JPH0756229B2 - Air-fuel ratio controller - Google Patents
Air-fuel ratio controllerInfo
- Publication number
- JPH0756229B2 JPH0756229B2 JP60205522A JP20552285A JPH0756229B2 JP H0756229 B2 JPH0756229 B2 JP H0756229B2 JP 60205522 A JP60205522 A JP 60205522A JP 20552285 A JP20552285 A JP 20552285A JP H0756229 B2 JPH0756229 B2 JP H0756229B2
- Authority
- JP
- Japan
- Prior art keywords
- value
- air
- fuel ratio
- maximum value
- minimum value
- 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
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、自動車用内燃機関の空燃比制御装置に関する
ものである。Description: TECHNICAL FIELD The present invention relates to an air-fuel ratio control device for an internal combustion engine for automobiles.
［従来の技術］ 最近、自動車用内燃機関の有害排出ガスを減少させるた
めの一方法として、内燃機関の排出ガス成分に関する情
報によって空燃比を制御するフィードバック方式の空燃
比制御装置が提案されている。第３図は、例えば特開昭
53−82927号公報等で開示された空燃比制御装置のブロ
ック図である。図において、１は排気管中に設置された
O2センサ、２はバッファアンプ、３はO2センサ１の出力
のＰ−Ｐ値を算出する手段、４は求められたＰ−Ｐ値よ
り基準値を算出する手段、５は空燃比制御回路、６はア
クチュエータ駆動回路、７は電子制御気化器におけるエ
アブリードバルブあるいはエアリークバルブ等のアクチ
ュエータである。第４図は、第３図に示すＰ−Ｐ値算出
手段３、基準値算出手段４、および空燃比制御回路５の
具体的な回路を示す回路図であり、図において、31は極
小値保持用コンデンサ、32は極大値保持用コンデンサ、
33,34はコンデンサ31,32の充放電を行うダイオード、4
1,42は抵抗で、コンデンサ31,32に保持された極小値Vmi
nおよびVmaxに対応した電荷が放電される。43はバッフ
ァアンプで、基準電圧信号Vsを出力し、空燃比制御回路
５の作動増幅器に、O2センサ１のバッファアンプ２を介
した出力Vo2とともに入力される。[Prior Art] Recently, as one method for reducing harmful exhaust gas from an internal combustion engine for an automobile, a feedback type air-fuel ratio control device has been proposed which controls an air-fuel ratio based on information on exhaust gas components of the internal combustion engine. . FIG. 3 shows, for example,
FIG. 3 is a block diagram of an air-fuel ratio control device disclosed in Japanese Patent Publication No. 53-82927 or the like. In the figure, 1 is installed in the exhaust pipe
O 2 sensor, 2 is a buffer amplifier, 3 is means for calculating the PP value of the output of the O 2 sensor 1, 4 is means for calculating a reference value from the obtained PP value, and 5 is an air-fuel ratio control circuit. , 6 is an actuator drive circuit, and 7 is an actuator such as an air bleed valve or an air leak valve in the electronically controlled carburetor. FIG. 4 is a circuit diagram showing a specific circuit of the PP value calculating means 3, the reference value calculating means 4, and the air-fuel ratio control circuit 5 shown in FIG. 3, in which 31 is a minimum value holding. Capacitor, 32 is a capacitor for maintaining maximum value,
33 and 34 are diodes for charging and discharging the capacitors 31 and 32, 4
1,42 is a resistance, which is the minimum value Vmi held in the capacitors 31,32.
The charges corresponding to n and Vmax are discharged. Reference numeral 43 is a buffer amplifier which outputs the reference voltage signal Vs and is input to the operation amplifier of the air-fuel ratio control circuit 5 together with the output Vo 2 of the O 2 sensor 1 via the buffer amplifier 2.
