JP6398683B2 - High pressure injector controller - Google Patents

Description

  The present invention relates to a high-pressure injector control device that controls driving of an injector.

  As this type of high-pressure injector control device, for example, there is a device described in Patent Document 1. The high voltage injector control device described in Patent Document 1 has a booster circuit that boosts the battery voltage. When injecting fuel from an injector, the high-pressure injector control device first opens the injector by supplying a voltage boosted by a booster circuit to the injector. Thereafter, the high pressure injector control device maintains the injector in a valve-opened state by maintaining the current supplied to the injector at a constant value. Further, the high pressure injector control device stops the injection by stopping the current supply to the injector when the injection setting time has elapsed from the time when the injector is opened, and stops the injection.

JP 2008-190388 A

  By the way, in the high voltage injector control device described in Patent Document 1, there are individual differences such as manufacturing tolerances, temperature tolerances, durability tolerances, etc., in elements constituting the booster circuit. Variations in the boosting capability of the booster circuit occur due to such individual differences between elements. In the high-pressure injector control device, since the capacitor of the booster circuit is discharged and boosted at the same time during fuel injection, if the boosting capability of the booster circuit varies, the supply current of the fuel injector varies. This causes a variation in the injection amount.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a high-pressure injector control device capable of suppressing variations in injection amount.

In order to solve the above problems, a high voltage injector control device (1) for controlling driving of the injectors (5, 6) includes a booster circuit (30) for storing energy in a capacitor (C10) based on a voltage supplied from a battery. The boosting time detecting means (20) for detecting the boosting time required for the voltage of the capacitor to change from the first voltage value to the second voltage value higher than the first voltage value , and stored in the capacitor during the boosting time based on the amount of energy, and boosting capability calculating means for exiting calculate the boosting capability indicating the amount of energy stored per unit in capacitor time (21), the injection time correction means for correcting the injection setting time of the injector based on the boosting ability ( 22). The injection time correction means has a reference injection setting time corresponding to a preset reference boosting capability in advance, and when the boosting capability is higher than the reference boosting capability, it is shorter than the reference injection setting time. The injection setting time is corrected, and when the boosting capability is lower than the reference boosting capability, the injection setting time is corrected so as to be longer than the reference injection setting time.

  According to this configuration, since the injection setting time of the injector is adjusted based on the individual boosting capability of the booster circuit, variations in the injection amount can be suppressed.

  According to the present invention, it is possible to suppress variations in the injection amount.

The circuit diagram which shows the structure about 1st Embodiment of a high voltage | pressure injector control apparatus. (A), (b) is a timing chart which shows transition of switch current I10 and capacitor | condenser current I11 about the high voltage | pressure injector control apparatus of 1st Embodiment. (A)-(f) is a timing chart which shows transition of an injection signal, each operation | movement of transistor T20, T21, T23, injector current I20, and the injection amount of an injector about the high voltage | pressure injector control apparatus of 1st Embodiment. The timing chart which shows transition of the capacitor voltage Vc about the high voltage | pressure injector control apparatus of 1st Embodiment. (A)-(c) is a timing chart which shows transition of the injection signal by the high voltage | pressure injector control apparatus of 1st Embodiment, injector current I20, and the capacitor voltage Vc. The circuit diagram which shows the structure of the boost voltage detection part about the high voltage | pressure injector control apparatus of 1st Embodiment. The block diagram which shows the structure of the microcomputer about the high voltage | pressure injector control apparatus of 1st Embodiment. The graph which shows transition of the capacitor | condenser voltage Vc about the high voltage | pressure injector control apparatus of 1st Embodiment. The flowchart which shows the procedure of the process performed by the high voltage | pressure injector control apparatus of 1st Embodiment. The flowchart which shows the procedure of the process performed by the high voltage | pressure injector control apparatus of the modification of 1st Embodiment. The block diagram which shows the structure of the microcomputer about 2nd Embodiment of a high voltage | pressure injector control apparatus. The flowchart which shows the procedure of the process performed by the high voltage | pressure injector control apparatus of 2nd Embodiment. The block diagram which shows the structure of the microcomputer about 3rd Embodiment of a high voltage | pressure injector control apparatus. The flowchart which shows the procedure of the process performed by the high voltage | pressure injector control apparatus of 3rd Embodiment.

<First Embodiment>
Hereinafter, a first embodiment of the high-pressure injector control device will be described. The high-pressure injector control device of this embodiment is mounted on a direct injection type internal combustion engine. In an in-cylinder direct injection internal combustion engine, high-pressure fuel is directly supplied to each cylinder as the injector is driven.

  As shown in FIG. 1, the high-pressure injector control device 1 according to this embodiment includes an electronic control unit (ECU) including a known microcomputer 2 including a CPU, various memories, and the like. Hereinafter, the high pressure injector control device 1 is simply abbreviated as “ECU1”, and the microcomputer 2 is abbreviated as “microcomputer 2”.

  In addition to the microcomputer 2, the ECU 1 includes a drive circuit 3 for driving the injectors 5 and 6, and an injector control circuit 4 for controlling the drive of the injectors 5 and 6 via the drive circuit 3. In FIG. 1, for convenience, only two of the plurality of injectors corresponding to each cylinder are illustrated.

  The injectors 5 and 6 are normally closed solenoid valves and are provided with solenoids 50 and 60, respectively. The high potential side terminals of the solenoids 50 and 60 are connected to the terminals INJ1P and INJ2P of the ECU 1, respectively. The low potential side terminals of the solenoids 50 and 60 are connected to terminals INJ1M and INJ2M of the ECU 1, respectively. When the solenoids 50 and 60 are energized by the drive circuit 3, a valve body (not shown) moves to the valve opening position against the urging force of the return spring, and fuel injection is performed. When the energization of the solenoids 50 and 60 is interrupted, the valve body returns to the original closed position, and fuel injection is stopped.

  The drive circuit 3 includes a booster circuit 30, transistors T20 to T23, diodes D20 and D21, and a current detection resistor R20.

  The booster circuit 30 includes an inductor L10, a transistor T10, a capacitor C10, current detection resistors R10 and R11, a diode D10, and a booster control circuit 31.

  One end of the inductor L10 is connected to a battery power line (battery voltage VB) as an in-vehicle power source. The other end of the inductor L10 is connected to the drain terminal of the transistor T10. The source terminal of the transistor T10 is connected to the ground (ground) via the current detection resistor R10. The current detection resistor R10 is for detecting the switch current I10 flowing through the transistor T10.

  The gate terminal of the transistor T10 is connected to the boost control circuit 31. That is, the transistor T10 is turned on / off according to the output of the boost control circuit 31. One end of the capacitor C10 is connected between the inductor L10 and the transistor T10 via a backflow preventing diode D10. The other end of the capacitor C10 is grounded via a current detection resistor R11. The current detection resistor R11 is for detecting the capacitor current I11 flowing through the capacitor C10.

  The boost control circuit 31 turns on / off the transistor T10 based on the switch current I10 detected through the current detection resistor R10 and the capacitor current I11 detected through the current detection resistor R11. Specifically, as shown in FIGS. 2A and 2B, after the boost control circuit 31 turns on the transistor T10 at time t10, the switch current I10 reaches the preset threshold current Ith1 at time t11. Then, at time t12 immediately after that, the transistor T10 is turned off. At this time, the electric energy stored in the inductor L10 from the time t10 when the transistor T10 is turned on to the time t12 when the transistor T10 is turned off is stored in the capacitor C10 via the diode D10.

  The capacitor current I11 rises at time t12 when the accumulation of electrical energy in the capacitor C10 starts, and then gradually decreases. When the capacitor current I11 becomes equal to or less than the preset threshold current Ith2 at time t13, the boost control circuit 31 turns on the transistor T10 again at time t14 immediately after that. As a result, the switch current I10 rises again. Thereafter, the boost control circuit 31 repeats on / off of the transistor T10 based on the switch current I10 and the capacitor current I11. As a result, electric energy is accumulated in the capacitor C10. Hereinafter, the voltage of the capacitor C10, that is, the boosted voltage of the booster circuit 30 is referred to as a capacitor voltage Vc.

  The transistor T20 is provided between the capacitor C10 of the booster circuit 30 and the connection point P1 of the terminals INJ1P and INJ2P of the drive circuit 3. That is, when the transistor T20 is turned on, the electric energy stored in the capacitor C10 is supplied to the solenoids 50 and 60. Due to the energy release of the capacitor C10, current is supplied to the solenoids 50 and 60, and the injectors 5 and 6 are opened.

  The transistor T21 is provided between the terminal INJ1M of the drive circuit 3 and the ground. The transistor T22 is provided between the terminal INJ2M of the drive circuit 3 and the ground. By turning on either the transistor T21 or the transistor T22, a current can be supplied to one of the solenoids 50 and 60. That is, it is possible to select which of the injectors 5 and 6 is to be opened.

  The current detection resistor R20 is provided between the transistor T21 and the ground. The current detection resistor R20 is for detecting the injector current I20 flowing through the solenoids 50 and 60.

  The terminals INJ1P and INJ2P of the drive circuit 3 are connected to the battery power supply line via the diode D20 and the transistor T23. Therefore, by turning on the transistor T23, a constant current can be supplied from the battery power supply line to the solenoids 50 and 60. The diode D21 is a feedback diode, and the current flowing through the solenoids 50 and 60 when the transistor T22 is turned off is circulated through the diode D21.

  The microcomputer 2 generates an injection signal for each cylinder based on engine operation information detected by various sensors such as the engine speed Ne, the accelerator opening degree ACC, and the engine water temperature THW, and the generated injection signal is sent to the injector control circuit 4. Output.

  The injector control circuit 4 drives the injectors 5 and 6 by turning on / off the transistors T20 to T23 based on the injection signal transmitted from the microcomputer 2.

  Next, drive control of the injectors 5 and 6 by the injector control circuit 4 will be described. Hereinafter, for convenience, drive control of the injector 5 will be described as a representative.

  As shown in FIGS. 3A, 3B, and 3D, the injector control circuit 4 turns on the transistor T21 at the time t20 when the signal level of the injection signal switches from the low level to the high level, and the transistor T20. Turn on. As a result, as shown in FIG. 3E, current supply from the booster circuit 30 to the solenoid 50 is started.

Thereafter, the injector control circuit 4 monitors the injector current I20, the injector current I20 reaches the peak current setting value Ip at time t2 2, turning off the transistor T20. The peak current set value Ip is set to a value larger than the valve opening threshold current Io necessary for opening the injector 5. That is, at time t21 when the injector current I20 exceeds the valve opening threshold current Io, the injector 5 is opened and fuel injection is started. After turning off the transistor T20 at time t22, the injector control circuit 4 repeatedly turns on and off the transistor T23 as shown in FIG. 3C, thereby maintaining the valve open state of the injector 5.

  Specifically, when the injector current I20 reaches the hold current lower limit IL while the transistor T20 is turned off, the injector control circuit 4 turns on the transistor T23, thereby supplying current from the battery power supply line to the solenoid 50. Supply. The hold current lower limit value IL is set to a value larger than the valve closing threshold current Ic at which the injector 5 is closed. Further, when the injector current I20 reaches the hold current upper limit value IH while the transistor T20 is turned on, the injector control circuit 4 stops the current supply to the solenoid 50 by turning off the transistor T23. . The hold current upper limit value IH is set to a value smaller than the valve opening threshold current Io. The injector control circuit 4 keeps the injector 5 open by repeatedly turning on and off the transistor T23 while the signal level of the injection signal is high.

  As shown in FIGS. 3A, 3C, and 3D, when the signal level of the injection signal is switched from the high level to the low level at time t23, the injector control circuit 4 causes both the transistor T21 and the transistor T23 to be turned on. Turn off. As a result, the injector 5 is closed at time t24 when the injector current I20 becomes less than the valve closing threshold current Ic.

  In the present embodiment, the period during which the signal level of the injection signal is set to the high level corresponds to the injection setting time H of the injectors 5 and 6. Since the injector 5 injects fuel from time t21 when the switch current I10 reaches the valve opening threshold current Io to time 24 when the switch current I10 becomes less than the valve closing threshold current Ic, the injection amount of the injector 5 is as shown in FIG. ) As shown.

  By the way, in such an ECU 1, there is an individual difference in the booster circuit 30. The individual difference of the booster circuit 30 occurs due to variations in the inductance component and resistance component of the inductor L10, the on-resistance and switching time of the transistor T10, the forward voltage of the diode D10, the capacitor component and resistance component of the capacitor C10, for example. These elements have manufacturing tolerances due to variations in manufacturing stage and constituent materials, temperature tolerances due to temperature characteristics of the constituent materials, durability tolerances due to deterioration of the soldering parts of the constituent materials and elements, etc. An individual difference of the booster circuit 30 occurs due to each tolerance.

  Due to such individual differences of the booster circuit 30, the boosting capability of the booster circuit 30 varies. The step-up capability indicates the amount of energy stored in the capacitor C10 per unit time, and is expressed in units of [J / S]. For example, when the on-resistance of the transistor T10 is large, the temporal change in the switch current I10 during the on-period is small. In this case, as shown in FIG. 2A, the change in the switch current I10 changes from the solid line to the alternate long and short dash line, so that the time until the switch current I10 reaches the threshold current Ith1 becomes longer. Therefore, the amount of energy stored in the capacitor C10 per unit time is reduced. That is, the boosting capability of the booster circuit 30 is reduced.

  Further, when the resistance component of the capacitor C10 is large, as indicated by a one-dot chain line in FIG. 2B, the capacitor current I11 has a threshold value during the period when the switch current I10 is zero, that is, during the off period of the transistor T10. The time required to decrease to the current Ith2 becomes longer. Also in this case, since the amount of energy stored in the capacitor C10 per unit time is reduced, the boosting capability of the booster circuit 30 is reduced.

  On the other hand, when the on-resistance of the transistor T10 is small, or when the resistance component of the capacitor C10 is small, the switch current I10 and the capacitor current I11 are indicated by two-dot chain lines in FIGS. To change. Therefore, since the amount of energy stored in the capacitor C10 per unit time increases, the boosting capability of the booster circuit 30 increases.

  When there is variation in the boosting capability of the booster circuit 30 as described above, for example, as illustrated in FIG. 4, variation in the temporal change in the capacitor voltage Vc occurs. That is, assuming that the boosting capability of the ideal booster circuit 30 having no tolerance is the reference boosting capability β, when the boosting capability of the booster circuit 30 is higher than the reference boosting capability β, the capacitor voltage Vc is a solid line. It changes from a change curve to a two-dot chain line change curve. That is, the rising speed of the capacitor voltage Vc is faster than that in the case of the reference boosting capability β.

  When the boosting capability of the booster circuit 30 is a value α2 lower than the reference boosting capability β, the capacitor voltage Vc changes from a solid curve to a one-dot chain curve. That is, the rising speed of the capacitor voltage Vc is slower than that in the case of the reference boosting capability β.

  Due to such a difference in boosting ability, the injector current I20 also varies. Specifically, when the injection signal changes as shown by the solid line in FIG. 5A, the injector current I20 when the boosting capability of the booster circuit 30 is set to the reference boosting capability β is shown by the solid line in FIG. 5B. Suppose that it changes as shown in. In this case, when the boosting capability of the booster circuit 30 is lower than the reference boosting capability β, the injector current I20 changes as indicated by the one-dot chain line in FIG. 5B, and therefore the switch current I10 is the valve opening threshold current. The time to reach Io is delayed compared to the case of the reference boosting capability β. That is, since the injector 5 opens later, the injection amount is reduced as a result.

  On the other hand, when the boosting capability of the booster circuit 30 is larger than the reference boosting capability β, the injector current I20 changes as indicated by a two-dot chain line in FIG. The timing for reaching the threshold current Io is earlier than in the case of the reference boosting capability β. That is, since the injector 5 opens earlier, the amount of injection increases as a result.

  As described above, the injection amount varies depending on the boosting capability of the booster circuit 30. In order to solve this problem, the ECU 1 of the present embodiment adjusts the injection setting time H according to the boosting capacity α of the booster circuit 30.

  Next, a method for adjusting the injection set time H will be described. First, a method for detecting the boost capability α of the boost circuit 30 by the ECU 1 will be described.

  As shown in FIG. 1, the ECU 1 includes a boosted voltage detection unit 7. As shown in FIG. 6, the boosted voltage detection unit 7 includes comparators 70 and 71.

  A voltage obtained by dividing the battery voltage VB by the voltage dividing resistors R30 and R31 is input to the non-inverting input terminal of the comparator 70. A voltage obtained by dividing the capacitor voltage Vc by the voltage dividing resistors R32 and R33 is input to the inverting input terminal of the comparator 70. When the capacitor voltage Vc becomes equal to or higher than the battery voltage VB, the resistance values of the resistors R30 to R33 are adjusted so that the signal level of the output signal of the comparator 70 is switched from the low level to the high level.

  A voltage obtained by dividing the battery voltage VB by the voltage dividing resistors R40 and R41 is input to the non-inverting input terminal of the comparator 71. A voltage obtained by dividing the capacitor voltage Vc by the voltage dividing resistors R42 and R43 is input to the inverting input terminal of the comparator 71. When the capacitor voltage Vc becomes equal to or higher than the target boost voltage Vth, the resistance values of the resistors R40 to R43 are adjusted so that the signal level of the output signal of the comparator 71 is switched from the low level to the high level. The target boost voltage Vth is set to a value larger than the battery voltage VB. The target boost voltage Vth is set in advance by experiments or the like so that the boost capability α can be detected.

  The outputs of the comparators 70 and 71 are taken into the microcomputer 2. As shown in FIG. 7, the microcomputer 2 includes a boost time detection means 20, a boost capability calculation means 21, an injection time correction means 22, and an injection time instruction means 23.

  Boosting time detection means 20 detects boosting time ΔT required for capacitor voltage Vc to reach target boosted voltage Vth from battery voltage VB based on the outputs of comparators 70 and 71. Specifically, the boost time detection means 20 detects the boost time ΔT when the condition that the capacitor C10 is not discharged and the capacitor voltage Vc is equal to or lower than the battery voltage VB is satisfied. For example, when the ignition switch is turned on, energy is not accumulated in the capacitor C10, and the injectors 5 and 6 are not driven, so the above condition is satisfied. In this case, as shown in FIG. 8, for example, if the ignition switch of the vehicle is turned on and power is turned on to the ECU 1 at time t30, no energy is stored in the capacitor C10. The capacitor C10 is charged via Therefore, capacitor voltage Vc rises to battery voltage VB. At time t31 when the capacitor voltage Vc reaches the battery voltage VB, the output of the comparator 70 changes from low level to high level. Thereafter, when the booster circuit 30 performs the boosting operation and the capacitor voltage Vc reaches the target boosted voltage Vth at time t32, the output of the comparator 71 changes from low level to high level at time t32.

  The boosting time detection means 20 measures the boosting time ΔT by measuring the time from the time t31 when the output of the comparator 70 switches from the low level to the high level until the time t32 when the output of the comparator 71 switches from the low level to the high level. Is detected. As shown in FIG. 7, the boosting time detection means outputs the detected boosting time ΔT to the boosting capacity calculation means 21.

The boosting capacity calculating unit 21 calculates the boosting capacity α based on the following formula f1 using the boosting time ΔT output from the boosting time detecting unit. “C _p ” indicates the capacitance of the capacitor C10, and “ΔV” indicates “Vth−VB”.

The boosting capacity calculating unit 21 outputs the calculated boosting capacity α to the injection time correcting unit 22.
The injection time correction unit 22 sets the injection correction time ΔH based on the comparison between the boosting capability α output from the boosting capability calculation unit 21 and the reference boosting capability β.

Specifically, when the boosting capability is set to the reference boosting capability β, it is assumed that the capacitor voltage Vc changes as shown in FIG. 5C, for example. The capacitor voltage Vc and the injector current I20 can be obtained by the following formulas (f2) and (f3). “En” indicates the energy of the capacitor C10 when fully charged, and “ΔE _INJ ” indicates the discharge energy of the injectors 5 and 6. “L” indicates the inductance of each solenoid 50, 60.

  When the step-up capability α is higher than the reference step-up capability β, the capacitor voltage Vc during the opening of the injectors 5 and 6 changes from a solid curve to a two-dot chain curve in FIG. That is, the capacitor voltage Vc becomes larger than that in the case of the reference boosting capability β. Therefore, the time until the injector current I20 reaches the valve opening threshold current Io is shortened. In this case, the injection time correction means 22 calculates an injection correction time ΔH that shortens the injection setting time H in order to ensure the same amount of injection as in the case of the reference boosting capability β. Specifically, the injection time correction means 22 calculates the injection correction time ΔH set to a negative value. The injection time correction means 22 basically sets the absolute value of the injection correction time ΔH to a larger value as the absolute value of the deviation between the boosting capability α and the reference boosting capability β increases.

  Further, when the boosting ability α is lower than the reference boosting ability β, the capacitor voltage Vc during the opening of the injectors 5 and 6 changes from the solid curve shown in FIG. 5C to the one-dot chain curve. That is, the capacitor voltage Vc is smaller than in the case of the reference boosting capability β. Therefore, the time until the injector current I20 reaches the valve opening threshold current Io becomes longer. In this case, the injection time correction means 22 calculates an injection correction time ΔH that makes the injection setting time H longer in order to ensure the same injection amount as in the case of the reference boosting capability β. Specifically, the injection time correction means 22 calculates the injection correction time ΔH set to a positive value. The injection time correction means 22 basically sets the absolute value of the injection correction time ΔH to a larger value as the absolute value of the deviation between the boosting capability α and the reference boosting capability β increases.

  As shown in FIG. 7, the injection time correction unit 22 outputs the calculated injection correction time ΔH to the injection time instruction unit 23.

The injection time instruction means 23 generates an injection signal for each cylinder based on engine operation information detected by various sensors such as the engine speed Ne, the accelerator opening ACC, and the engine water temperature THW. Moreover, the injection time instruction | indication means 23 correct | amends the injection setting time H of an injection signal based on the following formula | equation f4 using the injection correction time (DELTA) H.

  Accordingly, when the boosting capability α is higher than the reference boosting capability β, the injection setting time H is set to a time H1 that is shorter than the reference injection setting time Hb as shown by a two-dot chain line in FIG. Is done. Therefore, as shown in FIG. 5B, the time when the injector current I20 becomes less than the valve closing threshold current Ic is advanced. As a result, the increase in the injection amount due to the high boosting capacity α can be offset by the decrease in the injection amount that occurs when the valve closing timing of the injectors 5 and 6 is advanced, so that the injection amounts of the injectors 5 and 6 are reduced. Therefore, the injection amount corresponding to the reference boosting ability β can be approached.

  When the boosting ability α is lower than the reference boosting ability β, the injection setting time H is set to a time H2 longer than the reference injection setting time Hb, as indicated by a one-dot chain line in FIG. . Therefore, as shown in FIG. 5B, the time when the injector current I20 becomes less than the valve closing threshold current Ic is delayed. As a result, the decrease in the injection amount due to the low boosting ability α can be offset by the increase in the injection amount that occurs when the valve closing timing of the injectors 5 and 6 is delayed. As a result, the injectors 5 and 6 Can be brought close to the injection amount corresponding to the reference boosting ability β.

  As shown in FIG. 7, the injection time instruction means 23 outputs an injection signal with the injection setting time H corrected to the injector control circuit 4. Thus, the injector control circuit 4 drives the injectors 5 and 6 by turning on / off the transistors T20 to T23 based on the injection signal whose injection setting time H is corrected.

  Next, referring to FIG. 9, the correction procedure for the injection set time H executed by the microcomputer 2 will be summarized.

  As shown in FIG. 9, the microcomputer 2 first determines whether or not the capacitor C10 is discharged (step S1). If the capacitor C10 is not discharged (step S1: NO), the microcomputer 2 determines whether the capacitor voltage Vc is equal to or lower than the battery voltage VB (step S2). If the capacitor C10 is not discharged (step S1: NO) and the capacitor voltage Vc is equal to or lower than the battery voltage VB (step S2: YES), the microcomputer 2 calculates the boosting capacity α of the booster circuit 30. (Step S3). Further, the microcomputer 2 corrects the injection setting time H of the injectors 5 and 6 based on the boosting capacity α (step S4).

  According to ECU1 of this embodiment demonstrated above, the effect | action and effect shown by the following (1)-(3) can be acquired.

  (1) Since the injection setting time H of the injectors 5 and 6 is adjusted based on the individual boosting capacity α of the booster circuit 30, variations in the injection amount can be suppressed.

  (2) The injection setting time H is corrected based on a deviation between the boosting capacity α calculated by the boosting capacity calculation means 21 and a preset reference boosting capacity β. Specifically, when the boosting ability α is higher than the reference boosting ability β, the injection setting time H is corrected so as to be shorter than the reference injection setting time Hb. When the boosting capacity α is lower than the reference boosting capacity β, the injection setting time H is corrected so as to be longer than the reference injection setting time Hb. Thereby, since the injection amount of the injectors 5 and 6 can be set to a constant injection amount corresponding to the reference boosting capacity β, the variation in the injection amount can be suppressed more accurately.

  (3) The boosting time detection means 20 detects the boosting time ΔT on condition that the capacitor C10 is not discharged and the capacitor voltage Vc is equal to or lower than the battery voltage VB. As a result, the boost time ΔT can be detected with higher accuracy, so that the calculation accuracy of the boost capability α can be increased.

(Modification)
Next, a modified example of the ECU 1 of the first embodiment will be described.
In this modification, the microcomputer 2 executes the process of FIG. 10 instead of the process of FIG. That is, the microcomputer 2 determines whether or not it is a period from when the power to the ECU 1 is turned on until the fuel injection of the injectors 5 and 6 is started (step S5). When the microcomputer 2 makes an affirmative determination in the determination process in step S6 (step S5: YES), the microcomputer 2 executes the processes in steps S3 and S4. Even if it is such a structure, the effect | action and effect according to 1st Embodiment can be acquired.

Second Embodiment
Next, a second embodiment of the ECU 1 will be described. Hereinafter, the difference from the first embodiment will be mainly described.

  As shown in FIG. 11, the microcomputer 2 of the present embodiment has a boosting capacity storage unit 24. The boosting capacity storage means 24 is composed of a nonvolatile memory such as an EEPROM. When calculating the boosting capacity α of the booster circuit 30, the boosting capacity calculating unit 21 stores the calculated boosting capacity α information in the boosting capacity storage unit 24. The boosting capacity calculation unit 21 outputs the boosting capacity α stored in the boosting capacity storage unit 24 to the injection time correction unit 22 during a period during which the boosting capacity α cannot be calculated.

  The period during which the boosting capacity α cannot be calculated is a period in which at least one of the condition that the capacitor C10 is discharged and the capacitor voltage Vc exceeds the battery voltage VB is satisfied. . Further, the period during which the boosting capacity α cannot be calculated may be set as a period excluding the period from when the ECU 1 is turned on until the fuel injection to the injectors 5 and 6 is started.

  The injection time correction unit 22 sets the injection correction time ΔH based on the comparison between the boosting capability α output from the boosting capability calculation unit 21 and the reference boosting capability β.

  Next, referring to FIG. 12, the procedure for correcting the injection set time H executed by the microcomputer 2 of the present embodiment will be summarized.

  As shown in FIG. 12, the microcomputer 2 calculates the boost capability α of the booster circuit 30 in the process of step S3, and then stores the boost capability α in the boost capability storage means 24 (step S10).

  On the other hand, when the capacitor C10 is discharged (step S1: YES) or when the capacitor voltage Vc exceeds the battery voltage VB (step S2: NO), the microcomputer 2 stores the voltage in the boosting capacity storage unit 24. The boosting capability α thus obtained is read (step S11). Further, the microcomputer 2 corrects the injection setting time H of the injectors 5 and 6 based on the read boosting capacity α (step S4).

  According to ECU1 of this embodiment demonstrated above, the effect | action and effect shown by the following (4) can further be acquired.

  (4) For example, during driving of the injectors 5 and 6, at least one of the condition that the capacitor C10 is discharged and the capacitor voltage Vc exceeds the battery voltage VB is satisfied. Even in such a situation, according to the ECU 1 of the present embodiment, the injection set time H can be corrected, so that variations in the injection amount can be suppressed more accurately.

<Third Embodiment>
Next, a third embodiment of the ECU 1 will be described. Hereinafter, the difference from the second embodiment will be mainly described.

  As shown in FIG. 13, the ECU 1 of the present embodiment includes element temperature detection means 8 that detects element temperatures Ts of the inductor L10, the capacitor C10, and the like of the booster circuit 30. The element temperature detecting means 8 is composed of, for example, a thermistor. The output signal of the element temperature detecting means 8 is taken into the boosting capacity calculating means 21.

  The boosting capacity calculating means 21 detects the element temperature Ts by the element temperature detecting means 8 when calculating the boosting capacity α. The step-up capability calculating unit 21 stores the detected element temperature Ts and the calculated step-up capability α in the step-up capability storage unit 24 in association with each other. The boosting capacity calculating means 21 learns the relationship between the element temperature Ts and the boosting capacity α by associating the element temperature Ts with the boosting capacity α and storing them in the boosting capacity storage means 24 every time the boosting capacity α is calculated. Go.

  The boosting capacity calculating means 21 detects the current element temperature Ts by the element temperature detecting means 8 during a period during which the boosting capacity α cannot be calculated, and the detected booster capacity storage means 24 stores the detected element temperature Ts. Based on the past learning result, the boosting capacity α corresponding to the current element temperature Ts is calculated. The boosting capacity calculating unit 21 outputs the boosting capacity α calculated in this way to the injection time correcting unit 22 during a period during which the boosting capacity α cannot be calculated.

  The injection time correction unit 22 sets the injection correction time ΔH based on the comparison between the boosting capability α output from the boosting capability calculation unit 21 and the reference boosting capability β.

  Next, referring to FIG. 14, the correction procedure for the injection set time H executed by the microcomputer 2 will be summarized.

  As shown in FIG. 14, the microcomputer 2 calculates the step-up capability α in the process of step S3, and then detects the element temperature Ts by the element temperature detecting means 8 (step S20). Next, the microcomputer 2 stores the calculated boost capability α and the detected element temperature Ts in the boost capability storage unit 24 (step S21).

  On the other hand, when the capacitor C10 is discharged (step S1: YES) or when the capacitor voltage Vc exceeds the battery voltage VB (step S2: NO), the microcomputer 2 uses the element temperature detection means 8 to detect the element. The temperature Ts is detected (step S22). Further, the microcomputer 2 calculates the boost capability α corresponding to the detected element temperature Ts based on the relationship between the past boost capability α and the element temperature Ts stored in the boost capability storage means 24 (step S23). And the microcomputer 2 correct | amends the injection setting time H of the injectors 5 and 6 based on the said pressure | voltage rise capability (alpha) (step S4).

  According to ECU1 of this embodiment demonstrated above, the effect | action and effect shown by the following (5) can further be acquired.

  (5) The elements such as the inductor L10 and the capacitor C10 of the booster circuit 30 have so-called temperature characteristics in which characteristics change according to temperature. The temperature characteristic of such an element becomes a factor causing variations in the injection amounts of the injectors 5 and 6. In this regard, according to the ECU 1 of the present embodiment, since the injection setting time H is corrected according to the temperature of the booster circuit 30, variations in the injection amount due to the temperature characteristics of the elements can be suppressed.

<Other embodiments>
In addition, each said embodiment can also be implemented with the following forms.
The microcomputer of each of the above embodiments may set the injection correction time ΔH without using the reference boosting capability β. For example, the injection time correction unit 22 may set the injection correction time ΔH from the boosting capability α calculated by the boosting capability calculation unit 21 based on a map showing the relationship between the boosting capability α and the injection correction time ΔH. . In this case, a map indicating the relationship between the boosting capacity α and the injection correction time ΔH is created in advance by experiments or the like and stored in the nonvolatile memory of the microcomputer 2. Even if it is such a structure, the effect | action and effect according to said each embodiment can be acquired.

  The boost time detection means 20 of each of the above embodiments uses the time required for the capacitor voltage Vc to reach the target boost voltage Vth from the battery voltage VB as the boost time ΔT, but the method for calculating the boost time ΔT can be changed as appropriate. It is. In short, the boost time detection means 20 may be any device that calculates the time required for the capacitor voltage Vc to change from the first voltage value to the second voltage value higher than the first voltage value as the boost time ΔT. . Further, the boosting capacity calculating means may be any means that calculates the boosting capacity α based on the boosting time ΔT calculated by the boosting time detecting means 20 in this way.

  -This invention is not limited to said specific example. That is, the above-described specific examples that are appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above, their arrangement, conditions, and the like are not limited to those illustrated, and can be changed as appropriate. Moreover, each element with which embodiment mentioned above is provided can be combined as long as it is technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

1: High pressure injector control unit (ECU)
5, 6: Injector 8: Element temperature detecting means 20: Boosting time detecting means 21: Boosting capacity calculating means 22: Injection time correcting means 24: Boosting capacity storage means 30: Boosting circuit C10: Capacitor

Claims (6)

A high pressure injector control device (1) for controlling the drive of the injectors (5, 6),
A booster circuit (30) for storing energy in a capacitor (C10) based on a voltage supplied from the battery;
Boost time detection means (20) for detecting a boost time required for the voltage of the capacitor to change from a first voltage value to a second voltage value higher than the first voltage value;
Based on the amount of energy stored in the capacitor at the boosting time, boosting ability calculating means for exiting calculate the boosting capability indicating the amount of energy stored per unit time in the capacitor (21),
Injection time correction means (22) for correcting the injection setting time of the injector based on the boosting capability ,
The injection time correction means has a reference injection setting time corresponding to a preset reference boosting capability in advance, and when the boosting capability is higher than the reference boosting capability, The injection setting time is corrected to be shorter, and when the boosting capability is lower than the reference boosting capability, the injection setting time is corrected to be longer than the reference injection setting time. High pressure injector control device. 2. The high voltage injector control device according to claim 1, wherein the boosting time detecting means detects the boosting time on condition that the capacitor is not discharged. 3. The high voltage injector control device according to claim 1, wherein the boosting time detecting unit detects the boosting time on condition that a voltage of the capacitor is equal to or lower than a voltage of the battery. The boosting time detecting means, any one of the claims 1-3, characterized by detecting the boost time period until the fuel injection of the injector from when the power supply to the injector control unit is started The high-pressure injector control device according to Item. Boosting capacity storage means (24) for storing the boosting capacity calculated by the boosting capacity calculation means;
The injection time correcting means corrects the injection setting time based on the boosting capacity stored in the boosting capacity storage means during a period when the boosting capacity cannot be calculated by the boosting capacity calculating means. The high-pressure injector control device according to any one of claims 1 to 4 . Element temperature detecting means (8) for detecting the temperature of the element of the booster circuit;
The boosting capacity calculating means includes
When detecting the boost time, the element temperature detection means detects the temperature of the element of the boost circuit,
Information indicating the relationship between the detected temperature of the element and the boost capability is stored in the boost capability storage means,
Detected by the element temperature detecting means based on the information indicating the relationship between the temperature of the element and the boosting capacity stored in the boosting capacity storage means during a period during which the boosting capacity calculating means cannot calculate the boosting ability. The high pressure injector control device according to claim 5 , wherein the boosting capability is calculated from a temperature of the element to be operated.

Images