JPH0830408B2 - Exhaust pipe of a two-cycle engine for motorcycles - Google Patents
Exhaust pipe of a two-cycle engine for motorcyclesInfo
- Publication number
- JPH0830408B2 JPH0830408B2 JP22884686A JP22884686A JPH0830408B2 JP H0830408 B2 JPH0830408 B2 JP H0830408B2 JP 22884686 A JP22884686 A JP 22884686A JP 22884686 A JP22884686 A JP 22884686A JP H0830408 B2 JPH0830408 B2 JP H0830408B2
- Authority
- JP
- Japan
- Prior art keywords
- vehicle body
- exhaust pipe
- diameter
- exhaust
- cycle engine
- 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 - Fee Related
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
Landscapes
- Exhaust Silencers (AREA)
- Characterised By The Charging Evacuation (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） この発明は、２サイクルエンジンの排気の脈動効果に
悪影響を与えないようにした自動二輪車用２サイクルエ
ンジンの排気管に関する。Description: TECHNICAL FIELD The present invention relates to an exhaust pipe of a two-cycle engine for a motorcycle that does not adversely affect the pulsating effect of exhaust gas of the two-cycle engine.
（従来の技術） 一般に、自動二輪車では、エンジンの排気ポートに連
なる排気管を設けている。上記エンジンが２サイクル型
の場合、排気の脈動効果を有効利用してこのエンジンの
出力を向上させるため、排気管にはその中途部に膨張室
が形成される。(Prior Art) Generally, a motorcycle has an exhaust pipe connected to an exhaust port of an engine. When the engine is a two-cycle type, an expansion chamber is formed in the middle of the exhaust pipe in order to improve the output of the engine by effectively utilizing the pulsating effect of exhaust gas.
上記の場合、膨張室は排気ポート側から車体後方（以
下、これを単に後方と言い、これと反対方向を前方とい
う）へ向って進むに従い漸次径大となる膨張部と、この
膨張部の後端に接続され後方へ向ってほぼ同径で延びる
同径部と、この同径部の後端に接続され後方へ向って進
むに従い漸次径小となる絞り部とで構成されている。In the above case, the expansion chamber gradually increases in diameter as it goes from the exhaust port side toward the rear of the vehicle body (hereinafter, simply referred to as the rear, and the opposite direction is referred to as the front). The same-diameter portion is connected to the end and extends rearward with substantially the same diameter, and the throttle portion is connected to the rear end of the same-diameter portion and gradually decreases in diameter toward the rear.
そして、排気ポートからの排気圧力波はこの膨張室で
一旦膨張した後、絞り部で反射して排気ポートに戻るよ
うになっている。The exhaust pressure wave from the exhaust port is once expanded in this expansion chamber, then reflected by the throttle portion and returned to the exhaust port.
（発明が解決しようとする問題点） ところで、自動二輪車では排気管後端の消音器を車体
側部に位置させる必要上、この排気管の中途部を折り曲
げている。この場合、上記排気管の中途部に単に折り曲
げると、この折り曲げ部で排気ポートからの排気圧力波
が反射して排気ガスの脈動効果に悪影響を与え、エンジ
ンの出力低下を招くという不都合を生じる。(Problems to be Solved by the Invention) By the way, in a motorcycle, the middle part of the exhaust pipe is bent because the muffler at the rear end of the exhaust pipe needs to be located on the side of the vehicle body. In this case, if it is simply bent in the middle of the exhaust pipe, an exhaust pressure wave from the exhaust port is reflected at this bent portion to adversely affect the pulsating effect of the exhaust gas, resulting in a decrease in engine output.
（発明の目的） この発明は、上記のような事情に注目してなされたも
ので、２サイクルエンジンにおける排気管の中途部を折
り曲げる場合、排気の脈動効果に悪影響を与えないよう
にすることを目的とする。(Object of the Invention) The present invention has been made by paying attention to the above circumstances, and when bending the middle part of the exhaust pipe in a two-cycle engine, it is necessary to prevent the pulsating effect of the exhaust from being adversely affected. To aim.
