JP6774003B2 - Exhaust gas circulation failure diagnostic device for hybrid vehicles - Google Patents

Exhaust gas circulation failure diagnostic device for hybrid vehicles Download PDF

Info

Publication number
JP6774003B2
JP6774003B2 JP2016055724A JP2016055724A JP6774003B2 JP 6774003 B2 JP6774003 B2 JP 6774003B2 JP 2016055724 A JP2016055724 A JP 2016055724A JP 2016055724 A JP2016055724 A JP 2016055724A JP 6774003 B2 JP6774003 B2 JP 6774003B2
Authority
JP
Japan
Prior art keywords
exhaust gas
gas circulation
engine
operating point
failure diagnosis
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.)
Active
Application number
JP2016055724A
Other languages
Japanese (ja)
Other versions
JP2017170927A (en
Inventor
賢寛 古田
賢寛 古田
松永 英雄
英雄 松永
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.)
Mitsubishi Motors Corp
Original Assignee
Mitsubishi Motors 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 Mitsubishi Motors Corp filed Critical Mitsubishi Motors Corp
Priority to JP2016055724A priority Critical patent/JP6774003B2/en
Publication of JP2017170927A publication Critical patent/JP2017170927A/en
Application granted granted Critical
Publication of JP6774003B2 publication Critical patent/JP6774003B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/60Other road transportation technologies with climate change mitigation effect
    • Y02T10/62Hybrid vehicles
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/60Other road transportation technologies with climate change mitigation effect
    • Y02T10/7072Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Landscapes

  • Combined Controls Of Internal Combustion Engines (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)
  • Hybrid Electric Vehicles (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Control Of Vehicle Engines Or Engines For Specific Uses (AREA)

Description

本発明は、ハイブリッド車両の排ガス循環故障診断装置に係り、詳しくは車両に搭載されたエンジンの排ガス循環装置の故障を診断する故障診断装置に関する。 The present invention relates to an exhaust gas circulation failure diagnosis device for a hybrid vehicle, and more particularly to a failure diagnosis device for diagnosing a failure of an engine exhaust gas circulation device mounted on a vehicle.

車両に搭載されたエンジンの排ガス中に含まれるNOxを低減する装置として、エンジンの排気側と吸気側とを接続する排ガス循環通路を経て排ガスを排ガス循環ガスとして吸気側に環流させることにより、筒内での燃焼温度を低下させてNOxの生成を抑制する排ガス循環装置が知られている。吸気側への排ガス循環ガスの環流量は、排ガス循環通路に介装された排ガス循環バルブの開度をエンジンの運転領域に応じて制御することで最適化を図っている。しかし、排ガス循環バルブの故障や排ガス循環通路の詰まり等により所期の排ガス循環還流量を達成不能になる場合があり、排ガス循環環流量が不足するとNOx排出量の増加を引き起こし、排ガス循環環流量が過剰になると燃焼悪化によるドライバビリティの低下、或いは排ガス中のHC、CO、黒煙等の増加を引き起こす。 As a device to reduce NOx contained in the exhaust gas of the engine mounted on the vehicle, the exhaust gas is circulated to the intake side as the exhaust gas circulation gas through the exhaust gas circulation passage connecting the exhaust side and the intake side of the engine. There is known an exhaust gas circulation device that lowers the combustion temperature inside and suppresses the generation of NOx. The circulation flow rate of the exhaust gas circulating gas to the intake side is optimized by controlling the opening degree of the exhaust gas circulation valve interposed in the exhaust gas circulation passage according to the operating region of the engine. However, the desired exhaust gas circulation circulation amount may not be achieved due to a failure of the exhaust gas circulation valve or clogging of the exhaust gas circulation passage, and if the exhaust gas circulation circulation flow rate is insufficient, the NOx emission amount will increase and the exhaust gas circulation circulation flow rate will increase. Excessive amount causes a decrease in drivability due to deterioration of combustion, or an increase in HC, CO, black smoke, etc. in the exhaust gas.

このため、例えば特許文献1に記載のように、車両には排ガス循環装置が正常に機能しているか否かを診断する排ガス循環故障診断装置が備えられている。特許文献1に記載の車両は、走行モードの1つとしてシリーズモードを実行可能に構成されており、シリーズモードでは、エンジンによりモータジェネレータを駆動し、その発電電力を走行モータの駆動や走行バッテリの充電に利用している。 Therefore, for example, as described in Patent Document 1, the vehicle is provided with an exhaust gas circulation failure diagnosis device for diagnosing whether or not the exhaust gas circulation device is functioning normally. The vehicle described in Patent Document 1 is configured to be able to execute the series mode as one of the traveling modes. In the series mode, the motor generator is driven by the engine, and the generated power is used to drive the traveling motor or the traveling battery. It is used for charging.

シリーズモードでのエンジンの運転点は、走行バッテリへの目標充電電力に応じて決定される。車両の走行中において、走行バッテリの実SOC(充電率:State Of Charge)と目標SOCとの偏差に基づき目標充電電力が逐次算出され、目標充電電力に対応するモータジェネレータの目標発電量を最小燃費で達成可能な運転点でエンジンが運転される。
このようなシリーズモードでの走行中に排ガス循環装置の故障診断は実施され、排ガス循環バルブを開弁及び閉弁したときのインテークマニホールド圧(以下、インマニ圧という)の変化に基づき、排ガス循環装置の正常・異常が判定される。インマニ圧はエンジンの回転速度や負荷の影響を受けるためエンジンの運転点を定める必要があり、また診断精度の点から排ガス循環バルブの開閉に伴いインマニ圧が明確に変化する運転点が望ましい。このような観点の下に、通常時のシリーズモードでのエンジンの運転点よりも低負荷側に予めモニタ領域が設定され、故障診断時には、モニタ領域の中央に目標運転点を定めてエンジンを運転している。このため故障診断時には、例えば図3に示すようにモニタ領域内の●印の運転点でエンジンが運転される。
The operating point of the engine in series mode is determined according to the target charge power to the traveling battery. While the vehicle is running, the target charge power is sequentially calculated based on the deviation between the actual SOC (charge rate: State Of Charge) of the running battery and the target SOC, and the target power generation amount of the motor generator corresponding to the target charge power is minimized. The engine is operated at the achievable operating point.
Failure diagnosis of the exhaust gas circulation device is carried out while driving in such a series mode, and the exhaust gas circulation device is based on the change in the intake manifold pressure (hereinafter referred to as the intake manifold pressure) when the exhaust gas circulation valve is opened and closed. Normal / abnormal is judged. Since the intake manifold pressure is affected by the rotation speed and load of the engine, it is necessary to determine the operating point of the engine, and from the viewpoint of diagnostic accuracy, it is desirable to have an operating point where the intake manifold pressure clearly changes as the exhaust gas circulation valve opens and closes. From this point of view, the monitor area is set in advance on the lower load side than the engine operating point in the normal series mode, and at the time of failure diagnosis, the target operating point is set in the center of the monitor area and the engine is operated. are doing. Therefore, at the time of failure diagnosis, for example, as shown in FIG. 3, the engine is operated at the operation point marked with ● in the monitor area.

特開2013−78995号公報Japanese Unexamined Patent Publication No. 2013-78995

ところで、走行バッテリが満充電近くで充電を必要としない状況、或いは極低温で正常な充電が望めない状況(共に充電電力を制限すべき状況であり、以下、電池受入れ性の低下時と表現する)では、走行バッテリの保護のために目標充電電力が制限される。しかしながら、特許文献1に記載のハイブリッド車両の排ガス循環故障診断装置では、このように目標充電電力が制限されると、エンジンの運転点がモニタ領域内から逸脱して排ガス循環装置の故障診断を完了できないという問題があった。 By the way, the situation where the traveling battery is near full charge and does not need to be charged, or the situation where normal charging cannot be expected at extremely low temperature (both are situations where the charging power should be limited, and hereinafter, it is expressed as a time when the battery acceptability is lowered. ), The target charging power is limited to protect the running battery. However, in the exhaust gas circulation failure diagnosis device of the hybrid vehicle described in Patent Document 1, when the target charging power is limited in this way, the operating point of the engine deviates from the monitoring area and the failure diagnosis of the exhaust gas circulation device is completed. There was a problem that it could not be done.

即ち、電池受入れ性の低下時には、排ガス循環の故障診断よりも走行バッテリの保護が優先される結果、目標充電電力ひいてはモータジェネレータの目標発電量が制限される。そして、目標発電量が制限されることにより、エンジンの運転点は図3に○印で示すようにモニタ領域内から低負荷側に逸脱してしまう。
このため、モニタ領域内の図中の●印の運転点で排ガス循環装置の故障診断を実施しているときに、走行バッテリの電池受入れ性が低下した場合、或いは走行バッテリの電池受入れ性電池受入れ性の低下によりモニタ領域外の○印の運転点でエンジンを運転しているときに、排ガス循環装置の故障診断の実施条件が成立した場合には、モニタ領域内の●印の運転点に保つべくエンジン制御が試行されるが、バッテリ保護の優先によりモニタ領域外の○印の運転点に戻されてしまう。結果として、2つの運転点を行き来するハンチング現象が生じて排ガス循環装置の故障診断を完了できず、故障診断の頻度が減少してしまうという問題があった。
That is, when the battery acceptability is lowered, the protection of the traveling battery is prioritized over the failure diagnosis of the exhaust gas circulation, and as a result, the target charging power and the target power generation amount of the motor generator are limited. Then, due to the limitation of the target power generation amount, the operating point of the engine deviates from the monitor area to the low load side as shown by a circle in FIG.
For this reason, when the failure diagnosis of the exhaust gas circulation device is performed at the operation point marked with ● in the figure in the monitor area, the battery acceptability of the traveling battery deteriorates, or the battery acceptability of the traveling battery is accepted. When the engine is operating at the operating point marked with a circle outside the monitor area due to deterioration of the property, if the conditions for performing the failure diagnosis of the exhaust gas circulation device are satisfied, keep it at the operating point marked with a circle in the monitor area. The engine control is tried, but due to the priority of battery protection, it is returned to the operation point marked with a circle outside the monitoring area. As a result, there is a problem that a hunting phenomenon that goes back and forth between the two operating points occurs, the failure diagnosis of the exhaust gas circulation device cannot be completed, and the frequency of the failure diagnosis decreases.

本発明はこのような問題点を解決するためになされたもので、その目的とするところは、走行バッテリの電池受入れ性の低下時においても、目標充電電力の制限により走行バッテリを保護しつつ、排ガス循環装置の故障診断を実施することができるハイブリッド車両の排ガス循環故障診断装置を提供することにある。 The present invention has been made to solve such a problem, and an object of the present invention is to protect the traveling battery by limiting the target charging power even when the battery acceptability of the traveling battery is lowered. An object of the present invention is to provide an exhaust gas circulation failure diagnosis device for a hybrid vehicle capable of performing a failure diagnosis of an exhaust gas circulation device.

