Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K15/00—Testing or calibrating of thermometers
  • G01K15/005—Calibration
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P19/00—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition
  • F02P19/02—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs
  • F02P19/025—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs with means for determining glow plug temperature or glow plug resistance
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P19/00—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition
  • F02P19/02—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs
  • F02P19/021—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs characterised by power delivery controls
  • F02P19/023—Individual control of the glow plugs

Definitions

• the invention relates to a method for determining the temperature of a glow plug when operating in an internal combustion engine, wherein a temperature-resistance reference correlation is determined, and an apparatus for performing the method.
• Glow plugs which are used in an internal combustion engine, have production technology for a nominal voltage a predetermined tolerance to be set to the glow plug temperature.
• a nominal voltage a predetermined tolerance to be set to the glow plug temperature.
• a temperature of 1200 ° C indicated as the annealing temperature, which allows a tolerance of +/- 50 K.
• the maximum temperature of the glow plug must not exceed 1,250 ° C.
• control devices which control the glow plugs in the internal combustion engine, applied, it must be noted that there may be deviations from the desired temperature of, for example, 1200 ° C. Since the controller can not react to changing tolerances during operation of the glow plugs in the internal combustion engine, the maximum Glühkerzentemperatur of 1200 ° C must be fixed in the control unit.
• a method and a device for regulating the temperature of glow plugs in an internal combustion engine are known, in which in a reference mode of the internal combustion engine, a mathematical relationship between measured temperatures and measured Resistances of at least one glow plug is formed, wherein the resistors result from an actual applied voltage and an actual current flow at this glow plug and this mathematical relationship dynamically adjusted over the life of the candle and used in the entire operation of the internal combustion engine.
• a mathematical relationship between measured temperatures and measured Resistances of at least one glow plug is formed, wherein the resistors result from an actual applied voltage and an actual current flow at this glow plug and this mathematical relationship dynamically adjusted over the life of the candle and used in the entire operation of the internal combustion engine.
• the method must take into account the changing operating conditions of the internal combustion engine. This complicates the application of the control unit for the built-in glow plug, since large tolerances must be taken into account when using the glow plug in the internal combustion engine.
• the invention is thus based on the object of specifying a method for determining a temperature of a glow plug when operating in an internal combustion engine, in which the actual tolerances of the glow plug are taken into account in the application of control units that control the glow plug during operation of the internal combustion engine. According to the invention the object is achieved in that after installation of the
• a calibration step is performed, in which by means of the, before the installation of the glow plug in the internal combustion engine temperature-resistance Referenzkorrelation a glow plug candle specific temperature-resistance correlation is determined, from rather the temperature of the glow plug during the Operation of the glow plug in the internal combustion engine is determined.
• This has the advantage that a higher maximum temperature of the glow plug in the control unit can be applied. By the higher, to be applied in the control unit candle temperature a better starting behavior and / or a quieter idling of the internal combustion engine is achieved. In addition, a reduction of the emission of the internal combustion engine is possible.
• a first resistance of the glow plug is determined during the calibration step when applying a first voltage to the glow plug, which from the Tempe- Ratur- resistance reference correlation is associated with a first temperature, wherein from this first temperature-resistance value pair, the glow plug specific temperature-resistance correlation is formed.
• the actual temperature of the glow plug is determined without direct temperature measurement, which reduces the test setup on the glow plugs.
• a second resistor is measured, to which a second temperature-resistance reference correlation assigns a second temperature, the first pair of values of the first measured resistance and the associated first temperature and of the first pair determined second value pair of the second measured Wderstandes and the associated second temperature the glow plug specific temperature-resistance correlation is formed. Due to the presence of two temperature-resistance value pairs, the glow plug specific temperature-resistance correlation can be easily determined in the form of a straight line that allows a reliable determination of the actual operating temperature of the glow plug, resulting in the further processing within the control unit reliable control or Regulation of the glow plug results.
• the temperature-resistance reference correlation is determined as an average value via a glow plug resistor from a plurality of glow plugs of a glow plug type with different production tolerances after their production.
• the known average values ensure particularly high reliability in the determination of the tolerance band of the glow plug candle-specific temperature-resistance correlation.
• Reference measurements during operation of the glow plugs in the internal combustion engine can be dispensed with, whereby an adverse effect on the temperature-resistance reference correlation is prevented by the current operating state of the internal combustion engine.
• the temperature-resistance reference correlation is designed as a reference characteristic, preferably a reference straight line, which is provided with a reference characteristic Tolerance band is provided, which has the same slope as the reference characteristic.
• the scattering of the temperature of the glow plug around this reference curve formed as a mean value curve as a function of the glow plug resistance is lower than when using the values of ⁇ 50 ° K. specified in the technical customer documents
• the reference characteristic curve is determined and stored once for each type of glow plug plug.
• the tolerance of the reference characteristic depends only on the Glüh.kerzentyp. On a consideration of the operating procedures of the internal combustion engine in the tolerance determination for each individual glow plug, which can be determined only in the use of the glow plug in the internal combustion engine, can thus be dispensed with. This not only simplifies the method of calibrating the glow plug, but it also improves the accuracy in determining the actual operating temperature of the glow plug.
• the tolerance width at the maximum temperature, which may have the glow plug, is thus limited and a higher maximum temperature of the glow plug can in the
• Control device to be applied.
• the temperature resistance reference correlation which has been determined only once, is used for all glow plugs of the same production lot. The determination of individual references for each glow plug is eliminated.
• the first calibration step of the glow plugs is carried out in a band end production of a motor vehicle. This ensures that the glow plugs installed in the internal combustion engine are already calibrated when the vehicle is put into operation.
• the calibration step for determining the glow plug-specific temperature-resistance correlation is carried out in a follow-up phase of a control device controlling and / or regulating the internal combustion engine. Because there are still defined and reproducible engine operating states in the follow-on phase of the control unit, a high level of Accurate calibration can be done because of the given operating conditions of the internal combustion engine can be used.
• the calibration step for determining the glow plug-specific temperature-resistance correlation is repeated several times. Due to the repeated calibration measurement during the life of the glow plug in the internal combustion engine, the aging phenomena on the glow plug in the glow plug specific temperature-resistance correlation are taken into account and thus increases the accuracy in determining the actual annealing temperature of the glow plug.
• a frequency of repetition of the calibration step for determining the glow plug specific temperature-resistance correlation depending on a number of occurred annealing and / or
• Glow intensities and / or the glow duration of the glow plug are improved by a multiple adjustment of the glow plug.
• the measurement of the first or second resistor after formation of a stationary temperature profile within the glow plug after the application of the first and second voltage. This ensures that the glow plug is evenly annealed before the measurement and no transient temperature distribution distorts the measuring process.
• a development of the invention relates to a device for determining the temperature of a glow plug when operating in an internal combustion engine, comprising a processing unit which is connected to a memory unit. is, wherein in the memory unit, a temperature-resistance reference correlation is stored.
• the processing unit performs after using the glow plug in the internal combustion engine from a calibration step, in which by means of the, before the use of the glow plug in the internal combustion engine temperature determined Resistance reference correlation determines a glow plug specific temperature-resistance correlation and determined from the stored in the memory unit, glow plug specific temperature-resistance correlation, the processing unit during operation of the glow plug in the internal combustion engine determines the temperature of the glow plug.
• the processing unit applying a first voltage to the glow plug is advantageously connected to a current sensor which sends a first current signal to the processing unit, which determines a first resistance value from this first current signal and a first heat resistance value from the stored temperature-resistance reference correlation first temperature value assigns and then applies a second voltage to the glow plug, wherein the current sensor of the processing unit supplies a second current signal, from which the processing unit has a second
• the processing unit of the first temperature-resistance pair of values and the second temperature-resistance pair of values determines the glow plug specific temperature-resistance correlation.
• the determination of the glow plug-specific temperature-resistance correlation is performed with an inherent hardware, thereby enabling a low-cost method. Due to the presence of two temperature-resistance value pairs, the glow plug-specific temperature-resistance correlation can easily be determined in the form of a straight line, which is used in further processing. processing within the control unit ensures reliable control or regulation of the glow plug. In this case, a reliable determination of the actual operating temperature of the glow plug.
• Fig. 1 Schematic representation of an annealing system in a motor vehicle
• Fig. 3 Temperature-resistance behavior of a production batch of
• Fig. 4 annealing pencil specific temperature-Wderstands correlation of individual glow plugs.
• a start-up aid for ignition of the fuel-air mixture introduced in the internal combustion engine at ambient temperatures of ⁇ 40 ° C.
• glow systems which consists of glow plugs, a glow time control unit and an annealing software, which is stored in an engine control unit or the Glühzeit Kunststoffgeber consists.
• annealing systems are also used to improve the emission of the vehicle. Further fields of application of the glow system are the burner exhaust system, the auxiliary heating, the preheating of fuel or the preheating of the cooling water.
• each glow plug 21 to 24 protrudes in each case a cylinder, not shown, a combustion chamber of the internal combustion engine.
• the glow plugs 21 to 24 are identically constructed and represent common low-voltage glow plugs.
• the glow plugs 21 to 24 are shown for the sake of simplicity as a substitute resistor, which lead to the mass 3 of the internal combustion engine.
• the glow plugs 21 to 24 are connected to a glow time control unit 4, which has a power semiconductor 51 to 54 for each glow plug 21 to 24.
• the glow time control device 4 comprises a microcontroller 4a for processing incoming and outgoing signals.
• a vehicle electrical system voltage 6 is connected to the glow time control unit 4, which supplies the glow plugs 21 to 24 via the power semiconductors 51 to 54 with the required nominal voltage.
• the Glühzeit tenu réelle 4 leads to an engine control unit 7, which in turn is connected to the internal combustion engine, not shown.
• the engine control unit 7 and the glow time control unit 4 have an interface. This interface can consist of both a single-wire and a two-wire connection 10, 11. Data is exchanged between the engine control unit 7 and the glow time control unit 4 via this interface, in which case both the activation of the glow time control unit 4 and the diagnosis communication take place.
• the glow time control device 4 outputs via the power semiconductors 51 to 54 to the glow plugs 21 to 24 a pulse width modulated output signal (PWM).
• PWM pulse width modulated output signal
• the glow time control device 4 comprises a memory unit 12.
• the power semiconductor connected to the glow plug 21 to 24 serves to measure the current flowing through each glow plug 21 to 24, which is fed to the microcontroller 4a 51 to 54, which is advantageously designed as a smart field effect transistor which generates a PWM signal and at the same time measures the current.
• the microcontroller 4a determines from this the corresponding resistance of the glow plug 21 to 24.
• a MOSFET and a shunt can be used.
• the maximum annealing temperature which is applied during operation in the engine to each of a glow plug 21 to 24, to be determined. It will be in a first
• FIG. 2 shows a cloud of measured values for a large number of post-production ceramic glow plugs which were subjected to a nominal voltage of 7 volts.
• the individual points characterize the individual glow plugs, wherein the determined maximum annealing temperature of the glow plugs includes a tolerance of 1200 ° C +/- 50 K.
• This tolerance band is represented by the lines A1 and A2, which comprises the cloud of the measured values of the individual glow plugs.
• an average curve B is determined via the glow plug resistance R, wherein the temperatures are averaged for the glow plugs with the same Wderstand.
• Tolerance bands which are also delimited by straight lines, which have the same slope as the straight-line mean value curve B, are placed around this mean value curve B.
• the tolerance bands therefore run parallel to the mean value curve B with a constant width and are represented by the dashed lines B1 and B2 marked.
• the resistance R is only ⁇ 30 K in the case of the tolerance bands B1 and B2.
• a second nominal voltage of 4 V is applied to the ceramic glow plugs, wherein a second mean value curve F, which likewise represents a straight line and is enclosed by the tolerance band F1, F2, is determined from the cloud of the measured values. Even with this second mean value curve F, the tolerance of the maximum annealing temperature of the glow plug is +/- 30 K.
• the glow plugs 21 to 24 which were taken from the measured after production production batch, installed in the internal combustion engine.
• the same interface of the glow time control unit is used as when activating the calibration by a workshop tester.
• the positioning of this calibration measurement during the overrun is important because there are defined and reproducible engine operating conditions.
• the frequency of the calibration measurement during the use of the motor vehicle depends on the number of driven kilometers of the motor vehicle, the
• the glow time control device 4 determines the resistance values corresponding to the glow plugs 21 and 22.
• a resistance R 21 7 is measured for the first glow plug 21, which is shown in FIGS. 2 and 3 by the point 21.
• This resistance R 21 7 is extended in Fig. 2 to the mean value curve B and starting from the intersection of the resistance value R 21 7 with this mean curve B, the associated temperature T 21 7 of the glow plug 21 is determined, which by the
• Line C is marked in Fig. 2.
• This first value pair R21 7 ; T21 7 represents a first starting point for the preparation of the glow plug-specific temperature-resistance correlation II of the glow plug 21.
• the second glow plug 22 is characterized in FIGS. 2 and 3 by the point 22.
• a resistance R 22 7 is measured after applying the nominal voltage of 7 volts.
• This resistance value R 22 7 is also shifted to the mean value curve B and starting from the intersection of the mean value curve B with the resistance value R 22 7 , the maximum annealing temperature T 22 7 of the glow plug 22 is determined, which is indicated by the line D.
• This value pair R 22 7 , T 22 7 is used as a starting point for the second glow-specific temperature-resistance correlation III of the second glow plug 22.
• Fig. 3 the temperature-resistance values of the production batch are measured, which were operated before installation in an internal combustion engine at a nominal voltage of 4 volts. Due to this lower nominal voltage of 4 V, the resistance and temperature levels are lower than shown in Fig. 2. Wrd now again the glow plug 21, which is characterized by the point 21, picked out, so after the control with 4
• a resistance R 21 4 determined. This resistor R 21 4 is shifted to the mean value curve F and the belonging to the intersection temperature T 21 4 of the glow plug 21 is determined, which is indicated by the line C. From the value pair (R21 4 , T21 4 ) determined at 4 V nominal voltage and the value for the nominal voltage 7V telten value pair (R21 7; T21 7) determines the first glühmannker- zenspezifische temperature resistance in the form of correlation of the straight line II for the glow plug 21, as is illustrated in Fig. 4. In the glow plug 22, which is shown in point 22, a resistance R 22 4 is measured at a control of the glow plug 22 with a nominal voltage of 4 volts.
• This Westerstand R 22 4 results using the second mean value curve F a temperature T 22 4 of the glow plug 22 (line D).
• the value pairs (R22 4 , T22 4 ) and (R22 7, T22 7 ) enable the construction of the second glow plug-specific temperature-resistance correlation for the second glow plug 22, as shown in the form of the straight line III in FIG.
• FIG. 4 shows the glow plug-specific temperature-heat distortion correlation I for a so-called "mean-value candle", which corresponds to a glow plug, of which FIG
• the resistance R of a glow plug 21, 22 measured at 7 volts and at 4 volts and each of these resistance values assigned a temperature value which was determined by means of the mean curve B or F, value pairs are formed from which for each respective glow plug 21, 22 a glow pencil specific temperature resistance line is determined.
• the expected fluctuations around this straight line are only +/- 30 K.
• the maximum temperature of the glow plug 21, 22 can be applied with 1,220 ° C in the Glühunition 4, and thus higher than in the prior art, as with the maximum Tolerance of +/- 30 K, the permissible maximum temperature of 1,250 ° C is not exceeded.
• glow plug-specific temperature-resistance correlations are stored in the memory 12 of the glow time control device 4.
• a voltage which must be applied to the respective glow plug 21, 22 to achieve a voltage setpoint a control or regulation is subjected.
• the knowledge of the maximum annealing temperature of each glow plug 21, 22 is necessary. This maximum annealing temperature is determined on the basis of the, measured at the respective glow plug from the resistor, to the glow plug 21, 22 stored, stored glow pencil specific temperature-resistance - II or III correlation.
• the calibration step may be cyclically repeated to account for the aging of the glow plug 21, 22 in the internal combustion engine.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)

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• 2011
  • 2011-04-29 DE DE102011017814A patent/DE102011017814A1/de not_active Ceased
• 2012
  • 2012-04-18 CN CN201280021061.5A patent/CN103502630A/zh active Pending
  • 2012-04-18 WO PCT/EP2012/057041 patent/WO2012146513A1/de not_active Ceased
  • 2012-04-18 US US14/114,489 patent/US9612166B2/en active Active
  • 2012-04-18 EP EP12715979.6A patent/EP2702264B1/de active Active
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