JPS63109250A - Air-fuel ratio control device for internal combustion engine - Google Patents
Air-fuel ratio control device for internal combustion engineInfo
- Publication number
- JPS63109250A JPS63109250A JP25408886A JP25408886A JPS63109250A JP S63109250 A JPS63109250 A JP S63109250A JP 25408886 A JP25408886 A JP 25408886A JP 25408886 A JP25408886 A JP 25408886A JP S63109250 A JPS63109250 A JP S63109250A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- intake
- egr
- fuel injection
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 75
- 238000002485 combustion reaction Methods 0.000 title claims description 9
- 238000002347 injection Methods 0.000 claims abstract description 55
- 239000007924 injection Substances 0.000 claims abstract description 55
- 238000012937 correction Methods 0.000 claims description 26
- 238000001514 detection method Methods 0.000 claims description 15
- 238000000034 method Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 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、電子制御燃料噴射方式を採用する自動車等に
好適に利用される内燃機関の空燃比制御装置に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air-fuel ratio control device for an internal combustion engine that is suitably used in automobiles and the like that employ an electronically controlled fuel injection system.
［従来の技術］
一般に、自動車用エンジンでは、排気ガス中に含まれる
ＮＯｘの生成を低減するために、吸気系と排気系とを排
気還流通路（以後、ＥＧＩ？通路）を介して連通させる
とともに、該ＥＧＲ通路に排気還流制御バルブ（以後、
ＥＧＲバルブ）等を介設し、排気ガスの一部を吸気系に
還流して最高燃焼温度を抑制する、いわゆるＥＧＲ制御
を行うようにしている。また、この種エンジン等の吸気
系に燃料を供給する装置として、マイクロコンピュータ
等により作動を制御される燃料噴射装置を備えたものに
あっては、種々のセンサ類からの情報に基づいて様々な
運転状況に応じた最適な運転状態を確保すると同時に、
排気系に設けた三元触媒での排気ガスの浄化を効率よく
行うために、空燃比が理論空燃比近傍に維持されるよう
に前記燃料噴射装置からの燃料噴射量（燃料噴射時間）
を決定するようにしている。その際、燃料噴射量は、Ｅ
ＧＲ実行状態で空燃比が理論空燃比となるように設定し
ているのが普通である。例えば、燃料噴射量を決定する
際には、特開昭６０−１７３３３３号公報にも示される
ように、先ず、吸入空気量に応じて求められる基本噴射
量に様々の運転状況に応じた所要の補正値（例えば、Ｅ
ＧＲ実行中とみなして設定されるＥＣＲ補正値等）を乗
じて空燃比が理論空燃比となるように燃料噴射量を決定
するようにしているのが一般的である。[Prior Art] Generally, in an automobile engine, in order to reduce the generation of NOx contained in exhaust gas, an intake system and an exhaust system are communicated through an exhaust gas recirculation passage (hereinafter referred to as an EGI? passage). , an exhaust recirculation control valve (hereinafter referred to as
A so-called EGR control is performed in which a part of the exhaust gas is recirculated to the intake system to suppress the maximum combustion temperature. In addition, in devices that supply fuel to the intake system of this type of engine, etc., which are equipped with a fuel injection device whose operation is controlled by a microcomputer, various At the same time as ensuring optimal driving conditions according to driving conditions,
In order to efficiently purify exhaust gas with a three-way catalyst installed in the exhaust system, the fuel injection amount (fuel injection time) from the fuel injection device is adjusted so that the air-fuel ratio is maintained near the stoichiometric air-fuel ratio.
I'm trying to decide. At that time, the fuel injection amount is E
Normally, the air-fuel ratio is set to be the stoichiometric air-fuel ratio in the GR execution state. For example, when determining the fuel injection amount, first, as shown in JP-A-60-173333, the basic injection amount determined according to the intake air amount is combined with the required amount according to various driving conditions. Correction value (e.g. E
Generally, the fuel injection amount is determined so that the air-fuel ratio becomes the stoichiometric air-fuel ratio by multiplying the air-fuel ratio by an ECR correction value (such as an ECR correction value that is set assuming that GR is being executed).
［発明が解決しようとする問題点］
ところが、ＥＧＩ？制御は大気圧と吸気圧との差圧が略
設定値を上まわった場合に作動するＥＧＲバルブによる
機械式である。換言すれば、ＥＧＲが実行されるのは、
大気圧と吸気圧との差圧がＥＧＲバルブの作動圧を上回
った場合であり、大気圧と吸気圧との差圧により、ＥＣ
；Ｒを実行していない領域が存在する。しかしながら、
燃料噴射量が決定される際は、吸気中に排気ガスが混入
されている状態で空燃比が理論空燃比となるように設定
されるため、ＥＧＲが実行されていない領域では排気ガ
スが吸気に還流されない分、空燃比の制御中心がり一ン
側にずれることになる。その結果、エミッションや排気
ガス中の有害成分の除去効率が悪化し不具合となる。[Problem that the invention attempts to solve] However, EGI? Control is mechanical with an EGR valve that operates when the differential pressure between atmospheric pressure and intake pressure exceeds a set value. In other words, EGR is performed when
This is a case where the differential pressure between atmospheric pressure and intake pressure exceeds the operating pressure of the EGR valve, and due to the differential pressure between atmospheric pressure and intake pressure, EC
;There is an area where R is not executed. however,
When determining the fuel injection amount, the air-fuel ratio is set to the stoichiometric air-fuel ratio with exhaust gas mixed in the intake air. As a result of the lack of reflux, the center of control of the air-fuel ratio shifts to one side. As a result, the removal efficiency of harmful components in emissions and exhaust gas deteriorates, leading to problems.
本発明はかかる不具合を簡単かつ確実に解消することの
できる内燃機関の空燃比制御装置を提供することを目的
としている。An object of the present invention is to provide an air-fuel ratio control device for an internal combustion engine that can easily and reliably eliminate such problems.
［問題点を解決するための手段］
本発明は、かかる目的を達成するため多こ、大気圧と吸
気圧との差圧により作動する排気還流制御バルブと、噴
射指令信号に対応する量の燃料を吸気系に噴射する燃料
噴射装置を具備してなる内燃機関において、大気圧を検
出する大気圧検出手段と、吸気圧を検出する吸気圧検出
手段と、前記両検出手段による検出値に基づいて大気圧
と吸気圧との差圧が前記排気還流制御バルブの作動圧を
上回っているか否かを判別する差圧判定手段と、この差
圧判定手段により前記差圧が前記作動圧を下回っている
と判定された場合にのみ前記燃料噴射装置からの燃料噴
射量を増量する方向に前記噴射指令信号を補正する燃料
噴射量補正手段とを設けてなることを特徴とする。[Means for Solving the Problems] In order to achieve the above object, the present invention provides an exhaust gas recirculation control valve that operates based on a pressure difference between atmospheric pressure and intake pressure, and an amount of fuel corresponding to an injection command signal. In an internal combustion engine equipped with a fuel injection device that injects fuel into an intake system, an atmospheric pressure detection means for detecting atmospheric pressure, an intake pressure detection means for detecting intake pressure, and a method based on detected values by both of the detection means. differential pressure determining means for determining whether the differential pressure between atmospheric pressure and intake pressure exceeds the operating pressure of the exhaust recirculation control valve; and the differential pressure determining means determines whether the differential pressure is lower than the operating pressure. The present invention is characterized by further comprising a fuel injection amount correction means for correcting the injection command signal in a direction of increasing the fuel injection amount from the fuel injection device only when it is determined that the fuel injection amount is increased.
［作用］
このような構成によると、排気還流制御バルブの作動状
態は、該バルブの作動状態を直接に左右する大気圧と吸
気圧とを検出することにより判別される。すなわち、大
気圧検出手段と吸気圧検出手段からの検出値に基いて、
大気圧と吸気圧との差圧が排気還流制御バルブの作動圧
を上回っているか否かが差圧判定手段により判定される
。そして、大気圧と吸気圧との差圧が排気還流制御バル
ブの作動圧を上回り排気還流が実行されている場合は、
従前の噴射指令信号に基づいて燃料噴射が実行されて空
燃比が理論空燃比近傍に維持される。[Operation] According to this configuration, the operating state of the exhaust gas recirculation control valve is determined by detecting the atmospheric pressure and the intake pressure, which directly influence the operating state of the valve. That is, based on the detected values from the atmospheric pressure detection means and the intake pressure detection means,
The differential pressure determining means determines whether the differential pressure between the atmospheric pressure and the intake pressure exceeds the operating pressure of the exhaust recirculation control valve. If the differential pressure between atmospheric pressure and intake pressure exceeds the operating pressure of the exhaust recirculation control valve and exhaust recirculation is being performed,
Fuel injection is performed based on the previous injection command signal, and the air-fuel ratio is maintained near the stoichiometric air-fuel ratio.
一方、前記差圧が前記作動圧を下回り排気還流が実行さ
れていない場合には、空燃比の制御中心がリーン側にず
れるが、燃料噴射量補正手段により燃料噴射装置からの
燃料噴射量が増量される方向に噴射指令信号が補正され
て燃料噴射が実行されるため、かかる領域においても空
燃比は理論空燃比近傍に補正されることになる。On the other hand, when the differential pressure is lower than the operating pressure and exhaust gas recirculation is not performed, the control center of the air-fuel ratio shifts to the lean side, but the fuel injection amount correction means increases the amount of fuel injected from the fuel injection device. Since the injection command signal is corrected in the direction in which fuel injection is performed, the air-fuel ratio is corrected to be close to the stoichiometric air-fuel ratio even in this region.
