JPH0584817B2 - - Google Patents
Info
- Publication number
- JPH0584817B2 JPH0584817B2 JP16147785A JP16147785A JPH0584817B2 JP H0584817 B2 JPH0584817 B2 JP H0584817B2 JP 16147785 A JP16147785 A JP 16147785A JP 16147785 A JP16147785 A JP 16147785A JP H0584817 B2 JPH0584817 B2 JP H0584817B2
- Authority
- JP
- Japan
- Prior art keywords
- valve body
- cylinder
- exhaust
- recess
- 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 - 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
- Output Control And Ontrol Of Special Type Engine (AREA)
- Characterised By The Charging Evacuation (AREA)
Description
【発明の詳細な説明】
「産業上の利用分野」
本発明は、排気時期制御装置を備えた２サイク
ルエンジンに係わり、詳しくは、排気通路の上部
に弁体を設け、この弁体をエンジンの回転速度に
応じて揺動操作することによりシリンダ内部と排
気通路との連通時期を変化させるようにした２サ
イクルエンジンに関するものである。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a two-stroke engine equipped with an exhaust timing control device. This invention relates to a two-stroke engine in which the timing of communication between the inside of the cylinder and the exhaust passage is changed by performing a rocking operation according to the rotational speed.
「従来の技術」
第１図は本発明者等が先に実願昭60−97274号
として出願した２サイクルエンジンの一部を示す
ものである。``Prior Art'' FIG. 1 shows a part of a two-stroke engine that the present inventors previously filed as Utility Model Application No. 1983-97274.
このエンジンにおいては、排気通路１の上部で
あつてシリンダ内面への開口（排気ポート）１ａ
近傍に、シリンダ軸線に直交するように軸２を設
け、この軸２に弁体３を一体的に取り付け、か
つ、弁体３に相対する排気通路１の上面に弁体３
を収納するための凹所４を設けている。 In this engine, there is an opening (exhaust port) 1a at the upper part of the exhaust passage 1 toward the inner surface of the cylinder.
A shaft 2 is provided nearby so as to be orthogonal to the cylinder axis, a valve body 3 is integrally attached to this shaft 2, and the valve body 3 is attached to the upper surface of the exhaust passage 1 facing the valve body 3.
A recess 4 is provided for storing the.
また、排気ポート１ａの上縁には、弁体３が凹
所４内に収納された際、同弁体３の揺動先端とシ
リンダ内との間にデツドスペースを形成させない
よう、排気通路１の上面から垂れ下がるエツジ部
５を設けている。このエツジ部５の角度は、弁体
３の先端上縁の揺動軌跡の弁体３が弁体収納凹所
４内に収納されたときの接線とシリンダ内面との
成す角度とぼほ同じになるように設定している。 Further, the upper edge of the exhaust port 1a is provided with an exhaust passage 1 so as to prevent a dead space from being formed between the swinging tip of the valve body 3 and the inside of the cylinder when the valve body 3 is housed in the recess 4. An edge portion 5 hanging down from the top surface is provided. The angle of this edge portion 5 is approximately the same as the angle formed by the tangent line of the swing locus of the upper edge of the valve body 3 when the valve body 3 is housed in the valve body storage recess 4 and the inner surface of the cylinder. It is set so that
このエンジンによれば、エンジンの回転速度に
応じて駆動機構により弁体３を揺動操作し、例え
ば、エンジンが低速で回転する場合には、弁体３
を図中実線で示すようにその先端が排気ポート１
ａの上縁から下方へ突出する箇所に位置させ、他
方、エンジンが高速で回転する場合には、図中２
点鎖線で示すように弁体３を排気通路の上部に設
けた凹所４内に収納するよう操作する。このよう
にエンジンの回転速度に応じて排気ポート１ａの
上縁位置を実質的に上下動させ、これにより、エ
ンジンが低速あるいは高速いずれで回転する場合
でも、掃気ポートが閉じた後であつて排気ポート
１ａが閉じる寸前に排気反射波が排気ポート１ａ
に戻るように排気時期の制御を行い、排気通路１
に吹き抜けたガスをシリンダ内に押し戻してガス
充填効率の向上を図り、もつて、全回転域におけ
る出力の向上を図つている。 According to this engine, the drive mechanism swings the valve body 3 according to the rotational speed of the engine. For example, when the engine rotates at a low speed, the valve body 3
As shown by the solid line in the figure, its tip is the exhaust port 1.
2 in the figure when the engine rotates at high speed.
The valve body 3 is operated so as to be accommodated in the recess 4 provided in the upper part of the exhaust passage as shown by the dashed line. In this way, the position of the upper edge of the exhaust port 1a is substantially moved up and down according to the rotational speed of the engine, so that even when the engine rotates at low or high speed, the exhaust port 1a can be closed even after the scavenging port is closed. Just before port 1a closes, the exhaust reflected wave returns to exhaust port 1a.
The exhaust timing is controlled so that the exhaust passage 1 returns to
The gas that has blown through is pushed back into the cylinder to improve gas filling efficiency, thereby increasing output over the entire rotation range.
「発明が解決しようとする問題点」
前述した２サイクルエンジンにあつは、弁体収
納凹所とシリンダ内面との間に形成されるエツジ
部５が鋭く尖つた形状となつており、この部分は
熱容量が極めて小さいこと、また、高温状態の排
気ガスが最初に流れ込む箇所であることから、シ
リンダブロツク等を冷却水で強制的に冷却する場
合でも、同エツジ部５が異常に昇温するという不
具合があることがわかつた。"Problems to be Solved by the Invention" In the above-mentioned two-stroke engine, the edge portion 5 formed between the valve body housing recess and the inner surface of the cylinder has a sharply pointed shape. Since the heat capacity is extremely small and this is the point where high-temperature exhaust gas first flows, there is a problem in which the temperature of the edge portion 5 rises abnormally even when the cylinder block, etc. is forcibly cooled with cooling water. It turns out that there is.
上記不具合を解決するための一手段として、弁
体３を薄くしエツジ部５の突出量を小さくするこ
とも考えられるが、この場合、弁体５が薄く成り
すぎることから、本来の機能である排気時期制御
が行えなくなるという問題が生じる。 One way to solve the above problem is to make the valve body 3 thinner and reduce the amount of protrusion of the edge portion 5, but in this case, the valve body 5 would become too thin, so it would not work as intended. A problem arises in that exhaust timing control cannot be performed.
「発明の目的」
本発明は上記事情に鑑みてなされてもので、所
望する排気時期制御が行え、かつ、弁体収納凹所
とシリンダ内面との間に形成されるエツジ部が異
常に昇温するのを防止することができる２サイク
ルエンジンを提供することを目的とする。``Object of the Invention'' The present invention has been made in view of the above circumstances, and it is possible to perform desired exhaust timing control and prevent the edge portion formed between the valve body housing recess and the inner surface of the cylinder from becoming abnormally heated. The purpose of the present invention is to provide a two-stroke engine that can prevent
「問題点を解決するための手段」
本発明では前述した目的を達成するため、弁体
の揺動先端にシリンダの内面と略同一曲率に成さ
れて同シリンダ内面と整合する制御面が設けら
れ、かつ、制御面の上部には制御面の上縁に連続
しかつ同制御面上縁の揺動軌跡よりも揺動中心側
へ傾斜する傾斜部を有する凸部が設けられ、排気
通路の上部には閉弁時において弁体を収納する凹
所が設けられ、該凹所とシリンダ内周との間に形
成されるエツジ部の角度は、弁体の制御面上縁の
揺動軌跡の、弁体が弁体収納凹所内に収納された
ときの接線とシリンダ内面との成す角度よりも大
きく設定された構成としている。"Means for Solving the Problems" In order to achieve the above-mentioned object, the present invention provides a control surface at the swinging tip of the valve body that has approximately the same curvature as the inner surface of the cylinder and is aligned with the inner surface of the cylinder. , and the upper part of the control surface is provided with a convex part that is continuous with the upper edge of the control surface and has an inclined part that is inclined toward the center of rocking than the rocking locus of the upper edge of the control surface, and the convex part is provided at the upper part of the exhaust passage. is provided with a recess that accommodates the valve element when the valve is closed, and the angle of the edge formed between the recess and the inner circumference of the cylinder is determined by the swing locus of the upper edge of the control surface of the valve element. The angle is set to be larger than the angle formed between the tangent and the inner surface of the cylinder when the valve body is housed in the valve body housing recess.
