JPS6259219B2 - - Google Patents
Info
- Publication number
- JPS6259219B2 JPS6259219B2 JP15977183A JP15977183A JPS6259219B2 JP S6259219 B2 JPS6259219 B2 JP S6259219B2 JP 15977183 A JP15977183 A JP 15977183A JP 15977183 A JP15977183 A JP 15977183A JP S6259219 B2 JPS6259219 B2 JP S6259219B2
- Authority
- JP
- Japan
- Prior art keywords
- control
- air
- fuel
- engine
- fuel ratio
- 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
Links
- 239000000446 fuel Substances 0.000 claims description 89
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 23
- 239000001301 oxygen Substances 0.000 claims description 23
- 229910052760 oxygen Inorganic materials 0.000 claims description 23
- 238000011144 upstream manufacturing Methods 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 5
- 230000004044 response Effects 0.000 claims description 5
- 230000007704 transition Effects 0.000 claims description 2
- 238000002347 injection Methods 0.000 description 27
- 239000007924 injection Substances 0.000 description 27
- 230000004043 responsiveness Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 230000004913 activation Effects 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1477—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation circuit or part of it,(e.g. comparator, PI regulator, output)
- F02D41/1483—Proportional component
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/0015—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for using exhaust gas sensors
- F02D35/0023—Controlling air supply
- F02D35/0038—Controlling air supply by means of air pumps
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、混合気の空燃比制御をフイードバツ
ク制御するようにした燃料噴射式エンジンに関す
るものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection engine in which air-fuel ratio control of an air-fuel mixture is controlled by feedback.
（従来技術）
混合気の空燃比をフイードバツク制御するよう
にした燃料噴射式エンジンにおいては、エンジン
の運転状態が非フイードバツク制御領域であるア
イドル運転領域からフイードバツク制御領域であ
る加速運転領域に移行したような場合には、混合
気の空燃比が変動するためできるだけ早く所定空
燃比（理論空燃比）に収束せしめてエンジンの運
転特性及び排気特性を良好ならしめる（即ち、フ
イードバツク制御の応答性を高める）必要があ
る。(Prior art) In a fuel injection engine in which the air-fuel ratio of the air-fuel mixture is feedback-controlled, the operating state of the engine appears to shift from an idling operating region, which is a non-feedback control region, to an accelerating operating region, which is a feedback control region. In such a case, since the air-fuel ratio of the air-fuel mixture fluctuates, it is necessary to converge to a predetermined air-fuel ratio (stoichiometric air-fuel ratio) as soon as possible to improve engine operating characteristics and exhaust characteristics (that is, improve responsiveness of feedback control). There is a need.
このように、フイードバツク制御における応答
性を向上させるためには、フイードバツク制御定
数即ち、制御利得を大ならしめることが有効であ
るということは既に公知である（例えば、特公昭
55−36818号公報）。 As described above, it is already known that increasing the feedback control constant, that is, the control gain, is effective in improving the responsiveness in feedback control (for example,
55-36818).
ところが、このように制御利得を大きくすれば
するほど制御信号に対する反応が敏感となり、制
御応答性が向上するわけであるが、その反面、フ
イードバツク制御開始時に目標収束値即ち理論空
燃比を中心として空燃比が過濃側と希薄側の間で
交互に大きくふれ（ハンチング現象）、特に空燃
比が希薄側にある場合にはエンジンの運転特性が
悪化するという問題が発生することになる。 However, as the control gain is increased, the reaction to the control signal becomes more sensitive and the control responsiveness improves, but on the other hand, when the feedback control starts, the air-fuel ratio changes around the target convergence value, that is, the stoichiometric air-fuel ratio. The fuel ratio alternately varies greatly between the rich side and the lean side (hunting phenomenon), and particularly when the air-fuel ratio is on the lean side, a problem arises in that the operating characteristics of the engine deteriorate.
