JP5360092B2 - Fuel injection control device - Google Patents

Abstract

The system has pressure sensor (20) to detect change in fuel pressure due to fuel injection by fuel injector (10). A control unit (30) computes fuel injection rate parameter based on fuel pressure waveform for controlling fuel injector operation. The control unit has learning portion to memorize and update fuel injection rate parameter in controller memory in association with fuel injection amount and pressure. A transfer section transfers fuel injection rate parameter memorized in controller memory to injector memory (23a), when internal combustion engine is turned off.

Description

  The present invention relates to a fuel injection control device applied to a fuel injection system that controls the operation of a fuel injection valve based on a change in fuel pressure caused by fuel injection.

  In Patent Documents 1 to 4 and the like, a pressure change (fuel pressure waveform) caused by fuel injection is detected by detecting the pressure of the fuel supplied to the fuel injection valve with a fuel pressure sensor, and corresponds to the fuel pressure waveform. An invention for calculating an injection rate parameter required for specifying an injection rate waveform is disclosed. For example, paying attention to a high correlation between the fuel pressure waveform drop start timing and the injection start timing caused by the start of injection, the response delay time te (injection rate parameter) from the start of injection to the injection start timing is set. The calculation is based on the descent start time appearing in the fuel pressure waveform.

JP 2009-57926 A JP 2009-74535 A JP 2009-74536 A JP 2010-285888 A

  Patent Documents 1 to 4 describe that an injector side memory is mounted on the fuel injection valve separately from a control side memory mounted on an ECU (control device) that controls the operation of the fuel injection valve. However, the present inventor has studied to configure as follows using such an injection valve side memory.

  That is, during the operation period of the internal combustion engine, the injection rate parameter calculated from the fuel pressure waveform is stored and updated sequentially in the control-side memory, and learning is performed, and the operation of the fuel injection valve is controlled (injection control) based on the learned value. At the end of the operation of the internal combustion engine, the injection rate parameter stored in the control side memory is transmitted to the injection valve side memory for storage. When starting the internal combustion engine next time, the injection rate parameter stored in the injection valve side memory is transmitted to the control side memory.

  According to this configuration, even when the fuel injection valve is replaced with another fuel injection valve, the injection rate parameter stored in the replaced injection valve side memory is the control side memory at the start of operation of the internal combustion engine. Therefore, injection control can be performed based on the injection rate parameter applied to the fuel injection valve after replacement.

  However, depending on the environmental value at the time of injection (for example, the fuel pressure and the injection amount at the time of starting fuel injection), even the same injection command signal results in different injection states. Therefore, it is necessary to learn the injection rate parameter in association with each environmental value. Then, since the number of data points of the injection rate parameter becomes enormous, the storage capacity required for the injection valve side memory increases, and the transmission time when the injection rate parameter is transmitted from the ECU to the injection valve side memory becomes longer. Problems arise.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a fuel injection control capable of reducing the storage capacity required for the injection valve side memory and shortening the transmission time of the injection rate parameter. To provide an apparatus.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  According to the first aspect of the present invention, a fuel injection valve that injects fuel used for combustion of an internal combustion engine, and a fuel pressure sensor that detects a fuel pressure waveform that represents a change in the pressure of the fuel caused by fuel injection from the fuel injection valve. And calculating an injection rate parameter required to specify an injection rate waveform corresponding to the detected fuel pressure waveform, and controlling the operation of the fuel injection valve based on the calculated injection rate parameter. It is assumed that the present invention is applied to a fuel injection system including a control device, a control side memory mounted on the control device, and an injection valve side memory mounted on the fuel injection valve.

Then, the control device associates the calculated injection rate parameter with an environmental value that affects the fuel injection state and updates the memory in the control-side memory, and more than the entire range of the environmental value. Update range setting means for setting a predetermined update range that is a small range, and at the end of operation of the internal combustion engine, among the injection rate parameters stored in the control-side memory, the update range setting means is associated with the environmental value of the update range Transmitting means for transmitting the injection rate parameter to the injection valve side memory, and the control device calculates a plurality of types of the injection rate parameters based on the detected one fuel pressure waveform, and the learning means Is configured to store and update a plurality of types of the injection rate parameters in the control-side memory in association with the environmental value, and the update range setting means In setting the update range for each Iritsu parameter, and sets the range in common with the update range of each.

  According to the above invention, at the end of the operation of the internal combustion engine, the injection rate parameter of the control side memory is transmitted to the injection valve side memory, so even if the fuel injection valve is replaced with another fuel injection valve, If the injection rate parameter stored in the injection valve side memory is transmitted to the control side memory, the operation of the fuel injection valve can be controlled (injection control) based on the injection rate parameter applied to the fuel injection valve after replacement. .

  Then, a predetermined update range that is smaller than the entire range of the environmental value is set, and an injection rate parameter corresponding to the update range (that is, a part of all the injection rate parameters) is transferred from the control device to the injection valve side. Since the data is transmitted to the memory, the storage capacity required for the injection valve side memory can be reduced compared with the case where all injection rate parameters stored in the control side memory are transmitted, and the injection device side memory can be reduced. The transmission time of the injection rate parameter can be shortened.

According to the above invention, when the fuel injection valve is not replaced, the internal combustion engine is started next time with the injection rate parameter transmitted to the injection valve side memory at the end of the previous operation as the initial value. It becomes. In this case, it is advantageous in terms of improving the accuracy of the injection control that all the injection rate parameters are transmitted to the injection valve side memory and set to the initial value. However, among the injection rate parameters, there are also injection rate parameters that do not greatly contribute to improving the accuracy of injection control even if they are updated as initial values for the next operation. Therefore, in the above invention, if the update range is set so as to exclude such an injection rate parameter, deterioration in the accuracy of injection control can be minimized.
Here, the present inventor has obtained the knowledge that the non-uniformity of the storage update amount and the non-uniformity of the learning frequency caused by the range of the environmental value are almost common even if the types of the injection rate parameters are different. In other words, the range of the environmental value with a large stored update amount and the range of the environmental value with a red learning frequency are almost common even if the types of injection rate parameters are different. In the above invention in view of this point, since a common update range is set for each of a plurality of types of injection rate parameters, the following effects are exhibited.
That is, when an update range is set based on the learning state of one type of injection rate parameter, if the injection rate parameter is mislearned, an update range that minimizes deterioration in accuracy of injection control is appropriately set. Cannot be set. On the other hand, according to the above invention in which a common update range is set for each of the plurality of types of injection rate parameters, the update range can be set based on the learning state of the plurality of types of injection rate parameters. Can be set with high accuracy.

  According to a second aspect of the present invention, the update range setting means has a higher injection rate parameter that has a larger storage update amount by the learning means among the injection rate parameters corresponding to the environmental value. The environment value range corresponding to the parameter is preferentially included in the update range.

