は他形式のものとしてもよ
く、また弁軸の操作端部を電動駆動装置などにより駆動
する場合、該駆動装置あるいは駆動系統がロック機能を
有する場合は、弁軸部をロックするロック装置は省略し
てよい。またケーシング２は、外筒３を二重壁型とする
などしてもよく、管体の仕切板への取付は、かしめなど
によってもよい。The present invention is not limited to the above examples. For example, the specific shape and structure of each part, the arrangement of the communication pipes and pipes in FIG. 12 may be other than those described above. The device 35 may be of another type, and when the operating end of the valve shaft is driven by an electric drive device or the like, or when the drive device or the drive system has a lock function, a lock device for locking the valve shaft portion. May be omitted. In the casing 2, the outer cylinder 3 may be a double wall type, and the tubular body may be attached to the partition plate by caulking.

【００４１】また上記の例では管体２４と連通管８とは
別個に設けたが、たとえば弁体３２の底板３２ｂに常時
連通用の穴を穿孔して、管体２４（およびこの穴つきの
弁体３２）を連通管８として機能させ連通管８を省略す
ることも可能で、このように管体２４が連通管を兼用す
るケースも、この発明の実施の形態に含まれるものとす
る。In the above example, the pipe 24 and the communication pipe 8 are provided separately. However, for example, a hole for continuous communication is formed in the bottom plate 32b of the valve body 32 so that the pipe 24 (and the valve with this hole) is formed. The body 32) may function as the communication pipe 8, and the communication pipe 8 may be omitted. The case where the pipe body 24 also serves as the communication pipe is included in the embodiment of the present invention.

【００４２】[0042]

【発明の効果】以上説明したようにこの発明によれば、
膨張型マフラの入口側の第１膨張室と出口側の第３膨張
室を開閉弁または切替弁の操作により、管体を介して連
通できるようにしたので、この連通状態における排気抵
抗の低減化によりエンジン出力が向上し、簡潔な構造に
よって通常の低騒音の使用態様と、高出力の使用態様に
切替えられ、高出力の使用態様においても２段膨張によ
り過大排気音の発生が防止される。As described above, according to the present invention,
Since the first expansion chamber on the inlet side and the third expansion chamber on the outlet side of the expansion type muffler can be communicated via the pipe by operating the on-off valve or the switching valve, the exhaust resistance in this communication state can be reduced. As a result, the engine output is improved, and the usage mode is switched between a normal low-noise usage mode and a high-power usage mode by a simple structure. Even in a high-power usage mode, generation of excessive exhaust noise is prevented by two-stage expansion.

【００４３】また上記の効果に加えて、請求項２および
請求項３記載の発明によれば、切替弁の操作により、第
１膨張室が第２膨張室に連通する中間連通状態も得られ
るようにしたので、高出力の使用態様に比べて低騒音で
あり低騒音の使用態様に比べてエンジンの高出力が得ら
れる、中間特性の使用態様への切替えもおこなえ、走行
環境や所望の出力特性などに応じて３段階の使用態様が
選択でき、適応性に富む膨張型マフラが得られる。According to the second and third aspects of the present invention, in addition to the above-described effects, an intermediate communication state in which the first expansion chamber communicates with the second expansion chamber can be obtained by operating the switching valve. Therefore, it is possible to switch to the use mode of the intermediate characteristic, which is lower in noise than the use mode of the high output power and obtains a higher output of the engine than the use mode of the low noise. The use mode of the three stages can be selected according to the conditions, and the like, and an inflatable muffler with high flexibility can be obtained.

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

【図１】この発明の実施の形態の第１例を示す膨張型マ
フラの縦断面図である。FIG. 1 is a longitudinal sectional view of an inflatable muffler showing a first example of an embodiment of the present invention.

【図２】図１のＡ−Ａ線断面図である。FIG. 2 is a sectional view taken along line AA of FIG.

【図３】図１のＢ−Ｂ線断面図である。FIG. 3 is a sectional view taken along line BB of FIG. 1;

【図４】図１のＣ部拡大断面図である。FIG. 4 is an enlarged sectional view of a portion C in FIG. 1;

【図５】図４におけるコレットの斜視図である。FIG. 5 is a perspective view of the collet in FIG. 4;

【図６】図１における開閉弁の開動作状態を示す図１の
Ｄ部断面図である。6 is a sectional view of a portion D in FIG. 1 showing an opening operation state of the on-off valve in FIG. 1;

【図７】図１における開閉弁の他の実施態様を示す図１
のＤ部断面図である。7 shows another embodiment of the on-off valve in FIG. 1.
FIG.

