JP2002180905A - Carburetor for two-stroke internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carburetor for a two-stroke internal combustion engine so as to introduce fine fuel from a fuel passage to an intake passage of the carburetor. SOLUTION: An intake port 25b and an air inlet 24 vertically arranged to open to a crank chamber 13a and an injection port 22 opened to a combustion chamber 4 are provided in a cylinder 3 of an engine, and an injection pipe 23 connecting the air inlet 24 and the injection port 22 is provided. A throttle valve 39 having reducing holes 36, 40 is turnably and liflably fitted to a valve chest 35 crossing with an intake passage 25 and a fuel passage 21 of a carburetor main unit 34, the intake passage 25 is connected to the intake port 25b, and the fuel passage 21 is connected to the halfway of the injection pipe 23. A needle 37 extended downward from the throttle valve 39 moreover to adjust an opening of a fuel nozzle 38 is inserted to a fuel supply pipe 20 extended to the reducing hole 40 from a fixed pressure fuel chamber 47 of the carburetor main unit 34. A passage hole 62 connecting the reducing hole 40 and 36 is provided in the throttle valve 39.

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】本発明は気化器の吸気通路か
ら空気だけを機関のクランク室へ送り、気化器の燃料通
路から燃料を機関のクランク室と燃焼室とを連通する噴
射管（インジエクシヨンホース）の噴射口に隣接する部
分へ送るようにした２行程内燃機関のための気化器に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection pipe (injection pipe) for sending only air from an intake passage of a carburetor to a crankcase of an engine and for supplying fuel from a fuel passage of the carburetor to a communication between the crankcase and the combustion chamber of the engine. The present invention relates to a carburetor for a two-stroke internal combustion engine which is directed to a portion adjacent to an injection port of a young hose.

【０００２】[0002]

【従来の技術】上述の２行程内燃機関では、気化器の吸
気通路から空気だけをクランク室へ供給する一方、燃料
通路から燃料をクランク室と燃焼室とを結ぶ噴射管の途
中へ供給するものであるので、クランク室には燃料に含
まれる潤滑油が供給されない。このため、クランク軸の
軸受、ピストンと連接棒を連結するピン、連接棒とクラ
ンク腕とを連結する軸部などの潤滑が不十分になり、焼
付きを起す恐れがある。そこで、気化器の燃料通路をク
ランク室へ延長して燃料に含まれる潤滑油を供給するこ
とが考えられるが、クランク室へ供給すべき潤滑油の量
は極く少量であり、油量の調整ないし設定が難しい。2. Description of the Related Art In the above-described two-stroke internal combustion engine, only air is supplied from an intake passage of a carburetor to a crank chamber, while fuel is supplied from a fuel passage to an injection pipe connecting the crank chamber and the combustion chamber. Therefore, the lubricating oil contained in the fuel is not supplied to the crank chamber. Therefore, lubrication of the bearing of the crankshaft, the pin connecting the piston and the connecting rod, and the shaft connecting the connecting rod and the crank arm becomes insufficient, and there is a possibility that seizure may occur. Therefore, it is conceivable to extend the fuel passage of the carburetor to the crankcase and supply the lubricating oil contained in the fuel.However, the amount of the lubricating oil to be supplied to the crankcase is extremely small, and the oil amount is adjusted. Or difficult to set.

【０００３】[0003]

【発明が解決しようとする課題】本発明の課題は上述の
問題に鑑み、気化器の燃料通路から微少燃料を吸気通路
へ導入するようにした２行程内燃機関のための気化器を
提供することにある。SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a carburetor for a two-stroke internal combustion engine in which minute fuel is introduced from a fuel passage of a carburetor into an intake passage. It is in.

【０００４】[0004]

【課題を解決するための手段】上記課題を解決するため
に、本発明の構成は機関のシリンダ壁にクランク室へ上
下に並んで開口する吸気口と空気入口と燃焼室へ開口す
る噴射口とを設け、前記空気入口と前記噴射口とを結ぶ
噴射管を備え、気化器本体に設けた吸気通路と燃料通路
に交差する上下方向の円筒状の弁室に、前記吸気通路と
前記燃料通路に連通する第１，第２の絞り孔をそれぞれ
有する絞り弁を回動可能かつ昇降可能に嵌挿し、前記吸
気通路を前記吸気口に、前記燃料通路を前記噴射管の途
中にそれぞれ接続した２行程内燃機関のための気化器に
おいて、気化器本体の下部に設けた燃料室から前記絞り
弁の軸心に沿つて第２の絞り孔へ延びる燃料供給管に、
前記絞り弁から下方へ延びかつ前記燃料供給管の燃料噴
孔の開度を加減するニードルを嵌挿し、前記絞り弁に第
２の絞り孔と第１の絞り孔を結ぶ通路孔を設けたことを
特徴とする。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an arrangement of the present invention comprises an air inlet, an air inlet, and an air inlet opening to a combustion chamber, which are vertically opened to a crank chamber on a cylinder wall of an engine. Is provided with an injection pipe connecting the air inlet and the injection port, and in a vertical cylindrical valve chamber intersecting an intake passage and a fuel passage provided in a carburetor body, the intake passage and the fuel passage are provided. Two strokes in which throttle valves each having first and second throttle holes communicating therewith are rotatably and vertically liftably fitted, and the intake passage is connected to the intake port, and the fuel passage is connected in the middle of the injection pipe. In a carburetor for an internal combustion engine, a fuel supply pipe extending from a fuel chamber provided in a lower portion of the carburetor body to a second throttle hole along the axis of the throttle valve,
A needle that extends downward from the throttle valve and adjusts the degree of opening of the fuel injection hole of the fuel supply pipe is inserted, and the throttle valve is provided with a passage hole connecting the second throttle hole and the first throttle hole. It is characterized by.

【０００５】また、本発明の構成は機関のシリンダ壁に
クランク室へ上下に並んで開口する吸気口と空気入口と
燃焼室へ開口する噴射口とを設け、前記空気入口と前記
噴射口とを結ぶ噴射管を備え、気化器本体に設けた吸気
通路と燃料通路に交差する上下方向の円筒状の弁室に、
前記吸気通路と前記燃料通路に連通する第１，第２の絞
り孔をそれぞれ有する絞り弁を回動可能かつ昇降可能に
嵌挿し、前記吸気通路を前記吸気口に、前記燃料通路を
前記噴射管の途中にそれぞれ接続した２行程内燃機関の
ための気化器において、気化器本体の下部に設けた燃料
室から前記絞り弁の軸心に沿つて第２の絞り孔へ延びる
燃料供給管に、前記絞り弁から下方へ延びかつ前記燃料
供給管の燃料噴孔の開度を加減するニードルを嵌挿し、
前記吸気通路の入口部に前記吸気通路へ突出する燃料管
を支持し、前記絞り弁に第２の絞り孔から前記燃料管へ
連通する通路孔を設けたことを特徴とする。Further, according to the structure of the present invention, an intake port, an air inlet and an injection port opening to a combustion chamber are provided on a cylinder wall of an engine and arranged vertically in a crank chamber, and the air inlet and the injection port are connected to each other. A vertical valve chamber that crosses the intake passage and the fuel passage provided in the carburetor body,
A throttle valve having first and second throttle holes respectively communicating with the intake passage and the fuel passage is rotatably and vertically movablely fitted therein, and the intake passage is provided at the intake port, and the fuel passage is provided at the injection pipe. A carburetor for a two-stroke internal combustion engine connected to a fuel supply pipe extending from a fuel chamber provided at a lower portion of the carburetor body to a second throttle hole along the axis of the throttle valve. A needle that extends downward from the throttle valve and that adjusts the opening of the fuel injection hole of the fuel supply pipe is inserted,
A fuel pipe projecting into the intake passage is supported at an inlet of the intake passage, and a passage hole communicating with the fuel pipe from a second throttle hole is provided in the throttle valve.

【０００６】[0006]

【発明の実施の形態】本発明では絞り弁の燃料が流れる
絞り孔（第２の絞り孔）と空気が流れる絞り孔（第１の
絞り孔）とを仕切る壁部に両者を結ぶ通路孔を設け、燃
料通路から微少燃料を通路孔を経て吸気通路へ導き、ク
ランク室へ供給する。空気通路の入口へ燃料管を突出
し、絞り弁に燃料が流れる絞り孔（第２の絞り孔）から
前記燃料管へ連通する通路孔を設けてもよい。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a passage hole connecting a throttle valve (a second throttle hole) through which a fuel flows and a throttle hole (a first throttle hole) through which air flows is formed. A small amount of fuel is provided from the fuel passage to the intake passage through the passage hole and supplied to the crank chamber. The fuel pipe may protrude from the inlet of the air passage, and a passage hole communicating with the fuel pipe from a throttle hole (second throttle hole) through which fuel flows through the throttle valve may be provided.

【０００７】[0007]

【実施例】図１に示すように、本発明に係る２行程内燃
機関はシリンダ３にピストン８を嵌装して、ピストン８
の上側に点火栓２により点火される燃料の燃焼室４が区
画される。シリンダ３の下端にはクランクケース１３が
結合され、クランクケース１３に支持したクランク軸１
０と一体の腕１１が連接棒９の下端に軸１２により連結
され、連接棒９の上端はピン７によりピストン８に連結
される。シリンダ３の左壁には吸気通路２５に連なる吸
気口２５ｂが開口され、右壁には排気口６が開口され
る。吸気口２５ｂはピストン８の上昇行程でクランク室
１３ａに連通され、排気口６はピストン８の下死点付近
で燃焼室４に連通される。シリンダ３の前後壁部には、
クランク室１３ａと燃焼室４を連通する上下方向の掃気
通路が設けられ、掃気通路の上端の掃気口５はピストン
８の下死点付近で開くように構成される。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a two-stroke internal combustion engine according to the present invention has a piston
A combustion chamber 4 for fuel ignited by the ignition plug 2 is defined on the upper side. A crankcase 13 is coupled to a lower end of the cylinder 3, and the crankshaft 1 supported by the crankcase 13 is
An arm 11 integrated with the connecting rod 9 is connected to a lower end of the connecting rod 9 by a shaft 12, and an upper end of the connecting rod 9 is connected to the piston 8 by a pin 7. An intake port 25b connected to the intake passage 25 is opened on the left wall of the cylinder 3, and an exhaust port 6 is opened on the right wall. The intake port 25b communicates with the crank chamber 13a during the upward stroke of the piston 8, and the exhaust port 6 communicates with the combustion chamber 4 near the bottom dead center of the piston 8. On the front and rear walls of the cylinder 3,
A vertical scavenging passage communicating between the crank chamber 13a and the combustion chamber 4 is provided, and the scavenging port 5 at the upper end of the scavenging passage is configured to open near the bottom dead center of the piston 8.

【０００８】噴射管２３の下端の空気入口２４は、シリ
ンダ３の左壁の吸気口２５ｂよりも下方の部分でクラン
ク室１３ａに開口されるが、ピストン８の下死点付近で
は空気入口２４は閉じられる。噴射管２３の上端の噴射
口２２はピストン８の下死点付近で燃焼室４に連通する
ように、シリンダ３の左壁に開口される。好ましくは、
噴射管２３の上端の噴射口２２は燃焼室４の上端中心へ
向けて開口される。噴射管２３の噴射口２２に隣接する
部分に、燃料通路２１の出口２１ｂが接続される。The air inlet 24 at the lower end of the injection pipe 23 opens into the crank chamber 13a below the intake port 25b on the left wall of the cylinder 3, but near the bottom dead center of the piston 8, the air inlet 24 is closed. Closed. The injection port 22 at the upper end of the injection pipe 23 is opened in the left wall of the cylinder 3 so as to communicate with the combustion chamber 4 near the bottom dead center of the piston 8. Preferably,
The injection port 22 at the upper end of the injection pipe 23 is opened toward the center of the upper end of the combustion chamber 4. An outlet 21b of the fuel passage 21 is connected to a portion of the injection pipe 23 adjacent to the injection port 22.

【０００９】吸気口２５ｂに接続する吸気通路２５と、
噴射管２３に接続する燃料通路２１とを有するロータリ
絞り弁式気化器３１は、図２に示すように構成される。
気化器本体３４には気化器本体３４を横貫する吸気通路
２５と燃料通路２１が上下に配され、これらの通路２
５，２１と交差する円筒状の弁室３５に、円柱状の絞り
弁３９が回動可能かつ昇降可能に嵌装される。弁室３５
の上端は蓋板３２により閉鎖され、絞り弁３９から蓋板
３２を貫通して上方へ突出する弁軸３３には絞り弁レバ
ーが結合され、該絞り弁レバーの下面に形成した円弧状
をなしかつ深さが次第に浅くなるカム溝に、蓋板３２か
ら上方へ突出するフオロアを係合してカム機構が構成さ
れる。弁軸３３に緩く巻き付けた戻しばねの一端が絞り
弁３９に、他端が気化器本体３４にそれぞれ係止され、
この戻しばねにより絞り弁３９はアイドル位置へ回転付
勢されるとともに、絞り弁レバーのカム溝がフオロアへ
付勢係合される。絞り弁３９には絞り孔３６と絞り孔４
０が設けられる。An intake passage 25 connected to the intake port 25b;
The rotary throttle valve carburetor 31 having the fuel passage 21 connected to the injection pipe 23 is configured as shown in FIG.
An intake passage 25 and a fuel passage 21 that pass through the carburetor body 34 are vertically arranged in the carburetor body 34.
A cylindrical throttle valve 39 is fitted in a cylindrical valve chamber 35 that intersects 5 and 21 so that it can rotate and move up and down. Valve chamber 35
The upper end of the throttle valve is closed by a lid plate 32, and a throttle valve lever is connected to a valve shaft 33 which penetrates the lid plate 32 from the throttle valve 39 and protrudes upward, and forms an arc shape formed on the lower surface of the throttle valve lever. A cam mechanism is formed by engaging a follower projecting upward from the lid plate 32 into a cam groove having a gradually decreasing depth. One end of the return spring loosely wound around the valve shaft 33 is locked to the throttle valve 39, and the other end is locked to the carburetor body 34, respectively.
This return spring urges the throttle valve 39 to the idle position, and urges the cam groove of the throttle valve lever to the follower. The throttle valve 39 has the throttle hole 36 and the throttle hole 4.
0 is provided.

【００１０】本発明によれば、気化器３１の燃料通路２
１から微少燃料を吸気通路２５へ導入するために、絞り
弁３９の燃料が流れる絞り孔（第２の絞り孔）４０と空
気が流れる絞り孔（第１の絞り孔）３６とを仕切る壁部
に通路孔６２が設けられる。通路孔６２には燃料量を設
定する絞りが一体的に形成されるが、別個の絞りを通路
孔６２に嵌合してもよい。According to the present invention, the fuel passage 2 of the carburetor 31
In order to introduce the minute fuel from 1 into the intake passage 25, a wall portion that partitions a throttle hole (second throttle hole) 40 of the throttle valve 39 through which fuel flows and a throttle hole (first throttle hole) 36 through which air flows. Is provided with a passage hole 62. A throttle for setting the fuel amount is formed integrally with the passage hole 62, but a separate throttle may be fitted into the passage hole 62.

【００１１】図３に示すように、気化器３１の吸気通路
２５の入口部に設けた通路方向の溝６５に、Ｌ形の燃料
管６４を嵌合支持し、燃料管６４の基端を弁室３５へ開
口し、燃料管６４の先端を吸気通路２５へ突出する。絞
り弁３９に燃料が流れる絞り孔（第２の絞り孔）４０か
ら燃料管６４の基端へ連通する通路孔６３を設けてもよ
い。この実施例では、絞り弁３９の昇降に伴つて通路孔
６３と燃料管６４の基端との連通度が加減される。As shown in FIG. 3, an L-shaped fuel pipe 64 is fitted and supported in a groove 65 in the passage direction provided at the inlet of the intake passage 25 of the carburetor 31, and the base end of the fuel pipe 64 is valved. The fuel pipe 64 opens to the chamber 35 and the tip of the fuel pipe 64 protrudes into the intake passage 25. The throttle valve 39 may be provided with a passage hole 63 communicating from the throttle hole (second throttle hole) 40 through which fuel flows to the base end of the fuel pipe 64. In this embodiment, as the throttle valve 39 moves up and down, the degree of communication between the passage hole 63 and the base end of the fuel pipe 64 is adjusted.

【００１２】気化器本体３４の下端部には膜５８により
区画される定圧燃料室４７が備えられ、定圧燃料室４７
の燃料が逆止弁４９、燃料ジエツト４８、燃料供給管２
０の燃料噴孔３８、絞り孔４０を経て燃料通路２１へ供
給されるようになつている。燃料供給管２０は気化器本
体３４の底部に固定され、絞り弁３９の軸心を貫通して
絞り孔４０へ突出される一方、弁軸３３に支持したニー
ドル３７が燃料供給管２０へ嵌挿され、燃料噴孔３８の
開度が調整される。すなわち、絞り弁レバーによる絞り
弁３９をアイドル位置から全開位置へ回動すると、燃料
通路２１に対する絞り孔４０の開度と、吸気通路２５に
対する絞り孔３６の開度が増加し、同時にニードル３７
がカム機構により引き上げられ、燃料噴孔３８の開度が
増加する。At the lower end of the carburetor body 34, a constant pressure fuel chamber 47 defined by a membrane 58 is provided.
The fuel of check valve 49, fuel jet 48, fuel supply pipe 2
The fuel is supplied to the fuel passage 21 through the zero fuel injection hole 38 and the throttle hole 40. The fuel supply pipe 20 is fixed to the bottom of the carburetor body 34, penetrates through the axial center of the throttle valve 39, and projects into the throttle hole 40, while the needle 37 supported on the valve shaft 33 is inserted into the fuel supply pipe 20. Thus, the opening of the fuel injection hole 38 is adjusted. That is, when the throttle valve 39 is rotated from the idle position to the fully open position by the throttle valve lever, the opening degree of the throttle hole 40 with respect to the fuel passage 21 and the opening degree of the throttle hole 36 with respect to the intake passage 25 increase.
Is raised by the cam mechanism, and the opening of the fuel injection hole 38 increases.

【００１３】気化器本体３４の下面に膜４２ａを挟んで
中間壁体４６が結合され、膜４２ａの上側に脈動圧導入
室４２を、膜４２ａの下側にポンプ室４３をそれぞれ区
画して燃料ポンプ４１が形成される。燃料ポンプ４１の
脈動圧導入室４２には機関のクランク室の脈動圧が導入
され、膜４２ａが上下に振幅すると、図示してない燃料
槽の燃料が管６１、逆止弁５３、通路５２を経てポンプ
室４３へ吸い込まれ、逆止弁４４、通路５１、流入弁５
４を経て定圧燃料室４７へ供給される。An intermediate wall 46 is connected to the lower surface of the vaporizer main body 34 with a membrane 42a interposed therebetween. A pulsation pressure introducing chamber 42 is defined above the membrane 42a, and a pump chamber 43 is defined below the membrane 42a. A pump 41 is formed. When the pulsating pressure of the engine crank chamber is introduced into the pulsating pressure introducing chamber 42 of the fuel pump 41 and the membrane 42a oscillates up and down, the fuel in the fuel tank (not shown) flows through the pipe 61, the check valve 53 and the passage 52. Through the pump chamber 43, the check valve 44, the passage 51, the inflow valve 5
4, the fuel is supplied to the constant-pressure fuel chamber 47.

【００１４】定圧燃料供給機構Ａは中間壁体４６の下面
に膜５８を挟んで底板５５を結合し、膜５８の上側に定
圧燃料室４７を、膜５８の下側に大気孔５７を有する大
気室５６をそれぞれ区画される。定圧燃料室４７の壁部
に支軸６０より支持したレバー５９の左端が、ばね５０
の力により膜５８の中心突起へ付勢係合される一方、レ
バー５９の右端が流入弁５４に係止される。定圧燃料室
４７の燃料が少くなると、膜５８の上側に作用する吸気
負圧と膜５８の下側に作用する大気圧とにより膜５８が
引き上げられ、レバー５９が支軸６０を中心として時計
方向へ回動されて流入弁５４が開き、燃料ポンプ４１か
ら燃料が補給される。定圧燃料室４７に燃料が充満する
と膜５８が押し下げられ、レバー５９がばね５０の力に
より反時計方向へ回動され、流入弁５４が閉じる。The constant-pressure fuel supply mechanism A has a bottom plate 55 connected to the lower surface of the intermediate wall 46 with a film 58 interposed therebetween, and has a constant-pressure fuel chamber 47 above the film 58 and an air hole 57 below the film 58. Each of the chambers 56 is partitioned. The left end of the lever 59 supported by the support shaft 60 on the wall of the constant pressure fuel chamber 47 is a spring 50.
The right end of the lever 59 is locked by the inflow valve 54 while being urged into engagement with the central projection of the membrane 58 by the force of. When the fuel in the constant pressure fuel chamber 47 becomes low, the film 58 is pulled up by the intake negative pressure acting on the upper side of the film 58 and the atmospheric pressure acting on the lower side of the film 58, and the lever 59 is rotated clockwise about the support shaft 60. Then, the inflow valve 54 is opened, and fuel is supplied from the fuel pump 41. When the constant pressure fuel chamber 47 is filled with fuel, the membrane 58 is pushed down, the lever 59 is rotated counterclockwise by the force of the spring 50, and the inflow valve 54 is closed.

【００１５】気化器本体３４の左端壁には図示してない
空気清浄器が接続され、右端壁は図示してない断熱性材
料からなる連結部材を挟んでシリンダ３の壁部に結合さ
れる。連結部材により燃料通路２１が逆止弁（好ましく
はリード弁）を経て噴射管２３の噴射口２２に隣接する
部分へ連通され、吸気通路２５が吸気口２５ｂへ連通さ
れる。An air purifier (not shown) is connected to the left end wall of the vaporizer main body 34, and the right end wall is connected to the wall of the cylinder 3 via a connecting member made of a heat insulating material (not shown). The connecting member connects the fuel passage 21 to a portion of the injection pipe 23 adjacent to the injection port 22 via a check valve (preferably a reed valve), and the intake path 25 communicates to the intake port 25b.

【００１６】次に、本発明による気化器を備えた２行程
内燃機関の作動について説明する。ピストン８がシリン
ダ３の上端部へ近付くと、燃焼室４の混合気が圧縮さ
れ、点火栓２により点火される。点火された混合気の膨
脹はピストン８を押し下げる。この爆発行程で機関が動
力を発生する。爆発行程でピストン８が下降すると、ク
ランク室１３ａの内部の空気が加圧され、空気の一部が
空気入口２４から噴射管２３へ圧送され、噴射管２３の
内部で濃い混合気が生成される。Next, the operation of the two-stroke internal combustion engine provided with the carburetor according to the present invention will be described. When the piston 8 approaches the upper end of the cylinder 3, the air-fuel mixture in the combustion chamber 4 is compressed and ignited by the spark plug 2. Expansion of the ignited mixture pushes down the piston 8. The engine generates power during this explosion stroke. When the piston 8 descends during the explosion stroke, the air inside the crank chamber 13a is pressurized, and a part of the air is pumped from the air inlet 24 to the injection pipe 23, and a rich air-fuel mixture is generated inside the injection pipe 23. .

【００１７】ピストン８が下死点付近に達すると、噴射
管２３の下端の空気入口２４が閉鎖され、排気口６が開
かれ、やや遅れて噴射口２２が開かれる。噴射口２２か
らの燃料の噴射時期は、排気の排出を促す時間だけ遅れ
て開くようになつている。噴射管２３の内部の高圧の混
合気が噴射口２２から燃焼室４の上壁中心へ向けて噴射
される。一方、燃焼（膨脹）ガスないし排気は排気口６
へ排出され、クランク室１３ａの新鮮な空気が掃気口５
を経て燃焼室４へ供給される。掃気口５からの空気の一
部は未燃焼のハイドロカーボンの燃焼を助け、空気の残
部は排気と一緒に排気口６へ流れる。ピストン８が上昇
する時、ピストン８は噴射口２２からの混合気が排気口
６へ逃げないように、混合気を燃焼室４の上部へ送り込
むように働く。When the piston 8 reaches the vicinity of the bottom dead center, the air inlet 24 at the lower end of the injection pipe 23 is closed, the exhaust port 6 is opened, and the injection port 22 is opened slightly later. The injection timing of the fuel from the injection port 22 is configured to be opened with a delay of the time for promoting the exhaustion. A high-pressure mixture inside the injection pipe 23 is injected from the injection port 22 toward the center of the upper wall of the combustion chamber 4. On the other hand, the combustion (expansion) gas or exhaust gas
And the fresh air in the crank chamber 13a is discharged to the scavenging port 5
And supplied to the combustion chamber 4. Part of the air from the scavenging port 5 assists the combustion of unburned hydrocarbons, and the rest of the air flows to the exhaust port 6 together with the exhaust. When the piston 8 rises, the piston 8 works to feed the mixture to the upper part of the combustion chamber 4 so that the mixture from the injection port 22 does not escape to the exhaust port 6.

【００１８】上述のように、本発明によれば、気化器本
体３４の吸気通路２５から吸気口２５ｂを経てクランク
室１３ａへ空気が供給される一方、燃料供給管２０から
の燃料は絞り弁３９の開度に対応して絞られる絞り孔４
０、燃料通路２１を経て濃い混合気として噴射管２３へ
吸い出され、空気入口２４からの空気と混合され、噴射
口２２を経て燃焼室４へ供給される。As described above, according to the present invention, air is supplied from the intake passage 25 of the carburetor body 34 to the crank chamber 13a via the intake port 25b, while fuel from the fuel supply pipe 20 is supplied to the throttle valve 39. Aperture 4 that can be narrowed according to the opening
0, it is sucked into the injection pipe 23 as a rich mixture through the fuel passage 21, mixed with air from the air inlet 24, and supplied to the combustion chamber 4 through the injection port 22.

【００１９】ピストン８が下死点を過ぎると、やがて噴
射口２２、掃気口５、排気口６がほぼ同時に閉じ、続い
て噴射管２３の下端の空気入口２４と吸気口２５ｂが開
く。この時、燃料供給管２０の燃料噴孔３８からの燃料
と絞り孔４０の空気との混合気の一部が、通路孔６２を
経て吸気通路２５へ吸引され、吸気通路２５の空気とと
もに、吸気口２５ｂからクランク室１３ａへ吸入され
る。燃料に含まれる潤滑油がクランク軸１０の軸受、ピ
ストン８と連接棒９を連結するピン７、連接棒９とクラ
ンク腕１１を連結する軸１２の潤滑が達せられる。同時
に、燃料供給管２０からの燃料が濃い混合気として絞り
孔４０、燃料通路２１、逆止弁を経て噴射管２３へ吸い
出される。When the piston 8 passes through the bottom dead center, the injection port 22, the scavenging port 5, and the exhaust port 6 close almost simultaneously, and then the air inlet 24 and the intake port 25b at the lower end of the injection pipe 23 open. At this time, a part of the mixture of the fuel from the fuel injection hole 38 of the fuel supply pipe 20 and the air in the throttle hole 40 is sucked into the intake passage 25 through the passage hole 62, and is taken into the intake passage 25 together with the air in the intake passage 25. It is sucked into the crank chamber 13a from the port 25b. The lubricating oil contained in the fuel achieves lubrication of the bearing of the crankshaft 10, the pin 7 connecting the piston 8 and the connecting rod 9, and the shaft 12 connecting the connecting rod 9 and the crank arm 11. At the same time, the fuel from the fuel supply pipe 20 is drawn into the injection pipe 23 through the throttle hole 40, the fuel passage 21, and the check valve as a rich mixture.

【００２０】図３の実施例でも、図２に実施例と同様
に、クランク室１３ａの潤滑が得られ、特に絞り弁３９
の上昇に伴い、通路孔６３の開度が増加する。In the embodiment shown in FIG. 3, as in the embodiment shown in FIG.
, The opening of the passage hole 63 increases.

【００２１】[0021]

【発明の効果】本発明は上述のように、機関のシリンダ
壁にクランク室へ上下に並んで開口する吸気口と空気入
口と燃焼室へ開口する噴射口とを設け、前記空気入口と
前記噴射口とを結ぶ噴射管を備え、気化器本体に設けた
吸気通路と燃料通路に交差する上下方向の円筒状の弁室
に、前記吸気通路と前記燃料通路に連通する第１，第２
の絞り孔をそれぞれ有する絞り弁を回動可能かつ昇降可
能に嵌挿し、前記吸気通路を前記吸気口に、前記燃料通
路を前記噴射管の途中にそれぞれ接続した２行程内燃機
関のための気化器において、気化器本体の下部に設けた
燃料室から前記絞り弁の軸心に沿つて第２の絞り孔へ延
びる燃料供給管に、前記絞り弁から下方へ延びかつ前記
燃料供給管の燃料噴孔の開度を加減するニードルを嵌挿
し、前記絞り弁に第２の絞り孔と第１の絞り孔を結ぶ通
路孔を設けたものであり、クランク室から空気が掃気口
を経て燃焼室へ送られるので、燃焼室の未燃焼のハイド
ロカーボンの燃焼が促進され、排気が浄化される。As described above, according to the present invention, an intake port, an air inlet, and an injection port, which open to the combustion chamber, are provided on the cylinder wall of the engine so as to be vertically arranged in the crank chamber. A first and a second valve communicating with the intake passage and the fuel passage in a vertical cylindrical valve chamber intersecting the intake passage and the fuel passage provided in the carburetor body;
A carburetor for a two-stroke internal combustion engine, in which throttle valves each having a throttle hole are rotatably and vertically inserted, and the intake passage is connected to the intake port, and the fuel passage is connected in the middle of the injection pipe. , A fuel supply pipe extending from a fuel chamber provided at a lower portion of a carburetor body to a second throttle hole along an axis of the throttle valve, and a fuel injection hole extending downward from the throttle valve and extending through the fuel supply pipe. The throttle valve is provided with a passage hole connecting the second throttle hole and the first throttle hole, and air is sent from the crank chamber to the combustion chamber through the scavenging port. Therefore, the combustion of the unburned hydrocarbon in the combustion chamber is promoted, and the exhaust gas is purified.

【００２２】噴射口からの燃料の噴射時期が排気の排出
を促す時間だけ遅れて開くようになつているので、噴射
口からの燃料が排気と一緒に排気口へ逃げる量が少な
く、燃料が燃焼に有効に使われるので、機関の燃費が向
上され、またエミツシヨンが効果的に減じられる。Since the injection timing of the fuel from the injection port is delayed by the time for promoting the discharge of the exhaust gas, the amount of the fuel from the injection port that escapes to the exhaust port together with the exhaust gas is small. As a result, the fuel efficiency of the engine is improved, and emissions are effectively reduced.

【００２３】気化器の燃料通路から微少燃料を絞り弁の
通路孔を経て吸気通路へ送るようにしたので、微少燃料
がクランク室へ供給され、燃料に含まれる潤滑油により
クランク室の軸受部などが潤滑される。Since the minute fuel is sent from the fuel passage of the carburetor to the intake passage through the passage hole of the throttle valve, the minute fuel is supplied to the crank chamber, and the lubricating oil contained in the fuel causes the bearing portion of the crank chamber and the like. Is lubricated.

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

【図１】本発明に係る２行程内燃機関の正面断面図であ
る。FIG. 1 is a front sectional view of a two-stroke internal combustion engine according to the present invention.

【図２】同２行程内燃機関のためのロータリ絞り弁式気
化器を示す正面断面図である。FIG. 2 is a front sectional view showing a rotary throttle valve carburetor for the two-stroke internal combustion engine.

【図３】同２行程内燃機関のための他のロータリ絞り弁
式気化器を示す正面断面図である。FIG. 3 is a front sectional view showing another rotary throttle valve type carburetor for the two-stroke internal combustion engine.

【符号の説明】[Explanation of symbols]

Ａ：定圧燃料供給機構 ２：点火栓 ３：シリンダ
４：燃焼室 ５：掃気口 ６：排気口 ７：ピン ８：ピストン ９：連接棒 １
０：クランク軸 １１：腕 １２：軸 １３：クランク
ケース １３ａ：クランク室 ２０：燃料供給管 ２１：燃料通路 ２１ｂ：出口 ２２：噴射口 ２３：
噴射管 ２４：空気入口 ２５：吸気通路 ２５ｂ：吸
気口 ３１：気化器 ３２：蓋板 ３３：弁軸 ３４：気化器本体 ３５：弁室 ３６：絞り孔 ３７：
ニードル ３８：燃料噴孔 ３９：絞り弁 ４０：絞り
孔 ４１：燃料ポンプ ４２：脈動圧導入室 ４２ａ：膜 ４３：ポンプ室 ４４：逆止弁 ４６：中
間壁体 ４７：定圧燃料室 ４８：燃料ジエツト ４
９：逆止弁 ５０：ばね ５３：逆止弁 ５４：流入弁
５５：底板 ５６：大気室 ５７：大気孔 ５８：膜
５９：レバー ６０：支軸 ６１：燃料管 ６２：通
路孔 ６３：通路孔A: Constant pressure fuel supply mechanism 2: Spark plug 3: Cylinder
4: Combustion chamber 5: Scavenging port 6: Exhaust port 7: Pin 8: Piston 9: Connecting rod 1
0: crankshaft 11: arm 12: shaft 13: crankcase 13a: crankcase 20: fuel supply pipe 21: fuel passage 21b: outlet 22: injection port 23:
Injection pipe 24: Air inlet 25: Intake passage 25b: Intake port 31: Vaporizer 32: Cover plate 33: Valve shaft 34: Vaporizer main body 35: Valve chamber 36: Restrictor hole 37:
Needle 38: Fuel injection hole 39: Throttle valve 40: Throttle hole 41: Fuel pump 42: Pulsating pressure introduction chamber 42a: Membrane 43: Pump chamber 44: Check valve 46: Intermediate wall 47: Constant pressure fuel chamber 48: Fuel jet 4
9: check valve 50: spring 53: check valve 54: inflow valve 55: bottom plate 56: atmosphere chamber 57: atmosphere hole 58: membrane 59: lever 60: support shaft 61: fuel pipe 62: passage hole 63: passage hole

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】機関のシリンダ壁にクランク室へ上下に並
んで開口する吸気口と空気入口と燃焼室へ開口する噴射
口とを設け、前記空気入口と前記噴射口とを結ぶ噴射管
を備え、気化器本体に設けた吸気通路と燃料通路に交差
する上下方向の円筒状の弁室に、前記吸気通路と前記燃
料通路に連通する第１，第２の絞り孔をそれぞれ有する
絞り弁を回動可能かつ昇降可能に嵌挿し、前記吸気通路
を前記吸気口に、前記燃料通路を前記噴射管の途中にそ
れぞれ接続した２行程内燃機関のための気化器におい
て、気化器本体の下部に設けた燃料室から前記絞り弁の
軸心に沿つて第２の絞り孔へ延びる燃料供給管に、前記
絞り弁から下方へ延びかつ前記燃料供給管の燃料噴孔の
開度を加減するニードルを嵌挿し、前記絞り弁に第２の
絞り孔と第１の絞り孔を結ぶ通路孔を設けたことを特徴
とする２行程内燃機関のための気化器。An injection pipe is provided in a cylinder wall of an engine, the intake pipe being open vertically to a crank chamber, an air inlet, and an injection port opening to a combustion chamber, and an injection pipe connecting the air inlet and the injection port. A throttle valve having first and second throttle holes communicating with the intake passage and the fuel passage is provided in a vertical cylindrical valve chamber intersecting the intake passage and the fuel passage provided in the carburetor body. A carburetor for a two-stroke internal combustion engine, which is movably and vertically movable, and has the intake passage connected to the intake port and the fuel passage connected in the middle of the injection pipe. A needle that extends downward from the throttle valve and that adjusts the degree of opening of the fuel injection hole of the fuel supply pipe is inserted into a fuel supply pipe extending from the fuel chamber to a second throttle hole along the axis of the throttle valve. A second throttle hole and a first throttle in the throttle valve. Vaporizer for two-stroke internal combustion engine, characterized in that a passage hole for connecting. 【請求項２】機関のシリンダ壁にクランク室へ上下に並
んで開口する吸気口と空気入口と燃焼室へ開口する噴射
口とを設け、前記空気入口と前記噴射口とを結ぶ噴射管
を備え、気化器本体に設けた吸気通路と燃料通路に交差
する上下方向の円筒状の弁室に、前記吸気通路と前記燃
料通路に連通する第１，第２の絞り孔をそれぞれ有する
絞り弁を回動可能かつ昇降可能に嵌挿し、前記吸気通路
を前記吸気口に、前記燃料通路を前記噴射管の途中にそ
れぞれ接続した２行程内燃機関のための気化器におい
て、気化器本体の下部に設けた燃料室から前記絞り弁の
軸心に沿つて第２の絞り孔へ延びる燃料供給管に、前記
絞り弁から下方へ延びかつ前記燃料供給管の燃料噴孔の
開度を加減するニードルを嵌挿し、前記吸気通路の入口
部に前記吸気通路へ突出する燃料管を支持し、前記絞り
弁に第２の絞り孔から前記燃料管へ連通する通路孔を設
けたことを特徴とする２行程内燃機関のための気化器。2. An engine according to claim 1, further comprising an injection pipe formed in said cylinder wall of said engine, said intake opening being open vertically to said crank chamber, an air inlet and an injection opening opening to said combustion chamber, and connecting said air inlet and said injection port. A throttle valve having first and second throttle holes communicating with the intake passage and the fuel passage is provided in a vertical cylindrical valve chamber intersecting the intake passage and the fuel passage provided in the carburetor body. A carburetor for a two-stroke internal combustion engine, which is movably and vertically movable, and has the intake passage connected to the intake port and the fuel passage connected in the middle of the injection pipe. A needle is inserted into a fuel supply pipe extending from the fuel chamber to a second throttle hole along the axis of the throttle valve, the needle extending downward from the throttle valve and adjusting the degree of opening of the fuel injection hole of the fuel supply pipe. At the inlet of the intake passage to the intake passage Vaporizer for two-stroke internal combustion engine which supports the fuel pipe and out, and wherein the second throttle bore in the throttle valve to the provision of the passage hole communicating to the fuel pipe. 【請求項３】前記通路孔に絞りを設けた、請求項１，２
に記載の２行程内燃機関のための気化器。3. The method according to claim 1, wherein a throttle is provided in said passage hole.
A carburetor for a two-stroke internal combustion engine according to claim 1.