JPH01257761A - Mechanism for controlling air-fuel ratio of fuel injection device - Google Patents
Mechanism for controlling air-fuel ratio of fuel injection deviceInfo
- Publication number
- JPH01257761A JPH01257761A JP63084336A JP8433688A JPH01257761A JP H01257761 A JPH01257761 A JP H01257761A JP 63084336 A JP63084336 A JP 63084336A JP 8433688 A JP8433688 A JP 8433688A JP H01257761 A JPH01257761 A JP H01257761A
- Authority
- JP
- Japan
- Prior art keywords
- negative pressure
- fuel
- air
- slow
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 126
- 238000002347 injection Methods 0.000 title claims description 30
- 239000007924 injection Substances 0.000 title claims description 30
- 230000007246 mechanism Effects 0.000 title claims description 8
- 239000000203 mixture Substances 0.000 claims abstract description 14
- 241000234435 Lilium Species 0.000 claims description 4
- 238000006073 displacement reaction Methods 0.000 claims 1
- 238000005192 partition Methods 0.000 claims 1
- 239000002131 composite material Substances 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000004044 response Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 239000011800 void material Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
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
- F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
- F02M69/04—Injectors peculiar thereto
- F02M69/042—Positioning of injectors with respect to engine, e.g. in the air intake conduit
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は空気流量に応じた負圧に基づいて燃料噴射量を
制御する燃料噴射装置における混合気の空燃比制御機構
に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air-fuel ratio control mechanism for an air-fuel mixture in a fuel injection device that controls a fuel injection amount based on a negative pressure depending on an air flow rate.
この種の圧力バランス式燃料噴射装置として例えば本件
出願人が実願昭６３−１２２５４号を以って提案したも
のがあり、この装置の原理を第４圓に基づいて説明する
。吸気通路１のベンチユリ部２に隣接して燃料制御部３
が配設されており、外１向するー・方の内壁に設けられ
た負圧レギュレータ４は開１’ｌ ５ ａによってベン
チユリ部２に連通ずる負圧室５が負圧ダイアフラム６に
よって仕切られており、他方の内壁に設けられた燃圧レ
ギュレータ７は噴射口８ａをもってベンチユリ部２に開
口する燃料噴射室８と燃料ポンプから加圧された燃料が
送り込まれる燃圧室９とが燃料ダイアフラＪ、↓０によ
って画成されており、また３！！！、料噴射室８と燃圧
室９とはメインジェノｔ・ｌ ］を介して連通されてい
る。そして、負圧ダイアフラム６と燃料ダイアフラム】
０とを連結する連結棒１２には噴η・１０３ ａを開閉
して燃料噴射室８内の燃料を吸気ｉＪｌ路１内へ噴射さ
ゼ得るバルブ＋２２が形成されている。An example of this type of pressure-balanced fuel injection device is one proposed by the present applicant in Utility Model Application No. 12254/1983, and the principle of this device will be explained based on the fourth circle. A fuel control section 3 is installed adjacent to the bench lily section 2 of the intake passage 1.
A negative pressure regulator 4 provided on the inner wall facing outward has a negative pressure chamber 5 which communicates with the bench lily part 2 through an opening 1'l5a and is partitioned by a negative pressure diaphragm 6. The fuel pressure regulator 7 provided on the other inner wall has a fuel injection chamber 8 which opens into the bench lily part 2 with an injection port 8a, and a fuel pressure chamber 9 into which pressurized fuel is sent from the fuel pump, and a fuel diaphragm J, ↓ It is defined by 0 and also 3! ! ! , the fuel injection chamber 8 and the fuel pressure chamber 9 are communicated via a main generator t·l. And the negative pressure diaphragm 6 and the fuel diaphragm]
A valve +22 is formed on the connecting rod 12 that connects the fuel injection chamber 8 to the intake air passage 1 by opening and closing the injection η·103a to inject the fuel in the fuel injection chamber 8 into the intake air passage 1.
このような構成のもとてヘンチコ、り部３の空気流量に
応じた負圧が負圧室５内に導入されて匂圧ダイアフラム
６が負圧室５側に変位ゼしめられると、燃料ダイアフう
ム１０も同様に変位せしめられ゛ζバルブ１２ａが噴射
口８ａを開いて燃料が噴射され、燃料噴射室８内の圧力
が低下する。イして、負圧と大気圧の差圧とメインンｓ
−ｙ ｌ□ ｌ ｌの前後の燃圧差による圧力とがバラ
ンスするａ、ｔ゛＋圧ダ圧子イアフラム６料ダイアフラ
ム１０とにかかる圧力がバランスし、この状態で混合気
の空燃比が一定に維持される。With this configuration, when a negative pressure corresponding to the air flow rate in the henchock section 3 is introduced into the negative pressure chamber 5 and the odor pressure diaphragm 6 is displaced toward the negative pressure chamber 5 side, the fuel diaphragm The arm 10 is similarly displaced, the ζ valve 12a opens the injection port 8a, fuel is injected, and the pressure inside the fuel injection chamber 8 is reduced. Then, the differential pressure between negative pressure and atmospheric pressure and the main
-y l□ l The pressure due to the fuel pressure difference before and after l is balanced, and the pressure applied to a, t゛ + pressure indenter iaphragm 6, diaphragm 10 is balanced, and in this state, the air-fuel ratio of the mixture is maintained constant. be done.
第５図は、このような燃￥」制御部３の空気と燃料の流
星制御範囲を異ならゼた、王にメインゾーンを制御する
メイン系燃料制御部１３と主にス冒−ヅーンを制御する
スロー系燃料制御部１４とを設け、広範囲に亘って混合
気の空燃比を制御せＵ７めるようにした燃料噴射装置を
示すものであり、実願昭６３−１２２５４号等を以って
本件出願人により提示されている。Figure 5 shows that the air and fuel control ranges of the fuel control unit 3 are different, with the main system fuel control unit 13 controlling the main zone and the main system fuel control unit 13 mainly controlling the blast zone. This shows a fuel injection device that is equipped with a slow system fuel control section 14 to control the air-fuel ratio of the air-fuel mixture over a wide range. Presented by the applicant.
ところで、第４図においてｒｊ圧室５に設りられていて
負圧ダイアフラム６を大気室側に弾ｆｆするスプリング
］５の荷重Ｗ、を両ダイアフラノ、６及び１０と連結棒
】２を含めたタイアフラムハルブＤＶ全体の重量Ｗ２と
ｓ Ｌ ＜ した場合、始動時もよ空気流量が小さいた
めに第６図（Ａ）に示すように負圧が発生せず、同図（
Ｂ）に示すように空気流量の変化に対して、燃料流量が
所定の一定空燃比を得るための目標値に対して大きさＸ
のズレを生してしまい、結局同図（Ｃ）に示すようにメ
インゾーンにおりるスロットルバルブ開度の増大に対し
て混合気の目標とする空燃比に到達するまで時間がかか
ってしまうという欠点があった。そして、第５図におけ
る燃料噴射装置の場合、スローゾーンからメインゾーン
への移行時に第６図（Ｄ）に示すようにスロー系とメイ
ン系とで空燃比の乱れが生してしまい、スローゾーンと
メインゾーンのつながりがスムーズでなかった。By the way, in Fig. 4, the load W of the spring [5] installed in the RJ pressure chamber 5 and elasticizing the negative pressure diaphragm 6 toward the atmospheric chamber side is calculated by the load W of the spring [5], which is installed in the RJ pressure chamber 5, and which includes both diaphragms, 6 and 10, and the connecting rod [2]. When the weight W2 of the whole tire flamm hull DV and s L <, the air flow rate is small even at the time of starting, so negative pressure is not generated as shown in Figure 6 (A), and the same figure (
As shown in B), with respect to changes in the air flow rate, the fuel flow rate increases with respect to the target value for obtaining a predetermined constant air-fuel ratio.
As a result, as shown in Figure (C), it takes time for the mixture to reach the target air-fuel ratio as the throttle valve opening increases in the main zone. There were drawbacks. In the case of the fuel injection device shown in Fig. 5, when transitioning from the slow zone to the main zone, a disturbance in the air-fuel ratio occurs between the slow system and the main system as shown in Fig. 6 (D). The connection between the main zone and the main zone was not smooth.
そこで、メインゾーンの初期がら空燃比を目標値に一致
させるために第４図に示したスプリング１５の荷重Ｗ１
をダイアフラムバルブＤＶの重量Ｗ２より小ざ（するか
、又は第７図に示すように大気室側に負圧ダイアフラム
６を負圧室５側へ荷重Ｗ、によって弾圧する補正用スプ
リング１６と該スプリング１６の荷重Ｗ３を調整する調
整スクリュ１７とを設けるかして、空気流量に対する負
圧ダイアフラム６の作動を鋭敏にし、これによって空気
流量の変化に対して燃料流量をメインゾーンの初期から
ほぼ目標値に達せしめることを可能にしく第８図（Ａ）
）、？Ｈ合気の空燃比を同様に初期からほぼ目標値に制
御することができる（同図（Ｂ））ようにしたものであ
った。Therefore, in order to make the air-fuel ratio match the target value from the initial stage of the main zone, the load W1 of the spring 15 shown in FIG.
is smaller than the weight W2 of the diaphragm valve DV (or as shown in FIG. By providing an adjustment screw 17 for adjusting the load W3 of 16, the operation of the negative pressure diaphragm 6 in response to the air flow rate is made more sensitive, thereby adjusting the fuel flow rate to almost the target value from the initial stage of the main zone in response to changes in the air flow rate. Figure 8 (A)
),? Similarly, the air-fuel ratio of the H gas mixture can be controlled to approximately the target value from the initial stage ((B) in the same figure).
しかし、このような構成にすると、負圧ダイアフラム６
を負圧室５側へ押圧するノｊが強いため、エンジンの停
止時においても噴射口８ａに対してバルブ１．２ ａが
開弁したままの状態となって燃料漏れが生したり、スロ
ーゾーンの空気流量の小さい段階でもメイン系燃料制御
部から燃料が吐出してオーバーリッチになってしまった
り（第８図（Ｃ））、或いは再始動時にエンジンキーを
ＯＮして燃料ポンプが作動した状態でエンジンが回転し
始める前に燃料が噴射口８ａから吐出してしまう等の不
具合があった。However, with such a configuration, the negative pressure diaphragm 6
Since the pressure of the fuel injection valve toward the negative pressure chamber 5 is strong, the valve 1.2a remains open relative to the injection port 8a even when the engine is stopped, causing fuel leakage and slow Even when the air flow rate in the zone is small, fuel is discharged from the main system fuel control unit and the engine becomes overrich (Figure 8 (C)), or the fuel pump is activated when the engine key is turned on when restarting. In this case, there were problems such as fuel being discharged from the injection port 8a before the engine started rotating.
本発明はこのような課題に鑑み、スローゾーンからの移
行時も含めてメインゾーンの混合気の空燃比を一定に維
持できるようにすると共に、エンジンの停止時や再始動
時における燃料の不必要な吐出を確実に防止できる燃料
噴射装置の空燃比制御機構を提供することを目的とする
。In view of these problems, the present invention makes it possible to maintain a constant air-fuel ratio of the air-fuel mixture in the main zone, including when transitioning from the slow zone, and eliminates the need for fuel when stopping or restarting the engine. An object of the present invention is to provide an air-fuel ratio control mechanism for a fuel injection device that can reliably prevent excessive discharge.
本発明に係る燃料噴射装置の空燃比制御機構は、スロ−
系燃料制御部とメイン系燃料制御部とを備えた燃料噴射
装置において、
ベンチュリ部の負圧をメイン系燃料制御部の負圧室に導
入させるメイン系負圧通路と、エアバルブの下流側の負
圧をスロー系燃料制御部の負圧室に導入さゼるスロー系
負圧通路と、メイン系負圧通路とスロ−系負圧通路を接
続するバイパス通路と、このバイパス通路に設けられて
いてスロー系負圧通路からメイン系負圧通路へ印加され
る負圧の印加量を調整し得る調整手段とを備えていて、
メイン系燃料制御部によってスローゾーンからメインゾ
ーンへの移行時とメインゾーンにおける混合気の空燃比
を一定に制御させるようにしだものである。The air-fuel ratio control mechanism of the fuel injection device according to the present invention has a slow
In a fuel injection device equipped with a system fuel control section and a main system fuel control section, there is a main system negative pressure passage that introduces negative pressure of the venturi section into the negative pressure chamber of the main system fuel control section, and a main system negative pressure passage that introduces negative pressure of the venturi section into the negative pressure chamber of the main system fuel control section, and a main system negative pressure passage that introduces negative pressure of the venturi section into the negative pressure chamber of the main system fuel control section. A slow system negative pressure passage through which pressure is introduced into the negative pressure chamber of the slow system fuel control section, a bypass passage connecting the main system negative pressure passage and the slow system negative pressure passage, and a bypass passage provided in this bypass passage. and adjustment means capable of adjusting the amount of negative pressure applied from the slow system negative pressure passage to the main system negative pressure passage,
The main system fuel control section controls the air-fuel ratio of the air-fuel mixture during transition from the slow zone to the main zone and in the main zone to be constant.
又、スローゾーンにおいてメイン系燃料制御部の負圧室
に導入せしめられる負圧が所定の大きさを越えるまでは
、バルブを閉弁させる圧力が開弁させる圧力より大きい
ように弾性部材が配置されている。Further, the elastic member is arranged so that the pressure for closing the valve is greater than the pressure for opening the valve until the negative pressure introduced into the negative pressure chamber of the main system fuel control section in the slow zone exceeds a predetermined level. ing.
従って、スローゾーンにおいてバイパス通路を介してエ
アバルブ下流側の負圧が所定量だけメイン系負圧通路に
印加され、ベンチュリ部の負圧との合成負圧としてメイ
ン系燃料制御部の負圧室に導入され、この合成負圧が所
定の大きさを越えるとバルブが開弁されて燃料が吐出し
始め、スローゾーンからメインゾーンへの移行時とメイ
ンゾーンにおける混合気の空燃比を一定に維持させるこ
とができる。Therefore, in the slow zone, a predetermined amount of the negative pressure on the downstream side of the air valve is applied to the main system negative pressure passage via the bypass passage, and is applied to the negative pressure chamber of the main system fuel control section as a composite negative pressure with the negative pressure of the venturi section. When this synthetic negative pressure exceeds a predetermined level, the valve is opened and fuel begins to be discharged, maintaining the air-fuel ratio of the mixture constant during the transition from the slow zone to the main zone and in the main zone. be able to.
又、エンジンの停止時やスローゾーンの初期段階等では
、バルブを閉弁させる圧力が働いているので、不必要な
燃料漏れ等が生しることはない。Further, when the engine is stopped or at the initial stage of the slow zone, pressure is applied to close the valve, so unnecessary fuel leakage does not occur.
以下、本発明の一実施例を第１図を中心に説明する。第
１図は第５図と同様な燃料噴射装置の概略断面図である
が、メイン系燃料制御部１３と吸気通路１以外は省略さ
れている。図中、１８はベンチュリ部２の下流側に設け
られたエアバルブ、１９はエアバルブ１８の下流側に設
けられたスロットルバルブ、２０はベンチュリ部２に開
口していてメイン系燃料制御部１３の負圧室５にベンチ
ュリ部２の空気流量に応じた負圧Ｐ１を導入するための
メイン系負圧通路、２０ａはメイン系負圧通路２０内に
設けられた絞り部、２１はエアバルブ１８の最小開度に
おける開口部１８ａ下流側で吸気通路１に開口している
スロー系負圧通路であって、開口部１８ａ下流側の空気
流量に応じた負圧Ｐ２をスロー系燃料制御部の負圧室に
導入せしめるが、図上省略されている。２２は一端がス
ロー系負圧通路２１と連通していて他端が絞り部２０ａ
の下流側でメイン系負圧通路２０に接続されているバイ
パス通路であって、スローゾーンにおいてエアバルブ１
８とスロットルバルブ１９の間に生じた負圧Ｐ２をメイ
ン系負圧通路２０内に導入されるベンチュリ部２の負圧
Ｐ、に印加せしめるのに使用される。２３はバイパス通
路２２に設けられていて負圧Ｐ２のメイン系負圧通路２
０への印加量を調整し得るアジャストスクリュー、２４
は一端が燃料噴射室８の噴射口８ａと接続されていて他
端がスロットルバルブ１９の下流側で吸気通路１に開口
する燃料吐出通路、２５は大気室２６内に設けられてい
て負圧ダイアフラム６を負圧室５側に弾圧する第一スプ
リング、２７は燃圧室９内に設けられていて燃料ダイア
フラム１０を燃料噴射室８側に弾圧する第ニスプリング
である。An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic cross-sectional view of a fuel injection device similar to FIG. 5, but parts other than the main system fuel control section 13 and the intake passage 1 are omitted. In the figure, 18 is an air valve provided on the downstream side of the venturi section 2, 19 is a throttle valve provided on the downstream side of the air valve 18, and 20 is open to the venturi section 2, and the negative pressure of the main system fuel control section 13 is A main system negative pressure passage for introducing negative pressure P1 according to the air flow rate of the venturi section 2 into the chamber 5, 20a is a constriction part provided in the main system negative pressure passage 20, and 21 is a minimum opening degree of the air valve 18. A slow system negative pressure passage that opens into the intake passage 1 on the downstream side of the opening 18a in which negative pressure P2 corresponding to the air flow rate downstream of the opening 18a is introduced into the negative pressure chamber of the slow system fuel control section. However, it is omitted in the diagram. 22 has one end communicating with the slow system negative pressure passage 21 and the other end communicating with the throttle part 20a.
A bypass passage connected to the main system negative pressure passage 20 on the downstream side of the air valve 1 in the slow zone.
8 and the throttle valve 19 is applied to the negative pressure P of the venturi section 2 introduced into the main system negative pressure passage 20. 23 is provided in the bypass passage 22 and is the main system negative pressure passage 2 of negative pressure P2.
Adjustment screw that can adjust the amount of application to 0, 24
is a fuel discharge passage whose one end is connected to the injection port 8a of the fuel injection chamber 8 and whose other end opens to the intake passage 1 on the downstream side of the throttle valve 19; and 25 is a negative pressure diaphragm provided in the atmospheric chamber 26. A first spring 27 presses the fuel diaphragm 10 toward the negative pressure chamber 5, and a second spring 27 is provided in the fuel pressure chamber 9 and presses the fuel diaphragm 10 toward the fuel injection chamber 8.
そして、第一スプリング２５の荷重Ｗ３と第ニスプリン
グ２７の荷重Ｗ、とについて次に示す関係を有するよう
に構成する。即ち、エンジンの停止時等において、
第一スプリング２５の荷重Ｗ３〈ダイアフラムバルブＤ
Ｖの重量Ｗ２＋第ニスプリング２７の荷重Ｗ４
−−−−−〜−− （ｉ ）であ
り、またエンジン作動時においてスローゾーンで負圧室
５に印加される負圧Ｐ１ とＰ２の合成負圧Ｐ３による
圧力Ｗ５が所定の大きさを越えると、
第一スプリング２５の荷重Ｗ３ ＋合成負圧Ｐ３による
圧力Ｗ５〉ダイアフラムバルブＤＶの重量Ｗ２十第ニス
プリング２７の荷重Ｗ ａ −（ｉｉ ）とな
るように構成されている。The load W3 of the first spring 25 and the load W of the second spring 27 are configured to have the following relationship. That is, when the engine is stopped, the load W3 of the first spring 25 <diaphragm valve D
Weight of V W2 + load of second spring 27 W4
−−−−−−−− (i), and the pressure W5 due to the composite negative pressure P3 of the negative pressures P1 and P2 applied to the negative pressure chamber 5 in the slow zone during engine operation exceeds a predetermined level. The load W3 of the first spring 25 + the pressure W5 due to the combined negative pressure P3>the weight W2 of the diaphragm valve DV, the load W2 of the second spring 27 - (ii).
本実施例は以上の構成を有しており、次にその作用を説
明する。The present embodiment has the above configuration, and its operation will be explained next.
まず、エンジン停止時において、メイン系燃料制御部１
３では上記（ｉ）式で示すように第一スプリング２５に
よるバルブ１２ａを開弁させる圧力より、ダイアフラム
バルブＤＶと第ニスプリング２７によるバルブ１２ａを
閉弁させる圧力の方が大きいのでバルブ１２ａは閉弁さ
れている。そして、エンジン始動後、スローゾーンにお
いてはエアバルブ１８の開口部１８ａ、１８ｂを流れる
空気流量に応じた負圧Ｐ２がスロー系燃料制御部の負圧
室に導入されて第２図（ｂ）に実線で示されるスロー系
の空燃比（目標値）を有する混合気がエンジンに供給さ
れるが、同時にこの負圧Ｐ２がバイパス通路２２を介し
てメイン系負圧通路２０内に所定量印加され、ヘンヂュ
リ部２の極めて小さい負圧Ｐ、 と合成されて合成負圧
Ｐ３がメイン系燃料制御部１３の負圧室５に導入される
。しかし、スローゾーンの初期段階においては合成９圧
Ｐ３による圧力Ｗ、が小ざくてバルブ１２ａを閉弁させ
る圧力が開弁させる圧力より大きいために、噴射口８ａ
ばバルブ１２ａによって閉塞されている。そして、空気
流量の増大に応じて負圧Ｐ２も増大して（第３図参照）
負圧室５内の合成負圧Ｐ３が所定の大きさを越えると（
１））式の状態になり、第ニスプリング２７の荷重等に
ょるバルブ１２ａを閉弁させる圧力に抗して負圧ダイア
フラム６が負圧室５側に変位せしめられ、バルブ１２ａ
が開弁せしめられて燃料が燃料吐出通路２４を介して噴
射され、その混合気の空燃比は当初希薄であるが第２図
（Ａ）及び（Ｂ）のメイン系（図（Ｂ）においては破線
部分）で示された曲線を描いて目標値に一致するように
なる。そして、目標値の空燃比を維持した状態でスロー
ゾーンからメインゾーンへ移行し、メインゾーンにおい
てもこの状態が維持される（第２図（Ａ）、（Ｂ）参照
）。又、エンジン停止後の再始動時において、エンジン
キーをＯＮＬ、て燃料ポンプが作動した状態でもエンジ
ンが回転し始める前は（ｉ）弐の状態なのでバルブ１２
ａは閉弁された状態を維持する。First, when the engine is stopped, the main system fuel control section 1
3, as shown in equation (i) above, the pressure that causes the diaphragm valve DV and the second spring 27 to close the valve 12a is greater than the pressure that causes the first spring 25 to open the valve 12a, so the valve 12a is closed. It's being talked about. After the engine starts, in the slow zone, a negative pressure P2 corresponding to the air flow rate flowing through the openings 18a and 18b of the air valve 18 is introduced into the negative pressure chamber of the slow system fuel control section, as shown by the solid line in FIG. 2(b). An air-fuel mixture having a slow system air-fuel ratio (target value) shown by The combined negative pressure P3 is combined with the extremely small negative pressure P of the fuel control section 2 and introduced into the negative pressure chamber 5 of the main system fuel control section 13. However, in the initial stage of the slow zone, the pressure W due to the combined 9 pressure P3 is small and the pressure that closes the valve 12a is greater than the pressure that opens the injection port 8a.
The valve 12a is closed. As the air flow rate increases, the negative pressure P2 also increases (see Figure 3).
When the composite negative pressure P3 in the negative pressure chamber 5 exceeds a predetermined level (
1)), the negative pressure diaphragm 6 is displaced toward the negative pressure chamber 5 against the pressure that causes the valve 12a to close due to the load of the second spring 27, etc., and the valve 12a is closed.
is opened and fuel is injected through the fuel discharge passage 24, and the air-fuel ratio of the mixture is initially lean, but the main system in Figures 2 (A) and (B) (in Figure (B) A curve indicated by the broken line (broken line) is drawn to match the target value. Then, the slow zone shifts to the main zone while maintaining the air-fuel ratio at the target value, and this state is maintained in the main zone as well (see FIGS. 2(A) and 2(B)). Also, when restarting the engine after stopping, even if the engine key is turned ON and the fuel pump is operating, the valve 12 is in the state (i) 2 before the engine starts rotating.
Valve a remains closed.
」二足のように、本実施例によれば、エンジン停止時等
やスローゾーンにおいてメイン系燃料制御部１３の負圧
室５内の合成負圧が所定の大きさを越える前の初期段階
では、バルブ＋２２を閉弁させる圧力が開弁させる圧力
より大きいからエンジン停止時等やスローゾーンの初期
段階等で不必要に燃料が吐出することがなく、またバル
ブ１２ａの開弁開始時の動作も安定的であり、更にスロ
ーゾーンの段階で、空気流量に応じた負圧の所定量をメ
イン系燃料制御部１３の負圧室に印加せしめることによ
り、スローゾーンからメインゾーンへの移行時及びメイ
ンゾーンにおいてメイン系燃料制御部１３によって混合
気の空燃比を一定に維持させることができる。しかも負
圧の制御によって圧力を調整するから、メカニカルなヒ
ステリシスを生しることもない。According to this embodiment, in the initial stage before the combined negative pressure in the negative pressure chamber 5 of the main system fuel control section 13 exceeds a predetermined level, such as when the engine is stopped or in a slow zone, Since the pressure that closes valve +22 is greater than the pressure that opens valve +22, fuel is not discharged unnecessarily when the engine is stopped or at the initial stage of the slow zone, and the operation when valve 12a starts to open is also controlled. Furthermore, by applying a predetermined amount of negative pressure according to the air flow rate to the negative pressure chamber of the main system fuel control section 13 during the slow zone stage, it is possible to In the zone, the air-fuel ratio of the air-fuel mixture can be maintained constant by the main system fuel control section 13. Moreover, since the pressure is adjusted by controlling the negative pressure, no mechanical hysteresis occurs.
尚、本実施例ではエアバルブとして板バルブを用いたが
、ピストンバルブを用いてもよいことは云うまでもない
。In this embodiment, a plate valve is used as the air valve, but it goes without saying that a piston valve may also be used.
又、本実施例では第ニスプリング２７の荷重によってバ
ルブ１２ａの閉弁力を強めるように構成したが、これに
替えて第ニスプリング２７を除去し、第一スプリング２
５の荷重を小さくするようにしてバルブ１２ａの閉弁力
を強めるように構成してもよい。Further, in this embodiment, the closing force of the valve 12a is strengthened by the load of the second spring 27, but instead of this, the second spring 27 is removed and the first spring 2
The valve closing force of the valve 12a may be increased by reducing the load on the valve 12a.
上述の如く、本発明に係る燃料噴射装置の空燃比制御機
構によれば、メイン系燃料制御部によってスローゾーン
からの移行時も含めてメインゾーンの混合気の空燃比を
一定に維持できると共に、エンジンの停止時等やスロー
ゾーンの初期段階における不必要な燃料の吐出を確実に
防止でき、また作動の際にヒステリシスを生しないとい
う、実用上重要な利点を有する。As described above, according to the air-fuel ratio control mechanism of the fuel injection device according to the present invention, the air-fuel ratio of the air-fuel mixture in the main zone can be maintained constant including when transitioning from the slow zone by the main system fuel control section, and It has the practically important advantage of being able to reliably prevent unnecessary fuel discharge when the engine is stopped or at the initial stage of the slow zone, and that hysteresis does not occur during operation.
第１図は本発明に係る燃料噴射装置の空燃比制御機構の
一実施例についての要部断面図、第２図（Ａ）及び（Ｂ
）は第１図の実施例についての空燃比の変化を示す図で
あって、（Ａ）はメイン系燃料制御部によるもの、（Ｂ
）はスロー系及びメイン系燃料制御部によるもの、第３
図は負圧Ｐ２の変化特性を示す図、第４図は従来装置の
原理を示す要部断面図、第５図は同し〈従来装置の全体
を示す概略断面図、第６図（Ａ）乃至（Ｄ）は従来装置
の特性を示す図、第７図は第４図の従来装置を改良した
装置の概略断面図、第８図は（Ａ）乃至（Ｃ）は第７図
に係る装置の特性を示す図である。
■・・・吸気通路、２・・・・ベンチュリ部、５・・・
・負圧室、６ ・・・負圧ダイアフラム、８・・・・燃
料噴射室、８ａ・・・・噴射口、１０・・・・燃料ダイ
アフラム、＋２２・・・・バルブ、１３・・・・メイン
系燃料制御５
御部、１４・・・・スロー系燃料制御部、１８・・・・
エアバルブ、２０・・・・メイン系負圧通路、２１・・
・・スロー系負圧通路、２２・・・・バイパス通路、２
３・・・・アジャストスクリュー、２５・・・・第一ス
プリング、２７・・・・第ニスプリング。
（Ａ）
一−−空ん流ｔ
□空孔流１
１３図
才４図
／
ゝ・１５
Ｄｖ５゜
−λ １２ １
８８９゜
１） 旦 ７，７
□！λ流ｔ
→スロ・ソトルバ′ルワ′聞友FIG. 1 is a sectional view of essential parts of an embodiment of the air-fuel ratio control mechanism of a fuel injection device according to the present invention, and FIGS.
) are diagrams showing changes in the air-fuel ratio for the embodiment shown in FIG.
) is caused by the slow system and main system fuel control section, and the third
The figure shows the change characteristics of negative pressure P2, Figure 4 is a sectional view of the main part showing the principle of the conventional device, and Figure 5 is the same. 7 is a schematic sectional view of a device improved from the conventional device of FIG. 4, and FIG. 8 is a diagram showing the characteristics of the conventional device. FIG. 8 is a diagram showing the device according to FIG. 7. FIG. ■...Intake passage, 2...Venturi section, 5...
-Negative pressure chamber, 6...Negative pressure diaphragm, 8...Fuel injection chamber, 8a...Injection port, 10...Fuel diaphragm, +22...Valve, 13... Main system fuel control section 5, 14... Slow system fuel control section, 18...
Air valve, 20... Main system negative pressure passage, 21...
...Slow system negative pressure passage, 22...Bypass passage, 2
3... Adjustment screw, 25... First spring, 27... Second spring. (A) 1--Void flow t □Void flow 1 13 Figures 4 Figures / ゝ・15 Dv5゜-λ 12 1 889゜1) Dan 7,7 □! λ style t → Suro sotruba'ruwa' listening friend
Claims (2)
る負圧ダイアフラムと、該負圧ダイアフラムの変位に応
じて燃料の噴射口を開閉せしめるバルブを含む、スロー
系燃料制御部とメイン系燃料制御部とを備えた燃料噴射
装置において、 吸気通路のベンチユリ部の負圧を前記メイン系燃料制御
部の負圧室に導入せしめるメイン系負圧通路と、 エアバルブの下流側の負圧を前記スロー系燃料制御部の
負圧室に導入せしめるスロー系負圧通路と、 前記メイン系負圧通路とスロー系負圧通路とを接続せし
めるバイパス通路と、 該バイパス通路に設けられていて前記スロー系負圧通路
からメイン系負圧通路へ印加される負圧の印加量を調整
し得る調整手段と、 を備えていて、前記メイン系燃料制御部によってスロー
ゾーンからメインゾーンへの移行時とメインゾーンにお
ける混合気の空燃比を一定に制御せしめるようにしたこ
とを特徴とする空燃比制御機構。(1) A slow system fuel control unit including a negative pressure diaphragm that partitions a negative pressure chamber into which negative pressure according to the air flow rate is introduced, and a valve that opens and closes a fuel injection port according to the displacement of the negative pressure diaphragm. a main system fuel control section; a main system negative pressure passage that introduces negative pressure in a bench lily section of the intake passage into the negative pressure chamber of the main system fuel control section; and a negative pressure downstream of the air valve. a slow system negative pressure passage that allows the slow system negative pressure passage to be introduced into the negative pressure chamber of the slow system fuel control section; a bypass passage that connects the main system negative pressure passage and the slow system negative pressure passage; an adjustment means capable of adjusting the amount of negative pressure applied from the slow system negative pressure passage to the main system negative pressure passage; An air-fuel ratio control mechanism characterized in that the air-fuel ratio of an air-fuel mixture in a main zone is controlled to be constant.
負圧室に導入せしめられる負圧が所定の大きさを越える
までは、前記バルブを閉弁せしめる圧力が、該バルブを
開弁せしめる圧力よりも大きいように弾性部材を配置し
たことを特徴とする特許請求の範囲（１）に記載の空燃
比制御機構。(2) Until the negative pressure introduced into the negative pressure chamber of the main system fuel control section in the slow zone exceeds a predetermined level, the pressure that closes the valve is lower than the pressure that opens the valve. The air-fuel ratio control mechanism according to claim (1), characterized in that the elastic member is arranged so as to be large.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63084336A JPH01257761A (en) | 1988-04-06 | 1988-04-06 | Mechanism for controlling air-fuel ratio of fuel injection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63084336A JPH01257761A (en) | 1988-04-06 | 1988-04-06 | Mechanism for controlling air-fuel ratio of fuel injection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01257761A true JPH01257761A (en) | 1989-10-13 |
Family
ID=13827664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63084336A Pending JPH01257761A (en) | 1988-04-06 | 1988-04-06 | Mechanism for controlling air-fuel ratio of fuel injection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01257761A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0424565A1 (en) * | 1989-10-25 | 1991-05-02 | Mikuni Kogyo Kabushiki Kaisha | Air-fuel ratio control device for injection carburetors |
-
1988
- 1988-04-06 JP JP63084336A patent/JPH01257761A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0424565A1 (en) * | 1989-10-25 | 1991-05-02 | Mikuni Kogyo Kabushiki Kaisha | Air-fuel ratio control device for injection carburetors |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH03229948A (en) | Fuel control device for engine | |
| JPH01257761A (en) | Mechanism for controlling air-fuel ratio of fuel injection device | |
| JPH01262331A (en) | Air-fuel ratio control mechanism of fuel injection equipment | |
| JPH02238142A (en) | Fuel control device of engine with supercharger | |
| JPS6111462Y2 (en) | ||
| US5817257A (en) | Fuel metering system | |
| JPS6154942B2 (en) | ||
| JPS593177Y2 (en) | Air flow rate detection device for internal combustion engine intake system | |
| JPS6130139B2 (en) | ||
| JPS6339397Y2 (en) | ||
| JPS6221726Y2 (en) | ||
| JPS636735B2 (en) | ||
| JPS6014910Y2 (en) | engine carburetor | |
| JPS63192959A (en) | Fuel pressure control device for fuel injection type engine | |
| JPS5965527A (en) | Fuel injector for engine | |
| JPS59138735A (en) | Fuel feeder for engine | |
| JPS61283720A (en) | Suction device for diesel engine | |
| JPS6055690B2 (en) | Engine idle speed control device | |
| JPS597029B2 (en) | Ignition advance control device for internal combustion engines | |
| JPH0436025A (en) | Boost pressure control valve device of internal combustion engine | |
| JPS6321355A (en) | Air bleed device for variable venturi carburetor | |
| JPH07103075A (en) | Starting auxiliary device for gas engine | |
| JPS6217318A (en) | Air intake device of engine | |
| JPS5845592B2 (en) | Air-fuel ratio control device for internal combustion engines | |
| JPS5891345A (en) | Control device for engine |