【図８】図１における開閉弁のさらに他の実施態様を示
す図７相当図である。FIG. 8 is a diagram corresponding to FIG. 7, showing still another embodiment of the on-off valve in FIG. 1;

【図９】図８のＥ−Ｅ線断面図である。FIG. 9 is a sectional view taken along line EE of FIG. 8;

【図１０】この発明の実施の形態の第２例を示す膨張型
マフラの縦断面図である。FIG. 10 is a longitudinal sectional view of an inflatable muffler showing a second example of the embodiment of the present invention.

【図１１】図１０のＦ−Ｆ線断面図である。FIG. 11 is a sectional view taken along line FF of FIG. 10;

【図１２】図１０のＧ−Ｇ線断面図である。FIG. 12 is a sectional view taken along line GG of FIG. 10;

【図１３】図１０のＨ−Ｈ線断面図である。FIG. 13 is a sectional view taken along line HH of FIG. 10;

【図１４】図１０における管体２４部のＩ−Ｉ線断面図
である。FIG. 14 is a cross-sectional view taken along line II of a tube 24 in FIG.

【図１５】図１０における切替弁の動作状態（中間連通
状態）を示す図１０のＪ部断面図である。15 is a sectional view of a portion J in FIG. 10 showing an operation state (intermediate communication state) of the switching valve in FIG. 10;

【図１６】図１０における切替弁の動作状態（短絡連通
状態）を示す図１０のＪ部断面図である。FIG. 16 is a sectional view of a portion J in FIG. 10 showing an operation state (short-circuit communication state) of the switching valve in FIG. 10;

【図１７】図１０における切替弁の他の実施態様を示す
図１０のＪ部断面図である。17 is a sectional view of a portion J in FIG. 10 showing another embodiment of the switching valve in FIG. 10;

【図１８】図１０における切替弁のさらに他の実施態様
を示す図１０のＪ部断面図である。18 is a sectional view of a portion J in FIG. 10 showing still another embodiment of the switching valve in FIG. 10;

【図１９】図１８のＫ−Ｋ線断面図である。FIG. 19 is a sectional view taken along line KK of FIG. 18;

【図２０】図１８のＬ−Ｌ線断面図である。20 is a sectional view taken along line LL of FIG. 18;

【図２１】この発明の実施の形態の第３例を示す膨張型
マフラの縦断面図である。FIG. 21 is a longitudinal sectional view of an inflatable muffler showing a third embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１…膨張型マフラ、２…ケーシング、５…端板、６…仕
切板、７…仕切板、８…連通管、９…連通管、１１…第
１膨張室、１２…第２膨張室、１３…第３膨張室、１４
…入口管、１５…出口管、２１…管体、２２…開口部、
２３…管体、２４…管体、２５…開口部、２６…開口
部、３１…開閉弁、３２…弁体、３２ａ…筒状部、３２
ｂ…底板、３３…弁軸、３４…操作端部、３９…穴、４
１…開閉弁、４２…穴、４３…開閉弁、５０…膨張型マ
フラ、５１…切替弁、５２…穴、５５…切替弁、５６…
切替弁、５９…穴、６０…穴、６１…膨張型マフラ。DESCRIPTION OF SYMBOLS 1 ... Expansion type muffler, 2 ... Casing, 5 ... End plate, 6 ... Partition plate, 7 ... Partition plate, 8 ... Communication pipe, 9 ... Communication pipe, 11 ... 1st expansion chamber, 12 ... 2nd expansion chamber, 13 ... third expansion chamber, 14
... Inlet pipe, 15 ... Outlet pipe, 21 ... Tube, 22 ... Opening,
23 ... tube, 24 ... tube, 25 ... opening, 26 ... opening, 31 ... opening / closing valve, 32 ... valve, 32a ... tubular part, 32
b: bottom plate, 33: valve shaft, 34: operating end, 39: hole, 4
DESCRIPTION OF SYMBOLS 1 ... On-off valve, 42 ... Hole, 43 ... On-off valve, 50 ... Inflatable muffler, 51 ... Switching valve, 52 ... Hole, 55 ... Switching valve, 56 ...
Switching valve, 59 ... hole, 60 ... hole, 61 ... inflatable muffler.

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 ケーシング内を仕切板で仕切って、入口
管が接続された第１膨張室と、連通管により前記第１膨
張室と連通する第２膨張室と、連通管により前記第２膨
張室と連通し出口管が接続された第３膨張室とを設けた
膨張型マフラにおいて、前記第１膨張室と前記第３膨張
室とを連通する管体を前記仕切板に取付け、前記管体を
開閉する開閉弁を設けたことを特徴とする膨張型マフ
ラ。A first expansion chamber connected to an inlet pipe, a second expansion chamber connected to the first expansion chamber by a communication pipe, and a second expansion chamber connected to the first expansion chamber by a communication pipe. An inflatable muffler provided with a third expansion chamber communicating with a chamber and having an outlet pipe connected thereto, the pipe connecting the first expansion chamber and the third expansion chamber being attached to the partition plate; An inflatable muffler characterized by having an on-off valve for opening and closing the valve. 【請求項２】 ケーシング内を仕切板で仕切って、入口
管が接続された第１膨張室と、連通管により前記第１膨
張室と連通する第２膨張室と、連通管により前記第２膨
張室と連通し出口管が接続された第３膨張室とを設けた
膨張型マフラにおいて、一端部が前記第１膨張室に開口
し前記第２および第３膨張室内に延びて該第２および第
３膨張室に開口する開口部を有する管体を、前記仕切板
に取付け、前記各開口部を開閉して前記管体を閉鎖状態
から該管体を介して前記第１膨張室が前記第２膨張室に
連通する中間連通状態、および前記第１膨張室が前記第
２および第３膨張室に連通する短絡連通状態に切替える
切替弁を設けたことを特徴とする膨張型マフラ。2. The casing is partitioned by a partition plate, and a first expansion chamber to which an inlet pipe is connected, a second expansion chamber connected to the first expansion chamber by a communication pipe, and the second expansion chamber by a communication pipe. In an inflatable muffler provided with a chamber and a third expansion chamber connected to an outlet pipe, one end of the muffler is open to the first expansion chamber and extends into the second and third expansion chambers. (3) A pipe having an opening opening to the expansion chamber is attached to the partition plate, and each opening is opened and closed to close the pipe from the closed state, and the first expansion chamber is connected to the second expansion chamber via the pipe. An expansion type muffler comprising a switching valve for switching between an intermediate communication state communicating with the expansion chamber and a short-circuit communication state connecting the first expansion chamber to the second and third expansion chambers. 【請求項３】 ケーシング内を仕切板で仕切って、入口
管が接続された第１膨張室と、連通管により前記第１膨
張室と連通する第２膨張室と、連通管により前記第２膨
張室と連通し出口管が接続された第３膨張室とを設けた
膨張型マフラにおいて、一端部が前記第１膨張室に開口
し前記第２および第３膨張室内に延びて該第２および第
３膨張室に開口する開口部を有する管体を、前記仕切板
に取付け、前記各開口部を開閉して前記管体を閉鎖状態
から該管体を介して前記第１膨張室が前記第２膨張室に
連通する中間連通状態、および前記第１膨張室が前記第
３膨張室に連通する短絡連通状態に切替える切替弁を設
けたことを特徴とする膨張型マフラ。3. The casing is partitioned by a partition plate, a first expansion chamber connected to an inlet pipe, a second expansion chamber connected to the first expansion chamber by a communication pipe, and the second expansion chamber connected by a communication pipe. In an inflatable muffler provided with a chamber and a third expansion chamber connected to an outlet pipe, one end of the muffler is open to the first expansion chamber and extends into the second and third expansion chambers. (3) A pipe having an opening opening to the expansion chamber is attached to the partition plate, and each opening is opened and closed to close the pipe from the closed state, and the first expansion chamber is connected to the second expansion chamber via the pipe. An expansion type muffler comprising a switching valve for switching between an intermediate communication state communicating with the expansion chamber and a short-circuit communication state connecting the first expansion chamber to the third expansion chamber. 【請求項４】 前記切替弁が、前記管体内に回転および
／または摺動自在に嵌合し一端部が底板で閉鎖された筒
状の弁体と、前記底板に基部を固着され前記ケーシング
の端板を貫通して該端板の外側に操作端部を形成した弁
軸とから成り、この操作端部の回転および／または押引
操作により前記管体の閉鎖および連通状態の切替えをお
こなうようにした請求項２または３記載の膨張型マフ
ラ。4. The casing of the casing, wherein the switching valve is rotatably and / or slidably fitted in the pipe and one end of which is closed by a bottom plate, and a base fixed to the bottom plate. A valve shaft penetrating the end plate and having an operation end formed outside the end plate. The operation of the operation end is rotated and / or pushed / pulled to close the pipe and switch the communication state. The inflatable muffler according to claim 2 or 3, wherein