JPS61237848A - Control device for air-fuel ratio in internal-combustion engine - Google Patents

Abstract

PURPOSE:To ensure smooth acceleration performance of an engine and its drivability, by constituting the engine such that target air-fuel ratio is corrected on the basis of an acceleration and deceleration condition while an air-fuel ratio correction in the acceleration time is continued after the engine is placed in the acceleration condition till it is changed into the deceleration condition. CONSTITUTION:An engine is equipped with an intake quantity arithmetic means 103 which calculates an intake quantity of air per one suction stroke of the engine in accordance with each output signal of an intake air quantity detecting means 101, detecting an intake quantity of air to the internal-combustion engine, and a speed detecting means 102 detecting an engine speed. While the engine, being equipped with an air-fuel ratio arithmetic means 104 calculating target air-fuel ratio on the basis of an intake quantity of air per one suction stroke and an engine speed, corrects said target air-fuel ratio by an air-fuel ratio correcting means 106 in accordance with an acceleration and deceleration condition detected by an acceleration and deceleration detecting means 105. And the engine is constituted such that the air-fuel ratio correcting means 106 continues on the basis of an acceleration and deceleration detection result an air-fuel ratio correction in the acceleration time after the engine is placed in the acceleration condition till it is changed into the deceleration condition.

Description

【発明の詳細な説明】 （産業上の利用分野） この発明は内燃機関の空燃比制御装置に関し、詳しくは
その加速時の空燃比補正制御動作の改良に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an air-fuel ratio control device for an internal combustion engine, and more particularly to an improvement in air-fuel ratio correction control operation during acceleration.

（従来の技術） 内燃機関の空燃比もしくは供給燃料量を電子制御する装
置が各種実用に供されているが、二の種の装置では当該
空燃比を決定するｌ二あたって一般に機関吸入空気量と
回転数とを直接または間接的に検出し、その結果に基づ
いて目標とする空燃比また１よ当該空燃比を実現するた
めの供給燃料量を決定するようになっている。ただし、
前記目標空燃比は機関が定常的な運転状態にあるときの
基本値であり、実際にはｎｒｙＪが暖機過程にあるかが
否かなどの運転状態によって各種の補正カン族されるこ
とになる。この各・槽中燃比補正のうち最も重要なもの
が加速時の補正であり、この補正の適否が機関の運転性
能を大きく左右する。(Prior Art) Various devices have been put into practical use that electronically control the air-fuel ratio or the amount of fuel supplied to an internal combustion engine, but in the second type of devices, the air-fuel ratio is generally determined based on the engine intake air amount. and the rotational speed are detected directly or indirectly, and based on the results, the amount of fuel to be supplied to achieve the target air-fuel ratio or the air-fuel ratio of 1 is determined. however,
The target air-fuel ratio is a basic value when the engine is in a steady operating state, and in reality, various corrections will be made depending on the operating state, such as whether or not NRYJ is in the warm-up process. . The most important of these corrections to the fuel ratio in the tank is the correction during acceleration, and the suitability of this correction greatly influences the operating performance of the engine.

すなわち、空燃比制御の原理上は加速によって吸気量が
増加すればこれにつれて燃料供給量も増えるのであるが
、実際には過渡的に生じる吸気量検出誤差や吸気Ｗ壁に
付着してすぐには機関シリングに到達しない燃料の分を
補正する必要が生じるのであり、これを適切に行わない
と息つきや加速性不良等の不具合が生じる。このため、
経済運転域からの加速時にトルクを増強する意味で出力
空燃比に補正する場合に限らず、例えば三元触媒の転化
効率を良好に維持するために基本的に理論空燃比に制御
することを前提としている制御装置にあっても加速補正
が必要になってくる。In other words, according to the principle of air-fuel ratio control, if the intake air amount increases due to acceleration, the fuel supply amount will also increase, but in reality, there may be transient intake air amount detection errors, or there may be problems such as adhesion to the intake W wall. It is necessary to compensate for the amount of fuel that does not reach the engine shilling, and if this is not done properly, problems such as shortness of breath and poor acceleration will occur. For this reason,
This is not limited to correcting the output air-fuel ratio in the sense of increasing torque when accelerating from the economical driving range, but it is basically assumed that the air-fuel ratio is controlled to the stoichiometric air-fuel ratio in order to maintain good conversion efficiency of a three-way catalyst, for example. Acceleration correction is required even in a control device that supports this.

（発明が解決しようとする問題点）　゛ところで、こう
した加速補正にあたっては、機関が当該補正を実行すべ
き加速状態にあるか否かを検出もしくは判断する必要が
あるが、これを従来は、例えば特開昭５９−１６２３３
４号公報に見られるように、スロットルバルブ開度や吸
気管圧力の微分値と予め定めた基準値との比較に基づい
て竹うようにしていたので、必ずしも実情に適した空燃
比には制御されないという開運があった。(Problem to be Solved by the Invention) ゛By the way, in performing such acceleration correction, it is necessary to detect or judge whether or not the engine is in an acceleration state in which the correction should be executed. Japanese Patent Publication No. 59-16233
As seen in Publication No. 4, the air-fuel ratio is not necessarily controlled to suit the actual situation because it is based on a comparison between the differential value of the throttle valve opening and intake pipe pressure and a predetermined reference value. I was lucky that it wasn't.

すなわち、前記スロットルバルブ開度による加速判定に
例を採ると、この場合運転者の加速要求によってスロッ
トルバルブ開度が増加しつつある過程で当該開度の変化
率が基準値を越えている限りにおいてのみ加速状態であ
ると判定されることになるので、余裕出力を見込んでア
クセルペダルの踏み込み等を終了させると運転者として
は加速を続ける意思があるにもかか、わらず空燃比制御
系では加速要求が終了したものとして加速補正を解除し
てしまい、この結果空燃比不適となって爾後の加速性が
悪化するという不具合を生じるのである。In other words, taking the acceleration determination based on the throttle valve opening as an example, in this case, as long as the rate of change in the throttle valve opening exceeds the reference value while the throttle valve opening is increasing due to the driver's acceleration request, Therefore, even if the driver intends to continue accelerating, if the driver stops depressing the accelerator pedal, etc. in anticipation of sufficient output, the air-fuel ratio control system The acceleration correction is canceled with the assumption that the acceleration request has ended, resulting in an inappropriate air-fuel ratio, resulting in a problem that subsequent acceleration performance deteriorates.

この不具合は定常的運転状態において希薄空燃比に制御
するようにした機関ではより顕著にあられれ、つまり通
常は希薄空燃比であっても加速時には良好な加速性能を
確保するために理論空燃比程度にまで空燃比を濃化補正
するので、前述したようにして加速過程で補正が終了す
ると８激にトルクの低下が起こり、このため運転者とし
ては所望の速度に達するまで再びアクセルペダルを踏み
込まなければならないといった事態を生じる。This problem is more noticeable in engines that control the air-fuel ratio to a lean air-fuel ratio under steady-state operating conditions.In other words, even if the air-fuel ratio is lean, the air-fuel ratio is usually kept at about the stoichiometric air-fuel ratio to ensure good acceleration performance during acceleration. Since the air-fuel ratio is enriched and corrected, as mentioned above, when the correction is finished during the acceleration process, the torque will drop dramatically, and the driver will have to depress the accelerator pedal again until the desired speed is reached. This may lead to situations where this is not possible.

この発明はこのような従来の問題点に着目してなされた
もので、運転者の加速要求が終了するまで確実に加速補
正状態を維持することを目的とする。The present invention has been made in view of these conventional problems, and it is an object of the present invention to reliably maintain an acceleration correction state until the driver's acceleration request is terminated.

