CN109322756B - Method for determining the quantity of fuel discharged by a fuel injector - Google Patents
Method for determining the quantity of fuel discharged by a fuel injector Download PDFInfo
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- CN109322756B CN109322756B CN201810859598.8A CN201810859598A CN109322756B CN 109322756 B CN109322756 B CN 109322756B CN 201810859598 A CN201810859598 A CN 201810859598A CN 109322756 B CN109322756 B CN 109322756B
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- 239000000446 fuel Substances 0.000 title claims abstract description 144
- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000002485 combustion reaction Methods 0.000 claims abstract description 17
- 238000002347 injection Methods 0.000 claims description 27
- 239000007924 injection Substances 0.000 claims description 27
- 238000004590 computer program Methods 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 2
- 238000007789 sealing Methods 0.000 description 11
- 230000006870 function Effects 0.000 description 6
- 230000005489 elastic deformation Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 125000000524 functional group Chemical group 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 230000015654 memory Effects 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
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- 239000000969 carrier Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
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- 239000002245 particle Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
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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
- F02D41/30—Controlling fuel injection
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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
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/3809—Common rail control systems
- F02D41/3836—Controlling the fuel pressure
- F02D41/3863—Controlling the fuel pressure by controlling the flow out of the common rail, e.g. using pressure relief valves
- F02D41/3872—Controlling the fuel pressure by controlling the flow out of the common rail, e.g. using pressure relief valves characterised by leakage flow in injectors
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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
- F02D41/2474—Characteristics of sensors
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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
- F02D41/30—Controlling fuel injection
- F02D41/3005—Details not otherwise provided for
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M57/00—Fuel-injectors combined or associated with other devices
- F02M57/005—Fuel-injectors combined or associated with other devices the devices being 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
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
- F02D2041/1413—Controller structures or design
- F02D2041/1432—Controller structures or design the system including a filter, e.g. a low pass or high pass filter
-
- 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
- F02D41/26—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor
- F02D41/28—Interface circuits
- F02D2041/286—Interface circuits comprising means for signal processing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/06—Fuel or fuel supply system parameters
- F02D2200/0602—Fuel pressure
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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
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/06—Fuel or fuel supply system parameters
- F02D2200/0614—Actual fuel mass or fuel injection amount
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/06—Fuel or fuel supply system parameters
- F02D2200/0614—Actual fuel mass or fuel injection amount
- F02D2200/0616—Actual fuel mass or fuel injection amount determined by estimation
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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
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/06—Fuel or fuel supply system parameters
- F02D2200/0618—Actual fuel injection timing or delay, e.g. determined from fuel pressure drop
-
- 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
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- Fuel-Injection Apparatus (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
The invention relates to a method for determining a quantity (Q) of fuel discharged by a fuel injector for an internal combustion engine by means of a sensor which is provided for detecting the opening and/or closing of the fuel injector, wherein a signal profile of the sensor is detected during the operation of the fuel injector, and wherein a parameter (M) which is characteristic for the signal profile is referenced 5 ) Using the value (M) of said characteristic parameter 5 ) -determining the amount of fuel discharged by the fuel injector (10) in case of a relation (F) to the amount of fuel discharged (Q).
Description
Technical Field
The present invention relates to a method for determining a quantity of fuel discharged by a fuel injector for an internal combustion engine, as well as to a computing unit and a computer program for the execution thereof.
Background
Modern internal combustion engines have fuel injectors with which fuel can be introduced into the combustion chamber in a targeted manner. For precise control of the internal combustion engine and compliance with emission and power requirements, it is advantageous to detect the characteristic times of the injection process (in particular, the opening and closing of the injection valve of the fuel injector and thus the start and end of the injection) or the quantity of fuel discharged as precisely as possible.
In the case of fuel injectors, in which opening and closing are performed directly by solenoid valves, piezo actuators, etc., the electrical actuation quantity itself can generally be used for detecting the time of this type of indication.
In contrast, in the case of so-called servo injectors, in which a servo valve is first actuated in order to actuate an injection nozzle, there is no direct relationship between the electrical actuation variable and the opening or closing time of the fuel injector or its nozzle needle. In the case of such a fuel injector, therefore, additional sensors can be used which detect, for example, the fuel pressure in the control chamber of the fuel injector or deformations of the fuel injector due to pressure changes, in particular in the region of its high-pressure bore.
