KR20090104128A - Fuel battery - Google Patents

Abstract

A fuel battery capable of stably supplying fuel to the fuel battery cells, improved in efficiency of power generation reaction, and excellent in output characteristic by preventing decrease of the internal pressure of the fuel container due to decrease of the liquid fuel during power generation and by ensuring substantial liquid feeding ability of the pump. The fuel battery (1) comprises a membrane-electrode assembly (2), a fuel supply mechanism (3), and an internal pressure adjusting mechanism (4). The membrane-electrode assembly (2) has a fuel electrode (13), an air electrode (16), and an electrolyte membrane (17) sandwiched between them. The fuel supply mechanism (3) has a fuel distribution mechanism (5) disposed near the fuel electrode (13) of the membrane/electrode assembly (2), a fuel containing unit (6), a passage (7) interconnecting them, and a pump (8) installed in the passage (7). The internal pressure adjusting mechanism (4) is used for introducing external air when the internal pressure of the fuel containing unit (6) decreases and is installed nearer to the fuel containing unit (6) than the pump (8) of the fuel supply mechanism (3).

Description

Fuel cell {FUEL BATTERY}

The present invention relates to a fuel cell using a liquid fuel.

In recent years, in order to be able to use various portable electronic devices, such as a notebook type personal computer and a mobile telephone, without charging for a long time, the attempt to use a fuel cell for the power source of these portable electronic devices is made. A fuel cell can generate electricity only by supplying fuel and air, and it is possible to continuously generate electricity for a long time by replenishing fuel. For this reason, if a fuel cell can be miniaturized, it can be said that it is a very advantageous system as a power supply of a portable electronic device.

Direct methanol fuel cells (DMFCs) are promising as power sources for portable electronic devices because they can be downsized and easy to handle fuel. As the liquid fuel supply method in the DMFC, active methods such as a gas supply type and a liquid supply type, and passive systems such as an internal vaporization type in which the liquid fuel in the fuel containing portion is vaporized inside the cell and supplied to the fuel electrode are known.

Among them, passive systems such as internal vaporization type are particularly advantageous for downsizing the DMFC. In the passive DMFC, a structure in which a membrane electrode assembly (fuel battery cell) having, for example, a fuel electrode, an electrolyte membrane, and an air electrode is arranged on a fuel container made of a resin box-shaped container is proposed (for example, a patent). See Document 1). When supplying the vaporized fuel directly from the fuel container to the fuel cell, it is important to increase the controllability of the output of the fuel cell, but in the passive DMFC of development, sufficient output controllability is not necessarily obtained.

On the other hand, connecting the fuel cell of the DMFC and the fuel accommodating portion via a flow path has been studied (see Patent Documents 2 to 4). By supplying the liquid fuel supplied from the fuel containing portion to the fuel cell via the flow path, the supply amount of the liquid fuel can be adjusted based on the shape and diameter of the flow path. Patent Literature 3 describes supplying a liquid fuel from a fuel container to a flow path by means of a pump, and also describes using an electric field forming means for forming an electric permeate flow in the flow path. In addition, Patent Document 4 describes that a liquid fuel or the like is supplied using an electric permeation flow pump. However, in a fuel cell having a fuel circulating structure, it is effective to provide a pump or the like. However, for a fuel cell having a structure that does not circulate fuel such as a passive DMFC, even if a pump or the like is simply installed, the fuel consumption increases and is sufficient. I can't get the output.

[Patent Document 1] International Publication No. 2005/112172

[Patent Document 2] Japanese Unexamined Patent Publication No. 2005-518646

[Patent Document 3] Japanese Unexamined Patent Publication No. 2006-085952

[Patent Document 4] US Patent Publication No. 2006/0029851

The present invention suppresses a decrease in the internal pressure of the fuel accommodating portion due to the reduction of the liquid fuel due to power generation, and secures a substantial liquid feeding capacity of the pump, thereby stabilizing the fuel supply to the fuel cell and improving the power generation reaction. It is an object of the present invention to provide a fuel cell having excellent output characteristics.

The fuel cell of the present invention is connected via a flow path having a pump to a membrane electrode assembly having a fuel electrode, an air electrode, an electrolyte membrane inserted and held by the fuel electrode and the air electrode, and a fuel distribution mechanism disposed on the fuel electrode side of the membrane electrode assembly. And a fuel supply mechanism having a fuel containing portion, and an internal pressure adjusting mechanism that is installed at at least a portion of the fuel containing portion than at least a pump of the fuel supplying mechanism and introduces outside air when the internal pressure of the fuel containing portion is lowered.

BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing which shows an example of the fuel cell of this invention.

2 is an external view illustrating an example of a fuel distribution mechanism.

3 is a cross-sectional view showing an example of a pressure adjusting mechanism (when not in operation).

4 is a cross-sectional view showing a state at the time of operation of the pressure adjusting mechanism shown in FIG. 3.

5 is a cross-sectional view showing another example of the pressure adjusting mechanism (when not in operation).

FIG. 6 is a cross-sectional view showing a state at the time of operation of the pressure adjusting mechanism shown in FIG. 5. FIG.

7 is a cross-sectional view showing an example of a pressure-resistant pressure adjusting mechanism (when not operated) having a pressure releasing mechanism.

FIG. 8 is a cross-sectional view showing a state of the pressure-resistant adjustment function of the pressure-resistant adjustment mechanism shown in FIG. 7. FIG.

9 is a cross-sectional view showing a state at the time of a pressure releasing function operation of the internal pressure adjusting mechanism shown in FIG. 7.

10 is a cross-sectional view showing another example of the internal pressure adjusting mechanism (when not operated) having a pressure releasing mechanism.

The cross section which shows the state at the time of the pressure-resistant adjustment function of the pressure-resistant adjustment mechanism shown in FIG.

It is sectional drawing which shows the state at the time of the pressure release function operation of the pressure-resistant adjustment mechanism shown in FIG.

13 is a cross-sectional view showing another example of a pressure-resistant pressure adjusting mechanism (not in operation) having a pressure releasing mechanism.

It is sectional drawing which shows the state at the time of the pressure-resistant adjustment function of the pressure-resistant adjustment mechanism shown in FIG.

It is sectional drawing which shows the state at the time of the pressure release function operation of the pressure-resistant adjustment mechanism shown in FIG.

* Explanation of symbols for the main parts of the drawings

1: fuel cell 2: fuel cell

3: fuel supply mechanism 4: internal pressure adjusting mechanism

5: fuel distribution mechanism 6: fuel container

7: euro 8: pump

11: anode catalyst layer 12: anode gas diffusion layer

13: anode (fuel electrode) 14: cathode catalyst layer

15: cathode gas diffusion layer 16: cathode (air electrode / oxidizer electrode)

17: Proton (hydrogen ion) conductive electrolyte membrane 40: case

40c: outside air hole 40d: fuel supply mechanism side hole

40h: Outside air hole 40i: Fuel supply mechanism side hole

41, 45, 46, 50, 51: valve body 46d: through hole

46e: non-fuel side opening (non-fuel mechanism side opening)

46g: Opening of the fuel supply mechanism side 47: Filter

50d: through hole

50e: non-fuel side opening (non-fuel mechanism side opening)

50f: side opening

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings. 1 is a cross-sectional view showing an example of a fuel cell of the present invention. The fuel cell 1 shown in FIG. 1 includes a fuel cell 2 constituting a power generation unit, a fuel supply mechanism 3 for supplying fuel to the fuel cell 2, and a fuel supply mechanism 3. It is mainly comprised by the withstand pressure adjustment mechanism 4 provided. In addition, the fuel supply mechanism 3 includes a fuel distribution mechanism 5, a fuel accommodating portion 6 for accommodating liquid fuel, and a flow path 7 for connecting the fuel dispensing mechanism 5 and the fuel accommodating portion 6. ) And a pump 8 arranged in the flow path 7. The internal pressure adjustment mechanism 4 is provided in the fuel accommodating part 6 of such fuel supply mechanisms 3, for example.

