JPH109073A - Property learning device for fuel pressure sensor - Google Patents
Property learning device for fuel pressure sensorInfo
- Publication number
- JPH109073A JPH109073A JP8166161A JP16616196A JPH109073A JP H109073 A JPH109073 A JP H109073A JP 8166161 A JP8166161 A JP 8166161A JP 16616196 A JP16616196 A JP 16616196A JP H109073 A JPH109073 A JP H109073A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- fuel
- low
- pump
- fuel pump
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Measuring Fluid Pressure (AREA)
- Fuel-Injection Apparatus (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、高圧燃料ポンプで
吐出された燃料を燃焼室に直接噴射する火花点火直噴式
機関等において始動時に燃料噴射量を補正するため、高
圧用燃料ポンプの吐出圧を検出する燃圧センサの検出精
度を補償するための技術に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge pressure of a high pressure fuel pump for correcting a fuel injection amount at the time of starting in a spark ignition direct injection type engine or the like in which fuel discharged by a high pressure fuel pump is directly injected into a combustion chamber. TECHNICAL FIELD The present invention relates to a technique for compensating detection accuracy of a fuel pressure sensor that detects a pressure.
【0002】[0002]
【従来の技術】近年、ガソリン機関等の火花点火式機関
においても、燃料噴射弁の噴孔を燃焼室内に臨ませて設
置し、該燃料噴射弁によって燃料を燃焼室内に直接噴射
する方式が研究されており、該火花点火式直噴内燃機関
によれば、吸気ポートに燃料噴射弁を備えた予混合式の
火花点火機関に比較して、燃料の輸送遅れによる過渡運
転特性の悪化や排気組成の悪化を抑制できるという利点
がある。2. Description of the Related Art In recent years, in a spark ignition type engine such as a gasoline engine, research has been conducted on a system in which an injection hole of a fuel injection valve is installed facing a combustion chamber and fuel is directly injected into the combustion chamber by the fuel injection valve. According to the spark ignition type direct injection internal combustion engine, compared to a premixed spark ignition engine having a fuel injection valve at an intake port, the transient operation characteristics are deteriorated due to fuel transport delay and the exhaust gas composition is reduced. There is an advantage that the deterioration of can be suppressed.
【0003】この種の機関では、燃料の微粒化効果を高
めるため燃料噴射圧力を高める方法として、燃料供給通
路の途中に高圧用の燃料ポンプを備えている (特開平5
−321783号等参照) 。In this type of engine, a high-pressure fuel pump is provided in the middle of a fuel supply passage as a method for increasing the fuel injection pressure in order to enhance the atomization effect of the fuel (Japanese Patent Laid-Open No. Hei 5 (1993)).
-321783 etc.).
【0004】[0004]
【発明が解決しようとする課題】ところで、前記内燃機
関の高圧用燃料ポンプでは、始動時に燃料圧力がプレッ
シャレギュレータで調整される圧力まで上昇せず、該調
整圧力に応じた燃料噴射量制御では燃料噴射量が不足す
る。このため、燃圧センサにより燃料圧力を検出して燃
料圧力によって燃料噴射弁の噴射時間 (パルス幅) を補
正することにより燃料噴射量を制御することが考えられ
ている。In the high-pressure fuel pump of the internal combustion engine, the fuel pressure does not increase to the pressure adjusted by the pressure regulator at the time of starting, and the fuel injection amount control according to the adjusted pressure does not increase the fuel pressure. Insufficient injection volume. For this reason, it has been considered to control the fuel injection amount by detecting the fuel pressure with a fuel pressure sensor and correcting the injection time (pulse width) of the fuel injection valve with the fuel pressure.
【0005】しかしながら、始動時の燃料圧力が低い領
域は、元々燃圧センサの精度が悪い領域であるので、該
燃圧センサの検出値に基づく燃料噴射量補正では、精度
が得られないという問題がある。即ち、燃圧センサはフ
ルスケール誤差 (オフセット誤差) を一般に持つため、
図4に示すように、低圧力側程誤差が増す。例えば、前
記高圧レギュレータ16で規制される圧力値5MPaで±
3%の誤差が、始動直後等の低圧レギュレータ13で規制
される低圧の0.3 MPaでは±30%の誤差となってしま
う。However, the region where the fuel pressure at the time of starting is low is a region where the accuracy of the fuel pressure sensor is originally poor, so that there is a problem that the accuracy cannot be obtained by correcting the fuel injection amount based on the detection value of the fuel pressure sensor. . That is, since a fuel pressure sensor generally has a full-scale error (offset error),
As shown in FIG. 4, the error increases as the pressure decreases. For example, when the pressure value regulated by the high pressure regulator 16 is 5 MPa,
An error of 3% results in an error of ± 30% at a low pressure of 0.3 MPa regulated by the low-pressure regulator 13 immediately after starting or the like.
【0006】直噴機関等の高圧ポンプの吐出圧は、ポン
プ回転速度が十分上昇 (300 〜500rpm以上) になれ
ば、プレッシャレギュレータで定まる上限圧 (5〜8M
Pa) に上昇するので、燃料圧力はプレッシャレギュレ
ータにより高精度に定まるが、既述したように始動時等
の回転しはじめは、プレッシャレギュレータの上限圧ま
で上昇しないので、上記補正を燃圧センサの検出値を用
いて行おうとすると、上記の誤差の影響を強く受け精度
が出ない。また、低圧でも高い精度が得られるような燃
圧センサを使用するとコスト高につく。[0006] The discharge pressure of a high-pressure pump such as a direct injection engine, when the pump rotation speed is sufficiently increased (300 to 500 rpm or more), is determined by an upper limit pressure (5 to 8M) determined by a pressure regulator.
(Pa), the fuel pressure is determined with high accuracy by the pressure regulator. However, as described above, the fuel pressure does not increase to the upper limit pressure of the pressure regulator at the start of rotation at the time of starting, etc. If an attempt is made to use the values, the accuracy is not obtained because of the influence of the above error. Further, if a fuel pressure sensor that can obtain high accuracy even at a low pressure is used, the cost increases.
【0007】本発明は、このような従来の問題点に鑑み
なされたもので、プレッシャレギュレータを利用した学
習を行って燃圧センサの精度を補償することにより、初
期性能がそれほど高精度でない低コストの燃圧センサを
用いても十分高精度に燃圧を検出することができるよう
にすることを目的とする。また、前記燃圧センサの精度
を補償することにより、始動時の燃料噴射量補正精度を
高めて、始動性能を改善することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem. By learning using a pressure regulator to compensate for the accuracy of a fuel pressure sensor, the initial performance is not so high and the cost is low. It is an object of the present invention to enable a fuel pressure to be detected with sufficiently high accuracy even when a fuel pressure sensor is used. It is another object of the present invention to improve the starting performance by compensating the accuracy of the fuel pressure sensor to increase the accuracy of correcting the fuel injection amount at the time of starting.
【0008】[0008]
【課題を解決するための手段】このため、請求項1に係
る発明は図1に示すように、相対的に低圧で燃料を吐出
する低圧用燃料ポンプと、該低圧用燃料ポンプから吐出
された燃料を吸入して相対的に高圧で吐出する高圧用燃
料ポンプと、前記低圧用燃料ポンプからの吐出燃圧が十
分上昇したときの燃圧を低圧用設定値に調整する低圧用
レギュレータと、前記高圧用燃料ポンプからの吐出燃圧
が十分上昇したときの燃圧を高圧用設定値に調整する高
圧用レギュレータと、該高圧用レギュレータで燃圧を調
整された燃料を燃料噴射弁によって機関に供給する一
方、前記高圧用燃料ポンプから吐出される燃圧を検出す
る燃圧センサを備え、前記高圧用燃料ポンプの上昇中の
吐出燃圧を検出し、該検出された燃圧に基づいて燃料噴
射量を補正する燃料噴射量補正手段を備えた内燃機関の
燃料系において、前記低圧用燃料ポンプの吐出圧が十分
上昇し、かつ、前記高圧用燃料ポンプが実質的に非駆動
状態であるときに前記燃圧センサの検出値を前記低圧用
レギュレータで調整される低圧用設定値と対応させ、前
記高圧用燃料ポンプの吐出圧が十分上昇したときの前記
燃圧センサの検出値を前記高圧用レギュレータで調整さ
れる高圧用設定値と対応させる学習を行い、該2点の学
習された検出値と各設定値とに基づいて、該燃圧センサ
の検出値と実際の燃圧との関係を学習するセンサ特性学
習手段を設けたことを特徴とする。Therefore, according to the first aspect of the present invention, as shown in FIG. 1, a low-pressure fuel pump for discharging fuel at a relatively low pressure and a low-pressure fuel pump discharged from the low-pressure fuel pump are provided. A high-pressure fuel pump that draws in fuel and discharges the fuel at a relatively high pressure; a low-pressure regulator that adjusts the fuel pressure when the discharge fuel pressure from the low-pressure fuel pump is sufficiently increased to a low-pressure set value; A high-pressure regulator that adjusts the fuel pressure when the fuel pressure discharged from the fuel pump is sufficiently increased to a high-pressure set value, and supplies fuel whose fuel pressure has been adjusted by the high-pressure regulator to the engine by a fuel injection valve, A fuel pressure sensor for detecting a fuel pressure discharged from the fuel pump for fuel, a fuel pressure sensor for detecting a rising fuel pressure of the high-pressure fuel pump, and correcting a fuel injection amount based on the detected fuel pressure. In the fuel system of the internal combustion engine provided with the injection amount correcting means, when the discharge pressure of the low-pressure fuel pump is sufficiently increased and the high-pressure fuel pump is substantially in a non-driving state, the detection of the fuel pressure sensor is performed. A value corresponding to a low pressure set value adjusted by the low pressure regulator, and a detection value of the fuel pressure sensor when the discharge pressure of the high pressure fuel pump is sufficiently increased is set to a high pressure adjusted by the high pressure regulator. A sensor characteristic learning means for performing learning corresponding to the values and learning the relationship between the detected value of the fuel pressure sensor and the actual fuel pressure based on the two detected values and the set values. It is characterized by.
【0009】(作用・効果)機関の始動後、低圧用燃料ポ
ンプの吐出圧が十分上昇して低圧用レギュレータで調整
される低圧用設定値に達するが、まだ、高圧用燃料ポン
プが実質的に非駆動状態であるときは、燃圧は低圧用レ
ギュレータによって低圧用設定値に調整された状態とな
っている。(Operation / Effect) After the engine is started, the discharge pressure of the low-pressure fuel pump rises sufficiently to reach the low-pressure set value adjusted by the low-pressure regulator. When in the non-drive state, the fuel pressure is adjusted to a low pressure set value by the low pressure regulator.
【0010】そこで、前記の状態で前記燃圧センサで検
出された値を、前記調整された低圧用設定値と対応させ
る学習を行う。また、高圧用燃料ポンプの吐出圧が十分
に上昇した後は、燃圧は高圧用レギュレータにより高圧
用設定値に調整される。そこで、前記の状態で前記燃圧
センサの検出値された値を、前記調整された高圧用設定
値と対応させる学習を行う。Therefore, learning is performed to make the value detected by the fuel pressure sensor in the above state correspond to the adjusted set value for low pressure. After the discharge pressure of the high-pressure fuel pump has sufficiently increased, the fuel pressure is adjusted to a high-pressure set value by the high-pressure regulator. Therefore, learning is performed to make the value detected by the fuel pressure sensor correspond to the adjusted set value for high pressure in the above state.
【0011】前記燃圧センサの特性バラツキはオフセッ
トエラーが主であり、リニアリティは極めて良好である
ので、前記2点における燃圧センサの学習された検出値
と設定値とに基づいて、燃圧センサの検出値と実際の燃
圧との関係を学習することができ、該学習された燃圧セ
ンサの特性に基づいて燃圧を精度良く検出することがで
き、ひいては燃料噴射量の補正精度向上による始動性能
を改善することができる。Since the characteristic variation of the fuel pressure sensor is mainly due to an offset error and the linearity is extremely good, the detected value of the fuel pressure sensor is determined based on the learned value and the set value of the fuel pressure sensor at the two points. And the actual fuel pressure can be learned, the fuel pressure can be accurately detected based on the learned characteristics of the fuel pressure sensor, and the starting performance can be improved by improving the correction accuracy of the fuel injection amount. Can be.
【0012】また、請求項2に係る発明は、前記低圧用
燃料ポンプは電動式であり、前記高圧用燃料ポンプは機
関駆動されることを特徴とする。 (作用・効果)低圧用燃料ポンプは電動式であるので、O
N操作後吐出圧が速やかに上昇する特性を有するが、車
両用等では大きな電力を確保することが難しいので最大
吐出圧の低い低圧用燃料ポンプとして用いる。Further, the invention according to claim 2 is characterized in that the low-pressure fuel pump is electrically driven, and the high-pressure fuel pump is driven by an engine. (Operation / Effect) Since the low-pressure fuel pump is electrically driven,
It has the characteristic that the discharge pressure rises quickly after the N operation, but it is difficult to secure large electric power for vehicles and the like, so it is used as a low-pressure fuel pump with a low maximum discharge pressure.
【0013】一方、高圧用燃料ポンプは機関駆動式であ
るので、機関始動後、吐出圧の上昇の遅れが大きいが、
大きな最大吐出圧が得られるので高圧用燃料ポンプとし
て用いる。また、請求項3に係る発明は、前記前記燃圧
センサの検出値を前記低圧用レギュレータで調整される
低圧用設定値と対応させる条件は、前記電動式の低圧用
燃料ポンプがON状態で、かつ、機関回転速度が所定未
満の低速状態であることを特徴とする。On the other hand, since the high-pressure fuel pump is of an engine driven type, there is a large delay in increasing the discharge pressure after the engine is started.
Used as a high-pressure fuel pump because a large maximum discharge pressure can be obtained. In the invention according to claim 3, the condition for making the detection value of the fuel pressure sensor correspond to a low pressure set value adjusted by the low pressure regulator is such that the electric low pressure fuel pump is in an ON state, and The engine speed is lower than a predetermined low speed.
【0014】(作用・効果)前記したように電動式の低圧
用燃料ポンプはON操作後、吐出圧が速やかに上昇し、
機関駆動式の高圧用燃料ポンプは機関回転速度が低速の
ときは吐出圧が上がらないので、燃圧が低圧用設定値に
規制されている状態となっている。そこで、この状態の
ときに、燃圧センサの検出値を低圧用設定値と対応させ
る学習を行うことで、低圧側の精度が確保される。(Operation / Effect) As described above, after the ON operation of the electric low-pressure fuel pump, the discharge pressure rapidly increases,
Since the discharge pressure of the engine-driven high-pressure fuel pump does not increase when the engine speed is low, the fuel pressure is regulated to the low-pressure set value. Therefore, in this state, the accuracy on the low pressure side is ensured by performing learning to make the detection value of the fuel pressure sensor correspond to the set value for low pressure.
【0015】また、請求項4に係る発明は、前記燃料噴
射弁は、燃料を火花点火式機関の燃焼室に直接噴射する
ことを特徴とする。 (作用・効果)既述したように燃焼室に直接燃料噴射する
機関では、燃料噴射圧力を十分高圧にする必要があり、
これに応じて高圧用燃料ポンプの吐出圧を十分大きくす
る必要があるため、吐出圧の上昇遅れが長引く傾向とな
り、燃圧センサの検出精度を高めることによる始動時の
燃料噴射量の補正精度向上の効果が大きく、ひいては始
動性の改善効果が高い。Further, the invention according to claim 4 is characterized in that the fuel injection valve directly injects fuel into a combustion chamber of a spark ignition type engine. (Operation / Effect) As described above, in an engine that directly injects fuel into the combustion chamber, the fuel injection pressure must be sufficiently high.
Accordingly, it is necessary to sufficiently increase the discharge pressure of the high-pressure fuel pump, so that a delay in the rise of the discharge pressure tends to be prolonged. The effect is great, and the effect of improving startability is high.
【0016】[0016]
【発明の実施の形態】以下に、本発明の実施の形態を図
に基づいて説明する。図2は、本発明の一実施形態の全
体システム構成を示す。図2において、機関1は、電磁
式の燃料噴射弁2を、その噴孔を燃焼室3内に臨ませて
配置し、吸気ポート4及び吸気弁5を介して燃焼室3内
に吸引した新気に対して前記燃料噴射弁2から燃料を噴
射して混合気を形成させ、該混合気を点火栓6による火
花点火によって着火させる火花点火式直噴機関である。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an overall system configuration according to an embodiment of the present invention. In FIG. 2, an engine 1 has an electromagnetic fuel injection valve 2 arranged with its injection hole facing the combustion chamber 3, and suctioned into the combustion chamber 3 via an intake port 4 and an intake valve 5. This is a spark-ignition direct-injection engine in which fuel is injected from the fuel injection valve 2 to form air-fuel mixture, and the air-fuel mixture is ignited by spark ignition by a spark plug 6.
【0017】前記機関1の排気は、排気弁7及び排気ポ
ート8を介して燃料室3から排出され、図示しない排気
浄化触媒及びマフラーを介して大気中に放出される。燃
料タンク9内の燃料は、電動式の低圧用燃料ポンプ10に
より相対的に低圧で燃料が吐出され、低圧側燃料通路11
Aに介装されたフィルタ12によってろ過された後、フィ
ルタ12下流側の低圧側燃料通路11Bにバイパスして設け
られた低圧用レギュレータ13により燃圧を一定の低圧用
設定値例えば0.3 MPaに調整された燃料が高圧用の高
圧用燃料ポンプ14に送られる。The exhaust gas of the engine 1 is discharged from the fuel chamber 3 through an exhaust valve 7 and an exhaust port 8, and is discharged into the atmosphere through an exhaust purification catalyst and a muffler (not shown). The fuel in the fuel tank 9 is discharged at a relatively low pressure by an electric low-pressure fuel pump 10 and the low-pressure side fuel passage 11
After being filtered by the filter 12 interposed in A, the fuel pressure is adjusted to a constant low-pressure set value, for example, 0.3 MPa by a low-pressure regulator 13 provided in the low-pressure fuel passage 11B downstream of the filter 12 by bypass. The discharged fuel is sent to a high-pressure fuel pump 14 for high pressure.
【0018】この高圧用の高圧用燃料ポンプ14は、機関
1のクランク軸やカム軸により直接又はギアやベルトを
介して間接的に駆動され、前記低圧の燃料を高圧に加圧
して吐出する。該高圧用ポンプ14から吐出した燃料は、
高圧側燃料通路15にバイパスして設けられた高圧用レギ
ュレータ16により燃圧が一定の高圧用設定値例えば5M
Paに調整される。The high-pressure fuel pump 14 for high pressure is driven directly by the crankshaft or camshaft of the engine 1 or indirectly via gears or belts, and pressurizes and discharges the low-pressure fuel to a high pressure. The fuel discharged from the high-pressure pump 14 is:
The high pressure regulator 16 provided in the high pressure side fuel passage 15 bypasses the high pressure fuel passage 15 so that the fuel pressure is constant at a high pressure set value, for example, 5M.
It is adjusted to Pa.
【0019】そして、マイクロコンピュータを内蔵した
コントロールユニット17から所定噴射タイミングで送ら
れる機関運転状態に応じた所定幅のパルス信号に応じ
て、前記燃料噴射弁2が開制御され、前記所定燃圧に調
整された燃料を燃焼室3内に噴射供給する。前記コント
ロールユニット17には、前記燃料噴射制御のため、機関
回転速度検出用であると共に、前記高圧用燃料ポンプ14
の回転速度検出用でもあるクランク角センサ18、吸入空
気流量検出用のエアフローメータ19、前記高圧側燃料通
路15内の燃料圧力を検出する燃圧センサ20等の各種セン
サからの検出信号が入力されるようになっている。The fuel injection valve 2 is controlled to open in response to a pulse signal of a predetermined width corresponding to the engine operating state sent from the control unit 17 containing a microcomputer at a predetermined injection timing to adjust the fuel pressure to the predetermined fuel pressure. The fuel thus injected is injected into the combustion chamber 3. The control unit 17 is provided for detecting the engine rotational speed for the fuel injection control, and for controlling the fuel injection.
Detection signals from various sensors, such as a crank angle sensor 18 also for detecting the rotation speed of the air, an air flow meter 19 for detecting the intake air flow rate, and a fuel pressure sensor 20 for detecting the fuel pressure in the high-pressure side fuel passage 15 are input. It has become.
【0020】ここで、コントロールユニット17は、前記
噴射パルス信号のパルス幅を制御すると共に、前記噴射
パルス信号の出力開始タイミング、即ち、燃料噴射弁2
による燃料噴射期間を制御するようになっている。そし
て、既述したように始動後、高圧用燃料ポンプ14の吐出
圧の上昇が遅れている間は、前記燃圧センサ20によって
検出された燃圧によって燃料噴射弁2の燃料噴射期間を
補正する。Here, the control unit 17 controls the pulse width of the injection pulse signal, and starts the output of the injection pulse signal, that is, the fuel injection valve 2.
Controls the fuel injection period. As described above, after the start, while the increase in the discharge pressure of the high-pressure fuel pump 14 is delayed, the fuel injection period of the fuel injection valve 2 is corrected by the fuel pressure detected by the fuel pressure sensor 20.
【0021】前記コントロールユニット9による燃圧セ
ンサ20の検出特性学習ルーチンを示す。なお、このルー
チンが、センサ特性学習手段を構成する。また、図4
は、始動後の機関回転速度Neと高圧側燃料通路15内の
燃圧の状態を示したもので、電動式の低圧用燃料ポンプ
10の吐出圧はON操作後速やかに立ち上がるのに対し、
高圧用燃料ポンプ14の吐出圧の上昇は遅く機関回転速度
Neが所定のアイドル回転速度Ni以上となってから燃
圧が高圧レギュレータ16で規制される高圧用設定値PH
(例えば5MPa) に達する。この図4を参照しつつ図
3のフローチャートに従って説明する。A detection characteristic learning routine of the fuel pressure sensor 20 by the control unit 9 will be described. This routine constitutes the sensor characteristic learning means. FIG.
Shows the state of the engine rotational speed Ne and the fuel pressure in the high-pressure side fuel passage 15 after the start, and an electric low-pressure fuel pump
While the discharge pressure of 10 rises immediately after the ON operation,
High-pressure setting value slower the engine speed Ne is increased in the discharge pressure of the high pressure fuel pump 14 is the fuel pressure from when a predetermined idle rotational speed Ni or is restricted by the high pressure regulator 16 P H
(For example, 5 MPa). A description will be given according to the flowchart of FIG. 3 with reference to FIG.
【0022】ステップ (図ではSと記す。以下同様) 1
では、前記燃圧センサ20の検出値をA/D変換してMP
ssとして読み込むと共に、前記クランク角センサ18から
の信号に基づいて算出された機関回転速度Neを読み込
む。ステップ2では、電動式の低圧用燃料ポンプ10がO
Nされているか否かを判定する。Step (S in the figure; the same applies hereinafter) 1
Then, the detection value of the fuel pressure sensor 20 is A / D converted and MP
In addition to reading as ss, the engine rotation speed Ne calculated based on the signal from the crank angle sensor 18 is read. In step 2, the electric low-pressure fuel pump 10
It is determined whether or not N is set.
【0023】低圧用燃料ポンプ10がONされていると判
定されたときはステップ3へ進み、該低圧用燃料ポンプ
10のON操作後、設定時間例えば50msの経過を待って
ステップ4へ進む。なお、前記設定時間が経過したとき
は低圧用燃料ポンプ10からの吐出圧が十分に上昇して、
低圧用レギュレータで規制される低圧用設定値に調整さ
れるように、前記設定時間が設定されている。When it is determined that the low-pressure fuel pump 10 is ON, the routine proceeds to step 3, where the low-pressure fuel pump 10 is turned on.
After the ON operation of 10, the process proceeds to step 4 after a lapse of a set time, for example, 50 ms. When the set time has elapsed, the discharge pressure from the low-pressure fuel pump 10 is sufficiently increased,
The set time is set so as to be adjusted to the set value for low pressure regulated by the regulator for low pressure.
【0024】ステップ4では、機関回転速度Neが略0
つまり略停止状態が否かを判定する。この判定は、高圧
用燃料ポンプ14が実質的に非駆動状態で吐出圧が前記低
圧用設定値未満となっているかを判定するものである。
したがって、この状態が満たされれるように低速に設定
された機関回転速度NL 以下であることを判定条件とし
てもよい。In step 4, the engine speed Ne is set to approximately 0
That is, it is determined whether or not the vehicle is substantially stopped. This determination is to determine whether the discharge pressure is less than the low pressure set value while the high pressure fuel pump 14 is in a substantially non-driven state.
Therefore, the determination condition may be that the engine speed is equal to or lower than the engine speed NL set to a low speed so that this condition is satisfied.
【0025】そして、ステップ4で機関が略停止状態と
判定されたとき、つまり、燃圧が低圧用設定値一定に調
整されている状態 (図4a参照) と判定されたときはス
テップ5へ進み、前記ステップ1で読み込んだ燃圧セン
サ20の検出値MPssを前記低圧用設定値PL に対応した
値MPL として記憶する。ステップ6では、前記MPL
の最新値及び過去複数回の値を加重平均等により平均化
処理して低圧側学習値MPMLとする。If it is determined in step 4 that the engine is substantially stopped, that is, if it is determined that the fuel pressure is being adjusted to a constant low pressure set value (see FIG. 4a), the process proceeds to step 5. storing the detected value MPss of the fuel pressure sensor 20 read in step 1 as the value MP L corresponding to the set value P L for the low pressure. In step 6, the MP L
Is averaged by a weighted average or the like, and the low-pressure side learning value MPML is obtained.
【0026】一方、ステップ4で機関が回転していると
判定されたときはステップ7へ進み、機関回転速度Ne
が所定のアイドル回転速度Ni以上か否かを判定する。
そして、Ne≧Niと判定されたときは、高圧用燃料ポ
ンプ14の吐出圧が十分上昇して前記高圧用設定値に調整
されている状態 (図4b参照) と判断し、ステップ8へ
進んで燃圧センサ20の検出値MPssを前記高圧用設定値
に対応した値MPH として記憶する。On the other hand, if it is determined in step 4 that the engine is rotating, the routine proceeds to step 7, where the engine speed Ne is determined.
Is greater than or equal to a predetermined idle speed Ni.
If it is determined that Ne ≧ Ni, it is determined that the discharge pressure of the high-pressure fuel pump 14 has been sufficiently increased and adjusted to the high-pressure set value (see FIG. 4B). storing the detected value MPss of the fuel pressure sensor 20 as a value MP H corresponding to the high-pressure setting value.
【0027】ステップ9では、前記MPL の最新値及び
過去複数回の値を加重平均等により平均化処理して高圧
側学習値MPMHとする。ステップ10では、現在燃圧セン
サ20で検出された検出値MPssと、低圧用設定値PL と
それに対応した低圧側学習値MPML、高圧用設定値PH
とそれに対応した高圧側学習値MPMHとに基づいて、燃
圧センサ20の検出値MPssに対応する実際の燃圧Pssを
算出する特性式を、次式のように設定する。[0027] In step 9, the high-pressure side learning value MP MH latest value and the value of the past multiple times of the MP L and averaging process by a weighted average or the like. In step 10, the detected value MPss detected by the current fuel pressure sensor 20, the low-pressure side learning value MP ML corresponding thereto and low pressure set value P L, a high-pressure setting value P H
And based on by the high-pressure side learning value MP MH correspondence thereto, the characteristic equation for calculating the actual fuel pressure Pss corresponding to the detection value MPss of the fuel pressure sensor 20 are set as follows.
【0028】Pss=PL + (PH −PL ) ・ (MPss−
MPML) / (MPMH−MPML) 例えば、PL =0.3 MPa、PH =5.0 MPaの場合
は、 Pss=0.3 +4.7 × (MPss−MPML) / (MPMH−M
PML) [MPa] となる。即ち、燃圧センサの精度悪化の要因はオフセッ
トエラーが主であるため、図5に示すように、実際の燃
圧がPL 及びPH に調整された状態での燃圧センサ20の
各検出値MPssにはバラツキがあるが、それらの検出値
(出力電圧) を学習しておけば、その間の燃圧センサの
出力特性のリニアリティ、つまり燃圧の変化に対してセ
ンサ出力が比例的に変化する特性は良好であるので、前
記の演算式によって機関の始動後高圧用燃料ポンプの吐
出圧が燃圧が低圧用設定値から高圧用設定値に上昇する
までの間の燃圧を精度良く検出することができる。Pss = P L + (P H −P L ) · (MPss−
MP ML) / (MP MH -MP ML) For example, P L = 0.3 MPa, in the case of P H = 5.0 MPa, Pss = 0.3 +4.7 × (MPss-MP ML) / (MP MH -M
P ML ) [MPa]. That is, since the offset error is the main cause of the deterioration of the accuracy of the fuel pressure sensor, as shown in FIG. 5, the detected value MPss of the fuel pressure sensor 20 in a state where the actual fuel pressure is adjusted to P L and P H is shown. Vary, but their detected values
If (output voltage) is learned, the linearity of the output characteristic of the fuel pressure sensor during that period, that is, the characteristic in which the sensor output changes proportionally to the change in fuel pressure, is good. It is possible to accurately detect the fuel pressure of the discharge pressure of the high-pressure fuel pump after the start until the fuel pressure rises from the low-pressure set value to the high-pressure set value.
【0029】図6は、始動時及び始動直後の燃料噴射量
を補正するルーチンのフローチャートを示す。このルー
チンが燃料噴射量補正手段を構成する。ステップ11で
は、燃圧センサ20により検出された燃圧の検出値MPss
を読み込む。ステップ12では、前記燃圧センサ20の検出
値MPssと、前記図3で設定された燃圧センサの特性式
により燃圧Pssを算出する。FIG. 6 shows a flowchart of a routine for correcting the fuel injection amount at the start and immediately after the start. This routine constitutes the fuel injection amount correction means. In step 11, the detected value MPss of the fuel pressure detected by the fuel pressure sensor 20
Read. In step 12, the fuel pressure Pss is calculated from the detected value MPss of the fuel pressure sensor 20 and the characteristic equation of the fuel pressure sensor set in FIG.
【0030】ステップ13では、算出された燃圧Pssが、
前記高圧用設定値PH (=5MPa) 未満であるか否か
を判定する。Pss<PH と判定されたときはステップ14
へ進み、次式により燃料噴射量の補正係数kを算出す
る。 k= (PH /Pss) 1/2 ステップ15では、始動時の燃料噴射量TI を次式により
演算する。In step 13, the calculated fuel pressure Pss is
It is determined whether or not the value is lower than the high pressure set value P H (= 5 MPa). Pss <When it is determined that the P H Step 14
Then, the correction coefficient k of the fuel injection amount is calculated by the following equation. k = In (P H / Pss) 1/2 Step 15, the fuel injection amount T I at the start, is calculated by the following equation.
【0031】TI =Te×k+Ts なお、前記Teは、燃圧が前記高圧用設定値PH に調整
された状態で燃料を噴射する場合の有効噴射パルス幅で
あり、Tsはバッテリ電圧に応じた無効噴射パルス幅で
ある。また、ステップ13でPss≒PH と判定されたとき
はステップ16へ進み、前記燃圧による補正を行うことな
く、次式により燃料噴射量TI を演算する。T I = Te × k + Ts Here, Te is an effective injection pulse width when fuel is injected with the fuel pressure adjusted to the high pressure set value P H , and Ts corresponds to the battery voltage. Invalid injection pulse width. Further, the process proceeds to step 16 when it is determined that Pss ≒ P H in step 13, without performing correction by the fuel pressure, and calculates the fuel injection amount T I by the following equation.
【0032】TI =Te+Ts このようにすれば、それほど精度の高くない安価な燃圧
センサを用いても、前記プレッシャレギュレータによる
調整値を利用した学習を行うことによって、燃圧を精度
良く検出することができ、以て、始動及び始動直後の高
圧用燃料ポンプの吐出圧が上昇中にあるときの燃圧に基
づいた燃料噴射量の補正を、精度良く行え、以て始動性
能を改善できる。T I = Te + Ts In this way, even if an inexpensive fuel pressure sensor that is not so accurate is used, the fuel pressure can be detected with high accuracy by performing learning using the adjustment value of the pressure regulator. Accordingly, the fuel injection amount can be accurately corrected based on the fuel pressure when the discharge pressure of the high-pressure fuel pump is increasing immediately after the start and immediately after the start, so that the starting performance can be improved.
【図1】本発明の構成・機能を示すブロック図。FIG. 1 is a block diagram showing the configuration and functions of the present invention.
【図2】本発明の一実施形態の全体システム構成を示す
図。FIG. 2 is a diagram showing an overall system configuration according to an embodiment of the present invention.
【図3】前記実施形態における燃圧センサの特性を学習
するルーチンを示すフローチャート。FIG. 3 is a flowchart showing a routine for learning characteristics of a fuel pressure sensor in the embodiment.
【図4】機関始動時及び始動直後の機関回転速度と燃圧
との関係を示すタイムチャート。FIG. 4 is a time chart showing the relationship between the engine speed and the fuel pressure at the time of starting the engine and immediately after the starting.
【図5】燃圧センサの検出値と実際の燃圧との関係を示
す線図。FIG. 5 is a diagram showing a relationship between a detection value of a fuel pressure sensor and an actual fuel pressure.
【図6】燃料噴射量の設定ルーチンを示すフローチャー
ト。FIG. 6 is a flowchart showing a routine for setting a fuel injection amount.
1 内燃機関 2 燃料噴射弁 3 燃焼室 9 燃料タンク 10 低圧用燃料ポンプ 13 低圧用レギュレータ 16 高圧用燃料ポンプ 15 高圧用レギュレータ 17 コントロールユニット 20 燃圧センサ DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Fuel injection valve 3 Combustion chamber 9 Fuel tank 10 Low pressure fuel pump 13 Low pressure regulator 16 High pressure fuel pump 15 High pressure regulator 17 Control unit 20 Fuel pressure sensor
Claims (4)
ポンプと、該低圧用燃料ポンプから吐出された燃料を吸
入して相対的に高圧で吐出する高圧用燃料ポンプと、前
記低圧用燃料ポンプからの吐出燃圧が十分上昇したとき
の燃圧を低圧用設定値に調整する低圧用レギュレータ
と、前記高圧用燃料ポンプからの吐出燃圧が十分上昇し
たときの燃圧を高圧用設定値に調整する高圧用レギュレ
ータと、該高圧用レギュレータで燃圧を調整された燃料
を燃料噴射弁によって機関に供給する一方、 前記高圧用燃料ポンプから吐出される燃圧を検出する燃
圧センサを備え、前記高圧用燃料ポンプの上昇中の吐出
燃圧を検出し、該検出された燃圧に基づいて燃料噴射量
を補正する燃料噴射量補正手段を備えた内燃機関の燃料
系において、 前記低圧用燃料ポンプの吐出圧が十分上昇し、かつ、前
記高圧用燃料ポンプが実質的に非駆動状態であるときに
前記燃圧センサの検出値を前記低圧用レギュレータで調
整される低圧用設定値と対応させ、前記高圧用燃料ポン
プの吐出圧が十分上昇したときの前記燃圧センサの検出
値を前記高圧用レギュレータで調整される高圧用設定値
と対応させる学習を行い、該2点の学習された検出値と
各設定値とに基づいて、該燃圧センサの検出値と実際の
燃圧との関係を学習するセンサ特性学習手段を設けたこ
とを特徴とする燃圧センサの特性学習装置。A low-pressure fuel pump for discharging fuel at a relatively low pressure; a high-pressure fuel pump for sucking fuel discharged from the low-pressure fuel pump and discharging at a relatively high pressure; A low pressure regulator that adjusts the fuel pressure when the fuel pressure discharged from the fuel pump is sufficiently increased to a low pressure set value, and a fuel pressure when the fuel pressure discharged from the high pressure fuel pump is sufficiently increased is adjusted to a high pressure set value. A high-pressure regulator, and a fuel pressure sensor that detects fuel pressure discharged from the high-pressure fuel pump while supplying fuel whose fuel pressure has been adjusted by the high-pressure regulator to an engine through a fuel injection valve; A low-pressure fuel in an internal combustion engine fuel system comprising a fuel injection amount correcting means for detecting a discharge fuel pressure during the rise of the fuel pressure and correcting the fuel injection amount based on the detected fuel pressure. When the discharge pressure of the pump is sufficiently increased, and the high-pressure fuel pump is substantially in a non-driving state, the detection value of the fuel pressure sensor is made to correspond to the low-pressure set value adjusted by the low-pressure regulator, Learning is performed to make the detected value of the fuel pressure sensor when the discharge pressure of the high-pressure fuel pump sufficiently rises correspond to the high-pressure set value adjusted by the high-pressure regulator, and the learned detection values of the two points are A characteristic learning device for a fuel pressure sensor, comprising: sensor characteristic learning means for learning a relationship between a detected value of the fuel pressure sensor and an actual fuel pressure based on each set value.
記高圧用燃料ポンプは機関駆動されることを特徴とする
請求項1に記載の燃圧センサの特性学習装置。2. The characteristic learning device for a fuel pressure sensor according to claim 1, wherein the low-pressure fuel pump is electrically driven, and the high-pressure fuel pump is driven by an engine.
レギュレータで調整される低圧用設定値と対応させる条
件は、前記電動式の低圧用燃料ポンプがON状態で、か
つ、機関回転速度が所定未満の低速状態であることを特
徴とする請求項2に記載の燃圧センサの特性学習装置。3. A condition for making the detection value of the fuel pressure sensor correspond to a low pressure set value adjusted by the low pressure regulator is such that the electric low pressure fuel pump is in an ON state and the engine speed is low. 3. The characteristic learning device for a fuel pressure sensor according to claim 2, wherein the low-speed state is less than a predetermined value.
の燃焼室に直接噴射することを特徴とする請求項1〜請
求項3のいずれか1つに記載の内燃機関用燃料ポンプの
吐出量推定装置。4. The fuel pump for an internal combustion engine according to claim 1, wherein said fuel injection valve directly injects fuel into a combustion chamber of a spark ignition type engine. Discharge amount estimation device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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JP16616196A JP3250092B2 (en) | 1996-06-26 | 1996-06-26 | Characteristic learning device for fuel pressure sensor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16616196A JP3250092B2 (en) | 1996-06-26 | 1996-06-26 | Characteristic learning device for fuel pressure sensor |
Publications (2)
Publication Number | Publication Date |
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JPH109073A true JPH109073A (en) | 1998-01-13 |
JP3250092B2 JP3250092B2 (en) | 2002-01-28 |
Family
ID=15826210
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US10161349B2 (en) | 2015-06-08 | 2018-12-25 | Ford Global Technologies, Llc | Method and system for fuel system control |
CN108474311A (en) * | 2015-10-29 | 2018-08-31 | 法国大陆汽车公司 | The method of the operation of high-pressure fuel supply system for checking internal combustion engine |
CN108474311B (en) * | 2015-10-29 | 2021-07-23 | 法国大陆汽车公司 | Method for checking the operation of a high-pressure fuel supply system of an internal combustion engine |
US10519890B2 (en) | 2018-03-26 | 2019-12-31 | Ford Global Technologies, Llc | Engine parameter sampling and control method |
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