従つて、エンジンの運転状態が非フイードバツ
ク制御領域からフイードバツク制御領域に移行し
た場合において、空燃比を素早く理論空燃比に収
束させてエンジンの運転特性並びに排気特性を良
好水準に迅速に到達せしめるためには、制御利得
を通常のフイードバツク時より大きく設定し且
つ、空燃比の希薄側へのハンチング幅を可及的に
小さくすることが有効であるということがいえる
が、現在のところこのような観点からなされた公
知技術は見当らない。 Therefore, when the operating state of the engine shifts from the non-feedback control region to the feedback control region, in order to quickly converge the air-fuel ratio to the stoichiometric air-fuel ratio so that the engine operating characteristics and exhaust characteristics quickly reach good levels. It can be said that it is effective to set the control gain larger than during normal feedback and to minimize the hunting width toward the lean side of the air-fuel ratio. No known techniques have been found.
（発明の目的）
本発明は、空燃比を排気通路中に設けた酸素セ
ンサから出力される制御信号に基いてフイードバ
ツク制御するようにした燃料噴射式エンジンにお
いて、エンジンの運転状態が非フイードバツク制
御領域からフイードバツク制御領域に移行してフ
イードバツク制御が開始された時に、エンジンの
運転特性を損なうことなくフイードバツク制御の
応答性を高めることができるようにした燃料噴射
式エンジンを提供することを目的としてなされた
ものである。(Object of the Invention) The present invention provides a fuel injection engine in which the air-fuel ratio is feedback-controlled based on a control signal output from an oxygen sensor installed in an exhaust passage, in which the operating state of the engine is in a non-feedback control region. The purpose of this invention is to provide a fuel injection engine that can increase the responsiveness of feedback control without impairing the engine's operating characteristics when the feedback control is started by transitioning from the engine to the feedback control region. It is something.
（発明の構成）
本発明は、第１図の構成説明図に示す如く酸素
センサ６の出力信号に基いて燃料の制御信号を作
成する演算手段Ａと、該演算手段Ａからの制御信
号を受けてエンジンにインジエクター７から燃料
を噴射供給する燃料供給手段Ｂと、エンジンの運
転領域を判定する運転領域判定手段Ｃと、フイー
ドバツク制御時の制御利得を設定する制御利得設
定手段Ｄと、フイードバツク制御開始時に該制御
開始後所定時間だけ制御利得制御信号と二次エア
制御信号を出力する補正手段Ｅとを備え、フイー
ドバツク制御開始時には前記補正手段によつて制
御利得を通常のフイードバツク制御時の制御利得
よりも大きく設定して制御応答性を高めると同時
に、前記酸素センサの周辺に二次エアを供給して
空燃比をリツチ側に設定し、空燃比のハンチング
現象によるエンジンの運転特性の悪化を可及的に
抑制し得るように構成したことを特徴とするもの
である。(Structure of the Invention) As shown in the configuration explanatory diagram of FIG. a fuel supply means B that injects fuel from the injector 7 to the engine; an operating range determining means C that determines the operating range of the engine; a control gain setting means D that sets a control gain during feedback control; A correction means E is provided for outputting a control gain control signal and a secondary air control signal for a predetermined period of time after the start of the control, and when the feedback control is started, the correction means adjusts the control gain to be higher than the control gain during normal feedback control. At the same time, secondary air is supplied around the oxygen sensor to set the air-fuel ratio to the rich side to prevent deterioration of engine operating characteristics due to air-fuel ratio hunting phenomenon. This feature is characterized in that it is configured such that it can suppress the
（実施例）
第１図には本発明の実施例に係る自動車用燃料
噴射式エンジンの構成図が示されている。この燃
料噴射式エンジンは、エンジン本体１の吸気管２
に、その吸気上流側から吸気下流側に向つて吸入
空気量センサ４と、スロツトルバルブ５と、燃料
インジエクター７を順次取付けるとともに、スロ
ツトルバルブ５にはスロツトル開度センサ８を取
付けている。又、エンジン本体１の排気管３には
排気上流側から排気下流側に向つて排気中の残存
酸素濃度を検出する酸素センサ６と排気ガス浄化
用の触媒コンバータ１０を順次取付けている。
又、排気管３におけるエンジン本体１と酸素セン
サ６取付部との中間位置には、該酸素センサ６の
周辺に向けて二次エアを供給する二次エア供給装
置３２の二次エア供給管１１が開口せしめられて
いる。この二次エア供給管１１の一端には二次エ
ア制御弁１２を介してエアポンプ１３が取付けら
れている。又、第１図において符号９は回転数セ
ンサとして作用するデイストリビユータである。(Embodiment) FIG. 1 shows a configuration diagram of a fuel injection type automobile engine according to an embodiment of the present invention. This fuel injection type engine has an intake pipe 2 of an engine body 1.
An intake air amount sensor 4, a throttle valve 5, and a fuel injector 7 are installed in this order from the intake upstream side to the intake downstream side, and a throttle opening sensor 8 is attached to the throttle valve 5. Further, an oxygen sensor 6 for detecting the residual oxygen concentration in the exhaust gas and a catalytic converter 10 for purifying the exhaust gas are sequentially attached to the exhaust pipe 3 of the engine body 1 from the exhaust upstream side to the exhaust downstream side.
In addition, a secondary air supply pipe 11 of a secondary air supply device 32 that supplies secondary air toward the periphery of the oxygen sensor 6 is located at an intermediate position between the engine body 1 and the oxygen sensor 6 attachment part in the exhaust pipe 3. is left open. An air pump 13 is attached to one end of the secondary air supply pipe 11 via a secondary air control valve 12. Further, in FIG. 1, reference numeral 9 denotes a distributor that functions as a rotational speed sensor.
この燃料噴射式エンジンは、吸入空気量検出セ
ンサ４から出力される吸入空気量信号S1と、スロ
ツトル開度センサ８から出力される開度信号S2
と、回転数センサ９から出力される回転数信号S3
と、酸素センサ６から出力される酸素濃度信号S4
をそれぞれコントローラ１４に制御信号として入
力し、該コントローラ１４によつて燃料制御と二
次エア制御とを行なうようにしている。尚、この
実施例においては、エンジンの運転状態が非アイ
ドル運転領域にある場合にのみ酸素センサ６の検
出信号に基づく空燃比のフイードバツク制御を行
ない、アイドル運転領域にある場合には空燃比の
フイードバツク制御は行なわないようにしてい
る。 This fuel injection engine uses an intake air amount signal S 1 output from the intake air amount detection sensor 4 and an opening signal S 2 output from the throttle opening sensor 8.
and the rotation speed signal S 3 output from the rotation speed sensor 9.
and the oxygen concentration signal S 4 output from the oxygen sensor 6
are respectively input to the controller 14 as control signals, and the controller 14 performs fuel control and secondary air control. In this embodiment, the air-fuel ratio feedback control is performed based on the detection signal of the oxygen sensor 6 only when the engine operating state is in the non-idling operating range, and when the engine operating state is in the idling operating range, the air-fuel ratio feedback control is performed. I try not to control it.
以下、このコントローラ１４による燃料と二次
エアとの制御システムを第２図の制御ブロツク図
に基いて説明すると、このコントローラ１４は、
それぞれ後に詳述する基本噴射パルス幅演算回路
２１と噴射パルス幅補正回路２２と第１駆動回路
２３と空燃比判定回路２４と運転領域判定回路２
５と演算回路２６とタイマー２７と制御利得設定
回路２８と二次エア制御回路２９と第２駆動回路
３０を有している。 Hereinafter, the control system for fuel and secondary air by this controller 14 will be explained based on the control block diagram of FIG.
A basic injection pulse width calculation circuit 21, an injection pulse width correction circuit 22, a first drive circuit 23, an air-fuel ratio determination circuit 24, and an operating range determination circuit 2, which will be described in detail later, respectively.
5, an arithmetic circuit 26, a timer 27, a control gain setting circuit 28, a secondary air control circuit 29, and a second drive circuit 30.
