JPS58143108A - Air-fuel ratio control method for internal-combustion engine - Google Patents
Air-fuel ratio control method for internal-combustion engineInfo
- Publication number
- JPS58143108A JPS58143108A JP57024345A JP2434582A JPS58143108A JP S58143108 A JPS58143108 A JP S58143108A JP 57024345 A JP57024345 A JP 57024345A JP 2434582 A JP2434582 A JP 2434582A JP S58143108 A JPS58143108 A JP S58143108A
- Authority
- JP
- Japan
- Prior art keywords
- fuel ratio
- air
- output
- fuel
- oxygen sensor
- 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.)
- Granted
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
- F02D41/1493—Details
- F02D41/1496—Measurement of the conductivity of a sensor
Abstract
Description
【発明の詳細な説明】
本発明は、排気系の酸素センナの出力を帰還信号として
用いて吸気系への燃料あるいは空気の供給量を制御する
内燃機関の空燃比制御方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air-fuel ratio control method for an internal combustion engine that uses the output of an oxygen sensor in an exhaust system as a feedback signal to control the amount of fuel or air supplied to an intake system.
はぼ理論空燃比を検出する場合には酸素センサへの定電
圧の印加を中止して酸素センサを電圧出力として作動さ
せ、また、理論空燃比より大きい空燃比、すなわち希薄
空燃比領域における酸素濃度を検出する場合には酸素セ
ンサへ定電圧を印加して酸素センサを電流出力として作
動させることは、本出願人が先願においてすでに開示し
ている。When detecting the stoichiometric air-fuel ratio, the application of a constant voltage to the oxygen sensor is stopped and the oxygen sensor is operated as a voltage output. The present applicant has already disclosed in a previous application that when detecting oxygen, a constant voltage is applied to the oxygen sensor and the oxygen sensor is operated as a current output.
本発明の目的は排気系の酸素センサの出力喉才゛を
態詐切換えて空燃比を適切に制御することができる内燃
機関の空燃比制御方法を提供することである。An object of the present invention is to provide an air-fuel ratio control method for an internal combustion engine that can appropriately control the air-fuel ratio by changing the output power of an oxygen sensor in the exhaust system.
この目的を達成するために本発明では、車両の運転状態
に関係して酸素センサを電流出力あるいは電圧出力とし
て作動させる。すなわち本発明によれば、酸素センナが
、定電圧を印加されている場合には排気系の酸素濃度に
関係する出力電流を発生し、定電圧の印加を中止されて
いる場合にはほぼ理論空燃比を境にして出力電圧レベル
を反転し、このような酸素センサの出力を帰還信号とし
て用いる内燃機関の空燃比制御方法において、車両の運
転状態に関係して目標空燃比を設定し、目標空燃比に関
係して酸素センサへの定電圧の印加を制御し、目標空燃
比と酸素センサからの帰還空燃比を比較して吸気系への
燃料あるいは空気の供給量を増減する。To achieve this objective, the invention operates the oxygen sensor as a current output or as a voltage output depending on the operating state of the vehicle. That is, according to the present invention, the oxygen sensor generates an output current related to the oxygen concentration in the exhaust system when a constant voltage is applied, and generates an output current related to the oxygen concentration in the exhaust system when the constant voltage is not applied. In an air-fuel ratio control method for an internal combustion engine in which the output voltage level is inverted based on the fuel ratio and the output of such an oxygen sensor is used as a feedback signal, a target air-fuel ratio is set in relation to the operating state of the vehicle. The application of a constant voltage to the oxygen sensor is controlled in relation to the fuel ratio, and the target air-fuel ratio is compared with the feedback air-fuel ratio from the oxygen sensor to increase or decrease the amount of fuel or air supplied to the intake system.
好ましい実施態様によれば、目標空燃比に対応する酸素
センサ出力を求め、この対応出力と酸素センサの出力と
を比較して吸気系への燃料あるいは空気供給量を増減す
る。According to a preferred embodiment, the oxygen sensor output corresponding to the target air-fuel ratio is determined and the corresponding output is compared with the output of the oxygen sensor to increase or decrease the amount of fuel or air supplied to the intake system.
例えば、加速期間では酸素センサを電圧出力として作動
させ、アイドリンク期間および定常走行期間では酸素セ
ンサを電流出力として作動させる。For example, during an acceleration period, the oxygen sensor is operated as a voltage output, and during an idle period and a steady running period, the oxygen sensor is operated as a current output.
図面を参照して本発明の詳細な説明する。The present invention will be described in detail with reference to the drawings.
第１図において、０２センサ（酸素センサ）１は、その
検出素子２が酸素イオン伝導性の安定化ジルコニア固体
電解質で構成されており、Ｕ字状に形成されている検出
素子２０両面には、陰極３と陽極４との電極が形成され
ている。そして、陰極３の上面５は、排気ガス中の酸素
濃度の拡散を制御する機能を有する多孔質（ポーラス）
セラミック層により被覆されている。また、Ｕ字状に形
成された陽極４に沿って大気を吸入するための人嫌吸入
管６が設けられている。In FIG. 1, the 02 sensor (oxygen sensor) 1 has a detection element 2 made of a stabilized zirconia solid electrolyte that conducts oxygen ions, and has U-shaped detection elements 20 on both sides. Electrodes including a cathode 3 and an anode 4 are formed. The upper surface 5 of the cathode 3 is porous, which has a function of controlling the diffusion of oxygen concentration in the exhaust gas.
Covered with a ceramic layer. Further, a human-resistant suction pipe 6 for inhaling atmospheric air is provided along the U-shaped anode 4.
また、さらに、Ｕ字型に形成されている大気吸入管６の
間隙７にはセラミックヒータ８が設けられている。セラ
ミックヒータ８は後述の温度調整器に接続され、検出素
子２の先端部９を所定の温度、例えば６５０〜７００℃
以上に加熱し、検出素子２の酸素ポンプ作用を機能させ
るために設けられている。また、０２センサ１は、大気
１１が基準極となるように、陽極４が大気吸入管６に吸
入される大気と接触するようにし、陽極４が排気ガス１
２と接触しないように充分気密性のある構造とされてい
る。０２センサ１の陰極３と陽極４はそれぞれリード線
１３ 、１４を介して印加電圧切換装置１５に接続され
ている。Furthermore, a ceramic heater 8 is provided in the gap 7 of the U-shaped atmosphere suction pipe 6. The ceramic heater 8 is connected to a temperature regulator to be described later, and controls the tip 9 of the detection element 2 to a predetermined temperature, for example, 650 to 700°C.
It is provided in order to heat the detection element 2 to a higher level and make the oxygen pumping action of the detection element 2 function. In addition, the 02 sensor 1 is configured such that the anode 4 is in contact with the atmosphere sucked into the atmosphere suction pipe 6 so that the atmosphere 11 serves as a reference electrode, and the anode 4 is in contact with the atmosphere sucked into the exhaust gas 1.
The structure is sufficiently airtight to prevent contact with 2. The cathode 3 and anode 4 of the 02 sensor 1 are connected to an applied voltage switching device 15 via lead wires 13 and 14, respectively.
印加電圧切換装置１５は、電源Ｖ、抵抗Ｒ１３極スイッ
チ１６で構成されており、後述する制御部のＯＮ指令に
より、図示の如く３極スイツチ１６の接点Ａ−Ｂ、 Ｄ
−Ｅ、 Ｆ−Ｇが接続されると、陰極と陽極４間には抵
抗Ｒを介して電源Ｖの電源が印加される。陰極３と陽極
４間に印加される電圧は、検出素子２がセラミックヒー
タ８により６５０℃〜７００℃以上に加熱された状態で
、大気側の陽極４と排気ガス側の陰極３に限界電流が生
じるような電圧であり、例えば０．５〜１．０Ｖ程度の
電圧である。このような０２センサ１の陰極３と陽極４
間に所定の電圧が印加されると、検出素子２の酸素ポン
プ作用により排気ガス中の酸素濃度に対応した電流が抵
抗Ｒを介して流れる。この電流は出力端子１７ 、１８
から検出することができる。The applied voltage switching device 15 is composed of a power source V, a resistor R1, and a 3-pole switch 16. Contacts A-B and D of the 3-pole switch 16 are switched as shown in the figure by an ON command from a control section, which will be described later.
When -E and FG are connected, a power source V is applied between the cathode and the anode 4 via the resistor R. The voltage applied between the cathode 3 and the anode 4 is such that when the detection element 2 is heated to 650°C to 700°C or higher by the ceramic heater 8, there is a limiting current between the anode 4 on the atmosphere side and the cathode 3 on the exhaust gas side. This is a voltage that occurs, for example, about 0.5 to 1.0V. The cathode 3 and anode 4 of such 02 sensor 1
When a predetermined voltage is applied between them, a current corresponding to the oxygen concentration in the exhaust gas flows through the resistor R due to the oxygen pumping action of the detection element 2. This current flows through output terminals 17, 18
It can be detected from
この電流は、第２図の（ａ）に示される如く、空燃比が
理論空燃比よりもリーン側となったとき、すなわち燃料
リーンでの空燃比域では酸素濃度に対応した値で変化す
る。As shown in FIG. 2(a), this current changes at a value corresponding to the oxygen concentration when the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, that is, in the lean air-fuel ratio range.
そのため、この電流を燃料リーン空燃比域における目標
空燃比として用いることにより、燃料リーンでの空燃比
を制御することが可能となる。Therefore, by using this current as the target air-fuel ratio in the fuel-lean air-fuel ratio range, it becomes possible to control the air-fuel ratio in the fuel-lean state.
一方、制御部からのＯＦＦ指令により３極スイツチ１６
の接点が切換わり、接点Ａ−Ｃ，Ｄ−Ｃ１Ｆ−Ｈが接続
されると、陰極３と陽極４には電源が供給されなくなる
。この場合、出力端子１７゜１８からは、第２図の（ｂ
）に示される如く、従来の０２センサと同様理論空燃比
近傍で出力電圧レベルが反転するＯＮ −ＯＦＦ特性を
有する信号が出力される。On the other hand, the 3-pole switch 16 is turned off by an OFF command from the control unit.
When the contacts A-C, D-C1F-H are connected, power is no longer supplied to the cathode 3 and anode 4. In this case, from the output terminal 17°18, (b
), similar to the conventional 02 sensor, a signal having an ON-OFF characteristic in which the output voltage level is reversed near the stoichiometric air-fuel ratio is output.
したがって、印加電圧切換装置１５の３極スイツチ１６
を、図示の状態から切換えることにより理論空燃比（−
おける帰還制御が可能となる。Therefore, the three-pole switch 16 of the applied voltage switching device 15
By switching from the state shown in the figure, the stoichiometric air-fuel ratio (-
Feedback control is now possible.
第３図には、第１図に示されている０２センサおよび印
加電圧切換装置１５を含む内燃機関の空燃比制御装置の
全体構成図が示されている。FIG. 3 shows an overall configuration diagram of an air-fuel ratio control device for an internal combustion engine including the 02 sensor and applied voltage switching device 15 shown in FIG.
本実施例における空燃比制御装置は、車両の機能に関す
る各種の情報を検出するセンサ群２０、制御部２２、お
よび燃料供給装置２４で構成されており、センサ群２０
からの検出信号に応じて、インジェクタ等を含む燃料噴
射式の燃料供給装置２４を制御部２２によって帰還制御
することができる。The air-fuel ratio control device in this embodiment is composed of a sensor group 20 that detects various information regarding the functions of the vehicle, a control section 22, and a fuel supply device 24.
According to the detection signal from the control unit 22, the fuel injection type fuel supply device 24 including an injector and the like can be feedback-controlled.
センサ群２０には、前述した０２センサ１が含まれると
ともに、吸気管負圧を検出する吸気管センサ２６、エン
ジン冷却水温を検出する冷却水温センナ２８、エンジン
回転速度を検出する回転速度センナ３０、スロットルバ
ルブの開閉状態を検出するスロットルセンナ３２等が含
まれる。センサ群２０の各センサの検出信号は制御部２
２に供給される。The sensor group 20 includes the above-mentioned 02 sensor 1, as well as an intake pipe sensor 26 that detects intake pipe negative pressure, a coolant temperature sensor 28 that detects engine coolant temperature, and a rotation speed sensor 30 that detects engine rotation speed. A throttle sensor 32 and the like that detect the open/closed state of the throttle valve are included. The detection signal of each sensor in the sensor group 20 is sent to the control unit 2.
2.
印加電圧切換装置１５を含む制御部２２は、温度調整器
４０、増幅器４２、アナログマルチプレクサ４４、アナ
ログデジタル変換器（以下Ａ／Ｄ変換器と称する）４６
、ＣＰＵ４８、ＲＯＭ ５０、ＲＡＭ ５２、Ｉ／Ｆ５
４．５６等によって構成されている。The control unit 22 including the applied voltage switching device 15 includes a temperature regulator 40, an amplifier 42, an analog multiplexer 44, and an analog-to-digital converter (hereinafter referred to as an A/D converter) 46.
, CPU48, ROM 50, RAM 52, I/F5
4.56 etc.
増幅器４２は０２センサ１の出力信号を所定値に増幅す
る増幅器であり、０２センサ１の出力信号は増幅器４２
を介してアナログマルチプレクサ４４に供給される。ア
ナログマルチプレクサ４４には吸気管センサ２６、冷却
水温センサ２８の検出信号等の各種アナログ信号が供給
される。これらのアナログ信号は、コントロールバス５
８を介してＣＰＵ４８から与えられる制御信号により時
分割的にＡ／Ｄ変換器４６に送り込まれ順次デジタル信
号（＝伝速されるとデジタル量のデータとしてアドレス
データバス６０を介してＣＰＵ４８へ供給される。The amplifier 42 is an amplifier that amplifies the output signal of the 02 sensor 1 to a predetermined value.
is supplied to analog multiplexer 44 via. Various analog signals such as detection signals from the intake pipe sensor 26 and the cooling water temperature sensor 28 are supplied to the analog multiplexer 44 . These analog signals are connected to control bus 5.
8 are sent to the A/D converter 46 in a time-division manner according to a control signal given from the CPU 48, and when they are transmitted sequentially as digital signals, they are supplied to the CPU 48 as digital data via the address data bus 60. Ru.
ＣＰｏ ４８はこのデータに基づいて各種の演算を行な
う。CPo 48 performs various calculations based on this data.
また、回転速度センサ３０、スロットルセンサ３２の検
出信号Ｉ／Ｆ ５４を介して、回転速度データ、スロッ
トル弁の開閉状態を示すデータとしてＣＰＵ ４８へ供
給される。Further, the detection signals of the rotational speed sensor 30 and the throttle sensor 32 are supplied to the CPU 48 as rotational speed data and data indicating the opening/closing state of the throttle valve.
ＣＰＵ４８はセンサ群２０の各種センサからのデータを
取り込み、所定のプログラムに基づいた演算を行ない、
演算結果をＩ／Ｆ５６に供給する。Ｉ／Ｆ５６からは、
演算結果に基づいた制御信号が印加電圧切換装置１５、
温度調整器４０、増幅器４２、燃料供給装置２４へ供給
される。The CPU 48 takes in data from various sensors in the sensor group 20, performs calculations based on a predetermined program,
The calculation result is supplied to the I/F 56. From I/F56,
A control signal based on the calculation result is applied to the applied voltage switching device 15,
It is supplied to a temperature regulator 40, an amplifier 42, and a fuel supply device 24.
ＲＯＭ５０およびＲＡＭ ５２からなるメモリ部には、
第２図の（ａ）、（ｂ）に示される如く、０２センサ１
の検出信号に基づいて機関を理論空燃比または燃料リー
ン空燃比域における目標空燃比制御するためのデータ、
および装置の制御プログラム等が予め格納されている。The memory section consists of ROM50 and RAM52,
As shown in FIG. 2 (a) and (b), 02 sensor 1
data for controlling the target air-fuel ratio of the engine in the stoichiometric air-fuel ratio or fuel-lean air-fuel ratio range based on the detection signal of
and a control program for the device are stored in advance.
また、さらに、・吸気管センサ２ｄ、冷却水温センサ２
８、回転速度センサ３０、スロットルセンサ３２の検出
信号により機関を理論空燃比または燃料希薄空燃比域に
おける目標空燃比で制御するためのデータが予め格納さ
れている。Furthermore, the intake pipe sensor 2d, the cooling water temperature sensor 2
8. Data for controlling the engine at a stoichiometric air-fuel ratio or a target air-fuel ratio in a fuel lean air-fuel ratio region based on detection signals from the rotational speed sensor 30 and throttle sensor 32 is stored in advance.
第４図は本発明の制御ブロック図である。ステップ６１
で車両の運転状態が検出され、この運転状態に基づいて
ステップ６２で目標空燃比が設定される。ステップ６３
では目標空燃比に対応する０２センサ出力を求め、これ
を基準値とする。FIG. 4 is a control block diagram of the present invention. Step 61
The operating state of the vehicle is detected at step 62, and a target air-fuel ratio is set at step 62 based on this operating state. Step 63
Now, find the 02 sensor output corresponding to the target air-fuel ratio, and use this as the reference value.
ＲＯＭ ５０には対応する０２センチ出力がテーブルと
して記憶されており、目標空燃比に対応する０２センチ
出力はこのテーブルから直接、あるいは周知の補間法に
より求められる。前述の印加電圧切換装置１５はステッ
プ６２で設定された目標空燃比に関係して０２センサ１
への定電圧の印加を制御する。目標空燃比がほぼ理論空
燃比である場合には０２センサ１への定電圧の印加が中
止され、すなわち第１図において接点Ａ−Ｃ，Ｄ−Ｃ１
Ｆ−Ｈのような接続状態となり、０２センサ１は電圧出
力として作動する。また、目標空燃比が理論空燃比より
大きい空燃比、すなわち希薄側領域にある場合には０２
センサ１へ定電圧、例えＬ！ ０．７５ Ｖが印加され
、すなわち第１図において接点がＡ−Ｂ、 Ｄ−Ｅ、
Ｅ−Ｇのような接続状態となり、０２センサ１は電流出
力として作動する。The corresponding 02 cm output is stored in the ROM 50 as a table, and the 02 cm output corresponding to the target air-fuel ratio can be obtained directly from this table or by a well-known interpolation method. The above-mentioned applied voltage switching device 15 switches the 02 sensor 1 in relation to the target air-fuel ratio set in step 62.
Controls the application of constant voltage to. When the target air-fuel ratio is approximately the stoichiometric air-fuel ratio, the application of constant voltage to the 02 sensor 1 is stopped, that is, the contacts A-C and D-C1 in FIG.
A connection state such as F-H is established, and the 02 sensor 1 operates as a voltage output. Also, if the target air-fuel ratio is higher than the stoichiometric air-fuel ratio, that is, in the lean side region, 02
Constant voltage to sensor 1, for example L! 0.75 V is applied, i.e. in FIG. 1 the contacts are A-B, D-E,
A connection state such as E-G is established, and the 02 sensor 1 operates as a current output.
ステップ６４では、０２センサ１の出力と基準値とが比
較され、この比較に基づいてステップ６５で燃料供給量
を決定する。機料供給装置２４はステップ６５における
決定された燃料供給量に基づいて制御される。帰還空燃
比が目標空燃比ｌ二対して燃料希薄側へずれている場合
、燃料供給量は増大され、帰還空燃比が目標空燃比に対
して燃料過濃側へずれている場合、燃料供給量は減少さ
れる。In step 64, the output of the 02 sensor 1 is compared with a reference value, and based on this comparison, the fuel supply amount is determined in step 65. The fuel supply device 24 is controlled based on the fuel supply amount determined in step 65. If the return air-fuel ratio deviates toward the fuel-lean side with respect to the target air-fuel ratio l2, the fuel supply amount is increased, and if the return air-fuel ratio deviates toward the fuel-rich side with respect to the target air-fuel ratio, the fuel supply amount increases. is reduced.
なお吸気系への燃料供給量の代わりに吸気系への空気供
給量を制御する内燃機関では、例えば気化器において空
燃比の小さい、すなわち過濃の混合気を生成し、吸気管
への新気の供給量を制御して空燃比を制御する内燃機関
では、帰還空燃比が目標空燃比に対して希薄側へずれて
いる場合には吸気管への新気の供給量は減少され、帰還
空燃比が目標空燃比に対して過濃側へずれている場合に
は吸気管への新気の供給量は増大される。In an internal combustion engine that controls the amount of air supplied to the intake system instead of the amount of fuel supplied to the intake system, for example, the carburetor generates a mixture with a low air-fuel ratio, that is, a very rich mixture, and fresh air is sent to the intake pipe. In an internal combustion engine that controls the air-fuel ratio by controlling the supply amount of fresh air, if the return air-fuel ratio deviates to the lean side with respect to the target air-fuel ratio, the amount of fresh air supplied to the intake pipe is reduced, and the return air When the fuel ratio deviates to the rich side with respect to the target air-fuel ratio, the amount of fresh air supplied to the intake pipe is increased.
第５図は本発明を実施するプログラムのフローチャート
である。ステップ７０では車両の運転状態を検出する。FIG. 5 is a flowchart of a program implementing the present invention. In step 70, the driving state of the vehicle is detected.
ステップ７１では、車両の運転状態に応じて目標空燃比
を予め定めたテーブルから目標空燃比を設定する。ステ
ップ７２では目標空燃比が理論空燃比か香かを判別し、
判別結果が正であればステップ７３へ、否であればステ
ップ７５へ進む。ステップ７３では０２センサ１への定
電圧の印加を中止する。ステップ７４では比較電圧をｖ
ｒに設定する。ステップ７４における比較電圧ｖｒは、
混合気の空燃比が理論空燃比である場合の０２センサ１
の出力電圧とする。また、ステップ７５では０２センサ
１に定電圧、例えば０．５〜１、ＯＶの範囲内の所定電
圧、典型として０．７５Ｖを印加する。ステップ７６で
は目標空燃比（この目標空燃比は理論空燃比より大きい
。）と電圧との関係を定める表から目標空燃比に対応す
る電圧を比較電圧Ｖｉとして設定する。比較電圧ｖｉは
、空燃比がちょうど目標空燃比にある場合の０２センサ
１の出力電流を電圧へ変換した電圧値である。こうして
０２センサ１を電圧出力として作動させた場合には０２
センサ１の出力電圧と基準電圧ｖｒとを比較して吸気系
への燃料あるいは空気の供給量を増減し、０２センサ１
を電流出力として作動させている場合には０２センサ１
の出力電流を電圧へ変換した値と基準電圧Ｖｉとを比較
して吸気系への燃料あるいは空気の供給量を増減する。In step 71, a target air-fuel ratio is set from a table in which target air-fuel ratios are predetermined according to the driving state of the vehicle. In step 72, it is determined whether the target air-fuel ratio is the stoichiometric air-fuel ratio or the stoichiometric air-fuel ratio,
If the determination result is positive, the process proceeds to step 73; if not, the process proceeds to step 75. In step 73, application of the constant voltage to the 02 sensor 1 is stopped. In step 74, the comparison voltage is set to v
Set to r. The comparison voltage vr in step 74 is
02 sensor 1 when the air-fuel ratio of the mixture is the stoichiometric air-fuel ratio
The output voltage is Further, in step 75, a constant voltage, for example, a predetermined voltage within the range of 0.5 to 1 OV, typically 0.75V, is applied to the 02 sensor 1. In step 76, a voltage corresponding to the target air-fuel ratio is set as the comparison voltage Vi from a table that defines the relationship between the target air-fuel ratio (this target air-fuel ratio is greater than the stoichiometric air-fuel ratio) and voltage. The comparison voltage vi is a voltage value obtained by converting the output current of the 02 sensor 1 into a voltage when the air-fuel ratio is exactly at the target air-fuel ratio. In this way, when 02 sensor 1 is operated as a voltage output, 02
The output voltage of sensor 1 is compared with the reference voltage vr, and the amount of fuel or air supplied to the intake system is increased or decreased.
When operating as a current output, 02 sensor 1
A value obtained by converting the output current into a voltage is compared with a reference voltage Vi to increase or decrease the amount of fuel or air supplied to the intake system.
第６図は車両がアイドリンク状態から定常走行状態へ移
るまでの実際の空燃比等の変化を示している。加速期間
では、大きな機関出力を必要とするので、目標空燃比は
理論空燃比１４．６に設定される。したがって０２セン
サ１は電圧出力として作動される。定常走行期間では、
さほど大きな機関出力を必要としないので、目標空燃比
は比較的大きい値としての１９に設定され、すなわち０
２センサ１は電流出力として作動され、燃費の減少およ
び排気中の有害成分量の抑制が図られる。アイドリンク
期間は大きな機関出力は不必要であるが、少ない吸入空
気流量にもかかわらず安定な機関運転を確保する必要が
あるので、目標空燃比は中間の値１５ないし１６に設定
される。なお空燃比１５ないし１６は、窒素酸化物の発
生量が最大となる空燃比１７を外して設定されたもので
ある。FIG. 6 shows the actual changes in the air-fuel ratio, etc., as the vehicle moves from the idling state to the steady running state. During the acceleration period, a large engine output is required, so the target air-fuel ratio is set to the stoichiometric air-fuel ratio of 14.6. The 02 sensor 1 is therefore operated as a voltage output. During the steady running period,
Since a very large engine output is not required, the target air-fuel ratio is set to a relatively large value of 19, i.e., 0.
2 sensor 1 is operated as a current output, reducing fuel consumption and suppressing the amount of harmful components in exhaust gas. Although a large engine output is not required during the idle link period, it is necessary to ensure stable engine operation despite a small intake air flow rate, so the target air-fuel ratio is set to an intermediate value of 15 to 16. Note that the air-fuel ratios 15 and 16 are set apart from the air-fuel ratio 17, which produces the maximum amount of nitrogen oxides.
このように本発明によれば、車両の運転状態に関係して
目標空燃比を設定し、目標空燃比がほぼ理論空燃比であ
る場合（＝は酸素センサを電圧出力として作動させ、目
標空燃比が′理論空燃比より大きい場合には酸素センサ
を電流出力として作動させる。こうして空燃比が車両の
運転状態に適した値に制御され、機関の運転性能および
燃料消費効率を向上し、かつ排気ガス中の有害成分量を
減少させることができる。As described above, according to the present invention, the target air-fuel ratio is set in relation to the driving state of the vehicle, and when the target air-fuel ratio is approximately the stoichiometric air-fuel ratio (=, the oxygen sensor is operated as a voltage output, and the target air-fuel ratio is When is larger than the stoichiometric air-fuel ratio, the oxygen sensor is operated as a current output.In this way, the air-fuel ratio is controlled to a value suitable for the vehicle operating condition, improving engine operating performance and fuel consumption efficiency, and reducing exhaust gas. The amount of harmful ingredients inside can be reduced.
第１図は酸素センサおよび印加電圧の切換装置の構成お
よび接続を示す図、第２図（ａ）および（ｂ）は酸素セ
ンサをそれぞれ電流出力および電圧出力として作動させ
た場合の出力特性図、第３図は燃料噴射量を計算する電
子制御部のブロック図、第４図は本発明の制御ブロック
図、第５図は本発明を実施するプログラムのフローチャ
ート、第６図は車両がアイドリンク状態から定常走行状
態へ変化する場合における実際の空燃比等の変化を示す
図である。
１・・・０２センサ、１５・・・印加電圧切換装置、２
０・・・センサ群、２２・・・制御部、２４・・・燃料
供給装置。
特許出願人 トヨタ自動車工業株式会社第２図
（ａ’）
（ｂ＞
空燃比
第５図
時 間FIG. 1 is a diagram showing the configuration and connection of the oxygen sensor and the applied voltage switching device, and FIGS. 2 (a) and (b) are output characteristic diagrams when the oxygen sensor is operated as current output and voltage output, respectively. Fig. 3 is a block diagram of the electronic control unit that calculates the fuel injection amount, Fig. 4 is a control block diagram of the present invention, Fig. 5 is a flowchart of a program implementing the present invention, and Fig. 6 shows the vehicle in an idling state. FIG. 3 is a diagram showing actual changes in the air-fuel ratio, etc. when the vehicle changes from a state to a steady running state. 1...02 sensor, 15...applied voltage switching device, 2
0...Sensor group, 22...Control unit, 24...Fuel supply device. Patent applicant: Toyota Motor Corporation Figure 2 (a') (b> Air-fuel ratio Figure 5 Time
Claims (1)
排気系の酸素濃度に関係する出力電流を発生し、定電圧
の印加を中止されている場合にはほぼ理論空燃比を境に
して出力電圧レベルを反転し、このような酸素センサの
出力を帰還信号として用いる内燃機関の空燃比制御方法
において、車両の運転状態に関係して目標空燃比を設定
し、目標空燃比に関係して酸素センサへの定電圧の印加
を制御し、目標空燃比と酸素センサからの帰還空燃比を
比較して吸気系への燃料あるいは空気の供給量を増減す
ることを特徴とする、内燃機関の空燃比制御方法。 ２、 目標空燃比に対応する酸素センナ出力を求め、こ
の対応出力と酸素センナの出力とを比較して吸気系への
燃料あるいは空気供給量を増減することを特徴とする特
許請求の範囲第１項記載の内燃機関の空燃比制御方法。 ３、加速期間では酸素センサへの定電圧の印加を中止し
て酸素センナを電圧出力として作動させ、アイドリンク
期間および定常走行期間では酸素センサへ定電圧を印加
して酸素センサを電流出力として作動させることを特徴
とする特許請求の範囲第１項あるいは第２項記載の内燃
機関の空燃比制御方法。[Claims] 1. The oxygen sensor generates an output current related to the oxygen concentration in the exhaust system when a constant voltage is applied, and almost theoretically when the constant voltage is not applied. In an air-fuel ratio control method for an internal combustion engine in which the output voltage level is inverted based on the air-fuel ratio and the output of such an oxygen sensor is used as a feedback signal, a target air-fuel ratio is set in relation to the operating state of the vehicle. It is characterized by controlling the application of a constant voltage to the oxygen sensor in relation to the air-fuel ratio, and comparing the target air-fuel ratio and the feedback air-fuel ratio from the oxygen sensor to increase or decrease the amount of fuel or air supplied to the intake system. An air-fuel ratio control method for internal combustion engines. 2. The first aspect of the present invention is characterized in that the oxygen sensor output corresponding to the target air-fuel ratio is determined, and the corresponding output and the oxygen sensor output are compared to increase or decrease the amount of fuel or air supplied to the intake system. The air-fuel ratio control method for an internal combustion engine as described in . 3. During the acceleration period, the application of a constant voltage to the oxygen sensor is stopped and the oxygen sensor is operated as a voltage output, and during the idle link period and steady running period, a constant voltage is applied to the oxygen sensor and the oxygen sensor is operated as a current output. An air-fuel ratio control method for an internal combustion engine according to claim 1 or 2, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57024345A JPS58143108A (en) | 1982-02-19 | 1982-02-19 | Air-fuel ratio control method for internal-combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57024345A JPS58143108A (en) | 1982-02-19 | 1982-02-19 | Air-fuel ratio control method for internal-combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58143108A true JPS58143108A (en) | 1983-08-25 |
| JPH0529776B2 JPH0529776B2 (en) | 1993-05-06 |
Family
ID=12135595
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57024345A Granted JPS58143108A (en) | 1982-02-19 | 1982-02-19 | Air-fuel ratio control method for internal-combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58143108A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5983049A (en) * | 1982-11-04 | 1984-05-14 | Hitachi Ltd | Oxygen concentration controller |
| JPS60230537A (en) * | 1984-05-01 | 1985-11-16 | Nissan Motor Co Ltd | Air-fuel ratio controller |
| US4587938A (en) * | 1984-05-07 | 1986-05-13 | Toyota Jidosha Kabushiki Kaisha | Control device for controlling air-fuel ratio and spark timing of an integral combustion engine |
| US4592315A (en) * | 1984-05-07 | 1986-06-03 | Toyota Jidosha Kabushiki Kaisha | Control device of an internal combustion engine |
| US4598678A (en) * | 1984-05-07 | 1986-07-08 | Toyota Jidosha Kabushiki Kaisha | Intake system of an internal combustion engine |
| US4725955A (en) * | 1984-05-07 | 1988-02-16 | Toyota Jidosha Kabushiki Kaisha | Apparatus for controlling ignition timing in an internal combustion engine |
| DE3830574A1 (en) * | 1987-09-09 | 1989-03-23 | Hitachi Ltd | APPARATUS FOR CONTROLLING THE AIR / FUEL RATIO FOR A MULTI-CYLINDER ENGINE |
| US5443594A (en) * | 1992-05-27 | 1995-08-22 | Toyota Jidosha Kabushiki Kaisha | Air-fuel ratio control apparatus of vehicle equipped with automatic transmission |
| JP2008281584A (en) * | 2008-08-25 | 2008-11-20 | Denso Corp | Oxygen sensor element |
| JP2008286810A (en) * | 2008-08-25 | 2008-11-27 | Denso Corp | Oxygen sensor element |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53122013A (en) * | 1977-03-30 | 1978-10-25 | Toyota Motor Corp | Air fuel ratio controller for internal combustion engine |
| JPS54158992A (en) * | 1978-05-31 | 1979-12-15 | Westinghouse Electric Corp | Device for supervising oxygen and inflammable constituent |
| JPS562548A (en) * | 1979-06-22 | 1981-01-12 | Nissan Motor Co Ltd | Controller for air fuel ratio of internal combustion engine |
-
1982
- 1982-02-19 JP JP57024345A patent/JPS58143108A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53122013A (en) * | 1977-03-30 | 1978-10-25 | Toyota Motor Corp | Air fuel ratio controller for internal combustion engine |
| JPS54158992A (en) * | 1978-05-31 | 1979-12-15 | Westinghouse Electric Corp | Device for supervising oxygen and inflammable constituent |
| JPS562548A (en) * | 1979-06-22 | 1981-01-12 | Nissan Motor Co Ltd | Controller for air fuel ratio of internal combustion engine |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06100571B2 (en) * | 1982-11-04 | 1994-12-12 | 株式会社日立製作所 | Oxygen concentration controller |
| JPS5983049A (en) * | 1982-11-04 | 1984-05-14 | Hitachi Ltd | Oxygen concentration controller |
| JPH0428899B2 (en) * | 1984-05-01 | 1992-05-15 | Nissan Motor | |
| JPS60230537A (en) * | 1984-05-01 | 1985-11-16 | Nissan Motor Co Ltd | Air-fuel ratio controller |
| US4592315A (en) * | 1984-05-07 | 1986-06-03 | Toyota Jidosha Kabushiki Kaisha | Control device of an internal combustion engine |
| US4725955A (en) * | 1984-05-07 | 1988-02-16 | Toyota Jidosha Kabushiki Kaisha | Apparatus for controlling ignition timing in an internal combustion engine |
| US4598678A (en) * | 1984-05-07 | 1986-07-08 | Toyota Jidosha Kabushiki Kaisha | Intake system of an internal combustion engine |
| US4587938A (en) * | 1984-05-07 | 1986-05-13 | Toyota Jidosha Kabushiki Kaisha | Control device for controlling air-fuel ratio and spark timing of an integral combustion engine |
| DE3830574A1 (en) * | 1987-09-09 | 1989-03-23 | Hitachi Ltd | APPARATUS FOR CONTROLLING THE AIR / FUEL RATIO FOR A MULTI-CYLINDER ENGINE |
| US4909223A (en) * | 1987-09-09 | 1990-03-20 | Hitachi, Ltd. | Air-fuel ratio control apparatus for multicylinder engine |
| US5443594A (en) * | 1992-05-27 | 1995-08-22 | Toyota Jidosha Kabushiki Kaisha | Air-fuel ratio control apparatus of vehicle equipped with automatic transmission |
| JP2008281584A (en) * | 2008-08-25 | 2008-11-20 | Denso Corp | Oxygen sensor element |
| JP2008286810A (en) * | 2008-08-25 | 2008-11-27 | Denso Corp | Oxygen sensor element |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0529776B2 (en) | 1993-05-06 |
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