control device

Abstract

The present invention provides a control device that can suppress the misdiagnosis of a shut-off valve failure when an engine stall occurs during the execution of a fault detection routine. [Solution] The control device 40 is applied to the fuel supply system 10. The control device 40 can control the hydrogen engine 15 and the shut-off valves, which are the first shut-off valve 21 and the second shut-off valve 22. When a user of a vehicle equipped with the fuel supply system 10 requests that the hydrogen engine 15 be stopped, the control device 40 closes the shut-off valves and, while continuing to operate the hydrogen engine 15, observes the rate at which the hydrogen gas pressure drops downstream of the shut-off valves. If the rate of drop is slow, the control device 40 executes a fault determination routine in which it determines that the shut-off valves have not been closed properly. If the hydrogen engine 15 stops due to engine stall while the fault determination routine is being executed, the control device 40 cancels the fault determination routine.

Description

Technical Field

[0001] This invention relates to a control device.

Background Art

[0002] Patent Document 1 describes a control device in a fuel supply system. The fuel supply system includes a hydrogen engine that uses hydrogen gas as fuel and a fuel tank that stores the hydrogen gas used by the hydrogen engine. The hydrogen gas stored in the fuel tank is sent to the hydrogen engine through a hydrogen pipe. The fuel supply system includes a shut-off valve on the hydrogen pipe. The shut-off valve blocks the hydrogen gas sent from the fuel tank to the hydrogen engine in the hydrogen pipe.

[0003] The control device controls the hydrogen engine and the shut-off valve in the fuel supply system. The control device executes a failure determination routine. In the failure determination routine, the control device determines whether the shut-off valve has failed based on the change in the pressure of the hydrogen gas in the portion between the shut-off valve and the hydrogen engine in a state where the shut-off valve is closed and the hydrogen engine is consuming hydrogen gas. Here, the state where the shut-off valve has failed means that the shut-off valve is not properly closed and the hydrogen gas is not blocked in the hydrogen pipe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Engine stall may occur during the execution of the failure determination routine. There is room for improvement in the countermeasures when engine stall occurs during the execution of the failure determination routine.

Means for Solving the Problems

[0006] A control device for solving the above problems is applied to a fuel supply system. The fuel supply system includes a hydrogen engine that uses hydrogen gas as fuel, a fuel tank for storing the hydrogen gas, hydrogen piping for leading the hydrogen gas from the fuel tank to the hydrogen engine, a shut-off valve provided in the middle of the hydrogen piping for shutting off the supply of hydrogen gas from the fuel tank to the hydrogen engine, and an injector for injecting the hydrogen gas into the hydrogen engine. This control device can control the shut-off valve and the hydrogen engine. When a user of a vehicle equipped with the fuel supply system requests that the hydrogen engine be stopped, this control device closes the shut-off valve and, while continuing to operate the hydrogen engine, observes the rate of pressure drop of the hydrogen gas downstream of the shut-off valve, and executes a fault determination routine that determines that the shut-off valve has not been properly closed if the rate of pressure drop is slow. If the hydrogen engine stops due to engine stall while the fault determination routine is being executed, this control device cancels the fault determination routine. [Effects of the Invention]

[0007] The above-described control device can suppress the misdiagnosis of a shut-off valve failure when an engine stall occurs during the execution of the fault detection routine. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing the configuration of a fuel supply system equipped with a control device according to one embodiment. [Figure 2] Figure 2 is a flowchart showing the sequence of processes in the first fault determination routine executed by the control device shown in Figure 1. [Figure 3] Figure 3 is a flowchart showing the sequence of processes in the second fault determination routine executed by the control device in Figure 1. [Figure 4]Figure 4 is a flowchart showing the sequence of processes executed by the control unit when an engine stall occurs while the vehicle is in motion. [Modes for carrying out the invention]

[0009] An embodiment of the control device will be described below with reference to Figures 1 to 4. <Configuration of fuel supply system 10> The fuel supply system 10 is installed in the vehicle.

[0010] The fuel tank 11 stores hydrogen gas supplied from an external source. As shown in Figure 1, the fuel tank 11 is connected to the hydrogen engine 15 through hydrogen piping 12. Hydrogen piping 12 guides hydrogen gas from the fuel tank 11 to the hydrogen engine 15. The hydrogen gas guided to the hydrogen engine 15 is injected into the cylinders of the hydrogen engine 15 from the injectors of the hydrogen engine 15.

[0011] The hydrogen engine 15 outputs driving force to the vehicle equipped with the fuel supply system 10 by burning hydrogen gas as fuel in its cylinder. As shown in Figure 1, a rotational speed sensor 14 is installed on the hydrogen engine 15. The rotational speed sensor 14 measures the rotational speed of the hydrogen engine 15.

[0012] As shown in Figure 1, a regulator 13, multiple shut-off valves, and multiple pressure sensors are installed along the hydrogen piping 12. The regulator 13 adjusts the pressure of the hydrogen gas supplied from the fuel tank 11 to the hydrogen engine 15 to a level usable by the hydrogen engine 15 by reducing the pressure of the hydrogen gas.

[0013] Figure 1 shows the high-pressure section HS and the low-pressure section LS in the hydrogen piping 12. The high-pressure section HS is the part of the hydrogen piping 12 through which the hydrogen gas passes before passing through the regulator 13. The low-pressure section LS is the part of the hydrogen piping 12 through which the hydrogen gas passes after passing through the regulator 13.

[0014] As shown in FIG. 1, the fuel supply system 10 includes, as a plurality of shut-off valves, a first shut-off valve 21 and a second shut-off valve 22. The shut-off valves shut off the supply of hydrogen gas from the fuel tank 11 to the hydrogen engine 15.

[0015] As shown in FIG. 1, the first shut-off valve 21 is installed in a portion of the hydrogen pipe 12 between the fuel tank 11 and the regulator 13. When the first shut-off valve 21 is closed, the high-pressure section HS is shut off.

[0016] As shown in FIG. 1, the second shut-off valve 22 is installed in a portion of the hydrogen pipe 12 between the regulator 13 and the hydrogen engine 15. When the second shut-off valve 22 is closed, the low-pressure section LS is shut off.

[0017] As shown in FIG. 1, the fuel supply system 10 includes a first pressure sensor 31 and a second pressure sensor 32 as a plurality of pressure sensors. As shown in FIG. 1, the first pressure sensor 31 is installed in a portion of the high-pressure section HS downstream of the first shut-off valve 21. As shown in FIG. 1, the second pressure sensor 32 is installed in a portion of the low-pressure section LS downstream of the second shut-off valve 22.

[0018] As shown in FIG. 1, the fuel supply system 10 includes a control device 40. As shown in FIG. 1, the control device 40 is communicably connected to the hydrogen engine 15. The control device 40 can control the operation of the hydrogen engine 15.

[0019] As shown in FIG. 1, the control device 40 is communicably connected to the first shut-off valve 21 and the second shut-off valve 22. The control device 40 can control the opening and closing of the first shut-off valve 21 and the second shut-off valve 22.

[0020] As shown in FIG. 1, the control device 40 is communicably connected to the first pressure sensor 31 and the second pressure sensor 32. The control device 40 can acquire the values measured by the first pressure sensor 31 and the second pressure sensor 32.

[0021] As shown in FIG. 1, the control device 40 is communicably connected to the rotation speed sensor 14. The control device 40 can acquire the value measured by the rotation speed sensor 14. <Fault determination routine> The control device 40 executes a fault determination routine. The fault determination routine is a series of processes performed to determine whether there is a fault in the shut-off valve. The fault in the shut-off valve here refers to a state where, despite the control device 40 instructing the shut-off valve to close, the shut-off valve is not properly closed. For example, when a foreign object is caught between the shut-off valves, the above-mentioned fault occurs.

[0022] FIG. 2 and FIG. 3 show the flow of a series of processes executed when the control device 40 performs the fault determination routine. The series of processes shown in FIGS. 2 and 3 are executed when the ignition switch is turned off. The operation of turning off the ignition switch is an operation by which the user requests the stop of the hydrogen engine 15.

[0023] At the moment when the ignition switch is turned off, the control device 40 is operating the hydrogen engine 15 and has opened the first shut-off valve 21 and the second shut-off valve 22. After the operation of turning off the ignition switch is performed, the control device 40 performs the fault determination routine while continuing to operate the hydrogen engine 15.

[0024] <Mode of processing in the first fault determination routine DF1> The processes from step S11 to step S17 shown in FIG. 2 are the first fault determination routine DF1. The first fault determination routine DF1 is a fault determination routine for determining whether there is a fault in the first shut-off valve 21.

[0025] In the process of step S11, the control device 40 closes the first shut-off valve 21. At this time, the control device 40 maintains the second shut-off valve 22 in an open state. In step S12, the control device 40 obtains pressure P1. Pressure P1 is the pressure of the hydrogen gas downstream of the first shut-off valve 21 immediately after the first shut-off valve 21 is closed. The control device 40 obtains pressure P1 from the first pressure sensor 31.

[0026] In step S13, the control device 40 determines whether a predetermined time t1 has elapsed since the first shut-off valve 21 was closed. The predetermined time t1 is set in advance. If the control device 40 determines that a predetermined time t1 has not elapsed in the process of step S13 (step S13: NO), it proceeds to step S18.

[0027] In step S18, the control device 40 determines whether or not an engine stall occurred during the execution of the first fault determination routine DF1. The control device 40 determines that an engine stall has occurred when the rotational speed of the hydrogen engine 15, as obtained from the rotational speed sensor 14, becomes zero.

[0028] If the control device 40 determines in step S18 that no engine stall has occurred (step S18: NO), it executes the process in step S13 again. If the control device 40 determines that a predetermined time t1 has elapsed in step S13 (step S13: YES), it proceeds to step S14. In step S14, the control device 40 obtains pressure P2. Pressure P2 is the pressure of hydrogen gas downstream of the first shut-off valve 21 when a predetermined time t1 has elapsed after the first shut-off valve 21 is closed. The control device 40 obtains pressure P2 from the first pressure sensor 31.

[0029] In step S15, the control device 40 determines whether the difference between pressure P1 and pressure P2 is greater than or equal to the threshold N1. In the first fault detection routine DF1, the hydrogen gas flowing through the hydrogen piping 12 downstream of the first shut-off valve 21 is gradually consumed by the hydrogen engine 15 over a predetermined time t1. If the first shut-off valve 21 is not properly closed, the rate at which the hydrogen gas pressure downstream of the first shut-off valve 21 decreases is slower compared to when the first shut-off valve 21 is properly closed.

[0030] During the processing in steps S12 to S15, the control device 40 observes the rate at which the hydrogen gas pressure decreases downstream of the first shut-off valve 21. The difference between pressure P1 and pressure P2 reflects the rate at which the hydrogen gas pressure decreases downstream of the first shut-off valve 21.

[0031] The threshold N1 is predetermined by the manufacturer of the control device 40. The manufacturer of the control device 40 sets the threshold N1 based, for example, on the difference between pressure P1 and pressure P2, measured when the first shut-off valve 21 is properly closed.

[0032] In step S15, if the control device 40 determines that the difference between pressure P1 and pressure P2 is greater than or equal to the threshold N1 (step S15: YES), it proceeds to step S16. In step S16, the control device 40 determines that the first shut-off valve 21 is not malfunctioning.

[0033] If the control device 40 determines in step S15 that the difference between pressure P1 and pressure P2 is less than the threshold N1 (step S15: NO), it proceeds to step S17. The difference between pressure P1 and pressure P2 being less than the threshold N1 indicates that the rate of pressure drop of hydrogen gas downstream of the first shut-off valve 21 is slower than when the first shut-off valve 21 is normally closed. In step S17, the control device 40 determines that the first shut-off valve 21 is faulty. Thus, the first fault determination routine DF1 is completed when the determination result is output in step S16 or step S17.

[0034] <Processing method when the first fault detection routine DF1 is terminated> If the control device 40 determines in step S18 that an engine stall has occurred (step S18: YES), it executes the process in step S19.

[0035] In step S19, the control device 40 closes the second shut-off valve 22. As a result, all shut-off valves in the fuel supply system 10 are closed. As shown in Figure 3, after executing the process in step S19, the control device 40 terminates the series of processes shown in Figures 2 and 3. In this case, the control device 40 terminates the series of processes shown in Figures 2 and 3 without determining whether or not the first shut-off valve 21 is faulty. In other words, if the hydrogen engine 15 stops due to an engine stall while the first fault determination routine DF1 is being executed, the control device 40 cancels the first fault determination routine DF1.

[0036] <Processing method in the second fault detection routine DF2> As shown in Figure 3, once the first fault determination routine DF1 is completed, the control device 40 proceeds to step S20 and starts the second fault determination routine DF2. The second fault determination routine DF2 is a fault determination routine that determines whether or not there is a fault in the second shut-off valve 22. The processing from step S20 to step S26 shown in Figure 3 is the second fault determination routine DF2. In this way, the control device 40 executes the fault determination routine while sequentially changing the target shut-off valve from upstream.

[0037] In step S20, the control device 40 closes the second shut-off valve 22. In step S21, the control device 40 obtains pressure P3. Pressure P3 is the pressure of the hydrogen gas downstream of the second shut-off valve 22 immediately after the second shut-off valve 22 is closed. The control device 40 obtains pressure P3 from the second pressure sensor 32.

[0038] In step S22, the control device 40 determines whether a predetermined time t2 has elapsed after the second shut-off valve 22 has been closed. The predetermined time t2 is predetermined. If the control device 40 determines that a predetermined time t2 has not elapsed during the processing of step S22 (step S22: NO), it proceeds to step S28. In the processing of step S28, the control device 40 determines whether or not an engine stall occurred during the execution of the second fault determination routine DF2.

[0039] If the control device 40 determines in step S28 that no engine stall has occurred (step S28: NO), it executes the process in step S22 again. If the control device 40 determines that a predetermined time t2 has elapsed during the process in step S22 (step S22: YES), it proceeds to step S23. During the process in step S23, the control device 40 obtains the pressure P4. Pressure P4 is the pressure of the hydrogen gas downstream of the second shut-off valve 22 when a predetermined time t2 has elapsed after the second shut-off valve 22 has been closed. The control device 40 obtains the pressure P4 from the second pressure sensor 32.

[0040] In step S24, the control device 40 determines whether the difference between pressure P3 and pressure P4 is greater than or equal to the threshold N2. In the second fault detection routine DF2, the hydrogen gas flowing through the hydrogen piping 12 downstream of the second shut-off valve 22 is gradually consumed by the hydrogen engine 15 over a predetermined time t2. If the second shut-off valve 22 is not properly closed, the rate at which the hydrogen gas pressure downstream of the second shut-off valve 22 decreases is slower compared to when the second shut-off valve 22 is properly closed.

[0041] The difference between pressure P3 and pressure P4 reflects the rate at which the hydrogen gas pressure decreases downstream of the second shut-off valve 22. During steps S21 to S24, the control device 40 observes the rate at which the hydrogen gas pressure decreases downstream of the second shut-off valve 22.

[0042] The threshold N2, like the threshold N1, is predetermined by the manufacturer of the control device 40. The manufacturer of the control device 40 sets the threshold N2 based, for example, on the difference between pressure P3 and pressure P4, measured when the second shut-off valve 22 is properly closed.

[0043] In step S24, if the control device 40 determines that the difference between pressure P3 and pressure P4 is greater than or equal to the threshold N2 (step S24: YES), it proceeds to step S25. In step S25, the control device 40 determines that the second shut-off valve 22 is not malfunctioning.

[0044] If the control device 40 determines in step S24 that the difference between pressure P3 and pressure P4 is less than the threshold N2 (step S24: NO), it proceeds to step S26. The difference between pressure P3 and pressure P4 being less than the threshold N2 indicates that the rate of pressure drop of hydrogen gas downstream of the second shut-off valve 22 is slower than when the second shut-off valve 22 is normally closed. In step S26, the control device 40 determines that the second shut-off valve 22 is faulty. Thus, the second fault determination routine DF2 is completed when the determination result is output in step S25 or step S26.

[0045] When the first fault detection routine DF1 and the second fault detection routine DF2 are completed, all fault detection routines are finished. After all fault detection routines have finished, the control device 40 executes the process in step S27. In the process in step S27, the control device 40 stops the hydrogen engine 15. Then, the control device 40 completes the series of processes shown in Figures 2 and 3.

[0046] <Processing when the second fault detection routine DF2 is terminated> If the control device 40 determines that an engine stall has occurred during step S28 (step S28: YES), it terminates the series of processes shown in Figures 2 and 3. In this case, the control device 40 terminates the series of processes shown in Figures 2 and 3 without determining whether or not the second shut-off valve 22 is faulty. In other words, if the hydrogen engine 15 stops due to an engine stall while the second fault determination routine DF2 is being executed, the control device 40 cancels the second fault determination routine DF2. At this time, the control device 40 cancels the second fault determination routine DF2 with all the shut-off valves of the fuel supply system 10 closed.

[0047] <Processing performed by the control device 40 when an engine stall occurs while the vehicle is in motion> While the vehicle is in motion, the control device 40 operates the hydrogen engine 15 according to the vehicle's driving conditions. While the vehicle is in motion, the control device 40 keeps the first shut-off valve 21 and the second shut-off valve 22 open while the hydrogen engine 15 is running.

[0048] Figure 4 shows a series of processes performed by the control device 40 when an engine stall occurs while the vehicle is in motion. If an engine stall occurs while the vehicle is in motion, the control device 40 executes the process in step S31. At the moment the engine stall occurs while the vehicle is in motion, the first shut-off valve 21 and the second shut-off valve 22 are open. In the process of step S31, the control device 40 closes the first shut-off valve 21 and the second shut-off valve 22.

[0049] In step S32, the control device 40 determines whether the vehicle user has turned on the ignition switch (IG-ON). Turning on the ignition switch is an operation that requests the hydrogen engine 15 to start.

[0050] If the control device 40 determines in step S32 that the operation to turn on the ignition switch has not been performed (step S32: NO), it will execute the process of step S32 again. If the control device 40 determines in step S32 that the operation to turn on the ignition switch has been performed (step S32: YES), it will proceed to step S33.

[0051] In step S33, the control device 40 opens the first shut-off valve 21 and the second shut-off valve 22. As a result, hydrogen gas in the fuel tank 11 is supplied to the hydrogen engine 15.

[0052] In step S34, the control device 40 starts the hydrogen engine 15. This allows the control device 40 to restart the vehicle after an engine stall has occurred. After starting the hydrogen engine 15, the control device 40 completes the series of processes shown in Figure 4.

[0053] <Operation of this embodiment> If an engine stall occurs while the fault detection routine is running, the hydrogen gas in the hydrogen piping 12 will not be consumed. Therefore, if an engine stall occurs while the fault detection routine is running, the rate at which the hydrogen gas pressure downstream of the shut-off valve drops will be slower than if an engine stall does not occur. As a result, the control device 40 may incorrectly determine that the shut-off valve is faulty if an engine stall occurs while the fault detection routine is running. If an engine stall occurs while the fault detection routine is running, the control device 40 will terminate the fault detection routine.

[0054] <Effects of this embodiment> (1) The control device 40 can suppress the misjudgment of a shut-off valve failure when an engine stall occurs during the execution of the fault determination routine.

[0055] (2) The fuel supply system 10 is equipped with multiple shut-off valves. The control device 40 executes a fault determination routine with the shut-off valves downstream of the target shut-off valve open, changing the target shut-off valve sequentially from the upstream side. If the hydrogen engine 15 stops due to engine stall while the fuel supply system 10 is executing the fault determination routine, it closes all shut-off valves and cancels the fault determination routine.

[0056] Even if the injector stops injecting hydrogen gas due to an engine stall, hydrogen gas may still leak from the injector into the hydrogen engine 15. The control device 40 executes the fault detection routine with the shut-off valve downstream of the target shut-off valve open. Therefore, if an engine stall occurs during the fault detection routine, hydrogen gas that has passed through the open shut-off valve may leak from the injector into the non-operating hydrogen engine 15.

[0057] If an engine stall occurs while the fault detection routine is running, the control device 40 closes all shut-off valves in the fuel supply system 10. This allows the control device 40 to reduce the amount of hydrogen gas leaking from the injectors into the idle hydrogen engine 15.

[0058] (3) The fuel supply system 10 is equipped with a regulator 13 on the hydrogen piping 12 that adjusts the pressure of hydrogen gas supplied from the fuel tank 11 to the hydrogen engine 15. The fuel supply system 10 is equipped with a first shut-off valve 21 and a second shut-off valve 22 as shut-off valves. The first shut-off valve 21 is installed in the hydrogen piping 12 between the fuel tank 11 and the regulator 13. The second shut-off valve 22 is installed in the hydrogen piping 12 between the regulator 13 and the hydrogen engine 15. The control device 40 executes a first failure determination routine DF1, which is a failure determination routine targeting the first shut-off valve 21, while continuing to operate the hydrogen engine 15, with the first shut-off valve 21 closed and the second shut-off valve 22 open. The control device 40 executes a second failure determination routine DF2, which is a failure determination routine targeting the second shut-off valve 22, while continuing to operate the hydrogen engine 15, with both the first shut-off valve 21 and the second shut-off valve 22 closed. If the hydrogen engine 15 stops due to engine stall while the control device 40 is executing the first fault determination routine DF1, the control device 40 will keep the first shut-off valve 21 closed, close the second shut-off valve 22, and cancel the first fault determination routine DF1. If the hydrogen engine 15 stops due to engine stall while the control device 40 is executing the second fault determination routine DF2, the control device 40 will keep the first shut-off valve 21 and the second shut-off valve 22 closed and cancel the second fault determination routine DF2.

[0059] The fuel supply system 10 is equipped with two shut-off valves, a first shut-off valve 21 and a second shut-off valve 22, flanking the regulator 13. The control device 40 executes a fault detection routine for each of the first shut-off valve 21 and the second shut-off valve 22, and when an engine stall occurs, it stops the fault detection routine with both the first shut-off valve 21 and the second shut-off valve 22 closed. This allows the control device 40 to reduce the amount of hydrogen gas leaking from the injector into the hydrogen engine 15 when an engine stall occurs while the fault detection routine is being executed in the fuel supply system 10 equipped with the first shut-off valve 21 and the second shut-off valve 22.

[0060] (4) The control device 40 operates the hydrogen engine 15 according to the vehicle's driving conditions while the vehicle is in motion, and opens the shut-off valve while the hydrogen engine 15 is operating. When the hydrogen engine 15 stops due to engine stall while the vehicle is in motion, the shut-off valve is closed.

[0061] While the vehicle is in motion, the control device 40 opens the shut-off valve while the hydrogen engine 15 is running. Therefore, at the moment the hydrogen engine 15 stops due to engine stall while the vehicle is in motion, the shut-off valve is open.

[0062] The control device 40 closes the shut-off valve if an engine stall occurs while the vehicle is in motion. This allows the control device 40 to reduce the amount of hydrogen gas leaking from the injector into the idle hydrogen engine 15 when an engine stall occurs while the vehicle is in motion.

[0063] (5) After the control device 40 closes the shut-off valve in response to an engine stall that occurs while the vehicle is running, when the user requests the operation of the hydrogen engine 15, the control device 40 opens the shut-off valve and then starts the hydrogen engine 15.

[0064] The control device 40 operates the hydrogen engine 15 to allow the vehicle to resume operation after an engine stall occurs while the vehicle is running and the user requests engine operation. When the control device 40 operates the hydrogen engine 15, if the amount of hydrogen gas that the injector can inject is insufficient, the hydrogen engine 15 that has started operating may stall again.

[0065] The control device 40 opens the shut-off valve to allow the injector to utilize the hydrogen gas in the fuel tank 11, and then starts the hydrogen engine 15. This allows the control device 40 to suppress the occurrence of engine stalls when the hydrogen engine 15 restarts operation.

[0066] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0067] The fuel supply system 10 described above includes two shut-off valves: a first shut-off valve 21 and a second shut-off valve 22. The number of shut-off valves in the fuel supply system 10 is not limited to the above embodiment. The fuel supply system 10 may have three or more shut-off valves. Alternatively, the fuel supply system 10 may have only one shut-off valve.

[0068] The fuel supply system 10 described above has a regulator 13. The fuel supply system 10 does not necessarily have to have a regulator 13. The control device 40 described above changes the shut-off valves targeted by the fault detection routine sequentially from the upstream side. The manner in which the control device 40 changes the targets of the fault detection routine is not limited to the above embodiment. For example, the control device 40 may change the shut-off valves targeted by the fault detection routine sequentially from the downstream side.

[0069] The control device 40 does not need to close all shut-off valves if the hydrogen engine 15 stops due to engine stall while the fault determination routine is being executed. For example, the control device 40 does not need to close the second shut-off valve 22 if the hydrogen engine 15 stops due to engine stall while the first fault determination routine DF1 is being executed.

[0070] The control device 40 does not need to close the shut-off valve even if the hydrogen engine 15 stops due to engine stall while the vehicle is in motion. The control device 40 described above closes all shut-off valves when an engine stall occurs while the vehicle is in motion. The control device 40 may close only some of the shut-off valves among the multiple shut-off valves when an engine stall occurs while the vehicle is in motion.

[0071] The control device 40 may, after closing the shut-off valve in response to an engine stall that occurs while the vehicle is in motion, start the hydrogen engine 15 and then open the shut-off valve when the user requests the hydrogen engine 15 to start.

[0072] The operation that requests the operation of the hydrogen engine 15 is not limited to turning on the ignition switch. For example, the operation that requests the operation of the hydrogen engine 15 may be turning the engine key. For example, the operation that requests the operation of the hydrogen engine 15 may be pressing the starter switch. [Explanation of Symbols]

[0073] 10…Fuel supply system, 11…Fuel tank, 12…Hydrogen piping, 13…Regulator, 14…Rotation speed sensor, 15…Hydrogen engine, 21…First shut-off valve, 22…Second shut-off valve, 31…First pressure sensor, 32…Second pressure sensor, 40…Control device, DF1…First fault detection routine, DF2…Second fault detection routine, HS…High pressure section, LS…Low pressure section

Claims

1. A hydrogen engine that uses hydrogen gas as fuel, A fuel tank for storing the aforementioned hydrogen gas, A hydrogen pipeline that guides the hydrogen gas from the fuel tank to the hydrogen engine, A shut-off valve is provided in the middle of the hydrogen piping to shut off the supply of hydrogen gas from the fuel tank to the hydrogen engine, An injector for injecting the hydrogen gas into the hydrogen engine, Applicable to a fuel supply system comprising the above, and a control device capable of controlling the shut-off valve and the hydrogen engine, When a user of a vehicle equipped with the fuel supply system requests the shutdown of the hydrogen engine, the shut-off valve is closed, and while the hydrogen engine continues to operate, the rate of pressure drop of the hydrogen gas downstream of the shut-off valve is observed. If the rate of pressure drop is slow, a fault determination routine is executed to determine that the shut-off valve has not been properly closed. If the hydrogen engine stops due to engine stall while the fault detection routine is being executed, the fault detection routine is terminated. Control device.

2. The fuel supply system is equipped with multiple shut-off valves, and the fault determination routine is executed with the target shut-off valves downstream of the target shut-off valve open, changing the target shut-off valve sequentially from the upstream side. If the hydrogen engine stops due to engine stall while the fault detection routine is being executed, all of the shut-off valves are closed and the fault detection routine is terminated. The control device according to claim 1.

3. The fuel supply system is The hydrogen piping is provided with a regulator that adjusts the pressure of the hydrogen gas supplied from the fuel tank to the hydrogen engine. As the aforementioned shut-off valve, A first shut-off valve installed in the hydrogen piping between the fuel tank and the regulator, The hydrogen piping comprises a second shut-off valve installed in the portion between the regulator and the hydrogen engine, With the first shut-off valve closed and the second shut-off valve open, the fault determination routine targeting the first shut-off valve is executed while the hydrogen engine continues to operate. With the first shut-off valve and the second shut-off valve closed, the fault determination routine targeting the second shut-off valve is executed while the hydrogen engine continues to operate. If the hydrogen engine stops due to engine stall while the fault determination routine targeting the first shut-off valve is being executed, the second shut-off valve is closed while the first shut-off valve remains closed, and the fault determination routine targeting the first shut-off valve is terminated. If the hydrogen engine stops due to engine stall while the fault determination routine for the second shut-off valve is being executed, the fault determination routine targeting the second shut-off valve is terminated while the first and second shut-off valves remain closed. The control device according to claim 2.

4. While the vehicle is in motion, the hydrogen engine is operated according to the vehicle's driving conditions, and while the hydrogen engine is operating, the shut-off valve is opened. When the hydrogen engine stops due to engine stall while the vehicle is in motion, the shut-off valve is closed. A control device according to any one of claims 1 to 3.

5. After the shut-off valve is closed due to the engine stall that occurred while the vehicle was in motion, if the user requests the hydrogen engine to start, the shut-off valve is opened and the hydrogen engine is started. The control device according to claim 4.

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