EP1567758B1 - Method and device for operating an injection system in an internal combustion engine - Google Patents

Method and device for operating an injection system in an internal combustion engine Download PDF

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Publication number
EP1567758B1
EP1567758B1 EP03767399A EP03767399A EP1567758B1 EP 1567758 B1 EP1567758 B1 EP 1567758B1 EP 03767399 A EP03767399 A EP 03767399A EP 03767399 A EP03767399 A EP 03767399A EP 1567758 B1 EP1567758 B1 EP 1567758B1
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EP
European Patent Office
Prior art keywords
injection
activation
pulse
state variable
common
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EP03767399A
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German (de)
French (fr)
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EP1567758A1 (en
Inventor
Johannes-Joerg Rueger
Udo Schulz
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Robert Bosch GmbH
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Robert Bosch GmbH
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
    • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
    • F02D41/2425—Particular ways of programming the data
    • F02D41/2429—Methods of calibrating or learning
    • F02D41/2451—Methods of calibrating or learning characterised by what is learned or calibrated
    • F02D41/2464—Characteristics of actuators
    • F02D41/2467—Characteristics of actuators for injectors
    • F02D41/247—Behaviour for small quantities
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
    • F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
    • F02D35/027—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions using knock sensors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D41/2096—Output circuits, e.g. for controlling currents in command coils for controlling piezoelectric injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
    • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
    • F02D41/2425—Particular ways of programming the data
    • F02D41/2429—Methods of calibrating or learning
    • F02D41/2438—Active learning methods
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2055—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit with means for determining actual opening or closing time
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
    • F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
    • F02D35/021—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions using an ionic current sensor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
    • F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
    • F02D35/023—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining the cylinder pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/12—Introducing corrections for particular operating conditions for deceleration
    • F02D41/123—Introducing corrections for particular operating conditions for deceleration the fuel injection being cut-off

Definitions

  • the invention relates to a method and an apparatus for operating a common rail injection system of an internal combustion engine according to the preambles of the respective independent claims.
  • Such an injection valve is used for finely adjustable fuel metering in the combustion chamber of the internal combustion engine.
  • the piezoelectric actuator is used to control the movement of a nozzle needle of the injection valve, whereby either the nozzle needle itself or a control valve controlling the movement of the nozzle needle is actuated.
  • From the DE 199 05 340 is a method for presetting and dynamic tracking piezoelectric actuators known. To set a desired idle stroke between the actuator and the piezoelectric actuator DC voltage is supplied to the piezoelectric actuator, which causes an independent of the driving voltage change in length of the piezoelectric actuator.
  • the required for a given injection quantity, pulse-shaped control voltage of these piezo actuators is known to be dependent on state variables of the injection system such as.
  • the said dependence on the rail pressure results from the aforementioned mode of operation of the injection valve and the said temperature dependence from the temperature-variable stroke of the piezo actuator.
  • the effect on the injection quantity results from the different actual start of actuation or the actuation end with a varying actuator stroke or varying hydraulic and mechanical operating parameters.
  • a method for controlling a fuel injection system with a high-pressure fuel pump emerges, wherein the injected into the respective combustion chambers of the internal combustion engine fuel quantity is controlled by means of solenoid valves.
  • Manufacturing and age-related variations in the injected fuel quantity into the individual combustion chambers cause different fuel quantities to be supplied with the same activation signal, which is the case lead to significant quantity errors especially in injected in pre-injections small quantities.
  • the pulse duration of the drive pulses of the solenoid valve, in which a pilot injection is currently being used is determined in certain operating states of the internal combustion engine. Based on the duration of the drive pulses determined in this way, compensation signals for the drive pulses are formed and permanently stored.
  • the present invention has for its object to improve a method and an apparatus of the type mentioned in that by adapting the control voltage of injection actuators, such as piezo actuators, an injection system, the quantity accuracy of metered fuel, especially during operation of the engine or an underlying motor vehicle is increased.
  • injection actuators such as piezo actuators
  • an injection system the quantity accuracy of metered fuel, especially during operation of the engine or an underlying motor vehicle is increased.
  • an injection system for example a common rail or a pump-nozzle injection system of an internal combustion engine with at least one controllable by means of drive pulses injection actuator, wherein the control of the injection actuator of at least one state variable of the injection system is dependent on the at least a state variable detected and cached.
  • at least one of the injection actuators is driven with a drive pulse of predeterminable pulse duration and predefinable output pulse height, and during this time an injection detection is performed.
  • the pulse height of the drive pulse is incremented in predetermined steps at the predetermined pulse duration until an injection is detected.
  • the pulse height of the drive pulse causing the injection is permanently stored as a function of the detected state variable and used in the future operation of the injection system in the control of the at least one injection actuator.
  • the advantage of the method according to the invention over the prior art is that the drive voltage required for each individual injection actuator or injector in the respective operating condition of the injection system, for example the currently prevailing rail pressure and the temperature of the injection actuator or injector, during operation of the internal combustion engine or of the underlying motor vehicle is adapted to the currently existing operating state.
  • the said state variable of the injection system here also includes operating variables of the injection actuator itself, which originate in particular from specimen scattering during its production.
  • the invention is based, in particular, on the effect which is known per se, that in the injection valves or injection actuators concerned here, a minimum, rail pressure-dependent activation voltage is required in order to realize an effective injection.
  • a minimum, rail pressure-dependent activation voltage is required in order to realize an effective injection.
  • the injection actuator is subjected to a lower voltage, then the force generated thereby is insufficient to open the control valve against the rail pressure.
  • the invention is also based on the finding that when the drive voltage is increased successively, an injection starts instantaneously as soon as the drive voltage is sufficiently high. That There is a sharp separation with regard to the system reaction with respect to a too small / sufficient drive voltage.
  • the proposed method makes use of this property by using the values of the drive voltage U_erf adapted during operation of the internal combustion engine with characteristic curve (s), characteristic maps or tables, in particular of the value pairs U_erf (p_rail) and / or U_erf (T_actor), with great precision under real operating conditions.
  • a further advantage is that the drive voltage can be adapted to changing operating conditions of the internal combustion engine, in particular changing state variables of the injection system, without additional sensory outlay, resulting in an even more precise fuel metering compared to the prior art.
  • the method allows a specific for each injector or injector and for each combustion chamber of the internal combustion engine individual adaptation of the respective electrical drive voltage in the metering of fuel.
  • the invention further relates to a device, in particular for carrying out the aforementioned method, comprising first means for detecting the at least one state variable and temporarily storing an approximately detected state variable, second means for controlling the at least one injection actuator with a drive pulse of predefinable pulse duration and predefinable output pulse height, third means for Performing an injection detection in the control of the at least one injection actuator, fourth means for incrementing the pulse height of the drive pulse in predetermined steps at the predetermined pulse duration, and fifth means for permanently storing the pulse height of the injection effecting drive pulse as a function of the detected state variable in the case of a detected injection having.
  • the Fig. 1 shows the basic structure of a fuel injection system of a self-igniting internal combustion engine according to the prior art ( DE 39 29 747 A1 ).
  • the internal combustion engine 10 shown here only schematically receives a certain amount of fuel from an injection unit 30.
  • the instantaneous operating state of the internal combustion engine 10 is detected by means of sensors 40 and the measured values 15 thus acquired are transmitted to a control unit 20.
  • These measured values include, for example, the speed and the temperature of the internal combustion engine as well as the actual start of injection and possibly even further variables 25 which characterize the operating state of the internal combustion engine, such as the position of an accelerator pedal 25 or the ambient air pressure.
  • the control unit 20 calculates drive pulses 35 corresponding to the fuel quantity desired by the driver, with which a quantity-determining element of the injection unit 30 is acted upon.
  • a quantity-determining member there is a solenoid valve which is arranged so that the amount of fuel to be injected is determined by the opening duration or the closing time of the solenoid valve.
  • solenoid valves and other electrically controllable injectors with eg. Piezo actuators may be arranged. However, the method described below is unaffected.
  • the (not shown) solenoid valve is disadvantageous insofar as different closing times can result with identical drive pulse and therefore different amounts of fuel are injected at the same time duration of the drive pulse and otherwise the same operating parameters. Since the drive pulses are usually very short, in particular during pilot injections, it may now be the case that no pilot injection takes place in the case of individual solenoid valves or the pilot injection becomes so strong that the exhaust gas values of the internal combustion engine deteriorate.
  • FIG. 2 is a in the art ( DE 100 02 270 C1 ) known, piezoelectrically controllable injection valve 101 shown in a sectional drawing.
  • the valve 101 has a piezoelectric actuator 104 for actuating a valve member 103 axially displaceable in a bore 113 of a valve body 107.
  • the valve 101 also has an actuating piston 109 adjoining the piezoelectric actuator 104 and an actuating piston 114 adjoining a valve closing member 115. Between the pistons 109, 114 a working as a hydraulic ratio hydraulic chamber 116 is arranged.
  • the valve closure member 115 cooperates with at least one valve seat 118, 119 and separates a low-pressure region 120 from a high-pressure region 121.
  • An electrical control unit 112 indicated only schematically, supplies the drive voltage for the piezoelectric actuator 104 as a function of, in particular, the pressure level in the high-pressure region 121.
  • the device shown for operating a common-rail injection system of an internal combustion engine comprises a so-called release module 200, which in the exemplary embodiment can be unlocked by means of a push bit 205 provided by a control unit, not shown.
  • Possible further input variables of the release module are the current rail pressure and / or the instantaneous temperature of the piezo actuator.
  • a rail pressure control 210 is also arranged, the operation of which is triggered by the release module 200.
  • a function module 215 for triggering the injection actuators according to the invention and subsequent adaptation of the activation signals is triggered accordingly.
  • Another input signal 220 of the last-mentioned function module 215 is provided in the present exemplary embodiment by a speed signal evaluation module 225, which performs an injection recognition on the basis of a speed signal provided by the control unit.
  • Fig. 4 are typical An horrendsimpulse shown to illustrate the stepwise increase of the drive voltage at a constant drive time.
  • the first voltage pulse 400 differs from the second voltage pulse 405 only by the shown voltage increment .DELTA.U1, wherein the shown average pulse duration .DELTA.t1 coincides in both voltage pulses.
  • the system reaction ie the success of an injection in the combustion chamber of the internal combustion engine assigned to the controlled injector, is monitored 525. In the present exemplary embodiment, this takes place by means of the above-mentioned speed signal evaluation module 225. If an injection is detected, the for this causal control voltage U_erf together with the currently present value of the rail pressure permanently stored 530. In the case, however, that no injection detected is, the drive voltage is gradually incremented 535 and then each monitored the speed signal until a torque-forming and thus speed-increasing injection is detected 525. The then underlying drive voltage U_erf is stored 530 together with the rail pressure value.
  • the procedure shown is carried out at different line pressures, thereby enabling the detection of a characteristic curve U_erf (p_Rail).
  • U_erf characteristic curve U_erf
  • the fineness of the above-described increments of the drive voltage essentially determines the achievable scattering of the determined characteristic values and thus ultimately the maximum achievable precision in the fuel metering.
  • the values of the drive voltage determined in this way each represent minimum voltages which lead to an actuator movement and thus to an indirectly measurable injection at the current rail pressure.
  • the above-described procedure may be further applied to all combustion chambers (cylinders) of the internal combustion engine. It may be necessary to control the rail pressure in overrun to a value that differs from the prevailing at the relevant operating point of the internal combustion engine rail pressure. Consequently, the achievable rail pressure range will be limited to the top, so that the adaptation can be performed only within a limited rail pressure range and an extrapolation must be made for the rest of the rail pressure range.
  • the respectively determined value of the drive voltage is compared with predetermined voltage values determined in advance empirically and a correction value is determined from the possibly resulting difference.
  • the storage of the determined values of the drive voltage is filtered in the characteristic curve. If, for example, the rail pressure leaves the currently active pressure range which is the basis of the characteristic curve, the respectively newly adapted value of the drive voltage before filing is filtered with the old voltage value, in particular weighted therewith, whereby the influence of measurement disturbances in the generation of the characteristic curve is reduced ,
  • the said injection recognition takes place indirectly on the basis of operating parameters of the internal combustion engine. However, it does not depend on the underlying operating characteristic.
  • a preferred operating parameter is, as described above, the speed or the value of a speed signal provided by the internal combustion engine or a corresponding engine control unit.
  • other variables already present in the control unit such as the pressure signal provided by a combustion chamber pressure sensor, the knock signal provided by a knock sensor arranged in the combustion chamber or the ion current signal provided by an ion current sensor, are considered.
  • the size of the drive duration permanently predetermined in the described method is selected such that at the current rail pressure a maximum of one injection quantity is realized which is not noticeable to the driver of the underlying vehicle, so that no loss of comfort occurs due to the above-described adaptation procedure ,
  • the above-described characteristic curve U_erf (p_Rail) is only an example and other parameter pairs such as, for example, the control voltage 'U_erf' can be used as the basis for the actuator temperature 'T_Piezo actuator'.
  • the above-described injection system with a piezoelectrically controlled injection actuator is only understood as an exemplary embodiment and may, for example, also include magnetically controlled actuators or the like.

Abstract

Disclosed are a method and a device for operating an injection system in an internal combustion engine (10), according to which an injection actuator (104) is triggered (215) based on at least one state variable of an injection system. In order to increase the accuracy of the quantity of fuel that is apportioned, the at least one state variable is detected and is temporarily stored, the at least one injection actuator (104) is triggered (520) by means of a triggering pulse that lasts a given period of time and has a given output amplitude, the injection is detected (525) when the at least one injection actuator (104) is triggered (520), the amplitude of the triggering pulse is incremented (535) in predefined steps lasting said given period of time until an injection is detected (525), and the amplitude of the triggering pulse causing the injection is permanently stored (530) as a function of the detected state variable in case an injection is detected and is used as a basis for triggering the at least one injection actuator during future operation of the injection system.

Description

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zum Betrieb eines Common-Rail-Einspritzsystems einer Brennkraftmaschine gemäß den Oberbegriffen der jeweiligen unabhängigen Ansprüche.The invention relates to a method and an apparatus for operating a common rail injection system of an internal combustion engine according to the preambles of the respective independent claims.

Ein hier betroffenes Hochdruck- oder Common-Rail-Einspritzsystem sowie ein mit einem Piezo-Aktor als Einspritzaktor ausgestattetes Einspritzventil (Injektor) gehen aus der DE 100 32 022 A1 und der DE 100 02 270 C1 hervor. Ein solches Einspritzventil dient zur fein regulierbaren Kraftstoffzumessung in den Verbrennungsraum der Brennkraftmaschine.A high-pressure or common-rail injection system affected here, as well as an injection valve (injector) equipped with a piezo actuator as an injection actuator, emerge from the DE 100 32 022 A1 and the DE 100 02 270 C1 out. Such an injection valve is used for finely adjustable fuel metering in the combustion chamber of the internal combustion engine.

In einem solchen Einspritzventil dient der Piezo-Aktor zur Steuerung der Bewegung einer Düsennadel des Einspritzventils, wobei entweder die Düsennadel selbst oder ein die Bewegung der Düsennadel steuerndes Steuerventil angesteuert wird.In such an injection valve, the piezoelectric actuator is used to control the movement of a nozzle needle of the injection valve, whereby either the nozzle needle itself or a control valve controlling the movement of the nozzle needle is actuated.

Zur exakten Zumessung von Kraftstoff in den Verbrennungsraum ist eine möglichst genaue Kenntnis des Hubes des Piezo-Aktors bzw. der Düsennadel im Zusammenspiel mit dem Steuerventil erforderlich. Wie aus der Fig. 1 zu ersehen, wird bei den in der DE 100 02 270 C1 beschriebenen Piezo-Common-Rail(PCR)-Systemen über den Piezo-Aktor und einen zwischengeschalteten hydraulischen Koppler das Steuerventil betätigt, welches wiederum durch Modulation des Druckes in einem so genannten Steuerraum die Düsennadelbewegung steuert.For precise metering of fuel into the combustion chamber, the most accurate possible knowledge of the stroke of the piezoelectric actuator or the nozzle needle in conjunction with the control valve is required. Like from the Fig. 1 can be seen in the in the DE 100 02 270 C1 described piezo common rail (PCR) systems via the piezoelectric actuator and an intermediate hydraulic coupler actuates the control valve, which in turn controls the nozzle needle movement by modulating the pressure in a so-called control room.

Aus der DE 199 05 340 ist ein Verfahren zur Voreinstellung und dynamischen Nachführung piezoelektrischer Aktoren bekannt. Zum Einstellen eines gewünschten Leerhubes zwischen dem Betätigungselement und dem Piezoaktors wird dem Piezoaktor Gleichspannung zugeführt, die eine von der Ansteuerspannung unabhängige Längenänderung des Piezoaktors bewirkt.From the DE 199 05 340 is a method for presetting and dynamic tracking piezoelectric actuators known. To set a desired idle stroke between the actuator and the piezoelectric actuator DC voltage is supplied to the piezoelectric actuator, which causes an independent of the driving voltage change in length of the piezoelectric actuator.

Die für eine bestimmte Einspritzmenge erforderliche, impulsförmige Ansteuerspannung dieser Piezo-Aktoren ist bekanntermaßen von Zustandsgrößen des Einspritzsystems wie bspw. den im Common-Rail momentan herrschenden Raildruck oder der Temperatur des Piezo-Aktors abhängig. Daher hat zur Ermöglichung kleinster Einspritzmengen eine entsprechende Adaption der Ansteuerspannung zu erfolgen. Die genannte Abhängigkeit vom Raildruck ergibt sich aus der vorgenannten Funktionsweise des Einspritzventils und die genannte Temperaturabhängigkeit aus dem mit der Temperatur veränderlichen Hub des Piezo-Aktors. Die Auswirkung auf die Einspritzmenge ergibt sich durch den unterschiedlichen realen Ansteuerbeginn bzw. das Ansteuerende bei variierendem Aktorhub oder variierendem hydraulischen und mechanischen Betriebsparametern.The required for a given injection quantity, pulse-shaped control voltage of these piezo actuators is known to be dependent on state variables of the injection system such as. The current rail pressure prevailing in the common rail or the temperature of the piezoelectric actuator. Therefore, to enable smallest injection quantities, a corresponding adaptation of the drive voltage has to be made. The said dependence on the rail pressure results from the aforementioned mode of operation of the injection valve and the said temperature dependence from the temperature-variable stroke of the piezo actuator. The effect on the injection quantity results from the different actual start of actuation or the actuation end with a varying actuator stroke or varying hydraulic and mechanical operating parameters.

Zu den genannten Zustandsgrößen hinzu kommen Exemplarstreuungen insbesondere des Aktorhubs und Streuungen bei der Funktion des hydraulischen Kopplers, beim Steuerventilsitz, o: ä.In addition to the mentioned state variables are specimen scattering, in particular of the actuator stroke and variations in the function of the hydraulic coupler, the control valve seat, o: Ä.

Die genannten Effekte werden im Stand der Technik im Rahmen einer stationär durchgeführten ,worst-case'-Betrachtung berücksichtigt, d.h. sie können nicht bei einer im Betrieb der Brennkraftmaschine erfolgenden Ansteuerung berücksichtigt werden. Daher wird nicht ermöglicht, die Genauigkeit der Einspritzmengen im Betrieb noch weiter zu verbessern. Gerade im Hinblick auf zukünftig einzuhaltende Abgasnormen wird dies nachteilig sein.The mentioned effects are taken into account in the state of the art in the context of a stationary carried out, worst-case 'consideration, i. they can not be taken into account in an activation taking place during operation of the internal combustion engine. Therefore, it is not possible to further improve the accuracy of injection quantities in operation. This will be disadvantageous, especially with regard to emission standards to be observed in the future.

Aus der DE 39 29 747 A1 geht ferner ein Verfahren zur Steuerung eines Kraftstoffeinspritzsystems mit einer Hochdruckkraftstoffpumpe hervor, wobei die in die jeweiligen Verbrennungsräume der Brennkraftmaschine einzuspritzende Kraftstoffmenge mittels Magnetventilen gesteuert wird. Fertigungs- und altersbedingte Streuungen in der eingespritzten Kraftstoffmenge in die einzelnen Verbrennungsräume bewirken, dass bei gleichem Ansteuersignal unterschiedliche Kraftstoffmengen zugeführt werden, was insbesondere bei in Voreinspritzungen eingespritzten Kleinstmengen zu erheblichen Mengenfehlern führen. Zur Vermeidung dieser Streuungen wird in bestimmten Betriebszuständen der Brennkraftmaschine die Impulsdauer der Ansteuerimpulse des Magnetventils, bei der gerade eine Voreinspritzung einsetzt, ermittelt. Ausgehend von der so ermittelten Dauer der Ansteuerimpulse werden Abgleichsignale für die Ansteuerimpulse gebildet und dauerhaft abgespeichert.From the DE 39 29 747 A1 Furthermore, a method for controlling a fuel injection system with a high-pressure fuel pump emerges, wherein the injected into the respective combustion chambers of the internal combustion engine fuel quantity is controlled by means of solenoid valves. Manufacturing and age-related variations in the injected fuel quantity into the individual combustion chambers cause different fuel quantities to be supplied with the same activation signal, which is the case lead to significant quantity errors especially in injected in pre-injections small quantities. To avoid these variations, the pulse duration of the drive pulses of the solenoid valve, in which a pilot injection is currently being used, is determined in certain operating states of the internal combustion engine. Based on the duration of the drive pulses determined in this way, compensation signals for the drive pulses are formed and permanently stored.

Der vorliegenden Erfindung liegt die Aufgabe zugrunde, ein Verfahren und eine Vorrichtung der eingangs genannten Art dahingehend zu verbessern, dass durch Adaption der Ansteuerspannung von Einspritzaktoren, beispielsweise Piezo-Aktoren, eines Einspritzsystems die Mengengenauigkeit an zugemessenem Kraftstoff, insbesondere auch im Betrieb der Brennkraftmaschine bzw. eines zugrundeliegenden Kraftfahrzeuges, erhöht wird.The present invention has for its object to improve a method and an apparatus of the type mentioned in that by adapting the control voltage of injection actuators, such as piezo actuators, an injection system, the quantity accuracy of metered fuel, especially during operation of the engine or an underlying motor vehicle is increased.

