JP2021195908A - Vehicle fuel tank system and abnormality diagnostic method - Google Patents

Abstract

To provide a vehicle fuel tank system and an abnormality diagnostic method capable of accurately and reliably diagnosing opening-closing abnormality of an opening-closing control valve in any vehicle.SOLUTION: A vehicle fuel tank system 1 comprises: a fuel tank 10: a filler pipe 20; a canister 50; an evaporated gas supply passage 30 to supply evaporated gas inside the fuel tank 10 to the canister 50; a sealing valve 40 installed in the middle of the evaporated gas supply passage 30; a breather pipe 26 capable of discharging the evaporated gas inside the fuel tank 10 into the filler pipe 20 when fuel is supplied to the fuel tank 10; a pressure sensor 11 measuring pressure inside the fuel tank 10; and engine control unit 60 which controls opening and closing of the sealing valve 40. The engine control unit 60 diagnoses opening-closing abnormality of the sealing valve 40 on the basis of a trend of pressure inside the fuel tank 10 measured through the pressure sensor 11 when the fuel is supplied to the fuel tank 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle fuel tank system and a method for diagnosing an abnormality thereof, and in particular, a vehicle fuel tank system provided with an on-off control valve provided in a pipeline of a fuel evaporative gas supply path connecting a fuel tank and a canister. It relates to the abnormality diagnosis method.

Conventionally, in a fuel tank system of a vehicle, in order to prevent the fuel evaporative gas generated in the fuel tank (hereinafter referred to as "epabo gas") from leaking to the atmosphere.
(A) First, the evaporative gas in the fuel tank is adsorbed on the activated carbon or the like in the canister (fuel evaporative emission suppression).
(B) Next, when the engine is driven, the evaporative gas adsorbed on the canister is purged into the intake system of the engine and burned in the engine combustion chamber.
By following the procedure such as, the eva pogas is processed.

By the way, in recent years, in addition to an engine (internal engine), a vehicle equipped with a motor (motor) (for example, a hybrid vehicle (HV) or a plug-in hybrid vehicle (PHEV)) has become widespread as a drive source for the vehicle. ..
In such a vehicle, it is possible to stop the drive of the engine and run only by driving the motor, so compared to a vehicle equipped with only the engine, the evaporator gas adsorbed on the canister is purged to the intake system. It tends to decrease in frequency. In such a case, problems such as leakage of epabo gas to the atmosphere due to the breakage of the canister or the like are likely to occur.

Therefore, conventionally, as a method for solving such a problem, an on-off control valve for limiting the supply (discharge) of evaporative gas to the canister is provided in the pipeline of the fuel evaporative gas supply path connecting the fuel tank and the canister. The technique provided inside is adopted (see Patent Document 1).

According to the technique of Patent Document 1, the onboard refueling control valve is opened and the epabo gas is supplied (discharged) to the canister only at a predetermined time such as when the engine is started or when refueling. , Epabo gas can be treated well without leaking to the atmosphere.

Japanese Unexamined Patent Publication No. 2001-165003

However, in the technique of Patent Document 1, if an opening / closing abnormality (opening failure and closing failure) occurs in the opening / closing control valve, it becomes impossible to process the epova gas. It can be said that there is room for.

Generally, as a method for solving such a problem, it is conceivable to diagnose an opening / closing abnormality of the opening / closing control valve based on the pressure difference in the fuel tank before and after the negative pressure of the fuel tank. However, in such a method, it is necessary to provide a negative pressure pump for making the fuel tank negative pressure. Therefore, for example, in a vehicle that is not specified to provide such a pump, the open / close control valve There is a problem that it is not possible to diagnose opening / closing abnormalities.

As another method, it is conceivable to diagnose the opening / closing abnormality of the opening / closing control valve based on the pressure difference between the fuel tank side and the canister side of the opening / closing control valve when the outside air temperature or the like changes when the engine is stopped. .. However, in such a method, especially when the vapor pressure of the fuel is low, a pressure difference is unlikely to occur, so that there is a risk of erroneous determination.

Further, as another method, it is conceivable to diagnose the opening / closing abnormality of the open / close control valve based on the pressure difference before and after the depressurization of the fuel tank. However, such a method has a problem that, for example, when the pressure in the fuel tank before depressurization is low, it is not possible to diagnose an open / close abnormality of the open / close control valve.

The present invention has been made to solve such a problem, and is capable of accurately and surely diagnosing an opening / closing abnormality of an opening / closing control valve in any vehicle, and a vehicle fuel tank system and abnormality determination. To provide a method.

According to the vehicle fuel tank system according to the present invention, the above problem is to adsorb a fuel tank for storing fuel, a fuel supply path for supplying fuel to the fuel tank, and fuel evaporative gas generated in the fuel tank. The canister, the fuel tank, and the canister are connected to each other, and the fuel evaporative gas in the fuel tank is supplied to the canister. An on-off control valve that can move between an open position that allows supply of fuel evaporative gas to the canister and a closed position that shuts off the fuel evaporative gas can be connected to the fuel tank and the fuel supply path to fuel the fuel tank. A discharge path capable of discharging the fuel evaporative gas in the fuel tank to the fuel supply path at the time of supply, a pressure measuring device capable of measuring the pressure in the fuel tank, and a control device for controlling the opening / closing of the opening / closing control valve. The control device of the on-off control valve is based on the transition of the pressure in the fuel tank measured by the pressure measuring device when the fuel is supplied to the fuel tank through the fuel supply path. It is solved by diagnosing opening / closing abnormality.

Further, the above-mentioned problem is an abnormality diagnosis method for diagnosing an abnormality in a fuel tank system of a vehicle according to the abnormality diagnosis method according to the present invention, wherein the fuel tank system includes a fuel tank for storing fuel and the fuel. The fuel supply path for supplying fuel to the tank, the canister that adsorbs the fuel evaporative gas generated in the fuel tank, the fuel tank and the canister are connected, and the fuel evaporative gas in the fuel tank is transferred to the canister. Opening and closing that is provided in the pipeline of the fuel evaporative gas supply path to be supplied and is movable between an open position that allows supply of the fuel evaporative gas to the canister and a closed position that cuts off the supply of the fuel evaporative gas to the canister. A discharge path that connects the control valve, the fuel tank, and the fuel supply path, and can discharge the fuel evaporative gas in the fuel tank to the fuel supply path when fuel is supplied to the fuel tank, and the fuel tank. A pressure measuring device capable of measuring the pressure inside the fuel tank is provided, and the abnormality diagnosis method is performed in the fuel tank measured by the pressure measuring device when fuel is supplied to the fuel tank via the fuel supply path. It is also solved by including a diagnostic step of diagnosing an opening / closing abnormality of the opening / closing control valve based on the transition of pressure.

The present invention having the above configuration is configured to diagnose an open / close abnormality of the open / close control valve based on the transition of the pressure in the fuel tank at the time of refueling.

That is, in the present invention, when the transition of the pressure in the fuel tank measured during refueling shows the same behavior as the predetermined transition of the pressure (the transition of the pressure when the on-off control valve is normal), " If it is diagnosed as "normal" but behaves differently from this, it can be diagnosed as "abnormal".

In this respect, since the present invention is configured to diagnose an opening / closing abnormality of the on-off control valve by using the pressure in the fuel tank that fluctuates during refueling, the vehicle is not equipped with a device such as a negative pressure pump. Even so, it can be said that this can be reliably performed without being affected by the properties of the fuel and the like.

Therefore, according to the present invention, it is possible to accurately and surely diagnose the opening / closing abnormality of the opening / closing control valve in any vehicle.

In the invention relating to the fuel tank system of the vehicle, the control device controls the opening / closing of the opening / closing control valve when the fuel is supplied to the fuel tank, and also controls the opening / closing of the fuel tank when the opening / closing control is performed. It is preferable to diagnose the opening / closing abnormality of the opening / closing control valve based on the transition of the pressure inside.

In this case, the control device diagnoses the opening / closing abnormality of the opening / closing control valve based on the transition of the pressure in the fuel tank when the opening / closing control for moving the opening / closing control valve from the closed position to the open position is performed. , And more suitable.

Further, in the control device, the on-off control valve is moved from the open position to the closed position based on the transition of the pressure in the fuel tank when the on-off control valve is moved from the open position to the closed position. It is more preferable to make a diagnosis as to whether or not it is present.

As described above, according to the vehicle fuel tank system and the abnormality diagnosis method for the vehicle according to the present invention, the diagnosis of the opening / closing abnormality of the opening / closing control valve can be accurately and reliably performed in any vehicle even though the configuration is relatively simple. Can be done in.

It is a schematic diagram for demonstrating the outline of the fuel tank system of the vehicle which concerns on this embodiment. It is a flow diagram for demonstrating the content of the abnormality diagnosis control processing which shows an example of the abnormality diagnosis method which concerns on this Embodiment. It is a graph which shows the transition of the pressure in a fuel tank at the time of abnormality diagnosis. It is a graph which shows the transition of the pressure in a fuel tank when the abnormality diagnosis is stopped in the middle. It is a graph which shows the transition of the pressure in other fuel tanks when the abnormality diagnosis is stopped in the middle.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram for explaining the outline of the fuel tank system of the vehicle according to the present embodiment, and FIG. 2 is a flow for explaining the contents of the abnormality diagnosis control process showing an example of the abnormality diagnosis method according to the present embodiment. FIG. 3 is a graph showing the transition of the pressure in the fuel tank at the time of abnormality diagnosis, FIG. 4 is a graph showing the transition of the pressure in the fuel tank when the abnormality diagnosis is stopped in the middle, and FIG. 5 is the graph showing the transition of the pressure in the fuel tank in the middle of the abnormality diagnosis. It is a graph which shows the transition of the pressure in other fuel tanks when it stopped at.

(Configuration of fuel tank system 1)
As shown in FIG. 1, the fuel tank system 1 according to the present embodiment is, for example, a vehicle (hybrid vehicle (HV) or a plug-in hybrid vehicle) traveling by the driving force of an engine (not shown) and a motor (not shown). PHEV))) or a vehicle that runs on the driving force of only the engine, and has a fuel tank 10, a filler pipe 20, an EVAPO gas supply path 30, a closed valve 40, a canister 50, and an engine control unit 60. I have. The fuel tank system 1, the vehicle, the fuel tank 10, the filler pipe 20, the evaporator gas supply path 30, the closed valve 40, the canister 50, and the engine control unit 60 are the scope of patent claims, respectively. The "fuel tank system", "vehicle", "fuel tank", "fuel supply path", "fuel evaporative gas supply path", "open / close control valve", "canister", and "canister" described in It corresponds to "control device".

(Fuel tank 10)
The fuel tank 10 is a tank for storing fuel (for example, gasoline) of an engine (not shown), and in the present embodiment, the side surface portion and the upper surface portion have a filler pipe 20 and a breather pipe 26 described later, respectively. , Is connected through the EVAPO gas supply path 30.
Further, the fuel tank 10 according to the present embodiment is provided with a pressure sensor 11 for measuring the pressure in the fuel tank 10 at an appropriate position thereof. The pressure sensor 11 corresponds to the "pressure measuring device" described in the claims.

(Filler pipe 20)
The filler pipe 20 is a pipeline for supplying fuel to the fuel tank 10 (hereinafter, also referred to as “fueling”), and a fuel injection port 20A (filler neck) for injecting fuel is formed at the upper end thereof. ing. A known filler cap 21 capable of hermetically sealing the fuel inlet 20A is attached to the fuel inlet 20A.
On the other hand, the lower end portion of the filler pipe 20 is arranged so as to open at a position closer to the bottom surface portion in the fuel tank 10.

Here, an operation procedure for supplying (refueling) fuel to the fuel tank 10 will be described.
Similar to the known vehicle, the vehicle according to the present embodiment is provided with a fuel filler flap (fuel filler lid, not shown) at a position covering the filler cap 21 of the vehicle body body (outer plate, not shown). The filler cap 21 can be removed from the fuel inlet 20A by opening the fuel inlet 20A.

In the present embodiment, the fuel filler flap is locked to the vehicle body by a lock mechanism (not shown) that operates based on a command from the engine control unit 60.
Further, such a lock is configured to be released by the control of the engine control unit 60 on condition that the refueling request switch 62 is operated by an occupant or the like. The refueling request switch 62 can be provided at a position where the occupant or the like can operate, for example, near the door handle on the outside in the vehicle direction.

As will be described in detail later, in the present embodiment, the closed valve 40 is normally closed, and the closed state of the fuel tank 10 is maintained.
Then, the internal pressure of the fuel tank 10 may become higher than the atmospheric pressure due to the influence of the change in the outside air temperature while the vehicle is stopped. In such a state, when the filler cap 21 is opened, There arises a problem that the evaporator gas generated in the fuel tank 10 is discharged into the atmosphere from the fuel inlet 20A of the filler cap 21.

Therefore, in the present embodiment, in order to solve such a problem, when the refueling request switch 62 is operated by an occupant or the like, the closed valve 40 is opened and the pressure in the fuel tank 10 becomes a predetermined pressure (for example). The lock mechanism is not allowed to be unlocked, that is, the fuel filler flap is not allowed to open until the pressure drops to below atmospheric pressure.

Summarizing these, in the present embodiment, the supply of fuel to the fuel tank 10 is
(A) An occupant or the like operates the refueling request switch 62 to output a request signal to the engine control unit 60.
(B) The closed valve 40 is opened under the control of the engine control unit 60 to reduce the pressure in the fuel tank 10 to a predetermined pressure.
(C) After the lock mechanism is unlocked by the control of the engine control unit 60, the occupant or the like operates a flap opening / closing lever (not shown) or the like connected to the lock mechanism to open the fuel filler flap.
(D) Remove the filler cap 21 and inject fuel from the fuel inlet 20A.
It is possible to do it by following the procedure.

A breather pipe 26 is branched and connected to the filler pipe 20 at a position adjacent to the fuel inlet 20A. The breather pipe 26 corresponds to the "discharge channel" described in the claims.

Here, the breather pipe 26 will be described because the breather pipe 26 connects the fuel tank 10 and the filler pipe 20 and discharges the evaporator gas (and air) generated in the fuel tank 10 to the filler pipe 20 at the time of refueling. It is a pipeline of. In the present embodiment, the lower end of the breather pipe 26 is arranged at a height position where the fuel is blocked by the fuel when the fuel is stored in the fuel tank 10 in a full tank state.

In this respect, it can be said that the breather pipe 26 works so as to discharge the epabo gas in the fuel tank 10 at the time of refueling so that the fuel can be smoothly supplied (injected) into the fuel tank 10. The above-mentioned evaporative gas corresponds to the "fuel evaporative gas" described in the claims.

(Evapogas supply path 30)
The EVAPO gas supply path 30 is a pipeline that connects the fuel tank 10 and the canister 50 and guides the EVAPO gas generated in the fuel tank 10 to the canister 50.

One end of the EVAPO gas supply path 30 according to the present embodiment is connected through the upper part of the fuel tank 10, and a full tank regulation valve 31 is attached to the tip thereof. Further, in the fuel tank 10, a branch pipeline 32 is branched and connected to the EVAPO gas supply passage 30, and a rollover valve 33 is attached to the tip thereof.

The full tank control valve 31 closes when the amount of fuel in the fuel tank 10 is full to prevent fuel from flowing into the EVAPO gas supply path 30, while opening the valve at other times during normal times. , Allows the inflow of Evapogas into the Evapogas supply channel 30. Further, the rollover valve 33 closes when the vehicle tilts or rolls over to prevent fuel from flowing into the branch pipeline 32, while opening the valve during other normal times to prevent the branch pipeline 32. It allows the inflow of Evapogas to 32.

(Sealed valve 40)
The closed valve 40 is provided in the pipeline of the EVAPO gas supply path 30 between the fuel tank 10 and the canister 50, and has an "open position" that allows supply of epabo gas to the canister 50 and a "closed position" that shuts off the output. It is a valve that can move between. The "closed position" and the "open position" correspond to the "closed position" and the "open position" described in the claims, respectively.
For such a closed valve 40, for example, it is possible to use a normally closed type solenoid valve that is closed in a non-energized state and is opened by supplying a drive signal from the engine control unit 60.

In the present embodiment, the closed valve 40 is opened when it is necessary to supply the evaporative gas from the fuel tank 10 to the canister 50 for processing (for example, when the engine is started), in addition to the above-mentioned refueling. At other times, the valve is closed to maintain the sealed state of the fuel tank 10.

(Canister 50)
The canister 50 has an adsorbent (for example, activated carbon, not shown) that adsorbs the evaporative gas inside the canister 50, adsorbs the evaporative gas supplied through the evaporative gas supply path 30 to the adsorbent, and adsorbs the evaporative gas to the adsorbent, and also via the purge passage 51. This is a device for purging (releasing) the activated carbon adsorbed on the adsorbent into the intake system of the engine (not shown). Evapogas purged into the intake system of the engine is burned in the combustion chamber of the engine.

(Engine control unit 60)
The engine control unit 60 (ECU: Engine Control Unit) is a control device for comprehensively controlling the vehicle, and is a central processing unit (CPU: Central Processing Unit) and a storage device (for example, ROM; Read Only Memory). , Input / output device, timer, etc. are included.

Although the details will be described later, the engine control unit 60 is based on the diagnostic reference information stored in the storage device (in the present embodiment, information indicating the transition of the pressure in the fuel tank 10 as shown in FIGS. 3 to 5). Then, a control process (control process related to the abnormality diagnosis method) for determining whether or not the closed valve 40 is out of order is performed. The above-mentioned abnormality diagnosis method corresponds to the "abnormality diagnosis method" described in the claims.

The engine control unit 60 is electrically connected to devices such as a pressure sensor 11, a closed valve 40, a warning lamp 61, a refueling request switch 62, and a lock mechanism.
The warning lamp 61 is provided, for example, on the instrument panel of the driver's seat, and as a result of performing control processing related to the abnormality diagnosis method described later, the sealing valve 40 fails (a failure that does not move from the “open position” to the “closed position”). (Hereinafter referred to as "open failure"), or when it is determined that there is a failure that does not move from the "closed position" to the "open position" (hereinafter referred to as "closed failure")), the occupant lights up. It is a device for warning (notifying the fact) to.
As will be described in detail later, in the present embodiment, since it is possible to determine even when the closed valve 40 has only "open failure", the warning lamp 61 for notifying "open failure" and "closed failure" is used. In addition, it is also possible to separately provide a warning lamp for open failure to notify "open failure". Further, such notification is not limited to lighting by the warning lamp 61 (and the warning lamp for open failure), and for example, an image showing the fact may be displayed on a display means such as a liquid crystal display unit. It is also possible to emit sound from a speaker or the like.

(Structure of abnormality diagnosis method)
Next, the control process related to the abnormality diagnosis method (hereinafter referred to as “abnormality diagnosis control process”) executed in the engine control unit 60 will be described with reference to FIGS. 1 to 5.
In this embodiment, it should be noted that
(A) Backup power supply (not shown) even when power is being supplied to the engine control unit 60, for example, the so-called ignition key (not shown) is ON or the ignition key is OFF. Power is being supplied from
(B) Refueling is completed when the fuel is full (with the breather pipe 26 blocked by the fuel).
Will be explained on the premise of.

(Step S100)
As shown in FIGS. 1 and 2, the "abnormality diagnosis control process" begins with performing a process (process of step S100) of determining whether or not the refueling request switch 62 has been operated by an occupant or the like.
Specifically, the engine control unit 60 performs a process of determining whether or not the refueling request switch 62 is turned on in step S100.
As shown in FIGS. 1 and 2, when the engine control unit 60 determines that the refueling request switch 62 is turned on, the process shifts to step S200, and when it is determined that the vehicle is not turned on, the present "abnormality diagnosis" is performed. "Control processing" is terminated.

(Step S200)
In step S200, the engine control unit 60 performs a process of moving the closed valve 40 from the “closed position” to the “open position” (process of opening the valve). As a result, the epabo gas in the fuel tank 10 is supplied (discharged) to the canister 50 via the epabo gas supply path 30, so that the pressure in the fuel tank 10 gradually decreases.
The engine control unit 60 performs a process of opening the closed valve 40, and then shifts the process to step S300.

(Step S300)
In step S300, the engine control unit 60 determines whether or not the pressure in the fuel tank 10 measured by the pressure sensor 11 is equal to or less than a predetermined pressure value (for example, atmospheric pressure or a pressure close thereto). Performs the judgment process.
When the engine control unit 60 determines that the pressure in the fuel tank 10 is equal to or less than the predetermined pressure value, the process is transferred to step S400, and when it is determined that the pressure is not equal to or less than the predetermined pressure value, this process is performed until the pressure becomes equal to or less than the predetermined pressure value. Is repeated.

(Step S400)
In step S400, the engine control unit 60 performs (a) a process of moving (closing) the closed valve 40 from the “open position” to the “closed position”, and (b) permits the opening of the fuel filler port flap. Therefore, the process of unlocking the lock mechanism is performed. As a result, (a) the discharge of epabo gas from the fuel tank 10 to the canister 50 is stopped, and (b) the occupant or the like can open the fuel filler flap by operating the flap opening / closing lever or the like (refueling is possible). State).
The engine control unit 60 closes the closed valve 40 and releases the lock mechanism, and then moves to step S500.

(Step S500)
In step S500, the engine control unit 60 performs a process of determining whether or not refueling has been started.
Such a determination can be made, for example, based on whether or not the pressure in the fuel tank 10 measured by the pressure sensor 11 has increased (see "Refueling start Ts" in FIG. 3).
When the engine control unit 60 determines that refueling has started, the engine control unit 60 moves to step S600, and when it determines that refueling has not started, the engine control unit 60 repeatedly executes this process until refueling is started. In the present embodiment, when it is determined that refueling has started, the engine control unit 60 is configured to start a timer at that timing and count the refueling time.

(Step S600)
In step S600, the engine control unit 60 performs a process of determining whether or not the first pressure stabilization standby time Td1 (see “first pressure stabilization standby time Td1” in FIG. 3) has elapsed since the start of refueling. ..
The first pressure stabilization standby time Td1 is information defined as the time from the start of refueling until the pressure in the fuel tank 10 stabilizes, and is stored in advance in the storage device of the engine control unit 60.

In the present embodiment, during refueling, the inflow pressure of the fuel acting in the fuel tank 10 is satisfactorily discharged to the filler pipe 20 via the breather pipe 26, so that the closed valve 40 is closed. Even so, it is possible to stabilize the pressure in the fuel tank 10 in a relatively short time (see "First pressure stabilization standby time Td1" in FIG. 3).

When the engine control unit 60 determines that the first pressure stabilization standby time Td1 has elapsed, the engine control unit 60 shifts the process to step S800, and when it determines that the first pressure stabilization standby time Td1 has not elapsed, the engine control unit 60 performs the process in step S700. Transfer.

(Step S700)
In step S700, the engine control unit 60 performs a process of determining whether or not refueling has been completed.
Such a determination can be made, for example, by checking whether or not the pressure in the fuel tank 10 is "0" (see "Refueling end Te" in FIGS. 3 and 4).
When the engine control unit 60 determines that the refueling has not been completed, the process returns to step S600.
On the other hand, when the engine control unit 60 determines that the refueling has been completed, the engine control unit 60 ends the "abnormality diagnosis control process" without diagnosing the opening / closing abnormality of whether or not the closed valve 40 is out of order. This is because the pressure in the fuel tank 10 becomes "0" when the refueling is completed, and it is not possible to diagnose the opening / closing abnormality of the closed valve 40 after that (see FIG. 4).

(Step S800)
In step S800, the engine control unit 60 performs a process of moving (opening) the closed valve 40 from the “closed position” to the “open position”.
As shown in FIGS. 1 and 3, when the closed valve 40 is normally opened by this process, the epabo gas in the fuel tank 10 is discharged from the evaporative gas supply path 30 in addition to the breather pipe 26 (two systems). The pressure in the fuel tank 10 will decrease (“sealed valve open T1” in FIG. 3). In this case, the pressure in the fuel tank 10 drops to a predetermined pressure and then stays flat (stable).
As shown in FIGS. 1 and 2, the engine control unit 60 performs a process of opening the closed valve 40, and then shifts the process to step S900.

(Step S900)
In step S900, the engine control unit 60 performs a process of determining whether or not the pressure in the fuel tank 10 measured by the pressure sensor 11 is fluctuating (decreasing).
As described above, the pressure in the fuel tank 10 usually decreases when the closed valve 40 is opened, but the pressure decreases (varies) even when the closed valve 40 is controlled to be opened. If not, the closed valve 40 will fail (“open failure” and / or “closed failure”) due to dust biting or the like (see “sealed valve“ open failure and closed failure ”” in FIG. 3).
When the engine control unit 60 determines that the pressure in the fuel tank 10 has fluctuated (decreased), the process is transferred to step S1200, and when it is determined that the pressure has not fluctuated (decreased), the process is transferred to step S1000. note that. The process of step S900 corresponds to the "diagnosis step" described in the claims.

(Step S1000)
In step S1000, the engine control unit 60 performs a process of determining that the closed valve 40 has a failure (“open failure” and / or “closed failure”).
After determining the abnormality of the closed valve 40 as described above, the engine control unit 60 shifts the process to step S1100.

(Step S1100)
In step S1100, the engine control unit 60 performs a process of outputting a notification signal indicating that the closed valve 40 has a failure (“open failure” and / or “closed failure”) to the warning lamp 61. As a result, the warning lamp 61 is turned on, and the occupant or the like can recognize that the sealing valve 40 is out of order.
The engine control unit 60 ends the "abnormality diagnosis control process" after performing the process of turning on the warning lamp 61. The engine control unit 60 performs a process for closing the closed valve 40 (for example, output of a command signal related to the valve closing) just in case before ending the "abnormality diagnosis control process". Is preferable. This is because the closed valve 40, which has been closed due to dust biting or the like, may suddenly open for some reason (for example, vibration).

(Step S1200)
The engine control unit 60 determines in step S1200 whether or not the second pressure stabilization standby time Td2 (see “second pressure stabilization standby time Td2” in FIG. 3) has elapsed since the closed valve 40 was opened. Perform processing.
The second pressure stabilization standby time Td2 is information defined as the time from the opening of the closed valve 40 to the stabilization of the pressure in the fuel tank 10, and is stored in advance in the storage device of the engine control unit 60. Is.
When the engine control unit 60 determines that the second pressure stabilization standby time Td2 has elapsed, the engine control unit 60 shifts the process to step S1500, and when it determines that the second pressure stabilization standby time Td2 has not elapsed, the engine control unit 60 performs the process in step S1300. Transfer.

(Step S1300)
In step S1300, the engine control unit 60 performs a process of determining whether or not refueling has been completed.
Such a determination can be made, for example, by checking whether or not the pressure in the fuel tank 10 is "0" (see "Refueling end Te" in FIGS. 3 and 5).
When the engine control unit 60 determines that the refueling has not been completed, the process returns to step S1200.
On the other hand, when the engine control unit 60 determines that the refueling has been completed, the engine control unit 60 shifts the process to step S1400.

(Step S1400)
In step S1400, the engine control unit 60 performs a process of moving (closing) the closed valve 40 from the “open position” to the “closed position”.
The engine control unit 60 does not perform a process such as step S1600 described later (a process of determining whether or not the closed valve 40 is "open failure") after performing a process of closing the closed valve 40. , End this "abnormality diagnosis control process". This is because when the refueling is completed (“Yes” in “Step S1300”), the pressure in the fuel tank 10 becomes “0”, and thereafter, the open / closed abnormality of the closed valve 40 is diagnosed. This is because it cannot be done (see FIG. 5).

(Step S1500)
In step S1500, the engine control unit 60 performs a process of moving (closing) the closed valve 40 from the “open position” to the “closed position”.
As shown in FIGS. 1 and 3, when the closed valve 40 is normally closed by this process, the epabo gas in the fuel tank 10 is not supplied to the canister 50 via the evaporator gas supply path 30 (breatherer). (Because it returns to the discharge from only the pipe 26), the pressure in the fuel tank 10 will increase (see "sealed valve closed T2" in FIG. 3). In this case, the pressure in the fuel tank 10 rises to the pressure before opening the closed valve 40 (see "sealed valve open T1" and "sealed valve closed T2" in FIG. 3), and then the pressure at that time. Similar to the transition, it has been flat (stable transition).
As shown in FIGS. 1 and 2, the engine control unit 60 performs a process of closing the closed valve 40, and then shifts the process to step S1600.

(Step S1600)
In step S1600, the engine control unit 60 performs a process of determining whether or not the pressure in the fuel tank 10 measured by the pressure sensor 11 is fluctuating (rising).
As described above, the pressure in the fuel tank 10 normally rises when the closed valve 40 is closed, but the pressure rises (fluctuation) even when the closed valve 40 is controlled to be closed. If not, it means that the closed valve 40 is open and stuck due to dust biting or the like (“open failure” that does not move from the “open position” to the “closed position”) (FIG. 3 “sealed valve“ open failure ”). ""reference). In this respect, it can be said that the process of step S1600 is a process of diagnosing whether or not the closed valve 40 is "open failure".
When the engine control unit 60 determines that the pressure in the fuel tank 10 is fluctuating (rising), the process is transferred to step S1900, and when it is determined that the pressure is not fluctuating (rising), the processing is transferred to step S1700. note that. The process of step S1600 corresponds to the "diagnosis step" described in the claims.

(Step S1700)
In step S1700, the engine control unit 60 performs a process of determining that the closed valve 40 has "open failure" (does not move to the "closed position").
After determining "closed failure", the engine control unit 60 shifts the process to step S1800.

(Step S1800)
In step S1800, the engine control unit 60 performs a process of outputting a notification signal indicating that the closed valve 40 is "open failure" to the warning lamp 61. As a result, the warning lamp 61 is turned on. As described above, when a warning lamp for open failure is provided in addition to the warning lamp 61, the warning lamp for open failure may be turned on. As a result, the occupant or the like can recognize that the closed valve 40 is "open failure".
The engine control unit 60 ends the "abnormality diagnosis control process" after performing a process of turning on the warning lamp 61 (or an open failure warning lamp).

(Step S1900)
In step S1900, the engine control unit 60 performs a process of determining that the closed valve 40 is in the "normal" state.
After determining that the engine control unit 60 is "normal", the engine control unit 60 ends the "abnormality diagnosis control process". In this embodiment, the notification is made (the warning lamp 61 is lit) only when the closed valve 40 is out of order. However, even when the closed valve 40 is in the "normal" state, steps S1100 and It is also possible to perform a process such as step S1800. In this case, a notification means (for example, a display means such as a lamp or a liquid crystal display device and a sound generation means such as a speaker) may be separately provided to indicate that the sealing valve 40 is “normal”.

As described above, in the present embodiment, it is configured to diagnose the opening / closing abnormality of the closed valve 40 based on the transition of the pressure in the fuel tank 10 at the time of refueling.

In this respect, the fuel tank system 1 according to the present embodiment is configured to diagnose an opening / closing abnormality of the closed valve 40 by using the pressure in the fuel tank 10 that fluctuates at the time of refueling. Therefore, a negative pressure pump or the like is used. It can be said that even a vehicle not equipped with the above device can reliably perform this without being affected by the properties of the fuel or the like.

Therefore, according to the fuel tank system 1 according to the present embodiment, it is possible to reliably diagnose the opening / closing abnormality of the closed valve 40 in any vehicle.

Further, in the present embodiment, the closed valve 40 is controlled to be opened and closed during refueling, and the opening / closing abnormality of the closed valve 40 is diagnosed based on the transition of the pressure in the fuel tank 10 at that time. It is configured in.
That is, in the present embodiment, if the pressure in the fuel tank 10 decreases (rises) when the valve opening control (valve closing control) of the closed valve 40 is performed, it is "normal", and if it does not change, it is "abnormal". It has come to be diagnosed.
In this respect, in the present embodiment, the diagnostic criteria for open / closed abnormalities of the closed valve 40 are simple and clear, and the control at the time of diagnosis is not complicated, so that there is no risk of erroneous judgment and highly accurate diagnostic results can be obtained. It can be said that it can be done.

Moreover, in the present embodiment, since the breather pipe 26 for discharging the evaporator gas in the fuel tank 10 at the time of refueling is provided in the filler pipe 20, the fuel tank 10 is used when diagnosing an opening / closing abnormality of the closed valve 40. It is possible to stabilize the pressure inside.
Therefore, in the present embodiment, the pressure in the fuel tank 10 can be stabilized while the diagnosis of the opening / closing abnormality of the closed valve 40 is performed, so that the diagnosis can be performed with higher accuracy.

In this embodiment, after the "open failure" and / or "closed failure" of the closed valve 40 is diagnosed (see "step S900" in FIG. 2), the "open failure" is diagnosed ("open failure" in FIG. 2). Although "step S1600" and "step S1700") have been performed, it is possible to omit the diagnosis of this "open failure". In this case, it is sufficient to collectively diagnose that the sealing valve 40 is out of order.

Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the essays and drawings which form a part of the disclosure of the present invention according to this embodiment. That is, it should be added that all other embodiments, examples, operational techniques, etc. made by those skilled in the art based on this embodiment are of course included in the scope of the present invention.

1: Fuel tank system, 10: Fuel tank, 11: Pressure sensor, 20: Filler pipe, 20A: Fuel inlet, 21: Filler cap, 26: Breather pipe, 30: Evapo gas supply path, 31: Full tank control valve, 32: Branch pipeline, 33: Rollover valve, 40: Sealed valve, 50: Canister, 51: Purge passage, 60: Engine control unit, 61: Warning lamp, 62: Refueling request switch, Ts: Refueling start, Te: Refueling completed, T1: Sealed valve open, T2: Sealed valve closed, Td1: 1st pressure stabilization standby time, Td2: 2nd pressure stabilization standby time

Claims (5)

A fuel tank that stores fuel and
A fuel supply path for supplying fuel to the fuel tank and
A canister that adsorbs the fuel evaporative gas generated in the fuel tank,
A fuel evaporative gas supply path that connects the fuel tank and the canister and supplies the fuel evaporative gas in the fuel tank to the canister.
An open / close control valve provided in the pipeline of the fuel evaporative gas supply path and movable between an open position that allows supply of the fuel evaporative gas to the canister and a closed position that shuts off the fuel evaporative gas supply.
A discharge path that connects the fuel tank and the fuel supply path and can discharge the fuel evaporative gas in the fuel tank to the fuel supply path when the fuel is supplied to the fuel tank.
A pressure measuring device that can measure the pressure inside the fuel tank,
A control device that controls the opening and closing of the on-off control valve,
Equipped with
The control device is
Diagnosis of opening / closing abnormality of the opening / closing control valve is performed based on the transition of the pressure in the fuel tank measured by the pressure measuring device when the fuel is supplied to the fuel tank via the fuel supply path.
The vehicle's fuel tank system is characterized by that. The control device is
The open / close control valve is controlled to open / close when the fuel is supplied to the fuel tank, and the open / close abnormality of the open / close control valve is diagnosed based on the transition of the pressure in the fuel tank when the open / close control is performed. ,
The vehicle fuel tank system according to claim 1. The control device is
Based on the transition of the pressure in the fuel tank when the open / close control for moving the open / close control valve from the closed position to the open position is performed, the open / close abnormality of the open / close control valve is diagnosed.
The vehicle fuel tank system according to claim 2. The control device is
Diagnosis is made as to whether or not the on-off control valve is in the closed position from the open position based on the transition of the pressure in the fuel tank when the on-off control is performed to move the on-off control valve from the open position to the closed position. ,
2. The vehicle fuel tank system according to claim 2 or 3. It is an abnormality diagnosis method for diagnosing abnormalities in the fuel tank system of a vehicle.
The fuel tank system is
A fuel tank that stores fuel and
A fuel supply path for supplying fuel to the fuel tank and
A canister that adsorbs the fuel evaporative gas generated in the fuel tank,
A fuel evaporative gas supply path that connects the fuel tank and the canister and supplies the fuel evaporative gas in the fuel tank to the canister.
An open / close control valve provided in the pipeline of the fuel evaporative gas supply path and movable between an open position that allows supply of the fuel evaporative gas to the canister and a closed position that shuts off the fuel evaporative gas supply.
A discharge path that connects the fuel tank and the fuel supply path and can discharge the fuel evaporative gas in the fuel tank to the fuel supply path when the fuel is supplied to the fuel tank.
A pressure measuring device that can measure the pressure inside the fuel tank,
Equipped with
The abnormality diagnosis method is
Includes a diagnostic step of diagnosing an open / close abnormality of the open / close control valve based on the transition of the pressure in the fuel tank measured by the pressure measuring device when the fuel is supplied to the fuel tank via the fuel supply path. ,
An abnormality diagnosis method characterized by this.

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