JPH0511294Y2 - - Google Patents
Info
- Publication number
- JPH0511294Y2 JPH0511294Y2 JP1985012738U JP1273885U JPH0511294Y2 JP H0511294 Y2 JPH0511294 Y2 JP H0511294Y2 JP 1985012738 U JP1985012738 U JP 1985012738U JP 1273885 U JP1273885 U JP 1273885U JP H0511294 Y2 JPH0511294 Y2 JP H0511294Y2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- air
- fuel ratio
- bypass
- catalytic converter
- 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 - Lifetime
Links
- 239000007789 gas Substances 0.000 claims description 61
- 230000003197 catalytic effect Effects 0.000 claims description 38
- 239000000446 fuel Substances 0.000 claims description 32
- 238000011144 upstream manufacturing Methods 0.000 claims description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 17
- 229910052760 oxygen Inorganic materials 0.000 claims description 17
- 239000001301 oxygen Substances 0.000 claims description 17
- 238000000746 purification Methods 0.000 claims description 17
- 239000003054 catalyst Substances 0.000 description 23
- 231100000614 poison Toxicity 0.000 description 12
- 239000000126 substance Substances 0.000 description 12
- 230000007096 poisonous effect Effects 0.000 description 11
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- 230000001133 acceleration Effects 0.000 description 3
- 229910002091 carbon monoxide Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000027734 detection of oxygen Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
Landscapes
- Exhaust Gas After Treatment (AREA)
Description
【考案の詳細な説明】
（産業上の利用分野）
本考案は自動車等の内燃機関から排出される排
気ガス中に含まれる有毒物質、例えば炭化水素
（HC）、一酸化炭素（CO）及び窒素酸化物
（NOx）等を除去するための排気ガス浄化装置に
係り、さらに詳しくは排気系路の途中に酸素濃度
検出器又は触媒等の熱害部材を有する自動車用排
気ガス浄化装置に関するものである。[Detailed description of the invention] (Industrial application field) The present invention is designed to deal with toxic substances contained in exhaust gas emitted from internal combustion engines such as automobiles, such as hydrocarbons (HC), carbon monoxide (CO), and nitrogen. This invention relates to an exhaust gas purification device for removing oxides (NOx), etc., and more specifically to an exhaust gas purification device for automobiles that has a heat damage member such as an oxygen concentration detector or a catalyst in the middle of the exhaust system. .
（従来の技術）
一般に自動車等の排出ガス対策として排気系路
に触媒を設け、この触媒と排気ガス中のHC，
CO，NOx等を酸化・還元により無害な物質に化
学反応させるものがあり、三元触媒装置と呼ばれ
ている。(Prior art) Generally, a catalyst is installed in the exhaust system as a measure against exhaust gas from automobiles, etc., and this catalyst and HC in the exhaust gas
There is a device that chemically reacts CO, NOx, etc. into harmless substances by oxidation and reduction, and is called a three-way catalyst device.
上記三元触媒装置を備えた自動車用エンジンに
おいては、三元触媒が最も有効に働く理論空燃比
付近の領域に空燃比を制御する空燃比フイードバ
ツク制御装置が設けられている。この空燃比フイ
ードバツク制御装置は排気系路に酸素濃度検出器
を設け、この酸素濃度検出器により検出した酸素
濃度をコンピユータにより演算処理して吸気系に
制御信号を送出し、空気と燃料との混合割合を制
御するものである。前記酸素濃度検出器として
は、排気ガスと大気との酸素分圧の差に応じて出
力を急変するO2センサ（ジルコニア素子と白金
電極を使用した酸素濃淡電池）が広く知られてい
る。 The automobile engine equipped with the three-way catalyst device is provided with an air-fuel ratio feedback control device that controls the air-fuel ratio in a region around the stoichiometric air-fuel ratio where the three-way catalyst works most effectively. This air-fuel ratio feedback control device is equipped with an oxygen concentration detector in the exhaust system, and a computer processes the oxygen concentration detected by the oxygen concentration detector and sends a control signal to the intake system, thereby controlling the mixing of air and fuel. It controls the ratio. As the oxygen concentration detector, an O 2 sensor (an oxygen concentration battery using a zirconia element and a platinum electrode) whose output changes suddenly depending on the difference in oxygen partial pressure between exhaust gas and the atmosphere is widely known.
ところで、上記三元触媒装置では排気系路に触
媒を充填した触媒コンバータを装着しているが、
排気管に設けるという取付上の理由から１つの触
媒コンバータの大きさには限界がある。そこで、
排気管に２個の触媒コンバータ（以下タンデム型
という）を設けて、この増量された触媒により酸
化及び還元性能の向上を図つているものがある。
前記タンデム型触媒コンバータには、触媒コンバ
ータを排気管の途中に直列に介挿する直列式と、
排気管を分岐させて並列に触媒コンバータを取付
ける並列式とがある。 By the way, in the three-way catalyst device mentioned above, a catalytic converter filled with a catalyst is installed in the exhaust system path.
There is a limit to the size of a single catalytic converter due to its installation in the exhaust pipe. Therefore,
Some exhaust pipes are equipped with two catalytic converters (hereinafter referred to as tandem type) to improve oxidation and reduction performance using the increased amount of catalyst.
The tandem type catalytic converter includes a series type in which the catalytic converter is inserted in series in the middle of the exhaust pipe;
There is a parallel type in which the exhaust pipe is branched and a catalytic converter is installed in parallel.
しかしながら、前者の直列式タンデム型触媒コ
ンバータにおいては、上流側に位置する触媒だけ
が排ガス中の被毒物質（例えば燐、鉛等の金属粒
子）を受け易く、排ガス温度も高いために著しく
烈火することになる。また、下流側に位置する触
媒は、温度の低くなつた排ガスが流入するため、
上流側の触媒が有効に機能しなくなつた状況にお
いて充分な浄化作用を示さない。 However, in the former series tandem catalytic converter, only the catalyst located on the upstream side is susceptible to poisonous substances in the exhaust gas (for example, metal particles such as phosphorus and lead), and the exhaust gas temperature is also high, resulting in extremely violent flames. It turns out. In addition, the catalyst located on the downstream side receives lower temperature exhaust gas, so
In situations where the upstream catalyst no longer functions effectively, it does not exhibit sufficient purifying action.
そこで、従来上記のような直列式タンデム型触
媒コンバータの改良として、「排ガス浄化装置」
（特開昭57−210116号公報参照）が提案されてい
る。 Therefore, as an improvement to the conventional tandem tandem catalytic converter as described above, an "exhaust gas purification device" was developed.
(Refer to Japanese Unexamined Patent Publication No. 57-210116) has been proposed.
この排ガス浄化装置は第３図に示すように構成
されている。すなわち、符号１はエンジン、２は
排気系路、３及び４は触媒コンバータ、３ａ及び
４ａは触媒、５はバイパス、６は切換弁であり、
該切換弁６は以下のように作動する。まず、排気
系路２の上流側触媒コンバータ３の上流側に設け
られた排ガス温度検知器７が、設定温度に対する
排ガス温度の変化を検知して、コンピユータユニ
ツト８へ検出信号を送出し、該コンピユータユニ
ツト８からは電磁弁制御開路９に切換信号が送出
され、該制御回路９の信号により電磁弁１０が開
き、吸気負圧が負圧回路１１と１２を介して負圧
制御弁１３に伝達され、この吸気負圧によりレリ
ーズ１４を変動させて前記切換弁６を作動させ
る。 This exhaust gas purification device is constructed as shown in FIG. That is, 1 is the engine, 2 is the exhaust system, 3 and 4 are the catalytic converters, 3a and 4a are the catalysts, 5 is the bypass, 6 is the switching valve,
The switching valve 6 operates as follows. First, the exhaust gas temperature detector 7 provided on the upstream side of the upstream catalytic converter 3 in the exhaust system path 2 detects a change in exhaust gas temperature with respect to the set temperature and sends a detection signal to the computer unit 8. A switching signal is sent from the unit 8 to the solenoid valve control circuit 9, and the signal from the control circuit 9 opens the solenoid valve 10, and the intake negative pressure is transmitted to the negative pressure control valve 13 via the negative pressure circuits 11 and 12. The release 14 is varied by this intake negative pressure to operate the switching valve 6.
従つて排ガス浄化の過程は次のようになる。エ
ンジン始動直後などのように、温度検知器７によ
り検知される排ガス温度がコンピユータユニツト
８の設定温度よりも低いときは、切換弁６がバイ
パス５の入口を塞いでいるので、排ガスはコンバ
ータ３を経てコンバータ４に到り、排気される。
この場合、コンバータ３はコンバータ４に比較し
てエンジン１に近いため、排ガスは温度を余り低
下することなくコンバータ３に流入するので、触
媒３ａの入ガス温度が高いためコンバータ３の触
媒３ａは高い浄化性能を示す。また、コンバータ
４の触媒４ａはコンバータ３を通過した排ガスに
より暖機されている。 Therefore, the process of exhaust gas purification is as follows. When the exhaust gas temperature detected by the temperature detector 7 is lower than the set temperature of the computer unit 8, such as immediately after starting the engine, the switching valve 6 closes the inlet of the bypass 5, so the exhaust gas flows through the converter 3. The air then reaches the converter 4 and is exhausted.
In this case, since the converter 3 is closer to the engine 1 than the converter 4, the exhaust gas flows into the converter 3 without reducing the temperature much, so the temperature of the gas entering the catalyst 3a is high, so the catalyst 3a of the converter 3 is high. Indicates purification performance. Further, the catalyst 4a of the converter 4 is warmed up by the exhaust gas that has passed through the converter 3.
一方、加速時などのように、温度検知器７によ
り検知される排ガス温度がコンピユータユニツト
８の設定温度より高いときには、切換弁６が移動
してコンバータ３の入口を閉塞するため、排ガス
はバイパス５を経てコンバータ４に到り排気され
る。この場合、コンバータ４はエンジン１から遠
い位置にあるが、上述の始動時等において触媒４
ａの温度は暖機されており、入ガス温度も高いた
め触媒４ａは高い浄化性能を示す。 On the other hand, when the exhaust gas temperature detected by the temperature detector 7 is higher than the set temperature of the computer unit 8, such as during acceleration, the switching valve 6 moves and closes the inlet of the converter 3, so that the exhaust gas is transferred to the bypass 5. The air then reaches the converter 4 and is exhausted. In this case, although the converter 4 is located far from the engine 1, the catalyst 4 is
Since the temperature of catalyst a has been warmed up and the inlet gas temperature is also high, catalyst 4a exhibits high purification performance.
（考案が解決しようとする問題点）
しかしながら、上述した従来の排気ガス浄化装
置においては、以下の問題点があつた。(Problems to be Solved by the Invention) However, the conventional exhaust gas purification device described above has the following problems.
すなわち、排ガス系路２に温度検知器７を介装
しかつ切替弁６を制御するコンピユータユニツト
８を新たに設けなければならないため、部品点数
が増加してコスト的負担が大きくなるという問題
点を有していた。 That is, it is necessary to install a temperature sensor 7 in the exhaust gas line 2 and to newly install a computer unit 8 for controlling the switching valve 6, which increases the number of parts and increases the cost burden. had.
また、上記実施例においては、切換弁６の切換
を排気ガスの温度により行なつているが、排気ガ
スの温度の変動と排気ガス中の被毒物質の濃度と
は必ずしも一致しておらず、このために温度によ
る切替制御では被毒物質が２つの触媒コンバータ
に均等に分配されないという問題点を有してい
た。 Furthermore, in the embodiment described above, the switching of the switching valve 6 is performed based on the temperature of the exhaust gas, but fluctuations in the temperature of the exhaust gas and the concentration of poisonous substances in the exhaust gas do not necessarily match. For this reason, switching control based on temperature has the problem that poisonous substances are not evenly distributed to the two catalytic converters.
本考案の目的は、空燃比フイードバツク制御装
置を利用して、コスト負担の可及的低減を図り、
かつ被毒物質の２つの触媒コンバータへの分配を
適当にして耐久性の一層の向上を図ることにあ
る。 The purpose of this invention is to reduce the cost burden as much as possible by using an air-fuel ratio feedback control device.
Another object of the present invention is to appropriately distribute poisonous substances to the two catalytic converters to further improve durability.
（問題点を解決するための手段）
上記目的を達成するために、本考案に係る自動
車用排気ガス浄化装置の特徴は、排気系路中に直
列に介装された２つの３元触媒コンバータと、排
気ガスに含まれる酸素濃度を検出して空燃比を制
御する空燃比フイードバツク制御装置とを備えた
排気ガス浄化装置において、前記排気系路に上流
側の触媒コンバータを迂回するバイパスを設ける
と共に、該バイパスの上流側分岐部に排気ガスの
流れを本道側とバイパス側とに切替える切替弁を
設け、かつ前記空燃比フイードバツク制御装置
に、該制御装置において求めた酸素濃度が所定値
を下回る場合に前記バイパスを開くように前記切
替弁を制御する弁制御部を設けるように構成した
ことにある。(Means for Solving the Problems) In order to achieve the above object, the automobile exhaust gas purification device according to the present invention is characterized by two three-way catalytic converters installed in series in the exhaust system. , an exhaust gas purification device comprising an air-fuel ratio feedback control device that detects the oxygen concentration contained in exhaust gas and controls the air-fuel ratio; A switching valve is provided at the upstream branch of the bypass to switch the flow of exhaust gas between the main road side and the bypass side, and the air-fuel ratio feedback control device is provided with a switching valve that switches the flow of exhaust gas between the main road side and the bypass side, and the air-fuel ratio feedback control device is provided with a switch valve that switches the flow of exhaust gas between the main road side and the bypass side, and the air-fuel ratio feedback control device is provided with The present invention is configured to include a valve control section that controls the switching valve so as to open the bypass.
（作用）
上記のように構成したので、既存の空燃比フイ
ードバツク制御装置の酸素濃度検出器をそのまゝ
用いてわずかの改良で切替弁を開閉制御できる。
しかも空燃比フイードバツク制御装置が作動する
条件下では、例えばアイドリング時や低速走行時
などのように空燃比が薄くつまり酸素濃度が高く
温度がそれほど高くない場合は上流側の触媒コン
バータを排気ガスが通過する一方、加速時などの
ように空燃比が濃い場合つまり酸素濃度が低い場
合はバイパス回路が開かれて下流側の触媒コンバ
ータを排気ガスが通過し、また始動時のように温
度が低くて空燃比フイードバツク制御装置が作動
しない条件下では、空燃比の濃い排気ガスが上流
側の触媒コンバータを通過することとなり、排気
ガス中の被毒物質が２つの触媒コンバータにほゞ
均等に分配されると共に、上流側の触媒コンバー
タが過熱することもなくなる。(Function) With the above configuration, the opening and closing of the switching valve can be controlled by using the oxygen concentration detector of the existing air-fuel ratio feedback control device as is and with slight modifications.
Moreover, under the conditions in which the air-fuel ratio feedback control device operates, for example when the air-fuel ratio is low, such as when idling or driving at low speeds, that is, the oxygen concentration is high and the temperature is not very high, the exhaust gas passes through the upstream catalytic converter. On the other hand, when the air-fuel ratio is high, such as during acceleration, that is, when the oxygen concentration is low, the bypass circuit is opened and the exhaust gas passes through the downstream catalytic converter, and when the temperature is low and the air is Under conditions where the fuel ratio feedback control device does not operate, exhaust gas with a high air-fuel ratio passes through the upstream catalytic converter, and the poisonous substances in the exhaust gas are distributed almost equally between the two catalytic converters. , the upstream catalytic converter will no longer overheat.
（実施例）
以下本考案に係る自動車用排気ガス浄化装置に
ついて実施例に従い詳細に説明する。(Example) The automobile exhaust gas purification device according to the present invention will be described in detail below according to an example.
第１図は本考案の第１実施例の概略を示す一部
断面図であり、第３図と同一符号を付したものは
同一又は相当する部材を示すものとする。 FIG. 1 is a partially sectional view schematically showing a first embodiment of the present invention, and the same reference numerals as in FIG. 3 indicate the same or corresponding members.
同図において、エンジン１には吸気マニホール
ド１ａと排気マニホールド１ｂとが接続され、排
気マニホールド１ｂには排気系路２が接続されて
いる。該排気系路２には直列式タンデム型触媒コ
ンバータ３，４が介挿されており、また、前記排
気系路２には排気上流側の触媒コンバータ３の上
流側から分岐して下流側で再び接続されるバイパ
ス５が設けられている。前記吸気マニホールド１
ａには、空燃比フイードバツク制御装置を構成す
るコンピユータ２０により制御される電磁弁１０
に導通する吸気管２１が連通されている。符号２
２は前記電磁弁１０に一端が導通する導通管であ
り、この導通管２２の他端はアクチユエータ２３
に連通している。このアクチユエータ２３にはリ
ンク棒２４が設けられており、このリンク棒２４
に一端が連結されたリンク棒２５の他端は、前記
排気系路２とバイパス５の上流側分岐部５ａに設
けられた切換弁６に連結されている。前記排気系
路２のバイパス５上流側分岐部５ａの下流側で、
かつ触媒コンバータ３の上流側には酸素濃度を検
知するO2センサ３０が取付けられており、この
O2センサ３０は前記コンピユータ２０に検出信
号を送出するように設定されている。尚、切替弁
６が触媒コンバータ３へ通じる本道を閉じた状態
でも、O2センサ３０による酸素濃度の検出に支
障がない程度に触媒コンバータ３側へわずか排気
ガスが流れるようになつている。また符号４０は
電磁弁１０によつて吸入される大気を濾過するフ
イルタであり、符号４１は電磁弁１０とフイルタ
４０との間の管路であり、また、符号４２は排気
系路２の下流側に設けられたマフラーである。 In the figure, an intake manifold 1a and an exhaust manifold 1b are connected to an engine 1, and an exhaust system path 2 is connected to the exhaust manifold 1b. Series tandem type catalytic converters 3 and 4 are inserted in the exhaust system path 2, and the exhaust system path 2 branches from the upstream side of the catalytic converter 3 on the upstream side of the exhaust gas and reconnects on the downstream side. A connected bypass 5 is provided. The intake manifold 1
A shows a solenoid valve 10 controlled by a computer 20 constituting an air-fuel ratio feedback control device.
An intake pipe 21 is connected to the intake pipe 21 . code 2
2 is a conduction pipe whose one end is connected to the electromagnetic valve 10, and the other end of this conduction pipe 22 is connected to the actuator 23.
is connected to. This actuator 23 is provided with a link rod 24, and this link rod 24
The other end of the link rod 25 is connected to a switching valve 6 provided at an upstream branch 5a of the exhaust system 2 and the bypass 5. On the downstream side of the bypass 5 upstream branch part 5a of the exhaust system path 2,
In addition, an O 2 sensor 30 is installed on the upstream side of the catalytic converter 3 to detect oxygen concentration.
The O 2 sensor 30 is set to send a detection signal to the computer 20. Note that even when the switching valve 6 closes the main path leading to the catalytic converter 3, a small amount of exhaust gas flows toward the catalytic converter 3 to the extent that detection of oxygen concentration by the O 2 sensor 30 is not hindered. Reference numeral 40 is a filter that filters the air taken in by the electromagnetic valve 10, reference numeral 41 is a pipe line between the electromagnetic valve 10 and the filter 40, and reference numeral 42 is a downstream of the exhaust system line 2. It is a muffler installed on the side.
上記のような構成において、本考案に係る排気
ガス浄化装置の動作について説明する。 In the above configuration, the operation of the exhaust gas purification device according to the present invention will be explained.
まず、通常の空燃比フイードバツク制御条件に
おいては、O2センサ３０が排気系路２内を流れ
る排気ガスの酸素濃度を検出する。すなわち、ア
イドリング時や低速走行時のように吸気マニホー
ルド１ａ内の空燃比が理論空燃比（14.4〜15.0）
より薄くて排気マニホールド１ｂ内の酸素濃度が
高くなり、O2センサ３０からの信号にもとづい
てコンピユータ２０が演算した空燃比が所定の値
より大きくなると、コンピユータ２０から電磁弁
１０を制御するための信号が送出される。この制
御信号により電磁弁１０はアクチユエータ２３に
連通する導通管２２と吸気管２１とを開通させ
る。この状態において、アクチユエータ２３はリ
ンク棒２４，２５により上流側分岐部５ａの切換
弁６の開閉位置をバイパス５閉鎖側とする。従つ
て排気ガスは第１図の矢印Ｘのように流れて触媒
コンバータ３に充填された触媒により浄化され
る。このフイードバツク条件の下では排気ガスの
温度は余り高くなく、被毒物質の含有濃度も余り
濃くないので、触媒コンバータ３の触媒は余り劣
化しない。さらに、触媒コンバータ３を通過した
排気ガスは、触媒コンバータ４を通過するので、
この排気ガスの通過により触媒コンバータ４の触
媒は暖機されている。 First, under normal air-fuel ratio feedback control conditions, the O 2 sensor 30 detects the oxygen concentration of the exhaust gas flowing in the exhaust system path 2 . That is, when idling or driving at low speed, the air-fuel ratio in the intake manifold 1a is the stoichiometric air-fuel ratio (14.4 to 15.0).
When the oxygen concentration in the exhaust manifold 1b increases and the air-fuel ratio calculated by the computer 20 based on the signal from the O 2 sensor 30 becomes larger than a predetermined value, the A signal is sent out. This control signal causes the solenoid valve 10 to open the intake pipe 21 and the conduction pipe 22 that communicates with the actuator 23 . In this state, the actuator 23 uses the link rods 24 and 25 to set the open/close position of the switching valve 6 of the upstream branch portion 5a to the bypass 5 closing side. Therefore, the exhaust gas flows as indicated by arrow X in FIG. 1 and is purified by the catalyst filled in the catalytic converter 3. Under this feedback condition, the temperature of the exhaust gas is not very high and the concentration of poisonous substances is not very high, so the catalyst of the catalytic converter 3 does not deteriorate much. Furthermore, since the exhaust gas that has passed through the catalytic converter 3 passes through the catalytic converter 4,
The catalyst of the catalytic converter 4 is warmed up by the passage of this exhaust gas.
次に同じ空燃比フイードバツク制御条件下で、
加速時などで空燃比が濃くなる場合には、排気系
路２内の排気ガスは高熱となり、また被毒物質も
高濃度となる。このとき、O2センサ３０からの
信号にもとづいてコンピユータ２０が演算した空
燃比が所定の値以上に小さくなると、コンピユー
タ２０は電磁弁１０を制御するための信号を送出
し、フイルタ４０の設けられた管路４１とアクチ
ユエータ２３の導通管２２とを開通させ、大気と
アクチユエータ２３とを導通する。これによつて
リンク棒２４，２５が駆動されて分岐部５ａの切
換弁６を作動させてバイパス５を開通させるモー
ドとする。従つて排気ガスは第１図の点線矢印方
向Ｙ方向すなわちバイパス５に迂回されて下流側
の触媒コンバータ４へ直接流れ、そこで浄化され
ると共に、該触媒コンバータ４には排気ガス中の
被毒物質が堆積することとなる。一方、始動時の
ように温度が低くて空燃比フイードバツク制御装
置が作動しない条件下では、空燃比の濃い排気ガ
スが上流側の触媒コンバータを通過することとな
り、触媒コンバータ３には排気ガス中の被毒物質
が堆積する。すなわち、排気ガス中の被毒物質は
２つの触媒コンバータ３，４にほゞ均等に分配さ
れると共に、上流側の触媒コンバータ３が過熱す
ることもなくなる。 Next, under the same air-fuel ratio feedback control conditions,
When the air-fuel ratio becomes rich during acceleration, the exhaust gas in the exhaust system 2 becomes hot and the poisonous substances become highly concentrated. At this time, when the air-fuel ratio calculated by the computer 20 based on the signal from the O2 sensor 30 becomes smaller than a predetermined value, the computer 20 sends a signal to control the solenoid valve 10, opens the pipe 41 with the filter 40 and the conductor pipe 22 of the actuator 23, and connects the atmosphere to the actuator 23. This drives the link rods 24 and 25 to operate the switching valve 6 of the branch 5a, and sets the mode to open the bypass 5. Therefore, the exhaust gas flows in the direction of the dotted arrow Y in FIG. 1, that is, is diverted to the bypass 5 and flows directly to the downstream catalytic converter 4, where it is purified and the poisonous substances in the exhaust gas accumulate in the catalytic converter 4. On the other hand, under conditions such as at start-up when the temperature is low and the air-fuel ratio feedback control device does not operate, exhaust gas with a rich air-fuel ratio passes through the upstream catalytic converter, and poisonous substances in the exhaust gas accumulate in the catalytic converter 3. In other words, the poisonous substances in the exhaust gas are distributed almost equally to the two catalytic converters 3, 4, and the upstream catalytic converter 3 does not overheat.
以上説明した実施例に特有の効果としては、空
燃比フイードバツク制御の制御時期を検出する
O2センサが多量の排気ガスに晒されないので、
その寿命が延長する。 As an effect specific to the embodiment described above, the control timing of air-fuel ratio feedback control is detected.
Since the O2 sensor is not exposed to large amounts of exhaust gas,
Its lifespan will be extended.
（考案の効果）
以上詳細に説明したように本考案に係る自動車
用排気ガス浄化装置によれば、以下のような効果
を奏する。(Effects of the Invention) As described above in detail, the automobile exhaust gas purification device according to the present invention provides the following effects.
まず、既存の空燃比フイードバツク制御装置の
わずかの改良で実現できるので、コスト負担を最
小限に抑えることができる。また排気ガス中の被
毒物質を２つの触媒コンバータにほゞ均等に分配
できると共に、上流側の触媒コンバータの過熱を
防止できるので、２つの触媒コンバータのうちの
一方の触媒が被毒物質や熱によつて極端に劣化す
ることがなくなり耐久性が大幅に向上する。 First, it can be realized by making slight improvements to the existing air-fuel ratio feedback control device, so the cost burden can be kept to a minimum. In addition, the poisonous substances in the exhaust gas can be distributed almost equally to the two catalytic converters, and the upstream catalytic converter can be prevented from overheating. This prevents extreme deterioration and greatly improves durability.
第１図は、本考案に係る自動車用排気ガス浄化
装置の第１実施例の全体を示す一部断面概略図で
あり、第２図は従来の排気ガス浄化装置の一例を
示す該略図である。
２……排気系路、３……上流側触媒（熱害部
材）、５……バイパス、５ａ……上流側分岐部、
６……切換弁、３０……O2センサ（酸素濃度検
出器＝熱害部材）。
FIG. 1 is a partially cross-sectional schematic diagram showing the whole of a first embodiment of an automobile exhaust gas purification device according to the present invention, and FIG. 2 is a schematic diagram showing an example of a conventional exhaust gas purification device. . 2... Exhaust system path, 3... Upstream catalyst (heat damage member), 5... Bypass, 5a... Upstream branch part,
6...Switching valve, 30...O 2 sensor (oxygen concentration detector = heat damage component).
Claims (1)
コンバータと、排気ガスに含まれる酸素濃度を検
出して空燃比を制御する空燃比フイードバツク制
御装置とを備えた排気ガス浄化装置において、前
記排気系路に上流側の触媒コンバータを迂回する
バイパスを設けると共に、該バイパスの上流側分
岐部に排気ガスの流れを本道側とバイパス側とに
切替える切替弁を設け、かつ前記空燃比フイード
バツク制御装置に、該制御装置において求めた酸
素濃度が所定値を下回る場合に前記バイパスを開
くように前記切替弁を制御する弁制御部を設けた
ことを特徴とする自動車用排気ガス浄化装置。 An exhaust gas purification device comprising two three-way catalytic converters installed in series in an exhaust system path and an air-fuel ratio feedback control device that detects the oxygen concentration contained in exhaust gas and controls the air-fuel ratio, A bypass is provided in the exhaust system passage to bypass an upstream catalytic converter, and a switching valve is provided at an upstream branch of the bypass to switch the flow of exhaust gas between a main road side and a bypass side, and the air-fuel ratio feedback control is performed. An exhaust gas purification device for an automobile, characterized in that the device is provided with a valve control section that controls the switching valve to open the bypass when the oxygen concentration determined by the control device is lower than a predetermined value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985012738U JPH0511294Y2 (en) | 1985-01-31 | 1985-01-31 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985012738U JPH0511294Y2 (en) | 1985-01-31 | 1985-01-31 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61130709U JPS61130709U (en) | 1986-08-15 |
| JPH0511294Y2 true JPH0511294Y2 (en) | 1993-03-19 |
Family
ID=30496087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1985012738U Expired - Lifetime JPH0511294Y2 (en) | 1985-01-31 | 1985-01-31 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0511294Y2 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5042904U (en) * | 1973-08-17 | 1975-04-30 | ||
| JPS538045U (en) * | 1976-07-05 | 1978-01-24 | ||
| JPS57210116A (en) * | 1981-06-19 | 1982-12-23 | Toyota Motor Corp | Exhaust gas purifier |
-
1985
- 1985-01-31 JP JP1985012738U patent/JPH0511294Y2/ja not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5042904U (en) * | 1973-08-17 | 1975-04-30 | ||
| JPS538045U (en) * | 1976-07-05 | 1978-01-24 | ||
| JPS57210116A (en) * | 1981-06-19 | 1982-12-23 | Toyota Motor Corp | Exhaust gas purifier |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61130709U (en) | 1986-08-15 |
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