Fuel tank system

Abstract

In the present invention, a vapor tube is opened using a valve, thereby releasing an evaporated fuel inside a tank to the atmosphere via the vapor tube, a canister, and a vent tube to create an internal pressure reduction state where the internal pressure of the tank is not more than a prescribed value, and then the vapor tube is closed using the valve before the start of fueling, such that the evaporated fuel inside the tank during fueling is released to the atmosphere via a fuel filler opening without the evaporated fuel passing through the canister.

Description

Fuel tank system

[0001] The present invention relates to a fuel tank system.

[0002] Conventionally, in the field of fuel tanks mounted on vehicles such as automobiles, technologies have been developed to prevent the release of fuel vapor gas evaporated in the fuel tank into the atmosphere. For example, Patent Document 1 discloses a fuel tank, a canister communicating with the fuel tank, and a sealing valve controlled to seal the fuel tank in a path communicating the fuel tank and the canister. During refueling, the sealing valve is opened so that fuel vapor gas flows out toward the canister, and the fuel vapor gas is adsorbed by the canister.

[0003] ORVR (Onboard Refueling Vapor Recovery) regulations that define preventing the release of evaporated fuel from the fuel tank into the atmosphere during refueling are known. In order to satisfy the ORVR regulations, it is necessary to adsorb the evaporated fuel during refueling as in the above-described conventional technology.

[0004] The implementation status of the ORVR regulations varies by country and region. Therefore, in regions where the ORVR regulations are implemented (e.g., North American regions), it is necessary to increase the size of the canister to adsorb the vapor gas with a volume corresponding to the refueling amount. However, in other regions where the ORVR regulations are not implemented (e.g., Japan), since it is not required to adsorb the evaporated fuel into the canister during refueling, a canister with an increased size may be over-specified and result in increased costs.

[0005] Japanese Patent Application Laid-Open No. 2015-123885

[0006] Therefore, an object of the present invention is to provide a fuel tank system that can reduce the capacity of the canister and reduce costs.

[0007] The present invention comprises the following configuration: (1) a fuel tank system comprising: a tank for storing fuel; a filler pipe connected to the tank for introducing the fuel; a fuel inlet formed in the filler pipe; a canister for adsorbing evaporated fuel generated in the tank; a vent tube connecting the canister to the atmosphere; a vapor tube connecting the tank to the canister; and a valve provided in the vapor tube for switching the communication state between the tank and the canister by opening and closing it; wherein by opening the vapor tube with the valve, evaporated fuel in the tank is released to the atmosphere via the vapor tube, the canister, and the vent tube, and the internal pressure of the tank is reduced to a predetermined value or less; and by closing the vapor tube with the valve before refueling begins, evaporated fuel in the tank during refueling is released to the atmosphere via the fuel inlet without going through the canister.

[0008] According to the present invention, it is possible to reduce the capacity of the canister and provide a fuel tank system that can reduce costs.

[0009] Figure 1 is a diagram of the fuel tank system according to the first embodiment. Figure 2 is a flowchart for explaining the control performed in the fuel tank system according to the first embodiment. Figure 3 is a diagram showing the state of the fuel tank system in step S3 of Figure 2. Figure 4 is a diagram showing the state of the fuel tank system in step S7 of Figure 2. Figure 5 is a diagram showing the state of the fuel tank system in step S8 of Figure 2. Figure 6 is a diagram showing the state of the fuel tank system in step S9 of Figure 2. Figure 7 is a diagram showing the state of the fuel tank system in step S9 of Figure 2. Figures 8(a) and (b) are enlarged views of the area around the filler port of the filler pipe, where Figure 8(a) shows the state with the filler cap attached to the filler port, and Figure 8(b) shows the state with the filler cap removed from the filler port. Figures 9(a) and (b) are enlarged views of the area around the filler port of the filler pipe according to a modified example, where Figure 9(a) shows the state before the refueling nozzle is inserted into the filler port, and Figure 9(b) shows the state after the refueling nozzle is inserted into the filler port. Figure 10 is a diagram illustrating the configuration of the fuel tank system according to the second embodiment. Figure 11 is a flowchart illustrating the control performed in the fuel tank system according to the second embodiment.

[0010] Embodiments of the present invention will now be described in detail with reference to the drawings. The embodiments shown below are merely illustrative, and there is no intention to exclude various modifications or applications of techniques not explicitly shown in the embodiments below. Each configuration of the embodiments can be modified in various ways without departing from their spirit. Furthermore, they can be selected or combined as needed.

[0011] Figure 1 is a diagram showing the configuration of a fuel tank system 1 (hereinafter also referred to as "System 1") according to the first embodiment. System 1 is a system that is mounted on a vehicle such as an automobile (not shown). System 1 comprises a tank 10 for storing fuel FL, a filler pipe 20 connected to the tank 10 for introducing fuel FL, a fuel inlet 30 formed in the filler pipe 20 which is a fuel inlet, a canister 40 for adsorbing evaporated fuel FV generated in the tank 10, a vent tube 50 connecting the canister 40 to the atmosphere, a vapor tube 60 connecting the tank 10 and the canister 40, and a sealing valve 70 (valve) provided in the vapor tube 60 which switches the communication state between the tank 10 and the canister 40 by opening and closing it.

[0012] The tank 10 is a housing for storing fuel FL such as gasoline. Inside the tank 10 are a fuel pump that supplies fuel FL to the engine's fuel injection valve via fuel piping, and a fuel gauge unit that detects the liquid level of fuel FL in the tank 10. Refueling is being performed as long as the liquid level of fuel FL detected by the fuel gauge unit is rising, and it can be determined that refueling is complete when the liquid level stops rising.

[0013] The canister 40 is a device that adsorbs evaporated fuel FV generated in the tank 10 onto an adsorbent. The casing of the canister 40 contains a well-known adsorbent such as activated carbon. The gas containing evaporated fuel FV in the tank 10 is released into the atmosphere via the canister 40 and the vent tube 50, and the internal pressure P of the tank 10 decreases. At this time, the canister 40 adsorbs the evaporated fuel FV, suppressing the release of a large amount of evaporated fuel FV into the outside air.

[0014] Furthermore, System 1 includes a purge tube 80 that connects the canister 40 to the engine's intake manifold. When the air taken in through the vent tube 50 by the negative pressure generated in the intake during engine operation passes through the canister 40, the evaporated fuel FV adsorbed in the canister 40 is detached (purged) from the activated carbon of the canister 40 and introduced into the intake manifold via the purge tube 80.

[0015] A solenoid valve 90 is positioned at the connection point between the canister 40, the vapor tube 60, and the purge tube 80. The solenoid valve 90 can switch the communication state between the canister 40, the vapor tube 60, and the purge tube 80.

[0016] The vapor tube 60 is a pipe that forms a flow path connecting the tank 10 and the canister 40. One end of the vapor tube 60 is connected to the part of the tank 10 where evaporated fuel FV accumulates, that is, the upper part of the tank 10. The other end of the vapor tube 60 is connected to the canister 40.

[0017] The sealing valve 70 is a solenoid valve interposed in the middle of the vapor tube 60, and by opening and closing it, it connects or blocks the flow path between the tank 10 and the canister 40, switching the state of connection between them. In other words, the sealing valve 70 seals the tank 10 by closing the vapor tube 60, and leaves the tank 10 unsealed by opening the vapor tube 60.

[0018] Furthermore, the vapor tube 60 may be provided with a bypass 61 that bypasses the sealing valve 70, and a safety valve 63 interposed in the bypass 61. The safety valve 63 is for reducing the internal pressure P in emergencies, such as when the internal pressure P of the tank 10 exceeds a predetermined value, and is, for example, a mechanical pressure valve that opens at a predetermined pressure. Therefore, under normal circumstances, the bypass 61 is closed by the safety valve 63.

[0019] The sealing valve 70 is a solenoid valve controlled by the control device 3. Normally, the sealing valve 70 is in a closed state, maintaining a sealed state of the tank 10 by keeping the vapor tube 60 closed. Furthermore, as will be described later, the sealing valve 70 opens before the lid 37 or filler cap 31 is opened, releasing the vapor tube 60 and switching the tank 10 to an unsealed state. This reduces the internal pressure P of the tank 10, suppressing fuel backflow from the fuel filler port 30 during refueling. The opening and closing of the sealing valve 70 is controlled by the control device 3.

