JPH0579320A - Internal combustion engine, operation thereof and automobile - Google Patents

Internal combustion engine, operation thereof and automobile

Info

Publication number
JPH0579320A
JPH0579320A JP3241671A JP24167191A JPH0579320A JP H0579320 A JPH0579320 A JP H0579320A JP 3241671 A JP3241671 A JP 3241671A JP 24167191 A JP24167191 A JP 24167191A JP H0579320 A JPH0579320 A JP H0579320A
Authority
JP
Japan
Prior art keywords
exhaust gas
catalyst
engine
fuel
internal combustion
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.)
Granted
Application number
JP3241671A
Other languages
Japanese (ja)
Other versions
JP2601072B2 (en
Inventor
Osamu Kuroda
黒田  修
Hisao Yamashita
寿生 山下
Akio Honchi
章夫 本地
Noriko Watanabe
紀子 渡辺
Toshio Ogawa
敏男 小川
Hiroshi Miyadera
博 宮寺
Takeshi Atago
武士 阿田子
Original Assignee
Hitachi Ltd
株式会社日立製作所
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 by Hitachi Ltd, 株式会社日立製作所 filed Critical Hitachi Ltd
Priority to JP3241671A priority Critical patent/JP2601072B2/en
Publication of JPH0579320A publication Critical patent/JPH0579320A/en
Priority claimed from US08/351,167 external-priority patent/US5577383A/en
Application granted granted Critical
Publication of JP2601072B2 publication Critical patent/JP2601072B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/18Exhaust 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
    • F01N3/22Control of additional air supply only, e.g. using by-passes or variable air pump drives
    • F01N3/222Control of additional air supply only, e.g. using by-passes or variable air pump drives using electric valves only
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/18Exhaust 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
    • F01N3/20Exhaust 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 specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/18Exhaust 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
    • F01N3/20Exhaust 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 specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2053By-passing catalytic reactors, e.g. to prevent overheating
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/18Exhaust 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
    • F01N3/22Control of additional air supply only, e.g. using by-passes or variable air pump drives
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/24Exhaust 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 constructional aspects of converting apparatus
    • F01N3/30Arrangements for supply of additional air
    • F01N3/32Arrangements for supply of additional air using air pump
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N9/00Electrical control of exhaust gas treating apparatus
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/021Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/024Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/021Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/024Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
    • F02D41/0255Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus to accelerate the warming-up of the exhaust gas treating apparatus at engine start
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/14Introducing closed-loop corrections
    • F02D41/1438Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1446Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being exhaust temperatures
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2390/00Arrangements for controlling or regulating exhaust apparatus
    • F01N2390/02Arrangements for controlling or regulating exhaust apparatus using electric components only
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2430/00Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
    • F01N2430/06Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics by varying fuel-air ratio, e.g. by enriching fuel-air mixture
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/12Improving ICE efficiencies
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/40Engine management systems

Abstract

PURPOSE:To effectively carry out purification of exhaust gas discharged especially immediately after starting in an internal combustion engine to purify engine exhaust gas by a catalyst. CONSTITUTION:An engine is operated by flowing exhaust gas through a pre- catalyst 2 provided near the engine and then a main catalyst 3 provided in its back stream in sequence and simultaneously in the state of excess fuel rather than a theoretical air fuel ratio until the main catalyst 3 raises its temperature up to the temperature to thoroughly display its function at. In this way, it is possible to function the pre-catalyst 2 at low temperature by way of burning the exhaust gas generated in the state of excess fuel by the pre-catalyst 2, heat the main catalyst 3 by way of using its combustion heat and heighten exhaust gas purifying performance.

Description

【発明の詳細な説明】Detailed Description of the Invention
【0001】[0001]
【産業上の利用分野】本発明は内燃機関に係り、特にエ
ンジンから排出される排気ガスの浄化手段を備えた内燃
機関に関する。本発明はまた排気ガス浄化性能を高める
ことができる内燃機関の運転方法及び排気ガス浄化手段
を備えた自動車に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine having means for purifying exhaust gas discharged from the engine. The present invention also relates to an automobile equipped with a method of operating an internal combustion engine and exhaust gas purifying means capable of enhancing exhaust gas purifying performance.
【0002】[0002]
【従来の技術】内燃機関から排出される排気ガスに含ま
れる一酸化炭素(CO)、炭化水素(HC)及び窒素酸
化物(NOx)等は大気汚染物質として人体に悪影響を
及ぼすほかに植物の発育を妨げる等の問題をもたらす。
2. Description of the Related Art Carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), etc. contained in exhaust gas discharged from an internal combustion engine adversely affect the human body as air pollutants, and are also harmful to plants. It causes problems such as hindering growth.
【0003】そこで、従来より、これらの排出量低減に
は多大の努力が払われ、内燃機関の構造や燃焼条件など
の改良を通じて生成量を低減する方法、或は内燃機関か
ら排出された排気ガスを触媒等で浄化する後処理方法の
両面から技術開発が進められてきた。
Therefore, much effort has been made in the past to reduce the amount of these emissions, and a method of reducing the amount produced by improving the structure and combustion conditions of the internal combustion engine or the exhaust gas emitted from the internal combustion engine. Technological development has been promoted from both sides of a post-treatment method for purifying methane with a catalyst or the like.
【0004】このうち触媒方式は、エンジン排気ガスの
流路に排気ガス浄化触媒を設けて一酸化炭素(CO)、
炭化水素(HC)及び窒素酸化物(NOx)等の有害ガ
スを酸化或は還元するものである。触媒方式の従来技術
の一例として特開昭48−58215 号公報には、エンジン排
気ガス流路のエンジンになるべく近い位置に第1触媒を
設けその後段に第2触媒を設けてエンジン起動当初の触
媒温度が低いときの排気ガス浄化性能を高めることが示
されている。
Of these, the catalyst type is a carbon monoxide (CO) catalyst provided with an exhaust gas purification catalyst in the engine exhaust gas flow path.
It oxidizes or reduces harmful gases such as hydrocarbons (HC) and nitrogen oxides (NOx). As an example of a conventional catalyst system, Japanese Patent Laid-Open No. 48582/1988 discloses a catalyst at the beginning of engine startup by providing a first catalyst at a position as close as possible to an engine in an engine exhaust gas flow passage and a second catalyst at a subsequent stage. It has been shown to enhance exhaust gas purification performance at low temperatures.
【0005】触媒は所定値以上の温度に高められてはじ
めて高い活性を示すようになる。この温度は通常250
〜400℃といわれており、例えば特開昭54−16018 号
公報に記載されている。エンジンの起動当初は排気ガス
の温度が低く、低温の排気ガスが触媒に導かれることに
なり、触媒の機能を十分に引き出すことができない。前
記従来技術は、エンジン起動当初の触媒温度が低いとき
の排気ガス浄化性能を高める方法を開示している。
The catalyst becomes highly active only when it is heated to a temperature higher than a predetermined value. This temperature is usually 250
It is said that the temperature is up to 400 ° C, and it is described in, for example, JP-A-54-16018. When the engine is started, the temperature of the exhaust gas is low and the low-temperature exhaust gas is guided to the catalyst, so that the function of the catalyst cannot be fully brought out. The above-mentioned prior art discloses a method of enhancing exhaust gas purification performance when the catalyst temperature at the beginning of engine startup is low.
【0006】[0006]
【発明が解決しようとする課題】内燃機関のエンジンを
排気ガスの温度は、エンジン起動後次第に上昇していく
が、触媒が有効に機能する温度に上昇するまでには、お
よそ2分或はそれ以上かかる。一説には3〜5分かかる
という説もあり、特開昭54−79319 号公報に示されてい
る。エンジン起動時から触媒が活性を示す温度に高まる
までの間の排気ガスの浄化性能をいかに高めるかが、触
媒方式の成否を決することになる。
The temperature of the exhaust gas from the engine of the internal combustion engine gradually rises after the engine is started, but it takes about 2 minutes or more before the temperature rises to a temperature at which the catalyst functions effectively. It takes more. One theory is that it takes 3 to 5 minutes, which is disclosed in JP-A-54-79319. The success or failure of the catalytic system depends on how to improve the exhaust gas purification performance from the time when the engine is started to the time when the temperature of the catalyst becomes active.
【0007】本発明の目的は、エンジン起動直後に排出
される燃料未燃分及び部分燃焼成分の触媒による浄化性
能を高めた内燃機関及びエンジン起動方法を提供するに
ある。
An object of the present invention is to provide an internal combustion engine and an engine starting method in which the performance of purifying unburned fuel components and partial combustion components discharged immediately after engine startup by a catalyst is improved.
【0008】[0008]
【課題を解決するための手段】本発明は、エンジンの吸
気系に燃料と空気の量を制御する燃料・空気制御部を有
し排気系に燃焼触媒よりなる前触媒と排気ガス浄化主触
媒とを有する内燃機関において、前記エンジンを始動し
てから前記排気ガス浄化触媒の温度が活性を示す温度に
昇温するまでの間理論空燃比よりも燃料過剰となるよう
に前記燃料・空気制御部を操作する手段を備えたもので
ある。
SUMMARY OF THE INVENTION The present invention has a pre-catalyst and an exhaust gas purifying main catalyst, each of which has a fuel / air control unit for controlling the amount of fuel and air in an intake system of an engine and has a combustion catalyst in an exhaust system. In the internal combustion engine having, the fuel / air control unit is configured such that fuel exceeds the stoichiometric air-fuel ratio from the time the engine is started until the temperature of the exhaust gas purification catalyst rises to a temperature at which the catalyst activates. It is provided with a means for operating.
【0009】エンジン排気ガスの成分はエンジンの操作
条件、特に空燃比により変化し、エンジンを理論空燃比
よりも燃料過剰の状態で操作すると、一酸化炭素が多く
発生し、炭化水素も比較的多量に発生するようになる。
ここで注目すべきことは、空燃比が理論値より小さい場
合すなわち燃料過剰の場合には、排ガス中にHCの濃度
をはるかにしのぐ数%から10数%の多量のCOが含ま
れることである。COはHCよりかなり低い温度で触媒
燃焼させることができる。
The components of the engine exhaust gas change depending on the engine operating conditions, particularly the air-fuel ratio, and when the engine is operated with a fuel excess of the stoichiometric air-fuel ratio, a large amount of carbon monoxide is generated and a relatively large amount of hydrocarbons are also produced. Will occur.
What should be noted here is that when the air-fuel ratio is smaller than the theoretical value, that is, when the fuel is excessive, the exhaust gas contains a large amount of CO of several% to several tens of%, which far exceeds the concentration of HC. .. CO can be catalytically burned at much lower temperatures than HC.
【0010】本発明においては、COの触媒燃焼による
発熱を触媒及び排気ガスの昇温に利用する。しかしHC
の濃度はCOに比べて低いもののHCの単位重量当りの
発熱量はCOの5倍程度と大きい。従って、COの低温
触媒燃焼に引き続きHCの触媒燃焼が加われば、触媒及
び排気ガスを急速に昇温することができる。エンジンを
理論空燃比よりも燃料過剰の状態で操作することは、理
論空燃比で操作する場合に較べてCOとHCを多量に発
生することになるので触媒及び排気ガスを急速に昇温す
るのに望ましい。
In the present invention, the heat generated by the catalytic combustion of CO is used to raise the temperature of the catalyst and exhaust gas. But HC
Although the concentration of is lower than that of CO, the calorific value of HC per unit weight is as large as about 5 times that of CO. Therefore, if the low temperature catalytic combustion of CO is followed by the catalytic combustion of HC, the temperature of the catalyst and the exhaust gas can be rapidly raised. Operating the engine in a fuel excess of the stoichiometric air-fuel ratio will generate a large amount of CO and HC as compared with the case of operating at the stoichiometric air-fuel ratio, so the temperature of the catalyst and exhaust gas will rise rapidly. Desirable for.
【0011】エンジンを理論空燃比よりも燃料過剰の状
態で操作しつづけることは、燃費の面からすると好まし
くない。また、触媒の温度が高くなりすぎ耐熱性の面か
らも問題がある。そこで、触媒の温度が上昇したならば
理論空燃比でのエンジン操作に切り替えることが望まし
い。
From the viewpoint of fuel consumption, it is not preferable to continue operating the engine in a state in which the fuel is in excess of the stoichiometric air-fuel ratio. Further, the temperature of the catalyst becomes too high, and there is a problem in terms of heat resistance. Therefore, if the catalyst temperature rises, it is desirable to switch to engine operation at the stoichiometric air-fuel ratio.
【0012】本発明において、内燃機関とはシリンダ内
で燃料を爆発燃焼させ、そのエネルギーによって流体エ
ネルギーを機械的エネルギーに変換する装置を意味す
る。本発明は、内燃機関を動力源として運転される内燃
動車例えばガソリンカー、ディ−ゼルカーなどに適用す
るのに好適である。
In the present invention, the internal combustion engine means a device that explodes and burns fuel in a cylinder and converts fluid energy into mechanical energy by the energy. INDUSTRIAL APPLICABILITY The present invention is suitable for application to an internal combustion vehicle that is driven by an internal combustion engine as a power source, such as a gasoline car and a diesel car.
【0013】本発明は、以下の各構成を採ることにより
達成することができる。
The present invention can be achieved by adopting the following configurations.
【0014】(i)エンジンの吸気系に燃料と空気の量
を制御する燃料・空気制御部を有し排気系に燃焼触媒よ
りなる前触媒と排気ガス浄化主触媒とを有する内燃機関
において、前記排気ガス浄化主触媒の温度を検出する手
段と、前記エンジンを始動してから該排気ガス浄化主触
媒の検出温度が活性を示す温度になるまでの間理論空燃
比よりも燃料過剰となるように前記燃料・空気制御部を
操作する手段を備える。前記排気ガス浄化主触媒の温度
を検出する手段を設け、該温度検出手段の検出値に基づ
いて理論空燃比よりも燃料過剰の状態でエンジンを駆動
する時間を制御することが望ましい。
(I) In an internal combustion engine having a fuel / air control unit for controlling the amount of fuel and air in the intake system of the engine, and a pre-catalyst consisting of a combustion catalyst and an exhaust gas purifying main catalyst in the exhaust system, A means for detecting the temperature of the exhaust gas purifying main catalyst, and a means for making the fuel excess of the stoichiometric air-fuel ratio from the time when the engine is started until the detected temperature of the exhaust gas purifying main catalyst reaches a temperature at which it is active. A means for operating the fuel / air control unit is provided. It is desirable to provide means for detecting the temperature of the exhaust gas purifying main catalyst, and to control the time for driving the engine in a state where the fuel is in excess of the stoichiometric air-fuel ratio based on the detection value of the temperature detecting means.
【0015】エンジンを始動してから前記排気ガス浄化
主触媒の温度が活性を示す温度になるまでの間は理論空
燃比よりも燃料過剰とし、前記排気ガス浄化主触媒の温
度が活性を示す温度になったならば理論空燃比となるよ
うに前記燃料・空気制御部を切り替え操作することが望
ましい。
From the time when the engine is started until the temperature of the exhaust gas purifying main catalyst reaches a temperature at which it is active, the fuel is in excess of the stoichiometric air-fuel ratio, and the temperature of the exhaust gas purifying main catalyst is at a temperature at which it is active. If so, it is desirable to switch the fuel / air control unit so that the stoichiometric air-fuel ratio is achieved.
【0016】燃料過剰状態での空燃比A/F(Aは空気
重量、Fは燃料重量)は13以下,10以上とすること
が望ましい。また、エンジン排ガスのCO濃度が3%以
上,14%以下となる条件で燃料を過剰供給することが
望ましい。
The air-fuel ratio A / F (A is air weight, F is fuel weight) in an excess fuel state is preferably 13 or less and 10 or more. Further, it is desirable to excessively supply the fuel under the condition that the CO concentration of the engine exhaust gas is 3% or more and 14% or less.
【0017】理論空燃比は、触媒上で効果的にHCとC
Oの酸化とNOの還元を行わせるため空燃比のことであ
り、一般にはA/F=14.7 或はそれに近い値が選定
される。
The stoichiometric air-fuel ratio is such that HC and C are effectively
The air-fuel ratio is used to oxidize O and reduce NO. Generally, A / F = 14.7 or a value close to it is selected.
【0018】(ii)エンジンの排気ガス流路に燃焼触媒
よりなる前触媒及び排気ガス浄化主触媒を有する内燃機
関において、前記エンジンを理論空燃比よりも燃料過剰
の状態で起動し該燃料過剰の状態を前記排気ガス浄化主
触媒が活性を示す温度になるまで持続する手段を備え
る。
(Ii) In an internal combustion engine having a pre-catalyst consisting of a combustion catalyst and an exhaust gas purifying main catalyst in the exhaust gas flow path of the engine, the engine is started in a state of excess fuel over the stoichiometric air-fuel ratio Means for maintaining the state until the temperature at which the exhaust gas purifying main catalyst shows activity is provided.
【0019】本発明においては、例えば自動車の床下に
排気ガス浄化主触媒を設け、エンジンになるべく近い位
置に燃焼触媒よりなる前触媒を設けることが望ましい。
エンジン排気ガスの温度は排気ガス流路を流れる過程で
低下する。エンジンになるべく近い位置に前触媒を備え
ることにより排気ガス温度が低下しないうちに触媒に導
くことができる。また、前触媒を燃焼触媒とすることに
より、CO及びHCの酸化活性を高めることができる。
In the present invention, for example, it is desirable to provide an exhaust gas purifying main catalyst under the floor of an automobile and a pre-catalyst comprising a combustion catalyst as close to the engine as possible.
The temperature of engine exhaust gas decreases as it flows through the exhaust gas flow path. By providing the precatalyst at a position as close to the engine as possible, it is possible to guide the exhaust gas to the catalyst before the temperature decreases. Further, by using the combustion catalyst as the pre-catalyst, the oxidizing activity of CO and HC can be increased.
【0020】前触媒の上流側排気ガス流路には酸化剤例
えば空気を添加する手段を設けることが望ましい。
It is desirable to provide a means for adding an oxidant such as air in the exhaust gas passage on the upstream side of the front catalyst.
【0021】燃料過剰条件で燃焼し生成した排気ガス中
の酸素は一般に低濃度である。そこで、前触媒の前段に
空気等の酸素含有ガスを添加することにより前触媒にお
けるCO,HCの燃焼を効果的に行わせる。
Oxygen in the exhaust gas produced by combustion under the excessive fuel condition generally has a low concentration. Therefore, by adding an oxygen-containing gas such as air to the front stage of the front catalyst, CO and HC in the front catalyst can be effectively burned.
【0022】空気(酸素)の添加量としては排気ガスの
理論酸素消費量と当量か当量より過剰とすることが望ま
しい。この場合、前触媒における燃焼と主触媒における
排ガス浄化をともに良好に行うことができる。
The amount of air (oxygen) added is preferably equivalent to or more than the theoretical oxygen consumption of exhaust gas. In this case, both combustion in the front catalyst and purification of exhaust gas in the main catalyst can be favorably performed.
【0023】前触媒には、COの酸化とHCの酸化に共
に活性を有する燃焼触媒を用いることが望ましい。具体
的には、触媒活性成分として、周期律表の第VIII族,Ib
族,希土類金属,亜鉛及び錫から選ばれた金属あるいは
酸化物の少なくとも1種をもちいることが望ましい。
As the pre-catalyst, it is desirable to use a combustion catalyst which is active in both CO oxidation and HC oxidation. Specifically, as a catalytically active component, Group VIII, Ib of the periodic table is used.
It is desirable to use at least one metal or oxide selected from the group consisting of rare earth metals, zinc and tin.
【0024】排気ガス浄化主触媒としては、COとHC
酸化とNOxの還元に共に活性を示す三元触媒を用いる
ことが望ましい。
As the main catalyst for purifying exhaust gas, CO and HC are used.
It is desirable to use a three-way catalyst that is active in both oxidation and reduction of NOx.
【0025】前触媒の支持体としてコージェライト,ム
ライト,アルミニウムチタネイト等のいわゆるセラミッ
クスハニカムを用い、これに前述の触媒活性成分を担持
するか、或は支持体としてのセラミックスハニカムにシ
リカ,アルミナ,チタニア等の多孔質坦体を添着し、さ
らに前述の触媒活性成分を担持することが望ましい。本
発明においては、前触媒の触媒燃焼により発生した熱を
有効に利用して前触媒自身を急速に加熱し活性化するこ
とが肝要である。これは触媒担体や支持体の熱伝達率を
小さくして触媒と担体あるいは支持体との間の温度勾配
を大きくすることにより達成できる。上記したセラミッ
クスの熱伝達率は小さく触媒の温度を急速に上昇させる
のに有効に機能する。
A so-called ceramic honeycomb made of cordierite, mullite, aluminum titanate or the like is used as a support for the precatalyst, and the above-mentioned catalytically active component is supported on this, or silica, alumina, It is desirable to attach a porous carrier such as titania and further carry the above-mentioned catalytically active component. In the present invention, it is essential that the heat generated by catalytic combustion of the precatalyst be effectively utilized to rapidly heat and activate the precatalyst itself. This can be achieved by reducing the heat transfer coefficient of the catalyst carrier or support and increasing the temperature gradient between the catalyst and the carrier or support. The ceramics described above have a small heat transfer coefficient and effectively function to rapidly raise the temperature of the catalyst.
【0026】前触媒の支持体としては、ステンレス等の
導電性の金属あるいは合金のハニカムを用いることがで
きる。
As the support of the precatalyst, a honeycomb of a conductive metal or alloy such as stainless steel can be used.
【0027】触媒を急速に加熱することは触媒担体ある
いは支持体の比熱を小さくすることによってもまた達成
できる。ステンレス等の金属からなるハニカムを触媒の
支持体として使用することにより材料そのものの比熱が
小さくなるに加え材料の薄板化が可能となり、その結
果、熱容量を小さくでき、急速な昇温が可能となる。
Rapid heating of the catalyst can also be achieved by reducing the specific heat of the catalyst support or support. By using a honeycomb made of metal such as stainless steel as a support for the catalyst, the specific heat of the material itself can be reduced and the material can be thinned, resulting in a smaller heat capacity and rapid temperature rise. ..
【0028】前触媒に通電し触媒を加熱することも望ま
しいことである。
It is also desirable to energize the precatalyst to heat it.
【0029】金属の触媒担体あるいは支持体に通電しジ
ュール熱により加熱することにより前触媒の昇温を早め
ることができる。また、前触媒の昇温開始時に通電して
COの着火を促進することにより昇温を早めることがで
きる。
The temperature of the precatalyst can be accelerated by heating the metal catalyst carrier or support with Joule heat. Further, the temperature rise can be accelerated by energizing the precatalyst at the start of temperature rise to accelerate the ignition of CO.
【0030】(iii)内燃機関エンジンの吸気系に理論空
燃比よりも過剰の燃料を供給する手段を備え、前記エン
ジンの排気系に該燃料過剰供給によって生成した排気ガ
ス中の可燃成分を接触燃焼する燃焼触媒を備える。
(Iii) A means for supplying an excess amount of fuel to the intake system of the internal combustion engine is supplied to the exhaust system of the engine, and a combustible component in the exhaust gas generated by the excess supply of the fuel is catalytically burned to the exhaust system of the engine. A combustion catalyst is provided.
【0031】これによって、エンジン排気ガスとしてC
O及びHCを主として排出する内燃機関とすることがで
きる。
As a result, C is used as engine exhaust gas.
It can be an internal combustion engine that mainly emits O and HC.
【0032】(iv)理論空燃比の燃料と空気をエンジン
に供給して駆動し排気ガスを排気ガス浄化触媒によって
浄化するようにした内燃機関の運転方法において、前記
エンジンの起動時から少なくとも前記排気ガス浄化触媒
が活性を示す温度に昇温するまでの間前記エンジンを理
論空燃比よりも燃料過剰の状態で駆動し、生成した排気
ガス中の可燃成分を燃焼触媒により接触燃焼してから前
記排気ガス浄化触媒に送るようにする。
(Iv) In a method of operating an internal combustion engine in which fuel and air having a stoichiometric air-fuel ratio are supplied to an engine to drive the engine and exhaust gas is purified by an exhaust gas purifying catalyst, at least the exhaust gas is discharged after starting the engine. Until the temperature of the gas purifying catalyst rises to a temperature at which it is active, the engine is driven in a fuel excess state than the stoichiometric air-fuel ratio, and the combustible components in the generated exhaust gas are catalytically combusted by a combustion catalyst before the exhaust gas is exhausted. Send it to the gas purification catalyst.
【0033】(v)理論空燃比よりも燃料過剰の状態で
エンジンを駆動し、生成した排気ガスを燃焼触媒によっ
て接触燃焼してから系外に排出するように内燃機関を運
転する。
(V) The engine is driven in a state where the fuel is in excess of the stoichiometric air-fuel ratio, and the internal combustion engine is operated so that the generated exhaust gas is catalytically burned by the combustion catalyst and then discharged to the outside of the system.
【0034】(vi)理論空燃比よりも燃料過剰の状態で
エンジンを始動してその排気ガスを燃焼触媒よって接触
燃焼してから排気ガス浄化触媒に送り、該排気ガス浄化
触媒の温度が活性を示す温度まで昇温したならば燃料過
剰供給を停止しその排気ガスを直接前記排気ガス浄化触
媒に送るように内燃機関を運転する。
(Vi) The engine is started in a state where the fuel is in excess of the stoichiometric air-fuel ratio, the exhaust gas is catalytically burned by the combustion catalyst and then sent to the exhaust gas purification catalyst, and the temperature of the exhaust gas purification catalyst activates. When the temperature rises to the indicated temperature, the excess fuel supply is stopped and the internal combustion engine is operated so as to send the exhaust gas directly to the exhaust gas purification catalyst.
【0035】(vii)内燃機関を動力源として運転する内
燃動車において、前記内燃機関エンジンの排気ガス流路
に排気ガス浄化触媒を備え、前記エンジンを始動してか
ら排気ガスの温度が該排気ガス浄化触媒が活性を示す温
度に昇温するまでの間前記エンジンに理論空燃比よりも
過剰の燃料を供給する手段を備え、該燃料過剰状態での
エンジン駆動によって排出された排気ガスを接触燃焼す
る燃焼触媒を前記排気ガス流路の前記排気ガス浄化触媒
の上流側に備える。
(Vii) In an internal combustion vehicle that operates using an internal combustion engine as a power source, an exhaust gas purifying catalyst is provided in an exhaust gas flow path of the internal combustion engine, and the temperature of the exhaust gas after the engine is started is the exhaust gas. Means for supplying fuel to the engine in excess of the stoichiometric air-fuel ratio until the temperature of the purifying catalyst rises to a temperature at which it is active, and catalytically burns the exhaust gas discharged by engine driving in the excess fuel state. A combustion catalyst is provided on the upstream side of the exhaust gas purifying catalyst in the exhaust gas passage.
【0036】この具体例は自動車であり、例えばガソリ
ンカー或はディーゼルカーがある。 (viii)エンジンから排気ガス浄化主触媒に至る排気ガ
スの流路にバイパス流路を備え、該バイパス流路に燃焼
触媒よりなる前触媒を備える。
An example of this is an automobile, such as a gasoline car or a diesel car. (Viii) A bypass passage is provided in the exhaust gas passage from the engine to the exhaust gas purifying main catalyst, and a pre-catalyst made of a combustion catalyst is provided in the bypass passage.
【0037】前触媒は起動直後の短時間(大略2分程
度)機能すればあとは本質的には不要となる。不要とな
った後も、排ガスを流通することはいたずらに圧力損失
を増加させることになる。また、前触媒を長時間高温に
さらすことは触媒劣化の原因を持ち込むこととなる。エ
ンジンから主触媒に至る排ガスの流路にバイパスを設
け、バイパス内に前触媒を設け、エンジン起動直後で主
触媒が作動温度に達していない間のみ燃料過剰の燃焼を
行い、その排気ガスをバイパスの前触媒を経て主触媒に
導くことによりこれらの問題を排除することができる。
If the pre-catalyst functions for a short time (approximately 2 minutes) immediately after starting, it becomes essentially unnecessary afterwards. Even after it becomes unnecessary, circulating the exhaust gas unnecessarily increases the pressure loss. Further, exposing the pre-catalyst to a high temperature for a long time brings in a cause of catalyst deterioration. A bypass is installed in the exhaust gas flow path from the engine to the main catalyst, and a pre-catalyst is installed in the bypass to burn excess fuel only while the main catalyst does not reach the operating temperature immediately after engine startup, and the exhaust gas is bypassed. These problems can be eliminated by introducing the precatalyst to the main catalyst.
【0038】また、エンジンと前触媒の間の排ガス流路
に除湿手段好ましくは冷却除湿器を備えることは望まし
いことである。前触媒の温度が排ガスの露点以下の場
合、該除湿手段で排ガスを除湿し、例えば前触媒温度と
同等かもしくはそれ以下に冷却除湿し、その後、前触媒
に供給することが望ましい。
It is also desirable to provide a dehumidifying means, preferably a cooling dehumidifier, in the exhaust gas passage between the engine and the front catalyst. When the temperature of the precatalyst is equal to or lower than the dew point of the exhaust gas, it is desirable to dehumidify the exhaust gas by the dehumidifying means, cool and dehumidify the temperature to, for example, equal to or lower than the precatalyst temperature, and then supply the precatalyst.
【0039】エンジン排気ガスには通常多量の水蒸気が
含まれる。水蒸気を含む排ガスが前触媒に供給され前触
媒温度が低い場合、正確には前触媒の温度が排ガスの露
点以下の場合には、排気ガス中の水分は触媒上もしくは
触媒細孔内に凝縮する。この現象は触媒の性能を低下さ
せるのみならず触媒劣化の原因となり、また圧力損失を
増加させることにもなる。更に、一度凝縮が起こるとこ
れを蒸発させるには蒸発潜熱が必要となるため100℃
以上に昇温するには多量の熱量が必要となり、したがっ
て時間を要することともなる。排気ガスを除湿し、例え
ば前触媒温度と同等かもしくはそれ以下に冷却除湿し、
その後に前触媒に供給することにより、前触媒部での水
蒸気の凝縮を防止でき、それに伴う障害を回避すること
ができる。(vii)前記(iii)において、エンジンから
主触媒に至る排気ガスの流路にバイパスを流路設け、バ
イパス流路に排ガス除湿手段を設け、前触媒の温度が燃
焼排ガスの露点以下の場合にバイパスの除湿手段により
排気ガスを除湿した後主触媒に導き、前触媒の温度が排
ガスの露点以上の場合に排気ガスを直接前触媒へ導く。
Engine exhaust gas usually contains a large amount of water vapor. When the exhaust gas containing water vapor is supplied to the pre-catalyst and the pre-catalyst temperature is low, to be precise, when the temperature of the pre-catalyst is below the dew point of the exhaust gas, the water in the exhaust gas is condensed on the catalyst or in the catalyst pores. .. This phenomenon not only deteriorates the performance of the catalyst but also causes deterioration of the catalyst, and also increases the pressure loss. Furthermore, once condensation occurs, latent heat of vaporization is required to evaporate it, so 100 ° C
A large amount of heat is required to raise the temperature above, and thus it may take time. Dehumidifying exhaust gas, for example by cooling to a temperature equal to or lower than the precatalyst temperature,
By supplying it to the pre-catalyst after that, it is possible to prevent the condensation of water vapor in the pre-catalyst part, and avoid the troubles associated therewith. (Vii) In (iii) above, when a bypass is provided in the exhaust gas flow path from the engine to the main catalyst, exhaust gas dehumidifying means is provided in the bypass flow path, and the temperature of the front catalyst is equal to or lower than the dew point of the combustion exhaust gas. After the exhaust gas is dehumidified by the dehumidifying means of the bypass, it is guided to the main catalyst, and when the temperature of the front catalyst is equal to or higher than the dew point of the exhaust gas, the exhaust gas is directly guided to the front catalyst.
【0040】前触媒温度が排気ガスの露点以上となれば
水凝縮の可能性は無くなる。この状態で排ガスを除湿す
ることは不要な操作である。そこで、エンジンから主触
媒に至る排気ガスの流路にバイパスを設け、バイパス内
に排ガス除湿手段を設け、前触媒の温度が排ガスの露点
以下のときバイパスの除湿手段により排気ガスを除湿し
た後主触媒に導き、前触媒の温度が排気ガスの露点以上
のとき排気ガスを直接前触媒へ導くことにより、不要な
除湿をを行うこと無く前触媒における水の凝縮とそれに
伴う障害を取り除くことができる。
If the precatalyst temperature is equal to or higher than the dew point of the exhaust gas, there is no possibility of water condensation. Dehumidifying the exhaust gas in this state is an unnecessary operation. Therefore, a bypass is provided in the exhaust gas flow path from the engine to the main catalyst, an exhaust gas dehumidifying means is provided in the bypass, and the exhaust gas is dehumidified by the bypass dehumidifying means when the temperature of the front catalyst is below the dew point of the exhaust gas. By guiding the exhaust gas directly to the pre-catalyst when the temperature of the pre-catalyst is equal to or higher than the dew point of the exhaust gas, it is possible to remove water condensation in the pre-catalyst and its accompanying obstacles without unnecessary dehumidification. ..
【0041】なお、エンジンに理論空燃比よりも過剰の
燃料を供給した例が、特開昭61−58912号公報に示され
ている。しかし、エンジン始動当初の排気ガス対策につ
いては全く考慮していない。
An example in which an engine is supplied with fuel in excess of the stoichiometric air-fuel ratio is shown in JP-A-61-58912. However, no consideration is given to exhaust gas measures at the beginning of engine startup.
【0042】[0042]
【実施例】以下、具体的実施例を挙げて本発明を詳細に
説明する。但し、本発明は以下の実施例に限定されるも
のではない。
EXAMPLES The present invention will be described in detail below with reference to specific examples. However, the present invention is not limited to the following examples.
【0043】図1は、本発明の一実施例による内燃機関
の概略図である。エンジン1の排気ガス流路11に前触
媒2と主触媒3が設けられている。エンジン1の吸気管
4に空気量調整弁8と燃料供給弁9が取り付けられてい
る。空気量調整弁8と燃料供給弁9は空燃比制御部(A
/F制御部)10にて開閉度が制御されるようになって
いる。排気ガス流路11の前触媒2の前段には酸化剤
(空気)を供給する二次空気供給管6が設けられ、該二
次空気供給管6には空気ポンプが設けられている。主触
媒3の後段には温度センサー7が設けられ、排気ガスの
温度を検出するようにしている。ここで検出された温度
は空燃比制御部(A/F制御部)10に連絡され、空燃
比制御部10ではかかる温度に基づいて燃料過剰操作を
継続するか停止するかを判断するようになっている。
FIG. 1 is a schematic diagram of an internal combustion engine according to an embodiment of the present invention. A front catalyst 2 and a main catalyst 3 are provided in an exhaust gas passage 11 of the engine 1. An air amount adjusting valve 8 and a fuel supply valve 9 are attached to an intake pipe 4 of the engine 1. The air amount adjusting valve 8 and the fuel supply valve 9 are provided in the air-fuel ratio control unit (A
The opening / closing degree is controlled by the / F control unit) 10. A secondary air supply pipe 6 for supplying an oxidant (air) is provided in the exhaust gas flow passage 11 before the front catalyst 2, and an air pump is provided in the secondary air supply pipe 6. A temperature sensor 7 is provided after the main catalyst 3 to detect the temperature of exhaust gas. The temperature detected here is communicated to the air-fuel ratio control unit (A / F control unit) 10, and the air-fuel ratio control unit 10 determines whether to continue or stop the excessive fuel operation based on the temperature. ing.
【0044】図2は、ガソリンエンジンにおける空燃比
と排気ガスの組成との関係を示している。
FIG. 2 shows the relationship between the air-fuel ratio and the composition of exhaust gas in a gasoline engine.
【0045】図3は本発明による内燃機関の他の例を示
す概略図である。エンジン排気ガス流路11にバイパス
流路20を設け、このバイパス流路に前触媒2を設け
る。また、排気ガスの流れの切り替えを行うために弁1
2および弁21を設ける。温度センサー7で主触媒出口
の排気ガス温度を検出して温度信号をA/F制御部10
に送り、その温度が主触媒の作動温度以下の場合に弁2
1を閉、弁12を開として排気ガスをバイパス流路20
の前触媒2に導き、同時に空気量調制弁8および燃料供
給弁9を制御して燃料過剰の燃焼を行う。また、その温
度が主触媒の作動温度以上の場合に弁21を開,弁12
を閉として排気ガスを直接主触媒3に導き、同時に空気
量調制弁8および燃料供給弁9を制御して理論空燃比に
近い条件で燃焼を行わせる。
FIG. 3 is a schematic view showing another example of the internal combustion engine according to the present invention. A bypass passage 20 is provided in the engine exhaust gas passage 11, and the front catalyst 2 is provided in this bypass passage. In addition, the valve 1 is used to switch the flow of exhaust gas.
2 and valve 21 are provided. The temperature sensor 7 detects the temperature of the exhaust gas at the outlet of the main catalyst and outputs a temperature signal to the A / F controller 10.
To the valve 2 when the temperature is below the operating temperature of the main catalyst.
1 is closed and the valve 12 is opened to allow the exhaust gas to bypass the bypass passage 20.
To the pre-catalyst 2, and at the same time, the air amount control valve 8 and the fuel supply valve 9 are controlled to burn excess fuel. When the temperature is higher than the operating temperature of the main catalyst, the valve 21 is opened and the valve 12
Is closed to direct the exhaust gas directly to the main catalyst 3, and at the same time, the air amount control valve 8 and the fuel supply valve 9 are controlled to perform combustion under conditions close to the stoichiometric air-fuel ratio.
【0046】図4は本発明の更に他の実施例による内燃
機関の概略図を示したものである。エンジン排気ガス流
路11にバイパス流路20を設け、このバイパス流路2
0に除湿器15を設けている。また、排気ガスの流れの
切り替えを行うため弁13および14を設けている。前
触媒2内には温度センサー16を設けた。前触媒の温度
が燃焼排ガスの露点以下の場合にバイパス流路20の除
湿器15により排気ガスを除湿した後主触媒に導き、前
触媒の温度が燃焼排ガスの露点以上の場合に排気ガスを
直接前触媒へ導く。
FIG. 4 is a schematic diagram of an internal combustion engine according to still another embodiment of the present invention. A bypass flow passage 20 is provided in the engine exhaust gas flow passage 11, and the bypass flow passage 2
A dehumidifier 15 is provided at 0. Further, valves 13 and 14 are provided to switch the flow of exhaust gas. A temperature sensor 16 was provided in the front catalyst 2. When the temperature of the front catalyst is below the dew point of the combustion exhaust gas, the exhaust gas is dehumidified by the dehumidifier 15 of the bypass passage 20 and then led to the main catalyst, and when the temperature of the front catalyst is above the dew point of the combustion exhaust gas, the exhaust gas is directly fed. Lead to pre-catalyst.
【0047】実施例1 前触媒2に容積1リットル、開口比76%のセラミック
(コージェライト)ハニカムにアルミナをコーティング
し、これにパラジウム(Pd)を0.5 重量%(以下w
t%という。)を担持した触媒を用い、主触媒3に容積
2リツトルの同一材料かつ同一構造のセラミックハニカ
ムにPdを担持した触媒を用い、これらにシリーズにガ
ソリンエンジン排ガスを流通させた。空燃比(A/F)
を12として燃焼させて得たCO 7体積%(以下vol%
という。)、HC 0.35vol%の排気ガスを1000
リットル/分の流速で前触媒2に導いたところ、前触媒
出口温度は63秒後に300℃に達し、主触媒7の出口
温度は135秒後に300℃に達した。
Example 1 A pre-catalyst 2 was coated with alumina on a ceramic (cordierite) honeycomb having a volume of 1 liter and an opening ratio of 76%, and palladium (Pd) was added at 0.5% by weight (hereinafter, w).
t%. ) Was used for the main catalyst 3, and a catalyst having Pd supported on a ceramic honeycomb having the same material and the same structure and having a volume of 2 liters was used as the main catalyst 3, and gasoline engine exhaust gas was circulated through these series. Air-fuel ratio (A / F)
CO of 7% by volume (hereinafter vol%
That. ), HC 0.35 vol% exhaust gas to 1000
When it was introduced into the pre-catalyst 2 at a flow rate of liter / min, the pre-catalyst outlet temperature reached 300 ° C after 63 seconds and the outlet temperature of the main catalyst 7 reached 300 ° C after 135 seconds.
