Control device of fuel supply device

Abstract

To enable gas fuel which remains in a fuel supply passage at a stop of an internal combustion engine to be used at the next operation of the internal combustion engine.SOLUTION: A control device 100 sets as a control object, a fuel supply device 50 having: a fuel supply passage 70 connected to a fuel tank 90 and an injector 60; a main valve 91 opening and closing the fuel supply passage 70; a chamber 80 which can store gas; a portion of the fuel supply passage 70 at an injector 60 side rather than a main valve 91; a connection passage 77 connected to the chamber 80; and a sub-valve 81 opening and closing the connection passage 77. The control device performs: switching the main valve 91 to a closed state; switching the sub-valve 81 to an open state when acquiring a stop command of an internal combustion engine 10; and switching the sub-valve 81 to a closed state and switching the main valve 91 to an open state on condition that the inner pressure of a chamber 80 is equal to or lower than a set value when acquiring a start command of the internal combustion engine 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device for a fuel supply system. [Background technology]

[0002] The internal combustion engine disclosed in Patent Document 1 includes a cylinder and an intake passage connected to the cylinder. The fuel supply device disclosed in Patent Document 1 includes a fuel tank, a fuel passage, an injector, a shutoff valve, a pipe, and a discharge valve. The fuel tank stores gaseous fuel. The fuel passage connects the fuel tank and the injector. The injector supplies the gaseous fuel supplied from the fuel passage to the cylinder. The shutoff valve is located in the middle of the fuel passage. The shutoff valve opens and closes the flow path of the fuel passage. The pipe connects a portion of the fuel passage downstream of the shutoff valve to the intake passage. The discharge valve is located in the middle of the pipe. The discharge valve opens and closes the flow path of the pipe. In this fuel supply device, when the operation of the internal combustion engine is stopped, the shutoff valve is switched from an open state to a closed state. At this time, the portion of the fuel passage downstream of the shutoff valve remains high pressure with the gaseous fuel. In order to prevent this gaseous fuel from leaking into the cylinder via the injector, in the fuel supply device of Patent Document 1, the exhaust valve is switched from a closed state to an open state when the operation of the internal combustion engine is stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-107795 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology of Patent Document 1, when the exhaust valve is opened as the internal combustion engine stops operating, the gaseous fuel in the fuel passage can be discharged to the outside of the internal combustion engine through the piping and the intake passage. The gaseous fuel discharged to the outside of the internal combustion engine is wasted because it cannot be used for combustion the next time the internal combustion engine is operated. [Means for solving the problem]

[0005] A control device for a fuel supply device for solving the above problem controls a fuel supply device including an injector that injects gaseous fuel, a fuel tank that stores the gaseous fuel, a fuel supply passage connecting the fuel tank and the injector, a main valve that opens and closes the fuel supply passage, a chamber having a space capable of storing gas, a connecting passage that connects a portion of the fuel supply passage closer to the injector than the main valve and the chamber, and a sub-valve that opens and closes the connecting passage, and performs a first process of switching the main valve from an open state to a closed state and switching the sub-valve from a closed state to an open state when a command to stop the internal combustion engine is obtained, and a second process of switching the sub-valve from an open state to a closed state and switching the main valve from a closed state to an open state when a command to start the internal combustion engine is obtained, on condition that the internal pressure of the chamber is equal to or lower than a predetermined set value. Effect of the Invention

[0006] According to the above technical concept, the gaseous fuel remaining in the fuel supply passage when the internal combustion engine is stopped can be utilized the next time the internal combustion engine is operated. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of an internal combustion engine and a fuel supply device. [Diagram 2] FIG. 2 is a flowchart showing a processing procedure of the control processing. [Diagram 3] FIG. 3 is a schematic diagram showing one control mode of the fuel supply device. [Figure 4]FIG. 4 is a schematic diagram showing one control mode of the fuel supply device. [Diagram 5] FIG. 5 is a schematic diagram showing one control mode of the fuel supply device. [Figure 6] FIG. 6 is a schematic diagram showing one control mode of the fuel supply device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of a control device for a fuel supply system will be described with reference to the drawings. <Internal combustion engine> As shown in FIG. 1, a vehicle 500 includes an internal combustion engine 10. The internal combustion engine 10 is a drive source of the vehicle 500. The internal combustion engine 10 includes an engine body 11, a plurality of cylinders 12, and a crankshaft 13. The number of the cylinders 12 is, for example, four. The cylinders 12 are spaces partitioned in the engine body 11. In the cylinders 12, a mixture of intake air and gaseous fuel is burned. The crankshaft 13 rotates in response to the combustion of the mixture. The crankshaft 13 is connected to drive wheels 502 via an automatic transmission 501 or the like.

