JPH0891060A - Fuel tank - Google Patents

Abstract

PURPOSE: To provide a fuel tank which can suppress the production of the fuel vapor inside the tank and can prevent the vapor discharge during the oil feed, by a simple structure. CONSTITUTION: An oil feeding hole 4 and an oil discharge hole 5 are formed on a bag body 1 consisting of a soft thin film, and the bag body 1 is covered by an outer shell 2 having a ventilating hole 11. The bag body 1 is expanded by the charge with fuel, and when fuel reduces bag body 1 contracts by the reduction portion, and the production of vapor is suppressed. The thin film 3 of the bag body 1 is made of a lamination member which is formed by nipping a barrier layer with the oilproof rubber, and the fuel passing rate is reduced, and the fuel loss is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank used in a vehicle or the like, and more particularly to a structure of a tank having a function capable of arbitrarily changing the internal volume.

[0002]

2. Description of the Related Art A conventional fuel tank for a vehicle is entirely formed of a metal container. Liquid gasoline is filled in the tank, and refilling is repeated when the tank is empty. It is like this.

In such a fuel tank, the saturated vapor pressure of gasoline is considerably smaller than the atmospheric pressure,
As the volume of liquid gasoline decreases, gasoline vapor is generated and the empty tank is filled with gasoline vapor.

This gasoline vapor is discharged to the outside together with the air in the fuel tank during refueling, which causes a loss of petroleum resources and causes air pollution.

In response to the above problems, current automobiles have
Collect the vaporized gasoline vapor from the fuel tank,
It is equipped with a device called a canister that uses activated carbon, etc. to prevent it from being released into the atmosphere, but such a device does not have the function of preventing the emission of gasoline vapor from the refueling holes during refueling, and it is also used in vehicles. There is a problem that the manufacturing cost of the fuel tank increases due to the increase in the number of parts equipped.

Therefore, the present invention solves the above problems and devises the structure of the fuel tank itself,
It is an object of the present invention to provide a fuel tank which has a simple structure to suppress the generation of steam inside the tank and prevent the diffusion of steam into the atmosphere.

[0007]

In order to solve the above problems, the first means of the present invention is to provide a bag body formed of a flexible thin film with an oil supply hole and an oil discharge hole, and Outside,
It is a laminated material in which the bag surface is covered with an outer shell that limits the expansion amount under atmospheric pressure and the thin film is sandwiched with a nylon film or vinylidene chloride film with an oil resistant rubber.

On the other hand, according to the second means of the present invention, the opening of the container having the oil supply hole and the oil discharge hole is covered with a flexible thin film having substantially the same surface area as the inner surface of the container, and the outside of the thin film is covered. The thin film surface is covered with an outer shell that limits the amount of expansion under atmospheric pressure, and the thin film is a laminated material made of oil-resistant rubber or plastic, or both.

In each of the above means, the oil resistant rubber forming the thin film may be reinforced with synthetic fibers.

[0010]

In the first means, the fuel is injected into the bag body and filled up until the bag body is inflated. When the fuel is discharged from the bag body, the bag body shrinks by the discharged amount, and no gap is created between the bag body and the remaining fuel, so that generation of fuel vapor inside the bag body is prevented.

In the above structure, the thin film forming the bag is
By using the laminated material covered with the oil resistant rubber, adverse effects such as swelling of the bag due to the fuel are eliminated, and the bag can be stably inflated and shrunk without generating wrinkles or the like on the surface.

On the other hand, in the second means, fuel is injected between the inner surface of the container and the thin film to fill the thin film until it expands. When the fuel is discharged from the container, the thin film is deformed by the discharged amount, and since there is always no gap between the remaining fuel and the thin film, generation of fuel vapor is prevented.

In each of the above means, the fuel permeability of the laminated material forming the thin film is MIL-SPEC, MI.
0.025 oz / ft ^{2 as} defined by LT-6396
It is desirable to adjust the pressure to 24 H (7.85 gr / m ² · 24 H) or less, whereby the permeation of fuel can be substantially ignored, and stable fuel capacity retention can be performed.

[0014]

1 to 3 show a first embodiment of the present invention. The fuel tank of this embodiment comprises a bag body 1 forming a tank body, and an outer shell 2 covering the outside of the bag body 1.

The bag 1 is formed of a flexible thin film 3 which can be expanded and contracted, and has an oil supply hole 4 formed at the upper end and an oil discharge hole 5 formed at the lower end. The oil supply hole 4 and the oil discharge hole 5 are
It is inserted into the oil supply passage 6 and the drain oil passage 7 which are projected from the outer shell 2,
The ends of the oil supply / drain holes 4 and 5 are fixed to the openings of the passages 6 and 7, so that the bag body 1 is held by the outer shell 2.

The thin film 3 forming the bag 1 is shown in FIG.
As shown in (a), the barrier layer 8 made of a nylon film or a polyvinylidene chloride film has a laminated structure in which both sides are sandwiched by oil-resistant rubbers 9 and 9, and the fuel permeation rate of the film itself is MIL-. SPEC, MIL-T-6
It is adjusted to be 0.025 oz / ft ² · 24H or less according to the regulations of 396.

The oil resistant rubber layer 9 is used to improve the mechanical strength of the thin film 3 as shown in FIG. 2 (b).
It is desirable that the synthetic fiber 10 such as nylon woven fabric or polyester woven fabric be embedded and reinforced in the rubber, and the thickness is usually set to about 5 to 6 times the thickness of the barrier layer 8.

On the other hand, the outer shell 2 uses the thin film 3 as the expansion amount of the bag body 1.
The vent hole 11 is formed to have a size within a permissible amount determined by the mechanical strength and the like, and an air hole 11 for causing atmospheric pressure to act on the surface of the bag body 1 is formed above the bag.

As the material of the outer shell 2, a material having strength and rigidity necessary for fixing and holding the fuel tank at a predetermined position of a vehicle or the like is used. For example, metal or plastic material including fiber reinforced plastic is used. To be done.

Further, as shown in FIG. 3 (a), the method of fixing the oil supply passage 6 of the outer shell 2 and the oil supply hole 4 of the bag body 1 is such that the end of the oil supply hole 4 is opened by the opening of the oil supply passage 6. A method of folding back outward and crimping the folded portion 4a with the fixing ring 12,
As shown in FIG. 3 (b), an annular ring 13 made of metal, ultra-high molecular polyethylene, or the like is press-fitted into the inner surface of the oil supply hole 4, and the elasticity of the ring 13 causes the bag body 1 to move into the oil supply passage 6
There is a method of crimping to. The method of fixing the oil drainage passage 7 of the outer shell 2 and the oil drainage hole 5 of the bag body 1 can be performed in the same manner as described above.

The fuel tank of the embodiment has the structure as described above, and the fuel is supplied from the oil supply hole 4 of the bag body 1 to the liquid gasoline A.
1 is injected, and the filling of gasoline is completed when the bag body 1 expands to the inner surface of the outer shell 2 as shown in FIG.

When the liquid gasoline A is discharged from the inside of the bag 1 from this state, the saturated vapor pressure of the gasoline (temperature 3
Since 0.43 kgf / cm ² at 0 ° C. is smaller than the atmospheric pressure, the bag 1 is compressed by the atmospheric pressure acting on the surface of the bag 1 through the vent holes 11 of the outer shell 2, and the liquid gasoline A Shrinks by the volume discharged.

As a result, the inner surface of the bag body 1 is displaced in a state of being in close contact with the liquid surface of the liquid gasoline A, and there is no gap between them, so that the generation of gasoline vapor is prevented. Therefore, the gasoline refueled in the bag 1 can be used with high efficiency without loss, and the gas vapor can be suppressed from being diffused even if the refueling hole 4 is opened at the time of refueling.

4 to 6 show a second embodiment.

In this example, the tank main body for storing gasoline is formed from a hemispherical container 21 and a flexible thin film 22 that closes the opening of the container 21.
4 and the oil drain hole 25 are formed.

Further, the upper part of the container 21 is covered with a hemispherical outer shell 23 for limiting the expansion amount of the thin film 22. The outer shell 23 has a vent hole 26 in the upper portion, and as a whole, the container 21
It is formed to have a shape and dimensions that are similar to
As shown in FIG. 4, a spherical space is formed by combining the outer shell 23 and the container 21.

As shown in FIG. 5, the thin film 22 is formed by integrally molding an annular flange portion 28 on the outer circumference of a hemispherical portion 27, and the surface area of the hemispherical portion 27 is that of the container 21 and the outer shell 22. It is set to have almost the same size as the surface area of the inner surface.

As shown in FIG. 4, the thin film 22 has the flange portion 28 sandwiched by the flanges 29 and 30 formed on the outer peripheral portions of the container 21 and the outer shell 23, and the outer periphery of the flanges 29 and 30 is caulked. By caulking with the tool 31, the container 21 and the outer shell 2
It is fixed to 3. In this fixed state, the hemispherical portion 27 of the thin film 22 is deformed so as to be inverted with the brim portion 28 as a boundary, and when inverted downward, the hemispherical portion 27 is formed on the inner surface of the container 21.
When it is turned upside down, it follows the inner surface of the outer shell 23.

As a material for forming the thin film 22, a laminated material in which an oil resistant rubber layer and a plastic layer are laminated as shown in FIG. 6 is used. In the laminated material shown in FIG. 6 (a), oil-resistant rubber layers 32, 33 reinforced with nylon woven fabrics 32a, 33a are provided on the inner and outer layers, and a plurality of barrier layers 34, 34 made of nylon films are provided on the inside thereof. It has a structure in which is adhered and sandwiched, and the fuel permeation rate to gasoline is MIL-SPEC, MIL as the membrane itself.
-T-6396 regulates 0.025oz / ft ² ·
It is formed to be 24H or less.

The laminated material shown in FIG. 6 (b) has a single barrier layer 34 sandwiched between the oil resistant rubber layers 32 and 33.

In the structure shown in FIGS. 6 (a) and 6 (b), the barrier layer 34 may be made of vinylidene chloride film in addition to nylon film, such as Eval (trade name) manufactured by Kuraray Co., Ltd. You can also Further, nylon woven fabrics 32a, 33a for reinforcing the oil resistant rubber layers 32, 33
A polyester woven fabric such as Tetron (trade name), an aramid woven fabric, or the like can also be used for this.

FIG. 7 shows an example of another laminated material.
The laminated material of (a) has a barrier layer 34 made of a nylon film or a vinylidene chloride film and a metal foil layer 35 provided between the inner and outer oil-resistant rubber layers 32 and 33. In the example shown in FIG. 7B, the barrier layer made of a plastic material is omitted and only the metal foil layer 35 is sandwiched between the oil resistant rubber layers 32 and 33.

As described above, when one layer of the thin film laminated material is a metal foil layer, fuel permeation to the thin film can be surely blocked, the shape retention of the thin film is improved, and wrinkles are generated during expansion and contraction. It is possible to prevent abnormal deformation. In addition,
The thickness of the metal foil layer 35 is set to such an extent that the flexibility of deforming the thin film 22 is not lost.

On the other hand, as the material forming the container 21 and the outer shell 23, a material having strength and rigidity required for the fuel tank is used, and a thin metal plate having good moldability or a plastic material including fiber reinforced plastic is used. Used.

In the fuel tank of the embodiment having the above-mentioned structure, the thin film 22 is the container 21 as shown in FIG.
When the liquid gasoline A is injected from the oil filling hole 24 from the empty state which is adhered to the inner surface of the thin film 22, the thin film 22 is inverted and deformed at the flange portion 28, and as shown in FIG. When the inside of the thin film 22 adhered to the inner surface is filled with the liquid gasoline A, it becomes full.

When the liquid gasoline A is consumed from this state, the thin film 22 is deformed downward by the action of the atmospheric pressure, and finally, the thin film 22 is inverted at the brim portion 28 to be along the liquid surface of the gasoline. It deforms and does not create a gap with gasoline. Therefore, the generation of gasoline vapor inside the tank is suppressed, and the vapor is prevented from being dissipated during refueling.

FIGS. 8 and 9 show a third embodiment. In this embodiment, the container 21, the outer shell 23, and the thin film 22 in the second embodiment described above are formed in a rectangular box shape. .

Further, the brim portion 28 of the thin film 22 is attached to the bolt 3
It is fixed to the flanges 29 and 30 of the container 21 and the outer shell 23 by using 6.

Since the other structure is the same as that of the second embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

In each of the above embodiments, the outer shells 2, 23
Has a container shape in which all sides are closed. However, if the outer shell has a function of limiting the expansion amount of the bag 1 or the thin film 22 as long as atmospheric pressure can be applied to the surface, It does not require high strength, and can be formed in a mesh shape or a frame shape.

In the above description, a fuel tank for gasoline has been described as an example, but the fuel is not limited to gasoline, and the same applies to light oil and other fuels that easily generate saturated vapor. it can.

Further, the present invention can be applied not only to a fuel tank mounted on a vehicle but also to a storage tank for kerosene or the like having a capacity of several hundred liters.

[0043]

As described above, according to the present invention, the capacity of the tank is made variable according to the amount of fuel by using the flexible bag and the thin film, and the bag and the thin film are made of a material having a small fuel permeability. It is possible to prevent generation of fuel vapor inside the tank, reduce fuel loss, and prevent air pollution due to vapor diffusion.

Further, the structure is simple in that only a bag or a thin film is incorporated into the fuel tank, and a gas collecting device such as a canister can be dispensed with, so that a fuel tank having a variable capacity function can be manufactured at low cost. There is.

[Brief description of drawings]

FIG. 1A is a sectional view showing a first embodiment, and FIG. 1B is a sectional view showing its operating state.

FIG. 2A is a cross-sectional view showing a laminated structure of thin films of a bag,
(B) is a cross-sectional view showing another laminated structure

3 (a) and 3 (b) are cross-sectional views showing a method of fixing an oil supply hole and an oil supply passage, respectively.

FIG. 4A is a sectional view showing a second embodiment, and FIG. 4B is a sectional view showing its operating state.

FIG. 5 is a perspective view showing the same thin film.

6A and 6B are cross-sectional views each schematically showing a laminated structure of thin films.

7A and 7B are cross-sectional views schematically showing other laminated structures of thin films.

8A is a sectional view showing a third embodiment, and FIG. 8B is a sectional view showing its operating state.

FIG. 9 is a perspective view showing the same thin film.

[Explanation of symbols]

 1 bag 2 outer shell 3 thin film 4 oil supply hole 5 oil discharge hole 8 barrier layer 9 oil resistant rubber layer 10 synthetic fiber 11 vent hole 21 container 22 thin film 23 outer shell 24 oil supply hole 25 oil discharge hole 26 air vent 31 caulking tool 32 , 33 Oil resistant rubber layer 34 Barrier layer 35 Metal foil layer A Liquid gasoline

Claims (3)

[Claims] 1. A bag body formed of a flexible thin film is provided with an oil supply hole and an oil discharge hole, and the expansion amount of the outside of the bag body is limited in a state where atmospheric pressure is applied to the surface of the bag body. A fuel tank in which the thin film is covered with an outer shell, and the thin film is a laminated material in which a nylon film or a vinylidene chloride film is sandwiched with an oil resistant rubber. 2. An opening of a container having an oil supply hole and an oil discharge hole is covered with a flexible thin film having substantially the same surface area as the inner surface of the container, and the outside of the thin film is exposed to atmospheric pressure on the thin film surface. A fuel tank in which the thin film is covered with an outer shell that limits the expansion amount in the above state, and the thin film is a laminated material made of oil-resistant rubber or plastic or both. 3. A fuel tank in which the oil-resistant rubber forming the thin film of the fuel tank according to claim 1 or 2 is reinforced with synthetic fibers.