JPS61101636A - Method of controlling fuel supply to internal-combustion engine at the time of its deceleration - Google Patents
Method of controlling fuel supply to internal-combustion engine at the time of its decelerationInfo
- Publication number
- JPS61101636A JPS61101636A JP22116484A JP22116484A JPS61101636A JP S61101636 A JPS61101636 A JP S61101636A JP 22116484 A JP22116484 A JP 22116484A JP 22116484 A JP22116484 A JP 22116484A JP S61101636 A JPS61101636 A JP S61101636A
- Authority
- JP
- Japan
- Prior art keywords
- engine
- value
- air
- combustion engine
- internal combustion
- 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.)
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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
- F02D41/1486—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor with correction for particular operating conditions
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- 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)
Abstract
Description
【発明の詳細な説明】
(技術分野)
本発明は内燃エンジンの燃料供給制御方法に関し、特に
エンジンのフィードバック制御運転中の減速時における
排気ガス特性の向上を図った燃料供給制御方法に関する
。TECHNICAL FIELD The present invention relates to a fuel supply control method for an internal combustion engine, and more particularly to a fuel supply control method for improving exhaust gas characteristics during deceleration during feedback control operation of the engine.
(発明の技術的背景とその問題点)
内燃エンジンの排気ガス中の有害成分、例えば−酸化炭
素(C○)や未燃炭化水素(UHC)を減少させるため
に排気通路に三元触媒等の排気浄化装置を配設し、排気
ガス中の排気ガス成分、例えば酸素の濃度を酸素濃度検
出器(以下「02セサン」という)により検出し、この
0□センサが出力する02濃度検出値信号に基づいてエ
ンジンに供給される混合気の空燃比を所定空燃比、例え
ば理論空燃比にフィードバック制御(以下「02フイー
ドバツク制御」という)する燃料供給制御方法が従来よ
り知られている。斯かる0□フイードバツク制御中に上
述の排気浄化装置の浄化率を最適値に維持するには空燃
比を前記所定空燃比に正確に制御することが肝要である
が、エンジンの減速時には、スロットル弁が閉弁される
ため、スロットル弁下流側の吸気管内の圧力が低下し、
吸気管の内壁に付着していた燃料が燃焼室内に供給され
る場合が生じる。この結果、o2フィードバック制御運
転状態における減速時には燃焼室内に供給される混合気
がオーバーリッチ化し、o2フィードバック制御を行っ
ても未燃排気ガス成分として排出されるCo及びUHC
の排出量を十分に低減させることが出来なかった。特に
、高エンジン回転運転状態からの減速時にはCo、UH
Cの排出量が多くなる傾向が強かった。(Technical background of the invention and its problems) In order to reduce harmful components such as carbon oxide (CO) and unburned hydrocarbons (UHC) in the exhaust gas of internal combustion engines, a three-way catalyst or the like is installed in the exhaust passage. An exhaust purification device is installed, and an oxygen concentration detector (hereinafter referred to as "02 sesan") detects the concentration of exhaust gas components in the exhaust gas, such as oxygen, and the 02 concentration detection value signal output from this 0□ sensor is used. A fuel supply control method is conventionally known in which the air-fuel ratio of the air-fuel mixture supplied to the engine is feedback-controlled (hereinafter referred to as "02 feedback control") to a predetermined air-fuel ratio, for example, the stoichiometric air-fuel ratio. In order to maintain the purification rate of the exhaust gas purification device at the optimum value during such 0□ feedback control, it is important to accurately control the air-fuel ratio to the predetermined air-fuel ratio. is closed, the pressure in the intake pipe downstream of the throttle valve decreases,
Fuel adhering to the inner wall of the intake pipe may be supplied into the combustion chamber. As a result, during deceleration in the O2 feedback control operating state, the air-fuel mixture supplied into the combustion chamber becomes overrich, and even if O2 feedback control is performed, Co and UHC are emitted as unburned exhaust gas components.
It was not possible to sufficiently reduce the amount of emissions. Especially when decelerating from a high engine speed operating state, Co, UH
There was a strong tendency for the amount of C emissions to increase.
(発明の目的)
本発明は斯かる問題点を解決するためになされたもので
、減速時におけるエンジンの排気ガス特性の向上を図っ
た燃料供給制御方法を提供することを目的とする。(Objective of the Invention) The present invention was made to solve the above problems, and an object of the present invention is to provide a fuel supply control method that improves the exhaust gas characteristics of an engine during deceleration.
