JP3291899B2 - Float valve 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 float valve for a fuel tank which is disposed above a fuel tank and allows air in the fuel tank to flow out during refueling.

[0002]

2. Description of the Related Art Conventionally, a float valve of this type is known from Japanese Patent Application Laid-Open No. 5-185850 and Japanese Utility Model Publication No. 4-39061, and has a structure as shown in FIG.

That is, the float valve V0 comprises a cylindrical case 1 having a bottom and a float 4 housed in the case 1.
A valve portion 5 disposed above the float 4 and capable of closing the air outflow channel 7, and a compression coil spring 6 disposed between the float 4 and the bottom wall 2 of the case 1. The case 1 was fixed to the upper wall 9 of the fuel tank 8.

In the case 1, a bottom wall 2 and a side wall 3 are provided so that fuel F and air A can flow into the case 1.
The through holes 2a and the ventilation holes 3a were formed.

[0005] The coil spring 6 is an auxiliary member that assists the float 4 so as to close the air outflow channel 7 when the vehicle leans or falls. That is, for example, when the vehicle is reversed, the air outflow channel 7 is located below the float 4, and the sum of the mass of the float 4 and the urging force of the spring 6 at that time is equal to the float 4. The spring load of the spring 6 is set so as to be larger than the buoyancy. Of course, the spring load of the spring 6 does not cause the float 4 to rise so as to close the air outflow channel 7 before the fuel F rises when the vehicle is in a proper posture. When immersed in F, the sum of the buoyancy of the float 4 and the urging force of the spring 6 is set to a range in which the mass of the float 4 is larger than the mass of the float 4.

Therefore, in this type of float valve V0, when the liquid level of the fuel F in the fuel tank 8 rises at normal times, the fuel F flows into the case 1 through the through holes 2a and the ventilation holes 3a. Since the float 4 rises, it is possible to prevent the valve portion 5 from closing the air outflow channel 7 and causing the fuel F to flow out of the tank 8. The air that has passed through the air outflow channel 7 is sent to a canister (not shown).

[0007]

However, in the conventional float valve V0, when fuel F is supplied to the fuel tank 8, a large amount of fuel F is supplied in a short time.
The following problems have occurred.

That is, at the time of refueling, the air A
The air A flows rapidly into the case 1 from the ventilation hole 3a and flows out from the air outflow channel 7, so that the flow of the air A becomes lift and the float 4 rises. Make Then, in that state, Case 1
When the fuel F flows into the case 1 from the through hole 2a of the bottom wall 2 and the float 4 rises due to the buoyancy of the fuel F,
Before the liquid level of the fuel F rises to the fuel liquid level LF at which the float 4 is arranged at the appropriate valve closing position when the tank is full,
In some cases, the flow of the air A causes the valve portion 5 to close the air outflow channel 7. This valve closing operation occurs especially when the float 4 is generating buoyancy due to the fuel F, because the downward force (the value obtained by subtracting the buoyancy and the urging force from the mass) of the float 4 is small. easy.

[0009] Such a valve closing operation suddenly stops the flow of the air discharged to the outside of the fuel tank 8 during refueling, so that the internal pressure of the fuel tank 8 sharply increases, and the fuel pressure increases. The following problem occurs on the fuel injection side of the tank 8.

That is, although a gradual increase in the internal pressure of the fuel tank does not cause a problem, the rapid increase in the internal pressure of the fuel tank 8 as described above causes a backflow of the fuel to the fuel injection port side, and the fuel injection. Since the gun suddenly activates the auto-stop mechanism which operates by detecting the internal pressure of the fuel tank at a certain value or more and stops the refueling, a predetermined amount of fuel cannot be supplied, which is not desirable.

As a countermeasure, it is conceivable to provide a check valve or the like on the fuel inlet side as described in Japanese Utility Model Laid-Open No. 137033/1988, but the number of parts of the fuel tank is increased. Not preferred.