  It can be said that the injection rate parameter having a small stored update amount (or not stored updated) is the above-described parameter “does not greatly contribute to improving the accuracy of the injection control even if it is updated as the initial value of the next operation”. According to the above-mentioned invention in view of this point, the injection rate parameter with the larger storage update amount is preferentially transmitted to the injection valve side memory, and is updated as the initial value of the next operation. Accordingly, it is possible to minimize deterioration in the accuracy of the injection control due to not transmitting all the injection rate parameters to the injection valve side memory.

  According to a third aspect of the present invention, the control-side memory stores a reference value of the injection rate parameter corresponding to each of the environmental values, and the stored update amount is the injection rate at the end of the operation. It is a difference between a parameter value and the reference value.

  Here, the phenomenon that the injection rate parameter is greatly deviated from the reference value due to aging deterioration of the fuel injection valve and machine difference variation does not occur at the same level in all injection rate parameters, but the environmental value Depending on the range, there is unevenness. According to the above-described invention focusing on this point, the range of the injection rate parameter in which the difference between the injection rate parameter at the end of the operation and the reference value is large is preferentially set to be included in the update range, and the injection Since the rate parameter is transmitted to the injection valve side memory, the above-described deterioration in accuracy of the injection control can be minimized.

  In the invention of claim 4, the value of the injection rate parameter corresponding to each of the environmental values, the value at the end of the previous operation of the internal combustion engine being the previous value, the value at the end of the current operation Is the current value, the control-side memory stores the previous value, and the storage update amount is a difference between the current value and the previous value.

  Here, the phenomenon that the current value of the injection rate parameter is greatly deviated from the previous value due to aging deterioration of the fuel injection valve, etc. does not occur in all injection rate parameters at the same level, but the environmental value Depending on the range, there is unevenness. According to the above-described invention focusing on this point, the range of the injection rate parameter in which the difference between the current value and the previous value of the injection rate parameter at the end of operation is large is preferentially set to be included in the update range. Thus, since the injection rate parameter is transmitted to the injection valve side memory, the deterioration of the accuracy of the injection control described above can be minimized.

  In the invention according to claim 5, the update range setting unit is configured to update the update range based on a frequency (learning frequency) at which each of the injection rate parameters corresponding to the environmental value is updated by the learning unit. Is set.

  In the above invention, if the update range is set so that the injection rate parameter having a high learning frequency is preferentially transmitted to the injection valve side memory, the following effects are exhibited. That is, since the injection rate parameter having a high learning frequency is highly likely to be used for injection control during the next operation, priority is given to the injection rate parameter having a high learning frequency and high availability for injection control. If it is transmitted to the injection valve side memory, the accuracy of the injection control can be improved.

  Moreover, in the said invention, if the update range is set so that the injection rate parameter with low learning frequency may be preferentially transmitted to the injection valve side memory, the following effects are exhibited. In other words, since the injection rate parameter having a low learning frequency is likely to have less learning opportunities during the next operation, the injection rate parameter having a low learning frequency and a low learning opportunity is given priority to the injection valve side memory. If it transmits, the precision of injection control can be improved.

According to a sixth aspect of the present invention, one of the environmental values is a pressure immediately before the fuel pressure waveform starts to decrease with the start of fuel injection from the fuel injection valve, and the other is a fuel from the fuel injection valve. And the learning means stores and updates the injection rate parameter in association with the immediately preceding pressure and the injection amount.

  Specific examples of environmental values include the temperature of the fuel, the interval time from the end of the previous stage injection to the start of the current injection, in addition to the pressure and the injection quantity immediately before, but the previous pressure and the injection quantity are in the injection state. The effect is large compared to other environmental values. Therefore, according to the above-described invention in which the injection rate parameter is stored and updated in association with the immediately preceding pressure and the injection amount, the accuracy of the control can be improved when performing the injection control based on the learned injection rate parameter.

  In the above invention, since the injection rate parameter is learned in association with the two environmental values, the number of learning points for the injection rate parameter becomes enormous. Therefore, if it is attempted to transmit all the injection rate parameters to the injection valve side memory, contrary to the above-described invention, the storage capacity required for the injection valve side memory and the transmission time of the injection rate parameter become enormous. Therefore, the effect of the said invention by transmitting a part of injection rate parameter to the injection valve side memory is exhibited suitably.

  By the way, in addition to the above-described invention, the present inventor designates a fuel injection control device that can reduce the storage capacity required for the injection valve side memory and shorten the transmission time of the injection rate parameter as “other invention”. In the following, the configuration and effects of other inventions will be described.

  In [Other invention 1], a fuel injection valve that injects fuel used for combustion of an internal combustion engine, a fuel pressure sensor that detects a fuel pressure waveform that represents a change in fuel pressure caused by fuel injection from the fuel injection valve, and And a control for calculating an injection rate parameter required for specifying an injection rate waveform corresponding to the detected fuel pressure waveform based on the detected fuel pressure waveform and controlling an operation of the fuel injection valve based on the calculated injection rate parameter It is assumed that the present invention is applied to a fuel injection system including an apparatus, a control side memory mounted on the control device, and an injection valve side memory mounted on the fuel injection valve.

  And the said control apparatus is provided with the learning means demonstrated below, a change pattern discrimination means, a variation | change_quantity calculation means, and a transmission means, It is characterized by the above-mentioned. The learning means stores and updates the calculated injection rate parameter in the control-side memory in association with an environmental value that affects the fuel injection state. The change pattern discrimination means discriminates in which of a plurality of change patterns assumed in advance the learning value of the injection rate parameter changes in the entire range of environmental values. The change amount calculating means calculates a storage update amount of an injection rate parameter corresponding to a predetermined environmental value. The transmission means transmits change pattern information indicating a determination result by the change pattern determination means and change amount information indicating a calculation result by the change amount calculation means to the injection valve side memory.

  Here, the injection rate parameter tends to continue to increase or decrease as a whole in the entire range of environmental values (see FIGS. 8B to 8E). In other words, the change pattern of the injection rate parameter is determined to some extent, and every time the internal combustion engine finishes operation, if you know which pattern is changing and the amount of change, the injection rate parameter over the entire range of environmental values Can be estimated.

  In the other invention 1 in view of this point, since the change pattern information and the change amount information are transmitted to the injection valve side memory, the injection rate parameter stored in the injection valve side memory is controlled at the start of the next operation of the internal combustion engine. The above estimation can be realized by transmitting to the side memory. Therefore, even if the fuel injection valve is replaced with another fuel injection valve, if the change pattern information and the change amount information stored in the replaced injection valve side memory are transmitted to the control side memory, It is possible to estimate the value of the injection rate parameter in the entire environmental value range for the fuel injection valve, and to control (injection control) the operation of the fuel injection valve based on the estimated value.

  And according to the said other invention 1, since change pattern information and change amount information are transmitted to the injection valve side memory, compared with the case where all the injection rate parameters memorize | stored in the control side memory are transmitted, the injection valve The storage capacity required for the side memory can be reduced, and the transmission time of the injection rate parameter from the control device to the injection valve side memory can be shortened.

[Other invention 2] states, “The control-side memory stores a reference value of the injection rate parameter corresponding to each of the environmental values,
The fuel injection control apparatus according to another aspect 1, wherein the change pattern determination unit performs the determination based on a change in the injection rate parameter with respect to the reference value at the end of the operation.

  Since the tendency (pattern) of change with respect to the reference value of the injection rate parameter due to aging deterioration of the fuel injection valve and machine difference variation is determined to some extent, the change pattern is determined based on the change with respect to the reference value of the injection rate parameter at the end of operation. According to the above invention, the change pattern can be discriminated with high accuracy, and the deterioration in accuracy of the injection control described above can be minimized.

[Other invention 3] is “the value of the injection rate parameter corresponding to each of the environmental values, the value at the end of the previous operation of the internal combustion engine being the previous value, the value at the end of the current operation”. Is the current value,
2. The fuel injection control according to claim 1, wherein the control-side memory stores the previous value, and the change pattern determination means performs the determination based on a change of the current value with respect to the previous value. Device ".

  Since the tendency (pattern) of the change in the injection rate parameter with respect to the previous value due to aging deterioration of the fuel injection valve is determined to some extent, the change pattern is determined based on the change in the current injection rate parameter with respect to the previous value. The change pattern can be discriminated with high accuracy, and the deterioration of the accuracy of the injection control described above can be minimized.

[Other invention 4] states, “One of the environmental values is a pressure immediately before the fuel pressure waveform starts to decrease with the start of fuel injection from the fuel injection valve, and the other is a fuel from the fuel injection valve. Injection amount of
In the fuel injection control device according to any one of the first to third aspects of the invention, the learning unit stores and updates the injection rate parameter in association with the immediately preceding pressure and the injection amount. is there. According to this, the same effect as that of the seventh aspect of the invention can be exhibited.

It is a figure showing the outline of the fuel injection system to which the fuel injection control device concerning a 1st embodiment of the present invention is applied. It is a figure which shows the change of the injection rate and fuel pressure corresponding to an injection command signal. In a 1st embodiment, it is a block diagram showing an outline of learning of an injection rate parameter, setting of an injection command signal, etc. It is a block diagram of the fuel-injection system shown in FIG. 6 is a flowchart illustrating a procedure for transmitting ECU data to an INJ-side memory in the first embodiment and the second embodiment. 4 is a flowchart illustrating a procedure for transmitting data in an INJ side memory to an ECU in the first embodiment. In 3rd Embodiment of this invention, it is a flowchart which shows the procedure which transmits the data of ECU to the INJ side memory. In 4th Embodiment of this invention, it is a figure which shows a mode that the real Tq-Q characteristic line has shifted | deviated from the master Tq-Q characteristic line. In 4th Embodiment, it is a flowchart which shows the procedure which transmits the data of ECU to the INJ side memory. In 4th Embodiment, it is a flowchart which shows the procedure which transmits the data of the INJ side memory to ECU.

  Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. The fuel injection control apparatus described below is mounted on a vehicle engine (internal combustion engine). The engine is injected with high-pressure fuel for a plurality of cylinders # 1 to # 4 and compressed by itself. A diesel engine that ignites and burns is assumed.

(First embodiment)
FIG. 1 shows a fuel injection system including a fuel injection valve 10 mounted on each cylinder of the engine, a fuel pressure sensor 20 mounted on each fuel injection valve 10, and an ECU 30 as an electronic control device mounted on a vehicle. FIG.

  First, the fuel injection system of the engine including the fuel injection valve 10 will be described. The fuel in the fuel tank 40 is pumped and stored in the common rail 42 (pressure accumulating container) by the high pressure pump 41, and is distributed and supplied to the fuel injection valve 10 of each cylinder.

  The fuel injection valve 10 includes a body 11, a needle 12 (valve element), an actuator 13, and the like described below. The body 11 forms a high-pressure passage 11a inside and a nozzle hole 11b for injecting fuel. The needle 12 is accommodated in the body 11 and opens and closes the nozzle hole 11b. The actuator 13 opens and closes the needle 12.

  The opening / closing operation of the needle 12 is controlled by the ECU 30 controlling the driving of the actuator 13. Thereby, the high-pressure fuel supplied from the common rail 42 to the high-pressure passage 11 a is injected from the injection hole 11 b according to the opening / closing operation of the needle 12. For example, the ECU 30 calculates a target injection state such as an injection start timing, an injection end timing, and an injection amount based on the rotation speed of the engine output shaft, the engine load, and the like, and sends an injection command signal to the actuator 13 so that the calculated target injection state is obtained. Is output to control the operation of the fuel injection valve 10.

  The fuel pressure sensor 20 is mounted on each fuel injection valve 10 and includes a stem 21 (a strain generating body), a pressure sensor element 22, a mold IC 23, and the like described below. The stem 21 is attached to the body 11, and the diaphragm portion 21a formed on the stem 21 is elastically deformed by receiving the pressure of the high-pressure fuel flowing through the high-pressure passage 11a. The pressure sensor element 22 is attached to the diaphragm portion 21a, and outputs a pressure detection signal in accordance with the amount of elastic deformation generated in the diaphragm portion 21a.

  The mold IC 23 is formed by resin molding electronic components such as an amplification circuit that amplifies the pressure detection signal output from the pressure sensor element 22 and a rewritable nonvolatile memory INJ side memory 23a (injection valve side memory). It is mounted on the fuel injection valve 10 together with the stem 21. A connector 14 is provided on the upper portion of the body 11, and the mold IC 23, the actuator 13, and the ECU 30 are electrically connected by a harness 15 connected to the connector 14.

  The ECU 30 calculates a target injection state (for example, the number of injection stages, the injection start timing, the injection end timing, the injection amount, etc.) based on the operation amount of the accelerator pedal, the engine load, the engine rotational speed NE, and the like. For example, the optimal injection state corresponding to the engine load and the engine speed is stored as an injection state map. Based on the current engine load and engine speed, the target injection state is calculated with reference to the injection state map. Then, the injection command signals t1, Tq (see FIG. 2A) corresponding to the calculated target injection state are set based on the injection rate parameters td, te, Rα, Rβ, Rmax, which will be described in detail later, and the fuel injection valve The operation of the fuel injection valve 10 is controlled by outputting to 10.

  Further, based on the detected value of the fuel pressure sensor 20, a change in the fuel pressure caused by the injection is detected as a fuel pressure waveform (see FIG. 2C), and an injection representing a change in the fuel injection rate based on the detected fuel pressure waveform. The rate waveform (see FIG. 2B) is calculated to detect the injection state. Then, the injection rate parameters Rα, Rβ, and Rmax that specify the detected injection rate waveform (injection state) are learned, and the injection that specifies the correlation between the injection command signal (pulse-on timing t1 and pulse-on period Tq) and the injection state The rate parameters td and te are learned.

  Specifically, in the fuel pressure waveform, a descending approximation line that approximates a descending waveform from the inflection point P1 at which the fuel pressure drop starts at the start of injection to the inflection point P2 at which the descent ends by a least square method or the like. Lα is calculated. Then, a time (a crossing time LBα between Lα and Bα) that is the reference value Bα in the descending approximate straight line Lα is calculated. Focusing on the fact that the intersection time LBα and the injection start time R1 are highly correlated, the injection start time R1 is calculated based on the intersection time LBα. For example, a timing that is a predetermined delay time Cα before the intersection timing LBα may be calculated as the injection start timing R1.

  In addition, a rising approximation line Lβ is calculated by approximating the rising waveform from the inflection point P3 where the fuel pressure rises at the end of injection to the inflection point P5 where the descent ends from the fuel pressure waveform by a least square method or the like. To do. Then, a time (intersection time LBβ between Lβ and Bβ) that is the reference value Bβ in the rising approximate straight line Lβ is calculated. Focusing on the fact that the intersection timing LBβ and the injection end timing R4 are highly correlated, the injection end timing R4 is calculated based on the intersection timing LBβ. For example, a timing that is a predetermined delay time Cβ before the intersection timing LBβ may be calculated as the injection end timing R4.

  Next, paying attention to the fact that the slope of the descending approximate line Lα and the slope of the injection rate increase are highly correlated, the slope of the straight line Rα indicating the increase in the injection rate waveform shown in FIG. Calculation is based on the slope of Lα. For example, the slope of Rα may be calculated by multiplying the slope of Lα by a predetermined coefficient. Similarly, since the slope of the rising approximate line Lβ and the slope of the injection rate decrease are highly correlated, the slope of the straight line Rβ indicating the decrease in injection in the injection rate waveform is calculated based on the slope of the rising approximate line Lβ.

  Next, based on the straight lines Rα and Rβ of the injection rate waveform, a timing (valve closing operation start timing R23) at which the valve body 12 starts lift-down in response to the command to end injection is calculated. Specifically, the intersection of both straight lines Rα and Rβ is calculated, and the intersection timing is calculated as the valve closing operation start timing R23. Further, a delay time (injection start delay time td) with respect to the injection start command timing t1 of the injection start timing R1 is calculated. Further, a delay time (injection end delay time te) with respect to the injection end command timing t2 of the valve closing operation start timing R23 is calculated.

  Further, the pressure corresponding to the intersection of the descending approximate straight line Lα and the ascending approximate straight line Lβ is calculated as the intersection pressure Pαβ, and a pressure difference ΔPγ between the reference pressure Pbase and the intersection pressure Pαβ, which will be described in detail later, is calculated. Focusing on the fact that the correlation with the maximum injection rate Rmax is high, the maximum injection rate Rmax is calculated based on the pressure difference ΔPγ. Specifically, the maximum injection rate Rmax is calculated by multiplying the pressure difference ΔPγ by the correlation coefficient Cγ. However, in the case of the small injection in which the pressure difference ΔPγ is less than the predetermined value ΔPγth, Rmax = ΔPγ × Cγ is set as described above, while in the case of the large injection in which ΔPγ ≧ ΔPγth, it is set in advance. The value (set value Rγ) is calculated as the maximum injection rate Rmax.

  The reference pressure Pbase may be an average pressure of the reference waveform based on a reference waveform that is a portion of the fuel pressure waveform corresponding to a period until the fuel pressure starts decreasing with the start of injection. For example, what is necessary is just to set the part corresponding to the period TA until predetermined time passes from the injection start command timing t1 as a reference waveform. Alternatively, the inflection point P1 may be calculated based on the differential value of the descending waveform, and a portion corresponding to a period from the injection start command timing t1 to a predetermined time before the inflection point P1 may be set as the reference waveform.

  Note that the “small injection” is assumed to be an injection in which the valve body 12 starts to be lifted down before the injection rate reaches Rγ, and the fuel is throttled at the seat surfaces 11e and 12a to thereby reduce the injection amount. The injection rate when it is restricted becomes the maximum injection rate Rmax. On the other hand, the “large injection” is assumed to be an injection in which the valve body 12 starts to lift down after the injection rate reaches Rγ, and the injection amount is limited by the fuel being throttled at the injection hole 11b. The injection rate when the engine is running is the maximum injection rate Rmax. In short, when the injection command period Tq is sufficiently long and the valve opening state is continued even after reaching the maximum injection rate, the injection rate waveform shown in FIG. On the other hand, in the case of small injection that starts the valve closing operation before reaching the maximum injection rate, the injection rate waveform is a triangle.

  The set value Rγ which is the maximum injection rate Rmax at the time of large injection changes as the fuel injection valve 10 changes over time. For example, when aged deterioration such as deposits or the like deposits on the nozzle holes 11b and the injection amount decreases, the pressure drop amount ΔP shown in FIG. 2C decreases. Further, as the seat surface 11e, 12a wears and the aging deterioration such that the injection amount increases, the pressure drop amount ΔP increases. Note that the pressure drop amount ΔP is the amount of decrease in the detected pressure caused by the increase in the injection rate. For example, the pressure drop amount from the reference pressure Pbase to the inflection point P2 or the change from the inflection point P1. It is the amount of pressure drop to the bend point P2.

  Therefore, in the present embodiment, focusing on the fact that the maximum injection rate Rmax (set value Rγ) and the pressure drop amount ΔP during large injection are highly correlated, learning is performed by calculating the set value Rγ from the detection result of the pressure drop amount ΔP. To do. That is, the learned value of the maximum injection rate Rmax at the time of large injection corresponds to the learned value of the set value Rγ based on the pressure drop amount ΔP.

  As described above, the injection rate parameters td, te, Rα, Rβ, and Rmax can be calculated from the fuel pressure waveform. Based on the learned values of the injection rate parameters td, te, Rα, Rβ, and Rmax, an injection rate waveform (see FIG. 2B) corresponding to the injection command signal (see FIG. 2A) is calculated. be able to.

  Since the area of the injection rate waveform calculated in this way (see halftone dot hatching in FIG. 2B) corresponds to the injection amount, the injection amount can also be calculated based on the injection rate parameter. Then, the ratio of the injection amount with respect to the injection command period Tq may be learned as an injection rate parameter.

  FIG. 3 is a block diagram showing an outline of learning of these injection rate parameters, setting of an injection command signal, and the like. Each means 31, 32, 33 functioning by the ECU 30 will be described below. The injection rate parameter calculation means 31 calculates injection rate parameters td, te, Rα, Rβ, Rmax based on the fuel pressure waveform detected by the fuel pressure sensor 20.

  The learning means 32 learns by updating the calculated injection rate parameter in the RAM 34c (see FIG. 4) of the ECU 30. Note that the injection rate parameter varies depending on the supply fuel pressure (pressure in the common rail 42) each time the fuel is injected, and is therefore learned in association with the supply fuel pressure or a reference pressure Pbase (see FIG. 2C) described later. It is desirable. Further, since the injection rate parameter has a different value depending on the injection amount Q (halftone hatch area in FIG. 2B) every time it is injected, it is desirable to learn in association with the injection amount Q.

  In the example of FIG. 3, two fuel pressures such as the reference pressure Pbase and the injection amount Q are set as environmental values, and the values of the injection rate parameters are associated with these environmental values Pbase, Q and the injection rate parameter maps M1 to M1. It is stored in M5. Each of the maps M1 to M5 is created corresponding to five injection rate parameters td, te, Rα, Rβ, and Rmax.

  In the maps M1 to M5 shown in FIG. 3, the reference pressure is divided into m pieces and the injection amount Q is divided into n pieces, and the maps M1 to M5 are divided into m × n areas (m and n are 2 or more). Natural number). The learning values or initial values of the injection rate parameters td, te, Rα, Rβ, Rmax corresponding to each region are stored. In all the maps M1 to M5, each region is divided by the same number of divisions with m reference pressures and n injection amounts Q. Further, the reference pressure and the injection amount Q in each region are set to the same value in each of the maps M1 to M5.

  The setting means 33 (control means) acquires the current fuel pressure (for example, the previous value of the reference pressure Pbase) and the injection rate parameter (learned value) corresponding to the target injection amount from the injection rate parameter maps M1 to M5. And based on the acquired injection rate parameter, the injection command signals t1 and Tq corresponding to the target injection state are set. The fuel pressure sensor 20 detects the fuel pressure waveform when the fuel injection valve 10 is operated in accordance with the injection command signal set in this way, and the injection rate parameter calculation means 31 based on the detected fuel pressure waveform, the injection rate parameter td, te, Rα, Rβ, Rmax are calculated.

  In short, an actual injection state (that is, injection rate parameters td, te, Rα, Rβ, Rmax) with respect to the injection command signal is detected and learned, and an injection command signal corresponding to the target injection state is set based on the learned value. . Therefore, the injection command signal is feedback-controlled based on the actual injection state, and the fuel injection state can be controlled with high accuracy so that the actual injection state coincides with the target injection state even when the above-described aging deterioration proceeds. In particular, feedback control is performed so as to set the injection command period Tq based on the injection rate parameter so that the actual injection amount becomes the target injection amount, so that the actual injection amount is compensated to become the target injection amount.

  As shown in FIG. 4, the ECU 30 includes a microcomputer (microcomputer 34), an ECU-side memory 35 that is a writable nonvolatile memory, and a communication circuit 36 that functions as a communication interface. The microcomputer 34 includes a CPU 34a, a non-writable nonvolatile memory (ROM 34b), a writable volatile memory (RAM 34c), and the like. The ECU side memory 35 and the RAM 34c correspond to a control side memory.

  The initial value of learning by the learning means 32 described above is acquired in advance by a test before shipping the fuel injection valve 10 to the market, and the acquired initial value is the fuel injection valve when the fuel injection valve 10 is shipped to the market. 10 INJ side memory 23 a and ECU side memory 35. A specific example of the ECU-side memory 35 and the INJ-side memory 23a is EEPROM (registered trademark).

  The initial value is a value in consideration of machine difference variation for each of a plurality of different fuel injection valves 10, and is a value unique to the corresponding fuel injection valve 10. On the other hand, a master value (reference value), which is an eigenvalue of the master fuel injection valve serving as a reference and serves as a reference for determining the machine difference variation, is written in the ECU-side memory 35 separately from the initial value.

  During engine operation, the values of the injection rate parameters learned by the learning unit 32 as described above (learned values of the maps M1 to M5) are temporarily stored in the RAM 34c of the microcomputer 34, and the engine operation end point ( For example, when the ignition switch is turned off, the ECU side memory 35 is written and stored. Then, at the start of engine operation (for example, when the ignition switch is turned on), the learned values of the maps M1 to M5 stored in the ECU-side memory 35 are read into the RAM 34c.

  The communication circuit 36 is connected to the INJ-side memory 23a so as to be capable of bidirectional communication. At the end of engine operation, one of the learning values in the maps M1 to M5 stored in the ECU-side memory 35 or the RAM 34c. Are transmitted to the INJ-side memory 23a and written. Further, at the start of engine operation, a part of the learning value stored in the INJ side memory 23 a is read into the ECU side memory 35. That is, at the start of engine operation, a part of the maps M1 to M5 stored in the ECU-side memory 35 is rewritten to the value in the INJ-side memory 23a.

  FIG. 5 is a flowchart illustrating a procedure executed by the microcomputer 34 of the ECU 30 and a procedure for transmitting data of the ECU 30 to the INJ side memory 23a.

  First, in step S10, based on whether or not the driver has turned off the ignition switch, it is determined whether or not it is the end of engine operation. If it is determined that the engine operation has ended (S10: YES), in the subsequent step S11, the master value (reference value) corresponding to each of the m × n areas of the maps M1 to M5 and the learning in the maps M1 to M5. The difference (stored update amount) from the value is calculated for each map M1 to M5 and for each region.

  In the subsequent step S12, a plurality of areas having a large difference are selected from all the areas of the maps M1 to M5, and the selected range (hereinafter referred to as a large difference range W1 to W5) is selected for each map M1 to M5. calculate. As a result, a range that is smaller than that is selected from the entire map region that is the entire range of environmental values. The method for setting the selected range is, for example, by setting a predetermined number smaller than m × n in advance, and including a range including the predetermined number of regions in descending order of the difference. Set as W5. In the example of FIG. 4, the range indicated by the halftone dot indicates the large difference range W1 with respect to the map M1, and the large difference ranges W1 to W5 may be a set of a plurality of adjacent areas as illustrated in FIG. It may be a set of distant areas.

  Then, the selected range is set as a predetermined update range. Specifically, in the subsequent step S13 (update range setting means), an update range W that is a range common to all the maps M1 to M5 is set based on the large difference ranges W1 to W5 for the maps M1 to M5. For example, the update large range W1 to W5 is averaged to set the update range W (see the hatched range in FIG. 4). More specifically, the center positions of the large difference ranges W1 to W5 of the maps M1 to M5 are calculated, and a predetermined number centering on the average of the center positions of the maps M1 to M5 (9 in the example of FIG. 4). ) Is set as the update range W.

  Incidentally, the large difference ranges W1 to W5 calculated in this way tend to become almost common ranges in the maps M1 to M5. That is, the range of the region in which the difference between the learning values becomes large between the engine operation start time and the end time tends to be a common range for a plurality of types of injection rate parameters td, te, Rα, Rβ, and Rmax.

  In the subsequent step S14 (transmission means), a plurality of injection rate parameters td, te, Rα, Rβ, Rmax corresponding to the update range W for each of the maps M1 to M5 (9 in the example of FIG. 4 × 5 maps). (Learning value) is transmitted to the INJ side memory 23a and stored. The injection rate parameter corresponding to the area other than the update range W is not transmitted to the INJ side memory 23a.

  Therefore, the injection rate parameter maps M1a to M5a stored in the INJ side memory 23a store the injection rate parameters corresponding to the update range W, and do not store the injection rate parameters corresponding to other ranges. . Note that all previous values stored in the INJ side memory 23a are deleted, and the current injection rate parameter is stored in the INJ side memory 23a.

  As described above, by executing the processing of FIG. 5, a part of the learning value at the end of the engine operation, that is, the learning value corresponding to the update range W among the learning values of all regions is transmitted to the INJ side memory 23a. Is remembered.

  FIG. 6 is a flowchart showing a process executed by the microcomputer 34 of the ECU 30 and a procedure for transmitting data in the INJ-side memory 23a to the ECU 30.

  First, in step S20, it is determined whether or not it is the time to start the engine operation based on whether or not the driver has turned on the ignition switch. If it is determined that the engine operation has started (S20: YES), in the subsequent step S21, all injection rate parameters in the maps M1a to M5a stored in the INJ side memory 23a, that is, stored at the end of the previous engine operation. All the injection rate parameter values corresponding to the updated range W are read.

  In the subsequent step S22, among the injection rate parameters (learned values) in the maps M1 to M5 stored in the ECU side memory 35, the injection rate parameter corresponding to the update range W read from the INJ side memory 23a is set on the INJ side. The value read from the memory 23a is rewritten.

  6 is executed, a part of the learning value stored in the INJ side memory 23a at the end of the previous engine operation is read at the start of the engine operation this time, Data in the maps M1 to M5 is rewritten.

  By the way, when the fuel injection valve 10 is replaced after the engine is shipped to the market, the data (injection rate parameter) of the maps M1 to M5 in the ECU-side memory 35 is adapted to the fuel injection valve 10 after replacement. Need to be rewritten. Similarly, when the ECU 30 is replaced after shipment on the market, it is necessary to rewrite the replaced ECU-side memory 35 with data suitable for the actually mounted fuel injection valve 10.

  In the present embodiment, even when such replacement is performed, the data in the INJ side memory 23a is read and the data in the maps M1 to M5 in the ECU side memory 35 is rewritten at the start of engine operation. Therefore, even when the above-described replacement is performed, the maps M1 to M5 based on the injection rate parameters suitable for the fuel injection valve 10 that is actually mounted can be created at the start of engine operation. . Therefore, even when learning by the learning means 32 immediately after the start of engine operation is in the initial stage, the setting means 33 can set the injection command signal based on the highly accurate injection rate parameter, and the accuracy of injection control can be improved. .

  Since a part of the data of the maps M1 to M5 is transmitted and stored in the INJ side memory 23a, the storage capacity required for the INJ side memory 23a can be reduced as compared with the case of transmitting all the data, and Data transmission time from the ECU 30 to the INJ side memory 23a can be shortened.

  Here, contrary to the present embodiment, it is advantageous in terms of improving the injection accuracy at the initial stage of learning described above that all the data is transmitted to the INJ side memory 23a and stored. However, among the injection rate parameters, there are also injection rate parameters (non-important data) that do not greatly contribute to improving the accuracy of injection control even if they are updated as initial values for the next operation.

  In this embodiment in view of this point, an injection rate parameter corresponding to a region where the difference between the master value and the learned value is large is regarded as important data, and the important data (that is, the injection rate parameter corresponding to the update range W) is INJ. Since the data is transmitted and stored in the side memory 23a, the deterioration in the accuracy of the injection control compared to the case where all the data is transmitted to the INJ side memory 23a can be minimized.

(Second Embodiment)
In the present embodiment, step S11 of FIG. 5 according to the first embodiment is changed to step S11a indicated by a one-dot chain line in FIG. In the first embodiment, the difference between the learning value and the master value is calculated for each region (S11), and the update range W is set based on the range of the region where the difference is large (difference large range W1) (S12). , S13).

  On the other hand, in the present embodiment, when the learning value at the end of the previous operation of the engine is the previous value and the learning value at the end of the current operation is the current value, the previous value for the entire region is stored in the ECU-side memory 35. In step S11a, the difference (stored update amount) between the previous value and the current value stored in the ECU-side memory 35 is calculated for each region. Then, based on the range of the region where the difference is large (difference large range W1), the update range W is set in the same manner as in the first embodiment (S12, S13).

  As described above, the present embodiment also exhibits the same effects as those of the first embodiment. That is, since a part of the data of the maps M1 to M5 is transmitted to the INJ side memory 23a and stored, the storage capacity required for the INJ side memory 23a can be reduced, and the ECU 30 transfers to the INJ side memory 23a. Data transmission time can be shortened.

  Further, the injection rate parameter corresponding to the region where the difference between the previous value and the current value is large is regarded as important data, and the important data (that is, the injection rate parameter corresponding to the update range W) is transmitted to the INJ side memory 23a and stored. Therefore, the deterioration in the accuracy of the injection control compared to the case where all data is transmitted to the INJ side memory 23a can be minimized.

(Third embodiment)
In the present embodiment, steps S11, S12, and S13 of FIG. 5 according to the first embodiment are changed to steps S11b, S12b, and S13b shown in FIG. In the first embodiment, the difference between the learning value and the master value is calculated for each region (S11), and the update range W is set based on the range of the region where the difference is large (difference large range W1) (S12). , S13).

  In contrast, in the present embodiment, in step S11b, the frequency of learning from the start to the end of engine operation or the frequency of learning from the time when the engine is shipped to the market is calculated for each region. In the subsequent step S12b, a range of regions having a high frequency among all regions (hereinafter referred to as a high frequency range) is calculated for each of the maps M1 to M5. For example, a predetermined number smaller than m × n may be set in advance, and a range including the predetermined number of regions in descending order of the frequency may be set as a large frequency range. For example, the range indicated by the halftone dots in FIG. 4 is a large frequency range for the map M1, and the large frequency range may be a set of a plurality of adjacent regions as shown in FIG. In some cases.

  In the subsequent step S13b (update range setting means), an update range W that is a range common to all the maps M1 to M5 is set based on the large frequency range for each map M1 to M5. For example, the update range W (see the shaded area in FIG. 4) may be set by averaging the large frequency range. More specifically, the center position of the large frequency range of each map M1 to M5 is calculated, and a predetermined number (9 in the example of FIG. 4) centered on the average of the center positions of each map M1 to M5 is updated. Set as range W.

  Incidentally, the large frequency ranges W1 to W5 calculated in this way tend to be almost common ranges in the maps M1 to M5. That is, the range of the region where the learning frequency increases at the engine operation start time and the end point, or the range of the region where the learning frequency decreases, is a common range for a plurality of types of injection rate parameters td, te, Rα, Rβ, Rmax. Tend to be.

  As described above, the present embodiment also exhibits the same effects as those of the first embodiment. That is, since a part of the data of the maps M1 to M5 is transmitted to the INJ side memory 23a and stored, the storage capacity required for the INJ side memory 23a can be reduced, and the ECU 30 transfers to the INJ side memory 23a. Data transmission time can be shortened.

  In addition, since the injection rate parameter with high learning frequency is highly likely to be used for injection control during the next operation, the injection rate parameter with high learning frequency and high availability for injection control is used as important data. Since the important data (that is, the injection rate parameter corresponding to the update range W) is transmitted to the INJ side memory 23a and stored, the accuracy of the injection control compared with the case where all the data is transmitted to the INJ side memory 23a. Deterioration can be minimized.

(Modification of the third embodiment)
In steps S12b and S13b of FIG. 7, the update range W is set based on the range of the region with a high learning frequency (large frequency range), but the region of the region with a low learning frequency (low frequency range) is set in step S12b. It may be calculated for each of the maps M1 to M5, and the update range W may be set based on the small frequency range in step S13b.

  Since the injection rate parameter having a low learning frequency is likely to have fewer learning opportunities during the next driving, the injection rate parameter having a low learning frequency and a low learning opportunity is regarded as important data in the INJ-side memory 23a. According to the present embodiment to be stored, the deterioration of the accuracy of the injection control compared to the case where all the data is transmitted to the INJ side memory 23a can be minimized.

(Fourth embodiment)
The present embodiment embodies the “other invention” described above. In addition, about the content of FIGS. 1-4 concerning the said 1st Embodiment, it is the same also in this embodiment.

  FIG. 8 is a graph showing one of the maps M1 to M5 in FIG. That is, it is a graph showing the value (Tq-Q characteristic line) of the injection command period Tq (injection rate parameter) with respect to the injection amount Q (environmental value) for each fuel pressure (environmental value) such as the reference pressure Pbase. Tq-Q characteristic lines for PA, PB, and PC are shown.

  FIG. 8A shows a master value (reference value) that is a Tq-Q characteristic line (master Tq-Q characteristic line) of a master fuel injection valve that serves as a reference, and that serves as a reference for determining machine difference variation. . 8B to 8E show a Tq-Q characteristic line (actual Tq-Q characteristic line) applied to the fuel injection valve 10 actually mounted on the engine. From the master Tq-Q characteristic line, FIG. Shows a shift. Further, the deviation changes due to aging degradation, etc., apart from the machine difference variation. And there are a plurality of patterns (change patterns CACE1 to CACE4) in the deviation, and FIGS. 8B to 8E show the change patterns.

  CACE1 shows a change pattern in which the Tq-Q characteristic line decreases as a whole at any fuel pressure PA, PB, PC. CACE2 shows a change pattern in which the Tq-Q characteristic line rises as a whole at any fuel pressure PA, PB, PC. CACE3 shows a change pattern in which the Tq-Q characteristic line of the fuel pressure PA increases as a whole and the Tq-Q characteristic line of the fuel pressure PC decreases as a whole. CACE4 shows a change pattern in which the Tq-Q characteristic line of the fuel pressure PA decreases as a whole and the Tq-Q characteristic line of the fuel pressure PC increases as a whole.

  In the present embodiment, the master Tq-Q characteristic line is stored in advance in the ECU-side memory 35, and the actual Tq-Q characteristic line acquired at the end of engine operation is compared with the master Tq-Q characteristic line. Then, it is determined which one of the plurality of change patterns CACE1 to 4 corresponds.

  Further, when the engine operation ends, the deviation amount of the actual Tq-Q characteristic line with respect to the master Tq-Q characteristic line is calculated. This deviation amount is calculated for the injection command period Tq for a specific fuel pressure and a specific injection amount Q (fixed point value). For example, the deviation of the values of the fixed point values A1 and A2 of the actual Tq-Q characteristic line with respect to the fixed point values A1m and A2m of the master Tq-Q characteristic line may be calculated as the deviation amount.

  FIG. 9 is a process executed by the microcomputer 34 of the ECU 30. First, in step S30, it is determined whether or not it is the end of engine operation based on whether or not the driver has turned off the ignition switch. To do. If it is determined that the engine operation is finished (S30: YES), in the subsequent step S31 (change pattern discriminating means), the change of the learning value (actual Tq-Q characteristic line) of the entire region with respect to the master Tq-Q characteristic line is It is determined which of the plurality of change patterns CACE1 to 4 corresponds.

  In the subsequent step S32 (change amount calculation means), a deviation amount between the fixed point values A1m and A2m of the master Tq-Q and the fixed point values A1 and A2 of the actual Tq-Q is calculated. In subsequent step S33 (transmission means), the corresponding pattern (change pattern information) determined in step S31 and the deviation amount (change amount information) calculated in step S32 are transmitted to the INJ side memory 23a and stored.

  As described above, by executing the processing of FIG. 9, the learning value change pattern information and the change amount information at the end of engine operation are transmitted and stored in the INJ-side memory 23a.

  FIG. 10 is a process executed by the microcomputer 34 of the ECU 30. First, in step S40, it is determined whether or not it is an engine operation start time based on whether or not the driver has turned on the ignition switch. To do. If it is determined that the engine operation start time is determined (S40: YES), in the subsequent step S41, the change pattern information and the change amount information stored in the INJ side memory 23a, that is, the corresponding pattern stored at the end of the previous engine operation. And read the amount of deviation.

  In the subsequent step S42, the actual Tq-Q for each fuel pressure PA, PB, PC at the end of the previous engine operation is estimated based on the corresponding pattern and deviation amount read in step S41. In other words, the injection rate parameter for the entire region, which is stored in the learning maps M1 to M5 at the end of the previous engine operation, is estimated.

  In the subsequent step S43, the injection rate parameters in the maps M1 to M5 stored in the ECU side memory 35 are rewritten to the injection rate parameters estimated in step S42.

  As described above, by executing the processing of FIG. 10, the corresponding pattern and the deviation amount stored in the INJ-side memory 23a at the end of the previous engine operation are read at the start of the current engine operation, and based on these information The data in the maps M1 to M5 in the ECU-side memory 35 is rewritten to the estimated learning value at the end of the previous engine operation.

  As described above, according to the present embodiment, since the change pattern information and the change amount information of the learning value are transmitted to the INJ side memory 23a and stored, it is required for the INJ side memory 23a as compared with the case of transmitting all data. Storage capacity can be reduced, and the data transmission time from the ECU 30 to the INJ-side memory 23a can be shortened.

  Here, the actual Tq-Q characteristic line (injection rate parameter) for each fuel pressure shown in FIG. 8A is set in advance in the fuel injection valve 10 so that the engine is in a predetermined operating state. The injection rate parameters as shown in FIGS. 8B to 8E tend to change in the entire range of the injection amount and the fuel pressure (environmental value) that are set as command values when the vehicle is operated.

  That is, as shown in FIGS. 8B and 8C, the injection amount Q with respect to the injection command value Tq at each fuel pressure is generally increased (FIG. 8B) or decreased (FIG. 8C). May change to do. Further, as shown in FIGS. 8D and 8E, the injection amount Q with respect to the injection command value Tq may change so as to decrease at a certain fuel pressure but increase at another fuel pressure.

  In any case, the actual Tq-Q characteristic line (injection rate parameter) for each fuel pressure indicates that the injection rate parameter change pattern is such that the injection amount Q with respect to the injection command value Tq increases or decreases as a whole. It is decided to some extent. Therefore, by knowing which pattern is changed every time the engine operation is completed and the deviation amount (change amount), the value of the injection rate parameter in the entire range of environmental values can be estimated.

  In view of this point, in the present embodiment, the corresponding pattern and the deviation amount are transmitted to the INJ side memory 23a, and the corresponding pattern and deviation amount stored in the INJ side memory 23a are transmitted to the ECU side memory 35 when the next operation of the engine is started. The above estimation can be realized. Therefore, even if the fuel injection valve 10 is replaced with another fuel injection valve, if the change pattern information and the change amount information stored in the INJ side memory 23a after the replacement are transmitted to the control side memory, the replacement is possible. It is possible to estimate the value of the injection rate parameter in the entire range of the environmental values related to the subsequent fuel injection valve, and to control (injection control) the operation of the fuel injection valve 10 based on the estimated value.

  Therefore, even when the fuel injection valve 10 is replaced after the engine is shipped to the market, the maps M1 to M5 based on the injection rate parameters suitable for the fuel injection valve 10 that is actually mounted, It can be created at the start of engine operation. Therefore, even when learning by the learning means 32 immediately after the start of engine operation is in the initial stage, the setting means 33 can set the injection command signal based on the highly accurate injection rate parameter, and the accuracy of injection control can be improved. .

(Modification 1 of 4th Embodiment)
In the process of FIG. 9, the deviation amount between the injection rate parameter distribution (master Tq-Q characteristic line) by the master fuel injection valve and the injection rate parameter distribution (actual Tq-Q characteristic line) by the engine fuel injection valve is stored in the INJ side memory. 23a. On the other hand, in the present modification, when the learning value at the end of the previous operation of the engine is the previous value and the learning value at the end of the current operation is the current value, the previous value for the entire region is stored in the ECU-side memory 35. , And the deviation amount between the injection value parameter distribution (actual Tq-Q characteristic line) of the previous value and the injection rate parameter distribution (actual Tq-Q characteristic line) of the current value is calculated, and the INJ side memory 23a Send to.

  Even if the deviation amount is calculated in this way, the value of the injection rate parameter in the entire range of the environmental value can be estimated in the same manner as the processing in FIGS. 9 and 10, and the operation of the fuel injection valve 10 is operated based on the estimated value. Can be controlled (injection control), and the same effect as in the fourth embodiment can be exhibited.

(Modification 2 of 4th Embodiment)
You may make it make a corresponding pattern common about each map M1-M5 of several types of injection rate parameters. For example, a corresponding pattern for each of the maps M1 to M5 may be calculated, and a common corresponding pattern may be determined by majority vote.

  Further, the deviation amount may be made common for each of the maps M1 to M5 of a plurality of types of injection rate parameters. For example, similarly to step S13 in FIG. 5, the average of the deviation amounts calculated for each of the maps M1 to M5 may be set as the common deviation amount.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  In each of the above embodiments, the injection amount and the fuel pressure are learned in association with the injection rate parameter as environment values, but only one of the injection amount and the fuel pressure may be learned as an environment value. . Further, learning may be performed in association with other environmental values (for example, injection interval, fuel temperature, etc.).

  In the above embodiment shown in FIG. 1, the fuel pressure sensor 20 is mounted on the fuel injection valve 10, but the fuel pressure sensor according to the present invention is in the fuel supply path from the discharge port 42a of the common rail 42 to the injection hole 11b. Any fuel pressure sensor may be used so long as it detects the fuel pressure. Therefore, for example, a fuel pressure sensor may be mounted on the high-pressure pipe 42 b that connects the common rail 42 and the fuel injection valve 10.

  DESCRIPTION OF SYMBOLS 10 ... 1st fuel injection valve, 20 ... Fuel pressure sensor, 23a ... INJ side memory (injection valve side memory), 30 ... ECU (control apparatus), 32 ... Learning means, 35 ... ECU side memory (control side memory), S13 , S13b ... update range setting means, S14 ... transmission means, W ... update range.

Claims (6)

A fuel injection valve for injecting fuel used for combustion of the internal combustion engine;
A fuel pressure sensor that detects a fuel pressure waveform that represents a change in the pressure of the fuel caused by fuel injection from the fuel injection valve; and
A control device that calculates an injection rate parameter required for specifying an injection rate waveform corresponding to the detected fuel pressure waveform based on the detected fuel pressure waveform, and controls the operation of the fuel injection valve based on the calculated injection rate parameter When,
A control-side memory mounted in the control device;
An injection valve side memory mounted on the fuel injection valve;
Applied to the fuel injection system with
The control device includes:
Learning means for storing and updating the calculated injection rate parameter in the control-side memory in association with an environmental value that affects the fuel injection state;
Update range setting means for setting a predetermined update range that is smaller than the entire range of the environmental values;
Transmitting means for transmitting, to the injection valve side memory, an injection rate parameter associated with the environmental value of the update range among the injection rate parameters stored in the control side memory at the end of operation of the internal combustion engine;
Equipped with a,
The control device calculates a plurality of types of the injection rate parameters based on the detected one fuel pressure waveform,
The learning means stores and updates a plurality of types of the injection rate parameters in the control-side memory in association with the environmental value,
The update range setting means sets the update range to a common range when setting the update range for each of a plurality of types of the injection rate parameters .   The update range setting means, of each of the injection rate parameters corresponding to the environment value, the injection rate parameter for which the stored update amount by the learning means is larger, the more of the environment value corresponding to the injection rate parameter. The fuel injection control device according to claim 1, wherein a range is preferentially included in the update range. The control-side memory stores a reference value of the injection rate parameter corresponding to each of the environmental values,
The fuel injection control device according to claim 2, wherein the storage update amount is a difference between the value of the injection rate parameter at the end of the operation and the reference value. When the value of the injection rate parameter corresponding to each of the environmental values, the value at the end of the previous operation of the internal combustion engine is the previous value, and the value at the end of the current operation is the current value,
The control side memory stores the previous value,
The fuel injection control device according to claim 2, wherein the storage update amount is a difference between the current value and the previous value.   The said update range setting means sets the said update range based on the frequency by which the memory update by the said learning means of each said injection rate parameter corresponding to the said environmental value was made | formed. 5. The fuel injection control device according to any one of 4. One of the environmental values is a pressure immediately before the fuel pressure waveform starts to drop with the start of fuel injection from the fuel injection valve, and the other is an injection amount of fuel from the fuel injection valve,
The learning means, a fuel injection control device according to any one of claims 1-5, characterized in that go by storing update the injection rate parameter associated with the pressure and the injection quantity of the immediately preceding.

Images