Solenoid valve driving device

Abstract

The invention discloses an electromagnetic valve driving device. A fuel injection valve control device is provided with: a drive circuit that drives a fuel injection valve by energizing a coil of the fuel injection valve; a valve closing detection unit that detects the valve closing timing of a valve body provided in the fuel injection valve on the basis of a coil voltage value, which is a voltage value of the coil; and a failure detection unit that determines a failure on the basis of the coil voltage value read in the valve closing detection unit.

Description

Technical Field

[0001] This invention relates to a solenoid valve driving device. Background Technology

[0002] For example, Patent Document 1 discloses an internal combustion engine equipped with a fuel injection control device. The fuel injection control device disclosed in Patent Document 1 controls a fuel injection valve that directly injects fuel into the combustion chamber. In addition, the fuel injection control device disclosed in Patent Document 1 includes a valve body actuation time detection unit that detects the valve body actuation time of the fuel injection valve, and a fuel injection quantity correction unit that corrects the fuel injection quantity based on the valve body actuation time information.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2019 / 225076 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in solenoid valve drive devices such as the valve body actuation time detection unit in Patent Document 1, which includes a valve closing detection unit for detecting the closing of the fuel injection valve, if the valve closing detection unit or the fuel injection valve malfunctions, even if fuel injection can be performed, optimal flow control may be difficult to achieve. Therefore, it is preferable to have the ability to detect malfunctions in the valve closing detection unit, etc.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to enable the use of a solenoid valve drive device equipped with a valve closure detection unit to determine the fault of the valve closure detection unit, etc.

[0009] means for solving problems

[0010] As a means to solve the above-mentioned problems, the present invention adopts the following structure.

[0011] The first aspect of the present invention adopts the following structure: the solenoid valve driving device includes: a driving circuit that drives the fuel injection valve by energizing the coil of the fuel injection valve; a valve closing detection unit that detects the valve closing timing of the valve body of the fuel injection valve based on the voltage value of the coil; and a fault detection unit that determines a fault based on the coil voltage value read in the valve closing detection unit.

[0012] Invention Effects

[0013] In the solenoid valve drive device of the present invention, the fault detection unit determines a fault based on the coil voltage value read from the valve closure detection unit. When any one of the drive circuit, the valve closure detection unit, or the fuel injection valve malfunctions, the coil voltage value read from the valve closure detection unit changes compared to its normal, fault-free state. That is, in the case of a fault, the coil voltage value read from the valve closure detection unit becomes unstable. Therefore, by using the coil voltage value read from the valve closure detection unit, the fault detection unit can determine whether a fault has occurred. Therefore, in the solenoid valve drive device of the present invention, a fault in the valve closure detection unit, etc., can be determined using a solenoid valve drive device equipped with a valve closure detection unit. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a fuel injection valve controlled by the solenoid valve drive device in the first embodiment of the present invention.

[0015] Figure 2 This is a schematic structural diagram of the solenoid valve driving device in the first embodiment of the present invention.

[0016] Figure 3 This is a timing diagram showing the relationship between the coil voltage value, the count value of the abnormality monitoring counter, and the count value of the abnormality counter in the first embodiment of the present invention.

[0017] Figure 4 This is a timing diagram showing the relationship between the count value of the anomaly monitoring counter, the count value of the anomaly counter, and the fault determination flag in the first embodiment of the present invention.

[0018] Figure 5 This is a timing diagram showing the relationship between the coil voltage value, the count value of the abnormality monitoring counter, and the count value of the abnormality counter in the second embodiment of the present invention.

[0019] Figure 6 This is a timing diagram showing the relationship between the coil voltage value of the valve closing timing, the count value of the abnormal monitoring counter, the count value of the abnormal counter, and the fault determination flag in the fourth embodiment of the present invention.

[0020] Figure 7 This is a timing diagram showing the relationship between the coil voltage value, the count value of the abnormal monitoring counter, the count value of the abnormal counter, and the fault determination flag during a certain period after the start-up drive device in the fourth embodiment of the present invention.

[0021] Figure 8 This is a flowchart illustrating the fault determination method of the fault detection unit of the solenoid valve drive device in the fifth embodiment of the present invention. Detailed Implementation

[0022] Hereinafter, an embodiment of the solenoid valve drive device of the present invention will be described with reference to the accompanying drawings.

[0023] (First Implementation)

[0024] Figure 1 This is a schematic diagram showing the general structure of the fuel injection valve 100 controlled by the solenoid valve drive device 1 of this embodiment. The solenoid valve drive device 1 of this embodiment is a device that drives the fuel injection valve 100. Specifically, the solenoid valve drive device 1 of this embodiment drives the fuel injection valve 100 (solenoid valve) that injects fuel into the internal combustion engine mounted in the vehicle.

[0025] The fuel injection valve 100 is a solenoid valve (solenoid valve) that injects fuel into an internal combustion engine such as a gasoline engine or a diesel engine installed in a vehicle. Figure 1 This is a schematic structural diagram of the fuel injection valve 100. Figure 1 As shown, the fuel injection valve 100 includes a fixed core 101, a valve seat 102, an electromagnetic coil 103 (coil), a needle 104, a valve body 105, a retainer 106, a lower stopper 107, a valve body force spring 108, a movable core 109, and a movable core force spring 110. In this embodiment, the fixed core 101, valve seat 102, and electromagnetic coil 103 are fixed components. The needle 104, valve body 105, retainer 106, lower stopper 107, valve body force spring 108, movable core 109, and movable core force spring 110 are movable components.

[0026] The retaining core 101 is a cylindrical component that is fixed to the housing (not shown) of the fuel injection valve 100. The retaining core 101 is formed of a magnetic material. The valve seat 102 is fixed to the housing of the fuel injection valve 100. The valve seat 102 has an injection hole 102a. The injection hole 102a is a hole for injecting fuel and is closed when the valve body 105 is seated on the valve seat 102, and is opened when the valve body 105 is separated from the valve seat 102.

[0027] The solenoid coil 103 is formed by winding an electric wire into a loop. The solenoid coil 103 and the fixed core 101 are arranged concentrically. The solenoid coil 103 is electrically connected to the solenoid valve drive device 1. The solenoid coil 103 forms a magnetic circuit including the fixed core 101 and the movable core 109 by energizing the solenoid valve drive device 1.

[0028] The needle 104 is an elongated rod-shaped component extending along the central axis of the fixed core 101. The needle 104 moves in the axial direction (the direction of extension of the needle 104) of the central axis of the fixed core 101 by the attraction generated by the magnetic circuit including the fixed core 101 and the movable core 109.

[0029] Furthermore, the mounting position of the fuel injection valve 100 is not particularly limited. However, in the following description, the direction in which the movable core 109 moves due to the aforementioned attractive force along the axial direction of the central axis of the fixed core 101 is referred to as upward, and the direction opposite to the direction in which the movable core 109 moves due to the aforementioned attractive force is referred to as downward.

[0030] A valve body 105 is formed at the lower front end of the needle 104. The valve body 105 closes the injection orifice 102a by sitting on the valve seat 102 and opens the injection orifice 102a by separating from the valve seat 102. The retainer 106 includes a guide member 106a and a flange 106b. The guide member 106a is a cylindrical member fixed to the upper front end of the needle 104. The flange 106b is formed to project radially toward the needle 104 from the upper end of the guide member 106a. The lower end face of the flange 106b is the contact surface with the movable core force spring 110. In addition, the upper end face of the flange 106b is the contact surface with the valve body force spring 108.

[0031] The lower limiter 107 is a cylindrical component of the needle 104 that is fixed between the valve seat 102 and the guide member 106a. The upper end face of the lower limiter 107 is the contact surface with the movable core 109.

[0032] The valve body force spring 108 is a compression helical spring housed inside the fixed core 101 and inserted between the inner wall of the housing and the flange 106b. The valve body force spring 108 applies a downward force to the valve body 105. That is, when the solenoid coil 103 is not energized, the valve body 105 abuts against the valve seat 102 due to the force of the valve body force spring 108.

[0033] A movable core 109 is disposed between the guide member 106a and the lower limiter 107. The movable core 109 is a cylindrical component, coaxially arranged with the needle 104. The movable core 109 has a through hole formed in its center for the needle 104 to pass through, allowing it to move along the extension direction of the needle 104. The upper end face of the movable core 109 is a contact surface that abuts against the fixed core 101 and the movable core force spring 110. On the other hand, the lower end face of the movable core 109 is a contact surface that abuts against the lower limiter 107. The movable core 109 is made of a magnetic material.

[0034] The movable core force spring 110 is a compression helical spring inserted between the flange 106b and the movable core 109. The movable core force spring 110 applies a downward force to the movable core 109. That is, when the electromagnetic coil 103 is not energized, the movable core 109 abuts against the lower limit device 107 by the force of the movable core force spring 110.

[0035] Next, the solenoid valve drive device 1 according to this embodiment will be described. Figure 2 This is a schematic structural diagram of the solenoid valve drive device 1 according to this embodiment. Figure 2 As shown, the solenoid valve drive device 1 includes a drive device 2 (drive circuit) and a control device 3.

[0036] The drive unit 2 is a circuit that drives the fuel injection valve 100 by energizing the coil, i.e., the solenoid coil 103, of the fuel injection valve 100. For example... Figure 2 As shown, the drive unit 2 includes a power supply unit 2a and a switch 2b. The power supply unit 2a includes at least one of a battery and a boost circuit. The battery is mounted in the vehicle. The boost circuit boosts the output voltage of the battery, i.e., the battery voltage, and outputs the boosted voltage, i.e., the boosted voltage.

[0037] The power supply device 2a can also energize the solenoid coil 103 by outputting battery voltage to it. Alternatively, the power supply device 2a can energize the solenoid coil 103 by outputting a boost voltage. The voltage output from the power supply device 2a to the solenoid coil 103 is controlled by the control device 3. Furthermore, the energizing of the solenoid coil 103 is controlled by the control device 3.

[0038] Switch 2b is controlled by control device 3 to be in an ON or OFF state. When switch 2b is in the ON state, the voltage output from power supply device 2a is supplied to solenoid coil 103. This initiates energization of solenoid coil 103. When switch 2b is in the OFF state, the voltage supply from power supply device 2a to solenoid coil 103 is stopped. This stops energizing solenoid coil 103.

[0039] The control device 3 includes a voltage detection unit 3a and a control processing unit 3b. The voltage detection unit 3a detects the voltage (coil voltage) generated in the solenoid coil 103. For example, the coil voltage is the voltage across the two ends of the solenoid coil 103. The voltage detection unit 3a outputs a signal indicating the detected coil voltage value (coil voltage value) to the control processing unit 3b.

[0040] The control processing unit 3b includes a valve closure detection unit 3c, a power-on control unit 3d, a power-on correction unit 3e, a storage unit 3f, and a fault detection unit 3g. The valve closure detection unit 3c detects the closure of the valve body 105. Specifically, the valve closure detection unit 3c detects the valve closure timing of the valve body 105 of the fuel injection valve 100. The valve closure detection unit 3c reads the coil voltage value input from the voltage detection unit 3a and detects the closure of the fuel injection valve 100 based on the coil voltage value.

[0041] As an example, the valve closure detection unit 3c detects the valve closure of the valve body 105 by detecting the inflection point of the coil voltage value. However, the valve closure detection unit 3c detects the valve closure of the valve body 105 by detecting the inflection point of the processed voltage value obtained by processing the coil voltage value. The processed voltage can also be the differential value of the coil voltage value. In addition, the coil voltage value used to detect the valve closure of the valve body 105 can also have high-frequency components removed by a filter.

[0042] The power supply control unit 3d controls the power supply device 2a. The power supply control unit 3d controls the switch 2b to either an on or off state. When the power supply control unit 3d controls the switch 2b to the on state, it energizes the solenoid coil 103. When the power supply control unit 3d controls the switch 2b to the off state, it stops energizing the solenoid coil 103. The power supply control unit 3d controls the energizing period based on the program stored in the storage unit 3f and the subsequent corrected energizing period calculated by the energizing period correction unit 3e (described later).

[0043] The solenoid valve drive device 1 is based on a cycle period Ts (refer to) set for one fuel injection by the fuel injection valve 100. Figure 3 The solenoid valve actuator 1 controls the fuel injection valve 100. Specifically, the cycle Ts repeats continuously over time. The solenoid valve actuator 1 causes the fuel injection valve 100 to inject fuel during each cycle Ts. In addition, the solenoid valve actuator 1 can also be controlled to prevent the fuel injection valve 100 from injecting fuel during a cycle Ts.

[0044] The solenoid valve drive unit 1 controls the flow rate of fuel injected from the fuel injection valve 100 by controlling the energizing period of each repetitive cycle Ts. An energizing period represents the duration during which the solenoid coil 103 is energized within one cycle Ts. The energizing period is the time from the start of energizing the solenoid coil 103 to the stop of energizing. The control unit 3 controls the injection quantity (fuel injection amount) of fuel injected from the fuel injection valve 100 by controlling this energizing period.

[0045] The solenoid valve drive device 1 of this embodiment performs multi-stage injection control, causing the fuel injection valve 100 to inject fuel more than once, for example, during one combustion cycle of an internal combustion engine (e.g., a cycle consisting of one intake stroke, one compression stroke, one combustion stroke, and one exhaust stroke in sequence). In this embodiment, the fuel injection valve 100 performs two fuel injections in one combustion cycle. That is, one combustion cycle includes two cycle periods Ts. However, the number of fuel injections in one combustion cycle can be varied. For example, the first fuel injection in the two fuel injections performed in one combustion cycle is called the initial injection. The next fuel injection is called the final injection.

[0046] The power-on period correction unit 3e corrects the power-on period, for example, based on the correction amount mapping M stored in the storage unit 3f. The power-on period correction unit 3e calculates the correction amount, for example, based on the valve closing timing, by referring to the correction amount mapping M.

[0047] Furthermore, the energizing period correction unit 3e corrects the energizing period based on the calculated correction amount. The corrected energizing period is input to the energizing control unit 3d. The energizing control unit 3d energizes the solenoid coil 103 based on the corrected energizing period. In addition, in this embodiment, the energizing period correction unit 3e monitors the period Tk (see below) during the monitoring period. Figure 4 Corrections during the period when power is suspended.

[0048] Storage unit 3f stores the aforementioned correction amount mapping M. The correction amount mapping M represents the relationship between the difference between the detected valve closing timing and the control valve closing timing, and the correction amount during energization. Additionally, in this embodiment, storage unit 3f stores the high-voltage side threshold VH (refer to...). Figure 3 The high-voltage side threshold VH is a threshold set in such a way that the coil voltage exceeds the threshold value during normal fuel injection within the cycle period Ts. That is, if it is normal fuel injection, the coil voltage exceeds the high-voltage side threshold VH during the cycle period Ts. In addition, the storage unit 3f stores the drive control program of the fuel injection valve 100 and various calculated values.

[0049] The fault detection unit 3g determines a fault based on the coil voltage value read from the valve closure detection unit 3c. In this embodiment, the fault detection unit 3g determines an anomaly if the coil voltage value during the cycle Ts does not exceed the high-voltage side threshold VH. On the other hand, the fault detection unit 3g determines a normal operation if the coil voltage value during the cycle Ts exceeds the high-voltage side threshold VH. When the fault detection unit 3g determines an anomaly, it increments the anomaly counter by 1. Conversely, when the fault detection unit 3g determines a normal operation, it maintains the anomaly counter's count.

[0050] For example, the fault detection unit 3g activates a timing flag when the coil voltage exceeds the high-voltage side threshold VH. Furthermore, if the aforementioned flag is not activated at the end of the cycle (Ts) or when the coil voltage becomes zero, the fault detection unit 3g determines it to be abnormal.

[0051] When incrementing the count value of the fault counter, the fault detection unit 3g may, for example, increment the count value at the time when the loop period Ts ends. Alternatively, the fault detection unit 3g may, for example, increment the count value at the time when the coil voltage value becomes zero.

[0052] Furthermore, the fault detection unit 3g performs fault determination based on the count value of the abnormality (the count value of the abnormality counter) determined as described above. Specifically, the fault detection unit 3g determines the fault when the count value of the abnormality counter exceeds the fault determination value Cx (refer to...). Figure 4 In cases where the fault detection unit 3g detects an abnormality and determines that a fault has occurred, it activates a fault determination flag and determines that a fault has occurred. Furthermore, the fault determination value Cx is preset based on experiments and simulations and stored in the storage unit 3f.

[0053] In this embodiment, when an anomaly occurs while the anomaly counter's count value is zero, the fault detection unit 3g begins a monitoring period Tk (refer to...) for a predetermined period of time. Figure 4 The fault detection unit 3g starts increasing the count value of the fault monitoring counter when an anomaly occurs and the count value of the anomaly counter is zero. During each cycle Ts, the fault detection unit 3g increases the count value of the anomaly monitoring counter until it reaches the upper limit value Cmax (refer to...). Figure 4 The monitoring period is set to Tk up to this point. In addition, the upper limit value Cmax is set in advance based on experiments and simulations and stored in storage unit 3f.

[0054] The fault detection unit 3g resets the count value of the anomaly counter to zero after the monitoring period Tk has elapsed. That is, if the count value of the anomaly counter does not exceed the fault determination value Cx during the monitoring period Tk, the fault detection unit 3g sets the count value of the anomaly counter to zero.

[0055] Thus, during the monitoring period Tk, after the fault detection unit 3g determines that an anomaly has occurred when the anomaly counter count value is zero, the monitoring period begins. If the anomaly counter count value exceeds the predetermined fault determination value Cx, a fault is determined to have occurred.

[0056] In this embodiment, the solenoid valve drive device 1 controls the energizing period of the solenoid coil 103 by controlling the switch 2b of the drive device 2 via the energizing control unit 3d of the control device 3. When the solenoid coil 103 is energized, the valve body 105 of the fuel injection valve 100 opens the injection orifice 102a, and fuel is injected from the fuel injection valve 100. Furthermore, the control device 3 uses the valve closing detection unit 3c to detect the valve closing timing based on the detection result (coil voltage value) of the voltage detection unit 3a. Additionally, the energizing period is adjusted as needed based on the valve closing timing.

[0057] Next, refer to Figure 3 and Figure 4 An example of an operation related to fault determination of the solenoid valve drive device 1 in this embodiment will be described. Figure 3It is a timing diagram that shows the relationship between the coil voltage value, the count value of the abnormal monitoring counter, and the count value of the abnormal counter. Figure 4 It is a timing diagram that shows the relationship between the count value of the anomaly monitoring counter, the count value of the anomaly counter, and the fault determination flag.

[0058] Additionally, the count values ​​of the exception counter and the exception monitoring counter increase by one during each cycle (Ts), thus increasing in stages. However, in... Figure 4 In the process, because the width of Ts is small during the loop, the count values ​​of the exception counter and the exception monitoring counter are shown as increasing continuously (i.e., the increase is sloping).

[0059] like Figure 3 As shown, the coil voltage value varies during one cycle Ts. Under normal injection conditions, the coil voltage value increases when switch 2b is connected and decreases when switch 2b is disconnected. At this time, the coil voltage value exceeds the high-voltage side threshold VH and then increases, and then decreases.

[0060] When the coil voltage exceeds the high-voltage side threshold VH during the cycle Ts, the fault detection unit 3g does not change the count value of the fault counter. That is, when the fault counter count value is zero, the fault counter count value is maintained at zero even if the coil voltage exceeds the high-voltage side threshold VH during the cycle Ts.

[0061] On the other hand, when the coil voltage value during cycle Ts does not exceed the high-voltage side threshold VH, the fault detection unit 3g increments the abnormality counter by 1. Additionally, when the abnormality counter is at zero, the abnormality monitoring counter also increments if the coil voltage value during cycle Ts does not exceed the high-voltage side threshold VH. Once the fault detection unit 3g begins incrementing the abnormality monitoring counter, as... Figure 4 As shown, during each cycle Ts, the count value of the anomaly monitoring counter is increased until the count value of the anomaly monitoring counter exceeds the upper limit Cmax. The period from when the count value of the anomaly monitoring counter starts increasing until it exceeds the upper limit Cmax is called the monitoring period Tk.

[0062] If, before the monitoring period Tk (i.e., before the anomaly monitoring counter exceeds the upper limit Cmax), the fault detection unit 3g detects a fault if the anomaly counter exceeds the fault determination value Cx. Figure 4 As shown, the fault determination flag is activated. That is, if the count value of the anomaly counter exceeds the fault determination value Cx before the monitoring period Tk has elapsed, the fault detection unit 3g determines that a fault has occurred.

[0063] In contrast, if the fault detection unit 3g, before the monitoring period Tk (i.e., before the count value of the anomaly monitoring counter exceeds the upper limit Cmax), does not exceed the fault determination value Cx, then... Figure 4 As shown, the count value of the exception counter is set to zero.

[0064] Thus, in this embodiment, if Tk frequently malfunctions during the monitoring period, the fault detection unit 3g determines that a fault has occurred. On the other hand, if the number of malfunctions generated by Tk during the monitoring period is small, the fault detection unit 3g assumes it is a false alarm and sets the count value of the malfunction counter to zero.

[0065] Furthermore, if the fault detection unit 3g determines that a fault has occurred, the control device 3 inputs a signal indicating this situation to the upper-level control device. This allows, for example, notification to the vehicle's user about the possibility of a fault.

[0066] If the fault detection unit 3g determines that a fault has occurred, it indicates that any one of the following components has malfunctioned: fuel injection valve 100, drive unit 2, voltage detection unit 3a, valve closure detection unit 3c, and energization control unit 3d. Furthermore, even if the voltage detection unit 3a or the valve closure detection unit 3c malfunctions, there is a possibility that fuel injection from the fuel injection valve 100 may still occur appropriately. That is, the fault detection unit 3g's determination of a fault does not necessarily mean that immediate fuel injection from the fuel injection valve 100 is inappropriate.

[0067] Furthermore, in this embodiment, during the monitoring period Tk (i.e., when the count value of the abnormal monitoring counter is not zero), the power-on period correction unit 3e stops the power-on period correction. During the monitoring period Tk, there is a possibility of a malfunction occurring. By stopping the power-on period correction during a period when there is a possibility of such a malfunction, the possibility of determining a malfunction based on the power-on period correction can be reduced.

[0068] The solenoid valve drive device 1 of this embodiment, as described above, includes a drive device 2, a valve closing detection unit 3c, and a fault detection unit 3g. The drive device 2 drives the fuel injection valve 100 by energizing the solenoid coil 103. The valve closing detection unit 3c detects the valve closing timing of the valve body 105 of the fuel injection valve 100 based on the voltage value of the solenoid coil 103, i.e., the coil voltage value. The fault detection unit 3g determines a fault based on the coil voltage value read from the valve closing detection unit 3c.

[0069] In the solenoid valve drive device 1 of this embodiment, the fault detection unit 3g determines a fault based on the coil voltage value read from the valve closure detection unit 3c. The coil voltage value read from the valve closure detection unit 3c changes relative to its normal state when any one of the drive device 2, the valve closure detection unit 3c, or the fuel injection valve 100 malfunctions. That is, in the case of a fault, the coil voltage value read from the valve closure detection unit 3c becomes unstable. Therefore, by reading the coil voltage value from the valve closure detection unit 3c, the fault detection unit 3g can determine whether a fault has occurred. Thus, the solenoid valve drive device 1 of this embodiment can determine faults in the valve closure detection unit 3c, etc.

[0070] Furthermore, in the solenoid valve drive device 1 of this embodiment, a high-voltage side threshold VH is set. This high-voltage side threshold VH is set such that the coil voltage value exceeds this high-voltage side threshold VH during normal fuel injection in cycle Ts. The fault detection unit 3g determines an anomaly if the coil voltage value does not exceed the high-voltage side threshold VH during cycle Ts. Additionally, the fault detection unit 3g determines the fault based on the anomaly count.

[0071] The solenoid valve drive device 1 of this embodiment performs fault determination based on a high-voltage side threshold VH. The high-voltage side threshold VH is set to the value that the coil voltage exceeds under normal fuel injection conditions. By using this high-voltage side threshold VH, the solenoid valve drive device 1 of this embodiment can easily and reliably determine faults.

[0072] Furthermore, in the solenoid valve drive device 1 of this embodiment, the fault detection unit 3g determines that a fault has occurred if the count value of the abnormality exceeds a predetermined fault determination value Cx during the monitoring period Tk. The monitoring period Tk is a certain period that begins after an abnormality is determined when the count value of the abnormality is zero.

[0073] In this embodiment, the solenoid valve drive device 1 is determined to have malfunctioned if Tk abnormalities occur frequently during monitoring. Therefore, the solenoid valve drive device 1 of this embodiment can suppress situations where a single occurrence due to some reason is mistakenly identified as a malfunction due to abnormal false detection.

[0074] Furthermore, in the solenoid valve drive device 1 of this embodiment, if the count value of the abnormality within the monitoring period Tk does not exceed the fault determination value Cx, the fault detection unit 3g sets the count value of the abnormality to zero.

[0075] According to this embodiment of the solenoid valve drive device 1, after the monitoring period Tk, the count value of the abnormality becomes zero. Therefore, the solenoid valve drive device 1 of this embodiment can only determine the situation where the abnormality is concentrated in a predetermined certain period, namely the monitoring period Tk, as a fault.

[0076] Furthermore, the solenoid valve drive device 1 of this embodiment includes an energization control unit 3d for setting the energization period of the solenoid coil 103 and an energization period correction unit 3e for correcting the energization period. Additionally, the energization period correction unit 3e stops correcting the energization period during the monitoring period Tk.

[0077] In the solenoid valve drive device 1 of this embodiment, during the monitoring period Tk, the power-on period correction unit 3e stops the power-on period correction. By stopping the power-on period correction during a period when there is a possibility of such a fault occurring, the possibility of a fault being determined to have occurred based on the power-on period correction can be reduced.

[0078] (Second Implementation)

[0079] Next, refer to Figure 5 The second embodiment of the present invention will now be described. Furthermore, in this embodiment, the descriptions of parts identical to those in the first embodiment described above will be omitted or simplified.

[0080] Figure 5 This is a timing diagram showing the relationship between the coil voltage value, the count value of the anomaly monitoring counter, and the count value of the anomaly counter in this embodiment. In addition to the high-voltage side threshold VH, the storage unit 3f also stores the low-voltage side threshold VL (refer to...). Figure 5 The low-voltage side threshold VL is set such that the coil voltage value exceeding the high-voltage side threshold VH during normal fuel injection decreases during the same cycle period Ts.

[0081] In this embodiment, the fault detection unit 3g determines an anomaly if the coil voltage value exceeds the high-voltage side threshold VH and fails to decrease to the low-voltage side threshold VL during the cycle period Ts. In other words, if the coil voltage value exceeding the high-voltage side threshold VH does not fall below the low-voltage side threshold VL within a predetermined period (cycle period Ts), the fault detection unit 3g determines an anomaly. Conversely, if the coil voltage value exceeds the high-voltage side threshold VH and decreases to the low-voltage side threshold VL during the cycle period Ts, the fault detection unit 3g determines a normal operation.

[0082] For example, the fault detection unit 3g activates a timing flag when the coil voltage exceeds the high-voltage side threshold VH. Then, the fault detection unit 3g lowers the flag when the voltage drops to the low-voltage side threshold VL. If the fault detection unit 3g determines an abnormality if the flag does not decrease at the end of the cycle Ts or when the coil voltage becomes zero.

[0083] like Figure 5 As shown, if the coil voltage value of the fault detection unit 3g exceeds the high-voltage side threshold VH and then falls below the low-voltage side threshold VL during the cycle Ts, the count value of the fault counter will not change. That is, when the count value of the fault counter is zero, if the coil voltage value exceeds the high-voltage side threshold VH and then falls below the low-voltage side threshold VL during the cycle Ts, the count value of the fault counter will be maintained at zero.

[0084] On the other hand, if the coil voltage value exceeds the high-voltage side threshold VH but does not fall below the low-voltage side threshold VL during the cycle Ts, the fault detection unit 3g increments the abnormality counter by 1. Additionally, if the abnormality counter is zero, and the coil voltage value exceeds the high-voltage side threshold VH but does not fall below the low-voltage side threshold VL during the cycle Ts, the abnormality monitoring counter also increments. If the abnormality counter's count exceeds the fault determination value Cx before the monitoring period Tk has elapsed, the fault detection unit 3g determines that a fault has occurred.

[0085] In this embodiment as described above, a high-voltage side threshold VH and a low-voltage side threshold VL are set. The low-voltage side threshold VL is set such that, during normal fuel injection, the coil voltage value exceeding the high-voltage side threshold VH decreases within the same cycle period Ts. In the solenoid valve drive device 1 of this embodiment, if, during the cycle period Ts, the coil voltage value exceeding the high-voltage side threshold VH does not fall below the low-voltage side threshold within a predetermined period, the fault detection unit 3g determines an anomaly. Furthermore, the fault detection unit 3g determines the fault based on the anomaly count value.

[0086] The solenoid valve drive device 1 of this embodiment performs fault determination based on a high-voltage side threshold VH and a low-voltage side threshold VL. The high-voltage side threshold VH is set to the value that the coil voltage exceeds under normal fuel injection conditions. The low-voltage side threshold VL is set to the value at which the coil voltage decreases during the same cycle period Ts after exceeding the high-voltage side threshold VH under normal fuel injection conditions. By using these high-voltage side thresholds VH and VL, the solenoid valve drive device 1 of this embodiment can easily and reliably determine faults.

[0087] (Third Implementation)

[0088] Next, refer to Figure 6 The third embodiment of the present invention will now be described. Furthermore, in the description of this embodiment, parts that are the same as those in the first embodiment described above will be omitted or simplified.

[0089] Figure 6 This is a timing diagram showing the relationship between the coil voltage value of the valve closing timing, the count value of the abnormality monitoring counter, the count value of the abnormality counter, and the fault determination flag in this embodiment. The storage unit 3f stores the normal voltage value range VS1 of the valve closing timing. The normal voltage value range VS1 is preset to include the range of coil voltage values ​​that may exist during valve closing timing under normal fuel injection conditions.

[0090] In this embodiment, when the valve closing detection unit 3c detects that the coil voltage value for valve closing timing is not within the normal voltage range VS1 during the cycle Ts, the fault detection unit 3g determines it to be abnormal. That is, if the coil voltage value is not within the preset normal voltage range VS1 during valve closing timing, the fault detection unit 3g determines it to be abnormal. On the other hand, if the coil voltage value is within the preset normal voltage range VS1 during the cycle Ts and valve closing timing, the fault detection unit 3g determines it to be normal.

[0091] For example, the fault detection unit 3g activates a flag when the valve closing timing coil voltage is not within the preset normal voltage range VS1. When the timing flag at the end of the cycle time period Ts is activated, the fault detection unit 3g determines that a fault has occurred.

[0092] like Figure 6 As shown, the fault detection unit 3g does not change the count value of the fault counter when the coil voltage value during valve closing timing is within the normal voltage range VS1. That is, when the count value of the fault counter is zero, and the coil voltage value during valve closing timing is within the normal voltage range VS1, the count value of the fault counter is maintained at zero.

[0093] On the other hand, when the coil voltage value during valve closing timing is not within the normal voltage range VS1, the fault detection unit 3g increments the fault counter by 1. Additionally, when the fault counter is zero, and the coil voltage value during valve closing timing is not within the normal voltage range VS1, the fault monitoring counter also increments. If, before the monitoring period Tk has elapsed, the fault counter value exceeds the fault determination value Cx, the fault detection unit 3g determines that a fault has occurred.

[0094] In this embodiment as described above, the normal voltage range VS1 for the valve closing timing is predetermined. In the solenoid valve drive device 1 of this embodiment, if the coil voltage value is not within the normal voltage range VS1 during the valve closing timing, the fault detection unit 3g determines it to be abnormal. Furthermore, fault determination is performed based on the abnormal count value.

[0095] The solenoid valve drive device 1 of this embodiment performs fault determination based on the normal voltage range VS1 of the valve closing timing. The normal voltage range VS1 of the valve closing timing is set to the coil voltage value that exists during normal fuel injection. By using such a normal voltage range VS1 of the valve closing timing, the solenoid valve drive device 1 of this embodiment can easily and reliably determine faults.

[0096] (Fourth Implementation)

[0097] Next, refer to Figure 7 The fourth embodiment of the present invention will now be described. Furthermore, in the description of this embodiment, parts that are the same as those in the first embodiment described above will be omitted or simplified.

[0098] Figure 7 This is a timing diagram showing the relationship between the coil voltage value, the count value of the fault monitoring counter, the count value of the fault counter, and the fault determination flag during a certain period starting from the start-drive device 2 in this embodiment. The storage unit 3f stores the normal voltage value range VS2 during a certain period starting from the start-drive device 2. For example, when the vehicle's ignition switch changes from the off state to the on state, the drive device 2 starts, and the internal combustion engine, supplied with fuel by the fuel injection valve 100, starts. That is, a certain period starting from the start-drive device 2 (the initial start-up period) becomes the initial operating period of the internal combustion engine. During this initial start-up period, instead of fuel injection corresponding to the vehicle's accelerator operation, a predetermined amount of fuel is injected from the fuel injection valve 100. In this embodiment, such an initial start-up period is used to determine faults. The normal voltage value range VS2 is preset to include the range of coil voltage values ​​that may exist under normal fuel injection conditions during the initial start-up period.

[0099] In this embodiment, the fault detection unit 3g determines an anomaly if the coil voltage value is not within the normal voltage range VS2 during the initial startup period. On the other hand, the fault detection unit 3g determines a normal operation if the coil voltage value is within the preset normal voltage range VS2 during the initial startup period.

[0100] For example, when the initial start-up period begins (the ignition switch changes from the off state to the on state), the fault detection unit 3g increases the count value of the abnormality monitoring counter. If the coil voltage value is not within the preset normal voltage range VS2 during this initial start-up period, the fault detection unit 3g increases the count value of the abnormality counter.

[0101] like Figure 7 As shown, the fault detection unit 3g does not change the count value of the fault counter when the coil voltage value is within the normal voltage range VS2 during the initial startup period. That is, during the initial startup period, when the coil voltage value is within the normal voltage range VS2, the count value of the fault counter is maintained at zero.

[0102] On the other hand, when the initial start-up period begins (the ignition switch changes from the off state to the on state), the fault detection unit 3g increments the count value of the abnormality monitoring counter. During the period when the abnormality monitoring counter is incrementing, if the coil voltage value is not within the normal voltage range VS2, the abnormality counter count value is also incremented. Furthermore, even if the coil voltage value is not within the normal voltage range VS2, the fault detection unit 3g still increments the abnormality monitoring counter count value. If the abnormality counter count value exceeds the fault determination value Cx before the initial start-up period has elapsed, the fault detection unit 3g determines that a fault has occurred.

[0103] In this embodiment described above, the normal voltage range VS2 is predetermined during the initial startup period. In the solenoid valve drive device 1 of this embodiment, the fault detection unit 3g determines an anomaly if the coil voltage value is not within the normal voltage range VS2 during the initial startup period. Furthermore, a fault determination is made based on the anomaly count value.

[0104] In this embodiment, the solenoid valve drive device 1 performs fault determination based on the normal voltage value range VS2 during the initial startup period. During the initial startup period, the normal voltage value range VS2 is set to the coil voltage value present during normal fuel injection. By using this normal voltage value range VS2 during the initial startup period, the solenoid valve drive device 1 of this embodiment can easily and reliably determine faults.

[0105] (Fifth Implementation)

[0106] Next, refer to Figure 8 The fifth embodiment of the present invention will now be described. Furthermore, in this embodiment, the descriptions of parts identical to those in the first to fourth embodiments described above are omitted or simplified.

[0107] Figure 8This is a flowchart illustrating the fault determination method in the fault detection unit 3g of the solenoid valve drive device 1 according to this embodiment. As shown in the figure, the fault detection unit 3g performs anomaly determination processing based on a first condition (step S1) and anomaly determination processing based on a second condition (step S2).

[0108] The anomaly detection process based on the first condition is, for example, a process of anomaly detection based on any of the methods described in the first to fourth embodiments described above. That is, the fault detection unit 3g performs anomaly detection processing based on the first condition using any of the following methods: the method for determining anomalies based on the coil voltage value and the high-voltage side threshold VH described in the first embodiment; the method for determining anomalies based on the coil voltage value, the high-voltage side threshold VH, and the low-voltage side threshold VL described in the second embodiment; the method for determining anomalies based on the coil voltage value during valve closing timing and the normal voltage value range VS1 described in the third embodiment; and the method for determining anomalies based on the coil voltage value during the initial start-up period and the normal voltage value range VS2 described in the fourth embodiment.

[0109] The anomaly determination process based on the second condition is, for example, a step of performing anomaly determination using a method not used in the anomaly determination process based on the first condition, as described in the anomaly determination methods in the first to fourth embodiments above.

[0110] Furthermore, in the anomaly detection process based on the first condition, the fault detection unit 3g can proceed to either an anomaly determination or a fault determination. Similarly, in the anomaly detection process based on the second condition, the fault detection unit 3g can proceed to either an anomaly determination or a fault determination.

[0111] In addition, such as Figure 8 As shown, the fault detection unit 3g of the solenoid valve drive device 1 in this embodiment performs a determination on whether an anomaly is determined to be abnormal in both the anomaly determination processing based on the first condition and the anomaly determination processing based on the second condition (step S3). Alternatively, step S3 may also be a step of determining whether an anomaly is determined to be abnormal in both the anomaly determination processing based on the first condition and the anomaly determination processing based on the second condition.

[0112] In step S3, if an anomaly is determined in either the anomaly determination process based on the first condition or the anomaly determination process based on the second condition, the fault detection unit 3g determines a fault (step S4). On the other hand, if an anomaly determination process based on either the first condition or the anomaly determination process based on the second condition is determined to be normal, the fault detection unit 3g returns to step S1.

[0113] In the solenoid valve drive device 1 of this embodiment, the fault detection unit 3g determines an anomaly based on multiple conditions using the coil voltage value, and determines a fault as a condition that an anomaly is determined under multiple different conditions. According to the solenoid valve drive device 1 of this embodiment, faults can be detected more accurately.

[0114] Furthermore, this embodiment describes a structure for determining a fault when both the anomaly determination process based on a first condition and the anomaly determination process based on a second condition are deemed abnormal. However, the present invention may also employ a structure in which anomaly determination processes based on three or more conditions are performed, and a fault is determined when multiple of these anomaly determination processes are deemed abnormal.

[0115] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. The shapes, combinations, etc. of the constituent components shown in the above embodiments are examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0116] For example, in the above embodiment, a structure that determines a fault when anomalies occur frequently during the monitoring period Tk has been described. However, the present invention is not limited to this. For example, it is also possible to determine a fault by determining an anomaly only once during the monitoring period Tk, or to determine a fault by determining an anomaly by determining a single anomaly without setting a monitoring period Tk.

[0117] Furthermore, the above-described embodiments can also be described, for example, as in the following notes.

[0118] (Note 1)

[0119] A solenoid valve driving device, comprising:

[0120] The drive circuit drives the fuel injection valve by energizing the coil of the fuel injection valve;

[0121] The valve closure detection unit detects the valve closure timing of the fuel injection valve body based on the voltage value of the coil; and

[0122] The fault detection unit determines the fault based on the coil voltage value read from the valve closure detection unit.

[0123] (Note 2)

[0124] According to the solenoid valve drive device described in Appendix 1, during a cycle set for the fuel injection valve to perform one fuel injection, a high-voltage side threshold is set such that the coil voltage value exceeds the threshold during normal fuel injection.

[0125] The fault detection unit performs:

[0126] During the cycle, an anomaly is determined if the coil voltage value does not exceed the high-voltage side threshold.

[0127] The fault determination is made based on the count value of the anomaly.

[0128] (Note 3)

[0129] According to the solenoid valve drive device described in Appendix 1, during a cycle set for the fuel injection valve to perform one fuel injection, a high-voltage side threshold is set such that the coil voltage value exceeds the threshold during normal fuel injection, and a low-voltage side threshold is set such that the coil voltage value decreases during the same cycle after exceeding the high-voltage side threshold during normal fuel injection.

[0130] The fault detection unit performs:

[0131] During the cycle, if the coil voltage value exceeding the high-voltage side threshold does not fall below the low-voltage side threshold within a predetermined period, it is determined to be abnormal.

[0132] The fault determination is made based on the count value of the anomaly.

[0133] (Note 4)

[0134] According to the solenoid valve drive device described in Appendix 1, the fault detection unit performs the following:

[0135] If, during the valve closing timing, the coil voltage value is outside the preset normal voltage range, an abnormality is determined.

[0136] The fault determination is made based on the count value of the anomaly.

[0137] (Note 5)

[0138] According to the solenoid valve drive device described in Appendix 1, the fault detection unit performs the following:

[0139] If, within a predetermined period starting from the start of the drive circuit, the coil voltage value is not within a predetermined normal voltage range, it is determined to be abnormal.

[0140] The fault determination is made based on the count value of the anomaly.

[0141] (Note 6)

[0142] According to any one of the appendices 2 to 4, during the monitoring period from the time the abnormality is determined to be zero, if the abnormality count exceeds a predetermined fault determination value, the fault detection unit determines that a fault has occurred.

[0143] (Note 7)

[0144] According to any one of the appendices 2 to 6, if the count value of the abnormality does not exceed a predetermined fault determination value within a determined period, the fault detection unit sets the count value of the abnormality to zero.

[0145] (Note 8)

[0146] The solenoid valve drive device according to Appendix 6 or 7 comprises:

[0147] The energizing control unit sets the energizing period for the coil; and

[0148] The power-on period correction unit corrects the power-on period.

[0149] The power-on period correction unit stops the correction during the monitoring period.

[0150] (Note 9)

[0151] According to any one of the appendices 1 to 8, the fault detection unit makes an anomaly determination based on multiple conditions using the coil voltage value, and determines a fault as a condition that an anomaly is determined under multiple different conditions.

[0152] Explanation of reference numerals in the attached figures

[0153] 1 Solenoid valve drive unit; 2 Drive unit; 2a Power supply unit; 2b Switch; 3 Control unit; 3a Voltage detection unit; 3b Control processing unit; 3c Valve closure detection unit; 3d Power-on control unit; 3e Power-on correction unit; 3f Storage unit; 3g Fault detection unit; 100 Fuel injection valve (solenoid valve); 103 Solenoid coil (coil); 105 Valve body.

Claims

1. A solenoid valve driving device, comprising: The drive circuit drives the fuel injection valve by energizing the coil of the fuel injection valve; The valve closure detection unit detects the valve closure timing of the fuel injection valve body based on the voltage value of the coil; and The fault detection unit determines the fault based on the coil voltage value read from the valve closure detection unit.

2. The solenoid valve driving device according to claim 1, wherein, During a cycle designed to enable the fuel injection valve to perform a single fuel injection, a high-voltage side threshold is set such that the coil voltage value exceeds the threshold value during normal fuel injection. The fault detection unit performs: During the cycle, an anomaly is determined if the coil voltage value does not exceed the high-voltage side threshold. The fault determination is made based on the count value of the anomaly.

3. The solenoid valve driving device according to claim 1, wherein, During a cycle designed to enable the fuel injection valve to perform one fuel injection, a high-voltage side threshold is set such that the coil voltage value exceeds the threshold during normal fuel injection, and a low-voltage side threshold is set such that the coil voltage value decreases during the same cycle after exceeding the high-voltage side threshold during normal fuel injection. The fault detection unit performs: During the cycle, if the coil voltage value exceeding the high-voltage side threshold does not fall below the low-voltage side threshold within a predetermined period, it is determined to be abnormal. The fault determination is made based on the count value of the anomaly.

4. The solenoid valve driving device according to claim 1, wherein, The fault detection unit performs: If, during the valve closing timing, the coil voltage value is outside the preset normal voltage range, an abnormality is determined. The fault determination is made based on the count value of the anomaly.

5. The solenoid valve driving device according to claim 1, wherein, The fault detection unit performs: If, within a predetermined period starting from the start of the drive circuit, the coil voltage value is not within a predetermined normal voltage range, it is determined to be abnormal. The fault determination is made based on the count value of the anomaly.

6. The solenoid valve driving device according to any one of claims 2 to 4, wherein, During the monitoring period, which begins from the point when the anomaly count is zero, the fault detection unit determines that a fault has occurred if the anomaly count exceeds a predetermined fault determination value.

7. The solenoid valve driving device according to any one of claims 2 to 5, wherein, If the count of the anomaly does not exceed a predetermined fault determination value within a defined period, the fault detection unit sets the count of the anomaly to zero.

8. The solenoid valve driving device according to claim 6, wherein, have: The energizing control unit sets the energizing period for the coil; and The power-on period correction unit corrects the power-on period. The power-on period correction unit stops the correction during the monitoring period.

9. The solenoid valve drive device according to any one of claims 1 to 5, wherein, The fault detection unit determines anomalies based on multiple conditions using the coil voltage value, and determines a fault as a condition that anomalies are determined under multiple different conditions.

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