A method for determining the time of this characterizing feature is known, for example, from EP 2 944 799 A1, in which such a sensor is mounted on a retaining body of the fuel injector, and its sensor signal substantially reproduces a deformation of the retaining body in the region of a high-pressure bore which extends through the retaining body below this sensor. In this case, the start of injection can preferably be determined with reference to the time position of the minimum of the second derivative of the sensor signal, whereas the end of injection can be determined with reference to the time position of the maximum of the first derivative of the sensor signal.
The detection quality is then often significantly impaired by interference signals, which are superimposed on the actual sensor signal, in particular at the start of the injection. These interference signals can be triggered by mechanical vibrations of the holding body or also by reflections of the pressure waves, which extend through the high-pressure opening.
For example, it is known from DE 10 2009 027 311 A1 to plot the course of the end-of-injection delay (i.e. the delay of the actual end of the injection relative to the end of the actuation, which is also referred to as the closing duration or closing time) over a actuation duration and to use the parameters characteristic of this curve to determine the start of injection. This is possible because the injection start delay does not depend on the actuation duration but only on the injection pressure. The signal thus obtained is then not sufficiently accurate in terms of the specific type of sensor or fuel injector.
Disclosure of Invention
According to the invention, a method for determining the amount of fuel discharged by a fuel injector, as well as a computing unit and a computer program for carrying out the method are proposed. The method according to the invention is used for determining the quantity of fuel discharged by a fuel injector (that is to say in particular the quantity of fuel injected into a combustion chamber or cylinder by means of this fuel injector) for an internal combustion engine by means of a sensor which is provided for detecting the opening and/or closing of the fuel injector. To this end, during operation of the fuel injector, a signal profile of the sensor is detected and, with reference to a value of a characteristic parameter for the signal profile, the fuel quantity discharged by the fuel injector is determined using a relationship between the value of the characteristic parameter and the discharged fuel quantity. Such a relationship between the value of the characteristic variable and the quantity of fuel discharged can be, in particular, a functional relationship, i.e., a function which maps the value of the characteristic variable to the associated quantity of fuel, or can be a characteristic field or a characteristic curve (determined, for example, in a measurement technique).
In this case, it is conceivable to determine the relationship between the value of the characteristic parameter and the quantity of fuel discharged by the fuel injector by detecting an associated signal profile of the sensor for a plurality of mutually different quantities of fuel discharged by the fuel injector, wherein the associated value of the characteristic parameter is determined for each of the detected signal profiles. A plurality of such value pairs can be determined as the case may be, in order to obtain a suitable function by conventional methods ("Fitting"), for example by polynomial Fitting. However, it is also conceivable to determine only a few (e.g. two pairs) of such value pairs and to start with a linear relationship. This is sufficiently accurate at least for small fuel quantities, as explained in more detail later.
Now, with the proposed method, it is possible to determine the fuel quantity very simply with reference to a sensor signal, which can be understood as a signal generated directly by the sensor or also as a pressure signal obtained therefrom (if necessary, also filtered in each case), and then in particular also to adjust the fuel quantity. Thus, a precise control of the quantity of fuel to be discharged is possible, which is necessary for the best possible operation of the internal combustion engine. It has been recognized here that for different such characteristic parameters there is a direct relationship with the quantity of fuel discharged, as explained in more detail below. In this case, the value of such a characteristic parameter can be determined very simply. An additional, conventional function is no longer necessary, with reference to which the fuel quantity must be determined from further values (e.g., different, characteristic moments or durations),
preferably, at least one of the following values is used as the value of the parameter representing the characteristic:
-the value of the minimum value of the signal profile within a predefined time interval after the start of the actuation of the fuel injector,
-the value of the maximum value of the signal profile within a predefined time interval after the start of the actuation of the fuel injector,
-a value of a difference between the maximum value and the minimum value of the signal profile within a predefined time interval after the start of the actuation of the fuel injector,
-a value of an integral value over the signal profile starting from a control of the fuel injector or from a time with a predefined time distance to the start of the control to its minimum value, and
the value of the integral value over the signal profile from the start of a control of the fuel injector or from a time point with a predetermined time distance to the start of a control to a first zero crossing of the signal profile after its minimum value.