（発明の構成） 上記目的を達成するためのこの発明の特徴とするとこ
ろは、自動二輪車用２サイクルエンジンの排気管におい
て、この排気管の膨張室の上流側を構成する膨張部を車
幅方向ほぼ中央で車体の前後方向に沿って延びるように
配置し、同上排気管の下流側を構成する絞り部が車体の
外側部に位置するように同上排気管の中途部における同
径部を車幅方向外方に向って折り曲げた点にある。(Structure of the Invention) A feature of the present invention for achieving the above-mentioned object is that in an exhaust pipe of a two-cycle engine for a motorcycle, an expansion portion constituting an upstream side of an expansion chamber of the exhaust pipe is formed in a vehicle width direction. It is arranged so as to extend along the front-rear direction of the vehicle body at approximately the center, and the same diameter part in the middle part of the exhaust pipe is placed so that the throttle part that constitutes the downstream side of the exhaust pipe is located outside the vehicle body. It is located at a point that is bent outward.
（実施例） 以下、この発明の実施例を図面により説明する。Embodiment An embodiment of the present invention will be described below with reference to the drawings.
第２図において、１は自動二輪車で、その車体フレー
ム２の前部に操向軸管３が設けられ、この操向軸管３は
その軸心回り回動自在にフロントフォーク４を支承して
いる。そして、このフロントフォーク４の下端が前輪５
を支持し、上端にはハンドル６が取り付けられる。In FIG. 2, reference numeral 1 is a motorcycle, and a steering shaft tube 3 is provided at a front portion of a body frame 2 thereof, and the steering shaft tube 3 supports a front fork 4 rotatably around its axis. There is. The lower end of the front fork 4 is the front wheel 5.
And a handle 6 is attached to the upper end.
また、上記車体フレーム２は操向軸管３から後下方に
向って延びる左右一対の主フレーム８と、これら両主フ
レーム８の前端と後端とを結び下方に向って湾曲する左
右一対のダウンチューブ９を有している。The body frame 2 includes a pair of left and right main frames 8 extending rearward and downward from the steering shaft tube 3, and a pair of left and right down frames that connect the front and rear ends of the main frames 8 and are curved downward. It has a tube 9.
上記主フレーム８後端とダウンチューブ９後端との連
結部には、リヤアーム10が枢支軸11により上下揺動自在
に枢支され、このリヤアーム10の揺動端には後輪12が支
持される。また、上記左右主フレーム８と左右ダウンチ
ューブ９との間の枠内にエンジン14が支持され、このエ
ンジン14が上記後輪12を駆動する。即ち、エンジン14の
左側部にはこのエンジン14により駆動する駆動鎖車15が
連結される。一方、上記後輪12の左側部にはこの後輪12
と共に回転する従動鎖車16が設けられ、これら両鎖車1
5,16に伝動チェーン17を巻き掛けてある。そして、エン
ジン14を駆動すれば、伝動チェーン17を介して後輪12が
回転駆動し、自動二輪車１が走行する。A rear arm 10 is pivotally supported by a pivot shaft 11 at a connecting portion between the rear end of the main frame 8 and the rear end of the down tube 9, and a rear wheel 12 is supported on the swing end of the rear arm 10. To be done. An engine 14 is supported in the frame between the left and right main frames 8 and the left and right down tubes 9, and the engine 14 drives the rear wheels 12. That is, a drive chain 15 driven by the engine 14 is connected to the left side of the engine 14. On the other hand, on the left side of the rear wheel 12, the rear wheel 12
A driven chain wheel 16 that rotates together with the chain wheel 1 is provided.
The transmission chain 17 is wound around 5,16. Then, when the engine 14 is driven, the rear wheels 12 are rotationally driven via the transmission chain 17, and the motorcycle 1 runs.
また、上記エンジン14の上方で左右主フレーム８上に
は燃料タンク19が設けられ、この燃料タンク19の後方に
はシート20が配置されている。このシート20上のライダ
ーがその足を乗せる左右一対のフートレスト21が設けら
れる。即ち、上記主フレーム８後端とダウンチューブ９
後端との連結部に後方へ向って左右一対のブラケット板
22が突設される。そして、これら両ブラケット板22の突
出端側に上記フートレスト21を取り付けてある。A fuel tank 19 is provided above the engine 14 on the left and right main frames 8, and a seat 20 is arranged behind the fuel tank 19. A pair of left and right footrests 21 on which the rider on the seat 20 rests his foot are provided. That is, the rear end of the main frame 8 and the down tube 9
A pair of left and right bracket plates facing rearward at the connection with the rear end
22 is projected. The footrest 21 is attached to the protruding end sides of both bracket plates 22.
上記エンジン14は２サイクル単気筒型であって、クラ
ンクケース24と、このクランクケース24から前上方に向
って突出するシリンダ25とを有している。このシリンダ
25の前部に排気ポートを形成してあり、この排気ポート
からシリンダ25の排気ガスを外部に排出させる排気管27
が設けられる。The engine 14 is a two-cycle single cylinder type, and has a crankcase 24 and a cylinder 25 protruding from the crankcase 24 toward the front upper side. This cylinder
An exhaust port is formed in the front part of 25, and an exhaust pipe 27 for exhausting the exhaust gas of the cylinder 25 to the outside from this exhaust port.
Is provided.
上記排気管27は上記排気ポートに連なる膨張室28と、
この膨張室28の後端に接続される消音器29とで構成して
ある。また、この消音器29が車体の右側に位置するよう
に、上記膨張室28の中途部を折り曲げてある。The exhaust pipe 27 is an expansion chamber 28 connected to the exhaust port,
The silencer 29 is connected to the rear end of the expansion chamber 28. Further, the middle part of the expansion chamber 28 is bent so that the silencer 29 is located on the right side of the vehicle body.
全図により、上記膨張室28について詳しく説明する。 The expansion chamber 28 will be described in detail with reference to all drawings.
上記膨張室28は、同上排気ポートから前下方へ向って
突出しこの突出端が後方へ向って折り曲げられる接続部
31と、この接続部31の後端に接続され後方へ進むに従い
漸次径大となる膨張部32と、この膨張部32の後端に接続
され後方へ向ってほぼ同径で延びる同径部33と、この同
径部33の後端に接続され後方へ向って進むに従い漸次径
小となる絞り部34とで構成され、この絞り部34の後端に
上記消音器29を接続している。The expansion chamber 28 is the same as the above, and is a connecting portion in which the exhaust port projects forward and downward and the projecting end is bent rearward.
31, an inflating portion 32 connected to the rear end of the connecting portion 31 and gradually increasing in diameter as it goes rearward, and an equal diameter portion 33 connected to the rear end of the inflating portion 32 and extending rearward with substantially the same diameter 33. And a throttle portion 34 connected to the rear end of the same diameter portion 33 and gradually decreasing in diameter toward the rear, and the silencer 29 is connected to the rear end of the throttle portion 34.
上記膨張部32は車幅方向ほぼ中央部でクランクケース
24の下方に配置され、上下方向で少しずつ折れ曲がりな
がら車体前後方向に沿って延びている。また、この膨張
部32の後部は後上方へ向って折り曲げられている。一
方、上記同径部33は多重管構造をなしており、所定間隔
をあけて嵌合する外筒36と内筒37とを有している。この
内筒37には多数の貫通孔37aが形成され上記外筒36と内
筒37との間にはグラスウール38を充填している。また、
車体の左外側部に位置する伝動チェーン17と絞り部34と
の干渉を回避させるため、上記絞り部34を車体の右外側
部に位置させるように、同上同径部33の中途部は車幅方
向右外方へ向って折り曲げられている。The inflatable portion 32 is located in the crankcase at the substantially central portion in the vehicle width direction.
It is located below 24 and extends along the front-rear direction of the vehicle body while bending little by little in the vertical direction. Further, the rear part of the inflating part 32 is bent rearward and upward. On the other hand, the same-diameter portion 33 has a multi-tube structure, and has an outer cylinder 36 and an inner cylinder 37 that are fitted at a predetermined interval. A large number of through holes 37a are formed in the inner cylinder 37, and glass wool 38 is filled between the outer cylinder 36 and the inner cylinder 37. Also,
In order to avoid interference between the transmission chain 17 located on the left outer side of the vehicle body and the throttle portion 34, the throttle portion 34 is positioned on the right outer side portion of the vehicle body. It is bent outward in the right direction.
