JP3434201B2 - 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 fuel tank for storing fuel, and more particularly to a fuel tank for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in a fuel tank of an internal combustion engine, the evaporated fuel of the stored fuel is temporarily adsorbed in a charcoal canister, and the negative pressure of the intake pipe is utilized during operation of the internal combustion engine to transfer the evaporated fuel to the intake pipe. There is known a technique of introducing the same into a combustion chamber and burning it in a combustion chamber for processing. It is known that a large amount of vaporized fuel is generated when the temperature of the fuel in the fuel tank rises, a large amount of gas space exists in the tank, or highly volatile fuel is stored. Therefore, depending on the temperature in the fuel tank and the volume of the gas space in the fuel tank, a large amount of evaporated fuel may be generated and may not be processed by the evaporated fuel processing device such as a charcoal canister and may be released to the atmosphere.

Therefore, in order to suppress the generation of evaporated fuel in the fuel tank itself, a technique for reducing the volume of the gas space in the fuel tank is disclosed in, for example, US Pat. No. 361703.
No. 4 or Japanese Patent Laid-Open No. 56-128221. In the fuel tanks disclosed in these documents, a membrane wall (separating member) for separating the fuel chamber and the air chamber in the tank is provided in an outer shell tank having a constant volume. Due to the expansion and contraction, the membrane wall is always in close contact with the fuel liquid surface, and the volume of the gas space above the fuel liquid surface is reduced. As a result, generation of evaporated fuel is suppressed.

[0004]

By the way, generally, a fuel injection pipe for supplying fuel to the fuel chamber, a vapor passage for guiding evaporated fuel in the fuel chamber to the canister, and a property of injecting fuel into the fuel chamber are provided. Various passages such as a breather line for improvement are connected. When these various passages are connected to the stretchable and deformable membrane wall described above, when the amount of fuel decreases, the openings of the various passages having higher rigidity than the membrane wall come into contact with the inner wall of the membrane wall. When the movement of the fuel (fuel sway) and the deformation of the membrane wall due to fuel consumption progress in the contact state,
There is a possibility that expansion and contraction deformation of the membrane wall may be hindered, or the inner wall of the membrane wall may deteriorate due to sliding or tear.

The various passages are fixed to the membrane wall via a metal or resinous fixing plate. If the fixing strength of this fixing plate is large or the rigidity of the fixing plate itself is large, the membrane wall is fixed. There is a risk that expansion and contraction may be hindered or that the membrane wall may be fatigue-damaged due to a rapid change in rigidity between the end of the fixed plate and the membrane wall.

The present invention has been made in view of the above problems, and suppresses the inhibition of expansion and contraction deformation of the membrane wall by the fixing member at the openings of various passages connected to the membrane wall or the connection portions of various passages. And to suppress damage to the inner wall of the membrane wall.

[0007]

The present invention adopts the following constitution in order to solve the above problems. That is,
In the fuel tank of the first invention of the present case, a membrane wall for separating the fuel chamber and the air chamber is provided in the outer shell structure of the fuel tank, and the membrane wall is deformed according to the amount of fuel in the fuel chamber. In a fuel tank in which the volume of the fuel chamber changes, a passage connecting the fuel chamber and the outside is provided at a position facing the moving direction of the opening of the passage, and the opening of the passage is formed when the amount of stored fuel decreases. And an opening holding means for holding.

In the fuel tank, a film wall for separating the fuel chamber and the air chamber is provided in the outer shell structure, and the film forming the fuel chamber according to the remaining amount of fuel as fuel is supplied and consumed. The wall deforms and the volume of the fuel chamber changes. In this fuel tank, fuel, evaporated fuel, and air are taken in and out of the tank via various passages connected to the fuel chamber. When the fuel in the fuel chamber decreases, the positions of the openings of the various passages connected to the fuel chamber also move. Although the moving direction of the opening is determined by the direction of deformation of the membrane wall, the opening of the passage generally moves so that the membrane wall approaches the inner wall of the fuel chamber facing the opening as the membrane wall deforms.
The opening close to the inner wall is held so as not to slide on the inner wall by the holding means provided at the opposite position in the moving direction, so that damage to the inner wall is suppressed. Moreover, since the opening is held at a fixed position, the degree of freedom of deformation in the other part of the membrane wall is secured.

Examples of the passage of the present invention include a fuel injection passage for introducing fuel into the fuel chamber, a vapor passage for discharging evaporated fuel in the fuel chamber, or a fuel passage for delivering fuel in the fuel chamber to a fuel pump.

Further, as a specific example of the holding means, there are openings of a plurality of passages connected to face each other in the fuel chamber. These openings hold each other when the fuel is low, so that the openings are prevented from sliding on the inner wall of the fuel chamber. Further, since the opening itself is the holding means, the structure of the tank can be simplified.

In the fuel tank of the second invention of the present application, a membrane wall for separating the fuel chamber and the air chamber is provided in the outer shell structure of the fuel tank, and the membrane wall is formed in accordance with the amount of fuel in the fuel chamber. In a fuel tank where the wall deforms and the volume of the fuel chamber changes,
A passage connected to the fuel chamber, and a fixing member for connecting and fixing the opening of the passage to the membrane wall of the fuel chamber and weakening the fixing strength of the opening relative to the membrane wall as the distance from the opening increases. It is characterized by including.

The above fuel tank is provided with a membrane wall for separating the fuel chamber and the air chamber in the outer shell structure of the fuel tank, and the membrane wall is formed according to the remaining fuel amount as fuel is supplied and consumed. It deforms and the volume of the fuel chamber changes. Further, this fuel tank takes in and out fuel, evaporated fuel, and air from the outside of the tank through various passages connected to the fuel chamber. This passage is connected and fixed to the fuel chamber using a fixing member. In the present invention, the fixing strength of the fixing member is increased near the opening, and the fixing strength is weakened as the distance from the center of the opening increases.

As a result, the strength of the connection between the membrane wall and the passage is secured on the center side of the opening, and the deformation of the membrane wall is not hindered at the position away from the opening. Further, since the fixing strength (rigidity) does not change abruptly at the end portion of the fixing member, fatigue failure of the film wall is suppressed. It should be noted that the farthest end of the fixing member may be set to a fixing strength close to the rigidity of the membrane wall.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a fuel tank according to the present invention will be described below with reference to the drawings. FIG. 1 is a first embodiment and is a schematic configuration diagram showing a configuration when a fuel tank according to the present invention is applied to a fuel tank of an internal combustion engine for a vehicle.

The fuel tank body is roughly classified into an outer shell container 1
And a fuel container 4 as a fuel chamber for storing fuel. The outer shell container is composed of an upper portion 2 and a lower portion 3 made of, for example, a metal material or a synthetic resin material, and these flange portions 2a, 3a are airtightly connected to each other. In addition, a fuel container 4 is provided in the outer shell container 1.
The fuel container 4 has a function as a membrane wall that separates the inner space of the outer shell container 1 into the fuel chamber 5 and the air chamber 6. The shape (volume) of the fuel container 4 changes according to the remaining amount of fuel so that the evaporated fuel and air generated above the liquid surface of the fuel are discharged to the outside and constantly filled with the fuel.

As shown in the perspective view of FIG. 2A and the side view of FIG. 2B, the fuel container 4 has the same rigidity as the upper membrane wall 4a of a rectangular shape which is rigid but is deformable, but is deformed. With a possible rectangular lower membrane wall 4b. The edges of the upper membrane wall 4a are connected to the corresponding edges of the lower membrane wall 4b via the side surface membrane wall 4c. The side membrane wall 4c is a rectangular strip-shaped member that has rigidity but is deformable. Therefore, the fuel container 4 has a substantially flat rectangular parallelepiped shape in which the strip-shaped side wall 4c is closed by the upper membrane wall 4a and the lower membrane wall 4b.

When fuel is supplied to the fuel container 4, for example, from the state shown in the side view of FIG. 2B, the side membrane wall 4c is used as a reference position for deformation as shown in the side view of FIG. 2C. ,
The upper membrane wall 4a and the lower membrane wall 4b are deformed so as to extend to fill the inside of the fuel container with fuel. On the other hand, when the amount of fuel decreases, the upper membrane wall 4a and the lower membrane wall 4b are deformed so as to contract, and the fuel container 4 is filled with the fuel. When the fuel container 4 is deformed, in order to prevent air layers such as evaporated fuel and air from remaining in the fuel container, the evaporated fuel and air are discharged to the outside of the fuel container through a vapor passage described later. , The fuel container is always kept liquid-tight.

Further, as shown in FIG. 3, the upper membrane wall 4a,
The lower membrane wall 4b and the side membrane wall 4c are the core portion 100.
It has a five-layer structure in which the skin portions 102 are adhered to both sides of the sheet via adhesives 104. The core portion 100 is made of a copolymer resin of ethylene and vinyl or nylon, and the skin portion 102 is made of high density polyethylene. Further, the rigidity per unit area of the side wall 4c of the present embodiment is higher than the rigidity per unit area of the upper film wall 4a and the lower film wall 4b.

Returning to FIG. 1, the fuel container 4 is fixed to the outer shell container 1 by a fixing member 7 at the center of the lower surface of the fuel container. The fixing member 7 is composed of a cylinder and a piston, and the movement of the piston is allowed so that the lower surface of the fuel container 4 can be deformed in the vertical direction. When the fuel tank of the present embodiment is a vehicle fuel tank, this piston has a function of mitigating vibration transmitted from the outer shell container 1 to the fuel container 4.

An air chamber 6 is formed in the space between the outer shell container 1 and the fuel container 4. The air chamber 6 is set to a pressure slightly higher than the atmospheric pressure outside the fuel tank by a pressure regulating valve 8 provided in the upper portion of the outer shell container 1. As a result, when the fuel in the fuel container is consumed, the pressure of the air chamber 6 causes the fuel container 4 to be deformed to a size corresponding to the amount of fuel. Further, at the time of fuel refueling, the pressure of the air chamber 6 is released to the atmosphere by the pressure regulating valve 8, so that the fuel refueling pressure causes the fuel container 4 to be largely deformed to a size corresponding to the fuel amount. Further, the air chamber 6 is provided with a fuel gauge 9 that detects the position or movement amount of the fuel container 4 at the center of the upper surface and calculates the amount of fuel in the fuel container. The fuel gauge 9 is a pendulum type gauge, and calculates the fuel amount from the displacement angle of the pendulum.

As shown in FIG. 1, a fuel common pipe 10 is airtightly connected to the center of the lower surface of the fuel container 4 via a fixing plate 12 made of a metal material or a synthetic resin material. The other end is connected to the fuel injection pipe 14. A fuel cap 16 is detachably attached to the upper end opening 14 a of the fuel injection pipe 14. Inside the fuel injection pipe adjacent to the upper end opening 14a, a seal member 18 is arranged which comes into contact with the outer peripheral surface of the fuel injection nozzle inserted into the fuel injection pipe 14 during refueling. On the other hand, a check valve 20 is provided at the lower end opening 14b of the fuel injection pipe connected to the common fuel pipe 10, and the check valve 20 is opened by the pressure of the flow of fuel during fueling. In the normal state, the valve is closed when the fuel moves toward the fuel injection pipe 14. The fuel common pipe 10 has a function of supplying the fuel from the fuel injection pipe 14 into the fuel container at the time of refueling, and delivering the fuel to the fuel pump chamber 22 from the inside of the fuel container at normal times. A part of the fuel common pipe close to the connection with the fuel container is formed of a flexible pipe whose conduit can be expanded and contracted so as to follow the deformation of the fuel container 4.

A fuel pump chamber 2 is provided at the other end of the fuel common pipe 10.
2 is connected. Fuel pump 2 in the fuel pump chamber
4, a fuel pressure regulator 26, and a fuel filter 28 are arranged. The fuel in the fuel container is introduced into the fuel pump chamber 22 via the fuel common pipe 10, the fuel discharged from the fuel pump 24 is regulated by the fuel pressure regulator 26, and the fuel in the internal combustion engine 50 is regulated via the fuel supply pipe 30. It is supplied to a fuel injection valve (not shown). The upper portion of the fuel pump chamber 22 is connected to the vicinity of the upper end opening of the fuel injection pipe 14 via the first vapor passage 32. The first vapor passage 32 has a function of sending the evaporated fuel in the fuel pump chamber 22 to the outside of the pump chamber, and also allows the gas in the space above the liquid surface of the pump chamber whose volume gradually decreases when refueling to open the upper end of the fuel injection pipe 14. Part 14
By opening to a, it functions as a breather passage for ensuring oil supply. The connection position between the fuel pump chamber 22 and the fuel common pipe 10 is lower than the connection position between the fuel container 4 and the fuel common pipe 10. As a result, even if the fuel in the fuel container becomes extremely small,
Can be collected in. That is, the fuel pump chamber 22 has a function as a sub tank capable of temporarily storing fuel.

