JP2003247459A - Egr mechanism for internal combustion engine - Google Patents
Egr mechanism for internal combustion engineInfo
- Publication number
- JP2003247459A JP2003247459A JP2002043575A JP2002043575A JP2003247459A JP 2003247459 A JP2003247459 A JP 2003247459A JP 2002043575 A JP2002043575 A JP 2002043575A JP 2002043575 A JP2002043575 A JP 2002043575A JP 2003247459 A JP2003247459 A JP 2003247459A
- Authority
- JP
- Japan
- Prior art keywords
- intake air
- air amount
- egr
- internal combustion
- combustion engine
- 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
Links
Classifications
-
- 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
- F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- F02M26/22—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
- F02M26/23—Layout, e.g. schematics
- F02M26/25—Layout, e.g. schematics with coolers having bypasses
-
- 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
- F02M26/49—Detecting, diagnosing or indicating an abnormal function of the EGR system
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
- Processes For Solid Components From Exhaust (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Exhaust-Gas Circulating Devices (AREA)
- Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、内燃機関のＥＧＲ
機構に関し、特に、ＥＧＲ通路を流れるＥＧＲガスを冷
却するＥＧＲクーラと、ＥＧＲクーラを迂回するバイパ
ス通路と、ＥＧＲクーラとバイパス通路とへ流入するＥ
ＧＲガスの流量比を制御するバイパス制御弁とを備えた
内燃機関のＥＧＲ機構に関する。TECHNICAL FIELD The present invention relates to an EGR of an internal combustion engine.
Regarding the mechanism, in particular, an EGR cooler that cools the EGR gas flowing through the EGR passage, a bypass passage that bypasses the EGR cooler, and an E that flows into the EGR cooler and the bypass passage
The present invention relates to an EGR mechanism of an internal combustion engine that includes a bypass control valve that controls a flow rate ratio of GR gas.
【０００２】[0002]
【従来の技術】従来、内燃機関から排出されるＮＯx量
を減少させる技術として、内燃機関の排気系から吸気系
へ排気の一部を還流させて混合気の燃焼温度を低下させ
るＥＧＲ（Exhaust Gas Recirculation）機構が提案さ
れている。このようなＥＧＲ機構としては、内燃機関の
排気系と吸気系とを連通させるＥＧＲ通路の途中にＥＧ
Ｒガスを冷却するＥＧＲクーラが設けられたＥＧＲ機構
が知られている。2. Description of the Related Art Conventionally, as a technique for reducing the amount of NOx emitted from an internal combustion engine, an EGR (Exhaust Gas) is used to reduce the combustion temperature of an air-fuel mixture by recirculating a part of exhaust gas from an exhaust system of the internal combustion engine to an intake system. Recirculation) mechanism has been proposed. As such an EGR mechanism, an EG is provided in the middle of an EGR passage that connects an exhaust system and an intake system of an internal combustion engine.
An EGR mechanism provided with an EGR cooler that cools R gas is known.
【０００３】ＥＧＲクーラを備えたＥＧＲ機構は、混合
気中に混入されるＥＧＲガスの温度を低くすることがで
きるとともにＥＧＲガスの体積を縮小させることができ
るため、内燃機関に吸入される新気の量を過剰に減少さ
せることなく燃焼温度を低下させることが可能となる。The EGR mechanism provided with the EGR cooler can lower the temperature of the EGR gas mixed in the air-fuel mixture and can reduce the volume of the EGR gas. It becomes possible to lower the combustion temperature without excessively reducing the amount of.
【０００４】しかしながら、ＥＧＲガスが常にＥＧＲク
ーラを経由すると、内燃機関が低回転・低負荷運転され
ている時のように排気温度が低く且つ排気の流量が少な
い時に、ＥＧＲガスがＥＧＲクーラにおいて過冷却され
るため、混合気の温度が過剰に低下して不完全燃焼や失
火を招くとともに、ＥＧＲクーラに付着するデポジット
が増加してＥＧＲクーラの目詰まりを誘発する虞があ
る。However, if the EGR gas always passes through the EGR cooler, when the internal combustion engine is operating at a low speed and a low load and the exhaust temperature is low and the flow rate of the exhaust gas is low, the EGR gas is excessive in the EGR cooler. Since the air-fuel mixture is cooled, the temperature of the air-fuel mixture is excessively lowered to cause incomplete combustion or misfire, and the deposit adhering to the EGR cooler increases, possibly causing clogging of the EGR cooler.
【０００５】これに対し、特開２００１−２８０１２３
号公報等に記載されているように、排気還流通路に設け
られたＥＧＲクーラと、このＥＧＲクーラを迂回するバ
イパス通路と、ＥＧＲクーラを流通するＥＧＲガス量と
バイパス通路を流通するＥＧＲガス量との比率を制御す
るバイパス制御弁とを備え、ＥＧＲクーラを流通するＥ
ＧＲガス量とバイパス通路を流通するＥＧＲガス量とを
調節することにより、ＥＧＲクーラによるＥＧＲガスの
過冷却を防止しようとするＥＧＲ機構が提案されてい
る。On the other hand, Japanese Patent Laid-Open No. 2001-280123
As described in Japanese Unexamined Patent Publication (KOKAI) Publication No. 2003-242977, an EGR cooler provided in an exhaust gas recirculation passage, a bypass passage bypassing the EGR cooler, an EGR gas amount flowing in the EGR cooler, and an EGR gas amount flowing in the bypass passage And a bypass control valve for controlling the ratio of E
An EGR mechanism has been proposed which attempts to prevent overcooling of EGR gas by an EGR cooler by adjusting the amount of GR gas and the amount of EGR gas flowing through the bypass passage.
【０００６】[0006]
【発明が解決しようとする課題】ところで、前述した従
来の技術では、バイパス制御弁が特定の開度で固着する
と、ＥＧＲクーラを流通するＥＧＲガス量とバイパス通
路を流通するＥＧＲガス量とを調節することが不可能と
なるため、内燃機関に流入するＥＧＲガスの温度や量を
所望の温度や量とすることができず、内燃機関の燃焼状
態の悪化やＥＧＲクーラの目詰まりなどが誘発される虞
がある。By the way, in the above-mentioned conventional technique, when the bypass control valve is fixed at a specific opening, the EGR gas amount flowing through the EGR cooler and the EGR gas amount flowing through the bypass passage are adjusted. Therefore, the temperature and amount of the EGR gas flowing into the internal combustion engine cannot be set to the desired temperature and amount, and the combustion state of the internal combustion engine is deteriorated and the EGR cooler is clogged. May occur.
【０００７】本発明は上記したような問題点に鑑みてな
されたものであり、ＥＧＲ通路を流れるＥＧＲガスを冷
却するＥＧＲクーラと、ＥＧＲクーラを迂回するバイパ
ス通路と、ＥＧＲクーラとバイパス通路とへ流入するＥ
ＧＲガスの流量比を調整するバイパス制御弁とを備えた
内燃機関のＥＧＲ機構において、バイパス制御弁の固着
を検出可能な技術を提供することを目的とする。The present invention has been made in view of the above problems, and provides an EGR cooler for cooling the EGR gas flowing through the EGR passage, a bypass passage bypassing the EGR cooler, an EGR cooler and a bypass passage. Inflowing E
An object of the present invention is to provide a technique capable of detecting sticking of a bypass control valve in an EGR mechanism of an internal combustion engine provided with a bypass control valve that adjusts a flow rate ratio of GR gas.
【０００８】[0008]
【課題を解決するための手段】本発明は、上記課題を解
決するために以下のような手段を採用した。すなわち、
本発明に係る内燃機関のＥＧＲ機構は、内燃機関の排気
系から吸気系へ排気の一部を還流させるＥＧＲ通路と、
前記ＥＧＲ通路を流れるＥＧＲガス量を調節するＥＧＲ
弁と、前記ＥＧＲ通路に設けられ、該ＥＧＲ通路を流れ
るＥＧＲガスを冷却するＥＧＲクーラと、前記ＥＧＲ通
路において前記ＥＧＲクーラを迂回するバイパス通路
と、前記ＥＧＲクーラと前記バイパス通路とへ流入する
ＥＧＲガスの流量比を調整するバイパス制御弁と、前記
内燃機関の吸気系に設けられ、該吸気系を流れる空気量
を調整する吸気絞り弁と、前記内燃機関の吸入空気量を
検出する吸入空気量検出手段と、前記ＥＧＲ弁が全開で
あり且つ前記吸気絞り弁が全開であることを条件に前記
バイパス通路を全開及び全閉するよう前記バイパス制御
弁を制御し、全開制御時及び全閉制御時に前記吸入空気
量検出手段が検出した吸入空気量をパラメータとしてバ
イパス制御弁の固着を検出する固着検出手段と、を備え
ることを特徴とする。The present invention employs the following means in order to solve the above problems. That is,
An EGR mechanism of an internal combustion engine according to the present invention includes an EGR passage that recirculates a part of exhaust gas from an exhaust system of the internal combustion engine to an intake system,
EGR for adjusting the amount of EGR gas flowing through the EGR passage
A valve, an EGR cooler provided in the EGR passage for cooling the EGR gas flowing in the EGR passage, a bypass passage bypassing the EGR cooler in the EGR passage, and an EGR flowing into the EGR cooler and the bypass passage. A bypass control valve for adjusting the gas flow rate ratio, an intake throttle valve provided in the intake system of the internal combustion engine for adjusting the amount of air flowing through the intake system, and an intake air amount for detecting the intake air amount of the internal combustion engine. The bypass control valve is controlled to fully open and fully close the bypass passage on condition that the detecting means and the EGR valve are fully open and the intake throttle valve is fully open. And a sticking detection means for detecting sticking of the bypass control valve using the intake air quantity detected by the intake air quantity detecting means as a parameter.
【０００９】この発明は、内燃機関の吸気系を流れる空
気量を調節する吸気絞り弁と、ＥＧＲ通路を流れるＥＧ
Ｒガス量を調節するＥＧＲ弁と、ＥＧＲ通路を流れるＥ
ＧＲガスを冷却するＥＧＲクーラと、ＥＧＲクーラを迂
回するバイパス通路と、ＥＧＲクーラとバイパス通路と
へ流入するＥＧＲガスの流量比を調整するバイパス制御
弁とを備えた内燃機関のＥＧＲ機構において、吸気絞り
弁及びＥＧＲ弁が全開であるときにバイパス通路を全開
及び全閉させるようバイパス制御弁を制御し、全開制御
時の吸入空気量と全閉制御時の吸入空気量とをパラメー
タとしてバイパス制御弁の固着を検出することを最大の
特徴としている。According to the present invention, the intake throttle valve for adjusting the amount of air flowing through the intake system of the internal combustion engine and the EG flowing through the EGR passage are provided.
An EGR valve that adjusts the amount of R gas and an E that flows through the EGR passage
In an EGR mechanism of an internal combustion engine including an EGR cooler that cools GR gas, a bypass passage that bypasses the EGR cooler, and a bypass control valve that adjusts a flow rate ratio of EGR gas flowing into the EGR cooler and the bypass passage, The bypass control valve is controlled so that the bypass passage is fully opened and fully closed when the throttle valve and the EGR valve are fully open, and the intake air amount at the fully open control and the intake air amount at the fully closed control are used as parameters. The greatest feature is the detection of sticking.
【００１０】かかる内燃機関のＥＧＲ機構では、固着検
出手段は、ＥＧＲ弁及び吸気絞り弁が全開であるとき
に、バイパス制御弁を全開及び全閉に制御し、全開制御
時に吸入空気量検出手段が検出した吸入空気量と全閉制
御時に吸入空気量検出手段が検出した吸入空気量とをパ
ラメータとしてバイパス制御弁の固着を検出する。In such an EGR mechanism of an internal combustion engine, the sticking detection means controls the bypass control valve to be fully opened and fully closed when the EGR valve and the intake throttle valve are fully opened, and the intake air amount detection means is provided at the fully opened control time. The sticking of the bypass control valve is detected by using the detected intake air amount and the intake air amount detected by the intake air amount detecting means during the fully closed control as parameters.
【００１１】ここで、内燃機関の吸入空気量は、ＥＧＲ
ガスの還流量が多くなるほど少なくなり、逆にＥＧＲガ
ス量の還流量が少なくなるほど多くなる。更に、バイパ
ス通路とＥＧＲクーラとでは排気抵抗が異なるため、言
い換えればバイパス通路とＥＧＲクーラとでは排気の圧
力損失が異なるため、バイパス制御弁が正常である場合
（バイパス制御弁が固着していない場合）は、バイパス
制御弁が全開制御された時に内燃機関に吸入されるＥＧ
Ｒガス量とバイパス制御弁が全閉制御された時に内燃機
関に吸入されるＥＧＲガス量とが異なる。Here, the intake air amount of the internal combustion engine is EGR
It decreases as the gas recirculation amount increases, and conversely increases as the EGR gas amount recirculation amount decreases. Further, because the exhaust resistance differs between the bypass passage and the EGR cooler, in other words, the pressure loss of the exhaust differs between the bypass passage and the EGR cooler, the bypass control valve is normal (when the bypass control valve is not stuck). ) Is the EG that is taken into the internal combustion engine when the bypass control valve is fully opened.
The R gas amount and the EGR gas amount sucked into the internal combustion engine when the bypass control valve is fully closed are different.
【００１２】従って、バイパス制御弁が正常である場合
は、バイパス制御弁が全開制御された時の吸入空気量と
バイパス制御弁が全閉制御された時の吸入空気量とは異
なる量となる。Therefore, when the bypass control valve is normal, the intake air amount when the bypass control valve is fully opened and the intake air amount when the bypass control valve is fully closed are different amounts.
【００１３】これに対し、バイパス制御弁が固着してい
る場合には、バイパス制御手段が全開制御された時と全
閉制御された時の双方においてバイパス制御弁の実際の
開度が同一となるため、全開制御時の吸入空気量と全閉
制御時の吸入空気量とが略同一の量となる。On the other hand, when the bypass control valve is stuck, the actual opening degree of the bypass control valve becomes the same both when the bypass control means is fully opened and when it is fully closed. Therefore, the intake air amount during the full open control and the intake air amount during the full close control are substantially the same.
【００１４】このように、吸気絞り弁及びＥＧＲ弁が全
開状態にある状況下でバイパス制御弁が全開制御された
時の吸入空気量と全閉制御された時の吸入空気量との相
対関係は、バイパス制御弁が正常である場合と固着して
いる場合とで異なる関係となる。As described above, the relative relationship between the intake air amount when the bypass control valve is fully opened and the intake air amount when fully closed is controlled under the condition that the intake throttle valve and the EGR valve are fully opened. The relationship between the case where the bypass control valve is normal and the case where the bypass control valve is stuck is different.
【００１５】この結果、吸気絞り弁及びＥＧＲ弁が全開
状態にある状況下でバイパス制御弁が全開制御された時
の吸入空気量と全閉制御された時の吸入空気量とをパラ
メータとすることにより、バイパス制御弁が固着してい
るか否かを判別することが可能となる。As a result, the intake air amount when the bypass control valve is fully opened and the intake air amount when fully closed are controlled with the intake throttle valve and the EGR valve being in the fully open state. This makes it possible to determine whether or not the bypass control valve is stuck.
【００１６】例えば、固着検出手段は、バイパス制御弁
が全開制御されている時の吸入空気量と全閉制御されて
いる時の吸入空気量とが異なっている場合にはバイパス
制御弁が固着していないと判定し、バイパス制御弁が全
開制御されている時の吸入空気量と全閉制御されている
時の吸入空気量とが略等しい場合にはバイパス制御弁が
固着していると判定することができる。For example, the sticking detection means may fix the bypass control valve when the intake air amount when the bypass control valve is fully opened is different from the intake air amount when the bypass control valve is fully closed. If the intake air amount when the bypass control valve is fully opened and the intake air amount when the bypass control valve is fully closed are substantially equal, it is determined that the bypass control valve is stuck. be able to.
【００１７】ここで、バイパス制御弁が固着する態様と
しては、全開位置で固着している態様と、全閉位置で固
着している態様と、中開位置で固着している態様とが考
えられる。Here, as the mode in which the bypass control valve is fixed, there are a mode in which it is fixed in the fully open position, a mode in which it is fixed in the fully closed position, and a mode in which it is fixed at the medium open position. .
【００１８】バイパス制御弁が全開位置で固着している
状況下では、全開制御時及び全閉制御時の双方において
バイパス制御弁の実際の開度が全開となるため、全開制
御時の吸入空気量と全閉制御時の吸入空気量とが略等し
くなり、全開制御時の吸入空気量が正常時の吸入空気量
と略等しくなり、更に全閉制御時の吸入空気量が正常時
の吸入空気量と異なる量となる。In a situation where the bypass control valve is stuck in the fully open position, the actual opening of the bypass control valve is fully opened both in the fully open control and the fully closed control. And the intake air amount during full-closed control are approximately equal, the intake air amount during full-open control is approximately equal to the normal intake air amount, and the intake air amount during full-closed control is normal intake air amount. And a different amount.
【００１９】その際、バイパス通路による排気の圧力損
失がＥＧＲクーラによる排気の圧力損失に比して大きく
なるようバイパス通路及びＥＧＲクーラが構成されてい
ると、バイパス制御弁が正常である状況下において全開
制御時のＥＧＲガス量が全閉制御時のＥＧＲガス量より
少なくなり、それに応じて全開制御時の吸入空気量が全
閉制御時の吸入空気量より多くなるため、バイパス制御
弁が全開位置で固着している状況下では全閉制御時の吸
入空気量が正常時の吸入空気量より多くなる。At this time, if the bypass passage and the EGR cooler are configured so that the pressure loss of the exhaust gas due to the bypass passage becomes larger than the pressure loss of the exhaust gas due to the EGR cooler, under the condition that the bypass control valve is normal. The EGR gas amount during full-open control is less than the EGR gas amount during full-close control, and the intake air amount during full-open control is correspondingly greater than the intake air amount during full-close control. In the situation where the valve is stuck at, the intake air amount during the fully closed control becomes larger than the normal intake air amount.
【００２０】従って、本発明に係る内燃機関のＥＧＲ機
構において、バイパス通路による排気の圧力損失がＥＧ
Ｒクーラによる排気の圧力損失に比して大きくなるよう
バイパス通路及びＥＧＲクーラが構成されている場合に
は、固着検出手段は、全開制御時の吸入空気量と全閉制
御時の吸入空気量とが略等しく、全開制御時の吸入空気
量が正常時の吸入空気量と略等しく、更に全閉制御時の
吸入空気量が正常時の吸入空気量より多いことを条件
に、バイパス制御弁が全開位置で固着していると判定す
ることができる。Therefore, in the EGR mechanism of the internal combustion engine according to the present invention, the exhaust gas pressure loss due to the bypass passage is EG
When the bypass passage and the EGR cooler are configured so as to be larger than the pressure loss of the exhaust gas due to the R cooler, the sticking detection means determines the intake air amount during the fully open control and the intake air amount during the fully closed control. Are approximately equal, the intake air amount during full open control is approximately equal to the normal intake air amount, and the intake air amount during full close control is greater than the normal intake air amount, the bypass control valve is fully open. It can be determined that the position is fixed.
【００２１】一方、バイパス通路による排気の圧力損失
がＥＧＲクーラによる排気の圧力損失に比して小さくな
るようバイパス通路及びＥＧＲクーラが構成されている
と、バイパス制御弁が正常である状況下において全開制
御時のＥＧＲガス量が全閉制御時のＥＧＲガス量より多
くなり、それに応じて全開制御時の吸入空気量が全閉制
御時の吸入空気量より少なくなるため、バイパス制御弁
が全開位置で固着している状況下では全閉制御時の吸入
空気量が正常時の吸入空気量より少なくなる。On the other hand, when the bypass passage and the EGR cooler are configured so that the pressure loss of the exhaust gas due to the bypass passage becomes smaller than the pressure loss of the exhaust gas due to the EGR cooler, the bypass control valve is fully opened under normal conditions. Since the EGR gas amount during control becomes larger than the EGR gas amount during fully closed control and the intake air amount during fully open control becomes smaller than the intake air amount during fully closed control accordingly, the bypass control valve is at the fully open position. In the case of sticking, the intake air amount in the fully closed control becomes smaller than the normal intake air amount.
【００２２】従って、本発明に係る内燃機関のＥＧＲ機
構において、バイパス通路による排気の圧力損失がＥＧ
Ｒクーラによる排気の圧力損失に比して小さくなるよう
バイパス通路及びＥＧＲクーラが構成されている場合に
は、固着検出手段は、全開制御時の吸入空気量と全閉制
御時の吸入空気量とが略等しく、全開制御時の吸入空気
量が正常時の吸入空気量と略等しく、更に全閉制御時の
吸入空気量が正常時の吸入空気量より少ないことを条件
に、バイパス制御弁が全開位置で固着していると判定す
ることができる。Therefore, in the EGR mechanism of the internal combustion engine according to the present invention, the exhaust gas pressure loss due to the bypass passage is EG.
When the bypass passage and the EGR cooler are configured so as to be smaller than the pressure loss of the exhaust gas due to the R cooler, the sticking detection means determines the intake air amount during the fully open control and the intake air amount during the fully closed control. Are approximately equal, the intake air amount during full open control is approximately equal to the normal intake air amount, and the intake air amount during full close control is less than the normal intake air amount, the bypass control valve is fully open. It can be determined that the position is fixed.
【００２３】次に、バイパス制御弁が全閉位置で固着し
ている状況下では、全開制御時及び全閉制御時の双方に
おいてバイパス制御弁の実際の開度が全閉となるため、
全開制御時の吸入空気量と全閉制御時の吸入空気量とが
略等しくなり、全閉制御時の吸入空気量が正常時の吸入
空気量と略等しくなり、更に全開制御時の吸入空気量が
正常時の吸入空気量と異なる量となる。Next, under the condition that the bypass control valve is stuck at the fully closed position, the actual opening of the bypass control valve is fully closed both during the fully open control and the fully closed control.
The intake air amount during full open control and the intake air amount during full close control are approximately equal, the intake air amount during full close control is approximately equal to the normal intake air amount, and the intake air amount during full open control is also Is an amount different from the intake air amount during normal operation.
【００２４】その際、バイパス通路による排気の圧力損
失がＥＧＲクーラによる排気の圧力損失に比して大きく
なるようバイパス通路及びＥＧＲクーラが構成されてい
ると、バイパス制御弁が正常である状況下において全開
制御時のＥＧＲガス量が全閉制御時のＥＧＲガス量より
少なくなり、それに応じて全開制御時の吸入空気量が全
閉制御時の吸入空気量より多くなるため、バイパス制御
弁が全閉位置で固着している状況下では全開制御時の吸
入空気量が正常時の吸入空気量より少なくなる。At this time, if the bypass passage and the EGR cooler are configured so that the pressure loss of the exhaust gas due to the bypass passage becomes larger than the pressure loss of the exhaust gas due to the EGR cooler, under the condition that the bypass control valve is normal. The EGR gas amount during full open control becomes less than the EGR gas amount during full close control, and the intake air amount during full open control becomes correspondingly larger than the intake air amount during full close control, so the bypass control valve is fully closed. In the case where the position is fixed, the intake air amount during the full-open control becomes smaller than the normal intake air amount.
【００２５】従って、本発明に係る内燃機関のＥＧＲ機
構において、バイパス通路による排気の圧力損失がＥＧ
Ｒクーラによる排気の圧力損失に比して大きくなるよう
バイパス通路及びＥＧＲクーラが構成されている場合に
は、固着検出手段は、全開制御時の吸入空気量と全閉制
御時の吸入空気量とが略等しく、全閉制御時の吸入空気
量が正常時の吸入空気量と略等しく、更に全開制御時の
吸入空気量が正常時の吸入空気量より少ないことを条件
に、バイパス制御弁が全閉位置で固着していると判定す
ることができる。Therefore, in the EGR mechanism of the internal combustion engine according to the present invention, the pressure loss of the exhaust gas due to the bypass passage is EG
When the bypass passage and the EGR cooler are configured so as to be larger than the pressure loss of the exhaust gas due to the R cooler, the sticking detection means determines the intake air amount during the fully open control and the intake air amount during the fully closed control. Are approximately equal, the intake air amount during full-closed control is approximately equal to the normal intake air amount, and the intake air amount during full-open control is less than the normal intake air amount. It can be determined that it is stuck in the closed position.
【００２６】一方、バイパス通路による排気の圧力損失
がＥＧＲクーラによる排気の圧力損失に比して小さくな
るようバイパス通路及びＥＧＲクーラが構成されている
と、バイパス制御弁が正常である状況下において全開制
御時のＥＧＲガス量が全閉制御時のＥＧＲガス量より多
くなり、それに応じて全開制御時の吸入空気量が全閉制
御時の吸入空気量より少なくなるため、バイパス制御弁
が全閉位置で固着している状況下では全開制御時の吸入
空気量が正常時の吸入空気量より多くなる。On the other hand, if the bypass passage and the EGR cooler are configured so that the pressure loss of the exhaust gas due to the bypass passage becomes smaller than the pressure loss of the exhaust gas due to the EGR cooler, the bypass control valve is fully opened under the normal condition. Since the EGR gas amount during control becomes greater than the EGR gas amount during fully closed control and the intake air amount during fully open control becomes smaller than the intake air amount during fully closed control accordingly, the bypass control valve is at the fully closed position. Under the situation that the intake air amount is stuck at, the intake air amount during the fully open control becomes larger than the normal intake air amount.
【００２７】従って、本発明に係る内燃機関のＥＧＲ機
構において、バイパス通路による排気の圧力損失がＥＧ
Ｒクーラによる排気の圧力損失に比して小さくなるよう
バイパス通路及びＥＧＲクーラが構成されている場合に
は、固着検出手段は、全開制御時の吸入空気量と全閉制
御時の吸入空気量とが略等しく、全閉制御時の吸入空気
量が正常時の吸入空気量と略等しく、更に全開制御時の
吸入空気量が正常時の吸入空気量より多いことを条件
に、バイパス制御弁が全閉位置で固着していると判定す
ることができる。Therefore, in the EGR mechanism of the internal combustion engine according to the present invention, the exhaust gas pressure loss due to the bypass passage is EG.
When the bypass passage and the EGR cooler are configured so as to be smaller than the pressure loss of the exhaust gas due to the R cooler, the sticking detection means determines the intake air amount during the fully open control and the intake air amount during the fully closed control. Are approximately equal, the intake air amount in the fully closed control is approximately equal to the normal intake air amount, and the intake air amount in the full open control is larger than the normal intake air amount, the bypass control valve is It can be determined that it is stuck in the closed position.
【００２８】バイパス制御弁が中開位置で固着している
状況下では、全開制御時及び全閉制御時の双方において
バイパス制御弁の実際の開度が中開位置で固定となり、
ＥＧＲガスがバイパス通路とＥＧＲクーラとの双方を流
れることになるため、全開制御時の吸入空気量と全閉制
御時の吸入空気量とが略等しくなり、全開制御時の吸入
空気量が正常時の吸入空気量と異なる量となり、更に全
閉制御時の吸入空気量が正常時の吸入空気量と異なる量
となる。Under the situation where the bypass control valve is stuck at the middle open position, the actual opening of the bypass control valve is fixed at the middle open position both during the full open control and the full close control.
Since the EGR gas flows through both the bypass passage and the EGR cooler, the intake air amount during the full-open control and the intake air amount during the full-close control become substantially equal, and the intake air amount during the full-open control is normal. Of intake air, and the intake air amount during full-closed control is different from the intake air amount during normal operation.
【００２９】従って、本発明に係る内燃機関のＥＧＲ機
構において、固着検出手段は、全開制御時の吸入空気量
と全閉制御時の吸入空気量とが略等しく、全開制御時の
吸入空気量が正常時の吸入空気量と異なり、更に全閉制
御時の吸入空気量が正常時の吸入空気量と異なることを
条件に、バイパス制御弁が中開位置で固着していると判
定することができる。Therefore, in the EGR mechanism of the internal combustion engine according to the present invention, the sticking detecting means has the intake air amount at the full open control and the intake air amount at the full close control substantially equal to each other, and the intake air amount at the full open control is It is possible to determine that the bypass control valve is stuck in the middle open position, provided that it differs from the intake air amount during normal operation and that the intake air amount during full-closed control differs from the intake air amount during normal operation. .
【００３０】また、本発明に係る内燃機関のＥＧＲ機構
は、内燃機関が低温燃焼運転と通常燃焼運転とを切換可
能な内燃機関である場合に固着検出手段によってバイパ
ス制御弁が全開位置で固着していると判定されると、内
燃機関を通常燃焼運転させるとともにＥＧＲ通路を流れ
るＥＧＲガス量を減少させるＥＧＲガス減量手段を更に
備えるようにしてもよい。Further, in the EGR mechanism of the internal combustion engine according to the present invention, when the internal combustion engine is an internal combustion engine capable of switching between the low temperature combustion operation and the normal combustion operation, the bypass control valve is stuck at the fully open position by the sticking detection means. When it is determined that the EGR gas is determined to be present, an EGR gas reducing means for reducing the amount of EGR gas flowing through the EGR passage while normally operating the internal combustion engine may be further provided.
【００３１】これは、バイパス制御弁が全開位置で固着
している場合は、全てのＥＧＲガスがＥＧＲクーラを迂
回して流れるため、比較的温度が高く且つ体積が大きな
ＥＧＲガスが内燃機関へ流入することとなり、圧縮端温
度の上昇や吸入空気量の減少による煤の発生などが誘発
される虞があるからである。This is because when the bypass control valve is stuck in the fully open position, all the EGR gas flows bypassing the EGR cooler, so that the EGR gas having a relatively high temperature and a large volume flows into the internal combustion engine. This is because the rise of the compression end temperature and the decrease of the intake air amount may induce soot and the like.
【００３２】また、本発明に係る内燃機関のＥＧＲ機構
は、内燃機関が低温燃焼運転と通常燃焼運転とを切換可
能である場合に固着検出手段によってバイパス制御弁が
全閉位置で固着していると判定されると、内燃機関の低
温燃焼運転時においてＥＧＲ通路を流れるＥＧＲガス量
を減少させるＥＧＲガス減量手段を更に備えるようにし
てもよい。Further, in the EGR mechanism of the internal combustion engine according to the present invention, when the internal combustion engine can switch between the low temperature combustion operation and the normal combustion operation, the bypass control valve is stuck at the fully closed position by the sticking detection means. If it is determined that the EGR gas reducing means is configured to reduce the EGR gas amount flowing through the EGR passage during the low temperature combustion operation of the internal combustion engine.
【００３３】これは、バイパス制御弁が全閉位置で固着
した場合は、全てのＥＧＲガスがＥＧＲクーラを流れる
ことにより内燃機関の圧縮端温度が低下し易いため、そ
の際に内燃機関が低温燃焼運転されていると、圧縮端温
度の過剰な低下により内燃機関の不完全燃焼や失火が誘
発される虞があるからである。特に、内燃機関の温度と
負荷と圧縮比との少なくとも一つが低い状態で低温燃焼
運転が行われている場合に、ＥＧＲクーラで冷却された
ＥＧＲガスが内燃機関へ導入されると、圧縮端温度の低
下が顕著となり、内燃機関が失火し易くなるため、ＥＧ
Ｒガス量を減少させることが好ましい。This is because when the bypass control valve is stuck in the fully closed position, all the EGR gas flows through the EGR cooler and the compression end temperature of the internal combustion engine is liable to drop. This is because during operation, incomplete combustion or misfire of the internal combustion engine may be induced due to excessive decrease in the compression end temperature. In particular, when the EGR gas cooled by the EGR cooler is introduced into the internal combustion engine when the low temperature combustion operation is performed in a state where at least one of the temperature, the load and the compression ratio of the internal combustion engine is low, the compression end temperature Is significantly reduced and the internal combustion engine is prone to misfire, so EG
It is preferable to reduce the amount of R gas.
【００３４】また、本発明に係る内燃機関のＥＧＲ機構
は、固着検出手段によってバイパス制御弁が中開位置で
固着していると判定された場合に、ＥＧＲ通路を流れる
ＥＧＲガス量を減量させるＥＧＲガス減量手段を更に備
えるようにしてもよい。Further, the EGR mechanism of the internal combustion engine according to the present invention reduces the amount of EGR gas flowing through the EGR passage when it is determined by the sticking detection means that the bypass control valve is stuck at the middle open position. You may make it further provide a gas reducing means.
【００３５】これは、バイパス制御弁が中開位置で固着
すると、ＥＧＲガスがＥＧＲクーラとバイパス通路との
双方を流通可能となり、内燃機関へ導入されるＥＧＲガ
ス量が不要に多くなり易いからである。This is because when the bypass control valve is stuck in the middle open position, EGR gas can flow through both the EGR cooler and the bypass passage, and the amount of EGR gas introduced into the internal combustion engine tends to increase unnecessarily. is there.
【００３６】また、本発明に係る内燃機関のＥＧＲ機構
において、内燃機関の排気系に設けられて排気中の微粒
子を捕集するパティキュレートフィルタと、パティキュ
レートフィルタに捕集された微粒子を除去して該パティ
キュレートフィルタの微粒子捕集能力を再生するフィル
タ再生手段とが更に備えられている場合には、フィルタ
再生手段によりパティキュレートフィルタの微粒子捕集
能力が再生された後の所定期間内にバイパス制御弁の固
着検出が行われるようにすることが好ましい。Further, in the EGR mechanism of the internal combustion engine according to the present invention, the particulate filter provided in the exhaust system of the internal combustion engine for collecting the particulates in the exhaust gas and the particulates collected by the particulate filter are removed. And a filter regenerating unit for regenerating the particulate collecting capability of the particulate filter, the bypass is performed within a predetermined period after the particulate regenerating capability of the particulate filter is regenerated by the filter regenerating unit. It is preferable that the sticking of the control valve is detected.
【００３７】これは、内燃機関の排気系にパティキュレ
ートフィルタが配置されている場合には、パティキュレ
ートフィルタに捕集されている微粒子量によってパティ
キュレートフィルタの圧力損失が変化し、それに応じて
内燃機関に作用する背圧が変化するとともに内燃機関の
吸入空気量が変化するため、パティキュレートフィルタ
に微粒子が捕集されている状況下でバイパス制御弁の固
着検出が行われると、吸入空気量の変化がバイパス制御
弁の固着に起因したものであるか、或いは、パティキュ
レートフィルタの微粒子捕集量に起因したものであるか
を判別することが困難となるからである。This is because, if a particulate filter is arranged in the exhaust system of the internal combustion engine, the pressure loss of the particulate filter changes depending on the amount of fine particles trapped in the particulate filter, and the internal combustion engine accordingly. Since the back pressure acting on the engine changes and the intake air amount of the internal combustion engine changes, if sticking detection of the bypass control valve is performed in a situation where particulates are trapped in the particulate filter, the intake air amount This is because it is difficult to determine whether the change is due to the sticking of the bypass control valve or the particulate collection amount of the particulate filter.
【００３８】また、本発明に係る内燃機関のＥＧＲ機構
において、排気中の微粒子を捕集するパティキュレート
フィルタが内燃機関の排気系に設けられている場合は、
バイパス制御弁の固着検出が行われる際に、内燃機関の
排気がパティキュレートフィルタを迂回して流れるよう
にすることが好ましい。Further, in the EGR mechanism of the internal combustion engine according to the present invention, when the particulate filter for collecting the particulates in the exhaust gas is provided in the exhaust system of the internal combustion engine,
It is preferable that the exhaust gas of the internal combustion engine flow around the particulate filter when the sticking detection of the bypass control valve is performed.
【００３９】これは、内燃機関の排気系にパティキュレ
ートフィルタが配置されている場合には、パティキュレ
ートフィルタに捕集されている微粒子量によってパティ
キュレートフィルタの圧力損失が変化し、それに応じて
内燃機関に作用する背圧が変化するとともに内燃機関の
吸入空気量が変化するため、内燃機関の排気がパティキ
ュレートフィルタを通過している状況下でバイパス制御
弁の固着検出が行われると、吸入空気量の変化がバイパ
ス制御弁の固着に起因したものであるか、或いは、パテ
ィキュレートフィルタの微粒子捕集量に起因したもので
あるかを判別することが困難となるからである。This is because when the particulate filter is arranged in the exhaust system of the internal combustion engine, the pressure loss of the particulate filter changes depending on the amount of fine particles trapped in the particulate filter, and the internal combustion engine accordingly. Since the back pressure acting on the engine changes and the intake air amount of the internal combustion engine changes, if the bypass control valve sticking detection is performed while the exhaust gas of the internal combustion engine is passing through the particulate filter, the intake air This is because it is difficult to determine whether the change in the amount is due to the sticking of the bypass control valve or the amount of particulate collection of the particulate filter.
【００４０】上記したパティキュレートフィルタとして
は、内燃機関の排気がパティキュレートフィルタを迂回
して流れるよう排気の流れを制御する排気流れ切換手段
を具備するパティキュレートフィルタを例示することが
できる。この場合、固着検出手段は、バイパス制御弁の
固着検出を行う際に、内燃機関の排気がパティキュレー
トフィルタを迂回して流れるよう排気流れ切換手段を制
御することが好適である。As the above-mentioned particulate filter, it is possible to exemplify a particulate filter equipped with an exhaust flow switching means for controlling the flow of the exhaust gas so that the exhaust gas of the internal combustion engine bypasses the particulate filter. In this case, it is preferable that the sticking detection means controls the exhaust flow switching means so that the exhaust gas of the internal combustion engine bypasses the particulate filter when the sticking detection of the bypass control valve is performed.
【００４１】また、本発明に係る内燃機関のＥＧＲ機構
において、排気の流量を絞るための排気絞り弁が内燃機
関の排気系に設けられている場合は、バイパス制御弁の
固着検出が行われる際に、前記排気絞り弁が全開とされ
ることが好ましい。Further, in the EGR mechanism of the internal combustion engine according to the present invention, when the exhaust throttle valve for throttling the flow rate of exhaust gas is provided in the exhaust system of the internal combustion engine, when the bypass control valve sticking detection is performed. In addition, it is preferable that the exhaust throttle valve be fully opened.
【００４２】これは、内燃機関の排気系に排気絞り弁が
配置されている場合には、排気絞り弁の開度によって内
燃機関に作用する背圧が変化し、それに応じて内燃機関
の吸入空気量が変化してしまうからである。This is because when the exhaust throttle valve is arranged in the exhaust system of the internal combustion engine, the back pressure acting on the internal combustion engine changes depending on the opening degree of the exhaust throttle valve, and the intake air of the internal combustion engine changes accordingly. This is because the amount will change.
【００４３】また、本発明に係る内燃機関のＥＧＲ機構
において、バイパス制御弁の固着検出を行う時期として
は、内燃機関の減速運転時、言い換えれば内燃機関のフ
ューエルカット制御が実行されている時を例示すること
ができる。Further, in the EGR mechanism of the internal combustion engine according to the present invention, the timing for detecting the sticking of the bypass control valve is during deceleration operation of the internal combustion engine, in other words, during the fuel cut control of the internal combustion engine. It can be illustrated.
【００４４】これは、内燃機関で混合気の燃焼が行われ
ている時に、バイパス制御弁が全開制御及び全閉制御さ
れると、内燃機関に吸入されるＥＧＲガス量及び吸入空
気量が変化するとともに、内燃機関に吸入されるＥＧＲ
ガスの温度が変化するため、内燃機関の運転状態が変化
してしまうことが想定されるからである。This is because when the bypass control valve is fully opened and fully closed while the mixture is being combusted in the internal combustion engine, the EGR gas amount and the intake air amount taken into the internal combustion engine change. Together with the EGR drawn into the internal combustion engine
This is because it is expected that the operating state of the internal combustion engine will change because the temperature of the gas changes.
【００４５】[0045]
【発明の実施の形態】以下、本発明に係る内燃機関のＥ
ＧＲ機構の具体的な実施態様について図面を参照しつつ
説明する。BEST MODE FOR CARRYING OUT THE INVENTION The internal combustion engine E according to the present invention
A specific embodiment of the GR mechanism will be described with reference to the drawings.
【００４６】＜実施の形態１＞先ず、本発明に係る内燃
機関のＥＧＲ機構の第１の実施の形態について図１〜図
５に基づいて説明する。<First Embodiment> First, a first embodiment of an EGR mechanism for an internal combustion engine according to the present invention will be described with reference to FIGS.
【００４７】図１は、本発明に係るＥＧＲ機構を適用す
る内燃機関の概略構成を示す図である。図１に示す内燃
機関１は、４つの気筒２を有する水冷式の４ストローク
・サイクルの圧縮着火式内燃機関（ディーゼル・エンジ
ン）である。FIG. 1 is a diagram showing a schematic structure of an internal combustion engine to which the EGR mechanism according to the present invention is applied. The internal combustion engine 1 shown in FIG. 1 is a water-cooled four-stroke cycle compression ignition type internal combustion engine (diesel engine) having four cylinders 2.
【００４８】内燃機関１は、各気筒２の燃焼室に直接燃
料を噴射する燃料噴射弁３を備えている。各燃料噴射弁
３は、燃料を所定圧まで蓄圧する蓄圧室（コモンレー
ル）４と接続されている。コモンレール４には、該コモ
ンレール４内の燃料の圧力に対応した電気信号を出力す
るコモンレール圧センサ４ａが取り付けられている。The internal combustion engine 1 is equipped with a fuel injection valve 3 for directly injecting fuel into the combustion chamber of each cylinder 2. Each fuel injection valve 3 is connected to a pressure accumulator (common rail) 4 that accumulates fuel to a predetermined pressure. A common rail pressure sensor 4a that outputs an electric signal corresponding to the pressure of the fuel in the common rail 4 is attached to the common rail 4.
【００４９】前記コモンレール４は、燃料供給管５を介
して燃料ポンプ６と連通している。燃料ポンプ６は、内
燃機関１の出力軸（クランクシャフト）の回転トルクを
駆動源として作動するポンプであり、該燃料ポンプ６の
入力軸に取り付けられたポンププーリ６ａが内燃機関１
の出力軸（クランクシャフト）に取り付けられたクラン
クプーリ１ａとベルト７を介して連結されている。The common rail 4 communicates with a fuel pump 6 via a fuel supply pipe 5. The fuel pump 6 is a pump that operates by using the rotational torque of the output shaft (crankshaft) of the internal combustion engine 1 as a drive source, and the pump pulley 6 a attached to the input shaft of the fuel pump 6 is the internal combustion engine 1.
Is connected to a crank pulley 1a attached to the output shaft (crank shaft) of the above through a belt 7.
【００５０】このように構成された燃料噴射系では、ク
ランクシャフトの回転トルクが燃料ポンプ６の入力軸へ
伝達されると、燃料ポンプ６は、クランクシャフトから
該燃料ポンプ６の入力軸へ伝達されたトルクを駆動源と
して作動し、図示しない吸入流量調整弁によって調量さ
れた所定量の燃料を吐出する。In the fuel injection system thus constructed, when the rotational torque of the crankshaft is transmitted to the input shaft of the fuel pump 6, the fuel pump 6 is transmitted from the crankshaft to the input shaft of the fuel pump 6. It operates by using the torque as a drive source and discharges a predetermined amount of fuel adjusted by an intake flow rate adjusting valve (not shown).
【００５１】前記燃料ポンプ６から吐出された燃料は、
燃料供給管５を介してコモンレール４へ供給され、コモ
ンレール４にて所定圧まで蓄圧されて各気筒２の燃料噴
射弁３へ分配される。そして、燃料噴射弁３に駆動電流
が印加されると、燃料噴射弁３が開弁し、その結果、燃
料噴射弁３から各気筒２の燃焼室へ燃料が噴射される。The fuel discharged from the fuel pump 6 is
It is supplied to the common rail 4 through the fuel supply pipe 5, accumulated in the common rail 4 up to a predetermined pressure, and distributed to the fuel injection valve 3 of each cylinder 2. When a drive current is applied to the fuel injection valve 3, the fuel injection valve 3 opens, and as a result, fuel is injected from the fuel injection valve 3 into the combustion chamber of each cylinder 2.
【００５２】次に、内燃機関１には、吸気枝管８が接続
されており、吸気枝管８の各枝管は、各気筒２の燃焼室
と図示しない吸気ポートを介して連通している。Next, an intake branch pipe 8 is connected to the internal combustion engine 1, and each branch pipe of the intake branch pipe 8 communicates with a combustion chamber of each cylinder 2 through an intake port (not shown). .
【００５３】前記吸気枝管８は、吸気管９に接続され、
この吸気管９は、エアクリーナボックス１０に接続され
ている。前記エアクリーナボックス１０より下流の吸気
管９には、該吸気管９内を流れる吸気の質量に対応した
電気信号を出力するエアフローメータ１１と、該吸気管
９内を流れる吸気の温度に対応した電気信号を出力する
吸気温度センサ１２とが取り付けられている。前記した
エアフローメータ１１は、本発明に係る吸入空気量検出
手段の一実施態様である。The intake branch pipe 8 is connected to the intake pipe 9,
The intake pipe 9 is connected to the air cleaner box 10. An air flow meter 11 for outputting an electric signal corresponding to the mass of the intake air flowing in the intake pipe 9 and an electric power corresponding to the temperature of the intake air flowing in the intake pipe 9 are provided in the intake pipe 9 downstream of the air cleaner box 10. An intake air temperature sensor 12 that outputs a signal is attached. The air flow meter 11 described above is an embodiment of the intake air amount detecting means according to the present invention.
【００５４】前記吸気管９における吸気枝管８の直上流
に位置する部位には、該吸気管９内を流れる吸気の流量
を調節する吸気絞り弁１３が設けられている。吸気絞り
弁１３には、ステッパモータ等で構成され、該吸気絞り
弁１３を開閉駆動する吸気絞り用アクチュエータ１４が
取り付けられている。An intake throttle valve 13 for adjusting the flow rate of the intake air flowing through the intake pipe 9 is provided at a portion of the intake pipe 9 located immediately upstream of the intake branch pipe 8. The intake throttle valve 13 is provided with an intake throttle actuator 14 which is composed of a stepper motor or the like and which drives the intake throttle valve 13 to open and close.
【００５５】前記エアフローメータ１１と前記吸気絞り
弁１３との間に位置する吸気管９には、排気の熱エネル
ギを駆動源として作動する遠心過給器（ターボチャージ
ャ）１５のコンプレッサハウジング１５ａが設けられ、
コンプレッサハウジング１５ａより下流の吸気管９に
は、前記コンプレッサハウジング１５ａ内で圧縮されて
高温となった吸気を冷却するためのインタークーラ１６
が設けられている。The intake pipe 9 located between the air flow meter 11 and the intake throttle valve 13 is provided with a compressor housing 15a of a centrifugal supercharger (turbocharger) 15 which operates by using heat energy of exhaust gas as a drive source. The
An intercooler 16 for cooling the intake air that has become hot due to being compressed in the compressor housing 15a is provided in the intake pipe 9 downstream of the compressor housing 15a.
Is provided.
【００５６】このように構成された吸気系では、エアク
リーナボックス１０に流入した吸気は、該エアクリーナ
ボックス１０内の図示しないエアフィルタによって吸気
中の塵や埃等が除去された後、吸気管９を介してコンプ
レッサハウジング１５ａに流入する。In the intake system configured as described above, the intake air flowing into the air cleaner box 10 is cleaned by the air filter (not shown) in the air cleaner box 10 to remove dust and the like from the intake air, and then the intake pipe 9 Through the compressor housing 15a.
【００５７】コンプレッサハウジング１５ａに流入した
吸気は、該コンプレッサハウジング１５ａに内装された
コンプレッサホイールの回転によって圧縮される。前記
コンプレッサハウジング１５ａ内で圧縮されて高温とな
った吸気は、インタークーラ１６にて冷却された後、必
要に応じて吸気絞り弁１３によって流量を調節されて吸
気枝管８に流入する。吸気枝管８に流入した吸気は、各
枝管を介して各気筒２の燃焼室へ分配され、各気筒２の
燃料噴射弁３から噴射された燃料を着火源として燃焼さ
れる。The intake air flowing into the compressor housing 15a is compressed by the rotation of the compressor wheel installed in the compressor housing 15a. The intake air, which has been compressed in the compressor housing 15a and has reached a high temperature, is cooled by the intercooler 16 and then flows into the intake branch pipe 8 with its flow rate adjusted by the intake throttle valve 13 if necessary. The intake air that has flowed into the intake branch pipe 8 is distributed to the combustion chamber of each cylinder 2 through each branch pipe, and is burned using the fuel injected from the fuel injection valve 3 of each cylinder 2 as an ignition source.
【００５８】一方、内燃機関１には、排気枝管１７が接
続され、排気枝管１７の各枝管が図示しない排気ポート
を介して各気筒２の燃焼室と連通している。On the other hand, an exhaust branch pipe 17 is connected to the internal combustion engine 1, and each branch pipe of the exhaust branch pipe 17 communicates with the combustion chamber of each cylinder 2 via an exhaust port (not shown).
【００５９】前記排気枝管１７は、前記遠心過給器１５
のタービンハウジング１５ｂと接続されている。前記タ
ービンハウジング１５ｂは、上流側排気管１８と接続さ
れ、この上流側排気管１８は、排気中の有害ガス成分を
除去およびまたは浄化する排気浄化機構２０に接続され
ている。前記排気浄化機構２０は下流側排気管１９に接
続され、下流側排気管１９はその下流にて図示しないマ
フラーに接続されている。The exhaust branch pipe 17 corresponds to the centrifugal supercharger 15.
Is connected to the turbine housing 15b. The turbine housing 15b is connected to an upstream exhaust pipe 18, and the upstream exhaust pipe 18 is connected to an exhaust purification mechanism 20 that removes and / or purifies harmful gas components in exhaust gas. The exhaust gas purification mechanism 20 is connected to a downstream side exhaust pipe 19, and the downstream side exhaust pipe 19 is connected to a muffler (not shown) downstream thereof.
【００６０】前記排気浄化機構２０は、図２に示すよう
に、排気中に含まれる煤やＳＯＦ（Soluble Organic Fr
action）等の微粒子（ＰＭ：Particulate Matter）を捕
集するパティキュレートフィルタ２００（以下、単にフ
ィルタ２００と記す）と、このパティキュレートフィル
タ２００を収容するケーシング２０１とを備えている。As shown in FIG. 2, the exhaust gas purification mechanism 20 includes soot and SOF (Soluble Organic Fr) contained in the exhaust gas.
A particulate filter 200 (hereinafter, simply referred to as a filter 200) that collects particulate matter (PM: Particulate Matter) such as an action), and a casing 201 that houses the particulate filter 200.
【００６１】前記ケーシング２０１は、筒状体で形成さ
れ、一方の開口端が上流側排気管１８と接続されるとと
もに他方の開口端が下流側排気管１９と接続されてい
る。The casing 201 is formed of a tubular body, one open end of which is connected to the upstream exhaust pipe 18 and the other open end of which is connected to the downstream exhaust pipe 19.
【００６２】前記したフィルタ２００は、例えば、一端
が閉塞され且つ他端が開放された排気通路と一端が開放
され且つ他端が閉塞された排気通路とが隔壁を介して交
互に且つハニカム状に配置された、コージェライト等の
ような多孔質の基材からなるウォールフロー型のフィル
タである。The filter 200 described above has, for example, an exhaust passage whose one end is closed and the other end is open and an exhaust passage whose one end is open and the other end is closed, which are alternately and honeycomb-shaped via partition walls. It is a wall-flow type filter made of a porous base material such as cordierite.
【００６３】前記した基材の隔壁の表面上及び隔壁の細
孔の内壁面には、アルミナ等からなる担体の層が形成さ
れており、この担体上に白金（Ｐｔ）に代表される酸化
触媒とカリウム（Ｋ）やセシウム（Ｃｓ）などに代表さ
れるＮＯx吸蔵剤とが担持されている。On the surface of the partition walls of the base material and on the inner wall surfaces of the pores of the partition walls, a carrier layer made of alumina or the like is formed, and an oxidation catalyst typified by platinum (Pt) is formed on the carrier. And a NOx storage agent represented by potassium (K) and cesium (Cs).
【００６４】ここで図１に戻り、前記下流側排気管１９
には、該下流側排気管１９内を流れる排気の流量を調節
する排気絞り弁２１が設けられている。排気絞り弁２１
には、ステッパモータ等で構成されて該排気絞り弁２１
を開閉駆動する排気絞り用アクチュエータ２２が取り付
けられている。Returning now to FIG. 1, the downstream side exhaust pipe 19
An exhaust throttle valve 21 for adjusting the flow rate of the exhaust gas flowing in the downstream exhaust pipe 19 is provided in the. Exhaust throttle valve 21
The exhaust throttle valve 21 is composed of a stepper motor or the like.
An exhaust throttle actuator 22 that opens and closes is attached.
【００６５】前記下流側排気管１９において前記排気浄
化機構２０と排気絞り弁２１との間の部位には、該下流
側排気管１９内を流れる排気中の酸素濃度に対応した電
気信号を出力する酸素濃度センサ２３が取り付けられる
とともに、該下流側排気管１９内を流れる排気の温度に
対応した電気信号を出力する排気温度センサ２４が取り
付けられている。An electric signal corresponding to the oxygen concentration in the exhaust gas flowing in the downstream side exhaust pipe 19 is output to a portion of the downstream side exhaust pipe 19 between the exhaust gas purification mechanism 20 and the exhaust throttle valve 21. An oxygen concentration sensor 23 is attached, and an exhaust temperature sensor 24 that outputs an electric signal corresponding to the temperature of the exhaust gas flowing in the downstream side exhaust pipe 19 is attached.
【００６６】このように構成された排気系では、内燃機
関１の各気筒２で燃焼された混合気（既燃ガス）が排気
ポートを介して排気枝管１７へ排出され、次いで排気枝
管１７から遠心過給器１５のタービンハウジング１５ｂ
へ流入する。タービンハウジング１５ｂに流入した排気
は、タービンハウジング１５ｂ内に回転自在に支持され
たタービンホイールを回転させる。その際、タービンホ
イールの回転トルクは、前述したコンプレッサハウジン
グ１５ａのコンプレッサホイールへ伝達されることにな
る。In the exhaust system configured as described above, the air-fuel mixture (burnt gas) burned in each cylinder 2 of the internal combustion engine 1 is discharged to the exhaust branch pipe 17 through the exhaust port, and then the exhaust branch pipe 17 is exhausted. From the turbine housing 15b of the centrifugal supercharger 15
Flow into. The exhaust gas that has flowed into the turbine housing 15b rotates a turbine wheel that is rotatably supported in the turbine housing 15b. At that time, the rotational torque of the turbine wheel is transmitted to the compressor wheel of the compressor housing 15a described above.
【００６７】前記タービンハウジング１５ｂから排出さ
れた排気は、上流側排気管１８を介してフィルタ２００
へ流入し、排気中の有害ガス成分が除去又は浄化され
る。フィルタ２００にて有害ガス成分を除去又は浄化さ
れた排気は、下流側排気管１９へ流入し、必要に応じて
排気絞り弁２１により流量を調節された後に大気中へ放
出される。The exhaust gas discharged from the turbine housing 15b is passed through the upstream side exhaust pipe 18 to the filter 200.
And the harmful gas components in the exhaust gas are removed or purified. The exhaust gas from which harmful gas components have been removed or purified by the filter 200 flows into the downstream side exhaust pipe 19, the flow rate of which is adjusted by the exhaust throttle valve 21 as necessary, and then the air is discharged into the atmosphere.
【００６８】また、前記した排気枝管１７と吸気枝管８
とは、排気枝管１７内を流れる排気の一部を吸気枝管８
へ還流させるＥＧＲ通路２５を介して連通されている。
ＥＧＲ通路２５の途中には、電磁弁などで構成され、印
加電力の大きさに応じて前記ＥＧＲ通路２５内を流れる
排気（以下、ＥＧＲガスと称する）の流量を変更する流
量調整弁（ＥＧＲ弁）２６が設けられている。The exhaust branch pipe 17 and the intake branch pipe 8 described above are also provided.
Means that a part of the exhaust gas flowing in the exhaust branch pipe 17 is taken as the intake branch pipe 8
They are communicated with each other via an EGR passage 25 that recirculates to.
A flow rate adjusting valve (EGR valve) configured by an electromagnetic valve or the like in the middle of the EGR passage 25 and changing the flow rate of exhaust gas (hereinafter, referred to as EGR gas) flowing in the EGR passage 25 in accordance with the magnitude of applied power. ) 26 are provided.
【００６９】前記ＥＧＲ通路２５においてＥＧＲ弁２６
より上流の部位には、該ＥＧＲ通路２５内を流れるＥＧ
Ｒガスを冷却するＥＧＲクーラ２７が設けられている。
更に、前記ＥＧＲ通路２５には、前記ＥＧＲクーラ２７
を迂回するバイパス通路２８が設けられている。前記バ
イパス通路２８と前記ＥＧＲ通路２５との接続部には、
バイパス通路２８を流通するＥＧＲガス量とＥＧＲクー
ラ２７を流通するＥＧＲガス量との流量比を調節するバ
イパス制御弁２９が設けられている。In the EGR passage 25, the EGR valve 26
The EG flowing in the EGR passage 25 is provided at a more upstream portion.
An EGR cooler 27 that cools the R gas is provided.
Further, in the EGR passage 25, the EGR cooler 27
A bypass passage 28 is provided for bypassing. At the connecting portion between the bypass passage 28 and the EGR passage 25,
A bypass control valve 29 is provided to adjust the flow rate ratio between the amount of EGR gas flowing in the bypass passage 28 and the amount of EGR gas flowing in the EGR cooler 27.
【００７０】このように構成された排気再循環機構で
は、ＥＧＲ弁２６が開弁されると、ＥＧＲ通路２５が導
通状態となり、排気枝管１７内を流れる排気の一部がＥ
ＧＲガスとして前記ＥＧＲ通路２５へ流入する。ＥＧＲ
通路２５へ流入したＥＧＲガスは、ＥＧＲクーラ２７お
よびまたはバイパス通路２８を経由して吸気枝管８へ還
流される。In the exhaust gas recirculation mechanism thus constructed, when the EGR valve 26 is opened, the EGR passage 25 becomes conductive, and a part of the exhaust gas flowing in the exhaust branch pipe 17 becomes E.
It flows into the EGR passage 25 as GR gas. EGR
The EGR gas flowing into the passage 25 is returned to the intake branch pipe 8 via the EGR cooler 27 and / or the bypass passage 28.
【００７１】ＥＧＲ通路２５を介して排気枝管１７から
吸気枝管８へ還流されたＥＧＲガスは、吸気枝管８の上
流から流れてきた新気と混ざり合いつつ各気筒２の燃焼
室へ導かれ、燃料噴射弁３から噴射される燃料を着火源
として燃焼される。The EGR gas recirculated from the exhaust branch pipe 17 to the intake branch pipe 8 through the EGR passage 25 is introduced into the combustion chamber of each cylinder 2 while being mixed with the fresh air flowing from the upstream side of the intake branch pipe 8. Then, the fuel injected from the fuel injection valve 3 is used as an ignition source for combustion.
【００７２】ここで、ＥＧＲガスには、水（Ｈ2Ｏ）や
二酸化炭素（ＣＯ2）などの不活性ガス成分が含まれて
いるため、ＥＧＲガスが混合気中に含有されると、混合
気の燃焼温度が低められ、以て窒素酸化物（ＮＯx）の
発生量が抑制される。Since the EGR gas contains an inert gas component such as water (H 2 O) and carbon dioxide (CO 2 ), if the EGR gas is contained in the mixture, The combustion temperature of the air is lowered, and thus the amount of nitrogen oxides (NOx) generated is suppressed.
【００７３】その際、ＥＧＲクーラ２７においてＥＧＲ
ガスが冷却されていると、ＥＧＲガス自体の温度が低下
するとともにＥＧＲガスの体積が縮小されるため、ＥＧ
Ｒガスが燃焼室内に供給されたときに該燃焼室内の雰囲
気温度が不要に上昇することがなくなるとともに、燃焼
室内に供給される新気の量（新気の体積）が不要に減少
することもなくなる。At that time, in the EGR cooler 27, the EGR
When the gas is cooled, the temperature of the EGR gas itself is lowered and the volume of the EGR gas is reduced.
When the R gas is supplied into the combustion chamber, the atmospheric temperature in the combustion chamber does not unnecessarily rise, and the amount of fresh air (volume of fresh air) supplied into the combustion chamber is unnecessarily reduced. Disappear.
【００７４】上記したように構成された内燃機関１に
は、該内燃機関１を制御するための電子制御ユニット
（ＥＣＵ：Electronic Control Unit）３０が併設され
ている。ＥＣＵ３０は、内燃機関１の運転条件や運転者
の要求に応じて内燃機関１の運転状態を制御する算術論
理演算回路である。The internal combustion engine 1 configured as described above is provided with an electronic control unit (ECU) 30 for controlling the internal combustion engine 1. The ECU 30 is an arithmetic logic operation circuit that controls the operating state of the internal combustion engine 1 according to the operating conditions of the internal combustion engine 1 and the driver's request.
【００７５】ＥＣＵ３０には、コモンレール圧センサ４
ａ、エアフローメータ１１、吸気温度センサ１２、酸素
濃度センサ２３、排気温度センサ２４に加え、車室内に
設けられた図示しないアクセルペダルの操作量に対応し
た電気信号を出力するアクセル開度センサ３１や、内燃
機関１に取り付けられたクランクポジションセンサ３３
及び水温センサ３４等が電気的に接続され、上記した各
種センサの出力信号がＥＣＵ３０に入力されるようにな
っている。The ECU 30 includes the common rail pressure sensor 4
a, an air flow meter 11, an intake air temperature sensor 12, an oxygen concentration sensor 23, an exhaust gas temperature sensor 24, an accelerator opening sensor 31 for outputting an electric signal corresponding to an operation amount of an accelerator pedal (not shown) provided in the vehicle compartment, , A crank position sensor 33 attached to the internal combustion engine 1
The water temperature sensor 34 and the like are electrically connected, and the output signals of the various sensors described above are input to the ECU 30.
【００７６】一方、ＥＣＵ３０には、燃料噴射弁３、吸
気絞り用アクチュエータ１４、排気絞り用アクチュエー
タ２２、ＥＧＲ弁２６、バイパス制御弁２９等が電気的
に接続され、ＥＣＵ３０が上記した各部を制御すること
が可能となっている。On the other hand, the ECU 30 is electrically connected to the fuel injection valve 3, the intake throttle actuator 14, the exhaust throttle actuator 22, the EGR valve 26, the bypass control valve 29, etc., and the ECU 30 controls the above-mentioned respective parts. It is possible.
【００７７】ここで、ＥＣＵ３０は、図３に示すよう
に、双方向性バス３００によって相互に接続された、Ｃ
ＰＵ３０１と、ＲＯＭ３０２と、ＲＡＭ３０３と、バッ
クアップＲＡＭ３０４と、入力ポート３０６と、出力ポ
ート３０７とを備えるとともに、前記入力ポート３０６
に接続されたＡ／Ｄコンバータ（Ａ／Ｄ）３０５を備え
ている。Here, as shown in FIG. 3, the ECU 30 is connected to the C
The input port 306 includes a PU 301, a ROM 302, a RAM 303, a backup RAM 304, an input port 306, and an output port 307.
And an A / D converter (A / D) 305 connected to.
【００７８】前記入力ポート３０６は、クランクポジシ
ョンセンサ３３のようにデジタル信号形式の信号を出力
するセンサの出力信号を入力し、それらの出力信号をＣ
ＰＵ３０１やＲＡＭ３０３へ送信する。The input port 306 inputs the output signals of a sensor such as the crank position sensor 33 which outputs a digital signal format signal, and outputs those output signals to C
It is transmitted to the PU 301 and the RAM 303.
【００７９】前記入力ポート３０６は、コモンレール圧
センサ４ａ、エアフローメータ１１、吸気温度センサ１
２、酸素濃度センサ２３、排気温度センサ２４、アクセ
ル開度センサ３１、水温センサ３４等のように、アナロ
グ信号形式の信号を出力するセンサの出力信号をＡ／Ｄ
３０５を介して入力し、それらの出力信号をＣＰＵ３０
１やＲＡＭ３０３へ送信する。The input port 306 includes the common rail pressure sensor 4a, the air flow meter 11, and the intake air temperature sensor 1.
2. The output signals of the sensors that output analog signal format signals such as the oxygen concentration sensor 23, the exhaust gas temperature sensor 24, the accelerator opening sensor 31, the water temperature sensor 34, etc. are A / D.
Input through 305 and output signals of them via the CPU 30.
1 or to the RAM 303.
【００８０】前記出力ポート３０７は、燃料噴射弁３、
吸気絞り用アクチュエータ１４、排気絞り用アクチュエ
ータ２２、ＥＧＲ弁２６、バイパス制御弁２９等と電気
配線を介して接続され、ＣＰＵ３０１から出力される制
御信号を、前記した燃料噴射弁３、吸気絞り用アクチュ
エータ１４、排気絞り用アクチュエータ２２、ＥＧＲ弁
２６、或いはバイパス制御弁２９へ送信する。The output port 307 is connected to the fuel injection valve 3,
The control signal output from the CPU 301 is connected to the intake throttle actuator 14, the exhaust throttle actuator 22, the EGR valve 26, the bypass control valve 29, and the like via electrical wiring, and the control signal output from the CPU 301 is used as described above. 14, the exhaust throttle actuator 22, the EGR valve 26, or the bypass control valve 29.
【００８１】前記ＲＯＭ３０２は、燃料噴射弁３を制御
するための燃料噴射制御ルーチン、吸気絞り弁１３を制
御するための吸気絞り制御ルーチン、排気絞り弁２１を
制御するための排気絞り制御ルーチン、ＥＧＲ弁２６及
びバイパス制御弁２９を制御するためのＥＧＲ制御ルー
チン等のアプリケーションプログラムに加え、各種の制
御マップを記憶している。The ROM 302 includes a fuel injection control routine for controlling the fuel injection valve 3, an intake throttle control routine for controlling the intake throttle valve 13, an exhaust throttle control routine for controlling the exhaust throttle valve 21, and an EGR. In addition to an application program such as an EGR control routine for controlling the valve 26 and the bypass control valve 29, various control maps are stored.
【００８２】前記ＲＡＭ３０３は、各センサからの出力
信号やＣＰＵ３０１の演算結果等を格納する。前記演算
結果は、例えば、クランクポジションセンサ３３がパル
ス信号を出力する時間的な間隔に基づいて算出される機
関回転数である。これらのデータは、クランクポジショ
ンセンサ３３がパルス信号を出力する都度、最新のデー
タに書き換えられる。The RAM 303 stores the output signal from each sensor, the calculation result of the CPU 301, and the like. The calculation result is, for example, the engine speed calculated based on the time interval at which the crank position sensor 33 outputs a pulse signal. These data are rewritten to the latest data each time the crank position sensor 33 outputs a pulse signal.
【００８３】前記バックアップＲＡＭ３０４は、内燃機
関１の運転停止後もデータを記憶可能な不揮発性のメモ
リである。The backup RAM 304 is a non-volatile memory capable of storing data even after the internal combustion engine 1 is stopped.
【００８４】前記ＣＰＵ３０１は、前記ＲＯＭ３０２に
記憶されたアプリケーションプログラムに従って動作
し、燃料噴射弁制御、吸気絞り制御、排気絞り制御、及
びＥＧＲ制御などの既知の制御に加え、本発明の要旨と
なる固着検出制御を実行する。The CPU 301 operates in accordance with an application program stored in the ROM 302, and in addition to known controls such as fuel injection valve control, intake throttle control, exhaust throttle control, and EGR control, the fixation which is the gist of the present invention. Perform detection control.
【００８５】以下、本実施の形態における固着検出制御
について説明する。固着検出制御では、ＣＰＵ３０１
は、バイパス制御弁２９を全開に制御するとともに全閉
に制御し、全開制御時と全閉制御時との各々においてエ
アフローメータ１１が出力した信号値をパラメータとし
てバイパス制御弁２９が固着しているか否かを判別する
とともに、バイパス制御弁２９の固着が検出された場合
には固着の態様に応じて内燃機関１の運転状態やＥＧＲ
ガスの還流量を制御する。The sticking detection control according to this embodiment will be described below. In the sticking detection control, the CPU 301
Controls whether the bypass control valve 29 is fully opened and fully closed, and whether the bypass control valve 29 is fixed using the signal value output by the air flow meter 11 as a parameter in each of the fully open control and the fully closed control. When it is determined that the bypass control valve 29 is stuck, the operating state of the internal combustion engine 1 and the EGR are determined according to the sticking mode.
Controls the amount of gas reflux.
【００８６】尚、バイパス制御弁２９の全開とは、ＥＧ
Ｒクーラ２７が遮断され且つバイパス通路２８が導通し
た時のバイパス制御弁２９の開度を示し、バイパス制御
弁２９の全閉とは、ＥＧＲクーラ２７が導通し且つバイ
パス通路２８が遮断された時のバイパス制御弁２９の開
度を示すものとする。The full opening of the bypass control valve 29 means EG
It indicates the opening degree of the bypass control valve 29 when the R cooler 27 is cut off and the bypass passage 28 is turned on. The full closing of the bypass control valve 29 means that the EGR cooler 27 is turned on and the bypass passage 28 is cut off. It indicates the opening degree of the bypass control valve 29.
【００８７】バイパス制御弁２９が固着しているか否か
を判別する具体的な方法としては、バイパス制御弁２９
の全開制御時におけるエアフローメータ１１の出力信号
値（以下、全開時実吸入空気量と称する）と、バイパス
制御弁２９の全閉制御時におけるエアフローメータ１１
の出力信号値（以下、全閉時実吸入空気量と称する）と
を比較し、それら全開時実吸入空気量と全閉時実吸入空
気量とが略同量である場合にはバイパス制御弁２９が固
着していると判定し、全開時実吸入空気量と全閉時実吸
入空気量とが異なる量である場合にはバイパス制御弁２
９が固着していないと判定する方法を例示することがで
きる。A specific method for determining whether or not the bypass control valve 29 is stuck is as follows.
Of the output signal of the air flow meter 11 during the full open control (hereinafter referred to as the actual intake air amount during full open) and the air flow meter 11 during the full close control of the bypass control valve 29.
Output signal value (hereinafter referred to as the actual intake air amount when fully closed) is compared, and if the actual intake air amount when fully opened and the actual intake air amount when fully closed are approximately the same amount, the bypass control valve If it is determined that 29 is stuck, and the actual intake air amount when fully opened and the actual intake air amount when fully closed are different amounts, the bypass control valve 2
It is possible to exemplify a method of determining that 9 is not fixed.
【００８８】バイパス制御弁２９が正常に動作可能な状
態にあると、バイパス制御弁２９の全開制御時には全て
のＥＧＲガスがバイパス通路２８を流れる一方、バイパ
ス制御弁２９の全閉制御時には全てのＥＧＲガスがＥＧ
Ｒクーラ２７を流れることになる。When the bypass control valve 29 is in a normally operable state, all EGR gas flows through the bypass passage 28 when the bypass control valve 29 is fully opened, while all EGR gas is flown when the bypass control valve 29 is fully closed. Gas is EG
It will flow through the R cooler 27.
【００８９】その際、ＥＧＲクーラ２７による排気の圧
力損失とバイパス通路２８による排気の圧力損失とが異
なるため、全開制御時において単位時間当たりに流れる
ＥＧＲガス量と、全閉制御時において単位時間当たりに
流れるＥＧＲガス量とが異なる量となり、それに対応し
て全開時実吸入空気量と全閉時実吸入空気量とが異なる
量となる。例えば、ＥＧＲクーラ２７による排気の圧力
損失がバイパス通路２８による排気の圧力損失に比して
少ない場合には、全開制御時において単位時間当たりに
流れるＥＧＲガス量は、全閉制御時において単位時間当
たりに流れるＥＧＲガス量より少なくなり、それに対応
して全開時実吸入空気量が全閉時実吸入空気量より多く
なる。At this time, since the pressure loss of the exhaust gas due to the EGR cooler 27 and the pressure loss of the exhaust gas due to the bypass passage 28 are different, the amount of EGR gas flowing per unit time during the fully open control and the unit time per unit time during the fully closed control. The amount of EGR gas flowing through the valve is different, and the amount of actual intake air at full open is different from the amount of actual intake air at fully closed correspondingly. For example, when the pressure loss of the exhaust gas due to the EGR cooler 27 is smaller than the pressure loss of the exhaust gas due to the bypass passage 28, the amount of EGR gas flowing per unit time during the full opening control is per unit time during the full closing control. The amount of EGR gas flowing through the valve is less than the amount of EGR gas flowing therethrough, and correspondingly, the actual intake air amount at the time of full opening becomes larger than the actual intake air amount at the time of fully closing.
【００９０】ＥＧＲクーラ２７による排気の圧力損失が
バイパス通路２８による排気の圧力損失に比して多い場
合には、全開制御時において単位時間当たりに流れるＥ
ＧＲガス量は、全閉制御時において単位時間当たりに流
れるＥＧＲガス量より多くなり、それに対応して全開時
実吸入空気量が全閉時実吸入空気量より少なくなる。When the pressure loss of the exhaust gas due to the EGR cooler 27 is larger than the pressure loss of the exhaust gas due to the bypass passage 28, E flowing per unit time during the full opening control
The GR gas amount becomes larger than the EGR gas amount flowing per unit time during the fully closed control, and the fully open actual intake air amount correspondingly becomes smaller than the fully closed actual intake air amount.
【００９１】一方、バイパス制御弁２９が固着して動作
不能な状態にあると、全開制御時にＥＧＲガスが流れる
経路と全閉制御時にＥＧＲガスが流れる経路とが同一の
経路となるため、それに対応して全開時実吸入空気量と
全閉時実吸入空気量とが略同一の量となる。On the other hand, when the bypass control valve 29 is stuck and inoperable, the path through which the EGR gas flows during the full open control and the path through which the EGR gas flows during the full close control are the same. Then, the actual intake air amount when fully opened and the actual intake air amount when fully closed become substantially the same amount.
【００９２】従って、全開時実吸入空気量と全閉時実吸
入空気量とが異なる場合にはバイパス制御弁２９が固着
していないと判定し、全開時実吸入空気量と全閉時実吸
入空気量とが略同量である場合にはバイパス制御弁２９
が固着していると判定することができる。Therefore, when the actual intake air amount at full open and the actual intake air amount at full close are different, it is determined that the bypass control valve 29 is not stuck, and the actual intake air amount at full open and the actual intake air at full close are determined. When the amount of air is substantially the same, the bypass control valve 29
Can be determined to be fixed.
【００９３】次に、バイパス制御弁２９が固着している
と判定された場合に、その固着の態様を判別する方法に
ついて述べる。Next, a method of discriminating the mode of the sticking when the bypass control valve 29 is judged to be stuck will be described.
【００９４】バイパス制御弁２９が固着する態様として
は、全開位置で固着している態様と、全閉位置で固着し
ている態様と、中開位置で固着している態様とが考えら
れる。As a mode in which the bypass control valve 29 is fixed, a mode in which it is fixed in the fully open position, a mode in which it is fixed in the fully closed position, and a mode in which it is fixed at the medium open position are considered.
【００９５】そこで、上記した三つの固着態様を判別す
る方法について、ＥＧＲクーラ２７による排気の圧力損
失がバイパス通路２８による排気の圧力損失に比して少
ない場合と、ＥＧＲクーラ２７による排気の圧力損失が
バイパス通路２８による排気の圧力損失に比して多い場
合との各々の場合について説明する。Therefore, regarding the above three methods of determining the sticking mode, when the pressure loss of the exhaust gas by the EGR cooler 27 is smaller than the pressure loss of the exhaust gas by the bypass passage 28, and when the pressure loss of the exhaust gas by the EGR cooler 27 is smaller. Each of the case where the amount is larger than the pressure loss of the exhaust gas due to the bypass passage 28 will be described.
【００９６】（１）ＥＧＲクーラ２７の圧力損失がバイ
パス通路２８の圧力損失に比して少ない場合
この場合は、バイパス制御弁２９が全開であるときに単
位時間当たりに流れるＥＧＲガス量は、バイパス制御弁
２９の全閉であるときに単位時間当たりに流れるＥＧＲ
ガス量に比して少なくなるため、バイパス制御弁２９が
正常に動作可能であれば全開時実吸入空気量が全閉時実
吸入空気量に比して多くなる（全開時実吸入空気量＞全
閉時実吸入空気量）。 (1) The pressure loss of the EGR cooler 27 is
When the bypass control valve 29 is fully open, the amount of EGR gas flowing per unit time when the bypass control valve 29 is fully open is equal to the pressure loss of the bypass passage 28 per unit time. EGR flowing in
Since the amount is smaller than the gas amount, if the bypass control valve 29 can operate normally, the actual intake air amount at full opening will be larger than the actual intake air amount at fully closing (actual intake air amount at full opening> Actual intake air amount when fully closed).
【００９７】これに対し、バイパス制御弁２９が全開位
置で固着している場合は、全開制御時と全閉制御時との
双方においてバイパス制御弁２９が全開となるため、全
開時実吸入空気量はバイパス制御弁２９が正常に全開と
された時の吸入空気量（以下、正常全開時吸入空気量と
称する）と略同一の量となるが、全閉時実吸入空気量は
バイパス制御弁２９が正常に全閉とされた時の吸入空気
量（以下、正常全閉時吸入空気量と称する）より多くな
る。On the other hand, when the bypass control valve 29 is stuck at the fully open position, the bypass control valve 29 is fully opened both at the time of the fully open control and at the time of the fully closed control. Is substantially the same as the intake air amount when the bypass control valve 29 is normally fully opened (hereinafter referred to as the normally fully open intake air amount), but the fully closed actual intake air amount is the bypass control valve 29. Is larger than the intake air amount when the valve is normally fully closed (hereinafter, referred to as the normally fully closed intake air amount).
【００９８】バイパス制御弁２９が全閉位置で固着して
いる場合は、全開制御時と全閉制御時との双方において
バイパス制御弁２９が全閉となるため、全閉時実吸入空
気量は正常全閉時吸入空気量と略同一の量となるが、全
開時実吸入空気量は正常全開時吸入空気量より少なくな
る。When the bypass control valve 29 is stuck in the fully closed position, the bypass control valve 29 is fully closed both during the fully open control and the fully closed control. The intake air amount is approximately the same as the normal fully closed intake air amount, but the actual fully open intake air amount is less than the normally fully open intake air amount.
【００９９】バイパス制御弁２９が中開位置で固着して
いる場合は、全開制御時と全閉制御時との双方において
ＥＧＲクーラ２７及びバイパス通路２８が導通状態とな
るため、全開時実吸入空気量が正常全開時実吸入空気量
と異なる量になるとともに、全閉時実吸入空気量が正常
全閉時実吸入量と異なる量になる。When the bypass control valve 29 is stuck in the middle open position, the EGR cooler 27 and the bypass passage 28 become conductive during both the full open control and the full close control, so that the actual intake air at the full open is obtained. The amount is different from the normal fully open actual intake air amount, and the fully closed actual intake air amount is different from the normal fully closed actual intake amount.
【０１００】従って、ＣＰＵ３０１は、全開時実吸入空
気量が正常全開時吸入空気量と略同量であり且つ全閉時
実吸入空気量が正常全閉時吸入空気量より多い場合はバ
イパス制御弁２９が全開固着していると判定し、全開時
実吸入空気量が正常全開時吸入空気量より少なく且つ全
閉時実吸入空気量が正常全閉時吸入空気量と略同量であ
る場合はバイパス制御弁２９が全閉固着していると判定
し、全開時実吸入空気量が正常全開時吸入空気量と異な
り且つ全閉時実吸入空気量が正常全閉時吸入空気量と異
なる場合はバイパス制御弁２９が中開固着していると判
定することができる。Therefore, the CPU 301, when the actual intake air amount at full opening is approximately the same as the normal intake air amount at full opening and the actual intake air amount at fully closed is greater than the normal fully closed intake air amount, the bypass control valve. When it is determined that 29 is fully open, and the actual intake air amount at full open is less than the normal intake air amount at full open and the actual intake air amount at full close is approximately the same as the normal full intake air amount. When it is determined that the bypass control valve 29 is fully closed and stuck, and the actual intake air amount at full open differs from the normal intake air amount at full open and the actual intake air amount at full close differs from the normal intake air amount at full close. It can be determined that the bypass control valve 29 is stuck in the middle position.
【０１０１】（２）ＥＧＲクーラ２７の圧力損失がバイ
パス通路２８の圧力損失に比して多い場合
この場合は、バイパス制御弁２９が全開であるときに単
位時間当たりに流れるＥＧＲガス量は、バイパス制御弁
２９の全閉であるときに単位時間当たりに流れるＥＧＲ
ガス量に比して多くなるため、バイパス制御弁２９が正
常に動作可能であれば全開時実吸入空気量が全閉時実吸
入空気量に比して少なくなる（全開時実吸入空気量＜全
閉時実吸入空気量）。 (2) The pressure loss of the EGR cooler 27 is
When the bypass control valve 29 is fully opened, the amount of EGR gas flowing per unit time when the bypass control valve 29 is fully opened is larger than the pressure loss in the pass passage 28. EGR flowing in
Since the amount becomes larger than the gas amount, if the bypass control valve 29 can operate normally, the actual intake air amount at full opening becomes smaller than the actual intake air amount at fully closing (actual intake air amount at full opening < Actual intake air amount when fully closed).
【０１０２】これに対し、バイパス制御弁２９が全開位
置で固着している場合は、全開制御時と全閉制御時との
双方においてバイパス制御弁２９が全開となるため、全
開時実吸入空気量は正常全開時吸入空気量と略同一の量
となるが、全閉時実吸入空気量は正常全閉時吸入空気量
より少なくなる。On the other hand, when the bypass control valve 29 is stuck at the fully open position, the bypass control valve 29 is fully opened both during the fully open control and the fully closed control. Is approximately the same as the normally fully open intake air amount, but the fully closed actual intake air amount is smaller than the normally fully closed intake air amount.
【０１０３】バイパス制御弁２９が全閉位置で固着して
いる場合は、全開制御時と全閉制御時との双方において
バイパス制御弁２９が全閉となるため、全閉時実吸入空
気量は正常全閉時吸入空気量と略同一の量となるが、全
開時実吸入空気量は正常全開時吸入空気量より多くな
る。When the bypass control valve 29 is stuck in the fully closed position, the bypass control valve 29 is fully closed during both the fully open control and the fully closed control. Although the intake air amount is approximately the same as the normally fully closed intake air amount, the fully opened actual intake air amount is larger than the normally fully opened intake air amount.
【０１０４】バイパス制御弁２９が中開位置で固着して
いる場合は、全開制御時と全閉制御時との双方において
ＥＧＲクーラ２７及びバイパス通路２８が導通状態とな
るため、全開時実吸入空気量が正常全開時実吸入空気量
と異なる量になるとともに、全閉時実吸入空気量が正常
全閉時実吸入量と異なる量になる。When the bypass control valve 29 is stuck in the middle open position, the EGR cooler 27 and the bypass passage 28 become conductive during both the full open control and the full close control. The amount is different from the normal fully open actual intake air amount, and the fully closed actual intake air amount is different from the normal fully closed actual intake amount.
【０１０５】従って、ＣＰＵ３０１は、全開時実吸入空
気量が正常全開時吸入空気量と略同量であり且つ全閉時
実吸入空気量が正常全閉時吸入空気量より少ない場合は
バイパス制御弁２９が全開固着していると判定し、全開
時実吸入空気量が正常全開時吸入空気量より多く且つ全
閉時実吸入空気量が正常全閉時吸入空気量と略同量であ
る場合はバイパス制御弁２９が全閉固着していると判定
し、全開時実吸入空気量が正常全開時吸入空気量と異な
り且つ全閉時実吸入空気量が正常全閉時吸入空気量と異
なる場合はバイパス制御弁２９が中開固着していると判
定することができる。Therefore, the CPU 301, when the actual intake air amount at full open is substantially the same as the normal intake air amount at full open and the actual intake air amount at full close is smaller than the normal fully closed intake air amount, the bypass control valve. When it is determined that 29 is fully open and stuck, and the actual intake air amount at full open is larger than the normal intake air amount at full open and the actual intake air amount at full close is approximately the same as the normal full intake air amount. When it is determined that the bypass control valve 29 is fully closed and stuck, and the actual intake air amount at full open differs from the normal intake air amount at full open and the actual intake air amount at full close differs from the normal intake air amount at full close. It can be determined that the bypass control valve 29 is stuck in the middle position.
【０１０６】上記したような（１）或いは（２）の判別
方法によれば、全開時実吸入空気量と全閉時実吸入空気
量とをパラメータとして、バイパス制御弁２９の固着の
態様を判別することが可能となる。According to the determination method of (1) or (2) as described above, the manner of sticking of the bypass control valve 29 is determined using the actual intake air amount at full open and the actual intake air amount at full close as parameters. It becomes possible to do.
【０１０７】ところで、内燃機関１の吸入空気量は、バ
イパス制御弁２９の開度以外の条件によっても変化する
可能性があるため、それらの条件に起因した誤判定を防
止するためには、全開制御時実吸入空気量、全閉制御時
実吸入空気量、正常全開時吸入空気量、及び正常全閉時
吸入空気量が検出される際の条件を同一にする必要があ
る。By the way, the intake air amount of the internal combustion engine 1 may change depending on conditions other than the opening degree of the bypass control valve 29. Therefore, in order to prevent erroneous determination due to those conditions, the full opening is required. The conditions under which the actual intake air amount during control, the actual intake air amount during full-closed control, the normal intake air amount during full opening, and the normal full-closing intake air amount must be detected must be the same.
【０１０８】内燃機関１の吸入空気量を変化させる主な
条件としては、吸気絞り弁１３の開度及びＥＧＲ弁２６
の開度を例示することができる。更に、本実施の形態に
おける内燃機関１のように排気絞り弁２１やフィルタ２
００を備えた内燃機関では、排気絞り弁の開度やフィル
タ２００の詰まり度合いによっても内燃機関の吸入空気
量が変化する。The main conditions for changing the intake air amount of the internal combustion engine 1 are the opening degree of the intake throttle valve 13 and the EGR valve 26.
The opening degree of can be illustrated. Further, like the internal combustion engine 1 in the present embodiment, the exhaust throttle valve 21 and the filter 2
In the internal combustion engine equipped with No. 00, the intake air amount of the internal combustion engine also changes depending on the opening degree of the exhaust throttle valve and the degree of clogging of the filter 200.
【０１０９】そこで、本実施の形態では、ＣＰＵ３０１
は、フィルタ２００にＰＭが捕集されていない時期に、
吸気絞り弁１３、ＥＧＲ弁２６、及び排気絞り弁２１を
全開に制御した上でバイパス制御弁２９の固着検出制御
を実行するようにした。Therefore, in the present embodiment, the CPU 301
Is when the PM is not collected in the filter 200,
The intake throttle valve 13, the EGR valve 26, and the exhaust throttle valve 21 are controlled to be fully opened, and then the sticking detection control of the bypass control valve 29 is executed.
【０１１０】フィルタ２００にＰＭが捕集されていない
時期としては、ＰＭが燃焼し得る温度域（例えば、５０
０℃〜７００℃）までフィルタ２００内の温度が高めら
れるＰＭ再生処理やＳＯx被毒解消処理が実行された直
後の所定期間内を例示することができる。The time when the PM is not collected by the filter 200 is a temperature range where the PM can burn (for example, 50 PM).
It is possible to exemplify within a predetermined period immediately after the PM regeneration process or the SOx poisoning elimination process in which the temperature in the filter 200 is raised to 0 ° C. to 700 ° C.).
【０１１１】但し、ＰＭ再生処理又はＳＯx被毒解消処
理が実行された直後の所定期間であっても、内燃機関１
において燃料の燃焼が行われている場合（例えば、内燃
機関１がアイドル運転状態、加速運転状態、或いは定常
運転状態にある場合）に、不用意に吸気絞り弁１３、Ｅ
ＧＲ弁２６、及び排気絞り弁２１が全開に制御される
と、内燃機関１の燃焼状態に影響を及ぼすことが想定さ
れるため、ＰＭ再生処理又はＳＯx被毒解消処理が実行
された直後の所定期間内であり、且つ、内燃機関１が減
速運転状態にある時のように内燃機関１に対する燃料噴
射が停止されている時に固着検出制御を実行することが
好ましい。However, even in the predetermined period immediately after the PM regeneration process or the SOx poisoning elimination process is executed, the internal combustion engine 1
In the case where fuel is being combusted in (for example, the internal combustion engine 1 is in an idle operation state, an acceleration operation state, or a steady operation state), the intake throttle valves 13, E are carelessly taken.
When the GR valve 26 and the exhaust throttle valve 21 are controlled to be fully opened, it is expected that the combustion state of the internal combustion engine 1 will be affected. Therefore, a predetermined period immediately after the PM regeneration process or the SOx poisoning elimination process is executed. It is preferable to execute the sticking detection control during the period and when the fuel injection to the internal combustion engine 1 is stopped, such as when the internal combustion engine 1 is in the deceleration operation state.
【０１１２】このように、ＰＭ再生処理又はＳＯx被毒
解消処理が実行された直後の所定期間であり且つ内燃機
関１が減速運転状態にある時に、吸気絞り弁１３、ＥＧ
Ｒ弁２６、及び排気絞り弁２１を全開に制御してバイパ
ス制御弁２９の固着検出制御が実行されるようにすれ
ば、内燃機関１の燃焼状態に影響を及ぼすことなく正確
な固着検出を行うことが可能となる。As described above, during the predetermined period immediately after the PM regeneration process or the SOx poisoning elimination process is executed and the internal combustion engine 1 is in the deceleration operation state, the intake throttle valve 13, EG
If the R valve 26 and the exhaust throttle valve 21 are controlled to be fully opened to execute the sticking detection control of the bypass control valve 29, accurate sticking detection is performed without affecting the combustion state of the internal combustion engine 1. It becomes possible.
【０１１３】また、内燃機関１の吸入空気量は機関回転
数と相関があるため、バイパス制御弁２９の固着を精度
良く検出する上では、全開時実吸入空気量及び全閉時実
吸入空気量が検出された際の機関回転数に対応した正常
時全開吸入空気量と正常時全閉吸入空気量とを求める必
要がある。Further, since the intake air amount of the internal combustion engine 1 correlates with the engine speed, in order to detect the sticking of the bypass control valve 29 with high accuracy, the actual intake air amount when fully opened and the actual intake air amount when fully closed. It is necessary to obtain the normal full-open intake air amount and the normal full-close intake air amount corresponding to the engine speed when is detected.
【０１１４】これに対し、吸気絞り弁１３、ＥＧＲ弁２
６、及び排気絞り弁２１の開度が全開位置にあるときの
正常全開時吸入空気量と機関回転数との関係、及び正常
全閉時吸入空気量と機関回転数との関係を予め実験的に
求めておき、それらの関係をマップ化してＲＯＭ３０２
に記憶しておくものとする。以下では、正常全開時吸入
空気量と機関回転数との関係を示すマップを正常全開時
基準マップと称し、正常全閉時吸入空気量と機関回転数
との関係を示すマップを正常全閉時基準マップと称す
る。On the other hand, the intake throttle valve 13 and the EGR valve 2
6 and the relationship between the normally open intake air amount and the engine speed and the relationship between the normally fully closed intake air amount and the engine speed when the opening of the exhaust throttle valve 21 is at the fully open position. In the ROM 302 by mapping those relationships.
Shall be stored in. Below, the map showing the relationship between the intake air amount at normal full opening and the engine speed is referred to as the normal fully open reference map, and the map showing the relationship between the intake air amount at normal fully closed and the engine speed is shown at normal fully closed. It is called a reference map.
【０１１５】次に、バイパス制御弁２９の固着及び固着
の態様が検出された後の制御について述べる。Next, the control after the fixation of the bypass control valve 29 and the mode of the fixation are detected will be described.
【０１１６】先ず、バイパス制御弁２９が全開位置で固
着している場合は、ＥＧＲガスがＥＧＲクーラ２７を流
れずにバイパス通路２８のみを流れることになるため、
ＥＧＲガスが冷却されなり、それに応じてＥＧＲガスの
体積が縮小されなくなる。First, when the bypass control valve 29 is fixed at the fully open position, the EGR gas does not flow through the EGR cooler 27 but flows only through the bypass passage 28.
The EGR gas is cooled, and the volume of the EGR gas is not reduced accordingly.
【０１１７】このようにＥＧＲガスが冷却されなくなる
とともにＥＧＲガスの体積が縮小されなくなると、内燃
機関１の各気筒２が圧縮行程上死点にあるときの筒内温
度（圧縮端温度）が上昇するとともに各気筒２に吸入さ
れる空気量が減少するため、各気筒２の燃焼過程におい
て煤が発生し易くなる。When the EGR gas is not cooled and the volume of the EGR gas is not reduced in this way, the in-cylinder temperature (compression end temperature) rises when each cylinder 2 of the internal combustion engine 1 is at the top dead center of the compression stroke. At the same time, since the amount of air taken into each cylinder 2 is reduced, soot is easily generated in the combustion process of each cylinder 2.
【０１１８】特に、ＥＧＲガス量を煤の発生量が最大と
なる量より更に増加させることにより、燃焼室内の燃焼
時における燃料及びその周囲のガス温度を煤の発生温度
より低くし、以て煤を殆ど発生させないようにする条件
下で内燃機関１が運転（低温燃焼運転）されている場合
には、圧縮端温度の上昇による燃焼温度の不要な上昇、
及びＥＧＲガスの体積増加による吸入空気量の過剰な減
少が誘発されるため、混合気の燃焼過程において煤が発
生し易くなる。Particularly, by further increasing the EGR gas amount beyond the amount at which the soot generation amount is maximum, the temperature of the fuel and the gas around it during combustion in the combustion chamber is made lower than the soot generation temperature, and the soot is generated. When the internal combustion engine 1 is operating (low temperature combustion operation) under the condition that causes almost no combustion, the combustion temperature unnecessarily rises due to the rise of the compression end temperature,
Also, since the intake air amount is excessively decreased by the increase in the volume of the EGR gas, soot is likely to be generated in the combustion process of the air-fuel mixture.
【０１１９】そこで、本実施の形態では、バイパス制御
弁２９の全開位置での固着が検出された場合には、ＣＰ
Ｕ３０１は、内燃機関１を通常燃焼運転させるととも
に、ＥＧＲガス量を減少させるべくＥＧＲ弁２６および
または吸気絞り弁１３の開度を制御するようにした。Therefore, in the present embodiment, when the bypass control valve 29 is detected to be stuck at the fully open position, the CP
U301 controls the opening degree of the EGR valve 26 and / or the intake throttle valve 13 so as to reduce the EGR gas amount while the internal combustion engine 1 is normally operated for combustion.
【０１２０】また、バイパス制御弁２９が全閉位置で固
着している場合は、ＥＧＲガスがバイパス通路２８を流
れずにＥＧＲクーラ２７のみを流れることになるため、
冷却されたＥＧＲガスが常に冷却されることになる。When the bypass control valve 29 is stuck in the fully closed position, the EGR gas does not flow in the bypass passage 28 but flows only in the EGR cooler 27.
The cooled EGR gas will always be cooled.
【０１２１】このように冷却されたＥＧＲガスが内燃機
関１の各気筒２に供給されると、各気筒２の圧縮端温度
が低下し易くなる。このため、内燃機関１が低温燃焼運
転されていると、圧縮端温度の低下により内燃機関の不
完全燃焼や失火が誘発される可能性がある。特に、内燃
機関１の温度と負荷と圧縮比との少なくとも一つが低い
状態で低温燃焼運転が行われている場合は、圧縮端温度
の低下が過剰に低下し、内燃機関１の不完全燃焼や失火
が誘発され易い。When the EGR gas cooled in this way is supplied to each cylinder 2 of the internal combustion engine 1, the compression end temperature of each cylinder 2 is easily lowered. Therefore, when the internal combustion engine 1 is in the low temperature combustion operation, the incomplete combustion or the misfire of the internal combustion engine may be induced due to the decrease in the compression end temperature. Particularly, when the low temperature combustion operation is performed in a state where at least one of the temperature, the load and the compression ratio of the internal combustion engine 1 is low, the decrease in the compression end temperature is excessively decreased, and the incomplete combustion of the internal combustion engine 1 or Misfires are easily induced.
【０１２２】そこで、本実施の形態では、バイパス制御
弁２９の全閉位置での固着が検出された場合には、ＣＰ
Ｕ３０１は、内燃機関１の温度と負荷と圧縮比との少な
くとも一つが低い状態で低温燃焼運転が行われる時に、
ＥＧＲガス量を減少させるべくＥＧＲ弁２６およびまた
は吸気絞り弁１３を制御するようにした。具体的には、
ＣＰＵ３０１は、水温が低い状態で内燃機関１が低温燃
焼運転される時、水温及び圧縮比が低い状態で内燃機関
１が低温燃焼運転される時、及び、負荷及び圧縮比が低
い状態で内燃機関１が低温燃焼運転される時に、ＥＧＲ
ガス量を減少させるべくＥＧＲ弁２６およびまたは吸気
絞り弁１３を制御する。Therefore, in this embodiment, when the bypass control valve 29 is detected to be stuck at the fully closed position, the CP
U301 is a low-temperature combustion operation when at least one of the temperature, load and compression ratio of the internal combustion engine 1 is low,
The EGR valve 26 and / or the intake throttle valve 13 are controlled to reduce the EGR gas amount. In particular,
The CPU 301 controls the internal combustion engine 1 when the internal combustion engine 1 is in low temperature combustion operation in a low water temperature state, when the internal combustion engine 1 is in low temperature combustion operation in a low water temperature and compression ratio state, and in a low load and compression ratio state. 1 is operated by low temperature combustion, EGR
The EGR valve 26 and / or the intake throttle valve 13 are controlled to reduce the gas amount.
【０１２３】また、バイパス制御弁２９が中開位置で固
着した場合には、ＥＧＲガスがバイパス通路２８とＥＧ
Ｒクーラ２７の双方を流れることになるため、内燃機関
１に吸入されるＥＧＲガス量が多くなり易い。Further, when the bypass control valve 29 is stuck in the middle open position, the EGR gas is discharged from the bypass passage 28 and the EG.
Since it flows through both R coolers 27, the amount of EGR gas drawn into the internal combustion engine 1 tends to increase.
【０１２４】このため、本実施の形態では、バイパス制
御弁２９の中開位置での固着が検出された場合には、Ｃ
ＰＵ３０１は、内燃機関１の運転状態に関わらずＥＧＲ
ガス量を減少させるべくＥＧＲ弁２６およびまたは吸気
絞り弁１３を制御するようにした。Therefore, in the present embodiment, when the fixation at the middle open position of the bypass control valve 29 is detected, C
The PU 301 controls the EGR regardless of the operating state of the internal combustion engine 1.
The EGR valve 26 and / or the intake throttle valve 13 are controlled to reduce the gas amount.
【０１２５】前述したように、バイパス制御弁２９の固
着が検出された場合にその固着の態様に応じて内燃機関
１の運転状態やＥＧＲガスの量を制御することにより、
内燃機関１の運転状態の悪化や排気エミッションの悪化
を抑制することができる。As described above, when sticking of the bypass control valve 29 is detected, the operating state of the internal combustion engine 1 and the amount of EGR gas are controlled according to the sticking mode.
It is possible to suppress deterioration of the operating state of the internal combustion engine 1 and deterioration of exhaust emission.
【０１２６】尚、バイパス制御弁２９の固着が検出され
た場合には、バイパス制御弁２９の固着を車両の運転者
へ通知してバイパス制御弁２９の修理を促すことも重要
である。これに対し、例えば、車両の室内に予め警告
灯、メッセージ表示装置、或いは警告ブザーなどを設け
ておき、バイパス制御弁２９の固着が検出された際にＣ
ＰＵ３０１が警告灯、メッセージ表示装置、或いは警告
ブザーを作動させるようにするとよい。When the sticking of the bypass control valve 29 is detected, it is important to notify the driver of the vehicle of the sticking of the bypass control valve 29 to prompt the repair of the bypass control valve 29. On the other hand, for example, a warning light, a message display device, a warning buzzer, or the like is provided in advance in the vehicle cabin, and when the sticking of the bypass control valve 29 is detected, C
The PU 301 may activate a warning light, a message display device, or a warning buzzer.
【０１２７】以下、本実施の形態に係る固着検出制御に
ついて図４に沿って説明する。図４は、本実施の形態に
おける固着検出制御ルーチンを示すフローチャート図で
ある。固着検出制御ルーチンは、予めＲＯＭ３０２に記
憶されているルーチンであり、ＣＰＵ３０１によって所
定時間毎（例えば、クランクポジションセンサ３３がパ
ルス信号を出力する度）に繰り返し実行されるルーチン
である。The sticking detection control according to this embodiment will be described below with reference to FIG. FIG. 4 is a flowchart showing a sticking detection control routine in the present embodiment. The sticking detection control routine is a routine stored in advance in the ROM 302, and is a routine that is repeatedly executed by the CPU 301 at every predetermined time (for example, every time the crank position sensor 33 outputs a pulse signal).
【０１２８】固着検出制御ルーチンでは、ＣＰＵ３０１
は、先ずＳ４０１においてＰＭ再生処理又はＳＯx被毒
解消処理の実行終了時であるか否かを判別する。In the sticking detection control routine, the CPU 301
First, in S401, it is determined whether or not the PM regeneration process or the SOx poisoning elimination process is completed.
【０１２９】前記Ｓ４０１においてＰＭ再生処理又はＳ
Ｏx被毒解消処理の実行終了時ではないと判定された場
合は、ＣＰＵ３０１は、本ルーチンの実行を一旦終了す
る。In step S401, PM reproduction processing or S
When it is determined that it is not the end of the execution of the Ox poisoning elimination process, the CPU 301 once ends the execution of this routine.
【０１３０】前記Ｓ４０１においてＰＭ再生処理又はＳ
Ｏx被毒解消処理の実行終了時であると判定された場合
は、ＣＰＵ３０１は、Ｓ４０２へ進み、カウンタ：Ｃを
起動させる。このカウンタ：Ｃは、ＰＭ再生処理又はＳ
Ｏx被毒解消処理の実行終了時からの経過時間を計測す
るカウンタである。In step S401, PM reproduction processing or S
When it is determined that the execution of the Ox poisoning elimination processing is completed, the CPU 301 proceeds to S402 and activates the counter C. This counter: C is PM reproduction processing or S
This is a counter that measures the elapsed time from the end of execution of the Ox poisoning elimination processing.
【０１３１】Ｓ４０３では、ＣＰＵ３０１は、ＲＡＭ３
０３から最新の機関回転数：Ne、燃料噴射量：Qinj、及
びアクセル開度センサ３１の出力信号値（アクセル開
度）：Accpを読み込む。In S403, the CPU 301 causes the RAM 3
From 03, the latest engine speed: Ne, fuel injection amount: Qinj, and output signal value (accelerator opening) of the accelerator opening sensor 31: Accp are read.
【０１３２】Ｓ４０４では、ＣＰＵ３０１は、前記Ｓ４
０３で読み込まれた機関回転数：Ne、燃料噴射量：Qin
j、及びアクセル開度：Accpをパラメータとして内燃機
関１が減速運転状態にあるか否かを判別する。具体的に
は、ＣＰＵ３０１は、機関回転数：Neが所定回転数以上
であり、燃料噴射量：Qinjが“０”であり、更にアクセ
ル開度：Accpが“０”であるという３つの条件が成立し
ているときは内燃機関１が減速運転状態にあると判定
し、前記した３つの条件のうち少なくとも一つの条件が
不成立であるときは内燃機関１が減速運転状態にないと
判定する。In S404, the CPU 301 executes the above S4.
Engine speed read in 03: Ne, fuel injection amount: Qin
j, and accelerator opening: Accp is used as a parameter to determine whether the internal combustion engine 1 is in the decelerating operation state. Specifically, the CPU 301 has three conditions that the engine speed: Ne is equal to or higher than a predetermined speed, the fuel injection amount: Qinj is “0”, and the accelerator opening degree: Accp is “0”. When it is established, it is determined that the internal combustion engine 1 is in the decelerating operation state, and when at least one of the above three conditions is not established, it is determined that the internal combustion engine 1 is not in the decelerating operation state.
【０１３３】前記Ｓ４０４において内燃機関１が減速運
転状態にないと判定された場合は、ＣＰＵ３０１は、前
述したＳ４０３以降の処理を再度実行する。When it is determined in S404 that the internal combustion engine 1 is not in the decelerating operation state, the CPU 301 re-executes the processing of S403 and thereafter.
【０１３４】一方、前記Ｓ４０４において内燃機関１が
減速運転状態にあると判定された場合は、ＣＰＵ３０１
は、Ｓ４０５へ進み、カウンタ：Ｃの計測時間：Ｃが所
定時間以下であるか否かを判別する。On the other hand, if it is determined in S404 that the internal combustion engine 1 is in the deceleration operation state, the CPU 301
Advances to S405, and it is determined whether the measurement time C of the counter C is less than or equal to a predetermined time.
【０１３５】前記Ｓ４０５においてカウンタ：Ｃの計測
時間：Ｃが所定時間より長いと判定された場合、すなわ
ちＰＭ再生処理又はＳＯx被毒解消処理の実行終了時か
らの経過時間が所定時間を超えている場合は、ＣＰＵ３
０１は、本ルーチンの実行を一旦終了する。When it is determined in S405 that the measurement time C of the counter C is longer than the predetermined time, that is, the elapsed time from the end of execution of the PM regeneration process or the SOx poisoning elimination process exceeds the predetermined time. In case of CPU3
01 temporarily ends the execution of this routine.
【０１３６】前記Ｓ４０５においてカウンタ：Ｃの計測
時間：Ｃが所定時間以下であると判定された場合、すな
わちＰＭ再生処理又はＳＯx被毒解消処理の実行終了時
からの経過時間が所定時間以内である場合は、ＣＰＵ３
０１は、Ｓ４０６へ進む。In S405, when it is determined that the measurement time of the counter C: C is less than or equal to the predetermined time, that is, the elapsed time from the end of execution of the PM regeneration process or the SOx poisoning elimination process is within the predetermined time. In case of CPU3
01 proceeds to S406.
【０１３７】Ｓ４０６では、ＣＰＵ３０１は、吸気絞り
弁１３、ＥＧＲ弁２６、及び排気絞り弁２１を全開とす
べく、吸気絞り用アクチュエータ１４、排気絞り用アク
チュエータ２２、及びＥＧＲ弁２６を制御する。In step S406, the CPU 301 controls the intake throttle actuator 14, the exhaust throttle actuator 22, and the EGR valve 26 so that the intake throttle valve 13, the EGR valve 26, and the exhaust throttle valve 21 are fully opened.
【０１３８】ＣＰＵ３０１は、Ｓ４０７においてバイパ
ス制御弁２９を全開に制御し、次いでＳ４０８において
バイパス制御弁２９が全開制御されているときのエアフ
ローメータ１１の出力信号値（全開時実吸入空気量）：
Gaopを入力する。The CPU 301 controls the bypass control valve 29 to be fully opened in S407, and then the output signal value of the air flow meter 11 when the bypass control valve 29 is fully opened in S408 (actual intake air amount at full opening):
Enter Gaop.
【０１３９】ＣＰＵ３０１は、Ｓ４０９においてバイパ
ス制御弁２９を全閉に制御し、次いでＳ４１０において
バイパス制御弁２９が全閉制御されているときのエアフ
ローメータ１１の出力信号値（全閉時実吸入空気量）：
Gaclを入力する。The CPU 301 controls the bypass control valve 29 to be fully closed in S409, and then outputs the output signal value of the air flow meter 11 when the bypass control valve 29 is fully closed in S410 (actual intake air amount when fully closed). ):
Enter Gacl.
【０１４０】尚、全開時実吸入空気量：Gaopの検出時期
と全閉時実吸入空気量：Gaclの検出時期とは順序が逆で
あってもよい。The actual intake air amount at full open: Gaop detection timing and the actual intake air amount at full close: Gacl detection timing may be reversed in order.
【０１４１】Ｓ４１１では、ＣＰＵ３０１は、前記Ｓ４
０３で読み込まれた機関回転数：Neをパラメータとして
ＲＯＭ３０２の正常全開時基準マップと正常全閉時基準
マップとへアクセスし、機関回転数：Neに対応した正常
時全開吸入空気量：Baseop及び正常時全閉吸入空気量：
Baseclを算出する。In S411, the CPU 301 executes the above S4.
The engine speed: Ne read in 03 is used as a parameter to access the reference map for normal full opening and the reference map for normal normal closing of the ROM 302, and the normal open intake air amount corresponding to the engine speed: Ne: Baseop and normal Fully closed intake air volume:
Calculate Basecl.
【０１４２】Ｓ４１２では、前記Ｓ４０８で入力された
全開時実吸入空気量：Gaopと、前記Ｓ４０１０で入力さ
れた全閉時実吸入空気量：Gaclと、前記Ｓ４１１で算出
された正常時全開吸入空気量：Baseopと、前記Ｓ４１１
で算出された正常時全閉吸入空気量：Baseclとを比較す
る。At S412, the actual intake air amount at full open: Gaop input at S408, the actual intake air amount at fully closed: Gacl input at S4010, and the normally open intake air at normal time calculated at S411. Amount: Baseop and the above S411
Normal closed air intake amount calculated in Step 1: Compare with Basecl.
【０１４３】Ｓ４１３では、前記Ｓ４１２において正常
判定条件が成立している否かを判別する。正常判定条件
としては、例えば、全開時実吸入空気量：Gaopと全閉時
実吸入空気量：Gaclとが異なり、全開時実吸入空気量：
Gaopが正常時全開吸入空気量：Baseopと略等しく、全閉
時実吸入空気量：Gaclが正常時全閉吸入空気量：Basecl
と略等しいという３つの条件を例示することができる。In step S413, it is determined whether or not the normality determination condition is satisfied in step S412. As the normality determination condition, for example, the actual intake air amount when fully opened: Gaop and the actual intake air amount when fully closed: Gacl are different, and the actual intake air amount at fully opened:
Full open intake air volume when Gaop is normal: Baseop is almost equal, Full intake air volume when fully closed: Gacl Full intake air volume when Gacl is normal: Basecl
It is possible to exemplify three conditions that are substantially equal to.
【０１４４】前記Ｓ４１３において正常判定条件が成立
していると判定された場合は、ＣＰＵ３０１は、本ルー
チンの実行を一旦終了する。When it is determined in S413 that the normality determination condition is satisfied, the CPU 301 once ends the execution of this routine.
【０１４５】一方、前記Ｓ４１３において正常判定条件
が不成立であると判定された場合は、ＣＰＵ３０１は、
Ｓ４１４へ進み、全開固着判定条件が成立しているか否
かを判別する。On the other hand, when it is determined in S413 that the normality determination condition is not satisfied, the CPU 301 determines that
The process proceeds to S414, and it is determined whether or not the fully open fixation determination condition is satisfied.
【０１４６】ここで、全開固着判定条件としては、以下
の条件を例示することができる。先ずバイパス通路２８
の圧力損失がＥＧＲクーラ２７の圧力損失に比して多い
場合の全開固着判定条件としては、全開時実吸入空気
量：Gaopと全閉時実吸入空気量：Gaclとが略等しく、全
開時実吸入空気量：Gaopと正常時全開吸入空気量：Base
opとが略等しく、全閉時実吸入空気量：Gaclが正常時全
閉吸入空気量：Baseclより多くなるという３つ条件を例
示することができる。Here, the following conditions can be exemplified as the conditions for determining the full-open fixation. First, bypass passage 28
When the pressure loss of is larger than the pressure loss of the EGR cooler 27, the condition for determining the full-open solidification is that the actual intake air amount at full open: Gaop and the actual intake air amount at full close: Gacl are substantially the same. Intake air volume: Gaop and normal open intake air volume: Base
It is possible to exemplify three conditions in which op is substantially equal to each other, and the fully closed actual intake air amount: Gacl is larger than the normal fully closed intake air amount: Basecl.
【０１４７】また、バイパス通路２８の圧力損失がＥＧ
Ｒクーラ２７の圧力損失に比して小さい場合の全開固着
判定条件としては、全開時実吸入空気量：Gaopと全閉時
実吸入空気量：Gaclとが略等しく、全開時実吸入空気
量：Gaopと正常時全開吸入空気量：Baseopとが略等し
く、全閉時実吸入空気量：Gaclが正常時全閉吸入空気
量：Baseclより少なくなるという３つの条件を例示する
ことができる。The pressure loss in the bypass passage 28 is EG
When the full-open stuck determination condition is smaller than the pressure loss of the R cooler 27, the actual intake air amount at full open: Gaop and the actual intake air amount at fully closed: Gacl are substantially equal, and the actual intake air amount at full open: It is possible to exemplify three conditions in which Gaop and the normal fully open intake air amount: Baseop are substantially equal, and the fully closed actual intake air amount: Gacl is smaller than the normal fully closed intake air amount: Basecl.
【０１４８】前記したＳ４１４において全開固着判定条
件が成立していると判定された場合は、ＣＰＵ３０１
は、Ｓ４１５へ進み、予め車室内に設けられている警告
灯を点灯させる。If it is determined in S414 that the fully open fixation determination condition is satisfied, the CPU 301
Advances to S415, and turns on a warning lamp previously provided in the vehicle compartment.
【０１４９】Ｓ４１６では、ＣＰＵ３０１は、内燃機関
１の運転状態を通常燃焼運転に固定する。すなわち、Ｃ
ＰＵ３０１は、内燃機関１の低温燃焼運転を禁止する。In S416, the CPU 301 fixes the operating state of the internal combustion engine 1 to the normal combustion operation. That is, C
The PU 301 prohibits the low temperature combustion operation of the internal combustion engine 1.
【０１５０】Ｓ４１７では、ＣＰＵ３０１は、ＥＧＲガ
ス量を減少させるべくＥＧＲ弁２６およびまたは吸気絞
り弁１３を制御する。In S417, the CPU 301 controls the EGR valve 26 and / or the intake throttle valve 13 to reduce the EGR gas amount.
【０１５１】このようなＳ４１５〜Ｓ４１７の処理が実
行されると、バイパス制御弁２９が全開固着した状態で
内燃機関１が低温燃焼運転されることがなくなるととも
に、内燃機関１が通常燃焼運転されているときのＥＧＲ
ガス量が減少されるため、圧縮端温度の上昇及び吸入空
気量の減少による煤の発生を抑制することが可能とな
る。更に、車室内に設けられた警告灯が点灯されること
により、車両の運転者がバイパス制御弁２９の固着を認
識することが可能となる。When the processes of S415 to S417 are executed, the internal combustion engine 1 does not operate at low temperature while the bypass control valve 29 is fully open and fixed, and the internal combustion engine 1 operates normally. EGR when you are
Since the amount of gas is reduced, it is possible to suppress the generation of soot due to the rise in the compression end temperature and the reduction in the intake air amount. Further, by turning on the warning light provided in the vehicle compartment, the driver of the vehicle can recognize that the bypass control valve 29 is fixed.
【０１５２】また、前述したＳ４１４において全開固着
判定条件が不成立であると判定された場合は、ＣＰＵ３
０１は、Ｓ４１８へ進み、全閉固着判定条件が成立して
いるか否かを判別する。If it is determined in step S414 that the fully open fixation determination condition is not satisfied, the CPU 3
In step 01, the process proceeds to S418, and it is determined whether or not the full-closed sticking determination condition is satisfied.
【０１５３】ここで、全閉固着判定条件としては、以下
の条件を例示することができる。先ずバイパス通路２８
の圧力損失がＥＧＲクーラ２７の圧力損失に比して多い
場合の全閉固着判定条件としては、全開時実吸入空気
量：Gaopと全閉時実吸入空気量：Gaclとが略等しく、全
閉時実吸入空気量：Gaclと正常時全閉吸入空気量：Base
clとが略等しく、全開時実吸入空気量：Gaopが正常時全
開吸入空気量：Baseopより少なくなるという３つ条件を
例示することができる。Here, the following conditions can be exemplified as the full-closed sticking determination condition. First, bypass passage 28
When the pressure loss of is larger than the pressure loss of the EGR cooler 27, the fully closed fixed determination condition is that the actual intake air amount at full open: Gaop and the actual intake air amount at fully closed: Gacl are substantially equal to each other. Actual intake air volume: Gacl and normally closed intake air volume: Base
It is possible to exemplify three conditions in which cl is substantially equal and the actual intake air amount at full opening: Gaop becomes smaller than the fully open intake air amount at normal time: Baseop.
【０１５４】また、バイパス通路２８の圧力損失がＥＧ
Ｒクーラ２７の圧力損失に比して小さい場合の全開固着
判定条件としては、全開時実吸入空気量：Gaopと全閉時
実吸入空気量：Gaclとが略等しく、全閉時実吸入空気
量：Gaclと正常時全閉吸入空気量：Baseclとが略等し
く、全開時実吸入空気量：Gaopが正常時全開吸入空気
量：Baseopより多くなるという３つ条件を例示すること
ができる。Also, the pressure loss in the bypass passage 28 is EG
When the full-open sticking determination condition is smaller than the pressure loss of the R cooler 27, the fully-open actual intake air amount: Gaop and the fully-closed actual intake air amount: Gacl are substantially equal, and the fully-closed actual intake air amount. It is possible to exemplify the following three conditions: Gacl and normal closed full intake air amount: Basecl are substantially equal, and full open actual intake air amount: Gaop is larger than normal full open intake air amount: Baseop.
【０１５５】前記Ｓ４１８において全閉固着判定条件が
成立していると判定された場合は、ＣＰＵ３０１は、Ｓ
４１９へ進み、車室内の警告灯を点灯させる。When it is determined in S418 that the fully closed fixation determination condition is satisfied, the CPU 301 executes the S
Proceeding to 419, the warning light in the vehicle compartment is turned on.
【０１５６】Ｓ４２０では、ＣＰＵ３０１は、全閉固着
対応処理を実行する。全閉固着対応処理では、ＣＰＵ３
０１は、図５に示すような全閉固着対応処理ルーチンを
実行することになる。この全閉固着対応処理ルーチン
は、前述した固着検出制御ルーチンのサブルーチンであ
り、予めＲＯＭ３０２に記憶されているものとする。In S420, the CPU 301 executes a fully closed sticking handling process. In the fully closed sticking correspondence process, the CPU 3
01 executes a fully closed sticking handling processing routine as shown in FIG. This fully closed sticking support processing routine is a subroutine of the sticking detection control routine described above, and is stored in the ROM 302 in advance.
【０１５７】全閉固着対応処理ルーチンでは、ＣＰＵ３
０１は、先ずＳ５０１において内燃機関１が低温燃焼運
転されているか否かを判別する。In the fully closed sticking correspondence processing routine, the CPU 3
First, in S501, it is determined whether or not the internal combustion engine 1 is in the low temperature combustion operation in S501.
【０１５８】前記Ｓ５０１において内燃機関１が低温燃
焼運転されていないと判定された場合は、バイパス制御
弁２９の全閉固着に対して特別な処理を実行する必要が
ないとみなし、本サブルーチンの実行を終了して前述し
た図４の固着検出制御ルーチンへ戻る。When it is determined in S501 that the internal combustion engine 1 is not in the low temperature combustion operation, it is considered that there is no need to execute a special process for the fully closed state of the bypass control valve 29, and this subroutine is executed. And the routine returns to the above-mentioned sticking detection control routine of FIG.
【０１５９】一方、前記Ｓ５０１において内燃機関１が
低温燃焼運転されていると判定された場合は、ＣＰＵ３
０１は、Ｓ５０２へ進み、内燃機関１の圧縮比が通常よ
り低いか否かを判別する。On the other hand, if it is determined in S501 that the internal combustion engine 1 is in the low temperature combustion operation, the CPU 3
In step 01, the process proceeds to step S502, and it is determined whether the compression ratio of the internal combustion engine 1 is lower than normal.
【０１６０】前記Ｓ５０２において内燃機関１の圧縮比
が通常より低いと判定された場合は、ＣＰＵ３０１は、
Ｓ５０３へ進み、内燃機関１の負荷が低いか否か、又は
水温センサ３４の出力信号値（水温）が所定温度：Ｔ未
満であるか否かを判別する。When it is determined in S502 that the compression ratio of the internal combustion engine 1 is lower than usual, the CPU 301
In step S503, it is determined whether the load on the internal combustion engine 1 is low or whether the output signal value (water temperature) of the water temperature sensor 34 is less than the predetermined temperature T.
【０１６１】前記Ｓ５０３において内燃機関１の負荷が
低い、又は水温センサ３４の出力信号値（水温）が所定
温度：Ｔ未満であると判定された場合は、ＣＰＵ３０１
は、Ｓ５０５へ進み、ＥＧＲガス量を減少させるべく吸
気絞り弁１３およびまたはＥＧＲ弁２６を制御する。Ｃ
ＰＵ３０１は、このＳ５０５の処理を実行し終えると、
本サブルーチンを終了して前述した図４の固着検出制御
ルーチンへ戻る。If it is determined in S503 that the load on the internal combustion engine 1 is low or the output signal value (water temperature) of the water temperature sensor 34 is less than the predetermined temperature: T, the CPU 301
Advances to S505 to control the intake throttle valve 13 and / or the EGR valve 26 to reduce the EGR gas amount. C
When the PU 301 finishes executing the processing of S505,
After this subroutine is completed, the process returns to the sticking detection control routine shown in FIG.
【０１６２】前記Ｓ５０３において内燃機関１の負荷が
低くなく、且つ水温センサ３４の出力信号値（水温）が
所定温度：Ｔ以上であると判定された場合は、ＣＰＵ３
０１は、バイパス制御弁２９の全閉固着に対して特別な
処理を実行する必要がないとみなし、本サブルーチンの
実行を終了して前述した図４の固着検出制御ルーチンへ
戻る。If it is determined in S503 that the load of the internal combustion engine 1 is not low and the output signal value (water temperature) of the water temperature sensor 34 is equal to or higher than the predetermined temperature: T, the CPU 3
01 determines that it is not necessary to execute a special process for the fully closed sticking of the bypass control valve 29, finishes the execution of this subroutine, and returns to the sticking detection control routine of FIG. 4 described above.
【０１６３】前記Ｓ５０２において内燃機関１の圧縮比
が通常より低くないと判定された場合は、ＣＰＵ３０１
は、Ｓ５０４へ進み、水温センサ３４の出力信号値（水
温）が所定温度：Ｔ未満であるか否かを判別する。If it is determined in S502 that the compression ratio of the internal combustion engine 1 is not lower than usual, the CPU 301
Advances to S504, and it is determined whether or not the output signal value (water temperature) of the water temperature sensor 34 is less than the predetermined temperature: T.
【０１６４】前記Ｓ５０４において水温センサ３４の出
力信号値（水温）が所定温度：Ｔ以上であると判定され
た場合は、ＣＰＵ３０１は、バイパス制御弁２９の全閉
固着に対して特別な処理を実行する必要がないとみな
し、本サブルーチンの実行を終了して前述した図４の固
着検出制御ルーチンへ戻る。When it is determined in S504 that the output signal value (water temperature) of the water temperature sensor 34 is equal to or higher than the predetermined temperature: T, the CPU 301 executes a special process for the fully closed fixation of the bypass control valve 29. Assuming that there is no need to do so, the execution of this subroutine is terminated and the routine returns to the above-mentioned sticking detection control routine of FIG.
【０１６５】前記Ｓ５０４において水温センサ３４の出
力信号値（水温）が所定温度：Ｔ以下であると判定され
た場合は、ＣＰＵ３０１は、Ｓ５０５へ進み、ＥＧＲガ
ス量を減少させるべく吸気絞り弁１３およびまたはＥＧ
Ｒ弁２６を制御する。ＣＰＵ３０１は、このＳ５０５の
処理を実行し終えると、本サブルーチンを終了して前述
した図４の固着検出制御ルーチンへ戻る。When it is determined in S504 that the output signal value (water temperature) of the water temperature sensor 34 is equal to or lower than the predetermined temperature: T, the CPU 301 proceeds to S505, where the intake throttle valve 13 and the intake throttle valve 13 are arranged to reduce the EGR gas amount. Or EG
The R valve 26 is controlled. When the CPU 301 finishes executing the processing of S505, the CPU 301 terminates this subroutine and returns to the above-described sticking detection control routine of FIG.
【０１６６】このように全閉固着対応処理ルーチンが実
行されると、水温が低い状態で内燃機関１が低温燃焼運
転される場合、水温及び圧縮比が低い状態で内燃機関１
が低温燃焼運転される場合、及び、負荷及び圧縮比が低
い状態で内燃機関１が低温燃焼運転される場合に、ＥＧ
Ｒクーラ２７によって冷却されたＥＧＲガスが内燃機関
１へ過剰に流入することがなくなるため、圧縮端温度が
過剰に低下することがなくなり、以て内燃機関１の運転
状態の悪化を抑制することができる。When the fully closed sticking handling processing routine is executed in this way, when the internal combustion engine 1 is operated in low temperature combustion at a low water temperature, the internal combustion engine 1 is operated at a low water temperature and a low compression ratio.
Is operated at low temperature, and when the internal combustion engine 1 is operated at low temperature under low load and compression ratio.
Since the EGR gas cooled by the R cooler 27 does not excessively flow into the internal combustion engine 1, the compression end temperature does not excessively decrease, thereby suppressing deterioration of the operating state of the internal combustion engine 1. it can.
【０１６７】ここで図４の固着検出制御ルーチンに戻
り、前述したＳ４１８において全閉固着判定条件が不成
立であると判定された場合は、ＣＰＵ３０１は、Ｓ４２
１へ進み、中開固着判定条件が成立しているか否かを判
別する。中開固着判定条件としては、全開時実吸入空気
量：Gaopと全閉時実吸入空気量：Gaclとが略等しく、全
開時実吸入空気量：Gaopと正常時全開吸入空気量：Base
opとが異なり、全閉時実吸入空気量：Gaclと正常時全閉
吸入空気量：Baseclとが異なるという３つの条件を例示
することができる。Here, returning to the sticking detection control routine of FIG. 4, if it is judged in S418 that the fully closed sticking determination condition is not satisfied, the CPU 301 causes the S301 to proceed to S42.
The process proceeds to 1 and it is determined whether or not the medium open fixation determination condition is satisfied. The conditions for determining the middle-open sticking are that the actual intake air amount at full open: Gaop and the actual intake air amount at fully closed: Gacl are substantially equal, and the actual intake air amount at full open: Gaop and the normal full-open intake air amount: Base.
It is possible to exemplify three conditions that are different from op and that the actual intake air amount at the time of fully closed: Gacl and the fully closed intake air amount at the time of normal: Basecl are different.
【０１６８】前記Ｓ４２１において中開固着判定条件が
不成立であると判定された場合は、ＣＰＵ３０１は、固
着判定制御の実行を中断し、本ルーチンの実行を終了す
る。If it is determined in S421 that the medium open sticking determination condition is not satisfied, the CPU 301 suspends the execution of the sticking determination control and ends the execution of this routine.
【０１６９】前記Ｓ４２１において中開固着判定条件が
成立していると判定された場合は、ＣＰＵ３０１は、Ｓ
４２２へ進み、車室内の警告灯を点灯させる。If it is determined in S421 that the medium open fixation determination condition is satisfied, the CPU 301 executes the S
Proceeding to 422, the warning light in the vehicle compartment is turned on.
【０１７０】Ｓ４２３では、ＣＰＵ３０１は、ＥＧＲガ
ス量を減量させるべくＥＧＲ弁２６およびまたは吸気絞
り弁１３を制御する。ＣＰＵ３０１は、このＳ４２３の
処理を実行し終えると、本ルーチンの実行を一旦終了す
る。At S423, the CPU 301 controls the EGR valve 26 and / or the intake throttle valve 13 to reduce the EGR gas amount. When the CPU 301 finishes executing the processing of S423, it temporarily terminates the execution of this routine.
【０１７１】このようにＣＰＵ３０１が固着検出制御ル
ーチンを実行することにより、本発明に係る固着検出手
段が実現されることになる。By the CPU 301 executing the sticking detection control routine in this way, the sticking detecting means according to the present invention is realized.
【０１７２】従って、本実施の形態によれば、ＥＧＲガ
スを冷却するＥＧＲクーラ２７と、ＥＧＲクーラ２７を
迂回するバイパス通路２８と、ＥＧＲクーラ２７とバイ
パス通路２８へ流入するＥＧＲガスの流量比を調整する
バイパス制御弁２９と、を備えたＥＧＲ機構において、
バイパス制御弁２９の固着及び固着の態様を検出するこ
とが可能となる。Therefore, according to the present embodiment, the EGR cooler 27 that cools the EGR gas, the bypass passage 28 that bypasses the EGR cooler 27, and the flow rate ratio of the EGR gas flowing into the EGR cooler 27 and the bypass passage 28 are set. In the EGR mechanism including the bypass control valve 29 for adjusting,
It becomes possible to detect the fixation of the bypass control valve 29 and the mode of the fixation.
【０１７３】更に、本実施の形態では、バイパス制御弁
２９の固着が検出された場合に、バイパス制御弁２９の
固着の態様に応じて内燃機関１の運転状態やＥＧＲガス
量が制御されることになるため、バイパス制御弁２９の
固着に起因した機関運転状態の悪化や排気エミッション
の悪化を抑制することも可能となる。Further, in the present embodiment, when sticking of the bypass control valve 29 is detected, the operating state of the internal combustion engine 1 and the EGR gas amount are controlled according to the sticking state of the bypass control valve 29. Therefore, it is possible to suppress the deterioration of the engine operating state and the deterioration of the exhaust emission due to the sticking of the bypass control valve 29.
【０１７４】＜実施の形態２＞次に、本発明に係る内燃
機関のＥＧＲ機構の第２の実施の形態について図６〜図
１０に基づいて説明する。ここでは、前述した第１の実
施の形態と異なる構成について説明し、同様の構成につ
いては説明を省略する。<Second Embodiment> Next, a second embodiment of the EGR mechanism of the internal combustion engine according to the present invention will be described with reference to FIGS. 6 to 10. Here, a configuration different from that of the first embodiment described above will be described, and description of similar configurations will be omitted.
【０１７５】本実施の形態と前述した第１の実施の形態
との差異は、前述した第１の実施の形態ではフィルタ２
００のＰＭ再生処理又はＳＯx被毒解消処理が実行され
た直後の減速運転時にバイパス制御弁２９の固着検出制
御を実行するのに対し、本実施の形態では内燃機関１の
減速運転時に排気がフィルタ２００を迂回して流れるよ
う制御してバイパス制御弁２９の固着検出制御を行う点
にある。The difference between this embodiment and the above-described first embodiment is that the filter 2 is used in the above-described first embodiment.
While the PM detection process of 00 or the SOx poisoning elimination process is executed immediately after the deceleration operation of the bypass control valve 29 is performed during the deceleration operation, the exhaust gas is filtered during the deceleration operation of the internal combustion engine 1 in the present embodiment. It is the point that the sticking detection control of the bypass control valve 29 is performed by controlling so as to bypass 200.
【０１７６】本実施の形態に係る排気浄化機構２０は、
図６〜図８に示すように、フィルタ２００が装填された
ケーシング２０２を備えている。このケーシング２０２
には、上流側排気管１８から分岐してフィルタ２００の
一側の面に臨む第１の排気通路２０３と、上流側排気管
１８から分岐してフィルタ２００の他側の面に臨む第２
の排気通路２０４とが形成されるとともに、前記フィル
タ２００の温度に対応した電気信号を出力するフィルタ
温度センサ２０５が取り付けられている。The exhaust purification mechanism 20 according to this embodiment is
As shown in FIGS. 6 to 8, a casing 202 having a filter 200 loaded therein is provided. This casing 202
A first exhaust passage 203 that branches from the upstream exhaust pipe 18 to face one surface of the filter 200, and a second exhaust passage 203 that branches from the upstream exhaust pipe 18 to face the other surface of the filter 200.
The exhaust passage 204 is formed, and a filter temperature sensor 205 that outputs an electric signal corresponding to the temperature of the filter 200 is attached.
【０１７７】続いて、排気浄化機構２０は、上流側排気
管１８から第１及び第２の排気通路２０３、２０４へ分
岐する部位から前記フィルタ２００を経由せずに下流側
排気管１９へ排気を導くフィルタバイパス通路２０６を
備えている。Subsequently, the exhaust gas purification mechanism 20 exhausts the exhaust gas to the downstream side exhaust pipe 19 without passing through the filter 200 from the portion where the upstream side exhaust pipe 18 branches into the first and second exhaust passages 203 and 204. A filter bypass passage 206 for guiding is provided.
【０１７８】第１の排気通路２０３と第２の排気通路２
０４とフィルタバイパス通路２０６との分岐点には、排
気流れ切換弁２０７が設けられている。この排気流れ切
換弁２０７は、負圧式アクチュエータやステッパモータ
等からなる排気切換用アクチュエータ２０８によって駆
動される弁体２０７ａを備え、第１の排気通路２０３を
選択してフィルタ２００の一側から他側へ向かう排気の
流れ（以下、順流と記す）と、第２の排気通路２０４を
選択してフィルタ２００の他側から一側へ向かう排気の
流れ（以下、逆流と記す）と、フィルタバイパス通路２
０６を選択してフィルタ２００を迂回する排気の流れ
（以下、バイパス流と記す）とを切り換え可能になって
いる。First exhaust passage 203 and second exhaust passage 2
An exhaust flow switching valve 207 is provided at a branch point between 04 and the filter bypass passage 206. The exhaust flow switching valve 207 includes a valve body 207a driven by an exhaust switching actuator 208 including a negative pressure type actuator or a stepper motor, and selects the first exhaust passage 203 to select one side of the filter 200 from the other side. Flow of exhaust gas (hereinafter referred to as forward flow), flow of exhaust gas from the other side of the filter 200 toward one side (hereinafter referred to as reverse flow), and the filter bypass passage 2
It is possible to switch the exhaust flow bypassing the filter 200 by selecting 06 (hereinafter referred to as a bypass flow).
【０１７９】尚、フィルタ２００を収容するケーシング
２０２は、図７に示すように、フィルタバイパス通路２
０６の真上に位置するよう配置され、ケーシング２０２
の両側に上流側排気管１８から分岐した第１の排気通路
２０３と第２の排気通路２０４が接続される形となって
いる。ケーシング２０２内のフィルタ２００は、排気の
流れ方向を長さ方向と仮定した場合に、長さ方向に直交
する幅方向の長さが長さ方向の長さより長くなるよう形
成されている。このような構成によれば、排気浄化機構
２０を車両へ搭載する際に必要となるスペースを小さく
することができる。As shown in FIG. 7, the casing 202 for accommodating the filter 200 has a filter bypass passage 2
The casing 202 is arranged so as to be located right above 06.
The first exhaust passage 203 and the second exhaust passage 204 branched from the upstream exhaust pipe 18 are connected to both sides of the above. The filter 200 in the casing 202 is formed such that the length in the width direction orthogonal to the length direction is longer than the length in the length direction, assuming that the exhaust flow direction is the length direction. With such a configuration, the space required for mounting the exhaust emission control mechanism 20 on the vehicle can be reduced.
【０１８０】前記したフィルタ２００は、例えば、一端
が閉塞され且つ他端が開放された排気通路と、一端が開
放され且つ他端が閉塞された排気通路とが隔壁を介して
交互に且つハニカム状に配置された、コージェライト等
のような多孔質の基材からなるウォールフロー型のフィ
ルタである。The filter 200 described above has, for example, an exhaust passage whose one end is closed and the other end is open, and an exhaust passage whose one end is open and the other end is closed, which are alternately and honeycomb-shaped. Is a wall-flow type filter made of a porous substrate such as cordierite.
【０１８１】前記した基材の隔壁の表面上及び隔壁の細
孔の内壁面には、アルミナ等からなる担体の層が形成さ
れており、この担体上に貴金属触媒と活性酸素放出剤と
が担持されている。On the surface of the partition wall of the base material and on the inner wall surface of the pores of the partition wall, a carrier layer made of alumina or the like is formed, and the noble metal catalyst and the active oxygen releasing agent are carried on this carrier. Has been done.
【０１８２】前記した貴金属触媒は、微粒子を酸化する
能力を有する物質であり、白金（Ｐｔ）等を例示するこ
とができる。The above-mentioned noble metal catalyst is a substance having an ability to oxidize fine particles, and platinum (Pt) and the like can be exemplified.
【０１８３】前記した活性酸素放出剤は、活性酸素を放
出して貴金属触媒による微粒子の酸化を促進するもので
あり、好ましくは、該活性酸素放出剤の周囲が酸素過剰
雰囲気のときは酸素を取り込んで保持するとともに、該
活性酸素放出剤の周囲の酸素濃度が低下したときは保持
していた酸素を活性酸素の形で放出するものである。こ
のような活性酸素放出剤としては、例えば、カリウム
（Ｋ）、ナトリウム（Ｎａ）、リチウム（Ｌｉ）、セシ
ウム（Ｃｓ）、ルビジウム（Ｒｂ）のようなアルカリ金
属、バリウム（Ｂａ）、カルシウム（Ｃａ）、ストロン
チウム（Ｓｒ）のようなアルカリ土類金属、ランタン
（Ｌａ）、イットリウム（Ｙ）のような希土類、および
遷移金属から選ばれた少なくとも一つから構成されるも
のを例示することができる。The above-mentioned active oxygen releasing agent releases active oxygen and promotes oxidation of fine particles by the noble metal catalyst. Preferably, when the surroundings of the active oxygen releasing agent are in an oxygen excess atmosphere, oxygen is taken in. The oxygen is retained in the form of active oxygen in the form of active oxygen when the oxygen concentration around the active oxygen releasing agent decreases. Examples of such an active oxygen releasing agent include alkali metals such as potassium (K), sodium (Na), lithium (Li), cesium (Cs) and rubidium (Rb), barium (Ba), calcium (Ca). ), An alkaline earth metal such as strontium (Sr), a rare earth such as lanthanum (La) and yttrium (Y), and a transition metal.
【０１８４】このように構成された排気浄化機構２０で
は、排気流れ切換弁２０７の弁体２０７ａが図６の破線
で示す位置（以下、順流位置と記す）にあるときは、上
流側排気管１８と第１の排気通路２０３とが導通すると
ともに、第２の排気通路２０４とフィルタバイパス通路
２０６とが導通することになるため、排気は上流側排気
管１８→第１の排気通路２０３→フィルタ２００→第２
の排気通路２０４→フィルタバイパス通路２０６→下流
側排気管１９の順に流れる。In the exhaust gas purification mechanism 20 having such a structure, when the valve body 207a of the exhaust flow switching valve 207 is at the position shown by the broken line in FIG. 6 (hereinafter referred to as the forward flow position), the upstream side exhaust pipe 18 And the first exhaust passage 203 are electrically connected to each other, and the second exhaust passage 204 and the filter bypass passage 206 are electrically connected to each other, so that the exhaust gas flows from the upstream exhaust pipe 18 to the first exhaust passage 203 to the filter 200. → second
Exhaust passage 204 → filter bypass passage 206 → downstream exhaust pipe 19 in that order.
【０１８５】排気浄化機構２０では、排気流れ切換弁２
０７の弁体２０７ａが図６の実線で示す位置（以下、逆
流位置と記す）にあるときは、上流側排気管１８と第２
の排気通路２０４とが導通するとともに、第１の排気通
路２０３とフィルタバイパス通路２０６とが導通するこ
とになるため、排気は、上流側排気管１８→第２の排気
通路２０４→フィルタ２００→第１の排気通路２０３→
フィルタバイパス通路２０６→下流側排気管１９の順に
流れる。In the exhaust purification mechanism 20, the exhaust flow switching valve 2
When the valve body 207a of No. 07 is at the position shown by the solid line in FIG. 6 (hereinafter, referred to as the backflow position), the upstream exhaust pipe 18 and the second exhaust pipe 18
Since the first exhaust passage 203 and the filter bypass passage 206 are electrically connected to each other while the exhaust passage 204 of the first exhaust passage 203 and the filter bypass passage 206 are electrically connected to each other, the exhaust gas is exhausted from the upstream side exhaust pipe 18 to the second exhaust passage 204 to the filter 200 to the second exhaust passage. 1 exhaust passage 203 →
It flows in the order of the filter bypass passage 206 and the downstream exhaust pipe 19.
【０１８６】排気浄化機構２０では、排気流れ切換弁２
０７の弁体２０７ａが図８に示すように上流側排気管１
８の軸線と平行となる中立位置にあるときは、上流側排
気管１８が直接フィルタバイパス通路２０６と導通する
ため、排気が上流側排気管１８からフィルタ２００を迂
回してフィルタバイパス通路２０６へ流れることにな
る。以下、弁体２０７ａの中立位置をバイパス流位置と
称する。In the exhaust purification mechanism 20, the exhaust flow switching valve 2
The valve body 207a of No. 07 has the exhaust pipe 1 on the upstream side as shown in FIG.
When in the neutral position which is parallel to the axis of 8, the upstream side exhaust pipe 18 directly communicates with the filter bypass passage 206, so that the exhaust gas bypasses the filter 200 from the upstream side exhaust pipe 18 and flows into the filter bypass passage 206. It will be. Hereinafter, the neutral position of the valve body 207a is referred to as the bypass flow position.
【０１８７】排気流れ切換弁２０７の弁体２０７ａの位
置が順流位置と逆流位置とに交互に切り換えられた場合
は、排気浄化機構２０における排気の流れが順流と逆流
とに交互に切り換えられることになり、煤などの微粒子
がフィルタ２００の基材内を活発に動き回ることになる
ため、微粒子の酸化が促進され、以て微粒子の浄化が効
率よく行われることになる。When the position of the valve body 207a of the exhaust flow switching valve 207 is switched to the forward flow position and the reverse flow position alternately, the exhaust flow in the exhaust purification mechanism 20 is switched to the forward flow and the reverse flow alternately. As a result, fine particles such as soot actively move around in the base material of the filter 200, so that the oxidation of the fine particles is promoted and the purification of the fine particles is efficiently performed.
【０１８８】すなわち、フィルタ２００に対し双方向か
ら排気が流れた場合には、微粒子は、フィルタ２００の
両面で順流方向と逆流方向に撹乱されるので、フィルタ
２００の両面で、あるいは、フィルタ２００の基材内部
で動き回ることになる。その結果、フィルタ２００の略
全域の活性点で微粒子が酸化されるようになるため、微
粒子の蓄積が抑制され、排気の圧損上昇を避けることが
できる。That is, when the exhaust gas flows in both directions to the filter 200, the fine particles are disturbed in the forward flow direction and the reverse flow direction on both sides of the filter 200, and therefore, on both sides of the filter 200 or in the filter 200. It will move around inside the substrate. As a result, since the fine particles are oxidized at the active points in almost the entire area of the filter 200, the accumulation of the fine particles is suppressed, and the increase in pressure loss of exhaust gas can be avoided.
【０１８９】次に、本実施の形態におけるＥＣＵ３０の
入力ポート３０６には、図９に示すように、クランクポ
ジションセンサ３３が直接接続されるとともに、コモン
レール圧センサ４ａ、エアフローメータ１１、吸気温度
センサ１２、酸素濃度センサ２３、排気温度センサ２
４、アクセル開度センサ３１、水温センサ３４、フィル
タ温度センサ２０５等のようにアナログ信号形式の信号
を出力するセンサの出力信号がＡ／Ｄ３０５を介して接
続されている。Next, as shown in FIG. 9, the crank position sensor 33 is directly connected to the input port 306 of the ECU 30 in the present embodiment, and the common rail pressure sensor 4a, the air flow meter 11, and the intake air temperature sensor 12 are connected. , Oxygen concentration sensor 23, exhaust temperature sensor 2
4, output signals of sensors such as the accelerator opening sensor 31, the water temperature sensor 34, and the filter temperature sensor 205 that output analog signal format signals are connected through the A / D 305.
【０１９０】出力ポート３０７には、燃料噴射弁３、吸
気絞り用アクチュエータ１４、排気絞り用アクチュエー
タ２２、ＥＧＲ弁２６、及びバイパス制御弁２９に加
え、排気切換用アクチュエータ２０８が接続されてい
る。An exhaust switching actuator 208 is connected to the output port 307 in addition to the fuel injection valve 3, the intake throttle actuator 14, the exhaust throttle actuator 22, the EGR valve 26, and the bypass control valve 29.
【０１９１】ＲＯＭ３０２は、燃料噴射弁３を制御する
ための燃料噴射制御ルーチン、吸気絞り弁１３を制御す
るための吸気絞り制御ルーチン、排気絞り弁２１を制御
するための排気絞り制御ルーチン、ＥＧＲ弁２６及びバ
イパス制御弁２９を制御するためのＥＧＲ制御ルーチ
ン、排気浄化機構２０の排気切換用アクチュエータ２０
８を制御するための排気浄化制御ルーチン等のアプリケ
ーションプログラムに加え、各種の制御マップを記憶し
ている。The ROM 302 includes a fuel injection control routine for controlling the fuel injection valve 3, an intake throttle control routine for controlling the intake throttle valve 13, an exhaust throttle control routine for controlling the exhaust throttle valve 21, an EGR valve. 26, an EGR control routine for controlling the bypass control valve 29, and the exhaust gas switching actuator 20 of the exhaust gas purification mechanism 20.
Various control maps are stored in addition to an application program such as an exhaust gas purification control routine for controlling No. 8.
【０１９２】前記ＣＰＵ３０１は、前記ＲＯＭ３０２に
記憶されたアプリケーションプログラムに従って動作
し、燃料噴射弁制御、吸気絞り制御、排気絞り制御、Ｅ
ＧＲ制御、及び排気浄化制御などの既知の制御に加え、
本発明の要旨となる固着検出制御を実行する。The CPU 301 operates in accordance with the application program stored in the ROM 302, and controls the fuel injection valve, the intake throttle control, the exhaust throttle control, and the E throttle control.
In addition to known controls such as GR control and exhaust purification control,
The sticking detection control which is the gist of the present invention is executed.
【０１９３】以下、本実施の形態における固着検出制御
について図１０に沿って説明する。図１０は、本実施の
形態における固着検出制御ルーチンを示すフローチャー
ト図である。固着検出制御ルーチンは、予めＲＯＭ３０
２に記憶されているルーチンであり、ＣＰＵ３０１によ
って所定時間毎（例えば、クランクポジションセンサ３
３がパルス信号を出力する度）に繰り返し実行されるル
ーチンである。The sticking detection control according to this embodiment will be described below with reference to FIG. FIG. 10 is a flowchart showing the sticking detection control routine in the present embodiment. The sticking detection control routine is executed in advance in the ROM 30.
2 is a routine stored in the CPU 2, and is executed by the CPU 301 at predetermined time intervals (for example, the crank position sensor 3
3 is a routine that is repeatedly executed each time a pulse signal is output.
【０１９４】固着検出制御ルーチンでは、ＣＰＵ３０１
は、先ずＳ１００１において、ＲＡＭ３０３から最新の
機関回転数：Ne、燃料噴射量：Qinj、及びアクセル開度
センサ３１の出力信号値（アクセル開度）：Accpを読み
込む。In the sticking detection control routine, the CPU 301
First, in step S1001, the latest engine speed: Ne, fuel injection amount: Qinj, and output signal value (accelerator opening) of the accelerator opening sensor 31: Accp are read from the RAM 303.
【０１９５】Ｓ１００２では、ＣＰＵ３０１は、前記Ｓ
１００１で読み込まれた機関回転数：Ne、燃料噴射量：
Qinj、及びアクセル開度：Accpをパラメータとして内燃
機関１が減速運転状態にあるか否かを判別する。具体的
には、ＣＰＵ３０１は、機関回転数：Neが所定回転数以
上であり、燃料噴射量：Qinjが“０”であり、更にアク
セル開度：Accpが“０”であるという３つの条件が成立
しているときは内燃機関１が減速運転状態にあると判定
し、前記した３つの条件のうち少なくとも一つの条件が
不成立であるときは内燃機関１が減速運転状態にないと
判定する。In S1002, the CPU 301 executes the above S
Engine speed read in 1001: Ne, fuel injection amount:
Qinj and accelerator opening: It is determined whether the internal combustion engine 1 is in the decelerating operation state using Accp as a parameter. Specifically, the CPU 301 has three conditions that the engine speed: Ne is equal to or higher than a predetermined speed, the fuel injection amount: Qinj is “0”, and the accelerator opening degree: Accp is “0”. When it is established, it is determined that the internal combustion engine 1 is in the decelerating operation state, and when at least one of the above three conditions is not established, it is determined that the internal combustion engine 1 is not in the decelerating operation state.
【０１９６】前記Ｓ１００２において内燃機関１が減速
運転状態にないと判定された場合は、ＣＰＵ３０１は、
本ルーチンの実行を一旦終了する。If it is determined in S1002 that the internal combustion engine 1 is not in the decelerating operation state, the CPU 301 determines that
The execution of this routine is once terminated.
【０１９７】一方、前記Ｓ１００２において内燃機関１
が減速運転状態にあると判定された場合は、ＣＰＵ３０
１は、Ｓ１００３へ進み、吸気絞り弁１３、ＥＧＲ弁２
６、及び排気絞り弁２１を全開に制御すると同時に、内
燃機関１の排気がフィルタ２００を迂回して流れるよう
に排気流れ切換弁２０７の開度をバイパス流位置に制御
する。On the other hand, in S1002, the internal combustion engine 1
Is determined to be in the deceleration operation state, the CPU 30
1 proceeds to S1003, the intake throttle valve 13, the EGR valve 2
6 and the exhaust throttle valve 21 are fully opened, and at the same time, the opening degree of the exhaust flow switching valve 207 is controlled to the bypass flow position so that the exhaust gas of the internal combustion engine 1 bypasses the filter 200.
【０１９８】ＣＰＵ３０１は、Ｓ１００４においてバイ
パス制御弁２９を全開に制御し、次いでＳ１００５にお
いてバイパス制御弁２９が全開制御されているときのエ
アフローメータ１１の出力信号値（全開時実吸入空気
量）：Gaopを入力する。The CPU 301 controls the bypass control valve 29 to be fully opened in S1004, and then the output signal value of the air flow meter 11 when the bypass control valve 29 is fully opened in S1005 (actual intake air amount at full opening): Gaop Enter.
【０１９９】ＣＰＵ３０１は、Ｓ１００６においてバイ
パス制御弁２９を全閉に制御し、次いでＳ１００７にお
いてバイパス制御弁２９が全閉制御されているときのエ
アフローメータ１１の出力信号値（全閉時実吸入空気
量）：Gaclを入力する。The CPU 301 controls the bypass control valve 29 to be fully closed in S1006, and then outputs the output signal value of the air flow meter 11 when the bypass control valve 29 is fully closed in S1007 (actual intake air amount when fully closed). ): Enter Gacl.
【０２００】尚、全開時実吸入空気量：Gaopの検出時期
と全閉時実吸入空気量：Gaclの検出時期とは順序が逆で
あってもよい。Note that the actual intake air amount when fully opened: Gaop detection timing and the actual intake air amount when fully closed: Gacl detection timing may be reversed.
【０２０１】Ｓ１００８では、ＣＰＵ３０１は、前記Ｓ
１００１で読み込まれた機関回転数：Neをパラメータと
してＲＯＭ３０２の正常全開時基準マップと正常全閉時
基準マップとへアクセスし、機関回転数：Neに対応した
正常時全開吸入空気量：Baseop及び正常時全閉吸入空気
量：Baseclを算出する。In S1008, the CPU 301 executes the above S
The engine speed: Ne read in 1001 is used as a parameter to access the normal fully open reference map and the normally fully closed reference map of the ROM 302, and the normally open intake air amount corresponding to the engine speed: Ne: Baseop and normal Calculate the fully closed intake air amount: Basecl.
【０２０２】Ｓ１００９では、前記Ｓ１００５で入力さ
れた全開時実吸入空気量：Gaopと、前記Ｓ１００７で入
力された全閉時実吸入空気量：Gaclと、前記Ｓ１００８
で算出された正常時全開吸入空気量：Baseopと、前記Ｓ
１００８で算出された正常時全閉吸入空気量：Baseclと
を比較する。In S1009, the actual intake air amount at full open: Gaop input in S1005, the actual intake air amount in fully closed: Gacl input in S1007, and S1008.
Fully open intake air amount in normal time calculated by: Baseop and S
The normal fully closed intake air amount calculated in 1008: Basecl is compared.
【０２０３】Ｓ１０１０では、前記Ｓ１００９において
正常判定条件が成立している否かを判別する。正常判定
条件としては、例えば、全開時実吸入空気量：Gaopと全
閉時実吸入空気量：Gaclとが異なり、全開時実吸入空気
量：Gaopが正常時全開吸入空気量：Baseopと略等しく、
全閉時実吸入空気量：Gaclが正常時全閉吸入空気量：Ba
seclと略等しいという３つの条件を例示することができ
る。In S1010, it is determined whether or not the normality determination condition is satisfied in S1009. As the normality determination condition, for example, the actual intake air amount at full open: Gaop and the actual intake air amount at fully closed: Gacl are different, and the actual intake air amount at full open: Gaop is almost equal to the fully open intake air amount at normal: Baseop. ,
Actual intake air amount when fully closed: Gacl Normal intake air amount when fully closed: Ba
Three conditions that are substantially equal to secl can be illustrated.
【０２０４】前記Ｓ１０１０において正常判定条件が成
立していると判定された場合は、ＣＰＵ３０１は、本ル
ーチンの実行を一旦終了する。If it is determined in S1010 that the normality determination condition is satisfied, the CPU 301 once terminates the execution of this routine.
【０２０５】一方、前記Ｓ１０１０において正常判定条
件が不成立であると判定された場合は、ＣＰＵ３０１
は、Ｓ１０１１へ進み、全開固着判定条件が成立してい
るか否かを判別する。On the other hand, if it is determined in S1010 that the normal condition is not satisfied, the CPU 301
Advances to S1011 and determines whether or not the fully open fixation determination condition is satisfied.
【０２０６】前記Ｓ１０１１において全開固着判定条件
が成立していると判定された場合は、ＣＰＵ３０１は、
Ｓ１０１２へ進み、予め車室内に設けられている警告灯
を点灯させる。If it is determined in S1011 that the fully open fixation determination condition is satisfied, the CPU 301 determines that
The process proceeds to S1012, and a warning lamp previously provided in the vehicle compartment is turned on.
【０２０７】Ｓ１０１３では、ＣＰＵ３０１は、内燃機
関１の運転状態を通常燃焼運転に固定する。すなわち、
ＣＰＵ３０１は、内燃機関１の低温燃焼運転を禁止す
る。[0207] In S1013, the CPU 301 fixes the operating state of the internal combustion engine 1 to the normal combustion operation. That is,
The CPU 301 prohibits the low temperature combustion operation of the internal combustion engine 1.
【０２０８】Ｓ１０１４では、ＣＰＵ３０１は、ＥＧＲ
ガス量を減少させるべくＥＧＲ弁２６およびまたは吸気
絞り弁１３を制御する。In step S1014, the CPU 301 determines that the EGR
The EGR valve 26 and / or the intake throttle valve 13 are controlled to reduce the gas amount.
【０２０９】このようなＳ１０１２〜Ｓ１０１４の処理
が実行されると、バイパス制御弁２９が全開固着した状
態で内燃機関１が低温燃焼運転されることがなくなると
ともに、内燃機関１が通常燃焼運転されているときのＥ
ＧＲガス量が減少されるため、圧縮端温度の上昇及び吸
入空気量の減少による煤の発生を抑制することが可能と
なる。更に、車室内に設けられた警告灯が点灯されるこ
とにより、車両の運転者がバイパス制御弁２９の固着を
認識することが可能となる。When the processes of S1012 to S1014 are executed, the internal combustion engine 1 is not operated at low temperature while the bypass control valve 29 is fully open and fixed, and the internal combustion engine 1 is operated normally. E when you are
Since the GR gas amount is reduced, it is possible to suppress the generation of soot due to the rise of the compression end temperature and the reduction of the intake air amount. Further, by turning on the warning light provided in the vehicle compartment, the driver of the vehicle can recognize that the bypass control valve 29 is fixed.
【０２１０】前述したＳ１０１１において全開固着判定
条件が不成立であると判定された場合は、ＣＰＵ３０１
は、Ｓ１０１５へ進み、全閉固着判定条件が成立してい
るか否かを判別する。If it is determined in S1011 described above that the fully open fixation determination condition is not satisfied, the CPU 301
Advances to S1015, and it is determined whether or not the fully closed fixation determination condition is satisfied.
【０２１１】前記Ｓ１０１５において全閉固着判定条件
が成立していると判定された場合は、ＣＰＵ３０１は、
Ｓ１０１６へ進み、車室内の警告灯を点灯させる。If it is determined in S1015 that the fully closed fixation determination condition is satisfied, the CPU 301 determines that
In step S1016, the warning light in the vehicle compartment is turned on.
【０２１２】Ｓ１０１７では、ＣＰＵ３０１は、全閉固
着対応処理を実行する。全閉固着対応処理では、ＣＰＵ
３０１は、前述した第１の実施の形態と同様の全閉固着
対応処理ルーチンを実行する。[0212] In S1017, the CPU 301 executes a fully closed sticking handling process. In the fully closed sticking correspondence process, the CPU
301 executes a fully closed sticking handling processing routine similar to that of the above-described first embodiment.