上記の場合、膨張室28の前部が車幅方向ほぼ中央に位
置し、かつ、同上消音器29がフートレスト21よりも上位
に位置するように上記膨張室28の後部が折り曲げられて
いるため、この自動二輪車１におけるバンク角を左右ほ
ぼ均等に大きく取ることができる。In the above case, the front portion of the expansion chamber 28 is located substantially in the center in the vehicle width direction, and the same as above, since the rear portion of the expansion chamber 28 is bent so that the silencer 29 is positioned higher than the footrest 21, The bank angle of the motorcycle 1 can be made large evenly on the left and right.
上記膨張室28を車体フレーム２に支持させるため、絞
り部34にはブラケット40が突設されている。このブラケ
ット40は車体前後方向に延びる板材で、その下端が絞り
部34の上面に取り付けられ、このブラケット40の上端は
右側フートレスト21用のブラケット板22にねじ止めして
ある。この場合、上記ブラケット40は膨張室28の上方に
位置し、かつ、車体前後方向に延びる板材であるため、
フートレスト21用のブラケット板22に対するねじ止め作
業は車体外側方からできるのであり、よって、このねじ
止め作業は容易にすることができる。In order to support the expansion chamber 28 on the vehicle body frame 2, a bracket 40 is projectingly provided on the throttle portion 34. The bracket 40 is a plate member extending in the front-rear direction of the vehicle body, the lower end of which is attached to the upper surface of the narrowed portion 34, and the upper end of the bracket 40 is screwed to the bracket plate 22 for the right footrest 21. In this case, since the bracket 40 is a plate member located above the expansion chamber 28 and extending in the vehicle front-rear direction,
Since the screwing work for the bracket plate 22 for the footrest 21 can be performed from the outside of the vehicle body, this screwing work can be facilitated.
（発明の効果） この発明による効果は次の如くである。即ち、自動二
輪車用２サイクルエンジンの排気管において、このエン
ジンの排気の脈動効果を有効利用するための膨張室がエ
ンジンの排気ポート側から車体後方へ向って進むに従い
漸次径大となる膨張部と、この膨張部の後端に接続され
車体後方へ向ってほぼ同径で延びる同径部と、この同径
部の後端に接続され車体後方へ向って進むに従い漸次径
小となる絞り部とで構成された場合、排気圧力波は膨張
部で膨張して同径部から絞り部への流動し、この絞り部
で反射波となって所望の脈動効果を生じる。このような
膨張室の後部を車体側部に位置させようとすると、この
膨張室の中途部を折り曲げる必要が生じる。そこで、こ
の発明では、膨張部を車幅方向ほぼ中央で車体の前後方
向に沿って延びるように配置し、絞り部が車体の外側部
に位置するように同径部を車幅方向外方に向って折り曲
げてある。即ち、径寸法がほぼ一定で上記反射波を生じ
ないところで膨張室を折り曲げたため、このように膨張
室を折り曲げた場合でも、この膨張室における所望の脈
動効果に悪影響を与えることはなく、よって、エンジン
の良好な出力が維持される。(Effects of the Invention) The effects of the present invention are as follows. That is, in the exhaust pipe of a two-cycle engine for a motorcycle, an expansion chamber for effectively utilizing the pulsating effect of the exhaust gas of the engine is gradually increased in diameter as it goes from the exhaust port side of the engine toward the rear of the vehicle body. , A same-diameter portion connected to the rear end of the expansion portion and extending to the rear of the vehicle body with substantially the same diameter, and a throttle portion connected to the rear end of the same-diameter portion and gradually decreasing in diameter toward the rear of the vehicle body. In this case, the exhaust pressure wave expands in the expansion section and flows from the same diameter section to the throttle section, and becomes a reflected wave in this throttle section to produce a desired pulsating effect. If the rear portion of such an expansion chamber is to be positioned on the side of the vehicle body, it is necessary to bend the middle portion of the expansion chamber. Therefore, in the present invention, the inflating portion is arranged so as to extend along the front-rear direction of the vehicle body substantially at the center in the vehicle width direction, and the same diameter portion is disposed outward in the vehicle width direction so that the throttle portion is located on the outer side portion of the vehicle body. It's bent over. That is, since the expansion chamber is bent at a location where the reflected wave is not generated with the diameter dimension being substantially constant, even when the expansion chamber is bent in this manner, the desired pulsating effect in the expansion chamber is not adversely affected, and therefore, Good engine output is maintained.
