JPS6214349Y2 - - Google Patents

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Publication number
JPS6214349Y2
JPS6214349Y2 JP2653186U JP2653186U JPS6214349Y2 JP S6214349 Y2 JPS6214349 Y2 JP S6214349Y2 JP 2653186 U JP2653186 U JP 2653186U JP 2653186 U JP2653186 U JP 2653186U JP S6214349 Y2 JPS6214349 Y2 JP S6214349Y2
Authority
JP
Japan
Prior art keywords
air
oxygen concentration
concentration detector
fuel ratio
detection element
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
Application number
JP2653186U
Other languages
Japanese (ja)
Other versions
JPS61147344U (en
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed filed Critical
Priority to JP2653186U priority Critical patent/JPS6214349Y2/ja
Publication of JPS61147344U publication Critical patent/JPS61147344U/ja
Application granted granted Critical
Publication of JPS6214349Y2 publication Critical patent/JPS6214349Y2/ja
Expired legal-status Critical Current

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  • Exhaust Silencers (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)
  • Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)

Description

【考案の詳細な説明】 〔産業上の利用分野〕 本考案は内燃機関の排気系に設けられる総合空
燃比検出装置に関する。
[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a comprehensive air-fuel ratio detection device provided in the exhaust system of an internal combustion engine.

〔従来の技術および問題点〕[Conventional technology and problems]

内燃機関の排気中に含まれる一酸化炭素
(CO)、炭化水素(HC)および酸化窒素(NOx)
等の有害物質を除去する方法として種々の方法が
ある。その方法の一つに内燃機関排気系に酸化触
媒、還元触媒またはその両機能を具えた三元触媒
からなる触媒コンバータを設け、排気中のCO,
HC,NOx等の有害物質を浄化する方法がある。
この場合、特に三元触媒を用いた場合には、内燃
機関の吸気系から排気系までの全供給空気重量と
燃料重量の比として定義される総合空燃比を理論
空燃比に制御することにより触媒コンバータの浄
化効率が最大となる。
Carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) contained in internal combustion engine exhaust gas
There are various methods for removing harmful substances such as: One method is to install a catalytic converter consisting of an oxidation catalyst, a reduction catalyst, or a three-way catalyst with both functions in the exhaust system of an internal combustion engine.
There are methods to purify harmful substances such as HC and NOx.
In this case, especially when a three-way catalyst is used, the catalyst is The purification efficiency of the converter is maximized.

そこで従来、内燃機関の排気系内の触媒コンバ
ータ上流に酸素濃度検知器を設け、この検知器の
検知信号により排気系内に二次空気を供給し(二
次空気供給方式)または吸気系へ供給する燃料量
を調整しフイードバツク制御して、総合空燃比を
理論空燃比とすることが行われている。(酸素濃
度検知器はジルコニア等の磁器材料の酸素濃淡電
池の原理を応用している。) ところが、例えば機関負荷が大きく、かつ回転
数が高くなると、排気ガス温度が上昇するために
酸素濃度検知器の検知素子が高温になつて熱劣化
し、これにより酸素濃度検知器の検知精度が低下
して空燃比のフイードバツク制御が困難になると
いう問題を生じる。
Conventionally, an oxygen concentration detector is installed upstream of the catalytic converter in the exhaust system of an internal combustion engine, and secondary air is supplied into the exhaust system (secondary air supply method) or to the intake system based on the detection signal from this detector. The total air-fuel ratio is adjusted to the stoichiometric air-fuel ratio by adjusting the amount of fuel used and performing feedback control. (The oxygen concentration detector applies the principle of an oxygen concentration battery made of porcelain materials such as zirconia.) However, for example, when the engine load is large and the rotation speed increases, the exhaust gas temperature rises, making it difficult to detect the oxygen concentration. The detection element of the oxygen concentration detector becomes hot and thermally deteriorates, which causes a problem in that the detection accuracy of the oxygen concentration detector decreases and feedback control of the air-fuel ratio becomes difficult.

〔問題点を解決するための手段〕[Means for solving problems]

本考案に係る総合空燃比検出装置は、内燃機関
の排気管内に設けられた酸素濃度検知器と、この
酸素濃度検知器の検知素子の温度を検出する手段
と、該検出素子が高温のとき上記酸素濃度検知器
に冷却用の二次空気を供給する手段とを備えるこ
とを特徴としている。
The comprehensive air-fuel ratio detection device according to the present invention includes an oxygen concentration detector installed in an exhaust pipe of an internal combustion engine, a means for detecting the temperature of a detection element of the oxygen concentration detector, and a means for detecting the temperature of a detection element of the oxygen concentration detector, and The oxygen concentration detector is characterized by comprising means for supplying secondary air for cooling to the oxygen concentration detector.

〔実施例〕〔Example〕

以下図面を参照して説明する。第1図は本発明
第1の実施例であり、図において内燃機関1の排
気系の排気管2に触媒コンバータ(図示せず)を
設ける。この触媒コンバータの上流に酸素濃度検
知器3を取付け、検知器3の検知信号をコンピユ
ータ4で基本演算しその結果により空気制御弁5
を制御する。空気制御弁5はフイルタ6から内燃
機関1に連動するエアポンプ7を経て供給される
二次空気を逆流防止用チエツク弁8を経てエアチ
ユーブ9から内燃機関1の排気ポート1aを近傍
に供給する。しかして酸素濃度検知器3で総合空
燃比が過濃であることを検知するとエアチユーブ
9から二次空気を供給し、逆に希薄であることを
検知すると二次空気量を減じて総合空燃比を理論
空燃比に制御する。
This will be explained below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which a catalytic converter (not shown) is provided in an exhaust pipe 2 of an exhaust system of an internal combustion engine 1. In FIG. An oxygen concentration detector 3 is installed upstream of this catalytic converter, and the detection signal of the detector 3 is basically calculated by a computer 4, and the air control valve 5 is
control. The air control valve 5 supplies secondary air supplied from the filter 6 via the air pump 7 linked to the internal combustion engine 1 to the exhaust port 1a of the internal combustion engine 1 from the air tube 9 via the check valve 8 for preventing backflow. When the oxygen concentration detector 3 detects that the overall air-fuel ratio is too rich, secondary air is supplied from the air tube 9, and conversely, when it detects that the overall air-fuel ratio is too lean, the secondary air amount is reduced to adjust the overall air-fuel ratio. Control to stoichiometric air-fuel ratio.

しかしながら、かかる装置では検知器への未燃
成分付着現象により第2図に鎖線で示す如く酸素
濃度検知器の出力電圧が実際の総合空燃比(実
線)に対し希薄側に偏ることがあり、この場合に
実際の総合空燃比が理論空燃比にあるにもかかわ
らず制御系は総合空燃比が過濃側にある如く作動
する。
However, in such a device, the output voltage of the oxygen concentration detector may deviate to the lean side with respect to the actual total air-fuel ratio (solid line), as shown by the chain line in Figure 2, due to the phenomenon of unburned components adhering to the detector. In this case, even though the actual total air-fuel ratio is at the stoichiometric air-fuel ratio, the control system operates as if the total air-fuel ratio is on the rich side.

そこで前記酸素濃度検知器3の検知素子(図で
は保護カバー3a内にあり見えない)近傍に向け
て微量空気(矢印a)を吹出す小管10を設け、
該小管10をコンピユータ4により作動される制
御弁11を経てエアポンプ7に連通する。しかし
て小管10から吹出した微量空気は検知素子周辺
の雰囲気の局部空燃比を排気系の総合空燃比に対
し僅かに希薄化し前述の未燃成分による酸素濃度
検知器3の過濃誤判定を相殺せしめる。従つてこ
の補償用空気量を機関の吸気量および総合空燃比
に比例して制御弁11で制御すると酸素濃度検知
器3の出力電圧特性は第2図実線に示す如く実際
の排気総合空燃比に一致する。また上述の補償用
空気量は微量であるので、この補償用空気の注入
により総合空燃比を変化させることもほとんどな
い。
Therefore, a small tube 10 is provided to blow out a small amount of air (arrow a) toward the vicinity of the detection element of the oxygen concentration detector 3 (in the figure, it is inside the protective cover 3a and cannot be seen).
The small pipe 10 is connected to an air pump 7 via a control valve 11 operated by a computer 4. Therefore, the small amount of air blown out from the small tube 10 slightly dilutes the local air-fuel ratio of the atmosphere around the detection element with respect to the overall air-fuel ratio of the exhaust system, thereby offsetting the erroneous determination of excess concentration by the oxygen concentration detector 3 due to the unburned components mentioned above. urge Therefore, if this compensation air amount is controlled by the control valve 11 in proportion to the intake air amount and the total air-fuel ratio of the engine, the output voltage characteristic of the oxygen concentration detector 3 will change to the actual exhaust air-fuel ratio as shown by the solid line in FIG. Match. Furthermore, since the above-mentioned amount of compensation air is very small, the injection of this compensation air hardly changes the overall air-fuel ratio.

更に上述の補償用空気注入の効果を微量空気で
効率よく達成するために、例えば酸素濃度検知器
3のカバー3aの外側を多孔を有する蔽い13で
蔽い、雰囲気補償用空気(矢印a)が排気(矢印
G)により大きく乱されることなく検知素子に到
達するようにすることが好ましい。また小管10
からの雰囲気補償用空気は特に制御を加えること
なく(制御弁11を設けず)絞り要素を介して常
時吹き出させてもよく、これによつても酸素濃度
検知器3の特性を実質的に改善できる。更に雰囲
気補償用空気を空気制御弁5の下流から供給して
もよい。
Furthermore, in order to efficiently achieve the effect of the above-mentioned compensation air injection with a small amount of air, for example, the outside of the cover 3a of the oxygen concentration detector 3 is covered with a shield 13 having holes, and the atmosphere compensation air (arrow a) is It is preferable that the gas reaches the sensing element without being significantly disturbed by the exhaust gas (arrow G). Also, small tube 10
The atmosphere compensation air may be constantly blown out through a throttling element without any particular control (no control valve 11 is provided), and this also substantially improves the characteristics of the oxygen concentration detector 3. can. Furthermore, atmosphere compensation air may be supplied from downstream of the air control valve 5.

さて本実施例において、小管10は酸素濃度検
知器3の検知素子が高温になつた場合にこの酸素
濃度検知器3に冷却用の二次空気を供給する作用
も果たす。検知素子が高温であるか否かを判定す
るため、本実施例では、エアフローメータ21か
ら得られる吸入空気量と回転数センサ22から得
られる機関回転数とを用いる。すなわち(吸入空
気量/機関回転数)の値を機関負荷とみなし、こ
の機関負荷と機関回転数がそれぞれある大きさ以
上に達している時、つまり高速高負荷時、検知素
子は高温であると判定する。しかして高速高負荷
時、コンピユータ4は制御弁11を介して小管1
0からの空気量を増量し、検知素子を冷却する。
なお、排気ガス温を検出し、これにより検知素子
の温度を判定するようにしてもよい。
In this embodiment, the small tube 10 also functions to supply secondary air for cooling to the oxygen concentration detector 3 when the detection element of the oxygen concentration detector 3 becomes hot. In this embodiment, the intake air amount obtained from the air flow meter 21 and the engine rotational speed obtained from the rotational speed sensor 22 are used to determine whether or not the detection element is at a high temperature. In other words, the value of (intake air amount/engine speed) is regarded as the engine load, and when the engine load and engine speed each reach a certain level or higher, that is, at high speed and high load, the sensing element will detect a high temperature. judge. Therefore, at high speed and high load, the computer 4 controls the small pipe 1 through the control valve 11.
Increase the amount of air from 0 to cool the sensing element.
Note that the temperature of the sensing element may be determined by detecting the exhaust gas temperature.

本考案の第2実施例、第3実施例を第3図、第
4図を参照して説明する。第3図において酸素濃
度検知器3をアダプタ14を介して排気管2にボ
ルト15締めする。アダプタ14に小管10を取
付け孔14aを穿つとともに該アダプタ14の一
面に孔14aと同心状に座ぐりした座14bを形
成し、多孔を有するスリーブ16を固定する。第
3図に示す総合空燃比検出装置は排気管2にアダ
プタ14、スリーブ16および酸素濃度検知器3
を位置させボルト15により締結することにより
きわめて容易に固定できる。第4図においては酸
素濃度検知器3の保護カバー3aと検知素子3b
の間に雰囲気補償用空気流路を形成するために、
小管10を検知器本体に取付けかつ検知器プラケ
ツト3cに小孔3dを穿つ。第4図に示す総合空
燃比検出装置は装置が一体化しており取扱いが容
易でありかつ雰囲気補償用空気を検知素子3bの
極く近傍に吹出すことができその効果が大きい
が、市販の酸素濃度検知器を改造する必要があ
る。
A second embodiment and a third embodiment of the present invention will be described with reference to FIGS. 3 and 4. In FIG. 3, the oxygen concentration detector 3 is fastened to the exhaust pipe 2 via the adapter 14 with a bolt 15. A hole 14a for attaching the small tube 10 to the adapter 14 is formed, and a seat 14b is formed on one surface of the adapter 14 by concentrically with the hole 14a, and a sleeve 16 having a plurality of holes is fixed thereto. The comprehensive air-fuel ratio detection device shown in FIG.
It can be fixed very easily by positioning and fastening with bolts 15. In Fig. 4, the protective cover 3a and the detection element 3b of the oxygen concentration detector 3 are shown.
To form an air flow path for atmosphere compensation between
Attach the small tube 10 to the detector body and drill a small hole 3d in the detector bracket 3c. The comprehensive air-fuel ratio detection device shown in FIG. 4 is integrated and is easy to handle, and the air for atmosphere compensation can be blown out very close to the detection element 3b, which is highly effective. It is necessary to modify the concentration detector.

なお、本考案はエアポンプにより二次空気を供
給するシステムに限らずエアサクシヨンシステム
においても適用できる。
Note that the present invention is applicable not only to systems that supply secondary air using an air pump but also to air suction systems.

〔考案の効果〕[Effect of idea]

以上のように本考案によれば、酸素濃度検知器
の検知素子の温度を常に一定値以下に保つので酸
素濃度検知器の熱劣化が防止され、総合空燃比の
フイードバツク制御を常に高精度に行なうことが
可能になるという効果が得られる。
As described above, according to the present invention, the temperature of the sensing element of the oxygen concentration detector is always kept below a certain value, so thermal deterioration of the oxygen concentration detector is prevented, and feedback control of the total air-fuel ratio is always performed with high precision. The effect is that it becomes possible to

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

第1図は本考案の一実施例の概略正面図、第2
図は酸素濃度検知器の出力線図、第3図、第4図
はそれぞれ他の実施例の正面図である。 1……内燃機関、2……排気管、3……酸素濃
度検知器、10……小管。
Figure 1 is a schematic front view of one embodiment of the present invention;
The figure is an output diagram of the oxygen concentration detector, and FIGS. 3 and 4 are front views of other embodiments. 1...Internal combustion engine, 2...Exhaust pipe, 3...Oxygen concentration detector, 10...Small pipe.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 内燃機関の排気管内に設けられた酸素濃度検知
器と、この酸素濃度検知器の検知素子の温度を検
出する手段と、該検出素子が高温のとき上記酸素
濃度検知器に冷却用の二次空気を供給する手段と
を備えることを特徴とする総合空燃比検出装置。
An oxygen concentration detector installed in an exhaust pipe of an internal combustion engine, a means for detecting the temperature of a detection element of the oxygen concentration detector, and a means for supplying cooling secondary air to the oxygen concentration detector when the detection element is at a high temperature. A comprehensive air-fuel ratio detection device comprising means for supplying.
JP2653186U 1986-02-27 1986-02-27 Expired JPS6214349Y2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2653186U JPS6214349Y2 (en) 1986-02-27 1986-02-27

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2653186U JPS6214349Y2 (en) 1986-02-27 1986-02-27

Publications (2)

Publication Number Publication Date
JPS61147344U JPS61147344U (en) 1986-09-11
JPS6214349Y2 true JPS6214349Y2 (en) 1987-04-13

Family

ID=30522623

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2653186U Expired JPS6214349Y2 (en) 1986-02-27 1986-02-27

Country Status (1)

Country Link
JP (1) JPS6214349Y2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5098539B2 (en) * 2007-09-27 2012-12-12 トヨタ自動車株式会社 Gas sensor mounting structure
JP6167056B2 (en) * 2014-03-12 2017-07-19 日本特殊陶業株式会社 Gas sensor evaluation method

Also Published As

Publication number Publication date
JPS61147344U (en) 1986-09-11

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