JPH0514089B2 - - Google Patents

Info

Publication number
JPH0514089B2
JPH0514089B2 JP57214993A JP21499382A JPH0514089B2 JP H0514089 B2 JPH0514089 B2 JP H0514089B2 JP 57214993 A JP57214993 A JP 57214993A JP 21499382 A JP21499382 A JP 21499382A JP H0514089 B2 JPH0514089 B2 JP H0514089B2
Authority
JP
Japan
Prior art keywords
valve body
exhaust port
exhaust
partition wall
exhaust passage
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
Application number
JP57214993A
Other languages
Japanese (ja)
Other versions
JPS59105928A (en
Inventor
Toshiharu Minami
Toshimitsu Iio
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yamaha Motor Co Ltd
Original Assignee
Yamaha Motor Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Yamaha Motor Co Ltd filed Critical Yamaha Motor Co Ltd
Priority to JP57214993A priority Critical patent/JPS59105928A/en
Publication of JPS59105928A publication Critical patent/JPS59105928A/en
Publication of JPH0514089B2 publication Critical patent/JPH0514089B2/ja
Granted legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F02D13/028—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation for two-stroke engines
    • F02D13/0284—Variable control of exhaust valves only
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Description

【発明の詳細な説明】 この発明はシリンダに形成した排気口の上縁を
略鼓形の弁体によつて形成し、エンジンの運転状
態に応じて排気口の上縁を昇降させ、排気口の開
口時期を調節できるようにした二行程エンジンに
関するもので、排気口から前記弁体の下流側に至
る排気通路を隔壁によつて左右に二分し、排気口
の開口面積を大きくしてその制御域の拡大を図る
と共に、その際、ピストンリングが拡大された排
気口に引つ掛かつて損傷することがないように排
気口の略中央部に縦方向の隔壁を構成した点に特
徴がある。Detailed Description of the Invention This invention forms the upper edge of the exhaust port formed in the cylinder with a substantially drum-shaped valve body, and raises and lowers the upper edge of the exhaust port depending on the operating condition of the engine. This relates to a two-stroke engine in which the opening timing of the exhaust port can be adjusted, and the exhaust passage from the exhaust port to the downstream side of the valve body is divided into left and right by a partition wall, and the opening area of the exhaust port is increased to control the exhaust passage. In addition to expanding the area, the piston ring is characterized in that a vertical partition wall is formed approximately in the center of the exhaust port to prevent the piston ring from getting caught in the expanded exhaust port and being damaged.

従来、二行程エンジンを効率よく運転する技術
としてシリンダに排気口の上縁を形成する弁体を
設け、エンジンの高出力時にその上縁を上昇させ
ることによつてエンジン性能を向上させる技術が
知られている（例えば実開昭54−9221号公報）。 Conventionally, as a technique for efficiently operating a two-stroke engine, a technique has been known in which a valve body is provided in the cylinder to form the upper edge of the exhaust port, and the upper edge is raised when the engine outputs high, thereby improving engine performance. (For example, Japanese Utility Model Application Publication No. 1983-9221).

他方、二行程エンジンでは燃焼室に対する混合
気の供給および既燃ガスの排出はシリンダ壁に開
口させた吸気口あるいは排気口を通じて行われて
おり、それらの開口位置によつて吸排気のタイミ
ングが定まる。 On the other hand, in a two-stroke engine, the air-fuel mixture is supplied to the combustion chamber and the burned gas is discharged through intake or exhaust ports opened in the cylinder wall, and the timing of intake and exhaust is determined by the position of these openings. .

ところで、排気口は既燃ガスの掃気が充分に行
われる限り、低い位置に開口させる方が、膨張行
程が長くなり、熱効率向上に有利である。前記排
気口をなす弁体の上縁を可及的に下方で降下させ
るように設定するのが好ましい。 Incidentally, as long as burnt gas is sufficiently scavenged, opening the exhaust port at a lower position lengthens the expansion stroke and is advantageous for improving thermal efficiency. It is preferable to set the upper edge of the valve body forming the exhaust port to be lowered as far as possible.

然しながら、膨張行程を長くすると掃気が不充
分になるので、通常排気口の開口幅を広げ、掃気
能率を高めることが必要になる。この場合、ピス
トンリングが排気口に引つ掛かるのを防止するた
め排気口の中央に縦リブを設ける技術（例えば実
開昭48−41911号公報）を採用するのが普通であ
るが、上記エンジンでは排気口に前記弁体が存在
するので、縦リブの形成が容易ではない。 However, if the expansion stroke is lengthened, the scavenging air becomes insufficient, so it is usually necessary to widen the opening width of the exhaust port to improve the scavenging efficiency. In this case, it is common practice to adopt a technique in which a vertical rib is provided in the center of the exhaust port to prevent the piston ring from getting caught in the exhaust port (for example, Japanese Utility Model Application Publication No. 48-41911). Since the valve body is present at the exhaust port, it is not easy to form the vertical ribs.

この発明はこのような不具合を除去することを
目的とするものである。以下、これを図示の実施
例によつて説明する。図中、１は燃焼室であり、
シリンダ２、シリンダヘツド３及びピストン４に
よつて形成され、それらはクランク室５によつて
支持されている。６は点火栓、７は主掃気口７ａ
と補助掃気口７ｂとからなる掃気口である。８は
排気通路であり、シリンダ２の壁面に開口した排
気口８ａから導かれる。 The present invention aims to eliminate such problems. This will be explained below using illustrated embodiments. In the figure, 1 is the combustion chamber,
It is formed by a cylinder 2, a cylinder head 3 and a piston 4, which are supported by a crank chamber 5. 6 is a spark plug, 7 is a main scavenging port 7a
This is a scavenging port consisting of an auxiliary scavenging port 7b and an auxiliary scavenging port 7b. Reference numeral 8 denotes an exhaust passage, which is led from an exhaust port 8a opened in the wall surface of the cylinder 2.

排気通路８の上面の排気口８ａに近接した部分
には、シリンダ２とシリンダ２の排気側側面に着
脱自在に取付けられた蓋部材２ａとの間に、略鼓
形に形成された弁体収容凹所を設け、そこに排気
口８ａの上縁を形成する弁体９が回動自在に支持
されている。弁体９は外周が略鼓形をなし、その
外周の一部が切り取られて排気通路８が形成され
ている。弁体９の切り取られた部分に残つた縁部
９ａは排気口８ａの上縁を形成し、エンジンの運
転状態に応じ、速度や出力の大きい時に上昇さ
せ、小さい時に下降させて、排気口８ａの開口時
期を早めたり、遅めたり出来るようにしてある。
なお、１１はシリンダ２に形成された吸気口、１
２はクランク軸である。 In a portion of the upper surface of the exhaust passage 8 close to the exhaust port 8a, a valve body formed in a substantially drum shape is housed between the cylinder 2 and a lid member 2a detachably attached to the exhaust side side surface of the cylinder 2. A recess is provided in which a valve body 9 forming the upper edge of the exhaust port 8a is rotatably supported. The outer periphery of the valve body 9 is approximately drum-shaped, and a portion of the outer periphery is cut off to form the exhaust passage 8. The edge 9a remaining on the cut out part of the valve body 9 forms the upper edge of the exhaust port 8a, and depending on the operating state of the engine, it is raised when the speed and output are high, and lowered when it is low. The opening time can be advanced or delayed.
Note that 11 is an intake port formed in the cylinder 2;
2 is a crankshaft.

１５は排気口８ａから前記弁体９の下流側に至
る排気通路８を左右に区画する縦方向の隔壁であ
り、隔壁１５には前記弁体９の鼓形外周の最小径
よりやゝ細い挿通孔１６を設け、弁体９の外周に
形成した溝９ｂを係合させ、弁体９が左右方向へ
移動するのを阻止している。 Reference numeral 15 denotes a vertical partition wall that partitions the exhaust passage 8 from the exhaust port 8a to the downstream side of the valve body 9 to the left and right. A hole 16 is provided and engaged with a groove 9b formed on the outer periphery of the valve body 9 to prevent the valve body 9 from moving in the left-right direction.

次に実施例の動作を説明する。エンジンが始動
し、低負荷で運転されるとき前記弁体９の縁部９
ａは排気通路８に大きく進出している。エンジン
の膨張行程において、ピストン４が排気口８ａに
至るとシリンダ２内の既燃ガス急速に排気通路８
内へ排出させ、次いで、上昇行程に転ずると、ま
ず掃気口７を閉じ、続いて排気口８ａを閉じて圧
縮行程が開始する。 Next, the operation of the embodiment will be explained. When the engine is started and operated at low load, the edge 9 of the valve body 9
A extends largely into the exhaust passage 8. During the expansion stroke of the engine, when the piston 4 reaches the exhaust port 8a, the burned gas in the cylinder 2 rapidly flows into the exhaust passage 8a.
When the exhaust gas is discharged into the interior, and then the ascending stroke begins, the scavenging port 7 is first closed, and then the exhaust port 8a is closed, and the compression stroke begins.

ここで、弁体９の縁部９ａはエンジンが高出力
又は高速で運転されるときは手動操作あるいは自
動的操作により上昇して、排気口８ａの開口時期
を早め、エンジンの特性を高速形に設定する。ま
た、エンジンが低出力又は低速で運転されるとき
は弁体９の縁部９ａが排気通路８内へ進出し、排
気口８ａの上縁を降下させ、エンジンの特性を低
速形とする。 Here, when the engine is operated at high output or high speed, the edge 9a of the valve body 9 is raised by manual or automatic operation to advance the opening timing of the exhaust port 8a and change the characteristics of the engine to a high speed type. Set. Further, when the engine is operated at low output or low speed, the edge 9a of the valve body 9 advances into the exhaust passage 8, lowering the upper edge of the exhaust port 8a, and making the engine characteristic low-speed.

排気口８ａから排出された既燃ガスは隔壁１５
を熱するが、隔壁１５は排気通路８の上下に連結
されており、シリンダ２へ放熱されるので隔壁１
５の冷却がよく、薄肉に形成しても過熱しない。
よつて既燃ガスの流出の妨げとなることもない。
また、弁体９の外周部は隔壁１５と摺接している
のでシリンダ２への放熱の妨げとなるばかりでな
く、弁体９を係止してその位置決めすることがで
きるばかりでなく、小径部で支持することによ
り、弁体９の曲げ強度をあげることも可能であ
る。 The burnt gas discharged from the exhaust port 8a passes through the partition wall 15.
The partition wall 15 is connected to the upper and lower sides of the exhaust passage 8, and the heat is radiated to the cylinder 2, so the partition wall 1
5. Cools well and does not overheat even when formed into a thin wall.
Therefore, there is no obstruction to the outflow of burnt gas.
Further, since the outer circumferential portion of the valve body 9 is in sliding contact with the partition wall 15, it not only obstructs heat radiation to the cylinder 2, but also allows the valve body 9 to be locked and positioned. It is also possible to increase the bending strength of the valve body 9 by supporting it.

この発明は以上のように、シリンダの排気口に
近接した排気通路上面に略鼓形に形成された弁体
収容凹所を設け、そこに略鼓形の弁体を回動自在
に設け、その一部を切り欠いて排気通路とすると
共に、その切り欠かれた縁部を弁体の回動に伴つ
て排気通路内へ進出或いは退去する排気口の上縁
となし、エンジンの運転中にその上縁を上下させ
て、排気口の開口時期を調節出来るようにした二
行程エンジンにおいて、前記排気口から前記弁体
の下流側に至る排気通路を隔壁によつて左右に二
分したから、排気口の幅を大きく設定してもピス
トン４が昇降する際、ピストンリングが拡大され
た排気口に引つ掛かつて損傷するような不具合を
生じることがない。また、前記隔壁には弁体の挿
通孔を設け、隔壁と弁体の外周部とを摺接させた
ので、隔壁の上部が弁体によつて冷却され、局部
的に過熱部を生じることがない等の効果がある。 As described above, the present invention provides a valve body housing recess formed in a substantially hourglass shape on the upper surface of the exhaust passage close to the exhaust port of the cylinder, and a substantially hourglass-shaped valve body is rotatably provided therein. A portion is cut out to form an exhaust passage, and the cut edge is used as the upper edge of the exhaust port that advances or retreats into the exhaust passage as the valve body rotates. In a two-stroke engine in which the opening timing of the exhaust port can be adjusted by raising and lowering the upper edge, the exhaust passage from the exhaust port to the downstream side of the valve body is divided into left and right by a partition wall, so that the exhaust port Even if the width is set large, when the piston 4 moves up and down, the piston ring will not get caught in the enlarged exhaust port and be damaged. Furthermore, since the partition wall is provided with an insertion hole for the valve body, and the partition wall and the outer periphery of the valve body are brought into sliding contact, the upper part of the partition wall is cooled by the valve body, thereby preventing local overheating from occurring. There are effects such as no.

また、実施例のように、隔壁と弁体外周に設け
た溝とを係合させれば、弁体の軸方向の移動を阻
止することが出来、ストツパを兼用することも出
来る。 Further, as in the embodiment, by engaging the partition wall with the groove provided on the outer periphery of the valve body, movement of the valve body in the axial direction can be prevented, and the groove can also be used as a stopper.

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

図面はこの発明の一実施例を示すものであり、
第１図はエンジンの要部を示す断面図、第２図は
その−断面図である。 ８……排気通路、８ａ……排気口、９……弁
体、９ａ……縁部、１５……隔壁。 The drawings show one embodiment of the invention,
FIG. 1 is a cross-sectional view showing the main parts of the engine, and FIG. 2 is a cross-sectional view thereof. 8... Exhaust passage, 8a... Exhaust port, 9... Valve body, 9a... Edge, 15... Partition wall.

Claims (1)

【特許請求の範囲】 １ シリンダの排気口に近接した排気通路の上面
に、略鼓形に形成された弁体収容凹所を設け、そ
こに略鼓形の弁体を回動自在に設け、その一部を
切り欠いて排気通路とすると共に、残部の縁部を
弁体の回動に伴つて排気通路内へ進出あるいは退
去する排気口の上縁となし、エンジンの運転中に
その上縁を上下させて、排気口の開口時期を調節
できるようにした二行程エンジンにおいて、前記
排気口から前記弁体の下流側に至る排気通路を隔
壁によつて左右に二分し、前記隔壁に弁体の挿通
孔を設け、隔壁と弁体の外周部とを摺接させてな
る二行程エンジンの排気装置。 ２ 弁体外周の中央小径部に外周溝を設け、その
外周溝の側壁と隔壁とを摺接させ、弁体の軸方向
の移動を阻止するよう構成された特許請求の範囲
第１項記載の二行程エンジンの排気装置。[Scope of Claims] 1. A substantially hourglass-shaped valve body housing recess is provided on the upper surface of the exhaust passage close to the exhaust port of the cylinder, and a substantially hourglass-shaped valve body is rotatably provided therein, A part of it is cut out to form an exhaust passage, and the remaining edge is used as the upper edge of the exhaust port that advances or retreats into the exhaust passage as the valve body rotates. In a two-stroke engine in which the opening timing of the exhaust port can be adjusted by raising and lowering the exhaust port, the exhaust passage from the exhaust port to the downstream side of the valve body is divided into left and right by a partition wall, and the valve body is attached to the partition wall. An exhaust system for a two-stroke engine, which has an insertion hole and has a partition wall and the outer periphery of a valve body in sliding contact. 2. The valve body according to claim 1, wherein an outer circumferential groove is provided in the central small diameter portion of the outer periphery of the valve body, and the side wall of the outer circumferential groove and the partition wall are brought into sliding contact to prevent the valve body from moving in the axial direction. Exhaust system for two-stroke engines.
JP57214993A 1982-12-08 1982-12-08 Exhaust device of two-cycle engine Granted JPS59105928A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57214993A JPS59105928A (en) 1982-12-08 1982-12-08 Exhaust device of two-cycle engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57214993A JPS59105928A (en) 1982-12-08 1982-12-08 Exhaust device of two-cycle engine

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP31966489A Division JPH02191811A (en) 1989-12-08 1989-12-08 Exhaust device for two-cycle engine

Publications (2)

Publication Number Publication Date
JPS59105928A JPS59105928A (en) 1984-06-19
JPH0514089B2 true JPH0514089B2 (en) 1993-02-24

Family

ID=16664919

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57214993A Granted JPS59105928A (en) 1982-12-08 1982-12-08 Exhaust device of two-cycle engine

Country Status (1)

Country Link
JP (1) JPS59105928A (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0210829B1 (en) * 1985-07-22 1989-11-02 Honda Giken Kogyo Kabushiki Kaisha Exhaust timing control apparatus
EP0212857B1 (en) * 1985-07-22 1990-01-17 Honda Giken Kogyo Kabushiki Kaisha Exhaust timing control apparatus
JPH0635832B2 (en) * 1985-09-11 1994-05-11 本田技研工業株式会社 Exhaust timing control device for 2-cycle engine
JPS62174514A (en) * 1986-01-29 1987-07-31 Honda Motor Co Ltd Exhaust timing control device for two-cycle engine
JPS62267515A (en) * 1986-05-14 1987-11-20 Honda Motor Co Ltd Exhaust timing control device for two-cycle engine
US4776305A (en) * 1986-05-20 1988-10-11 Honda Giken Kogyo Kabushiki Kaisha Exhaust timing control device for two-cycle engines

Also Published As

Publication number Publication date
JPS59105928A (en) 1984-06-19

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