JP4483596B2 - Fuel injection control device, fuel injection valve, and adjustment method of fuel injection control - Google Patents

Description

  The present invention relates to a fuel injection control device, a fuel injection valve, and a method for adjusting fuel injection control that compensate for variations in injection characteristics caused by individual differences in fuel injection valves.

  As this type of fuel injection control device, for example, as can be seen in Patent Document 1 below, by correcting the energization time of an electromagnetically driven fuel injection valve of a diesel engine, the amount of injected fuel caused by the individual difference is corrected. Some have been proposed to compensate for variations. According to this fuel injection control device, it is possible to suppress variations in the amount of fuel injected regardless of individual differences in fuel injection valves.

  Incidentally, engine output performance and exhaust characteristics are not uniquely determined by the amount of fuel actually injected. That is, if the deviation amount or injection rate between the injection start command timing and the actual timing is different, the spray shape of the fuel injected into the combustion chamber of the engine is different even if the injected fuel amount is the same. As a result, the output performance and exhaust characteristics of the engine differ.

  For this reason, even if appropriate fuel injection control is performed to maintain good output performance and exhaust characteristics based on the operating state of the engine, etc., the actual fuel injection mode is different depending on the individual fuel injection valve. It may not be appropriate to maintain good output performance and exhaust characteristics.

  Further, in order to maintain the engine output performance and exhaust characteristics well, the period during which fuel injection is normally allowed is also limited. Therefore, since the correction amount of the valve opening period by the apparatus described in Patent Document 1 is naturally limited, there is a possibility that sufficient correction cannot be performed.

For this reason, the conventional fuel injection control apparatus is not sufficient to cope with the recent situation in which the restriction on the exhaust characteristics and the demand for the output performance of the engine are becoming stricter.
JP 2000-220508 A

  The present invention has been made to solve the above-mentioned problems, and its purpose is to more suitably compensate for variations in injection characteristics due to individual differences in fuel injection valves, and thus improve output performance and exhaust characteristics. An object of the present invention is to provide a fuel injection control device, a fuel injection valve, and a fuel injection control adjustment method that can be performed.

  In the following, means for achieving the above object and its effects are described.

According to a second aspect of the present invention, there is provided a fuel injection control device that stores fuel pressurized and supplied by a fuel pump in a high pressure state in a pressure accumulating chamber, and injects fuel stored in the pressure accumulating chamber via a fuel injection valve. Storage means for storing a correction amount of the fuel pressure in the pressure accumulating chamber set based on an actual measurement value of the maximum value of the fuel injection rate in a state in which the pressure of the fuel supplied to the fuel injection valve is set to a plurality of different values. Set based on measured values of deviations between the command timing of the start of injection and the actual timing for the one fuel injection valve in a state where the pressure of the fuel supplied to the one fuel injection valve is set to a plurality of different values. A storage means for storing the correction amount of the command timing for starting the injection of the one fuel injection valve, and a plurality of values for the pressure Based on the fuel pressure correction amount corresponding to the current fuel pressure of the pressure accumulator chamber, based on the means for controlling the fuel pressure in the pressure accumulator chamber before fuel injection by the fuel injection valve, and the command timing correction amount And means for variably setting a command timing for starting injection with respect to the one fuel injection valve .

  Variations in the fuel injection rate due to individual differences tend to appear significantly in variations in the maximum value of the injection rate of the fuel injection valve. For this reason, the variation in the fuel injection rate in the fuel injection period can be appropriately grasped by the maximum value of the injection rate.

  For this reason, in the said structure, the dispersion | variation in a fuel injection rate can be compensated simply and suitably.

By the way, the fuel injection rate varies depending not only on the individual difference of the fuel injection valves but also on the fuel pressure in the pressure accumulating chamber. And the dispersion | variation in the fuel injection rate by the individual difference of a fuel injection valve changes with the fuel pressure in a pressure accumulation chamber.

  In this regard, in the above configuration, by using the measured value of the fuel injection rate when the fuel pressure in the pressure accumulating chamber is set variously, the variation in the fuel injection rate due to individual differences can be appropriately considered while taking into account the influence of the fuel pressure in the pressure accumulating chamber. Can be compensated.

Further, according to the above configuration, the correction amount of the fuel pressure is stored, so that the calculation load of the setting unit can be reduced.

On the other hand, when the actual timing changes with respect to the injection start command timing, the spray shape of the actually injected fuel changes, and as a result, the output performance and the exhaust characteristics change.

  In this regard, in the above configuration, since the command timing for starting the injection is variably set based on the actually measured value of the deviation amount, individual differences can be compensated more favorably, and as a result, output performance and exhaust characteristics can be improved. be able to.

By the way, the amount of deviation varies depending not only on the individual difference of the fuel injection valves but also on the fuel pressure in the pressure accumulating chamber. And the dispersion | variation in the said deviation | shift amount by the individual difference of a fuel injection valve changes with the fuel pressure in a pressure accumulation chamber.

  In this regard, in the above configuration, by using the measured value of the deviation when the fuel pressure in the pressure accumulator chamber is set variously, the variation in the deviation due to the individual difference is appropriately added while taking into account the influence of the fuel pressure in the accumulator chamber. Can be compensated.

Further, according to the above configuration, since the correction amount of the command timing is stored, the calculation load of the setting unit can be reduced.

The invention according to claim 1 is a fuel injection control device in which fuel pressurized and supplied by a fuel pump is stored in a pressure accumulating chamber in a high pressure state, and fuel stored in the pressure accumulating chamber is injected via a fuel injection valve. In the state where the pressure of the fuel supplied to the fuel injection valve is set to a plurality of values different from each other, the fuel injection valve is set based on an actual measurement value of a difference between the injection start command timing and the actual timing for the one fuel injection valve. A storage means for storing a correction amount and a correction amount of an injection start command timing of the one fuel injection valve, and an injection start command timing for the first fuel injection valve based on the correction amount of the command timing And variably setting means .

  When the actual timing changes with respect to the injection start command timing, the spray shape of the fuel that is actually injected changes, and as a result, the output performance and the exhaust characteristics change.

  In this regard, in the above configuration, since the injection start command timing is variably set based on the actual measurement value of the deviation amount, it is possible to favorably compensate for the injection characteristics due to individual differences, and consequently, the output performance and the exhaust gas. Characteristics can be improved.

By the way, the amount of deviation varies depending not only on the individual difference of the fuel injection valves but also on the fuel pressure in the pressure accumulating chamber. And the dispersion | variation in the said deviation | shift amount by the individual difference of a fuel injection valve changes with the fuel pressure in a pressure accumulation chamber.

  In this regard, in the above configuration, by using the measured value of the deviation when the fuel pressure in the pressure accumulator chamber is set variously, the variation in the deviation due to the individual difference is appropriately added while taking into account the influence of the fuel pressure in the accumulator chamber. Can be compensated.

Further, according to the above configuration, since the correction amount of the command timing is stored, the calculation load of the setting unit can be reduced.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the storage unit is provided in the fuel injection valve.

  In the above configuration, the fuel injection valve is provided with means for storing the information, so that the fuel injection valve can be easily associated with the setting means. For this reason, since it is not necessary to manufacture them while associating them in advance, the complexity at the time of manufacturing can be eliminated.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the fuel injection control device is mounted on a diesel engine.

  In a diesel engine, variations in spray shape and the like due to individual differences in fuel injection valves tend to greatly affect output performance and exhaust characteristics.

In this regard, the invention described in claim 5 has a configuration capable of suitably exhibiting the function and effect of the invention described in claims 1-4 .

  Hereinafter, an embodiment in which a fuel injection control device, a fuel injection valve, and a fuel injection control adjustment method according to the present invention are applied to a diesel engine fuel injection control device, a fuel injection valve, and a fuel injection control adjustment method will be described. This will be described with reference to the drawings.

  FIG. 1 shows an overall configuration of a fuel injection system including a fuel injection control device according to the present embodiment. As shown in the figure, the fuel in the fuel tank 1 is pumped up by the fuel pump 4 through the filter 2. The fuel pumped up by the fuel pump 4 is pressurized and supplied to the common rail 6. The common rail 6 accumulates high-pressure fuel (high-pressure fuel) supplied under pressure from the fuel pump 4 and supplies high-pressure fuel to the fuel injection valves 10 (here, only one cylinder fuel injection valve is illustrated). It is a piping that distributes and supplies.

  The fuel injection valve 10 injects and supplies high-pressure fuel supplied from the common rail 6 to the combustion chamber of the engine. Specifically, a cylindrical needle storage portion 12 is provided at the tip of the fuel injection valve 10. The needle storage section 12 stores a nozzle needle 14 that can be displaced in the axial direction. The nozzle needle 14 is seated on an annular needle seat portion 16 formed at the tip of the fuel injection valve 10, thereby blocking the needle storage portion 12 from the outside (engine combustion chamber), while the needle seat portion 16. The needle storage portion 12 is communicated with the outside by being separated from the needle. Further, high pressure fuel is supplied from the common rail 6 through the high pressure fuel passage 18 to the needle storage portion 12.

  The back side of the nozzle needle 14 (the side opposite to the side facing the needle seat portion 16) faces the back pressure chamber 20. High pressure fuel is supplied to the back pressure chamber 20 from the common rail 6 through the high pressure fuel passage 18. Further, a needle spring 22 is provided at an intermediate portion of the nozzle needle 14, and the nozzle needle 14 is pushed toward the tip end side of the fuel injection valve 10 by the needle spring 22.

  On the other hand, the low-pressure fuel passage 24 communicates with the fuel tank 1, and the low-pressure fuel passage 24 and the back pressure chamber 20 are communicated and blocked by the valve body 26. That is, the orifice 28 that connects the back pressure chamber 20 and the low pressure fuel passage 24 is closed by the valve body 26, whereby the back pressure chamber 20 and the low pressure fuel passage 24 are blocked, while the orifice 28 is opened. Thus, the back pressure chamber 20 and the low pressure fuel passage 24 are communicated with each other.

  The valve body 26 is pushed toward the distal end side of the fuel injection valve 10 by the valve spring 30. Further, the valve body 26 can be displaced to the rear side of the fuel injection valve 10 by being attracted by the electromagnetic force of the electromagnetic solenoid 32.

  The fuel injection valve 10 is provided with a plate 38 having a QR code (registered trademark) for storing information about individual differences. This will be described in detail later.

  In such a configuration, when the electromagnetic solenoid 32 is not energized and the attractive force by the electromagnetic solenoid 32 is not working, the valve body 26 closes the orifice 28 by the force of the valve spring 30. On the other hand, the nozzle needle 14 is pushed toward the distal end side of the fuel injection valve 10 by the needle spring 22 and is in a state of being seated on the needle seat portion 16 (the fuel injection valve 10 is closed).

  Here, when the electromagnetic solenoid 32 is energized, the valve body 26 is displaced to the rear side of the fuel injection valve 10 by the suction force of the electromagnetic solenoid 32 to open the orifice 28. As a result, the high pressure fuel in the back pressure chamber 20 moves to the low pressure fuel passage 24 via the orifice 28. For this reason, the pressure applied to the nozzle needle 14 by the high-pressure fuel in the back pressure chamber 20 is smaller than the pressure applied to the nozzle needle 14 by the high-pressure fuel in the needle housing portion 12. When this pressure difference becomes larger than the force with which the needle spring 22 pushes the nozzle needle 14 toward the tip of the fuel injection valve 10, the nozzle needle 14 is separated from the needle seat portion 16 (opening of the fuel injection valve 10). Valve state).

  As described above, the fuel injection valve 10 is a normally closed type injection valve that is closed when the energization control of the electromagnetic solenoid 32 is not performed.

  In addition, the fuel injection valve 10 has a balance of pressure applied to both ends by the fuel filled in the chambers (needle storage portion 12 and back pressure chamber 20) facing both ends in the displacement direction of the nozzle needle 14. It is also a pressure balance type injection valve operated by the displacement of the valve body 26. In this pressure balance type injection valve, the opening and closing of the fuel injection valve 10 are controlled by operating the balance of the pressure applied to both ends of the nozzle needle 14 by the high pressure fuel. Therefore, the amount of energy required for the valve body 26 and the electromagnetic solenoid 32, which are actuators used for opening and closing the valves, can be reduced.

  The low-pressure fuel passage 24 is connected not only to the fuel tank 1 but also to a pressure limiter 40 that limits the fuel pressure in the common rail 6 so as not to exceed a predetermined threshold value. When the pressure in the common rail 6 exceeds a predetermined threshold value, the fuel in the common rail 6 is returned to the fuel tank 1 via the pressure limiter 40, so that the pressure in the common rail 6 rises above the predetermined threshold value. Avoid that. Further, the common rail 6 is provided with a pressure reducing valve 42 for adjusting the fuel pressure in the common rail 6 by appropriately returning the fuel in the common rail 6 to the fuel tank 1. Further, the common rail 6 is provided with a pressure sensor 44 for detecting the internal fuel pressure.

  On the other hand, the electronic control unit (hereinafter referred to as ECU 50) includes a central processing unit and a memory, takes in the detection values of various sensors that detect the operating state and operating environment of the diesel engine, and based on these, Controls output characteristics. That is, for example, fuel injection control is performed to maintain good output performance and exhaust characteristics of the diesel engine according to the operating state of the diesel engine. This is done in the following manner.

  That is, the ECU 50 sets the target fuel pressure in the common rail 6 based on the operating state and operating environment of the diesel engine. Based on this target fuel pressure, the actual fuel pressure in the common rail 6 is controlled to the target fuel pressure by operating the fuel pump 4 and the pressure reducing valve 42. Further, the ECU 50 calculates the fuel injection amount and the injection start command timing based on the user's request, the operating state of the diesel engine, and the operating environment. The energization operation of the fuel injection valve 10 is performed based on the calculated fuel injection amount and the injection start command timing.

  However, even if the fuel injection amount and the command timing for starting the injection are set based on the operating state and operating environment of the diesel engine, the injection characteristics of the fuel injection valve 10 vary due to individual differences of the fuel injection valve 10, so the output performance or Exhaust characteristics may not be maintained well.

  Here, the variation in the injection characteristics due to the individual difference of the fuel injection valves 10 is shown in FIG. In both FIG. 2A and FIG. 2B, the horizontal axis is time, and the vertical axis is fuel injection rate. Here, the fuel injection rate is an amount defined as a fuel injection amount per unit time (an amount defined as a change amount of the fuel injection amount).

  As shown in FIG. 2A, due to the individual difference of the fuel injection valves 10, the degree of increase in the fuel injection rate accompanying the start of fuel injection, the maximum value of the fuel injection rate, and the like vary. Further, as shown in FIG. 2B, due to individual differences of the fuel injection valves 10, the injection start timing also varies.

  Therefore, in the present embodiment, the maximum value of the injection rate of the fuel injection valve 10 is measured, and based on this, the fuel pressure in the common rail 6 is corrected, and the actual timing deviation with respect to the injection start command timing is measured. Based on this, the energization start timing of the fuel injection valve 10 is corrected. This will be described in detail below.

  FIG. 3 shows a processing procedure for compensating for variations in injection characteristics caused by individual differences in the fuel injection valves 10.

  In this series of processes, first, in step S10, the injection characteristic of the fuel injection valve 10 is measured. Specifically, as shown in FIG. 4, the maximum value of the injection rate of the fuel injection valve 10 and the actual timing deviation with respect to the injection start command timing for the fuel injection valve 10 are measured. Incidentally, FIG. 4 (a) shows an energization operation mode for the fuel injection valve 10, and FIG. 4 (b) shows the injection characteristic measured at that time.

  In the energization waveform shown in FIG. 4A, the energization amount is reduced stepwise after the maximum energization amount is first obtained. The reason why the maximum energization amount is initially set is that the maximum energization amount is required to start the displacement of the valve body 26 shown in FIG. In the present embodiment, the energization amount is reduced to zero in three stages and becomes zero. The first stage energization reduction is performed after the displacement of the valve element 26 is started. This is performed in order to obtain an energization amount necessary to continue displacement. The energization amount in the second stage is reduced in order to obtain an energization amount required for holding the valve element 26 in a state where the valve element 26 is displaced by the maximum amount toward the electromagnetic solenoid 32 side.

  In the present embodiment, the above measurement is performed in the form shown in FIG. That is, the tip of the fuel injection valve 10 is placed in a container 60 having a strain gauge 61 on its inner periphery, and the pressure exerted on the strain gauge 61 by the injected fuel is converted into an electrical signal, so that the fuel injection rate, etc. measure.

  In the present embodiment, the maximum value of the fuel injection rate and the actual timing deviation with respect to the injection start command timing are measured in a state where the fuel pressure in the common rail 6 is set to a plurality of different values. This is because the variation in the injection characteristics is not uniquely determined by the individual difference of the fuel injection valves 10. That is, the variation in the injection characteristics also changes depending on the fuel pressure in the common rail 6, and the variation in the fuel characteristics also changes depending on the fuel pressure in the common rail 6. Therefore, in the present embodiment, by using the actual measurement values when the fuel pressure in the common rail 6 is set in various ways, variations in injection characteristics due to individual differences are compensated while appropriately taking into account the influence of the fuel pressure in the common rail 6.

  In the subsequent step S20, the correction amount of the fuel pressure in the common rail 6 and the correction amount of the injection start command timing are calculated based on the measurement result. Here, the maximum value of the reference injection rate is set, and the correction amount of the fuel pressure is set in such a manner that the correction amount becomes zero when the maximum value of the measured injection rate becomes the maximum value of the reference injection rate. Set. In addition to setting a reference deviation amount, the correction amount for the command timing is set in such a manner that the correction amount becomes zero when the measured deviation amount becomes the reference deviation amount.

  Incidentally, in the setting of such a correction amount, actually, after setting the correction amount of the fuel pressure, the deviation amount is measured at the corrected fuel pressure, and the correction amount of the command timing is set based on the measurement result. It is desirable to do so. That is, in the processes of steps S10 and S20, in practice, after the measurement of the maximum value of the injection rate and the setting of the fuel pressure correction amount, the deviation amount is measured and the command timing correction amount is set. It is desirable to make it.

  In the subsequent step S30, the calculated correction amount is stored in the QR code provided in the fuel injection valve 10. Here, the QR code is a kind of two-dimensional code having the overview shown in FIG. 6 and having information in the vertical direction and the horizontal direction.

  In subsequent step S40, when the fuel injection valve 10 is mounted on a diesel engine, the correction amount is read from the QR code and stored in the ECU 50. That is, as shown in FIG. 6, the QR code provided in the fuel injection valve 10 is read by the QR code scanner 70 and once taken into the personal computer 72. The personal computer 72 converts the captured QR code into data (correction data) that can be processed by the ECU 50 and outputs the data to the ECU 50.

  In subsequent step S50, the ECU 50 controls the fuel pressure in the common rail 6 based on the correction amount taken in in step S40. In step S60, the injection start command timing is corrected.

  Specifically, the process in step S50 is the process shown in FIG. FIG. 7 shows the details of the processing procedure of step S50. This process is actually repeatedly executed by the ECU 50 at a predetermined cycle.

  In this series of processing, first, in step S52, the detected value of the fuel pressure in the common rail 6 is captured. In the subsequent step S54, the correction amount of the fuel pressure in the common rail 6 is calculated based on the fuel pressure taken in in step S52 and the correction amount stored in step S40 of FIG. . This process is performed when it is time to inject fuel in any cylinder of the diesel engine. That is, at such a timing, a correction amount that compensates for variations in the maximum value of the injection rate of the corresponding fuel injection valve 10 is read out from the correction amounts stored in step S40 of FIG. 3 (calculation of correction amount). However, as described above, the correction amount that compensates for the individual difference of the corresponding fuel injection valve 10 is stored for each fuel pressure of various values, and thus is stored based on the fuel pressure taken in step S52. An appropriate correction amount is read out from the correction amount (calculation of the correction amount). At this time, when the various values do not match the captured fuel pressure, a correction amount is calculated by interpolation processing or the like, for example.

  When the correction amount is thus calculated, in step S56, the fuel pump 4 or the pressure reducing valve 42 is operated based on the correction amount. Specifically, when the correction amount is smaller than zero, in other words, when the maximum value of the injection rate of the fuel injection valve 10 is larger than the reference maximum value, the pressure reducing valve 42 is set to reduce the fuel pressure in the common rail 6. Manipulate. On the other hand, when the correction amount is larger than zero, in other words, when the maximum value of the injection rate of the fuel injection valve 10 is smaller than the reference maximum value, the fuel pump 4 is turned on to increase the fuel pressure in the common rail 6. Manipulate.

  Incidentally, the correction of the fuel pressure in the common rail 6 can be performed by either feedforward control or feedback control. That is, in the feedforward control, the operation of the pressure reducing valve 42 and the fuel pump 4 may be performed in the above manner before the fuel is injected from the corresponding fuel injection valve 10. In the feedback control, the target fuel pressure may be corrected based on the correction amount before fuel is injected from the corresponding fuel injection valve 10.

  Further, the process in step S60 is specifically the process shown in FIG. FIG. 8 shows the details of the processing procedure of step S60. This process is actually repeatedly executed by the ECU 50 at a predetermined cycle.

  In this series of processing, first, based on step S61, the user's request, the detected values of various sensors relating to the operating state and operating environment of the diesel engine are captured. In subsequent step S63, the fuel injection amount is calculated based on the detection values of the various sensors taken in in step S61. In step S65, the fuel injection start command timing is calculated based on the detection values of the various sensors captured in step S61.

  In step S67, a correction amount that compensates for the individual difference of the fuel injection valve that performs fuel injection is calculated based on the fuel pressure. That is, among the correction amounts stored in step S40 of FIG. 3, the correction amount that compensates for variations in the timing of the start of injection due to the individual difference of the corresponding fuel injection valve 10 is read (calculation of the correction amount). However, as described above, the correction amount for compensating for the variation in the injection characteristic of the corresponding fuel injection valve 10 is stored for each fuel pressure of various values, and therefore stored based on the fuel pressure taken in step S61. An appropriate correction amount is read out from the corrected correction amount (calculation of the correction amount). At this time, when the various values do not match the captured fuel pressure, a correction amount is calculated by interpolation processing or the like, for example.

  When the correction amount is thus calculated, in step S69, the command timing calculated in step S65 is corrected based on the correction amount. Then, based on the corrected command timing, the fuel injection valve 10 is energized.

  As described above, in this embodiment, the fuel pressure in the common rail 6 is corrected based on the actually measured value of the maximum value of the injection rate of the fuel injector 10 prior to the fuel injection in each fuel injector 10 of each cylinder. Further, the command timing was corrected based on the actual measurement value of the actual timing deviation with respect to the injection start command timing of the fuel injection valve 10. Thereby, as illustrated in FIG. 9, the injection characteristics of the fuel injection valves 10 can be made substantially equal regardless of the individual differences of the fuel injection valves 10. Incidentally, FIG. 9A shows the energization amount to the fuel injection valve 10 in each cylinder, and the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder are set in the order of performing the fuel injection.

  Here, although the injection rate of the fuel injection valve 10 and the injection start timing have a correlation with the fuel injection amount, it is only necessary to measure the fuel injection amount and correct the energization operation period of the fuel injection valve 10 based on this. Therefore, the variation in the injection characteristics cannot be corrected sufficiently. On the other hand, as in this embodiment, by actually measuring the maximum value of the injection rate and the amount of deviation, and performing various corrections based on this, it is possible to suitably suppress the variation in the injection characteristics. For this reason, by adapting the basic fuel injection control so that the output performance and exhaust characteristics are good at the maximum value of the standard injection rate and the standard deviation amount at which the correction amount becomes zero, Regardless of the difference, output performance and exhaust characteristics can be kept good.

  According to the embodiment described above in detail, the following effects can be obtained.

  (1) The fuel pressure in the common rail 6 was controlled based on the actually measured value of the maximum injection rate of the fuel injection valve 10. The maximum value of the injection rate tends to represent the variation in the fuel injection rate due to the individual difference, and the variation in the fuel injection rate in the fuel injection period can be appropriately grasped by the maximum value of the injection rate. . For this reason, in this embodiment, the dispersion | variation in a fuel injection rate can be compensated simply and suitably.

  (2) The actual measured value of the maximum value of the fuel injection rate actually measured in a state where the fuel pressure in the common rail 6 is set to a plurality of different values is stored in the ECU 50. Thereby, it is possible to compensate for variations in the fuel injection rate due to individual differences while appropriately taking into account the influence of the fuel pressure in the common rail 6.

  (3) The ECU 50 stores the correction amount of the fuel pressure in the common rail 6 based on the actual measurement value of the maximum value of the injection rate. Thereby, the calculation load which ECU50 performs can be reduced.

  (4) The fuel injection valve 10 is provided with a QR code that stores the correction amount of the fuel pressure in the common rail 6 based on the actual measurement value of the maximum value of the fuel injection rate. Thereby, the association between the fuel injection valve 10 and the ECU 50 is facilitated. For this reason, since it is not necessary to manufacture them while associating them in advance, the complexity at the time of manufacturing can be reduced.

  (5) The injection start command timing for the fuel injection valve 10 is variably set based on the measured value of the deviation amount between the injection start command timing for the fuel injection valve 10 and the actual timing. Thereby, the dispersion | variation in the injection characteristic resulting from an individual difference can be compensated still more suitably, and an output performance and an exhaust characteristic can be improved by extension.

  (6) The deviation amount measured in a state where the fuel pressure in the common rail 6 is set to a plurality of different values is stored in the ECU 50. As a result, it is possible to compensate for the variation in the deviation due to individual differences while appropriately taking into account the influence of the fuel pressure in the common rail 6.

  (7) The ECU 50 stores the correction amount of the fuel pressure in the common rail 6 based on the actually measured deviation amount. Thereby, the calculation load which ECU50 performs can be reduced.

  (8) The fuel injection valve 10 is provided with a QR code that stores the correction amount of the injection start command timing based on the actually measured deviation amount. Thereby, the association between the fuel injection valve 10 and the ECU 50 is facilitated. For this reason, since it is not necessary to manufacture them while associating them in advance, the complexity at the time of manufacturing can be reduced.

  (9) The fuel injection control device was applied to a diesel engine. In a diesel engine, variations in spray shape due to individual differences in fuel injection valves and the like tend to have a large effect on output performance and exhaust characteristics, and thus the above effects can be suitably achieved.

(Other embodiments)
The above embodiment may be modified as follows.

  -Instead of storing the correction amount of the fuel pressure in the common rail 6 based on the maximum value of the injection rate, instead of storing the correction value of the actual value of the injection rate in the QR code, the above (1), ( The effects of 2) and (4) can be obtained.

  (5), (6), (8) Even if the actual amount of deviation itself is stored in the QR code instead of storing the correction amount of the command timing based on the actual amount of deviation of timing. ) Can be obtained.

  -The injection characteristics are not limited to the maximum value of the injection rate and the deviation amount. For example, the fuel pressure in the common rail 6 may be variably set based on the actually measured value of the fuel injection amount that reflects individual differences of the fuel injection valves 10. Thereby, an injection rate etc. can be adjusted and the dispersion | variation in fuel injection amount can be compensated. In addition, in this case, the variation in the spray shape can be suitably suppressed as compared with the case where the energization time for the fuel injection valve 10 is expanded and contracted.

  ・ After calculating the correction amount of the fuel pressure in the common rail 6 based on the maximum value of the injection rate or calculating the correction amount of the command timing based on the deviation amount, the injection is still actually performed. If variation in the fuel amount remains, the energization operation time of the fuel injection valve 10 may be further corrected.

  In addition, the method for actually measuring the injection characteristics is not limited to the one exemplified in the first embodiment.

  -As a means to memorize | store the information about the individual difference of the fuel injection valve 10, a QR code is not restricted. For example, as described in Patent Document 1, the above means may be configured as a resistor provided in the fuel injection valve 10. Further, even when this means is provided in the ECU 50 instead of being provided in the fuel injection valve 10, the effects (1) to (3) and (5) to (7) can be obtained. At this time, not only the basic fuel injection control is corrected based on the information about the individual difference, but the basic control mode in the ECU 50 is adjusted in advance in consideration of the information based on the individual difference. May be. That is, for example, the ECU may be manufactured by previously adjusting the setting mode of the command timing and the setting mode of the fuel pressure in the common rail 6 based on information about individual differences.

  The means for controlling the fuel pressure in the common rail 6 is not limited to the fuel pump 4 or the pressure reducing valve 42. For example, the fuel pressure in the common rail 6 may be controlled by performing idle driving of the fuel injection valve 10. Here, in the idle driving, the electromagnetic solenoid 32 is energized to connect the back pressure chamber 20 and the low pressure fuel passage 24, and the nozzle needle 14 is separated from the needle seat portion 16 (fuel injection valve). This is performed by stopping the energization control to the electromagnetic solenoid 32 before 10 opens. Thereby, the fuel pressurized and supplied from the common rail 6 can be returned to the fuel tank 1 without being injected, and the fuel pressure in the common rail 6 can be controlled.

  ・ Other fuel injection valves are not limited to pressure balance type. The engine to which the fuel injection control device, the fuel injection valve, and the fuel injection control adjustment method according to the present invention are applied is not limited to a diesel engine.

The figure which shows the structure of one Embodiment of the fuel-injection control apparatus concerning this invention. The time chart explaining the dispersion | variation in the injection characteristic resulting from the individual difference of a fuel injection valve. The flowchart which shows the procedure of the process for compensating the dispersion | variation in the injection characteristic concerning the said embodiment. The time chart which shows the measurement aspect of the injection characteristic for performing the said correction | amendment. The figure which shows the measurement method of the injection characteristic concerning the said embodiment. The figure which shows the method of memorize | storing the correction amount of dispersion | variation in ECU. The flowchart which shows the procedure of the process concerning correction | amendment of the fuel pressure in the common rail in the said embodiment. 6 is a flowchart showing a procedure of processing related to correction of command timing in the embodiment. The time chart which shows the fuel-injection control aspect concerning the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel tank, 4 ... Fuel pump, 6 ... Common rail, 10 ... Fuel injection valve, 38 ... Plate, 42 ... Pressure reducing valve, 50 ... ECU.

Claims (5)

In a fuel injection control device for storing fuel pressurized and supplied by a fuel pump in a pressure accumulation chamber in a high pressure state, and injecting fuel stored in the pressure accumulation chamber via a fuel injection valve,
In the state where the pressure of the fuel supplied to one fuel injection valve is set to a plurality of different values, the fuel injection valve is set based on an actual measurement value of a difference between an injection start command timing and an actual timing for the one fuel injection valve. Storage means for storing the correction amount of the command timing for starting injection of the one fuel injection valve ,
Means for variably setting an injection start command timing for the one fuel injection valve based on a correction amount of the command timing;
The fuel injection control apparatus comprising: a. In a fuel injection control device for storing fuel pressurized and supplied by a fuel pump in a pressure accumulation chamber in a high pressure state, and injecting fuel stored in the pressure accumulation chamber via a fuel injection valve,
Storage means for storing the correction amount of the fuel pressure in the pressure accumulating chamber set based on the measured value of the maximum value of the fuel injection rate in the state where the pressure of the fuel supplied to the fuel injection valve is set to a plurality of different values. When,
In the state where the pressure of the fuel supplied to one fuel injection valve is set to a plurality of different values, the fuel injection valve is set based on an actual measurement value of a difference between an injection start command timing and an actual timing for the one fuel injection valve. Storage means for storing the correction amount of the command timing for starting injection of the one fuel injection valve,
The fuel pressure in the pressure accumulating chamber is controlled before fuel injection by the fuel injection valve based on the fuel pressure correction amount corresponding to each of the plurality of values for the pressure corresponding to the current fuel pressure in the pressure accumulating chamber. Means,
Means for variably setting an injection start command timing for the one fuel injection valve based on a correction amount of the command timing;
The fuel injection control apparatus comprising: a. The actual amount of deviation of the actual timing and the command timing for starting the injection for the first fuel injection valve, were made in the corrected fuel pressure by the correction amount of the fuel pressure according to claim 2 the fuel injection control according apparatus. The fuel injection control device according to claim 1, wherein the storage unit is provided in the fuel injection valve . The fuel injection control device according to any one of claims 1 to 4, wherein the fuel injection control device is mounted on a diesel engine .

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