JP2019152144A - Injection control device - Google Patents

Abstract

To provide an injection control device capable of performing injection amount control reflecting the state of an engine while suppressing an increase in the load of arithmetic processing.SOLUTION: An engine control device functions as the injection control device for controlling a fuel injection by an injector. The engine control device acquires state information showing the state of the engine, and sets an injection time at fuel injection as a temporary injection time Tpr on the basis of the state information. The engine control device resets the injection time in the fuel injection as a determined injection time Tcn on the basis of the state information acquired after the temporary injection time Tpr is set. The engine control device sets calculation start timing tcs of the determined injection time Tcn so as to precede drive start timing tds of the fuel injection by a portion of a preceding time Tpt.SELECTED DRAWING: Figure 2

Description

  The disclosure according to this specification relates to an injection control device that controls a fuel injection valve.

  Conventionally, for example, Patent Document 1 discloses a fuel injection control device that controls a fuel injection valve so as to perform fuel injection twice in one combustion cycle toward an intake passage. The fuel injection control device of Patent Document 1 repeatedly calculates the required injection amount in the second fuel injection in the intake stroke based on the operating conditions of the engine. Then, the fuel of the injection amount calculated at the latest timing is injected from the fuel injection valve within a range in which the fuel injection can be completed by the intake valve closing timing.

JP 2007-332944 A

  Even in the case of controlling a so-called direct injection type fuel injection valve that performs fuel injection toward the cylinder instead of the intake passage, injection amount control reflecting the latest engine state is required. However, Patent Document 1 does not describe any injection amount control in the direct injection type fuel injection valve, and injection amount control in a short injection time associated with multiple injections in the intake process and the compression process. Is not described. In addition, in Patent Document 1, the calculation of the injection amount in the fuel injection is repeated many times in the intake stroke. Therefore, the calculation processing load for performing the injection may increase.

  The present disclosure provides an injection control device capable of controlling an injection amount that reflects the state of an engine even for fuel injection in an injection time shorter than a calculation time of an injection amount while suppressing an increase in calculation processing load. Objective.

  In order to achieve the above object, one disclosed aspect is an injection control for controlling the fuel injection valve (10) to inject fuel toward one cylinder (2b) provided in the internal combustion engine (2). An information acquisition unit (51) that acquires state information indicating a state of the internal combustion engine, and an injection time in fuel injection is set as a temporary injection time (Tpr) based on the state information. An injection setting unit (52) that resets the injection time in fuel injection as a fixed injection time (Tcn) based on state information acquired after the setting, and a calculation start timing (tcs) of the fixed injection time in the injection setting unit Is a timing adjustment unit (53) that sets the preceding time (Tpt) and the preceding time (Tpt) to the drive start timing (tds) of the fuel injection valve.

  In the above aspect, the calculation start timing of the fixed injection time is set so that it precedes the drive start timing of the fuel injection valve by the preceding time. Therefore, even if the injection time is short, the situation where the resetting calculation is not completed before the drive end timing of the fuel injection valve can be avoided.

  According to the above, the deterministic injection time reflecting the state information acquired after the temporary setting is used as the actual fuel injection time. Therefore, even if the calculation of the injection time is not repeated, the injection amount in the fuel injection can be a value reflecting new state information of the internal combustion engine. Therefore, it is possible to perform the injection amount control reflecting the state of the internal combustion engine while suppressing an increase in calculation processing load.

  Note that the reference numbers in the parentheses merely show an example of a correspondence relationship with a specific configuration in an embodiment described later, and do not limit the technical scope at all.

It is a figure which shows the whole structure of the fuel-injection control system containing an engine control apparatus. It is a timing chart which shows the detail of a process of the engine control apparatus in one combustion cycle. It is a timing chart which shows the calculation start timing in case a temporary injection time is more than a switching threshold compared with a drive start timing. It is a timing chart which shows the calculation start timing in case a temporary injection time is less than a switching threshold compared with a drive start timing. It is a timing chart which shows the detail of a process when the recalculation of injection time is not completed by a drive end timing. It is a flowchart which shows the detail of the main process in the injection time calculating process. It is a flowchart which shows the detail of the process at the time of 450 degrees CA before a top dead center or the process at the time of 270 degrees CA before a top dead center. It is a flowchart which shows the detail of preceding time pre-processing or a drive start timing process. It is a flowchart which shows the detail of a drive completion timing process.

  An engine control apparatus 100 according to an embodiment of the present disclosure is used in the fuel injection control system shown in FIG. The fuel injection control system is a system that controls the operation of a gasoline engine (hereinafter, “engine 2”), and includes a state sensor group 20, a plurality of injectors 10, an engine control device 100, and the like. The engine 2 is a spark ignition type internal combustion engine, and is mounted on a vehicle as a power source for generating power for traveling, for example.

  The state sensor group 20 is electrically connected to the engine control apparatus 100 directly or indirectly. The state sensor group 20 sequentially outputs detection results obtained by detecting the state of the engine 2 toward the engine control apparatus 100. The state sensor group 20 includes other sensors such as a rotation sensor 21, an air flow rate sensor 22, a water temperature sensor 23, an intake air temperature sensor 24, a fuel pressure sensor 25, and an accelerator position sensor.

  The rotation sensor 21 is, for example, an electromagnetic pickup. The rotation sensor 21 is combined with a signal rotor or the like to detect rotation of the crankshaft of the engine 2. The rotation sensor 21 sequentially outputs the detection result of the crankshaft angle to the engine control apparatus 100 as state information.

  The air flow rate sensor 22 is provided in an intake passage that is connected to each cylinder 2b. The air flow rate sensor 22 outputs a signal corresponding to the intake air amount sucked into each cylinder 2b as state information. The water temperature sensor 23 outputs a signal corresponding to the temperature of the cooling water for cooling the engine 2 as state information. The intake air temperature sensor 24 outputs a signal corresponding to the temperature of intake air taken into each cylinder 2b as state information. The fuel pressure sensor 25 outputs a signal corresponding to the pressure of the fuel supplied to each injector 10 as state information.

  The injector 10 is electrically connected to the engine control device 100. The injector 10 is inserted into an insertion hole 2c provided in the head member 2a of the engine 2, and is held by the head member 2a. The injector 10 is provided with a drive unit 12 such as an electromagnetic actuator and a piezoelectric actuator.

  The engine control apparatus 100 is an electronic control unit that controls the fuel supply to each cylinder 2b by the injector 10 based on the state information of the engine 2 acquired from the state sensor group 20. The engine control apparatus 100 is configured so that fuel injection is performed once or a plurality of times (for example, three times) according to the state of the engine 2 during the intake stroke and the compression stroke in one combustion cycle. The injector 10 is controlled. The control circuit of the engine control device 100 includes an injection valve driving unit 60 and a microcontroller (hereinafter referred to as “microcomputer 50”).

  The injection valve drive unit 60 supplies power for opening the injection holes 11 to the drive units 12 of the injectors 10 based on a control signal input from the microcomputer 50. Electric power is supplied to the injection valve drive unit 60 from, for example, a vehicle battery. The injection valve drive unit 60 starts fuel injection from the injection hole 11 by supplying electric power to the drive unit 12 at a timing according to the control signal and causing displacement of the valve body in the valve opening direction. Moreover, the injection valve drive part 60 stops the fuel supply from the injection hole 11 by stopping the power supply to the drive part 12 at a timing according to the control signal and causing the valve body to be displaced in the valve closing direction. .

  The microcomputer 50 is configured to have a processor and an input / output interface. The microcomputer 50 is provided with a storage unit 59. The storage unit 59 is a nonvolatile storage medium such as a flash memory. The storage unit 59 stores an operation system program executed by the microcomputer 50 and a plurality of application programs operating on the operation system. Note that the storage unit 59 may not be built in the microcomputer 50. The storage unit 59 may have a configuration of the engine control device 100 that is electrically connected to the microcomputer 50, or may be an aspect such as a memory card that is electrically connected to the engine control device 100.

  The microcomputer 50 constructs a plurality of functional units related to the fuel injection control by executing the injection control program stored in the storage unit 59. Specifically, in the microcomputer 50, an information acquisition unit 51, an injection setting unit 52, a timing adjustment unit 53, a completion determination unit 54, and the like are constructed as functional units.

  The information acquisition unit 51 acquires state information indicating the state of the engine 2 from the state sensor group 20. The acquisition of the state information by the information acquisition unit 51 is repeatedly performed at a predetermined cycle. The latest state information acquired by the information acquisition unit 51 is used for calculation for engine control in the microcomputer 50.

  The injection setting unit 52 generates a control signal output from the microcomputer 50 to the injection valve driving unit 60 based on the state information acquired by the information acquisition unit 51. Based on the state information, the injection setting unit 52 is configured to inject the total amount of fuel injected into each cylinder 2b in one combustion cycle, the number of fuel injections performed in one combustion cycle, and the number of fuel injections in each fuel injection. The injection amount and injection time to be performed, and the timing of the on-off valve are set. In the following description, the exhaust stroke, the intake stroke, the compression stroke, and the combustion (expansion) stroke are defined as one combustion cycle.

  The injection time set by the injection setting unit 52 is the time from the drive start timing tds instructing start of power supply to the drive unit 12 to the drive end timing tdf instructing stop of power supply. The injection setting unit 52 defines the drive start timing tds and the drive end timing tdf for each fuel injection by a control signal. The injection start timing at which the injection hole 11 of the injector 10 is switched from the valve closed state to the valve open state is later than the drive start timing tds. Similarly, the injection end timing at which the injection hole 11 is switched from the valve open state to the valve close state is after the drive end timing tdf.

  The injection setting unit 52 calculates the injection time of each fuel injection in one combustion cycle twice in principle. For a specific fuel injection (specific injection), the calculation of the first injection time is performed in the stroke immediately before the stroke in which the specific injection is actually performed. As an example, as shown in FIG. 2, it is assumed that fuel injection is performed once in the intake stroke and twice in the compression stroke in one combustion cycle. In this case, the initial calculation of the injection time in the fuel injection during intake is performed during the exhaust stroke. Similarly, the initial calculation of each injection time in the fuel injection at the time of compression is performed during the intake stroke. The injection time calculated in the stroke immediately before the fuel injection is set as the temporary injection time Tpr. The injection setting unit 52 (see FIG. 1) sets the drive start timing tds and the drive end timing tdf based on the temporary injection time Tpr.

  The injection setting unit 52 (see FIG. 1) starts recalculation of the injection time at a timing related to the drive start timing tds of the injector 10. For the calculation of the recalculated injection time (hereinafter, “determined injection time Tcn”), state information acquired after setting the temporary injection time Tpr is used. Therefore, the fixed injection time Tcn is a value reflecting state information that is newer than the temporary injection time Tpr. The injection setting unit 52 resets the drive end timing tdf based on the determined injection time Tcn that has been calculated before the drive end timing tdf. Thus, the injection amount according to the fixed injection time Tcn is supplied from the injector 10.

  The completion determination unit 54 (see FIG. 1) monitors the front-rear relationship between the calculation end timing tcf of the fixed injection time Tcn and the drive end timing tdf of the injector 10. The completion determination unit 54 compares the calculation end timing tcf with the drive end timing tdf, and determines whether or not the calculation of the fixed injection time Tcn has been completed by the drive end timing tdf of the injector 10. Specifically, the completion determination unit 54 turns on the flag for completion determination at the calculation start timing tcs of the fixed injection time Tcn, and turns off the flag at the calculation end timing tcf. Then, the completion determination unit 54 determines whether the recalculation is in time by determining the state of the flag at the drive end timing tdf.

  The timing adjustment unit 53 (see FIG. 1) sets the calculation start timing tcs of the fixed injection time Tcn) based on the drive start timing tds of the injector 10. The timing adjustment unit 53 adjusts the preceding time Tpt in which the calculation start timing tcs precedes the drive start timing tds according to the temporarily set temporary injection time Tpr. When the temporary injection time Tpr is equal to or longer than the switching threshold Tth (longer than the switching threshold Tth), the timing adjustment unit 53 sets the preceding time Tpt to zero as shown in the intake stroke of FIG. 2 and FIG. Thereby, the drive start timing tds and the calculation start timing tcs are set to substantially the same timing. In this case, since the injection time is longer than the switching threshold Tth, the calculation end timing tcf precedes the drive end timing tdf.

  On the other hand, when the temporary injection time Tpr is less than the switching threshold Tth (shorter than the switching threshold Tth), as shown in the compression stroke of FIG. 2 and FIG. 4, the timing adjustment unit 53 sets the preceding time Tpt to a value larger than zero. Set to. Then, the calculation start timing tcs precedes the drive start timing tds. As a result, even if the injection time is short, the calculation end timing tcf precedes the drive end timing tdf. In this case, the latest state information acquired at each calculation start timing tcs is reflected in the fixed injection time Tcn in each fuel injection.

  The timing adjustment unit 53 adjusts the length of the preceding time Tpt and the magnitude of the switching threshold Tth based on the determination result of the completion determination unit 54. As shown in FIG. 5, when multiple fuel injections are continuously repeated in one stroke (compression stroke), the timing adjustment unit 53 uses the determination result in the current (first) fuel injection, The preceding time Tpt at the next (second) calculation start timing tcs is adjusted.

  In FIG. 5, which is a specific example, for the first and second fuel injections, each temporary injection time Tpr longer than the switching threshold Tth is calculated by a calculation for temporary setting. Therefore, each calculation start timing tcs is set to the drive start timing tds. However, it is assumed that the calculation time of the fixed injection time Tcn in the first fuel injection is longer than the actual injection time, and the calculation of the fixed injection time Tcn is not completed by the drive end timing tdf. In this case, the timing adjustment unit 53 adjusts the preceding time Tpt in the second fuel injection longer than the preceding time Tpt (zero) in the first fuel injection, and the preceding time Tpt (> 0) of the drive start timing tds. The calculation start timing tcs is reset before. According to the above adjustment, the calculation completion of the fixed injection time Tcn precedes the drive end timing tdf. Therefore, the driving end timing tdf can be reset based on the fixed injection time Tcn.

  When the temporary injection time Tpr is less than the switching threshold Tth and the calculation start of the fixed injection time Tcn is advanced, the timing adjustment unit 53 determines that the calculation is not completed by the drive end timing tdf. Tpt is lengthened (see S120 in FIG. 8). On the other hand, when the calculation start of the fixed injection time Tcn is advanced and the situation where the calculation is completed by the drive end timing tdf continues for a predetermined period TP, the timing adjustment unit 53 shortens the preceding time Tpt ( FIG. 8 S117). Such adjustment of the preceding time Tpt is performed in stages.

  The timing adjustment unit 53 increases the switching threshold Tth when the temporary injection time Tpr is equal to or longer than the switching threshold Tth and the calculation of the fixed injection time Tcn started at the driving start timing tds is not completed by the driving end timing tdf. (See FIG. 8, S121). On the other hand, for the calculation of the fixed injection time Tcn started at the drive start timing tds, when the situation completed by the drive end timing tdf continues for a predetermined period TP, the timing adjustment unit 53 decreases the switching threshold Tth (FIG. 8 S118). Such adjustment of the switching threshold Tth is also performed in stages.

  Details of the injection time calculation process performed by the microcomputer 50 will be further described with reference to FIG. 1 based on FIGS. The injection time calculation process shown in FIGS. 6 to 9 is started by starting the engine 2 and repeatedly started until the engine 2 is stopped.

  In S <b> 11 of the main process shown in FIG. 6, the crankshaft angle (angular position) is determined based on the state information detected by the rotation sensor 21. In S11, if the crank position is 450 ° CA or 270 ° CA before top dead center, the process proceeds to S12. In S12, processing at 450 ° CA before top dead center or processing at 270 ° CA before top dead center (see FIG. 7) is executed, and the main processing is temporarily terminated.

  When it is determined in S11 that the crank position is neither 450 ° CA before top dead center nor 270 ° CA, the process proceeds to S13. In S13, it is determined whether or not it is time to reset the injection time. As described above, the resetting timing is the timing set by the timing adjustment unit 53 and is before the driving start timing tds or its preceding time Tpt. If it is determined in S13 that the reset timing is reached, the process proceeds to S14. In S14, the preceding time pre-process or the drive start timing process (see FIG. 8) is executed, and the main process is temporarily terminated.

  When it is determined in S13 that it is not the reset timing, the process proceeds to S15. In S15, it is determined whether or not the drive end timing tdf has been reached. If it is determined in S15 that the driving end timing tdf is not reached, the main process is temporarily ended. On the other hand, when it determines with it being drive end timing tdf in S15, it progresses to S16. In S16, a drive end timing process (see FIG. 9) is executed, and the main process is temporarily ended.

  In the processing at 450 ° CA before top dead center or the processing at 270 ° CA before top dead center shown in FIG. 7, the adjustment of the preceding time Tpt based on the temporary injection time Tpr is performed. In S101, as in S10, the angular position of the crankshaft is determined. If it is determined in S101 that the crank position is 450 ° CA before top dead center, the process proceeds to S102. In S102, the total injection amount, injection time (temporary injection time Tpr), and drive start timing tds required for one fuel injection performed in the intake stroke are calculated, and the process proceeds to S104 (see FIG. 2).

  On the other hand, if it is determined in S101 that the crank position is 270 ° CA before top dead center, the process proceeds to S103. In S103, the total injection amount required in the two fuel injections performed in the compression stroke, each injection time (temporary injection time Tpr), and drive start timing tds are calculated, and the process proceeds to S104 (see FIG. 2).

  In S104, the temporary injection time Tpr set in S102 or S103 is compared with the switching threshold Tth. If it is determined in S104 that the temporary injection time Tpr is less than the switching threshold Tth, the process proceeds to S105. In S105, in consideration of the short injection time, the calculation start timing tcs of the fixed injection time Tcn is set before the preceding time Tpt with respect to the drive start timing tds (see FIG. 4), and the process is terminated.

  On the other hand, when it is determined in S104 that the temporary injection time Tpr is equal to or longer than the switching threshold Tth, the process proceeds to S106. In S106, considering that there is a margin in the injection time, the calculation start timing tcs of the fixed injection time Tcn is set to the drive start timing tds, and the process ends (see FIG. 3).

  In the preceding time pre-process or the drive start timing process shown in FIG. 8, the preceding time Tpt and the switching threshold Tth are adjusted. In S111, the stroke of the fuel injection being performed is determined. When it is determined in S111 that the intake stroke is being injected, the process proceeds to S112. In S112, calculation of the fixed injection time Tcn in the fuel injection in the intake stroke and resetting of the drive end timing tdf are performed, and the process proceeds to S114. On the other hand, if it is determined in S111 that the compression stroke is being injected, the process proceeds to S113. In S113, the fixed injection time Tcn in the fuel injection in the compression stroke is calculated and the drive end timing tdf is reset, and the process proceeds to S114.

  In S114, it is determined whether or not the drive end timing tdf has been reset in S112 or S113. If it is determined in S114 that the driving end timing tdf has been reset by completing the calculation of the fixed injection time Tcn, the process proceeds to S115. On the other hand, if it is determined in S114 that the drive end timing tdf cannot be reset, the drive end timing tdf initially set based on the temporary injection time Tpr is reached, and the calculation of the fixed injection time Tcn is not in time. The process proceeds to S119.

  In S115, it is determined whether or not the situation in which the drive end timing tdf can be reset continues for a predetermined period TP. If it is determined in S115 that the resettable situation has not continued for the predetermined period TP, the process ends. On the other hand, if it is determined in S115 that the resettable situation has continued for a predetermined period TP, the process proceeds to S116.

  In S116, the calculation start timing tcs at which recalculation of the fixed injection time Tcn is started is confirmed. If it is determined in S116 that the calculation start timing tcs is before the drive start timing tds, the process proceeds to S117. In S117, a value for shortening the preceding time Tpt by a predetermined time (for example, 10 μs) is updated, and the process is terminated. On the other hand, when it is determined in S116 that the calculation start timing tcs is the drive start timing tds, the process proceeds to S118. In S118, a value for decreasing the switching threshold Tth by a predetermined time (for example, 10 μs) is updated, and the process is terminated. In the processes of S117 and S118, the preceding time Tpt and the switching threshold Tth are adjusted within a range that does not become zero.

  In S119, as in S116, the calculation start timing tcs of the fixed injection time Tcn is confirmed. If it is determined in S119 that the calculation start timing tcs is before the driving start timing tds, the process proceeds to S120. In S120, an update is performed to increase the preceding time Tpt by a predetermined time (for example, 50 μsec), and the process ends. On the other hand, if it is determined in S119 that the calculation start timing tcs is the drive start timing tds, the process proceeds to S121.

  In S121, a value for increasing the switching threshold Tth by a predetermined time (for example, 50 μs) is updated, and the process is terminated. By such processing, for example, when the calculation is not completed in the first fuel injection among a plurality of times (see FIG. 5), not only the second calculation start timing tcs is advanced, but also the switching threshold Tth is increased ( Adjustment) is performed.

  In the drive end timing process shown in FIG. 9, the state of the previous fuel injection is reflected in the second and subsequent injection modes in the same stroke. In S131, as in S114 (see FIG. 8), it is determined whether or not the calculation of the fixed injection time Tcn is in time for the drive end timing tdf. If it is determined in S131 that the calculation of the fixed injection time Tcn is in time, the process proceeds to S133. On the other hand, when it is determined that the calculation of the fixed injection time Tcn is not in time, the process proceeds to S132. In S132, the calculation start timing tcs in the next fuel injection is set before the preceding time Tpt of the drive start timing tds (see FIG. 5), and the process proceeds to S133.

  In S133, the fuel injection amount already injected by the injector 10 is calculated from the actual injection time in the immediately preceding fuel injection, and the process proceeds to S134. In S134, the stroke in which fuel injection is performed is determined in the same manner as in S111 (see FIG. 8). If it is determined in S134 that the intake stroke is being injected, the process proceeds to S135. In S135, by subtracting the current fuel injection amount calculated in S133 from the total injection amount in the intake stroke injection (see S102 in FIG. 7), the remaining amount to be injected by the subsequent fuel injection (hereinafter referred to as “remaining injection”). Amount ") is calculated, and the process proceeds to S137. On the other hand, if it is determined in S134 that the compression stroke is being injected, the process proceeds to S136. In S135, the remaining injection amount is calculated by subtracting the current fuel injection amount from the total injection amount in the compression stroke injection (see S103 in FIG. 7), and the process proceeds to S137.

  In S137, the remaining injection time for injecting the remaining injection amount is calculated from the remaining injection amount calculated in S135 or S136 with reference to state information such as the fuel pressure, and the process proceeds to S138. In S138, it is determined whether or not the next fuel injection is necessary based on the remaining injection amount. In S138, if the remaining injection amount is very small, it is determined that the next fuel injection is unnecessary, and the process is terminated. On the other hand, if it is determined in S138 that the remaining injection amount is not small, it is determined that the next fuel injection is necessary, and the process proceeds to S139.

  In S139, the remaining injection time calculated in S137 is compared with the switching threshold Tth. If it is determined in S139 that the remaining injection time is less than the switching threshold Tth, the process proceeds to S140. In S140, the calculation start timing tcs in the next fuel injection is set before the preceding time Tpt of the drive start timing tds, and the process ends. According to the above, even when the remaining injection time is shorter than the scheduled temporary injection time Tpr, the preceding time Tpt is appropriately set based on the remaining injection time. On the other hand, when it determines with remaining injection time being more than switching threshold value Tth in S139, a process is complete | finished as it is.

  As described so far, in the present embodiment, the calculation start timing tcs of the fixed injection time Tcn is set so as to precede the drive start timing tds on the basis of the drive start timing tds of fuel injection. As described above, when the drive start timing tds set together with the temporary injection time Tpr is used as a reference, a situation where the reset calculation is not completed by the drive end timing tdf even if the injection time in the fuel injection is short is avoided. obtain.

  According to the above, the fixed injection time Tcn reflecting the state information acquired after the temporary setting is used as the actual fuel injection time. Therefore, even if the calculation of the injection time is not repeated, the injection amount in the fuel injection can be a value reflecting new state information of the engine 2. Therefore, it is possible to control the injection amount that reflects the state of the engine 2 while suppressing an increase in the processing load even for fuel injection with an injection time shorter than the injection amount calculation time.

  In addition, in the present embodiment, the preceding time Tpt of the calculation start timing is adjusted according to the temporary injection time Tpr. Specifically, when the temporary injection time Tpr is less than the switching threshold Tth, the preceding time Tpt is adjusted to be longer than when the temporary injection time Tpr exceeds the switching threshold Tth. Therefore, the recalculation of the injection time can be completed by the drive end timing tdf with higher certainty. Further, if the control is to switch the preceding time Tpt in a binary manner by comparing the temporary injection time Tpr and the switching threshold Tth, a method of performing an interpolation operation from the table according to the temporary injection time or a function using the temporary injection time as an argument The amount of computation required is smaller than when computing. Therefore, if the switching control is based on the switching threshold Tth, an increase in the processing load for adjusting the preceding time Tpt can be suppressed.

  In the present embodiment, when the temporary injection time Tpr is equal to or longer than the switching threshold Tth, the preceding time Tpt is substantially zero. As a result, the calculation start timing tcs is set to coincide with the drive start timing tds. According to such setting, the state information acquired immediately before the start of driving of the injector 10 can be used for the calculation of the fixed injection time Tcn. Therefore, the injection amount control reflecting the latest state of the engine 2 is performed.

  Furthermore, in this embodiment, when the calculation of the fixed injection time Tcn in the current fuel injection is not completed by the drive end timing tdf, the calculation start timing tcs in the next fuel injection is forcibly set to the drive start timing tds. It is set before the preceding time Tpt. According to such control, in the next fuel injection, the calculation of the fixed injection time Tcn can be completed by the drive end timing tdf. Therefore, the latest state of the engine 2 is more easily reflected in the injection amount control.

  In addition, in this embodiment, when the drive end timing tdf is not reset by the calculation of the fixed injection time Tcn, the switching threshold Tth or the preceding time Tpt is updated. Specifically, if the calculation of the fixed injection time Tcn started at the drive start timing tds is not in time, the switching threshold Tth is increased (see S121 in FIG. 8). According to the above adjustment, the scene in which the calculation start timing tcs is set before the preceding time Tpt is expanded. As a result, the certainty of completing the calculation of the fixed injection time Tcn by the drive end timing tdf is further improved.

  Furthermore, in this embodiment, when the calculation of the fixed injection time Tcn started before the preceding time Tpt is not in time, the preceding time Tpt is lengthened (see S120 in FIG. 8). If the calculation start timing tcs is further advanced by such adjustment, it is easy to secure the calculation time of the fixed injection time Tcn even if the injection time is very short.

  In the present embodiment, the switching threshold Tth or the preceding time Tpt is also updated when the drive end timing tdf can be reset again for a predetermined period TP. Specifically, the switching threshold Tth is reduced by continuing the situation in which the calculation of the fixed injection time Tcn started at the drive start timing tds is in time (see S118 in FIG. 8). According to the above adjustment, the situation where the unnecessary preceding time Tpt is ensured in a scene where the calculation time of the fixed injection time Tcn can be sufficiently secured is avoided. As a result, the latest state information is easily reflected in the fixed injection time Tcn.

  Furthermore, in the present embodiment, the preceding time Tpt is shortened by continuing the situation where the calculation of the fixed injection time Tcn started before the preceding time Tpt is matched (see S117 in FIG. 8). If the calculation start timing tcs is delayed by such adjustment, newer state information can be reflected in the calculation of the fixed injection time Tcn.

  In addition, in the present embodiment, adjustment is made as to whether or not the preceding time Tpt is made zero according to the remaining injection time (see FIG. 9). According to such adjustment, as a result of actually performing fuel injection, even if a difference occurs between the temporarily set injection amount and the remaining injection amount and the validity of the temporary injection time Tpr is lost, the subsequent fuel injection is performed. Then, the calculation start timing tcs can be appropriately set based on the remaining injection time. According to the above, even when a plurality of fuel injections are continuously performed, the injection amount control reflecting the state of the engine 2 can be continuously performed.

  In this embodiment, the engine 2 corresponds to an “internal combustion engine”, the injector 10 corresponds to a “fuel injection valve”, the microcomputer 50 corresponds to a “processing unit”, and the engine control device 100 corresponds to an “injection control device”. Is equivalent to.

(Other embodiments)
Although one embodiment of the present disclosure has been described above, the present disclosure is not construed as being limited to the above-described embodiment, and can be applied to various embodiments and combinations without departing from the scope of the present disclosure. be able to. For example, each configuration described in the above embodiment can be appropriately combined with each configuration described in the following modifications and the like as long as the combination is not particularly hindered. Furthermore, the configurations described in the following modifications and the like may be combined as appropriate.

  The timing adjustment unit of the above embodiment has determined whether or not to set the preceding time to zero based on the comparison between the temporary injection time and the switching threshold value. However, the method for adjusting the preceding time by the timing adjustment unit may be changed as appropriate. For example, the timing adjustment unit of Modification 1 stores a table or function for setting the preceding time from the temporary injection time. The timing adjustment unit sets the preceding time by a calculation process that applies the temporary injection time to a table or a function. The preceding time may change stepwise depending on the provisional injection time, or may change continuously.

  In addition, a plurality (two or more) of switching threshold values are set in the timing adjustment unit of the second modification. The timing adjustment unit can switch the length of the preceding time stepwise in a range of 0 or more based on the comparison between the temporary injection time and a plurality of switching threshold values. When the switching threshold and the temporary injection time are substantially equal, the preceding time may be a non-zero value as in the above embodiment, or may be set to zero. As described above, the handling of the boundary value that matches the switching threshold may be changed as appropriate.

  The calculation start timing in the above embodiment is set to a time that substantially matches the drive start timing when the temporary injection time is equal to or greater than the switching threshold. However, the adjustment range of the calculation start timing can be changed as appropriate. For example, the calculation start timing in Modification 3 is defined after the drive start timing when it is set the latest. In addition, the calculation start timing in Modification 4 is defined before the drive start timing tds even if it is set the latest.

  In the above embodiment, the preceding time and the switching threshold are adjusted based on the result of completion determination by the completion determination unit. However, the advance time and the switching threshold need not be adjusted. Alternatively, among these values, only the preceding time may be adjusted, or only the switching threshold value may be adjusted. In these forms, the calculation load of the microcomputer can be further reduced.

  The calculation start timing in the embodiment has been adjusted based on the length of the temporary injection time. However, the calculation start timing in the modified example 5 precedes this drive start timing by a fixed time with reference to the drive start timing set at the time of calculating the temporary injection time, regardless of the length of the temporary injection time. Set to Even in the fifth modified example, the calculation of the fixed injection time can be completed by the drive end timing by securing the preceding time. In addition, according to the setting of the calculation start timing based on the drive start timing, even when the drive start timing is around, new state information is appropriately used for calculation of the determined injection time. Therefore, also in the modified example 5, it is possible to perform the injection amount control reflecting the state of the engine while suppressing an increase in the processing load.

  In the above embodiment, the preceding time and the switching threshold are adjusted in a range larger than zero. However, the adjustment range of the preceding time and the switching threshold can be changed as appropriate. For example, the preceding time and the switching threshold value may be adjusted within a predetermined value range (> 0). Furthermore, an upper limit may be provided for each adjustment range of the preceding time and the switching threshold.

  In the above embodiment, the process of calculating the temporary injection time and the like has been started at 450 ° CA before top dead center or 270 ° CA before top dead center. However, the start timing of such temporary setting calculation may be changed as appropriate as long as a time margin can be secured before the drive start timing. Further, the number of injections in the intake stroke and the compression stroke can be changed as appropriate. Further, the fuel injection corresponding to the “specific injection” among the multiple fuel injections may be changed as appropriate. Such fuel injection corresponding to “specific injection” may be performed a plurality of times in one combustion cycle.

  The timing adjustment unit in the above embodiment calculates the remaining injection amount obtained by subtracting the injected fuel amount from the required total injection amount, and adjusts the preceding time based on the remaining injection amount. However, the correction process based on the actual injection amount may be omitted for the purpose of reducing the load on the microcomputer.

  In the above embodiment, the function provided by the control circuit of the engine control device can be provided by hardware and software different from those described above, or a combination thereof. For example, the engine control device may be an electronic control unit that includes only a configuration corresponding to a microcomputer and outputs a control signal to a drive device having a function corresponding to an injection valve drive unit.

  In the above-described embodiment, the example in which the injection control method of the present disclosure is applied to the engine control apparatus that controls gasoline injection by the fuel injection valve has been described. However, the above injection control method can also be applied to an engine control apparatus that controls a fuel injection valve that injects fuel other than gasoline, such as light oil.

  In the above-described embodiment, the example in which the engine control device is applied to the fuel injection control system that controls the in-vehicle engine has been described. However, the engine to be controlled by the engine control device is not limited to the in-vehicle engine, but may be an engine mounted on various transport devices and an engine used for various consumer devices.

2 engine (internal combustion engine), 2b cylinder, 10 injector (fuel injection valve), 50 microcomputer (processing unit), 51 information acquisition unit, 52 injection setting unit, 53 timing adjustment unit, 54 completion determination unit, 100 engine control device ( Injection control device), Tpr temporary injection time, Tcn fixed injection time, tcs calculation start timing, Tpt preceding time, Tth switching threshold, tds drive start timing, tdf drive end timing, TP predetermined period

Claims (11)

An injection control device that controls a fuel injection valve (10) to inject fuel toward one cylinder (2b) provided in an internal combustion engine (2),
An information acquisition unit (51) for acquiring state information indicating the state of the internal combustion engine;
Based on the state information, an injection time in fuel injection is set as a temporary injection time (Tpr), and an injection time in the fuel injection is determined based on the state information acquired after setting the temporary injection time. An injection setting unit (52) to be reset as (Tcn);
Timing adjustment unit (53) for setting the calculation start timing (tcs) of the fixed injection time in the injection setting unit to precede the fuel injection valve drive start timing (tds) by a preceding time (Tpt). ).   The injection control device according to claim 1, wherein the timing adjustment unit adjusts the preceding time (Tpt) in which the calculation start timing precedes the drive start timing in accordance with the temporary injection time.   The timing adjustment unit, when the temporary injection time is less than the switching threshold (Tth), makes the preceding time longer than when the temporary injection time exceeds the switching threshold. Injection control device.   The injection control device according to claim 3, wherein the timing adjustment unit sets the drive start timing and the calculation start timing to substantially the same timing when the temporary injection time exceeds the switching threshold.   The completion determination part (54) which determines whether the calculation of the said fixed injection time in the said injection setting part was completed by the drive end timing (tdf) of the said fuel injection valve is further provided in Claim 3 or 4 The injection control device described.   6. The timing adjustment unit according to claim 5, wherein the calculation start timing in the next fuel injection precedes the drive start timing when the calculation of the fixed injection time is not completed by the drive end timing. Injection control device.   The timing adjustment unit increases the switching threshold when the temporary injection time exceeds the switching threshold and the calculation of the fixed injection time is not completed by the driving end timing. The injection control device according to 5 or 6.   The timing adjustment unit, when the provisional injection time exceeds the switching threshold and the situation where the calculation of the fixed injection time is completed by the driving end timing continues for a predetermined period (TP), The injection control device according to any one of claims 5 to 7, wherein the switching threshold value is reduced.   The timing adjustment unit increases the preceding time when the temporary injection time is less than the switching threshold and the calculation of the fixed injection time is not completed by the drive end timing. The injection control apparatus as described in any one of -8.   The timing adjustment unit, when the temporary injection time is less than the switching threshold and the situation where the calculation of the fixed injection time is completed by the driving end timing continues for a predetermined period (TP), The injection control device according to any one of claims 5 to 9, wherein the time is shortened. The injection setting unit calculates a remaining injection amount obtained by subtracting an injected injection amount from a total injection amount required in one fuel injection, and a remaining injection time for injecting the remaining injection amount,
The said timing adjustment part is an injection control apparatus as described in any one of Claims 1-10 which adjusts the said preceding time according to the said remaining injection time.

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