JPS6054500B2 - Variable stage vaporizer - Google Patents
Variable stage vaporizerInfo
- Publication number
- JPS6054500B2 JPS6054500B2 JP9509477A JP9509477A JPS6054500B2 JP S6054500 B2 JPS6054500 B2 JP S6054500B2 JP 9509477 A JP9509477 A JP 9509477A JP 9509477 A JP9509477 A JP 9509477A JP S6054500 B2 JPS6054500 B2 JP S6054500B2
- Authority
- JP
- Japan
- Prior art keywords
- passage
- fuel
- metering jet
- intake
- vane
- 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
Links
Landscapes
- Control Of The Air-Fuel Ratio Of Carburetors (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
Description
【発明の詳細な説明】
本発明は内燃機関用可変ステージ式気化器に係り、特
に気化器の燃料通路内に滞留する気泡を速かに処理する
ための装置を具備した可変ステージ式気化器に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable stage carburetor for an internal combustion engine, and more particularly to a variable stage carburetor equipped with a device for quickly disposing of air bubbles remaining in the fuel passage of the carburetor. .
最近、気化器の小型化や低背型の要求を満すため、気
化器のフロート室から燃料ノズルに至る燃料通路は複雑
な形状となり、通路内に発生した気泡が滞留しやすくな
つている。 燃料通路に気泡が滞留すると、気泡が成長
し、大きな気泡が燃料計量ジェットを通過する際、一時
的に燃料流を遮断するので、機関が不整運転となつたり
、失火を起すなどの問題があつた。Recently, in order to meet the demand for smaller and lower profile carburetors, the fuel passage from the float chamber of the carburetor to the fuel nozzle has become complex in shape, making it easier for bubbles generated within the passage to remain. If bubbles remain in the fuel passage, they will grow and temporarily block the fuel flow when large bubbles pass through the fuel metering jet, causing problems such as irregular engine operation and misfires. Ta.
特に特開昭５０−５３７３３号公報にあるような、ダ
ウンドラフトタイプの可変ステージ式気化器ではベーン
の先端に設けたニードルが斜上向きに配置されるため、
必然的に下向きの燃料通路が形成される。燃料通路が下
向きに傾斜している場合、発生した気泡が燃料と共に流
れないため気泡の滞留による気泡の成長が著しく前述の
不都合が起りやすかつた。 本発明の目的は、下向き燃
料通路に発生した気泡が成長する前にすみやかに燃料計
量ジェットの下流へ流出させ、気泡が計量ジェットを一
時的に塞ぐことを防止することにある。In particular, in a downdraft type variable stage carburetor as disclosed in Japanese Patent Application Laid-Open No. 50-53733, the needle provided at the tip of the vane is arranged diagonally upward.
A downward fuel passage is inevitably formed. When the fuel passage is inclined downward, the generated air bubbles do not flow together with the fuel, so that the bubbles grow significantly due to the accumulation of air bubbles, and the above-mentioned problems are likely to occur. An object of the present invention is to quickly cause bubbles generated in the downward fuel passage to flow downstream of the fuel metering jet before they grow, thereby preventing the bubbles from temporarily blocking the metering jet.
本発明の特徴は、下向きの燃料通路の最上部と燃料計量
ジェットの上流側にジェットに近接して設けた絞り部と
を連通する気泡抜き通路を燃料通路に並列に設けたこと
にある。A feature of the present invention is that a bubble removal passage is provided in parallel with the fuel passage, which communicates the top of the downward fuel passage with a constriction portion provided upstream of the fuel metering jet and close to the jet.
以下図面に示す実施例について説明する。The embodiments shown in the drawings will be described below.
可変ステージ式気化器は吸気筒１内に取り付けたベーン
２と絞り弁３とをリンク４で連動させ、ベーン３により
ベンチユリ断面積を変化させて常に適当なベンチユリ負
圧を発生させ、ベーン２に連動するジェットニードル５
と固定オリフィス６で構成された燃料計量ジェット７に
より燃料を計量して、前記ベンチユリ負圧によりベンチ
ユリ部に噴出させて適正な混合気を機関に供給するもの
である。The variable stage carburetor has a vane 2 installed in the intake cylinder 1 and a throttle valve 3 linked together by a link 4, and the vane 3 changes the cross-sectional area of the vent lily to always generate an appropriate negative pressure in the vent lily. Interlocking jet needle 5
The fuel is metered by a fuel metering jet 7 composed of a fixed orifice 6, and is injected into the bench lily section by the negative pressure of the bench lily, thereby supplying an appropriate air-fuel mixture to the engine.
従つて可変ステージ式気化器では、ベーン軸９を絞り弁
軸１０とはできるだけ離して設置する方が絞り弁３とベ
ーン２の連動精度上有利であり、かつ、ジェットニード
ル５はベーン先端に取りつけるのがやはり燃料計量精度
およびスペース上有利となるので、この気化器を下向き
通風型として使用する場合は、図面に示すような構成が
有利となり、ジェットニードル５の先端が上向きとなる
ので、燃料計量ジェット７、上流部の燃料通路１１が下
向きになる。したがつてこの下向き燃料通路１１の上端
１５に気泡が滞留し、成長して燃料計量ジェット７の近
くに達し、燃料流量を不規則に変動させる欠点があつた
。そこで、燃量計量ジェット７の上流側にジェット７に
近接してジェット７よりも若干大径でかつ燃料通路１１
の径よりも小さい絞り部１２を形成し、この絞り部１２
と燃料通路１１の上端１５とを連通する気泡抜き通路１
３を設ける。通路１３は、土端１５にたまつた微小な気
泡がこの通路１３を通過する際大きく成長することがな
いような配慮が必要である。Therefore, in the variable stage type carburetor, it is advantageous to install the vane shaft 9 as far away from the throttle valve shaft 10 as possible in terms of the accuracy of the interlocking between the throttle valve 3 and the vane 2, and the jet needle 5 is attached to the tip of the vane. This is advantageous in terms of fuel metering accuracy and space, so when this carburetor is used as a downward ventilation type, the configuration shown in the drawing is advantageous, and the tip of the jet needle 5 faces upward, making it easier to measure fuel. The jet 7 and the upstream fuel passage 11 face downward. Therefore, there is a drawback that air bubbles accumulate at the upper end 15 of the downward fuel passage 11, grow, and reach the vicinity of the fuel metering jet 7, causing irregular fluctuations in the fuel flow rate. Therefore, on the upstream side of the fuel metering jet 7, there is a fuel passage 11 located close to the jet 7 and having a slightly larger diameter than the jet 7.
A constricted portion 12 smaller than the diameter of the constricted portion 12 is formed.
and the upper end 15 of the fuel passage 11.
3 will be provided. The passage 13 requires consideration so that minute air bubbles accumulated on the soil edge 15 do not grow large when passing through the passage 13.
本発明者等の試験結果によれば通路１３の断面積が大き
くなると、この通路の流速が低下し、気泡の移動が良好
に行われないことが判明した。したがつて通路１３の断
面積は通路１１の断面積の半分以下、好ましくは１Ｂ程
度すれば良好な結果が得られた。気泡抜き通路１３は、
下向きの燃料通路１１に並列にしかも通路１１の上側に
設けることが好ましい。According to the test results conducted by the present inventors, it has been found that when the cross-sectional area of the passage 13 becomes large, the flow velocity in this passage decreases, and the movement of bubbles is not performed satisfactorily. Therefore, good results were obtained when the cross-sectional area of the passage 13 was less than half the cross-sectional area of the passage 11, preferably about 1 B. The bubble removal passage 13 is
It is preferable to provide it parallel to the downward fuel passage 11 and above the passage 11.
このような構成の気化器において、機関運転中機関から
の熱などにより燃料中に微小な気泡が発生し、下向き燃
料通路１１の上端１５にたまる。In a carburetor having such a configuration, minute bubbles are generated in the fuel due to heat from the engine during engine operation, and accumulate at the upper end 15 of the downward fuel passage 11.
上端１５と絞り部１２とは気泡抜き通路１３で連通され
ているため、通路１３には機関の運転中上端１５より絞
り部へ向う燃料流が生じている。この燃料流は絞り部１
２を設けたことにより、この部分の燃料流速の増大によ
る圧力低下が、絞り部１２と上端１５間の水頭差を上回
つているために生じるものである。したがつて、微小な
気泡は通路１３を流れる燃料と共に、絞り部１２に至り
、この部分では燃料流速が速いため通路１１内を上昇す
ることなく、計量ジェット７を通つて吸気筒内１に吸引
される。Since the upper end 15 and the throttle part 12 are communicated with each other through the air bubble removal passage 13, a fuel flow is generated in the passage 13 from the upper end 15 toward the throttle part during operation of the engine. This fuel flow is
2, this occurs because the pressure drop due to the increase in fuel flow rate in this portion exceeds the water head difference between the constricted portion 12 and the upper end 15. Therefore, the minute bubbles reach the constriction part 12 together with the fuel flowing through the passage 13, and because the fuel flow rate is high in this part, they do not rise in the passage 11 but are sucked into the intake cylinder 1 through the metering jet 7. be done.
燃料通路１１内に発生した気泡は、上端１５に至ると速
かに通路１３へ流入するため、気泡の成長がなく、微小
なままの状態で計量ジェット７を通過するので、燃料を
一時的にとだえさすことなく、しかも燃料流量の変動も
小さくなる。The bubbles generated in the fuel passage 11 quickly flow into the passage 13 when they reach the upper end 15, so the bubbles do not grow and pass through the metering jet 7 in a minute state, so that the fuel is temporarily absorbed. There is no stagnation, and fluctuations in fuel flow rate are also reduced.
絞り部１２の内径は、これを小さく設定する程通路１３
を流れる燃料流量は増大するが、絞り部１２を小さくす
ると、高速運転時に燃料の抵抗が大きくなる恐れがある
。The smaller the inner diameter of the throttle part 12 is set, the narrower the passage 13 becomes.
However, if the throttle portion 12 is made smaller, there is a risk that the resistance of the fuel will increase during high-speed operation.
それ故、絞り部１２と上端１５の水頭差、発生する気泡
の量などを考慮して絞り部１２の径を決定する。Therefore, the diameter of the constricted part 12 is determined by taking into account the water head difference between the constricted part 12 and the upper end 15, the amount of bubbles generated, and the like.
機関の通常運転状態ては、通路１３を通る燃料も計量ジ
ェット７で計量されるために、気泡抜き通路を設けたこ
とによつて、燃料の計量制度が低″下することはない。Under normal operating conditions of the engine, the fuel passing through the passage 13 is also metered by the metering jet 7, so the provision of the bubble removal passage does not reduce the accuracy of fuel metering.
以上説明したように、本発明によれば、成長した気泡が
計量ジェットを通過することにより発生する燃料流量の
不規則な変動を軽減することができる。As described above, according to the present invention, it is possible to reduce irregular fluctuations in fuel flow rate caused by grown bubbles passing through a metering jet.
図は本発明を実施した可変ステージ式気化器の断面図で
ある。
１・・・・・・吸気筒、２・・・・・・ベーン、３・・
・・・・絞り弁、５・・・・・ニードル、７・・・・・
・燃料計量ジェット、８・・・・・・ベンチユリ部、１
１・・・・・・下向き燃料通路、１２・・・・絞り部、
１３・・・・・気泡抜き通路、１５・・・・・・上端。The figure is a sectional view of a variable stage carburetor embodying the present invention. 1... Intake cylinder, 2... Vane, 3...
... Throttle valve, 5 ... Needle, 7 ...
・Fuel metering jet, 8... Bench lily part, 1
1... Downward fuel passage, 12... Throttle part,
13...Bubble removal passage, 15...Top end.
Claims (1)
気通路を流れる吸気量を制御する絞り弁と、前記絞り弁
の上流で前記吸気通路壁面との間に可変ベンチユリを形
成するベーンと、前記ベーンと前記絞り弁を連通するリ
ンク機構と、前記可変ベンチユリに開口した燃料ノズル
と、前記燃料ノズルから延びその一部に前記吸気通路を
流れる吸気流に向つて斜下向きに燃料が流れる斜下向き
通路部を形成してフロート室に至る燃料通路と、前記斜
下向き通路部に設けた計量ジェットと、前記計量ジェッ
トと協働して燃料を計量するため前記ベーンに取り付け
られたニードルとを備えた可変ステージ式気化器におい
て、前記計量ジェットの上流側に前記計量ジェットに近
接して前記計量ジェットよりも大径でかつ前記斜下向き
通路部よりも小径の絞り部を形成し、前記斜下向き通路
部に並列に前記絞り部と前記計量ジェットの上流側の前
記斜下向き通路部の最高点近傍を連通する気泡抜き通路
を設けた事を特徴とする可変ステージ式気化器。1. An intake passage that allows intake air to flow in a substantially vertical direction, a throttle valve that controls the amount of intake air flowing through the intake passage, and a vane that forms a variable bench lily between the intake passage wall and the intake passage upstream of the throttle valve. a link mechanism that communicates the vane and the throttle valve; a fuel nozzle that opens in the variable bench lily; and a fuel nozzle that extends from the fuel nozzle and partially allows fuel to flow obliquely downward toward the intake flow that flows through the intake passage. A fuel passage forming a passage portion and leading to a float chamber, a metering jet provided in the obliquely downward passage portion, and a needle attached to the vane for cooperating with the metering jet to meter the fuel. In the variable stage carburetor, a constriction part is formed upstream of the metering jet and close to the metering jet and has a larger diameter than the metering jet and a smaller diameter than the diagonally downward passage section, and the slanted downward passage section A variable stage type vaporizer, characterized in that a bubble removal passage is provided in parallel with the throttle part and the vicinity of the highest point of the obliquely downward passage part on the upstream side of the metering jet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9509477A JPS6054500B2 (en) | 1977-08-10 | 1977-08-10 | Variable stage vaporizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9509477A JPS6054500B2 (en) | 1977-08-10 | 1977-08-10 | Variable stage vaporizer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5430321A JPS5430321A (en) | 1979-03-06 |
| JPS6054500B2 true JPS6054500B2 (en) | 1985-11-30 |
Family
ID=14128305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9509477A Expired JPS6054500B2 (en) | 1977-08-10 | 1977-08-10 | Variable stage vaporizer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6054500B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57203849A (en) * | 1981-06-10 | 1982-12-14 | Aisan Ind Co Ltd | Variable venturi carburettor |
| JPS58110843A (en) * | 1981-12-24 | 1983-07-01 | Toyota Motor Corp | Variable venturi type carburetor |
-
1977
- 1977-08-10 JP JP9509477A patent/JPS6054500B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5430321A (en) | 1979-03-06 |
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