JP2003286917A - Fuel storing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely eliminate space above a liquid level of fuel in a fuel storing device. <P>SOLUTION: The fuel storing device comprises: a film wall 5 forming a fuel chamber 7 and can be deformed depending on fuel amounts in the fuel chamber; a communicating port opened to the space above the liquid level of the fuel in the fuel chamber; cutoff valves 30, 31 opened to open the communicating port when the volume of the space above the liquid level of the fuel is larger than a predetermined volume, and closed to close the communicating port when the volume of the space above the liquid level of the fuel is smaller than the predetermined volume. When the volume of the space above the liquid level of the fuel is larger than the predetermined volume and the cutoff valve is opened, gas in the space above the liquid level of the fuel is discharged from above the liquid level of the fuel by using a means other than oil supply to the fuel chamber, and thereby the volume of the space above the liquid level of the fuel is reduced. When the volume of the space above the liquid level of the fuel is smaller than the predetermined volume, the cutoff valve is opened to stop the discharge of the gas from above the liquid level of the fuel through the communicating port. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fuel storage device.

[0002]

BACKGROUND OF THE INVENTION Fuel storage device (ie, fuel tank)
Needs to be exposed to the atmosphere so that the liquid surface of the fuel can move up and down. However, since the evaporated fuel is generated in the fuel tank, there is a problem that the evaporated fuel is released to the atmosphere. Therefore, it is known to open the fuel tank to the atmosphere via a canister equipped with activated carbon for temporarily adsorbing the evaporated fuel. However, if a large amount of fuel vapor is generated in the fuel tank, the canister itself must be made large. Therefore, in Patent Document 1, an expandable and retractable airbag is arranged in the fuel tank, and the airbag is expanded and contracted according to the vertical movement of the fuel liquid level so that a space is not formed above the fuel liquid level in the fuel tank. I have to.

[0003]

[Patent Document 1] JP-A-64-16426

[Patent Document 2] Japanese Patent Laid-Open No. 2-176200

[Patent Document 3] US Pat. No. 3,617,034

[Patent Document 4] Japanese Patent Laid-Open No. 8-197969

[Patent Document 5] JP-A-8-170568

[0004]

However, in the fuel tank disclosed in Japanese Patent Laid-Open No. 64-16426, the air bag is expanded and contracted without releasing the inside of the fuel tank to the atmosphere. This space cannot be excluded when there is already a space above it. Therefore, there is a problem that evaporated fuel is generated in the fuel tank. Therefore, an object of the present invention is to reliably exclude the space above the liquid surface of the fuel in the fuel storage device.

[0005]

In order to solve the above problems, in the first aspect of the present invention, a membrane wall that forms a fuel chamber and is deformable according to the amount of fuel in the fuel chamber, and the fuel in the fuel chamber are provided. The volume of the space above the fuel level is opened by opening the communication port when the volume of the space above the liquid level and the space above the fuel level becomes larger than a predetermined volume. In a fuel storage device having a shut-off valve that closes and shuts off the communication port when is smaller than the predetermined volume, the volume of the space above the fuel level is larger than the predetermined volume. And when the shut-off valve is opened, by using a means other than refueling into the fuel chamber, the gas in the space above the fuel level is discharged from above the fuel level via the communication port. The volume of the space above the fuel level is reduced Discharge volume of the fuel above the surface of liquid space is a gas from the fuel level upward through the communicating opening and closing small a shut-off valve than the volume of said predetermined is stopped. In the second invention, in the first invention,
After the gas is discharged from above the fuel level and the volume of the space above the fuel level becomes smaller than the predetermined volume and the shutoff valve closes, the amount of fuel in the fuel chamber decreases. Also, by keeping the shutoff valve closed, the volume of the space above the liquid surface of the fuel is kept smaller than the predetermined volume. According to a third aspect, in the second aspect, the shutoff valve is a shutoff valve that is closed by the fuel that has reached the shutoff valve. Four
According to a second aspect, in the first aspect, a liquid level detecting means for detecting the position of the fuel liquid level in the fuel chamber is provided, and the position of the fuel liquid level detected by the liquid level detecting means is predetermined. When the height has not been reached, it is determined that the volume of the space above the liquid surface of the fuel is larger than the predetermined volume. In a fifth aspect based on the first aspect, the gas is discharged from above the fuel level via the communication port by raising the fuel level in the fuel chamber. In a sixth aspect based on the fifth aspect, the fuel liquid level in the fuel chamber is raised by deforming the membrane wall. In a seventh aspect based on the sixth aspect, an air chamber is formed inside the fuel storage device by the membrane wall, and the membrane wall is deformed by pressurizing the air chamber. In an eighth aspect based on the sixth aspect, the membrane wall is deformed by introducing a negative pressure into a space above the fuel liquid level in the fuel chamber. A ninth aspect of the invention is the fuel cell system according to the eighth aspect, further comprising a pump for pumping fuel from the fuel chamber, wherein the negative pressure generated by the fuel pumped by the pump is above the fuel liquid level in the fuel chamber. Is introduced into the space through the communication port. 1
In the 0th invention, in the 9th invention, a part of the fuel pumped out by the pump is returned to the fuel chamber, and a negative pressure is generated by the reflux fuel returned to the fuel chamber.
In an eleventh aspect based on the ninth aspect, the pump is housed in a pump chamber connected to the fuel chamber, and a part of the fuel pumped out by the pump is returned to the pump chamber, The negative pressure generated by the recirculated fuel returned to is also introduced into the space above the fuel level in the pump chamber. In a twelfth aspect based on the eighth aspect, the communication port is connected to an intake system, and the negative pressure of the intake system is introduced into the space above the fuel liquid level in the fuel chamber through the communication port. It According to a thirteenth invention, in the twelfth invention, the communication port is connected to an intake system via a canister that adsorbs evaporated fuel, and the canister is opened below a predetermined negative pressure to open the canister. An atmosphere opening control valve that communicates with the atmosphere is provided. In a fourteenth aspect based on the twelfth aspect, the communication port is connected to an intake system, and the fuel liquid level in the fuel chamber is raised only when the engine operation is in a state capable of receiving evaporated fuel.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to the drawings. FIG. 1 shows the fuel tank of the first embodiment. In FIG. 1, the fuel tank 1 includes an upper portion 2 and a lower portion 3 made of, for example, a metal or a synthetic resin material. The upper part 2 and the lower part 3 are hermetically connected to each other at their peripheral flange portions 2a, 3a. Further, a separation membrane 5 is arranged in the internal space 4 defined by the upper portion 2 and the lower portion 3. The separation membrane 5 separates the internal space 4 into an air chamber 6 above the separation membrane 5 and a fuel chamber 7 below the separation membrane 5. Therefore, the separation membrane 5 corresponds to a membrane wall forming a fuel chamber and an air chamber inside the fuel tank 1. Further, the separation membrane 5 is made of a material having flexibility and impermeability to fuel vapor, such as polyethylene or nylon. Further, the separation membrane 5 is fixed to the fixing portion 8 at the peripheral edge portion 5a. As a result, the separation membrane 5 is airtightly fixed to the inner wall surface of the fuel tank 1. That is, the peripheral portion 5a of the separation membrane 5 is gripped and fixed between the peripheral flange portion 2a of the upper portion 2 and the peripheral flange portion 3a of the lower portion 3 over the entire circumference. Further, the separation membrane 5 is preliminarily formed with a plurality of annular folds 5b arranged substantially concentrically. Therefore, the vertical cross-sectional shape of the separation film 5 is wavy. Since the separation membrane 5 can be deformed along these folds 5b, the central portion 5c of the separation membrane 5 can move up and down. That is, it can be said that the separation film 5 is deformed so that the central portion 5c moves up and down when viewed as the entire separation film 5. The fold lines of this embodiment are formed at substantially equal intervals.

A fuel injection pipe 13 is hermetically connected to the fuel chamber 7. A fuel cap 14 is detachably attached to the upper end opening 13 a of the fuel injection pipe 13. Top opening 1
In the fuel injection pipe 13 adjacent to 3a, the fuel cap 1
4, a seal member 15 that contacts the outer peripheral surface of the fuel cap 14 when inserted, and a seal member 16 that contacts the outer peripheral surface of the fueling nozzle inserted into the fuel injection pipe 13 during refueling.
And an evaporated fuel cutoff valve 17 that normally shuts off the fuel injection pipe 13 by a spring force. On the other hand, the fuel injection pipe 1
A check valve 10 is attached to the lower end opening 13b of the check valve 3. The check valve 10 is opened by the pressure of the fuel to be refueled and closed by the fuel pressure in the fuel chamber 7.

Further, the fuel chamber 7 is connected to a fuel pump chamber 18 defined by a lower portion 3 protruding outward from a peripheral flange portion 2a of the upper portion 2. Fuel pump room 1
8, a fuel pump 19, a fuel pressure regulator 20,
The fuel filter 21 is arranged. The fuel discharged from the fuel pump 19 is regulated by a fuel pressure regulator 20 and then supplied to a fuel injection valve (not shown) via a fuel supply pipe 22. When the fuel pressure regulator 20 is arranged in the fuel pump chamber 18 which communicates with the fuel chamber 7 as described above, the fuel from the fuel distribution pipe (not shown) for distributing the fuel from the fuel supply pipe 22 to each fuel injection valve is connected to the fuel tank. It is not necessary to provide a fuel return passage extending to 1. Further, fuel containing evaporated fuel that is heated and partially vaporized in the vicinity of the cylinder head does not return to the inside of the fuel tank 1. Therefore, the generation of evaporated fuel in the fuel tank 1 is suppressed. In addition, the fuel pump 19 is installed in the fuel tank 1.
By disposing, the noise of the fuel pump 19 can be reduced.

The fuel chamber 7 of the fuel tank 1 is connected to the fuel injection pipe 13 via a circulation pipe 23. The circulation pipe 23 is attached to the lower portion 3 of the fuel tank 1. In addition, the circulation pipe 2
3 is above the outlet end of the fuel injection pipe 13 and is the fixed part 8
Immediately below it opens into the fuel chamber 7. Therefore, the circulation pipe 23 releases gas in the space above the liquid surface of the fuel whose volume gradually decreases during refueling to the fuel injection pipe 13 to facilitate refueling. A first cutoff valve 30 is attached to the opening of the circulation pipe 23 that opens into the fuel chamber 7. When the liquid fuel level in the fuel chamber 7 reaches the circulation pipe 23, the first shutoff valve 30 is closed by the liquid fuel level. Therefore, the circulation pipe 23
The fuel reaches the circulation pipe 23 and the circulation pipe 23 causes the first cutoff valve 3
The negative pressure in the vicinity of the opening of the circulation pipe 23 that opens to the fuel injection pipe 13 when closed by 0 is increased. The opening of the circulation pipe 23 that opens in the fuel chamber 7 corresponds to a communication port that opens in the space above the fuel liquid level, and the first shutoff valve 30 corresponds to a shutoff valve that shuts off this communication port.

The upper space 18a of the fuel pump chamber 18 is connected to the fuel injection pipe 13 via an evaporated fuel discharge pipe (hereinafter, also simply referred to as "discharge pipe") 24. The discharge pipe 24 is attached to an upper wall portion that defines the fuel pump chamber 18. Therefore, the discharge pipe 24 releases the gas in the upper space above the liquid surface of the fuel whose volume gradually decreases during refueling to the fuel injection pipe 13 to facilitate refueling. A second cutoff valve 31 is attached to the opening of the discharge pipe 24 that opens into the fuel pump chamber 18. The second shutoff valve 31 is closed by the fuel liquid level in the fuel chamber 7 when it reaches the discharge pipe 24. Therefore, the exhaust pipe 24 increases the negative pressure in the vicinity of the opening of the exhaust pipe 24 that opens to the fuel injection pipe 13 when the fuel reaches the exhaust pipe 24 and the exhaust pipe 24 is closed by the second cutoff valve 31. The opening of the discharge pipe 24 with respect to the fuel injection pipe 13 is located above the opening of the circulation pipe 23 with respect to the fuel injection pipe 13. The opening of the discharge pipe 24 that opens into the fuel pump chamber 18 corresponds to a communication port that opens in the space above the fuel liquid level, and the second shutoff valve 31 corresponds to a shutoff valve that shuts off this communication port.

The fuel injection pipe 13 is the first evaporated fuel purge pipe 2
It is connected to a charcoal canister (hereinafter, simply referred to as “canister”) 26 via 5. The opening of the first evaporated fuel purge pipe 25 with respect to the fuel injection pipe 13 is the fuel injection pipe 13
Is almost the same height as the opening of the evaporated fuel discharge pipe 24 with respect to. The canister 26 is an activated carbon 26a that adsorbs evaporated fuel.
Is provided inside. Further, the canister 26 is opened to the atmosphere via the atmosphere open pipe 28. Further, the canister 26 is connected to an engine intake passage (not shown) via a second evaporated fuel purge pipe 27.

Therefore, in the fuel chamber 7, the fuel injection pipe 13
The evaporated fuel generated inside the fuel pump chamber 18 is guided to the canister 26 through the circulation pipe 23, the evaporated fuel discharge pipe 24, and the first evaporated fuel purge pipe 25, and the activated carbon 2
Adsorbed to 6a. Therefore, the evaporated fuel is prevented from being released into the atmosphere. The fuel adsorbed on the activated carbon 26a is purged into the engine intake passage via the second evaporated fuel purge pipe 27 according to the engine operating state (engine load).

