JPS588244A - Suction system air-fuel ratio controller for catalytic device - Google Patents
Suction system air-fuel ratio controller for catalytic deviceInfo
- Publication number
- JPS588244A JPS588244A JP10569881A JP10569881A JPS588244A JP S588244 A JPS588244 A JP S588244A JP 10569881 A JP10569881 A JP 10569881A JP 10569881 A JP10569881 A JP 10569881A JP S588244 A JPS588244 A JP S588244A
- Authority
- JP
- Japan
- Prior art keywords
- air
- fuel ratio
- passage
- intake
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/0015—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for using exhaust gas sensors
- F02D35/0046—Controlling fuel supply
- F02D35/0053—Controlling fuel supply by means of a carburettor
- F02D35/0061—Controlling the emulsifying air only
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Description
【発明の詳細な説明】
この発明は、燃焼室前の吸気系に導入する2次空気量を
変化させて、空燃比を理論空燃比を挾んでその前後に強
制的に変動させた触媒装置の吸気系空燃比制御装置に関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention provides a catalyst device that forcibly changes the air-fuel ratio around the stoichiometric air-fuel ratio by changing the amount of secondary air introduced into the intake system in front of the combustion chamber. The present invention relates to an intake system air-fuel ratio control device.
触媒装置例えば三元触媒装置を有効に作用させるために
は、その装置に導入される排気ガスの成分、特に酸素濃
度を非常に精度良く制御しなければならない。そこで三
元触媒装置を用いる場合には2次空気の制御を厳密に行
い、第1図に示す如く、空燃比をウィンドウ内に保つ必
要がある。なおこのウィンドウは理論空燃比(化学量論
比)145十0.1〜±0.15程度の狭いものである
。このため。In order for a catalyst device, such as a three-way catalyst device, to function effectively, the components of the exhaust gas introduced into the device, particularly the oxygen concentration, must be controlled with great precision. Therefore, when using a three-way catalyst device, it is necessary to strictly control the secondary air to maintain the air-fuel ratio within a window as shown in FIG. Note that this window is narrow, ranging from stoichiometric air-fuel ratio (stoichiometric ratio) of 1450.1 to ±0.15. For this reason.
02センサが使用され、いわゆる空燃比フィードバック
システムが必要となる。02 sensors are used and a so-called air/fuel ratio feedback system is required.
しかし上記従来のシステムは制御方法が極めて複雑であ
シ、その結果制御装置も複雑となり、高価でしかも故障
が多いという欠点があった。またフィードバック制#に
はシステムの時間遅れが存在するため、この欠点を除く
べく速いサイクルの制御を行うと、空燃比の振幅が大き
くな92機関がハンチングを起したり、三元触媒の劣化
を来たすという不都合もある。However, the conventional system described above has the disadvantages that the control method is extremely complicated, and as a result, the control device is also complicated, expensive, and frequently malfunctions. In addition, since there is a time delay in the system in the feedback system #, if a fast cycle control is performed to eliminate this drawback, the 92 engine with a large amplitude of air-fuel ratio may cause hunting or the three-way catalyst may deteriorate. There is also the inconvenience of coming.
そこでこの発明の目的は、極めて簡単な制御装置でNO
xの浄化を行い触媒の耐久性をも向上させ2機関のハン
チングを誘発せず、燃費改善に寄与し得る触媒装置の吸
気系空燃比制御装置を実現するにある。Therefore, the purpose of this invention is to achieve NO.
To realize an intake system air-fuel ratio control device for a catalyst device which can purify x, improve the durability of the catalyst, do not induce hunting in two engines, and contribute to improving fuel efficiency.
以下図面に基づ“てこの発明の詳細な説明す2る。この
発明の理解を容易にするために、まず第7図のグラフに
ついて説明する。このグラフは縦軸に浄化率<’s>
、横軸に空燃比をとシ、理論空燃比を挾むような空燃比
の周期的な変動、つま9リーン(希薄)とリッチ(過濃
)への強制変動によって、浄化率がどのように変化する
かを実験した結果を示すものである。なおこの周期は例
えば0.1〜2秒で空燃比−±0.2〜±1程度である
。そしてこの第1図のグラフによると、全体的に浄化率
は少々落ちるが、3本のグラフCo、HC,NOXの全
てが肩をなだらかにし、更に裾を広げる特性を示すこと
が理解できる。つまりウィンドウが定常運転下に比べ幾
分広がるものである。これは触媒の酸素吸着(オキシゲ
ンストレージ)によるものと考えられる。そしてこのよ
うに空燃比を変動させると、リーン域においてNO!浄
化率の向上という副次的効果をも得る。A detailed explanation of the present invention will be given below based on the drawings.In order to make the invention easier to understand, the graph of FIG. 7 will be explained first.
The horizontal axis shows the air-fuel ratio, and shows how the purification rate changes due to periodic fluctuations in the air-fuel ratio that fall outside the stoichiometric air-fuel ratio, and forced fluctuations between lean and rich. This shows the results of an experiment to determine whether Note that this period is, for example, 0.1 to 2 seconds and the air-fuel ratio is approximately -±0.2 to ±1. According to the graph in FIG. 1, it can be seen that although the overall purification rate is a little lower, all three graphs for Co, HC, and NOX exhibit characteristics with gentler shoulders and wider tails. In other words, the window is somewhat wider than under normal operation. This is thought to be due to oxygen adsorption (oxygen storage) of the catalyst. And by varying the air-fuel ratio in this way, NO! in the lean range! It also has the secondary effect of improving the purification rate.
この性質に着目し、第3図の如く、制御装置を構成する
。すなわち、2はエヤクリーナ、4は気化器、6は吸気
通蕗、8は内燃機関、10は排気通路モして12は三元
触媒装置である。。前記吸気通路6や気化器4等の吸気
系には2次空気通路14を連通させ、該2次空気通路1
4の始端は好ましくは前記エヤクリーナ2に連通させる
。そしてこの2次空気通路14途中には後述する電磁弁
等からなる空燃比を変動させるための空燃比制御手段1
6を介在させる。そしてこの制御手段16により内燃機
関8に投入する空燃比、すなわち三元触媒装置112人
口の空燃比を理論空燃比を挾んでその前後に変動させる
のである。なおこの制御手段16の作動は次の如く種々
の制御態様にすることができる。つまり。Focusing on this property, a control device is constructed as shown in FIG. That is, 2 is an air cleaner, 4 is a carburetor, 6 is an intake vent, 8 is an internal combustion engine, 10 is an exhaust passage, and 12 is a three-way catalyst device. . A secondary air passage 14 is communicated with the intake system such as the intake passage 6 and the carburetor 4.
The starting end of 4 is preferably communicated with the air cleaner 2. In the middle of this secondary air passage 14, there is an air-fuel ratio control means 1 for varying the air-fuel ratio, which includes a solenoid valve, etc., which will be described later.
6 to intervene. The control means 16 changes the air-fuel ratio input to the internal combustion engine 8, that is, the air-fuel ratio of the three-way catalyst device 112, around the stoichiometric air-fuel ratio. The operation of this control means 16 can be controlled in various ways as follows. In other words.
(1)空燃比ムのリーン側とリッチ側の占有時間比率を
適宜のものにする。例えば1:IK、ある(2)空燃比
Vの変動態様を機関運転条件例えば機関回転数や負荷に
応動して変化させ、あるいは変動させず機関運転時の全
域で均一変動態様とする。(1) Adjust the ratio of occupied time on the lean side and rich side of the air-fuel ratio to an appropriate value. For example, 1:IK, a certain (2) air-fuel ratio V is varied in response to engine operating conditions such as engine speed and load, or is not varied and is uniformly varied over the entire area during engine operation.
次に具体例てついて説明する。第4図はこの発明の実施
例の3態様を示すものである。すなわち矢印1. I
I、 Iで示す3例である。Next, a specific example will be explained. FIG. 4 shows three embodiments of the present invention. That is, arrow 1. I
There are three examples indicated by I and I.
まず矢印lで示す第1実施例(点線描図)のエアブリー
ド方式について説明する。図において。First, the air bleed system of the first embodiment (drawn with dotted lines) indicated by arrow l will be described. In fig.
18はベンチュリ、20はフロート室、22は絞り弁。18 is a venturi, 20 is a float chamber, and 22 is a throttle valve.
26はメーン通路、28はメーンノズル、30はスロー
ボートである。前記ベンチュリ18上流側に流入口32
を設け、この流入口32を2次空気通路14の開口始端
とし、前記スローポート30近傍に設は九吐出口34に
この2次空気通路14を開口終端させる。また、この2
次空気通路14途中には電磁弁36を設け。26 is a main passage, 28 is a main nozzle, and 30 is a slow boat. An inlet 32 is provided on the upstream side of the venturi 18.
The inlet port 32 is provided as the opening end of the secondary air passage 14, and the secondary air passage 14 is provided with a discharge port 34 near the slow port 30 as the opening end thereof. Also, these 2
A solenoid valve 36 is provided in the middle of the next air passage 14.
この電磁弁を発信器たるマルチバイブレータ羽によって
開閉制御する。なおこのマルチバイブレータあの稼動に
際し、2次空気通路14を一定周期で開閉制御する場合
にはこのマルチバイブレータ羽を双安定マルチとし、ま
た適宜に周期変更する場合には単安定マルチに設定すれ
ば良い。The opening and closing of this solenoid valve is controlled by a multivibrator blade serving as a transmitter. In addition, when operating this multivibrator, if the secondary air passage 14 is to be controlled to open and close at a constant cycle, the multivibrator blades may be set to bistable multi, or if the cycle is changed appropriately, it may be set to monostable multi. .
上述第1実施例の如く構成すれば、電磁弁36を適宜開
閉制御することによシ空燃比を理論空燃比を挾んだ前後
両側−変化させることができ、前記第2図に示す好まし
い浄化率を示す特性を得ることができる。このため、極
めて簡単な構成でありながら、三元触媒を使用して高能
率の排気浄化を果すことができる。またこのとき空燃比
の平均余り一ン側になるように設定すれば、従来の如く
ワインドクを外れ排気浄化に悪影響を及ぼすという不都
合を生じないばかシか、NOx浄化率を更如改善し得る
という副次的効果を利用することができるとともに燃費
改善をも果すことができるものである。If configured as in the first embodiment, the air-fuel ratio can be changed between the front and rear sides of the stoichiometric air-fuel ratio by appropriately opening and closing the solenoid valve 36, and the preferred purification shown in FIG. 2 can be achieved. It is possible to obtain characteristics that indicate the rate. Therefore, although the configuration is extremely simple, highly efficient exhaust gas purification can be achieved using the three-way catalyst. In addition, if the air-fuel ratio is set so that the average remainder is 1 in, this will not only prevent the inconvenience of the air-fuel ratio from being out of tune as in the past and have a negative effect on exhaust purification, but it will also further improve the NOx purification rate. This makes it possible to utilize secondary effects and also improve fuel efficiency.
次に第4図の矢印■で示す第2実施例(一点鎖線描図)
のジェット方式忙ついて説明する。この実施例の特徴と
するところは、電磁弁36−2に連なる2次空気通路1
4−2の開口終端たる吐出日別−2をメーン通路26途
中に設け、メーンノズル28から噴出される混合気に予
め空気を混入させ、燃料の気化を良好とする作間をも考
慮した点にあるなお36−2は電磁弁である。Next, the second embodiment (dotted chain line drawing) shown by the arrow ■ in Fig. 4
The jet method is explained in detail. This embodiment is characterized by a secondary air passage 1 connected to the solenoid valve 36-2.
The discharge date-2, which is the opening end of 4-2, is provided in the middle of the main passage 26, and air is mixed in advance into the air-fuel mixture ejected from the main nozzle 28, so that the fuel vaporization is improved. Note that 36-2 is a solenoid valve.
次に矢印■で示す第3実施例(二点@線描図)の吸気管
方式について説明する。この第3実施例の特徴は2次空
気通路14−3の開口終端たる吐出口:14−3を、絞
り弁22下流側の吸気通路6に開口させた点にある。な
お36−3は電磁弁である。そしてこのように構成すれ
ば、複雑な構造の気化器近傍に手を加えることなく、簡
単な構成で2次空気通路を構成することができる。Next, an explanation will be given of the intake pipe system of the third embodiment (two points @ line drawing) indicated by the arrow ■. The feature of this third embodiment is that the discharge port 14-3, which is the opening end of the secondary air passage 14-3, is opened into the intake passage 6 on the downstream side of the throttle valve 22. Note that 36-3 is a solenoid valve. With this configuration, the secondary air passage can be configured with a simple configuration without modifying the vicinity of the carburetor, which has a complicated structure.
なお吸気系に2次空気を投入することによる機関不安定
化の不都合は空燃比の変動によるウィンドウの広がりと
1機関の安定性との比較考量によって決定することがで
き、所望の性能を有する機関を得ることができ、徒に機
関不安定の欠点を招いてしまう不都合はない。 −
なおこの発明は上記実施例に限定されず種々の応用改変
が可能である。The disadvantage of engine instability caused by injecting secondary air into the intake system can be determined by comparing the window widening due to air-fuel ratio fluctuations with the stability of one engine, and it is possible to determine whether the engine has the desired performance. can be obtained, and there is no inconvenience of unnecessarily incurring the drawback of engine instability. - Note that this invention is not limited to the above embodiments and can be modified in various ways.
例えば、上述実施例においては2次空気を吸気系にのみ
投入して空燃比の制御を行ったが、排気系つまり内燃機
関の下流側に2次空気を投入する方式と組合せて空燃比
制御を行う構成とすることも可能である。For example, in the above embodiment, the air-fuel ratio was controlled by injecting secondary air only into the intake system, but the air-fuel ratio can be controlled in combination with a method in which secondary air is injected into the exhaust system, that is, the downstream side of the internal combustion engine. It is also possible to have a configuration in which this is done.
また、NO!低減に有効なEGR方式とこの発明の方式
とを併用することもでき、このようにすれば、全幅の運
転域において機関の性能を損なうことなく、一層の排気
浄化を果すことができる。Also, NO! It is also possible to use the EGR method effective for reduction and the method of the present invention in combination, and in this way, further exhaust purification can be achieved without impairing the performance of the engine over the entire operating range.
更にまた。上述実施例においては三元触媒装置について
説明したが、いうまでもなく酸化触媒あるいは還元触媒
にもこの発明を応用し得る。Yet again. In the above embodiments, a three-way catalyst device has been described, but it goes without saying that the present invention can also be applied to an oxidation catalyst or a reduction catalyst.
以上詳細な説明から明らかなように、この発明は従来装
置の如<o2センサを利用したフィードバック制御シス
テムではなく、開ループ方式として装置を極めて簡単に
構成することができ、排気浄化を果すことができる。ま
た従来装置の如くシステムの時間遅れもなく、空燃比の
変動周期および振幅は所定のものであプ1機関のハンチ
ング等の不安定さもなく、触媒の劣化を来たすという不
都合もない。また平均空燃比Vをリーン(希薄)側に設
定すれば燃費の改善をも果すことができるまた空燃比変
動周期や振幅およびその片寄りを自由に設定し得るので
2機関の諸性能を考慮しての対処が可能で機関や触媒装
置の耐久性を高め得る。As is clear from the above detailed description, the present invention is not a feedback control system using an O2 sensor like the conventional device, but can be configured extremely easily as an open loop system, and is capable of purifying exhaust gas. can. Further, there is no time delay in the system as in conventional devices, the fluctuation period and amplitude of the air-fuel ratio are predetermined, there is no instability such as hunting in the engine, and there is no inconvenience such as deterioration of the catalyst. Furthermore, if the average air-fuel ratio V is set to the lean side, fuel efficiency can be improved.Also, since the air-fuel ratio fluctuation period, amplitude, and its deviation can be freely set, the performance of the two engines can be taken into consideration. This can improve the durability of the engine and catalyst device.
第1図は定常運転下における空燃比と浄化率の3成分の
特性を示すグラフ、第2図は理論空燃比を挾むように空
燃比を変動させた場合の浄化率を示すグラフ、第3図は
この発明の原理を示す系統図、第4図はこの発明の第1
〜3実施例を示す概略図で6る。
図において、2はエヤクリーナ、4は気化器。
6は吸気通路、8は内燃機関、lOは排気通路、 12
は三元触媒装置、 14は2次空気通路、 16は空燃
比制御手段である。
代理人 弁理士 西 郷 義 美
第1図
第2図
手続補正書(自発)
昭和57年3月 1日
特許庁長官 島 1)春 樹 殿
1、事件の表示
q#願昭56−105698
2発明の名称
触媒装置の吸気系空燃比制御装置
3、補正をする者
事件との関係 特許出願人
静岡県浜名都可美村高塚300番地
(208) M木自動車工業株式会社
代表者 鉤 木 修
4、代 理 人 〒105 電話438−2241(
代表)東京都港区虎ノ門3丁目4番17号
6、補正の対象 (1)明細書全文
(2)図面
7・補正の内容 、、、/、、 、
、1、全文訂正明細書
1、発明の名称 触媒装置の吸気系空燃比制御装置
2、特許請求の範囲
触媒装置により排気浄化を行う内燃機関において、燃焼
室前の吸気系に導入する2次吸入空気量又は燃料を変化
させて空燃比を理論空燃比の前後に強制的に変動させる
空燃比制御手段を設けたことを特徴とする触媒装置の吸
気系空燃比制御装置。
3、発明の詳細な説明
この発明は、燃焼室前の吸気系に導入する2次吸入空気
量を変化させて、空燃比を理論空燃比を挾んでその前後
に強制的に変動させた触媒装置の吸気系空燃比制御装置
に関する。
触媒装置例えば三元触媒装置を有効に作用させるために
は、その装置に導入される排気ガスの成分、特に酸素濃
度を非常に精度良く制御しなければならない。そこで三
元触媒装置を用いる場合には2次吸入空気の制御を厳密
に行い、第1図に示す如く、空燃比をウィンドウ内に保
り必要がある・なおこのウィンドウ社理論空燃比(化学
量論比)の±0.1〜±0.15程度の狭すものである
。このためe 02センサが使用され、いわゆる空燃比
フィードバックシステムが必要となる・
しかし上記従来のシステムは制御方法が極めて複雑であ
り、その結果制御装置も複雑となシ、高価でしかも故障
が多いという欠点があった。またフィードバック制御に
はシステムの時間遅れが存在するという不都合もある。
そこでこの発明の目的は、極めて簡単な制御装置でNO
xの浄化を行い触媒の耐久性をも向上させ。
燃費改善に寄与し得る触媒装置の吸気系空燃比制御装置
を実現するにある。
以下図面に基づいてこの発明の詳細な説明する。この発
明の理解を容易にするために、まず第2図のグラフにつ
いて説明する・このグラフ社縦軸に浄化率(5)、横軸
に空燃比をと9.理論空燃比を挾むような空燃比の周期
的な変動、つまシリーン(希薄)とリッチ(過濃)への
強制変動によって、浄化率がどのように変化するかを実
験した結果を示すものである。なおこの周期は例えば0
.1〜2秒で空燃比Y±0.2〜±111度である。そ
してこの第1図のグラフによると、全体的に浄化率は少
々落ちるが、3本のグラフ Co 、 IC、NOxの
全てが肩をなだらかにし、更に裾を広げる特性を示すこ
とが理解できる。つま)ウィンドウが定常運転下に比べ
幾分広がるものである。これは触媒の酸素吸着(オキシ
デンストレー−))によるものと考えられる。そしてこ
のように空燃比を変動させると、り一ン域においてNO
x浄化率の向上という副次的効果をも得る。
この性質に着目し、第3図の如く、制御装置を構成する
。すなわち、2はエヤクリーナ、4は気化器、6は吸気
通路、8は内燃機関、loは排気通路そして12は三元
触媒装置である。前記吸気通路6や気化器4等の吸気系
には2次吸入空気通路14を連通させ、該2次吸入空気
通路14の始端は好ましくは前記エヤクリーナ2に連通
させる。
そしてこの2次吸入空気通路14:i!i中に紘後述す
る電磁弁等からなる空燃比を変動させるための空燃比制
御手段16を介在させる。そしてこの制御手段16によ
シ内燃機関8に投入する空燃比、すなわち三元触媒装置
12人口の空燃比を理論空燃比を挾んでその前後に変動
させるのである。なおこの制御手段16の作動は次の如
く穫々の制御態様にすることができる。つまり。
(1)空燃比へのリーン側とリッチ側の占有時間北本な
適宜のものにする。例えば1:1に、あるいはリーン側
を2としリッチ側を1すなわち2:1に設定する。
(2)空燃比^の変動態様を機関運転条件例えば機関回
転数や負荷に応動して変化させ、あるいは変動させず機
関運転時の全域で均一変動態様とする・
次に具体例について説明する。第4図はこの発明の実施
例の3態様を示すものである。すなわち矢印1.■、1
で示す3例である。
まず矢印!で示す第1実施′@(点線描図)のエアブリ
ード方式につ込て説明する。図において。
18はベンチュリ、20はフロート室、22は絞多弁、
26はメーン通路、28はメインノズル。
30はスローポート、33はアイドル/−)である、前
記ベンチュリ18上流側にメインエアジェツト32を設
け、第4図示の如く、このメインエアジェツト32とジ
ェット31間に吐出口17を有するメイン側の2次吸入
空気通路14m を設ける。また、同様に第4図示の
如く、スロー側として2次吸入空気通路141 を設け
1.この通路14゜の吐出開口34をスローポート30
近傍のスロー通路に開口させる。そして前記メイン側と
スロー側の2次吸入空気通路14□、14.を上流部に
おいて合流し1通路19に連通し、この通路19を大気
に開口する。また、この合流部には電磁弁36を介設し
、この電磁弁36を発信器たるマルチバイブレータ38
によって開閉制御する。なおこのマルチバイブレータ3
8の稼動に際し、2次吸入空気通路14を一定周期で開
閉制御する場合にはこのマルチバイブレータ38を双安
定マルチとし、また適宜に周期変更する場合には単安定
iルチに設定すれば良い。
上述第1実施例の如く構成すれば、電磁弁36を適宜開
閉制御することによシ空燃比を理論空燃比を挾んだ前後
両側に変化させることができ、前記第2図に示す好まし
い浄化率を示す特性を得ることができる。このため、極
めて簡単な構成であり表から、三元触媒を使用して高能
率の排気浄化を果すことができる。またこのとき空燃比
の平均をリーン側になるように設定すれば、従来の如く
ウィンドウを外れ排気浄化に悪影響を及ぼすという不都
合を生じないばかシか、 NOx浄化率を更に改善し得
るという副次的効果を利用することができるとともに燃
費改善をも果すことができるものである。
次に第4図の矢印■で示す第2実施例(一点鎖線描図)
Uエツト方式について説明する。この実施例の特徴とす
るところは、メインジェット35を迂回するバイパス3
7を設け、このパイ/母ス37を電磁弁36−2によシ
開閉することによシ燃料の増減を行い、もって、空燃比
を変化させる点にある。
次に矢印■で示す第3奥施例(二点鎖線描図)の吸気管
方式について説明する。この第3実施例の特徴は2次吸
入空気通路14−3の開口終端たる吐出口34−3を、
絞シ弁22下流側の吸気通路6に開口させた点にある。
力お36−3は電磁弁である。そしてこのように構成す
れば、複雑な構造の気化器近傍に手を加えることなく、
簡単な構成で2次空気通路を構成することができる。
なお吸気系に2次吸入空気を投入することによる機関不
安定化の不都合は空燃比の変動によるウィンドウの広が
りと9機関の安定性との比較考量によって決定すること
ができ、所望の性能を有する機関を得ることができ、徒
に機関不安定の欠点を招いてしまう不都合はない。
なおこの発明は上記実施例は限定されず種々の応用改変
が可能である。
例えば、上述実施例においては2次吸入空気を吸気系に
のみ投入して空燃比の制御を行ったが。
排気系つt99態様関の下流側に2次空気を投入する方
式と組合せて空燃比制御を行う゛構成とすることも可能
である。
また+ NOx低減に有効なEGR方式とこの発明の方
式とを併用することもでき、このようにすれば。
全幅の運転域において機関の性能を損なうことなく、一
層の排気浄化を果すことができる。
更にまた。上述実施例においては三元触媒装置について
説明したが、いうまでもなく酸化触媒あるいは還元触媒
にもこの発明を応用し得る。
以上詳細な説明から明らかなように、この発明は従来装
置の如く0□センサを利用したフィードバック制御シス
テムではなく、開ループ方式として装置を極めて簡単に
構成することができ、排気浄化を果すことができる。ま
た従来装置の如くシステムの時間遅れもなく、空燃比の
変動周期および振幅は所定のものであシ22機関ハンチ
ング等の不安定さもなく、触媒の劣化を来たすという不
都合もない。また平均空燃比Aをリーン(希薄)側に設
定すれば燃費の改善をも果すことができる。
また空燃比変動周期や振幅およびその片寄夛を自由に設
定し得るので9機関の諸性能を考慮しての対処が可能で
機関や触媒装置の耐久性を高め得る。
4、図面の簡単な説明
第1図は定常運転下における空燃比と浄化率の3成分の
特性を示すグラフ、第2図は理論空燃比を挾むように空
燃比を変動させた場合の浄化率を示すグラフ、第3図は
この発明の原理を示す系統図、第4図はこの発明の第1
〜3実施例を示す概略図である。
図において、2はエヤクリーナ、4は気化器。
6は吸気通路、8は内燃機関、10は排気通路。
12は三元触媒装置、 14m、 14.は2次吸入空
気通路、16は空燃比制御手段である。
代理人 弁理士 西 郷 義 美Figure 1 is a graph showing the characteristics of the three components of air-fuel ratio and purification rate under steady-state operation, Figure 2 is a graph showing the purification rate when the air-fuel ratio is varied around the stoichiometric air-fuel ratio, and Figure 3 is a graph showing the purification rate when the air-fuel ratio is varied around the stoichiometric air-fuel ratio. The system diagram showing the principle of this invention, Figure 4, is the first diagram of this invention.
Figure 6 is a schematic diagram showing three embodiments. In the figure, 2 is an air cleaner and 4 is a carburetor. 6 is an intake passage, 8 is an internal combustion engine, IO is an exhaust passage, 12
1 is a three-way catalyst device, 14 is a secondary air passage, and 16 is an air-fuel ratio control means. Agent Patent Attorney Yoshimi Saigo Figure 1 Figure 2 Procedural Amendment (Voluntary) March 1, 1980 Commissioner of the Patent Office Shima 1) Haruki Tono 1, Case Indication q# Application 1982-105698 2 Invention Name of catalytic device intake system air-fuel ratio control device 3, relationship with the case of the person making the amendment Patent applicant 300 Takatsuka, Kamimura, Hamana, Shizuoka Prefecture (208) M-Ki Jidosha Kogyo Co., Ltd. Representative Osamu Kagiri 4; Agent 〒105 Telephone 438-2241 (
Representative) 3-4-17-6 Toranomon, Minato-ku, Tokyo Subject of amendment (1) Full text of specification (2) Drawing 7・Contents of amendment , , / , , ,
, 1. Full text correction specification 1. Title of the invention Intake system air-fuel ratio control device for catalyst device 2. Claims In an internal combustion engine that performs exhaust purification by a catalyst device, a secondary intake system introduced into the intake system before the combustion chamber. 1. An intake system air-fuel ratio control device for a catalyst device, comprising an air-fuel ratio control means for forcibly changing the air-fuel ratio around a stoichiometric air-fuel ratio by changing the amount of air or fuel. 3. Detailed Description of the Invention This invention provides a catalyst device that forcibly changes the air-fuel ratio around the stoichiometric air-fuel ratio by changing the amount of secondary intake air introduced into the intake system in front of the combustion chamber. The present invention relates to an intake system air-fuel ratio control device. In order for a catalyst device, such as a three-way catalyst device, to function effectively, the components of the exhaust gas introduced into the device, particularly the oxygen concentration, must be controlled with great precision. Therefore, when using a three-way catalyst device, it is necessary to strictly control the secondary intake air and maintain the air-fuel ratio within the window as shown in Figure 1. The theoretical ratio) is about ±0.1 to ±0.15. For this reason, an e02 sensor is used, and a so-called air-fuel ratio feedback system is required. However, the control method of the conventional system described above is extremely complicated, and as a result, the control device is also complex, expensive, and prone to failure. There were drawbacks. Feedback control also has the disadvantage that there is a time delay in the system. Therefore, the purpose of this invention is to achieve NO.
It also purifies x and improves the durability of the catalyst. The object of the present invention is to realize an intake system air-fuel ratio control device for a catalyst device that can contribute to improving fuel efficiency. The present invention will be described in detail below based on the drawings. In order to facilitate understanding of this invention, we will first explain the graph in Figure 2.The vertical axis of this graph represents the purification rate (5), and the horizontal axis represents the air-fuel ratio.9. This shows the results of an experiment to see how the purification rate changes due to periodic fluctuations in the air-fuel ratio that interfere with the stoichiometric air-fuel ratio, and forced fluctuations from lean to rich. . Note that this period is, for example, 0
.. The air-fuel ratio Y is ±0.2 to ±111 degrees in 1 to 2 seconds. According to the graph in Fig. 1, although the overall purification rate is a little lower, it can be seen that all three graphs, Co, IC, and NOx, exhibit characteristics of gentle shoulders and further widening of the tails. Finally, the window is slightly wider than under normal operation. This is thought to be due to oxygen adsorption (oxygen stray) of the catalyst. When the air-fuel ratio is varied in this way, NO.
x A secondary effect of improving the purification rate is also obtained. Focusing on this property, a control device is constructed as shown in FIG. That is, 2 is an air cleaner, 4 is a carburetor, 6 is an intake passage, 8 is an internal combustion engine, lo is an exhaust passage, and 12 is a three-way catalyst device. A secondary intake air passage 14 is communicated with the intake system such as the intake passage 6 and the carburetor 4, and the starting end of the secondary intake air passage 14 is preferably communicated with the air cleaner 2. And this secondary intake air passage 14:i! An air-fuel ratio control means 16 for varying the air-fuel ratio consisting of a solenoid valve or the like, which will be described later, is interposed in the air-fuel ratio control section i. The control means 16 is used to vary the air-fuel ratio input to the internal combustion engine 8, that is, the air-fuel ratio of the three-way catalyst device 12, around the stoichiometric air-fuel ratio. The operation of the control means 16 can be controlled in various ways as follows. In other words. (1) The time occupied by the lean side and rich side of the air-fuel ratio should be set appropriately. For example, the ratio is set to 1:1, or the lean side is set to 2 and the rich side is set to 1, that is, 2:1. (2) The air-fuel ratio is varied in response to engine operating conditions such as engine speed and load, or is not varied and is made to vary uniformly over the entire area during engine operation. Next, a specific example will be described. FIG. 4 shows three embodiments of the present invention. That is, arrow 1. ■, 1
Here are three examples. First, the arrow! The air bleed system of the first implementation '@ (dotted line) will be explained in detail. In fig. 18 is a venturi, 20 is a float chamber, 22 is a throttle valve,
26 is the main passage, 28 is the main nozzle. 30 is a slow port, 33 is an idle/-), a main air jet 32 is provided upstream of the venturi 18, and as shown in the fourth figure, a main side having a discharge port 17 between the main air jet 32 and the jet 31. A 14m secondary intake air passage will be provided. Similarly, as shown in Figure 4, a secondary intake air passage 141 is provided on the slow side. The discharge opening 34 of this passage 14° is connected to the slow port 30.
Open to the nearby slow passage. And the main side and slow side secondary intake air passages 14□, 14. The two converge at the upstream portion and communicate with one passage 19, and this passage 19 is opened to the atmosphere. Further, a solenoid valve 36 is interposed in this confluence part, and this solenoid valve 36 is used as a multivibrator 38 which is a transmitter.
Opening/closing is controlled by Furthermore, this multivibrator 3
8, if the secondary intake air passage 14 is to be controlled to open and close at a constant cycle, the multivibrator 38 may be set to a bistable multivibrator, and if the cycle is to be changed appropriately, the multivibrator 38 may be set to a monostable i-multivibrator. If configured as in the first embodiment described above, the air-fuel ratio can be changed to both sides of the stoichiometric air-fuel ratio by appropriately opening and closing the solenoid valve 36, and the preferable purification shown in FIG. 2 can be achieved. It is possible to obtain characteristics that indicate the rate. Therefore, the configuration is extremely simple, and as shown in the table, highly efficient exhaust gas purification can be achieved using a three-way catalyst. Also, if the average air-fuel ratio is set to be on the lean side at this time, it will not cause the inconvenience of going out of the window and adversely affecting exhaust purification as in the past, but it will also improve the NOx purification rate. This makes it possible to take advantage of the practical effects and also improve fuel efficiency. Next, the second embodiment (dotted chain line drawing) shown by the arrow ■ in Fig. 4
The Uet method will be explained. This embodiment is characterized by a bypass 3 that bypasses the main jet 35.
7 is provided, and by opening and closing this pi/base 37 by a solenoid valve 36-2, the amount of fuel is increased or decreased, thereby changing the air-fuel ratio. Next, the intake pipe system of the third rear embodiment (drawn with two-dot chain lines) indicated by the arrow ■ will be explained. The feature of this third embodiment is that the discharge port 34-3, which is the opening end of the secondary intake air passage 14-3,
This is because the throttle valve 22 is opened to the intake passage 6 on the downstream side. Force 36-3 is a solenoid valve. With this configuration, it is possible to do this without having to modify the vicinity of the carburetor, which has a complicated structure.
The secondary air passage can be configured with a simple configuration. The inconvenience of engine instability caused by injecting secondary intake air into the intake system can be determined by comparing the window widening due to air-fuel ratio fluctuations and the stability of the nine engines, so that the desired performance can be achieved. The engine can be obtained without the inconvenience of unnecessarily incurring the disadvantage of engine instability. Note that this invention is not limited to the above-mentioned embodiments, and can be modified in various ways. For example, in the above-described embodiment, the air-fuel ratio was controlled by injecting secondary intake air only into the intake system. It is also possible to adopt a configuration in which air-fuel ratio control is performed in combination with a method of injecting secondary air into the downstream side of the exhaust system and the t99 mode connection. Moreover, it is also possible to use the EGR method effective in reducing NOx and the method of the present invention in combination. Further exhaust purification can be achieved without impairing engine performance over the entire operating range. Yet again. In the above embodiments, a three-way catalyst device has been described, but it goes without saying that the present invention can also be applied to an oxidation catalyst or a reduction catalyst. As is clear from the above detailed description, the present invention is not a feedback control system using a 0□ sensor like the conventional device, but can be configured extremely easily as an open loop system, and is capable of purifying exhaust gas. can. In addition, there is no system time delay unlike in conventional systems, the fluctuation period and amplitude of the air-fuel ratio are predetermined, there is no instability such as engine hunting, and there is no inconvenience such as deterioration of the catalyst. Furthermore, if the average air-fuel ratio A is set on the lean side, fuel efficiency can also be improved. In addition, since the air-fuel ratio fluctuation period, amplitude, and bias thereof can be freely set, it is possible to take measures in consideration of various performances of the nine engines, and the durability of the engine and the catalyst device can be improved. 4. Brief explanation of the drawings Figure 1 is a graph showing the characteristics of the three components of air-fuel ratio and purification rate under steady-state operation, and Figure 2 shows the purification rate when the air-fuel ratio is varied around the stoichiometric air-fuel ratio. Figure 3 is a system diagram showing the principle of this invention, Figure 4 is the first diagram of this invention.
It is a schematic diagram showing ~3 Examples. In the figure, 2 is an air cleaner and 4 is a carburetor. 6 is an intake passage, 8 is an internal combustion engine, and 10 is an exhaust passage. 12 is a three-way catalyst device, 14m, 14. 1 is a secondary intake air passage, and 16 is an air-fuel ratio control means. Agent Patent Attorney Yoshimi Saigo
Claims (1)
室前の吸気系に導入する2次空気量を変化させて空燃比
を理論空燃比の前後に強制的に変動させる空燃比制御手
段を設けたことを特徴とする触媒装置の吸気系空燃比制
御装置。In an internal combustion engine that performs exhaust gas purification using a catalyst device, an air-fuel ratio control means is provided for forcibly changing the air-fuel ratio around the stoichiometric air-fuel ratio by changing the amount of secondary air introduced into the intake system in front of the combustion chamber. An intake system air-fuel ratio control device for a catalyst device, characterized in that:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10569881A JPS588244A (en) | 1981-07-08 | 1981-07-08 | Suction system air-fuel ratio controller for catalytic device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10569881A JPS588244A (en) | 1981-07-08 | 1981-07-08 | Suction system air-fuel ratio controller for catalytic device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS588244A true JPS588244A (en) | 1983-01-18 |
Family
ID=14414588
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP10569881A Pending JPS588244A (en) | 1981-07-08 | 1981-07-08 | Suction system air-fuel ratio controller for catalytic device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS588244A (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5457013A (en) * | 1977-10-15 | 1979-05-08 | Toyota Motor Corp | Secondary air supply rate control system |
JPS54150513A (en) * | 1978-05-18 | 1979-11-26 | Toyota Motor Corp | Controller of quantity of secondary air fed |
JPS564741A (en) * | 1979-04-11 | 1981-01-19 | Moplefan Spa | High speed loom for making bag weaving by yarn * strap or similar material made from synthetic or natural substance |
-
1981
- 1981-07-08 JP JP10569881A patent/JPS588244A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5457013A (en) * | 1977-10-15 | 1979-05-08 | Toyota Motor Corp | Secondary air supply rate control system |
JPS54150513A (en) * | 1978-05-18 | 1979-11-26 | Toyota Motor Corp | Controller of quantity of secondary air fed |
JPS564741A (en) * | 1979-04-11 | 1981-01-19 | Moplefan Spa | High speed loom for making bag weaving by yarn * strap or similar material made from synthetic or natural substance |
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