JPH0472975B2 - - Google Patents
Info
- Publication number
- JPH0472975B2 JPH0472975B2 JP58197166A JP19716683A JPH0472975B2 JP H0472975 B2 JPH0472975 B2 JP H0472975B2 JP 58197166 A JP58197166 A JP 58197166A JP 19716683 A JP19716683 A JP 19716683A JP H0472975 B2 JPH0472975 B2 JP H0472975B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- air
- secondary air
- engine
- fuel ratio
- 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
- 239000003054 catalyst Substances 0.000 claims description 61
- 239000000446 fuel Substances 0.000 claims description 28
- 238000000746 purification Methods 0.000 claims description 17
- 238000011144 upstream manufacturing Methods 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 2
- 239000007789 gas Substances 0.000 description 14
- 230000006866 deterioration Effects 0.000 description 9
- 238000002485 combustion reaction Methods 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000032683 aging Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives
- F01N3/222—Control of additional air supply only, e.g. using by-passes or variable air pump drives using electric valves only
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N9/00—Electrical control of exhaust gas treating apparatus
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/20—Pc systems
- G05B2219/25—Pc structure of the system
- G05B2219/25428—Field device
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Exhaust Gas After Treatment (AREA)
Description
【発明の詳細な説明】
(産業上の利用分野)
この発明は、エンジンの排気通路に触媒を設け
て排気ガスを浄化するエンジンの排気浄化装置に
関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine exhaust purification device that purifies exhaust gas by providing a catalyst in an exhaust passage of the engine.
(従来技術)
上述の触媒は該触媒内での排気ガスの化学反応
を促進させるために、該触媒が活性化する高温に
維持する必要があり、従来例えば、触媒上流の排
気通路に二次空気を供給して排気ガスの燃焼を促
進せしめ、その燃焼熱により触媒の温度を高温化
するようにしているが、触媒は経年によつて劣化
するため、例えば、上述の二次空気の供給を上述
の経年劣化を見越して初期値から多く設定して供
給している。(Prior Art) In order to promote the chemical reaction of exhaust gas within the catalyst, the above-mentioned catalyst needs to be maintained at a high temperature that activates the catalyst. The catalyst is supplied with air to promote the combustion of exhaust gas, and the heat of combustion raises the temperature of the catalyst, but since the catalyst deteriorates over time, for example, the supply of secondary air described above is In anticipation of deterioration over time, we supply a higher initial value.
このため触媒の使用初期時に必要以上の浄化、
すなわち過剰燃焼を起したり、また触媒の温度を
必要以上に高温に維持しなければならないために
経年劣化をより早く生じさせる問題点を有する。 For this reason, at the beginning of the catalyst's use, more purification than necessary occurs.
That is, there are problems in that excessive combustion occurs, and that the temperature of the catalyst must be maintained at a higher temperature than necessary, which causes deterioration over time to occur more quickly.
また従来エンジンの高負荷時において触媒の排
気ガス導入側の排気ガス接触面積を大きくする触
媒装置があるが(例えば特開昭55−10018号広
報)、この装置の場合部分的に遮蔽するので、遮
蔽されない他の部分の劣化は前述の場合と同様に
早く生じる問題点を有している。 In addition, there is a conventional catalyst device that increases the exhaust gas contact area on the exhaust gas introduction side of the catalyst when the engine is under high load (for example, Japanese Patent Application Laid-open No. 10018/1983), but in the case of this device, it is partially shielded, so Deterioration of other parts that are not shielded has the same problem as the previous case, which occurs quickly.
(発明の目的)
この発明の目的は、触媒の経年劣化を抑制し、
有効な浄化率を長期に渡つて得られるエンジンの
排気浄化装置の提供にある。(Object of the invention) The object of the invention is to suppress aging deterioration of a catalyst,
An object of the present invention is to provide an engine exhaust purification device that can obtain an effective purification rate over a long period of time.
(発明の構成)
この発明は、エンジンの総運転時間が所定値以
上になつたとき、エンジンに供給する混合気の空
燃比を濃化するとともに、二次空気を増量するよ
うに制御するエンジンの排気浄化装置であること
を特徴とする。(Structure of the Invention) The present invention provides an engine control system that controls the air-fuel ratio of the air-fuel mixture supplied to the engine and increases the amount of secondary air when the total operating time of the engine exceeds a predetermined value. It is characterized by being an exhaust purification device.
(発明の効果)
この発明によれば、エンジンの総運転時間が所
定値になるまでは、必要最小限の二次空気を触媒
に供給することで、触媒により排気ガスが必要以
上に過剰燃焼するのを押え、すなわち触媒の熱負
荷を下げて早期の触媒劣化を防止し、エンジンの
総運転時間が所定値になれば、空燃比の濃化と二
次空気の増量によつて燃焼性を上げて、すなわち
熱負荷を高めることで触媒の耐久後の浄化率の低
下割合を小さくし得て、排気ガスの浄化を有効に
行なわせ、もつて長期の使用を得ることができ
る。(Effect of the invention) According to the invention, by supplying the minimum required amount of secondary air to the catalyst until the total operating time of the engine reaches a predetermined value, the exhaust gas is not burned excessively by the catalyst. In other words, the heat load on the catalyst is lowered to prevent early catalyst deterioration, and once the total operating time of the engine reaches a predetermined value, combustibility is increased by enriching the air-fuel ratio and increasing the amount of secondary air. In other words, by increasing the heat load, it is possible to reduce the rate of decrease in the purification rate of the catalyst after its durability, thereby making it possible to effectively purify exhaust gas and obtain long-term use.
(実施例)
この発明の一実施例を以下図面に基づいて詳述
する。(Example) An example of the present invention will be described in detail below based on the drawings.
図面はエンジンの排気浄化装置を示し、第1図
において、エンジン1はシリンダ2、ピストン
3、シリンダヘツド4を備え、シリンダヘツド4
には吸気通路5と排気通路6とが接続されてい
る。 The drawing shows an engine exhaust purification device. In FIG. 1, an engine 1 includes a cylinder 2, a piston 3, and a cylinder head 4.
An intake passage 5 and an exhaust passage 6 are connected to the intake passage 5 and the exhaust passage 6.
上述の吸気通路5の上流端には第1エアクリー
ナ7が設けられ、その下流には気化器8が配設さ
れ、れこの気化器8にはエンジン1に供給する混
合気の空燃比を調整するためのソレノイドバルブ
からなるアクチユエータ9が設けられ、このアク
チユエータ9は前述の排気通路6の上流側に設け
られて、排気ガス中の酸素濃度に対応した信号を
出力するO2センサ10の出力信号に基づいて空
燃比制御回路11により駆動制御される。 A first air cleaner 7 is provided at the upstream end of the above-mentioned intake passage 5, and a carburetor 8 is provided downstream thereof, and the carburetor 8 adjusts the air-fuel ratio of the air-fuel mixture supplied to the engine 1. An actuator 9 consisting of a solenoid valve is provided, and this actuator 9 is provided on the upstream side of the aforementioned exhaust passage 6, and is based on an output signal of an O2 sensor 10 that outputs a signal corresponding to the oxygen concentration in the exhaust gas. The drive is controlled by the air-fuel ratio control circuit 11.
前述の排気通路6の下流にはエンジン1の排気
ガスを浄化する三元触媒の触媒12が配設され、
この触媒12にはこの触媒12の温度を検出する
触媒温度センサ13が設けられている。 A three-way catalyst 12 for purifying exhaust gas from the engine 1 is disposed downstream of the exhaust passage 6 described above.
This catalyst 12 is provided with a catalyst temperature sensor 13 that detects the temperature of this catalyst 12.
上述の触媒12の上流側の排気通路6には、こ
の触媒12に二次空気を供給する二次空気供給通
路14が開口され、この通路14の上流端には第
2エアクリーナ15が設けられ、この下流にはエ
アポンプ16が配設されせ、このエアポンプ16
はモータ17によつて駆動される。 A secondary air supply passage 14 for supplying secondary air to the catalyst 12 is opened in the exhaust passage 6 on the upstream side of the catalyst 12, and a second air cleaner 15 is provided at the upstream end of this passage 14. An air pump 16 is disposed downstream of this, and this air pump 16
is driven by a motor 17.
上述のエアポンプ16の下流の通路14には分
岐通路18が形成され、この分岐通路18は前述
のO2センサ10の上流近傍の排気通路6に開口
され、分岐通路18の中間部には印加電圧に比例
して駆動し、通路18を開閉するリニヤソレノイ
ドバルブ19が設けられ、このバルブ19の開放
量に比例した二次空気をO2センサ10に供給し
て、空燃比をリツチに調整する。 A branch passage 18 is formed in the passage 14 downstream of the air pump 16 described above, and this branch passage 18 opens to the exhaust passage 6 near the upstream of the O2 sensor 10 described above. A linear solenoid valve 19 that is driven proportionally to open and close the passage 18 is provided, and secondary air proportional to the opening amount of the valve 19 is supplied to the O2 sensor 10 to richly adjust the air-fuel ratio.
前述のモータ17およびリニヤソレノイドバル
ブ19は二次空気制御回路20によつて制御さ
れ、この制御は前述の触媒温度センサ13、水温
センサ21、負圧センサ22、回転センサ23、
総走行距離センサ24とからの出力信号に基づい
て行なわれる。 The aforementioned motor 17 and linear solenoid valve 19 are controlled by a secondary air control circuit 20, and this control is performed by the aforementioned catalyst temperature sensor 13, water temperature sensor 21, negative pressure sensor 22, rotation sensor 23,
This is done based on the output signal from the total travel distance sensor 24.
上述の水温センサ21はエンジン11の冷却水
の温度を検知して水温信号を出力し、負圧センサ
22は吸気通路5の吸気負圧を検知して負圧信号
を出力し、回転センサ23はエンジン1のクラン
クシヤフト(図示省略)の回転を検知して回転信
号を出力し、総走行距離センサ24は自動車の総
走行距離を検知して総走行距離信号を出力する。 The above-mentioned water temperature sensor 21 detects the temperature of the cooling water of the engine 11 and outputs a water temperature signal, the negative pressure sensor 22 detects the intake negative pressure in the intake passage 5 and outputs a negative pressure signal, and the rotation sensor 23 detects the intake air negative pressure in the intake passage 5 and outputs a negative pressure signal. The rotation of the crankshaft (not shown) of the engine 1 is detected and a rotation signal is output, and the total mileage sensor 24 detects the total mileage of the automobile and outputs a total mileage signal.
第2図イはエンジン1の運転状態と二次空気の
供給量との関係を示す特性図であつて、領域A〜
Dはそれぞれ同量の二次空気供給を必要とする領
域を示し、その供給量は低負荷低回転領域では、
排気量の増加に対応して二次空気量も増加される
ことにより、触媒12の排気ガス浄化の作用を有
効化させると共に、高負荷高回転領域では、二次
空気量も少なくして触媒12の加熱を抑制して、
触媒12の耐久性を向上させるように領域A,
B,C,Dの順に二次空気の供給量が多くなつて
いる。 FIG. 2A is a characteristic diagram showing the relationship between the operating state of the engine 1 and the supply amount of secondary air, and is a characteristic diagram showing the relationship between the operating state of the engine 1 and the supply amount of secondary air.
D indicates the area that requires the same amount of secondary air supply, and the supply amount is as follows in the low load and low rotation area.
By increasing the amount of secondary air in accordance with the increase in displacement, the exhaust gas purifying action of the catalyst 12 is made effective, and in the high-load, high-speed region, the amount of secondary air is also reduced and the amount of secondary air is increased. By suppressing the heating of
Region A, so as to improve the durability of the catalyst 12;
The amount of secondary air supplied increases in the order of B, C, and D.
なお領域Eは二次空気の供給を停止する領域で
ある。そして各領域A〜Dにおける二次空気供給
量はエンジン1の運転状態に対応させて後述する
メモリのマツプに記憶されている。 Note that region E is a region where the supply of secondary air is stopped. The amount of secondary air supplied in each region A to D is stored in a map of the memory, which will be described later, in correspondence with the operating state of the engine 1.
第3図は前述の二次空気制御回路20の詳細を
示す。前述の触媒12は使用によつて経年劣化が
あるため、経年に対応して浄化率を高める必要が
ある。この浄化率を高めるには、触媒12での燃
焼を多くし触媒12を活性化することで可能とな
り、未燃焼の燃料を触媒12に多く供給すること
で行ない得る。 FIG. 3 shows details of the secondary air control circuit 20 described above. Since the aforementioned catalyst 12 deteriorates over time due to use, it is necessary to increase the purification rate over time. This purification rate can be increased by increasing combustion in the catalyst 12 and activating the catalyst 12, and by supplying a large amount of unburned fuel to the catalyst 12.
一方、触媒12の使用経年はエンジン1の総運
転時間に置き換えてみることができ、またこの総
運転時間は自動車の総走行距離に置き換えて見る
ことができる。 On the other hand, the age of the catalyst 12 can be replaced by the total operating time of the engine 1, and this total operating time can also be replaced by the total distance traveled by the vehicle.
メモリ25には総走行距離に対応して係数K2
がストアされ、この係数K2は触媒12の経年に
対応してこれに供給される燃料を増加させるもの
であり、第2図ハに示すように、初期では係数
K2は1であつて総走行距離が長くなるに比例し
て大きな値になるように設定されている。 The memory 25 stores a coefficient K2 corresponding to the total distance traveled.
is stored, and this coefficient K2 increases the fuel supplied to the catalyst 12 as it ages, and as shown in Figure 2 C, initially the coefficient K2 is
K2 is set to 1 and increases in proportion to the longer the total distance traveled.
係数演算回路26は総走行距離センサ24から
の出力信号に対応する係数K2をメモリ25から
読出し、印加電圧演算回路27は読出した係数
K2に基づいてリニヤソレノイドバルブ19を駆
動する印加電圧値を演算し、この印加電圧値によ
りリニヤソレノイドバルブ駆動回路28を介して
リニヤソレノイドバルブ19が駆動される。 The coefficient calculation circuit 26 reads out the coefficient K2 corresponding to the output signal from the total mileage sensor 24 from the memory 25, and the applied voltage calculation circuit 27 reads out the coefficient K2 corresponding to the output signal from the total mileage sensor 24.
An applied voltage value for driving the linear solenoid valve 19 is calculated based on K2, and the linear solenoid valve 19 is driven by this applied voltage value via the linear solenoid valve driving circuit 28.
上述のリニヤソレノイドバルブ19が駆動され
ると、前述した分岐通路18が触媒12の経年劣
化に対応して開放され、その開放量に対応した二
次空気が後述の制御でエアポンプ16が駆動され
ることでO2センサ10の上流側に供給される。 When the above-mentioned linear solenoid valve 19 is driven, the above-mentioned branch passage 18 is opened in response to aging of the catalyst 12, and the air pump 16 is driven by secondary air corresponding to the opening amount under the control described below. As a result, it is supplied to the upstream side of the O2 sensor 10.
上述のO2センサ10は二次空気が供給される
ことによつて上記二次空気が供給される以前の空
燃比に比べて空燃比がリーンであると検知するの
で、この検知信号が空燃比制御回路11に入力さ
れることによつて、この制御回路11は上記二次
空気が供給される以前の空燃比に比べて空燃比が
リツチになるように気化器8のアクチユエータ9
を制御する。 The above-mentioned O2 sensor 10 detects that the air-fuel ratio is leaner than the air-fuel ratio before the secondary air is supplied due to the supply of secondary air, so this detection signal is used to control the air-fuel ratio. By being input to the circuit 11, the control circuit 11 controls the actuator 9 of the carburetor 8 so that the air-fuel ratio becomes richer than the air-fuel ratio before the secondary air is supplied.
control.
その結果、排気ガス中には触媒12の経年劣化
に対応して未燃焼燃料が多く供給されることにな
る。 As a result, a large amount of unburned fuel is supplied to the exhaust gas as the catalyst 12 deteriorates over time.
二次空気供給のためのモータ17の駆動制御は
エンジン1の運転状態に対応して行なう。すなわ
ち、負圧センサ22からの吸気負圧信号と、回転
センサ23からのエンジン回転信号とによつて基
本制御信号発生回路29はエンジン1の運転状態
を判定する。 Drive control of the motor 17 for supplying secondary air is performed in accordance with the operating state of the engine 1. That is, the basic control signal generation circuit 29 determines the operating state of the engine 1 based on the intake negative pressure signal from the negative pressure sensor 22 and the engine rotation signal from the rotation sensor 23.
一方、マツプ30には前述の第2図イで示した
運転領域A〜Dに対応させて二次空気供給量が記
憶されており、上述の基本制御信号発生回路29
は判定した運転状態の二次空気供給量をマツプ3
0から読出し、読出した供給量に対応する制御信
号を発生する。 On the other hand, the secondary air supply amount is stored in the map 30 in correspondence with the operating ranges A to D shown in FIG.
Map 3 the secondary air supply amount in the determined operating state.
It reads out from 0 and generates a control signal corresponding to the read supply amount.
一方、エンジン1の温度が低いとき、マツプ3
0で設定された二次空気供給量の値で二次空気を
供給すると触媒12での燃焼性が低下して浄化率
が低下する。そのためにエンジン1の冷却水の温
度が設定温度t0以下では、水温が低くなるにした
がつて二次空気供給量が多くなるように係数K1
が設定され、この係数K1は第2図ロに示される
ように、設定温度t0以上では1、それ以下では水
温が低くなるに比例して多くなる値に設定されて
いる。 On the other hand, when the temperature of engine 1 is low, map 3
If secondary air is supplied with the value of the secondary air supply amount set to 0, the combustibility at the catalyst 12 will decrease and the purification rate will decrease. Therefore, when the temperature of the engine 1 cooling water is below the set temperature t0, the coefficient K1 is set so that the amount of secondary air supplied increases as the water temperature decreases.
As shown in FIG. 2B, this coefficient K1 is set to a value of 1 when the temperature is above the set temperature t0, and increases in proportion to the lower water temperature below it.
関数回路31は上述の係数K1を水温の関数と
して記憶し、水温センサ21からの水温信号に基
づいて係数K1に対応する制御信号を出力する。 The function circuit 31 stores the above-mentioned coefficient K1 as a function of water temperature, and outputs a control signal corresponding to the coefficient K1 based on the water temperature signal from the water temperature sensor 21.
演算回路32は前段の基本制御信号発生回路2
9で算出した二次空気の基本供給量に対応する制
御信号を関数回路31から出力される係数K1に
対応した補正信号に基づいてほ性し、この補正し
た制御信号でゲート回路33、駆動回路34を介
してモータ17が駆動制御される。 The arithmetic circuit 32 is the basic control signal generation circuit 2 at the previous stage.
A control signal corresponding to the basic supply amount of secondary air calculated in step 9 is determined based on a correction signal corresponding to the coefficient K1 outputted from the function circuit 31, and the gate circuit 33 and the drive circuit are controlled by this corrected control signal. The motor 17 is driven and controlled via 34.
モータ17がエンジン1の運転状態に対応して
駆動されることにより、アエポンプ16は必要量
の二次空気を二次空気供給通路14を介して触媒
12に供給し、触媒12はこの通路14から供給
される二次空気と、前述の分岐通路18から供給
される総走行距離りに対応した二次空気とによつ
て排気ガスを燃焼し浄化する。 By driving the motor 17 in accordance with the operating state of the engine 1, the air pump 16 supplies the necessary amount of secondary air to the catalyst 12 via the secondary air supply passage 14, and the catalyst 12 supplies the required amount of secondary air to the catalyst 12 from this passage 14. The exhaust gas is combusted and purified by the supplied secondary air and the secondary air corresponding to the total traveling distance supplied from the branch passage 18 described above.
触媒12は上述の燃焼が行なわれて温度が高く
なり過ぎると焼損するために、設定された温度以
上になると排気ガスの燃焼を一時停止させる必要
がある。 Since the catalyst 12 burns out if the temperature becomes too high due to the above-described combustion, it is necessary to temporarily stop combustion of exhaust gas when the temperature exceeds a set temperature.
設定電圧発生回路35は上述の設定温度に対応
する電圧を発生し、比較回路36はこの設定電圧
と触媒温度センサ13からの温度検知信号の電圧
とを比較し、触媒12の温度が設定された温度以
上になると比較回路36から信号が発せられて前
述のゲート回路33を閉じる。そのためモータ1
7は駆動されないので、二次空気は触媒12に供
給されないため、燃焼が停止され、触媒12によ
る排気ガスの過剰燃焼が防止され、触媒12の焼
損が防止される。 The set voltage generation circuit 35 generates a voltage corresponding to the above-mentioned set temperature, and the comparison circuit 36 compares this set voltage with the voltage of the temperature detection signal from the catalyst temperature sensor 13, so that the temperature of the catalyst 12 is set. When the temperature exceeds the temperature, a signal is generated from the comparator circuit 36 to close the gate circuit 33 described above. Therefore, motor 1
7 is not driven, and therefore secondary air is not supplied to the catalyst 12, combustion is stopped, excessive combustion of exhaust gas by the catalyst 12 is prevented, and burnout of the catalyst 12 is prevented.
このように構成される排気浄化装置は触媒12
の使用経年を自動車の総走行距離で検知し、使用
経年に比例した係数K2を初期値を1にして設定
し、経年に対応して空燃比を濃化するように空燃
比制御回路11を制御すると共に、分岐通路18
から供給される経年に対応した二次空気を、二次
空気供給通路14から供給される基本的な二次空
気に加えることによつて触媒12の経年劣化に対
処させている。 The exhaust purification device configured in this way has a catalyst 12.
The age of use is detected by the total mileage of the vehicle, a coefficient K2 proportional to the age of use is set to an initial value of 1, and the air-fuel ratio control circuit 11 is controlled to enrich the air-fuel ratio in accordance with the age. At the same time, the branch passage 18
The deterioration of the catalyst 12 over time is dealt with by adding the secondary air supplied from the secondary air supply passage 14 corresponding to the age of the catalyst 12 to the basic secondary air supplied from the secondary air supply passage 14.
このとき、マツプ30に格納される各運転領域
A〜Dの基本二次空気量は触媒12の経年劣化を
見越して設定する必要はなく必要最小限の量でよ
い。 At this time, the basic amount of secondary air for each of the operating ranges A to D stored in the map 30 does not need to be set in anticipation of aging deterioration of the catalyst 12, and may be set to the minimum necessary amount.
その結果、第4図に示すように、触媒12は初
期の浄化率を高く耐久後には低下するも、通常、
高い浄化率を必要最小限の浄化率に押えて浄化す
るために、矢印で示すように耐久後の浄化率の低
下を小さくし得、劣化の経年が長くなり、その寿
命が長くなる。 As a result, as shown in FIG. 4, the catalyst 12 has a high initial purification rate, although it decreases after durability.
In order to suppress the high purification rate to the minimum necessary purification rate, the decrease in the purification rate after durability can be reduced as shown by the arrow, and the deterioration will take longer over time, resulting in a longer service life.
なお、上述の実施例では触媒12の使用経年を
自動車の総走行距離で見ているが、エンジン1の
総運転時間を計時してもよい。 In the above-described embodiment, the age of the catalyst 12 is measured based on the total distance traveled by the vehicle, but the total operating time of the engine 1 may also be measured.
また、二次空気制御回路20はアナログコンピ
ユータにより構成したものを示したが、上記回路
20はデジタルコンピユータにより構成してもよ
い。 Furthermore, although the secondary air control circuit 20 has been shown to be configured using an analog computer, the circuit 20 may also be configured using a digital computer.
加えて、総走行距離が所定値以上のときには二
次空気供給通路から供給する二次空気を増量して
もよい。 In addition, when the total travel distance is equal to or greater than a predetermined value, the amount of secondary air supplied from the secondary air supply passage may be increased.
また、上記二次空気の増量率は、触媒が還元触
媒のときには燃料の増量率よりも小さく、三元触
媒のときには上記燃料の増量率と同等に、そして
酸化触媒のときには上記燃料の増量率より大きく
すれば、各々の触媒での反応を良好に保つことが
できる。 In addition, the increase rate of the secondary air is smaller than the fuel increase rate when the catalyst is a reduction catalyst, equal to the fuel increase rate when the catalyst is a three-way catalyst, and lower than the fuel increase rate when the catalyst is an oxidation catalyst. If it is made larger, the reaction in each catalyst can be maintained well.
この発明の構成と実施例との反応において、二
次空気供給装置は、二次空気供給通路14、第2
エアクリーナ15、エアポンプ16、モータ1
7、および二次空気制御回路20に対応し、エン
ジン総運転時間検知手段は総走行距離センサ2
4、に対応し、空燃比調整手段は気化器8および
アクチユエータ9に対応し、二次空気調整手段は
二次空気制御回路20で制御されるモータ17,
リニヤソレノイドバルブ19、およびモータ17
に駆動されるエアポンプ16に対応し制御回路
は、O2センサ10、空燃比制御回路11、メモ
リ25、係数演算回路26、印加電圧演算回路2
7、リニヤソレノイドバルブ駆動回路28に対応
する。 In the reaction between the structure and the embodiment of this invention, the secondary air supply device includes the secondary air supply passage 14, the second
Air cleaner 15, air pump 16, motor 1
7, and the secondary air control circuit 20, the engine total operating time detection means is the total mileage sensor 2.
4, the air-fuel ratio adjusting means corresponds to the carburetor 8 and the actuator 9, and the secondary air adjusting means corresponds to the motor 17, which is controlled by the secondary air control circuit 20.
Linear solenoid valve 19 and motor 17
The control circuit corresponding to the air pump 16 driven by
7. Corresponds to the linear solenoid valve drive circuit 28.
図面はこの発明の一実施例を示し、第1図はエ
ンジンの排気浄化装置の構成図。第2図イ,ロ,
ハはエンジン運転領域の二次空気供給量の特性、
係数K1,K2の特性を示す図。第3図は二次空気
制御回路のブロツク図。第4図は触媒の経年劣化
を示す図である。
1……エンジン、6……排気通路、10……
O2センサ、11……空燃比制御回路、12……
触媒、14……二次空気供給通路、16……エア
ポンプ、17……モータ、18……分岐通路、1
9……リニヤソレノイドバルブ、20……二次空
気制御回路、22……負圧センサ、23……回転
センサ、24……総走行距離センサ、26……係
数演算回路、29……基本制御信号発生回路、3
0……マツプ。
The drawings show an embodiment of the present invention, and FIG. 1 is a block diagram of an engine exhaust purification device. Figure 2 A, B,
C is the characteristic of the secondary air supply amount in the engine operating region,
A diagram showing the characteristics of coefficients K1 and K2. Figure 3 is a block diagram of the secondary air control circuit. FIG. 4 is a diagram showing aging deterioration of the catalyst. 1...Engine, 6...Exhaust passage, 10...
O2 sensor, 11... Air-fuel ratio control circuit, 12...
Catalyst, 14... Secondary air supply passage, 16... Air pump, 17... Motor, 18... Branch passage, 1
9... Linear solenoid valve, 20... Secondary air control circuit, 22... Negative pressure sensor, 23... Rotation sensor, 24... Total mileage sensor, 26... Coefficient calculation circuit, 29... Basic control signal Generation circuit, 3
0...Matsupu.
Claims (1)
浄化する触媒と、 上記触媒の上流の排気通路に二次空気を供給す
る二次空気供給装置と、 エンジンの総運転時間を検知するエンジン総運
転時間検知手段と、 エンジンに供給される混合気の空燃比を調整す
る空燃比調整手段と、 二次空気の空気量を調整する二次空気調整手段
と、 前記エンジン総運転時間検知手段の出力を受け
エンジンの総運転時間が所定値以上のとき混合気
の空燃比を濃化するように上記空燃比調整手段を
制御するとともに、二次空気を増量するように前
記二次空気調整手段を制御する制御手段とを備え
たことを特徴とするエンジンの排気浄化装置。[Claims] 1. A catalyst disposed in an exhaust passage of an engine to purify exhaust gas; a secondary air supply device supplying secondary air to the exhaust passage upstream of the catalyst; and a total operating time of the engine. a total engine operation time detection means for detecting the total engine operation time; an air-fuel ratio adjustment means for adjusting the air-fuel ratio of the air-fuel mixture supplied to the engine; a secondary air adjustment means for adjusting the amount of secondary air; In response to the output of the time detection means, when the total operating time of the engine exceeds a predetermined value, the air-fuel ratio adjustment means is controlled to enrich the air-fuel ratio of the air-fuel mixture, and the secondary air is controlled to increase the amount of secondary air. 1. An engine exhaust purification device comprising: a control means for controlling an air adjustment means.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58197166A JPS6088813A (en) | 1983-10-20 | 1983-10-20 | Exhaust purifying device for engine |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58197166A JPS6088813A (en) | 1983-10-20 | 1983-10-20 | Exhaust purifying device for engine |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6088813A JPS6088813A (en) | 1985-05-18 |
JPH0472975B2 true JPH0472975B2 (en) | 1992-11-19 |
Family
ID=16369877
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP58197166A Granted JPS6088813A (en) | 1983-10-20 | 1983-10-20 | Exhaust purifying device for engine |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6088813A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2555055B2 (en) * | 1987-03-13 | 1996-11-20 | 株式会社日立製作所 | Engine controller |
DE3841686C1 (en) * | 1988-12-10 | 1990-01-04 | Daimler-Benz Aktiengesellschaft, 7000 Stuttgart, De |
-
1983
- 1983-10-20 JP JP58197166A patent/JPS6088813A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS6088813A (en) | 1985-05-18 |
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