JP2000179326A - Particulate filter reclamation control device - Google Patents

Particulate filter reclamation control device

Info

Publication number
JP2000179326A
JP2000179326A JP10353177A JP35317798A JP2000179326A JP 2000179326 A JP2000179326 A JP 2000179326A JP 10353177 A JP10353177 A JP 10353177A JP 35317798 A JP35317798 A JP 35317798A JP 2000179326 A JP2000179326 A JP 2000179326A
Authority
JP
Japan
Prior art keywords
exhaust
engine
expansion stroke
amount
particulate filter
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
JP10353177A
Other languages
Japanese (ja)
Other versions
JP3454351B2 (en
Inventor
Atsushi Tawara
淳 田原
Toshihisa Sugiyama
敏久 杉山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
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 Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP35317798A priority Critical patent/JP3454351B2/en
Priority to DE19957715A priority patent/DE19957715C2/en
Priority to FR9915162A priority patent/FR2786529B1/en
Publication of JP2000179326A publication Critical patent/JP2000179326A/en
Application granted granted Critical
Publication of JP3454351B2 publication Critical patent/JP3454351B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/021—Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
    • F02D41/029—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a particulate filter
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/021—Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/024—Introducing 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B29/00—Engines characterised by provision for charging or scavenging not provided for in groups F02B25/00, F02B27/00 or F02B33/00 - F02B39/00; Details thereof
    • F02B29/04—Cooling of air intake supply
    • F02B29/0406—Layout of the intake air cooling or coolant circuit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02—EGR systems specially adapted for supercharged engines
    • F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
    • F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02—EGR systems specially adapted for supercharged engines
    • F02M26/09—Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine
    • F02M26/10—Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system
    • 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
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Processes For Solid Components From Exhaust (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)

Abstract

PROBLEM TO BE SOLVED: To accurately control engine exhaust temperature within a short period of time to a target level during particulate filter reclamation processes. SOLUTION: A particulate filter (DPE) 40 is placed at each of the exhaust ports of all cylinders of a diesel engine 1. An electronic control unit(ECU) 30 of the engine increases exhaust temperature to perform reclamation of DPFs by using any one or more of the following methods: exhaust throttling operation by means of an exhaust throttle valve 37; expansion stroke injection operation in which fuel is injected during an expansion stroke of each cylinder; EGR operation; and, main fuel injection control operation in which the amount of main fuel injected and injection timing for each cylinder are changed. When performing the exhaust throttling operation, the ECU sets a value depending on engine operating conditions for each control amount of the amount of fuel injected during the expansion stroke and injection timing, recirculating exhaust flow rate, and the amount of main fuel injected and injection timing, each different from those when the exhaust throttling operation is not performed.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、内燃機関の排気中
のパティキュレートを捕集するパティキュレートフィル
タの再生処理を制御するパティキュレートフィルタの再
生処理制御装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate filter regeneration control device for controlling a particulate filter regeneration process for collecting particulates in exhaust gas from an internal combustion engine.

【０００２】[0002]

【従来の技術】内燃機関、特にディーゼル機関の排気中
にはカーボン等を主成分とする排気微粒子（パティキュ
レート）が比較的多量に含まれている。このため、これ
らのパティキュレートの大気放出を防止するためのパテ
ィキュレート除去手段が種々提案されている。2. Description of the Related Art The exhaust gas of an internal combustion engine, especially a diesel engine, contains a relatively large amount of exhaust particulates mainly composed of carbon or the like. For this reason, various particulate removal means for preventing the release of these particulates to the atmosphere have been proposed.

【０００３】パティキュレートの除去手段としては、機
関の排気通路に例えばセラミック製や金属不織布製等の
パティキュレートフィルタを配置してフィルタを通過す
る排気中のパティキュレートを捕集する方法が提案され
ている。このようなパティキュレートフィルタを使用し
た場合には、機関の運転とともにフィルタに捕集される
パティキュレートの量が増大し、フィルタでの排気圧力
損失が増大するようになる。このため、排気圧力損失の
増大による機関性能の低下を防止するために、フィルタ
に捕集されたパティキュレートを定期的に燃焼させ、パ
ティキュレートフィルタを再生することが必要となる。[0003] As a means for removing particulates, a method has been proposed in which a particulate filter made of, for example, ceramic or non-woven metal fabric is disposed in an exhaust passage of an engine to collect particulates in exhaust gas passing through the filter. I have. When such a particulate filter is used, the amount of particulate collected by the filter increases with the operation of the engine, and the exhaust pressure loss at the filter increases. Therefore, in order to prevent a decrease in engine performance due to an increase in exhaust pressure loss, it is necessary to periodically burn the particulates collected by the filter and regenerate the particulate filter.

【０００４】この場合、特にディーゼル機関では排気温
度が比較的低いためかなりの高負荷運転時以外ではパテ
ィキュレートが自然着火することはなく、パティキュレ
ート温度を着火温度まで上昇させるために何らかの補助
的手段を用いた再生操作を行なうことが必要となる。こ
の種の再生操作を行なうパティキュレートフィルタの再
生制御装置の例としては、例えば特開平１０−５４２７
０号公報に記載されたものがある。In this case, especially in a diesel engine, since the exhaust gas temperature is relatively low, the particulate does not spontaneously ignite except during a considerably high load operation, and some auxiliary means for raising the particulate temperature to the ignition temperature. It is necessary to carry out a reproduction operation using. An example of a particulate filter regeneration control device for performing this type of regeneration operation is disclosed in, for example, JP-A-10-5427.
No. 0 publication.

【０００５】同公報の装置は、ディーゼル機関の排気通
路に配置したパティキュレートフィルタの再生処理を行
なうために、機関燃料噴射量を増量して排気温度を上昇
させるとともに、オルタネータ等の機関補機の負荷を変
化させて燃料噴射量の増大による機関出力の増大分を吸
収するようにしている。このように、パティキュレート
フィルタ再生処理時の機関外部出力増大を抑制すること
により、機関運転性に影響を与えることなくパティキュ
レートフィルタの再生操作を行なうことが可能となる。The apparatus disclosed in the above publication increases the engine fuel injection amount to raise the exhaust gas temperature and performs engine auxiliary equipment such as an alternator in order to regenerate a particulate filter disposed in an exhaust passage of a diesel engine. The load is changed to absorb the increase in the engine output due to the increase in the fuel injection amount. Thus, by suppressing the increase in the engine external output during the particulate filter regeneration processing, it is possible to perform the particulate filter regeneration operation without affecting the engine operability.

【０００６】[0006]

【発明が解決しようとする課題】ところが、上記特開平
１０−５４２７０号公報の装置では、通常の運転状態を
維持しながら機関出力のみを増大しているため、排気温
度を精度よく目標温度に制御することが困難な場合があ
る。例えば、自動車用機関に上記公報の装置を適用した
場合には、機関回転数、走行負荷等は車両走行条件によ
り決まってしまうため、機関出力（機関燃料噴射量）の
増大量はこれらの走行条件の制限を受けて自由に設定す
ることができない場合が生じ、排気温度を目標温度に制
御できない場合が生じる。また、上記公報のように機関
出力を増大することにより排気温度を上昇させる場合に
は、機関出力（排気温度）の上昇速度は制限されてしま
うため短時間で排気温度を目標温度に上昇させることが
困難な場合がある。このため、上記公報の装置ではパテ
ィキュレートフィルタの再生操作に比較的長時間を要す
る問題がある。However, in the apparatus disclosed in JP-A-10-54270, since only the engine output is increased while maintaining the normal operation state, the exhaust gas temperature is controlled accurately to the target temperature. Can be difficult to do. For example, when the apparatus disclosed in the above publication is applied to an automobile engine, the engine speed, the running load, and the like are determined by the vehicle running conditions. In some cases, the exhaust gas temperature cannot be freely set due to the above restriction, and the exhaust gas temperature cannot be controlled to the target temperature. Further, when the exhaust gas temperature is increased by increasing the engine output as in the above-mentioned publication, the rate of increase of the engine output (exhaust gas temperature) is limited, so that the exhaust gas temperature must be raised to the target temperature in a short time. Can be difficult. For this reason, the apparatus disclosed in the above publication has a problem in that the regeneration operation of the particulate filter requires a relatively long time.

【０００７】本発明は上記問題に鑑み、機関排気温度を
短時間で精度良く目標温度に制御することにより、短時
間でパティキュレートフィルタ再生処理を完了すること
が可能なパティキュレートフィルタの再生処理制御装置
を提供することを目的としている。SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a particulate filter regeneration control capable of completing a particulate filter regeneration process in a short time by accurately controlling the engine exhaust temperature to a target temperature in a short time. It is intended to provide a device.

【０００８】[0008]

【課題を解決するための手段】請求項１に記載の発明に
よれば、内燃機関の排気中のパティキュレートを捕集す
るパティキュレートフィルタの再生処理を機関運転状態
に応じて制御する再生処理制御装置であって、内燃機関
の排気通路に配置した排気絞り弁を作動させて排気流量
を低減する排気絞り操作と、各気筒の膨張行程中に燃料
噴射を行なう膨張行程噴射操作と、機関排気系から吸気
系に排気の一部を再循環させるするＥＧＲ操作と、各気
筒の主燃料噴射量と噴射時期とを変更する主燃料噴射制
御操作のいずれか１つ、または２つ以上の組合せにより
機関排気温度を上昇させてパティキュレートフィルタ内
に捕集されたパティキュレートを燃焼させるパティキュ
レートフィルタ再生処理を行うとともに、前記排気絞り
操作を実施する場合には、前記膨張行程燃料噴射量及び
噴射時期、再循環排気流量、主燃料噴射量及び噴射時
期、の各操作量を予め定めた第１の関係に基づいて機関
運転状態に応じて決定し、排気絞り操作を実施しない場
合には、前記各操作量を前記第１の関係とは異なる予め
定めた第２の関係に基づいて機関運転状態に応じて決定
するパティキュレートフィルタの再生処理制御装置が提
供される。According to the first aspect of the present invention, there is provided a regeneration control for controlling a regeneration process of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine in accordance with an engine operating state. An exhaust throttle operation for reducing an exhaust flow rate by operating an exhaust throttle valve disposed in an exhaust passage of an internal combustion engine; an expansion stroke injection operation for performing fuel injection during an expansion stroke of each cylinder; and an engine exhaust system. The engine is operated by one or a combination of two or more of an EGR operation for recirculating a part of exhaust gas from the engine to an intake system and a main fuel injection control operation for changing a main fuel injection amount and an injection timing of each cylinder. When performing a particulate filter regeneration process for raising the exhaust gas temperature to burn the particulates collected in the particulate filter and performing the exhaust throttle operation, Determining the manipulated variables of the expansion stroke fuel injection amount and injection timing, the recirculation exhaust flow rate, the main fuel injection amount and the injection timing according to the engine operating state based on a predetermined first relationship; When the exhaust throttle operation is not performed, the particulate filter regeneration processing control device that determines each of the operation amounts based on the engine operating state based on a predetermined second relationship different from the first relationship is provided. Provided.

【０００９】すなわち、請求項１の発明ではパティキュ
レートフィルタ再生操作のための排気絞り実施時には、
排気絞りを実施しない場合とは異なる関係に基づいて機
関運転状態（例えば機関負荷、回転数等）に応じて膨張
行程燃料噴射量及び噴射時期、再循環排気流量、主燃料
噴射量、噴射時期等の各操作量を決定する。例えば、排
気絞り実施時のこれらの操作量は、排気絞りを実施した
状態で実際に機関を運転し、機関排気温度が目標温度に
なる値を予め求めておき、機関運転状態と必要とされる
各操作量との関係を上記第２の関係として設定してお
く。これにより、排気絞り実施の有無に応じて機関運転
状態に基づいて適切な操作量が設定されるようになるた
め、再生操作実施時に短時間で機関排気温度が目標温度
に制御されるようになる。That is, according to the first aspect of the present invention, when the exhaust throttle for the particulate filter regeneration operation is performed,
The expansion stroke fuel injection amount and the injection timing, the recirculation exhaust flow rate, the main fuel injection amount, the injection timing, etc. according to the engine operating state (for example, engine load, rotation speed, etc.) based on a relationship different from the case where the exhaust throttle is not performed. Is determined. For example, these manipulated variables at the time of performing the exhaust throttling are determined by operating the engine in a state where the exhaust throttling is performed, obtaining a value at which the engine exhaust temperature becomes a target temperature in advance, and determining the engine operating state. The relationship with each operation amount is set as the second relationship. Accordingly, an appropriate operation amount is set based on the engine operating state according to whether or not the exhaust throttle is performed, so that the engine exhaust temperature is controlled to the target temperature in a short time when the regeneration operation is performed. .

【００１０】請求項２に記載の発明によれば、内燃機関
の排気中のパティキュレートを捕集するパティキュレー
トフィルタの再生処理を機関運転状態に応じて制御する
再生処理制御装置であって、内燃機関の各気筒の膨張行
程中に燃料噴射を行なう膨張行程噴射操作により機関排
気温度を上昇させてパティキュレートフィルタ内に捕集
されたパティキュレートを燃焼させるパティキュレート
フィルタ再生処理を行うとともに、膨張行程噴射操作実
施中に、機関排気系から吸気系に排気の一部を再循環さ
せるＥＧＲ操作を実施する場合には、膨張行程噴射操作
を実施しない場合に較べて前記ＥＧＲ操作における再循
環排気流量を増大させるパティキュレートフィルタの再
生処理制御装置が提供される。According to a second aspect of the present invention, there is provided a regeneration control device for controlling a regeneration process of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine according to an engine operating state. An expansion stroke injection operation for injecting fuel during the expansion stroke of each cylinder of the engine raises the engine exhaust temperature to perform a particulate filter regeneration process for burning the particulates collected in the particulate filter, and an expansion stroke. When performing the EGR operation for recirculating a part of the exhaust gas from the engine exhaust system to the intake system during the execution of the injection operation, the recirculation exhaust flow rate in the EGR operation is reduced as compared with the case where the expansion stroke injection operation is not performed. An apparatus for controlling the regeneration of a particulate filter is provided.

【００１１】すなわち、請求項２の発明では膨張行程噴
射操作を実施することによりパティキュレートフィルタ
の再生処理が行なわれる。各気筒の主燃料噴射とは別に
膨張行程中に噴射された燃料は、気筒膨張行程中に燃焼
して高温のまま排気ポートから排出される。このため膨
張行程噴射操作により排気温度が上昇する。一方、ＥＧ
Ｒ操作が行なわれると高温の排気が吸気系に還流される
ため、吸気温度が上昇しそれに応じて排気温度も上昇す
る。このため、膨張行程噴射操作とＥＧＲ操作とを同時
に行なえば更に排気温度を上昇させることができる。That is, in the second aspect of the present invention, the regeneration process of the particulate filter is performed by performing the expansion stroke injection operation. Fuel injected during the expansion stroke separately from the main fuel injection of each cylinder burns during the cylinder expansion stroke and is discharged from the exhaust port at a high temperature. Therefore, the exhaust temperature rises due to the expansion stroke injection operation. On the other hand, EG
When the R operation is performed, high-temperature exhaust gas is recirculated to the intake system, so that the intake air temperature rises and the exhaust gas temperature rises accordingly. Therefore, if the expansion stroke injection operation and the EGR operation are performed simultaneously, the exhaust gas temperature can be further increased.

【００１２】ところで、膨張行程噴射を実施すると排気
温度の上昇により排気エネルギが増大する。このため、
例えばターボチャージャ等の排気過給機を有する機関で
は膨張行程噴射操作により過給機の過給性能が上昇し機
関への吸入空気量が増大する。このため、所望の温度ま
で排気温度を上昇させるためには膨張行程噴射における
燃料噴射量を更に増大する必要が生じる。そこで、本発
明では膨張行程噴射操作実施時には、実施しない場合に
較べてＥＧＲ操作により還流する再循環排気流量を増大
することにより燃料噴射量の増大を防止する。再循環排
気流量（ＥＧＲガス量）を増大することにより実際に気
筒に吸入される新気流量の増加が抑制されるため、排気
温度を上昇させるための膨張行程燃料噴射量増大が抑制
されるようになる。By the way, when the expansion stroke injection is performed, the exhaust energy increases due to an increase in the exhaust gas temperature. For this reason,
For example, in an engine having an exhaust supercharger such as a turbocharger, the supercharging performance of the supercharger is increased by the expansion stroke injection operation, and the amount of air taken into the engine is increased. Therefore, in order to raise the exhaust gas temperature to a desired temperature, it is necessary to further increase the fuel injection amount in the expansion stroke injection. Therefore, in the present invention, when the expansion stroke injection operation is performed, an increase in the fuel injection amount is prevented by increasing the flow rate of the recirculated exhaust gas that is recirculated by the EGR operation as compared with a case where the expansion stroke injection operation is not performed. By increasing the recirculation exhaust gas flow rate (EGR gas amount), an increase in the flow rate of fresh air actually sucked into the cylinder is suppressed, so that an increase in the expansion stroke fuel injection amount for increasing the exhaust gas temperature is suppressed. become.

【００１３】請求項３に記載の発明によれば、内燃機関
の排気中のパティキュレートを捕集するパティキュレー
トフィルタの再生処理を機関運転状態に応じて制御する
再生処理制御装置であって、内燃機関の排気通路に配置
した排気絞り弁を作動させて排気流量を低減する排気絞
り操作と、各気筒の膨張行程中に燃料噴射を行なう膨張
行程噴射操作の一方または両方を実施することにより機
関排気温度を上昇させてパティキュレートフィルタ内に
捕集されたパティキュレートを燃焼させるパティキュレ
ートフィルタ再生処理を行うとともに、前記膨張行程噴
射操作と前記排気絞り操作との両方を同時に実施する場
合には、機関排気系から吸気系に排気の一部を再循環さ
せるＥＧＲ操作を停止するパティキュレートフィルタの
再生処理制御装置が提供される。According to a third aspect of the present invention, there is provided a regeneration control device for controlling a regeneration process of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine in accordance with an engine operating state. Engine exhaust is performed by performing one or both of an exhaust throttle operation for reducing an exhaust flow rate by operating an exhaust throttle valve disposed in an exhaust passage of the engine and an expansion stroke injection operation for performing fuel injection during an expansion stroke of each cylinder. When performing a particulate filter regeneration process for raising the temperature to burn the particulates collected in the particulate filter, and performing both the expansion stroke injection operation and the exhaust throttle operation simultaneously, the engine A regeneration control device for a particulate filter for stopping an EGR operation for recirculating a part of exhaust gas from an exhaust system to an intake system It is provided.

【００１４】すなわち、請求項３の発明では、膨張行程
噴射操作と排気絞り操作とのいずれか一方または両方に
よりパティキュレートフィルタの再生処理が行なわれ
る。例えば、膨張行程噴射と排気絞り操作とを組み合わ
せることにより、膨張行程噴射により増大した機関出力
を排気絞り損失により相殺することができるため、機関
出力の増大を抑制しながら膨張行程噴射の燃料噴射量を
増量することができる。ところが、膨張行程噴射操作と
排気絞り操作とを同時に実施すると、排気温度の上昇と
排気絞り損失とのために排気圧力が大幅に上昇する場合
がある。この場合ＥＧＲ操作を実施していると排気圧力
の増大のためにＥＧＲガス量の制御性が悪化してしま
う。すなわち、流量制御弁（ＥＧＲ弁）等でＥＧＲガス
量を制御するような場合には排気圧力が増大するとわず
かに弁開度が増加してもＥＧＲガス量が大幅に増大する
ため気筒内で新気不足のための失火が生じやすくなる。
このため、本発明では膨張行程噴射操作と排気絞り操作
とを同時に実施する場合にはＥＧＲ操作を停止すること
として機関の失火が生じることを防止している。That is, according to the third aspect of the invention, the particulate filter is regenerated by one or both of the expansion stroke injection operation and the exhaust throttle operation. For example, by combining the expansion stroke injection with the exhaust throttle operation, the engine output increased by the expansion stroke injection can be offset by the exhaust throttle loss, so that the fuel injection amount of the expansion stroke injection can be suppressed while suppressing the increase in the engine output. Can be increased. However, if the expansion stroke injection operation and the exhaust throttle operation are performed simultaneously, the exhaust pressure may increase significantly due to the increase in exhaust temperature and exhaust throttle loss. In this case, if the EGR operation is performed, the controllability of the EGR gas amount is deteriorated due to an increase in the exhaust pressure. That is, in the case where the EGR gas amount is controlled by a flow control valve (EGR valve) or the like, the EGR gas amount greatly increases even if the valve opening slightly increases when the exhaust pressure increases. Misfire easily occurs due to lack of air.
For this reason, in the present invention, when the expansion stroke injection operation and the exhaust throttle operation are performed simultaneously, the EGR operation is stopped to prevent the engine from misfiring.

【００１５】請求項４に記載の発明によれば、内燃機関
の排気中のパティキュレートを捕集するパティキュレー
トフィルタの再生処理を機関運転状態に応じて制御する
再生処理制御装置であって、内燃機関の排気通路に配置
した排気絞り弁を作動させて排気流量を低減する排気絞
り操作と、各気筒の膨張行程中に燃料噴射を行なう膨張
行程噴射操作の一方または両方を実施することにより機
関排気温度を上昇させてパティキュレートフィルタ内に
捕集されたパティキュレートを燃焼させるパティキュレ
ートフィルタ再生処理を行うとともに、前記膨張行程噴
射操作実施の有無、及び前記膨張行程噴射操作実施時に
は更に前記排気絞り操作実施の有無、に応じて機関目標
吸入空気量を機関運転状態に基づいてそれぞれ異なる値
に設定し、機関吸気通路に配置された吸気絞り弁の開度
と機関排気系から機関吸気系に再循環させる排気の量を
制御するＥＧＲ弁の開度との一方または両方を制御する
ことにより機関吸入空気量を前記目標吸入空気量に制御
するパティキュレートフィルタの再生処理制御装置が提
供される。According to a fourth aspect of the present invention, there is provided a regeneration control device for controlling a regeneration process of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine in accordance with an engine operating state. Engine exhaust is performed by performing one or both of an exhaust throttle operation for reducing an exhaust flow rate by operating an exhaust throttle valve disposed in an exhaust passage of the engine and an expansion stroke injection operation for performing fuel injection during an expansion stroke of each cylinder. In addition to performing a particulate filter regeneration process for raising the temperature to burn the particulates collected in the particulate filter, performing the expansion stroke injection operation, and further performing the exhaust throttle operation when performing the expansion stroke injection operation The engine target intake air amount is set to different values based on the engine operating state, depending on whether or not the engine is in operation. The engine intake air amount is controlled by controlling one or both of an opening degree of an intake throttle valve arranged in a passage and an opening degree of an EGR valve for controlling an amount of exhaust gas recirculated from the engine exhaust system to the engine intake system. There is provided a regeneration control device for a particulate filter that controls a target intake air amount.

【００１６】すなわち、請求項４の発明では膨張行程噴
射操作の有無、及び排気絞り操作の有無、に応じて異な
る値に機関の目標空気量が設定される。このため、膨張
行程噴射操作及び排気絞り操作によるパティキュレート
フィルタ再生処理の際に機関運転状態に応じて吸入空気
量が最適な値に設定されるようになり、短時間で精度良
く排気温度を目標温度に上昇させることが可能となる。That is, in the invention of claim 4, the target air amount of the engine is set to a different value according to the presence or absence of the expansion stroke injection operation and the presence or absence of the exhaust throttle operation. For this reason, the intake air amount is set to an optimal value in accordance with the engine operating state during the particulate filter regeneration processing by the expansion stroke injection operation and the exhaust throttle operation, and the exhaust gas temperature can be accurately set in a short time. It is possible to raise the temperature.

【００１７】[0017]

【発明の実施の形態】以下、添付図面を用いて本発明の
実施形態について説明する。図１は、本発明のパティキ
ュレートフィルタ再生処理制御装置を自動車用ディーゼ
ル機関に適用した場合の概略構成を示す図である。図１
において、１は自動車用内燃機関を示す。本実施形態で
は機関１は４気筒ディーゼル機関とされ、各気筒には気
筒内に直接燃料を噴射する筒内燃料噴射弁１１１が設け
られている。燃料は高圧燃料噴射ポンプ１１３から各燃
料噴射弁１１１が接続されたコモンレール（蓄圧室）１
１５に圧送され、コモンレールから各燃料噴射弁１１１
により各気筒内に所定のタイミングで噴射される。Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration in a case where the particulate filter regeneration processing control device of the present invention is applied to an automobile diesel engine. FIG.
In the figures, 1 indicates an internal combustion engine for a vehicle. In the present embodiment, the engine 1 is a four-cylinder diesel engine, and each cylinder is provided with an in-cylinder fuel injection valve 111 that injects fuel directly into the cylinder. The fuel is supplied from a high-pressure fuel injection pump 113 to a common rail (accumulator) 1 to which each fuel injection valve 111 is connected.
15 from the common rail.
Accordingly, the fuel is injected into each cylinder at a predetermined timing.

【００１８】図１において２１は各気筒の吸気ポートを
吸気通路２に接続する吸気マニホルド、３１は各気筒の
排気ポートを排気通路３に接続する排気マニホルドであ
る。本実施形態では、機関１の過給を行なう過給機３５
が設けられており、排気通路３は過給機３５の排気出口
に、吸気通路２は過給機３５の吸気吐出口に、それぞれ
接続されている。また、吸気通路２には過給機３５から
供給される吸気の冷却を行なうインタークーラ２５及び
吸気絞り弁２７が設けられている。吸気絞り弁２７は、
後述するＥＣＵ３０からの信号に応じて作動するステッ
パモータ、負圧アクチュエータ等の適宜な形式のアクチ
ュエータ２７ａを備え、ＥＣＵ３０からの信号に応じた
開度をとり機関の吸気流量を制限する。また、過給機３
５下流側の排気通路３には、吸気絞り弁２７と同様なア
クチュエータ３７ａを備えた排気絞り弁３７が設けられ
ており、ＥＣＵ３０からの信号に応じた開度をとり排気
絞りを行なう。In FIG. 1, reference numeral 21 denotes an intake manifold connecting the intake port of each cylinder to the intake passage 2, and 31 denotes an exhaust manifold connecting the exhaust port of each cylinder to the exhaust passage 3. In the present embodiment, the supercharger 35 for supercharging the engine 1
The exhaust passage 3 is connected to an exhaust outlet of the supercharger 35, and the intake passage 2 is connected to an intake outlet of the supercharger 35. The intake passage 2 is provided with an intercooler 25 for cooling intake air supplied from the supercharger 35 and an intake throttle valve 27. The intake throttle valve 27 is
An appropriate type of actuator 27a, such as a stepper motor or a negative pressure actuator, which operates in response to a signal from the ECU 30, which will be described later, is provided with an opening corresponding to the signal from the ECU 30 to limit the intake flow rate of the engine. In addition, turbocharger 3
An exhaust throttle valve 37 provided with an actuator 37a similar to the intake throttle valve 27 is provided in the exhaust passage 3 on the downstream side of 5, and performs an exhaust throttle by setting an opening in accordance with a signal from the ECU 30.