When the vehicle accelerates, decelerates, or turns, the fuel in the fuel chamber 7 swings, so that the separation membrane 5 moves in the horizontal direction. Therefore, a large load such as tensile stress or compressive stress acts on the separation membrane 5. In this embodiment, as shown in FIG. 2, the inner wall surface of the side wall 3b of the lower portion 3 is inclined as a whole from the fixed portion 8 to the bottom wall 3c of the lower portion 3 as it goes downward. This limits the horizontal movement of the separation membrane 5 regardless of the position of the separation membrane 5. Further, a plurality of substantially annular projecting portions 29 projecting inward are provided on the inner wall surface of the side wall 3b of the lower portion 3, and the inner wall surface of the side wall 3b has a stepwise cross section. Since the projecting portion 29 projects inward as described above, when the separation membrane 5 rocks, the separation membrane 5
Quickly contacts the protrusion 29. Thereby, the separation membrane 5
Further restricts the horizontal and vertical movement of the. Further, the protruding portion 29 is continuously formed from the fixed portion 8 toward the bottom wall 3c, and a concave portion is formed between a pair of adjacent protruding portions 29. These recesses are folds 5b protruding downward.
To keep the inside of the separator, the movement of the separation membrane 5 is further restricted. In this way, the undesired large load is prevented from acting on the separation membrane 5, and the breakage of the separation membrane 5 is prevented.
Further, the protrusion 29 makes the volume of the air layer formed between the fuel liquid surface and the separation membrane 5 extremely small. Therefore, the amount of evaporated fuel generated in the fuel chamber 7 is extremely small. Moreover, since the protrusion 29 enhances the rigidity of the lower portion 3, it is not necessary to add a reinforcing member.

A plurality of springs 32 are attached to the inner wall surface of the upper portion 2 of the fuel tank 1 as biasing means. Each spring 32 extends freely downward from the inner wall surface of the upper part 2.
These springs 32 contact the central portion 5c of the rising separation membrane 5. This prevents the separation membrane 5 from colliding strongly with the inner wall surface of the upper portion 2.

The air chamber 6 is communicated with the atmosphere via an atmosphere communication pipe 33. The atmosphere communication pipe 33 is attached to the upper portion 2 of the fuel tank 1. Therefore, the atmosphere communication pipe 33 releases the gas in the air chamber 6 whose volume gradually decreases due to the separation membrane 5 rising during refueling to the atmosphere to facilitate refueling. Further, the atmosphere communication pipe 33 introduces gas into the air chamber 6 whose volume gradually increases due to the separation membrane 5 that descends during engine operation, and facilitates the separation membrane 5 to descend.

Next, the evaporative fuel elimination action of the first embodiment for eliminating the evaporative fuel in the upper space above the fuel liquid surface, that is, the space between the separation membrane and the fuel liquid surface will be briefly described. First
In the embodiment, the fuel liquid level is raised by the hydraulic pressure and the evaporated fuel above the fuel liquid level is discharged from the fuel tank. After the evaporated fuel is completely discharged from the fuel chamber, the fuel chamber is sealed and refueling is completed. As a result, the evaporated fuel existing in the fuel chamber before refueling is discharged to the outside of the fuel tank. Further, after refueling, the fuel chamber is maintained in a hermetically sealed state in a state where there is no evaporated fuel in the fuel chamber. Therefore, even if the fuel is consumed, formation of the upper space above the liquid surface of the fuel is suppressed. Therefore, according to the first embodiment, the generation of evaporated fuel in the fuel chamber is suppressed. In the first embodiment, refueling corresponds to the gas discharging means or the liquid level raising means.

Next, the evaporative fuel discharge operation of the first embodiment will be described with reference to the drawings. FIG. 1 shows the fuel tank in a state where the evaporated fuel exists in the fuel chamber. When refueling, the fuel cap 14 is removed from the upper end opening 13a of the fuel injection pipe 13. Since the evaporated fuel cutoff valve 17 is closed when the fuel cap 14 is removed, the evaporated fuel is prevented from being released from the upper end opening 13a of the fuel injection pipe 13 to the atmosphere. Next, a fueling nozzle (not shown) is inserted into the upper end opening 13a of the fuel injection pipe 13, and the tip of the fueling nozzle opens the evaporated fuel cutoff valve 17 against the spring bias. At this time, the seal member 1 is provided on the outer peripheral surface of the fuel nozzle.
Since 6 contacts, the evaporative fuel is prevented from being released from the upper end opening 13a of the fuel injection pipe 13 to the atmosphere even when the fueling nozzle is inserted.

Next, when refueling is started, fuel is injected into the fuel chamber 7 through the fuel injection pipe 13. When the amount of fuel in the fuel chamber 7 increases, the liquid surface of the fuel rises and therefore the separation membrane 5 rises. Also, while the fuel level is rising,
The evaporated fuel above the liquid surface of the fuel is discharged from the fuel tank 1 through the circulation pipe 23 and the evaporated fuel discharge pipe 24. In addition,
When the fuel liquid level rises, the separation membrane 5 is kept in close contact with the fuel liquid level, so that the amount of evaporated fuel generated in the fuel tank 1 during refueling can be suppressed to a small amount.

When the liquid surface of the fuel reaches the circulation pipe 23, the first shutoff valve 30 is closed by the fuel. When refueling is further continued, the central portion 5c of the separation membrane 5 comes into contact with the spring 32 and the rise of the separation membrane 5 is suppressed. When refueling is further continued and the fuel liquid level reaches the evaporated fuel discharge pipe 24, the second shutoff valve 31 is closed by the fuel. The fuel tank at this time is shown in FIG. Thus, the evaporated fuel above the liquid surface of the fuel is completely discharged from the fuel chamber 7. When the first shutoff valve 30 and the second shutoff valve 31 are closed, the negative pressure in the fuel injection pipe 13 increases to a predetermined value or higher. When this negative pressure is detected by the negative pressure detecting means provided in the refueling nozzle, refueling is automatically stopped. At the same time, the fuel chamber 7
Since the pressure of the fuel inside is higher than the hydraulic pressure, the check valve 1
0 is closed. Therefore, the upper space above the liquid surface of the fuel and the evaporated fuel in this upper space are completely removed, and the fuel chamber is maintained in a sealed state. When refueling is completed and the refueling nozzle is pulled out, the fuel vapor cutoff valve 1
7 is closed again and then the fuel cap 14 is installed.

Next, the operation of the first embodiment during engine operation will be described. When the engine operation is started and the amount of fuel in the fuel chamber 7 decreases, the fuel liquid level in the fuel chamber 7 gradually lowers, so that the separation membrane 5 lowers. At this time, the center surface of the separation membrane 5 comes to project into the fuel chamber 7 (see FIG. 4). Since the inside of the fuel chamber 7 is hermetically closed, no space is formed between the fuel liquid surface and the separation membrane 5 while the fuel liquid surface and the separation membrane 5 descend. In this way, after the evaporated fuel discharging operation of the first embodiment is performed, the generation of evaporated fuel in the fuel chamber 7 is suppressed. Further, when the generation of the evaporated fuel in the fuel chamber 7 is suppressed, the canister can be downsized, or the canister itself can be omitted.

When the vehicle accelerates, decelerates, or turns, the fuel in the fuel chamber fluctuates. At this time, the first shutoff valve or the second shutoff valve may open in the fuel tank of the first embodiment. Therefore, a space is formed between the separation membrane and the liquid surface of the fuel, and evaporated fuel is generated in this space. Therefore, it is necessary to exclude the space between the separation membrane and the liquid surface of the fuel and the evaporated fuel in this space by means other than refueling. So the second
In the embodiment, the evaporative fuel discharge function is executed by means other than refueling.

A second embodiment will be described with reference to the drawings.
FIG. 5 shows a fuel tank of the second embodiment. In the second embodiment, the air chamber 6 is connected to the pump 35 via the first connection pipe 34 instead of the atmosphere communication pipe 33 of the first embodiment. The pump 35 serves to increase the pressure in the air chamber 6. First
The connection pipe 34 is connected to the relief valve 37 via the second connection pipe 36. The relief valve 37 opens when the pressure in the air chamber 6 is higher than a predetermined pressure to reduce the pressure in the air chamber 6. The predetermined pressure is set lower than the pressure that damages the separation membrane. Further, the diaphragm 38 of the relief valve 37 is provided with a small diameter hole 39. The small-diameter hole 39 communicates the atmosphere with the second connecting pipe 36 regardless of whether the relief valve 37 is opened or closed. The diameter of the hole 39 is such that it does not prevent the pressure in the air chamber 6 from increasing due to the operation of the pump 35. Fuel pump room 1
A level switch 57 is attached at the maximum height position in the position 8. The level switch 57 outputs a voltage when the liquid surface of the fuel reaches the level switch 57, that is, when it reaches the maximum height position in the fuel tank 1.

In FIG. 5, a control unit (ECU) 40 comprises a digital computer, and a CPU (microprocessor) 4 connected to each other via a bidirectional bus 41.
2, RAM (random access memory) 43, ROM
A (read only memory) 44, a B-RAM (backup random access memory) 45, an input port 46 and an output port 47 are provided. When the fuel level reaches the level switch 57, the output voltage of the level switch 57 is input to the input port 46 via the AD converter 48.
Also, the output voltage indicating whether the relief valve 37 is opened or closed is A
It is input to the input port 46 via the D converter 48. On the other hand, the output port 47 is connected to the pump 35 via the drive circuit 49.
Connected to. The configuration other than the above-described configuration of the second embodiment is the same as that of the first embodiment, and thus the description thereof will be omitted.

Next, the evaporative fuel discharge operation of the second embodiment will be described. In the second embodiment, when the relief valve 37 is closed, it is determined that the pressure in the air chamber 6 is a pressure at which the evaporated fuel discharging action can be executed. On the other hand, when the relief valve 37 is open, it is determined that the pressure in the air chamber 6 is not the pressure at which the evaporated fuel discharging action can be executed.

When the level switch 57 is off, it is judged that it is necessary to execute the evaporative fuel discharge action. On the other hand, when the level switch 57 is on, it is determined that it is not necessary to execute the evaporative fuel discharge action.

When it is judged that the pressure in the air chamber 6 is a pressure capable of executing the evaporative fuel discharge action and it is necessary to execute the evaporative fuel discharge action, the pump 35 is operated to operate the pressure in the air chamber 6 Increase. As a result, the separation membrane 5 is lowered downward toward the bottom wall of the fuel tank 1. Therefore, the fuel liquid level that is not in close contact with the separation membrane 5 is raised. At this time, the evaporated fuel between the separation membrane 5 and the liquid surface of the fuel is discharged from the fuel tank through the circulation pipe 23 and the evaporated fuel discharge pipe 24. Therefore, according to the second embodiment, the evaporative fuel discharging action is executed by means other than refueling. In the second embodiment, the pump that pressurizes the air chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch corresponds to the liquid level detecting means.

When it is determined that the pressure in the air chamber 6 is a pressure at which the evaporative fuel discharge action cannot be performed, or when it is determined that the evaporative fuel discharge action need not be performed, the pump 35 is stopped. ..

FIG. 6 is a flow chart showing the evaporative fuel discharge operation in the second embodiment. Step S210
At, it is determined whether or not the level switch is on. When it is determined in step S210 that the level switch is on, the process proceeds to step S212, the pump is stopped, and the process ends. On the other hand, if it is determined in step S210 that the level switch is off, then step S21
Go to 4. In step S214, it is determined whether or not the relief valve is open. When it is determined in step S214 that the relief valve is open, the process proceeds to step S212, the pump is stopped, and the process ends.
On the other hand, when it is determined in step S214 that the relief valve is closed, the process proceeds to step S216, the pump is operated, and the process ends.

By the way, in the evaporative fuel discharge operation of the first embodiment, it is necessary to replenish the fuel to the full tank when refueling. Therefore, when refueling is completed before the tank is full, the space between the separation membrane and the fuel liquid level and the evaporated fuel in this space cannot be completely discharged. Therefore, in the third embodiment, even if the refueling is completed before the tank is full, the space between the separation membrane and the fuel liquid surface and the evaporated fuel in this space are completely discharged.

A third embodiment will be described with reference to the drawings.
FIG. 7 shows a fuel tank of the third embodiment. The fuel tank of the third embodiment has a cap lid opener switch (hereinafter, also simply referred to as “switch”) 50 in addition to the second embodiment.
It is equipped with. The switch 50 is connected to a cap lid (not shown) that covers the fuel cap 14. Switch 50
Is activated when opening the cap lid. Further, the switch 50 outputs a voltage after the switch 50 is operated until the cap lid is closed. It can be recognized from this output voltage that refueling is in progress. The output voltage of the switch 50 is input to the input port 46 via the AD converter 48.
Note that the configuration other than the above-described configuration of the third embodiment is similar to that of the second embodiment, so description will be omitted.

Next, the evaporative fuel discharge operation of the third embodiment will be described. In the third embodiment, when the relief valve 37 is closed, it is determined that the pressure in the air chamber 6 is a pressure at which the evaporated fuel discharging action can be executed. On the other hand, when the relief valve 37 is open, it is determined that the pressure in the air chamber 6 is not the pressure at which the evaporated fuel discharging action can be executed.

Also, the cap lid opener switch 50
Is ON and the level switch 57 is OFF, it is determined that the evaporative fuel discharge operation needs to be executed. On the other hand, when the cap lid opener switch 50 is on and the level switch 57 is on, it is determined that it is not necessary to execute the evaporated fuel discharging action.

When it is determined that the pressure in the air chamber 6 is a pressure at which the evaporative fuel discharge action cannot be performed, or when it is determined that the evaporative fuel discharge action need not be performed, the pump 35 is stopped and the cap is stopped. Allow the lid to open.

Further, when it is judged that the pressure in the air chamber 6 is a pressure capable of executing the evaporative fuel discharge action and it is necessary to execute the evaporative fuel discharge action, the pump 35 is operated to operate the air chamber 6 inside. Increase the pressure of. This makes the second
Similar to the embodiment, the evaporated fuel between the separation membrane 5 and the liquid surface of the fuel is discharged from the fuel tank through the circulation pipe 23 and the evaporated fuel discharge pipe 24. After that, when it is determined that the pressure in the air chamber 6 is a pressure at which the evaporative fuel discharge action cannot be performed, or when it is determined that the evaporative fuel discharge action need not be performed, the pump 35 is stopped and the cap lid is closed. Allow the release of. In the third embodiment, the pump that pressurizes the air chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch corresponds to the liquid level detecting means.