[0009] The internal combustion engine 10 is equipped with a plurality of spark plugs 15. One spark plug 15 is provided for each cylinder 12. The tip of each spark plug 15 is located in each cylinder 12. The spark plug 15 ignites the air-fuel mixture in each cylinder 12.

[0010] The internal combustion engine 10 has an intake passage 18. The intake passage 18 is a passage for introducing intake air into each cylinder 12. The intake passage 18 is connected to each cylinder 12. Although not shown, a throttle valve that adjusts the amount of intake air is provided midway through the intake passage 18.

[0011] The internal combustion engine 10 includes an exhaust passage 19. The exhaust passage 19 is a passage for discharging exhaust gas from each cylinder 12. The exhaust passage 19 is connected to each cylinder 12. <Fuel supply device> The vehicle 500 includes a fuel supply device 50 for supplying gaseous fuel to the internal combustion engine 10. The fuel supply device 50 includes a plurality of injectors 60. The injectors 60 are provided for each cylinder 12 of the internal combustion engine 10. The configuration of each injector 60 is the same. The injector 60 of this embodiment is a direct injection type that injects fuel directly into the cylinder 12 without passing through the intake passage 18. The injector 60 includes an injection port 61, a valve body 62, and an electromagnetic solenoid 63. For convenience, one of the plurality of injectors 60 is shown larger than the others in FIG. 1. Then, the injection port 61, the valve body 62, and the electromagnetic solenoid 63 are shown only for this injector 60. The injection port 61 is located in the cylinder 12. The injector 60 injects hydrogen, which is a gaseous fuel, through the injection port 61. The valve body 62 operates in response to the on / off state of the electromagnetic solenoid 63. When the electromagnetic solenoid 63 is in a non-energized state, the valve body 62 closes the injection port 61. In this case, the injector 60 does not inject gaseous fuel. When the electromagnetic solenoid 63 is in a powered state, the valve body 62 opens the injection port 61. In this case, the injector 60 injects gaseous fuel into the cylinder 12 through the injection port 61.

[0012] The fuel supply device 50 includes a fuel tank 90, a main passage 72, a delivery pipe 73, a plurality of branch passages 74, a main valve 91, and a pressure regulator 92. The branch passage 74 is provided for each injector 60. The fuel tank 90 stores hydrogen, which is a gaseous fuel. The main passage 72, the delivery pipe 73, and the plurality of branch passages 74 form a fuel supply passage 70. The main passage 72, the delivery pipe 73, and the plurality of branch passages 74 are formed by piping. The inside of each piping is a flow path through which the gaseous fuel can flow. The main passage 72 connects the fuel tank 90 and the delivery pipe 73. The delivery pipe 73 is connected to each injector 60 via the branch passage 74. The pressure regulator 92 is located midway through the main passage 72. The pressure regulator 92 adjusts and releases the pressure of the gaseous fuel. The main valve 91 is located on the fuel tank 90 side of the pressure regulator 92 in the main passage 72. The main valve 91 opens and closes the flow path of the main passage 72 under the control of a control device 100, which will be described later. The main valve 91 is a normally closed solenoid valve. That is, the main valve 91 is open when energized and closed when de-energized. When the main valve 91 is open, gas fuel in the fuel tank 90 is supplied to each injector 60. On the other hand, when the main valve 91 is closed, the supply of fuel from the fuel tank 90 to each injector 60 is cut off.

