JPS58107845A - Variable venturi carburetor - Google Patents
Variable venturi carburetorInfo
- Publication number
- JPS58107845A JPS58107845A JP20520281A JP20520281A JPS58107845A JP S58107845 A JPS58107845 A JP S58107845A JP 20520281 A JP20520281 A JP 20520281A JP 20520281 A JP20520281 A JP 20520281A JP S58107845 A JPS58107845 A JP S58107845A
- Authority
- JP
- Japan
- Prior art keywords
- negative pressure
- piston
- suction
- venturi
- suction piston
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M7/00—Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
- F02M7/12—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves
- F02M7/14—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle
- F02M7/16—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis
- F02M7/17—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis by a pneumatically adjustable piston-like element, e.g. constant depression carburettors
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of The Air-Fuel Ratio Of Carburetors (AREA)
Abstract
Description
【発明の詳細な説明】 本発明は可変ベンチュリ型気化器に関する。[Detailed description of the invention] The present invention relates to a variable venturi type carburetor.
可変ベンチュリ型気化器はベンチュリ面積を変化させる
サクションピストンと、サクションピストン會摺動可能
に収容するサクションピストンケーシングとを具備し、
サクションピストンケーシングの内部はサクションピス
トンによって負圧室と大気圧室とに分離される。サクシ
ョンピストンの先端面にはサクションピストン負圧室ト
ペンチュリ部とを連通ずるサクション孔が形成され、サ
クションピストンは負圧室と大気圧室との圧力差が一定
となるように、即ちベンチュリ部内の負圧が一定と々る
ように移動する。しかしながらベンチュリ部内の９圧は
必ずしも一様ではなく、サクションピストン先端面の表
面上では他の箇所に比べて負圧が小さいばかりでなく吸
入空気流の乱れが激しいために負圧が一定しない。従っ
て従来のように丈りンヨンピストン先端面にサクション
孔が開口しているとサクション孔に加わる負圧が小さな
ためにサクションピストンの開口面積が十分に大きくな
らず、その結果吸入効率が低下するという問題を生ずる
。更に、サクション孔に加わる負圧が変動するためにサ
クションピストンが不安定となり、それによって供給さ
れる燃料の量が一定しないという問題を生ずる。The variable venturi type carburetor includes a suction piston that changes the venturi area, and a suction piston casing that slidably accommodates the suction piston,
The interior of the suction piston casing is separated into a negative pressure chamber and an atmospheric pressure chamber by the suction piston. A suction hole is formed on the tip surface of the suction piston to communicate with the topenturi section of the suction piston negative pressure chamber, and the suction piston is designed to keep the pressure difference between the negative pressure chamber and the atmospheric pressure chamber constant, that is, the suction hole inside the venturi section. Move so that the pressure remains constant. However, the pressure within the venturi portion is not necessarily uniform, and the negative pressure is not constant on the surface of the tip of the suction piston because it is not only smaller than at other locations, but also because the intake air flow is severely turbulent. Therefore, if the suction hole is opened at the tip of the long piston as in the past, the negative pressure applied to the suction hole is small, so the opening area of the suction piston is not large enough, resulting in a decrease in suction efficiency. This causes a problem. Furthermore, the suction piston becomes unstable due to fluctuations in the negative pressure applied to the suction hole, resulting in a problem that the amount of fuel supplied is not constant.
本発明はサクション孔に加わる負圧をできるだけ大きく
してサクションピストンの開口面積全増大することによ
り吸入効率を高め、更にサクション孔に加われ９圧が変
動しないようにして安定した燃料の供給を確保するよう
にした可変ベンチュリ型気化器を提供することにある。The present invention increases the suction efficiency by increasing the negative pressure applied to the suction hole as much as possible and increasing the total opening area of the suction piston, and also ensures a stable fuel supply by preventing the pressure applied to the suction hole from fluctuating. An object of the present invention is to provide a variable venturi type carburetor.
以下、添附図面を参照して本発明を詳細ＫＨ＜２明する
。Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings.