The fuel cell 2 includes an anode (fuel electrode) 13 having an anode catalyst layer 11 and an anode gas diffusion layer 12, and a cathode (air electrode / oxidant electrode) having a cathode catalyst layer 14 and a cathode gas diffusion layer 15. (16) and a membrane electrode assembly (MEA) composed of a proton (hydrogen ion) conductive electrolyte membrane 17 inserted and held by the anode catalyst layer 11 and the cathode catalyst layer 14. .

Examples of the catalyst contained in the anode catalyst layer 11 and the cathode catalyst layer 14 include a single group of platinum group elements such as Pt, Ru, Rh, Ir, Os, and Pd, an alloy containing a platinum group element, and the like. It is preferable to use Pt-Ru, Pt-Mo, etc. which have strong resistance to methanol, carbon monoxide, etc. as the anode catalyst layer 11. It is preferable to use Pt, Pt-Ni, or the like for the cathode catalyst layer 14. However, the catalyst is not limited to these, and various materials having catalytic activity can be used. The catalyst may be either a supported catalyst or an unsupported catalyst using a conductive support such as a carbon material.

As a proton conductive material which comprises the electrolyte membrane 17, For example, fluorine-type resin (Nafion (brand name, the DuPont company make), Flemion (brand name, the Asahi Glass company make), such as a perfluorosulfonic acid polymer which has a sulfonic acid group, etc. ), Organic materials such as hydrocarbon-based resins having sulfonic acid groups, or inorganic materials such as tungstic acid and phosphorus tungstic acid. However, the proton conductive electrolyte membrane 17 is not limited to these.

The anode gas diffusion layer 12 stacked on the anode catalyst layer 11 serves to uniformly supply fuel to the anode catalyst layer 11 and also serves as a current collector of the anode catalyst layer 11. The cathode gas diffusion layer 15 stacked on the cathode catalyst layer 14 serves to uniformly supply the oxidant to the cathode catalyst layer 14 and also serves as a current collector of the cathode catalyst layer 14. The anode gas diffusion layer 12 and the cathode gas diffusion layer 15 are composed of a porous substrate.

A conductive layer is laminated on the anode gas diffusion layer 12 or the cathode gas diffusion layer 15 as necessary. As these conductive layers, meshes, porous films, thin films, etc. made of a conductive metal material such as Au are used, for example. Rubber O-rings 19 are interposed between the electrolyte membrane 17, the fuel distribution mechanism 5, and the cover plate 18, respectively, thereby providing fuel from the fuel cell (MEA) 2 Leakage and oxidant leakage are prevented.

Although not shown, the cover plate 18 has an opening for introducing air, which is an oxidant. Between the cover plate 18 and the cathode 16, a moisturizing layer and a surface layer are arrange | positioned as needed. The moisturizing layer impregnates a part of the water generated in the cathode catalyst layer 14 to suppress the evaporation of water and promotes uniform diffusion of air into the cathode catalyst layer 14. The surface layer adjusts the amount of air introduced, and has a plurality of air inlets whose number, size and the like are adjusted according to the amount of air introduced.

The fuel container 6 contains liquid fuel corresponding to the fuel cell 2. As a liquid fuel, methanol fuel, such as aqueous methanol solution of various concentration, pure methanol, etc. are mentioned. Liquid fuel is not necessarily limited to methanol fuel. The liquid fuel may be, for example, ethanol fuel such as aqueous ethanol or pure ethanol, propanol fuel such as aqueous propanol or pure propanol, glycol fuel such as glycol aqueous solution or pure glycol, dimethyl ether, formic acid, or other liquid fuel. In any case, the fuel container 6 accommodates the liquid fuel according to the fuel cell 2.

The fuel distribution mechanism 5 is disposed on the anode (fuel electrode) 13 side of the fuel cell 2. The fuel distribution mechanism 5 is connected to the fuel containing portion 6 via a flow path 7 of liquid fuel, such as a pipe provided with a pump 8 on the way. Liquid fuel is introduced into the fuel distribution mechanism 5 from the fuel containing portion 6 via this flow path 7. The flow path 7 is not limited to the piping which is independent of the fuel distribution mechanism 5 and the fuel accommodating part 6. For example, when stacking and integrating the fuel distribution mechanism 5 and the fuel accommodating part 6, the flow path of the liquid fuel which connects these may be sufficient. The fuel distribution mechanism 5 should just be connected with the fuel containing part 6 via the flow path 7.

For example, as shown in FIG. 2, the fuel distribution mechanism 5 includes at least one fuel inlet 5a through which the liquid fuel flows through the flow path 7, and a plurality of fuels for discharging the liquid fuel and its vaporized components. A fuel distribution plate 5c having a discharge port 5b. Inside the fuel distribution plate 5c, as shown in FIG. 1, the space | gap part 5e used as the channel | path of the liquid fuel guide | induced from the fuel injection port 5a is provided. The plurality of fuel outlets 5b are directly connected to the spaces 5e respectively functioning as fuel passages.

The liquid fuel introduced into the fuel distribution plate 5c from the fuel inlet 5a enters the void portion 5e and is led to the plurality of fuel outlets 5b through the void portion 5e serving as this fuel passage, respectively. . For example, a plurality of fuel outlets 5b may be provided with a gas-liquid separator (not shown) that transmits only the vaporized component of the liquid fuel and does not transmit the liquid component. Thereby, the vaporization component of the liquid fuel is supplied to the anode (fuel electrode) 13 of the fuel cell 2. In addition, the gas-liquid separator may be provided as a gas-liquid separator or the like between the fuel distribution mechanism 5 and the anode 13. The vaporized component of the liquid fuel is discharged from the plurality of fuel outlets 5b toward the plurality of locations of the anode 13.

A plurality of fuel outlets 5b are provided on the surface of the fuel distribution plate 5c in contact with the anode 13 so that fuel can be supplied to the entire fuel cell 2. The number of fuel outlets 5b may be one or more, but in order to make the fuel supply amount in the surface of the fuel cell 2 uniform, it is formed so that the fuel outlets 5b of 0.1 to 10 / cm 2 exist. desirable. If the number of the fuel discharge ports 5b is less than 0.1 / cm 2, the fuel supply amount to the fuel cell 2 cannot be sufficiently uniform. Even if the number of the fuel outlets 5b is greater than 10 / cm 2, no further effect can be obtained.

The fuel discharged from the fuel distribution mechanism 5 is supplied to the anode (fuel electrode) 13 of the fuel cell 2 as described above. In the fuel cell 2, fuel is supplied to the anode catalyst layer 11 by diffusing the anode gas diffusion layer 12. When methanol fuel is used as a liquid fuel, the internal reforming reaction of methanol shown in the following formula (1) occurs in the anode catalyst layer 11. In the case where pure methanol is used as the methanol fuel, water generated in the cathode catalyst layer 14 or water in the electrolyte membrane 17 is reacted with methanol to generate an internal reforming reaction of the formula (1). Alternatively, the internal reforming reaction is generated by another reaction mechanism that does not require water.

_{CH 3 0H + H 2 O →} CO 2 + 6H + + 6e - ... (One)

The electrons (e ⁻ ) generated in this reaction are guided to the outside via the current collector, and then are driven to the cathode (air electrode) 16 after operating portable electronic devices or the like as so-called electricity. In addition, protons (H ⁺ ) generated in the internal reforming reaction of formula (1) are induced to the cathode 16 via the electrolyte membrane 17. The cathode 16 is supplied with air as an oxidant. Electrons (e ⁻ ) and protons (H ⁺ ) that have reached the cathode 16 react with oxygen in the air in the cathode catalyst layer 14 according to the following formula (2), and water is generated according to the reaction.

^{6e - + 6H + + (3/2} ) O 2 → 3H 2 O ... (2)

The pump 8 is not a circulation pump for circulating the fuel, but a fuel supply pump for delivering liquid fuel from the fuel container 6 to the fuel distribution mechanism 5 to the last. By supplying liquid fuel as needed by such a pump 8, controllability of the fuel supply amount can be improved. The fuel supplied from the fuel distribution mechanism 5 to the fuel cell 2 is used for the power generation reaction, and is not circulated thereafter to be returned to the fuel accommodating portion 6. Since the fuel cell 1 shown in FIG. 1 does not circulate fuel, it is different from the conventional active system, and does not impair the miniaturization of the apparatus. In addition, since the pump 8 is used for supplying the liquid fuel, and is also different from the conventional passive type like the conventional internal vaporization type, it is called a semi-passive type, for example.

Although the kind of the pump 8 is not specifically limited, A rotary van pump, an electric permeation pump, a diaphragm pump, a crimping pump, etc. can be sent from a viewpoint that a small amount of liquid fuel can be sent with favorable controllability, and it can also be made compact and lightweight. It is preferable to use. The rotary van pump rotates the blades by a motor to feed the liquid. The electric permeate flow pump utilizes a sintered porous body such as silica that causes the electric permeation flow phenomenon. A diaphragm pump drives a diaphragm and transmits liquid by electromagnets or piezoelectric ceramics. The compression pump presses a portion of the flexible fuel flow path and sweeps the fuel hardly. Among these, it is more preferable to use the diaphragm pump which has an electric permeation flow pump or a piezoelectric ceramic from a viewpoint of drive power, a magnitude | size, etc.

Since the main object of the fuel cell 1 is a small electronic device, it is preferable to set it as the range of 10 microliters / min-1 ml / min. When the liquid supply capacity exceeds 1 ml / min, the amount of liquid fuel delivered at one time becomes excessively large, and the stop time of the pump 8 that occupies the entire operation period becomes long. For this reason, the fluctuation | variation of the fuel supply amount to the fuel cell (MEA) 2 becomes large, and as a result, the fluctuation of an output becomes large. A reservoir for preventing this may be provided between the pump 8 and the fuel distribution mechanism 5, but even if such a configuration is applied, variations in the fuel supply amount cannot be sufficiently suppressed, and the size of the apparatus is increased. Done.

On the other hand, if the pumping capacity of the pump 8 is less than 10 µl / min, there is a fear that a shortage of the supplying capacity may occur when the consumption of fuel increases, such as at the start of the apparatus. Thereby, the starting characteristic of the fuel cell 1, etc. fall. In this regard, it is preferable to use a pump 8 having a liquid feeding capacity in the range of 10 µl / min to 1 ml / min. As for the liquid-feeding ability of the pump 8, it is more preferable to set it as the range of 10-200 microliters / minute. In order to realize such a liquid supply amount stably, it is preferable to apply the electric permeation flow pump or the diaphragm pump to the pump 8. In addition, as long as the fuel supply from the fuel distribution mechanism 5 to the fuel cell 2 is performed, it is also possible to arrange the fuel shutoff valve in place of the pump 8. In this case, the fuel shutoff valve is provided to control the supply of the liquid fuel by the flow path.

The internal pressure adjusting mechanism 4 is provided in the fuel container 6, for example. When the internal pressure of the fuel accommodating part 6 falls, the internal pressure adjustment mechanism 4 is provided in order to raise the internal pressure to about atmospheric pressure by introducing external air. Conventionally, when the liquid fuel in the fuel accommodating portion is supplied to the fuel cell by a pump, the internal pressure decreases with the decrease of the liquid fuel in the fuel accommodating portion due to power generation, while the fuel cell cell side is almost at atmospheric pressure. The actual liquid supply capacity of the pump is lowered. For this reason, the fuel supply amount to a fuel cell may decrease, and sufficient output may not always be obtained.

In the fuel cell 1 according to the present invention, by providing the internal pressure adjusting mechanism 4, when the internal pressure of the fuel accommodating portion 6 decreases, the outside air can be introduced and the internal pressure can be returned to the atmospheric pressure, and the pump 8 Can restore the ability to deliver For this reason, the fuel supply amount to the fuel cell 2 can be stabilized, and stable output characteristics can be obtained. In addition, in the fuel cell 1 shown in FIG. 1, the internal pressure adjusting mechanism 4 is provided in the fuel accommodating portion 6, but the internal pressure adjusting mechanism 4 is at least the fuel accommodating portion 6 side, rather than the pump 8. That is, what is necessary is just to be provided in the flow path 7 or the fuel accommodating part 6 by the side of the fuel accommodating part 6 of the pump 8.

The internal pressure adjusting mechanism 4 is preferably operated when the internal pressure of the fuel accommodating portion 6 is lower than the atmospheric pressure, and preferably at least 0.02 MPa lower than the atmospheric pressure. As the internal pressure of the fuel accommodating portion 6 is lower than atmospheric pressure, the actual liquid feeding ability of the pump is lowered. For this reason, when the internal pressure of the fuel accommodating part 6 becomes 0.02 Mpa lower than atmospheric pressure at the latest, by operating the internal pressure adjustment mechanism 4, the fall of the substantially liquid supply capability of a pump is suppressed and the output of the fuel cell 1 is suppressed. Can be stabilized. Hereinafter, the internal pressure of the fuel accommodating part 6 at the time of the internal pressure adjustment mechanism 4 is called an internal pressure lower limit. Moreover, this lower limit of internal pressure is a pressure lower than atmospheric pressure, More preferably, it can set suitably according to the liquid-feeding ability of the pump 8 in the range more than the pressure of 0.01 MPa lower than atmospheric pressure.

Hereinafter, the internal pressure adjusting mechanism 4 will be described in detail. In addition, about each figure which shows the following internal pressure adjustment mechanism 4, the fuel supply mechanism 3 (in this case, the fuel accommodating part 6) is arrange | positioned at the right side in all figures. In addition, below, the fuel supply mechanism 3 side (right side in drawing) is called a fuel side, and the opposite side (left side in drawing) is called a non-fuel side, and is demonstrated. In addition, even if it is between different internal pressure adjustment mechanism 4, what has substantially the same function or structure is attached and demonstrated the same code | symbol.

3 and 4 are cross-sectional views showing an example of the internal pressure adjusting mechanism 4, and FIG. 3 shows a state when the internal pressure adjusting function is not activated when the internal pressure of the fuel container 6 is higher than the lower internal pressure limit. 4 shows the state when the internal pressure of the fuel accommodating part 6 became below an internal pressure lower limit, and the internal pressure adjustment function was operated.

First, as shown in FIG. 3, in the internal pressure adjusting mechanism 4, the valve body 41 of the substantially axial shape is arrange | positioned in the case 40 of a substantially cylindrical shape. The substantially cylindrical case 40 is, for example, a first case portion 40a on the non-fuel side and a second case portion in which a portion is inserted into the inner diameter side of the fuel side of the first case portion 40a. It consists of 40b. On the non-fuel side of the second case portion 40b as the inner diameter side of the first case portion 40a, the leakage of liquid fuel from the joint portions of the first case portion 40a and the second case portion 40b is suppressed. For example, an O-ring 42 made of rubber is provided. Moreover, the outside air side hole part 40c and the fuel supply mechanism side hole part 40 are provided in the non-fuel side and fuel side axial part of the case 40, respectively. In addition to the method of interposing the rubber O-ring 42 in the joint portion, the case 40 can also be suitably used for hermetically sealing the joint portion using ultrasonic welding or the like.

The valve body 41 is mainly composed of a non-fuel side shaft portion 41a disposed on the non-fuel side, a fuel supply mechanism side shaft portion 41c disposed on the fuel side, and a large diameter portion 41b therebetween. The blade part 41d is provided in the outer peripheral part of the large diameter part 41b on the non-fuel side. The non-fuel side shaft portion 41a is inserted into the outer air side hole portion 40c, and the fuel supply mechanism side shaft portion 41c is similarly inserted into the fuel supply mechanism side hole portion 40d. The outer diameter of the non-fuel side shaft portion 41a is smaller than the inner diameter of the outer air side hole portion 40c, and a gap is formed between the outer air side hole portion 40c and the non-fuel side shaft portion 41a so as to allow outside air to flow therein. Formed. Similarly, the outer diameter of the fuel supply mechanism side shaft portion 41c is smaller than the inner diameter of the fuel supply mechanism side hole portion 40d, and between the fuel supply mechanism side hole portion 40d and the fuel supply mechanism side shaft portion 41c. The gap is formed so that outside air can be introduced. In particular, the fuel supply mechanism-side shaft portion 41c has a cross-sectional shape that is substantially cross-shaped, and is configured to allow a sufficient amount of outside air to flow in, and also to be able to be centered in the axial direction. It is.

As the non-fuel side of the large diameter portion 41b, a rubber O-ring 43 is provided, for example, around the non-fuel side shaft portion 41a. In addition, a spring 44 is provided around the large diameter portion 41b and the fuel supply mechanism side shaft portion 41c as the fuel side of the blade portion 41d. By this spring 44, the valve body 41 is pressed to the non-fuel side. As a result, the O-ring 43 is pressed by the inner wall of the case 40 and the non-fuel side of the large diameter portion 41b. Thus, when the O-ring 43 is depressed, the leakage of the liquid fuel through the outside air hole 40c from the case 40 is suppressed when the internal pressure adjusting function is not activated.

On the other hand, when the internal pressure of the fuel accommodating part 6 becomes below the internal pressure lower limit, as shown in FIG. 4, the valve body 41 is led in to the fuel side by the internal pressure fall of the fuel accommodating part 6. As shown in FIG. Here, the repulsive force of the spring 44 is adjusted to the extent that the valve body 41 pulls in to the fuel side when the internal pressure of the fuel accommodating part 6 becomes below an internal pressure lower limit. In addition, the internal pressure (lower pressure limit value) of the fuel accommodating part 6 when the valve body 41 is drawn in to the fuel side can be appropriately set. Specifically, the lower the repulsive force of the spring 44, the higher the internal pressure can be. The stronger the repulsive force, the lower the internal pressure.

As shown in FIG. 4, when the valve body 41 moves to the fuel side, the O-ring 43 also moves to the fuel side, and a gap is formed between the inner wall of the case 40 and the O-ring 43. At this time, since the pressure on the fuel side is lower than that on the non-fuel side, outside air is introduced into the case 40 from the outside air hole 40c. The outside air introduced from the outside air hole 40c passes through the gap between the inner wall of the case 40 and the O-ring 43, and again the blade portion 41d and the large diameter portion 41b in the case 40. It passes through the outer diameter side, and finally passes through the fuel supply mechanism side hole part 40d and the fuel supply mechanism side shaft part 41c, and is introduce | transduced into the fuel accommodating part 6. As a result of the introduction of the outside air into the fuel containing portion 6, the internal pressure of the fuel containing portion 6 rises and exceeds the internal pressure lower limit.

After the internal pressure of the fuel accommodating portion 6 exceeds the internal pressure lower limit value, the strength of drawing the valve body 41 to the fuel side becomes weak, and as shown in FIG. 3, the valve is again caused by the repulsive force of the spring 44. The sieve 41 is pressed to the non-fuel side, and leakage of the liquid fuel from the case 40 through the outside air hole 40c is suppressed.

Next, another example of the internal pressure adjusting mechanism 4 will be described. 5 and 6 are cross-sectional views showing another example of the internal pressure adjusting mechanism 4, and FIG. 5 is a state when the internal pressure adjusting function is not operated when the internal pressure of the fuel container 6 is higher than the lower pressure limit. 6 shows the state when the internal pressure of the fuel accommodating part 6 becomes below an internal pressure lower limit, and the internal pressure adjustment function was operated.

In this internal pressure adjustment mechanism 4, the substantially axial valve body 45 is arrange | positioned in the substantially cylindrical case 40. As shown in FIG. The case 40 is, for example, a first case part 40a on the non-fuel side and a second case part 40b in which a part of the case is inserted into the inner diameter side of the fuel side of the first case part 40a. Consists of. At the non-fuel side and the fuel side shaft portion of the case 40, an external air side hole portion 40c and a fuel supply mechanism side hole portion 40d are respectively provided. The opening on the fuel side of the outside air hole 40c is a hemispherical recess 40e.

The valve body 45 is provided on the non-fuel side, and has a hemispherical shaft portion 45a that has a hemispherical shape toward the non-fuel side, and a hemispherical shaft portion 45a disposed on the fuel side of the hemispherical shaft portion 45a. It consists of a large diameter blade part 45d and the fuel supply mechanism side shaft part 45c extended toward the fuel side of the blade part 45d. The hemispherical shaft part 45a is fitted to the recessed part 40e. The fuel supply mechanism side shaft portion 45c is inserted into the fuel supply mechanism side hole portion 40d. The outer diameter of the fuel supply mechanism side shaft portion 45c is smaller than the inner diameter of the fuel supply mechanism side hole portion 40d, and the outside air is provided between the fuel supply mechanism side hole portion 40d and the fuel supply mechanism side shaft portion 45c. A gap is formed so that it can pass.

A spring 44 is provided around the fuel supply mechanism side shaft portion 45c as the fuel side of the blade portion 45d. The valve body 45 is pressed toward the non-fuel side by the spring 44, and the hemispherical shape thereof. The shaft portion 45a is fitted to the recessed portion 40e. Thus, since the hemispherical shaft part 45a is fitted in the recessed part 40e, the leakage of the liquid fuel through the outside air hole 40c from the case 40 is suppressed when the internal pressure adjustment function is not operating. .

On the other hand, when the internal pressure of the fuel accommodating part 6 becomes below an internal pressure lower limit, as shown in FIG. 6, the valve body 45 is led in to the fuel side by the internal pressure fall of the fuel accommodating part 6 being reduced. As the valve body 45 moves to the fuel side, the hemispherical shaft portion 45a is separated from the recess 40e, and a gap is formed therebetween. At this time, since the pressure on the fuel side is lower than that on the non-fuel side, outside air is introduced into the case 40 from the outside air hole 40c. The outside air introduced from the outside air hole 40c passes through the gap between the recess 40e and the hemispherical shaft portion 45a, and again the blade portion 45d and the fuel supply mechanism side shaft portion (in the case 40). It passes through the outer diameter side of 45c, and finally enters into the fuel containing part 6 through the fuel supply mechanism side hole part 40d and the fuel supply mechanism side shaft part 45c. As a result of the introduction of the outside air into the fuel containing portion 6, the internal pressure of the fuel containing portion 6 rises and exceeds the internal pressure lower limit.

After the internal pressure of the fuel accommodating portion 6 exceeds the internal pressure lower limit, the strength of drawing the valve body 45 to the fuel side becomes weak, and as shown in FIG. 5, the valve is again caused by the repulsive force of the spring 44. The sieve 45 is pressed from the fuel side to the non-fuel side, and leakage of the liquid fuel from the case 40 through the outside air hole 40c is suppressed.

Next, the internal pressure adjusting mechanism 4 having the pressure releasing mechanism will be described. The pressure release mechanism releases the internal pressure in order to prevent breakage due to the internal pressure rise of the fuel container 6. It is preferable that the pressure releasing mechanism operates when the internal pressure of the fuel accommodating portion 6 becomes higher than the atmospheric pressure as the operating pressure thereof, and preferably when the pressure releasing mechanism reaches 0.3 MPa at the latest. When the internal pressure of the fuel accommodating portion 6 is 0.3 MPa, the pressure releasing mechanism is operated, whereby damage to the fuel accommodating portion 6 or the like is effectively suppressed. Hereinafter, the internal pressure of the fuel accommodating part 6 at the time of a pressure release mechanism is called an internal pressure upper limit. In addition, this upper limit of internal pressure is a pressure exceeding atmospheric pressure, Preferably it can change suitably according to the intensity | strength of the fuel accommodating part 6, etc. in the range of 0.3 Mpa or less.

7 to 9 show an example of the internal pressure adjusting mechanism 4 (hereinafter, also simply referred to as the internal pressure adjusting mechanism 4) having a pressure releasing mechanism, which has a pair of valve bodies, and an axial center on one valve body thereof. Through holes are installed according to. FIG. 7 shows a state when the internal pressure of the fuel accommodating portion 6 is higher than the lower internal pressure lower limit and lower than the upper internal pressure upper limit, and neither the internal pressure adjusting function nor the pressure releasing function is operated. FIG. 8 shows a state when the internal pressure of the fuel accommodating portion 6 is equal to or lower than the lower pressure resistance value, and the pressure resistance adjusting function is activated. 9 shows a state when the internal pressure of the fuel accommodating portion 6 is equal to or higher than the internal pressure upper limit and the pressure release function is activated.

As shown in FIG. 7, the internal pressure adjusting mechanism 4 has a valve body 46 and a fuel side in the case 40, which are first valve chains arranged along an axial center on a non-fuel side in a substantially cylindrical case 40. It has the valve body 41 which is a 2nd valve body arrange | positioned along the shaft center. The case 40 includes, for example, a first case portion 40a on the non-fuel side, a second case portion 40b on which a portion of the first case portion 40a is fitted to the inner diameter side of the fuel side, and And the third cylindrical case portion 40f having a substantially cylindrical shape disposed on the non-fuel side of the second case portion 40b as the inner diameter side of the first case portion 40a. Between the fuel side of the third case portion 40f and the non-fuel side of the second case portion 40b, an O-ring 42 made of rubber, for example, for suppressing leakage of liquid fuel from the joint portion is provided. It is. The non-fuel side of the 3rd case part 40f becomes the coupling part 40g of a small diameter. On the non-fuel side and the fuel side of the case 40, the external air side hole portions 40c and 40h and the fuel supply mechanism side hole portions 40d are respectively provided.

The valve body 46 has a non-fuel side shaft portion 46a and a fuel supply mechanism side shaft portion 46b, and a large diameter engaging portion 46c is provided on the outer diameter side. Moreover, 46 d of through-holes are provided in the valve body 46 along the axial center. 46 d of through-holes are provided in the non-fuel side, the non-fuel side opening part 46e in which the filter 47 for preventing a foreign material mixing from the non-fuel side, and the fuel side are provided in the valve body ( It consists of the fuel supply mechanism side opening part 46g in which the non-fuel side shaft part 41a of 41 is inserted, and the connection hole 46f provided between them. The inner diameter of the fuel supply mechanism side opening portion 46g is larger than the outer diameter of the non-fuel side shaft portion 41a, and a gap is formed between them. In addition, the filter 47 does not necessarily need to be fitted in the non-fuel side opening 46e, and the inner diameter of the non-fuel side opening 46e may be the same as the inner diameter of the connection hole 46f.

The non-fuel side shaft portion 46a is inserted into the outside air hole 40c, and the fuel supply mechanism side shaft portion 46b is inserted into the coupling portion 40g. The outer diameter of the fuel supply mechanism side shaft portion 46b is smaller than the inner diameter of the coupling portion 40g, and a gap is formed between the coupling portion 40g and the fuel supply mechanism side shaft portion 46b.

As the non-fuel side of the engaging portion 46c, a spring 48 is provided around the non-fuel side shaft portion 46a, and the valve body 46 is pushed toward the fuel side by the repulsive force of the spring 48. A rubber O-ring 49 is provided around the fuel supply mechanism-side shaft 46b as the fuel side of the coupling portion 46c, and the O-ring 49 is coupled to the coupling portion 46c. It is pressed by the coupling part 40g. As the O-ring 49 is pressed by the coupling portion 46c and the coupling portion 40g in this way, the outflow of liquid fuel to the non-fuel side between the coupling portion 40g and the fuel supply mechanism side shaft portion 46b is prevented. Suppressed.

The valve body 41 is the same as that shown in FIGS. 3 and 4. 3 and 4, the non-fuel side shaft portion 41a is inserted into the fuel supply mechanism side opening 46g. In addition, the O-ring 43 is pressed by the fuel supply mechanism side shaft portion 46b and the large diameter portion 41b. As the O-ring 43 is pressed by the fuel supply mechanism side shaft portion 46b and the large diameter portion 41b in this manner, the outflow of the liquid fuel through the fuel supply mechanism side opening 46g to the non-fuel side is suppressed.

When the internal pressure of the fuel accommodating part 6 becomes below an internal pressure lower limit, as shown in FIG. 8, the valve body 41 is led in to the fuel side by the internal pressure fall of the fuel accommodating part 6. As shown in FIG. In addition, the principle which the valve body 41 pulls in to the fuel side by the internal pressure fall of the fuel accommodating part 6 is the same as that of the principle demonstrated by FIG. 3 and FIG. As the valve body 41 moves to the fuel side, the O-ring 43 also moves to the fuel side, and a gap is formed between the fuel supply mechanism side shaft portion 46b and the O-ring 43. At this time, since the pressure on the fuel side is lower than that on the non-fuel side, outside air is introduced into the non-fuel side opening 46e through the filter 47. The outside air introduced into the non-fuel side opening 46e passes through the gap between the fuel supply mechanism side opening 46g and the non-fuel side shaft portion 41a, and again the fuel supply mechanism side shaft portion 46b and the O-ring 43. Go through the gap. Finally, the outside air passes through the outer diameter portions of the blade portion 41d and the large diameter portion 41b, and the fuel containing portion 6 is separated from the gap between the fuel supply mechanism side hole portion 40d and the fuel supply mechanism side shaft portion 41c. Is introduced. As a result, the internal pressure of the fuel accommodating part 6 rises and becomes higher than a lower internal pressure limit value.

When the internal pressure of the fuel accommodating portion 6 becomes higher than the lowering pressure lower limit value, the repulsive force of the spring 44 becomes stronger than the strength of drawing the valve body 41 into the fuel side, so that the valve body 41 as shown in FIG. ) Is pressed again to the non-fuel side, and leakage of the liquid fuel through the through hole 46d is suppressed.

On the other hand, when the internal pressure of the fuel accommodating part 6 becomes more than an internal pressure upper limit, as shown in FIG. 9, the valve body 46 is pressed to the non-fuel side by the internal pressure rise of the fuel accommodating part 6, and the O-ring 49 And a gap is formed between the coupling portion 40g. Here, the repulsive force of the spring 48 is adjusted so that the valve body 46 can move to the non-fuel side when the internal pressure of the fuel accommodating part 6 becomes more than an internal pressure upper limit value. In addition, the internal pressure (upper-pressure upper limit value) of the fuel accommodating part 6 when the valve body 46 moves to the non-fuel side can be set suitably, specifically, the internal pressure can be made low by weakening the repulsive force of the spring 48. And the internal pressure can be made high by strengthening the repulsive force.

A gap is formed between the O-ring 49 and the engaging portion 40g, so that the internal pressure in the fuel accommodating portion 6 is in turn the gap between the fuel supply mechanism side hole portion 40d and the fuel supply mechanism side shaft portion 41c, and the blade. Finally, through the outer diameter side of the portion 41d, between the coupling portion 40g and the fuel supply mechanism side shaft portion 46b, and the outer diameter side of the coupling portion 46c, the external air side hole portion 40c and the non-fuel side shaft portion It is free | released to the non-fuel side from the clearance gap of 46a or the external air side hole part 40h. As a result, the internal pressure of the fuel accommodating part 6 becomes lower than an internal pressure upper limit.

When the internal pressure of the fuel accommodating part 6 becomes lower than an internal pressure upper limit, the repulsive force of the spring 48 becomes strong compared with the intensity | strength which presses the valve body 46 to a non-fuel side, and the valve body by the repulsive force of this spring 48 46 is pressed to the fuel side. As a result, as shown in FIG. 7, the O-ring 49 is pressed by the engaging portion 46c and the engaging portion 40g, and the outflow of the liquid fuel from these to the non-fuel side is suppressed.

10-12 show another example of the internal pressure adjusting mechanism 4 having a pressure releasing mechanism, and shows another example of having a pair of valve bodies and having a through hole along an axis in one valve body. . FIG. 10 shows a state when the internal pressure of the fuel accommodating portion 6 is higher than the lower pressure resistance lower limit value and lower than the upper pressure resistance upper limit value, and neither the pressure resistance adjusting function nor the pressure releasing function is operated. FIG. 11 shows a state when the internal pressure of the fuel accommodating portion 6 is equal to or lower than the internal pressure lower limit and the internal pressure adjusting function is activated. FIG. 12 shows a state when the internal pressure of the fuel container 6 becomes equal to or higher than the internal pressure upper limit and the pressure release function is activated.

As shown in FIG. 10, the internal pressure adjusting mechanism 4 includes the first valve body 46 and the fuel in the case 40, which are arranged along the axial center on the non-fuel side in the substantially cylindrical casing 40. It has the valve body 45 which is a 2nd valve body arrange | positioned along an axis in the side. The case 40 is, for example, a first case part 40a on the non-fuel side and a second case part 40b in which a part of the case is inserted into the inner diameter side of the fuel side of the first case part 40a. Consists of. The inner diameter of the second case portion 40b is smaller than the inner diameter of the first case portion 40a, and the second case portion 40b also serves as the engaging portion 40g. On the non-fuel side and the fuel side of the substantially cylindrical casing 40, external air side hole portions 40c and 40h and fuel supply mechanism side hole portions 40d and 40i are respectively provided.

The valve body 46 has a non-fuel side shaft portion 46a and a fuel supply mechanism side shaft portion 46b, and a large diameter engaging portion 46c is provided on the outer diameter side. Moreover, 46 d of through-holes are provided in the valve body 46 along an axial center. 46 d of through-holes are provided in the non-fuel side, the non-fuel side opening part 46e in which the filter 47 for preventing a foreign material mixing from the non-fuel side, and the fuel side are provided in the valve body, It consists of the fuel supply mechanism side opening part 46g which is a hemispherical recessed part into which the hemispherical shaft part 45a of 45 is inserted, and the connection hole 46f provided between them.

The filter 47 is inserted into the outside air hole 40c, and the fuel supply mechanism side shaft 46b is inserted into the coupling portion 40g. The outer diameter of the fuel supply mechanism side shaft portion 46b is smaller than the inner diameter of the coupling portion 40g, and a gap is formed between the coupling portion 40g and the fuel supply mechanism side shaft portion 46b.

As the non-fuel side of the engaging portion 46c, a spring 48 is provided around the non-fuel side shaft portion 46a, and the valve body 46 is pushed toward the fuel side by the repulsive force of the spring 48. A rubber O-ring 49 is provided around the fuel supply mechanism-side shaft 46b as the fuel side of the coupling portion 46c, and the O-ring 49 is coupled to the coupling portion 46c. It is pressed by the coupling part 40g. As the O-ring 49 is pressed by the coupling portion 46c and the coupling portion 40g in this way, the outflow of the liquid fuel to the non-fuel side between the coupling portion 46c and the coupling portion 40g is suppressed.

The valve body 45 is the same as that shown in FIGS. 5 and 6. 5 and 6, the hemispherical shaft portion 45a is inserted to fit into the hemispherical recess of the fuel supply mechanism side opening 46g. Thus, the hemispherical shaft portion 45a is inserted into the hemispherical concave portion of the fuel supply mechanism side opening 46g so that the liquid fuel flows out from the fuel supply mechanism side opening 46g to the non-fuel side. This is suppressed.

When the internal pressure of the fuel accommodating part 6 becomes below an internal pressure lower limit, as shown in FIG. 11, the valve body 45 pulls in to the fuel side by the internal pressure fall of the fuel accommodating part 6. As the valve body 45 moves to the fuel side, a gap is formed between the fuel supply mechanism side opening portion 46g and the hemispherical shaft portion 45a. At this time, since the pressure on the fuel side is lower than that on the non-fuel side, outside air is introduced into the non-fuel side opening 46e through the filter 47. The outside air introduced into the non-fuel side opening 46e passes through the gap between the fuel supply mechanism side opening 46g and the hemispherical shaft portion 45a, and the outer diameter side of the large diameter portion 45b, and finally the fuel supply mechanism side hole portion. The gap between 40d and the fuel supply mechanism side shaft portion 45c or the fuel supply mechanism side hole 40i is introduced into the fuel storage portion 6. As a result, the internal pressure of the fuel accommodating part 6 rises and becomes higher than a lower internal pressure limit value.

When the internal pressure of the fuel accommodating portion 6 is higher than the lower limit of the internal pressure, the repulsive force of the spring 44 becomes stronger as compared with the strength of drawing the valve body 45 to the fuel side, so that the valve body 45 as shown in FIG. 10. ) Is pressed again to the non-fuel side, and leakage of the liquid fuel to the non-fuel side through the through hole 46d is suppressed.

On the other hand, when the internal pressure of the fuel accommodating part 6 becomes more than an internal pressure upper limit, as shown in FIG. 12, the valve body 46 is pressed to the non-fuel side by the internal pressure rise of the fuel accommodating part 6, and the O-ring 49 And a gap is formed between the coupling portion 40g. A gap is formed between the O-ring 49 and the engaging portion 40g, so that the internal pressure of the fuel accommodating portion 6 is in turn the gap between the fuel supply mechanism side hole portion 40d and the fuel supply mechanism side shaft portion 45c or the fuel. Through the supply mechanism side hole portion 40i, the outer diameter side of the large diameter portion 45b, between the O-ring 49 and the engaging portion 40g, and the outer diameter side of the engaging portion 46c, and the like, 40c, 40h) to the non-fuel side. As a result, the internal pressure of the fuel accommodating part 6 becomes lower than an internal pressure upper limit.

When the internal pressure of the fuel accommodating part 6 becomes lower than an internal pressure upper limit, the repulsive force of the spring 48 becomes strong compared with the intensity | strength which presses the valve body 46 to a non-fuel side, and the valve body by the repulsive force of this spring 48 46 is pressed to the fuel side. As a result, as shown in FIG. 10, between the engaging portion 46c and the engaging portion 40g is blocked by the O-ring 49, and the outflow of the liquid fuel from these to the non-fuel side is suppressed.

Next, another example of the internal pressure adjusting mechanism 4 having the pressure releasing mechanism will be described. 13 to 15 show another example of the internal pressure adjusting mechanism 4 having the pressure releasing mechanism, and the opening on the non-fuel side of the first valve body having a through-hole opening on the side portion while opening on the non-fuel side. The example in which the 2nd valve body was inserted in the is shown. FIG. 13 shows a state when the internal pressure of the fuel accommodating portion 6 is higher than the lower pressure resistance lower limit and lower than the upper pressure resistance upper limit, and neither the pressure resistance adjusting function nor the pressure releasing function is operated. Fig. 14 shows a state when the internal pressure of the fuel accommodating portion 6 is equal to or lower than the lower pressure resistance value and the internal pressure adjusting function is activated. FIG. 15 shows a state when the internal pressure of the fuel container 6 becomes equal to or higher than the internal pressure upper limit and the pressure release function is activated.

As shown in FIG. 13, in this pressure-resistant adjustment mechanism 4, the valve body 50 of the 1st valve body and the valve body 51 of the 2nd valve body are arrange | positioned along the axis in the substantially cylindrical case 40. As shown in FIG. . The case 40 consists of the 1st case part 40a of the non-fuel side, and the 2nd case part 40b in which one part was inserted in the outer diameter side of the fuel side of this 1st case part 40a. The partition member 40j is provided on the inner diameter side of the second case portion 40b as the fuel side of the first case portion 40a. The outside air side hole part 40h is provided in the non-fuel side of the case 40, and the fuel supply mechanism side hole parts 40d and 40i are provided in the fuel side. Moreover, the shaft hole 40k is provided in the shaft center part of the partition material 40j.

On the fuel side of the outside air hole 40h, a filter 52 is provided for preventing foreign matters from mixing during the introduction of outside air and for preventing the outflow of liquid fuel when releasing the internal pressure. Although the filter 52 is not necessarily limited, For example, the gas-liquid separator etc. which permeate only gas and do not permeate liquid are used suitably. As the material of the filter 52, a porous body of polyester resin such as sintered body and porous body of olefin resin such as LDPE (low density polyethylene), HDPE (high density polyethylene) PP (polypropylene), PET (polyethylene terephthalate), PTFE ( Porous bodies of fluorine-based resins such as polydetrafluoroethylene), porous bodies of urethane-based resins such as membranes, polyurethanes, foams and the like are suitably used. Moreover, the detection apparatus 53 which detects the protrusion of the valve body 51 is provided in the position which opposes the non-fuel side of the shaft hole 40k. As the detection apparatus 53, the piezoelectric element etc. which can detect the protrusion by the collision of the valve body 51, etc. are mentioned as a suitable thing, for example.

The valve body 50 has a non-fuel side shaft portion 50a and a fuel supply mechanism side shaft portion 50c, and a large diameter large diameter portion 50b is provided on the outer diameter side of the non-fuel side. 50 d of through-holes are provided in the valve body 50, The through-hole 50d has the non-fuel side opening part 50e opened to the non-fuel side, and the side side opening part 50f opened to the side surface side. Have

The non-fuel side opening 50e is fitted with a valve body 51 for releasing the internal pressure by releasing when the internal pressure of the fuel accommodating portion 6 becomes equal to or higher than the internal pressure upper limit. Thus, by fitting the valve body 51 to the non-fuel side opening 50e, the outflow of the liquid fuel from the non-fuel side opening 50e to the non-fuel side is normally suppressed. In addition, adjustment of an internal pressure upper limit can be performed by adjusting the intensity | strength which fits the valve body 51 with respect to the non-fuel side opening part 50e.

Moreover, the edge part of the non-fuel side of the valve body 51 is inserted in the axial hole 40k of the partition material 40j. The outer diameter (maximum outer diameter) of the valve body 51 is smaller than the inner diameter (minimum inner diameter) of the shaft hole 40k. Since the outer diameter of the valve body 51 is smaller than the inner diameter of the shaft hole 40k, the valve body 51 can move in the shaft hole 40k, and outside air is introduced between them, or internal pressure is reduced. I can free you. Moreover, as long as the valve body 51 can slide in the shaft hole 40k, the outer diameter of the valve body 51 can be made substantially the same as the inner diameter of the shaft hole 40k. In this case, it is preferable that the groove part parallel to an axial direction is provided in the outer surface of the valve body 51 except the part inserted in the non-fuel side opening part 50e. Thus, the groove part parallel to an axial direction is provided in the outer surface of the valve body 51, and even if the outer diameter of the valve body 51 and the inner diameter of the axial hole 40k are substantially the same, it introduces outside air through this groove part, Or release the internal pressure.

The spring 44 is provided in the fuel side of the large diameter part 50b so that the circumference | surroundings of the valve body 50 may be enclosed, and the valve body 50 is pressed by the non-fuel side by the repulsive force of this spring 44. As shown in FIG. A rubber O-ring 55 is provided between the partition member 40j and the valve body 50 around the valve body 51. As the O-ring 55 is pressed by the partition member 401 and the valve body 50 in this way, the inflow of liquid fuel through the outer diameter side of the valve body 50 to the shaft hole 40k is suppressed.

When the internal pressure of the fuel accommodating part 6 becomes below the internal pressure lower limit, as shown in FIG. As the valve body 50 moves to the fuel side, a gap is formed between the partition member 40j and the O-ring 55. At this time, since the pressure of the fuel side is lower than that of the non-fuel side, outside air is introduced into the case 40 from the outside air hole 40h, and the introduced outside air is introduced into the shaft hole 40k and the partition member. Between 40j and O-ring 55, passing through the outer diameter side of the valve body 50, and finally between the fuel supply mechanism side hole part 40d and the fuel supply mechanism side shaft part 50c, or the fuel supply mechanism side It introduce | transduces into the fuel accommodation part 6 from the hole part 40i. As a result, the internal pressure of the fuel accommodating part 6 rises and becomes higher than a lower internal pressure limit value. At this time, since the filter 52 is provided in the fuel side of the outside air hole 40h, the foreign material mixing into the fuel container 6 is suppressed.

When the internal pressure of the fuel accommodating portion 6 becomes higher than the lower internal pressure limit value, the repulsive force of the spring 44 becomes stronger as compared with the strength of drawing the valve body 50 to the fuel side, so that the valve body 50 as shown in FIG. ) Is pressed again to the non-fuel side, and leakage of the liquid fuel through the shaft hole 40k is suppressed.

On the other hand, when the internal pressure of the fuel accommodating portion 6 becomes equal to or higher than the internal pressure upper limit value, as shown in FIG. 15, the valve body 51 is released from the non-fuel side opening 50e due to the internal pressure of the fuel accommodating portion 6 rising. Then, the internal pressure is released from the through hole 50d through the shaft hole 40k, the filter 52, and the outside air hole 40h. At this time, if the filter 52 consists of a gas-liquid separator, since only an internal pressure is released | released from the external air side hole part 40h, and leakage of a liquid fuel is suppressed, it is preferable. In addition, the valve body 51 once canceled with respect to the internal pressure adjusting mechanism 4 does not automatically return to its original position. For this reason, it is preferable to detect the release of the valve body 51 by the detection apparatus 53.

As mentioned above, although the fuel cell 1 of this invention was demonstrated, the position where the pressure-resistant adjustment mechanism 4 is arrange | positioned is not limited to the fuel accommodating part 6. For example, the flow path 7 between the fuel distribution mechanism 5 and the fuel accommodating part 6 may be sufficient. In addition, when arranging the pressure-resistant adjustment mechanism 4 in the flow path 7, the flow path 7 on the fuel receiving portion 6 side of the pump 8 from the viewpoint of suppressing a substantial drop in the substantially liquid feeding capacity of the pump 8. ) Is placed. In addition, this invention is not limited to the said embodiment as it is, In an implementation step, a component can be modified and actualized in the range which does not deviate from the summary. Moreover, various inventions can be formed by appropriate combination of the some component disclosed by the said embodiment. For example, some components may be deleted from all the components disclosed in the embodiment. Moreover, you may combine suitably the component over different embodiment. In addition, even in the liquid fuel supplied to the fuel cell, all of the vapors of the liquid fuel may be supplied, but the present invention can be applied even when a part is supplied in the liquid state.

In the fuel cell according to the aspect of the present invention, an internal pressure adjusting mechanism for introducing outside air is provided in at least a portion of the fuel containing portion at the fuel accommodating portion side than the pump in the fuel supply mechanism. By providing such a pressure-resistant adjustment mechanism, it is possible to secure a substantial liquid feeding capacity of the pump in the fuel supply mechanism, to stabilize the fuel supply to the membrane electrode assembly, to improve the power generation reaction, and to provide excellent output characteristics. It can be done. As described above, the fuel cell according to the aspect of the present invention is excellent in output characteristics, and thus can be effectively used as a power source for various devices and devices.

Claims (10)

A membrane electrode assembly having a fuel electrode, an air electrode, and an electrolyte membrane inserted and held by the fuel electrode and the air electrode; A fuel supply mechanism having a fuel receiving portion connected to a fuel distribution mechanism disposed on the fuel electrode side of the membrane electrode assembly via a flow path having a pump; A fuel cell, characterized in that it is provided in at least a portion of the fuel containing portion more than the pump of the fuel supply mechanism and introduces an outside pressure when the internal pressure of the fuel containing portion decreases. The method of claim 1, The pressure resistant mechanism is operated when the operating pressure is 0.02 MPa or more lower than atmospheric pressure. The method of claim 1, The internal pressure adjusting mechanism blocks a substantially cylindrical case having a fuel supply mechanism side hole portion provided on the fuel supply mechanism side and an outside air side hole portion provided on a portion opposite to the fuel supply mechanism side, and the outside air hole portion. And a valve body which is disposed in the case so as to move to open the outside air-side hole by using the internal pressure drop of the fuel containing portion. The method of claim 1, The pressure resistant mechanism has a pressure releasing mechanism for releasing the pressure when the internal pressure of the fuel containing portion rises. The method of claim 4, wherein The pressure release mechanism is operated when the operating pressure is 0.3 MPa or more. The method of claim 4, wherein An internal pressure adjusting mechanism having the pressure release mechanism includes a substantially cylindrical case having a fuel supply mechanism side hole provided on the fuel supply mechanism side and an outside air side hole portion provided on a portion opposite to the fuel supply mechanism side; A fuel cell comprising a pair of valve bodies disposed along a shaft center in a case. The method of claim 6, Among the pair of valve bodies, the first valve body disposed on the side opposite to the fuel supply mechanism side has a through hole along its axis, and the second valve body disposed on the fuel supply mechanism side has a A fuel cell, characterized in that arranged to block the opening on the fuel supply mechanism side. The method of claim 7, wherein And a filter for suppressing foreign matter from entering the through hole in an opening on the side opposite to the fuel supply mechanism side in the through hole of the first valve element. The method of claim 6, The first valve body disposed on the fuel supply mechanism side of the pair of valve bodies has a through hole that opens on the side opposite to the fuel supply mechanism side and opens to the side portion, and is opposite to the fuel supply mechanism side. And a second valve body disposed in the fuel cell is inserted into an opening opened on the side opposite to the fuel supply mechanism side of the through hole. The method of claim 6, The fuel cell is provided with a filter for suppressing the outflow of the liquid fuel to the outside of the case so as to cover the outside air side hole.

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