JPH0750070B2 - Oxygen concentration detector - Google Patents
Oxygen concentration detectorInfo
- Publication number
- JPH0750070B2 JPH0750070B2 JP61046966A JP4696686A JPH0750070B2 JP H0750070 B2 JPH0750070 B2 JP H0750070B2 JP 61046966 A JP61046966 A JP 61046966A JP 4696686 A JP4696686 A JP 4696686A JP H0750070 B2 JPH0750070 B2 JP H0750070B2
- Authority
- JP
- Japan
- Prior art keywords
- oxygen concentration
- oxygen
- gain
- air
- voltage
- 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
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- Measuring Oxygen Concentration In Cells (AREA)
Description
【発明の詳細な説明】 技術分野 本発明は、エンジン排気ガス等の気体中の酸素濃度を検
出する酸素濃度検出装置に関するものである。TECHNICAL FIELD The present invention relates to an oxygen concentration detection device for detecting oxygen concentration in gas such as engine exhaust gas.
背景技術 内燃エンジンの排気ガス浄化、燃費改善等を目的とし
て、排気ガス中の酸素濃度を検出し、この検出結果に応
じてエンジンへの供給混合気の空燃比を目標空燃比にフ
ィードバック制御する空燃比制御装置がある。BACKGROUND ART An air-fuel ratio that detects the oxygen concentration in the exhaust gas and purifies the air-fuel ratio of the air-fuel mixture supplied to the engine by feedback control to the target air-fuel ratio according to the detection results for the purpose of purifying exhaust gas from internal combustion engines and improving fuel efficiency. There is a fuel ratio control device.
このような空燃比制御装置に用いられる酸素濃度検出装
置として被測定気体中の酸素濃度に比例した出力を発生
するものがある。その一例として、例えば、平板状の酸
素イオン伝導性固体電解質部材の両主面に電極対を設け
て固体電解質部材の一方の電極面が気体滞留室の一部を
なしてその気体滞留室が被測定気体と導入孔を介して連
通するようにした限界電流方式の酸素濃度検出装置があ
る（特開昭52−72286号公報参照）。As an oxygen concentration detecting device used in such an air-fuel ratio control device, there is one which generates an output proportional to the oxygen concentration in the gas to be measured. As an example thereof, for example, an electrode pair is provided on both main surfaces of a flat plate-shaped oxygen ion conductive solid electrolyte member, and one electrode surface of the solid electrolyte member forms a part of the gas retention chamber and the gas retention chamber is covered. There is a limiting current type oxygen concentration detection device which communicates with a measurement gas through an introduction hole (see Japanese Patent Application Laid-Open No. 52-72286).
この酸素濃度検出装置においては、酸素イオン伝導性固
体電解質部材と電極対とが酸素ポンプ素子として作用し
て間隙室側電極が負極になるように電極間に電流を供給
すると、負極面側にて気体滞留室内気体中の酸素ガスが
イオン化して固体電解質部材内を正極面側に移動し正極
面から酸素ガスとして放出される。このときの電極間に
流れ得る限界電流値は印加電圧に拘らずほぼ一定となり
かつ被測定気体中の酸素濃度に比例するのでその限界電
流値を検出すれば被測定気体中の酸素濃度を測定するこ
とができる。In this oxygen concentration detection device, when the oxygen ion conductive solid electrolyte member and the electrode pair act as an oxygen pump element to supply a current between the electrodes so that the gap chamber side electrode becomes the negative electrode, the negative electrode surface side Oxygen gas in the gas in the gas retention chamber is ionized, moves inside the solid electrolyte member toward the positive electrode surface, and is released as oxygen gas from the positive electrode surface. The limiting current value that can flow between the electrodes at this time is almost constant regardless of the applied voltage and is proportional to the oxygen concentration in the gas to be measured. Therefore, if the limiting current value is detected, the oxygen concentration in the gas to be measured is measured. be able to.
しかしながら、かかる酸素濃度検出装置を用いて空燃比
を制御する場合に排気ガス中の酸素濃度からは混合気の
空燃比が理論空燃比よりリーンの範囲でしか酸素濃度に
比例した出力が得られないので目標空燃比をリッチ領域
に設定した空燃比制御は不可能であった。However, when controlling the air-fuel ratio using such an oxygen concentration detection device, an output proportional to the oxygen concentration can be obtained from the oxygen concentration in the exhaust gas only when the air-fuel ratio of the air-fuel mixture is leaner than the stoichiometric air-fuel ratio. Therefore, the air-fuel ratio control in which the target air-fuel ratio is set in the rich region was impossible.
また、空燃比がリーン及びリッチ領域にて排気ガス中の
酸素濃度に比例した出力が得られる酸素濃度検出装置と
して、２つの平板状の酸素イオン伝導性固体電解質部材
各々に電極対を設けて２つの固体電解質部材の一方の電
極面各々が気体滞留室の一部をなしてその気体滞留室が
被測定気体と導入孔を介して連通し一方の固体電解質部
材の他方の電極面が大気室に面するようにした装置があ
る（特開昭59−192955号公報参照）。Further, as an oxygen concentration detecting device that can obtain an output proportional to the oxygen concentration in the exhaust gas in the lean and rich regions of the air-fuel ratio, two flat plate-shaped oxygen ion conductive solid electrolyte members are provided with electrode pairs, respectively. One electrode surface of each of the two solid electrolyte members forms a part of the gas retention chamber, and the gas retention chamber communicates with the gas to be measured through the introduction hole. There is a device which is made to face (see Japanese Patent Application Laid-Open No. 59-192955).
この酸素濃度検出装置においては、一方の酸素イオン伝
導性固体電解質部材と電極対とが酸素濃度比検出電池素
子として作用し他方の酸素イオン伝導性固体電解質材と
電極対とが酸素ポンプ素子として作用するようになって
いる。酸素濃度比検出電池素子の電極間の発生電圧が基
準電圧以上のとき酸素ポンプ素子内を酸素イオンが気体
滞留室側電極に向って移動するように電流を供給し、酸
素濃度比検出電池素子の電極間の発生電圧が基準電圧以
下のとき酸素ポンプ素子内を酸素イオンが気体滞留室側
とは反対側の電極に向って移動するように電流を供給す
ることによりリーン及びリッチ領域の空燃比において電
流値は酸素濃度に比例するのである。In this oxygen concentration detector, one oxygen ion conductive solid electrolyte member and the electrode pair act as an oxygen concentration ratio detecting battery element, and the other oxygen ion conductive solid electrolyte material and the electrode pair act as an oxygen pump element. It is supposed to do. When the voltage generated between the electrodes of the oxygen concentration ratio detection battery element is equal to or higher than the reference voltage, a current is supplied so that oxygen ions move in the oxygen pump element toward the gas retention chamber side electrode, and the oxygen concentration ratio detection battery element When the generated voltage between the electrodes is less than the reference voltage, by supplying current so that oxygen ions move in the oxygen pump element toward the electrode on the side opposite to the gas retention chamber side, the air-fuel ratio in the lean and rich regions is increased. The current value is proportional to the oxygen concentration.
しかしながら、かかる酸素濃度検出装置においては、リ
ッチ側とリーン側とでは酸素濃度検出特性が異なるの
で、広領域において直線性の良好な酸素濃度検出出力が
得られないという問題点があった。However, in such an oxygen concentration detection device, since the oxygen concentration detection characteristics differ between the rich side and the lean side, there is a problem in that an oxygen concentration detection output having good linearity cannot be obtained in a wide region.
発明の概要 そこで、本発明は、空燃比のリーン及びリッチ領域に亘
って良好な直線性にて酸素濃度検出出力を得ることが可
能な酸素濃度検出装置を提供することを目的とする。SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an oxygen concentration detection device capable of obtaining an oxygen concentration detection output with excellent linearity over lean and rich regions of an air-fuel ratio.
本発明による酸素濃度検出装置は、酸素イオン伝導性固
体電解質壁部を有しかつ気体拡散制限手段を介して外部
に連通する気体滞留室を形成する基体及びこの基体内に
おいて気体滞留室の固体電解質壁部の内外壁面上にこれ
を挟んで対向するが如く設けられた２つの電極対を含む
センサ本体と、これら２つの電極対の一方の電極対間に
発生した電圧と所定基準電圧との差電圧に応じた値のポ
ンプ電流を他方の電極対間に供給する電流供給手段と、
ポンプ電流を増幅する可変利得増幅手段とを備え、ポン
プ電流の流れる方向を検出しその方向に応じて増幅手段
の利得を変化せしめるようになされたことを特徴として
いる。The oxygen concentration detecting device according to the present invention is a substrate having an oxygen ion conductive solid electrolyte wall portion and forming a gas retention chamber communicating with the outside through a gas diffusion limiting means, and a solid electrolyte of the gas retention chamber in the substrate. A sensor main body including two electrode pairs provided so as to face each other on both inner and outer wall surfaces of the wall portion, and a difference between a voltage generated between one of the two electrode pairs and a predetermined reference voltage. A current supply means for supplying a pump current having a value corresponding to the voltage between the other electrode pair,
A variable gain amplifying means for amplifying the pump current is provided, and the direction of the pump current is detected and the gain of the amplifying means is changed according to the direction.
実施例 以下、本発明の実施例を図面を参照しつつ説明する。Embodiments Embodiments of the present invention will be described below with reference to the drawings.
第１図において、酸素濃度センサ本体10は、ほぼ立方体
状の酸素イオン伝導性固体電解質部材１を有しており、
この酸素イオン伝導性固体電解質部材１内には気体滞留
室２が形成されている。気体滞留室２は被測定気体であ
る排気ガスを導入する導入孔４を介して外部に連通し、
導入孔４は内燃エンジンの排気管（図示せず）内におい
て排気ガスが気体滞留室２内に流入し易いように位置さ
れる。また酸素イオン伝導性固体電解質部材１には大気
を導入する大気基準室５が気体滞留室２と壁を隔てるよ
うに形成されている。気体滞留室２と大気基準室５との
間の壁部及び大気基準室５とは反対側の壁部には電極対
7a,7b,6a,6bが各々設けられている。そして、固体電解
質部材１及び電極対6a,6bが酸素ポンプ素子８として作
用し、固体電解質部材１及び電極対7a,7bが電池素子９
として作用する。In FIG. 1, an oxygen concentration sensor main body 10 has a substantially cubic oxygen ion conductive solid electrolyte member 1,
A gas retention chamber 2 is formed in the oxygen ion conductive solid electrolyte member 1. The gas retention chamber 2 communicates with the outside through an introduction hole 4 for introducing the exhaust gas, which is the gas to be measured,
The introduction hole 4 is located in an exhaust pipe (not shown) of the internal combustion engine so that the exhaust gas can easily flow into the gas retention chamber 2. Further, the oxygen ion conductive solid electrolyte member 1 is formed with an atmosphere reference chamber 5 for introducing the atmosphere so as to separate the wall from the gas retention chamber 2. An electrode pair is provided on the wall between the gas retention chamber 2 and the atmospheric reference chamber 5 and on the wall opposite to the atmospheric reference chamber 5.
7a, 7b, 6a, 6b are provided respectively. Then, the solid electrolyte member 1 and the electrode pairs 6a, 6b act as the oxygen pump element 8, and the solid electrolyte member 1 and the electrode pairs 7a, 7b act as the battery element 9.
Acts as.
酸素イオン伝導性固体電解質部材１としては、ZrO2（二
酸化ジルコニウム）が用いられ、電極6a,6b,7a,7bとし
てはPt（白金）が用いられる。ZrO 2 (zirconium dioxide) is used as the oxygen ion conductive solid electrolyte member 1, and Pt (platinum) is used as the electrodes 6a, 6b, 7a, 7b.
酸素ポンプ素子８の電極6b及び電池素子９の電極7bはア
ースされている。電池素子９の電極7aには誤差増幅器11
の反転入力端が接続されており、この誤差増幅器11は電
池素子９の電極7a,7b間の発生電圧と基準電圧源12から
非反転入力端に印加される基準電圧Vrとの差電圧に応じ
た電圧を出力する。基準電圧源12によって与えられる基
準電圧Vrは理論空燃比に相当する電圧（例えば、0.4V）
に設定される。誤差増幅器11の出力端は電流検出用抵抗
13を介して酸素ポンプ素子８の電極6aに接続されてい
る。電流検出用抵抗13の両端電圧は酸素濃度検出値とし
て差動増幅器14に供給されると共に、極性判定回路15に
も供給される。極性判定回路15は電流検出用抵抗13の両
端電圧の極性を判定することによって電流検出用抵抗13
を流れる電流の方向を検出するものであり、当該回路15
としては例えばコンパレータ等からなる周知の回路構成
のものを用い得る。The electrode 6b of the oxygen pump element 8 and the electrode 7b of the battery element 9 are grounded. An error amplifier 11 is provided on the electrode 7a of the battery element 9.
The error amplifier 11 is connected to the inverting input terminal of the battery element 9 according to the difference voltage between the voltage generated between the electrodes 7a and 7b of the battery element 9 and the reference voltage Vr applied from the reference voltage source 12 to the non-inverting input terminal. Output voltage. The reference voltage Vr provided by the reference voltage source 12 is a voltage corresponding to the stoichiometric air-fuel ratio (for example, 0.4V)
Is set to. The output terminal of the error amplifier 11 is a current detection resistor.
It is connected via 13 to the electrode 6 a of the oxygen pump element 8. The voltage across the current detection resistor 13 is supplied to the differential amplifier 14 as an oxygen concentration detection value and also to the polarity determination circuit 15. The polarity determination circuit 15 determines the polarity of the voltage across the current detection resistor 13 to determine the polarity of the current detection resistor 13
The circuit 15 detects the direction of the current flowing through
For example, a well-known circuit having a comparator or the like can be used.
差動増幅器14は電流検出用抵抗13の両端電圧をシングル
エンド電圧出力として導出し、増幅回路16を構成する演
算増幅器17の非反転入力端に供給する。増幅回路16にお
いては、演算増幅器17の反転入力端と出力端との間に抵
抗18が、反転入力端とアースとの間に抵抗19が各々接続
され、更に抵抗19には抵抗20及びスイッチ21の直列回路
が並列に接続されており、スイッチ21のオン・オフによ
って利得が２段階に可変な可変利得増幅回路構成となっ
ている。すなわち、抵抗18,19,20の各抵抗値をRf,Rsa,R
sbとすると、スイッチ21のオフ時の利得Ga及びオン時の
利得Gbは、 で表わされ、スイッチ21のオフ時の利得がオン時よりも
小さく設定されることになる。スイッチ21のオン・オフ
駆動は判定回路15の判定出力によって行なわれる。The differential amplifier 14 derives the voltage across the current detection resistor 13 as a single-ended voltage output, and supplies it to the non-inverting input terminal of the operational amplifier 17 that constitutes the amplifier circuit 16. In the amplifier circuit 16, a resistor 18 is connected between the inverting input terminal and the output terminal of the operational amplifier 17, and a resistor 19 is connected between the inverting input terminal and the ground. Further, the resistor 19 has a resistor 20 and a switch 21. Is connected in parallel, and has a variable gain amplification circuit configuration in which the gain is variable in two stages by turning on / off the switch 21. That is, the resistance values of the resistors 18, 19, and 20 are changed to Rf, Rsa, and R
Assuming sb, the gain Ga when the switch 21 is off and the gain Gb when it is on are The gain when the switch 21 is off is set smaller than that when it is on. The on / off drive of the switch 21 is performed by the determination output of the determination circuit 15.
次に、かかる構成の回路動作について説明する。Next, the circuit operation of such a configuration will be described.
先ず、エンジン供給混合気の空燃比がリーン領域のとき
には、電池素子９の電極7a,7b間に発生する電圧が基準
電圧源12の基準電圧よりも低くなるので、誤差増幅器11
の出力レベルが正レベルになり、この正レベルの電圧が
抵抗13を介して酸素ポンプ素子８の電極6aに印加され
る。これにより、酸素ポンプ素子８には電極6aから電極
6bに向ってポンプ電流が流れるので、気体滞留室２内の
酸素が電極6bにてイオン化し酸素ポンプ素子８内を移動
して電極6aから酸素ガスとして放出され、よって気体滞
留室２内の酸素が汲み出されることになる。First, when the air-fuel ratio of the engine-supplied air-fuel mixture is in the lean region, the voltage generated between the electrodes 7a and 7b of the battery element 9 becomes lower than the reference voltage of the reference voltage source 12, so the error amplifier 11
Becomes a positive level, and this positive level voltage is applied to the electrode 6a of the oxygen pump element 8 via the resistor 13. As a result, the oxygen pump element 8 is connected to the electrode 6a through the electrode 6a.
Since the pump current flows toward 6b, oxygen in the gas retention chamber 2 is ionized at the electrode 6b, moves in the oxygen pump element 8 and is released as oxygen gas from the electrode 6a, so that oxygen in the gas retention chamber 2 is discharged. Will be pumped out.
気体滞留室２内の酸素の汲み出しにより気体滞留室２内
の排気ガスと大気基準室５内の大気との間に酸素濃度差
が生ずる。この酸素濃度差に応じた電圧Vsが電池素子９
の電極7a,7b間に発生し、この電圧Vsは誤差増幅器11の
反転入力端に供給される。誤差増幅器11の出力電圧は電
圧Vsと基準電圧Vrとの差電圧に比例した値となるので、
ポンプ電流値は排気ガス中の酸素濃度に比例し、ポンプ
電流値は抵抗13の両端電圧として出力される。By pumping out oxygen in the gas retention chamber 2, an oxygen concentration difference is generated between the exhaust gas in the gas retention chamber 2 and the atmosphere in the atmosphere reference chamber 5. The voltage Vs corresponding to the oxygen concentration difference is the battery element 9
This voltage Vs, which is generated between the electrodes 7a and 7b, is supplied to the inverting input terminal of the error amplifier 11. Since the output voltage of the error amplifier 11 has a value proportional to the difference voltage between the voltage Vs and the reference voltage Vr,
The pump current value is proportional to the oxygen concentration in the exhaust gas, and the pump current value is output as the voltage across the resistor 13.
一方、リッチ領域の空燃比のときには、電圧Vsが基準電
圧Vrを越えるので、誤差増幅器11の出力レベルが正レベ
ルから負レベルに遷移する。この負レベルにより酸素ポ
ンプ素子８の電極6a,6b間に流れるポンプ電流の方向が
反転する。すなわち、ポンプ電流は電極6bから電極6aの
方向に流れるので、外部の酸素が電極6aにてイオン化し
酸素ポンプ素子８内を移動して電極6bから酸素ガスとし
て気体滞留室２内に放出され、酸素が気体滞留室２内に
汲み込まれる。従って、気体滞留室２内の酸素濃度が常
に一定になるようにポンプ電流を供給することにより、
酸素を汲み込んだり、汲み出したりするので、ポンプ電
流値IP及び誤差増幅器11の出力電圧はリーン及びリッチ
領域にて排気ガス中の酸素濃度に各々比例するのであ
る。第２図の実線は空燃比とポンプ電流値IPの関係で表
わされる酸素濃度検出出力特性を示している。On the other hand, when the air-fuel ratio is in the rich region, the voltage Vs exceeds the reference voltage Vr, so that the output level of the error amplifier 11 transits from the positive level to the negative level. Due to this negative level, the direction of the pump current flowing between the electrodes 6a and 6b of the oxygen pump element 8 is reversed. That is, since the pump current flows in the direction from the electrode 6b to the electrode 6a, external oxygen is ionized at the electrode 6a and moves inside the oxygen pump element 8 to be released from the electrode 6b as oxygen gas into the gas retention chamber 2, Oxygen is pumped into the gas retention chamber 2. Therefore, by supplying the pump current so that the oxygen concentration in the gas retention chamber 2 is always constant,
Since oxygen is pumped in or pumped out, the pump current value I P and the output voltage of the error amplifier 11 are proportional to the oxygen concentration in the exhaust gas in the lean and rich regions, respectively. The solid line in FIG. 2 shows the oxygen concentration detection output characteristic represented by the relationship between the air-fuel ratio and the pump current value I P.
この酸素濃度検出出力特性は、第２図の実線ａから明ら
かなように、リッチ領域とリーン領域とで異なり、両領
域に亘って直線的な特性となってはいない。そこで、本
発明においては、増幅回路16の利得をリッチ領域とリー
ン領域とで切り替えることにより、第２図に破線ｂで示
す如くリッチ領域の出力特性がリーン領域の出力特性に
IP＝０にて直線的に連続する特性を得ている。As is clear from the solid line a in FIG. 2, the oxygen concentration detection output characteristic differs between the rich region and the lean region and is not a linear characteristic across both regions. Therefore, in the present invention, by switching the gain of the amplifier circuit 16 between the rich region and the lean region, the output characteristic in the rich region becomes the output characteristic in the lean region as shown by the broken line b in FIG.
A linearly continuous characteristic is obtained at I P = 0.
すなわち、空燃比がリーン領域のときには、ポンプ電流
IPが抵抗13を誤差増幅器11の出力端から酸素ポンプ素子
８の電極6aに向って流れており、極性判定回路15は抵抗
13の両端電圧の極性を判定し、ポンプ電流IPの流れる方
向を検出することによって空燃比がリーン領域にあるこ
とを検出し、スイッチ21をオンせしめる。これにより、
増幅回路16の利得は前記式（２）で与えられる利得Gbと
なり、この利得Gbで差動増幅器14の出力電圧を増幅す
る。That is, when the air-fuel ratio is in the lean range, the pump current
I P is flowing through the resistor 13 from the output end of the error amplifier 11 toward the electrode 6a of the oxygen pump element 8, and the polarity determination circuit 15 is
The polarity of the voltage across 13 is determined and the direction in which the pump current I P flows is detected to detect that the air-fuel ratio is in the lean region, and the switch 21 is turned on. This allows
The gain of the amplifier circuit 16 becomes the gain Gb given by the above equation (2), and the output voltage of the differential amplifier 14 is amplified by this gain Gb.
一方、空燃比がリッチ領域にあるときには、ポンプ電流
IPが抵抗13を酸素ポンプ素子８の電極6aから誤差増幅器
11の出力端に向って流れることになるので、極性判定回
路15は抵抗13の両端電圧の極性の反転を検出することに
よって空燃比がリッチ領域にあることを検出し、スイッ
チ21をオフせしめる。これにより、増幅回路16の利得は
前記式（１）で与えられる利得Gaとなり、この利得Gaで
差動増幅器14の出力電圧を増幅する。利得Gaは利得Gbよ
りも小さく設定されており、これらの値を抵抗18〜20の
抵抗値の選定により適当に設定することによって、増幅
回路16の出力としてはリッチ及びリーンの両領域に亘る
広い領域において良好な直線性の酸素濃度検出出力特性
が得られるのである。On the other hand, when the air-fuel ratio is in the rich region, the pump current
I P transfers the resistor 13 from the electrode 6a of the oxygen pump element 8 to the error amplifier
Since it flows toward the output terminal of 11, the polarity determination circuit 15 detects that the air-fuel ratio is in the rich region by detecting the inversion of the polarity of the voltage across the resistor 13, and turns off the switch 21. As a result, the gain of the amplifier circuit 16 becomes the gain Ga given by the equation (1), and the output voltage of the differential amplifier 14 is amplified by this gain Ga. The gain Ga is set to be smaller than the gain Gb, and by appropriately setting these values by selecting the resistance values of the resistors 18 to 20, the output of the amplifier circuit 16 is wide in both the rich and lean regions. A good linear oxygen concentration detection output characteristic can be obtained in the region.
発明の効果 以上説明したように、本発明による酸素濃度検出装置に
おいては、ポンプ電流を増幅する増幅回路の利得を可変
とし、この利得をポンプ電流の流れる方向に応じて切り
替えるように構成されているので、リーン及びリッチの
広い領域において被測定気体中の酸素濃度に比例したリ
ニアリティの良好な酸素濃度検出出力特性を得ることが
できる。よって、空燃比制御装置側で酸素濃度検出出力
を補正する必要がなく空燃比制御が容易となり、空燃比
制御精度の向上が図れるのである。EFFECTS OF THE INVENTION As described above, in the oxygen concentration detection device according to the present invention, the gain of the amplification circuit for amplifying the pump current is made variable, and this gain is switched according to the direction in which the pump current flows. Therefore, it is possible to obtain an oxygen concentration detection output characteristic with a good linearity proportional to the oxygen concentration in the gas to be measured in a wide lean and rich region. Therefore, it is not necessary to correct the oxygen concentration detection output on the air-fuel ratio control device side, the air-fuel ratio control becomes easy, and the air-fuel ratio control accuracy can be improved.
第１図は本発明の一実施例を示す回路図、第２図は第１
図の装置による補正前（ａ）及び補正後（ｂ）の酸素濃
度検出出力特性を示す図である。 主要部分の符号の説明 １……酸素イオン伝導性固体電解質部材 ２……気体滞留室、４……導入孔 ５……大気基準室、８……酸素ポンプ素子 ９……電池素子、11……誤差増幅器 15……極性判定回路 16……可変利得増幅回路FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG.
It is a figure which shows the oxygen concentration detection output characteristic before (a) and after correction (b) by the apparatus of the figure. Explanation of symbols of main parts 1 …… Oxygen ion conductive solid electrolyte member 2 …… Gas retention chamber, 4 …… Introduction hole 5 …… Atmosphere reference chamber, 8 …… Oxygen pump element 9 …… Battery element, 11 …… Error amplifier 15 …… Polarity judgment circuit 16 …… Variable gain amplification circuit
Claims (2)
つ気体拡散制限手段を介して外部に連通する気体滞留室
を形成する基体及びこの基体内において前記気体滞留室
の固体電解室壁部の内外壁面上にこれを挟んで対向する
が如く設けられた２つの電極対を含むセンサ本体と、前
記２つの電極対の一方の電極対間に発生した電圧と所定
基準電圧との差電圧に応じた値のポンプ電流を他方の電
極対間に供給する電流供給手段と、前記ポンプ電流を増
幅する可変利得増幅手段と、前記ポンプ電流の流れる方
向を検出しその方向に応じて前記増幅手段の利得を変化
せしめる手段とを備え、前記増幅手段の出力信号に基づ
いて酸素濃度を検出するようになされたことを特徴とす
る酸素濃度検出装置。1. A substrate having an oxygen ion conductive solid electrolyte wall portion and forming a gas retention chamber communicating with the outside through a gas diffusion limiting means, and a solid electrolytic chamber wall portion of the gas retention chamber in the substrate. A sensor main body including two electrode pairs provided so as to face each other on both inner and outer wall surfaces of the sensor, and a difference voltage between a voltage generated between one electrode pair of the two electrode pairs and a predetermined reference voltage. A current supply means for supplying a pump current of a corresponding value between the other electrode pair, a variable gain amplification means for amplifying the pump current, a direction in which the pump current flows, and the amplification means of the amplification means depending on the direction. An oxygen concentration detecting apparatus comprising: a means for changing a gain; and detecting the oxygen concentration based on an output signal of the amplifying means.
る混合気の空燃比がリッチ領域にあるときの利得がリー
ン領域にあるときの利得よりも小さく設定されることを
特徴とする特許請求の範囲第１項記載の酸素濃度検出装
置。2. The amplifying means is set so that the gain when the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine is in the rich region is set to be smaller than the gain when the air-fuel ratio is in the lean region. 2. An oxygen concentration detector according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61046966A JPH0750070B2 (en) | 1986-03-03 | 1986-03-03 | Oxygen concentration detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61046966A JPH0750070B2 (en) | 1986-03-03 | 1986-03-03 | Oxygen concentration detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62203056A JPS62203056A (en) | 1987-09-07 |
| JPH0750070B2 true JPH0750070B2 (en) | 1995-05-31 |
Family
ID=12762006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61046966A Expired - Fee Related JPH0750070B2 (en) | 1986-03-03 | 1986-03-03 | Oxygen concentration detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0750070B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102019201234A1 (en) * | 2019-01-31 | 2020-08-06 | Robert Bosch Gmbh | Method and device for operating a broadband lambda probe |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004205488A (en) * | 2002-11-08 | 2004-07-22 | Denso Corp | Device for detecting concentration of gas |
| JP4697052B2 (en) * | 2006-05-26 | 2011-06-08 | 株式会社デンソー | Gas concentration detector |
| US7802463B2 (en) | 2007-10-11 | 2010-09-28 | Ngk Spark Plug Co., Ltd. | Sensor control device and air fuel ratio detecting apparatus |
-
1986
- 1986-03-03 JP JP61046966A patent/JPH0750070B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102019201234A1 (en) * | 2019-01-31 | 2020-08-06 | Robert Bosch Gmbh | Method and device for operating a broadband lambda probe |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62203056A (en) | 1987-09-07 |
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