Further, in forming these integrated values, the sensor signals can be corrected by an offset amount (or Bias-value (Bias-Wert)), respectively. The integral value limit can also be shifted by a predetermined offset amount.
All these characteristic parameters can be determined very simply and also precisely with regard to the detected sensor signal, which can be in particular a voltage. In this context, it is also conceivable to use suitable filters (by software and/or hardware). These parameters represent the quantity of fuel injected (said parameters being directly related to the quantity).
For completeness considerations it will be noted that: within the framework of the proposed method, one or more of the mentioned parameters characterizing the characteristics can also be used in order to determine the quantity of fuel discharged separately therefrom and then to obtain more accurate results overall therefrom, for example by forming an average or the like.
Advantageously, the quantity of fuel discharged by the fuel injector is determined with reference to the value of the characteristic parameter, by first correcting the value by an offset, wherein the quantity of fuel discharged by the fuel injector is then determined using the above-mentioned relationship with reference to the corrected value. In this case, it is expedient if, when determining the offset, no fuel is discharged during one or more actuations of the fuel injector by determining the value of the characteristic variable. In addition to the actuation of the discharged fuel, in particular at least one of the actuations of the fuel injector (preferably the first actuation and/or the last actuation during the injection sequence) can be carried out, during which no fuel is discharged. In this way, a particularly fast and accurate determination of the actually discharged fuel quantity is possible, wherein possible deviations have been taken into account. Furthermore, during operation, the adaptation of the offset of the relationship or to be taken into account can also be carried out, so that possible deviations, which occur after a certain operating duration of the fuel injector, can be corrected.
Advantageously, a piezo sensor, a piezoresistive sensor or a capacitive sensor is used as a sensor, in particular, each of which is arranged on a retaining body of the fuel injector. In addition or alternatively, the sensor can also be designed such that the opening and/or closing of the fuel injector can be detected by means of said sensor with reference to a pressure change which occurs in the fuel injector during the respective injection.
In order to detect the pressure course, the sensor can be arranged at a suitable location in the fuel injector, for example at the outer circumference of a retaining body of the fuel injector, in particular at the location of a high-pressure bore. Such a retaining body or its high-pressure bore is subjected to pressure variations in the fuel injector. The pressure change causes an elastic deformation at the holding body in the region of the high-pressure opening. The deformation of the holding body or the line is used as the quantity to be detected by the sensor. The sensors necessary for this purpose can be installed on the retaining body or on the supply line and must be installed neither in the high pressure nor in the low pressure of the fuel injector. Preferably, the sensor is arranged near or above the high-pressure orifice, since the elongation of the holding body is greatest due to the pressure variations at these positions.
Preferably, the fuel injector comprises a servo-valve. This servo valve can preferably be actuated by a piezo actuator or a magnetic actuator. As already mentioned at the outset, the detection of characteristic times of the injection event is difficult precisely with regard to the fuel injector, which is operated by means of a servo valve. However, a better identification is achieved here with the method according to the invention. However, the method according to the invention can also be advantageously used in fuel injectors without a servo valve.
The computing unit according to the invention (for example, a control device of a motor vehicle) is provided in particular in terms of program technology for carrying out the method according to the invention.
The implementation of the method in the form of a computer program is also advantageous, since this results in particularly low costs, in particular if the control device that is executed is also used for further tasks and is thus already present. Suitable data carriers for supplying the computer program are, in particular, magnetic, optical or electrical memories, for example a hard disk, a flash memory, an EEPROM, a DVD, etc. It is also possible to download the program via a computer network (internet, intranet, etc.).
Further advantages and solutions of the invention emerge from the description and the attached drawings.
The present invention is illustrated schematically in the accompanying drawings with reference to embodiments and is described hereinafter with reference to the accompanying drawings.
Drawings
Fig. 1 schematically shows a fuel injector with a sensor, as it can be used in the framework of the method according to the invention.
Fig. 2 and 3 schematically show the control and signal profile with different parameters, as can be used in different preferred embodiments of the method according to the invention.
Fig. 4 schematically shows the relationship between the value of the parameter and the quantity of fuel discharged, in the case of a preferred embodiment of the method according to the invention.
Detailed Description
In fig. 1, a fuel injector with a sensor is schematically shown, as it can be used in the framework of the method according to the invention. Here, the fuel injector 10 can be installed in a combustion chamber (not shown) of an internal combustion engine. The fuel injector 10 is used for injecting or discharging fuel into a combustion chamber of an internal combustion engine, and can be a component of a common rail injection system.
The fuel injector 10 has an injector housing (or retaining body) 11, to which, for example, a nozzle body 12 facing a combustion chamber of the internal combustion engine and a further, fixed-position functional group 13, which is arranged between the nozzle body 12 and the retaining body 11, are connected. The nozzle body 12, the functional group 13 and the retaining body 11 are fixed in a force-transmitting manner (kraftschl ü ssig) in relation to one another by means of a nozzle clamping nut 14.
One or more injection openings 15 are formed in the nozzle body 12. The functional group 13 usually comprises a servo valve, not shown here, and a hydraulic function, also not shown, for transmitting the switching state of the servo valve to the nozzle needle. The holding body 11 usually receives an actuator, which is likewise not shown here, and an associated switching chain for actuating the servo valve by means of the actuator. Since the servo-valves, their embodiments and the construction of the actuators and of the switching chains are not important for the current invention, they are not explicitly shown in the drawings.
Furthermore, a substantially blind-hole-shaped recess 16 is formed in the nozzle body 12, in which recess a nozzle needle 18 is arranged so as to be movable in the axial direction along the longitudinal axis. In the lowered position of the nozzle needle 18 shown in fig. 1, this nozzle needle blocks the injection opening 15 with the sealing seat 19 formed on the inside of the nozzle body 12.
Via the supply channel 30 and the fuel supply line 60, the blind-hole-shaped recess 16 is connected to a fuel high-pressure accumulator (so-called rail) 31.
The nozzle spring 25 exerts an axial force on the nozzle needle 18, which acts in the direction of the sealing seat 19. The pressure in the recess 16 results in a hydraulic force acting on the nozzle needle 18, which is directed away from the sealing seat 19. On the end face of the nozzle needle 18 facing away from the sealing seat 19, a variable pressure exerted thereon generally results in a variable axial force acting on the nozzle needle, which is directed in the direction of the sealing seat 19. The variable pressure and thus the axial force generated by it can be controlled by the switching state of the servo valve. In this way, the servo valve, not shown here, influences the force balance between the opening and closing axial forces at the nozzle needle 18, which is the force balance between the opening and closing axial forces, and thus controls the opening and closing movement thereof.
In the retaining body 11, the conveying channel 30 has two drilled portions 32, 33 whose axes are pivoted at an angle relative to one another. The bore portion 32 extends substantially parallel to the longitudinal axis of the holding body 11, while the second bore portion 33 is inclined in a direction towards the high pressure port 34 of the injector 10. Furthermore, a filter element 36 is usually received in the second bore section 33, which has the task of: the interfering particles are directed away from the fuel injector 10 or are crushed to harmless sizes.
Furthermore, a sensor 50 for detecting the deformation of the holding body, in particular having a piezoelectric element, is now provided in the region of the transport channel 30. Here, the sensor is arranged at an outer peripheral wall of the holder 11. In an advantageous manner, the sensor is arranged directly above the conveying channel 11, particularly advantageously at the level of the intersection of the two bore portions 32, 33. The sensor 50 is connected via suitable electrical connecting lines to a computer unit 80, which is designed as a control device and which is also used at least indirectly for actuating the fuel injector 10.
The functional manner of the fuel injector 10 and of the sensor 50 is explained as follows: in the lowered position of the nozzle needle 18, which is shown in fig. 1, this nozzle needle latches the sealing seat 19. As a result, the fuel is prevented from being discharged through the injection openings 15, and a uniform, substantially constant high pressure (system pressure) is present in the fuel/high-pressure accumulator 31, the fuel supply line 60, the supply channel 30 and in the blind-hole-shaped recess 16.
The actuation of the fuel injector 10 or its actuator causes an upward lifting movement of the nozzle needle 18 via the servo valve, so that the sealing seat 19 is opened. Thereby, fuel flows from the blind hole-shaped recess 16 into the combustion chamber of the internal combustion engine via the injection opening 15. This results in a pressure interruption (Druckeinbruch) in the blind-hole-shaped recess 16 and at the end of the feed channel 30 facing the nozzle body 12. This pressure drop propagates in the direction of the fuel/high-pressure accumulator 31 via the supply duct 30 and the fuel supply line 60 in the form of a pressure wave which has the sound velocity of the fuel. As a result, with a defined time delay after opening the sealing seat 19, a pressure interruption occurs in the delivery channel at the level of the sensor 50, and, as a result, an elastic deformation of the retaining body 11 occurs at this position. This elastic deformation is converted by the sensor into a voltage signal which is usually dropped.
If the actuation of the actuator is ended, the direction of movement of the nozzle needle 18 is thereby reversed and it begins to move in the direction of the sealing seat 19. As soon as the nozzle needle 18 reaches the sealing seat 19, the injection is ended. This results in a pressure increase in the blind-hole-shaped recess 16, which then propagates again in the form of a pressure wave via the supply duct 30 and the fuel supply line 60 to the fuel high-pressure accumulator. As a result, with a defined time delay after closing the sealing seat 19, a pressure rise occurs in the feed channel 30 at the level of the sensor 50, and, as a result, an elastic deformation of the retaining body 11 occurs at this position. This elastic deformation is converted by the sensor into a voltage signal that generally rises.
Fig. 2 and 3 schematically show a control and signal profile of parameters with different characteristics, as can be used in different preferred embodiments of the method according to the invention. For this purpose, in the upper diagram, the actuation current I for the fuel injector or its piezo actuator and (only in fig. 2) the fuel injection rate R are plotted over time t, while in the lower diagram, the associated signal profile of the sensor is shown as voltage U over time t.
Here, in the upper diagram, t AB Indicating the start of the maneuver at t AE Indicates the end of the manipulation, by t EB (in FIG. 2 only) indicates the start of injection, and, with t EE The end of injection is shown (in fig. 2 only). Correspondingly, there is a steering duration Δ t A And duration of opening Δ t O . Injection start delay duration Deltat EV Starting t from the manipulation AB And start of injection t EB The difference between them.
In fig. 2, the signal profile S is shown in the lower diagram, as it can be detected directly, for example, by a sensor. It should be understood that in addition, different filters (both hardware and software filters are possible here), for example low-pass filters, can also be used, in order for example to somewhat flatten the signal profile and to be able to handle it more simply. The thus smoothed signal profile is denoted by S', for example.
Now, the signal change process first arrives with a value M 1 After which it reaches a minimum value having a value of M 2 Is measured. In this case, these values can be used as characteristic variables which are used in the framework of the proposed method for determining the quantity of fuel delivered. For this reason, reference should be made to the following explanations. In addition, with M 3 To represent the difference between the values of the minimum and maximum values.
In addition, with M 4 Represents the integral value which has passed through the signal change process S (or S') from the time t 1 (the time has a time to the beginning of the maneuver t AB At a predetermined time distance, t 1 Can also correspond to t AB ) Time to minimum (t) 2 ) Is obtained by integration of (a).
With M 5 To represent the integral value of the signal change S (or S') from the instant t 1 (the time instant has a time to the beginning of the maneuver t AB At a predetermined time distance, t 1 Can also correspond to t AB ) Starting until a time (t) at a minimum value 2 ) The first zero crossing t of the signal profile 0 Until the time of (c). In this case, these values can also be used for the parameters representing the features, which are used in the framework of the proposed method.
In fig. 3, the actuation profile is again shown, wherein, however, no fuel quantity is output. Nevertheless, a signal profile S can be detected, which is different from zero. By determining the parameter M from this signal variation process 1 To M 5 An offset can be determined in order to correct the value of the characteristic-indicating parameter, which is used to determine the quantity of fuel output.
Fig. 4 schematically shows the relationship between the value of the variable and the quantity of fuel delivered, in a preferred embodiment of the method according to the invention. For this purpose, the value M is plotted, for example, on the quantity of fuel Q delivered 5 As it has been elucidated in more detail with reference to fig. 2. Here, the relationship is represented by F. It should be understood that such a function or such a relationship could also be defined conversely, in order to obtain the quantity of fuel output directly from the value of the parameter.
It can be seen here that for small fuel quantities (here, for example, to 7.5 mm) 3 ) There is a linear relationship between the value and the fuel quantity. In this range, the fuel quantity can thus be determined particularly simply and quickly. However, for larger fuel quantities or values, a relationship can still be established. It is conceivable to adapt or adapt a suitable function to the measured example values.
Furthermore, an offset O can be seen, which shows that the characteristic variable can have a certain value even without a fuel quantity output during the actuation of the fuel injector, as was also explained in detail with reference to fig. 3. This offset O can then be used for the mentioned correction.
Claims (10)
1. Method for determining the quantity (Q) of fuel discharged by a fuel injector (10) for an internal combustion engine by means of a sensor (50), the sensor (50) being provided for detecting the opening and/or closing of the fuel injector (10),
wherein during operation of the fuel injector (10), a signal profile of the sensor (50) is detected and
wherein the quantity of fuel discharged by the fuel injector (10) is determined using a relationship (F) between the characteristic value and the quantity of fuel discharged (Q) with reference to the characteristic value of the parameter for the signal profile,
wherein at least one of the following values is used as the value of the parameter representing the feature:
-a minimum value (M) of the signal profile within a predefined time interval after the start of a control of the fuel injector (10) 1 ) The value of (a) is,
-a maximum value (M) of the signal profile within a predefined time interval after the start of a control of the fuel injector (10) 2 ) The value of (a) is,
-a difference (M) between the maximum and the minimum of the signal profile within a predetermined time interval after the start of the actuation of the fuel injector (10) 3 ) The value of (a) is,
-an integral value (M) at a minimum value of the signal profile from the start of a control of the fuel injector (10) or from a time having a predetermined time distance to the start of the control 4 ) A value of, and
-starting from the actuation of the fuel injector (10) or from a time having a predefined time distance to the start of the actuation to a first zero crossing after a minimum value of the signal profile during the signal profileIntegral value (M) at a point 5 ) The value of (c).
2. Method according to claim 1, wherein the relationship (F) between the value of the characteristic variable and the quantity (Q) of fuel discharged is determined, by detecting the associated signal profile of the sensor (50) for a plurality of different quantities (Q) of fuel discharged by the fuel injector (10) and
wherein the value of the characteristic-representing parameter is determined separately for each of the signal variations.
3. A method according to claim 1, wherein the quantity (Q) of fuel discharged by the fuel injector (10) is determined with reference to the value of the characteristic parameter, by first correcting the value of the characteristic parameter by an offset (O), wherein then with reference to the corrected value of the characteristic parameter, the quantity of fuel discharged by the fuel injector (10) is determined using the relation (F) of the value of the characteristic parameter to the quantity (Q) of fuel discharged.
4. A method according to claim 3, wherein the offset (O) is determined by means of determining the value of the characteristic parameter for one or more manipulations of the fuel injector (10) during which no fuel is discharged.
5. The method according to claim 4, wherein at least one of said manipulations of the fuel injector (10) is performed in addition to a manipulation of discharging fuel, during which no fuel is discharged.
6. Method according to claim 1, wherein a piezo sensor, a piezoresistive sensor or a capacitive sensor is used as sensor (50), the sensor (50) being arranged in each case at a holding body of the fuel injector (10), and/or wherein the opening and/or closing of the fuel injector (10) is detected by means of the sensor (50) with reference to a pressure change which occurs in the fuel injector (10) during the respective injection.
7. The method of claim 1, wherein the fuel injector (10) comprises a servo-valve, the servo-valve being operated by a magnetic-actuator or a piezo-electric actuator.
8. Method according to claim 1, wherein the determined amount of fuel discharged by the fuel injector (10) is used as an actual value for fuel quantity adjustment.
9. A computing unit (80) arranged for performing the method according to any of the preceding claims 1-8.
10. A machine-readable storage medium having stored thereon a computer program causing a computing unit (80) to perform the method according to any of claims 1 to 8, when it is executed on the computing unit (80).
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| DE102017213126.8 | 2017-07-31 | ||
| DE102017213126.8A DE102017213126A1 (en) | 2017-07-31 | 2017-07-31 | A method of determining an amount of fuel delivered by a fuel injector |
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| CN109322756A CN109322756A (en) | 2019-02-12 |
| CN109322756B true CN109322756B (en) | 2023-03-28 |
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| DE102021212338A1 (en) * | 2020-11-11 | 2022-05-12 | Robert Bosch Gesellschaft mit beschränkter Haftung | Method for determining a variable characterizing a flow rate of a fuel injector |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4911131A (en) * | 1986-06-30 | 1990-03-27 | Nissan Motor Company, Limited | Fuel control apparatus for internal combustion engine |
| US5544636A (en) * | 1993-12-16 | 1996-08-13 | Volkswagen Ag | Method for obtaining trigger signals to regulate energy conversion in the combustion chamber of an internal combustion engine |
| US5850820A (en) * | 1995-12-22 | 1998-12-22 | Honda Giken Kogyo Kabushiki Kaisha | Evaporative fuel control system for internal combustion engines |
| CN101526037A (en) * | 2008-01-28 | 2009-09-09 | Gm全球科技运作股份有限公司 | Method for estimating fuel quantity jetted by fuel injector of gas engine |
| RU109506U1 (en) * | 2011-05-16 | 2011-10-20 | Кирилл Владимирович Селиванов | DEVICE FOR DETERMINING PARAMETERS OF THE DIESEL FUEL EQUIPMENT FUEL SUPPLY PROCESS |
| WO2016175757A1 (en) * | 2015-04-28 | 2016-11-03 | Cummins Inc. | Closed-loop adaptive controls from cycle-to-cycle for injection rate shaping |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009027311A1 (en) | 2009-06-30 | 2011-01-05 | Robert Bosch Gmbh | Method for operating an internal combustion engine |
| US9903306B2 (en) * | 2013-02-08 | 2018-02-27 | Cummins Inc. | System and method for acquiring pressure data from a fuel accumulator of an internal combustion engine |
| US9435310B2 (en) * | 2013-03-07 | 2016-09-06 | Cummins Inc. | Hydraulic start-of-injection detecting system and method |
| US9567934B2 (en) * | 2013-06-19 | 2017-02-14 | Enviro Fuel Technology, Lp | Controllers and methods for a fuel injected internal combustion engine |
| DE102014209330A1 (en) | 2014-05-16 | 2015-11-19 | Robert Bosch Gmbh | Device for detecting the fuel pressure for a fuel injector, fuel injector and fuel supply line to a fuel injector |
-
2017
- 2017-07-31 DE DE102017213126.8A patent/DE102017213126A1/en active Pending
-
2018
- 2018-07-31 CN CN201810859598.8A patent/CN109322756B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4911131A (en) * | 1986-06-30 | 1990-03-27 | Nissan Motor Company, Limited | Fuel control apparatus for internal combustion engine |
| US5544636A (en) * | 1993-12-16 | 1996-08-13 | Volkswagen Ag | Method for obtaining trigger signals to regulate energy conversion in the combustion chamber of an internal combustion engine |
| US5850820A (en) * | 1995-12-22 | 1998-12-22 | Honda Giken Kogyo Kabushiki Kaisha | Evaporative fuel control system for internal combustion engines |
| CN101526037A (en) * | 2008-01-28 | 2009-09-09 | Gm全球科技运作股份有限公司 | Method for estimating fuel quantity jetted by fuel injector of gas engine |
| RU109506U1 (en) * | 2011-05-16 | 2011-10-20 | Кирилл Владимирович Селиванов | DEVICE FOR DETERMINING PARAMETERS OF THE DIESEL FUEL EQUIPMENT FUEL SUPPLY PROCESS |
| WO2016175757A1 (en) * | 2015-04-28 | 2016-11-03 | Cummins Inc. | Closed-loop adaptive controls from cycle-to-cycle for injection rate shaping |
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| CN109322756A (en) | 2019-02-12 |
| DE102017213126A1 (en) | 2019-01-31 |
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