JP5505139B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine that controls fuel injection by adjusting the opening / closing timing of an injector in the internal combustion engine.

In the diesel engine, pilot injection for injecting fuel before main fuel injection and multi-injection for performing post injection for injecting fuel after main fuel injection are performed.
Further, as described in Patent Document 1, even in a gasoline engine, in order to realize good combustion, multi-injection that injects fuel to be used for combustion in a single combustion stroke in a plurality of times is performed. What to do is proposed.

JP 2007-154853 A

  By the way, the control device for an internal combustion engine sets the injection start timing in accordance with the rotation angle of the crankshaft or the rotation angle of the camshaft in order to control the fuel injection timing. When the injection start time comes, the injector is opened to inject fuel. However, since the length of the injection period for injecting the required amount of fuel changes according to the pressure of the fuel supplied to the injector, the injection end timing depends on the amount of fuel to be injected and the time at that time Varies depending on the fuel pressure.

  For example, when the pressure of the fuel supplied to the injector is low, the amount of fuel injected per unit time decreases, so that the fuel is injected over a longer period in order to inject an equal amount of fuel. It will be necessary.

  Therefore, as shown in FIGS. 13 and 14, even when the injector is opened at times T1, T2, and T3 and fuel is injected in three times in order to inject an equal amount of fuel, as shown in FIG. When the fuel pressure is low as shown in FIG. 14, the injection period of each injection becomes longer than when the fuel pressure is high as shown in FIG. As a result, there is a possibility that the injection start timing of the subsequent injection arrives and the injection periods overlap before the end of the previous injection as shown by the portion surrounded by the broken line in FIG. Further, if the injection period becomes longer, as shown on the right side of FIG. 14, the injection period may exceed the time X indicating the end of the effective injection period set based on the closing timing and ignition timing of the intake valve. There is.

  In addition, since the amount of change in the rotation angle per unit time increases as the engine speed increases, the injection start timing of each injection comes earlier, and the time interval of each injection becomes shorter. Therefore, when the engine rotation speed is high, the injection period of each injection is relatively long with respect to the interval of each injection compared to when the engine rotation speed is low. Therefore, even when the engine speed is high, the injection start timing of the subsequent injection comes before the end of the previous injection, and the injection periods of the respective injections overlap, as in the case where the fuel pressure is low. There is a risk that. Note that the higher the engine speed, the earlier the end of the effective injection period comes. Therefore, when the engine speed is high, the injection period may exceed the effective injection period.

  The present invention has been made in view of the above circumstances, and its purpose is to adjust the opening / closing timing of the injector while suppressing the influence on the fuel consumption and drivability, and to determine the injection period of each injection in the multi-injection. An object of the present invention is to provide a control device for an internal combustion engine that can suppress overlapping and a series of injections from continuing until the effective injection period.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, a control device for an internal combustion engine is a control device for an internal combustion engine that performs multi-injection for injecting fuel to be used for combustion in a single combustion stroke in a plurality of times. When it is predicted that a series of injections to be performed cannot be appropriately executed, priority is given to keeping the number of injections in the series of injections over keeping the injection timing in each injection constituting the series of injections. In addition, the gist is to adjust the opening / closing timing of the injector by giving priority to protecting the fuel injection amount by the series of injections rather than protecting the number of injections in the series of injections.

  When it is predicted that a series of injections divided into multiple times cannot be performed properly, the opening / closing timing of the injectors related to the series of injections is adjusted so that the series of injections can be executed properly It is desirable to do.

  However, since the fuel injection amount has a very direct effect on the magnitude of torque obtained through combustion, if the injector opening / closing timing is adjusted in such a manner that the fuel injection amount changes, the series of injections The torque obtained through this will change.

On the other hand, changes in the number of fuel injections and injection timing have a smaller effect on the magnitude of torque obtained through combustion than changes in the injection amount.
Therefore, in adjusting the opening / closing timing of the injector for a series of injections, priority is given to keeping the fuel injection amount, and the injector opening / closing time can be changed by changing the number of injections and the injection timing without changing the injection amount as much as possible. It is desirable to adjust the timing.

  In addition, when the fuel is injected in a plurality of times, the formation of an air-fuel mixture suitable for combustion is promoted by the fuel being injected in a plurality of times. That is, by injecting the fuel into a plurality of times, the same torque is generated with less fuel, and the fuel consumption is reduced. Therefore, when the number of injections is reduced without changing the fuel injection amount for a series of injections, the effect obtained by injecting the fuel into a plurality of times is reduced, so the torque obtained by combustion is reduced. Will decrease.

On the other hand, the change in the injection timing has less influence on the magnitude of the torque obtained through the combustion than the change in the number of injections.
Therefore, in adjusting the opening and closing timing of the injector for a series of injections, prioritizing to observe the number of injections, followed by maintaining the number of injections, without changing the injection amount and the number of injections as much as possible, First, it is desirable to adjust the opening / closing timing of the injector by changing the injection timing.

On the other hand, the above configuration gives priority to protecting the number of injections in a series of injections rather than protecting the injection timing in each injection constituting the series of injections, and protects the number of injections in a series of injections. The opening / closing timing of the injector is adjusted by giving priority to protecting the fuel injection amount by a series of injections.

Therefore, according to the above configuration , a series of injections are appropriately executed while suppressing that the injection periods of the respective injections in the multi-injection overlap and that a series of injections continue until the effective injection period. When adjusting the opening / closing timing of the injector, it is possible to change the fuel injection amount, the number of injections, and the injection timing so as not to change as much as possible the one that has a large effect on the magnitude of torque caused by combustion. The timing will be adjusted.

Therefore, according to the above configuration , the opening / closing timing of the injector is adjusted while suppressing the fluctuation of torque as much as possible to suppress the influence on the fuel consumption and drivability, and the injection periods of the respective injections in the multi-injection overlap. And a series of injections can be prevented from continuing until after the effective injection period.

Further, in the above configuration, when it is predicted that the series of injections cannot be appropriately performed, first, the injection timing in each injection constituting the series of injections may be adjusted and the injection timing adjusted. In addition, when it is predicted that the series of injections cannot be appropriately performed, two or more injections in the series of injections are combined into one to reduce the number of injections. When it is predicted that the fuel injection cannot be properly performed, a configuration in which the fuel injection amount by the series of injections is reduced may be employed.

By employing the configuration as described above, it causes priority to defend the injection number than to protect timing morphism injection, by priority to protect the injection quantity than to protect injection number adjusting the opening and closing timing of the injector The configuration to be realized can be realized.

In the above structure, when the injection period of each injection constituting the series of injection overlap is estimated, it may predict that it is not possible to properly execute the series of injection on the basis thereof .

  If the injection start timing of each injection constituting the series of injections has already been set, the injection start time of each injection constituting the series of injections is determined based on the engine speed at that time and the pressure of the fuel supplied to the injector. The injection end time can be estimated. That is, it is possible to estimate the injection period of each injection based on the engine rotation speed and the fuel pressure, and to estimate whether or not the injection periods of each injection overlap.

Therefore, as a specific method for predicting that a series of injections cannot be appropriately performed, it is estimated whether or not the injection periods of the respective injections overlap, and the injection periods of the respective injections are determined as described above. What is necessary is just to employ | adopt the structure which estimates that a series of injection cannot be performed appropriately based on it when it is estimated that it overlaps.

Further, in the above-described configuration, an injection end timing of a previous injection executed first among a plurality of injections related to the series of injections, and an injection start timing of a subsequent injection executed after the previous injection In the meantime, when the interval set based on the length of the period from when the process of instructing the injector to close the valve until the injector is actually fully closed is not secured, the series of it is possible to adopt a configuration of estimating the injection period of each injection that constitutes the injection overlap.

  There is a time lag due to a delay in the operation of the injector, that is, a so-called valve closing delay between the time when the injector is instructed to close the valve and the time when the injector is actually fully closed. In addition, a valve opening delay, which is a time lag due to a similar operation delay, occurs after the process of instructing the valve opening to the injector until the injector is actually fully opened.

  Such characteristics of valve opening delay and valve closing delay can be grasped by conducting an experiment or the like in advance. Therefore, even when valve opening delay or valve closing delay occurs, the fuel injection amount estimated based on the timing when the processing for instructing the injector to open / close is made based on the characteristics obtained through experiments or the like. By correcting the valve opening delay and the valve closing delay, the fuel injection amount can be estimated relatively easily.

  However, the process in which the subsequent injection is started and the injector is instructed to open the valve during the valve closing delay period after the injector is instructed to close the valve until the injector is actually fully closed. In the case where the injection is performed, the injector is opened again before it is fully closed, and the injection period of the previous injection and the subsequent injection overlap. In this case, correction of the injection amount corresponding to the valve closing delay of the previous injection and correction of the injection amount corresponding to the valve opening delay of the subsequent injection can be easily performed based on characteristics obtained through experiments or the like. You will not be able to do it.

Therefore, in estimating that the injection period of the previous injection and the subsequent injection overlap, an interval set based on the length of the period corresponding to the valve closing delay is set between the previous injection and the subsequent injection. It is desirable to adopt a configuration that estimates that the injection period of the previous injection and the subsequent injection overlap when it is not secured.

  By adopting such a configuration, it is possible to accurately estimate that the previous injection and the subsequent injection overlap based on the fact that the interval is not secured, and to adjust the opening / closing timing of the injector. Therefore, it becomes possible to prevent the injector from being reopened before it is fully closed, and as a result, it becomes impossible to estimate the injection amount based on characteristics obtained through experiments or the like. Thus, the fuel injection amount can be estimated more accurately.

Further, in the above configuration , an injection period of a previous injection that is executed first among a plurality of injections related to the series of injections may overlap an injection period of a subsequent injection that is executed next to the previous injection. When estimated, the injection start timing in the subsequent injection may be retarded so as to ensure the interval between the injection end timing in the previous injection and the injection start timing of the subsequent injection. .

When the injection period of each injection constituting a series of injections is estimated based on the engine speed and the fuel pressure, the first injection executed first, followed by the next injection executed next When it is estimated that the injection periods overlap with each other, the injection start timing in the subsequent injection is delayed so as to secure an interval between the injection end timing in the previous injection and the injection start timing in the subsequent injection. It is desirable.

By adopting such a configuration, it is possible to eliminate overlapping injection periods without changing the injection amount and the number of injections.
Further, in the above configuration , when it is estimated that the series of injections continues after the effective injection period, which is a period for effectively injecting fuel to be used for combustion, the series of injections is based on the estimation. It is preferable to predict that cannot be performed properly.

  In an internal combustion engine that injects fuel from an injector provided in an intake port toward a combustion chamber, it is necessary to inject fuel until the intake valve is closed. Further, in an internal combustion engine that injects fuel from an injector provided in a cylinder, fuel can be injected even after the intake valve is closed, but it is necessary to inject fuel before ignition is performed. is there.

That is, in order to effectively inject fuel to be used for combustion, it is necessary to inject fuel during a predetermined period. Therefore, as a specific method for predicting that a series of injections cannot be performed properly, a series of injections until after the effective injection period, which is a period for effectively injecting fuel for combustion, estimating whether or not to continue, it predicts that when a series of injection is estimated to be continued to the effective injection period later, can not be properly executed a series of injection on the basis of the fact configuration Should be adopted.

  In an internal combustion engine that injects fuel from an injector provided in the intake port toward the combustion chamber, it is necessary to inject fuel until the intake valve closes as described above. Therefore, in the control device for an internal combustion engine that controls the internal combustion engine that injects fuel from the injector provided in the intake port toward the combustion chamber, the effective injection period is determined based on the closing timing of the intake valve. The

  Further, in an internal combustion engine that injects fuel from an injector provided in a cylinder, it is necessary to inject fuel before ignition is performed, as described above. Therefore, in the control device for an internal combustion engine that controls the internal combustion engine that injects fuel from the injector provided in the cylinder, the effective injection period is determined based on the ignition timing.

Further, in the above configuration , when it is estimated that the series of injections continues until the effective injection period or later, the injection end timing of the previous injection executed first among the plurality of injections related to the series of injections Between the injection start timing of the subsequent injection executed after the previous injection and the process of instructing the injector to close the valve until the injector is actually fully closed. It is preferable to advance the injection timing of the subsequent injection within a range in which an interval set based on the length can be secured, and advance the injection end timing of the series of injections.

When estimating the injection period of each injection that constitute the series of injection based on the pressure of the engine speed and the fuel, a series of injection, when it is estimated to continue until effective injection time later, one series A period corresponding to the valve closing delay between the injection end timing of the previous injection executed immediately before and the injection start timing of the subsequent injection among the plurality of injections related to the injection It is preferable to advance the injection end timing of a series of injections by advancing within a range in which an interval set based on the length of the injection can be secured.

  By adopting such a configuration, it is possible to advance the injection end timing related to a series of injections without changing the fuel injection amount and the number of injections. Therefore, it becomes possible to keep the injection period within the effective injection period without changing the injection amount and the number of injections.

Further, in the above configuration , the injection timing of the injection in order from the injection executed later among the plurality of injections related to the series of injections, and the injection end timing of the previous injection executed before the injection, It is estimated that the series of injections ends within the effective injection period by advancing the angle within a range in which the interval can be ensured between the injection start timings of the subsequent injections and advancing the injection timings. When this happens, it is preferable to end the adjustment of the opening / closing timing of the injector at that time.

  By adopting such a configuration, it is possible to suppress changes in the injection timing, and while performing a series of injections as close as possible to the initially set injection start timing, the series of injections continues until the effective injection period and beyond. Can be suppressed.

Further, in the above configuration, the injection timing in the subsequent injection is retarded so as to ensure the interval between the injection end timing in the previous injection and the injection start timing in the subsequent injection in the series of injections. After securing the interval between the injections in the series of injections, the injection timing of the subsequent injection is set between the injection end timing of the previous injection and the injection start timing of the subsequent injection. It is preferable to advance the angle within a range that can be ensured and advance the injection end timing for the series of injections.

As well as eliminate the overlap of the injection period of each injector according to the series of injection, in suppressing that injection period according to a series of injection will continue until the effective injection time and later, is estimated that the overlapping jetting period By delaying the injection timing of the subsequent injections of the pair of injections, the interval between the injections is secured, and then the injection timing of the subsequent injections is advanced within a range in which the same interval can be secured. It is desirable to adopt a configuration in which the angle is made to advance and the injection end timing related to the series of injections is advanced.

  By adopting such a configuration, it is possible to eliminate the overlap of the injection periods of the injections related to the series of injections and to suppress the series of injections from continuing until the effective injection period.

Incidentally, in order from the injection to be executed after ones of the plurality of injection according to the injection of a series, by adopting the above configuration the injection timing to those provided with the structure to advance further effectively suppress changes of the injection timing Will be able to. Therefore, while performing a series of injections in a state as close as possible to the initially set injection start timing, it is possible to eliminate overlapping injection periods of the series of injections and to continue the series of injections after the effective injection period. It becomes possible to suppress this.

Further, in the above configuration , when it is estimated that the series of injections continues after the effective injection period even after adjusting the injection timing, the interval between the previous injection and the subsequent injection is set. By advancing the injection timing of the subsequent injection so as to be eliminated, the previous injection and the subsequent injection are combined into one injection to reduce the number of injections, and the injection timing of the injection executed after the subsequent injection It is preferable to advance the whole.

Further, in the above configuration , the injection timing of the subsequent injection is advanced so as to eliminate the interval between the previous injection and the subsequent injection in order from the injection executed later among the plurality of injections related to the series of injections. It is estimated that the series of injections is completed within the effective injection period by reducing the number of injections by making the angle and advancing the entire injection timing of the injections executed after the subsequent injection. In such a case, a configuration may be adopted in which adjustment of the opening / closing timing of the injector is terminated at that time.

If it is estimated that a series of injections will continue until the effective injection period after adjusting the injection timing, the injection timing of the subsequent injection is eliminated so as to eliminate the interval between the previous injection and the subsequent injection. By advancing, the previous injection and the subsequent injection are combined into one injection to reduce the number of injections, and the entire injection timing of the injection executed after the subsequent injection is advanced. That's fine.

  By adopting such a configuration, it is possible to advance the injection end timing related to a series of injections without changing the fuel injection amount. Therefore, it is possible to keep the injection period within the effective injection period without changing at least the injection amount.

In the case of adopting the structure to reduce in this way the injection number, in order from the injection to be executed after ones of the plurality of injection according to the injection of a series, by advancing the injection timing so as to eliminate the interval injection to reduce the number, by reducing the number of injections, when a series of injection ends within the effective injection period it came to be estimated, further configured to close the adjustment of the opening and closing timing of the injector at that time It is desirable to adopt.

  By adopting such a configuration, it is possible to suppress the number of injections and the change in the injection timing associated with the reduction in the number of injections, and while performing a series of injections in a state as close as possible to the initially set injection mode, It becomes possible to suppress that the injection continues until after the effective injection period.

Further, in the above configuration , when it is estimated that the series of injections continues even after the effective injection period even if the number of injections is reduced, the injection end timing of the series of injections is set to the effective injection period. A configuration may be employed in which the injection period for the series of injections is shortened so as to coincide with the end, and the fuel injection amount for the series of injections is reduced .

When also performing the reduction of injection times it should be noted the sequence of injection is continued until the effective injection time period after the is estimated a series to match the injection end timing of a series of injection at the end of the effective injection time What is necessary is just to shorten the injection period concerning this injection and to reduce the injection quantity of the fuel concerning a series of injections.

By adopting such a configuration, it is possible to avoid that fuel is injected after the effective injection period, although it does not contribute to combustion effectively, and wasteful consumption of fuel can be suppressed.
In the above configuration, the length of the interval may be corrected according to the pressure of the fuel supplied to the injector.

  In the injector that opens and closes the injection port by displacing the needle valve by controlling the balance of the pressure of the fuel acting on the needle valve that opens and closes the injection port of the injector, the pressure of the fuel supplied to the injector is The lower the value, the slower the response of the needle valve, and the more likely the injector operation delay occurs.

Therefore, it is desirable to correct the length of the interval according to the pressure of the fuel supplied to the injector as in the above configuration .
If such a configuration is adopted, the length of the interval can be set more accurately in a manner in accordance with the state of the operation delay of the needle valve that changes according to the fuel pressure.

Further, in the above configuration, the injector is opened using the electric charge charged in the driving circuit, and the length of the interval is set based on the time required for charging the driving circuit. You may employ | adopt the structure to do .

In an internal combustion engine that opens the injector by using the electric charge charged in the drive circuit, it is appropriate that the electric charge is stable in the period from the previous injection until the electric charge is charged in the drive circuit. A later injection cannot be performed. Therefore, in the internal combustion engine for opening the injector by using the charges charged in the driving circuit, it is desirable to set the length of the interval based on the time required to charge the driving dynamic circuit.

  By adopting such a configuration, by securing an interval set in consideration of the length of time required for charging, the previous injection is completed, and after the charging to the drive circuit is completed, the subsequent injection is performed. As a result, it is possible to prevent the subsequent injection from being performed in a state where the charging to the drive circuit is not completed. As a result, it is possible to prevent the unstable injection from being executed in a state where the charging to the drive circuit is not completed.

In the above configuration, the length of the interval may be corrected based on a voltage of a battery that supplies power to the drive circuit.
The higher the battery voltage, the shorter the time required for charging the drive circuit. Therefore, it is desirable to correct the length of the interval based on the voltage of the battery for supplying power to drive the dynamic circuit.

  By adopting such a configuration, it becomes possible to set the length of the interval more accurately in a manner corresponding to the length of the period required for charging the drive circuit that changes according to the voltage of the battery.

In the above configuration, the length of the interval may be corrected based on the temperature of the environment surrounding the drive circuit and the battery that supplies power to the drive circuit.

The lower the temperature of the environment surrounding the drive circuit and the battery, the longer it takes to charge the drive circuit. Therefore, it is desirable to correct the length of the interval based on the temperature of the environment surrounding the drive dynamic circuit and battery.

  By adopting such a configuration, the length of the interval can be set more accurately in a manner in accordance with the length of the period necessary for charging the drive circuit that changes according to the temperature of the environment surrounding the drive circuit and the battery. It becomes like this.

In the above-described configuration , the injection start timing of the injection executed first among the plurality of injections constituting the series of injections corresponds to the processing time required for the control device to adjust the opening / closing timing of the injector. It may be configured to be set so as to arrive after a lapse period.

Even if adjusting the opening and closing timing of Lee Njekuta, the injection start timing of the earliest injection to be performed earliest, when the processing for adjusting the opening and closing timing of the injector is set to a point before the ends Cannot accurately control the opening and closing of the injector.

In contrast, by employing the above Ki構 formed, since at least the injection start timing of the earliest injection process according to the adjustment of the opening and closing timing of the injector from when completed so arrives, the time was adjusted opening Based on this, it is possible to accurately control the opening and closing of the injector.

The block diagram which shows the relationship between the electronic control apparatus concerning one Embodiment of this invention, the injector which is the control object of the same electronic control apparatus, and an injector drive circuit. The flowchart which shows the first half part of the flow of a process of the opening-and-closing timing adjustment routine concerning the embodiment. The flowchart which shows the latter half part of the flow of a process of the opening-and-closing timing adjustment routine concerning the embodiment. Explanatory drawing which shows the relationship between the valve opening delay and valve closing delay of an injector, and fuel injection quantity. Explanatory drawing which shows the relationship between the valve closing delay of an injector, and the length of an interval. Explanatory drawing which shows the relationship between the injection period of 1st injection, 2nd injection, and 3rd injection estimated through the opening-and-closing timing adjustment routine. Explanatory drawing which shows the state which retarded the injection timing of 2nd injection through the opening / closing timing adjustment routine. Explanatory drawing which shows the state which advanced the injection timing of 3rd injection through the opening-and-closing timing adjustment routine. Explanatory drawing which shows the state which advanced all the injection timings through the opening-and-closing timing adjustment routine. Explanatory drawing which shows the state which combined the 3rd injection with the 2nd injection through the opening-and-closing timing adjustment routine, and reduced the frequency | count of injection. Explanatory drawing which shows the state which combined the 2nd injection with the 1st injection through the opening-and-closing timing adjustment routine, and reduced the frequency | count of injection. Explanatory drawing which shows the state which shortened the injection period through the opening-and-closing timing adjustment routine, and decreased the amount of fuel injection. Explanatory drawing which shows the relationship of the injection period of each injection in multi injection. Explanatory drawing which shows the relationship of the injection period of each injection when the pressure of the fuel supplied to an injector is low.

Hereinafter, an embodiment in which an internal combustion engine control device according to the present invention is embodied as an electronic control device for controlling an internal combustion engine mounted on a vehicle will be described with reference to FIGS.
FIG. 1 is a block diagram showing the relationship between an electronic control device 100 according to the present embodiment, an injector drive circuit 10 and an injector 20 that are controlled by the electronic control device 100.

  As shown in FIG. 1, an injector drive circuit 10 is connected to the electronic control device 100. A plurality of injectors 20 provided for each cylinder of the internal combustion engine are connected to the injector drive circuit 10.

  The electronic control unit 100 includes a central processing unit (CPU) that executes various arithmetic processes for controlling the internal combustion engine, an arithmetic program and an arithmetic map, a read-only memory (ROM) in which various data are stored, an arithmetic result, and the like. Is provided with a random access memory (RAM) or the like for temporarily storing.

  The injector drive circuit 10 accumulates electric charge with electric power supplied from a battery (not shown), and opens each injector 20 based on a command output from the electronic control unit 100 using the accumulated electric charge.

  The injector 20 is configured such that when the electric charge is supplied from the injector driving circuit 10, the needle valve that opens and closes the injection port is driven to the valve opening side, and the electric charge is supplied from the injector driving circuit 10. Sometimes the valve is opened to inject fuel.

The following various sensors are connected to the electronic control device 100.
The air flow meter 31 detects the temperature Ta of the air introduced into the internal combustion engine and the intake air amount GA which is the amount thereof. The crank position sensor 32 detects a rotation angle of a crankshaft that is an output shaft of the internal combustion engine. Then, the electronic control unit 100 calculates an engine rotation speed NE indicating the rotation speed of the crankshaft per unit time based on the detected rotation angle of the crankshaft. The cam position sensor 33 detects the rotation angle of the camshaft of the internal combustion engine. The water temperature sensor 34 detects the engine cooling water temperature THW which is the temperature of the engine cooling water. The voltage sensor 35 detects the voltage V of the battery that supplies power to the injector drive circuit. The fuel pressure sensor 36 detects a fuel pressure Pf that is the pressure of the fuel supplied to the injector 20.

  The electronic control device 100 reads the effect signals from the various sensors 31 to 36 and the like, and outputs commands for opening and closing the injectors 20 to the injector drive circuit 10.

  In executing the opening / closing control of the injector 20, the electronic control unit 100 grasps the displacement of the piston in each cylinder of the internal combustion engine and the opening / closing timing of the intake valve and the exhaust valve based on the rotation angles of the crankshaft and the camshaft. And in order to implement | achieve favorable combustion, the multi-injection which injects the fuel provided for combustion in one combustion stroke in multiple times is performed. In order to execute the multi-injection, the electronic control unit 100 determines the injection start timing of each injection constituting a series of injections divided into a plurality of times based on the current engine speed NE, the intake air amount GA, and the like. Set each. The injection start timing set at this time is set in correspondence with the rotation angle of the crankshaft.

  Then, the electronic control unit 100 executes a process for instructing the injector drive circuit 10 to open the valve so as to open the injector 20 when the injection start time arrives, and injects the fuel into a plurality of times.

  By the way, the length of the injection period for injecting the required amount of fuel, that is, the length of the valve opening period of the injector 20 varies depending on the pressure of the fuel supplied to the injector 20, The injection end timing of each of the injections constituting the injection changes in accordance with the amount of fuel injected at that time and the fuel pressure Pf at that time.

Therefore, when the fuel pressure Pf is low, the amount of fuel injected from the injector 20 per unit time decreases, and it is necessary to inject fuel over a longer period.
As a result, when the fuel pressure Pf is low, the injection period of each injection in a series of injections executed in a plurality of times is longer than when the fuel pressure Pf is high. As a result, among the series of injections executed in a plurality of times, before the previously executed injection is finished, the injection start time of the injection executed after the injection has arrived, There is a risk that the injection periods will overlap.

Further, if the injection period becomes long, a series of injections may continue beyond the effective injection period determined based on the closing timing and ignition timing of the intake valve.
When the injector 20 is provided in the intake port and fuel is injected from the injector 20 provided in the intake port toward the combustion chamber, it is necessary to inject the fuel until the intake valve is closed. There is. Therefore, when fuel is injected from the injector 20 provided in the intake port toward the combustion chamber, the effective injection period is determined based on the closing timing of the intake valve. On the other hand, when the injector 20 is provided in the cylinder and fuel is injected from the injector 20 provided in the cylinder, the fuel can be injected even after the intake valve is closed. In order to effectively contribute to combustion, it is necessary to inject fuel before ignition is performed. Therefore, when fuel is injected from the injector 20 provided in the cylinder, the effective injection period is determined based on the ignition timing.

  Further, as the engine speed NE increases, the injection start timing of each injection constituting a series of injections comes earlier, and the time interval between the injections becomes shorter. Therefore, when the engine rotational speed NE is high, the injection period of each injection is relatively long with respect to the interval of each injection as compared to when the engine rotational speed NE is low.

  Therefore, even when the engine speed NE is high, as in the case where the fuel pressure Pf is low, the injection start timing of the subsequent injection arrives before the previous injection ends, and the injection periods of the respective injections overlap. There is a risk of becoming. Note that the higher the engine speed NE, the earlier the end of the effective injection period comes. Therefore, when the engine speed NE is high, a series of injections may continue beyond the effective injection period. There is also.

  Therefore, in the electronic control apparatus 100 according to the present embodiment, it is predicted that a series of injections cannot be performed properly after setting the injection start timing of each injection constituting a series of injections performed in multiple steps. When this is done, the opening / closing timing of the injector 20 for a series of injections is adjusted.

Hereinafter, an opening / closing timing adjustment routine for adjusting the opening / closing timing of the injector 20 will be described with reference to FIGS.
2 and 3 are flowcharts showing a flow of a series of processes related to the opening / closing timing adjustment routine. The opening / closing timing adjustment routine is repeatedly executed by the electronic control device 100 at a predetermined control cycle.

  When this opening / closing timing adjustment routine is started, as shown in FIG. 2, the electronic control unit 100 first estimates the injection period of each injection constituting a series of injections performed in a plurality of times in step S100.

  Specifically, the injector 20 in each injection estimated based on the injection start timing of each injection previously set through control different from the opening / closing timing adjustment routine, the current engine speed NE and the fuel pressure Pf. The injection end timing of each injection is estimated based on the valve opening time. By estimating the injection end timing of each injection in this way, the injection period of each injection is estimated.

When the injection period is estimated in this way, the process proceeds to step S200, and the electronic control unit 100 determines whether or not the interval INT and the processing margin M are secured.
Here, the minimum opening interval INT for suppressing the overlap of the injection periods in each injection is ensured between the injections, and this opening / closing timing adjustment routine is executed until the injection to be executed first. It is determined whether a processing margin M for securing a processing time necessary for completion is secured.

  Specifically, in order to determine whether or not the processing margin M can be secured, the length of the period from the current time to the injection start timing of the first execution is set as the processing margin M. It is determined whether or not it is longer than the period. Then, if the length of the period from the current time to the injection start timing of the first execution is longer than the processing margin M, it is determined that the processing margin M is secured.

  Note that the length of the period set as the processing margin M is set based on the maximum value of the processing time required to complete the opening / closing timing adjustment routine. That is, if the processing margin M is ensured, the opening / closing timing adjustment routine is necessarily completed by the injection start timing of the first-executed injection.

  Further, in step S200, by comparing the injection start timing and the injection end timing of each of the injections constituting the series of injections to be executed from now, the injection end timing of the previous injection to be executed first and the previous injection Subsequently, it is determined whether or not the interval INT is secured between the injection start timing of the next injection to be executed next.

  Specifically, when the length of the period existing between the injection end timing of the previous injection and the injection start timing of the subsequent injection is shorter than the interval INT, and in addition to this, the injection start timing of the subsequent injection Is determined before the injection end timing of the previous injection, it is determined that the interval INT is not secured.

  That is, here, it is determined that the interval INT is secured when the length of the period existing between the injection end timing of the previous injection and the injection start timing of the subsequent injection is equal to or greater than the interval INT. The

  Note that the length of the period set as the interval INT is set based on the length of the period from when the process of instructing the valve closing to the injector 20 to when the injector 20 is actually fully closed. Yes.

  After the process of instructing the injector 20 to close the valve, until the injector 20 is actually fully closed, the operation of the injector 20 is delayed as shown by the one-dot chain line in FIGS. Due to the time lag, a so-called valve closing delay occurs. In addition, a delay in valve opening, which is a time lag caused by the same operation delay, occurs after the process of instructing the valve opening to the injector 20 until the injector 20 is actually fully opened.

4 and 5, the opening / closing command to the injector 20 is indicated by a solid line, and the actual opening / closing operation of the injector 20 is indicated by a one-dot chain line.
Such characteristics of valve opening delay and valve closing delay can be grasped by conducting an experiment or the like in advance. Therefore, even if valve opening delay or valve closing delay occurs, the fuel injection amount estimated based on the timing when the injector 20 is instructed to open and close is based on characteristics obtained through experiments or the like. By correcting the valve opening delay and the valve closing delay, the fuel injection amount can be estimated relatively easily.

  For example, as shown by the solid line on the left side of FIG. 4, when processing for instructing the injector 20 to open is performed at time t <b> 1 and processing for instructing the injector 20 to close the valve is performed at time t <b> 3, As shown, the injector 20 gradually opens from time t1, and is fully opened at time t2. Then, the injector 20 gradually closes from time t3 and becomes fully closed at time t5.

  Since the fuel injection amount at this time can be estimated based on the area of the hatched portion in FIG. 4, it corresponds to the characteristics of the valve opening delay and the valve closing delay, that is, the valve opening delay and the valve closing delay. If the change mode of the valve opening amount of the injector 20 during the period is known, the fuel injection amount can be calculated by integrating the valve opening amount.

  In correcting the valve opening delay and the valve closing delay, the injection amount calculated in consideration of the valve opening delay and the valve closing delay, and the injector without taking the valve opening delay and the valve closing delay into consideration. The difference from the fuel injection amount estimated based on the time when the process for instructing opening / closing to 20 is performed may be learned as the amount of deviation of the injection amount due to the valve opening delay and the valve closing delay.

  If the estimated injection amount is corrected without considering the valve opening delay and the valve closing delay based on the learned deviation amount, the actual valve opening amount of the injector 20 does not have to be integrated every time. The fuel injection amount can be estimated relatively easily.

  However, as indicated by the solid line on the right side of FIG. 4, during the valve closing delay period (between times t <b> 3 and t <b> 5), when the subsequent injection is started and processing for instructing the injector 20 to open the valve is performed The valve is opened again before the injector 20 is fully closed, and the injection period of the previous injection and the subsequent injection overlap (time t4 in FIG. 4).

  In this case, since the injector 20 opens again from time t4 as shown by the one-dot chain line in FIG. 4, the injection amount can be accurately estimated based on the previously learned deviation amount. It becomes impossible.

  Therefore, in this embodiment, as shown in FIG. 5, the length of the interval INT is set in accordance with the length of the valve closing delay period, and the interval between the previous injection and the subsequent injection is set. By ensuring this interval INT, the actual valve opening period of the injector 20, that is, the injection period is prevented from overlapping.

  If it is not determined in step S200 that the interval INT and the processing margin M have been secured (step S200: NO), based on this, it is predicted that a series of injections cannot be performed appropriately, Proceed to S210.

In step S210, the electronic control unit 100 retards the injection timing so that the interval INT and the processing margin M can be secured.
In the opening / closing timing adjustment routine, among a plurality of injections related to a series of injections, the injection timing is retarded as necessary in order from the previously executed injection. The process of step S200 is repeated each time the injection timing of the target injection is retarded. For example, when the first executed injection cannot secure the processing margin M or when the interval INT cannot be ensured with the injection executed before the injection, the interval INT and the processing margin M The injection timing is retarded until the time at which the minimum fuel consumption can be ensured. When the injection timing of the injection is retarded, the process returns to step S200, and it is determined again whether the interval INT and the processing margin M are secured.

  That is, step S200 and step S210 are repeated until all of the injections constituting the series of injections to be executed can secure the interval INT and the processing margin M, thereby ensuring the interval INT and the processing margin M. In this manner, the injection timing is retarded in order from the previously executed injection.

  If it is determined in step S200 that the interval INT and the processing margin M have been secured (step S200: YES), the process proceeds to step S300, and the electronic control unit 100 determines the injection end timing of a series of injections. It is determined whether or not the effective injection period has been exceeded.

  Specifically, among the injections constituting a series of injections, the injection end timing of the last executed injection is compared with the end of the effective injection period, and the injection end timing of the last executed injection is effective. When it is after the end of the injection period, it is determined based on this that the injection end timing of the series of injections exceeds the effective injection period.

  If it is determined in step S300 that the injection end timing of the series of injections does not exceed the effective injection period (step S300: NO), the series of injections ends within the effective injection period based on this. As shown in FIG. 3, the electronic control unit 100 once terminates the opening / closing timing adjustment routine.

  On the other hand, when it is determined in step S300 that the injection end timing of the series of injections exceeds the effective injection period (step S300: YES), the series of injections cannot be appropriately executed based on this. Is advanced to step S310.

  In step S310, the electronic control unit 100 advances the injection timing of each injection and advances the injection end timing of a series of injections while securing the interval INT and the processing margin M.

  In this opening / closing timing adjustment routine, the injection timing of the injection is changed from the plurality of injections in the series of injections in order from the injection executed later, to the injection of the previous injection executed before the injection. The angle is advanced within a range in which the interval INT can be secured between the injection end timing and the injection start timing of the subsequent injection.

  Then, when the injection timing of the target injection is advanced, the process proceeds to step S320. In addition, when the period between the injection start timing of the target injection and the injection end timing of the previous injection executed before the injection is already equal to the interval INT, the interval INT is secured. However, since the injection timing cannot be advanced any further, the process proceeds directly to step S320.

  Then, in step S320, the electronic control unit 100 determines whether or not the process of step S310 is looped by the number of injections in a series of injections. For example, when the series of injections to be executed from this time is to inject fuel in three times, it is determined whether or not the process of step S310 has been executed three times.

  In step S320, when it is not determined that the process of step S310 is looped by the number of injections in a series of injections (step S320: NO), the process returns to step S300.

  In this opening / closing timing adjustment routine, by repeating the processing of step S310 in this way, the injection timing is advanced within a range in which the interval INT and the processing margin M can be secured in order from the subsequent injection, and a series of injections is performed. Advance the injection end timing. When it is estimated that a series of injections will be completed within the effective injection period by advancing the injection timing through the process of step S310, the opening / closing timing adjustment routine is terminated at that time, and the injector The adjustment of the opening / closing timing of 20 ends. On the other hand, if it is determined in step S320 that the process of step S310 has been looped by the number of injections in a series of injections (step S320: YES), the process proceeds to step S400 shown in FIG.

  That is, an affirmative determination is made in step S320, and the process proceeds to step S400 because the process of step S310 is repeated for the number of injections to advance the injection timing of all injections within a range in which the interval INT and the process margin M can be secured. This is a case where a series of injections does not fall within the effective injection period even if the angle is made.

In step S400, the electronic control unit 100 determines whether or not the injection end timing of a series of injections exceeds the effective injection period as in step S300 described above.
When it is determined in step S400 that the injection end timing of the series of injections does not exceed the effective injection period (step S400: NO), the series of injections ends within the effective injection period based on this. The electronic control unit 100 once terminates the opening / closing timing adjustment routine.

  On the other hand, when it is determined in step S400 that the injection end timing of the series of injections exceeds the effective injection period (step S400: YES), the series of injections cannot be appropriately executed based on this. Is advanced to step S410.

  In step S410, the electronic control unit 100 eliminates the interval INT and advances the injection timing of the subsequent injection, thereby combining the subsequent injection with the previous injection and reducing the number of injections.

  In this opening / closing timing adjustment routine, the injection timings of the injections are determined in order from the injection executed later among the plurality of injections related to the series of injections, and the injection executed before the injection. Is advanced so as to eliminate the interval INT secured between the two and the injection is combined with the previous injection. When the target injection is combined with the previous injection, the process proceeds to step S420.

  In step S420, the electronic control unit 100 determines whether or not the process of step S410 has been looped by a number of times less than the number of injections in a series of injections. For example, when the series of injections to be executed from this time is to inject the fuel in three times, it is determined whether or not the process of step S410 has been executed twice.

  In step S420, when it is not determined that the process of step S410 has looped by one less than the number of injections in a series of injections (step S420: NO), the process returns to step S400.

  That is, in this opening / closing timing adjustment routine, the processing of step S410 is repeated in this manner, so that the injection timing is advanced in order from the subsequent injection and combined with the previous injection, thereby reducing the number of injections. Then, when it is estimated that the series of injections is completed within the effective injection period by reducing the number of injections of the series of injections and advancing the injection end timing through the processing of step S410, At that time, the opening / closing timing adjustment routine is ended, and the adjustment of the opening / closing timing of the injector 20 is ended. On the other hand, when it is determined in step S420 that the process of step S410 has been looped by a number of times less than the number of injections in a series of injections (step S420: YES), the process proceeds to step S500.

  In short, an affirmative determination is made in step S420 and the process proceeds to step S500 because the process in step S410 is repeated one less than the number of injections to combine all the injections to reduce the number of injections to one. This is still the case when a series of injections do not fall within the effective injection period.

  In step S500, the electronic control unit 100 determines whether or not the injection end timing of a series of injections exceeds the effective injection period, as in step S300 and step S400 described above.

  If it is determined in step S500 that the injection end timing of the series of injections does not exceed the effective injection period (step S500: NO), the series of injections ends within the effective injection period based on this. The electronic control unit 100 once terminates the opening / closing timing adjustment routine.

  On the other hand, when it is determined in step S500 that the injection end timing of the series of injections exceeds the effective injection period (step S500: YES), the series of injections cannot be appropriately executed based on this. Is advanced to step S510.

In step S510, the electronic control unit 100 shortens the injection period by the amount exceeding the effective injection period, and reduces the injection amount by a series of injections.
Specifically, the injection period for the series of injections is shortened by advancing only the injection end timing of the series of injections to coincide with the end of the effective injection period, and the fuel injection amount for the series of injections is reduced. Decrease.

When the injection amount is decreased in this way, the electronic control unit 100 once ends this opening / closing timing adjustment routine, and ends the adjustment of the opening / closing timing of the injector 20.
Hereinafter, an operation when the opening / closing timing of the injector 20 is adjusted through the above-described opening / closing timing adjustment routine will be specifically described with reference to FIGS.

  Here, as shown in FIG. 6, the injection start timing of a series of injections is set so as to inject fuel into three parts of the first injection INJ1, the second injection INJ2, and the third injection INJ3 from the present time. The operation of the opening / closing timing adjustment routine will be described by exemplifying the state of being present. Note that “INJX” shown on the left side of FIG. 6 indicates the injection period of the injection INJX executed before the present time.

  When the opening / closing timing adjustment routine is started, the valve opening time of the injector 20 in each injection is estimated based on the current engine speed NE and the fuel pressure Pf. Then, based on the estimated valve opening time of the injector 20 in each injection and the injection start timing in each injection, the injection period of each injection is estimated as shown in FIG. In FIG. 6, “INJX”, “INJ1”, “INJ2”, and “INJ3” indicate the injection periods of the respective injections INJX, INJ1, INJ2, and INJ3, and the left end of these injections is the injection start timing of each injection. The right end portion indicates the injection end timing in each injection.

  When the injection period of each injection is estimated in this way, the injection timing is delayed so that the interval INT and the processing margin M can be secured in order from the previous injection through step S200 and step S210 of the opening / closing timing adjustment routine. .

  As shown in FIG. 6, the injection start timing of the first injection INJ1 that is executed first from the present time is more than the interval INT from the injection end timing of the injection INJX that is executed before the current time, and from the current time The processing margin is more than M. Accordingly, since the interval INT and the processing margin M are secured, the injection timing of the first injection INJ1 is not retarded here.

  On the other hand, the injection start timing of the second injection INJ2 is before the injection end timing of the first injection INJ1, as shown in FIG. Therefore, since the interval INT is not secured, the second injection INJ2 is retarded so that the injection timing can secure the interval INT as shown by the arrow in FIG.

In the third injection INJ3, it is determined whether or not the interval INT is secured based on the injection end timing of the retarded second injection INJ2.
As shown in FIG. 7, the injection start timing of the third injection INJ3 is separated from the injection end timing of the second injection INJ2 by an interval INT or more. Accordingly, since the interval INT and the processing margin M are secured, the injection timing of the third injection INJ3 is not retarded at this time.

  As shown in FIG. 7, the injection end timing of the third injection INJ3 after delaying the injection timing of each injection so as to ensure the interval INT and the processing margin M as described above is effective injection. It is set to a period after the end of the period. Therefore, in this state, a series of injections to be executed will continue until the effective injection period.

  Therefore, the injection timing is advanced in a range in which the interval INT and the processing margin M can be secured in order from the subsequent injection through the processes of steps S300 to S320. It should be noted that a series of injections are estimated to end within the effective injection period when the injection timing of each injection is delayed so that the interval INT and the processing margin M can be secured through steps S200 and S210. In such a case, the opening / closing timing adjustment routine ends at that time. In addition, when the opening / closing timing adjustment routine is started, the processing margin M and the interval INT have already been secured, and if a series of injections are finished within the effective injection period, any injection timing is set. The opening / closing timing adjustment routine is terminated without being delayed.

  Through the processes in steps S300 to S320, first, an interval INT is secured between the injection timing of the third injection INJ3 that is executed last as shown by the arrow in FIG. 8 and the injection end timing of the second injection INJ2. It is advanced as far as possible.

  As shown in FIG. 8, even if the injection timing of the third injection INJ3 is advanced, the injection end timing of the third injection INJ3 is still set to a timing after the end of the effective injection period. An advance of the injection timing of the injection INJ2 is attempted.

  However, the interval between the second injection INJ2 and the first injection INJ1 is already set to a length equal to the interval INT, and the injection timing of the second injection INJ2 is further advanced while ensuring the interval INT. I can't. Therefore, the injection timing of the second injection INJ2 is not advanced here.

  The first injection INJ1 is separated from the injection INJX executed before the current time by an interval INT or more, and further from the current time by a processing margin M or more. Therefore, next, the first injection INJ1 is advanced within a range in which the interval INT and the processing margin M can be secured as indicated by arrows in FIG. At this time, the second injection INJ2 and the third injection INJ3 as shown by the arrows in FIG. 9 are maintained so that the interval between the injections INJ1, INJ2, and INJ3 is maintained at an interval equal to the interval INT. The injection timing is advanced at the same time.

  Even after the injection timing of each injection is advanced so that the interval INT and the processing margin M can be ensured as described above, the injection end timing of the third injection INJ3 is the effective injection as shown in FIG. It is set to a period after the end of the period. Therefore, in this state, a series of injections to be executed will continue until the effective injection period.

  Therefore, next, the interval INT is eliminated one by one from the subsequent injection through the processing of steps S400 to 420, and the injection end timing of a series of injections is advanced by combining the injections first and reducing the number of injections. . In addition, when it is estimated that a series of injections will be completed within the effective injection period when the injection timing of any of the injections is advanced through the processing of steps S300 to 320, the opening / closing timing adjustment is performed at that time. The routine will be terminated. Further, when a series of injections come within the effective injection period in the process of advancing the injection timing of each injection, the advance of the injection timing is ended at that time, and the opening / closing timing adjustment routine is ended.

  Through the processes of steps S400 to 420, first, the injection timing of the third injection INJ3 to be executed last is advanced so as to eliminate the interval INT, and the third injection INJ3 is combined with the second injection INJ2, and the number of injections Reduced to twice.

  Here, as shown in FIG. 10, even when the third injection INJ3 is combined with the second injection INJ2, the injection end timing of the series of injections is set to the timing after the end of the effective injection period. Therefore, next, as indicated by an arrow in FIG. 11, the injection timing of the second injection INJ2 is advanced so as to eliminate the interval INT, the second injection INJ2 is coupled to the first injection INJ1, and the number of injections is 1. Reduced to times.

  As shown in FIG. 11, even after the injection timing of each injection is advanced and the number of injections is reduced to one, the injection end timing of a series of injections is set to a timing after the end of the effective injection period. Yes. Therefore, in this state, a series of injections to be executed will continue until the effective injection period.

  Therefore, the fuel injection amount is decreased by shortening the injection period by the amount exceeding the effective injection period through the process of step S510, and the injection end timing of a series of injections is advanced. If it is estimated that a series of injections will be completed within the effective injection period when the injection timing is reduced by advancing the injection timing of any injection through the processing of steps S400 to S420, At this point, the opening / closing timing adjustment routine ends.

  As indicated by an arrow in FIG. 12, when the injection end timing of a series of injections is advanced so as to coincide with the end of the effective injection period through the process of step S510, the series of injections falls within the effective injection period. It becomes like this.

According to the embodiment described above, the following effects can be obtained.
(1) When it is predicted that a series of injections performed in a plurality of times cannot be appropriately executed, the injector 20 related to the series of injections can be appropriately executed so that the series of injections can be appropriately executed. It is desirable to adjust the opening and closing time.

  However, since the fuel injection amount has a very direct influence on the magnitude of torque obtained through combustion, when the opening / closing timing of the injector 20 is adjusted in such a manner that the fuel injection amount changes, the series of the fuel injection amount is changed. The torque obtained through injection changes.

On the other hand, changes in the number of fuel injections and injection timing have a smaller effect on the magnitude of torque obtained through combustion than changes in the injection amount.
Therefore, in adjusting the opening / closing timing of the injector 20 for a series of injections, the injector 20 is prioritized to protect the fuel injection amount, and the number of injections and the injection timing are changed without changing the injection amount as much as possible. It is desirable to adjust the opening and closing time of the.

  In addition, when the fuel is injected in a plurality of times, the formation of an air-fuel mixture suitable for combustion is promoted by the fuel being injected in a plurality of times. That is, by injecting the fuel into a plurality of times, the same torque is generated with less fuel, and the fuel consumption is reduced. Therefore, when the number of injections is reduced without changing the fuel injection amount for a series of injections, the effect obtained by injecting the fuel into a plurality of times is reduced, so the torque obtained by combustion is reduced. Will decrease.

On the other hand, the change in the injection timing has less influence on the magnitude of the torque obtained through the combustion than the change in the number of injections.
Therefore, in adjusting the opening / closing timing of the injector 20 related to a series of injections, the priority is given to the number of injections after the fuel injection amount, and the injection amount and the number of injections are changed as much as possible. First, it is desirable to adjust the opening / closing timing of the injector 20 by changing the injection timing.

  On the other hand, in the above-described embodiment, priority is given to protecting the number of injections in a series of injections rather than keeping the injection timing in each injection constituting the series of injections, and the number of injections in a series of injections is set. The opening / closing timing of the injector 20 is adjusted by giving priority to protecting the fuel injection amount by a series of injections rather than protecting.

  Therefore, when adjusting the opening / closing timing of the injector 20, the opening / closing timing is adjusted so as not to change as much as possible the fuel injection amount, the number of injections, and the injection timing, which have a great influence on the magnitude of torque caused by combustion. Will be made.

  Therefore, the opening and closing timing of the injector 20 is adjusted while suppressing the fluctuation of torque as much as possible to suppress the influence on the fuel consumption and drivability, and the injection periods of the multiple injections overlap each other or a series of injections. Can be prevented from continuing until after the effective injection period.

  (2) In the above embodiment, when it is predicted that a series of injections cannot be appropriately executed through the opening / closing timing adjustment routine, first, the injection timings of the respective injections constituting the series of injections are adjusted. I have to. When it is predicted that the series of injections cannot be properly executed even after adjusting the injection timing, two or more injections in the series of injections are combined into one to reduce the number of injections. . If it is predicted that the series of injections cannot be performed properly, the fuel injection amount by the series of injections is reduced.

  Therefore, it is possible to adjust the opening / closing timing of the injector 20 by giving priority to keeping the number of injections over keeping the injection time and giving priority to keeping the injection amount over keeping the number of injections.

  (3) In the above embodiment, when the interval INT set based on the length of the period corresponding to the valve closing delay is not secured between the previous injection and the subsequent injection, It is estimated that the injection periods of the injection and the subsequent injection overlap.

  Therefore, it is possible to accurately estimate that the previous injection and the subsequent injection overlap based on the fact that the interval INT is not secured, and to adjust the opening / closing timing of the injector 20. For this reason, it is possible to prevent the injector 20 from being reopened before it is fully closed, and as a result, the injection amount cannot be estimated based on characteristics obtained through experiments or the like. This can be suppressed and the fuel injection amount can be estimated more accurately.

  (4) When it is estimated through step S200 that the injection period of the previous injection and the subsequent injection that is subsequently executed overlap, the injection end timing in the previous injection is determined through the process of step S210. The injection start timing in the subsequent injection is delayed so as to ensure the interval INT between the injection start timing of the subsequent injection. Therefore, it is possible to eliminate the overlap of the injection periods without changing the injection amount and the number of injections through the processing of step S200 and step S210.

  (5) When it is estimated that a series of injections continue until the effective injection period, first, the injection timing of the injection executed later is set to the injection end timing of the previous injection executed immediately before and after that The injection end timing of a series of injections is advanced by advancing within a range in which the interval INT can be secured between the injection start timings of the injections.

  Therefore, it is possible to advance the injection end timing for a series of injections without changing the fuel injection amount and the number of injections, and without changing the injection amount and the number of injections, the injection period is within the effective injection period. Can be accommodated.

  (6) Further, when the injection timing of each injection is advanced through the processing of steps S300 to 320, the injection timing is advanced in order from the injection executed last to the injection executed first. When it is estimated that this injection will end within the effective injection period, the adjustment of the opening / closing timing of the injector 20 is ended at that time.

  Therefore, it is possible to suppress changes in the injection timing as much as possible, and to suppress a series of injections from continuing until the effective injection period while executing a series of injections in a state as close as possible to the initially set injection start timing. can do.

  (7) After securing the interval INT between the respective injections through the processing of step S200 and step S210, the injection timing of the subsequent injection can be secured within the range in which the interval INT can be secured through the processing of steps S300 to 320. The injection is advanced to advance the injection end timing for a series of injections.

Therefore, it is possible to eliminate the overlap of the injection periods of the injections related to the series of injections and to effectively suppress the series of injections from continuing until the effective injection period.
(8) Further, in the processing of steps S300 to 320, since the injection timing is advanced in order from the injection executed later among the plurality of injections related to the series of injections, the injection timing is necessary. The above changes can be effectively suppressed.

  That is, while performing a series of injections in a state as close as possible to the initially set injection start timing, it is possible to eliminate overlapping injection periods of the series of injections and to continue the series of injections after the effective injection period Can be suppressed.

  (9) Advance the injection timing of the subsequent injection so as to eliminate the interval INT between the previous injection and the subsequent injection through the processing of Steps S400 to 420, thereby making the previous injection and the subsequent injection 1 The number of injections is reduced by combining the two injections, and the entire injection timing of the injection executed after the subsequent injection is advanced.

  Therefore, it is possible to advance the injection end timing related to a series of injections without changing the fuel injection amount. Therefore, it is possible to keep the injection period within the effective injection period without changing at least the injection amount.

  (10) Further, when the number of injections is reduced through the processing of steps S400 to 420, the injection timing is advanced so as to eliminate the interval INT in order from the injection executed later, thereby reducing the number of injections. Is estimated to end within the effective injection period, the adjustment of the opening / closing timing of the injector 20 is ended at that time.

  Therefore, the number of injections can be reduced and the change in the injection timing associated with the reduction in the number of injections can be suppressed as much as possible. It can suppress continuing until after an injection period.

  (11) When it is estimated that a series of injections will continue after the effective injection period even if the number of injections is reduced through the processes in steps S400 to S420, the injection ends in the series of injections through the process in step S510. The injection period is shortened so that the timing coincides with the end of the effective injection period, and the fuel injection amount for a series of injections is reduced.

Therefore, it can be avoided that fuel is injected after the effective injection period although it does not contribute to combustion effectively, and wasteful consumption of fuel can be suppressed.
(12) Even if the injection timing is changed, the number of injections is reduced, and the opening / closing timing of the injector 20 is adjusted by reducing the injection amount, the injection start timing of the earliest injection executed first is When it is set at a time before the end of the process for adjusting the opening / closing timing, the opening / closing control of the injector 20 cannot be performed accurately.

  On the other hand, in the above embodiment, the injection start timing of the injection that is executed first in consideration of the processing time required for the electronic control device 100 to adjust the opening / closing timing through the opening / closing timing adjustment routine. A processing margin M is ensured before.

  Therefore, since the injection start timing of the earliest injection comes after at least the opening / closing timing adjustment routine for adjusting the opening / closing timing of the injector 20 ends, the opening / closing of the injector 20 is accurately opened / closed based on the adjusted opening / closing timing. Control can be performed.

In addition, said embodiment can also be implemented with the following forms which changed this suitably.
In the injector 20 that opens and closes the injection port by displacing the needle valve by controlling the balance of the pressure of the fuel acting on the needle valve that opens and closes the injection port, the pressure of the fuel supplied to the injector 20 The lower the value, the slower the response of the needle valve, and the more likely the operation delay of the injector 20 occurs. Therefore, when adopting an injector that drives the needle valve using such fuel pressure, it is desirable to correct the length of the interval INT according to the fuel pressure Pf.

Specifically, the length of the interval INT may be corrected according to the fuel pressure Pf so that the length of the interval INT is increased as the fuel pressure Pf is lower.
By adopting such a configuration, it becomes possible to set the length of the interval INT more accurately in a manner in accordance with the state of operation delay of the needle valve that changes according to the fuel pressure.

  In the internal combustion engine that opens the injector 20 using the electric charge charged in the injector driving circuit 10 as in the above embodiment, the electric charge is charged in the injector driving circuit 10 after executing the previous injection. Until this is done, the subsequent injection cannot be executed properly in a stable state. Therefore, it is desirable to set the length of the interval INT based on the time required for charging the injector drive circuit 10.

  Specifically, the interval INT is corrected according to the length of time required for charging so that the interval INT is lengthened as the length of time required for charging the injector drive circuit 10 is longer. That's fine.

  If such a configuration is adopted, an interval INT set in consideration of the length of time required for charging is secured, and after the previous injection is completed and charging to the injector drive circuit 10 is completed, It is possible to suppress the subsequent injection from being executed in a state where the charging of the injector drive circuit 10 is not completed. As a result, it is possible to prevent the unstable injection from being executed in a state where the charging of the injector drive circuit 10 is not completed.

  Further, as the voltage V of the battery that supplies power to the injector drive circuit 10 is higher, the charging of the injector drive circuit 10 is completed in a shorter time. Therefore, when setting the length of the interval INT in consideration of the time required for charging, it is desirable to correct the length of the interval INT based on the voltage V of the battery that supplies power to the injector drive circuit 10. .

Specifically, the length of the interval INT may be shortened as the battery voltage V is higher.
By adopting such a configuration, the length of the interval INT can be set more accurately in a manner corresponding to the length of the period required for charging that changes in accordance with the voltage V of the battery.

  Also, the lower the temperature of the environment surrounding the injector drive circuit 10 and the battery, the longer it takes to charge. Therefore, it is desirable to correct the length of the interval INT based on the temperature of the environment surrounding the injector drive circuit 10 and the battery.

  By adopting such a configuration, the length of the interval INT is more accurately set in a mode corresponding to the length of the period required for charging the injector drive circuit 10 and the injector drive circuit 10 that changes according to the temperature of the environment surrounding the battery. Can be set.

  Note that the temperature of the environment surrounding the injector drive circuit 10 and the battery can be estimated based on the engine coolant temperature THW, the temperature Ta of the air taken into the internal combustion engine, and the like. Therefore, specifically, the interval INT may be made longer as the engine coolant temperature THW and the air temperature Ta are lower.

  In addition, the length of the interval INT should just be set to the length which can eliminate the overlap of the injection period of each injection at least, and the length can be changed suitably. However, the longer the interval INT is set, the more likely the end timing of a series of injections exceeds the effective injection period when the injection timing of each injection is adjusted to ensure the interval INT. For this reason, it is desirable to set the length of the interval INT as short as possible within a range in which the overlapping of the injection periods of the respective injections can be ensured.

  In the above embodiment, the configuration in which it is determined in step S200 whether or not the processing margin M is secured is shown. On the other hand, when the processing time required to complete the opening / closing timing adjustment routine is extremely short and it is not necessary to secure the processing margin M, a process for determining whether or not the processing margin M is secured is performed. It can be omitted.

  In the above embodiment, in order to prevent a series of injections from exceeding the effective injection period, the configuration in which the injection timing is advanced from the subsequent injection is shown, but the injection timing is advanced from the subsequent injection. Even if the configuration is not adopted, it is possible to suppress the series of injections from exceeding the effective injection period if at least the injection end timing of the series of injections can be advanced.

  However, if the configuration in which the injection timing is advanced from the subsequent injection is not adopted, the injection end timing of a series of injections can be advanced unless the injection timings of a plurality of injections are advanced all at once. Can not. That is, it is far from the initially set injection start time.

  On the other hand, if the configuration in which the injection timing is advanced from the subsequent injection as in the above embodiment is adopted, the change in the injection timing more than necessary is effectively suppressed as described in (8) above. can do.

  That is, while performing a series of injections in a state as close as possible to the initially set injection start timing, it is possible to eliminate overlapping injection periods of the series of injections and to continue the series of injections after the effective injection period Can be suppressed.

  In the above embodiment, in order to suppress a series of injections from exceeding the effective injection period, a configuration in which the interval INT between the subsequent injection and the previous injection is eliminated to reduce the number of injections. As shown, it is possible to suppress a series of injections from exceeding the effective injection period by at least reducing the number of injections and advancing the injection end timing of the series of injections.

  However, when the configuration in which the number of injections is reduced by combining the subsequent injection with the previous injection is not adopted, the injection timings of the plurality of injections performed following the combined injection in accordance with the reduction in the number of injections If these are not advanced together, it is not possible to advance the injection end timing of a series of injections. That is, it is far from the initially set injection start time.

  On the other hand, if the configuration in which the injection timing is advanced by combining the subsequent injection and reducing the number of injections as in the above embodiment, the injection is performed as described in (10) above. It is possible to suppress the number of times and the change of the injection timing accompanying the reduction of the number of times of injection as much as possible.

That is, it is possible to suppress a series of injections from continuing to the effective injection period and thereafter while executing a series of injections in a state as close as possible to the initially set injection mode.
The opening / closing timing adjustment routine shown in the above embodiment is an example of a specific method for adjusting the injector opening / closing timing by prioritizing the number of injections over the injection timing and prioritizing the injection amount over the number of injections. is there.

  That is, if the opening / closing timing of the injector 20 is adjusted by prioritizing the number of injections over the injection timing and prioritizing the injection amount over the number of injections, the same effect as the above (1) can be obtained. The specific method can be changed as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Injector drive circuit, 20 ... Injector, 31 ... Air flow meter, 32 ... Crank position sensor, 33 ... Cam position sensor, 34 ... Water temperature sensor, 35 ... Voltage sensor, 36 ... Fuel pressure sensor, 100 ... Electronic control apparatus.

Claims (16)

In a control device for an internal combustion engine that executes multi-injection in which fuel to be burned in a single combustion stroke is divided into multiple injections,
When it is estimated that a series of injections performed in a plurality of times will continue until an effective injection period that is a period for effectively injecting fuel to be burned, the series of injections is based on that. Predict that they will not run properly,
When it is predicted that the series of injections cannot be performed properly,
Prioritizing keeping the number of injections in the series of injections over keeping the injection timing in each of the injections constituting the series of injections, and fueling the series of injections over keeping the number of injections in the series of injections Prioritize the protection of the injection amount of the injector and adjust the opening and closing timing of the injector ,
In order from the injection executed later among the plurality of injections related to the series of injections, the injection timing of the injection, the injection end timing of the previous injection executed before the injection, and the injection of the subsequent injection A range in which an interval that is set based on the length of the period from when the process for instructing the valve to close to the injector to when the injector is actually fully closed can be secured between the start time and the start time To advance the injection end timing of the series of injections,
When it is estimated that the series of injections will be completed within the effective injection period by advancing the injection timing, the adjustment of the opening / closing timing of the injector is terminated at that time. Engine control device. In a control device for an internal combustion engine that executes multi-injection in which fuel to be burned in a single combustion stroke is divided into multiple injections,
When it is estimated that a series of injections performed in a plurality of times will continue until an effective injection period that is a period for effectively injecting fuel to be burned, the series of injections is based on that. Predict that they will not run properly,
When it is predicted that the series of injections cannot be performed properly,
Prioritizing keeping the number of injections in the series of injections over keeping the injection timing in each of the injections constituting the series of injections, and fueling the series of injections over keeping the number of injections in the series of injections Prioritize the protection of the injection amount of the injector and adjust the opening and closing timing of the injector ,
The injector is closed between the injection end timing of the previous injection executed among the plurality of injections related to the series of injections and the injection start timing of the subsequent injection executed after the previous injection. The injection timing in the subsequent injection is retarded so as to ensure an interval set based on the length of the period from when the process of commanding the valve is performed until the injector is actually fully closed. After securing the interval between each injection in a series of injections,
The injection timing of the subsequent injection is advanced within a range in which the interval can be secured between the injection end timing of the previous injection and the injection start timing of the subsequent injection, and the injection related to the series of injections A control device for an internal combustion engine, wherein the end timing is advanced . The control apparatus for an internal combustion engine according to claim 2 ,
In order from the injection executed later among the plurality of injections related to the series of injections, the injection timing of the injection, the injection end timing of the previous injection executed before the injection, and the injection of the subsequent injection Advance in a range that can secure the interval between the start time,
When it is estimated that the series of injections will be completed within the effective injection period by advancing the injection timing, the adjustment of the opening / closing timing of the injector is terminated at that time. Engine control device. The control device for an internal combustion engine according to any one of claims 1 to 3 ,
When it is estimated that the series of injections continues after the effective injection period even after adjusting the injection timing, the subsequent injections are performed so as to eliminate the interval between the previous injections and the subsequent injections. The preceding injection timing and the subsequent injection are combined into one injection to reduce the number of injections, and the entire injection timing of the injection executed after the subsequent injection is advanced. A control device for an internal combustion engine. In a control device for an internal combustion engine that executes multi-injection in which fuel to be burned in a single combustion stroke is divided into multiple injections,
When it is estimated that a series of injections performed in a plurality of times will continue until an effective injection period that is a period for effectively injecting fuel to be burned, the series of injections is based on that. Predict that they will not run properly,
When it is predicted that the series of injections cannot be performed properly,
Prioritizing keeping the number of injections in the series of injections over keeping the injection timing in each of the injections constituting the series of injections, and fueling the series of injections over keeping the number of injections in the series of injections Prioritize the protection of the injection amount of the injector and adjust the opening and closing timing of the injector ,
If it is estimated that the series of injections will continue until the effective injection period after the adjustment of the injection timing, of the plurality of injections related to the series of injections, From the time when the injector is instructed to close the valve between the injection end timing and the injection start timing of the subsequent injection executed after the previous injection, until the injector is actually fully closed The preceding injection and the subsequent injection are combined into one injection by advancing the injection timing of the subsequent injection so as to eliminate the interval set based on the length of the period, and the number of injections is reduced. An internal combustion engine control apparatus for advancing the entire injection timing of injection executed after the subsequent injection . The control apparatus for an internal combustion engine according to claim 4 or 5 ,
In order from the plurality of injections in the series of injections, the number of injections is increased by advancing the injection timing of the subsequent injections so as to eliminate the interval between the previous injections and the subsequent injections in order from the subsequent injections. When it is estimated that the series of injections will be completed within the effective injection period by reducing and advancing the entire injection timing of the injection executed after the subsequent injection, at that time A control device for an internal combustion engine, wherein the adjustment of the opening / closing timing of the injector is terminated. When it is predicted that the series of injections cannot be performed properly,
First, adjust the injection timing in each injection constituting the series of injection,
When it is predicted that the series of injections cannot be properly executed even after adjusting the injection timing, two or more injections in the series of injections are combined into one to reduce the number of injections. ,
The control of the internal combustion engine according to any one of claims 1 to 6 , wherein when it is predicted that the series of injections cannot be performed properly, the fuel injection amount by the series of injections is decreased. apparatus. The control apparatus for an internal combustion engine according to any one of claims 1 to 7 ,
When it is estimated that the injection periods of the respective injections constituting the series of injections overlap, it is predicted based on that that the series of injections cannot be appropriately executed. apparatus. When the interval is not secured,
The control apparatus for an internal combustion engine according to claim 8 , wherein it is estimated that the injection periods of the injections constituting the series of injections overlap. The control apparatus for an internal combustion engine according to claim 9 ,
When it is estimated that the injection period of the previous injection executed first among the plurality of injections related to the series of injections and the injection period of the subsequent injection executed after the previous injection overlap.
A control apparatus for an internal combustion engine, wherein the injection start timing in the subsequent injection is delayed so as to ensure the interval between the injection end timing in the previous injection and the injection start timing of the subsequent injection. The control device for an internal combustion engine according to any one of claims 1 to 10 ,
When it is estimated that the series of injections will continue until the effective injection period even after the number of injections is reduced, the injection end timing of the series of injections is made to coincide with the end of the effective injection period. A control apparatus for an internal combustion engine, characterized in that an injection period for the series of injections is shortened and a fuel injection amount for the series of injections is reduced. The control device for an internal combustion engine according to any one of claims 1 to 11 , wherein the length of the interval is corrected according to a pressure of fuel supplied to the injector. The injector is opened using the electric charge charged in the drive circuit,
The control device for an internal combustion engine according to any one of claims 1 to 12 , wherein the length of the interval is set based on a time required for charging the drive circuit. The control device for an internal combustion engine according to claim 13 , wherein the length of the interval is corrected based on a voltage of a battery that supplies power to the drive circuit. The control device for an internal combustion engine according to claim 13 or 14 , wherein the length of the interval is corrected based on a temperature of an environment surrounding the drive circuit and a battery that supplies power to the drive circuit. The control apparatus for an internal combustion engine according to any one of claims 1 to 15 ,
Among the plurality of injections constituting the series of injections, the injection start timing of the injection executed first is a period corresponding to the processing time required for the control device to adjust the opening / closing timing of the injector. A control device for an internal combustion engine, wherein the control device is set so as to arrive after.

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