Solenoid valve driving device

Abstract

In a solenoid valve drive device, in a first injection mode, an energization period correction unit corrects an energization period by setting a linear relationship between a valve closing timing and a correction amount of the energization period, and in a second injection mode, a valve closing timing is corrected by setting a linear relationship between the valve closing timing and the correction amount of the energization period. The energization period correction unit corrects the energization period on the basis of the relationship between the valve closing timing and the actual energization period during the movement period caused by the rebound of the valve unit.

Description

Technical Field

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

[0002] Patent Document 1 discloses a fuel injection valve control device capable of performing minute fuel injection. The fuel injection valve control device disclosed in Patent Document 1 performs fuel injection of the input target fuel injection amount by lowering the valve body of the solenoid valve towards the closed position during the bounce period before the valve body's bounce ends at the fully open position. Compared to the case where the valve body is moved to the closed position after it has reached a stable open state, this fuel injection valve control device of Patent Document 1 can perform minute fuel injection with high precision.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-137785 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, the solenoid valve drive device disclosed in Patent Document 1, in order to suppress errors caused by individual differences in fuel injection valves, deterioration over time, etc., sometimes includes a valve closing timing detection unit. Such a solenoid valve drive device, for example, detects the actual valve closing timing through the valve closing timing detection unit and calculates the difference between the actual valve closing timing and the controlled valve closing timing. The solenoid valve drive device corrects the energizing period of the coil to the fuel injection valve to eliminate the error in injection quantity caused by this difference.

[0008] When the valve closes after the valve body has reached a stable open state as described above, the correction amount during the energizing period is linearly related to the difference between the actual valve closing timing and the controlled valve closing timing. However, as in Patent Document 1, when the control stops energizing the coil during the movement caused by the rebound of the valve section including the valve body, the difference between the actual valve closing timing and the controlled valve closing timing becomes non-linear. Therefore, similar to the injection mode where the valve closes after reaching a stable open state, if the energizing period is corrected during the movement caused by the rebound of the valve section, the fuel injection quantity cannot be accurately controlled.

[0009] The present invention was made in view of the above-mentioned problems, and its object is to enable the energizing period to be appropriately corrected according to the actual valve closing timing in either the injection mode in which the energizing of the coil is stopped after the valve section becomes a stable open state, or the injection mode in which the energizing of the coil is stopped during the movement caused by the rebound of the valve section.

[0010] Methods for solving problems

[0011] As a means to solve the above-mentioned problems, the present invention adopts the following structure.

[0012] The first aspect of the present invention relates to a solenoid valve driving device for controlling a fuel injection valve. The fuel injection valve includes: a movable core that is attracted in an opening direction by energizing a coil; a valve portion that moves in the opening direction as the movable core moves in that direction; and a force-applying unit that applies force to the valve portion in a closing direction. The solenoid valve driving device includes: a valve closing detection unit that detects the valve closing timing based on the coil voltage value; an energizing period correction unit that corrects the energizing period of the coil based on the valve closing timing; and an energizing control unit that controls the energizing of the coil based on the corrected energizing period. The solenoid valve driving device can control the fuel injection valve based on a first injection mode and a second injection mode. In the first injection mode, after the movement of the valve portion caused by the rebound of the movable core moving in the valve opening direction and abutting against the limiter stops, the coil is kept energized. In the second injection mode, the coil is stopped during the movement caused by the rebound of the valve portion after the movable core moving in the valve opening direction and abutting against the limiter. The energization period correction unit performs the following: in the first injection mode, the correction amount of the valve closing timing and the energization period is set to a linear relationship to correct the energization period; in the second injection mode, the energization period is corrected based on the relationship between the valve closing timing during the movement period caused by the rebound of the valve portion and the actual energization period.

[0013] Invention Effects

[0014] In the fuel injection valve controlled by the solenoid valve drive device of the present invention, the valve portion in the closed state moves toward the limiter along with the movable core in the opening direction. When the movable core collides with the limiter, the valve portion moves away from the movable core due to inertial force, and is then forced back toward the closing direction by the force-applying part. When the rebounding valve portion collides with the movable core, the movable core moves slightly toward the closing direction, and then moves toward the limiter again. As a result, the valve portion reciprocates in the closing and opening directions. That is, the valve portion moves continuously from the moment the movable core comes into contact with the limiter until the end of the reciprocating movement (the movement period caused by the rebound of the valve portion). In contrast, the solenoid valve drive device of the present invention can control the fuel injection valve in a first injection mode that maintains energization of the coil even after the movement caused by the rebound of the valve portion after the movable core moving toward the limiter stops. In this first injection mode, the solenoid valve drive device of the present invention corrects the energizing period by setting the correction amount of the valve closing timing and the energizing period to a linear relationship. Furthermore, the solenoid valve drive device of the present invention can control the fuel injection valve in a second injection mode where energizing of the coil is stopped during the movement period caused by the rebound of the valve portion after the movable core moves in the valve opening direction abuts against the limiter. In this second injection mode, the solenoid valve drive device of the present invention corrects the energizing period based on the relationship between the valve closing timing during the movement period caused by the rebound of the valve portion and the actual energizing period. That is, the present invention corrects the energizing period using different correction methods in the first and second injection modes. Therefore, in the solenoid valve drive device for controlling the fuel injection valve, the present invention can appropriately correct the energizing period according to the actual valve closing timing, even in either the injection mode where energizing of the coil is stopped after the valve portion reaches a stable open state or the injection mode where energizing of the coil is stopped during the movement period caused by the rebound of the valve portion. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a fuel injection valve controlled by the solenoid valve drive device of the first embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the operation of a fuel injection valve controlled by the solenoid valve drive device of the first embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the operation of a fuel injection valve controlled by the solenoid valve drive device of the first embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the operation of a fuel injection valve controlled by the solenoid valve drive device of the first embodiment of the present invention.

[0019] Figure 5 This is a schematic diagram of the operation of a fuel injection valve controlled by the solenoid valve drive device of the first embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram of the operation of a fuel injection valve controlled by the solenoid valve drive device of the first embodiment of the present invention.

[0021] Figure 7 This is a schematic structural diagram of the solenoid valve driving device according to the first embodiment of the present invention.

[0022] Figure 8 It is a graph showing the relationship between the energization period and the valve closing timing of the fuel injection valve.

[0023] Figure 9 This is a schematic structural diagram of the solenoid valve driving device according to the second embodiment of the present invention. Detailed Implementation

[0024] Hereinafter, with reference to the accompanying drawings, one embodiment of the solenoid valve driving device according to the present invention will be described.

[0025] (First Implementation)

[0026] 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.

[0027] 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 (limiter), a valve seat 102, a solenoid coil 103 (coil), a needle 104, a valve body 105, a retainer 106, a lower stopper 107, a valve body force spring 108 (force-applying part), a movable core 109, and a movable core force spring 110. In this embodiment, the fixed core 101, valve seat 102, and solenoid 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.

[0028] The fixing core 101 is a cylindrical component that is fixed to the housing (not shown) of the fuel injection valve 100. The fixing core 101 is formed of a magnetic material. The fixing core 101 functions as a limiter that restricts the movement of the movable core 109 attracted by the solenoid coil 103.

[0029] 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, which is closed when the valve body 105 is seated on the valve seat 102, and opened when the valve body 105 is separated from the valve seat 102.

[0030] 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.

[0031] 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.

[0032] 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 the valve opening direction, and the direction opposite to the direction in which the movable core 109 moves due to the aforementioned attractive force is referred to as the valve closing direction.

[0033] A valve body 105 is formed at the front end of the needle 104 in the closing direction. 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 front end of the needle 104 in the opening direction. The flange 106b is formed such that the end of the guide member 106a in the opening direction protrudes radially toward the needle 104. The end face of the flange 106b in the closing direction is the contact surface with the movable core force spring 110. In addition, the end face of the flange 106b in the opening direction is the contact surface with the valve body force spring 108.

[0034] The lower limiter 107 is a cylindrical component of the needle 104 fixed between the valve seat 102 and the guide member 106a. The end face of the lower limiter 107 in the valve opening direction is the contact surface with the movable core 109.

[0035] 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 force to the valve body 105 in the closing direction. That is, when the solenoid coil 103 is not energized, the valve body 105 abuts against the valve seat 102 by the force of the valve body force spring 108.

[0036] 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 in its center for the needle 104 to pass through, allowing it to move along the extension direction of the needle 104. The end face of the movable core 109 in the opening direction is the contact surface with the fixed core 101 and the movable core force spring 110. On the other hand, the end face of the movable core 109 in the closing direction is the contact surface with the lower limiter 107. The movable core 109 is made of a magnetic material.

[0037] 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 force to the movable core 109 in the direction of valve closure. That is, when the solenoid 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.

[0038] Furthermore, in this embodiment, the needle 104, valve body 105, and retainer 106 move as a single unit by energizing the solenoid coil 103. These integrated needle 104, valve body 105, and retainer 106 constitute the valve section 120. That is, in this embodiment, the valve section 120 having the valve body 105 moves in the valve-opening direction by energizing the solenoid coil 103.

[0039] Such a fuel injection valve 100 is controlled by the solenoid valve drive device 1 of this embodiment based on the three injection modes described later: the first injection mode, the second injection mode, and the third injection mode.

[0040] The first injection mode is an injection mode in which the solenoid coil 103 is kept energized even after the movement of the movable core 109, which moves from the closed valve state (the valve body 105 abuts against the valve seat 102 and closes the injection hole 102a) to the open valve direction, stops due to the springback of the valve part 120 after it abuts against the fixed core 101.

[0041] Reference Figures 2-6 A more detailed explanation of the first injection mode will be provided. Figures 2-6 This is a schematic diagram illustrating the operation of the fuel injection valve 100. In the first injection mode, by... Figure 1 When the solenoid coil 103 is energized in the closed valve state as shown, such as... Figure 2As shown, the movable core 109 moves in the valve opening direction. Then, as... Figure 3 As shown, the movable core 109 abuts against the retainer 106 from the valve-closing direction. Furthermore, by moving the movable core 109 in the valve-opening direction, the valve section 120 moves in the valve-opening direction.

[0042] like Figure 4 As shown, when the movable core 109 collides with the fixed core 101, the movement of the movable core 109 is stopped. On the other hand, the valve section 120 continues to move in the valve opening direction due to inertial force, and the retainer 106 overshoots to a position away from the movable core 109 in the valve opening direction.

[0043] After overshooting, the valve section 120 springs back towards the closing direction due to the force of the valve body spring 108. Figure 5 As shown, it abuts against the movable core 109 from the valve opening direction. Figure 5 As shown, due to the impact force when the valve part 120 collides with the movable core 109, the movable core 109 moves slightly away from the fixed core 101 toward the valve closing direction.

[0044] The movable core 109, slightly away from the fixed core 101 in the valve-closing direction, is attracted again in the valve-opening direction and comes into contact with the fixed core 101 because the solenoid coil 103 is energized. Then, as... Figure 6 As shown, the movable core 109 abuts against the fixed core 101, and the valve part 120 is stable in the state of abutting against the movable core 109.

[0045] Thus, the valve section 120 continuously performs reciprocating movement based on springback until it becomes Figure 6 The process continues until a stable state is achieved. Furthermore, the number of reciprocating movements of the valve section 120 caused by the rebound can be one or more times.

[0046] like Figure 6 As shown, the first injection mode is an injection mode in which the solenoid coil 103 is kept energized for a certain period of time after the movement of the valve section 120 stops and stabilizes due to the rebound, so that the valve section 120 is in the open state for a long time.

[0047] The second injection mode is an injection mode in which energizing the solenoid coil 103 is stopped during the movement caused by the springback of the valve section 120 after the movable core 109 moves from the closed valve state to the open valve state and abuts against the fixed core 101. This second injection mode has a shorter valve opening period and a smaller fuel injection quantity than the first injection mode.

[0048] The second injection mode is during the reciprocating movement caused by the rebound of the valve section 120 as described in the first injection mode (e.g., Figure 4 , Figure 5(As shown in the state) the energization of the solenoid coil 103 is stopped. In addition, if the energization of the solenoid coil 103 is stopped from the time from the valve closed state until the movement stops due to the rebound of the valve section 120 after the movable core 109 collides with the fixed core 101, it becomes the second injection mode.

[0049] The third injection mode is an injection mode in which the energization of the solenoid coil 103 is stopped before the movable core 109, which moves from the closed valve state to the open valve state, comes into contact with the fixed core 101. The valve opening period of this third injection mode is shorter than that of the first and second injection modes, and it is the injection mode with the least fuel injection amount among the three injection modes.

[0050] Next, the solenoid valve drive device 1 of this embodiment will be described. Figure 7 This is a schematic structural diagram of the solenoid valve drive device 1 according to this embodiment. Figure 7 As shown, the solenoid valve drive device 1 includes a drive device 2 and a control device 3.

[0051] 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 7 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.

[0052] The power supply device 2a can also energize the solenoid coil 103 by outputting battery voltage to it. The power supply device 2a can also 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.

[0053] 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.

[0054] 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.

[0055] The control processing unit 3b includes a valve closure detection unit 3c, an energization control unit 3d, an energization period correction unit 3e, and a storage unit 3f. 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. Furthermore, the valve closure timing indicates the time at which the valve closure is detected when the start time of energizing the solenoid coil 103 is set to 0. In other words, the valve closure timing here is the elapsed time from the start of energizing the solenoid coil 103 until the valve closure is detected.

[0056] For example, the valve closure detection unit 3c detects the valve body 105 closing by detecting the inflection point of the coil voltage value. However, the valve closure detection unit 3c detects the valve body 105 closing 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 body 105 closing can also have high-frequency components removed by a filter.

[0057] 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).

[0058] The solenoid valve actuator 1 controls the fuel injection valve 100 based on a cycle period set for one fuel injection. Specifically, the cycle period repeats continuously over time. During each cycle, the solenoid valve actuator 1 causes the fuel injection valve 100 to inject fuel. Furthermore, the solenoid valve actuator 1 can also control the fuel injection valve 100 to not inject fuel during a cycle.

[0059] 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 time-repeated cycle. An energizing period represents the duration during which the solenoid coil 103 is energized within one cycle. 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.

[0060] 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., one cycle each of the intake stroke, compression stroke, combustion stroke, and exhaust stroke). 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. However, the number of fuel injections in one combustion cycle can be varied. For example, in the two fuel injections performed in one combustion cycle, the previous fuel injection is referred to as the initial injection. The subsequent fuel injection is referred to as the final injection.

[0061] The energization period correction unit 3e corrects the energization period, for example, based on the correction amount mapping M stored in the storage unit 3f. The energization period correction unit 3e calculates the correction amount, for example, based on the valve closing timing, by referring to the correction amount mapping M. The energization period correction unit 3e corrects the energization period by adding this correction amount to the energization period corresponding to the fuel injection quantity input from a higher-level control device, etc. Furthermore, in this embodiment, when the fuel injection valve 100 is controlled in a second injection mode, the energization period correction unit 3e calculates the correction amount for the second injection mode based on the correction amount of the energization period calculated from the correction amount mapping M using the coefficient mapping Mk stored in the storage unit 3f.

[0062] 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.

[0063] The storage unit 3f stores the aforementioned correction amount mapping M. The correction amount mapping M represents the relationship between the difference between the actual valve closing timing detected by the valve closing detection unit 3c and the controllable valve closing timing, and the correction amount during the energizing period. The controllable valve closing timing refers to the valve closing timing based on the energizing period corresponding to the fuel injection quantity input from the upper control device such as the solenoid valve drive device 1. The correction amount mapping M sets the correction amount to eliminate the error in the injection quantity caused by the difference between the actual valve closing timing and the controllable valve closing timing (valve closing timing difference). In this correction amount mapping M, the valve closing timing difference and the correction amount during the energizing period have a linear relationship.

[0064] However, in the second injection mode, in the correction mapping M in which the valve closing timing difference and the correction amount during the energizing period are linearly related, it is sometimes difficult to sufficiently reduce the error of the injection amount. Figure 8 This is a graph showing the relationship between the energizing period Ti and the valve closing time Toff of a certain fuel injection valve 100. As mentioned above, the second injection mode is an injection mode with a shorter injection period (energizing period) than the first injection mode, and a longer injection period (energizing period) than the third injection mode. Figure 8 In the process, the energizing period Ti between energizing period Ti1 and energizing period Ti2 becomes the second injection mode, the energizing period Ti is longer than the energizing period Ti2 becomes the first injection mode, and the energizing period Ti is shorter than the energizing period Ti1 becomes the third injection mode.

[0065] like Figure 8 As shown, during the energizing period Ti, which constitutes the first injection mode, the relationship between the energizing period Ti and the valve closing timing Toff is linear. On the other hand, during the energizing period Ti, which constitutes the second injection mode, the relationship between the energizing period Ti and the valve closing timing Toff is non-linear. During the energizing period Ti of this second injection mode, the valve section 120 is in motion, and the position of the valve section 120 is unstable. Therefore, in the correction amount mapping M, where the correction amount of the valve closing timing difference and the correction amount of the energizing period are linearly related, it is sometimes impossible to sufficiently suppress the error in the injection amount.

[0066] To further reduce fuel injection quantity errors in the second injection mode described above, a coefficient mapping Mk is stored in the storage unit 3f. The coefficient mapping Mk is a mapping that establishes a relationship between Ti during energization and coefficients used to reduce fuel injection quantity errors. These coefficients are multiplied by a correction amount obtained using the correction mapping M to obtain a value that further reduces fuel injection quantity errors.

[0067] Specifically, to determine the coefficients, the relationship between the energizing period Ti of the fuel injection valve 100 from energizing period Ti1 to energizing period Ti2 and the actual valve closing time Toff (actual valve closing time) is first obtained through experiments and simulations. This relationship represents the characteristics of the fuel injection valve 100 from energizing period Ti1 to energizing period Ti2 (hereinafter referred to as the reference characteristics). The coefficients are set as a curve based on this reference characteristic (…). Figure 8 The slope of the curve showing the relationship between the energizing period Ti and the valve closing time Toff is taken as the inverse. The coefficient is then calculated. Furthermore, the storage unit 3f stores not only the correction mapping M and the coefficient mapping Mk, but also the drive control program for the fuel injection valve 100 and various calculated values.

[0068] In the solenoid valve drive device 1 of this embodiment as described above, when the fuel injection valve 100 is controlled in the first injection mode (when the energizing period Ti is longer than the energizing period Ti2), the energizing period correction unit 3e corrects the energizing period by adding a correction amount shown by the correction amount mapping M to the energizing period corresponding to the fuel injection amount input from the upper control device, etc.

[0069] Furthermore, when the fuel injection valve 100 is controlled in the second injection mode (where the energizing period Ti is from energizing period Ti1 to energizing period Ti2), the energizing period correction unit 3e obtains a correction amount from the correction amount mapping M based on the energizing period corresponding to the fuel injection quantity input from the upper control device, etc. Then, the energizing period correction unit 3e calculates the correction amount for the second injection mode by multiplying the obtained correction amount by a coefficient corresponding to the energizing period corresponding to the fuel injection quantity input from the upper control device, etc. Additionally, the energizing period correction unit 3e corrects the energizing period by adding the correction amount for the second injection mode to the energizing period corresponding to the fuel injection quantity input from the upper control device, etc.

[0070] The fuel injection valve 100 controlled by the solenoid valve drive device 1 of this embodiment as described above includes a movable core 109, a valve section 120, and a valve body force spring 108. The movable core 109 is attracted in the valve-opening direction by energizing the solenoid coil 103. The valve section 120 moves in the valve-opening direction as the movable core 109 moves in the valve-opening direction. The valve body force spring 108 applies a force to the valve section 120 in the valve-closing direction.

[0071] The solenoid valve drive device 1 of this embodiment includes a valve closing detection unit 3c, an energizing period correction unit 3e, and an energizing control unit 3d. The valve closing detection unit 3c detects the valve closing timing of the valve section 120 based on the voltage value of the solenoid coil 103, i.e., the coil voltage value. The energizing period correction unit 3e corrects the energizing period to the solenoid coil 103 based on the valve closing timing. The energizing control unit 3d controls the energizing of the solenoid coil 103 based on the corrected energizing period.

[0072] Furthermore, the solenoid valve drive device 1 of this embodiment can control the fuel injection valve 100 based on a first injection mode and a second injection mode. The first injection mode is an injection mode in which energization of the solenoid coil 103 is maintained even after the movement of the valve portion 120, which is moved in the valve-opening direction and then abuts against the fixed core 101, stops. The second injection mode is an injection mode in which energization of the solenoid coil 103 is stopped during the movement of the valve portion 120, which is moved in the valve-opening direction and then abuts against the limiter.

[0073] In the first injection mode, the energizing period correction unit 3e corrects the energizing period by setting the valve closing timing and the correction amount of the energizing period to a linear relationship. In the second injection mode, the energizing period correction unit 3e corrects the energizing period based on the relationship between the valve closing timing during the movement period caused by the rebound of the valve section 120 and the actual energizing period.

[0074] In the fuel injection valve 100 controlled by the solenoid valve drive device 1 of this embodiment, the valve portion 120 in the closed state moves toward the limiter via the movable core 109 and moves together with the movable core 109 in the opening direction. When the movable core 109 collides with the limiter, the valve portion 120 moves away from the movable core 109 due to inertial force, and is then pushed back toward the closing direction by the valve body force spring 108. When the rebounding valve portion 120 collides with the movable core 109, the movable core 109 moves slightly toward the closing direction, and then moves toward the fixed core 101 again. As a result, the valve portion 120 reciprocates in the closing direction and the opening direction. That is, the valve portion 120 continues to move during the period from the moment the movable core 109 comes into contact with the limiter until the end of the reciprocating movement (the movement period caused by the rebound of the valve portion 120).

[0075] In contrast, the solenoid valve drive device 1 of this embodiment can control the fuel injection valve 100 in a first injection mode. In this first injection mode, even after the movement of the valve portion 120 stops due to the springback caused by the movable core 109 moving in the valve opening direction abutting against the fixed core 101, the energization of the solenoid coil 103 is maintained. In this first injection mode, the solenoid valve drive device 1 of this embodiment corrects the energization period by setting the valve closing timing and the correction amount of the energization period to a linear relationship.

[0076] Furthermore, the solenoid valve drive device 1 of this embodiment can control the fuel injection valve 100 in a second injection mode. In this second injection mode, energizing the solenoid coil 103 is stopped during the movement period caused by the rebound of the valve portion 120 after the movable core 109, which moves in the valve opening direction, abuts against the limiter. In this second injection mode, the solenoid valve drive device 1 of this embodiment corrects the energizing period based on the relationship between the valve closing timing during the movement period caused by the rebound of the valve portion 120 and the actual energizing period.

[0077] That is, the solenoid valve drive device 1 of this embodiment corrects the energizing period using different correction methods in the first injection mode and the second injection mode. Therefore, even in either the injection mode in which energizing the solenoid coil 103 stops after the valve section 120 reaches a stable open state, or the injection mode in which energizing the solenoid coil 103 stops during the movement caused by the rebound of the valve section 120, the solenoid valve drive device 1 of this embodiment can appropriately correct the energizing period according to the actual valve closing timing.

[0078] Furthermore, in the solenoid valve drive device 1 of this embodiment, in the second injection mode, the energization period correction unit 3e calculates the correction amount for the second injection mode by multiplying a coefficient determined based on the relationship between the valve closing time and the actual energization period by a correction amount obtained by treating the correction amount of the valve closing time and the energization period as a linear relationship. Additionally, the energization period correction unit 3e corrects the energization period based on the correction amount for the second injection mode.

[0079] The aforementioned coefficients vary depending on the fuel injection valve 100 that is being driven. In other words, the coefficients are determined based on the individual characteristics of the fuel injection valve 100 (the aforementioned baseline characteristics). Such coefficients can be predetermined through experiments and simulations. Therefore, by using the coefficients to calculate the correction amount for the second injection mode, and by correcting the energizing period based on this correction amount, the energizing period can be corrected in the second injection mode without performing complex calculations. Therefore, the solenoid valve drive device 1 of this embodiment can reduce the computational load on the energizing period correction unit 3e.

[0080] Furthermore, in the solenoid valve drive device 1 of this embodiment, the coefficient is the reciprocal of the slope of the curve based on the reference characteristic, which represents the relationship between the valve closing timing during the movement caused by the rebound of the valve section 120 and the actual energization period.

[0081] By using such a coefficient, the injection quantity can be controlled more accurately compared to the case where only the correction amount mapping M, which is linearly related to the correction amount during the energizing period, is used to correct the energizing period in the second injection mode.

[0082] Furthermore, in this embodiment, a storage unit 3f is provided, which stores a coefficient mapping Mk representing the relationship between the coefficients and the energizing period. This means that, compared to the case where the coefficient mapping Mk is stored in an external device, the solenoid valve drive device 1 of this embodiment can shorten the time required to read the coefficients into the energizing period correction unit 3e.

[0083] (Second Implementation)

[0084] Next, refer to Figure 9 The second 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.

[0085] Figure 9 This is a schematic structural diagram of the solenoid valve drive device 1A according to this embodiment. Figure 9As shown, in the solenoid valve drive device 1A, the storage unit 3f stores the second injection mode correction calculation mapping Md. The second injection mode correction calculation mapping Md is a correspondence diagram showing the relationship (reference characteristic) between the valve closing timing during the movement period caused by the rebound of the valve unit 120 (i.e., the second injection mode) and the actual energization period.

[0086] The second injection mode uses a correction amount to calculate the mapping Md, for example, by using the above... Figure 8 The range of energizing periods Ti1 to Ti2 for the reference characteristics shown replaces the vertical and horizontal axes, creating a reference energizing period for correction using the actual energizing period. That is, for the second injection mode, the horizontal axis of the mapping Md calculated using the correction amount is the valve closing timing, and the vertical axis is the reference energizing period for correction. The reference energizing period for correction differs from the actual energizing period only in name; the values ​​are the same.

[0087] In the second injection mode, the energization period correction unit 3e uses the second injection mode correction amount calculation mapping Md, which represents the reference characteristics of the fuel injection valve 100, to correct the energization period. Specifically, the energization period correction unit 3e calculates the difference between the reference energization period for correcting the valve closing timing (i.e., the actual energization period) detected by the valve closing timing detection unit 3c and the energization period when the valve closing timing is detected. The energization period correction unit 3e uses this difference as a correction amount and adds the calculated correction amount to the energization period corresponding to the fuel injection quantity input from the upper control device, etc., thereby correcting the energization period.

[0088] In the solenoid valve drive device 1A of this embodiment as described above, in the second injection mode, the energizing period correction unit 3e calculates the difference between the actual energizing period and the energizing period detected by the valve closing detection unit 3c based on reference characteristics. Furthermore, the energizing period correction unit 3e corrects the energizing period based on the difference.

[0089] According to this embodiment of the solenoid valve drive device 1A, it is possible to correct the energization period in the second injection mode without performing complex calculations. Therefore, the solenoid valve drive device 1 of this embodiment can reduce the computational load of the correction unit 3e during the energization period.

[0090] Furthermore, in the solenoid valve drive device 1A of this embodiment, the storage unit 3f stores the second injection mode correction amount calculation mapping Md. This solenoid valve drive device 1A of this embodiment, for example, compared to the case where the second injection mode correction amount calculation mapping Md is stored in an external device, can perform corrections during power-on in a shorter time.

[0091] 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.

[0092] In the above embodiments, the structure for correcting the energization period in the second injection mode using coefficient mapping Mk and correction amount calculation mapping Md for the second injection mode has been described. However, the present invention is not limited thereto. The present invention obtains the characteristics of the fuel injection valve 100 in the second injection mode in advance, and based on the characteristics obtained in advance in the second injection mode, reduces the error of the injection quantity in a method different from that in the first injection mode.

[0093] Furthermore, the above-described embodiments can also be described, for example, as in the following notes.

[0094] (Note 1)

[0095] An electromagnetic valve driving device controls a fuel injection valve, the fuel injection valve comprising: a movable core that is attracted in an opening direction by energizing a coil; a valve portion that moves in the opening direction as the movable core moves in that direction; and a force-applying portion that applies force to the valve portion in a closing direction.

[0096] The solenoid valve driving device includes:

[0097] The valve closing detection unit detects the valve closing timing based on the voltage value of the coil.

[0098] The energizing period correction unit corrects the energizing period of the coil based on the valve closing timing; and

[0099] The energizing control unit controls the energizing of the coil based on the revised energizing period.

[0100] The solenoid valve drive device can control the fuel injection valve based on a first injection mode and a second injection mode.

[0101] In the first injection mode, even after the movement of the valve portion stops due to the springback of the movable core moving in the valve opening direction and abutting against the limiter, the coil is still energized.

[0102] In the second injection mode, during the movement caused by the rebound of the valve portion after the movable core moves in the valve opening direction and abuts against the limiter, the energization of the coil is stopped.

[0103] The correction unit performs the following during the power-on period:

[0104] In the first injection mode, the correction amount for the valve closing timing and the energizing period is set to a linear relationship to correct the energizing period.

[0105] In the second injection mode, the energizing period is corrected based on the relationship between the valve closing timing and the actual energizing period during the movement caused by the valve rebound.

[0106] (Note 2)

[0107] According to the solenoid valve drive device described in Appendix 1, in the second injection mode, the correction unit performs the following during the energization period:

[0108] The correction amount for the second injection mode is obtained by multiplying a coefficient determined based on the relationship between the valve closing timing and the actual energizing period by the correction amount obtained by treating the valve closing timing and the energizing period as a linear relationship.

[0109] The energizing period is corrected using a correction amount based on the second injection mode.

[0110] (Note 3)

[0111] According to the solenoid valve drive device described in Appendix 2, the coefficient is the reciprocal of the slope of a curve representing the relationship between the valve closing timing and the actual energizing period during the movement caused by the rebound of the valve section.

[0112] (Note 4)

[0113] According to Appendix 3, the solenoid valve drive device includes a storage unit that stores a coefficient mapping representing the relationship between the coefficient and the energization period.

[0114] in,

[0115] (Note 5)

[0116] According to the solenoid valve drive device described in Appendix 1, in the second injection mode, the correction unit performs the following during the energization period:

[0117] Based on a reference characteristic representing the relationship between the valve closing timing and the actual energizing period during the movement caused by the rebound of the valve section, the difference between the actual energizing period and the energizing period of the valve closing timing detected by the valve closing detection unit is calculated.

[0118] The power-on period is corrected based on the difference.

[0119] (Note 6)

[0120] According to Appendix 5, the solenoid valve drive device includes a storage unit that stores a second injection mode calculation mapping that represents the relationship between the valve closing timing and the actual energizing period during the movement caused by the rebound of the valve.

[0121] Explanation of reference numerals in the attached figures

[0122] 1 Solenoid valve drive unit; 1A Solenoid valve drive unit; 2 Drive unit; 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; 100 Fuel injection valve; 101 Fixed core (limiter); 102 Valve seat; 103 Solenoid coil (coil); 104 Pin; 105 Valve body; 106 Retainer; 107 Lower limiter; 108 Valve body force spring (force application part); 109 Movable core; 110 Movable core force spring; 120 Valve part; M Correction amount mapping; Md Correction amount calculation mapping for second injection mode; Mk Coefficient mapping.

Claims

1. A solenoid valve driving device for controlling a fuel injection valve, the fuel injection valve comprising: a movable core that is attracted in an opening direction by energizing a coil; a valve portion that moves in the opening direction as the movable core moves in the opening direction; and a force-applying portion that applies force to the valve portion in a closing direction. The solenoid valve driving device includes: The valve closing detection unit detects the valve closing timing based on the voltage value of the coil. The energizing period correction unit corrects the energizing period of the coil based on the valve closing timing; and The energizing control unit controls the energizing of the coil based on the revised energizing period. The solenoid valve drive device can control the fuel injection valve based on a first injection mode and a second injection mode. In the first injection mode, even after the movement of the valve portion stops due to the springback of the movable core moving in the valve opening direction and abutting against the limiter, the coil is still energized. In the second injection mode, during the movement caused by the rebound of the valve portion after the movable core moves in the valve opening direction and abuts against the limiter, the energization of the coil is stopped. The correction unit performs the following during the power-on period: In the first injection mode, the correction amount for the valve closing timing and the energizing period is set to a linear relationship to correct the energizing period. In the second injection mode, the energizing period is corrected based on the relationship between the valve closing timing and the actual energizing period during the movement caused by the valve rebound.

2. The solenoid valve driving device according to claim 1, wherein, In the second injection mode, the correction unit performs the following during the energization period: The correction amount for the second injection mode is obtained by multiplying a coefficient determined based on the relationship between the valve closing timing and the actual energizing period by the correction amount obtained by treating the valve closing timing and the energizing period as a linear relationship. The energizing period is corrected using a correction amount based on the second injection mode.

3. The solenoid valve driving device according to claim 2, wherein, The coefficient is the reciprocal of the slope of a curve representing the relationship between the valve closing timing during the movement caused by the rebound of the valve section and the actual energization period.

4. The solenoid valve driving device according to claim 3, wherein, The solenoid valve drive device includes a storage unit that stores a coefficient mapping representing the relationship between the coefficient and the energization period.

5. The solenoid valve driving device according to claim 1, wherein, In the second injection mode, the correction unit performs the following during the energization period: Based on a reference characteristic representing the relationship between the valve closing timing and the actual energizing period during the movement caused by the rebound of the valve section, the difference between the actual energizing period and the energizing period of the valve closing timing detected by the valve closing detection unit is calculated. The power-on period is corrected based on the difference.

6. The solenoid valve driving device according to claim 5, wherein, The solenoid valve drive device includes a storage unit that stores a second injection mode correction amount mapping that represents the relationship between the valve closing timing and the actual energizing period during the movement caused by the rebound of the valve.

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