[0020] The fuel filler port 30 is the fuel inlet to the tank 10 and is formed at the end of the filler pipe 20. The filler pipe 20 is a pipe for introducing fuel FL into the tank 10. One end of the filler pipe 20 is installed in the tank 10, and the other end of the filler pipe 20 is installed outside the tank 10, for example on the side of the vehicle body, so as to be open to the atmosphere, forming the fuel filler port 30. The fuel filler port 30 is equipped with a detachable filler cap 31, which is a plug member. After the filler cap 31 is manually removed, the fuel nozzle 39 (see Figure 6) is inserted. As will be described later with reference to Figure 9, in the capless version of the fuel filler port 30, the port is closed not by the filler cap 31, but by a flap valve 33 that opens when the fuel nozzle 39 is inserted.

[0021] System 1 includes a leveling pipe 21 that connects the tank 10 to the vicinity of the filler pipe 20 near the fuel inlet 30. As will be described later, evaporated fuel FV generated in the tank 10 can be released to the atmosphere through the leveling pipe 21 and the fuel inlet 30.

[0022] System 1 includes a housing section 35 for housing the fuel filler port 30 and a lid 37 for opening and closing the housing section 35. The housing section 35 is a groove recessed in the outer surface of the vehicle, and houses the fuel filler port 30, which is sealed by the filler cap 31. The lid 37 is a door that closes the housing section 35 and constitutes part of the outer surface of the vehicle body. When the user operates the operation unit 5, the lock on the lid 37 is released by an actuator controlled by the control device 3, allowing it to be opened. Alternatively, the lid 37 may be automatically opened by a spring or the like when the lock is released. Furthermore, when the lid 37 is closed after refueling is complete, the actuator may transmit a signal to the control device 3 indicating that the lid 37 has been closed.

[0023] The operating unit 5 for opening the lid 37 is operated manually prior to refueling the tank 10, and is, for example, a switch located in the driver's seat (not shown) of the vehicle. The operation of the operating unit 5 controls the actuator, which opens the lid 37.

[0024] The tank 10 is equipped with a pressure sensor 11 that measures (detects) the internal pressure P of the tank 10. As will be described later, after the pressure sensor 11 detects that the internal pressure P of the tank 10 is below a predetermined value P1, the lid 37 and filler cap 31 are opened and refueling is performed.

[0025] The control device 3 is composed of an input device, an output device, a storage device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), etc., and is connected to the communication line of the vehicle's network. The input device of the control device 3 is connected to an operation unit 5, a pressure sensor 11, a laser sensor 7 (see Figures 8(a) and (b)), a gap sensor 9 (see Figures 9(a) and (b)), etc. The output device of the control device 3 is connected to a sealing valve 70, an actuator that locks the lid 37, etc.

[0026] Figure 2 is a flowchart illustrating the control performed in the fuel tank system according to the first embodiment.

[0027] As shown in Figure 2, in step S1, the vehicle stops at a gas station or similar location and the engine is turned off (READY OFF).

[0028] In the following step S2, the user operates the control unit 5, and the lid 37 is unlocked and made open by an actuator controlled by the control device 3.

[0029] In step S3, the control device 3 opens the sealing valve 70. Figure 3 shows the state of the fuel tank system 1 in step S3 of Figure 2. As indicated by the arrows in Figure 3, by opening the vapor tube 60 with the sealing valve 70 (step S3), the evaporated fuel FV in the tank 10 is released to the atmosphere through the vapor tube 60, canister 40, and vent tube 50 (step S4). In step S5, the internal pressure P of the tank 10, measured by the pressure sensor 11, drops to atmospheric pressure, and the internal pressure P becomes less than a predetermined value P1 (P < P1), resulting in a reduced internal pressure state.

[0030] Next, in step S6, the user opens the lid 37. Then, in step S7, the user removes the filler cap 31 and opens the fuel inlet 30. Figure 4 shows the state of the fuel tank system 1 in step S7 of Figure 2. When the fuel inlet 30 is opened, the evaporated fuel FV in the tank 10 is released to the atmosphere through the filler pipe 20, the leveling pipe 21, and the fuel inlet 30, as indicated by the arrows in Figure 4.

[0031] In step S7, the opening of the fuel filler port 30, that is, the removal of the filler cap 31 from the fuel filler port, is detected by a sensor. The sensor is not particularly limited as long as it is capable of detecting the attachment / detachment state of the filler cap 31 to the fuel filler port 30, and examples include photoelectric sensors, fiber sensors, ultrasonic sensors, image sensors, etc.

[0032] Figures 8(a) and 8(b) are enlarged views of the area around the fuel inlet 30 of the filler pipe 20. Figure 8(a) shows the state in which the filler cap 31 is attached to the fuel inlet 30, and Figure 8(b) shows the state in which the filler cap 31 has been removed from the fuel inlet 30. In the examples shown in Figures 8(a) and 8(b), a laser sensor 7 is used as the sensor. As shown in Figure 8(a), the laser sensor 7 emits light OL from its light-emitting unit toward the filler cap 31, and if the light-receiving unit detects the reflected light RL from the filler cap 31, it detects that the filler cap 31 is attached to the fuel inlet 30. Conversely, as shown in Figure 8(b), the laser sensor 7 emits light OL from its light-emitting unit toward the filler cap 31, and if the light-receiving unit cannot detect the reflected light RL from the filler cap 31, it detects that the filler cap 31 has been removed from the fuel inlet 30. If it is detected that the filler cap 31 has been removed, it is determined that the fuel filler port 30 has been opened.

[0033] When the fuel filler port 30 is opened before refueling begins while the internal pressure is reduced (P < P1), in step S8, the vapor tube 60 is closed by the sealing valve 70. Figure 5 shows the state of the fuel tank system 1 in step S8 of Figure 2. As shown in Figure 5, the flow path between the tank 10 and the canister 40 is blocked by the sealing valve 70.

[0034] In the following step S9, the fuel nozzle 39 is inserted into the fuel filler port 30. Figure 6 shows the state of the fuel tank system 1 in step S9 of Figure 2. As shown in Figure 6, the sealing valve 70 that was closed in step S8 remains closed even when the fuel nozzle 39 is inserted in step S9, and similarly remains closed in the subsequent step S10.

[0035] Then, in step S10, fuel FL is introduced from the refueling nozzle 39. Figure 7 shows the state of the fuel tank system 1 in step S9 of Figure 2. As shown by the dashed arrows in Figure 7, fuel FL flows into the tank 10 via the filler pipe 20. At this time, since the vapor tube 60 is closed by the sealing valve 70 before refueling begins, the evaporated fuel FV in the tank 10 during refueling does not flow into the vapor tube 60 or the canister 40. As shown by the solid arrows in Figure 7, the evaporated fuel FV in the tank 10 during refueling is released to the atmosphere via the leveling pipe 21 and the refueling port 30. In this way, the flow shown in Figure 2 is completed.

[0036] After refueling is complete, remove the refueling nozzle 39 from the refueling port 30, close the refueling port 30 with the filler cap 31, and close the lid 37.

[0037] As described above, in the system 1, by opening the vapor tube 60 with the sealing valve 70, the evaporated fuel FV in the tank 10 is released to the atmosphere via the vapor tube 60, canister 40, and vent tube 50, and after the internal pressure P of the tank 10 is reduced to a predetermined value P1 or less, the vapor tube 60 is closed with the sealing valve 70 before refueling begins, so that the evaporated fuel FV in the tank 10 during refueling is released to the atmosphere via the refueling port 30 without going through the canister 40. Therefore, since it is not necessary to adsorb the evaporated fuel FV in the canister 40 during refueling, the capacity of the canister 40 can be reduced, and costs can be reduced. Such a configuration is suitable for vehicles sold in countries and regions where ORVR regulations are not implemented. In addition, since refueling is started after the internal pressure is reduced, the fuel FL does not flow back through the refueling port 30. If refueling is started while the internal pressure P of the tank 10 is high, there is a possibility that fuel FL will flow back through the fuel filler port 30, which is undesirable. Therefore, the predetermined value P1 that defines the internal pressure reduction state (P < P1) is set to a value such that fuel FL does not flow back through the fuel filler port 30.

[0038] Furthermore, the fuel inlet 30 can be opened and closed by a filler cap 31, which is a stopper member. A sealing valve 70 is provided in the vapor tube 60, and when the fuel inlet 30 is opened before refueling begins, after the internal pressure has been reduced, the sealing valve 70 closes the vapor tube. In this way, when the fuel inlet 30, which is sealed by the filler cap 31, is opened, that is, before refueling, the vapor tube 60 connecting the tank 10 and the canister 40 is closed, so that evaporated fuel FV does not reach the canister 40 during refueling.

[0039] Furthermore, System 1 is equipped with a laser sensor 7 capable of detecting the attachment / detachment status of the cap to the fuel filler port 30. The laser sensor 7 detects when the filler cap 31 has been removed from the fuel filler port 30, thereby detecting that the fuel filler port 30 has been opened. Therefore, since the opening of the fuel filler port 30 can be detected by the laser sensor 7, the vapor tube 60 can be closed by the sealing valve 70 at a more precise timing.

[0040] Furthermore, System 1 includes a lid 37 that opens and closes a housing section 35 that houses the fuel filler port 30. After the internal pressure is reduced, the lid 37 is opened. Then, after the lid 37 is opened, when the fuel filler port 30 is opened before refueling begins, the vapor tube 60 is closed by the sealing valve 70. If the vapor tube 60 were closed after the lid 37 is opened but before the fuel filler port 30 is opened, the internal pressure P of the tank 10 would rise above a predetermined value P1, potentially causing fuel FL to blow back out of the fuel filler port 30 during refueling. To prevent this, when the lid 37 is opened, the sealing valve 70 keeps the vapor tube open. Then, when the fuel filler port 30 is opened, that is, immediately before refueling, the sealing valve 70 closes the vapor tube 60. Therefore, fuel FL is prevented from blowing back out of the fuel filler port 30 during refueling.

[0041] Figures 9(a) and 9(b) are enlarged views of the area around the fuel inlet 30 of the filler pipe 20 according to the modified example. Figure 9(a) shows the state before the fuel nozzle 39 is inserted into the fuel inlet 30, and Figure 9(b) shows the state after the fuel nozzle 39 has been inserted into the fuel inlet 30. In this modified example, the fuel inlet 30 is a capless fuel inlet without a filler cap.

[0042] The fuel filler port 30 is equipped with a flap valve 33 positioned to close the fuel filler port 30 and which opens when a fuel nozzle 39 is inserted. The fuel filler port 30 is also equipped with a coil spring 34 that biases the flap valve 33 in the direction of closing. Therefore, as shown in Figure 9(a), when the fuel nozzle 39 is not inserted, the fuel filler port 30 is closed by the flap valve 33. Conversely, as shown in Figure 9(b), when the fuel nozzle 39 is inserted, the flap valve 33 opens and the fuel filler port 30 opens. The opening of the fuel filler port 30, i.e., the opening of the flap valve 33, is detected by a sensor. The sensor is not particularly limited as long as it is capable of detecting the open / closed state of the flap valve 33.

[0043] In the examples shown in FIGS. 9(a) and 9(b), a gap sensor 9 is applied as the sensor. The type of the gap sensor 9 is not particularly limited, and an optical sensor, an ultrasonic sensor, an electromagnetic sensor, a capacitance sensor, etc. may be appropriately selected and adopted. As shown in FIG. 9(b), when the fuel supply nozzle 39 is inserted, the flap valve 33 opens, and the distance L between the gap sensor 9 and the flap valve 33 decreases. Thereby, the gap sensor 9 detects that the flap valve 33 has opened. When it is detected that the flap valve 33 has opened, it is determined that the fuel filler opening 30 has opened.

[0044] Even when the capless specification is adopted in this way, since the fuel filler opening 30 can be detected by the gap sensor 9, the vapor tube 60 can be closed by the seal valve 70 at a more accurate timing.

[0045] FIG. 10 is a configuration diagram of the fuel tank system 1 according to the second embodiment. As shown in FIG. 10, the fuel tank system 1 according to the second embodiment is different from the first embodiment in that it includes a first path 65, a second path 67, and an on-off valve 71, which will be described later. Since the other configurations are the same as those of the first embodiment, the description will be omitted or simplified by attaching the same reference numerals as those of the first embodiment to the drawings.

[0046] The vapor tube 60 includes a first path 65 connecting the seal valve 70 and the filler pipe 20, and a second path 67 connecting the filler pipe 20 and the canister 40. An on-off valve 71 (valve) for opening and closing the path between the first path 65 and the second path 67 is provided in the filler pipe 20.

[0047] The on-off valve 71 has a mechanism that closes the path between the first path 65 and the second path 67 when the fueling nozzle 39 is inserted into the filler pipe 20, and opens the path between the first path 65 and the second path 67 when the fueling nozzle 39 is removed from the filler pipe 20. Examples of such a mechanism include those having a spring member that biases the path between the first path 65 and the second path 67 in the opening direction. When the fueling nozzle 39 is not inserted into the filler pipe 20, the vapor tube 60 is in a communicating state. On the other hand, when the fueling nozzle 39 is inserted into the filler pipe 20, the pressing force of the fueling nozzle 39 exceeds the biasing force of the spring member, closing the path between the first path 65 and the second path 67, and the vapor tube 60 is in a blocked state.

[0048] Figure 11 is a flowchart for explaining the control implemented in the fuel tank system according to the second embodiment. Steps S1 to S7 are the same as the flowchart in the first embodiment shown in FIG. 2, and thus the description thereof is omitted.

[0049] After removing the filler cap 31 and opening the fuel filler port 30 in step S7, in step S9, the fueling nozzle 39 is inserted into the fuel filler port 30. In step S11, as the fueling nozzle 39 is inserted, the on-off valve 71 closes the path between the first path 65 and the second path 67, and the vapor tube 60 is in a blocked state. Thereafter, in step S10, fueling is performed.

[0050] Thus, in the present embodiment, since the vapor tube 60 is closed by the on-off valve 71 before the start of fueling, the evaporated fuel FL in the tank 10 during fueling can be released to the atmosphere through the fuel filler port 30 without passing through the canister. Also, since the communication state of the vapor tube 60 can be switched by simply inserting and removing the fueling nozzle 39 without controlling the opening and closing of the seal valve 70 as in the first embodiment, the control is simple.

[0051] As described above, the following matters are disclosed in this specification.

[0052] (1) A fuel tank system comprising: a tank for storing fuel; a filler pipe connected to the tank for introducing the fuel; a fuel inlet formed in the filler pipe; a canister for adsorbing evaporated fuel generated in the tank; a vent tube connecting the canister to the atmosphere; a vapor tube connecting the tank to the canister; and a valve provided in the vapor tube for switching the state of communication between the tank and the canister by opening and closing it, wherein by opening the vapor tube with the valve, evaporated fuel in the tank is released to the atmosphere via the vapor tube, the canister, and the vent tube, and the internal pressure of the tank is reduced to a predetermined value or less, and then by closing the vapor tube with the valve before refueling begins, evaporated fuel in the tank during refueling is released to the atmosphere via the fuel inlet without going through the canister.

[0053] According to (1), since there is no need to adsorb evaporated fuel into the canister during refueling, the canister capacity can be reduced, thus lowering costs. Such a configuration is suitable for vehicles sold in countries and regions where ORVR regulations are not implemented. In addition, since refueling is started after the internal pressure has been reduced, fuel does not flow back through the fuel filler neck.

[0054] (2) The fuel tank system according to (1), wherein the fuel filler port is openable and closable by a stopper member, the valve includes a sealing valve provided in the vapor tube, and when the fuel filler port is opened before refueling begins after the internal pressure has been reduced, the sealing valve closes the vapor tube.

[0055] According to (2), when the fuel filler opening, which is blocked by the filler cap, is opened, that is, before refueling, the vapor tube connecting the tank and the canister is closed, so that evaporated fuel is reliably prevented from reaching the canister during refueling.

[0056] (3) The fuel tank system according to (2), wherein the stopper member is a filler cap detachably provided on the fuel filler port, and is equipped with a sensor capable of detecting the attachment or detachment state of the filler cap to the fuel filler port, and the system detects that the fuel filler port has been opened by detecting that the filler cap has been removed from the fuel filler port using the sensor.

[0057] According to (3), the sensor can detect when the fuel filler port is opened, allowing the vapor tube to be closed by the sealing valve at a more precise timing.

[0058] (4) The fuel tank system according to (2), wherein the stopper member is a flap valve that opens when a fuel nozzle is inserted, and is equipped with a sensor capable of detecting the open / closed state of the flap valve, and the system detects that the fuel port has been opened by detecting that the flap valve has been opened by the sensor.

[0059] According to (4), even when a capless design is adopted, the sensor can detect when the fuel filler port is opened, so the vapor tube can be closed by the sealing valve at a more precise timing.

[0060] (5) The fuel tank system according to (2), comprising a lid for opening and closing a housing that houses the fuel filler port, wherein the lid is opened after the internal pressure is reduced, and after the lid is opened, the vapor tube is closed by the sealing valve when the fuel filler port is opened before refueling begins.

[0061] According to (5), fuel is prevented from being blown back out of the fuel filler neck during refueling.

[0062] (6) The fuel tank system according to (1), wherein the valve includes a sealing valve provided in the vapor tube, the vapor tube includes a first path connecting the sealing valve to the filler pipe, and a second path connecting the filler pipe to the canister, the valve further includes an on-off valve provided in the filler pipe for opening and closing the path between the first path and the second path, the on-off valve has a mechanism for closing the path between the first path and the second path when a fuel nozzle is inserted into the filler pipe, and opening the path between the first path and the second path when the fuel nozzle is removed from the filler pipe.

[0063] According to (6), the control is simple because the on / off valve can be opened and closed and the communication state of the vapor tube 60 can be switched simply by inserting and removing the fuel nozzle, without having to control the opening and closing of the sealing valve.

[0064] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0065] This application is based on a Japanese patent application (Patent Application No. 2024-198468) filed on November 13, 2024, the contents of which are incorporated by reference within this application.

[0066] 1 Fuel tank system 3 Control device 5 Operating unit 7 Laser sensor (sensor) 9 Gap sensor (sensor) 10 Tank 11 Pressure sensor 20 Filler pipe 21 Leveling pipe 30 Fuel inlet 31 Filler cap (plug member) 33 Flap valve (plug member) 34 Coil spring 35 Storage section 37 Lid 39 Fuel nozzle 40 Canister 50 Vent tube 60 Vapor tube 61 Bypass route 63 Safety valve 65 First route 67 Second route 70 Sealing valve (valve) 71 On / off valve (valve) 80 Purge tube 90 Solenoid valve FL Fuel FV Evaporated fuel OL Emitted light P Tank internal pressure P1 Predetermined value RL Reflected light

Claims

1. A fuel tank system comprising: a tank for storing fuel; a filler pipe connected to the tank for introducing the fuel; a fuel inlet formed in the filler pipe; a canister for adsorbing evaporated fuel generated in the tank; a vent tube connecting the canister to the atmosphere; a vapor tube connecting the tank to the canister; and a valve provided in the vapor tube for switching the communication state between the tank and the canister by opening and closing it; wherein by opening the vapor tube with the valve, evaporated fuel in the tank is released to the atmosphere via the vapor tube, the canister, and the vent tube, and the internal pressure of the tank is reduced to a predetermined value or less; and by closing the vapor tube with the valve before refueling begins, evaporated fuel in the tank during refueling is released to the atmosphere via the fuel inlet without going through the canister.

2. The fuel tank system according to claim 1, wherein the fuel filler port is openable and closable by a stopper member, the valve includes a sealing valve provided in the vapor tube, and when the fuel filler port is opened before refueling begins after the internal pressure has been reduced, the sealing valve closes the vapor tube.

3. The fuel tank system according to claim 2, wherein the stopper member is a filler cap detachably provided on the fuel filler port, and is equipped with a sensor capable of detecting the attachment or detachment state of the filler cap to or from the fuel filler port, and the system detects that the fuel filler port has been opened by detecting that the filler cap has been removed from the fuel filler port using the sensor.

4. The fuel tank system according to claim 2, wherein the stopper member is a flap valve that opens when a fuel nozzle is inserted, and is equipped with a sensor capable of detecting the open / closed state of the flap valve, and the system detects that the fuel port has been opened by detecting that the flap valve has been opened by the sensor.

5. A fuel tank system according to claim 2, comprising a lid for opening and closing a housing that houses the fuel filler port, wherein the lid is opened after the internal pressure is reduced, and after the lid is opened, the vapor tube is closed by the sealing valve when the fuel filler port is opened before refueling begins.

6. The fuel tank system according to claim 1, wherein the valve includes a sealing valve provided in the vapor tube, the vapor tube includes a first path connecting the sealing valve to the filler pipe, and a second path connecting the filler pipe to the canister, the valve further includes an on-off valve provided in the filler pipe for opening and closing the path between the first path and the second path, the on-off valve having a mechanism for closing the path between the first path and the second path when a fuel nozzle is inserted into the filler pipe, and opening the path between the first path and the second path when the fuel nozzle is removed from the filler pipe.

Images