JP2010060003A - Pressure regulating valve for fuel cell, and fuel cell using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure regulating valve for a fuel cell, simplified in structure and reduced in the number of parts item, possible to be miniaturized, and excellent in productivity. <P>SOLUTION: This pressure regulating valve for a fuel cell has a valve chamber 41 and a valve element 42 housed in the valve chamber 41, and is installed in a fuel supply mechanism 3 of the fuel cell 1 to regulate the inner pressure thereof. The valve element 42 has a cylindrical member 46 and an elastic member 47, which has a frame part 47a arranged in one end part of the cylindrical member 46 in the surface of the end part, a fitting part 47b to be fitted in the cylindrical member 46, and a holding part 47d holding the fitting part 47b freely to move in the frame part 47a and formed with a hole part 47c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell pressure adjustment valve that is attached to a fuel supply mechanism of a fuel cell and adjusts an internal pressure, and a fuel cell using the fuel cell pressure adjustment valve.

  In recent years, attempts have been made to use a fuel cell as a power source for portable electronic devices such as notebook computers and mobile phones so that they can be used for a long time without being charged. A fuel cell has a feature that it can generate electric power simply by supplying fuel and air, and can generate electric power continuously for a long time if fuel is replenished. For this reason, if the fuel cell can be reduced in size, it can be said that the system is extremely advantageous as a power source for portable electronic devices.

  A direct methanol fuel cell (DMFC) is promising as a power source for portable electronic devices because it can be miniaturized and the fuel can be easily handled. As the liquid fuel supply method in the DMFC, there are known an active method such as a gas supply type and a liquid supply type, and a passive method such as an internal vaporization type in which the liquid fuel in the fuel container is vaporized inside the cell and supplied to the fuel electrode. It has been.

  Among these, a passive system such as an internal vaporization type is particularly advantageous for downsizing of the DMFC. In the passive DMFC, for example, a structure is proposed in which a membrane electrode assembly (fuel cell) having a fuel electrode, an electrolyte membrane, and an air electrode is disposed on a fuel containing portion made of a resin box-like container ( For example, see Patent Document 1). When the fuel vaporized from the fuel container is directly supplied to the fuel cell, it is important to improve the output controllability of the fuel cell, but the current passive DMFC does not always have sufficient output controllability. .

On the other hand, it has been studied to connect a fuel cell of DMFC and a fuel storage part via a flow path (see Patent Documents 2 to 4). By supplying the liquid fuel supplied from the fuel storage unit 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. Moreover, in patent document 3, the liquid fuel is supplied with a pump from a fuel accommodating part to a flow path. Patent Document 3 also describes that an electric field forming means for forming an electroosmotic flow in the flow path is used instead of the pump. Patent Document 4 describes that liquid fuel and the like are supplied using an electroosmotic pump.
International Publication No. 2005/112172 Pamphlet JP 2005-518646 A JP 2006-089552 A US Patent Publication No. 2006/0029851

  Although it is effective to provide a pump in a fuel cell to which a circulation structure is applied, if fuel is not circulated as in the case of passive DMFC, even if a pump is provided, the fuel consumption will only increase and a sufficient output will not necessarily be obtained. Can't get. That is, when the liquid fuel in the fuel storage unit is supplied to the fuel cells by the pump, the pressure in the fuel storage unit decreases due to the decrease of the liquid fuel accompanying power generation, and the substantial liquid feeding capacity of the pump decreases. For this reason, the amount of fuel supplied to the fuel cells decreases, and a sufficient output cannot always be obtained.

  On the other hand, when the fuel cell is left in a car in the summer, for example, it becomes an abnormally high temperature state, and the liquid fuel in the fuel storage part evaporates, and the internal pressure may rise excessively. If the internal pressure rises excessively, the fuel storage portion may be damaged and liquid fuel may leak out.

  For this reason, the fuel cell is preferably provided with an internal pressure adjusting means that introduces and raises the outside air when the internal pressure is reduced, and discharges and reduces the inside air when the internal pressure is raised. However, when the introduction of the outside air and the discharge of the inside air are performed by one internal pressure adjusting means, for example, an internal pressure adjusting means using a valve mechanism, the structure becomes complicated, the number of parts increases, and the size increases. There is a risk.

  Since fuel cells are being reduced in size for use as a power source for portable electronic devices and the like, the fuel storage portion and the like are also being reduced in size accordingly. It is preferable that the internal pressure adjusting device is also miniaturized so that it can be attached to the housing or the like. From the viewpoint of miniaturization and manufacturability, it is preferable that the structure is simple and the number of parts is small.

  The present invention has been made to solve the above-described problems, and is a fuel cell pressure regulating valve that is mounted on a fuel supply mechanism of a fuel cell and is used for adjusting an internal pressure. An object of the present invention is to provide a pressure regulating valve for a fuel cell that is small in size, can be miniaturized, and is excellent in productivity. Another object of the present invention is to provide a fuel cell comprising the fuel cell pressure regulating valve.

  The pressure regulating valve for a fuel cell according to the present invention has a valve chamber and a valve main body accommodated in the valve chamber, and is used for adjusting an internal pressure by being attached to a fuel supply mechanism of the fuel cell. A pressure regulating valve for use, wherein the valve body is fitted into the tubular member, a frame portion disposed on one end portion of the tubular member, disposed on a surface of the end portion, and the tubular member And an elastic member having a holding part in which the fitting part is movably held in the frame part and a hole part is formed.