【0048】比較例1 理論空燃比に近い空燃比14.5で燃焼させて得たCO
0.9vol%、HC 0.2vol% の排気ガスを1000リッ
トル/分の流速で前触媒2に導いたところ、前触媒出口
温度は87秒後に300℃に達し、主触媒3の出口温度
は170秒後に300℃に達した。
Comparative Example 1 CO obtained by burning at an air-fuel ratio of 14.5 close to the theoretical air-fuel ratio
When exhaust gas of 0.9 vol% and HC 0.2 vol% was led to the pre-catalyst 2 at a flow rate of 1000 liter / min, the pre-catalyst outlet temperature reached 300 ° C. after 87 seconds, and the main catalyst 3 outlet temperature was 170 seconds. Later reached 300 ° C.
【0049】実施例2 実施例1と同じ前触媒および主触媒さらには同じ燃焼条
件(A/F=12)において生成した排気ガスに前触媒
の前で空気を380リットル/分添加したところ、前触
媒出口温度は40秒後に300℃に達し、主触媒出口温
度は87秒後に300℃に達した。
Example 2 When 380 liters / minute of air was added before the precatalyst to the exhaust gas produced under the same pre-catalyst and main catalyst as in Example 1 and the same combustion conditions (A / F = 12), The catalyst outlet temperature reached 300 ° C after 40 seconds and the main catalyst outlet temperature reached 300 ° C after 87 seconds.
【0050】実施例3 実施例2と同一条件で、各種触媒を用いて前触媒出口温
度300℃に達するのに要する時間を測定し表1の結果
を得た。前触媒及び主触媒の支持体としてはセラミック
ハニカムを用い、これにアルミナをコーティングして表
1に示す触媒活性成分を担持した。
Example 3 Under the same conditions as in Example 2, the time required to reach the precatalyst outlet temperature of 300 ° C. was measured using various catalysts, and the results shown in Table 1 were obtained. A ceramic honeycomb was used as a support for the precatalyst and the main catalyst, and alumina was coated on the support to support the catalytically active components shown in Table 1.
【0051】[0051]
【表1】 [Table 1]
【0052】実施例4 実施例2と同一条件で、PdおよびPtを各種多孔質担
体および支持体に担持したものについて、前触媒出口温
度300℃に達するのに要する時間を測定し表2の結果
を得た。
Example 4 Under the same conditions as in Example 2, the time required to reach the precatalyst outlet temperature of 300 ° C. was measured for Pd and Pt supported on various porous carriers and supports, and the results shown in Table 2 were obtained. Got
【0053】[0053]
【表2】 [Table 2]
【0054】実施例5 前触媒として、厚さ0.05mm のフェライト系ステンレ
ス板からなる開孔率90%のハニカムにPdを0.5wt
% 担持した触媒を用い、実施例2と同一条件で触媒昇
温速度を測定したところ、前触媒出口温度は36秒で3
00℃に達し、主触媒出口温度は83秒で300℃に達
した。
Example 5 As a pre-catalyst, 0.5 wt% of Pd was added to a honeycomb having a porosity of 90% and made of a ferritic stainless steel plate having a thickness of 0.05 mm.
%, The catalyst temperature rising rate was measured under the same conditions as in Example 2 using the supported catalyst, and the front catalyst outlet temperature was 3 seconds in 36 seconds.
The temperature of the main catalyst reached 300 ° C. in 83 seconds.
【0055】実施例6 実施例5と同一触媒,同一条件下において、触媒に3k
Wの直流電力を通じたところ、前触媒出口温度は28秒
で300℃に達し、主触媒出口温度は62秒で300℃
に達した。
Example 6 3k was added to the catalyst under the same conditions and conditions as in Example 5.
When DC power of W was passed, the outlet temperature of the front catalyst reached 300 ° C in 28 seconds, and the outlet temperature of the main catalyst reached 300 ° C in 62 seconds.
Reached
【0056】[0056]
【発明の効果】以上の本発明によれば、内燃機関のエン
ジン起動直後に排出される燃料未燃分及び部分燃焼成分
を浄化することができる。特に前触媒を設けて理論空燃
比よりも燃料過剰の状態で操作したエンジンの排気ガス
を酸化することにより前触媒を速やかに昇温し、前触媒
の後流に設けた主触媒を急速に活性化温度まで高めるこ
とができる。これにより内燃機関のエンジン起動当初の
排気時の排気ガス浄化性能を高めることができる。
As described above, according to the present invention, it is possible to purify unburned fuel components and partial combustion components discharged immediately after the engine of the internal combustion engine is started. In particular, by providing a pre-catalyst and oxidizing the exhaust gas of the engine operated in a fuel excess of the stoichiometric air-fuel ratio, the pre-catalyst is heated rapidly and the main catalyst provided in the downstream of the pre-catalyst is rapidly activated. It can be increased to the oxidization temperature. As a result, the exhaust gas purification performance at the time of exhaust of the internal combustion engine at the beginning of engine startup can be improved.
【図面の簡単な説明】[Brief description of drawings]
【図1】本発明の内燃機関の一実施例を示す概略図。FIG. 1 is a schematic diagram showing an embodiment of an internal combustion engine of the present invention.
【図2】ガソリンエンジンにおける空燃比と排気ガス組
成の関係を示すグラフ。
FIG. 2 is a graph showing the relationship between air-fuel ratio and exhaust gas composition in a gasoline engine.
【図3】本発明の内燃機関の他の実施例を示す概略図。FIG. 3 is a schematic view showing another embodiment of the internal combustion engine of the present invention.
【図4】本発明の内燃機関の他の実施態様を示す概略
図。
FIG. 4 is a schematic view showing another embodiment of the internal combustion engine of the present invention.
【符号の説明】[Explanation of symbols]
1…エンジン、2…前触媒、3…主触媒、4…吸気管、
5…空気ポンプ、6…二次空気供給管、7,16…温度
センサー、8…空気量調整弁、9…燃料調整弁、10…
空燃比制御部(A/F制御部)、11,13,14,2
1…弁、12…バイパス流路、15…除湿器。
1 ... Engine, 2 ... Front catalyst, 3 ... Main catalyst, 4 ... Intake pipe,
5 ... Air pump, 6 ... Secondary air supply pipe, 7, 16 ... Temperature sensor, 8 ... Air amount adjusting valve, 9 ... Fuel adjusting valve, 10 ...
Air-fuel ratio controller (A / F controller), 11, 13, 14, 2
1 ... Valve, 12 ... Bypass flow path, 15 ... Dehumidifier.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 FI 技術表示箇所 F02D 41/14 310 J 9039−3G (72)発明者 渡辺 紀子 茨城県日立市久慈町4026番地 株式会社日 立製作所日立研究所内 (72)発明者 小川 敏男 茨城県日立市久慈町4026番地 株式会社日 立製作所日立研究所内 (72)発明者 宮寺 博 茨城県日立市久慈町4026番地 株式会社日 立製作所日立研究所内 (72)発明者 阿田子 武士 茨城県勝田市大字高場2520番地 株式会社 日立製作所自動車機器事業部内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification number Reference number within the agency FI Technical indication location F02D 41/14 310 J 9039-3G (72) Inventor Noriko Watanabe 4026 Kuji Town, Hitachi City, Ibaraki Stock Company Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Toshio Ogawa 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitate Manufacturing Co., Ltd. Inside Hitachi Research Laboratory (72) Inventor Takeshi Atako 2520 Takaba, Katsuta City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division

Claims (22)

    【特許請求の範囲】[Claims]
  1. 【請求項1】エンジンの吸気系に燃料と空気の量を制御
    する燃料・空気制御部を有し排気系に燃焼触媒よりなる
    前触媒と排気ガス浄化主触媒とを有する内燃機関におい
    て、前記エンジンを始動してから前記排気ガス浄化触媒
    の温度が活性を示す温度に昇温するまでの間理論空燃比
    よりも燃料過剰となるように前記燃料・空気制御部を操
    作する手段を備えたことを特徴とする内燃機関。
    1. An internal combustion engine having a fuel / air control unit for controlling an amount of fuel and air in an intake system of an engine, and a pre-catalyst composed of a combustion catalyst and an exhaust gas purifying main catalyst in an exhaust system. A means for operating the fuel / air control unit so that the fuel becomes more fuel than the stoichiometric air-fuel ratio during the period from the start of the engine until the temperature of the exhaust gas purifying catalyst rises to a temperature at which it activates. Characterized internal combustion engine.
  2. 【請求項2】エンジンの吸気系に燃料と空気の量を制御
    する燃料・空気制御部を有し排気系に燃焼触媒よりなる
    前触媒と排気ガス浄化主触媒とを有する内燃機関におい
    て、前記排気ガス浄化主触媒の温度を検出する手段と、
    前記エンジンを始動してから該排気ガス浄化主触媒の検
    出温度が活性を示す温度になるまでの間理論空燃比より
    も燃料過剰となるように前記燃料・空気制御部を操作す
    る手段を備えたことを特徴とする内燃機関。
    2. An internal combustion engine having a fuel / air control unit for controlling the amount of fuel and air in an intake system of an engine, and a pre-catalyst consisting of a combustion catalyst and an exhaust gas purifying main catalyst in an exhaust system. Means for detecting the temperature of the gas purification main catalyst,
    A means for operating the fuel / air control unit is provided so that the fuel exceeds the stoichiometric air-fuel ratio from the time when the engine is started until the temperature detected by the exhaust gas purifying main catalyst reaches a temperature at which the catalyst shows activity. An internal combustion engine characterized by the above.
  3. 【請求項3】エンジンの吸気系に燃料と空気の量を制御
    する燃料・空気制御部を有し排気系に燃焼触媒よりなる
    前触媒と排気ガス浄化主触媒とを有する内燃機関におい
    て、前記エンジンを始動してから前記排気ガス浄化主触
    媒の温度が活性を示す温度になるまでの間は理論空燃比
    よりも燃料過剰とし前記排気ガス浄化主触媒の温度が活
    性を示す温度になったならば理論空燃比となるように前
    記燃料・空気制御部を切り替え操作する手段を備えたこ
    とを特徴とする内燃機関。
    3. An internal combustion engine having a fuel / air control unit for controlling the amount of fuel and air in an intake system of an engine, and a pre-catalyst composed of a combustion catalyst and an exhaust gas purifying main catalyst in an exhaust system. When the temperature of the exhaust gas purifying main catalyst becomes the temperature at which the exhaust gas purifying main catalyst becomes active, and the temperature of the exhaust gas purifying main catalyst becomes the temperature at which the exhaust gas purifying main catalyst becomes active. An internal combustion engine comprising means for switching and operating the fuel / air control unit so that a stoichiometric air-fuel ratio is achieved.
  4. 【請求項4】エンジンの排気系に燃焼触媒よりなる前触
    媒と排気ガス浄化主触媒とを有する内燃機関において、
    前記エンジンに理論空燃比よりも過剰の燃料を供給する
    手段と、前記排気ガス浄化主触媒の温度が活性を示す温
    度に昇温するまで前記燃料過剰の状態を持続する燃料過
    剰時間制御手段とを備えたことを特徴とする内燃機関。
    4. An internal combustion engine having a pre-catalyst comprising a combustion catalyst and an exhaust gas purifying main catalyst in an engine exhaust system,
    A means for supplying fuel to the engine in excess of the stoichiometric air-fuel ratio, and a fuel excess time control means for maintaining the excess fuel state until the temperature of the exhaust gas purifying main catalyst rises to a temperature at which it is active. An internal combustion engine characterized by being provided.
  5. 【請求項5】エンジンの排気系に燃焼触媒よりなる前触
    媒と排気ガス浄化主触媒とを有する内燃機関において、
    前記排気ガス浄化主触媒が活性を示す温度に昇温するま
    で前記エンジンを理論空燃比よりも燃料過剰の状態で駆
    動する燃料過剰運転手段を備えたことを特徴とする内燃
    機関。
    5. An internal combustion engine having a pre-catalyst comprising a combustion catalyst and an exhaust gas purifying main catalyst in an exhaust system of the engine,
    An internal combustion engine comprising: an excess fuel operation means for driving the engine in a state in which the exhaust gas purifying main catalyst has a fuel excess of a stoichiometric air-fuel ratio until the temperature rises to a temperature at which the main catalyst becomes active.
  6. 【請求項6】請求項1〜5において、前記理論空燃比よ
    りも燃料過剰の状態における空燃比A/F(Aは空気重
    量,Fは燃料重量)が13以下,10以上であることを
    特徴とする内燃機関。
    6. The air-fuel ratio A / F (A is air weight, F is fuel weight) in a state where the fuel is in excess of the stoichiometric air-fuel ratio, is 13 or less and 10 or more. Internal combustion engine.
  7. 【請求項7】請求項1〜5において、前記理論空燃比よ
    りも燃料過剰の状態でエンジンを駆動したときに排気ガ
    ス中のCO濃度が3%以上,14%以下となるように前
    記燃料過剰量を設定することを特徴とする内燃機関。
    7. The fuel excess according to claim 1, wherein the CO concentration in the exhaust gas is 3% or more and 14% or less when the engine is driven in a fuel excess state with respect to the stoichiometric air-fuel ratio. Internal combustion engine characterized by setting a quantity.
  8. 【請求項8】エンジンの吸気系に理論空燃比よりも過剰
    の燃料を供給する手段を有し、前記エンジンの排気系に
    該燃料過剰供給によって生成した排気ガス中の可燃成分
    を接触燃焼する燃焼触媒を有することを特徴とする内燃
    機関。
    8. Combustion which has means for supplying an excess amount of fuel to the intake system of the engine in excess of the stoichiometric air-fuel ratio, and combusts combustible components in exhaust gas produced by the excessive supply of fuel to the exhaust system of the engine by catalytic combustion. An internal combustion engine having a catalyst.
  9. 【請求項9】請求項1〜5において、前記エンジンから
    前記排気ガス浄化主触媒に至る排気ガス流路にバイパス
    路を備え該バイパス路に前記前触媒を備えたことを特徴
    とする内燃機関。
    9. The internal combustion engine according to claim 1, wherein a bypass passage is provided in an exhaust gas passage extending from the engine to the exhaust gas purifying main catalyst, and the precatalyst is provided in the bypass passage.
  10. 【請求項10】請求項9において、前記エンジンに理論
    空燃比よりも過剰の燃料が供給されている間は前記バイ
    パス路を経て前記排気ガス浄化主触媒に排気ガスを流し
    該過剰燃料供給が停止されたならば排気ガスを直接前記
    排気ガス浄化主触媒に流すように排気ガス流路を切り替
    える手段を有することを特徴とする内燃機関。
    10. The exhaust gas supply system according to claim 9, wherein while the engine is supplied with fuel in excess of the stoichiometric air-fuel ratio, exhaust gas is caused to flow through the exhaust gas purifying main catalyst through the bypass passage to stop the excess fuel supply. An internal combustion engine having means for switching the exhaust gas flow path so that the exhaust gas is caused to flow directly to the exhaust gas purifying main catalyst.
  11. 【請求項11】請求項1〜5,9及び10において、前
    記排気系の前記前触媒の前段に酸化剤を供給する手段を
    備えたことを特徴とする内燃機関。
    11. An internal combustion engine according to any one of claims 1 to 5, 9 and 10, characterized in that it is provided with a means for supplying an oxidant to the front stage of the front catalyst of the exhaust system.
  12. 【請求項12】請求項11において、前記排気系の前記
    前触媒の前段に排気ガスの理論酸素消費量と等量かそれ
    以上の酸化剤を供給する前記酸化剤供給手段を備えたこ
    とを特徴とする内燃機関。
    12. The oxidant supply means according to claim 11, wherein the oxidant supply means for supplying an oxidant in an amount equal to or more than a theoretical oxygen consumption amount of exhaust gas is provided before the precatalyst in the exhaust system. Internal combustion engine.
  13. 【請求項13】請求項1〜5,9,10及び11におい
    て、前記前触媒が周期律表の第VIII族,Ib族,希土類金
    属,亜鉛および錫から選ばれた金属あるいは酸化物の少
    なくとも1種よりなる触媒活性成分を有することを特徴
    とする内燃機関。
    13. The catalyst according to claim 1, wherein the precatalyst is at least one of metals or oxides selected from Group VIII, Ib of the Periodic Table, rare earth metals, zinc and tin. An internal combustion engine having a catalytically active component consisting of seeds.
  14. 【請求項14】請求項1〜13において、前記エンジン
    に供給する燃料がガソリン或はガソリンを含む燃料から
    なることを特徴とする内燃機関。
    14. The internal combustion engine according to claim 1, wherein the fuel supplied to the engine is gasoline or a fuel containing gasoline.
  15. 【請求項15】理論空燃比の燃料と空気をエンジンに供
    給して駆動し排気ガスを排気ガス浄化触媒によって浄化
    するようにした内燃機関の運転方法において、前記エン
    ジンの起動時から少なくとも前記排気ガス浄化触媒が活
    性を示す温度に昇温するまでの間前記エンジンを理論空
    燃比よりも燃料過剰の状態で駆動し、生成した排気ガス
    中の可燃成分を燃焼触媒により接触燃焼してから前記排
    気ガス浄化触媒に送るようにしたことを特徴とする内燃
    機関の運転方法。
    15. A method of operating an internal combustion engine in which fuel and air having a stoichiometric air-fuel ratio are supplied to an engine to drive the engine and exhaust gas is purified by an exhaust gas purifying catalyst, wherein at least the exhaust gas is discharged from the start of the engine. Until the temperature of the purifying catalyst rises to the temperature at which it is active, the engine is driven with a fuel excess of the stoichiometric air-fuel ratio, and the combustible component in the generated exhaust gas is catalytically burned by a combustion catalyst before the exhaust gas is discharged. A method for operating an internal combustion engine, which is characterized in that it is sent to a purification catalyst.
  16. 【請求項16】理論空燃比よりも燃料過剰の状態でエン
    ジンを駆動し、生成した排気ガスを燃焼触媒によって接
    触燃焼してから系外に排出するようにしたことを特徴と
    する内燃機関の運転方法。
    16. An operation of an internal combustion engine, characterized in that the engine is driven in a state where the fuel is in excess of the stoichiometric air-fuel ratio, the generated exhaust gas is catalytically burned by a combustion catalyst and then discharged to the outside of the system. Method.
  17. 【請求項17】理論空燃比よりも燃料過剰の状態でエン
    ジンを始動してその排気ガスを燃焼触媒によって接触燃
    焼してから排気ガス浄化触媒に送り、該排気ガス浄化触
    媒の温度が活性を示す温度まで昇温したならば燃料過剰
    供給を停止しその排気ガスを直接前記排気ガス浄化触媒
    に送るようにしたことを特徴とする内燃機関の運転方
    法。
    17. An engine is started in a state where the fuel is in excess of the stoichiometric air-fuel ratio, the exhaust gas is catalytically burned by a combustion catalyst and then sent to the exhaust gas purifying catalyst, and the temperature of the exhaust gas purifying catalyst shows activity. An operating method of an internal combustion engine, characterized in that, when the temperature is raised to a temperature, the excessive fuel supply is stopped and the exhaust gas is directly sent to the exhaust gas purifying catalyst.
  18. 【請求項18】内燃機関を動力源として運転する内燃動
    車において、前記内燃機関エンジンの排気ガス流路に排
    気ガス浄化触媒を備え、前記エンジンを始動してから排
    気ガスの温度が該排気ガス浄化触媒が活性を示す温度に
    昇温するまでの間前記エンジンに理論空燃比よりも過剰
    の燃料を供給する手段を備え、該燃料過剰状態でのエン
    ジン駆動によって排出された排気ガスを接触燃焼する燃
    焼触媒を前記排気ガス流路の前記排気ガス浄化触媒の上
    流側に備えたことを特徴とする内燃動車。
    18. An internal combustion vehicle that operates using an internal combustion engine as a power source, wherein an exhaust gas purifying catalyst is provided in an exhaust gas passage of the internal combustion engine, and the temperature of the exhaust gas after the engine is started is the exhaust gas purifying. Combustion in which exhaust gas exhausted by driving the engine in the excess fuel state is catalytically burned by means of supplying fuel to the engine in excess of the stoichiometric air-fuel ratio until the temperature of the catalyst rises to a temperature at which the catalyst shows activity. An internal combustion motor vehicle comprising a catalyst on the upstream side of the exhaust gas purifying catalyst in the exhaust gas passage.
  19. 【請求項19】内燃機関エンジンの排気ガス流路に排気
    ガス浄化触媒を備えた自動車において、前記エンジンを
    始動してから排気ガスの温度が前記排気ガス浄化触媒が
    活性を示す温度に昇温するまでの間前記エンジンに理論
    空燃比よりも過剰の燃料を供給する手段を備え、該燃料
    過剰状態でのエンジン駆動によって排出された排気ガス
    を接触燃焼する燃焼触媒を前記排気ガス流路の前記排気
    ガス浄化触媒の上流側に備えたことを特徴とする自動
    車。
    19. In an automobile equipped with an exhaust gas purifying catalyst in an exhaust gas passage of an internal combustion engine, the temperature of the exhaust gas rises to a temperature at which the exhaust gas purifying catalyst becomes active after the engine is started. Up to the stoichiometric air-fuel ratio for supplying fuel to the engine in excess of the stoichiometric air-fuel ratio, and the exhaust gas in the exhaust gas flow path is provided with a combustion catalyst for catalytically burning exhaust gas discharged by driving the engine in the excessive fuel state. An automobile characterized by being provided upstream of the gas purification catalyst.
  20. 【請求項20】請求項1〜14において、前記前触媒を
    加熱する加熱手段を備えたことを特徴とする内燃機関。
    20. The internal combustion engine according to claim 1, further comprising heating means for heating the precatalyst.
  21. 【請求項21】請求項1〜14及び20において、前記
    エンジンから前記前触媒に至る排気ガス流路に除湿手段
    を備えたことを特徴とする内燃機関。
    21. An internal combustion engine according to any one of claims 1 to 14 and 20, characterized in that a dehumidifying means is provided in an exhaust gas passage extending from the engine to the front catalyst.
  22. 【請求項22】請求項9及び10において、前記バイパ
    ス流路の前記前触媒の後段に排気ガス除湿手段を備え、
    該前触媒の温度が排気ガスの露点以下のときに該除湿手
    段により排気ガスを除湿して前記排気ガス浄化主触媒に
    導くようにしたことを特徴とする内燃機関。
    22. The exhaust gas dehumidifying means according to claim 9 or 10, wherein exhaust gas dehumidifying means is provided downstream of the front catalyst in the bypass passage.
    An internal combustion engine, wherein when the temperature of the pre-catalyst is equal to or lower than the dew point of exhaust gas, the dehumidifying means dehumidifies the exhaust gas and guides it to the exhaust gas purifying main catalyst.
JP3241671A 1991-09-20 1991-09-20 Internal combustion engine, operating method thereof, and automobile Expired - Fee Related JP2601072B2 (en)

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Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
JP3241671A JP2601072B2 (en) 1991-09-20 1991-09-20 Internal combustion engine, operating method thereof, and automobile
DE4231575A DE4231575C2 (en) 1991-09-20 1992-09-21 Method and device for controlling an internal combustion engine
US08/351,167 US5577383A (en) 1991-09-20 1994-11-30 Apparatus for controlling internal combustion engine

Publications (2)

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JPH0579320A true JPH0579320A (en) 1993-03-30
JP2601072B2 JP2601072B2 (en) 1997-04-16

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