JPH03124909A - Exhaust gas cleaning device for lean burn engine - Google Patents
Exhaust gas cleaning device for lean burn engineInfo
- Publication number
- JPH03124909A JPH03124909A JP1264138A JP26413889A JPH03124909A JP H03124909 A JPH03124909 A JP H03124909A JP 1264138 A JP1264138 A JP 1264138A JP 26413889 A JP26413889 A JP 26413889A JP H03124909 A JPH03124909 A JP H03124909A
- Authority
- JP
- Japan
- Prior art keywords
- catalytic converter
- nox
- exhaust gas
- lean burn
- engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004140 cleaning Methods 0.000 title abstract 2
- 230000003197 catalytic effect Effects 0.000 claims abstract description 40
- 239000000446 fuel Substances 0.000 claims abstract description 11
- 238000000354 decomposition reaction Methods 0.000 claims description 39
- 238000000746 purification Methods 0.000 claims description 20
- 239000003638 chemical reducing agent Substances 0.000 claims description 15
- 238000001514 detection method Methods 0.000 abstract description 3
- 239000003795 chemical substances by application Substances 0.000 abstract 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 144
- 239000007789 gas Substances 0.000 description 26
- 239000003054 catalyst Substances 0.000 description 21
- 238000000034 method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000010926 purge Methods 0.000 description 4
- 238000006722 reduction reaction Methods 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000002828 fuel tank Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910002090 carbon oxide Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
- F01N3/2033—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using a fuel burner or introducing fuel into exhaust duct
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/03—Adding substances to exhaust gases the substance being hydrocarbons, e.g. engine fuel
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、自動車用のリーンバーンエンジンに用いて好
適のＮ０ｘ（窒素酸化物）分解型の触媒コンバータをそ
なえた排気ガス浄化装置に関し、特に、ＮＯｘ分解時の
還元剤として燃料中のＨＣ（炭化水素）を利用できるよ
うにした、排気ガス浄化装置に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust gas purification device equipped with a NOx (nitrogen oxide) decomposition type catalytic converter suitable for use in lean burn engines for automobiles, and in particular, , relates to an exhaust gas purification device that can utilize HC (hydrocarbons) in fuel as a reducing agent during NOx decomposition.
［従来の技術］
近年、自動車用エンジンをはじめとして、エンジンの排
気ガスの浄化が求められており、この手段として、エン
ジンの排気系に浄化処理用の触媒コンバータをそなえた
ものがある。このような触媒コンバータに内蔵される触
媒としては、三元触媒や酸化触媒や還元触媒があり、還
元触媒の中には、窒素酸化物（以下、ＮＯｘという）を
分解してＮ、、 Ｇｏ、に変換させるＮＯｘ分解型の継
媒がある。[Prior Art] In recent years, there has been a demand for purification of exhaust gas from engines such as automobile engines, and as a means for this purpose, there is a method in which the exhaust system of the engine is provided with a catalytic converter for purification processing. Catalysts built into such catalytic converters include three-way catalysts, oxidation catalysts, and reduction catalysts. Among the reduction catalysts, nitrogen oxides (hereinafter referred to as NOx) are decomposed into N, Go, There is a NOx decomposition type transfer medium that converts NOx into NOx.
ところで、Ａ／Ｆ （火祭の空燃比）が理論空燃比より
も大きい（リーン）時には、酸素濃度が高いので、酸化
反応が優先されるようになって、三元触媒や酸化触媒で
は、Ｎ Ｏｘの浄化（還元反応）は不可能である。By the way, when the A/F (fire air fuel ratio) is higher than the stoichiometric air fuel ratio (lean), the oxygen concentration is high, so the oxidation reaction takes priority, and the three-way catalyst and oxidation catalyst reduce NOx. It is impossible to purify (reduction reaction).
しかし、Ｃｕ−ゼオライト等の特殊な触媒を用いると、
リーン条件下でも。However, when special catalysts such as Cu-zeolite are used,
Even under lean conditions.
２ＮＯ４−−）Ｎ、＋Ｏ□
のＮｏ分解反応によりＮＯｘの浄化が可能とされている
。It is said that NOx can be purified by the No decomposition reaction of 2NO4--)N, +O□.
そこで、リーンバーンエンジンの排気ガス処理にはＮＯ
ｘ分解型）！［が適していると思ねれる。Therefore, for exhaust gas treatment of lean burn engines, NO
x decomposition type)! [does not seem appropriate.
［発明が解決しようとする課題］
ところで、上述のＮＯｘ分解型触媒は、一般に、炭化水
素（以下、ＨＣという）や−酸化炭素（以下、ＣＯとい
う）等を還元剤として用いることにより、その浄化効率
を高めることが可能であるといわれている。[Problems to be Solved by the Invention] By the way, the above-mentioned NOx decomposition catalyst generally has a problem in its purification by using hydrocarbons (hereinafter referred to as HC), -carbon oxides (hereinafter referred to as CO), etc. as reducing agents. It is said that it is possible to increase efficiency.
しかしながら、上述のリーンバーンエンジンでは、還元
剤としてのＨＣやＣＯが不足しがちとなって、ＮＯｘ分
解型触媒から０２の離脱が促進させず十分なＮＯｘ浄化
効率が得られないという問題点がある。However, in the above-mentioned lean burn engine, there is a problem that HC and CO as reducing agents tend to be insufficient, and the separation of 02 from the NOx decomposition catalyst is not promoted and sufficient NOx purification efficiency cannot be obtained. .
本発明は、このような課題に鑑みて案出されたもので、
リーンバーンエンジンにおいて高いＮ。The present invention was devised in view of such problems, and
High N in lean burn engines.
Ｘ浄化効率が得られるようにした、リーンバーンエンジ
ンの排気ガス浄化装置を提供することを目的とする。It is an object of the present invention to provide an exhaust gas purification device for a lean burn engine that can obtain X purification efficiency.
［課題を解決するための手段］
このため、本発明のリーンバーンエンジンの排気ガス浄
化装置は、リーンバーンエンジンの排気系において、排
気ガスを浄化処理するＮＯｘ分解型の触媒コンバータを
そなえ、燃料中のＨＣをＮＯｘ分解時の還元剤として該
触媒コンバータへ導入するＨ Ｃ導入手段が設けられて
いることを特徴としている。[Means for Solving the Problems] Therefore, the exhaust gas purification device for a lean burn engine of the present invention is provided with a NOx decomposition type catalytic converter for purifying exhaust gas in the exhaust system of a lean burn engine. The present invention is characterized in that it is provided with an HC introducing means for introducing HC into the catalytic converter as a reducing agent during NOx decomposition.
［作 用］
上述の本発明のリーンバーンエンジンの排気ガス浄化装
置では、ＨＣＣ大人手段、燃料中のＦ（ＣをＮＯｘ分解
時の還元剤として触媒コンバータへ導入し、触媒コンバ
ータでは還元剤としてのＨＣによってＮＯｘの分解が促
進されて、排気ガス中のＮＯｘが効率よく浄化される。[Function] In the lean burn engine exhaust gas purification device of the present invention described above, HCC adult means and F(C) in the fuel are introduced into the catalytic converter as a reducing agent during NOx decomposition, and in the catalytic converter, the F(C) is introduced as a reducing agent. The decomposition of NOx is promoted by HC, and NOx in the exhaust gas is efficiently purified.
［実施例コ
以下、図面により本発明の一実施例としてのリーンバー
ンエンジンの排気ガス浄化装置について説明すると、第
１図はその模式的な構成図、第２図はその動作を説明す
るフローチャート、第３図はその効果を示すグラフ、第
４図はその変形例を示す模式的な構成図であり、第４図
中、第１図と同符号は同様な部分を示している。[Embodiment] An exhaust gas purification device for a lean burn engine as an embodiment of the present invention will be explained below with reference to the drawings. Fig. 1 is a schematic configuration diagram thereof, Fig. 2 is a flowchart explaining its operation, FIG. 3 is a graph showing the effect thereof, and FIG. 4 is a schematic configuration diagram showing a modification thereof. In FIG. 4, the same reference numerals as in FIG. 1 indicate the same parts.
第１図において、１はリーンバーンエンジンであり、こ
のリーンバーンエンジン１は、実際の空燃比（Ａ／Ｆ）
が理論空燃比よりも大きいリーン状態で燃焼するリーン
バーン運転領域を有する。In FIG. 1, 1 is a lean burn engine, and this lean burn engine 1 has an actual air-fuel ratio (A/F).
has a lean-burn operation region where the fuel burns in a lean state that is greater than the stoichiometric air-fuel ratio.
１ａはエンジン１の排気通路である。1a is an exhaust passage of the engine 1.
２は排気通路１ａに設けられたＮＯｘ分解型触媒コンバ
ータであり、このＮＯｘ分解型触媒コンバータ２は、還
元触媒の一種であって、ＮＯｘを分解してＮ２．ＣＯ２
に変換させる。2 is a NOx decomposition type catalytic converter provided in the exhaust passage 1a, and this NOx decomposition type catalytic converter 2 is a type of reduction catalyst, and decomposes NOx to produce N2. CO2
Convert it to
３はキャニスタであり、このキャニスタ３はに、燃料タ
ンク８からの蒸発燃料が蓄えられる。3 is a canister, and evaporated fuel from the fuel tank 8 is stored in this canister 3.
４は排気通路１ａのＮＯｘ分解型触媒コンバータ２の上
流側に設けられた三元触媒であり、この三元触媒４は、
ＨＣ，ＣＯ，ＮＯｘの３成分を同時に浄化できる。4 is a three-way catalyst provided upstream of the NOx decomposition type catalytic converter 2 in the exhaust passage 1a, and this three-way catalyst 4 is
Three components, HC, CO, and NOx, can be purified at the same time.
５はキャニスタ３から排気通路のＮＯｘ分解型触媒コン
バータ２よりも上流側に亘って設けられた還元剤通路で
あり、キャニスタ３内に蓄えられた還元剤としてのＨＣ
はこの還元剤通路５を通じて排気通路１ａからＮＯｘ分
解型触媒コンバータ２内へ導入させる。Reference numeral 5 denotes a reducing agent passage provided from the canister 3 to the upstream side of the NOx decomposition type catalytic converter 2 in the exhaust passage.
is introduced into the NOx decomposition type catalytic converter 2 from the exhaust passage 1a through the reducing agent passage 5.
なお、この例ではＨＣを有効にＮＯｘ分解型触媒コンバ
ータ２内へ供給するために、還元剤通路５の出口を、三
元触媒４の下流側に設けているが、三元触媒４の上流側
に設けることも考えられる。In this example, in order to effectively supply HC into the NOx decomposition type catalytic converter 2, the outlet of the reducing agent passage 5 is provided on the downstream side of the three-way catalyst 4; It is also conceivable to provide a
また、このキャニスタ３側からＮ Ｏｘ分解型触媒コン
バータ２側へのＨＣの流れ（矢印ａ参照）は、排気通路
１ａにおける排気脈流（矢印す参照）を即動源として行
なわれるようになっている。Furthermore, the flow of HC from the canister 3 side to the NOx decomposition type catalytic converter 2 side (see arrow a) is carried out using the exhaust pulsating flow (see arrow mark) in the exhaust passage 1a as an immediate source. There is.
５ａは還元剤通路５に設けられたチエツクバルブであり
、このチエツクバルブ５ａは、ＮＯｘ分解型触媒コンバ
ータ２側からキャニスタ３側へのＨＣの逆流を防止する
。5a is a check valve provided in the reducing agent passage 5, and this check valve 5a prevents HC from flowing back from the NOx decomposition type catalytic converter 2 side to the canister 3 side.
６はソレノイドバルブであり、ソレノイドバルブ６は、
還元剤通路５の途中に設けられており、制御信号に応じ
て適宜開閉する。6 is a solenoid valve, and the solenoid valve 6 is
It is provided in the middle of the reducing agent passage 5 and opens and closes as appropriate in response to a control signal.
７はＨＣ計測器であり、このＨＣ計測器７は。7 is an HC measuring instrument; this HC measuring instrument 7 is.
Ｎ Ｏｘ分解型触媒コンバータ２の下流に設けられ、排
気ガス中のＨＣの量又は濃度を検出する。It is provided downstream of the NOx decomposition type catalytic converter 2 and detects the amount or concentration of HC in the exhaust gas.
９はエンジンコントロールユニット（ＥＣＵ）であり、
このＥＣＵ９は、ＨＣ計測器７がらの検出信号に基づい
てソレノイドバルブ６の開閉を促■御する。9 is an engine control unit (ECU),
This ECU 9 prompts and controls the opening and closing of the solenoid valve 6 based on a detection signal from the HC measuring device 7.
つまり、ＮＯｘ分解型触媒コンバータ２を通過した排気
ガス中にＨＣが基準値以上含まれていれば、ＮＯｘ分解
型触媒コンバータ２へのＨＣの供給が過多であるとして
ソレノイドバルブ６を閉鎖するように制御して、キャニ
スタ３からＮＯｘ分解型触媒コンバータ２へＨＣをパー
ジ導入を停止する。一方、ＨＣが基準値以上含まれてい
なければ、ソレノイドバルブ６を開放するように制御し
てＮＯｘ分解型触媒コンバータ２へ触媒としてのＨＣを
パージ通人する。In other words, if the exhaust gas that has passed through the NOx decomposition type catalytic converter 2 contains more than the standard value of HC, the solenoid valve 6 is closed because the supply of HC to the NOx decomposition type catalytic converter 2 is excessive. Purge introduction of HC from the canister 3 to the NOx decomposition type catalytic converter 2 is stopped. On the other hand, if HC is not contained above the reference value, the solenoid valve 6 is controlled to open to purge the NOx decomposition type catalytic converter 2 with HC as a catalyst.
なお、排気ガス中にＨＣが含まれている否かについては
、基準値を設けずに、排気ガス中にＨＣが検出されたか
排気ガス中にＨＣが検出されないかで判断してもよい。Note that whether or not HC is contained in the exhaust gas may be determined based on whether HC is detected in the exhaust gas or not, without setting a reference value.
本発明の一実施例としてのリーンバーンエンジンの排気
ガス浄化装置は、上述のごとく構成されており、エンジ
ン１からは排出された排気ガス中のＨＣ，Ｃ○について
は三元触媒４で浄化され、ＮＯｘについては主としてＮ
Ｏｘ分解型触媒コンバータ２で浄化される。この際、本
排気ガス浄化装置では、ＥＣＵ９を通じて、第２図のフ
ローチャートに示すような制御が行なわれる。The exhaust gas purification device for a lean burn engine as an embodiment of the present invention is configured as described above, and HC and C○ in the exhaust gas discharged from the engine 1 are purified by the three-way catalyst 4. , for NOx, mainly N
It is purified by the Ox decomposition type catalytic converter 2. At this time, in this exhaust gas purification device, control as shown in the flowchart of FIG. 2 is performed through the ECU 9.
つまり、エンジンがスタートされる（ステップＳ１参照
）と、ステップＳ２で、エンジン１がリーンバーン運転
領域にあるか否かを判断する。That is, when the engine is started (see step S1), it is determined in step S2 whether or not the engine 1 is in the lean burn operation region.
リーンバーン運転領域でなければ、ステップＳ６へ進ん
で、ソレノイドバルブ６を閉鎖するように制御してキャ
ニスタ３からＮＯｘ分解型触媒コンバータ２へのＨＣの
パージ導入を停止する。If it is not in the lean burn operation region, the process proceeds to step S6, where the solenoid valve 6 is controlled to be closed and the purge introduction of HC from the canister 3 to the NOx decomposition type catalytic converter 2 is stopped.
リーンバーン運転領域であれば、ステップｓ２からステ
ップＳ３へ進んで、ＨＣ計測器７の検出信号に基づいて
ＮＯｘ分解型触媒コンバータ２を通過した排気ガス中に
ＨＣが基準値以上含まれているか否か判断する。If it is in the lean burn operation region, the process proceeds from step s2 to step S3, where it is determined whether or not the exhaust gas that has passed through the NOx decomposition type catalytic converter 2 contains more than a reference value of HC based on the detection signal of the HC measuring device 7. to judge.
排気ガス中にＨＣが基準値以上含まれていれば、上述の
ステップＳ６へ進み、ＮＯｘ分解型触媒コンバータ２へ
のＨＣのパージ導入を停止する。If the exhaust gas contains more than the reference value of HC, the process proceeds to step S6 described above, and the purge introduction of HC to the NOx decomposition type catalytic converter 2 is stopped.
一方、排気ガス中にＨＣが基準値以上含ま九てぃなけれ
ば、ステップＳ３からステップＳ４へ進み、ＮＯｘ分解
型触媒コンバータ２へＨＣをパージ導入する。On the other hand, if the exhaust gas does not contain more than the reference value of HC, the process proceeds from step S3 to step S4, and HC is purged into the NOx decomposition type catalytic converter 2.
これによって、Ｎ Ｏｘ分解型触媒コンバータ２では、
ＨＣを還元剤として、排気ガス中のＮＯｘを確実に分解
できるようになる。As a result, in the NOx decomposition type catalytic converter 2,
Using HC as a reducing agent, NOx in exhaust gas can be reliably decomposed.
このような制御は、ステップＳ５に示すように、エンジ
ンが停止されるまで繰り返し行なわれる。Such control is repeated until the engine is stopped, as shown in step S5.
この結果、ＮＯｘの浄化効率が大幅に高められ、例えば
ＮＯｘの浄化率の特性は、第３図に示すように向上する
ものと考えられる。As a result, it is thought that the NOx purification efficiency is greatly increased, and the characteristics of the NOx purification rate, for example, are improved as shown in FIG. 3.
なお、この第３図では、横軸にＡ／Ｆの値、縦軸にＮＯ
ｘの浄化率がとられており、特性線ａは三元触媒の特性
、特性線すはＨＣを還元剤として供給されないＮＯｘ分
解型触媒コンバータの特性、特性線ＣはＨＣを還元剤と
して供給される本発明のＮＯｘ分解型触媒コンバータの
特性をそれぞれ示している。In addition, in this Figure 3, the horizontal axis shows the A/F value, and the vertical axis shows the NO.
The purification rate of The characteristics of the NOx decomposition type catalytic converter of the present invention are shown respectively.
ところで、上述の実施例では、三元触媒４をＮＯｘ分解
型触媒コンバータ２の上流側に設けているが、第４図に
示すように、三元触媒４をＮＯｘ分解型触媒コンバータ
２の下流側に設けるようにしてもよい。この場合、ＮＯ
ｘＯｘ分解型触媒コンパ−９過直後の排気ガス中のＨＣ
を検出できるように、ＨＣ計測器７を、ＮＯｘ分解型触
媒コンバータ２の下流側で三元触媒４よりも上流側に設
けるようにするのが好ましい。Incidentally, in the above embodiment, the three-way catalyst 4 is provided upstream of the NOx decomposition type catalytic converter 2, but as shown in FIG. It may also be provided. In this case, NO
HC in exhaust gas immediately after passing through xOx decomposition type catalyst comparator 9
It is preferable to provide the HC measuring device 7 downstream of the NOx decomposition type catalytic converter 2 and upstream of the three-way catalyst 4 so as to be able to detect this.
また、リーンバーンエンジンの場合、排気ガス中のＨＣ
，Ｇｏの量が比較的値かなものになるので、三元触媒４
を省略できる場合もある。In addition, in the case of a lean burn engine, HC in the exhaust gas
, Go has a relatively small amount, so the three-way catalyst 4
may be omitted in some cases.
［発明の効果］
以上詳述したように、本発明のリーンバーンエンジンの
排気ガス浄化装置によれば、リーンバーンエンジンの排
気系において、排気ガスを浄化処理するＮＯｘ分解型の
触媒コンバータをそなえ、燃料中のＨＣをＮＯｘ分解時
の還元剤として該触媒コンバータへ導入するＨＣ導入手
段が設けられるという簡素な構成により、リーンバーン
エンジンにおいて高いＮＯｘ浄化効率が得られるように
なる効果がある。[Effects of the Invention] As detailed above, according to the exhaust gas purification device for a lean burn engine of the present invention, the exhaust system of a lean burn engine is provided with a NOx decomposition type catalytic converter for purifying exhaust gas, A simple configuration in which a HC introducing means is provided for introducing HC in the fuel into the catalytic converter as a reducing agent during NOx decomposition has the effect that high NOx purification efficiency can be obtained in a lean burn engine.
第１〜４図は本発明の一実施例としてのリーンバーンエ
ンジンの排気ガス浄化装置を示すもので、第１図はその
模式的な構成図、第２図はその動作を説明するフローチ
ャート、第３図はその効果を示すグラフ、第４図はその
変形例を示す模式的な構成図である。
１・・−リーンバーンエンジン、１ａ・−排気通路、２
−Ｎ Ｏｘ分解型触媒コンバータ、３・−キャニスタ、
４−三元触媒、５−還元剤通路、５ａ−チエツクバルブ
、６−ソレツイドバルブ、７・−ＨＣ計測器、８．−燃
料タンク、９・−・エンジンコントロールユニット（Ｅ
ＣＵ）。1 to 4 show an exhaust gas purification device for a lean burn engine as an embodiment of the present invention, in which FIG. 1 is a schematic configuration diagram thereof, FIG. 2 is a flowchart explaining its operation, and FIG. FIG. 3 is a graph showing the effect thereof, and FIG. 4 is a schematic configuration diagram showing a modification thereof. 1.-Lean burn engine, 1a.-Exhaust passage, 2
-NOx decomposition type catalytic converter, 3-canister,
4-three-way catalyst, 5-reducing agent passage, 5a-check valve, 6-solet valve, 7.-HC measuring instrument, 8. -Fuel tank, 9--Engine control unit (E
CU).
Claims (1)
化処理するＮＯｘ分解型の触媒コンバータをそなえ、燃
料中のＨＣをＮＯｘ分解時の還元剤として該触媒コンバ
ータへ導入するＨＣ導入手段が設けられていることを特
徴とする、リーンバーンエンジンの排気ガス浄化装置。The exhaust system of a lean burn engine is equipped with a NOx decomposition type catalytic converter that purifies exhaust gas, and is provided with HC introduction means for introducing HC in the fuel into the catalytic converter as a reducing agent during NOx decomposition. An exhaust gas purification device for lean burn engines featuring:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1264138A JPH03124909A (en) | 1989-10-11 | 1989-10-11 | Exhaust gas cleaning device for lean burn engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1264138A JPH03124909A (en) | 1989-10-11 | 1989-10-11 | Exhaust gas cleaning device for lean burn engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03124909A true JPH03124909A (en) | 1991-05-28 |
Family
ID=17398987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1264138A Pending JPH03124909A (en) | 1989-10-11 | 1989-10-11 | Exhaust gas cleaning device for lean burn engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03124909A (en) |
Cited By (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993008383A1 (en) * | 1991-10-14 | 1993-04-29 | Toyota Jidosha Kabushiki Kaisha | Exhaust and purification device for internal combustion engine |
| WO1993025806A1 (en) * | 1992-06-12 | 1993-12-23 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| WO1994012778A1 (en) * | 1992-12-03 | 1994-06-09 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning apparatus for internal combustion engines |
| WO1994017291A1 (en) * | 1993-01-19 | 1994-08-04 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning device for an internal combustion engine |
| US5423181A (en) * | 1992-09-02 | 1995-06-13 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purification device of an engine |
| US5473887A (en) * | 1991-10-03 | 1995-12-12 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| WO1996022457A1 (en) * | 1995-01-20 | 1996-07-25 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning method for internal combustion engine |
| EP0758713A1 (en) * | 1995-08-14 | 1997-02-19 | Toyota Jidosha Kabushiki Kaisha | A method for purifying exhaust gas of a diesel engine |
| US5690072A (en) * | 1996-12-13 | 1997-11-25 | Ford Global Technologies, Inc. | Method and system for determining and controlling a/f ratio in lean engines |
| US5720260A (en) * | 1996-12-13 | 1998-02-24 | Ford Global Technologies, Inc. | Method and system for controlling combustion stability for lean-burn engines |
| US5755202A (en) * | 1996-10-25 | 1998-05-26 | Ford Global Technologies, Inc. | Method of reducing feed gas emissions in an internal combustion engine |
| US5775099A (en) * | 1994-04-12 | 1998-07-07 | Toyota Jidosha Kabushiki Kaisha | Method of purifying the exhaust of an internal combustion engine |
| US5778666A (en) * | 1996-04-26 | 1998-07-14 | Ford Global Technologies, Inc. | Method and apparatus for improving engine fuel economy |
| US5832722A (en) * | 1997-03-31 | 1998-11-10 | Ford Global Technologies, Inc. | Method and apparatus for maintaining catalyst efficiency of a NOx trap |
| EP0881367A1 (en) * | 1997-05-30 | 1998-12-02 | Volkswagen Aktiengesellschaft | Catalytic system for removing NOx from diesel engine exhaust gas |
| US5865026A (en) * | 1997-01-21 | 1999-02-02 | Ford Global Technologies, Inc. | System and method for monitoring a catalytic converter using adaptable indicator threshold |
| JPH1162563A (en) * | 1997-08-25 | 1999-03-05 | Toyota Motor Corp | Exhaust emission control device of internal combustion engine |
| US5915359A (en) * | 1996-12-13 | 1999-06-29 | Ford Global Technologies, Inc. | Method and system for determining and controlling A/F ratio during cold start engine operation |
| US5953905A (en) * | 1997-01-17 | 1999-09-21 | Ford Global Technologies, Inc. | System and method for monitoring a catalytic converter |
| US5974785A (en) * | 1997-01-16 | 1999-11-02 | Ford Global Technologies, Inc. | Closed loop bias air/fuel ratio offset to enhance catalytic converter efficiency |
| US5974786A (en) * | 1997-01-21 | 1999-11-02 | Ford Global Technologies, Inc. | Adaptive time window to synchronize pre- and post-catalyst oxygen sensor switch counters |
| US6161378A (en) * | 1996-06-10 | 2000-12-19 | Hitachi, Ltd. | Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas internal combustion engine |
| US6596247B1 (en) | 1996-10-25 | 2003-07-22 | Hitachi, Ltd. | Method for purifying exhaust gas from internal combustion engines |
-
1989
- 1989-10-11 JP JP1264138A patent/JPH03124909A/en active Pending
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|---|---|---|---|---|
| US5473887A (en) * | 1991-10-03 | 1995-12-12 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| WO1993008383A1 (en) * | 1991-10-14 | 1993-04-29 | Toyota Jidosha Kabushiki Kaisha | Exhaust and purification device for internal combustion engine |
| US5471836A (en) * | 1991-10-14 | 1995-12-05 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| WO1993025806A1 (en) * | 1992-06-12 | 1993-12-23 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| US5437153A (en) * | 1992-06-12 | 1995-08-01 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| US5423181A (en) * | 1992-09-02 | 1995-06-13 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purification device of an engine |
| US5473890A (en) * | 1992-12-03 | 1995-12-12 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| WO1994012778A1 (en) * | 1992-12-03 | 1994-06-09 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning apparatus for internal combustion engines |
| US5483795A (en) * | 1993-01-19 | 1996-01-16 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| EP0636770A1 (en) * | 1993-01-19 | 1995-02-01 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning device for an internal combustion engine |
| WO1994017291A1 (en) * | 1993-01-19 | 1994-08-04 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning device for an internal combustion engine |
| EP0636770A4 (en) * | 1993-01-19 | 1998-08-19 | Toyota Motor Co Ltd | Exhaust gas cleaning device for an internal combustion engine. |
| US5775099A (en) * | 1994-04-12 | 1998-07-07 | Toyota Jidosha Kabushiki Kaisha | Method of purifying the exhaust of an internal combustion engine |
| WO1996022457A1 (en) * | 1995-01-20 | 1996-07-25 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning method for internal combustion engine |
| EP0758713A1 (en) * | 1995-08-14 | 1997-02-19 | Toyota Jidosha Kabushiki Kaisha | A method for purifying exhaust gas of a diesel engine |
| US5746989A (en) * | 1995-08-14 | 1998-05-05 | Toyota Jidosha Kabushiki Kaisha | Method for purifying exhaust gas of a diesel engine |
| US5778666A (en) * | 1996-04-26 | 1998-07-14 | Ford Global Technologies, Inc. | Method and apparatus for improving engine fuel economy |
| US6161378A (en) * | 1996-06-10 | 2000-12-19 | Hitachi, Ltd. | Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas internal combustion engine |
| US7093432B2 (en) | 1996-06-10 | 2006-08-22 | Hitachi, Ltd. | Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas of internal combustion engine |
| US6397582B1 (en) | 1996-06-10 | 2002-06-04 | Hitachi, Ltd. | Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas of internal combustion engine |
| US5755202A (en) * | 1996-10-25 | 1998-05-26 | Ford Global Technologies, Inc. | Method of reducing feed gas emissions in an internal combustion engine |
| US6596247B1 (en) | 1996-10-25 | 2003-07-22 | Hitachi, Ltd. | Method for purifying exhaust gas from internal combustion engines |
| US5690072A (en) * | 1996-12-13 | 1997-11-25 | Ford Global Technologies, Inc. | Method and system for determining and controlling a/f ratio in lean engines |
| US5915359A (en) * | 1996-12-13 | 1999-06-29 | Ford Global Technologies, Inc. | Method and system for determining and controlling A/F ratio during cold start engine operation |
| US5720260A (en) * | 1996-12-13 | 1998-02-24 | Ford Global Technologies, Inc. | Method and system for controlling combustion stability for lean-burn engines |
| US5974785A (en) * | 1997-01-16 | 1999-11-02 | Ford Global Technologies, Inc. | Closed loop bias air/fuel ratio offset to enhance catalytic converter efficiency |
| US6112518A (en) * | 1997-01-17 | 2000-09-05 | Ford Global Technologies, Inc. | System and method for monitoring a catalytic converter |
| US5953905A (en) * | 1997-01-17 | 1999-09-21 | Ford Global Technologies, Inc. | System and method for monitoring a catalytic converter |
| US5974786A (en) * | 1997-01-21 | 1999-11-02 | Ford Global Technologies, Inc. | Adaptive time window to synchronize pre- and post-catalyst oxygen sensor switch counters |
| US6018944A (en) * | 1997-01-21 | 2000-02-01 | Ford Global Technologies, Inc. | System and method for monitoring a catalytic converter using adaptable indicator threshold |
| US5865026A (en) * | 1997-01-21 | 1999-02-02 | Ford Global Technologies, Inc. | System and method for monitoring a catalytic converter using adaptable indicator threshold |
| US5832722A (en) * | 1997-03-31 | 1998-11-10 | Ford Global Technologies, Inc. | Method and apparatus for maintaining catalyst efficiency of a NOx trap |
| EP0881367A1 (en) * | 1997-05-30 | 1998-12-02 | Volkswagen Aktiengesellschaft | Catalytic system for removing NOx from diesel engine exhaust gas |
| JPH1162563A (en) * | 1997-08-25 | 1999-03-05 | Toyota Motor Corp | Exhaust emission control device of internal combustion engine |
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