JP2016033343A - Fuel injection control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the learning opportunity of current-carrying time without executing forced split injections.SOLUTION: An ECU 30 (fuel injection control unit) comprises: a map storage unit 43; a current-carrying-time setting unit 42; a detection circuit 52; a learning unit 44; and a correction unit 46. The map storage unit 43 stores an adaptive value of current carrying time Ti corresponding to a demanded injection quantity. The current-carrying-time setting unit 42 sets the current carrying time Ti on the basis of the stored adaptive value. The detection circuit 52 detects a behavior of a valve element 11. The learning unit 44 learns a detection result as correction data. The correction unit 46 corrects the current carrying time set by the current-carrying-time setting unit 42 on the basis of the learned correction data. If the current carrying time Ti is time within a predetermined range among time for partial lift injection, the learning unit 44 implements learning.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel injection control device that controls the operation of a fuel injection valve that injects fuel used for combustion in an internal combustion engine.

  A conventional control device for controlling this type of fuel injection valve stores in advance a map representing the relationship (Ti-Q characteristic) between the energization time Ti and the injection amount Q to the fuel injection valve, and the required injection amount. Is set with reference to the map. In recent years, particularly in a direct-injection internal combustion engine, it is required to make the minimum value of the controllable injection amount as small as possible.

  Therefore, in the control device described in Patent Document 1, partial lift injection is performed to start the valve closing operation before reaching the maximum valve opening position after the valve element starts the valve opening operation. According to this, the minimum value of the injection amount can be reduced as compared with the control device limited to the full lift injection that starts the valve closing operation after reaching the maximum valve opening position.

JP 2013-2400 A

  However, in the partial lift injection, the machine difference variation of the Ti-Q characteristic appears remarkably. Therefore, the present inventors detect the timing at which the valve body is closed after the energization is completed when the energization time Ti is a specific time in the partial lift injection region, and Ti-Q is determined according to the detection result. We considered correcting the map. However, there is little opportunity for the energization time Ti to be a specific time, so sufficient learning cannot be performed.

  In order to solve this problem, the present inventors also consider performing divided injection in which the required injection amount is divided into a plurality of times and increasing the learning opportunity by setting one of the injections at a specific time. did. However, when such divided injection is performed, the combustion state differs from the desired state, leading to deterioration of exhaust emission and fuel consumption.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection control device that increases the learning opportunity of the energization time without performing forced split injection.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with the specific means described in the embodiments described later, and do not limit the technical scope of the invention. .

  One of the disclosed inventions is a fuel injection valve (injecting fuel used for combustion of an internal combustion engine) by opening the valve body (11) by the valve opening force generated by the electric actuator (12, 13, 14). It is assumed that the fuel injection control device (30) is applied to 10). Storage means (43) for storing an adapted value of the energization time (Ti) to the electric actuator corresponding to the required injection amount which is the fuel injection amount required during one combustion cycle of the internal combustion engine; The energization time setting means (42) for setting the energization time to the electric actuator based on the adaptation value stored in the above, the detection means (52) for detecting the behavior of the valve body, and the detection results of the detection means Learning means (44) that learns as correction data to be used for the correction, and correction means (46) that corrects the fitness value based on the correction data learned by the learning means. The energization time of the electric actuator is a time of a predetermined range (Wa) of partial lift injection in which the valve closing operation is started before reaching the maximum valve opening position after the valve body starts the valve opening operation. If there is, learning by the learning means is performed.

  According to the present invention, if the energization time to the electric actuator is within a predetermined range in which partial lift injection is to be performed, the behavior of the valve element is detected, and the adaptation value of the energization time is determined based on the detection result. to correct. Therefore, the learning of the correction data based on the relationship between the energization time and the behavior of the valve body is not limited to the case where the energization time is a specific time, but is performed within a predetermined range. Therefore, the learning opportunities for the energization time can be increased without performing forced split injection.

1 is a schematic diagram showing a fuel injection control device according to an embodiment of the present invention and a fuel injection valve that is a control target thereof. The figure which shows the full lift state of a fuel injection valve. The figure which shows the partial lift state of a fuel injection valve. The characteristic map which shows the relationship between the electricity supply time Ti and the injection quantity Q. The test result showing the correlation between the measurement time of the valve closing timing and the energization time Ti and the spring characteristics. The flowchart which shows the process sequence of learning by the fuel-injection control apparatus shown in FIG.

  Hereinafter, a plurality of modes for carrying out the invention will be described with reference to the drawings. In each embodiment, portions corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals and redundant description may be omitted. In each embodiment, when only a part of the configuration is described, the other configurations described above can be applied to other portions of the configuration.

  A fuel injection valve 10 shown in FIG. 1 is mounted on an ignition internal combustion engine (gasoline engine), and directly injects fuel into each combustion chamber of a multi-cylinder engine. The fuel supplied to the fuel injection valve 10 is pumped by the fuel pump 20, and the fuel pump 20 is driven by the rotational driving force of the engine.

  As shown in FIGS. 2 and 3, the fuel injection valve 10 includes a valve body 11, a coil 12, a fixed core 13, a movable core 14, a spring 15, a body 16 that accommodates them, and the like. . Inside the body 16 are formed a fuel passage, an injection hole located at the downstream end of the fuel passage, and a seating surface on which the valve body 11 is seated. When the valve body 11 is closed so that the seat surface formed on the valve body 11 is seated on the seating surface, fuel injection from the injection hole is stopped. When the valve body 11 is opened (lifted up) so as to separate the seat surface from the seating surface, fuel is injected from the injection hole.

  The fixed core 13 and the movable core 14 form a magnetic circuit serving as a path for magnetic flux generated by energization of the coil 12. When the coil 12 is energized to generate an electromagnetic attractive force on the fixed core 13, the movable core 14 is attracted to the fixed core 13 by this electromagnetic attractive force. As a result, the valve body 11 connected to the movable core 14 is lifted up (opening operation) against the elastic force of the spring 15 and the fuel pressure closing force. On the other hand, when the energization of the coil 12 is stopped, the valve element 11 is closed together with the movable core 14 by the elastic force of the spring 15. The spring 15 is coiled and elastically deforms in the direction of the central axis of the fuel injection valve 10 (vertical direction in FIG. 2). The elastic force of the spring 15 is applied to the valve body 11 on the valve closing side. The spring 15 provides an elastic means for applying an elastic force to the valve body 11 to perform a valve closing operation.

  1, the electronic control unit (ECU 30) controls the combustion state of the engine by controlling the operation of the throttle valve, the ignition plug, and the fuel injection valve 10 that control the intake air amount. Control power and exhaust emissions. Therefore, the ECU 30 provides a fuel injection control device that controls the operation of the fuel injection valve 10. The ECU 30 and the fuel injection valve 10 provide a fuel injection system that injects an optimal amount of fuel at an optimal timing.

  The ECU 30 includes a microcomputer (microcomputer 40) and an integrated circuit (IC50). The microcomputer 40 includes a central processing unit (CPU) and a memory, and the CPU executes various processes according to a program stored in advance. Thereby, the microcomputer 40 functions as a required injection amount setting unit 41, an energization time setting unit 42, a map storage unit 43, a learning unit 44, a spring characteristic estimation unit 45, and a correction unit 46, which will be described later.

  The required injection amount setting unit 41 calculates the required injection amount of fuel based on the accelerator pedal depression amount, engine load, engine speed, and the like by the vehicle driver. This required injection amount is the fuel injection amount required for each cylinder during one combustion cycle, and corresponds to the amount injected when the valve element 11 is opened once.

  The energization time setting unit 42 sets an energization time Ti for the coil 12 corresponding to the required injection amount. The adaptation value of the energization time Ti corresponding to the required injection amount is stored in the map storage unit 43 in the format of maps M1, M2, and M3 shown in FIG. The map storage unit 43 stores a plurality of types of maps M1, M2, and M3. The map indicated by the reference symbol M1 indicates a conforming value assuming a nominal fuel injection valve 10. The maps indicated by reference numerals M2 and M3 indicate the appropriate values when the characteristic value of the spring 15 is different from that of the nominal product.

  Specifically, in the case of a spring characteristic in which the elastic coefficient of the spring 15 is large and the elastic force that presses the valve element 11 toward the valve closing side is large, the energization to the coil 12 is stopped and then the valve element 11 is closed. Since the operating speed is fast, the actual valve opening time is shortened. Therefore, the injection amount Q is reduced as indicated by the symbol M2. On the other hand, in the case of spring characteristics in which the elastic coefficient of the spring 15 is small and the elastic force that presses the valve body 11 toward the valve closing side is small, the valve closing operation speed of the valve body 11 is reduced after the energization to the coil 12 is stopped. Since it is slow, the actual valve opening time becomes longer. Therefore, the injection amount Q increases as indicated by the symbol M3.

  If the spring characteristic estimation unit 45 estimates that the elastic coefficient of the spring 15 is the spring characteristic of the nominal product, the correction time is not corrected by the correction unit 46, and the energization time set based on the map M1 assuming the nominal product. The energization time to the coil 12 is controlled by the conforming value of Ti. Specifically, a pulse signal having a pulse-on length corresponding to the energization time Ti is output from the microcomputer 40 to the IC 50 as an ejection pulse signal. The drive circuit 51 included in the IC 50 applies a predetermined voltage to the coil 12 during the ON period of the ejection pulse signal. Therefore, it can be said that the injection pulse signal commands the injection start timing and the injection amount by commanding the energization start timing and the energization time Ti.

  If it is estimated by the spring characteristic estimation unit 45 that the spring characteristic is larger than the nominal product by a predetermined elastic force, the adaptation value based on the map M1 set by the energization time setting unit 42 is changed to the adaptation value based on the map M2. To correct. Alternatively, it instructs the energization time setting unit 42 to set an appropriate value based on the map M2. If it is estimated by the spring characteristic estimation unit 45 that the spring characteristic is smaller than the nominal product by a predetermined elastic force, the adaptation value based on the map M1 set by the energization time setting unit 42 is changed to the adaptation value based on the map M3. To correct. Alternatively, it instructs the energization time setting unit 42 to set an appropriate value based on the map M3. In short, the correction amount by the correction unit 46 corresponds to a deviation amount between the energization time Ti based on the nominal product map M1 and the energization time Ti based on the maps M2 and M3.

  An injection characteristic (Ti-Q characteristic) indicating the relationship between the energization time Ti to the coil 12 and the fuel injection amount Q from the nozzle hole is obtained by testing in advance, and the map memory is stored based on the test result. Maps M1, M2, and M3 stored in the unit 43 are created. Further, the Ti-Q characteristic varies depending on the pressure of the fuel supplied to the fuel injection valve 10 (supply fuel pressure). Therefore, the maps M1, M2, and M3 are created and stored for each supply fuel pressure. The microcomputer 40 acquires the supply fuel pressure detected by the fuel pressure sensor 21. The energization time setting unit 42 and the correction unit 46 set and correct the energization time Ti using the maps M1, M2, and M3 corresponding to the acquired supply fuel pressure.

  The fuel injection valve 10 operates in the mode of full lift injection shown in FIG. 2 when the energization time Ti is sufficiently long, and operates in the mode of partial lift injection shown in FIG. 3 when the energization time Ti is short. . In the full lift injection, the valve body 11 opens to the full lift position (maximum valve opening position) (see FIG. 2B), and then closes. The full lift position is a position where the movable core 14 comes into contact with the fixed core 13. On the other hand, in the partial lift injection, after the valve body 11 starts the valve opening operation, the valve closing operation is started in a state where the full lift position has not been reached (see FIG. 3B).

  The injection characteristics (Ti-Q characteristics) shown in the map M1 in FIG. 4 indicate that the valve element 11 starts the valve opening operation at time t1 from the start of energization. Then, at time t2 after time t1, the valve body 11 has reached the full lift position. Therefore, in the region (partial lift region) from the time t1 to the time t2 in the energization time Ti, the fuel injection valve 10 operates in the form of partial lift injection. On the other hand, in the region (full lift region) after the time t2 in the energization time Ti, the fuel injection valve 10 operates in the form of full lift injection.

  When the movable core 14 collides with the fixed core 13 at the time t2, a bounce phenomenon occurs in which the movable core 14 collides with the fixed core 13 for a moment after the collision. Then, since the valve body 11 also bounces together with the movable core 14, the nozzle hole temporarily repeats opening and closing. Therefore, in the full lift region, the Ti-Q characteristic shown in FIG. 4 is a straight line in the region (third region) from the time point t2 until the predetermined time elapses. As a result, the Ti-Q characteristic has a pulsating waveform.

  As shown in FIG. 4, the inclination of the Ti-Q characteristic line in the partial lift region is larger than the inclination in the full lift region. Therefore, the deviation of the injection amount Q due to the deviation of the energization time Ti appears greatly in the partial lift region. Therefore, it is required to accurately control the energization time Ti in the partial lift region.

  The voltage Vm at the minus terminal of the coil 12 is input to the detection circuit 52 included in the IC 50. This voltage Vm has a waveform that gradually decreases as the valve element is closed. However, a pulsation waveform in which the voltage Vm temporarily rises appears in the gradually decreasing waveform. The appearance of this pulsation waveform is caused by the operation being stopped when the valve element 11 that is in the valve closing operation reaches the valve closing position. That is, it can be said that the appearance timing of the pulsation waveform is the valve closing timing. In view of this point, the detection circuit 52 detects the timing at which the pulsation waveform appears in the waveform of the voltage Vm, and detects the detection timing as the valve closing timing.

  Specifically, the detection circuit 52 measures the time from the start of energization to the coil 12 to the current pulsation waveform output time (valve closing time), and outputs the measurement time Tc to the microcomputer 40 as the valve closing timing detection result. To do. Note that the stronger the elastic force of the spring 15 provided in the fuel injection valve 10, the faster the valve closing operation speed of the valve body 11, so that the time required from the stop of energization to the coil 12 to the valve closing becomes shorter, and the measurement time Tc Becomes shorter.

  The learning unit 44 by the microcomputer 40 learns the relationship between the energization time Ti by the injection pulse signal output from the microcomputer 40 to the IC 50 and the measurement time Tc acquired by the microcomputer 40 from the detection circuit 52. A solid line L1 illustrated in FIG. 5 indicates a learning result when the fuel injection valve 10 is a nominal product. When the elastic force of the spring 15 is strong, the measurement time Tc is shortened as described above, so that the learning result illustrated by the solid line L2 is obtained. On the other hand, when the elastic force of the spring 15 is weak, the measurement time Tc becomes long, so that the learning result illustrated by the solid line L3 is obtained. Therefore, it can be said that the learning result by the learning unit 44 shows the characteristic of the elastic force of the spring 15.

  The spring characteristic estimation unit 45 estimates the spring characteristic of the fuel injection valve 10 by estimating which of the solid lines L1, L2, and L3 is close to the learning result by the learning unit 44, and according to the estimated spring characteristic The estimation result of the spring characteristic is output to the correction unit 46 so that the correction unit 46 executes the correction. Specifically, when the coordinate point on the graph of FIG. 5 of the learned measurement time Tc and energization time Ti is close to the solid line L1, it is estimated that the spring characteristics of the nominal product. On the other hand, when the coordinate point is close to the solid line L2, it is estimated that the spring characteristic is strong, and when it is close to the solid line L3, it is estimated that the spring characteristic is weak.

  The correction unit 46 corrects the energization time Ti set by the energization time setting unit 42 based on the estimation result by the spring characteristic estimation unit 45. Specifically, when it is estimated that the spring characteristics of the nominal product, the energization time Ti is set based on the map M1. That is, the correction by the correction unit 46 is not performed. If it is estimated that the spring characteristic is strong, the energization time Ti is corrected based on the map M2. When it is estimated that the spring characteristic is weak in the elastic force, the energization time Ti is corrected based on the map M3.

  When the coordinate points obtained by learning are located between a plurality of solid lines L1, L2, and L3 shown in FIG. 5, spring characteristics are estimated by linear interpolation, and a plurality of maps M1, M2, and M3 are linearly interpolated. Thus, the energization time Ti is corrected.

  FIG. 6 is a flowchart showing a procedure relating to the above-described learning, and the process of FIG. 6 is repeatedly executed by the microcomputer 40 every time an injection pulse signal is output. 6 is performed for each fuel injection valve 10 provided in each cylinder of the multi-cylinder engine.

  First, in step S10 of FIG. 6, it is determined whether or not partial lift injection is to be performed. Specifically, it is determined whether the energization time Ti related to the injection pulse signal output from the microcomputer 40 is in the partial lift region. When it is determined that the partial lift injection is to be performed (S10: YES), in the subsequent step S11, the valve closing timing is detected. Specifically, the signal of the measurement time Tc output from the detection circuit 52 is acquired.

  In a succeeding step S12, it is determined whether or not a learning execution condition is satisfied. For example, when the fuel temperature exceeds a predetermined range and is low or high, it is considered that the Ti-Q characteristic has changed due to the fuel viscosity exceeding an assumed state. It is determined that the learning execution condition is not satisfied. Further, when the engine operating state changes suddenly, it is determined that the learning execution condition is not satisfied. For example, when the change amount per predetermined time of the engine load or the engine speed exceeds a threshold value, it is determined that the engine operating state has suddenly changed.

  Further, when the energization time Ti is the first region W1 or the second region W2 shown in FIG. 4, it is determined that the learning execution condition is not satisfied. In other words, it is determined that the learning execution condition is satisfied when the energization time Ti is the predetermined range Wa excluding the first region W1 and the second region W2 in the partial lift region. The first region W1 is a region having a time shorter than the first predetermined time in the partial lift region. The second area W2 is an area of the partial lift area that is longer than the second predetermined time. The second predetermined time is longer than the first predetermined time.

  When it is determined that the learning execution condition is satisfied (S12: YES), the learning value in the learning unit 44 is updated in the subsequent step S13. Specifically, coordinate points (learned values) shown in FIG. 5 are added. Further, when different measurement times Tc are acquired for the same energization time Ti, the latest measurement time Tc is rewritten.

  In subsequent step S14, the relationship between the plurality of learning values and a plurality of types of sample data stored in advance in the microcomputer 40, that is, solid lines L1, L2, and L3 is estimated. Specifically, it is estimated which of the solid lines L1, L2, and L3 is closer to the learning value. In the subsequent step S15, the spring characteristic deviation is estimated. Specifically, it is estimated which of a plurality of types of Ti-Q characteristics stored in advance in the microcomputer 40 corresponds.

  In the subsequent step S16, a deviation between the energization time Ti for the required injection amount in the nominal product and the energization time Ti for the required injection amount in the estimated spring characteristics is estimated. In subsequent step S17, the deviation amount of the energization time Ti estimated in step S16 is calculated as a correction amount. If it is determined in step S10 that partial lift injection is not performed (S10: NO), or if it is determined in step S12 that the learning execution condition is not satisfied (S12: NO), the detection circuit The measurement time Tc detected at 52 is reset.

  As described above, according to the present embodiment, if the energization time Ti is within the predetermined range Wa in which the partial lift injection is performed, the time until the valve body 11 is closed (measurement time Tc) is detected. Then, based on the detection result, the matching value of the energization time Ti is corrected. Therefore, the learning value based on the relationship between the energization time Ti and the behavior of the valve body 11 (measurement time Tc) is not limited to the case where the energization time Ti is a specific time, and is implemented within the predetermined range Wa. Become. Therefore, the learning opportunities for the energization time Ti can be increased without performing forced split injection.

  Here, as described above, the Ti-Q characteristic varies depending on the difference in the elastic characteristic of the spring 15. However, the Ti-Q characteristic depends on the difference in the viscosity of the fuel due to the properties of the fuel and the temperature of the coil 12. It also differs depending on the difference in coil resistance. However, among these various factors, the difference in the elastic characteristics of the spring 15 has the greatest influence on the Ti-Q characteristics.

  Based on this knowledge, in this embodiment, the fuel injection valve 10 has the spring 15, and the elastic characteristic of the spring 15 is estimated based on the learning value (correction data) learned by the learning unit 44 (learning means). A spring characteristic estimation unit 45 (characteristic estimation means). Then, the correction unit 46 (correction unit) sets a correction amount for the matching value of the energization time Ti based on the estimation result by the spring characteristic estimation unit 45. Therefore, the correction can be performed with higher accuracy than in the case where the correction amount is set by estimating the viscosity of the fuel and the coil resistance value.

  Here, in the first region W <b> 1 shorter than the first predetermined time in the energization time Ti, as shown in FIG. 4, the variation in Ti-Q characteristics due to the difference in spring characteristics does not occur. In this embodiment in view of this point, the predetermined range Wa of the energization time Ti in which learning is performed is set to a range excluding the first region W1. Therefore, it can suppress that the estimation precision of a spring characteristic falls by the learning value of 1st area | region W1, and can improve the precision of correction | amendment by extension.

  Further, in the second region W2 that is longer than the second predetermined time in the energization time Ti, the Ti-Q characteristic has a pulsating waveform due to the bound phenomenon described above. In this embodiment in view of this point, the predetermined range Wa of the energization time Ti in which learning is executed is set to a range excluding the second region W2. Therefore, it can suppress that the estimation precision of a spring characteristic falls by the learning value of 2nd area | region W2, and can improve the precision of correction | amendment by extension.

  Furthermore, in this embodiment, the map memory | storage part 43 distinguishes and memorize | stores a suitable value for every supply fuel pressure. The energization time setting unit 42 sets the energization time Ti based on a conforming value corresponding to the supply fuel pressure at the time of fuel injection. The learning unit 44 learns by distinguishing correction data for each supply fuel pressure detected by the detection circuit 52. As described above, since the Ti-Q characteristic varies depending on the supply fuel pressure, a suitable value is distinguished and stored for each supply fuel pressure, the energization time Ti is set, and learning is also performed separately for each supply fuel pressure. According to the embodiment, learning accuracy can be improved, and the injection amount can be controlled with high accuracy.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made as illustrated below. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

  In the embodiment shown in FIG. 1, the detection circuit 52 detects the valve closing timing of the valve element 11 based on the change in the voltage Vm at the minus terminal of the coil 12. On the other hand, the valve closing timing of the valve body 11 may be detected based on a change in the current flowing through the coil 12.

  In the embodiment shown in FIG. 4, learning in the first region W1 and the second region W2 is prohibited, but learning in these regions may be performed. Alternatively, learning may be performed by setting a small weight for the learning value in the first region W1 and the second region W2, and setting a large weight for the learning value in the predetermined range Wa.

  In the embodiment shown in FIG. 1, the valve closing timing is detected by detecting the pulsation generated in the voltage waveform when the valve body 11 is closed. However, the present invention is limited to such behavior detection of the valve body 11. Is not to be done. For example, the lift amount of the valve body 11 may be detected by a lift sensor. Alternatively, the pressure in the combustion chamber of the engine (in-cylinder pressure) may be detected by an in-cylinder pressure sensor, and the injection amount may be estimated based on the detected value. Or you may detect the behavior of the valve body 11 based on the change of the supply fuel pressure which arises with injection. In short, specific examples of the physical quantity correlated with the injection quantity include the lift quantity, the in-cylinder pressure, the supply fuel pressure and the like in addition to the valve closing timing.

  In the above embodiment, the coil 12, the fixed core 13, and the movable core 14 provide an electric actuator that opens the valve body 11. On the other hand, a piezoelectric element may be used as an electric actuator.

  In the embodiment shown in FIG. 1, the fuel injection valve 10 is attached to the cylinder head, but the fuel injection valve attached to the cylinder block may be applied. In the above embodiment, the fuel injection valve 10 mounted on the ignition type internal combustion engine (gasoline engine) is applied, but the fuel injection valve mounted on the compression ignition type internal combustion engine (diesel engine) is used. It may be a target. Furthermore, in the above-described embodiment, the fuel injection valve that directly injects fuel into the combustion chamber is the control target.

  In the above embodiment, the various means and functions provided by the fuel injection control device (ECU 30) are provided by the software of the microcomputer 40, but may be provided by software and hardware or a combination thereof. For example, various means by the microcomputer 40 may be configured by an analog circuit. Alternatively, the detection means provided by the detection circuit 52 of the IC 50 may be configured by software of the microcomputer 40.

  DESCRIPTION OF SYMBOLS 12 ... Coil (electric actuator), 13 ... Fixed core (electric actuator), 14 ... Movable core (electric actuator), 30 ... ECU (fuel injection control apparatus), 42 ... Energization time setting part (energization time setting means), 43 ... Map storage unit (storage unit), 44 ... Learning unit (learning unit), 46 ... Correction unit (correction unit), 52 ... Detection circuit (detection unit), Ti ... Energizing time, Wa ... Predetermined range.

One of the disclosed inventions is a fuel injection valve (injecting fuel used for combustion of an internal combustion engine) by opening the valve body (11) by the valve opening force generated by the electric actuator (12, 13, 14). It is assumed that the fuel injection control device (30) is applied to 10). Storage means (43) for storing an adapted value of the energization time (Ti) to the electric actuator corresponding to the required injection amount which is the fuel injection amount required during one combustion cycle of the internal combustion engine; The energization time setting means (42) for setting the energization time to the electric actuator based on the adaptation value stored in the above, the detection means (52) for detecting the behavior of the valve body, and the detection results of the detection means Learning means (44) that learns as correction data used for the correction, and correction means (46) that corrects the energization time set by the energization time setting means based on the correction data learned by the learning means. The energization time of the electric actuator is a time of a predetermined range (Wa) of partial lift injection in which the valve closing operation is started before reaching the maximum valve opening position after the valve body starts the valve opening operation. If there is, learning by the learning means is performed.

According to the present invention, energization time of the electric actuator, if the time of the predetermined range to be able to implement the partial lift injection, detects the behavior of the valve body, it is corrected between energization on the basis of the detection result . Therefore, the learning of the correction data based on the relationship between the energization time and the behavior of the valve body is not limited to the case where the energization time is a specific time, but is performed within a predetermined range. Therefore, the learning opportunities for the energization time can be increased without performing forced split injection.

As described above, according to the present embodiment, if the energization time Ti is within the predetermined range Wa in which the partial lift injection is performed, the time until the valve body 11 is closed (measurement time Tc) is detected. Then, the energization time Ti is corrected based on the detection result. Therefore, the learning value based on the relationship between the energization time Ti and the behavior of the valve body 11 (measurement time Tc) is not limited to the case where the energization time Ti is a specific time, and is implemented within the predetermined range Wa. Become. Therefore, the learning opportunities for the energization time Ti can be increased without performing forced split injection.

Based on this knowledge, in this embodiment, the fuel injection valve 10 has the spring 15, and the elastic characteristic of the spring 15 is estimated based on the learning value (correction data) learned by the learning unit 44 (learning means). A spring characteristic estimation unit 45 (characteristic estimation means). Then, the correction unit 46 (correcting means), based on the estimation result by the spring characteristic estimating unit 45 sets the correction amount against the energizing time T i. Therefore, the correction can be performed with higher accuracy than in the case where the correction amount is set by estimating the viscosity of the fuel and the coil resistance value.

Claims (5)

Fuel injection applied to the fuel injection valve (10) for injecting fuel used for combustion of the internal combustion engine by opening the valve body (11) by the valve opening force generated by the electric actuator (12, 13, 14) In the control device (30),
Storage means (43) for storing a conforming value of the energization time (Ti) to the electric actuator corresponding to a required injection amount which is a fuel injection amount required during one combustion cycle of the internal combustion engine;
An energization time setting means (42) for setting an energization time to the electric actuator based on the adaptation value stored in the storage means;
Detection means (52) for detecting the behavior of the valve body;
Learning means (44) for learning the detection result of the detection means as correction data used for correcting the adaptation value;
Correction means (46) for correcting the fitness value based on the correction data learned by the learning means;
With
The energization time of the electric actuator is a time of a predetermined range (Wa) of partial lift injection that starts the valve closing operation before reaching the maximum valve opening position after the valve body starts the valve opening operation. If there is, a fuel injection control device that performs learning by the learning means. The fuel injection valve has elastic means (15) for applying an elastic force to the valve body to perform a valve closing operation,
Based on the correction data learned by the learning means, comprising characteristic estimation means (45) for estimating the characteristics of the elastic means,
The fuel injection control device according to claim 1, wherein the correction unit sets a correction amount for the adaptive value based on an estimation result by the characteristic estimation unit. In the case where the time shorter than the first predetermined time is referred to as the first region (W1) among the regions of the energization time for performing the partial lift injection,
The fuel injection control device according to claim 1, wherein the predetermined range is set to a range excluding the first region. Among the energization time areas in which the partial lift injection is performed, when a time longer than a second predetermined time is referred to as a second area (W2),
The fuel injection control device according to any one of claims 1 to 3, wherein the predetermined range is set to a range excluding the second region. The storage means distinguishes and stores the adaptive value for each supply fuel pressure, which is the pressure of fuel supplied to the fuel injection valve,
The energization time setting means sets the energization time based on the adaptive value according to the supply fuel pressure at the time of fuel injection,
5. The fuel injection control device according to claim 1, wherein the learning unit discriminates and learns the correction data for each supply fuel pressure detected by the detection unit. 6. .

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