  The pressure adjustment valve for a fuel cell according to the present invention preferably has a pressing elastic body that presses the valve body toward the elastic member. The valve chamber includes a hole formed in the fuel storage portion of the fuel supply mechanism and a cylindrical fixing member fixed so as to be fitted into the hole of the fuel storage portion. It is preferable. Furthermore, it is preferable that the hole portion of the fuel storage portion is composed of a small diameter portion formed on the inner side of the fuel storage portion and a large diameter portion formed on the outer side of the small diameter portion. .

  The valve main body may be disposed, for example, such that the elastic member side is an external side of the fuel supply mechanism, or, for example, is disposed such that the elastic member side is an internal side of the fuel supply mechanism. Also good.

  The fuel cell of the present invention has a fuel electrode, an air electrode, a membrane electrode assembly having an electrolyte membrane sandwiched between the fuel electrode and the air electrode, and a fuel storage part for storing liquid fuel, A fuel supply mechanism for supplying fuel to the fuel electrode of the membrane electrode assembly; and a fuel cell pressure adjustment valve mounted on the fuel supply mechanism, wherein the fuel cell pressure adjustment valve comprises: It is the pressure regulating valve for a fuel cell according to the present invention described above.

  According to the present invention, in a pressure adjustment valve for a fuel cell having a valve chamber and a valve main body accommodated in the valve chamber, the valve main body is disposed at the cylindrical member and at one end of the cylindrical member. And the elastic member is further moved to the frame portion disposed on the surface of the end portion of the cylindrical member, the fitting portion fitted into the cylindrical member, and the fitting portion moved to the frame portion. By holding the holding portion in a possible manner and having a holding portion in which a hole is formed, the structure can be simplified, the number of parts can be reduced, and the size can be reduced and the productivity can be improved.

  In addition, according to the present invention, by using such a fuel cell pressure regulating valve for the fuel cell, the output characteristics are improved, and the fuel supply mechanism is prevented from being damaged and excellent in reliability. Therefore, it can be made excellent in manufacturability.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of the fuel cell of the present invention. A fuel cell 1 shown in FIG. 1 includes a fuel cell 2 as a membrane electrode assembly constituting an electromotive unit, a fuel supply mechanism 3 for supplying fuel to the fuel cell 2, and a fuel supply mechanism 3. The fuel cell pressure regulating valve (hereinafter simply referred to as a pressure regulating valve) 4 is mainly configured.

  The fuel supply mechanism 3 includes, for example, a fuel distribution mechanism 5, a fuel storage unit 6 that stores liquid fuel, a flow path 7 that connects the fuel distribution mechanism 5 and the fuel storage unit 6, and the flow path 7. The pump 8 is made up of. The pressure adjustment valve 4 is provided in, for example, the fuel storage portion 6 in such a fuel supply mechanism 3.

  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) 16 having a cathode catalyst layer 14 and a cathode gas diffusion layer 15. And a membrane electrode assembly (MEA) composed of a proton (hydrogen ion) conductive electrolyte membrane 17 sandwiched between 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 simple substance of a platinum group element such as Pt, Ru, Rh, Ir, Os, and Pd, and an alloy containing the platinum group element. For the anode catalyst layer 11, it is preferable to use Pt—Ru, Pt—Mo, or the like having strong resistance to methanol, carbon monoxide, or the like. Pt, Pt—Ni or the like is preferably used for the cathode catalyst layer 14. However, the catalyst is not limited to these, and various substances having catalytic activity can be used. The catalyst may be either a supported catalyst using a conductive support such as a carbon material or an unsupported catalyst.

  Examples of the proton conductive material constituting the electrolyte membrane 17 include fluorine-based resins (Nafion (trade name, manufactured by DuPont) and Flemion (trade name, manufactured by Asahi Glass Co., Ltd.) such as a perfluorosulfonic acid polymer having a sulfonic acid group. Etc.), organic materials such as hydrocarbon resins having sulfonic acid groups, or inorganic materials such as tungstic acid and phosphotungstic acid. However, the proton conductive electrolyte membrane 17 is not limited to these.

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

  A conductive layer is laminated on the anode gas diffusion layer 12 and the cathode gas diffusion layer 15 as necessary. As these conductive layers, for example, a porous layer (for example, a mesh) made of a conductive metal material such as Au or Ni, a thin film or a foil, or a conductive metal material such as stainless steel (SUS) or a highly conductive material such as Au. A metal-coated composite material or the like is used. Rubber O-rings 19 are interposed between the electrolyte membrane 17, the fuel distribution mechanism 5 and the cover plate 18, thereby preventing fuel leakage or oxidant leakage from the fuel cell (MEA) 2. is doing.

  Although not shown, the cover plate 18 has an opening for taking in air as an oxidant. A moisture retaining layer and a surface layer are disposed between the cover plate 18 and the cathode 16 as necessary. The moisturizing layer is impregnated with a part of the water generated in the cathode catalyst layer 14 to suppress the transpiration of water and promote uniform diffusion of air to the cathode catalyst layer 14. The surface layer adjusts the amount of air taken in, and has a plurality of air inlets whose number, size, etc. are adjusted according to the amount of air taken in.

  Liquid fuel corresponding to the fuel cells 2 is stored in the fuel storage unit 6. Examples of the liquid fuel include methanol fuels such as aqueous methanol solutions of various concentrations and pure methanol. The liquid fuel is not necessarily limited to methanol fuel. The liquid fuel may be, for example, an ethanol fuel such as an ethanol aqueous solution or pure ethanol, a propanol fuel such as a propanol aqueous solution or pure propanol, a glycol fuel such as a glycol aqueous solution or pure glycol, dimethyl ether, formic acid, or other liquid fuel. In any case, liquid fuel corresponding to the fuel cell 2 is stored in the fuel storage unit 6.

  For example, polypropylene (PP), polyphenylene sulfide (PPS), high density polyethylene (HDPE), polystyrene (PS), polyetheretherketone (PEEK: Victorex) (Trademark), liquid crystal polymer (LCP), polybutylene terephthalate (PBT), polyacetal (POM), etc. Further, as a resin material having methanol resistance and transparency, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), cyclic It is composed of olefin copolymer (COC), cycloolefin polymer (COP), polymethylpentene (TPX), polyphenylsulfone (PPSU), polyethersulfone (PES) and the like.

  A fuel distribution mechanism 5 is disposed on the anode 13 side of the fuel battery cell 2. The fuel distribution mechanism 5 is connected to the fuel storage section 6 via a liquid fuel flow path 7 such as a pipe provided with a pump 8 in the middle. Liquid fuel is introduced into the fuel distribution mechanism 5 from the fuel storage portion 6 through such a flow path 7. The flow path 7 is not limited to piping independent of the fuel distribution mechanism 5 and the fuel storage unit 6. For example, when the fuel distribution mechanism 5 and the fuel storage unit 6 are stacked and integrated, a liquid fuel flow path connecting them may be used. The fuel distribution mechanism 5 only needs to be connected to the fuel storage unit 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 liquid fuel flows through the flow path 7, and a plurality of fuel outlets 5b through which liquid fuel and its vaporized components are discharged. The fuel distribution plate 5c having Inside the fuel distribution plate 5c, as shown in FIG. 1, there is provided a gap portion 5d serving as a liquid fuel passage guided from the fuel injection port 5a. The plurality of fuel discharge ports 5b are directly connected to gaps 5d that function as fuel passages.

  The liquid fuel introduced from the fuel inlet 5a into the fuel distribution plate 5c enters the gap 5d, and is guided to the plurality of fuel discharge ports 5b via the gap 5d functioning as the fuel passage. For example, a gas-liquid separator (not shown) that transmits only the vaporized component of the liquid fuel and does not transmit the liquid component may be disposed in the plurality of fuel discharge ports 5b. As a result, the vaporized component of the liquid fuel is supplied to the anode 13 of the fuel cell 2. The gas-liquid separator may be installed as a gas-liquid separation membrane or the like between the fuel distribution mechanism 5 and the anode 13. The vaporized component of the liquid fuel is discharged from a plurality of fuel discharge ports 5b toward a plurality of locations on the anode 13.

A plurality of fuel discharge ports 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 discharge port 5b may be one or more, but in order to equalize the fuel supply amount in the plane of the fuel cell 2, there are 0.1 to 10 pieces / cm ² of the fuel outlet 5b It is preferable to form so as to. If the number of fuel discharge port 5b is less than 0.1 or / cm ^2, it can not be sufficiently uniform the fuel supply amount to the fuel cell 2. Even if the number of the fuel discharge ports 5b exceeds 10 / cm ² , no further effect can be obtained.

The fuel released from the fuel distribution mechanism 5 is supplied to the anode 13 of the fuel cell 2 as described above. In the fuel cell 2, the fuel diffuses through the anode gas diffusion layer 12 and is supplied to the anode catalyst layer 11. When methanol fuel is used as the liquid fuel, an internal reforming reaction of methanol shown in the following formula (1) occurs in the anode catalyst layer 11. When pure methanol is used as the methanol fuel, the water generated in the cathode catalyst layer 14 or the water in the electrolyte membrane 17 is reacted with methanol to cause the internal reforming reaction of the formula (1). Alternatively, the internal reforming reaction is caused by another reaction mechanism that does not require water.
_{CH 3 OH + H 2 O →} CO 2 + 6H + + 6e - ... (1)

The electrons (e ⁻ ) generated by this reaction are guided to the outside via a current collector, and are guided to the cathode 16 after operating a portable electronic device or the like as so-called electricity. Further, (1) a proton (H ⁺⁾ generated by the internal reforming reaction of the formula is introduced to the cathode 16 via the electrolyte membrane 17. Air is supplied to the cathode 16 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 in accordance with the following equation (2), and water is generated along with this reaction.
6e ⁻ + 6H ⁺ + (3/2) O ₂ → 3H ₂ O (2)

  The pump 8 is not a circulation pump that circulates fuel, but is a fuel supply pump that sends liquid fuel from the fuel storage unit 6 to the fuel distribution mechanism 5 to the last. By supplying liquid fuel with such a pump 8 when necessary, the controllability of the fuel supply amount can be improved. The fuel supplied from the fuel distribution mechanism 5 to the fuel cells 2 is used for the power generation reaction, and is not circulated thereafter and returned to the fuel storage unit 6. Since the fuel cell 1 shown in FIG. 1 does not circulate the fuel, the fuel cell 1 is different from the conventional active method and does not impair the downsizing of the apparatus. Further, the pump 8 is used for supplying the liquid fuel, which is different from a pure passive method such as a conventional internal vaporization type, and is therefore called a semi-passive method, for example.

  The type of the pump 8 is not particularly limited, but a rotary vane pump, an electroosmotic flow pump, a diaphragm pump, from the viewpoint that a small amount of liquid fuel can be sent with good controllability and can be reduced in size and weight. It is preferable to use an ironing pump or the like. A rotary vane pump feeds liquid by rotating a wing with a motor. The electroosmotic flow pump uses a sintered porous material such as silica that causes an electroosmotic flow phenomenon. The diaphragm pump is a pump that feeds liquid by driving the diaphragm with an electromagnet or piezoelectric ceramics. The squeezing pump presses a part of the flexible fuel flow path and squeezes the fuel. Among these, it is more preferable to use an electroosmotic pump or a diaphragm pump having piezoelectric ceramics from the viewpoint of driving power, size, and the like.

  Since the main object of the fuel cell 1 is a small electronic device, the liquid feeding capability of the pump 8 is preferably in the range of 10 μL / min to 1 mL / min. When the liquid feeding capacity exceeds 1 mL / min, the amount of liquid fuel fed at one time becomes too large, and the stop time of the pump 8 occupying the entire operation period becomes long. For this reason, fluctuations in the amount of fuel supplied to the fuel cells 2 increase, and as a result, fluctuations in output increase. 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, fluctuations in the fuel supply amount cannot be sufficiently suppressed, and This will increase the size of the device.

  On the other hand, when the liquid feeding capacity of the pump 8 is less than 10 μL / min, there is a risk of insufficient supply capacity when the amount of fuel consumption increases as when the apparatus is started up. As a result, the starting characteristics of the fuel cell 1 are deteriorated. From such a point, it is preferable to use the pump 8 having a liquid feeding capacity in the range of 10 μL / min to 1 mL / min. The pumping capacity of the pump 8 is more preferably in the range of 10 to 200 μL / min. In order to stably realize such a liquid feeding amount, it is preferable to apply an electroosmotic flow pump or a diaphragm pump to the pump 8.

  The pressure adjustment valve 4 is provided so that the internal pressure of the fuel storage portion 6 (hereinafter simply referred to as internal pressure) is within an appropriate range. That is, when the internal pressure falls below the appropriate range, for example, in order to restore the substantial liquid feeding capability of the pump 8, the external pressure is introduced to increase the internal pressure, and when the internal pressure becomes higher than the proper range, the fuel In order to suppress breakage of the accommodating portion 6, it is provided for exhausting the inside air and reducing the internal pressure. In addition, when the internal pressure is within the appropriate range, the entire body is closed to prevent foreign matter from entering the fuel storage unit 6 from the outside, and the outflow of liquid fuel from the fuel storage unit 6 to the outside. Suppress.

  Here, the appropriate range of the internal pressure can be appropriately selected according to the liquid feeding capacity of the pump 8, the strength of the fuel storage unit 6, and the like. For example, the lower limit is a pressure lower by about 0.01 MPa than the atmospheric pressure. Yes, the upper limit is about 0.6 MPa higher than the atmospheric pressure. When the lower limit is a low pressure lower than 0.01 MPa with respect to the atmospheric pressure, for example, the substantial liquid feeding capacity of the pump 8 may be reduced, and the output characteristics of the fuel cell 1 may become unstable. When the pressure is higher than 0.6 MPa with respect to the atmospheric pressure, for example, the fuel storage unit 6 or the like may be damaged, and the liquid fuel may flow out.

  FIG. 3 is a cross-sectional view showing a first embodiment of the pressure regulating valve 4 of the present invention, and shows a case where the internal pressure is within an appropriate range. In each of the drawings showing the pressure regulating valve 4 below, the upper side in the drawing is shown as the outside of the fuel storage unit 6, and the lower side of the drawing is shown as the inside of the fuel storage unit 6. In the following description, the external side of the fuel storage unit 6 is simply referred to as the external side, and the internal side of the fuel storage unit 6 is simply referred to as the internal side.

  The pressure adjustment valve 4 includes a valve chamber 41 and a valve main body 42 accommodated in the valve chamber 41. Further, the pressure adjusting valve 4 has a pressing elastic body 43 such as a spring for pressing the valve main body 42.

  The pressing elastic body 43 is preferably subjected to surface treatment in order to be disposed in the fuel flow path and come into contact with the liquid fuel. Specifically, a stainless steel spring that has been passivated to enhance corrosion resistance is preferable. The surface treatment is not limited to the passivation treatment, and a precious metal plating such as gold or a resin coating such as a fluorine-based resin is preferably used. Also, a spring using carbon as a material can be used.

  The valve chamber 41 is formed by using, for example, the outer wall of the container of the fuel storage unit 6, and specifically, a hole 61 provided in the outer wall of the container, and is fixed so as to be fitted into the hole 61 from the outside. And a fixing member 44.

  The hole 61 serves as a gas flow path and mainly constitutes the valve chamber 41. Specifically, the hole 61a is formed on the inner side of the outer wall of the container, and the outside of the inner hole 61a. The outer hole 61b is formed on the side, and the outer hole 61b mainly constitutes the valve chamber 41.

  The fixing member 44 has a cylindrical shape, and is formed, for example, at an insertion portion 44a to be inserted into the outer hole portion 61b, on the outer side of the insertion portion 44a, and to be caught by an edge portion of the outer hole portion 61b. It has a large-diameter portion 44b and a cylindrical hole 44c that passes therethrough. The insertion portion 44a holds the valve body 42 from the outside so as to be held in the outer hole 61b, and the large-diameter portion 44b is hooked on the edge of the outer hole 61b so that the entire outer hole 61b is held. It is provided not to be buried in. Further, the cylindrical hole 44c is provided to provide a gas flow path.

  For example, polypropylene (PP), polyphenylene sulfide (PPS), high density polyethylene (HDPE), polystyrene (PS), polyether ether ketone (PEEK: Trademark of Victorex Corporation) is used as the fixing member 44 as a resin material having methanol resistance. ), Liquid crystal polymer (LCP), polybutylene terephthalate (PBT), polyacetal (POM), etc. Further, as a resin material having methanol resistance and transparency, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), cyclic olefin It is composed of a copolymer (COC), a cycloolefin polymer (COP), polymethylpentene (TPX), polyphenylsulfone (PPSU), polyethersulfone (PES) and the like. In particular, the fixing member 44 is preferably made of the same material as that of the fuel storage unit 6 because it can be fixed to the fuel storage unit 6 by ultrasonic bonding or the like.

  On the other hand, the valve main body 42 is composed of a cylindrical member 46 and an elastic member 47 disposed at an end portion on the outer side of the cylindrical member 46, and the whole is directed to the outer side, that is, the elastic member 47 side. It is pressed by the pressing elastic body 43.

  The cylindrical member 46 mainly constitutes the valve body 42, and a large-diameter portion 46a is formed on the outer side, that is, the elastic member 47 side, and a small-diameter portion 46b is formed on the opposite end portion, and penetrates the whole. Thus, the shaft hole 46c is formed.

  The cylindrical member 46 is made of, for example, polypropylene (PP), polyphenylene sulfide (PPS), high density polyethylene (HDPE), polystyrene (PS), polyether ether ketone (PEEK: Victorex) as a resin material having methanol resistance. (Trademark), liquid crystal polymer (LCP), polybutylene terephthalate (PBT), polyacetal (POM), etc. Further, as a resin material having methanol resistance and transparency, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), cyclic It is composed of olefin copolymer (COC), cycloolefin polymer (COP), polymethylpentene (TPX), polyphenylsulfone (PPSU), polyethersulfone (PES) and the like. In particular, the cylindrical member 46 is preferable because a material different from that of the fixing member 44 can be used to prevent unintentional tight fixing to the fixing member 44.

  The large diameter portion 46 a is provided for pressing the elastic member 47, particularly the frame portion 47 a, and for pressing by the pressing elastic body 43. Moreover, the small diameter part 46b is provided in order to move the cylindrical member 46, ie, the valve main body 42 appropriately along the axial direction by being inserted into the inner hole part 61a. A gap is provided between the inner hole 61a and the small-diameter portion 46b so as to be a gas flow path. Furthermore, the shaft hole 46c is also provided to provide a gas flow path.

  The elastic member 47 is integrally formed from, for example, an elastic material, and includes a frame portion 47a disposed on the surface of the outer end portion of the cylindrical member 46, the cylindrical member 46, specifically, a shaft hole. The fitting part 47b fitted in 46c, and the holding part 47d which hold | maintains the fitting part 47b to the frame part 47a so that a movement is possible, and the hole 47c is formed.

  The frame portion 47a seals between the cylindrical member 46 and the fixing member 44, specifically, the opposite end portions (edge portions) thereof, and holds the fitting portion 47b via the holding portion 47d. Is provided to do. The fitting portion 47b is provided to open and close the shaft hole 46c by being fitted into the shaft hole 46c. Furthermore, the holding portion 47d is provided to hold the fitting portion 47b on the frame portion 47a. Moreover, the hole 47c is provided to provide a gas flow path when the shaft hole 46c is opened.

  The elastic member 47 is made of, for example, ethylene-propylene-diene rubber (EPDM) having methanol resistance. However, for example, the material of the movable film constituting the holding portion 47d is not limited to EPDM, but silicone rubber (VMQ), fluorosilicone rubber (FVMQ), fluorine rubber (FKM), nitrile rubber (NBR), hydrogenated nitrile rubber ( HNBR) is preferably used. Further, the materials listed above are preferably used for the material of the movable film. For the frame portion 47a, a resin having methanol resistance, such as polyetherimide (PEI), polyimide (PI), polyetheretherketone (PEEK: Victor). Rex Co., Ltd.), polyphenylene sulfide (PPS), or other film may be used, and a lip-shaped frame portion 47a may be formed on the film.

  4 is an external view showing an example of the elastic member 47. FIG. 4A shows the cylindrical member 46 side, and FIG. 4B shows the opposite side.

  For example, as shown in FIG. 4A, the frame 47a has, for example, a substantially annular appearance, and is generally sealed between the tubular member 46 and the fixing member 44 in the circumferential direction. Be able to. The frame portion 47a has a circular shape as shown in FIG. 3, for example, so that the space between the tubular member 46 and the fixing member 44 can be more reliably sealed. Yes. Further, the fitting portion 47b is formed, for example, at the axial center portion of the frame portion 47a, and has a substantially conical appearance so that it can be easily inserted and positioned in the shaft hole 46c.

  A groove portion 47e extending in the axial direction, for example, is formed on the side surface portion of the fitting portion 47b so that gas can be easily circulated. The groove portion 47e is not formed on the large diameter side of the fitting portion 47b, and an annular portion where the groove portion 47e is not formed is in close contact with the shaft hole 46c to form a seal portion 47f. . The holding portion 47d is formed in a film shape so as to hold the fitting portion 47b on the frame portion 47a. For example, four holes 47c are formed at equal intervals around the fitting portion 47b. Has been.

  According to such a pressure regulating valve 4, when the internal pressure is within an appropriate range, as shown in FIG. 3, the frame portion 47a and the fitting portion 47b are connected by the holding portion 47d. The fitting portion 47b is fitted into the shaft hole 46c, and the shaft hole 46c is closed. Further, the entire valve body 42 with the shaft hole 46c closed is pressed to the outside by the pressing elastic body 43, so that the valve body 42 comes into contact with the cylinder hole 44c and the cylinder hole 44c is closed. Is done. Thereby, intrusion of foreign matter from the outside is suppressed and outflow of liquid fuel from the inside is suppressed.

  On the other hand, when the internal pressure falls below the lower limit of the appropriate range, as shown in FIG. 5, the valve main body 42 is adjusted using the difference between the internal pressure and the external pressure (pressure outside the fuel storage unit 6; atmospheric pressure). The cylinder hole 44c can be opened by moving to the inner side. As a result, outside air is introduced from the cylindrical hole 44c between the outer hole 61b and the outer diameter side of the valve body 42, and this outside air passes through the inner hole 61a from the gap between the inner hole 61a and the small diameter part 46b. It can be introduced into the fuel storage section 6. As a result, the internal pressure of the fuel storage unit 6 increases, and the internal pressure can be returned to the appropriate range. After the internal pressure has returned to the proper range in this way, the whole of the valve body 42 is again pressed outward by the pressing elastic body 43, so that the cylindrical hole 44c is closed as shown in FIG. Is done.

  Also, when the internal pressure exceeds the upper limit of the appropriate range, as shown in FIG. 6, the fitting portion 47b is moved to the outside with respect to the frame portion 47a using the difference between the internal pressure and the external pressure, The shaft hole 46c can be opened by disengaging the fitting portion 47b, particularly the seal portion 47f, from the shaft hole 46c. Thereby, the inside air of the fuel storage portion 6 can be discharged to the outside through the inner hole portion 61a, the shaft hole 46c, the hole portion 47c, and the cylindrical hole 44c in this order. As a result, the internal pressure of the fuel storage unit 6 is reduced, and the internal pressure can be returned to an appropriate range. After the internal pressure has returned to the appropriate range in this way, the fitting portion 47b moves to the inside so as to be pulled by the holding portion 47d connected to the frame portion 47a again, and is fitted into the shaft hole 46c. When the portion 47b is fitted, the shaft hole 46c is closed as shown in FIG.

  The pressure adjusting valve 4 is configured so that when the internal pressure falls below the lower limit of the appropriate range, the valve main body 42 can move to the inner side due to the difference between the internal pressure and the external pressure. The repulsive force is adjusted. Further, when the internal pressure exceeds the upper limit value of the appropriate range, the fitting portion 47b can be moved to the outside with respect to the frame portion 47a using the difference between the internal pressure and the external pressure, that is, The contraction force of the holding portion 47d is adjusted so that the fitting portion 47b is detached from the shaft hole 46c. Such adjustment of the contraction force of the holding portion 47d can be performed by appropriately selecting, for example, the constituent material, thickness, the number of the hole portions 47c, and the like of the holding portion 47d.

Next, the 2nd form of the pressure regulation valve 4 of this invention is demonstrated.
FIG. 7 is a sectional view showing the pressure regulating valve 4 of the second embodiment, and shows a case where the internal pressure is within an appropriate range. In the pressure adjusting valve 4, the direction of the valve main body 42 including the pressing elastic body 43 is opposite to that of the pressure adjusting valve 4 of the first embodiment.

  That is, the valve body 42 contacts the elastic member 47 side around the inner hole portion 61a, specifically, a step formed between the inner hole portion 61a and the outer hole portion 61b, and the small diameter portion 46b side. It arrange | positions so that it may insert in the cylinder hole 44c. The entirety is pressed by the pressing elastic body 43 toward the inside, that is, the elastic member 47 side. A gap is provided between the cylindrical hole 44c and the small-diameter portion 46b so as to be a gas flow path.

  In this pressure adjustment valve 4, the direction of the valve main body 42 including the pressing elastic body 43 is reversed with respect to the pressure adjustment valve 4 of the first embodiment, whereby the internal pressure adjustment method is also the pressure of the first embodiment. The adjustment valve 4 is opposite to the adjustment valve 4. Specifically, the adjustment when the internal pressure falls below the appropriate range is performed by opening and closing the shaft hole 46 c by the elastic member 47, and the adjustment when the internal pressure exceeds the appropriate range is performed on the valve. This is performed by opening and closing the inner hole 61 a by the main body 42 and the pressing elastic body 43.

  Therefore, in the pressure adjusting valve 4, when the internal pressure falls below the lower limit value of the appropriate range, the fitting portion 47b moves to the inner side with respect to the frame portion 47a using the difference between the internal pressure and the external pressure. In other words, the contraction force of the holding portion 47d is adjusted so that the fitting portion 47b is detached from the shaft hole 46c. Further, when the internal pressure exceeds the upper limit value of the appropriate range, the repulsive force of the pressing elastic body 43 is adjusted so that the valve main body 42 can move to the outside due to the difference between the internal pressure and the external pressure. Yes.

  In the pressure adjusting valve 4, the direction of the valve body 42 including the pressing elastic body 43 is changed, and the contraction force of the holding portion 47 d of the elastic member 47 and the repulsion of the pressing elastic body 43 are adjusted accordingly. Except for changing the force, the configuration of the valve chamber 41 and the configuration of the valve body 42 are the same as those of the pressure regulating valve 4 of the first embodiment.

  According to the pressure regulating valve 4 as described above, when the internal pressure is within an appropriate range, the frame portion 47a and the fitting portion 47b are connected by the holding portion 47d. The shaft hole 46c is closed by being fitted into the 46c. Further, the entire valve body 42 with the shaft hole 46c closed is pressed to the inner side by the pressing elastic body 43, so that the valve body 42 comes into contact with the inner hole 61a and the inner hole 61a. Is blocked. Thereby, intrusion of foreign matter from the outside is suppressed and outflow of liquid fuel from the inside is suppressed.

  On the other hand, when the internal pressure falls below the lower limit of the appropriate range, for example, as shown in FIG. 8, the fitting portion 47b is moved to the inner side with respect to the frame portion 47a using the difference between the internal pressure and the external pressure. The shaft hole 46c can be opened by disengaging the fitting portion 47b, particularly the seal portion 47f, from the shaft hole 46c. Thereby, outside air can be introduced into the fuel accommodating part 6 through the cylindrical hole 44c, the shaft hole 46c, the hole part 47c, and the inner hole part 61a. As a result, the internal pressure of the fuel storage unit 6 increases, and the internal pressure can be returned to the appropriate range. After the internal pressure has returned to the appropriate range in this way, the fitting portion 47b moves to the outside so as to be pulled by the holding portion 47d connected to the frame portion 47a again, and fitted into the shaft hole 46c. When the portion 47b is fitted, the shaft hole 46c is closed as shown in FIG.

  If the internal pressure exceeds the upper limit of the appropriate range, for example, as shown in FIG. 9, the valve body 42 is moved to the outside side using the difference between the internal pressure and the external pressure to open the inner hole 61a. Can be made. As a result, the inside air in the fuel accommodating portion 6 is discharged from the inner hole 61a between the outer hole 61b and the outer diameter side of the valve body 42, and further to the outside through the gap between the cylindrical hole 44c and the small diameter portion 46b. And can be discharged. As a result, the internal pressure of the fuel storage unit 6 is reduced, and the internal pressure can be returned to an appropriate range. After the internal pressure has returned to the appropriate range in this way, the entire valve body 42 is pressed again toward the inner side by the pressing elastic body 43, so that the inner hole 61a is formed as shown in FIG. Blocked.

  As described above, the first embodiment and the second embodiment of the pressure regulating valve 4 of the present invention have been described as examples, but it is usually preferable to use the pressure regulating valve 4 of the first embodiment. By using the pressure regulating valve 4 of the first embodiment, the adjustment when the internal pressure falls below the appropriate range can be performed quickly and precisely, and for example, a substantial decrease in the liquid feeding capacity of the pump 8 can be effectively reduced. The output characteristics of the fuel cell 1 can be further improved.

  That is, the pressure is adjusted using the pressing elastic body 43 such as a spring, and the elastic member 47, specifically, the fitting portion 47b held by the frame portion 47a via the holding portion 47d is used. In the case where the pressure is adjusted, the pressure using the pressing elastic body 43 such as a spring can be adjusted quickly and accurately. For this reason, according to the pressure control valve 4 of the 1st form used for adjustment when the internal pressure falls below the proper range, the pressure elastic valve 43 such as a spring is adjusted when the internal pressure falls below the proper range. Can be performed quickly and accurately, for example, a substantial decrease in the liquid feeding capacity of the pump 8 can be effectively suppressed, and the output characteristics of the fuel cell 1 can be further improved.

  Note that the internal pressure exceeds the appropriate range when, for example, the fuel cell 1 (the fuel storage unit 6 or the like) is at a high temperature of 100 ° C. or higher, and such a high temperature is rarely used. Since the adjustment of the internal pressure does not necessarily have to be accurate, the pressure adjustment valve 4 of the first embodiment can be sufficiently adjusted without excess or deficiency when the internal pressure exceeds the appropriate range.

  Although the pressure regulating valve of the present invention and the fuel cell using the same have been described above, the present invention is not limited to the above-described embodiment as it is, and the constituent elements are modified within the scope not departing from the gist of the present invention. And can be materialized. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined. Further, the liquid fuel supplied to the fuel cells may be supplied entirely with the vapor of the liquid fuel, but may be supplied in a liquid state.

  For example, the pressure adjusting valve is not necessarily formed directly on the outer wall of the container of the fuel storage portion, and a valve case or the like may be provided on the outer wall of the container to form a valve chamber. In addition, the pressure adjustment valve is not necessarily provided in the fuel storage portion, and may be provided in another part of the fuel distribution mechanism, such as a flow path. In addition, when providing a pressure regulation valve in a flow path, it is preferable to provide in the flow path which becomes a fuel accommodating part side with respect to a pump from a viewpoint of suppressing the fall of the liquid feeding capability of a pump.

1 is a schematic cross-sectional view showing an example of a fuel cell of the present invention. The external view which shows an example of a fuel distribution mechanism. Sectional drawing which shows the pressure regulation valve of a 1st form when the internal pressure of a fuel accommodating part is in an appropriate range. 1 is an external view showing an example of an elastic member (a cylindrical member side and the opposite side). Sectional drawing which shows the pressure regulation valve of a 1st form when the internal pressure of a fuel accommodating part falls below the appropriate range. Sectional drawing which shows the pressure regulation valve of a 1st form when the internal pressure of a fuel accommodating part exceeds the appropriate range. Sectional drawing which shows the pressure control valve of a 2nd form when the internal pressure of a fuel accommodating part is in an appropriate range. Sectional drawing which shows the pressure control valve of a 2nd form when the internal pressure of a fuel accommodating part falls below the appropriate range. Sectional drawing which shows the pressure regulation valve of a 2nd form when the internal pressure of a fuel accommodating part exceeds the appropriate range.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 2 ... Fuel cell, 3 ... Fuel supply mechanism, 4 ... Pressure adjustment valve, 5 ... Fuel distribution mechanism, 6 ... Fuel accommodating part, 7 ... Flow path, 8 ... Pump, 11 ... Anode catalyst layer, DESCRIPTION OF SYMBOLS 12 ... Anode gas diffusion layer, 13 ... Anode (fuel electrode), 14 ... Cathode catalyst layer, 15 ... Cathode gas diffusion layer, 16 ... Cathode (air electrode / oxidant electrode), 17 ... Proton (hydrogen ion) conductivity Electrolyte membrane, 41 ... valve chamber, 42 ... valve body, 43 ... elastic body for pressing, 44 ... fixing member, 44a ... insertion portion, 44b ... large diameter portion, 44c ... cylindrical hole, 46 ... cylindrical member, 46a ... diameter Large part, 46b ... Small diameter part, 46c ... Shaft hole, 47 ... Elastic member, 47a ... Frame part, 47b ... Fitting part, 47c ... Hole part, 47d ... Connection part, 47e ... Groove part, 47f ... Seal part, 61 ... Hole part, 61a ... Inner hole part, 61b ... Outer hole part

Claims (7)

A pressure adjustment valve for a fuel cell, which has a valve chamber and a valve main body accommodated in the valve chamber, and is used for adjusting an internal pressure by being attached to a fuel supply mechanism of the fuel cell;
The valve body includes a tubular member, a frame portion disposed at one end of the tubular member, disposed on a surface of the end portion, a fitting portion fitted into the tubular member, and the frame. A pressure regulating valve for a fuel cell, comprising: an elastic member having a holding portion in which the fitting portion is movably held in a portion and a hole is formed. The pressure regulating valve for a fuel cell according to claim 1,
A pressure adjusting valve for a fuel cell, comprising a pressing elastic body that presses the valve main body toward the elastic member. In the pressure regulation valve for fuel cells according to claim 1 or 2,
The valve chamber is composed of a hole formed in the fuel storage part of the fuel supply mechanism and a cylindrical fixing member fixed so as to be fitted into the hole of the fuel storage part. A fuel cell pressure regulating valve. In the pressure regulation valve for fuel cells according to claim 3,
The hole portion of the fuel storage portion is composed of a small diameter portion formed on the inner side of the fuel storage portion and a large diameter portion formed on the outer side of the small diameter portion. Pressure regulating valve for fuel cell. The pressure regulating valve for a fuel cell according to any one of claims 1 to 4,
The pressure adjustment valve for a fuel cell, wherein the valve body is disposed so that the elastic member side is on the outside of the fuel supply mechanism. The pressure regulating valve for a fuel cell according to any one of claims 1 to 4,
The pressure adjustment valve for a fuel cell, wherein the valve body is disposed so that the elastic member side is an inner side of the fuel supply mechanism. A membrane electrode assembly having a fuel electrode, an air electrode, and an electrolyte membrane sandwiched between the fuel electrode and the air electrode; and a fuel storage unit for storing liquid fuel; A fuel cell having a fuel supply mechanism for supplying fuel to a fuel electrode, and a pressure adjustment valve for a fuel cell attached to the fuel supply mechanism,
The fuel cell pressure regulating valve according to any one of claims 1 to 6, wherein the fuel cell pressure regulating valve is a fuel cell pressure regulating valve.

Images