(発明の構成)
斯かる目的のために、本発明に依れば、内燃エンジンの
排気通路に配設された排気ガス成分濃度検出手段からの
検出値信号に基づいて該内燃エンジンに供給する混合気
の空燃比をフィードバック制御する燃料供給制御方法に
おいて、エンジン回転数を検出し、前記内燃エンジンが
減速運転状態にあるか否かを検出し、前記内燃エンジン
が減速運転状態にあり、且つ、エンジン回転数検出値が
第1の所定エンジン回転数値より大きい値から該第1の
所定エンジン回転数値より小さい第2の所定エンジン回
転数値迄減少する間に亘って、前記排気ガス成分濃度検
出手段からの検出値に応じて前記内燃エンジンに供給す
る混合気の空燃比をリーン化することを特徴とする内燃
エンジンの減速時燃料供給制御方法が提供される。(Structure of the Invention) For this purpose, according to the present invention, a mixture is supplied to the internal combustion engine based on a detected value signal from the exhaust gas component concentration detection means disposed in the exhaust passage of the internal combustion engine. In a fuel supply control method that performs feedback control of an air-fuel ratio of air, the engine rotation speed is detected to determine whether or not the internal combustion engine is in a decelerated operating state, and the internal combustion engine is in a decelerated operating state and the engine is in a decelerated operating state. During the period when the detected engine speed value decreases from a value larger than the first predetermined engine speed value to a second predetermined engine speed value smaller than the first predetermined engine speed value, the exhaust gas component concentration detection means There is provided a fuel supply control method during deceleration of an internal combustion engine, characterized in that the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine is made lean in accordance with a detected value.
(発明の実施例) 以下本発明の実施例を図面を参照して説明する。(Example of the invention) Embodiments of the present invention will be described below with reference to the drawings.
第1図は本発明の方法を適用した燃料供給制御装置の全
体構成図であり、符号1は例えば4気筒の内燃エンジン
を示し、エンジン1には吸気管2が接続されている。吸
気管2の途中にはスロットルボディ3が設けられ、内部
にスロットル弁3′が設けられている。スロットル弁3
′にはスロットル弁開度(θth)センサ4が連設され
てスロットル弁3′の弁開度を電気的信号に変換し電子
コントロールユニット(以下「ECU」といつ)5に送
るようにされている。FIG. 1 is an overall configuration diagram of a fuel supply control device to which the method of the present invention is applied. Reference numeral 1 indicates, for example, a four-cylinder internal combustion engine, and an intake pipe 2 is connected to the engine 1. A throttle body 3 is provided in the middle of the intake pipe 2, and a throttle valve 3' is provided inside. Throttle valve 3
A throttle valve opening (θth) sensor 4 is connected to ', which converts the valve opening of the throttle valve 3' into an electrical signal and sends it to an electronic control unit (hereinafter referred to as "ECU") 5. There is.
吸気管2のエンジン1及びスロットルボディ3間には各
気筒毎に、各気筒の吸気弁(図示せず)の少し上流に夫
々燃料噴射弁6が設けられている。A fuel injection valve 6 is provided in the intake pipe 2 between the engine 1 and the throttle body 3 for each cylinder, slightly upstream of the intake valve (not shown) of each cylinder.
燃料噴射弁6は図示しない燃料ポンプに接続されている
と共にECU3に電気的に接続されており、EC:U5
からの信号によって燃料噴射弁6の開弁時間が制御され
る。The fuel injection valve 6 is connected to a fuel pump (not shown) and is electrically connected to the ECU 3, EC: U5.
The valve opening time of the fuel injection valve 6 is controlled by a signal from the fuel injection valve 6.
一方、前記スロットルボディ3のスロットル弁3′の下
流には管7を介して絶対圧CPBA)センサ8が設けら
れており、この絶対圧センサ8によって電気的信号に変
換された絶対圧信号は前記ECU3に送られる。On the other hand, an absolute pressure (CPBA) sensor 8 is provided downstream of the throttle valve 3' of the throttle body 3 via a pipe 7, and the absolute pressure signal converted into an electrical signal by the absolute pressure sensor 8 is transmitted to the Sent to ECU3.
エンジン1本体にはエンジン冷却水温センサ(以下rT
wセンサ」という)9が設けられ、Twセンサ9はサー
ミスタ等からなり、冷却水が充満したエンジン気筒周壁
内に装着されて、その検出水温信号をECU3に供給す
る。エンジン回転数センサ(以下rNeセンサ」という
)10がエンジンの図示しないカム軸周囲又はクランク
軸周囲に取り付けられており、Neセンサ10はエンジ
ンのクランク軸180°回転毎に所定のクランク角度位
置で、即ち、各気筒の吸気行程開始時の上死点(T D
C)に関し所定クランク角度前のクランク角度位置で
クランク角度位置信号(以下これをrTDc信号」とい
う)を出力するものであり、このTDC信号はECU3
に送られる。The engine cooling water temperature sensor (rT) is installed on the engine 1 body.
Tw sensor 9 (referred to as "W sensor") 9 is provided, and Tw sensor 9 is made of a thermistor or the like, and is installed in the circumferential wall of the engine cylinder filled with cooling water, and supplies its detected water temperature signal to ECU 3. An engine rotation speed sensor (hereinafter referred to as "rNe sensor") 10 is attached around the camshaft or crankshaft (not shown) of the engine, and the Ne sensor 10 is mounted at a predetermined crank angle position every 180° rotation of the engine crankshaft. In other words, the top dead center (T D
Regarding C), a crank angle position signal (hereinafter referred to as "rTDc signal") is output at a crank angle position before a predetermined crank angle, and this TDC signal is sent to the ECU 3.
sent to.
エンジン1の排気管11には三元触媒12が配置され排
気ガス中のU HC、G O、N Ox成分の浄化作用
を行う。この三元触媒12の上流側には02センサ13
が排気管11に挿着され、このセンサ13は排気中の酸
素濃度を検出し、02濃度信号をECU3に供給する。A three-way catalyst 12 is disposed in the exhaust pipe 11 of the engine 1 to purify U HC, G O, and NOx components in the exhaust gas. On the upstream side of this three-way catalyst 12 is an 02 sensor 13.
is inserted into the exhaust pipe 11, and this sensor 13 detects the oxygen concentration in the exhaust gas and supplies a 02 concentration signal to the ECU 3.
更に、ECU3には例えば大気圧センサ等の他のパラメ
ータセンサ14が接続されており、他のパラメータセン
サ14はその検出値信号をECU3に供給する。Furthermore, other parameter sensors 14 such as an atmospheric pressure sensor are connected to the ECU 3, and the other parameter sensors 14 supply their detected value signals to the ECU 3.
ECU3は各種センサからの入力信号波形を整形し、電
圧レベルを所定レベルに修正し、アナログ信号値をデジ
タル信号値に変換する等の機能を有する入力回路5a、
中央演算処理回路(以下rCPUJという)5b、CP
U5bで実行される各種演算プログラム及び演算結果等
を記憶する記憶手段5c、及び前記燃料噴射弁6に駆動
信号を供給する出力回路5d等から構成される。The ECU 3 includes an input circuit 5a having functions such as shaping input signal waveforms from various sensors, correcting voltage levels to predetermined levels, and converting analog signal values into digital signal values.
Central processing circuit (hereinafter referred to as rCPUJ) 5b, CP
It is composed of a storage means 5c for storing various calculation programs and calculation results executed by the U5b, an output circuit 5d for supplying a drive signal to the fuel injection valve 6, and the like.
CPU5bは入力回路5aを介して供給された前述の各
種センサからのエンジンパラメータ信号に基づいて5次
式で与えられる燃料噴射弁6の燃料噴射時間TOuTを
算出する。The CPU 5b calculates the fuel injection time TOuT of the fuel injection valve 6 given by a quintic equation based on engine parameter signals from the various sensors described above supplied via the input circuit 5a.
ToUT=TiXK+t+LXKo2XKLsXKt+
に2・・・(1)
ここに、T1は燃料噴射弁6の基本燃料噴射時間を示し
この基本噴射時間は例えば吸気管内絶対圧PBAとエン
ジン回転数Neとに基づいてECUS内の記憶手段5c
から読み出される。KIDシは本発明に係る減速補正係
数であり、その値は後述するKIDLID用−チンによ
り設定される。ToUT=TiXK+t+LXKo2XKLsXKt+
2...(1) Here, T1 indicates the basic fuel injection time of the fuel injection valve 6, and this basic injection time is stored in the storage means 5c in the ECUS based on, for example, the intake pipe absolute pressure PBA and the engine rotation speed Ne.
is read from. KID is a deceleration correction coefficient according to the present invention, and its value is set by the KIDLID function described later.
Ko、は02フイードバツク補正係数であり、その値は
後述するKo2フィードバック補正係数であ・す、その
値は後述するKo2サブルーチンにより設定される。K
L5はリーン化補正係数であり。Ko, is a 02 feedback correction coefficient, and its value is a Ko2 feedback correction coefficient, which will be described later, and is set by the Ko2 subroutine, which will be described later. K
L5 is a lean correction coefficient.
エンジンが、後述する第2図の領域Iに示す、エンジン
に掛かる負荷が低いリーン化運転領域にあるとき、混合
気をリーン化するために設定される補正係数である。K
1及びに2は夫々各種エンジンパラメータ信号に応じて
演算される補正係数及び補正変数であり、エンジン運転
状態に応じて燃費特性、排気ガス特性等の諸特性の最適
化が図られるような所要値に設定される。This is a correction coefficient that is set to lean the air-fuel mixture when the engine is in a lean operation region where the load on the engine is low, as shown in region I in FIG. 2, which will be described later. K
1 and 2 are correction coefficients and correction variables that are respectively calculated according to various engine parameter signals, and are required values to optimize various characteristics such as fuel consumption characteristics and exhaust gas characteristics according to engine operating conditions. is set to
CPU5bは上述のようにして求めた燃料噴射時間To
uTに基づいて燃料噴射弁6を開弁させる駆動信号を出
力回路5dを介して燃料噴射弁6に供給する。The CPU 5b calculates the fuel injection time To obtained as described above.
A drive signal for opening the fuel injection valve 6 based on uT is supplied to the fuel injection valve 6 via the output circuit 5d.
第3図は第1図のCPUSb内で実行される02フイー
ドバツク補正係数値KO2を設定するためのKO□サブ
ルーチンのフローチャートを示す。FIG. 3 shows a flowchart of the KO□ subroutine for setting the 02 feedback correction coefficient value KO2, which is executed in the CPUUSb of FIG.
先ず、ステップ301では第1図の02センサ13の活
性化が完了したか否かを判別する。02センサの活性化
判別方式としては、例えば0□センサに所要の電流を流
し、02センサの出力電圧が基準電圧を横切って下降し
たときに活性化が完了したと診断する内部抵抗検知方式
が知られている。そして、活性化が完了していれば(ス
テップ301での判別結果が肯定(Yes))、ステッ
プ302に進む。First, in step 301, it is determined whether activation of the 02 sensor 13 in FIG. 1 has been completed. As a method for determining the activation of the 02 sensor, for example, there is an internal resistance detection method that allows a required current to flow through the 0□ sensor and diagnoses that activation has been completed when the output voltage of the 02 sensor drops across the reference voltage. It is being If the activation has been completed (the determination result in step 301 is affirmative (Yes)), the process proceeds to step 302.
ステップ302ではエンジン水温値Twが所定判別水温
値TWO2(例えば70℃)より大きいか否かを判別す
る。エンジン温度が所定判別水温値T w o 、より
低くなると、気筒に供給された燃料の一部が気筒の内壁
に付着したり、燃料の気化が不十分になる等の理由で混
合気がリーン化し、エンジン運転が不安定になり易い。In step 302, it is determined whether the engine water temperature value Tw is larger than a predetermined determination water temperature value TWO2 (for example, 70° C.). When the engine temperature becomes lower than the predetermined determination water temperature value T w o , the mixture becomes lean due to reasons such as some of the fuel supplied to the cylinders adhering to the inner walls of the cylinders or insufficient vaporization of the fuel. , engine operation tends to become unstable.
このため燃料供給量を増量して混合気をリッチ化してい
る。この燃料増量時、即ち混合気のリッチ化時には02
フイードバツク制御を停止させるためにエンジン水温に
より、エンジンが燃料増量すべき運転状態にあるか否か
を判別するのである。エンジン水温値Twが所定判別水
温値Two□より大きければ燃料増量を行う必要がない
と判断し、ステップ303に進む。For this reason, the amount of fuel supplied is increased to enrich the air-fuel mixture. When increasing the amount of fuel, that is, enriching the mixture, 02
In order to stop the feedback control, it is determined based on the engine water temperature whether or not the engine is in an operating state that requires an increase in the amount of fuel. If the engine water temperature value Tw is larger than the predetermined determination water temperature value Two□, it is determined that there is no need to increase the amount of fuel, and the process proceeds to step 303.
一方、前記ステップ301及び302の内の少。On the other hand, only a few of the steps 301 and 302 are performed.
なくともいずれか一方が否定(No)の場合、エンジン
が0.フィードバック制御を停止すべき運転状態にある
と判断してステップ305に進み。If at least one of them is negative (No), the engine is 0. It is determined that the operation state is such that feedback control should be stopped, and the process proceeds to step 305.
後述するオープンループ制御を行う。Performs open loop control, which will be described later.
ステップ303ではエンジンが02フイードバツク運転
領域にあるか否かを判別する。0□フイードバツク運転
領域は第2図に斜線を付された領域(Hの一部及び■)
として示されている。エンジンが02フイードバツク運
転領域にあれば、02センサ13からの02a度検出値
信号に応じて○2フィードバック補正係数Ko2を算出
すると共に、後述するプログラムにより本発明に係る減
速補正係数に1DLを算出し、これらの算出したKo、
値及びKIDL値に応じて混合気の空燃比をフィードバ
ック制御する。In step 303, it is determined whether the engine is in the 02 feedback operation region. 0□Feedback operation area is the shaded area in Figure 2 (part of H and ■)
It is shown as. If the engine is in the 02 feedback operation region, the ○2 feedback correction coefficient Ko2 is calculated according to the 02a degree detection value signal from the 02 sensor 13, and 1DL is calculated as the deceleration correction coefficient according to the present invention by the program described later. , these calculated Ko,
The air-fuel ratio of the air-fuel mixture is feedback-controlled according to the value and the KIDL value.
ステップ303での判別結果が否定(No)の場合、即
ちエンジンがオープンループ制御運転領域にあるときに
はo2フィードバック制御を解除し、補正係数Ko2を
値1.0に設定しくステップ305)、本プログラムを
終了する。オープンループ制御運転領域は例えば第2図
に示す領域■(リーン化運転領域)、領域■(アイドル
運転領域)の一部(斜線を付されていない領域)、領域
■(低回転運転領域)、領域■(高負荷運転領域)及び
領域■(高回転運転領域)が含まれる。リーン化運転領
域■はエンジン減速時に吸気管内絶対圧PBAがエンジ
ン回転数Neの増加と共に大きい値に設定される判別値
P e ALJ以下の領域、アイドル運転領域■はエン
ジン回転数Neが判別値NIDL(例えば1000 p
p m )より低く且つ吸気管内絶対圧PBAが判別
値P BAIDL (例えば360mmt1g)より低
い領域、低回転運転領域■はエンジン回転数Neが判別
値NLOP(例えば600rpm)以下で且つ吸気管内
絶対圧PBAが判別値PBAIDL(例えば360mm
Hg)とエンジン回転数Neに応じて設定される高負荷
領域判別値θWOTとの間にある領域、高負荷運転領域
■は高負荷時にスロットル弁開度θthが前記判別値θ
WOT以上の領域、高回転運転領域■はエンジン回転数
Neが判別値NHOP (例えば3000ppm)以上
の領域である。If the determination result in step 303 is negative (No), that is, if the engine is in the open loop control operation region, the o2 feedback control is canceled and the correction coefficient Ko2 is set to the value 1.0 (step 305), and this program is executed. finish. The open-loop control operation region is, for example, the region ■ (lean operation region) shown in Fig. 2, a part of the region ■ (idle operation region) (the area not shaded), the region ■ (low-speed operation region), Area ■ (high load operation area) and area ■ (high rotation operation area) are included. The lean operating region ■ is a region where the intake pipe absolute pressure PBA is set to a large value as the engine speed Ne increases during engine deceleration, and is below the discriminant value P e ALJ, and the idle operating region ■ is a region where the engine speed Ne is the discriminant value NIDL. (For example 1000p
p m ) and the intake pipe absolute pressure PBA is lower than the discrimination value PBAIDL (for example, 360 mmt1g), and the low rotation operating region ■ is the region where the engine rotation speed Ne is lower than the discrimination value NLOP (for example, 600 rpm) and the intake pipe absolute pressure PBA is the discriminant value PBAIDL (for example, 360 mm
Hg) and the high load region discrimination value θWOT set according to the engine speed Ne, the high load operation region ■ is a region between the high load region discrimination value θWOT set according to the engine speed Ne, when the throttle valve opening θth is set to the above discrimination value θ at high load.
The region above WOT, the high-speed operation region (2), is a region where the engine speed Ne is above the discrimination value NHOP (for example, 3000 ppm).
第4図は第1図のNeセンサ10によりTDC信号発生
毎にCPUSb内で実行される減速補正係数値KIDL
を設定するためのKIDしサブルーチンのフローチャー
トを示す。Figure 4 shows the deceleration correction coefficient value KIDL which is executed in CPUUSb every time the TDC signal is generated by the Ne sensor 10 in Figure 1.
A flowchart of the KID subroutine for setting the KID is shown.
先ず、エンジンが前述のリーン化運転領域(第2図の領
域■)にあるか否かを判別しくステップ401)、リー
ン化運転領域になければ(判別結果が否定(No))ス
テップ402に進む。First, it is determined whether or not the engine is in the aforementioned lean operating region (region ■ in FIG. 2) (step 401), and if it is not in the lean operating region (determination result is negative (No)), the process proceeds to step 402. .
ステップ402では第1図のスロットル弁3′の弁開度
値θthが所定判別値θFQ(例えば2°)より小さい
か否かを判別し、判別結果が肯定(Yes)の場合、即
ちoth値がoFC値より小さければステップ403に
進み、否定(NO)であれば通常のアクセル踏込状態で
あるので減速運転状態ではないと判断し、後述するフラ
グNeFLGを値0に設定しくステップ411)、ステ
ップ412に進む・
ステップ403ではエンジン回転数値Neが所定判別値
No、LSH(例えば1250rpm)を超えているか
否かを判別する。この判別はエンジンが高回転数領域(
第5図の斜線領域H)から減速を開始したか否かを判別
するものであり1判別結果が肯定(Yes)の場合、前
記フラグNeFLGを値1に設定しくステップ404)
、高回転数領域からの減速であることを記憶する。In step 402, it is determined whether the valve opening value θth of the throttle valve 3' shown in FIG. If it is smaller than the oFC value, the process proceeds to step 403, and if the answer is negative (NO), it is determined that the accelerator is in a normal accelerator depression state and therefore not in a deceleration driving state, and a flag NeFLG, which will be described later, is set to the value 0 (steps 411) and 412. Proceed to Step 403. In step 403, it is determined whether or not the engine speed value Ne exceeds a predetermined determination value No, LSH (for example, 1250 rpm). This determination is made when the engine is in a high rotation speed region (
It is determined whether or not deceleration has started from the shaded area H) in FIG. 5. If the result of determination 1 is affirmative (Yes), the flag NeFLG is set to the value 1 (step 404).
, it is memorized that the deceleration is from a high rotational speed region.
次に、エンジンが前述の02フイードバツク制御中であ
るか否か(換言すれば、エンジンが第5図の斜線領域に
にあるか否か)を判別する(ステップ405)、この判
別結果が否定(No)の場合には前記ステップ412、
肯定(Yes)の場合にはステップ406に夫々進む。Next, it is determined whether the engine is under the aforementioned 02 feedback control (in other words, whether the engine is in the shaded area in FIG. 5) (step 405), and if this determination result is negative ( If No), the step 412;
In the case of affirmation (Yes), the process proceeds to step 406, respectively.
ステップ406では前記フラグ値NepLGが値1か否
かを判別し、高回転数領域(第5図の斜線領域H)から
の減速であればこの判別結果は肯定(Yes)となり、
ステップ407に進む。In step 406, it is determined whether the flag value NepLG is 1 or not, and if the deceleration is from a high rotational speed region (shaded region H in FIG. 5), this determination result is affirmative (Yes).
Proceed to step 407.
ステップ407ではエンジン回転数値Neが判別値No
、LSH(1250rpm)より小さい所定判別値No
、LSL(例えば900rpm)より大きいか否かを判
別する。今回ループのステップ゛403での判別結果が
肯定(Yes)であれば当然ステップ407の判別結果
も肯定(Yes)となり、ステップ409に進む。又、
NepLG値が値1、即ち高回転数領域からの減速であ
り、今回ループのNe値がNo2LSL値より大きい場
合、即ちエンジン回転数値NeがNo2LSH値とNo
2Lsし値との間の中目転数領域(第5図の斜線領域M
)にある場合(第5図のエンジン作動線B)。In step 407, the engine rotation value Ne is the discrimination value No.
, a predetermined discrimination value No. smaller than LSH (1250 rpm)
, LSL (for example, 900 rpm). If the determination result in step 403 of this loop is affirmative (Yes), naturally the determination result in step 407 is also positive (Yes), and the process proceeds to step 409. or,
If the NepLG value is 1, that is, deceleration from a high rotation speed region, and the Ne value of this loop is larger than the No2LSL value, that is, the engine rotation value Ne is equal to the No2LSH value and No.
The middle eye roll number area between the 2Ls value (the shaded area M in Figure 5)
) (engine operating line B in Figure 5).
この場合にもステップ409に進む。In this case as well, the process proceeds to step 409.
一方、NeFLG値が値1であるがエンジン回転数Ne
が更に減少し、No2LSL値より小さい低回転数領域
(第5図の斜線領域L)に突入すると(第5図の破線で
示すエンジン作動線C)ステップ407の判別結果は否
定(No)となり、フラグ値NepL(、を値Oにリセ
ットしくステップ408)、ステップ412に進む。On the other hand, although the NeFLG value is 1, the engine speed Ne
further decreases and enters a low rotational speed region (shaded region L in FIG. 5) smaller than the No. 2 LSL value (engine operating line C shown by a broken line in FIG. 5), the determination result in step 407 becomes negative (No), The flag value NepL (, is reset to the value O (step 408), and the process proceeds to step 412.
前記ステップ406での判別結果が否定(No)の場合
、即ちエンジンが第5図の斜線領域にあり。If the determination result in step 406 is negative (No), that is, the engine is in the shaded area in FIG.
且つフラグ値NepL(、が零の場合にはエンジン回転
数Neが判別値NO□LSH以下の状態から減速を始め
たことを意味しく第5図のエンジン作動線A)、斯かる
場合には混合気のリッチ化の心配はないとしてステップ
412に進む。In addition, if the flag value NepL (, is zero, it means that deceleration has started from a state where the engine speed Ne is less than the discrimination value NO□LSH (engine operating line A in Fig. 5), and in such a case, the mixture It is assumed that there is no concern about enrichment of Qi, and the process proceeds to step 412.
ステップ409ではエンジンに供給される混合気が所定
空燃比1例えば理論空燃比よりも燃料リッチな状態にあ
るか否かを判別する。この判別は第1図の02センサ1
3の検出値信号の出力レベルが混合気のリッチ状態を示
す所定の基準レベルより高いか否かにより判別される。In step 409, it is determined whether the air-fuel mixture supplied to the engine has a predetermined air-fuel ratio 1, for example, a fuel richer state than the stoichiometric air-fuel ratio. This determination is made using the 02 sensor 1 in Figure 1.
The determination is made based on whether the output level of the detection value signal No. 3 is higher than a predetermined reference level indicating a rich state of the air-fuel mixture.
ステップ409の判別結果が肯定(Yes)の場合、即
ち混合気がリッチな状態にあればステップ410に進み
、スロットル弁3′を閉弁することによって吸気管内壁
に付着していた燃料が燃焼室内に供給されることによる
混合気のオーバーリッチ化、即ち排気ガス特性の悪化を
防止するため、減速補正係数KIDLを値0.95に設
定する。一方、混合気がリッチな状態になければ、過度
のリーン化によるエンジン運転性の悪化を防止するため
、減速補正係数KIDLを値1.0に設定する(ステッ
プ412)。If the determination result in step 409 is affirmative (Yes), that is, if the air-fuel mixture is in a rich state, the process proceeds to step 410, and by closing the throttle valve 3', the fuel adhering to the inner wall of the intake pipe is removed from the combustion chamber. The deceleration correction coefficient KIDL is set to a value of 0.95 in order to prevent over-richness of the air-fuel mixture, that is, deterioration of exhaust gas characteristics due to the supply of the fuel to the engine. On the other hand, if the air-fuel mixture is not in a rich state, the deceleration correction coefficient KIDL is set to a value of 1.0 in order to prevent engine drivability from deteriorating due to excessive lean (step 412).
ここで、前記ステップ401での判別結果が爵定(Ye
s)の場合、即ちエンジンがリーン化運転領域にあれば
前述のように両式(1)のリーン化補正係数KLsによ
り混合気がリーン化されるので。Here, the determination result in step 401 is determined (Ye).
In the case of s), that is, if the engine is in the lean operation region, the air-fuel mixture is made lean by the lean correction coefficient KLs of both equations (1), as described above.
二重のリーン化を防止するためステップ411を介して
ステップ412に進み、補正係数に、、しを値1.0に
設定する。又、前記ステップ402での判別結果が否定
(No)の場合、即ちアクセルの踏込状態のとき、ステ
ップ411を介してステップ412に進んで補正係数に
1.)Lを値1.0に設定した理由は、混合気をリーン
化することによリエンジンの出力が不足することを防止
するためである。In order to prevent double leanness, the process proceeds to step 412 via step 411, and the correction coefficients are set to a value of 1.0. If the determination result in step 402 is negative (No), that is, if the accelerator is depressed, the process proceeds to step 412 via step 411, and the correction coefficient is set to 1. ) The reason why L is set to a value of 1.0 is to prevent the re-engine output from becoming insufficient due to making the air-fuel mixture lean.
前記ステップ405の判別結果が否定(No)の場合、
即ちエンジンが0□フイードバツク制御中ではない場合
には前述のように夫々の特定の運転状態に応じた補正係
数が適宜設定されているので、減速補正係数KIDLは
値1.0に設定される。If the determination result in step 405 is negative (No),
That is, when the engine is not under 0□ feedback control, the deceleration correction coefficient KIDL is set to a value of 1.0 because the correction coefficient is appropriately set according to each specific operating state as described above.
又、ステップ406の判別結果が否定(No)の場合、
即ちエンジン回転数Neが判別値No、Ls。Further, if the determination result in step 406 is negative (No),
That is, the engine speed Ne is the discrimination value No, Ls.
以下の状態から減速を開始したときには、スロットル弁
全開時における吸気管内壁に付着している燃料を吸い込
むことによる混合気の空燃比への影響が少なくなるので
、補正係数に、、しによるり−ン化は実行されない。When deceleration is started from the following conditions, the effect on the air-fuel ratio of the air-fuel mixture due to the suction of fuel adhering to the inner wall of the intake pipe when the throttle valve is fully open is reduced, so the correction coefficient is adjusted accordingly. conversion is not performed.
尚、上述のようにして設定された減速補正係数値KIt
+Lは両式(1)に適用され、燃料噴射弁6の燃料噴射
時間TOIJTが設定される。It should be noted that the deceleration correction coefficient value KIt set as described above
+L is applied to both equations (1), and the fuel injection time TOIJT of the fuel injection valve 6 is set.
(発明の効果)
以上詳述したように、本発明の内燃エンジンの減速時燃
料供給制御方法に依れば、内燃エンジンに供給する混合
気の空燃比をフィートバッタ制御する燃料供給制御方法
において、エンジン回転数を検出し、前記内燃エンジン
が減速運転状態にあるか否かを検出し、前記内燃エンジ
ンが減速運転状態にあり、且つ、エンジン回転数検出値
が第1の所定エンジン回転数値より大きい値から該第1
の所定エンジン回転数値より小さい第2の所定エンジン
回転数値迄減少する間に亘って、前記排気ガス成分濃度
検出手段からの検出値に応じて前記内燃エンジンに供給
する混合気の空燃比をリーン化するようにしたので、高
エンジン回転数からの減速時におけるエンジンの排気ガ
ス特性の悪化を・防止できる。(Effects of the Invention) As detailed above, according to the fuel supply control method during deceleration of an internal combustion engine of the present invention, in the fuel supply control method for controlling the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine, detecting an engine rotation speed; detecting whether the internal combustion engine is in a deceleration operation state; the internal combustion engine is in a deceleration operation state, and the engine rotation speed detection value is greater than a first predetermined engine rotation value; from the value
The air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine is made lean in accordance with the detected value from the exhaust gas component concentration detection means, while the engine speed decreases to a second predetermined engine speed smaller than the predetermined engine speed. This makes it possible to prevent deterioration of engine exhaust gas characteristics during deceleration from a high engine speed.
第1図は本発明の適用した内燃エンジンの燃料供給制御
装置、第2図はエンジンの運転領域図、第3図は02フ
ィードバック補正係数Ko、の算出サブルーチンを示す
フローチャート、第4図は本発明に係る減速補正係数K
IDLの算出サブルーチンを示すフローチャート、第5
図は02フィートバック運転領域図である。
1・・・内燃エンジン、3′・・・スロットル弁、4・
・・スロットル弁開度センサ、5・・・電子コントロー
ルユニット(ECU)、6・・・燃料噴射弁、8・・・
絶対圧センサ、10・・・エンジン回転数センサ(Ne
センサ)、11・・・排気通路、13・・・排気ガス成
分濃度検出手段(02センサ)。Fig. 1 is a fuel supply control system for an internal combustion engine to which the present invention is applied, Fig. 2 is an engine operating range diagram, Fig. 3 is a flowchart showing a subroutine for calculating the 02 feedback correction coefficient Ko, and Fig. 4 is a flowchart showing the subroutine for calculating the 02 feedback correction coefficient Ko. Deceleration correction coefficient K
Flowchart showing IDL calculation subroutine, No. 5
The figure shows the 02 footback driving range. 1... Internal combustion engine, 3'... Throttle valve, 4.
...Throttle valve opening sensor, 5...Electronic control unit (ECU), 6...Fuel injection valve, 8...
Absolute pressure sensor, 10...Engine speed sensor (Ne
sensor), 11...exhaust passage, 13...exhaust gas component concentration detection means (02 sensor).
Claims (1)
濃度検出手段からの検出値信号に基づいて該内燃エンジ
ンに供給する混合気の空燃比をフィードバック制御する
燃料供給制御方法において、エンジン回転数を検出し、
前記内燃エンジンが減速運転状態にあるか否かを検出し
、前記内燃エンジンが減速運転状態にあり、且つ、エン
ジン回転数検出値が第1の所定エンジン回転数値より大
きい値から該第1の所定エンジン回転数値より小さい第
2の所定エンジン回転数値迄減少する間に亘って、前記
排気ガス成分濃度検出手段からの検出値に応じて前記内
燃エンジンに供給する混合気の空燃比をリーン化するこ
とを特徴とする内燃エンジンの減速時燃料供給制御方法
。 2、前記排気ガス成分濃度検出手段からの検出値信号が
混合気をリーン化すべき値を示すとき、混合気の空燃比
を該検出値信号に基づいて設定される値より更にリーン
化することを特徴とする特許請求の範囲第1項記載の内
燃エンジンの減速時燃料供給制御方法。[Claims] 1. Fuel supply control that performs feedback control of the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine based on a detected value signal from an exhaust gas component concentration detection means disposed in the exhaust passage of the internal combustion engine. In the method, detecting engine rotation speed;
detecting whether or not the internal combustion engine is in a decelerating operating state; and detecting whether or not the internal combustion engine is in a decelerating operating state, and from a value in which the internal combustion engine is in a decelerating operating state and a detected engine rotational speed value is larger than a first predetermined engine rotational value, the first predetermined engine rotational speed value is Leaning the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine according to the detected value from the exhaust gas component concentration detection means during the period when the engine speed decreases to a second predetermined engine speed smaller than the engine speed. A method for controlling fuel supply during deceleration of an internal combustion engine, characterized by: 2. When the detection value signal from the exhaust gas component concentration detection means indicates a value at which the mixture should be made lean, the air-fuel ratio of the mixture is made leaner than the value set based on the detection value signal. A method for controlling fuel supply during deceleration of an internal combustion engine as claimed in claim 1.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22116484A JPS61101636A (en) | 1984-10-23 | 1984-10-23 | Method of controlling fuel supply to internal-combustion engine at the time of its deceleration |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22116484A JPS61101636A (en) | 1984-10-23 | 1984-10-23 | Method of controlling fuel supply to internal-combustion engine at the time of its deceleration |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61101636A true JPS61101636A (en) | 1986-05-20 |
Family
ID=16762471
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP22116484A Pending JPS61101636A (en) | 1984-10-23 | 1984-10-23 | Method of controlling fuel supply to internal-combustion engine at the time of its deceleration |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61101636A (en) |
-
1984
- 1984-10-23 JP JP22116484A patent/JPS61101636A/en active Pending
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