【００１９】図１において、３３は機関排気系と吸気系
とを接続し機関排気の一部を吸気系に還流するＥＧＲ通
路、２３はＥＧＲ通路に配置されたＥＧＲ弁である。Ｅ
ＧＲ弁２３はステッパモータ、負圧アクチュエータ等の
適宜なアクチュエータ（図示せず）を備え、ＥＣＵ３０
からの信号に応じた開度をとりＥＧＲ通路３３を通って
吸気系に還流される排気（ＥＧＲガス）流量を機関運転
状態に応じて制御するものである。In FIG. 1, reference numeral 33 denotes an EGR passage which connects the engine exhaust system and the intake system and recirculates part of the engine exhaust to the intake system, and 23 denotes an EGR valve arranged in the EGR passage. E
The GR valve 23 includes an appropriate actuator (not shown) such as a stepper motor and a negative pressure actuator.
The opening degree corresponding to the signal from the ECU is taken, and the flow rate of exhaust gas (EGR gas) returned to the intake system through the EGR passage 33 is controlled in accordance with the engine operating state.

【００２０】本実施形態では、排気マニホルド３１を各
排気ポートに接続する排気枝管にはパティキュレートフ
ィルタ（ディーゼルパティキュレートフィルタ、以下
「ＤＰＦ」と称する）４０が設けられている。ＤＰＦ４
０は、セラミック、金属製不織布等の耐熱性を有する多
孔質の材質から形成され軸線方向（排気流れ方向）に排
気流路を形成する多数の流路を有している。これらの流
路のそれぞれは排気流れ方向上流端または下流端のうち
一方が閉塞されており、上流端が閉塞された流路と下流
端が閉塞された流路とが交互に互いに隣接して配置され
ている。このため、各気筒の排気ポートから排出される
排気は、それぞれのＤＰＦの上流端が開放された（下流
端が閉塞された）流路に流入し、流路相互を隔てる多孔
質の隔壁を通過して下流端が開放された流路に流入し下
流端からＤＰＦ外に流出する。排気中に含まれるパティ
キュレートは排気が多孔質の隔壁を通過する際に捕集さ
れる。In the present embodiment, a particulate filter (diesel particulate filter, hereinafter referred to as "DPF") 40 is provided in an exhaust branch pipe connecting the exhaust manifold 31 to each exhaust port. DPF4
Numeral 0 is formed of a heat-resistant porous material such as a ceramic or a metal nonwoven fabric, and has a large number of flow paths that form an exhaust flow path in the axial direction (the exhaust flow direction). Each of these flow paths is closed at one of the upstream end and the downstream end in the exhaust flow direction, and the flow path whose upstream end is closed and the flow path whose downstream end is closed are alternately arranged adjacent to each other. Have been. For this reason, the exhaust gas discharged from the exhaust port of each cylinder flows into the flow path in which the upstream end of each DPF is open (the downstream end is closed), and passes through the porous partition separating the flow paths. Then, the downstream end flows into the open flow path and flows out of the DPF from the downstream end. Particulates contained in the exhaust gas are collected when the exhaust gas passes through the porous partition.

【００２１】本実施形態では、比較的小容量のＤＰＦ４
０を各気筒の排気ポートに隣接して設けたことにより、
気筒からの高温の排気が直接ＤＰＦに流入するため各Ｄ
ＰＦ４０の温度を高く維持することができる。また、各
ＤＰＦ４０は小容量であるため、捕集可能なパティキュ
レート量も少なくなり後述するＤＰＦ再生操作の実行間
隔を比較的短く設定する必要があるが、熱容量が小さい
ため排気温度が上昇すると短時間でＤＰＦ温度が上昇し
パティキュレートの燃焼が開始される。また、パティキ
ュレート捕集量が少ないため短時間で捕集したパティキ
ュレートの燃焼を終了することができ、再生操作に要す
る時間を短縮することができる。本実施形態では、機関
１としてディーゼル機関が使用されているため、通常運
転時の機関排気温度は比較的低い。本実施形態では、小
容量のＤＰＦ４０を各気筒の排気ポートに配置する、い
わゆる分離型のＤＰＦを採用したことにより、加速時等
に短時間排気温度が上昇するような機関運転状態でも良
好に各ＤＰＦ４０の再生を完了することが可能となって
いる。In this embodiment, the DPF 4 having a relatively small capacity is used.
0 is provided adjacent to the exhaust port of each cylinder,
Because high-temperature exhaust from the cylinder flows directly into the DPF,
The temperature of the PF 40 can be kept high. Further, since each DPF 40 has a small capacity, the amount of particulates that can be collected is small, and it is necessary to set the execution interval of the DPF regeneration operation to be described later relatively short. Over time, the DPF temperature rises and particulate combustion starts. Further, since the amount of collected particulates is small, the combustion of the collected particulates can be completed in a short time, and the time required for the regeneration operation can be reduced. In this embodiment, since a diesel engine is used as the engine 1, the engine exhaust temperature during normal operation is relatively low. In the present embodiment, the so-called separation type DPF in which the small-capacity DPF 40 is disposed at the exhaust port of each cylinder is employed. The regeneration of the DPF 40 can be completed.

【００２２】図１に３０で示すのは機関１の電子制御ユ
ニット（ＥＣＵ）である。ＥＣＵ３０は、本実施形態で
はＲＡＭ、ＲＯＭ、ＣＰＵを備えた公知の構成のマイク
ロコンピュータとされ、機関１の燃料噴射制御等の基本
制御を行なう他、後述するように機関運転状態に応じて
ＤＰＦ４０の再生処理を制御する再生処理装置としての
機能を有している。In FIG. 1, reference numeral 30 denotes an electronic control unit (ECU) of the engine 1. In the present embodiment, the ECU 30 is a microcomputer having a known configuration including a RAM, a ROM, and a CPU. The ECU 30 performs basic control such as fuel injection control of the engine 1, and also controls the DPF 40 in accordance with the engine operating state as described later. It has a function as a playback processing device that controls playback processing.

【００２３】これらの制御を行なうため、ＥＣＵ３０の
入力ポートには、機関吸気通路に設けられたエアフロー
メータ５１から機関吸入空気量に対応した信号が、また
排気マニホルド３１に設けられた温度センサ５３から機
関排気温度に対応する信号がそれぞれ入力されている
他、機関クランク軸（図示せず）近傍に配置された回転
数センサ５５から機関クランク軸一定回転角毎にパルス
信号が入力されている。更に、本実施形態では、ＥＣＵ
３０の入力ポートには機関１のアクセルペダル（図示せ
ず）近傍に配置したアクセル開度センサ５７から運転者
のアクセルペダル踏込み量（アクセル開度）を表す信号
が入力されている。ＥＣＵ３０は、所定間隔毎にエアフ
ローメータ５１出力とアクセル開度センサ５７出力及び
温度センサ５３出力とをＡＤ変換して吸入空気量Ｇａと
アクセル開度ＡＣＣＰ、排気温度ＴとしてＥＣＵ３０の
ＲＡＭの所定領域に格納するとともに、回転数センサ５
５からのパルス信号の間隔から機関回転数ＮＥを算出
し、ＲＡＭの所定の領域に格納している。ＥＣＵ３０
は、アクセル開度センサ５７で検出されたアクセル開度
ＡＣＣＰと機関回転数ＮＥとに基づいて予めＲＯＭに格
納した関係に基づいて機関基本燃料噴射量と燃料噴射時
期を算出し、この基本燃料噴射量に機関運転状態に応じ
た補正を加えて機関の燃料噴射量ＱＩＪと燃料噴射時期
とを設定する。なお、本発明では燃料噴射量と燃料噴射
時期の設定方法には特に制限はなく、ディーゼル機関に
おける公知の方法のいずれをも使用することができる。To perform these controls, an input port of the ECU 30 receives a signal corresponding to the engine intake air amount from an air flow meter 51 provided in the engine intake passage and a temperature sensor 53 provided in the exhaust manifold 31 at an input port. A signal corresponding to the engine exhaust temperature is input, and a pulse signal is input from the rotation speed sensor 55 disposed near the engine crankshaft (not shown) at every constant rotation angle of the engine crankshaft. Further, in the present embodiment, the ECU
A signal representing the accelerator pedal depression amount (accelerator opening) of the driver is input to an input port 30 from an accelerator opening sensor 57 arranged near an accelerator pedal (not shown) of the engine 1. The ECU 30 converts the output of the air flow meter 51, the output of the accelerator opening sensor 57, and the output of the temperature sensor 53 at predetermined intervals into an A / D conversion of the intake air amount Ga, the accelerator opening ACCP, and the exhaust temperature T in a predetermined area of the RAM of the ECU 30. While storing, the rotation speed sensor 5
The engine speed NE is calculated from the interval of the pulse signal from the step 5 and stored in a predetermined area of the RAM. ECU 30
Calculates the engine basic fuel injection amount and the fuel injection timing based on the accelerator opening ACCP detected by the accelerator opening sensor 57 and the engine speed NE based on a relationship previously stored in the ROM. The fuel injection amount QIJ and the fuel injection timing of the engine are set by adding a correction according to the engine operating state to the amount. In the present invention, the method for setting the fuel injection amount and the fuel injection timing is not particularly limited, and any of the known methods for a diesel engine can be used.

【００２４】一方、ＥＣＵ３０の出力ポートは、各気筒
への燃料噴射量及び燃料噴射時期を制御するために、図
示しない燃料噴射回路を介して各気筒の燃料噴射弁１１
１に接続されている他、高圧燃料ポンプ１１３に図示し
ない駆動回路を介して接続され、ポンプ１１３からコモ
ンレール１１５への燃料圧送量を制御している。また、
ＥＣＵ３０の出力ポートは更に、それぞれ図示しない駆
動回路を介して吸気絞り弁２７のアクチュエータ２７
ａ、排気絞り弁３７のアクチュエータ３７ａ及びＥＧＲ
弁２３のアクチュエータに接続され、吸気絞り弁２７及
び排気絞り弁３７の開度とＥＧＲ弁２３を通過するＥＧ
Ｒガス量とをそれぞれ制御している。On the other hand, the output port of the ECU 30 is connected to a fuel injection valve 11 of each cylinder via a fuel injection circuit (not shown) to control the amount and timing of fuel injection into each cylinder.
1, and is connected to a high-pressure fuel pump 113 via a drive circuit (not shown) to control the amount of fuel pumped from the pump 113 to the common rail 115. Also,
The output port of the ECU 30 is further connected to an actuator 27 of the intake throttle valve 27 via a drive circuit (not shown).
a, Actuator 37a of exhaust throttle valve 37 and EGR
The opening degree of the intake throttle valve 27 and the exhaust throttle valve 37 and the EG passing through the EGR valve 23 are connected to the actuator of the valve 23.
The R gas amount is controlled.

【００２５】次に、本実施形態におけるＤＰＦ４０の再
生操作について説明する。本実施形態では、以下の操作
を単独または２つ以上組み合わせて実施することによ
り、機関の排気温度を上昇させＤＰＦ４０の再生を行な
う。 （Ａ）主燃料噴射時期の遅角 燃料噴射時期を遅角すると気筒内での燃料の燃焼時期が
遅くなるため膨張行程で充分に温度降下をしないまま比
較的高温の燃焼ガスが排気行程で排出されるようになり
排気温度が上昇する。主燃料噴射時期の遅角による排気
温度上昇は比較的小さいが、遅角実施による機関燃料消
費量の増大も比較的小さくなる。Next, the regeneration operation of the DPF 40 in this embodiment will be described. In the present embodiment, the following operation is performed alone or in combination of two or more, thereby increasing the exhaust gas temperature of the engine and regenerating the DPF 40. (A) Retardation of the main fuel injection timing Retarding the fuel injection timing delays the fuel combustion timing in the cylinder, so that relatively high temperature combustion gas is discharged in the exhaust stroke without sufficiently lowering the temperature in the expansion stroke. And the exhaust gas temperature rises. Although the exhaust gas temperature rise due to the retard of the main fuel injection timing is relatively small, the increase in engine fuel consumption due to the retard is also relatively small.

【００２６】（Ｂ）ＥＧＲ実施 ＥＧＲを実施すると、高温の排気ガスが気筒に吸入され
るようになる。また、ＥＧＲガス量に応じて気筒に吸入
される低温の新気の量が減少するため排気温度もそれに
応じて上昇する。本実施形態のディーゼル機関では通常
運転時も機関のほぼ全ての運転領域でＥＧＲを実施して
いるが、ＤＰＦ４０の再生操作を実施する際にはＥＧＲ
ガス量を更に増大して排気温度を通常の運転時より増大
させるようにしている。ＥＧＲガス量はＥＧＲ弁２３の
開度と吸気絞り弁２７の開度とにより決定される。吸気
絞り弁２７の開度を低減すると絞り弁下流側に負圧が発
生するため同一のＥＧＲ弁２３開度でもＥＧＲガス量は
増大し、大量のＥＧＲガスを吸気系に還流させることが
可能となる。(B) Performing EGR When the EGR is performed, high-temperature exhaust gas is drawn into the cylinder. Further, since the amount of low-temperature fresh air sucked into the cylinder decreases in accordance with the EGR gas amount, the exhaust temperature also increases accordingly. In the diesel engine of the present embodiment, EGR is performed in almost all operation regions of the engine even during normal operation, but when performing the regeneration operation of the DPF 40, EGR is performed.
The amount of gas is further increased so that the exhaust gas temperature is made higher than during normal operation. The EGR gas amount is determined by the opening of the EGR valve 23 and the opening of the intake throttle valve 27. If the opening degree of the intake throttle valve 27 is reduced, a negative pressure is generated on the downstream side of the throttle valve. Therefore, even with the same opening degree of the EGR valve 23, the EGR gas amount increases, and a large amount of EGR gas can be returned to the intake system. Become.

【００２７】（Ｃ）膨張行程燃料噴射 主燃料噴射に加えて各気筒の膨張行程中に燃料噴射を行
なうことにより排気温度は比較的大幅に上昇する。膨張
行程で噴射された燃料は気筒内で燃焼するが、大部分が
機関出力に変換されないまま高温の排気ガスとして気筒
から排出されるため、排気温度が上昇するようになる。
排気温度の上昇幅は膨張行程噴射における燃料噴射に応
じて変化する。また、膨張行程噴射では、燃料の燃焼エ
ネルギの一部は機械的仕事に変更されるため、機関出力
も膨張行程燃料噴射量に応じて増大する。このため、膨
張行程噴射を行なう際にはＥＧＲの増量（新気の低減）
や排気絞り等を行なって機関出力変化を抑制することが
好ましい。(C) Fuel injection during expansion stroke By performing fuel injection during the expansion stroke of each cylinder in addition to main fuel injection, the exhaust temperature rises relatively significantly. Although the fuel injected in the expansion stroke burns in the cylinder, most of the fuel is discharged from the cylinder as high-temperature exhaust gas without being converted into engine output, so that the exhaust gas temperature rises.
The rise width of the exhaust gas temperature changes according to the fuel injection in the expansion stroke injection. Further, in the expansion stroke injection, a part of the combustion energy of the fuel is changed to mechanical work, so that the engine output also increases according to the expansion stroke fuel injection amount. Therefore, when performing the expansion stroke injection, the amount of EGR is increased (reduction of fresh air).
It is preferable to suppress the change in the engine output by performing an exhaust throttle or the like.

【００２８】（Ｄ）排気絞り 排気絞り弁３７を所定開度まで閉弁することにより、絞
り弁３７での排気圧力損失が増大し機関出力は低下す
る。このため、排気絞りを実施することにより主燃料噴
射量の増量や膨張行程燃料噴射を行なって排気温度を上
昇させる場合の機関出力増大を抑制することができる。
従って、排気絞りとともに主燃料噴射量の増大または膨
張行程噴射を実行することにより、機関の運転性を大幅
に悪化させることなく排気温度を上昇させることが可能
となるが、排気圧力損失の増大により機関燃料消費の増
大幅は比較的大きくなる。(D) Exhaust throttle By closing the exhaust throttle valve 37 to a predetermined opening degree, the exhaust pressure loss at the throttle valve 37 increases and the engine output decreases. Therefore, it is possible to suppress an increase in the engine output when the exhaust throttle is performed to increase the main fuel injection amount or increase the exhaust temperature by performing the expansion stroke fuel injection.
Therefore, by executing the increase of the main fuel injection amount or the injection of the expansion stroke together with the exhaust throttle, it becomes possible to raise the exhaust temperature without greatly deteriorating the operability of the engine. The increase in engine fuel consumption is relatively large.

【００２９】本実施形態では、ＥＣＵ３０はＤＰＦ４０
に捕集されたパティキュレートの量を常時モニターして
おり、捕集されたパティキュレートの量が予め定めた量
に到達した場合には上記（Ａ）から（Ｄ）の再生操作の
いずれか１つ又は２つ以上を組合せて実施することによ
りＤＰＦ４０の再生を行なう。ＤＰＦ４０に捕集された
パティキュレート量は、例えばＤＰＦ４０の入口と出口
との差圧を検出することによっても算出可能であるが、
本実施形態ではＥＣＵ３０は機関運転状態に基づいて捕
集量カウンタを増減することによりパティキュレートの
捕集量を算出している。In the present embodiment, the ECU 30 includes the DPF 40
The amount of the collected particulates is constantly monitored, and when the amount of the collected particulates reaches a predetermined amount, one of the regeneration operations (A) to (D) is performed. The regeneration of the DPF 40 is performed by performing one or a combination of two or more. The amount of particulates collected in the DPF 40 can be calculated by, for example, detecting the pressure difference between the inlet and the outlet of the DPF 40,
In the present embodiment, the ECU 30 calculates the collection amount of the particulate by increasing or decreasing the collection amount counter based on the engine operating state.

【００３０】すなわち、機関におけるパティキュレート
の生成量は機関負荷状態（例えば機関燃料噴射量と回転
数）により定まる。そこで、本実施形態では、機関燃料
噴射量と回転数との組合せを変えて予め実際の機関を運
転し機関から単位時間当たりに排出されるパティキュレ
ートの量を実験的に求め、燃料噴射量と回転数とを用い
た数値テーブルの形でＥＣＵ３０のＲＯＭに格納してあ
る。ＥＣＵ３０は機関運転中一定時間毎に機関の燃料噴
射量と回転数とを用いて上記数値テーブルから単位時間
当たりのパティキュレート発生量を算出するとともに、
この発生量に予め定めた捕集率を乗じた値だけ捕集カウ
ンタを増大させる。これにより、捕集カウンタの値は機
関で生成するパティキュレートのうちＤＰＦ４０に捕集
される量を表すようになる。一方、機関の高負荷での運
転や再生操作の実行によりＤＰＦ４０温度が上昇すると
ＤＰＦに捕集されたパティキュレートは燃焼する。この
場合、単位時間当たりに燃焼するパティキュレートの量
は排気温度により定まる。このため、本実施形態では排
気温度センサ５３で検出した排気温度とＤＰＦ４０にお
ける単位時間当たりのパティキュレート燃焼量との関係
を予め実験的に求めておき、ＥＣＵ３０のＲＯＭに排気
温度を用いた数値テーブルの形で格納してある。ＥＣＵ
３０は上述のように機関のパティキュレート発生量に応
じて捕集カウンタの値を増大する操作を行なうととも
に、排気温度に基づいて上記数値テーブルからＤＰＦに
捕集されたパティキュレートの単位時間当たりの燃焼量
を算出し、捕集カウンタの値を算出された燃焼量だけ減
少させる。That is, the amount of particulates generated in the engine is determined by the engine load state (eg, engine fuel injection amount and engine speed). Therefore, in the present embodiment, the actual engine is operated in advance by changing the combination of the engine fuel injection amount and the number of revolutions, and the amount of particulates discharged per unit time from the engine is experimentally obtained. It is stored in the ROM of the ECU 30 in the form of a numerical table using the rotation speed. The ECU 30 calculates the amount of particulates generated per unit time from the numerical value table using the fuel injection amount and the rotation speed of the engine at regular intervals during the operation of the engine,
The collection counter is increased by a value obtained by multiplying the generated amount by a predetermined collection rate. As a result, the value of the collection counter indicates the amount collected by the DPF 40 among the particulates generated by the engine. On the other hand, when the temperature of the DPF 40 rises due to the high load operation of the engine or the execution of the regeneration operation, the particulates trapped in the DPF burn. In this case, the amount of particulates burned per unit time is determined by the exhaust gas temperature. For this reason, in the present embodiment, the relationship between the exhaust gas temperature detected by the exhaust gas temperature sensor 53 and the amount of particulate combustion per unit time in the DPF 40 is experimentally obtained in advance, and a numerical table using the exhaust gas temperature is stored in the ROM of the ECU 30. It is stored in the form of ECU
Numeral 30 performs an operation of increasing the value of the trapping counter in accordance with the amount of particulates generated by the engine as described above, and based on the exhaust gas temperature, the particulates collected in the DPF from the numerical value table per unit time. The combustion amount is calculated, and the value of the trap counter is reduced by the calculated combustion amount.

【００３１】すなわち、ＥＣＵ３０は機関運転中一定時
間毎に、ＤＰＦに捕集されたパティキュレート量だけ捕
集カウンタの値を増大させ、機関運転状態の変化や再生
操作実行によりＤＰＦ温度が上昇した場合にはＤＰＦ上
で燃焼するパティキュレート量だけ上記捕集カウンタの
値を減少させる。これにより、捕集カウンタの値は常に
ＤＰＦ４０内に存在するパティキュレートの量を正確に
表すようになる。That is, the ECU 30 increases the value of the collection counter by the amount of particulates collected in the DPF at regular intervals during the operation of the engine, and when the DPF temperature rises due to a change in the engine operation state or execution of the regeneration operation. , The value of the trapping counter is reduced by the amount of particulates burned on the DPF. As a result, the value of the collection counter always accurately represents the amount of particulates present in the DPF 40.

【００３２】前述のように、本実施形態では上記（Ａ）
から（Ｄ）の方法を用いてＤＰＦ４０の再生処理を行な
うため、燃料噴射量、噴射時期、ＥＧＲガス量等の各操
作量を機関運転条件と再生操作の種類に応じて制御する
必要がある。以下に、これらの操作量の制御方法につい
て幾つかの例を説明する。 （１）第１の実施形態 本実施形態では、前述の（Ａ）から（Ｄ）の方法を組み
合わせてＤＰＦ４０の再生操作を実施する際に、（Ｄ）
排気絞り操作を実施するか否かに応じて（Ａ）から
（Ｃ）の各操作量を決定するようにしている。As described above, in the present embodiment, (A)
Since the regeneration process of the DPF 40 is performed by using the methods (A) to (D), it is necessary to control each operation amount such as the fuel injection amount, the injection timing, and the EGR gas amount according to the engine operating conditions and the type of the regeneration operation. Hereinafter, some examples of the control method of these operation amounts will be described. (1) First Embodiment In the present embodiment, when the regeneration operation of the DPF 40 is performed by combining the above-described methods (A) to (D), (D)
Each of the operation amounts (A) to (C) is determined depending on whether or not the exhaust throttle operation is performed.

【００３３】前述のように、排気絞りを実施すると排気
圧力損失が増大するため、機関出力の増大を抑制しつつ
主燃料噴射量と膨張行程燃料噴射量とを大幅に増大する
ことが可能となる。ところが、排気絞りを実施した場合
には他の各操作量を排気絞りに応じて大幅に変更する必
要が生じる。例えば、排気絞りを行なうと排気圧力が上
昇するため、ＥＧＲ弁２３開度を同一にしていても吸気
系に還流するＥＧＲガス量は増大する。また、排気絞り
により機関吸入空気量も減少するため、燃焼に不安定が
生じたり機関出力の低下が生じることを防止するために
はＥＧＲガス量も吸入空気量の減少に応じて最適な値に
制御する必要がある。また、短時間で排気温度を最適な
値に上昇させるためには、主燃料噴射の燃料噴射量や噴
射時期、膨張行程噴射の噴射量、噴射時期も排気絞りに
応じて変更する必要がある。As described above, when the exhaust throttle is performed, the exhaust pressure loss increases. Therefore, it is possible to greatly increase the main fuel injection amount and the expansion stroke fuel injection amount while suppressing an increase in the engine output. . However, when the exhaust throttle is performed, it is necessary to significantly change other operation amounts according to the exhaust throttle. For example, when the exhaust throttle is performed, the exhaust pressure increases, so that the amount of the EGR gas recirculated to the intake system increases even when the EGR valve 23 has the same opening. In addition, since the exhaust throttle also reduces the engine intake air amount, the EGR gas amount is also set to an optimal value in accordance with the decrease in the intake air amount in order to prevent instability in combustion and reduction in engine output. You need to control. Further, in order to raise the exhaust temperature to an optimum value in a short time, it is necessary to change the fuel injection amount and the injection timing of the main fuel injection, the injection amount and the injection timing of the expansion stroke injection according to the exhaust throttle.

【００３４】本実施形態ではＤＰＦ４０の再生操作実行
時の主燃料噴射の燃料噴射量や噴射時期、膨張行程噴射
の噴射量、噴射時期、ＥＧＲガス量等の各操作量は機関
運転状態（負荷状態）に応じて決定されるが、上記のよ
うに排気絞りを実施するか否かにより同一の機関運転状
態（機関負荷）であってもに排気絞り操作を実施するか
否かに応じてこれらの操作量を変化させる必要がある。
そこで、本実施形態では、再生操作実行時に排気絞りを
実施する場合と実施しない場合とで別々の関係に基づい
て機関運転状態から各操作量を決定するようにしてい
る。In this embodiment, when the regeneration operation of the DPF 40 is executed, the respective operation amounts such as the fuel injection amount and the injection timing of the main fuel injection, the injection amount of the expansion stroke injection, the injection timing, and the EGR gas amount are changed according to the engine operating state (load state). ) Is determined according to whether or not to perform the exhaust throttle operation as described above, depending on whether or not to perform the exhaust throttle operation even in the same engine operating state (engine load). It is necessary to change the operation amount.
Thus, in the present embodiment, each operation amount is determined from the engine operating state based on a different relationship between when the exhaust throttle is performed and when the exhaust throttle is not performed during the execution of the regeneration operation.

【００３５】具体的には、本実施形態では予め機関を負
荷条件（例えば燃料噴射量ＱＩＪと回転数ＮＥ）を変え
て運転して、ＤＰＦ４０再生操作に最適な排気温度を得
るのに必要な各操作量を求めておき、それぞれの操作量
をＱＩＪとＮＥとをパラメータとして用いた図２の形式
の数値マップの形でＥＣＵ３０のＲＯＭに格納してあ
り、ＤＰＦ４０再生操作時には現在のＱＩＪとＮＥとの
値から各操作量をこれらの数値マップを用いて決定する
が、これらの数値マップはそれぞれについて排気絞りを
実施する再生操作を行なった場合と、排気絞りを実施し
ない再生操作を行なった場合との２組が準備されてい
る。本実施形態では、再生操作実施時に上記準備した数
値マップのなかから、排気絞り実施の有無に応じて異な
るマップを用いて各操作量を決定することにより、それ
ぞれの場合に最適な操作量を得るようにしている。Specifically, in the present embodiment, the engine is operated in advance with changing the load conditions (for example, the fuel injection amount QIJ and the rotational speed NE) to obtain the optimum exhaust gas temperature necessary for the DPF 40 regeneration operation. The operation amounts are obtained, and the respective operation amounts are stored in the ROM of the ECU 30 in the form of a numerical map in the form of FIG. 2 using QIJ and NE as parameters, and the current QIJ, NE and The operation amounts are determined from these values using these numerical maps.These numerical maps include a case where a regeneration operation is performed for each of the exhaust throttles and a case where a regeneration operation is performed for which the exhaust throttle is not performed. Are prepared. In the present embodiment, the optimal operation amount is obtained in each case by determining each operation amount from the numerical maps prepared at the time of performing the regeneration operation, using different maps depending on whether or not the exhaust throttle is performed. Like that.

【００３６】図３は、本実施形態の上述した再生操作実
施時の各操作量の決定を具体的に説明するフローチャー
トである。本操作はＥＣＵ３０により一定時間毎に実行
されるルーチンにより行なわれる。図３において操作が
スタートすると、ステップ３０１では再生操作実行条件
が成立しているか否かについての判断が行なわれる。前
述したように、本実施形態ではＥＣＵ３０は機関運転中
ＤＰＦ４０に捕集されたパティキュレート量を捕集カウ
ンタを用いて常時監視している。そして、捕集カウンタ
の値が予め定めた値まで増大すると再生操作実行条件が
成立したと判断するとともに、再生操作実行等によりパ
ティキュレートが燃焼して捕集カウンタの値が０付近の
所定値以下になったときには再生操作実行条件を不成立
とする判断を行なっている。FIG. 3 is a flowchart for specifically explaining the determination of each operation amount at the time of performing the above-described reproduction operation of the present embodiment. This operation is performed by a routine executed by the ECU 30 at regular intervals. When the operation is started in FIG. 3, in step 301, it is determined whether or not the reproduction operation execution condition is satisfied. As described above, in the present embodiment, the ECU 30 constantly monitors the amount of particulates collected by the DPF 40 during operation of the engine using the collection counter. When the value of the collection counter increases to a predetermined value, it is determined that the regeneration operation execution condition has been satisfied, and the particulates burn due to the execution of the regeneration operation and the value of the collection counter is equal to or less than a predetermined value near 0. Is determined, the reproduction operation execution condition is not satisfied.

【００３７】ステップ３０１で再生操作実行条件が成立
していない場合には、本操作はそのまま終了し、ステッ
プ３０３以下の操作は行なわれない。この場合には、排
気絞り操作と膨張行程噴射は実行されず、主燃料噴射
量、噴射時期、ＥＧＲガス量は通常の制御により決定さ
れる。ステップ３０１で再生操作実行条件が成立してい
た場合には、次いでステップ３０３で主燃料噴射量ＱＩ
Ｊと機関回転数ＮＥとが読み込まれる。本実施形態で
は、前述したように主燃料噴射量ＱＩＪは機関回転数Ｎ
Ｅとアクセル開度ＡＣＣＰとに基づいて別途算出され
る。本操作では、ＱＩＪとＮＥとは機関運転状態（負荷
状態）を代表するパラメータとして用いられる。If the reproduction operation execution condition is not satisfied in step 301, this operation is terminated as it is, and the operation after step 303 is not performed. In this case, the exhaust throttle operation and the expansion stroke injection are not performed, and the main fuel injection amount, the injection timing, and the EGR gas amount are determined by ordinary control. If the regeneration operation execution condition is satisfied in step 301, then in step 303 the main fuel injection amount QI
J and the engine speed NE are read. In the present embodiment, as described above, the main fuel injection amount QIJ is the engine speed N
It is separately calculated based on E and the accelerator opening ACCP. In this operation, QIJ and NE are used as parameters representing the engine operating state (load state).

【００３８】次いで、ステップ３０５では上記により読
み込んだＱＩＪとＮＥとから現在機関が再生操作時に排
気絞りを行なう必要がある領域で運転されているか否か
が判定される。排気絞り操作は燃費の比較的大幅な増大
を生じさせるため、本実施形態では機関の負荷が比較的
低く排気温度を大幅に上昇させなければＤＰＦ４０の再
生を行なうことができない運転領域でのみ実施するよう
にしている。Next, in step 305, it is determined from the QIJ and NE read as described above whether or not the engine is currently operating in a region where exhaust throttling must be performed during a regeneration operation. Since the exhaust throttle operation causes a relatively large increase in fuel efficiency, in the present embodiment, the exhaust throttle operation is performed only in an operation region where regeneration of the DPF 40 cannot be performed unless the load on the engine is relatively low and the exhaust temperature is significantly increased. Like that.

【００３９】ステップ３０５で現在排気絞りが必要とさ
れる場合には、次にステップ３０７で現在の機関負荷状
態（ＱＩＪ、ＮＥ）とに基づいて予め定めた関係から排
気絞りの程度（排気絞り弁３７開度）が決定される。排
気絞り弁開度は機関負荷状態に応じて連続的に変化させ
ても良いが、本実施形態では制御の簡素化のために、排
気絞り弁開度を全開、半開（５０パーセント開度）、全
閉の３段階に制御しており、ステップ３０７では、排気
絞り弁開度がＱＩＪとＮＥとの値に基づいて全開または
半開のいずれかに設定される。If the current exhaust throttle is required in step 305, then in step 307, the degree of exhaust throttle (exhaust throttle valve) is determined from a predetermined relationship based on the current engine load condition (QIJ, NE). 37 degrees). The exhaust throttle valve opening may be continuously changed according to the engine load state. However, in this embodiment, the exhaust throttle valve opening is fully opened, half opened (50% opening), Control is performed in three stages of full closing, and in step 307, the exhaust throttle valve opening is set to either full opening or half opening based on the values of QIJ and NE.

【００４０】ステップ３０９は主燃料噴射量の補正量
（増量）の算出操作を示す。ステップ３０９では、予め
排気絞り実施時の機関運転結果に基づいて作成された図
２の形式の数値マップから、ＱＩＪとＮＥとの値に基づ
いて補正量が決定される。排気絞り実施時には、排気絞
りを実施しない場合に較べて主燃料噴射量を大幅に増量
することが可能である。従って、ステップ３０９では主
燃料噴射量の増量幅は比較的大きな値に設定される。再
生操作時には実際の主燃料噴射量はＱＩＪにステップ３
０９で算出された補正量を加えた値に設定される。Step 309 shows the operation of calculating the correction amount (increase) of the main fuel injection amount. In step 309, a correction amount is determined based on the values of QIJ and NE from a numerical map in the form of FIG. 2 created in advance based on the engine operation result when the exhaust throttle is performed. At the time of performing the exhaust throttling, it is possible to greatly increase the main fuel injection amount as compared with a case where the exhaust throttling is not performed. Accordingly, in step 309, the increase width of the main fuel injection amount is set to a relatively large value. During the regeneration operation, the actual main fuel injection amount is set to QIJ in step 3.
09 is set to a value obtained by adding the correction amount calculated.

【００４１】また、ステップ３１１では主燃料噴射の噴
射時期が、同様に予め排気絞り実施時の機関運転結果に
基づいて作成された図２の形式の数値マップからＱＩＪ
とＮＥとの値に基づいて決定される。更に、ステップ３
１３と３１５、及び３１７では、膨張行程噴射の燃料噴
射量と噴射時期及びＥＧＲガス量が排気絞り実施時の機
関運転結果に基づいてそれぞれ作成された図２の形式の
数値マップからＱＩＪとＮＥとの値を用いて決定され
る。なお、ＥＧＲガス量は排気絞りによる新気吸入量の
低下に応じて排気絞りを実施しない場合より小さな値に
設定される。Further, in step 311, the injection timing of the main fuel injection is determined from the numerical map of the form shown in FIG. 2 similarly based on the engine operation result when the exhaust throttle is performed.
And NE. Step 3
13, 315, and 317, the fuel injection amount, the injection timing, and the EGR gas amount of the expansion stroke injection are obtained from the numerical maps of the format of FIG. Is determined using the value of It should be noted that the EGR gas amount is set to a smaller value in accordance with a decrease in the fresh air intake amount due to the exhaust throttle than when the exhaust throttle is not performed.

【００４２】ステップ３１９は各操作量の値を上記によ
り設定された値に制御する制御操作を示す。ステップ３
１９では、排気絞り弁３７の開度がステップ３０７で設
定された開度になるように制御される。また、各気筒の
燃料噴射弁１１１の開弁期間と開弁時期とが補正後の主
燃料噴射量と噴射時期になるように設定され、さらに各
気筒の膨張行程でステップ３１３と３１５により設定し
た膨張行程噴射量と噴射時期での燃料噴射を行うように
設定される。また、吸気絞り弁２７開度とＥＧＲ弁２３
開度とはステップ３１７で設定したＥＧＲガス量が得ら
れる開度に設定される。一方、ステップ３０５で再生操
作実行時に機関が排気絞りの必要のない運転領域で運転
されていた場合には、ステップ３２１から３２９でステ
ップ３０９から３１７と同様な操作により主燃料噴射量
補正量、主燃料噴射時期、膨張行程噴射量と噴射時期及
びＥＧＲガス量が決定される。この場合には、各ステッ
プでは予め排気絞りを実施しない機関運転結果から得ら
れた図２の形式の数値マップに基づいて、現在のＱＩＪ
とＮＥとの値から各操作量が決定される。また、ステッ
プ３３１ではステップ３１９と同様に燃料噴射弁と吸気
絞り弁２７及びＥＧＲ弁２３の制御が行われるが、排気
絞り弁３７開度は全開に維持される。Step 319 shows a control operation for controlling the value of each operation amount to the value set as described above. Step 3
In 19, the opening degree of the exhaust throttle valve 37 is controlled so as to become the opening degree set in step 307. Further, the valve opening period and the valve opening timing of the fuel injection valve 111 of each cylinder are set so as to be the corrected main fuel injection amount and the injection timing, and are set in steps 313 and 315 in the expansion stroke of each cylinder. It is set so as to perform fuel injection at the expansion stroke injection amount and the injection timing. Further, the opening degree of the intake throttle valve 27 and the EGR valve 23
The opening is set to an opening at which the EGR gas amount set in step 317 is obtained. On the other hand, if the engine has been operating in the operating region where the exhaust throttle is not required at the time of executing the regeneration operation in step 305, the main fuel injection amount correction amount and the main fuel injection amount correction amount are determined in steps 321 to 329 by the same operation as in steps 309 to 317. The fuel injection timing, the expansion stroke injection amount and the injection timing, and the EGR gas amount are determined. In this case, in each step, the current QIJ is determined based on a numerical map of the type shown in FIG.
Each operation amount is determined from the values of NE and NE. In step 331, the fuel injection valve, the intake throttle valve 27, and the EGR valve 23 are controlled in the same manner as in step 319, but the exhaust throttle valve 37 is kept fully open.

【００４３】上記のように、本実施形態では排気絞りの
実施の有無に応じて各操作量を設定するようにしたこと
により、排気絞り実施時には短時間で正確に目標の排気
温度を得ることが可能となる。なお、実際の運転では排
気絞り弁３７の作動遅れ時間があるため、排気絞り弁開
度調整時に設定した排気絞りが得られるまでに遅れ時間
が生じる場合がある。このため、ステップ３１９で主燃
料噴射や膨張行程噴射及びＥＧＲを設定値に制御する際
には排気絞り弁３７の作動速度に合わせて徐々にこれら
の操作量を変化させるようにしても良い。As described above, in this embodiment, the respective operation amounts are set in accordance with the presence or absence of the execution of the exhaust throttling, so that the target exhaust temperature can be accurately obtained in a short time when the exhaust throttling is performed. It becomes possible. In the actual operation, there is a delay in the operation of the exhaust throttle valve 37, and thus a delay may occur before the exhaust throttle set at the time of adjusting the exhaust throttle valve opening is obtained. For this reason, when controlling the main fuel injection, the expansion stroke injection, and the EGR to the set values in step 319, the operation amounts thereof may be gradually changed in accordance with the operation speed of the exhaust throttle valve 37.

【００４４】（２）第２の実施形態 本実施形態では、膨張行程噴射操作によりＤＰＦ４０の
再生処理を行う。また、前述したように本実施形態の機
関では機関のほぼ全運転領域でＥＧＲが実施されてい
る。ＥＧＲを実施すると高温の排気ガスが吸気系に還流
されるとともに、新気の吸入量が低下するため排気温度
は上昇する。このため、膨張行程噴射操作実施時にもＥ
ＧＲ操作を継続することにより、排気温度の上昇幅を大
きくすることができる。(2) Second Embodiment In this embodiment, the regeneration process of the DPF 40 is performed by the expansion stroke injection operation. Further, as described above, in the engine of the present embodiment, EGR is performed in almost the entire operation range of the engine. When EGR is performed, high-temperature exhaust gas is recirculated to the intake system, and the intake temperature of fresh air decreases, so that the exhaust temperature rises. For this reason, even when the expansion stroke injection operation is performed, E
By continuing the GR operation, the range of increase in the exhaust gas temperature can be increased.

【００４５】ところが、膨張行程噴射を行うと排気の有
するエネルギが増大するためターボチャージャ等を有す
る機関では過給機の仕事が増加してしまい、過給圧が上
昇するために膨張行程噴射を実施しない場合に較べて機
関に吸入される新気の量が増大してしまう場合がある。
新気流量が増大した状態で排気温度を所望の温度まで上
昇させるためには、新気増大量に応じた量だけ膨張行程
燃料噴射量を増大させる必要が生じ燃料消費率が大きく
なる。そこで、本実施形態では膨張行程噴射とともにＥ
ＧＲ操作を行う場合には、膨張行程操作を実施しない場
合に較べて機関負荷が同一であってもＥＧＲガス量を増
大させるようにしている。これにより、膨張行程噴射に
よる新気流量の増大が抑制され、燃料消費率の増大が防
止される。However, when the expansion stroke injection is performed, the energy of the exhaust gas increases, so the work of the turbocharger increases in an engine having a turbocharger or the like, and the expansion stroke injection is performed because the supercharging pressure increases. In some cases, the amount of fresh air sucked into the engine may be increased as compared with the case where the engine is not operated.
In order to raise the exhaust gas temperature to a desired temperature with the fresh air flow rate increased, it is necessary to increase the expansion stroke fuel injection amount by an amount corresponding to the fresh air increase amount, and the fuel consumption rate increases. Thus, in the present embodiment, E is added together with the expansion stroke injection.
When performing the GR operation, the EGR gas amount is increased even if the engine load is the same, as compared with the case where the expansion stroke operation is not performed. Thus, an increase in the fresh air flow rate due to the expansion stroke injection is suppressed, and an increase in the fuel consumption rate is prevented.

【００４６】図４は上記再生操作におけるＥＧＲガス量
制御を具体的に説明するフローチャートである。本操作
はＥＣＵ３０により一定時間毎に実行されるルーチンに
より行われる。図４ステップ４０１では現在再生操作実
行条件が成立しているか否かが判断される。ステップ４
０１の判断は、図３ステップ３０１と同一の方法で行わ
れる。現在再生操作実行条件が成立している場合には、
次にステップ４０３で機関燃料噴射量ＱＩＪと機関回転
数ＮＥとが読み込まれ、ステップ４０５では現在機関が
膨張行程噴射によりＤＰＦ４０の再生処理を行うべき負
荷条件で運転されているか否かが判定される。例えば、
本実施形態では機関負荷が高く排気温度が比較的高いよ
うな領域で機関が運転されている場合には、膨張行程噴
射によるＤＰＦ４０の再生は実施せず、別途ＥＣＵ３０
により実行される他の操作により、別の方法（例えば主
燃料噴射時期遅角等）によるＤＰＦ４０の再生処理が実
施される。FIG. 4 is a flow chart for specifically explaining the EGR gas amount control in the regeneration operation. This operation is performed by a routine executed by the ECU 30 at regular intervals. In step 401 of FIG. 4, it is determined whether or not the reproduction operation execution condition is currently satisfied. Step 4
The determination of 01 is made in the same manner as in step 301 of FIG. If the playback operation execution condition is currently satisfied,
Next, at step 403, the engine fuel injection amount QIJ and the engine speed NE are read, and at step 405, it is determined whether or not the engine is currently operating under a load condition in which the regeneration process of the DPF 40 should be performed by the expansion stroke injection. . For example,
In the present embodiment, when the engine is operated in a region where the engine load is high and the exhaust temperature is relatively high, the regeneration of the DPF 40 by the expansion stroke injection is not performed, and the ECU 30 is separately provided.
The regeneration process of the DPF 40 is performed by another method (for example, the main fuel injection timing is retarded) by the other operation executed by.

【００４７】ステップ４０５で膨張行程噴射によりＤＰ
Ｆ４０の再生を行う場合には、次にステップ４０７で膨
張行程噴射における燃料噴射量と噴射時期とが機関負荷
状態に応じて決定される。本実施形態では、予め排気温
度を目標値まで上昇させるのに最適な膨張行程燃料噴射
量と噴射時期とが各機関負荷条件（ＱＩＪ、ＮＥ）毎に
実験により求められ、ＱＩＪとＮＥとをパラメータとし
て用いた図２の形式の数値マップとしてＥＣＵ３０のＲ
ＯＭに格納されており、ステップ４０７ではＱＩＪとＮ
Ｅとの値を用いてこの数値マップから膨張行程燃料噴射
量と噴射時期とが設定される。In step 405, DP is obtained by the expansion stroke injection.
When the regeneration of F40 is performed, next, at step 407, the fuel injection amount and the injection timing in the expansion stroke injection are determined according to the engine load state. In the present embodiment, the optimum expansion stroke fuel injection amount and injection timing for raising the exhaust gas temperature to the target value are obtained in advance for each engine load condition (QIJ, NE) by experiments, and QIJ and NE are set as parameters. As a numerical map in the form of FIG.
In step 407, the QIJ and N
The expansion stroke fuel injection amount and the injection timing are set from this numerical map using the value of E.

【００４８】次いで、ステップ４０９では膨張行程噴射
操作実施時のＥＧＲ補正量（増量）が算出される。本実
施形態では、膨張行程噴射実施時に必要とされるＥＧＲ
ガス増大量は、予め実験により求められており、ＱＩＪ
とＮＥとを用いた図２の形式の数値マップの形でＥＣＵ
３０のＲＯＭに格納されている。ステップ４０９ではこ
の数値マップを用いてＱＩＪとＮＥとの値からＥＧＲの
補正量が決定される。Next, at step 409, the EGR correction amount (increase) when the expansion stroke injection operation is performed is calculated. In the present embodiment, the EGR required when the expansion stroke injection is performed
The amount of gas increase is determined in advance by an experiment,
ECU in the form of a numerical map in the form of FIG.
30 are stored in the ROM. In step 409, the EGR correction amount is determined from the values of QIJ and NE using this numerical map.

【００４９】ステップ４１１では、上記により決定され
た膨張行程噴射の燃料噴射量と噴射時期とが燃料噴射回
路にセットされるとともに、ステップ４１３ではＥＧＲ
ガス量の増量が実施される。前述したように、ＥＧＲガ
ス量の増量補正は、ＥＧＲ弁２３の開度増大または吸気
絞り弁２７の開度低減のいずれか一方または両方の操作
を行うことにより実施される。これにより、膨張行程噴
射操作を実施する場合には実施しない場合に較べてＥＧ
Ｒガス量が増大され、膨張行程噴射の燃料噴射量の増大
が抑制される。In step 411, the fuel injection amount and the injection timing of the expansion stroke injection determined as described above are set in the fuel injection circuit, and in step 413, the EGR
The gas amount is increased. As described above, the increase correction of the EGR gas amount is performed by performing one or both operations of increasing the opening degree of the EGR valve 23 and decreasing the opening degree of the intake throttle valve 27. As a result, when the expansion stroke injection operation is performed, the EG is higher than when the expansion stroke injection operation is not performed.
The R gas amount is increased, and an increase in the fuel injection amount of the expansion stroke injection is suppressed.

【００５０】（３）第３の実施形態 本実施形態では、膨張行程噴射操作と排気絞り操作との
いずれか一方または両方の操作を行うことによりＤＰＦ
４０の再生を行う。ところが、前述したように、膨張行
程噴射操作と排気絞り操作との両方を同時に実行すると
排気圧力が大幅に上昇してしまい、ＥＧＲ弁２３開度の
わずかな変化でもＥＧＲガス量が大きく変化するように
なるためＥＧＲガス量が過大になって機関の失火を生じ
る場合がある。そこで、本実施形態では膨張行程噴射操
作と同時に排気絞り操作を行う場合にはＥＧＲ弁２３を
全閉にして排気の再循環を停止するようにして機関の失
火を防止する。(3) Third Embodiment In this embodiment, the DPF is performed by performing one or both of the expansion stroke injection operation and the exhaust throttle operation.
40 is reproduced. However, as described above, if both the expansion stroke injection operation and the exhaust throttle operation are performed at the same time, the exhaust pressure greatly increases, and even a small change in the opening degree of the EGR valve 23 greatly changes the EGR gas amount. Therefore, the EGR gas amount becomes excessively large, which may cause a misfire of the engine. Therefore, in the present embodiment, when performing the exhaust throttle operation simultaneously with the expansion stroke injection operation, the EGR valve 23 is fully closed to stop the exhaust gas recirculation, thereby preventing the engine from misfiring.

【００５１】図５は、本実施形態の上述したＥＧＲガス
量制御操作を具体的に説明するフローチャートである。
図５の操作はＥＣＵ３０により一定時間毎に実行される
ルーチンにより行われる。図５において操作がスタート
すると、ステップ５０１では機関負荷条件（燃料噴射量
ＱＩＪ、回転数ＮＥ）が読み込まれ、ステップ５０３で
は現在ＤＰＦ４０の再生操作実行条件が成立しているか
否かが判定される。この判定は図３ステップ３０１、図
４ステップ４０１と同様に別途算出されるパティキュレ
ート捕集カウンタの値に基づいて行われる。FIG. 5 is a flowchart specifically illustrating the above-described EGR gas amount control operation of the present embodiment.
5 is performed by a routine executed by the ECU 30 at regular intervals. When the operation starts in FIG. 5, the engine load condition (fuel injection amount QIJ, rotation speed NE) is read in step 501, and in step 503, it is determined whether the regeneration operation execution condition of the DPF 40 is currently satisfied. This determination is made based on the value of the particulate collection counter separately calculated in the same manner as in step 301 in FIG. 3 and step 401 in FIG.

【００５２】ステップ５０３で再生操作実行条件が成立
している場合には、次いでステップ５０５で現在機関が
膨張行程噴射操作によりＤＰＦ４０の再生処理を行うべ
き運転領域で運転されているか否かが機関負荷条件（Ｑ
ＩＪ、ＮＥ）に基づいて判断される。ステップ５０３で
再生操作実行条件が成立していない場合、及びステップ
５０５で膨張行程噴射を実施しない運転領域（例えば主
燃料噴射の遅角により再生操作を行う運転領域）である
場合には、ステップ５１１が実行され、ＥＧＲガス量が
機関負荷条件（ＱＩＪ、ＮＥ）に基づいて予め準備され
た通常運転時の図２の形式の数値マップから算出され
る。すなわち、この場合にはＥＧＲガス量は通常運転時
の値に設定される。If the regeneration operation execution condition is satisfied in step 503, then in step 505, it is determined whether or not the engine is currently operating in the operation region in which the regeneration process of the DPF 40 is to be performed by the expansion stroke injection operation. Condition (Q
IJ, NE). If the regeneration operation execution condition is not satisfied in step 503, or if the operation region is in the operation region in which the expansion stroke injection is not performed in step 505 (for example, the operation region in which the regeneration operation is performed by retarding the main fuel injection), step 511 is executed. Is executed, and the EGR gas amount is calculated from a numerical map in the form of FIG. 2 during normal operation prepared in advance based on the engine load condition (QIJ, NE). That is, in this case, the EGR gas amount is set to the value during normal operation.

【００５３】また、ステップ５０５で膨張行程噴射操作
を行うべき領域で機関が運転されている場合には、次に
ステップ５０７で膨張行程噴射操作と排気絞り操作とを
同時に実行すべき領域で機関が運転されているか否かが
機関負荷条件に基づいて判定され、排気絞り操作を実行
しない場合、すなわち膨張行程噴射操作のみによりＤＰ
Ｆ４０の再生処理を行う運転領域である場合にはステッ
プ５１３に進み、予め準備された膨張行程噴射実施時の
数値マップに基づいてＥＧＲガス量が設定される。本実
施形態においても膨張行程噴射実施時には通常運転時に
較べてＥＧＲガス量は大きな値に設定される。If the engine is operating in the region where the expansion stroke injection operation is to be performed in step 505, then in step 507 the engine is operated in the region where the expansion stroke injection operation and the exhaust throttle operation are to be performed simultaneously. It is determined based on the engine load condition whether or not the engine is being operated. If the exhaust throttle operation is not performed, that is, the DP
If it is the operating range in which the regeneration process of F40 is performed, the process proceeds to step 513, and the EGR gas amount is set based on a numerical map prepared when the expansion stroke injection is performed. Also in the present embodiment, the EGR gas amount is set to a larger value during the expansion stroke injection than during the normal operation.

【００５４】一方、ステップ５０７で現在膨張行程噴射
操作と排気絞り操作との両方を実施すべき領域で機関が
運転されている場合には、次にステップ５０９に進み、
ＥＧＲ制御弁２３は全閉とされてＥＧＲ操作は停止され
る。これにより、ＥＧＲガス量の制御性悪化による機関
の失火が生じることが防止される。 （４）第４の実施形態 本実施形態では、上記第３の実施形態と同様に、膨張行
程噴射操作と排気絞り操作とのいずれか一方または両方
を実施することによりＤＰＦ４０の再生処理を行う際
に、膨張行程噴射操作実施の有無に応じて、また、膨張
行程噴射操作実施時には更に排気絞り操作実施の有無に
応じて異なる値に機関の目標吸入空気量（新気量）を設
定する。On the other hand, if it is determined in step 507 that the engine is currently operating in the region where both the expansion stroke injection operation and the exhaust throttle operation are to be performed, the process proceeds to step 509, and
The EGR control valve 23 is fully closed, and the EGR operation is stopped. This prevents the engine from misfiring due to the deterioration of the controllability of the EGR gas amount. (4) Fourth Embodiment In the present embodiment, as in the third embodiment, the regeneration process of the DPF 40 is performed by performing one or both of the expansion stroke injection operation and the exhaust throttle operation. Then, the target intake air amount (new air amount) of the engine is set to a different value depending on whether the expansion stroke injection operation is performed, and when the expansion stroke injection operation is performed, further depending on whether the exhaust throttle operation is performed.

【００５５】例えば、前述したように膨張行程噴射を実
施すると通常運転時に較べて過給圧が上昇するため吸入
空気量は増大する。また、膨張行程噴射により噴射され
た燃料を燃焼させて排気温度を上昇させるためには通常
運転時より多い吸入空気量が必要となる。このため、膨
張行程噴射操作実施の有無に応じて最適な吸入空気量は
変化する。For example, as described above, when the expansion stroke injection is performed, the supercharging pressure increases compared to the normal operation, so that the intake air amount increases. Further, in order to raise the exhaust gas temperature by burning the fuel injected by the expansion stroke injection, a larger intake air amount is required than during normal operation. For this reason, the optimum intake air amount changes depending on whether or not the expansion stroke injection operation is performed.

【００５６】また、膨張行程噴射実施時に排気絞り操作
を同時に実行する場合には、第３の実施形態で説明した
ようにＥＧＲガス量が過大になりやすいため、ＥＧＲガ
ス量を通常より低減またはＥＧＲ操作を停止する必要が
ある。この場合、排気絞り操作中であっても吸入空気量
はＥＧＲガス量の減少分だけ増大することになる。ま
た、排気絞り実施とともに増量された噴射量の燃料を燃
焼させて排気温度を上昇させるためには適切な量の吸入
空気が必要となる。このため、膨張行程噴射操作実施時
においても排気絞り操作実施の有無に応じて最適な吸入
空気量は変化することになる。When the exhaust throttle operation is performed simultaneously during the expansion stroke injection, the EGR gas amount tends to be excessive as described in the third embodiment. Operation must be stopped. In this case, even during the operation of the exhaust throttle, the intake air amount increases by the decrease of the EGR gas amount. Further, in order to raise the exhaust gas temperature by burning the increased injection amount of fuel together with the execution of the exhaust throttle, an appropriate amount of intake air is required. For this reason, even when the expansion stroke injection operation is performed, the optimum intake air amount changes depending on whether the exhaust throttle operation is performed.

【００５７】本実施形態では、通常運転時（膨張行程噴
射操作を実施しない場合）、膨張行程噴射操作のみを実
施した場合、及び膨張行程噴射操作と排気絞り操作との
両方を実施した場合について、予め機関の負荷条件（燃
料噴射量ＱＩＪ、回転数ＮＥ）を変えて実験を行い最適
な吸入空気量（目標吸入空気量）を求めておき、それぞ
れの場合についてＱＩＪとＮＥとを用いた図２の形式の
数値マップとしてＥＣＵ３０のＲＯＭに格納してある。
そして、機関運転中膨張行程噴射操作の有無及び排気絞
り操作の有無に応じてそれぞれ該当する数値マップを用
いて機関負荷条件に基づいて目標吸入空気量を算出す
る。In this embodiment, during normal operation (when the expansion stroke injection operation is not performed), when only the expansion stroke injection operation is performed, and when both the expansion stroke injection operation and the exhaust throttle operation are performed, Experiments are performed in advance by changing the load conditions of the engine (fuel injection amount QIJ, rotation speed NE) to determine the optimal intake air amount (target intake air amount), and FIG. 2 using QIJ and NE in each case. Is stored in the ROM of the ECU 30 as a numerical map of the form:
Then, the target intake air amount is calculated based on the engine load condition by using a corresponding numerical map according to the presence or absence of the expansion stroke injection operation and the presence or absence of the exhaust throttle operation during engine operation.

【００５８】更に、本実施形態では実際の機関吸入空気
量が上記により算出した目標吸入空気量になるように吸
気絞り弁２７開度とＥＧＲ弁２３との開度を調節するこ
とにより、実際の機関吸入空気量が上記により算出した
目標吸入空気量に一致するように吸入空気量の制御を行
う。このように、膨張行程噴射操作実施の有無と排気絞
り操作実施の有無に応じて機関吸入空気量を最適な目標
吸入空気量に制御することにより、再生操作実施時に排
気温度を短時間で正確に目標温度に上昇させながら、同
時に吸入空気量の過不足による排気性状の悪化を防止す
ることが可能となる。Further, in this embodiment, the opening degree of the intake throttle valve 27 and the opening degree of the EGR valve 23 are adjusted so that the actual engine intake air amount becomes the target intake air amount calculated as described above. The intake air amount is controlled so that the engine intake air amount matches the target intake air amount calculated above. In this way, by controlling the engine intake air amount to the optimal target intake air amount in accordance with the presence or absence of the expansion stroke injection operation and the presence or absence of the exhaust throttle operation, the exhaust temperature can be accurately and quickly reduced during the regeneration operation. While the temperature is raised to the target temperature, it is possible to prevent deterioration of the exhaust properties due to excess or deficiency of the intake air amount.

【００５９】図６は、本実施形態の上述した吸入空気量
制御操作を具体的に説明するフローチャートである。本
操作はＥＣＵ３０により一定時間毎に実行されるルーチ
ンにより行われる。図６の操作において、ステップ６０
１では機関負荷条件（燃料噴射量ＱＩＪ、回転数ＮＥ）
が読み込まれ、ステップ６０３では現在膨張行程噴射操
作が実行されているか否か、すなわち現在ＤＰＦ４０の
再生操作が実行されているか否かが判定される。FIG. 6 is a flowchart specifically illustrating the above-described intake air amount control operation of the present embodiment. This operation is performed by a routine executed by the ECU 30 at regular intervals. In the operation of FIG.
At 1, engine load conditions (fuel injection amount QIJ, rotation speed NE)
Is read, and in step 603, it is determined whether or not the expansion stroke injection operation is currently being performed, that is, whether or not the regeneration operation of the DPF 40 is currently being performed.

【００６０】現在膨張行程噴射実行中でない場合、すな
わち現在通常運転中である場合には、次にステップ６０
７に進み、予めＥＣＵ３０のＲＯＭに格納した数値マッ
プのうち通常運転時用のマップを用いてステップ６０１
で読み込んだＱＩＪとＮＥとの値から目標吸入空気量が
設定される。そして、ステップ６０９では、吸気絞り弁
２７とＥＧＲ弁２３との開度が設定された目標吸入空気
量に応じて調節される。If the expansion stroke injection is not currently being executed, that is, if the normal operation is currently being performed, then step 60 is executed.
7, the program proceeds to step 601 using the map for normal operation among the numerical maps stored in the ROM of the ECU 30 in advance.
The target intake air amount is set from the values of QIJ and NE read in step (1). Then, in step 609, the opening degree of the intake throttle valve 27 and the EGR valve 23 is adjusted according to the set target intake air amount.

【００６１】また、ステップ６０３で現在膨張行程噴射
操作実施中である場合には、次にステップ６０５で現在
膨張行程噴射とともに排気絞り操作を実施中であるか否
かが判断され、膨張行程噴射操作のみ実施中の場合には
ステップ６１１で、ＥＣＵ３０のＲＯＭに格納した膨張
行程噴射実施時の数値マップに基づいて目標吸入空気量
が設定され、ステップ６１３では目標吸入空気量に応じ
て吸気絞り弁２７とＥＧＲ制御弁２３との開度が調節さ
れる。If it is determined in step 603 that the expansion stroke injection operation is currently being performed, it is determined in step 605 whether the exhaust throttle operation is currently being performed together with the expansion stroke injection. If only the operation is being performed, in step 611, the target intake air amount is set based on the numerical map during the execution of the expansion stroke injection stored in the ROM of the ECU 30. In step 613, the intake throttle valve 27 is set in accordance with the target intake air amount. And the opening degree of the EGR control valve 23 is adjusted.

【００６２】一方、ステップ６０５で膨張行程噴射操作
と排気絞り操作との両方が実施されている場合には、ス
テップ６１５でＥＣＵ３０のＲＯＭに格納した数値マッ
プのうち膨張行程噴射操作と排気絞り操作との両方を実
施した場合の数値マップに基づいて目標吸入空気量が設
定され、ステップ６１７では目標吸入空気量に応じて吸
気絞り弁２７とＥＧＲ制御弁２３との開度が調節され
る。On the other hand, if both the expansion stroke injection operation and the exhaust throttle operation are performed in step 605, the expansion stroke injection operation and the exhaust throttle operation of the numerical map stored in the ROM of the ECU 30 are performed in step 615. The target intake air amount is set based on the numerical map in the case of performing both of them, and in step 617, the opening degree of the intake throttle valve 27 and the EGR control valve 23 is adjusted according to the target intake air amount.

【００６３】本実施形態では、各操作条件（通常運転、
膨張行程噴射操作実施時、膨張行程噴射操作と排気絞り
操作との両方実施時）において、各機関負荷条件で機関
吸入空気量を目標吸入空気量にするために必要な吸気絞
り弁２７開度とＥＧＲ弁２３開度との組合せが予め実験
により求められ、それぞれの操作条件毎にＱＩＪとＮＥ
とを用いた図２の形式の数値マップの形でＥＣＵ３０の
ＲＯＭに格納されている。ステップ６０９、６１３、６
１７ではこれらの数値マップのうち、それぞれ該当する
操作条件のマップを用いてステップ６０１で読み込んだ
ＱＩＪとＮＥとの値に基づいて吸気絞り弁２７開度とＥ
ＧＲ弁２３開度とが設定される。In the present embodiment, each operating condition (normal operation,
(When the expansion stroke injection operation is performed, and when both the expansion stroke injection operation and the exhaust throttle operation are performed), the opening degree of the intake throttle valve 27 required to bring the engine intake air amount to the target intake air amount under each engine load condition. The combination with the opening degree of the EGR valve 23 is obtained in advance by an experiment, and QIJ and NE are determined for each operating condition.
Are stored in the ROM of the ECU 30 in the form of a numerical map in the form of FIG. Steps 609, 613, 6
In step 17, the intake throttle valve 27 opening degree and E based on the values of QIJ and NE read in step 601 using the maps of the corresponding operating conditions among these numerical maps.
The GR valve 23 opening is set.

【００６４】図６の操作を実行することにより、膨張行
程噴射操作実施の有無に応じて、また、膨張行程噴射操
作実施時には更に排気絞り操作実施の有無に応じて吸入
空気量が最適な目標吸入空気量に設定されるようにな
る。By executing the operation of FIG. 6, the optimum target intake air amount is determined according to whether or not the expansion stroke injection operation is performed, and according to whether or not the exhaust throttle operation is performed when the expansion stroke injection operation is performed. It will be set to the amount of air.

【００６５】[0065]

【発明の効果】各請求項に記載の発明によれば、パティ
キュレートフィルタ再生操作実施に機関排気温度を短時
間で精度良く目標温度に制御することにより、短時間で
パティキュレートフィルタ再生処理を完了することが可
能となる共通の効果を奏する。According to the present invention, the particulate filter regeneration process is completed in a short time by precisely controlling the engine exhaust temperature to the target temperature in a short time when performing the particulate filter regeneration operation. This has a common effect that can be performed.

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

【図１】本発明のパティキュレートフィルタ再生処理制
御装置を自動車用ディーゼル機関に適用した場合の概略
構成を示す図である。FIG. 1 is a diagram showing a schematic configuration when a particulate filter regeneration processing control device of the present invention is applied to an automobile diesel engine.

【図２】数値マップの形式の一例を示す図である。FIG. 2 is a diagram showing an example of a format of a numerical map.

【図３】パティキュレートフィルタ再生処理における各
操作量の決定操作を説明するフローチャートである。FIG. 3 is a flowchart illustrating an operation of determining each operation amount in a particulate filter regeneration process.

【図４】パティキュレートフィルタ再生処理におけるＥ
ＧＲガス量の増量補正操作を説明するフローチャートで
ある。FIG. 4 shows E in a particulate filter regeneration process.
It is a flowchart explaining the increase correction operation of GR gas amount.

【図５】パティキュレートフィルタ再生処理におけるＥ
ＧＲガス量の設定操作を説明するフローチャートであ
る。FIG. 5 shows E in a particulate filter regeneration process.
It is a flowchart explaining the setting operation of the GR gas amount.

【図６】パティキュレートフィルタ再生処理における機
関吸入空気量の制御操作を説明するフローチャートであ
る。FIG. 6 is a flowchart illustrating a control operation of an engine intake air amount in a particulate filter regeneration process.

【符号の説明】[Explanation of symbols]

１…ディーゼル機関 １１１…筒内燃料噴射弁 ２７…吸気絞り弁 ３０…電子制御ユニット（ＥＣＵ） ３…排気通路 ３１…排気マニホルド ３７…排気絞り弁 ３３…ＥＧＲ通路 ２３…ＥＧＲ弁 ４０…パティキュレートフィルタ（ＤＰＦ） ５３…排気温度センサ ５９…冷却水温度センサ DESCRIPTION OF SYMBOLS 1 ... Diesel engine 111 ... In-cylinder fuel injection valve 27 ... Intake throttle valve 30 ... Electronic control unit (ECU) 3 ... Exhaust passage 31 ... Exhaust manifold 37 ... Exhaust throttle valve 33 ... EGR passage 23 ... EGR valve 40 ... Particulate filter (DPF) 53 ... Exhaust temperature sensor 59 ... Cooling water temperature sensor

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｆ０２Ｄ 21/08 ３０１ Ｆ０２Ｄ 21/08 ３０１Ｂ 41/04 ３６０ 41/04 ３６０Ｚ 41/40 41/40 Ｃ 43/00 ３０１ 43/00 ３０１Ｈ ３０１Ｊ ３０１Ｎ ３０１Ｔ ３０１Ｚ ３０１Ｋ Ｆ０２Ｍ 25/07 ５５０ Ｆ０２Ｍ 25/07 ５５０Ａ ５５０Ｃ ５７０ ５７０Ｄ ５７０Ｊ Ｆターム(参考） 3G062 AA01 AA05 BA05 BA06 CA06 EA05 EA11 GA01 GA04 GA06 GA09 GA15 GA21 3G084 AA01 BA00 BA05 BA13 BA15 BA20 BA24 DA05 EB08 FA07 FA10 FA33 3G090 AA02 BA01 CA00 CB25 DA00 DA12 DA18 EA04 EA06 3G092 AA02 AA17 BB01 BB06 DC03 DC09 DC10 DC12 DC14 DG06 DG08 EA01 EA13 EA14 EA17 FA18 HA01Z HA06X HA06Z HB01X HB01Z HB02X HB02Z HD01X HD01Z HD09X HD09Z HE01Z HF08Z 3G301 HA02 HA06 HA13 JA24 LA00 LB13 MA11 MA18 PA01Z PD11Z PE01Z PF03Z ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification code FI Theme coat ゛ (Reference) F02D 21/08 301 F02D 21/08 301B 41/04 360 41/04 360Z 41/40 41/40 C 43 / 00 301 43/00 301H 301J 301N 301T 301Z 301K F02M 25/07 550 F02M 25/07 550A 550C 570 570D 570J F-term (reference) 3G062 AA01 AA05 BA05 BA06 CA06 EA05 EA11 BA01 GA05 GA01 BA10 BA20 BA24 DA05 EB08 FA07 FA10 FA33 3G090 AA02 BA01 CA00 CB25 DA00 DA12 DA18 EA04 EA06 3G092 AA02 AA17 BB01 BB06 DC03 DC09 DC10 DC12 DC14 DG06 DG08 EA01 EA13 EA14 EA17 FA18 HA01Z HA06X HA06BZHBZH01B01 HA13 JA24 LA00 LB13 MA11 MA18 P A01Z PD11Z PE01Z PF03Z

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 内燃機関の排気中のパティキュレートを
捕集するパティキュレートフィルタの再生処理を機関運
転状態に応じて制御する再生処理制御装置であって、 内燃機関の排気通路に配置した排気絞り弁を作動させて
排気流量を低減する排気絞り操作と、各気筒の膨張行程
中に燃料噴射を行なう膨張行程噴射操作と、機関排気系
から吸気系に排気の一部を再循環させるするＥＧＲ操作
と、各気筒の主燃料噴射量と噴射時期とを変更する主燃
料噴射制御操作のいずれか１つ、または２つ以上の組合
せにより機関排気温度を上昇させてパティキュレートフ
ィルタ内に捕集されたパティキュレートを燃焼させるパ
ティキュレートフィルタ再生処理を行うとともに、 前記排気絞り操作を実施する場合には、前記膨張行程燃
料噴射量及び噴射時期、再循環排気流量、主燃料噴射量
及び噴射時期、の各操作量を予め定めた第１の関係に基
づいて機関運転状態に応じて決定し、 排気絞り操作を実施しない場合には、前記各操作量を前
記第１の関係とは異なる予め定めた第２の関係に基づい
て機関運転状態に応じて決定するパティキュレートフィ
ルタの再生処理制御装置。1. A regeneration control device for controlling a regeneration process of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine according to an engine operating state, comprising: an exhaust throttle disposed in an exhaust passage of the internal combustion engine. Exhaust throttle operation to reduce exhaust flow rate by operating a valve, expansion stroke injection operation to inject fuel during the expansion stroke of each cylinder, and EGR operation to recirculate part of exhaust gas from the engine exhaust system to the intake system And the engine exhaust temperature is increased by one or a combination of two or more main fuel injection control operations for changing the main fuel injection amount and the injection timing of each cylinder, and the fuel is collected in the particulate filter. Along with performing a particulate filter regeneration process for burning particulates, when performing the exhaust throttle operation, the expansion stroke fuel injection amount and injection timing, The respective operation amounts of the circulating exhaust flow rate, the main fuel injection amount, and the injection timing are determined according to the engine operating state based on a predetermined first relationship, and when the exhaust throttle operation is not performed, the respective operation amounts are determined. Is determined in accordance with the engine operating state based on a predetermined second relationship different from the first relationship. 【請求項２】 内燃機関の排気中のパティキュレートを
捕集するパティキュレートフィルタの再生処理を機関運
転状態に応じて制御する再生処理制御装置であって、 内燃機関の各気筒の膨張行程中に燃料噴射を行なう膨張
行程噴射操作により機関排気温度を上昇させてパティキ
ュレートフィルタ内に捕集されたパティキュレートを燃
焼させるパティキュレートフィルタ再生処理を行うとと
もに、膨張行程噴射操作実施中に、機関排気系から吸気
系に排気の一部を再循環させるＥＧＲ操作を実施する場
合には、膨張行程噴射操作を実施しない場合に較べて前
記ＥＧＲ操作における再循環排気流量を増大させるパテ
ィキュレートフィルタの再生処理制御装置。2. A regeneration control device for controlling regeneration of a particulate filter for trapping particulates in exhaust gas of an internal combustion engine according to an engine operating state, wherein the regeneration process is performed during an expansion stroke of each cylinder of the internal combustion engine. In addition to performing a particulate filter regeneration process of raising the engine exhaust temperature by an expansion stroke injection operation for performing fuel injection and burning the particulates collected in the particulate filter, the engine exhaust system is operated during the expansion stroke injection operation. When the EGR operation for recirculating a part of the exhaust gas to the intake system is performed, the regeneration control of the particulate filter for increasing the recirculated exhaust flow rate in the EGR operation is performed as compared with the case where the expansion stroke injection operation is not performed. apparatus. 【請求項３】 内燃機関の排気中のパティキュレートを
捕集するパティキュレートフィルタの再生処理を機関運
転状態に応じて制御する再生処理制御装置であって、 内燃機関の排気通路に配置した排気絞り弁を作動させて
排気流量を低減する排気絞り操作と、各気筒の膨張行程
中に燃料噴射を行なう膨張行程噴射操作の一方または両
方を実施することにより機関排気温度を上昇させてパテ
ィキュレートフィルタ内に捕集されたパティキュレート
を燃焼させるパティキュレートフィルタ再生処理を行う
とともに、前記膨張行程噴射操作と前記排気絞り操作と
の両方を同時に実施する場合には、機関排気系から吸気
系に排気の一部を再循環させるＥＧＲ操作を停止するパ
ティキュレートフィルタの再生処理制御装置。3. A regeneration control device for controlling regeneration of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine according to an engine operating state, comprising: an exhaust throttle disposed in an exhaust passage of the internal combustion engine. The exhaust gas temperature is increased by operating one or both of an exhaust throttle operation for reducing the exhaust flow rate by operating a valve and an expansion stroke injection operation for injecting fuel during an expansion stroke of each cylinder to increase the engine exhaust temperature and thereby reduce the amount of exhaust gas in the particulate filter. When performing the particulate filter regeneration process for burning the particulates collected in the engine and simultaneously performing both the expansion stroke injection operation and the exhaust throttle operation, the exhaust gas is discharged from the engine exhaust system to the intake system. A regeneration control device for a particulate filter for stopping an EGR operation for recirculating the part. 【請求項４】 内燃機関の排気中のパティキュレートを
捕集するパティキュレートフィルタの再生処理を機関運
転状態に応じて制御する再生処理制御装置であって、 内燃機関の排気通路に配置した排気絞り弁を作動させて
排気流量を低減する排気絞り操作と、各気筒の膨張行程
中に燃料噴射を行なう膨張行程噴射操作の一方または両
方を実施することにより機関排気温度を上昇させてパテ
ィキュレートフィルタ内に捕集されたパティキュレート
を燃焼させるパティキュレートフィルタ再生処理を行う
とともに、前記膨張行程噴射操作実施の有無、及び前記
膨張行程噴射操作実施時には更に前記排気絞り操作実施
の有無、に応じて機関目標吸入空気量を機関運転状態に
基づいてそれぞれ異なる値に設定し、 機関吸気通路に配置された吸気絞り弁の開度と機関排気
系から機関吸気系に再循環させる排気の量を制御するＥ
ＧＲ弁の開度との一方または両方を制御することにより
機関吸入空気量を前記目標吸入空気量に制御するパティ
キュレートフィルタの再生処理制御装置。4. A regeneration control device for controlling regeneration of a particulate filter for collecting particulates in exhaust gas of an internal combustion engine according to an engine operating state, comprising: an exhaust throttle disposed in an exhaust passage of the internal combustion engine. The exhaust gas temperature is increased by operating one or both of an exhaust throttle operation for reducing the exhaust flow rate by operating a valve and an expansion stroke injection operation for injecting fuel during an expansion stroke of each cylinder to increase the engine exhaust temperature and thereby reduce the amount of exhaust gas in the particulate filter. A particulate filter regeneration process for burning the particulates collected in the engine is performed, and the engine target is determined according to whether or not the expansion stroke injection operation is performed and whether or not the exhaust throttle operation is further performed when the expansion stroke injection operation is performed. The intake air flow rate is set to different values based on the engine operating condition, and the intake throttle valve located in the engine intake passage E for controlling the amount of exhaust gas recirculated to the engine intake system from the opening and the exhaust system
A particulate filter regeneration control device for controlling one or both of the degree of opening of a GR valve to control the engine intake air amount to the target intake air amount.
JP35317798A 1998-12-01 1998-12-11 Regeneration processing control device for particulate filter Expired - Fee Related JP3454351B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP35317798A JP3454351B2 (en) 1998-12-11 1998-12-11 Regeneration processing control device for particulate filter
DE19957715A DE19957715C2 (en) 1998-12-01 1999-11-30 Exhaust emission control device for an internal combustion engine
FR9915162A FR2786529B1 (en) 1998-12-01 1999-12-01 EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP35317798A JP3454351B2 (en) 1998-12-11 1998-12-11 Regeneration processing control device for particulate filter

Publications (2)

Publication Number Publication Date
JP2000179326A true JP2000179326A (en) 2000-06-27
JP3454351B2 JP3454351B2 (en) 2003-10-06

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Country Link
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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1375877A2 (en) 2002-06-28 2004-01-02 Nissan Motor Co., Ltd. Regeneration of particulate filter
EP1380742A1 (en) * 2002-07-09 2004-01-14 Mazda Motor Corporation Fuel injection control device, method and computer program for engine
EP1662123A2 (en) 2004-11-26 2006-05-31 Toyota Jidosha Kabushiki Kaisha Catalyst temperature raise-up system of internal combustion engine
US7062907B2 (en) 2003-07-30 2006-06-20 Nissan Motor Co., Ltd. Regeneration control system
FR2881180A1 (en) * 2005-01-26 2006-07-28 Renault Sas Internal combustion engine e.g. diesel engine, control method for vehicle, involves recycling burnt gas collected by burnt gas recycling circuit towards chamber so that temperature is raised above predetermined temperature threshold
US7107760B2 (en) 2003-04-18 2006-09-19 Nissan Motor Co., Ltd. Exhaust gas purifying system for internal combustion engine
US7117843B2 (en) * 2004-10-07 2006-10-10 International Engine Intellectual Property Company, Llc Emission reduction in a diesel engine using an alternative combustion process and a low-pressure EGR loop
US7137247B2 (en) 2003-01-10 2006-11-21 Nissan Motor Co., Ltd. Regeneration apparatus and method for particulate filter applicable to engine exhaust gas purifying device
JP2007298047A (en) * 2007-08-22 2007-11-15 Hitachi Ltd Variable valve gear for internal combustion engine and controller of variable valve gear for internal combustion engine
JP2008215076A (en) * 2007-02-28 2008-09-18 Iseki & Co Ltd Engine
JP2013024225A (en) * 2011-07-26 2013-02-04 Mitsubishi Motors Corp Exhaust temperature control device
JP2013122211A (en) * 2011-12-12 2013-06-20 Isuzu Motors Ltd Exhaust gas purification method and system for diesel engine
US11293320B2 (en) 2018-09-10 2022-04-05 Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. Control device, exhaust gas purification system, and control method of engine
US11441472B2 (en) 2018-08-08 2022-09-13 Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. Control device, exhaust gas purification system, and control method

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6851258B2 (en) 2002-06-28 2005-02-08 Nissan Motor Co., Ltd. Regeneration of particulate filter
EP1375877A2 (en) 2002-06-28 2004-01-02 Nissan Motor Co., Ltd. Regeneration of particulate filter
EP1380742A1 (en) * 2002-07-09 2004-01-14 Mazda Motor Corporation Fuel injection control device, method and computer program for engine
US7137247B2 (en) 2003-01-10 2006-11-21 Nissan Motor Co., Ltd. Regeneration apparatus and method for particulate filter applicable to engine exhaust gas purifying device
US7107760B2 (en) 2003-04-18 2006-09-19 Nissan Motor Co., Ltd. Exhaust gas purifying system for internal combustion engine
US7062907B2 (en) 2003-07-30 2006-06-20 Nissan Motor Co., Ltd. Regeneration control system
US7117843B2 (en) * 2004-10-07 2006-10-10 International Engine Intellectual Property Company, Llc Emission reduction in a diesel engine using an alternative combustion process and a low-pressure EGR loop
EP1662123A2 (en) 2004-11-26 2006-05-31 Toyota Jidosha Kabushiki Kaisha Catalyst temperature raise-up system of internal combustion engine
FR2881180A1 (en) * 2005-01-26 2006-07-28 Renault Sas Internal combustion engine e.g. diesel engine, control method for vehicle, involves recycling burnt gas collected by burnt gas recycling circuit towards chamber so that temperature is raised above predetermined temperature threshold
JP2008215076A (en) * 2007-02-28 2008-09-18 Iseki & Co Ltd Engine
JP2007298047A (en) * 2007-08-22 2007-11-15 Hitachi Ltd Variable valve gear for internal combustion engine and controller of variable valve gear for internal combustion engine
JP4571172B2 (en) * 2007-08-22 2010-10-27 日立オートモティブシステムズ株式会社 Variable valve operating apparatus for internal combustion engine and controller for variable valve operating apparatus for internal combustion engine
JP2013024225A (en) * 2011-07-26 2013-02-04 Mitsubishi Motors Corp Exhaust temperature control device
JP2013122211A (en) * 2011-12-12 2013-06-20 Isuzu Motors Ltd Exhaust gas purification method and system for diesel engine
WO2013088888A1 (en) * 2011-12-12 2013-06-20 いすゞ自動車株式会社 Diesel engine exhaust gas purification method and exhaust gas purification system
US11441472B2 (en) 2018-08-08 2022-09-13 Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. Control device, exhaust gas purification system, and control method
US11293320B2 (en) 2018-09-10 2022-04-05 Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. Control device, exhaust gas purification system, and control method of engine

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