JPS5838327B2 - Vehicle fuel tank valve device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to vehicles, particularly motorcycles or tricycles, which are mounted on a vehicle body with a fuel tank exposed, so that when the vehicle falls over or collides, an external force is applied directly to the fuel tank. Concerning safety valves for vehicle fuel tanks.

Various valve devices have been proposed that close the vent to the outside air to prevent fuel from leaking to the outside when the internal pressure of the fuel tank rises above a certain level due to a collision or the like.

Also, a valve device for a fuel tank is known that closes a vent to the outside air when the vehicle overturns.

However, with conventional valves that close in the event of an overturn, if the tank is left exposed to direct sunlight in an overturned state, i.e., with the tank and outside air cut off, the temperature inside the tank will rise and the internal pressure will rise, as shown in Figure 7. As shown, the internal pressure decreases to 0.25% in a short period of time.
reach more than that.

On the other hand, the fuel tank of a normal motorcycle or three-wheeled vehicle has an inverted U-shaped cross section that straddles a central frame pipe, and is made of a metal plate with a thickness of 0.6 to 1.0 mm, and the internal pressure of the tank is As it rises, the lower open end of the inverted U shape deforms, and the displacement reaches a speed of 201n at an internal pressure of 0.25 degrees.

This amount of displacement causes a residual strain of about 4 degrees even if the internal pressure decreases, and if the residual strain is more than this, the fuel tank becomes inconvenient for the device to straddle the frame pipe, and the support of the tank becomes uncertain. Become.

An example is shown in FIG.

In order to solve this problem, a valve may be installed that opens and closes in response to the tank internal pressure to maintain the tank internal pressure at 0.25 to below.

However, in this case, fuel is allowed to eject in the event of a vehicle collision, deformation of the tank during an overturn, or a sudden increase in internal pressure due to fuel inertia, etc., and as a result, the ejected fuel ignites, causing a fire. There is a risk of causing secondary disasters such as

As shown in Figure 9, according to the results of our first experiment, the internal pressure is 0.1 to 0.3 due to the deformation of the tank and the inertia of the fuel immediately after the collision.
It reaches the maximum pressure in seconds, then drops rapidly until it reaches a certain level of residual pressure.

Moreover, this residual pressure varies from 0 to 0 depending on conditions such as tank deformation.
．． It is in the range of 41'7.0, and may be higher than the above-mentioned 0.25 tori.

As mentioned above, in the fuel tanks of motorcycles, etc., the valve device has the function of maintaining the internal pressure at a certain level when the tank is sealed, and also preventing fuel leakage as much as possible from the maximum pressure to the residual pressure in the event of a collision. can serve as a safety valve that can respond to all conditions of vehicles such as motorcycles.

The present invention has been accomplished to provide a safety valve for a fuel tank that reliably fulfills these functions and has a simple structure.

In the present invention, the problem is solved under the condition that the tank cap is sealed when the vehicle crashes or falls.

The object of the present invention is to close a fuel tank of a motorcycle or the like under normal conditions, open a communication passage when the tank internal pressure exceeds a relatively low first set value, and leak the internal pressure, and To provide a valve device which closes the communication passage again when the second set value is reached, completely seals the inside of the tank, and maintains the substantially sealed state even if the tank internal pressure drops.

Therefore, the object of the present invention is that in a fuel tank that normally has a breather for ventilation, if the tank is sealed so that the breather passage is closed when it falls over, and the internal pressure of the tank increases due to the tank being left unattended, the above-mentioned 1. Exceeding the set value causes the tank internal pressure to leak and prevents the tank from deforming beyond its elastic limit, which would occur under such conditions, and reliably maintains the tank straddling device while also preventing misalignment, falling accidents, etc. To provide a valve device for a fuel tank for a vehicle, which prevents this and improves the safety of motorcycles, etc.

Furthermore, it is an object of the present invention that when the internal pressure of the fuel tank rises abnormally, such as during a collision, the above-mentioned communication passage is immediately connected not only when the internal pressure exceeds the second set value instantaneously, but also when it does not exceed the above-mentioned second set value. Close the tank, completely sealing the tank, and completely preventing fuel from spewing out or leaking to the outside until the residual pressure reaches the limit, thereby preventing secondary disasters such as fires caused by fuel spouting or leakage in the event of a collision. The present invention provides a fuel tank valve device that contributes to improving the safety of motorcycles.

Specifically, the valve device according to the present invention includes a bottom member having a through hole communicating with the inside of the tank, and an upper member having a through hole communicating with the outside air, and a space is provided between these members.

A valve body is provided in the space, which is activated by an increase in pressure within the tank, and the valve body is pressed against the bottom member by a spring, thereby blocking communication between the inside of the tank and outside air under normal conditions, and connecting the valve body, the bottom member, and the top member A large seal part is provided on the .

As described above, when the tank internal pressure exceeds the first set value, the valve body is moved upward against the spring, communicating the inside of the tank with the outside air, preventing internal pressure leaks, and preventing deformation due to the increase in internal pressure of the tank. prevent it from happening.

When the pressure rises above the first set value and exceeds the second set value, the valve body moves upwards, completely cutting off communication between the inside of the tank and the outside air, and preventing fuel from leaking to the outside in the event of a collision. to prevent.

The present invention provides a valve device for a fuel tank having such a structure, and also provides various practical examples of the basic structure described above, practical examples of application to a tank cap, and effective sealing means for the cap.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

Further objects and advantages of the present invention will become apparent from this.

Figure 1 is a vertical sectional view showing the basic structure of the valve device, Figure 2 is a vertical sectional view of an actual case in which the valve device is applied to a fuel tank cap, and Figure 3 is a vertical sectional view of only the cap seal member. 4
The figure is a side view schematically showing the motorcycle, Figure 5 is a graph explaining the operation of the valve device according to the present invention, Figure 6 is a graph explaining the action of the cap seal, and Figure 7 is the progress when the tank is sealed. A graph explaining the relationship between time and internal pressure. Figure 8 is a graph explaining the relationship between tank internal pressure and tank deformation. Figure 9 is a graph explaining the relationship between typical tank internal pressure and time at the time of a collision. It is.

1 and 2 are examples in which FIG. 2 is applied to a cap, and the structures are completely the same except for a part, so the explanations in FIGS. 1 and 2 are the same, and the reference numerals are are also common.

As an actual example, an example of application to a fuel tank of a motorcycle is shown.

The layout of the motorcycle 1 is as shown in FIG.
A front wheel 3 is supported by a front fork 2, and a rear wheel 4 is supported by a rear fork 5 and a rear cushion unit 6.

A seat 8 is provided at the middle or rear portion of the frame 7, and a steering handle 10 is provided on the front fork 2 via a bridge 9.

A fuel tank 13 is installed in a frame pipe (not shown in the drawings) between the handle 10 and the seal 8 so as to straddle the frame pipe.

As is well known, the fuel tank 13 is made of a pressed steel plate material that is welded or brazed.

The fuel in the engine 13 is fed to a fuel supply device such as a carburetor 11, usually by gravity, and the engine 12 is fed with fuel.

The fuel tank 13 has a fuel supply port on the upper surface of its outer plate 14.

The supply port is as shown in FIG. 2, and has a substantially channel-shaped cross section and a ring-shaped mouthpiece 1 in the opening 15 on the tank outer plate 14.
6 by welding etc.

In the illustrated example, since the cap 20 is of a bayonet type,
The lower end of the inner diameter portion 17 of the cap 16 constitutes a cam.

The cap 20 is composed of an upper member 22 having a knob 21 extending upwardly in the center thereof, and a cylindrical box-shaped main body 23 that fits within the inner diameter portion 17 of the cap 16.

The upper end of the main body 23 is provided with a flange portion 24 that is located above the base 16 and extends radially outward, and is connected to the upper member 22 at a portion 25 that hangs down from the outer periphery of the flange portion 24.

An opening 26 is provided at an opposing position on the outer periphery of the intermediate portion of the main body 23.
are provided, and both ends of a locking member 27 protrude from the left and right openings 26, and the locking member 27 has a ring shape and is open in the middle.

A hemispherical protrusion 29 is provided hanging down from the center of the bottom 28 of the main body 23, and a receiving member 30 having a tapered V-shaped cross section and an inverted conical shape is fitted onto the upper side of this protrusion so that the protrusion 31 in the center fits therein. is set on the bottom 28.

A coil spring 34 is interposed between the outer peripheral portion 32 of the receiving member 30 and the receiving step portion 33 of the locking member 27.

As a result, the locking member 27 is elastically pressed upward and comes into elastic contact with the lower end of the inner diameter portion 17 of the mouthpiece, while the receiving member 30 is elastically pressed against the upper surface of the bottom portion 28 of the main body 23.

In this way, the cap 20 is pressed downward while attached to the base 16.

Then, a sealing member 80, which will be described later and which is interposed between the flange portion 24 of the main body 23 and the upper surface of the mouthpiece 16, is crimped.

A ball 36 is placed on the inverted conical tapered surface 35 of the receiving member 30, and the ball 36 has a V
Since it is shaped like an inverted cone, when the cap 20 is in its normal position, and therefore the fuel tank 13 is in its normal position, it is located at the center due to centripetal action, and when it is tilted or falls over, it is guided by the surrounding slopes and rolls in that direction. do.

Further, through holes 3T and 38 are provided in the main body 23 and the receiving member 30, so that the inside of the cap 13 and the inside of the cap main body 23 are in communication.

A valve device 40 is provided inside the cap 20 described above.

The basic structure of the valve device 40 is as shown in FIG.

A body 41 of the valve device 40 includes a bottom member 42 and an upper member 43.

The bottom member 42 has a recess 44 in the center, and the periphery of the recess 44 has a higher flange 45, which is set on the flange 24 of the cap body 23.

The portion of the upper member 43 that faces the recess 44 has a protrusion 46 that bulges upward in an annular shape, the center of the protrusion 46 has a circular concave portion 47 that protrudes downward, and the periphery of the annular protrusion 46 has a An annular recess 48 is provided, and a flange 49 that overlaps the flange 45 of the bottom member 42 is provided on the outer periphery of the annular recess 48 .

By overlapping the bottom member 42 and the top member 43 and joining them at the flange portions 45 and 49, a chamber 5 is formed in the center portion.
0 is formed.

This chamber 50 communicates with the interior of the fuel tank 13 through a through hole 51 provided near the outer periphery of the recess 44 of the bottom member 42, and with the outside air through a through hole 52 provided in the protrusion 46 of the top member 43.

A valve member 70 is interposed in the chamber 50 described above.

The valve member 70 has a diaphragm shape made of a flexible material such as rubber.

The rib 71 provided on the outer periphery of this
It fits into the ring-shaped groove 53 provided on the outer periphery, is crimped with the annular groove 48 of the upper member 43, and the flange portion 4 of the member 42.43
5.49 is shown alone in Figure 1, so rivet 5
Combined with 4.

In addition, in FIG. 2, since it was placed inside the cap 20, it was clamped with a claw 39 provided on the cap 20.

The chamber 50 is sealed by crimping the rib portion 71.

The main body 72 at the center of the valve member 70 is thick and has a ring-shaped seal lip 73 projecting downwardly from its lower surface near the outer periphery, and a ring-shaped spring receiver 74 is provided on its upper surface.

A spring 75 is compressed between this 74 and the protrusion 46 of the upper member 43 to constantly press the valve member 70 downward.

As a result, the seal lip 73 is pressed against the upper surface of the recess 44 of the bottom member 42.

In the center of the valve body 72, there is a through hole 76 that passes through the valve body 72 vertically.
will be established.

The lower end of the through hole 76 opens into a space surrounded by the seal lip 73, and the upper end faces the seat surface 55 on the lower surface of the recess 47 in the center of the upper member 43.

There is a thin bent portion 77 between the valve body 72 and the rib 71.
are connected.

As is clear from FIGS. 1 and 2, the valve body 72 is pressed downward by the downward force of the spring 75, and the seal lip 73 is pressed against the seat surface 56 at the center of the recess 44 of the bottom member 42. The upper and lower chambers 57 and 58 of the chamber 50 partitioned by the member 70 are closed during normal times because the through hole 76 is closed by the close contact between the lip 73 and the seat surface 56.

A clearance is normally provided between the seat surface 55 and the upper surface of the valve body 72.

In FIG. 2, it is installed inside the cap 20, and the flange portions 45 and 49 of the bottom member 42 and the top member 43 are clamped and integrated with the claws 39, and a ring-shaped recess 59 is formed on the lower surface of the flange portion 45 of the bottom member 42. An O-ring 60 is fitted into this part to seal it.

In the embodiment in which the valve device 40 is installed inside the cap 20, the valve device 40 includes the following parts as shown in FIG.

That is, the cylindrical holder 6 has a locking portion 62 formed by bending its lower end inwardly below the portion of the bottom member 42 having the recess 44.
1 is provided hanging protrudingly.

A cylindrical guide 63 is provided in the center of the holder 61 to project downwardly, and a through hole 76 of the valve member 70 is provided at the center of the guide 63.
A through hole 64 is provided concentrically with.

A 21-dollar type tilt-response valve 65 is fitted into the guide 63 so as to be slidable up and down. It is provided with a matching flange portion 67, and is biased in the downward movement direction by a spring 68 interposed between the lower surface of the bottom member 42 and the lower surface of the bottom member 42.

The bottom of the valve 65 is in contact with the ball 36 below.

A sealing member 80 made of rubber or the like is provided on the lower surface of the flange portion 24 forming the peripheral portion of the lower surface of the cap 20 .

The sealing member 80 is ring-shaped, as is clear from FIG. 3, in which only the sealing member 80 is shown, and its cross section is in the shape of a horizontal U-shape with the outside closed.

That is, the sealing member 80 has an upper surface of a flat upper piece 81 facing the lower surface of the flange portion 24, and has a hole 82 in the center thereof that fits into the root portion of the main body 23.

The outer periphery of the upper piece 81 is bent 83 into a U-shape and continues to the lower piece 84.

The hole 85 of the lower piece 84 has a larger diameter than the hole 82 of the upper piece 81, and the lower surface of the lower piece 84 is a flat sheet surface 86,
On the upper surface of this, a large number of projections 87 are integrally provided radially.

These protrusions 87 are in contact with the lower surface of the upper piece 81, and a clearance is created between the protrusions 87 and the upper piece 81.

As a result, a large number of spaces 88 . . . are formed radially between the two stacked pieces 81 and 84, which are closed at the bent portion 83 and open at the inner diameter portion, and as shown in FIG. The seat surface 86 of the lower piece 84 of 80 is pressed against the upper end of the cap 16, and a space 88 with a closed outer end communicating with the inside of the tank 13 is formed by the projections 87.

Next, let's explain its effect.

The basic principle of its operation will be explained with reference to FIG.

FIG. 1 shows a normal state, in which the valve body 72 is attached to a spring 75.
The lip 73 comes into contact with the seat surface 56, and therefore the upper and lower chambers 57 and 58, which are partitioned by the valve member 70 in the chamber 50, are in a state of no communication.

The pressure inside the tank is led to the lower chamber 58 from the through hole 51, and the valve member 70 is set not to move upward unless the pressure exceeds the first set value P1.

This setting is determined by selecting the spring load of the spring 75 and the pressure-receiving area of the diaphragm at the time of lower sealing.

This value is preferably selected under the conditions explained in FIG. 9 above.

The first set value P1 is 0, which is the elastic limit of the tank outer plate.
．． 25'! It is determined that the valve member 70 moves upward at the following value, for example, 0.2% pressure, and the spring load, pressure receiving area of the valve member 70, etc. are determined based on this.

Furthermore, the effect of the function and the influence of the dimensions of each part will be explained in connection with actual use.

When an external force is applied to the tank during a collision, the pressure increases instantaneously according to the collision speed, as shown in Figure 9, but as a result of many collision tests, the difference between the peak pressure and the residual pressure is It has been found that there is a certain relationship, and that when the residual pressure is equal to or higher than the first set value P1, the peak pressure always exceeds a certain value.

The second set value P2 is set below this value.

In the case of a motorcycle, for example, 0.5 to o. 7 yen, n range.

First, in the case of collision speed ■2, ■3 (residual pressure becomes larger than first set value P1), for example, the collision occurs at traveling speed ■2 or ■3, the tank is deformed, and the residual pressure becomes the first set value P1. The operation of the valve device 40 in the case where the size becomes larger is explained using a graph as shown in FIG. 5, in which the horizontal axis represents time (ms).
), and the vertical axis is the tank internal pressure (F).

The tank internal pressure is as shown by the indicator line E, and the valve member 70 closes below the first set value P1, moves upward at the first set value P1, and the lip 73 and the seat surface 56 are separated, and the upper and lower parts are separated by the through hole 76. The chambers 57, 58 communicate, ie, the inside of the tank communicates with the outside air through the through holes 51, 76, 52.

Then, at the second set value P2, the main body 72 comes into close contact with the seat surface 55, the through hole 76 is closed, and the chamber 5 connected to the through holes 51 and 52
7. 58 is blocked.

That is, the inside of the tank and the outside air are cut off. Therefore, the tank and the outside air are communicated only between p and t PZ, and the rest are not communicated.

The increase in the tank internal pressure at the time of the collision is rapid as shown by line E, and therefore the transition from P1 to P2 is also extremely rapid, and the valve is opened for an extremely small amount of time Jt during the transition from P1 to P2.

However, almost no fuel leaks to the outside during the transition from the valve opening to the valve closing, and can be suppressed to an instantaneous amount.

As time passes, the tank internal pressure returns to a certain level of residual pressure that is higher than <P1 as shown in FIG. Since the valve member 70 is larger than the valve state, at a residual pressure higher than P, the valve member 70 continues to maintain an upwardly moving state and fuel does not leak.

Next, in the case of a collision where the collision speed is lower than 1, that is, the residual pressure is lower than P1, and the tank is not deformed, the valve member 7
0 once moves upward at P1, the upper and lower chambers 57 and 58 communicate with each other, and the inside of the tank communicates with the outside air through 51, 76, and 52.
Since the peak pressure does not reach P2, the upper surface of the valve body γ2 does not come into contact with the seat surface.

During this period of communication, the fluid flows through the communication hole, so the inside of the tank, the lower chamber 58, the space inside the lip 73, and the upper chamber 57 are restricted to the aperture 51. Aperture effect of 73 parts of lip,
As a result of the throttle 76 and the throttle 52, different pressure conditions are achieved.

The dimensions of each throttle are selected as described below, and are set so that the valve member 70 will eventually move downward in the event of a collision at a collision speed v1 where the residual pressure is lower than P1.

Each of the through holes 51, 76, and 52 is usually selected to have a diameter of 1 to 2 degrees, but if the through hole 51 is too small, the transmission of the sudden pressure increase at the time of a collision to the valve member 70 will be delayed, resulting in a high P2. If this happens too much, a situation will occur in which the valve member 10 does not seal the vertically tilted surface after the collision.

If the through hole 76 is too large, the pressure in the lower chamber 58 will easily escape, making it difficult to obtain the force to move the valve member 16 completely upward, and P2 will become too high, resulting in the same undesirable result as described above.

Furthermore, as mentioned above, if the diameter of the lip 73 is too small, the valve member 70 will not be able to move when the residual pressure is higher than P1 at the collision speed v2, (3).
becomes unable to maintain its upward motion.

In actual cases, the upper chamber 57 has a space volume of 1 to 2 cc, but if this is too small, the upward movement of the valve member 70 at the time of a collision will be inhibited, and the P2 point will move in a higher direction.

Note that when the peak pressure at the time of collision is lower than P1, the valve member 70 maintains its initial state, so there is no fuel leakage and there is no problem.

On the other hand, if the motorcycle simply falls over and the tank does not deform, the tank is automatically sealed in this fallen position and left for a predetermined period of time.

The tank internal pressure increases with the passage of time, and increases with a gentle gradient as shown by the indicated line A in FIG.

When the tank internal pressure reaches the first set value P1 described above, the valve body γ2 moves upward, the lip 73 separates from the seat surface 56, the through hole 76 opens, the chambers 57 and 58 communicate, and the tank Internal pressure leaks to the outside air through the holes 51, 76, 52.

Therefore, the tank internal pressure is prevented from increasing as shown by the chain line extending from line A, and remains flat at the pressure of the first set value P1, so that the tank internal pressure does not increase to the extent that the tank outer plate is deformed.

In this case, if the through hole 51 is too thick, the resistance during passage of the fluid will be too small and the pressure in the lower chamber 58 will be high, causing the valve member 70 to completely move up and close again immediately after being lifted.

If the through holes 76 or 52 are too small, the fluid resistance will be too large to release the internal pressure of the tank, which increases due to sunlight energy, etc., and the tank may become deformed.

In addition, if the through hole 52 is too thick, if the liquid first flows out due to a fall and then changes to gas, the through hole 51
The resistance action of the through hole 52 when the valve member 70 is about to completely move upward due to a sudden decrease in resistance is too small.
This causes an inconvenience in that the tank is in an upward movement state and the inside of the tank is no longer communicated with outside air.

In FIG. 2, the fuel tank 13 is installed inside the cap 20 of the fuel tank 13, and the illustration shows the normal attitude.

In the illustrated state, the valve 65 moves downward, the through hole 64 opens, and the inside of the tank 13 includes the through holes 37 and 38, the clearance between the holder 61 and the guide 63, the clearance between the flange portion 67 of the valve 65 and the guide 63, the groove 66, and the through hole 64. It reaches the through hole 76 of the valve body 72 through the hole 64, communicates with the outside air through the upper chamber 57 and the through hole 52, and performs a breather action.

When the tank 13 falls due to a fall or the like, the ball 36 falls,
The valve 65 moves upward under the action of the tapered surface 35 and closes the passage 64 with its tip.

That is, by detecting the tilting, the breather passage system is closed and the tank is sealed.

When the tank internal pressure rises and exceeds the first set value, the valve body 72 moves upward in accordance with the above, and the outside air and the tank interior communicate through the through holes 51, 76, 52, thereby leaking the tank internal pressure.

The valve body 72 moves completely upward due to the rise in tank internal pressure at the time of a collision, and the seat surface 55 and the top surface of the body 72 come into close contact as described above.
The passage 51 system and the passage 64 system are completely cut off, the tank is cut off from the outside air, and the tank is sealed.

By the way, since FIG. 2 employs a bayonet type cap 20, the cap 20 is moved upward against the spring 34 as the internal pressure of the tank increases.

As a result, pressure acts on the seal member 80 through the clearance between the inner diameter portion 17 of the cap 16 and the cap body 23.

As the cap 20 moves upward, pressure acts on the space 88 facing the inner diameter of the sealing member 80, and as a result, the upper piece 81 and the lower piece 84
acts to open due to pressure, the upper piece 81 and the lower piece 84 stick to the cap flange portion 24 and the upper surface of the cap 16, and the clearance created by the upward movement of the cap 20 is closed.

That is, as the pressure increases, the sealing load increases, and is combined with the spring load to provide a strong sealing action and prevent fuel from being ejected from this portion even if the cap moves upward.

FIG. 6 is a graph showing the relationship between the sealing load of the sealing member and the tank internal pressure, with the horizontal axis representing the tank internal pressure (in weight) and the vertical axis representing the sealing load (kg).

As shown by the indicated line H, the sealing load on the conventional plate packing decreases from point L to point K, and further decreases to point M as the tank internal pressure increases.

In contrast, according to the sealing member 80 of the present invention, as shown by the indicator line ■, the sealing load increases from O to ■ as the tank internal pressure increases, and in order to obtain an even higher sealing load, the sealing load increases at point G. together with the load.

In the example shown above, the cap of the fuel tank has been shown as shown in FIG. 2, but this may be provided on the upper surface of the tank separately from the cap.

Alternatively, it may be provided between the tank and the fuel supply line via a pipe line.

[Brief explanation of drawings]

The drawings show one practical example of the present invention; FIG. 1 is a longitudinal sectional view showing the basic structure of a valve device, FIG. 2 is a longitudinal sectional view of an actual case in which the valve device is applied to a fuel tank cap, FIG. 3 is a vertical sectional view of only the cap seal member, FIG. 4 is a side view schematically showing the motorcycle, FIG. 5 is a graph explaining the operation of the valve device according to the present invention, and FIG. 6 is a diagram of the cap seal member. A graph explaining the action, Figure 7 is a graph explaining the relationship between the elapsed time when the tank is sealed and the internal pressure, Figure 8 is a graph explaining the relationship between the tank internal pressure and tank deformation, and Figure 9 is a graph at the time of collision. 2 is a graph illustrating the relationship between typical tank internal pressure and time. In the drawing, 13 is a fuel tank, 20 is a cap, 30.
36 is a tilt detection member, 40 is a valve device, 42 is a bottom member, 4
3 is an upper member, 51.52 is a communication hole, 64 is a breather hole,
65 is a breather hole opening/closing valve, 70 is a valve member, 73. 55
76 is an orifice of the valve member, and 80 is a seal member.

Claims (1)

[Scope of Claims] 1. A bottom member having a through hole that communicates with the inside of the tank, an upper member having a through hole that communicates with the outside air, and a bottom member that is formed between the bottom member and the upper member and that communicates with each of the through holes. A chamber is provided in which the interior of the tank is divided into upper and lower sections, and the inside of the tank and the outside air are normally blocked by pressure against the bottom member side, and the internal pressure of the tank is raised at the first setting value. a valve member with a through hole that is separated from the bottom member, communicates with each other, and closely contacts and shuts off the upper member side at a second set value exceeding the first set value; A valve device for a fuel tank for a vehicle, characterized in that the valve member, the bottom member, and the top member are provided with seal portions. 2. The valve device for a fuel tank for a vehicle according to claim 1, wherein the valve member with a through hole is a diaphragm with an orifice that partitions the chamber. 3. The valve device for a fuel tank according to claim 1, wherein the valve device is provided on the upper surface of the fuel tank. 4. A valve device for a vehicle fuel tank according to claims 1 and 2, wherein a breather hole of the fuel tank is provided in the bottom member, and a valve for opening and closing the breather hole is provided. 5. The valve device for a fuel tank for a vehicle according to claim 4, comprising an inclination detection means for operating the valve for the breather hole. 6. The valve device for a fuel tank for a vehicle according to claim 5, wherein the inclination detection means is constituted by a ball, and the valve for the breather hole is opened and closed by the movement of the ball. 7. The valve device for a fuel tank for a vehicle according to claim 1, wherein the valve device is incorporated in a cap that opens and closes a filler port of the fuel tank. 8. In claim 7, the cap includes an engaging member that comes into elastic contact with the lower surface of the fuel filler port, and the cap is provided with an engaging member that contacts the lower surface of the fuel filler port inwardly between the upper surface of the fuel filler port and the lower surface of the cap that is opposed to the lower surface of the cap. Valve system for a vehicle fuel tank with a seal member having a communicating space 9 In claim 8, the seal member has an outer diameter portion closed and an inner diameter portion communicated with the inside of the tank. A fuel tank valve device for a vehicle, which has a U-shaped cross section, has a plurality of spacers on opposing surfaces of overlapping upper and lower pieces, and is made of a ring-shaped flexible elastic body. 10. The vehicle fuel tank according to claim 2, wherein the through hole in the upper member is an orifice, and the space formed between the orifice and the orifice in the diaphragm has a certain volume. valve device.