The present invention has been made to solve the above-mentioned problems, and it is possible to prevent a rapid increase in the internal pressure of a fuel tank and to control the internal pressure in a stepwise manner when fuel is supplied to the fuel tank. It is another object of the present invention to provide a fuel tank float valve capable of smoothly filling a tank with fuel.

[0013]

A first fuel tank float valve according to the present invention is arranged at an upper portion of a fuel tank and has at least a bottom wall and a side wall extending upward from a peripheral edge of the bottom wall. And a case in which a vent hole is formed in the side wall, a float housed in the case, a valve disposed at an upper portion of the float and capable of closing an air outflow channel, and a case bottom. An auxiliary member disposed between the wall and the float, for assisting the valve closing movement of the float, comprising: a float valve for a fuel tank that allows air in the fuel tank to flow out during refueling, The valve body is made of rubber, and has a base portion attached to the upper portion of the float, and a disk-shaped seal portion protruding radially outward from an upper end of the base portion and capable of being pressed against the entire periphery of the air outflow channel. And An air hole vertically penetrating is formed at a position inside the sealing portion at a position pressed against the periphery of the air outflow channel, and the float is disposed at an upper portion below the sealing portion to form the sealing portion. A plate-shaped valve seat capable of closing the ventilation hole of the seal portion at the time of pressing the outer peripheral edge of the seal portion, and a mounting portion of the base portion disposed at the center of the valve seat. It is a feature.

[0014] A second fuel tank float valve according to the present invention is arranged at an upper portion of the fuel tank and has at least a bottom wall and a side wall extending upward from a peripheral edge of the bottom wall. A case in which a vent is formed in the case, a float housed in the case, a valve body disposed on the float and capable of closing an air outflow channel, and a case bottom wall and the float. An auxiliary member disposed between the fuel tank and an auxiliary member for assisting the valve closing movement of the float. And a cylindrical portion extending vertically and having a vent hole, and an umbrella-shaped seal portion extending radially outward at the upper end of the cylindrical portion and capable of closing the air outflow channel. , Said float on top, in front A holding portion for holding the cylindrical portion so as to be movable downward, a valve seat capable of closing a ventilation hole of the cylindrical portion below the cylindrical portion, and a lower end surface of the cylindrical portion when the cylindrical portion is separated from the valve seat. And a ventilation hole that can communicate with the ventilation hole, wherein a spring that urges the valve body upward is disposed between the valve body and the float. It is.

[0015]

In the first float valve for a fuel tank according to the present invention, when fuel is supplied to the fuel tank, buoyancy by fuel or lift by air causes
Even if the float rises, first, the valve body seal portion is pressed against the entire periphery of the air outflow channel.

At this time, since the ventilation hole penetrates through the valve body seal portion, the air outflow channel does not become completely closed, and the air flowing into the case through the ventilation hole in the side wall of the case is blocked by the valve. It flows out through the space between the body seal portion and the valve seat of the float and through the vent hole of the valve body seal portion. Since this air outflow route flows through the vent hole formed in the valve body seal portion, the valve body seal portion is narrowed as compared to before the valve body seal portion is pressed against the periphery of the air outflow passage, and the internal pressure in the fuel tank is reduced. Will be slightly increased.

Thereafter, when the fuel further flows into the case, the float rises further by the buoyancy to deflect the valve body seal portion, and when the fuel level rises to the level of the fuel level when the tank is full, The outer peripheral edge on the lower surface side of the valve body seal portion is in contact with the valve seat of the float, and the vent hole of the valve body seal portion is closed, thereby completely closing the air outflow channel. Then, the internal pressure in the fuel tank rises to a certain value, and the automatic stop mechanism of the fuel injection gun on the side of the fuel inlet operates to stop refueling.

Therefore, in the first fuel tank float valve according to the present invention, when refueling the fuel tank,
(2) closing of the air outflow channel by the outer peripheral edge of the valve body sealing portion and closing of the ventilation hole of the valve body sealing portion by the float valve seat.
At this stage, since the air outflow passage is fully closed, the rise in the tank internal pressure can be controlled in a stepwise manner, preventing the backflow of fuel to the fuel inlet side, and ensuring a full tank refueling. Can be performed.

In the second float valve for a fuel tank according to the present invention, even when the float rises due to buoyancy by fuel or lift by air when fuel is supplied to the fuel tank, first, the valve body seal portion is first opened. It comes into pressure contact with the entire periphery of the air outflow channel.

At this time, since the ventilation hole is penetrated through the valve body cylinder and the lower end of the valve body cylinder is separated from the valve seat of the float by the spring, the air outflow passage is completely closed. However, the air flowing into the case from the ventilation hole in the case side wall flows out through the ventilation hole of the float and the ventilation hole of the valve body cylinder. Since this air outflow route flows through the vent hole formed in the valve body cylinder, the valve body seal portion is narrowed compared to before being pressed against the periphery of the air outflow passage, and the internal pressure in the fuel tank is reduced. Will be slightly increased.

Thereafter, when fuel further flows into the case, the float further rises due to buoyancy, and the valve body is moved downward relative to the float against the urging force of the spring. When the fuel level rises to the level of the fuel level at the time of the tongue, the lower end face of the valve body cylinder part comes into contact with the valve seat of the float, the vent hole of the valve body cylinder part is closed, and the air outflow passage is completely blocked. Close. Then, the internal pressure in the fuel tank rises to a certain value, and the automatic stop mechanism of the fuel injection gun on the side of the fuel inlet operates to stop refueling.

Therefore, in the second float valve for a fuel tank according to the present invention, when refueling the fuel tank,
Since the air outflow passage is completely closed in two stages, that is, the air outflow passage is closed by the outer peripheral edge of the valve body seal portion, and the vent hole of the valve body cylinder is closed by the float valve seat. The rise can be controlled in a stepwise manner, the backflow of the fuel to the fuel inlet having the liquid seal structure can be prevented, and the full tank refueling can be performed smoothly.

Further, in the second fuel tank float valve, a spring disposed between the valve body and the float is used as a means for countering the buoyancy of the float when closing the vent hole of the valve body cylinder. Is what you do. Therefore, even if the weight or shape of the float is changed in design and the buoyancy of the float is changed, it can be easily adjusted by changing to a spring having a different spring load.

[0024]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 2 and 3, a float valve V1 for a fuel tank according to the first embodiment includes a case 11, a float 15 disposed in the case 11, and a valve body 16 attached to the float 15. And a compression coil spring 17 as an auxiliary member for assisting the valve closing movement of the float 15, and is disposed on the upper wall 9 of the fuel tank 8.

The fuel tank 8 is connected to a pipe P for supplying fuel to the engine and a pipe for returning fuel F, not shown, in addition to the pipe P to the canister C. A filler pipe 8a for inserting the fuel injection gun G is provided on the fuel injection port side.

The case 11 is formed of a synthetic resin having fuel oil resistance such as polyacetal or polyamide, and has a substantially disk-shaped bottom wall 12, a cylindrical side wall 13, and a side wall 13.
Annular ceiling wall 14 extending at the upper end to the inner peripheral side and the outer peripheral side
And is provided.

The bottom wall 12 has a plurality of through holes 12a through which the fuel F flows into the case 11, and has a cylindrical rib 12b for regulating the position of the spring 17 on the upper surface.

The side wall 13 is joined to the bottom wall 12 so as to extend upward from the peripheral edge of the bottom wall 12, and has a plurality of ventilation holes 13a communicating between the inner peripheral side and the outer peripheral side.

The ceiling wall 14 is provided with a partition wall portion 14a extending to the inner peripheral side of the side wall 13 and a flange portion 14b extending to the outer peripheral side of the side wall 13. The center hole of the partition wall portion 14a is located on the canister C side. Outflow channel 1 that allows air A to flow out
It is set to 8. The flange portion 14b is provided with a float valve V
1 is fixed to the upper wall 9 of the tank. The valve V1 is attached to a base 10 welded around a mounting hole 9a of the upper wall 9 of the tank, and an upper lid 19 and a sealing material (see FIG. (Omitted), and fixed to the tank upper wall 9 by fixing the bolt 20. Top lid 19
Is fixed to a nipple 19a for connecting a pipe P connected to the canister C.

The valve body 16 is formed of a rubber material such as fluorine rubber or nitrile rubber, and has a base portion 16a attached to the upper portion of the float 15, and an air outflow passage protruding radially outward from an upper end of the base portion 16a. And a disc-shaped seal portion 16d that can be pressed against the entire periphery of the peripheral edge of the peripheral portion 18.

At the lower portion of the base portion 16a, a concave groove 16b for mounting to the mounting portion 15b of the float 15 and a bulging portion 16 are provided.
c is formed.

A plurality of ventilation holes 16e penetrating vertically are formed in the seal portion 16d at a position inside the pressure contact portion of the air outflow channel 18 with the peripheral edge.

The float 15 is formed of a synthetic resin such as polyacetal or polyamide having fuel oil resistance, and has a cylindrical main body 15a for generating buoyancy by the fuel F, and a mounting portion 15b disposed on the upper part of the main body 15a. , Is configured.

The mounting portion 15b is formed in a substantially cylindrical shape protruding upward from the upper surface of the main body 15a, and has a through hole 15c penetrating in a horizontal direction at a predetermined position. Valve body 1
The mounting of the base portion 16a of the sixth through the through-hole 1
This is performed by inserting and locking into 5c. Such a shape of the mounting portion 15b is applied to the main body 15a of the float 15.
This is because the structure of the slide core is not complicated when the mounting portion 15b and the valve seat 15d described later are integrally formed by injection molding. Further, the through hole 15c is closed by inserting and locking the bulging portion 16c.

The upper end of the mounting portion 15b of the float 15 is disposed at a predetermined distance from the lower surface of the valve body sealing portion 16d after the valve body base portion 16a is mounted on the mounting portion 15b.
A valve seat 15d extending in a disk shape is formed radially outward. On the outer peripheral edge of the upper surface of the valve seat 15d, a valve body sealing portion 15 is provided.
An annular annular projection 15e is formed so as to face the lower surface of the entire outer peripheral edge.

The coil spring 17 is disposed between the lower surface of the float main body 15a and the case bottom wall 12.

In the float valve V1 of the first embodiment, when fuel F is supplied to the fuel tank 8, the float 15 rises due to buoyancy due to the fuel F flowing into the case 11 or lift due to the air A flowing. First, as shown in FIG. 4, the valve body sealing portion 16d is
8 is pressed against the entire periphery.

At this time, since the vent hole 16e penetrates through the valve body sealing portion 16d, the air outflow channel 18 does not become completely closed, and the air outflow channel 18 is inserted into the case 11 from the vent hole 13a of the case side wall 13. The inflowing air A flows between the valve body seal portion 16d and the valve seat 15d of the float 15 and the valve body seal portion 16d.
Through the ventilation holes 16e. Since the outflow route of the air A flows through the vent hole 16e formed in the valve body sealing portion 16d, the outflow route of the air A is compared with the state shown in FIG. 3 before the valve body sealing portion 16d is pressed against the peripheral edge of the air outflow channel 18. The internal pressure (fluid pressure) in the fuel tank 8 is slightly increased.

Thereafter, when the fuel F further flows into the case 11, the float 15 further rises due to the buoyancy to deflect the valve body seal portion 16d, and as shown in FIG. When the fuel liquid level rises to the height LF, the outer peripheral edge on the lower surface side of the valve body seal portion 16d abuts against the annular projection 15e of the valve seat 15d of the float 15, and the vent hole 16e of the valve body seal portion 16d. Is closed, and the air outflow channel 18 is completely closed. Then, the internal pressure in the fuel tank 8 rises to a certain value, the auto stop mechanism of the fuel injection gun G inserted into the filler pipe 8a operates, and the refueling is stopped.

That is, in the float valve V1,
The air outflow channel 18 is completely closed in two stages, namely, the closing of the air outflow channel 18 by the outer peripheral edge of the valve body sealing portion 16d and the closing of the ventilation hole 16e of the valve body sealing portion 16d by the valve seat 15d of the float 15. Close.

