JP4151277B2 - Engine fuel injection control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine fuel injection control device.
[0002]
[Prior art]
In general, in a fuel injection control device for an engine, the amount of fuel injection is controlled by adjusting the time (injection time) for injecting fuel from an injector (fuel injection nozzle).
[0003]
On the other hand, injectors tend to deteriorate over time due to wear or the like with long-term use, and the injection efficiency tends to change. When the injection efficiency is changed in this way, the amount of fuel actually injected from the injector becomes different from the original required amount, and the accuracy of the injection amount control is lowered. Such a decrease in the accuracy of the injection amount control causes factors such as a deterioration in emission and an increase in noise.
[0004]
Therefore, conventionally, in order to suppress a decrease in the accuracy of the injection amount control due to the deterioration of the injector over time, for example, as shown in Japanese Patent Application Laid-Open No. 9-228876, the transition of the fuel injection amount (idle injection amount) during idling An apparatus for learning and correcting the injection amount command value based on the above has also been proposed.
[0005]
Incidentally, idle speed control (ISC) for adjusting the idle injection amount command value is performed so that the engine rotational speed is maintained at a predetermined rotational speed (idle rotational speed) during idling. Through such control, an appropriate amount of fuel is injected to maintain the idling speed regardless of the influence of various factors such as the deterioration of the injector with time. That is, for example, if the injection efficiency decreases due to deterioration of the injector over time, the idle injection amount command value is set to a value on the side that increases the fuel by that amount.
[0006]
In the apparatus described in the above publication, the transition of the idle injection amount command value, that is, its correction value is learned, and the normal injection amount command value is changed to the learned correction value during normal operation of the engine. Thus, the reduction in the accuracy of the fuel injection amount control is suppressed regardless of the deterioration of the injector over time. Such correction of the injection amount command value is particularly effective in a diesel engine that does not perform air-fuel ratio control.
[0007]
[Problems to be solved by the invention]
By the way, the value of the injection amount command value under the specific condition in which the control during idling as described above is performed also changes due to the influence of various factors other than the deterioration of the injector with time.
[0008]
For example, the load of an air conditioning compressor that is drivingly connected to the output shaft of the engine is a factor other than the change with time of the injector. Incidentally, it is known that the load on the compressor changes depending on the temperature in the passenger compartment or the difference between the temperature in the passenger compartment and the outside air temperature. Along with such a change in the operating load, the fuel injection amount required to maintain the predetermined operating state such as during idling changes, and the injection amount command value at that time also changes accordingly. become.
[0009]
Therefore, normally, in order to prevent the injection amount command value from being unnecessarily learned due to such load fluctuations of the compressor, learning of the idle injection amount command value is performed on the condition that the compressor is not operating. Yes. According to such a learning method, learning at a timing at which the idle injection amount command value changes due to a change in the compressor load is prohibited, and the accuracy of the learning correction value is also maintained.
[0010]
However, in this case, the opportunity to learn the index value is reduced, and the reliability of the learned value is lowered accordingly. In other words, the accuracy of fuel injection amount control may be reduced. In particular, when an air conditioner or the like is used for a long period of time while the compressor is in operation, learning during that period is also prohibited, and eventually the accuracy of fuel injection amount control is unavoidable.
[0011]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an engine fuel injection control device that can more suitably suppress a decrease in accuracy of injection amount control caused by deterioration of an injector over time or the like. It is to provide.
[0012]
[Means for Solving the Problems]
In the following, means for achieving the above object and its effects are described.
First, the invention according to claim 1 learns a correction amount for a fuel injection amount command value for maintaining the engine rotation speed at a predetermined idle rotation speed based on the determination of the engine idle stable state. In the engine fuel injection control device for correcting the fuel injection amount command value during each operation of the engine based on the learned correction amount, When the preconditions including that the engine is in an idle stable state are satisfied, when the air conditioner drive switch is set to ON, the compressor of the air conditioner is forcibly driven for the learning. On the condition that the change in the fuel injection amount command value that has occurred due to the drive of the compressor has become a predetermined time or more that is sufficiently reduced after the compressor is stopped. The learning is executed, and the stopped compressor is driven again after the learning is completed. Even when the precondition is satisfied, the learning is executed once after the precondition is satisfied. Is confirmed, the compulsory stoppage of the compressor for the learning and the execution of the learning are prohibited, and the learning is prohibited during the prohibited period. Assumptions is not satisfied, when the subsequent The precondition is satisfied again comprises learning control means for performing the learning in the manner This is the gist.
[0013]
According to the above configuration, when learning the correction amount When the air conditioner drive switch is on Even While the drive of the compressor that drives the air conditioner is temporarily stopped, there is a period of time over which the change in the fuel injection amount command value that has occurred with the drive of the compressor is sufficiently reduced after the compressor is stopped. The learning of the correction amount is prohibited by waiting for the passage of time. The learning of the correction amount can be accurately executed after eliminating the influence of the factor. As a result, it becomes possible to suitably increase the learning amount of the correction amount and improve its learning accuracy, and more appropriately to suppress the decrease in the accuracy of the injection amount control due to the deterioration of the injector over time. It becomes possible.
[0024]
Claims 2 The invention described in claim 1 In the fuel injection control device for an engine described above, the gist thereof is that the engine is a common rail type diesel engine.
[0025]
Normally, in a common rail type diesel engine, since air-fuel ratio control is not performed, if the injection efficiency is reduced due to the deterioration of the injector over time as described above, the accuracy reduction in the injection amount control is noticeable. . In this regard, according to the above configuration, in such a common rail type diesel engine, it is possible to suitably suppress a decrease in accuracy of the injection amount control.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.
[0027]
FIG. 1 shows a schematic configuration of a system related to fuel injection of a common rail type diesel engine mounted on a vehicle in the present embodiment.
As shown in FIG. 1, the diesel engine 1 is provided with a plurality of cylinders (four cylinders in the present embodiment) # 1 to # 4, and the combustion chambers of the cylinders # 1 to # 4 are provided. An injector 2 for injecting fuel is disposed. Fuel injection from the injector 2 to the cylinders # 1 to # 4 of the engine 1 is controlled by turning on and off the electromagnetic valve 3 for injection control.
[0028]
The injector 2 is connected to a common rail 4 serving as a pressure accumulating pipe common to each cylinder. Basically, the fuel in the common rail 4 flows from the injector 2 to the engine 1 while the electromagnetic valve 3 for injection control is open. The fuel is injected into each cylinder # 1 to # 4. The common rail 4 continuously accumulates fuel having a relatively high pressure that enables such fuel injection.
[0029]
The common rail 4 is connected to a discharge port 6 a of a supply pump 6 through a supply pipe 5. A check valve 7 is provided in the middle of the supply pipe 5. The check valve 7 allows fuel supply from the supply pump 6 to the common rail 4, and fuel from the common rail 4 to the supply pump 6. The reverse flow of is controlled.
[0030]
The supply pump 6 is connected to the fuel tank 8 through the suction port 6b, and a filter 9 is provided in the middle thereof. The supply pump 6 is driven by reciprocating a plunger by a cam (not shown) synchronized with the rotation of the engine 1. As a result, the supply pump 6 sucks fuel from the fuel tank 8 through the filter 9, raises the fuel to a required predetermined pressure, and supplies the fuel to the common rail 4.
[0031]
Further, a pressure control valve 10 is provided in the vicinity of the discharge port 6 a of the supply pump 6. The pressure control valve 10 closes its valve body in response to the ON signal, and allows the supply of fuel from the discharge port 6a toward the common rail 4. The pressure control valve 10 opens its valve body in response to the off signal, and surplus fuel that is not discharged from the discharge port 6a is supplied from the return port 6c provided in the supply pump 6 through the return pipe 11 to the fuel. It is designed to return to the tank 8. The fuel pressure (and hence the discharge amount) discharged from the discharge port 6a to the common rail 4 side is adjusted by the on / off control of the pressure control valve 10.
[0032]
Further, the common rail 4 is provided with a relief valve 12, and for example, when the fuel pressure in the common rail 4 increases excessively, the relief valve 12 is opened. As a result, the high-pressure fuel in the common rail 4 is returned to the fuel tank 8 via the return pipe 11, and the pressure in the common rail 4 is lowered.
[0033]
Further, in the present embodiment, the injector 2 promotes ignition prior to performing the main amount of fuel injection (“main injection”) related to generation of engine output for each of the cylinders # 1 to # 4. It is possible to inject a small amount of fuel ("pilot injection") to form a combustion environment.
[0034]
On the other hand, the engine 1 is provided with the following various sensors and the like in order to detect its operating state. That is, an accelerator sensor 21 is provided in the vicinity of an accelerator pedal (not shown) for detecting the amount of depression (accelerator opening ACC). The cylinder block of the engine 1 is provided with a water temperature sensor 22 for detecting the temperature of the cooling water flowing through the cylinder block. Further, the intake passage 13 of the engine 1 is provided with an intake pressure sensor 23 for detecting the pressure (intake pressure PM) of air sucked into the cylinders # 1 to # 4.
[0035]
In addition, a crank angle sensor 24 is provided in the vicinity of a pulsar provided on a crankshaft (not shown) of the engine 1. Further, the rotation of the crankshaft is transmitted to a camshaft (not shown) for opening / closing the intake valve 31 and the exhaust valve 32 via a timing belt or the like. The camshaft is set to rotate at a rotational speed that is 1/2 of the crankshaft. A cam angle sensor 25 is provided in the vicinity of the pulsar provided on the camshaft. In the present embodiment, the engine rotation speed NE, the crank angle, the cam angle, and the top dead center of the piston in each of the cylinders # 1 to # 4 are calculated from the pulse signals output from both the sensors 24 and 25 ( The cylinder is discriminated).
[0036]
The engine 1 is also provided with a compressor 33 that drives the air conditioner. The rotation of the crankshaft is also transmitted to the compressor 33 via a timing belt or the like. Further, an air conditioner switch 26 is provided in the vehicle interior. When the air conditioner switch 26 is turned on by the occupant, the compressor 33 is driven, while when the air conditioner switch 26 is turned off, the driving of the compressor 33 is stopped.
[0037]
Further, in the present embodiment, these various controls including the operating state of the engine 1 are collectively performed through an electronic control unit (ECU) 40. The electronic control unit 40 is configured to operate the electromagnetic valve 3 and the electromagnetic valve 3 according to the operating conditions of the engine 1 based on detection signals from the accelerator sensor 21, the water temperature sensor 22, the intake pressure sensor 23, the crank angle sensor 24, the cam angle sensor 25, and the like. The pressure control valve 10 and the relief valve 12 are controlled. Further, as part of such control, the electronic control unit 40 controls the fuel injection from the injector 2 and controls the fuel injection amount command value so that the engine rotational speed during idling is the idle rotational speed (the ISC). ). Furthermore, the electronic control unit 40 learns, as the learning correction value Qd, the correction amount for the fuel injection amount command value under a specific condition such as the compressor 33 not operating during the execution of the ISC. In the fuel injection control, the fuel amount injected from the injector 2 is corrected based on the learned learning correction value Qd, so that an error in the fuel injection amount accompanying the deterioration with time of the injector 2 is compensated.
[0038]
Hereinafter, such fuel injection control will be specifically described.
In this fuel injection control, in addition to “normal injection” for injecting a required amount of fuel at a time, “divided injection” for injecting the required amount of fuel divided into “pilot injection” and “main injection” twice. Is done.
[0039]
The fuel injection control in the normal injection is performed as follows. That is, first, the electronic control unit 40 calculates the fuel injection amount (final injection amount Qf) and the fuel injection timing according to the operating conditions of the engine 1. Further, the target injection amount Qt is calculated by correcting the calculated final injection amount Qf based on the learning correction value Qd. Further, the injection time Tq required for the injection of the amount corresponding to the calculated target injection amount Qt is calculated according to the engine rotational speed NE and the injection pressure (pressure of fuel accumulated in the common rail 4) at that time. .
[0040]
When the fuel injection timing calculated here is reached, the electronic control unit 40 opens the electromagnetic valve 3 of the injector 2 and starts injection of the high-pressure fuel supplied from the common rail 4 into the cylinders # 1 to # 4. To do. After that, the electromagnetic valve 3 is kept open for the calculated injection time Tq to perform a required amount of fuel injection, and then the electromagnetic valve 3 is closed to terminate the fuel injection.
[0041]
On the other hand, in fuel injection control during split injection, the electronic control unit 40 distributes the calculated final injection amount Qf to the final pilot injection amount Qfp and the final main injection amount Qfm. Further, the target pilot injection amount Qtp and the target main injection amount Qtm are respectively calculated by correcting both the injection amounts Qfp and Qfm separately based on the learning correction value Qd. Furthermore, the injection time in both injections according to the engine speed NE and the injection pressure at that time, that is, the pilot injection time Tqp and the main injection time Tqm are calculated.
[0042]
Then, when the calculated fuel injection timing comes, the electronic control unit 40 opens the solenoid valve 3 for the pilot injection time Tqp and supplies a minute amount of fuel corresponding to the calculated target pilot injection amount Qtp to each cylinder #. After the injection to 1 to # 4, the electromagnetic valve 3 is once closed. Then, after a predetermined period has elapsed, the electromagnetic valve 3 is opened again, and fuel injection is resumed. Thereafter, the solenoid valve 3 is opened for the main injection time Tqm, and fuel for the target main injection amount Qtm is injected, and then the fuel injection is terminated.
[0043]
By the way, if learning of the learning correction value Qd is executed on condition that the compressor 33 is not operating, the learning execution opportunity decreases, and the accuracy of the fuel injection control may be reduced accordingly. That's right.
[0044]
Therefore, in the present embodiment, the compressor 33 is driven when the air conditioner switch 26 is turned on under specific conditions including the idling stable state in order to suppress such a decrease in the accuracy of the fuel injection control. The learning correction value Qd is learned after being temporarily stopped. The temporary stop of the compressor 33 is canceled after the learning is completed. In other words, the compressor 33 is restarted after the learning is completed.
[0045]
As a result, even when the compressor 33 is being driven when learning the learning correction value Qd, the learning can be executed after eliminating the influence of the load fluctuation of the compressor 33 described above. Therefore, the learning accuracy of the learning correction value Qd can be increased by that amount, and the learning accuracy can be improved. As a result, the deterioration of the accuracy of the fuel injection control caused by the deterioration of the injector 2 over time can be suppressed. become able to.
[0046]
Hereinafter, a detailed processing procedure of each process related to the fuel injection control including the learning process of the learning correction value Qd will be described with reference to the flowcharts shown in FIGS.
[0047]
2 shows the processing procedure of the learning processing of the learning correction value Qd, FIG. 3 shows the processing procedure of the temporary stop processing of the compressor 33, and FIG. 4 shows the processing procedure of the injection time calculation processing. Further, the series of processes shown in these flowcharts are repeatedly executed by the electronic control device 40 with a predetermined period.
[0048]
Here, first, the processing procedure of the learning process of the learning correction value Qd will be described with reference to FIG.
As shown in FIG. 2, in this process, first, it is determined whether or not a precondition for executing learning of the learning correction value Qd is satisfied (step S100). Specifically, it is determined that the precondition is satisfied when all of the following (condition a) to (condition c) are satisfied.
(Condition a) An idle stable state.
(Condition b) The fluctuation amount of the engine rotational speed NE is within a predetermined range.
(Condition c) The variation amount of the fuel injection amount command value is within a predetermined range.
[0049]
If it is determined that any one of these (condition a) to (condition c) is not satisfied (step S100: NO), after the air conditioner cut permission flag is turned on (step S101) ), This process is temporarily terminated. The air conditioner cut permission flag is a flag that is turned off (step S110) when learning of the learning correction value Qd is completed through the following processing (steps S102 to S108). That is, it can be determined that learning of the learning correction value Qd has not yet ended after the above precondition is satisfied when the air conditioner cut permission flag is “ON”.
[0050]
Thereafter, the execution of this process is repeated, and when it is determined that all of the above (condition a) to (condition c) are satisfied (step S100: YES), the air conditioner cut permission flag is “ON”. It is determined whether or not it has been performed (step S102). If it is determined that the air conditioner cut permission flag is “off” (step S102: NO), learning of the learning correction value Qd has already ended after the above preconditions are satisfied, The processing is temporarily terminated on the assumption that the learning need not be executed.
[0051]
On the other hand, when it is determined that the air conditioner cut permission flag is “ON” (step S102: YES), it is determined that learning of the learning correction value Qd has not ended yet, and then the compressor 33 operates. Is determined (step S103). If it is determined that the compressor 33 is operating (step S103: YES), the air conditioner cut request flag is turned “on” (step S104). The air conditioner cut request flag is a flag that is referred to when determining whether or not to temporarily stop the driving of the compressor 33 in a temporary stop process (FIG. 3) described in detail later. Specifically, when the air conditioner cut request flag is “ON”, the driving of the compressor 33 is temporarily stopped. This air conditioner cut request flag is also a flag that is “off” after the learning of the learning correction value Qd is completed, like the air conditioner cut permission flag.
[0052]
At the same time, the learning prohibition flag is turned “ON” (step S105). This learning prohibition flag is a flag used to prohibit learning of the learning correction value Qd when the flag is “ON”.
[0053]
On the other hand, when the air conditioner switch 26 is “off”, or when the drive of the compressor 33 has already been paused, that is, when it is determined that the compressor 33 is not operating (step S103: NO), The learning prohibition flag is turned “OFF” (step S106).
[0054]
Then, after the air conditioner cut request flag and the learning prohibition flag are appropriately operated as described above, it is determined whether or not both of the following (condition d) and (condition e) are satisfied (step S107).
(Condition d) A predetermined time α or more has elapsed after the drive of the compressor 33 is stopped. The predetermined time α is obtained by an experiment or the like after the drive of the compressor 33 is stopped until the change in the fuel injection amount command value that has been caused by the drive is sufficiently reduced. Thus, it is stored in advance in the electronic control unit 40.
(Condition e) The learning prohibition flag is “off”.
[0055]
Then, when it is determined that one of these (condition d) and (condition e) is not satisfied (step S107: NO), this processing is temporarily ended. Thereafter, this processing is repeated, and when both (condition d) and (condition e) are satisfied (step S107: YES), learning of the learning correction value Qd based on the correction amount of the fuel injection amount command value described above is learned. Is executed (step S108).
[0056]
Then, after the air conditioner cut request flag is “off” (step S109), and the air conditioner cut permission flag is “off” (step S110), the process is temporarily terminated.
[0057]
Next, with reference to FIG. 3, the processing procedure of the temporary stop processing of the compressor 33 will be described.
As shown in FIG. 3, in this process, it is first determined whether or not the air conditioner cut request flag is “ON” by the learning process (step S200).
[0058]
When it is determined that the air conditioner cut request flag is “ON” (step S200: YES), the drive of the compressor 33 is temporarily stopped (step S201). On the other hand, when it is determined that the air conditioner cut request flag is “OFF” (step S200: NO), the temporary stop of the drive of the compressor 33 is released (step S202). As described above, after the driving of the compressor 33 is temporarily stopped and released, the processing is temporarily terminated.
[0059]
Next, with reference to FIG. 4, the process procedure of the injection time calculation process will be described.
As shown in FIG. 4, in this process, first, a final injection amount Qf suitable for the operating state of the engine 1 at this time is calculated based on the engine speed NE, the accelerator opening ACC, the intake pressure PM, and the like. (Step S300).
[0060]
Thereafter, the target injection amount is calculated based on the final injection amount Qf and the learning correction value Qd in the above-described manner (step S301). That is, when “normal injection” is selected in the fuel injection control, the target injection amount Qt is calculated. On the other hand, when the “split injection” is selected in the fuel injection control, the target pilot injection amount Qtp and the target main injection amount Qtm are respectively calculated.
[0061]
After that, the injection time required for the injection of the amount corresponding to the target injection amount is calculated according to the engine speed NE, the injection pressure, etc. (step S302). That is, at the time of normal injection, an injection time Tq required for injection of an amount corresponding to the target injection amount Qt is calculated. On the other hand, at the time of split injection, an injection time Tqm required for an amount corresponding to the target main injection amount Qtm and an injection time Tqp required for an amount corresponding to the target pilot injection amount Qtp are calculated. Thereafter, this process is temporarily terminated.
[0062]
Hereinafter, how each process described above is performed will be described with reference to a timing chart shown in FIG.
In addition, FIG. 5 has shown the transition about each item described below, respectively.
(A) Status of establishment of preconditions.
(B) The operating state of the air conditioner cut request flag.
(C) The operating state of the air conditioner cut permission flag.
(D) Driving state of the compressor 33.
(E) Elapsed time after the drive of the compressor 33 is stopped.
[0063]
As shown in FIG. 5A, when the above preconditions are not satisfied (before timing t1), the air conditioner cut request flag is “off” as shown in FIG. 5B. At this time, the air conditioner cut permission flag is “ON”. At this time, learning of the learning correction value Qd is not executed. That is, in the fuel injection control, when the amount of fuel injected from the injector 2 is corrected, the learning correction value Qd learned previously is used.
[0064]
After that, as shown in FIG. 5A, when the precondition is satisfied (timing t1), the air conditioner cut request flag is turned “ON” as shown in FIG. 5B. At this time, the drive of the compressor 33 is temporarily stopped as shown in FIG. 5D, and the elapsed time after the stop of the drive of the compressor 33 is counted as shown in FIG. 5E. Is started.
[0065]
Then, as shown in FIG. 5 (e), when the elapsed time reaches a predetermined time α (timing t2), learning of the learning correction value Qd is executed. When the learning ends (timing t3), the air conditioner cut permission flag and the air conditioner cut request flag are both turned off as shown in FIGS. 5B and 5C. At this time, the compressor 33 is restarted as shown in FIG. In the subsequent fuel injection control, when the amount of fuel injected from the injector 2 is corrected, the learning correction value Qd newly learned at this time is used.
[0066]
As described above, according to the present embodiment, the effects described below can be obtained.
(1) In the present embodiment, when the air conditioner switch 26 is turned on under specific conditions, the learning correction value Qd is learned after the drive of the compressor 33 is temporarily stopped. I tried to run. For this reason, the learning opportunity of the learning correction value Qd can be suitably increased to improve the learning accuracy, and hence the accuracy of fuel injection control due to the deterioration of the injector 2 over time is suitably suppressed. Will be able to.
[0067]
(2) According to the present embodiment, since the air-fuel ratio control is not performed, when the injection efficiency is reduced due to deterioration with time of the injector 2 or the like, the common rail type in which the accuracy reduction of the fuel injection control appears remarkably In the diesel engine 1, it is possible to suitably suppress a decrease in accuracy of the fuel injection control.
[0068]
The above embodiment may be modified as follows.
In the above embodiment, the learning correction value Qd is learned after the drive of the compressor 33 is temporarily stopped. Instead, the load of the compressor 33 is temporarily fixed. The learning may be executed. In such a configuration, the compressor 33 is driven even when the air conditioner switch 26 is turned on when learning the learning correction value Qd. However, since the degree of change in the fuel injection amount command value due to the influence can be estimated in advance, the learning correction value Qd is learned while taking the estimated change into account. The learning correction value Qd can be learned with high accuracy. Therefore, even with such a configuration, it is possible to suitably suppress a decrease in the accuracy of the fuel injection control caused by the deterioration of the injector 2 over time.
[0069]
In the above embodiment, the present invention is applied to the engine 1 provided with the compressor 33. However, the present invention is not limited to this. In short, the present invention is applied to an auxiliary machine that uses an engine as a drive source, such as a viscous heater, and has an auxiliary machine that changes the fuel injection command value due to the influence of factors other than engine torque. It is possible. In such a configuration, when the auxiliary machine is driven when learning the learning correction value Qd, the driving of the auxiliary machine is temporarily stopped or the load of the auxiliary machine is temporarily fixed. The above learning may be executed.
[0070]
-Moreover, the application object of this invention is not restricted to the fuel-injection control apparatus provided with the auxiliary machine which uses an engine as a drive source. In short, the present invention can be applied to any apparatus that has a factor that prohibits execution of the learning correction value Qd when learning, and has a factor that causes the fuel injection amount command value to change depending on factors other than engine torque. It is. In such a device, when a factor prohibiting the execution of the learning correction value Qd is active during learning of the learning correction value Qd, this factor is temporarily deactivated, or the influence of this factor is temporarily affected. The learning may be performed in a fixed manner.
[0071]
In addition, in the above embodiment, the present invention is applied to a common rail type diesel engine. Is possible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of an engine fuel injection control apparatus according to the present invention.
FIG. 2 is a flowchart showing a processing procedure for learning learning correction values.
FIG. 3 is a flowchart showing a processing procedure for processing for temporarily stopping driving of the compressor;
FIG. 4 is a flowchart showing a processing procedure for processing for calculating an injection time.
FIG. 5 is a timing chart showing an example of a processing mode for each processing related to fuel injection control according to the embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Injector, 3 ... Solenoid valve, 4 ... Common rail, 5 ... Supply piping, 6 ... Supply pump, 6a ... Discharge port, 6b ... Suction port, 6c ... Return port, 7 ... Check valve, 8 ... Fuel tank, 9 ... Filter, 10 ... Pressure control valve, 11 ... Return pipe, 12 ... Relief valve, 13 ... Intake passage, 21 ... Accelerator sensor, 22 ... Water temperature sensor, 23 ... Intake pressure sensor, 24 ... Crank angle sensor, 25 ... Cam angle sensor, 26 ... Air conditioner switch, 31 ... Intake valve, 32 ... Exhaust valve, 33 ... Compressor, 40 ... Electronic control unit.

Claims (2)

Based on the determination of the engine idle stable state, a correction amount for the fuel injection amount command value for maintaining the engine rotation speed at a predetermined idle rotation speed is learned, and the engine is based on the learned correction amount. In the engine fuel injection control device for correcting the fuel injection amount command value in each operation of
When the preconditions including that the engine is in an idle stable state are satisfied, when the air conditioner drive switch is set to ON, the compressor of the air conditioner is forcibly driven for the learning. On the condition that the change in the fuel injection amount command value that has occurred due to the drive of the compressor has become a predetermined time or more that is sufficiently reduced after the compressor is stopped. The learning is executed, and after the learning is completed, the stopped compressor is driven again,
Even when the precondition is satisfied, when it is confirmed that the learning has been executed once after the precondition is satisfied, the forced driving of the compressor for the learning is stopped and the learning is stopped. Fuel for an engine characterized by comprising learning control means for prohibiting execution, and when the precondition is not satisfied during the prohibited period, and the precondition is satisfied again after that, Injection control device. The engine fuel injection control device according to claim 1, wherein the engine is a common rail diesel engine.

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