Engine control device

Abstract

The invention provides an engine control device. An engine is provided with: a shut-off valve provided in a fuel passage connecting a fuel tank and a fuel injection valve; a starter motor for starting the engine; and a battery that supplies power to the shut-off valve and the starter motor. The engine control device includes a processing circuit configured to execute drive control of the starter motor and opening and closing control of the shutoff valve. The processing circuit is configured to perform control to open the shut-off valve when a predetermined valve opening condition is satisfied after the start of driving the starter motor.

Description

Technical Field

[0001] This disclosure relates to engine control devices. Background Technology

[0002] Conventionally, as engine control devices, there are known devices that control a shut-off valve installed in the fuel passage connecting the fuel tank and the fuel injection valve. In the engine control device disclosed in Japanese Patent Application Publication No. 2020-56380, the shut-off valve is closed when the engine is stopped. Summary of the Invention

[0003] [The problem the invention aims to solve] In the control system of such engines, the shut-off valve needs to be opened when the engine is started. However, depending on the timing of the starter motor's operation and the control of the shut-off valve's opening, the engine may fail to start properly, resulting in a starting failure.

[0004] [Methods used to solve problems] In one aspect of this disclosure, an engine control device is provided. The engine includes: a shut-off valve disposed in a fuel passage connecting a fuel tank to a fuel injection valve; a starter motor for starting the engine; and a battery for supplying power to the shut-off valve and the starter motor. The engine control device includes a processing circuit configured to perform drive control of the starter motor and opening / closing control of the shut-off valve. The processing circuit is configured to, after the starter motor begins to drive, control the shut-off valve to open based on the fulfillment of predetermined valve opening conditions. Attached Figure Description

[0005] Figure 1 This is a schematic diagram showing the structure of one embodiment of an engine and its control device.

[0006] Figure 2 This is a flowchart representing the starting process that initiates engine startup.

[0007] Figure 3 It is a timing diagram showing the timing 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 the engine is started.

[0008] Figure 4 This is a flowchart illustrating the startup process in the second embodiment.

[0009] Figure 5It is a timing diagram showing the timing 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 the engine is started in the second or third embodiment.

[0010] Figure 6 This is a flowchart illustrating the startup process in the third embodiment. Detailed Implementation

[0011] (First Implementation) The following is for reference Figures 1-3 A first embodiment of the engine control device will be described.

[0012] <Structure of the engine and its control unit> Figure 1 The engine 10 shown is mounted on a vehicle. The fuel for the engine 10 is a gaseous fuel. An example of a gaseous fuel is hydrogen.

[0013] Engine 10 has an internal combustion engine body 11. Figure 1 The description of the multiple cylinders and multiple spark plugs of the internal combustion engine body 11 is omitted. The internal combustion engine body 11 generates power to propel the vehicle by burning fuel injected from multiple fuel injection valves 13 inside each cylinder.

[0014] The engine 10 includes a fuel tank 12, multiple fuel injection valves 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 a compressed state in the fuel tank 12. Gaseous fuel is supplied from the fuel tank 12 to each fuel injection valve 13. Each cylinder is provided with a fuel injection valve 13. The fuel injection valve 13 supplies fuel to the cylinder.

[0015] Fuel passage 14 connects fuel tank 12 to each fuel injection valve 13. Fuel passage 14 consists of fuel piping 17 connected to fuel tank 12 and delivery pipes 18 connecting fuel piping 17 to each fuel injection valve 13. Fuel stored in fuel tank 12 is supplied to each fuel injection valve 13 via fuel piping 17 and delivery pipes 18.

[0016] A first shut-off valve 19 and a second shut-off valve 20 are disposed 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 valve state and a closed valve state by the opening and closing control of the control device 100. When an opening valve command is received from the control device 100, each shut-off valve 19, 20 becomes an open valve state. When a closing valve command is received from the control device 100, each shut-off valve 19, 20 becomes a closed valve state. Specifically, when an opening valve 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 valves 19, 20. As a result, the shut-off valves 19, 20 become open valve states. When a closing valve 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 valves 19, 20. As a result, the shut-off valves 19, 20 become closed valve states. The first shut-off valve 19 and the second shut-off valve 20 remain open while the engine 10 is running. The first shut-off valve 19 and the second shut-off valve 20 remain closed when the engine 10 is stopped.

[0017] A first shut-off valve 19 is disposed in the fuel passage 14 near the outlet of the fuel tank 12. The first shut-off valve 19 is also disposed at the end of the fuel line 17 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 line 17. When the first shut-off valve 19 is closed, fuel supply from the fuel tank 12 to the fuel line 17 is stopped.

[0018] 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 also located near the delivery pipe 18 in the fuel piping 17. 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, fuel supply to the delivery pipe 18 through the fuel piping 17 is stopped.

[0019] A pressure reducing valve 21 is disposed between the first shut-off valve 19 and the second shut-off valve 20 in 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.

[0020] An overflow valve 28 is provided between the pressure reducing valve 21 and the second shut-off valve 20 in the fuel passage 14. The overflow valve 28 discharges fuel from the fuel pipeline 17 to the outside of the fuel pipeline 17 when the pressure in the fuel pipeline 17 becomes a certain level or higher.

[0021] The first pressure sensor 23 and the second pressure sensor 24 detect the pressure of the fuel in the fuel passage 14, i.e., the passage fuel pressure. Each pressure sensor 23 and 24 outputs a detection signal related to the detected passage fuel pressure to the control device 100.

[0022] A first pressure sensor 23 is disposed between a first shut-off valve 19 and a second shut-off valve 20 in the fuel passage 14. The first pressure sensor 23 detects a first-pass fuel pressure representing the fuel pressure in the passage between the first shut-off valve 19 and the second shut-off valve 20. This first-pass fuel pressure is equivalent to the fuel pressure in the fuel piping 17. A 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-pass fuel pressure representing the fuel pressure in the passage between the second shut-off valve 20 and the fuel injection valve 13. This second-pass fuel pressure is equivalent to the fuel pressure in the delivery pipe 18.

[0023] The engine 10 includes a first temperature sensor 26 and a second temperature sensor 27. Each temperature sensor 26 and 27 detects the temperature of the fuel in the fuel passage 14, i.e., the passage fuel temperature. Each temperature sensor 26 and 27 outputs a detection signal related to the detected passage fuel temperature to the control device 100.

[0024] A first temperature sensor 26 is disposed between the first shut-off valve 19 and the pressure reducing valve 21. The first temperature sensor 26 detects a first-pass fuel temperature, representing the fuel temperature in the passage between the first shut-off valve 19 and the pressure reducing valve 21. This first-pass fuel temperature corresponds to the fuel temperature in the portion of the fuel in the fuel piping 17 upstream of the pressure reducing valve 21. A second temperature sensor 27 is disposed between the second shut-off valve 20 and the fuel injection valve 13. The second temperature sensor 27 detects a second-pass fuel temperature, representing the fuel temperature in the passage between the second shut-off valve 20 and the fuel injection valve 13. This second-pass fuel temperature corresponds to the fuel temperature in the delivery pipe 18.

[0025] The control device 100 performs various controls on the engine 10 by controlling various controlled objects, 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 opening signal to the shut-off valves 19 and 20, and drives the shut-off valves 19 and 20 to close by sending a closing signal to the shut-off valves 19 and 20.

[0026] 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 to perform various controls on the control device 100. In this embodiment, the CPU 110 corresponds to a processing circuit.

[0027] The control unit 100 is connected to the battery 200, starter motor 300, ignition switch 400, coolant temperature sensor 500, and external temperature sensor 600. The starter motor 300 receives power from the battery 200 to start the engine 10. The ignition switch 400 detects whether the vehicle driver requests to start or stop the engine 10 by inputting its operating state to the control unit 100. That is, when the ignition switch 400 is turned on, the control unit 100 determines that there is a request to start the engine 10; when the ignition switch 400 is turned off, the control unit 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 coolant temperature to the control unit 100. The external temperature sensor 600 detects the external temperature. The external temperature sensor 600 outputs a detection signal related to the detected external temperature to the control device 100.

[0028] The control device 100 acquires various values ​​required for the control of the engine 10. For example, the control device 100 acquires detection signals from pressure sensor 23, pressure sensor 24, temperature sensor 26, temperature sensor 27, ignition switch 400, coolant temperature sensor 500, and external air temperature sensor 600.

[0029] <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.

[0030] like Figure 2 As shown, during the startup process, the control device 100 starts the CPU 110 (step S1). Next, the control device 100 performs drive control to start the drive of the starter motor 300 (step S2).

[0031] Subsequently, the control device 100 determines the standby time until the first shut-off valve 19 and the second shut-off valve 20 are opened, i.e., the valve-opening standby time (step S3). As an example, the control device 100 determines the valve-opening standby time based on the fuel temperature in the passage detected by temperature sensors 26 and 27. Specifically, the control device 100 determines the valve-opening standby time based on the fuel temperature in the passage detected by either temperature sensor 26 or temperature sensor 27. For example, if the fuel temperature in the passage is low, the control device 100 determines a longer time than if the fuel temperature in the passage is high as the valve-opening standby time. Additionally, as an example, the control device 100 determines the valve-opening standby time based on the cooling water temperature detected by the cooling water temperature sensor 500. Specifically, if the cooling water temperature is low, the control device 100 determines a longer time than if the cooling water temperature is high as the valve-opening standby time. Furthermore, as an example, the control device 100 determines the valve-opening standby time based on the external air temperature detected by the external air temperature sensor 600. Specifically, when the external temperature is low, the control device 100 determines a longer time as the valve opening standby time than when the external temperature is high.

[0032] Next, the control device 100 determines whether the predetermined valve-opening standby time has elapsed (step S4). If the valve-opening standby 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 processing of step S4. Thus, the control device 100 waits until the valve-opening standby time has elapsed.

[0033] After the valve-opening standby 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 standby time is equivalent 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 based on the fulfillment of the valve-opening condition after the valve-opening standby time. Then, the control device 100 starts fuel injection control and ignition control (step S7), ending the start-up process.

[0034] Fuel injection control controls each fuel injection valve 13 to inject fuel into each cylinder. Ignition control controls each spark plug to ignite the air-fuel mixture in each cylinder.

[0035] <The Role of the First Implementation Method> like Figure 3 As shown, in the above-described starting process, after the control device 100 starts driving the starter motor 300, it waits for the predetermined valve opening conditions to be met before opening the first shut-off valve 19 and the second shut-off valve 20. That is, 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 are not performed simultaneously.

[0036] Specifically, such as Figure 3 As shown in (a), if the ignition switch 400 is turned on, the CPU 110 starts (at time t1). Figure 3 As shown in (b), after the CPU 110 starts up, the drive of the motor 300 begins (at time t2). Therefore, as... Figure 3 As shown in (e), the engine speed begins to increase. At this time, as... Figure 3 As shown in (f), by starting the drive of the motor 300, the voltage of the battery 200 decreases. Furthermore, as... Figure 3 As shown in (c) and (d), the first shut-off valve 19 and the second shut-off valve 20 open after a valve-opening standby time has elapsed since the start of the starter motor 300 (time t3). During this period, as... Figure 3 As shown in (f), the voltage of the battery 200, which decreases due to the start of the starter motor 300, recovers over time. Thus, during the starting process, the period during which the voltage of the battery 200 drops significantly due to the start of the starter motor 300 can be avoided, allowing the first shut-off valve 19 and the second shut-off valve 20 to open.

[0037] 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 standby time based on the detection results of the temperature sensors 26 and 27, the coolant temperature sensor 500, and the external air temperature sensor 600. That is, the control device 100 can determine an appropriate time as the time for restoring the voltage of the battery 200 based on the temperature of the engine 10 and the fuel.

[0038] <Effects of the First Implementation Method> (1-1) During the starting process, the effect of the voltage drop in the battery 200 caused by the start of the starter motor 300 can be suppressed, which may prevent the first shut-off valve 19 and the second shut-off valve 20 from opening. Therefore, it is difficult for starting failure to occur.

[0039] (1-2) During the starting process, a time is ensured for the voltage of the battery 200 to recover from the start of driving the starter motor 300 until the first shut-off valve 19 and the second shut-off valve 20 are opened. Thus, the first shut-off valve 19 and the second shut-off valve 20 can be opened after the voltage of the battery 200 begins to recover.

[0040] (1-3) During the startup process, the control device 100 can determine the valve opening standby time suitable for restoring the voltage of the battery 200 to the voltage required to open the first shut-off valve 19 and the second shut-off valve 20. As a result, the situation where the first shut-off valve 19 and the second shut-off valve 20 cannot be opened due to the effect of the voltage drop of the battery 200 can be further suppressed.

[0041] (Second Implementation) Next, refer to Figure 4 and Figure 5 A second embodiment of the engine control device will be described.

[0042] <Startup Process in the Second Implementation> like Figure 4 As shown, in the startup process, the control device 100 starts the CPU 110 in the same way as in the first embodiment (step S11) and starts the drive of the starter motor 300 (step S12).

[0043] Subsequently, the control device 100 determines the standby time until the second shut-off valve 20 is opened, which is the first valve-opening standby time (step S13). In this embodiment, the first valve-opening standby time is equivalent to the first standby time. As an example, the control device 100 determines the first valve-opening standby time based on the detection results of the temperature sensor 26, temperature sensor 27, cooling water temperature sensor 500, and external air temperature sensor 600, similar to when determining the valve-opening standby time in the first embodiment.

[0044] Next, the control device 100 determines whether the predetermined first valve-opening standby time has elapsed (step S14). If the first valve-opening standby 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 processing of step S14. Thus, the control device 100 waits until the first valve-opening standby time has elapsed. On the other hand, if the first valve-opening standby time has elapsed (step S14: Yes), the control device 100 opens the second shut-off valve 20 (step S16).

[0045] After opening the second shut-off valve 20, the control device 100 determines the standby time until the first shut-off valve 19 is opened, which is the second valve-opening standby time (step S17). In this embodiment, the second valve-opening standby time is equivalent to the second standby time. As an example, the control device 100 determines the second valve-opening standby time based on the detection results of the temperature sensor 26, temperature sensor 27, cooling water temperature sensor 500, and external air temperature sensor 600, similar to when determining the valve-opening standby time in the first embodiment.

[0046] Next, the control device 100 determines whether the predetermined second valve-opening standby time has elapsed (step S18). If the second valve-opening standby 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. Thus, the control device 100 waits until the second valve-opening standby time has elapsed. On the other hand, if the second valve-opening standby time has elapsed (step S18: Yes), the control device 100 opens the first shut-off valve 19 (step S20). Then, the control device 100 starts fuel injection control and ignition control (step S21) and ends the start-up process.

[0047] <Function of the Second Implementation Method> like Figure 5 As shown, in the above-described starting process, after the control device 100 starts driving the starter motor 300, it opens the first shut-off valve 19 and the second shut-off valve 20 at different times. That is, 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 are not performed simultaneously.

[0048] Specifically, such as Figure 5 As shown in (a), if the ignition switch 400 is turned on, the CPU 110 starts (at time t11). Figure 5 As shown in (b), after the CPU 110 starts up, the drive of the motor 300 begins (at time t12). Thus, as... Figure 5 As shown in (e), the engine speed begins to increase. At this time, as... Figure 5 As shown in (f), by starting the drive of the motor 300, the voltage of the battery 200 decreases. Then, as... Figure 5 As shown in (c), the second shut-off valve 20 opens after a first valve-opening standby time has elapsed since the start of the starter motor 300's operation (time t13). Additionally, as... Figure 5 As shown in (d), the first shut-off valve 19 opens after a second opening standby time has elapsed since the second shut-off valve 20 opened (time point t14). During this period, as... Figure 5 As shown in (f), the voltage of battery 200 recovers over time. Thus, during the startup process, as the voltage of battery 200, which had decreased due to the start-up of the starter motor 300, recovers, the first shut-off valve 19 and the second shut-off valve 20 can be opened sequentially.

[0049] <Effects of the Second Implementation> (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 valves simultaneously. Therefore, in this embodiment, during the startup process, it is possible to suppress the situation where the first shut-off valve 19 and the second shut-off valve 20 cannot be opened. Therefore, startup failure is unlikely to occur.

[0050] (2-2) In this embodiment, by opening the first shut-off valve 19 and the second shut-off valve 20 at different times, the first shut-off valve 19 and the second shut-off valve 20 can be opened with a voltage lower than that required to open both valves simultaneously. As a result, compared with 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, thus enabling the engine 10 to start quickly.

[0051] (2-3) The pressure in the fuel line 17 is higher upstream of the pressure reducing valve 21 than downstream of it. 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 it. Furthermore, the higher the pressure applied to each shut-off valve 19, 20, the higher the voltage required to open that valve. Therefore, 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 voltage to recover to the voltage required to open the first shut-off valve 19 is longer than the time it takes 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 (which requires a lower voltage to open) first, both the first and second shut-off valves can be opened quickly.

[0052] (2-4) In this embodiment, the second shut-off valve 20, which is located in the fuel line 17 near the delivery pipe 18, opens 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 opens, the fuel remaining in the fuel line 17 can be supplied to the delivery pipe 18 by opening the second shut-off valve 20, thus enabling the engine 10 to start quickly.

[0053] (Third implementation method) Next, refer to Figure 5 and Figure 6 A third embodiment of the engine control device will be described.

[0054] 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 related to the detected voltage of the battery 200 to the control device 100.

[0055] <Startup Process in the Third Embodiment> like Figure 6 As shown, in the startup process, the control device 100 starts the CPU 110 in the same way as in the first embodiment (step S31) and starts the drive of the starter motor 300 (step S32).

[0056] Next, the control device 100 determines whether the voltage of the battery 200 is above the first valve opening allowable voltage (step S33). In this embodiment, the first valve opening allowable voltage is the voltage required to open the second shut-off valve 20. If the voltage is less than the first valve opening allowable voltage (step S33: No), the control device 100 waits for a certain period of time (step S34) and then returns to the processing of step S33. Thus, the control device 100 waits until the voltage of the battery 200 becomes above the first valve opening allowable voltage. On the other hand, if the voltage is above the first valve opening allowable voltage (step S33: Yes), the control device 100 opens the second shut-off valve 20 (step S35).

[0057] Next, the control device 100 determines whether the voltage of the battery 200 is above the second valve opening allowable voltage (step S36). In this embodiment, the second valve opening allowable voltage is the voltage required to open the first shut-off valve 19. If the voltage is less than the second valve opening allowable voltage (step S36: No), the control device 100 waits for a certain period of time (step S37) and then returns to the process of step S36. Thus, the control device 100 waits until the voltage of the battery 200 becomes above the second valve opening allowable voltage. On the other hand, if the voltage is above the second valve opening allowable voltage (step S36: Yes), the control device 100 opens the first shut-off valve 19 (step S38). Then, the control device 100 starts fuel injection control and ignition control (step S39) and ends the starting process.

[0058] Thus, in this embodiment, the voltage of the battery 200 is above the valve-opening allowable voltage, which corresponds to the fulfillment of the valve-opening condition. That is, the control device 100 uses the fulfillment of the valve-opening condition, where the voltage of the battery 200 exceeds a predetermined value, as a trigger to open the first shut-off valve 19 and the second shut-off valve 20. In this embodiment, the first valve-opening allowable voltage corresponds to a first value required to open the second shut-off valve 20, and the second valve-opening allowable voltage corresponds to a second value required to open the first shut-off valve 19.

[0059] <The Role of the Third Implementation Method> like Figure 5 As shown in (a), in the above-described startup process, similar to the first and second embodiments, if the ignition switch 400 is turned on, the CPU 110 starts (at time t11). Figure 5As shown in (b), after the CPU 110 starts up, the drive of the motor 300 begins (at time t12). Thus, as... Figure 5 As shown in (e), the engine speed begins to increase. At this time, as... Figure 5 As shown in (f), by starting the drive of the motor 300, the voltage of the battery 200 decreases. Then, as... Figure 5 As shown in (d), the second shut-off valve 20 opens when the voltage of the battery 200 becomes above the first valve-opening allowable voltage (time point t13). Additionally, as... Figure 5 As shown in (c), the first shut-off valve 19 opens when the voltage of the battery 200 becomes above the second opening allowable voltage (time point t14). During this period, as Figure 5 As shown in (f), the voltage of battery 200 recovers over time. Thus, during the startup process, as the voltage of battery 200, which had decreased due to the start-up of the starter motor 300, recovers, the first shut-off valve 19 and the second shut-off valve 20 can be opened sequentially.

[0060] <Effects of the Third Implementation Method> (3-1) In the startup process of this embodiment, the first shut-off valve 19 and the second shut-off valve 20 are opened when the voltage of the battery 200 is above the valve opening allowable voltage. This prevents situations where the first shut-off valve 19 and the second shut-off valve 20 cannot be opened due to a low voltage of the battery 200. Therefore, startup failure is less likely to occur.

[0061] (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, which requires a lower voltage to open, first shut-off valve 19 and second shut-off valve 20, both valves can be opened quickly.

[0062] <Example of Change> The above-described embodiments can be implemented by modification as follows. The embodiments and the following modifications can be combined with each other within the scope of technical inconsistency.

[0063] • During startup, the control device 100 may also 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 allowable voltage. In this case, the valve-opening allowable voltage may be set to a voltage higher than either the first valve-opening allowable voltage when the second shut-off valve 20 is opened alone or the second valve-opening allowable voltage when the first shut-off valve 19 is opened alone.

[0064] • During the startup process, the control device 100 may also control the opening of the shut-off valves 19 and 20 based on the conditions that a predetermined waiting time has elapsed since the starter motor 300 was started and the voltage of the battery 200 has reached or exceeded a predetermined allowable opening voltage. That is, the opening conditions for 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 started and the voltage of the battery 200 has exceeded a predetermined value.

[0065] • When the first shut-off valve 19 and the second shut-off valve 20 open at different times, the control device 100 can also open the first shut-off valve 19 before the second shut-off valve 20. This allows for rapid fuel supply from the fuel tank 12 to the fuel line 17.

[0066] The method for determining the valve-opening standby time can also be appropriately modified. For example, the valve-opening standby time can be determined instead of the fuel temperature in the passage, the water temperature of the cooling water, and the outside air temperature, or based on conditions different from these. For example, the valve-opening standby time can also be determined based on the fuel pressure in the fuel passage 14 detected by pressure sensors 23 and 24, i.e., the passage fuel pressure. In this case, the control device 100 can determine a shorter time as the valve-opening standby time when the passage fuel pressure is low compared to when the passage fuel pressure is high. At this time, when the passage fuel pressure is low, it is assumed that there is less fuel remaining in the fuel passage 14 compared to when the passage fuel pressure is high. Therefore, when the passage fuel pressure is low, the control device 100 determines a shorter time as the valve-opening standby time compared to when the passage fuel pressure is high, thereby enabling rapid fuel supply from the fuel tank 12 to the fuel passage 14 when there is less fuel remaining in the fuel passage 14. Alternatively, the valve-opening standby time may not be determined by the control device 100, or it may be a predetermined fixed time.

[0067] • The engine 10 may also be a structure that has only one of the first shut-off valve 19 and the second shut-off valve 20.

[0068] • The starting trigger for driving the starter motor 300 can also be changed appropriately. For example, the starter motor 300 can also be driven by the operation of a specified operating unit after the CPU 110 is started by the operation of the ignition switch 400.

Claims

1. A control device for an engine, comprising: a shut-off valve disposed in a fuel passage connecting a fuel tank to a fuel injection valve; a starter motor for starting the engine; and a battery for supplying power to the shut-off valve and the starter motor, wherein... The engine control unit includes a processing circuit configured to perform drive control of the starter motor and opening / closing control of the shut-off valve. The processing circuit is configured to control the opening of the shut-off valve after the starter motor has started driving, based on the fulfillment of predetermined valve opening conditions.

2. The engine control device according to claim 1, wherein, The valve opening condition is that a predetermined standby time has elapsed since the start of the starter motor.

3. The engine control device according to claim 2, wherein, The engine control device is applied to the engine, which includes a first shut-off valve and a second shut-off valve. The first shut-off valve is disposed in the fuel passage, and the second shut-off valve is disposed in the fuel passage at a position closer to the fuel injection valve than the first shut-off valve. The processing circuit is configured to perform the following control: The second shut-off valve is opened after a first standby time has elapsed since the start of the motor was activated. After the first standby time has elapsed, the first shut-off valve is opened, taking the second standby time as an opportunity.

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

5. The engine control device according to claim 4, wherein, The engine control device is applied to the engine, which includes a first shut-off valve and a second shut-off valve. The first shut-off valve is disposed in the fuel passage, and the second shut-off valve is disposed in the fuel passage at a position closer to the fuel injection valve than the first shut-off valve. The processing circuit is configured to perform the following control: The second shut-off valve is opened when the battery voltage exceeds a first value. The first shut-off valve is opened when the voltage of the battery exceeds a second value that is higher than the first value.

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