JP3391326B2 - Evaporation gas suppression device for fuel tank - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank evaporative emission control device, and more particularly to a fuel tank evaporative emission control device mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, in an evaporative emission control device for a fuel tank equipped in a vehicle such as an automobile, evaporative emission (vapor) is collected in the middle of a communication passage that connects an intake passage of an engine and a fuel tank. Some have an evaporative gas collecting device (canister) for adsorbing and holding), and an example thereof is described in JP-A-8-112279.

As shown in FIG. 3, in this fuel tank evaporative emission control system, when the fuel supply switch 102 is operated prior to the fuel supply to the fuel tank body 100,
Under the control of the electronic control unit 104, the solenoid valve 106 is opened and the compressor 108 is operated so that the vaporized gas in the fuel tank main body 100 is sent into the reservoir 114 via the pipes 110, 112 and the canister 113, and then, When the internal pressure of the fuel tank body 100 detected by the pressure sensor 116 becomes equal to or lower than the atmospheric pressure, the solenoid valve 1
When 06 is closed, the operation of the compressor 108 is stopped and the fuel lid 118 is opened so that refueling is possible, thereby reducing the emission of evaporated gas into the atmosphere during refueling.

[0004]

However, in this fuel tank evaporative emission control device, for example, the solenoid valve 10 is used.
If 6 is left closed due to a failure or the like, the passage from the fuel tank main body 100 to the reservoir 114 via the canister 113 will be blocked. As a result, the evaporated gas in the fuel tank main body 100 cannot be sent to the reservoir 114 via the canister 113, and the tank internal pressure cannot be lowered, so that refueling becomes substantially impossible.

In view of the above facts, the present invention makes it possible to reduce the tank internal pressure even when the control valve arranged in the passage that connects the fuel tank body and the evaporative gas collector does not open during refueling. It is an object of the present invention to provide an evaporative emission control device.

[0006]

According to a first aspect of the present invention, a control valve that opens during refueling is provided in a passage that connects the fuel tank body and the evaporative gas collecting device, and the control valve opens during refueling. In a fuel tank evaporative emission control device for reducing the internal pressure of the fuel tank body by a valve, a communication device for communicating the fuel tank with the evaporative emission gas collecting device when the engine is driven, and the control valve does not open when refueling. In this case, an engine driving means for driving the engine is provided.

Therefore, when the control valve does not open during refueling and the internal pressure of the fuel tank body does not drop, the engine is driven by the engine drive means. As a result, the communication device brings the fuel tank and the evaporative emission gas collecting device into communication with each other. Therefore, even when the control valve is not opened during refueling, the evaporated fuel gas in the fuel tank main body can be sent to the evaporated gas collector, so that the internal pressure of the fuel tank main body can be lowered.

According to a second aspect of the present invention, in the fuel tank evaporative emission control device according to the first aspect, the control valve is an electromagnetic valve, and the communication device has a passage bypassing the electromagnetic valve and the passage. And a negative pressure chamber of the diaphragm valve communicated with a downstream side of the solenoid valve.

Therefore, when the solenoid valve does not open during refueling and the internal pressure of the fuel tank body does not drop, the engine is driven by the engine drive means. As a result, the diaphragm valve can be opened by the negative pressure of the intake air of the engine, and the fuel tank and the evaporative emission gas collector are in communication with each other. Therefore, even if the solenoid valve does not open during refueling,
Since the evaporated fuel gas in the fuel tank main body can be sent to the evaporated gas collector, the internal pressure of the fuel tank main body can be lowered.

According to a third aspect of the present invention, in the fuel tank evaporative emission control device according to the first or second aspect, the engine driving means can confirm that the vehicle is in a braking state. The engine is driven only when

Therefore, in addition to the contents of claim 1 or claim 2, the engine is driven only when it is confirmed that the vehicle is in a braking state, so that the safety is improved. You can

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a fuel tank evaporative emission control device according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, in the fuel tank evaporative emission control system of the present embodiment, one end of an inlet pipe (fuel filling pipe) 12 penetrates a side wall of a fuel tank body 10. The end of the inlet pipe 12 is inserted into the fuel tank body 10. The other end of the inlet pipe 12 reaches a fuel filler port 14 provided in the vehicle side wall 13.

A refueling cap 16 is attached to the refueling port 14. When refueling, the fuel lid 18 is opened and the refueling cap 16 is removed, so that a refueling gun (not shown) can be inserted. . When the fuel level in the inlet pipe 12 rises during refueling and the sensor provided in the refueling gun detects a full state, refueling from the refueling gun is automatically stopped (auto stop). . In addition, the fuel lid 18 is automatically opened on the vehicle side wall portion 13, and at the same time, the fuel lid 1 is opened.
Fuel lid opening / closing device 20 for holding 8 in the closed position
Is provided. This fuel lid switchgear 20
Is composed of, for example, a solenoid and a motor,
It is connected to the control device 22. The control device 22 is an engine driving means and can output an engine drive signal and an engine stop signal to an engine control device (not shown). Further, the control device 22 is connected to a fuel lid opening / closing operation switch 23 arranged in the vehicle interior, and when the operator turns on the fuel lid opening / closing operation switch 23, the control device 22 is turned on.
Sends an open signal from the fuel lid switchgear 20,
The fuel lid 18 is designed to open. Also,
A ventilation pipe 24 is arranged in the inlet pipe 12.

A control valve 34 having a large diameter refueling valve 30 and a small diameter pressure release valve 32 is provided at a portion of the breather line 28, which serves as a passage connecting the fuel tank body 10 and the canister 26, on the fuel tank body side. Are arranged in parallel.

As shown in FIG. 2, the diameter R of the oil supply valve 30 is R.
1 is set to a size such that the flow rate of the vaporized gas passing through the refueling valve 30 can be set to a flow rate at which the pressure release of the fuel tank main body 10 is completed within a predetermined time. When the refueling valve 30 opens, The refueling is not hindered by the ventilation resistance of the vaporized gas from the fuel tank body side to the canister side. The diameter R2 of the pressure release valve 32 is set to a size that limits the flow rate of the vaporized gas passing through the pressure release valve 32 to a flow rate that can be adsorbed in the canister 26, and only the pressure release valve 32 is opened. In this case, the flow rate of the evaporative gas that can pass through the pressure release valve 32 is limited to the flow rate at which the canister 26 can adsorb it, depending on the size of the pressure release valve 32.

The refueling valve 30 and the pressure release valve 32 are electromagnetic valves each of which is controlled to be opened and closed by the control device 22. Even if the refueling valve 30 is in the closed state, the pressure release valve 32 opens. The breather line 28 is communicated. In the refueling valve 30, the valve body 42 closes the breather line 28 by the built-in spring 40 when it is off (when the power is not supplied).
Similarly, also in the pressure release valve 32, the valve body closes the breather line 28 by a built-in biasing means (not shown) when the pressure release valve 32 is off (when electricity is not supplied).

The control device 22 opens the pressure release valve 32, and after the internal pressure of the fuel tank main body 10 drops, the refueling valve 3
It is designed to open 0. In addition, the control device 22
While the vehicle is traveling, for example, when the vehicle speed sensor 70 detects a vehicle speed equal to or higher than a predetermined value, the refueling valve 30 and the pressure release valve 32 are closed.

A passage 36 bypassing the control valve 34 is also provided.
Includes a relief valve 38 composed of a diaphragm valve.
Is provided for bypass passage 36 and relief valve 3
A communication device 39 is constituted by 8 and. Also, the relief valve 3
The negative pressure chamber 38 </ b> A side of No. 8 is communicated with the canister side 35 of the control valve 34.

A float valve 50 and a cutoff valve 52 are arranged in parallel at the opening of the breather line 28 inside the fuel tank body.
Is arranged at a position where it is closed when the tank is full, and the cutoff valve 52 is arranged at a position where it is not closed when the tank is full.

Although not shown, the canister 26
Is connected by a purge line to a surge tank which is in communication with the air cleaner, and a D-VSV (duty, vacuum switching valve) is arranged in the middle of the purge line. As a result, the canister 26 can be purged using the negative pressure of the surge tank. Further, the canister 26 is provided with an atmosphere valve (not shown).

A pressure sensor 60 for detecting the internal pressure of the fuel tank body 10 is arranged on the upper wall of the fuel tank body 10. The pressure sensor 60 detects the internal pressure of the fuel tank body 10 and detects it. A value (data) is sent to the control device 22. Further, a pump unit 66 is arranged inside the fuel tank body 10, and a fuel supply pipe 68 to the engine is connected to the pump unit 66.

In addition to the vehicle speed sensor 70, the control device 22 is also connected to an AT mission position detection switch 72 and a side brake position detection switch 74 to control vehicle speed data, AT mission position data, and side brake position data. It is adapted to be input to the device 22.

Next, the operation of this embodiment will be described.

For convenience of explanation, the operation will be described separately for (1) vehicle parking, (2) vehicle traveling, and (3) refueling.

(1) While the vehicle is parked, that is, when the ignition switch of the vehicle is off, the control device 22 is turned off and the refueling valve 30 is turned on.
And the pressure release valve 32 is closed, but when the internal pressure on the fuel tank main body side becomes higher than the internal pressure on the canister side by a predetermined value or more, the relief valve 3 is released due to this pressure difference.
8 opens. That is, when the internal pressure of the fuel tank body 10 is lower than the predetermined pressure, the relief valve 38 is closed,
If larger than this, the relief valve 38 is opened. Therefore, it is possible to prevent the vaporized gas from flowing from the fuel tank main body side to the canister side and prevent the internal pressure of the fuel tank main body 10 from exceeding a predetermined value during parking.

(2) While the vehicle is traveling When the vehicle is traveling, for example, when the ignition switch is turned on, the control device 22 determines that the vehicle is in the traveling state, and the refueling valve 30 in the valve closed state and the pressure release. Of the valves 32, the pressure release valve 32 having a relatively small diameter is first opened. Therefore, the flow rate of the evaporative gas that can pass through the pressure release valve 32 is limited to the flow rate that can be adsorbed in the canister 26 depending on the size of the pressure release valve 32. As a result, the hydrocarbon contained in the vaporized gas can be transferred to the canister 2.
It can be surely adsorbed in 6.

Next, when the internal pressure of the fuel tank main body 10 detected by the pressure sensor 60 becomes a predetermined value or less, the oil supply valve 30 having a relatively large bore is also opened. As a result, the opening force of the refueling valve 30 can be reduced and the pressure release valve 32
After opening the valve, the refueling valve 30 having a relatively large diameter is opened to allow the vaporized gas to flow from the fuel tank main body side to the canister side. Therefore, the time required to release the pressure of the fuel tank main body 10 (from the fuel tank main body side) It is possible to shorten the evacuation gas outflow time to the canister side.

Further, when the internal pressure of the fuel tank body 10 detected by the pressure sensor 60 becomes atmospheric pressure (at the time of ending the pressure release) or when the vehicle speed detected by the vehicle speed sensor becomes a predetermined value or more (running starts). At times), only the refueling valve 30 is closed by the control device 22. As a result,
Since the fuel tank body 10 and the canister 26 are communicated with each other only by the pressure release valve 32, it is possible to prevent the evaporative gas from flowing out from the fuel tank body side to the canister side more than necessary.

(3) When the fuel lid opening / closing operation switch 23 during refueling is turned on and the control device 22 determines that refueling is started, the control device 22 first opens the pressure release valve 32 having a relatively small bore. Therefore, depending on the size of the diameter of the pressure release valve 32, the flow rate of the vaporized gas that can pass through the pressure release valve 32 depends on the canister 2
In Fig. 6, the flow rate that can be adsorbed is limited. As a result, the hydrocarbon contained in the evaporated gas can be surely adsorbed in the canister 26.

Next, when the internal pressure of the fuel tank body 10 detected by the pressure sensor 60 falls below a predetermined value, the control device 22 also opens the oil supply valve 30 having a relatively large bore. As a result, the opening force of the refueling valve 30 can be reduced, and the time required for releasing the pressure in the fuel tank body 10 (the time for evaporative gas to flow from the fuel tank body side to the canister side) can be shortened.

Next, when the internal pressure of the fuel tank main body 10 detected by the pressure sensor 60 reaches the atmospheric pressure, the control device 22 operates the fuel lid opening / closing device 20 to open the fuel lid 18 to enable fuel supply.

On the other hand, the pressure sensor 6 indicates that the pressure release valve 32 or the oil supply valve 30 remains closed due to sticking, disconnection, or other failure, and the internal pressure of the fuel tank body 10 does not drop.
When 0 is detected, the control device 22 holds the fuel lid 18 in the closed position by the fuel lid opening / closing device 20 and drives the engine by the output signal from the control device 22. As a result, the relief valve 38 can be opened by the intake negative pressure of the engine, and the fuel tank main body 10 and the canister 26 are brought into communication with each other.

Therefore, even when the solenoid valve 34 does not open during refueling, the evaporated fuel gas in the fuel tank body 10 can be sent to the canister 26, so that the internal pressure of the fuel tank body 10 can be lowered. Therefore, when the internal pressure of the fuel tank main body 10 detected by the pressure sensor 60 reaches the atmospheric pressure, the control device 22 stops the engine and operates the fuel lid opening / closing device 20 to open the fuel lid 18 to enable fueling. Therefore, even when the refueling cap 16 is opened, it is possible to prevent the vaporized gas and the fuel from blowing back from the refueling port 14.

Further, the control device 22 determines the AT mission position based on the vehicle speed data from the vehicle speed sensor 70, for example, when the vehicle speed is determined to be 0 and based on the AT mission position data from the AT mission position detection switch 72. It is determined that the vehicle is in the braking state only when it is determined that the vehicle is in the parking position and when it is determined that the side brake is in the ON position based on the side brake position data from the side brake position detection switch 74. Then drive the engine. As a result, safety can be improved.

There is no malfunction in the pressure release valve 32 or the fuel supply valve 30, and the fuel supply is completed normally and the fuel lid 18
If the fuel lid blockage detection switch (not shown) is turned on, the control device 22 is closed.
Determines that the refueling is completed, and the pressure release valve 32 and the refueling valve 30
Is closed. In addition, the determination of the refueling start and the refueling end described above is not always performed by the fuel lid operation opening / closing switch 2
3. It is not necessary to use the fuel lid blockage detection switch. That is, since the cap 16 is removed during refueling, the cap 16 may be detected to determine the refueling start and refueling end. Further, the start and end of refueling may be determined by a signal from a switch or the like that detects the open / closed state of the fuel lid 18.

In the above, the present invention has been described in detail with respect to specific embodiments, but the present invention is not limited to such embodiments, and various other embodiments within the scope of the present invention. It is obvious to a person skilled in the art that For example, in the present embodiment, in the control device 22, based on the vehicle speed data from the vehicle speed sensor 70, for example, when the vehicle speed is determined to be 0, and based on the AT mission position data from the AT mission position detection switch 72, the AT The vehicle is in the braking state only when it is determined that the mission position is the parking position, and when it is determined that the side brake is in the on position based on the side brake position data from the side brake position detection switch 74. I decided to drive the engine,
When it is determined that some of these conditions are satisfied, the vehicle may be determined to be in the braking state and the engine may be driven. In addition, based on the manual mission position data from the manual mission position detection switch, combined with other determination conditions such as when the manual transmission position is determined to be in the neutral position, and when these conditions are satisfied, the vehicle is The engine may be driven by determining that the vehicle is in the braking state.

Further, in this embodiment, the fuel tank body 1
When the pressure sensor 60 detects a state where the internal pressure of 0 does not decrease, the control device 22 determines that the fuel lid opening / closing device 20
While the fuel lid 18 is held in the closed position by the above, and the engine is driven by the output signal from the control device 22, instead of this, when the pressure sensor 60 detects a state where the internal pressure of the fuel tank body 10 does not decrease. ,
The fuel lid opening / closing device 20 may only hold the fuel lid 18 in the closed position (the engine is not driven). In this case, the fuel lid 1
By holding the fuel tank main body 10 in the closed position, the operator is informed that the internal pressure of the fuel tank main body 10 is not lowered, so that the operator drives the engine for a predetermined time, and after the engine is stopped, the fuel lid opening / closing switch 23 is opened again.
The internal pressure of the fuel tank body 10 can be lowered by operating the.

The configurations of the oil supply valve 30, the pressure release valve 32, and the relief valve 38 are not limited to those of this embodiment.

[0040]

According to the first aspect of the present invention, a control valve that opens during refueling is provided in a passage that connects the fuel tank body and the evaporative emission gas collector, and the control valve opens during refueling to open the fuel tank. In a fuel tank evaporative emission control device that lowers the internal pressure of the main body, a communication device that connects the fuel tank and the evaporative emission gas collection device when the engine is driven, and an engine that drives the engine if the control valve does not open during refueling Since the drive means is provided, it has an excellent effect that the tank internal pressure can be lowered even when the control valve provided in the passage that connects the fuel tank body and the evaporative gas collector does not open during refueling. .

According to a second aspect of the present invention, in the fuel tank evaporative emission control device according to the first aspect, the control valve is an electromagnetic valve, and the communication device has a passage bypassing the electromagnetic valve and a diaphragm provided in the passage. Since the negative pressure chamber of the diaphragm valve is connected to the downstream side of the solenoid valve, the control valve installed in the passage that connects the fuel tank body and the evaporative gas collector is opened during refueling. Even if the valve is not opened, it has an excellent effect that the tank internal pressure can be lowered.

According to a third aspect of the present invention, in the fuel tank evaporative emission suppressing device according to the first aspect or the second aspect, the engine driving means has confirmed that the vehicle is in a braking state. Since the engine is driven only in such a case, it has an excellent effect that the safety can be improved in addition to the contents described in either claim 1 or claim 2.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an evaporative emission control device for a fuel tank according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a control valve in a fuel tank evaporative emission control device according to an embodiment of the present invention.

FIG. 3 is a configuration diagram showing a conventional evaporation gas suppressing device for a fuel tank.

[Explanation of symbols]

10 Fuel Tank Main Body 22 Control Device (Engine Driving Means) 23 Fuel Lid Opening / Closing Operation Switch 26 Canister (Evaporative Gas Collecting Device) 28 Breather Line (Passage Connecting the Fuel Tank Main Body and Evaporative Gas Collecting Device) 30 Refueling Valve 32 Pressure Release Valve 34 Valve device 36 Passageway (communication device) bypassing control valve 38 Relief valve (communication device) 39 Communication device 60 Pressure sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-11-125154 (JP, A) JP-A-8-121279 (JP, A) JP-A-10-47186 (JP, A) 74957 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 15/077 F02M 37/00

Claims (3)

(57) [Claims] 1. A fuel for reducing the internal pressure of the fuel tank main body by providing a control valve in a passage connecting the fuel tank main body and the evaporative gas collector with each other, the valve being opened at the time of refueling. In the evaporative emission control device for a tank, a communication device that communicates the fuel tank with the evaporative emission collector when the engine is driven, and an engine drive means that drives the engine when the control valve does not open during refueling, An evaporative emission control device for a fuel tank, comprising: 2. The control valve is an electromagnetic valve, and the communication device includes a passage that bypasses the electromagnetic valve and a diaphragm valve provided in the passage, and the negative pressure chamber of the diaphragm valve is the negative pressure chamber. The fuel tank evaporative emission control device according to claim 1, wherein the device is connected to a downstream side of the electromagnetic valve. 3. The fuel according to claim 1, wherein the engine driving means drives the engine only when it is confirmed that the vehicle is in a braking state. Evaporative gas suppressor for tanks.