JPH11257162A - Egr device of multiple cylinder engine - Google Patents

Egr device of multiple cylinder engine

Info

Publication number
JPH11257162A
JPH11257162A JP10061825A JP6182598A JPH11257162A JP H11257162 A JPH11257162 A JP H11257162A JP 10061825 A JP10061825 A JP 10061825A JP 6182598 A JP6182598 A JP 6182598A JP H11257162 A JPH11257162 A JP H11257162A
Authority
JP
Japan
Prior art keywords
egr
variation
cylinder
rate
degree
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
Application number
JP10061825A
Other languages
Japanese (ja)
Inventor
Koichi Hamaguchi
孝一 濱口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Isuzu Motors Ltd
Original Assignee
Isuzu Motors Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Isuzu Motors Ltd filed Critical Isuzu Motors Ltd
Priority to JP10061825A priority Critical patent/JPH11257162A/en
Publication of JPH11257162A publication Critical patent/JPH11257162A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Exhaust-Gas Circulating Devices (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide an EGR device of a multiple cylinder engine, capable of preventing black smoke from being generated caused by variations in the EGR ratio of the cylinders by controlling an EGR valve, reducing the whole EGR gas amount, and preventing excessive EGR to be generated in a part of cylinders when the variation in the EGR(exhaust gas recirculation) ratio of respective cylinders exceeds the specified variation determining value, in a multiple cylinder engine. SOLUTION: In a multiple cylinder engine, an EGR passage for connecting an exhaust passage of an engine and an intake passage to each other is provided, and an EGR valve 4 for adjusting the EGR gas amount is arranged in this EGR passage. Intake air temperature sensors 11 are provided on respective intake branch passages branched from the intake passage and connected to respective cylinders of the engine, and a controller 9 for inputting detected values of the intake air temperature sensors 11 and controlling the valve opening of the EGR valve 4 is provided.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、ディーゼルエンジ
ンなどにおいて、ＮＯｘの排出量を低減するために、排
気ガスの一部を吸気側に還流するエンジンのＥＧＲ（排
気還流、排気再循環）装置に関するものである。より詳
細には、多気筒エンジンの各気筒（シリンダ）間のＥＧ
Ｒ率の不均等によって発生する黒煙を、全体のＥＧＲ率
を制御して抑制する多気筒エンジンのＥＧＲ装置に関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EGR (exhaust gas recirculation, exhaust gas recirculation) device for a diesel engine or the like that recirculates a part of exhaust gas to an intake side in order to reduce NOx emission. Things. More specifically, the EG between each cylinder (cylinder) of the multi-cylinder engine
The present invention relates to an EGR device for a multi-cylinder engine that suppresses black smoke generated due to an uneven R ratio by controlling the overall EGR ratio.

【０００２】[0002]

【従来の技術】ディーゼルエンジン等の排気ガス対策に
おいて、排気ガス中のＮＯｘ（窒素酸化物）の排出量を
低減するために、不活性ガスである排気ガスの一部、即
ちＥＧＲガスを吸気系に還流することによって燃焼温度
を低く抑えて、ＮＯｘの生成を抑制するＥＧＲ（排気再
循環）が有効であることが知られており、広く実用化さ
れている。2. Description of the Related Art In an exhaust gas countermeasure for a diesel engine or the like, in order to reduce the amount of NOx (nitrogen oxide) contained in the exhaust gas, a part of the exhaust gas as an inert gas, that is, EGR gas is supplied to an intake system. It is known that EGR (exhaust gas recirculation), which suppresses the generation of NOx by suppressing the combustion temperature by recirculating the exhaust gas, is effective, and is widely used.

【０００３】このＥＧＲ装置は、図２に示すように、エ
ンジン１の吸気マニホールド３へ至る吸気通路８と排気
マニホールド２との間をＥＧＲ通路６で接続し、排気系
から排気ガスＧの一部であるＥＧＲガスＧｅを、ＥＧＲ
通路６を経由して吸気通路８の新気Ａに混入して吸気マ
ニホールド３へ還流させてＥＧＲを行っている。このＥ
ＧＲ通路６には、ＥＧＲ率調整用のＥＧＲ弁４が設けて
あり、また、必要に応じて、冷却水通路７を有するＥＧ
Ｒクーラー５を設けてＥＧＲガスＧｅを冷却している。In this EGR device, as shown in FIG. 2, an EGR passage 6 connects an intake passage 8 leading to an intake manifold 3 of the engine 1 and an exhaust manifold 2, and a part of the exhaust gas G from an exhaust system. EGR gas Ge
The EGR is performed by mixing the fresh air A in the intake passage 8 via the passage 6 and returning the mixture to the intake manifold 3. This E
An EGR valve 4 for adjusting the EGR rate is provided in the GR passage 6, and an EGR valve 4 having a cooling water passage 7 as necessary.
An R cooler 5 is provided to cool the EGR gas Ge.

【０００４】そして、エンジン１の燃焼状態を良好に保
ちながらＮＯｘを低減するために、エンジン１の運転状
態に応じて決まるＥＧＲ率を目標に、ＥＧＲ弁４の弁開
度をコントローラ９で調整制御して、ＥＧＲ通路６を通
過するＥＧＲガスＧｅの流量調整を行っている。In order to reduce NOx while keeping the combustion state of the engine 1 good, the controller 9 adjusts and controls the valve opening of the EGR valve 4 with a target of an EGR rate determined according to the operation state of the engine 1. Thus, the flow rate of the EGR gas Ge passing through the EGR passage 6 is adjusted.

【０００５】[0005]

【発明が解決しようとする課題】しかしながら、吸気マ
ニホールド３の形状やＥＧＲ配管６の取り付け位置、吸
排気のタイミング、エンジンの回転速度（ＮＥ）、負荷
（ＬＯＡＤ）、運転の定常・非定常、ＥＧＲ量（ＥＧＲ
率）などの運転条件によって、気筒間のＥＧＲ率がバラ
ツクという現象がある。However, the shape of the intake manifold 3, the mounting position of the EGR pipe 6, the timing of intake and exhaust, the engine speed (NE), the load (LOAD), the steady / unsteady operation, and the EGR Amount (EGR
There is a phenomenon that the EGR rate between cylinders varies depending on operating conditions such as rate.

【０００６】この気筒間のＥＧＲ率のバラツキは、ＥＧ
Ｒ廻りの吸気マニホールドやＥＧＲ配管６の形状や配置
等の仕様が同じであっても、エンジンの運転条件が変化
すると変化し、図３、図４で示すように、中速定常運転
時や高速定常運転時で、各気筒、各吸気ポートにおける
ＥＧＲ率が異なるという実験データが得られている。こ
の各気筒におけるＥＧＲ率のバラツキの原因の一つは、
吸気マニホールド３内のＥＧＲガスＧｅの速度分布の不
均等性によるものであり、この不均等な流れが原因で各
気筒へのＥＧＲガスＧｅの流入量が不均等となる。The variation in the EGR rate between the cylinders is EG
Even if the specifications such as the shape and arrangement of the intake manifold around the R and the EGR pipe 6 are the same, it changes when the operating conditions of the engine change, and as shown in FIGS. Experimental data has been obtained indicating that the EGR rates in the respective cylinders and the respective intake ports are different during the steady operation. One of the causes of the variation in the EGR rate in each cylinder is as follows.
This is due to the unevenness of the speed distribution of the EGR gas Ge in the intake manifold 3, and the uneven flow causes the inflow of the EGR gas Ge into each cylinder to be uneven.

【０００７】また、もう一つの原因として、気筒間の吸
気弁の開閉のタイミングによる吸気干渉がある。この吸
気干渉は、共通の吸気マニホールドを有する多気筒エン
ジンにおいて、ある気筒が吸気を始めると負圧波が発生
し、この負圧波が他の気筒の吸気弁が閉じつつある所に
到達すると、入口圧力を下げたのと同じ効果を生じるの
で、これによって各気筒毎に吸気量が変化し、各気筒間
の体積効率自体もバラツクつくことになる。Another cause is intake interference due to the timing of opening and closing of intake valves between cylinders. In a multi-cylinder engine having a common intake manifold, this intake interference causes a negative pressure wave to occur when a certain cylinder starts intake, and when the negative pressure wave reaches a position where the intake valve of another cylinder is closing, the inlet pressure is reduced. As a result, the amount of intake air changes for each cylinder, and the volumetric efficiency itself between the cylinders also varies.

【０００８】そして、この各気筒間の不均等なＥＧＲ率
のために、エンジンの運転条件によって、各気筒間のＥ
ＧＲ率が偏り一部の気筒のＥＧＲ率が過度に高くなっ
て、その気筒の燃焼状態が悪化して黒煙が著しく発生す
るという問題がある。つまり、図６で示すように、気筒
間のＥＧＲ率のバラツキが大きくなると黒煙の発生量が
多くなり、更に、ＥＧＲ率が増加すると、同じバラツキ
でも相対的にＥＧＲ量が増えるため、黒煙の発生量がよ
り多くなるという実験データが得られている。[0008] Because of the uneven EGR rate between the cylinders, the EGR between the cylinders depends on the operating conditions of the engine.
There is a problem that the GR rate is biased and the EGR rate of some cylinders becomes excessively high, so that the combustion state of the cylinder deteriorates and black smoke is remarkably generated. That is, as shown in FIG. 6, when the variation in the EGR rate between the cylinders increases, the amount of black smoke generated increases, and when the EGR rate increases, the EGR amount relatively increases even with the same variation. Experimental data have shown that the amount of generation of odor increases.

【０００９】しかしながら、現時点においては、気筒間
のＥＧＲ率のバラツキを検出して、一部の気筒に過度の
ＥＧＲが発生するのを防止しているＥＧＲ装置は見当た
らない。類似した装置として、実開平３−２５８４８号
公報に、各気筒毎の吸気枝管と排気枝管と、排気合流管
と各吸気枝管を接続する排気還流管と、排気還流枝管を
設けて、各排気枝管に配設した排気温度センサの検出信
号に基づいて、各排気還流枝管に配設した各気筒用の排
気還流弁を制御して、各気筒毎に排気還流量を変えて、
エンジン始動時の暖機を各気筒毎に行って、始動性を良
くすると共に白煙の発生を防止する多気筒エンジンの排
気還流装置が提案されている。However, at present, there is no EGR device that detects variation in the EGR rate between the cylinders and prevents the occurrence of excessive EGR in some of the cylinders. As a similar device, Japanese Unexamined Utility Model Publication No. 3-25848 discloses an intake branch pipe and an exhaust branch pipe for each cylinder, an exhaust recirculation pipe connecting the exhaust merging pipe and each intake branch pipe, and an exhaust recirculation branch pipe. On the basis of the detection signal of the exhaust gas temperature sensor arranged in each exhaust branch pipe, the exhaust gas recirculation valve for each cylinder arranged in each exhaust gas recirculation branch pipe is controlled to change the exhaust gas recirculation amount for each cylinder. ,
2. Description of the Related Art An exhaust gas recirculation system for a multi-cylinder engine has been proposed which warms up at the time of starting an engine for each cylinder to improve startability and prevent generation of white smoke.

【００１０】しかし、この排気還流装置は、始動時の各
気筒毎の暖機を目的とした排気還流に関する装置である
上に、各気筒毎に設ける排気還流弁と配管数が多くな
り、各排気還流弁を制御する必要があるので、装置や制
御が複雑になり、重量及び配置スペースも増加するので
レイアウト上の問題が発生し、しかも、高コストとなる
という問題がある。However, this exhaust gas recirculation device is a device related to exhaust gas recirculation for the purpose of warming up each cylinder at the time of start-up. In addition, the number of exhaust gas recirculation valves and pipes provided for each cylinder increases, so that Since it is necessary to control the recirculation valve, the apparatus and control become complicated, and the weight and the arrangement space increase, so that there is a problem in that a layout problem occurs and the cost becomes high.

【００１１】しかも、この排気還流装置では、排気枝管
の排気温度によって、各気筒の燃焼状態を検出している
ので、燃料噴射系の噴射量、噴射タイミング、噴射率等
の気筒間のバラツキによる燃焼のバラツキの影響を受け
るので、各気筒のＥＧＲ率を正確に推定できないという
問題がある。本発明は、上述の問題を解決するためにな
されたものであり、その目的は、多気筒エンジンにおい
て、吸気ポートの上流側近傍に配置した吸気温度センサ
により、各気筒のＥＧＲ率を推定して、このＥＧＲ率の
バラツキが所定のバラツキ判定値を越えた時に、ＥＧＲ
弁を制御して全体のＥＧＲガス量を減少して、一部の気
筒に発生する過度のＥＧＲを防止して、気筒間のＥＧＲ
率のバラツキによる黒煙の発生を防止することができる
多気筒エンジンのＥＧＲ装置を提供することにある。Moreover, in this exhaust gas recirculation system, the combustion state of each cylinder is detected based on the exhaust gas temperature of the exhaust branch pipe. There is a problem that the EGR rate of each cylinder cannot be accurately estimated because of the influence of combustion variations. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to estimate an EGR rate of each cylinder by using an intake air temperature sensor arranged near an upstream side of an intake port in a multi-cylinder engine. When the variation in the EGR rate exceeds a predetermined variation determination value, the EGR
The valve is controlled to reduce the total amount of EGR gas to prevent excessive EGR generated in some cylinders, and to reduce EGR between cylinders.
It is an object of the present invention to provide an EGR device for a multi-cylinder engine that can prevent generation of black smoke due to a variation in rate.

【００１２】[0012]

【課題を解決するための手段】以上のような目的を達成
するための多気筒エンジンのＥＧＲ装置は、次のように
構成される。 〔１〕エンジンの排気通路と吸気通路とを連結するＥＧ
Ｒ通路を設けて、該ＥＧＲ通路にＥＧＲガス量を調整す
るＥＧＲ弁を配設した多気筒エンジンにおいて、前記吸
気通路から分岐されエンジンの各気筒に接続される各吸
気枝通路に吸気温度センサを設けると共に、該吸気温度
センサの検出値を入力して、前記ＥＧＲ弁の弁開度を制
御するコントローラを備えたことを特徴とする。The EGR device of the multi-cylinder engine for achieving the above object is constituted as follows. [1] EG connecting the exhaust passage and the intake passage of the engine
In a multi-cylinder engine provided with an R passage and provided with an EGR valve for adjusting an EGR gas amount in the EGR passage, an intake air temperature sensor is provided in each intake branch passage branched from the intake passage and connected to each cylinder of the engine. And a controller for inputting a detection value of the intake air temperature sensor and controlling a valve opening of the EGR valve.

【００１３】この構成により、気筒間のＥＧＲ率を吸気
ポート直前の吸気枝通路に配置した吸気温度センサによ
り推定して、きめ細かいＥＧＲの制御を行うことができ
る。特に、吸気温度センサを使用しているので、噴射系
の気筒間の噴射量、タイミング、噴射率等のバラツキに
よる燃焼のバラツキの影響を受けないというメリットが
ある。With this configuration, the EGR rate between the cylinders can be estimated by the intake air temperature sensor disposed in the intake branch passage immediately before the intake port, and fine EGR control can be performed. In particular, since the intake air temperature sensor is used, there is an advantage that there is no influence from variations in combustion due to variations in injection amount, timing, injection rate, and the like between cylinders of the injection system.

【００１４】その上、ＥＧＲガスを冷却して吸気温度を
下げてＮＯｘ低減効率の向上を図るクールＥＧＲシステ
ムが 実用されつつあるが、軽負荷ではクールＥＧＲは
ＨＣが急増し、吸気温度低下によるＮＯｘ低減効果より
も、このＨＣ悪化の影響が大きいため、ホットＥＧＲへ
の切換が必要であるので、この吸気温度センサを、この
切換条件の判定用として利用できる。In addition, a cool EGR system for cooling the EGR gas to lower the intake air temperature to improve the NOx reduction efficiency is being put into practical use. Since the influence of the deterioration of HC is greater than the reduction effect, it is necessary to switch to the hot EGR. Therefore, the intake air temperature sensor can be used for determining the switching condition.

【００１５】〔２〕更に、前記コントローラは、前記吸
気温度センサの検出値から各気筒毎のＥＧＲ率と、この
ＥＧＲ率のバラツキ度合いを演算する演算手段と、この
演算結果のＥＧＲ率のバラツキ度合いと所定のバラツキ
判定値とを比較する比較判定手段と、この比較判定手段
によって前記演算結果のＥＧＲ率のバラツキ度合いが前
記バラツキ判定値より大きい時に、前記演算結果のＥＧ
Ｒ率のバラツキ度合いが前記バラツキ判定値より小さく
なるまで、前記ＥＧＲ弁の弁開度を減少するように制御
するＥＧＲ弁制御手段とを備えて構成される。[2] Further, the controller calculates an EGR rate for each cylinder and a variation degree of the EGR rate from the detection value of the intake air temperature sensor, and a variation degree of the EGR rate as a result of the calculation. And a predetermined variation determination value. When the degree of variation in the EGR rate of the calculation result is larger than the variation determination value by the comparison determination means, the EG of the calculation result is determined.
EGR valve control means for controlling the EGR valve to reduce the valve opening degree until the degree of variation in the R ratio becomes smaller than the variation determination value.

【００１６】この構成により、気筒間のＥＧＲ率を吸気
枝通路内の吸気ポートの上流近傍に配置した吸気温度セ
ンサにより推定して、このＥＧＲ率のバラツキ度合い、
例えば標準偏差値が所定のバラツキ判定値（バラツキ水
準）を以下の時には、通常のＥＧＲを行い、このＥＧＲ
率のバラツキ度合いが所定のバラツキ判定値を越えた時
には、各気筒におけるＥＧＲ率のバラツキ度合いが大き
いと判断して、ＥＧＲ弁を所定のＥＧＲ減少量分だけ閉
じる方向に制御して全体のＥＧＲガス量を減少して、一
部の気筒に発生する過度のＥＧＲを防止して、気筒間の
ＥＧＲバラツキによる黒煙悪化を防止することができ
る。With this configuration, the EGR rate between the cylinders is estimated by an intake air temperature sensor disposed near the upstream of the intake port in the intake branch passage, and the degree of variation in the EGR rate is determined.
For example, when the standard deviation value is below a predetermined variation determination value (variation level), normal EGR is performed, and this EGR is performed.
When the degree of variation of the rate exceeds a predetermined variation determination value, it is determined that the degree of variation of the EGR rate in each cylinder is large, and the EGR valve is controlled to close by a predetermined amount of EGR reduction to control the overall EGR gas. By reducing the amount, it is possible to prevent excessive EGR generated in some cylinders, and prevent deterioration of black smoke due to EGR variation between cylinders.

【００１７】〔３〕あるいは、前記コントローラは、前
記吸気温度センサの検出値のバラツキ度合いを演算する
演算手段と、この演算結果のバラツキ度合いと所定のバ
ラツキ判定値とを比較する比較判定手段と、この比較判
定手段によって前記検出値のバラツキ度合いが前記バラ
ツキ判定値より大きい時に、前記検出値のバラツキ度合
いが前記バラツキ判定値より小さくなるまで、前記ＥＧ
Ｒ弁の弁開度を減少するように制御するＥＧＲ弁制御手
段と備えて構成する。[3] Alternatively, the controller calculates a variation degree of the detection value of the intake air temperature sensor, a comparison determining means for comparing the variation degree of the calculation result with a predetermined variation determination value, When the variation degree of the detection value is larger than the variation determination value by the comparison determination means, the EG is maintained until the variation degree of the detection value becomes smaller than the variation determination value.
EGR valve control means for controlling so as to decrease the valve opening of the R valve is provided.

【００１８】この構成により、ＥＧＲ率を演算せずに、
吸気温度のレベルで各気筒間のバラツキ度合いを判定す
るので、演算が簡略化できる。With this configuration, without calculating the EGR rate,
Since the degree of variation between the cylinders is determined based on the level of the intake air temperature, the calculation can be simplified.

【００１９】〔４〕更に、別のＥＧＲ弁の制御方法とし
て、前記コントローラは、前記吸気温度センサの検出値
から各気筒のＥＧＲ率を演算する演算手段と、この演算
結果の各気筒のＥＧＲ率と所定のＥＧＲ率上限値とを比
較する比較判定手段と、この比較判定手段によって前記
演算結果の各気筒のＥＧＲ率が前記ＥＧＲ率上限値より
大きい時に、前記演算結果の各気筒のＥＧＲ率が前記Ｅ
ＧＲ率上限値より小さくなるまで、前記ＥＧＲ弁の弁開
度を減少するように制御するＥＧＲ弁制御手段とを備え
て構成する。[4] Further, as another control method of the EGR valve, the controller calculates an EGR rate of each cylinder from a detection value of the intake air temperature sensor, and calculates an EGR rate of each cylinder based on the calculation result. And a predetermined EGR rate upper limit value. When the EGR rate of each cylinder as a result of the calculation is larger than the EGR rate upper limit value, the EGR rate of each cylinder as a result of the calculation is Said E
EGR valve control means for controlling the EGR valve so as to decrease the opening degree of the EGR valve until it becomes smaller than the GR rate upper limit.

【００２０】この構成により、各気筒のＥＧＲ率を確実
に所定のＥＧＲ率上限値以下にすることができる。 〔５〕以上のような構成により、吸気ポートの上流側近
傍に配置した吸気温度センサにより検出した各気筒の吸
気温度から、ＥＧＲ率のバラツキ度合いや吸気温度のバ
ラツキ度合いや各気筒のＥＧＲ率を演算し、所定値と比
較することにより、一部の気筒で過度のＥＧＲが行われ
ると判定した時は、ＥＧＲ弁を所定量や判定が変わるま
で閉じる方向に制御して全体のＥＧＲガス量を低減する
ので、全体のＥＧＲ率が減少して各気筒のＥＧＲ率が下
がり、気筒間のＥＧＲ率のバラツキによって一部の気筒
に生じる過度のＥＧＲが防止される。With this configuration, the EGR rate of each cylinder can be reliably reduced to a predetermined EGR rate upper limit or less. [5] With the configuration described above, the degree of variation in the EGR rate, the degree of variation in the intake temperature, and the EGR rate of each cylinder are determined from the intake temperature of each cylinder detected by the intake temperature sensor disposed near the upstream side of the intake port. When it is determined that excessive EGR is performed in some of the cylinders by calculating and comparing with a predetermined value, the EGR valve is controlled in a closing direction until the predetermined amount or the determination is changed to reduce the total EGR gas amount. As a result, the overall EGR rate is reduced, the EGR rate of each cylinder is reduced, and excessive EGR generated in some cylinders due to variation in the EGR rate between cylinders is prevented.

【００２１】なお、ＥＧＲ率や吸気温度におけるバラツ
キ度合いの所定の判定値と所定のＥＧＲ率上限値は、予
め、エンジンの運転状態に対応して、実験や計算などに
よって求められた数値や関数値であり、比較判定する前
に予め決定されるデータマップや演算プログラムによっ
て算出できるような形でコントローラに入力されて構成
される。The predetermined judgment value of the EGR rate and the degree of variation in the intake air temperature and the predetermined upper limit value of the EGR rate are determined in advance by numerical values or function values obtained by experiments, calculations, etc., corresponding to the operating state of the engine. The data is input to the controller in such a manner that it can be calculated by a data map or a calculation program which is determined before the comparison is determined.

【００２２】また、ここで用いている「吸気」とは、各
気筒に入るガスを示し、詳細にはＥＧＲが行われている
時には新気とＥＧＲガスの混合ガスのことを示し、ＥＧ
Ｒが行われていない時は新気のことを示している。The term "intake" as used herein refers to gas entering each cylinder. More specifically, when EGR is performed, it indicates a mixture of fresh air and EGR gas.
When R is not performed, it indicates freshness.

【００２３】[0023]

【発明の実施の形態】以下、図面を用いて、本発明に係
る多気筒エンジンのＥＧＲ装置の実施の形態を説明す
る。本発明に係る多気筒エンジンのＥＧＲ装置は、図１
に示すように、エンジン１の吸気マニホールド３へ至る
吸気通路８と排気マニホールド２との間をＥＧＲ通路６
で接続し、排気系から排気ガスＧの一部であるＥＧＲガ
スＧｅを、ＥＧＲ通路６を経由して吸気通路８の新気Ａ
に混入して吸気マニホールド３へ還流させてＥＧＲを行
うように構成する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an EGR device for a multi-cylinder engine according to the present invention will be described below with reference to the drawings. An EGR device for a multi-cylinder engine according to the present invention is shown in FIG.
As shown in FIG. 1, an EGR passage 6 extends between the intake passage 8 leading to the intake manifold 3 of the engine 1 and the exhaust manifold 2.
The EGR gas Ge, which is a part of the exhaust gas G, is discharged from the exhaust system via the EGR passage 6 to the fresh air A in the intake passage 8.
And is recirculated to the intake manifold 3 to perform EGR.

【００２４】また、このＥＧＲ通路６には、このＥＧＲ
通路６を通過するＥＧＲガスＧｅの量を調整と開閉弁す
るためのＥＧＲ弁４を設け、更に、ＥＧＲガスＧｅを冷
却するＥＧＲクーラー５を設けて冷却水通路７に冷却水
を循環させるように構成する。The EGR passage 6 is provided with the EGR
An EGR valve 4 for adjusting and opening and closing the amount of the EGR gas Ge passing through the passage 6 is provided, and an EGR cooler 5 for cooling the EGR gas Ge is provided to circulate the cooling water through the cooling water passage 7. Constitute.

【００２５】このＥＧＲ弁４の弁開度の調整及び開閉の
操作を行うために、エンジン１の回転速度ＮＥ、負荷Ｌ
ＯＡＤ等の運転状態を示すデータを図示しない各種セン
サから入力して、予め入力されたＥＧＲ用データマップ
やプログラムにより、運転状態に応じたＥＧＲ率を演算
して、このＥＧＲ率になるように操作信号をＥＧＲ弁４
のアクチュエータに出力してＥＧＲ弁４の弁開度を調整
をするＥＧＲ制御手段を備えたコントローラ９を備えて
構成する。このコントローラ９は、通常はエンジン運転
制御全体を受け持っているエンジンコントローラユニッ
ト（ＥＣＵ）と呼ばれる制御装置９の一部に含まれて構
成される。 そして、各気筒の吸気ポートに入る直前の
吸気温度（Ｔｉ＝Ｔ１〜Ｔ４）を検出するため吸気温度
センサ11を、吸気通路８の吸気マニホールド３の下流側
の各吸気枝通路10に設ける。この吸気温度センサ11には
熱電対などを使用することができる。In order to adjust the opening degree of the EGR valve 4 and open / close the EGR valve 4, the rotational speed NE of the engine 1 and the load L
Data indicating an operation state such as OAD is input from various sensors (not shown), and an EGR rate corresponding to the operation state is calculated based on an EGR data map or a program which is input in advance, and an operation is performed so that the EGR rate becomes equal to the EGR rate. Signal to EGR valve 4
And a controller 9 having EGR control means for outputting to the actuator of the EGR valve 4 to adjust the valve opening degree of the EGR valve 4. The controller 9 is generally included in a part of a control device 9 called an engine controller unit (ECU) that performs overall engine operation control. An intake air temperature sensor 11 for detecting the intake air temperature (Ti = T1 to T4) immediately before entering the intake port of each cylinder is provided in each intake branch passage 10 of the intake passage 8 downstream of the intake manifold 3. A thermocouple or the like can be used for the intake air temperature sensor 11.

【００２６】そして、この吸気温度センサ11の検出値Ｔ
ｉをコントローラ９に入力し、このコントローラ９内
に、検出値である吸気温度ＴｉからＥＧＲ率を演算し、
演算したＥＧＲ率のバラツキ度合い、例えば、標準偏差
値を演算する演算手段を設け、更に、この演算結果のＥ
ＧＲ率のバラツキ度合いと所定のバラツキ判定値とを比
較する比較手段を設けて、この比較手段によって、演算
結果のＥＧＲ率のバラツキ度合いがバラツキ判定値より
大きい時には、演算結果のＥＧＲ率のバラツキ度合いが
バラツキ判定値より小さくなるまで、ＥＧＲ弁の弁開度
を小さく即ち閉じる方向に、ＥＧＲ弁４を調整制御する
ＥＧＲ弁制御手段を備えて構成する。The detected value T of the intake air temperature sensor 11
i is input to the controller 9, and the controller 9 calculates the EGR rate from the detected intake air temperature Ti,
Arithmetic means for calculating the degree of variation of the calculated EGR rate, for example, the standard deviation value, is provided.
Comparing means for comparing the degree of variation of the GR rate with a predetermined variation determination value is provided. When the degree of variation of the EGR rate of the calculation result is greater than the variation determination value, the degree of variation of the EGR rate of the calculation result is determined. EGR valve control means for adjusting and controlling the EGR valve 4 so as to decrease the valve opening of the EGR valve, that is, close the valve until the value becomes smaller than the variation determination value.

【００２７】あるいは、コントローラ９は、吸気温度セ
ンサ11の検出値Ｔｉのバラツキ度合い、例えば、標準偏
差値をを演算する演算手段と、この演算結果のバラツキ
度合いと所定のバラツキ判定値とを比較する比較判定手
段と、この比較判定手段によって検出値のバラツキ度合
いがバラツキ判定値より大きい時に、検出値のバラツキ
度合いがバラツキ判定値より小さくなるまで、ＥＧＲ弁
４の弁開度を減少するように制御するＥＧＲ弁制御手段
と備えて構成する。Alternatively, the controller 9 compares the degree of variation of the detection value Ti of the intake air temperature sensor 11, for example, a standard deviation value, with a computing means for computing the variation degree of the computation result and a predetermined variation determination value. Control means for reducing the valve opening of the EGR valve 4 until the variation of the detected value is smaller than the variation determination value when the variation of the detected value is larger than the variation determination value by the comparison determination means. And EGR valve control means.

【００２８】または、コントローラ９が、吸気温度セン
サ11の検出値Ｔｉから各気筒のＥＧＲ率を演算する演算
手段を有して、この演算結果の各気筒のＥＧＲ率と所定
のＥＧＲ率上限値とを比較判定手段で比較して、各気筒
のＥＧＲ率がＥＧＲ率上限値より大きい時に、各気筒の
ＥＧＲ率がＥＧＲ率上限値より小さくなるまで、ＥＧＲ
弁４の弁開度を減少するように制御するＥＧＲ弁制御手
段とを備えて構成する。Alternatively, the controller 9 has calculating means for calculating the EGR rate of each cylinder from the detection value Ti of the intake air temperature sensor 11, and calculates the EGR rate of each cylinder and the predetermined upper limit of the EGR rate based on the calculation result. Are compared by the comparison determination means. When the EGR rate of each cylinder is larger than the upper limit of the EGR rate, the EGR rate is kept until the EGR rate of each cylinder becomes smaller than the upper limit of the EGR rate.
EGR valve control means for controlling the degree of opening of the valve 4 to decrease.

【００２９】これらの演算手段、比較手段、ＥＧＲ弁制
御手段は、上述のＥＧＲ制御手段と同様に通常はエンジ
ン１の運転やＥＧＲ弁４等を制御するコントローラ９の
一部に含まれて構成される。次に、吸気温度からＥＧＲ
率を導く方法に関して説明する。These calculation means, comparison means, and EGR valve control means are normally included in a part of the controller 9 for controlling the operation of the engine 1, the EGR valve 4, and the like, similarly to the above-described EGR control means. You. Next, from the intake air temperature, EGR
A method for deriving the rate will be described.

【００３０】ＥＧＲを行うと、ＥＧＲガスＧｅが吸気マ
ニホールド３内の新気Ａと混合して混合ガス（Ａ＋Ｇ
ｅ）である吸気の吸気温度Ｔｉが上がるが、この温度上
昇は、ＥＧＲ率が増加して高温のＥＧＲガスＧｅの量が
増加するにつれて大きくなり、吸気温度Ｔｉが高くな
る。そのため、ベンチテスト等の標準空気を使用する新
気温度が一定の時には、運転条件（回転、負荷等）を固
定するとＥＧＲ率と吸気温度Ｔｉの関係は図５に示すよ
うな直線Ｃのような吸気温度Ｔｉの一次関数の関係とな
る。そして、これらの実験等で求めた吸気温度ＴｉとＥ
ＧＲ率の関係に、新気温度の温度変化を考慮した補正を
行うことにより、実車でのＥＧＲ率の推定を行うことが
できる。When the EGR is performed, the EGR gas Ge is mixed with the fresh air A in the intake manifold 3, and the mixed gas (A + G
The intake air temperature Ti of the intake air e) rises, and this temperature rise increases as the EGR rate increases and the amount of the high-temperature EGR gas Ge increases, and the intake air temperature Ti increases. Therefore, when the operating temperature (rotation, load, etc.) is fixed when the fresh air temperature using standard air such as a bench test is constant, the relationship between the EGR rate and the intake air temperature Ti is represented by a straight line C as shown in FIG. The relationship is a linear function of the intake air temperature Ti. Then, the intake air temperatures Ti and E obtained in these experiments and the like are obtained.
By performing a correction in consideration of a change in the fresh air temperature on the relationship between the GR rates, the EGR rate in an actual vehicle can be estimated.

【００３１】この吸気温度ＴｉからＥＧＲ率を推定する
メリットは、噴射系の気筒間の噴射量、タイミング、噴
射率等のバラツキによって発生する燃焼のバラツキの影
響を受けないことである。そして、ＥＧＲ率や吸気温度
におけるバラツキ度合いの所定の判定値と所定のＥＧＲ
率上限値は、予め、エンジンの運転状態に対応して、実
験や計算などによって求められた数値や関数値であり、
比較判定する前に予め決定されるデータマップや演算プ
ログラムによって算出できるような形でコントローラに
入力されて構成される。The merit of estimating the EGR rate from the intake air temperature Ti is that the EGR rate is not affected by variations in combustion generated by variations in injection amount, timing, injection rate, and the like between cylinders of the injection system. Then, a predetermined determination value of the degree of variation in the EGR rate and the intake air temperature and a predetermined EGR
The rate upper limit value is a numerical value or a function value obtained in advance by experiment or calculation in accordance with the operating state of the engine,
The data is input to the controller in a form that can be calculated by a predetermined data map or an arithmetic program before the comparison is determined.

【００３２】以上の構成の多気筒エンジンのＥＧＲ装置
によれば、以下のような運転制御を行うことができるの
で、次のような効果を奏することができる。先ず、ＥＧ
Ｒを行っている時に、吸気温度センサで検出した各気筒
の吸気温度から推定したＥＧＲ率間のバラツキを表す
量、例えば、各ＥＧＲ率をデータとして統計処理した時
の標準偏差値が所定のバラツキ判定値（判定用標準偏差
値）より小さく、ＥＧＲ率間のバラツキが小さいと判断
された時は、エンジン１の運転状態に応じて、予め入力
されているＥＧＲ用データマップやプログラムに従って
設定されるＥＧＲ率のバラツキになるように、コントロ
ーラ９がＥＧＲ弁４の弁開度を調整制御して、所定のＥ
ＧＲ率でＥＧＲを行う。According to the EGR device for a multi-cylinder engine having the above configuration, the following operation control can be performed, and the following effects can be obtained. First, EG
When performing the R, the amount representing the variation between the EGR rates estimated from the intake air temperature of each cylinder detected by the intake air temperature sensor, for example, the standard deviation value when statistically processing each EGR rate as data is a predetermined variation. When it is determined that the difference between the EGR rates is smaller than the determination value (standard deviation value for determination) and the variation between the EGR rates is small, it is set according to an EGR data map or a program that is input in advance according to the operating state of the engine 1. The controller 9 adjusts and controls the valve opening of the EGR valve 4 so that the EGR rate varies, and a predetermined E
EGR is performed at the GR rate.

【００３３】そして、ＥＧＲ率間のバラツキを表す量が
所定のバラツキ判定値より大きくて、ＥＧＲ率のバラツ
キが過大であると判断した時は、コントローラ９がＥＧ
Ｒ弁４の弁開度を所定のＥＧＲ減少量だけ閉じる方向に
制御して、全体のＥＧＲガスＧｅの量を減少してＥＧＲ
量を下げてＥＧＲを行い、ＥＧＲ率のバラツキによって
一部の気筒に発生する過度のＥＧＲとそれに伴う黒煙の
発生を防止する。When the amount representing the variation between the EGR rates is larger than a predetermined variation determination value, and the controller 9 determines that the variation in the EGR rate is excessive, the controller 9 determines whether the variation in the EGR rate is excessive.
The EGR gas Ge is reduced by controlling the valve opening degree of the R valve 4 in a direction to close by a predetermined EGR reduction amount.
EGR is performed with the amount reduced to prevent excessive EGR generated in some cylinders due to variations in the EGR rate and the generation of black smoke accompanying the EGR.

【００３４】更に、このＥＧＲ装置において、ＥＧＲク
ーラー５に冷却水通路７から冷却水を循環してＥＧＲガ
スＧｅを冷却してＥＧＲガス温度を下げＥＧＲガスの体
積を小さくして、新気の吸引効率を上げて燃焼状態を良
好に保ちながら、かつ、吸気温度低下によるＮＯｘ低減
効率の向上を図るクールＥＧＲを行うように制御する。
そして、このクールＥＧＲの実行時に、吸気温度センサ
11の検出値の総和又は平均値が、軽負荷判定温度より低
いことを検出した時には、エンジンが軽負荷運転にある
と判断して、ＥＧＲクーラー５への冷却水の循環を停止
ないし緩慢にして、あるいは、ＥＧＲクーラー５をバイ
パス（図示しない）させてクールＥＧＲからホットＥＧ
Ｒに切り換えるように制御して、クールＥＧＲの軽負荷
運転状態で発生するＨＣの急増を防止する。Further, in this EGR device, cooling water is circulated from the cooling water passage 7 to the EGR cooler 5 to cool the EGR gas Ge, thereby lowering the temperature of the EGR gas, reducing the volume of the EGR gas, and sucking fresh air. The control is performed so as to perform the cool EGR for improving the NOx reduction efficiency due to the decrease in the intake air temperature while maintaining the good combustion state by increasing the efficiency.
When the cool EGR is performed, the intake air temperature sensor
When it is detected that the sum or average of the detected values of 11 is lower than the light load determination temperature, it is determined that the engine is in light load operation, and the circulation of the cooling water to the EGR cooler 5 is stopped or slowed down. Alternatively, the EGR cooler 5 is bypassed (not shown) to change the hot EGR from the cool EGR.
The control is performed so as to switch to R to prevent a rapid increase in HC generated in the light load operation state of the cool EGR.

【００３５】従って、以上の多気筒エンジンのＥＧＲ装
置１によれば、各気筒のＥＧＲ率を吸気ポート直前の吸
気枝通路10に配置した吸気温度センサ11の検出値から推
定して、きめ細かいＥＧＲの制御を行うことができる。
特に、吸気温度センサ11を使用しているので、噴射系の
気筒間の噴射量、タイミング、噴射率等のバラツキによ
って発生する燃焼のバラツキの影響を受けることがな
く、精度よくＥＧＲ率を推定することができる。Therefore, according to the EGR device 1 for a multi-cylinder engine described above, the EGR rate of each cylinder is estimated from the detected value of the intake air temperature sensor 11 disposed in the intake branch passage 10 immediately before the intake port, and the fine EGR rate Control can be performed.
In particular, since the intake air temperature sensor 11 is used, the EGR rate is accurately estimated without being affected by variations in combustion generated by variations in injection amount, timing, injection rate, and the like between cylinders of the injection system. be able to.

【００３６】その上、クールＥＧＲを行う場合におい
て、軽負荷ではクールＥＧＲはＨＣ（炭化水素）が急増
するため、ホットＥＧＲへの切換が必要であるが、この
吸気温度センサ11の検出値Ｔｉをこの切換条件の判定用
として利用することができる。更に、多気筒エンジンに
おいて、気筒間のＥＧＲ率を吸気ポート直前に配置した
吸気温度センサ11により推定して、気筒間のＥＧＲ率の
バラツキが所定のバラツキ水準を越えた時や、吸気温度
Ｔｉのバラツキが所定のバラツキ水準を越えた時や、各
気筒のＥＧＲ率がＥＧＲ率上限値を越えた時には、ＥＧ
Ｒ弁を閉じる方向に制御して、全体のＥＧＲ率を減少し
て各気筒のＥＧＲ率を下げて、ＥＧＲ率のバラツキ、即
ちＥＧＲガス量の偏りによって一部の気筒に発生する過
度のＥＧＲを防止して、それによって、この過度のＥＧ
Ｒによって発生する黒煙の増加を防止することができ
る。In addition, when performing the cool EGR, it is necessary to switch to the hot EGR because the HC (hydrocarbon) in the cool EGR rapidly increases at a light load. It can be used for determining this switching condition. Further, in a multi-cylinder engine, the EGR rate between cylinders is estimated by an intake air temperature sensor 11 disposed immediately before an intake port, and when the variation in the EGR rate between cylinders exceeds a predetermined variation level, or when the intake temperature Ti When the variation exceeds a predetermined variation level or when the EGR rate of each cylinder exceeds the EGR rate upper limit, the EG
By controlling the R valve in the closing direction, the overall EGR rate is reduced to reduce the EGR rate of each cylinder, and the EGR rate variation, that is, the excessive EGR generated in some cylinders due to the bias of the EGR gas amount is reduced. To prevent this excessive EG
An increase in black smoke generated by R can be prevented.

【００３７】[0037]

【発明の効果】以上の説明のように、本発明の多気筒エ
ンジンのＥＧＲ装置によれば、気筒間のＥＧＲ率を吸気
ポートの上流側近傍の吸気枝通路に配置した吸気温度セ
ンサにより推定することができるので、きめ細かいＥＧ
Ｒの制御を行うことができる。特に、吸気温度センサを
使用したことにより、噴射系の気筒間の噴射量、タイミ
ング、噴射率等のバラツキによって発生する燃焼のバラ
ツキの影響を受けることがない。As described above, according to the EGR system for a multi-cylinder engine of the present invention, the EGR rate between cylinders is estimated by the intake air temperature sensor disposed in the intake branch passage near the upstream side of the intake port. EG
R can be controlled. In particular, by using the intake air temperature sensor, there is no influence from the variation in combustion generated due to the variation in the injection amount, the timing, the injection rate, etc. between the cylinders of the injection system.

【００３８】その上、ＥＧＲガスを冷却して吸気温度を
下げてＮＯｘ低減効率の向上を図るクールＥＧＲシステ
ムにおける、軽負荷ではクールＥＧＲはＨＣが急増を避
けるためのホットＥＧＲへの切換への判定用に、この吸
気温度センサの検出値を利用することができる。更に、
気筒間のＥＧＲ率を吸気ポートの上流側近傍に配置した
吸気温度センサにより検出した各気筒の吸気温度から推
定して、各気筒のＥＧＲ率間のバラツキ度合いや各気筒
の吸気温度のバラツキや各気筒のＥＧＲ率が、それぞれ
の所定のバラツキ判定値やＥＧＲ率上限値を越えた時に
ＥＧＲ弁を所定の量だけ閉じる方向に制御して全体のＥ
ＧＲガス量を低減するので、それぞれの気筒のＥＧＲ率
をＥＧＲ率上限値より減少させることができる。In addition, in a cool EGR system in which the EGR gas is cooled to lower the intake air temperature to improve the NOx reduction efficiency, at a light load, the cool EGR is determined to be switched to the hot EGR in order to avoid a rapid increase in HC. For this purpose, the detected value of the intake air temperature sensor can be used. Furthermore,
The EGR rate between the cylinders is estimated from the intake air temperature of each cylinder detected by an intake air temperature sensor arranged near the upstream side of the intake port, and the degree of variation between the EGR rates of each cylinder, the variation of the intake temperature of each cylinder, and the like. When the EGR rate of a cylinder exceeds a predetermined variation determination value or an upper limit value of the EGR rate, the EGR valve is controlled to close by a predetermined amount so that the overall EGR rate is reduced.
Since the GR gas amount is reduced, the EGR rate of each cylinder can be reduced below the EGR rate upper limit.

【００３９】従って、気筒間のＥＧＲ率のバラツキによ
って生じる一部の気筒の過度のＥＧＲを防止して、エン
ジンの燃焼状態を良好に保つことができるので、この過
度のＥＧＲによって発生する黒煙を防止することができ
る。Therefore, excessive EGR of some of the cylinders caused by variation in the EGR rate between the cylinders can be prevented, and the combustion state of the engine can be maintained in a good condition. Can be prevented.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明に係る多気筒エンジンのＥＧＲ装置のシ
ステム構成図である。FIG. 1 is a system configuration diagram of an EGR device for a multi-cylinder engine according to the present invention.

【図２】従来技術の多気筒エンジンのＥＧＲ装置のシス
テム構成図である。FIG. 2 is a system configuration diagram of an EGR device of a conventional multi-cylinder engine.

【図３】エンジンの運転状態（６０％回転、８０％負
荷）と各気筒のＥＧＲ率の関係を示す図である。FIG. 3 is a diagram showing a relationship between an operating state of an engine (60% rotation, 80% load) and an EGR rate of each cylinder.

【図４】エンジンの運転状態（８０％回転、８０％負
荷）と各気筒のＥＧＲ率の関係を示す図である。FIG. 4 is a diagram showing a relationship between an engine operating state (80% rotation, 80% load) and an EGR rate of each cylinder.

【図５】ＥＧＲ率と吸気温度の関係を示す図である。FIG. 5 is a diagram showing a relationship between an EGR rate and intake air temperature.

【図６】ＥＧＲ率の気筒間バラツキと黒煙発生レベルの
関係を示す図である。FIG. 6 is a graph showing the relationship between the EGR rate variation between cylinders and the black smoke generation level.

【符号の説明】[Explanation of symbols]

１ エンジン本体 ２ 排気マニホール
ド ３ 吸気マニホールド ４ ＥＧＲ弁 ５ ＥＧＲクーラー ６ ＥＧＲ通路 ７ 冷却水通路 ８ 吸気通路 ９ コントローラ 10 吸気枝通路 11 吸気温度センサ Ａ 新気 Ａ＋Ｇｅ 吸気 Ｇ 排気ガス Ｇｅ ＥＧＲガス ＬＯＡＤ 負荷 ＮＥ 回転速度 Ｔｉ、Ｔ1 、Ｔ2 、Ｔ3 、Ｔ4 各気筒の吸気温度DESCRIPTION OF SYMBOLS 1 Engine main body 2 Exhaust manifold 3 Intake manifold 4 EGR valve 5 EGR cooler 6 EGR passage 7 Cooling water passage 8 Intake passage 9 Controller 10 Intake branch passage 11 Intake temperature sensor A Fresh air A + Ge Intake G Exhaust gas Ge EGR gas LOAD Load NE rotation Velocity Ti, T1, T2, T3, T4 Intake temperature of each cylinder

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 エンジンの排気通路と吸気通路とを連結
するＥＧＲ通路を設けて、該ＥＧＲ通路にＥＧＲガス量
を調整するＥＧＲ弁を配設した多気筒エンジンにおい
て、前記吸気通路から分岐されエンジンの各気筒に接続
される各吸気枝通路に吸気温度センサを設けると共に、
該吸気温度センサの検出値を入力して、前記ＥＧＲ弁の
弁開度を制御するコントローラを備えたことを特徴とす
る多気筒エンジンのＥＧＲ装置。1. A multi-cylinder engine provided with an EGR passage that connects an exhaust passage and an intake passage of an engine, and an EGR valve that adjusts an EGR gas amount in the EGR passage. In addition to providing an intake air temperature sensor in each intake branch passage connected to each of the cylinders,
An EGR device for a multi-cylinder engine, comprising: a controller that inputs a detection value of the intake air temperature sensor and controls a valve opening of the EGR valve. 【請求項２】 前記コントローラは、前記吸気温度セン
サの検出値から各気筒毎のＥＧＲ率と、このＥＧＲ率の
バラツキ度合いを演算する演算手段と、この演算結果の
ＥＧＲ率のバラツキ度合いと所定のバラツキ判定値とを
比較する比較判定手段と、この比較判定手段によって前
記演算結果のＥＧＲ率のバラツキ度合いが前記バラツキ
判定値より大きい時に、前記演算結果のＥＧＲ率のバラ
ツキ度合いが前記バラツキ判定値より小さくなるまで、
前記ＥＧＲ弁の弁開度を減少するように制御するＥＧＲ
弁制御手段とを備えていることを特徴とする請求項１記
載の多気筒エンジンのＥＧＲ装置。2. The controller according to claim 1, wherein said controller calculates an EGR rate for each cylinder based on a value detected by said intake air temperature sensor, and calculates a degree of variation of said EGR rate. Comparing and comparing means for comparing the variation determination value with the variation determination value, and when the variation degree of the EGR rate of the calculation result is larger than the variation determination value, the variation degree of the EGR rate of the calculation result is larger than the variation determination value. Until it gets smaller
EGR for controlling the degree of opening of the EGR valve to decrease
2. The EGR device for a multi-cylinder engine according to claim 1, further comprising valve control means. 【請求項３】 前記コントローラは、前記吸気温度セン
サの検出値のバラツキ度合いを演算する演算手段と、こ
の演算結果のバラツキ度合いと所定のバラツキ判定値と
を比較する比較判定手段と、この比較判定手段によって
前記検出値のバラツキ度合いが前記バラツキ判定値より
大きい時に、前記検出値のバラツキ度合いが前記バラツ
キ判定値より小さくなるまで、前記ＥＧＲ弁の弁開度を
減少するように制御するＥＧＲ弁制御手段と備えている
ことを特徴とする請求項１記載の多気筒エンジンのＥＧ
Ｒ装置。3. The controller according to claim 1, wherein said controller calculates a degree of variation of the detection value of said intake air temperature sensor, a comparison determining means for comparing the degree of variation of the calculation result with a predetermined variation determination value, Means for controlling the EGR valve to decrease the valve opening degree until the degree of variation of the detection value becomes smaller than the variation determination value when the degree of variation of the detection value is greater than the variation determination value. 2. The EG for a multi-cylinder engine according to claim 1, further comprising:
R device. 【請求項４】 前記コントローラは、前記吸気温度セン
サの検出値から各気筒のＥＧＲ率を演算する演算手段
と、この演算結果の各気筒のＥＧＲ率と所定のＥＧＲ率
上限値とを比較する比較判定手段と、この比較判定手段
によって前記演算結果の各気筒のＥＧＲ率が前記ＥＧＲ
率上限値より大きい時に、前記演算結果の各気筒のＥＧ
Ｒ率が前記ＥＧＲ率上限値より小さくなるまで、前記Ｅ
ＧＲ弁の弁開度を減少するように制御するＥＧＲ弁制御
手段とを備えていることを特徴とする請求項１記載の多
気筒エンジンのＥＧＲ装置。4. A controller for calculating an EGR rate of each cylinder from a detected value of the intake air temperature sensor, and a controller for comparing the EGR rate of each cylinder with a predetermined upper limit of the EGR rate based on the calculation result. The EGR rate of each cylinder as a result of the calculation is determined by the determination means and the comparison determination means.
When the ratio is greater than the rate upper limit value, the EG of each cylinder of the calculation result is obtained.
Until the R rate becomes smaller than the EGR rate upper limit, the E
2. The EGR device for a multi-cylinder engine according to claim 1, further comprising EGR valve control means for controlling the degree of opening of the GR valve to decrease.
JP10061825A 1998-03-13 1998-03-13 Egr device of multiple cylinder engine Pending JPH11257162A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10061825A JPH11257162A (en) 1998-03-13 1998-03-13 Egr device of multiple cylinder engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10061825A JPH11257162A (en) 1998-03-13 1998-03-13 Egr device of multiple cylinder engine

Publications (1)

Publication Number Publication Date
JPH11257162A true JPH11257162A (en) 1999-09-21

Family

ID=13182266

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10061825A Pending JPH11257162A (en) 1998-03-13 1998-03-13 Egr device of multiple cylinder engine

Country Status (1)

Country Link
JP (1) JPH11257162A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20030032659A (en) * 2001-10-19 2003-04-26 현대자동차주식회사 an exhaust gas recirculation system of diesel engine
JP2009510326A (en) * 2005-09-29 2009-03-12 インターナショナル エンジン インテレクチュアル プロパティー カンパニー リミテッド ライアビリティ カンパニー Model-based controller for optimization of self-ignition in diesel engines

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20030032659A (en) * 2001-10-19 2003-04-26 현대자동차주식회사 an exhaust gas recirculation system of diesel engine
JP2009510326A (en) * 2005-09-29 2009-03-12 インターナショナル エンジン インテレクチュアル プロパティー カンパニー リミテッド ライアビリティ カンパニー Model-based controller for optimization of self-ignition in diesel engines

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