JPH0315978B2 - - Google Patents
Info
- Publication number
- JPH0315978B2 JPH0315978B2 JP58137113A JP13711383A JPH0315978B2 JP H0315978 B2 JPH0315978 B2 JP H0315978B2 JP 58137113 A JP58137113 A JP 58137113A JP 13711383 A JP13711383 A JP 13711383A JP H0315978 B2 JPH0315978 B2 JP H0315978B2
- Authority
- JP
- Japan
- Prior art keywords
- air
- fuel ratio
- pump
- pump current
- solid electrolyte
- 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 - Lifetime
Links
- 239000000446 fuel Substances 0.000 claims description 90
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 38
- 229910052760 oxygen Inorganic materials 0.000 claims description 38
- 239000001301 oxygen Substances 0.000 claims description 38
- 239000007784 solid electrolyte Substances 0.000 claims description 22
- 239000007789 gas Substances 0.000 claims description 11
- 239000003054 catalyst Substances 0.000 claims description 4
- 238000000746 purification Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 8
- 239000000203 mixture Substances 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 230000010354 integration Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 229910002076 stabilized zirconia Inorganic materials 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000004043 responsiveness Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/417—Systems using cells, i.e. more than one cell and probes with solid electrolytes
-
- 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
- F02D41/1473—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method
- F02D41/1475—Regulating the air fuel ratio at a value other than stoichiometry
- F02D41/1476—Biasing of the sensor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/406—Cells and probes with solid electrolytes
- G01N27/4065—Circuit arrangements specially adapted therefor
Description
【発明の詳細な説明】
この発明は、内燃機関などの排気ガス中の酸素
濃度を測定して空燃比を制御する装置に関し、特
にイオン伝導性固体電解質で構成された酸素ポン
プ式の空燃比センサを用いて空燃比制御を行うよ
うにしたものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that measures the oxygen concentration in the exhaust gas of an internal combustion engine and controls the air-fuel ratio, and particularly relates to an oxygen pump-type air-fuel ratio sensor made of an ion-conducting solid electrolyte. The air-fuel ratio is controlled using the
従来より、イオン伝導性固体電解質（たとえば
安定化ジルコニア）で構成された酸素センサを用
い、排気ガスの酸素分圧と空気の酸素分圧との差
によつて生じる起電力の変化によつて理論空燃比
での燃焼状態を検知することにより、たとえば、
自動車の機関を理論空燃比で運転するように制御
することは周知の通りである。 Conventionally, an oxygen sensor composed of an ion-conducting solid electrolyte (for example, stabilized zirconia) has been used, and the theory is based on the change in electromotive force caused by the difference between the oxygen partial pressure of exhaust gas and the oxygen partial pressure of air. By detecting the combustion state at the air-fuel ratio, for example,
It is well known that an automobile engine is controlled to operate at a stoichiometric air-fuel ratio.
ところで、上記酸素センサは空気と燃料との重
量比率である空燃比Ａ／Ｆが理論空燃比14.7であ
るときは大きな変化出力が得られるが、他の運転
空燃比域では出力変化がほとんどない。 By the way, the above-mentioned oxygen sensor can obtain a large change in output when the air-fuel ratio A/F, which is the weight ratio of air and fuel, is the stoichiometric air-fuel ratio of 14.7, but there is almost no change in output in other operating air-fuel ratio ranges.
したがつて、従来、この種の空燃比フイードバ
ツク制御は第１図に示す構成によつて行なわれて
いた。 Therefore, conventionally, this type of air-fuel ratio feedback control has been performed using the configuration shown in FIG.
この第１図の１００は空燃比センサ、１０１は
比較器、１０２は積分器、３３は混合気生成手段
であり、空燃比センサ１００は第２図に示すごと
く理論空燃比近傍において出力が反転する特性を
有している。 In FIG. 1, 100 is an air-fuel ratio sensor, 101 is a comparator, 102 is an integrator, and 33 is an air-fuel mixture generating means, and the output of the air-fuel ratio sensor 100 is reversed near the stoichiometric air-fuel ratio as shown in FIG. It has characteristics.
比較器１０１において空燃比センサ１００の出
力電圧が予め定めた比較電圧Vrefと比較され、
空燃比がリツチ側にあるかリーン側にあるかを判
別した結果に基づいて積分器１０２の積分方向が
第３図ａの空燃比センサ１００の出力電圧に対し
て、第３図ｂの空燃比制御量として示すように変
化させられ、この積分による制御量にしたがつて
混合気生成手段３３の空燃比が制御される。 A comparator 101 compares the output voltage of the air-fuel ratio sensor 100 with a predetermined comparison voltage Vref,
Based on the result of determining whether the air-fuel ratio is on the rich side or the lean side, the integration direction of the integrator 102 changes to the air-fuel ratio shown in FIG. 3b with respect to the output voltage of the air-fuel ratio sensor 100 shown in FIG. 3a. The air-fuel ratio of the air-fuel mixture generating means 33 is controlled in accordance with the control amount determined by the integral.
したがつて、空燃比の平均値は理論空燃比とな
り、空燃比の瞬時値は図のように周期TOでリツ
プル値CRを有した波形となる。 Therefore, the average value of the air-fuel ratio becomes the stoichiometric air-fuel ratio, and the instantaneous value of the air-fuel ratio becomes a waveform with a period T O and a ripple value C R as shown in the figure.
通常、積分器１０２の積分定数は機関の伝達遅
れに略対応させて設定されているが、機関の伝達
遅れ、すなわち、混合気生成手段３３により混合
気の濃度を制御してから排気ガス中の酸素濃度と
して検出されるまでの時間は機関の回転数や負荷
などの運転状態によつて大きく変化するため、積
分器１０２の積分定数を一義的に定めた場合、制
御周期TOやリツプル値CRの運転状態に対する変
動が大となる。 Normally, the integration constant of the integrator 102 is set to approximately correspond to the transmission delay of the engine. The time it takes to detect oxygen concentration varies greatly depending on engine speed, load, and other operating conditions. Therefore, if the integral constant of the integrator 102 is uniquely determined, the control period T O and ripple value C R fluctuates greatly depending on the operating condition.
リツプル値CRが大きいと排気経路に設置され
る排気ガス浄化のための三元触媒の浄化効率が低
下し、逆にリツプル値CRが小さ過ぎても浄化効
率が低下することが知られているが、従来の空燃
比フイードバツク制御においては、空燃比センサ
１００が理論空燃比点のみしか検出できない。 It is known that if the ripple value C R is large, the purification efficiency of the three-way catalyst installed in the exhaust path for purifying exhaust gas will decrease, and conversely, if the ripple value C R is too small, the purification efficiency will decrease. However, in conventional air-fuel ratio feedback control, the air-fuel ratio sensor 100 can only detect the stoichiometric air-fuel ratio point.
このため、積分回路により制御の応答性を考慮
した見込みの制御定数を用いて制御されており、
機関の運転状態によるリツプル値CRの変動を避
けることが不可能である。 For this reason, control is performed using an expected control constant that takes into account the responsiveness of the control using an integrating circuit.
It is impossible to avoid fluctuations in the ripple value CR due to engine operating conditions.
したがつて、三元触媒にとつて常に最適な空燃
比変動幅を得ることができなかつた。 Therefore, it has not been possible to always obtain the optimum air-fuel ratio fluctuation range for the three-way catalyst.
この発明は、上記従来の欠点を解消するための
もので、特開昭56−130649公報で提案されている
ような固体電解質酸素ポンプ式の酸素濃度測定装
置を用い、正確な理論空燃比の検知はもちろんの
こと、それ以外の空燃比をも検知することのでき
る空燃比センサを用いた空燃比制御装置を提供す
ることを目的とする。 This invention is intended to eliminate the above-mentioned conventional drawbacks, and uses a solid electrolyte oxygen pump type oxygen concentration measuring device as proposed in Japanese Patent Application Laid-Open No. 56-130649 to accurately detect the stoichiometric air-fuel ratio. It is an object of the present invention to provide an air-fuel ratio control device using an air-fuel ratio sensor that can detect not only air-fuel ratios but also other air-fuel ratios.
以下、この発明の空燃比制御装置の実施例につ
いて説明する。第４図はこの発明の一実施例を示
す構成図であり、第５図は第４図の−線に沿
う断面図である。図中、１は機関の排気管、２は
排気管１内に配設された空燃比センサである。 Embodiments of the air-fuel ratio control device of the present invention will be described below. FIG. 4 is a block diagram showing one embodiment of the present invention, and FIG. 5 is a sectional view taken along the line - in FIG. 4. In the figure, 1 is an exhaust pipe of the engine, and 2 is an air-fuel ratio sensor disposed inside the exhaust pipe 1.
空燃比センサ２は厚さが約0.5mmの平板状のイ
オン伝導性固体電解質（安定化ジルコニア）３の
両側面にそれぞれ白金電極４，５を設けて構成さ
れた固体電解質酸素ポンプ６と、この固体電解質
酸素ポンプ６と同じように平板状のイオン伝導性
固体電解質７の両側面にそれぞれ白金電極８およ
び９を設けて構成された固体電解質酸素センサ１
０と、上記固体電解質酸素ポンプ６と上記固体電
解質酸素センサ１０を0.1mm程度の微小間隙ｄを
介して対向配置するための支持台１１で構成され
ている。 The air-fuel ratio sensor 2 includes a solid electrolyte oxygen pump 6, which is composed of a flat plate-shaped ion-conductive solid electrolyte (stabilized zirconia) 3 with a thickness of approximately 0.5 mm, and platinum electrodes 4 and 5 provided on both sides thereof, respectively. Like the solid electrolyte oxygen pump 6, a solid electrolyte oxygen sensor 1 is constructed by providing platinum electrodes 8 and 9 on both sides of a flat ion-conducting solid electrolyte 7, respectively.
0, and a support base 11 for arranging the solid electrolyte oxygen pump 6 and the solid electrolyte oxygen sensor 10 facing each other with a minute gap d of about 0.1 mm in between.
１２は電子制御装置であり、固体電解質酸素セ
ンサ１０が微小間隙ｄ部内の酸素分圧とその間隙
ｄ部外の排気ガス中の酸素分圧に対応した起電力
ｅ即ち電極８，９間に発生する起電力ｅを抵抗
R1を介して演算増幅器Ａの反転入力端子（（−）
端子）に印加し、演算増幅器Ａの非反転入力端子
（（＋）端子）に印加されている基準電圧V1と上
記起電力ｅの差異に比例した演算増幅器Ａの出力
によりトランジスタTRを駆動して固体電解質酸
素ポンプ６の電極４，５間に流すポンプ電流IPを
制御する機能を備えている。 Reference numeral 12 denotes an electronic control device, in which the solid electrolyte oxygen sensor 10 generates an electromotive force e corresponding to the oxygen partial pressure within the minute gap d and the oxygen partial pressure in the exhaust gas outside the gap d, that is, generated between the electrodes 8 and 9. resists the electromotive force e
through R1 to the inverting input terminal of operational amplifier A ((-)
The transistor T R is driven by the output of the operational amplifier A which is proportional to the difference between the reference voltage V 1 applied to the non-inverting input terminal ((+) terminal) of the operational amplifier A and the electromotive force e mentioned above. The solid electrolyte oxygen pump 6 has a function of controlling the pump current I P flowing between the electrodes 4 and 5 of the solid electrolyte oxygen pump 6 .
すなわち、上記起電力ｅを所定値V1に保つの
に必要なポンプ電流IPを供給する作用をする。 That is, it functions to supply the pump current I P necessary to maintain the electromotive force e at a predetermined value V 1 .
また、ポンプ電流供給手段である直流電源Ｂか
ら供給されるポンプ電流IPに対応した出力信号を
得るための抵抗R0を備えている。 It also includes a resistor R 0 for obtaining an output signal corresponding to the pump current I P supplied from the DC power supply B serving as pump current supply means.
この抵抗R0は直流電源Ｂと対応して上記ポン
プ電流IPが過大に流れないような所望の抵抗値が
選ばれている。 This resistor R 0 corresponds to the DC power supply B, and a desired resistance value is selected so that the pump current I P does not flow excessively.
なお、Ｃはコンデンサ、Ｓは基準電圧をV1か
らV2に変更するための切換装置である。 Note that C is a capacitor, and S is a switching device for changing the reference voltage from V1 to V2 .
以上のように構成されたこの発明に適用される
空燃比センサを国産乗用車2000c.c.のガソリン機関
に装着して試験した結果を第６図に示す。過大な
ポンプ電流IPが流れると、固体電解質酸素ポンプ
６が破壊するので、ポンプ電流IPは100mA以上流
れないように直流電源Ｂにより制限した。 FIG. 6 shows the results of a test in which the air-fuel ratio sensor applied to the present invention configured as described above was installed in a gasoline engine of a domestic passenger car 2000c.c. If an excessive pump current I P flows, the solid electrolyte oxygen pump 6 will be destroyed, so the pump current I P is limited by the DC power supply B so that it does not flow more than 100 mA.
また、基準電圧V1は55mVとし、V2は200mV
に設定して試験した結果、切換装置Ｓにより基準
電圧をV1＝55mVにした場合は第６図に示す特性
ａが得られた。また上記切換装置Ｓにより上記基
準電圧をV2＝200mVに変更すると特性ｂが得ら
れた。なお、第６図におけるλ0は理論空燃比であ
る。 Also, the reference voltage V 1 is 55mV, and V 2 is 200mV.
As a result of the test, when the reference voltage was set to V 1 =55 mV by the switching device S, a characteristic a shown in FIG. 6 was obtained. Further, when the reference voltage was changed to V 2 =200 mV using the switching device S, characteristic b was obtained. Note that λ 0 in FIG. 6 is the stoichiometric air-fuel ratio.
第６図の特性が示すように、空燃比Ａ／Ｆが理
論空燃比λ0より大きい範囲で、ポンプ電流IPが空
燃比に比例して変化する理由は特開昭56−130649
号公報に記載されている。 The reason why the pump current I P changes in proportion to the air-fuel ratio in the range where the air-fuel ratio A/F is larger than the stoichiometric air-fuel ratio λ 0 , as shown by the characteristics in FIG.
It is stated in the No.
すなわち、微小間隙部ｄ内に導入された排気ガ
スの酸素分圧を上記固体電解質酸素ポンプ６の作
用により変更することにより、排気管１内を流れ
る排気ガスの酸素分圧と差異をもたせ、この酸素
分圧の差異に応じて発生する固体電解質酸素セン
サ１０の起電力ｅが所定値となるように固体電解
質酸素ポンプ６に供給されるポンプ電流IPを制御
するとき、このポンプ電流IPは排気ガス中の酸素
濃度に比例して変化する。 That is, by changing the oxygen partial pressure of the exhaust gas introduced into the minute gap d by the action of the solid electrolyte oxygen pump 6, it is made to differ from the oxygen partial pressure of the exhaust gas flowing in the exhaust pipe 1, and this When controlling the pump current I P supplied to the solid electrolyte oxygen pump 6 so that the electromotive force e of the solid electrolyte oxygen sensor 10 generated according to the difference in oxygen partial pressure becomes a predetermined value, this pump current I P is It changes in proportion to the oxygen concentration in the exhaust gas.
また、空燃比は上記酸素濃度にほぼ比例するの
で、結果的にポンプ電流IPは空燃比Ａ／Ｆに比例
して変化する。 Furthermore, since the air-fuel ratio is approximately proportional to the oxygen concentration, the pump current I P changes in proportion to the air-fuel ratio A/F.
ところで、理論空燃比より小さい範囲でポンプ
電流IPが変化するのは排気ガス中の一酸化炭素
（CO）濃度に空燃比センサ２が感応しているよう
に考えられる。 Incidentally, the reason why the pump current I P changes in a range smaller than the stoichiometric air-fuel ratio is considered to be because the air-fuel ratio sensor 2 is sensitive to the carbon monoxide (CO) concentration in the exhaust gas.
この発明は、前記第６図の特性ａを利用して空
燃比を理論空燃比近傍に制御しようとするもの
で、第４図に示す実施例に基づいてさらに詳細に
説明する。 This invention attempts to control the air-fuel ratio to near the stoichiometric air-fuel ratio by utilizing the characteristic a shown in FIG. 6, and will be explained in more detail based on the embodiment shown in FIG. 4.
第４図の３０はポンプ電流IPを電圧レベルに変
換する電流電圧変換器、３１は電流電圧変換器３
０の出力と予め定めた判定レベルVrefとを比較
する比較器、３２は比較器３１の比較結果に基づ
いて空燃比の増減割合を制御する積分器、３３は
混合気生成手段である。 In Fig. 4, 30 is a current-voltage converter that converts the pump current I P into a voltage level, and 31 is a current-voltage converter 3.
32 is an integrator that controls the increase/decrease rate of the air-fuel ratio based on the comparison result of the comparator 31, and 33 is an air-fuel mixture generating means.
上記の構成において、空燃比センサ２の特性は
第６図の特性ａに示すようなＶ字形特性となるよ
うに酸素センサ１０の起電力を設定しておき、ポ
ンプ電流IPはIP1以下の範囲つまり空燃比がλR〜λL
の範囲を使用する。 In the above configuration, the electromotive force of the oxygen sensor 10 is set so that the air-fuel ratio sensor 2 has a V-shaped characteristic as shown in characteristic a in FIG . The range or air fuel ratio is λ R ~ λ L
Use a range of
ポンプ電流IPの値は電流電圧変換器３０によつ
て回路的に処理のし易い電圧レベルに変換され、
予め定められた判定レベルVrefと比較される。
この判定レベルVrefは第６図のポンプ電流IP1に
相当する値に設定されており、たとえば実際のポ
ンプ電流IPが判定レベル相当のIP1（Ａ／Ｆ＝λLの
点）を超えると、その時点までの積分器の増減方
向を反転させ、第７図ａに示すごとく、空燃比セ
ンサ２の出力は理論空燃比λ0点を通過してさらに
第７図ｂの空燃比の制御量が同一方向に変化する
ように積分器３２が作動し、Ａ／Ｆ＝λRとなるポ
ンプ電流IP1に到達する。 The value of the pump current I P is converted by the current-voltage converter 30 to a voltage level that is easy to process in a circuit,
It is compared with a predetermined judgment level Vref.
This judgment level Vref is set to a value corresponding to the pump current I P1 in Fig. 6. For example, if the actual pump current I P exceeds the judgment level I P1 (point of A/F = λ L ), , the increase/decrease direction of the integrator up to that point is reversed, and as shown in FIG. 7a, the output of the air-fuel ratio sensor 2 passes through the stoichiometric air-fuel ratio λ 0 point, and then the air-fuel ratio control amount shown in FIG. 7b The integrator 32 operates so that A/F changes in the same direction, and a pump current I P1 where A/F=λ R is reached.
このＡ／Ｆ＝λRなるポンプ電流IPに達すると、
ただちに積分器３２の積分方向が反転し、空燃比
の制御量はリーン側に向つて変化してゆく。 When the pump current I P reaches this A/F=λ R ,
Immediately, the integration direction of the integrator 32 is reversed, and the controlled amount of the air-fuel ratio changes toward the lean side.
以上の動作を繰り返すことによつて、空燃比は
理論空燃比を中心としてλRとλLの幅の中で制御さ
れる。積分器３２の積分定数は機関の空燃比応答
時間に合せて適切な値に設定しておけば、実際の
空燃比は必らずλRとλL間にフイードバツク制御さ
れる。 By repeating the above operations, the air-fuel ratio is controlled within the range of λ R and λ L around the stoichiometric air-fuel ratio. If the integration constant of the integrator 32 is set to an appropriate value in accordance with the air-fuel ratio response time of the engine, the actual air-fuel ratio will always be feedback-controlled between λ R and λ L.
したがつて、従来装置にあつては理論空燃比λ0
点で出力が反転する酸素センサを用いて、見込み
の積分によつて空燃比を制御しているため、実際
の空燃比のリツプル値は機関の回転数などの運転
状態の影響を受けるのに対して、この発明では、
理論空燃比近傍の空燃比を空燃比センサによつて
直接検出し、この検出値にしたがつて空燃比がフ
イードバツク制御されるので、空燃比のリツプル
は機関の運転状態に影響されることなく、常にλR
とλLとの間に精度よく制御されるという効果があ
る。 Therefore, in the conventional device, the stoichiometric air-fuel ratio λ 0
Since the air-fuel ratio is controlled by integrating the expected value using an oxygen sensor whose output reverses at a certain point, the ripple value of the actual air-fuel ratio is affected by the engine speed and other operating conditions. In this invention,
The air-fuel ratio near the stoichiometric air-fuel ratio is directly detected by the air-fuel ratio sensor, and the air-fuel ratio is feedback-controlled according to this detected value, so the ripple in the air-fuel ratio is not affected by the engine operating condition. Always λ R
This has the effect of precisely controlling the relationship between and λ L .
なお、以上の説明において空燃比の制御手段と
して、積分器と混合気生成手段を用いたが、積分
器はコンデンサ、演算増幅器などを用いたアナロ
グ回路でもよいし、またマイクロコンピユータに
よるデイジタル式でもよく、混合気生成手段とし
ては燃料噴射装置やフイードバツク制御気化器を
用いることによつて上記の機能を果すことができ
る。 In the above explanation, an integrator and a mixture generating means are used as means for controlling the air-fuel ratio, but the integrator may be an analog circuit using a capacitor, an operational amplifier, etc., or may be a digital type using a microcomputer. The above function can be achieved by using a fuel injection device or a feedback control carburetor as the air-fuel mixture generating means.
以上のように、この発明の空燃比制御装置によ
れば、理論空燃比近傍の空燃比を空燃比センサに
よつて直接検出し、この検出値にしたがつて空燃
比をフイードバツク制御するようにしたので、正
確な理論空燃比は勿論のこと、それ以外の空燃比
をも正確に制御することができるものである。 As described above, according to the air-fuel ratio control device of the present invention, the air-fuel ratio near the stoichiometric air-fuel ratio is directly detected by the air-fuel ratio sensor, and the air-fuel ratio is feedback-controlled in accordance with this detected value. Therefore, not only the accurate stoichiometric air-fuel ratio but also other air-fuel ratios can be accurately controlled.
第１図は従来の空燃比制御装置の構成を示すブ
ロツク図、第２図は第１図の空燃比制御装置に用
いられる空燃比センサの特性図、第３図は第１図
の空燃比制御装置の動作を示す波形図、第４図は
この発明の空燃比制御装置の一実施例の構成を示
す図、第５図は第４図の−線の断面図、第６
図は第４図の空燃比制御装置に用いられる空燃比
センサの特性図、第７図は第４図の空燃比制御装
置における動作を示す波形図である。
１……排気管、２……空燃比センサ、３，７…
…イオン伝導性固体電解質、４，５，８，９……
白金電極、６……酸素ポンプ、１０……固体電解
質酸素センサ、１２……電子制御装置、３０……
電流電圧変換器、３１……比較器、３２……積分
器、３３……混合気生成手段、Ａ……演算増幅
器。なお、図中同一符号は同一または相当部分を
示す。
Fig. 1 is a block diagram showing the configuration of a conventional air-fuel ratio control device, Fig. 2 is a characteristic diagram of an air-fuel ratio sensor used in the air-fuel ratio control device shown in Fig. 1, and Fig. 3 is a diagram showing the air-fuel ratio control shown in Fig. 1. FIG. 4 is a waveform diagram showing the operation of the device; FIG. 4 is a diagram showing the configuration of an embodiment of the air-fuel ratio control device of the present invention; FIG.
4 is a characteristic diagram of an air-fuel ratio sensor used in the air-fuel ratio control device of FIG. 4, and FIG. 7 is a waveform diagram showing the operation of the air-fuel ratio control device of FIG. 4. 1... Exhaust pipe, 2... Air-fuel ratio sensor, 3, 7...
...Ion conductive solid electrolyte, 4, 5, 8, 9...
Platinum electrode, 6...Oxygen pump, 10...Solid electrolyte oxygen sensor, 12...Electronic control device, 30...
Current-voltage converter, 31... comparator, 32... integrator, 33... air-fuel mixture generation means, A... operational amplifier. Note that the same reference numerals in the figures indicate the same or corresponding parts.
Claims (1)
圧を制御する固体電解質酸素ポンプと、上記間隙
部内の酸素分圧と上記間隙部外の排気ガス中の酸
素分圧に対応した起電力を発生する固体電解質酸
素センサと、この固体電解質酸素センサが発生す
る起電力を所定値に保つように上記固体電解質酸
素ポンプのポンプ電流を制御し、上記ポンプ電流
が機関の空燃比に対して理論空燃比を中心にＶ字
形特性となるように上記所定値を設定し、上記ポ
ンプ電流に対応した信号を出力する電流制御手段
と、上記機関の燃料量または空気量を制御して上
記機関の空燃比を制御する第１の手段と、排気ガ
スを浄化する三元触媒装置と、上記電流制御手段
から上記ポンプ電流に対応する出力信号を入力
し、上記三元触媒装置の浄化率が最大となる上記
機関の空燃比に対応したポンプ電流値以下の範囲
内でリツチ側およびリーン側に交番するように上
記第１の手段をフイードバツク制御する第２の手
段とよりなることを特徴とする空燃比制御装置。1. A solid electrolyte oxygen pump that controls the oxygen partial pressure in the gap into which engine exhaust gas is introduced, and generates an electromotive force corresponding to the oxygen partial pressure in the gap and the oxygen partial pressure in the exhaust gas outside the gap. The pump current of the solid electrolyte oxygen pump is controlled so as to maintain the electromotive force generated by the solid electrolyte oxygen sensor at a predetermined value, and the pump current is set to a stoichiometric air-fuel ratio with respect to the air-fuel ratio of the engine. current control means for setting the predetermined value so as to have a V-shaped characteristic around the pump current and outputting a signal corresponding to the pump current; The engine includes a first means for controlling, a three-way catalyst device for purifying exhaust gas, and an output signal corresponding to the pump current from the current control means, so that the purification rate of the three-way catalyst device is maximized. an air-fuel ratio control device comprising: a second means for feedback-controlling the first means so as to alternate between rich and lean within a range equal to or less than a pump current value corresponding to an air-fuel ratio;
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58137113A JPS6027752A (en) | 1983-07-25 | 1983-07-25 | Air-fuel ratio controlling apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58137113A JPS6027752A (en) | 1983-07-25 | 1983-07-25 | Air-fuel ratio controlling apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6027752A JPS6027752A (en) | 1985-02-12 |
| JPH0315978B2 true JPH0315978B2 (en) | 1991-03-04 |
Family
ID=15191135
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58137113A Granted JPS6027752A (en) | 1983-07-25 | 1983-07-25 | Air-fuel ratio controlling apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6027752A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2772079B1 (en) * | 1997-12-08 | 2000-02-18 | Renault | METHOD AND DEVICE FOR CONTROLLING THE INJECTION OF AN INTERNAL COMBUSTION ENGINE |
-
1983
- 1983-07-25 JP JP58137113A patent/JPS6027752A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6027752A (en) | 1985-02-12 |
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