JPS6139065Y2 - - Google Patents
Info
- Publication number
- JPS6139065Y2 JPS6139065Y2 JP6143982U JP6143982U JPS6139065Y2 JP S6139065 Y2 JPS6139065 Y2 JP S6139065Y2 JP 6143982 U JP6143982 U JP 6143982U JP 6143982 U JP6143982 U JP 6143982U JP S6139065 Y2 JPS6139065 Y2 JP S6139065Y2
- Authority
- JP
- Japan
- Prior art keywords
- engine
- air
- secondary air
- fuel ratio
- fuel
- 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.)
- Expired
Links
- 239000000446 fuel Substances 0.000 claims description 42
- 239000000203 mixture Substances 0.000 claims description 21
- 239000003054 catalyst Substances 0.000 claims description 19
- 239000007789 gas Substances 0.000 claims description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 10
- 239000001301 oxygen Substances 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 238000002485 combustion reaction Methods 0.000 claims description 7
- 238000010792 warming Methods 0.000 claims description 6
- 238000011144 upstream manufacturing Methods 0.000 claims description 5
- 239000000498 cooling water Substances 0.000 claims description 4
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 238000000746 purification Methods 0.000 claims description 3
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 235000014676 Phragmites communis Nutrition 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 239000002828 fuel tank Substances 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
Landscapes
- Exhaust Gas After Treatment (AREA)
Description
【考案の詳細な説明】
本考案は排気系に三元触媒装置を備えた内燃機
関の排気浄化装置に関する。[Detailed Description of the Invention] The present invention relates to an exhaust gas purification device for an internal combustion engine that includes a three-way catalyst device in the exhaust system.
排気中に含まれるHC,COの酸化と、NOxの還
元を同時に行う三元触媒装置は、混合気の空燃比
が理論空燃比近傍の、極く狭い範囲内にあるとき
のみ有効に働く。 A three-way catalyst device, which simultaneously oxidizes HC and CO contained in exhaust gas and reduces NOx, works effectively only when the air-fuel ratio of the mixture is within an extremely narrow range around the stoichiometric air-fuel ratio.
そのため、三元触媒装置を設置した内燃機関で
は、排気中の酸素濃度を検出しながら混合気が理
論空燃比になるように、燃料供給量をフイードバ
ツク制御していることが多い。 Therefore, in an internal combustion engine equipped with a three-way catalyst device, the amount of fuel supplied is often feedback-controlled so that the air-fuel mixture reaches the stoichiometric air-fuel ratio while detecting the oxygen concentration in the exhaust gas.
ところが、機関暖機時などは円滑な運転を確保
するのに、濃い混合気が必要となるため、このよ
うな運転時には、フイードバツク制御を一時的に
中止し、濃混合気を供給して暖機促進をはかつて
いる。 However, when warming up the engine, a rich air-fuel mixture is required to ensure smooth operation, so during such operations, feedback control is temporarily stopped and a rich air-fuel mixture is supplied to warm up the engine. We are trying to promote this.
ところが、このように濃混合気を供給すると、
排気中に含まれる未燃成分であるHC,COが増加
し、三元触媒装置では酸素不足のために、これら
HC,COを酸化しきれなくなるという現象が生じ
た。 However, when supplying a rich mixture like this,
HC and CO, which are unburned components contained in the exhaust gas, increase, and the three-way catalytic converter is unable to absorb these components due to lack of oxygen.
A phenomenon occurred in which HC and CO could not be fully oxidized.
従来、かかる対策として、第1図に示すような
装置が提案された(実開昭52−160010号)。 Conventionally, as a measure against this problem, a device as shown in FIG. 1 has been proposed (Utility Model Application No. 160010/1983).
1は機関本体、2はエアクリーナ、3は吸気マ
ニホールド、4は吸気絞弁、5は排気マニホール
ドを示し、排気管7には三元触媒装置6が設置さ
れるとともにその上流に酸素センサ12が設けら
れる。 1 is the engine body, 2 is an air cleaner, 3 is an intake manifold, 4 is an intake throttle valve, and 5 is an exhaust manifold. A three-way catalyst device 6 is installed in the exhaust pipe 7, and an oxygen sensor 12 is installed upstream thereof. It will be done.
吸気マニホールド3の各吸気ポート部には燃料
噴射弁13が取付けられ、制御回路(マイクロコ
ンピユータ)14からの駆動パルス信号に応じて
開閉し、燃料タンク(ポンプ)11から送り込ま
れる燃料を吸気ポートに噴射供給する。 A fuel injection valve 13 is attached to each intake port of the intake manifold 3, and opens and closes in response to a drive pulse signal from a control circuit (microcomputer) 14 to direct fuel sent from the fuel tank (pump) 11 to the intake port. Supply injection.
制御回路14には吸入空気量を測定するエアフ
ローメータ15と、機関回転数に対応した信号を
出力する点火コイル19と、機関暖機状態を検出
する冷却水温センサ16と、前述した酸素センサ
12の出力がそれぞれ入力する。 The control circuit 14 includes an air flow meter 15 that measures the amount of intake air, an ignition coil 19 that outputs a signal corresponding to the engine speed, a cooling water temperature sensor 16 that detects the warm-up state of the engine, and the oxygen sensor 12 mentioned above. Output is input respectively.
制御回路14は機関の暖機中は、エアフローメ
ータ15と点火コイル19の出力にもとづき、濃
混合気が得られるように燃料噴射量を演算し、機
関回転に同期して燃料噴射弁13を開閉作動させ
る。 While the engine is warming up, the control circuit 14 calculates the fuel injection amount based on the output of the air flow meter 15 and the ignition coil 19 so as to obtain a rich mixture, and opens and closes the fuel injection valve 13 in synchronization with the engine rotation. Activate.
これに対して機関暖機後は、理論空燃比が得ら
れるように演算した燃料噴射量を、酸素センサ1
2の出力にもとづいて補正し、この補正パルス信
号により燃料噴射弁13を開閉して、混合気を精
度よく理論空燃比にフイードバツク制御し、三元
触媒装置6の働きを最良に保つのである。 On the other hand, after the engine warms up, the fuel injection amount calculated to obtain the stoichiometric air-fuel ratio is
The corrected pulse signal is used to open and close the fuel injection valve 13 to accurately feedback control the air-fuel mixture to the stoichiometric air-fuel ratio, thereby maintaining the three-way catalytic converter 6 at its best.
そして、暖機中の濃混合気により増加した排気
中のHC,COに対処するため、二次空気導入路8
を排気系に設置し、リードバルブ10により排気
脈動を利用して三元触媒装置6の上流に二次空気
を導入するようにしてある。 In order to deal with the increase in HC and CO in the exhaust gas due to the rich mixture during warm-up, the secondary air introduction passage 8
is installed in the exhaust system, and secondary air is introduced upstream of the three-way catalyst device 6 using the exhaust pulsation using the reed valve 10.
二次空気導入路8の入口部には遮断弁9が介装
され、制御回路14からの信号により、冷却水温
が所定値以下の暖機時のみ遮断弁9を開く。 A cutoff valve 9 is interposed at the entrance of the secondary air introduction path 8, and is opened by a signal from the control circuit 14 only during warm-up when the cooling water temperature is below a predetermined value.
このようにして、フイードバツク制御を中止し
て濃混合気を供給する暖機時には、同時に二次空
気を三元触媒装置6の上流に導入するため、三元
触媒装置6を酸化触媒装置として効率よく働かせ
ることができ、HC,COを効果的に酸化除去でき
るのである。 In this way, during warm-up when feedback control is stopped and a rich mixture is supplied, secondary air is simultaneously introduced upstream of the three-way catalyst device 6, so that the three-way catalyst device 6 can be efficiently used as an oxidation catalyst device. HC and CO can be effectively oxidized and removed.
暖機後は遮断弁9が閉じるので、二次空気の供
給は停止し、同時に混合気が理論空燃比にフイー
ドバツク制御され、三元触媒装置6はHC,COの
酸化とNOxの還元を行う。 After warming up, the shutoff valve 9 closes, so the supply of secondary air is stopped, and at the same time, the air-fuel mixture is feedback-controlled to the stoichiometric air-fuel ratio, and the three-way catalyst device 6 oxidizes HC and CO and reduces NOx.
ところが、上記のように暖機中に濃混合気を供
給し、その排気中に二次空気を送り込んでいる場
合、減速時にアフターバーンが起きやすくなると
いう新たな問題を生じた。特に、高中速走行から
の減速時、空吹かし後の絞弁全閉時に起きやすか
つた。 However, when a rich air-fuel mixture is supplied during warm-up and secondary air is sent into the exhaust gas as described above, a new problem arises in that afterburn is more likely to occur during deceleration. This was particularly likely to occur when decelerating from high to medium speeds or when the throttle valve was fully closed after revving.
機関が十分に暖まらないうちに自動車を走らせ
ることはよくあることだが、暖機終了前の走行中
に減速状態に入ると、とくに減速初期には吸気マ
ニホールド内壁等に付着していた燃料が急増する
負圧によつてシリンダ内へ一気に吸い込まれるこ
ともあつて、もともと濃い混合気がなお一層濃く
なり、この濃混合気が完全に燃焼しないで排気ガ
スとして排出する。 It is common for a car to be started before the engine has warmed up sufficiently, but if the vehicle enters a deceleration state while driving before the engine has finished warming up, the amount of fuel adhering to the inner walls of the intake manifold will increase rapidly, especially in the early stages of deceleration. The resulting negative pressure may cause the mixture to be sucked into the cylinder all at once, making the originally rich air-fuel mixture even richer, and the rich air-fuel mixture is not completely combusted and is emitted as exhaust gas.
ここに、二次空気が供給されると、爆発的に燃
焼が行われるのである。このようなアフターバー
ンが度重なると三元触媒装置6が焼損するなど、
触媒の寿命を短かくすることがあつた。 When secondary air is supplied here, explosive combustion occurs. If such afterburn occurs repeatedly, the three-way catalyst device 6 may burn out, etc.
This may shorten the life of the catalyst.
本考案はこのような問題を解決するために、暖
機が終了するまでの間、所定回転数以上からの減
速初期には二次空気の供給を停止させるようにし
たもので、暖機中のアフターバーンを防いで触媒
の耐久性を向上させることを目的とする。 In order to solve this problem, the present invention is designed to stop the supply of secondary air at the beginning of deceleration from a predetermined rotation speed until the end of warm-up. The purpose is to prevent afterburn and improve the durability of the catalyst.
以下、本考案の実施例を第2図にもとづいて説
明するが、第1図と実質的に同一部分には同符号
を用いることにする。 Hereinafter, an embodiment of the present invention will be described based on FIG. 2, and the same reference numerals will be used for substantially the same parts as in FIG. 1.
この実施例は燃料供給装置として、気化器20
を備えており、したがつて制御回路14は通常は
気化器20で生成される混合気の空燃比をフイー
ドバツク制御により、理論空燃比に制御する。 In this embodiment, a carburetor 20 is used as a fuel supply device.
Therefore, the control circuit 14 normally controls the air-fuel ratio of the air-fuel mixture produced by the carburetor 20 to the stoichiometric air-fuel ratio by feedback control.
具体的には燃料通路に接続するエアブリードか
らのエア導入量をオンオフ型電磁弁21で制御す
る。 Specifically, the amount of air introduced from an air bleed connected to the fuel passage is controlled by an on/off type solenoid valve 21.
そして、暖機中はこのエアブリードを全閉する
等により、混合気の空燃比を所定の状態まで濃く
する。 During warm-up, the air-fuel ratio of the air-fuel mixture is enriched to a predetermined state by, for example, fully closing the air bleed.
減速状態を検出するために、吸気絞弁4の全閉
を検出するスロツトルスイツチ22が設けられ、
制御回路14はこのスイツチ22からの信号と、
そのときの機関回転数信号(点火コイル19から
の信号)とから、減速状態を判別する。 In order to detect the deceleration state, a throttle switch 22 is provided to detect when the intake throttle valve 4 is fully closed.
The control circuit 14 receives the signal from this switch 22,
The deceleration state is determined from the engine rotational speed signal (signal from the ignition coil 19) at that time.
そして、減速時には遮断弁9のダイヤフラム室
23に、三方電磁弁24を切り換えて、負圧導入
路25を経由しての吸入負圧を断ち、大気を導入
するようになつている。 During deceleration, the three-way solenoid valve 24 is switched to cut off the suction negative pressure via the negative pressure introduction path 25 and introduce atmospheric air into the diaphragm chamber 23 of the cutoff valve 9.
ダイヤフラム室23に大気を導入すると、スプ
リング26によりダイヤフラム27が押され、遮
断弁9が二次空気の導入を停止するように閉弁す
る。 When atmospheric air is introduced into the diaphragm chamber 23, the diaphragm 27 is pushed by the spring 26, and the shutoff valve 9 is closed to stop introducing secondary air.
なお、遮断弁9とリードバルブ10はエアクリ
ーナ2の内部に設けてある。 Note that the shutoff valve 9 and the reed valve 10 are provided inside the air cleaner 2.
その他の構成は第1図と同様であり、次に作用
について説明すると、機関の暖機時は前述の通
り、空燃比のフイードバツク制御が停止され、濃
混合気が供給されるとともに、遮断弁9が開かれ
て排気中に二次空気が導入される。 The rest of the configuration is the same as that shown in FIG. 1. Next, the operation will be explained. As mentioned above, when the engine is warmed up, the air-fuel ratio feedback control is stopped, a rich mixture is supplied, and the shutoff valve 9 is opened to introduce secondary air into the exhaust.
これにより未燃HC,COは三元触媒装置6を酸
化触媒装置として使用し、HC,COが除去され
る。 As a result, unburned HC and CO are removed using the three-way catalyst device 6 as an oxidation catalyst device.
一方、この暖機時に減速状態に移ると、すなわ
ち絞弁4が全閉で回転数が所定値以上の間は、制
御回路14が三方電磁弁24を切換え大気解放
し、遮断弁9を全閉保持する。 On the other hand, when the system shifts to a deceleration state during this warm-up period, that is, while the throttle valve 4 is fully closed and the rotation speed is above a predetermined value, the control circuit 14 switches the three-way solenoid valve 24 to release it to the atmosphere, and the shutoff valve 9 is fully closed. Hold.
したがつてこの間は排気中に二次空気が導入さ
れず、未燃燃料を含む排気ガスが排出されても、
排気中には酸素がないため一気に爆発的に燃焼す
ることがなくなる。 Therefore, during this period, no secondary air is introduced into the exhaust gas, and even if exhaust gas containing unburned fuel is discharged,
Since there is no oxygen in the exhaust gas, explosive combustion will not occur all at once.
これに対して絞弁4が閉じても機関回転数の低
いアイドリング時などは、アフターバーンの心配
がないため、制御回路14は三方電磁弁24を切
換え、吸気負圧をダイヤフラム室23に導き、遮
断弁9を開いて二次空気を導入する。 On the other hand, even if the throttle valve 4 is closed, there is no risk of afterburn during idling, where the engine speed is low, so the control circuit 14 switches the three-way solenoid valve 24 to guide the intake negative pressure to the diaphragm chamber 23. Open the shutoff valve 9 to introduce secondary air.
暖機後に空燃比のフイードバツク制御が開始さ
れると、制御回路14は遮断弁9を閉じる信号を
出力する。この状態では混合気が理論空燃比にな
つているため、減速初期にも混合気はそれほど濃
くならず、また排気中に含まれる余剰酸素もほと
んどないので、アフターバーンは生じない。本実
施例では燃料供給装置を気化器としたが燃料噴射
弁を使用しても同じ作用が得られる。 When air-fuel ratio feedback control is started after warm-up, the control circuit 14 outputs a signal to close the cutoff valve 9. In this state, the air-fuel mixture is at the stoichiometric air-fuel ratio, so the air-fuel mixture does not become very rich even in the early stages of deceleration, and there is almost no excess oxygen in the exhaust gas, so afterburn does not occur. In this embodiment, a carburetor is used as the fuel supply device, but the same effect can be obtained by using a fuel injection valve.
また、遮断弁9のダイヤフラム室23へ入る吸
入負圧を三方電磁弁24で制御しているが、吸入
負圧を使用せず、遮断弁9を制御回路14からの
信号で作動するオンオフ式電磁弁で直接開閉して
もよいことは云うまでもない。 In addition, the suction negative pressure entering the diaphragm chamber 23 of the shutoff valve 9 is controlled by the three-way solenoid valve 24, but the on-off type solenoid valve 24 does not use suction negative pressure and operates the shutoff valve 9 with a signal from the control circuit 14. Needless to say, it may be opened and closed directly with a valve.
以上のように本考案によれば、空燃比フイード
バツク制御を中止して濃混合気を供給している暖
機中に減速状態に移行したときは、二次空気の供
給を遮断するようにしたので、減速初期や空吹し
直後に起きやすいアフターバーンを防止すること
ができ、三元触媒装置など排気系の耐久性向上が
はかれる。 As described above, according to the present invention, when the air-fuel ratio feedback control is stopped and a rich mixture is being supplied during warm-up and a deceleration state is entered, the supply of secondary air is cut off. It is possible to prevent afterburn, which tends to occur at the beginning of deceleration or immediately after idling, and improve the durability of exhaust systems such as three-way catalytic converters.
第1図は従来装置の概略構成図、第2図は本考
案の概略構成図である。
1……機関本体、3……吸気マニホールド、4
……吸気絞弁、5……排気マニホールド、6……
三元触媒装置、7……排気管、8……二次空気導
入路、9……遮断弁、10……リードバルブ、1
2……酸素センサ、14……制御回路、16……
冷却水温センサ、19……点火コイル、22……
スロツトルスイツチ、24……三方電磁弁。27
……ダイヤフラム。
FIG. 1 is a schematic configuration diagram of a conventional device, and FIG. 2 is a schematic configuration diagram of the present invention. 1...Engine body, 3...Intake manifold, 4
...Intake throttle valve, 5...Exhaust manifold, 6...
Three-way catalyst device, 7...Exhaust pipe, 8...Secondary air introduction path, 9...Shutoff valve, 10...Reed valve, 1
2... Oxygen sensor, 14... Control circuit, 16...
Cooling water temperature sensor, 19...Ignition coil, 22...
Throttle switch, 24...3-way solenoid valve. 27
...Diaphragm.
Claims (1)
この三元触媒装置の上流排気通路に二次空気を導
入する二次空気導入装置と、同じく上流排気の酸
素濃度を検出する酸素センサと、機関の暖機状態
を検出する冷却水温センサとを設け、機関暖機後
は二次空気導入装置の作動を停止して酸素センサ
の出力にもとづいて機関供給混合気を理論空燃比
にフイードバツク制御し、暖機前はこのフイード
バツク制御を解除して理論空燃比よりも濃い空燃
比に制御し、かつ、二次空気導入装置を作動させ
て三元触媒装置を酸化触媒装置として使用した内
燃機関の排気ガス浄化装置において、機関の減速
状態を検出する装置と、所定回転数以上からの減
速初期には暖機前であつても上記二次空気導入装
置の作動を停止する制御装置とを備えたことを特
徴とする内燃機関の排気浄化装置。 A three-way catalyst device installed in the exhaust passage of an internal combustion engine,
A secondary air introduction device that introduces secondary air into the upstream exhaust passage of this three-way catalyst device, an oxygen sensor that also detects the oxygen concentration of the upstream exhaust, and a cooling water temperature sensor that detects the warm-up state of the engine are installed. After warming up the engine, the operation of the secondary air introduction device is stopped and the air-fuel mixture supplied to the engine is feedback-controlled to the stoichiometric air-fuel ratio based on the output of the oxygen sensor. A device for detecting the deceleration state of an engine in an exhaust gas purification device for an internal combustion engine that controls the air-fuel ratio to be richer than the fuel ratio, operates a secondary air introduction device, and uses a three-way catalyst device as an oxidation catalyst device. 1. An exhaust gas purification device for an internal combustion engine, comprising: a control device that stops the operation of the secondary air introduction device even before warming up at an initial stage of deceleration from a predetermined rotation speed or higher.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6143982U JPS58163622U (en) | 1982-04-27 | 1982-04-27 | Internal combustion engine exhaust gas purification device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6143982U JPS58163622U (en) | 1982-04-27 | 1982-04-27 | Internal combustion engine exhaust gas purification device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS58163622U JPS58163622U (en) | 1983-10-31 |
JPS6139065Y2 true JPS6139065Y2 (en) | 1986-11-10 |
Family
ID=30071638
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP6143982U Granted JPS58163622U (en) | 1982-04-27 | 1982-04-27 | Internal combustion engine exhaust gas purification device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58163622U (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2910034B2 (en) * | 1987-09-07 | 1999-06-23 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
JP2022149334A (en) * | 2021-03-25 | 2022-10-06 | ヤンマーホールディングス株式会社 | engine system |
-
1982
- 1982-04-27 JP JP6143982U patent/JPS58163622U/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS58163622U (en) | 1983-10-31 |
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