第１図を参照すると、１は気化器本体、２は垂直方向に
延びる吸気通路、３は吸気通路２内を横方向に移動する
サクションピストン、４はサクションピストン３の先端
面に取付けられたニードル、５はサクションピストン３
の先端面に対向して吸気通路２の内壁面上に固定された
スペーサ、６はサクションピストン３下流の吸気通路２
内に設けられたスロットル弁、７は気化器フロート室を
夫々示し、サクションピストン３の先端面トス４−サ５
の間にはベンチュリ部８が形成される。気化器本体１に
は中空円筒状のケーシング９が固定され、このケーシン
グ９にはケーシング９の内部でケーシング９の軸線方向
に延びる案内スリーブ１０が取付けられる。案内スＩＪ
−７’ＩＯ内には多数の？−ル１１を見えた軸受１２が
挿入され、また案内スリーブ１０の外端部は盲蓋１３に
よって閉鎖される。一方、サクションピストン３には案
内ロッド１４が固定され、この案内ロッド１４は軸受１
２内に案内ロッド１４の軸線方向に移動可能に挿入され
る。このようにサクションピストン３は軸受１２′１に
介してケーシング９によシ支持されるのでサクションピ
ストン３はその軸線力向に滑らかに移動することができ
る。ケーシング９の内部はサクションピストン３によっ
て負圧室１５と大気圧室１６とに分割され、負圧室１５
内にはサクションピストン３を常時ベンチュリ部８に向
けて押圧する圧縮はね１７が挿入される。負圧室１５は
サクションピストン３に形成されたサクション孔１８を
介してベンチュリ部８に連結され、大気圧室１６は気化
器本体１に形成された空気孔１９を介してサクションピ
ストン３上流の吸気通路２内に連結される。Referring to FIG. 1, 1 is a carburetor main body, 2 is an intake passage extending vertically, 3 is a suction piston that moves laterally within the intake passage 2, and 4 is a needle attached to the tip surface of the suction piston 3. , 5 is suction piston 3
A spacer 6 is fixed on the inner wall surface of the intake passage 2 facing the tip surface of the intake passage 2 downstream of the suction piston 3.
Throttle valves 7 are provided within the float chambers of the carburetor, respectively, and the tip surfaces of the suction piston 3 are
A venturi portion 8 is formed between them. A hollow cylindrical casing 9 is fixed to the carburetor body 1, and a guide sleeve 10 extending in the axial direction of the casing 9 inside the casing 9 is attached. Guide IJ
-7' There are many ? - The bearing 12 is inserted through the guide sleeve 11 and the outer end of the guide sleeve 10 is closed by a blind cover 13. On the other hand, a guide rod 14 is fixed to the suction piston 3, and this guide rod 14 is attached to the bearing 1.
2 so as to be movable in the axial direction of the guide rod 14. Since the suction piston 3 is thus supported by the casing 9 via the bearing 12'1, the suction piston 3 can move smoothly in the direction of its axial force. The interior of the casing 9 is divided into a negative pressure chamber 15 and an atmospheric pressure chamber 16 by the suction piston 3.
A compression spring 17 that constantly presses the suction piston 3 toward the venturi portion 8 is inserted therein. The negative pressure chamber 15 is connected to the venturi section 8 through a suction hole 18 formed in the suction piston 3, and the atmospheric pressure chamber 16 is connected to the intake air upstream of the suction piston 3 through an air hole 19 formed in the carburetor body 1. It is connected within the passage 2.
一方、気化器本体１内にはニードル４が侵入可能なよう
にニードル４の軸線方向に延びる燃料通路２０が形成さ
れ、この燃料通路２０内には計量ジェット２１が設けら
れる。計１ジェット２１上流の燃料通路２０は下方に延
びる燃料パイプ２２を介してフロート室７に連結され、
フロート室７内の燃料はこの燃料ノクイゾ２２を介して
燃料通路２０内に送り込まれる。更に、スペーサ５には
燃料通路２０と共軸的に配置された中空円筒状のノズル
２３が固定される。このノズル２３はスペーサ５の内壁
面からベンチュリ部８内に突出し、しかもノズル２３の
先端部の上半分は下半分から更にサクションピストン３
に向けて突出している。On the other hand, a fuel passage 20 extending in the axial direction of the needle 4 is formed in the carburetor body 1 so that the needle 4 can enter therein, and a metering jet 21 is provided within this fuel passage 20. A fuel passage 20 upstream of a total of one jet 21 is connected to the float chamber 7 via a fuel pipe 22 extending downward.
The fuel in the float chamber 7 is sent into the fuel passage 20 via this fuel nozzle 22. Furthermore, a hollow cylindrical nozzle 23 arranged coaxially with the fuel passage 20 is fixed to the spacer 5 . This nozzle 23 protrudes into the venturi portion 8 from the inner wall surface of the spacer 5, and the upper half of the tip of the nozzle 23 is further connected to the suction piston 3 from the lower half.
protruding towards.
ニードル４はノズル２３並びに計量ジェット２１内を貫
通して延び、燃料はニードル４と計量ジェット２１間に
形成される環状間隙により計量された後にノズル２３か
ら吸気通路２内に供給される。The needle 4 extends through the nozzle 23 as well as the metering jet 21 , and the fuel is metered by the annular gap formed between the needle 4 and the metering jet 21 before being fed from the nozzle 23 into the intake passage 2 .
第１図に示すようにスペーサ５の上端部には吸気通路２
内に向けて水平方向に突出する***壁２４が形成され、
この***壁２４とサクションピストン３の先端部間にお
いて流量制御が行なわれる。機関運転が開始されると空
気は吸気通路２内を下方に向けて流れる。このとき空気
流はサクションピストン３と***壁２４間において絞ら
れるためにペンテ−り部８には負圧が発生し、この負圧
がサクシ、ン孔１８を介して自圧室１５内に導ひかれる
。サクションピストン３は負圧室１５と大気圧室１６と
の圧力差が圧縮ばね１７のばね力により定まるほぼ一定
圧となるように、即ちペン九り部８内の負圧がほぼ一定
となるように移動する。As shown in FIG. 1, an intake passage 2 is provided at the upper end of the spacer 5.
A raised wall 24 is formed that projects inward in the horizontal direction,
Flow rate control is performed between this raised wall 24 and the tip of the suction piston 3. When engine operation is started, air flows downward in the intake passage 2. At this time, the airflow is constricted between the suction piston 3 and the raised wall 24, so negative pressure is generated in the pentacle 8, and this negative pressure is introduced into the self-pressure chamber 15 through the suction hole 18. I get run over. The suction piston 3 is arranged so that the pressure difference between the negative pressure chamber 15 and the atmospheric pressure chamber 16 becomes a substantially constant pressure determined by the spring force of the compression spring 17, that is, the negative pressure inside the pen holder 8 becomes substantially constant. Move to.
第１図を参照するとサクション孔１８内にはサクション
ピストン３の先端面２５からベンチュリ部８内に突出す
る負圧導入管２６が嵌着され、との負圧導入管２６の先
端開口２７はベンチュリ部８内に開口する。ベンチュリ
部８内はその中心部において最も流速が速く、サクショ
ンピストン先端面２５並びにスペーサ５の壁面に近づく
に従って流速が遅くなる。従りてベンチュリ部８内の静
圧はその中心部において最も低くなっており、負圧導入
管２６はこの最も負圧の大きな領域に開口しているため
に負圧室１５の負圧は大きくなる。Referring to FIG. 1, a negative pressure introduction pipe 26 protruding from the distal end surface 25 of the suction piston 3 into the venturi portion 8 is fitted into the suction hole 18, and a distal opening 27 of the negative pressure introduction pipe 26 is fitted into the suction hole 18. It opens into the section 8. Inside the venturi portion 8, the flow velocity is highest at its center, and the flow velocity becomes slower as it approaches the suction piston tip surface 25 and the wall surface of the spacer 5. Therefore, the static pressure within the venturi section 8 is lowest at its center, and since the negative pressure introduction pipe 26 opens into this area where the negative pressure is greatest, the negative pressure in the negative pressure chamber 15 is large. Become.
その結果、サクションピストン３のリフト量が大きくな
るために流通開口面積が増大［７、斯くして吸入効率を
向上することができる。一方、ペンチ、９部８の中心部
を流れる吸入空気中に発生する乱れはサタンヨンピスト
ン先端面２５に沿って流れる吸入空気中に発生する乱れ
よりもはるかに弱く、斯くしてベンチュリ部８の中心部
における負圧変動が小さなためにサクションピストン３
のリフトｉｔ吸入空気量に応じた一定量に保持すること
ができる。As a result, the lift amount of the suction piston 3 increases, so the area of the flow opening increases [7, thus the suction efficiency can be improved. On the other hand, the turbulence occurring in the intake air flowing through the center of the pliers 9 part 8 is much weaker than the turbulence occurring in the intake air flowing along the front end surface 25 of the satanyon piston. Suction piston 3 due to small negative pressure fluctuations in the center
The lift can be maintained at a constant amount depending on the amount of intake air.
第２図並びに第３図に夫々別の実施例を示す。Different embodiments are shown in FIG. 2 and FIG. 3, respectively.
第２図に示す実施例では吸入空気中の乱れの影響全受け
ないように負圧導入管２８の先端部が斜めに切断されて
おり、第３図に示す実施例では吸入空気中の乱れを更に
受けないように負圧導入管２９の開口３０が下向きに形
成されている。In the embodiment shown in FIG. 2, the tip of the negative pressure introduction pipe 28 is cut obliquely so as not to be affected by turbulence in the intake air, and in the embodiment shown in FIG. The opening 30 of the negative pressure introduction pipe 29 is formed downward so as not to receive the negative pressure further.
以上述べたように本発明によればサクションピストン負
王室内にベンチュリ部内の最も大きくかつ変動の少ない
負圧を導びくことによってザク４ンピストンのリフトを
増大せしめることができ、かつサクションピストンのり
フトｌ°が同−吸入空気量に対して変化するの全阻止す
ることができる。As described above, according to the present invention, it is possible to increase the lift of the four-wheel piston by guiding the largest negative pressure in the venturi section into the suction piston negative chamber, and the lift of the suction piston can be increased. It is possible to completely prevent the temperature from changing for the same amount of intake air.
その結果、吸入効率を向上できると共に安定した燃料の
供給全確保することができる。As a result, the suction efficiency can be improved and a stable supply of fuel can be ensured.
第１図は本発明による可変ベンチュリ型気化器の側面断
面図、第２図は別の実施例を示すサク各ンピストンの一
部の側面断面図、第３図は更に別の実施例を示すサクシ
ョンピストンの一部の側面断面図である。
１・・・気化器本体、３・・・サクションピストン、４
・・・ニードル、６・・・スロットル弁、１８・・・サ
クション孔、２１・・・計量シュエト、２６，２８．２
９・・・負圧導入管。FIG. 1 is a side sectional view of a variable venturi type carburetor according to the present invention, FIG. 2 is a side sectional view of a part of a suction piston showing another embodiment, and FIG. 3 is a side sectional view of a part of a suction piston showing another embodiment. FIG. 3 is a side cross-sectional view of a portion of the piston. 1... Carburetor body, 3... Suction piston, 4
... Needle, 6... Throttle valve, 18... Suction hole, 21... Measuring shoe, 26, 28.2
9...Negative pressure introduction pipe.
Claims (1)
ションピストンと、該サクションピストンに連結された
ニート°ルと、該ニードルが侵入可能なように該ニード
ルの軸線方向に延びる燃料通路と、該燃料通路内に設け
られて該ニードルと協働する計量ジェットとを具備した
可変ベンチュリ型気化器において、上記ザクジョンピス
トンの負圧室とベンチュリ部を連通せしめるために該サ
クションピストンの先端面に形成したサクション孔にベ
ンチュリ部内に突出する負圧導入管を嵌着した可変ベン
チュリ型気化器。A suction piston that changes a venturi area in response to intake air leaves, a needle connected to the suction piston, a fuel passage extending in the axial direction of the needle so that the needle can enter therein, and the fuel passage. In a variable venturi type carburetor equipped with a metering jet disposed within the suction piston and cooperating with the needle, a suction is formed on the distal end surface of the suction piston to communicate the negative pressure chamber of the suction piston with the venturi portion. A variable venturi type vaporizer in which a negative pressure introduction pipe that protrudes into the venturi part is fitted into the hole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20520281A JPS58107845A (en) | 1981-12-21 | 1981-12-21 | Variable venturi carburetor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20520281A JPS58107845A (en) | 1981-12-21 | 1981-12-21 | Variable venturi carburetor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS58107845A true JPS58107845A (en) | 1983-06-27 |
Family
ID=16503086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20520281A Pending JPS58107845A (en) | 1981-12-21 | 1981-12-21 | Variable venturi carburetor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58107845A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5707560A (en) * | 1996-08-12 | 1998-01-13 | Dynojet Research, Inc. | Constant velocity carburetor with variable venturi slide having bleed holes at an oblique angle and method of operation |
-
1981
- 1981-12-21 JP JP20520281A patent/JPS58107845A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5707560A (en) * | 1996-08-12 | 1998-01-13 | Dynojet Research, Inc. | Constant velocity carburetor with variable venturi slide having bleed holes at an oblique angle and method of operation |
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