Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/20—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
  • F02D41/2451—Methods of calibrating or learning characterised by what is learned or calibrated
  • F02D41/2464—Characteristics of actuators
  • F02D41/2467—Characteristics of actuators for injectors
• • 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
  • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
  • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
  • F02M51/0603—Injectors peculiar thereto with means directly operating the valve needle using piezoelectric or magnetostrictive operating means
• • 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
  • F02D41/20—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
  • F02D2041/2044—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit using pre-magnetisation or post-magnetisation of the coils
• • 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
  • F02D2041/2051—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit using voltage control
• • 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
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/24—Fuel-injection apparatus with sensors
  • F02M2200/244—Force sensors
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/70—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger
  • F02M2200/701—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger mechanical
  • F02M2200/702—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger mechanical with actuator and actuated element moving in different directions, e.g. in opposite directions

Definitions

• Detection method for detecting a gap size of a gap between an injector valve assembly and a piezo stack and driving method for driving an actuator in a piezo stack Detection method for detecting a gap size of a gap between an injector valve assembly and a piezo stack and driving method for driving an actuator in a piezo stack.
• the invention relates to a detection method for detecting a gap size of a gap between a
• the invention relates to a driving method for driving an actuator unit in the piezo stack, which is used for actuating the Injektorventilbaueria.
• An actuator unit in a piezo stack used to actuate an injector valve assembly in an internal combustion engine typically includes a stacked device having a plurality of electrode layers and a plurality of material layers responsive to application of an electric field. Each layer of material is arranged between two of the electrode layers. When an electric field across the electrode layers to the
• Actuator is applied, the material layers react by expanding, so that the actuator unit extends along a total Aktorillonsachse. From this ⁇ steering can be transferred to other components then, for example, a Injektorventilbaueria of an internal combustion engine ⁇ , of a needle seat to annul an injector needle off and thereby inject fuel into combustion chambers of the internal combustion ⁇ machine.
• Injector valve assembly is made by direct or indirect Transmission of the longitudinal extent of the actuator to the Injektorventilbauenstein, wherein for transmitting the Lekssaus ⁇ expansion at any point between the piezo stack, which has the actuator unit, and the injector valve assembly is a positive connection.
• the object of the invention is therefore to propose a detection method for detecting this gap size.
• Another object is to provide a driving method for
• a driving method for driving an actuator unit in a piezo stack is the subject of the independent claim.
• Injector valve assembly includes the following steps:
• Injektorventilbauner and the piezo stack are arranged spaced apart from each other via a gap of unknown gap size;
• the knowledge is used that a frictional connection between the piezo stack and the
• Injector valve assembly leads to a surge in the piezo stack.
• the force pulse corresponds to a force gradient, which generates a charge in the, so that, for example, a voltage can be tapped from the outside.
• the adhesion and thus the forces ⁇ gradient occur in the moment in which the gap between the piezo stack and Injektorventilbaueria is overcome. Since the voltage with which the actuator unit is subjected to expansion is known, the gap size of the gap can be deduced over a measured period of time until the sensor unit detects the frictional connection with the injector valve assembly.
• a previously determined characteristic field is advantageously stored which, for predefined voltage pulses, sets a gap size of the gap as a function of a time duration of the voltage pulse application.
• the modular structure of the piezo stack is advantageous from a
• Gap size to be determined Therefore, it is not necessary to provide further sensors, via which the gap size is to be determined, since already the existing sensor unit is used.
