JP7364410B2 - Fuel injection control device and control method for the fuel injection control device - Google Patents

Description

The present invention relates to a fuel injection control device and a method of controlling the fuel injection control device for injecting fuel into a cylinder of an internal combustion engine. In particular, the present invention relates to a fuel injection control device and a method of controlling the fuel injection control device that facilitates output adjustment during output inspection during engine manufacturing and improves the accuracy of fuel injection amount correction.

Conventionally, fuel injection valves have been used that are configured to inject fuel into the cylinders of an internal combustion engine by supplying fuel at a predetermined pressure and opening an injection hole through energization control. In this fuel injection valve, the valve opening time is determined based on the pressure of fuel supplied to the fuel injection valve and the target injection amount. Specifically, the opening time of the fuel injection valve is determined according to the target injection amount using information on standard injection characteristics that indicate the relationship between the standard injection amount and valve opening time, which is prepared in advance for each fuel supply pressure. is required.

In a fuel injection device using such a fuel injection valve, it is desired that fuel be injected in just the right amount for the required injection amount. For example, in the case of the fuel injection valve provided in the above-mentioned internal combustion engine, if the actual injection amount exceeds or is insufficient with respect to the target injection amount, there is a risk of deterioration of exhaust emissions and vehicle drivability.

By the way, the above-mentioned injection characteristics of fuel injection valves generally vary from fuel injection valve to fuel injection valve due to variations in processing accuracy during manufacturing. Therefore, systems have been proposed to correct this variation in injection characteristics. Specifically, during the manufacturing stage of the fuel injection valve, the difference between the reference injection amount and the actual injection amount at multiple inspection points is obtained, and the target injection amount is adjusted so that the actual injection amount at each inspection point becomes the reference injection amount. The amount is corrected (for example, see Patent Document 1).

International Publication No. 2011/039889

However, according to the technology disclosed in Patent Document 1, the actual injection amount of the fuel injector is corrected by comparing the reference injection amount and the actual injection amount, but the comparison between the reference injection amount and the actual injection amount is , which is usually performed at about four inspection points. That is, the actual injection amount is corrected by comparing the actual injection amount with the reference injection amount at a predetermined fuel pressure and the opening time of the fuel injection valve at each inspection point. In the operating range other than the inspection point, a correction amount is calculated by a statistical method based on the difference between the reference injection amount and the actual injection amount at each inspection point. Therefore, in an operating region other than the inspection point, a slight deviation may remain between the reference injection amount and the actual injection amount even after correction.

For these reasons, after the fuel injection valve is installed in the engine, the injection amount of the fuel injection valve is re-corrected during the engine inspection stage, mainly so that the output at the rated point becomes the target value. There is. This re-correction was not efficient because it had to be performed manually for each engine. In addition, since the re-correction is performed uniformly to increase or decrease the injection amount when the accelerator opening is fully open (full load), it is not corrected in areas other than full load.

The present invention was made in view of this situation, and provides a fuel injection control device and a fuel injection control device that facilitate output adjustment during output inspection during engine manufacturing and improve the accuracy of fuel injection amount correction. The present invention provides a control method.

In order to solve the above issues,
In a fuel injection control device that performs injection control of a fuel injection valve by determining a valve opening time according to a target injection amount using information on a reference injection characteristic indicating a relationship between a pre-stored valve opening time and a reference injection amount,
a basic injection amount correction unit capable of correcting the injection amount of the fuel injector by adding a basic correction amount calculated based on difference information between the reference injection amount and the actual injection amount to the target injection amount; and,
a first instruction injection amount acquisition unit that obtains a first instruction injection amount that is an instruction injection amount corresponding to a predetermined engine output test point;
a second commanded injection amount acquisition unit that acquires a second commanded injection amount that is a commanded injection amount at which the engine output at the output test point of the engine becomes a target value when the basic injection amount correction unit does not perform correction;
a first difference calculation unit that calculates a first difference that is a difference between the second instruction injection amount and the first instruction injection amount;
an additional correction injection amount calculation unit that corrects the basic correction amount based on the first difference;
A fuel injection control device is provided.

In addition, in order to solve the above problems,
Control of a fuel injection control device that performs injection control of a fuel injection valve by determining a valve opening time according to a target injection amount using information on a reference injection characteristic indicating a relationship between a pre-stored valve opening time and a reference injection amount. A method,
A basic injection amount correction unit corrects the injection amount of the fuel injection valve by adding a basic correction amount calculated based on difference information between the reference injection amount and the actual injection amount to the target injection amount. step and
a step in which the first instruction injection amount acquisition unit acquires a first instruction injection amount that is an instruction injection amount corresponding to a predetermined engine output test point;
A second instruction injection amount acquisition section acquires a second instruction injection amount that is an instruction injection amount at which the engine output at the output test point of the engine becomes a target value when the basic injection amount correction section does not perform correction. step and
a step in which a first difference calculation unit calculates a first difference that is a difference between the second commanded injection amount and the first commanded injection amount;
an additional correction injection amount calculation unit correcting the basic correction amount based on the first difference;
A method of controlling a fuel injection control device is provided.

According to the present invention, it is possible to facilitate output adjustment during output inspection during engine manufacture and to improve the accuracy of correcting the fuel injection amount.

1 is a diagram showing a configuration example of a fuel injection control device in an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a portion of the electronic control unit that constitutes the fuel injection control device, which is related to the implementation of the present invention. FIG. 3 is a diagram for explaining correction amounts at engine output inspection points. 3 is a subroutine flowchart showing injection amount correction according to the embodiment of the present invention. FIG. 3 is a diagram showing the relationship between engine speed Ne and fuel injection amount Q before implementation of the present invention. FIG. 3 is a diagram showing the relationship between engine speed Ne and fuel injection amount Q after implementation of the present invention.

Embodiments of the present invention will be described below with appropriate reference to the drawings. Note that the members, arrangement, etc. described below do not limit the present invention, and can be variously modified within the scope of the spirit of the present invention. Further, in each figure, the same reference numerals indicate the same elements, and the description thereof will be omitted as appropriate.

FIG. 1 shows the overall configuration of a fuel injection control device 10 according to this embodiment. The fuel injection control device 10 according to this embodiment is a pressure accumulation type fuel injection control device. The fuel injection control device 10 is a device for injecting fuel into a cylinder of an engine (not shown) mounted on a vehicle, and includes a fuel tank 1, a low pressure pump 11, a fuel filter 12, a high pressure pump 13, The main elements include a flow rate control valve 19, a common rail 15, a pressure control valve 23, a fuel injection valve 17, an electronic control unit 50 (ECU), and the like.

The low pressure pump 11 and the high pressure pump 13 are connected by a low pressure fuel passage 31, and the high pressure pump 13 and the common rail 15 and the common rail 15 and the fuel injection valve 17 are connected by high pressure fuel passages 33 and 35, respectively. Furthermore, return passages 37, 38, and 39 are connected to the high-pressure pump 13, the common rail 15, and the fuel injection valve 17, respectively, for returning surplus fuel that is not injected from the fuel injection valve 17 to the fuel tank 1.

The low-pressure pump 11 sucks up and pressure-feeds the fuel in the fuel tank 1, and supplies the fuel to the high-pressure pump 13 via the low-pressure fuel passage 31. This low-pressure pump 11 is an in-tank type electric pump provided in the fuel tank 1, and is operated by electric current supplied from a battery. However, the low pressure pump 11 may be provided outside the fuel tank 1, or may be provided integrally with the high pressure pump 13.

A flow control valve 19 is provided at the low-pressure fuel inlet portion of the high-pressure pump 13 to adjust the discharge amount of the high-pressure pump. The flow rate control valve 19 is an electromagnetic proportional control valve in which the stroke amount of the valve member is variable depending on the supplied current value, and the area of the fuel passage can be adjusted.

The high-pressure pump 13 pressurizes the fuel introduced via the flow control valve 19 by the low-pressure pump 11 and pumps it to the common rail 15 via the high-pressure fuel passage 33.

The common rail 15 accumulates high-pressure fuel pressurized by the high-pressure pump 13 and supplies the fuel to each fuel injection valve 17 connected via a high-pressure fuel passage 35. A rail pressure sensor 25 and a pressure control valve 23 are attached to this common rail 15.

The rail pressure sensor 25 detects the pressure within the common rail 15 (rail pressure). The sensor signal of the rail pressure sensor 25 is sent to the electronic control unit 50.

The pressure control valve 23 is used to adjust the rail pressure by adjusting the flow rate of high-pressure fuel returned from the common rail 15 to the fuel tank 1. The pressure control valve 23 is an electromagnetic proportional control valve in which the stroke amount of a valve member for opening and closing a fuel passage is variable depending on the amount of electricity supplied, and the area of the fuel passage can be adjusted. Furthermore, instead of the pressure control valve 23, a mechanical safety valve that opens when a predetermined pressure is reached may be used.

The fuel injection valve 17 includes a nozzle body provided with an injection hole, and a nozzle needle that opens and closes the injection hole by moving forward and backward. In the fuel injection valve 17, the injection hole is closed by applying back pressure to the rear end side of the nozzle needle, and the injection hole is opened by releasing the applied back pressure. As the back pressure control means for the fuel injection valve 17, an electrostrictive actuator equipped with a piezo element or an electromagnetic solenoid actuator is used.

The electronic control unit 50 is mainly composed of a microcomputer with a known configuration, and has storage elements such as RAM and ROM, and has a drive circuit for driving the fuel injection valve 17, a flow control valve 19, and a pressure control valve 23. Equipped with an energizing circuit for energizing. In addition to inputting the detection signal of the rail pressure sensor 25 to the electronic control unit 50, various detection signals such as engine rotation speed, accelerator opening, and fuel temperature are used for engine operation control and fuel injection control. It is intended to be entered in order to serve the user.

Further, the electronic control unit 50 executes output adjustment at the time of output inspection during engine manufacturing, according to the implementation of the present invention, based on a request from an operator via a tester or the like. Details will be explained later.

Next, a configuration example of the electronic control unit 50 for implementing the present invention will be described with reference to FIG. 2. FIG. 2 is a block diagram schematically showing the configuration of a portion of the electronic control unit 50 related to implementation of the present invention.

The electronic control unit 50 includes a receiving section 500, an engine rotation speed acquisition section 510, a basic injection amount correction section 520, a first instruction injection amount acquisition section 530, a second instruction injection amount acquisition section 540, and a first difference acquisition section 530. It includes a calculation section 550 and an additional correction injection amount calculation section 560.

The receiving unit 500 receives information from a worker via a tester or the like connected to the electronic control unit 50 when an output testing stage is entered during engine manufacturing. When the electronic control unit 50 receives the information that the output test stage has been entered, the electronic control unit 50 adjusts the engine output and performs additional correction of the fuel injection amount.

The engine rotation speed acquisition unit 510 acquires the engine rotation speed detected by a sensor (not shown).

The basic injection amount correction unit 520 corrects the fuel injection amount of the fuel injection valve 17 based on the correction amount set at the manufacturing stage. Specifically, the target injection amount is a value obtained by adding a basic correction amount, which will be described later, to the instruction injection amount for each operating condition of the engine. The correction of the fuel injection amount in the basic injection amount correction section 520 has been conventionally performed. Hereinafter, the fuel injection amount correction performed by the basic injection amount correction section 520 will be referred to as basic injection amount correction. Further, the correction amount of the fuel injection amount in the basic injection amount correction is referred to as the basic correction amount Q_iqa.

The calculation of the basic correction amount Q_iqa will be described in detail below. First, in the manufacturing stage of the fuel injection valve 17, the difference between the reference injection amount and the actual injection amount at a plurality of predetermined inspection points is obtained. The difference becomes the basic correction amount Q_iqa at the plurality of inspection points.

The above-mentioned multiple inspection points are the injection state corresponding to pilot injection (hereinafter also referred to as "PI point"), the injection state corresponding to idling (hereinafter also referred to as "ID point"), and the injection state under partial load (hereinafter also referred to as "ID point"). , also referred to as "EM point"), and an injection state corresponding to full load (hereinafter also referred to as "FL point").

In addition, the basic correction amount Q_iqa in the area other than the above-mentioned inspection points is related to the basic correction amount Q_iqa at any of the above-mentioned inspection points among the PI point, ID point, EM point, and FL point, and a statistical method is used at the development stage. Calculated by Specifically, during the development stage of the fuel injection valve 17, the reference injection amount and actual injection amount are determined for several dozen points of predetermined rail pressure and predetermined valve opening time for multiple fuel injection valves 17. The basic correction amount Q_iqa at the tens of points is calculated. Then, for each fuel injector 17, the correlation between the basic correction amount Q_iqa at the tens of points and the basic correction amount Q_iqa at any of the plurality of inspection points (PI point, ID point, EM point, FL point) is determined. Understand and calculate the coefficient. As a result, the basic correction amount Q_iqa at the dozens of points is calculated by multiplying the basic correction amount Q_iqa at any of the inspection points among the PI point, ID point, EM point, and FL point by the above coefficient. . For convenience, in the following description, the basic correction amount at the FL point may be referred to as Q_iqa_F.

Furthermore, at injection points other than the several tens of points mentioned above, the basic correction amount Q_iqa can be calculated by interpolation calculation or the like. This makes it possible to calculate the basic correction amount Q_iqa at other injection points from the basic correction amount Q_iqa at any one of the plurality of test points (PI point, ID point, EM point, FL point). can. Note that which injection point is associated with which inspection point can be determined in advance at the development stage of the fuel injection valve 17. Moreover, since the basic correction amount Q_iqa is calculated based on the difference between the reference injection amount and the actual injection amount, it can take both positive and negative values.

Information on the basic correction amount Q_iqa at each injection point is converted into a barcode and written on each fuel injection valve. After the fuel injection valves 17 are mounted on the engine, the barcode is read and the basic correction amount Q_iqa for each fuel injection valve 17 is stored in an appropriate area of the electronic control unit 50. That is, the electronic control unit 50 stores the injection performance (dispersion) of each fuel injection valve 17 and the corresponding basic correction amount Q_iqa via the bar code.

The first instructed injection amount acquisition unit 530 acquires the first instructed injection amount Q_tar_1, which is the instructed injection amount corresponding to the engine output test point. The first instructed injection amount Q_tar_1 is a basic correction calculated for each fuel injection valve 17 to the instructed injection amount corresponding to the engine output test point determined at the development stage of the fuel injection control device based on the reference injection characteristics. The amount Q_iqa is added. In the following description, the basic correction amount at the engine output test point may be referred to as Q_iqa_1.

Note that the basic correction amount Q_iqa at the engine output test point and the operating region around it is associated with the basic correction amount Q_iqa_F at the FL point. Therefore, the first basic correction amount Q_iqa_1, which is the basic correction amount at the engine output inspection point, is calculated by multiplying the basic correction amount Q_iqa_F at the FL point of each fuel injection valve 17 by a predetermined coefficient.

The second instructed injection amount acquisition unit 540 obtains the second instructed injection amount Qa, which is the instructed injection amount when the engine output reaches the target value, without performing the basic injection amount correction described above. Specifically, after the fuel injection valve 17 is installed in the engine, when the engine speed is increased to the output test point condition without performing basic injection amount correction during the engine output test stage, that is, The commanded injection amount when the engine output reaches the target value is acquired as the second commanded injection amount Qa. The second command injection amount Qa has the same value for each fuel injection valve 17 installed in the same engine.

The first difference calculation unit 550 calculates the difference between the second instructed injection amount Qa acquired by the second instructed injection amount acquisition unit 540 and the first instructed injection amount Q_tar_1 acquired by the first instructed injection amount acquisition unit 530. A certain first difference Q_cor is calculated. The first difference Q_cor is calculated for each fuel injection valve 17 and can take both positive and negative values.

As mentioned above, the first basic correction amount Q_iqa_1, which is the basic correction amount at the engine output inspection point, is calculated by a statistical method based on the basic correction amount Q_iqa_F at the FL point, so it is different from the originally required correction amount. It may shift. Q_cor corresponds to the deviation. That is, the sum of the first difference Q_cor and the first basic correction amount Q_iqa_1 corresponds to the basic correction amount Q_iqa originally required for each fuel injection valve 17 at the engine output test point.

The above-mentioned correction amount at the engine output test point will be explained with reference to FIG. 3. The example shown in FIG. 3 corresponds to a case where the fuel injection amount of the fuel injection valve 17 at the engine output test point is smaller than the reference injection characteristic, and the basic correction amount Q_iqa is also smaller than the value that should originally be.

Qz corresponds to the actual injection amount when a command injection amount corresponding to a predetermined engine output test point is given in a state where the basic injection amount correction is not performed. Q_iqa_1 indicates a first basic correction amount that is a basic correction amount at an injection point corresponding to an output test point of the engine.

The first difference Q_cor is the difference between the second instructed injection amount Qa and the first instructed injection amount Q_tar_1, and corresponds to the deviation of the first basic correction amount Q_iqa_1 from the original value. The present invention attempts to correct this deviation by using the first basic correction amount Q_iqa_1 and the first difference Q_cor at the engine output test point. Further, according to the present invention, the injection amount in the region where the basic correction amount Q_iqa is calculated in association with the basic correction amount Q_iqa_F at the FL point is also corrected.

The additional correction injection amount calculation unit 560 calculates the amount of the basic correction amount Q_iqa associated with the basic correction amount Q_iqa_F at the FL point in the basic injection amount correction for each fuel injector 17. The newly calculated FL point additional correction amount Q_iqa_F2 is used instead of the basic correction amount Q_iqa_F for the FL point that was previously used, and the additional corrected injection amount Q_iqa2, which is a new corrected injection amount to replace Q_iqa, is changed from the basic correction amount to Q_iqa. calculate.

The details of the process executed by the additional correction injection amount calculation unit 560 are shown below. First, in the area where the basic correction amount Q_iqa is calculated in association with the basic correction amount Q_iqa_F at the FL point, the basic correction amount Q_iqa_F at the FL point is calculated using statistical processing at each injection point. As described above, the basic correction amount Q_iqa at each injection point is calculated by multiplying by a predetermined coefficient. The additional correction injection amount calculation unit 560 calculates the additional correction injection amount Q_iqa2 using the FL point additional correction amount Q_iqa_F2, which is a value obtained by further correcting the basic correction amount Q_iqa_F at the FL point. Specifically, the additional corrected injection amount Q_iqa2 is calculated by multiplying the FL point additional correction amount Q_iqa_F2 by the above coefficient. That is,
(Additional corrected injection amount Q_iqa2) = (Q_iqa_F2) × (predetermined coefficient at each injection point)
Here, the FL point additional correction amount Q_iqa_F2 is the sum of the first basic correction amount Q_iqa_1, which is the basic correction amount at the engine output inspection point calculated at the manufacturing stage of each fuel injector 17, and the first difference Q_cor. , is calculated by dividing by the above coefficient.

This will be explained below using specific numerical values. Note that the following numerical values are provisional values for explanation, and in order to facilitate understanding, numerical values are used as simple as possible. First, the basic correction amount Q_iqa (that is, the sum of the first difference Q_cor and the first basic correction amount Q_iqa_1) required at the engine output test point is set to "6 (mg)". Further, the basic correction amount Q_iqa_F at the FL point calculated at the manufacturing stage of the fuel injection valve 17 is set to "2 (mg)". Similarly, the coefficient for calculating the first basic correction amount Q_iqa_1 at the engine output inspection point, which was calculated at the manufacturing stage of the fuel injection valve 17, is set to "1.2".

From the above, the first basic correction amount Q_iqa_1, which is the basic correction amount at the engine output inspection point, calculated at the manufacturing stage of the fuel injection valve 17 is:
(Q_iqa_F)×1.2=2×1.2=2.4(mg)
Met. Since the basic correction amount that is originally required is "(6 mg)," in this example, the basic correction amount at the engine output test point is insufficient by 6-2.4 = 3.6 (mg). Ta.

In order to correct this, the additional correction injection amount calculation unit 560 calculates the sum of the first basic correction amount Q_iqa_1, which is the basic correction amount, and the first difference Q_cor at the engine output inspection point by using the above-mentioned coefficient. By dividing by , the FL point additional correction amount Q_iqa_F2 is calculated. Specifically, Q_iqa_F2 is
((Q_iqa_1)+(Q_cor))/1.2=6/1.2=5(mg)
It is calculated as follows.

Further, the additional correction injection amount calculation unit 560 uses the above-mentioned FL point additional correction amount Q_iqa_F2 instead of Q_iqa_F in a region where the basic correction amount Q_iqa is calculated in association with the basic correction amount Q_iqa_F at the FL point, Calculate additional corrected injection amount Q_iqa2. That is, the additional correction injection amount calculation unit 560 multiplies the FL point additional correction amount Q_iqa_F2 calculated at the engine output inspection point by a predetermined coefficient to calculate the additional correction injection amount Q_iqa2 in the region. .

Note that the above calculation example corresponds to a case where the fuel injection amount of the fuel injection valve 17 at the engine output test point is smaller than the reference injection characteristic, and the basic correction amount Q_iqa is also smaller than the value that should originally be. , the additional correction in this embodiment is also effective in other cases. That is, when the fuel injection amount at the engine output test point is smaller than the reference injection characteristic and the basic correction amount Q_iqa is excessive, or when the fuel injection amount at the engine output test point is larger than the reference injection characteristic, and The additional correction in this embodiment is also effective when the basic correction amount Q_iqa is too small, or when the fuel injection amount at the engine output test point is larger than the reference injection characteristic and the basic correction amount Q_iqa is too large. be.

Next, the procedure for implementing the present invention will be explained with reference to the subroutine flowchart shown in FIG.

First, in step S102, the electronic control unit 50 recognizes that the engine has entered the output inspection stage during engine manufacture. Specifically, an operator uses a tester or the like to notify the electronic control unit 50 that the output testing stage has begun.

In subsequent step S104, the first instructed injection amount acquisition unit 530 acquires the first instructed injection amount Q_tar_1, which is the instructed injection amount corresponding to the engine output test point. The first commanded injection amount Q_tar_1 is the sum of the basic correction amount Q_iqa calculated for each fuel injection valve 17 to the commanded injection amount corresponding to the engine output test point predetermined based on the reference injection characteristics. It has become.

In step S106, the second instruction injection amount acquisition unit 540 determines the second instruction injection amount, which is the instruction injection amount when the engine output at the engine output inspection point reaches the target value, without performing basic injection amount correction. Obtain the quantity Qa.

In step S108, the first difference calculation unit 550 calculates a first difference Q_cor, which is the difference between the second instructed injection amount Qa obtained in step S106 and the first instructed injection amount Q_tar_1 obtained in step S104. do. Q_cor corresponds to the shortfall or excess of the basic correction amount Q_iqa at the engine output test point.

In step S110, the additional correction injection amount calculation unit 560 calculates the FL point additional correction amount Q_iqa_F2 from the information at the engine output test point using the method described above.

In step S112, the additional correction injection amount calculation unit 560 uses the FL point additional correction amount Q_iqa_F2 calculated at the engine output inspection point to determine the basic correction amount that has been associated with the basic correction amount Q_iqa_F at the FL point. An additional corrected injection amount Q_iqa2 is calculated for the region where Q_iqa has been calculated.

After this process is completed, in the region where the basic correction amount Q_iqa was calculated in association with the basic correction amount Q_iqa_F at the FL point, the value obtained by adding the additional corrected injection amount Q_iqa2 to the standard injection amount is set as the target injection. Quantitatively, fuel injection control is performed by an electronic control unit 50.

5 and 6 are diagrams for explaining engine speed and fuel injection amount in the implementation of the present invention. In FIGS. 5 and 6, the horizontal axis shows the engine rotation speed Ne, and the vertical axis shows the fuel injection amount Q.

FIG. 5 shows the engine speed Ne and the fuel injection amount Q before implementing the present invention, and a1 to a6 shown by solid lines are the fuel injection amount Q with respect to the engine speed Ne at a plurality of accelerator openings. shows. The accelerator opening degree increases from a1 to a6. Further, H1 indicated by a dashed line is a line called full Q limit. The full Q limit is an upper limit value of the instructed injection amount, which is set to prevent engine damage. The full Q limit is set for each engine specification. Further, the engine output test point is usually set above the full Q limit.

FIG. 6 is a diagram for explaining the engine speed Ne and the fuel injection amount Q after the present invention is implemented. In FIG. 6, the injection amount corrected by implementing the present invention is shown by a thick solid line. Note that FIG. 6 shows a case where the fuel injection amount at the engine output test point is smaller than the reference injection characteristic, and the basic correction amount Q_iqa is also the value that should be originally, which is a specific example given in the explanation for the additional correction injection amount calculation unit 560. A case is shown in which the present invention is implemented in a fuel injection valve 17 smaller than .

Q_tar_1 is a first commanded injection amount that is a commanded injection amount corresponding to the engine output test point before implementation of the present invention. Qa is a commanded injection amount at which the output at the engine output test point becomes the target value. By implementing the present invention, the commanded injection amount at the engine output test point changes from Q_tar_1 to Qa.

Furthermore, in other regions where the basic correction amount Q_iqa is calculated in association with the basic correction amount Q_iqa_F at the FL point, the full Q limit increases from H1 to H2 by calculating the additional corrected injection amount Q_iqa2. are doing. In other words, although the original full Q limit was H2, before the present invention was implemented, the electronic control unit 50 recognized that the full Q limit was H1. This is due to a deviation in the basic correction amount Q_iqa.

Further, even in a region where the fuel injection amount is lower than the full Q limit, there is a region where the additional corrected injection amount Q_iqa_2 is calculated, which is indicated by the thick solid line connecting a3, a4, and a5. That is, by implementing the present invention, the additional corrected injection amount Q_iqa2 is calculated even in the relatively high injection amount region at the accelerator opening degrees a3, a4, and a5, indicating that the commanded injection amount is increasing.

As described above, according to the present invention, it is possible to facilitate output adjustment during output inspection during engine manufacturing, and to improve accuracy of correcting the injection amount in the area around the output inspection point of the engine.

10: Fuel injection control device, 13: High pressure pump, 15: Common rail, 17: Fuel injection valve, 50: Electronic control unit, 510: Engine speed acquisition section, 520: Basic injection amount correction section, 530: First instruction injection Amount acquisition section, 540: Second instruction injection amount acquisition section, 550: First difference calculation section, 560: Additional correction injection amount calculation section

Claims (5)

In a fuel injection control device that performs injection control of a fuel injection valve by determining a valve opening time according to a target injection amount using information on a reference injection characteristic indicating a relationship between a pre-stored valve opening time and a reference injection amount,
a basic injection amount correction unit capable of correcting the injection amount of the fuel injector by adding a basic correction amount calculated based on difference information between the reference injection amount and the actual injection amount to the target injection amount; and,
a first instruction injection amount acquisition unit that obtains a first instruction injection amount calculated by adding the basic correction amount to the instruction injection amount based on the reference injection characteristic that corresponds to the engine output test point;
a second commanded injection amount acquisition unit that acquires a second commanded injection amount that is a commanded injection amount at which the engine output at the output test point of the engine becomes a target value when the basic injection amount correction unit does not perform correction;
a first difference calculation unit that calculates a first difference that is a difference between the second instruction injection amount and the first instruction injection amount;
an additional correction injection amount calculation unit that corrects the basic correction amount based on the first difference;
including fuel injection control equipment. The difference information is acquired under a plurality of predetermined operating conditions when manufacturing the fuel injection valve,
The basic injection amount correction section includes:
Calculating the basic correction amount based on the difference information in each operating condition for the region of the plurality of predetermined operating conditions,
The fuel according to claim 1, wherein for a region other than the plurality of predetermined operating conditions, the basic correction amount is calculated based on the difference information in any one of the plurality of predetermined operating conditions. Injection control device. The fuel injection control device according to claim 2, wherein the plurality of predetermined operating conditions include at least a location where the accelerator opening is fully open. According to claim 3, the correction by the additional correction injection amount calculation unit is performed for a driving region in which the basic correction amount is calculated based on the difference information calculated under a driving condition in which the accelerator opening is fully open. The fuel injection control device described. Control of a fuel injection control device that performs injection control of a fuel injection valve by determining a valve opening time according to a target injection amount using information on a reference injection characteristic indicating a relationship between a pre-stored valve opening time and a reference injection amount. A method,
A basic injection amount correction unit corrects the injection amount of the fuel injection valve by adding a basic correction amount calculated based on difference information between the reference injection amount and the actual injection amount to the target injection amount. step and
a step in which the first instructed injection amount acquisition unit obtains a first instructed injection amount calculated by adding the basic correction amount to the instructed injection amount based on the reference injection characteristic corresponding to the engine output test point; and,
A second instruction injection amount acquisition section acquires a second instruction injection amount that is an instruction injection amount at which the engine output at the output test point of the engine becomes a target value when the basic injection amount correction section does not perform correction. step and
a step in which a first difference calculation unit calculates a first difference that is a difference between the second commanded injection amount and the first commanded injection amount;
an additional correction injection amount calculation unit correcting the basic correction amount based on the first difference;
A control method for a fuel injection control device, including:

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