JPS627943A - Exhaust reflux device of diesel engine - Google Patents

Exhaust reflux device of diesel engine

Info

Publication number
JPS627943A
JPS627943A JP60146244A JP14624485A JPS627943A JP S627943 A JPS627943 A JP S627943A JP 60146244 A JP60146244 A JP 60146244A JP 14624485 A JP14624485 A JP 14624485A JP S627943 A JPS627943 A JP S627943A
Authority
JP
Japan
Prior art keywords
egr
passage
warming
reflux
throttle valve
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
JP60146244A
Other languages
Japanese (ja)
Inventor
Junichi Kawashima
純一 川島
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.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co 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 Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Priority to JP60146244A priority Critical patent/JPS627943A/en
Publication of JPS627943A publication Critical patent/JPS627943A/en
Pending legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/52Systems for actuating EGR valves
    • F02M26/55Systems for actuating EGR valves using vacuum actuators
    • F02M26/56Systems for actuating EGR valves using vacuum actuators having pressure modulation valves
    • F02M26/57Systems for actuating EGR valves using vacuum actuators having pressure modulation valves using electronic means, e.g. electromagnetic valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/22Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
    • F02M26/23Layout, e.g. schematics
    • F02M26/25Layout, e.g. schematics with coolers having bypasses
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/22Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
    • F02M26/33Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage controlling the temperature of the recirculated gases
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/38Arrangement 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
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00Engines characterised by air compression and subsequent fuel addition
    • F02B3/06Engines characterised by air compression and subsequent fuel addition with compression ignition
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/22Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
    • F02M26/23Layout, e.g. schematics

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)
  • Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)

Abstract

PURPOSE:To prevent worsening of combustion during warming-up and decrease of an intake air amount after warming-up, by a method wherein reflux of high temperature EGR gas through a first EGR passage and reflux of low temperature EGR gas through a second EGR passage are effected according to an operating condition and a warming-up condition. CONSTITUTION:First and second EGR passage 21 and 22, through which a suction passage 2 and an exhaust passage 4 located down a line from a suction throttle valve 6 are intercommunicated, are formed. A first EGR control valve 24 is located in the first EGR passage 21, and a second EGR control valve 26 and a cooler 27, cooling reflux exhaust, are located in the second EGR passage 22. Meanwhile, a load sensor 18 and a rotation sensor 19, both detecting an operating condition, and a water temperature sensor 38, detecting a warming-up condition, are provided, and based on the detecting values thereof, a control circuit 39 controls the openings of the throttle valve 6 and the first and second EGR control valves 24 and 26. This performs reflux of high temperature EGR gas through the first EGR passage 21 as it is during warming-up, and effects reflux of EGR gas cooled through the second EGR passage 22 during normal operation after warming-up.

Description

【発明の詳細な説明】 (産業上の利用分野) この発明は、ディーゼルエンジンの排気還流装置に関す
る。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust gas recirculation device for a diesel engine.

(従来の技術) 一ンジンから排出されるNOVを低減する目的で排気の
一部を吸気中に還流し、燃焼を抑制する排気還流装置(
EGR装置)が知られているが、この排気還流装置では
、エンジンの運転性を損なわずに排気組成を改善するた
めには、還流する排気(、EGRガス)の流量を運転状
態に応じて適正に制御する必要がある。
(Prior art) Exhaust recirculation equipment (which recirculates part of the exhaust gas into intake air to suppress combustion in order to reduce NOV emitted from an engine)
In order to improve the exhaust composition without impairing engine drivability, the flow rate of the recirculated exhaust gas (EGR gas) must be adjusted appropriately according to the operating conditions. need to be controlled.

$11図は従来のディーゼルエンジンに装置ilされる
排気還流装置の一例で(実開昭58−75942号公報
参照)、1はエアクリーナ、2は吸気通路、3はエンジ
ン本体、4は排気通路、5は吸気通路2と排気通路4と
を連通するEGR通路を示し、吸気通路2にはEGR通
路5の開口部よりも上流側に絞り弁6が、またEGR通
路5の途中にはEGR制御制御弁ボンれぞれ介装されて
いる。
Figure 11 shows an example of an exhaust recirculation device installed in a conventional diesel engine (see Japanese Utility Model Application Publication No. 1987-75942), in which 1 is an air cleaner, 2 is an intake passage, 3 is an engine body, 4 is an exhaust passage, Reference numeral 5 indicates an EGR passage that communicates the intake passage 2 and the exhaust passage 4. The intake passage 2 has a throttle valve 6 upstream of the opening of the EGR passage 5, and an EGR control valve is provided in the middle of the EGR passage 5. Each valve bong is interposed.

絞り弁6はグイヤフラム装置8により駆動され、グイヤ
7ラム装置8の圧力室9に負圧源(バキュームポンプ、
バキュームタンク等)10からの負圧が作用すると所定
の半開位置に、圧力室9が大気に開放されると全開位置
になる。このときの負圧−大気圧の切り換えは、制御回
路11からの信号に応動する三方電磁弁12を介してな
される。
The throttle valve 6 is driven by a Guyafram device 8, and a negative pressure source (vacuum pump,
When negative pressure from a vacuum tank, etc.) 10 is applied, the chamber is placed in a predetermined half-open position, and when the pressure chamber 9 is opened to the atmosphere, it is placed in a fully open position. Switching between negative pressure and atmospheric pressure at this time is performed via a three-way solenoid valve 12 that responds to a signal from a control circuit 11.

EGR制御弁7は第2のグイヤ7ラム装置13により駆
動され、その圧力室14に負圧源10からの負圧がその
まま作用すると全開位置に、その負圧が減圧(オリフィ
ス15による)されると半開位置に、圧力室14が大気
に開放されると全閉位置になる。このと鰺の負圧−減圧
−大気圧の切り換えは、制御回路11からの信号に応動
する第2゜第3の三方電磁弁16.17による。ただし
、三方電磁弁1.2,16.:lマはそれぞれ通電ON
でボー)Nと肩を連通し、通電OFFでボー)Nとnを
連通する。
The EGR control valve 7 is driven by the second Guyar 7 ram device 13, and when the negative pressure from the negative pressure source 10 directly acts on the pressure chamber 14, the EGR control valve 7 is brought to the fully open position, and the negative pressure is reduced (by the orifice 15). When the pressure chamber 14 is opened to the atmosphere, it becomes a fully closed position. This switching between negative pressure, reduced pressure, and atmospheric pressure for the mackerel is performed by second and third three-way solenoid valves 16 and 17 that respond to signals from the control circuit 11. However, three-way solenoid valves 1, 2, 16. : Each motor is energized.
When the power is turned OFF, the baud)N and shoulder are connected, and when the power is turned off, the baud)N and n are connected.

そして、制御回路11は、図示しない燃料噴射ポンプの
コントロールレバーに追従する負荷センサ18を介して
エンジンの負荷状態を、回転センサ19を介してエンジ
ンの回転速度をそれぞれ検出し、運転状態に応じたE 
G Rlfx量、EGR率となるように前記三方電磁弁
12.:16,1.7を駆動する。
The control circuit 11 detects the load condition of the engine via a load sensor 18 that follows a control lever of a fuel injection pump (not shown) and the rotational speed of the engine via a rotation sensor 19, and detects the engine rotation speed according to the operating condition. E
G Rlfx amount and EGR rate, the three-way solenoid valve 12. :16,1.7 is driven.

例えば、比較的高率の排気還流を行う必要のある低速低
負荷域では、絞り弁(3が半開位置、、1すGR制御弁
7が全開位置となるように制御して、このとき絞り弁6
の下流側に生じる負圧で多量のEG Rffスを還流す
る。
For example, in a low-speed, low-load range where a relatively high rate of exhaust gas recirculation is required, the throttle valve (3) is controlled so that it is in the half-open position, and the GR control valve (1) is in the fully open position. 6
A large amount of EG Rff gas is refluxed by the negative pressure generated on the downstream side.

部分負荷域では、この状態から絞り弁6を全開位置にし
て吸入負圧の発生を解除し、ある程度負荷や回転速度が
大きくなるとtsG+<制御弁7を半開位置にしてEG
Rffx量奇減少させる。
In the partial load range, from this state, the throttle valve 6 is set to the fully open position to cancel the generation of suction negative pressure, and when the load or rotational speed increases to a certain extent, tsG+<control valve 7 is set to the half open position and EG
Decrease Rffx by an odd amount.

さらに負荷や回転速度が大きくなる高賃荷域や高回転域
では、エンジンめ高い出力を維持するようにE G R
制御弁7を全開にして排気還流を停止する。
Furthermore, in high load ranges and high rotation ranges where the load and rotational speed are large, the EGR is activated to maintain high output from the engine.
Control valve 7 is fully opened to stop exhaust gas recirculation.

このようにして、エンジンの運転状態に応じた適正な排
気還流を行うので、ある。尚、第12図に三方電磁弁1
2.16.L’l’の制御動作による絞り弁6、EGR
制御弁7の開度と、EGR率、の関係を示す。
In this way, appropriate exhaust gas recirculation is performed depending on the operating state of the engine. Furthermore, Figure 12 shows the three-way solenoid valve 1.
2.16. Throttle valve 6, EGR by control operation of L'l'
The relationship between the opening degree of the control valve 7 and the EGR rate is shown.

(発明が解決しようとする問題点) しかし、このような排気還1流装置にあっては、高温の
EGRガスが吸気中に′導入されるため、吸気の温度が
上昇し、したが9で実質的な吸気量が減少することから
、スモーク゛・やパーティキュレートが増加したり、燃
費等の悪化を招きやすい。また、EGRffスの密度が
低〜まため、大量のEGRが望まれる領域で十分なEQ
Rが大量が確保されず、このためNoにの効果的な抑制
を図りにくいということがあった。
(Problem to be Solved by the Invention) However, in such a single-flow exhaust gas recirculation system, the high temperature EGR gas is introduced into the intake air, so the temperature of the intake air increases. Since the actual amount of intake air decreases, smoke and particulates tend to increase and fuel efficiency deteriorates. In addition, since the density of the EGRff gas is low to high, sufficient EQ is required in areas where a large amount of EGR is desired.
A large amount of R was not secured, which made it difficult to effectively suppress No.

そこで、このような問題に対し、吸気中に還流されるE
GR4スを冷却することが考えられるが、これだとエン
ジンの暖機が不十分な場合に次のような不具合を生じる
Therefore, to solve this problem, the E recirculated into the intake air
One possibility is to cool the GR4, but this will cause the following problems if the engine is not warmed up enough.

例えば、直噴式のディーゼルエンジン等では、始動直後
のように暖機か不十分な場合、適当量の高温のEGRガ
スを還流すると、燃焼が安定すると共に、未燃HCの低
減が図れるが、このとき低温のEGR4スを還流してし
まうと、かえって燃焼を悪化させるのである。
For example, in direct-injection diesel engines, when warm-up is insufficient, such as immediately after startup, recirculating an appropriate amount of high-temperature EGR gas stabilizes combustion and reduces unburned HC. If the low-temperature EGR4 gas is refluxed, it will actually worsen combustion.

この発明は、EGRffスの冷却をエンジンの運転条件
に応じて行うことにより、これらの問題、α−4= を解決することを目的としている。
The present invention aims to solve these problems, α-4=, by cooling the EGRff according to the operating conditions of the engine.

(問題点を解決するための手段) この発明は、ftSi図に示すように吸気通路イの途中
に吸気絞り弁口を介装し、この絞り弁口下流の吸気通路
イと排気通路ハとを連通する第1.第2のEGR通路通
路水を形成し、第1のEGR通路通路水1のEGR制御
弁へを、第2のEGR通路ホに第2のE G R制御弁
トと還流排気を冷却する冷却器チを介装する一方、エン
ジンの運転状態を検出する手段すと、暖機状態を検出す
る手段ヌと、これらの検出値に基づいて前記絞り弁口と
、第1.第2のEGR制御弁へ、1・の開度を制御する
制御手段ルとを設ける。
(Means for Solving the Problems) This invention provides an intake throttle valve opening in the middle of the intake passage A, as shown in the ftSi diagram, and connects the intake passage A and the exhaust passage C downstream of the throttle valve opening. 1st communication. A cooler that forms passage water in the second EGR passage and cools the first EGR passage water 1 to the EGR control valve, the second EGR passage water 1 to the second EGR control valve, and the recirculated exhaust gas. On the other hand, means for detecting the operating state of the engine includes a means for detecting a warm-up state, a means for detecting the warm-up state, a means for detecting the warm-up state, and a means for detecting the throttle valve port based on these detected values. The second EGR control valve is provided with a control means for controlling the opening degree of 1.

(作用) したがって、暖機中は第1のEGR通路通路水してEG
Rffスを導くことで、高温のEGR,fスをそのまま
還流し、これにより暖機時の燃焼の悪化を防止する。
(Function) Therefore, during warm-up, the first EGR passage has water and the EGR
By guiding the Rff gas, the high temperature EGR and f gas are directly refluxed, thereby preventing deterioration of combustion during warm-up.

他方、暖機後の通常運転時は冷却器チを介装した第2の
EGr(通路ホを介してEGR1j′スを導くことで、
EGR)’f’スを冷却し、これにより吸気量の減少を
回避すると共に、適正量のEGR,ffスを確保するの
である。
On the other hand, during normal operation after warming up, the second EGr (EGR1j') with a cooler installed (by guiding the EGR1j' through the passage H,
This cools the EGR and ff spaces, thereby avoiding a decrease in the amount of intake air and ensuring an appropriate amount of EGR and ff spaces.

(実施例) 以下、本発明の実施例を図面に基づいて説明する。(Example) Embodiments of the present invention will be described below based on the drawings.

第2図において、1はエアクリーナ、2は吸気通路、3
はエンジン本体、4は排気通路(排気マニホールド)、
20はターボチャージャで、ターボチャージャ20上流
の吸気通路2にダイヤ7ラム装置8により駆動される吸
気の絞り弁6が介装される。
In Fig. 2, 1 is an air cleaner, 2 is an intake passage, and 3 is an air cleaner.
is the engine body, 4 is the exhaust passage (exhaust manifold),
20 is a turbocharger, and an intake throttle valve 6 driven by a seven-diameter ram device 8 is interposed in an intake passage 2 upstream of the turbocharger 20.

排気通路4はターボチャージャ20」水流にて第1、第
2のEGR通路21.22を介して吸気通路(吸気マニ
ホールド)2と接続され、第1のEGR通路21にはダ
イヤイアラム装置23により駆動される第1のEGR制
御井24が介装される。
The exhaust passage 4 is connected to the intake passage (intake manifold) 2 via the first and second EGR passages 21 and 22 by the turbocharger 20'' water flow, and the first EGR passage 21 is connected to the intake passage 2 driven by the diaphragm device 23. A first EGR control well 24 is provided.

また、第2のEGR通路22にはダイヤイアラム装置2
5により駆動される第2のEGR制御井26が介装され
ると共に、その途中に例えば多管式の冷却器27が介装
される。
In addition, the second EGR passage 22 includes a dial diaphragm device 2.
A second EGR control well 26 driven by EGR control well 5 is interposed, and a multi-tube cooler 27, for example, is interposed therebetween.

冷却器27は内部に配管28.29を介して図示しない
エンジンラジェータからポンプにより冷却水が循環され
、排気通路4から第2のE G R通路22を通るEG
Rガスを冷却するようになっている。
Cooling water is circulated inside the cooler 27 by a pump from an engine radiator (not shown) through piping 28 and 29, and the EGR water is circulated from the exhaust passage 4 through the second EGR passage 22.
It is designed to cool R gas.

10はバキュームポンプ等からなる負圧源、12.30
,31..32は三方電磁弁で、三方電磁弁12.30
.32は通電ONのときボートlと肩とを連通して、負
圧源10からの負圧を前記各ダイヤ7ラム装置8,23
,25の圧力室9.33.34に導入し、絞り弁6を半
開、EGR制御井24,26を全開する。他方、通電O
FFのときボート!とnとを連通して、圧力室9 、3
3 、34をオ’) 7 イス35を介してエアクリー
ナ1側の大気に開放し、絞り弁6を全開、EGR制御弁
24.26を全閉する。
10 is a negative pressure source consisting of a vacuum pump, etc., 12.30
, 31. .. 32 is a three-way solenoid valve, three-way solenoid valve 12.30
.. Reference numeral 32 communicates the boat l and the shoulder when the power is ON, and transfers the negative pressure from the negative pressure source 10 to each of the diamond 7 ram devices 8 and 23.
, 25 into the pressure chambers 9, 33, and 34, the throttle valve 6 is half-opened, and the EGR control wells 24 and 26 are fully opened. On the other hand, energized O
FF time boat! and n to communicate with each other to form pressure chambers 9 and 3.
3 and 34 to the atmosphere via the chair 35, fully open the throttle valve 6, and fully close the EGR control valves 24 and 26.

また、三方電磁弁31は通電ONのときボートlを閉じ
るが、通電OFFのときボートβとnとを連通して、圧
力室34にオリフィス15を介してエアクリーナ1側か
ら大気を導入、即ち三方電磁弁32がONのとき圧力室
34に導入される負圧を減圧し、EGR制御井26を半
開するようになっている。
In addition, the three-way solenoid valve 31 closes the boat l when the energization is ON, but communicates the boats β and n when the energization is OFF, and introduces atmospheric air from the air cleaner 1 side into the pressure chamber 34 via the orifice 15. When the solenoid valve 32 is ON, the negative pressure introduced into the pressure chamber 34 is reduced, and the EGR control well 26 is half-opened.

一方、エンジンの運転状態を検出する手段として燃料噴
射ポンプ36に負荷センサ18とクランクプーリ部37
に回転センサ19と、エンジンの暖機状態を検出する手
段としてエンジン冷却水温を検出する水温センサ38と
が設けられ、これらの検出信号は制御回路(制御手段)
39に送られる。
On the other hand, the fuel injection pump 36 includes a load sensor 18 and a crank pulley portion 37 as means for detecting the operating state of the engine.
A rotation sensor 19 and a water temperature sensor 38 for detecting engine cooling water temperature as means for detecting the warm-up state of the engine are provided, and these detection signals are sent to a control circuit (control means).
Sent to 39th.