［実施例］
以下、本発明の一実施例を第２図〜第４図を参照して説
明する。[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 2 to 4.
第２図は、自動車用エンジンを概略的に示したもので、
図面において１はエンジン本体を示し、２はエンジン本
体１の燃焼室３に連通ずる吸気通路、４は排気通路を示
している。吸気通路２のエアクリーナ側にはサージタン
ク５を介設している一方、燃焼室３側の吸気管６には燃
料噴射装置たるインジェクタ７を装着しである。そして
、このインジェクタ７を後述するマイクロコンピュータ
システム８により制御するようにしている。Figure 2 schematically shows an automobile engine.
In the drawings, 1 indicates an engine body, 2 an intake passage communicating with a combustion chamber 3 of the engine body 1, and 4 an exhaust passage. A surge tank 5 is interposed on the air cleaner side of the intake passage 2, while an injector 7, which is a fuel injection device, is installed in the intake pipe 6 on the combustion chamber 3 side. This injector 7 is controlled by a microcomputer system 8, which will be described later.
前記サージタンク５内と排気通路４内とを連通ずる排気
還流通路９には、大気圧Ｐ＾と吸気圧四との差圧により
作動する排気還流制御バルブ（以後、ＥＧＲバルブと称
する）１０を介設しである。ＥＧＲバルブ１０はエンジ
ンの運転状況に応じたバルブ開成により、排気通路４内
の排気ガスの一部を吸気道路２に介設した前記サージタ
ンク５内に導くためのもので、その負圧室１０ａとスロ
ットルバルブ付近のＥＧＲポート１１とを連通ずる負圧
通路１２を介して負圧室１０ａに吸気圧ＰＭが導入され
るようになっている。他方、この負圧室１０ａとダイヤ
フラムを隔てて設けられた定圧室１０ｂには、常時大気
圧ＰＡが導入されるようになっている。The exhaust gas recirculation passage 9 that communicates the inside of the surge tank 5 and the exhaust passage 4 is provided with an exhaust gas recirculation control valve (hereinafter referred to as an EGR valve) 10 that is operated by the differential pressure between the atmospheric pressure P^ and the intake pressure 4. There is no intervention. The EGR valve 10 is for guiding a part of the exhaust gas in the exhaust passage 4 into the surge tank 5 interposed in the intake road 2 by opening the valve according to the operating condition of the engine. Intake pressure PM is introduced into the negative pressure chamber 10a through a negative pressure passage 12 that communicates with the EGR port 11 near the throttle valve. On the other hand, atmospheric pressure PA is always introduced into a constant pressure chamber 10b provided across a diaphragm from the negative pressure chamber 10a.
そして、大気圧ＰＡと前記負圧室１０ａに導かれた吸気
圧ＰＭとの差圧がＥＧＩ？バルブ作動圧ＰＥＧＲＶ
（例えば１００ｍｍｌＩｇ）を上回るとＥＧＲバルブ１
ｏが開成し排気通路４内の排気ガスをサージタンク５内
に導入するように設定しである。また、前記負圧通路１
２でＥＧＩ？バルブ１ｏとサージタンク５との間には、
ＥＧＲモジュレータ１３を介設し、ＥＧＲバルブ１０下
流側の排気還流通路１２内の排気圧を利用して前記ＥＧ
Ｒバルブ１ｏの負圧室１０ａへ導入される吸気圧ＰＭが
調整されるようにしであるとともに、該ＥＧＩ？モジュ
レータ１３の上流側には、前記ＥＧＲバルブ１０の負圧
室１０ａに作用する吸気圧ＰＭをエンジン低負荷領域で
制限する電子式の負圧切換弁１４を介設しである。Then, the differential pressure between the atmospheric pressure PA and the intake pressure PM guided to the negative pressure chamber 10a is EGI? Valve operating pressure PEGRV
(for example, 100 mmlIg), EGR valve 1
o is opened and the exhaust gas in the exhaust passage 4 is introduced into the surge tank 5. Further, the negative pressure passage 1
EGI in 2? Between valve 1o and surge tank 5,
An EGR modulator 13 is provided to utilize the exhaust pressure in the exhaust gas recirculation passage 12 on the downstream side of the EGR valve 10 to
The intake pressure PM introduced into the negative pressure chamber 10a of the R valve 1o is adjusted, and the EGI? An electronic negative pressure switching valve 14 is provided upstream of the modulator 13 to limit the intake pressure PM acting on the negative pressure chamber 10a of the EGR valve 10 in a low engine load region.
また、前記サージタンク５側には、大気圧ＰＡを検出す
る大気圧検出手段および吸気圧ＰＭを検出する吸気圧検
出手段たる共通の圧力センサ１５が設けられている。圧
力センサ１５は切換弁１６を介して外気中とサージタン
ク６内とに選択的に接続し得るようになっている。具体
的には、切換弁１６は前記負圧切換弁１４と略同様なも
ので、バキュウムスイッチングタイプの三方切換弁であ
り、第１の入力ポート１６ａを前記サージタンク６内に
連通させるとともに、第２の入力ポート１６ｂをフィル
タを介して外気中に開放し、出力ポート１６ｃを前記圧
力センサ１５に接続している。そして、その電気入力端
子に通電が行われていない場合には、吸気圧ＰＡ側に保
持されて前記第１の入力ポート１６ａと出力ポート１６
ｃとが連通し、電気入力端子に通電がなされた場合には
、大気圧ＰＡ側に切換って前記第２の入力ポート１６ｂ
と出力ポート１６ｃとが連通ずるように構成されている
。Further, a common pressure sensor 15 is provided on the surge tank 5 side, which serves as an atmospheric pressure detection means for detecting atmospheric pressure PA and an intake pressure detection means for detecting intake pressure PM. The pressure sensor 15 can be selectively connected to the outside air and the inside of the surge tank 6 via a switching valve 16. Specifically, the switching valve 16 is substantially the same as the negative pressure switching valve 14, and is a vacuum switching type three-way switching valve, with the first input port 16a communicating with the inside of the surge tank 6, and the first input port 16a communicating with the inside of the surge tank 6. The second input port 16b is opened to the outside air through a filter, and the output port 16c is connected to the pressure sensor 15. When the electrical input terminal is not energized, it is held on the intake pressure PA side and the first input port 16a and output port 16
When the electrical input terminal is energized, the second input port 16b is switched to the atmospheric pressure PA side.
and the output port 16c are configured to communicate with each other.
一方、前記マイクロコンピュータシステム８は、各種セ
ンサ等からの情報をもとに、一定周期毎に燃料の基本噴
射量ＴＰＢＳＥを求めるとともに、この基本噴射量ＴＰ
ＢＳＥに基づいてエンジンの運転状況により決定された
各種の補正を行い、前記インジェクタ７から噴射される
燃料の最終噴射量ＴＰ （燃料噴射時間）を演算するよ
うに設定されている。On the other hand, the microcomputer system 8 calculates the basic injection amount TPBSE of fuel at regular intervals based on information from various sensors, etc., and calculates the basic injection amount TPBSE.
The final injection amount TP (fuel injection time) of the fuel injected from the injector 7 is calculated by performing various corrections determined based on the BSE based on the operating conditions of the engine.
そして、前記排気通路４に設けた０２センサ１７からの
情報に基づいて空燃比を理論空燃比近傍に維持する、い
わゆる０２フイードバツク制御の役割を担うとともに、
差圧判定手段１８と、燃料噴射量補正手段１９との役割
をも担っており、中央演算処理装置２０と、メモリ２１
と、入Φ出力インターフェース２２．２３とを備えてい
る。そして、前記入力インターフェース２２に少なくと
も前記０２センサ１７からの信号ａと、ディストリビュ
ータ２４に設けられた回転数センサ（図示せず）からの
信号すと、圧力センサ１５からの信号Ｃとが入力され、
前記出力インターフェース２３からは、インジェクタ７
と、負圧切換弁１４、および切換弁１６に向けて信号ｄ
、ｅ、ｆが出力されるようになっている。It plays the role of so-called 02 feedback control, which maintains the air-fuel ratio near the stoichiometric air-fuel ratio based on information from the 02 sensor 17 provided in the exhaust passage 4.
It also plays the roles of the differential pressure determination means 18 and the fuel injection amount correction means 19, and the central processing unit 20 and the memory 21.
and an input Φ output interface 22.23. Then, at least a signal a from the 02 sensor 17, a signal from a rotation speed sensor (not shown) provided in the distributor 24, and a signal C from the pressure sensor 15 are input to the input interface 22,
From the output interface 23, the injector 7
, a signal d is sent to the negative pressure switching valve 14 and the switching valve 16.
, e, and f are output.
前記差圧判定手段１８は、前記切換弁１６が外気側と吸
気側に選択的に切換制御されることにより、圧力センサ
１５がら得られる大気圧ＰＡと吸気圧ＰＭとの差圧が前
記ＥＧＲバルブ作動圧ＰＥＧＲＶ （１００ｍｍ１ｇ）
を上回っているが否がを判定するように設定されている
。The differential pressure determining means 18 is configured such that the switching valve 16 is selectively switched between the outside air side and the intake side, so that the differential pressure between the atmospheric pressure PA and the intake pressure PM obtained from the pressure sensor 15 is determined by the EGR valve. Working pressure PEGRV (100mm 1g)
It is set to determine whether or not the value exceeds the specified value.
一方、燃料噴射量補正手段２ｏは、前記差圧判定手段１
８による判定結果に基づいて、大気圧ＰＡと吸気圧ＰＭ
との差圧がＥＧＲバルブ作動圧ＰＥＧＲＶに達していな
いと判定された場合にのみ、インジェクタ７からの最終
噴射量ＴＰを増量する方向に前記ＥＧＲ補正値ＫＴＰＥ
ＧＲを補正する役目を担って・いる。On the other hand, the fuel injection amount correction means 2o includes the differential pressure determination means 1.
Based on the determination result of 8, atmospheric pressure PA and intake pressure PM
The EGR correction value KTPE is adjusted in the direction of increasing the final injection amount TP from the injector 7 only when it is determined that the differential pressure between the
It plays the role of correcting GR.
換言すれば、差圧判定手段１８の判定結果に基づき大気
圧ＰＡと吸気圧ＰＭとの差圧がＥＧＲバルブ作動圧ＰＥ
ＧＲＶを上回っている場合には、従前の燃料供給量を以
て燃料噴射が実行されるように設定しである。すなわち
、この場合は、回転数センサや圧力センサ１４等からの
情報により決定された基本噴射量ＴＰＢＳＥにＥＧＲ実
台中台中常のＥＧＲ補正値ＫＴｐＥｃＲ等を乗じた値に
、さらに電圧補正分等の無効噴射時間ＴＡυＶが付加さ
れて空燃比が理論空燃比近傍に維持されるように前記イ
ンジェクタ７からの最終噴射量ＴＰが演算される。一方
、大気圧ＰＡと吸気圧ＰＭとの差圧がＥＧＲバルブ作動
圧ＰＥＧＲＶを下回っている場合には、空燃比の制御中
心が理論空燃比となるように基本噴射量ＴＰＢＳＢに乗
じるＥＧＲ補正値ＫＴＰＥＧＲを例えば１．１０倍し、
インジェクタ７からの最終噴射量ＴＰを増量させるよう
に設定されている。In other words, based on the determination result of the differential pressure determining means 18, the differential pressure between the atmospheric pressure PA and the intake pressure PM is equal to the EGR valve operating pressure PE.
If it exceeds GRV, the setting is such that fuel injection is performed using the previous fuel supply amount. That is, in this case, the value obtained by multiplying the basic injection amount TPBSE determined based on the information from the rotation speed sensor, pressure sensor 14, etc. by the EGR actual correction value KTpEcR, etc., plus the invalid voltage correction value, etc. The final injection amount TP from the injector 7 is calculated so that the injection time TAυV is added and the air-fuel ratio is maintained near the stoichiometric air-fuel ratio. On the other hand, when the differential pressure between the atmospheric pressure PA and the intake pressure PM is lower than the EGR valve operating pressure PEGRV, the EGR correction value KTPEG is multiplied by the basic injection amount TPBSB so that the control center of the air-fuel ratio becomes the stoichiometric air-fuel ratio. For example, multiply by 1.10,
It is set to increase the final injection amount TP from the injector 7.
そして、上記マイクロコンピュータシステム８には、以
上のような制御を行うために、第４図に示すようなプロ
グラムも内蔵させである。まず、ステップ５１で切換弁
１６を切換えた後の圧力センサ１５からの大気圧ＰＡを
取込みステップ５２へ進む。ステップ５２では同様に圧
力センサ１５によるサージタンク５内の吸気圧ＰＭを取
込み、ステップ５３へ進む。ステップ５３では回転数セ
ンサからのエンジン回転数と吸気圧ＰＭ等から基本噴射
量ＴＰＢＳＥを演算しステップ５４へ進む。ステップ５
４ではＥＧＲ補正実行フラグＦＬＡＧが１か否かを判定
し、ＥＧＲ補正実行フラグＦＬＡＧが１であればステッ
プ５５へ進み、１でなければステップ５６へ進む。ステ
ップ５６では大気圧ＰＡとＥＧＲバルブ作動圧ＰＥＧＲ
Ｖとの差圧を比較ＣＭＰにセットしてステップ５７へ進
む。ステップ５５では大気圧ＰＡとＥＧＲバルブ作動圧
ＰＥＧＲＶおよびヒステリシス旧Ｓ （例えば３０ｍｍ
Ｈｇ）との差圧をＥＧＲ補正判定値ＣＭＰとしてセット
しステップ５７へ進む。ステップ５７では前記吸気圧Ｐ
ＭがＥＧＲ補正判定値ＣＭＰ以上か否かを判定し、未満
であると判定した場合は、ＥＧＲバルブ１０が作動しＥ
ＧＲ実行中として、ステップ５８へ進み、吸気圧ＰＭが
ＥＣＲ補正判定値ＣＭＰ以上であると判定した場合は、
排気還流が実行されていないと判定しステップ６０へ進
む。ステップ５８では、ＥＧＲ補正判定フラグＦＬＡＧ
をクリア（０をセット）してステップ５つへ進む。ステ
ップ５９では、エンジン回転数や吸気圧ＰＭ等により決
定された基本噴射量ＴＰＢＳＥをもとに、最終噴射量Ｔ
Ｐを演算する。ステップ６０ではＥＧＲ補正判定フラグ
ＦＬＡＧに１をセットしてステップ６１へ進む。ステッ
プ６１では基本噴射量ＴＰＢＳＥに、１．１０倍したＥ
ＧＲ補正値ＫＴＰＥＧＲを乗じた値等をもとに最終噴射
量ＴＰを演算する。The microcomputer system 8 also has a built-in program as shown in FIG. 4 in order to perform the above-described control. First, in step 51, the atmospheric pressure PA from the pressure sensor 15 after switching the switching valve 16 is taken in, and the process proceeds to step 52. In step 52, the intake pressure PM in the surge tank 5 is similarly detected by the pressure sensor 15, and the process proceeds to step 53. In step 53, the basic injection amount TPBSE is calculated from the engine rotational speed from the rotational speed sensor, intake pressure PM, etc., and the process proceeds to step 54. Step 5
In step 4, it is determined whether the EGR correction execution flag FLAG is 1 or not. If the EGR correction execution flag FLAG is 1, the process proceeds to step 55, and if it is not 1, the process proceeds to step 56. In step 56, atmospheric pressure PA and EGR valve operating pressure PEG
The differential pressure with respect to V is set in the comparison CMP, and the process proceeds to step 57. In step 55, atmospheric pressure PA, EGR valve operating pressure PEGRV and hysteresis old S (for example, 30mm
Hg) is set as the EGR correction determination value CMP, and the process proceeds to step 57. In step 57, the intake pressure P
It is determined whether or not M is greater than or equal to the EGR correction judgment value CMP, and if it is determined that it is less than that, the EGR valve 10 is activated and the EGR valve 10 is activated.
If it is determined that GR is being executed and the process proceeds to step 58, and it is determined that the intake pressure PM is equal to or higher than the ECR correction determination value CMP,
It is determined that exhaust gas recirculation is not being performed, and the process proceeds to step 60. In step 58, the EGR correction determination flag FLAG
Clear (set to 0) and proceed to step 5. In step 59, the final injection amount TPBSE is determined based on the engine speed, intake pressure PM, etc.
Calculate P. In step 60, the EGR correction determination flag FLAG is set to 1, and the process proceeds to step 61. In step 61, the basic injection amount TPBSE is multiplied by 1.10.
The final injection amount TP is calculated based on the value multiplied by the GR correction value KTPEGR.
しかして、このような構成によると、０２フイードバツ
ク制御中においては、切換弁１６の切換制御により得ら
れる圧力センサ１５からの検出値をもとに、ＥＧＲバル
ブ１０が作動しているか否か、換言すれば、排気ガスの
一部が吸気中に還流されているか否かが判定される。す
なわち、大気圧ＰＡと吸気圧ＰＭとの差圧がＥＧＲバル
ブ作動圧ＰＥＧＲ以上であれば、ＥＧＲバルブ１０が作
動し、排気還流が実行されていることになる。その場合
は、回転数センサや圧力センサ１５等からの情報をもと
に算出された基本噴射量ＴＰＢＳＨに、ＥＧＲ実行中の
空燃比が理論空燃比となる通常のＥＧＲ補正値ＫＴＰＥ
ＧＲが乗されることになる。According to such a configuration, during the 02 feedback control, it is determined whether the EGR valve 10 is operating or not based on the detected value from the pressure sensor 15 obtained by the switching control of the switching valve 16. Then, it is determined whether part of the exhaust gas is recirculated into the intake air. That is, if the differential pressure between the atmospheric pressure PA and the intake pressure PM is equal to or higher than the EGR valve operating pressure PEGR, the EGR valve 10 is operated and exhaust gas recirculation is being performed. In that case, a normal EGR correction value KTPE is added to the basic injection amount TPBSH calculated based on information from the rotation speed sensor, pressure sensor 15, etc., so that the air-fuel ratio during EGR execution becomes the stoichiometric air-fuel ratio.
GR will be multiplied.
一方、大気圧ＰＡと吸気圧ＰＭとの差圧がＥＧＲバルブ
作動圧ＰＥＧＲＶ未満であれば、ＥＧＲバルブ１０が作
動せず、排気還流が行われていないことになる。On the other hand, if the differential pressure between the atmospheric pressure PA and the intake pressure PM is less than the EGR valve operating pressure PEGRV, the EGR valve 10 does not operate and exhaust gas recirculation is not performed.
その場合は、ＥＧＲ実行時のＥＧＲ補正係数が１．１０
倍されるるとともに、この値ＫＴＰＥＧＲ等と前記同様
に算出された基本噴射量ＴＰＢＳＥをもとに空燃比が理
論空燃比となる最終噴射量ＴＰが演算されることになる
。In that case, the EGR correction coefficient during EGR execution is 1.10.
In addition, the final injection amount TP at which the air-fuel ratio becomes the stoichiometric air-fuel ratio is calculated based on this value KTPEGR and the like and the basic injection amount TPBSE calculated in the same manner as described above.
したがって、このような構成であれば、圧力センサ１５
からの情報をもとにＥＧＲ実行中か否かを確実に判定す
ることができるとともに、ＥＧＲを実行していない領域
でのインジェクタ７からの最終噴射量ＴＰが理論空燃比
近傍となるように補正される。その結果、０２フイード
バツクの制御下では、ＥＧＲ実行領域においても、空燃
比が理論空燃比近傍に維持されて運転性が損なわれるよ
うなことがない上に、排気ガス中の有害成分の除去効率
が低下するような不具合も防止される。また、圧力セン
サ１５により検出される大気圧ＰＡと吸気圧ＰＭとの差
圧による補正は相対的なものであるから、大気圧が変化
しても有効である。Therefore, with such a configuration, the pressure sensor 15
It is possible to reliably determine whether or not EGR is being executed based on information from be done. As a result, under the control of 02 feedback, the air-fuel ratio is maintained close to the stoichiometric air-fuel ratio even in the EGR execution region, and drivability is not impaired, and the removal efficiency of harmful components in the exhaust gas is improved. Problems such as deterioration are also prevented. Furthermore, since the correction based on the differential pressure between the atmospheric pressure PA and the intake pressure PM detected by the pressure sensor 15 is relative, it is effective even if the atmospheric pressure changes.
そして、本実施例では、通常、設置される圧力センサ１
５に切換弁１６を付設し、圧力センサ１５の圧力検出領
域を大気側と吸気側とに切換制御し得るようにしている
ため、格別な圧力センサを設けるようなこともなく、好
都合である。In this embodiment, the pressure sensor 1 that is normally installed is
5 is provided with a switching valve 16 so that the pressure detection area of the pressure sensor 15 can be switched between the atmospheric side and the intake side, which is advantageous since there is no need to provide a special pressure sensor.
なお、本発明は、上記実施例に限定されるものではなく
、例えば、大気圧検出手段と吸気圧検出手段とを各別に
設けるようにしてもよく、あるいは、ＥＧＲ実行領域外
でのＥＧＲ補正係数を排気ガスの還流量に応じて設定す
るようにしてもよい。Note that the present invention is not limited to the above-mentioned embodiments, and for example, the atmospheric pressure detection means and the intake pressure detection means may be provided separately, or the EGR correction coefficient outside the EGR execution area may be may be set depending on the amount of exhaust gas recirculation.
［発明の効果］
以上、詳述したように本発明では、排気還流制御バルブ
の作動を左右する大気圧と吸気圧とを直接検出し、排気
還流制御バルブの作動状態を確実に判別することにより
、排気還流の実行領域外においても空燃比を理論空燃比
近傍に維持することができる。その結果、排気還流が実
行されていない領域においても、運転性が損われるよう
なことがない上に、排気ガス中の有害成分の除去効率を
悪化させるようなことのない空燃比制御装置を提供する
ことができる。[Effects of the Invention] As described above in detail, the present invention directly detects the atmospheric pressure and intake pressure that affect the operation of the exhaust recirculation control valve, and reliably determines the operating state of the exhaust recirculation control valve. , the air-fuel ratio can be maintained near the stoichiometric air-fuel ratio even outside the exhaust gas recirculation execution range. As a result, we provide an air-fuel ratio control device that does not impair drivability even in areas where exhaust gas recirculation is not performed, and does not deteriorate the removal efficiency of harmful components in exhaust gas. can do.
−１５＝−15=
第１図は本発明を明示するための構成説明図、第２図は
本発明の一実施例を示すシステム説明図、第３図は同実
施例の制御設定条件を示す図、第４図は同実施例の制御
手順を示すフローチャート図である。
１・・・エンジン本体
２・・・吸気通路
４・・・排気通路
５・・・サージタンク
７・・・燃料噴射装置（インジェクタ）８・・・マイク
ロコンピュータシステム９・・・ＥＧＲ通路
１０・・・ＥＧＲバルブ
１５・・・大気圧検出手段（圧力センサ）１５・・・吸
気圧検出手段（圧力センサ）１８・・・差圧判定手段
１つ・・・燃料噴射量補正手段Fig. 1 is an explanatory diagram of the configuration to clarify the present invention, Fig. 2 is an explanatory diagram of a system showing an embodiment of the invention, Fig. 3 is a diagram showing control setting conditions of the embodiment, and Fig. 4 is an explanatory diagram of the system. It is a flowchart figure which shows the control procedure of the same Example. 1... Engine body 2... Intake passage 4... Exhaust passage 5... Surge tank 7... Fuel injection device (injector) 8... Microcomputer system 9... EGR passage 10... - EGR valve 15...Atmospheric pressure detection means (pressure sensor) 15...Intake pressure detection means (pressure sensor) 18...One differential pressure determination means...Fuel injection amount correction means
Claims (1)
ルブと、噴射指令信号に対応する量の燃料を吸気系に噴
射する燃料噴射装置とを具備してなる内燃機関において
、大気圧を検出する大気圧検出手段と、吸気圧を検出す
る吸気圧検出手段と、前記両検出手段による検出値に基
いて大気圧と吸気圧との差圧が前記排気還流制御バルブ
の作動圧を上回ったか否かを判定する差圧判定手段と、
この差圧判定手段により前記差圧が前記作動圧を下回っ
ていると判定された場合にのみ前記燃料噴射装置からの
燃料噴射量を増量する方向に前記噴射指令信号を補正す
る燃料噴射量補正手段とを設けてなることを特徴とする
内燃機関の空燃比制御装置。Detects atmospheric pressure in an internal combustion engine equipped with an exhaust recirculation control valve that operates based on the differential pressure between atmospheric pressure and intake pressure, and a fuel injection device that injects fuel into the intake system in an amount corresponding to an injection command signal. an atmospheric pressure detection means for detecting the intake pressure, an intake pressure detection means for detecting the intake pressure, and whether or not the differential pressure between the atmospheric pressure and the intake pressure exceeds the operating pressure of the exhaust recirculation control valve based on the detected values by both the detection means. differential pressure determination means for determining whether
Fuel injection amount correction means for correcting the injection command signal in the direction of increasing the fuel injection amount from the fuel injection device only when the differential pressure is determined to be lower than the operating pressure by the differential pressure determination means. An air-fuel ratio control device for an internal combustion engine, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25408886A JPS63109250A (en) | 1986-10-25 | 1986-10-25 | Air-fuel ratio control device for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25408886A JPS63109250A (en) | 1986-10-25 | 1986-10-25 | Air-fuel ratio control device for internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63109250A true JPS63109250A (en) | 1988-05-13 |
Family
ID=17260058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25408886A Pending JPS63109250A (en) | 1986-10-25 | 1986-10-25 | Air-fuel ratio control device for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63109250A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02211340A (en) * | 1989-02-08 | 1990-08-22 | Daihatsu Motor Co Ltd | Correction for fuel quantity in internal combustion engine |
| CN106662031A (en) * | 2014-08-01 | 2017-05-10 | 丰田自动车株式会社 | Control system for an internal combustion engine |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5882037A (en) * | 1981-11-11 | 1983-05-17 | Honda Motor Co Ltd | Electronic fuel supply controller having exhaust gas recirculation control function of internal-combustion engine |
| JPS5888429A (en) * | 1981-11-19 | 1983-05-26 | Honda Motor Co Ltd | Electronic fuel injection controller of internal- combustion engine equipped with exhaust gas recirculation controller |
-
1986
- 1986-10-25 JP JP25408886A patent/JPS63109250A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5882037A (en) * | 1981-11-11 | 1983-05-17 | Honda Motor Co Ltd | Electronic fuel supply controller having exhaust gas recirculation control function of internal-combustion engine |
| JPS5888429A (en) * | 1981-11-19 | 1983-05-26 | Honda Motor Co Ltd | Electronic fuel injection controller of internal- combustion engine equipped with exhaust gas recirculation controller |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02211340A (en) * | 1989-02-08 | 1990-08-22 | Daihatsu Motor Co Ltd | Correction for fuel quantity in internal combustion engine |
| CN106662031A (en) * | 2014-08-01 | 2017-05-10 | 丰田自动车株式会社 | Control system for an internal combustion engine |
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