図はこの発明の実施例を示し、第１図は第２図のＩ−Ｉ
線矢視概略平面図、第２図は自動二輪車の全体側面部分
切欠図、第３図は排気管の側面断面図、第４図は第２図
のIV−IV線矢視断面図、第５図は第３図のＶ−Ｖ線矢視
断面図である。 １…自動二輪車、14…エンジン、27…排気管、28…膨張
室、32…膨張部、33…同径部、34…絞り部。FIG. 1 shows an embodiment of the present invention, and FIG. 1 shows I-I of FIG.
Fig. 2 is a schematic plan view taken along the arrow, Fig. 2 is a partial side cutaway view of the motorcycle, Fig. 3 is a side cross-sectional view of the exhaust pipe, and Fig. 4 is a cross-sectional view taken along the line IV-IV in Fig. 2; The figure is a sectional view taken along the line VV of FIG. DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 14 ... Engine, 27 ... Exhaust pipe, 28 ... Expansion chamber, 32 ... Expansion part, 33 ... Same diameter part, 34 ... Throttling part.
Claims (1)
排気管の膨張室を上記排気ポート側から車体後方へ向っ
て進むに従い漸次径大となる膨張部と、この膨張部の後
端に接続され車体後方へ向ってほぼ同径で延びる同径部
と、この同径部の後端に接続され車体後方へ向って進む
に従い漸次径小となる絞り部とで構成した自動二輪車用
２サイクルエンジンの排気管において、上記膨張部を車
幅方向ほぼ中央で車体の前後方向に沿って延びるように
配置し、絞り部が車体の外側部に位置するように同径部
を車幅方向外方に向って折り曲げたことを特徴とする自
動二輪車用２サイクルエンジンの排気管。Claim: What is claimed is: 1. An expansion section of an exhaust pipe connected to an exhaust port of a two-cycle engine, the expansion section gradually increasing in diameter toward the rear of the vehicle body from the exhaust port side, and a vehicle body connected to the rear end of the expansion section. Exhaust of a two-cycle engine for a motorcycle, which is composed of a same-diameter portion extending rearward with substantially the same diameter and a throttle portion connected to the rear end of the same-diameter portion and gradually decreasing in diameter toward the rear of the vehicle body. In the pipe, the inflating portion is arranged so as to extend along the front-rear direction of the vehicle body at substantially the center in the vehicle width direction, and the same diameter portion is directed outward in the vehicle width direction so that the throttle portion is located on the outer side portion of the vehicle body. Exhaust pipe for a two-cycle engine for motorcycles that is bent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22884686A JPH0830408B2 (en) | 1986-09-26 | 1986-09-26 | Exhaust pipe of a two-cycle engine for motorcycles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22884686A JPH0830408B2 (en) | 1986-09-26 | 1986-09-26 | Exhaust pipe of a two-cycle engine for motorcycles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6385212A JPS6385212A (en) | 1988-04-15 |
| JPH0830408B2 true JPH0830408B2 (en) | 1996-03-27 |
Family
ID=16882784
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22884686A Expired - Fee Related JPH0830408B2 (en) | 1986-09-26 | 1986-09-26 | Exhaust pipe of a two-cycle engine for motorcycles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0830408B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH088957Y2 (en) * | 1988-11-30 | 1996-03-13 | 本田技研工業株式会社 | Exhaust system device for motorcycles |
| JP6306659B1 (en) | 2016-10-19 | 2018-04-04 | ファナック株式会社 | Beam distributor |
-
1986
- 1986-09-26 JP JP22884686A patent/JPH0830408B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6385212A (en) | 1988-04-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |