JPH0615858B2 - Exhaust gas recirculation control system for engines with fuel injection system - Google Patents

Exhaust gas recirculation control system for engines with fuel injection system

Info

Publication number
JPH0615858B2
JPH0615858B2 JP59140112A JP14011284A JPH0615858B2 JP H0615858 B2 JPH0615858 B2 JP H0615858B2 JP 59140112 A JP59140112 A JP 59140112A JP 14011284 A JP14011284 A JP 14011284A JP H0615858 B2 JPH0615858 B2 JP H0615858B2
Authority
JP
Japan
Prior art keywords
exhaust gas
valve
intake
cylinder
fuel injection
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 - Lifetime
Application number
JP59140112A
Other languages
Japanese (ja)
Other versions
JPS6119961A (en
Inventor
正志 丸原
稔益 田中
正法 三角
彰士 長尾
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mazda Motor Corp
Original Assignee
Mazda Motor Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mazda Motor Corp filed Critical Mazda Motor Corp
Priority to JP59140112A priority Critical patent/JPH0615858B2/en
Publication of JPS6119961A publication Critical patent/JPS6119961A/en
Publication of JPH0615858B2 publication Critical patent/JPH0615858B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • F02B17/00—Engines characterised by means for effecting stratification of charge in cylinders
    • 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
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/17—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system
    • F02M26/20—Feeding recirculated exhaust gases directly into the combustion chambers or into the intake runners
    • 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
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/39—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with two or more EGR valves disposed in series
    • 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
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/40—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with timing means in the recirculation passage, e.g. cyclically operating valves or regenerators; with arrangements involving pressure pulsations
    • 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
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/65—Constructional details of EGR valves
    • F02M26/70—Flap valves; Rotary valves; Sliding valves; Resilient valves
    • 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
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/36—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with means for adding fluids other than exhaust gas to the recirculation passage; with reformers

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust-Gas Circulating Devices (AREA)

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、各シリンダに対し同時に燃料を噴射供給する
ようにした燃料噴射装置付エンジンにおいて、排気の一
部を吸気系に還流させる排気還流のタイミングを制御す
るようにした排気還流制御装置に関するものである。The present invention relates to an exhaust gas recirculation system for recirculating a part of exhaust gas to an intake system in an engine with a fuel injection device that simultaneously injects and supplies fuel to each cylinder. The present invention relates to an exhaust gas recirculation control device for controlling the timing of the above.

（従来技術） 一般に、エンジンに排気還流を行う場合、各気筒の吸気
行程時に、排気の一部を吸気弁の開作動に基づいて燃焼
室に還流供給するようになされている。例えば特開昭５
７−１４３１２６号公報に開示されるものでは、主吸気
通路よりも通路面積の小さい軽負荷用の副吸気通路に排
気還流通路を開口して、エンジンの低回転・低負荷時に
は、排気の一部を吸気弁の開作動に伴い排気還流通路か
ら上記軽負荷用の副吸気通路を経てシリンダ上部から燃
焼室に流入供給するようになされている。(Prior Art) Generally, when exhaust gas is recirculated to an engine, a part of exhaust gas is recirculated to a combustion chamber based on an opening operation of an intake valve during an intake stroke of each cylinder. For example, JP-A-5
In the one disclosed in JP-A 7-143126, an exhaust gas recirculation passage is opened in a sub-intake passage for a light load, which has a passage area smaller than that of the main intake passage, and a part of the exhaust gas is discharged when the engine is running at a low speed and a low load. With the opening operation of the intake valve, the gas is supplied from the exhaust gas recirculation passage to the combustion chamber from the upper portion of the cylinder through the light load auxiliary intake passage.

