JPH0544490Y2 - - Google Patents
Info
- Publication number
- JPH0544490Y2 JPH0544490Y2 JP1988123504U JP12350488U JPH0544490Y2 JP H0544490 Y2 JPH0544490 Y2 JP H0544490Y2 JP 1988123504 U JP1988123504 U JP 1988123504U JP 12350488 U JP12350488 U JP 12350488U JP H0544490 Y2 JPH0544490 Y2 JP H0544490Y2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust
- muffler
- exhaust hole
- cylinder
- partition
- 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
- 230000030279 gene silencing Effects 0.000 claims description 4
- 238000005192 partition Methods 0.000 description 18
- 230000000694 effects Effects 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000000567 combustion gas Substances 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Exhaust Silencers (AREA)
Description
【考案の詳細な説明】
〔産業上の利用分野〕
本考案は2サイクルガソリンエンジンの排気装
置に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust system for a two-stroke gasoline engine.
第2図に従来の技術として実願昭62−121437に
示される2サイクルエンジンの排気装置の例を示
す。第2図において、1はクランクケース、2は
シリンダ、3はシリンダヘツド、4はクランク
軸、5はコネクテイングロツドである。燃焼室8
はシリンダ2、シリンダヘツド3及びピストン6
により形成される。ピストン6はクランク軸4の
回転によりシリンダ2に沿つて摺動する往復運動
をするが、シリンダ2のまわりにはピストン6の
外周によつて開閉する吸気孔21、排気孔23が
形成されている。排気孔23は、排気孔仕切り2
6により上部排気孔23aと下部排気孔23bに
分割されており、同様に、排気マフラ12もマフ
ラ仕切り27によりマフラ上部室12aとマフラ
下部室12bに区分されている。マフラ仕切り2
7の一部には、上部室12aと下部室12bを連
通する絞り28が設置されており、排気孔開口直
後の排気ガスは、上部排気孔23aからマフラ上
部室12aへ入り膨張する一方、絞り28を経て
マフラ下部室12bに入り、マフラ出口25より
大気へ放出される。絞り28の効果により、この
部分を通過する排気ガス量は抑制され、シリンダ
内の燃焼ガスは主に、上部排気孔23aに続いて
開口する下部排気孔23bからマフラ下部室12
bを経て大気に放出される。即ち燃焼ガスの流出
パターンを平準化し、又排気孔開口直後の高音圧
を絞り28とマフラ上部室12aにより減衰さ
せ、低騒音化を行つている。
FIG. 2 shows an example of a conventional exhaust system for a two-stroke engine disclosed in Japanese Utility Model Application No. 62-121437. In FIG. 2, 1 is a crankcase, 2 is a cylinder, 3 is a cylinder head, 4 is a crankshaft, and 5 is a connecting rod. Combustion chamber 8
are cylinder 2, cylinder head 3 and piston 6
formed by The piston 6 makes a reciprocating motion by sliding along the cylinder 2 due to the rotation of the crankshaft 4, and an intake hole 21 and an exhaust hole 23 are formed around the cylinder 2, which are opened and closed by the outer circumference of the piston 6. . The exhaust hole 23 is connected to the exhaust hole partition 2
Similarly, the exhaust muffler 12 is divided by a muffler partition 27 into an upper muffler chamber 12a and a lower muffler chamber 12b. Muffler partition 2
A throttle 28 is installed in a part of the muffler 7 to communicate the upper chamber 12a and the lower chamber 12b, and the exhaust gas immediately after opening the exhaust hole enters the muffler upper chamber 12a from the upper exhaust hole 23a and expands. 28, enters the muffler lower chamber 12b, and is discharged to the atmosphere from the muffler outlet 25. Due to the effect of the throttle 28, the amount of exhaust gas passing through this part is suppressed, and the combustion gas in the cylinder is mainly transferred to the muffler lower chamber 12 from the lower exhaust hole 23b that opens following the upper exhaust hole 23a.
It is released into the atmosphere through b. That is, the outflow pattern of the combustion gas is leveled, and the high sound pressure immediately after the opening of the exhaust hole is attenuated by the throttle 28 and the muffler upper chamber 12a, thereby reducing noise.
排気孔を上下に分ける仕切り26は、マフラの
仕切り27と一体でマフラ側から排気ポート内に
挿入して形成することもできるが、この場合は先
端部がピストンと接触しないように、又シリンダ
内面とできるだけ同心に設置する必要があるた
め、高い製作精度が要求される。しかしマフラ
は、一般に板金のプレスと溶接構造であるため
に、高精度の加工は困難である。
The partition 26 that divides the exhaust hole into upper and lower parts can be formed integrally with the muffler partition 27 and inserted into the exhaust port from the muffler side, but in this case, the tip should not come into contact with the piston, and the inner surface of the cylinder Since it is necessary to install it as concentrically as possible, high manufacturing precision is required. However, mufflers generally have a pressed and welded sheet metal structure, so it is difficult to process them with high precision.
従つて通常はシリンダ形成時に、この仕切り2
6をシリンダ2と一体に形成するが、通常シリン
ダ材はアルミ合金であり、仕切り26は薄い板状
で高温にさらされるため、耐熱性の面で問題が生
じる。この対策として、仕切り26の肉厚を厚く
することは、必然的に排気の開口タイミングを過
早にすることになり性能面で悪影響を及ぼすの
で、望ましくない。 Therefore, this partition 2 is usually used when forming the cylinder.
6 is formed integrally with the cylinder 2, but since the cylinder material is usually an aluminum alloy and the partition 26 is a thin plate and is exposed to high temperatures, a problem arises in terms of heat resistance. As a countermeasure to this problem, increasing the wall thickness of the partition 26 is not desirable because it inevitably causes the exhaust to open prematurely, which has an adverse effect on performance.
開口タイミングを変えた複数の排気孔をシリン
ダ壁に横に並べた形で形成させ、それぞれの排気
通路を独立にマフラに導き、マフラ内でも先に開
口する排気孔からの高圧排気を消音エレメント
(例えば絞りと空洞)を通した後、大気に排出、
又は後から開口する排気ポートからの排気ガス通
路に導く。
Multiple exhaust holes with different opening timings are formed side by side on the cylinder wall, each exhaust passage is led independently to the muffler, and high-pressure exhaust from the exhaust hole that opens first in the muffler is passed through a silencing element ( For example, after passing through the aperture and cavity), it is discharged into the atmosphere,
Or lead it to an exhaust gas passage from an exhaust port that opens later.
先に開口した排気室の高圧の排気ガスは絞り作
用受けて次に開口する排気室へ流れるので、マフ
ラ内の平滑した流れが得られる。横に並んだ排気
孔の間の仕切り部分の肉厚を開口タイミングに無
関係に適当な肉厚とすることができ、耐熱性が向
上する。
The high-pressure exhaust gas in the exhaust chamber that opens first is subjected to a throttling action and flows to the exhaust chamber that opens next, resulting in a smooth flow within the muffler. The wall thickness of the partition between the horizontally arranged exhaust holes can be set to an appropriate thickness regardless of the opening timing, and heat resistance is improved.
第1図に本考案による2サイクルエンジンの排
気装置の一例を示す。第1図は排気通路部で断面
した平面図である。排気孔とマフラの部分を除い
て第2図と同様である。排気孔33と34が仕切
り35で隔てられてシリンダ2に横に並んで形成
されており、排気孔34は排気孔33に比べて排
気孔の開くタイミングが遅くなつている。12は
マフラで、排気孔33,34に連通する様に取り
付けられているが、排気孔33,34の仕切り3
5に連続してマフラ側の仕切り27が設置されて
おり、排気孔33側のマフラ容積部12aと排気
孔34側のマフラ容積部12bが仕切られてい
る。このマフラ仕切り27には絞り28がマフラ
容積部12aと12bを連通して形成されてお
り、テールパイプ25はマフラ容積部12bに設
置されている。
FIG. 1 shows an example of an exhaust system for a two-stroke engine according to the present invention. FIG. 1 is a plan view taken in section at an exhaust passage section. It is the same as Fig. 2 except for the exhaust hole and muffler. Exhaust holes 33 and 34 are formed side by side in the cylinder 2, separated by a partition 35, and the exhaust hole 34 opens later than the exhaust hole 33. 12 is a muffler, which is installed so as to communicate with the exhaust holes 33 and 34;
A partition 27 on the muffler side is installed continuously from 5, and the muffler volume part 12a on the exhaust hole 33 side and the muffler volume part 12b on the exhaust hole 34 side are partitioned off. A throttle 28 is formed in the muffler partition 27 to communicate the muffler volumes 12a and 12b, and the tail pipe 25 is installed in the muffler volume 12b.
燃焼後ピストンが下降して排気孔33が開口し
た時、燃焼室内の高圧ガスはマフラ容積部12a
内に膨張し、一部は絞り28、マフラ容積部12
b、テールパイプ25を経て大気へ放出される
が、絞り28の効果によりその流量は抑制され
る。 When the piston descends after combustion and the exhaust hole 33 opens, the high pressure gas in the combustion chamber flows into the muffler volume 12a.
It expands inward, and a part of it expands into the throttle 28 and the muffler volume 12.
b. It is discharged into the atmosphere through the tail pipe 25, but its flow rate is suppressed by the effect of the throttle 28.
更にピストンが降下して排気孔34が開口した
とき、排気孔33の開口によりかなり膨張、減圧
した燃焼ガスは、排気孔34からマフラ容積部1
2b、テールパイプ25を経て大気へ放出され
る。即ち第2図の従来装置と同じ効果が得られ、
排気ガス流動の平準化と高圧排気音の抑制が行な
われ、排気騒音の低減が達成される。一方排気孔
に設けた仕切り壁35は比較的短かく(縦方向長
さ)、また肉厚を厚くすることも可能であるので、
熱的な問題は回避することができる。即ち、シリ
ンダの周方向に巾広く排気孔を形成すれば、排気
通過としての面積を確保することができるし、こ
の仕切り35はシリンダ壁の一部ともなつている
ので、ピストンリングのはみ出しによりリングが
折損することもなくなる。 When the piston further descends and the exhaust hole 34 opens, the combustion gas, which has been considerably expanded and decompressed due to the opening of the exhaust hole 33, flows from the exhaust hole 34 to the muffler volume 1.
2b, and is discharged to the atmosphere through the tail pipe 25. In other words, the same effect as the conventional device shown in FIG. 2 can be obtained,
The flow of exhaust gas is leveled and high-pressure exhaust noise is suppressed, thereby achieving a reduction in exhaust noise. On the other hand, the partition wall 35 provided at the exhaust hole is relatively short (vertical length) and can be made thick.
Thermal problems can be avoided. In other words, if the exhaust hole is formed wide in the circumferential direction of the cylinder, a sufficient area can be secured for the exhaust to pass through, and since this partition 35 is also a part of the cylinder wall, the piston ring protrudes from the ring. There will be no chance of it breaking.
ピストンのストロークによつてシリンダ側部に
設けた排気孔の開閉を行なう方式の2サイクルエ
ンジンにおいて、開孔タイミングの異なる複数の
排気孔をシリンダの周方向に並べて設け、各排気
孔をマフラ内のそれぞれの消音要素に連通させる
と共に各消音要素を絞りを介して連通させ、マフ
ラ内の各排気孔を流れるエンジン排気がそれぞれ
の消音要素を経た後、独立して或いは合流して排
出されるように構成したことにより、次の効果を
生ずる。
In a two-stroke engine that opens and closes the exhaust hole provided on the side of the cylinder according to the stroke of the piston, a plurality of exhaust holes with different opening timings are arranged in the circumferential direction of the cylinder, and each exhaust hole is connected to the inside of the muffler. The muffler communicates with each muffler element and communicates each muffler element through a throttle, so that the engine exhaust flowing through each exhaust hole in the muffler passes through each muffler element and is discharged independently or jointly. By configuring this, the following effects are produced.
(1) 簡単な構造の排気系により2サイクルエンジ
ンの排気音を抑制することができる。(1) The exhaust noise of a two-stroke engine can be suppressed by a simple exhaust system structure.
(2) 排気の流動を全体として確保することができ
るので、複雑な排気系や絞りを小さくした排気
系に比べ性能に対しても有利である。(2) Since the flow of the exhaust gas can be ensured as a whole, it is advantageous in terms of performance compared to a complicated exhaust system or an exhaust system with a small throttle.
(3) ポート仕切りを縦方向にすることで、仕切り
の熱的な問題を解消することが可能である。(3) By oriented the port partition vertically, it is possible to solve the thermal problem of the partition.
第1図は本考案による2サイクルエンジンの排
気装置の実施例を示し、aは排気孔位置における
水平断面図、bはa図のA視図で排気孔の配置を
示す。第2図は従来装置の全体縦断面図である。
2……シリンダ、8……燃焼室、12……マフ
ラ、12a,12b……マフラ容積部、25……
テールパイプ、27……マフラ仕切り壁、28…
…絞り、33,34……排気孔、35……排気孔
仕切り。
FIG. 1 shows an embodiment of the exhaust system for a two-stroke engine according to the present invention, in which a is a horizontal sectional view at the exhaust hole position, and b is a view from A in FIG. a, showing the arrangement of the exhaust holes. FIG. 2 is an overall vertical sectional view of the conventional device. 2... Cylinder, 8... Combustion chamber, 12... Muffler, 12a, 12b... Muffler volume part, 25...
Tail pipe, 27...Muffler partition wall, 28...
...Aperture, 33, 34...Exhaust hole, 35...Exhaust hole partition.
Claims (1)
設けた排気孔の開閉を行なう方式の2サイクルエ
ンジンにおいて、開孔タイミングの異なる複数の
排気孔をシリンダの周方向に並べて設け、各排気
孔をマフラ内のそれぞれの消音要素に連通させる
と共に各消音要素を絞りを介して連通させ、各排
気孔を流れるエンジン排気がそれぞれの消音要素
を経た後、独立して或いは合流して排出されるよ
うに構成したことを特徴とする2サイクルエンジ
ンの排気装置。 In a two-stroke engine that opens and closes the exhaust hole provided on the side of the cylinder according to the stroke of the piston, a plurality of exhaust holes with different opening timings are arranged in the circumferential direction of the cylinder, and each exhaust hole is connected to the inside of the muffler. The exhaust hole is configured to communicate with each of the silencing elements and communicate with each of the silencing elements via a throttle, so that engine exhaust gas flowing through each exhaust hole passes through each of the silencing elements and is discharged independently or in combination. An exhaust system for a two-stroke engine featuring:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1988123504U JPH0544490Y2 (en) | 1988-09-22 | 1988-09-22 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1988123504U JPH0544490Y2 (en) | 1988-09-22 | 1988-09-22 |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0246014U JPH0246014U (en) | 1990-03-29 |
JPH0544490Y2 true JPH0544490Y2 (en) | 1993-11-11 |
Family
ID=31372422
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1988123504U Expired - Lifetime JPH0544490Y2 (en) | 1988-09-22 | 1988-09-22 |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0544490Y2 (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3240194A (en) * | 1964-08-03 | 1966-03-15 | Outboard Marine Corp | Engine |
JPS614825A (en) * | 1984-06-19 | 1986-01-10 | Kawasaki Heavy Ind Ltd | Exhauster for 2-cycle engine |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60108723U (en) * | 1983-12-27 | 1985-07-24 | スズキ株式会社 | 2 cycle engine exhaust system |
JPS61108815U (en) * | 1984-12-24 | 1986-07-10 |
-
1988
- 1988-09-22 JP JP1988123504U patent/JPH0544490Y2/ja not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3240194A (en) * | 1964-08-03 | 1966-03-15 | Outboard Marine Corp | Engine |
JPS614825A (en) * | 1984-06-19 | 1986-01-10 | Kawasaki Heavy Ind Ltd | Exhauster for 2-cycle engine |
Also Published As
Publication number | Publication date |
---|---|
JPH0246014U (en) | 1990-03-29 |
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