Engine control device

Abstract

To provide an engine control device that reduces the likelihood of starting failures. [Solution] The control device controls an engine that includes a shut-off valve provided in the fuel passage connecting the fuel tank and the fuel injection valve, a starter motor used to start the engine, and a battery that supplies power to the shut-off valve and the starter motor. The control device performs drive control of the starter motor and opening and closing control of the shut-off valve. After the starter motor starts to drive (step S2), the control device performs control to open the shut-off valve when a predetermined valve opening condition is met (step S4: YES) (step S6).

Description

Technical Field

[0001] This invention relates to an engine control device.

Background Art

[0002] Conventionally, as an engine control device, there is known one that controls a shut-off valve provided in a fuel passage connecting a fuel tank and a fuel injection valve. In the engine control device of Patent Document 1, the shut-off valve is closed during engine stoppage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the engine control device as described above, it is necessary to open the shut-off valve when starting the engine. At this time, depending on the timing between driving the starter motor of the engine and controlling to open the shut-off valve, the engine may not be started normally and the start may fail.

Means for Solving the Problems

[0005] Hereinafter, the means for solving the above problems and its operational effects will be described. The engine control device for solving the above problems is an engine control device for controlling an engine that includes a shut-off valve provided in a fuel passage connecting a fuel tank and a fuel injection valve, a starter motor used to start the engine, and a battery that supplies power to the shut-off valve and the starter motor, and comprises a processing circuit that performs drive control of the starter motor and opening and closing control of the shut-off valve, the gist of which is that the processing circuit performs control to open the shut-off valve after the start of the starter motor's operation, triggered by the fulfillment of predetermined opening conditions. [Effects of the Invention]

[0006] With the above configuration, startup failures become less likely. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing the configuration of one embodiment of an engine and an engine control device. [Figure 2] Figure 2 is a flowchart showing the engine starting process. [Figure 3] Figure 3 is a timing chart showing the time-series changes of (a) CPU startup, (b) starter motor drive, (c) first shut-off valve opening request, (d) second shut-off valve opening request, (e) engine speed, and (f) battery voltage when starting the engine. [Figure 4] Figure 4 is a flowchart showing the startup process in the second embodiment. [Figure 5] Figure 5 is a timing chart showing the time-series changes of (a) CPU startup, (b) starter motor drive, (c) first shut-off valve opening request, (d) second shut-off valve opening request, (e) engine speed, and (f) battery voltage when starting the engine in the second or third embodiment. [Figure 6] Figure 6 is a flowchart showing the startup process in the third embodiment. [Modes for carrying out the invention]

[0008] (First Embodiment) The first embodiment of the engine control device will be described below with reference to Figures 1 to 3. <Configuration of the engine and engine control system> The engine 10 shown in Figure 1 is installed in a vehicle. The fuel for the engine 10 is a gaseous fuel. An example of a gaseous fuel is hydrogen gas.

[0009] The engine 10 comprises a main body 11. In Figure 1, the multiple cylinders and multiple spark plugs of the main body 11 are not shown. The main body 11 generates power to move the vehicle by burning fuel injected from multiple fuel injectors 13 inside each cylinder.

[0010] The engine 10 includes a fuel tank 12, a plurality of fuel injectors 13, a fuel passage 14, a first shut-off valve 19 and a second shut-off valve 20, a first pressure sensor 23 and a second pressure sensor 24. The fuel tank 12 stores gaseous fuel. The gaseous fuel is stored in the fuel tank 12 in a compressed state. Each fuel injector 13 is supplied with gaseous fuel from the fuel tank 12. Each cylinder is provided with one fuel injector 13. The fuel injectors 13 supply fuel into the cylinder.

[0011] The fuel passage 14 connects the fuel tank 12 to each fuel injector 13. The fuel passage 14 consists of a fuel pipe 17 connected to the fuel tank 12 and a delivery pipe 18 connecting the fuel pipe 17 to each fuel injector 13. The fuel stored in the fuel tank 12 is supplied to each fuel injector 13 via the fuel pipe 17 and the delivery pipe 18.

[0012] The first shut-off valve 19 and the second shut-off valve 20 are located in the fuel passage 14. Each shut-off valve 19, 20 is, for example, a solenoid valve. Each shut-off valve 19, 20 is switched between an open state and a closed state by opening and closing control by the control device 100. Each shut-off valve 19, 20 becomes open when it receives an open command from the control device 100. Each shut-off valve 19, 20 becomes closed when it receives a close command from the control device 100. Specifically, when an open command is input from the control device 100 to the drive circuit of each shut-off valve 19, 20, the drive circuit supplies power to the shut-off valve 19, 20. As a result, the shut-off valve 19, 20 becomes open. When a close command is input from the control device 100 to the drive circuit of each shut-off valve 19, 20, the drive circuit stops supplying power to the shut-off valve 19, 20. As a result, the shut-off valve 19, 20 becomes closed. The first shut-off valve 19 and the second shut-off valve 20 are kept open while the engine 10 is running. The first shut-off valve 19 and the second shut-off valve 20 are kept closed when the engine 10 is stopped.

[0013] The first shut-off valve 19 is located in the fuel passage 14 near the outlet of the fuel tank 12. The first shut-off valve 19 is located at the end of the fuel piping 17 that is on the fuel tank 12 side. When the first shut-off valve 19 is open, fuel is supplied from the fuel tank 12 to the fuel piping 17. When the first shut-off valve 19 is closed, the fuel supply from the fuel tank 12 to the fuel piping 17 is stopped.

[0014] The second shut-off valve 20 is located downstream of the first shut-off valve 19 in the fuel passage 14. The second shut-off valve 20 is located in the fuel piping 17, close to the delivery pipe 18. When the second shut-off valve 20 is open, fuel is supplied to the delivery pipe 18 through the fuel piping 17. When the second shut-off valve 20 is closed, the fuel supply to the delivery pipe 18 through the fuel piping 17 is stopped.

[0015] A pressure reducing valve 21 is positioned between the first shut-off valve 19 and the second shut-off valve 20 of the fuel passage 14. The pressure reducing valve 21 regulates the pressure of the fuel flowing from the high-pressure fuel tank 12 into the delivery pipe 18.

[0016] A relief valve 28 is disposed between the pressure reducing valve 21 and the second shut-off valve 20 in the fuel passage 14. When the pressure in the fuel pipe 17 becomes a certain level or higher, the relief valve 28 discharges the fuel in the fuel pipe 17 to the outside of the fuel pipe 17.

[0017] The first pressure sensor 23 and the second pressure sensor 24 detect the passage fuel pressure, which is the pressure of the fuel in the fuel passage 14. Each pressure sensor 23, 24 outputs a detection signal regarding the detected passage fuel pressure to the control device 100.

[0018] The first pressure sensor 23 is disposed between the first shut-off valve 19 and the second shut-off valve 20 in the fuel passage 14. The first pressure sensor 23 detects a first passage fuel pressure indicating the passage fuel pressure between the first shut-off valve 19 and the second shut-off valve 20. The first passage fuel pressure corresponds to the pressure of the fuel in the fuel pipe 17. The second pressure sensor 24 is disposed between the second shut-off valve 20 and the fuel injection valve 13. The second pressure sensor 24 detects a second passage fuel pressure indicating the passage fuel pressure between the second shut-off valve 20 and the fuel injection valve 13. The second passage fuel pressure corresponds to the pressure of the fuel in the delivery pipe 18.

[0019] The engine 10 includes a first temperature sensor 26 and a second temperature sensor 27. Each temperature sensor 26, 27 detects the passage fuel temperature, which is the temperature of the fuel in the fuel passage 14. Each temperature sensor 26, 27 outputs a detection signal regarding the detected passage fuel temperature to the control device 100.

[0020] The first temperature sensor 26 is positioned between the first shut-off valve 19 and the pressure reducing valve 21. The first temperature sensor 26 detects the first passage fuel temperature, which indicates the passage fuel temperature between the first shut-off valve 19 and the pressure reducing valve 21. The first passage fuel temperature corresponds to the fuel temperature in the portion of the fuel piping 17 upstream of the pressure reducing valve 21. The second temperature sensor 27 is positioned between the second shut-off valve 20 and the fuel injection valve 13. The second temperature sensor 27 detects the second passage fuel temperature, which indicates the passage fuel temperature between the second shut-off valve 20 and the fuel injection valve 13. The second passage fuel temperature corresponds to the fuel temperature in the delivery pipe 18.

[0021] The control device 100 performs various controls on the engine 10 by controlling various control targets, including the fuel injection valve 13, the first shut-off valve 19, the second shut-off valve 20, and the pressure reducing valve 21. For example, the control device 100 drives the shut-off valves 19 and 20 to open by sending an open signal to them, and drives the shut-off valves 19 and 20 to close by sending a close signal to them.

[0022] The control device 100 includes a CPU 110 and a memory 120 composed of ROM and RAM. The CPU 110 executes programs stored in the memory 120, thereby performing various controls by the control device 100. In this embodiment, the CPU 110 corresponds to a processing circuit.

[0023] The control device 100 is connected to the battery 200, starter motor 300, ignition switch 400, coolant temperature sensor 500, and ambient temperature sensor 600. The starter motor 300 starts the engine 10 by receiving power from the battery 200. The operation state of the ignition switch 400 is input to the control device 100, which detects whether the vehicle driver has requested to start or stop the engine 10. In other words, when the ignition switch 400 is turned ON, the control device 100 determines that there is a request to start the engine 10, and when the ignition switch 400 is turned OFF, the control device 100 determines that there is a request to stop the engine 10. The coolant temperature sensor 500 detects the temperature of the coolant (not shown) used to cool the engine 10. The coolant temperature sensor 500 outputs a detection signal related to the detected water temperature to the control device 100. The ambient temperature sensor 600 detects the ambient temperature. The ambient temperature sensor 600 outputs a detection signal related to the detected ambient temperature to the control device 100.

[0024] The control device 100 acquires various values ​​necessary for controlling the engine 10. For example, the control device 100 acquires detection signals from pressure sensors 23, 24, temperature sensors 26, 27, ignition switch 400, coolant temperature sensor 500, and outside temperature sensor 600.

[0025] <Startup process> The control device 100 performs a starting process to start the engine 10. The control device 100 performs the starting process when the ignition switch 400 is turned ON.

[0026] As shown in Figure 2, during the startup process, the control device 100 starts the CPU 110 (step S1). Subsequently, the control device 100 performs drive control to start the drive of the starter motor 300 (step S2).

[0027] Subsequently, the control device 100 determines the valve opening waiting time, which is the waiting time until the first shut-off valve 19 and the second shut-off valve 20 are opened (step S3). As an example, the control device 100 determines the valve opening waiting time according to the passage fuel temperature detected by the temperature sensors 26 and 27. Specifically, the control device 100 determines the valve opening waiting time according to the passage fuel temperature detected by either of the temperature sensors 26 or 27. For example, if the passage fuel temperature is low, the control device 100 determines a longer valve opening waiting time compared to when the passage fuel temperature is high. Also as an example, the control device 100 determines the valve opening waiting time according to the coolant temperature detected by the coolant temperature sensor 500. Specifically, if the coolant temperature is low, the control device 100 determines a longer valve opening waiting time compared to when the coolant temperature is high. Also as an example, the control device 100 determines the valve opening waiting time according to the ambient temperature detected by the ambient temperature sensor 600. Specifically, the control device 100 determines a longer valve opening waiting time when the outside temperature is low compared to when the outside temperature is high.

[0028] Next, the control device 100 determines whether the determined valve opening waiting time has elapsed (step S4). If the valve opening waiting time has not elapsed (step S4: NO), the control device 100 waits for a certain period of time (step S5) and then returns to the process in step S4. Thus, the control device 100 waits until the valve opening waiting time has elapsed.

[0029] If the valve opening waiting time has elapsed (Step S4: YES), the control device 100 opens the first shut-off valve 19 and the second shut-off valve 20 (Step S6). In this embodiment, the elapsed valve opening waiting time corresponds to the fulfillment of the valve opening condition. That is, the control device 100 opens the first shut-off valve 19 and the second shut-off valve 20 when the valve opening condition is met by the elapsed valve opening waiting time. After that, the control device 100 starts fuel injection control and ignition control (Step S7) and finishes the starting process.

[0030] Fuel injection control is the control of each fuel injection valve 13 to inject fuel into each cylinder. Ignition control is the control of each spark plug to ignite the fuel-air mixture in each cylinder. <Operation of the First Embodiment> As shown in Figure 3, in the starting process described above, the control device 100 starts driving the starter motor 300 and then opens the first shut-off valve 19 and the second shut-off valve 20 after waiting for predetermined valve opening conditions to be met. In other words, in this embodiment, the start of driving the starter motor 300 and the opening of the first shut-off valve 19 and the second shut-off valve 20 do not occur simultaneously.

[0031] Specifically, as shown in Figure 3(a), when the ignition switch 400 is turned ON, the CPU 110 starts up (time t1). As shown in Figure 3(b), after the CPU 110 starts up, the starter motor 300 is then driven (time t2). As a result, as shown in Figure 3(e), the engine speed begins to increase. At this time, as shown in Figure 3(f), the voltage of the battery 200 decreases due to the start of the starter motor 300. Then, as shown in Figures 3(c) and 3(d), the first shut-off valve 19 and the second shut-off valve 20 open after a waiting time has elapsed since the start of the starter motor 300 (time t3). During this time, as shown in Figure 3(f), the voltage of the battery 200, which decreased due to the start of the starter motor 300, recovers over time. This allows the first shut-off valve 19 and the second shut-off valve 20 to be opened during the starting process, avoiding the period when the battery voltage drops significantly due to the start of the starter motor 300's operation.

[0032] Furthermore, the voltage required to open the first shut-off valve 19 and the second shut-off valve 20 varies depending on the temperature of the engine 10 and the fuel. Here, the control device 100 determines the valve opening waiting time according to the detection results of the temperature sensors 26, 27, the coolant temperature sensor 500, and the ambient temperature sensor 600. In other words, the control device 100 can determine an appropriate time to restore the voltage of the battery 200 according to the temperature of the engine 10 and the fuel.

[0033] <Effects of the First Embodiment> (1-1) In the starting process, the first shut-off valve 19 and the second shut-off valve 20 cannot be opened due to the drop in battery voltage caused by the start of the starter motor 300. As a result, starting failures are less likely to occur.

[0034] (1-2) In the starting process, time is provided to allow the battery 200 voltage to recover between the start of the starter motor 300 and the opening of the first shut-off valve 19 and the second shut-off valve 20. This allows the first shut-off valve 19 and the second shut-off valve 20 to open after the battery 200 voltage has started to recover.

[0035] (1-3) In the starting process, the control device 100 can determine an appropriate valve opening waiting time for the voltage of the battery 200 to recover to the voltage necessary to open the first shut-off valve 19 and the second shut-off valve 20. This further suppresses the inability to open the first shut-off valve 19 and the second shut-off valve 20 due to a drop in the voltage of the battery 200.

[0036] (Second Embodiment) Next, a second embodiment of the engine control device will be described with reference to Figures 4 and 5.

[0037] <Startup process in the second embodiment> As shown in Figure 4, during the startup process, the control device 100 starts the CPU 110 in the same manner as in the first embodiment (step S11) and also starts driving the starter motor 300 (step S12).

[0038] Subsequently, the control device 100 determines a first valve opening waiting time, which is the waiting time until the second shut-off valve 20 is opened (step S13). In this embodiment, the first valve opening waiting time corresponds to the first waiting time. As an example, the control device 100 determines the first valve opening waiting time according to the detection results of the temperature sensors 26, 27, the cooling water temperature sensor 500, and the ambient temperature sensor 600, similar to when determining the valve opening waiting time in the first embodiment.

[0039] Next, the control device 100 determines whether the determined first valve opening waiting time has elapsed (step S14). If the first valve opening waiting time has not elapsed (step S14: NO), the control device 100 waits for a certain period of time (step S15) and then returns to the process in step S14. As a result, the control device 100 waits until the first valve opening waiting time has elapsed. On the other hand, if the first valve opening waiting time has elapsed (step S14: YES), the control device 100 opens the second shut-off valve 20 (step S16).

[0040] After opening the second shut-off valve 20, the control device 100 determines a second valve opening waiting time, which is the waiting time until the first shut-off valve 19 is opened (step S17). In this embodiment, the second valve opening waiting time corresponds to the second waiting time. As an example, the control device 100 determines the second valve opening waiting time according to the detection results of the temperature sensors 26, 27, the cooling water temperature sensor 500, and the ambient temperature sensor 600, similar to when determining the valve opening waiting time in the first embodiment.

[0041] Next, the control device 100 determines whether the determined second valve opening waiting time has elapsed (step S18). If the second valve opening waiting time has not elapsed (step S18: NO), the control device 100 waits for a certain period of time (step S19) and then returns to the process in step S18. As a result, the control device 100 waits until the second valve opening waiting time has elapsed. On the other hand, if the second valve opening waiting time has elapsed (step S18: YES), the control device 100 opens the first shut-off valve 19 (step S20). After that, the control device 100 starts fuel injection control and ignition control (step S21) and finishes the starting process.

[0042] <Operation of the second embodiment> As shown in Figure 5, in the starting process described above, the control device 100 starts driving the starter motor 300, and then opens the first shut-off valve 19 and the second shut-off valve 20 at different timings. In other words, in this embodiment, the start of driving the starter motor 300, the opening of the first shut-off valve 19, and the opening of the second shut-off valve 20 do not occur simultaneously.

[0043] Specifically, as shown in Figure 5(a), when the ignition switch 400 is turned ON, the CPU 110 starts up (time t11). As shown in Figure 5(b), after the CPU 110 starts up, the starter motor 300 is then driven (time t12). As a result, as shown in Figure 5(e), the engine speed begins to increase. At this time, as shown in Figure 5(f), the voltage of the battery 200 decreases due to the start of the starter motor 300. Then, as shown in Figure 5(c), the second shut-off valve 20 opens after the first valve opening waiting time has elapsed since the start of the starter motor 300 (time t13). Also, as shown in Figure 5(d), the first shut-off valve 19 opens after the second valve opening waiting time has elapsed since the second shut-off valve 20 opened (time t14). During this time, as shown in Figure 3(f), the voltage of the battery 200 recovers over time. As a result, during the starting process, the first shut-off valve 19 and the second shut-off valve 20 can be opened sequentially as the voltage of the battery 200, which has decreased due to the start of the starter motor 300, recovers.

[0044] <Effects of the second embodiment> (2-1) The voltage of the battery 200 required to open the first shut-off valve 19 or the second shut-off valve 20 individually is lower than the voltage of the battery 200 required to open both simultaneously. Therefore, in this embodiment, it is possible to prevent the first shut-off valve 19 and the second shut-off valve 20 from being unable to be opened during the starting process. Consequently, starting failures become less likely.

[0045] (2-2) In this embodiment, by opening the first shut-off valve 19 and the second shut-off valve 20 at different timings, the first shut-off valve 19 and the second shut-off valve 20 can be opened at a voltage lower than the voltage required to open both simultaneously. As a result, compared to the case where the first shut-off valve 19 and the second shut-off valve 20 are opened simultaneously, the time until the first shut-off valve 19 and the second shut-off valve 20 are opened can be shortened, and the engine 10 can be started quickly.

[0046] (2-3) The pressure in the fuel piping 17 is higher upstream of the pressure reducing valve 21 than downstream of the pressure reducing valve 21. Here, the first shut-off valve 19 is located upstream of the pressure reducing valve 21, and the second shut-off valve 20 is located downstream of the pressure reducing valve 21. The voltage required to open each shut-off valve 19, 20 is higher as the pressure applied to the shut-off valves 19, 20 increases. For this reason, the voltage required to open the first shut-off valve 19 is higher than the voltage required to open the second shut-off valve 20. That is, the time it takes for the battery 200 voltage to recover to the voltage required to open the first shut-off valve 19 is longer than the time it takes for the voltage to recover to the voltage required to open the second shut-off valve 20. In contrast, in this embodiment, by opening the second shut-off valve 20 first, which requires a lower voltage to open than the first shut-off valve 19, the first shut-off valve 19 and the second shut-off valve 20 can be opened quickly.

[0047] (2-4) In this embodiment, the second shut-off valve 20, which is located in the fuel piping 17 close to the delivery pipe 18, is opened before the first shut-off valve 19, which is located near the outlet of the fuel tank 12. As a result, even before the first shut-off valve 19 is opened, the second shut-off valve 20 can be opened to supply the fuel remaining in the fuel piping 17 to the delivery pipe 18, thereby enabling the engine 10 to be started quickly.

[0048] (Third embodiment) Next, a third embodiment of the engine control device will be described with reference to Figures 5 and 6.

[0049] In the third embodiment, the control device 100 is connected to a voltage sensor that detects the voltage of the battery 200. The voltage sensor outputs a detection signal to the control device 100 regarding the detected voltage of the battery 200.

[0050] <Startup process in the third embodiment> As shown in Figure 6, during the startup process, the control device 100 starts the CPU 110 in the same manner as in the first embodiment (step S31) and starts driving the starter motor 300 (step S32).

[0051] Subsequently, the control device 100 determines whether the voltage of the battery 200 is equal to or greater than the first valve opening permission voltage (step S33). In this embodiment, the first valve opening permission voltage is the voltage required to open the second shut-off valve 20. If the voltage is less than the first valve opening permission voltage (step S33: NO), the control device 100 waits for a certain period of time (step S34) and then returns to the process in step S33. As a result, the control device 100 waits until the voltage of the battery 200 becomes equal to or greater than the first valve opening permission voltage. On the other hand, if the voltage is equal to or greater than the first valve opening permission voltage (step S33: YES), the control device 100 opens the second shut-off valve 20 (step S35).

[0052] Next, the control device 100 determines whether the voltage of the battery 200 is equal to or greater than the second valve opening permission voltage (step S36). In this embodiment, the second valve opening permission voltage is the voltage required to open the first shut-off valve 19. If the voltage is less than the second valve opening permission voltage (step S36: NO), the control device 100 waits for a certain period of time (step S37) and then returns to the process in step S36. As a result, the control device 100 waits until the voltage of the battery 200 becomes equal to or greater than the second valve opening permission voltage. On the other hand, if the voltage is equal to or greater than the second valve opening permission voltage (step S36: YES), the control device 100 opens the first shut-off valve 19 (step S38). After that, the control device 100 starts fuel injection control and ignition control (step S39) and finishes the starting process.

[0053] Thus, in this embodiment, the condition for opening the valve is met when the voltage of the battery 200 becomes equal to or greater than the valve opening permission voltage. That is, the control device 100 opens the first shut-off valve 19 and the second shut-off valve 20 when the valve opening condition is met, which is when the voltage of the battery 200 exceeds a predetermined value. In this embodiment, the first valve opening permission voltage corresponds to a first value required to open the second shut-off valve 20, and the second valve opening permission voltage corresponds to a second value required to open the first shut-off valve 19.

[0054] <Operation of the third embodiment> As shown in Figure 5(a), in the startup process described above, as in the first and second embodiments, when the ignition switch 400 is turned ON, the CPU 110 starts up (time t11). As shown in Figure 5(b), after the CPU 110 starts up, the starter motor 300 is then driven (time t12). As a result, as shown in Figure 5(e), the engine speed begins to increase. At this time, as shown in Figure 5(f), the voltage of the battery 200 decreases due to the start of the starter motor 300. Then, as shown in Figure 5(c), the second shut-off valve 20 is opened when the voltage of the battery 200 becomes equal to or greater than the first valve opening permission voltage (time t13). Also, as shown in Figure 5(d), the first shut-off valve 19 is opened when the voltage of the battery 200 becomes equal to or greater than the first valve opening permission voltage (time t14). During this time, as shown in Figure 3(f), the voltage of the battery 200 recovers over time. As a result, during the starting process, the first shut-off valve 19 and the second shut-off valve 20 can be opened sequentially as the voltage of the battery 200, which has decreased due to the start of the starter motor 300, recovers.

[0055] <Effects of the Third Embodiment> (3-1) In the starting process of this embodiment, the first shut-off valve 19 and the second shut-off valve 20 are opened on the condition that the voltage of the battery 200 becomes equal to or greater than the valve opening permission voltage. This prevents the first shut-off valve 19 and the second shut-off valve 20 from being unable to open due to a low voltage of the battery 200. Therefore, starting failures are less likely to occur.

[0056] (3-2) The voltage required to open the first shut-off valve 19 is higher than the voltage required to open the second shut-off valve 20. In contrast, in this embodiment, by opening the second shut-off valve 20 first, which requires a lower voltage to open than the first shut-off valve 19, both the first shut-off valve 19 and the second shut-off valve 20 can be opened quickly.

[0057] <Example of changes> Each of the embodiments described above can be implemented with the following modifications. Each embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0058] During the starting process, the control device 100 may simultaneously open the first shut-off valve 19 and the second shut-off valve 20 when the voltage of the battery 200 reaches or exceeds a predetermined valve-opening permission voltage. In this case, the valve-opening permission voltage should be set to a voltage higher than either the first valve-opening permission voltage when the second shut-off valve 20 is opened alone, or the second valve-opening permission voltage when the first shut-off valve 19 is opened alone.

[0059] During the starting process, the control device 100 may control the shut-off valves 19 and 20 to open only after a predetermined waiting time has elapsed since the starter motor 300 was driven and the voltage of the battery 200 has risen to or above a predetermined valve opening permit voltage. In other words, the valve opening conditions for opening the shut-off valves 19 and 20 may include both the fact that a predetermined waiting time has elapsed since the starter motor 300 was driven and that the voltage of the battery 200 has exceeded a predetermined value.

[0060] When the first shut-off valve 19 and the second shut-off valve 20 are opened at different times, the control device 100 may open the first shut-off valve 19 before the second shut-off valve 20. This allows fuel to be supplied quickly from the fuel tank 12 to the fuel piping 17.

[0061] The method for determining the valve opening waiting time may be changed as appropriate. For example, the valve opening waiting time may be determined based on conditions other than the passage fuel temperature, cooling water temperature, and ambient temperature, in addition to or instead of these. For example, the valve opening waiting time may be determined according to the passage fuel pressure, which is the pressure of the fuel in the fuel passage 14 detected by the pressure sensors 23 and 24. In this case, the control device 100 may determine a shorter valve opening waiting time when the passage fuel pressure is low compared to when the passage fuel pressure is high. When the passage fuel pressure is low, it is thought that there is less fuel remaining in the fuel passage 14 compared to when the passage fuel pressure is high. Therefore, by determining a shorter valve opening waiting time when the passage fuel pressure is low compared to when the passage fuel pressure is high, the control device 100 can quickly supply fuel from the fuel tank 12 to the fuel passage 14 when there is little fuel remaining in the fuel passage 14. Furthermore, the valve opening waiting time does not have to be determined by the control device 100, but may be a predetermined fixed time.

[0062] The engine 10 may have a configuration that includes only one of the first shut-off valve 19 and the second shut-off valve 20. The trigger for starting the starter motor 300 may be changed as appropriate. For example, the starter motor 300 may be started after the CPU 110 is activated when the ignition switch 400 is turned on, and then triggered by the operation of a predetermined operating means. [Explanation of Symbols]

[0063] 10…Engine 11…Engine body 12…Fuel tank 13…Fuel injector 14…Fuel passage 17…Fuel piping 18…Delivery pipe 19…First shut-off valve 20…Second shut-off valve 21…Pressure reducing valve 23…First pressure sensor 24…Second pressure sensor 26…First temperature sensor 27…Second temperature sensor 28…Relief valve 100…Control unit 110…CPU 120…Memory 200…Battery 300…Starter motor 400…Ignition switch 500…Coolant temperature sensor 600…Outside temperature sensor

Claims

1. An engine control device for controlling an engine comprising a shut-off valve provided in a fuel passage connecting a fuel tank and a fuel injection valve, a starter motor used for starting the engine, and a battery that supplies power to the shut-off valve and the starter motor, The drive control of the starter motor, The system includes a processing circuit that performs the opening and closing control of the aforementioned shut-off valve, The processing circuit performs control to open the shut-off valve when predetermined valve opening conditions are met after the starter motor has started to drive. Engine control device.

2. The valve opening condition is that a predetermined waiting time has elapsed since the starter motor was started. The engine control device according to claim 1.

3. This invention is applied to an engine comprising a first shut-off valve provided in the fuel passage and a second shut-off valve disposed in the fuel passage closer to the fuel injection valve than the first shut-off valve. The aforementioned processing circuit is The second shut-off valve is opened when a first waiting period has elapsed since the starter motor was started. After the first waiting period has elapsed, the control system is activated to open the first shut-off valve when the second waiting period has elapsed. The engine control device according to claim 2.

4. The valve opening condition is that the voltage of the battery exceeds a predetermined value. The engine control device according to claim 1.

5. This invention is applied to an engine comprising a first shut-off valve provided in the fuel passage and a second shut-off valve disposed in the fuel passage closer to the fuel injection valve than the first shut-off valve. The aforementioned processing circuit is The second shut-off valve is opened when the voltage of the aforementioned battery exceeds a first value. The control is performed to open the first shut-off valve when the voltage of the battery exceeds a second value, which is higher than the first value. The engine control device according to claim 4.

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