Fuel injection control device

Abstract

Fuel injection control device (100) for controlling a fuel injection valve (200) of an internal combustion engine, wherein the fuel injection control device (100) comprises the following: a valve opening start time calculation unit (1123) that estimates a valve opening start time at which the fuel injector (200) begins to open; and a reference data storage unit that stores reference data describing a characteristic of a reference fuel injector used as a reference when the valve opening start time calculation unit (1123) estimates the valve opening start time, wherein the valve opening start time calculation unit (1123) estimates the valve opening start time by referring to the reference data using a characteristic parameter representing the characteristic of the fuel injector (200), wherein the fuel injection control device (100) further comprises a control circuit (120) which opens the fuel injection valve (200) by supplying it with a control current, and the control circuit (120) reduces the control current when a fuel injection quantity through the fuel injection valve (200) reaches a target value, wherein the fuel injection control device (100) further comprises an actual valve opening time calculation unit (1125) which receives an actual opening time for which the fuel injection valve (200) is opened. The actual valve opening duration calculation unit (1125) uses the valve opening start time estimated by the valve opening start time calculation unit (1123) according to a first required value for an injection quantity of fuel injected by the fuel injector (200) and / or a second required value for a pulse width of a control signal for controlling a switching element (141, 142) that supplies a control current to the fuel injector (200), to switch whether the actual valve opening duration should be maintained. the actual valve opening duration calculation unit (1125) uses a predefined time as the valve opening start time of the fuel injector (200) instead of the valve opening start time estimated by the valve opening start time calculation unit (1123) if the first required value or the second required value is greater than or equal to a predefined threshold, wherein The specified threshold is a value that corresponds to the boundary between the full-lift area and the half-lift area.

Description

Technical field

[0001] The present invention relates to a control device for a fuel injection valve that injects and supplies fuel to an internal combustion engine. State of the art

[0002] Due to current regulations regarding vehicle fuel consumption and emissions, it is necessary to simultaneously achieve low fuel consumption and high power output from internal combustion engines, as well as suitability for a wide operating range. One means of achieving this is to extend the dynamic range of a fuel injector. To extend the dynamic range of the fuel injector, it is necessary to improve the dynamic flow characteristics while maintaining the conventional static flow characteristics. One known method for improving these dynamic flow characteristics is to reduce the minimum injection quantity through half-stroke control.

[0003] The half-stroke control system precisely controls a fuel injector in a state (hereinafter referred to as a half-stroke range) before a valve body within the fuel injector reaches a fully open position (hereinafter referred to as a full stroke). It is known that the injection quantity fluctuates significantly within the half-stroke range due to individual injector variations. Therefore, various techniques have been proposed to detect these individual variations in each fuel injector.

[0004] The following PTL 1 discloses a technique for indirectly detecting an individual difference in a valve opening operation of a fuel injector (more precisely, when a valve body is in a valve opening state) based on electrical characteristics. Furthermore, a technique for detecting a closing operation of a fuel injector from electrical characteristics is known.PTL 2 discloses a device comprising fuel injectors, each provided for each cylinder, an open / closed valve detection device for detecting one or both valve states of the fuel injectors based on the drive currents or drive voltages of the fuel injectors, and a detection execution determination device for determining a detection execution time period, including the detection start time and the detection end time of the open valve state or the closed valve state.

[0005] PTL 3 discloses a drive device for a fuel injection device for use in an internal combustion engine, wherein the fuel injection device is provided with a valve body that can open and close a fuel channel, a needle that activates an opening and closing valve by force transmission between itself and the valve body, and an electromagnet comprising a coil and a solid core that serve as a drive means for the needle, and a cylindrical nozzle holder that is arranged on the outer circumferential side of the needle, and the drive device controls a drive current flowing to the coil such that it decreases from the maximum drive current to a first drive current that is lower than the maximum drive current before the valve body reaches the maximum height position, so that the valve body reaches a height position that is lower than the maximum height position. List of oppositions patent literature PTL 1: JP 2014 - 152 697 A PTL 2: US 2018 / 0010545 A1 PTL 3: US 2018 / 0017005 A1 Summary of the invention: Technical problem

[0006] In the half-stroke region, the fuel injection quantity exhibits a strong correlation with the actual valve opening time. Therefore, by knowing the difference between the valve opening start time and the valve closing end time (i.e., the actual valve opening time), it is possible to determine the injection quantity variation for each injector. Since the fuel injector uses a pre-stroke mechanism to maintain a constant valve opening force in a region of the half-stroke region where the injection quantity is relatively large, the valve opening start time is also constant. Thus, the injection quantity variation can be detected by measuring the valve closing end time. Conversely, in the region of extremely small injection, the valve opening force is not constant, and the valve opening start time tends to be delayed, while the pulse width is shortened.Therefore, it is necessary to detect the initial valve opening time in order to control the injection quantity variation in the extremely small injection range. However, in this range, it is difficult to detect the initial valve opening time based on electrical characteristics because the excitation magnitude is small and the excitation time is extremely short.

[0007] The present invention was made in view of the problems described above, and one object of the present invention is to provide a technique for identifying a fluctuation in an injection quantity by estimating a valve opening start time in a region of extremely small injection of a half-stroke region. Solution to the problem

[0008] The problem is solved by the features of the independent patent claims. Advantageous embodiments of the invention are described in the dependent claims. Advantageous effects of the invention

[0009] According to the present invention, a fuel injection control device can detect the initial valve opening time of a fuel injector even in an extremely small injection range. Thus, by extending the control range in which the extremely small injection is performed, it is possible to reduce the fluctuation in the fuel injection quantity and to prevent unintended torque fluctuations or a deterioration in fuel consumption and exhaust emissions. Brief description of the drawings Fig. Figure 1 is a schematic diagram illustrating a configuration of a conventional fuel injection control device 100 and a fuel injection valve 200. Fig. Figure 2 is a graphical representation that illustrates a difference between an injection quantity characteristic in a full-stroke region and an injection quantity characteristic in a half-stroke region. Fig. Figure 3 is a graphical representation that illustrates a relationship between an injection pulse width, a control current signal shape and a valve behavior in a full stroke region. Fig. Figure 4 is a graphical representation that illustrates a relationship between an injection pulse width, a control current signal shape and a valve behavior in a half-stroke region. Fig. Figure 5 is a diagram that explains how a fluctuation in the injection quantity is suppressed by a valve opening time duration. Fig. Figure 6 is a schematic representation that explains the components of a fuel injector 200. Fig. Figure 7 is a diagram illustrating a relationship between a valve opening start time and a mechanical characteristic or an electrical characteristic that correlates with the valve opening start time. Fig. Figure 8 is a graphical representation that illustrates a change in valve behavior when an injection quantity is controlled based on an actual valve opening time. Fig. Figure 9 is a configuration principle circuit diagram of a fuel injection control device 100 according to a first embodiment. Fig. Figure 10 is a configuration principle circuit diagram of a pulse signal calculation unit 112 according to the first embodiment. Fig. Figure 11 is a schematic diagram that explains details of a reference valve opening start time calculation unit 1121. Fig. Figure 12 is a schematic diagram that explains details of a unit 1122 for calculating individual differences. Fig. Figure 13 is a schematic diagram that explains details of a target valve opening start time calculation unit 1123. Fig. Figure 14 is a diagram that explains the calculation performed by the target valve opening start time calculation unit 1123. Fig. Figure 15 is a schematic representation that explains details of an actual valve opening time calculation unit 1125. Fig. 16 is a flowchart that explains an operating procedure of the actual valve opening time calculation unit 1125. Fig. Figure 17 is a schematic diagram that explains details of a pulse width calculation unit 1126. Fig. 18 is a flowchart that explains an operating procedure of the pulse width calculation unit 1126. Description of embodiments

[0010] Fig. Figure 1 is a schematic diagram illustrating a configuration of a conventional fuel injection control device 100 and a fuel injection valve 200. The fuel injection control device 100 includes a microcomputer 110, an integrated control circuit (control IC) 120, a high-voltage generation unit 130, a high-voltage switch 141, a low-voltage switch 142, and a valve closing time detection unit 150. Furthermore, the microcomputer 110 includes a power machine condition detection unit 111, a pulse signal calculation unit 112, and a waveform command unit 113.

[0011] The engine condition detection unit 111 acquires various pieces of information, such as engine speed, intake air volume, coolant temperature, fuel pressure, and engine fault condition. Based on the various pieces of information acquired by the engine condition detection unit 111, the pulse signal calculation unit 112 calculates an injection pulse (an injection pulse width) that defines the fuel injection duration of the fuel injector 200.

[0012] The signal shape command unit 113 calculates a command value of a control current to open the fuel injection valve 200 or to maintain the valve opening state and outputs the command value to the control IC 120.

[0013] The high-voltage generating unit 130 uses a battery voltage 301 supplied via a fuse 302 and a relay 303 to generate a high-voltage supply voltage (hereinafter referred to as a high voltage) required when the electromagnetic solenoid fuel injector 200 is opened. Furthermore, based on a command from the control IC 120, the high-voltage generating unit 130 increases the battery voltage 301 to achieve a desired setpoint high voltage.

[0014] Thus, as a power source for the fuel injection valve, 200 power supplies from two systems can be supplied, i.e., the high voltage to ensure a valve opening force of a valve body and the battery voltage 301 to maintain the valve opening so that the valve body is not closed after the valve has been opened.

[0015] The two switches 141 and 142 are located on the inlet and outlet sides of the fuel injector 200, respectively. When these switches are open, control current is supplied to the fuel injector 200. The control IC 120 controls the high voltage or battery voltage 301 applied to the fuel injector 200 by switching the switches based on an injection pulse (the injection pulse width) calculated by the pulse signal calculation unit 112 and the control current profile calculated by the signal shape command unit 113. This controls the control current supplied to the fuel injector 200.

[0016] When the valve closing time detection unit 150 controls the fuel injector 200 in the half-stroke range, the valve closing time detection unit 150 detects the valve closing time from the characteristic change in the control voltage applied to the injector as a means of detecting the individual difference in injector behavior for each injector. The detection result is sent to the pulse signal processing unit 112.

[0017] Fig. Figure 2 is a graphical representation illustrating the difference between the injection quantity characteristics in the full-stroke region and the injection quantity characteristics in the half-stroke region. Section 203 is a region in which the injector is fully open and the fuel injection quantity is proportional to the pulse width; this section is referred to as the full-stroke region. Sections 201 and 202 are regions in which the injector is not fully open.

[0018] In section 202, the valve body oscillates at the end of the valve opening in the injector due to excessive valve opening force, and the injection quantity and pulse width are not simply proportional to each other. Therefore, the region in which the pulse width and injection quantity are proportional to each other can be extended, for example, by setting the valve opening force with a different control current signal waveform than that of section 203 and reducing the oscillation at the end of the valve opening.

[0019] Section 201 is an area where valve behavior and injection quantity exhibit a strong correlation. Since the mechanical or electrical characteristics of the injector strongly influence valve behavior in this area, pulse width and injection quantity are not simply proportional to each other, and the variation in injection quantity is simply proportional to the variation in each injector.

[0020] Thus, in the conventional range, the valve opening force is adjusted by switching the control current, and the pulse width for each injector is controlled based on the detection event of the valve behavior, thereby reducing the individual difference in the injection quantity. Attempts have been made in the conventional range to extend the range in which the pulse width and the injection quantity are proportional to each other to section 201. However, even in the conventional range, particularly in the extremely small injection quantity range of section 201, it is difficult to control the variation in the injection quantity for each injector. The present invention follows the conventional approach and is further intended to precisely control the variation in the injection quantity for each injector even in this extremely small injection quantity range.

[0021] Fig. Figure 3 is a graphical representation illustrating the relationship between the injection pulse width, the control current waveform, and the valve behavior in the full-stroke region. The injection pulse rises from T301, and the control current begins to excite the fuel injector 200 according to a predefined current waveform profile. After the start of excitation, the control current reaches a peak value due to the high voltage required to open the valve. The control voltage then switches to the battery voltage and maintains a control current b or c for a predetermined time. When it reaches T305, the injection pulse falls, and the control current stops excitation.

[0022] At T302, the injector begins to open, and at T303, the valve body reaches the end of its opening range, becoming fully open. During the period from T303 to T304, the valve body oscillates and behaves unstably due to excessive opening force. After the injection pulse is switched off at T305 and the excitation ceases, the opening force is lost, and the valve body moves into the closing position, with the valve closing at T306. In the full-stroke region, the valve body is fully open, so the relationship between the pulse width and the injection quantity is simply proportional.

[0023] Fig. Figure 4 is a graphical representation illustrating the relationship between the injection pulse width, the control current signal shape, and the valve behavior in the half-stroke region. At T401, the injection pulse width increases, and at T403, it decreases. A control current 412 and the valve behavior during this time interval are described.

[0024] The control current initiates the excitation according to a predefined current waveform profile. A high-voltage current is excited in a coil of the fuel injector 200, and when the excitation time (the time from T401 to T403) has elapsed or when the control current reaches 412a, the excitation is switched off.

[0025] After the excitation is switched off, the current quickly drops to 0 A. During excitation, a magnetic force is generated by the coil and received by a moving device and a valve body provided in the fuel injector 200, the difference between the magnetic force applied to the moving device and the valve body and the force in the valve closing direction as the valve opening force.

[0026] When the actuator of P401, at which point the valve opening force becomes positive, begins to move in the valve opening direction, it travels a pre-stroke 451, which is a length at which the actuator can operate, and then comes into contact with the valve body at T411. At T411, the valve body begins to move due to the impact force resulting from contact with the actuator. Thus, T411 is considered the initial point in time for valve opening.

[0027] Since the excitation is completed at T411, it is not influenced by the magnetic force, but rather by the spring load and the fuel pressure in the valve closing direction. Because the spring load and the fuel pressure in the valve closing direction can be considered constant over a short time interval, the valve body performs a parabolic motion of constant acceleration. A relationship between time and the position of the valve body in the fuel injector 200 is represented by a parabola 422. At T422, the valve body completes the valve closing and stops the injection.

[0028] The motion device continues to operate until a motion device reference position is reached and moves to P403.

[0029] Since the fuel injection quantity is the amount of fuel injected while the valve body is in a parabolic motion, a strong correlation exists between the injection quantity and the valve behavior. Because the magnitude of the valve behavior correlates with an area 431 enclosed by the parabola 422, it can be said that the injection quantity also exhibits a strong correlation with the area 431. Thus, the injection quantity can be known if the area 431 can be known, although it is not practical to measure the valve behavior during injector operation. Focusing on the fact that the valve behavior is a parabolic motion of constant acceleration, it can be mathematically seen that the area 431 correlates with the time from the valve opening start time T411 to the valve opening end time T422, i.e., with the valve opening duration 441.Thus, the injection quantity can be maintained if the valve opening time duration of 441 is detected.

[0030] In the region where the injection quantity is controlled by the pulse width (i.e., in the region controlled by the longer injection pulse width than that from T401 to T403), the valve behavior becomes a parabola 423. Since the valve opening force is sufficient in this region, and since the impact force when the moving device comes into contact with the valve body is constant, the valve opening start time T411 is also at the same point. Thus, in the conventional region, the valve opening time is obtained by detecting the valve closing time, and the injection quantity control is performed based on the valve opening time.

[0031] On the other hand, what the present invention controls is an area controlled with a shorter pulse width than that of T401 to T403. In this area, the control current signal shape 411 and the maximum current 411a are smaller than those of 412a. Thus, the magnetic force is reduced and the valve opening force is weakened, which affects the response sensitivity of the motion device. That is, the time at which the motion device comes into contact with the valve body is delayed by a duration 443. Since the assumption that the valve opening start time is constant, as in the conventional area, is not fixed, it is necessary to know a valve opening start time T412 in order to detect a valve opening duration 442.Although a technique for detecting the valve opening completion time from the change in current value is known, it is difficult to apply the technique because the valve opening begins after the excitation in the area to which the present invention is directed has been completed.

[0032] Fig. Figure 5 is a diagram illustrating how the variation in the injection quantity is suppressed over the valve opening time. The upper drawing from Fig. Figure 5 shows a relationship between the injection quantity and the injection pulse width. The lower drawing from Fig. Figure 5 shows a relationship between the injection quantity and the valve opening time.

[0033] The upper drawing from Fig. Figure 5 shows a relationship in a particular injector 501 and a relationship in another injector 502. One range of the injection quantity is a range of the extremely small quantity to which the present invention is directed and corresponds to the area of ​​T202 in section 201 of the above. Fig. 2. Since there is a variation in the individual difference when T503 is controlled with the same injection pulse width, the injection quantities 511 and 512 are not matched to each other. The following describes a case in which the injection quantity is set to 512.

[0034] The pulse width of injector 501 must be corrected to T501. Thus, according to the conventional domain, the valve closing time of each injector can be detected, and the pulse width of injector 501 can be corrected, for example, to T502. This correction in the conventional domain assumes that the valve opening start time is constant. As shown above, Fig. As described in section 4, it is necessary in practice to further shorten the pulse width, since the initial valve opening time is not constant in the region of extremely small injection. Therefore, the injection quantity is uneven in the conventional range alone.

[0035] In the lower drawing from Fig. Figure 5 shows a line 521, representing a relationship between an injection quantity and the result of measuring the valve behavior for each injector through experimentation and detection of the actual valve opening time. Although not perfectly fitted in practice, it confirms that a measurement result for each of the multiple injectors lies on line 521. This means that it is known that the variation in the injection quantity, even at extremely low injection quantities, can be precisely controlled by accurately detecting the valve opening time.

[0036] Fig. Figure 6 is a schematic representation illustrating the components of the fuel injector 200. The fuel injector 200 comprises a valve closing spring 601, a coil 602, a actuator 603, an actuator position definition spring 604, a valve body 605, and a valve seat 606. The valve body 605 operates in a section 607. In a section where the actuator 603 slides, a space 608 is provided between the actuator 603 and the coil or an external space. The actuator 603 operates in a pre-stroke 609.

[0037] As above based on Fig. As described in section 4, the valve opening start time is the time at which the actuator 603 comes into contact with the valve body 605 after the injection pulse has occurred. Thus, characteristics relating to the movement of the actuator 603 influence the valve opening start time. These characteristics can be classified into mechanical and electrical characteristics.

[0038] The mechanical characteristics relate to the difficulty of movement of the motion device 603. For example, there is the mass of the motion device 603, the spring load due to the motion device position definition spring 604, the design value of the clearance 608, and the pre-stroke 609 in relation to the operating time of the motion device 603. Various other factors can be considered, but the factors mentioned above have a particularly large influence.

[0039] The electrical characteristics include a control voltage (a voltage RMS value or setpoint) that influences the magnitude of the control current, which generates the valve opening force, a coil resistance that makes it difficult to excite the control current, a coil inductance, and the like. Various other factors can be considered, but the factors mentioned above have a particularly large influence.

[0040] Fig. Figure 7 is a diagram illustrating a relationship between the valve opening start time and the mechanical or electrical characteristic that correlates with the valve opening start time. Among the characteristics shown are those in Fig. The 6 characteristic values ​​shown represent three typical parameters as an example.

[0041] The upper drawing from Fig. Figure 7 shows a relationship 701 between the initial valve opening time and the control voltage of the fuel injector 200. The control voltage influences how the control current increases. That is, by influencing how the valve opening force increases, there is an effect on the acceleration of the motion of the moving device.

[0042] Since the movement of the motion device is accelerated proportionally to the increase in the control voltage, the initial valve opening time is thus shortened.

[0043] The middle drawing from Fig. Figure 7 shows a relationship 702 between the valve opening start time and the pre-stroke amount. Since the pre-stroke amount corresponds to the movement amount of the actuator, it is related to the movement time of the actuator. Because the movement time of the actuator increases proportionally to the increase in pre-stroke, the valve opening start time also increases.

[0044] The lower drawing from Fig. Figure 7 shows a relationship 703 between the valve opening start time and the moving device mass. Since the moving device mass affects the difficulty of the moving device's movement, it is related to the moving device's movement time. Thus, the valve opening start time becomes longer because the moving device's movement time increases proportionally to the increase in moving device mass.

[0045] Assuming that the relationship between each in Fig. Since the parameters shown in Figure 7 and the valve opening start time for each individual fuel injector 200 can be considered the same, the valve opening start time of the fuel injector 200 can be obtained by determining the parameters shown in Figure 7. Fig. The relationship shown in Figure 7 for the reference fuel injector is recorded in advance, and each parameter in the fuel injector 200 (i.e., each value on the horizontal axis) is determined. Fig. 7) is applied to any corresponding relationship. According to this principle, the present invention estimates the valve opening start time in the region with the extremely small injection.

[0046] For example, in the drawing above, Fig. 7. The deviation of the valve opening start time due to the fluctuation of the valve voltage 713, when the characteristic value of the reference injector is 711 and the characteristic value of the fuel injector is 712. Similarly, the magnitude of the valve opening start time can be calculated for other characteristic values. The deviation of the valve opening start time of the target fuel injector can be expressed as the total value of 713, 714, and 715 in Fig. 7 will be calculated.

[0047] Fig. Figure 8 is a graphical representation illustrating a change in valve behavior when the injection quantity is controlled based on an actual valve opening time. The upper drawing from Fig. Figure 8 shows a target injector behavior 831 and an actual injector behavior 832a when an injection pulse begins and is controlled in a section from T801 to T802. Regarding the valve opening start time, the target injector behavior is T811, while the actual injector behavior is T812. The valve opening start time T812 is determined by the above based on... Fig. The seven described methods are calculated, and the valve closing time T822 is detected by the conventional area. The actual valve opening time 841 is calculated from the valve closing time T822 and the valve opening start time T812. The target valve opening time 842, representing the desired valve behavior, is calculated from a required injection quantity and similar parameters.

[0048] As shown in the drawing above Fig. As shown in Figure 8, the valve opening time can be increased by increasing the valve opening force if the actual valve opening time 841 is less than the target valve opening time 842. Thus, a relationship between the valve opening time and the pulse width is established in advance, and the pulse width is corrected based on this relationship. In the case of Fig. 8 The pulse width is extended from T802 to T803, so that the valve opening time is aligned to 842 and a valve behavior 832b of the target injector is aligned to the target injector behavior 831 (lower drawing from Fig. 8) is adjusted. Thus, the variation in the injection quantity for each injector can be aligned with the corresponding quantity of the reference injector.

[0049] Fig. 9 is a configuration principle circuit diagram of a fuel injection control device 100 according to a first embodiment of the present invention. In addition to the above based on Fig. In the configuration described in Figure 1, the microcomputer 110 includes a reference data storage unit 114 and a unit 115 for recording individual data, and the fuel injector 200 stores individual data 210. Since the other configurations are the same as those in Figure 1, the following applies: Fig. The differences in relation to these functional parts are mainly described below.

[0050] The reference data storage unit 114 stores reference data. The reference data describes the relationship between the initial valve opening time of the reference fuel injector and the pulse width or injection quantity, and also describes the relationship between each in Fig. The 7 parameters shown and the valve opening start time for the reference fuel injector. The unit 115 for acquiring individual data reads the individual data 210 contained in the fuel injector 200. The individual data 210 describe, for each characteristic parameter, the characteristic value of the fuel injector 200 (which corresponds to the characteristic value 712 in Fig. 7 corresponds). The time for reading the individual data 210 can be considered, for example, the time when the fuel injector 200 is sent.

[0051] Fig. Figure 10 is a configuration principle circuit diagram of the pulse signal calculation unit 112 according to the first embodiment. The following sections describe, based on... Fig. 10. The differences between pulse width calculation in the conventional field and pulse width calculation in the first embodiment are described.

[0052] In the conventional domain, the fuel injection quantity is controlled within a range where the valve opening start time can be considered constant. Thus, an actual valve opening duration calculation unit 1125 calculates an actual valve opening duration from the difference between a predefined valve opening start time and a valve closing time detected by the valve closing time detection unit 150. The pulse width calculation unit 1126 calculates a pulse width correction amount by comparing a calculation result of a target valve opening duration calculation unit 1124 with the actual valve opening duration. Furthermore, an injection pulse width is corrected by the pulse width correction amount based on a machine condition detected by the engine condition detection unit 111, and the corrected injection pulse width is output as the injection pulse width.

[0053] On the other hand, in the first embodiment, the valve opening start time of the reference fuel injector is obtained according to the description of the reference data, and the individual difference between the valve opening start time of the reference fuel injector and the valve opening start time of the fuel injector 200 is obtained according to the description of the individual data 210. A target valve opening start time calculation unit 1123 obtains the valve opening start time of the fuel injector 200 based on this. Details of the respective functional units are described using the following: Fig. 11 and the following drawings.

[0054] Fig. Figure 11 is a schematic diagram illustrating the details of a reference valve opening start time calculation unit 1121. The reference valve opening start time calculation unit 1121 acquires reference data from the reference data storage unit 114 and also acquires a required injection pulse width or injection quantity from the engine condition detection unit 111. The reference valve opening start time calculation unit 1121 determines the valve opening start time of the reference fuel injection valve by referencing the reference data and using the required injection quantity or injection pulse width.

[0055] Fig. Figure 12 is a schematic diagram that explains the details of a unit 1122 for calculating individual differences. A summation unit 11222 receives the characteristic value of the fuel injector 200 from the unit 115 for recording individual data. The summation unit 11222 receives for each in Fig. The 7 characteristic parameters shown represent the difference between the valve opening start time of fuel injector 200 and the valve opening start time of the reference fuel injector, and are multiplied and summed by predefined weights 11221 for each characteristic parameter. This corresponds to the weighted sum of 713 to 715 in Fig. 7. If other characteristic parameters than those in Fig. Since 7 of the depicted units are present, the weighted sum is performed on all of them in a similar manner. A gain calculation unit 11223 calculates the individual difference of the valve opening start time corresponding to the required injection quantity or pulse width by multiplying the summation result by a gain corresponding to the required injection quantity or pulse width.

[0056] Fig. Figure 13 is a schematic diagram that explains details of the target valve opening start time calculation unit 1123. The target valve opening start time calculation unit 1123 calculates the valve opening start time of the fuel injector 200 by summing the calculation result obtained by the reference valve opening start time calculation unit 1121 and the calculation result obtained by the unit 1122 for calculating individual differences.

[0057] Fig. Figure 14 is a diagram illustrating the calculation performed by the target valve opening start time calculation unit 1123. A solid line 1401 represents the relationship between the valve opening start time of the reference fuel injector and the injection quantity or pulse width. A dotted line 1402 represents the relationship between the valve opening start time of fuel injector 200 and the injection quantity or pulse width. The target valve opening start time calculation unit 1123 calculates the valve opening start time T812 of fuel injector 200 by calculating the reference valve opening start time T811 and the individual difference 1403, and by adding the individual difference 1403 to T811. This makes it possible to estimate the initial valve opening time in the area of ​​extremely small injection, which was difficult to detect in the past.

[0058] Fig. Figure 15 is a schematic representation explaining details of the actual valve opening time calculation unit 1125. A valve opening start time selection unit 11252 selects a predetermined fixed valve opening start time 11251 or the calculation result obtained by the target valve opening start time calculation unit 1123 according to the required injection quantity or pulse width. A valve opening time calculation unit 11253 calculates an actual valve opening time by subtracting the selection result obtained by the valve opening start time selection unit 11252 from the detection result obtained by the valve closing time detection unit 150.

[0059] Fig. 16 is a flowchart that explains an operating procedure of the actual valve opening time calculation unit 1125.

[0060] The valve opening timing selection unit 11252 detects the required injection pulse width or the required injection quantity (S1601). The valve opening timing selection unit 11252 detects the valve opening timing of the fuel injector 200 from the target valve opening timing calculation unit 1123 (S1602). The valve opening timing selection unit 11252 determines whether the required injection quantity or required pulse width detected in S1601 is less than a predefined value (S1603). If the required value is less, the value obtained from the target valve opening timing calculation unit 1123 is used (S1604); otherwise, the fixed valve opening timing 11251 is used (S1605).

[0061] The specified value in step S1603 can either be a required value corresponding to the boundary between the full-stroke and half-stroke regions, or a minimum required value that is less than or equal to the required value and at which the valve opening force is sufficiently high and the initial valve opening time is constant. As in Fig. As shown in Figure 16, by selecting whether to accept the calculation result obtained through the target valve opening start time calculation unit 1123 or the fixed valve opening start time 11251, it is not necessary to reconstruct the entire control processing using the conventional technique where the valve opening start time is the fixed value. This is convenient for implementation.

[0062] Fig. Figure 17 is a schematic diagram that explains details of the pulse width calculation unit 1126. The pulse width conversion unit 11261 converts the valve opening duration calculated by the target valve opening duration calculation unit 1124 or the valve opening duration calculated by the actual valve opening duration calculation unit 1125 into pulse widths, based on the relationship between the pre-prepared pulse width and the valve opening duration. A difference pulse width calculation unit 11262 calculates the difference between the pulse width based on the target valve opening duration and the pulse width based on the actual valve opening duration. A unit 11263 for calculating the normal pulse width calculates a normal pulse width based on the detection result obtained by the force machine condition detection unit 111.If the calculation result obtained by unit 11263 for calculating the normal pulse width is less than or equal to a predetermined value, a pulse width correction unit 11264 corrects the pulse width by adding the calculation result obtained by the differential pulse width calculation unit 11262. If the pulse width based on the actual valve opening time is longer than the pulse width based on the target valve opening time, a negative differential pulse width is applied. In the opposite case, a positive differential pulse width is applied.

[0063] Fig. Figure 18 is a flowchart that explains an operating procedure of the pulse width calculation unit 1126. The unit 11263 for calculating the normal pulse width receives the required injection quantity or the required injection pulse width and the fuel pressure (S1801) from the engine condition detection unit 111. Using the required injection quantity or the required injection pulse width and the fuel pressure, the unit 11263 for calculating the normal pulse width calculates the normal pulse width (S1802). The differential pulse width calculation unit 11262 calculates the differential pulse width (S1803). The pulse width correction unit 11264 determines whether the calculated result of the normal pulse width is less than a predefined value (S1804). If it is smaller than the specified value, the normal pulse width is corrected from the normal pulse width and the difference pulse width (S1805) and the corrected pulse width is assumed (S1806).If it is less than or equal to the specified value, the normal pulse width is assumed (S1807).

[0064] Similar to the specified value in step S1603, the specified value in step S1804 can either be a required value corresponding to the boundary between the full stroke region and the half stroke region, or a minimum pulse width that is less than or equal to the required value and at which the valve opening force is sufficiently large and the valve opening start time is constant. <Erste Ausführungsform: Zusammenfassung>

[0065] The fuel injection control device 100 according to the first embodiment is the fuel injection control device (100) that controls the fuel injector (200) of the internal combustion engine and includes the valve opening start time calculation unit (1123), which estimates the valve opening start time at which the fuel injector (200) begins to open, and the reference data storage unit (114), which stores the reference data describing the characteristics of the reference fuel injector used as the reference when the valve opening start time calculation unit (1123) estimates the valve opening start time. The valve opening start time calculation unit (1123) estimates the valve opening start time by referring to the reference data using the characteristic parameter that represents the characteristics of the fuel injector (200).Thus, the valve opening start time of the fuel injector 200 can be estimated from the characteristics of the reference fuel injector.

[0066] The reference data describe the relationship between the characteristic reference parameter, which represents the characteristic of the reference fuel injector, and the reference valve opening start time, at which the reference fuel injector begins to open. The valve opening start time calculation unit (1123) estimates the valve opening start time by detecting the reference valve opening start time, which corresponds to the characteristic parameter representing the characteristic of the fuel injector (200), from the reference data. Thus, the valve opening start time of the fuel injector 200 can be estimated in advance by understanding the relationship between the characteristic of the reference fuel injector and the reference valve opening start time.

[0067] Furthermore, the fuel injection control device (100) includes the reference valve opening start time calculation unit (1121), which obtains the reference valve opening start time using the reference data.

[0068] Furthermore, the fuel injection control device (100) includes the unit (1122) for calculating individual differences, which obtains the difference between the reference valve opening start time and the valve opening start time using the characteristics of the fuel injector (200). The valve opening start time calculation unit (1123) estimates the time at which the fuel injector (200) begins to open according to the difference obtained by the unit (1122) for calculating individual differences. Thus, the valve opening start time can be estimated from the difference from the reference valve opening start time, even if it is difficult to detect the valve opening start time itself of the fuel injector (200).

[0069] The reference data describe the relationship between the characteristic reference parameter and the reference valve opening start time for each of the several characteristic reference parameters. The valve opening start time calculation unit (1123) identifies the characteristic reference parameter corresponding to the characteristic parameter and extracts from the reference data the difference between the valve opening start time and the reference valve opening start time corresponding to the identified characteristic reference parameter. The valve opening start time calculation unit (1123) estimates the valve opening start time by multiplying the difference by the weight determined for each characteristic reference parameter and adding the result of the multiplication to the reference valve opening start time.Thus, the valve opening start time can be estimated taking into account the influence, even if the influence on the valve opening start time differs according to the characteristics of the fuel injector (200).

[0070] Furthermore, the fuel injection control device (100) includes the valve opening duration calculation unit (112), which defines the valve opening duration for opening the fuel injector (200). The valve opening duration calculation unit (112) defines the valve opening duration such that the fuel injector (200) is opened from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening duration of the fuel injector (200) is reached. Thus, the injection quantity by the fuel injector (200) can be adjusted to the target value according to the estimated valve opening start time.

[0071] Furthermore, the fuel injection control device (100) includes the switching elements (141, 142) that switch the control current supplied to the fuel injector (200) on and off. The fuel injection control device (100) also includes the pulse width calculation unit (1126), which calculates the pulse width of the signal for switching on the switching elements (141, 142). The pulse width calculation unit (1126) calculates the pulse width such that the fuel injector (200) is opened from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening duration of the fuel injector (200) is reached. Thus, the injection quantity by the fuel injector (200) can be adjusted to the target value according to the estimated valve opening start time using pulse width control.

[0072] Furthermore, the fuel injection control device (100) includes the valve closing time detection unit (150), which detects the valve closing time when the fuel injector (200) closes. The fuel injection control device (100) also includes the actual valve opening time calculation unit (1125), which calculates the actual valve opening time, for which the fuel injector (200) is actually open, according to the valve opening start time and the valve closing time. The valve opening time calculation unit (1125) adjusts the valve opening time such that the actual valve opening time is adapted to the target valve opening time. Thus, the valve opening time can be set according to the estimated valve opening start time and the actual valve closing time.This means that the injection quantity of the fuel injector 200 can be controlled by using the technology for detecting the valve closing time in the conventional area.

[0073] The reference data describe the mechanical characteristics of the reference fuel injector. The mechanical characteristics of the reference fuel injector are the stroke amount (609) to which the moving device (603) contained in the reference fuel injector moves from the time the moving device (603) begins to move until the time the reference fuel injector comes into contact with the valve body (605), and / or the mass of the moving device (603), and / or the space (608) provided between the moving device (603) and the reference fuel injector in the section in which the moving device (603) slides, and / or the spring force of the spring (604) that moves the moving device (603) in the direction of closing the reference fuel injector.Thus, the valve opening start time can be estimated according to the motion characteristics of the actuator (603). Since the motion characteristics of the actuator (603) may be known at the time of design or manufacture, it is useful to use them for the estimation.

[0074] The reference data describe the electrical characteristics of the reference fuel injector. These characteristics are the electrical resistance of the coil (602) that electromagnetically drives the valve body of the reference fuel injector, and / or the inductance of the coil (602), and / or the RMS value or the setpoint of the drive voltage supplied to the reference fuel injector. Thus, the initial valve opening time can be estimated based on the electrical characteristics of the fuel injector (200). Since the electrical characteristics of the fuel injector (200) are relatively easy to obtain, it is useful to use them for this estimation.

[0075] Furthermore, the fuel injection control device (100) includes the control circuit (120), which opens the fuel injector (200) by supplying it with the control current. The control circuit (120) reduces the control current when the fuel injection quantity through the fuel injector (200) reaches the setpoint. Thus, the injection quantity through the fuel injector (200) can be appropriately controlled based on the estimated initial valve opening time.

[0076] Furthermore, the fuel injection control device (100) includes the actual valve opening duration calculation unit (1125), which maintains the actual opening duration for which the fuel injector (200) is open. Using the valve opening start time estimated by the valve opening start time calculation unit (1123), the actual valve opening duration calculation unit (1125) switches, according to the first required value for the injection quantity of fuel injected by the fuel injector (200) and / or the second required value for the pulse width of the control signal, the switching elements (141, 142) that supply the control current to the fuel injector (200) to control whether the actual valve opening duration is to be maintained.If the first or second requested value is greater than or equal to the specified threshold, the actual valve opening duration calculation unit (1125) uses the predefined time as the fuel injector (200) valve opening start time instead of the valve opening start time estimated by the valve opening start time calculation unit (1123) (S1605). If the first or second requested value is less than the specified threshold, the actual valve opening duration calculation unit (1125) uses the valve opening start time estimated by the valve opening start time calculation unit (1123) as the fuel injector (200) valve opening start time (S1604). The specified threshold is set less than or equal to the value for full opening of the fuel injector (200).Thus, the fuel injector (200) can be controlled by following the conventional control procedure in the full-stroke region and using the result of the estimation of the valve opening start time according to the first embodiment in the half-stroke region.

[0077] Furthermore, the fuel injection control device (100) includes the pulse width calculation unit (1126), which receives the pulse width of the control signal for controlling the switching elements (141, 142) that supply the control current to the fuel injector (200). The pulse width calculation unit (1126) receives the normal value of the pulse width according to the first required value and / or the second required value and / or the fuel pressure of the fuel injector (200) (S1802). If the normal value is greater than or equal to a predetermined threshold value, the pulse width calculation unit (1126) uses the normal value as the pulse width of the control signal (S1807).If the normal value is less than the specified threshold, the pulse width calculation unit (1126) corrects the normal value using the difference between the actual valve opening duration and the target valve opening duration and uses the corrected value as the pulse width of the control signal (S1806). Thus, the fuel injector (200) can be controlled by following the conventional control procedure in the full-stroke range and using the result of the valve opening start time estimation according to the first embodiment in the half-stroke range. <Zweite Ausführungsform>

[0078] In the first embodiment, it has been described that the valve opening time is controlled by controlling the control pulse width to actuate switches 141 and 142. On the other hand, the pulse signal calculation unit 112 controls the pulse width to control the valve opening time, and the signal shape command unit 113 controls the peak value of the control current or the like (302a to 302c in Fig. 3 etc.). Thus, these can operate independently. Depending on the command value from the signal-shape command unit 113, the injection quantity can reach the target value at an earlier time than the pulse drop time calculated by the pulse signal calculation unit 112. In the second embodiment of the present invention, an operating procedure in such a case is described.

[0079] The fuel injection quantity correlates with the valve behavior. More precisely, the target injection quantity is achieved when a time integral S of the target injector behavior 831 and a time integral S' of the actual injector behavior 832a are in Fig. 8 are adapted to each other. Furthermore, a time integral of the valve behavior correlates with a time integral of the control current of the fuel injection valve 200. Thus, the signal shape control unit 113 can switch off the control current according to the following procedure when the fuel injection quantity reaches the target value.

[0080] A value obtained by converting the target valve opening duration into a current integral is set as a target valve opening current integral, and a value obtained by converting the actual valve opening duration into a current integral is set as an actual valve opening current integral. The signal shape control unit 113 calculates the difference between the target valve opening current integral and the actual valve opening current integral. Based on this difference, the signal shape control unit 113 calculates a target current integral for the fuel injector 200. The signal shape control unit 113 calculates the current integral by detecting the control current during injection, e.g., every 1 ms, and compares the current integral with the target current integral. When both are matched, the signal shape control unit 113 switches off the control current.A specific method for switching off the drive current includes, for example, (a) reducing the current signal shape (of the peak value of the drive value), (b) reducing the drive pulse, (c) directly inputting the excitation stop command into the drive IC 120.

[0081] If the above integral is obtained, the signal shape command unit 113 does not necessarily need to integrate the current signal shape strictly over time and can obtain an approximate integral value. For example, the integral value of the drive current can be obtained by approximate calculation using the peak value of the drive current and the time at which the drive current or drive pulse begins to fall. For example, the current signal shape from Fig. 4 can be considered a right-angled triangle and the time integral can be easily obtained.

[0082] In the first embodiment, it has been described that the control pulse is controlled to align the fuel injection quantity with the setpoint, whereas the control current signal waveform can be controlled either instead or in conjunction with it. More precisely, the signal waveform control unit 113 can receive the time integral of the control current and control the control current signal waveform in such a way that the time integral approaches the setpoint. <Zweite Ausführungsform: Zusammenfassung>

[0083] The fuel injection control device (100) further includes the signal shape control unit (113), which determines the current signal shape of the control current supplied to the fuel injector (200). The signal shape control unit (113) determines the current signal shape of the control current such that the fuel injector (200) is opened from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening duration of the fuel injector (200) is reached. Thus, the injection quantity of the fuel injector (200) can be controlled to the target value by controlling the control current signal shape, in addition to or instead of the control pulse width.

[0084] The signal shape control unit (113) increases or decreases the time integral of the control current to open the fuel injector (200) from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening duration of the fuel injector (200) is reached. Thus, the injection quantity of the fuel injector (200) can be controlled to the target value independently of the control pulse width.

[0085] The signal shape control unit (113) increases or decreases the time integral of the drive current by changing the peak current value of the drive current and / or the time at which the drive current begins to fall. Thus, the time integral of the drive current can be easily obtained. <Amendment to the present invention>

[0086] The present invention is not limited to the embodiments described above, and various modifications can be made to it. For example, the embodiments have been described in detail for ease of understanding of the present invention and are not intended to limit it to those that necessarily include all the configurations described above. Furthermore, a part of a configuration of a particular embodiment can be replaced by a configuration of another embodiment, and a configuration of another embodiment can be added to a configuration of a particular embodiment. Moreover, it is possible to add, remove, or replace a part of a configuration of any embodiment with another configuration.

[0087] In the embodiments described above, it has been described that the difference between the initial valve opening time of the reference fuel injector and the initial valve opening time of fuel injector 200 is obtained, but instead of the difference, ratios of the two times can be used. Similarly, in the second embodiment, these ratios can be used instead of the difference between the target valve opening current integral value and the actual valve opening current integral value.

[0088] All or some of the configurations, functions, processing units, processing means, and the like described above can be implemented by hardware, for example, by the design of integrated circuits or the like. Furthermore, each of the configurations, functions, and the like described above can be implemented by software, which causes a processor to interpret and execute a program that implements each function. Information from the programs, tables, files, and the like that implement each function can be stored in a storage device such as memory, a hard disk drive, a solid-state drive (SSD), or a recording medium such as an IC card or SD card. In addition, control lines or information lines indicate what is considered necessary for the description, and not all control lines or information lines are necessarily shown in products.In practice, it can be observed that almost all structures are interconnected. Reference symbol list 100 Fuel injection control device 110 microcomputers 111 Power Machine Condition Detection Unit 112 Pulse signal calculation unit 113 Signal shape command unit 120 control ICs 130 High-voltage generating unit 141 Hi-switch 142 Lo switches 150 Valve closing time detection unit 200 Fuel injector

Claims

[1] Fuel injection control device (100) for controlling a fuel injection valve (200) of an internal combustion engine, wherein the fuel injection control device (100) comprises: a valve opening start time calculation unit (1123) that estimates a valve opening start time at which the fuel injector (200) begins to open; and a reference data storage unit that stores reference data describing a characteristic of a reference fuel injector used as a reference when the valve opening start time calculation unit (1123) estimates the valve opening start time, wherein the valve opening start time calculation unit (1123) estimates the valve opening start time by referring to the reference data using a characteristic parameter representing the characteristic of the fuel injector (200), wherein the fuel injection control device (100) further comprises a control circuit (120) which opens the fuel injection valve (200) by supplying it with a control current, and the control circuit (120) reduces the control current when a fuel injection quantity through the fuel injection valve (200) reaches a target value, wherein the fuel injection control device (100) further comprises an actual valve opening time calculation unit (1125) which receives an actual opening time for which the fuel injection valve (200) is opened. The actual valve opening duration calculation unit (1125) uses the valve opening start time estimated by the valve opening start time calculation unit (1123) according to a first required value for an injection quantity of fuel injected by the fuel injector (200) and / or a second required value for a pulse width of a control signal for controlling a switching element (141, 142) that supplies a control current to the fuel injector (200), to switch whether the actual valve opening duration should be maintained. the actual valve opening duration calculation unit (1125) uses a predefined time as the valve opening start time of the fuel injector (200) instead of the valve opening start time estimated by the valve opening start time calculation unit (1123) if the first required value or the second required value is greater than or equal to a predefined threshold, wherein The specified threshold is a value that corresponds to the boundary between the full-lift area and the half-lift area. [2] Fuel injection control device (100) according to claim 1, wherein the reference data describe a relationship between a characteristic reference parameter representing the characteristic of the reference fuel injection valve and a reference valve opening start time at which the reference fuel injection valve begins to open, and the valve opening start time calculation unit (1123) estimates the valve opening start time from the reference data by detecting the reference valve opening start time corresponding to the characteristic parameter representing the characteristic of the fuel injection valve (200). [3] Fuel injection control device (100) according to claim 2, wherein the fuel injection control device (100) further comprises a reference valve opening start time calculation unit (1123) which obtains the reference valve opening start time using the reference data, and wherein the fuel injection control device (100) further comprises a unit for calculating individual differences which obtains a difference between the reference valve opening start time and the valve opening start time using the characteristics of the fuel injection valve (200), and the valve opening start time calculation unit (1123) estimates a time at which the fuel injection valve (200) begins to open according to the difference obtained by the unit for calculating individual differences. [4] Fuel injection control device (100) according to claim 2, wherein the reference data describe a relationship between the characteristic reference parameter and the reference valve opening start time for each of several characteristic reference parameters, the valve opening start time calculation unit (1123) identifies the characteristic reference parameter corresponding to the characteristic parameter and determines a difference between the valve opening start time and the reference valve opening start time corresponding to the identified characteristic reference parameter from the reference data, and the valve opening start time calculation unit (1123) estimates the valve opening start time by multiplying the difference by a weight determined for each characteristic reference parameter and by adding the multiplication result to the reference valve opening start time. [5] Fuel injection control device (100) according to claim 1, wherein the fuel injection control device (100) further comprises a valve opening duration calculation unit (11253) which defines a valve opening duration for opening the fuel injection valve (200), and the valve opening duration calculation unit (11253) defines the valve opening duration in such a way that the fuel injection valve (200) is opened from the valve opening start time estimated by the valve opening start time calculation unit (1123) until a target valve opening duration of the fuel injection valve (200) is reached. [6] Fuel injection control device (100) according to claim 5, wherein the fuel injection control device (100) further comprises switching elements (141, 142) that switch on / off a control current supplied to the fuel injection valve (200), the fuel injection control device (100) further comprises a pulse width calculation unit (1126) which calculates a pulse width of a signal for switching on the switching elements (141,142), and The pulse width calculation unit (1126) calculates the pulse width in such a way that the fuel injector (200) is opened from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening time duration of the fuel injector (200) is reached. [7] Fuel injection control device (100) according to claim 5, wherein the fuel injection control device (100) further comprises a signal shape command unit (113) which determines a current signal shape of a control current supplied to the fuel injection valve (200), and the signal shape command unit (113) determines the current signal shape of the control current in such a way that the fuel injection valve (200) is opened from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening time duration of the fuel injection valve (200) is reached. [8] Fuel injection control device (100) according to claim 7, wherein the signal shape command unit (113) increases or decreases a time integral of the control current for opening the fuel injection valve (200) from the valve opening start time estimated by the valve opening start time calculation unit (1123) until the target valve opening time duration of the fuel injection valve (200) is reached. [9] Fuel injection control device (100) according to claim 8, wherein the signal shape command unit (113) increases or decreases the time integral of the control current by changing a peak current value of the control current value and / or a time at which the control current begins to fall. [10] Fuel injection control device (100) according to claim 5, wherein the fuel injection control device (100) further comprises a valve closing time detection unit (150) which detects a valve closing time when the fuel injection valve (200) is closed, the fuel injection control device (100) further comprises an actual valve opening duration calculation unit (1125) which calculates an actual valve opening duration for which the fuel injection valve (200) is actually opened, according to the valve opening start time and the valve closing time, and The valve opening time calculation unit (11253) adjusts the valve opening time in such a way that the actual valve opening time is adapted to a target valve opening time. [11] Fuel injection control device (100) according to claim 1, wherein the reference data describe a mechanical characteristic of the reference fuel injection valve, and the mechanical characteristic of the reference fuel injector is a stroke amount to which a moving device (603) contained in the reference fuel injector moves from the time at which the moving device (603) begins to move until the time at which the reference fuel injector comes into contact with the valve body (605), and / or a mass of the moving device (603), and / or an intermediate space (608) provided between the moving device (603) and the reference fuel injector in a section in which the moving device (603) slides, and / or a spring load of a spring (604) that moves the moving device (603) in a direction of closing the reference fuel injector. [12] Fuel injection control device (100) according to claim 1, wherein the reference data describe an electrical characteristic of the reference fuel injection valve, and The electrical characteristic of the reference fuel injector is an electrical resistance of a coil (602) that electromagnetically drives a valve body (605) of the reference fuel injector, and / or an inductance of the coil (602) and / or an RMS value or a setpoint of a control voltage supplied to the reference fuel injector. [13] Fuel injection control device (100) according to claim 1, wherein The actual valve opening duration calculation unit (1125) uses the valve opening start time estimated by the valve opening start time calculation unit (1123) as the valve opening start time of the fuel injector (200) if the first required value or the second required value is less than the specified threshold, and The specified threshold is set to be less than or equal to a value for the full opening of the fuel injector (200). [14] Fuel injection control device (100) according to claim 13, wherein the fuel injection control device (100) further comprises a pulse width calculation unit (1126) which receives a pulse width of a control signal for controlling a switching element (141, 142) which supplies a control current to the fuel injection valve (200), the pulse width calculation unit (1126) receives a normal value of the pulse width according to the first required value and / or the second required value and / or the fuel pressure of the fuel injector (200), The pulse width calculation unit (1126) uses the normal value as the pulse width of the drive signal if the normal value is greater than or equal to a predefined threshold, and The pulse width calculation unit (1126) corrects the normal value using a difference between the actual valve opening time and a target valve opening time and uses the corrected value as the pulse width of the control signal if the normal value is less than the specified threshold.

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