[0013] The fuel supply device 50 includes a chamber 80, a connection passage 77, and a sub-valve 81. The chamber 80 has a space capable of storing gas. The volume of the chamber 80 is smaller than the volume of the fuel tank 90. ​​The connection passage 77 is formed of a pipe. The inside of the connection passage 77 is a flow path through which gaseous fuel can flow. The connection passage 77 connects a portion of the main passage 72 on the delivery pipe 73 side relative to the pressure regulator 92 to the chamber 80. The sub-valve 81 is located midway through the connection passage 77. The sub-valve 81 opens and closes the flow path of the connection passage 77 under the control of a control device 100, which will be described later. The sub-valve 81 is a normally closed solenoid valve. That is, the sub-valve 81 is in an open state when energized, and is in a closed state when de-energized. When the sub-valve 81 is in an open state, gaseous fuel can flow between the chamber 80 and each injector 60. On the other hand, when the sub-valve 81 is in a closed state, the flow of gaseous fuel between the chamber 80 and each injector 60 is blocked.

[0014] The fuel supply device 50 includes a first pressure sensor 131 and a second pressure sensor 132. The first pressure sensor 131 detects the pressure P1 inside the delivery pipe 73 (hereinafter referred to as the internal pressure of the delivery pipe 73). The second pressure sensor 132 detects the pressure P2 inside the chamber 80 (hereinafter referred to as the internal pressure of the chamber). Each of these sensors repeatedly outputs a signal corresponding to the information detected by itself to the control device 100 described below.

[0015] <Other configurations> The vehicle 500 includes a vehicle speed sensor 112, an accelerator sensor 113, and an ignition switch 120. The vehicle speed sensor 112 detects the traveling speed of the vehicle 500 as a vehicle speed V. The accelerator sensor 113 detects the amount of depression of the accelerator pedal in the vehicle 500 as an accelerator operation amount ACC. Each of these sensors repeatedly outputs a signal corresponding to the information detected by itself to a control device 100 described later. The ignition switch 120 is a switch that allows a passenger to instruct starting and stopping of the internal combustion engine 10. The ignition switch 120 outputs a signal G corresponding to the operation of the passenger to the control device 100 described later.

[0016] <Control device> The vehicle 500 includes a control device 100. The control device 100 may be configured as one or more processors that execute various processes according to a computer program (software). The control device 100 may be configured as one or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), that execute at least a part of the various processes, or a circuit including a combination thereof. The processor includes a CPU 101 and a memory 102, such as a RAM and a ROM. The memory 102 stores program codes or instructions that are configured to cause the CPU 101 to execute processes. The memory 102, i.e., a computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer. The memory 102 includes an electrically rewritable non-volatile memory.

[0017] The control device 100 repeatedly acquires detection signals from the first pressure sensor 131, the second pressure sensor 132, the vehicle speed sensor 112, and the accelerator sensor 113. In addition, the control device 100 acquires a signal G from the ignition switch 120.

[0018] The control device 100 controls the internal combustion engine 10. For example, the control device 100 controls the ignition timing of each spark plug 15 and the fuel injection of each injector 60. In this way, the control device 100 repeats the combustion of the mixture in each cylinder 12. That is, the control device 100 operates the internal combustion engine 10. The control device 100 may also cause the internal combustion engine 10 to idle. Idle operation refers to operating the internal combustion engine 10 at the minimum rotation speed of the crankshaft 13 at which the internal combustion engine 10 can operate independently. With regard to the control of the fuel injection, the control device 10 actually controls the power supply to the electromagnetic solenoid 63.

[0019] The control device 100 controls the fuel supply device 50. The control device 100 controls the opening and closing of the main valve 91 and the sub valve 81. When controlling the opening and closing of the main valve 91 and the sub valve 81, the control device 100 actually controls the supply of power to the main valve 91 and the sub valve 81.

[0020] <Control processing> The control device 100 is capable of executing control processing for controlling the internal combustion engine 10 and the fuel supply device 50. The control device 100 starts the control processing when it acquires an ON signal, which is a signal in response to the ignition switch 120 being turned ON. The ON signal is a signal that indicates a start command for the internal combustion engine 10. Note that, at the time when the control device 100 starts the control processing, both the main valve 91 and the sub-valve 81 are in a closed state.

[0021] As shown in FIG. 2, when the control device 100 starts the control process, it first executes the process of step S110. In step S110, the control device 100 maintains the main valve 91, which is in a closed state, in the closed state. In addition, in step S110, the control device 100 switches the sub-valve 81, which is in a closed state, to an open state. The process of step S110 corresponds to the fourth process. That is, in the fourth process, when the control device 100 acquires an on signal, it switches the sub-valve 81 to an open state before performing the second process described below. After executing the process of step S110, the control device 100 advances the process to step S120. The control device 100 maintains the main valve 91 in a closed state and the sub-valve 81 in an open state until the subsequent step S140.

[0022] In step S120, the control device 100 starts normal operation of the internal combustion engine 10. In normal operation, the control device 100 repeatedly calculates the required torque of the internal combustion engine 10 based on the vehicle speed V and the accelerator operation amount ACC, and controls various parts of the internal combustion engine 10 so as to realize the calculated required torque. When the control device 100 starts normal operation of the internal combustion engine 10, the control device 100 advances the process to step S130. Note that the control device 100 may also cause the internal combustion engine 10 to idle as part of the normal operation.

[0023] In step S130, the control device 100 judges whether the internal pressure P2 of the chamber 80 is equal to or lower than the set value A. The control device 100 performs the judgment in step S130 by comparing the latest value of the internal pressure P2 of the chamber 80 acquired from the second pressure sensor 132 with the set value A. The control device 100 stores the set value A in advance. The set value A is a predetermined fixed value, and is determined in advance, for example, by an experiment or a simulation, as a value that can grasp that the gaseous fuel stored in the chamber 80 has been consumed. In addition, the set value A is a value lower than the minimum value that the internal pressure P1 of the delivery pipe 73 can take while the internal combustion engine 10 is operating, that is, under a situation in which fuel supply from each injector 60 is repeated. By determining such a value, the gaseous fuel in the fuel supply passage 70 quickly flows into the chamber 80 when the sub-valve 81 is switched to the open state in step S160 described later. If the internal pressure P2 of the chamber 80 is greater than the set value A (step S130: NO), the control device 100 performs the process of step S130 again. The control device 100 repeats the process of step S130 until the internal pressure P2 of the chamber 80 becomes equal to or less than the set value A. If the internal pressure P2 of the chamber 80 becomes equal to or less than the set value A (step S130: YES), the control device 100 advances the process to step S140.

[0024] In step S140, the control device 100 switches the main valve 91 from a closed state to an open state. The control device 100 also switches the sub-valve 81 from an open state to a closed state. The process of step S140 corresponds to the second process. That is, in the second process, when the control device 100 acquires an on signal, the control device 100 switches the main valve 91 to an open state and the sub-valve 81 to a closed state on the condition that the internal pressure P2 of the chamber 80 is equal to or lower than the set value A (step S130: YES). After executing the process of step S140, the control device 100 advances the process to step S150. The control device 100 maintains the main valve 91 in an open state and the sub-valve 81 in a closed state until the subsequent step S160.

[0025] In step S150, the control device 100 determines whether or not an off signal, which is a signal in response to the ignition switch 120 being turned off, has been acquired. The off signal is a signal that indicates a command to stop the internal combustion engine 10. If the control device 100 has not acquired an off signal (step S150: NO), the control device 100 performs the process of step S150 again. The control device 100 repeats the process of step S150 until an off signal is acquired. If the control device 100 acquires an off signal (step S150: YES), the process proceeds to step S160.

[0026] In step S160, the control device 100 switches the main valve 91 from an open state to a closed state. The control device 100 also switches the sub-valve 81 from a closed state to an open state. The process of step S160 corresponds to the first process. That is, in the first process, when the control device 100 acquires an off signal (step S150: YES), the control device 100 switches the main valve 91 to a closed state and switches the sub-valve 81 to an open state. After executing the process of step S160, the control device 100 advances the process to step S170. The control device 100 maintains the open state of the sub-valve 81 until the subsequent step S190. The control device 100 does not supply power to the main valve 91 until the next step S140 of the control process is performed. Therefore, the main valve 91 remains in the closed state until the next step S140 of the control process.

[0027] In step S170, the control device 100 transitions the internal combustion engine 10 from normal operation to idle operation. If the internal combustion engine 10 is in idle operation at the time when the control device 100 advances to step S170, the control device 100 continues the idle operation. After this, the control device 100 advances the process to step S180. In this way, the control device 100 continues the operation of the internal combustion engine 10 even after acquiring the OFF command.

[0028] In step S180, the control device 100 judges whether the internal pressure P2 of the chamber 80 is equal to or greater than a predetermined value B. The control device 100 performs the judgment in step S180 by comparing the latest value of the internal pressure P2 of the chamber 80 acquired from the second pressure sensor 132 with the predetermined value B. The control device 100 prestores the predetermined value B. The predetermined value B is a fixed value that is predefined as a value greater than the set value A. For example, in determining the predetermined value B, the amount of increase in the internal pressure P2 that may occur in the chamber 80 when the sub-valve 81 is switched to the open state is grasped in advance, for example, by an experiment or a simulation, in relation to the volume of the chamber 80 and the internal pressure P1 of the delivery pipe 73 during operation of the internal combustion engine 10. Then, taking such information into consideration, the set value A is determined as a value that can secure as much gas fuel as possible in the chamber 80 and that reliably reaches the internal pressure P2 when the internal pressure P2 of the chamber 80 rises in response to switching the sub-valve 81 to the open state. If the internal pressure P2 of the chamber 80 is less than the predetermined value B (step S180: NO), the control device 100 performs the process of step S180 again. The control device 100 repeats the process of step S180 until the internal pressure P2 of the chamber 80 becomes equal to or greater than the predetermined value B. Then, when the internal pressure P2 of the chamber 80 becomes equal to or greater than the predetermined value B (step S180: YES), the control device 100 advances the process to step S190.

[0029] In step S190, the control device 100 switches the sub-valve 81 from an open state to a closed state. The process of step S190 corresponds to the third process. That is, in the third process, the control device 100 acquires an OFF signal and performs the first process (step S160), and then switches the sub-valve 81 to a closed state on the condition that the internal pressure P2 of the chamber 80 is equal to or higher than a predetermined value B (step S180: YES). After executing the process of step S190, the control device 100 advances the process to step S200. Note that, after this, the control device 100 does not supply power to the sub-valve 81 until it performs step S110 of the next control process. Therefore, the sub-valve 81 remains in the closed state until step S110 of the next control process.

[0030] In step S200, the control device 100 judges whether the internal pressure P1 of the delivery pipe 73 is equal to or lower than the threshold value C. The control device 100 performs the judgment in step S200 by comparing the latest value of the internal pressure P1 acquired from the first pressure sensor 131 with the threshold value C. The control device 100 stores the threshold value C in advance. The threshold value C is determined in advance, for example, by an experiment or a simulation, as a value at which gas fuel does not leak from the injection port 61 of each injector 60 to the cylinder 12 when the injection port 61 of all the injectors 60 is closed. When the internal pressure P1 of the delivery pipe 73 is higher than the threshold value C (step S200: NO), the control device 100 performs the process of step S200 again. The control device 100 repeats the process of step S200 until the internal pressure P1 of the delivery pipe 73 becomes equal to or lower than the threshold value C. When internal pressure P1 of delivery pipe 73 becomes equal to or lower than threshold value C (step S200: YES), control device 100 advances the process to step S210.

[0031] In step S210, the control device 100 stops the operation of the internal combustion engine 10. That is, the control device 100 stops ignition by each spark plug 15 and stops fuel injection by each injector 60. As the control device 100 stops fuel injection, the injection port 61 of each injector 60 is closed. After this, the control device 100 ends the series of control processes. As described above, after performing the third process (step S190), the control device 100 stops the operation of the internal combustion engine 10 on the condition that the internal pressure P1 of the delivery pipe 73 is equal to or lower than the threshold value C (step S200: YES).

[0032] <Operation of the embodiment> The operation of this embodiment will be described with reference to Figures 3 to 6. In Figures 3 to 6, the main valve 91 and the sub-valve 81 in the open state are hatched. In Figures 3 to 6, the chamber 80 storing gaseous fuel is dotted. For convenience, the chamber 80 and the fuel tank 90 are shown to be the same size in Figures 3 to 6.

[0033] Now, assume that the state where NO is obtained in step S150 continues after the control device 100 performs the process of step S140. In this case, as shown in FIG. 3, the main valve 91 is open, while the sub-valve 81 is closed. Since the main valve 91 is open, gaseous fuel is supplied from the fuel tank 90 to the injector 60, as shown by the arrow L1 in FIG. 3. Then, as shown by the arrow F1 in FIG. 3, the control device 100 supplies this gaseous fuel to the cylinder 12 to operate the internal combustion engine 10. Note that since the sub-valve 81 is closed, the internal pressure P2 of the chamber 80 is maintained constant without increasing or decreasing.

[0034] After that, it is assumed that the control device 100 acquires an OFF signal (step S150: YES). Then, as shown in FIG. 4, the control device 100 switches the main valve 91 to the closed state while switching the sub-valve 81 to the open state (step S160). As described in relation to the set value A, in the state before switching the sub-valve 81 to the open state, the internal pressure P2 of the chamber 80 is lower than the internal pressure P1 of the delivery pipe 73. Therefore, when the control device 100 switches the sub-valve 81 to the open state, the gaseous fuel remaining in the fuel supply passage 70 flows into the chamber 80 as shown by the arrow L2 in FIG. 4. Accordingly, the gaseous fuel remaining in the fuel supply passage 70 decreases. In addition, the control device 100 continues to operate the internal combustion engine 10 by idling even after acquiring the OFF signal (step S170). Accordingly, as shown by the arrow F2 in FIG. 4, the gaseous fuel remaining in the fuel supply passage 70 is supplied to the cylinder 12 via the injector 60. This also causes the gaseous fuel remaining in the fuel supply passage 70 to decrease.

[0035] After that, when the internal pressure P2 of the chamber 80 rises to the predetermined value B or more (step S180: YES), the control device 100 switches the sub-valve 81 to a closed state (step S190) as shown in FIG. 5. As a result, the gaseous fuel that has flowed into the chamber 80 is retained in the chamber 80 as it is. Note that even at this time, the control device 100 continues the idling operation of the internal combustion engine 10. Therefore, the gaseous fuel remaining in the fuel supply passage 70 continues to be supplied to the cylinder 12 via the injector 60 as shown by the arrow FA in FIG. 5. Therefore, the gaseous fuel remaining in the fuel supply passage 70 further decreases. When the internal pressure P1 of the delivery pipe 73 becomes equal to or lower than the threshold value C (step S200: YES), the control device 100 stops the operation of the internal combustion engine 10 (step S210).

[0036] After that, it is assumed that the ignition switch 120 is turned on again. Then, the control device 100 starts the control process. Then, as shown in FIG. 6, the control device 100 switches the sub-valve 81 to an open state while keeping the main valve 91 in a closed state (step S110). Then, the control device 100 starts the operation of the internal combustion engine 10 (step S120). In this case, since the main valve 91 is in a closed state, fuel is not supplied from the fuel tank 90 to the injector 60. Meanwhile, as shown by an arrow L3 in FIG. 6, gaseous fuel is supplied from the chamber 80 to the injector 60. Then, as shown by an arrow F3 in FIG. 6, the control device 100 operates the internal combustion engine 10 by supplying the gaseous fuel to the cylinder 12.

[0037] Thereafter, when the internal pressure P2 of the chamber 80 falls below the set value A (S130: YES), the control device 100 switches the main valve 91 to an open state and switches the sub-valve 81 to a closed state (S140) as shown in Fig. 3. Then, as shown by the arrow L1 in Fig. 3, gaseous fuel is supplied from the fuel tank 90 to the injector 60. The control device 100 operates the internal combustion engine 10 with this gaseous fuel.

[0038] Here, the control device 100 basically causes the internal combustion engine 10 to idle for a while after starting the operation of the internal combustion engine 10 in step S120. The amount of gaseous fuel required during this idle operation is limited. Therefore, the fuel supply device 50 can sufficiently cover the amount of gaseous fuel required by the internal combustion engine 10 immediately after the internal combustion engine 10 starts operating with the gaseous fuel stored in the chamber 80. Now, during the idle operation after the internal combustion engine 10 starts operating, the determination in step S130 quickly becomes YES. Then, the main valve 91 is quickly opened and fuel supply from the fuel tank 90 is started. Therefore, the fuel supply device 50 can always cover the amount of gaseous fuel required by the internal combustion engine 10.

[0039] <Effects of the embodiment> (1) As described in FIG. 4, when the control device 100 receives an OFF signal, it closes the main valve 91 and opens the sub-valve 81. As a result, the gas fuel remaining in the fuel supply passage 70 flows into the chamber 80. On the other hand, as described in FIG. 6, when the control device 100 receives an ON signal, it opens the sub-valve 81 while keeping the main valve 91 closed. As a result, the gas fuel stored in the chamber 80 is supplied to the injector 60, not from the fuel tank 90. ​​Then, this gas fuel is consumed during the operation of the internal combustion engine 10. Therefore, in the configuration of this embodiment, the gas fuel remaining in the fuel supply passage 70 when the OFF signal is received can be used the next time the internal combustion engine 10 is operated, without being wasted.

[0040] (2) In this embodiment, in relation to (3) described later, the operation of the internal combustion engine 10 continues even after the OFF signal is acquired. As described in FIG. 5, during the operation of the internal combustion engine 10, the control device 100 switches the sub-valve 81 to a closed state when gaseous fuel flows into the chamber 80. By switching the sub-valve 81 to a closed state, the gaseous fuel that has flowed into the chamber 80 remains in the chamber 80 without being consumed even if the operation of the internal combustion engine 10 continues. The gaseous fuel that has flowed into the chamber 80 is retained in the chamber 80 until the next operation of the internal combustion engine 10. In other words, in the configuration of this embodiment, the gaseous fuel remaining in the fuel supply passage 70 can be reliably secured as fuel for the next operation of the internal combustion engine 10.

[0041] (3) In this embodiment, the operation of the internal combustion engine 10 continues even after the OFF signal is acquired. This causes the gaseous fuel remaining in the fuel supply passage 70 to be consumed by the internal combustion engine 10. Then, when the internal pressure of the fuel supply passage 70 becomes low, the operation of the internal combustion engine 10 is stopped. Therefore, after the internal combustion engine 10 is stopped, the internal pressure of the fuel supply passage 70 is in a low state. Therefore, it is possible to effectively suppress the leakage of gaseous fuel from the injector 60 to the cylinder 12 after the internal combustion engine 10 is stopped.

[0042] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0043] With regard to the process of step S130, it is not essential to refer to the internal pressure P2 of the chamber 80 itself in determining whether the internal pressure P2 of the chamber 80 is equal to or lower than the set value A. For example, the time required for the internal pressure P2 of the chamber 80 to become equal to or lower than the set value A after the process of step S110 is executed may be determined in advance, for example, by experiment or simulation, and the determination of step S130 may be determined as YES when such time has elapsed.

[0044] As in the above modification, in determining in step S180 whether the internal pressure P2 of the chamber 80 is equal to or greater than the predetermined value B, the time that has elapsed since the process of step S160 was executed may be used.

[0045] As in the above modification, in determining in step S200 whether the internal pressure P1 of the delivery pipe 73 is equal to or lower than the threshold value C, the time that has elapsed since the process of step S190 was performed may be used.

[0046] The operation of the internal combustion engine 10 may be stopped at the time when the OFF signal is acquired. Even in this case, the gaseous fuel can be flowed into the chamber 80 by switching the main valve 91 to the closed state and the sub-valve 81 to the open state in step S160. Then, the gaseous fuel can be retained in the chamber 80 by switching the sub-valve 81 to the closed state thereafter in step S180. In this case, the internal pressure of the fuel supply passage 70 is reduced by the amount of the gaseous fuel retained in the chamber 80, so that the gaseous fuel remaining in the fuel supply passage 70 can be prevented from leaking into the cylinder 12 via the injector 60. In addition, by switching the sub-valve 81 to the closed state and retaining the gaseous fuel in the chamber 80, the gaseous fuel that can be used the next time the internal combustion engine 10 is operated can be secured.

[0047] As in the above modification, in addition to stopping the internal combustion engine 10 when the OFF signal is acquired, the processes of steps S180 and S190 may be eliminated. That is, after the gas fuel is flowed into the chamber 80, the sub-valve 81 may be left open. Then, the ON signal may be acquired next. In this case, in step S110 of the next control process, the sub-valve 81 may be maintained open. For example, if a normally open solenoid valve is used as the sub-valve 81, the sub-valve 81 is maintained open even after the control device 100 finishes the control process and transitions to a sleep state, and the ON signal is acquired. Now, even if the sub-valve 81 is left open after the gas fuel is flowed into the chamber 80, as in this modification, the following effect can be obtained. That is, the internal pressure of the fuel supply passage 70 is reduced as long as the gas fuel is flowed into the chamber 80, so that the gas fuel remaining in the fuel supply passage 70 can be prevented from leaking into the cylinder 12 via the injector 60. Even if the sub-valve 81 is left open after the gaseous fuel has flowed into the chamber 80, most of the gaseous fuel that has once flowed into the chamber 80 may remain in the chamber 80. Therefore, this gaseous fuel can be used the next time the internal combustion engine 10 is operated.

[0048] The values ​​to which the set value A and the predetermined value B are set are not limited to those in the above embodiment, and can be changed as appropriate. The set value A may be set in consideration of the fact that it is possible to determine in step S130 that the gaseous fuel stored in the chamber 80 has been consumed, and that the gaseous fuel is caused to flow into the chamber 80 when the sub-valve 81 is opened in step S160. The predetermined value B may be set in consideration of the fact that it is possible to determine in step S180 that the gaseous fuel has flowed into the chamber 80.

[0049] The period from when the ignition switch 120 is turned on to when it is turned off is called one trip. During this one trip, the control device 100 may automatically stop and automatically restart the internal combustion engine 10 when the vehicle 500 is temporarily stopped. The control device 100 may be configured to obtain a stop command for the internal combustion engine 10 when performing such an automatic stop, and to obtain a start command for the internal combustion engine 10 when performing an automatic restart. Then, during such an automatic stop of the internal combustion engine 10, a first process may be performed in which the main valve 91 is switched to a closed state and the sub-valve 81 is switched to an open state. Also, during an automatic restart of the internal combustion engine 10, a second process may be performed in which the sub-valve 81 is switched to a closed state and the main valve 91 is switched to an open state, on the condition that the internal pressure P2 of the chamber 80 is equal to or lower than a set value A.

[0050] The overall configuration of the fuel supply device 50 and the internal combustion engine 10 is not limited to the example of the above embodiment. For example, the injector 60 may be of a type that supplies gaseous fuel to the cylinder 12 via the intake passage 18. The main valve 91 and the sub-valve 81 are not limited to solenoid valves, and may be any valve that can be opened and closed by the control device 100.

[0051] · Gaseous fuels are not limited to hydrogen. A control device that controls the fuel supply device 50 may be provided separately from the control device that controls the internal combustion engine 10. Even in this case, if the control device that controls the fuel supply device 50 is configured to receive start and stop commands for the internal combustion engine 10, the control device can open and close the main valve 91 and the sub-valve 81 in accordance with the start and stop of the internal combustion engine 10. [Explanation of symbols]

[0052] 10: internal combustion engine 60: injector 70: fuel supply passage 77: connecting passage 80: chamber 81: sub-valve 90: fuel tank 91: main valve 100: control device

Claims

1. a fuel supply device to be controlled, the fuel supply device comprising: an injector for injecting gaseous fuel; a fuel tank for storing the gaseous fuel; a fuel supply passage connecting the fuel tank and the injector; a main valve for opening and closing the fuel supply passage; a chamber having a space capable of storing gas; a connecting passage connecting a portion of the fuel supply passage on the injector side relative to the main valve and the chamber; and a sub-valve for opening and closing the connecting passage; a first process for switching the main valve from an open state to a closed state and switching the sub-valve from a closed state to an open state when a stop command for the internal combustion engine is acquired; a second process of switching the sub-valve from an open state to a closed state and switching the main valve from a closed state to an open state, on condition that the internal pressure of the chamber is equal to or lower than a predetermined set value, when a start command for the internal combustion engine is obtained. A control device for a fuel supply system.

2. a third process of switching the sub-valve from an open state to a closed state on condition that the internal pressure of the chamber is equal to or greater than a predetermined value that is greater than the set value, after the first process is performed in response to a command to stop the internal combustion engine; When a start command for the internal combustion engine is obtained, a fourth process is performed to switch the sub-valve from a closed state to an open state prior to performing the second process. The control device for a fuel supply system according to claim 1.

3. In addition to the fuel supply device, the internal combustion engine is also a control target; Continue operating the internal combustion engine even after receiving a command to stop the internal combustion engine; After performing the third process, the operation of the internal combustion engine is stopped on the condition that an internal pressure in a portion of the fuel supply passage on the injector side relative to the main valve is equal to or lower than a predetermined threshold value. The control device for a fuel supply system according to claim 2.

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