As a result, when the cap lid is opened to start refueling, the fuel level is already raised by the separation membrane 5 which is lowered due to the increase in pressure in the air chamber 6. Therefore, the fuel liquid level reaches the maximum height position in the fuel tank 1 with a small amount of refueling as compared with the case where the fuel level is not raised at the start of refueling. Therefore, according to the third embodiment, the space between the separation membrane and the fuel liquid level and the evaporated fuel in this space are completely eliminated even if refueling is not performed up to the full tank.

The refueling nozzle used for refueling the fuel tank of the third embodiment is different from the refueling nozzle used for refueling the fuel tank of the first embodiment and detects negative pressure around the fuel refueling nozzle. This is not the type in which refueling is stopped, but the type in which refueling is stopped when it is detected that the fuel in the fuel injection pipe has become higher than a predetermined position. The predetermined position is set lower than the opening of the circulation pipe with respect to the fuel injection pipe.

FIG. 8 is a flow chart showing the evaporative fuel discharge action in the third embodiment. Step S310
At, it is determined whether or not the cap lid opener switch 50 is on. Switch 5 in step S310
If it is determined that 0 is ON, the process proceeds to step S312. On the other hand, if it is determined in step S310 that the switch 50 is off, the process proceeds to step S318, the pump is stopped, and the process ends. In step S312, it is determined whether the level switch is on. Step S
If it is determined in 312 that the level switch is on, the process proceeds to step S314 to stop the pump, then proceeds to step S316 to permit the cap lid to be opened, and the process ends. On the other hand, if it is determined in step S312 that the level switch is off, the process proceeds to step S320. In step S320, it is determined whether the relief valve is open. Step S32
When it is determined that the relief valve is opened at 0, the process proceeds to step S314, the pump is stopped, and then the process proceeds to step S316 to permit the cap lid to be opened, and the process ends. On the other hand, if it is determined in step S320 that the relief valve is closed, the process proceeds to step S322, the pump is operated, and the process ends.

A pump and a relief valve are used in the evaporative fuel discharge operation of the second embodiment. Therefore, the structure of the fuel tank becomes complicated and the manufacturing cost increases. Therefore, in the fourth embodiment, the evaporated fuel discharging action is executed by the fuel tank having a simple structure.

A fourth embodiment will be described with reference to the drawings.
FIG. 9 shows a fuel tank of the fourth embodiment. In the fourth embodiment, the pump, the relief valve, the first connecting pipe and the second connecting pipe of the second embodiment are excluded, and the atmosphere communicating pipe 33 is attached to the upper portion 2. First evaporative fuel purge pipe 25
Is connected to the solenoid valve 51 instead of the canister 26 of the second embodiment. The solenoid valve 51 is connected to the engine intake passage 52 via the second evaporated fuel purge pipe 27. The solenoid valve 51 controls the presence or absence of communication between the fuel tank and the engine intake passage. Further, the fuel tank 1 of the fourth embodiment includes a temperature sensor 55 that generates an output voltage indicating the temperature of cooling water for cooling the engine (hereinafter, engine water temperature). The temperature sensor 55 is connected to the input port 46 via the corresponding AD converter 48. On the other hand, the output port 47 is connected to the solenoid valve 51 via the drive circuit 49. The configuration other than the above-described configuration of the fourth embodiment is the same as that of the second embodiment, and thus the description thereof is omitted.

Next, the evaporative fuel discharge action of the fourth embodiment will be described. In the fourth embodiment, when the engine water temperature is higher than a predetermined water temperature (for example, 70 ° C.), it is determined that the engine state is in a state capable of executing the evaporated fuel discharge action. On the other hand, when the engine water temperature is equal to or lower than the predetermined water temperature, it is determined that the engine state is in a state where the evaporated fuel discharging operation cannot be executed. The predetermined water temperature is set to the temperature when the cooling water cools the engine in the steady operation state.

When the level switch 57 is off, it is judged that it is necessary to execute the evaporative fuel discharge operation. On the other hand, when the level switch 57 is on, it is determined that it is not necessary to execute the evaporative fuel discharge action.

When it is determined that the engine state is such that the evaporative fuel discharge operation can be executed and the evaporative fuel discharge operation needs to be executed, the solenoid valve 51 is opened and the second evaporated fuel purge pipe 27, A negative pressure in the engine intake passage 52 is introduced into the fuel chamber 7 via the first evaporated fuel purge pipe 25, the circulation pipe 23 and the evaporated fuel discharge pipe 24. This eliminates the space between the liquid surface of the fuel and the separation membrane and the evaporated fuel in this space. Therefore, according to the fourth embodiment, the evaporated fuel discharging operation is executed by the fuel tank having a simple structure that does not use the pump and the relief valve.

When it is determined that the engine state is in a state where the evaporative fuel discharge action cannot be executed, or when it is determined that it is not necessary to perform the evaporative fuel discharge action,
The solenoid valve 51 is closed. Further, in the fourth embodiment, the purging action for introducing the negative pressure in the engine intake passage into the fuel chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch corresponds to the liquid level detecting means.

It should be noted that, in addition to the water temperature, the presence or absence of execution of the evaporated fuel discharge action may be controlled based on the number of revolutions of the internal combustion engine, the engine load, the amount of intake air, or the state of combustion. As the engine load is lower, the intake air amount is smaller, and the combustion is stratified combustion, the above operation is stopped.

FIG. 10 is a flow chart showing the evaporative fuel discharge operation in the fourth embodiment. Step S41
At 0, it is determined whether or not the level switch is on.
If it is determined in step S410 that the level switch is on, the flow advances to step S412 to close the solenoid valve, and the process ends. On the other hand, if it is determined in step S410 that the level switch is off, the process proceeds to step S414, where the engine water temperature T is the predetermined water temperature T.
_It is determined whether it is greater than ₀ . If it is determined in step S414 that the engine water temperature T is higher than the predetermined water temperature T ₀ , the process proceeds to step S416, the solenoid valve is opened, and the process ends. On the other hand, if it is determined in step S414 that the engine water temperature T is equal to or lower than the predetermined water temperature T ₀ , the process proceeds to step S412 to close the electromagnetic valve and terminate the process.

When a canister for adsorbing the evaporated fuel is required in the fuel tank of the fourth embodiment, the canister is attached to the first evaporated fuel purge pipe between the fuel injection pipe and the solenoid valve. The canister is in communication with the atmosphere so that when the negative pressure in the engine intake passage is introduced into the canister, the inside of the canister does not become extremely low and the pressure inside the fuel tank does not become extremely high. However, since the fourth embodiment is a system that performs the evaporative fuel discharge action by using the intake pipe negative pressure, when the evaporative fuel discharge action is executed, the atmosphere is introduced into the canister to reduce the negative pressure in the engine intake passage. It cannot be introduced into the fuel chamber. Therefore, in the fifth embodiment, in the fuel tank having the canister, the negative pressure in the engine intake passage can be introduced into the fuel chamber.

A fifth embodiment will be described with reference to the drawings.
FIG. 11 shows a fuel tank of the fifth embodiment. In the fifth embodiment, in addition to the configuration of the fourth embodiment, a canister 26 is attached to the first evaporated fuel purge pipe 25 between the fuel injection pipe 13 and the electromagnetic valve 51. The canister 26 is the atmosphere open pipe 2
It is opened to the atmosphere via 8. An atmosphere opening control valve 58 is attached to the atmosphere opening pipe 28. Atmosphere release control valve 5
Reference numeral 8 is composed of a positive pressure valve and a negative pressure valve, and is opened at a predetermined positive pressure or more to reduce the pressure in the canister 26,
The valve is opened below a predetermined negative pressure to increase the pressure in the canister 26. The predetermined positive pressure is higher than the pressure at which the fuel tank, the canister, the parts communicating with them, and the separation membrane can withstand the strength, or the pressure at which the evaporated fuel does not leak from the fuel tank, the canister, and the parts communicating with them. The negative pressure, which is set to a small value and is set in advance, is set to be higher than the pressure that the fuel tank, the canister, the parts communicating with them, and the separation membrane can withstand the strength. Further, the configuration other than the above-described configuration of the fifth embodiment is the same as that of the fourth embodiment, and thus the description thereof will be omitted.

Next, the evaporative fuel discharge operation of the fifth embodiment will be described. In the fifth embodiment, when the engine water temperature is higher than a predetermined water temperature, it is determined that the engine state is in a state capable of executing the evaporated fuel discharge action. On the other hand, when the engine water temperature is equal to or lower than the predetermined water temperature, it is determined that the engine state is in a state where the evaporated fuel discharging operation cannot be executed. In addition,
The predetermined water temperature is set to the temperature when the cooling water cools the engine in the steady operation state.

When the level switch 57 is off, it is judged that it is necessary to execute the evaporated fuel discharging operation. On the other hand, when the level switch 57 is on, it is determined that it is not necessary to execute the evaporative fuel discharge action.

When it is determined that the engine state is such that the evaporative fuel discharging operation can be executed and the evaporative fuel discharging operation needs to be executed, the solenoid valve 51 is opened to open the second evaporated fuel purge pipe 27. The negative pressure in the engine intake passage 52 is introduced into the canister 26 via the. Canister 2 at this time
When the pressure in 6 is lower than the predetermined positive pressure and higher than the predetermined negative pressure, the atmosphere opening control valve 58 is closed, so the first evaporated fuel purge pipe 25 and the circulation pipe 23.
And, the negative pressure in the engine intake passage 52 is introduced into the fuel chamber 7 via the evaporated fuel discharge pipe 24. This eliminates the space between the liquid surface of the fuel and the separation membrane and the evaporated fuel in this space. Therefore, according to the fifth embodiment, the negative pressure in the engine intake passage is introduced into the fuel chamber in the fuel tank equipped with the canister. As a result, the evaporative fuel discharge action is sufficiently executed.

When it is determined that the engine state is in a state where the evaporative fuel discharge action cannot be executed, or when it is determined that the evaporative fuel discharge action need not be executed,
The solenoid valve 51 is closed. Further, when the pressure inside the canister 26 is equal to or higher than a predetermined positive pressure or equal to or lower than a predetermined negative pressure, the atmosphere opening control valve 58 is opened. Further, in the fifth embodiment, the purging action for introducing the negative pressure in the engine intake passage into the fuel chamber corresponds to the gas discharging means or the liquid level increasing means, and the level switch corresponds to the liquid level detecting means.

FIG. 12 is a flow chart showing the evaporative fuel discharging action in the fifth embodiment. Step S51
At 0, it is determined whether or not the level switch is on.
When it is determined in step S510 that the level switch is on, the process proceeds to step S514, the electromagnetic valve is closed, and the process ends. On the other hand, if it is determined in step S510 that the level switch is off, the process proceeds to step S516, where the engine water temperature T is the predetermined water temperature T.
_It is determined whether it is greater than ₀ . When it is determined in step S516 that the engine water temperature T is higher than the predetermined water temperature T ₀ , the process proceeds to step S518, the solenoid valve is opened, and the process ends. On the other hand, when it is determined in step S516 that the engine water temperature T is equal to or lower than the predetermined water temperature T ₀ , the process proceeds to step S512 to open the atmosphere release control valve, and then proceeds to step S514 to close the solenoid valve. And the process ends.

By the way, in the third embodiment, when the pump is operated, the pressure in the air chamber is maintained at the valve opening pressure of the relief valve. On the other hand, when the fuel level reaches the maximum height position in the fuel tank and the pump is stopped, the pressure in the air chamber is released from the hole of the relief valve and maintained at atmospheric pressure. After the pump is stopped, opening of the cap lid is permitted and refueling is executed. The holes of the relief valve of the third embodiment are small so as not to hinder the pressure rise in the air chamber, and therefore it takes time to release the pressure by the holes of the relief valve. Therefore, if the pressure in the air chamber is higher than the refueling pressure when refueling is executed, refueling cannot be executed and the fuel tank cannot be filled up. Therefore, in the sixth embodiment, the pressure in the air chamber is made lower than the refueling pressure when refueling is executed.

A sixth embodiment will be described with reference to the drawings.
FIG. 13 shows a fuel tank of the sixth embodiment. In the sixth embodiment, in addition to the configuration of the third embodiment, the second relief valve 59 is connected to the second connection pipe 36. Second relief valve 59
Opens when the pressure in the air chamber 6 is higher than a predetermined second pressure, and releases the pressure in the air chamber 6. In addition,
The predetermined second pressure is set lower than the oil supply pressure. In addition, the amount of air released through the second relief valve 59 when the second relief valve 59 is opened is smaller than the air discharge amount of the pump, and the air released through the hole 39 of the relief valve 37. Greater than quantity. The configuration other than the above-described configuration of the sixth embodiment is the same as that of the third embodiment, and thus the description thereof will be omitted.

Next, the evaporative fuel discharge action of the sixth embodiment will be described. The evaporative fuel discharge action until the fuel level reaches the maximum height position in the fuel tank or the relief valve is opened and the pump is stopped is the same as that in the third embodiment, so description thereof will be omitted. In the sixth embodiment, when the pressure in the air chamber 6 is higher than the predetermined second pressure when the pump 35 is stopped, the second relief valve 59 opens.
Therefore, the pressure in the air chamber 6 reaches a predetermined second pressure smaller than the oil supply pressure earlier than in the third embodiment that does not include the second relief valve. Therefore, according to the sixth embodiment, the pressure in the air chamber can be made smaller than the refueling pressure when refueling is executed. As a result, the evaporative fuel discharge action is sufficiently executed. In the sixth embodiment, the pump that pressurizes the air chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch corresponds to the liquid level detecting means.

The flow chart of the evaporated fuel discharging operation of the sixth embodiment is the same as that of the third embodiment, and therefore its explanation is omitted.

By the way, in the sixth embodiment, during the operation of the pump, when the pressure in the air chamber is higher than the predetermined second pressure, the pressure in the air chamber is increased while the pressure is released from the second relief valve. That is, the rate of increase in the pressure in the air chamber in the sixth embodiment is smaller than the rate of increase in the sixth embodiment without the second relief valve. Therefore, the time required to permit the opening of the cap lid in the sixth embodiment is longer than the time in the third embodiment. Therefore, in the seventh embodiment, the rate of increase of the pressure in the air chamber is made larger than that in the sixth embodiment.

The seventh embodiment will be described with reference to the drawings.
FIG. 14 shows a fuel tank of the seventh embodiment. In the seventh embodiment, an electromagnetic valve 60 is connected to the second connecting pipe 36 instead of the relief valve and the second relief valve of the sixth embodiment. The solenoid valve 60 is connected to the output port 47 via the corresponding drive circuit 49, and the ECU 40 controls opening / closing. The solenoid valve 60 controls the presence or absence of communication between the air chamber 6 and the atmosphere. In addition, an air chamber 6 is provided in the upper portion 2 of the fuel tank 1.
A pressure sensor 61 for measuring the pressure inside is attached.
The pressure sensor 61 is connected to the input port 46 via the corresponding AD converter 48. The configuration other than the above-described configuration of the seventh embodiment is similar to that of the sixth embodiment, and thus the description thereof will be omitted.

Next, the evaporative fuel discharge operation of the seventh embodiment will be described. In the seventh embodiment, when the pressure in the air chamber 6 is lower than a predetermined pressure, it is determined that the state of the engine and the fuel tank 1 is in a state capable of executing the evaporated fuel discharging action. The predetermined pressure is set lower than the pressure that damages the separation membrane. On the other hand, when the pressure in the air chamber 6 is equal to or higher than the predetermined pressure, it is determined that the state of the engine and the fuel tank 1 is in a state in which the evaporated fuel discharge function cannot be executed.

Also, the cap lid opener switch 50
Is ON and the level switch 57 is OFF, it is determined that the evaporative fuel discharge operation needs to be executed. On the other hand, when the cap lid opener switch 50 is on and the level switch 57 is on, it is determined that it is not necessary to execute the evaporated fuel discharging action.

Further, when the pressure in the air chamber 6 is lower than the predetermined second pressure, it is determined that the pressure in the air chamber 6 is in a state where the opening of the cap lid can be permitted. In addition,
The predetermined second pressure is set lower than the oil supply pressure. On the other hand, when the pressure in the air chamber 6 is equal to or higher than the predetermined second pressure, it is determined that the pressure in the air chamber 6 is in a state in which the cap lid cannot be opened.

When it is determined that the state of the engine and the fuel tank 1 is capable of performing the evaporative fuel discharge action and it is necessary to perform the evaporative fuel discharge action, the electromagnetic valve 60 is closed and the pump 35 is turned on. It operates to increase the pressure in the air chamber 6. As a result, the evaporated fuel between the separation membrane 5 and the liquid surface of the fuel is discharged from the fuel tank through the circulation pipe 23 and the evaporated fuel discharge pipe 24. When it is determined that it is not necessary to execute the evaporative fuel discharge operation while the pressure in the air chamber 6 is increasing, the pump 35 is stopped and the electromagnetic valve 60 is opened to allow the cap lid to be opened. Further, when it is determined that the pressure in the air chamber 6 is in a state in which the evaporated fuel discharge function cannot be executed while the pressure in the air chamber 6 is increasing, the pump 35 is stopped and the solenoid valve 60 is opened. Thereafter, when it is determined that the pressure in the air chamber 6 is in a state where the opening of the cap lid can be permitted, the opening of the cap lid is permitted.
On the other hand, when it is determined that the pressure in the air chamber 6 is in a state where the opening of the cap lid is not permitted, the pump 35 is stopped and the electromagnetic valve 60 is kept open. Therefore, according to the seventh embodiment, since the pressure in the air chamber is not released during the operation of the pump, the rate of increase in the pressure in the air chamber is larger than that in the sixth embodiment. In the seventh embodiment, the pump that pressurizes the air chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch corresponds to the liquid level detecting means.

FIG. 15 is a flow chart showing the evaporative fuel discharge action in the seventh embodiment. Step S71
At 0, it is determined whether or not the cap lid opener switch 50 is on. If it is determined in step S710 that the switch 50 is on, the process proceeds to step S712. On the other hand, if it is determined in step S710 that the switch 50 is off, the process proceeds to step S722 to close the solenoid valve, next proceeds to switch 724 to stop the pump, and then proceeds to step S726 to proceed to the refueling flag. Is reset and the process ends. The refueling flag is set when the pressure in the air chamber once exceeds the maximum pressure, and is reset when the switch 50 is turned off.

In step S712, it is determined whether the level switch is on. When it is determined in step S712 that the level switch is off, step S7
Proceed to 14. On the other hand, if it is determined in step S712 that the level switch is on, then step S742
The process proceeds to step S744 to stop the pump, and then proceeds to step S744 to open the solenoid valve, and then proceeds to step S746 to permit opening of the cap lid and terminate the process.

In step S714, the pressure P detected by the pressure sensor is smaller than a predetermined pressure P _max (P <
P _max ). When it is determined that the P <P _{m ax} at step S714, step S716
Proceed to. On the other hand, if it is determined in step S714 that P ≧ P _max , the process proceeds to step S728 to set the refueling flag, then proceeds to step S730 to open the solenoid valve, and then proceeds to step S732.

In step S716, it is determined whether or not the refueling flag has been reset. If it is determined in step S716 that the refueling flag has been reset, the process proceeds to step S718 to close the electromagnetic valve, then proceeds to step S720 to operate the pump, and the process ends. On the other hand, if it is determined in step S716 that the refueling flag is set, then the flow proceeds to step S732.

In step S732, the pressure P detected by the pressure sensor is smaller than the predetermined second pressure P ₂ (P <
P ₂ ) or not. If it is determined in step S732 that P <P ₂ , the process proceeds to step S734 to close the electromagnetic valve, then proceeds to step S736 to operate the pump, and then proceeds to step S738 to open the cap lid. Is permitted, and the process ends. On the other hand, step S
If P ≧ P ₂ is determined in 732, the process proceeds to step S739, the pump is stopped, and then step S7.
The routine proceeds to 40, the solenoid valve is opened, and the processing ends.

By the way, in the second embodiment, when the rate of increase of the pressure in the air chamber due to the operation of the pump is large, the fuel liquid level undulates. For this reason, the first shutoff valve or the second shutoff valve may open and fuel may leak into the evaporated fuel discharge pipe or the circulation pipe. Therefore, in the eighth embodiment, the increase rate of the pressure in the air chamber is set to the increase rate at which the fuel level does not swell.

The eighth embodiment will be described with reference to the drawings.
FIG. 16 shows a fuel tank of the eighth embodiment. In the eighth embodiment, a solenoid valve 6 is used instead of the relief valve of the second embodiment.
0 is connected to the second connecting pipe 36. The solenoid valve 60 is connected to the output port 47 via the corresponding drive circuit 49,
The opening and closing is controlled by the CU 40. Solenoid valve 60 is air chamber 6
Controls the presence or absence of communication between the inside and the atmosphere. A pressure sensor 61 that measures the pressure inside the air chamber 6 is attached to the upper portion 2 of the fuel tank 1. The pressure sensor 61 is connected to the input port 46 via the corresponding AD converter 48.
Further, a fuel gauge 62 for detecting the position of the separation membrane 5 to detect the amount of fuel in the fuel chamber is attached to the upper portion 2 of the fuel tank 1. The fuel gauge 62 is connected to the input port 46 via the corresponding AD converter 48. Also, the eighth
The fuel tank 1 of the embodiment includes a temperature sensor 55 that detects the temperature of cooling water for cooling the engine (hereinafter, engine water temperature). The temperature sensor 55 is connected to the input port 46 via the corresponding AD converter 48. Note that the configuration other than the above-described configuration of the eighth embodiment is the same as that of the second embodiment, so description will be omitted.

Next, the evaporative fuel discharge operation of the eighth embodiment will be described. In the eighth embodiment, when the engine water temperature is higher than a predetermined water temperature and the amount of fuel remaining in the fuel chamber is larger than a predetermined fuel amount, the state of the engine and the fuel tank is a state in which the evaporated fuel discharge function can be executed. It is determined to be in. The predetermined water temperature is set to the temperature when the cooling water cools the engine in the steady operation state,
The predetermined amount of fuel is set to a sufficient amount of fuel to raise the fuel level by lowering the separation membrane. On the other hand, when the conditions are other than these, it is determined that the engine or the fuel tank is in a state in which the evaporated fuel discharging operation cannot be executed.

When the level switch is off, it is determined that the evaporative fuel discharge operation needs to be executed, and when the level switch is on, it is determined that the evaporative fuel discharge operation need not be executed.

When it is determined that the state of the engine and the fuel tank is such that the evaporative fuel discharge operation can be executed and the evaporative fuel discharge operation should be executed, the solenoid valve 60 is operated.
Is closed and the pump 35 is operated to increase the pressure in the air chamber 6. Then, when the pressure in the air chamber 6 increases by a predetermined pressure, the pump 35 is stopped. The predetermined pressure is set to a pressure at which the liquid fuel level does not swell due to an increase in pressure inside the air chamber. By repeating the operation and stop of the pump 35 described above, the pressure in the air chamber 6 is increased, and the evaporated fuel discharging action is executed. Therefore, according to the eighth embodiment, the increase rate of the pressure in the air chamber is an increase rate at which the fuel liquid level does not swell.

When it is determined that the state of the engine or the fuel tank is in a state where the evaporative fuel discharge action cannot be executed, or when it is determined that it is not necessary to perform the evaporative fuel discharge action, the pump 35 is stopped. Solenoid valve 60
Open. Further, in the eighth embodiment, the pump for pressurizing the air chamber corresponds to the gas discharging means or the liquid level raising means,
The level switch or the fuel gauge corresponds to the liquid level detecting means.

FIG. 17 is a flow chart showing the evaporated fuel discharge operation in the eighth embodiment. Step S81
At 0, it is determined whether the engine water temperature T is higher than a predetermined water temperature T ₀ (T> T ₀ ). Here, the predetermined water temperature T ₀ is set to the water temperature when the engine is in an operating state in which the evaporated fuel discharged by the evaporated fuel discharging action may be discharged to the engine intake passage. When it is determined that the T> T ₀ in step S810, the process proceeds to step S812. In step S812, it is determined whether or not the level switch is off. If the level switch is off in step S812, the process proceeds to step S814.
Step amount of fuel the fuel amount F remaining in the fuel chamber reaches a predetermined in S814 (hereinafter referred to as "predetermined amount") F ₀ is greater than (F> F _0), it is determined whether. Here, the predetermined amount F ₀ is set to a fuel amount with which the separation membrane can be displaced by increasing the pressure in the air chamber. Step S81
If F> F ₀ is determined in step 4, step S
Proceed to 816. On the other hand, in step S810, T ≦ T
_If it is determined to be ₀ , the level switch is determined to be on in step S812, and F ≦ F ₀ is determined in step S814, the process proceeds to step S840 to turn on the solenoid valve. Open the valve,
Next, the process proceeds to step S842, the pump is stopped, and the process ends.

In step S816, it is determined whether or not the solenoid valve is closed. If it is determined in step S816 that the solenoid valve is closed, step S81
The process proceeds to step 8 and the predetermined pressure Δ for the previous target pressure P _n
P is added to calculate a new target pressure P _n , and step S8 is performed.
Proceed to 24. On the other hand, if it is determined in step S816 that the solenoid valve is open, the process proceeds to step S836 to close the solenoid valve, and then to step S838 to read the pressure in the air chamber with the pressure sensor and set the target pressure. P
Input to _n and finish the process.

At step S820, it is judged if the target pressure P _n is larger than the maximum pressure P _max (P _n > P _max ). If it is determined in step S820 that P _n > P _max , the maximum pressure P _max is input as the target pressure P _n, and the flow proceeds to step S824. On the other hand, step S820
If it is determined that P _n ≤P _max in step S1, step S
Proceed to 824. In step S824, the pressure P in the air chamber is
Is smaller than the maximum pressure _Pmax (P < _Pmax ). If it is determined in step S824 that P <P _max , the process proceeds to step S826. On the other hand, if it is determined in step S824 that P ≧ P _max ,
In step S832, the solenoid valve is opened, then in step S834, the pump is stopped, and the process ends.
In step S826, the pressure P in the air chamber is set to the target pressure P _n.
It is determined whether or not it is smaller than (P <P _n ). _If it is determined in step S826 that P <P _n , the process proceeds to step S828 to close the electromagnetic valve, and then step S828.
Proceed to 830 to operate the pump and end the process. On the other hand, _if it is determined in step S826 that P ≧ P _n , the process proceeds to step S834, the pump is stopped, and the process ends.

Incidentally, in the eighth embodiment, the evaporated fuel discharged from the fuel tank by the evaporated fuel discharging action is introduced into the engine intake passage. Therefore, the introduced fuel vapor reduces the air-fuel ratio of the air-fuel mixture. Therefore, the air-fuel ratio deviates from the desired air-fuel ratio. Therefore, in the ninth embodiment, the amount of evaporated fuel discharged from the fuel tank is controlled so that a desired air-fuel ratio can be obtained.

The ninth embodiment will be described with reference to the drawings.
FIG. 18 shows a fuel tank of the ninth embodiment. The fuel tank of the ninth embodiment includes an air-fuel ratio sensor 63 that generates an output voltage indicating the air-fuel ratio in the engine intake passage, in addition to the configuration of the eighth embodiment. Examples of the air-fuel ratio sensor include an O ₂ sensor whose output voltage changes according to the oxygen concentration in the exhaust gas and a linear air-fuel ratio sensor. The air-fuel ratio sensor 63 is connected to the input port 46 via the corresponding AD converter 48. Note that the configuration other than the above-described configuration of the ninth embodiment is the same as that of the eighth embodiment, so description will be omitted.

Next, the evaporative fuel discharge operation of the ninth embodiment will be described. In the ninth embodiment, when the engine water temperature is higher than the predetermined water temperature, the amount of fuel remaining in the fuel chamber is higher than the predetermined fuel amount, and the pressure in the air chamber 6 is lower than the predetermined pressure. It is determined that the state of the engine and the fuel tank 1 is in a state where the evaporative fuel discharge action can be executed. The predetermined water temperature is set to the temperature when the cooling water cools the engine in the steady operation state, and the predetermined fuel amount is sufficient to raise the fuel liquid level by lowering the separation membrane. The amount of fuel is set, and the predetermined pressure is set lower than the pressure that damages the separation membrane. On the other hand, when the conditions are other than these, it is determined that the engine or the fuel tank is in a state in which the evaporated fuel discharging operation cannot be executed.

When the level switch 57 is off, it is determined that the evaporative fuel discharge operation needs to be executed, and when the level switch 57 is on, it is determined that the evaporative fuel discharge operation need not be executed.

Further, when the air-fuel ratio detected by the air-fuel ratio sensor 63 is larger than a predetermined air-fuel ratio, it is judged that the evaporative fuel discharge action should be continued, and the air-fuel ratio sensor 6
When the air-fuel ratio detected by 3 is less than or equal to a predetermined air-fuel ratio, it is determined that the evaporated fuel discharge action should be stopped. The predetermined air-fuel ratio is set as desired.

When it is determined that the state of the engine and the fuel tank 1 is in a state where the evaporated fuel discharging operation can be executed, the evaporated fuel discharging operation needs to be executed, and the evaporated fuel discharging operation should be continued. The electromagnetic valve 60 is closed and the pump 35 is operated to increase the pressure in the air chamber 6. On the other hand, when it is determined that the state of the engine and the fuel tank 1 is in a state capable of performing the evaporated fuel discharging action, the evaporated fuel discharging action needs to be performed, and the evaporated fuel discharging action should be stopped, The pump 35 is stopped. Therefore, according to the ninth embodiment, a desired air-fuel ratio can be obtained because the amount of evaporated fuel discharged from the fuel tank is controlled.

When it is determined that the state of the engine or the fuel tank 1 is in a state where the evaporative fuel discharge action cannot be executed, or when it is determined that the evaporative fuel discharge action need not be executed, the solenoid valve 60 is turned on. Open the valve and pump 3
Stop 5 Further, in the ninth embodiment, the purging action for introducing the negative pressure in the engine intake passage into the fuel chamber corresponds to the gas discharging means or the liquid level increasing means, and the level switch or the fuel gauge corresponds to the liquid level detecting means.

FIG. 19 is a flow chart showing the evaporated fuel discharge operation in the ninth embodiment. Step S91
From 0 to step S914 is step S8 of the eighth embodiment.
Since it corresponds to 10 to step S814, description thereof will be omitted. If F> F ₀ is determined in step S914, the process proceeds to step S916. In step S916, the pressure P in the air chamber is smaller than the maximum pressure P _max (P <
P _max ). If it is determined in step S916 that P <P _max , then step S918
Proceed to.

In step S910, the water temperature is T≤T _0.
, It is determined that the level switch is ON in step S912, F ≦ F ₀ is determined in step S914, and P ≧ P _max is determined in step S916. If so, proceed to step S924 to open the solenoid valve, then proceed to step S926 to stop the pump,
The process ends.

In step S918, it is determined whether the air-fuel ratio AF detected by the air-fuel ratio sensor is larger than a predetermined air-fuel ratio AF ₀ (AF> AF ₀ ). If it is determined in step S918 that AF> AF ₀ , the process proceeds to step S920 to close the electromagnetic valve, then proceeds to step S922 to operate the pump, and ends the process. On the other hand, if it is determined in step S918 that AF ≦ AF ₀ , the process proceeds to step S926, the pump is stopped, and the process ends.

By the way, in the third and seventh embodiments, refueling is executed in a state where the pressure in the air chamber is increased. Therefore, the fuel in the fuel chamber may flow back into the fuel injection pipe due to the increased pressure in the air chamber when refueling is completed. Therefore, in the tenth embodiment, the backflow of fuel from the fuel chamber into the fuel injection pipe after refueling is prevented.

The tenth embodiment will be described with reference to the drawings. FIG. 20 shows a fuel tank of the tenth embodiment. First
In the 0th embodiment, in addition to the configuration of the 7th embodiment, a fuel gauge 62 that detects the position of the separation membrane 5 and detects the fuel amount in the fuel chamber is attached to the upper portion 2 of the fuel tank 1.
The fuel gauge 62 is a pendulum type gauge, one end of which is located at the center of the separation membrane 5, and a voltage is generated at the other end according to the swing angle (liquid level position) of the pendulum, and the voltage corresponds to that. Input port 46 via AD converter 48
Entered in. The configuration other than the above-described configuration of the tenth embodiment is the same as that of the seventh embodiment, and thus the description thereof will be omitted.

Next, the evaporative fuel discharge action of the tenth embodiment will be described. The evaporative fuel discharge action until the opening of the cap lid is permitted is similar to that of the seventh embodiment, and therefore the description thereof is omitted. In the tenth embodiment, when the opening of the cap lid is permitted, refueling is executed until the fuel chamber 7 becomes full. When a predetermined waiting time elapses after the fuel gauge 62 detects that the fuel chamber 7 is filled with fuel, the solenoid valve 60 is opened to open the air chamber 6
Reduce the pressure inside. The predetermined standby time is the time from when it is detected that the fuel in the fuel chamber is full and when the refueling from the refueling nozzle is actually stopped. Therefore, according to the tenth embodiment, the pressure in the air chamber is reduced when refueling from the refueling nozzle is stopped, so that backflow of fuel from the fuel chamber into the fuel injection pipe after refueling is prevented. In the tenth embodiment, the pump that pressurizes the air chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch or the fuel gauge corresponds to the liquid level detecting means.

21 and 22 are flowcharts showing the evaporative fuel discharge operation in the tenth embodiment.
In step S1010, it is determined whether the cap lid opener switch 50 is on. Step S1010
When it is determined that the switch 50 is on in step S1012, the process proceeds to step S1012. On the other hand, when it is determined that the switch 50 is off in step S1010,
2 to step S1050 to set the end flag, then to step S1052 to stop the pump,
Next, proceeding to step S1054, the solenoid valve is opened, and then proceeding to step S1056. The end flag is set when the switch 50 is turned off and when the counter exceeds a predetermined standby time, and is reset when the refueling is ended.

In step S1012, it is determined whether the level switch is on. If it is determined in step S1012 that the level switch is off, the process proceeds to step S1014. On the other hand, if it is determined in step S1012 that the level switch is on, then in step S102.
4, the second refueling flag is set, and then step S
1026 to stop the pump, then step S10
28, the solenoid valve is opened, and then step S1030
To permit opening of the cap lid, and then step S1
Proceed to 032. The second refueling flag is set when the level switch is turned on once and refueling is permitted, and is reset when refueling is completed.

In step S1014, the pressure P detected by the pressure sensor is smaller than the predetermined pressure P _max (P <P
_max ) is determined. If it is determined that P <P _max in step S1014, step S101
Go to 6. On the other hand, in step S1014, P ≧ P
_If it is determined to be _max , the flow proceeds to step S1022, the first refueling flag is set, and then step S1026.
To stop the pump, then to step S1028 to open the solenoid valve, then to step S1030 to permit opening of the cap lid, and then to step S1032. The first refueling flag is set when the pressure in the air chamber once exceeds a predetermined pressure to permit opening of the cap lid, and is reset when refueling is completed.

At step S1016, it is judged if the first refueling flag is reset. Step S1
When it is determined in 016 that the refueling flag is reset, the process proceeds to step S1018 to close the electromagnetic valve, and then proceeds to step S1020 to operate the pump,
The process ends. On the other hand, when it is determined in step S1016 that the refueling flag is set, the process proceeds to step S1026 to stop the pump, and then step S1.
028 to open the solenoid valve, then step S103
Go to 0 to allow opening of the cap lid, then step S
Proceed to 1032.

In step S1032, it is determined whether the counter flag has been reset. Step S1
If it is determined in 032 that the counter flag is reset, the process proceeds to step S1034. On the other hand, when it is determined in step S1032 that the counter flag is set, the process proceeds to step S1042 in FIG.

In step S1034, the fuel is full (F
It is determined whether or not Step S103
If it is determined in step 4 that the fuel is full, the flow advances to step S1036 to set the counter to "0", and then to step S1038 to set the counter flag,
The process ends. The counter flag is set when the fuel is full, and reset when refueling is completed.

In step S1040 of FIG. 22, it is judged if the second refueling flag is set. If it is determined in step S1040 that the second refueling flag is set, the process ends. On the other hand, step S
If it is determined at 1040 that the second refueling flag has been reset, the process proceeds to step S1044.

At step S1042, it is judged if the counter t is shorter than a predetermined waiting time t ₀ (t <t ₀ ). If it is determined that t <t ₀ in step S1042, the process advances to step S1043, t + 1 is input to the counter t, and the process advances to step S1044. On the other hand, if it is determined in step S1042 that t ≧ t ₀ , the process proceeds to step S1050 to set an end flag, then proceeds to step S1052 to stop the pump, and then proceeds to step S1054 to turn on the solenoid valve. Open the valve,
Then, the process proceeds to step S1056.

In step S1044, the pressure sensor is detected.
The second pressure P in which the pressure P is predetermined ₂Less than (P <
P₂) Is determined. Smell in step S1044
P <P₂If it is determined that it is, step S1046
To close the solenoid valve, and then to step S1048.
Then the pump is activated and the process is completed. Meanwhile, step
In S1044, P ≧ P₂If it is determined that
Proceed to step S1052 to stop pump, then step.
Go to step S1054 to open the solenoid valve, and then step S10
Proceed to 56.

In step S1056, it is determined whether the end flag is set. Step S1056
When it is determined that the end flag is set in step S1058, the first refueling flag is reset, the process proceeds to step S1060, the second refueling flag is reset, and the process proceeds to step S1062. The flag is reset, then step S106
In step 4, the end flag is reset and the process ends.

By the way, in the first to tenth embodiments, the fuel pump is housed in the fuel tank. Since the outer shape of the fuel pump is complicated, the separation membrane cannot be brought into close contact with the fuel liquid surface around the fuel pump. Therefore, a space is formed between the separation membrane and the fuel liquid surface in the vicinity of the fuel pump. Therefore, in the eleventh embodiment, the first
The possibility of forming a space between the separation membrane and the fuel liquid surface is reduced as compared with the embodiments to the tenth embodiment.

The eleventh embodiment will be described with reference to the drawings. FIG. 23 shows a fuel tank of the eleventh embodiment. First
In the first embodiment, the fuel pump 19 arranged in the fuel tank of the fourth embodiment is arranged outside the fuel tank 1. The fuel pump 19 is connected to the oil filter 21 through the lower portion 3 of the fuel injection pipe 13 via the fuel pump pipe 19a. The return passage 64 branches from the fuel pressure regulator 20 arranged on the downstream side of the fuel pump 19. The return passage 64 serves to return excess fuel into the fuel tank 1. Since the fuel pump 19 is arranged outside the fuel tank 1 in the eleventh embodiment, the fuel pump chamber is excluded. Therefore, the evaporative fuel discharge pipe connected to the fuel pump chamber is eliminated. Further, the level switch 57 is attached to the side wall of the lower portion 3 near the fixed portion 8. Note that the configuration other than the above-described configuration of the eleventh embodiment is the same as that of the fourth embodiment, so description will be omitted. Further, the evaporative fuel discharging action of the eleventh embodiment is the same as that of the fourth embodiment, so description thereof will be omitted.

Therefore, according to the eleventh embodiment, since the fuel pump is arranged outside, the structure inside the fuel tank is simplified and the possibility that a space is formed between the separation membrane and the liquid surface of the fuel is reduced. In addition to the fourth embodiment, the evaporative fuel discharge operation of other embodiments can be applied to the fuel tank of the eleventh embodiment. Further, in the eleventh embodiment, the purging action for introducing the negative pressure in the engine intake passage into the fuel chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch corresponds to the liquid level detecting means.

By the way, in the first embodiment, fuel remains in the fuel injection pipe after refueling. Evaporated fuel is generated from the fuel remaining in the fuel injection pipe. Therefore, in the twelfth embodiment, generation of evaporated fuel from the fuel in the fuel injection pipe is suppressed.

The twelfth embodiment will be described with reference to the drawings. FIG. 24 shows a fuel tank of the twelfth embodiment. First
In the second embodiment, the opening of the fuel injection pipe 13 into the fuel chamber 7 in the first embodiment is attached to the fixed portion 8. Further, the fuel injection pipe 13 is arranged at a position higher than the opening. With this configuration, as the fuel in the fuel chamber is consumed, the fuel in the fuel injection pipe flows into the fuel chamber by its own weight. Therefore, according to the twelfth embodiment, the fuel is removed from the fuel injection pipe, so that the generation of evaporated fuel in the fuel injection pipe can be suppressed. The structure of the twelfth embodiment other than the above-described structure is the same as that of the first embodiment, and thus the description thereof is omitted. Further, the evaporative fuel discharging action of the twelfth embodiment is the same as that of the first embodiment, and therefore its explanation is omitted. In addition, it is also possible to apply the evaporative fuel discharge action of other embodiments than the first embodiment to the fuel tank of the twelfth embodiment. Further, in the twelfth embodiment, refueling corresponds to the liquid level raising means. More preferably, the opening of the fuel injection pipe may be arranged higher than the maximum height position in the fuel tank. In this case, the fuel in the fuel injection pipe is completely removed.

By the way, in the twelfth embodiment, when the fuel in the fuel chamber is consumed, the fuel in the fuel injection pipe flows into the fuel chamber. Therefore, it takes time for the fuel in the fuel injection pipe to completely flow into the fuel chamber. Therefore, evaporated fuel is generated in the fuel injection pipe. Therefore, in the thirteenth embodiment, the evaporated fuel generated from the fuel in the fuel injection pipe is further suppressed as compared with the twelfth embodiment.

A thirteenth embodiment will be described with reference to the drawings. FIG. 25 shows a fuel tank of the thirteenth embodiment. First
The air chamber 6 of the third embodiment is the air communication pipe 3 of the twelfth embodiment.
Instead of 3, it is connected to the pump 35 via the first connecting pipe 34. The first connecting pipe 34 is connected to the solenoid valve 60 via the second connecting pipe 36. Solenoid valve 60 corresponds to drive circuit 4
9 to the output port 47. The solenoid valve 60 is controlled to be opened / closed by the ECU 40. Also, the fuel tank 1
A pressure sensor 61 for measuring the pressure in the air chamber 6 is attached to the upper portion 2 of the. The pressure sensor 61 corresponds to A
It is connected to the input port via the D converter 48. Further, a fuel gauge 62 for detecting the position of the separation membrane 5 and detecting the amount of fuel in the fuel chamber is attached to the upper portion 2 of the fuel tank 1. The fuel gauge 62 is connected to the input port 46 via the corresponding AD converter 48. The configuration other than the above-described configuration of the thirteenth embodiment is the same as that of the twelfth embodiment, and the description thereof will be omitted.

Next, the evaporative fuel discharge operation of the thirteenth embodiment will be described. No. 10 until opening of the cap lid is permitted
The description is omitted because it is similar to the embodiment. When the cap lid is opened, the fuel chamber is full.
Refueling is executed until. When a predetermined waiting time elapses after the fuel gauge 62 detects that the fuel chamber is full of fuel, the solenoid valve 60 is opened to reduce the pressure in the air chamber 6. Here, the predetermined standby time is the time from when it is detected that the fuel in the fuel chamber is full and immediately after the refueling from the refueling nozzle is actually stopped. Therefore, according to the thirteenth embodiment, when the refueling from the refueling nozzle is stopped and a predetermined time elapses, the pressure in the air chamber is reduced, and the fuel in the fuel injection pipe flows into the fuel chamber. 1
Evaporative fuel generated from the fuel in the fuel injection pipe is further suppressed as compared with the second embodiment. In the thirteenth embodiment, the pump for pressurizing the air chamber corresponds to the gas discharging means or the liquid level raising means, and the level switch or the fuel gauge corresponds to the liquid level detecting means.

26 and 27 are flowcharts showing the evaporated fuel discharge operation in the thirteenth embodiment.
Steps S1310 to S1 of the thirteenth embodiment
Since 360 is the same as steps S1010 to S1060 of the tenth embodiment except step S1342, the description thereof will be omitted. Step S1 of the thirteenth embodiment
At 342, it is judged if the counter t is shorter than a predetermined waiting time t ₁ (t <t ₁ ). Step S
If it is determined that t <t ₁ in 1342, the flow advances to step S1343 to input t + 1 into the counter t,
It proceeds to step S1344. On the other hand, step S1342
If it is determined that t ≧ t ₁ in step S1, step S1
Proceed to 350 to set the end flag, then step S
Proceed to 1352 to stop pump, then step S13
54, the solenoid valve is opened, and then step S1356.
Proceed to.

In the above embodiment, whether the relief valve is opened or closed, the pressure in the air chamber, or the level is used as a condition for determining whether to operate the pump or a condition for determining whether to open the solenoid valve. It uses whether or not the switch is on. However, it is also possible to provide a detection means for detecting the position of the separation membrane in the fuel tank, and determine whether or not the separation membrane is displaced by the operation of the pump, as a determination condition.

Next, the overall structure of the fuel tank (fuel storage device) of the fourteenth embodiment of the present invention will be described. As shown in FIG. 28, the fuel tank of the fourteenth embodiment includes a fuel tank body 140. The fuel tank body 140 is composed of a generally bowl-shaped upper portion 91 and a lower portion 92. The upper portion 91 and the lower portion 92 are the flange portions 91.
a and 92a are connected to each other. A fuel chamber 9 for accommodating and storing fuel in the fuel tank body 140.
A fuel container 94, which forms 3, is housed. Fuel container 94
Is a rigid but deformable generally rectangular upper wall 95,
A generally rectangular lower wall 96 that is also rigid but deformable
And a strip-shaped wall (coupling wall) 97 that has rigidity but is deformable and connects the peripheral edge portion 95a of the upper wall 95 and the peripheral edge portion 96a of the lower wall 96 to each other (see FIG. 29). Therefore, the upper wall 95, the lower wall 96, and the band-shaped wall 97 correspond to the membrane wall that forms the fuel chamber inside the fuel tank.

In the fourteenth embodiment, when the amount of fuel in the fuel container 94 increases, the upper wall 95 and the lower wall 96 are deformed so as to bulge outward, and the connecting wall 97 is curved inward accordingly. The internal volume of the fuel container 94 increases (FIG. 30).
reference). On the other hand, when the amount of fuel in the fuel container 94 decreases, the upper wall 95 and the lower wall 96 that have bulged outward and the connecting wall 97 that has curved inwardly return to their original shape, and the fuel container 94
The internal volume of the inside decreases. Further, when the amount of fuel in the fuel container 94 decreases, the upper wall 95 and the lower wall 96 respectively deform so as to be recessed inward, and accordingly, the connecting wall 97 curves inward, and the internal volume of the fuel container 94 decreases. (See FIG. 31). The rigidity of the connecting wall 97 is determined by the upper wall 95 and the lower wall 9.
Higher than 6 rigidity.

A fuel inlet / outlet opening 98 is formed in the central portion of the lower wall 96 of the fuel container 94. Also, the fuel tank body 1
A connection pipe opening 99 is formed in the central portion of the lower portion 92 of the 40. The fuel container 94 is arranged in the fuel tank body 140 so that the fuel inlet / outlet opening 98 is aligned with the connecting pipe opening 99.

An air chamber 110 is formed outside the fuel container 94 and inside the fuel tank body 140. On the inner wall surface of the upper portion 91 of the fuel tank body 140, the fuel container 9
Of the upper wall 95 of the fuel container 94
A fuel amount detection device 111 for calculating the amount of fuel inside is attached. Further, an air inlet / outlet opening 112 is provided in the upper portion 91 of the fuel tank body 140. As the amount of fuel in the fuel container 94 changes and the inner volume of the fuel container 94 increases and decreases, the inner volume of the air chamber 110 increases and decreases. At this time, air enters and exits through the air entry / exit opening 112. As a result, the fuel container 94 is easily deformed. Also,
A filter 11 for preventing foreign matters other than air from entering the air chamber 110 into the air inlet / outlet opening 112.
3 is inserted.

A fuel inlet / outlet opening 98 of the fuel container 94 and a connecting pipe opening 99 of the lower portion 92 of the fuel tank body 140.
One end of a fuel pipe 114 for introducing the fuel into the fuel container 94 and taking out the fuel from the fuel container 94 is inserted into and connected to this. On the other hand, the other end of the fuel pipe 114 is a lower end of a fuel supply pipe 115 for supplying the fuel into the fuel container 94 and one end of a fuel introduction pipe 117 for introducing the fuel from the fuel container 94 into the fuel pump device 116. Connected to. The other end of the fuel introduction pipe 117 is connected to the fuel pump device 116.

The fuel pump device 116 draws up the fuel in the fuel container 94 and sends it to the fuel injection valve (not shown) of the internal combustion engine. The fuel pump device 116 has a pump fuel vapor pipe 1 for discharging the fuel vapor from the fuel pump device 116.
One end of 18 is connected. The other end of the evaporated fuel pipe 118 is connected to the fuel supply pipe 115 near the upper opening 119 of the fuel supply pipe 115. Further, one end of a fuel feed pipe 120 for feeding fuel from the fuel pump device 116 to the fuel injection valve is connected to the fuel pump device 116.

On the upper wall 95 of the fuel container 94, a container evaporated fuel pipe 150 for discharging the evaporated fuel from the fuel container 94.
One end of is connected. The other end of the evaporated fuel pipe 150 is connected to the fuel pump device 116. Also, the evaporated fuel pipe 150
Evaporative fuel pipe cutoff valve (or container sealing valve) 1 at one end
49 is attached. The shutoff valve 149 includes a float 151 having a density lower than that of the fuel. The opening of the evaporated fuel pipe 150 that opens in the fuel container 94 corresponds to the communication port that opens in the space above the fuel liquid level, and the shutoff valve 149 corresponds to the shutoff valve that shuts off this communication port.

One end of a supply pipe evaporated fuel pipe 121 for discharging evaporated fuel from the vicinity of the upper opening 119 is connected to the fuel supply pipe 115 on the upper opening 119 side from the other end of the pump evaporated fuel pipe 118. The other end of the evaporated fuel pipe 121 is connected to a canister 122 for temporarily adsorbing and holding evaporated fuel.

Activated carbon 123 for adsorbing the evaporated fuel is arranged in the canister 122. Canister 122
The internal space of is divided by activated carbon 123. Therefore, the evaporated fuel chamber 124 is formed on one side of the activated carbon 123, and the air chamber 125 is formed on the other side of the activated carbon 123. The other end of the supply fuel vapor fuel pipe 121 is connected to a fuel vapor chamber 124 in the canister 122. Further, one end of a canister evaporated fuel pipe 126 for discharging the evaporated fuel adsorbed by the activated carbon 123 from the canister 122 to the intake passage 127 of the internal combustion engine is connected to the evaporated fuel chamber 124. The other end of the evaporated fuel pipe 126 has an intake passage 127.
Of the surge tank 128.

An evaporated fuel amount control valve (hereinafter, also simply referred to as “control valve”) 129 for opening and closing the evaporated fuel pipe 126 is attached to the canister evaporated fuel pipe 126. The control valve 129 is opened / closed by a control device (not shown). One end of an air tube 130 for introducing air into the air chamber 125 is connected to the air chamber 125 of the canister 122. The other end of the air pipe 130 is connected to the air cleaner 131 of the intake passage 127. A cutoff valve 132 for opening and closing the air pipe 130 is arranged in the air pipe 130. The shutoff valve 132 is controlled to be opened and closed by a control device (not shown). A throttle valve 133 for controlling the amount of air supplied to the engine body 180 is arranged in the intake passage 127.

In the fourteenth embodiment, when the evaporated fuel in the canister 122 should be introduced into the intake passage 127, the control valve 1
29 is opened. The shutoff valve 132 is normally opened. Therefore, when the control valve 129 is opened, the negative pressure in the surge tank 128 is introduced into the canister 122 via the canister evaporated fuel pipe 126, and the air in the air cleaner 131 is changed to the air pipe 1.
It is introduced into the canister 122 via 30. In this way, the evaporated fuel in the canister 122 is introduced into the intake passage 127. The control valve 129 is controlled to be opened / closed in accordance with the engine operating state so that an amount of evaporated fuel that can obtain a desired air-fuel ratio is introduced into the intake passage 127. Therefore, the control valve 129 of the present embodiment corresponds to the evaporated fuel amount control means for controlling the amount of evaporated fuel released into the intake passage 127, and the shutoff valve 132 of the present embodiment determines whether or not air is introduced into the canister 122. Corresponds to an air amount control means for controlling.

Further, in the fourteenth embodiment, the canister 12
When a leak in the fuel system communicating with 2 is to be detected, a negative pressure is introduced into the fuel system from the canister 122 to the fuel tank body 140, and then the control valve 129 and the shutoff valve 132 are closed. As a result, the fuel system communicating with the canister 122 is sealed. After that, when it is detected by the pressure sensor (not shown) that the pressure in the fuel system tends to increase toward the atmospheric pressure, it is determined that there is a leak portion in the fuel system. Therefore, the control valve 129 and the shutoff valve 132 of the present embodiment correspond to the fuel leak detection means.

Next, a fuel pump device according to a fourteenth embodiment of the present invention will be described in detail with reference to FIGS. 32 and 33.
As shown in FIG. 32, the fuel pump device 116 of the fourteenth embodiment has a pump chamber 153 defined by a housing 152. The pump chamber 153 is divided into a pump chamber portion 155 and a sub-tank chamber 156 by a pump chamber partition wall (hereinafter, also simply referred to as “partition wall”) 154. Partition wall 15
Reference numeral 4 denotes a vertical wall 154a extending substantially vertically from the inner wall surface of the upper wall of the housing 152, and a horizontal wall 154b horizontally extending above the inner wall surface of the lower wall of the housing 152 to the inner wall surface of the side wall of the housing 152. And. A pump evaporative fuel pipe 1 for discharging evaporative fuel from the pump chamber portion 155 is provided on the upper wall of the housing 152.
The one end of 18 is connected. Evaporative fuel pipe for pump 11
An opening at one end of 8 opens near the upper wall of the housing 152 in the pump chamber portion 155.

A fuel pump 157 for delivering fuel from the sub tank chamber 156 to the fuel injection valve via the fuel feed pipe 120 is arranged in the sub tank chamber 156.
The lower wall of the fuel pump 157 has a first fuel filter 158 for filtering the fuel sucked into the fuel pump 157.
Are connected. Further, a pressure adjusting device 159 for adjusting the pressure of the fuel is attached to the fuel feed pipe 120 in the sub tank chamber 156. An upper end portion of a fuel return pipe 161 for returning a part of the fuel delivered by the fuel pump 157 to the sub tank chamber 156 is connected to the pressure adjusting device 159. Further, the fuel pump 1 is connected to the fuel feed pipe 120 between the pressure adjusting device 159 and the fuel pump 157.
A second fuel filter 160 for filtering the fuel delivered from 57 is attached.

The lower tip portion 162 of the fuel return pipe 161 is oriented substantially in the horizontal direction, and has a tapered shape in which the diameter becomes smaller toward the tip. The lower tip portion 162 is housed in a negative pressure generating housing 163 for generating a negative pressure by the return fuel or the reflux fuel. The negative pressure generating housing 163 includes a trumpet-shaped fuel discharge pipe 164 whose diameter increases toward the tip. The fuel discharge pipe 164 is arranged so as to be aligned with the lower tip portion 162. Further, in the negative pressure generating housing 163, the container evaporated fuel pipe 150 is provided.
The lower end of is accommodated.

In the sub-tank chamber 156, the container evaporative fuel pipe 150 is provided with a sub-tank chamber negative pressure introducing pipe (hereinafter simply referred to as “negative pressure passage inlet pipe”) 165 for introducing a negative pressure into the sub-tank chamber 156. To do. The negative pressure introducing pipe 165 is provided in the region above the sub tank chamber 156.
Open in 56. The diameter of the negative pressure introducing pipe 165 is smaller than the diameter of the container evaporated fuel pipe 150.

A vertical annular wall 167 extending vertically downward from the horizontal wall 154b is attached to the horizontal wall 154b of the pump chamber partition wall 154. The vertical annular wall 167 is a fuel inflow passage 1 for injecting fuel into the sub tank chamber 156.
66 is formed. The upper opening of the fuel inflow passage 166 is located at a position lower than the bottom wall surface of the fuel introduction pipe 117. At the lower end of the vertical annular wall 167, a horizontal annular wall 168 extending horizontally from the vertical annular wall 167 toward the fuel discharge pipe 164.
Is attached. The horizontal annular wall 168 is the fuel discharge pipe 16
Fuel passage passage 169 for passing fuel discharged from No. 4
To form.

Vertical annular wall 167 and pump chamber portion 15
A mesh-shaped partition wall (hereinafter, also simply referred to as “partition wall”) 170 for separating gas from fuel is arranged in the container 5.
The partition wall 170 extends upward from the bottom wall surface of the horizontal annular wall 168 into the fuel inflow passage 166. Therefore, the partition 170 traverses the fuel passage passage 169. Further, the partition 170 extends through the vertical annular wall 167 and into the pump chamber portion 155. The side end of the partition 170 in the vertical annular wall 167 extends to the inner wall surface of the vertical annular wall 167. Therefore the partition 1
Reference numeral 70 divides the fuel inflow passage 166 into two. Further partition 1
70 extends beyond horizontal wall 154b and into pump chamber portion 155. The upper end of the partition 170 in the pump chamber portion 155 extends to a position higher than the fuel introduction pipe 117. Also,
Both ends of the partition 170 in the pump chamber portion 155 are connected to the inner wall surface of the cylindrical wall of the housing 152. Further, the lower end of the partition wall 170 in the pump chamber portion 155 has the horizontal wall 1
54b.

Next, the operation of the fuel pump system according to the fourteenth embodiment of the present invention will be described. When the fuel pump 157 is operated to supply the fuel in the fuel container 94 to the fuel injection valve, the fuel in the sub tank chamber 156 is sucked into the fuel pump 157 via the first fuel filter 158. The fuel sucked into the fuel pump 157 is sent to the pressure adjusting device 159 via the second fuel filter 160. When the pressure of the fuel in the pressure adjusting device 159 is higher than a predetermined pressure, a part of the fuel is returned to the sub tank chamber 156 via the fuel return pipe 161. Therefore, the pressure adjusting device 159 and the fuel return pipe 161 function as fuel recirculation means. Thereby, the pressure of the fuel supplied to the fuel injection valve is maintained at a predetermined pressure. The remaining fuel having a predetermined pressure is supplied to the fuel injection valve via the fuel feed pipe 120.

The sub tank chamber 1 via the fuel return pipe 161.
The fuel returned into 56 is discharged into the negative pressure generating housing 163 from the lower tip portion 162. Lower tip 162
Since V is tapered, the flow velocity of the fuel discharged from the lower tip 162 is increased by the Venturi effect. The fuel whose flow velocity has been increased is the fuel discharge pipe 1
It flows into the fuel passage 169 via 64.

When the fuel is increased in flow velocity and discharged from the lower tip portion 162 to the fuel discharge pipe 164, a negative pressure is generated in the negative pressure generating housing 163. Therefore, the fuel return pipe 161 and the negative pressure generating housing 163 of this embodiment correspond to negative pressure generating means. The negative pressure generated in the negative pressure generating housing 163 is transferred to the space above the liquid surface of the fuel in the fuel container 94 via the container evaporative fuel pipe 150, and the container evaporative fuel pipe 150 and the negative pressure introducing pipe. It is introduced into the space above the fuel liquid level in the sub tank chamber 156 via 165. Therefore, the container evaporated fuel pipe 150 and the negative pressure introducing pipe 165 correspond to a negative pressure introducing passage or a negative pressure introducing means.

In the fourteenth embodiment, the diameter of the negative pressure introduction pipe 165 is smaller than the diameter of the container evaporated fuel pipe 150. Therefore, the negative pressure is preferentially introduced into the fuel container 94, and vaporized fuel and gas such as air are preferentially discharged from the fuel container 94. Therefore, the negative pressure introducing pipe 165 of the present embodiment corresponds to a gas discharge promoting unit that preferentially discharges the gas in the fuel container 94.

When a negative pressure is introduced into the fuel container 94, the evaporated fuel and air are discharged from the fuel container 94 into the negative pressure generating housing 163. As a result, the fuel liquid level in the fuel container 94 is changed to the fuel chamber 93. It can be raised to the highest position in the area. Therefore, the fuel pump 157 of the fourteenth embodiment corresponds to the liquid level raising means. Thus, in the fourteenth embodiment,
Once the vaporized fuel and gas, such as air, have been completely evacuated from the fuel container 94 by negative pressure, the fuel container 94 is maintained free of gas in the fuel container 94 as long as the fuel pump 157 is operating. It Also,
When the fuel container 94 is maintained in a gas-free state, the upper surface of the fuel container 94 accurately indicates the amount of fuel in the fuel container 94. Therefore, according to the fourteenth embodiment, the amount of fuel in the fuel container 94 is accurately detected.

After the evaporative fuel and the air are completely removed from the fuel container 94, if the negative pressure is continuously introduced, the fuel container 94
The fuel inside leaks into the container evaporated fuel pipe 150. Therefore, the introduction of the negative pressure should be stopped when the evaporated fuel and the air are completely removed from the fuel container 94. In the fourteenth embodiment, the evaporated fuel and air are the fuel container 94.
When the fuel liquid level in the fuel container 94 reaches the evaporative fuel pipe cutoff valve 149 after being completely removed from the evaporated fuel pipe shutoff valve 1
49 shuts off the vaporized fuel pipe 150 for the container. Therefore, the evaporative fuel pipe cutoff valve 149 of this embodiment corresponds to a negative pressure introduction stopping means for stopping the introduction of the negative pressure into the fuel container 94 by the negative pressure introducing means when the gas is completely removed from the fuel container 94. To do. Further, the evaporative fuel pipe cutoff valve 1 of the present embodiment
Reference numeral 49 corresponds to a fuel leakage prevention means for preventing fuel from leaking out of the fuel container 94. After the evaporated fuel pipe cutoff valve 149 shuts off the container evaporated fuel pipe 150, the negative pressure is introduced only into the space above the fuel level in the sub tank chamber 156.

When the negative pressure is introduced into the space above the fuel liquid level in the sub tank chamber 156, the evaporated fuel and the air are discharged from the above space into the negative pressure generating housing 163. Due to this negative pressure, the fuel liquid level in the sub tank chamber 156 is raised, and the fuel flows from the pump chamber portion 155 to the fuel inflow passage 1
It is introduced into the sub tank chamber 156 via 66. In this way, the fuel liquid level in the sub tank chamber 156 is the pump chamber portion 15
Maintained at a predetermined height as long as fuel in 5 is present. Therefore, if the fuel pump device 116 is tilted and the fuel level in the sub tank chamber 156 is tilted, the fuel around the first fuel filter 158 that introduces the fuel into the fuel pump 157 is prevented from being exhausted. To be done. Therefore, the fuel return pipe 161 and the negative pressure generating housing 163 of the present embodiment correspond to the fuel depletion prevention means.

The evaporated fuel and air discharged from the space above the fuel liquid level in the fuel container 94 and the space above the fuel liquid level in the sub tank chamber 156 are the negative pressure generating housing 16.
Mixed with the fuel in the fuel cell 3 and the fuel discharge pipe 164 together with the fuel.
The fuel is discharged to the fuel passage passage 169 via. The fuel discharged to the fuel passage passage 169 passes through the lower opening of the fuel inflow passage 166. At this time, the evaporated fuel and air contained in the fuel move upward because they are lighter than the fuel, and flow from the sub tank chamber 156 to the pump chamber portion 15 via one of the fuel inflow passages 166 divided by the mesh partition 170.
It is discharged to 5. As described above, the fuel inflow passage 166 of the fourteenth embodiment has both functions of a fuel introduction passage for introducing fuel into the sub tank chamber 156 and an evaporated fuel discharge passage for discharging evaporated fuel from the sub tank chamber 156. Therefore, according to the fourteenth embodiment, it is not necessary to separately provide an evaporated fuel discharge passage other than the fuel introduction passage for introducing the fuel into the sub tank chamber 156. By thus forming the fuel introduction passage and the evaporated fuel discharge passage as one passage, the entire fuel pump device can be downsized.

Furthermore, in the fourteenth embodiment, the fuel passage 1
The fuel discharged to 69 passes through the mesh partition 170 when passing through the lower opening of the fuel inflow passage 166. Therefore, the evaporated fuel and air contained in the fuel are separated by the partition wall 1.
It is separated by 70 and discharged from the fuel inflow passage 166 to the pump chamber portion 155. Therefore, the partition wall 170 of the present embodiment corresponds to a gas separation means for separating gas from fuel.

In the fourteenth embodiment, the fuel passage 16
9 and the fuel inflow passage 166 are directly connected,
The fuel passage passage 169 is arranged substantially perpendicular to the fuel inflow passage 166. Therefore, the evaporated fuel and the air are properly separated from the fuel in the fuel inflow passage 166.
Therefore, the fuel passage passage 169 and the fuel inflow passage 166 of this embodiment correspond to a gas separation means or a gas discharge means.

The vaporized fuel discharged into the pump chamber portion 155 passes through the vaporized fuel pipe for pump 118 and the canister 122.
Will be introduced to. In the fourteenth embodiment, the lower opening of the pump evaporated fuel pipe 118 opens into the pump chamber portion 155 near the upper wall of the housing 152. Therefore, the evaporated fuel in the pump chamber portion 155 is introduced into the canister 122 until the evaporated fuel amount in the pump chamber portion 155 becomes extremely small.

By the way, the fuel in the sub tank chamber 156 is heated by the heat of the fuel pump 157. Therefore, the temperature of the fuel in the sub-tank chamber 156 will be
Higher than the temperature of the fuel inside. If this relatively high temperature fuel mixes with the relatively low temperature fuel in the pump chamber portion 155, a large amount of evaporated fuel may be generated. Further, if the fuel flows out from the sub tank chamber 156 to the pump chamber portion 155 when the amount of fuel in the sub tank chamber 156 is small, the fuel around the first fuel filter 158 may be exhausted.
Therefore, fuel should be prevented from flowing out of the sub tank chamber 156 to the pump chamber portion 155. In the fourteenth embodiment, since the fuel passage passage 169 is arranged perpendicular to the fuel inflow passage 166, the fuel passage passage 169 is formed.
It is possible to prevent the fuel discharged from the tank from flowing out to the pump chamber portion 155. Therefore, the fuel passage passage 169 and the fuel inflow passage 166 of this embodiment are the fuel outflow prevention means,
It corresponds to the evaporated fuel generation preventing means or the fuel depletion preventing means.

As the fuel is supplied from the fuel pump device 116 to the fuel injection valve, the fuel in the fuel container 94 is introduced into the pump chamber portion 155 through the fuel introduction pipe 117.
A part of the fuel introduced into the pump chamber portion 155 from the fuel introduction pipe 117 passes through the mesh partition 170. Therefore, the evaporated fuel and the air contained in the fuel in the fuel container 94 are separated in the pump chamber portion 155.

By the way, in the fourteenth embodiment, the fuel introducing pipe 117 is located lower than the lower wall 96 of the fuel container 94. Therefore, all the fuel in the fuel container 94 can be introduced into the pump chamber portion 155. Further, the upper opening of the fuel inflow passage 166 is located at a position lower than the bottom wall surface of the pipe wall of the fuel introduction pipe 117. Therefore, all the fuel in the pump chamber portion 155 can be introduced into the sub tank chamber 156. Therefore, even when the amount of fuel in the fuel container 94 is low, the fuel in the fuel container 94 will not be discharged due to the height difference between the fuel container 94 and the fuel introduction pipe 117.
It is made to flow into 6.

By the way, when the fuel tank device 116 is tilted, the inside of the pump chamber portion 155 or the fuel inflow passage 166 is formed.
The liquid level inside may reach the lower end of the fuel inflow passage 166. The fuel in the sub tank chamber 156 has a pump chamber portion when the fuel liquid level reaches the lower end of the fuel inflow passage 166 and the fuel liquid level reaches above the lowermost upper end of the fuel inflow passage 166. It flows to 155.
As described above, if the fuel in the sub tank chamber 156 flows out to the pump chamber portion 155, evaporated fuel may be generated in the pump chamber portion 155. Sub tank room 15
When the amount of fuel in 6 is small, the fuel is sub tank chamber 1
Outflow from 56 to the pump chamber portion 155 may deplete the fuel around the first fuel filter 158. 14th
In the embodiment, the vertical annular wall 167 extends downwardly from the horizontal wall 154b over a relatively long distance. Therefore, it is possible to prevent the fuel liquid level from reaching the lower end of the vertical annular wall 167 and the fuel liquid level from reaching the uppermost lower end of the upper ends of the vertical annular wall 167. Therefore, the vertical annular wall 167 extending downward from the horizontal wall 154b of the present embodiment corresponds to the fuel outflow suppressing means or the evaporated fuel generation suppressing means.

The presence or absence of the fuel outflow suppressing effect in the fourteenth embodiment depends on the length and size of the fuel inflow passage 166 (positional relation between the upper end and the lower end of the passage for introducing fuel) and the fuel tank device 116. It is determined only by the inclination angle of the fuel liquid level in the fuel inflow passage 166 when the fuel is inclined. That is, the fuel inflow passage 166 is not related to the position where the fuel inflow passage 166 is provided.
The degree of freedom in selecting the position where 66 is provided is increased.

Further, in order to better separate the gas from the fuel discharged from the fuel passage, it is desirable that the fuel discharged from the fuel passage be located below the fuel inflow passage for a long time. Therefore, as shown in FIG. 34, the fuel passage is connected downward to the fuel inflow passage so that the fuel discharged from the fuel passage into the fuel inflow passage flows downward along the fuel inflow passage. This prolongs the time for which the fuel discharged from the fuel passage is located below the fuel inflow passage.

Next explained is a fuel pump system according to the 15th embodiment of the invention. In the fourteenth embodiment, when the fuel is supplied into the fuel container 94 via the fuel supply pipe 115, the fuel is also introduced into the fuel pump device 116 via the fuel introduction pipe 117. The fuel introduced into the fuel pump device 116 flows into the sub tank chamber 156. Therefore, the fuel liquid level in the sub tank chamber 156 rises. In the fourteenth embodiment, the internal space of the fuel container 94 is directly connected to the internal space of the sub tank chamber 156 via the negative pressure introducing pipe 165. Therefore, the evaporated fuel and the air in the sub tank chamber 156 may flow back into the fuel container 94 via the container evaporated fuel pipe 150. Therefore, in the fifteenth embodiment, gas is prevented from flowing back into the fuel container 94 from the sub tank chamber 156 during refueling.

As shown in FIGS. 35 and 36, the first
In the fifth embodiment, the negative pressure introducing pipe 1 is attached to the container evaporated fuel pipe 150.
65 is not provided, and a negative pressure introducing pipe for a sub tank chamber (hereinafter, simply referred to as a “negative pressure introducing pipe”) 173 is provided in the sub tank chamber 156, separately from the fuel vapor pipe for a container 150. The upper opening of the negative pressure introducing pipe 173 of the fifteenth embodiment opens in the sub tank chamber 156 in the upper region of the sub tank chamber 156. On the other hand, the lower opening of the negative pressure introducing pipe 173 of the fifteenth embodiment opens in the negative pressure generating housing 163.
The diameter of the lower opening of the negative pressure introducing pipe 173 is equal to that of the evaporated fuel pipe 1 for container.
Smaller than 50 diameter. The other configurations related to the fuel tank and the fuel pump device are the same as those in the fourteenth embodiment, and the description thereof will be omitted.

Next, the operation of the fuel pump system according to the fifteenth embodiment of the present invention will be described. Fuel is the fuel supply pipe 115
When it is introduced into the fuel container 94 via the, the fuel is also introduced into the sub tank chamber 156. Therefore, the fuel liquid level in the sub tank chamber 156 rises. In the fifteenth embodiment, the space above the fuel liquid level in the sub tank chamber 156 does not directly communicate with the internal space in the fuel container 94. Therefore, the fuel vapor and the air in the sub tank chamber 156 are prevented from flowing back into the fuel container 94 during refueling.
Therefore, the amount of evaporated fuel and air in the fuel container 94 before the fuel pump 157 is operated is kept small. Therefore, when the fuel pump 157 is operated, the evaporated fuel and the air in the fuel container 94 are completely removed at an early stage. The other operations relating to the fuel tank and the fuel pump device are the same as those in the fourteenth embodiment, and the description thereof will be omitted.

Instead of the level sensor of the above embodiment, a gas detection sensor for detecting the presence or absence of a gas containing evaporated fuel existing above the liquid level in the fuel chamber may be used. Also, instead of the maximum height of the liquid level, the volume of the space above the liquid level in the fuel chamber or the amount of gas in the fuel chamber is detected, and the execution of the evaporative fuel discharge action is controlled according to this volume or amount. Each of the cutoff valves may be opened and closed. Further, in the above-described embodiment, whether or not the evaporative fuel discharge action is executed is determined depending on whether or not the fuel liquid level in the fuel chamber is at the maximum height. However, the fuel liquid level in the fuel chamber is set to a predetermined height. Whether or not to execute the evaporative fuel discharge action may be determined depending on whether or not the amount of gas in the fuel chamber is greater than a predetermined amount. Of course, in the above-described embodiment, when the level sensor detects that the fuel level does not reach the maximum height in the fuel chamber, it is determined that a certain amount of gas is present in the fuel chamber.

[0149]

According to the first aspect of the present invention, since the volume of the space above the liquid surface of the fuel in the fuel chamber is kept small, generation of evaporated fuel in the fuel chamber is suppressed. Further, according to the fifteenth aspect, since the gas in the pump chamber is discharged by the negative pressure, the fuel liquid level in the pump chamber is raised, and therefore, the fuel in the pump chamber is prevented from being depleted. Further, according to the eighteenth aspect, the fuel liquid level in the fuel chamber is raised only when the engine operation is in a state of being able to receive the evaporated fuel, so the discharged evaporated fuel does not interfere with the engine operation and enters the intake system. be introduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a fuel storage device according to a first embodiment.

2 is a cross-sectional view of the fuel storage device taken along line II-II of FIG.

FIG. 3 is a cross-sectional view showing a fuel storage device immediately after refueling.

FIG. 4 is a cross-sectional view showing a fuel storage device when fuel is consumed.

FIG. 5 is a sectional view showing a fuel storage device according to a second embodiment.

FIG. 6 is a flowchart showing an evaporative fuel discharge operation of the second embodiment.

FIG. 7 is a sectional view showing a fuel storage device according to a third embodiment.

FIG. 8 is a flowchart showing an evaporative fuel discharge operation according to a third embodiment.

FIG. 9 is a sectional view showing a fuel storage device according to a fourth embodiment.

FIG. 10 is a flowchart showing an evaporative fuel discharging action according to a fourth embodiment.

FIG. 11 is a sectional view showing a fuel storage device according to a fifth embodiment.

FIG. 12 is a flowchart showing an evaporative fuel discharge operation of the fifth embodiment.

FIG. 13 is a sectional view showing a fuel storage device according to a sixth embodiment.

FIG. 14 is a sectional view showing a fuel storage device according to a seventh embodiment.

FIG. 15 is a flow chart showing an evaporative fuel discharge operation of a seventh embodiment.

FIG. 16 is a sectional view showing a fuel storage device according to an eighth embodiment.

FIG. 17 is a flowchart showing an evaporative fuel discharge operation according to the eighth embodiment.

FIG. 18 is a sectional view showing a fuel storage device of a ninth embodiment.

FIG. 19 is a flowchart showing an evaporative fuel discharging action according to a ninth embodiment.

FIG. 20 is a sectional view showing a fuel storage device according to a tenth embodiment.

FIG. 21 is a flow chart showing an evaporative fuel discharge operation of the tenth embodiment.

FIG. 22 is a flow chart showing an evaporative fuel discharge operation of the tenth embodiment.

FIG. 23 is a sectional view showing a fuel storage device of an eleventh embodiment.

FIG. 24 is a sectional view showing a fuel storage device of a twelfth embodiment.

FIG. 25 is a sectional view showing a fuel storage device of a thirteenth embodiment.

FIG. 26 is a flow chart showing an evaporated fuel discharge operation of the thirteenth embodiment.

FIG. 27 is a flow chart showing an evaporative fuel discharge operation of the thirteenth embodiment.

FIG. 28 is a partial cross-sectional view showing the fuel storage device of the fourteenth embodiment of the present invention.

FIG. 29 is a perspective view of a fuel container according to a fourteenth embodiment of the present invention.

FIG. 30 is a perspective view of the fuel container in an inflated state.

FIG. 31 is a perspective view of the fuel container in a recessed state.

FIG. 32 is a partial cross-sectional view showing a fuel pump device according to a fourteenth embodiment of the present invention.

33 is a cross-sectional view of the fuel pump device taken along line XXXIII-XXXIII of FIG. 32.

FIG. 34 is a partial cross-sectional view showing a fuel pump device of another embodiment different from the fourteenth embodiment of the present invention.

FIG. 35 is a partial cross-sectional view showing a fuel pump device according to a fifteenth embodiment of the present invention.

36 is a cross-sectional view of the fuel pump device taken along the line XXXVI-XXXVI of FIG. 34.

[Explanation of symbols]

1 ... Fuel storage device 6 ... Air chamber 7 ... Fuel chamber 26 ... Charcoal canister 35 ... Pump 37 ... Relief valve 51 ... Solenoid valve 57 ... Level switch 58 ... Atmosphere release control valve 59 ... Second relief valve 60 ... Solenoid valve 94 ... Fuel container 115 ... Fuel supply pipe 116 ... Fuel pump device 118 ... Evaporative fuel pipe for pump 150 ... Evaporative fuel pipe for container 159 ... Pressure regulator 161 ... Fuel return pipe 163 ... Negative pressure generating housing 165, 173 ... Negative pressure introduction pipe for sub storage device chamber 166 ... Fuel inflow passage 169 ... Fuel passage passage 170 ... Mesh partition wall 171 ... Passage division wall

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 37/00 311 F02M 37/00 311A 25/08 25/08 F 301 301S // B60K 15/03 B60K 15/02 L 15/077 A (72) Inventor Yoshihiko Hyodo 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Takaaki Ito 1 Toyota Town, Aichi Prefecture, Toyota Motor Corporation (72) ) Inventor Toru Kiso 1 Toyota Town, Toyota City, Aichi Prefecture F-term in Toyota Motor Corporation (Reference) 3D038 CA25 CC05 CC07 CC13 3G044 DA04 GA04 GA08 GA16

Claims (14)

[Claims] 1. A membrane wall which forms a fuel chamber and is deformable according to the amount of fuel in the fuel chamber, a communication port opening to a space above the fuel liquid level in the fuel chamber, and a space above the fuel liquid level. When the volume of the liquid becomes larger than a predetermined volume, the valve is opened to open the communication port, while when the volume of the space above the fuel level becomes smaller than the predetermined volume, the valve is closed and the communication port is opened. In a fuel storage device including a shutoff valve for shutting off the fuel, when the volume of the space above the fuel liquid level is larger than the predetermined volume and the shutoff valve is open, By discharging the gas in the space above the fuel liquid level from above the fuel liquid level through the communication port using the above means, the volume of the space above the fuel liquid level is reduced, and the space above the fuel liquid level is reduced. Is smaller than the predetermined volume The fuel storage device is characterized in that the shutoff valve closes and the discharge of gas from above the fuel liquid level via the communication port is stopped. 2. After the gas is discharged from above the liquid surface of the fuel and the volume of the space above the liquid surface of the fuel becomes smaller than the predetermined volume and the shutoff valve is closed, the fuel in the fuel chamber is closed. The volume of the space above the fuel level is kept smaller than the predetermined volume by keeping the shutoff valve closed even if the amount becomes small. The fuel storage device described in 1. 3. The fuel storage device according to claim 2, wherein the shutoff valve is a shutoff valve that is closed by the fuel that has reached the shutoff valve. 4. A liquid level detection means for detecting the position of the liquid fuel level in the fuel chamber is provided, and the position of the liquid fuel level detected by the liquid level detection means has not reached a predetermined height. The fuel storage device according to claim 1, wherein it is determined that the volume of the space above the liquid surface of the fuel is larger than the predetermined volume. 5. The fuel storage device according to claim 1, wherein gas is exhausted from above the fuel liquid level through the communication port by raising the fuel liquid level in the fuel chamber. 6. The fuel level in the fuel chamber is raised by deforming the membrane wall.
The fuel storage device described in 1. 7. The fuel storage device according to claim 6, wherein an air chamber is formed inside the fuel storage device by the film wall, and the film wall is deformed by pressurizing the air chamber. . 8. The fuel storage device according to claim 6, wherein the membrane wall is deformed by introducing a negative pressure into a space above the liquid surface of the fuel in the fuel chamber. 9. A pump for pumping fuel from the fuel chamber is provided, and a negative pressure generated by the fuel pumped by the pump causes the communication port to open in a space above the liquid surface of the fuel in the fuel chamber. The fuel storage device according to claim 8, wherein the fuel storage device is introduced via a fuel storage device. 10. The method according to claim 9, wherein a part of the fuel pumped by the pump is returned to the fuel chamber, and the negative pressure is generated by the refluxed fuel returned to the fuel chamber. Fuel storage device. 11. The pump is housed in a pump chamber connected to the fuel chamber, a part of the fuel pumped by the pump is returned to the pump chamber, and the reflux fuel returned to the pump chamber is used. The fuel storage device according to claim 9, wherein the generated negative pressure is also introduced into a space above the fuel liquid level in the pump chamber. 12. The communication port is connected to an intake system, and the negative pressure of the intake system is introduced into a space above the fuel liquid level in the fuel chamber via the communication port. Item 8. The fuel storage device according to item 8. 13. An atmosphere opening control in which the communication port is connected to an intake system via a canister that adsorbs evaporated fuel, and the canister is opened at a predetermined negative pressure or less to communicate the canister with the atmosphere. The fuel storage device according to claim 12, further comprising a valve. 14. The fuel liquid level in the fuel chamber is raised only when the communication port is connected to an intake system and only when the engine is in a state capable of receiving evaporated fuel. Fuel storage device.