JP2557477B2 - Catalyst deterioration detector - Google Patents
Catalyst deterioration detectorInfo
- Publication number
- JP2557477B2 JP2557477B2 JP63175462A JP17546288A JP2557477B2 JP 2557477 B2 JP2557477 B2 JP 2557477B2 JP 63175462 A JP63175462 A JP 63175462A JP 17546288 A JP17546288 A JP 17546288A JP 2557477 B2 JP2557477 B2 JP 2557477B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- deterioration
- temperature
- operating state
- detecting
- 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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N9/00—Electrical control of exhaust gas treating apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
- F01N11/002—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
- F01N2550/02—Catalytic activity of catalytic converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Exhaust Gas After Treatment (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、触媒の劣化検知装置に係り、詳しくは、内
燃機関の排出ガス浄化装置に適用することができ、特
に、触媒により浄化を行う触媒コンバータの触媒の劣化
を検知する装置に関する。Description: TECHNICAL FIELD The present invention relates to a catalyst deterioration detection device, and more particularly, it can be applied to an exhaust gas purification device of an internal combustion engine, and in particular, purification is performed by a catalyst. The present invention relates to a device for detecting deterioration of a catalyst of a catalytic converter.
（従来の技術） 近年、公害規制の見地から内燃機関に対する有害な排
出ガスの低減への要求も高レベルになっている、触媒コ
ンバータにおいても触媒の劣化による浄化機能の低下を
検知する技術の向上が望まれる。(Prior art) In recent years, from the viewpoint of pollution control, there is a high level of demand for reducing harmful exhaust gas to internal combustion engines. Improvement of technology to detect deterioration of purification function due to catalyst deterioration in catalytic converters as well. Is desired.
従来のこの種の排出ガスの温度検出装置としては、例
えば特開昭56−88919号公報に記載のものがあり、図６
のように示される。この装置では、三元触媒を有する触
媒コンバータ１内に温度センサー２を設け、矢印で示す
ように排気管３を通して流れる排出ガスの温度が所定温
度以上になると、スイッチングモジュール４により警報
信号を発生して排気温度警告灯５を点灯させ、運転者に
知らせている。なお６はマフラーである。これにより、
運転者は触媒温度の異常を知ることができ、その後、異
常に対する処理を採ることになる。A conventional exhaust gas temperature detecting device of this type is disclosed in, for example, JP-A-56-88919.
As shown. In this device, a temperature sensor 2 is provided in a catalytic converter 1 having a three-way catalyst, and when a temperature of exhaust gas flowing through an exhaust pipe 3 reaches a predetermined temperature or more as shown by an arrow, a switching module 4 generates an alarm signal. The exhaust temperature warning light 5 is turned on to inform the driver. In addition, 6 is a muffler. This allows
The driver can know the abnormality in the catalyst temperature, and then take action for the abnormality.
（発明が解決しようとする課題） しかしながら、このような従来の排出ガスの温度検出
装置にあっては、単に触媒近傍の排気温度を検出し、こ
れが所定の温度以上のとき触媒が異常な温度であるとい
う警報を出力するに過ぎない構成となっていたため、こ
の異常な温度が直ちに触媒の劣化に結びつくのかあるい
は単なる一時的な温度上昇であるのかは区別ができず、
触媒の劣化を直接的に検知するには至っていない。した
がって、この点で触媒の劣化を直接的に検出する装置の
開発が望まれる。(Problems to be Solved by the Invention) However, in such a conventional exhaust gas temperature detection device, the exhaust gas temperature in the vicinity of the catalyst is simply detected, and when the temperature is equal to or higher than a predetermined temperature, the temperature of the catalyst is abnormal. Since it was configured to only output an alarm that there is, it is not possible to distinguish whether this abnormal temperature immediately leads to deterioration of the catalyst or is just a temporary temperature rise.
It has not been possible to directly detect the deterioration of the catalyst. Therefore, in this respect, it is desired to develop a device that directly detects the deterioration of the catalyst.
（発明の目的） そこで、本発明は、劣化した触媒は、その温度が低く
なるという事実に着目し、劣化の判定をする判定値を定
め、実際の触媒の温度をこの判定値と比較することによ
り、触媒の劣化を直接的に検知できる触媒の劣化検知装
置を提供する事を目的としている。(Object of the Invention) Therefore, the present invention focuses on the fact that the temperature of a deteriorated catalyst becomes low, determines a judgment value for judging deterioration, and compares the actual catalyst temperature with this judgment value. Therefore, it is an object of the present invention to provide a catalyst deterioration detecting device capable of directly detecting the deterioration of the catalyst.
（課題を解決するための手段） 本発明による触媒の劣化検知装置は上記目的達成のた
め、その基本概念図を第１図に示すように、触媒コンバ
ータ内の上流側および下流側に位置する複数箇所の触媒
の温度をそれぞれ検出する触媒温度検出手段ａと、エン
ジンの運転状態を検出する運転状態検出手段ｂと、運転
状態検出手段の出力に基づいて触媒の劣化判定値を設定
する判定値設定手段ｃと、触媒温度検出手段から出力さ
れる前記複数箇所の検出温度の差および判定値設定手段
の出力に基づいて触媒の劣化を判別する劣化判別手段ｄ
と、を備えている。(Means for Solving the Problems) In order to achieve the above object, a catalyst deterioration detecting device according to the present invention has a plurality of plural catalysts located upstream and downstream in a catalytic converter as shown in a basic conceptual diagram thereof. Catalyst temperature detecting means a for detecting the temperature of the catalyst at each location, operating state detecting means b for detecting the operating state of the engine, and determination value setting for setting the catalyst deterioration determination value based on the output of the operating state detecting means. Deterioration determination means d for determining the deterioration of the catalyst based on the difference between the detected temperatures at the plurality of locations output from the means c, the catalyst temperature detection means, and the output from the determination value setting means.
And
（作用） 本発明では、触媒温度検出手段により触媒の温度が検
出され、一方劣化した触媒の温度は低いという事実から
劣化判定値が運転状態に基づいて設定され、この判定値
と前記複数箇所で検出された触媒温度の差とが比較され
て、触媒の劣化が判別される。(Operation) In the present invention, the catalyst temperature detection means detects the temperature of the catalyst, and on the other hand, the deterioration determination value is set based on the operating state due to the fact that the temperature of the deteriorated catalyst is low. The detected catalyst temperature difference is compared to determine the catalyst deterioration.
したがって、直接的に触媒の劣化を検知することが可
能になる。Therefore, it becomes possible to directly detect the deterioration of the catalyst.
（実施例） 以下、本発明を図面に基づいて説明する。(Example) Hereinafter, the present invention will be described with reference to the drawings.
第２〜５図は本発明に係る触媒の劣化検知装置の一実
施例を示す図である。2 to 5 are views showing an embodiment of the catalyst deterioration detecting device according to the present invention.
まず、構成を説明する。第２図において、11は触媒コ
ンバータであり、触媒コンバータ11は排気管12の途中に
設置され、内部に三元触媒13と、２個（複数）の温度セ
ンサー（触媒温度検出手段）21、22とを収納している。
なお、排出ガスは図中矢印の方向に流れる。三元触媒13
としては、モノリス触媒が用いられており、モノリス触
媒にはハニカム形とステンレスウール形があるが本実施
例では、例えばアルミナのハニカム形が採用されてい
る。三元触媒13の周囲にはインシュレータ15が装着さ
れ、三元触媒13を保護している。First, the configuration will be described. In FIG. 2, reference numeral 11 denotes a catalytic converter, which is installed in the middle of an exhaust pipe 12 and has a three-way catalyst 13 inside and two (a plurality of) temperature sensors (catalyst temperature detecting means) 21, 22. And are stored.
The exhaust gas flows in the direction of the arrow in the figure. Three-way catalyst 13
For this, a monolith catalyst is used. The monolith catalyst has a honeycomb type and a stainless wool type, but in the present embodiment, for example, an alumina honeycomb type is used. An insulator 15 is attached around the three-way catalyst 13 to protect the three-way catalyst 13.
温度センサー21、22は、例えばクロメル・アルメル熱
電対から成り、一方の温度センサー21はそのセンサーの
先端が三元触媒13の上流部中心になるように、他方の温
度センサー22はそのセンサーの先端が三元触媒13の下流
部中心付近になるよう触媒コンバータ11の外筒11aに固
定されている。温度センサー21、22は三元触媒13の温度
を検出し、検出信号を増幅器23、24を通して判別回路17
に出力する。判別回路17にはさらに運転状態を検出して
いる運転状態検出手段18からの信号が入力されており、
運転状態検出手段18は運転状態として吸入空気量（エン
ジンの負荷に対応）、エンジン回転数、冷却水温、空燃
比等を検出し、検出信号を判別回路17に出力する。判別
回路17は判定値設定手段および劣化判別手段としての機
能を有し、例えばマイクロコンピュータにより構成され
る。判別回路17は内部メモリに格納されているプログラ
ムに従って、触媒の劣化判別に必要な処理値を演算し三
元触媒13が劣化していると判別したとき、警報信号を警
報灯19に出力する。警報灯19は警報信号が入力される
と、点灯して運転者に三元触媒13の劣化を直接的に警告
する。The temperature sensors 21 and 22 are, for example, chromel-alumel thermocouples, one temperature sensor 21 has its tip at the upstream center of the three-way catalyst 13, and the other temperature sensor 22 has its tip. Is fixed to the outer cylinder 11a of the catalytic converter 11 so that it is near the center of the downstream portion of the three-way catalyst 13. The temperature sensors 21 and 22 detect the temperature of the three-way catalyst 13, and the detection signal is passed through amplifiers 23 and 24 to a determination circuit 17
Output to. The discrimination circuit 17 further receives a signal from the driving state detecting means 18 for detecting the driving state,
The operating state detecting means 18 detects the intake air amount (corresponding to the load of the engine), the engine speed, the cooling water temperature, the air-fuel ratio, etc. as the operating state, and outputs a detection signal to the discrimination circuit 17. The determination circuit 17 has a function as a determination value setting unit and a deterioration determination unit, and is configured by, for example, a microcomputer. The determination circuit 17 outputs a warning signal to the warning light 19 when it determines that the three-way catalyst 13 is deteriorated by calculating a processing value necessary for determining deterioration of the catalyst according to a program stored in the internal memory. When an alarm signal is input, the alarm light 19 is turned on to directly warn the driver of the deterioration of the three-way catalyst 13.
次に、作用を説明する。 Next, the operation will be described.
排出ガスは排気管12を通して触媒コンバータ11に供給
され、三元触媒13による酸化、還元反応により有害ガス
が低減された後排気管12を通して排出される。反応にと
もなう熱量は触媒の温度として温度センサー21、22によ
って触媒コンバータ11の上流側および下流側の２点（複
数箇所）で検出され、温度センサ21、22の出力信号と運
転状態検出手段18の出力信号は判別回路17に入力され触
媒の劣化判定値が設定されて、触媒の劣化が判別される
が、これは第３図に示すプログラムにより実行される。The exhaust gas is supplied to the catalytic converter 11 through the exhaust pipe 12, and after the harmful gas is reduced by the oxidation and reduction reaction by the three-way catalyst 13, the exhaust gas is exhausted through the exhaust pipe 12. The amount of heat associated with the reaction is detected as the temperature of the catalyst by the temperature sensors 21 and 22 at two points (plural points) on the upstream side and the downstream side of the catalytic converter 11, and the output signals of the temperature sensors 21 and 22 and the operating state detection means 18 are detected. The output signal is input to the determination circuit 17 to set the catalyst deterioration determination value and the catalyst deterioration is determined, which is executed by the program shown in FIG.
第３図は三元触媒13の劣化判別を行うプログラムのフ
ローチャートであり、本プログラムは所定時間毎に一度
実行される。FIG. 3 is a flow chart of a program for determining deterioration of the three-way catalyst 13, and this program is executed once every predetermined time.
まず、P1からP6までのステップでエンジンの運転状態
を判別し、劣化判別に適切な状態であるか否かを判別す
る。すなわち、P1でエンジンの始動後所定時間以上が経
過したか否かを判別する。この判別は、例えばエンジン
のイグニションキースイッチONとなってからの時間を判
別回路17におけるマイクロコンピュータの有するカウン
ターで計測することにより行う。始動後所定時間以上が
経過しているときはP2に進み、経過していないときは今
回のルーチンを終了する。P2では冷却水の温度Twが所定
の温度範囲内にあるか否かを判別する。この温度範囲
は、例えば80℃＜Tw＜100℃であり、冷却水の温度がこ
の温度範囲内であればエンジンは冷却時でなく、かつオ
ーバーヒート状態でもないことになる。冷却水の温度Tw
が上記温度範囲内にあるときはP3に進み、上記温度範囲
内にないときは今回のルーチンを終了する。P3では、空
燃比がλコントロール中であるか否かを判別する。λコ
ントロールとは、空燃比を目標空燃比（例えばλ＝１）
にフィードバック制御していることをいう。したがっ
て、λコントロール中であれば空燃比は論理空燃比近く
に収束し、安定している。λコントロール中であればP4
に進み、λコントロール中でないときは今回のルーチン
を終了する。P4では定常運転であるか否かを判別する。
この判別はエンジンの回転数および負荷等の運転条件が
所定範囲内にあるか否かで行う。定常運転であればP5に
進み、定常運転になければ今回のルーチンを終了する。
P5では定常運転が所定時間以上続いたか否かを判別す
る。この判別は、例えば定常運転状態に入ってからの時
間を判別回路17のマイクロコンピュータの有するカウン
ターで計測することにより行う。定常運転が所定時間以
上継続しているときはP6に進み、所定時間以上継続して
いなければ今回のルーチンを終了する。P6では劣化判別
を行う運転領域であるか否かを判別する。この運転領域
は判別回路17におけるメモリに、例えば第４図に示すテ
ーブルマップの形で記憶されており、上記判別はエンジ
ンの回転数および負荷（トルク）が上記第４図の判別領
域内にあるか否かで行う。判別領域内にあればP7で第４
図のテーブルマップからそのときの触媒の劣化判定値Tm
pngをルックアップし、判別領域内になければ今回のル
ーチンを終了する。First, the operating state of the engine is determined in steps P 1 to P 6 to determine whether or not the state is appropriate for determination of deterioration. That is, it is determined at P 1 whether or not a predetermined time or more has elapsed since the engine was started. This determination is performed, for example, by measuring the time after the ignition key switch of the engine is turned on by the counter of the microcomputer in the determination circuit 17. When more than a predetermined period of time has elapsed after the start, the process proceeds to P 2, when not yet elapsed and ends the current routine. Temperature Tw of P 2 in the cooling water, it is determined whether or not within a predetermined temperature range. This temperature range is, for example, 80 ° C. <Tw <100 ° C. If the temperature of the cooling water is within this temperature range, it means that the engine is not cooling and is not overheated. Cooling water temperature Tw
There when in the above temperature range, the process proceeds to P 3, when not in the temperature range ends the current routine. In P 3, the air-fuel ratio it is determined whether or not being λ control. λ control is the air-fuel ratio that is the target air-fuel ratio (for example, λ = 1)
Feedback control. Therefore, during λ control, the air-fuel ratio converges close to the logical air-fuel ratio and is stable. P 4 if λ is in control
If it is not under λ control, this routine ends. At P 4 , it is determined whether or not the operation is steady.
This determination is made based on whether or not operating conditions such as the engine speed and load are within a predetermined range. If it is a steady operation, proceed to P5, and if it is not a steady operation, end this routine.
Steady operation at P 5, it is determined whether or not followed by a predetermined time or more. This determination is performed, for example, by measuring the time from the start of the steady operation state with a counter included in the microcomputer of the determination circuit 17. When the steady operation is continued for a predetermined time or more, the process proceeds to P 6, the present routine is ended unless continues for a predetermined time or longer. And it determines whether the operation region to perform P 6 in deterioration determining. This operating region is stored in the memory of the discriminating circuit 17 in the form of, for example, the table map shown in FIG. Or not. If it is in the discrimination area, the fourth with P 7
From the table map in the figure, the catalyst deterioration judgment value Tm at that time
Look up png and end this routine if it is not in the discrimination area.
ここで、触媒の劣化と触媒温度の関係を第５図に基づ
いて説明する。第５図は排気の流れ方向に沿った触媒内
部の温度分布である。触媒が劣化していない場合は触媒
入口付近で反応が完了するので、実線で示すようにＡ点
で温度がピークになる。触媒が劣化するに従って一点鎖
線や二点鎖線で示すように温度のピークが触媒出口のＢ
点の方向にずれてくる。したがって、Ａ点の温度を測定
することにより触媒の劣化を判別することができるが、
その場合、Ａ点の温度は触媒入口の排気温度によって変
化し、この排気温度はエンジンの特性のばらつき等によ
って差異が生ずるため、Ａ点の温度のみでは劣化の判定
にばらつきが生ずる可能性がある。このため、三元触媒
13の入口部の排気温度の影響を排除する意味から上流側
および下流側の２点で触媒温度を検出し、その差に応じ
て触媒劣化を判別するのが好ましい。２点間の温度を測
定することにより触媒の劣化を高精度に判別することが
できるからである。Here, the relationship between catalyst deterioration and catalyst temperature will be described with reference to FIG. FIG. 5 shows the temperature distribution inside the catalyst along the exhaust flow direction. When the catalyst is not deteriorated, the reaction is completed near the catalyst inlet, so that the temperature peaks at point A as shown by the solid line. As the catalyst deteriorates, the temperature peaks at the catalyst outlet B as shown by the one-dot chain line and the two-dot chain line.
It shifts in the direction of the point. Therefore, the deterioration of the catalyst can be determined by measuring the temperature at the point A.
In that case, the temperature at the point A changes depending on the exhaust temperature at the catalyst inlet, and the exhaust temperature varies due to variations in engine characteristics and the like. Therefore, there is a possibility that the determination of deterioration may occur only at the temperature at the point A. . Therefore, the three-way catalyst
In order to eliminate the influence of the exhaust gas temperature at the inlet of 13, it is preferable to detect the catalyst temperature at two points on the upstream side and the downstream side, and determine the catalyst deterioration according to the difference. This is because the deterioration of the catalyst can be accurately determined by measuring the temperature between the two points.
そこで、本実施例では、運転条件に応じて触媒の劣化
温度を予め実験により求め、これを劣化判定値Tmpngと
して例えば第４図に示すテーブルマップの形で判別回路
17におけるメモリに格納し、温度センサ21、22により検
出される２点の触媒温度の差を劣化判定値Tmpngと比較
することで、触媒の劣化を容易に判別可能としている。Therefore, in the present embodiment, the deterioration temperature of the catalyst is obtained in advance by experiments according to the operating conditions, and this is used as the deterioration judgment value Tmpng, for example, in the form of a table map shown in FIG.
The deterioration of the catalyst can be easily discriminated by storing it in the memory of 17 and comparing the difference between the catalyst temperatures at the two points detected by the temperature sensors 21 and 22 with the deterioration judgment value Tmpng.
再び、第３図に示すプログラムに戻り、P8で実際の触
媒温度差Tcatを劣化判定値Tmpngと比較し、Tcat≧Tmpng
のときは三元触媒13が劣化していないと判断してルーチ
ンを終了し、Tcat＜Tmpngのときは劣化していると判断
してP9で警報灯19を点灯して運転者に警告する。これに
より、運転者は三元触媒13の劣化を直接的に知ることが
でき、その後の適切な処置、例えば整備工場で三元触媒
13の交換を直ちに行う等の対策を採ることができる。そ
の結果、三元触媒13の異常に伴う悪影響を最小限とする
ことができ、運転性の向上、公害防止に大きく寄与す
る。Again, returning to the program shown in FIG. 3, the actual catalyst temperature difference Tcat is compared with the deterioration determination value Tmpng at P 8 , and Tcat ≧ Tmpng
When it is, it is judged that the three-way catalyst 13 is not deteriorated and the routine is ended. When Tcat <Tmpng, it is judged that it is deteriorated and the warning light 19 is turned on at P 9 to warn the driver. . This allows the driver to directly know the deterioration of the three-way catalyst 13, and then take appropriate measures, for example, at the maintenance shop.
Measures such as immediate replacement of 13 can be taken. As a result, the adverse effect due to the abnormality of the three-way catalyst 13 can be minimized, which greatly contributes to the improvement of drivability and the prevention of pollution.
（効果） 本発明によれば、触媒コンバータ内の上流側および下
流側に位置する複数箇所の触媒温度の差を検出し、その
温度差と運転状態に基づいて設定する触媒の劣化判定値
とに基づいて触媒の劣化を判別しているので、触媒の劣
化を直接的に検知することができる。(Effect) According to the present invention, the difference between the catalyst temperatures at a plurality of locations located upstream and downstream in the catalytic converter is detected, and the deterioration determination value of the catalyst is set based on the temperature difference and the operating state. Since the deterioration of the catalyst is determined based on the above, the deterioration of the catalyst can be directly detected.
第１図は本発明の基本概念図、第２〜５図は本発明に係
る触媒の劣化検知装置の一実施例を示す図であり、第２
図はその全体構成図、第３図はその触媒の劣化を判別す
るプログラムを示すフローチャート、第４図はその触媒
劣化判定の運転領域と劣化判定値との関係を示す図、第
５図はその触媒の劣化と触媒温度の関係を示す図、第６
図は従来の排出ガスの温度検出装置を示すその全体構成
図である。 11……触媒コンバータ、 13……三元触媒、 21、22……温度センサー（触媒温度検出手段）、 17……判別回路（判定値設定手段、劣化判別手段）、 18……運転状態検出手段、 19……警報灯。FIG. 1 is a basic conceptual diagram of the present invention, and FIGS. 2 to 5 are diagrams showing an embodiment of a catalyst deterioration detecting device according to the present invention.
FIG. 4 is an overall configuration diagram, FIG. 3 is a flowchart showing a program for determining deterioration of the catalyst, FIG. 4 is a diagram showing a relationship between an operating region of the catalyst deterioration determination and a deterioration determination value, and FIG. FIG. 6 is a graph showing the relationship between catalyst deterioration and catalyst temperature,
FIG. 1 is an overall configuration diagram showing a conventional exhaust gas temperature detecting device. 11 …… Catalyst converter, 13 …… Three-way catalyst, 21,22 …… Temperature sensor (catalyst temperature detection means), 17 …… Discrimination circuit (judgment value setting means, deterioration discrimination means), 18 …… Operating state detection means , 19 ... Warning light.
Claims (1)
側に位置する複数箇所の触媒の温度をそれぞれ検出する
触媒温度検出手段と、 ｂ）エンジンの運転状態を検出する運転状態検出手段
と、 ｃ）運転状態検出手段の出力に基づいて触媒の劣化判定
値を設定する判定値設定手段と、 ｄ）触媒温度検出手段から出力される前記複数箇所の検
出温度の差および判定値設定手段の出力に基づいて触媒
の劣化を判別する劣化判別手段と、 を備えたことを特徴とする触媒の劣化検知装置。1. A catalyst temperature detecting means for respectively detecting temperatures of a plurality of catalysts located upstream and downstream in a catalytic converter; b) operating state detecting means for detecting an operating state of an engine; c) judgment value setting means for setting a deterioration judgment value of the catalyst based on the output of the operating state detecting means, and d) difference between the detection temperatures output from the catalyst temperature detecting means and output of the judgment value setting means. A deterioration detecting device for a catalyst, comprising: deterioration determining means for determining deterioration of the catalyst based on the above.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63175462A JP2557477B2 (en) | 1988-07-13 | 1988-07-13 | Catalyst deterioration detector |
| US07/379,134 US5060473A (en) | 1988-07-13 | 1989-07-13 | System for detecting deterioration of catalyst in catalytic converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63175462A JP2557477B2 (en) | 1988-07-13 | 1988-07-13 | Catalyst deterioration detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0227109A JPH0227109A (en) | 1990-01-29 |
| JP2557477B2 true JP2557477B2 (en) | 1996-11-27 |
Family
ID=15996487
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63175462A Expired - Lifetime JP2557477B2 (en) | 1988-07-13 | 1988-07-13 | Catalyst deterioration detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2557477B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2876544B2 (en) * | 1990-09-05 | 1999-03-31 | 本田技研工業株式会社 | Catalyst temperature sensor deterioration detection device |
| US5236135A (en) * | 1991-05-23 | 1993-08-17 | Ecomed, Inc. | Medical waste treatment system |
| WO1994004800A1 (en) * | 1992-08-17 | 1994-03-03 | Emitec Gesellschaft Für Emissionstechnologie Mbh | Process for monitoring the operation of a catalytic converter |
| DE19963903A1 (en) * | 1999-12-31 | 2001-07-12 | Bosch Gmbh Robert | Method for operating an internal combustion engine, in particular a motor vehicle |
| JP2002202112A (en) * | 2000-11-06 | 2002-07-19 | Fujitsu Ltd | Shape measuring apparatus |
| DE102006016906A1 (en) * | 2006-04-11 | 2007-10-25 | Daimlerchrysler Ag | Device for monitoring an exhaust gas catalyst in the exhaust system of an internal combustion engine |
| JP6780763B2 (en) * | 2018-12-25 | 2020-11-04 | トヨタ自動車株式会社 | Internal combustion engine control device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49111020A (en) * | 1973-02-26 | 1974-10-23 | ||
| JPS5081099A (en) * | 1973-11-14 | 1975-07-01 | ||
| DE2643739C2 (en) * | 1976-09-29 | 1986-03-13 | Robert Bosch Gmbh, 7000 Stuttgart | Method for monitoring the activity of catalytic converters for exhaust gas purification |
| JPS6261919U (en) * | 1985-10-07 | 1987-04-17 |
-
1988
- 1988-07-13 JP JP63175462A patent/JP2557477B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0227109A (en) | 1990-01-29 |
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