（発明が解決しようとする問題点） ところで、通常の燃料噴射装置付エンジン、すなわち各
シリンダが吸気行程にあるか否かに関係なく所定のクラ
ンク角度で燃料噴射弁から各シリンダに対して同時に燃
料を噴射供給するようにしたエンジンにおいては、その
低中負荷時、吸気行程前に燃料噴射弁から噴射された燃
料が液滴となって吸気弁直上流の吸気通路に滞留し、吸
気弁が開いて吸気行程になるとその初期に上記液滴燃料
がそのまま燃焼室内に流入してその下部に壁面に付着す
ることにより、燃焼室内の下部には気化霧化の不十分な
混合気が偏在分布する。そして、燃焼性の改善のために
シリンダ内に吸入される混合気にスワール（渦流）が生
成されていると、そのスワールによって上記混合気の偏
在分布が強力に維持され、混合気の燃焼室内上部への拡
散がスムーズに行われず、その結果、混合気の燃焼効率
が悪くなって燃費の低減を良好に図り得ないという問題
があった。(Problems to be Solved by the Invention) By the way, a normal engine with a fuel injection device, that is, fuel is simultaneously injected from a fuel injection valve to each cylinder at a predetermined crank angle regardless of whether each cylinder is in an intake stroke or not. In a low-to-medium load engine, the fuel injected from the fuel injection valve before the intake stroke becomes droplets and stays in the intake passage immediately upstream of the intake valve, and the intake valve opens. At the beginning of the intake stroke, the droplet fuel flows into the combustion chamber as it is at the initial stage and adheres to the wall surface at the lower portion thereof, so that an insufficiently vaporized mixture is unevenly distributed in the lower portion of the combustion chamber. When a swirl (vortex flow) is generated in the air-fuel mixture that is drawn into the cylinder to improve combustibility, the swirl maintains a strong uneven distribution of the air-fuel mixture, and the upper part of the air-fuel mixture combustion chamber. However, there is a problem in that the combustion efficiency of the air-fuel mixture is deteriorated and the fuel consumption cannot be reduced satisfactorily.

また、このように空燃比のリッチな混合気が燃焼室内下
部に偏在するため、上記従来例のように、吸気弁の開弁
に基づいて燃焼室内に排気を還流させて、燃焼室内の全
体に還流排気を分布させると、上記燃焼室内下部のリッ
チな混合気を狙ってその燃焼温度を有効に低下させるこ
とが困難となり、ＮＯｘを効果的に低減できない難があ
る。Further, since the air-fuel ratio rich air-fuel mixture is unevenly distributed in the lower part of the combustion chamber in this manner, exhaust gas is recirculated into the combustion chamber based on the opening of the intake valve as in the above-mentioned conventional example, so that the entire combustion chamber is covered. When the recirculated exhaust gas is distributed, it becomes difficult to effectively lower the combustion temperature aiming at the rich air-fuel mixture in the lower portion of the combustion chamber, and it is difficult to effectively reduce NOx.

そこで、本発明の目的は、上記した燃料噴射装置付エン
ジンにおいて、その低中負荷時に、排気を燃焼室内に還
流させる排気還流の時期を吸気行程の特定の時期に設定
することにより、燃料液滴の流入によって燃焼室内下部
に偏在した混合気を還流排気の持つガス熱により加熱し
てその気化霧化を促進するとともに、上記混合気の燃焼
温度を効率良く低下させるようにすることにある。Therefore, an object of the present invention is to provide fuel droplets by setting the timing of exhaust gas recirculation in which the exhaust gas is recirculated into the combustion chamber at a specific timing of the intake stroke in the engine with a fuel injection device described above, at low and medium loads. Is to heat the air-fuel mixture unevenly distributed in the lower part of the combustion chamber by the gas heat of the recirculation exhaust gas to accelerate the vaporization and atomization of the air-fuel mixture, and to efficiently lower the combustion temperature of the air-fuel mixture.

（問題点を解決するための手段） 上記目的を達成するため、本発明の解決手段は、シリン
ダ内に供給される混合気にスワールを生成するスワール
生成機構と、燃料噴射弁から各シリンダに対して同時に
燃料を噴射供給する燃料噴射装置と、排気の一部をシリ
ンダ内に供給する排気供給手段とを備えたエンジンにお
いて、その少なくとも低負荷時、吸気行程の初期に上記
排気供給手段から排気を供給させる排気供給制御手段を
設けたものである。(Means for Solving Problems) In order to achieve the above-mentioned object, a solution means of the present invention is a swirl generating mechanism for generating swirl in a mixture gas supplied into a cylinder, and a fuel injection valve for each cylinder. In the engine provided with a fuel injection device for simultaneously injecting and supplying fuel, and an exhaust gas supply means for supplying a part of the exhaust gas into the cylinder, at least when the load is low, the exhaust gas is discharged from the exhaust gas supply means at the beginning of the intake stroke. An exhaust gas supply control means for supplying the gas is provided.

（作用） 上記構成により、本発明では、燃料噴射装置付エンジン
の少なくとも低負荷時には、その吸気行程の初期に排気
還流を行って、燃焼室内下部に偏在分布する混合気内に
集中滴に還流排気を混入させ、該還流排気のガス熱によ
って混合気を加熱してその気化霧化を促進し燃焼効率を
向上させるとともに、不活性な還流排気によって上記混
合気の燃焼温度をも効率良く低下させるようにしたもの
である。(Operation) With the above configuration, in the present invention, at least when the load of the engine with the fuel injection device is low, exhaust gas recirculation is performed at the beginning of the intake stroke thereof, and the exhaust gas is recirculated to concentrated droplets in the air-fuel mixture unevenly distributed in the lower portion of the combustion chamber. To improve the combustion efficiency by heating the air-fuel mixture by the gas heat of the recirculation exhaust gas to promote the vaporization and atomization of the air-fuel mixture, and also to effectively lower the combustion temperature of the air-fuel mixture by the inert recirculation exhaust gas. It is the one.

（実施例） 以下、本発明の実施例を図面に基づいて詳細に説明す
る。(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

第１図ないし第３図において、１はシリンダブロック２
およびシリンダヘッド３によって形成されたシリンダ４
を有するエンジン、５はシリンダ４内を往復動するピス
トン、６は該ピストン５によってシリンダ４内に区画形
成された燃焼室、７は燃焼室６内に吸気を供給する吸気
通路、８は燃焼室６内の排気を排出する排気通路、９は
吸気通路７の燃焼室６への開口部７ａを開閉する吸気
弁、１０は排気通路８の燃焼室６への開口部８ａを開閉
する排気弁１０、１１はシリンダ４内の燃焼室６上部に
配設された点火栓である。In FIGS. 1 to 3, 1 is a cylinder block 2
And a cylinder 4 formed by the cylinder head 3
An engine having 5; a piston that reciprocates in the cylinder 4; 6 a combustion chamber defined by the piston 5 in the cylinder 4; 7 an intake passage for supplying intake air into the combustion chamber 6; 8 a combustion chamber An exhaust passage for discharging the exhaust gas in 6; an intake valve 9 for opening and closing an opening 7a of the intake passage 7 to the combustion chamber 6; and an exhaust valve 10 for opening and closing an opening 8a of the exhaust passage 8 to the combustion chamber 6. , 11 are spark plugs arranged above the combustion chamber 6 in the cylinder 4.

上記吸気通路７には、上流側から順に、燃焼室６に吸入
される吸気空気量を検出するエアフローメータ１２と、
同吸入空気量をコントロールするスロットルバルブ１３
と、吸気の脈動を吸収するサージタンク１４とが配設さ
れ、吸気通路７の上流端はエアクリーナ１５に接続され
ている。In the intake passage 7, from the upstream side, an air flow meter 12 for detecting the amount of intake air taken into the combustion chamber 6,
The throttle valve 13 that controls the intake air amount
And a surge tank 14 that absorbs the pulsation of intake air are arranged, and the upstream end of the intake passage 7 is connected to an air cleaner 15.

また、第２図および第３図に拡大詳示するように、上記
サージタンク１４下流の吸気通路７は隔壁１６によって
１次側吸気通路７ｂと２次側吸気通路７ｃとに分けら
れ、上記１次側吸気通路７ｂは通路面積が２次側吸気通
路７ｃよりも小さく設定され、かつ１次側吸気通路７ｂ
の下流端は吸気弁９よりも僅かに上流側の吸気通路７に
シリンダ４の円周方向に向かうように開口されており、
１次側吸気通路７ｂを流れる吸気（混合気）をその流速
を速めながらエンジン４内に円周方向に導入することに
より、シリンダ４内に吸気のスワールＫを生成するよう
にしたスワール生成機構１７が構成されている。Further, as shown in enlarged detail in FIGS. 2 and 3, the intake passage 7 downstream of the surge tank 14 is divided by a partition wall 16 into a primary-side intake passage 7b and a secondary-side intake passage 7c. The passage area of the secondary intake passage 7b is set smaller than that of the secondary intake passage 7c, and the primary intake passage 7b is provided.
Has a downstream end opened in the intake passage 7 slightly upstream of the intake valve 9 in the circumferential direction of the cylinder 4.
A swirl generation mechanism 17 configured to generate the swirl K of the intake air in the cylinder 4 by introducing the intake air (mixture) flowing in the primary side intake passage 7b into the engine 4 in the circumferential direction while increasing the flow velocity. Is configured.

尚、上記２次側吸気通路７ｃの下流端はシリンダ４の中
心線と略平行な方向つまりピストン５上面に向かって開
口しており、この２次側吸気通路７ｃを通ってシリンダ
４に流入する吸気にスワールＫを付与しないようにして
いる。また、上記２次側吸気通路７ｃの途中には２次側
吸気通路７ｃを開閉してスワールＫの強度を制御するス
ワール制御弁１８が配設され、該スワール制御弁１８は
図示しないアクチュエータに駆動連結されていて、該ア
クチュエータによってエンジン１の回転数と負荷状態に
応じて作動制御され、エンジン１が低速低負荷領域にあ
るときには、スワール制御弁１８が閉じることにより、
吸気を１次側吸気通路７ｂからシリンダ４内に流入させ
てスワールＲの強度を強め、エンジン１が高速高負荷領
域に移行するのに伴い、スワール制御弁１８の開度が増
大することにより、２次側吸気通路７ｃからの吸気の流
入比率を高めて、シリンダ４内のスワールＫの強度を弱
めるようになされている。The downstream end of the secondary intake passage 7c opens in a direction substantially parallel to the center line of the cylinder 4, that is, toward the upper surface of the piston 5, and flows into the cylinder 4 through the secondary intake passage 7c. The swirl K is not added to the intake air. A swirl control valve 18 for controlling the strength of the swirl K by opening and closing the secondary intake passage 7c is disposed in the middle of the secondary intake passage 7c, and the swirl control valve 18 is driven by an actuator (not shown). When the engine 1 is in the low speed and low load region, the swirl control valve 18 is closed so that the operation is controlled by the actuator according to the rotation speed and the load state of the engine 1.
By making the intake air flow into the cylinder 4 from the primary side intake passage 7b to increase the strength of the swirl R and increase the opening degree of the swirl control valve 18 as the engine 1 shifts to the high speed and high load region, The inflow ratio of the intake air from the secondary side intake passage 7c is increased, and the strength of the swirl K in the cylinder 4 is weakened.

また、上記スワール制御弁１８下流の２次側吸気通路７
ｃには燃料噴射弁１９が燃料を燃焼室６に向けて噴射す
るように配設され、該燃料噴射弁１９には一定の燃料圧
力が印加されており、燃料噴射弁１９は入力されるパル
ス信号のパルス幅に応じて開弁時間を変えて燃料噴射量
を変化させるものである。In addition, the secondary side intake passage 7 downstream of the swirl control valve 18
A fuel injection valve 19 is disposed at c so as to inject fuel toward the combustion chamber 6, a constant fuel pressure is applied to the fuel injection valve 19, and the fuel injection valve 19 receives an input pulse. The valve opening time is changed according to the pulse width of the signal to change the fuel injection amount.

一方、上記排気通路８の途中には排気を浄化するための
触媒２０が配設され、該触媒２０上流の排気通路８には
排気還流通路２１の上流端が開口され、該排気還流通路
２１の下流端は上記吸気通路７の１次側吸気通路７ｂに
開口されている。また、上記排気還流通路２１の途中に
は排気還流弁２２が配設され、該排気還流弁２２は、排
気還流通路２１を絞り開閉する弁体２３と、該弁体２３
に駆動連結されたダイヤフラム２４と、該ダイヤフラム
２４によって区画形成された負圧室２５と、該負圧室２
５内に縮装され、ダイヤフラム２４を弁体２３の閉弁方
向に付勢するスプリング２６とを備え、上記負圧室２５
はデューテイバルブ２７を介設した負圧通路２８を介し
て負圧源（図示せず）に連通されている。而して、排気
通路８を流れる排気の一部を排気還流弁２２によって流
量制御しながら吸気通路７の１次側吸気通路７ｂに流入
させてシリンダ４の燃焼室６に供給するようにした排気
供給手段２９が構成されている。On the other hand, a catalyst 20 for purifying the exhaust gas is disposed in the middle of the exhaust passage 8, and an upstream end of an exhaust gas recirculation passage 21 is opened in the exhaust passage 8 upstream of the catalyst 20. The downstream end is opened to the primary side intake passage 7b of the intake passage 7. Further, an exhaust gas recirculation valve 22 is disposed in the middle of the exhaust gas recirculation passage 21, and the exhaust gas recirculation valve 22 has a valve body 23 that throttles and opens the exhaust gas recirculation passage 21 and the valve body 23.
A diaphragm 24 that is drivingly connected to the negative pressure chamber 25, a negative pressure chamber 25 defined by the diaphragm 24, and the negative pressure chamber 2
5 and a spring 26 for urging the diaphragm 24 in the valve closing direction of the valve body 23.
Is communicated with a negative pressure source (not shown) via a negative pressure passage 28 provided with a duty valve 27. Thus, a part of the exhaust gas flowing through the exhaust passage 8 is made to flow into the primary-side intake passage 7b of the intake passage 7 and supplied to the combustion chamber 6 of the cylinder 4 while controlling the flow rate by the exhaust gas recirculation valve 22. Supply means 29 is configured.

さらに、上記排気還流弁２２下流の排気還流通路２１に
は該排気還流通路２１を開閉するロータリバルブ３０が
配設され、該ロータリバルブ３０は、その開弁時期を調
整するバルブタイミング可変機構３１を介してエンジン
１に駆動連結されており、エンジン１の回転に同期して
ロータリバルブ３０を駆動回転させるようになされてい
る。Further, a rotary valve 30 for opening and closing the exhaust gas recirculation passage 21 is disposed in the exhaust gas recirculation passage 21 downstream of the exhaust gas recirculation valve 22, and the rotary valve 30 has a valve timing variable mechanism 31 for adjusting the valve opening timing. The rotary valve 30 is drivingly connected to the engine 1 via the rotary valve 30 in synchronization with the rotation of the engine 1.

そして、上記燃料噴射弁１９、排気還流弁２２制御用の
デューテイバルブ２７およびロータリバルブ３０制御用
の可変機構３１はＣＰＵを内蔵したコントローラ３２に
よって作動制御される。該コントローラ３２には、上記
スロットルバルブ１３のバルブ開度を検出するスロット
ルセンサ３３、ディストリビュータ３４の回転角からエ
ンジン１のクランク角を検出するクランク角センサ３５
および上記エアフローメータ１２の各出力が入力されて
おり、該コントローラ３２により、上記クランク角セン
サ３５からのクランク角信号およびエアフローメータ１
２からのエアフロー信号に基づいてエンジン１の回転数
および負荷状態を検出し、それを予め設定記憶されてい
る燃料マップと照合して基本燃料噴射量を決定するとと
もに、該基本燃料噴射量をスロットルセンサ３３からの
スロットル信号に応じて補正して実行燃料噴射量を決定
し、該実行燃料噴射量に対応したバルス幅の信号をエン
ジン１の所定のクランク角時期に燃料噴射弁１９に出力
して該燃料噴射弁１９から各シリンダ４に対して同時に
燃焼に必要な燃料を噴射供給するようにした燃料噴射装
置３６が構成されている。The operation of the variable valve 31 for controlling the fuel injection valve 19, the duty valve 27 for controlling the exhaust gas recirculation valve 22 and the rotary valve 30 is controlled by a controller 32 having a built-in CPU. The controller 32 includes a throttle sensor 33 for detecting the valve opening of the throttle valve 13 and a crank angle sensor 35 for detecting the crank angle of the engine 1 from the rotation angle of the distributor 34.
The respective outputs of the air flow meter 12 are input, and the controller 32 causes the crank angle signal from the crank angle sensor 35 and the air flow meter 1 to be input.
The engine speed and the load state of the engine 1 are detected based on the airflow signal from the engine 2, and the basic fuel injection amount is determined by collating the detected engine speed with a preset fuel map and the basic fuel injection amount is throttled. The execution fuel injection amount is determined by making a correction according to the throttle signal from the sensor 33, and a signal of the pulse width corresponding to the execution fuel injection amount is output to the fuel injection valve 19 at a predetermined crank angle timing of the engine 1. A fuel injection device 36 is configured so that fuel required for combustion is simultaneously injected and supplied from the fuel injection valve 19 to each cylinder 4.

また、上記コントローラ３２により、エンジン１の負荷
状態に応じて排気還流弁２２の弁開度およびロータリバ
ルブ３０の開弁時期を制御し、エンジン１が低中負荷域
にあるときには、排気還流弁２２を開くとともに、各シ
リンダ４の吸気行程の初期にロータリバルブ３０を開弁
させることにより、第４図に示すように吸気行程の初期
に排気供給手段２９により排気を供給させ、一方、エン
ジン１が高負荷域に移ると排気還流弁２２を閉弁させる
ことにより、排気の供給を停止させるようにした排気供
給制御手段３７が構成されている。Further, the controller 32 controls the valve opening degree of the exhaust gas recirculation valve 22 and the valve opening timing of the rotary valve 30 according to the load state of the engine 1, and when the engine 1 is in the low to medium load range, the exhaust gas recirculation valve 22 is controlled. And the rotary valve 30 is opened at the beginning of the intake stroke of each cylinder 4, the exhaust gas is supplied by the exhaust gas supply means 29 at the beginning of the intake stroke, as shown in FIG. The exhaust gas supply control means 37 is configured to stop the supply of exhaust gas by closing the exhaust gas recirculation valve 22 when shifting to the high load region.

尚、その場合、吸気行程において、吸気弁９の開弁によ
り混合気が実質的に燃焼室６内に吸入される時期よりも
前にロータリバルブ３０を開弁させると、排気還流通路
２１により供給された還流排気の一部が吸気弁９上流の
吸気通路７に溜り、この還流排気は、先ず吸気弁９の開
弁に伴う燃焼室６内の排気の吸気通路７への吹返しを受
けて排気還流通路２１の下流端開口部よりも上流側の吸
気通路７へ逆流し、その後混合気の吸入が始まると該混
合気と共に吸気行程の後半に燃焼室６内に吸入されるよ
うになり、つまり還流排気が燃焼室６内上部にも拡散分
布することになる。このことを避けるために、第４図に
示すように、排気弁１０および吸気弁９が共に開弁した
状態のオーバーラップ期間の中期と排気弁１０の閉弁時
期との間の時期にロータリバルブ３０を開弁させるよう
に設定するのが好ましい。In that case, in the intake stroke, if the rotary valve 30 is opened before the time when the air-fuel mixture is substantially sucked into the combustion chamber 6 by opening the intake valve 9, the exhaust gas recirculation passage 21 supplies it. A part of the recirculated exhaust gas collected is collected in the intake passage 7 upstream of the intake valve 9, and the recirculated exhaust gas is first subjected to the blowback of the exhaust gas in the combustion chamber 6 to the intake passage 7 due to the opening of the intake valve 9. When the mixture flows back into the intake passage 7 on the upstream side of the downstream end opening of the exhaust gas recirculation passage 21 and thereafter the intake of the air-fuel mixture begins, the air-fuel mixture is sucked into the combustion chamber 6 in the latter half of the intake stroke. That is, the recirculated exhaust gas is also diffused and distributed in the upper part of the combustion chamber 6. In order to avoid this, as shown in FIG. 4, the rotary valve is set at a timing between the middle of the overlap period in which both the exhaust valve 10 and the intake valve 9 are open and the closing timing of the exhaust valve 10. It is preferable to set so that 30 is opened.

したがって、上記実施例においては、エンジン１の低中
負荷時に、各シリンダ４の吸気行程前に燃料噴射弁１９
から噴射された燃料が液滴状態となって吸気弁９直上流
の吸気通路７に滞留し、吸気弁９が開いて吸気行程が開
始されるとその初期に上記液滴燃料はそのまま燃焼室６
内に吸入されてその下部の壁面に付着し、この燃料液滴
により第５図に示すように燃焼室６内下部に気化霧化が
不十分でリッチな混合気が偏在分布され、この混合気の
偏在分布はスワール生成機構１７によって生成されたス
ワールＫによって強力に持続される。しかし、その一方
で、エンジン１が上記低中負荷域にあるときには、コン
トローラ３２の作動により排気還流弁２２がエンジン負
荷に対応した開度だけ開弁して、排気の一部をシリンダ
４の燃焼室６内に供給可能な状態となるとともに、シリ
ンダ４の吸気行程初期にロータリバルブ３０が開弁し、
このロータリバルブ３０の開弁により上記排気還流弁２
２にて流量制御された排気が吸気行程の初期に吸気通路
７の１次側吸気通路７ｂに流入してシリンダ４の燃焼室
６内に還流されるため、この還流排気は上記燃焼室６内
下部に偏在する気化霧化が不十分の混合気内に集中的に
供給混入されることとなる。その結果、この還流排気の
持つガス熱により上記燃焼室６内下部の混合気が加熱さ
れてその気化霧化が促進され、よって燃焼効率の上昇に
より燃費を低減することができる。Therefore, in the above embodiment, when the engine 1 has a low and medium load, the fuel injection valve 19 is provided before the intake stroke of each cylinder 4.
The fuel injected from the fuel cell becomes a droplet state and stays in the intake passage 7 immediately upstream of the intake valve 9. When the intake valve 9 opens and the intake stroke starts, the droplet fuel remains as it is at the beginning of the combustion chamber 6.
The fuel mixture is sucked into the inside of the combustion chamber 6 and adheres to the wall surface of the lower portion thereof. As a result, the fuel droplets cause an uneven distribution of a rich mixture due to insufficient vaporization and atomization in the lower portion of the combustion chamber 6, as shown in FIG. The uneven distribution of is strongly maintained by the swirl K generated by the swirl generation mechanism 17. However, on the other hand, when the engine 1 is in the low and medium load range, the exhaust gas recirculation valve 22 is opened by the operation of the controller 32 by an opening degree corresponding to the engine load, and a part of the exhaust gas is burned in the cylinder 4. While the chamber 6 can be supplied into the chamber 6, the rotary valve 30 opens at the beginning of the intake stroke of the cylinder 4,
The exhaust gas recirculation valve 2 is opened by opening the rotary valve 30.
The exhaust gas whose flow rate is controlled by 2 flows into the primary side intake passage 7b of the intake passage 7 and is recirculated into the combustion chamber 6 of the cylinder 4 at the beginning of the intake stroke. It is concentratedly supplied and mixed in the air-fuel mixture that is unevenly distributed in the lower part and has insufficient vaporization and atomization. As a result, the gas heat of the recirculated exhaust gas heats the air-fuel mixture in the lower part of the combustion chamber 6 to promote the vaporization and atomization thereof, thereby increasing the combustion efficiency and reducing fuel consumption.

また、リッチな混合気の燃焼により燃焼温度が高くなる
燃焼室６内下部領域に不活性な還流排気が集中的に供給
されるので、最少量の還流排気でもって混合気の燃焼温
度を有効に低下させることができ、よってＮＯｘを効果
的に低減することができる。Further, since the inert recirculation exhaust gas is intensively supplied to the lower region in the combustion chamber 6 where the combustion temperature rises due to the combustion of the rich air-fuel mixture, the combustion temperature of the air-fuel mixture becomes effective with the minimum amount of recirculation exhaust gas. Therefore, NOx can be effectively reduced.

（発明の効果） 以上説明したように、本発明によれば、燃料を各シリン
ダに対して同時に噴射供給する燃料噴射装置付エンジン
の少なくとも低負荷時に、その吸気行程の初期に燃焼室
内に排気を還流させるようにしたことにより、吸気行程
初期の燃焼液滴の流入によって燃焼室内下部に偏在した
混合気を還流排気のガス熱により加熱してその気化霧化
を促進でき、燃焼効率の向上によりエンジンの燃費低減
を図ることができるとともに、上記混合気の燃焼温度を
不活性な還流排気によって効率良く低下させて効果的な
ＮＯｘの低減を図ることができるものである。(Effects of the Invention) As described above, according to the present invention, exhaust gas is introduced into the combustion chamber at the beginning of the intake stroke at least when the engine with a fuel injection device that simultaneously supplies fuel to each cylinder supplies a low load. By performing the recirculation, the air-fuel mixture unevenly distributed in the lower part of the combustion chamber due to the inflow of the combustion droplets in the early stage of the intake stroke can be heated by the gas heat of the recirculation exhaust gas to promote the vaporization and atomization thereof, and the combustion efficiency improves the engine. The fuel consumption can be reduced, and the combustion temperature of the air-fuel mixture can be efficiently reduced by the inert recirculation exhaust gas to effectively reduce NOx.

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

図面は本発明の実施例を示すもので、第１図は全体概略
構成図、第２図はエンジンの要部縦断面図、第３図はシ
リンダヘッドの底面図、第４図は吸気行程における排気
還流のタイミングを示す説明図、第５図は吸気行程終期
のシリンダ内のガス組成を示す説明図である。 １……エンジン、４……シリンダ、６……燃焼室、７…
…吸気通路、１１……点火栓、１２……エアフローメー
タ、１３……スロットルバルブ、１７……スワール生成
機構、１９……燃料噴射弁、２１……排気還流通路、２
２……排気還流弁、２９……排気供給手段、３０……ロ
ータリバルブ、３２……コントローラ、３３……スロッ
トルセンサ、３５……クランク角センサ、３６……燃料
噴射装置、３７……排気供給制御手段。The drawings show an embodiment of the present invention. FIG. 1 is an overall schematic configuration diagram, FIG. 2 is a longitudinal sectional view of an essential part of an engine, FIG. 3 is a bottom view of a cylinder head, and FIG. 4 is an intake stroke. FIG. 5 is an explanatory diagram showing the timing of exhaust gas recirculation, and FIG. 5 is an explanatory diagram showing the gas composition in the cylinder at the end of the intake stroke. 1 ... Engine, 4 ... Cylinder, 6 ... Combustion chamber, 7 ...
... intake passage, 11 ... spark plug, 12 ... air flow meter, 13 ... throttle valve, 17 ... swirl generating mechanism, 19 ... fuel injection valve, 21 ... exhaust gas recirculation passage, 2
2 ... Exhaust gas recirculation valve, 29 ... Exhaust gas supply means, 30 ... Rotary valve, 32 ... Controller, 33 ... Throttle sensor, 35 ... Crank angle sensor, 36 ... Fuel injection device, 37 ... Exhaust gas supply Control means.

フロントページの続き (72)発明者 長尾 彰士 広島県安芸郡府中町新地３番１号 マツダ 株式会社内 (56)参考文献 特開 昭56−156452（ＪＰ，Ａ)Front page continued (72) Inventor Akio Nagao 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) Reference JP-A-56-156452 (JP, A)

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】シリンダ内に供給される混合気にスワール
を生成するスワール生成機構と、燃料噴射弁から各シリ
ンダに対して同時に燃料を噴射供給する燃料噴射装置
と、排気の一部をシリンダ内に供給する排気供給手段と
を備えたエンジンにおいて、少なくとも低負荷時に吸気
行程の初期に上記排気供給手段から排気を供給させる排
気供給制御手段を設けたことを特徴とする燃料噴射装置
付エンジンの排気還流制御装置。1. A swirl generating mechanism for generating swirl in a mixture gas supplied to a cylinder, a fuel injection device for simultaneously injecting fuel from a fuel injection valve to each cylinder, and a part of exhaust gas in the cylinder. An exhaust gas supply control means for supplying exhaust gas from the exhaust gas supply means at least in the early stage of the intake stroke at least when the load is low. Reflux control device.
JP59140112A 1984-07-05 1984-07-05 Exhaust gas recirculation control system for engines with fuel injection system Expired - Lifetime JPH0615858B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59140112A JPH0615858B2 (en) 1984-07-05 1984-07-05 Exhaust gas recirculation control system for engines with fuel injection system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59140112A JPH0615858B2 (en) 1984-07-05 1984-07-05 Exhaust gas recirculation control system for engines with fuel injection system

Publications (2)

Publication Number Publication Date
JPS6119961A JPS6119961A (en) 1986-01-28
JPH0615858B2 true JPH0615858B2 (en) 1994-03-02

Family

ID=15261194

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59140112A Expired - Lifetime JPH0615858B2 (en) 1984-07-05 1984-07-05 Exhaust gas recirculation control system for engines with fuel injection system

Country Status (1)

Country Link
JP (1) JPH0615858B2 (en)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3011580A1 (en) * 1980-03-26 1981-10-01 Robert Bosch Gmbh, 7000 Stuttgart DEVICE FOR THE OPERATING MIXTURE SUPPLY OF INTERNAL COMBUSTION ENGINES
JPS57120756U (en) * 1981-01-20 1982-07-27

Also Published As

Publication number Publication date
JPS6119961A (en) 1986-01-28

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