JP2996043B2 - Air-fuel ratio control device for internal combustion engine - Google Patents
Air-fuel ratio control device for internal combustion engineInfo
- Publication number
- JP2996043B2 JP2996043B2 JP5038357A JP3835793A JP2996043B2 JP 2996043 B2 JP2996043 B2 JP 2996043B2 JP 5038357 A JP5038357 A JP 5038357A JP 3835793 A JP3835793 A JP 3835793A JP 2996043 B2 JP2996043 B2 JP 2996043B2
- Authority
- JP
- Japan
- Prior art keywords
- amount
- oxygen
- air
- fuel ratio
- way catalyst
- 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 - Fee Related
Links
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
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
- F02D41/1456—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio with sensor output signal being linear or quasi-linear with the concentration of oxygen
Landscapes
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、排気系に三元触媒コン
バータを有する内燃機関の空燃比制御装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-fuel ratio control device for an internal combustion engine having a three-way catalytic converter in an exhaust system.
【０００２】[0002]
【従来の技術】一般的に内燃機関の排気系には、排気ガ
ス中の有害成分を浄化するための触媒コンバータが設け
られている。この触媒コンバータとして、三元触媒コン
バータが広く使用されており、これは排気ガス中の有害
三成分である一酸化炭素及び炭化水素を酸化すると共に
酸化窒素を還元して、無害な二酸化炭素、水蒸気、及び
窒素に変換させるものである。この三元触媒コンバータ
による浄化特性は、燃焼室内に形成される混合気の空燃
比に依存し、それが理論空燃比近傍である時に三元触媒
コンバータは最も有効に機能することがわかっている。
これは、空燃比がリーンであり排気ガス中の酸素量が多
いと、酸化作用が活発となるが還元作用が不活発とな
り、また空燃比がリッチであり排気ガス中の酸素量が少
ないと、逆に還元作用が活発となるが酸化作用が不活発
となり、前述の有害三成分を全て良好に浄化させること
ができないためである。従って、三元触媒コンバータを
有する内燃機関には、その排気通路に出力リニア型酸素
センサが設けられ、それにより測定される酸素濃度を使
用して燃焼室内の混合気を理論空燃比にフィードバック
制御することが提案されている。但し、本明細書中で使
用する酸素濃度とは、混合気空燃比がリッチ状態の時の
排気ガスにおいては、その程度に応じた負の値となるも
のである。2. Description of the Related Art Generally, an exhaust system of an internal combustion engine is provided with a catalytic converter for purifying harmful components in exhaust gas. As this catalytic converter, a three-way catalytic converter is widely used, which oxidizes carbon monoxide and hydrocarbons, which are harmful three components in exhaust gas, and reduces nitrogen oxides to produce harmless carbon dioxide and steam. , And nitrogen. The purification characteristics of the three-way catalytic converter depend on the air-fuel ratio of the air-fuel mixture formed in the combustion chamber, and it has been found that the three-way catalytic converter functions most effectively when it is near the stoichiometric air-fuel ratio.
This is because when the air-fuel ratio is lean and the amount of oxygen in the exhaust gas is large, the oxidizing action becomes active but the reducing action becomes inactive, and when the air-fuel ratio is rich and the amount of oxygen in the exhaust gas is small, Conversely, the reducing action becomes active, but the oxidizing action becomes inactive, and it is not possible to satisfactorily purify all the three harmful components described above. Therefore, an internal combustion engine having a three-way catalytic converter is provided with an output linear type oxygen sensor in its exhaust passage, and performs feedback control of the air-fuel mixture in the combustion chamber to the stoichiometric air-fuel ratio using the oxygen concentration measured thereby. It has been proposed. However, the oxygen concentration used in the present specification is a negative value corresponding to the degree of the exhaust gas when the air-fuel ratio is rich.
【０００３】このようなフィードバック制御を実行して
も、機関過渡運転状態の時、例えば、機関加速時は吸気
量が急増するために混合気空燃比は一時的にリーン状態
となり、また機関減速時は逆にリッチ状態となる。この
時、通常であれば三元触媒の排気ガスの浄化性能が低下
するが、三元触媒に酸素を貯蔵する能力（Ｏ2 ストレー
ジ効果）を持たせることが提案されており、それにより
空燃比がリーン状態の時に余分な酸素を貯蔵し、またリ
ッチ状態の時に貯蔵された酸素を使用することにより、
排気ガスの浄化性能を維持することができる。Even if such feedback control is executed, the air-fuel ratio of the air-fuel mixture temporarily becomes lean during an engine transient operation state, for example, when the engine is accelerating, because the intake air amount sharply increases. Becomes a rich state on the contrary. At this time, the purification performance of the exhaust gas of the three-way catalyst is normally reduced, but it has been proposed that the three-way catalyst has an ability to store oxygen (O 2 storage effect), thereby increasing the air-fuel ratio. By storing extra oxygen when the device is lean and using oxygen stored when it is rich,
Exhaust gas purification performance can be maintained.
【０００４】特開平３−２１７６３３号公報には、機関
過渡運転状態に対して三元触媒のＯ 2 ストレージ効果を
有効に利用するために、空燃比が必然的にリーン又はリ
ッチ状態となる時に、その後空燃比を意図的に反対の状
態にし、三元触媒に貯蔵される酸素を所定量に維持すべ
く、空燃比リーン状態において新たに貯蔵される酸素量
と空燃比リッチ状態において使用される酸素量とを等し
くするように制御する空燃比制御が提案されている。[0004] JP-A-3-217633 discloses an engine.
Three-way catalyst O for transient operating conditions TwoStorage effect
For effective use, the air-fuel ratio must be lean or
The air-fuel ratio is deliberately reversed
And maintain a predetermined amount of oxygen stored in the three-way catalyst.
And the amount of oxygen newly stored in the air-fuel ratio lean condition
And the amount of oxygen used in the rich air-fuel ratio condition
There has been proposed an air-fuel ratio control for controlling the air-fuel ratio.
【０００５】[0005]
【発明が解決しようとする課題】前述の空燃比制御にお
いて、排気ガスの酸素濃度を時間積分することによって
現在三元触媒の貯蔵されている酸素量を計算している。
従って、特に空燃比がかなりのリーン状態となる機関急
加速時において、この時の排気ガス中の酸素濃度がかな
り高くなるだけでなく空燃比を意図的にリッチ状態とす
るまでの時間も長くなるために、酸素量の計算値は非常
に大きなものとなる。この値が、実際に三元触媒に貯蔵
できる酸素量を越える可能性があり、この時前述の従来
技術では、空燃比リッチ状態が過剰に維持され、三元触
媒に貯蔵される酸素量が所定量を下回ったままとされ
る。その後三元触媒の酸素貯蔵量を正確に把握できない
だけでなく、遂には排気エミッションを悪化させるため
に意図的に空燃比をリッチ状態とすることになる。また
機関急減速時において、三元触媒に貯蔵されている所定
量の酸素が全て使用されたにもかかわらず、さらに酸素
を使用したように計算され、過剰に空燃比をリーン状態
に維持することになり、この時にも前述と同様な問題を
生じる。In the above-described air-fuel ratio control, the amount of oxygen currently stored in the three-way catalyst is calculated by integrating the oxygen concentration of the exhaust gas with time.
Therefore, particularly at the time of rapid engine acceleration in which the air-fuel ratio becomes considerably lean, not only the oxygen concentration in the exhaust gas at this time becomes considerably high, but also the time until the air-fuel ratio is intentionally made rich is long. Therefore, the calculated value of the oxygen amount becomes very large. This value may exceed the amount of oxygen that can be actually stored in the three-way catalyst. At this time, according to the above-described conventional technology, the air-fuel ratio rich state is maintained excessively, and the amount of oxygen stored in the three-way catalyst is limited. It remains below the quantification. After that, not only cannot the oxygen storage amount of the three-way catalyst be accurately grasped, but also, finally, the air-fuel ratio is intentionally made rich in order to deteriorate the exhaust emission. In addition, at the time of rapid deceleration of the engine, even though all of the predetermined amount of oxygen stored in the three-way catalyst has been used, it is calculated that more oxygen is used, and the air-fuel ratio is maintained excessively lean. In this case, the same problem as described above occurs.
【０００６】従って、本発明の目的は、三元触媒の酸素
貯蔵量を正確に把握してそれを所定量に維持し、排気エ
ミッションの悪化を確実に防止することができる内燃機
関の空燃比制御装置を提供することである。SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to control the air-fuel ratio of an internal combustion engine capable of accurately grasping the oxygen storage amount of a three-way catalyst and maintaining it at a predetermined amount, thereby reliably preventing the deterioration of exhaust emissions. It is to provide a device.
【０００７】[0007]
【課題を解決するための手段】本発明による内燃機関の
空燃比制御装置は、三元触媒に流入する排気ガス量及び
その酸素濃度を使用して現在前記三元触媒に貯蔵されて
いる酸素量を算出する酸素量算出手段及びこの酸素量が
前記三元触媒の有する最大及び最小酸素貯蔵量の範囲か
ら外れないように抑制する抑制手段を有する酸素量把握
手段と、前記酸素量把握手段により把握された前記酸素
量を所定量に維持すべく吸入空気量を考慮して機関燃焼
室に供給する燃料量を制御する燃料量制御手段、とを具
備することを特徴とする。An air-fuel ratio control apparatus for an internal combustion engine according to the present invention uses the amount of exhaust gas flowing into a three-way catalyst and the oxygen concentration thereof to determine the amount of oxygen currently stored in the three-way catalyst. And an oxygen amount calculating means having an oxygen amount calculating means for calculating the oxygen amount calculating means, and a suppressing means for suppressing the oxygen amount from falling outside the range of the maximum and minimum oxygen storage amounts of the three-way catalyst. Fuel amount control means for controlling the amount of fuel supplied to the engine combustion chamber in consideration of the amount of intake air in order to maintain the oxygen amount kept at a predetermined amount.
【０００８】[0008]
【作用】前述の内燃機関の空燃比制御装置は、酸素量把
握手段が三元触媒に流入する排気ガス量及びその酸素濃
度を使用して現在前記三元触媒に貯蔵されている酸素量
を算出する酸素量算出手段及びこの酸素量が前記三元触
媒の有する最大及び最小酸素貯蔵量の範囲から外れない
ように抑制する抑制手段を有し、この把握手段によって
三元触媒に貯蔵されている酸素量を把握し、燃料量制御
手段がこの酸素量を所定量に維持すべく吸入空気量を考
慮して機関燃焼室に供給する燃料量を制御する。In the above-described air-fuel ratio control device for an internal combustion engine, the oxygen amount grasping means calculates the amount of oxygen currently stored in the three-way catalyst using the amount of exhaust gas flowing into the three-way catalyst and the oxygen concentration thereof. Means for calculating the amount of oxygen to be stored and suppressing means for suppressing the amount of oxygen from falling outside the range of the maximum and minimum oxygen storage amounts of the three-way catalyst. The amount is grasped, and the fuel amount control means controls the amount of fuel supplied to the engine combustion chamber in consideration of the intake air amount so as to maintain the oxygen amount at a predetermined amount.
【０００９】[0009]
【実施例】図１は、本発明による内燃機関の空燃比制御
装置の構成を示すブロック図である。同図において、１
は内燃機関、２はその排気系に設置された三元触媒、３
は排気系の三元触媒２上流に設けられた出力リニア型酸
素センサである。４は機関運転状態に応じて基本燃料噴
射量τ１を決定する基本燃料噴射量決定器、５は減算
器、６は制御器、７は乗算器である。制御器６は、動特
性を調整する回路、すなわち閉ループ制御を高速にする
回路である動特性回路６ａと、積分器６ｂと、積分制御
器６ｃと、結合点６ｄとが図１に示すように配置されて
いる。FIG. 1 is a block diagram showing the configuration of an air-fuel ratio control apparatus for an internal combustion engine according to the present invention. In the figure, 1
Is an internal combustion engine, 2 is a three-way catalyst installed in the exhaust system, 3
Is an output linear oxygen sensor provided upstream of the three-way catalyst 2 in the exhaust system. Reference numeral 4 denotes a basic fuel injection amount determiner that determines the basic fuel injection amount τ1 according to the engine operating state, 5 denotes a subtractor, 6 denotes a controller, and 7 denotes a multiplier. As shown in FIG. 1, the controller 6 includes a circuit for adjusting the dynamic characteristic, that is, a dynamic characteristic circuit 6a which is a circuit for increasing the speed of the closed loop control, an integrator 6b, an integral controller 6c, and a connection point 6d. Are located.
【００１０】このように構成された内燃機関の空燃比制
御装置は、基本燃料噴射量決定器４が図２に示す第１フ
ローチャートに従って所定時間毎に基本燃料噴射量τ１
を決定すると共に、それと同期して制御器６が図３に示
す第２フローチャートに従って補正係数ｋを決定し、両
者が乗算器７へ出力され、そこで計算された燃料噴射量
τを基に燃料噴射を実行するものである。In the air-fuel ratio control device for an internal combustion engine thus configured, the basic fuel injection amount determiner 4 determines the basic fuel injection amount τ1 at predetermined time intervals according to the first flowchart shown in FIG.
The controller 6 determines the correction coefficient k in accordance with the second flowchart shown in FIG. 3 in synchronism therewith, and the correction coefficient k is output to the multiplier 7, and the fuel injection amount is calculated based on the calculated fuel injection amount τ. Is to execute.
【００１１】第１フローチャートは、ステップ１０１に
おいて、内燃機関１に設けられた回転センサ（図示せ
ず）及びエアフローメータ（図示せず）によって機関回
転数Ｎ及び吸気量Ｑを測定し、ステップ１０２におい
て、これらの値を基にマップ等を利用して基本燃料噴射
量τ１を決定するものである。In a first flowchart, the engine speed N and the intake air amount Q are measured by a rotation sensor (not shown) and an air flow meter (not shown) provided in the internal combustion engine 1 in step 101, and in step 102 Based on these values, the basic fuel injection amount τ1 is determined by using a map or the like.
【００１２】次に第２フローチャートを説明する。まず
ステップ２０１において、酸素センサ３により排気ガス
中の酸素濃度λ１を測定し、ステップ２０２において、
減算器５によりこの酸素濃度λ１と理論空燃比混合気の
排気ガス中の酸素濃度λ２との偏差Δλを算出する。こ
のΔλは混合気がリーン状態であれば正の値となり、リ
ッチ状態であれば負の値となる。Next, a second flowchart will be described. First, in step 201, the oxygen concentration λ1 in the exhaust gas is measured by the oxygen sensor 3, and in step 202,
The difference Δλ between the oxygen concentration λ1 and the oxygen concentration λ2 in the exhaust gas of the stoichiometric air-fuel mixture is calculated by the subtractor 5. This Δλ has a positive value when the air-fuel mixture is in a lean state, and has a negative value when the air-fuel mixture is in a rich state.
【００１３】次にステップ２０３において、このΔλが
制御器６の積分器６ｂへ入力され、この時の排気ガス量
Ｅを考慮して時間積分され、現在三元触媒２に貯蔵され
ている酸素量ＦＬが計算される。この酸素量ＦＬは、近
似的に前回の酸素量ＦＬにΔλと本フローチャートの処
理間隔Δｔと排気ガス量Ｅとの積を加えることによって
計算される。排気ガス量Ｅは、直接測定してもよいが、
第１フローチャートにおいて測定された吸気量Ｑを近似
的に使用することもできる。Next, at step 203, this Δλ is input to the integrator 6b of the controller 6, time-integrated in consideration of the exhaust gas amount E at this time, and the oxygen amount currently stored in the three-way catalyst 2. FL is calculated. This oxygen amount FL is approximately calculated by adding the product of Δλ, the processing interval Δt of this flowchart, and the exhaust gas amount E to the previous oxygen amount FL approximately. Although the exhaust gas amount E may be measured directly,
The intake air amount Q measured in the first flowchart can be approximately used.
【００１４】次にステップ２０４において、積分制御器
６ｃに三元触媒２の最大酸素貯蔵量ＦＬＭＡＸが入力さ
れ、ステップ２０５において、積分制御器６ｃで酸素量
ＦＬが最大酸素貯蔵量ＦＬＭＡＸより大きいかどうかが
判断される。この判断が否定される時はそのまま、また
肯定される時はステップ２０６において酸素量ＦＬはＦ
ＬＭＡＸとされ、ステップ２０７に進む。三元触媒にお
ける最大酸素貯蔵量ＦＬＭＡＸの求め方は、既に公知と
なっているために省略する。Next, at step 204, the maximum oxygen storage amount FLMAX of the three-way catalyst 2 is input to the integral controller 6c. At step 205, whether the oxygen amount FL is larger than the maximum oxygen storage amount FLMAX at the integral controller 6c is determined. Is determined. When this determination is denied, the oxygen amount FL is changed to F in step 206.
LMAX, and the process proceeds to step 207. The method of obtaining the maximum oxygen storage amount FLMAX in the three-way catalyst is omitted since it is already known.
【００１５】ステップ２０７において、酸素量ＦＬが、
三元触媒の最小酸素貯蔵量である０未満となっているか
どうかが判断される。この判断が否定される時はそのま
ま、また肯定される時はステップ２０８において酸素量
ＦＬは０とされ、ステップ２０９に進む。ステップ２０
９において、積分制御器６ｃにはさらに三元触媒の目標
酸素貯蔵量ＩＳが入力され、ステップ２１０において、
酸素量ＦＬが目標酸素貯蔵量ＩＳより大きいかどうかが
判断され、この判断が肯定される時、ステップ２１１に
おいて制御値ＦＩは１だけ増加され、この判断が否定さ
れる時、ステップ２１２において制御値ＦＩは１だけ減
少される。In step 207, the oxygen amount FL becomes
It is determined whether or not the value is less than 0, which is the minimum oxygen storage amount of the three-way catalyst. When this determination is denied, as it is, and when this determination is affirmed, in step 208 the oxygen amount FL is set to 0, and the routine proceeds to step 209. Step 20
In 9, the target oxygen storage amount IS of the three-way catalyst is further input to the integral controller 6 c, and in step 210,
It is determined whether or not the oxygen amount FL is greater than the target oxygen storage amount IS. If the determination is affirmative, the control value FI is increased by 1 in step 211, and if the determination is negative, the control value FI is determined in step 212. FI is reduced by one.
【００１６】次にステップ２１３において、前述の偏差
Δλは制御器６の動特性回路６ａに入力されて動的制御
値ＦＤが算出され、ステップ２１４において、結合点６
ｄで制御値ＦＩと動的制御値ＦＤから補正係数ｋを算出
する。Next, at step 213, the above-mentioned deviation Δλ is input to the dynamic characteristic circuit 6a of the controller 6 to calculate a dynamic control value FD.
At d, a correction coefficient k is calculated from the control value FI and the dynamic control value FD.
【００１７】図４は、機関急加速時における混合気空燃
比のタイムチャートである。一般的な空燃比制御によれ
ば、混合気空燃比は実線で示すように理論空燃比を下回
ることなく、それに徐々に近づけられるが、本実施例及
び前述の従来技術によれば、空燃比は点線及び一点鎖線
で示すように理論空燃比を下回った後、それに徐々に近
づけられる。図５は、この時の本実施例及び前述の従来
技術による酸素貯蔵量の計算値のタイムチャートであ
る。前述の従来技術における計算値は、一点鎖線で示す
ように三元触媒２の最大酸素貯蔵量を越える可能性があ
り、その時にでも、この値を基に混合気空燃比が意図的
にリッチ状態にされるために、計算では酸素量が目標酸
素貯蔵量に維持されているように成っているが、実際の
酸素貯蔵量は、図６に示すように計算された酸素量が最
大酸素貯蔵量を越えた分だけ、目標酸素貯蔵量を下回っ
ている。FIG. 4 is a time chart of the air-fuel ratio of the air-fuel mixture during rapid acceleration of the engine. According to the general air-fuel ratio control, the air-fuel ratio of the air-fuel mixture does not fall below the stoichiometric air-fuel ratio as shown by the solid line, but gradually approaches the stoichiometric air-fuel ratio. After dropping below the stoichiometric air-fuel ratio as shown by the dotted line and the dashed line, the air-fuel ratio is gradually approached. FIG. 5 is a time chart of the calculated value of the oxygen storage amount at this time according to the present embodiment and the above-described conventional technology. The calculated value in the prior art described above may possibly exceed the maximum oxygen storage amount of the three-way catalyst 2 as indicated by the one-dot chain line, and even at that time, the air-fuel mixture is intentionally rich based on this value. Therefore, the calculation is such that the oxygen amount is maintained at the target oxygen storage amount, but the actual oxygen storage amount is calculated as shown in FIG. The amount of oxygen stored is lower than the target oxygen storage.
【００１８】このように計算値が実際の酸素貯蔵量から
外れると、その後は、三元触媒に貯蔵されている酸素量
を正確に把握することはできず、意図的に空燃比をリッ
チ状態にすることは、単に排気エミッションを悪化させ
ることになりかねない。一方、本実施例における計算値
は、点線で示すように三元触媒２の最大酸素貯蔵量を上
回ることがないように抑制され、この値を基に混合気空
燃比が意図的にリッチ状態にされるために、実際の酸素
量を計算値通りに目標酸素貯蔵量に維持することがで
き、このような問題を生じることはない。If the calculated value deviates from the actual oxygen storage amount in this manner, the amount of oxygen stored in the three-way catalyst cannot be accurately grasped thereafter, and the air-fuel ratio is intentionally set to a rich state. Doing so can simply exacerbate exhaust emissions. On the other hand, the calculated value in the present embodiment is suppressed so as not to exceed the maximum oxygen storage amount of the three-way catalyst 2 as shown by the dotted line, and based on this value, the air-fuel mixture is intentionally made rich. Therefore, the actual oxygen amount can be maintained at the target oxygen storage amount as calculated, and such a problem does not occur.
【００１９】機関急減速時においても、本実施例の空燃
比制御は、三元触媒２に貯蔵される酸素量の計算値がそ
の最小酸素貯蔵量であるゼロを下回ることがないように
抑制されるために、常に正確な酸素量を把握することが
でき、三元触媒のＯ2 ストレージ効果を有効に利用して
機関過渡運転状態における排気エミッションの悪化を防
止することができる。Even during rapid deceleration of the engine, the air-fuel ratio control of the present embodiment is suppressed so that the calculated value of the amount of oxygen stored in the three-way catalyst 2 does not fall below zero, which is the minimum amount of stored oxygen. Therefore, an accurate oxygen amount can be always grasped, and deterioration of exhaust emission in a transient operation state of the engine can be prevented by effectively utilizing the O 2 storage effect of the three-way catalyst.
【００２０】また、前述の従来技術は、三元触媒に貯蔵
される酸素量の計算において、排気ガス量が考慮されて
おらず、それによっても三元触媒に貯蔵される酸素量を
正確に把握することはできない。In the above-mentioned prior art, the amount of exhaust gas is not taken into account in the calculation of the amount of oxygen stored in the three-way catalyst, so that the amount of oxygen stored in the three-way catalyst can be accurately determined. I can't.
【００２１】[0021]
【発明の効果】このように、本発明による内燃機関の空
燃比制御装置によれば、現在三元触媒に貯蔵されている
酸素量を正確に把握することができるために、吸入空気
量に対して燃料供給量を制御することで、三元触媒の酸
素貯蔵量を所定量に維持することができ、必然的に空燃
比がリーン状態となる時に、三元触媒が余分な酸素をさ
らに貯蔵して、この時の排気ガスを良好に浄化すること
ができ、またリッチ状態となる時に、貯蔵された酸素を
使用することでこの時の排気ガスを良好に浄化すること
ができる。As described above, according to the air-fuel ratio control apparatus for an internal combustion engine according to the present invention, the amount of oxygen currently stored in the three-way catalyst can be accurately grasped. By controlling the fuel supply amount, the oxygen storage amount of the three-way catalyst can be maintained at a predetermined amount, and when the air-fuel ratio necessarily becomes lean, the three-way catalyst further stores excess oxygen. Thus, the exhaust gas at this time can be satisfactorily purified, and when the state becomes rich, the stored exhaust gas can be satisfactorily purified by using the stored oxygen.
【図１】本発明による内燃機関の空燃比制御装置の構成
を示すブロック図である。FIG. 1 is a block diagram showing a configuration of an air-fuel ratio control device for an internal combustion engine according to the present invention.
【図２】基本燃料噴射量決定のための第１フローチャー
トである。FIG. 2 is a first flowchart for determining a basic fuel injection amount.
【図３】補正係数決定のための第２フローチャートであ
る。FIG. 3 is a second flowchart for determining a correction coefficient.
【図４】機関急加速時における空燃比のタイムチャート
である。FIG. 4 is a time chart of an air-fuel ratio during rapid engine acceleration.
【図５】機関急加速時における三元触媒の酸素貯蔵量の
計算値のタイムチャートである。FIG. 5 is a time chart of a calculated value of the oxygen storage amount of the three-way catalyst during rapid engine acceleration.
【図６】従来技術による三元触媒の実際の酸素貯蔵量の
タイムチャートである。FIG. 6 is a time chart of an actual oxygen storage amount of a three-way catalyst according to the related art.
【符号の説明】 １…内燃機関 ２…三元触媒 ３…出力リニア型酸素センサ ４…基本燃料噴射量決定器 ５…減算器 ６…制御器 ７…乗算器[Description of Signs] 1 ... Internal combustion engine 2 ... Three-way catalyst 3 ... Output linear oxygen sensor 4 ... Basic fuel injection amount determiner 5 ... Subtractor 6 ... Controller 7 ... Multiplier
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平４−8856（ＪＰ，Ａ) 特開 平２−230935（ＪＰ，Ａ) 特開 平４−63936（ＪＰ，Ａ) 特開 平４−342848（ＪＰ，Ａ) 特開 平２−37144（ＪＰ，Ａ) 特開 平３−160134（ＪＰ，Ａ) 特開 平４−76243（ＪＰ，Ａ) 特開 昭64−36943（ＪＰ，Ａ) 特開 平４−237848（ＪＰ，Ａ) 特開 平３−217633（ＪＰ，Ａ) 特開 平６−17640（ＪＰ，Ａ) 実開 平１−166244（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.6，ＤＢ名) F02D 41/14 310 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-8856 (JP, A) JP-A-2-230935 (JP, A) JP-A-4-63936 (JP, A) JP-A-4- 342848 (JP, A) JP-A-2-37144 (JP, A) JP-A-3-160134 (JP, A) JP-A-4-76243 (JP, A) JP-A-64-36943 (JP, A) JP-A-4-237848 (JP, A) JP-A-3-217633 (JP, A) JP-A-6-17640 (JP, A) JP-A-1-166244 (JP, U) (58) Fields investigated (Int.Cl. 6 , DB name) F02D 41/14 310
Claims (1)
酸素濃度を使用して現在前記三元触媒に貯蔵されている
酸素量を算出する酸素量算出手段及びこの酸素量が前記
三元触媒の有する最大及び最小酸素貯蔵量の範囲から外
れないように抑制する抑制手段を有する酸素量把握手段
と、前記酸素量把握手段により把握された前記酸素量を
所定量に維持すべく吸入空気量を考慮して機関燃焼室に
供給する燃料量を制御する燃料量制御手段、とを具備す
ることを特徴とする内燃機関の空燃比制御装置。1. An oxygen amount calculating means for calculating an amount of oxygen currently stored in the three-way catalyst using an amount of exhaust gas flowing into the three-way catalyst and an oxygen concentration thereof, and the amount of oxygen being calculated by the three-way catalyst. An oxygen amount grasping means having a suppressing means for suppressing the amount of oxygen from being out of a range of the maximum and minimum oxygen storage amounts of the intake amount, and an intake air amount for maintaining the oxygen amount grasped by the oxygen amount grasping means at a predetermined amount. An air-fuel ratio control device for an internal combustion engine, comprising: a fuel amount control unit that controls a fuel amount supplied to an engine combustion chamber in consideration of the fuel amount.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5038357A JP2996043B2 (en) | 1993-02-26 | 1993-02-26 | Air-fuel ratio control device for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5038357A JP2996043B2 (en) | 1993-02-26 | 1993-02-26 | Air-fuel ratio control device for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06249028A JPH06249028A (en) | 1994-09-06 |
| JP2996043B2 true JP2996043B2 (en) | 1999-12-27 |
Family
ID=12523034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5038357A Expired - Fee Related JP2996043B2 (en) | 1993-02-26 | 1993-02-26 | Air-fuel ratio control device for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2996043B2 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3868693B2 (en) | 1999-03-03 | 2007-01-17 | 日産自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| DE10066194B4 (en) * | 1999-03-03 | 2005-12-08 | Nissan Motor Co., Ltd., Yokohama | Air/fuel ratio control system for automobile IC engine has air/fuel ratio inserted in exhaust line upstream of catalyser providing feedback signal used for controlling quantity of air for maintaining stoichiometric combustion |
| JP2001152928A (en) | 1999-11-30 | 2001-06-05 | Nissan Motor Co Ltd | Air-fuel ratio control device for internal combustion engine |
| JP3680217B2 (en) | 2000-06-26 | 2005-08-10 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| JP3622661B2 (en) * | 2000-10-06 | 2005-02-23 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| JP2002180876A (en) | 2000-12-07 | 2002-06-26 | Unisia Jecs Corp | Air-fuel ratio controller for internal combustion engine |
| JP3902399B2 (en) | 2000-12-08 | 2007-04-04 | 株式会社日立製作所 | Air-fuel ratio control device for internal combustion engine |
| DE10103772C2 (en) * | 2001-01-27 | 2003-05-08 | Omg Ag & Co Kg | Method for operating a three-way catalyst that contains an oxygen-storing component |
| DE60235778D1 (en) | 2001-06-18 | 2010-05-06 | Toyota Motor Co Ltd | Device for controlling the air-fuel ratio of an internal combustion engine |
| JP4023440B2 (en) | 2003-12-02 | 2007-12-19 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| JP4414384B2 (en) | 2005-08-23 | 2010-02-10 | 三菱電機株式会社 | Control device for internal combustion engine |
-
1993
- 1993-02-26 JP JP5038357A patent/JP2996043B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06249028A (en) | 1994-09-06 |
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