JP2001206082A - Device for controlling evaporated gas in fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the flow rate in a control valve with ease. SOLUTION: A valve device 34 comprising a large caliber oil supply valve 30 and a small caliber pressure relief valve 32 provided in parallel with each other is arranged at a portion on the fuel tank body side in a breather line 28 connecting the fuel tank body 10 and a canister 26. The caliber of the oil supply valve 30 is adjusted to the size allowing the flow rate of the evaporated gas passing through the oil supply valve 30 to become the flow rate that allows the pressure relief of the fuel tank body 10 to complete in a specified time, and the caliber of the pressure relief valve 32 is set to the size allowing the flow rate of the evaporated gas passing through the pressure relief valve 32 to be limited to the flow rate which allows it to be able to be sucked in the canister 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for suppressing evaporative gas in a fuel tank, and more particularly to an apparatus for suppressing evaporative gas in a fuel tank mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, in an apparatus for suppressing an evaporative gas in a fuel tank mounted on a vehicle such as an automobile, evaporative gas (vapor) is recovered in a communication passage connecting an intake passage of the engine and the fuel tank (see FIG. 1). There is an apparatus having an evaporative gas collecting apparatus (canister) for adsorbing and holding, an example of which has already been filed by the applicant of the present invention (Japanese Patent Application No. 11-3).
29272: not disclosed).

[0003] As shown in FIG. 3, in the fuel gas evaporative gas suppressing device, a control valve disposed in parallel with a fuel supply vapor line 106 extending from a float valve 102 provided in a fuel tank body 100 to a canister 104. 1
08 and a relief valve 110 are provided, and when the internal pressure of the fuel tank main body 100 becomes a positive pressure equal to or higher than a predetermined value, the control valve is controlled by an output signal from the control circuit 114. 108 is opened, and the fuel tank main body 10 is opened.
The internal pressure of 0 is reduced.

[0004]

However, in this fuel tank evaporative gas suppression device, the control device 114
The opening time of the control valve 108 is duty-controlled to limit the flow rate of vaporized gas (vapor flow rate) per unit time passing through the control valve 108 to a predetermined value or less.
As a result, there is a problem that the flow control in the valve device 112 is complicated.

An object of the present invention is to provide an apparatus for suppressing evaporative gas in a fuel tank, which can easily control the flow rate of a control valve in consideration of the above fact.

[0006]

According to a first aspect of the present invention, there is provided a fuel tank in which a control valve that opens during refueling is provided in a passage connecting a fuel tank body and an evaporative gas collecting device. The apparatus is characterized in that the control valve is constituted by a fuel supply valve and a pressure release valve arranged in parallel, and the pressure release valve has a smaller diameter than the fuel supply valve.

Therefore, by selectively opening or closing the large-diameter oil supply valve and the small-diameter pressure release valve, respectively, the flow control of the control valve can be easily performed.

According to a second aspect of the present invention, in the fuel tank evaporative gas suppressing device according to the first aspect, the diameter of the fuel supply valve is determined by controlling a flow rate of the evaporative gas passing through the fuel supply valve. Characterized in that the flow rate is such that the pressure can be released within a predetermined time.

Therefore, in addition to the contents described in claim 1,
By opening the fueling valve, the pressure release of the fuel tank main body can be completed within a predetermined time.

According to a third aspect of the present invention, in the first aspect of the present invention, the diameter of the pressure relief valve is determined by controlling the flow rate of the vaporized gas passing through the pressure relief valve. The size is limited to a flow rate that can be adsorbed in the gas collecting device.

Therefore, in addition to the contents described in claim 1,
When the pressure release valve is opened, the flow rate of the evaporative gas that can pass through the pressure release valve is limited to a flow rate that can be adsorbed in the evaporative gas collection device, depending on the size of the diameter of the pressure release valve. As a result, hydrocarbons contained in the evaporative gas can be reliably adsorbed in the evaporative gas collection device.

According to a fourth aspect of the present invention, in the fuel gas evaporating apparatus for a fuel tank according to the first aspect, the fuel supply valve is opened after the pressure release valve is opened. .

Therefore, in addition to the contents described in claim 1,
When the internal pressure of the fuel tank body when opening the control valve is high, the evaporative gas flows from the fuel tank main body side to the evaporative gas collection device side through a relatively small-diameter pressure release valve. The contained hydrocarbon can be reliably adsorbed in the evaporative gas collecting device. In addition, after the pressure release valve is opened and the internal pressure of the fuel tank body is reduced, the relatively large diameter fuel supply valve is opened, so that the opening force of the fuel supply valve can be reduced and the pressure release valve is opened. Later, since the relatively large-diameter fuel supply valve is opened to allow the evaporative gas to flow from the fuel tank main body to the evaporative gas collecting device, the time required to release the pressure of the fuel tank main body (from the fuel tank main body side to the evaporative gas collecting device) Time of evaporative gas flowing to the side).

According to a fifth aspect of the present invention, in the first aspect of the present invention, the fuel supply valve is closed while the vehicle is running.

Therefore, in addition to the contents described in claim 1,
By closing the refueling valve while the vehicle is running, it is possible to suppress the flow of the evaporative gas from the fuel tank body side to the evaporative gas collecting device side more than necessary.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an apparatus for suppressing evaporative gas in a fuel tank according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, in the evaporative gas suppressing apparatus for a fuel tank according to 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 supply 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. . During refueling, when the fuel level in the inlet pipe 12 rises and a sensor provided on 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 the fuel lid 1 is opened.
Lid opening / closing device 20 for holding 8 in the closed position
Are arranged. This fuel lid opening and closing device 20
Is composed of, for example, a solenoid, a motor, etc.
It is connected to a control device (ECU) 22. The control device 22 is connected to a fuel lid opening / closing operation switch 23 disposed in the vehicle interior. When the occupant turns on the fuel lid opening / closing operation switch 23, the control device 22 sends an open signal to the fuel lid opening / closing device 20. Is sent, and the fuel lid 18 is opened.

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

As shown in FIG. 2, the diameter R of the refueling valve 30 is
1 is set so that the flow rate of the evaporative gas passing through the refueling valve 30 can be adjusted to a flow rate at which the pressure release of the fuel tank body 10 is completed within a predetermined time, and when the refueling valve 30 is opened during refueling. In this case, refueling is not hindered by the ventilation resistance of the evaporated 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 evaporative gas passing through the pressure release valve 32 to a flow rate that can be adsorbed in the canister 26,
When only the pressure release valve 32 is opened, the pressure release valve 3
The flow rate of the evaporative gas that can pass through the pressure release valve 32 is limited to a flow rate that can be adsorbed in the canister 26 depending on the size of the aperture of No. 2.

The refueling valve 30 and the pressure release valve 32 are each constituted by an electromagnetic valve that is controlled to be opened and closed by the control device 22. Even if the refueling valve 30 is in the closed state, if the pressure release valve 32 is opened. , And the breather line 28 communicate with each other. In the refueling valve 30, the valve body 42 closes the breather line 28 by a built-in spring 40 when the fuel supply valve 30 is off (when power is not supplied).
Similarly, also in the pressure release valve 32, the valve body closes the breather line 28 by a built-in urging means (not shown) when the pressure release valve 32 is off (when power 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 decreases, the fuel supply valve 3
0 is opened. The control device 22
The fuel supply valve 30 and the pressure release valve 32 are closed during running of the vehicle, for example, when the vehicle speed sensor detects a vehicle speed equal to or higher than a predetermined value.

A passage 36 bypassing the control valve 34
Has a relief valve 38 constituted by a diaphragm valve.
The relief valve 38 communicates with the negative pressure chamber 38A side of the relief valve 38 with the canister side 35 of the control valve 34.

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

Although not shown, the canister 26
Is connected to a surge tank communicating with the air cleaner by a purge line, and a D-VSV (duty, vacuum switching valve) is disposed in an intermediate portion of the purge line. This makes it possible to purge the canister 26 using the negative pressure of the surge tank. The canister 26 is provided with an atmospheric valve (not shown).

A pressure sensor 60 for detecting the internal pressure of the fuel tank main body 10 is provided on the upper wall of the fuel tank main body 10, and the pressure sensor 60 detects the internal pressure of the fuel tank main body 10 and detects the pressure. The value (data) is sent to the control device 22. Further, a pump unit 66 is disposed inside the inner tank shell 26, and a fuel supply pipe 68 to the engine is connected to the pump unit 66.

Next, the operation of the present embodiment will be described.

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

(1) When the vehicle is parked When the vehicle is parked, that is, when the ignition switch of the vehicle is turned off, the control device 22 is turned off and the refueling valve 30 is turned off.
And the pressure release valve 32 is closed, but when the internal pressure on the fuel tank main body side becomes larger 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 smaller than the predetermined pressure, the relief valve 38 is closed,
If it is larger than this, the relief valve 38 is opened. Therefore, the evaporated gas flows from the fuel tank main body side to the canister side, and it is possible to prevent the internal pressure of the fuel tank main body 10 from becoming a predetermined value or more during parking.

(2) While the vehicle is running When the vehicle is running, for example, when the ignition switch is turned on, the control device 22 determines that the vehicle is in the running state, and the control unit 22 determines that the refueling valve 30 is in the closed state and the pressure is released. The pressure relief valve 32 of the valve 32 having a relatively small diameter is first opened. For this reason, 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 diameter of the pressure release valve 32. As a result, the hydrocarbon contained in the evaporative gas is removed from the canister 2.
6 can reliably adsorb.

Next, when the internal pressure of the fuel tank body 10 detected by the pressure sensor 60 falls below a predetermined value, the fuel supply valve 30 having a relatively large diameter is also opened. As a result, the opening force of the fuel supply valve 30 can be reduced, and the pressure release valve 32
After opening the valve, the fuel valve 30 having a relatively large diameter is opened to flow the evaporative gas from the fuel tank main body side to the canister side, so that the time required for releasing the pressure of the fuel tank main body 10 (from the fuel tank main body side) The time required for the evaporative gas to flow out to the canister side) can be reduced.

Further, when the internal pressure of the fuel tank main body 10 detected by the pressure sensor 60 becomes the atmospheric pressure (at the time when the pressure release ends) or when the vehicle speed detected by the vehicle speed sensor becomes equal to or higher than a predetermined value (running starts). At the time), only the refueling valve 30 is closed by the control device 22. As a result,
Since the fuel tank main body 10 and the canister 26 are communicated only by the pressure release valve 32, it is possible to suppress the unnecessarily outflow of the evaporative gas from the fuel tank main body side to the canister side.

(3) During refueling When the fuel lid opening / closing operation switch 23 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 diameter. For this reason, the flow rate of the evaporative gas that can pass through the pressure release valve 32 depends on the size of the diameter of the pressure release valve 32.
In step 6, the flow rate is limited to the adsorbable flow rate. As a result, hydrocarbons contained in the evaporative gas can be reliably adsorbed in the canister 26.

Next, when the internal pressure of the fuel tank body 10 detected by the pressure sensor 60 becomes equal to or less than a predetermined value, the control device 22 also opens the refueling valve 30 having a relatively large diameter. As a result, the opening force of the fuel supply valve 30 can be reduced, and the time required for releasing the pressure of the fuel tank main body 10 (evaporation gas outflow time from the fuel tank main 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 becomes the atmospheric pressure, the control device 22 operates the fuel lid opening / closing device 20 to open the fuel lid 18 to enable refueling. On this occasion,
Since the large-diameter refueling valve 30 is open, the airflow resistance from the fuel tank main body 10 to the canister 26 is small, and refueling can be performed quickly.

When the refueling is completed, the fuel lid 18 is turned off.
Is closed, and when a fuel lid blockage detection switch (not shown) is turned on, the control device 22 determines that refueling has been completed, and closes the pressure release valve 32 and the refueling valve 30.

It should be noted that the determination of the start of fuel supply and the end of fuel supply is not necessarily made by the fuel lid operation open / close switch 2.
3. It is not necessary to perform the operation using the fuel lid obstruction detection switch. That is, since the cap 16 is removed during refueling, the cap 16 may be detected to determine the start and end of refueling. The determination of the start of fueling and the end of fueling may be made based on a signal from a switch or the like for detecting the open / closed state of the fuel lid 18.

Accordingly, in the evaporative gas suppressing apparatus according to the present embodiment, the flow rate of the control valve 34 is controlled by selectively opening or closing the large-diameter oil supply valve 30 and the small-diameter pressure release valve 32, respectively. Control is easy.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are included within the scope of the present invention. It is clear to a person skilled in the art that is possible. For example, the configuration of the refueling valve 30 or the pressure release valve 32 is not limited to the configuration of the present embodiment, but may be another configuration having a large-diameter refueling valve and a small-diameter pressure releasing valve disposed in parallel. The configuration of the valve 38 is not limited to the configuration of the present embodiment.

[0040]

According to the first aspect of the present invention, there is provided a fuel tank evaporative gas suppressing apparatus in which a control valve that opens during refueling is provided in a passage connecting a fuel tank body and an evaporative gas collecting apparatus. Since the valve is composed of an oil supply valve and a pressure release valve arranged in parallel, and the pressure release valve is smaller in diameter than the oil supply valve, the control valve has an excellent effect that the flow rate can be easily controlled.

According to a second aspect of the present invention, there is provided the fuel tank evaporative gas suppressing apparatus according to the first aspect, wherein the diameter of the fuel valve is such that the flow rate of the evaporative gas passing through the fuel valve is released from the pressure of the fuel tank body. Is of such a size that the flow rate can be completed within a predetermined time, so that in addition to the effect described in claim 1, there is an excellent effect that the pressure release of the fuel tank body can be completed within a predetermined time.

According to a third aspect of the present invention, in the first aspect of the present invention, the diameter of the pressure release valve is determined by the flow rate of the evaporative gas passing through the pressure release valve. Since the flow rate is limited to the amount that can be adsorbed, the excellent effect that hydrocarbons contained in the evaporative gas can be surely adsorbed in the evaporative gas collecting device in addition to the effect according to claim 1. Having.

According to a fourth aspect of the present invention, in the first aspect, the fuel supply valve is opened after the pressure release valve is opened. In addition to the above effects, the hydrocarbon contained in the evaporative gas can be reliably adsorbed in the evaporative gas collecting device, the opening force of the oil supply valve can be reduced, and the time required for releasing the pressure in the tank body can be reduced. It has an excellent effect that it can be shortened.

According to a fifth aspect of the present invention, in the fuel gas evaporative emission control device according to the first aspect, the fuel supply valve is closed while the vehicle is running. In addition, there is an excellent effect that the evaporation gas can be prevented from flowing more than necessary from the fuel tank body side to the evaporation gas collection device side.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view showing a control valve in the evaporative gas suppression device for a fuel tank according to one embodiment of the present invention.

FIG. 3 is a configuration diagram showing a conventional apparatus for suppressing evaporative gas in a fuel tank.

[Explanation of symbols]

Reference Signs List 10 fuel tank body 22 control device 26 canister (evaporative gas collecting device) 28 breather line (passage connecting fuel tank main body and evaporative gas collecting device) 30 refueling valve 32 pressure release valve 34 control valve 38 relief valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F16K 31/06 385 B60K 15/02 L F-term (Reference) 3D038 CA25 CA27 CB01 CC01 CC05 CC14 3G044 BA16 CA16 CA17 EA17 FA03 FA04 FA24 FA32 GA06 3H059 AA02 AA12 BB05 CB02 CB04 CB13 CB15 CC02 CD03 CD11 CE04 CE05 DD13 EE01 FF05 3H106 DA07 DA22 DB02 DB12 DB32 DC06 EE45 KK17

Claims (5)

[Claims] An evaporative gas suppression device for a fuel tank, wherein a control valve that opens during refueling is provided in a passage communicating the fuel tank body and the evaporative gas collecting device, wherein the control valve is disposed in parallel. And a pressure release valve, wherein the pressure release valve has a smaller diameter than the refueling valve. 2. The fuel supply valve according to claim 1, wherein a diameter of the fuel supply valve is such that a flow rate of the evaporative gas passing through the fuel supply valve is a flow rate at which the pressure release of the fuel tank body is completed within a predetermined time. Item 2. An evaporative gas suppression device for a fuel tank according to Item 1. 3. The pressure relief valve according to claim 1, wherein a diameter of the pressure relief valve limits a flow rate of the evaporative gas passing through the pressure relief valve to a flow rate that can be adsorbed in the evaporative gas collecting device. 3. The apparatus for suppressing evaporative gas of a fuel tank according to 1. 4. The apparatus according to claim 1, wherein the fuel supply valve is opened after the pressure release valve is opened. 5. The apparatus according to claim 1, wherein the fuel supply valve is closed while the vehicle is running.