JP2019007401A - Control device - Google Patents

Abstract

To suppress an error between an actual electricity-carrying time and an ideal electricity-carrying time of a solenoid.SOLUTION: A control device 3 comprises: a drive control part 6 for controlling electricity-carrying to a solenoid 2a of an electromagnetic valve 2, and controlling the drive of transistors Q1, Q2; a motion state detection part 7; and a count part 8. The motion state detection part 7 detects motion states of the transistors Q1, Q2 on the basis of a terminal voltage of the solenoid 2a. The count part 8 detects a rise delay time from a time point at which a drive signal Sd is transmitted to an H-level up to a time point at which the transition of the transistor Q1 to a turn-on state is detected by the motion state detection part 7, and a fall delay time from a time point at which a drive signal Sc is transmitted to an L-level up to a time point at which the transition of the transistor Q2 to a turn-off state is detected by the motion state detection part 7. When the rise delay time detected by the count part 8 is longer than the fall delay time, the drive control part 6 elongates a finish time of a drive period by a prescribed elongation time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device that controls energization to a solenoid of an injection valve that injects fuel into an internal combustion engine.

  An injection control device that controls driving of an injection valve (electromagnetic valve) of a direct injection injector that directly injects fuel into an engine room of an internal combustion engine is provided with a control device that controls energization of a solenoid of the electromagnetic valve. The above control device controls the energization to the solenoid by driving the switching element provided to open and close the energization path to the solenoid based on the drive signal (drive command) from the microcomputer also provided in the injection control device. To do. By such an operation of the control device, the valve opening period and the opening / closing timing of the electromagnetic valve are controlled.

  In the above configuration, the actual energization time of the solenoid may not be a desired energization time (hereinafter referred to as an ideal energization time) represented by the drive signal. That is, a delay time until the switching element is turned on (hereinafter referred to as an on-delay) or a switching element between when the drive signal changes and when the energization to the solenoid is started or stopped Includes a delay time (hereinafter referred to as an off-delay) until the is turned off. In general, the on-delay and off-delay do not match exactly, but at different times.

  For this reason, the actual energization time of the solenoid is different from the ideal energization time. Here, when the on-delay is longer than the off-delay, the energization time of the solenoid becomes shorter than the ideal energization time, and there is a possibility that the combustion lean side that causes knocking may occur. For this reason, the drive signal output from the microcomputer must allow the exhaust gas deterioration to some extent and represent an energization time longer than the originally required energization time by a predetermined time.

  As a conventional technique for solving such a problem, for example, a technique described in Patent Document 1 can be cited. That is, in the technique described in Patent Document 1, the valve opening timing of the solenoid valve is determined by detecting the drive current of the injector, and the drive signal is extended based on the determination result to achieve the desired injector energization time. It is like that.

JP 2003-4921 A

  However, in the above prior art, the energization time is corrected in consideration of only the error at the start of energization of the injector, that is, the ON delay, and the error at the end of energization, that is, the OFF delay is not considered. Therefore, it cannot be said that the accuracy of matching the energization time with the ideal time is sufficiently high. In the above prior art, the microcomputer that outputs the drive signal determines the valve opening timing and extends the drive signal based on the determination result, so that immediate correction is difficult.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a control device capable of suppressing an error between an actual energization time of a solenoid and an ideal energization time.

  The control device (3, 22, 32, 42, 52) according to claim 1 controls energization to a solenoid (2a) of an injection valve (2) for injecting fuel into an internal combustion engine. Drive control unit (6, 43), operation state detection unit (7, 23) and delay time detection for controlling driving of switching element for discharging (Q1) and switching element for constant current (Q2) for opening and closing the energization path to Part (8, 33, 53).

  The drive control unit outputs a discharge on signal for turning on the discharge switching element at the start of the drive period set by the drive signal given from the outside to drive the discharge switching element on, and then the drive period Until a constant current switching element is turned on, a constant current on signal for driving the constant current switching element on and a constant current off signal for driving off the constant current switching element are output to drive the constant current switching element on and off.

  The delay time detection unit detects a rise delay time and a fall delay time. The rise delay time is a time from the time when the output of the discharge on signal is started to the time when the operation state detection unit detects that the discharge switching element is turned on. The falling delay time is the time from the time when the output of the constant current off signal is started to the time when the operation state detector detects that the constant current switching element is turned off. In such a configuration, when the rise delay time detected by the delay time detection unit is longer than the fall delay time, the drive control unit extends the end point of the drive period by a predetermined extension time.

  According to the above configuration, even when the on-delay is longer than the off-delay, in that case, the end point of the drive period is extended, and therefore, it is possible to suppress the combustion lean side that causes knocking. For this reason, the drive signal output from an external microcomputer or the like does not need to represent a power-on time that is longer than the power-on time that is originally required as in the prior art. The signal may be expressed as such. Thus, according to the above configuration, an error between the actual energization time of the solenoid and the ideal energization time can be suppressed. According to the above configuration, since the end of the drive period is extended on the control device side, an error in the energization period of the solenoid, and thus an error in the fuel injection amount, can be corrected immediately.

The figure which shows typically the structure of the injection control apparatus which concerns on 1st Embodiment. The figure which shows typically the signal waveform of each part of the injection control apparatus which concerns on 1st Embodiment. The figure which shows typically the control content of the drive control part which concerns on 1st Embodiment. The figure which shows typically the structure of the injection control apparatus which concerns on 2nd Embodiment. The figure which shows typically the structure of the injection control apparatus which concerns on 3rd Embodiment. The figure which shows typically the specific structural example of the count part which concerns on 3rd Embodiment. The figure which shows typically the structure of the injection control apparatus which concerns on 4th Embodiment. The figure which shows typically the control content of the drive control part which concerns on 4th Embodiment. The figure which shows typically the control content of the drive control part which concerns on 5th Embodiment.

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, substantially the same components are denoted by the same reference numerals and description thereof is omitted.
(First embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS.

  An injection control device 1 shown in FIG. 1 is provided in an engine ECU that is one of a plurality of electronic control devices (hereinafter referred to as ECUs) mounted on a vehicle. The engine ECU integrally controls various actuators based on various sensor signals in various driving states of the vehicle, and realizes operation in an optimal engine state.

  The injection control device 1 controls driving of an injector that injects and supplies fuel compressed to high pressure into a cylinder of an engine corresponding to an internal combustion engine mounted on a vehicle, for example. The injection control device 1 controls the energization current to the solenoid 2a of the electromagnetic valve 2 corresponding to the injection valve provided in the injector so as to open and close the electromagnetic valve. Although only one solenoid valve 2 is shown in FIG. 1, in reality, there are a number of solenoid valves corresponding to the number of cylinders of the engine, and the injection control device 1 includes the plurality of solenoid valves. A configuration for driving the valve is provided.

  In this case, the injection control device 1 performs peak current control for supplying a peak current to the solenoid 2a at the start of the set drive period, and promptly opens the solenoid valve 2. Thereafter, the injection control device 1 performs constant current control until the drive period ends, and maintains the open state of the electromagnetic valve 2. When the solenoid 2a is energized to the solenoid 2a, the valve body is displaced from the valve opening position to the valve opening position against the urging force of the return spring, and fuel injection is performed. Further, when the solenoid 2a is de-energized, the valve body is returned to the closed position by the urging force of the return spring, and the fuel injection is stopped.

  The injection control device 1 includes a control device 3, a drive circuit 4, and the like. The control device 3 is constituted by, for example, an ASIC. The control device 3 receives a drive signal TQ for instructing opening and closing of the solenoid valve 2 from the microcomputer 5 that controls the overall operation of the device when the injector is requested to drive, and a current value that flows to the solenoid 2a of the solenoid valve 2. Various command signals such as a required current value for commanding are received. The control device 3 supplies a current based on the required current value to the solenoid 2a of the electromagnetic valve 2 corresponding to the injector having a drive request.

  In the present embodiment, the microcomputer 5 is provided in the same ECU as the injection control device 1. Further, when the drive signal TQ is at a low level such as 0V (hereinafter referred to as L level), for example, the valve is closed, and when the drive signal TQ is at a high level such as + 5V (hereinafter referred to as H level), the valve is opened. It is a signal to command.

  For this reason, the drive period described above is set by a period in which the drive signal TQ is at the H level. The timing at which the drive signal TQ changes from the L level to the H level corresponds to the start of the drive period, and the timing at which the drive signal TQ changes from the H level to the L level corresponds to the end of the drive period.

  A battery voltage BATT output from an in-vehicle battery (not shown) is supplied to the injection control device 1 through a DC power supply line Ld. The injection control device 1 includes a load power supply (not shown), and the load power supply generates a boosted voltage Vboost. Note that the boosted voltage Vboost is a voltage for causing a peak current to open the solenoid valve 2 at a high speed immediately after the start of driving.

  The drive circuit 4 energizes the solenoid 2a by applying a boosted voltage Vboost applied through the boosted power supply line Lb or a battery voltage BATT applied through the DC power supply line Ld to the solenoid 2a. The drive circuit 4 includes transistors Q1 to Q3, a diode D1, and a shunt resistor Rs1.

  Transistors Q1-Q3 are all N-channel MOS transistors. The transistor Q1 corresponds to a discharging switching element that opens and closes an energization path to the solenoid 2a. The drain of the transistor Q1 is connected to the boost power supply line Lb, and the source thereof is connected to the terminal PH that is the upstream terminal of the solenoid 2a.

  The transistor Q2 corresponds to a constant current switching element that opens and closes an energization path to the solenoid 2a. The drain of the transistor Q2 is connected to the DC power supply line Ld, and the source thereof is connected to the terminal PH through the backflow preventing diode D1 in the forward direction. The drain of the transistor Q3 is connected to a terminal PL which is a downstream terminal of the solenoid 2a, and the source is connected to a ground line Lg to which a circuit reference potential (0 V) is applied via a shunt resistor Rs1.

  The shunt resistor Rs1 is for detecting a current flowing through the solenoid 2a (hereinafter also referred to as an injector current), and its terminal voltage is given to the control device 3. Gate signals Gd, Gc, and Gs output from the control device 3 are applied to the gates of the transistors Q1, Q2, and Q3, respectively. Thereby, the driving of the transistors Q1 to Q3 is controlled by the control device 3.

  The control device 3 controls energization to the solenoid 2 a and includes a drive control unit 6, an operation state detection unit 7, and a count unit 8. The drive control unit 6 includes a comparator 9, a threshold voltage generation unit 10, a drive unit 11, and drivers 12 to 14. In the present embodiment, the drive unit 11 is configured by a logic circuit.

  A terminal voltage of the shunt resistor Rs1 corresponding to the injector current is input to one input terminal of the comparator 9. In this case, the terminal voltage of the shunt resistor Rs1 corresponds to the detection voltage Vd corresponding to the injector current. An amplifier circuit that amplifies and outputs the terminal voltage of the shunt resistor Rs1 may be provided, and the output voltage of the amplifier circuit may be input to one input terminal of the comparator 9 as the detection voltage Vd corresponding to the injector current. .

  The threshold voltage Vt1 generated by the threshold voltage generator 10 is input to the other input terminal of the comparator 9. The threshold voltage generation unit 10 includes a DAC, for example, and its operation is controlled by the drive unit 11. In this case, the drive unit 11 controls the operation of the threshold voltage generation unit 10 so that the threshold voltage Vt1 becomes a voltage that represents the target value of the current corresponding to each control period.

  Thereby, the threshold voltage Vt1 becomes a voltage corresponding to the target value of the peak current during the period in which the peak current control is performed, and is a voltage corresponding to the target value of the pickup current or the hold current in the period in which the constant current control is performed. Become. There are two target values for the pickup current and the hold current, an upper threshold and a lower threshold, respectively.

  The comparator 9 compares the detection voltage Vd and the threshold voltage Vt1, and outputs a signal representing the comparison result. The drive unit 11 drives the drive signals Sd, Sc, and the drive signals Sd, Sc, and Q3 for driving the transistors Q1, Q2, and Q3 of the drive circuit 4 based on the drive signal TQ and various command signals supplied from the microcomputer 5, the output signal of the comparator 9, and the like. Ss is generated.

  The drive signals Sd, Sc, and Ss are ON drive signals that drive the transistors Q1, Q2, and Q3 on when all are at the H level, and off drive that drives the transistors Q1, Q2, and Q3 off when the drive signals are at the L level. Signal. In the present embodiment, the H level drive signal Sd corresponds to a discharge on signal for turning on the transistor Q1. The H level drive signal Sc corresponds to a constant current on signal for driving the transistor Q2 on, and the L level drive signal Sc corresponds to a constant current off signal for driving the transistor Q2 off.

  The drivers 12 to 14 receive the drive signals Sd, Sc, and Ss supplied from the drive unit 11 and output gate signals Gd, Gc, and Gs corresponding to the drive signals Sd, Sc, and Ss, respectively. With such a configuration, the drive control unit 6 controls the operation of the drive circuit 4 so that the injector current matches the target value.

  The operation state detection unit 7 detects the operation state of the transistors Q1 and Q2, particularly that the transistors Q1 and Q2 are turned on and the transistors Q1 and Q2 are turned off. Such detection can be performed based on the terminal voltage of the solenoid 2a. In this case, the operation state detection unit 7 detects the operation state of the transistors Q1 and Q2 based on the inter-terminal voltage that is the difference voltage between the voltage at the terminal PH of the solenoid 2a and the voltage at the terminal PL.

  The operating state detection unit 7 includes a differential voltage detection unit 15, a comparator 16, and a threshold voltage generation unit 17. The differential voltage detector 15 receives the voltages of the terminals PH and PL, and outputs a voltage representing the voltage across the terminals of the solenoid 2a, which is the difference between them.

  The comparator 16 compares the output voltage of the differential voltage detector 15 with the threshold voltage Vt2 generated by the threshold voltage generator 17, and outputs a signal COMPout representing the comparison result. The comparator 16 outputs an H level signal COMPout during a period when the output voltage of the differential voltage detector 15 is higher than the threshold voltage Vt2, and also outputs an L level signal when the output voltage of the differential voltage detector 15 is lower than the threshold voltage Vt2. It is configured to output COMPout.

  Further, in the present embodiment, the threshold voltage Vt2 determines the voltage between the terminals of the solenoid 2a when the transistors Q1 and Q2 are on and the voltage between the terminals of the solenoid 2a when the transistors Q1 and Q2 are off. The voltage value that can be set is set. Note that the voltage value of the threshold voltage Vt2 may be switched between a period in which peak current control is performed and a period in which constant current control is performed.

  According to the operation state detection unit 7 configured as described above, it is possible to detect that the transistors Q1 and Q2 are turned on and turned off based on the output signal COMPout of the comparator 16. That is, the operating state detection unit 7 detects that the transistors Q1 and Q2 are turned on by the rising edge of the output signal COMPout of the comparator 16, and the transistors Q1 and Q2 are turned off by the falling edge of the output signal COMPout. Detected.

  The count unit 8 is input with signals indicating the output states of the drive signals Sd and Sc output from the drive unit 11 of the drive control unit 6 and the output signal COMPout of the comparator 16 of the operation state detection unit 7. ing. In the present embodiment, the count unit 8 is configured by a logic circuit, and detects (calculates) the rising delay time Tdr and the falling delay time Tcf based on each input signal described above. Therefore, in the present embodiment, the count unit 8 corresponds to a delay time detection unit.

  As shown in FIG. 2, the rise delay time Tdr (hereinafter also referred to as the delay time Tdr) is determined from the time when the output of the discharge on signal is started, that is, from the time when the drive signal Sd changes from the L level to the H level. This is the time from when it is detected that Q1 has turned on, that is, the time when the output signal COMPout has changed from L level to H level. The delay time Tdr includes a delay time associated with the operation of the driver 12 and a delay time associated with the turn-on operation of the transistor Q1.

  As shown in FIG. 2, the falling delay time Tcf (hereinafter also referred to as the delay time Tcf) is from the time when the output of the constant current off signal is started, that is, from the time when the drive signal Sc changes from H level to L level. , The time from when it is detected that the transistor Q2 is turned off, that is, the time when the output signal COMPout is changed from H level to L level. The delay time Tcf includes a delay time associated with the operation of the driver 13 and a delay time associated with the turn-off operation of the transistor Q2.

  The count unit 8 can also detect (calculate) the falling delay time Tdf and the rising delay time Tcr. As shown in FIG. 2, the falling delay time Tdf (hereinafter also referred to as delay time Tdf) is detected from the time when the drive signal Sd changes from the H level to the L level. This is the time until the time point, that is, the time point when the output signal COMPout changes from H level to L level. The delay time Tdf includes a delay time associated with the operation of the driver 12 and a delay time associated with the turn-off operation of the transistor Q1.

  As shown in FIG. 2, the rising delay time Tcr (hereinafter also referred to as the delay time Tcr) is from the time when the output of the constant current ON signal is started, that is, from the time when the drive signal Sc changes from L level to H level. This is the time from when it is detected that the transistor Q2 is turned on, that is, the time when the output signal COMPout is changed from L level to H level. The delay time Tcr includes a delay time associated with the operation of the driver 13 and a delay time associated with the turn-on operation of the transistor Q2.

  The count unit 8 calculates the delay times Tdr and Tcf and outputs signals representing the delay times Tdr and Tcf to the drive unit 11. Further, when the calculated delay time Tdr is longer than the delay time Tcf (Tdr> Tcf), the count unit 8 calculates a time obtained by subtracting the delay time Tcf from the delay time Tdr, and calculates the time (= Tdr−Tcf). The signal to represent is output to the drive part 11.

  When the delay time Tdr detected by the count unit 8 is longer than the delay time Tcf, the drive unit 11 of the drive control unit 6 extends the end point of the drive period by a predetermined extension time. In the present embodiment, the extension time is set based on the delay times Tdr and Tcf. Specifically, the extension time is set to a time obtained by subtracting the delay time Tcf from the delay time Tdr (= Tdr−Tcf).

  In the above configuration, the same ground line Lg is supplied to the control device 3 side ground (IC side ground) and the solenoid 2a side ground (load side ground) serving as the load of the control device 3. In other words, the grounds have a common configuration, but these grounds may have different configurations. When the IC-side ground and the load-side ground are different from each other, the current detection configuration (the comparator 9 and the threshold voltage generation unit 10) may be a differential configuration instead of a single-ended configuration.

Next, the operation of the above configuration will be described with reference to FIGS.
[1] Basic operation of injection control device 1 when solenoid valve 2 is opened In the above configuration, at the start of the set drive period, drive control unit 6 drives transistors Q1 and Q3 on and transistor Q2 off. By doing so, peak current control is executed. Based on the output signal of the comparator 9, the drive control unit 6 turns off the transistor Q1 when the injector current reaches the target value of the peak current, thereby ending the peak current control.

  Thereafter, the drive control unit 6 performs constant current control until the drive period ends. In the constant current control, the drive control unit 6 drives the transistor Q1 off and drives the transistor Q3 on, and then drives the transistor Q2 on and off. In the first half of the constant current control, the drive control unit 6 is based on the output signal of the comparator 9 so that the injector current is within the settling range sandwiched between the upper threshold value and the lower threshold value of the relatively high pickup current. The transistor Q2 is turned on / off.

  Further, in the second half of the constant current control, the drive control unit 6 controls the transistor based on the output signal of the comparator 9 so that the injector current is within the settling range sandwiched between the upper threshold value and the lower threshold value of the relatively low hold current. Q2 is turned on / off. In FIG. 2, illustration of the first half of constant current control is omitted.

[2] Ideal energization period and actual energization period for the injector As shown in FIG. 2, the period during which the drive signal TQ is at the H level is a set drive period and is desired for the solenoid valve 2 of the injector. This corresponds to the energization time Ttq (ideal energization time Ttq). On the other hand, the actual energization time Treal is as shown in FIG. 2 and the following equation (1).
Treal = Ttq−Tdr + Tcf (1)

  There is a delay time associated with the operation of the drive unit 11 from the time when the drive signal TQ changes from the L level to the H level to the time when the drive signal Sd changes from the L level to the H level. A delay time similar to the above also exists from the time when the drive signal TQ changes from the H level to the L level to the time when the drive signal Sc changes from the H level to the L level. However, each delay time associated with the operation of the drive unit 11 is very short compared to the delay times Tdr and Tcf, and therefore does not affect the control for extending the drive period described later. Therefore, here, each delay time associated with the operation of the drive unit 11 is ignored (assumed to be zero).

  As shown in the above equation (1), the actual energization time Treal is affected by the rise delay time Tdr, the fall delay time Tcf, and the like, and is different from the ideal energization time Ttq. In particular, as shown in FIG. 2, when the rise delay time Tdr is longer than the fall delay time Tcf, the actual energization time Treal is shorter than the ideal energization time Ttq, and there is a risk of turning to the combustion lean side causing knocking. Arise. In order to prevent the occurrence of such a situation, the drive control unit 6 of the present embodiment performs the following control.

[3] Control content of drive control unit 6 The drive control unit 6 executes control of content as shown in FIG. In step S101, it is determined whether or not the drive signal TQ has changed from the L level to the H level. When the drive signal TQ changes from the L level to the H level, “YES” is determined in the step S101, and the process proceeds to the step S102.

  In step S102, peak current control is started, and in step S103, the delay time Tdr is measured based on the signal output from the count unit 8. Thereafter, when the process proceeds to step S104, the constant current control is started, and in step S105, the delay time Tcf is measured based on the signal output from the count unit 8.

  In step S106 executed after step S105, it is determined whether or not the delay time Tdr is longer than the delay time Tcf. If the delay time Tdr is longer than the delay time Tcf, “YES” is determined in the step S106, and the process proceeds to the step S107. In step S107, an extension time for extending the drive period is set. After execution of step S107, the process proceeds to step S108.

  On the other hand, when the delay time Tdr is equal to or shorter than the delay time Tcf, “NO” is determined in the step S106, and the process proceeds to the step S108 without executing the step S107. In step S108, it is determined whether or not the drive signal TQ has changed from the H level to the L level. When the drive signal TQ changes from the H level to the L level, “YES” is determined in the step S108, and the process proceeds to the step S109.

  In step S109, it is determined whether an extension time is set. If the extension time is set, “YES” is determined in the step S109, and the process proceeds to the step S110. In step S110, the end point of the driving period is extended by the set extension time. In this case, the driving period set by the driving signal TQ has already ended, but the constant current control is continuously executed. After execution of step S110, the process proceeds to step S111.

  On the other hand, if the extension time is not set, “NO” is determined in the step S109, the step S110 is not executed, the constant current control is ended in the step S111, and the driving of the electromagnetic valve 2 of the injector is ended. It becomes.

[4] Drive Period Extension Operation by Drive Control Unit 6 When the drive period is extended, the drive control unit 6 performs either the following first operation or second operation. The first operation is the following operation. That is, the drive unit 11 continues to output the drive signal Sc even after the drive signal TQ changes from the H level to the L level.

  As a result, the transistor Q2 is driven on and off so that the injector current is within the settling range sandwiched between the upper limit threshold and the lower limit threshold of the hold current. Then, when the extension time set from the time when the drive signal TQ changes from the H level to the L level has elapsed, the drive unit 11 stops the output of the drive signal Sc, thereby controlling the constant current and thus the solenoid valve of the injector. The driving of No. 2 ends.

  The second operation is the following operation. That is, in the drive controller 6, after the drive signal TQ changes from the H level to the L level, the upper limit threshold value of the hold current is increased by a predetermined value. The predetermined value is set to a value corresponding to the extension time so that the longer the set extension time is, the larger the value is.

  As a result, after the drive signal TQ changes from the H level to the L level, the period during which the battery voltage BATT is applied between the terminals of the solenoid 2a is extended by an amount corresponding to the increased upper limit threshold. By such first operation or second operation, the drive period, that is, the energization period to the solenoid 2a of the solenoid valve 2 is extended, and as a result, the time until the solenoid valve 2 is closed can be extended. .

According to this embodiment described above, the following effects can be obtained.
The control device 3 of the present embodiment includes an operation state detection unit 7 that detects the operation state of the transistors Q1 and Q2 based on the terminal voltage of the solenoid 2a, and an output state of the drive signals Sd and Sc output from the drive control unit 6. And a count unit 8 for detecting the rise delay time Tdr and the fall delay time Tcf based on the detection result of the operation states of the transistors Q1 and Q2 by the operation state detection unit 7. When the delay time Tdr detected by the count unit 8 is longer than the delay time Tcf, the drive control unit 6 extends the end point of the drive period by a predetermined extension time.

  According to such a configuration, even if the on-delay is longer than the off-delay, in that case, the end point of the drive period, and thus the end point of the energization period of the injector, is extended. It is suppressed to turn to the side. For this reason, the drive signal TQ output from the external microcomputer 5 does not have to represent a current-carrying time that is longer by a predetermined time than the power-carrying time that is originally required as in the prior art. May be a signal that represents.

  Thus, according to the above configuration, an error between the actual energization time of the injector (solenoid valve 2) and the ideal energization time can be suppressed. Therefore, according to the injection control device 1 of the present embodiment, it is possible to realize energization to the injector with the intended energization time. The effect by this embodiment mentioned above becomes especially useful when the injection control apparatus 1 is applied to the lean burn engine used in severe A / F setting, and can fully draw out the performance of the lean burn engine. It becomes possible.

  Further, according to the above configuration, since the end of the driving period is extended on the control device 3 side, the error in the energization period of the solenoid 2a, and hence the error in the fuel injection amount, is detected as the injection (current injection). Can be corrected immediately. In other words, according to the above configuration, correction (extension of the driving period) is performed on the control device 3 side, so that it is possible to perform correction more quickly than, for example, a configuration in which the correction is performed by the microcomputer 5, and the injection The correction can be reflected from (current injection).

  In the above configuration, when the transistor Q3 is turned on with the transistor Q3 turned on, the boosted voltage Vboost is applied between the terminals of the solenoid 2a. When the transistor Q2 is turned on completely, the battery is connected between the terminals of the solenoid 2a. A voltage BATT is applied. In the above configuration, when the transistors Q1 and Q2 are completely turned off, the voltage between the terminals of the solenoid 2a becomes zero. That is, if the voltage between the terminals of the solenoid 2a is monitored, the operating states of the transistors Q1 and Q2 can be accurately detected.

  Therefore, the operation state detection unit 7 includes a comparator 16 that compares the voltage between the terminals of the solenoid 2a and the threshold voltage Vt2, and detects the operation state of the transistors Q1 and Q2 based on the output signal COMPout of the comparator 16. Yes. According to such a configuration, the operation states of the transistors Q1 and Q2 can be detected with high accuracy, so that the detection accuracy of the delay times Tdr and Tcf can also be improved.

  As shown in the above equation (1), the actual energization time Treal of the solenoid 2a is a time obtained by subtracting the delay time Tdr from the ideal energization time Ttq and adding the delay time Tcf. Therefore, in the present embodiment, the extension time for extending the drive period is set to a time (= Tdr−Tcf) obtained by subtracting the delay time Tcf from the delay time Tdr. In this way, when the delay time Tdr is longer than the delay time Tcf, the actual energization time Treal of the solenoid 2a can be made closer to the ideal energization time Ttq.

(Second Embodiment)
Hereinafter, a second embodiment will be described with reference to FIG.
As shown in FIG. 4, the control device 22 included in the injection control device 21 of the present embodiment includes an operation state detection unit 23 instead of the operation state detection unit 7 with respect to the control device 3 of the first embodiment. The point is different.

  The operation state detector 23 detects the operation state of the transistors Q1 and Q2 based on the terminal voltage of the solenoid 2a, and includes a comparator 24 and a threshold voltage generator 25. The comparator 24 is an overcurrent detection comparator originally provided in the control device 22 in order to detect an overcurrent flowing through the transistors Q1 and Q2. The operation state detection unit 23 is configured to share the comparator 24 as a comparator for detecting the operation state of the transistors Q1 and Q2.

  The comparator 24 compares the voltage at the terminal PH with the threshold voltage Vt3 generated by the threshold voltage generator 25, and outputs a signal COMPout representing the comparison result. The comparator 24 outputs an H level signal COMPout when the voltage at the terminal PH is higher than the threshold voltage Vt3, and outputs an L level signal COMPout when the voltage at the terminal PH is lower than the threshold voltage Vt3. Yes.

  In this case, the threshold voltage Vt3 is a voltage value at which the overcurrent can be detected, and the voltage between the terminals of the solenoid 2a when the transistors Q1 and Q2 are on and when the transistors Q1 and Q2 are off. The voltage between the terminals of the solenoid 2a is set to a voltage value that can be determined. Therefore, in this case, the threshold voltage generation unit 25 is configured to be shared by the configuration for detecting an overcurrent and the operation state detection unit 23.

  Depending on the overcurrent detection conditions, it may be difficult to share the configuration for generating the threshold voltage input to the comparator 24. In such a case, the threshold voltage for detecting the overcurrent and the threshold voltage for detecting the operation state of the transistors Q1 and Q2 are generated by separate threshold voltage generation units, and the threshold voltages are the same. What is necessary is just to switch and input to the comparator 24.

  Also with the operation state detection unit 23 of the present embodiment described above, as with the operation state detection unit 7 of the first embodiment, the operation states of the transistors Q1 and Q2, particularly that the transistors Q1 and Q2 are turned on and the transistor Q1 , Q2 can be detected to turn off. Therefore, according to this embodiment, the same effect as that of the first embodiment can be obtained.

  Furthermore, the operation state detection unit 23 is configured to share the comparator 24 and the threshold voltage generation unit 25 that are originally provided in the control device 22 and used for detecting overcurrent. Therefore, the control device 22 of the present embodiment can reduce the circuit area and thus the manufacturing cost as much as the comparator 24 and the like are shared.

(Third embodiment)
Hereinafter, a third embodiment will be described with reference to FIGS. 5 and 6.
As shown in FIG. 5, the control device 32 included in the injection control device 31 of the present embodiment differs from the control device 3 of the first embodiment in that a count unit 33 is provided instead of the count unit 8. .

  The count unit 33 corresponds to a delay time detection unit, and is configured by an analog circuit that realizes the same function as the count unit 8. As a specific configuration of the count unit 33, for example, a configuration as shown in FIG. 6 can be adopted. In this case, the start signal START and the reset signal RESET output from the drive unit 11 of the drive control unit 6 and the output signal COMPout of the comparator 16 of the operation state detection unit 7 are input to the count unit 33. Yes. Note that the start signal START and the reset signal RESET correspond to signals representing the output states of the drive signals Sd and Sc.

  As shown in FIG. 6, the count unit 33 includes a signal generation circuit 34, a capacitor 35, switches 36 and 37, a current source 38, and an A / D converter 39 (hereinafter referred to as ADC 39). An output signal COMPout and a start signal START are input to the signal generation circuit 34. The signal generation circuit 34 outputs a signal that changes according to the level of each input signal.

  Specifically, when the start signal START is at the L level, the signal generation circuit 34 fixes the output signal at the L level regardless of the level of the output signal COMPout. When the start signal START changes from L level to H level, the signal generation circuit 34 changes the output signal to H level regardless of the level of the output signal COMPout. Thereafter, the signal generation circuit 34 changes the output signal to the L level at the timing when the level of the output signal COMPout is inverted.

  One terminal of the capacitor 35 is connected to a power supply line Ldd to which a power supply voltage VDD (for example, +5 V) is applied via a switch 36 and a current source 38 that outputs a constant current, and the other terminal is connected to the ground line Lg. It is connected. A switch 37 is connected between the terminals of the capacitor 35.

  Opening / closing (ON / OFF) of the switch 36 is controlled by an output signal of the signal generation circuit 34. Specifically, the switch 36 is turned on when the output signal of the signal generation circuit 34 is at the H level, and is turned off when the output signal is at the L level. Opening and closing of the switch 37 is controlled by a reset signal RESET. Specifically, the switch 37 is turned on when the reset signal RESET is at the H level and turned off when the reset signal RESET is at the L level.

  An inter-terminal voltage of the capacitor 35 is input to the input terminal of the ADC 39. Although not shown, the ADC 39 also receives the output signal COMPout. The ADC 39 performs A / D conversion on the voltage (voltage between terminals of the capacitor 35) input via the input terminal at the timing when the output signal COMPout is inverted or at a timing thereafter. The ADC 39 outputs the digital signal obtained by the A / D conversion to the drive unit 11 of the drive control unit 6 as a count signal representing the delay times Tdr and Tcf.

Next, the delay time detection operation by the count unit 33 having the above-described configuration will be described.
Note that the drive unit 11 fixes the start signal START at the L level during a period when the detection operation for detecting the delay time is not performed. Therefore, during a period when the detection operation is not performed, the switch 36 is turned off and the capacitor 35 is not charged.

  Further, the drive unit 11 sets the reset signal RESET to the H level for a predetermined time in a period in which the detection operation is not performed. As a result, as will be described later, the voltage across the terminals of the capacitor 35 charged in the detection operation is reset to zero. Note that the drive unit 11 fixes the reset signal RESET at the L level except for the predetermined time described above.

[1] Detection Operation of Delay Time Tdr The drive unit 11 changes the start signal START from the L level to the H level at the rising timing of the drive signal Sd. As a result, the output signal of the signal generation circuit 34 turns to H level, the switch 36 is turned on, and the capacitor 35 is charged by the current output from the current source 38. After that, when the output voltage of the differential voltage detector 15 reaches the threshold voltage Vt2 and the output signal COMPout of the comparator 16 changes from L level to H level, the output signal of the signal generation circuit 34 changes to L level and the switch 36 is turned off. Thus, charging of the capacitor 35 is stopped.

  The voltage between the terminals of the capacitor 35 at this time is a voltage corresponding to the time from the time when the drive signal Sd changes from the L level to the H level to the time when the output signal COMPout changes from the L level to the H level, that is, the delay time Tdr. It becomes. The ADC 39 A / D converts the voltage across the capacitor 35 at this time. The digital signal obtained by this A / D conversion is output to the drive unit 11 as a count signal representing the delay time Tdr.

[2] Detection Operation of Delay Time Tcf The drive unit 11 changes the start signal START from the L level to the H level at the falling timing of the drive signal Sc. As a result, the output signal of the signal generation circuit 34 turns to H level, the switch 36 is turned on, and the capacitor 35 is charged by the current output from the current source 38. Thereafter, when the output voltage of the differential voltage detector 15 reaches the threshold voltage Vt2 and the output signal COMPout of the comparator 16 changes from H level to L level, the output signal of the signal generation circuit 34 changes to L level and the switch 36 is turned off. Thus, charging of the capacitor 35 is stopped.

  The voltage between the terminals of the capacitor 35 at this time is a voltage corresponding to the time from the time when the drive signal Sc changes from the H level to the L level to the time when the output signal COMPout changes from the H level to the L level, that is, the delay time Tcf. It becomes. The ADC 39 A / D converts the voltage across the capacitor 35 at this time. The digital signal obtained by this A / D conversion is output to the drive unit 11 as a count signal representing the delay time Tcf.

  Also by the count unit 33 of the present embodiment described above, similarly to the count unit 8 of the first embodiment, the rise delay time Tdr and the rise time are determined based on the detection results of the operation states of the transistors Q1 and Q2 by the operation state detection unit 7. The falling delay time Tcf can be detected. Therefore, according to this embodiment, the same effect as that of the first embodiment can be obtained.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to FIGS. 7 and 8.
As shown in FIG. 7, the control device 42 included in the injection control device 41 of the present embodiment includes a drive control unit 43 instead of the drive control unit 6 with respect to the control device 3 of the first embodiment. Is different.

  In this case, the various command signals transmitted from the microcomputer 5 include a change presence / absence signal indicating whether or not the drive period set by the drive signal TQ has been changed. Specifically, the change presence / absence signal indicates whether or not the drive period set by the drive signal TQ transmitted this time is changed from the drive period set by the drive signal TQ transmitted last time.

  Thus, in the present embodiment, the microcomputer 5 notifies the control device 42 whether the drive period in the current injection is the same as or different from the drive period in the previous injection. The drive unit 44 of the drive control unit 43 stores a drive period set by the drive signal TQ every time the drive signal TQ is input.

  When the drive unit 44 determines that the current drive period is not changed from the previous drive period based on the change presence / absence signal, the delay time Tdr detected by the count unit 8 is shorter than the delay time Tcf. The end point of the driving period is shortened by a predetermined shortening time. In the present embodiment, the shortening time is set based on the delay times Tdr and Tcf. Specifically, the shortened time is set to a time obtained by subtracting the delay time Tdr from the delay time Tcf (= Tcf−Tdr).

Next, the operation of the above configuration will be described with reference to FIG.
The drive control unit 43 performs control of contents as shown in FIG. In the control by the drive control unit 43 shown in FIG. 8, steps S201 to S203 are added to the control by the drive control unit 6 shown in FIG.

  In this case, if the delay time Tdr detected by the count unit 8 is equal to or shorter than the delay time Tcf, that is, if “NO” in the step S106, the process proceeds to a step S201. In step S201, it is determined whether or not the current drive period has been changed from the previous drive period, that is, whether or not the drive period has been changed.

  If the drive period has been changed, “NO” is determined in the step S201, and the process proceeds to the step S108. On the other hand, if the drive period has not been changed, “YES” is determined in the step S201, and the process proceeds to the step S202. In step S202, a shortening time for shortening the driving period is set.

  In the subsequent step S203, it is determined whether or not the shortened drive period has ended based on the previous drive period and the shortened time set in step S202. When the shortened drive period is completed, “YES” is determined in the step S203, and the process proceeds to the step S111 so as to complete the constant current control and consequently the driving of the electromagnetic valve 2 of the injector.

  Also by this embodiment described above, the same effect as the first embodiment can be obtained. In the present embodiment, when the drive control unit 43 determines that the current drive period is not changed from the previous drive period based on the change presence / absence signal, the delay time Tdr detected by the count unit 8 is determined. Is shorter than the delay time Tcf, the end point of the driving period is shortened by a predetermined shortening time.

  According to such a configuration, even when the on-delay is shorter than the off-delay, in that case, the end point of the drive period, and hence the end point of the energization period of the injector, is shortened, so that it shifts to the combustion rich side. It is suppressed. Therefore, according to the injection control device 41 of the present embodiment, the actual energization time of the injector can be made closer to the intended time.

  As shown in the above equation (1), the actual energization time Treal of the solenoid 2a is a time obtained by subtracting the delay time Tdr from the ideal energization time Ttq and adding the delay time Tcf. Therefore, in the present embodiment, the shortening time for shortening the drive period is set to a time (= Tcf−Tdr) obtained by subtracting the delay time Tdr from the delay time Tcf. In this way, when the delay time Tdr is shorter than the delay time Tcf, the actual energization time Treal of the solenoid 2a can be made closer to the ideal energization time Ttq.

(Fifth embodiment)
The fifth embodiment will be described below with reference to FIG.
As shown in FIG. 9, the control device 52 included in the injection control device 51 of the present embodiment is provided with a count unit 53 instead of the count unit 8 with respect to the control device 3 of the first embodiment, a storage unit The difference is that 54 is added. The count unit 53 has a function similar to that of the count unit 8 and corresponds to a delay time detection unit.

  In this case, the count unit 53 stores the calculated delay times Tdr and Tcf in the storage unit 54. When the calculated delay time Tdr is longer than the delay time Tcf, the count unit 53 reads the past delay times Tdr and Tcf stored in the storage unit 54. The count unit 53 calculates a time obtained by subtracting the average value of the past delay times Tcf from the average value of the past delay times Tdr, and outputs a signal representing the time to the drive unit 11.

  With this configuration, in this embodiment, the extension time is set based on the delay times Tdr and Tcf stored in the storage unit 54. According to this embodiment, the same effect as that of the first embodiment can be obtained.

(Other embodiments)
In addition, this invention is not limited to each embodiment described above and described in drawing, In the range which does not deviate from the summary, it can change, combine or expand arbitrarily.
The extension time and the reduction time are not limited to the time based on the delay times Tdr and Tcf, and may be set to arbitrary times. For example, the extension time or the shortening time is set based on at least one of the delay times Tdr, Tdf, Tcr, Tcf, or at least one of the delay times Tdr, Tdf, Tcr, Tcf. You may set it.

  Also in the fourth embodiment, if the storage unit 54 that stores the delay times Tdr and Tcf is added as in the fifth embodiment, the shortening time is based on the past delay times Tdr and Tcf stored in the storage unit 54. Can be set.

  Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

  2 ... Solenoid valve, 2a ... Solenoid, 3, 22, 32, 42, 52 ... Control device, 6, 43 ... Drive control unit, 7, 23 ... Operating state detection unit, 8, 33, 53 ... Count unit, 16, 24: Comparator, 54: Memory, Q1, Q2: Transistor.

Claims (9)

A control device (3, 22, 32, 42, 52) for controlling energization to a solenoid (2a) of an injection valve (2) for injecting fuel into an internal combustion engine,
It controls the driving of the discharging switching element (Q1) and the constant current switching element (Q2) for opening and closing the energization path to the solenoid, and at the start of the driving period set by the driving signal given from the outside To output a discharge on signal for turning on the discharge switching element to turn on the discharge switching element, and then turn on the constant current switching element until the end of the drive period. A constant current on signal and a constant current off signal for driving off to drive the constant current switching element on and off, and a drive control unit (6, 43);
An operation state detector (7, 23) for detecting an operation state of the discharge switching element and the constant current switching element based on a terminal voltage of the solenoid;
Rise delay time from the time when the output of the discharge on signal is started to the time when the operation state detecting unit detects that the discharge switching element is turned on, and the output of the constant current off signal starts A delay time detecting unit (8, 33, 53) for detecting a falling delay time from when the operation state detecting unit detects that the constant current switching element is turned off to ,
With
The drive control unit is configured to extend the end point of the drive period by a predetermined extension time when the rise delay time detected by the delay time detection unit is longer than the fall delay time.   The operation state detection unit includes a comparator (16, 24) that compares a terminal voltage of the solenoid and a threshold voltage for detecting the operation state, and the discharge switching element is based on an output signal of the comparator. The control device according to claim 1, wherein the control device detects that it has turned on and that the constant current switching element has turned off. An overcurrent detection comparator (24) for detecting an overcurrent flowing in at least one of the discharge switching element and the constant current switching element;
The control device according to claim 2, wherein the operation state detection unit (23) is configured to use the overcurrent detection comparator as the comparator.   4. The drive control unit according to claim 1, wherein the drive control unit does not shorten the end point of the drive period when the rise delay time detected by the delay time detection unit is shorter than the fall delay time. 5. The control device described.   5. The control device according to claim 1, wherein the extension time is set based on the rise delay time and the fall delay time detected by the delay time detection unit. Furthermore, a storage unit (54) for storing the rising delay time and the falling delay time detected by the delay time detection unit,
5. The control device according to claim 1, wherein the extension time is set based on the rising delay time and the falling delay time stored in the storage unit. 6. A change presence / absence signal indicating whether or not the current drive period is changed from the previous drive period is input to the drive control unit (43) from the outside.
When the drive control unit determines that the current drive period is not changed from the previous drive period based on the change presence / absence signal, the rise delay time detected by the delay time detection unit is The control device according to any one of claims 1 to 6, wherein when the falling delay time is shorter, the end point of the driving period is shortened by a predetermined shortening time.   The control device according to claim 7, wherein the shortening time is set based on the rising delay time and the falling delay time detected by the delay time detecting unit. Furthermore, a storage unit (54) for storing the rising delay time and the falling delay time detected by the delay time detection unit,
The control device according to claim 7, wherein the shortening time is set based on the rising delay time and the falling delay time stored in the storage unit.

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