このように構成された従来の空燃比制御装置において
は、O2センサ１からの出力信号Vo2と基準値Vsとを空燃
比制御回路５で比較し、その偏差に応じてアクチュエー
タ駆動回路６を介し、電子制御気化器のエアリークバル
ブ等のアクチュエータ７を駆動し、空燃比のフィードバ
ック制御を行う。このO2センサ１は、使用条件などによ
り出力特性が変化し、いわゆる経時劣化が生じるので、
その対策として、Ｐ−Ｐ値算出手段３で求めたＰ−Ｐ値
（VmaxとVminの夫々のピーク値）より、基準値算出手段
４において基準値Vsを算出し、O2センサ１の劣化に伴う
出力電圧Vo2の変化を補償するように構成されている。In the conventional air-fuel ratio control device configured as described above, the output signal Vo 2 from the O 2 sensor 1 and the reference value Vs are compared by the air-fuel ratio control circuit 5, and the actuator drive circuit 6 is set according to the deviation. The actuator 7 such as the air leak valve of the electronically controlled carburetor is driven through the feedback control of the air-fuel ratio. Since the output characteristics of the O 2 sensor 1 change depending on the usage conditions and so-called deterioration with time occurs,
As a countermeasure, the reference value Vs is calculated by the reference value calculation unit 4 from the P-P value (each peak value of Vmax and Vmin) obtained by the P-P value calculation unit 3 to prevent the deterioration of the O 2 sensor 1. It is configured to compensate for the accompanying change in output voltage Vo 2 .
［発明が解決しようとする問題点］ 上記のように構成された従来の空燃比制御装置におい
て、O2センサ１は内部抵抗が比較的に高く、また当然の
ことながらエンジンの近くに設置されているので、イグ
ニッション・ノイズ等が混入しやすい傾向にある。この
ノイズ混入時の動作を、O2センサ１の出力信号Vo2、Ｐ
−Ｐ値算出手段３で算出されるVmaxであるVpeak、およ
び基準信号Vsとの関係で示すと、第５図のようになり、
混入したノイズにより、Ｐ−Ｐ値算出手段３の極大値保
持用コンデンサ32がチャージされ、Vpeak値は電圧が上
昇したまま、コンデンサ32の電荷が放電されるまでの
間、本来のO2センサ１の出力信号Vo2よりも著しく高い
電圧状態が継続する。従って、基準値Vsも、本来あるべ
きレベルVs′よりずれが生じ、正しい空燃比のフィード
バック制御が行えず、排出ガスの浄化率が低下するなど
の不都合があった。このため、第６図に示すように、基
準値算出手段４に、ダイオード44および抵抗46,47から
なる上限リミッタ、ダイオード45および抵抗48,49から
なる上限リミッタを設ける方法も開示されているが、第
７図の波形で示すように、基準値Vsのずれをある程度お
さえ込むことは可能であるが、ずれが生じている時間は
短縮されないという問題があった。[Problems to be Solved by the Invention] In the conventional air-fuel ratio control device configured as described above, the O 2 sensor 1 has a relatively high internal resistance, and as a matter of course, it is installed near the engine. As a result, ignition noise and the like tend to be easily mixed. The operation when the noise is mixed is performed by the output signal Vo 2 , P of the O 2 sensor 1.
The relationship between Vpeak, which is Vmax calculated by the P value calculating means 3, and the reference signal Vs is as shown in FIG.
Due to the mixed noise, the maximum value holding capacitor 32 of the P-P value calculation means 3 is charged, and the original O 2 sensor 1 is charged until the electric charge of the capacitor 32 is discharged while the Vpeak value is still increasing. The voltage state that is significantly higher than the output signal Vo 2 of continues. Therefore, the reference value Vs also deviates from the originally expected level Vs', the correct feedback control of the air-fuel ratio cannot be performed, and the purification rate of exhaust gas is lowered. Therefore, as shown in FIG. 6, a method of providing the reference value calculating means 4 with an upper limit limiter including the diode 44 and the resistors 46 and 47 and an upper limit limiter including the diode 45 and the resistors 48 and 49 is also disclosed. As shown by the waveform in FIG. 7, it is possible to suppress the deviation of the reference value Vs to some extent, but there is a problem that the time during which the deviation occurs is not shortened.
本発明は、上記のような問題点を解消するためになされ
たもので、外来ノイズの混入が生じても、排気ガス浄化
率の悪化を最小限に抑えることができる空燃比制御装置
を提供することを目的とする。The present invention has been made to solve the above problems, and provides an air-fuel ratio control device capable of minimizing deterioration of the exhaust gas purification rate even when external noise is mixed. The purpose is to
［問題点を解決するための手段］ この目的のため本発明による空燃比制御装置は、エンジ
ンの排気ガス成分濃度を検出する排気センサと、この排
気センサの出力を入力する入力手段と、この入力手段を
介して入力した上記排気センサの出力の極大値および極
小値を検出する極大値・極小値算出手段と、この極大値
・極小値算出手段により検出された極大値または極小値
の少なくとも一方から基準値を決定する基準値算出手段
とを備え、上記排気センサの出力と上記基準値算出手段
により決定された基準値との偏差に基づいた制御信号に
より燃料調量装置を制御する空燃比制御装置において、
上記入力手段には、上記排気センサ出力の極大値の最大
値を制限する上限値または極小値の最小値を制限する下
限値の少なくとも一方を設けたことを手段としている。[Means for Solving the Problems] For this purpose, the air-fuel ratio control apparatus according to the present invention is an exhaust gas sensor for detecting the exhaust gas component concentration of an engine, an input means for inputting the output of this exhaust gas sensor, and this input. From the maximum value / minimum value calculating means for detecting the maximum value and the minimum value of the output of the exhaust sensor input via the means, and at least one of the maximum value or the minimum value detected by the maximum / minimum value calculating means. An air-fuel ratio control device comprising a reference value calculating means for determining a reference value, and controlling the fuel metering device by a control signal based on a deviation between the output of the exhaust sensor and the reference value determined by the reference value calculating means. At
The input means is provided with at least one of an upper limit value for limiting the maximum value of the maximum value of the exhaust sensor output and a lower limit value for limiting the minimum value of the minimum value.
［作用］ 本発明による空燃比制御装置では、排気センサ出力信号
にノイズが混入し、その出力信号が異常に高くなって
も、定電圧ダイオードによって設定される所定の上限値
および下限値の少なくとも一方によって規制し、ノイズ
による基準信号のずれを最小限に抑えて、空燃比のフィ
ードバック制御の誤動作を防止する。[Operation] In the air-fuel ratio control device according to the present invention, even if noise is mixed in the exhaust sensor output signal and the output signal becomes abnormally high, at least one of the predetermined upper limit value and lower limit value set by the constant voltage diode. The control of the air-fuel ratio is prevented by controlling the deviation of the reference signal due to noise to the minimum.
［実施例］ 第１図は本発明の一実施例を示す空燃比制御装置の回路
図であり、図において、１は排出ガス管路内に設けられ
たO2センサ、２は入力手段、20はバッファアンプ、21は
下限値規制用の定電圧ダイオード、22は上限値規制用の
定電圧ダイオード、３は極大値・極小値算出手段である
Ｐ−Ｐ値算出手段、31は極小値保持用コンデンサ、32は
極大値保持用コンデンサ、33,34はコンデンサ31,32の充
放電を行うダイオード、４は基準値算出手段、41,42は
抵抗で、コンデンサ31,32に保持された極小値Vminおよ
び極大値Vmaxに対応した電荷が放電され基準値が決定さ
れる。43はバッファアンプで、基準値にもとづいて基準
電圧信号Vsを出力する。５は空燃比制御回路、６はアク
チュエータ駆動回路、７は電子制御気化器におけるエア
ブリードバルブあるいはエアリークバルブのアクチュエ
ータである。[Embodiment] FIG. 1 is a circuit diagram of an air-fuel ratio control apparatus showing an embodiment of the present invention. In the drawing, 1 is an O 2 sensor provided in an exhaust gas pipeline, 2 is an input means, and 20 is an input means. Is a buffer amplifier, 21 is a constant voltage diode for regulating the lower limit value, 22 is a constant voltage diode for regulating the upper limit value, 3 is a PP value calculating means for calculating maximum / minimum values, and 31 is for holding the minimum value. A capacitor, 32 is a capacitor for holding the maximum value, 33, 34 are diodes for charging and discharging the capacitors 31, 32, 4 is a reference value calculating means, 41, 42 are resistors, and the minimum value Vmin held in the capacitors 31, 32. And the electric charge corresponding to the maximum value Vmax is discharged and the reference value is determined. A buffer amplifier 43 outputs a reference voltage signal Vs based on the reference value. Reference numeral 5 is an air-fuel ratio control circuit, 6 is an actuator drive circuit, and 7 is an actuator for an air bleed valve or an air leak valve in an electronically controlled carburetor.
上記のように構成された本発明の装置においては、O2セ
ンサ１からの出力信号Vo2は、バッファアンプ20で増幅
されて、Ｐ−Ｐ値（極小値および極大値）算出手段３お
よび空燃比制御回路４に入力される。Ｐ−Ｐ値算出手段
３では、入力される出力信号Vo2の極小値Vminおよび極
大値Vmaxを、ダイオード33,34を介してそれぞれ極小値
保持用コンデンサ31および極大値保持用コンデンサ32に
充電電荷として保持する。この両コンデンサ31,32に保
持された電荷は、基準値算出手段４の抵抗41,42を通し
て放電され、バッファアンプ43より基準電圧Vsとして出
力される。この基準値電圧Vsは、O2センサ１の経時劣化
による特性変化が補償されて、空燃比のリッチ・リーン
を判定するスライスレべルとなる。ところで、O2センサ
１は、内部抵抗が比較的高く、またエンジンの近くに設
置されているので、イグニッション等のノイズが混入し
易い傾向にあり、ノイズが混入すると、先に述べたよう
に、本来あるべき基準値Vsのレベルがずれて、誤った空
燃比のフィードバック制御が行われることになる。そこ
で、入力手段３のバッファアンプ20の出力側に、最小値
規制用電圧ダイオード21および最大値規制用定電圧ダイ
オード22を接続し、O2センサ１のバッファアンプ20を介
した出力信号Vo2の最小値および最大値をそれぞれ規制
し、ノイズ混入による出力信号Vo2の異常上昇を抑え
る。このノイズ混入時の動作を、第２図に示す波形図に
よって説明する。O2センサ１の出力Vo2は、リッチ・リ
ーンをサイクリックに繰返しており、Ｐ−Ｐ値算出手段
３、基準値算出手段４を経て出力される基準値Vsで空燃
比制御回路５の作動増幅器においてリッチ・リーンを判
定されるが、ノイズが混入すると、バッファアンプ20の
入力はこのノイズにより上昇するが、バッファアンプ20
の出力は定電圧ダイオード22によって規制され、Vo2・m
axまでしか上昇しない。従って、信号Vo2の極大値Vmax
であるVpeakも僅かに上昇するだけで直ぐ正常レベルに
復帰するので、基準信号Vsはほとんど変化せず、空燃比
制御回路５はたとえノイズが混入されても正常な空燃比
のフィードバック制御を継続することができる。In the apparatus of the present invention configured as described above, the output signal Vo 2 from the O 2 sensor 1 is amplified by the buffer amplifier 20, and the PP value (minimum value and maximum value) calculating means 3 and the empty value are calculated. It is input to the fuel ratio control circuit 4. The P-P value calculating means 3 charges the minimum value Vmin and the maximum value Vmax of the input output signal Vo 2 to the minimum value holding capacitor 31 and the maximum value holding capacitor 32 via the diodes 33 and 34, respectively. Hold as. The charges held in the capacitors 31 and 32 are discharged through the resistors 41 and 42 of the reference value calculating means 4 and output from the buffer amplifier 43 as the reference voltage Vs. This reference value voltage Vs becomes a slice level for determining the rich / lean of the air-fuel ratio by compensating for the characteristic change due to the deterioration of the O 2 sensor 1 with time. By the way, since the O 2 sensor 1 has a relatively high internal resistance and is installed in the vicinity of the engine, noise such as ignition tends to be mixed in. When noise is mixed, as described above, The level of the reference value Vs, which should be supposed to be, is deviated, and incorrect feedback control of the air-fuel ratio is performed. Therefore, the minimum value regulating voltage diode 21 and the maximum value regulating constant voltage diode 22 are connected to the output side of the buffer amplifier 20 of the input means 3 to output the output signal Vo 2 via the buffer amplifier 20 of the O 2 sensor 1. The minimum value and the maximum value are regulated respectively to suppress an abnormal rise in the output signal Vo 2 due to noise mixing. The operation when this noise is mixed will be described with reference to the waveform chart shown in FIG. The output Vo 2 of the O 2 sensor 1 is cyclically rich and lean, and the air-fuel ratio control circuit 5 operates at the reference value Vs output through the PP value calculating means 3 and the reference value calculating means 4. Although rich lean is judged in the amplifier, if noise is mixed, the input of the buffer amplifier 20 rises due to this noise.
The output of is regulated by the constant voltage diode 22, Vo 2
Only rises to ax. Therefore, the maximum value Vmax of the signal Vo 2
Vpeak, which is a slight increase, immediately returns to the normal level, so the reference signal Vs hardly changes, and the air-fuel ratio control circuit 5 continues the normal feedback control of the air-fuel ratio even if noise is mixed. be able to.
なお、上記実施例ではアナログ回路として説明したが、
デイジタル回路あるいはコンピュータのソフトウエア等
で構成してもよく、同様な効果を奏する。Although the above embodiment has been described as an analog circuit,
It may be constituted by a digital circuit or computer software, etc., and has the same effect.
［発明の効果］ 以上説明したとおり本発明によれば、排気センサの出力
に例えばノイズ等の過大電圧が混入した場合でも、入力
手段が極大値・極小値算出手段が出力する排気センサ出
力の極大値は、上限値によって最大値が制限されるの
で、極大値・極小値算出手段が検出する極大値も最大値
が制限されるのであり、基準値算出手段が決定する基準
値は、本来の基準値から大幅にズレることなく、しかも
迅速に本来の基準値に復帰する。従って、ノイズの影響
を最小限に抑えて排気ガス浄化効率の高い空燃比制御を
行うことができ、この空燃比制御を一旦停止することな
く継続して行うことができる。[Effects of the Invention] As described above, according to the present invention, even if an excessive voltage such as noise is mixed in the output of the exhaust sensor, the maximum of the exhaust sensor output that the input means outputs by the maximum value / minimum value calculation means. Since the maximum value is limited by the upper limit value, the maximum value detected by the maximum value / minimum value calculating means is also limited, and the reference value determined by the reference value calculating means is the original reference value. It recovers to the original reference value quickly without being significantly deviated from the value. Therefore, the influence of noise can be minimized to perform the air-fuel ratio control with high exhaust gas purification efficiency, and the air-fuel ratio control can be continuously performed without being temporarily stopped.
第１図は本発明の一実施例を示す空燃比制御装置の回路
図、第２図は第１図における波形図、第３図は従来の空
燃比制御装置のブロック図、第４図は第３図の具体的回
路図、第５図は第４図における波形図、第６図はノイズ
対策を有する従来の空燃比制御装置の回路図、第７図は
第６図における波形図である。 １……O2センサ、２……入力手段、20……バッファアン
プ、21……下限値規制用定電圧ダイオード、22……上限
値規制用定電圧ダイオード、３……Ｐ−Ｐ値算出手段、
４……基準値算出手段、５……空燃比制御回路。FIG. 1 is a circuit diagram of an air-fuel ratio control device showing an embodiment of the present invention, FIG. 2 is a waveform diagram in FIG. 1, FIG. 3 is a block diagram of a conventional air-fuel ratio control device, and FIG. 3 is a specific circuit diagram, FIG. 5 is a waveform diagram in FIG. 4, FIG. 6 is a circuit diagram of a conventional air-fuel ratio control device having a noise countermeasure, and FIG. 7 is a waveform diagram in FIG. 1 ... O 2 sensor, 2 ... input means, 20 ... buffer amplifier, 21 ... lower limit value constant voltage diode, 22 ... upper limit value constant voltage diode, 3 ... PP value calculating means ,
4 ... Reference value calculating means, 5 ... Air-fuel ratio control circuit.
Claims (1)
気センサと、この排気センサの出力を入力する入力手段
と、この入力手段を介して入力した上記排気センサの出
力の極大値および極小値を検出する極大値・極小値算出
手段と、この極大値・極小値算出手段により検出された
極大値または極小値の少なくとも一方から基準値を決定
する基準値算出手段とを備え、上記排気センサの出力と
上記基準値算出手段により決定された基準値との偏差に
基づいた制御信号により燃料調量装置を制御する空燃比
制御装置において、 上記入力手段には、上記排気センサ出力の極大値の最大
値を制限する上限値または極小値の最小値を制限する下
限値の少なくとも一方を設け、 上記入力手段にて最大値または最小値が制限された排気
センサ出力の極大値または極小値に基づき空燃比制御を
継続することを特徴とする空燃比制御装置。1. An exhaust sensor for detecting an exhaust gas component concentration of an engine, an input means for inputting an output of the exhaust sensor, and a maximum value and a minimum value of the output of the exhaust sensor input via the input means. The maximum value / minimum value calculating means for detecting and the reference value calculating means for determining a reference value from at least one of the maximum value and the minimum value detected by the maximum value / minimum value calculating means are provided. And an air-fuel ratio control device for controlling the fuel metering device by a control signal based on a deviation from the reference value determined by the reference value calculation means, wherein the input means has the maximum value of the maximum value of the exhaust sensor output. The maximum value of the exhaust sensor output is limited to the upper limit value or the minimum value to limit the minimum value, and the maximum value or the minimum value is limited by the input means. Other air-fuel ratio control apparatus characterized by continuing the air-fuel ratio control on the basis of the minimum value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60205522A JPH0756229B2 (en) | 1985-09-18 | 1985-09-18 | Air-fuel ratio controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60205522A JPH0756229B2 (en) | 1985-09-18 | 1985-09-18 | Air-fuel ratio controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6267254A JPS6267254A (en) | 1987-03-26 |
| JPH0756229B2 true JPH0756229B2 (en) | 1995-06-14 |
Family
ID=16508271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60205522A Expired - Lifetime JPH0756229B2 (en) | 1985-09-18 | 1985-09-18 | Air-fuel ratio controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756229B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0649873Y2 (en) * | 1987-05-19 | 1994-12-14 | マツダ株式会社 | Air-fuel ratio detector for engine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5297025A (en) * | 1976-02-09 | 1977-08-15 | Nissan Motor Co Ltd | Air fuel ration controller |
-
1985
- 1985-09-18 JP JP60205522A patent/JPH0756229B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6267254A (en) | 1987-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4178883A (en) | Method and apparatus for fuel/air mixture adjustment | |
| US4252098A (en) | Air/fuel ratio control for an internal combustion engine using an exhaust gas sensor | |
| US4167925A (en) | Closed loop system equipped with a device for producing a reference signal in accordance with the output signal of a gas sensor for internal combustion engine | |
| US4501240A (en) | Idling speed control system for internal combustion engine | |
| US4359029A (en) | Air/fuel ratio control system for an internal combustion engine | |
| EP0517291A1 (en) | Method and apparatus for controlling and diagnosing a fuel system | |
| US4171690A (en) | Emission control system for internal combustion engines utilizing balance differential amplifier stage | |
| US3984976A (en) | Air-fuel ratio control system for automotive engine with compensation circuit for deterioration of feedback signal generator | |
| EP0087809A2 (en) | Electrical fuel injector control | |
| KR970011035B1 (en) | Ignition timing control unit for internal combustion engine | |
| US4526148A (en) | Air-fuel ratio control system for an internal combustion engine | |
| JPH0756229B2 (en) | Air-fuel ratio controller | |
| KR940004342B1 (en) | Method and device for controlling air-fuel ratio | |
| US4204482A (en) | Comparator circuit adapted for use in a system for controlling the air-fuel ratio of an internal combustion engine | |
| US4182300A (en) | Trouble warning device for an air-fuel ratio sensor | |
| JPS59190433A (en) | Idle rotation control device of engiene | |
| JPH0756228B2 (en) | Air-fuel ratio controller | |
| US5381656A (en) | Engine air/fuel control system with catalytic converter monitoring | |
| JP2806501B2 (en) | Engine air-fuel ratio control device | |
| KR0154019B1 (en) | Air/fuel ratio control device and method of engin state | |
| US4413471A (en) | Air-fuel ratio control apparatus of an internal combustion engine | |
| JPS58176436A (en) | Control device for engine | |
| JPS6313012B2 (en) | ||
| JPS6254973B2 (en) | ||
| JPH03189350A (en) | Heater control unit for oxygen sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |