JP4134120B2 - Fuel injection device - Google Patents

Description

  The present invention relates to a fuel injection device including a fuel injection module that sucks, pressurizes, and injects fuel by a reciprocating motion of a plunger, and particularly stabilizes the fuel injection state in various operating states of an engine to prevent occurrence of malfunction. It relates to technology.

  As an electronically controlled fuel injection device that performs fuel injection by calculating the fuel supply amount according to the engine speed and load, a solenoid coil is energized by a drive signal given from a control unit. A fuel injection module configured to pressurize and inject fuel into the intake manifold by operating the plunger with electromagnetic force generated in the solenoid coil, and then suck the next fuel when the plunger is pushed back by a spring. Has already been proposed (see, for example, Patent Document 1).

  The fuel injection device using the fuel injection module having such a configuration has fewer components compared to a fuel injection device that pressurizes and regulates fuel by a fuel pump and a regulator and injects pressurized fuel from an injector. I'll do it. Also, it is only necessary to output a drive signal and energize the solenoid coil only during both the pressurization stroke for pressurizing the fuel and the injection stroke for injecting the fuel, and no energization is required during the suction stroke for sucking the fuel. Therefore, there is an advantage that the average power consumption is small. For this reason, it is suitably used for a small two-wheeled vehicle with a particularly low capacity of a generator or battery.

  On the other hand, in the conventional fuel injection device, there are synchronous injection in which fuel injection is performed at a predetermined timing in synchronization with engine rotation, and asynchronous injection in which fuel injection is performed asynchronously with engine rotation.

  Here, when the fuel injection module as described above is used as the fuel injection device, when the intake air temperature or the engine temperature is low, the engine load is large, the battery charge amount is small, and the energization amount to the solenoid coil is small. In such a case, the control unit 10 adjusts so that the output time of the drive signal when performing synchronous injection becomes longer. On the other hand, for example, when the opening of the throttle valve suddenly increases due to acceleration, the control unit 10 performs asynchronous injection separately from the synchronous injection so that smooth acceleration can be performed. Supply fuel inside.

  When synchronous injection and asynchronous injection are used together using a fuel injection module, if the timing of asynchronous injection overlaps in the suction stroke of synchronous injection, the fuel injection module will return to pressurization and injection stroke again when the fuel suction is not completed As a result, it becomes impossible to accurately control the fuel injection amount, and the engine rotation becomes unstable.

  As a countermeasure, conventionally, when the start timing of asynchronous injection overlaps the pressurization stroke or injection stroke of synchronous injection, an addition process is performed in which the injection time of asynchronous injection is added after the injection time of synchronous injection. When the start timing of the engine overlaps the suction stroke of the synchronous injection, a technique for delaying the start timing of the asynchronous injection until the synchronous injection suction stroke is completed so that both the synchronous injection and the asynchronous injection are compatible. Has been proposed (see, for example, Patent Document 2).

JP 2001-221137 A JP 2003-206797 A

  However, in the prior art, when synchronous injection is performed independently or when synchronous injection and asynchronous injection are used together, there is no restriction on the output time of the drive signal given to the fuel injection module. Problems (A) to (D) are pointed out.

(A) As described above, when performing synchronous injection, when the intake air temperature or the engine temperature is low, the engine load is large, or when the charge amount of the battery is small and the energization amount to the solenoid coil is small. The control unit 10 adjusts so that the output time of the drive signal becomes long. For example, as shown in FIG. 8A, the output time T1 of the drive signal becomes extremely long without any limitation. When the mutual interval between the drive signals becomes shorter than the time required for fuel suction (hereinafter referred to as fuel suction time T2), as shown in FIG. 8B, the next pressurization is performed when fuel suction is not completed. In order to shift to the injection stroke (portion indicated by the symbol X in FIG. 8B), the fuel injection amount is insufficient.

(B) In order to avoid this problem, for example, as shown in FIG. 8C, if the fuel suction time T2 is always secured after the output time T1 of the drive signal, the following problem is newly created. Arise.

  That is, in a four-cycle engine, if one cycle of crankshaft rotation is TC, a period of one cycle (hereinafter referred to as an engine reference cycle) from the intake stroke to the next intake stroke of the engine is the crankshaft. However, when the sum T1 + T2 of the output time T1 of the drive signal and the fuel suction time T2 becomes longer than the engine reference period 2 · TC, as time elapses, it becomes 2 · TC. The difference of (T1 + T2) −2 · TC is gradually accumulated and the fuel injection timing is gradually delayed, and the fuel injection stroke of the fuel injection module continues even when the intake stroke of the engine is finished and the compression stroke is started. A situation occurs (portion indicated by symbol Y in FIG. 8C). As a result, a variation occurs in the fuel injection amount for each combustion stroke of the engine, causing a problem that the engine rotation becomes unstable.

(C) Further, as described in Patent Document 2 above, when the start timing of asynchronous injection overlaps the pressurization stroke or injection stroke of synchronous injection, the injection time of asynchronous injection is added after the injection time of synchronous injection. When the addition process is performed, when the output time of the drive signal obtained by adding both the synchronous injection time and the asynchronous injection time is long, the state is substantially the same as the state shown in FIG. As shown in FIG. 8B, when the fuel suction is not completed, the process proceeds to the next pressurization and injection stroke (the portion indicated by the symbol X in FIG. 8B), so that the fuel injection amount is insufficient. .

(D) Further, as described in Patent Document 2 described above, when the start timing of asynchronous injection overlaps the suction stroke of synchronous injection, a delay that delays the start timing of asynchronous injection until the suction stroke of synchronous injection is completed. When processing is performed, when the timing of the delayed asynchronous injection overlaps the pressurization stroke or injection stroke of the next synchronous injection (see, for example, FIGS. 9A and 9B), the asynchronous injection is performed at the next synchronous injection injection time. Is added (see FIG. 9C). At this time, if the output time of the drive signal obtained by adding both times becomes longer than the engine reference period 2 · TC, the fuel injection stroke of the fuel injection module is reached even when the intake stroke of the engine ends and shifts to the compression stroke. Will continue to occur and the suction stroke will no longer exist (the portion indicated by Z in FIG. 9C). As a result, a variation occurs in the fuel injection amount for each combustion stroke of the engine, causing a problem that the engine rotation becomes unstable.

  In particular, when asynchronous injection is frequently performed with respect to synchronous injection as shown in FIGS. 10 (a) and 10 (b), as shown in FIG. 10 (c), the amount of fuel injection generated for each combustion stroke of the engine is reduced. The frequency of occurrence of variation increases (the portion indicated by the symbol Z in FIG. 10C), and the engine rotation becomes extremely unstable.

  The present invention has been made in order to solve the above-described problems. By providing a certain limitation on the output period of the drive signal when performing fuel injection using the fuel injection module, the present invention can be used in various operating states of the engine. It is an object of the present invention to provide a fuel injection device capable of maintaining a stable fuel injection state at all times and effectively preventing engine malfunction.

In order to achieve the above object, in the present invention, a fuel injection module that sucks and pressurizes fuel by reciprocating movement of a plunger and injects the fuel and a plunger of the fuel injection module based on an operating state of the engine. A fuel injection apparatus including a control unit that changes an output time of a driving signal to be driven by calculation employs the following configuration.

  In other words, according to the present invention, the control unit is such that the total time required for the pressurization, injection, and suction strokes of the fuel injection module does not exceed a period of one cycle from the suction stroke of the engine to the next suction stroke. As described above, the maximum drive time that is the upper limit of the output time of the drive signal is set.

  According to the present invention, the drive signal is controlled so that the total time required for the pressurization, injection, and suction strokes of the fuel injection module does not exceed a period of one cycle from the suction stroke of the engine to the next suction stroke. Since the maximum drive time that is the upper limit of the output time is set, the fuel injection module can reliably perform fuel suction even in various operating states of the engine, and can always continue stable fuel injection. For this reason, fluctuations in the engine torque are suppressed, and it is possible to effectively prevent malfunctions in the engine rotation.

  In particular, if the maximum drive time is set to a time obtained by subtracting the fuel suction time required for fuel suction of the fuel injection module from the fuel injection interval for the engine, the maximum possible fuel injection time is limited. Therefore, the fuel injection accuracy can be improved and the engine rotation can be prevented from becoming unstable.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram schematically showing a state in which the fuel injection device of the present invention is attached to an engine in the first embodiment.

  In FIG. 1, reference numeral 1 is a four-cycle engine, 2 is an intake air temperature sensor that detects the temperature of intake air of the engine 1, 3 is a throttle valve, 4 is a throttle opening sensor that detects the opening of the throttle valve 3, 5 is an intake pressure sensor that detects the pressure of intake air downstream of the throttle valve 3, 6 is an engine temperature sensor that detects the wall surface temperature of the engine 1, and 7 is a crank that detects the rotational position of a crankshaft (not shown) of the engine 1. An angle sensor, 8 is a fuel injection module, 9 is an ignition coil, and 10 is a control unit.

  The fuel injection module 8 injects fuel into an intake manifold 15 connected to the engine 1. In addition, the control unit 10 calculates an appropriate fuel injection timing and fuel injection amount based on the detection outputs of the sensors 2 and 4 to 7 and outputs a drive signal to the fuel injection module 8. Output an ignition signal.

  Further, 11 is a fuel tank, 12 is a feed pipe for supplying fuel, 13 is a filter provided in the middle of the feed pipe 12, and 14 is a return pipe for returning vapor generated in the fuel injection module 8 to the fuel tank 11. It is.

  In the first embodiment, the fuel injection module 8, the fuel tank 11, and the pipes 12 and 14 constitute a fuel injection device.

  FIG. 2 is a sectional view schematically showing the fuel injection module 8 constituting the fuel injection device.

  In FIG. 2, 81 is a plunger, 82 is a cylinder, 83 is a solenoid coil, 84 is a fuel injection check nozzle, 85 is an orifice nozzle, 86 is a fuel injection port, 87 is a fuel intake check nozzle, 88 is a return check nozzle, 89 is It is a return passage.

  The solenoid coil 83 is energized by a drive signal given from the control unit 10. The fuel suction check nozzle 87 communicates with the feed pipe 12, and one end of the return passage 89 communicates with a part of the side wall of the cylinder 82 via the return check nozzle 88, and the other end communicates with the return pipe 14. Has been.

  The operation of the fuel injection module 8 having the configuration shown in FIG. 2 will be described with reference to the timing chart shown in FIG.

  When energization of the solenoid coil 83 is started by a drive signal given from the control unit 10 (see FIG. 3A), the plunger 81 moves downward in FIG. 2 by the electromagnetic force generated in the solenoid coil 83. In this case, during a period until the plunger 81 reaches the return check nozzle 88 provided on the side wall of the cylinder 82, the vapor in the cylinder 81 passes from the return check nozzle 88 and the return passage 89 via the return pipe 14 to the fuel tank. 11 to reflux.

  Further, when energization to the solenoid coil 83 is continued by the drive signal given from the control unit 10, the plunger 81 continues to move downward and closes the return passage 89 on its side surface, so that the vapor discharge is stopped. At the same time, the fuel in the cylinder 82 is pressurized.

  Here, the time T11 required until the vapor in the cylinder 82 is exhausted to the outside and the fuel in the cylinder 82 is subsequently pressurized becomes the invalid injection time. When the energization of the solenoid coil 83 is continued by the drive signal and the plunger 81 further moves and the pressure in the cylinder 82 exceeds a predetermined value, the pressurized fuel is supplied to the fuel injection check nozzle 84, the orifice nozzle 85, And is injected into the intake manifold 15 through the fuel injection port 86. The time T12 required for this fuel injection is the fuel injection time. A time (= T11 + T12) obtained by combining the invalid injection time T11 and the fuel injection time T12 is the drive signal output time T1.

  When the output time T1 of the drive signal given from the control unit 10 elapses and the energization to the solenoid coil 83 is stopped, the plunger 81 moves upward so as to return to the original position by a return spring (not shown). At that time, the fuel supplied from the fuel tank 11 via the feed pipe 12 passes through the fuel suction check nozzle 87 and is sucked into the cylinder 82. The time required for this fuel suction is the fuel suction time T2. The fuel suction time T2 is substantially the same for both synchronous injection and asynchronous injection.

  When performing synchronous injection, the control unit 10 determines the output period T1 of the drive signal given to the fuel injection module 8 as follows. First, the injection time T12 is determined by adding the correction according to the atmospheric temperature, the intake air temperature, the engine temperature, etc. based on the detection outputs of the sensors 2, 4 to 6 to the basic injection time for determining the basic injection amount, and further, the invalid injection The period T11 is added to obtain an output period (= T11 + T12).

  For example, when the throttle opening degree sensor 4 detects that the opening degree of the throttle valve 3 has increased due to acceleration, the control unit 10 stores a storage device (not shown) so that smooth acceleration can be performed. The injection time T12 is determined by correcting the basic injection time with a predetermined injection interval programmed in advance as in the case of the synchronous injection, and further has an output period (= T11 + T12) including the invalid injection period T11. A drive signal is output.

  In the following description, the output period of the drive signal when performing synchronous injection is referred to as synchronous drive time, and the output period of the drive signal when performing asynchronous injection is referred to as asynchronous drive time. The synchronous drive time is represented by a symbol T1, and the asynchronous drive time is represented by a symbol T3.

  In the first embodiment, the control unit 10 does not set the synchronous drive time T1 when performing synchronous injection and the asynchronous drive time T3 when performing asynchronous injection unconditionally to be long according to the operating state of the engine 1. Rather, a fixed restriction is applied to both times T1 and T3. This point will be described next.

  When performing synchronous injection, the control unit 10 outputs a drive signal to the fuel injection module 8 in synchronization with the rotation of the crankshaft of the engine 1 based on the detection output of the crank angle sensor 7. That is, in the first embodiment, since the engine 1 is a four-cycle type, the drive having the synchronous drive time T1 at a rate of once every two rotations of the crankshaft (that is, every engine reference cycle 2 TC). Output a signal. At this time, the synchronous drive time T1 is limited as follows.

  T1 ≦ 2 · TC-T2 (1)

  That is, when the condition of the expression (1) is satisfied, as shown in FIG. 4A, when performing synchronous injection, the total time T1 + T2 required for the pressurization, injection, and suction processes of the fuel injection module 8 is The period is limited so as not to exceed 2 · TC of one cycle from the suction stroke of the engine to the next suction stroke. As a result, when performing synchronous injection, as shown in FIG. 4B, the fuel suction time T2 is always secured, so the fuel injection module 8 reliably sucks the fuel to be injected next time. It is possible to prevent malfunction of engine rotation due to insufficient fuel injection.

  This is clear from the example shown in FIG. That is, since there is no restriction on the synchronous drive time T1 in the related art, as shown in FIG. 8A, when the synchronous drive time T1 becomes extremely long, as shown in FIG. Since the transition to the next pressurization and injection stroke is performed when the suction is not completed (portion indicated by symbol X in FIG. 8B), the fuel injection amount is insufficient, or the synchronous drive time T1 is equal to the engine reference period 2 · The fuel injection stroke of the fuel injection module 8 is continued even when the intake stroke of the engine ends and shifts to the compression stroke after becoming longer than TC (portion indicated by symbol Y in FIG. 8C). Problems such as variations in fuel injection amount occur during each stroke.

  On the other hand, as shown in FIG. 8D, by setting the synchronous drive time T1 to satisfy the condition of the expression (1), as shown in FIG. Thus, it is possible to reliably suck the fuel to be injected, and to prevent malfunction of the engine rotation due to insufficient fuel injection.

  If the condition such as the expression (1) is satisfied, the fuel injection time T12 is limited and the fuel injection amount does not exceed a certain value. Therefore, correction according to the atmospheric temperature, the intake air temperature, the engine temperature, etc. is added. However, there is no problem in continuing the rotation of the engine 1, and since the fuel injection amount is the same every time, the engine torque does not fluctuate, which is advantageous in preventing malfunction of the engine. is there.

  By the way, in the four-cycle type engine 1, each stroke of intake → compression → expansion → exhaust is completed in two rotations (720 °) of the crankshaft. However, the detection output of the crank angle sensor 7 is every rotation of the crankshaft. Therefore, each stroke cannot be determined based only on the detection output of the crank angle sensor 7. Therefore, in this case, each stroke is determined using the detection output of the intake pressure sensor 5 together. However, each stroke can be specified during a period until the detection output of the intake pressure sensor 5 is stabilized. difficult.

  Therefore, when performing synchronous injection, the synchronous injection is performed every time the detection output of the crank angle sensor 7 is obtained until each stroke of the engine 1 can be determined. That is, the synchronous injection is performed not every 720 ° but every 360 °, that is, every half cycle TC of the engine reference cycle. At this time, the synchronous drive time T1 is limited as follows.

  T1 ≦ TC−T2 (2)

  When the condition of the expression (2) is satisfied, as shown in FIG. 5A, even when the synchronous injection is performed twice in the engine reference period 2 · TC, the pressurization and injection of the fuel injection module 8 are performed. The total time (T1 + T2) required for each suction stroke is limited so as not to exceed a period TC that is half the engine reference period. As a result, when performing synchronous injection, as shown in FIG. 5 (b), the fuel suction time T2 is always ensured within the half cycle TC, so the fuel injection module 8 should inject next time. The fuel can be sucked in reliably, and malfunction of the engine due to insufficient fuel injection can be prevented.

  Even if the synchronous injection is performed twice in the engine reference period 2 · TC as described above, the fuel injected in two separate synchronous injections is taken in at one time in the intake stroke of the engine 1, so that the fuel The injection amount is stable and there is no problem.

  After that, when the detection output of the intake pressure sensor 5 is stabilized and the control unit 10 can discriminate each stroke by using both the detection output of the crank angle sensor 7 and the detection output of the intake pressure sensor 5, the synchronous injection is started. The condition is switched from equation (2) to equation (1). In this way, by switching the conditions, the fuel injection module 8 can reliably perform fuel suction regardless of whether or not the stroke has been determined, and can prevent malfunction of the engine rotation.

  As shown in FIGS. 6A and 6B, when a plurality of asynchronous injections are repeated at a fixed period TD between one synchronous injection and the next synchronous injection, asynchronous driving for each asynchronous injection is performed. Time T3 is limited as follows.

  T3 ≦ TD−T2 (3)

  That is, when the condition of the expression (3) is satisfied, as shown in FIG. 6C, even if the asynchronous injection is repeatedly performed, the fuel suction time T2 is secured each time. It is possible to reliably suck the fuel when asynchronous injection is performed.

  Next, in the case where synchronous injection and asynchronous injection are used in combination, if an output command for an asynchronous injection drive signal is generated before the synchronous drive time T1 and the fuel suction time T2 elapse, the synchronous drive time T1 is reached. A total drive signal is generated by adding the sum ΣT3 of the asynchronous drive time T3. The output time T1 + ΣT3 of the total drive signal at this time is limited as follows.

  T1 + ΣT3 ≦ 2 · TC−T2 (4)

  That is, for example, as shown in FIGS. 7 (a1) and 7 (b1), when the timing of asynchronous injection overlaps the pressurization stroke or injection stroke of the synchronous injection, the addition for adding the asynchronous driving time T3 after the synchronous driving time T1. At this time, as shown in FIG. 7 (c1), the total time T1 + ΣT3 + T2 required for the pressurization, injection, and suction strokes of the fuel injection module 8 does not exceed the engine reference period 2 · TC. Limited to That is, the output time T1 + ΣT3 of the total drive signal obtained by adding the sum ΣT3 of the asynchronous drive time T3 to the synchronous drive time T1 is limited so as to satisfy the condition of the above equation (4). In the example of FIG. 7 (b1), since the number of asynchronous injections within the engine reference period 2 · TC is only one, ΣT3 = T3.

  Further, for example, as shown in FIGS. 7A2 and 7B2, when the timing of asynchronous injection overlaps the suction stroke of synchronous injection, the delay for delaying the start timing of asynchronous injection until the suction stroke of synchronous injection is completed. Processing is performed, and as shown in FIG. 7C2, the asynchronous driving time T3 is added to the synchronous driving time T1 of the next synchronous injection. Even in such a case, the total time T1 + ΣT3 + T2 required for the pressurization, injection, and suction strokes of the fuel injection module 8 is limited so as not to exceed the engine reference period 2 · TC. That is, at the timing of the next synchronous injection, the total drive signal output time T1 + ΣT3 obtained by adding the sum ΣT3 of the asynchronous drive time T3 to the synchronous drive time T1 is limited so as to satisfy the condition of the above equation (4). In the example of FIG. 7 (b2), since the number of asynchronous injections within the engine reference period 2 · TC is only one, ΣT3 = T3.

  As described above, when the condition of the expression (4) is satisfied, even when synchronous injection and asynchronous injection are used together, the total time T1 + ΣT3 + T2 required for the pressurization, injection, and suction strokes of the fuel injection module 8 is the engine reference cycle. Since 2 · TC is not exceeded, as shown in FIGS. 7C1 and 7C2, for example, even when the engine is accelerated, the fuel suction time T2 is always secured. For this reason, the fuel injection module 8 can reliably suck the fuel to be injected next time, and can prevent malfunction of the engine due to insufficient fuel injection.

  This is clear from the example shown in FIG. That is, conventionally, there is no restriction as in the formula (4), and therefore when the synchronous injection and the asynchronous injection are used together, the total time required for the pressurization, injection, and suction strokes of the fuel injection module 8 is T1 + ΣT3 + T2. May be longer than the engine reference cycle 2 · TC, and therefore, the fuel injection stroke of the fuel injection module continues and the suction stroke disappears even when the intake stroke of the engine is finished and the compression stroke is started. (Part indicated by the symbol Z in FIG. 9C). As a result, a variation occurs in the fuel injection amount for each combustion stroke of the engine, causing a problem that the engine rotation becomes unstable.

  On the other hand, as shown in FIG. 9 (d), the total time T1 + ΣT3 + T2 required for the pressurization, injection, and suction strokes of the fuel injection module 8 is limited so as not to be longer than the engine reference period 2 · TC. In other words, by satisfying the condition of the expression (4), as shown in FIG. 9 (e), the fuel injection module 8 can surely suck the fuel to be injected next time, and the fuel injection is insufficient. It is possible to prevent malfunction of the engine rotation due to.

  In particular, even when asynchronous injection is frequently performed with respect to synchronous injection as shown in FIGS. 10 (a) and 10 (b), if the condition of equation (4) is satisfied, FIG. 10 (d), As shown in (e), the fuel injection module 8 can reliably suck the fuel to be injected every engine reference period 2 · TC, and can eliminate variations in the fuel injection amount of the engine.

  As described above, in the first embodiment, the control unit 10 restricts the conditions of the above-described equations (1) to (4) so that all the conditions are satisfied. In the case where synchronous injection and asynchronous injection are used in combination, appropriate fuel injection can always be performed in various operating states of the engine 1. As a result, a stable fuel injection state can be maintained, and the occurrence of malfunction of the engine 1 can be effectively prevented.

  In the first embodiment, the case where the fuel injection is performed for the four-cycle engine 1 has been described as an example. However, the present invention is not limited to this, and the fuel injection is performed for the two-cycle engine. It is also possible to apply it when performing.

In Embodiment 1, it is a block diagram which shows the outline of the state by which the fuel-injection apparatus of this invention was attached to the engine. It is sectional drawing which shows the outline of the fuel-injection module which comprises a fuel-injection apparatus. It is a timing chart with which it uses for the drive signal given from a control unit, and operation | movement description of the fuel-injection module according to this. It is a timing chart with which it uses for description of operation | movement of a fuel-injection module when the drive signal given from a control unit is made to satisfy | fill the conditions of (1) Formula. It is a timing chart with which the drive signal given from a control unit is used for operation | movement description of a fuel-injection module when satisfy | filling the conditions of (2) Formula. It is a timing chart with which the drive signal given from a control unit is used for operation | movement description of a fuel-injection module when satisfy | filling the conditions of (3) Formula. It is a timing chart with which the drive signal given from a control unit is used for description of operation | movement of a fuel-injection module when satisfy | filling the conditions of (4) Formula. 7 is a timing chart showing an example of the operation of the fuel injection module in accordance with the drive signal given from the control unit in the case of performing synchronous injection, comparing the prior art and the present invention. 7 is a timing chart showing an example of the operation of the fuel injection module according to the drive signal given from the control unit in comparison with the present invention when using synchronous injection and asynchronous injection together. 7 is a timing chart showing another example of the operation of the fuel injection module according to the drive signal given from the control unit in comparison with the present invention when using synchronous injection and asynchronous injection together.

Explanation of symbols

1 engine, 8 fuel injection module, 10 control unit,
81 Plunger.

Claims (5)

A fuel injection module that sucks, pressurizes, and injects fuel by reciprocating movement of the plunger; a control unit that changes an output time of a drive signal for driving the plunger of the fuel injection module based on an operating state of the engine; In a fuel injection device comprising:
The control unit controls the drive signal so that the total time required for the pressurization, injection, and suction strokes of the fuel injection module does not exceed a period of one cycle from the intake stroke of the engine to the next intake stroke. A fuel injection device characterized in that a maximum drive time which is an upper limit of the output time is set. 2. The fuel injection device according to claim 1, wherein the maximum drive time is a time obtained by subtracting a fuel suction time required for fuel suction of the fuel injection module from a fuel injection interval for the engine. 2. The maximum drive time is set for at least one of synchronous injection in which fuel is injected in synchronization with engine rotation and asynchronous injection in which fuel is injected asynchronously with engine rotation. Or the fuel-injection apparatus of Claim 2. If an output command for a drive signal of asynchronous injection that injects fuel asynchronously with engine rotation occurs between the start of driving and the completion of driving of synchronous injection that injects fuel in synchronization with engine rotation, synchronous injection 3. The maximum drive time is set to a value obtained by adding an output time of a drive signal for driving and an output time of a drive signal for asynchronous injection. Fuel injectors. 5. When performing synchronous injection for a four-cycle engine, the control unit switches the maximum drive time between when the intake stroke of the engine can be determined and when it cannot be determined. 2. The fuel injection device according to item 1.

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