JPS6179828A - Exhaust gas recirculating device in diesel engine - Google Patents

Exhaust gas recirculating device in diesel engine

Info

Publication number
JPS6179828A
JPS6179828A JP59202600A JP20260084A JPS6179828A JP S6179828 A JPS6179828 A JP S6179828A JP 59202600 A JP59202600 A JP 59202600A JP 20260084 A JP20260084 A JP 20260084A JP S6179828 A JPS6179828 A JP S6179828A
Authority
JP
Japan
Prior art keywords
exhaust gas
intake
temperature
throttle valve
gas recirculation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP59202600A
Other languages
Japanese (ja)
Other versions
JPH063150B2 (en
Inventor
Yoshitaka Nomoto
義隆 野元
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.)
Mazda Motor Corp
Original Assignee
Mazda Motor Corp
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 Mazda Motor Corp filed Critical Mazda Motor Corp
Priority to JP59202600A priority Critical patent/JPH063150B2/en
Publication of JPS6179828A publication Critical patent/JPS6179828A/en
Publication of JPH063150B2 publication Critical patent/JPH063150B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
    • F02D9/02—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning induction conduits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/0047—Controlling exhaust gas recirculation [EGR]
    • F02D41/0065—Specific aspects of external EGR control
    • 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
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/38—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with two or more EGR valves disposed in parallel
    • 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
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
    • 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)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)

Abstract

PURPOSE:To prevent compressed pressure from lowering, in an engine in which an intake-air throttle valve is disposed in an intake-air passage upstream of the opening sections of EGR passages so that it is throttled upon EGR by a predetermined amount, by decreasing the throttling degree of the throttle valve when the temperature of the engine, etc. is low. CONSTITUTION:An exhaust recirculating device recirculates a part of exhaust gas from an exhaust passage 3 into an intake-air passage 2 through first and second EGR passages 4, 5. Further, an intake-air throttle vale 14 is disposed in the intake-air passage 2 upstream of the openings of the EGR passages 4, 5. These valves 6, 7, 14 are arranged to be controlled by a control unit 18 such that the EGR valve 6 is opened upon high load operation while the EGR valve 4 is opened upon intermediate load operation, and further the throttle valve 14 is closed while the EGR valve 7 is left to be opened upon low load operation. In this arrangement, control is made such that the lower the temperature of cooling water which is detected by a water temperature sensor, the less the throttling amount of the throttle valve is made.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明はディーゼルエンジンの排気還流装置、特に吸気
絞弁を備えた排気還流装置における暖別時の制御に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust gas recirculation system for a diesel engine, particularly to control during warming up of an exhaust gas recirculation system equipped with an intake throttle valve.

（従　来　技　術） 自動車用等のエンジンにおいては、排気ガス中のＮＯｘ
を低減させるために、排気ガスの一部を吸気系に還流さ
せることが一般に行われているが、ディーゼルエンジン
の場合には、吸気負圧を利用して排気ガスを吸気系に吸
い込ませることができないという問題がある。そこで、
例えば特開昭５７−４１４５３号公報に開示されている
ように、吸気通路における排気還流通路の開口部上流側
に吸気絞弁を備え、排気還流時に該絞弁を閉作動させて
吸気負圧を発生させることにより排気ガスを効果的に還
流させることが行われている。(Conventional technology) In automobile engines, NOx in exhaust gas
In order to reduce this, it is common practice to recirculate some of the exhaust gas back into the intake system, but in the case of diesel engines, it is also possible to draw exhaust gas into the intake system using intake negative pressure. The problem is that it can't be done. Therefore,
For example, as disclosed in Japanese Patent Application Laid-open No. 57-41453, an intake throttle valve is provided upstream of the opening of the exhaust gas recirculation passage in the intake passage, and the throttle valve is closed during exhaust gas recirculation to reduce the intake negative pressure. The exhaust gas is effectively refluxed by generating the exhaust gas.

一方、このような排気還流システムを備えたディーゼル
エンジンにおいては、上記公報にも記載されているよう
に、冷間始動時にエンジンの暖機を促進してＩ−（Ｃや
Ｇｏ等の排出を低減させるために排気還流を行うことが
ある。つまり、高温の排気ガスを吸気系に導入すること
により、吸気を加熱して暖機を促進させるのであるが、
その場合、エンジン温度が低いほど排気還流量を多くし
て吸気加熱効果を高めるのが通例である。従って、上記
のように吸気絞弁を閉作動させることにより排気還流を
行うものにおいては、低温時はど吸気絞弁の絞量を多く
することになる。On the other hand, in a diesel engine equipped with such an exhaust recirculation system, as described in the above publication, the engine warm-up is promoted during cold start to reduce emissions of I-(C, Go, etc.). Exhaust gas recirculation is sometimes performed in order to warm up the engine.In other words, by introducing high-temperature exhaust gas into the intake system, the intake air is heated and warmed up.
In this case, it is customary to increase the amount of exhaust gas recirculation to increase the intake air heating effect as the engine temperature decreases. Therefore, in the case where the exhaust gas is recirculated by closing the intake throttle valve as described above, the amount of throttle of the intake throttle valve is increased when the temperature is low.

然るに、暖機時において、エンジン温度が低いほど吸気
絞弁の絞量を多くすると、吸気の充填量が減少すると共
に、これに伴って圧縮圧力が低下し、更に圧縮による吸
気の温度上［ｔが少なくなる。つまり、吸気絞弁の絞量
を多くすると、排気還流による吸気の加熱効果は高まる
が、その反面で圧縮による吸気の温度上昇ｍが減少し、
その結果、暖機が効果的に行われないことになる。特に
、エンジン温度が低いＦＩｊｉ機開始直後においては、
未だ着火していない気筒があって排気ガスの温度が十分
高くなっていないから、この時期に吸気絞弁の絞…を多
くすると、排気還流による吸気の加熱効果よりも吸気充
填ｍの減少ないし圧縮圧力の低下による温度上昇量の減
少が上回り、その結果、８１機性を却って悪くするので
ある。However, during warm-up, if the throttle amount of the intake throttle valve is increased as the engine temperature is lower, the filling amount of the intake air decreases, the compression pressure decreases accordingly, and the temperature of the intake air due to compression [t becomes less. In other words, increasing the throttle amount of the intake throttle valve increases the heating effect of the intake air due to exhaust gas recirculation, but on the other hand, the temperature rise m of the intake air due to compression decreases.
As a result, warm-up is not performed effectively. Especially immediately after starting a FIji aircraft when the engine temperature is low,
There are cylinders that have not yet ignited, and the temperature of the exhaust gas is not high enough, so if the intake throttle valve is throttled more at this time, the intake air charge m will be reduced or compressed more than the heating effect of the intake air due to exhaust gas recirculation. The decrease in temperature increase due to the decrease in pressure exceeds the decrease, and as a result, the 81 mechanical properties are rather deteriorated.

（発　　明　　の　　目　　的） 本発明は、吸気通路に設けた吸気絞弁を閉作動させるこ
とにより排気還流を行うようにしたディーゼルエンジン
の排気還流装置において、暖機促進のための排気還流時
に、吸気絞りによる圧縮圧力の低下ないし吸気の温度上
昇量の減少を防止し、もって暖機を効果的に行ってＨＣ
やＣＯ等の排出を低減させることを目的とする。(Object of the Invention) The present invention provides an exhaust gas recirculation device for a diesel engine in which exhaust gas recirculation is performed by closing an intake throttle valve provided in an intake passage. This prevents a decrease in compression pressure or a decrease in intake air temperature due to intake throttling, thereby effectively warming up the HC.
The purpose is to reduce emissions of carbon dioxide and CO.

（発　　明　　の　　構　　成） 即ち、本発明は、吸気通路における排気還流通路の開口
部上流側に吸気絞弁を備え、排気還流時に該吸気絞弁を
所定開度に絞るように構成したディ戸ゼルエンジンの排
気還流装置において、エンジン温度もしくは吸気温度に
関連する温度を検出する温度検出手段を設けると共に、
該検出手段で検出した温度が低い時に上記吸気絞弁の絞
量を減少させる排気還流制御手段を備えたことを特徴と
する。(Structure of the Invention) That is, the present invention provides a di-door which is provided with an intake throttle valve on the upstream side of the opening of the exhaust gas recirculation passage in the intake passage, and configured to throttle the intake throttle valve to a predetermined opening degree during exhaust gas recirculation. In the exhaust gas recirculation device of a diesel engine, a temperature detection means for detecting a temperature related to the engine temperature or the intake air temperature is provided, and
The present invention is characterized in that it includes exhaust gas recirculation control means that reduces the amount of throttle of the intake throttle valve when the temperature detected by the detection means is low.

このような構成によれば、暖機時においてエンジン温度
が比較的高温の場合は、排気還流によって効果的に吸気
が加熱されると共に、暖機開始直後等のエンジン低温時
、即ち排気ガスの温度が低いため排気還流による吸気加
熱効果が十分に得られない場合は、吸気絞弁の絞ωが少
なくされることにより、所要の吸気充ｌｉＮが確保され
て圧縮圧力の増大による吸気温度の上昇効果が得られる
ことになる。従って、エンジン温度が低い時から比較的
高温に上昇するまでの広い範囲で良好な暖確性が得られ
ることになる。尚、吸気絞弁の絞母をエンジン温度ない
し吸気温度の低温時に少なくする方法としては、該温度
が低いほど無段階的に絞ｍを減少させる方法と、所定温
度の前接で絞量を段階的に変化させる方法とがある。According to such a configuration, when the engine temperature is relatively high during warm-up, the intake air is effectively heated by exhaust gas recirculation, and when the engine is low, such as immediately after the start of warm-up, that is, the temperature of exhaust gas is If the intake air heating effect due to exhaust gas recirculation cannot be sufficiently obtained due to low will be obtained. Therefore, good heating accuracy can be obtained over a wide range from when the engine temperature is low to when the engine temperature rises to a relatively high temperature. Note that there are two methods for reducing the throttle mass of the intake throttle valve when the engine temperature or intake air temperature is low: one is to reduce the throttle m in a stepless manner as the temperature is lower, and the other is to reduce the throttling amount in stages before reaching a predetermined temperature. There is a way to change it.

（実　　施　　例） 以下、本発明の実施例について説明する。(Example) Examples of the present invention will be described below.

第１図に示すように、エンジン１には各気筒の燃焼室に
吸気を供給する吸気通路２と、燃焼によって生じた排気
ガスを外部に一放出する排気通路３とが設けられている
と共に、該排気通路３と吸気通路２との間には排気ガス
の一部を吸気通路２内に還流させる第１．第２排気還流
通路４．５が設けられ、且つこれらの通路４．５には排
気還流量を制御する第１．第２還流制御弁（以下、ＥＧ
Ｒ弁という）６．７が設置されている。そして、これら
のＥＧＲ弁６，７を夫々作動させる負圧ダイヤフラム式
のアクチュエータ８．９が備えられていると共に、図示
しない負圧ポンプと両アクチュエータ８．９との間の負
圧導入通路１０．１１には夫々デユーティ制御式の第１
．第２負圧制御弁１２．１３が設置され、該制御弁１２
．１３の開閉状態ないし開閉時間比率（デユーティ比）
に応じて各アクチュエータ８，９内の負圧がコントロー
ルされることにより、第１．第２ＥＧＲ弁６゜７の開度
が制御されるようになっている。ここで、第１　ＥＧＲ
弁６の全開時の通路面積は第２ＥＧＲ弁７の全開時の通
路面積より小とされている。As shown in FIG. 1, an engine 1 is provided with an intake passage 2 that supplies intake air to the combustion chamber of each cylinder, and an exhaust passage 3 that discharges exhaust gas generated by combustion to the outside. Between the exhaust passage 3 and the intake passage 2, there is a first pipe which recirculates part of the exhaust gas into the intake passage 2. A second exhaust gas recirculation passage 4.5 is provided, and a first exhaust gas recirculation passage 4.5 for controlling the amount of exhaust gas recirculation is provided in these passages 4.5. Second reflux control valve (hereinafter referred to as EG
6.7 (referred to as R valve) is installed. A negative pressure diaphragm type actuator 8.9 for operating these EGR valves 6 and 7, respectively, is provided, and a negative pressure introduction passage 10.9 is provided between a negative pressure pump (not shown) and both actuators 8.9. 11 each have a duty control type first
．． A second negative pressure control valve 12.13 is installed, the control valve 12.
．． 13 open/close states or open/close time ratio (duty ratio)
By controlling the negative pressure within each actuator 8, 9 according to the first. The opening degree of the second EGR valve 6°7 is controlled. Here, the first EGR
The passage area when the valve 6 is fully open is smaller than the passage area when the second EGR valve 7 is fully open.

一方、上記吸気通路２における第１．第２排気還流通路
４．５の開口部の上流側には吸気絞弁１４が設けられて
いると共に、該吸気絞弁１４を開閉駆動する負圧ダイレ
フ５６式のアクチュエータ１５が備えられている。そし
て、このアクチュエータ１５に負圧を導入する負圧導入
通路１６にもデユーティ制御式の第３負圧制御弁１７が
設置されている。On the other hand, the first. An intake throttle valve 14 is provided on the upstream side of the opening of the second exhaust gas recirculation passage 4.5, and a negative pressure die reflex 56 type actuator 15 for driving the intake throttle valve 14 to open and close is provided. A third negative pressure control valve 17 of duty control type is also installed in the negative pressure introduction passage 16 through which negative pressure is introduced into the actuator 15 .

然して、上記アクチュエータ８．９を介して第１、第２
ＥＧＲ弁６．７を制御する第１．第２負圧制御弁１２．
１３及びアクチュエータ１５を介して吸気絞弁１４を制
御する第３負圧制御弁１７には、コントロールユニット
１８から夫々制御信号（デユーティ信号）Ａ、Ｂ、Ｃが
送出されているようになっていると共に、該コントロー
ルユニット１８には燃料噴射ポンプ１９に備えられた回
転センサ２０からの回転信号りと、該ポンプ１９におけ
るコントロールレバーの位置からこれに連動するアクセ
ルペダルのポジションを検出するアクセルポジションセ
ンサ２１からの負荷信号Ｅと、エンジン１のウォーター
ジャケットに備えられた水温センサ２２から−の水温信
号Ｆとが入力され、これらの入力信号り、Ｅ、Ｆに基づ
いて、エンジン１の運転状態に応じて上記制御信号Ａ、
Ｂ、Ｃを出力するようになっている。ここで、上記燃料
噴射ポンプ１９はエンジン１の各気筒に備えられた燃料
噴射ノズル（図示せず）に燃料を圧送するものであるが
、その噴射ｍは該ポンプ１９の回転速度（エンジン回転
速度に対応する）とアクセルポジションに応じて設定さ
れるようになっている。Therefore, the first and second
The first one controls the EGR valve 6.7. Second negative pressure control valve 12.
Control signals (duty signals) A, B, and C are sent from the control unit 18 to the third negative pressure control valve 17 that controls the intake throttle valve 14 via the intake throttle valve 13 and the actuator 15, respectively. In addition, the control unit 18 includes a rotation signal from a rotation sensor 20 provided in the fuel injection pump 19, and an accelerator position sensor 21 that detects the position of the accelerator pedal linked to the control lever position of the pump 19. A load signal E from the engine 1 and a water temperature signal F from the water temperature sensor 22 provided in the water jacket of the engine 1 are input, and based on these input signals E, F, the engine 1 is and the above control signal A,
B and C are output. Here, the fuel injection pump 19 is for pumping fuel to fuel injection nozzles (not shown) provided in each cylinder of the engine 1, and the injection m is determined by the rotational speed of the pump 19 (engine rotational speed). ) and the accelerator position.

次に、この実施例の作動を第２図のフローチャート図に
従って説明する。Next, the operation of this embodiment will be explained according to the flowchart shown in FIG.

先ず、コントロールユニット１８は、第２図のステップ
Ｓ１．Ｓ２に従って第１図に示す水温センサ２２からの
水温信号Ｆを入力し、該信号Ｆが示すエンジン１のウォ
ータージャケットにおける冷却水温度Ｔが８０℃以上か
否かを判定する。そして、該温度Ｔが８０℃以上の場合
、換言すればエンジン１の通常の運転時には、次にステ
ップＳ３．８４に従って回転センサ２０からの回転信号
りを入力し、該信号りに基づいてエンジン回転速度Ｎを
検出すると共に、該回転速度Ｎが９００〜３０００ＲＰ
Ｍの範囲内にあるか否かを判定し、この範囲内に含まれ
ている場合は、更にステップＳ５でアクセルポジション
センサ２１からの負荷信号Ｅを入力する。この負荷信号
Ｅが示すアクセルポジションと上記エンジン回転速度Ｎ
とは第１図に示す燃料噴射ポンプ１つの燃料噴射量を決
定するものであるが、燃料噴射口は燃焼室内の図示平均
有効圧力に対応するので、上記アクセルポジションとエ
ンジン回転速度Ｎとから図示平均有効圧力ｐｅが求めら
れることになる。そして、コントロールユニット１８は
、ステップＳ６でこの図示平均有効圧力ｐｃがＯ〜６　
Ｋ’３　／　ｃＡの範囲内にあるか否かを判定し、この
範囲内にある時にステップ８７〜Ｓ　１２による通常運
転時の排気還流制御を行う。つまり、冷却水温度Ｔが８
０℃以上であり、エンジン回転速度Ｎが９００〜３００
０ＰＰＭの範囲内にあり、且つ図示平均有効圧力ｐｅが
Ｏ〜６　ＫＣＩ／　ｃｒＡの範囲内にある時に通常の排
気還流制御が行われるのである。First, the control unit 18 performs step S1 in FIG. According to S2, the water temperature signal F from the water temperature sensor 22 shown in FIG. 1 is input, and it is determined whether the cooling water temperature T in the water jacket of the engine 1 indicated by the signal F is 80° C. or higher. When the temperature T is 80° C. or higher, in other words, during normal operation of the engine 1, the rotation signal from the rotation sensor 20 is inputted in accordance with step S3.84, and the engine speed is increased based on the signal. While detecting the speed N, the rotation speed N is 900 to 3000RP
It is determined whether or not it is within the range of M, and if it is within this range, the load signal E from the accelerator position sensor 21 is further input in step S5. The accelerator position indicated by this load signal E and the engine rotation speed N
determines the fuel injection amount of one fuel injection pump shown in FIG. 1. Since the fuel injection port corresponds to the indicated average effective pressure in the combustion chamber, The average effective pressure pe will be determined. Then, in step S6, the control unit 18 determines that the indicated mean effective pressure pc is O~6.
It is determined whether or not it is within the range of K'3/cA, and when it is within this range, the exhaust gas recirculation control during normal operation is performed in steps 87 to S12. In other words, the cooling water temperature T is 8
The temperature is 0°C or higher, and the engine rotation speed N is 900 to 300
Normal exhaust gas recirculation control is performed when the indicated mean effective pressure pe is within the range of 0 PPM and within the range of 0 to 6 KCI/crA.

この制御は、上記図示平均有効圧力Ｐｅの値に応じて次
のように行われる。即ち、コントロールユニット１８は
、該圧力ｐｅが５〜６　ｎ　／　ｃｔＡの範囲内にある
比較的高負荷時にはステップＳ７からステップＳ８を実
行して、第１図に示す通路面積の小さい第１　ＥＧＲ弁
６を開くように第１負圧制御弁１２に制御信号Ａを出力
し、また該圧力ｐｅが４．５〜５１’ｌ　／ｃｒＡの範
囲内にある中負荷時には上記ステップＳｒからステップ
Ｓ９．Ｓ＋ｏを実行して、通路面積の大きい第２２ＧＲ
弁７を開くように第２負圧制御弁１３に制御信号Ｂを出
力する。This control is performed as follows depending on the value of the indicated mean effective pressure Pe. That is, when the pressure pe is in the range of 5 to 6 n/ctA and the load is relatively high, the control unit 18 executes steps S7 to S8 to control the first EGR valve with a small passage area shown in FIG. A control signal A is output to the first negative pressure control valve 12 so as to open the control valve 6, and when the pressure pe is in the range of 4.5 to 51'l/crA and the load is medium, the step Sr to step S9. Execute S+o and move to the 22nd GR, which has a large passage area.
A control signal B is output to the second negative pressure control valve 13 to open the valve 7.

更に、該圧力ｐｅがＯ〜４　、５　豹／　ｃｒＡの範囲
内にある低負荷時には上記ステップＳ９からステップＳ
ｏ、Ｓ＋ｚを実行し、第２ＥＧＲ弁７を開くように第２
負圧制御弁１３に制御信号Ｂを出力すると共に、吸気絞
弁１４を閉じるように第３負圧制郊弁１７に制御信号Ｃ
を出力する。そのため、上記の排気還流制御を行う領域
において、高負荷時には第１排気還流通路４により通路
面積の小さい第１　ＥＧＲ弁８を通って比較的少量の排
気ガスが排気通路３から吸気通路２に還流され、また中
負荷時には第２排気還流通路５により通路面積の大きい
第２ＥＧＲ弁７を通って比較的多量の排気ガスが還流さ
れることになり、更に低負荷時には通路面積の大きい第
２ＥＧＲ弁７が開くと同時に、吸気通路２における吸気
絞弁１４が閉じて排気還流通路５の開口部周辺の負圧が
高まることにより、一層多吊の排気ガスが吸気通路２に
還流されることになる。その結果、第３図に示すように
負荷に応じて段階的に変化する排気還流特性が得られる
。Furthermore, at low load when the pressure pe is within the range of O to 4.5 crA, the steps S9 to S are performed.
o, S+z to open the second EGR valve 7.
A control signal B is output to the negative pressure control valve 13, and a control signal C is output to the third negative pressure control valve 17 to close the intake throttle valve 14.
Output. Therefore, in the region where the above-mentioned exhaust gas recirculation control is performed, when the load is high, a relatively small amount of exhaust gas is recirculated from the exhaust passage 3 to the intake passage 2 through the first EGR valve 8, which has a small passage area, by the first exhaust gas recirculation passage 4. In addition, at medium loads, a relatively large amount of exhaust gas is recirculated by the second exhaust gas recirculation passage 5 through the second EGR valve 7 with a large passage area, and at low loads, the second EGR valve 7 with a large passage area is recirculated. At the same time as opening, the intake throttle valve 14 in the intake passage 2 closes and the negative pressure around the opening of the exhaust gas recirculation passage 5 increases, so that even more exhaust gas is recirculated to the intake passage 2. As a result, as shown in FIG. 3, an exhaust gas recirculation characteristic that changes stepwise according to the load is obtained.

ここで、低角荷時はど排気還流ｍを多くするのは、ディ
ーゼルエンジンの場合、低負荷時には燃料噴射最に対す
る空気過剰率が著しく大きくなるので、多山の排気ガス
を還流しなければ所期の効果（ＮＯｘ低減効果）が得ら
れないからであり、また所定負荷以上（図示平均有効圧
力が６ＡＶ／ｄ以上）の高負荷域で排気還流を行わない
のは、このような領域で排気還流を行うと燃焼状態が著
しく悪化してスモークが発生するからである。The reason for increasing the exhaust gas recirculation m when the angle load is low is that in the case of a diesel engine, the excess air ratio relative to the fuel injection point becomes significantly large at low loads, so if a large number of exhaust gases are not recirculated, it is necessary to This is because the effect (NOx reduction effect) cannot be obtained during the period, and the reason why exhaust gas recirculation is not performed in a high load range above a predetermined load (indicated average effective pressure is 6 AV/d or more) is because exhaust gas recirculation is not performed in such a region. This is because if reflux is performed, the combustion condition will be significantly deteriorated and smoke will be generated.

然して、冷却水温度Ｔが８０℃以下のエンジン１の暖機
時には、コントロールユニット１８は第２図のステップ
Ｓ２からステップ８１３を実行し、エンジン回転数Ｎが
１０００〜３０００ＰＰＭの範囲内にあるか否かを判定
して、この範囲内にある時はステップ８１４〜Ｓ　＋ｅ
による暖機時の排気還流ＲＩＪ　Ｉｌｌを行う。つまり
、ステップＳ　１４で第１ＥＧＲ弁６を開くと共に、ス
テップＳ　＋ｓで上記水温センサ２２からの信号Ｆが示
す冷加水温度Ｔに応じて吸気絞弁１４のｗＵＩｉθを設
定する。この時、咳間度θは冷部水＠度Ｔに対して予め
設定されたマツプから読み取ることにより設定されるが
、このマツプは第４図に示すような特性で設定されてい
る。つまり、冷却水温度Ｔが低いほど吸気絞弁１４の開
度θが大きくなるように（絞量が少なくなるように）設
定されているのである。そして、この特性に従って吸気
絞弁１４の開度θを冷却水温度Ｔに応じて設定した模、
コントロールユニット１８はステップＳ　＋ｓで吸気絞
弁１４の開度が上記設定開度θとなるように制御信号（
デユーティ信号）Ｃを第３負圧制御弁１７に出力する。However, when warming up the engine 1 when the coolant temperature T is 80° C. or lower, the control unit 18 executes steps S2 to 813 in FIG. If it is within this range, step 814~S +e
Perform exhaust gas recirculation RIJ Ill during warm-up. That is, in step S14, the first EGR valve 6 is opened, and in step S2+s, wUIiθ of the intake throttle valve 14 is set in accordance with the chilled water temperature T indicated by the signal F from the water temperature sensor 22. At this time, the cough interval degree θ is set by reading from a preset map for cold water @ temperature T, and this map is set with characteristics as shown in FIG. In other words, the lower the cooling water temperature T, the larger the opening degree θ of the intake throttle valve 14 (the smaller the throttle amount). In accordance with this characteristic, the opening degree θ of the intake throttle valve 14 is set according to the cooling water temperature T.
In step S+s, the control unit 18 sends a control signal (
Duty signal) C is output to the third negative pressure control valve 17.

これにより、暖機時における吸気絞弁１４の絞量が冷部
水＠［Ｔが低いほど少なくなり、そのため、暖機開始直
後等のエンジン低温時に所要量の吸気充填ｍが確保され
ると共に、これに伴って高い圧縮圧力と、この圧縮によ
る吸気の十分な温度上昇が得られることになり、その結
果、暖機が促進されることになる。その場合に、吸気絞
弁１４の絞ｍが少ないことにより排気還流９が減少する
が、エンジン低温時には排気ガスの温度が低いので、排
気還流量を多くすることよりも上記のように吸気充ｌＸ
ｆｆ１ないし圧縮圧力を確保することによる方が＠機促
進に対して有効なのである。そして、エンジン温度が上
昇すれば、これに伴って吸気絞弁１４の絞量が増大され
ることにより排気還流量が多くなり、高温となった排気
ガスにより吸気が効果的に加熱されて、更に暖機が促進
されることになる。As a result, the throttle amount of the intake throttle valve 14 during warm-up becomes smaller as the cold part water @ Accordingly, a high compression pressure and a sufficient temperature rise of the intake air due to this compression are obtained, and as a result, warm-up is promoted. In this case, the exhaust gas recirculation 9 is reduced due to the small throttle m of the intake throttle valve 14, but since the temperature of the exhaust gas is low when the engine is low, the intake air refill l
It is more effective to promote @machine by securing ff1 or compression pressure. When the engine temperature rises, the amount of throttle of the intake throttle valve 14 increases accordingly, increasing the amount of exhaust gas recirculation, and the intake air is effectively heated by the high-temperature exhaust gas. Warming up will be accelerated.

ここで、この実施例においては、吸気絞弁１４の絞量（
開度）をデユーティ制御して、第４図に示すように冷却
水温度が低いほど開度を無段階的に増大させるように構
成したが、冷却水温度のある値を境として低温側では吸
気絞弁を開き、高温側では閉じるように制（社）しても
よい。Here, in this embodiment, the throttle amount of the intake throttle valve 14 (
As shown in Figure 4, the lower the cooling water temperature, the lower the cooling water temperature is, the lower the opening degree is. The throttle valve may be opened and closed on the high temperature side.

（発　　明　　の　　効　　果） 以上のように本発明によ枕ば、排気還流時に吸気通路に
設けた吸気絞弁を閉作動させるように構成したディーゼ
ルエンジンの排気還流装置において、暖機促進のための
排気還流時に、暖機開始直後のエンジン低温時には所要
の吸気充填量ないし圧縮圧力が確保されて、この圧縮に
よる吸気温度の上昇効果が得られ、またエンジン温度が
上昇すればａ潟の排気ガスによる吸気加熱効果が得られ
ることになる。これにより、暖機開始直後から良好な暖
機性が得られ、暖機が促進されると共に、暖機中におけ
るＨＣやｃｏ等の排出が低減される。(Effects of the Invention) As described above, according to the present invention, an exhaust gas recirculation device for a diesel engine configured to close an intake throttle valve provided in an intake passage during exhaust gas recirculation can be used to promote warm-up. During exhaust gas recirculation, when the engine temperature is low immediately after the start of warm-up, the required intake air filling amount or compression pressure is ensured, and this compression produces the effect of increasing the intake air temperature, and when the engine temperature rises, the exhaust gas in the This results in an intake air heating effect. As a result, good warm-up performance is obtained immediately after the start of warm-up, warm-up is promoted, and emissions of HC, co, etc. are reduced during warm-up.

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

図面は本発明の実施例を示すもので、第１図は制御シス
テム図、第２図は作動を示すフローチャート図、第３図
は通常の排気還流制御の特性図、第４図は暖機時の排気
還流制御における吸気絞弁開度の制御特性図である。 １・・・エンジン、２・・・吸気通路、３・・・排気通
路、４．５・・・排気還流通路、１４・・・吸気絞弁、
１８・・・排気還流制御手段（コントロールユニット）
、２２・・・温度検出手段（水濡センサ）。The drawings show an embodiment of the present invention; Fig. 1 is a control system diagram, Fig. 2 is a flowchart showing the operation, Fig. 3 is a characteristic diagram of normal exhaust gas recirculation control, and Fig. 4 is a diagram showing the warm-up time. FIG. 3 is a control characteristic diagram of the intake throttle valve opening degree in exhaust gas recirculation control. DESCRIPTION OF SYMBOLS 1... Engine, 2... Intake passage, 3... Exhaust passage, 4.5... Exhaust recirculation passage, 14... Intake throttle valve,
18...Exhaust recirculation control means (control unit)
, 22...Temperature detection means (water wetness sensor).

Claims (1)

【特許請求の範囲】[Claims] （１）吸気通路における排気還流通路の開口部上流側に
吸気絞弁を備え、排気還流時に該吸気絞弁を所定開度に
絞るように構成したディーゼルエンジンの排気還流装置
であって、エンジン温度もしくは吸気温度に関連する温
度を検出する温度検出手段と、該検出手段で検出した温
度が低い時に上記吸気絞弁の絞量を減少させる排気還流
制御手段とを備えたことを特徴とするディーゼルエンジ
ンの排気還流装置。(1) An exhaust gas recirculation device for a diesel engine, which is equipped with an intake throttle valve upstream of the opening of the exhaust gas recirculation passage in the intake passage, and is configured to throttle the intake throttle valve to a predetermined opening degree during exhaust gas recirculation, the device comprising: Alternatively, a diesel engine comprising temperature detection means for detecting a temperature related to intake air temperature, and exhaust recirculation control means for reducing the throttle amount of the intake throttle valve when the temperature detected by the detection means is low. Exhaust recirculation device.
JP59202600A 1984-09-26 1984-09-26 Exhaust gas recirculation system for diesel engine Expired - Lifetime JPH063150B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59202600A JPH063150B2 (en) 1984-09-26 1984-09-26 Exhaust gas recirculation system for diesel engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59202600A JPH063150B2 (en) 1984-09-26 1984-09-26 Exhaust gas recirculation system for diesel engine

Publications (2)

Publication Number Publication Date
JPS6179828A true JPS6179828A (en) 1986-04-23
JPH063150B2 JPH063150B2 (en) 1994-01-12

Family

ID=16460137

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59202600A Expired - Lifetime JPH063150B2 (en) 1984-09-26 1984-09-26 Exhaust gas recirculation system for diesel engine

Country Status (1)

Country Link
JP (1) JPH063150B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0352364U (en) * 1989-09-28 1991-05-21
CN109555606A (en) * 2017-09-26 2019-04-02 株式会社斯巴鲁 EGR control device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57176639U (en) * 1981-04-30 1982-11-08
JPS5867955A (en) * 1981-10-20 1983-04-22 Nissan Motor Co Ltd Exhaust gas recirculating device of diesel engine

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57176639U (en) * 1981-04-30 1982-11-08
JPS5867955A (en) * 1981-10-20 1983-04-22 Nissan Motor Co Ltd Exhaust gas recirculating device of diesel engine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0352364U (en) * 1989-09-28 1991-05-21
CN109555606A (en) * 2017-09-26 2019-04-02 株式会社斯巴鲁 EGR control device
CN109555606B (en) * 2017-09-26 2022-10-11 株式会社斯巴鲁 EGR control device

Also Published As

Publication number Publication date
JPH063150B2 (en) 1994-01-12

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