JPS63140839A - Electronic control fuel injection device for internal combustion engine - Google Patents
Electronic control fuel injection device for internal combustion engineInfo
- Publication number
- JPS63140839A JPS63140839A JP28601886A JP28601886A JPS63140839A JP S63140839 A JPS63140839 A JP S63140839A JP 28601886 A JP28601886 A JP 28601886A JP 28601886 A JP28601886 A JP 28601886A JP S63140839 A JPS63140839 A JP S63140839A
- Authority
- JP
- Japan
- Prior art keywords
- fuel ratio
- air
- fuel injection
- fuel
- correction coefficient
- 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 154
- 238000002347 injection Methods 0.000 title claims abstract description 43
- 239000007924 injection Substances 0.000 title claims abstract description 43
- 238000002485 combustion reaction Methods 0.000 title claims description 6
- 238000001514 detection method Methods 0.000 claims abstract description 11
- 230000008859 change Effects 0.000 claims description 23
- 230000004043 responsiveness Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 20
- 230000008569 process Effects 0.000 description 20
- 230000001133 acceleration Effects 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000013459 approach Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Description
【発明の詳細な説明】 〈産業上の利用分野〉 本発明は内燃機関の電子制御燃料噴射装置に関する。[Detailed description of the invention] <Industrial application field> The present invention relates to an electronically controlled fuel injection system for an internal combustion engine.
〈従来の技術〉
内燃機関の電子制御燃料噴射装置の従来例として以下の
ようなもあがある（実願昭６０−０６６５５８号）。<Prior Art> There is also the following conventional example of an electronically controlled fuel injection device for an internal combustion engine (Utility Application No. 60-066558).
すなわち、エアフローメータ等により検出された吸入空
気流量Ｑと機関回転速度Ｎとから基本噴耐量Ｔｐ−Ｋｘ
Ｑ／Ｎ （Ｋは定数）を演算すると共に、主として水温
に応じた各種補正係数Ｃ０ＥＦと実際の空燃比が理論空
燃比になるように設定された空燃比フィードバック補正
係数αとバフテリ電圧による補正係数Ｔｓとを演算した
後、定常運転時における燃料噴射量Ｔ ｉ ＝ Ｔ ｐ
Ｘ ＣＯＥ Ｆ×α＋Ｔｓを演算する。That is, the basic injection tolerance Tp-Kx is determined from the intake air flow rate Q detected by an air flow meter etc. and the engine rotational speed N.
In addition to calculating Q/N (K is a constant), various correction coefficients C0EF mainly depending on the water temperature, an air-fuel ratio feedback correction coefficient α set so that the actual air-fuel ratio becomes the stoichiometric air-fuel ratio, and a correction coefficient based on the buff battery voltage are calculated. After calculating Ts, the fuel injection amount during steady operation T i = T p
Calculate X COE F×α+Ts.
そして、例えばシングルポイントインジェクシ町ンシス
テム（以下ＳＰ１方式）では、機関の２回転毎に点火信
号等に同期して燃料噴射弁に対し前記燃料噴射量Ｔｔに
対応するパルス巾の噴射パルス信号を出力し機関に燃料
を供給する。For example, in a single point injection system (hereinafter referred to as SP1 system), an injection pulse signal with a pulse width corresponding to the fuel injection amount Tt is sent to the fuel injection valve in synchronization with an ignition signal etc. every two revolutions of the engine. output and supply fuel to the engine.
ところで、近年燃費の向上や排気の浄化等を目的として
、機関の低速低負荷運転域において、実際の空燃比が理
論空燃比よりも薄くなるように空燃比制御するようにし
たものがある。Incidentally, in recent years, for the purpose of improving fuel efficiency and purifying exhaust gas, some engines have been designed to control the air-fuel ratio so that the actual air-fuel ratio becomes thinner than the stoichiometric air-fuel ratio in the low-speed, low-load operating range of the engine.
即ち、高出力を必要とせず希薄燃焼させても良い所定の
低速定負荷運転領域であることが判定されると、実際の
空燃比が略理論空燃比となるように設定される燃料噴射
ｉｔ（以下、理論空燃比制御と呼ぶ）を、目標空燃比を
切り換えて実際の空燃比が所定の希薄空燃比となるよう
に減量設定して燃料噴射制御（以下、希薄空燃比制御と
呼ぶ）するものであり、これにより燃料消費量を少なく
すると共に、排気中の有害成分を低減しようとするもの
である。In other words, when it is determined that the operation is in a predetermined low-speed constant-load operation region that does not require high output and may allow lean combustion, the fuel injection it ( A system that controls fuel injection by switching the target air-fuel ratio (hereinafter referred to as stoichiometric air-fuel ratio control) and setting a reduction so that the actual air-fuel ratio becomes a predetermined lean air-fuel ratio (hereinafter referred to as lean air-fuel ratio control). This aims to reduce fuel consumption and reduce harmful components in exhaust gas.
