JPH08244476A - Fuel flow-out preventive valve for vehicle - Google Patents

Abstract

PURPOSE: To reduce the flowing-in of a liquid fuel in a fuel tank into a canister through a fuel flow-out preventive valve, in the vertical movement or the turning of a vehicle, and to prevent the deterioration of an adsorbent. CONSTITUTION: A fuel flow-out preventive valve 31 is formed in an upper air chamber 2 of a fuel tank. In the preventive valve 31, a valve 21a is formed at the central upper part of a float 21, and a valve member 25 is composed of the valve 21a and an opening 19 having a valve seat 19a at the upper wall of a case 12. The valve 21a is formed projecting at the center of the sloping shoulder 21d of the float 21. Since the liquid fuel is not attached on the upper side of the shoulder 21d even though the valve is opened or closed, the flowing of the liquid fuel into a canister after passing through the valve member 25 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which vaporized gas in a fuel tank of an automobile or the like flows out to a canister provided on the atmosphere side and is adsorbed by an adsorbent of the canister, and when the fuel oil level rises, liquid fuel is discharged to the atmosphere side. The present invention relates to a fuel outflow prevention valve (fuel cutoff valve device) for preventing outflow to a provided canister.

[0002]

2. Description of the Related Art Conventionally, as a device for preventing atmospheric pollution by introducing and adsorbing fuel evaporative gas generated in a fuel tank of an automobile or the like into a canister containing activated carbon, as shown in FIG. There is one in which the upper portion of the air chamber portion 2 in 1 and the canister 3 are communicated with each other by a communication passage 4 (for example, Japanese Utility Model Laid-Open No. 63-7030).

In such an apparatus, when the oil level O ₁ of the liquid fuel O in the fuel tank 1 changes so as to approach the upper wall surface of the fuel tank 1 due to, for example, the tilting or falling of the vehicle body, the liquid fuel is changed. May flow out into the canister 3 through the communication passage 4, and the adsorbing performance of the adsorbent in the canister 3 may be deteriorated.

Therefore, conventionally, as shown in FIG. 6, a fuel cut-off valve device 5 is installed in the communication portion between the fuel tank 1 and the communication passage 4, and normally, the evaporative gas in the fuel tank 1 is connected to the communication passage. 4 to discharge the liquid fuel O to the adsorbent of the canister 3 and to block the passage to the communication passage 4 when the vehicle body tilts or falls as described above.

As a structure of the fuel cutoff valve device 5, for example, there is a structure shown in FIG. 7 (the structure shown in FIG. 1 of Japanese Utility Model Laid-Open No. 63-7030).

An outline of the structure and function of the first fuel cutoff valve device (hereinafter also referred to as the first prior art) shown in FIG. 7 will be described. Reference numeral 1a denotes an upper wall of the fuel tank, a part of which is opened, and a case 6 constituting the fuel cutoff valve device 5 is installed in the opening. An opening 6a having a valve seat is formed in the center of the upper wall of the case 6, a fuel inlet / outlet hole 6b is formed in the bottom wall, and a fuel evaporative gas discharge hole 6c is formed in the upper portion of the peripheral wall of the case 6. Has been formed. Then, in the case 6, the valve 7a is provided at the center of the upper surface.
The float 7 formed with is formed so as to be movable up and down. 8
Is a spring that assists the upward movement of the float 7. Four
Is a communication passage communicating with the canister 3 as described above, and its opening end 4a communicates with the communication chamber 9 communicating with the opening 6a.

Then, normally, the float 7 as shown in FIG.
Is descending due to its own weight. In this state, since the pressure inside the air chamber 2 is higher than the atmospheric pressure and the pressure inside the communication chamber 9 is almost the same as the atmospheric pressure, the fuel evaporative gas generated in the air chamber 2 due to the pressure difference is indicated by the arrow. As shown by A, it flows into the case 6 through the discharge hole 6c, is discharged into the communication passage 4 through the opening 6a and the communication chamber 9, and is introduced into the canister 3.

When the oil level O ₁ of the liquid fuel fluctuates so as to approach the upper wall 1a due to the inclination of the vehicle body or the like, the float 7
Moves up from the state shown in the figure by its buoyancy, its valve 7a blocks the opening 6a, and prevents the liquid fuel O in the fuel tank from flowing out to the communication passage 4, that is, the canister 3.

In the first fuel cutoff valve device 5, when the vehicle or the like is stopped or in a stable running state, the fluctuation of the oil level O ₁ of the liquid fuel O in the fuel tank is very small. As indicated by arrow A in FIG. 7, only the fuel evaporative gas is discharged to the communication passage 4.

However, when the vehicle is turning or running on a wavy road surface, as shown in FIG. 8, the liquid fuel O in the fuel tank sways and swells, and the liquid fuel O rushes into the case 6 and O Scatter like ₂ ,
A phenomenon occurs in which the scattered liquid fuel O ₂ flows into the case 6 through the discharge hole 6c formed in the case 6.

That is, when the pressure in the air chamber 2 becomes much higher than the atmospheric pressure due to the fluctuation of the oil level O ₁ and the temperature rise, the pressure in the case 6 which is almost the same as the atmospheric pressure and the air chamber 2
A large pressure difference is generated between the two sides, and this pressure difference generates an air flow B in the case in the discharge hole 6c, and the liquid fuel O ₂ scattered on the air flow B flows into the case 6. To do.

As described above, when the liquid fuel flows into the case 6 through the discharge hole 6c opened in the upper portion of the case 6, the liquid fuel is collected on the upper surface of the float 7 as indicated by O ₃ in FIG. Become.

The accumulated liquid fuel O ₃ falls into the gap between the outer periphery of the float 7 and the inner surface of the case 6 and returns to the inside of the fuel tank through the fuel inlet / outlet hole 6b formed in the bottom wall. Before, when the float 7 is closed and then opened by the movement of the liquid fuel in the fuel tank, the air flow in the direction toward the communication chamber 9 at the opening 6a due to the pressure difference inside the case 6 is high and inside the communication chamber 9 is low. C is rapidly generated, and the air flow C sucks the liquid fuel O ₃ accumulated on the float 7 toward the communication chamber 9 side.

When sucked in this way, the liquid fuel O ₃ is introduced into the canister 3 through the communication passage 4, and there is a drawback that the deterioration of the adsorbent in the canister is accelerated. In the case where one discharge hole 6c is formed in the upper portion in the vertical cross-sectional direction of the case 6 as in the case of the above-mentioned first conventional technique, the amount of gas flowing through the discharge hole 6c is small, so that the valve is open. In the case where the pressure in the case is close to the pressure on the air chamber side and the differential pressure is large, when the (liquid) fuel O ₂ is scattered in the discharge hole 6c, a large differential pressure is generated. As a result, the liquid fuel easily flows in through the discharge hole 6c. Furthermore, unless the differential pressure is reduced early, the liquid fuel that has entered through the fuel inlet / outlet hole 6b formed at the bottom of the case 6 is pushed upward and tends to accumulate on the upper surface of the float 7. Therefore, the above drawbacks are likely to occur.

Therefore, the applicant of the present application proposes in Japanese Patent Application No. 5-234757 a second fuel cut-off valve device which prevents the liquid fuel from flowing into the upper surface of the float as described above and eliminates the above drawbacks. And has been producing.

Next, the second fuel cutoff valve device will be described with reference to FIG. Reference numeral 10 denotes an upper wall of the fuel tank installed on the vehicle body.

Reference numeral 31 is a fuel cutoff valve device, which is a flange portion 1 formed on the outer periphery of the upper end of a cylindrical case 12.
3 is engaged with the upper surface of the peripheral edge of the mounting hole formed in the upper wall 10 of the fuel tank, and its case 12 is provided in the air chamber portion 2 of the fuel tank.

The flange portion 13 is pressed by the gasket 15 and the cover 16, and the gasket 15 and the cover 16 are held.
Is fixed to the upper wall 10 of the fuel tank to prevent gas leakage at the collar 13.

An upper wall 12a is integrally formed with the case 12, and a communication chamber 9 is formed between the upper wall 12a and a portion where the cover 16 is bent upward, and the communication chamber 9 is formed.
To the open end 4a of the communication passage 4. An opening 19 having a valve seat 19a at the bottom is formed at the center of the upper wall 12a of the case.

A bottom lid 20 is fitted on the bottom of the case 12, and a fuel inlet / outlet hole 20a is formed in the bottom lid 20. Reference numeral 21 denotes a float that can be raised and lowered in the case 12, and a valve 21a facing the valve seat 19a is formed at the center of the upper surface of the float. The outer diameter of the float 21 is smaller than the inner diameter of the case 12, and a gap D is formed between them.

Thus, the opening 1 having the valve seat 19a
9 and the valve 21a constitute a valve portion 25, and the valve portion 25 is set at a position higher than the mounting upper wall surface 10 of the fuel tank.

Reference numeral 12b denotes a ridge formed on the inner circumference of the case 12 in order to keep the gap D uniform over the entire circumference of the float 21. The projections 12b extend in the vertical direction at intervals along the circumference of the case 12. Existence A small gap is provided between the inner ends of these ridges and the outer peripheral surface of the float 21 so that the float 21 can easily move up and down.

Reference numeral 22 is a compression coil spring interposed between the bottom lid 20 and the float 21 and assists the upward movement of the float 21. Reference numeral 23 denotes an upper discharge hole for discharging the fuel evaporative gas, which is located near the upper end of the side wall of the case 12 so as to be close to the upper wall 10 of the fuel tank, and is formed to penetrate the case 12 inward and outward. A plurality of upper discharge holes 23 are formed in the circumferential direction of the case 12.

Reference numeral 24 denotes a lower discharge hole for discharging the fuel evaporative gas, which is higher than the position of the buoyancy point 21b in the closed state of the float 21 and which is opposed to the lowered side surface (outer peripheral surface) 21g of the float 21. In the case, the case 12 is formed so as to penetrate inward and outward. In the illustrated embodiment, the valve 21a is formed slightly above the buoyancy point 21b in the closed state. Also, the lower discharge hole 24
Are formed in the circumferential direction of the case 12.

Further, the total opening area of the lower discharge holes 24 is set larger than the total opening area of the upper discharge holes 23.
In the illustrated embodiment, one opening area of the lower discharge holes 24 is made larger than one opening area of the upper discharge holes 23 so that the total opening area of the lower discharge holes 24 becomes the total opening area of the upper discharge holes 23. It is larger than the area.

The total flow area of the gap D between the case 12 and the float 21 (annular flow area) is set larger than the total opening area of the lower discharge holes 24. When the oil level O ₁ of the liquid fuel O in the fuel tank is below the fuel cutoff valve device 31 as shown in FIG. 10 while the automobile or the like is stopped or in a stable running state, the float 21 is caused by its own weight. In the lowered state, the valve 21a is separated from the valve seat 19a, and the opening 19 is in the opened state. At this time, since the communication passage 4 side is substantially atmospheric pressure and the air chamber portion 2 side is higher than atmospheric pressure, the fuel evaporative gas in the air chamber portion 2 due to the pressure difference is in the upper discharge hole 23 and the lower discharge hole 24.
Into the case 12, is discharged into the communication passage 4 through the opening 19 and the communication chamber 9, is introduced into the canister 3, and is adsorbed by the adsorbent in the canister.

Next, when the float 21 is in the valve open state as described above, the liquid fuel O in the fuel tank is largely shaken and swells due to the turning of the automobile or the traveling of the wavy road surface, and the liquid fuel rushes to the case 12. The case of scattering will be described.

The pressure of the air chamber 2 in the fuel tank is the case 1
If the pressure is higher than the pressure in the case 2 and there is a pressure difference between them, gas (fuel vapor) flows into the case 12 from the side of the air chamber 2 through both discharge holes 23, 24, and the pressure in the case 12 becomes It approaches the pressure of part 2.

At this time, compared with the first prior art in which only the discharge hole having the same total opening area as the discharge hole 23 is formed, the pressure in the case 12 is increased faster, and the differential pressure is decreased faster. To do. Therefore, the flow rate of the gas flowing into the case 12 from the air chamber portion 2 side in the upper discharge hole 23 becomes smaller than that of the conventional one, and the scattered liquid fuel is discharged from the upper discharge hole 23 by the air flow to the case. Less is sucked into 12. As a result, the amount of liquid fuel accumulated on the upper surface of the float 21 also decreases.

Also in the lower discharge hole 24, similarly to the above, the scattered liquid fuel is rarely sucked by the air flow, but the lower discharge hole 24 is formed below the upper discharge hole 23 and is opened. Due to the large area,
It is easy for the scattered liquid fuel to directly flow in.

However, from the lower discharge hole 24 to the case 12
The liquid fuel that has flowed in hits the outer wall surface (outer peripheral surface) of the float 21, falls along the outer wall surface, and returns into the fuel tank from the fuel inlet / outlet hole 20 a formed in the bottom lid 20. At this time, as described above, the differential pressure decreases rapidly, and the position of the lower discharge hole 24 is located far below the upper surface of the float 21.
It is extremely rare that the liquid fuel that has flowed into the inside 2 is pulled up to the upper surface of the float 12 by riding on the air flow that flows toward the opening 19 side. Further, by making the total flow area of the gap D larger than the total opening area of the lower discharge holes 24, the above-mentioned pulling up of the liquid fuel is further prevented.

As described above, the fact that the amount of the liquid fuel accumulated on the upper surface of the float 21 is small means that the float 21 temporarily closes the opening 19a by the movement of the liquid fuel and then opens to cause a pressure difference in the opening 19a. Even if the air flow toward the communication chamber 9 is rapidly generated due to, the amount of the liquid fuel flowing out to the communication chamber 9 side decreases, and as a result, the liquid fuel introduced into the canister 3 through the communication passage 4 also decreases.

Next, the operation of locating the lower discharge hole 24 above the position of the buoyancy point 21b when the float 21 is closed will be described. Temporarily lower discharge hole 24
Considering the case where the float 21 is positioned below the position of the buoyancy point 21b in the valve open state, the oil level O of the liquid fuel is
Before ₁ reaches the buoyancy point 21b of the float 21, the lower discharge hole 24 is immersed in the liquid fuel and blocked. At that time, since the opening 19 is opened, the pressure difference between the inside of the case 12 and the air chamber 2 becomes large. When the oil level O ₁ of the liquid fuel is undulated in the state where the pressure difference is large, the air and the fuel rise in the gap D between the case 12 and the float 21 while being mixed, and the liquid fuel is deposited on the upper surface of the float 21. It accumulates or is discharged from the opening 19.

On the other hand, the lower discharge hole 24 is provided with the float 2
If it is located above the position of the buoyancy point 21b in the valve closed state of No. 1, even if the oil surface O ₁ of the liquid fuel reaches the buoyancy point 21b and the valve 21a closes the opening 19, the lower discharge hole 24 is not blocked by liquid fuel. Then, even if the oil surface O ₁ of the liquid fuel swells and the liquid fuel flows in from the lower discharge hole 24, there is almost no pressure difference because the opening 19 is closed, and an ascending air current is generated in the gap D. By not doing so, the liquid fuel is less likely to be accumulated on the upper surface of the float 21 and discharged from the opening 19.

Next, the operation of the discharge hole 23 other than the function of discharging the fuel evaporative gas will be described. Temporarily upper discharge hole 23
Considering the case in which there is no bottom hole and only the lower discharge hole 24 is formed, at the same time when the liquid fuel hits the case 12, the float 21 vibrates and the opening 19a temporarily opens, and the liquid fuel flows in from the lower discharge hole 24. And its lower discharge hole 24
When the float 21 moves upward and the opening 19a is closed after flowing into the upper clearance D, the float 21
Since the upper space is closed, even if the oil level of the liquid fuel descends, the liquid fuel in the gap D remains without being removed. Therefore, when the float 21 descends and the opening 19 is opened thereafter, the residual liquid fuel is sucked into the communication chamber 9 due to a large pressure difference between the communication chamber 9 and the case 12. become.

On the other hand, if the upper discharge hole 23 is formed, the upper space of the float 21 is not sealed even in the above case, and the liquid fuel that has flowed into the gap D rapidly descends, Therefore, it is not sucked into the communication chamber 9.

Therefore, if the lower discharge hole 24 mainly controls the function of discharging the fuel evaporative emission gas, the upper discharge hole 23
May be a hole having an opening area small enough to prevent the above-mentioned sealing. Therefore, the total opening area of the upper discharge holes 23 can be set to be smaller than the total opening area of the upper discharge holes 6c of the first fuel cutoff valve device 31, whereby the inflow of scattered liquid fuel is also possible. It can be prevented further.

The relationship between the opening areas of the upper discharge hole 23 and the lower discharge hole 24 is such that one opening area of the lower discharge hole 24 is equal to or smaller than one opening area of the upper discharge hole 23. In some cases, the number of lower discharge holes 24 may be larger than the number of upper discharge holes 23, and the total opening area of the lower discharge holes 24 may be set larger than the total opening area of the upper discharge holes 23.

[0039]

[Problems to be Solved by the Invention]
Also in the related art, when the vehicle moves up and down or makes a sharp turn, the liquid fuel enters the case 12 through the upper discharge port 23 and the lower discharge hole 24, and the float 21 is submerged and the opening 1 is opened.
After 9 is closed, when turning etc. are finished and the valve is opened again,
The liquid fuel remaining in the space above the float 21 and the opening 19 is communicated with the communication passage 4 by the tank internal pressure higher than that in the atmosphere chamber 9.
However, there is a problem that the adsorbent deteriorates due to flowing into the canister.

Therefore, it is a first object of the present invention to provide a fuel outflow prevention valve for a vehicle which can solve the above problems. Further, in the first and second prior arts, the floats 7 and 21 may rotate around their vertical axes due to the vibration of the vehicle, and the valves 7a and 21a may become valve seats of the openings 6a and 19. There is also a problem that when the float rotates while contacting 19a or the like to close the valve, these contact parts slide and wear, and the reliability of the fuel outflow prevention valve deteriorates.

Therefore, the second object of the present invention is to solve this problem and achieve the first object.

[0042]

In order to achieve the first object, the invention of claim 1 provides a fuel tank (1) for a vehicle.
A valve part provided in the upper air chamber (2) of the fuel tank (1) which is normally opened to communicate the evaporated fuel in the fuel tank (1) with the canister containing the adsorbent and which is closed by the rise of the float (21). (25) A fuel outflow prevention valve having a case (1) in which the float (21) is vertically movable
2) is provided in the upper air chamber (2) of the fuel tank (1), and an upper discharge hole (23) which is located at the upper side and communicates with the inside and outside of the case is formed in the side wall of the case (12). Hole (2
3) a lower discharge hole (24) which is located below the case and communicates with the inside and outside of the case is formed, and the upper portion of the float (21) holding the valve (21a) formed at the upper end of the float (21) is stroked over the shoulder (21d). ) Is a fuel outflow prevention valve for a vehicle.

According to the present invention, the amount of liquid fuel flowing from the upper air chamber (2) of the fuel tank into the case (12) is reduced due to the vertical movement and turning of the vehicle, and further, the liquid fuel flows into the case (12). The inflowing liquid fuel rarely stays on the shoulder (21d) in the upper part of the float (21).

A second aspect of the present invention is the invention of the first aspect, wherein the lower end portion (21) of the shoulder (21d) of the float upper portion is covered.
f) is positioned below the upper discharge hole (23) and above the lower discharge hole (24).

In the present invention, the liquid fuel flowing into the case (12) from the lower discharge hole (24) is changed to the float (2).
Fewer rides on the upper shoulder (21d) of 1). According to the invention of claim 3, in the invention of claim 1 or 2, the lower discharge hole (24) is located above the buoyancy point (21b) of the float (21) at the closed position of the fuel outflow prevention valve, and It is characterized in that it is formed at a position facing the side surface (21g) of the float (21).

In the present invention, even when the oil surface of the liquid fuel reaches the buoyancy point (21b) and the opening (19) is closed by the valve (21a), the lower discharge hole (24) is in the liquid state. Not blocked by fuel. Therefore, when the valve portion (25) is opened, the lower discharge hole (24) is closed by the liquid fuel, and the liquid fuel in the gap (D) between the case (12) and the float (21) is pushed up. Prevents riding on the shoulder (21d).

A fourth aspect of the present invention is any one of the first to third aspects of the invention, wherein the total opening area of the lower discharge holes (24) is
It is characterized in that it is set larger than the total opening area of the upper discharge holes (23).

In the present invention, the case (12) of the evaporated fuel
The inflow is mainly made in the lower discharge hole (24), the liquid fuel is less inflowed from the upper discharge hole (23) into the case (12), and the shoulder portion (21) of the float (21) is
The amount of liquid fuel riding on d) is further reduced.

A fifth aspect of the present invention is characterized in that, in any one of the first to fourth aspects, the inclined surface of the shoulder portion (21d) of the float (21) is at least two inclined surfaces. It is a thing.

In the present invention, the shoulder portion (21d) is formed by appropriately selecting the slopes of the plurality of inclined surfaces forming the shoulder portion (21d).
d) The liquid fuel above can be effectively reduced. According to a sixth aspect of the invention, in order to achieve the second object, the shoulder portion (21d) of the float (21) is provided with a radial groove (21e) extending in the radial direction of the float (21). A fuel outflow prevention valve for a vehicle according to any one of claims 1 to 5.

In the present invention, the liquid fuel flowing down along the radial grooves (21e) suppresses the rotation of the float (21) due to the vibration of the vehicle.

[0052]

1 and 2 show the first and second embodiments of the present invention, respectively.
3A and 3B show a third embodiment of the present invention.
Elements having the same functions as those of the second conventional technique shown in FIG. 10 are designated by the same reference numerals, and their description will be omitted.

In the first embodiment shown in FIG. 1, the upper shoulder portion of the float (21) holding the papillary valve 21a formed on the upper end portion of the float 21 is formed on the shoulder 21d. In the first embodiment, the shoulder portion 21d is formed of a part of a conical shape, and the valve 21a is formed so as to project from the center upper portion thereof. Further, the lower end (outer periphery) of the shoulder portion 21d is, as indicated by the reference numeral 21f,
At the lower limit position of the float 21, it is located below the upper discharge hole 23 and above the lower discharge hole 24.

The shoulder portion 21d is not limited to the conical shape having one inclined surface (tapered surface) as in the first embodiment shown in FIG. 1, but may be formed by connecting a plurality of conical surfaces. (Claim 5).

In the second embodiment of FIG. 2, the shoulder portion 21d is formed by a part of an elliptical surface which is convex upward. A spherical surface may be used instead of the elliptical surface. In the third embodiment of FIG. 3, four grooves 21e extending in the radial direction of the float 21 are radially formed on the shoulder portion 21d of the shoulder that is formed of a conical surface, and as described above, the rotation of the float due to the vibration of the vehicle is prevented. This prevents the sliding wear of the valve 21a and the valve seat 19a that form the valve portion 25.

In order to confirm the effect of the embodiment, as shown in FIG. 4, the fuel tank 26 is filled to the full, and as shown by an arrow α around the fulcrum 27, both amplitudes of 44 ° in the vertical direction about the horizontal line X are provided. When the amount of liquid fuel discharged from the fuel outflow valve 31 to the graduated cylinder 29 is measured by rocking in the range of
The leakage ratio could be reduced to 20% of the conventional technology.

[0057]

Since the fuel outflow prevention valve for a vehicle according to the present invention is constructed as described above, even when the float rises and closes due to vertical movement or turning of the vehicle, the valve portion or the float is closed. Since there is almost no liquid fuel adhering to the shoulder portion of the container, the liquid fuel hardly flows to the canister side when the valve is opened immediately after. Therefore, deterioration of the adsorbent of the canister is prevented, and reliability is improved.

Further, according to the invention of claim 6, sliding wear of the valve portion is prevented, so that the reliability (life) of the fuel outflow prevention valve is improved also from this aspect.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a second embodiment of the present invention.

FIG. 3 (a) is a longitudinal sectional view of the third embodiment of the present invention,
(B) is a plan view (top view) of the float.

FIG. 4 is a schematic diagram of a model device for testing the effect of a fuel spill valve.

FIG. 5 is a bar graph showing the difference in effect between the conventional technology and the present invention.

FIG. 6 is a schematic diagram of an air pollution control device for a vehicle.

FIG. 7 is a vertical sectional view of a first conventional technique.

FIG. 8 is a diagram of a different aspect of FIG. 7.

FIG. 9 is a view of a different aspect from FIG. 7.

FIG. 10 is a vertical sectional view of a second conventional technique.

[Explanation of symbols]

 1 Fuel Tank 2 Upper Air Chamber 12 Case 21 Float 21a Valve 21b Buoyancy Point 21d Shoulder (Nude Shoulder) 21e Groove 21f Lower End 23 Upper Discharge Hole 24 Lower Discharge Hole 25 Valve

Claims (6)

[Claims] 1. A valve portion provided in an upper air chamber of a fuel tank of a vehicle, which is normally opened to communicate the evaporated fuel in the fuel tank with a canister containing an adsorbent and to be closed by rising of a float. A fuel outflow prevention valve comprising: a case in which the float is housed so as to be able to move up and down is provided in an upper air chamber of a fuel tank, and an upper discharge hole for communicating the inside and outside of the case is provided on the side wall of the case. A vehicle, characterized in that a lower discharge hole is formed below the upper discharge hole to communicate the inside and outside of the case, and the upper portion of the float for holding the valve formed at the upper end of the float is formed on the shoulder. Fuel spill prevention valve. 2. The fuel outflow prevention valve for a vehicle according to claim 1, wherein the lower end of the shoulder of the float upper portion is located below the upper discharge hole and above the lower discharge hole. 3. The lower discharge hole is formed at a position above the buoyancy point of the float at the valve closing position of the fuel outflow prevention valve and at a position facing the side surface of the float. The fuel outflow prevention valve for the vehicle described. 4. The fuel outflow prevention valve for a vehicle according to claim 1, wherein the total opening area of the lower discharge holes is set larger than the total opening area of the upper discharge holes. 5. The fuel outflow prevention valve for a vehicle according to claim 1, wherein the inclined surface of the shoulder portion of the float is composed of at least two inclined surfaces. 6. The shoulder of the float is provided with radial grooves extending in the radial direction of the float.
5. The fuel outflow prevention valve for a vehicle according to any one of 1 to 5.