First of the upper end opening 14a of the fuel injection pipe 14
In the vicinity of the vapor passage 32, a second vapor passage 34 for sending the evaporated fuel in the fuel injection pipe to the outside of the fuel tank is connected. The other end of the second vapor passage 34 is connected to the charcoal canister 36. The charcoal canister 36 includes an adsorbent 38 made of activated carbon, an atmosphere passage 40 connected to an air cleaner 52 of the internal combustion engine, and an internal combustion engine 50.
The purge passage 42 is connected to the intake passage 54 downstream of the throttle valve 56. An atmosphere control valve 44 and a purge control valve 46 are provided in the atmosphere passage 40 and the purge passage 42, respectively.
Are provided, and the opening degree of each control valve is controlled by an electronic control unit (ECU) 58. In addition, the ECU 58
Is an intake air amount sensor 60 provided in an intake pipe 54 of the internal combustion engine, a rotation speed sensor 62 of the internal combustion engine, a cooling water temperature sensor 6
4 and the like to detect various operating states and control the injection amount of a fuel injection valve of an internal combustion engine (not shown).

The atmosphere control valve 44 is normally opened to the atmosphere, and the evaporated fuel in the fuel injection pipe is temporarily adsorbed by the charcoal canister 36 via the second vapor passage 34. The evaporated fuel adsorbed by the charcoal canister 36 is introduced into the intake pipe 54 by controlling the purge control valve 46 during the operation of the internal combustion engine, and burned by the internal combustion engine 50.

On the other hand, a third vapor passage 72 is connected to the center of the upper surface of the fuel container 4 via a fuel cutoff valve 70.
The other end of the third vapor passage 72 is connected to the upper end opening 14 a of the fuel injection pipe 14. A part of the third purge passage 72 disposed in the air chamber 6 is configured to be expandable and contractable so as to follow the deformation of the fuel container 4. The fuel cutoff valve 70 is hermetically connected to the upper space of the fuel container 4 via a fixed plate 74 formed of a metal material or a synthetic resin material. In the present embodiment, a part of the fuel cutoff valve 70 is provided so as to project into the fuel container 4. The fuel cutoff valve 70 has a float inside, and when vaporized fuel or air exists in the upper space above the fuel level in the fuel container, the float descends to allow communication with the third vapor passage 72 and When there is no space and the inside of the fuel container is liquid-tight, the float rises and blocks communication with the third vapor passage 72.

In this embodiment, the third embodiment including the fuel cutoff valve 70
The opening 71 of the vapor passage is connected to the central portion of the upper surface of the fuel container as described above, but the opening 71 of the third vapor passage 72 is formed at the center of the lower surface of the fuel container as shown in FIG. 4A. It is arranged so as to face the opening 11 of the fuel common pipe 10 connected to. That is, the third vapor passage 72
When the amount of fuel in the fuel container is reduced, the opening 71 moves in the downward direction of the fuel container 4 (the direction of the arrow in FIG. 4A). The opening 11 of the fuel common pipe 10 is arranged in this moving direction.

Next, the operation of this embodiment will be described. At the time of refueling the fuel, the fuel is supplied to the fuel injection pipe 14, and the check valve 20 is opened at the refueling pressure. Then, the fuel enters the fuel container through the fuel common pipe 10 through the opening 11. At this time, since the air chamber 6 of the outer shell container 1 is opened to the atmosphere by the pressure regulating valve 8, the fuel container 4 expands and deforms due to the refueling pressure. Further, the evaporated fuel and the air temporarily generated in the upper portion of the fuel container 4 pass from the fuel cutoff valve 70 to the third vapor passage 72.
Is discharged to. Then, the evaporated fuel and air are delivered to the charcoal canister 36 via the fuel injection pipe 14 and the second vapor passage 34. When all the evaporated fuel and air are discharged from the upper portion of the fuel container, the inside of the fuel container becomes liquid-tight and the fuel cutoff valve 70 is closed.