そして、制御回路39はこれらの検出信号と予め記憶し
た制御モードに基づいて前記各三方電磁弁12,30,
31.32を0N−OFF制御する。
Then, the control circuit 39 controls each of the three-way solenoid valves 12, 30,
31.32 is controlled ON-OFF.

具体的には、水温センサ38の検出値が所定値よりも高
い暖機終了後の運転時では、運転状態に応じて絞り弁6
と第1、第2のEGR制御井24゜26を第3図、第4
図のA、B、、C,Dのステージに示される開度に制御
するように、三方電磁弁12゜30.31,32をON
 −0−FI−、する。
Specifically, during operation after the end of warm-up when the detected value of the water temperature sensor 38 is higher than a predetermined value, the throttle valve 6 is closed depending on the operating state.
and the first and second EGR control wells 24 and 26 in Figures 3 and 4.
Turn on the three-way solenoid valves 12, 30, 31, and 32 to control the opening degrees shown in stages A, B, , C, and D in the figure.
-0-FI-, do.

他方、水温センサ38の検出値が所定値よりも低い暖機
中では、運転状態に応じて絞り弁6と第1、第2のE 
G R制御弁24.26を第3図、第5図のり、E、F
のステージに示される開度に制御するように、三方電磁
弁12.3 ?、31.32を0N−OFFする。
On the other hand, during warm-up when the detected value of the water temperature sensor 38 is lower than a predetermined value, the throttle valve 6 and the first and second E
G R control valve 24.26 in Figure 3, Figure 5, E, F
Three-way solenoid valve 12.3 ? , 31.32 is turned OFF.

尚、水温センサ38の検出値が極めて低いときには、上
記条件に拘わらず、第3図の1)ステージとなるように
三方電磁弁12.3(1,’31.32をQFFするよ
うになっている。第6図に水温による制御フローを示す
と、水温TがTI(低温設定値)よりも低いときには、
SlからS2に進みDステージが選択され、水温T h
fT 、よりも高く、T2(暖機設定値)よりも低いと
きに(ま、S + −S 3からS。
Incidentally, when the detected value of the water temperature sensor 38 is extremely low, regardless of the above conditions, the three-way solenoid valve 12.3 (1, '31.32 is QFFed so as to be in the 1) stage in Fig. 3. Figure 6 shows the control flow based on water temperature.When water temperature T is lower than TI (low temperature set value),
Proceeding from Sl to S2, the D stage is selected, and the water temperature T h
When fT is higher than , and lower than T2 (warm-up set value) (well, S + -S 3 to S.

に進み運転状態に応じてり、E、Fステージが選択され
、水温TfJtT2よりも高い時には、S5にて運転状
態に応じてA 、 B 、 C、I’)ステージが選択
される。
In step S5, stages E and F are selected depending on the operating condition, and when the water temperature is higher than TfJtT2, stages A, B, C, and I' are selected in accordance with the operating condition in step S5.

このように構成したので、エンジン冷却水温が所定値よ
りも低い暖機中は、第2EGR通路22のE G R制
御弁26が全閉状態に保たれ、絞り弁6と第1 EGR
通路21のEGR制御弁24が駆動される(第3図、第
5図参照)。例えば、暖機アイドリング時(Eステージ
)には、三方電磁弁12゜30がONとなり、絞り弁6
が半開、第1EGR制御弁24が全開される。また、こ
の状態がら負荷、回転数がいくらか上昇すると(Fステ
ージ)、三方電磁弁12がOFFとなり、絞り弁6が全
開される。
With this configuration, during warm-up when the engine cooling water temperature is lower than a predetermined value, the EGR control valve 26 of the second EGR passage 22 is kept fully closed, and the throttle valve 6 and the first EGR control valve 26 are kept fully closed.
The EGR control valve 24 in the passage 21 is activated (see FIGS. 3 and 5). For example, during warm-up idling (E stage), the three-way solenoid valve 12°30 is turned on, and the throttle valve 6
is half open, and the first EGR control valve 24 is fully opened. Furthermore, when the load and rotational speed increase somewhat in this state (F stage), the three-way solenoid valve 12 is turned off and the throttle valve 6 is fully opened.

これにより、暖機中は第1 EGR通路21が開゛かれ
、第1 EGR通路21から運転状態に応じた量のEG
R4スが吸気通路2に導入される。
As a result, the first EGR passage 21 is opened during warm-up, and an amount of EGR corresponding to the operating state is discharged from the first EGR passage 21.
R4 gas is introduced into the intake passage 2.

したがって、その高温のEGR,fスにより吸気の温度
が高められ、暖機運転時のNOxの低減が図られると共
に、安定した燃焼を得ることができる。
Therefore, the temperature of the intake air is raised by the high-temperature EGR and f gas, reducing NOx during warm-up operation and achieving stable combustion.

また、暖機運転時には圧縮端温度が低いことに起因して
燃料の着火遅れ期間が増加し、その変動も大きいことか
ら、ディーゼルノックを起こしやすいが、このように高
温のE、G Rffスにより吸気を加熱することで、低
温時のディーゼルノックを防止できる。
In addition, during warm-up, the ignition delay period of the fuel increases due to the low compression end temperature, and its fluctuations are large, so diesel knock is likely to occur. By heating the intake air, diesel knock can be prevented at low temperatures.

さらには、始動直後等、低温の燃焼室壁面に付着した燃
料によりホワイトスモークが発生することがあるが、高
温のEGRtJ″スにより付着燃料の蒸発が促進され、
ホワイトスモークは減少する。
Furthermore, white smoke may be generated due to fuel adhering to the low-temperature combustion chamber wall immediately after startup, but the high-temperature EGRtJ'' gas accelerates the evaporation of the adhering fuel.
White smoke decreases.

一方、エンジン冷却水温が所定値を越え暖機を終了する
と、第1 EGR通路21のEGR制御弁24が全閉状
態に保たれ、絞り弁6と第2EGR通路22のEGR制
御弁26が駆動される(第3図、第4図参照)。例えば
、低速低負荷域(Aステージ)では、三方電磁弁12.
31.32がONとなり、絞り弁6が半開、第2EGR
制御弁26が全開される。また、この状態から部分負荷
域に入ると、負荷、回転数の上昇に応じて三方電磁弁1
2がOFFとなり絞り弁6が全開され(Bステージ)、
さらに三方電磁弁31がOFFとなり第2EGR制御井
26が半開される(Cステージ)。
On the other hand, when the engine cooling water temperature exceeds a predetermined value and warm-up is completed, the EGR control valve 24 of the first EGR passage 21 is kept fully closed, and the throttle valve 6 and the EGR control valve 26 of the second EGR passage 22 are driven. (See Figures 3 and 4). For example, in the low speed and low load range (A stage), the three-way solenoid valve 12.
31 and 32 are turned on, throttle valve 6 is half open, and the second EGR
Control valve 26 is fully opened. In addition, when entering the partial load range from this state, the three-way solenoid valve 1
2 is turned off and the throttle valve 6 is fully opened (B stage).
Furthermore, the three-way solenoid valve 31 is turned off, and the second EGR control well 26 is half-opened (C stage).

これにより、暖機後の通常運転時には第2EGR通路2
2が開かれ、運転状態に応じた量のEGR〃スが冷却器
27を介装した第2EGR通路22を介して吸気通路2
に導入1きれるのである。
As a result, during normal operation after warming up, the second EGR passage 2
2 is opened, and an amount of EGR gas corresponding to the operating condition is supplied to the intake passage 2 through the second EGR passage 22 in which a cooler 27 is interposed.
The first introduction can be completed.

したがって、吸気通路2には□冷却器27内の冷却水に
より冷却された低温のり・GR,?’スが導入されるた
め、吸気の温度を上昇さi、るようなことはなく、所定
の吸気充填率を保り、ことができる。また、低温化によ
りEGR)Fス、鳴I密度′が高まるため、大量のEG
Rを行う領域でも、゛運転状態に応じた適正量のEGR
ffスな還流、することができる。
Therefore, the intake passage 2 is filled with low-temperature glue/GR, which is cooled by the cooling water in the cooler 27. Since the intake air is introduced, the temperature of the intake air does not increase, and a predetermined intake air filling rate can be maintained. In addition, lowering the temperature increases the EGR)
Even in the area where R is performed, the appropriate amount of EGR according to the driving condition
ffs reflux can be done.

この結果、スモークやバパ−ティキュレートの増加を招
いたり、燃費を悪托させるようなことは防止されると共
に、NOxを十分に低減することが可能となる。
As a result, it is possible to prevent an increase in smoke and vapor and to reduce fuel consumption, and it is also possible to sufficiently reduce NOx.

尚、高負荷域や高回転域では絞り弁6が全開、第1、第
2EGR制御″+P24ン26が全閉され(Dステージ
)、EGRが停止さ・川る。また、暖機中に比較的負荷
や回転数が高く・なった場合、さらには−ンジン冷却水
温が極めて・低ニー場合にも、同様にEGRが停止され
る= 第7図〜第10図は本発明゛の他の実施例を示すもので
、前記実施例の制御モ1−ドに加えて、所定の運転状態
のと外に第1と第2のF!: G R制御弁24.26
を同時に開き、第1 EG R通路21から高温のEG
 RIfスを、第2 r’: G R通路22から冷却
された低温のE G、 Rffスを同時に速流するよう
にしたものである。
In addition, in the high load range and high rotation range, the throttle valve 6 is fully opened, the first and second EGR control'' + P24-in 26 are fully closed (D stage), and the EGR is stopped. EGR is similarly stopped when the engine load or rotational speed becomes high, or even when the engine cooling water temperature is extremely low. Figures 7 to 10 show other embodiments of the present invention. By way of example, in addition to the control mode 1 of the above embodiment, the first and second F!: G R control valves 24.
are opened at the same time, and the high temperature EG is discharged from the first EGR passage 21.
The low-temperature EG and Rff gases cooled from the second r': GR passage 22 are made to flow at a high speed at the same time.

暖慨終f後の低速低負荷域でもアイドリング時にはより
多(E G RIfスを導入することがof能であり、
この時第7図、第8図の■ステージに示すように絞り弁
6を半開、第1、第2 E G R制御弁24.26を
全開させで、多量のE G R、fスを還流するように
しでいる。
Even in the low speed and low load range after the end of the warm-up period, it is possible to introduce more E
At this time, the throttle valve 6 is half-opened and the first and second EGR control valves 24 and 26 are fully opened, as shown in stage 2 in Figs. 7 and 8, to recirculate a large amount of EGR and fs. I'm trying to do that.

アイドリング時には、燃焼室内の温度レベルが比較的低
いので、低温のE G RWスとともに高温のEGRf
fスを導入しても、吸気充填率にそれ+2と影響を与え
ることはなく、また高温ガスを導入することで燃焼室内
の温度レベルがある程度高まるため、燃焼が安定するよ
うになり、このためNOxが十分に低減されると共に、
l−ICの低減お上びアイドリング時の騒音の低減が図
れる。
During idling, the temperature level inside the combustion chamber is relatively low, so the high temperature EGRf is generated along with the low temperature EGRW gas.
Even if F gas is introduced, it will not affect the intake air filling rate by +2, and by introducing high temperature gas, the temperature level in the combustion chamber will increase to a certain extent, so combustion will become stable. While NOx is sufficiently reduced,
It is possible to reduce l-IC and reduce noise during idling.

・ただし、各ステージ■、■、v、 vr、■、■はそ
れぞれ第3図のASB、C,E、F、Dに対応する。
・However, each stage ■, ■, v, vr, ■, ■ corresponds to ASB, C, E, F, D in FIG. 3, respectively.

尚、暖機後の低速低負荷域では、第10図のように■ス
テージに制御しても良い。
In addition, in the low speed and low load range after warming up, control may be performed to the ■ stage as shown in FIG.

(発明の効果) 以上のように本発明によれば、エンジンの運転状態と暖
機状態に応じ、ftSiの1ΣGR通路から高温のF:
 G RIfスを、第2のE G R通路から冷却器を
介して低温のEG)’?、fスを還流するので、暖機中
におけるNOx、ホワイトスモーク、パーティキュレー
トおよびディーゼルノックの低減と、暖機後における燃
費、スモーク、パーティキュレートの増加を抑制しなが
らNOにの低減とが図れる。
(Effects of the Invention) As described above, according to the present invention, high temperature F:
The low-temperature EG is passed from the second EGR passage through the cooler. , f gas is recirculated, it is possible to reduce NOx, white smoke, particulates, and diesel knock during warm-up, and to reduce NOx while suppressing increases in fuel consumption, smoke, and particulates after warm-up.

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

第1図は本発明のhVI成図、第2図は本発明の実施例
を示す構成図、第3図〜第5図はその制御モードを示す
表目と線図、第6図はその制御動作を示すフローチャー
ト、第7図〜第10図は本発明の他の実施例を示す制御
モードの表目と線図、第11図、第12図は、従来例を
示す概略構成図とその制御モードの表目である。 2・・・吸気通路、4・・・排気進路、6・・・絞り弁
、18・・・負荷センサ、19・・・回転センサ、21
・・・第1のEGR辿略、22・・・第20E G R
通路、24・・・第1のEGR制御弁、26・・・第2
のEGR制御弁、27・・・冷却器、38・・・水温セ
ンサ、39・・・制御回路。 小へへ・\脇を回O
Fig. 1 is an hVI diagram of the present invention, Fig. 2 is a configuration diagram showing an embodiment of the invention, Figs. 3 to 5 are tables and diagrams showing its control mode, and Fig. 6 is its control. A flowchart showing the operation, FIGS. 7 to 10 are tables and diagrams of control modes showing other embodiments of the present invention, and FIGS. 11 and 12 are schematic configuration diagrams showing conventional examples and their control. This is the mode table. 2... Intake passage, 4... Exhaust path, 6... Throttle valve, 18... Load sensor, 19... Rotation sensor, 21
... 1st EGR trace, 22... 20th EGR
Passage, 24...first EGR control valve, 26...second
EGR control valve, 27... Cooler, 38... Water temperature sensor, 39... Control circuit. Go to small・\Turn around the side O

Claims (1)

【特許請求の範囲】[Claims]  吸気通路の途中に吸気絞り弁を介装し、この絞り弁下
流の吸気通路と排気通路とを連通する第1、第2のEG
R通路を形成し、第1のEGR通路に第1のEGR制御
弁を、第2のEGR通路に第2のEGR制御弁と還流排
気を冷却する冷却器を介装する一方、エンジンの運転状
態を検出する手段と、暖機状態を検出する手段と、これ
らの検出値に基づいて前記絞り弁と、第1、第2のEG
R制御弁の開度を制御する制御手段とを設けたことを特
徴とするディーゼルエンジンの排気還流装置。
An intake throttle valve is interposed in the middle of the intake passage, and first and second EGs communicate the intake passage downstream of the throttle valve and the exhaust passage.
An R passage is formed, and the first EGR passage is provided with a first EGR control valve, and the second EGR passage is provided with a second EGR control valve and a cooler that cools the recirculated exhaust gas. means for detecting a warm-up state; and means for detecting a warm-up state; and a means for detecting a warm-up state;
1. An exhaust gas recirculation device for a diesel engine, comprising a control means for controlling the opening degree of an R control valve.
JP60146244A 1985-07-03 1985-07-03 Exhaust reflux device of diesel engine Pending JPS627943A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60146244A JPS627943A (en) 1985-07-03 1985-07-03 Exhaust reflux device of diesel engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60146244A JPS627943A (en) 1985-07-03 1985-07-03 Exhaust reflux device of diesel engine

Publications (1)

Publication Number Publication Date
JPS627943A true JPS627943A (en) 1987-01-14

Family

ID=15403351

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60146244A Pending JPS627943A (en) 1985-07-03 1985-07-03 Exhaust reflux device of diesel engine

Country Status (1)

Country Link
JP (1) JPS627943A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0740056A2 (en) * 1995-04-27 1996-10-30 Toyota Jidosha Kabushiki Kaisha Direct injection type compression ignition engine
JPH09508691A (en) * 1995-03-31 1997-09-02 カミンス エンジン カンパニー、インコーポレイテッド Cooled exhaust gas recirculation system with load bypass and ambient bypass
EP1156201A3 (en) * 2000-05-17 2003-04-16 Toyota Jidosha Kabushiki Kaisha Internal combustion engine and method for controlling the internal combustion engine
US7743816B2 (en) 2002-05-15 2010-06-29 Behr Gmbh & Co. Kg Switchable waste gas exchanger

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09508691A (en) * 1995-03-31 1997-09-02 カミンス エンジン カンパニー、インコーポレイテッド Cooled exhaust gas recirculation system with load bypass and ambient bypass
EP0740056A2 (en) * 1995-04-27 1996-10-30 Toyota Jidosha Kabushiki Kaisha Direct injection type compression ignition engine
EP0740056A3 (en) * 1995-04-27 1996-11-20 Toyota Jidosha Kabushiki Kaisha Direct injection type compression ignition engine
US5768887A (en) * 1995-04-27 1998-06-23 Toyota Jidosha Kabushiki Kaisha Direct injection type compression ignition engine and method of use
EP1156201A3 (en) * 2000-05-17 2003-04-16 Toyota Jidosha Kabushiki Kaisha Internal combustion engine and method for controlling the internal combustion engine
US6634345B2 (en) 2000-05-17 2003-10-21 Toyota Jidosha Kabushiki Kaisha Internal combustion engine and method for controlling the internal combustion engine
US7743816B2 (en) 2002-05-15 2010-06-29 Behr Gmbh & Co. Kg Switchable waste gas exchanger
US8365813B2 (en) 2002-05-15 2013-02-05 Behr Gmbh & Co. Kg Switchable waste gas exchanger

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