（問題点を解決するための手段） 上記目的を達成するためにこの発明では、第１図に示し
たように、内燃機関の吸入空気量を検出する吸気量検出
手段１０１と、同じく回転数を検出する回転数検出手ｙ
、１０２と、前記吸気量と回転数とに基づいて機関の１
吸入行程あたりの吸入空気量を演算する吸気量演算手段
１０３と、この演算吸気量と回転数とに基づいて目標空
燃比を演算する空燃比演算手段１０４と、機関の加速状
態及び減速状態を検出する加減速検出手段１０５と、前
記加減速状態に基づいて前記目標空燃比を補正する空燃
比補正手段１０６とを有する空燃比制御装置を構成し、
かつ前記空燃比補正手段１０６は加減速検出結果に基づ
き機関が加速状態に入ったのち減速状態に転じるまで加
速時の空燃比補正を継続するように構成した。(Means for Solving the Problems) In order to achieve the above object, in this invention, as shown in FIG. Rotation speed detecting hand y
, 102 of the engine based on the intake air amount and rotation speed.
An intake air amount calculation means 103 that calculates the amount of intake air per intake stroke, an air-fuel ratio calculation means 104 that calculates a target air-fuel ratio based on the calculated intake air amount and rotation speed, and detects the acceleration state and deceleration state of the engine. an air-fuel ratio control device comprising an acceleration/deceleration detection means 105 for detecting acceleration/deceleration, and an air-fuel ratio correction means 106 for correcting the target air-fuel ratio based on the acceleration/deceleration state;
Furthermore, the air-fuel ratio correcting means 106 is configured to continue correcting the air-fuel ratio during acceleration based on the acceleration/deceleration detection result after the engine enters the acceleration state until the engine changes to the deceleration state.

（作用） 上記構成によれば、例えば加減速検出手段１０５として
吸気絞り弁開度を検出して当該開度の変化率と基準値と
を比較して加速または減速の判定を行うものを適用した
場合であっても、前記変化率と基準値との比較に基づい
て一度加速状態と判定されると開度変化率がゼロすなわ
ちスロ７）ルパルブ開度の増加が終了したのちも加速補
正状態が継続し、その状態からスロットルバルブ開度が
減少させられる状態つまり減速状態に入って初めて加速
補正が解除される。従って、運転者による　　゛加速要
求の意思が忠実に空燃比ないし供給燃料量に反映される
。(Function) According to the above configuration, for example, the acceleration/deceleration detecting means 105 is one that detects the opening of the intake throttle valve and compares the rate of change in the opening with a reference value to determine acceleration or deceleration. Even if the rate of change in the opening is determined to be in the acceleration state based on the comparison between the rate of change and the reference value, the rate of change in the opening will be zero, i.e., the acceleration correction state will continue even after the increase in the opening of the luparve is completed. The acceleration correction is canceled only when the throttle valve opening degree continues to be reduced and the throttle valve opening degree is reduced, that is, the deceleration state is entered. Therefore, the driver's intention to request acceleration is faithfully reflected in the air-fuel ratio or the amount of fuel supplied.

なお、上記構成のうち、吸気量演算手段１０３、空燃比
演算手段１０４、空燃比補正手段１０６は以下の実施例
に示すようにマイクロコンピュータに代表される単一の
制御装置として統合化することができる。Note that among the above configurations, the intake air amount calculation means 103, the air-fuel ratio calculation means 104, and the air-fuel ratio correction means 106 can be integrated as a single control device represented by a microcomputer, as shown in the following embodiment. can.

（実施例） 第２図に、この考案を電子制御燃料噴射装置付きの車両
用内ｍ機関に適用した実施例の機械的構成の概略を示す
。これを説明すると、１は内燃機関、２はエアクリーナ
、３は吸気量検出手段としてのエア７０−メータ、４は
吸気絞り弁７が介装されたスロットルチャンバ、５はイ
ンテークマニホールド、６は内燃機関１の吸入ボートに
臨むように設けられた電磁燃料噴射弁である。前記電磁
燃料噴射弁６は図示しない燃料系統を介して吸気管圧力
との間の相対圧が一定となるように加圧された燃料の供
給を受け、制御装置２０から送信されてくるパルス信号
のデユーティ比（オンオフ時間比）に応じた量の燃料を
噴射するようになっている。(Embodiment) FIG. 2 schematically shows the mechanical configuration of an embodiment in which this invention is applied to a vehicle internal combustion engine equipped with an electronically controlled fuel injection device. To explain this, 1 is an internal combustion engine, 2 is an air cleaner, 3 is an air 70-meter as an intake air amount detection means, 4 is a throttle chamber in which an intake throttle valve 7 is installed, 5 is an intake manifold, and 6 is an internal combustion engine. This is an electromagnetic fuel injection valve installed so as to face the first intake boat. The electromagnetic fuel injection valve 6 receives pressurized fuel via a fuel system (not shown) so that the relative pressure with the intake pipe pressure is constant, and receives a pulse signal transmitted from the control device 20. The amount of fuel is injected according to the duty ratio (on/off time ratio).

制御装置２０は主に中央処理装置２１、記憶装置２２、
入出力処理装置２３からなるマイクロコンピュータであ
り、前記入出力処理装置２３にはエア７０−メータ３か
らの吸気量信号の他に回転数検出手段にあたるクランク
角センサ２４からのクランクパルス信号が入力される０
機関回転数は前記クランク角センサ２４からの単位時間
あたりの出力パルス数を計数することにより算出され、
これと吸気量信号とから基本的な燃料噴射量が決定され
ることになる。入出力処理装置２３には、さらに絞り弁
７の位置もしくは開度を検出するスロットルボジシａン
センサ２７と、変速機のギヤ位置を検出するギヤポジシ
ョンセンサ２８からの信号が入力される。前記数り弁位
置信号は通常の燃料噴射量制御におけるアイドル運転状
態ないし高出力運転状態の判定に関与するほか、この発
明の特徴とする加速状態の判定及び加速時の燃料噴射量
補正のために利用される。The control device 20 mainly includes a central processing unit 21, a storage device 22,
It is a microcomputer consisting of an input/output processing device 23, and in addition to the intake air amount signal from the air 70-meter 3, a crank pulse signal from a crank angle sensor 24 serving as rotation speed detection means is inputted to the input/output processing device 23. Ru0
The engine rotation speed is calculated by counting the number of output pulses per unit time from the crank angle sensor 24,
The basic fuel injection amount is determined from this and the intake air amount signal. The input/output processing device 23 further receives signals from a throttle position sensor 27 that detects the position or opening of the throttle valve 7 and a gear position sensor 28 that detects the gear position of the transmission. The above-mentioned numerical valve position signal is involved in the determination of the idle operating state or high output operating state in normal fuel injection amount control, and is also used for determining the acceleration state and correcting the fuel injection amount during acceleration, which is a feature of the present invention. used.

次に、上記構成下での具体的な燃料噴射量制御の詳細を
第３図Ａ％Ｂに示した流れ図に沿って説明する。Next, details of specific fuel injection amount control under the above configuration will be explained along the flowchart shown in FIG. 3A%B.

まず制御の概要を説明すると、この制御では定常的運転
状態での空燃比（以下、空燃比をＦＡ／ＦＪと表すこと
がある）を高負荷時を除！最大２２〜２３程度に設定し
て希薄混合気運転を行い、加速時ＩＣはＡ／Ｆ＝１５程
度の理論空燃比を目標とするとともに加速開始直前のＡ
／Ｆに応じて前記目標値に向かって段階的にＡ／Ｆを補
正するという処理を行う。また、この場合変速機のギヤ
位置が加速に当たって出力増強の必要性に乏しい低速段
（例えば手動変速機では１ｓｔ〜２ｎｄギヤ）に在ると
きは加速時の空燃比補正を行わない。First, to explain the outline of the control, this control controls the air-fuel ratio (hereinafter, air-fuel ratio may be referred to as FA/FJ) under steady-state operating conditions, excluding times of high load. The maximum fuel mixture is set to about 22 to 23 to perform lean mixture operation, and during acceleration the IC aims for a stoichiometric air-fuel ratio of about A/F = 15, and the A/F ratio is set to about 15 at the time of acceleration.
A/F is corrected in stages toward the target value according to the A/F. Further, in this case, when the gear position of the transmission is in a low gear position (for example, 1st to 2nd gear in a manual transmission) where there is little need for output reinforcement during acceleration, air-fuel ratio correction during acceleration is not performed.

このような制御にあたって、制御装置２０ではまずクラ
ンク角センサ２４とエア７０−メータ３を介してｆ’ｌ
！関回転数Ｎと吸気？Ｘ量Ｑａを読み込み、次のような
計算式に基づく１吸入行程あたりの吸入空気量（これは
電磁燃料噴射弁６の基本噴射パルス幅に相当する）Ｔｐ
を演算する。For such control, the control device 20 first sends f'l via the crank angle sensor 24 and the air 70-meter 3.
! Seki rotation speed N and intake? Read the X amount Qa and calculate the intake air amount per one intake stroke (this corresponds to the basic injection pulse width of the electromagnetic fuel injection valve 6) Tp based on the following calculation formula.
Calculate.

Ｔｐ＝１０００　Ｋ／（ＮＸＱａ） ただし、Ｋは定数 なお、この場合エア７０−メータ３の出力は吸気流量が
増加するほど減少することを前提としており、従って上
の式に示したようにその出力値であるＱａにＮを乗じる
ことにより１行程あたりの吸入空気量に比例した値が得
られる。また、このＴｐの演算は算術的処理、または予
めＮとＱａとをパラメータとしてＴｐを与えるように記
憶装置２２のＲＯＭ部に形成されたマツプもしくはテー
ブルからの検索及び補間計算により行なわれる。Tp=1000 K/(NXQa) However, K is a constant.In this case, it is assumed that the output of air 70-meter 3 decreases as the intake flow rate increases, so the output By multiplying the value Qa by N, a value proportional to the amount of intake air per stroke can be obtained. The calculation of Tp is performed by arithmetic processing or by searching and interpolation calculation from a map or table formed in the ROM section of the storage device 22 so as to give Tp using N and Qa as parameters.

次に、このようにして求めたＴｐとＮとの関係から、上
記テーブルルックアップ等の手法により定常連松時のＡ
／Ｆを演算ないし決定する。このとき、のＡ／Ｆは原則
として希薄混合気運転に対応しており、すなわちＡ／Ｆ
＞１５である。ただし、流れ図には示されないが、絞り
弁７の開度が所定値以上であることなどから判定される
高負荷運献時にはＡ／Ｆ＝１２〜１３の出力空燃比に設
定するので、以下の補正処理にあたってはまずこの判断
を行い、当該出力空燃比制御状態にあるときには補正処
理を行わないようにする。また、ギヤポジションセンサ
２８の出力に基づいて変速機ギヤ位置を検出し、既述し
たようにギヤ位置が２速以下のときにも補正処理を行わ
ない。Next, from the relationship between Tp and N obtained in this way, we use the above-mentioned table lookup method to
/F is calculated or determined. At this time, the A/F corresponds to lean mixture operation in principle, that is, the A/F
>15. However, although it is not shown in the flowchart, during high load operation, which is determined based on the opening degree of the throttle valve 7 being above a predetermined value, etc., the output air-fuel ratio is set to A/F = 12 to 13, so the following In the correction process, this judgment is first made, and the correction process is not performed when the output air-fuel ratio control state is in question. Further, the transmission gear position is detected based on the output of the gear position sensor 28, and as described above, the correction process is not performed even when the gear position is 2nd speed or lower.

Ａ／Ｆ　＞　１５でかつギヤ位置が３速以上のときは、
次に加速または減速状態を検出する。これはスロットル
ボノシ３ンセンサ２７からの絞り弁位置信号の微分値を
求め、これが所定基準値以上であり、かつ絞り弁開度の
絶対値が所定基準値以上である場合に空燃比補正すべき
加速状態にあると判定する。また、前記微分値または絞
り弁開度が所定基準値内であるときは定常的運転状態、
微分値が所定下限値以下であるときは減速状態と判定す
る。When A/F > 15 and the gear position is 3rd or higher,
Next, an acceleration or deceleration condition is detected. This calculates the differential value of the throttle valve position signal from the throttle valve position sensor 27, and if this is greater than a predetermined reference value and the absolute value of the throttle valve opening is greater than or equal to the predetermined reference value, the air-fuel ratio should be corrected. It is determined that the vehicle is in an acceleration state. Further, when the differential value or the throttle valve opening is within a predetermined reference value, the operation is in a steady state;
When the differential value is less than or equal to a predetermined lower limit value, it is determined that the vehicle is in a deceleration state.

上記加速判定の結果加速状態と判定された場合、次に定
常的運転状態から初めて加速状態に入ったか否かを判断
する。これは、図示しないが例えば加速判定用の７ラグ
を用意し、このフラグが減速時にセット、加速時にリセ
ットとなるように設定しておくことにより判定すること
ができる。ここで加速開始当初と判定されたときは、次
に加速時目標空燃比（Ａ／Ｆ＝１５）に至るまでに何段
階にＡ／Ｆを変化させるかを決定するために、加速直前
での定常時空燃比と前記加速時目標空燃比との差りを演
算する。前記Ａ／Ｆの段階的設定は、例えば定常時空燃
比が２２のときは２０−１８−１５という共合に最大３
段階に、回転同期または噴射同期のタイミングで変化さ
せることにより円滑な加速感が得られるようにするため
に行うものであり、処理としては流れ図に示されるよう
に前記りの値と２個の基準値とを順次比較することによ
り何段階に変化させるべきかを決定し、当該段階設定に
従って順次Ａ／Ｆを補正する。なお、加速継続中のとき
は既に前述のようにして当初に段階設定が行なわれてい
るので、改めて何段階に変化させるべきかの判断は行わ
ない６ 一方、上記加速判定において非加速状態であると判定さ
れた場合は、次に減速状態か定常状態かを判定する。こ
こで定常状態のときは現在のＡ／Ｆを維持する。すなわ
ち、この判定の直前で上記加速時空燃比の設定がなされ
ていれば当該加速時空燃比にそのまま維持し、定常時空
燃比の設定がなされていた時は当該定常時空燃比を維持
する。If the acceleration state is determined as a result of the above acceleration determination, then it is determined whether the acceleration state has entered for the first time from the steady operating state. Although not shown, this can be determined by, for example, preparing 7 lags for acceleration determination and setting this flag so that it is set during deceleration and reset during acceleration. If it is determined that this is the beginning of acceleration, then the next step is to change the A/F immediately before acceleration in order to determine how many steps the A/F should be changed until reaching the target air-fuel ratio during acceleration (A/F = 15). A difference between the steady state air-fuel ratio and the acceleration target air-fuel ratio is calculated. The stepwise setting of the A/F is, for example, when the steady state air-fuel ratio is 22, the combination is 20-18-15, and the maximum is 3.
This is done in order to obtain a smooth feeling of acceleration by changing the timing of rotation synchronization or injection synchronization in the steps, and the process is as shown in the flowchart by changing the above values and two criteria. By sequentially comparing the values, it is determined how many steps the change should be made, and the A/F is sequentially corrected according to the step setting. Note that when acceleration is continuing, the stage has already been set initially as described above, so no new judgment is made as to what stage the stage should be changed to.6 On the other hand, in the above acceleration judgment, if the stage is not accelerated. If it is determined that the vehicle is in a deceleration state or a steady state, it is then determined. Here, in a steady state, the current A/F is maintained. That is, if the acceleration air-fuel ratio has been set immediately before this determination, the acceleration air-fuel ratio is maintained as it is, and if the steady-state air-fuel ratio has been set, the steady-state air-fuel ratio is maintained.

これに対して、加速状態から減速状態に入ったときは定
常時空燃比に再設定する処理に進む。要するに、運転者
のアクセルベグル踏込み等により一度加速状態と判定さ
れると、速度調整等のためにアクセルを戻さない限り継
続して加速時空燃比が設定される。On the other hand, when the vehicle enters a deceleration state from an acceleration state, the process proceeds to resetting the air-fuel ratio to the steady state air-fuel ratio. In short, once it is determined that the vehicle is in an acceleration state due to the driver's depression of the accelerator pedal, etc., the air-fuel ratio during acceleration is continuously set unless the accelerator is released for speed adjustment or the like.

制御装置２０では、このようにして設定したＡ／Ｆ値に
相当する噴射弁駆動パルス幅ないしデユーティ比を決定
して記憶装置２２の出力用ＲＡＭ部の所定アドレスに格
納しておき、これに必要に応じてバッテリ電圧等に基づ
く補正を施したのち燃料噴射弁６に出力するという処理
を所定の周期で繰り返し実行することにより燃料供給量
ないし空燃比を最適制御する。The control device 20 determines the injector drive pulse width or duty ratio corresponding to the A/F value thus set and stores it at a predetermined address in the output RAM section of the storage device 22, The amount of fuel supplied or the air-fuel ratio is optimally controlled by repeatedly executing the process of outputting the fuel to the fuel injection valve 6 after making corrections based on the battery voltage, etc., at a predetermined cycle.

（発明の効果） 以上の通り、この発明によれば加速要求が継続するかぎ
り、すなわち運転者が加速の意思を失って減速に移るま
で加速時空燃比を維持するようにしたので、希薄混合気
運転を前提とした内燃機関において特に顕者な、加速過
程で定常時空燃比に復帰することによる出力の低下を回
避して滑らかな加速性能及び運転性を確保できる。(Effects of the Invention) As described above, according to the present invention, the air-fuel ratio during acceleration is maintained as long as the acceleration request continues, that is, until the driver loses the intention to accelerate and shifts to deceleration. It is possible to avoid a decrease in output due to the return to a steady state air-fuel ratio during the acceleration process, which is particularly noticeable in internal combustion engines based on the premise of the present invention, and ensure smooth acceleration performance and drivability.

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

第１図はこの発明の構成概念図、第２図はこの発明の一
実施例の機械的構成の概略図、第３図Ａ及びＢはその制
御系統の動作内容の一例を表す流れ図である。 １・・・内燃機関、　　　　　３・・・エア７０−メー
タ、６・・・電磁燃料噴射弁、　　７・・・吸気絞り弁
、２０・・・制御装置、　　　　２１・・・中央処理装
置、２２・・・記憶装置、　　　　２３・・・入出力処
理装置、２４・・・クランク角センサ、 ２７・・・スロットルポジションセンサ、２８・・・ギ
ヤポジションセンサ。FIG. 1 is a conceptual diagram of the structure of the present invention, FIG. 2 is a schematic diagram of the mechanical structure of an embodiment of the present invention, and FIGS. 3A and 3B are flowcharts showing an example of the operation contents of the control system. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 3... Air 70-meter, 6... Electromagnetic fuel injection valve, 7... Intake throttle valve, 20... Control device, 21... Central processing unit, 22... ...Storage device, 23...Input/output processing device, 24...Crank angle sensor, 27...Throttle position sensor, 28...Gear position sensor.

Claims (1)

【特許請求の範囲】[Claims] 内燃機関の吸入空気量を検出する吸気量検出手段と、同
じく回転数を検出する回転数検出手段と、前記吸気量と
回転数とに基づいて機関の１吸入行程あたりの吸入空気
量を演算する吸気量演算手段と、この演算吸気量と回転
数とに基づいて目標空燃比を演算する空燃比演算手段と
、機関の加速状態及び減速状態を検出する加減速検出手
段と、前記加減速状態に基づいて前記目標空燃比を補正
する空燃比補正手段とを有し、かつ前記空燃比補正手段
は機関が加速状態に入ったのち減速状態に転じるまで加
速時の空燃比補正を継続するように構成したことを特徴
とする内燃機関の空燃比制御装置。An intake air amount detection means for detecting the intake air amount of the internal combustion engine, a rotation speed detection means for also detecting the rotation speed, and an intake air amount per one intake stroke of the engine is calculated based on the intake air amount and the rotation speed. an air-fuel ratio calculating means for calculating a target air-fuel ratio based on the calculated intake air amount and the rotational speed; an acceleration/deceleration detecting means for detecting an acceleration state and a deceleration state of the engine; and air-fuel ratio correction means for correcting the target air-fuel ratio based on the engine, and the air-fuel ratio correction means is configured to continue correcting the air-fuel ratio during acceleration until the engine enters an acceleration state and then changes to a deceleration state. An air-fuel ratio control device for an internal combustion engine, characterized in that: