JP2002161787A - Fuel injection device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen the region capable of ensuring the linearity of fuel injection pulse width with injected fuel amount in a fuel injection device using a fuel injection valve provided with a couple of magnetomotive forces (coils). SOLUTION: In the fuel injection device which has a control coil 28 through which a current is carried at opening of a valve and a holding coil 29 through which the current is carried during holding of the valve opening and performs the fuel injection using the magnetomotive forces generated by the above coils, a basic current-carrying period in the control coil 28 is corrected to be shortened in a small injection amount region in which the basic current-carrying period in the control coil which is set for valve opening operation is equal to the basic fuel injection pulse width set based on the operation condition of the engine, and then the delay of valve opening start in the small injection amount region is made to be equal to that in a large injection amount region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved technique for a fuel injection device for an internal combustion engine using a fuel injection valve having two coils and opening and closing the valve by energizing the two coils.

[0002]

2. Description of the Related Art In recent years, it has become possible to use a battery power source as a drive power source without separately providing a booster circuit, thereby enabling high-fuel-pressure fuel injection required for a direct injection engine in a cylinder due to demands for low cost and low power consumption. There are known fuel injection valves having two magnetomotive forces. For example, JP-A-11-1484
No. 39 discloses a resistance that generates a magnetomotive force at the start of valve opening,
It has a control coil set to have a small inductance and a hold coil having a relatively high resistance value that generates a magnetomotive force when the valve is held open. When the control coil is energized, a current rises at a large time change rate with respect to the hold coil. It discloses that a required magnetomotive force is generated with good response, and the hold coil generates a required minimum magnetomotive force by suppressing a current value.

[0003] During the energization period (valve opening pulse width) to the control coil of the fuel injection valve, an optimum magnetomotive force can be obtained with respect to normal fuel pressure (fuel pressure), drive power supply voltage (applied voltage) and circuit resistance. As described above, the correction is set according to the fuel pressure and the drive power supply voltage at that time. For example, when the fuel pressure is higher than normal or when the drive power supply voltage decreases, the valve opening rising characteristics equivalent to the normal case (bounce of the valve element due to collision with the stopper converges to a completely open state) Since the magnetomotive force required to secure the valve opening convergence up to this point increases, the correction is made so as to be longer (larger) than in the normal case.

[0004]

As shown in FIG. 10, in a low pulse region before the fuel injection pulse Ti and the injection flow rate Q have linearity, first, the response delay until the injection signal and the valve start to open. And an unstable region until the rebound due to the collision of the valve body with the stopper converges.

[0005] Further, in the in-cylinder direct injection engine, it is necessary to reduce the ineffective region and the unstable region as much as possible in order to achieve a balance between output and fuel efficiency. Therefore, it is necessary to increase the magnetomotive force from the start of valve opening until the valve is stabilized. In the conventional fuel injection valve having two magnetomotive forces, the magnetomotive force at the time of valve opening is controlled by an energizing period to the control coil. The energizing period is determined by the fuel pressure and the power supply voltage as described above. . Then, in order to reduce the invalid area and the unstable area,
Since the energization period to the control coil is set longer than necessary for a stable region having linearity, in the low fuel injection amount region in the stable region, the set valve opening pulse width and the fuel In some cases, the injection pulse widths are substantially equal.

As shown in FIG. 11, in the high fuel injection region where the set valve opening pulse width Tc is smaller than the fuel injection pulse width Ti, the valve is kept open, that is, the hold coil 2
The valve is closed from the state of energization to 9 (shown by a solid line in the figure). In this case, since the value of the current flowing through the hold coil 29 is small (the attraction force is also small), the magnetomotive force (attraction force) falls short after the end of energization, and the time from the end of energization to the start of the valve closing operation is short.

On the other hand, in the low fuel injection region where the valve opening pulse width Tc is equal to the fuel injection pulse width Ti (Tc ≒ Ti), the energization of the control coil 28 is terminated together with the fuel injection pulse end timing (valve closing command). The current value to the control coil 28 is large (the attraction force is also large)
The valve is closed from the state. For this reason, as shown in FIG.
In the low fuel injection amount region, the time Ts ′ (valve closing start delay) from the valve closing command to the start of the valve closing operation becomes larger than Ts in the high fuel injection amount region, and the fuel injection amount is expected. (The linearity of the injected fuel amount with respect to the fuel injection pulse width is lost).

In view of the above, the present invention has been made in view of the above-mentioned problems, and it is possible to accurately inject a required amount of fuel in the low fuel injection amount region, and thus to obtain a fuel injection amount having a linearity. It is an object of the present invention to provide a fuel injection device for an internal combustion engine that can expand a region to a low fuel injection amount side.

[0009]

According to a first aspect of the present invention, there is provided a control coil which is energized at the initial stage of valve opening and a hold coil which is energized at the time of holding the valve open. In a fuel injection device for an internal combustion engine in which fuel is injected by a fuel injection valve that opens and closes by a magnetomotive force, immediately after the behavior of the fuel injection valve is stabilized, basic energization of a control coil set for valve opening operation is performed. In the low fuel injection amount region where the period is equivalent to the basic fuel injection pulse width set based on the operating state of the engine, and in the region where the basic fuel injection pulse width is sufficiently long with respect to the energizing period to the control coil. The current supply period to the control coil is shortened and corrected so that the valve closing start delay time is equal to the valve closing start delay.

[0010] The invention according to claim 2 is characterized in that the basic energizing period to the control coil is set after being corrected according to the fuel pressure supplied to the fuel injection valve.
The invention according to claim 3 is characterized in that the basic energizing period to the control coil is set after being corrected according to the voltage applied to the control coil.

According to a fourth aspect of the present invention, the control coil is supplied to the control coil in a low fuel injection region in which a basic energizing period to the control coil is equal to a basic fuel injection pulse width set based on an operating state of the engine. The basic fuel injection pulse width is shortened and corrected such that the valve closing start delay time is equivalent to the valve closing start delay in a region where the basic fuel injection pulse width is sufficiently long with respect to the energization period.

According to a fifth aspect of the present invention, the control coil is supplied to the control coil in a low fuel injection region in which a basic energizing period to the control coil is equal to a basic fuel injection pulse width set based on an operating state of the engine. Is corrected so as to be smaller than the basic fuel injection pulse width by a predetermined amount.

According to a sixth aspect of the present invention, the end of energization of the control coil is determined by the time from the end of energization of the control coil to the end of the fuel injection pulse until the current flowing through the hold coil is saturated. It is characterized in that it is made earlier.

[0014]

According to the first aspect of the present invention, the basic energization period to the control coil set for the valve opening operation is equal to the basic fuel injection pulse width set based on the operating state of the engine. By shortening and correcting the basic energization period to the control coil in the low fuel injection amount region, the linearity of the injected fuel amount with respect to the fuel injection pulse width can be secured as a valve closing start delay equivalent to the high fuel injection amount region. The area can be enlarged.

According to the second aspect of the present invention, the basic energization period for the control coil is set after being corrected in accordance with the fuel pressure supplied to the fuel injection valve. As a result, the accuracy of the fuel injection amount is improved, and the area in which the linearity can be ensured is further expanded. According to the third aspect of the present invention, the basic energization period for the control coil is set in accordance with the voltage applied to the control coil, or is set in combination with the correction in accordance with the fuel pressure. The valve opening convergence is also ensured as good as possible, the accuracy of the fuel injection amount is improved, and the area where the linearity can be ensured is further expanded.

According to the fourth aspect of the invention, in the low fuel injection amount region where the current value at the end of energization is large and the time from the end of energization to the start of valve closing (valve closing start delay) is long, Since the injection signal (fuel injection pulse width) is shortened and corrected by the length of the injection signal, the energization of the control coil for valve opening operation is terminated at the end of the injection signal. And the area where the linearity can be secured can be expanded.

According to the fifth aspect of the invention, in the low fuel injection amount region where the current value at the end of energization is large and the time from the end of energization to the start of valve closing (valve closing start delay) is long,
Since the basic energization period to the control coil set for the valve opening operation is shortened and corrected by the longer time, the valve closing start delay can be made the same as the high fuel injection amount area, and the area where the linearity can be secured is expanded. it can.

According to the sixth aspect of the present invention, the end of energization to the control coil set for the valve opening operation is determined by:
The valve is always closed from the energized state (saturated current value) to the hold coil by increasing the time from the end of energization to the control coil to the saturation of the current value flowing through the hold coil after the end of the fuel injection pulse. Therefore, the time from the valve closing start command to the start of the valve closing operation can always be kept constant, and the area where the linearity can be secured can be expanded.

[0019]

Embodiments of the present invention will be described below. In FIG. 1, an engine 1 is provided with an electromagnetic fuel injection valve (injector) 2 facing a combustion chamber 3 of each cylinder of the engine, and an intake port 4 and an intake valve 5 are provided.
Fuel is injected from the injector 2 with respect to the air sucked in through the air to form an air-fuel mixture. The air-fuel mixture is compressed in the combustion chamber 3 and ignited by spark ignition by a spark plug 6.

The exhaust gas of the engine 1 is discharged from the combustion chamber 3 through an exhaust port 7 and an exhaust valve 8, and is discharged into the atmosphere through an exhaust purification catalyst and a muffler (not shown). The fuel is supplied to the injector 2 from a fuel supply system (not shown) at a controlled fuel pressure (fuel supply pressure) according to the operating state, and the ECU (engine control unit) 20 controls the injection timing and injection amount to inject fuel. Supply.

The ECU 20 has a built-in microcomputer, calculates a fuel injection pulse width based on various input detection signals, and outputs the result as an injection signal. Where E
Various detection signals input to the CU 20 include an intake air amount signal Q from the air flow meter 11, a crank angle signal from the crank angle sensor 12, an engine coolant temperature signal Tw from the water temperature sensor 13, and a signal from the voltmeter 14. There are a battery voltage signal, a fuel pressure signal from the fuel pressure sensor 15, an accelerator opening signal Acc, and the like, and the engine speed Ne is calculated from the crank angle signal.

Next, a fuel injection device according to one embodiment of the present invention is shown in FIG. The fuel injection device includes an injector 2, an ECU 20, an injector control circuit 21, and a battery 22, as shown in FIG. The injector 2 opens and closes a fuel passage between a ball valve 24 attached to the tip of a valve body (plunger) 23 and a seat 25, and controls the amount of fuel injected from a fuel injection hole by the opening time.

The plunger 23 includes a return spring 26
Thus, the ball valve 24 is pressurized so as to be pressed against the seat 25. A control coil 28 and a hold coil 29 that generate a magnetomotive force when energized are provided in the injector main body 27, and have a circuit configuration as shown in FIG. 2B.

The control coil 28 has a resistance,
Since both the inductances are set to be small, the current rises at a time change rate larger than that of the hold coil 29, so that the required magnetomotive force can be generated with good response. The hold coil 29 is for generating a magnetomotive force for maintaining the valve open state, and is set to have a relatively high resistance since it is sufficient to generate a minimum necessary magnetomotive force while suppressing the current value.

A battery voltage is supplied to the injector control circuit 21, and energization control of the control coil 28 and the hold coil 29 is performed by turning on / off the drive FETs 30 and 31 based on an injection signal from the ECU 20. Next, the opening / closing valve operation of the injector 2 will be described. In response to the injection signal from the ECU 20, both the drive FET 30 on the control coil 28 side and the drive FET 31 on the hold coil 29 side are turned on from the start of valve opening. Here, as described above, since the hold coil 29 has a large resistance value, no current flows through the hold coil 29.

Therefore, at the initial stage of valve opening, only the control coil 28 is energized to generate a magnetomotive force (attraction force), and the attraction force required to hold the valve body (the attraction force to overcome the return spring 26 and the fuel pressure) and Then, plunger 23
(And the ball valve 24 attached to the tip thereof) is driven in a direction away from the seat 25 to open the valve. After the valve is opened, the drive FET 30 on the control coil 28 side is turned off, the hold coil 29 is energized, and the valve is kept open by the generated magnetomotive force.

Here, as shown in FIG. 2C, a diode 32 for preventing reverse current may be added downstream of the hold coil 29. By doing so, the back electromotive force generated on the hold coil 29 side by ON / OFF of the drive FET 30 on the control coil 28 side can be suppressed. Then, the drive FET 31 on the side of the hold coil 29 is turned off, and the energization of the hold coil 29 is terminated.
When the suction force is lower than the suction force required for holding the valve body, the ball valve 24 is pressed against the seat 25 via the plunger 23 to close the valve.

The power supply period to the control coil 28 is set after being corrected according to the fuel pressure supplied to the fuel injection valve and the applied voltage (drive voltage) applied to the control coil 28. Next, control according to the present invention will be described. FIG. 3 shows a first embodiment of the present invention (broken lines indicate conventional control).

This is because Tc ≒ just after the valve behavior is stabilized.
The correction is performed such that the basic fuel injection pulse width Ti set in accordance with the required fuel injection amount in the low fuel injection region where Ti is set is reduced by a predetermined amount. Specifically, in the region where the basic fuel injection pulse width Ti is sufficiently long, the low fuel injection region where Tc ≒ Ti is satisfied with respect to the time from the saturation of the current of the hold coil to the end of energization and the start of valve closing. Since the time from the end of energization to the start of valve closing is extended under the influence of the current of the control coil, the extended amount is set as the correction amount Tsh, and the basic fuel injection pulse width Ti is reduced by Tsh.

The correction amount Tsh is calculated as follows. In the conventional control state, the valve closing start delay time is the longest when Ti = Tc (when Ti <Tc, the energization of the control coil ends in synchronization with Ti, so that actually Ti = Tc). First, a time Ts' from the energized state of the control coil to the start of valve closing at this time (the maximum valve closing delay time at Tc).
Is calculated.

The attraction force at which valve closing starts is determined by the fuel pressure and the set load of the return spring, and the attraction force of the coil is determined by the flowing current I and the number of turns N of the coil. The time from the end of energization to the start of valve closing can be calculated from the current value at the end of energization and the time constant of the coil, but the current value at the end of energization is determined by the energization period to the control coil and the battery voltage. The time Ts 'from the end of energization to the start of valve closing is given as a map MTS' reference value based on the energization period Tc to the control coil and the battery voltage VB. In addition, when the fuel pressure is variable, the simplest is to use this map as the high-side MTS'HI and the low-side MTS'L
Two surfaces of O are prepared, and reference values of high pressure and low pressure are obtained by linear interpolation (see FIG. 9A).

Next, with respect to the Tc, the basic fuel injection pulse width Ti is sufficiently long with respect to the energizing time Tc to the control coil, and the energization is terminated when the current value of the hold coil is saturated, and valve closing is started. The minimum basic fuel injection pulse width Ti that results in the same valve closing delay time as the delay time Ts
Calculate s. Since Tis is determined using Tc as a parameter, in the actual control, a map MTI using the control coil energization period Tc and the battery voltage VB as the timing, similarly to the valve closing start delay time Ts' from the end of the control coil energization period. Given by reference. Further, when the fuel pressure is made variable similarly to the valve closing start delay Ts' from the end of the control coil energizing period, the map is most simply described by using the high-pressure side MISTHI and the low-pressure side MDIS.
Two surfaces of the LO are prepared, and reference values for the high and low pressures are obtained by linear interpolation (see FIG. 9B).

Here, the basic fuel injection pulse width Ti is sufficiently long with respect to the power supply period Tc to the control coil.
Compared to the case where the energization is terminated from the state where the hold coil current is saturated and the valve closing is started, the valve closing start delay time is extended when the basic fuel injection pulse width Ti is Ti <Tis, and the correction at this time is performed. The value Tsh is: Tsh = (Ts−Ts ′) × (Ti−Tc) / (Tis
−Tc).

Then, the corrected fuel injection pulse width Ti 'is set by adding the correction amount Tsh (Tsh <0) to the basic fuel injection pulse width Ti. As described above, even in the low fuel injection amount region immediately after the valve behavior becomes stable when Tc ≒ Ti, the valve closing start delay with respect to the valve closing start command timing of the fuel injection valve can be made equal to the high fuel injection amount region. Expand the area where linearity can be secured while reducing the unstable area.

FIG. 6 is a flowchart showing the control according to the first embodiment. In step 101, the operation state, fuel pressure, and drive voltage are read. In step 102, the basic fuel injection pulse width Ti is calculated based on the required fuel injection amount. In step 103, a basic valve-opening pulse width for the valve-opening operation (a period during which the control coil is energized) Tc is calculated.

In step 104, referring to the map MTS'HI (LO) based on the drive voltage read in step 101 and the basic valve opening pulse width Tc calculated in step 103, the valve is closed by terminating the control coil. Is determined (see FIG. 9A).
In step 105, as in step 104, the map MTISHI (L) is obtained from the drive voltage read in step 101 and the basic valve opening pulse width Tc calculated in step 103.
O), the basic fuel injection pulse width Ti is sufficiently long with respect to the energization period Tc to the control coil, and the delay time Ts when the energization is terminated and the valve closing is started when the current value of the hold coil is saturated. The minimum basic fuel injection pulse width Tis that results in the same valve closing start delay time as in (1) is calculated (see FIG. 9B).

In step 106, if the basic fuel injection pulse width Ti calculated in step 102 is Ti <Tis, the process proceeds to step 107, and if Ti ≧ Tis, the process ends without performing this control. In step 107, a correction value Tsh is calculated. In step 108, the corrected fuel injection pulse width Ti '(= T) is obtained by adding the correction amount Tsh (Tsh <0) to the basic fuel injection pulse width Ti.
i + Tsh) and stores it as the fuel injection signal Ti.

At step 109, the stored fuel injection signal Ti is output. Next, FIG. 4 shows a second embodiment of the control according to the present invention (dashed lines indicate conventional control). This is because, as in the first embodiment, T
In the low fuel injection amount region where c ≒ Ti, the basic valve opening pulse width Tc set according to the battery voltage and the fuel pressure is shortened.

Specifically, in the first embodiment, the basic fuel injection pulse width Ti is reduced by the correction amount Tsh, whereas in the present embodiment, the basic valve opening pulse width Tc is reduced by the correction amount Tsh. This correction amount Tsh is calculated as follows. The process until the maximum valve closing delay time Ts' at Tc is obtained is the same as in the first embodiment.

Next, with respect to the Tc, the basic fuel injection pulse width Ti is sufficiently long with respect to the energizing time Tc to the control coil, and the energization is completed and the valve is closed when the current value of the hold coil is saturated. Then, the maximum basic valve opening pulse width Tcs which becomes the same valve closing delay time as the delay time Ts is calculated. Since Tcs is determined using Ti as a parameter, in actual control, Tcs is given with reference to a map MTCS on the basis of the basic valve opening pulse width Ti and the battery voltage VB. Further, when the fuel pressure is made variable similarly to the control coil energization period end and the valve closing start delay, the simplest is to use this map as the high-pressure side MTCSHI and the low-pressure side MTCSHI.
Two surfaces of the CSLO are prepared, and reference values for the high and low pressures are obtained by linear interpolation (see FIG. 9C).

Here, the basic fuel injection pulse width Ti is sufficiently long with respect to the power supply period Tc to the control coil.
Compared to the case where the energization is terminated from the state where the hold coil current is saturated and the valve closing is started, the valve closing start delay time is extended when the basic valve opening pulse width Tc is Tc> Tcs.
The correction value Tsh at this time is: Tsh = (Ts−Ts ′) × (Ti−Tc) / (Ti−
Tcs).

The correction amount T is added to the basic valve opening pulse width Tc.
The fuel injection pulse width Tc ′ after correction is set by adding sh (Tsh <0). As described above, even in the low fuel injection amount region immediately after the valve behavior becomes stable where Tc ≒ Ti, the valve closing start delay with respect to the valve closing start command timing of the fuel injection valve can be made equal to the high fuel injection amount region. Expand the area where linearity can be secured while reducing the unstable behavior area.

FIG. 7 is a flowchart showing the control according to the second embodiment. Step 201 to Step 2
Steps up to step 04 are the same as steps 101 to 104 in the first embodiment. In step 205, as in step 204, the basic fuel injection pulse width Ti is applied to the control coil by referring to the map MTCSHI (LO) from the drive voltage read in step 201 and the basic fuel injection pulse width Ti calculated in step 202. A maximum valve-opening pulse width Tcs that is sufficiently longer than the period Tc and has the same valve-closing start delay time Ts as the delay time Ts in the case where the current supply to the hold coil is saturated and the valve closing is started after the current value is saturated. (See FIG. 9C).

In step 206, if the basic valve opening pulse width Tc calculated in step 202 is Tc> Tcs, the process proceeds to step 207, and if Tc ≦ Tcs, the process is terminated without performing this control. In step 207, the correction amount Ts
h is calculated. In step 208, the corrected valve opening pulse width Tc '(= Tc + Tsh) is obtained by adding the correction amount Tsh (Tsh <0) to the basic valve opening pulse width Tc.
And stored as the valve opening signal Tc.

In step 209, the stored valve opening signal Tc is output. FIG. 5 shows a third embodiment of the control according to the present invention. Like the second embodiment, the basic valve opening pulse width Tc is shown in FIG.
And the basic fuel injection pulse width Ti is the basic valve opening pulse width Tc.
Is shortened so that the valve closing start delay time is equivalent to the valve closing start delay time Ts when it is sufficiently long.

Specifically, when the basic fuel injection pulse width Ti obtained in the first embodiment is sufficiently longer than the valve opening pulse width Tc, the minimum valve closing start delay time Ts becomes the same as the valve closing start delay time Ts. Is the correction amount Tsh (= Tis−Tc> 0), and the difference between the basic fuel injection pulse width Ti and the correction amount Tsh is the valve opening pulse width Tc ′. '.

Thus, as in the first and second embodiments, even in the low fuel injection amount region immediately after the valve behavior becomes stable where Tc ≒ Ti, the closing of the fuel injection valve with respect to the valve closing start command timing is started. The delay can be made equal to the high fuel injection amount region, and the region where linearity can be ensured while the valve behavior unstable region is reduced is expanded. The valve is closed from the state where the current flowing through the hold coil is always saturated.

FIG. 8 is a flowchart showing the control according to the third embodiment. Step 301 to step 3
The steps up to 03 are the same as in the first and second embodiments. In step 304, step 10 in the first embodiment is performed.
Similarly to 5, the basic fuel injection pulse width Ti is determined based on the drive voltage read in step 301 and the basic valve opening pulse width Tc calculated in step 303 with reference to the map MISTHI (LO) with respect to the power supply period Tc to the control coil. The minimum basic fuel injection pulse width T that is sufficiently long and has the same valve closing start delay time Ts as the delay time Ts when power is turned off from the state where the current value of the hold coil is saturated and valve closing is started.
is is calculated (see FIG. 9B).

In step 305, as in step 106, the basic fuel injection pulse width T calculated in step 302
When i is Ti <Tis, the process proceeds to step 306, where Ti
If ≧ Tis, the process ends without performing this control. In step 306, a correction amount Tsh is calculated. Step 30
7, the corrected valve opening pulse width Tc ″ (= Ti−Ts)
h) is calculated and stored as the valve opening signal Tc.

At step 308, the stored valve opening signal Tc is output.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of the present invention.

FIG. 2 is a diagram showing a fuel injection control device.

FIG. 3 is a diagram showing a state of energizing a control coil and a hold coil in the control according to the first embodiment.

FIG. 4 is a diagram showing a state of energizing a control coil and a hold coil in the control according to the second embodiment.

FIG. 5 is a diagram showing a state in which a control coil and a hold coil are energized in the control according to the third embodiment.

FIG. 6 is a flowchart showing control according to the first embodiment.

FIG. 7 is a flowchart showing control according to the second embodiment.

FIG. 8 is a flowchart showing control according to the third embodiment.

FIG. 9 is a map for referencing a time Ts ′ from the end of energization to the start of valve closing, which is also used for control, and FIG.
The figure which shows the reference map and the maximum basic valve-opening pulse width Tcs reference map which becomes the same valve closing start delay time as (C) Ts.

FIG. 10 is a diagram showing a relationship between a fuel injection pulse width Ti and an injection flow rate Q.

FIG. 11 is a diagram showing a state in which a control coil and a hold coil are energized by conventional control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Fuel injection valve 20 ... ECU 21 ... Injector control circuit 22 ... Battery 23 ... Plunger 24 ... Ball valve 26 ... Return spring 27 ... Injector main body 28 ... Control coil 29 ... Hold coil

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 51/06 F02M 51/06 MF Term (Reference) 3G066 AA02 AB02 AD12 BA51 CC06U CC14 CC15 CC24 CE25 3G084 BA13 EA08 EA11 EC05 FA00 3G301 JA14 LB01 LC10 MA11 NA08 NB06 NC02 PA01Z PB08Z PE03Z PE08Z PF03Z PG01Z

Claims (6)

[Claims] A control coil that is energized at an initial stage of opening the valve and a hold coil that is energized when the valve is held open;
In a fuel injection device for an internal combustion engine that performs fuel injection by a fuel injection valve that opens and closes by a magnetomotive force generated by the two coils, immediately after the behavior of the fuel injection valve is stabilized, the fuel injection device is set for a valve opening operation. In the low fuel injection amount region in which the basic energizing period to the control coil is equal to the basic fuel injection pulse width set based on the operating state of the engine, the basic fuel injection pulse is applied to the energizing period to the control coil. A fuel injection device for an internal combustion engine, wherein a basic energization period to the control coil is shortened and corrected so as to have a valve closing start delay time equivalent to a valve closing start delay in a region where the width is sufficiently long. 2. A combustion injection device for an internal combustion engine according to claim 1, wherein the basic energization period for said control coil is set after being corrected according to the fuel pressure supplied to a fuel injection valve. . 3. The internal combustion engine according to claim 1, wherein the basic energization period for the control coil is set after being corrected in accordance with a voltage applied to the control coil. Fuel injection device. 4. A low fuel injection region in which a basic energizing period to the control coil is equal to a basic fuel injection pulse width set based on an operation state of the engine, and wherein the control coil is energized with respect to the energizing period. 4. The basic fuel injection pulse width is shortened and corrected so that the valve closing start delay time is equivalent to the valve closing start delay time in a region where the basic fuel injection pulse width is sufficiently long. A fuel injection device for an internal combustion engine according to any one of the preceding claims. 5. The pulse width of an electric current supplied to the control coil is set in a low fuel injection region in which a basic energization period to the control coil is equal to a basic fuel injection pulse width set based on an operation state of an engine. The fuel injection device for an internal combustion engine according to any one of claims 1 to 3, wherein the correction is performed so as to be smaller than the basic fuel injection pulse width by a predetermined amount. 6. An end time of energization of the control coil is set to be earlier than an end time of energization of the control coil from an end time of the basic fuel injection pulse by at least a time until a current value flowing to the hold coil is saturated. The fuel injection device for an internal combustion engine according to any one of claims 1 to 3, wherein: