JPH074321A - Exhaust gas recirculation device - Google Patents
Exhaust gas recirculation deviceInfo
- Publication number
- JPH074321A JPH074321A JP5146461A JP14646193A JPH074321A JP H074321 A JPH074321 A JP H074321A JP 5146461 A JP5146461 A JP 5146461A JP 14646193 A JP14646193 A JP 14646193A JP H074321 A JPH074321 A JP H074321A
- Authority
- JP
- Japan
- Prior art keywords
- valve
- valve opening
- egr
- amount
- passage
- 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.)
- Withdrawn
Links
Classifications
-
- 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
Landscapes
- Exhaust-Gas Circulating Devices (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、エンジンから排出され
る排ガスの一部を吸気通路に戻す排ガス再循環装置、特
に排気路と吸気路とを結ぶ再循環路に流量制御弁を設け
て、同弁の開弁量を運転条件に応じて増減制御する排ガ
ス再循環装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas recirculation device for returning a part of exhaust gas discharged from an engine to an intake passage, and more particularly to a recirculation passage connecting an exhaust passage and an intake passage with a flow control valve. The present invention relates to an exhaust gas recirculation device that controls the opening amount of the valve according to operating conditions.
【０００２】[0002]
【従来の技術】一般に、エンジン排ガス中のＮＯｘ（窒
素酸化物）の発生を低減するため、排ガスの一部を再度
吸気路に戻す排ガス再循環装置（以後単にＥＧＲ装置と
記す）が使用されている。例えば、図８に示すように、
エンジン１の吸気路２と排気路３との間に配設されるＥ
ＧＲ装置はバキュームポンプ４で負圧を発生させ、エン
ジンの運転情報を受ける制御手段５からの制御信号に応
じ駆動する負圧制御弁６によってその負圧を適切な値に
制御し、該負圧を排ガス再循環制御弁（以後単にＥＧＲ
弁と称する）９のダイアフラム室７内に供給する。これ
によって、排ガス再循環路（以後単にＥＧＲ路と称す
る）８の開口面積を変化させて排ガス再循環量、つまり
ＥＧＲ量を制御していた。2. Description of the Related Art Generally, in order to reduce the generation of NOx (nitrogen oxide) in engine exhaust gas, an exhaust gas recirculation device (hereinafter simply referred to as an EGR device) for returning a part of exhaust gas to an intake passage is used. There is. For example, as shown in FIG.
E provided between the intake passage 2 and the exhaust passage 3 of the engine 1
The GR device causes the vacuum pump 4 to generate a negative pressure, and controls the negative pressure to an appropriate value by a negative pressure control valve 6 that is driven according to a control signal from a control means 5 that receives engine operation information. The exhaust gas recirculation control valve (hereinafter simply referred to as EGR
(Referred to as a valve) 9 is supplied into the diaphragm chamber 7. As a result, the opening area of the exhaust gas recirculation path (hereinafter simply referred to as the EGR path) 8 is changed to control the exhaust gas recirculation amount, that is, the EGR amount.
【０００３】この際、制御手段５は、エンジンの運転域
が変動する毎に新たに目標とするＥＧＲ量を算出し、現
在の開弁量を目標ＥＧＲ量相当の開弁量に増減修正し、
常に、最適なＥＧＲ量を確保するようにしている。At this time, the control means 5 calculates a new target EGR amount each time the engine operating range fluctuates, and increases or decreases the current valve opening amount to a valve opening amount corresponding to the target EGR amount.
The optimum EGR amount is always ensured.
【０００４】[0004]
【発明が解決しようとする課題】処で、通常のＥＧＲ装
置は、吸気路２と排気路３との間に単一のＥＧＲ路８を
設け、同通路に単一のＥＧＲ弁９を設けて、ＥＧＲ路８
の開口面積を変化させてＥＧＲ量を制御していた。この
ため、大排気量のエンジンになると、必要とされるＥＧ
Ｒ量も多くなり、ＥＧＲ弁９が大型化し、弁体９０１自
体が大きくなり、結果として、応答性が悪化し易い。し
かも、ＥＧＲ弁の弁体９０１自体が大きくなると単位バ
ルブリフト量当たりのＥＧＲ量（流量）も大きくなり、
結果として、精度の良い制御ができず、この点でも目標
開弁量に切換えるのにようする時間がかかり問題と成っ
ている。本発明の目的は、ＥＧＲ弁の切換え制御時にお
ける応答性及び切換え精度を向上できる排ガス再循環装
置を提供することにある。By the way, in a normal EGR device, a single EGR passage 8 is provided between the intake passage 2 and the exhaust passage 3, and a single EGR valve 9 is provided in the same passage. , EGR road 8
The EGR amount was controlled by changing the opening area of the. Therefore, when the engine has a large displacement, the required EG
The amount of R also increases, the EGR valve 9 becomes large, the valve body 901 itself becomes large, and as a result, the responsiveness is likely to deteriorate. Moreover, when the valve body 901 of the EGR valve itself becomes large, the EGR amount (flow rate) per unit valve lift amount also becomes large,
As a result, accurate control cannot be performed, and in this respect as well, it takes time to switch to the target valve opening amount, which is a problem. An object of the present invention is to provide an exhaust gas recirculation device that can improve responsiveness and switching accuracy during EGR valve switching control.
【０００５】[0005]
【課題を解決するための手段】上述の目的を達成するた
めに、本発明はディーゼルエンジンの排気路の排ガスを
吸気路に戻す第１及び第２排ガス再循環路と、上記第１
排ガス再循環路に設けられ同路の流路断面積を可変とす
る第１流量制御弁と、上記第２排ガス再循環路に設けら
れ同路の流路断面積を可変とする第２流量制御弁と、上
記ディーゼルエンジンの燃料噴射ポンプのレバー開度信
号を出力するレバー開度センサと、上記ディーゼルエン
ジンのエンジン回転速度信号を出力するエンジン回転セ
ンサと、上記第１及び第２流量制御弁の開弁量信号を出
力する第１及び第２弁開度センサと、上記レバー開度信
号及び上記エンジン回転速度信号に基づき上記第１及び
第２流量制御弁の目標再循環量相当の各開弁量をそれぞ
れ算出し、同各開弁量に上記第１及び第２流量制御弁を
制御する制御手段とを有し、上記制御手段は上記第１及
び第２流量制御弁の各開弁量と上記目標再循環量相当の
開弁量との各偏差をそれぞれ算出すると共に、それら各
偏差が設定ずれ幅を上回る間は上記第１及び第２流量制
御弁を同時に上記各偏差を打ち消す開弁量に制御し、上
記各偏差が上記設定ずれ幅内にある間は上記第１及び第
２流量制御弁の内の一方のみを上記偏差を打ち消す開弁
量に制御することを特徴とする。In order to achieve the above-mentioned object, the present invention provides first and second exhaust gas recirculation passages for returning exhaust gas in an exhaust passage of a diesel engine to an intake passage, and the above first embodiment.
A first flow rate control valve that is provided in the exhaust gas recirculation passage and has a variable flow passage cross-sectional area, and a second flow rate control that is provided in the second exhaust gas recirculation passage and that has a variable flow passage cross-sectional area A valve, a lever opening sensor that outputs a lever opening signal of the fuel injection pump of the diesel engine, an engine rotation sensor that outputs an engine rotation speed signal of the diesel engine, and the first and second flow rate control valves. First and second valve opening sensors that output a valve opening signal, and each valve opening corresponding to the target recirculation amount of the first and second flow control valves based on the lever opening signal and the engine rotation speed signal And a control means for controlling the first and second flow rate control valves to calculate the respective valve opening amounts and the control means controls the valve opening amounts of the first and second flow rate control valves. Each deviation from the valve opening amount equivalent to the above target recirculation amount While calculating each, while the respective deviations exceed the set deviation range, the first and second flow rate control valves are simultaneously controlled to valve opening amounts that cancel the respective deviations, and the deviations are within the set deviation range. In the meantime, only one of the first and second flow rate control valves is controlled to the valve opening amount that cancels the deviation.
【０００６】[0006]
【作用】ここでの制御手段は、第１及び第２流量制御弁
の各開弁量と目標再循環量相当の開弁量との各偏差をそ
れぞれ算出し、次いで、それら各偏差が設定ずれ幅外に
ある間には、第１及び第２流量制御弁を各偏差を打ち消
す開弁量に同時に制御するので、応答性を向上でき、各
偏差が設定ずれ幅内にある間は第１及び第２流量制御弁
の内の一方のみを偏差を打ち消す開弁量に制御するの
で、精度良く開弁量を調整できる。The control means here calculates the respective deviations between the respective valve opening amounts of the first and second flow rate control valves and the valve opening amounts corresponding to the target recirculation amounts, and then the respective deviations are set to be different from each other. While it is out of the range, the first and second flow rate control valves are simultaneously controlled to the valve opening amount that cancels each deviation, so that the responsiveness can be improved, and while each deviation is within the set deviation width, Since only one of the second flow rate control valves is controlled to the valve opening amount that cancels the deviation, the valve opening amount can be adjusted accurately.
【０００７】[0007]
【実施例】図１の排ガス再循環装置はディーゼルエンジ
ン（以後単にエンジンと記す）１０に装着されている。
このエンジン１０の吸気路Ｉは、大気をエアクリーナ１
１を通して吸入し、この新気をエンジン本体１２の図示
しないシリンダ内に供給する。一方、排気路Ｅは上述の
シリンダより排出された排気をマフラー１３を通して大
気放出する。このエンジン１０の排ガス再循環装置は排
気路Ｅ中の排ガスの一部をＥＧＲガスとして吸気路Ｉの
新気中に還流させ、燃焼室温度の上昇を抑え、ＮＯX排
出量の低減を図れる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The exhaust gas recirculation system of FIG. 1 is installed in a diesel engine (hereinafter simply referred to as engine) 10.
The intake passage I of the engine 10 uses the air cleaner 1 for the atmosphere.
1, and the fresh air is supplied into a cylinder (not shown) of the engine body 12. On the other hand, the exhaust passage E discharges the exhaust exhausted from the cylinder through the muffler 13 to the atmosphere. The exhaust gas recirculation system for the engine 10 allows a part of the exhaust gas in the exhaust passage E to be recirculated to the fresh air in the intake passage I as EGR gas to suppress an increase in the temperature of the combustion chamber and reduce the NO X emission amount.
【０００８】ここで、排ガス再循環装置は吸気路２と排
気路３との間を互いに並列的に結ぶ一対の第１及び第２
排ガス再循環路（以後単に第１及び第２ＥＧＲ路と記
す）ｒ１，ｒ２と、第１ＥＧＲ路ｒ１に設けられ同路の
流路断面積を可変とする第１流量制御弁（以後単に第１
ＥＧＲ弁と記す）１４と、第２ＥＧＲ路ｒ２に設けられ
同路の流路断面積を可変とする第２流量制御弁（以後単
に第２ＥＧＲ弁と記す）１５と、ディーゼルエンジン１
０の図示しない燃料噴射ポンプのレバー開度θL信号を
出力するレバー開度センサ１６と、ディーゼルエンジン
１０のエンジン回転速度Ｎｅ信号を出力するエンジン回
転センサ１７と、第１及び第２ＥＧＲ弁１４，１５の開
弁量相当のリフト量ｈ１，ｈ２信号を出力する第１及び
第２弁開度センサ１８，１９と、レバー開度θL信号及
びエンジン回転速度Ｎｅ信号に基づき第１及び第２ＥＧ
Ｒ弁１４，１５を制御するコントローラ２０とを備え
る。Here, the exhaust gas recirculation device has a pair of first and second exhaust passages 3 and 3 which connect the intake passage 2 and the exhaust passage 3 in parallel with each other.
Exhaust gas recirculation passages (hereinafter simply referred to as first and second EGR passages) r1 and r2, and a first flow control valve (hereinafter simply referred to as first passage control valve) provided in the first EGR passage r1 and having a variable passage cross-sectional area.
EGR valve) 14, a second flow rate control valve (hereinafter simply referred to as a second EGR valve) 15 that is provided in the second EGR passage r2 and has a variable flow passage cross-sectional area, and the diesel engine 1
0, a lever opening sensor 16 that outputs a lever opening θ L signal of a fuel injection pump (not shown), an engine rotation sensor 17 that outputs an engine rotation speed Ne signal of the diesel engine 10, the first and second EGR valves 14, First and second valve opening sensors 18, 19 that output lift amounts h1, h2 signals corresponding to the valve opening amount of 15, and first and second EGs based on the lever opening θ L signal and the engine rotation speed Ne signal.
The controller 20 for controlling the R valves 14 and 15 is provided.
【０００９】第１ＥＧＲ弁１４は第１ＥＧＲ路ｒ１の流
路面積を増減操作する弁体１４１と同弁体に一体的に接
続されるダイアフラム１４２とを有し、このダイアフラ
ム１４２は容器１４６内を大気開放室１４３と負圧室１
４４とに区分し、両室の圧力差及び戻しばね１４５の閉
弁方向への弾性力とのバランス位置、即ち、リフト量ｈ
１に弁体１４１を保持する。なお、弁体１４１の上端部
にはリフト量ｈ１に応じた信号を出力できるポジション
センサとしての第１弁開度センサ１８が接続されてい
る。The first EGR valve 14 has a valve body 141 for increasing / decreasing the flow passage area of the first EGR passage r1 and a diaphragm 142 which is integrally connected to the valve body 141. Open chamber 143 and negative pressure chamber 1
44, and the balance position of the pressure difference between both chambers and the elastic force of the return spring 145 in the valve closing direction, that is, the lift amount h.
The valve body 141 is held at 1. A first valve opening sensor 18 as a position sensor capable of outputting a signal according to the lift amount h1 is connected to the upper end of the valve body 141.
【００１０】ここで負圧室１４４にはソレノイドバルブ
である第１切換弁２１を介し真空ポンプ２２あるいは大
気開放口２１１が連通可能である。第１切換弁２１はコ
ントローラ２０に接続され、同コントローラからの出力
信号を受けて、デューティー作動する。即ち、ここでの
第１切換弁２１は入力されたデューティー比の増加に比
例して負圧値を大きくし、これにより負圧室１４４の負
圧値をデューティー比の増加に比例して大きくし、弁体
１４１のリフト量を大きくし、第１排ガス再循環路ｒ１
の流路面積を大きくし、再循環量であるＥＧＲ量を大き
くでき、逆に、第１切換弁２１のデューティー比を減ず
ることによって、再循環量であるＥＧＲ量を小さくでき
る。A vacuum pump 22 or an atmosphere opening port 211 can communicate with the negative pressure chamber 144 via a first switching valve 21 which is a solenoid valve. The first switching valve 21 is connected to the controller 20, receives an output signal from the controller 20, and is duty-operated. That is, the first switching valve 21 here increases the negative pressure value in proportion to the increase in the input duty ratio, and thereby increases the negative pressure value in the negative pressure chamber 144 in proportion to the increase in the duty ratio. , The lift amount of the valve body 141 is increased, and the first exhaust gas recirculation path r1
The EGR amount, which is the recirculation amount, can be increased by enlarging the flow path area of the above, and conversely, the EGR amount, which is the recirculation amount, can be reduced by reducing the duty ratio of the first switching valve 21.
【００１１】同様に、第２ＥＧＲ弁１５は第２ＥＧＲ路
ｒ２の流路面積を増減操作する弁体１５１と、容器１５
６内を大気開放室１５３と負圧室１５４とに区分するダ
イアフラム１５２と、ダイアフラム１５２に閉弁方向へ
の弾性力を加える戻しばね１４５とを有し、弁体１５１
をリフト量ｈ２に保持する。弁体１５１にはリフト量ｈ
２に応じた信号を出力できる第２弁開度センサ１９が接
続されている。さらに、負圧室１５４には第２切換弁２
３を介し真空ポンプ２２あるいは大気開放口２３１が連
通可能である。第２切換弁２３もコントローラ２０から
の出力信号を受けて、デューティー比の増加に比例して
負圧値を大きくし、これにより弁体１５１のリフト量を
大きくし、第２排ガス再循環路ｒ２の流路面積を大きく
し、ＥＧＲ量を大きくでき、逆に、第２切換弁２３のデ
ューティー比を減ずることによってＥＧＲ量を小さくで
きる。Similarly, the second EGR valve 15 includes a valve body 151 for increasing / decreasing the flow passage area of the second EGR passage r2, and a container 15.
The valve body 151 includes a diaphragm 152 that divides the inside of the chamber 6 into an atmosphere open chamber 153 and a negative pressure chamber 154, and a return spring 145 that applies an elastic force to the diaphragm 152 in the valve closing direction.
Is held at the lift amount h2. The lift amount h is applied to the valve body 151.
A second valve opening sensor 19 that can output a signal corresponding to 2 is connected. Further, the negative pressure chamber 154 has the second switching valve 2
The vacuum pump 22 or the atmosphere opening port 231 can communicate with each other through 3. The second switching valve 23 also receives the output signal from the controller 20 and increases the negative pressure value in proportion to the increase in the duty ratio, thereby increasing the lift amount of the valve body 151 and increasing the second exhaust gas recirculation path r2. The flow passage area can be increased and the EGR amount can be increased, and conversely, the EGR amount can be decreased by reducing the duty ratio of the second switching valve 23.
【００１２】ここで、図２及び図３に示すように、同じ
ＥＧＲ量を制御するに当たって、１個のＥＧＲ弁ｖａを
備えたＥＧＲ路ｒａによってＥＧＲ量を制御する場合
と、２個の同一のＥＧＲ弁ｖｂを備えたＥＧＲ路ｒｂ，
ｒｂによってＥＧＲ量を制御する場合とを比較する。１
個のＥＧＲ弁ｖａを備えたＥＧＲ路ｒａの通路面積π×
（ａ／２）2と、２個のＥＧＲ弁ｖｂ，ｖｂを備えたＥ
ＧＲ路ｒｂ，ｒｂの通路面積２×π×（ｂ／２）2とは
同じという条件より、下式（１）が成り立つ。Here, as shown in FIG. 2 and FIG. 3, in controlling the same EGR amount, the case where the EGR amount is controlled by the EGR path ra having one EGR valve va and the case where two EGR amounts are the same are controlled. EGR path rb with EGR valve vb,
The case of controlling the EGR amount by rb will be compared. 1
The passage area π of the EGR passage ra including the individual EGR valves va ×
E equipped with (a / 2) 2 and two EGR valves vb, vb
Under the condition that the passage areas 2 × π × (b / 2) 2 of the GR roads rb and rb are the same, the following expression (1) is established.
【００１３】π×（ａ／２）2＝２×π×（ｂ／２）2 ａ2＝２ｂ2 ａ＝√２ｂ・・・・・・・（１） さらに、通路面積π×（ａ／２）2と同一の通路面積を
得るための弁リフト量Ｈを求めるとする。ここで、図２
中の管路の通路面積π×（ａ／２）2とリング状の通路
面積ｓ（＝２×π×（ａ／２）×ｈ）とが等しいという
条件より、下式（２）が成り立つ。Π × (a / 2) 2 = 2 × π × (b / 2) 2 a 2 = 2b 2 a = √2b (1) Further, the passage area π × (a / 2) It is assumed that the valve lift amount H for obtaining the same passage area as 2 is obtained. Here, FIG.
The following equation (2) is established under the condition that the passage area π × (a / 2) 2 of the inner pipeline is equal to the ring-shaped passage area s (= 2 × π × (a / 2) × h). .
【００１４】 π×（ａ／２）2＝２×π×（ａ／２）×Ｈ Ｈ＝ａ／４・・・・・・・（２） 故に、通路面積π×（ａ／２）2と同一の通路面積を得
るための必要リフトＨは、通路内径の１／４となる。Ｅ
ＧＲ弁の径がａではａ／４、ＥＧＲ弁の径がｂではｂ／
４となる。この点を考慮して流量ＱとＥＧＲ弁のリフト
量の関係を図示すると、図４のようになる。図４より明
らかなように、目標再循環量Ｑ０を得るに当たり、単一
のＥＧＲ弁（ｖａ）を制御する場合に比較して、これと
同一の流量Ｑ０を２個のＥＧＲ弁（ｖｂ，ｖｂ）を同時
制御して得る場合の方が単位リフト量Δｈ当たりの単位
流量変化分ΔＱ１（＜ΔＱ２）が小さく、切換制御時の
精度が良いことが明らかである。しかも、図５に示すよ
うに、２個のＥＧＲ弁を同時制御する場合の方が各弁が
軽量化されるので、切換えに要する時間ｔ２が１個のＥ
ＧＲ弁を切換え制御するに要する時間ｔ１よりも短くて
済み、制御する場合の応答性も単一の場合よりも優れる
ことが明らかである。Π × (a / 2) 2 = 2 × π × (a / 2) × H H = a / 4 ... (2) Therefore, the passage area π × (a / 2) 2 The required lift H for obtaining the same passage area as is 1/4 of the passage inner diameter. E
When the diameter of the GR valve is a, it is a / 4; when the diameter of the EGR valve is b, it is b /
It becomes 4. Considering this point, the relationship between the flow rate Q and the lift amount of the EGR valve is illustrated in FIG. As is apparent from FIG. 4, in obtaining the target recirculation amount Q0, the same flow rate Q0 as that of the two EGR valves (vb, vb) is used as compared with the case of controlling a single EGR valve (va). It is apparent that the unit flow rate change amount ΔQ1 (<ΔQ2) per unit lift amount Δh is smaller and the precision in the switching control is better in the case of simultaneously controlling (1). Moreover, as shown in FIG. 5, when the two EGR valves are controlled simultaneously, the weight of each valve is reduced, so that the time t2 required for switching is one E.
It is clear that the time required for switching control of the GR valve is shorter than t1, and that the response in the case of control is superior to that in the single case.
【００１５】このような点を考慮して図１の排ガス再循
環装置は第１及び第２ＥＧＲ路ｒ１，ｒ２を設け、そこ
に同一形状の第１及び第２ＥＧＲ弁１４，１５を配備
し、第１切換弁２１、第２切換弁２３を介しこれをコン
トローラ２０によって制御するもので、特に、第１及び
第２ＥＧＲ弁１４，１５の現リフト量ｈ１，ｈ２（ｈ１
＝ｈ２）と目標再循環量Ｑ０相当のリフト量ｈ０との偏
差ｄＡを算出すると共に、偏差ｄＡが設定ずれ幅−ｃ≦
ｄＡ≦ｂを上回る間は第１及び第２ＥＧＲ弁１４，１５
を同時に偏差ｄＡを打ち消す開弁量に制御し、偏差ｄＡ
が設定ずれ幅−ｃ≦ｄＡ≦ｂ内にある間は第１及び第２
ＥＧＲ弁１４，１５の内の一方のみをその偏差ｄＡを打
ち消すリフト量に制御するという機能を備える。以下、
このような装置の作動を図７のＥＧＲ制御ルーチン及び
図６の第１及び第２ＥＧＲ弁１４，１５のリフト量特性
に沿って説明する。In consideration of such a point, the exhaust gas recirculation system of FIG. 1 is provided with the first and second EGR passages r1 and r2, and the first and second EGR valves 14 and 15 of the same shape are provided therein, This is controlled by the controller 20 via the first switching valve 21 and the second switching valve 23. In particular, the current lift amounts h1 and h2 (h1 of the first and second EGR valves 14 and 15) are controlled.
= H2) and the lift amount h0 corresponding to the target recirculation amount Q0, the deviation dA is calculated, and the deviation dA is the set deviation width −c ≦.
While dA ≦ b is exceeded, the first and second EGR valves 14, 15
Is controlled to a valve opening amount that cancels the deviation dA at the same time.
Is within the setting deviation range −c ≦ dA ≦ b, the first and second
It has a function of controlling only one of the EGR valves 14 and 15 to a lift amount that cancels the deviation dA. Less than,
The operation of such a device will be described with reference to the EGR control routine of FIG. 7 and the lift amount characteristics of the first and second EGR valves 14 and 15 of FIG.
【００１６】エンジン１及び排ガス再循環装置が駆動す
ると、まず、第１及び第２弁開度センサ１８，１９より
第１及び第２ＥＧＲ弁１４，１５の開弁量相当のリフト
量ｈ１，ｈ２信号を取り込む。そして、ステップｓ２で
は現リフト量ｈ１，ｈ２よりこれらの内で小さい方の弁
１４，１５を設定しておく。次に、ステップｓ３ではレ
バー開度センサ１６からのレバー開度θL信号やエンジ
ン回転センサ１７からのエンジン回転速度Ｎｅ信号を取
り込むと共にこれらの値に相当する目標再循環量Ｑ０相
当の開弁量であるリフト量ｈ０（単一弁相当）を設定す
る。なお、この場合のリフト量ｈ０は単一弁での値であ
り、単一弁と同一の流量を２個の同一ＥＧＲ弁１４，１
５を同時制御することによって得られる場合の目標再循
環量Ｑ０相当の各リフト量はｈ０／２となる。When the engine 1 and the exhaust gas recirculation device are driven, first, the lift amount h1 and h2 signals corresponding to the opening amounts of the first and second EGR valves 14 and 15 are output from the first and second valve opening degree sensors 18 and 19, respectively. Take in. Then, in step s2, the valves 14 and 15 that are smaller than the current lift amounts h1 and h2 are set. Next, at step s3, the lever opening θ L signal from the lever opening sensor 16 and the engine rotation speed Ne signal from the engine rotation sensor 17 are fetched and the valve opening amount corresponding to the target recirculation amount Q0 corresponding to these values is obtained. The lift amount h0 (corresponding to a single valve) is set. The lift amount h0 in this case is a value for a single valve, and the same flow rate as the single valve is used for the two identical EGR valves 14, 1.
Each lift amount corresponding to the target recirculation amount Q0 when obtained by simultaneously controlling 5 becomes h0 / 2.
【００１７】ステップｓ４では第１及び第２ＥＧＲ弁１
４，１５の現再循環量Ｑｎ相当のリフト量ｈ１，ｈ２と
目標再循環量Ｑ０相当のリフト量ｈ０（単一弁相当）の
今回の偏差ｄＡを求める。この後、ステップｓ５におい
て、今回の偏差ｄＡが予め設定される許容幅−ａ≦ｄＡ
≦ａに有るか否か判断し、Ｙｅｓでリターンし、Ｎｏで
はステップｓ６、ｓ７に進む。Ｙｅｓ、即ち、目標再循
環量Ｑ０と現再循環量Ｑｎの偏差が許容幅−ａ≦ｄＡ≦
ａ内の場合とは、目標再循環量Ｑ０相当のリフト量ｈ０
（単一弁相当）と２個の同一ＥＧＲ弁１４，１５の各リ
フト量ｈ１，ｈ２の合計との差が極小さく、許容される
範囲内にある状態であり、これ以上の制御を不要とする
もので、図示しないメインルーチンにリターンする。At step s4, the first and second EGR valves 1
The deviations dA of the lift amounts h1 and h2 corresponding to the current recirculation amounts Qn of 4, 15 and the lift amount h0 corresponding to the target recirculation amount Q0 (corresponding to a single valve) are obtained. After that, in step s5, the deviation dA of this time is set to a preset allowable width −a ≦ dA.
It is determined whether or not ≦ a, the process returns with Yes, and if No, the process proceeds to steps s6 and s7. Yes, that is, the deviation between the target recirculation amount Q0 and the current recirculation amount Qn is the allowable range −a ≦ dA ≦
In the case of a, the lift amount h0 corresponding to the target recirculation amount Q0
The difference between (the equivalent of a single valve) and the total of the lift amounts h1 and h2 of the two identical EGR valves 14 and 15 is extremely small and is within the allowable range, and no further control is required. Then, the process returns to the main routine (not shown).
【００１８】他方、偏差ｄＡ＜−ａの場合にステップｓ
６に達すると、更に設定ずれ幅−ｃ内に偏差ｄＡが有る
か否か、即ち−ｃ≦ｄＡ≦−ａの判断が成され、設定ず
れ幅−ｃ内ではステップｓ８に達し、設定ずれ幅−ｃ以
上大きくずれている場合にはステップｓ９に進む。ステ
ップ８では、偏差ｄＡが設定ずれ幅−ｃ内にあるので、
第１及び第２ＥＧＲ弁１４，１５の内の一方、ここで
は、ステップｓ２で求めた現リフト量ｈ１，ｈ２の内で
小さい方の弁（例えば今回は第１ＥＧＲ弁１４と仮定す
る）のみを駆動するとして、その偏差ｄＡを打ち消すべ
く、リフト量ｈ１（＝ｈ０−ｈ２）に制御し、リターン
する。この場合、一方の第１ＥＧＲ弁１４のみを切換え
制御するので、単位リフト量Δｈ当たりの単位流量変化
分ΔＱが比較的小さく、切換制御時の精度が良く、早期
に制御が収束する利点がある。On the other hand, if the deviation dA <-a, the step s
When 6 is reached, it is further determined whether or not there is a deviation dA within the set deviation width -c, that is, -c≤dA≤-a is determined, and within the set deviation width -c, step s8 is reached and the set deviation width is reached. If the difference is more than -c, the process proceeds to step s9. At step 8, since the deviation dA is within the set deviation width -c,
Only one of the first and second EGR valves 14 and 15 is driven, here, the smaller valve (for example, the first EGR valve 14 is assumed this time) among the current lift amounts h1 and h2 obtained in step s2. However, in order to cancel the deviation dA, the lift amount h1 (= h0-h2) is controlled and the process returns. In this case, since only one of the first EGR valves 14 is switching-controlled, the unit flow rate change amount ΔQ per unit lift amount Δh is relatively small, the switching control accuracy is good, and the control converges early.
【００１９】ステップｓ９では偏差ｄＡが設定ずれ幅−
ｃを越えており、第１及び第２ＥＧＲ弁１４，１５を同
時に駆動するとして、その偏差ｄＡを打ち消すべく、リ
フト量｛２×ｈ１（ｏｒｈ２）＝ｈ０｝を達成するよう
に両弁を同時に同量制御し、リターンする。この場合、
両ＥＧＲ弁１４，１５を同時切換え制御するので、単位
リフト量Δｈ当たりの単位流量変化分が２×ΔＱとなっ
て比較的大きく、応答性の良い切換制御ができる。他
方、偏差ａ＜ｄＡの場合にステップｓ７に達すると、更
に設定ずれ幅ｂ内に偏差ｄＡが有るか否か、即ちａ≦ｄ
Ａ≦ｂの判断が成され、設定ずれ幅ｂ内ではステップｓ
１０に達し、設定ずれ幅ｂ以上大きくずれている場合に
はステップｓ１１に進む。In step s9, the deviation dA is the set deviation width-
c and the first and second EGR valves 14 and 15 are driven at the same time, both valves are simultaneously driven to achieve the lift amount {2 × h1 (orh2) = h0} in order to cancel the deviation dA. Control the quantity and return. in this case,
Since both EGR valves 14 and 15 are controlled to be switched at the same time, the amount of change in the unit flow rate per unit lift amount Δh is 2 × ΔQ, which is relatively large, and switching control with good responsiveness can be performed. On the other hand, when step s7 is reached when the deviation a <dA, whether the deviation dA is further within the set deviation width b, that is, a ≦ d
The determination of A ≦ b is made, and step s
When it reaches 10, and it is largely deviated by the set deviation width b or more, the process proceeds to step s11.
【００２０】ステップｓ１０では、偏差ｄＡが設定ずれ
幅ｂ内にあるので、第１及び第２ＥＧＲ弁１４，１５の
内の一方、ここでは、ステップｓ２で求めた現リフト量
ｈ１，ｈ２の内で小さい方の弁（例えば今回は第１ＥＧ
Ｒ弁１４と仮定する）のみを駆動するとして、その偏差
ｄＡを打ち消すべく、リフト量ｈ１（＝ｈ０−ｈ２）に
制御し、リターンする。この場合、一方の第１ＥＧＲ弁
１４のみを切換え制御するので、単位リフト量Δｈ当た
りの単位流量変化分ΔＱが比較的小さく、切換制御時の
精度が良く、早期に制御が収束する利点がある。ステッ
プｓ１１では偏差ｄＡが設定ずれ幅ｂを越えており、第
１及び第２ＥＧＲ弁１４，１５を同時に駆動するとし
て、その偏差ｄＡを打ち消すべく、リフト量｛２×ｈ１
（ｏｒｈ２）＝ｈ０｝を達成するように両弁を同時に同
量制御し、リターンする。この場合、両ＥＧＲ弁１４，
１５を同時切換え制御するので、単位リフト量Δｈ当た
りの単位流量変化分が２×ΔＱとなって比較的大きく、
応答性の良い切換制御ができる。At step s10, since the deviation dA is within the set deviation width b, one of the first and second EGR valves 14 and 15, that is, the current lift amounts h1 and h2 obtained at step s2 here. The smaller valve (eg this time the first EG
Assuming that only the R valve 14 is driven, the lift amount h1 (= h0-h2) is controlled to cancel the deviation dA, and the process returns. In this case, since only one of the first EGR valves 14 is switching-controlled, the unit flow rate change amount ΔQ per unit lift amount Δh is relatively small, the switching control accuracy is good, and the control converges early. In step s11, the deviation dA exceeds the set deviation width b, and it is assumed that the first and second EGR valves 14 and 15 are simultaneously driven, and the lift amount {2 × h1 is set to cancel the deviation dA.
Both valves are simultaneously controlled by the same amount so as to achieve (orh2) = h0}, and the process returns. In this case, both EGR valves 14,
Since 15 is controlled to be switched at the same time, the unit flow rate change per unit lift amount Δh is 2 × ΔQ, which is relatively large.
Switching control with good responsiveness can be performed.
【００２１】このように、目標再循環量Ｑ０と現再循環
量Ｑｎの偏差ｄＡが設定ずれ幅−ｃ≦ｄＡ≦ｂ内の場合
は、第１及び第２ＥＧＲ弁１４，１５の内、現リフト量
ｈ１，ｈ２の内で小さい方の弁のみを駆動し、その偏差
ｄＡを打ち消すリフト量ｈ１（＝ｈ０−ｈ２）に制御す
るので、単位リフト量Δｈ当たりの単位流量変化分ΔＱ
が比較的小さく、切換制御時の精度が良く、早期に制御
が収束し、しかも、現リフト量ｈ１，ｈ２の内で小さい
方の弁のみを駆動するので、両弁の相対的なリフト量の
相違を低減でき、同時駆動域に戻ったときの応答性が良
い。他方、偏差ｄＡが設定ずれ幅−ｃ≦ｄＡ≦ｂを越え
ている場合は、第１及び第２ＥＧＲ弁１４，１５を同時
に駆動し、その偏差ｄＡを打ち消すべく、リフト量｛２
×ｈ１（ｏｒｈ２）＝ｈ０｝を達成するように両弁を同
時切換え制御するので、単位リフト量Δｈ当たりの単位
流量変化分が２×ΔＱとなって比較的大きく、応答性の
良い切換制御ができる。As described above, when the deviation dA between the target recirculation amount Q0 and the current recirculation amount Qn is within the set deviation range −c ≦ dA ≦ b, the current lift of the first and second EGR valves 14 and 15 is increased. Only the smaller valve of the amounts h1 and h2 is driven and the lift amount h1 (= h0-h2) that cancels the deviation dA is controlled, so that the unit flow rate change amount ΔQ per unit lift amount Δh is controlled.
Is relatively small, the accuracy of the switching control is good, the control converges early, and only the smaller valve of the current lift amounts h1 and h2 is driven, so the relative lift amount of both valves is increased. The difference can be reduced, and the responsiveness when returning to the simultaneous drive range is good. On the other hand, when the deviation dA exceeds the set deviation range −c ≦ dA ≦ b, the first and second EGR valves 14 and 15 are simultaneously driven, and the lift amount {2 is set to cancel the deviation dA.
Since both valves are controlled to be simultaneously switched so as to achieve × h1 (orh2) = h0}, the unit flow rate change per unit lift amount Δh becomes 2 × ΔQ, which is relatively large, and the switching control with good responsiveness is achieved. it can.
【００２２】ここでは設定ずれ幅−ｃ≦ｄＡ≦ｂ内の場
合は、現リフト量ｈ１，ｈ２が小さい方の弁のみを駆動
したが、これの代えて、予め一方の弁に特定しておいて
も良い。更に、設定ずれ幅を−ｃ≦ｄＡ≦ｂとしたが、
その他のずれ幅を設定することもできる。In this case, if the set deviation range is within -c≤dA≤b, only the valve with the smaller current lift amount h1, h2 is driven, but instead of this, one valve is specified in advance. You may stay. Further, the setting deviation width is set to −c ≦ dA ≦ b,
Other shift widths can be set.
【００２３】[0023]
【発明の効果】以上のように、本発明は第１及び第２流
量制御弁の各開弁量と目標再循環量相当の開弁量との偏
差を算出し、その偏差が設定ずれ幅外にあると第１及び
第２流量制御弁を偏差を打ち消す開弁量に同時に制御す
るので、応答性の良く目標のＥＧＲ量に近付けることが
でき、しかも、偏差が設定ずれ幅内に達していると第１
及び第２流量制御弁の内の一方のみを偏差を打ち消す開
弁量に制御するので、精度良く目標のＥＧＲ量に制御を
収束させることができるという利点がある。As described above, according to the present invention, the deviation between each opening amount of the first and second flow control valves and the opening amount corresponding to the target recirculation amount is calculated, and the deviation is out of the set deviation range. Since the first and second flow rate control valves are simultaneously controlled to the valve opening amount that cancels the deviation, it is possible to approach the target EGR amount with good responsiveness, and the deviation is within the set deviation range. And the first
Since only one of the second flow rate control valve and the second flow rate control valve is controlled to the valve opening amount that cancels the deviation, there is an advantage that the control can be accurately converged to the target EGR amount.
【図１】本発明の排ガス再循環装置の概略全体構成図で
ある。FIG. 1 is a schematic overall configuration diagram of an exhaust gas recirculation device of the present invention.
【図２】同一の第１及び第２ＥＧＲ弁の拡大要部面図で
ある。FIG. 2 is an enlarged main surface view of the same first and second EGR valves.
【図３】単一のＥＧＲ弁の拡大要部面図である。FIG. 3 is an enlarged main surface view of a single EGR valve.
【図４】図２及び図３のＥＧＲ弁の流量−リフト量の特
性線図である。FIG. 4 is a characteristic diagram of flow rate-lift amount of the EGR valve of FIGS. 2 and 3.
【図５】図２及び図３のＥＧＲ弁の作動時の流量特性線
図である。FIG. 5 is a flow rate characteristic diagram when the EGR valve of FIGS. 2 and 3 is in operation.
【図６】図１の装置で用いる一対のＥＧＲ弁の流量−リ
フト量の特性線図である。6 is a characteristic diagram of flow rate-lift amount of a pair of EGR valves used in the apparatus of FIG.
【図７】図１の装置で用いるＥＧＲ制御ルーチンのフロ
ーチャートである。FIG. 7 is a flowchart of an EGR control routine used in the device of FIG.
【図８】従来装置の要部断面図である。FIG. 8 is a sectional view of a main part of a conventional device.
１０ エンジン １２ エンジン本体 １４ 第１ＥＧＲ弁 １５ 第２ＥＧＲ弁 １６ レバー開度センサ １７ エンジン回転センサ １８ 第１弁開度センサ １９ 第２弁開度センサ ２０ コントローラ ２１ 第１切換弁 ２３ 第２切換弁 Ｅ 排気路 Ｉ 吸気路 θL レバー開度信号 Ｎｅ エンジン回転速度 Ｑ０ 目標再循環量 ｈ０ 開弁量 ｈ１ 開弁量 ｈ２ 開弁量 −ａ 設定ずれ幅 ｄＡ 偏差 ｂ 設定ずれ幅10 engine 12 engine body 14 first EGR valve 15 second EGR valve 16 lever opening sensor 17 engine rotation sensor 18 first valve opening sensor 19 second valve opening sensor 20 controller 21 first switching valve 23 second switching valve E exhaust Path I Intake path θ L Lever opening signal Ne Engine speed Q0 Target recirculation amount h0 Valve opening amount h1 Valve opening amount h2 Valve opening amount -a Setting deviation width dA Deviation b Setting deviation width
Claims (1)
気路に戻す第１及び第２排ガス再循環路と、上記第１排
ガス再循環路に設けられ同路の流路断面積を可変とする
第１流量制御弁と、上記第２排ガス再循環路に設けられ
同路の流路断面積を可変とする第２流量制御弁と、上記
ディーゼルエンジンの燃料噴射ポンプのレバー開度信号
を出力するレバー開度センサと、上記ディーゼルエンジ
ンのエンジン回転速度信号を出力するエンジン回転セン
サと、上記第１及び第２流量制御弁の開弁量信号を出力
する第１及び第２弁開度センサと、上記レバー開度信号
及び上記エンジン回転速度信号に基づき上記第１及び第
２流量制御弁の目標再循環量相当の各開弁量をそれぞれ
算出し、同各開弁量に上記第１及び第２流量制御弁を制
御する制御手段とを有し、上記制御手段は上記第１及び
第２流量制御弁の各開弁量と上記目標再循環量相当の開
弁量との各偏差をそれぞれ算出すると共に、それら各偏
差が設定ずれ幅を上回る間は上記第１及び第２流量制御
弁を同時に上記各偏差を打ち消す開弁量に制御し、上記
各偏差が上記設定ずれ幅内にある間は上記第１及び第２
流量制御弁の内の一方のみを上記偏差を打ち消す開弁量
に制御することを特徴とする排ガス再循環装置。1. A first and a second exhaust gas recirculation passage for returning exhaust gas from an exhaust passage of a diesel engine to an intake passage, and a first passage provided in the first exhaust gas recirculation passage and having a variable passage sectional area. A first flow control valve, a second flow control valve that is provided in the second exhaust gas recirculation passage and has a variable flow passage cross-sectional area, and a lever that outputs a lever opening signal of the fuel injection pump of the diesel engine An opening degree sensor, an engine rotation sensor that outputs an engine rotation speed signal of the diesel engine, first and second valve opening degree sensors that output valve opening amount signals of the first and second flow rate control valves, and Based on the lever opening signal and the engine speed signal, the valve opening amounts corresponding to the target recirculation amounts of the first and second flow rate control valves are calculated, and the first and second flow rates are set to the respective valve opening amounts. Control means for controlling the control valve and The control means calculates respective deviations between the valve opening amounts of the first and second flow rate control valves and the valve opening amounts corresponding to the target recirculation amount, and the respective deviations set a deviation range. While exceeding, the first and second flow rate control valves are simultaneously controlled to the valve opening amount that cancels out the respective deviations, and while the respective deviations are within the set deviation width, the first and second deviations are controlled.
An exhaust gas recirculation device, wherein only one of the flow rate control valves is controlled to a valve opening amount that cancels the above deviation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5146461A JPH074321A (en) | 1993-06-17 | 1993-06-17 | Exhaust gas recirculation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5146461A JPH074321A (en) | 1993-06-17 | 1993-06-17 | Exhaust gas recirculation device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH074321A true JPH074321A (en) | 1995-01-10 |
Family
ID=15408166
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5146461A Withdrawn JPH074321A (en) | 1993-06-17 | 1993-06-17 | Exhaust gas recirculation device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH074321A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006097366A1 (en) * | 2005-03-18 | 2006-09-21 | Siemens Vdo Automotive Ag | Method for recirculating a sub-stream of exhaust gas to an internal combustion engine of a motor vehicle |
-
1993
- 1993-06-17 JP JP5146461A patent/JPH074321A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006097366A1 (en) * | 2005-03-18 | 2006-09-21 | Siemens Vdo Automotive Ag | Method for recirculating a sub-stream of exhaust gas to an internal combustion engine of a motor vehicle |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000905 |