JP6354697B2 - Injection control device - Google Patents

Description

  The present invention relates to an injection control device that controls the operation of a fuel injection valve driven by electromagnetic force.

  The internal combustion engine is provided with a fuel injection valve for injecting fuel and supplying it to the internal combustion engine. The fuel injection valve is configured as an electromagnetic valve in which an internal valve body is driven by an electromagnetic force generated by supplying a driving current, and its opening and closing is switched.

  The injection control device controls the opening / closing operation of the fuel injection valve so that the fuel injection amount from the fuel injection valve matches the target injection amount. Specifically, the opening time of the fuel injection valve is adjusted by adjusting the length of time (energization time) during which the drive current is supplied to the fuel injection valve, and thereby the injection amount is set to a predetermined amount. Match the target value.

  By the way, the relationship between the injection amount of the fuel injection valve and the energization time is not always the same, and there are variations due to individual differences for each fuel injection valve, deterioration of the fuel injection valve, and operating conditions such as ambient temperature. It is known. In particular, fuel injection is performed under operating conditions in which the target injection amount is small and the opening of the fuel injection valve does not reach the maximum (the valve body does not reach the position where the valve is most open). In this case, the variation in the injection amount tends to increase. For this reason, it is necessary to correct the energization time, the magnitude of the drive current, and the like in accordance with the state of the fuel injection valve so as to approach the target value of the actual injection amount.

  Therefore, the control device described in Patent Document 1 below estimates the behavior of the valve body and the movable core based on the change in the driving current that actually flows, and has reached the position where the valve body is the most open side. Timing (valve opening completion timing) and timing (valve closing completion timing) that has reached the position closest to the valve closing side after fuel injection are detected. The change in the state of the fuel injection valve is grasped as a change in length from the time when the drive current starts to be supplied until the valve opening completion timing (or valve closing completion timing), and the injection amount is adjusted based on the change. It is possible.

  Further, the fuel injection control device described in Patent Document 2 below estimates the valve closing completion timing based on the behavior of the flyback voltage generated immediately after the supply of the driving current is stopped. The injection amount can be adjusted by correcting the injection pulse based on the length of the period from when the driving current starts to be supplied until the valve closing completion timing.

International Publication No. 2013/191267 JP2015-96720A

  The timing at which the drive current starts to be supplied does not necessarily coincide with the valve opening start timing at which the fuel injection valve starts to open, and the relationship between the two may vary. In particular, the movable core driven by electromagnetic force and the valve body that moves by receiving force from the movable core are separated, and a gap is formed between the two when the valve is closed. In a fuel injection valve having a structure, variation in valve opening start timing tends to increase due to variation in gap or the like. For this reason, in order to appropriately adjust the injection amount and suppress the variation, it is desirable to accurately estimate not only the valve opening completion timing and the valve closing completion timing but also the valve opening start timing.

  However, since the moving speed is low when the valve body starts to move in the valve opening direction, fluctuations in the drive current due to the start of movement of the valve body and the movable core are hardly detected. Therefore, it is difficult to directly estimate (calculate) the valve opening start timing based on the change in the driving current.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an injection control device capable of suppressing variations in injection amount by accurately calculating the valve opening start timing of a fuel injection valve. It is to provide.

In order to solve the above problems, an injection control device according to the present invention is an injection control device that controls the operation of a fuel injection valve driven by electromagnetic force, and detects a drive current supplied to the fuel injection valve. A current detecting unit that performs the opening operation of the fuel injection valve, a speed calculation unit that calculates a valve opening speed of the fuel injection valve based on a change in driving current, and an opening degree of the fuel injection valve A first timing calculation unit that calculates a valve opening completion timing that is a maximum timing. In addition, a second timing calculation unit that calculates a valve opening start timing that is a timing at which the fuel injection valve starts to open based on the calculated valve opening speed and the valve opening completion timing is further provided. The speed calculation unit calculates the valve opening speed based on a length of a period from a predetermined timing to a timing when the driving current decreases from the maximum value and falls below the predetermined threshold.

  In such an injection control device, the valve opening speed of the fuel injection valve, that is, the moving speed of the valve body is calculated based on the change in the drive current when the fuel injection valve is performing the valve opening operation. Further, the valve opening completion timing, which is the timing at which the opening degree of the fuel injection valve becomes maximum, is calculated by the first timing calculation unit. Such valve opening completion timing can be calculated by a method similar to the conventional method, for example, based on a change in driving current.

  The distance that the valve element moves from the start of the valve opening to the completion of the valve opening is known. Therefore, the second timing calculation unit can calculate a valve opening start timing that is a timing at which the fuel injection valve starts to open based on the valve opening speed and the valve opening completion timing calculated as described above. .

  ADVANTAGE OF THE INVENTION According to this invention, the injection control apparatus which can suppress the dispersion | variation in injection quantity by calculating the valve opening start timing of a fuel injection valve correctly is provided.

It is a figure which shows the structure of the injection control apparatus which concerns on the implementation system etc. of this invention, and the internal combustion engine provided with the said injection control apparatus. It is a figure which shows typically the structure of the fuel injection valve shown by FIG. It is a figure for demonstrating operation | movement of a fuel injection valve. It is a graph which shows the change of the position of each component when the fuel injection valve is operating. It is a graph which shows changes, such as a current for drive supplied to a fuel injection valve. It is a graph which shows operation | movement of the fuel injection valve at the time of partial lift injection. It is a block diagram which shows the functional structure of the injection control apparatus shown by FIG. It is a graph for demonstrating the calculation method of valve opening speed. It is a figure for demonstrating the calculation method of valve opening completion timing. It is a figure for demonstrating the calculation method of valve opening start timing. It is a figure for demonstrating the calculation method of valve closing completion timing. It is a figure for demonstrating correction | amendment of the injection control amount. It is a flowchart which shows the flow of the process performed by the injection control apparatus. It is a figure for demonstrating the dispersion | variation in the valve opening timing of a fuel injection valve.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  An injection control apparatus 100 according to an embodiment of the present invention will be described with reference to FIG. The injection control device 100 is attached to a part of a vehicle GC including the internal combustion engine 10 and is a device for controlling the operation of the fuel injection valve 40 provided in the internal combustion engine 10.

  The configuration of the vehicle GC will be described first. The vehicle GC includes an internal combustion engine 10, an intake pipe 20, and an exhaust pipe 30.

  The internal combustion engine 10 is a four-cycle reciprocating engine having a plurality of cylinders, and generates driving force by burning liquid fuel in the cylinders. Since the configuration of each cylinder is substantially the same, only a single cylinder is illustrated as “internal combustion engine 10” in FIG.

  Various sensors such as a coolant temperature sensor 11, a knock sensor 12, and a crank angle sensor 13 are attached to each cylinder of the internal combustion engine 10. The coolant temperature sensor 11 is a temperature sensor for measuring the temperature of coolant circulating between a radiator (not shown) and the internal combustion engine 10. The knock sensor 12 is a sensor for detecting knocking (abnormal combustion) that occurs inside the cylinder of the internal combustion engine 10. The crank angle sensor 13 is a sensor for measuring the rotation angle of the crankshaft provided in the cylinder. Each measured value obtained by these sensors is input to the injection control device 100.

  The internal combustion engine 10 is provided with a fuel injection valve 40. The fuel injection valve 40 is also referred to as an injector, and is an electromagnetic valve for injecting fuel into the cylinder of the internal combustion engine 10. The fuel injection valve 40 is supplied with fuel pressurized by a fuel pump (not shown). When the fuel injection valve 40 is opened, the fuel injected from the tip is supplied into the cylinder while being mixed with air. The injection control device 100 adjusts the amount of fuel supplied to the internal combustion engine 10 by controlling the opening / closing operation of the fuel injection valve 40. The specific configuration and operation of the fuel injection valve 40 will be described later.

  The intake pipe 20 is a pipe for supplying air to the internal combustion engine 10. The intake pipe 20 is provided with an air cleaner 21, an air flow meter 22, a throttle valve 23, and a surge tank 25 in order from the upstream side (left side in FIG. 1). The internal combustion engine 10 is connected to the downstream end (right side in FIG. 1) of the intake pipe 20.

  The air cleaner 21 is a filter for removing foreign substances from the air introduced from the outside of the vehicle GC. The air flow meter 22 is a flow meter for measuring the flow rate of air supplied to the internal combustion engine 10 through the intake pipe 20. The flow rate measured by the air flow meter 22 is input to the injection control device 100.

  The throttle valve 23 is a flow rate adjustment valve for adjusting the flow rate of air passing through the intake pipe 20. The opening degree of the throttle valve 23 is adjusted according to the amount of operation of an accelerator pedal (not shown) provided in the vehicle GC, thereby adjusting the air flow rate. The throttle valve 23 is provided with an opening degree sensor 24. The opening degree of the throttle valve 23 is measured by the opening degree sensor 24 and inputted to the injection control device 100.

  The surge tank 25 is a box-shaped container formed in the middle of the intake pipe 20. The intake pipe 20 is branched into a plurality of downstream sides of the surge tank 25, and each branched flow path is connected to each cylinder. The internal space of the surge tank 25 is wider than the internal space in other portions of the intake pipe 20. The surge tank 25 prevents the pressure fluctuation caused by one cylinder from affecting other cylinders. The surge tank 25 is provided with a pressure sensor 26. The pressure in the intake pipe 20 is measured by the pressure sensor 26 and input to the injection control device 100.

  The exhaust pipe 30 is a pipe for discharging the exhaust gas generated in the cylinder of the internal combustion engine 10 to the outside. The upstream end (the left side in FIG. 1) of the exhaust pipe 30 is connected to the internal combustion engine 10. A catalytic converter 31 for purifying exhaust gas is provided in the middle of the exhaust pipe 30 (on the downstream side of the internal combustion engine 10).

  An air-fuel ratio sensor 32 is provided in a portion of the exhaust pipe 30 upstream of the catalytic converter 31. The air-fuel ratio sensor 32 is a sensor for monitoring the oxygen concentration of the exhaust gas passing through the exhaust pipe 30, and the measurement result is input to the injection control device 100. The injection control device 100 controls the amount of fuel injected from the fuel injection valve 40 based on the measurement result of the air-fuel ratio sensor 32 so that the combustion in the internal combustion engine 10 is performed at the stoichiometric air-fuel ratio.

  A specific configuration of the fuel injection valve 40 will be described with reference to FIG. FIG. 2 shows the internal structure of the fuel injection valve 40 in the closed state. The fuel injection valve 40 is configured such that a valve body 420, a movable core 430, a cap 440, and the like are housed in a case 410 formed as a cylindrical container. An injection port 411 that is a fuel outlet is formed at the tip of the case 410 (the lower end in FIG. 2). A valve seat 412 is formed on the inner wall surface of the case 410 and around the injection port 411.

  In the following description, the lower side (injection port 411 side) in FIG. 2 is simply referred to as “lower side”, and the upper side in FIG. 2 is simply referred to as “upper side”.

  The valve body 420 is disposed so as to be movable along the longitudinal direction of the case 410 (the vertical direction in FIG. 2). As shown in FIG. 2, when the position of the valve body 420 is the most closed (downward) position, the lower end of the valve body 420 is in contact with the valve seat 412 and the injection port 411 is blocked. It is in the state. For this reason, fuel is not injected from the injection port 411. As will be described later, when the movable core 430 moves upward and the valve body 420 also moves in the same direction, the lower end of the valve body 420 is separated from the valve seat 412. As a result, fuel is injected from the injection port 411. The fuel injection rate (injection amount per unit time) increases as the valve element 420 moves away from the valve seat 412. In other words, the degree of opening of the fuel injection valve 40 increases as the valve body 420 moves upward and away from the valve seat 412.

  The entire valve body 420 has a substantially cylindrical shape, and is inserted into a through hole 432 formed in the center of the movable core 430. The vicinity of the upper end portion of the valve body 420 is a diameter-enlarged portion 421 having a larger diameter than the other portions. In the state where the fuel injection valve 40 is closed as shown in FIG. 2, the lower surface 422 that is the lower end surface of the enlarged diameter portion 421 is separated from the upper surface 431 that is the upper end surface of the movable core 430. doing.

  A cylindrical body 480 is fixed to a portion of the side surface of the valve body 420 below the movable core 430. The lower part of the cylindrical body 480 has a shape protruding outward. A spring 492 is disposed between the portion and the movable core 430. The cylindrical body 480 and the valve body 420 are biased toward the injection port 411 (downward) by the elastic force of the spring 492.

  The movable core 430 is a substantially cylindrical member formed of a magnetic material such as ferritic stainless steel. As already described, the through hole 432 is formed in the center of the movable core 430, and the valve body 420 is inserted into the through hole 432. The outer diameter of the movable core 430 is substantially equal to the inner diameter of the case 410. The movable core 430 is arranged so as to be movable in the longitudinal direction (vertical direction) of the case 410.

  A cap 440 is disposed above the movable core 430. The cap 440 is a hollow cylindrical container, and its lower side is opened. The cap 440 is disposed so as to cover the enlarged diameter portion 421 of the valve body 420 from the upper side. The vertical dimension of the internal space of the movable core 430 is larger than the vertical dimension of the enlarged diameter portion 421.

  A spring 491 is disposed further above the cap 440. The cap 440 is urged downward by the elastic force of the spring 491. In the state where the fuel injection valve 40 is closed as shown in FIG. 2, the lower end of the cap 440 is in contact with the upper surface 431 of the movable core 430. For this reason, the elastic force of the spring 491 is also transmitted to the movable core 430 through the cap 440. That is, the movable core 430 is also biased downward.

  A fixed core 460 is disposed above the movable core 430. The fixed core 460 is a substantially cylindrical member made of a magnetic material such as ferritic stainless steel, and is fixed to the case 410. A gap is formed between the fixed core 460 and the movable core 430.

  A cylindrical bush 470 is fixed on the inner peripheral side of the fixed core 460. A part of the cap 440 and the enlarged diameter portion 421 is accommodated in the bush 470. The position of the lower end surface 471 of the bush 470 is further below the lower end of the fixed core 460. In the state where the fuel injection valve 40 is closed as shown in FIG. 2, the lower end surface 471 of the bush 470 and the upper surface 431 of the movable core 430 are separated from each other.

  A coil 450 is disposed on the outer peripheral side of the fixed core 460. When the driving current supplied from the injection control device 100 flows through the coil 450, a magnetic circuit is formed in the movable core 430, the fixed core 460, and the case 410. Thereby, an attractive force (electromagnetic force) is generated between the movable core 430 and the fixed core 460, and the movable core 430 receives a force directed toward the fixed core (upper side).

  The valve opening operation of the fuel injection valve 40 will be described with reference to FIGS. 3 and 4. FIG. 3 shows changes in the order from (A), (B), and (C) until the fuel injection valve 40 changes from the closed state to the opened state. Further, in FIG. 4, a change in the position (height) of the valve body 420 is indicated by a line G1, and a change in the position of the movable core 430 is indicated by a line G2.

  The “position of the valve body 420” indicated by the line G1 in FIG. 4 is the height of the lower surface 422 of the valve body 420. Further, the “position of the movable core 430” shown in FIG. 4 is the height of the upper surface 431 of the movable core 430.

  FIG. 3A shows a state in which no drive current is supplied to the fuel injection valve 40 and the fuel injection valve 40 is closed. That is, the fuel injection valve 40 in the closed state as in FIG. 2 is shown. This state is a state before time t10 in FIG. In FIG. 4, the position of the valve body 420 in the valve closed state (height of the lower surface 422) is shown as a position P20. Further, the position of the movable core 430 in the valve closed state (the height of the upper surface 431) is indicated as a position P10.

  When the driving current starts to be supplied from the state shown in FIG. 3A, the electromagnetic force acting on the movable core 430 gradually increases. When the electromagnetic force becomes larger than the elastic force of the spring 491 (more precisely, when it becomes larger than the elastic force of the spring 491 minus the elastic force of the spring 491), the movable core 430 starts to move upward ( Time t10).

  At this time, the valve body 420 receives a downward force due to the pressure of the fuel, but the force is not transmitted to the movable core 430 because the valve body 420 and the movable core 430 are separated from each other. . The movable core 430 is accelerated relatively smoothly toward the upper side, and sufficient kinetic energy is accumulated in the movable core 430.

  Thereafter, as shown in FIG. 3B, the upper surface 431 of the movable core 430 abuts (collises) with the lower surface 422 of the enlarged diameter portion 421 at time t20. Since sufficient kinetic energy is accumulated in the movable core 430, the valve body 420 starts to move upward under a force greater than the fuel pressure. As described above, the fuel injection valve 40 according to this embodiment has a structure in which the movable core 430 and the valve body 420 are separated from each other in the closed state, so that the valve body 420 can be efficiently used even in a relatively high fuel pressure state. Can be moved in the valve opening direction.

  After the state shown in FIG. 3B, the valve body 420 moves upward together with the movable core 430. Thereby, the opening degree of the fuel injection valve 40 increases, and the fuel injection rate also increases accordingly. That is, the state shown in FIG. 3B can be said to be a state in which the fuel injection valve 40 starts to open.

  After that, when the supply of the driving current is continued, the valve body 420 and the movable core 430 move further upward. Eventually, as shown in FIG. 3C, the upper end of the movable range is reached (time t30). In the state of FIG. 3C, the upper surface 431 of the movable core 430 is in contact with the lower end surface 471 of the bush 470. Moreover, since the opening degree of the fuel injection valve 40 is maximized, the fuel injection rate is also maximized. The state shown in FIG. 3C can be said to be a state where the fuel injection valve 40 has been opened. In FIG. 4, the position of the valve body 420 in a state where the valve opening is completed is shown as a position P30.

  When the supply of the driving current is stopped from the state of FIG. 3C, the attractive force generated between the movable core 430 and the fixed core 460 becomes zero. For this reason, the movable core 430 moves downward by the elastic force of the spring 491. Further, the valve body 420 also moves downward due to the elastic force of the spring 492 and the fuel pressure. The fuel injection valve 40 changes in the order of (C), (B), and (A) in FIG. 3 and returns to the closed state.

  With reference to FIG. 5, changes in the drive current supplied to the fuel injection valve 40 will be described. FIG. 5A shows an example of the waveform of the drive pulse generated by the injection control apparatus 100. The drive pulse is a rectangular wave voltage, and the supply of drive current (application of the drive voltage) is performed during the period when the drive pulse is on. In the example of FIG. 5A, the drive pulse is turned on at time t100, and the drive pulse is turned off at subsequent time t130.

  FIG. 5B shows a change in driving current flowing in the coil 450 of the fuel injection valve 40. FIG. 5C shows a change in the driving voltage applied to the fuel injection valve 40 in order to supply the driving current.

  The injection control device 100 includes a high voltage circuit and a battery (both not shown) as a voltage source for generating a driving voltage. As shown in FIG. 5C, after time t100, a high voltage VH from the high voltage circuit is applied to the fuel injection valve 40. As a result, as shown in FIG. 5B, the driving current increases rapidly and finally increases to a maximum current value IH which is a predetermined target value.

  When the magnitude of the driving current reaches the maximum current value IH (time t110), the application of the voltage VH from the high voltage circuit is stopped and the driving voltage becomes zero. As a result, the drive current decreases rapidly after time t110.

  As will be described later, the movable core 430 starts moving from a time point before the time t110, and the movable core 430 moves upward in the period after the time t110. As the movable core 430 moves, the inductance of the fuel injection valve 40 changes. The magnitude of the driving current flowing through the coil 450 is affected by such a change in inductance. Therefore, the slope of the change in the driving current after time t110 varies depending on the moving speed of the movable core 430.

  At time t120 after time t110, the supply of drive current to the fuel injection valve 40 is started again. However, what is applied to the fuel injection valve 40 after time t120 is not the voltage VH from the high voltage circuit but the voltage VL from the battery (<voltage VH). As shown in FIG. 5C, the voltage VL is intermittently applied. As a result, the magnitude of the driving current supplied to the fuel injection valve 40 is maintained in the vicinity of the current value IL (<maximum current value IH).

  FIG. 5D shows the waveform of the voltage generated at the negative terminal of the fuel injection valve 40. After time t130 when the drive pulse is turned off, as shown in FIG. 5D, the drive current is forcibly reduced to 0 by the reflux circuit (not shown) of the injection control device 100. An induced electromotive force (flyback voltage) having a simple waveform is generated at the negative terminal of the fuel injection valve 40. At this time, the movable core 430 moves to the valve closing side (the lower side in FIG. 2), and the inductance in the fuel injection valve 40 changes accordingly. The waveform of the flyback voltage is affected by such a change in inductance.

  FIG. 5E shows a change in the position (height) of the movable core 430. As shown in the figure, the movable core 430 starts to move after the time t100 when the driving voltage starts to be applied. The movable core 430 continues to move after the time t110 when the driving current reaches the maximum current value IH and the application of the driving voltage is stopped, and reaches the position P30 that is closest to the valve opening before and after the time t120. . The movable core 430 is held at the position P30 during the period in which the driving voltage from the battery is applied (period until time t130).

  As described above, the period during which the voltage VH from the high voltage circuit is applied is a period for generating energy necessary to move the movable core 430 and the valve body 420 to the valve opening side. Further, the period during which the voltage VL from the battery is applied is a period for generating energy necessary to hold the movable core 430 and the valve body 420 at the position P30.

  After the time t130 when the supply of the driving current is stopped, the attractive force generated between the movable core 430 and the fixed core 460 decreases and finally becomes zero. As shown in FIG. 5E, the movable core 430 starts to move to the valve closing side at a timing later than the time t130, and returns to the position P10 in the valve closing state.

  In the example shown in FIG. 5, the period during which the drive pulse is on is sufficiently long, and the movable core 430 and the valve body 420 have reached the position P30. That is, the fuel injection valve 40 is operated under an operating condition such that the movable core 430 reaches a position where the opening of the fuel injection valve 40 is maximum.

  However, when the target value of the injection amount is very small, the fuel injection valve 40 may be operated under operating conditions such that the opening of the fuel injection valve 40 does not become maximum. FIG. 6 shows an example of the operation of the fuel injection valve 40 in such a case.

  FIG. 6 (A) shows the waveform of the drive pulse as in FIG. 5 (A). The drive pulse shown in FIG. 6A is turned on at time t100 and then turned off at time t115 before time t130. That is, the width of the drive pulse shown in FIG. 6A is shorter than the width of the drive pulse shown in FIG.

  FIG. 6 (E1) shows the change in the position (height) of the movable core 430 as in FIG. 5 (E). In the example of FIG. 6, since the width of the drive pulse, that is, the period during which the drive current is supplied is short, the movable core 430 does not reach the position P30. As shown in FIG. 6 (E1), the movable core 430 starts moving from the position P10 at time t105, then reaches the position P25 on the valve closing side from the position P30, and then returns to the valve closing side again. Go. In the example of FIG. 6, the time when the movable core 430 returns to the position P10 is shown as time t119.

  As described above, the operating condition in which the movable core 430 does not reach the valve opening side position P30 is also referred to as “partial lift condition” below. On the other hand, as in the example shown in FIG. 5, the operating condition in which the movable core 430 reaches the position P30 closest to the valve opening side is also referred to as “full lift condition” below.

  Even if the width of the drive pulse is constant, the injection amount from the fuel injection valve 40 may not be constant and may vary. In particular, when the fuel injection valve 40 is operated under partial lift conditions, variations in the injection amount are likely to occur.

  FIG. 6 (E2) shows an example of a change in the position of the movable core 430 when the injection amount is small due to the variation. In FIG. 6 (E2), the movable core 430 starts moving at time t106 after time t105. In addition, due to the short period from the start of movement to time t115 when the drive pulse is turned off, the reaching position of the movable core 430 is a position P24 on the valve closing side further than the position P25. After the movable core 430 reaches the position P24, the movable core 430 moves to the valve closing side, and returns to the position P10 at time t118 before time t119.

  The amount of fuel injected from the fuel injection valve 40 is approximately proportional to the length of the period during which the movable core 430 is away from the position P10. In the example of FIG. 6 (E2), since the period is shorter from the period PW20 to the period PW10, the injection amount is smaller than in the case of FIG. 6 (E1).

  Thus, even if the width of the injection pulse shown in FIG. 6 (A) is the same, the behavior of the movable core 430 and the valve body 420 changes due to individual differences, resulting in variations in the fuel injection amount. There is. Variations in the injection amount include variations in the elastic force of the springs 491 and 492 shown in FIG. 2 and gaps formed between the movable core (upper surface 431) and the valve body (lower surface 422) in the valve-closed state ( This is caused by the variation in the size of the "core gap".

  In order to make the injection amount of the fuel injection valve 40 coincide with the target value, the deviation between the actual injection amount and the target value is grasped in advance, and the injection amount is set to the target value by correcting the width of the injection pulse, for example. It needs to be close. As a method for grasping in advance the difference between the actual injection amount and the target value, the valve opening start timing and the valve closing completion timing in the partial lift conditions are estimated, and based on the length of the period between them. It is conceivable to estimate the actual injection amount.

  However, when the valve body 420 starts to move in the valve opening direction, the movement speed is small, and therefore, fluctuations in the driving current due to the movement of the valve body 420 and the movable core 430 hardly occur. Therefore, it is difficult to directly estimate (calculate) the valve opening start timing based on the change in the driving current.

  Therefore, it is conceivable that the actual injection amount is estimated based only on the valve closing completion timing after considering the timing at which the drive pulse is turned on as the valve opening start timing. However, as described below, the variation in the valve opening start timing is relatively large. Therefore, accurate estimation of the valve opening start timing is indispensable for performing correction for making the injection amount coincide with the target value.

  With reference to FIG. 14, the cause of the variation in the valve opening start timing will be described. Three graphs (lines G41, G42, and G43) shown in FIG. 14A show changes in the position of the movable core 430 for each of the three types of fuel injection valves 40 having different core gaps. . A line G41 indicates a change in the position of the movable core 430 in the fuel injection valve 40 having a relatively large core gap. A line G42 indicates a change in the position of the movable core 430 in the fuel injection valve 40 having an average core gap. A line G43 indicates a change in the position of the movable core 430 in the fuel injection valve 40 having a relatively small core gap.

  As shown in FIG. 14A, in the line G43 when the core gap is small, the timing when the movable core 430 reaches the position P20 that is the valve opening position, that is, the valve opening start timing is the earliest. On the other hand, in the line G41 when the core gap is large, the valve opening start timing is the latest.

  In the three graphs (lines G51, G52, G53) shown in FIG. 14B, the strengths of the springs 491 and 492 (the resultant force of the springs in the downward direction due to the difference in spring constant and spring load) are mutually equal. The change of the position of the movable core 430 is shown for each of three different types of fuel injection valves 40. A line G51 indicates a change in the position of the movable core 430 in the fuel injection valve 40 having a relatively large spring force such as the spring 491. A line G52 indicates a change in the position of the movable core 430 in the fuel injection valve 40 in which the spring force of the spring 491 or the like is average. A line G53 indicates a change in the position of the movable core 430 in the fuel injection valve 40 having a relatively small spring force such as the spring 491.

  As shown in FIG. 14B, the valve opening start timing at which the movable core 430 reaches the position P20 is the earliest on the line G53 when the spring force is small. On the other hand, in the line G51 when the spring force is large, the valve opening start timing is the latest.

  FIG. 14C shows the change in the position of the movable core 430 when the variation due to the core gap shown in FIG. 14A and the variation due to the spring force shown in FIG. Variations are shown.

  A line G61 indicates a change in the position of the movable core 430 in the fuel injection valve 40 in which the core gap is relatively large and the spring force of the spring 491 or the like is relatively large. A line G62 indicates a change in the position of the movable core 430 in the fuel injection valve 40 in which the core gap is relatively small and the spring force of the spring 491 or the like is relatively large. A line G63 indicates a change in the position of the movable core 430 in the fuel injection valve 40 in which the core gap is relatively small and the spring force of the spring 491 or the like is relatively small.

  The valve opening start timing at which each of the lines G61, G62, and G63 shown in FIG. 14C reaches the position P20 is different from each other. The valve opening start timing is determined in combination by the variation in the core gap and the variation in the spring force. Therefore, in the fuel injection valve 40 configured as in the present embodiment, that is, in the fuel injection valve 40 configured such that the valve body 420 and the movable core 430 are separated when the valve is closed, the valve opening start timing There is a tendency that the variation of the is particularly large.

  Further, as shown in FIG. 14C, since the waveforms of the line G61 and the like are different from each other, the correlation between the valve opening start timing and the valve closing completion timing is relatively small. For this reason, it is also difficult to estimate the valve opening start timing based on the valve closing completion timing, for example.

  Therefore, the injection control apparatus 100 according to the present embodiment calculates the valve opening start timing based on both the speed of the movable core 430 at the time of valve opening (valve opening speed) and the valve opening completion timing under the full lift condition. I am going to do that. Below, the specific calculation method of the valve opening start timing by the injection control apparatus 100 is demonstrated.

  As illustrated in FIG. 7, the injection control device 100 includes a plurality of functional control blocks (such as the current detection unit 110) for calculating the valve opening start timing.

  The current detector 110 is a part that monitors the magnitude of the drive current that actually flows through the fuel injection valve 40 and acquires the waveform thereof. The acquired waveform of the driving current is input to the speed calculation unit 111 and the first timing calculation unit 112, respectively.

  Based on the waveform of the drive current input from the current detection unit 110, the speed calculation unit 111 is the speed of the movable core 430 at the time of valve opening, that is, the movement of the movable core 430 that moves upward in FIG. This is the part that calculates the speed. The speed calculation unit 111 calculates the speed of the movable core 430 based on the waveform of the driving current acquired under the full lift condition.

  With reference to FIG. 8, a method of calculating the moving speed by the speed calculating unit 111 will be described. FIG. 8 shows an example of the waveform of the drive current after time t100 when the drive pulse is turned on.

  As already described, after the time t110 when the driving voltage is turned off, the driving current rapidly decreases from the maximum current value IH. The decreasing speed varies depending on the moving speed of the movable core 430. This is because the inductance of the fuel injection valve 40 changes with the movement of the movable core 430, thereby changing the driving current.

  A line G11 shows a change in driving current when the moving speed of the movable core 430 is relatively fast. A line G12 shows a change in driving current when the moving speed of the movable core 430 is an average speed. A line G13 shows a change in driving current when the moving speed of the movable core 430 is relatively slow. As shown in FIG. 8, the rate of decrease in the drive current increases as the moving speed of the movable core 430 toward the valve opening increases.

  In the present embodiment, a threshold value ITH smaller than the maximum current value IH is set. The speed calculation unit 111 calculates the length of the period from time t110 when the driving voltage is turned off to the time when the driving current decreases and reaches the threshold value ITH (time t111, t112, t113).

  In the example of FIG. 8, in the line G11 when the moving speed of the movable core 430 is fast, the driving current decreases to the threshold value ITH at time t111 when the period TM1 has elapsed. Further, in the line G12 when the moving speed of the movable core 430 is average, the driving current decreases to the threshold value ITH at time t112 when the period TM2 (> period TM1) has elapsed. Further, in the line G13 when the moving speed of the movable core 430 is slow, the driving current decreases to the threshold value ITH at time t113 when the period TM3 (> period TM2) has elapsed.

  Thus, there is a correlation between the moving speed of the movable core 430 when the valve is opened and the length of the period during which the drive current decreases from the maximum current value IH to the threshold value ITH. In the injection control device 100, the relationship between the two is stored in advance as a map. The speed calculation unit 111 calculates the period TM1 and the like based on the input driving current waveform, and calculates the moving speed of the movable core 430 based on the period TM1 and the map.

  Note that the length of the period TM1 and the like until the drive current reaches the threshold value ITH may be calculated using the time t110 as a reference (start) as described above, but the time t100 when the drive pulse is turned on. May be calculated on the basis of. However, in the latter case, the length of the period TM1 or the like may vary due to variations in the increase rate of the drive current. For this reason, as in the present embodiment, a mode in which the length of the period TM1 or the like is calculated with reference to the time t110 is preferable.

  In addition, the moving speed of the movable core 430 may be calculated under the full lift condition as in the present embodiment, but the moving speed of the movable core 430 can also be calculated under the partial lift condition. However, since the moving time of the movable core 430 is shortened under the partial lift condition, there is a concern that the calculation accuracy of the moving speed is lowered. Therefore, it is preferable to calculate under the full lift condition as in this embodiment.

  The first timing calculation unit 112 in FIG. 7 is based on the waveform of the driving current input from the current detection unit 110, that is, the timing at which the opening of the fuel injection valve 40 becomes maximum, that is, the movable core 430 is most opened. It is a part which calculates the valve opening completion timing which arrives at the position P30 used as the side.

  A method for calculating the valve opening completion timing by the first timing calculation unit 112 will be described with reference to FIG. The items shown in FIGS. 9A to 9E are the same as the items shown in FIGS. 5A to 5E, respectively. However, FIG. 9 differs from the case of FIG. 5 in a part of the waveform of the applied driving voltage. The calculation of the valve opening completion timing by the first timing calculation unit 112 is performed based on the waveform of the driving current acquired under the full lift condition.

  When the valve opening completion timing is calculated, as shown in FIG. 9C, after time t120 at which the voltage VL from the battery starts to be applied, at least until the movable core 430 reaches the position P30. The voltage VL is applied continuously (not intermittently).

  As shown in FIG. 9B, after time t120 when the voltage VL from the battery starts to be applied, the drive current once increases and then gradually decreases. At this time, the movable core 430 continues to move in the valve opening direction. The decrease in the driving current as described above is caused by a change in inductance in the fuel injection valve 40 as the movable core 430 moves.

  When the movable core 430 reaches the position P30 (time t121), the speed of the movable core 430 changes rapidly due to the collision with the bush 470. Due to this, the driving current that has been gradually decreasing starts to increase again after time t121. The first timing calculation unit 112 acquires the timing (time t121) at which the driving current has changed from decrease to increase in this way, and calculates the length of the period TM20 from time t100 to time t121. As shown in FIG. 9E, the timing when the period TM20 has elapsed from the time t100 when the drive pulse is turned on is the “valve opening completion timing”.

  Note that the speed calculation unit 111 calculates the moving speed of the movable core 430 and the first timing calculation unit 112 calculates the valve opening completion timing based on one injection from the fuel injection valve 40. It may be a mode. However, it is preferable that the respective calculations are performed based on different injections as in the present embodiment because the driving voltage pattern can be changed to be advantageous for the calculation.

  Returning to FIG. 7, the description will be continued. The moving speed of the movable core 430 calculated by the speed calculating unit 111 and the valve opening completion timing (period TM20) calculated by the first timing calculating unit 112 are input to the second timing calculating unit 113, respectively. Based on these two pieces of information, the second timing calculation unit 113 calculates a valve opening start timing that is a timing at which the movable core 430 reaches the position P20, that is, a timing at which the fuel injection valve 40 starts to open.

  A method for calculating the valve opening start timing by the second timing calculation unit 113 will be described with reference to FIG. The graph shown in FIG. 10 is a part of FIG. 9E extracted and schematically drawn. Specifically, the change in the position of the movable core 430 in a straight line from the time t111 when the movable core 430 arrives at the position P20 to the time t121 when the movable core 430 arrives at the position P30 is expressed in a straight line. It is a representation. The inclination of the straight line is equal to the moving speed (valve opening speed) of the movable core 430 calculated by the speed calculation unit 111.

When a period from time t100 to time t110 is expressed as a period TM10, the valve opening speed can be expressed by the following equation (1).
Valve opening speed = (P30−P20) / (TM20−TM10) (1)

  Since the dimensions of the components of the fuel injection valve 40 are already known, the value of (P30-P20) in the equation (1) is known. Also, since TM20 is calculated by the speed calculation unit 111, its value is still known. Therefore, the above equation (1) can be solved for TM10. The second timing calculation unit 113 calculates TM10 by solving Equation (1) for TM10. As shown in FIG. 9E, the timing when the period TM10 has elapsed from the time t100 when the drive pulse is turned on is the “valve opening start timing” when the movable core has reached the position P20.

  The voltage detector 120 is a part that monitors the magnitude of the induced electromotive force (flyback voltage) generated at the negative terminal of the fuel injection valve 40 and acquires the waveform thereof. The acquired waveform of the flyback voltage is input to the third timing calculation unit 121. The 3rd timing calculation part 121 is a part which calculates the timing which the movable core 430 returns to the position P10 based on the change (waveform) of a flyback voltage.

  Note that the timing at which the fuel injection valve 40 is closed, that is, the timing at which the movable core 430 moves in the valve closing direction and reaches the position P20 is strictly the timing calculated by the third timing calculation unit 121. Is different. However, the period during which the movable core 430 reaches the position P10 from the position P20 is extremely short, and variations in the length hardly occur. Therefore, the timing (timing at which the movable core 430 returns to the position P10) calculated by the third timing calculation unit 121 will be treated as the valve closing completion timing below.

  A method for calculating the valve closing completion timing by the third timing calculating unit 121 will be described with reference to FIG. The calculation of the valve closing completion timing by the third timing calculation unit 121 is performed based on the waveform of the flyback voltage acquired under the partial lift condition. FIG. 11A shows a waveform of a drive pulse for driving the fuel injection valve 40 under a partial lift condition. The waveform shown in FIG. 11 (A) is the same as that shown in FIG. 6 (A).

  A line G <b> 21 in FIG. 11B illustrates an example of a flyback voltage waveform input from the voltage detection unit 120 to the third timing calculation unit 121.

  The third timing calculation unit 121 calculates two waveforms (line G22, line G23) based on the flyback voltage waveform (line G21). The waveform indicated by the line G22 (hereinafter also referred to as “first waveform G22”) and the waveform indicated by the line G23 (hereinafter also indicated as “second waveform G23”) are both flyback voltages. The waveform is obtained by filtering the waveform with a low-pass filter (not shown). Note that the cutoff frequency f1 of the low-pass filter for generating the first waveform G22 is lower than the frequency of the noise component of the flyback voltage. Further, the cutoff frequency f2 of the low-pass filter for generating the second waveform G23 is further lower than the cutoff frequency f1 of the low-pass filter for generating the first waveform G22.

  FIG. 11C shows a waveform obtained by taking the difference between the first waveform G22 and the second waveform G23. The research conducted by the present inventors has found that the timing corresponding to the inflection point of the waveform thus calculated (time t117) is equal to the timing when the movable core 430 returns to the position P10. Yes.

  Therefore, the third timing calculation unit 121 calculates the waveform of FIG. 11C by taking the difference between the first waveform G22 and the second waveform G23, and then the timing when the waveform exceeds a predetermined threshold VTH ( Time t117) is acquired, and the length of the period TM30 from time t100 to time t117 is calculated. The threshold value VTH is obtained in advance by experiments or the like so as to be a threshold value that overlaps with the inflection point of the waveform in FIG. As shown in FIG. 11C, the timing when the period TM30 has elapsed from the time t100 when the drive pulse is turned on is the “valve closing completion timing”.

  Returning to FIG. 7, the description will be continued. Both the valve opening start timing (period TM20) calculated by the second timing calculation section 113 and the valve closing completion timing (period TM30) calculated by the third timing calculation section 121 are input to the injection amount estimation section 130. Is done. The injection amount estimation unit 130 estimates the fuel injection amount from the fuel injection valve 40 based on these two pieces of information.

  The fuel injection amount under the partial lift condition has a strong positive correlation with the length of the period during which the fuel injection valve 40 is in the open state, that is, the period from the valve opening start timing to the valve closing completion timing. Therefore, in the injection amount estimation unit 130, the valve closing completion timing (period TM30) calculated by the third timing calculation unit 121, the valve opening start timing (period TM20) calculated by the second timing calculation unit 113, The injection amount is estimated based on the difference. There may be a mode in which a map indicating the relationship between the difference and the injection amount is stored in advance (for each condition such as driving voltage), and the injection amount is estimated by referring to the map. The estimated injection amount is input from the injection amount estimation unit 130 to the correction unit 140.

  The correction unit 140 is a part that corrects the injection control amount as necessary so that the difference between the estimated value of the injection amount input from the injection amount estimation unit 130 and the actual injection amount becomes small. The injection control amount is an operation amount when controlling the operation of the fuel injection valve 40. Specifically, the width of the drive pulse (the energization time during which the drive current is supplied), the maximum value of the applied drive voltage (voltage VH from the high voltage circuit), and the maximum of the supplied drive current This is at least one of the values (maximum current value IH). In the present embodiment, the injection amount under the partial lift condition is adjusted by adjusting the width of the drive pulse as the injection control amount.

  The adjustment of the injection amount will be described with reference to FIG. FIG. 12A shows an example of the waveform of the drive pulse generated by the injection control apparatus 100 under the partial lift condition. FIG. 12E3 shows an example of a change in the position (height) of the movable core 430 at that time.

  Note that the waveform shown by the dotted line DL1 in FIG. 12A is the same as the waveform shown in FIG. Further, the waveform indicated by the dotted line DL2 in FIG. 12E3 is the same as the waveform illustrated in FIG. 6E2.

  As indicated by the dotted line DL2 and FIG. 6 (E2), when the maximum reach position of the movable core 430 changes from the position P25 to the position P24 due to the individual difference of the fuel injection valve 40, the movable core 430 changes the position P10. The separated period becomes shorter (changes from the period PW20 to the period PW10). As a result, the fuel injection amount becomes smaller than the target value. As described above, the change in the injection amount as described above is detected as a change in the length of the period from the valve opening start timing to the valve closing completion timing.

  When it is detected that the injection amount deviates from the target value, the correction unit 140 adjusts the injection amount by changing the width of the drive pulse at the next injection. Specifically, the width of the drive pulse is changed so that the length of the period from the valve opening start timing to the valve closing completion timing becomes a length corresponding to the target value of the injection amount.

  In the example of FIG. 12, the timing for turning off the drive pulse is delayed from time t115 to time t116 so that the waveform indicating the change in the position of the movable core 430 changes from the dotted line DL2 to the line G30. Note that the waveform of the line G30 in FIG. 12 (E3) is the same as the waveform in FIG. 6 (E1). That is, it is the same as the waveform when the injection amount becomes the target value. In FIG. 12 (E3), the rising of the dotted line DL2 and the rising of the line G30 are drawn at the same timing.

  In this way, by correcting the injection control amount (drive pulse width) based on the calculated valve opening start timing and valve closing completion timing, it is possible to bring the fuel injection amount in the partial lift condition closer to the target value. It becomes. In the present embodiment, even when the valve opening start timing varies due to the structural variation of the fuel injection valve 40, the current valve opening start timing is accurately calculated, and the injection amount is estimated based on this. In addition, it is possible to appropriately correct the injection control amount.

  The valve opening start timing is calculated under the full lift condition, but the valve opening start timing is the same in both the full lift condition and the partial lift condition. Therefore, even the valve opening start timing calculated under the full lift condition can be used for estimating the injection amount under the partial lift condition.

  The flow of processing executed by the injection control apparatus 100 in order to calculate the valve opening start timing and the like as described above and to correct the injection control amount will be described. A series of processes shown in FIG. 13 is repeatedly executed by the injection control device 100 every time a predetermined period elapses.

  In the first step S01, it is determined whether an execution condition for calculating the valve opening start timing and the like and correcting the injection control amount is satisfied. In the present embodiment, when the internal combustion engine 10 provided with the fuel injection valve 40 is in steady operation, that is, when the output torque of the internal combustion engine 10 is substantially constant and the fluctuation is within a predetermined range. Then, it is determined that the execution condition is satisfied.

  Note that the cooling water temperature of the internal combustion engine 10 (measured value of the cooling water temperature sensor 11) is within a predetermined range, or the fuel pressure at the fuel injection valve 40 is within the predetermined range instead of or in addition to the above conditions. And at least one condition that the target fuel pressure that is the target value of the fuel pressure is constant may be used as the execution condition.

  If the execution condition is satisfied, the process proceeds to step S02. If the execution condition is not satisfied, the series of processes shown in FIG. Thus, since the valve opening start timing is calculated only when the execution condition is satisfied, the valve opening start timing is accurately calculated under stable conditions. In addition, the calculation of the valve opening start timing in each of the plurality of fuel injection valves 40 is performed under substantially the same conditions. As a result, variation in the injection amount of the fuel injection valve 40 between the cylinders is also reliably suppressed.

  In step S02, the speed calculation unit 111 calculates the valve opening speed (speed of the movable core 430). As already described with reference to FIG. 8, the valve opening speed is calculated based on the waveform of the driving current acquired under the full lift condition.

  In step S03 following step S02, the first timing calculation unit 112 calculates the valve opening completion timing. As already described with reference to FIG. 9, the valve opening completion timing is also calculated based on the waveform of the driving current acquired under the full lift condition.

  In step S04 following step S03, the valve opening start timing is calculated by the second timing calculation unit 113. As already described with reference to FIG. 10, the valve opening start timing is calculated based on both the valve opening speed calculated in step S02 and the valve opening completion timing calculated in step S03.

  In step S05 following step S04, the valve closing completion timing is calculated by the third timing calculator 121. As already described with reference to FIG. 11, the valve closing completion timing is calculated based on the waveform of the flyback voltage acquired under the partial lift condition.

  In step S06 following step S05, the length of the period (valve opening period) from the valve opening start timing to the valve closing completion timing is calculated. That is, the length of the period during which fuel is injected is calculated by subtracting the valve opening start timing calculated in step S04 from the valve closing completion timing calculated in step S05.

  In step S07 following step S06, the injection amount estimation unit 130 estimates the injection amount. As already described, the injection amount is estimated based on a map showing the relationship between the length of the valve opening period and the injection amount.

  In step S08 following step S07, the correction of the injection control amount (drive pulse width) by the correction unit 140 is performed. As already described with reference to FIG. 12, the injection control amount of the fuel injection valve 40 under the partial lift condition is corrected here.

  The calculation of the valve opening start timing and the correction of the injection control amount according to the series of procedures described above are executed for each cylinder included in the vehicle GC. That is, the injection control amount is corrected for all the fuel injection valves 40. This not only suppresses variations in the injection amount of the single fuel injection valve 40 (changes over time) but also suppresses variations in the injection amount of the fuel injection valve 40 between cylinders.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, but can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

GC: vehicle 40: fuel injection valve 100: injection control device 110: current detection unit 111: speed calculation unit 112: first timing calculation unit 113: second timing calculation unit 121: third timing calculation unit 130: injection amount estimation unit

Claims (13)

An injection control device (100) for controlling the operation of a fuel injection valve (40) driven by electromagnetic force,
A current detector (110) for detecting a driving current supplied to the fuel injection valve;
A speed calculation unit (111) that calculates a valve opening speed of the fuel injection valve based on a change in the driving current when the fuel injection valve is performing a valve opening operation;
A first timing calculator (112) that calculates a valve opening completion timing that is a timing at which the opening of the fuel injection valve is maximized,
A second timing calculation unit (113) that calculates a valve opening start timing that is a timing at which the fuel injection valve starts to open based on the calculated valve opening speed and the valve opening completion timing ;
The speed calculation unit is configured to calculate the valve opening speed based on a length of a period from a predetermined timing to a timing when the driving current decreases from a maximum value and falls below a predetermined threshold. An injection control device.   2. The injection control device according to claim 1, wherein the first timing calculation unit calculates the valve opening completion timing based on a change in the driving current. A third timing calculation unit (121) for calculating a valve closing completion timing which is a timing when the fuel injection valve is closed;
Injection that estimates an injection amount when fuel is injected under an operating condition in which the opening of the fuel injection valve does not become maximum based on a length of a period from the valve opening start timing to the valve closing completion timing The injection control device according to claim 1, further comprising a quantity estimation unit (130).   The injection control device according to claim 3, wherein the third timing calculation unit calculates the valve closing completion timing based on a change in induced electromotive force generated in the fuel injection valve.   Based on the injection amount estimated by the injection amount estimation unit, the injection control amount is corrected when fuel is injected under operating conditions where the opening of the fuel injection valve does not become maximum. The injection control device according to claim 3.   The injection control amount includes an energization time which is a time during which the driving current is supplied to the fuel injection valve, a maximum value of a voltage applied to the fuel injection valve for supplying the driving current, and the fuel The injection control device according to claim 5, wherein the injection control device is at least one of a maximum value of the driving current supplied to the injection valve. The injection control apparatus according to claim 1 , wherein the predetermined timing is a timing at which the driving current reaches a maximum value.   The correction of the injection control amount is performed such that a length of a period from the valve opening start timing to the valve closing completion timing becomes a length corresponding to a target value of the injection amount. 5. The injection control device according to 5.   The injection control device according to claim 1, wherein the valve opening speed is calculated by the speed calculation unit under an operating condition in which an opening degree of the fuel injection valve is maximized.   The internal combustion engine provided with the fuel injection valve is in steady operation, the coolant temperature of the internal combustion engine is within a predetermined range, the fuel pressure at the fuel injection valve is within a predetermined range, and the fuel pressure 2. The valve opening start timing is calculated by the second timing calculation unit in a state where at least one of a target fuel pressure that is a target value is constant is satisfied. The injection control device according to 1. The fuel injection valve is
A movable core driven by electromagnetic force generated by the driving current;
A valve body that receives a force from the movable core and moves, and changes the opening degree by the movement of the valve body,
In the state where the fuel injection valve is closed, the movable core and the valve body are in a state of being separated from each other,
When the fuel injection valve is opened, first, only the movable core starts to move, and then the valve body starts moving when the movable core comes into contact with the valve body. The injection control device according to claim 1. 2. The injection control device according to claim 1, wherein the speed calculation unit detects the valve opening speed based on the driving current after application of a voltage for opening the fuel injection valve is stopped. 3. An injection control device (100) for controlling the operation of a fuel injection valve (40) driven by electromagnetic force,
A current detector (110) for detecting a driving current supplied to the fuel injection valve;
A speed calculation unit (111) that calculates a valve opening speed of the fuel injection valve based on a change in the driving current when the fuel injection valve is performing a valve opening operation;
A first timing calculator (112) that calculates a valve opening completion timing that is a timing at which the opening of the fuel injection valve is maximized,
A second timing calculation unit (113) that calculates a valve opening start timing that is a timing at which the fuel injection valve starts to open based on the calculated valve opening speed and the valve opening completion timing ;
A third timing calculation unit (121) for calculating a valve closing completion timing which is a timing when the fuel injection valve is closed;
Injection that estimates an injection amount when fuel is injected under an operating condition in which the opening of the fuel injection valve does not become maximum based on a length of a period from the valve opening start timing to the valve closing completion timing A quantity estimation unit (130),
Based on the injection amount estimated by the injection amount estimating section, have rows correction of the injection control amount at the time of opening of the fuel injection valve is performed the injection of the fuel in the operating condition does not become maximum,
The injection control apparatus corrects the injection control amount so that a length of a period from the valve opening start timing to the valve closing completion timing is a length corresponding to a target value of the injection amount. .

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