JP6497217B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine that is controlled by an internal combustion engine that includes a fuel injection valve that opens by energizing a coil.

  For example, as seen in Patent Document 1, after a valve opening voltage is applied to a coil built in a fuel injection valve to increase the current flowing through the coil, a holding voltage smaller than the valve opening voltage is intermittently applied to the coil. Devices have been proposed in which a current that flows through a coil when applied is used as a holding current value. In particular, in this device, the time for applying the valve opening voltage to the coil is fixed, and the peak current, which is the maximum value of the current flowing through the coil when the valve opening voltage is applied to the coil, is feedback controlled to the command value. Manipulating the magnitude of the valve opening voltage.

JP 2010-249069 A

  By the way, in the case of the said apparatus, when the detected value of the electric current which flows into a coil has an error with respect to the value of the electric current which has actually flowed in the coil, the controllability of a peak current falls. A decrease in controllability of the peak current causes a decrease in controllability of the injection amount of the fuel injection valve.

  The present invention has been made in view of such circumstances, and an object of the present invention is to suppress a decrease in the controllability of the injection amount of the fuel injection valve even when the detected value of the current flowing through the coil includes an error. An object of the present invention is to provide a control device for an internal combustion engine.

Hereinafter, means for solving the above-described problems and the effects thereof will be described. The correspondence relationship between the invention described in the claims and the following means is as follows. The invention according to claim 1 adds the “command value setting processing unit for setting the peak current command value to a larger value as the injection pressure of the fuel injection valve is higher ” in the following 1, and the reference time is “the coil The invention according to claim 2 is based on the following 2 in (a) “based on the injection pressure, A valve opening current value calculation processing unit for calculating a valve opening current value that is a current flowing through the coil when the fuel injection valve is switched from a valve closing state to a valve opening state; and (b) valve opening current arrival time. The detection processing unit “detects a valve opening current arrival time, which is a time required from when the voltage of the power supply is applied to the coil until the current acquired by the acquisition processing unit becomes the valve opening current value”. specify a point, the reference value " The current flowing through the serial coils has specify that the current flowing through the time and the coil required until the said valve-opening current value is the reference value of the ratio "of the time taken to reach the peak current command value The invention according to claim 3 corresponds to the one that is consistent with the correction of (a) in 3 below, and the invention according to claim 4 has the invention specifying matters according to 4 below. Corresponding to the dependent claim, the invention according to claim 5 is consistent with the invention according to claim 1 in the following 5, and the reference time setting processing unit indicates that “the higher the injection pressure, the longer the reference time. Or the processing for setting the reference time to a longer time as the peak current command value is larger. 6 (c The high-voltage power supply is a booster circuit, (d) the point that “the terminal voltage of the battery lower than the boosted voltage can be applied” is applied to the coil, and (e) the holding current processing unit is “stopped” By applying the terminal voltage of the battery to the coil intermittently during the fuel injection period of the fuel injection valve when the application of the boost voltage of the booster circuit is stopped by the processing unit, the current flowing through the coil is This corresponds to the correction of the “control to a predetermined holding current value smaller than the peak current command value”.
1. A control device for an internal combustion engine targets an internal combustion engine provided with a fuel injection valve that opens by energizing the coil, obtains a current flowing in the coil, and applies a power supply voltage to the coil And the application of the power supply is stopped when the current acquired by the acquisition processing unit reaches a command value when the power supply voltage is applied to the coil by the application processing unit. Peak current arrival time detection for detecting a peak current arrival time which is a time required for the current acquired by the acquisition processing unit to reach the command value after the voltage of the power source is applied to the coil When the peak current arrival time detected by the processing unit and the detected peak current is shorter than the reference time, the peak current command value is increased and corrected, and when it is longer than the reference time, the peak current command value is corrected. Comprising a correction processing section that reduces correcting leakage current command value.

  In the above configuration, the current flowing through the coil is gradually increased by applying the voltage of the power source to the coil by the application processing unit. Then, when the detected value of the current flowing through the coil becomes the peak current command value, the application of the power supply voltage is stopped. Here, if there is an error in the detected value of the current flowing through the coil (current value acquired by the acquisition processing unit), if the error is a value that is smaller than the actual current, the detected value is The peak current arrival time, which is the time required to reach the peak current command value, is detected as a time longer than the time required for the actual current to reach the peak current command value. On the other hand, if the detected value error is such that the detected value is larger than the actual current, the peak current arrival time, which is the time required for the detected value to become the peak current command value, It is detected as a time shorter than the time required to reach the current command value.

  Here, in the above configuration, when the peak current arrival time is shorter than the reference time, the correction processing unit increases and corrects the peak current command value, so that the detected value error is larger than the actual current. In this case, the peak current command value is increased and corrected. Thereby, even when the detected value includes an error, the timing at which the application of the power supply voltage is stopped by the stop processing unit can be brought close to the timing at which the actual current flowing through the coil becomes the peak current command value. .

  Further, in the above configuration, when the peak current arrival time is longer than the reference time by the correction processing unit, the peak current command value is decreased and corrected, so that the detection value error is set to a value smaller than the actual current. If it is, the peak current command value is corrected to decrease. Thereby, even when the detected value includes an error, the timing at which the application of the power supply voltage is stopped by the stop processing unit can be brought close to the timing at which the actual current flowing through the coil becomes the peak current command value. .

Therefore, in the above configuration, it is possible to suppress a decrease in the controllability of the injection amount of the fuel injection valve even if the detected value of the current flowing through the coil includes an error.
2. In the control apparatus for an internal combustion engine according to 1, the correction processing unit is configured such that the current acquired by the acquisition processing unit is a current flowing through the coil when the fuel injection valve is switched from a closed state to a opened state. A valve opening current arrival time detection processing unit that detects a valve opening current arrival time that is a time required to reach a certain valve opening current value, and an arrival time that is a ratio of the valve opening current arrival time and the peak current arrival time A comparison of the detected peak current arrival time and the reference time by comparing the arrival time ratio calculation processing unit for calculating the ratio and the arrival time ratio calculated by the arrival time ratio calculation processing unit with a reference value And a comparison processing unit.

  In the above configuration, when there is an error in the current (detected value) acquired by the acquisition processing unit, an error occurs in both the peak current arrival time and the valve opening current arrival time. By the way, in the actual fuel injection valve, the voltage of the power source decreases due to discharge, or the change speed of the current flowing through the coil changes before and after the fuel injection valve is opened. Tend to. And, when the current flowing through the coil is near the valve opening current value and when the current change rate is different from the peak current command value, the valve opening current arrival time and the peak current arrival are different. Differences occur in each time error. In the above configuration, paying attention to this difference, the detected peak current arrival time is compared with the reference time based on the comparison between the arrival time ratio and the reference value.

  For example, taking the case where the rate of change when near the peak current command value is greater than the rate of change when near the valve opening current value as an example, the following is obtained. If the arrival time ratio denominator is the valve opening current arrival time, the detection value is larger than the actual current when the arrival time ratio based on the detection value is larger than the reference value of the arrival time ratio, When the value is smaller than the value, the detected value is considered to be a value smaller than the actual current. On the other hand, if the denominator of the arrival time ratio is the peak current arrival time, the detection value becomes smaller than the actual current when the arrival time ratio based on the detection value is larger than the reference value of the arrival time ratio. Therefore, when the value is smaller than the reference value, the detected value is considered to be larger than the actual current.

  Thus, based on the magnitude comparison between the arrival time ratio and the reference value, the magnitude comparison between the detected peak current arrival time and the reference time can be performed. In particular, the current flowing through the coil changes depending on the temperature of the coil, but even if the current flowing through the coil changes according to the temperature, the magnitude relationship between the arrival time ratio and the reference value, and the detected value The correspondence relationship between the actual current and the magnitude relationship does not change. For this reason, by comparing the arrival time ratio with the reference value, it can be equivalent to the comparison between the peak current arrival time and the reference time corresponding to the coil temperature. Therefore, in the above configuration, the peak current command value can be appropriately corrected according to the error included in the detected value of the current flowing through the coil regardless of the temperature of the coil.

  3. 3. The control apparatus for an internal combustion engine according to claim 2, wherein the fuel pressure control processing unit that variably controls the injection pressure of the fuel injection valve, and the fuel injection valve is switched from the closed state to the open state based on the injection pressure. A valve opening current value calculation processing unit that calculates a valve opening current value that is a current flowing through the coil.

In the above configuration, since the injection pressure of the fuel injection valve is variably controlled, the valve opening current value changes according to the injection pressure. Therefore, in the above configuration, the valve opening current value is calculated based on the injection pressure.
4). 4. The control apparatus for an internal combustion engine according to claim 2 or 3, wherein the fuel injection valve is configured such that the fuel injection valve is switched from a closed state to an open state even when the voltage applied to the coil is the same. The increasing acceleration of the current flowing through the is positive.

In the above configuration, the rate of change when it is near the peak current command value is greater than when it is near the valve opening current value.
5). 2. The control apparatus for an internal combustion engine according to claim 1, wherein a fuel pressure control processing unit that variably controls an injection pressure of the fuel injection valve, a command value setting processing unit that sets the peak current command value based on the injection pressure, and the injection A reference time setting processing unit that sets the reference time based on the pressure or the peak current command value, and the correction processing unit determines whether the detected peak current arrival time is larger or smaller than the set reference time. Based on the comparison, the peak current command value is corrected.

  In the above configuration, since the injection pressure of the fuel injection valve is variably controlled and the peak current command value is set according to the injection pressure, the time required for the actual current to reach the peak current command value is the peak current command value. Depends on value and injection pressure. For this reason, in the above configuration, the reference time is set based on the injection pressure and the peak current command value.

  6). 6. The control apparatus for an internal combustion engine according to any one of 1 to 5, wherein the power source is a high voltage power source, and the coil has a voltage of a low voltage power source that is lower than a voltage of the high voltage power source. The application of the voltage of the high-voltage power supply is stopped by the stop processing unit, and the voltage of the low-voltage power supply is intermittently applied to the coil during the fuel injection period by the fuel injection valve. A holding current processing unit that controls the current flowing through the coil to a predetermined holding current value smaller than the peak current command value by applying the coil is provided.

  In the above configuration, after the current flowing through the coil reaches the peak current command value, the control is switched to the control of the current value flowing through the coil to the holding current value. In such a configuration, if the control to the holding current value is finished before the lift amount reaches the maximum, the maximum value of the current flowing through the coil deviates from the peak current command value, thereby causing a large error in the fuel injection amount. There is a fear. For this reason, when performing so-called partial lift injection in which fuel injection is terminated before the lift amount reaches the maximum, the utility value of the correction processing unit is particularly great.

The system block diagram provided with the control apparatus of the internal combustion engine concerning 1st Embodiment. Sectional drawing which shows a partial structure of the fuel injection valve concerning the embodiment. The circuit diagram which shows the circuit structure of the control apparatus concerning the embodiment. The flowchart which shows the process sequence of the fuel-injection control concerning the embodiment. (A)-(g) is a time chart of the fuel-injection control concerning the embodiment. The flowchart which shows the procedure of the correction process of the command value of the peak current concerning the embodiment. The flowchart which shows the procedure of the correction process of the command value of the peak current concerning 2nd Embodiment. The time chart explaining the calculation process of the corrected amount concerning the embodiment.

<First Embodiment>
Hereinafter, a first embodiment of a control device for an internal combustion engine will be described with reference to the drawings.

  In the intake passage 12 of the internal combustion engine 10 shown in FIG. 1, an air flow meter 14 for detecting the intake air amount and a throttle valve 16 for adjusting the intake air amount are arranged in this order from the upstream side. The intake passage 12 diverges for each cylinder of the internal combustion engine 10 downstream of the throttle valve 16, and is connected to the combustion chamber 26 of each cylinder defined by the cylinder 22 and the piston 24 via the intake port 18. . The intake port 18 and the combustion chamber 26 are brought into communication with each other when the intake valve 20 is opened. A crankshaft 32 is mechanically connected to the piston 24, and the crankshaft 32 can be connected to drive wheels.

  A fuel injection valve 28 and a spark plug 30 for injecting fuel are provided in the combustion chamber 26 of each cylinder. An air-fuel ratio sensor 38 for detecting the air-fuel ratio of the air-fuel mixture in the combustion chamber 26 is disposed in the exhaust passage 36 connected to the combustion chamber 26 of each cylinder. The combustion chamber 26 and the exhaust passage 36 are brought into communication with each other when the exhaust valve 34 is opened.

  The internal combustion engine 10 is provided with a fuel tank 40 that stores fuel injected from the fuel injection valve 28. The fuel tank 40 is provided with a feed pump 42 that pumps fuel from the inside.

  The high pressure fuel pump 44 further pressurizes the fuel pumped out by the feed pump 42 and discharges it to the high pressure fuel pipe 46. A fuel injection valve 28 for each cylinder is connected to the high-pressure fuel pipe 46.

  The ECU 60 is a control device that controls the internal combustion engine 10. The ECU 60 includes the air flow meter 14 and the air-fuel ratio sensor 38, an accelerator sensor 52 that detects the amount of operation of the accelerator pedal 50, an outside air temperature sensor 54 that detects the outside air temperature TO, a water temperature sensor 56 that detects the water temperature THW, and high-pressure fuel. A detection signal of a sensor such as a fuel pressure sensor 58 that detects the fuel pressure PF in the pipe 46 is captured. The ECU 60 controls the control amount (exhaust characteristics, torque, etc.) of the internal combustion engine 10 by operating actuators provided in each part of the engine such as the fuel injection valve 28 based on the detection results of these sensors. . At this time, the ECU 60 operates the high-pressure fuel pump 44 by the fuel pressure control processing unit 90a in order to control the control amount satisfactorily, whereby the injection pressure of the fuel injection valve 28 (the fuel pressure PF detected by the fuel pressure sensor 58). ) Is feedback controlled to the target fuel pressure. The fuel pressure control processing unit 90a variably sets the target fuel pressure.

  FIG. 2 schematically shows a partial configuration of the fuel injection valve 28 according to the present embodiment. As shown in FIG. 2, the fuel injection valve 28 has a hole in a part of the body 28 b and forms an injection port C. The injection port C is opened and closed by the nozzle needle 28c. The elastic force of the valve closing spring 28d is exerted on the nozzle needle 28c in the valve closing direction of the nozzle needle 28c. A coil 28a is provided on the valve opening direction side of the nozzle needle 28c with respect to the nozzle needle 28c, and a valve seat 28e for defining the maximum lift amount of the nozzle needle 28c is provided.

  In this configuration, when the coil 28a is energized, the nozzle needle 28c is attracted in the valve opening direction by the magnetic flux generated by the current flowing through the coil 28a. When the nozzle needle 28c is seated on the valve seat 28e, the nozzle needle 28c remains at the maximum lift amount without further increasing the lift amount.

In the present embodiment, a drive circuit for energizing the coil 28a is mounted in the ECU 60. FIG. 3 shows a part of the internal configuration of the ECU 60.
As shown in FIG. 3, the ECU 60 includes a booster circuit 62, and the booster circuit 62 is connected to a battery 48 outside the ECU 60. Specifically, the battery 48 is connected to one terminal of the booster coil 62a in the booster circuit 62, and the other terminal of the booster coil 62a is grounded via the chopper control switching element 62b. A diode 62c and a capacitor 62d are connected in parallel to the chopper control switching element 62b. The charging voltage Vc of the capacitor 62d is the voltage (output voltage) of the output terminal of the booster circuit 62. The output terminal of the booster circuit 62 is connected to the coil 28a via the output switching elements 64a and 64b. In the present embodiment, since the internal combustion engine 10 is assumed to have four cylinders, four coils 28a are described. Of the four coils 28a, two coils 28a are connected to the output switching element 64a, and the remaining two coils 28a are connected to the output switching element 64b. Here, the pair of coils 28a connected to the output switching element 64a are provided in the fuel injection valves 28 of the pair of cylinders that are most distant from each other.

  Each of the four coils 28a is connected to each of the cylinder selection switches 72 (1) to 72 (4). The cylinder selection switches 72 (1) and 72 (2) are grounded via a shunt resistor 74a, and the cylinder selection switches 72 (3) and 72 (4) are grounded via a shunt resistor 74b. Yes.

  Further, the terminal voltage of the battery 48 can be applied between the output switching element 64a and the coil 28a via the holding control switching element 66a and the diode 68a. The cathode of the diode 70a is connected between the output switching element 64a and the coil 28a, and the anode of the diode 70a is grounded.

  Similarly, the terminal voltage of the battery 48 can be applied between the output switching element 64b and the coil 28a via the holding control switching element 66b and the diode 68b. The cathode of the diode 70b is connected between the output switching element 64b and the coil 28a, and the anode of the diode 70b is grounded.

  The voltage drop of the shunt resistors 74a and 74b is taken into the current detector 76 as current I flowing through the coil 28a and converted into digital data. That is, the voltage drop of the shunt resistor 74a is output to the A / D converter 80a via the buffer circuit 78a. On the other hand, the voltage drop of the shunt resistor 74b is output to the A / D converter 80b via the buffer circuit 78b. The buffer circuits 78a and 78b convert the voltage drop of the shunt resistors 74a and 74b into voltage values that can be input to the A / D converters 80a and 80b. For example, the buffer circuits 78a and 78b may include a differential amplifier circuit. Good.

  The current I output from the current detection unit 76 is taken into the control unit 90. Based on the current I, the charging voltage Vc of the capacitor 62d, and the like, the control unit 90 includes a chopper control switching element 62b, output switching elements 64a and 64b, holding control switching elements 66a and 66b, and a cylinder selection switch 72 (1). Operate ~ 72 (4).

  The control unit 90 actually includes a chopper control switching element 62b, output switching elements 64a and 64b, holding control switching elements 66a and 66b, cylinder selection switches 72 (1) to 72 (4), and the like. You may isolate | separate into the drive circuit which operates, and the control circuit which operates a drive circuit. The control circuit may include a CPU and execute software processing, or may be an ASIC or the like that performs hardware processing.

  FIG. 4 shows a processing procedure of fuel injection control by operating the fuel injection valve 28. This process is executed by the control unit 90 and the current detection unit 76 every time a predetermined condition is satisfied. Note that this processing is actually processing for each cylinder, but here, processing related to the cylinder selected by the cylinder selection switch 72 (1) will be described.

  In this series of processes, the control unit 90 first acquires the fuel pressure PF detected by the fuel pressure sensor 58 (S10). Next, the control unit 90 calculates a command value (peak current command value Ipeak *) of the peak value of the current flowing through the coil 28a based on the fuel pressure PF (S12). Here, the peak current command value Ipeak * is set to a larger value as the fuel pressure PF is higher. Specifically, the control unit 90 sets the base value Ib of the peak current command value Ipeak * to a larger value as the fuel pressure PF is higher, and this base value Ib is a correction amount described later (may be zero). The peak current command value Ipeak * is corrected by the above.

  Subsequently, when the energization timing of the coil 28a is determined according to the fuel injection timing, the control unit 90 closes the output switching element 64a (S14). In order to energize the coil 28a, it is necessary to close the cylinder selection switch 72 (1), which is not shown in FIG. The process of closing the cylinder selection switch 72 (1) is assumed to be closed before the output switching element 64a is closed.

  Next, the current detection unit 76 converts the voltage drop of the shunt resistor 74a into digital data, and outputs it to the control unit 90 as a sampling value of the current I, which is acquired by the control unit 90 (S16). Then, the control unit 90 waits until the current I reaches the peak current command value Ipeak * (S18: NO). When determining that the current I has reached the peak current command value Ipeak * (S18: YES), the controller 90 opens the output switching element 64a (S20). And the control part 90 performs holding current control which controls so that the electric current I which flows through the coil 28a becomes the holding current command value Ik * (S22). The control unit 90 executes the holding current control until the injection end timing is reached (S24: NO). When determining that the injection end timing has come (S24: NO), the control unit 90 stops the holding current control (S26).

In addition, the control part 90 once complete | finishes this series of processes, when the process of step S26 is completed.
FIG. 5A shows the transition of the injection signal, FIG. 5B shows the transition of the operation state of the output switching element 64a, and FIG. 5C shows the operation state of the holding control switching element 66a. Shows the transition. FIG. 5 (d) shows the transition of the current I flowing through the coil 28a, FIG. 5 (e) shows the transition of the charging voltage Vc of the capacitor 62d, and FIG. 5 (f) shows the voltage applied to the coil 28a. FIG. 5G shows the transition of the lift amount of the nozzle needle 28c. Here, the injection signal is a signal for instructing the energization period of the coil 28a determined according to the fuel injection start timing and end timing of the fuel injection valve 28, and is generated and used in the controller 90. Note that the current I flowing through the coil 28a shown in FIG. 5D is the current I flowing through the coil 28a connected to the cylinder selection switch 72 (1).

  As shown in FIG. 5, when the injection signal rises at time t1, the output switching element 64a is closed. As a result, the loop circuit including the booster circuit 62, the output switching element 64a, the coil 28a, and the cylinder selection switch 72 (1) becomes a closed loop, and a current flows through the coil 28a selected by the cylinder selection switch 72 (1). The increasing speed of the current I flowing through the coil 28a gradually decreases until the time t1 when the valve opening current value Io is a current for opening the nozzle needle 28c. This is due to a decrease in the charging voltage Vc of the capacitor 62d. On the other hand, after reaching the valve opening current value Io, the increasing acceleration of the current I becomes positive. This is due to the electromotive force generated when the nozzle needle 28c starts to move toward the coil 28a.

  At time t3, when the output switching element 64a is opened due to the current I becoming the peak current command value Ipeak *, the output voltage of the booster circuit 62 is not applied to the coil 28a. The flowing current I decreases. At this time, the current flows through the loop circuit including the diode 70a, the coil 28a, the cylinder selection switch 72 (1), and the shunt resistor 74a by an electromotive force having a polarity that cancels the decrease in the current I flowing through the coil 28a. The current flowing through 28a does not become zero stepwise, but gradually decreases.

  Then, after time t4 when the current I flowing through the coil 28a falls below the holding current command value Ik *, holding current control is performed. That is, for example, when the holding control switching element 66a is closed over the period from time t4 to t5, the loop circuit including the battery 48, the holding control switching element 66a, the diode 68a, the coil 28a, and the shunt resistor 74a The terminal voltage of the battery 48 is applied to 28a, and the current flowing through the coil 28a gradually increases.

  In FIG. 5F, the output voltage of the booster circuit 62 is applied to the coil 28a over the period from time t1 to t3, and the terminal voltage of the battery 48 is applied intermittently during the period from time t4 to t6. It has been shown.

  In the present embodiment, when the current I flowing through the coil 28a becomes the peak current command value Ipeak *, the nozzle needle 28c of the fuel injection valve 28 has not reached full lift, and the lift amount is in the process of increasing. Therefore, when the holding current control period is long after the peak current command value Ipeak * is reached, the nozzle needle 28c reaches the full lift amount, so that the displacement of the nozzle needle 28c is stopped, and the full lift until the holding current control is terminated. The amount is maintained. On the other hand, when the holding current control period is short, the holding current control is terminated before the nozzle needle 28c reaches the full lift amount, and the nozzle needle 28c starts to be displaced in the valve closing direction before reaching the full lift amount. Become. FIG. 5 (g) shows this situation. When this so-called partial lift injection is executed, the range of the fuel injection amount that can be injected by the fuel injection valve 28 is expanded. However, the controllability of the fuel amount injected by the partial lift injection greatly depends on the control accuracy for controlling the peak value of the current I flowing through the coil 28a to the peak current command value Ipeak *.

  Here, as a factor that lowers the control accuracy to the peak current command value Ipeak *, there are detection errors caused by individual differences in the resistance values of the shunt resistors 74a and 74b, aging, and the like. Therefore, in the present embodiment, the detection error of the current I is compensated by correcting the peak current command value Ipeak * in the process of step S12 of FIG.

  FIG. 6 shows the procedure for calculating the correction amount of the peak current command value Ipeak * (base value Ib). This process is repeatedly executed by the control unit 90, for example, at a predetermined cycle. In this embodiment, the correction amount for the pair of coils 28a connected to the cylinder selection switches 72 (1) and 72 (2) and the cylinder selection switches 72 (3) and 72 (4) are connected. A correction amount for the pair of coils 28a is calculated. However, in the following, calculation of the correction amount for the pair of coils 28a connected to the cylinder selection switches 72 (1) and 72 (2) will be described as an example, and the cylinder selection switches 72 (3) and 72 (4) will be described. The calculation of the correction amount for the pair of coils 28a connected to) is the same and will be omitted.

  In this series of processes, the control unit 90 first determines whether or not the internal combustion engine 10 is being started (S30). This process is for determining whether one of the conditions permitting the calculation of the correction amount of the peak current command value Ipeak * is satisfied. Then, when determining that it is at the time of starting, the control unit 90 obtains the water temperature THW and the outside air temperature TO, assuming that one of the conditions for permitting calculation of the correction amount is satisfied (S32). Then, the control unit 90 determines whether or not the absolute value of the difference between the water temperature THW and the outside air temperature TO is equal to or less than a predetermined value Δth (S34). This process is for determining whether another condition permitting calculation of the correction amount is satisfied. Here, the reason that the absolute value of the difference between the water temperature THW and the outside air temperature TO is equal to or less than the predetermined value Δth is that the change rate of the current flowing through the coil 28a depends on the temperature of the coil 28a. . By providing the above condition, it can be set as a condition for permitting calculation of the correction amount that the temperature of the coil 28a is normal temperature. That is, when the internal combustion engine 10 is operated, the temperature of the coil 28a rises. In this case, the water temperature THW also rises and becomes higher than the outside air temperature TO. When the internal combustion engine 10 is started again at a short time after the stop, the internal combustion engine 10 has not reached a thermal equilibrium state with the outside air, so the coil 28a and the water temperature THW are higher than the outside air temperature TO. Get higher.

  When determining that the absolute value of the difference between the water temperature THW and the outside air temperature TO is equal to or less than the predetermined value Δth (S34: YES), the controller 90 waits until the output switching element 64a is closed (S36: NO). ). Then, when the output switching element 64a is closed (S36: YES), the control unit 90 starts a time measurement process (S38). Then, the control unit 90 monitors that the current I becomes the peak current command value Ipeak * (S40: NO), and determines that the current I has reached the peak current command value Ipeak * (S40: YES), the peak current arrival time Tp is detected (S42). The peak current arrival time Tp is the time required from when the output switching element 64a is closed until the current I reaches the peak current command value Ipeak *. This process is executed based on the timing process in step S38.

  Next, the controller 90 calculates a reference time Tpr required to reach the peak current command value Ipeak * based on the peak current command value Ipeak * (S44). Here, the peak current arrival time Tp is calculated to be longer as the peak current command value Ipeak * is larger. The reference time Tpr may be obtained by measuring in advance using a detection device in which the current detection error can be ignored when the coil 28a is at room temperature.

  Next, the control unit 90 determines whether or not the peak current arrival time Tp is less than or equal to the reference time Tpr (S46). When determining that the peak current arrival time Tp is equal to or less than the reference time Tpr (S46: YES), the controller 90 calculates an increase correction amount for the peak current command value Ipeak * (S48). This is in view of the fact that, when the peak current arrival time Tp is less than the reference time Tpr, it is considered that the current I output from the current detection unit 76 includes an error that is larger than the actual current. Here, the increase correction amount is calculated as a larger value as the amount that the peak current arrival time Tp falls below the reference time Tpr is larger. The increase correction amount is set to zero when the peak current arrival time Tp matches the reference time Tpr. Incidentally, the increase correction amount may be set to zero when the amount in which the peak current arrival time Tp falls below the reference time Tpr is equal to or less than a specified amount (> 0).

  On the other hand, when determining that the peak current arrival time Tp exceeds the reference time Tpr (S46: NO), the controller 90 calculates a decrease correction amount of the peak current command value Ipeak * (S50). This is because it is considered that when the peak current arrival time Tp exceeds the reference time Tpr, the current I output from the current detection unit 76 includes an error that is smaller than the actual current. Here, the decrease correction amount is calculated as a larger value as the amount by which the peak current arrival time Tp exceeds the reference time Tpr is larger. The decrease correction amount may be zero when the amount of the peak current arrival time Tp exceeding the reference time Tpr is equal to or less than the specified amount.

  In addition, the control part 90 once complete | finishes this series of processes, when the process of step S48, S50 is completed, or when negative determination is made in step S30, S34. In the present embodiment, once the correction amount is calculated, the correction amount is not calculated until the travel permission switch of the vehicle such as an ignition switch is once turned off and then turned on again.

Here, the operation of the present embodiment will be described.
When the internal combustion engine 10 is started, when a predetermined condition is satisfied, the peak current arrival time Tp is detected, and based on this, the correction amount of the peak current command value Ipeak * is calculated. After the correction amount is calculated, the correction amount is used when calculating the peak current command value Ipeak * in the process of step S12 shown in FIG. That is, after calculating the base value Ib of the peak current command value Ipeak * based on the fuel pressure PF, the control unit 90 corrects the base value Ib according to the correction amount, and sets this as the peak current command value Ipeak *. Here, the correction amount is applied to the coil 28a connected to the cylinder selection switches 72 (3) and 72 (4) when the coil 28a connected to the cylinder selection switches 72 (1) and 72 (2) is energized. What is different from when energized is used. Therefore, the peak current command value Ipeak * is energized to the coil 28a connected to the cylinder selection switches 72 (1) and 72 (2) even if the base value Ib calculated based on the fuel pressure PF is the same. This may be different from when the coil 28a connected to the cylinder selection switches 72 (3) and 72 (4) is energized.

  Incidentally, in step S12 of FIG. 4 when the determination is affirmative in step S34 of FIG. 6 and the correction amount is calculated, the correction amount may be the previous correction amount. In this case, the correction amount calculated in step S48 or step S50 is added to the previous correction amount.

According to the present embodiment described above, the following effects can be obtained.
(1) The controller 90 calculates an increase correction amount or a decrease correction amount of the peak current command value Ipeak * depending on whether or not the peak current arrival time Tp is equal to or less than the reference time Tpr. As a result, the peak current command value Ipeak * is an appropriate value for controlling the current that actually flows through the coil 28a to the peak current command value Ipeak * (base value Ib) before correction based on the current I having a detection error. It can be.

  (2) The larger the absolute value of the difference between the peak current arrival time Tp and the reference time Tpr, the larger the absolute value of the correction amount. Thus, an appropriate correction amount can be calculated by a single process for controlling the current actually flowing through the coil 28a to the peak current command value Ipeak * before correction based on the current I having a detection error. .

  (3) The correction amount is calculated on the condition that the absolute value of the difference between the water temperature THW and the outside air temperature TO is not more than a predetermined value Δth. Thereby, it is possible to suppress a situation in which the correction amount is calculated when the temperature of the coil 28a greatly deviates from the temperature assumed in the setting of the reference time Tpr.

<Second Embodiment>
Hereinafter, a second embodiment of the control device for an internal combustion engine will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 7 shows the procedure for calculating the correction amount of the peak current command value Ipeak *. This process is repeatedly executed by the control unit 90, for example, at a predetermined cycle. In this embodiment, the correction amount for the pair of coils 28a connected to the cylinder selection switches 72 (1) and 72 (2) and the cylinder selection switches 72 (3) and 72 (4) are connected. A correction amount for the pair of coils 28a is calculated. However, in the following, calculation of the correction amount for the pair of coils 28a connected to the cylinder selection switches 72 (1) and 72 (2) will be described as an example, and the cylinder selection switches 72 (3) and 72 (4) will be described. The calculation of the correction amount for the pair of coils 28a connected to) is the same and will be omitted.

  In this series of processes, the control unit 90 first calculates the valve opening current value Io based on the fuel pressure PF (S60). Here, the control unit 90 calculates the valve opening current value Io to a larger value as the fuel pressure PF is higher. Next, the control unit 90 waits until the output switching element 64a is closed (S62: NO). When determining that the output switching element 64a is closed (S62: YES), the control unit 90 starts a time measurement process (S64). Then, the control unit 90 stands by until the current I becomes the valve opening current value Io (S66: NO). When the controller 90 determines that the current I has reached the valve opening current value Io (S66: YES), it is necessary until the current I becomes the valve opening current value Io after the output switching element 64a is closed. The valve opening current arrival time To, which is the measured time, is detected (S68). This process is executed based on the timing process started in step S64.

  Next, the control unit 90 waits until the current I reaches the peak current command value Ipeak * (S70: NO). When determining that the current I has reached the peak current command value Ipeak * (S70: YES), the control unit 90 calculates the peak current arrival time Tp (S72). This process is executed based on the timing process started in step S64.

  Next, the control unit 90 calculates an arrival time ratio R that is a value obtained by dividing the peak current arrival time Tp by the valve opening current arrival time To (S74). Next, the control unit 90 calculates a reference value Rr for the arrival time ratio R based on the fuel pressure PF (S76). This is because the valve opening current arrival time To and the peak current arrival time Tp are measured in advance using a detection device in which the current detection error can be ignored, and the relationship between the fuel pressure PF and the reference value Rr is determined based on these measurement values. This can be realized by creating a map in advance and storing it in the control unit 90.

  Then, the control unit 90 determines whether or not the arrival time ratio R is greater than or equal to the reference value Rr (S78). When determining that the arrival time ratio R is greater than or equal to the reference value Rr (S78: YES), the control unit 90 calculates an increase correction amount of the peak current command value Ipeak *. This is because when the arrival time ratio R is larger than the reference value Rr, the current I includes an error that is larger than the actual current. Hereinafter, this will be described with reference to FIG.

  FIG. 8 shows the detection results of the valve opening current arrival time To and the peak current arrival time Tp when the current I includes an error that takes a value larger than the actual current. In this case, the valve opening current arrival time To is shorter than the time required for the actual current to reach the valve opening current value Io, and the peak current arrival time Tp is the actual current reaching the peak current command value Ipeak *. Shorter than the time to do.

  Here, the actual current increase rate is greater in the vicinity of the peak current command value Ipeak * than in the vicinity of the valve opening current value Io. For this reason, when the difference between the current I and the actual current is regarded as a constant value ERR, the amount ΔTo that the valve opening current arrival time To is shorter than the actual time is smaller than the peak current arrival time Tp than the actual time. Greater than the amount ΔTp.

Here, the reference value Rr is as follows.
Rr = (Tp + ΔTp) / (To + ΔTo)
If the amount ΔTp is small, the reference value Rr can be approximated as “Tp / (To + ΔTo)”. This value is smaller than the arrival time ratio R.

  Returning to FIG. 7, in step S <b> 80, the control unit 90 calculates the increase correction amount to a larger value as the value obtained by subtracting the reference value Rr from the arrival time ratio R is larger. However, the controller 90 sets the correction amount to zero when the difference between the arrival time ratio R and the reference value Rr is zero. The increase correction amount may be set to zero even when the value obtained by subtracting the reference value Rr from the arrival time ratio R is equal to or less than the specified value.

  On the other hand, when determining that the arrival time ratio R is smaller than the reference value Rr (S78: NO), the control unit 90 calculates a decrease correction amount of the peak current command value Ipeak * (S82). Specifically, the control unit 90 calculates the decrease correction amount to a larger value as the value obtained by subtracting the arrival time ratio R from the reference value Rr is larger. If the value obtained by subtracting the arrival time ratio R from the reference value Rr is equal to or less than the specified value, the decrease correction amount may be set to zero.

  In addition, the control part 90 once complete | finishes this series of processes, when the process of step S80, S82 is completed. By the way, once the correction amount is calculated, the correction amount is not calculated until the travel permission switch of the vehicle such as an ignition switch is once turned off and then turned on again.

Here, the operation of the present embodiment will be described.
The controller 90 detects the valve opening current arrival time To and the peak current arrival time Tp, and calculates the arrival time ratio R. Then, the control unit 90 calculates the correction amount of the peak current command value Ipeak * based on the difference between the arrival time ratio R and the reference value Rr. Then, after calculating the correction amount, the control unit 90 uses the correction amount in calculating the peak current command value Ipeak * in the process of step S12 shown in FIG. That is, after calculating the base value Ib of the peak current command value Ipeak * based on the fuel pressure PF, the control unit 90 corrects the base value Ib according to the correction amount, and sets this as the peak current command value Ipeak *. Here, the correction amount is applied to the coil 28a connected to the cylinder selection switches 72 (3) and 72 (4) when the coil 28a connected to the cylinder selection switches 72 (1) and 72 (2) is energized. What is different from when energized is used.

  Incidentally, in the process of step S12 in FIG. 4 when the correction amount is calculated by the process shown in FIG. 7, the correction amount may be the previous correction amount. In this case, the correction amount calculated in step S80 or step S82 is added to the previous correction amount.

According to the embodiment described above, the following effects can be obtained.
(4) By comparing the arrival time ratio R with the reference value Rr, the reference time for the actual current to reach the peak current command value Ipeak * and the peak current arrival time Tp were compared. Here, the magnitude relationship between the arrival time ratio R and the reference value Rr and the magnitude relationship between the current I and the actual current do not depend on the temperature of the coil 28a. Therefore, according to the present embodiment, even if the rate of change of the current flowing through the coil 28a varies depending on the temperature of the coil 28a, the reference time when the actual current reaches the peak current command value Ipeak * and the peak current arrival time Tp Can be compared with high accuracy.

  (5) Each time one fuel injection is performed, the capacitor 62d having a capacitance that needs to be charged is adopted, and the charging voltage Vc is applied. As the fuel injection valve 28, the applied voltage of the coil 28a In the case where is fixed, the one in which the increase acceleration of the current of the coil 28a after the valve opening becomes positive is used. Thus, by comparing the arrival time ratio R and the reference value Rr with each other, the reference time for the actual current to reach the peak current command value Ipeak * and the peak current arrival time Tp are compared with each other with high accuracy. Can do.

<Other embodiments>
In addition, you may change at least 1 of each matter of the said embodiment as follows. In the following, there is a portion that illustrates the correspondence relationship between the items described in the column of “Means for Solving the Problem” and the items in the above embodiment by reference numerals, etc. There is no intention to limit. The power source and high voltage power source in the column “Means for Solving Problems” correspond to the booster circuit 62, and the low voltage power source corresponds to the battery 48. The acquisition processing unit corresponds to the process of step S16, the application processing unit corresponds to the process of step S14, the stop processing unit corresponds to the process of step S20, and the peak current arrival time detection processing unit This corresponds to the processing of steps S40, S42, S64, and S72. The valve opening current arrival time detection processing unit corresponds to the processing of steps S64 to S68, and the command value setting processing unit corresponds to the processing of step S12.

・ "About arrival time ratio calculation processing unit (S74)"
The arrival time ratio R is not limited to a value obtained by dividing the peak current arrival time Tp by the valve opening current arrival time To, but is a value (To / Tp) obtained by dividing the valve opening current arrival time To by the peak current arrival time Tp. Also good.

・ About the comparison processing unit (S78)
In FIG. 7, when the arrival time ratio R is greater than or equal to the reference value Rr, the peak current command value Ipeak * is increased and corrected, but the present invention is not limited to this. For example, when the arrival time ratio R is set to “To / Tp” as described in the column “About the arrival time ratio calculation processing unit”, the peak current command value is set when the arrival time ratio R is equal to or greater than the reference value Rr. What is necessary is just to carry out decrease correction of Ipeak *.

・ "Reference time setting processing unit (S44)"
The present invention is not limited to the calculation of the reference time Tpr based on the peak current command value Ipeak *. For example, considering that the peak current command value Ipeak * is calculated based on the fuel pressure PF, the reference time Tpr may be calculated based on the fuel pressure PF.

・ "Calculation process of reference value Rr"
It is not limited to calculating the reference value Rr based on the fuel pressure PF. For example, considering that the peak current command value Ipeak * is calculated based on the fuel pressure PF, the reference value Rr may be calculated based on the peak current command value Ipeak *.

・ "Calculation processing of valve opening current value Io"
The valve opening current value calculation processing unit (S60) that calculates the valve opening current value Io based on the fuel pressure PF is not essential. For example, if the pressure in the high-pressure fuel pipe 46 is not variably controlled, or even if variably controlled, the variation range of the pressure hardly changes the valve opening current value Io, the valve opening current value Io is set to the fuel pressure PF or the like. It is good also as a default value, without calculating based on.

"About correction processing unit (S46 to S50; S78 to S82)"
In the first embodiment (FIG. 6), the increase correction amount and the decrease correction amount of the peak current command value Ipeak * are variably set based on the difference between the reference time Tpr and the peak current arrival time Tp. Absent. For example, the increase correction or the decrease correction of the peak current command value Ipeak * may be executed with a correction amount whose absolute value is a predetermined amount. Even in this case, the predetermined amount is set to a relatively small value, and the processing shown in FIG. 6 is repeated a plurality of times at the start, so that the peak current command value Ipeak * is a value according to the above embodiment. Can be corrected. In other words, since the integrated amount of the correction amount calculated each time can be equivalent to the correction amount of the above embodiment, the base value Ib may be corrected by the integrated amount.

  In the second embodiment (FIG. 7), the increase correction amount and the decrease correction amount of the peak current command value Ipeak * are variably set based on the difference between the arrival time ratio R and the reference value Rr. However, the present invention is not limited to this. . For example, the increase correction or the decrease correction of the peak current command value Ipeak * may be executed with a correction amount whose absolute value is a predetermined amount. Even in this case, the predetermined amount is set to a relatively small value, and the processing shown in FIG. 7 is repeated a plurality of times to correct the peak current command value Ipeak * to a value according to the above embodiment. be able to.

・ About correction target by correction amount
In the above embodiment, the correction amount is calculated for each cylinder in which the current flowing through the coil 28a is detected by the same one of the shunt resistors 74a and 74b. However, the present invention is not limited to this. For example, the tolerance is severely limited for the shunt resistors 74a and 74b, while the detection error (voltage conversion error) is significant for the buffer circuit 78a, and a single buffer circuit 78a is provided for all cylinders. In the case of sharing, the peak current command value Ipeak * of all cylinders may be corrected with a single correction amount.

・ "Execution conditions for correction amount calculation"
In the first embodiment, the process of step S34 is deleted, and instead, the temperature of the coil 28a is estimated according to the change rate of the current flowing through the coil 28a when the output voltage of the booster circuit 62 is applied to the coil 28a. Then, the reference time Tpr may be calculated based on the estimated temperature and fuel pressure PF. This can be realized by storing in advance in the control unit 90 a map that defines the relationship between the rate of change of the current flowing through the coil 28a and the temperature of the coil 28a.

  In the second embodiment, a condition that is positively determined in the process of step S34 in FIG. 6 may be added to the execution condition of the correction amount calculation process. Further, for example, in the second embodiment, the start condition may be the start condition.

・ "Capacitor charging process"
In the above embodiment, when the energization process for the coil 28a is completed, the capacitor 62d is charged every time prior to the next energization process. However, the present invention is not limited to this.

・ About the fuel injection valve
As shown in FIG. 2, the member that operates together with the nozzle needle 28c and is attracted to the coil 28a side is not limited to the member that is not inserted into the coil 28a. For example, it is not restricted to the structure which the electromotive force which increases the electric current which flows through the coil 28a at the time of valve opening of the nozzle needle 28c produces. When the electromotive force is not generated, it is considered that the rate of increase in current near the peak current command value Ipeak * is smaller than the rate of increase in current I near the valve opening. In that case, if a positive determination is made in the process of step S78 of FIG. 7, the process of step S82 is executed, and if a negative determination is made in the process of step S78, the process of step S80 may be executed.

Further, the fuel is not limited to being injected into the combustion chamber, and for example, fuel may be injected into the intake port.
・ "About the coil energizer"
The present invention is not limited to applying the terminal voltage of the battery 48 to the coil 28a after applying the boosted voltage by the booster circuit 62 (charge voltage Vc of the capacitor 62d) to the coil 28a. For example, after the boosted voltage from the booster circuit 62 is applied to the coil 28a and the current flowing through the coil 28a is set to the peak current command value Ipeak *, the boosted voltage of the booster circuit 62 is intermittently applied to flow through the coil 28a. I may be controlled to the holding current command value Ik *. For example, after the terminal voltage of the battery 48 is applied to the coil 28a and the current flowing through the coil 28a is set to the peak current command value Ipeak *, the terminal voltage is intermittently applied and the current I flowing through the coil 28a is held. It may be controlled to the command value Ik *.

  However, the process of intermittently applying a voltage to the coil 28a to control the holding current command value Ik * is not essential.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 12 ... Intake passage, 14 ... Air flow meter, 16 ... Throttle valve, 18 ... Intake port, 20 ... Intake valve, 22 ... Cylinder, 24 ... Piston, 26 ... Combustion chamber, 28 ... Fuel injection valve, 28a ... Coil, 28b ... Body, 28c ... Nozzle needle, 28d ... Valve closing spring, 28e ... Valve seat, 30 ... Spark plug, 32 ... Crankshaft, 34 ... Exhaust valve, 36 ... Exhaust passage, 38 ... Air-fuel ratio sensor, DESCRIPTION OF SYMBOLS 40 ... Fuel tank, 42 ... Feed pump, 44 ... High pressure fuel pump, 46 ... High pressure fuel piping, 48 ... Battery, 50 ... Accelerator pedal, 52 ... Accelerator sensor, 54 ... Outside temperature sensor, 56 ... Water temperature sensor, 58 ... Fuel pressure Sensor 60 ... ECU 62 ... Booster circuit 62a ... Booster coil 62b ... Chopper control switching element 62c ... Die 62d ... capacitor, 64a, 64b ... output switching element, 66a, 66b ... holding control switching element, 68a, 68b, 70a, 70b ... diode, 72 ... cylinder selection switch, 74a ... shunt resistor, 74b ... shunt Resistance, 76 ... Current detection unit, 78a ... Buffer circuit, 78b ... Buffer circuit, 80a, 80b ... A / D converter, 90 ... Control unit, 90a ... Fuel pressure control processing unit.

Claims (6)

An internal combustion engine having a fuel injection valve that opens by energizing the coil is controlled,
An acquisition processing unit for acquiring a current flowing in the coil;
An application processing unit for applying a power supply voltage to the coil;
A command value setting processing unit for setting the peak current command value to a larger value as the injection pressure of the fuel injection valve is higher ;
A stop processing unit that stops application of the voltage of the power source when the current acquired by the acquisition processing unit reaches the peak current command value when the voltage of the power source is applied to the coil by the application processing unit. When,
A peak current arrival time detection processing unit that detects a peak current arrival time that is a time required for the current acquired by the acquisition processing unit to reach the peak current command value after the voltage of the power source is applied to the coil; ,
When the detected peak current arrival time is shorter than a reference time required for the current flowing through the coil to reach the peak current command value, the peak current command value is increased and corrected. A control apparatus for an internal combustion engine, comprising: a correction processing unit that reduces and corrects the peak current command value when the peak current command value is long. A valve opening current value calculation processing unit that calculates a valve opening current value that is a current that flows through the coil when the fuel injection valve switches from a valve closing state to a valve opening state based on the injection pressure;
The correction processing unit
A valve opening current arrival time detection process for detecting a valve opening current arrival time, which is a time required for the current acquired by the acquisition processing unit to reach the valve opening current value after the voltage of the power source is applied to the coil. And
An arrival time ratio calculation processing unit that calculates an arrival time ratio that is a ratio of the valve opening current arrival time and the peak current arrival time;
The arrival time ratio calculated by the arrival time ratio calculation processing unit, the time required for the current flowing through the coil to become the valve opening current value, and the time required for the current flowing through the coil to reach the peak current command value The control apparatus for an internal combustion engine according to claim 1, further comprising a comparison processing unit that compares the detected peak current arrival time with a reference time by comparing a magnitude with a reference value of a ratio to a required time . Control apparatus for an internal combustion engine according to claim 2, wherein the injection pressure of the previous SL fuel injection valve comprises a fuel pressure control unit for variably controlling.   3. The fuel injection valve has a positive increase in current flowing through the coil when the fuel injection valve is switched from a closed state to an open state even when the voltage applied to the coil is the same. Or the control apparatus of the internal combustion engine of 3 or 3. A fuel pressure control processing unit that variably controls the injection pressure of the fuel injection valve;
A reference time setting processing unit which is either a process for setting the reference time to be longer as the injection pressure is higher, or a process for setting the reference time to be longer as the peak current command value is larger. ,
2. The control device for an internal combustion engine according to claim 1, wherein the correction processing unit corrects the peak current command value based on a magnitude comparison between the detected peak current arrival time and the set reference time. The power supply is a booster circuit that applies a boosted voltage obtained by boosting a terminal voltage of a battery to the coil ,
The coil can be applied with a terminal voltage of the battery having a voltage lower than the boosted voltage,
Application of the boosted voltage of the booster circuit is stopped by the stop processing unit, and the terminal voltage of the battery is intermittently applied to the coil during the fuel injection period by the fuel injection valve, thereby flowing to the coil. The control device for an internal combustion engine according to any one of claims 1 to 5, further comprising a holding current processing unit that controls a current to a predetermined holding current value smaller than the peak current command value.