「実施例」
以下、本発明の一実施例について第２図〜第４
図を参照して説明する。"Example" Hereinafter, an example of the present invention will be described in Figures 2 to 4.
This will be explained with reference to the figures.
第２図は本発明に係わる排気時期制御装置を備
えた２サイクルエンジンの縦断面図、第３図は第
２図の−線に沿う断面図である。 FIG. 2 is a longitudinal sectional view of a two-stroke engine equipped with an exhaust timing control device according to the present invention, and FIG. 3 is a sectional view taken along the line - in FIG.
図において符号１１はシリンダブロツク、１２
はシリンダヘツド、１３はシリンダ内に摺動自在
に嵌挿されたピストン、１４は掃気通路、１５は
排気通路である。排気通路１５の左右方向中央に
は補強用リブ１６が、シリンダ内面への開口（排
気ポート）１５ａから排気通路１５の下流側へ所
定箇所まで延びて設けられている。このリプ１６
は排気通路１５のシリンダ内面への開口近傍を補
強するとともに、ピストンリングがそれ自体の弾
性により径方向外方へ広がつて排気ポート１５ａ
の上縁や下縁に突き当たるのを防止する機能を果
たす。 In the figure, numeral 11 is a cylinder block, 12
13 is a cylinder head, 13 is a piston slidably inserted into the cylinder, 14 is a scavenging passage, and 15 is an exhaust passage. A reinforcing rib 16 is provided at the center of the exhaust passage 15 in the left-right direction, extending from an opening (exhaust port) 15a to the inner surface of the cylinder to a predetermined location on the downstream side of the exhaust passage 15. This reply 16
reinforces the vicinity of the opening of the exhaust passage 15 to the inner surface of the cylinder, and the piston ring expands radially outward due to its own elasticity to open the exhaust port 15a.
It functions to prevent the material from hitting the upper or lower edge of the material.
排気通路１５の上部であつて排気ポート１５ａ
の若干下流側には、後述する弁体を収納するため
の凹所１７が形成されている。凹所１７には軸１
８がシリンダの中心線と直交する方向に延在する
ように回転自在に設けられている。軸１８の中央
部分は断面方形状とされ、そこには排気時期制御
用の弁体１９，１９が間にリプ１６を挟むよう
に、リプ１６の両側に位置して設けられている。
また、軸１８の弁体１９を支持する部分の外側に
はリング溝１８ａが形成されている（第３図参
照）。 At the upper part of the exhaust passage 15, the exhaust port 15a
A recess 17 is formed slightly downstream of the recess 17 for accommodating a valve body to be described later. Shaft 1 is placed in recess 17.
8 is rotatably provided so as to extend in a direction perpendicular to the center line of the cylinder. The central portion of the shaft 18 has a rectangular cross section, and valve bodies 19, 19 for exhaust timing control are provided on both sides of the lip 16 so as to sandwich the lip 16 between them.
Further, a ring groove 18a is formed on the outside of the portion of the shaft 18 that supports the valve body 19 (see FIG. 3).