Diese Aufgabe wird gelöst durch die Merkmale des Anspruchs 1. Vorteilhafte Ausgestaltungen sind Gegenstand der Unteransprüche.This object is achieved by the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

Bei dem erfindungsgemäßen Verfahren zum Betrieb eines Einspritzsystems, beispielsweise eines Common-Rail- oder eines Pumpe-Düse-Einspritzsystems einer Brennkraftmaschine mit wenigstens einem mittels Ansteuerimpulsen steuerbaren Einspritzaktor, wobei die Ansteuerung des Einspritzaktors von wenigstens einer Zustandsgröße des Einspritzsystems abhängig ist, wird zunächst die wenigstens eine Zustandsgröße erfasst und zwischengespeichert. Danach wird wenigstens einer der Einspritzaktoren mit einem Ansteuerimpuls vorgebbarer Impulsdauer und vorgebbarer Ausgangsimpulshöhe angesteuert und währenddessen eine Einspritzerkennung durchgeführt. Im Falle, dass zunächst keine Einspritzung erkannt wird, wird die Impulshöhe des Ansteuerimpulses in vorgebbaren Schritten bei der vorgegebenen Impulsdauer so lange inkrementiert, bis eine Einspritzung erkannt wird. Im Falle einer erkannten Einspritzung wird die Impulshöhe des die Einspritzung bewirkenden Ansteuerimpulses als Funktion der erfassten Zustandsgröße dauerhaft abgespeichert und im zukünftigen Betrieb des Einspritzsystems bei der Ansteuerung des wenigstens einen Einspritzaktors zugrunde gelegt.In the method according to the invention for operating an injection system, for example a common rail or a pump-nozzle injection system of an internal combustion engine with at least one controllable by means of drive pulses injection actuator, wherein the control of the injection actuator of at least one state variable of the injection system is dependent on the at least a state variable detected and cached. Thereafter, at least one of the injection actuators is driven with a drive pulse of predeterminable pulse duration and predefinable output pulse height, and during this time an injection detection is performed. In the event that initially no injection is detected, the pulse height of the drive pulse is incremented in predetermined steps at the predetermined pulse duration until an injection is detected. In the case of a detected injection, the pulse height of the drive pulse causing the injection is permanently stored as a function of the detected state variable and used in the future operation of the injection system in the control of the at least one injection actuator.

Der Vorteil des erfindungsgemäßen Verfahrens gegenüber dem Stand der Technik besteht darin, dass die für jeden einzelnen Einspritzaktor bzw. Injektor bei der jeweiligen Betriebsbedingung des Einspritzsystems, bspw. dem momentan herrschenden Raildruck und der Temperatur des Einspritzaktors bzw. Injektors, erforderliche Ansteuerspannung im Betrieb der Brennkraftmaschine bzw. des zugrundeliegenden Kraftfahrzeuges an den aktuell vorliegenden Betriebszustand adaptiert wird. Die genannte Zustandsgröße des Einspritzsystems umfasst vorliegend auch Betriebsgrößen des Einspritzaktors selbst, welche insbesondere von Exemplarstreuungen bei dessen Herstellung herrühren.The advantage of the method according to the invention over the prior art is that the drive voltage required for each individual injection actuator or injector in the respective operating condition of the injection system, for example the currently prevailing rail pressure and the temperature of the injection actuator or injector, during operation of the internal combustion engine or of the underlying motor vehicle is adapted to the currently existing operating state. The said state variable of the injection system here also includes operating variables of the injection actuator itself, which originate in particular from specimen scattering during its production.

Bei der Erfindung liegt insbesondere der an sich bekannte Effekt zugrunde, dass bei den hier betroffenen Einspritzventilen bzw. Einspritzaktoren eine minimale, raildruckabhängige Ansteuerspannung erforderlich ist, um eine wirksame Einspritzung zu realisieren. Wird der Einspritzaktor allerdings mit einer geringeren Spannung beaufschlagt, so reicht die dadurch erzeugte Kraft nicht aus, um das Steuerventil gegen den Raildruck zu öffnen.The invention is based, in particular, on the effect which is known per se, that in the injection valves or injection actuators concerned here, a minimum, rail pressure-dependent activation voltage is required in order to realize an effective injection. However, if the injection actuator is subjected to a lower voltage, then the force generated thereby is insufficient to open the control valve against the rail pressure.

Der Erfindung liegt auch die Erkenntnis zugrunde, dass bei sukzessiver Erhöhung der Ansteuerspannung eine Einspritzung instantan einsetzt, sobald die Ansteuerspannung ausreichend groß ist. D.h. es existiert eine scharfe Trennung hinsichtlich der Systemreaktion bzgl. einer zu kleinen/ausreichenden Ansteuerspannung. Das vorgeschlagene Verfahren macht sich diese Eigenschaft zu Nutze, indem die im Betrieb der Brennkraftmaschine adaptierten Werte der Ansteuerspannung U_erf dazu verwendet werden, Kennlinie(n), Kennfelder oder Tabellen insbesondere der Wertepaare U_erf(p_rail) und/oder U_erf(T_Aktor) mit großer Präzision unter realen Betriebsbedingungen zu ermitteln.The invention is also based on the finding that when the drive voltage is increased successively, an injection starts instantaneously as soon as the drive voltage is sufficiently high. That There is a sharp separation with regard to the system reaction with respect to a too small / sufficient drive voltage. The proposed method makes use of this property by using the values of the drive voltage U_erf adapted during operation of the internal combustion engine with characteristic curve (s), characteristic maps or tables, in particular of the value pairs U_erf (p_rail) and / or U_erf (T_actor), with great precision under real operating conditions.

Ein weiterer Vorteil besteht darin, dass die Ansteuerspannung ohne zusätzlichen sensorischen Aufwand an sich ändernde Betriebsbedingungen der Brennkraftmaschine, insbesondere sich ändernde Zustandsgrößen des Einspritzsystems, adaptiert werden kann, womit sich im Ergebnis eine gegenüber dem Stand der Technik noch präzisere Kraftstoffzumessung ergibt.A further advantage is that the drive voltage can be adapted to changing operating conditions of the internal combustion engine, in particular changing state variables of the injection system, without additional sensory outlay, resulting in an even more precise fuel metering compared to the prior art.

Das Verfahren ermöglicht eine für jedes Einspritzventil bzw. Injektor spezifische und für jeden Verbrennungsraum der Brennkraftmaschine individuelle Adaption der jeweiligen elektrischen Ansteuerspannung bei der Zumessung von Kraftstoff.The method allows a specific for each injector or injector and for each combustion chamber of the internal combustion engine individual adaptation of the respective electrical drive voltage in the metering of fuel.

Die Erfindung betrifft ferner eine Vorrichtung insbesondere zur Ausführung des vorgenannten Verfahrens, welche erste Mittel zur Erfassung der wenigstens einen Zustandsgröße und zur Zwischenspeicherung einer etwa erfassten Zustandsgröße, zweite Mittel zur Ansteuerung des wenigstens einen Einspritzaktors mit einem Ansteuerimpuls vorgebbarer Impulsdauer und vorgebbarer Ausgangsimpulshöhe, dritte Mittel zur Durchführung einer Einspritzerkennung bei der Ansteuerung des wenigstens einen Einspritzaktors, vierte Mittel zur Inkrementierung der Impulshöhe des Ansteuerimpulses in vorgebbaren Schritten bei der vorgegebenen Impulsdauer, sowie fünfte Mittel zur dauerhaften Abspeicherung der Impulshöhe des die Einspritzung bewirkenden Ansteuerimpulses als Funktion der erfassten Zustandsgröße im Falle einer erkannten Einspritzung aufweist.The invention further relates to a device, in particular for carrying out the aforementioned method, comprising first means for detecting the at least one state variable and temporarily storing an approximately detected state variable, second means for controlling the at least one injection actuator with a drive pulse of predefinable pulse duration and predefinable output pulse height, third means for Performing an injection detection in the control of the at least one injection actuator, fourth means for incrementing the pulse height of the drive pulse in predetermined steps at the predetermined pulse duration, and fifth means for permanently storing the pulse height of the injection effecting drive pulse as a function of the detected state variable in the case of a detected injection having.

Die Erfindung wird nachfolgend anhand bevorzugter Ausführungsbeispiele und unter Bezugnahme auf die Zeichnung noch eingehender erläutert, aus denen weitere Merkmale und Vorteile der Erfindung hervorgehen.The invention will be explained in more detail with reference to preferred embodiments and with reference to the drawings, from which further features and advantages of the invention will become apparent.

Im Einzelnen zeigen

Fig. 1
ein vereinfachtes Blockschaltbild eines Einspritzsystems gemäß dem Stand der Technik;
Fig. 2
eine schematische, ausschnittweise Darstellung eines im Stand der Technik bekannten Kraftstoffeinspritzventils für Brennkraftmaschinen im Längsschnitt;
Fig. 3
ein Blockschaltbild einer Einrichtung zum Betrieb eines Common-Rail-Einspritzsystems einer Brennkraftmaschine zur Durchführung des erfindungsgemäßen Verfahrens;
Fig. 4
exemplarische Ansteuerimpulse zur Illustration der Ansteuerung eines Einspritzaktors gemäß der Erfindung; und
Fig. 5
ein bevorzugtes Ausführungsbeispiel der erfindungsgemäßen Prozedur zur Ansteuerung eines Einspritzaktors anhand eines Flussdiagrammes.
Show in detail
Fig. 1
a simplified block diagram of an injection system according to the prior art;
Fig. 2
a schematic, fragmentary view of a known in the art fuel injection valve for internal combustion engines in longitudinal section;
Fig. 3
a block diagram of a device for operating a common rail injection system of an internal combustion engine for carrying out the method according to the invention;
Fig. 4
exemplary drive pulses for illustrating the activation of an injection actuator according to the invention; and
Fig. 5
a preferred embodiment of the procedure according to the invention for controlling an injection actuator based on a flow chart.

Die Fig. 1 zeigt den prinzipiellen Aufbau eines Kraftstoffeinspritzsystems einer selbstzündenden Brennkraftmaschine gemäß dem Stand der Technik ( DE 39 29 747 A1 ). Die hier nur schematisch dargestellte Brennkraftmaschine 10 erhält von einer Einspritzeinheit 30 eine bestimmte Kraftstoffmenge zugemessen. Der momentane Betriebszustand der Brennkraftmaschine 10 wird mittels Sensoren 40 erfasst und die so erfassten Messwerte 15 an ein Steuergerät 20 übermittelt. Diese Messwerte umfassen bspw. die Drehzahl und die Temperatur der Brennkraftmaschine sowie den tatsächlichen Einspritzbeginn und evtl. noch weitere Größen 25, die den Betriebszustand der Brennkraftmaschine charakterisieren, wie bspw. die Stellung eines Fahrpedals 25 oder der Umgebungsluftdruck. Das Steuergerät 20 berechnet anhand der Messwerte 15 und der weiteren Größen 25 entsprechend der vom Fahrer gewünschten Kraftstoffmenge Ansteuerimpulse 35, mit denen ein mengenbestimmendes Glied der Einspritzeinheit 30 beaufschlagt wird. Als mengenbestimmendes Glied dient dort ein Magnetventil, welches so angeordnet ist, dass durch die Öffnungsdauer bzw. die Schließdauer des Magnetventils die einzuspritzende Kraftstoffmenge festgelegt wird. Allerdings ist anzumerken, dass anstelle von Magnetventilen auch andere elektrisch steuerbare Einspritzventile mit bspw. Piezo-Aktoren angeordnet sein können. Das nachfolgend beschriebene Verfahren ist davon jedoch unberührt.The Fig. 1 shows the basic structure of a fuel injection system of a self-igniting internal combustion engine according to the prior art ( DE 39 29 747 A1 ). The internal combustion engine 10 shown here only schematically receives a certain amount of fuel from an injection unit 30. The instantaneous operating state of the internal combustion engine 10 is detected by means of sensors 40 and the measured values 15 thus acquired are transmitted to a control unit 20. These measured values include, for example, the speed and the temperature of the internal combustion engine as well as the actual start of injection and possibly even further variables 25 which characterize the operating state of the internal combustion engine, such as the position of an accelerator pedal 25 or the ambient air pressure. Based on the measured values 15 and the further variables 25, the control unit 20 calculates drive pulses 35 corresponding to the fuel quantity desired by the driver, with which a quantity-determining element of the injection unit 30 is acted upon. As a quantity-determining member there is a solenoid valve which is arranged so that the amount of fuel to be injected is determined by the opening duration or the closing time of the solenoid valve. However, it should be noted that instead of solenoid valves and other electrically controllable injectors with eg. Piezo actuators may be arranged. However, the method described below is unaffected.

Das (nicht gezeigte) Magnetventil ist insoweit nachteilig, als sich bei identischem Ansteuerimpuls unterschiedliche Schließzeiten ergeben können und daher bei gleicher Zeitdauer des Ansteuerimpulses und sonst gleichen Betriebsparametern unterschiedliche Kraftstoffmengen eingespritzt werden. Da die Ansteuerimpulse insbesondere bei Voreinspritzungen üblicherweise sehr kurz sind, kann nun der Fall eintreten, dass bei einzelnen Magnetventilen keine Voreinspritzung erfolgt oder die Voreinspritzung so stark wird, dass sich die Abgaswerte der Brennkraftmaschine verschlechtern.The (not shown) solenoid valve is disadvantageous insofar as different closing times can result with identical drive pulse and therefore different amounts of fuel are injected at the same time duration of the drive pulse and otherwise the same operating parameters. Since the drive pulses are usually very short, in particular during pilot injections, it may now be the case that no pilot injection takes place in the case of individual solenoid valves or the pilot injection becomes so strong that the exhaust gas values of the internal combustion engine deteriorate.

In der Fig. 2 ist ein im Stand der Technik ( DE 100 02 270 C1 ) bekanntes, piezoelektrisch steuerbares Einspritzventil 101 in einer Schnittzeichnung dargestellt. Das Ventil 101 weist einen piezoelektrischen Aktor 104 zur Betätigung eines in einer Bohrung 113 eines Ventilkörpers 107 axial verschiebbaren Ventilglieds 103 auf. Das Ventil 101 weist ferner einen an den piezoelektrischen Aktor 104 angrenzenden Stellkolben 109 sowie einen an ein Ventilschließglied 115 angrenzenden Betätigungskolben 114 auf. Zwischen den Kolben 109, 114 ist eine als hydraulische Übersetzung arbeitende Hydraulikkammer 116 angeordnet. Das Ventilschließglied 115 wirkt mit wenigstens einem Ventilsitz 118, 119 zusammen und trennt einen Niederdruckbereich 120 von einem Hochdruckbereich 121. Eine nur schematisch angedeutete elektrische Steuereinheit 112 liefert die Ansteuerspannung für den piezoelektrischen Aktor 104 in Abhängigkeit insbesondere des Druckniveaus im Hochdruckbereich 121.In the Fig. 2 is a in the art ( DE 100 02 270 C1 ) known, piezoelectrically controllable injection valve 101 shown in a sectional drawing. The valve 101 has a piezoelectric actuator 104 for actuating a valve member 103 axially displaceable in a bore 113 of a valve body 107. The valve 101 also has an actuating piston 109 adjoining the piezoelectric actuator 104 and an actuating piston 114 adjoining a valve closing member 115. Between the pistons 109, 114 a working as a hydraulic ratio hydraulic chamber 116 is arranged. The valve closure member 115 cooperates with at least one valve seat 118, 119 and separates a low-pressure region 120 from a high-pressure region 121. An electrical control unit 112, indicated only schematically, supplies the drive voltage for the piezoelectric actuator 104 as a function of, in particular, the pressure level in the high-pressure region 121.

Die in der Fig. 3 gezeigte Einrichtung zum Betrieb eines Common-Rail-Einspritzsystems einer Brennkraftmaschine umfasst ein sogenanntes Freigabemodul 200, welches in dem Ausführungsbeispiel mittels eines von einem nicht gezeigten Steuergerät bereitgestellten Schub-Bits 205 freischaltbar ist. Dadurch ist gewährleistet, dass die erfindungsgemäße Prozedur ausschließlich im Schubbetrieb der Brennkraftmaschine durchgeführt wird. Mögliche weitere Eingangsgrößen des Freigabemoduls sind der momentane Raildruck und/oder die momentane Temperatur des Piezo-Aktors. Mittels dieser weiteren Größen kann erreicht werden, dass die Prozedur nur bei Vorliegen eines stationären Betriebszustandes des Einspritzsystems durchgeführt wird, wodurch die Genauigkeit der letztlich zu ermittelenden Ansteuerspannung wesentlich erhöht werden kann. Um den Raildruck während der Ausführung der Prozedur möglichst konstant zu halten, ist ferner eine Raildruck-Regelung 210 angeordnet, deren Betrieb durch das Freigabemodul 200 getriggert wird. Entsprechend getriggert wird auch ein Funktionsmodul 215 zur erfindungsgemäßen Ansteuerung der Einspritzaktoren und nachfolgenden Adaption der Ansteuersignale. Ein weiteres Eingangssignal 220 des zuletzt genannten Funktionsmoduls 215 wird in dem vorliegenden Ausführungsbeispiel von einem Drehzahlsignal-Auswertemodul 225 bereitgestellt, welches anhand eines vom Steuergerät bereitgestellten Drehzahlsignals eine Einspritzerkennung durchführt.The in the Fig. 3 The device shown for operating a common-rail injection system of an internal combustion engine comprises a so-called release module 200, which in the exemplary embodiment can be unlocked by means of a push bit 205 provided by a control unit, not shown. This ensures that the procedure according to the invention is carried out exclusively in overrun operation of the internal combustion engine. Possible further input variables of the release module are the current rail pressure and / or the instantaneous temperature of the piezo actuator. By means of these further variables can be achieved that the procedure is carried out only in the presence of a stationary operating state of the injection system, whereby the accuracy of the ultimately to be determined driving voltage can be substantially increased. In order to keep the rail pressure as constant as possible during the execution of the procedure, a rail pressure control 210 is also arranged, the operation of which is triggered by the release module 200. A function module 215 for triggering the injection actuators according to the invention and subsequent adaptation of the activation signals is triggered accordingly. Another input signal 220 of the last-mentioned function module 215 is provided in the present exemplary embodiment by a speed signal evaluation module 225, which performs an injection recognition on the basis of a speed signal provided by the control unit.

In der Fig. 4 sind typische Ansteuerspannungsimpulse dargestellt, um die schrittweise Erhöhung der Ansteuerspannung bei konstanter Ansteuerdauer zu verdeutlichen. Der erste Spannungsimpuls 400 unterscheidet sich von dem zweiten Spannungsimpuls 405 nur durch das gezeigte Spannungsinkrement ΔU1, wobei die gezeigte mittlere Impulsdauer Δt1 bei beiden Spannungsimpulsen übereinstimmt.In the Fig. 4 are typical Ansteuerspannungsimpulse shown to illustrate the stepwise increase of the drive voltage at a constant drive time. The first voltage pulse 400 differs from the second voltage pulse 405 only by the shown voltage increment .DELTA.U1, wherein the shown average pulse duration .DELTA.t1 coincides in both voltage pulses.

Bei dem in der Fig. 5 gezeigten bevorzugten Ausführungsbeispiel einer erfindungsgemäßen Prozedur wird angenommen, dass eine Ansteuerung eines einzelnen Einspritzaktors bzw. Injektors vorgenommen wird. Zusätzlich wird angenommen, dass die nachfolgenden Schritte mittels des bereits genannten Freigabemoduls 500 ausschließlich im Schubbetrieb der Brennkraftmaschine ausgeführt werden.In the in the Fig. 5 In the preferred embodiment of a procedure according to the invention shown, it is assumed that an activation of a single injection actuator or injector is undertaken. In addition, it is assumed that the subsequent steps are carried out by means of the already mentioned release module 500 exclusively in overrun operation of the internal combustion engine.

Im gezeigten Schritt 505 wird zunächst geprüft, ob eine Freigabe zur Adaption der Ansteuerspannung der Einspritzaktoren erfolgt ist. Ist diese Freigabe nicht erfolgt, wird die Adaption nicht durchgeführt 510. Wird die Adaption freigegeben, wird im nachfolgenden Schritt 515 geprüft, ob der Raildruck mittels der genannten Raildruck-Regelung 210 bereits auf einen innerhalb vorgebbarer Schranken liegenden Wert eingeregelt ist. Ist die Einregelung noch nicht abgeschlossen, wird zu Schritt 505 zurückgesprungen. Andernfalls erfolgt eine Ansteuerung 520 eines einzelnen Einspritzventils bzw. Injektors vorgenommen und dessen Piezo-Aktor zunächst mit einer Spannung U_min beaufschlagt, welche so gewählt ist, dass in dem Injektor noch keine Einspritzung erfolgt. D.h. die Höhe der Spannung U_min ist so bemessen, dass sie noch nicht ausreicht, um bei dem im Rail vorherrschenden Raildruck das Steuerventil zu öffnen und eine Einspritzung zu bewirken. Die genannte Ansteuerung 520 erfolgt dabei mit einer vorgegebenen festen Ansteuerdauer AD = const.In the step 505 shown, it is first checked whether a release for adaptation of the drive voltage of the injection actuators has taken place. If this release is not carried out, the adaptation is not carried out 510. If the adaptation is enabled, it is checked in the subsequent step 515 whether the rail pressure has already been adjusted by means of the mentioned rail pressure control 210 to a value which can be set within predeterminable limits. If the adjustment has not yet been completed, the system returns to step 505. Otherwise, a control 520 of a single injection valve or injector is carried out and its piezo actuator is initially acted upon by a voltage U_min, which is selected so that no injection takes place in the injector. That the magnitude of the voltage U_min is such that it is not yet sufficient to open the control valve at the rail pressure prevailing in the rail and to effect an injection. The aforementioned drive 520 takes place with a predetermined fixed drive time AD = const.

Während der beschriebenen und der nachfolgenden Ansteuerungen wird jeweils die Systemreaktion, d.h. das Erfolgen einer Einspritzung in den dem angesteuerten Injektor zugeordneten Verbrennungsraum der Brennkraftmaschine, überwacht 525. In dem vorliegenden Ausführungsbeispiel erfolgt dies mittels des bereits genannten Drehzahlsignalauswertemoduls 225. Wird eine Einspritzung erkannt, wird die dafür ursächliche Ansteuerspannung U_erf zusammen mit dem aktuell vorliegenden Wert des Raildrucks dauerhaft abgespeichert 530. Im Falle jedoch, dass keine Einspritzung erkannt wird, wird die Ansteuerspannung solange schrittweise inkrementiert 535 und danach jeweils das Drehzahlsignal überwacht, bis eine momentenbildende und damit drehzahlerhöhende Einspritzung erkannt wird 525. Die dann zugrundeliegende Ansteuerspannung U_erf wird zusammen mit dem Raildruckwert entsprechend abgespeichert 530.During the described and subsequent activations, the system reaction, ie the success of an injection in the combustion chamber of the internal combustion engine assigned to the controlled injector, is monitored 525. In the present exemplary embodiment, this takes place by means of the above-mentioned speed signal evaluation module 225. If an injection is detected, the for this causal control voltage U_erf together with the currently present value of the rail pressure permanently stored 530. In the case, however, that no injection detected is, the drive voltage is gradually incremented 535 and then each monitored the speed signal until a torque-forming and thus speed-increasing injection is detected 525. The then underlying drive voltage U_erf is stored 530 together with the rail pressure value.

Die in der Fig. 5 gezeigte Prozedur wird in dem Ausführungsbeispiel bei unterschiedlichen Raildrücken ausgeführt und dadurch die Erfassung einer Kennlinie U_erf(p_Rail) ermöglicht. Die Feinheit der vorbeschriebenen Inkremente der Ansteuerspannung bestimmt wesentlich die erreichbare Streuung der ermittelten Kennlinienwerte und damit letztlich die maximal erreichbare Präzision bei der Kraftstoffzumessung. Die so ermittelten Werte der Ansteuerspannung stellen jeweils Mindestspannungen dar, welche bei dem aktuellen Raildruck zu einer Aktorbewegung und damit zu einer mittelbar messbaren Einspritzung führen.The in the Fig. 5 In the embodiment shown, the procedure shown is carried out at different line pressures, thereby enabling the detection of a characteristic curve U_erf (p_Rail). The fineness of the above-described increments of the drive voltage essentially determines the achievable scattering of the determined characteristic values and thus ultimately the maximum achievable precision in the fuel metering. The values of the drive voltage determined in this way each represent minimum voltages which lead to an actuator movement and thus to an indirectly measurable injection at the current rail pressure.

Die vorbeschriebene Prozedur kann ferner bei allen Verbrennungsräumen (Zylindern) der Brennkraftmaschine angewendet werden. Dabei kann es erforderlich sein, den Raildruck im Schubbetrieb auf einen Wert zu regeln, der vom üblicherweise in dem betreffenden Betriebspunkt der Brennkraftmaschine herrschenden Raildruck abweicht. Demzufolge wird auch der erreichbare Raildruckbereich nach oben hin begrenzt sein, so dass die Adaption nur innerhalb eines begrenzten Raildruckbereiches durchgeführt werden kann und eine Extrapolation für den übrigen Raildruckbereich erfolgen muss.The above-described procedure may be further applied to all combustion chambers (cylinders) of the internal combustion engine. It may be necessary to control the rail pressure in overrun to a value that differs from the prevailing at the relevant operating point of the internal combustion engine rail pressure. Consequently, the achievable rail pressure range will be limited to the top, so that the adaptation can be performed only within a limited rail pressure range and an extrapolation must be made for the rest of the rail pressure range.

In einem anderen Ausführungsbeispiel wird der jeweils ermittelte Wert der Ansteuerspannung mit vorab empirisch festgelegten Sollspannungswerten verglichen und aus der ggf. sich ergebenden Differenz ein Korrekturwert bestimmt.In another exemplary embodiment, the respectively determined value of the drive voltage is compared with predetermined voltage values determined in advance empirically and a correction value is determined from the possibly resulting difference.

In einem weiteren Ausführungsbeispiel erfolgt die Ablage der ermittelten Werte der Ansteuerspannung in der Kennlinie gefiltert. Wenn bspw. der Raildruck den bei der Kennlinie zugrundegelegten, gerade aktiven Druckbereich verlässt, wird der jeweils neu adaptierte Wert der Ansteuerspannung vor der Ablage mit dem alten Spannungswert gefiltert, insbesondere mit diesem gewichtet, womit der Einfluss von Messstörungen bei der Erstellung der Kennlinie verringert wird.In a further embodiment, the storage of the determined values of the drive voltage is filtered in the characteristic curve. If, for example, the rail pressure leaves the currently active pressure range which is the basis of the characteristic curve, the respectively newly adapted value of the drive voltage before filing is filtered with the old voltage value, in particular weighted therewith, whereby the influence of measurement disturbances in the generation of the characteristic curve is reduced ,

Wie bereits erläutert, erfolgt die genannte Einspritzerkennung mittelbar anhand von Betriebskenngrößen der Brennkraftmaschine. Auf die dabei zugrunde gelegte Betriebskenngröße kommt es allerdings nicht an. Eine bevorzugte Betriebskenngröße ist, wie vorbeschrieben, die Drehzahl bzw. der Wert eines von der Brennkraftmaschine bzw. einem entsprechenden Motorsteuergerät bereitgestellten Drehzahlsignals. Daneben kommen andere im Steuergerät bereits vorliegende Größen wie bspw. das von einem Brennraumdrucksensor bereitgestellte Drucksignal, das von einem im Verbrennungsraum angeordneten Klopfsensor bereitgestellte Klopfsignal oder das von einem Ionenstromsensor bereitgestellt Ionenstromsignal in Betracht.As already explained, the said injection recognition takes place indirectly on the basis of operating parameters of the internal combustion engine. However, it does not depend on the underlying operating characteristic. A preferred operating parameter is, as described above, the speed or the value of a speed signal provided by the internal combustion engine or a corresponding engine control unit. In addition, other variables already present in the control unit, such as the pressure signal provided by a combustion chamber pressure sensor, the knock signal provided by a knock sensor arranged in the combustion chamber or the ion current signal provided by an ion current sensor, are considered.

In einem weiteren Ausführungsbeispiel wird die Größe der bei dem beschriebenen Verfahren fest vorgegebenen Ansteuerdauer so gewählt, dass bei dem aktuellen Raildruck maximal eine Einspritzmenge realisiert wird, die für den Fahrer des zugrundeliegenden Fahrzeuges nicht spürbar ist, so dass sich durch die vorbeschriebene Adaptionsprozedur keine Komforteinbuße einstellt.In a further embodiment, the size of the drive duration permanently predetermined in the described method is selected such that at the current rail pressure a maximum of one injection quantity is realized which is not noticeable to the driver of the underlying vehicle, so that no loss of comfort occurs due to the above-described adaptation procedure ,

Es ist anzumerken, dass die vorbeschriebene Kennlinie U_erf(p_Rail) nur beispielhaft ist und andere Kenngrößenpaare wie bspw. die Ansteuerspannung 'U_erf' über der Aktortemperatur ,T_Piezo-Aktor' zugrundegelegt werden können. Zudem wird das vorbeschriebene Einspritzsystem mit einem piezoelektrisch gesteuerten Einspritzaktor nur als Ausführungsbeispiel verstanden und kann bspw. auch magnetisch gesteuerte Aktoren oder dgl. umfassen.It should be noted that the above-described characteristic curve U_erf (p_Rail) is only an example and other parameter pairs such as, for example, the control voltage 'U_erf' can be used as the basis for the actuator temperature 'T_Piezo actuator'. In addition, the above-described injection system with a piezoelectrically controlled injection actuator is only understood as an exemplary embodiment and may, for example, also include magnetically controlled actuators or the like.

Das vorbeschriebene Verfahren ist in einem in der Fig. 1 gezeigten Steuergerät in Form einer Programmroutine oder in Form von separaten Steuerungselementen einer entsprechenden Vorrichtung implementierbar. Die programmtechnischen Details einer solchen Implementierung sind dem einschlägigen Fachmann in Kenntnis des Vorstehenden geläufig und werden daher hier nicht näher erläutert.The above-described method is in a in the Fig. 1 can be implemented in the form of a program routine or in the form of separate control elements of a corresponding device. The program-technical details of such an implementation are familiar to those skilled in the knowledge of the above and are therefore not explained here.

Claims (15)

  1. Method for operating a common-rail injection system of an internal combustion engine (10), with at least one injection actuator (104) controllable by means of activation pulses, the activation (215) of the injection actuator (104) being carried out on the basis of at least one state variable of the common-rail injection system, characterized in that the at least one state variable is detected and intermediately stored, in that the at least one injection actuator (104) is activated (520) by means of an activation pulse of predeterminable pulse duration and of predeterminable output pulse height, in that, during the activation (520) of the at least one injection actuator (104), injection detection is carried out (525), in that, during subsequent activations, the pulse height of the activation pulse is incremented (535) in predeterminable steps, with the pulse duration being permanently predetermined, until an injection is detected (525), and in that, in the event of a detected injection, the pulse height of the activation pulse causing the injection is permanently stored (530) as a function of the detected state variable and is taken as a basis, in the future operation of the common-rail injection system, for the activation of the at least one injection actuator.
  2. Method according to Claim 1, characterized in that the pulse height of the activation pulse causing an injection is permanently stored as a function of the detected state variable of the common-rail system only when the state variable varies (515) only within a predeterminable fluctuation width in the time interval considered.
  3. Method according to Claim 1 or 2, characterized in that the output pulse height of the activation pulse is selected (400) such that, at the instantaneous value of the state variable, still no injection takes place.
  4. Method according to one of the preceding claims, characterized in that the said steps are carried out in the case of at least two different values of the state variable, and the pulse height, resulting in each case, of the activation pulse causing an injection is permanently stored as a function of the respective value of the state variable in a table, a characteristic map or a characteristic curve, and the table or the characteristic map or the characteristic curve is taken as a basis, in the future operation of the common-rail injection system, for the activation of the at least one injection actuator.
  5. Method according to Claim 4, characterized in that the pulse height of the activation pulse causing an injection is stored, in a filtered or weighted form, as a function of the respective value of the state variable in the table or the characteristic map or the characteristic curve.
  6. Method according to one of the preceding claims, characterized in that the state variable of the common-rail injection system is formed by the rail pressure prevailing instantaneously in the common-rail injection system or by the temperature prevailing instantaneously in the common-rail injection system or by exemplary dispersions of the common-rail injection system or of its components.
  7. Method according to one of the preceding claims, characterized in that the said steps are carried out (500-510) only in the overrun mode of the internal combustion engine.
  8. Method according to one of the preceding claims, characterized in that injection detection takes place indirectly on the basis of operating characteristics of the internal combustion engine, specifically, preferably, on the basis of a rotational speed signal and/or of a combustion-space pressure signal and/or of a knock signal and/or of an ion-current signal of the internal combustion engine.
  9. Method according to one of the preceding claims, characterized in that the said steps are carried out cyclically for all the combustion spaces of the internal combustion engine.
  10. Method according to one of the preceding claims, characterized in that the determined values of the pulse height of the activation pulse causing an injection are compared with predeterminable desired values and, from a deviation resulting in this case, a correcting variable is determined, by means of which the common-rail injection system is operated in future.
  11. Method according to one of the preceding claims, characterized in that the pulse duration of the activation pulses is selected such that, at the present value of the state variable, an injection quantity is implemented which ensures that as little influence as possible is exerted on the operation of the internal combustion engine.
  12. Device for controlling a common-rail injection system of an internal combustion engine (10), the common-rail injection system having at least one injection actuator (104) controllable by means of activation pulses, and the activation (215) of the injection actuator (104) being carried out on the basis of at least one state variable of the common-rail injection system, characterized by first means which detect and intermediately store the at least one state variable, second means (520) which activate the at least one injection actuator (104) by means of an activation pulse of predeterminable pulse duration and of predeterminable output pulse height, third means (525) which, during the activation (520) of the at least one injection actuator (104), carry out injection detection, fourth means (535) which, during subsequent activations, increment the pulse height of the activation pulse in predeterminable steps, with the pulse duration being permanently predetermined, until an injection is detected, and fifth means (530) which, in the event of a detected injection, permanently store the pulse height of the activation pulse causing the injection, as a function of the detected state variable, in order to take the said pulse height as a basis, in the future operation of the common-rail injection system, for the activation of the at least one injection actuator.
  13. Device according to Claim 12, characterized in that the fifth means (530) comprise a comparator, by means of which a check is made as to whether the state variable varies within a predeterminable fluctuation width in the time interval considered, the pulse height of the activation pulse causing an injection being permanently stored as a function of the detected state variable of the common-rail system only when the comparator establishes that the state variable actually varies within the predeterminable fluctuation width in the time interval considered.
  14. Device according to Claim 12 or 13, characterized in that the fifth means (530) have at least one table, one characteristic map or one characteristic curve for the permanent storage of the pulse height of the activation pulse causing the injection, as a function of the detected state variable, which table, characteristic map or characteristic curve is taken as a basis, in the future operation of the common-rail injection system, for the activation of the at least one injection actuator.
  15. Device according to one of Claims 12 to 14, characterized by sixth means (500-510) for detecting an overrun mode of the internal combustion engine.
EP03767399A 2002-11-25 2003-11-04 Method and device for operating an injection system in an internal combustion engine Expired - Lifetime EP1567758B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10254844A DE10254844A1 (en) 2002-11-25 2002-11-25 Method and device for operating an injection system of an internal combustion engine
DE10254844 2002-11-25
PCT/DE2003/003647 WO2004048763A1 (en) 2002-11-25 2003-11-04 Method and device for operating an injection system in an internal combustion engine

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EP1567758B1 true EP1567758B1 (en) 2008-02-13

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US (1) US7191051B2 (en)
EP (1) EP1567758B1 (en)
JP (1) JP2006507443A (en)
CN (1) CN100379965C (en)
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WO (1) WO2004048763A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005008179A1 (en) * 2005-02-23 2006-08-31 Robert Bosch Gmbh Operating method for injector of internal combustion engine involves monitoring system, which monitors whether control member is controlled outside of projected fuel injection and measure is executed depending upon result of monitoring
DE102006015967A1 (en) * 2006-04-05 2007-10-18 Siemens Ag Adaptation method of an injection system of an internal combustion engine
DE102006027405B3 (en) * 2006-06-13 2007-12-13 Siemens Ag Method for operating an internal combustion engine and internal combustion engine
FR2917463A3 (en) * 2007-06-12 2008-12-19 Renault Sas Injector drift correcting method for e.g. oil engine of automobile, involves determining correction with nominal control voltage setpoint of each injector, by utilizing estimation of indicated average torque of each cylinder
DE102007034188A1 (en) * 2007-07-23 2009-01-29 Robert Bosch Gmbh Method for operating an injection valve
DE102010021168B4 (en) * 2010-05-21 2020-06-25 Continental Automotive Gmbh Method for operating an internal combustion engine and internal combustion engine
DE102011007359B4 (en) * 2011-04-14 2019-08-01 Robert Bosch Gmbh Method and device for operating a piezoelectric actuator
DE102011087961A1 (en) 2011-12-08 2013-06-13 Robert Bosch Gmbh Method for learning a minimum activation duration of injection valves of an internal combustion engine
DE102012209965A1 (en) * 2012-06-14 2013-12-19 Robert Bosch Gmbh Method for operating a valve

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4889100A (en) * 1986-12-19 1989-12-26 Japan Electronic Control Systems Company, Limited Fuel injection control system for multi-cylinder internal combustion engine with feature of improved response characteristics to acceleration enrichment demand
DE3929747A1 (en) 1989-09-07 1991-03-14 Bosch Gmbh Robert METHOD AND DEVICE FOR CONTROLLING FUEL INJECTION
US5546909A (en) * 1994-12-27 1996-08-20 Ford Motor Company Method and system for generating a fuel pulse waveform
US5638798A (en) * 1996-03-25 1997-06-17 Ford Motor Company Method and system for generating ignition coil control pulses
US5732381A (en) * 1996-03-25 1998-03-24 Ford Motor Company Method and system for generating a fuel pulse waveform
US6076503A (en) * 1996-12-13 2000-06-20 Tecumseh Products Company Electronically controlled carburetor
DE19905340C2 (en) 1999-02-09 2001-09-13 Siemens Ag Method and arrangement for presetting and dynamic tracking of piezoelectric actuators
DE10002270C1 (en) 2000-01-20 2001-06-28 Bosch Gmbh Robert Valve for controlling liquids has electronic control unit that defines piezoelectric valve element actuating unit drive voltage depending on leakage loss in low pressure region
DE60019262T2 (en) 2000-04-01 2006-01-19 Robert Bosch Gmbh fuel injection system
DE10032022B4 (en) 2000-07-01 2009-12-24 Robert Bosch Gmbh Method for determining the drive voltage for an injection valve with a piezoelectric actuator

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US7191051B2 (en) 2007-03-13
EP1567758A1 (en) 2005-08-31
DE10254844A1 (en) 2004-06-03
WO2004048763A1 (en) 2004-06-10
US20060129302A1 (en) 2006-06-15
JP2006507443A (en) 2006-03-02
CN1692219A (en) 2005-11-02
CN100379965C (en) 2008-04-09

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