JPS63111274A - Diagnostic method for trouble of exhaust gas recirculation control device - Google Patents
Diagnostic method for trouble of exhaust gas recirculation control deviceInfo
- Publication number
- JPS63111274A JPS63111274A JP61259432A JP25943286A JPS63111274A JP S63111274 A JPS63111274 A JP S63111274A JP 61259432 A JP61259432 A JP 61259432A JP 25943286 A JP25943286 A JP 25943286A JP S63111274 A JPS63111274 A JP S63111274A
- Authority
- JP
- Japan
- Prior art keywords
- valve
- egr
- negative pressure
- exhaust gas
- intake pressure
- 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.)
- Pending
Links
- 238000002405 diagnostic procedure Methods 0.000 title 1
- 238000001514 detection method Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 22
- 238000003745 diagnosis Methods 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/52—Systems for actuating EGR valves
- F02M26/55—Systems for actuating EGR valves using vacuum actuators
- F02M26/56—Systems for actuating EGR valves using vacuum actuators having pressure modulation valves
- F02M26/57—Systems for actuating EGR valves using vacuum actuators having pressure modulation valves using electronic means, e.g. electromagnetic valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/49—Detecting, diagnosing or indicating an abnormal function of the EGR system
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Exhaust-Gas Circulating Devices (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、主として自動車のエンジンに適用される排気
還流制御装置の故障診断方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a failure diagnosis method for an exhaust gas recirculation control device mainly applied to an automobile engine.
［従来の技術］
一般に、自動車用エンジンでは、吸気系と排気系とを排
気還流通路（以後、ＥＧＲ通路と称する）を介して連通
させるとともに、このＥＧＲ通路を介して排気ガスの一
部を吸気系に還流することにより、燃料の最高燃焼温度
を抑制し、排気ガス中に含まれるＮＯｘの生成を低減す
る、いわゆるＥＧＲ制御を行うようにしている。その際
、エンジン運転中、絶えず排気ガスを吸気系に還流する
のではなく、ＥＧＲ通路に介設した排気還流制御バルブ
（以後、ＥＧＲバルブと称する）の作動をエンジンの運
転状況に応じて制御することにより、ＥＧＲを実行する
時期、およびＥＧＲ量を制御するようにしている。例え
ば、燃料の燃焼状態が良好でなく、ＮＯｘの生成も比較
的少ないエンジンの低負荷領域では、ＥＧＲを止めるよ
うにしており、また、ＥＧＲを施す場合は、吸気中に含
まれる排気ガスが略一定比率となるようにそのＥＧＲ量
を制限しているのが通常である。[Prior Art] Generally, in an automobile engine, an intake system and an exhaust system are communicated through an exhaust gas recirculation passage (hereinafter referred to as an EGR passage), and a portion of the exhaust gas is transferred to the intake air through this EGR passage. By circulating the fuel into the system, so-called EGR control is performed, which suppresses the maximum combustion temperature of the fuel and reduces the generation of NOx contained in the exhaust gas. At this time, instead of constantly recirculating exhaust gas to the intake system during engine operation, the operation of an exhaust gas recirculation control valve (hereinafter referred to as the EGR valve) installed in the EGR passage is controlled according to the engine operating conditions. By doing so, the timing at which EGR is executed and the amount of EGR are controlled. For example, in low engine load ranges where the fuel combustion is not good and NOx generation is relatively low, EGR is stopped, and when EGR is applied, the exhaust gas contained in the intake air is Normally, the EGR amount is limited to a constant ratio.
ところが、ＥＧＲバルブや該バルブの作動をエンジンの
低負荷領域で直接的に制御する装置やＩＥＧＲバルブ自
体の作動誤差あるいは作動不良等に起因して所期のＥＧ
Ｒ制御が行われ得ない場合がある。However, due to operational errors or malfunctions of the EGR valve, a device that directly controls the operation of the valve in the low engine load range, or the IEGR valve itself, the intended EGR
There are cases where R control cannot be performed.
かかる不具合を解消するための具体的な先行技術として
は、例えば特開昭５７−２１２３５８号公報に示される
ように、ＥＧＲバルブの作動位置を直接検出することに
より、ＥＧＲバルブの故障診断を行うようにしている例
がある。As a specific prior art for solving this problem, for example, as shown in Japanese Unexamined Patent Application Publication No. 57-212358, there is a method for diagnosing the failure of the EGR valve by directly detecting the operating position of the EGR valve. There are examples of this.
［発明が解決しようとする問題点］
しかしながら、前記先行技術では、ＥＧＩ？バルブの作
動位置を検出するための格別な装置を設ける必要がある
ことや、この装置から送られる情報を処理する制御回路
等を含めたシステム構造が複雑となり、好ましいとはい
えない。[Problems to be Solved by the Invention] However, in the prior art, EGI? This is not desirable because it requires a special device to detect the operating position of the valve, and the system structure including a control circuit for processing information sent from this device is complicated.
本発明は、比較的容易にＥＧＲバルブの故障を発見し、
運転者等に知らせることにより、前述した問題点を解消
することのできる排気還流制御装置の故障診断方法を提
供することを目的としている。The present invention relatively easily discovers EGR valve failure,
It is an object of the present invention to provide a fault diagnosis method for an exhaust gas recirculation control device that can solve the above-mentioned problems by notifying the driver and the like.
［問題点を解決するための手段］
本発明は、上記目的を達成するために、ＥＧＲバルブに
吸気圧を導く負圧通路に前記ＥＧＧ？バルブの作動を制
御する負圧切換弁を介設し、この負圧切換弁をＥＧＲ実
行中でエンジン負荷が安定状態にあることを条件として
一時的に切換えるとともに、その切換前後の吸気圧が一
定範囲内にあるか否かを検出し、その検出結果に基づい
てＥＧＲ系が故障か否かを判定するようにしたことを特
徴とする。[Means for Solving the Problems] In order to achieve the above object, the present invention provides the EGG valve in the negative pressure passage that guides intake pressure to the EGR valve. A negative pressure switching valve is installed to control the operation of the valve, and this negative pressure switching valve is temporarily switched when EGR is in progress and the engine load is stable, and the intake pressure is constant before and after switching. It is characterized in that it detects whether or not it is within the range, and determines whether or not the EGR system is malfunctioning based on the detection result.
［作用］
エンジン負荷が安定状態にある場合にＥＧＲを施すと、
ＥＧＲバルブが正常な作動状態にあれば、吸気圧が比較
的大きく変動する。そこで、負圧通路に介設されＥＧＲ
バルブの作動を制御する負圧切換弁をＥＧＲ実行中に一
時的に切換えてＥＧＲを停止させるとともに、その切換
前後の吸気圧が一定範囲内にあるか否かを検出すれば、
吸気圧の変化量によりＥＧＲ系が正常に作動しているか
否かを判定することができる。すなわち、吸気圧の変化
量が小さく一定範囲内にあればＥＧＲ系の故障判定を行
い、吸気圧の変化量が上記一定範囲量を上回っていれば
ＩＥＧＲ系の正常判定が行われる。[Effect] When EGR is applied when the engine load is stable,
If the EGR valve is in a normal operating state, the intake pressure will fluctuate relatively greatly. Therefore, EGR is installed in the negative pressure passage.
If the negative pressure switching valve that controls valve operation is temporarily switched during EGR execution to stop EGR, and if it is detected whether the intake pressure before and after switching is within a certain range,
It can be determined whether the EGR system is operating normally based on the amount of change in the intake pressure. That is, if the amount of change in intake pressure is small and within a certain range, it is determined that the EGR system is malfunctioning, and if the amount of change in intake pressure exceeds the above-mentioned certain range, it is determined that the IEGR system is normal.
［実施例コ 以下、本発明の一実施例を図面を参照して説明する。[Example code] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
第１図は、自動車用エンジンを概略的に示したもので、
図面において１はエンジン本体を示し、２はエンジン本
体１の燃焼室３に連通ずる吸気通路、４は排気通路を示
している。吸気通路２のスロットルボディ５と吸気管６
との間には吸気脈動を防止するサージタンク７を配設し
である。そして、このサージタンク７内と排気通路４内
とをＥＧ１？通路８を介して連通させるとともに、この
ＥＧＲ通路８に、大気圧と吸気圧ＰＭとの差圧により作
動するＩＥＧＲバルブ９を介設しである。ＩＥＧＲバル
ブ９はエンジンの運転状況に応じたバルブ開成により、
排気通路４内の排気ガスの一部を吸気通路２に介設した
前記サージタンク７内に導くためのもので、その負圧室
９ａとスロットルバルブ１０付近のＥＣ１？ポート１１
とを負圧通路１２を介して連通させ該負圧室９ａに吸気
圧ＰＭが導入されるようになっている。そして、この負
圧室９ａとダイヤフラムを隔てて設けられた大気側の定
圧室９ｂとの差圧がＥＧＲバルブ９の作動圧を上回ると
弁体９Ｃが開成し排気通路４内の排気ガスを吸気量に応
じてサージタンク７内に還流するように設定しである。Figure 1 schematically shows an automobile engine.
In the drawings, 1 indicates an engine body, 2 an intake passage communicating with a combustion chamber 3 of the engine body 1, and 4 an exhaust passage. Throttle body 5 and intake pipe 6 of intake passage 2
A surge tank 7 is provided between the pump and the pump to prevent intake pulsation. Then, the inside of this surge tank 7 and the inside of the exhaust passage 4 are connected to EG1? They are communicated through a passage 8, and an IEGR valve 9, which is operated by a pressure difference between atmospheric pressure and intake pressure PM, is interposed in this EGR passage 8. The IEGR valve 9 opens according to the engine operating conditions.
This is for guiding a part of the exhaust gas in the exhaust passage 4 into the surge tank 7 interposed in the intake passage 2, and the negative pressure chamber 9a and the EC1? port 11
are communicated with each other via the negative pressure passage 12, so that the intake pressure PM is introduced into the negative pressure chamber 9a. When the pressure difference between the negative pressure chamber 9a and the constant pressure chamber 9b on the atmospheric side provided across the diaphragm exceeds the operating pressure of the EGR valve 9, the valve body 9C opens and the exhaust gas in the exhaust passage 4 is taken in. It is set so that it flows back into the surge tank 7 depending on the amount.
一方、前記負圧通路１２には、上記Ｅ訃バルブ９の作動
をエンジン負荷に応じて制御するための負圧切換弁１３
を介設しである。負圧切換弁１３は外気中と吸気通路２
内とに選択的に接続し得るように構成されたバキュウム
スイッチングタイプの三方切換弁であり、具体的には、
第１の入力ポート１３ａを前記ＩＥＧＲＥＣ１ポート１
１続し、第２の入力ポート１３ｂをフィルタを介して外
気中に開放し、出力ポート１３ｃを前記ＥＧＲバルブ９
の負圧室９ａ側に接続している。そして、ＥＧＲ′実行
領域で、その電気入力端子に通電が行われていない場合
には、吸気圧側に保持されて前記第１の入力ポート１３
ａと出力ポート１３ｃとが連通し、ＥＧＲ実行領域外で
電気入力端子に通電がなされた場合には、大気圧側に切
換って前記第２の入カポ−）１３ｂと出力ポート１３ｃ
とが連通し、負圧室９ａへの吸気圧ＰＭの導入を遮断し
てｌｌ″ＯＲバルブ９が作動しないように構成されてい
る。On the other hand, the negative pressure passage 12 has a negative pressure switching valve 13 for controlling the operation of the E-valve 9 according to the engine load.
There is no intervention. The negative pressure switching valve 13 is connected to the outside air and the intake passage 2.
It is a vacuum switching type three-way valve configured to be able to selectively connect to the inside and outside.
The first input port 13a is the IEGREC1 port 1.
The second input port 13b is connected to the outside air through a filter, and the output port 13c is connected to the EGR valve 9.
It is connected to the negative pressure chamber 9a side. When the electric input terminal is not energized in the EGR' execution region, the first input port 13 is held on the intake pressure side.
a and the output port 13c communicate with each other, and when the electric input terminal is energized outside the EGR execution area, the pressure is switched to the atmospheric pressure side and the second input port 13b and the output port 13c are connected.
are in communication with each other to block the introduction of intake pressure PM into the negative pressure chamber 9a so that the ll''OR valve 9 does not operate.
また、上記負圧切換弁１３とＥＧＲバルブ９との間の負
圧通路１２には、ＥＧＲモジュレータ１４を配設し、Ｅ
ＧＲバルブ９上流側のＥＧＲ通路８内の排気圧を利用し
て前記ＥＧＲバルブ９の負圧室９ａへ導入される吸気圧
ＰＭが調整されるようにしである。In addition, an EGR modulator 14 is disposed in the negative pressure passage 12 between the negative pressure switching valve 13 and the EGR valve 9.
The exhaust pressure in the EGR passage 8 on the upstream side of the GR valve 9 is used to adjust the intake pressure PM introduced into the negative pressure chamber 9a of the EGR valve 9.
他方、前記サージタンク７側には、吸気圧１）Ｍを検出
する吸気圧センサ１５が設けられている。吸気圧センサ
１５は圧力検出領域を切換える切換弁１６を介して外気
中とサージタンク７内とに選択的に接続し得るようにな
っている。具体的には、切換弁１６は前記負圧切換弁１
３と略同様なバキュウムスイッチングタイプの三方切換
弁からなり、第１の入力ポート１６ａを前記サージタン
ク７内に連通させるとともに、第２の人力ポート１６ｂ
をフィルタを介して外気中に開放し、出力ポート１６ｃ
を前記吸気圧センサ１５に接続している。On the other hand, an intake pressure sensor 15 is provided on the surge tank 7 side to detect the intake pressure 1)M. The intake pressure sensor 15 can be selectively connected to the outside air and the inside of the surge tank 7 via a switching valve 16 that switches the pressure detection area. Specifically, the switching valve 16 is the negative pressure switching valve 1.
3, the first input port 16a communicates with the inside of the surge tank 7, and the second manual port 16b communicates with the inside of the surge tank 7.
is opened to the outside air through a filter, and the output port 16c
is connected to the intake pressure sensor 15.
そして、その電気入力端子に通電が行われていない場合
には、吸気圧ＰＭ側に保持されて前記第１の入力ポート
１６ａと出力ポート１６ｃとが連通し、電気入力端子に
通電がなされた場合には、大気圧側に切換って前記第２
の入力ポート１６ｂと出力ポート１６ｃとが連通ずるよ
うに構成されている。When the electrical input terminal is not energized, the intake pressure is maintained at the PM side and the first input port 16a and the output port 16c are communicated, and when the electrical input terminal is energized, the first input port 16a and the output port 16c are connected. In this case, switch to the atmospheric pressure side and
The input port 16b and the output port 16c are configured to communicate with each other.
マイクロコンピュータシステム１７は、各種センサ等か
らの情報をもとに、エンジンの運転状況に応じて種々の
制御をするためのもので、中央演算処理装置１８と、メ
モリ１９と、人・出力インターフェース２０．２１とを
備えている。そして、人力インターフェース２０に少な
くともスロットルバルブ１０の開度を検出するスロット
ルセンサ２２からの信号ａと、エンジンの冷却水温を検
出する水温センサ２３からの信号すと、ディストリビュ
ータ２４に設けられた回転数センサ（図示せず）からの
信号Ｃと、吸気圧センサ１５からの信号ｄとがそれぞれ
入力され、出力インターフェース２１からは、負圧切換
弁１３と、切換弁１６と、ＥＧＲ装置の故障診断結果を
表示するダイアグランプ２５に向けてそれぞれ信号ｅ、
ｆ、ｇが出力されるようになっている。The microcomputer system 17 is for performing various controls according to the operating conditions of the engine based on information from various sensors, etc., and includes a central processing unit 18, a memory 19, and a human/output interface 20. .21. Then, when the human power interface 20 receives at least a signal a from a throttle sensor 22 that detects the opening degree of the throttle valve 10 and a signal from a water temperature sensor 23 that detects the engine cooling water temperature, a rotation speed sensor provided in the distributor 24 is sent. (not shown) and the signal d from the intake pressure sensor 15 are respectively input, and the output interface 21 outputs the failure diagnosis results of the negative pressure switching valve 13, the switching valve 16, and the EGR device. Signals e, respectively towards the diagram lamp 25 to be displayed.
f and g are output.
そして、上記マイクロコンピュータシステム１７には、
第３図に示すようなプログラムが内蔵させである。まず
、ステップ５１でインクリメントカウンタＣが計測周期
たる一定時間、例えば１２ｍｆｆ１ｓｅｅまでカウント
アツプしたか否かを判断し、カウントアツプしていなけ
ればステップ６３へ進み、経過していればステップ５２
へ進む。ステップ５２では水温センサ２３からの信号す
により、エンジン冷却水温が７０°Ｃに達しているか否
かを判断し、達していなければステップ６２へ進み、７
０°Ｃを上回っていればステップ５３へ進む。The microcomputer system 17 includes:
A program as shown in FIG. 3 is built-in. First, in step 51, it is determined whether the increment counter C has counted up to a certain period of time, for example, 12mff1see, and if the count has not counted up, the process proceeds to step 63, and if it has elapsed, step 52
Proceed to. In step 52, based on the signal from the water temperature sensor 23, it is determined whether the engine cooling water temperature has reached 70°C. If it has not reached 70°C, the process proceeds to step 62, and
If the temperature is higher than 0°C, proceed to step 53.
ステップ５３では、回転数センサからの信号Ｃに基づい
てエンジン回転数ＮＥが一定範囲（３０００〜３２００
回転ｒｐｍ）内か否かを判定し、一定範囲内になければ
ステップ６０へ進み、一定範囲内にあれば、ステップ５
４へ進む。ステップ５４ではスロットルセンサ２２から
の信号ａに基づいてスロットルバルブ１０の開度変化量
１゛Ａが一定値（０，４９ｄｅｇ）より小さいか否かを
判断し、大きければステップ６０へ進み、小さければス
テップ５５へ進み、カウンタＣＤＩＡＣに１を付加した
値をセットしてステップ５６へ進む。ステップ５６では
カウンタＣＤＩＡＧの値が２０に達したか否か、換言す
ればカウンタＣＤＩＡＧがクリアされステップ５５にお
いてカウント開始されてから２４０ ｍｍ５ｅｃ経過し
たか否かを判断し、経過していなければステップ５８へ
進み、経過していればステップ５７へ進んでＥＧＲ用■
Ｓ■すなわち負圧切換弁１３をＯＦＦにする。ステップ
５８では吸気圧センサ１５からの信号ｄに基づいて吸気
圧ＰＭが一定範囲（３００〜３５０ ｍｍｍｍ１ｌ内か
否かを判断し、当該範囲内になければ、ステップ６０へ
進み、一定範囲内であればステップ５つへ進む。ステッ
プ５９では最新の吸気圧１）Ｍを１）Ｍｌにセットして
ステップ６２へ進む。ステップ６０ではカウンタＣＤＩ
ＡＧをクリアしてステップ６１へ進み、負圧切換弁１３
への通電をやめて吸気圧１）ＭをＥＧＩ？バルブ９へ導
き該ＥＧＩｉｌバルブ９を作動させる。ステップ６２で
はインクリメトカウンタＣをクリアしてステップ６３へ
進む。ステップ６３ではカウンタＣＤＩＡＣの値が８０
、換言すればカウンタＣＤＩΔＧの計測開始から９８０
ｍｍ５ｅｃ経過しているか否かを判断し、経過してい
なければステップ５１へ戻り、経過していればステップ
６４へ進む。In step 53, the engine speed NE is set within a certain range (3000 to 3200) based on the signal C from the rotation speed sensor.
If it is not within a certain range, proceed to step 60; if it is within a certain range, proceed to step 5.
Proceed to step 4. In step 54, it is determined based on the signal a from the throttle sensor 22 whether the opening change amount 1''A of the throttle valve 10 is smaller than a certain value (0.49 degrees), and if it is larger, the process proceeds to step 60; The process advances to step 55, where a value obtained by adding 1 to the counter CDIAC is set, and the process advances to step 56. In step 56, it is determined whether or not the value of the counter CDIAG has reached 20. In other words, it is determined whether 240 mm5ec has elapsed since the counter CDIAG was cleared and counting was started in step 55. If not, step 58 Proceed to step 57, and if it has elapsed, proceed to step 57 for EGR ■
In other words, the negative pressure switching valve 13 is turned OFF. In step 58, it is determined whether the intake pressure PM is within a certain range (300 to 350 mmmm1l) based on the signal d from the intake pressure sensor 15. If it is not within the range, the process proceeds to step 60, and whether it is within the certain range or not. If so, the process proceeds to step 5. In step 59, the latest intake pressure 1) M is set to 1) Ml, and the process proceeds to step 62. In step 60, the counter CDI
Clear AG and proceed to step 61, where the negative pressure switching valve 13
Stop energizing and change the intake pressure 1) M to EGI? to valve 9 and actuate the EGIil valve 9. In step 62, the increment counter C is cleared and the process proceeds to step 63. In step 63, the value of counter CDIAC is 80.
In other words, 980 from the start of measurement of counter CDIΔG
It is determined whether or not mm5ec has elapsed. If it has not elapsed, the process returns to step 51; if it has elapsed, the process proceeds to step 64.
ステップ６４ではＥＧＲバルブ９を閉じる直前の吸気圧
ＰＭＩと最新の吸気圧ＰＭ （第２図ではＰＨ１と表示
しである）との差圧が一定値（６０ｍｍｍｍ１ｌ以下か
占かを判断し、一定値以下であればステップ６５へ進み
、ＥＧＲバルブ９等の故障を判定し、一定値を上回って
いると判断した場合はステップ６６へ進み、負圧切換弁
１３への通電を断ってＥＧＲバルブを作動させ、ステッ
プ６７へ進む。ステップ６７ではインクリメントカウン
タＣＤＩＡＣをクリアしてステップ５１へ戻る。In step 64, it is determined whether the differential pressure between the intake pressure PMI immediately before closing the EGR valve 9 and the latest intake pressure PM (indicated as PH1 in FIG. If it is below, the process proceeds to step 65, and a failure of the EGR valve 9, etc. is determined, and if it is determined that the value exceeds a certain value, the process proceeds to step 66, where the power to the negative pressure switching valve 13 is cut off and the EGR valve is activated. The process then proceeds to step 67. In step 67, the increment counter CDIAC is cleared and the process returns to step 51.
このような構成によるとＥＧＲバルブ９等の故障診断を
行う際は、まず水温センサ２３等からの情報により、負
圧切換弁１３を介してＥＧＲバルブ９に吸気圧１）Ｍが
導入されているＥＧＲ実行領域か否かが判定され（ステ
ップ５２）、ＥＧＲ★行領域であれば、さらにエンジン
負荷が安定状態（例えばエンジン回転数ＮＥやスロット
ルバルブ１０の開度変化量ＴＡ、吸気圧ＰＭ等が一定範
囲内）にあるか否かが１２ｍｍ５ｅｃ毎に判定される（
ステップ５１．５３．５４．５８）。そして、これらの
条件が全て満たされていれば、マイクロコンピュータシ
ステム１７から負圧切換弁１３に向けて指令信号ｅが発
せられ（ステップ５９）、負圧切換弁１３では、この信
号ｅにより、第２の人力ポート１３ｂと出力ポート１３
ｃとが連通して負圧通路１２に大気圧が導入されるため
、吸気圧ＰＭがＥＧＲバルブ９の負圧室９ａへ作用しな
くなり、ＩＥＧＲバルブ９が一時的に閉じられる。その
際、ＥＧＲバルブ９が閉じられる直前の吸気圧ＰＭＩが
吸気圧センサ１５からの信号ｄに基づいて記憶されるこ
とになる。そして、エンジン負荷が安定状態に入った時
点から略９６０ ｍｍ５ｅｃ経過した時点で、負圧切換
弁１３への通電が断たれ吸気圧がＥＧＩ？バルブ９に作
用し該バルブ９が開成する直前に計測された吸気正門と
ＥＧＩ？バルブ９が閉じられる直前に計測された吸気圧
１）Ｍｌとの差圧が一定値（６０ｍｍｔ（ｇ）以下であ
ればＥＧＲバルブ９等の故障判定がおこなわれるととも
に、その故障判定結果がダイアグランプ２５に表示され
る（ステップ６４．６５）。According to this configuration, when diagnosing a failure of the EGR valve 9, etc., the intake pressure 1) M is first introduced into the EGR valve 9 via the negative pressure switching valve 13 based on information from the water temperature sensor 23, etc. It is determined whether or not it is in the EGR execution region (step 52), and if it is in the EGR Within a certain range) is determined every 12mm5ec (
Steps 51.53.54.58). If all of these conditions are met, the microcomputer system 17 issues a command signal e to the negative pressure switching valve 13 (step 59), and the negative pressure switching valve 13 uses this signal e to 2 human power port 13b and output port 13
Since atmospheric pressure is introduced into the negative pressure passage 12 through communication with the negative pressure passage 12, the intake pressure PM no longer acts on the negative pressure chamber 9a of the EGR valve 9, and the IEGR valve 9 is temporarily closed. At this time, the intake pressure PMI immediately before the EGR valve 9 is closed is stored based on the signal d from the intake pressure sensor 15. Then, when approximately 960 mm5ec has passed since the engine load entered a stable state, the power to the negative pressure switching valve 13 is cut off and the intake pressure changes to EGI? The intake main gate and EGI? which were measured immediately before the valve 9 was opened by acting on the valve 9? If the differential pressure from the intake pressure 1) Ml measured just before the valve 9 is closed is less than a certain value (60 mmt (g)), a failure determination of the EGR valve 9, etc. will be made, and the failure determination result will be displayed on the diagram. 25 (steps 64 and 65).
なお、以上は故障判定が行われる行程について述べたが
、前述した制御設定条件が満たされず、例えばエンジン
負荷等が安定状態になく、吸気圧１）Ｍが著しく変化す
る領域では上記故障診断は行われないことになる。Although the above has described the process in which a failure determination is performed, the above failure diagnosis is not performed in a region where the control setting conditions described above are not satisfied, for example, the engine load is not in a stable state, and the intake pressure 1) M changes significantly. This means that you will not be able to do so.
以」二の説明からも明らかなように、ＥＧＲ実行領域で
、エンジン回転数ＮＥやスロットルバルブ１０あるいは
吸気圧ＰＭが一定範囲内にあり、エンジン負荷が安定状
態にある際に、負圧切換弁１３を切換えて排気還流を一
時的に停止するとともに、その切換前後の吸気圧ＰＭの
変化量を比較しさえすれば、確実にＩＥＧＲバルブ９笠
の作動状態を判別し、その診断結果を表示させることが
できる。As is clear from the following explanation, in the EGR execution region, when the engine speed NE, throttle valve 10, or intake pressure PM are within a certain range, and the engine load is stable, the negative pressure switching valve is activated. 13 to temporarily stop exhaust gas recirculation and compare the amount of change in intake pressure PM before and after switching, the operating state of IEGR valve 9 can be reliably determined and the diagnostic results displayed. be able to.
そして、本実施例によると、通常、設置される水温セン
サ２３や圧力センサ１５、スロットルセンサ２２、ある
いは負圧切換弁１３等を利用し、故障診断を行うことが
できるため、ＥＧＩ？バルブ９の弁体９ａ等の作動位置
を直接検出するための格別な検出装置を設ける必要もな
く、コストの面からも好都合となる。According to this embodiment, failure diagnosis can be performed using the water temperature sensor 23, pressure sensor 15, throttle sensor 22, negative pressure switching valve 13, etc. that are normally installed. There is no need to provide a special detection device for directly detecting the operating position of the valve body 9a of the valve 9, etc., which is advantageous from a cost perspective.
以上、一実施例に就いて述べたが、本発明は必ずしも上
記実施例に限定されるものではなく、例えば、図示例の
数値等をエンジン特性に応じて変えるようにしてもよい
。Although one embodiment has been described above, the present invention is not necessarily limited to the above embodiment, and for example, the numerical values in the illustrated example may be changed depending on the engine characteristics.
［発明の効果］
以上、詳述したように本発明では、格別な装置を設ける
ことなく、通常、設置される装置を有効に利用するとと
もに、エンジン負荷が安定状態にあることを条件として
排気還流制御バルブの作動を一時的に切換え、その切換
前後の吸気圧の変化量により排気還流制御装置の故障診
断を行うようにしている。そのため、コストの上昇を招
くことなく、排気還流制御装置の作動状態を確実に判別
し正確な診断結果を得ることができる排気還流制御装置
の故障診断方法を提供することができる。[Effects of the Invention] As described in detail above, the present invention effectively utilizes normally installed equipment without providing any special equipment, and provides exhaust gas recirculation on the condition that the engine load is stable. The operation of the control valve is temporarily switched, and a failure diagnosis of the exhaust recirculation control device is performed based on the amount of change in intake pressure before and after the switch. Therefore, it is possible to provide a failure diagnosis method for an exhaust gas recirculation control device that can reliably determine the operating state of the exhaust gas recirculation control device and obtain accurate diagnostic results without causing an increase in cost.
第１図は本発明の一実施例を示すシステム説明図、第２
図は同実施例の制御設定条件を示す図、第３図は同実施
例の制御手順を示すフローチャート図である。
１・・・エンジン本体
２・・・吸気通路
４・・・排気通路
７・・・サージタンク
８・・・排気還流通路（ＩＥＧＲ通路）９・・・排気還
流制御バルブ（ＥＧＲバルブ）１２・・・負圧通路
１３・・・負圧切換弁
１４・・・ＥＧＲモジュレータ
１５・・・吸気圧センサ
１７・・・マイクロコンピュータシステム２２・・・ス
ロットルセンサ
２３・・・水温センサ
２５・・・ダイアグランプFig. 1 is a system explanatory diagram showing one embodiment of the present invention;
The figure shows the control setting conditions of the same embodiment, and FIG. 3 is a flowchart showing the control procedure of the same embodiment. 1... Engine body 2... Intake passage 4... Exhaust passage 7... Surge tank 8... Exhaust recirculation passage (IEGR passage) 9... Exhaust recirculation control valve (EGR valve) 12... - Negative pressure passage 13... Negative pressure switching valve 14... EGR modulator 15... Intake pressure sensor 17... Microcomputer system 22... Throttle sensor 23... Water temperature sensor 25... Diagram lamp
Claims (1)
還流制御バルブの作動を制御する負圧切換弁を介設し、
この負圧切換弁を排気還流実行時でエンジン負荷が安定
状態にあることを条件として一時的に切換えるとともに
、その切換前後の吸気圧が一定範囲内にあるか否かを検
出し、その検出結果に基づいて排気還流系が故障か否か
を判定するようにしたことを特徴とする排気還流制御装
置の故障診断方法。A negative pressure switching valve that controls the operation of the exhaust recirculation control valve is interposed in a negative pressure passage that guides intake pressure to the exhaust recirculation control valve,
This negative pressure switching valve is temporarily switched under the condition that the engine load is stable during exhaust gas recirculation, and it is detected whether the intake pressure before and after switching is within a certain range, and the detection result is 1. A failure diagnosis method for an exhaust gas recirculation control device, characterized in that it is determined whether or not an exhaust gas recirculation system is in failure based on the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61259432A JPS63111274A (en) | 1986-10-28 | 1986-10-28 | Diagnostic method for trouble of exhaust gas recirculation control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61259432A JPS63111274A (en) | 1986-10-28 | 1986-10-28 | Diagnostic method for trouble of exhaust gas recirculation control device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63111274A true JPS63111274A (en) | 1988-05-16 |
Family
ID=17334006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61259432A Pending JPS63111274A (en) | 1986-10-28 | 1986-10-28 | Diagnostic method for trouble of exhaust gas recirculation control device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63111274A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4326351A1 (en) * | 1992-08-05 | 1994-02-10 | Mitsubishi Electric Corp | Fault diagnosis of IC engine exhaust gas recirculation system - detecting pressure change when control valve is operated, and checking whether cooling water temp., air intake temp. or engine oil temp. are above reference for correct operation of sensor |
| US5368005A (en) * | 1992-11-19 | 1994-11-29 | Mitsubishi Denki Kabushiki Kaisha | Apparatus for detecting fault in exhaust gas recirculation control system of internal combustion engine |
| CN114992006A (en) * | 2022-04-14 | 2022-09-02 | 联合汽车电子有限公司 | Flow diagnosis method and device of EGR (exhaust gas Recirculation) system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5467826A (en) * | 1977-11-11 | 1979-05-31 | Automob Antipollut & Saf Res Center | Operation diagnosis system for exhaust gas re-circulation valve |
| JPS6251746A (en) * | 1985-08-31 | 1987-03-06 | Nippon Denso Co Ltd | Exhaust gas recirculation control device |
-
1986
- 1986-10-28 JP JP61259432A patent/JPS63111274A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5467826A (en) * | 1977-11-11 | 1979-05-31 | Automob Antipollut & Saf Res Center | Operation diagnosis system for exhaust gas re-circulation valve |
| JPS6251746A (en) * | 1985-08-31 | 1987-03-06 | Nippon Denso Co Ltd | Exhaust gas recirculation control device |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4326351A1 (en) * | 1992-08-05 | 1994-02-10 | Mitsubishi Electric Corp | Fault diagnosis of IC engine exhaust gas recirculation system - detecting pressure change when control valve is operated, and checking whether cooling water temp., air intake temp. or engine oil temp. are above reference for correct operation of sensor |
| DE4326351C2 (en) * | 1992-08-05 | 2000-06-08 | Mitsubishi Electric Corp | Diagnostic procedures |
| US5368005A (en) * | 1992-11-19 | 1994-11-29 | Mitsubishi Denki Kabushiki Kaisha | Apparatus for detecting fault in exhaust gas recirculation control system of internal combustion engine |
| CN114992006A (en) * | 2022-04-14 | 2022-09-02 | 联合汽车电子有限公司 | Flow diagnosis method and device of EGR (exhaust gas Recirculation) system |
| CN114992006B (en) * | 2022-04-14 | 2024-03-19 | 联合汽车电子有限公司 | Flow diagnosis method and device for EGR (exhaust gas Recirculation) system |
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