前記両弁体１９，１９は互いに左右対称となつ
ている。弁体１９は、第４図に示すように軸１８
が挿通される軸挿通部２０と、軸挿通部２０から
一側に延びる平板部２１と、平板部２１の先端
（揺動端）に設けられかつシリンダの内面とほぼ
同一曲率とされてシリンダ内面と整合する制御面
２２と、制御面２２の上部に設けられ、制御面２
２の上縁に連続するとともに制御面２２の上縁の
揺動軌跡よりも揺動中心側へ傾斜する傾斜部２３
ａを有する凸部２３とを備えている。また、弁体
１９の平板部２１には、前記弁収納凹所１７に相
対する上面から排気通路の内周面となる下面に達
する貫通孔２４が、凸部２３側に位置して複数設
けられている。貫通孔２４の上部は径が孔２４の
直径の２倍程度となるよう面取り処理が施されて
いる。上述のように構成された弁体１９はシリン
ダブロツク１１に組み付けれる際、シリンダ内面
と制御面２２との間に若干の〓間ｘを形成するよ
うに組み付けられる。 Both the valve bodies 19, 19 are symmetrical with respect to each other. The valve body 19 is connected to the shaft 18 as shown in FIG.
a shaft insertion portion 20 through which the shaft insertion portion 20 is inserted; a flat plate portion 21 extending from the shaft insertion portion 20 to one side; a control surface 22 aligned with the control surface 22;
An inclined portion 23 that is continuous with the upper edge of the control surface 22 and is inclined toward the center of swing from the swing locus of the upper edge of the control surface 22.
It is provided with a convex portion 23 having a shape. Further, the flat plate portion 21 of the valve body 19 is provided with a plurality of through holes 24 located on the convex portion 23 side and reaching from the upper surface facing the valve storage recess 17 to the lower surface which becomes the inner circumferential surface of the exhaust passage. ing. The upper part of the through hole 24 is chamfered so that the diameter thereof is approximately twice the diameter of the hole 24. When the valve body 19 constructed as described above is assembled into the cylinder block 11, it is assembled so as to form a slight distance x between the inner surface of the cylinder and the control surface 22.
前記凹所１７の下面は弁体１９の上面に対応し
た形状、すなわち、開口側から奥方に向かつて断
面略３角形状の凹部、平坦部、断面円弧状の凹部
が順に設けられた形状と成つている。凹所１７と
シリンダ内面との間にはエツジ部２５が形成さ
れ、該エツジ部２５の角度θ1は、弁体１９の制御
面２２上縁の揺動軌跡の、弁体１９が弁体収納凹
所１７内に収納されたときの接線とシリンダ内面
との成す角度θ2よりも大きく設定されている。 The lower surface of the recess 17 has a shape corresponding to the upper surface of the valve body 19, that is, a recess with a substantially triangular cross section, a flat portion, and a recess with an arcuate cross section are provided in this order from the opening side toward the back. It's on. An edge portion 25 is formed between the recess 17 and the inner surface of the cylinder, and the angle θ 1 of the edge portion 25 is determined by the swing locus of the upper edge of the control surface 22 of the valve body 19 when the valve body 19 is housed in the valve body. The angle θ 2 formed between the tangent and the inner surface of the cylinder when the cylinder is housed in the recess 17 is set to be larger than the angle θ 2 .
弁体１９，１９はエンジンの回転速度に応じ軸
１８を介して駆動機構３０により揺動操作される
ようになつている。すなわち、弁体１９、軸１
８、駆動機構３０によつて、排気通路１５の上部
を開放あるいは閉塞操作する排気時期制御装置が
構成されている。駆動機構３０は第３図に示すよ
うに、軸１８の一端であつてシリンダブロツク１
１の外部に突出する部分に取り付けられたワイヤ
ーガイド３１と、該ワイヤーガイド３１にワイヤ
ー３２を介して接続されたモータ（図示せず）
と、該モータをエンジンの回転速度に応じて正・
逆回転操作する制御器（図示せず）とから成つて
いる。 The valve bodies 19, 19 are oscillated by a drive mechanism 30 via a shaft 18 in accordance with the rotational speed of the engine. That is, the valve body 19, the shaft 1
8. The drive mechanism 30 constitutes an exhaust timing control device that opens or closes the upper part of the exhaust passage 15. As shown in FIG.
a wire guide 31 attached to an externally protruding portion of 1; and a motor (not shown) connected to the wire guide 31 via a wire 32.
, the motor is rotated in the normal direction according to the engine rotation speed.
It consists of a controller (not shown) that operates the rotation in reverse.
また、前記軸１８のシリンダブロツク１１から
突出する部分およびワイヤーガイド３１は、シリ
ンダブロツク１１に取り付けられたワイヤーケー
ス３３およびワイヤーケース３３にねじ止めされ
るケースカバー３４によつて覆われている。な
お、軸１８の一端側には中央部から端部に向かつ
てブツシユ３５、位置決め用コツター３６、シー
ル部材３７が順に配設されている。また、第２図
および第３図中Ｒは冷却水を通すための通路を示
す。 Further, the portion of the shaft 18 protruding from the cylinder block 11 and the wire guide 31 are covered by a wire case 33 attached to the cylinder block 11 and a case cover 34 screwed to the wire case 33. A bush 35, a positioning knob 36, and a seal member 37 are disposed in this order from the center to the end at one end of the shaft 18. Further, R in FIGS. 2 and 3 indicates a passage for passing cooling water.
しかして、このように構成された２サイクルエ
ンジンによれば、弁体１９がエンジンの運転状態
に基づいて操作されることにより、エンジンの出
力特性を全回転域において高めることができる。 According to the two-stroke engine configured in this manner, the output characteristics of the engine can be increased over the entire rotation range by operating the valve body 19 based on the operating state of the engine.
すなわち、エンジンが低回転で運転されている
場合には、軸１８を所定方向へ回転させて弁体１
９，１９を揺動させ、同弁体１９，１９を排気通
路１５内に突出させる。このような弁体１９，１
９の移動により、その制御面２２を排気ポート１
５ａの上部途中に位置させ、これによつて、第１
図中実線で示すように排気ポート１５ａの上部を
閉塞し、同排気ポート１５ａの上縁を見掛け上弁
体１９，１９の制御面２２の下端縁までの距離ｌ
分下げる。したがつて、制御面２２を距離ｌ下げ
た分、ピストン１３の移動により開閉される排気
ポート１５ａは、遅く開かれかつ早く閉じられ
る。 That is, when the engine is operated at low rotation speed, the valve body 1 is rotated by rotating the shaft 18 in a predetermined direction.
9 and 19 to make the valve bodies 19 and 19 protrude into the exhaust passage 15. Such a valve body 19,1
9, the control surface 22 is moved to the exhaust port 1.
5a, and thereby the first
As shown by the solid line in the figure, the upper part of the exhaust port 15a is closed, and the upper edge of the exhaust port 15a is apparently the distance l from the lower edge of the control surface 22 of the valve body 19, 19.
Lower it by a minute. Therefore, the exhaust port 15a, which is opened and closed by the movement of the piston 13, opens later and closes earlier as the control surface 22 is lowered by a distance l.
このように、エンジンが低回転のときには、ピ
ストン１３の上下動周期が長いのに対応させて排
気ポート１５ａを遅く開かせかつ遅く閉じせ、こ
れにより、排気ポート１５ａが閉じられる寸前に
排気反射波を排気ポート１５ａに戻し、燃焼ガス
充填効率を高めている。 In this way, when the engine is running at low speed, the exhaust port 15a is opened late and closed late in response to the long vertical movement period of the piston 13, and as a result, the exhaust reflected wave is generated just before the exhaust port 15a is closed. is returned to the exhaust port 15a to improve combustion gas filling efficiency.
一方、エンジンが高回転域に至つた場合には、
弁体１９，１９を前述とは逆向きに移動させて第
２図中２点鎖線で示すように凹所１７内に収納す
る。すなわちこの場合にあつては、ピストン１３
の上下動周期が短くなるのに対応して、排気ポー
ト１５ａを前述した場合に比べて早く開かせかつ
遅く閉じらせる。したがつて、この場合において
も、排気ポート１５ａが閉じられる寸前に排気反
射波を排気ポート１５ａに戻し、前述と同様、反
射波の有効利用によつて燃焼ガスの充填効率を高
めている。 On the other hand, when the engine reaches a high rotation range,
The valve bodies 19, 19 are moved in the opposite direction to that described above and housed in the recess 17 as shown by the two-dot chain line in FIG. That is, in this case, the piston 13
In response to the shorter vertical movement period of the exhaust port 15a, the exhaust port 15a is opened earlier and closed later than in the case described above. Therefore, in this case as well, the exhaust reflected waves are returned to the exhaust port 15a just before the exhaust port 15a is closed, and as in the case described above, the combustion gas filling efficiency is improved by effectively utilizing the reflected waves.