基本噴射パルス幅設定回路２１は、吸入空気量
信号S1と回転数信号S3をうけてインジエクタ７か
ら噴射される燃料の基本噴射パルス幅を設定する
ものである。 The basic injection pulse width setting circuit 21 sets the basic injection pulse width of the fuel injected from the injector 7 in response to the intake air amount signal S1 and the rotational speed signal S3 .
噴射パルス幅補正回路２２は、前記基本パルス
幅設定回路２１から出力されるパルス幅信号S5を
後述する演算回路２６から出力される補正信号
S10に基いて補正制御するものである。 The injection pulse width correction circuit 22 converts the pulse width signal S5 outputted from the basic pulse width setting circuit 21 into a correction signal outputted from an arithmetic circuit 26, which will be described later.
Correction control is performed based on S10 .
第１駆動回路２３は、前記噴射パルス幅補正回
路２２から出力される補正後の噴射パルス幅信号
S6を受けてインジエクタ７に作動信号S7を出力
し、該インジエクタ７をして燃料の噴射を行なわ
しめるものである。この実施例においては前記基
本パルス幅設定回路２１と噴射パルス幅補正回路
２２と第１駆動回路２３とインジエクタ７とで第
１図に示す燃料供給手段Ｂを構成している。 The first drive circuit 23 receives a corrected injection pulse width signal output from the injection pulse width correction circuit 22.
In response to S6 , an actuation signal S7 is output to the injector 7, and the injector 7 injects fuel. In this embodiment, the basic pulse width setting circuit 21, the injection pulse width correction circuit 22, the first drive circuit 23, and the injector 7 constitute the fuel supply means B shown in FIG.
空燃比判定回路２４は、酸素濃度信号S4を受け
て現在の混合気の空燃比が理論空燃比より過剰側
にあるのか希薄側にあるのかを判定し、所定の空
燃比信号S8を後述する演算回路２６に出力する。 The air-fuel ratio determination circuit 24 receives the oxygen concentration signal S4 and determines whether the current air-fuel ratio of the air-fuel mixture is on the excess side or lean side of the stoichiometric air-fuel ratio, and generates a predetermined air-fuel ratio signal S8 , which will be described later. The output signal is output to the arithmetic circuit 26.
運転領域判定回路２５は、スロツトル開度信号
S2と回転信号S3を受けて現在のエンジンの運転領
域を判定し、エンジンの運転状態が空燃比をフイ
ードバツク制御する必要のある非アイドル運転領
域にある場合にのみ後述する演算回路２６とタイ
マー２７に制御領域信号S9を出力する。この運転
領域判定回路２５は、第１図に示した運転領域判
定手段Ｃに相当する。 The operating region determination circuit 25 receives a throttle opening signal.
S2 and rotation signal S3 , the current engine operating range is determined, and only when the engine operating state is in a non-idling operating range where feedback control of the air-fuel ratio is required, an arithmetic circuit 26 and a timer, which will be described later, are used. The control area signal S9 is output to 27. This operating range determining circuit 25 corresponds to the operating range determining means C shown in FIG.
タイマー２７は、前記運転領域判定回路２５か
らの制御領域信号S9を受けて作動し、該制御領域
信号S9が入力された時点から（即ち、フイードバ
ツク制御領域への移行時点から）所定時間（この
実施例では２分間に設定している）だけ後述する
制御利得設定回路２８と二次エア制御回路２９に
作動信号S11を出力する。 The timer 27 operates in response to the control area signal S 9 from the operating area determination circuit 25, and operates for a predetermined period of time (from the time when the control area signal S 9 is input (i.e., from the time when the transition to the feedback control area occurs). In this embodiment, the operation signal S11 is outputted to a control gain setting circuit 28 and a secondary air control circuit 29, which will be described later.
制御利得設定回路２８は、フイードバツク制御
時における制御利得をフイードバツク制御開始当
初とそれ以後とにおいて切換えるものであつて、
前記タイマー２７から作動信号S11によつて作動
し、該作動信号S11が入力されている間（換言す
ればエンジンの運転状態がアイドル運転から非ア
イドル運転に移行した時点から２分間）は制御利
得を、比較的大きく従つて制御時のハンチングは
大きいが応答性の良い制御が可能な第１制御利得
に設定し、該作動信号S11の入力が庶断された場
合（換言すればタイマー２７の設定時間の経過
後）には該第１制御利得より小さく従つて応答性
は第１制御利得の場合よりも劣るが制御時のハン
チングが小さく高精度の制御が可能な第２制御利
得に設定し、この第１制御利得と第２制御利得の
いずれかを制御利得信号S12として後述する演算
回路２６側に出力する。この制御利得設定回路２
８は、第１図に示した制御利得設定手段Ｄに相当
する。 The control gain setting circuit 28 switches the control gain during the feedback control between the beginning of the feedback control and thereafter.
It is activated by the activation signal S 11 from the timer 27, and the control is performed while the activation signal S 11 is input (in other words, for 2 minutes from the time when the engine operating state changes from idling to non-idling). When the gain is set to a first control gain that is relatively large and therefore allows for large hunting during control but allows control with good responsiveness, and the input of the actuation signal S11 is cut off (in other words, the timer 27 (after the set time has elapsed), the second control gain is set to the second control gain, which is smaller than the first control gain and has lower responsiveness than the first control gain, but allows for less hunting during control and more accurate control. Then, either the first control gain or the second control gain is output as a control gain signal S12 to the arithmetic circuit 26, which will be described later. This control gain setting circuit 2
8 corresponds to the control gain setting means D shown in FIG.
演算回路２６は、前記空燃比判定回路２４から
出力される空燃比信号S8と前記制御利得設定回路
２８から出力される制御利得信号S12と前記運転
領域判定回路２５から出力される制御領域信号S9
とを受けて作動し、該制御領域信号S9が入力され
ている間は（換言すれば、エンジンの運転状態が
フイードバツク制御領域内にある間は）、第１制
御利得あるいは第２制御利得でもつて空燃比信号
S8に基いて噴射パルス幅の補正値を演算してこれ
を補正信号S10として前記噴射パルス幅補正回路
２２側に出力して空燃比のフイードバツク制御を
行なうが、制御領域信号S9が入力されていない場
合（換言すれば、エンジンの運転領域が非フイー
ドバツク制御領域にある場合）には補正信号S10
を出力しない（即ち、空燃比のフイードバツク制
御の解除）ようになつている。この演算回路２６
は、第１図に示した演算手段Ａに相当するもので
ある。 The calculation circuit 26 calculates an air-fuel ratio signal S 8 outputted from the air-fuel ratio determination circuit 24 , a control gain signal S 12 outputted from the control gain setting circuit 28 , and a control region signal outputted from the operating region determination circuit 25 . S 9
While the control region signal S9 is input (in other words, while the engine operating state is within the feedback control region), the first control gain or the second control gain is activated. air fuel ratio signal
A correction value for the injection pulse width is calculated based on S 8 and is output as a correction signal S 10 to the injection pulse width correction circuit 22 to perform air-fuel ratio feedback control, but the control region signal S 9 is input. (in other words, when the engine operating range is in the non-feedback control range), the correction signal S 10
(ie, the air-fuel ratio feedback control is canceled). This arithmetic circuit 26
corresponds to the calculation means A shown in FIG.
二次エア制御回路２９は、前記タイマー２７か
ら作動信号S11が入力されている間だけ第２駆動
回路３０に二次エア供給信号S13を出力して該第
２駆動回路３０から出力される駆動信号S14によ
つて二次エア制御弁１２を開き、二次エアを所定
量だけ排気通路３内でしかも酸素センサ６の上流
側に供給せしめる如く作用する。 The secondary air control circuit 29 outputs a secondary air supply signal S 13 to the second drive circuit 30 only while the activation signal S 11 is input from the timer 27, and the secondary air supply signal S 13 is output from the second drive circuit 30. The secondary air control valve 12 is opened by the drive signal S14 , and acts to supply a predetermined amount of secondary air into the exhaust passage 3 and upstream of the oxygen sensor 6.
この二次エアの供給が行われると、酸素センサ
６は排気中の残存酸素量を実際（エンジンの気筒
から排出される排気中の酸素量）よりも過大に検
知（即ち、空燃比が希薄側にあるように検知）す
るため、この酸素センサ６から酸素濃度信号S4を
受けたコントローラ１４は二次エアの供給がない
場合よりも空燃比をリツチ側に制御するように作
用する。 When this secondary air is supplied, the oxygen sensor 6 detects the amount of oxygen remaining in the exhaust gas in excess of the actual amount (the amount of oxygen in the exhaust gas discharged from the engine cylinder) (that is, the air-fuel ratio is on the lean side). Therefore, the controller 14, which receives the oxygen concentration signal S4 from the oxygen sensor 6, operates to control the air-fuel ratio to be richer than when no secondary air is supplied.
続いて、この燃料噴射式エンジンの作用を、エ
ンジンをアイドル運転領域、即ち非フイードバツ
ク制御領域から非アイドル運転領域、即ちフイー
ドバツク制御領域に移行させる場合について説明
すると、先ず、エンジンがアイドル運転されてい
る場合には、運転領域判定回路２５から制御領域
信号S9が出力されないため演算回路２６は非作動
とされ、空燃比のフイードバツク制御は行なわれ
ない。従つて、この場合の燃料噴射量は、吸入空
気量信号S1と回転数信号S3に基いて基本噴射パル
ス幅演算回路２１から出力される噴射パルス幅に
従つてほぼ混合気の空燃比が理論空燃比近くにな
るように設定されるが、特にこのアイドル運転領
域では図示しない増量装置によつて燃料噴射量が
上記設定量より若干増量されるようにされてお
り、このため混合気の空燃比は理論空燃比よりリ
ツチ状態となつている。尚、この時、二次エアの
供給は停止されている。 Next, we will explain the operation of this fuel-injected engine when the engine is moved from an idle operating region, that is, a non-feedback control region, to a non-idle operating region, that is, a feedback control region. First, when the engine is being operated at idle, In this case, since the control region signal S9 is not outputted from the operating region determining circuit 25, the arithmetic circuit 26 is rendered inactive, and feedback control of the air-fuel ratio is not performed. Therefore, the fuel injection amount in this case is approximately determined by the air-fuel ratio of the air-fuel mixture according to the injection pulse width output from the basic injection pulse width calculation circuit 21 based on the intake air amount signal S1 and the rotational speed signal S3 . Although the air-fuel ratio is set to be close to the stoichiometric air-fuel ratio, the fuel injection amount is slightly increased from the above-mentioned setting amount by an increase device (not shown), especially in this idling operating region, so that the air-fuel ratio is The fuel ratio is richer than the stoichiometric air-fuel ratio. Note that at this time, the supply of secondary air is stopped.
上記の如きアイドル運転状態からエンジンが加
速されその運転状態が非アイドル運転領域に達し
た場合には、運転領域判定回路２５から制御領域
信号S9が出力され、空燃比のフイードバツク制御
が開始され、空燃比を理論空燃比に収束せしめる
如く空燃比判定回路２４からの空燃比信号S8に基
いて演算回路２６から出力される補正信号S10に
より燃料噴射量が制御される。 When the engine is accelerated from the idle operating state as described above and its operating state reaches the non-idling operating region, the operating region determination circuit 25 outputs the control region signal S9 , and air-fuel ratio feedback control is started. The fuel injection amount is controlled by the correction signal S10 output from the calculation circuit 26 based on the air-fuel ratio signal S8 from the air-fuel ratio determination circuit 24 so as to cause the air-fuel ratio to converge to the stoichiometric air-fuel ratio.
一方、フイードバツク制御の開始と同時にタイ
マー２７が作動し、２分間だけ制御利得が第１制
御利得に設定されると同時に、二次エア制御弁１
２が開いて酸素センサ６の排気上流側に所定量の
二次エアが供給される。このように制御利得が制
御応答性の良い第１制御利得に設定されると、そ
れだけ迅速に空燃比を理論空燃比に収束せしめる
ことができ、フイードバツク制御の応答性が向上
する。 On the other hand, at the same time as the start of the feedback control, the timer 27 operates, and the control gain is set to the first control gain for 2 minutes, and at the same time, the secondary air control valve 1
2 opens, and a predetermined amount of secondary air is supplied to the exhaust upstream side of the oxygen sensor 6. When the control gain is set to the first control gain with good control responsiveness in this way, the air-fuel ratio can be converged to the stoichiometric air-fuel ratio more quickly, and the responsiveness of the feedback control is improved.
このように制御利得を大きくすれば空燃比の変
化に対する制御の反応が敏感となり、ハンチング
幅が大きくなつてエンジンの運転特性が悪化する
ことになるが、この実施例においてはこの場合、
酸素センサ６側に二次エアが供給され、それによ
つて実際の空燃比が理論空燃比より若干リツチ側
に設定されるようにされているため、ハンチング
幅が大きくなつてもエンジンの運転特性は良好に
維持される。 If the control gain is increased in this way, the control response to changes in the air-fuel ratio will become more sensitive, the hunting width will increase, and the engine operating characteristics will deteriorate; however, in this example, in this case,
Secondary air is supplied to the oxygen sensor 6 side, thereby setting the actual air-fuel ratio to be slightly richer than the stoichiometric air-fuel ratio, so even if the hunting width becomes large, the engine operating characteristics will remain the same. Well maintained.
タイマー設定時間の経過後は、制御利得が第１
制御利得から第２制御利得側に切換わるととも
に、二次エアの供給が中止され、空燃比は第２制
御利得により比較的高精度にフイードバツク制御
される。 After the timer setting time has elapsed, the control gain returns to the first level.
The control gain is switched from the control gain to the second control gain, the supply of secondary air is stopped, and the air-fuel ratio is feedback-controlled with relatively high accuracy by the second control gain.
なお、上記実施例において、アイドル運転領域
には二次エアの供給を遮断するようにしている
が、排気浄化を促進させるためにこの運転領域に
おいて二次エアを供給するようにしてもよいこと
は勿論である。 In the above embodiment, the supply of secondary air is cut off in the idle operating region, but it is also possible to supply secondary air in this operating region in order to promote exhaust purification. Of course.
（発明の効果）
本発明は、空燃比を酸素センサから出力される
信号に基いてフイードバツク制御するうにした燃
料噴射式エンジンにおいて、エンジンの運転状態
が非フイードバツク制御領域からフイードバツク
制御領域に移行した時、所定時間だけ制御利得を
大きくすると同時に酸素センサの上流側に二次エ
アを供給して空燃比を理論空燃比よりも若干過濃
側に設定するようにしているため、エンジンの運
転特性を損なうことなくフイードバツク制御の応
答性を図ることができ、また空燃比制御の応答性
が良いため、それだけエンジンの排気特性が向上
するという効果がある。(Effects of the Invention) The present invention provides a fuel injection engine in which the air-fuel ratio is feedback-controlled based on a signal output from an oxygen sensor, when the operating state of the engine shifts from a non-feedback control region to a feedback control region. , the control gain is increased for a predetermined period of time, and at the same time secondary air is supplied to the upstream side of the oxygen sensor to set the air-fuel ratio to be slightly richer than the stoichiometric air-fuel ratio, which impairs engine operating characteristics. Since the responsiveness of the feedback control can be improved without any problems, and the responsiveness of the air-fuel ratio control is good, the exhaust characteristics of the engine can be improved accordingly.
第１図は本発明の実施例に係る自動車用燃料噴
射式エンジンの構成説明図、第２図は第１図に示
した燃料噴射式エンジンの燃料制御システムの制
御ブロツク図である。
１……エンジン本体、２……吸気通路、３……
排気通路、４……吸入空気量センサ、５……スロ
ツトルバルブ、６……酸素センサ、７……インジ
エクタ、８……スロツトル開度センサ、９……回
転数センサ、１０……触媒コンバータ、１１……
二次エア供給路、１２……二次エア制御弁、１３
……エアポンプ、１４……コントローラ、２１…
…基本噴射パルス幅演算回路、２２……噴射パル
ス幅補正回路、２３……第１駆動回路、２４……
空燃比判定回路、２５……運転領域判定回路、２
６……演算回路、２７……タイマー、２８……制
御利得設定回路、２９……二次エア制御回路、３
０……第２駆動回路、３２……二次エア供給装
置、Ａ……演算手段、Ｂ……燃料供給手段、Ｃ…
…運転領域判定手段、Ｄ……制御利得設定手段、
Ｅ……補正手段。
FIG. 1 is an explanatory diagram of the configuration of a fuel injection type engine for an automobile according to an embodiment of the present invention, and FIG. 2 is a control block diagram of a fuel control system for the fuel injection type engine shown in FIG. 1. 1...Engine body, 2...Intake passage, 3...
Exhaust passage, 4... Intake air amount sensor, 5... Throttle valve, 6... Oxygen sensor, 7... Injector, 8... Throttle opening sensor, 9... Rotation speed sensor, 10... Catalytic converter, 11...
Secondary air supply path, 12...Secondary air control valve, 13
...Air pump, 14...Controller, 21...
... Basic injection pulse width calculation circuit, 22 ... Injection pulse width correction circuit, 23 ... First drive circuit, 24 ...
Air-fuel ratio determination circuit, 25...Operating region determination circuit, 2
6... Arithmetic circuit, 27... Timer, 28... Control gain setting circuit, 29... Secondary air control circuit, 3
0...Second drive circuit, 32...Secondary air supply device, A...Calculating means, B...Fuel supply means, C...
...driving region determining means, D...control gain setting means,
E... Correction means.
Claims (1)
いて燃料の制御信号を作成する演算手段と、該演
算手段からの制御信号を受けてエンジンに燃料を
噴射供給する燃料供給手段と、エンジンの運転領
域を判定する運転領域判定手段と、燃料のフイー
ドバツク制御時における制御利得を設定する制御
利得設定手段と、エンジンの運転状態が非フイー
ドバツク制御領域からフイードバツク制御領域に
移行したときに運転領域の移行時点から所定時間
だけ前記制御利得を通常のフイードバツク制御時
における制御利得よりも大きく設定すると同時に
前記酸素センサの排気上流位置に二次エアを供給
する如く作用する補正手段とを備えたことを特徴
とする燃料噴射式エンジン。1. A calculation means for creating a fuel control signal based on the output signal of an oxygen sensor installed in the exhaust passage, a fuel supply means for injecting fuel into the engine in response to the control signal from the calculation means, and a fuel supply means for injecting fuel into the engine, an operating region determining means for determining the region; a control gain setting means for setting a control gain during fuel feedback control; and a control gain setting means for determining the operating region transition point when the engine operating state shifts from the non-feedback control region to the feedback control region. The present invention is characterized by comprising a correction means that sets the control gain to be larger than the control gain during normal feedback control for a predetermined period of time, and at the same time acts to supply secondary air to a position upstream of the exhaust gas of the oxygen sensor. Fuel-injected engine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15977183A JPS6050242A (en) | 1983-08-30 | 1983-08-30 | Fuel injection type engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15977183A JPS6050242A (en) | 1983-08-30 | 1983-08-30 | Fuel injection type engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6050242A JPS6050242A (en) | 1985-03-19 |
| JPS6259219B2 true JPS6259219B2 (en) | 1987-12-10 |
Family
ID=15700899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15977183A Granted JPS6050242A (en) | 1983-08-30 | 1983-08-30 | Fuel injection type engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6050242A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60198348A (en) * | 1984-03-23 | 1985-10-07 | Mitsubishi Motors Corp | Engine controller |
-
1983
- 1983-08-30 JP JP15977183A patent/JPS6050242A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6050242A (en) | 1985-03-19 |
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