【０２１３】前述したＳ１０１５において全閉固着判定
条件が不成立であると判定された場合は、ＣＰＵ３０１
は、Ｓ１０１８へ進み、中開固着判定条件が成立してい
るか否かを判別する。If it is determined in S1015 described above that the fully closed fixation determination condition is not satisfied, the CPU 301
Advances to S1018, where it is determined whether or not the medium open fixation determination condition is satisfied.
【０２１４】前記Ｓ１０１８において中開固着判定条件
が不成立であると判定された場合は、ＣＰＵ３０１は、
固着判定制御の実行を中断し、本ルーチンの実行を終了
する。If it is determined in S1018 that the medium open fixation determination condition is not satisfied, the CPU 301 determines that
The execution of the sticking determination control is interrupted, and the execution of this routine ends.
【０２１５】また、前記Ｓ１０１８において中開固着判
定条件が成立していると判定された場合は、ＣＰＵ３０
１は、Ｓ１０１９へ進み、車室内の警告灯を点灯させ
る。If it is determined in S1018 that the medium open fixation determination condition is satisfied, the CPU 30
In step 1, the process proceeds to S1019, and the warning light in the vehicle compartment is turned on.
【０２１６】Ｓ１０２０では、ＣＰＵ３０１は、ＥＧＲ
ガス量を減量させるべくＥＧＲ弁２６およびまたは吸気
絞り弁１３を制御する。ＣＰＵ３０１は、このＳ１０２
０の処理を実行し終えると、本ルーチンの実行を一旦終
了する。At S1020, the CPU 301 causes the EGR
The EGR valve 26 and / or the intake throttle valve 13 are controlled to reduce the gas amount. The CPU 301 uses this S102
When the processing of 0 is completed, the execution of this routine is once terminated.
【０２１７】このようにＣＰＵ３０１が固着検出制御ル
ーチンを実行することにより、固着検出制御が実行され
る際に内燃機関１の排気がフィルタ２００を迂回して流
れることになるため、フィルタ２００の詰まり度合いに
起因した誤判定を防止しつつ、バイパス制御弁２９の固
着及び固着の態様を検出することが可能となる。When the CPU 301 executes the sticking detection control routine in this manner, the exhaust gas of the internal combustion engine 1 flows around the filter 200 when the sticking detection control is executed, so that the clogging degree of the filter 200 is increased. It is possible to detect the sticking and the form of sticking of the bypass control valve 29 while preventing an erroneous determination due to the above.
【０２１８】[0218]
【発明の効果】本発明によれば、ＥＧＲ通路を流れるＥ
ＧＲガスを冷却するＥＧＲクーラと、ＥＧＲクーラを迂
回するバイパス通路と、ＥＧＲクーラとバイパス通路と
へ流入するＥＧＲガスの流量比を調整するバイパス制御
弁とを備えた内燃機関のＥＧＲ機構において、バイパス
制御弁の固着を検出することが可能となる。According to the present invention, E flowing through the EGR passage
An EGR mechanism for an internal combustion engine including an EGR cooler that cools the GR gas, a bypass passage that bypasses the EGR cooler, and a bypass control valve that adjusts a flow rate ratio of the EGR gas flowing into the EGR cooler and the bypass passage are provided. It becomes possible to detect the sticking of the control valve.
【図１】 本発明を適用する内燃機関の概略構成を示す
図FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which the present invention is applied.
【図２】 第１の実施の形態における排気浄化機構の構
成を示す図FIG. 2 is a diagram showing a configuration of an exhaust gas purification mechanism according to the first embodiment.
【図３】 第１の実施の形態におけるＥＣＵの内部構成
を示すブロック図FIG. 3 is a block diagram showing an internal configuration of an ECU according to the first embodiment.
【図４】 第１の実施の形態における固着検出制御ルー
チンを示すフローチャート図FIG. 4 is a flowchart showing a sticking detection control routine according to the first embodiment.
【図５】 全閉固着対応処理ルーチンを示すフローチャ
ート図FIG. 5 is a flowchart showing a processing routine for a fully closed sticking.
【図６】 第２の実施の形態における排気浄化機構の構
成を示す図（１）FIG. 6 is a diagram (1) showing a configuration of an exhaust gas purification mechanism according to a second embodiment.
【図７】 第２の実施の形態における排気浄化機構の構
成を示す図（２）FIG. 7 is a diagram (2) showing a configuration of an exhaust gas purification mechanism according to a second embodiment.
【図８】 排気浄化機構の動作を説明する図FIG. 8 is a diagram for explaining the operation of the exhaust gas purification mechanism.
【図９】 第２の実施の形態におけるＥＣＵの内部構成
を示すブロック図FIG. 9 is a block diagram showing an internal configuration of an ECU according to the second embodiment.
【図１０】 第２の実施の形態における固着検出制御ル
ーチンを示すフローチャート図FIG. 10 is a flowchart showing a sticking detection control routine according to the second embodiment.
１・・・・内燃機関 １１・・・エアフローメータ １３・・・吸気絞り弁 ２０・・・排気浄化機構 ２１・・・排気絞り弁 ２５・・・ＥＧＲ通路 ２６・・・ＥＧＲ弁 ２７・・・ＥＧＲクーラ ２８・・・バイパス通路 ２９・・・バイパス制御弁 ３０・・・ＥＣＵ ２００・・フィルタ 1 ... Internal combustion engine 11 ... Air flow meter 13 ... Intake throttle valve 20 ... Exhaust gas purification mechanism 21 ... Exhaust throttle valve 25 ... EGR passage 26 ... EGR valve 27 ... EGR cooler 28: Bypass passage 29: Bypass control valve 30 ... ECU 200 ...
───────────────────────────────────────────────────── 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） Ｆ０２Ｍ 25/07 Ｆ０２Ｍ 25/07 ５７０Ｋ ５８０ ５８０Ｅ Ｆ０１Ｎ 3/02 ３０１ Ｆ０１Ｎ 3/02 ３０１Ｍ ３２１ ３２１Ａ Ｆ０２Ｄ 9/02 Ｆ０２Ｄ 9/02 Ｑ ３１５ ３１５Ｂ 21/08 ３０１ 21/08 ３０１Ａ 43/00 ３０１ 43/00 ３０１Ｋ ３０１Ｎ (72)発明者 林 孝太郎 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 曲田 尚史 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 石山 忍 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 柴田 大介 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 大羽 孝宏 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 根上 秋彦 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 小田 富久 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 Ｆターム(参考） 3G062 AA01 AA03 AA05 BA06 CA05 CA07 DA01 DA02 EA10 ED01 ED04 ED08 ED10 FA02 FA19 FA23 GA01 GA04 GA06 GA08 GA09 GA12 GA15 GA17 3G065 AA01 AA03 AA04 AA09 CA12 DA06 EA05 EA09 FA02 GA00 GA05 GA08 GA09 GA10 GA27 GA46 HA06 JA04 JA09 JA11 KA02 3G084 AA01 AA03 BA05 BA13 BA19 BA20 CA06 DA10 DA28 EA04 EA11 EB06 EB22 EC01 EC03 FA00 FA02 FA07 FA10 FA20 FA27 FA29 FA38 3G090 AA03 AA04 BA01 CB24 DA13 3G092 AA02 AA13 AA17 AA18 BB01 DC03 DC12 DD08 DG08 DG09 EA01 EA02 EB05 FA41 FB06 GA05 GA13 HA01Z HA04Z HB03Z HD01Z HD05Z HE03Z HE08Z HF08Z ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) F02M 25/07 F02M 25/07 570K 580 580E F01N 3/02 301 F01N 3/02 301M 321 321A F02D 9/02 F02D 9/02 Q 315 315B 21/08 301 21/08 301A 43/00 301 43/00 301K 301N (72) Inventor Kotaro Hayashi 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Corporation (72) Inventor Naofumi Umeda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Shinobu Ishiyama 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Daisuke Shibata Toyota City, Aichi Prefecture Town No. 1 Toyota Motor Corporation (72) Inventor Takahiro Ooba Aichi Toyota City, Toyota City 1 Toyota Motor Co., Ltd. (72) Inventor Akihiko Negami 1 Toyota City, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Tomihisa Oda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto In-car F-term (reference) 3G062 AA01 AA03 AA05 BA06 CA05 CA07 DA01 DA02 EA10 ED01 ED04 ED08 ED10 FA02 FA19 FA23 GA01 GA04 GA06 GA08 GA09 GA12 GA15 GA17 3G065 AA01 AA03 AA07 GA27 GA05 GA05 GA27 GA09 FA02 GA02 GA09 FA02 GA02 FA09 GA02 GA46 HA06 JA04 JA09 JA11 KA02 3G084 AA01 AA03 BA05 BA13 BA19 BA20 CA06 DA10 DA28 EA04 EA11 EB06 EB22 EC01 EC03 FA00 FA02 FA07 FA10 FA20 FA27 FA29 FA38 3G090 AA03 AA04 BA01 DG02 A01 A01 A01 A01 A01 A12 A18 A01 A18 A18 A12 A18 A12 A18 A12 A18 A12 A18 A12 A18 A12 A18 A12 A18 A12 A18 A18 A12 A18 A12 A18 A12 A18 A02 A18 A12 A18 A12 A01 FA41 FB06 GA05 GA13 HA01Z HA04Z HB03Z HD01Z HD05Z HE03Z HE08Z HF08Z
Claims (15)
部を還流させるＥＧＲ通路と、 前記ＥＧＲ通路を流れるＥＧＲガス量を調節するＥＧＲ
弁と、 前記ＥＧＲ通路に設けられ、該ＥＧＲ通路を流れるＥＧ
Ｒガスを冷却するＥＧＲクーラと、 前記ＥＧＲ通路において前記ＥＧＲクーラを迂回するバ
イパス通路と、 前記ＥＧＲクーラと前記バイパス通路とへ流入するＥＧ
Ｒガスの流量比を調整するバイパス制御弁と、 前記内燃機関の吸気系に設けられ、該吸気系を流れる空
気量を調整する吸気絞り弁と、 前記内燃機関の吸入空気量を検出する吸入空気量検出手
段と、 前記ＥＧＲ弁が全開であり且つ前記吸気絞り弁が全開で
あることを条件に、前記バイパス通路を全開及び全閉す
るよう前記バイパス制御弁を制御し、全開制御時及び全
閉制御時に前記吸入空気量検出手段が検出した吸入空気
量をパラメータとして前記バイパス制御弁の固着を検出
する固着検出手段と、を備えることを特徴とする内燃機
関のＥＧＲ機構。1. An EGR passage for returning a part of exhaust gas from an exhaust system of an internal combustion engine to an intake system, and an EGR passage for adjusting an EGR gas amount flowing through the EGR passage.
A valve and an EG that is provided in the EGR passage and flows through the EGR passage.
An EGR cooler that cools R gas, a bypass passage that bypasses the EGR cooler in the EGR passage, and an EG that flows into the EGR cooler and the bypass passage
Bypass control valve for adjusting the flow rate ratio of R gas, intake throttle valve provided in the intake system of the internal combustion engine for adjusting the amount of air flowing through the intake system, and intake air for detecting the intake air amount of the internal combustion engine The bypass control valve is controlled to fully open and fully close the bypass passage on condition that the amount detecting means, the EGR valve are fully open, and the intake throttle valve is fully open. An EGR mechanism for an internal combustion engine, comprising: a sticking detection unit that detects sticking of the bypass control valve using the intake air amount detected by the intake air amount detection unit as a parameter.
弁が全開制御されている時の吸入空気量と前記バイパス
制御弁が全閉制御されている時の吸入空気量とが略等し
い場合に、前記バイパス制御弁が固着していると判定す
ることを特徴とする請求項１に記載の内燃機関のＥＧＲ
機構。2. The sticking detection means, when the intake air amount when the bypass control valve is fully opened and the intake air amount when the bypass control valve is fully closed are substantially equal to each other, The EGR of the internal combustion engine according to claim 1, wherein it is determined that the bypass control valve is stuck.
mechanism.
が前記ＥＧＲクーラによる排気の圧力損失に比して大き
い場合は、前記固着検出手段は、全開制御時の吸入空気
量と全閉制御時の吸入空気量とが略等しく、全開制御時
の吸入空気量が正常時の吸入空気量と略等しく、更に全
閉制御時の吸入空気量が正常時の吸入空気量より多いこ
とを条件に、前記バイパス制御弁が全開位置で固着して
いると判定することを特徴とする請求項２に記載の内燃
機関のＥＧＲ機構。3. When the pressure loss of the exhaust gas due to the bypass passage is larger than the pressure loss of the exhaust gas due to the EGR cooler, the sticking detection means causes the intake air amount during the full open control and the intake air amount during the full close control. The bypass is provided under the condition that the intake air amount is substantially equal to the intake air amount during the full-open control and is substantially equal to the intake air amount under the normal condition, and the intake air amount during the full-close control is greater than the intake air amount during the normal operation. The EGR mechanism of the internal combustion engine according to claim 2, wherein it is determined that the control valve is stuck at the fully open position.
が前記ＥＧＲクーラによる排気の圧力損失に比して小さ
い場合は、前記固着検出手段は、全開制御時の吸入空気
量と全閉制御時の吸入空気量とが略等しく、全開制御時
の吸入空気量が正常時の吸入空気量と略等しく、更に全
閉制御時の吸入空気量が正常時の吸入空気量より少ない
ことを条件に、前記バイパス制御弁が全開位置で固着し
ていると判定することを特徴とする請求項２に記載の内
燃機関のＥＧＲ機構。4. When the pressure loss of the exhaust gas due to the bypass passage is smaller than the pressure loss of the exhaust gas due to the EGR cooler, the sticking detection means causes the intake air amount during the full open control and the intake air amount during the full close control. The bypass amount is substantially equal to the intake air amount, the intake air amount during the fully open control is approximately equal to the normal intake air amount, and the intake air amount during the fully closed control is less than the normal intake air amount. The EGR mechanism of the internal combustion engine according to claim 2, wherein it is determined that the control valve is stuck at the fully open position.
が前記ＥＧＲクーラによる排気の圧力損失に比して大き
い場合は、前記固着検出手段は、全開制御時の吸入空気
量と全閉制御時の吸入空気量とが略等しく、全開制御時
の吸入空気量が正常時の吸入空気量より少なく、更に全
閉制御時の吸入空気量が正常時の吸入空気量と略等しい
ことを条件に、前記バイパス制御弁が全閉位置で固着し
ていると判定することを特徴とする請求項２に記載の内
燃機関のＥＧＲ機構。5. When the pressure loss of the exhaust gas due to the bypass passage is larger than the pressure loss of the exhaust gas due to the EGR cooler, the sticking detection means causes the intake air amount during the full open control and the intake air amount during the full close control. The bypass amount is substantially equal to the air amount, the intake air amount in the fully open control is smaller than the normal intake air amount, and the intake air amount in the fully closed control is substantially equal to the normal intake air amount. The EGR mechanism of the internal combustion engine according to claim 2, wherein it is determined that the control valve is stuck at the fully closed position.
が前記ＥＧＲクーラによる排気の圧力損失に比して小さ
い場合は、前記固着検出手段は、全開制御時の吸入空気
量と全閉制御時の吸入空気量とが略等しく、全開制御時
の吸入空気量が正常時の吸入空気量より多く、更に全閉
制御時の吸入空気量が正常時の吸入空気量と略等しいこ
とを条件に、前記バイパス制御弁が全閉位置で固着して
いると判定することを特徴とする請求項２に記載の内燃
機関のＥＧＲ機構。6. When the pressure loss of the exhaust gas due to the bypass passage is smaller than the pressure loss of the exhaust gas due to the EGR cooler, the sticking detection means causes the intake air amount during the full opening control and the intake air amount during the full closing control. The bypass amount is substantially equal to the intake air amount, the intake air amount during the fully open control is larger than the normal intake air amount, and the intake air amount during the full close control is approximately equal to the normal intake air amount. The EGR mechanism of the internal combustion engine according to claim 2, wherein it is determined that the control valve is stuck at the fully closed position.
空気量と全閉制御時の吸入空気量とが略等しく、全開制
御時の吸入空気量が正常時の吸入空気量と等しくなく、
更に全閉制御時の吸入空気量が正常時の吸入空気量と等
しくないことを条件に、前記バイパス制御弁が中開位置
で固着していると判定することを特徴とする請求項２に
記載の内燃機関のＥＧＲ機構。7. The sticking detection means is configured such that the intake air amount during the fully open control is substantially equal to the intake air amount during the fully closed control, and the intake air amount during the fully open control is not equal to the normal intake air amount.
3. The bypass control valve is determined to be stuck in the middle open position on the condition that the intake air amount in the fully closed control is not equal to the normal intake air amount. EGR mechanism of internal combustion engine.
焼運転とを切換可能であり、 前記固着検出手段により前記バイパス制御弁が全開位置
で固着していると判定された場合に、前記内燃機関を通
常燃焼運転させるとともに前記ＥＧＲ通路を流れるＥＧ
Ｒガス量を減少させるＥＧＲガス減量手段を更に備える
ことを特徴とする請求項３又は請求項４に記載の内燃機
関のＥＧＲ機構。8. The internal combustion engine is capable of switching between a low temperature combustion operation and a normal combustion operation, and the internal combustion engine is operated when it is determined by the sticking detection means that the bypass control valve is stuck at the fully open position. EG flowing through the EGR passage while the engine is in normal combustion operation
The EGR mechanism for an internal combustion engine according to claim 3 or 4, further comprising an EGR gas reducing means for reducing the amount of R gas.
焼運転とを切換可能であり、 前記固着検出手段により前記バイパス制御弁が全閉位置
で固着していると判定された場合に、前記内燃機関が低
温燃焼運転されるときは前記ＥＧＲ通路を流れるＥＧＲ
ガス量を減少させるＥＧＲガス減量手段を更に備えるこ
とを特徴とする請求項５又は請求項６に記載の内燃機関
のＥＧＲ機構。9. The internal combustion engine is capable of switching between a low temperature combustion operation and a normal combustion operation, and when the bypass control valve determines that the bypass control valve is stuck at the fully closed position, When the internal combustion engine is operated at low temperature combustion, the EGR flowing through the EGR passage
The EGR mechanism for an internal combustion engine according to claim 5 or 6, further comprising an EGR gas reducing means for reducing the gas amount.
制御弁が中開位置で固着していると判定された場合に、
前記ＥＧＲ通路を流れるＥＧＲガス量を減量させるＥＧ
Ｒガス減量手段を更に備えることを特徴とする請求項７
に記載の内燃機関のＥＧＲ機構。10. When the by-adhesion detection means determines that the by-pass control valve is adhered at an intermediate open position,
EG for reducing the amount of EGR gas flowing through the EGR passage
The R gas reducing means is further provided.
An EGR mechanism of an internal combustion engine according to item 1.
気中の微粒子を捕集するパティキュレートフィルタと、 前記パティキュレートフィルタに捕集された微粒子を除
去して該パティキュレートフィルタの微粒子捕集能力を
再生させるフィルタ再生手段とを更に備え、 前記固着検出手段は、前記フィルタ再生手段により前記
パティキュレートフィルタの微粒子捕集能力が再生され
た後の所定期間内に前記バイパス制御弁の固着検出を行
うことを特徴とする請求項１に記載の内燃機関のＥＧＲ
機構。11. A particulate filter, which is provided in an exhaust system of the internal combustion engine and collects fine particles in exhaust gas, and fine particles collected by the particulate filter to remove fine particles of the particulate filter. Further comprising a filter regenerating means for regenerating the capacity, wherein the sticking detecting means detects sticking of the bypass control valve within a predetermined period after the particulate collecting capacity of the particulate filter is regenerated by the filter regenerating means. The EGR of the internal combustion engine according to claim 1, wherein
mechanism.
気中の微粒子を捕集するパティキュレートフィルタと、 前記内燃機関の排気が前記パティキュレートフィルタを
迂回して流れるよう排気の流れを制御する排気流れ制御
手段とを更に備え、 前記固着検出手段は、前記バイパス制御弁の固着検出を
行う際に、前記内燃機関の排気が前記パティキュレート
フィルタを迂回して流れるよう前記排気流れ制御手段を
制御することを特徴とする請求項１に記載の内燃機関の
ＥＧＲ機構。12. A particulate filter that is provided in an exhaust system of the internal combustion engine and collects particulates in the exhaust, and controls an exhaust flow so that the exhaust of the internal combustion engine bypasses the particulate filter. The exhaust flow control means is further provided, and the sticking detection means controls the exhaust flow control means so that the exhaust gas of the internal combustion engine bypasses the particulate filter when the sticking detection of the bypass control valve is performed. The EGR mechanism for an internal combustion engine according to claim 1, wherein:
パティキュレートフィルタに流入する排気の流れ方向を
逆転させ、或いは排気が該パティキュレートフィルタを
迂回するよう排気の流れを切り換える排気流れ切換手段
を具備し、 前記固着検出手段は、前記バイパス制御弁の固着検出を
行う際に、前記内燃機関の排気が前記パティキュレート
フィルタを迂回して流れるよう前記排気流れ切換手段を
制御することを特徴とする請求項１２に記載の内燃機関
のＥＧＲ機構。13. The particulate filter comprises exhaust flow switching means for reversing the flow direction of the exhaust gas flowing into the particulate filter or for switching the exhaust gas flow so that the exhaust gas bypasses the particulate filter, 13. The sticking detection means controls the exhaust flow switching means so that, when the sticking detection of the bypass control valve is carried out, the exhaust gas of the internal combustion engine bypasses the particulate filter and flows. An EGR mechanism of an internal combustion engine according to item 1.
排気系を流れる排気の流量を絞る排気絞り弁を更に備
え、 前記固着検出手段は、前記バイパス制御弁の固着検出を
行う際に、前記排気絞り弁を全開に制御することを特徴
とする請求項１に記載の内燃機関のＥＧＲ機構。14. The exhaust system of the internal combustion engine, further comprising an exhaust throttle valve for throttling the flow rate of exhaust gas flowing through the exhaust system, wherein the sticking detection means detects sticking of the bypass control valve. The EGR mechanism for an internal combustion engine according to claim 1, wherein the exhaust throttle valve is controlled to be fully opened.
減速運転時に前記吸気絞り弁及び前記ＥＧＲ弁を全開に
制御して前記バイパス制御弁の固着検出を行うことを特
徴とする請求項１〜請求項１４の何れか一に記載の内燃
機関のＥＧＲ機構。15. The sticking detection means detects the sticking of the bypass control valve by controlling the intake throttle valve and the EGR valve to be fully opened during deceleration operation of the internal combustion engine. The EGR mechanism of the internal combustion engine according to claim 14.
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|---|---|---|---|
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|---|---|---|---|
| JP2002043575A JP4122795B2 (en) | 2002-02-20 | 2002-02-20 | EGR mechanism of internal combustion engine |
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| Publication Number | Publication Date |
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