このように、エンジンの排気時期を弁体１９の
制御面２２によつて制御し、全回転域における出
力特性の向上を図つている。 In this way, the exhaust timing of the engine is controlled by the control surface 22 of the valve body 19, thereby improving the output characteristics over the entire rotation range.
なお、上記弁体１９の制御方法は、２位置制御
等のステツプ式制御、あるいは連続する比例制御
のいずれであつてもよい。 The method of controlling the valve body 19 may be either step control such as two-position control or continuous proportional control.
また、上記２サイクルエンジンにおいて、凹所
１７とシリンダ内面との間に形成されるエツジ部
２５の角度θ1は、弁体１９の制御面２２上縁の揺
動軌跡の、弁体１９が凹所１７内に収納されたと
きの接線とシリンダ内面との成す角度θ2よりも大
きく設定されており、したがつて、その分エツジ
部２５は強度的に強く、かつ熱容量が大きく成つ
ている。この結果、エツジ部２５は第１図に示す
従来のものに比べて変形し難く、かつ、異常に昇
温することもない。 In the above two-stroke engine, the angle θ 1 of the edge portion 25 formed between the recess 17 and the inner surface of the cylinder is determined by the angle θ 1 of the edge portion 25 formed between the recess 17 and the inner surface of the cylinder when the valve body 19 is recessed in the swing locus of the upper edge of the control surface 22 of the valve body 19. The edge portion 25 is set to be larger than the angle θ 2 formed between the tangent line and the inner surface of the cylinder when the cylinder is housed in the housing 17, and accordingly, the edge portion 25 is stronger in strength and has a larger heat capacity. As a result, the edge portion 25 is less likely to deform than the conventional one shown in FIG. 1, and does not become abnormally heated.
また、この２サイクルエンジンでは、弁体１９
が閉じた際に、排気ガスが制御面２２の上側空間
を通つて弁体１９と凹所１７との間の〓間に至
り、そこからさらに、弁体１９の貫通孔２４を通
つて排気通路１５へ抜ける現象が生じ、これがた
めに、排気時期制御が行えなくなるおそれがあ
る。ところが、実験の結果、上記２サイクルエン
ジンでは所望通り排気時期制御が行えることが分
かつた。 In addition, in this two-stroke engine, the valve body 19
When closed, the exhaust gas passes through the space above the control surface 22 and reaches the space between the valve body 19 and the recess 17, and from there, it passes through the through hole 24 of the valve body 19 and enters the exhaust passage. 15, which may make exhaust timing control impossible. However, as a result of experiments, it was found that the exhaust timing can be controlled as desired in the two-stroke engine.
また、上述のように弁体１９の上側をガスが通
る場合であると、同ガスの流れにより、弁体１９
や弁体収納凹所１７を掃除することができ、それ
らにカーボンが付着するのを防止し得るという利
点が得られる。 In addition, when gas passes above the valve body 19 as described above, the flow of the gas causes the valve body 19 to
This has the advantage that the valve body housing recess 17 can be cleaned and carbon can be prevented from adhering thereto.
なお、弁体１９としては、上記実施例のものに
限られることなく、例えば第５図に示すように、
長軸が弁体の長さ方向に延びる長方形状の貫通孔
を並列に並べたもりであつてもよい。このような
弁体１９によれば、貫通孔２４の上縁部に形成さ
れるエツジ部２４ｂを長くとることができ、仮に
凹所１７上面にカーボンが付着し固化した場合で
あつても、同カーボンを前記エツジ部２４ｂでた
たき落とし、孔２４を介して排気通路１５へ排出
することができるといつた利点が得られる。 Note that the valve body 19 is not limited to that of the above embodiment, and for example, as shown in FIG.