上記の目的を達成するため、本発明のハイブリッド車両の排ガス循環故障診断装置は、エンジンを所定の運転点で運転して発電機を駆動し、該発電機により発電された電力をバッテリに充電する充電制御手段と、前記バッテリへの充電電力を制限すべき電池受入れ性の低下時か否かを判定する電池受入れ性判定手段と、前記電池受入れ性判定手段により電池受入れ性の低下時と判定されたときに、前記バッテリへの充電電力を制限すべく前記エンジンの運転点を負荷低下方向に切り換え、発電電力を低下させる充電電力制限手段と、前記エンジンの排ガスを循環させる排ガス循環手段と、前記排ガス循環手段の故障診断の実施条件が成立したときに、前記エンジンの運転点を負荷と回転速度で規定されるモニタ領域内に保ちながら前記排ガス循環手段の故障診断を実施する排ガス循環故障診断手段と、前記排ガス循環故障診断手段により前記排ガス循環手段の故障判定が実施される際に、前記電池受入れ性判定手段の判定に基づき前記エンジンの運転点が負荷低下方向に切り換えられると前記モニタ領域を逸脱する場合に、前記エンジンの運転領域の変更又は前記モニタ領域を拡大する制御手段と、前記モニタ領域を負荷低下方向に拡大して前記運転点を前記拡大されたモニタ領域内に保つ第1のモニタ領域拡大手段とを備え、前記第1のモニタ領域拡大手段による前記モニタ領域の拡大時には、通常時に比較して排ガス循環バルブの開弁時の開度を縮小することを特徴とする(請求項1)。 In order to achieve the above object, the exhaust gas circulation failure diagnosis device for a hybrid vehicle of the present invention operates an engine at a predetermined operating point to drive a generator, and charges a battery with the power generated by the generator. The charge control means, the battery acceptability determining means for determining whether or not the battery acceptability for which the charging power to the battery should be limited is deteriorated, and the battery acceptability determining means determine that the battery acceptability is deteriorated. At that time, the charging power limiting means for reducing the generated power by switching the operating point of the engine in the load reduction direction in order to limit the charging power to the battery, the exhaust gas circulating means for circulating the exhaust gas of the engine, and the above. When the conditions for performing the failure diagnosis of the exhaust gas circulation means are satisfied, the exhaust gas circulation failure diagnosis means for carrying out the failure diagnosis of the exhaust gas circulation means while keeping the operating point of the engine within the monitor area defined by the load and the rotation speed. When the failure determination of the exhaust gas circulation failure means is performed by the exhaust gas circulation failure diagnosis means, the monitoring area is changed when the operating point of the engine is switched in the load reduction direction based on the determination of the battery acceptability determination means. When deviating, the control means for changing the operating area of the engine or expanding the monitoring area, and the first method for expanding the monitoring area in the load reduction direction and keeping the operating point within the expanded monitoring area. and a monitor area enlarging means, wherein at the time of expansion of the monitoring area of the first monitor area enlargement means, characterized in that to reduce the opening at the valve opening of the exhaust gas circulation valve in comparison to the normal time (according Item 1).

このように構成したハイブリッド車両の排ガス循環故障診断装置によれば、排ガス循環故障診断手段により排ガス循環手段の故障判定が実施される際に、電池受入れ性判定手段の判定によって排ガス循環装置の故障診断が行われる頻度が向上する。
また、排ガス循環故障診断手段により排ガス循環手段の故障判定が実施される際に、電池受入れ性判定手段の判定に基づきエンジンの運転点が負荷低下方向に切り換えられるとモニタ領域を逸脱する場合には、モニタ領域が負荷低下方向に拡大される。従って、バッテリ保護のために充電電力を制限しながら、エンジンの運転点をモニタ領域内に保って排ガス循環手段の故障診断を実施可能となる。
また、このときのエンジンは負荷低下方向の運転点で運転されて燃焼悪化を生じる可能性があるが、通常時に比較して排ガス循環バルブの開弁時の開度が縮小されることにより燃焼悪化が抑制される。
According to the exhaust gas circulation failure diagnosis device of the hybrid vehicle configured in this way, when the failure determination of the exhaust gas circulation failure means is performed by the exhaust gas circulation failure diagnosis means, the failure diagnosis of the exhaust gas circulation device is made by the determination of the battery acceptability determination means. Is done more often.
Further, when the failure determination of the exhaust gas circulation failure means is performed by the exhaust gas circulation failure diagnosis means, if the operating point of the engine is switched in the load reduction direction based on the determination of the battery acceptability determination means, the monitor area is deviated. , The monitor area is expanded in the direction of load reduction. Therefore, it is possible to keep the operating point of the engine within the monitor area and perform a failure diagnosis of the exhaust gas circulation means while limiting the charging power for battery protection.
In addition, the engine at this time may be operated at the operating point in the load reduction direction to cause combustion deterioration, but combustion deterioration is caused by the opening opening of the exhaust gas circulation valve being reduced as compared with the normal time. Is suppressed.

その他の態様として、前記排ガス循環故障診断装置が、前記モニタ領域の拡大時に、通常時に比較して前記排ガス循環バルブの開弁時の開度を縮小すると共に、前記吸気側の圧力変化を判定する故障判定値として小さな値を適用することが好ましい(請求項)。
この態様によれば、排ガス循環バルブの開度が縮小されると、全閉時との差圧が縮小されるが、通常時に比較して故障判定値として小さな値が適用されるため、通常時と同様の判定が可能になる。
As another aspect, the exhaust gas circulation failure diagnosis device reduces the opening degree of the exhaust gas circulation valve when the valve is opened as compared with the normal time when the monitoring area is expanded, and determines the pressure change on the intake side. It is preferable to apply a small value as the failure determination value (claim 2 ).
According to this aspect, when the opening degree of the exhaust gas circulation valve is reduced, the differential pressure from that when fully closed is reduced, but since a small value is applied as a failure determination value as compared with the normal time, the normal time The same judgment as is possible.

その他の態様として、前記排ガス循環故障診断装置が、前記モニタ領域を回転増加方向に拡大する第2のモニタ領域拡大手段と、前記第2のモニタ領域拡大手段による前記モニタ領域の拡大時に、前記エンジンの運転点を回転増加方向に切り換える第2の運転点補正手段とを有することが好ましい(請求項)。
この態様によれば、排ガス循環排ガス循環故障診断手段により排ガス循環手段の故障判定が実施される際に、電池受入れ性判定手段の判定に基づきエンジンの運転点が負荷低下方向に切り換えられるとモニタ領域を逸脱する場合に、モニタ領域が回転増加方向に拡大されると共に、エンジンの運転点が回転増加方向に切り換えられる。エンジンの運転点はモニタ領域から負荷低下方向に逸脱しているものの、回転速度の増加によりエンジンの燃焼状態が安定化することから、バッテリ保護のために充電電力を制限しながら、排ガス循環手段の故障診断を実施可能となる。
As another aspect, when the exhaust gas circulation failure diagnosis device expands the monitor area by the second monitor area expanding means for expanding the monitor area in the rotation increasing direction and the monitor area expanding means by the second monitor area expanding means, the engine It is preferable to have a second operating point correction means for switching the operating point of the above in the direction of increasing rotation (claim 3 ).
According to this aspect, when the failure determination of the exhaust gas circulation means is performed by the exhaust gas circulation exhaust gas circulation failure diagnosis means, when the operating point of the engine is switched in the load reduction direction based on the judgment of the battery acceptability determination means, the monitor area When the vehicle deviates from the above, the monitoring area is expanded in the direction of increasing rotation, and the operating point of the engine is switched in the direction of increasing rotation. Although the operating point of the engine deviates from the monitoring area in the direction of load reduction, the combustion state of the engine stabilizes due to the increase in the rotation speed. Therefore, while limiting the charging power to protect the battery, the exhaust gas circulation means It becomes possible to carry out failure diagnosis.

その他の態様として、前記排ガス循環故障診断装置が、前記第2の運転点補正手段による前記運転点の切換時に、通常時に比較して前記排ガス循環バルブの開弁時の開度を拡大する排ガス循環バルブ拡大手段を有することが好ましい(請求項)。
この態様によれば、エンジンの回転増加により、排ガス循環バルブの開閉に伴うエンジンの吸気側の圧力変化が縮小傾向になって誤判定し易くなるが、通常時に比較して排ガス循環バルブの開弁時の開度が拡大されることにより的確に判定可能となる。
As another embodiment, the exhaust gas circulation failure diagnosis device expands the opening degree of the exhaust gas circulation valve at the time of opening the exhaust gas circulation valve when the operation point is switched by the second operation point correction means as compared with the normal time. It is preferable to have a valve expanding means (claim 4 ).
According to this aspect, due to the increase in engine rotation, the pressure change on the intake side of the engine due to the opening and closing of the exhaust gas circulation valve tends to decrease, which makes it easy to make an erroneous determination. Accurate determination becomes possible by expanding the opening degree of time.

前記排ガス循環故障診断装置が、前記エンジンの負荷を保ちつつ該エンジンの回転速度を低下させて、前記充電電力を制限しながら前記運転点を前記モニタ領域内に保つ第1の運転点補正手段を備えることが好ましい(請求項)。
このように構成したハイブリッド車両の排ガス循環故障診断装置によれば、排ガス循環故障診断手段により排ガス循環手段の故障判定が実施される際に、電池受入れ性判定手段の判定に基づきエンジンの運転点が負荷低下方向に切り換えられるとモニタ領域を逸脱する場合には、エンジンの負荷を保ちつつエンジンの回転速度を低下させることから、バッテリ保護のために充電電力を制限しながら、エンジンの運転点をモニタ領域内に保って排ガス循環手段の故障診断を実施可能となる。
The exhaust gas circulation failure diagnosis device provides a first operating point correction means for reducing the rotation speed of the engine while maintaining the load of the engine and keeping the operating point within the monitoring region while limiting the charging power. It is preferable to provide (claim 5 ).
According to the exhaust gas circulation failure diagnosis device of the hybrid vehicle configured in this way, when the failure determination of the exhaust gas circulation failure means is performed by the exhaust gas circulation failure diagnosis means, the operating point of the engine is determined based on the judgment of the battery acceptability determination means. If the engine deviates from the monitor area when the load is switched in the direction of reduction, the engine rotation speed is reduced while maintaining the engine load. Therefore, the operating point of the engine is monitored while limiting the charging power to protect the battery. It is possible to carry out failure diagnosis of the exhaust gas circulation means while keeping it within the area.

その他の態様として、前記排ガス循環故障診断装置が、前記第1の運転点補正手段により前記エンジンの運転点を前記モニタ領域内に保てる場合には該第1の運転点補正手段に処理を実行させ、前記第1の運転点補正手段により前記運転点をモニタ領域内に保てない場合には、前記第1のモニタ領域拡大手段または前記第2のモニタ領域拡大手段に処理を実行させる対応切換手段を有することが好ましい(請求項)。 As another aspect, when the exhaust gas circulation failure diagnosis device can keep the operating point of the engine within the monitor area by the first operating point correcting means, the first operating point correcting means is made to execute the process. When the operating point cannot be kept in the monitor area by the first operating point correcting means, the corresponding switching means for causing the first monitoring area expanding means or the second monitoring area expanding means to execute the process. It is preferable to have (claim 6 ).

このように構成したハイブリッド車両の排ガス循環故障診断装置によれば、第1の運転点補正手段の処理では、安定した燃焼が望める本来のモニタ領域内でエンジンを運転させながら故障診断を実施することから、診断精度が最も高い。第1のモニタ領域拡大手段の処理では、より確実にエンジンの運転点をモニタ領域内に保てるが、負荷が低下した運転点でエンジンを運転するため、燃焼悪化によって診断精度が劣る。同じく第2のモニタ領域拡大手段の処理もエンジンの燃焼悪化が生じ、さらにエンジン回転を高めることにより騒音及び振動面で不利になる。 According to the exhaust gas circulation failure diagnosis device of the hybrid vehicle configured in this way, in the processing of the first operating point correction means, the failure diagnosis is performed while operating the engine within the original monitoring area where stable combustion can be expected. Therefore, the diagnostic accuracy is the highest. In the process of the first monitor area expanding means, the operating point of the engine can be more reliably maintained in the monitor area, but since the engine is operated at the operating point where the load is reduced, the diagnostic accuracy is inferior due to the deterioration of combustion. Similarly, the processing of the second monitor area expanding means also causes deterioration of engine combustion, and further increases engine rotation, which is disadvantageous in terms of noise and vibration.

そして本発明によれば、まず第1の運転点補正手段の処理が優先して実施されることから高い診断精度が得られ、且つ第1の運転点補正手段の処理が実施不能な場合には第1のモニタ領域拡大手段または第2のモニタ領域拡大手段の処理が実施されるため、これにより電池受入れ性の低下時であっても故障診断を実施可能となる。 According to the present invention, since the processing of the first operating point correction means is performed with priority, high diagnostic accuracy can be obtained, and when the processing of the first operating point correction means cannot be performed. Since the processing of the first monitor area expanding means or the second monitoring area expanding means is performed, it is possible to carry out the failure diagnosis even when the battery acceptability is lowered.

本発明のハイブリッド車両の排ガス循環故障診断装置によれば、走行バッテリの電池受入れ性の低下時においても、目標充電電力の制限により走行バッテリを保護しつつ、排ガス循環装置の故障診断を実施することができる。 According to the exhaust gas circulation failure diagnosis device of the hybrid vehicle of the present invention, even when the battery acceptability of the traveling battery deteriorates, the failure diagnosis of the exhaust gas circulation device is performed while protecting the traveling battery by limiting the target charging power. Can be done.

実施形態の排ガス循環故障診断装置が適用されたプラグインハイブリッド車両を示す全体構成図である。It is an overall block diagram which shows the plug-in hybrid vehicle to which the exhaust gas circulation failure diagnosis apparatus of embodiment is applied. エンジンに備えられた排ガス循環装置を示す構成図である。It is a block diagram which shows the exhaust gas circulation device provided in an engine. 第1実施形態の故障診断時のモニタ領域内でのエンジンの運転点を示すマップである。It is a map which shows the operating point of the engine in the monitor area at the time of failure diagnosis of 1st Embodiment. 第2実施形態の故障診断の実施状況を示すタイムチャートである。It is a time chart which shows the implementation state of the failure diagnosis of 2nd Embodiment. 第3実施形態の故障診断の実施状況を示すタイムチャートである。It is a time chart which shows the implementation state of the failure diagnosis of 3rd Embodiment.

以下、本発明をプラグインハイブリッド車両(以下、車両1という)の排ガス循環故障診断装置に具体化した一実施形態を説明する。
図1は本実施形態の排ガス循環故障診断装置が適用されたプラグインハイブリッド車両を示す全体構成図である。
本実施形態の車両1は、フロントモータ2の出力またはフロントモータ2及びエンジン3の出力により前輪4を駆動し、リヤモータ5の出力により後輪6を駆動するように構成された4輪駆動車である。
Hereinafter, an embodiment in which the present invention is embodied in an exhaust gas circulation failure diagnosis device for a plug-in hybrid vehicle (hereinafter referred to as vehicle 1) will be described.
FIG. 1 is an overall configuration diagram showing a plug-in hybrid vehicle to which the exhaust gas circulation failure diagnosis device of the present embodiment is applied.
The vehicle 1 of the present embodiment is a four-wheel drive vehicle configured to drive the front wheels 4 by the output of the front motor 2 or the outputs of the front motor 2 and the engine 3, and drive the rear wheels 6 by the output of the rear motor 5. is there.

エンジン3の出力軸は減速機7を介して前輪4の駆動軸8と連結され、減速機7には内部の動力伝達を断接可能なクラッチ9が内蔵されている。クラッチ9の接続時にはエンジン3の駆動力が減速機7及び駆動軸8を経て前輪4に伝達され、クラッチ9の切断時には前輪4側からエンジン3が切り離されて単独で運転可能となる。
減速機7のクラッチ9より動力伝達方向の下流側(前輪4側)にはフロントモータ2が連結され、その駆動力が減速機7から駆動軸8を経て前輪4に伝達されるようになっている。また、減速機7のクラッチ9より動力伝達方向の上流側(反前輪4側)にはモータジェネレータ10が連結され、クラッチ9の切断時において、モータジェネレータ10はエンジン3の駆動により発電したり、或いはエンジン3を始動するスタータモータとして機能したりする。また、リヤモータ5は減速機11を介して後輪6の駆動軸12と連結され、その駆動力が減速機11から駆動軸12を経て後輪6に伝達されるようになっている。
The output shaft of the engine 3 is connected to the drive shaft 8 of the front wheels 4 via the speed reducer 7, and the speed reducer 7 has a built-in clutch 9 capable of connecting and disconnecting internal power transmission. When the clutch 9 is connected, the driving force of the engine 3 is transmitted to the front wheels 4 via the speed reducer 7 and the drive shaft 8, and when the clutch 9 is disengaged, the engine 3 is disconnected from the front wheels 4 side and can be operated independently.
A front motor 2 is connected to the downstream side (front wheel 4 side) in the power transmission direction from the clutch 9 of the speed reducer 7, and the driving force thereof is transmitted from the speed reducer 7 to the front wheels 4 via the drive shaft 8. There is. Further, a motor generator 10 is connected to the upstream side (anti-front wheel 4 side) in the power transmission direction from the clutch 9 of the speed reducer 7, and when the clutch 9 is disengaged, the motor generator 10 generates electricity by driving the engine 3. Alternatively, it functions as a starter motor for starting the engine 3. Further, the rear motor 5 is connected to the drive shaft 12 of the rear wheels 6 via the speed reducer 11, and the driving force thereof is transmitted from the speed reducer 11 to the rear wheels 6 via the drive shaft 12.

エンジン3には、入出力装置、記憶装置(ROM、RAM、不揮発性RAM等)、中央演算処理装置(CPU)等から構成されたエンジンコントローラ14が接続され、このエンジンコントローラ14によりエンジン3のスロットル開度、燃料噴射量、点火時期等が制御されてエンジン3が運転される。
フロントモータ2、リヤモータ5及びモータジェネレータ10は三相交流電動機であり、それらの電源として走行バッテリ15(バッテリ)が備えられている。走行バッテリ15はリチウムイオン電池等の二次電池から構成され、そのSOC(充電率)の算出や温度TBATの検出を行うバッテリモニタリングユニット15aを内蔵している。
An engine controller 14 composed of an input / output device, a storage device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), and the like is connected to the engine 3, and the throttle of the engine 3 is connected by the engine controller 14. The engine 3 is operated by controlling the opening degree, the fuel injection amount, the ignition timing, and the like.
The front motor 2, the rear motor 5, and the motor generator 10 are three-phase AC electric motors, and a traveling battery 15 (battery) is provided as a power source for them. The traveling battery 15 is composed of a secondary battery such as a lithium ion battery, and has a built-in battery monitoring unit 15a that calculates its SOC (charge rate) and detects the temperature TBAT.

フロントモータ2及びモータジェネレータ10はフロントモータコントローラ16を介して走行バッテリ15に接続され、フロントモータコントローラ16にはフロントモータ用インバータ16a及びモータジェネレータ用インバータ16bが備えられている。走行バッテリ15の直流電力は、フロントモータ用インバータ16a及びモータジェネレータ用インバータ16bにより三相交流電力に変換されてフロントモータ2やモータジェネレータ10に供給される。また、フロントモータ2による回生電力やモータジェネレータ10による発電電力は、フロントモータ用インバータ16a及びモータジェネレータ用インバータ16bにより直流電力に変換されて走行バッテリ15に充電される。 The front motor 2 and the motor generator 10 are connected to the traveling battery 15 via the front motor controller 16, and the front motor controller 16 is provided with a front motor inverter 16a and a motor generator inverter 16b. The DC power of the traveling battery 15 is converted into three-phase AC power by the front motor inverter 16a and the motor generator inverter 16b and supplied to the front motor 2 and the motor generator 10. Further, the regenerated electric power by the front motor 2 and the generated electric power by the motor generator 10 are converted into DC electric power by the front motor inverter 16a and the motor generator inverter 16b, and the traveling battery 15 is charged.

同様に、リヤモータ5はリヤモータコントローラ17を介して走行バッテリ15に接続され、リヤモータコントローラ17にはリヤモータ用インバータ17aが備えられている。走行バッテリ15の直流電力は、リヤモータ用インバータ17aにより三相交流電力に変換されてリヤモータ5に供給され、リヤモータ5による回生電力は、リヤモータ用インバータ17aにより直流電力に変換されて走行バッテリ15に充電される。 Similarly, the rear motor 5 is connected to the traveling battery 15 via the rear motor controller 17, and the rear motor controller 17 is provided with a rear motor inverter 17a. The DC power of the traveling battery 15 is converted into three-phase AC power by the rear motor inverter 17a and supplied to the rear motor 5, and the regenerated power by the rear motor 5 is converted into DC power by the rear motor inverter 17a and charged to the traveling battery 15. Will be done.

また、車両1には、走行バッテリ15を外部電源によって充電する充電機13が備えられている。
ハイブリッドコントローラ18は、車両1の総合的な制御を行うための制御装置であり、入出力装置、記憶装置(ROM、RAM、不揮発性RAM等)、中央演算処理装置(CPU)等から構成されている。このハイブリッドコントローラ18により、エンジン3、フロントモータ2、モータジェネレータ10、リヤモータ5の各運転状態、及び減速機7のクラッチ9の断接状態等が制御される。そのために、ハイブリッドコントローラ18の入力側には、走行バッテリ15のバッテリモニタリングユニット15a、フロントモータコントローラ16、リヤモータコントローラ17、エンジンコントローラ14、アクセル開度θaccを検出するアクセル開度センサ19、及び車速Vを検出する車速センサ20が接続されており、これらの機器からの検出及び作動情報が入力される。
Further, the vehicle 1 is provided with a charger 13 that charges the traveling battery 15 with an external power source.
The hybrid controller 18 is a control device for performing comprehensive control of the vehicle 1, and is composed of an input / output device, a storage device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), and the like. There is. The hybrid controller 18 controls the operating states of the engine 3, the front motor 2, the motor generator 10, the rear motor 5, the disengagement state of the clutch 9 of the speed reducer 7, and the like. Therefore, on the input side of the hybrid controller 18, the battery monitoring unit 15a of the traveling battery 15, the front motor controller 16, the rear motor controller 17, the engine controller 14, the accelerator opening sensor 19 for detecting the accelerator opening θacc, and the vehicle speed A vehicle speed sensor 20 that detects V is connected, and detection and operation information from these devices is input.

また、ハイブリッドコントローラ18の出力側には、フロントモータコントローラ16、リヤモータコントローラ17、減速機7のクラッチ9、及びエンジンコントローラ14が接続されている。
そして、ハイブリッドコントローラ18は、アクセル開度センサ19等の上記各種検出量及び作動情報に基づき、車両1の走行モードをEVモード、シリーズモード、パラレルモードの間で切り換える。例えば、高速領域のようにエンジン3の効率が高い領域では、走行モードをパラレルモードとする。また、中低速領域では、走行バッテリ15の充電率SOCや運転領域に基づきEVモードとシリーズモードとの間で切り換える。
Further, a front motor controller 16, a rear motor controller 17, a clutch 9 of the speed reducer 7, and an engine controller 14 are connected to the output side of the hybrid controller 18.
Then, the hybrid controller 18 switches the traveling mode of the vehicle 1 between the EV mode, the series mode, and the parallel mode based on the various detection amounts and operation information of the accelerator opening sensor 19 and the like. For example, in a region where the efficiency of the engine 3 is high, such as a high-speed region, the traveling mode is set to the parallel mode. Further, in the medium-low speed region, the EV mode and the series mode are switched based on the charge rate SOC of the traveling battery 15 and the operating region.

EVモードでは、減速機7のクラッチ9を切断すると共にエンジン3を停止し、走行バッテリ15からの電力によりフロントモータ2やリヤモータ5を駆動して車両1を走行させる。
シリーズモードでは、減速機7のクラッチ9を切断した上で、エンジン3を運転してモータジェネレータ10を駆動し、その発電電力及び走行バッテリ15からの電力によりフロントモータ2やリヤモータ5を駆動して車両1を走行させると共に、余剰電力を走行バッテリ15に充電する。
In the EV mode, the clutch 9 of the speed reducer 7 is disengaged, the engine 3 is stopped, and the front motor 2 and the rear motor 5 are driven by the electric power from the traveling battery 15 to drive the vehicle 1.
In the series mode, after disengaging the clutch 9 of the speed reducer 7, the engine 3 is operated to drive the motor generator 10, and the front motor 2 and the rear motor 5 are driven by the generated power and the power from the traveling battery 15. The vehicle 1 is driven and the traveling battery 15 is charged with surplus electric power.

パラレルモードでは、減速機7のクラッチ9を接続した上で、エンジン3を運転して駆動力を減速機7から前輪4に伝達すると共に、エンジン駆動力に余剰があるときには、フロントモータ2で回生し、エンジン駆動力が足りないときには、バッテリ電力を使ってフロントモータ2でアシストする。
また、ハイブリッドコントローラ18は、上記各種検出量及び作動情報に基づき車両1の走行に必要な総要求出力を算出し、その総要求出力を、EVモード及びシリーズモードではフロントモータ2側とリヤモータ5側とに配分し、パラレルモードではフロントモータ2側とエンジン3側とリヤモータ5側とに配分する。そして、それぞれに配分した要求出力、及びフロントモータ2から前輪4までの減速機7のギヤ比、エンジン3から前輪4までの減速機7のギヤ比、リヤモータ5から後輪6までの減速機11のギヤ比に基づき、フロントモータ2、エンジン3、リヤモータ5のそれぞれの要求トルクを設定し、各要求トルクを達成するようにフロントモータコントローラ16、リヤモータコントローラ17及びエンジンコントローラ14に指令信号を出力する。
In the parallel mode, after connecting the clutch 9 of the reducer 7, the engine 3 is operated to transmit the driving force from the reducer 7 to the front wheels 4, and when there is a surplus in the engine driving force, the front motor 2 regenerates the engine. However, when the engine driving force is insufficient, the front motor 2 assists using the battery power.
Further, the hybrid controller 18 calculates the total required output required for traveling of the vehicle 1 based on the various detected amounts and operation information, and calculates the total required output on the front motor 2 side and the rear motor 5 side in the EV mode and the series mode. In the parallel mode, it is distributed to the front motor 2 side, the engine 3 side, and the rear motor 5 side. Then, the required output distributed to each, the gear ratio of the reduction gear 7 from the front motor 2 to the front wheels 4, the gear ratio of the reduction gear 7 from the engine 3 to the front wheels 4, and the reduction gear 11 from the rear motor 5 to the rear wheels 6 The required torques of the front motor 2, the engine 3, and the rear motor 5 are set based on the gear ratios of the above, and command signals are output to the front motor controller 16, the rear motor controller 17, and the engine controller 14 so as to achieve each required torque. To do.

フロントモータコントローラ16及びリヤモータコントローラ17ではハイブリッドコントローラ18からの指令信号に基づき、要求トルクを達成するためにフロントモータ2及びリヤモータ5の各相のコイルに流すべき目標電流値を算出する。そして、それらの目標電流値に基づきフロントモータ用インバータ16a及びリヤモータ用インバータ17aをスイッチング制御し、それぞれの要求トルクを達成する。尚、モータジェネレータ10の発電時も同様であり、負側の要求トルクから求めた目標電流値に基づき、モータジェネレータ用インバータ16bをスイッチング制御して要求トルクを達成する。 The front motor controller 16 and the rear motor controller 17 calculate a target current value to be passed through the coils of each phase of the front motor 2 and the rear motor 5 in order to achieve the required torque based on the command signal from the hybrid controller 18. Then, the front motor inverter 16a and the rear motor inverter 17a are switched and controlled based on these target current values to achieve the required torques for each. The same applies to the power generation of the motor generator 10, and the required torque is achieved by switching control of the motor generator inverter 16b based on the target current value obtained from the required torque on the negative side.

エンジンコントローラ14ではハイブリッドコントローラ18からの指令信号に基づき、要求トルクの達成のためのスロットル開度、燃料噴射量、点火時期等の目標値を算出し、それらの目標値に基づく制御によりエンジン3を運転して要求トルクを達成する。
また、ハイブリッドコントローラ18は、シリーズモードによる車両1の走行中において走行バッテリ15の充電状態を最適化すべく、モータジェネレータ10を駆動しているエンジン3の運転点を制御している。具体的には、走行バッテリ15の実SOCと目標SOCとの偏差に基づき目標充電電力を逐次算出し、目標充電電力に対応するモータジェネレータ10の目標発電量を最小燃費で達成可能な運転点を求め、その運転点でエンジン3を運転する。概括的に表現すると、走行バッテリ15のSOCが増加して満充電に近づくほど目標充電電力が低下し、エンジン3の運転点は低負荷側に移行する(充電制御手段)。
The engine controller 14 calculates target values such as throttle opening, fuel injection amount, and ignition timing for achieving the required torque based on the command signal from the hybrid controller 18, and controls the engine 3 based on those target values. Drive to achieve the required torque.
Further, the hybrid controller 18 controls the operating point of the engine 3 driving the motor generator 10 in order to optimize the charging state of the traveling battery 15 while the vehicle 1 is traveling in the series mode. Specifically, the target charging power is sequentially calculated based on the deviation between the actual SOC of the traveling battery 15 and the target SOC, and the operating point at which the target power generation amount of the motor generator 10 corresponding to the target charging power can be achieved with the minimum fuel consumption is determined. Find and drive the engine 3 at that operating point. Generally speaking, as the SOC of the traveling battery 15 increases and the battery approaches full charge, the target charging power decreases, and the operating point of the engine 3 shifts to the low load side (charge control means).

加えて、ハイブリッドコントローラ18は、走行バッテリ15の電池受入れ性の低下(満充電近くで充電を必要としない状況、或いは極低温で正常な充電が望めない状況)を常に監視しており(電池受入れ性判定手段)、電池受入れ性の低下判定を下したとき場合には、走行バッテリ15の保護のために目標充電電流を制限する処理を実施する(充電電力制限手段)。 In addition, the hybrid controller 18 constantly monitors the deterioration of the battery acceptability of the traveling battery 15 (a situation in which charging is not required near full charge or a situation in which normal charging cannot be expected at extremely low temperatures) (battery acceptance). (Sexity determination means), when it is determined that the battery acceptability is lowered, a process of limiting the target charging current is performed to protect the traveling battery 15 (charging power limiting means).

例えば、以下の1),2)の条件の成立時に、走行バッテリ15の電池受入れ性が低下したと判定する。
1)最大充電電力―目標充電電力≦制限電力判定値(例えば10kw)
2)充電電流>制限電流判定値またはバッテリ電圧>制限電圧判定値
ここに、最大充電電力は、走行バッテリ15のSOH(劣化指標:State of Health)やSOCや温度等から定まる現在の走行バッテリ15が充電可能な上限電力である。
For example, when the following conditions 1) and 2) are satisfied, it is determined that the battery acceptability of the traveling battery 15 has deteriorated.
1) Maximum charge power-Target charge power ≤ Power limit judgment value (for example, 10 kW)
2) Charging current> current limit judgment value or battery voltage> limit voltage judgment value Here, the maximum charging power is the current running battery 15 determined by the SOH (deterioration index: State of Health), SOC, temperature, etc. of the running battery 15. Is the maximum power that can be charged.

このような電池受入れ性の低下判定を下すと、ハイブリッドコントローラ18は走行バッテリ15への目標充電電力を制限する。必然的にモータジェネレータ10の目標発電量が低下することから、エンジン制御側でエンジン3の運転点が低負荷側に切り換えられる。
一方、エンジン3には排ガス中に含まれるNOxを低減するために排ガス循環装置21が備えられており、その構成を図2に示す。
When the determination of the decrease in battery acceptability is made, the hybrid controller 18 limits the target charging power to the traveling battery 15. Since the target power generation amount of the motor generator 10 inevitably decreases, the operating point of the engine 3 is switched to the low load side on the engine control side.
On the other hand, the engine 3 is provided with an exhaust gas circulation device 21 in order to reduce NOx contained in the exhaust gas, and the configuration thereof is shown in FIG.

排ガス循環装置21は、エンジン3のエキゾーストマニホールド24(排気側)とインテークマニホールド25(吸気側)とを接続する排ガス循環通路22、及び排ガス循環通路22の開度を調整する排ガス循環バルブ23から構成されている。排ガス循環バルブ23の開度はエンジン3の運転領域に基づきハイブリッドコントローラ18により制御され、排ガス循環バルブ23の開度に応じて排ガスが排ガス循環通路22を経て排ガス循環ガスとして吸気側に還流され、これにより筒内での燃焼温度が低下してNOxの生成が抑制される。 The exhaust gas circulation device 21 includes an exhaust gas circulation passage 22 that connects the exhaust manifold 24 (exhaust side) and the intake manifold 25 (intake side) of the engine 3, and an exhaust gas circulation valve 23 that adjusts the opening degree of the exhaust gas circulation passage 22. Has been done. The opening degree of the exhaust gas circulation valve 23 is controlled by the hybrid controller 18 based on the operating region of the engine 3, and the exhaust gas is returned to the intake side as the exhaust gas circulation gas through the exhaust gas circulation passage 22 according to the opening degree of the exhaust gas circulation valve 23. As a result, the combustion temperature in the cylinder is lowered and the generation of NOx is suppressed.

そして、排ガス循環バルブ23の故障や排ガス循環通路22の詰まり等により所期の排ガス循環還流量を達成不能になると、エミッションやドライバビリティの面で種々の不具合が生じることから、車両1には排ガス循環装置21の故障を診断する排ガス循環故障診断装置(排ガス循環故障診断手段)が備えられている。本実施形態では排ガス循環故障診断装置として、インテークマニホールド25に設けられた圧力センサ26及びハイブリッドコントローラ18が機能し、後述するように、ハイブリッドコントローラ18が圧力センサ26により検出される排ガス循環バルブ23の全閉(0%)時と所定量開(20%)時との差圧ΔPを故障判定値と比較して、排ガス循環装置21の正常・異常を判定する。 If the desired amount of exhaust gas circulation and recirculation cannot be achieved due to a failure of the exhaust gas circulation valve 23, clogging of the exhaust gas circulation passage 22, or the like, various problems occur in terms of emission and drivability. Therefore, the vehicle 1 has exhaust gas. An exhaust gas circulation failure diagnosis device (exhaust gas circulation failure diagnosis means) for diagnosing a failure of the circulation device 21 is provided. In the present embodiment, the pressure sensor 26 and the hybrid controller 18 provided in the intake manifold 25 function as the exhaust gas circulation failure diagnosis device, and as will be described later, the exhaust gas circulation valve 23 in which the hybrid controller 18 is detected by the pressure sensor 26. The normality / abnormality of the exhaust gas circulation device 21 is determined by comparing the differential pressure ΔP between when fully closed (0%) and when the predetermined amount is opened (20%) with the failure determination value.

排ガス循環装置21の故障診断は車両1がシリーズモードで走行しているときに実施され、エンジン3の回転速度Ne及び充填効率Ec(負荷)により規定されるエンジン3の運転点は、走行バッテリ15への目標充電電力に基づく通常時の値から、故障診断に好適なより低負荷側の値に切り換えられる。具体的には、予め故障診断のためのモニタ領域(例えば1250〜1750rpm,15〜25%)が設定され、そのモニタ領域の中央をエンジン3の目標運転点(例えば1500rpm,20%)として定めている。 The failure diagnosis of the exhaust gas circulation device 21 is performed when the vehicle 1 is traveling in the series mode, and the operating point of the engine 3 defined by the rotation speed Ne of the engine 3 and the filling efficiency Ec (load) is the traveling battery 15. The value at the normal time based on the target charging power to is switched to the value on the lower load side suitable for failure diagnosis. Specifically, a monitor area for failure diagnosis (for example, 1250 to 1750 rpm, 15 to 25%) is set in advance, and the center of the monitor area is set as a target operating point of the engine 3 (for example, 1500 rpm, 20%). There is.

図3は故障診断時のモニタ領域内でのエンジン3の運転点を示すマップであり、例えば図中にハッチング枠で示すようにモニタ領域が設定され、モニタ領域内の●印で示す運転点でエンジン3を運転しながら故障診断が実施される。なお、図中に併記しているように、エンジン3の回転速度Neが増加するほど、或いは充填効率Ecが増加するほど、失火が抑制されてエンジン3の燃焼状態が良好になる反面、排ガス循環バルブ23の開閉に伴う差圧ΔPが縮小して故障診断を誤判定する可能性が高まる。 FIG. 3 is a map showing the operating points of the engine 3 in the monitor area at the time of failure diagnosis. For example, the monitor area is set as shown by the hatch frame in the figure, and the operating points indicated by ● in the monitor area. Failure diagnosis is carried out while operating the engine 3. As shown in the figure, as the rotation speed Ne of the engine 3 increases or the filling efficiency Ec increases, misfire is suppressed and the combustion state of the engine 3 becomes better, but the exhaust gas circulation The differential pressure ΔP accompanying the opening and closing of the valve 23 is reduced, increasing the possibility of erroneously determining the failure diagnosis.

このようにモニタ領域に基づき故障診断が実施されるのであるが、[発明が解決しようとする課題]で述べたように、電池受入れ性の低下時には、排ガス循環の故障診断よりも走行バッテリ15の保護が優先される結果、エンジン3の運転点が図3に○印で示すようにモニタ領域から低負荷側に逸脱してしまい、排ガス循環装置21の故障診断を完了できないという問題があった。 In this way, the failure diagnosis is carried out based on the monitor area, but as described in [Problems to be solved by the invention], when the battery acceptability is lowered, the traveling battery 15 is used rather than the failure diagnosis of the exhaust gas circulation. As a result of giving priority to protection, the operating point of the engine 3 deviates from the monitor area to the low load side as shown by a circle in FIG. 3, and there is a problem that the failure diagnosis of the exhaust gas circulation device 21 cannot be completed.

このような不具合を鑑みて本発明者は、走行バッテリ15の保護のために目標充電電力を制限しつつ排ガス循環装置21の故障診断を完了するために、以下の2種の対策を見出した。
その1つは、モニタ領域内でのエンジン3の運転点を最適化して故障診断を実施可能とする手法であり、他の1つは、モニタ領域を拡大する手法である。以下、前段の手法を第1実施形態として、後段の手法を第2及び第3実施形態として説明する。
[第1実施形態]
モータジェネレータ10の発電量は、基本的にエンジン3の回転速度Neと充填効率Ecとの積で定まる。このため、例えば図3に示す30kw及び20kwの特性線のようにモータジェネレータ10の発電量が表わされ、これらの特性線上であれば、どの運転点であっても対応する発電量が達成される。そして、例えば電池受入れ性の低下に基づきモータジェネレータ10の目標発電量が30kwから20kwに制限されると、負荷(充填効率Ec)低下方向にはモニタ領域の余地がほとんどないのに対し、回転速度Neの低下方向にはある程度の余地が存在することが判る。そこで、エンジン3の運転点を、負荷低下方向に代えて回転低下方向に切り換える手法を採用したものが本実施形態である。
In view of such a defect, the present inventor has found the following two measures in order to complete the failure diagnosis of the exhaust gas circulation device 21 while limiting the target charging power for the protection of the traveling battery 15.
One is a method of optimizing the operating point of the engine 3 in the monitor area to enable failure diagnosis, and the other is a method of expanding the monitor area. Hereinafter, the first-stage method will be described as the first embodiment, and the second-stage method will be described as the second and third embodiments.
[First Embodiment]
The amount of power generated by the motor generator 10 is basically determined by the product of the rotation speed Ne of the engine 3 and the filling efficiency Ec. Therefore, for example, the power generation amount of the motor generator 10 is represented as shown in the characteristic lines of 30 kW and 20 kW shown in FIG. 3, and the corresponding power generation amount is achieved at any operating point on these characteristic lines. To. Then, for example, when the target power generation amount of the motor generator 10 is limited from 30 kW to 20 kW based on the decrease in battery acceptability, there is almost no room for a monitor area in the direction of decrease in load (filling efficiency Ec), whereas the rotation speed. It can be seen that there is some room in the downward direction of Ne. Therefore, the present embodiment employs a method of switching the operating point of the engine 3 in the rotation decreasing direction instead of the load decreasing direction.

従って、本実施形態によれば、モニタ領域内の図中の●印の運転点で排ガス循環装置21の故障診断を実施しているとき、走行バッテリ15の電池受入れ性の低下によりモータジェネレータ10の目標発電量を30kwから20kwに制限すべく、エンジン3の運転点を負荷低下方向に切り換えるとモニタ領域を逸脱してしまう場合に、現在のエンジン3の充填効率Ecを保ちつつ回転速度Neを低下させて、図中の□印に運転点を切り換える(第1の運転点補正手段)。 Therefore, according to the present embodiment, when the failure diagnosis of the exhaust gas circulation device 21 is performed at the operation point marked with ● in the figure in the monitor area, the motor generator 10 is affected by the deterioration of the battery acceptability of the traveling battery 15. In order to limit the target power generation amount from 30 kW to 20 kW, if the operating point of the engine 3 is switched to the load reduction direction and the monitor area is deviated, the rotation speed Ne is reduced while maintaining the current filling efficiency Ec of the engine 3. Then, the operating point is switched to the □ mark in the figure (first operating point correction means).

また、走行バッテリ15の電池受入れ性の低下により、モータジェネレータ10の目標発電量を20kwに制限すべく図中の○印の運転点でエンジン3を運転しているときに、排ガス循環装置21の故障診断の実施条件(例えばスロットル開度が一定、冷却水温が所定範囲内等)が成立すると、エンジン3の充填効率Ecを増加させ且つ回転速度Neを低下させながら、20kwの特性線上でエンジン3の運転点を□印まで移動させる。 Further, when the engine 3 is operated at the operation point marked with a circle in the figure in order to limit the target power generation amount of the motor generator 10 to 20 kW due to the decrease in the battery acceptability of the traveling battery 15, the exhaust gas circulation device 21 When the conditions for performing the failure diagnosis (for example, the throttle opening is constant, the cooling water temperature is within the predetermined range, etc.) are satisfied, the engine 3 is operated on the characteristic line of 20 kW while increasing the filling efficiency Ec of the engine 3 and decreasing the rotation speed Ne. Move the operating point of to the □ mark.

何れの場合も、モータジェネレータ10の目標発電量、ひいては走行バッテリ15の目標充電電力が制限されると共に、エンジン3の運転点がモニタ領域内に保たれる。よって、本実施形態によれば、走行バッテリ15の電池受入れ性の低下時においても、目標充電電力の制限により走行バッテリ15を保護しつつ、エンジン3の運転点をモニタ領域内に保って排ガス循環装置21の故障診断を実施することができる。
[第2実施形態]
上記したようにモニタ領域はエンジン3の回転速度Ne及び充填効率Ecにより規定されており、モータジェネレータ10の目標発電量の制限によりエンジン3の運転点が充填効率Ecの下限を下回った場合に、排ガス循環装置21の故障診断を実施不能な事態に陥る。そこで、走行バッテリ15の電池受入れ性の低下時に限り、モニタ領域を負荷低下方向に拡大すること、より詳しくはモニタ領域の充填効率Ecに関する下限を低下させることにより、エンジン3の運転点を切り換えることなくモニタ領域内に保つ手法を採用したものが本実施形態である。
In either case, the target power generation amount of the motor generator 10 and the target charging power of the traveling battery 15 are limited, and the operating point of the engine 3 is kept within the monitor area. Therefore, according to the present embodiment, even when the battery acceptability of the traveling battery 15 is lowered, the exhaust gas circulation is performed while keeping the operating point of the engine 3 within the monitoring region while protecting the traveling battery 15 by limiting the target charging power. Failure diagnosis of the device 21 can be performed.
[Second Embodiment]
As described above, the monitor area is defined by the rotation speed Ne of the engine 3 and the filling efficiency Ec, and when the operating point of the engine 3 falls below the lower limit of the filling efficiency Ec due to the limitation of the target power generation amount of the motor generator 10. The failure diagnosis of the exhaust gas circulation device 21 cannot be performed. Therefore, only when the battery acceptability of the traveling battery 15 is lowered, the operating point of the engine 3 is switched by expanding the monitor area in the load lowering direction, and more specifically, lowering the lower limit of the filling efficiency Ec of the monitor area. In this embodiment, a method of keeping the battery within the monitor area is adopted.

図4は本実施形態の故障診断の実施状況を示すタイムチャートである。説明の前提として、故障診断のためのモニタ領域がエンジン3の回転速度Ne1250〜1750rpm、充填効率Ec15〜25%に予め設定され、その中央の回転速度Ne1500rpm、充填効率Ec20%が故障診断時の目標運転点として設定され、さらに電池受入れ性の低下時には、エンジン3の運転点がモータジェネレータ10の発電制限のために充填効率Ec10%(図3中の○印)まで低下するものとする。 FIG. 4 is a time chart showing the implementation status of the failure diagnosis of the present embodiment. As a premise of the explanation, the monitoring area for failure diagnosis is preset to the rotation speed Ne1250 to 1750 rpm and the filling efficiency Ec15 to 25% of the engine 3, and the central rotation speed Ne1500 rpm and the filling efficiency Ec20% are the targets at the time of failure diagnosis. It is set as an operating point, and when the battery acceptability is further lowered, the operating point of the engine 3 is assumed to be lowered to a filling efficiency Ec10% (marked with a circle in FIG. 3) due to the power generation limitation of the motor generator 10.

まず、走行バッテリ15の電池受入れ性が低下してない通常時の故障診断について述べる。排ガス循環装置21の故障診断の実施条件が成立していないとき、上記したように、エンジン3はモータジェネレータ10の目標発電量を最小燃費で達成可能な運転点で運転され、排ガス循環バルブ23はエンジン3の運転領域に応じた開度に制御されている。
故障診断の実施条件が成立すると、モニタ領域へのエンジン3の運転点の切換要求がなされ、それに呼応してエンジン3の運転点がモニタ領域内の目標運転点に切り換えられる。モータジェネレータ10が発電制限されていないため、エンジン3は何ら問題なく目標運転点で運転されてモニタ領域内に保たれ続ける。この時点で排ガス循環バルブ23が一旦全閉(0%)された上で、圧力センサ26によるインマニ圧の検出値が第1圧力P1として記憶され、その後に排ガス循環バルブ23が所定量開(20%)されて、インマニ圧の検出値が第2圧力P2として記憶される。これらの第1及び第2圧力P1,P2の差圧ΔPが予め設定された故障判定値以上のときには排ガス循環装置21の正常判定を下し、故障判定値未満のときには異常判定を下す。
First, a failure diagnosis in a normal state in which the battery acceptability of the traveling battery 15 is not deteriorated will be described. When the conditions for performing the failure diagnosis of the exhaust gas circulation device 21 are not satisfied, as described above, the engine 3 is operated at the operating point where the target power generation amount of the motor generator 10 can be achieved with the minimum fuel consumption, and the exhaust gas circulation valve 23 is operated. The opening degree is controlled according to the operating region of the engine 3.
When the failure diagnosis execution condition is satisfied, a request for switching the operating point of the engine 3 to the monitor area is made, and the operating point of the engine 3 is switched to the target operating point in the monitor area in response to the request. Since the motor generator 10 is not restricted in power generation, the engine 3 is operated at the target operating point without any problem and continues to be kept within the monitor area. At this point, the exhaust gas circulation valve 23 is once fully closed (0%), the detection value of the intake manifold pressure by the pressure sensor 26 is stored as the first pressure P1, and then the exhaust gas circulation valve 23 is opened by a predetermined amount (20). %), And the detected value of the intake manifold pressure is stored as the second pressure P2. When the differential pressure ΔP of the first and second pressures P1 and P2 is equal to or higher than the preset failure determination value, the exhaust gas circulation device 21 makes a normal determination, and when it is less than the failure determination value, an abnormality determination is made.

なお、正常・異常の判定後には故障診断の実施条件が不成立となり、エンジン3は再びモータジェネレータ10の目標発電量に基づく運転点で運転され、エンジン3の運転領域に応じて排ガス循環バルブ23の開度が制御される。
一方、走行バッテリ15の電池受入れ性が低下している場合について述べる。このときのエンジン3の運転点は、モータジェネレータ10の発電制限によりモニタ領域の下限の充填効率Ec15%を下回る10%まで低下しているため、通常であればモニタ領域を逸脱していると見なされて故障診断は開始されない。本実施形態では、故障診断の実施条件が成立した時点で、図3に仮想線で示すように、モニタ領域の下限が充填効率Ec15%から10%に切り換えられて負荷低下方向に拡大される(第1のモニタ領域拡大手段)。このため、図4中に破線で示すように充填効率Ec10%のエンジン3の運転点であっても、運転点がモニタ領域内に保たれていると見なされ、問題なく故障診断が開始される。
After the normal / abnormal determination, the failure diagnosis implementation condition is not satisfied, the engine 3 is operated again at the operating point based on the target power generation amount of the motor generator 10, and the exhaust gas circulation valve 23 is operated according to the operating region of the engine 3. The opening is controlled.
On the other hand, a case where the battery acceptability of the traveling battery 15 is lowered will be described. At this time, the operating point of the engine 3 is lowered to 10%, which is lower than the lower limit filling efficiency Ec15% of the monitor area due to the power generation limitation of the motor generator 10, so that it is normally considered to deviate from the monitor area. It is done and the failure diagnosis is not started. In the present embodiment, when the execution condition of the failure diagnosis is satisfied, the lower limit of the monitor area is switched from the filling efficiency Ec 15% to 10% and is expanded in the load reduction direction as shown by the virtual line in FIG. First monitor area expansion means). Therefore, as shown by the broken line in FIG. 4, even at the operating point of the engine 3 having a filling efficiency of Ec10%, the operating point is considered to be kept within the monitor area, and the failure diagnosis is started without any problem. ..

そして、この電池受入れ性が低下しているときの故障診断では、通常時とは異なる排ガス循環バルブ23の開度及び故障判定値が適用され、その趣旨は以下に述べる通りである。
[背景技術]で述べたように、モニタ領域は診断精度等を配慮した結果、シリーズモードでの通常時の運転に比較して低負荷側に設定されおり、その下限である充填効率Ec15%は、排ガス循環バルブ23を全開しても排ガス循環ガスによりエンジン3の燃焼状態が悪化して失火に至らない限界付近の値として設定されている。このような燃焼安定性に関してほとんど余裕がないモニタ領域の下限を、本実施形態ではさらに充填効率Ec10%まで低下させるため、エンジン3の燃焼悪化により正常な故障診断が望めない可能性がある。
Then, in the failure diagnosis when the battery acceptability is lowered, the opening degree and the failure determination value of the exhaust gas circulation valve 23 different from the normal time are applied, and the purpose thereof is as described below.
As described in [Background Technology], the monitor area is set to the lower load side compared to the normal operation in the series mode as a result of considering the diagnostic accuracy, etc., and the lower limit of the filling efficiency Ec15% is set. Even if the exhaust gas circulation valve 23 is fully opened, the combustion state of the engine 3 is deteriorated by the exhaust gas circulation gas, and the value is set near the limit that does not lead to misfire. In this embodiment, the lower limit of the monitor region, which has almost no margin for combustion stability, is further lowered to a filling efficiency of Ec of 10%, so that a normal failure diagnosis may not be expected due to deterioration of combustion of the engine 3.

そこで本実施形態では、電池受入れ性が低下しているときの故障診断時に、排ガス循環バルブ23の開度を通常時に適用される全開よりも小開度、例えば図4中に破線で示す10%にとどめて燃焼悪化を抑制している。また、排ガス循環バルブ23の開度が小さくなると、図4中に破線で示すように全閉時との差圧ΔPが縮小されるため、それに応じて故障判定値に関しても通常時よりも小さな値を適用している。 Therefore, in the present embodiment, at the time of failure diagnosis when the battery acceptability is lowered, the opening degree of the exhaust gas circulation valve 23 is smaller than the fully opened opening applied at normal times, for example, 10% shown by a broken line in FIG. It only suppresses the deterioration of combustion. Further, when the opening degree of the exhaust gas circulation valve 23 becomes smaller, the differential pressure ΔP from the fully closed state is reduced as shown by the broken line in FIG. 4, so that the failure determination value is also smaller than the normal time. Is applied.

以上のように本実施形態によれば、電池受入れ性の低下によりエンジン3の運転点を充填効率Ec10%まで低下させている状態で故障診断の実施条件が成立したときに、モニタ領域の下限を充填効率Ec10%まで低下させて負荷低下方向に拡大している。このため、エンジン3の運転点がモニタ領域内に保たれ、問題なく故障診断を実施できる。
そして、故障診断時の排ガス循環バルブ23の開度を通常時の全開よりも小開度にとどめているため、排ガス循環ガスの環流に起因するエンジン3の燃焼悪化を抑制できる。さらに、排ガス循環バルブ開度の縮小に対応する適切な故障判定値を適用するため、通常時と同様に排ガス循環装置21の正常・異常を的確に判定できる。結果として本実施形態によれば、走行バッテリ15の電池受入れ性の低下時においても、目標充電電力の制限により走行バッテリ15を保護しつつ、エンジン3の運転点をモニタ領域内に保って排ガス循環装置21の故障診断を実施することができる。
As described above, according to the present embodiment, when the execution condition of the failure diagnosis is satisfied in a state where the operating point of the engine 3 is lowered to the filling efficiency Ec10% due to the deterioration of the battery acceptability, the lower limit of the monitor area is set. The filling efficiency Ec is reduced to 10% and the load is decreasing. Therefore, the operating point of the engine 3 is kept within the monitor area, and the failure diagnosis can be performed without any problem.
Since the opening degree of the exhaust gas circulation valve 23 at the time of failure diagnosis is kept smaller than the opening degree at the time of normal operation, it is possible to suppress the deterioration of combustion of the engine 3 due to the recirculation of the exhaust gas circulating gas. Further, since an appropriate failure determination value corresponding to the reduction of the exhaust gas circulation valve opening degree is applied, the normality / abnormality of the exhaust gas circulation device 21 can be accurately determined as in the normal case. As a result, according to the present embodiment, even when the battery acceptability of the traveling battery 15 is lowered, the traveling battery 15 is protected by the limitation of the target charging power, and the operating point of the engine 3 is maintained within the monitoring region to circulate the exhaust gas. Failure diagnosis of the device 21 can be performed.

なお、上記したエンジン3の充填効率Ecや回転速度Neに関する例示は一例にすぎず、任意に変更可能であることは言うまでもない。
ところで以上の説明は、故障診断を開始する以前に既に電池受入れ性が低下していた場合であるが、故障診断の開始後に電池受入れ性が低下した場合にも応用できる。例えば、故障診断は開始したが未だインマニ圧の検出を開始していない段階で、電池受入れ性の低下判定が下された場合には、その時点でエンジン3の運転点を充填効率Ec10%まで低下させると共に、モニタ領域の下限を充填効率Ec10%に切り換えればよい。これによりエンジン3の運転点がモニタ領域内に保たれるため、上記と同様に問題なく故障診断が実施することができる。
It goes without saying that the above-mentioned examples of the filling efficiency Ec and the rotation speed Ne of the engine 3 are merely examples and can be arbitrarily changed.
By the way, the above description is the case where the battery acceptability has already deteriorated before the start of the failure diagnosis, but it can also be applied to the case where the battery acceptability has deteriorated after the start of the failure diagnosis. For example, if the failure diagnosis is started but the intake manifold pressure detection is not started yet, and the battery acceptability is judged to be low, the operating point of the engine 3 is lowered to the filling efficiency Ec10% at that time. At the same time, the lower limit of the monitor area may be switched to the filling efficiency Ec10%. As a result, the operating point of the engine 3 is kept within the monitor area, so that the failure diagnosis can be performed without any problem as described above.

また、インマニ圧の検出の開始後に電池受入れ性の低下判定が下された場合には、エンジン3の運転点を充填効率Ec10%まで低下させ、モニタ領域の下限を充填効率Ec10%に切り換えた上で、インマニ圧の検出を最初から実施すればよい。
[第3実施形態]
第2実施形態と同じく本実施形態でもモニタ領域を拡大しているが、その目的は、通常のモニタ領域の下限を下回る充填効率Ec(例えば10%)の運転点をモニタ領域内に含めるためではなく、エンジン3の燃焼を安定化することにより、運転点がモニタ領域を逸脱しているままであっても排ガス循環装置21の故障診断を実施可能とする趣旨である。
If the battery acceptability is determined to decrease after the intake manifold pressure is detected, the operating point of the engine 3 is lowered to a filling efficiency of Ec10%, and the lower limit of the monitor area is switched to a filling efficiency of Ec10%. Then, the intake manifold pressure may be detected from the beginning.
[Third Embodiment]
The monitor area is expanded in the present embodiment as in the second embodiment, but the purpose is to include the operating point of the filling efficiency Ec (for example, 10%) below the lower limit of the normal monitor area in the monitor area. However, by stabilizing the combustion of the engine 3, it is possible to carry out a failure diagnosis of the exhaust gas circulation device 21 even if the operating point remains outside the monitor region.

図5は本実施形態の故障診断の実施状況を示すタイムチャートである。
本実施形態ではエンジン3の燃焼悪化の対策として、エンジン3の目標運転点を回転増加方向、例えば図5中に破線で示すように1500rpmから2000rpmに切り換えると共に(第2の運転点補正手段)、モニタ領域の回転速度Neに関する上限についても1750rpmから2000rpmに拡大する(第2のモニタ領域拡大手段)。結果としてエンジン3は目標運転点2000rpm,10%で運転され、図3のマップから判るように、回転速度Neの増加によりエンジン3の燃焼状態が安定化する。運転点は回転速度Neに関して回転増加方向に拡大されたモニタ領域内にあり、充填効率Ecに関しては、依然としてモニタ領域の下限である15%を下回っている。しかし、燃焼の安定化により故障診断を実施可能な環境が整ったものと見なし、本実施形態では、そのまま排ガス循環装置21の故障診断を開始する。
FIG. 5 is a time chart showing the implementation status of the failure diagnosis of the present embodiment.
In the present embodiment, as a countermeasure against the deterioration of combustion of the engine 3, the target operating point of the engine 3 is switched in the direction of increasing rotation, for example, from 1500 rpm to 2000 rpm as shown by the broken line in FIG. 5 (second operating point correction means). The upper limit of the rotation speed Ne of the monitor area is also expanded from 1750 rpm to 2000 rpm (second monitor area expansion means). As a result, the engine 3 is operated at a target operating point of 2000 rpm and 10%, and as can be seen from the map of FIG. 3, the combustion state of the engine 3 is stabilized by increasing the rotation speed Ne. The operating point is in the monitor region expanded in the direction of increasing rotation with respect to the rotation speed Ne, and the filling efficiency Ec is still below the lower limit of 15% of the monitor region. However, it is considered that the environment in which the failure diagnosis can be performed is prepared by the stabilization of combustion, and in the present embodiment, the failure diagnosis of the exhaust gas circulation device 21 is started as it is.

なお、本来はモニタ領域とエンジン3の運転点との比較に基づき故障診断を開始しているため、第2実施形態と同様にモニタ領域の下限を負荷低下方向に拡大して、運転点がモニタ領域内に保たれていることを確認した上で故障診断を開始してもよい。
そして、このようにエンジン3の回転速度Neが増加すると、図5中に破線で示すように、同一排ガス循環開度であっても通常時に比較して差圧ΔPが縮小傾向になって誤判定し易くなる。そこで、通常時には排ガス循環バルブ23の開度を小開度、例えば図5中に実線で示す20%にとどめ、電池受入れ性の低下時には、破線で示すように排ガス循環バルブ23の開度を40%と増量している。
Since the failure diagnosis is originally started based on the comparison between the monitor area and the operating point of the engine 3, the lower limit of the monitoring area is expanded in the load reduction direction as in the second embodiment, and the operating point is monitored. Failure diagnosis may be started after confirming that the area is kept within the area.
Then, when the rotation speed Ne of the engine 3 increases in this way, as shown by the broken line in FIG. 5, the differential pressure ΔP tends to decrease as compared with the normal time even if the exhaust gas circulation opening degree is the same, resulting in an erroneous determination. It becomes easier to do. Therefore, normally, the opening degree of the exhaust gas circulation valve 23 is limited to a small opening degree, for example, 20% shown by the solid line in FIG. 5, and when the battery acceptability is lowered, the opening degree of the exhaust gas circulation valve 23 is set to 40 as shown by the broken line. The amount has been increased to%.

以上のように本実施形態によれば、故障診断時のモニタ領域を回転増加方向に拡大した上で、エンジン3の目標運転点についても回転増加方向に切り換えることにより、エンジン3の燃焼を安定化した上で排ガス循環装置21の故障診断を実施している。このため、充填効率Ecに関してはモニタ領域を逸脱しているものの、エンジン3が失火を発生し難い高回転域で運転されることから、故障診断により排ガス循環ガスが導入されても失火による燃焼悪化を抑制できる。 As described above, according to the present embodiment, the combustion of the engine 3 is stabilized by expanding the monitoring area at the time of failure diagnosis in the direction of increasing rotation and then switching the target operating point of the engine 3 in the direction of increasing rotation. After that, the failure diagnosis of the exhaust gas circulation device 21 is carried out. Therefore, although the filling efficiency Ec deviates from the monitoring area, since the engine 3 is operated in a high rotation range where misfire is unlikely to occur, combustion deterioration due to misfire even if exhaust gas circulating gas is introduced by failure diagnosis. Can be suppressed.

さらに、エンジン3の回転増加に起因する差圧ΔPの縮小を防止すべく、通常時に比較して排ガス循環バルブ23の開度を拡大しているため、通常時と同様の故障判定値に基づき排ガス循環装置21の正常・異常を的確に判定できる。結果として本実施形態によれば、走行バッテリ15の電池受入れ性の低下時においても、目標充電電力の制限により走行バッテリ15を保護しつつ、排ガス循環装置21の故障診断を実施することができる。 Further, since the opening degree of the exhaust gas circulation valve 23 is expanded as compared with the normal time in order to prevent the differential pressure ΔP from being reduced due to the increase in the rotation of the engine 3, the exhaust gas is exhaust gas based on the same failure determination value as in the normal time. The normality / abnormality of the circulation device 21 can be accurately determined. As a result, according to the present embodiment, even when the battery acceptability of the traveling battery 15 is lowered, the failure diagnosis of the exhaust gas circulation device 21 can be performed while protecting the traveling battery 15 by limiting the target charging power.

なお本実施形態では、通常時と電池受入れ性の低下時との差圧ΔPの格差を解消すべく排ガス循環開度を変更したが、これに代えて、電池受入れ性の低下時には通常時よりも故障判定値として小さな値を適用してもよい。
また、上記したエンジン3の充填効率Ecや回転速度Neに関する例示は一例にすぎず、任意に変更可能であり、さらに第2実施形態で述べたように、以上の本実施形態の制御を、故障診断の開始後に電池受入れ性が低下した場合に応用してもよい。
In the present embodiment, the exhaust gas circulation opening is changed in order to eliminate the difference in the differential pressure ΔP between the normal time and the time when the battery acceptability is lowered, but instead, the exhaust gas circulation opening is changed when the battery acceptability is lowered as compared with the normal time. A small value may be applied as the failure determination value.
Further, the above-mentioned examples of the filling efficiency Ec and the rotation speed Ne of the engine 3 are merely examples, and can be arbitrarily changed. Further, as described in the second embodiment, the control of the present embodiment may be out of order. It may be applied when the battery acceptability deteriorates after the start of the diagnosis.

ところで、以上のように各実施形態では、排ガス循環装置21の故障診断を実施する際に、電池受入れ性の低下判定に基づきエンジン3の運転点を負荷低下方向に切り換えるとモニタ領域を逸脱するか否かを判定している(領域逸脱判定手段)。そして、モニタ領域から逸脱すると判定した場合に、第1実施形態では、エンジン3の運転点を切り換えてモニタ領域内に保ち(第1の運転点補正手段、第2実施形態では、モニタ領域を負荷低下方向に拡大して、エンジン3の運転点を切り換えることなくモニタ領域内に保ち(第1のモニタ領域拡大手段)、第3実施形態では、モニタ領域を回転増加方向に拡大すると共にエンジン3の運転点を回転増加方向に切り換えている(第2のモニタ領域拡大手段)。 By the way, as described above, in each embodiment, when the failure diagnosis of the exhaust gas circulation device 21 is performed, if the operating point of the engine 3 is switched in the load reduction direction based on the determination of the decrease in battery acceptability, does the monitor region deviate? Whether or not it is determined (area deviation determination means). Then, when it is determined that the monitor region deviates from the monitor region, the operating point of the engine 3 is switched and kept within the monitor region in the first embodiment (the first operating point correction means, in the second embodiment, the monitor region is loaded. It expands in the downward direction and is kept in the monitor area without switching the operating point of the engine 3 (first monitor area expansion means), and in the third embodiment, the monitor area is expanded in the rotation increasing direction and the engine 3 The operating point is switched in the direction of increasing rotation (second monitor area expanding means).

これらの各手法には長所短所があるため、互いを組み合わせて利用することが考えられる。
即ち、第1実施形態の手法は、安定した燃焼が望める本来のモニタ領域内でエンジン3を運転させながら故障診断を実施することから、診断精度が最も高い。その反面、モニタ領域内の特性線と切換前のエンジン3の運転点との関係によっては、回転速度を低下させても運転点をモニタ領域内に保てない場合も生じる。
Since each of these methods has advantages and disadvantages, it is conceivable to use them in combination with each other.
That is, the method of the first embodiment has the highest diagnostic accuracy because the failure diagnosis is performed while operating the engine 3 within the original monitor region where stable combustion can be expected. On the other hand, depending on the relationship between the characteristic line in the monitor area and the operating point of the engine 3 before switching, the operating point may not be kept in the monitor area even if the rotation speed is reduced.

第2実施形態の手法は、運転点をモニタ領域内に保つことに関しては第1実施形態よりも確実である。その反面、エンジン3の運転点が充填効率Ecに関して大きく低下している場合には、その運転点で故障診断を実施することから、排ガス循環バルブ23の開度を縮小する対策を講じたとしても燃焼悪化が避けられず、この要因により第1実施形態に比較して診断精度が劣る。 The method of the second embodiment is more reliable than the first embodiment in keeping the operating point within the monitor area. On the other hand, if the operating point of the engine 3 is significantly lowered with respect to the filling efficiency Ec, a failure diagnosis is performed at that operating point, so even if measures are taken to reduce the opening degree of the exhaust gas circulation valve 23. Deterioration of combustion is unavoidable, and due to this factor, the diagnostic accuracy is inferior to that of the first embodiment.

第3実施形態の手法は、エンジン3の回転増加により燃焼安定性を図っているものの、第2実施形態と同様に、充填効率Ecの低い運転点で故障診断を実施することから燃焼悪化が避けられない。さらに、故障診断の度にエンジン回転が高められて騒音及び振動が増加するため、良好なNVH性能が得られずに運転者に違和感を与える要因にもなり得る。
よって、実施が望ましい順位としては、第1、第2、第3実施形態の順と判断できる。そこで、例えば第1実施形態の手法でエンジン3の運転点をモニタ領域内に保てる場合には、第1実施形態の手法により故障診断を実施し、第1実施形態の手法ではエンジン3の運転点をモニタ領域内に保てない場合には、第2実施形態の手法または第3実施形態の手法により故障診断を実施するようにしてもよい(対応切換手段)。
Although the method of the third embodiment aims at combustion stability by increasing the rotation of the engine 3, combustion deterioration is avoided because the failure diagnosis is performed at the operating point where the filling efficiency Ec is low as in the second embodiment. I can't. Further, since the engine rotation is increased and noise and vibration are increased every time a failure diagnosis is made, good NVH performance cannot be obtained, which may cause a sense of discomfort to the driver.
Therefore, it can be determined that the order in which the implementation is desirable is the order of the first, second, and third embodiments. Therefore, for example, when the operating point of the engine 3 can be kept within the monitor area by the method of the first embodiment, the failure diagnosis is performed by the method of the first embodiment, and the operating point of the engine 3 is carried out by the method of the first embodiment. If the above is not kept in the monitor area, the failure diagnosis may be performed by the method of the second embodiment or the method of the third embodiment (corresponding switching means).

このように各手法を適宜切り換えるようにすれば、まず第1実施形態の手法が優先して実施されることから高い診断精度が得られ、且つ第1実施形態の手法が実施不能な場合であっても、第2実施形態または第3実施形態の手法を実施可能なため、これにより電池受入れ性の低下時であっても故障診断を実施することができる。
以上で実施形態の説明を終えるが、本発明の態様はこの実施形態に限定されるものではない。例えば上記実施形態では、走行モードをEVモード、シリーズモード、パラレルモードの間で切換可能なプラグインハイブリッド車両1の排ガス循環故障診断装置に具体化したが、車両1の種別はこれに限るものではない。エンジンにより発電機を駆動して発電電力を走行バッテリに充電するシリーズモードを実行可能なハイブリッド車両であれば任意に適用可能である。
If each method is appropriately switched in this way, the method of the first embodiment is first implemented with priority, so that high diagnostic accuracy can be obtained, and the method of the first embodiment cannot be implemented. However, since the method of the second embodiment or the third embodiment can be implemented, it is possible to carry out the failure diagnosis even when the battery acceptability is lowered.
Although the description of the embodiment is completed above, the aspect of the present invention is not limited to this embodiment. For example, in the above embodiment, the driving mode is embodied in the exhaust gas circulation failure diagnosis device of the plug-in hybrid vehicle 1 that can switch between the EV mode, the series mode, and the parallel mode, but the type of the vehicle 1 is not limited to this. Absent. It can be arbitrarily applied as long as it is a hybrid vehicle capable of executing a series mode in which a generator is driven by an engine and the generated power is charged to a traveling battery.

