JP2000018076A - Control method of fuel injection pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct instrumental differences in a fuel injection pump so as to be surely and stably performable with limited data. SOLUTION: An EEPROM 8 is installed in a control unit 6, while a POM 5 recorded with those of first or third instrumental error compensation data DQ, DQ and DX showing characteristics inherent in a fuel injection pump 2 is installed at the side of the pump 2. Then, at a stage where an electrical connection is completed by a communication line 10, those of reference point data DQα, DQβ, and DQγ preset among data in the ROM 5 are read in the EEPROM 8, and thus compensation for instrumental errors in the fuel injection pump 2 is carried out with these reference point data DQα, DQβ, and DQγ.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a fuel injection pump in which fuel injection control of the fuel injection pump is controlled according to an electric signal.

[0002]

2. Description of the Related Art Conventionally, an actuator provided in a fuel injection pump for adjusting a fuel injection amount or the like is driven and controlled by a control signal from a control unit provided separately from the fuel injection pump. In the fuel injection device, various parameters indicating the operation state of the internal combustion engine combined with the fuel injection pump and the operation parameters of the fuel injection pump are input to the control unit, and are determined on the control unit side according to these parameters. The drive signal of the actuator necessary for obtaining the target fuel injection amount and / or the target fuel injection timing is output from the control unit.

In the case of such a control system, even if the fuel injection pumps are of the same type, machine differences occur due to errors in the components of the fuel pump or due to assembly errors. Needs to be corrected according to the difference between the fuel injection pumps that combine the two.

[0004] For example, Japanese Patent Publication No. 2-36776 discloses an adjusting element for adjusting variations in characteristics inherent to a fuel injection pump in a connector wired to an actuator or the like of the injection pump. By connecting the control unit via the connector, even when the combination of the fuel injection pump and the control unit is changed, the variation in the characteristics of the fuel injection pump can be substantially reduced without complicated mechanical adjustment, There is disclosed a configuration in which the compatibility between the fuel injection pump and the control unit can be kept good.

[0005]

However, in the above-mentioned prior art, it is necessary to provide adjusting elements on the fuel injection pump side in accordance with the number of adjustment points set on the characteristic curve. In addition to requiring a large space for a large number of adjusting elements, the setting of the adjusting elements may not be able to stably perform good control due to a change in the setting values of the adjusting elements due to an impact or aging. Had problems. In addition, the adjustment value may deviate significantly due to an adjustment error or the like, or the control amount may be incorrectly corrected in spite of the incorrect adjustment due to the occurrence of poor electrical contact, and the operation of the fuel injection pump may be stopped. There is also a problem that it cannot be performed correctly.

It is therefore an object of the present invention to provide a method for controlling a fuel injection pump which can solve the above-mentioned problems in the prior art.

[0007]

According to a first aspect of the present invention, a fuel injection control actuator provided in a fuel injection pump for an internal combustion engine is provided separately from the fuel injection pump. A fuel injection pump for controlling the fuel injection pump with required fuel injection characteristics by driving in accordance with an electrical signal from the control unit provided, the nonvolatile first writable in the control unit. And a second storage element storing a plurality of correction data corresponding to a characteristic difference characteristic of the fuel injection pump is provided on the fuel injection pump side,
When the electrical connection between the fuel injection pump and the control unit is completed, the plurality of correction data in the second storage element correspond to a plurality of predetermined reference points on the machine difference characteristic. The correction data is read into the first storage element as reference point correction data, and the control unit performs machine difference correction of the fuel injection pump using the reference point correction data so as to obtain the required fuel injection characteristics. A proposed method of controlling a fuel injection pump is proposed.

According to a second aspect of the present invention, in the control method for a fuel injection pump according to the first aspect, the machine difference characteristic is:
A fuel injection pump control method is proposed in which a target value correction amount characteristic of a fuel injection amount with respect to the rotation speed of the internal combustion engine is provided, and each of the correction data is data indicating a target value correction amount with respect to the rotation speed value of the internal combustion engine. Is done.

According to the invention of claim 3, claim 1 or 2
In the control method for a fuel injection pump described above, the machine difference correction obtains interpolation correction data at a point other than the reference point by performing an interpolation operation based on the reference point correction data, A fuel injection pump control method performed based on the correction data is proposed.

According to a fourth aspect of the present invention, in the fuel injection pump control method according to the first aspect, each value of the reference point correction data read into the first storage element is within a predetermined limit value range. Is determined, and a warning is issued when each value of the reference point correction data is not within a predetermined limit value range.

According to a fifth aspect of the invention, in the control method of the fuel injection pump according to the fourth aspect, when each value of the reference point correction data is not within a predetermined limit value range, the reference point correction data is further corrected. A control method of a fuel injection pump that interrupts reading of data is proposed.

According to a sixth aspect of the present invention, in the control method of the fuel injection pump according to the first aspect, a third storage element is further provided in the control unit, and an electrical connection between the fuel injection pump and the control unit is provided. When the connection is completed, the plurality of correction data in the second storage element is also read into the third storage element, and the reference point correction data or the plurality of correction data read into the third storage element is read. A method for controlling a fuel injection pump is proposed in which the machine difference correction of the fuel injection pump is performed by selectively using any one of the above to obtain the required fuel injection characteristics.

According to a seventh aspect of the present invention, in the fuel injection pump control method according to the sixth aspect, each value of the plurality of correction data read into the third storage element is within a predetermined limit value range. Is determined, and a warning is issued if each value of the plurality of correction data is not within a predetermined limit value range.

According to an eighth aspect of the present invention, in the control method of the fuel injection pump according to the seventh aspect, when each value of the plurality of correction data is not within a predetermined limit value range, the plurality of correction data is further adjusted. A control method of a fuel injection pump that interrupts reading of data is proposed.

According to a ninth aspect of the present invention, in the control method of the fuel injection pump according to the sixth aspect, the machine difference characteristic is:
A fuel injection pump control method is proposed in which a target value correction amount characteristic of a fuel injection amount with respect to the rotation speed of the internal combustion engine is provided, and each of the correction data is data indicating a target value correction amount with respect to the rotation speed value of the internal combustion engine. Is done.

According to a tenth aspect of the present invention, in the control method of the fuel injection pump according to the sixth or ninth aspect, the machine difference correction is performed by performing an interpolation operation based on the reference point correction data to thereby perform the operation other than the reference point. And a method for controlling the fuel injection pump, which is performed based on the reference point correction data and the interpolation correction data, is proposed.

According to an eleventh aspect of the present invention, in the control method of the fuel injection pump according to the sixth aspect, it is determined whether or not a plurality of required correction data are normally read into the third storage element. When it is determined that the reading has been performed normally, the machine error correction based on the plurality of correction data is performed, and when it is determined that the reading is not performed normally, the machine error correction based on the reference point correction data is performed. A method for controlling an injection pump is proposed.

According to a twelfth aspect of the present invention, in the fuel injection pump control method according to the eleventh aspect, the machine difference characteristic is a target value correction amount characteristic of the fuel injection amount with respect to the rotation speed of the internal combustion engine. A method of controlling a fuel injection pump is proposed in which each of the correction data is data indicating a target value correction amount for a rotation speed value of the internal combustion engine.

According to a thirteenth aspect of the present invention, in the control method of the fuel injection pump according to the eleventh or twelfth aspect, the machine difference correction performs an interpolation operation based on the reference point correction data. A method of controlling a fuel injection pump is proposed in which interpolation correction data at points other than the above is obtained and the correction is performed based on the reference point correction data and the interpolation correction data.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a fuel injection system configured to perform fuel injection control according to the method of the present invention. The fuel injection system 1 includes a fuel injection pump 2 for injecting and supplying fuel to an internal combustion engine (not shown).
A first actuator 4 for adjusting the fuel injection amount Q from the fuel injection pump 4 is a second actuator for adjusting the fuel injection timing θ from the fuel injection pump 2, and 5 is a fuel injection pump 2
Is a read-only memory (ROM) for recording the unique machine difference characteristic of the fuel injection pump 2, and the ROM 5 is fixed to an appropriate portion of the fuel injection pump 2 by an appropriate means such as screwing.

Reference numeral 6 denotes a control unit which constitutes the fuel injection system 1 in combination with the fuel injection pump 2, and is a one-chip type CPU 7, C for performing various control calculations.
EEPRO which is a writable nonvolatile memory for storing data for correction calculation in PU7
M8, and a driver 9 for driving the first actuator 3 and the second actuator 4 in accordance with a command from the CPU 7.

A communication line 10 for serial communication is connected between the fuel injection pump 2 and the control unit 6, and a required communication between the fuel injection pump 2 and the control unit 6 is performed via the communication line 10. Is transmitted and received.
The communication line 10 has a known configuration that can be detachably connected to the fuel injection pump 2 and the control unit 6 by an appropriate electrical connector.

The control unit 6 includes an accelerator sensor 11
An accelerator signal AC indicating the accelerator operation amount (accelerator opening) at that time and a rotation speed signal NE indicating the rotation speed N of the internal combustion engine (not shown) at that time from the rotation sensor 12 are input as operating parameters. . The accelerator signal AC and the rotation speed signal NE are taken in as digital data by the CPU 7 via the input / output interface circuit 13.

Next, a data structure for controlling the fuel injection amount Q and the fuel injection timing θ in the fuel injection system 1 shown in FIG. 1 will be described with reference to FIG. CPU
7, a ROM 7A for controlling the injection amount, which indicates the relationship between the rotational speed (N), the position of the sleeve (U) for adjusting the fuel of the first actuator 3, and the fuel injection amount (Q). The first reference map data MAP1 and the second reference map data MAP2 for controlling the injection timing indicating the relationship among the rotation speed (N), the fuel injection amount (Q), and the fuel injection timing (θ) are stored. The first reference map data MAP1 and the second reference map data MAP2 are prepared based on the design data of the fuel injection pump 2, and the difference between the individual fuel injection pumps occurring in the manufacturing process and the like is not described. It is not considered at all.

On the other hand, the ROM 5 stores unique data relating to differences between the fuel injection pumps 2 provided with the ROM 5. In the present embodiment, the first machine difference correction data DQ for controlling the injection amount, which is obtained based on the result of an actual test previously performed on the fuel injection pump 2.
And second machine difference correction data Dθ for injection timing control,
The three types of the third machine difference correction data DX relating to the uneven amount are RO
It is stored in M5.

The first machine difference correction data DQ includes a plurality of predetermined rotation speeds Ni (i = 1 to n) in the internal combustion engine.
Correction amount ΔQi (i = 1 to n) for each of
And among these n sets of data, each consisting of a rotational speed and a target value correction amount, i =
Three data of α, β, and γ are predetermined as reference point correction data DQα, DQβ, and DQγ in the first machine difference correction data DQ.

These reference point correction data DQα, DQ
β and DQγ are appropriately determined such that a target value correction amount at an arbitrary value of the rotation speed N can be calculated with a predetermined accuracy by an interpolation method based on these three reference point correction data.

As for the second machine error correction data Dθ and the third machine error correction data DX, data for machine error correction is prepared in exactly the same manner as in the case of the first machine error correction data DQ. Therefore, the same description will not be repeated for the second machine error correction data Dθ and the third machine error correction data DX.

The first machine difference correction data DQ, the second machine difference correction data Dθ, stored in the ROM 5 as described above,
When the electrical connection between the fuel injection pump 2 and the control unit 6 is completed, the third machine difference correction data DX
Is read into the RAM 7B in the CPU 7 and stored. As will be described later, at the same time, the respective reference point correction data DQα, DQβ, DQγ, Dθα, Dθβ, Dθ of the first to third machine error correction data DQ, Dθ, DX are simultaneously set.
γ, DXα, DXβ, and DXγ are read and stored in the EEPROM 8. Each control related to the injection amount control and the injection timing obtained by executing the control calculation for the injection amount control based on the first reference map data MAP1 and the second reference map data MAP2 stored in the ROM 7A in advance. The amount is the first to third machine difference correction data DQ,
It is corrected by Dθ and DX, respectively.

FIG. 3 shows this correction operation. In response to the accelerator signal AC and the rotational speed signal NE, the map calculation means 21 responds to the accelerator signal AC and the rotational speed signal NE to obtain the target injection amount Qt based on the first reference map data MAP1 and the second reference map data MAP2.
And a map calculation of the target injection timing θt is performed. The target injection amount Qt and the target injection timing θt are given to the correction data reading means 22. The correction data reading means 22 responds to the rotation speed signal NE and outputs the required machine difference correction data for the target injection amount Qt and the target injection timing θt obtained at that time to R
The data is selected and read from the first to third machine difference correction data DQ, Dθ, DX read in the AM 7B.

The correction means 23 corrects the target injection amount Qt and the target injection timing θt from the map calculation means 21 by the corresponding machine difference correction data output from the correction data reading means 22, and corrects each data. Fuel injection pump 2
And the fuel injection amount and the fuel injection timing are obtained as the target values at that time in consideration of the machine difference.

However, the first data stored in the ROM 5
Control when all of the third machine difference correction data cannot be read and stored in the RAM 7B, or
The fuel injection pump 2 and the control unit 6 are connected by a communication line 10 so as not to cause a trouble in the control before the reading of all the third machine difference correction data is completed,
When the operation of the fuel injection system 1 is started, the ROM
5 among a plurality of data for correcting the machine error, predetermined reference point correction data (i = i in each of the first to third machine error correction data DQ, Dθ, DX).
Only the three data α, β, and γ) are read and stored in the EEPROM 8.

Under a predetermined condition, the target injection amount Q
t and the target injection timing θt are corrected by the EEPR
This is performed based on the reference point correction data stored in the OM 8, whereby the first to third machine difference correction data DQ, Dθ, DX stored in the ROM 5 are read and stored in the RAM 7 </ b> B. In this case, it is possible to effectively prevent a failure in the control or a failure in the control before the reading of all of the first to third machine difference correction data DQ, Dθ, and DX is completed.

Next, referring to FIG. 4, three reference point correction data D stored in the EEPROM 8 for controlling the injection amount.
An example of a method for obtaining necessary correction data for machine difference correction by interpolation using Qα, DQβ, and DQγ will be described. In FIG. 4, the horizontal axis represents the rotation speed N, and the vertical axis represents the target value correction amount for correcting the machine difference. Here, based on the three reference point correction data DQα, DQβ, and DQγ, the rotation speed is Nα,
Target value correction amount ΔQα, ΔQ in each case of Nβ, Nγ
β and ΔQγ are known. In this case, the rotation speed N is Nα
In the following, the target value correction amount is determined to be ΔQα constant. In the range of Nα <N ≦ Nβ, ΔQα and ΔQβ
The target value correction amount at the required rotation speed value is calculated by linear interpolation using In the range of Nβ <N ≦ Nγ,
A target value correction amount at a required rotation speed value is calculated by linear interpolation using ΔQβ and ΔQγ. When N> Nγ, the target value correction amount is determined to be ΔQγ constant. The above interpolation method is an example, and is not limited to this method. Needless to say, another appropriate interpolation method may be used.

FIG. 5 shows the CP in the control unit 6 using the first machine difference correction data DQ stored in the ROM 5.
A specific example of the data correction processing for the injection amount control executed in U7 is shown in a functional diagram.

The running characteristic map calculator 31 calculates the rotation speed N
And map data corresponding to a characteristic in which a target value Qt of the fuel injection amount Q is set with respect to the accelerator operation amount Acc. In response to the accelerator signal AC and the engine speed signal NE, the travel characteristic map calculation unit 31 performs a map calculation of the target value Qt of the fuel injection amount Q at that time according to the map data. here,
If the value of the rotation speed N and / or the accelerator operation amount Acc does not match the set value of the map data, a target value Qt is calculated and output using interpolation calculation, and the target value Qt is calculated.
Is sent to the pump characteristic map calculation unit 32 as target fuel injection amount data.

The pump characteristic map calculation unit 32 calculates a target value Qt of the rotation speed N, the fuel injection amount Q, and the accelerator operation amount Ac.
By determining c (load state), pump characteristic map data for setting a governor command value based on these conditions is provided, and a map calculation is performed by using the pump characteristic map data. The governor command value is set by the pump characteristic map calculation unit 32. This governor command value is output as a target value for fuel injection. Note that R
In the OM 5, an error indicating a deviation from the standard value of the pump characteristics described above is stored as correction data (machine difference data).

On the other hand, the first correction map calculation unit 33
An individual correction value is output based on a plurality of correction data for machine difference correction stored in M7B. The second correction map calculation unit 34 performs an interpolation calculation based on the reference point correction data stored in the EEPROM 8 (see FIG. 4), and outputs an interpolation correction value based on the obtained interpolation correction data. .

The switch unit 35 selects either the individual correction value or the interpolation correction value according to the result of the determination by the control condition determination unit 36 and sends it to the addition unit 37. The adding unit 37 performs the machine difference correction by adding the individual correction value or the interpolation correction value from the switch unit 35 to the target value of the fuel injection output from the pump characteristic map calculating unit 32, and the machine difference is corrected. The target value is obtained. The output from the adder 37 is provided to the first actuator 3 via the driver 9 (see FIG. 1), whereby the fuel injection pump 2 is controlled in accordance with the machine difference data stored in the ROM 5. As a result, even if there is a difference between the fuel injection pumps 2, the operation of the internal combustion engine (not shown) is controlled with the predetermined fuel injection amount characteristics regardless of the difference.

FIG. 6 is a diagram for explaining an example of a method for determining whether the individual correction value or the interpolation correction value is selected by the switch unit 35.

When an ignition switch (not shown) is turned on for the first time, the switch section 35 is connected to the contact 35A, and the interpolation correction value is selected. (1) The data in the EEPROM 8 has been normally read and completed. (2) The accelerator operation amount is equal to or less than a certain set value. (3) In idle mode. (4) The engine is rotating (N ≠ 0). Is satisfied, the output of the AND gate 41 becomes “H” level, and the switch unit 35
Is switched to the contact 35B, and the individual correction value is selected.

(5) The data in the EEPROM 8 has been normally read and completed. (6) The start switch is OFF. (7) The engine is stopped (N = 0). Is satisfied, the AND gate 42
Becomes "H" level, and the switch unit 35
The contact is switched from 5A to the contact 35B, and the individual correction value is selected.

Therefore, in the state where either of the outputs of the AND gates 41 and 42 is at the "H" level, the output of the OR gate 43 becomes "H", and the switch unit 35 responds to the output from the OR gate 43 in response to the aforementioned output. It is switched as follows.

FIGS. 7 and 8 are flowcharts for explaining the operation of the control unit 6. FIG. The flowchart shown in FIG. 7 shows the reading operation of the reference value, and the flowchart shown in FIG. 8 shows the reading operation of the correction value executed subsequently.

When the operation of the control unit 6 is started, it is determined in step 51 whether or not the ROM 5 has been confirmed as a genuine product. The determination as to whether or not the product is genuine is made based on, for example, whether or not the reference point correction data stored in the ROM 5 is a predetermined one.

Step 51 is periodically executed at a predetermined time interval when the key switch is on. Step 51 is a step of checking whether or not a flag indicating the result of writing the normal data in the ROM 7A in the past is set. Therefore, as described below, when the flag is set, the determination result of step 51 is YES, the backup reading flow based on steps 52 to 64 is not executed, and the
You will jump to 1.

If the decision result in the step 51 is YES, the process enters a step 71 in FIG. If the decision result in the step 51 is NO, a step 52 is entered in which the reference point correction data (backup value) for the machine difference correction is stored in the EEP.
It is determined whether or not it exists in the ROM 8, and
If the decision result in the step 2 is NO, the process proceeds to a step 53, where RO
The correction data stored in M5 is read, and in step 54, a normal value confirmation process is performed to determine whether or not the correction data obtained by reading the data is a normal value. RO
M5 stores three sets of reference point correction data (for example, three points) as backup data. Then, three sets of data are read into the CPU 7, and a comparison is made at step 54 as to whether at least two sets of data match. At step 55, a determination is made according to the comparison result. Similar processing is performed in steps 61 and 62 described later.

If the data is confirmed to be normal in step 55, the determination result in step 55 is YES, and the process proceeds to step 56, where the data is compared with a previously recorded correction amount limiter, and the data in the ROM 5 is read. Confirm normal operation. That is, the control unit 6 considers the performance variation of the normally manufactured fuel injection pump, and sets upper and lower limit values of appropriate values beyond the range of the performance variation as a limit upper limit value and a limit lower limit value. Set it. Then, it is determined in step 57 whether each correction data in the ROM 5 exceeds the range defined by the upper limit value and the lower limit value, that is, whether it is within the correction amount limiter.

As described above, when the correction data stored in the ROM 5 is read by the control unit 6,
Check the read correction data with the correction amount limiter,
It is checked whether or not the read correction data exceeds the range of the performance variation of the fuel injection pump 2, and a warning is issued if the read correction data exceeds the range of the performance variation of the fuel injection pump 2. With such a configuration, even if the correction data is erroneously read for some reason, the problem that the correction amount becomes excessive and the control becomes unstable due to the correction can be reliably removed. As a result, a highly reliable control amount correction operation can be performed.

If it is determined in step 57 that the correction amount is not within the limiter, the determination result is NO, and the process proceeds to step 58, in which a warning process is performed, and then the execution of this program ends. In this case, in addition to the warning, ROM5
The reading of the correction data in the section may be interrupted.

If it is determined in step 57 that the correction amount is within the limiter, the determination result is YES, and the process proceeds to step 59, where data is written to the EEPROM 8, and the process proceeds to step 71.

If it is determined in step 55 that the reading is not normal, the process proceeds to step 64, in which a warning process is performed, and then the process proceeds to step 78. The warning process is specifically to save an “error code”, and after the warning process, the process jumps to step 78. Further, the processing in step 64 is executed three times including two retries, and
By executing the warning process consecutively, the error code is stored, and thereafter, only the backup process is performed. Also, reading of matrix data is not performed.

The reference point correction data (data of a predetermined number of points) is stored in the ROM 5, and the fuel injection pump 2 and the control unit 6 are shipped as a set when shipped from the factory. EEPROM8
, Reference point correction data of the corresponding fuel injection pump 2 has already been written. Therefore, when the determination result of step 52 is YES and the warning process of step 64 is performed, the process jumps to step 78 and the backup process is performed.

On the other hand, if the decision result in the step 52 is YES, a process similar to the steps 53 and 54 is executed in steps 60 and 61. Thereafter, if it is determined in step 62 that the reading is not normal, the process proceeds to step 71. On the other hand, if it is determined in step 62 that the data is normally read, the process proceeds to step 63, where the read correction data is compared with a backup value based on the reference point correction data existing in the EEPROM 8, and It is determined whether or not there is. If the decision result in the step 63 is YES
, The process proceeds to step 71, and if the decision result in the step 63 is NO, the process proceeds to a step 64.

In step 71, it is determined whether or not the matrix data has been read.
If it is O, the process proceeds to step 72, where the reading of matrix data and the presence or absence of an abnormality determination experience are determined.

If the decision result in the step 72 is NO,
In step 73, the data in the ROM 5 is read. In step 74, a process for confirming the normal value of the matrix data is performed. In step 71, it is determined whether the data has been read normally.

If the data in the ROM 5 has been normally read, the result of the determination in step 75 is YES, and in step 76 it is determined whether or not the switching condition shown in FIG. 6 is satisfied. When the switching condition shown in FIG. 6 is satisfied,
If the decision result in the step 76 is YES, a step 77 is made.
, Where the matrix data correction is performed, and the operation ends.

On the other hand, if the decision result in the step 76 is NO, the process proceeds to a step 78, in which a backup correction based on the reference point correction data is performed, and the operation ends. When the result of the determination at step 72 is YES, and when the result of the determination at step 75 is NO, step 78 is entered, and backup correction based on the reference point correction data is performed. If the decision result in the step 71 is YES, the process enters the step 76.

In the above description, the machine difference correction of the injection amount control according to the reference point correction data DQα, DQβ, DQγ of the first machine difference correction data DQ has been described. It can be easily understood that the machine difference correction of the injection timing can be performed in exactly the same manner based on the data.

[0061]

According to the present invention, as described above, even if the data is not completely read from the storage device for storing the machine error correction data provided on the fuel injection pump side to the control unit side, for example, Since the machine difference correction can be performed by reading only several reference point correction data, the reliability of control can be remarkably improved.

That is, when reading the machine difference correction data provided on the fuel injection pump side into the control unit, when the reading is not completed for some reason, or when it is desired to execute the machine difference correction even during the reading, the present invention is applied. According to this, since a plurality of reference point correction data are separately read into the control unit side, if these readings are not completed for some reason or machine reading is performed during reading, using these reference point correction data. be able to.

Since the absolute value level has been corrected in advance, even if the backup operation is performed using the reference point correction data, the absolute difference of the control start is determined after the end of reading all the machine error data to the control unit. The control can be smoothly performed.

Further, at the time of reading data from the storage element for storing the machine error correction data provided on the injection pump side to the control unit side, it is determined whether or not the value of the correction data is within a predetermined limit range. When the check is made and the value of the correction data is not within the predetermined limit range, a warning is issued, so even if a correction data reading error occurs for some reason, the correction value becomes excessively large, and the control is performed by the correction. The disadvantage of becoming unstable can be reliably removed. As a result, a highly reliable control amount correction operation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a fuel injection system configured to perform fuel injection control according to a method of the present invention.

FIG. 2 is an explanatory diagram for explaining a data configuration for fuel injection control in the fuel injection system shown in FIG. 1;

FIG. 3 is an explanatory diagram for explaining a machine difference correction calculation performed using machine difference correction data in a ROM provided on a fuel injection pump side.

FIG. 4 is an explanatory diagram for explaining an example of an interpolation method for obtaining necessary correction data based on reference point correction data read by a control unit.

FIG. 5 is a functional diagram for explaining a specific example of data processing for injection amount control executed in the control unit.

FIG. 6 is a configuration diagram illustrating a configuration of a control condition determination unit illustrated in FIG. 5;

FIG. 7 is a flowchart showing a part of a flowchart for explaining the operation of the control unit;

FIG. 8 is a flowchart showing a part of a flowchart for explaining the operation of the control unit.

[Explanation of symbols]

 Reference Signs List 1 fuel injection system 2 fuel injection pump 3 first actuator 4 second actuator 5 read-only memory (ROM) 6 control unit 7 CPU 8 EEPROM 9 driver 10 communication line DQ first machine difference correction data DQα, DQβ, DQγ Reference point correction Data Dθ Second machine difference correction data DX Third machine difference correction data

Continued on front page F term (reference) 3G084 AA01 BA14 CA07 DA21 DA27 EA11 EB02 EB08 EC03 FA10 FA13 FA17 FA36 3G301 HA02 JA17 JB09 JB10 KA07 KA28 LB13 LC10 MA18 NA08 NB11 NC01 NC02 NC06 NE17 NE19 PB03A PB05Z PE01Z

Claims (13)

[Claims] 1. A fuel injection control actuator provided in a fuel injection pump for an internal combustion engine is driven in accordance with an electric signal from a control unit provided separately from the fuel injection pump to obtain a required fuel injection characteristic. In a control method of a fuel injection pump for controlling the fuel injection pump, a first writable nonvolatile storage element is provided in the control unit, and a unique device of the fuel injection pump is provided on the side of the fuel injection pump. A second storage element storing a plurality of correction data corresponding to the difference characteristic is provided, and when the electrical connection between the fuel injection pump and the control unit is completed, the plurality of corrections in the second storage element are provided. Reading correction data corresponding to a plurality of predetermined reference points on the machine difference characteristic among the data as reference point correction data into the first storage element; Serial performed instrumental error correction of the fuel injection pump using the reference point correction data in the control unit, the control method of the fuel injection pump being characterized in that to obtain the desired fuel injection characteristics. 2. The machine-difference characteristic is a target value correction amount characteristic of a fuel injection amount with respect to the rotation speed of the internal combustion engine, and each of the correction data indicates a target value correction amount with respect to the rotation speed value of the internal combustion engine. The control method for a fuel injection pump according to claim 1, which is data. 3. The machine error correction obtains interpolation correction data at points other than the reference point by performing an interpolation operation based on the reference point correction data, and obtains interpolation correction data based on the reference point correction data and the interpolation correction data. Claim 1 or 2 performed by
The control method of the fuel injection pump described in the above. 4. It is determined whether each value of the reference point correction data read into the first storage element is within a predetermined limit value range, and each value of the reference point correction data is determined by a predetermined value. 2. The control method for a fuel injection pump according to claim 1, wherein a warning is issued when the value is not within the limit value range. 5. The control of the fuel injection pump according to claim 4, wherein when each value of the reference point correction data is not within a predetermined limit value range, reading of the reference point correction data is further interrupted. Method. 6. The control unit further includes a third storage element, and when the electrical connection between the fuel injection pump and the control unit is completed, the plurality of correction data in the second storage element is stored. Reading into the third storage element,
The difference between the reference point correction data and the plurality of correction data read into the third storage element is selectively used to perform the machine difference correction of the fuel injection pump to obtain the required fuel injection characteristics. The control method for a fuel injection pump according to claim 1, wherein 7. It is determined whether or not each value of the plurality of correction data read into the third storage element is within a predetermined limit value range, and each value of the plurality of correction data is determined to be a predetermined value. 7. The control method for a fuel injection pump according to claim 6, wherein a warning is issued when the value is not within the limit value range. 8. The control of the fuel injection pump according to claim 7, wherein when each value of the plurality of correction data is not within a predetermined limit value range, reading of the plurality of correction data is further interrupted. Method. 9. The machine-difference characteristic is a target value correction amount characteristic of the fuel injection amount with respect to the rotation speed of the internal combustion engine, and each of the correction data indicates a target value correction amount with respect to the rotation speed value of the internal combustion engine. The control method for a fuel injection pump according to claim 6, which is data. 10. The machine error correction obtains interpolation correction data at points other than the reference point by performing an interpolation operation based on the reference point correction data, and obtains interpolation correction data based on the reference point correction data and the interpolation correction data. The method for controlling a fuel injection pump according to claim 6 or 9, wherein the method is performed. 11. A method for determining whether a plurality of pieces of required correction data has been normally read into the third storage element, and when it is determined that the plurality of pieces of correction data have been correctly read, a machine error correction based on the plurality of pieces of correction data. 7. The control method for a fuel injection pump according to claim 6, wherein when it is determined that the reading is not performed normally, the machine difference is corrected based on the reference point correction data. 12. The machine-difference characteristic is a target value correction amount characteristic of the fuel injection amount with respect to the rotation speed of the internal combustion engine, and each of the correction data indicates a target value correction amount with respect to the rotation speed value of the internal combustion engine. The control method for a fuel injection pump according to claim 11, which is data. 13. The apparatus according to claim 1, wherein the machine error correction obtains interpolation correction data at a point other than the reference point by performing an interpolation operation based on the reference point correction data, and obtains interpolation correction data based on the reference point correction data and the interpolation correction data. 13. The control method for a fuel injection pump according to claim 11, wherein the control method is performed.