〈発明が解決しようとする問題点〉
しかしながら、このような従来の電子制御燃料噴射装置
においては、定常運転状態で理論空燃比制御から希薄空
燃比制御に急激に切り換えると、急激に機関出力が低下
して運転フィーリングが悪化するという不具合がある。<Problems to be Solved by the Invention> However, in such conventional electronically controlled fuel injection systems, when switching suddenly from stoichiometric air-fuel ratio control to lean air-fuel ratio control during steady operation, the engine output suddenly decreases. The problem is that the driving feeling deteriorates.
また、加速運転あるいは減速運転時から希薄空燃比運転
可能な運転領域である定常運転に移行した直後には急激
に希薄空燃比制御に切り換えないと、燃費或いはＮＯｘ
の低減化が図れないという不具合がある。又は大きな負
荷変動を伴う上記移行時はその時発生するトルク変動を
希薄空燃比制御に急激に切換えることにより抑制し運転
フィーリングの悪化を抑制できる。しかしフィードバッ
ク制御によりこれを行うと実際の空燃比を検出する酸素
センサの検出応答遅れによって実際の空燃比を急激に希
薄空燃比にすることができない。In addition, immediately after transitioning from acceleration or deceleration to steady operation, which is the operating range in which lean air-fuel ratio operation is possible, it is necessary to suddenly switch to lean air-fuel ratio control, which will reduce fuel consumption or NOx.
There is a problem in that it is not possible to reduce the Alternatively, at the time of the above-mentioned transition accompanied by large load fluctuations, the torque fluctuations occurring at that time can be suppressed by abruptly switching to lean air-fuel ratio control, thereby suppressing deterioration of driving feeling. However, if this is done using feedback control, the actual air-fuel ratio cannot be made to be a lean air-fuel ratio rapidly due to a delay in the detection response of the oxygen sensor that detects the actual air-fuel ratio.
本発明は、このような実状に鑑みてなされたもので、希
薄空燃比制御を行っても加速運転直後の燃費及びＮＯｘ
の低減化を図りつつ運転フィーリングを向上できる電子
側ｍ燃料噴射装置を提供することを目的とする。The present invention has been made in view of the above-mentioned circumstances, and even if lean air-fuel ratio control is performed, the fuel consumption and NOx levels immediately after acceleration are reduced.
An object of the present invention is to provide an electronic side m-fuel injection device that can improve the driving feeling while reducing the amount of noise.
〈問題点を解決するための手段〉
このため、本発明第１図に示すように機関の実際の空燃
比を検出する空燃比検出手段Ａと、機関の負荷を検出す
る負荷検出手段Ｂと、検出された負荷に基づいて負荷変
化率を演算する負荷変化率演算手段Ｃと、演算された負
荷変化率が所定値以上か否かを判定する負荷変化率判定
手段りと、理論空燃比より希薄な略一定の希薄空燃比と
なるようにフィードフォワード補正係数を設定するフィ
ードフォワード補正係数設定手段Ｅと、検出された実際
の空燃比に基づいて実際の空燃比が目標希薄空燃比にな
るようにフィードバック補正係数を設定するフィードバ
ック補正係数設定手段Ｆと、負荷変化率が所定値以上と
判定されたときに希薄空燃比制御初期のを選択しその後
フィードバック補正係数を選択しその後フィードバック
補正係数を選択する第１選択手段Ｇと、負荷変化率が所
定値未満と判定されたときに希薄空燃比制御開始時から
前記フィードバック補正係数を選択する第２選択手段Ｈ
と、第１若しくは第２選択手段Ｇ、Ｈにより選択された
補正係数に基づいて燃料噴射量を設定する燃料噴射量設
定手段■と、設定された燃料噴射量に応じて燃料噴射弁
Ｊを駆動する駆動手段にと、を備えるようにした。<Means for solving the problem> For this reason, as shown in FIG. 1 of the present invention, air-fuel ratio detection means A for detecting the actual air-fuel ratio of the engine, load detection means B for detecting the load of the engine, Load change rate calculation means C calculates a load change rate based on the detected load; load change rate determination means C determines whether the calculated load change rate is equal to or greater than a predetermined value; a feedforward correction coefficient setting means E for setting a feedforward correction coefficient so that the lean air-fuel ratio becomes a substantially constant lean air-fuel ratio; Feedback correction coefficient setting means F for setting a feedback correction coefficient, and when it is determined that the load change rate is equal to or higher than a predetermined value, selects an initial lean air-fuel ratio control, then selects a feedback correction coefficient, and then selects a feedback correction coefficient. a first selection means G; and a second selection means H for selecting the feedback correction coefficient from the start of lean air-fuel ratio control when the load change rate is determined to be less than a predetermined value.
, fuel injection amount setting means (2) for setting the fuel injection amount based on the correction coefficient selected by the first or second selection means G, H, and driving the fuel injection valve J according to the set fuel injection amount. The driving means for the purpose of the present invention includes and.
く作用）
このようにして、負荷変化率が所定値以上すなわち所定
値以上の加・減速運転から希薄空燃比制御に移行すると
きにその初期にフィードフォワード制御により実際の空
燃比を急激に希１空燃比にした後、フィードバック制御
により目標希薄空燃比に近づけるようにする。一方、負
荷変化率が所定値未満のときには希薄空燃比制御開始時
からフイードバック制御により実際の空燃比を目標空燃
比に近づけるようにする。In this way, when transitioning from acceleration/deceleration operation where the load change rate is above a predetermined value, that is, above the predetermined value, to lean air-fuel ratio control, the actual air-fuel ratio is rapidly reduced to lean air-fuel ratio by feedforward control at the initial stage. After setting the air-fuel ratio to the target lean air-fuel ratio, feedback control is performed to bring it closer to the target lean air-fuel ratio. On the other hand, when the load change rate is less than the predetermined value, the actual air-fuel ratio is brought closer to the target air-fuel ratio by feedback control from the start of the lean air-fuel ratio control.
〈実施例〉
以下に、本発明の一実施例を第２図〜第５図に基づいて
説明する。<Example> An example of the present invention will be described below based on FIGS. 2 to 5.
第２図において、例えばマイクロコンピュータからなる
制御装置１には、点火コイル２から出力される点火信号
（回転速度信号）、エアフローメータ３から出力される
吸入空気流量信号、水温センサ４から出力される冷却水
温度信号、車速センサ５から出力される車速信号、アイ
ドルスイッチ６からの０Ｎ−ＯＦＦ信号、空燃比検出手
段としての酸素センサ７ （排気中の酸素濃度によって
理論空燃比を含む広範囲の空燃比を検出できるセンサ）
からの空燃比検出信号、とが入力されている。In FIG. 2, a control device 1 consisting of a microcomputer, for example, receives an ignition signal (rotational speed signal) output from an ignition coil 2, an intake air flow rate signal output from an air flow meter 3, and a water temperature sensor 4. A cooling water temperature signal, a vehicle speed signal output from the vehicle speed sensor 5, an 0N-OFF signal from the idle switch 6, an oxygen sensor 7 as an air-fuel ratio detection means (a wide range of air-fuel ratios including the stoichiometric air-fuel ratio depending on the oxygen concentration in the exhaust gas) (sensor that can detect)
The air-fuel ratio detection signal from
制御装置１は、第３図〜第５図に示すフローチャートに
従って作動し、燃料噴射弁８に駆動回路９を介して駆動
パルス信号を出力するようになっている。The control device 1 operates according to the flowcharts shown in FIGS. 3 to 5, and outputs a drive pulse signal to the fuel injection valve 8 via the drive circuit 9.
ここでは、制御装置１が負荷変化率演算手段と負荷変化
率判定手段とフィードフォワード補正係数設定手段とフ
ィードバック補正係数設定手段と第１及び第２選択手段
と燃料噴射量設定手段とを構成する。また、制御装置１
と駆動回路９とにより、駆動手段が構成される。また、
機関１回転当りの吸入空気流量から演算される基本噴射
量の変化率を負荷変化率と使用するためエアフローメー
タ３が負荷検出手段を構成する。Here, the control device 1 constitutes a load change rate calculation means, a load change rate determination means, a feedforward correction coefficient setting means, a feedback correction coefficient setting means, first and second selection means, and a fuel injection amount setting means. In addition, the control device 1
and the drive circuit 9 constitute a drive means. Also,
Since the rate of change in the basic injection amount calculated from the flow rate of intake air per engine revolution is used as the rate of change in load, the air flow meter 3 constitutes a load detection means.
次に作用を第３図〜第５図のフローチャートに従って説
明する。Next, the operation will be explained according to the flowcharts shown in FIGS. 3 to 5.
まず、燃料噴射量演算ルーチンを第３図に基づいて説明
すると、Ｓｌでは、点火信号、吸入空気流量信号等の各
種信号を読み込む。First, the fuel injection amount calculation routine will be explained based on FIG. 3. At Sl, various signals such as an ignition signal and an intake air flow rate signal are read.
Ｓ２では、点火信号から得られた機関回転速度Ｎと吸入
空気流量Ｑとから基本噴射量Ｔｐ （＝ＫＮ−には定数
）を演算する。In S2, a basic injection amount Tp (=KN- is a constant) is calculated from the engine rotational speed N obtained from the ignition signal and the intake air flow rate Q.
３３〜Ｓ７では、希薄空燃比制御条件を判定する。In 33 to S7, lean air-fuel ratio control conditions are determined.
すなわち、Ｓ３では、演算された基本噴射量Ｔｐが設定
値ＴｐｌからＴ ｐ ｔまでの範囲に入っている否かを
判定し、ＹＥＳのときには、Ｓ４に進みＮｏのときには
Ｓ２２に進む。That is, in S3, it is determined whether or not the calculated basic injection amount Tp is within the range from the set value Tpl to T p t. If YES, the process proceeds to S4, and if NO, the process proceeds to S22.
Ｓ４では、機関回転速度Ｎが設定値Ｎ１からＮ。In S4, the engine rotational speed N changes from the set value N1 to N.
までの範囲に入っているか否かを判定し、ＹＥＳのとき
にはＳ５に進み、ＮｏのときにはＳ２２に進む。It is determined whether or not it is within the range up to, and if YES, the process proceeds to S5, and if NO, the process proceeds to S22.
Ｓ５では、検出された冷却水温度Ｔｗが所定値（例えば
８０℃）以上か否かを判定し、ＹＥＳのときにはＳ６に
進み、ＮｏのときにはＳ２２に進む。In S5, it is determined whether or not the detected cooling water temperature Tw is equal to or higher than a predetermined value (for example, 80° C.). If YES, the process proceeds to S6; if NO, the process proceeds to S22.
Ｓ６では、アイドルスイッチ６がＯＮ（吸気絞弁全閉時
）かＯＦＦかを判定し、ＯＦＦのときには、Ｓ７に進み
ＯＮのときにはＳ２２に進む。In S6, it is determined whether the idle switch 6 is ON (when the intake throttle valve is fully closed) or OFF, and if it is OFF, the process proceeds to S7, and if it is ON, the process proceeds to S22.
Ｓ７では、検出された車速か所定値（例えば８ｋｍ／ｈ
）以上か否かを判定し、ＹＥＳのときには、Ｓ８に進み
Ｎｏのときには３２２に進む。In S7, the detected vehicle speed is set to a predetermined value (for example, 8 km/h).
) or more, and if YES, proceed to S8; if NO, proceed to 322.
このようにして希薄空燃比制御条件（第６図参照）と判
定されたときには、Ｓ８において前回と今回演算された
基本噴射ｔＴｐの差ΔＴｐを、演算する。When the lean air-fuel ratio control condition (see FIG. 6) is thus determined, the difference ΔTp between the basic injection tTp calculated last time and this time is calculated in S8.
Ｓ９では、演算された差の絶対値１ΔＴｐｌが所定値Δ
ＴｐＬを越えているか否かを判定し、ＹＥＳのときには
３１０に進みＮｏのときにはＳ１５に進む。In S9, the absolute value 1ΔTpl of the calculated difference is set to a predetermined value Δ
It is determined whether or not TpL has been exceeded. If YES, the process proceeds to 310; if No, the process proceeds to S15.
３１０では、タイマの°カウント値をリセットし新たに
カウントを開始させ、Ｓｌｌに進む。At 310, the timer's count value is reset to start a new count, and the process proceeds to Sll.
Ｓｌｌでは、タイマのカウント値が希薄空燃比制御条件
と判定された時から第１設定時間Ｔ１ （例えば１．、
ｃで第７図参照）を経過したか否かを判定し、ＹＥＳの
ときにはＳ１２に進みＮＯのときには、Ｓ２２に進む。In Sll, the first set time T1 (for example, 1.
At step c, it is determined whether or not the period (see FIG. 7) has elapsed, and if YES, the process advances to S12, and if NO, the process advances to S22.
５１２ではタイマのカウント値が希薄空燃比制御条件と
判定された時から、第２設定時間Ｔｔ（例えば１．２ｓ
ｅｃで第７図参照）を経過したか否かを判定し、ＹＥＳ
のときにはＳ１７に進みＮｏのときにはＳ１３に進む。At step 512, the second set time Tt (for example, 1.2 s
ec (see Figure 7) has elapsed, and select YES.
If so, the process advances to S17, and if No, the process advances to S13.
Ｓ１３では、三次元マツプからフィードフォワード補正
係数としてのリーンバーン補正係数ＬＢＣを機関回転速
度Ｎと基本噴射量Ｔｐとに基づいて検索する。In S13, a lean burn correction coefficient LBC as a feedforward correction coefficient is searched from the three-dimensional map based on the engine rotational speed N and the basic injection amount Tp.
ここで、前記リーンバーン補正係数はロード走行時に空
燃比が最も希薄化され負荷の増大に伴って空燃比が理論
空燃比に近づくように三次元マツプに記憶されている。Here, the lean burn correction coefficient is stored in a three-dimensional map so that the air-fuel ratio becomes the leanest during road running, and as the load increases, the air-fuel ratio approaches the stoichiometric air-fuel ratio.
一方、３１５では、タイマのカウント値に＋１を加算し
て新たなカウント値を得て、Ｓ１６に進む。On the other hand, in step 315, +1 is added to the count value of the timer to obtain a new count value, and the process proceeds to S16.
Ｓ１６では、タイマのカウント値が前記第１設定時間Ｔ
１を経過したか否かを判定し、ＹＥＳのときにはＳ１７
に進み、ＮｏのときにはＳ２２に進む。In S16, the count value of the timer is equal to the first set time T.
1 has elapsed, and if YES, S17
If the answer is No, the process advances to S22.
Ｓ１７では、酸素センサ７の検出信号を読み込んで、３
１８では酸素センサ７の検出信号に基づいて空燃比マツ
プから実際の空燃比を検索してＳ１９に進む。In S17, the detection signal of the oxygen sensor 7 is read, and 3
At step 18, the actual air-fuel ratio is searched from the air-fuel ratio map based on the detection signal of the oxygen sensor 7, and the process proceeds to step S19.
Ｓ１９では、検索された空燃比すなわち実際の空燃比と
目標希薄空燃比とを比較し、実際の空燃比がリンチのと
きには３２０に進みリーンのときにはＳ２１に進む。In S19, the searched air-fuel ratio, that is, the actual air-fuel ratio, is compared with the target lean air-fuel ratio, and if the actual air-fuel ratio is lean, the process proceeds to 320, and if it is lean, the process proceeds to S21.
３２０では、前回設定されたフィードバック補正係数と
してのリーンバーン補正係数ＬＢＣから所定値ΔＬを減
算して実際の空燃比が目標希薄空燃比に近づくように新
たなリーンバーン補正係数ＬＢＣを設定する。尚、実際
の空燃比が口約希薄空燃比のときには前回のリーンバー
ン補正係数を使用する。At 320, a predetermined value ΔL is subtracted from the previously set lean burn correction coefficient LBC as the feedback correction coefficient to set a new lean burn correction coefficient LBC so that the actual air-fuel ratio approaches the target lean air-fuel ratio. Note that when the actual air-fuel ratio is approximately a lean air-fuel ratio, the previous lean burn correction coefficient is used.
一方、Ｓ２１では前回設定されたリーンバーン補正係数
ＬＢＣに所定値ΔＬを加算して、実際の空燃比が目標希
薄空燃比に近づくように新たなリーンバーン補正係数Ｌ
ＢＣを設定する。On the other hand, in S21, a predetermined value ΔL is added to the previously set lean burn correction coefficient LBC, and a new lean burn correction coefficient L is added so that the actual air-fuel ratio approaches the target lean air-fuel ratio.
Set BC.
そして、３１４では、Ｓ１３で検索されたリーンバーン
補正係数ＬＢＣまたはＳ２０若しくはＳ２１にて設定さ
れたリーンバーン補正係数ＬＢＣに基づいて燃料噴射量
Ｔｉを次式により演算する。Then, in 314, the fuel injection amount Ti is calculated based on the lean burn correction coefficient LBC retrieved in S13 or the lean burn correction coefficient LBC set in S20 or S21 using the following equation.
Ｔｉ＝ＴｐＸＬＢＣＸＣＯＥＦＸＫＢＬＲＣ＋ＣＯＥＦ
は水温等を含む各種補正係数、Ｔｓはバフテリ電圧によ
る補正係数、ＫＢＬＲＣは理論空燃比制御時に燃料噴射
弁８の経時変化率を補正する学習係数である。Ti=TpXLBCXCOEFXKBLRC+COEF
are various correction coefficients including water temperature, etc., Ts is a correction coefficient based on buffer voltage, and KBLRC is a learning coefficient that corrects the rate of change over time of the fuel injection valve 8 during stoichiometric air-fuel ratio control.
一方、希薄空燃比制御条件と判定されず或いは判定され
ても第１設定時間Ｔ、の間はＳ２２において実際の空燃
比が略理論空燃比になるように燃料噴射ＮＴｉを次式に
より演算する。On the other hand, during the first set time T, even if the lean air-fuel ratio control condition is not determined or determined, the fuel injection NTi is calculated by the following equation in S22 so that the actual air-fuel ratio becomes approximately the stoichiometric air-fuel ratio.
Ｔｉ−ＴｐＸαＸＣ０ＥＦＸＫＢＬＲＣ＋Ｔｓαは従来
例と同様に実際の空燃比が理論空燃比になるように設定
された空燃比フィードバック補正係数である。Ti-TpXαXC0EFXKBLRC+Tsα is an air-fuel ratio feedback correction coefficient set so that the actual air-fuel ratio becomes the stoichiometric air-fuel ratio, as in the conventional example.
このようにして、Ｓ１４若しくはＳ２２にて演算された
燃料噴射量Ｔｉは第４図に示すフローチャートに従って
例えば点火コイル２からのリファレンス信号（回転数）
に同期して駆動回路９を介して燃料噴射弁８に出力し燃
料噴射を行う。In this way, the fuel injection amount Ti calculated in S14 or S22 is determined by the reference signal (rotational speed) from the ignition coil 2, for example, according to the flowchart shown in FIG.
In synchronization with this, the signal is output to the fuel injection valve 8 via the drive circuit 9 to perform fuel injection.
また、前記目標希薄空燃比は第５図のフローチャートに
従って設定される。すなわち、Ｓ４１では、空燃比マツ
プから機関回転速度Ｎと基本噴射量Ｔｐとに基づいて目
標希薄空燃比を検索し、Ｓ４２では検索された目標希薄
空燃比をＲＡＭ等に記憶させ、その値を第３図のフロー
チャートにおいて使用する。Further, the target lean air-fuel ratio is set according to the flowchart shown in FIG. That is, in S41, a target lean air-fuel ratio is searched from the air-fuel ratio map based on the engine rotational speed N and the basic injection amount Tp, and in S42, the searched target lean air-fuel ratio is stored in a RAM or the like, and the value is stored in the RAM or the like. It is used in the flowchart in Figure 3.
このようにすると、希薄空燃比制御条件と判定された時
から第１設定時間ＴＩを経過するまでは差の絶対値１Δ
Ｔｐｌの大小に拘わらず判定直前と同様に実際の空燃比
が例えば理論空燃比になるようにフィードバック制御さ
れる。これにより、第６図に示すように希薄空燃比制御
領域外のＡ点からＢ点までの加速運転時に、希薄空燃比
制御領域を一時的に通過し希薄空燃比制御条件が判定さ
れても前記第１設定時間Ｔ、の間、希薄空燃比制御がな
されないため、実際の空燃比の希薄化を防止でき加速性
能を良好に維持できる。In this way, the absolute value of the difference is 1Δ from the time when it is determined that the lean air-fuel ratio control condition is reached until the first set time TI has elapsed.
Regardless of the magnitude of Tpl, feedback control is performed so that the actual air-fuel ratio becomes, for example, the stoichiometric air-fuel ratio in the same way as immediately before the determination. As a result, as shown in FIG. 6, during acceleration operation from point A to point B outside the lean air-fuel ratio control region, even if the lean air-fuel ratio control region is temporarily passed and the lean air-fuel ratio control condition is determined. Since the lean air-fuel ratio control is not performed during the first set time T, it is possible to prevent the actual air-fuel ratio from becoming leaner and maintain good acceleration performance.
また、第１設定時間Ｔ、経過後においては前記差の絶対
値１ΔＴｐｌが所定値ΔＴｐＬを超えているときには第
２設定時間Ｔ２が経過するまでは、三次元マツプにより
検索されたリーンバーン補正係数ＬＢＣに基づいて燃料
噴射量Ｔｉが演算されるため、第７図に示すように、第
１設定時間Ｔ１経過後第２設定時間Ｔ２経過するまでは
実際の空燃比が理論空燃比より希薄化された一定の希薄
空燃比に維持される。これにより、加速運転直後に希薄
空燃比制御がなされるときには、第１設定時間ＴＩ経過
後に実際の空燃比が理論空燃比から希薄空燃比に急激に
低下するので、希薄空燃比制御への移行時に排気中のＮ
Ｏｘ排出量を低減しつつ希薄空燃比制御により燃費の向
上を図ることができる。Furthermore, if the absolute value 1ΔTpl of the difference exceeds the predetermined value ΔTpL after the first set time T has elapsed, the lean burn correction coefficient LBC searched by the three-dimensional map is Since the fuel injection amount Ti is calculated based on A constant lean air/fuel ratio is maintained. As a result, when lean air-fuel ratio control is performed immediately after acceleration driving, the actual air-fuel ratio rapidly decreases from the stoichiometric air-fuel ratio to the lean air-fuel ratio after the first set time TI has elapsed, so when transitioning to lean air-fuel ratio control, N in exhaust
Fuel efficiency can be improved by lean air-fuel ratio control while reducing Ox emissions.
一方、差の絶対値１ΔＴｐｌが所定値以下すなわち超緩
加速運転成いは定常運転から希薄空燃比制御に移行する
ときには、前記第１設定時間Ｔ１経過後に酸素センサ７
により検出された実際の空燃比が目標希薄空燃比になる
ようにフィードバック制御するようにしたので、第７図
中破線で示すように、フィードバック制御初期に実際の
空燃比は、目標希薄空燃比に経時と共に徐々に近づいた
後、目標希薄空燃比付近においてフィードバック制御さ
れる。これにより、希薄空燃比制御への移行時に機関出
力が経時と共に徐々に低下するので、運転フィーリング
の悪化を抑制できる。On the other hand, when the absolute value 1ΔTpl of the difference is less than the predetermined value, that is, when transitioning from ultra-slow acceleration operation or steady operation to lean air-fuel ratio control, the oxygen sensor 7
Feedback control is performed so that the actual air-fuel ratio detected by is equal to the target lean air-fuel ratio, so as shown by the broken line in Figure 7, the actual air-fuel ratio does not reach the target lean air-fuel ratio at the beginning of the feedback control. After gradually approaching the target lean air-fuel ratio over time, feedback control is performed near the target lean air-fuel ratio. Thereby, since the engine output gradually decreases over time when shifting to lean air-fuel ratio control, it is possible to suppress deterioration of driving feeling.
尚、本実施例では、基本噴射量の単位時間当りの変化率
すなわち前回と今回との差の絶対値１ΔＴｐｌから希薄
空燃比制御開始直前の機関運転状態を判定するようにし
たが、吸入負圧、スロットル弁開度、トルク、スロット
ル弁の開口面積等の変化率から判定するようにしてもよ
い。In this embodiment, the engine operating state immediately before the start of lean air-fuel ratio control is determined from the rate of change of the basic injection amount per unit time, that is, the absolute value 1ΔTpl of the difference between the previous and current times. The determination may be made from the rate of change of the throttle valve opening, torque, opening area of the throttle valve, etc.
〈発明の効果〉
本発明は、以上説明したように、負荷変化率が所定値以
上のときに希薄空燃比制御をフィードフォワード制御に
より急激に希薄化空燃比に近づけた後フィードバック制
御により行う一方、負荷変化率が所定値未満のときにフ
ィードバック制御により希薄空燃比制御を行うようにし
たので、例えば加速運転直後からの希薄空燃比制御時に
はＮＯｘ排出量の低減化を図りつつ、燃費の向上を図れ
る一方、例えば定常運転時の希薄空燃比制御時には、空
燃比を徐々に希薄空燃比に近づけることにより機関出力
を徐々に低下させるため、運転フィーリングの向上を図
れる。<Effects of the Invention> As explained above, the present invention performs lean air-fuel ratio control by rapidly approaching the lean air-fuel ratio by feedforward control and then by feedback control when the load change rate is equal to or higher than a predetermined value. Since lean air-fuel ratio control is performed by feedback control when the load change rate is less than a predetermined value, for example, when controlling the lean air-fuel ratio immediately after acceleration, it is possible to reduce NOx emissions and improve fuel efficiency. On the other hand, for example, during lean air-fuel ratio control during steady operation, the engine output is gradually reduced by gradually bringing the air-fuel ratio closer to the lean air-fuel ratio, thereby improving the driving feeling.
第１図は本発明のクレーム対応図、第２図は本発明の一
実施例を示す構成図、第３図〜第５図は同上のフローチ
ャート、第６図及び第７図は同上の作用を説明するため
の図である。
１・・・制御装置 ２・・・点火コイル ３・・・
工゛アフロ−メータ ４・・・水温センサ ５・・
・車速センサ ６・・・アイドルスイッチ ７・・
・酸素センサ ８・・・燃料噴射弁 ９・・・駆動
回路特許出願人 日本電子機器株式会社代理人 弁
理士 笹 島 冨二雄
第３図その２
第４図
第５図
機関回転ＶＬ度
第７図Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a configuration diagram showing an embodiment of the present invention, Figs. 3 to 5 are flowcharts of the same, and Figs. It is a figure for explaining. 1... Control device 2... Ignition coil 3...
Work flow meter 4...Water temperature sensor 5...
・Vehicle speed sensor 6...Idle switch 7...
・Oxygen sensor 8... Fuel injection valve 9... Drive circuit patent applicant Japan Electronics Co., Ltd. agent Patent attorney Fujio Sasashima Figure 3, Part 2 Figure 4 Figure 5 Engine rotation VL degree No. 7 figure
Claims (1)
たときに実際の空燃比が理論空燃比より希薄化されるよ
うに希薄空燃比制御を行う内燃機関の電子制御燃料噴射
装置において、機関の実際の空燃比を検出する空燃比検
出手段と、機関の負荷を検出する負荷検出手段と、検出
された負荷に基づいて負荷変化率を演算する負荷変化率
演算手段と、演算さた負荷変化率が所定値以上か否かを
判定する負荷変化率判定手段と、理論空燃比より希薄な
略一定の希薄空燃比となるようにフィードフォワード補
正係数を設定するフィードフォワード補正係数設定手段
と、検出された実際の空燃比に基づいて実際の空燃比が
目標希薄空燃比になるようにフィードバック補正係数を
設定するフィードバック補正係数設定手段と、負荷変化
率が所定値以上と判定されたときに希薄空燃比制御初期
のを選択しその後フィードバック補正係数を選択する第
１選択手段と、負荷変化率が所定値未満と判定されたと
きに希薄空燃比制御開始時から前記フィードバック補正
係数を選択する第２選択手段と、第１若しくは第２選択
手段により選択された補正係数に基づいて燃料噴射量を
設定する燃料噴射量設定手段と、設定された燃料噴射量
に応じて燃料噴射弁を駆動する駆動手段と、を備えたこ
とを特徴とする内燃機関の電子制御燃料噴射装置。In an electronically controlled fuel injection system for an internal combustion engine that performs lean air-fuel ratio control such that when a predetermined lean air-fuel ratio control condition is detected in a predetermined operating region, the actual air-fuel ratio is leaner than the stoichiometric air-fuel ratio. air-fuel ratio detection means for detecting the actual air-fuel ratio of the engine; load detection means for detecting the engine load; load change rate calculation means for calculating the load change rate based on the detected load; and load change rate calculation means for calculating the load change rate based on the detected load. load change rate determining means for determining whether or not the ratio is equal to or higher than a predetermined value; a feedback correction coefficient setting means for setting a feedback correction coefficient so that the actual air-fuel ratio becomes the target lean air-fuel ratio based on the actual air-fuel ratio that has been determined; a first selection means for selecting an initial stage of the fuel ratio control and then selecting a feedback correction coefficient; and a second selection means for selecting the feedback correction coefficient from the start of the lean air-fuel ratio control when the load change rate is determined to be less than a predetermined value. means, a fuel injection amount setting means for setting the fuel injection amount based on the correction coefficient selected by the first or second selection means, and a driving means for driving the fuel injection valve according to the set fuel injection amount. An electronically controlled fuel injection device for an internal combustion engine, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28601886A JPS63140839A (en) | 1986-12-02 | 1986-12-02 | Electronic control fuel injection device for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28601886A JPS63140839A (en) | 1986-12-02 | 1986-12-02 | Electronic control fuel injection device for internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63140839A true JPS63140839A (en) | 1988-06-13 |
Family
ID=17698915
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28601886A Pending JPS63140839A (en) | 1986-12-02 | 1986-12-02 | Electronic control fuel injection device for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63140839A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995017592A1 (en) * | 1993-12-21 | 1995-06-29 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Combustion state judgement method of internal combustion engine, and method and apparatus for controlling combustion state of internal combustion engine |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5813131A (en) * | 1981-07-15 | 1983-01-25 | Nippon Denso Co Ltd | Air-fuel ratio control method |
| JPS58124040A (en) * | 1982-01-20 | 1983-07-23 | Toyota Motor Corp | Air-fuel ratio control method for internal-combustion engine |
| JPS60212653A (en) * | 1984-04-06 | 1985-10-24 | Nissan Motor Co Ltd | Fuel supply controlling apparatus for engine |
-
1986
- 1986-12-02 JP JP28601886A patent/JPS63140839A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5813131A (en) * | 1981-07-15 | 1983-01-25 | Nippon Denso Co Ltd | Air-fuel ratio control method |
| JPS58124040A (en) * | 1982-01-20 | 1983-07-23 | Toyota Motor Corp | Air-fuel ratio control method for internal-combustion engine |
| JPS60212653A (en) * | 1984-04-06 | 1985-10-24 | Nissan Motor Co Ltd | Fuel supply controlling apparatus for engine |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995017592A1 (en) * | 1993-12-21 | 1995-06-29 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Combustion state judgement method of internal combustion engine, and method and apparatus for controlling combustion state of internal combustion engine |
| US5687692A (en) * | 1993-12-21 | 1997-11-18 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Combustion state determination method of internal combustion engine, as well as combustion state control method and combustion state control system for internal combustion engine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH03271544A (en) | Control device of internal combustion engine | |
| JPS62162746A (en) | Air-fuel ratio control device | |
| JPH08189396A (en) | Air fuel ratio feedback control device for internal combustion engine | |
| JPS60240840A (en) | Control device of air-fuel ratio in internal-combustion engine | |
| JPS59539A (en) | Air-fuel ratio control of air-fuel mixture for internal- combustion engine of vehicle | |
| JP3791032B2 (en) | Fuel injection control device for internal combustion engine | |
| JPH0224550A (en) | Controlling device of heater power of oxygen concentration sensor with heater | |
| JPH04124439A (en) | Air fuel ratio control method for internal combustion engine | |
| JP2947065B2 (en) | Lean burn control device for internal combustion engine | |
| JPH051368B2 (en) | ||
| JPS63140839A (en) | Electronic control fuel injection device for internal combustion engine | |
| JP2521039B2 (en) | Engine air-fuel ratio control device | |
| JPH0419377B2 (en) | ||
| JPH08177576A (en) | Air-fuel ratio control device for engine | |
| JP2870286B2 (en) | Air-fuel ratio control device for lean burn engine | |
| JP3528193B2 (en) | Air-fuel ratio control device for lean burn engine | |
| JPS63140840A (en) | Electronic control fuel injection device for internal combustion engine | |
| JP3397085B2 (en) | Engine combustion fluctuation control device | |
| JPS63140838A (en) | Electronic control fuel injection device for internal combustion engine | |
| JPH04311640A (en) | Air-fuel ratio control device for internal combustion engine | |
| JPH06264801A (en) | Fail-safe device for auxiliary air control device | |
| JPH0791298A (en) | Air-fuel ratio controller of internal combustion engine | |
| JPS62203947A (en) | Air-fuel ratio control device | |
| JPS62186039A (en) | Engine combustion control device | |
| JPS6394047A (en) | Deceleration fuel decrement controller for electronic control fuel injection internal combustion engine |