JP2006077627A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device preventing deviation between target injection quantity and actual injection quantity without increasing load of a control device even if power source voltage drops. <P>SOLUTION: A control device measures power source voltage and changes a target value of first fixed current I1 for lifting a needle according to the measured value, and corrects electricity carry start timing command value and electricity carry period command value according to the target value. Consequently, the target value of first fixed current I1 can be changed to a lower value which has margin in relation to power source voltage. As a result, it is not necessary to always monitor power source voltage. Moreover, even if needle lift condition fluctuates with accompanying drop of the target value of first fixed current I1, deviation of the target injection quantity and actual injection quantity can be prevented by correcting electricity carry start timing command value and electricity carry period command value. Consequently, deviation of target injection quantity and actual injection quantity can be prevented without always monitoring power source voltage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection device that injects and supplies fuel to an internal combustion engine (engine).

[Conventional technology]
2. Description of the Related Art Conventionally, a fuel injection device that injects and supplies fuel to an engine includes an injector that is mounted on a cylinder of the engine and injects and supplies fuel into the cylinder. The injector includes a body in which a fuel passage and an injection hole are formed, a needle that is accommodated in the body, opens and closes the injection hole, and an electromagnetic actuator that lifts the needle.

  When the solenoid of the electromagnetic actuator is energized, a magnetic attractive force is generated, and the needle is lifted directly or indirectly by this magnetic attractive force to open the nozzle hole. Thereby, fuel injection is started. When the energization of the solenoid is stopped, the magnetic attractive force disappears and the needle closes the nozzle hole. Thereby, the fuel injection is completed.

  By the way, the energization current to the solenoid changes in one energization period (corresponding to one injection period), for example, as shown in FIG. That is, at the start of energization, the peak current Ip is energized, thereafter the first constant current I1 lower than the peak current Ip is energized, and thereafter the second constant current I2 lower than the first constant current I1 is energized. Thus, one energization period ends.

  The peak current Ip is energized in order to instantaneously generate a very large magnetic attractive force and start the needle lift. That is, an extremely large urging force acts on a member such as a needle to be driven by a magnetic attractive force in order to seal high-pressure fuel, and driving of the member such as a needle is started against this urging force. This is because an extremely large magnetic attractive force is required.

The first constant current I1 is energized in order to continuously generate a magnetic attractive force that can lift the needle to a predetermined holding position. For this reason, the first constant current I1 does not require a current as high as the peak current Ip, and is set smaller than the peak current Ip.
The second constant current I2 is energized in order to continuously generate a magnetic attractive force that can hold the needle that has stopped lifting at a predetermined holding position. For this reason, the second constant current I2 is set smaller than the first constant current I1 for continuing the needle lift.

  The energization control to the solenoid is performed by a control device constituting the fuel injection device. The control device boosts and charges the power supply voltage, discharges the charged high voltage, and supplies the peak current Ip to the solenoid. The control device sets the energization amount to the solenoid to the first and second constant currents. There are provided constant current control means for controlling the target values of I1 and I2, current detection means for detecting energization current to the solenoid, and a microcomputer (microcomputer) for outputting a command signal for operating these means.

  Here, since the microcomputer causes the injector to inject and supply fuel of an injection amount (target injection amount) according to the engine operating state, various signals indicating the operating state of the engine are input, and the injector is based on these signals. A command value for controlling the fuel injection is calculated. Then, the microcomputer outputs a command signal for performing energization control based on these command values and target values of the first and second constant currents to the high voltage applying unit and the constant current control unit. Then, in response to a command signal from the microcomputer, the high voltage applying means first causes the peak current Ip to flow through the solenoid, and then the constant current control means sequentially applies the energized current to the first and second constant currents I1 and I2. Control to value.

  In addition, the constant current control means, for example, a comparison circuit that compares the current value of the energization amount detected by the current detection means with a target value of the energization amount commanded by the microcomputer, and according to a control signal from this comparison circuit And a control circuit having a switching element for intermittently supplying power from the power source to the solenoid. Thus, the energization current is controlled in a sawtooth shape so that the intermediate value substantially matches the target value.

By the way, the power supply voltage may be greatly consumed and greatly reduced, for example, when the engine is started. And when a power supply voltage falls, according to the correlation shown to Fig.8 (a), the response time for energization amount to reach a target value becomes long. For this reason, the lower the power supply voltage, the fewer times the switching element intermittently connects between the solenoid and the power supply. When the power supply voltage is further lowered, as shown in FIG. 9, the energization control reaches the upper limit value and the energization control is changed from the control of the first constant current I1 to the second constant current I2 without turning off the energization. Will be switched to the control.
For this reason, the lift condition of the needle fluctuates, and as shown in FIG. 8B, the error in the actual injection amount increases as the power supply voltage decreases, and the difference between the target injection amount and the actual injection amount increases. .

[Problems with conventional technology]
For such a divergence between the target injection amount and the actual injection amount, a technique for preventing the divergence between the target injection amount and the actual injection amount by correcting the command value according to the magnitude of the power supply voltage is considered. . However, in order to employ this technique, it is necessary to constantly monitor the power supply voltage, and the power supply voltage must be measured at an extremely high speed. For this reason, the load of the control device is greatly increased. Therefore, since the measurement cycle of the power supply voltage must be increased, the delay is increased and the control response is poor.

As a technique that considers the influence of the power supply voltage on the fuel injection, a technique that prohibits fuel injection and reliably stops the engine when the power supply voltage is smaller than a predetermined threshold is considered (for example, Patent Document 1). reference). However, this technology aims to stop the engine quickly when there is an abnormality in the power supply voltage, and can prevent the difference between the target injection amount and the actual injection amount due to a decrease in the power supply voltage. Can not.
JP-A-1-92544

  The present invention has been made to solve the above-described problems, and prevents a deviation between the target injection amount and the actual injection amount even when the power supply voltage is reduced without increasing the load on the control device. An object of the present invention is to provide a fuel injection device that can perform the above-described operation.

[Means of Claim 1]
According to a first aspect of the present invention, there is provided a fuel injection device according to an electromagnetic actuator that generates a magnetic attractive force by energizing a solenoid, an injector that has a needle that is lifted by the magnetic attractive force to open a nozzle hole, and an operating state of the internal combustion engine. Command value calculating means for calculating a command value for controlling fuel injection by the injector, and energization amount control means for controlling the energization amount to the solenoid to a target value for obtaining a magnetic attraction force of a predetermined strength Power supply voltage measuring means for measuring the voltage of the power supply for supplying power to the solenoid, energization amount target value changing means for changing the target value of the energization amount according to the measured value of the power supply voltage, and the target value of the energization amount Command value correcting means for correcting the command value according to
As a result, even if the power supply voltage decreases, the target value of the energization amount can be changed to a sufficiently low value so that the energization current can be controlled in a sawtooth shape. For this reason, since it is possible to easily maintain a state having a margin with respect to the power supply voltage, it is not necessary to constantly monitor the power supply voltage. Further, even if the lift condition of the needle fluctuates with a decrease in the target value of the energization amount, a deviation between the target injection amount and the actual injection amount can be prevented by correcting the command value. As a result, the difference between the target injection amount and the actual injection amount can be prevented without increasing the load on the control device and constantly monitoring the power supply voltage.

[Means of claim 2]
In the fuel injection device according to claim 2, the measurement cycle of the power supply voltage measuring means is longer than the injection cycle of the injector.
Thereby, the influence on the load of a control apparatus by measurement of a power supply voltage can be reduced significantly.

[Means of claim 3]
In the fuel injection device according to claim 3, at least one of the command values is a command value of an energization start timing corresponding to an injection start timing at which injection is started from the injection hole.

[Means of claim 4]
In the fuel injection device according to claim 4, the power supply voltage is measured by the power supply voltage measuring means before the energization of the solenoid is started.
Thereby, before energization to the solenoid is started, the command value can be corrected by changing the target value of the energization amount. Here, the command value of the energization start time cannot be corrected after the energization start. For this reason, according to this means, the deviation between the target injection amount and the actual injection amount can be prevented by correcting the command value of the energization start timing.

[Means of claim 5]
In the fuel injection device according to claim 5, at least one of the command values is a command value of an energization period corresponding to an injection period in which the injection from the nozzle hole is continued.

[Means of claim 6]
In the fuel injection device according to the sixth aspect, the power supply voltage is measured by the power supply voltage measuring means after the energization of the solenoid is started.
Thereby, after the energization to the solenoid is started, the command value can be corrected by changing the target value of the energization amount. Here, the command value for the energization period can be corrected even after the start of energization. For this reason, according to this means, the deviation between the target injection amount and the actual injection amount can be prevented by correcting the command value of the energization start timing.

[Means of Claim 7]
According to the fuel injection device of the seventh aspect, the predetermined strength of the magnetic attractive force is a strength capable of lifting the needle to a predetermined holding position.
Thereby, the needle can be reliably lifted to a predetermined holding position.

The fuel injection device of the best mode 1 includes an electromagnetic actuator that generates a magnetic attractive force by energizing a solenoid, an injector that has a needle that is lifted by the magnetic attractive force to open a nozzle hole, and an operating state of the internal combustion engine. A command value calculating means for calculating a command value for controlling fuel injection by the injector; an energization amount control means for controlling the energization amount to the solenoid to a target value for obtaining a magnetic attraction force of a predetermined strength; The power supply voltage measuring means for measuring the voltage of the power supply for supplying power to the solenoid, the energization amount target value changing means for changing the target value of the energization amount according to the measured value of the power supply voltage, and the target value of the energization amount And command value correcting means for correcting the command value accordingly.
Further, the measurement cycle of the power supply voltage measuring means is longer than the injection cycle of the injector. Further, at least one of the command values is a command value of the energization start timing corresponding to the injection start timing at which the injection is started from the nozzle hole, and the power supply voltage measuring means measures the power supply voltage when the solenoid is energized. Done before it starts. The magnetic attraction force having a predetermined strength is a strength that can lift the needle to a predetermined holding position.

[Configuration of Example 1]
The configuration of the fuel injection device 1 according to the first embodiment will be described with reference to FIGS. 1 and 2. The fuel injection device 1 is, for example, a device that injects and supplies fuel into each cylinder of a four-cylinder diesel engine (not shown: hereinafter simply referred to as an engine). As shown in FIG. 1, the fuel injection device 1 includes a fuel supply pump 1b that draws fuel from a fuel tank 1a and discharges the fuel at a high pressure, a common rail 1c that accumulates high-pressure fuel at a common rail pressure corresponding to the injection pressure, It is equipped with an injector 2 that is mounted on each cylinder and supplies high-pressure fuel into each cylinder, and a control device 3 that controls the fuel supply pump 1b, the injector 2, and the like.

  The injector 2 is connected to the downstream end of the fuel supply pipe 1d branched from the common rail 1c. The injector 2 includes an injection nozzle 2a that injects high-pressure fuel into the cylinder, and an electromagnetic valve 2b that serves as an electromagnetic actuator that generates a magnetic attractive force by energizing the solenoid 4 (see FIG. 2) to operate the injection nozzle 2a. .

  The injection nozzle 2a is lifted indirectly by a magnetic attractive force to form a needle portion 2d and an injection hole 2c that open the injection hole 2c, and closes the body portion 2e and the injection hole 2c that movably accommodates the needle portion 2d. A nozzle spring 2f for urging the needle portion 2d in the direction is provided. The injection nozzle 2a communicates with the common rail 1c through the fuel supply pipe 1d and the fuel passage 2i, and supplies the common rail pressure through the fuel reservoir 2j and the fuel passage 2k that are maintained at a fuel pressure substantially equal to the common rail pressure. And a control chamber 2n in which the common rail pressure is discharged through the fuel discharge passage 2m.

  The needle portion 2d is separated from and seated on the valve seat 2p formed in the body portion 2e to form a needle 2q that opens and closes the nozzle hole 2c, a control chamber 2n, and receives the fuel pressure in the control chamber 2n in the axial direction. It is comprised by the command piston 2r etc. which move to. Further, the needle 2q and the command piston 2r are connected by a pressure pin 2s and integrally move in the body portion 2e in the axial direction. The pressure pin 2s has a flange 2t to which the nozzle spring 2f is attached.

  The body portion 2e is formed with a fuel reservoir 2j and a fuel passage 2i, a nozzle body 2u for accommodating the needle 2q, a control chamber 2n and a fuel passage 2k, and a nozzle spring 2f and a command piston 2r. The nozzle holder 2v is used. A tip packing 2w is interposed between the nozzle body 2u and the nozzle holder 2v to restrict the movement of the needle portion 2d during the lift. Further, two orifice plates 2x are attached to the nozzle holder 2v on the side opposite to the nozzle body 2u, and the inlet-side orifice 2y for restricting the supply of the common rail pressure to the control chamber 2n and the common rail pressure from the control chamber 2n. An outlet orifice 2z that restricts discharge is formed. The outlet orifice 2z is larger in diameter than the inlet orifice 2y.

  When energization of the solenoid 4 is started and a magnetic attractive force is generated, a valve body (not shown) in the electromagnetic valve 2b is driven to open the fuel discharge path 2m. When the fuel discharge path 2m is opened, the outlet orifice 2z is larger in diameter than the inlet orifice 2y, so that the discharge of the common rail pressure from the control chamber 2n exceeds the supply of the common rail pressure to the control chamber 2n, The fuel pressure in the control chamber 2n decreases. As a result, the urging force due to the fuel pressure in the fuel reservoir 2j becomes larger than the sum of the urging force due to the nozzle spring 2f and the urging force due to the fuel pressure in the control chamber 2n, and the needle 2q is separated from the valve seat 2p and the needle portion. 2d lifts. Thereby, fuel injection starts from the nozzle hole 2c.

  When the energization of the solenoid 4 is stopped and the magnetic attractive force disappears, the valve body is urged by an electromagnetic valve spring (not shown) in the electromagnetic valve 2b to close the fuel discharge path 2m. When the fuel discharge path 2m is closed, the common rail pressure is not discharged from the control chamber 2n, so the fuel pressure in the control chamber 2n stops decreasing and starts to increase. Then, the fuel pressure in the control chamber 2n increases until it becomes equal to the common rail pressure (that is, until it becomes equal to the fuel pressure in the fuel reservoir 2j). As a result, the sum of the urging force caused by the nozzle spring 2f and the urging force caused by the fuel pressure in the control chamber 2n becomes larger than the urging force caused by the fuel pressure in the fuel reservoir 2j, and the needle 2q is seated on the valve seat 2p. Thereby, the fuel injection from the nozzle hole 2c is completed.

  Thus, the electromagnetic valve 2b generates a magnetic attractive force by energizing the solenoid 4, and opens the fuel discharge path 2m by the magnetic attractive force. The electromagnetic valve 2b opens the fuel discharge passage 2m by a magnetic attractive force, thereby indirectly lifting the needle portion 2d (that is, the needle 2q) and opening the nozzle hole 2c. As described above, the electromagnetic valve 2b operates the injection nozzle 2a by generating a magnetic attractive force. Further, the opening degree of the fuel discharge path 2m is a value corresponding to the magnitude of the magnetic attractive force (that is, the energization amount to the solenoid 4), and the holding position and the lift speed of the needle 2q are determined according to this opening degree.

  The energization current to the solenoid 4 changes in the same way as that shown in FIG. 7 in one energization period. That is, at the start of energization, the peak current Ip is energized, thereafter the first constant current I1 lower than the peak current Ip is energized, and thereafter the second constant current I2 lower than the first constant current I1 is energized. Thus, one energization period ends.

  The peak current Ip is energized in order to instantaneously generate a very large magnetic attractive force and to start the lift of the needle 2q. That is, in order to seal the high pressure fuel on the valve body of the electromagnetic valve 2b, an extremely large urging force acts by an electromagnetic valve spring or the like, and in order to start driving the valve body against this urging force, This is because an extremely large magnetic attractive force is required.

The first constant current I1 is energized in order to continuously generate a magnetic attractive force that can lift the needle 2q to a predetermined holding position. For this reason, the first constant current I1 does not require a current as high as the peak current Ip, and is set smaller than the peak current Ip.
The second constant current I2 is energized in order to continuously generate a magnetic attractive force that is strong enough to hold the needle 2q that has stopped lifting at a predetermined holding position. For this reason, the second constant current I2 is set smaller than the first constant current I1 for continuing the lift of the needle 2q.

  As shown in FIG. 2, the control device 3 boosts the voltage of a microcomputer 5 and a power source 6 that perform control processing and arithmetic processing based on signals input from various sensors, stored data, programs, and the like. The high voltage application means 7 for energizing the solenoid 4 with the peak current Ip by discharging the charged high voltage, and the energization amount to the solenoid 4 for the first and second constant currents I1 and I2 The constant current control means 8 for controlling the current, the current detection means 9 for detecting the energization current to the solenoid 4, and the energization to the solenoid 4 from the high voltage applying means 7 or the constant current control means 8 in accordance with a command from the microcomputer 5. The switching element 10 is intermittent.

  The microcomputer 5 calculates a command value for controlling the fuel injection by the injector 2 based on various signals indicating the operating state of the engine in order to cause the injector 2 to inject and supply the target injection amount of fuel. That is, the microcomputer 5 functions as command value calculation means for calculating a command value for controlling fuel injection by the injector 2 in accordance with the operating state of the engine.

  Then, the microcomputer 5 outputs a command signal for performing energization control to the high voltage applying unit 7 and the constant current control unit 8 based on these command values and the target values of the first and second constant currents I1 and I2. In response to a command signal from the microcomputer 5, first, the high voltage applying means 7 energizes the peak current Ip to the solenoid 4, and then the constant current control means 8 sequentially applies the energizing current to the first and second constant currents I1. , I2 is controlled to the target value.

  The constant current control unit 8 compares the current value of the energization amount detected by the current detection unit 9 with the target value of the energization amount commanded from the microcomputer 5 according to the control signal from the comparison circuit 11 and the comparison circuit 11. And a control circuit 13 having a switching element 12 for intermittently supplying power from the power source 6 to the solenoid 4. Thus, the energization current is controlled in a sawtooth shape so that the intermediate value substantially matches the target value, as shown in FIG.

That is, the constant current control means 8 functions as an energization amount control means for controlling the energization amount to the solenoid 4 to a target value for obtaining a magnetic attractive force having a predetermined strength. More specifically, in order to obtain a magnetic attractive force that can lift the needle 2q to a predetermined holding position, the constant current control means 8 sets the energization amount to the solenoid 4 to the target value of the first constant current I1. To control. The constant current control means 8 controls the energization amount of the solenoid 4 to the target value of the second constant current I2 in order to obtain a magnetic attractive force that can hold the needle 2q that has stopped the lift at a predetermined holding position. .
The current detection means 9 is configured as a known current detection circuit incorporating a current detection resistor 14 and the like.

[Features of Example 1]
Features of the fuel injection device 1 according to the first embodiment will be described with reference to FIGS.
The microcomputer 5 according to the first embodiment includes a power supply voltage measuring unit that measures the voltage (power supply voltage) of the power supply 6 that supplies power to the solenoid 4, and an energization amount target that changes the target value of the energization amount in accordance with the measured value of the power supply voltage. It has a function as a value change means and a command value correction means for correcting the command value according to the target value of the energization amount.

  That is, the microcomputer 5 measures the power supply voltage using a signal indicating the power supply voltage detected by the known voltage detecting means 15. Moreover, the measurement cycle of the power supply voltage by the microcomputer 5 is longer than the injection cycle of the injector 2. In addition, the power supply voltage is measured by the microcomputer 5 before the energization of the solenoid 4 is started. Accordingly, the energization of the solenoid 4 is also performed when the target value of the energization amount is changed and the command value is corrected. Done before it starts.

  And the microcomputer 5 changes the target value of the 1st constant current I1 according to the measured value of a power supply voltage, as shown in FIG. That is, when the measured value of the power supply voltage is larger than the threshold value v1, the target value of the first constant current I1 is set to I1a, and when the measured value of the power supply voltage is equal to or less than the threshold value v1 and larger than the threshold value v2, the first constant current I1. Is set to I1b, and the target value of the first constant current I1 is set to I1c when the measured value of the power supply voltage is equal to or less than the threshold value v2 and larger than the threshold value v3. The threshold values v1, v2, v3 and the target values I1a, I1b, I1c of the first constant current I1 are determined based on the lower limit of the variation in the correlation between the power supply voltage and the energization amount in consideration of safety.

  Note that the target value of the first constant current I1 may be changed by a hysteresis method. For example, when the target value of the first constant current I1 is I1b, the target value of the first constant current I1 is changed from I1b only when the measured value of the battery voltage becomes a value larger than the threshold value v1 continuously several times. It may be possible to increase to I1a.

  Further, the microcomputer 5 corrects the command value according to the target value of the first constant current I1. The command value calculated by the microcomputer 5 is an energization start timing command value corresponding to an injection start timing at which injection starts from the nozzle hole 2c, and an energization period command value corresponding to an injection period in which the injection from the nozzle hole 2c continues. is there. Then, as shown in FIG. 4, the microcomputer 5 stores a different correction amount for each target value of the first constant current I1, and corrects the command value using the correction amount according to the target value. The correction amount is set to a larger value as the target value of the first constant current I1 is smaller for both the energization start timing command value and the energization period command value.

[Effect of Example 1]
The microcomputer 5 of the first embodiment measures the power supply voltage, changes the target value of the first constant current I1 according to the measured value, and further sets the energization start timing command value and the energization period command value according to the target value. to correct.
Thereby, the target value of the first constant current I1 can be changed to a low value with a margin with respect to the power supply voltage. For this reason, as shown in FIG. 5, even if the power supply voltage decreases, the first constant current I1 is controlled in a sawtooth shape without increasing the intermittent period. As a result, it is not necessary to constantly monitor the power supply voltage. Furthermore, even if the lift condition of the needle 2q fluctuates as the target value of the first constant current I1 decreases, the difference between the target injection amount and the actual injection amount is corrected by correcting the energization start timing command value and the energization period command value. And the accuracy of the injection start timing can be secured. As described above, even if the load of the control device 3 is increased and the power supply voltage is not constantly monitored, the deviation between the target injection amount and the actual injection amount can be prevented and the accuracy of the injection start timing can be ensured.

Moreover, the measurement cycle of the power supply voltage by the microcomputer 5 is longer than the injection cycle of the injector 2.
Thereby, the influence on the load of the control apparatus 3 by measurement of a power supply voltage can be reduced significantly.

The power supply voltage is measured by the microcomputer 5 before the energization of the solenoid 4 is started.
Thereby, before energization to the solenoid 4 is started, the target value of the first constant current I1 can be changed to correct the energization start timing command value and the energization period command value.

[Modification]
In this embodiment, the energization start timing command value and the energization period command value are corrected according to the target value of the first constant current I1, but when the power supply voltage is measured before the energization start, the corrected command value Even when only the energization start timing command value is set, the deviation between the target injection amount and the actual injection amount can be prevented, and the accuracy of the injection start timing can be ensured. Further, when measuring the power supply voltage after the start of energization, it is possible to prevent a deviation between the target injection amount and the actual injection amount by correcting at least the energization period command value.

  The energization current of the present embodiment has a pattern as shown in FIG. 7, but a pattern in which only the first constant current I1 is energized after the peak current Ip as shown in FIG. The present invention can also be applied to a pattern in which the large first constant current I1 is continuously energized without energizing the peak current Ip and the second constant current is energized thereafter.

  The injector 2 according to the present embodiment indirectly drives (lifts) the needle 2q with a magnetic attraction force, but the present invention is applied to the needle 2q directly driven (lift) with a magnetic attraction force. You can also

It is explanatory drawing which shows the structure of a fuel-injection apparatus (Example). It is explanatory drawing which shows the principal part of a fuel-injection apparatus (Example). It is a correlation diagram which shows the relationship between the measured value of a power supply voltage, and the target value of a 1st constant current (Example). (A) is a correlation diagram showing the relationship between the target value of the first constant current and the correction amount of the energization start timing command value, and (b) is the correction of the target value of the first constant current and the energization period command value. It is a correlation diagram which shows the relationship with quantity (Example). It is a pattern figure which shows transition of an energization current (Example). (A) is a pattern diagram in which only the first constant current is energized after the peak current, and (b) is the first constant current energized without energizing the peak current, and then the second constant current is energized. It is a pattern figure to which it supplies with electricity (modification example). It is a pattern figure which energizes the 1st constant current after the peak current, and energizes the 2nd constant current after that (an example and a conventional example). (A) is a correlation diagram showing the relationship between the power supply voltage and the response time for the energization amount to reach the target value, and (b) is a correlation diagram showing the relationship between the power supply voltage and the error in the actual injection amount. (Conventional example). It is a pattern diagram which shows the change of transition of the energization current accompanying the fall of a power supply voltage (conventional example).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection apparatus 2 Injector 2c Injection hole 2q Needle 5 Microcomputer (command value calculation means, power supply voltage measurement means, energization amount target value change means, command value correction means)
6 Power supply 8 Constant current control means (energization amount control means)

Claims (7)

An electromagnetic actuator that generates a magnetic attractive force by energizing the solenoid, and an injector that has a needle that is lifted by the magnetic attractive force to open the nozzle hole;
Command value calculating means for calculating a command value for controlling fuel injection by the injector according to an operating state of the internal combustion engine;
An energization amount control means for controlling the energization amount to the solenoid to a target value for obtaining a magnetic attraction force of a predetermined strength;
Power supply voltage measuring means for measuring the voltage of a power supply for supplying power to the solenoid;
Energization amount target value changing means for changing the target value of the energization amount according to the measured value of the voltage of the power source;
A fuel injection device comprising command value correcting means for correcting the command value according to the target value of the energization amount. The fuel injection device according to claim 1,
The fuel injection device according to claim 1, wherein a measurement cycle of the power supply voltage measuring means is longer than an injection cycle of the injector. The fuel injection device according to claim 1,
At least one of the command values is a command value of an energization start timing corresponding to an injection start timing at which injection is started from the nozzle hole. The fuel injection device according to claim 3, wherein
The fuel injection device according to claim 1, wherein the power supply voltage is measured by the power supply voltage measuring means before the solenoid is energized. The fuel injection device according to claim 1,
At least one of the command values is a command value for an energization period corresponding to an injection period during which injection from the nozzle holes continues. The fuel injection device according to claim 5, wherein
The fuel injection apparatus according to claim 1, wherein the power supply voltage is measured by the power supply voltage measuring means after energization of the solenoid is started. The fuel injection device according to claim 1,
The fuel injection device according to claim 1, wherein the magnetic attraction force having a predetermined strength is a strength capable of lifting the needle to a predetermined holding position.

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