Therefore, as shown in FIG. 6, the internal pressure (hydraulic pressure) is not a sudden increase in internal pressure (hydraulic pressure) shown by a broken line.
Can be controlled in two stages, the backflow of the fuel F to the filler pipe 8a side can be prevented, and the full tank refueling can be performed smoothly.

In the float valve V1, since the valve body 16 attached to the float 15 is made of rubber, the sealing performance can be improved.

In the float valve V1 of the first embodiment, the closing of the air outflow passage 18 is controlled in two stages by utilizing the bending of the valve body sealing portion 16d.
As in the float valve V2 of the second embodiment shown in FIGS.
The air outlet channel 18 may be closed in two stages by moving the valve body 26 itself. In FIGS. 7 to 9, members substantially similar to those in the first embodiment are denoted by the same reference numerals, and
The description is omitted.

The valve body 26 of the second embodiment is formed of the same rubber material as the valve body 16 of the first embodiment, and extends vertically and has a cylindrical tubular portion 26a having a vent 26b, Part 2
And an umbrella-shaped seal portion 26d extending radially outward at the upper end of 6a and capable of closing the air outflow channel 18. At the lower part of the cylindrical portion 26a, a locking projection 26c formed on the entire outer peripheral surface is formed.

The float 25 is the float 1 of the first embodiment.
5. A cylindrical main body 25a formed of the same synthetic resin as that described above and having a buoyancy generated by the fuel F, and a holding portion 25b disposed on the upper portion of the main body 25a for holding the valve body cylindrical portion 26a so as to be movable downward. And is provided.

The holding portion 25b is provided on the upper surface of the main body 25a so as to protrude upward in a cylindrical shape, and has a ventilation hole 25 penetrating in the horizontal direction.
c is formed. The ventilation hole 25c is a portion that locks the locking protrusion 26c of the valve body cylinder 26. The upper surface of the main body 25a surrounded by the holding portion 25b serves as a valve seat 25d when closing the ventilation hole 26b of the valve body cylinder 26a.

A disk-shaped spring seat 25e extending outward in the radial direction is formed at the upper end of the float holding portion 25b. The spring seat 25e is a compression spring whose upper end is in contact with the lower surface of the valve body seal portion 26d. The lower end of the coil spring 29 is supported.

In the float valve V2 of the second embodiment, when fuel F is supplied to the fuel tank 8, the float 15 rises due to buoyancy due to the fuel F flowing into the case 11 or lift due to the air A flowing. First, as shown in FIG. 8, the valve body sealing portion 26d is
8 is pressed against the entire periphery.

At this time, the ventilation hole 26 is formed in the valve body cylinder portion 26a.
b is penetrated, and the lower end of the valve body cylinder portion 26a is separated from the valve seat 25d of the float 25 by the coil spring 29, so that the air outflow passage 18 is not completely closed, and the case side wall 13 The air A flowing into the case 11 from the vent hole 13a of the valve 25 is
It flows out through the ventilation hole 26b of 6a. Since the outflow route of the air A flows through the vent hole 26b formed in the valve body cylinder portion 26a, the air A outflow route is compared with the state shown in FIG. 7 before the valve body seal portion 26d is pressed against the periphery of the air outflow channel 18. The internal pressure in the fuel tank 8 is slightly increased.

Thereafter, when the fuel F further flows into the case 11, the float 25 further rises by buoyancy,
The valve body 26 is moved downward relative to the float 25 against the urging force of the spring 29, and as shown in FIG. When the fuel level rises, the lower end surface of the valve body cylinder portion 26a comes into contact with the valve seat 25d of the float 25, the air hole 26b of the valve body cylinder portion 26a is closed, and the air outflow passage 18 is completely closed. In other words, the same operation and effect as those of the first embodiment can be obtained.

Further, in the float valve V2, a coil spring 29 disposed between the valve body 26 and the float 25 as means for countering the buoyancy of the float 25 when closing the ventilation hole 26b of the valve body cylinder portion 26a. Therefore, even if the weight and shape of the float 25 are changed in design and the buoyancy of the float 25 is changed, by changing to a spring 29 having a different spring load, the air hole 26b can be easily handled. Can be adjusted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a conventional float valve.

FIG. 2 is a cross-sectional view showing the first embodiment of the present invention, showing a state where the fuel tank is disposed in a fuel tank;

FIG. 3 is a sectional view of the same embodiment.

FIG. 4 is a sectional view showing a use state of the embodiment.

FIG. 5 is a sectional view showing a use state of the embodiment, and FIG.
Shows the state after.

FIG. 6 is a graph showing the relationship between the tank internal pressure (liquid pressure) and the liquid level (liquid level) in the embodiment and the conventional example.

FIG. 7 is a sectional view showing a second embodiment.

FIG. 8 is a sectional view showing a use state of the embodiment.

FIG. 9 is a sectional view showing a use state of the embodiment, and FIG.
Shows the state after.

[Explanation of symbols]

 1.11, Case, 2.12, Bottom wall, 3.13 ... Side wall, 3a.13a ... Vent hole, 4.15.25 ... Float, 6.17 ... (Auxiliary member) Compression coil spring, 7.18 ... Air outflow channel, 8: fuel tank, 15b: mounting portion, 15d: valve seat, 16: valve body, 16a: base portion, 16c: seal portion, 16e: vent hole, 25b: holding portion, 25c: vent hole, 25d: valve seat, 26: valve body, 26a: cylindrical portion, 26b: vent hole, 26d: seal portion, 29: compression coil spring, V0, V1, V2: float valve, F: fuel, A: air, LF ... Fuel level when full.

Continuation of front page (56) References JP-A-5-185850 (JP, A) JP-A-2-112658 (JP, A) JP-A-5-1547 (JP, U) JP-A-4-39061 (JP) , Y2) US Patent 5044389 (US, A) US Patent 5028244 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 24/00-24/06 B60K 15/00

Claims (2)

(57) [Claims] 1. A case disposed at an upper portion of a fuel tank, the case including at least a bottom wall and a side wall extending upward from a periphery of the bottom wall, and having a ventilation hole formed in the side wall; A valve disposed above the float and capable of closing an air outflow channel; disposed between the case bottom wall and the float to close the float; An auxiliary member for assisting, a fuel tank float valve for discharging air in the fuel tank at the time of refueling, wherein the valve body is made of rubber, and is attached to an upper part of the float, and A disc-shaped seal portion protruding radially outward from the upper end of the base portion and capable of being pressed against the entire periphery of the air outflow channel, and comprising: From the press-contact part of A plate through which the air hole vertically penetrates is formed at an inner position, and the float is disposed above the seal portion at an upper portion and can close the air hole of the seal portion when the outer peripheral edge of the seal portion is pressed. A float valve for a fuel tank, comprising: a valve seat in a shape of a circle; and a mounting portion of the base portion, which is provided at the center of the valve seat. 2. A case which is disposed at an upper portion of a fuel tank and includes at least a bottom wall and a side wall extending upward from a peripheral edge of the bottom wall, and a case in which a ventilation hole is formed in the side wall; A valve disposed above the float and capable of closing an air outflow channel; disposed between the case bottom wall and the float to close the float; A fuel tank float valve for discharging air from the fuel tank at the time of refueling, wherein the valve body is made of rubber and has a ventilation hole extending vertically. A cylindrical portion, and an umbrella-shaped seal portion extending radially outward at the upper end of the cylindrical portion and capable of closing the air outflow channel, wherein A holding portion for movably holding the cylinder; A valve seat capable of closing the ventilation hole of the cylindrical portion below the portion, and a ventilation hole capable of communicating with the ventilation hole of the cylindrical portion when the lower end surface of the cylindrical portion is separated from the valve seat,
A float valve for a fuel tank, wherein a spring for urging the valve body upward is disposed between the valve body and the float.