1 車両
3 エンジン
10 モータジェネレータ(発電機)
15 走行バッテリ
18 ハイブリッドコントローラ(制御手段、排ガス循環バルブ拡大手段、排ガス循環手段、充電制御手段、電池受入れ性判定手段、充電電力制限手段、排ガス循環故障診断手段、第1,2の運転点補正手段、第1,2のモニタ領域拡大手段、領域逸脱判定手段、対応切換手段)
21 排ガス循環装置(排ガス循環手段)
22 排ガス循環通路
23 排ガス循環バルブ
24 エキゾーストマニホールド(排気側)
25 インテークマニホールド(吸気側)
26 圧力センサ(排ガス循環故障診断手段)
1 vehicle 3 engine 10 motor generator (generator)
15 Running battery 18 Hybrid controller (control means, exhaust gas circulation valve expansion means, exhaust gas circulation means, charge control means, battery acceptability determination means, charging power limiting means, exhaust gas circulation failure diagnosis means, first and second operating point correction means , 1st and 2nd monitor area expansion means, area deviation determination means, corresponding switching means)
21 Exhaust gas circulation device (exhaust gas circulation means)
22 Exhaust gas circulation passage 23 Exhaust gas circulation valve 24 Exhaust manifold (exhaust side)
25 Intake manifold (intake side)
26 Pressure sensor (exhaust gas circulation failure diagnosis means)

Claims (6)

エンジンを所定の運転点で運転して発電機を駆動し、該発電機により発電された電力をバッテリに充電する充電制御手段と、
前記バッテリへの充電電力を制限すべき電池受入れ性の低下時か否かを判定する電池受入れ性判定手段と、
前記電池受入れ性判定手段により電池受入れ性の低下時と判定されたときに、前記バッテリへの充電電力を制限すべく前記エンジンの運転点を負荷低下方向に切り換え、発電電力を低下させる充電電力制限手段と、
前記エンジンの排ガスを循環させる排ガス循環手段と、
前記排ガス循環手段の故障診断の実施条件が成立したときに、前記エンジンの運転点を負荷と回転速度で規定されるモニタ領域内で前記排ガス循環手段の故障診断を実施する排ガス循環故障診断手段と、
前記排ガス循環故障診断手段により前記排ガス循環手段の故障判定が実施される際に、前記電池受入れ性判定手段の判定に基づき前記エンジンの運転点が負荷低下方向に切り換えられると前記モニタ領域を逸脱する場合に、前記エンジンの運転領域の変更又は前記モニタ領域を拡大する制御手段と、
前記モニタ領域を負荷低下方向に拡大して前記運転点を前記拡大されたモニタ領域内に保つ第1のモニタ領域拡大手段とを備え、
前記第1のモニタ領域拡大手段による前記モニタ領域の拡大時には、通常時に比較して排ガス循環バルブの開弁時の開度を縮小する
ことを特徴とするハイブリッド車両の排ガス循環故障診断装置。
A charge control means that operates an engine at a predetermined operating point to drive a generator and charges a battery with the electric power generated by the generator.
A battery acceptability determining means for determining whether or not the battery acceptability for which the charging power to the battery should be limited is deteriorated, and
When the battery acceptability determination means determines that the battery acceptability is low, the charging power limit that reduces the generated power by switching the operating point of the engine in the load reduction direction in order to limit the charging power to the battery. Means and
Exhaust gas circulation means for circulating the exhaust gas of the engine and
When the conditions for performing the failure diagnosis of the exhaust gas circulation means are satisfied, the exhaust gas circulation failure diagnosis means for carrying out the failure diagnosis of the exhaust gas circulation means within the monitoring region defined by the load and the rotation speed of the operating point of the engine. ,
When the failure determination of the exhaust gas circulation failure means is performed by the exhaust gas circulation failure diagnosis means, if the operating point of the engine is switched in the load reduction direction based on the determination of the battery acceptability determination means, the monitor region is deviated. In some cases, a control means for changing the operating area of the engine or expanding the monitoring area, and
A first monitor area expanding means for expanding the monitor area in the load reduction direction and keeping the operating point within the expanded monitor area is provided.
Wherein at the time of expansion of the monitoring area of the first monitor area enlargement means it is usually exhaust gas circulation failure diagnosis apparatus for a hybrid vehicle, characterized in that to reduce the opening at the valve opening of the exhaust gas circulation valve in comparison with the time.
前記排ガス循環故障診断装置は、前記モニタ領域の拡大時に、通常時に比較して前記排ガス循環バルブの開弁時の開度を縮小すると共に、前記吸気側の圧力変化を判定する故障判定値として小さな値を適用する
ことを特徴とする請求項1に記載のハイブリッド車両の排ガス循環故障診断装置。
The exhaust gas circulation failure diagnosis device reduces the opening degree of the exhaust gas circulation valve when the valve is opened when the monitoring area is expanded, and is small as a failure determination value for determining a pressure change on the intake side. The exhaust gas circulation failure diagnosis device for a hybrid vehicle according to claim 1, wherein a value is applied.
前記排ガス循環故障診断装置は、前記モニタ領域を回転増加方向に拡大する第2のモニタ領域拡大手段と、
前記第2のモニタ領域拡大手段による前記モニタ領域の拡大時に、前記エンジンの運転点を回転増加方向に切り換える第2の運転点補正手段と
を有することを特徴とする請求項1または2に記載のハイブリッド車両の排ガス循環故障診断装置。
The exhaust gas circulation failure diagnosis device includes a second monitor area expanding means for expanding the monitor area in the direction of increasing rotation.
The first or second claim, wherein the second operating point correction means for switching the operating point of the engine in the rotation increasing direction when the monitoring area is expanded by the second monitoring area expanding means is provided. Exhaust gas circulation failure diagnosis device for hybrid vehicles.
前記排ガス循環故障診断装置は、前記第2の運転点補正手段による前記運転点の切換時に、通常時に比較して前記排ガス循環バルブの開弁時の開度を拡大する排ガス循環バルブ拡大手段を有する
ことを特徴とする請求項3に記載のハイブリッド車両の排ガス循環故障診断装置。
The exhaust gas circulation failure diagnosis device includes an exhaust gas circulation valve expanding means for expanding the opening degree of the exhaust gas circulation valve when the valve is opened as compared with a normal time when the operating point is switched by the second operating point correcting means. The exhaust gas circulation failure diagnosis device for a hybrid vehicle according to claim 3, wherein the exhaust gas circulation failure diagnosis device is characterized.
前記排ガス循環故障診断装置は、前記エンジンの負荷を保ちつつ該エンジンの回転速度を低下させて、前記充電電力を制限しながら前記運転点を前記モニタ領域内に保つ第1の運転点補正手段を有する
ことを特徴とする請求項1から4のいずれか1項に記載のハイブリッド車両の排ガス循環故障診断装置。
The exhaust gas circulation failure diagnosis device provides a first operating point correction means that reduces the rotational speed of the engine while maintaining the load of the engine and keeps the operating point within the monitoring region while limiting the charging power. The exhaust gas circulation failure diagnosis device for a hybrid vehicle according to any one of claims 1 to 4, wherein the device is provided.
前記排ガス循環故障診断装置は、前記第1の運転点補正手段により前記エンジンの運転点を前記モニタ領域内に保てる場合には該第1の運転点補正手段に処理を実行させ、前記第1の運転点補正手段により前記運転点をモニタ領域内に保てない場合には、前記第1のモニタ領域拡大手段または前記第2のモニタ領域拡大手段に処理を実行させる対応切換手段を有する
ことを特徴とする請求項3から5のいずれか1項に記載のハイブリッド車両の排ガス循環故障診断装置。
When the operating point of the engine can be kept within the monitoring region by the first operating point correcting means, the exhaust gas circulation failure diagnosis device causes the first operating point correcting means to execute the process, and the first operating point correcting means. When the operating point cannot be kept within the monitor area by the operating point correcting means, the first monitoring area expanding means or the second monitoring area expanding means has a corresponding switching means for executing the process. The exhaust gas circulation failure diagnosis device for a hybrid vehicle according to any one of claims 3 to 5.
JP2016055724A 2016-03-18 2016-03-18 Exhaust gas circulation failure diagnostic device for hybrid vehicles Active JP6774003B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016055724A JP6774003B2 (en) 2016-03-18 2016-03-18 Exhaust gas circulation failure diagnostic device for hybrid vehicles

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016055724A JP6774003B2 (en) 2016-03-18 2016-03-18 Exhaust gas circulation failure diagnostic device for hybrid vehicles

Publications (2)

Publication Number Publication Date
JP2017170927A JP2017170927A (en) 2017-09-28
JP6774003B2 true JP6774003B2 (en) 2020-10-21

Family

ID=59971570

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016055724A Active JP6774003B2 (en) 2016-03-18 2016-03-18 Exhaust gas circulation failure diagnostic device for hybrid vehicles

Country Status (1)

Country Link
JP (1) JP6774003B2 (en)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3784747B2 (en) * 2002-05-17 2006-06-14 本田技研工業株式会社 Evaporative fuel treatment system leak diagnosis device
JP4958752B2 (en) * 2007-12-06 2012-06-20 日立オートモティブシステムズ株式会社 Diagnostic control device for vehicle
JP5182018B2 (en) * 2008-10-31 2013-04-10 日産自動車株式会社 Sensor abnormality diagnosis device and sensor abnormality diagnosis method
JP5445347B2 (en) * 2010-06-22 2014-03-19 トヨタ自動車株式会社 VEHICLE CONTROL DEVICE, VEHICLE HAVING THE SAME, AND INTERNAL COMBUSTION ENGINE FAILURE JUDGING METHOD
JP5913892B2 (en) * 2011-10-04 2016-04-27 三菱自動車工業株式会社 Fault diagnosis method for exhaust gas recirculation device of hybrid vehicle and internal combustion engine
JP5734339B2 (en) * 2013-05-07 2015-06-17 三菱電機株式会社 Series hybrid vehicle
CN106794835B (en) * 2014-09-04 2019-06-18 三菱自动车工业株式会社 Equipped with the vehicle of internal combustion engine

Also Published As

Publication number Publication date
JP2017170927A (en) 2017-09-28

Similar Documents

Publication Publication Date Title
EP1247687B1 (en) Control apparatus for electric motor and control apparatus for hybrid vehicle
US20180216552A1 (en) Hybrid vehicle
CN107269403B (en) Vehicle control device
US7019472B2 (en) Vehicle controller that stably supplies power to a battery and method thereof
US9988042B2 (en) Hybrid vehicle
US10800399B2 (en) Hybrid vehicle
JP5554391B2 (en) Control device for hybrid vehicle with exhaust gas generator and control method for hybrid vehicle with exhaust gas generator
JP6950601B2 (en) Hybrid vehicle control device
JP5406270B2 (en) Method and apparatus for driving hybrid vehicle with electric supercharger
GB2406179A (en) A method for controlling the heating of a battery in a hybrid electric vehicle
JP2021155005A (en) Hybrid vehicle
CN112590753B (en) Control device and control method for hybrid vehicle
JP6730663B2 (en) Exhaust gas circulation failure diagnosis device for hybrid vehicles
WO2017135307A1 (en) Vehicle air-conditioning apparatus
JP2007030869A (en) Method for controlling engine in vehicle
US10926755B2 (en) Hybrid vehicle
US9758154B2 (en) Hybrid vehicle
JP4086053B2 (en) Control device for hybrid vehicle
JP5212749B2 (en) Control device and control method for hybrid vehicle
JP6774003B2 (en) Exhaust gas circulation failure diagnostic device for hybrid vehicles
JP6774002B2 (en) Hybrid vehicle failure diagnostic device
KR101905569B1 (en) Method and appratus for controlling mhsg of mild hybrid electric vehicle
JP6003220B2 (en) Exhaust gas purification method and apparatus for internal combustion engine
JP2013230718A (en) Exhaust gas purification device and control method of internal combustion engine
CN111824120B (en) Hybrid vehicle and method of controlling hybrid vehicle

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20181221

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20200205

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20200403

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20200610

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20200804

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: 20200902

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20200915

R151 Written notification of patent or utility model registration

Ref document number: 6774003

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151