JP4941458B2 - Fault diagnosis device for internal combustion engine - Google Patents

Fault diagnosis device for internal combustion engine Download PDF

Info

Publication number
JP4941458B2
JP4941458B2 JP2008305006A JP2008305006A JP4941458B2 JP 4941458 B2 JP4941458 B2 JP 4941458B2 JP 2008305006 A JP2008305006 A JP 2008305006A JP 2008305006 A JP2008305006 A JP 2008305006A JP 4941458 B2 JP4941458 B2 JP 4941458B2
Authority
JP
Japan
Prior art keywords
exhaust
pressure egr
passage
amount
low
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2008305006A
Other languages
Japanese (ja)
Other versions
JP2010127243A (en
Inventor
崇志 松本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP2008305006A priority Critical patent/JP4941458B2/en
Publication of JP2010127243A publication Critical patent/JP2010127243A/en
Application granted granted Critical
Publication of JP4941458B2 publication Critical patent/JP4941458B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D41/221—Safety or indicating devices for abnormal conditions relating to the failure of actuators or electrically driven elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/0047—Controlling exhaust gas recirculation [EGR]
    • F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
    • F02D41/0055—Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
    • 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
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1448—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an exhaust gas pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Description

本発明は、内燃機関の故障診断装置に関する。   The present invention relates to an internal combustion engine failure diagnosis apparatus.

内燃機関の減速時に、排気絞り弁を全閉にすると共に低圧ＥＧＲ弁を全開にし、その時の新気の量の変化量から排気絞り弁の故障を診断する技術が開示されている（例えば、特許文献１参照）。しかしながら、特許文献１記載の技術では、排気絞り弁の故障を診断するだけであり、他の故障を診断できなかった。
特開２００８−１２８１１４号公報 特開２００１−２０７９１７号公報 特開２００４−０６０６０１号公報 A technique for diagnosing a failure of the exhaust throttle valve from the amount of change in the amount of fresh air at that time when the exhaust throttle valve is fully closed and the low pressure EGR valve is fully opened when the internal combustion engine is decelerating is disclosed (for example, patent Reference 1). However, the technique described in Patent Document 1 only diagnoses a failure of the exhaust throttle valve, and cannot diagnose other failures.
JP 2008-128114 A Japanese Patent Laid-Open No. 2001-207917 Japanese Patent Laid-Open No. 2004-060601

本発明は上記事情に鑑みてなされたものであり、その目的とするところは、内燃機関の故障診断装置において、排気絞り弁開故障と低圧ＥＧＲ弁閉故障とを同時に区別して診断する技術を提供することにある。   The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for simultaneously diagnosing an exhaust throttle valve opening failure and a low pressure EGR valve closing failure in an internal combustion engine failure diagnosis device. There is to do.

本発明にあっては、以下の構成を採用する。すなわち、本発明は、
内燃機関の排気通路に配置されたタービン及び前記内燃機関の吸気通路に配置されたコンプレッサを有するターボチャージャと、
前記タービンより下流の前記排気通路から排気の一部を低圧ＥＧＲガスとして取り込み、前記コンプレッサより上流の前記吸気通路へ当該低圧ＥＧＲガスを還流させる低圧ＥＧＲ通路と、
前記低圧ＥＧＲ通路に配置され、前記低圧ＥＧＲ通路内を流通する低圧ＥＧＲガスの量を調節する低圧ＥＧＲ弁と、
前記低圧ＥＧＲ通路との接続部位より下流の前記排気通路に配置され、前記排気通路内を流通する排気の量を調節する排気絞り弁と、
前記低圧ＥＧＲ通路との接続部位より上流の前記吸気通路に配置され、前記吸気通路内を流通する新気の量を検知する新気量検知手段と、
前記タービンより下流且つ前記排気絞り弁より上流の前記排気通路に配置され、前記排気通路内を流通する排気の圧力を検知する排気圧力検知手段と、
前記内燃機関の減速時に、前記排気絞り弁を可能な限り閉じると共に前記低圧ＥＧＲ弁を全開にし、前記新気量検知手段が検知する新気の量の変化量が所定量より少なく、且つ、前記排気圧力検知手段が検知する排気の圧力が所定圧力より小さい場合には、前記排気絞り弁が開いたまま閉じられない排気絞り弁開故障と診断し、前記新気量検知手段が検知する新気の量の変化量が所定量より少なく、且つ、前記排気圧力検知手段が検知する排気の圧力が所定圧力以上の場合には、前記低圧ＥＧＲ弁が閉じたまま開かない低圧ＥＧＲ弁閉故障と診断する故障診断手段と、
を備えることを特徴とする内燃機関の故障診断装置である。 In the present invention, the following configuration is adopted. That is, the present invention
A turbocharger having a turbine disposed in an exhaust passage of an internal combustion engine and a compressor disposed in an intake passage of the internal combustion engine;
A low pressure EGR passage that takes in a part of exhaust gas as low pressure EGR gas from the exhaust passage downstream from the turbine and recirculates the low pressure EGR gas to the intake passage upstream from the compressor;
A low-pressure EGR valve that is disposed in the low-pressure EGR passage and adjusts the amount of low-pressure EGR gas flowing through the low-pressure EGR passage;
An exhaust throttle valve that is disposed in the exhaust passage downstream of the connection portion with the low-pressure EGR passage and adjusts the amount of exhaust flowing through the exhaust passage;
A fresh air amount detecting means which is disposed in the intake passage upstream of the connection portion with the low pressure EGR passage and detects the amount of fresh air flowing through the intake passage;
An exhaust pressure detecting means that is disposed in the exhaust passage downstream from the turbine and upstream from the exhaust throttle valve, and detects the pressure of the exhaust gas flowing through the exhaust passage;
At the time of deceleration of the internal combustion engine, the exhaust throttle valve is closed as much as possible and the low pressure EGR valve is fully opened, and the amount of change in the amount of fresh air detected by the fresh air amount detecting means is less than a predetermined amount, and When the exhaust pressure detected by the exhaust pressure detecting means is smaller than a predetermined pressure, it is diagnosed that the exhaust throttle valve is not closed while the exhaust throttle valve is open, and the fresh air detected by the new air quantity detecting means is diagnosed. If the change amount of the exhaust gas is less than a predetermined amount and the exhaust pressure detected by the exhaust pressure detecting means is equal to or higher than the predetermined pressure, the low pressure EGR valve is diagnosed as being closed with the low pressure EGR valve closed. Fault diagnosis means to
A failure diagnosis apparatus for an internal combustion engine, comprising:

ここで、内燃機関の減速時に、排気絞り弁を可能な限り閉じると共に低圧ＥＧＲ弁を全開にしたときの、新気量検知手段が検知する新気の量の変化量の所定量とは、当該新気の量の変化量がその所定量よりも少ない場合に、排気絞り弁開故障又は低圧ＥＧＲ弁閉故障のどちらかが生じていると判断できる閾値であり、予め実験や検証等により求められている。また、内燃機関の減速時に、排気絞り弁を可能な限り閉じると共に低圧ＥＧＲ弁を全
開にしたときの、排気圧力検知手段が検知する排気の圧力の所定圧力とは、当該排気の圧力がその所定圧力より小さい場合に、排気絞り弁開故障が生じていると判断でき、当該排気の圧力がその所定圧力以上の場合に、低圧ＥＧＲ弁閉故障が生じていると判断できる閾値であり、予め実験や検証等により求められている。 Here, when the internal combustion engine is decelerated, when the exhaust throttle valve is closed as much as possible and the low pressure EGR valve is fully opened, the predetermined amount of the change amount of the fresh air detected by the fresh air amount detecting means is This is a threshold value that can be used to determine that either an exhaust throttle valve opening failure or a low pressure EGR valve closing failure has occurred when the amount of change in the amount of fresh air is less than the predetermined amount. ing. Further, when the internal combustion engine is decelerated, when the exhaust throttle valve is closed as much as possible and the low pressure EGR valve is fully opened, the predetermined pressure of the exhaust pressure detected by the exhaust pressure detecting means is the predetermined pressure of the exhaust gas. It is a threshold value that can be determined that an exhaust throttle valve opening failure has occurred when the pressure is smaller than the pressure, and that a low pressure EGR valve closing failure has occurred when the exhaust pressure is equal to or higher than the predetermined pressure. And is required by verification.

本発明によると、内燃機関の減速時に、排気絞り弁を可能な限り閉じると共に低圧ＥＧＲ弁を全開にすることにより、排気絞り弁開故障と低圧ＥＧＲ弁閉故障とを同時に区別して診断することができる。   According to the present invention, when the internal combustion engine is decelerated, the exhaust throttle valve is closed as much as possible and the low-pressure EGR valve is fully opened, so that the exhaust throttle valve opening failure and the low-pressure EGR valve closing failure can be distinguished and diagnosed simultaneously. it can.

本発明によると、内燃機関の故障診断装置において、排気絞り弁開故障と低圧ＥＧＲ弁閉故障とを同時に区別して診断することができる。   According to the present invention, in an internal combustion engine failure diagnosis apparatus, an exhaust throttle valve opening failure and a low pressure EGR valve closing failure can be distinguished and diagnosed simultaneously.

以下に本発明の具体的な実施例を説明する。   Specific examples of the present invention will be described below.

＜実施例１＞
図１は、本実施例に係る内燃機関の故障診断装置を適用する内燃機関、及びその吸気系・排気系の概略構成を示す図である。図１に示す内燃機関１は、ピストンと共に燃焼室を形成する気筒２を４つ有する水冷式の４ストロークサイクル・ディーゼルエンジンである。内燃機関１は、車両に搭載されている。各気筒２には、燃料タンクから燃料供給通路を介して燃料としての軽油が供給され、気筒２内へ軽油を適宜の量且つ適宜のタイミングで噴射する燃料噴射弁３が設けられている。内燃機関１には、吸気通路４及び排気通路５が接続されている。 <Example 1>
FIG. 1 is a diagram illustrating a schematic configuration of an internal combustion engine to which the failure diagnosis apparatus for an internal combustion engine according to the present embodiment is applied, and an intake system and an exhaust system thereof. An internal combustion engine 1 shown in FIG. 1 is a water-cooled four-stroke cycle diesel engine having four cylinders 2 that form a combustion chamber together with a piston. The internal combustion engine 1 is mounted on a vehicle. Each cylinder 2 is provided with a fuel injection valve 3 that is supplied with light oil from the fuel tank via a fuel supply passage and injects light oil into the cylinder 2 at an appropriate amount and at an appropriate timing. An intake passage 4 and an exhaust passage 5 are connected to the internal combustion engine 1.

内燃機関１に接続された吸気通路４の途中には、排気のエネルギを駆動源として作動するターボチャージャ６のコンプレッサ６ａが配置されている。コンプレッサ６ａよりも上流の吸気通路４には、該吸気通路４内を流通する新気の量に応じた信号を出力するエアフローメータ７が配置されている。エアフローメータ７により、内燃機関１に吸入される新気の量が測定される。本実施例におけるエアフローメータ７が本発明の新気量検知手段に相当する。なお、新気とは、吸気の内外気から内燃機関１に取り込まれる吸気である。   In the middle of the intake passage 4 connected to the internal combustion engine 1, a compressor 6a of a turbocharger 6 that operates using exhaust energy as a drive source is disposed. An air flow meter 7 that outputs a signal corresponding to the amount of fresh air that flows through the intake passage 4 is disposed in the intake passage 4 upstream of the compressor 6a. The amount of fresh air taken into the internal combustion engine 1 is measured by the air flow meter 7. The air flow meter 7 in this embodiment corresponds to the new air amount detection means of the present invention. The fresh air is intake air that is taken into the internal combustion engine 1 from the inside and outside air of the intake air.

コンプレッサ６ａよりも下流の吸気通路４には、吸気と外気とで熱交換を行うインタークーラ８が配置されている。インタークーラ８よりも下流の吸気通路４には、該吸気通路４内を流通する吸気の量を調節するスロットル弁９が配置されている。スロットル弁９は、電動アクチュエータにより開閉される。これら吸気通路４及びそれに配置された機器が内燃機関１に吸気を取り入れるための吸気系を構成している。   An intercooler 8 that performs heat exchange between the intake air and the outside air is disposed in the intake passage 4 downstream of the compressor 6a. A throttle valve 9 that adjusts the amount of intake air flowing through the intake passage 4 is disposed in the intake passage 4 downstream of the intercooler 8. The throttle valve 9 is opened and closed by an electric actuator. These intake passages 4 and the devices arranged in the intake passages 4 constitute an intake system for taking intake air into the internal combustion engine 1.

一方、内燃機関１に接続された排気通路５の途中には、ターボチャージャ６のタービン６ｂが配置されている。タービン６ｂよりも下流の排気通路５には、当該排気通路５を流通する排気の圧力に応じた信号を出力する排気圧力センサ１０が配置されている。排気圧力センサ１０により、タービン６ｂ下流且つ後述する排気絞り弁１２上流の排気の圧力が測定される。本実施例における排気圧力センサ１０が本発明の排気圧力検知手段に相当する。排気圧力センサ１０よりも下流の排気通路５には、排気中のＰＭ（微粒子物質）を捕集するＤＰＦ１１が配置されている。ＤＰＦ１１には、吸蔵還元型ＮＯｘ触媒が担持されている。ＤＰＦ１１は、いわゆるＮＯｘ還元制御、ＳＯｘ被毒回復制御、及びＰＭ酸化除去制御といったＤＰＦ１１の性能を回復させる制御の際に軽油が供給される場合がある。ＤＰＦ１１よりも下流の排気通路５には、該排気通路５内を流通する排気の量を調節する排気絞り弁１２が配置されている。排気絞り弁１２は、電動アクチュエータにより開閉される。これら排気通路５及びそれに配置された機器が内燃機関１から排気を排出させるた
めの排気系を構成している。 On the other hand, a turbine 6 b of the turbocharger 6 is arranged in the middle of the exhaust passage 5 connected to the internal combustion engine 1. An exhaust pressure sensor 10 that outputs a signal corresponding to the pressure of the exhaust gas flowing through the exhaust passage 5 is disposed in the exhaust passage 5 downstream of the turbine 6b. The exhaust pressure sensor 10 measures the pressure of the exhaust downstream of the turbine 6b and upstream of the exhaust throttle valve 12 described later. The exhaust pressure sensor 10 in this embodiment corresponds to the exhaust pressure detection means of the present invention. A DPF 11 that collects PM (particulate matter) in the exhaust is disposed in the exhaust passage 5 downstream of the exhaust pressure sensor 10. The DPF 11 carries an NOx storage reduction catalyst. The DPF 11 may be supplied with light oil during control for recovering the performance of the DPF 11 such as so-called NOx reduction control, SOx poisoning recovery control, and PM oxidation removal control. An exhaust throttle valve 12 that adjusts the amount of exhaust gas flowing through the exhaust passage 5 is disposed in the exhaust passage 5 downstream of the DPF 11. The exhaust throttle valve 12 is opened and closed by an electric actuator. The exhaust passage 5 and the devices arranged in the exhaust passage 5 constitute an exhaust system for exhausting exhaust gas from the internal combustion engine 1.

そして、内燃機関１には、排気通路５内を流通する排気の一部を低圧で吸気通路４へ還流（再循環）させる低圧ＥＧＲ装置３０が備えられている。本実施例では、低圧ＥＧＲ装置３０によって還流される排気を低圧ＥＧＲガスと称している。低圧ＥＧＲ装置３０は、低圧ＥＧＲガスが流通する低圧ＥＧＲ通路３１と、低圧ＥＧＲ通路３１を流通する低圧ＥＧＲガスの量を調節する低圧ＥＧＲ弁３２と、を有する。   The internal combustion engine 1 is provided with a low pressure EGR device 30 that recirculates (recirculates) part of the exhaust gas flowing through the exhaust passage 5 to the intake passage 4 at a low pressure. In this embodiment, the exhaust gas recirculated by the low pressure EGR device 30 is referred to as low pressure EGR gas. The low pressure EGR device 30 includes a low pressure EGR passage 31 through which the low pressure EGR gas flows, and a low pressure EGR valve 32 that adjusts the amount of the low pressure EGR gas through the low pressure EGR passage 31.

低圧ＥＧＲ通路３１は、ＤＰＦ１１よりも下流且つ排気絞り弁１２よりも上流の排気通路５と、コンプレッサ６ａよりも上流且つエアフローメータ７よりも下流の吸気通路４とを接続している。低圧ＥＧＲ通路３１を通って、排気が低圧ＥＧＲガスとして低圧で内燃機関１へ送り込まれる。   The low-pressure EGR passage 31 connects the exhaust passage 5 downstream of the DPF 11 and upstream of the exhaust throttle valve 12 and the intake passage 4 upstream of the compressor 6 a and downstream of the air flow meter 7. Exhaust gas is sent to the internal combustion engine 1 at low pressure as low pressure EGR gas through the low pressure EGR passage 31.

低圧ＥＧＲ弁３２は、低圧ＥＧＲ通路３１に配置され、低圧ＥＧＲ通路３１の通路断面積を調整することにより、該低圧ＥＧＲ通路３１を流通する低圧ＥＧＲガスの量を調節する。低圧ＥＧＲ弁３２は、電動アクチュエータにより開閉される。   The low pressure EGR valve 32 is disposed in the low pressure EGR passage 31 and adjusts the amount of the low pressure EGR gas flowing through the low pressure EGR passage 31 by adjusting the passage sectional area of the low pressure EGR passage 31. The low pressure EGR valve 32 is opened and closed by an electric actuator.

以上述べ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であるＥＣＵ１３が併設されている。ＥＣＵ１３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ユニットである。   The internal combustion engine 1 configured as described above is provided with an ECU 13 that is an electronic control unit for controlling the internal combustion engine 1. The ECU 13 is a unit that controls the operation state of the internal combustion engine 1 in accordance with the operation conditions of the internal combustion engine 1 and the request of the driver.

ＥＣＵ１３には、エアフローメータ７、排気圧力センサ１０、機関回転数を検出するクランクポジションセンサ１４、及び機関負荷を算出するアクセルポジションセンサ１５が電気配線を介して接続され、これら各種センサの出力信号がＥＣＵ１３に入力されるようになっている。   The ECU 13 is connected to an air flow meter 7, an exhaust pressure sensor 10, a crank position sensor 14 for detecting the engine speed, and an accelerator position sensor 15 for calculating the engine load via electric wiring. Output signals of these various sensors are output from the ECU 13. It is input to the ECU 13.

一方、ＥＣＵ１３には、燃料噴射弁３、並びに、スロットル弁９、排気絞り弁１２及び低圧ＥＧＲ弁３２のアクチュエータが電気配線を介して接続されており、該ＥＣＵ１３によりこれらの機器が制御される。   On the other hand, the fuel injection valve 3 and the actuators of the throttle valve 9, the exhaust throttle valve 12, and the low pressure EGR valve 32 are connected to the ECU 13 through electric wiring, and these devices are controlled by the ECU 13.

そして、本実施例では、内燃機関１の運転状態に応じて低圧ＥＧＲ弁３２を用い低圧ＥＧＲ通路３１を流通する低圧ＥＧＲガスの量を調節する。これにより、内燃機関１に吸入される吸気に低圧ＥＧＲガスを含んだ状態で内燃機関１を運転させる、いわゆるＥＧＲ運転を行い、吸気の酸素濃度を低下させて燃焼温度、燃焼速度を低下させて、燃焼時に発生するＮＯｘを低減させる効果を発揮させている。   In this embodiment, the amount of low-pressure EGR gas flowing through the low-pressure EGR passage 31 is adjusted using the low-pressure EGR valve 32 according to the operating state of the internal combustion engine 1. As a result, the internal combustion engine 1 is operated in a state where the intake air sucked into the internal combustion engine 1 contains low-pressure EGR gas, so-called EGR operation is performed, the oxygen concentration of the intake air is decreased, and the combustion temperature and the combustion speed are decreased. The effect of reducing NOx generated during combustion is exhibited.

ところで、排気絞り弁１２や低圧ＥＧＲ弁３２には、開いたまま閉じられない開故障や閉じたまま開かない閉故障等の故障が生じる場合がある。特に、排気絞り弁１２では、排気を通常排出せるため開弁状態であることが多く、開故障が生じるおそれが高い。また、低圧ＥＧＲ弁３２では、低圧ＥＧＲガスの流通が制限されるため閉弁状態であることが多く、閉故障が生じるおそれが高い。排気絞り弁１２や低圧ＥＧＲ弁３２の故障は、排気への悪影響が大きいので、これらの故障を見つけ出すことが必要となっている。   Incidentally, the exhaust throttle valve 12 and the low-pressure EGR valve 32 may have a failure such as an open failure that cannot be closed while it is open or a close failure that does not open when it is closed. In particular, the exhaust throttle valve 12 is often in an open state because exhaust can be discharged normally, and there is a high possibility that an open failure will occur. Further, the low pressure EGR valve 32 is often in a closed state because the flow of the low pressure EGR gas is restricted, and there is a high possibility that a close failure will occur. Failures of the exhaust throttle valve 12 and the low-pressure EGR valve 32 have a great adverse effect on the exhaust, so it is necessary to find these failures.

そこで、本実施例では、排気絞り弁１２の開故障と、低圧ＥＧＲ弁３２の閉故障とを、同時に区別して診断するようにした。具体的には、内燃機関１の減速時に、排気絞り弁１２を可能な限り閉じると共に低圧ＥＧＲ弁３２を全開にする。そして、このとき、エアフローメータ７が検知する新気の量の変化量が所定量Ｃｇより少なく、且つ、排気圧力センサ１０が検知する排気の圧力が所定圧力Ｃｐより小さい場合には、排気絞り弁１２の開故障と診断する。また、エアフローメータ７が検知する新気の量の変化量が所定量Ｃｇより少なく、且つ、排気圧力センサ１０が検知する排気の圧力が所定圧力Ｃｐ以上の場合には
、低圧ＥＧＲ弁３２の閉故障と診断する。 Therefore, in this embodiment, an open failure of the exhaust throttle valve 12 and a close failure of the low pressure EGR valve 32 are distinguished and diagnosed at the same time. Specifically, when the internal combustion engine 1 is decelerated, the exhaust throttle valve 12 is closed as much as possible and the low-pressure EGR valve 32 is fully opened. At this time, if the amount of change in the amount of fresh air detected by the air flow meter 7 is less than the predetermined amount Cg and the exhaust pressure detected by the exhaust pressure sensor 10 is smaller than the predetermined pressure Cp, the exhaust throttle valve Diagnose 12 open faults. Further, when the amount of change in the amount of fresh air detected by the air flow meter 7 is smaller than the predetermined amount Cg and the exhaust pressure detected by the exhaust pressure sensor 10 is equal to or higher than the predetermined pressure Cp, the low-pressure EGR valve 32 is closed. Diagnose a failure.

内燃機関１の減速時に上記診断を行うこととしたのは、内燃機関１の減速時は排気絞り弁１２や低圧ＥＧＲ弁３２を強制的に制御しても、内燃機関１の運転状態に悪影響を及ぼさないからである。   The reason why the diagnosis is performed when the internal combustion engine 1 is decelerated is that even if the exhaust throttle valve 12 and the low pressure EGR valve 32 are forcibly controlled during the deceleration of the internal combustion engine 1, the operating state of the internal combustion engine 1 is adversely affected. It is because it does not reach.

ここで、内燃機関１の減速時に、排気絞り弁１２を可能な限り閉じると共に低圧ＥＧＲ弁３２を全開にしたときの、エアフローメータ７が検知する新気の量の変化量の所定量Ｃｇとは、当該新気の量の変化量がその所定量Ｃｇよりも少ない場合に、排気絞り弁１２の開故障又は低圧ＥＧＲ弁３２の閉故障のどちらかが生じていると判断できる閾値であり、予め実験や検証等により求められている。また、内燃機関１の減速時に、排気絞り弁１２を可能な限り閉じると共に低圧ＥＧＲ弁３２を全開にしたときの、排気圧力センサが検知する排気の圧力の所定圧力Ｃｐとは、当該排気の圧力がその所定圧力Ｃｐより小さい場合に、排気絞り弁１２の開故障が生じていると判断でき、当該排気の圧力がその所定圧力以上の場合に、低圧ＥＧＲ弁３２の閉故障が生じていると判断できる閾値であり、予め実験や検証等により求められている。   Here, when the internal combustion engine 1 is decelerated, the predetermined amount Cg of the amount of change in the amount of fresh air detected by the air flow meter 7 when the exhaust throttle valve 12 is closed as much as possible and the low-pressure EGR valve 32 is fully opened. , Which is a threshold value for determining that either an open failure of the exhaust throttle valve 12 or a close failure of the low pressure EGR valve 32 has occurred when the amount of change in the amount of fresh air is less than the predetermined amount Cg. It is required by experiment and verification. Further, when the internal combustion engine 1 is decelerated, when the exhaust throttle valve 12 is closed as much as possible and the low pressure EGR valve 32 is fully opened, the predetermined pressure Cp of the exhaust pressure detected by the exhaust pressure sensor is the pressure of the exhaust Is smaller than the predetermined pressure Cp, it can be determined that an open failure of the exhaust throttle valve 12 has occurred, and when the exhaust pressure is higher than the predetermined pressure, a closed failure of the low pressure EGR valve 32 has occurred. This is a threshold value that can be determined, and is obtained in advance through experiments, verification, and the like.

本実施例によると、内燃機関１の減速時に、排気絞り弁１２を可能な限り閉じると共に低圧ＥＧＲ弁３２を全開にすることにより、排気絞り弁１２の開故障と低圧ＥＧＲ弁３２の閉故障とを同時に区別して診断することができる。   According to the present embodiment, when the internal combustion engine 1 is decelerated, the exhaust throttle valve 12 is closed as much as possible and the low-pressure EGR valve 32 is fully opened, so that the exhaust throttle valve 12 is open and the low-pressure EGR valve 32 is closed. Can be distinguished and diagnosed simultaneously.

次に、本実施例による排気絞り弁１２の開故障と低圧ＥＧＲ弁３２の閉故障とを同時に区別して診断する故障診断ルーチンについて説明する。図２は、本実施例による故障診断ルーチンを示したフローチャートである。本ルーチンは、所定の時間毎に繰り返し実行される。本ルーチンを実行するＥＣＵ１３が本発明の故障診断手段に相当する。   Next, a failure diagnosis routine for distinguishing and diagnosing an open failure of the exhaust throttle valve 12 and a close failure of the low pressure EGR valve 32 according to the present embodiment will be described. FIG. 2 is a flowchart showing a failure diagnosis routine according to this embodiment. This routine is repeatedly executed every predetermined time. The ECU 13 that executes this routine corresponds to the failure diagnosis means of the present invention.

ステップＳ１０１では、内燃機関１が減速時であるか否かを判別する。内燃機関１が減速時あるか否かは、アクセルポジションセンサ１５等の出力信号から判断される。   In step S101, it is determined whether or not the internal combustion engine 1 is decelerating. Whether or not the internal combustion engine 1 is decelerating is determined from an output signal from the accelerator position sensor 15 or the like.

ステップＳ１０１において肯定判定された場合には、ステップＳ１０２へ移行する。ステップＳ１０１において否定判定された場合には、本ルーチンを一旦終了する。   If a positive determination is made in step S101, the process proceeds to step S102. If a negative determination is made in step S101, this routine is once terminated.

ステップＳ１０２では、排気絞り弁１２を可能な限り閉じると共に低圧ＥＧＲ弁３２を全開にする。排気絞り弁１２を全閉にしてしまうと内燃機関１から排出される排気が詰まり内燃機関１に悪影響を及ぼすので、排気絞り弁１２を可能な限り閉じることとしている。ここで、排気絞り弁１２を可能な限り閉じるとは、例えば、排気絞り弁１２のアクチュエータに通常供給している電力で全閉指令を出し、この指令にもかかわらず排気絞り弁１２が全閉とならなければ、排気絞り弁１２をその閉じ開度で維持することで達成される。   In step S102, the exhaust throttle valve 12 is closed as much as possible and the low-pressure EGR valve 32 is fully opened. If the exhaust throttle valve 12 is fully closed, the exhaust discharged from the internal combustion engine 1 is clogged and adversely affects the internal combustion engine 1. Therefore, the exhaust throttle valve 12 is closed as much as possible. Here, to close the exhaust throttle valve 12 as much as possible, for example, a full close command is issued with the electric power normally supplied to the actuator of the exhaust throttle valve 12, and the exhaust throttle valve 12 is fully closed in spite of this command. If not, it is achieved by maintaining the exhaust throttle valve 12 at its closed opening.

ステップＳ１０３では、エアフローメータ７で検知する新気の量の変化量が所定量Ｃｇよりも少ないか否かを判別する。具体的には、ステップＳ１０２以前のエアフローメータ７で検知する新気の量と、ステップＳ１０２以後のエアフローメータ７で検知する新気の量との差の絶対値を変化量とし、当該変化量と所定量Ｃｇとを比較して行う。   In step S103, it is determined whether or not the amount of change in the amount of fresh air detected by the air flow meter 7 is less than a predetermined amount Cg. Specifically, the absolute value of the difference between the amount of fresh air detected by the air flow meter 7 before step S102 and the amount of fresh air detected by the air flow meter 7 after step S102 is defined as the amount of change, and the amount of change Comparison is made with a predetermined amount Cg.

ステップＳ１０３において肯定判定された場合には、ステップＳ１０４へ移行する。ステップＳ１０３において否定判定された場合には、本ルーチンを一旦終了する。   If a positive determination is made in step S103, the process proceeds to step S104. If a negative determination is made in step S103, this routine is once terminated.

ステップＳ１０４では、排気圧力センサ１０で検知する排気の圧力が所定圧力Ｃｐよりも小さいか否かを判別する。   In step S104, it is determined whether or not the exhaust pressure detected by the exhaust pressure sensor 10 is smaller than a predetermined pressure Cp.

ステップＳ１０４において肯定判定された場合には、ステップＳ１０５へ移行する。ステップＳ１０４において否定判定された場合には、ステップＳ１０６へ移行する。   If a positive determination is made in step S104, the process proceeds to step S105. If a negative determination is made in step S104, the process proceeds to step S106.

ステップＳ１０５では、排気絞り弁１２の開故障と診断する。本ステップの処理の後、本ルーチンを一旦終了する。   In step S105, the exhaust throttle valve 12 is diagnosed as having an open failure. After the processing of this step, this routine is once ended.

一方、ステップＳ１０６では、低圧ＥＧＲ弁３２の閉故障と診断する。本ステップの処理の後、本ルーチンを一旦終了する。   On the other hand, in step S106, it is diagnosed that the low pressure EGR valve 32 is closed. After the processing of this step, this routine is once ended.

本ルーチンによると、内燃機関１が減速している一定時間内に、排気絞り弁１２を可能な限り閉じると共に低圧ＥＧＲ弁３２を全開にする制御を行うことで、容易に、排気絞り弁１２の開故障と低圧ＥＧＲ弁３２の閉故障とを同時に区別して診断することができる。   According to this routine, the exhaust throttle valve 12 is controlled to be closed as much as possible and the low pressure EGR valve 32 is fully opened within a certain time during which the internal combustion engine 1 is decelerating. An open failure and a closed failure of the low pressure EGR valve 32 can be distinguished and diagnosed at the same time.

本発明に係る内燃機関の故障診断装置は、上述の実施例に限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々の変更を加えてもよい。   The failure diagnosis apparatus for an internal combustion engine according to the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the gist of the present invention.

実施例１に係る内燃機関の概略構成を示す図。1 is a diagram illustrating a schematic configuration of an internal combustion engine according to a first embodiment. 実施例１に係る故障診断ルーチンを示すフローチャート。5 is a flowchart illustrating a failure diagnosis routine according to the first embodiment.

符号の説明Explanation of symbols

１ 内燃機関
２ 気筒
３ 燃料噴射弁
４ 吸気通路
５ 排気通路
６ ターボチャージャ
６ａ コンプレッサ
６ｂ タービン
７ エアフローメータ
８ インタークーラ
９ スロットル弁
１０ 排気圧力センサ
１１ ＤＰＦ
１２ 排気絞り弁
１３ ＥＣＵ
１４ クランクポジションセンサ
１５ アクセルポジションセンサ
３０ 低圧ＥＧＲ装置
３１ 低圧ＥＧＲ通路
３２ 低圧ＥＧＲ弁 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder 3 Fuel injection valve 4 Intake passage 5 Exhaust passage 6 Turbocharger 6a Compressor 6b Turbine 7 Air flow meter 8 Intercooler 9 Throttle valve 10 Exhaust pressure sensor 11 DPF
12 Exhaust throttle valve 13 ECU
14 Crank position sensor 15 Accelerator position sensor 30 Low pressure EGR device 31 Low pressure EGR passage 32 Low pressure EGR valve

Claims (1)

内燃機関の排気通路に配置されたタービン及び前記内燃機関の吸気通路に配置されたコンプレッサを有するターボチャージャと、
前記タービンより下流の前記排気通路から排気の一部を低圧ＥＧＲガスとして取り込み、前記コンプレッサより上流の前記吸気通路へ当該低圧ＥＧＲガスを還流させる低圧ＥＧＲ通路と、
前記低圧ＥＧＲ通路に配置され、前記低圧ＥＧＲ通路内を流通する低圧ＥＧＲガスの量を調節する低圧ＥＧＲ弁と、
前記低圧ＥＧＲ通路との接続部位より下流の前記排気通路に配置され、前記排気通路内を流通する排気の量を調節する排気絞り弁と、
前記低圧ＥＧＲ通路との接続部位より上流の前記吸気通路に配置され、前記吸気通路内を流通する新気の量を検知する新気量検知手段と、
前記タービンより下流且つ前記排気絞り弁より上流の前記排気通路に配置され、前記排気通路内を流通する排気の圧力を検知する排気圧力検知手段と、
前記内燃機関の減速時に、前記排気絞り弁を可能な限り閉じると共に前記低圧ＥＧＲ弁を全開にし、前記新気量検知手段が検知する新気の量の変化量が所定量より少なく、且つ、前記排気圧力検知手段が検知する排気の圧力が所定圧力より小さい場合には、前記排気絞り弁が開いたまま閉じられない排気絞り弁開故障と診断し、前記新気量検知手段が検知する新気の量の変化量が所定量より少なく、且つ、前記排気圧力検知手段が検知する排気の圧力が所定圧力以上の場合には、前記低圧ＥＧＲ弁が閉じたまま開かない低圧ＥＧＲ弁閉故障と診断する故障診断手段と、
を備えることを特徴とする内燃機関の故障診断装置。
A turbocharger having a turbine disposed in an exhaust passage of an internal combustion engine and a compressor disposed in an intake passage of the internal combustion engine;
A low pressure EGR passage that takes in a part of exhaust gas as low pressure EGR gas from the exhaust passage downstream from the turbine and recirculates the low pressure EGR gas to the intake passage upstream from the compressor;
A low-pressure EGR valve that is disposed in the low-pressure EGR passage and adjusts the amount of low-pressure EGR gas flowing through the low-pressure EGR passage;
An exhaust throttle valve that is disposed in the exhaust passage downstream of the connection portion with the low-pressure EGR passage and adjusts the amount of exhaust flowing through the exhaust passage;
A fresh air amount detecting means which is disposed in the intake passage upstream of the connection portion with the low pressure EGR passage and detects the amount of fresh air flowing through the intake passage;
An exhaust pressure detecting means that is disposed in the exhaust passage downstream from the turbine and upstream from the exhaust throttle valve, and detects the pressure of the exhaust gas flowing through the exhaust passage;
At the time of deceleration of the internal combustion engine, the exhaust throttle valve is closed as much as possible and the low pressure EGR valve is fully opened, and the amount of change in the amount of fresh air detected by the fresh air amount detecting means is less than a predetermined amount, and When the exhaust pressure detected by the exhaust pressure detecting means is smaller than a predetermined pressure, it is diagnosed that the exhaust throttle valve is not closed while the exhaust throttle valve is open, and the fresh air detected by the new air quantity detecting means is diagnosed. If the change amount of the exhaust gas is less than a predetermined amount and the exhaust pressure detected by the exhaust pressure detecting means is equal to or higher than the predetermined pressure, the low pressure EGR valve is diagnosed as being closed with the low pressure EGR valve closed. Fault diagnosis means to
A failure diagnosis apparatus for an internal combustion engine, comprising:
JP2008305006A 2008-11-28 2008-11-28 Fault diagnosis device for internal combustion engine Expired - Fee Related JP4941458B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008305006A JP4941458B2 (en) 2008-11-28 2008-11-28 Fault diagnosis device for internal combustion engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008305006A JP4941458B2 (en) 2008-11-28 2008-11-28 Fault diagnosis device for internal combustion engine

Publications (2)

Publication Number Publication Date
JP2010127243A JP2010127243A (en) 2010-06-10
JP4941458B2 true JP4941458B2 (en) 2012-05-30

Family

ID=42327807

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008305006A Expired - Fee Related JP4941458B2 (en) 2008-11-28 2008-11-28 Fault diagnosis device for internal combustion engine

Country Status (1)

Country Link
JP (1) JP4941458B2 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5795947B2 (en) * 2011-11-24 2015-10-14 愛三工業株式会社 Exhaust gas recirculation device for supercharged engine
DE102012204756A1 (en) * 2012-03-26 2013-09-26 Robert Bosch Gmbh Method and device for fault monitoring in an exhaust gas recirculation
JP6093258B2 (en) 2013-07-08 2017-03-08 愛三工業株式会社 Failure detection device for exhaust gas recirculation device of supercharged engine
JP5965361B2 (en) * 2013-07-08 2016-08-03 愛三工業株式会社 Internal combustion engine system failure detection apparatus and internal combustion engine system failure detection method
GB201410197D0 (en) * 2014-06-09 2014-07-23 Delphi International Operations Luxembourg S.�.R.L. Exhaust gas recirculation testing method
CN111413100B (en) * 2020-03-26 2022-03-08 安徽华菱汽车有限公司 Error reporting method and system for simulating exhaust gas circulation quantity abnormality of EGR (exhaust gas recirculation) system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4352651B2 (en) * 2002-03-27 2009-10-28 トヨタ自動車株式会社 Abnormality determination device for internal combustion engine
JP2008121519A (en) * 2006-11-10 2008-05-29 Toyota Motor Corp Abnormality determining device of exhaust throttle valve and wastegate valve
JP2008128114A (en) * 2006-11-21 2008-06-05 Toyota Motor Corp Exhaust throttle valve failure diagnostic device for internal combustion engine
JP4687663B2 (en) * 2007-02-15 2011-05-25 トヨタ自動車株式会社 Abnormality diagnosis device for exhaust gas recirculation system
JP4893383B2 (en) * 2007-03-09 2012-03-07 トヨタ自動車株式会社 Exhaust gas recirculation device for internal combustion engine
JP4761222B2 (en) * 2007-05-16 2011-08-31 トヨタ自動車株式会社 Energy recovery equipment

Also Published As

Publication number Publication date
JP2010127243A (en) 2010-06-10

Similar Documents

Publication Publication Date Title
JP4333725B2 (en) Exhaust gas recirculation device for internal combustion engine
RU2490494C2 (en) Diagnostics method of failures of exhaust gas pressure control, and corresponding diagnostics device
US7895838B2 (en) Exhaust gas recirculation apparatus of an internal combustion engine and control method thereof
CN101484684B (en) Exhaust gas recirculation device of internal combustion engine, and control method thereof
JP4737335B2 (en) EGR system for internal combustion engine
JP2008215168A (en) Exhaust throttle valve diagnosis device and method
JP4941458B2 (en) Fault diagnosis device for internal combustion engine
JP2008002351A (en) Exhaust gas recirculation device for internal combustion engine
EP2674597A1 (en) Control device for internal combustion engine
JP2008240576A (en) Failure diagnosis device for turbocharging system
JP2013096372A (en) Control device of internal combustion engine with supercharger
JP4748396B2 (en) Exhaust throttle valve failure diagnosis device for internal combustion engine
JP2008128114A (en) Exhaust throttle valve failure diagnostic device for internal combustion engine
US8397700B2 (en) Abnormality diagnosis device for exhaust gas recirculation device
JP2008133779A (en) Diagnosis device for differential pressure sensor
JP4893383B2 (en) Exhaust gas recirculation device for internal combustion engine
JP4760671B2 (en) Fault detection system for differential pressure sensor
JP2010242617A (en) Abnormality detection system for internal combustion engine
JP4978513B2 (en) Engine gas leak detection device
JP2010169008A (en) Abnormality detector for pressure sensor
JP2010190176A (en) Abnormality determination device for internal combustion engine
JP2010127238A (en) Control device for internal combustion engine
JP2020122464A (en) Diagnostic device for egr cooler
JP2011185096A (en) Exhaust recirculation device for internal combustion engine
JP2007291975A (en) Exhaust recirculation device of internal combustion engine

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110126

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120123

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120131

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120213

R151 Written notification of patent or utility model registration

Ref document number: 4941458

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150309

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees