JP2022141273A - Injector control device - Google Patents

Abstract

To provide an injector control device capable of improving correction accuracy for fuel injection amount variation.SOLUTION: An injector control device 2 includes: a charge voltage control circuit 22 for charging electric energy in a capacitor when a charge voltage of the capacitor becomes a charge start threshold value or less, and halting the charge of electric energy when the charge voltage reaches at a charge completion threshold value; a charge voltage detection part 23 for detecting the charge voltage; an energization time correction part 211 for recognizing variation of the charge start threshold value or the charge completion threshold value based on the charge voltage acquired from the charge voltage detection part 23 and for correcting the energization time of an injector 4 according to the variation of the charge start threshold value or the charge completion threshold value; and an injector control circuit 24 for controlling the drive of the injector 4 based on the charge voltage supplied by the charge voltage control circuit 22 and the energization time corrected by the energization time correction part 211.SELECTED DRAWING: Figure 1

Description

The present invention relates to an injector control device that controls driving of an injector that injects fuel.

At the beginning of fuel injection, the injector control device supplies a boosted voltage obtained by boosting the voltage supplied from the battery, that is, the charge voltage of the capacitor to the solenoid coil of the injector to open the injector valve. Subsequently, the injector control device supplies the solenoid coil with a voltage lower than the charging voltage supplied at the beginning of fuel injection, ie, the voltage supplied from the battery, to the solenoid coil to keep the injector valve open. Subsequently, when a preset time of energizing the injector has elapsed since the start of energization of the injector, the injector control device stops supplying voltage to the solenoid coil, closes the valve of the injector, and stops fuel injection.

Patent Document 1 discloses a high-pressure injector control device as such an injector control device. The injection time correcting means of the high-pressure injector control device described in Patent Document 1 corrects the injection set time of the injector based on the boosting capability that indicates the amount of energy stored in the capacitor per unit time. According to the high-pressure injector control device described in Patent Literature 1, it is possible to suppress variations in the injection amount.

However, according to knowledge obtained by the present inventors, even when the injection set time of the injector is corrected based on the boosting capability, there are cases where the variation in the fuel injection amount cannot be suppressed. For example, when multi-stage injection is performed in which fuel injection is divided into a plurality of times for the purpose of noise reduction or the like, there are cases where pre-injection in which minute fuel injection is performed cannot suppress variation in the fuel injection amount. It should be noted that the variation in the fuel injection amount cannot be suppressed in some cases, not only in the case of blurring injection but also in the case of main injection.

JP 2016-113955 A

SUMMARY OF THE INVENTION An object of the present invention is to provide an injector control apparatus capable of improving the accuracy of correcting variations in fuel injection amount.

The above-mentioned problem is an injector control device for controlling the driving of an injector that injects fuel, wherein when the charging voltage of the capacitor becomes equal to or lower than a charging start threshold, electric energy is accumulated in the capacitor based on the voltage supplied from the battery, A charge voltage control circuit that stops accumulating the electrical energy when the charge voltage reaches a charge completion threshold, a charge voltage detection unit that detects the charge voltage, and the charge voltage detected by the charge voltage detection unit is acquired. Then, based on the charge voltage acquired from the charge voltage detection unit, the variation in the charge start threshold or the charge completion threshold is grasped, and the injector is energized according to the variation in the charge start threshold or the charge completion threshold. an energization time correction unit that corrects time; and an injector control circuit that controls driving of the injector based on the charge voltage supplied from the charge voltage control circuit and the energization time corrected by the energization time correction unit. and is solved by the injector control device according to the present invention.

According to the injector control device of the present invention, the energization time correction section acquires the charge voltage detected by the charge voltage detection section, and calculates the charge start threshold value or the charge completion threshold value based on the charge voltage acquired from the charge voltage detection section. to understand the variability of The charging initiation threshold is the charging voltage of the capacitor at which the charging voltage control circuit begins to store electrical energy in the capacitor. The charging completion threshold is the charging voltage of the capacitor when the charging voltage control circuit stops accumulating electrical energy in the capacitor, that is, the charging voltage of the capacitor when charging of the capacitor is completed. Further, the energization time correction unit corrects the energization time of the injector according to variations in the charge start threshold or the charge completion threshold. The injector control circuit controls the driving of the injector based on the charge voltage supplied from the charge voltage control circuit and the energization time of the injector corrected by the energization time corrector.

Here, according to knowledge obtained by the present inventors, the value of the charge voltage of the capacitor at the start of energization of the injector affects the fuel injection amount. Also, the time for the charge voltage of the capacitor to drop from the charge completion threshold to the charge start threshold due to natural discharge of the capacitor when the injector is not energized is much longer than the energization time of the injector and the time interval between fuel injections. Therefore, variations in the charging completion threshold greatly affect the value of the charging voltage of the capacitor at the start of energization of the injector. Moreover, since the variation in the charge completion threshold is equal to the variation in the charge start threshold, the variation in the charge start threshold also greatly affects the charge voltage value of the capacitor when the injector starts to conduct electricity. Then, the injector control device according to the present invention corrects the energization time of the injector according to variations in the charge start threshold value or the charge completion threshold value, which greatly affects the charge voltage value of the capacitor at the start of energization of the injector. As a result, the injector control device according to the present invention can improve the accuracy of correcting variations in the fuel injection amount.

In the injector control device according to the present invention, preferably, the energization time correction section acquires the charge voltage when the injector is not energized from the charge voltage detection section, and obtains the charge voltage obtained from the charge voltage detection section. variation in the charging start threshold value or the charging completion threshold value is grasped by executing the statistical processing of .

According to the injector control device of the present invention, the energization time corrector corrects variations in the charge start threshold or the charge completion threshold by performing statistical processing of the charge voltage acquired from the charge voltage detector when the injector is not energized. grasp. As a result, the energization time correction unit can accurately grasp the variation in the charging start threshold value or the charging completion threshold value by a simple process in a state where the injector is not driven.

In the injector control device according to the present invention, preferably, the energization time correcting section adjusts a plurality of the charge start thresholds or the charge completion thresholds in a plurality of cycles of charging and discharging of the capacitor occurring when the injector is not energized. By calculating an average value of a plurality of the charge start thresholds or the charge completion thresholds acquired from the voltage detection unit and the charge completion thresholds acquired from the charge voltage detection unit, variation in the charge start threshold or the charge completion threshold is grasped. Characterized by

According to the injector control device according to the present invention, the energization time correction unit calculates the average value of a plurality of charge start threshold values or charge completion threshold values, thereby grasping variations in charge start threshold values or charge completion threshold values. Through such processing, it is possible to accurately grasp the variation in the charging start threshold value or the charging completion threshold value, and to further improve the accuracy of correcting the variation in the fuel injection amount.

In the injector control device according to the present invention, preferably, the energization time correcting section adjusts a plurality of the charge start thresholds or the charge completion thresholds in a plurality of cycles of charging and discharging of the capacitor occurring when the injector is not energized. a plurality of the charge start thresholds or the charge completion thresholds obtained from the voltage detection unit and the remaining multiple charge start thresholds or the charge completion thresholds excluding the maximum value and the minimum value among the plurality of the charge start thresholds or the charge completion thresholds acquired from the charge voltage detection unit; It is characterized in that variations in the charging start threshold value or the charging completion threshold value are grasped by calculating an average value.

According to the injector control device according to the present invention, the energization time correction unit calculates the average value of the plurality of charge start thresholds or charge completion thresholds remaining after excluding the maximum value and the minimum value among the plurality of charge start thresholds or charge completion thresholds. Since the variation in the charge start threshold or the charge completion threshold is grasped by calculating , the variation in the charge start threshold or the charge completion threshold can be accurately grasped by a simple process, and the variation in the fuel injection amount can be corrected. Accuracy can be further improved.

The injector control device according to the present invention preferably further includes a storage unit that stores the energization time corrected by the energization time correction unit, and the injector control circuit stores the energization time corrected by the energization time correction unit. and controlling the driving of the injector based on the energization time stored in the .

According to the injector control device of the present invention, the injector control circuit drives the injector based on the injector energization time corrected by the energization time correction unit and stored in advance in the storage unit. Control. Therefore, the injector control circuit can control the driving of the injector at a faster processing speed based on the more accurate energization time of the injector.

In the injector control device according to the present invention, preferably, the energization time correction unit corrects the energization time in a production process, and the storage unit stores the energization time corrected by the energization time correction unit in the production process. is stored.

According to the injector control device of the present invention, the energization time correction section corrects the energization time of the injector in the production process. Further, the storage unit stores the energization time of the injector corrected by the energization time correction unit in the production process. As a result, even if the ECU (Electronic Control Unit) is replaced, the injector control device, which functions as part of the replaced electronic control unit, can correct the variation in the fuel injection amount. can be improved. Therefore, the electronic control unit can be easily replaced in the market after the injector control unit is shipped from the factory.

In the injector control device according to the present invention, preferably, the energization time correction unit corrects the energization time in the market after being shipped from the factory, and the storage unit corrects the energization time in the market by the energization time correction unit. The energization time is stored.

According to the injector control device of the present invention, the energization time correction section corrects the energization time of the injector in the market after being shipped from the factory. The storage unit stores the energization time of the injector corrected by the energization time correction unit in the market. As a result, even if the charging start threshold value or the charging completion threshold value changes in the market due to, for example, deterioration of the capacitor over time, the injector control device according to the present invention can improve the accuracy of correcting variations in the fuel injection amount. can.

Advantageous Effects of Invention According to the present invention, it is possible to provide an injector control device capable of improving the accuracy of correcting variations in fuel injection amount.

1 is a block diagram showing the main configuration of an injector control device according to an embodiment of the present invention; FIG. 4 is a graph illustrating an example of charge voltage when the injector of the present embodiment is not energized. 7 is a graph for explaining variations in charge start threshold and charge completion threshold; 4 is a timing chart illustrating an example of the operation of the injector control device according to the embodiment; 6 is a flow chart showing a specific example of processing executed by an energization time correction unit according to the embodiment;

Preferred embodiments of the invention are described in detail below with reference to the drawings.
Since the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are applied. Unless otherwise stated, the invention is not limited to these modes. Further, in each drawing, the same constituent elements are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a block diagram showing the essential configuration of an injector control device according to an embodiment of the present invention.
An injector control device 2 according to the present embodiment is mounted on, for example, a pre-chamber internal combustion engine, and controls driving of an injector 4 that injects fuel. As shown in FIG. 1, the injector control device 2 according to the present embodiment includes a microcomputer (hereinafter referred to as "microcomputer" for convenience of explanation) 21, a charge voltage control circuit 22, and a charge voltage detection section 23. , an injector control circuit 24, and a storage unit 25, and functions as part of an electronic control unit (ECU). In the following description, the microcomputer is called "microcomputer" for convenience of description.

Engine operation information 3 detected by various sensors is input to the injector control device 2 . As shown in FIG. 1, the engine operation information 3 includes, for example, a rotation signal related to the engine speed and a signal related to a driver request such as an accelerator opening.

As described above, the injector control device 2 controls driving of the injectors 4 . The injector 4 has a structure of a normally closed solenoid valve. For example, injector 4 has a solenoid coil, a plunger, a return spring, and a needle valve. When a voltage is supplied to the solenoid coil based on the control signal transmitted from the injector control device 2, the solenoid coil becomes an electromagnet and pulls the plunger while resisting the biasing force of the return spring. Then the needle valve opens. As a result, fuel is injected from a nozzle hole provided at the tip of the injector 4 . On the other hand, when the voltage supply to the solenoid coil is stopped based on the control signal transmitted from the injector control device 2, the solenoid coil loses its magnetic force. Then, the plunger and the node valve return to their original positions under the biasing force of the return spring, closing the nozzle hole. This stops the fuel injection.

The microcomputer 21 has a function as a CPU (Central Processing Unit), reads programs stored in the storage unit 25, and executes various calculations and processes. The microcomputer 21 also has an energization time corrector 211 that corrects the energization time of the injector 4 . Details of the energization time correction unit 211 will be described later.

The charge voltage control circuit 22 functions as a so-called booster circuit, and has a coil, a capacitor, a switching element such as a transistor, and a rectifying element such as a diode. The charge voltage control circuit 22 switches ON/OFF of the switching element to boost the voltage supplied from the battery, and stores electric energy in the capacitor. That is, the charge voltage control circuit 22 accumulates electrical energy in the capacitor based on the voltage supplied from the battery.

The charge voltage detector 23 detects the voltage of the capacitor, that is, the charge voltage. Then, the charge voltage detection unit 23 transmits a signal regarding the detected charge voltage of the capacitor to the microcomputer 21 .
The energization time correction unit 211 acquires the charge voltage of the capacitor detected by the charge voltage detection unit 23 and sets the energization time of the injector 4 based on the charge voltage of the capacitor acquired from the charge voltage detection unit 23 .

The injector control circuit 24 controls driving of the injector 4 based on the charge voltage supplied from the charge voltage control circuit 22 and the energization time set by the energization time corrector 211 . For example, at the beginning of fuel injection, the injector control circuit 24 supplies a boosted voltage obtained by boosting the voltage supplied from the battery, that is, the charge voltage of the capacitor to the solenoid coil of the injector 4 to open the needle valve of the injector 4 . That is, the boosted voltage generated by the charge voltage control circuit 22, ie, the charge voltage, is supplied to the injector 4 via the injector control circuit 24. As shown in FIG. Further, when the energization time set by the energization time correction unit 211 elapses from the time when the energization of the injector 4 is started (that is, the time when the voltage supply to the injector 4 is started), the injector control circuit 24 controls the solenoid coil of the injector 4. stop supplying voltage to

The storage unit 25 stores (memorizes) programs executed by the microcomputer 21 . Examples of the storage unit 25 include ROM (Read Only Memory) and RAM (Random Access Memory). Note that the storage unit 25 may be an external storage device connected to the injector control device 2 .

In the injector control device 2 according to this embodiment, the charge voltage control circuit 22, the charge voltage detection unit 23, the injector control circuit 24, and the energization time correction unit 211 execute programs stored in the storage unit 25. It may be realized by execution by the microcomputer 21, may be realized by hardware, or may be realized by a combination of hardware and software.

Next, the charge voltage control circuit 22 of this embodiment will be further described with reference to the drawings.
FIG. 2 is a graph illustrating an example of charge voltage when the injector of the present embodiment is not energized.
FIG. 3 is a graph illustrating variations in charge start threshold and charge completion threshold.

As shown in FIG. 2, when the charge voltage VCHG of the capacitor becomes equal to or lower than the charge start threshold VL (timing t11), the charge voltage control circuit 22 accumulates electrical energy in the capacitor based on the voltage supplied from the battery. In other words, the charge start threshold VL in this embodiment is the charge voltage VCHG of the capacitor when the charge voltage control circuit 22 starts accumulating electrical energy in the capacitor. As a result, the charge voltage VCHG of the capacitor rises (timing t11 to timing t12). Subsequently, when the charge voltage VCHG of the capacitor reaches the charge completion threshold value VH (timing t12), the charge voltage control circuit 22 stops accumulating electrical energy in the capacitor. That is, the charging completion threshold VH of the present embodiment is the charging voltage VCHG of the capacitor when the charging voltage control circuit 22 stops accumulating electrical energy in the capacitor, that is, the charging voltage VCHG of the capacitor when charging of the capacitor is completed. be.

Subsequently, when the injector is de-energized, natural discharge of the capacitor occurs (timing t12-timing t13). That is, even if the capacitor charge voltage VCHG is not supplied to the injector 4 via the injector control circuit 24, the capacitor charge voltage VCHG naturally decreases over time (timing t12 to timing t13).

Then, when the charge voltage VCHG of the capacitor becomes equal to or lower than the charge start threshold VL (timing t13), the charge voltage control circuit 22 accumulates electric energy in the capacitor based on the voltage supplied from the battery. As a result, the charge voltage VCHG of the capacitor rises again (timing t13 to timing t14). Subsequently, when the charge voltage VCHG of the capacitor reaches the charge completion threshold value VH again (timing t14), the charge voltage control circuit 22 stops accumulating electric energy in the capacitor again.

In this manner, when the injector is not energized, natural discharge of the capacitor occurs repeatedly, and electric energy is repeatedly stored in the capacitor. The time required for the charge voltage VCHG of the capacitor to decrease from the charge completion threshold VH to the charge start threshold VL or less is, for example, approximately 2 seconds or more and 4 seconds or less.

Here, in the injector control device 2, individual differences exist in the charging voltage control circuit 22. FIG. The individual differences of the charge voltage control circuit 22 are caused by variations in the capacitance component and resistance component of the capacitors included in the charge voltage control circuit 22 and variations in the inductance component and resistance component of the coil included in the charge voltage control circuit 22 . Alternatively, individual differences in charge voltage control circuit 22 are caused by manufacturing tolerances, temperature tolerances, endurance tolerances, and the like of respective elements such as capacitors and coils included in charge voltage control circuit 22 . It should be noted that factors causing individual differences in the charge voltage control circuit 22 are not limited to these.

Due to individual differences in the charge voltage control circuit 22, there are variations in the charge start threshold VL and the charge completion threshold VH. As shown in FIG. 3, in the charge voltage control circuit 22A, the charge start threshold VL is 66.0V and the charge completion threshold VH is 67.5V. In the charge voltage control circuit 22B, the charge start threshold VL is 64.0V and the charge completion threshold VH is 66.0V. In the charge voltage control circuit 22C, the charge start threshold VL is 62.0V and the charge completion threshold VH is 64.5V. In this way, due to individual differences in the charge voltage control circuit 22, the charge start threshold VL varies by about 62.0 V or more and 66.0 V or less. In addition, due to individual differences in the charge voltage control circuit 22, the charge completion threshold VH varies by approximately 64.5 V or more and 67.5 V or less.

As shown in FIG. 3, in the charge voltage control circuit 22, there are variations in the set of the charge start threshold VL and the charge completion threshold VH. That is, when the charge start threshold VL becomes relatively high, the charge completion threshold VH also becomes relatively high. On the other hand, when the charging start threshold VL becomes relatively low, variations occur such that the charging completion threshold VH also becomes relatively low.

As shown in FIG. 3, in each of the charge voltage control circuits 22A, 22B, and 22C, when the injector is not energized, natural discharge of the capacitor occurs repeatedly (timing t22 to timing t23), and the electric energy in the capacitor Accumulation is repeatedly executed (timing t21 to timing t22 and timing t23 to timing t24).

Here, if there are variations in the charge start threshold VL and the charge completion threshold VH, variations in the fuel injection amount occur. For example, when multi-stage injection is performed in which fuel injection is divided into a plurality of times for the purpose of noise reduction or the like, there are cases where pre-injection in which minute fuel injection is performed cannot suppress variation in the fuel injection amount. It should be noted that the variation in the fuel injection amount cannot be suppressed in some cases, not only in the case of blurring injection but also in the case of main injection.

On the other hand, the energization time correction unit 211 of the injector control device 2 according to this embodiment acquires the charge voltage VCHG of the capacitor detected by the charge voltage detection unit 23, and the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23. Variations in the charge start threshold VL or the charge completion threshold VH are grasped based on the charge voltage VCHG. Further, the energization time correction unit 211 corrects the energization time of the injector 4 in accordance with variations in the charging start threshold VL or the charging completion threshold VH. The injector control circuit 24 controls the driving of the injector 4 based on the charge voltage VCHG of the capacitor supplied from the charge voltage control circuit and the energization time of the injector 4 corrected by the energization time corrector 211. .

Note that the energization time correction unit 211 may grasp variations in at least one of the charge start threshold VL and the charge completion threshold VH based on the charge voltage VCHG of the capacitor obtained from the charge voltage detection unit 23 . In other words, the energization time correction unit 211 may grasp variations in only the charge start threshold VL or only in the charge completion threshold VH, based on the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23 . Alternatively, variations in both the charging start threshold VL and the charging completion threshold VH may be grasped. This also applies to the following description of this embodiment.

Further, the energization time correction unit 211 may correct the energization time of the injector 4 according to variations in at least one of the charging start threshold VL and the charging completion threshold VH. In other words, the energization time correction unit 211 may correct the energization time of the injector 4 according to variations in only the charge start threshold VL, or may correct the energization time of the injector 4 in accordance with variations in only the charge completion threshold VH. Alternatively, the energization time of the injector 4 may be corrected according to variations in both the charging start threshold VL and the charging completion threshold VH. This also applies to the following description of this embodiment.

The operation of the injector control device 2 according to this embodiment will be described in detail below with reference to the drawings.
FIG. 4 is a timing chart illustrating an example of the operation of the injector control device according to this embodiment.

First, at the start of fuel injection, the injector control circuit 24 supplies the boosted voltage generated by the charge voltage control circuit 22, that is, the charge voltage VCHG of the capacitor to the solenoid coil of the injector 4 (timing t31). At timing t31 shown in FIG. 4, the charge voltage VCHG of the capacitor slightly drops from the charge completion threshold VH due to natural discharge of the capacitor. Subsequently, the current flowing through the solenoid coil of the injector 4 reaches its peak (timing t32). Thus, at the beginning of fuel injection, a peak current flows through the solenoid coil of the injector 4 (timing t32).

At the beginning of fuel injection, the charge voltage supplied to the solenoid coil of the injector 4 is, for example, approximately 65±3V. Also, the peak current flowing through the solenoid coil of the injector 4 is, for example, about 14.0±0.35A.

As shown in FIG. 4, at the beginning of fuel injection, the charge voltage VCHG of the capacitor is supplied to the solenoid coil of the injector 4 and becomes equal to or lower than the charging start threshold VL, so the current flowing through the solenoid coil of the injector 4 reaches its peak. Upon reaching, the charge voltage control circuit 22 starts accumulating electrical energy in the capacitor based on the voltage supplied from the battery (timing t32). Then, when the charge voltage VCHG of the capacitor reaches the charge completion threshold value VH, the charge voltage control circuit 22 stops accumulating electric energy in the capacitor (timing t33).

Further, when the current flowing through the solenoid coil of the injector 4 reaches a peak, the injector control circuit 24 causes the solenoid coil of the injector 4 to apply a voltage lower than the charge voltage VCHG supplied at the beginning of fuel injection, that is, the voltage supplied from the battery. to keep the needle valve of the injector 4 open (timing t32 to timing t34). The average value of the current (hold current) flowing through the solenoid coil of the injector 4 to keep the needle valve of the injector 4 open is, for example, about 3.4A.

Subsequently, when the energization time set by the energization time correction unit 211 elapses from the time when the energization of the injector 4 is started (that is, the time when the supply of voltage to the solenoid coil of the injector 4 is started: timing t31), the injector control circuit 24 stops supplying voltage to the solenoid coil of the injector 4 (timing t34). The time from when the injector control circuit 24 starts energizing the injector 4 to when it stops energizing the injector 4 (timing t31 to timing t34) is about 0.2 milliseconds or more and 1.5 milliseconds or less. .

Subsequently, when several hundred microseconds or several milliseconds have passed since the injector control circuit 24 stopped energizing the injector 4, the injector control circuit 24 changes the boosted voltage generated by the charge voltage control circuit 22, i.e. The charge voltage VCHG of the capacitor is again supplied to the solenoid coil of the injector 4 (timing t35). The operation of the injector control device 2 from timing t35 to timing t38 is the same as the operation of the injector control device 2 described above with respect to timing t31 to timing t34. The time from when the injector control circuit 24 starts energizing the injector 4 to when it stops energizing the injector 4 (timing t35 to timing t38) is about several milliseconds.

For example, fuel injection at timings t31 to t34 shown in FIG. 4 is an example of pre-injection of multi-stage injection. For example, fuel injection from timing t35 to timing t38 shown in FIG. 4 is an example of main injection of multi-stage injection. However, the fuel injection from timing t31 to timing t34 shown in FIG. 4 is not limited to pre-injection of multi-stage injection. Further, the fuel injection at the timings t35 to t38 shown in FIG. 4 is not limited to the main injection of the multi-stage injection.

Here, according to knowledge obtained by the present inventors, the value of the charge voltage VCHG of the capacitor at the start of energization of the injector 4, that is, the value of the charge voltage VCHG of the capacitor at the timings t31 and t35 shown in FIG. Affects the fuel injection amount.

For example, when the charge voltage VCHG of the capacitor at the start of energization of the injector 4 is relatively high, the rise of the current flowing through the solenoid coil of the injector 4 is relatively high between timings t31 and t32 and between timings t35 and t36. early. In other words, when the charge voltage VCHG of the capacitor at the start of energization of the injector 4 is relatively high, the slope of the current flowing through the solenoid coil of the injector 4 (unit The amount of change in current per time (the rate of change in current) is relatively large. Therefore, when the value of the charge voltage VCHG of the capacitor at the start of energization of the injector 4 is relatively high, the fuel injection amount is relatively large during a constant energization time of the injector 4 .

On the other hand, when the value of the charge voltage VCHG of the capacitor at the start of energization of the injector 4 is relatively low, the current flowing through the solenoid coil of the injector 4 rises relatively at timings t31 to t32 and at timings t35 to t36. relatively late. In other words, when the charge voltage VCHG of the capacitor at the start of energization of the injector 4 is relatively low, the slope of the current flowing through the solenoid coil of the injector 4 (unit The amount of change in current per time (rate of change in current) is relatively small. Therefore, when the value of the charge voltage VCHG of the capacitor at the start of energization of the injector 4 is relatively low, the amount of fuel injected during a constant energization time of the injector 4 is relatively small.

Further, as described above, the value of the charging voltage VCHG of the capacitor decreases from the charge completion threshold value VH to the charge start threshold value VL due to the natural discharge of the capacitor when the injector 4 is not energized (timing t12 to timing VL shown in FIG. 2). t13 and timing t22 to timing t23 shown in FIG. 3) is longer than the energization time of the injector 4 (timing t31 to timing t34 and timing t35 to timing t38) and the time interval between fuel injections (timing t34 to timing t35). very long. Therefore, variations in the charge start threshold value VL or the charge completion threshold value VH greatly affect the value of the charge voltage of the capacitor when the injector 4 starts energizing. That is, as described above with reference to FIG. 3, in the charge voltage control circuit 22, there is variation in the set of the charge start threshold value VL and the charge completion threshold value VH. As described above, the variation in the charge completion threshold VH is equal to the variation in the charge start threshold VL, so the variation in the charge start threshold VL also greatly affects the charge voltage value of the capacitor when the injector starts energizing.

On the other hand, the energization time correction unit 211 of the injector control device 2 according to this embodiment acquires the charge voltage VCHG of the capacitor detected by the charge voltage detection unit 23, and the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23. Variations in the charge start threshold VL or the charge completion threshold VH are grasped based on the charge voltage VCHG. Further, the energization time correction unit 211 corrects the energization time of the injector 4 in accordance with variations in the charging start threshold VL or the charging completion threshold VH.

Specifically, as in the charge voltage control circuit 22A described above with reference to FIG. Perform a relative shortening correction. On the other hand, as in the charge voltage control circuit 22C described above with reference to FIG. perform a correction that lengthens the

The injector control circuit 24 controls the driving of the injector 4 based on the charge voltage VCHG of the capacitor supplied from the charge voltage control circuit and the energization time of the injector 4 corrected by the energization time corrector 211. .

According to the injector control device 2 according to the present embodiment, energization of the injector 4 is performed according to variations in the charge start threshold VL or the charge completion threshold VH, which greatly affect the value of the charge voltage VCHG of the capacitor when the injector 4 starts energization. correct the time. As a result, the injector control device 2 according to the present embodiment can improve the correction accuracy of the variation in fuel injection amount.

Further, the storage unit 25 of the present embodiment stores the energization time of the injector 4 corrected by the energization time correction unit 211 . The injector control circuit 24 controls driving of the injector 4 based on the energization time of the injector 4 corrected by the energization time correction unit 211 and stored in advance in the storage unit 25 . As a result, the injector control circuit 24 can control the driving of the injector 4 at a faster processing speed based on the more accurate energization time of the injector 4 .

Next, a specific example of the process of grasping variations in the charging start threshold value VL or the charging completion threshold value VH by the energization time correction unit 211 of the present embodiment will be described in detail with reference to the drawings.
FIG. 5 is a flow chart showing a specific example of processing executed by the energization time correction unit of the present embodiment.

In this specific example, the energization time correction unit 211 acquires the charge voltage VCHG of the capacitor when the injector 4 is not energized from the charge voltage detection unit 23, and statistically processes the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23. to grasp variations in the charge start threshold VL or the charge completion threshold VH. Processing executed by the energization time correction unit 211 will be described below with reference to the flowchart shown in FIG.

First, in step S11, the charge voltage control circuit 22 accumulates electrical energy in the capacitor based on the voltage supplied from the battery. to stop. This completes the initial charge.

Subsequently, in step S12, the charge voltage control circuit 22 determines whether or not the charge voltage VCHG of the capacitor is equal to or lower than the charge start threshold value VL. If the charge voltage VCHG of the capacitor is not equal to or lower than the charge start threshold VL (step S12: NO), in step S12, the charge voltage control circuit 22 determines whether the charge voltage VCHG of the capacitor is equal to or lower than the charge start threshold VL. continue to judge.

On the other hand, if the charge voltage VCHG of the capacitor is equal to or lower than the charge start threshold VL (step S12: YES), in step S13, the charge voltage control circuit 22 applies electric energy to the capacitor based on the voltage supplied from the battery. is accumulated (charging starts).

Subsequently, in step S14, the charge voltage control circuit 22 determines whether or not the charge voltage VCHG of the capacitor has reached the charge completion threshold value VH. If the capacitor charge voltage VCHG has not reached the charge completion threshold VH, in step S14, the charge voltage control circuit 22 continues to determine whether or not the capacitor charge voltage VCHG has reached the charge completion threshold VH. .

On the other hand, when the charge voltage VCHG of the capacitor reaches the charge completion threshold value VH, the charge voltage control circuit 22 stops accumulating electrical energy in the capacitor (stops charging) in step S15.

Subsequently, in step S16, the energization time correction unit 211 acquires the charge voltage VCHG of the capacitor when the injector 4 is not energized from the charge voltage detection unit 23, and starts logging the charge voltage VCHG of the capacitor.

Subsequently, in step S17, the charge voltage control circuit 22 determines whether or not the charge voltage VCHG of the capacitor is equal to or lower than the charge start threshold value VL. Here, in step S16, the energization time correction unit 211 acquires the charge voltage VCHG of the capacitor when the injector 4 is not energized from the charge voltage detection unit 23. Therefore, in step S17, the charge voltage control circuit 22 corrects the capacitor It is determined whether or not the charge voltage VCHG of has become equal to or less than the charge start threshold value VL due to natural discharge of the capacitor.

When the charge voltage VCHG of the capacitor is not equal to or lower than the charge start threshold VL (step S17: NO), in step S17, the charge voltage control circuit 22 determines whether the charge voltage VCHG of the capacitor is equal to or lower than the charge start threshold VL. continue to judge. On the other hand, if the charge voltage VCHG of the capacitor is equal to or lower than the charge start threshold VL (step S17: YES), the energization time correction unit 211 stops logging the charge voltage VCHG of the capacitor in step S18.

Subsequently, in step S19, the energization time correction unit 211 determines the charging start threshold value based on the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23, that is, based on the logging results executed in steps S16 to S18. Grasp variation in VL or charge completion threshold VH. Although not shown in FIG. 5, steps S11 to S18 may be executed multiple times. At this time, the energization time correction unit 211 grasps variations in the charge start threshold value VL or the charge completion threshold value VH by performing statistical processing of the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23 .

For example, the energization time correction unit 211 acquires from the charge voltage detection unit 23 a plurality of charge start thresholds VL or charge completion thresholds VH in a plurality of cycles of charging and discharging of the capacitor that occur when the injector 4 is not energized. By calculating the average value of a plurality of charge start threshold values VL or charge completion threshold values VH acquired from 23, variations in charge start threshold value VL or charge completion threshold value VH are grasped. For example, the energization time correction unit 211 acquires from the charge voltage detection unit 23 five charge start threshold values VL or charge completion threshold values VH for five cycles of charging and discharging of the capacitor that occur when the injector 4 is not energized, and five charge start threshold values are obtained. By calculating the average value of the threshold value VL or the charge completion threshold value VH, variations in the charge start threshold value VL or the charge completion threshold value VH are grasped.

Alternatively, for example, the energization time correction unit 211 acquires from the charge voltage detection unit 23 a plurality of charge start thresholds VL or charge completion thresholds VH in a plurality of cycles of charging and discharging of the capacitor that occur when the injector 4 is not energized, and the charge voltage Charging is started by calculating the average value of the plurality of charge start thresholds VL or charge completion thresholds VH after excluding the maximum and minimum values of the plurality of charge start thresholds VL or charge completion thresholds VH acquired from the detection unit 23 Grasping the variation of the threshold VL or the charge completion threshold VH. For example, the energization time correction unit 211 acquires from the charge voltage detection unit 23 five charge start threshold values VL or charge completion threshold values VH for five cycles of charging and discharging of the capacitor that occur when the injector 4 is not energized, and five charge start threshold values are obtained. Variations in the charge start threshold VL or the charge completion threshold VH are calculated by calculating the average value of the remaining three charge start thresholds VL or the charge completion threshold VH excluding the maximum and minimum values of the threshold VL or the charge completion threshold VH. grasp.

Subsequently, in step S19, the energization time correction unit 211 corrects the energization time of the injector 4 according to the grasped variations in the charge start threshold VL or the charge completion threshold VH. For example, an example in which the energization time correction unit 211 corrects the energization time of the injector 4 in accordance with variations in the charge start threshold VL or the charge completion threshold VH will be described below.

That is, if the inductance of the solenoid coil of the injector 4 is L and the current flowing through the solenoid coil of the injector 4 at time (t) is I(t), then the formula: I(t)=(V/L)×t holds. do. Therefore, the current when the injector 4 is energized is proportional to the voltage. Also, as a formula for the self-induced electromotive force generated in the coil, the formula: ΔI/Δt=V/L holds. Therefore, the energization time correction unit 211 grasps the variation in the charge start threshold VL or the charge completion threshold VH, and the current flowing through the solenoid coil of the injector 4 is the target for each capacitor charge voltage VCHG at the start of energization of the injector 4. It is possible to calculate the time (t) until the current (for example, the current for opening the needle valve of the injector 4) is reached.

The energization time correction unit 211 may calculate the absolute value of the energization time of the injector 4 as the correction value. Alternatively, the energization time correction unit 211 may calculate a ratio coefficient of the energization time of the injector 4 with respect to the reference value (typ) as the correction value. Then, the energization time correction unit 211 stores the calculated absolute value or ratio coefficient as the correction value in the storage unit 25 .

According to this specific example, the energization time correction unit 211 performs statistical processing on the charge voltage VCHG of the capacitor acquired from the charge voltage detection unit 23 when the injector 4 is not energized. Grasping VH variation. As a result, the energization time correction unit 211 can accurately ascertain variations in the charging start threshold VL or the charging completion threshold VH through a simple process when the injector 4 is not driven.

In addition, the energization time correction unit 211 grasps variations in the charge start threshold VL or the charge completion threshold VH by, for example, calculating an average value of a plurality of charge start thresholds VL or charge completion thresholds VH. In this case, the energization time correction unit 211 can accurately grasp the variation in the charge start threshold value VL or the charge completion threshold value VH by simple processing, and further improve the accuracy of correcting the variation in the fuel injection amount. can be made

Further, the energization time correction unit 211 calculates, for example, the average value of the plurality of charge start thresholds VL or the charge completion thresholds VH remaining after excluding the maximum value and the minimum value among the charge start thresholds VL or the plurality of charge completion thresholds VH. By doing so, variations in the charge start threshold value VL or the charge completion threshold value VH are grasped. In this case, the energization time correction unit 211 can accurately grasp the variation in the charge start threshold value VL or the charge completion threshold value VH by simple processing, and further improve the accuracy of correcting the variation in the fuel injection amount. can be made

Further, the injector control circuit 24 stores at least one of the absolute value of the energization time of the injector 4 calculated by the energization time correction unit 211 and the ratio coefficient of the energization time of the injector 4 with respect to the reference value (typ). 25, the driving of the injector 4 is controlled based on at least one of the absolute value and the ratio coefficient stored in advance. Therefore, the injector control circuit 24 can control the driving of the injector 4 at a higher processing speed based on the more accurate energization time of the injector 4 .

The energization time correction unit 211 can execute the process of the specific example described with reference to FIG. That is, the energization time correction unit 211 can correct the energization time of the injector 4 in the production process. Further, the storage unit 25 can store the energization time of the injector 4 corrected by the energization time correction unit 211 in the production process. As a result, even when the electronic control unit (ECU) is replaced, the injector control unit 2, which functions as a part of the post-replacement electronic control unit, can improve the accuracy of correcting variations in the fuel injection amount. can be done. Therefore, in the market after the injector control device 2 according to this embodiment is shipped from the factory, the electronic control device can be easily replaced.

Further, the energization time correction unit 211 can execute the processing of the specific example described with reference to FIG. 5 in the market after the injector control device 2 is shipped from the factory. That is, the energization time correction unit 211 can correct the energization time of the injector 4 in the market after being shipped from the factory. Further, the storage unit 25 can store the energization time of the injector 4 corrected by the energization time correction unit 211 in the market. As a result, even if the charging start threshold value VL or the charging completion threshold value VH changes in the market due to, for example, deterioration of the capacitor over time, the injector control device 2 according to the present embodiment can correct the variation in the fuel injection amount. can be improved.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. Some of the configurations of the above embodiments may be omitted, or may be arbitrarily combined in a manner different from the above.

2: Injector control device 3: Engine operation information 4: Injector 21: Microcomputer 22, 22A, 22B, 22C: Charge voltage control circuit 23: Charge voltage detection unit 24: Injector control circuit 25: Storage unit , 211: energization time correction unit, VCHG: charge voltage, VH: charge completion threshold, VL: charge start threshold

Claims (7)

An injector control device that controls driving of an injector that injects fuel,
Charge voltage control for accumulating electric energy in the capacitor based on the voltage supplied from the battery when the charge voltage of the capacitor becomes equal to or lower than the charge start threshold, and stopping the accumulation of the electric energy when the charge voltage reaches the charge completion threshold. a circuit;
a charge voltage detection unit that detects the charge voltage;
acquiring the charge voltage detected by the charge voltage detection unit; grasping variations in the charge start threshold or the charge completion threshold based on the charge voltage acquired from the charge voltage detection unit; an energization time correction unit that corrects the energization time of the injector according to the variation in the charging completion threshold;
an injector control circuit that controls driving of the injector based on the charge voltage supplied from the charge voltage control circuit and the energization time corrected by the energization time correction unit;
An injector control device comprising: The energization time correction unit acquires the charge voltage when the injector is not energized from the charge voltage detection unit, and performs statistical processing on the charge voltage acquired from the charge voltage detection unit to obtain the charge start threshold value. 2. The injector control device according to claim 1, further comprising grasping variations in the charging completion threshold. The energization time correction unit acquires from the charge voltage detection unit a plurality of the charge start threshold values or the charge completion threshold values in a plurality of cycles of charging and discharging of the capacitor occurring when the injector is not energized, and the charge voltage detection unit 3. The injector control device according to claim 2, wherein variations in the charge start threshold or the charge completion threshold are calculated by calculating an average value of the plurality of charge start thresholds or the charge completion thresholds obtained from . The energization time correction unit acquires from the charge voltage detection unit a plurality of the charge start threshold values or the charge completion threshold values in a plurality of cycles of charging and discharging of the capacitor occurring when the injector is not energized, and the charge voltage detection unit By calculating the average value of the remaining plurality of the charge start thresholds or the charge completion thresholds excluding the maximum value and the minimum value among the plurality of the charge start threshold values or the charge completion threshold values acquired from the charge start threshold value or the charge completion threshold value 3. The injector control device according to claim 2, wherein variations in the charging completion threshold are grasped. further comprising a storage unit that stores the energization time corrected by the energization time correction unit;
5. The injector control circuit according to claim 1, wherein the injector control circuit controls driving of the injector based on the energization time corrected by the energization time correction unit and stored in the storage unit. The injector controller as described. The energization time correction unit corrects the energization time in a production process,
6. The injector control device according to claim 5, wherein the storage unit stores the energization time corrected by the energization time correction unit in the production process. The energization time correction unit corrects the energization time in the market after being shipped from the factory,
6. The injector control device according to claim 5, wherein the storage unit stores the energization time corrected by the energization time correction unit in the market.

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