JP6193141B2 - Fuel injection control device - Google Patents

Description

  The present invention relates to fuel injection control of a vehicle.

  Patent Document 1 discloses control related to fuel injection of a vehicle, and particularly describes a configuration in which the injection amount of an injector is limited by a sub CPU when a failure occurs in a main CPU that performs fuel injection control. In addition, the restriction | limiting of the fuel injection quantity at the time of a failure is required for prevention of the phenomenon called a gas hammer.

  However, if the fuel injection control device includes a plurality of CPUs, the cost increases. In view of this, it is conceivable to realize a monitoring unit that monitors the failure of the CPU that performs fuel injection control with inexpensive hardware (for example, ASIC).

  The CPU or ASIC is usually supplied with, for example, 5V power from a 12V battery via a step-down circuit. When starting an engine using a starter motor, the battery voltage may drop due to the large power consumed by the starter motor at the initial start, and the power supply voltage supplied to the CPU or ASIC may fall below 5V.

  The CPU and ASIC have a reset function that resets the operation once the power supply voltage falls below the operating voltage range. The range of the power supply voltage (hereinafter referred to as the reset voltage range) at which the reset function operates is defined in each CPU and ASIC, but usually the reset voltage ranges of the two are different. For example, the reset voltage range of the CPU is 4.0V to 4.5V, and the reset voltage range of the ASIC is 4.25V to 4.65V. Thus, the reason why the reset voltage ranges of the CPU and ASIC are wide is that the variation of each product is taken into consideration.

  When combining the CPU that performs fuel injection control and the ASIC of the monitoring unit, there is a difference between the reset voltage of the CPU and the reset voltage of the ASIC, so that the ASIC is not operating even though the CPU is operating May occur. For example, if the voltage supplied to the CPU and ASIC drops to 4.1V, the CPU continues to operate if it is above its reset voltage, whereas the ASIC continues to operate. Will be in a state where it is lower than its own reset voltage, which may cause the operation to stop. Therefore, when combining the CPU that performs the fuel injection control and the ASIC of the monitoring unit, it is necessary to perform the fuel injection control in consideration of the situation where the CPU continues to operate and the ASIC is in a reset state.

Japanese Patent No. 3967599

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection control device that can prevent the occurrence of a gas hammer and improve startability by an inexpensive configuration.

  The present invention has the following configuration as one means for achieving the above object.

  According to the invention of claim 1, the first control means (101) for calculating an appropriate fuel injection amount based on information such as the throttle sensor and the engine speed, and the fuel based on an instruction from the first control means Drive means (202) for driving the injection device (201), and signal processing means provided in the second control means (204) for transmitting information indicating the operation of the drive means to the control means as a return signal ( 203), in the fuel injection device for a vehicle in which the reset voltage value of the first control means and the reset voltage value of the second control means are different, the first control means, Monitoring means (113) for monitoring the power supply voltage supplied from the battery (214), and the first control means operates the engine (18) using the battery as a power source in accordance with the operation of the starter switch (102). Control the drive of the starter motor (209) to start When it is detected by the monitoring means that the power supply voltage has fallen below the first voltage (Vth1) corresponding to the reset voltage value of the second control means (S11), after the elapse of a predetermined time, the drive The means stops driving the fuel injection device.

  According to the invention of claim 2, when it is detected that the starter switch is on and the power supply voltage is lower than the first voltage (Vth1) (S11), the first control means, Fuel injection stop control for suppressing the fuel injection amount to the upper limit is executed.

  According to the invention of claim 3, in the fuel injection stop control, it is estimated that the fuel injection amount has not reached the upper limit (S14), communication with the signal processing means is normal (S15), and When the monitoring means detects that the power supply voltage exceeds the second voltage (Vth2> Vth1) (S16), the first control means ends the fuel injection stop control.

  According to the invention of claim 4, in the fuel injection stop control, when it is estimated that the fuel injection amount has reached an upper limit (S14), the first control means is the fuel injection device by the drive means. Is stopped (S18).

  According to the invention of claim 5, the upper limit of the fuel injection amount is determined by the volume of the combustion chamber during the compression stroke of the engine.

  According to the invention of claim 6, in the fuel injection stop control, the first control means sets a fuel injection interval wider than the normal fuel injection interval (S13).

  According to the invention of claim 1, when the engine is started, a predetermined time elapses when the power supply voltage supplied from the battery falls below the first voltage (Vth1) corresponding to the reset voltage of the second control means. After that, since the driving means stops driving the fuel injection device, it is possible to prevent the generation of the gas hammer due to the excessive fuel injection amount.

  According to the invention of claim 2, when the engine is started, when the power supply voltage supplied from the battery falls below the first voltage (VTh1), the fuel injection stop control for suppressing the fuel injection amount to the upper limit is executed. Therefore, generation of a gas hammer due to an excessive fuel injection amount can be prevented.

  According to the invention of claim 3, before the fuel injection amount reaches the upper limit, when communication with the signal processing means is normal and the power supply voltage exceeds the second voltage Vth2 (> Vth1), The engine startability can be improved by terminating the fuel injection stop control.

  According to the inventions of claims 4 and 5, it is possible to prevent the occurrence of a gas hammer due to an excessive fuel injection amount.

  According to the invention of claim 6, a margin can be given to the recovery time of the power supply voltage until the fuel injection is stopped.

The side view of a scooter type motorcycle. The block diagram explaining the fuel-injection control apparatus of an Example, and the surrounding structural example. Explanatory drawing for demonstrating operation | movement of CPU and ASIC when a power supply voltage fall is a short time. Explanatory drawing for demonstrating operation | movement of CPU and ASIC when a power supply voltage fall is a long time. The flowchart explaining the fuel-injection stop control at the time of engine starting of an Example.

  Hereinafter, a fuel injection control device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[Configuration of motorcycle]
FIG. 1 is a right side view of a scooter type motorcycle (hereinafter referred to as a motorcycle) 10 which is a kind of saddle type vehicle. In the following description, the direction of travel of the motorcycle is forward, and reference numerals of the mechanisms and configurations provided symmetrically one by one on the left and right are denoted by “L” indicating left and “R” indicating right.

  The motorcycle 10 includes a body frame 11. The vehicle body frame 11 includes a head pipe 12, a main pipe 13 extending rearward and downward from the head pipe 12, left and right seat rails 14L and 14R extending rearward and obliquely upward from the main pipe 13, and a rear end portion of the main pipe 13. Support frames 15L and 15R are provided that extend rearward and upward and connect to seat rails 14L and 14R.

  The main pipe 13 and the seat rails 14L and 14R constitute a main frame 16. In addition, a pivot plate 17 is suspended from the rear portion of the main pipe 13. Further, an engine 18 is suspended from the main frame 16.

  The head pipe 12 supports a front wheel steering unit 20 including a front wheel 19 so as to be steerable. The front wheel steering unit 20 includes a steering shaft 21 through which the head pipe 12 is inserted, a steering handle 22 attached to the upper end of the steering shaft 21, and a front fork that extends substantially downward from the steering shaft 21 and rotatably supports the front wheel 19. Consists of 23.

  The pivot plate 17 pivotally supports the rear wheel steering unit 25 including the rear wheel 24 so as to be steerable. The rear wheel steering unit 25 includes a pivot shaft 26 that is passed to the pivot plate 17 in the axle direction (left-right direction), a swing arm 27 that extends rearward from the pivot shaft 26 and supports the rear wheel 24, and the swing arm 27 and the seat rail 14L. And rear cushions 28L and 28R passed between 14R.

  A storage box 29 and a fuel tank 30 are sequentially attached to the seat rails 14L and 14R from the front to the rear. A seat 31 on which an occupant sits is attached to the storage box 29 and the fuel tank 30 from above.

  An exhaust pipe 32 extends rearward from a cylinder head (not shown) of the engine 18 and is connected to a silencer 33. Below the engine 18 are provided steps 34L and 34R where a driver who is a passenger puts his / her foot. The support frames 15L and 15R are provided with pillion steps 35L and 35R on which the passengers who are passengers put their feet. A starter motor 209 for starting the engine 18 and a generator (ACG) 212 are attached to the engine 18.

  In the motorcycle 10, the vehicle body frame 11 is covered with a vehicle body cover 36. The vehicle body cover 36 is attached from the front cowl 37, the rear of the front cowl 37, and the main frame cover 38 that covers at least the upper side and the side of the main frame 16 and a part of the main frame cover 38. And a main frame side cover 39 that covers at least the side of the main frame 16.

  A pivot plate cover 40 that covers the side of the pivot plate 17 is provided below the main frame cover 38. The front cowl 37 and the main frame cover 38 constitute a leg shield 41 that covers the front of the driver's feet. The main frame cover 38 has a divided structure of a front cover 42 at the front and a rear cover 43 at the rear.

  A side stand 44 is attached to the pivot plate 17. A front fender 45 is disposed so as to cover the upper and rear sides of the front wheel 19, and a rear fender 46 is disposed so as to cover the upper and rear sides of the rear wheel 24. A license plate 47 is attached to the rear fender 46. A grab rail 48 is provided at the rear of the seat 31.

  A steering wheel cover 49 is attached to the steering handle 22 so as to cover from the periphery, and a headlight 50 is attached to the steering wheel cover 49. Rear confirmation mirrors 51L and 51R are attached to the left and right of the steering handle 22, respectively. Although not shown in FIG. 1, a cylinder lock and a starter switch 102 which are main switches 217 are attached to the steering handle 22.

[Fuel injection control device]
FIG. 2 is a block diagram illustrating a fuel injection control device according to the embodiment and a peripheral configuration example.

  The control unit 101, which is the first control unit, is an electronic control unit (ECU) that is configured by a microcontroller (CPU) and controls each part of the motorcycle 10. The control unit 101 acquires information from each part of the vehicle body including the driver's operation, and controls the operation of the engine 18 and the like based on the acquired information.

The input port of the control unit 101 includes a starter switch 102 operated by a passenger, a throttle valve opening (TH) sensor 103, an intake pressure (negative pressure) (PB) sensor 104, an oil temperature (TO) sensor 105, an outside air temperature ( A TA) sensor 106, an exhaust gas (O ₂ ) sensor 107, a neutral sensor 108, a side stand sensor 109, a crank angle (NE) sensor 110 for detecting the engine speed, and the like are connected.

  A drive circuit 202 that drives an injector 201 that injects fuel is connected to the output port of the control unit 101. The drive circuit 202 has, for example, an open collector (or open drain) configuration, and turns on / off the injector 201 in accordance with a signal input from the control unit 101.

  The signal processing unit 203 performs bidirectional communication with the control unit 101 via a serial peripheral interface (SPI), and returns a return signal indicating the operation of the drive circuit 202 to the control unit 101. The drive circuit 202 and the signal processing unit 203 are integrally configured as an application specific integrated circuit (ASIC) 204 that is a second control unit.

  Further, the output port of the control unit 101 includes a drive circuit 206 for a stepping motor (IACV PM) 205 that opens and closes an idle air amount control valve (IACV), a drive circuit 208 for a fuel pump (FP) 207, and a starter motor (SM). A drive circuit 211 of a starter motor relay 210 that opens and closes an electrical connection between the battery 209 and the battery 214 is connected.

  A generator (ACG) 212 is driven by the engine 26 to generate three-phase AC power. The three-phase AC power output from the ACG 212 is converted into DC power by the regulator 213. The battery 214 is charged with DC power output from the regulator 213.

  The voltage of the battery 214 is supplied to each part of the motorcycle 10 as a 12V power supply via the main switch 217 and is stepped down by the step-down circuit 216, and is supplied to the control unit 101 and the ASIC 204 as a 5V power supply, for example. Although not shown in FIG. 2, 12V power is supplied to the injector 201 and various motors via each drive circuit.

  The fuel injection control device in the embodiment includes a control unit 101, an ASIC 214, and an injector 201. When the main switch 217 is turned on by the occupant, 5V power is supplied to the control unit 101 and the ASIC 214, and the control unit 101 starts various controls and bidirectional communication via SPI between the control unit 101 and the ASIC 214. Is started.

  The control unit 101 includes a reset circuit (RST) 111 that starts the supply of 5V power and the CPU is reset for a predetermined period after the voltage of the 5V power reaches a predetermined value (for example, 4.5V). Further, a watchdog timer (WDT) 112 is provided for resetting the CPU when the CPU performs an abnormal operation. Although not shown in FIG. 2, the ASIC 204 also includes a reset circuit and a WDT. The reset circuit resets the CPU and ASIC even when the voltage of the 5V power supply drops below the specified value, and then resets the CPU and ASIC for a specified period even when the voltage of the 5V power supply reaches the specified value. Maintain state.

  Hereinafter, a fuel injection device in a vehicle in which the reset voltage value of the control unit 101 as the first control unit and the reset voltage value of the ASIC 204 as the second control unit are different will be described.

  For example, a voltage divided from a 12V power source by the voltage divider 215 is input to an analog-digital conversion (ADC) port of the control unit 101. The control unit 101 includes a voltage monitoring unit 113 that monitors the voltage of the 12V power supply according to the input voltage of the ADC port.

  Based on information obtained from various sensors shown in FIG. 2, such as throttle valve opening information obtained from the throttle sensor (TH sensor) 103 and engine speed obtained from the NE center, the control unit 101 determines an appropriate fuel injection amount. Calculate. Then, a fuel injection instruction based on the calculated fuel injection amount is output to the drive circuit 202. Based on the fuel injection instruction, the drive circuit 202 drives the fuel injection device (injector 201), so that an appropriate amount of fuel is supplied to the combustion chamber of the engine 18.

  The signal processing unit 203 transmits information indicating the operation of the drive circuit 202 to the control unit 101 as a return signal via bidirectional communication using SPI. Based on the return signal received from the signal processing unit 203, the control unit 101 can determine whether or not the drive circuit 202 is performing fuel injection according to the fuel injection instruction.

● Fuel injection stop control at engine start First, when the occupant turns on the main switch 217, 12V power is supplied to each part of the fuel injection control device, the operation of the fuel injection control device is started, and the fuel pump 207 is driven. Be started.

  Next, when the occupant presses the starter switch 102 (the starter switch 102 is turned on), the starter motor relay 210 is turned on, power is supplied to the starter motor 209, current flows to the starter motor 209, and the starter motor 209 Rotate. At this time, the voltage of the 12V power supply is reduced by a large current flowing through the starter motor 209. When the occupant releases the starter switch 102 (the starter switch 102 is turned off), the starter motor relay 210 is turned off, the power supply to the starter motor 209 is cut off, and the voltage of the 12V power supply almost returns to the terminal voltage of the battery 214. To do.

  FIG. 3 is an explanatory diagram for explaining the operation of the CPU (control unit 101) and the ASIC in the present invention. In FIG. 3, the 12V power source indicates a voltage obtained by regulating the power generated by the ACG 212 by the regulator 213, and the 5V power source is the controller 101 and the ASIC 204 when the 12V power source is decompressed via the step-down circuit 216. Indicates the voltage of the power supplied to.

  Hereinafter, the operation in FIG. 3 will be described. When the main switch 217 is turned on by an occupant (rider) finger operation (t1), the 12V power supply gradually increases from the 0V state and eventually reaches 12V. When the voltage of the 12V power supply increases to the value of Vth1 (t2), the fuel pump 207 is driven by the drive circuit 208 according to a command from the control unit 101. Thereafter, appropriate power is supplied to the control unit 101 and the ASIC 204, and the operation can be performed.

  Thereafter, when the control unit 101 detects that the starter switch 102 has been pressed by the occupant (t3), the control unit 101 operates the starter motor 209 via the drive circuit 211 and the starter motor relay 210, thereby Crank. When the temperature of the engine 18 is low, since the viscous resistance in the lubrication system in the engine 18 is high, the power consumed in the starter motor 209 increases, and the power supply voltage in the 5V power supply decreases as the 12V power supply voltage drops. May descend. This voltage drop can also occur when the capacity of the battery 214 is low.

  When the voltage drop of the 12V power supply reaches Vth1 (threshold) (t4), the control unit 101 is operating, while the ASIC 204 is determined to be below the reset voltage and not operating. Therefore, the control unit 101 stops the injector drive when a predetermined time (hereinafter, time limit) T has elapsed from time t4. In the example shown in FIG. 3, before the time limit T elapses, the voltage of the 12V power source exceeds Vth2 (threshold), and the ASIC 204 returns to the operating state (t5). In this case, the injector drive is not stopped. Details of the threshold voltages Vth1 and Vth2 will be described later.

  FIG. 4 is an explanatory diagram for explaining the operation of the CPU (control unit 101) and the ASIC in the present invention. Similar to FIG. 3, in FIG. 4, the 12V power supply indicates the voltage that is generated by the ACG 212 and is regulated by the regulator 213, and the 5V power supply is reduced in voltage through the step-down circuit 216. The voltage of the power supplied to the control unit 101 and the ASIC 204 is shown.

  Hereinafter, the operation in FIG. 4 will be described. When the main switch 217 is turned on by an occupant (rider) finger operation (t1), the 12V power supply gradually increases from the 0V state and eventually reaches 12V. When the voltage of the 12V power supply increases to the value of Vth1 (t2), the fuel pump 207 is driven by the drive circuit 208 according to a command from the control unit 101. Thereafter, appropriate power is supplied to the control unit 101 and the ASIC 204, and the operation can be performed.

  Thereafter, when the control unit 101 detects that the starter switch 102 has been pressed by the occupant (t3), the control unit 101 operates the starter motor 209 via the drive circuit 211 and the starter motor relay 210, thereby Crank. When the temperature of the engine 18 is low or the capacity of the battery 214 is reduced, as described above, the power supply voltage in the 5V power supply may drop as the 12V power supply voltage drops.

  When the voltage drop of the 12V power supply reaches Vth1 (threshold) (t4), the control unit 101 is operating, while the ASIC 204 is determined to be below the reset voltage and not operating. Therefore, the control unit 101 stops the injector drive when the time limit T has elapsed from the time t4. In the example shown in FIG. 4, since the time limit T elapses (t6) before the voltage of the 12V power source exceeds Vth2 (threshold), the injector drive is stopped. In this case, the occupant is informed of the necessity of maintenance of the motorcycle by, for example, blinking a warning light arranged in the vicinity of the steering handle 22.

  Thus, when the control unit 101 starts the engine 18 and monitors the power supply voltage of the 12V power supply by the power supply monitoring unit 113 and detects a voltage drop of the 12V power supply below the threshold voltage Vth1, the ASIC 204 becomes inoperative. Judge that bi-directional communication via SPI stops. When the injector drive time exceeds the limit time T, it is determined that the fuel injection amount has reached the upper limit with respect to the volume of the combustion chamber of the engine 18, and fuel injection is stopped.

  As described above, in the example shown in FIG. 3, the voltage drop of the 12V power supply is short (less than the limit time T), and the ASIC 204 returns to the operating state before it is determined that the fuel injection amount has reached the upper limit. This is an example in which bidirectional communication via SPI is restored. Therefore, the engine 18 can be started without stopping fuel injection. On the other hand, in the example shown in FIG. 4, the voltage drop of the 12V power supply is long (limit time T or more), and it is determined that the fuel injection amount has reached the upper limit before bidirectional communication via SPI is recovered. This is an example in which the injection is stopped.

  FIG. 5 is a flowchart for explaining the fuel injection stop control at the time of starting the engine according to the embodiment. This process is executed by the control unit 101 when the starter switch 102 is turned on (t3).

  The control unit 101 determines whether the voltage of the 12V power supply is less than the threshold voltage Vth1 by the voltage monitoring unit 113 (S11). If the voltage of the 12V power supply is equal to or higher than the threshold voltage Vth1, it is determined whether or not the starter switch 102 is on (S12) .If it is on, the process returns to step S11, and if it is off, the fuel injection is not stopped. The fuel injection stop control is terminated (corresponding to normal engine start).

  When the voltage of the 12V power supply is less than the threshold voltage Vth1 in step S11, the control unit 101 starts measuring the time related to the time limit T and sets a fuel injection thinning mode in which the fuel injection interval is wider than the normal fuel injection interval. (S13). Then, it is determined whether or not the fuel injection amount has reached the upper limit depending on whether or not the time limit T has elapsed (S14). As described above, when the voltage of the 12V power supply is detected to be less than the threshold voltage Vth1, the fuel injection stop control is started on the assumption that the ASIC 204 becomes inoperative regardless of the state of bidirectional communication via the SPI. .

  When the time limit T has not elapsed and it is determined that the fuel injection amount has not reached the upper limit, the control unit 101 determines whether bidirectional communication via SPI is normal (S15), and the voltage of the 12V power supply Is determined whether or not exceeds the threshold voltage Vth2 (S16). That is, when the bidirectional communication is normal and the voltage of the 12V power supply exceeds the threshold voltage Vth2, the control unit 101 cancels the fuel injection thinning mode without stopping the fuel injection (S17), and performs the fuel injection stop control. Is finished (corresponding to FIG. 3). Further, when a communication error is detected in the bidirectional communication or the voltage of the 12V power source is equal to or lower than the threshold voltage Vth2, the control unit 101 returns the process to step S14 and continues the fuel injection stop control.

  If it is determined in step S14 that the time limit T has elapsed and the fuel injection amount has reached the upper limit, the control unit 101 stops fuel injection (stops driving of the fuel injection device) (S18), and requires maintenance. The fuel injection stop control is finished (corresponding to FIG. 4).

  The two threshold voltages have a relationship of Vth1 <Vth2. The threshold voltage Vth1 is set to a voltage of a 12V power supply (for example, 6V) at which the output voltage of the step-down circuit 216 is less than 5V. Alternatively, the threshold voltage Vth1 is set to a 12V power supply voltage (in other words, a voltage corresponding to the reset voltage) at which the output voltage of the step-down circuit 216 becomes the reset voltage of the ASIC 204. As the reset voltage used for setting the threshold voltage Vth1, it is preferable to employ a voltage that is higher than the maximum value of the reset voltage of the ASIC 204 and close to the maximum value. For example, in the above example (the reset voltage range of the ASIC 204 is 4.0 V to 4.5 V), the voltage of the 12 V power source at which the output voltage of the step-down circuit 216 is 4.6 V is set as the threshold voltage Vth1.

  On the other hand, the threshold voltage Vth2 may be set to a voltage of a 12V power supply (hereinafter referred to as an operation guarantee voltage) in which the output voltage 5V of the step-down circuit 216 is guaranteed. However, considering the voltage fluctuation of the 12V power supply shown in FIG. Set the voltage higher than the guaranteed operating voltage (for example, 8V). However, if the threshold voltage Vth2 is set high, there is a high probability that fuel injection will stop, so the difference voltage Vth2-Vth1 is preferably not so large.

  The setting of the fuel injection thinning mode in step S13 can give a margin for the recovery time of the voltage of the 12V power source until the fuel injection is stopped, but is not essential. Further, the determination order of the bidirectional communication determination in step S15 and the determination of the power supply voltage in step S16 may be reversed.

  In the above, the example in which the fuel injection is stopped when the time limit T has elapsed when the relationship between the time and the fuel injection amount is clear has been described. However, the fuel injection amount is estimated from the number of times the injector is driven and the fuel injection is stopped May be.

  Thus, when the signal processing unit 203 of the ASIC 204 becomes inoperative due to the voltage drop of the 12V power supply at the time of engine start and bi-directional communication via the SPI stops, the fuel injection amount with respect to the volume of the combustion chamber of the engine 18 is reduced. Based on this, the fuel injection is stopped. Therefore, when the signal processing unit 203 of the ASIC 204 returns to the operating state in a short time and bi-directional communication via the SPI is restored, the engine 18 can be started without stopping fuel injection. it can. In addition, when the voltage drop of the 12V power source becomes long, fuel injection can be stopped to prevent the occurrence of a gas hammer.

  As is clear from the above description, the voltage drop of the 12V power supply is short (less than the limit time T) is the extent to which the signal processing unit 203 of the ASIC 204 returns from the operating state before the fuel injection amount reaches the upper limit. Is the time. Further, the voltage drop of the 12V power supply for a long time (limit time T or longer) is a time that the fuel injection amount reaches the upper limit before the signal processing unit 203 of the ASIC 204 returns to the operating state.

Claims (6)

First control means (101) for calculating an appropriate fuel injection amount based on information such as the throttle sensor and engine speed,
Driving means (202) for driving the fuel injection device (201) based on an instruction of the first control means;
Provided in the second control means (204), comprising signal processing means (203) for transmitting information indicating the operation of the drive means to the control means as a return signal,
In the fuel injection device for a vehicle in which the reset voltage value of the first control means and the reset voltage value of the second control means are different from each other,
The first control means has monitoring means (113) for monitoring the power supply voltage supplied from the battery (214),
The first control means controls driving of a starter motor (209) for starting the engine (18) using the battery as a power source according to an operation of a starter switch (102), and the power supply voltage is controlled by the monitoring means. Is detected to be below the first voltage (Vth1) corresponding to the reset voltage of the second control means (S11), after a predetermined time (T) has elapsed, the fuel injection to the drive means A fuel injection device that stops driving the device.   When it is detected that the starter switch is turned on and the power supply voltage is lower than the first voltage (Vth1) (S11), the first control means suppresses the fuel injection amount to the upper limit. 2. The fuel injection device according to claim 1, wherein fuel injection stop control is executed.   In the fuel injection stop control, it is estimated that the fuel injection amount has not reached the upper limit (S14), communication with the signal processing means is normal (S15), and the power supply voltage is 3. The fuel injection device according to claim 2, wherein when it is detected that a voltage Vth2 (> Vth1) of 2 is exceeded (S16), the first control means ends the fuel injection stop control.   In the fuel injection stop control, when it is estimated that the fuel injection amount has reached the upper limit (S14), the first control unit stops driving the fuel injection device by the drive unit (S18). The fuel injection device according to claim 2 or claim 3.   5. The fuel injection device according to claim 2, wherein an upper limit of the fuel injection amount is determined by a volume of a combustion chamber during a compression stroke of the engine.   In the fuel injection stop control, the first control means sets a fuel injection interval wider than a normal fuel injection interval (S13). The fuel according to any one of claims 2 to 5 Injection device.

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