It may be a mortar in which rectangular through holes whose long axes extend in the length direction of the valve body are arranged in parallel. According to such a valve body 19, the edge portion 24b formed at the upper edge of the through hole 24 can be made long, and even if carbon adheres to the upper surface of the recess 17 and solidifies, the same The advantage is that carbon can be knocked off by the edge portion 24b and discharged into the exhaust passage 15 through the hole 24.
「発明の効果」
以上説明したように本発明にかかる排気時期弁
体装置によれば、弁体の揺動先端にシリンダの内
面と略同一曲率に成されて同シリンダ内面と整合
する制御面が設けられ、かつ、制御面の上部には
制御面の上縁に連続しかつ同制御面上縁の揺動軌
跡よりも揺動中心側へ傾斜する傾斜部を有する凸
部が設けられ、排気通路の上部には閉弁時におい
て弁体を収納する凹所が設けられ、該凹所とシリ
ンダ内周との間に形成されるエツジ部の角度は、
弁体の制御面上縁の揺動軌跡の、弁体が弁体収納
凹所内に収納されたときの接線とシリンダ内面と
の成す角度よりも大きく設定された構成であるか
ら、所望する排気時期制御が行えるのは勿論、そ
れに加えて、弁体収納凹所とシリンダ内面との間
に形成されるエツジ部が異常に昇温するのを防止
することができる等の効果が得られる。"Effects of the Invention" As explained above, according to the exhaust timing valve body device according to the present invention, the swinging tip of the valve body has a control surface that has approximately the same curvature as the inner surface of the cylinder and is aligned with the inner surface of the cylinder. A convex part is provided on the upper part of the control surface and has an inclined part that is continuous with the upper edge of the control surface and is inclined toward the center of rocking than the rocking trajectory of the upper edge of the control surface, and is connected to the exhaust passage. A recess is provided in the upper part of the valve to accommodate the valve body when the valve is closed, and the angle of the edge formed between the recess and the inner circumference of the cylinder is as follows:
Since the structure is set to be larger than the angle formed by the tangent of the swing locus of the upper edge of the control surface of the valve body when the valve body is stored in the valve body storage recess and the inner surface of the cylinder, the desired exhaust timing can be achieved. In addition to the control, it is also possible to prevent the edge portion formed between the valve body housing recess and the inner surface of the cylinder from becoming abnormally heated.
第１図は排気時期制御装置を備えた従来の２サ
イクルエンジンを示す一部の縦断面図、第２図は
本発明にかかる２サイクルエンジンの縦断面図、
第３図は第２図の−線に沿う断面図、第４図
は弁体の斜視図、第５図は弁体の変形例を示す斜
視図である。
１１……シリンダブロツク、１２……シリンダ
ヘツド、１４……掃気通路、１５……排気通路、
１５ａ……開口（排気ポート）、１７……弁体収
納凹所、１８……軸、１９……弁体、２２……制
御面、２３……凸部、２３ａ……傾斜部、２５…
…エツジ部。
FIG. 1 is a longitudinal sectional view of a part of a conventional two-stroke engine equipped with an exhaust timing control device, FIG. 2 is a longitudinal sectional view of a two-stroke engine according to the present invention,
3 is a sectional view taken along the line - in FIG. 2, FIG. 4 is a perspective view of the valve body, and FIG. 5 is a perspective view showing a modification of the valve body. 11...Cylinder block, 12...Cylinder head, 14...Scavenging passage, 15...Exhaust passage,
15a... Opening (exhaust port), 17... Valve body storage recess, 18... Shaft, 19... Valve body, 22... Control surface, 23... Convex portion, 23a... Inclined portion, 25...
...Etsuji Department.
Claims (1)
へ延びる排気通路の上部を、シリンダ軸線に直交
して配設された軸、該軸によつて支持された弁
体、および前記弁体を揺動操作する弁体駆動機構
とからなる排気時期制御装置により開放あるいは
閉塞して、シリンダ内部と排気通路との連通時期
を変化させるようにした２サイクルエンジンであ
つて、前記弁体の揺動先端にはシリンダの内面と
略同一曲率に成されて同シリンダ内面と整合する
制御面が設けられ、かつ、制御面の上部には制御
面の上縁に連続しかつ同制御面上縁の揺動軌跡よ
りも揺動中心側へ傾斜する傾斜部を有する凸部が
設けられ、前記排気通路の上部には閉弁時におい
て弁体を収納する凹所が設けられ、該凹所とシリ
ンダ内面との間に形成されるエツジ部の角度は、
弁体の制御面上縁の揺動軌跡の、弁体が弁体収納
凹所内に収納されたときの接線とシリンダ内面と
の成す角度よりも大きく設定されていることを特
徴とする排気時期制御装置を備えた２サイクルエ
ンジン。1. A shaft disposed orthogonally to the cylinder axis, a valve body supported by the shaft, and a swinging operation of the valve body are performed on the upper part of the exhaust passage extending outward from the exhaust port opening on the inner surface of the cylinder. The two-stroke engine is configured to open or close an exhaust timing control device consisting of a valve body drive mechanism to change the communication timing between the inside of the cylinder and the exhaust passage, and the swinging tip of the valve body is A control surface is provided that has approximately the same curvature as the inner surface of the cylinder and is aligned with the inner surface of the cylinder, and the upper part of the control surface is continuous with the upper edge of the control surface and is closer to the swing locus of the upper edge of the control surface. A convex portion having an inclined portion inclined toward the center of swing is provided in the exhaust passage, and a recess is provided in the upper part of the exhaust passage to accommodate the valve body when the valve is closed, and a convex portion is provided between the recess and the inner surface of the cylinder. The angle of the edge formed is
Exhaust timing control characterized in that the swing locus of the upper edge of the control surface of the valve body is set to be larger than the angle formed by the tangent to the inner surface of the cylinder when the valve body is stored in the valve body housing recess. Two-stroke engine with equipment.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16147785A JPS6223523A (en) | 1985-07-22 | 1985-07-22 | Two cycle engine provided with exhaust timing controller |
| DE8686305639T DE3668348D1 (en) | 1985-07-22 | 1986-07-22 | DEVICE FOR CONTROLLING THE EXHAUST TIME OF AN INTERNAL COMBUSTION ENGINE. |
| EP86305639A EP0212857B1 (en) | 1985-07-22 | 1986-07-22 | Exhaust timing control apparatus |
| US07/052,131 US4768473A (en) | 1985-07-22 | 1987-05-18 | Exhaust timing control apparatus |
| US07/085,672 US4903647A (en) | 1985-07-22 | 1987-08-13 | Exhaust timing control apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16147785A JPS6223523A (en) | 1985-07-22 | 1985-07-22 | Two cycle engine provided with exhaust timing controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6223523A JPS6223523A (en) | 1987-01-31 |
| JPH0584817B2 true JPH0584817B2 (en) | 1993-12-03 |
Family
ID=15735833
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16147785A Granted JPS6223523A (en) | 1985-07-22 | 1985-07-22 | Two cycle engine provided with exhaust timing controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6223523A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3195147B2 (en) * | 1993-11-27 | 2001-08-06 | 本田技研工業株式会社 | Throttle valve controller for spark-ignition two-stroke engine |
| JP3069228B2 (en) * | 1993-11-27 | 2000-07-24 | 本田技研工業株式会社 | Deceleration control device for spark ignition type two-cycle engine for vehicle |
| JPH07150937A (en) * | 1993-11-27 | 1995-06-13 | Honda Motor Co Ltd | Spark ignition type two-cycle engine cooling system |
-
1985
- 1985-07-22 JP JP16147785A patent/JPS6223523A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6223523A (en) | 1987-01-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |