Fuel supply device

Abstract

To provide a fuel supply device capable of supplying oil into a delivery pipe without complicating a device configuration.SOLUTION: A fuel supply device 15 comprises a fuel tank 21, a delivery pipe 22 in which gas fuel to be supplied to a fuel injection valve 14 is stored, a supply passage 23 through which the fuel gas supplied from the fuel tank 21 to the delivery pipe 22 flows, a shut-off valve 26 provided in the supply passage 23, an oil supply device 30 that supplies oil to a downstream portion 23A of the supply passage 23, and a control unit 50. The control unit 50 executes oil supply processing during operation of an internal combustion engine 10 to close the shut-off valve 26 to stop the supply of the gas fuel to the delivery pipe 22, and to supply the oil to the downstream portion 23A by the oil supply device 30 under the situation where the pressure in the delivery pipe 22 drops.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fuel supply device that supplies gas fuel to an internal combustion engine using gas fuel as fuel.

Background Art

[0002] Patent Document 1 discloses a supply device that supplies gas fuel to an internal combustion engine using gas fuel as fuel. The supply device includes a fuel injection valve, a pipe through which the fuel supplied to the fuel injection valve flows, and an oil pump that supplies oil into the pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When supplying oil into the pipe under a situation where the fuel pressure in the pipe is high, it is necessary to increase the pressure of the oil. In order to increase the pressure of the oil in this way, it is necessary to provide a configuration for increasing the pressure of the oil. In this case, the configuration of the supply device becomes complicated.

Means for Solving the Problems

[0005] The fuel supply device for solving the above problems is a device provided in an internal combustion engine equipped with a fuel injection valve for injecting gas fuel. The fuel supply device includes a fuel tank for storing the high-pressure gas fuel, a delivery pipe for storing the gas fuel supplied to the fuel injection valve, a supply passage through which the gas fuel flows from the fuel tank to the delivery pipe, a shut-off valve provided in the supply passage and closed when the supply of the gas fuel to the delivery pipe is stopped, an oil supply device for supplying oil to a downstream portion which is a portion between a connection portion with the delivery pipe and a position of the shut-off valve in the supply passage, and a control device for controlling the shut-off valve and the oil supply device. The control device stops the supply of the gas fuel to the delivery pipe by closing the shut-off valve during operation of the internal combustion engine, and executes an oil supply process in which the oil supply device supplies the oil to the downstream portion under a situation where the pressure in the delivery pipe has dropped compared to before the shut-off valve is closed.

Advantages of the Invention

[0006] The above fuel supply device can supply oil into the delivery pipe without complicating the device configuration.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment of the fuel supply device will be described with reference to FIGS. 1 to 3. <Internal combustion engine> FIG. 1 illustrates an internal combustion engine 10 mounted on a vehicle. The internal combustion engine 10 is an internal combustion engine that uses gas fuel as fuel. An example of the gas fuel is hydrogen gas.

[0009] The internal combustion engine 10 includes a plurality of cylinders 11 and a crankshaft 12. Pistons are respectively arranged in the plurality of cylinders 11. The crankshaft 12 rotates as the pistons reciprocate in the plurality of cylinders 11.

[0010] The internal combustion engine 10 includes an intake passage 13, a plurality of fuel injection valves 14, a fuel supply device 15, a plurality of spark plugs 16, and an exhaust passage 17. The intake passage 13 is connected to the plurality of cylinders 11. The intake passage 13 is a passage through which air introduced into the plurality of cylinders 11 flows.

[0011] The plurality of fuel injection valves 14 respectively inject the gas fuel supplied from the fuel supply device 15. In the example shown in FIG. 1, an in-cylinder injection valve that directly injects gas fuel into the cylinder 11 is adopted as the fuel injection valve 14. The internal combustion engine 10 may be provided with a port injection valve that injects gas fuel into the intake passage 13 as the fuel injection valve 14. The configuration of the fuel supply device 15 will be described later.

[0012] The plurality of spark plugs 16 ignite the air-fuel mixture containing air and gas fuel in the cylinder 11. As a result, the air-fuel mixture burns in the plurality of cylinders 11. Exhaust gas is generated in the plurality of cylinders 11 due to the combustion of the air-fuel mixture. The exhaust gas in the plurality of cylinders 11 is discharged into the exhaust passage 17.

[0013] <Fuel supply device> The fuel supply device 15 includes a fuel tank 21, a delivery pipe 22, and a supply passage 23. The fuel tank 21 stores high-pressure gas fuel. The delivery pipe 22 temporarily stores the gas fuel to be supplied to the plurality of fuel injection valves 14. The plurality of fuel injection valves 14 are respectively connected to the delivery pipe 22. The supply passage 23 is a passage through which the gas fuel supplied from the fuel tank 21 to the delivery pipe 22 flows. The upstream end of the supply passage 23 is connected to the fuel tank 21. The downstream end of the supply passage 23 is connected to the delivery pipe 22.

[0014] The fuel supply device 15 includes a pressure reducing valve 25 and a shut-off valve 26. The pressure reducing valve 25 is provided in the supply passage 23. An example of the pressure reducing valve 25 is an electronically controlled solenoid valve. By controlling the opening degree of the pressure reducing valve 25 and the length of the valve opening period of the pressure reducing valve 25, the pressure of the gas fuel supplied to the delivery pipe 22 through the supply passage 23 can be adjusted.

[0015] The shut-off valve 26 is provided in a portion of the supply passage 23 between the position of the pressure reducing valve 25 and the connection portion with the delivery pipe 22. An example of the shut-off valve 26 is an electronically controlled solenoid valve. When the shut-off valve 26 is open, the gas fuel pressure-regulated by the pressure reducing valve 25 is supplied to the delivery pipe 22 through the supply passage 23. On the other hand, when the shut-off valve 26 is closed, the supply of gas fuel to the delivery pipe 22 through the supply passage 23 is stopped.

[0016] The fuel supply device 15 includes an oil supply device 30. The oil supply device 30 is a device that supplies the oil stored in the oil tank 100 to the delivery pipe 22. The oil supply device 30 has an oil pump 31, an oil supply passage 32, and an oil injection valve 33. The oil pump 31 pumps up the oil from the oil tank 100 and discharges the oil into the oil supply passage 32. The oil pump 31 operates so that the pressure of the oil in the oil supply passage 32 is maintained at a predetermined pressure.

[0017] The oil supply passage 32 is a passage through which the oil pumped up by the oil pump 31 flows. The oil supply passage 32 is connected to the downstream portion 23A of the supply passage 23. The downstream portion 23A is a portion of the supply passage 23 between the connection portion with the delivery pipe 22 and the position of the shut-off valve 26. The oil injection valve 33 is provided in the oil supply passage 32. The oil injection valve 33 can inject the oil in the oil supply passage 32 into the downstream portion 23A. That is, the oil supply device 30 is configured to supply oil to the downstream portion 23A.

[0018] The fuel supply device 15 includes a plurality of sensors that output signals according to the detection results to a control device 50 described later. The plurality of sensors includes a hydraulic pressure sensor 41, an oil temperature sensor 42, a fuel pressure sensor 43, and a fuel temperature sensor 44. The hydraulic pressure sensor 41 detects the pressure of the oil in the oil supply passage 32. The oil temperature sensor 42 detects the temperature of the oil in the oil supply passage 32. The fuel pressure sensor 43 detects the pressure of the gaseous fuel in the delivery pipe 22. The fuel temperature sensor 44 detects the temperature of the gaseous fuel in the delivery pipe 22.

[0019] Note that the pressure of the oil based on the detection signal of the oil temperature sensor 42 is referred to as "oil pressure Poil". The temperature of the oil based on the detection signal of the oil temperature sensor 42 is referred to as "oil temperature TPoil". The pressure of the gaseous fuel based on the detection signal of the fuel pressure sensor 43 is referred to as "fuel pressure Pdf". The temperature of the gaseous fuel based on the detection signal of the fuel temperature sensor 44 is referred to as "fuel temperature TPdf".

[0020] The fuel supply device 15 includes a control device 50 that controls the pressure reducing valve 25, the shut-off valve 26, and the oil supply device 30. The control device 50 has a processing circuit 51. An example of the processing circuit 51 is an electronic control device. In this case, the processing circuit 51 has a CPU 52, a first memory 53, and a second memory 54. The first memory 53 stores a control program executed by the CPU 52. The operation results of the CPU 52 and the like are stored in the second memory 54. By the CPU 52 executing the control program in the first memory 53, the processing circuit 51 controls the pressure reducing valve 25, the shut-off valve 26, and the oil supply device 30.

[0021] <Oil supply process> In an internal combustion engine that uses a liquid fuel such as gasoline as fuel, the portion from the delivery pipe to the injection port of the fuel injection valve is lubricated by the liquid fuel. However, the lubricity of the gas fuel that is the fuel of the internal combustion engine 10 is lower than that of the liquid fuel.

[0022] Therefore, the control device 50 executes an oil supply process of supplying oil from the oil supply device 30 to the delivery pipe 22. The control device 50 executes the oil supply process during the operation of the internal combustion engine 10. In the oil supply process, the control device 50 stops the supply of gas fuel to the delivery pipe 22 by closing the shut-off valve 26. When the pressure in the delivery pipe 22 drops below that before the shut-off valve 26 is closed, the control device 50 causes the oil supply device 30 to supply oil to the downstream portion 23A. Specifically, the control device 50 reduces the fuel pressure Pdf until the fuel pressure Pdf becomes less than the oil pressure Poil. In this state, the control device 50 supplies the oil in the oil supply passage 32 to the downstream portion 23A by opening the oil injection valve 33. After that, when the control device 50 terminates the oil supply process, it stops the supply of oil to the downstream portion 23A by the oil supply device 30 and increases the fuel pressure Pdf by opening the shut-off valve 26.

[0023] <Flow of the process when supplying oil to the delivery pipe> Referring to FIG. 2, the flow of the process executed by the processing circuit 51 when executing the oil supply process will be described. The processing circuit 51 repeatedly executes the processing routine shown in FIG. 2.

[0024] In step S11, the processing circuit 51 determines whether or not the internal combustion engine 10 is in operation. When the operating state of the internal combustion engine 10 is an operating state in which gaseous fuel is injected from a plurality of 14, it is regarded that the internal combustion engine 10 is in operation. When the operating state of the internal combustion engine 10 is an operating state in which the injection of gaseous fuel from a plurality of fuel injection valves 14 is stopped, it is regarded that the internal combustion engine 10 is not in operation. When the processing circuit 51 determines that the internal combustion engine 10 is in operation (S11: YES), the process proceeds to step S13. On the other hand, when the processing circuit 51 determines that the internal combustion engine 10 is not in operation (S11: NO), this processing routine is temporarily terminated.

[0025] In step S13, the processing circuit 51 determines whether or not a predetermined period PP has elapsed since the last execution of the oil supply process. When the oil supply process is executed, a sufficient amount of oil exists in the delivery pipe 22. However, the oil is injected from the fuel injection valve 14 together with the gaseous fuel. Therefore, the amount of oil in the delivery pipe 22 gradually decreases due to the operation of the fuel injection valve 14. Therefore, a criterion for determining whether or not a sufficient amount of oil remains in the delivery pipe 22 for lubrication between the delivery pipe 22 and the injection port of the fuel injection valve 14 is preset as the predetermined period PP.

[0026] When the processing circuit 51 determines that the predetermined period PP has elapsed since the last execution of the oil supply process (S13: YES), the process proceeds to step S15. On the other hand, when the processing circuit 51 determines that the predetermined period PP has not elapsed since the last execution of the oil supply process (S13: NO), this processing routine is temporarily terminated.

[0027] In step S15, the processing circuit 51 determines whether it is permitted to decrease the fuel pressure Pdf. For example, when at least one of the following conditions (A1), (A2), and (A3) is satisfied, the processing circuit 51 determines that it is permitted to decrease the fuel pressure Pdf. On the other hand, when none of the following conditions (A1), (A2), and (A3) is satisfied, the processing circuit 51 determines that it is not permitted to decrease the fuel pressure Pdf.

[0028] (A1) The internal combustion engine 10 is idling. (A2) It is before the start of the decrease in the rotational speed of the crankshaft 12. The rotational speed of the crankshaft 12 corresponds to the "rotational speed of the internal combustion engine 10".

[0029] (A3) It is before the operation of the internal combustion engine 10 stops. When the internal combustion engine 10 is idling, the injection amount of the gaseous fuel of the fuel injection valve 14 is smaller compared to the case where the internal combustion engine 10 is under high load operation. Therefore, when the internal combustion engine 10 is idling, even if the fuel pressure Pdf is low, an appropriate amount of gaseous fuel can be injected from the fuel injection valve 14.

[0030] When decreasing the rotational speed of the internal combustion engine 10, the injection amount of the gaseous fuel of the fuel injection valve 14 is smaller compared to the case of increasing the rotational speed of the internal combustion engine 10. Therefore, when decreasing the rotational speed of the internal combustion engine 10, even if the fuel pressure Pdf is low, an appropriate amount of gaseous fuel can be injected from the fuel injection valve 14.

[0031] When the operation of the internal combustion engine 10 stops, the injection of the gaseous fuel of the fuel injection valve 14 also stops. Therefore, before the operation of the internal combustion engine 10 stops, even if the fuel pressure Pdf is low, an appropriate amount of gaseous fuel can be injected from the fuel injection valve 14.

[0032] Note that when the vehicle on which the internal combustion engine 10 is mounted is a hybrid vehicle, the processing circuit 51 can know the timing at which the operation of the internal combustion engine 10 stops. When the processing circuit 51 determines that it is permitted to decrease the fuel pressure Pdf (S15: YES), the process proceeds to step S17. On the other hand, when the processing circuit 51 determines that it is not permitted to decrease the fuel pressure Pdf (S15: NO), the present processing routine is temporarily terminated.

[0033] In step S17, the processing circuit 51 executes an oil supply process. Specifically, in step S19, the processing circuit 51 closes the shut-off valve 26. Since the gas fuel in the delivery pipe 22 is consumed by the operation of the plurality of fuel injection valves 14, the processing circuit 51 can start to decrease the fuel pressure Pdf.

[0034] In the next step S21, the processing circuit 51 calculates a supply time TS. The supply time TS is the length of time for supplying oil into the delivery pipe 22 by the oil supply device 30. The processing circuit 51 sets a longer time as the supply time TS as long as it can be inferred that the remaining amount of oil in the delivery pipe 22 is small. In this case, the processing circuit 51 acquires a parameter correlated with the remaining amount of oil in the delivery pipe 22. Then, the processing circuit 51 sets a longer time as the supply time TS as the remaining amount of oil inferred from the parameter is smaller. Examples of such parameters include the elapsed time since the previous end point of the oil supply process, the travel distance of the vehicle since the previous end point of the oil supply process, and the total number of operations of the plurality of fuel injection valves 14 since the previous end point of the oil supply process.

[0035] Also, when gas fuel is injected from the fuel injection valve 14, the lower the oil temperature TPoil, the less likely the oil is to be injected from the fuel injection valve 14. Therefore, the processing circuit 51 estimates the remaining amount of oil in the delivery pipe 22 based on the transition of the oil temperature TPoil since the previous end point of the oil supply process or the average value of the oil temperature TPoil since that time. Then, the processing circuit 51 may set a longer time as the supply time TS as the estimated value of the remaining amount of oil is smaller.

[0036] When the processing circuit 51 calculates the supply time TS, it proceeds to step S23. In step S23, the processing circuit 51 executes control of the oil injection valve 33 and the shut-off valve 26.

[0037] Referring to FIG. 3, the processing in step S23 will be described. When the combustion pressure Pdf is equal to or higher than the target combustion pressure Pdfth, the processing circuit 51 does not cause the oil injection valve 33 to inject oil. The target combustion pressure Pdfth is set to satisfy both being higher than the lower limit of the combustion pressure Pdf at which the fuel injection valve 14 can inject gaseous fuel and being lower than the oil pressure Poil.

[0038] When the combustion pressure Pdf becomes lower than the target combustion pressure Pdfth, the processing circuit 51 starts the injection of oil by the oil injection valve 33. After starting the injection of oil by the oil injection valve 33, the processing circuit 51 controls the pressure reducing valve 25 so that the combustion pressure Pdf is included in the target combustion pressure region APdf. That is, when the combustion pressure Pdf approaches the lower limit of the target combustion pressure Pdfth, the pressure reducing valve 25 is opened to increase the combustion pressure Pdf. When the combustion pressure Pdf approaches the upper limit of the target combustion pressure region APdf, the processing circuit 51 closes the pressure reducing valve 25. During the period when the processing circuit 51 causes the oil injection valve 33 to inject oil, the processing circuit 51 adjusts the combustion pressure Pdf by repeatedly opening and closing the pressure reducing valve 25.

[0039] The flow rate of oil from the oil supply passage 32 to the downstream portion 23A when the oil injection valve 33 is open varies depending on the difference between the oil pressure Poil and the combustion pressure Pdf and the oil temperature TPoil. Therefore, the processing circuit 51 controls the energization time of the solenoid of the oil injection valve 33 based on the difference between the oil pressure Poil and the combustion pressure Pdf and the oil temperature TPoil.

[0040] Returning to FIG. 2, in step S25, the processing circuit 51 determines whether the end condition of the oil supply process is satisfied. If the elapsed time from the start time of the current oil supply process has not reached the supply time TS, it can be considered that the end condition is not satisfied. On the other hand, if the elapsed time from the start time has reached the supply time TS, it can be considered that the end condition is satisfied. When the processing circuit 51 determines that the end condition is not satisfied (S25: NO), the process proceeds to step S23. That is, the processing circuit 51 continues the oil supply process. On the other hand, when the processing circuit 51 determines that the end condition is satisfied (S25: YES), it stops the oil injection of the oil injection valve 33 and ends the oil supply process.

[0041] When the processing circuit 51 ends the oil supply process, the process proceeds to step S27. In step S27, the processing circuit 51 opens the shut-off valve 26. Then, the processing circuit 51 temporarily ends this processing routine.

[0042] <Operations and Effects of the Present Embodiment> Referring to FIG. 3, the operations and effects of the present embodiment will be described. In the example shown in FIG. 3, the internal combustion engine 10 is idling.

[0043] As shown in FIGS. 3(a) and (b), the timing T11 during which the internal combustion engine 10 is operating is the time when a predetermined period PP has elapsed since the previous execution of the oil supply process. Since the internal combustion engine 10 is idling, the processing circuit 51 starts the oil supply process. Then, the shut-off valve 26 is closed.

[0044] Even in this state, in order to maintain the internal combustion engine 10 in an idling state, each of the plurality of fuel injection valves 14 injects gaseous fuel. Therefore, the fuel pressure Pdf, which is the pressure of the gaseous fuel in the delivery pipe 22, gradually decreases. At timing T12, the fuel pressure Pdf becomes lower than the target fuel pressure Pdfth. Therefore, the processing circuit 51 starts the injection of oil from the oil injection valve 33. Then, oil is supplied from the oil supply device 30 to the downstream portion 23A. As a result, oil is supplied into the delivery pipe 22. As a result, the lubricity between the delivery pipe 22 and the injection port of the fuel injection valve 14 is maintained by the oil. Therefore, the wear of the components of the fuel injection valve 14 is suppressed from progressing.

[0045] At a subsequent timing T13, the end condition of the oil supply process is satisfied. Then, since the processing circuit 51 ends the oil supply process, the injection of oil from the oil injection valve 33 ends. Also, the shut-off valve 26 is opened. As a result, the fuel pressure Pdf increases compared to during the execution of the oil supply process.

[0046] In the present embodiment, the following effects can be obtained. (1) The oil supply device 30 supplies oil into the delivery pipe 22 after the fuel pressure Pdf has sufficiently decreased. That is, the oil supply device 30 does not have to supply oil into the delivery pipe 22 when the fuel pressure Pdf is high. Therefore, the oil supply device 30 does not have to include a high-pressure pump that pressurizes the oil in order to inject the high-pressure oil from the oil injection valve 33. Therefore, the fuel supply device 15 can supply oil into the delivery pipe 22 without complicating the device configuration.

[0047] (2) The oil supply device 30 executes the oil supply process on the condition that a predetermined period PP has elapsed since the previous execution of the oil supply process. Thereby, the fuel supply device 15 can suppress the execution opportunity of the oil supply process from becoming excessive.

[0048] (3) When at least one of the above conditions (A1), (A2), and (A3) is satisfied, even if the pressure of the gas fuel in the delivery pipe 22 is relatively low, the injection amounts of the gas fuel of the plurality of fuel injection valves 14 can be appropriately controlled. Therefore, the oil supply device 30 supplies oil into the delivery pipe 22 when at least one of the above conditions (A1), (A2), and (A3) is satisfied. Thereby, the fuel supply device 15 can supply oil into the delivery pipe 22 while appropriately operating the internal combustion engine 10.

[0049] (Modification example) The above embodiment can be implemented with the following modifications. The above embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0050] · If a predetermined period PP has elapsed since the oil supply process was last executed, the processing circuit 51 may execute the oil supply process even if none of the above conditions (A1), (A2), and (A3) are satisfied.

[0051] · If all of the above conditions (A1), (A2), and (A3) are satisfied, the processing circuit 51 may execute the oil supply process regardless of whether a predetermined period PP has elapsed since the oil supply process was last executed.

[0052] · Depending on how the internal combustion engine 10 is operated, the rate of decrease in the remaining amount of oil in the delivery pipe 22 can vary. Therefore, the predetermined period PP may be changed according to the operating state of the internal combustion engine 10. For example, the processing circuit 51 may determine that the predetermined period has elapsed when the number of injections of the gas fuel of the fuel injection valve 14 since the oil supply process was last executed reaches a predetermined number or more. Even in this case, the processing circuit 51 can change the length of the predetermined period according to the operating state of the internal combustion engine 10.

[0053] · The internal combustion engine to which the fuel supply device is applied may be an internal combustion engine that uses a gaseous fuel other than hydrogen. Examples of gaseous fuels other than hydrogen include compressed natural gas.

[0054] · The processing circuit 51 includes a CPU and a ROM, and is not limited to executing software processing. That is, the processing circuit 51 may have any of the following configurations (a), (b), and (c).

[0055] (a) The processing circuit 51 includes one or more processors that execute various processes according to a computer program. The processor includes a CPU and memories such as a RAM and a ROM. The memory stores program codes or instructions configured to cause the CPU to execute processing. The memory, that is, the computer-readable medium, includes any available medium accessible by a general-purpose or dedicated computer.

[0056] (b) The processing circuit 51 includes one or more dedicated hardware circuits that execute various processes. Examples of dedicated hardware circuits include application-specific integrated circuits, that is, ASICs or FPGAs. Note that ASIC is an abbreviation for "Application Specific Integrated Circuit", and FPGA is an abbreviation for "Field Programmable Gate Array".

[0057] (c) The processing circuit 51 includes one or more processors that execute some of the various processes according to a computer program, and one or more dedicated hardware circuits that execute the remaining processes of the various processes.

[0058] Note that, as used herein, the expression "at least one" means "one or more" of the desired options. As an example, the expression "at least one" as used herein means "only one option" or "both of the two options" if the number of options is two. As another example, the expression "at least one" as used herein means "only one option" or "any combination of two or more options" if the number of options is three or more.

Explanation of Signs

[0059] 10…Internal combustion engine, 11…Cylinder, 14…Fuel injection valve, 15…Fuel supply device, 21…Fuel tank, 22…Delivery pipe, 23…Supply passage, 23A…Downstream portion, 25…Pressure reducing valve, 26…Shut-off valve, 30…Oil supply device, 31…Oil pump, 32…Oil supply passage, 33…Oil injection valve, 50…Control device, 51…Processing circuit.

Claims

1. A fuel supply device provided in an internal combustion engine equipped with a fuel injection valve for injecting gas fuel, a fuel tank for storing the high-pressure gas fuel, a delivery pipe in which the gas fuel to be supplied to the fuel injection valve is stored, a supply passage through which the gas fuel supplied from the fuel tank to the delivery pipe flows, a shut-off valve provided in the supply passage and closed when the supply of the gas fuel to the delivery pipe is stopped, an oil supply device for supplying oil to a downstream portion which is a portion between a connection portion with the delivery pipe and a position of the shut-off valve in the supply passage, and a control device for controlling the shut-off valve and the oil supply device, and the control device executes an oil supply process of stopping the supply of the gas fuel to the delivery pipe by closing the shut-off valve during operation of the internal combustion engine, and supplying the oil to the downstream portion by the oil supply device under a situation where the pressure in the delivery pipe has dropped compared to before the shut-off valve is closed. Fuel supply device.

2. The control device executes the oil supply process on the condition that a predetermined period has elapsed since the time when the oil supply process was last executed. The fuel supply device according to Claim 1.

3. The control device changes the length of the predetermined period according to the operating state of the internal combustion engine. The fuel supply device according to Claim 2.

4. When the predetermined period has elapsed since the time when the control device last executed the oil supply process, the control device executes the oil supply process when at least one of the following conditions is satisfied: the internal combustion engine is idling, the operation of the internal combustion engine is before stopping, and the start of the decrease in the rotational speed of the internal combustion engine has not occurred. The fuel supply device according to Claim 2 or Claim 3.

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