• the sensor unit detects a force increase in the second time point in which the piezoelectric stack reaches a frictional connection to the Inj ektorventilbaury.
• the gap size of the gap between the piezo stack and the Injektorventilbaueria is detected at each cycle of actuation betae ⁇ Injektorventilbaueria.
• actuation betae ⁇ Injektorventilbaueria it is possible to record further data on aging phenomena of the elements, for example a depolarization of the actuator unit or wear or abrasion phenomena of the elements, which are reflected in the life span of the gap.
• a positive voltage gradient is detected in the voltage signal of the Sen ⁇ sorvenez in the second time point. Accordingly, if the signal of the sensor unit representing the voltage gradient is positive, it can be immediately recognized that the second time is present.
• a second voltage gradient is detected in the voltage signal of the sensor unit. This can advantageously be detected exactly the time in which opens an injector for injecting fuel.
• a negative voltage gradient is detected in the voltage signal of the sensor unit.
• the signs can be detected accordingly, whether a force gradient in the piezo stack was caused by the fact that a positive connection between the piezo stack and Injektorventilbaueria has taken place, or in that the Injektornadel has lifted from the needle seat.
• a third voltage gradient is detected in the voltage signal of the sensor ⁇ unit in a fourth time in which the injector needle is in frictional engagement with the needle seat, wherein between the fourth time and the second time is the third time.
• a negative voltage gradient is advantageously detected.
• Injector needle opens, and also when the injector needle closes again.
• the injected fuel can be metered exactly to the respective combustion chamber. From the measured data it is also possible to provide a control which can compensate for aging phenomena, so that an exact injection of the fuel into the respective combustion chamber remains possible.
• a driving method for driving an actuator unit in a piezo stack for actuating an injector valve assembly in an internal combustion engine the actuator unit with a predetermined opening voltage pulse for lifting a
• Injector needle assembly of the injector valve assembly is loaded by a needle seat. Before the actuation of the actuator with the Opening voltage pulse, the following steps are Runaway ⁇ leads:
• the actuator unit can therefore be operated based on the high-precision measurement in the detection method with said pre-voltage pulse, so that at the particular time at which the injection is to start, a reproducible gap-free state between the piezo stack and injector valve assembly he ⁇ is enough.
• the injection control can thus be completely independent of an absolute length of the piezo stack, of
• a signal can be output as a wear indicator to the outside.
• the pre-voltage pulse is determined from the gap size determined by the detection method, wherein the pre-voltage pulse is newly determined in particular during each actuation cycle of the injector valve assembly.
• the gap size which changes over the service life can also be continuously compensated over the life of the arrangement.
• the detection method is performed in a first actuation cycle of the injector valve assembly, wherein the actuation of the actuator unit with the
• Injector valve assembly is performed. Therefore, is recognized in the acquisition proceedings before ⁇ geous how big the gap size is currently so that the necessary pre-voltage pulse can be determined. Only in the next cycle of operation, this pre-voltage pulse is used to compensate for the gap.
• the pre-voltage pulse is given to the actuator unit so early that a voltage pulse for opening the injector needle can be output as intended to the actuator unit without any time delay.
• the pre-voltage pulse can also be given immediately after the detection process has been carried out, even if the actual subsequent injection should take place much later in time.
• a total injector includes an actuator, a valve assembly having a valve seat and a valve piston, and a nozzle having a nozzle seat and a needle.
• An injector unit for injecting fuel into a combustion chamber of an internal combustion engine has a
• the injector unit has a piezo stack with an actuator unit and a sensor unit, which are coupled to one another in a force-locking manner.
• the sensor unit is designed for detecting force gradients acting on the actuator unit, and the actuator unit is for actuating the
• a gap is formed with a un ⁇ known gap size.
• a control unit is provided, which is designed to detect a voltage signal of the sensor unit and to act on the actuator unit with a voltage pulse. The control unit is thereby forms ⁇ out for carrying out the detection method described above, or for executing the driving method described above.
• the control unit has, for example, the two named maps, as well as means for detecting voltage gradients of the voltage signal of the sensor unit. Further advantageously, the control unit on elements with which the gap size of the gap and the required size of the pre-voltage pulse to close the gap can be ⁇ it averages out ver ⁇ different parameters.
• control unit advantageously has an output device in order to output voltage pulses to the actuator unit so that they can vary in their length along the actuator unit longitudinal axis.
• Fig. 2 is a schematic representation of a second embodiment of an injector with a
• Piezo stack and an injector valve assembly the injector according to the operating principle of the servo operation works
• Fig. 3 is a schematic longitudinal sectional view through the
• Piezo stack of Figure 1 and Figure 2 in greater detail. 4 is a flowchart illustrating a detection method for
• FIGS. 1 and 2 each show schematic representations of an injector unit 10 used for injecting fuel into a combustion chamber of an internal combustion engine.
• the injector unit 10 has an injector valve assembly 12 and a piezo stack 14 with which the injector valve assembly 12 can be actuated.
• an injector needle 16 is arranged, which cooperates with a needle seat 18 so that an injector valve 20 is formed. If the injector needle 16 lifts off from the needle seat 18, this becomes
• Injector 20 is opened, and it can fuel in the respective combustion chamber, which is connected to the injector 10, injected. However, if the injector needle 16 again comes into frictional connection with the needle seat 18, this is
• Injector 20 is closed, and the injection of fuel is finished.
• the piezo stack 14 has an actuator unit 22 and a sensor unit 24. These are arranged one above the other in the piezo stack 14 along an actuator unit longitudinal axis 26, wherein the
• Sensor unit 24 may be disposed above the actuator unit 22 (see Fig. 3) or under the actuator unit 22.
• the piezo stack 14 is connected to a control unit 28, which on the one hand can detect voltage signals from the sensor unit 24, but on the other hand can also output voltage pulses to the actuator unit 22 so that they can travel along the
• Aktorappellteilsachse 26 expands. Such an expansion along the Aktorappellteilsache 25 causes the piezo stack 14, for example via a pin 30 attached thereto, to the Injektorventilbaueria 12 moves. In this case, a gap 32 is overcome, which in the installed state of Injektorventilbaueria 12 and des Piezo stack 14 is always present, and also changed over the life of the individual elements in its gap size 34. Once the gap 32 has been overcome, and the actuator unit 22 continues to deflect along the actuator unit longitudinal axis 26, it is supplied via an operating unit 36 by the actuator unit 36
• Piezo stack 14 acting on the operating unit 36 force the Injektornadel 16 lifted from the needle seat 18.
• Piezo stack 14 is terminated, and the Injektornadel 16 can return to the needle seat 18 again.
• FIG. 1 a directly operated functional system is shown, in which the operating unit 36 lifts the injector needle 16 out of the needle seat 18 during a force application from the piezo stack 14 via lever 38.
• Fig. 2 shows an alternative embodiment in which the injector 10 operates via a servo operation, wherein the operating unit 36 has a liquid-filled control chamber 40 which exerts a closing force by the present in the control chamber 40 fluid pressure on the Injektornadel 16, and so in the Needle seat 18 stops.
• FIG. 3 shows a schematic longitudinal sectional illustration of the piezo stack 14 from FIG. 1 and FIG. 2 in greater detail.
• the piezo stack 14 has the actuator unit 22 and the sensor ⁇ unit 24, along the Aktoriserlteilsachse 26 in the 3 are arranged one above the other in such a way that the sensor unit 24 is arranged on the side of the actuator unit 22, the
• Injector valve assembly 12 faces away. However, it is also possible a reverse arrangement of actuator unit 22 and sensor unit 24.
• the actuator unit 22 comprises a plurality of electrode layers and a plurality of material layers which react with application of an electric field and which are arranged along the
• Aktorillonsachse 26 are arranged alternately stacked.
• the electrode layers and the material ⁇ layers are not shown in Fig. 3 for reasons of clarity.
• the electrical contacting of the electrode layers takes place via external electrodes 44, which are electrically connected to the electrode layers via electrical conductors 46.
• a contacting of the outer electrode 44 can also be done differently.
• the outer electrodes 44 are connected to the control unit 28, which can deliver voltage pulses to the actuator unit 22 via the outer electrodes 44, so that it expands along the Aktorappellticiansachse 26.
• the actuator unit 22 is non-positively connected to the sensor unit 24.
• the sensor unit 24 also advantageously has a sensor body 48 which is formed, for example, from the same material which also forms the material layers of the actuator unit 22. Electric ⁇ the layers 50 are arranged on the sensor body 48, in particular on two opposite side surfaces 52 along the
• Aktorillonsachse 26 are arranged.
• the electrode layers 50 are connected to a voltage measuring device 54, which forwards a voltage signal of the sensor unit 24 to the control unit 28.
• a flow chart for detecting this gap size 34 is shown in FIG. 4.
• a first point in time ti is detected, to which the actuation of the actuator unit 22 takes place with a voltage pulse, starting from the control unit 24.
• a voltage gradient dU occurs at a second time t 2 in a voltage signal, which is reported by the sensor unit 24 to the control unit 28.
• t 2 can then be detected the time duration At that has elapsed until the occurrence of the voltage gradient dU.
• Ki which sets the gap size 34 as a function of the time duration ⁇ t
• the gap size 34 present at the present time can then be determined.
• the voltage signal of the sensor unit 24 is further detected by the control unit 28, so that a third time t3 can be determined, to which another one
• Voltage gradient dU occurs, namely, when the Injektornadel 16 lifts from the needle seat 18.
• the sign of the voltage gradient is used, which is positive at time t 2 and negative at time t 3 .
• a further voltage gradient dU detected in a fourth time t4 which has a positive sign, which is due to a closing of the Injektornadel 16.
• FIG. 5 shows a flow chart which schematically shows a control method with which the actuator unit 22 can be controlled via the control unit 28.
• the gap size 34 of the gap 32 between the injector valve assembly 12 and the piezo stack 14 is determined.
• the size of the pre-voltage pulse is determined, which is necessary to close the gap 32.
• the actuator unit 22 is then subjected to this pre-voltage pulse. Subsequently, the actuator unit 22 is then subjected to an opening pulse in order to lift the injector needle 16 from the needle seat 18.
• the control unit 28 is configured to perform both the detection method illustrated in FIG. 4 and the drive method illustrated in FIG. 5.
• the control unit 28 as shown schematically in FIG. 6, displays the maps Ki and K 2 .
• detecting means 56 for detecting a voltage gradient dU in the voltage signal from the sensor unit 24 is provided.
• the control unit 28 comprises a time measuring device 58 and an output device 60, which comprises an opening pulse output device 62, from which an opening pulse is output to the actuator unit 22 for opening the injector needle 16.
• the opening pulse output device 62 gives a signal to the time measuring device 58 when it sends an opening pulse to the timer Actuator 22 has issued.
• the detection device 56 sends a signal to the time measuring device 58 when a voltage gradient dU has been determined via the sensor unit 24. From this, the time measuring device 58 can determine the period of time ⁇ t.
• a determination unit 64 is further provided, which can determine the gap size 34. For this purpose, it is supplied from the time measuring device 58, the detected time period At and the map Ki and the size of the opening pulse. From this data it is possible to determine the gap size 34, since the characteristic field Ki sets the gap size 34 as a function of the duration ⁇ t and the size of the opening pulse. Further, in the control unit 28, a determination unit 66 is provided to determine the size of the pre-voltage pulse, namely on the basis of the determined gap size 34 and the second map K 2 , which sets the necessary pre-voltage pulse for closing the gap 32 in dependence the determined gap size 34.
• the output device 60 includes in addition to the opening pulse output device 62 and a
• Pre-voltage pulse output device 68 the particular pre-voltage pulse from the determining unit 66 is supplied.
• the pre-voltage pulse output device 68 then outputs a signal to the actuator unit 22, which corresponds to the specific pre-voltage pulse, so that the actuator unit 22 can extend along the Aktoriserlticiansachse 26 such that the gap 32 disappears.

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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)

Priority Applications (4)

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Citations (5)

Family Cites Families (7)

• 2015
  • 2015-09-09 DE DE102015217193.0A patent/DE102015217193A1/de active Pending
• 2016
  • 2016-07-06 JP JP2018512562A patent/JP6667619B2/ja active Active
  • 2016-07-06 CN CN201680052548.8A patent/CN107923334B/zh active Active
  • 2016-07-06 EP EP16741260.0A patent/EP3347584B8/de active Active
  • 2016-07-06 KR KR1020187006809A patent/KR102027076B1/ko active IP Right Grant
  • 2016-07-06 WO PCT/EP2016/066021 patent/WO2017041923A1/de unknown

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