On the other hand, when the fuel is consumed, the fuel is delivered from the lower surface of the fuel container to the fuel pump chamber 22 through the fuel common pipe 10, and is delivered by the fuel pump 24 to a fuel injection valve (not shown). At this time, the air chamber 6 is regulated to a pressure slightly higher than the atmospheric pressure by the pressure regulating valve 8.
When the fuel is consumed as shown in (a), the fuel container 4 is pressed from the air chamber 6 and contracts and deforms so that the inside of the fuel container is always liquid-tight.

When the amount of fuel becomes small, as shown in FIG. 4 (b), the protrusion of the opening 71 of the third vapor passage 72 causes the opening 11 of the common fuel pipe 10 connected to the lower surface of the fuel container 4. It gets in and is held. As a result, the opening 71 of the third vapor passage 72 is restricted from moving in the horizontal direction in the fuel container 4, so that sliding on the inner wall of the fuel container 4 is suppressed. Furthermore, since the opening 71 is held at a fixed position, the other portions of the fuel container 4 can be deformed as prescribed in accordance with the decrease in fuel.

Next, a second embodiment of the present invention will be described with reference to FIG. The description of the components having the same numbers as in the first embodiment will be omitted. FIG. 5 shows the fuel container 4 and the fuel cutoff valve 7.
It is an enlarged view of the principal part which shows the connection of the 3rd vapor passage 72 containing 0. The holding means in the second embodiment is shown in FIG.
As shown in (a), it is a holding member 80 provided on the inner wall of the fuel container 4 and containing a magnetic material. The holding member 80 is provided on the inner wall of the fuel container facing the moving direction of the opening 71 of the third vapor passage 72 including the fuel cutoff valve 70.
The base material of the holding member 80 is made of the same rigidity and the same material as the inner wall of the fuel container 4, and the base material contains a magnetic material. The magnetic force of the magnetic material has such a magnetic force that the opening 71 is separated from the holding member 80 if the refueling pressure is equal to or higher than the refueling pressure at the time of refueling the fuel.

The fuel cutoff valve 70 and the third vapor passage 7 are also provided.
When the second opening 71 is made of a non-metallic material, a metal material or a magnetic material may be added to the opening side. A magnetic material may be added to the opening 11 of the fuel common pipe 10 described in the first embodiment instead of the holding member shown in FIG.

Next, the operation of the second embodiment will be described. Here, only the operation different from that of the first embodiment will be described. When the fuel is supplied and the inside of the fuel container is made liquid-tight by the fuel, as shown in FIG.
As shown in (a), the fuel cutoff valve 70 is connected to the third vapor passage 7
Cut off 2. Next, when the fuel is consumed, the fuel container 4 contracts and deforms, and the opening 71 of the third vapor passage 72 is formed.
Move toward the lower surface of the fuel container 4. When the amount of fuel becomes small, the opening 71 of the third vapor passage 72 is pulled by the magnetic force of the holding member 80 as shown in FIG.
At 0, motion is retained. As a result, the third vapor passage 72
Since the movement of the opening 71 of the is restricted in the fuel container,
Sliding on the inner wall of the fuel container 4 is suppressed. Furthermore, since the opening 71 is held at a fixed position, the other portions of the fuel container 4 can be deformed as prescribed in accordance with the decrease in fuel. When the opening 71 of the third vapor passage 72 or the fuel cutoff valve 70 is held by the holding member 80, the inner wall and the fuel cutoff valve 70 are secured so that communication between the fuel cutoff valve 70 and the fuel chamber 5 is ensured. A gap may be provided between the two.

Next, the second aspect of the present invention will be described with reference to FIGS. 1 and 6 to 9. The description of the components having the same numbers as in the first embodiment will be omitted. As described above with reference to FIG. 1, the fuel common pipe 10 and the third vapor passage 72 are connected to the fuel container 4 via the fixing plates 12 and 74 formed of, for example, a metal material or a synthetic resin material. The fixed plates 12 and 74 are made larger than the rigidity of the fuel container 4 in order to secure the connection rigidity at the connection portion or to disperse the stress in the vicinity of the connection portion of the passage. Further, the fixing plates 12 and 74 are preferably the fuel container 4
By using the same material as or the similar material that can be welded to the fuel container 4 (for example, a nylon multilayer material), the manufacturing of the fuel container can be simplified.

FIG. 6 shows the connection between the fuel common pipe 10 and the fuel container 4, and is a plan view seen from the lower surface of the fuel container.
The fuel common pipe 10 is arranged along the lower surface of the fuel container, and is connected to the center of the fuel container 4 via a fixed plate 12 having a circular shape in plan view. By making the fixing plate 12 circular, the stress concentrated on the connecting portion can be evenly dispersed.

FIG. 7 shows a third embodiment of the present invention, and is an enlarged side sectional view of a connecting portion between the fuel container 4 and the fuel common pipe 10. A fuel common pipe 10 is connected to the center of the lower surface of the fuel container 4 via a fixed plate 12a. In this embodiment, the thickness of the fixing plate 12a is changed stepwise so that the thickness of the fixed plate 12a is thicker toward the center line and thinner toward the outer peripheral portion of the tank with the center line of the opening 11 of the fuel common pipe 10 as a reference. The shape.

By changing the thickness of the fixing plate 12a in this manner, the connecting rigidity of the common fuel pipe is secured on the center line side, and the rigidity is reduced at the peripheral portion of the fixing plate 12a far from the center line to reduce the fuel consumption. The rigidity of the container 4 can be approximated to suppress the inhibition of the deformation of the fuel container 4. Further, in the peripheral portion of the fixed plate 12a, the rigidity gradually changes between the fuel container 4 and the fixed plate 12a,
Fatigue failure of the fuel container due to stress concentration is suppressed.

FIG. 8 is a diagram corresponding to the fourth embodiment. The difference from the above-described third embodiment is that the thickness of the fixing plate is not stepwise but smoothly changed. The operation and effect of this embodiment are similar to those of the above-described third embodiment, but the deformation of the fuel container becomes smoother than that of the third embodiment.

FIG. 9 is a diagram corresponding to the fifth embodiment. The difference from the third embodiment described above is that the thickness of the fixed plate is not changed, but a groove (deformed bead) for adjusting the amount of deformation is formed in the fixed plate itself. A deforming bead 13 is provided on the fixed plate 12c. In this modified bead 13, the size of the groove, the interval between the grooves, and the number of grooves are set according to the amount of deformation of the fuel container 4. That is, the size of the groove is reduced toward the center line of the opening 11 and increased toward the outer circumference of the tank. Alternatively, the gap between the grooves is widened toward the center line side and narrowed toward the outer peripheral side of the tank. Also, the number of grooves is reduced toward the center line,
Increase on the outer side of the tank. In addition to this, the above combination can be appropriately adjusted.

The operation and effect of this embodiment are the same as those of the above-mentioned third embodiment, and therefore their explanations are omitted. Although the groove is adjusted in the above embodiment, the material composition of the fixed plate may be changed to adjust the rigidity of the center line side of the opening and the outer peripheral side of the tank. Further, in addition to the opening 11 of the fuel common pipe 10, it can be applied to a passage connecting portion such as the opening 71 of the third vapor passage 72.

The various passages connected to the fuel container as the fuel chamber have been described above, but the passages are not limited to the above embodiment. As the passage, in addition to the fuel common pipe and the vapor passage, a pump passage for directly supplying fuel to the pump,
It may be a dedicated passage for supplying evaporated fuel or fuel directly to the internal combustion engine. In addition to the above, the holding means may have a structure in which the opening is hooked or a structure in which friction is applied to restrict the movement.

The entire fuel container as the fuel chamber does not have to be expandable and contractible. For example, it can be applied to a fuel tank that separates an air chamber and a fuel chamber by providing a separation member that can be expanded and contracted and deformed in a portion in contact with the fuel liquid surface. In addition to this, a bag-shaped expandable / deformable separation member is provided in the air chamber, and the volume of the air chamber is deformed according to the remaining amount of fuel, so that it can be applied to a fuel tank that substantially changes the volume of the fuel chamber.

[0042]

According to the first aspect of the present invention, there is provided a fuel tank comprising a membrane wall forming a fuel chamber, the membrane wall being deformable according to the amount of fuel in the fuel chamber. Since the opening of the passage connected to the chamber is held at a position opposed to the moving direction, the opening is prevented from sliding while abutting in the fuel chamber when the amount of fuel is small. As a result, deterioration of the membrane wall is suppressed. Further, since the opening is held, the deformation of the membrane wall is not hindered.

Further, according to the fuel tank of the second aspect of the present invention, the fuel tank is provided with a membrane wall forming a fuel chamber, and the membrane wall is deformable according to the amount of fuel in the fuel chamber. Since the opening of the passage connected to the chamber is fixed to the membrane wall and the fixing strength of the opening to the membrane wall is set to be smaller as the distance from the opening becomes smaller, stress concentration on the opening is relaxed. Moreover, since the strength gradually decreases, the deformation of the membrane wall is not hindered.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a first embodiment of a fuel tank according to the present invention.

FIG. 2 is a diagram showing the overall structure of a fuel container.

FIG. 3 is a material cross-sectional view illustrating a material composition of a fuel container.

FIG. 4 is a diagram for explaining the operation of the first embodiment.

FIG. 5 is a view for explaining the structure and operation of the second embodiment of the fuel tank according to the present invention.

FIG. 6 is a view for explaining the structure of the fuel container as viewed from below.

FIG. 7 is a view for explaining the structure of a third embodiment of the fuel tank according to the present invention.

FIG. 8 is a view for explaining the structure of the fourth embodiment of the fuel tank according to the present invention.

FIG. 9 is a diagram illustrating the structure of a fifth embodiment of the fuel tank according to the present invention.

[Explanation of symbols]

1 ... Outer shell container 2 ... Upper part 3 ... Lower part 4 ... Fuel container 5 ... Fuel chamber 8 ... Regulator valve 9 ... Fuel gauge 10 ... Common fuel pipe 11 ... Opening 12 ... Fixing plate 14 ... Fuel injection pipe 22 ... Fuel pump room 32 ... First vapor passage 34 ... Second vapor passage 36 ... Charcoal canister 40 ... Atmosphere 42 ... Purge passage 44 ... Atmosphere control valve 46..Purge control valve 58 ... ECU 70 ··· Fuel cutoff valve 71 ... Opening 72 ... Third vapor passage

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takuya Ishikawa, 26-26, Konosu-cho, Toyota-shi, Aichi Hori E Metal Industry Co., Ltd. Metal Industry Co., Ltd. (56) Reference Japanese Unexamined Patent Publication No. 56-128221 (JP, A) Actual development 51-85116 (JP, U) Actual development 52-53222 (JP, U) (58) Fields investigated ( Int.Cl. ⁷ , DB name) B60K 15/00-15/077 F02M 37/00

Claims (4)

(57) [Claims] 1. A fuel chamber forming a fuel chamber and an amount of fuel in the fuel chamber
A membrane wall that is deformable in accordance with the above, and a passage connected to the membrane wall
And an opening for opening the passage to the fuel chamber,
For the passage to move according to the change in the amount of fuel in the fuel chamber
In a fuel tank in which the opening of the passage also moves, an opening provided at a position facing the moving direction of the opening of the passage and holding the opening of the passage when the amount of fuel in the fuel chamber decreases. A fuel tank comprising: a part holding means. 2. The passage is at least one of a fuel injection passage for introducing fuel into the fuel chamber, a vapor passage for discharging evaporated fuel in the fuel chamber, and a fuel passage for delivering fuel in the fuel chamber to a fuel pump. The fuel tank according to claim 1, wherein: 3. The fuel according to claim 1, wherein a plurality of passages are connected to the fuel chamber, and the holding means is an opening of the passage arranged so as to face each other in the fuel chamber. tank. 4. A fuel tank comprising a partition forming a fuel chamber, the membrane wall of which is deformable according to the amount of fuel in the fuel chamber, and a passage connected to the fuel chamber and an opening of the passage. And a fixing member for fixing the strength of the opening to the membrane wall of the fuel chamber and weakening the strength of fixing the opening to the membrane wall as the distance from the opening increases.