JP2010033834A - Gas supply valve and fuel cell system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure slidability of a sliding part of a gas supply valve used in a fuel cell system. <P>SOLUTION: The gas supply valve includes a body having a gas passage carrying gaseous hydrogen, and a valve disposed in the gas passage and opening and closing the gas passage by a valve seat part provided on the gas passage. A shaft part extending along the gas passage is provided in the valve, and a support part slidably supporting the shaft part of the valve is provided in the body. In the gas supplying valve, unreacted gaseous hydrogen discharged from fuel cells is supplied to the sliding part where the support part of the body and the shaft part of the valve mutually slide. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas supply valve for adjusting a supply amount of hydrogen gas supplied to a fuel cell, and a fuel cell system using the gas supply valve.

  Patent Document 1 discloses a conventional fuel cell system. This fuel cell system includes a fuel cell and a gas supply valve that adjusts the supply amount of hydrogen gas supplied to the fuel cell. Further, this fuel cell system is provided with a circulation passage for returning unreacted hydrogen gas discharged from the fuel cell to the fuel cell. In this type of fuel cell system, the supply amount of hydrogen gas is adjusted by a gas supply valve to control the amount of power output from the fuel cell.

Patent Document 2 discloses a conventional gas supply valve. The gas supply valve includes a main body having a gas flow path through which gaseous fuel flows, and a valve body that is disposed in the gas flow path and opens and closes the gas flow path. The valve body is provided with a shaft portion that extends toward the upstream side of the gas flow path. The main body is provided with a support portion that slidably supports the shaft portion of the valve body.
In this type of gas supply valve, the wear of the support portion of the main body and the shaft portion of the valve body is likely to progress at the sliding portion where the support portion of the main body and the shaft portion of the valve body slide with respect to each other. Therefore, in the gas supply valve described in Patent Document 2, liquid fuel is supplied to the sliding portion to ensure lubricity of the sliding portion.

Japanese Patent Application No. 2005-243357 Japanese Patent Application No. 2006-118470

In the gas supply valve of Patent Document 2, the liquid fuel supplied for lubrication is mixed into the gaseous fuel discharged from the gas supply valve. In the case of an internal combustion engine that burns gaseous fuel, even if liquid fuel is mixed in the gaseous fuel, the mixed liquid fuel is also burned together, so there is no problem. However, in the fuel cell system, liquid fuel is not allowed to be mixed into the hydrogen gas supplied to the fuel cell. The liquid fuel mixed in the hydrogen gas becomes a harmful impurity that cannot be processed by the fuel cell, and causes a problem such as malfunction of the fuel cell.
The present invention has been made in view of the above circumstances, and provides a technique for ensuring the slidability in the sliding portion of the gas supply valve without using impurities harmful to the fuel cell.

  The present invention is embodied in a gas supply valve that adjusts the supply amount of hydrogen gas supplied to a fuel cell. The gas supply valve includes a main body having a gas flow path through which hydrogen gas flows, and a valve body that is disposed in the gas flow path and opens and closes the gas flow path with a valve seat provided on the gas flow path. ing. The valve body is provided with a shaft portion that extends along the gas flow path, and the main body is provided with a support portion that slidably supports the shaft portion of the valve body. In this gas supply valve, unreacted hydrogen gas discharged from the fuel cell is supplied to the sliding portions of the support portion of the main body and the shaft portion of the valve body that slide with each other.

The hydrogen gas supplied to the fuel cell is exposed to water or cooling water generated during power generation in the fuel cell. Accordingly, the unreacted hydrogen gas discharged from the fuel cell (hereinafter sometimes simply referred to as unreacted gas) contains a relatively large amount of moisture. By supplying the unreacted gas discharged from the fuel cell to the sliding portions of the support portion of the main body and the shaft portion of the valve body that slide relative to each other, moisture in the unreacted gas functions as a lubricant. Thereby, abrasion of a sliding part can be suppressed significantly.
According to this gas supply valve, the slidability in the sliding portion of the gas supply valve can be ensured without using impurities harmful to the fuel cell.

In the gas supply valve described above, the shaft portion of the valve body described above preferably extends in the gas flow path toward the downstream side. And it is preferable that the support part of the above-mentioned main body is provided in the downstream rather than the valve seat part.
According to this configuration, moisture contained in the unreacted gas is not supplied to the valve body and the valve seat portion, and corrosion of the valve body and the valve seat portion can be prevented.

In the gas supply valve, the main body preferably further includes a second gas flow path to which unreacted hydrogen gas discharged from the fuel cell is supplied. In this case, it is preferable that the second gas flow path joins the gas flow path at a position downstream of the valve seat portion and upstream of the sliding portion.
According to this configuration, the unreacted gas discharged from the fuel cell can be reliably supplied to the sliding portions of the main body support portion and the valve body shaft portion that slide relative to each other.

In the gas supply valve, at least one of the support portion of the main body and the shaft portion of the valve body is preferably formed of a porous material such as a sintered metal.
According to this structure, the water | moisture content supplied to the sliding part is hold | maintained by the void | hole of a porous material. Even when the unreacted gas supplied to the sliding portion is temporarily reduced, the slidability in the sliding portion is stably secured.

  When the support portion of the main body is formed of a porous material such as sintered metal, it is possible to supply unreacted hydrogen gas discharged from the fuel cell to the outer peripheral surface of the support portion. . According to this configuration, the above-described second gas flow path is not necessarily provided.

It is preferable that at least one surface of the support portion of the main body and the shaft portion of the valve body is subjected to a treatment for increasing hydrophilicity, for example, by applying titanium oxide.
Thereby, it becomes easy to hold | maintain a water | moisture content on the surface of the support part of a main body, and / or the axial part of a valve body, and can improve both slidability more.

The shaft portion of the valve body is formed with a plurality of projecting portions projecting toward the support portion of the main body at at least two locations in the axial direction, and the plurality of projecting portions are the support portions of the main body. It is preferable that it is slidably contacted.
According to this structure, it is possible to prevent the shaft portion of the valve body from being inclined and to prevent local wear of the support portion of the main body and the shaft portion of the valve body.

The present invention also provides a new and useful fuel cell system using the gas supply valve described above. The fuel cell system provided by the present invention is a fuel cell, a gas supply valve that adjusts the supply amount of hydrogen gas supplied to the fuel cell, and the unreacted hydrogen gas discharged from the fuel cell is recirculated to the fuel cell. A circulation passage is provided. And the sliding part which mutually slides of the support part of a main body and the axial part of a valve body is arrange | positioned in the circulation path, It is characterized by the above-mentioned.
In this fuel cell system, unreacted gas containing moisture discharged from the fuel cell is supplied to the sliding portion of the gas supply valve. Thereby, slidability in the sliding portion of the gas supply valve is ensured, and wear of the support portion of the main body and the shaft portion of the valve body is suppressed.

The circulation passage is preferably provided with a gas-liquid separator at a position downstream of the gas supply valve.
In the fuel cell system described above, the hydrogen gas supplied to the fuel cell contains a relatively large amount of moisture. Since moisture itself is not a harmful impurity for the fuel cell, it does not cause malfunction of the fuel cell. However, when the water concentration in the hydrogen gas becomes excessive, the concentration of the hydrogen gas supplied to the fuel cell relatively decreases, and the output of the fuel cell may decrease. In such a case, it is preferable to remove moisture from the hydrogen gas supplied to the fuel cell by providing a gas-liquid separator at a position downstream of the gas supply valve.

  According to the present invention, it is possible to ensure slidability in the sliding portion of the gas supply valve without using impurities harmful to the fuel cell. The durability of the gas supply valve used in the fuel cell system can be significantly improved.

The main features of the embodiments described below are listed.
(Characteristic 1) The main body includes an inflow pipe, a stator core, a nonmagnetic bush, a valve housing, a valve seat, and a guide nozzle. Each of the inflow pipe, the stator core, the nonmagnetic bush, the valve housing, the valve seat, and the guide nozzle has a through hole. The inflow pipe, the stator core, the nonmagnetic bush, the valve housing, and the valve seat are connected in series, and a gas flow path is formed by the through hole of the inflow pipe, the stator core, the nonmagnetic bush, the valve housing, and the guide nozzle. Hydrogen gas supplied from a hydrogen gas supply source flows from the open end of the inflow pipe, passes through the gas flow path, and is discharged from the open end of the guide nozzle.
(Characteristic 2) The movable body is accommodated in the gas flow path, and is located between the stator core and the valve seat. When the movable body moves toward the downstream valve seat, the valve body provided on the movable body comes into contact with the valve seat, and the gas flow path is closed. When the movable body moves toward the stator core on the upstream side, the valve body provided on the movable body is separated from the valve seat, and the gas flow path is opened.
(Characteristic 3) The valve shaft of the movable body extends in the through hole of the guide nozzle from the valve body toward the downstream side of the gas flow path. The valve shaft of the movable body is slidably supported by the through hole of the guide nozzle. A gap is formed between the outer peripheral surface of the valve shaft of the movable body and the inner peripheral surface of the through hole of the guide nozzle for allowing hydrogen gas to flow therethrough.

(Feature 4) The guide nozzle is formed with a second gas flow path from the outer peripheral surface of the guide nozzle to the through hole of the guide nozzle. The second gas flow path joins the through hole of the guide nozzle at a position upstream of the sliding portion where the valve shaft slides. Unreacted hydrogen gas discharged from the fuel cell is supplied to the second gas flow path. That is, unreacted hydrogen gas discharged from the fuel cell flows in the through hole of the guide nozzle in addition to hydrogen gas supplied from a hydrogen gas supply source. The unreacted hydrogen gas discharged from the fuel cell contains a relatively large amount of moisture, and the moisture lubricates the wall surface of the through hole of the guide nozzle.
(Characteristic 5) The fuel cell system includes a circulation passage for returning unreacted hydrogen gas discharged from the fuel cell to the fuel cell. The circulation passage includes an upstream part for sending unreacted hydrogen gas discharged from the fuel cell to the gas supply valve, and a downstream part for sending the unreacted hydrogen gas and hydrogen gas discharged from the gas supply valve to the fuel cell. ing. The upstream portion of the circulation passage is connected to a second gas flow path formed in the guide nozzle, and supplies unreacted hydrogen gas discharged from the fuel cell into the through hole of the guide nozzle. The downstream portion of the circulation passage is connected to the open end of the guide nozzle, and supplies hydrogen gas discharged from the open end of the guide nozzle to the fuel cell.
(Characteristic 6) The gas supply valve includes an urging member that urges the valve body toward a position where the gas flow path is closed, and an actuator that moves the valve body toward a position where the gas flow path is opened. I have. The actuator is mainly configured by a stator core and an electromagnetic coil provided in the main body, and an armature provided integrally with the valve body.

(First embodiment)
A gas supply valve 10 of a first embodiment embodying the present invention and a fuel cell system 100 using the same will be described with reference to the drawings. FIG. 1 shows a longitudinal sectional view of a gas supply valve 10 of the first embodiment. 2 shows a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 shows a cross-sectional view taken along the line III-III in FIG. FIG. 4 schematically shows the configuration of the fuel cell system 100. In the fuel cell system 100, the supply amount of hydrogen gas (primary supply gas) supplied from the hydrogen gas supply source (for example, a storage tank) to the fuel cell 82 is adjusted by the gas supply valve 10.

  First, the gas supply valve 10 will be described. As shown in FIG. 1, the gas supply valve 10 includes a main body 12, a movable body 70, a compression spring 22, and an electromagnetic coil 72. A gas flow path 20 through which hydrogen gas flows is formed in the main body 12. The gas flow path 20 extends from an open end (upper end in FIG. 1) 16e of an inflow pipe 16 described later to an open end (lower end in FIG. 1) 38e of the guide nozzle 38. Hydrogen gas is supplied to the open end 16e of the inflow pipe 16, passes through the gas flow path 20, and is discharged from the open end (lower end in FIG. 1) 38e. The movable body 70 is disposed in the gas flow path 20 and is supported so as to be movable along the gas flow path 20.

  The movable body 70 is provided with a valve body 50. When the movable body 70 moves to the downstream side of the gas flow path 20, the valve body 50 comes into contact with a valve seat 34 described later, and the gas flow path 20 is closed. When the movable body 70 moves to the upstream side of the gas flow path 20, the valve body 50 is separated from the valve seat 34 and the gas flow path 20 is opened. The movable body 70 is urged toward the downstream side of the gas flow path 20 by the compression spring 22. The gas supply valve 10 is a so-called electromagnetic control valve. As will be described in detail later, in the gas supply valve 10, when the electromagnetic coil 72 is energized, the movable body 70 moves toward the upstream side of the gas flow path 20, and the gas flow path 20 is opened. That is, hydrogen gas is discharged from the gas supply valve 10.

Next, the configuration of each part of the gas supply valve 10 will be described in detail. The main body 12 of the gas supply valve 10 includes an inflow pipe 16, a stator core 18, a nonmagnetic bush 24, a valve housing 30, a valve seat 34, a guide nozzle 38, and a resin casing 74.
The inflow pipe 16 has a substantially cylindrical shape, and a through hole 16a is formed at the center thereof. The through hole 16 a of the inflow pipe 16 constitutes the most upstream part of the gas flow path 20. That is, the open end (upper end in FIG. 1) 16 e of the inflow pipe 16 is the upstream end of the gas flow path 20. Hydrogen gas is supplied to the open end 16e of the inflow pipe 16 from a hydrogen gas supply source (not shown). A filter body 14 for removing foreign substances in the hydrogen gas is disposed in the through hole 16a of the inflow pipe 16. The inflow pipe 16 is made of a metal material having corrosion resistance, and in detail is made of stainless steel.

  The stator core 18 has a substantially cylindrical shape, and a through hole 18a is formed at the center thereof. A downstream portion (lower portion in FIG. 1) of the inflow pipe 16 is inserted into an upstream portion (upper portion in FIG. 1) of the through hole 18a of the stator core 18. The stator core 18 and the inflow pipe 16 are welded over the entire circumference. Thereby, the through-hole 18a of the stator core 18 and the through-hole 16a of the inflow pipe 16 are airtightly connected. The through hole 18 a of the stator core 18 is connected to the through hole 16 a of the inflow pipe 16 and constitutes a part of the gas flow path 20. The stator core 18 is made of a soft magnetic material, and more specifically is made of electromagnetic stainless steel.

  The nonmagnetic bush 24 has a substantially cylindrical shape, and a through hole 24a is formed at the center thereof. A downstream portion (lower portion in FIG. 1) of the stator core 18 is inserted into an upstream portion (upper portion in FIG. 1) of the through hole 24a of the nonmagnetic bush 24. The nonmagnetic bush 24 and the stator core 18 are welded over the entire circumference. Thereby, the through hole 24a of the nonmagnetic bush 24 and the through hole 18a of the stator core 18 are airtightly connected. The through hole 24 a of the nonmagnetic bush 24 is connected to the through hole 18 a of the stator core 18 and constitutes a part of the gas flow path 20. The nonmagnetic bush 24 is made of a nonmagnetic material. A flange portion 24 b is formed at the downstream end (lower end in FIG. 1) of the nonmagnetic bush 24.

  The valve housing 30 has a substantially ring shape, and a through hole 30a is formed at the center thereof. A flange portion 24 b of the nonmagnetic bush 24 is joined to the upstream end surface (the upper surface in FIG. 1) of the valve housing 30. The valve housing 30 and the nonmagnetic bush 24 are welded over the entire circumference. Thereby, the through hole 30a of the valve housing 30 and the through hole 24a of the nonmagnetic bush 24 are connected in an airtight manner. The through hole 30 a of the valve housing 30 is connected to the through hole 24 a of the nonmagnetic bush 24 and constitutes a part of the gas flow path 20. A valve body 50 provided in the movable body 70 is disposed in the through hole 30 a of the valve housing 30.

The valve seat 34 is provided in a downstream portion (a lower portion in FIG. 1) of the valve housing 30. The valve seat 34 has a substantially disc shape, and a through hole 34a is formed at the center thereof. The valve seat 34 and the valve housing 30 are welded over the entire circumference. Thereby, the through hole 34a of the valve seat 34 and the through hole 30a of the valve housing 30 are airtightly connected. The through hole 34 a of the valve seat 34 is connected to the through hole 30 a of the valve housing 30 and constitutes a part of the gas flow path 20.
On the upstream surface (upper surface in FIG. 1) of the valve seat 34, a seat surface 34s with which the valve body 50 abuts is formed. The sheet surface 34s is a flat surface, and a through hole 34a is opened at the center thereof. When the valve body 50 comes into contact with the seat surface 34s, the space between the through hole 30a of the valve housing 30 and the through hole 34a of the valve seat 34 is blocked, and the gas flow path 20 is closed. When the valve body 50 is separated from the seat surface 34s, the through hole 30a of the valve housing 30 and the through hole 34a of the valve seat 34 are communicated, and the gas flow path 20 is opened.

A nozzle holder 36 for holding the guide nozzle 38 is integrally formed on the downstream surface (the lower surface in FIG. 1) of the valve seat 34. The nozzle holder 36 has a substantially cylindrical shape, and a through hole 36a extending to the valve seat 34 is formed at the center thereof.
The guide nozzle 38 has a substantially cylindrical shape, and a through hole 38a is formed at the center thereof. The guide nozzle 38 is fixed to the through hole 36 a of the nozzle holder 36 and is in contact with the downstream surface of the valve seat 34. The through hole 38 a of the guide nozzle 38 communicates with the through hole 34 a of the valve seat 34 and constitutes the most downstream portion of the gas flow path 20. That is, the hydrogen gas that has flowed through the gas flow path 20 is discharged from the open end 38 e of the guide nozzle 38. Further, a valve shaft 40 of a movable body 70 described later extends in the through hole 38a of the guide nozzle 38. The guide nozzle 38 slidably supports a valve shaft 40 extending from the valve body 50.

As shown in FIGS. 1 and 3, a plurality of unreacted gas introduction grooves 38 b are formed on the upstream end face (upper surface in FIG. 1) of the guide nozzle 38. Each unreacted gas introduction groove 38 b extends in the radial direction from the through hole 38 a of the guide nozzle 38 to the outer peripheral surface 38 c of the guide nozzle 38. The plurality of unreacted gas introduction grooves 38b are formed at equal intervals in the circumferential direction. In this embodiment, four unreacted gas introduction grooves 38b are formed at intervals of 90 degrees. The nozzle holder 36 that holds the outer peripheral surface 38 c of the guide nozzle 38 has a plurality of unreacted gas introduction holes 36 b at positions corresponding to the unreacted gas introduction grooves 38 b of the guide nozzle 38. The unreacted gas introduction hole 36 b of the nozzle holder 36 communicates with the through hole 38 a of the guide nozzle 38 through the unreacted gas introduction groove 38 b of the guide nozzle 38.
As will be described in detail later, the upstream portion 92 of the circulation passage 90 is connected to the unreacted gas introduction hole 36b of the nozzle holder 36, and unreacted hydrogen gas (unreacted gas) discharged from the fuel cell 82 is discharged. Sent. The unreacted gas is supplied to the through hole 38 a of the guide nozzle 38 through the unreacted gas introduction groove 38 b of the guide nozzle 38. Thus, the unreacted gas introduction groove 38b of the guide nozzle 38 and the unreacted gas introduction hole 36b of the nozzle holder 36 supply the unreacted gas discharged from the fuel cell 82 to the through hole 38a of the guide nozzle 38. 2 gas flow paths are formed. The second gas flow paths 36b and 38b merge with the through hole 38a of the guide nozzle 38 at a position upstream of a sliding protrusion 42 of the valve shaft 40 described later.

  The resin casing 74 is provided so as to surround the stator core 18, the nonmagnetic bush 24, and the valve housing 30. The resin casing 74 is formed by insert molding, and an electromagnetic coil 72 is embedded therein. The electromagnetic coil 72 is fixed at a position surrounding a part of the stator core 18. A connector portion 76 is formed in the resin casing 74. The connector portion 76 is provided with a plurality of terminal pins 78. An electromagnetic coil 72 is electrically connected to the plurality of terminal pins 78, and the electromagnetic coil 72 is energized through the plurality of terminal pins 78. The connector part 76 is connected to an external control unit via a wire harness (not shown).

  A compression spring 22 is disposed in the gas flow path 20 of the main body 12. The compression spring 22 is located between the inflow pipe 16 and the valve body 50. The compression spring 22 is in a compressed state and urges the valve body 50 toward the valve seat 34. That is, the compression spring 22 presses the valve body 50 against the seat surface 34 s of the valve seat 34 by the biasing force, and closes the gas flow path 20.

  Next, the configuration of each part of the movable body 70 will be described in detail. As shown in FIG. 1, the movable body 70 is located in the gas flow path 20 of the main body 12 and downstream of the stator core 18. The movable body 70 includes a valve shaft 40, a valve body 50, and an armature 60. The valve shaft 40, the valve body 50, and the armature 60 are located on the same axis. The valve shaft 40, the valve body 50, and the armature 60 are integrally formed of a soft magnetic material (specifically, electromagnetic stainless steel). The valve shaft 40 and the valve body 50 are not necessarily formed of a soft magnetic material, and may be formed of a material having excellent strength and corrosion resistance, for example.

  The armature 60 constitutes an upstream portion of the movable body 70 and faces the downstream end of the stator core 18. The armature 60 has a substantially cylindrical shape, and a through hole 60a extending to the valve body 50 is formed at the center thereof. The through hole 60 a of the armature 60 communicates with the through hole 18 a of the stator core 18 and is a part of the gas flow path 20. The upstream portion of the armature 60 is surrounded by an electromagnetic coil 72. The armature 60 is magnetized together with the stator core 18 by the electromagnetic coil 72. When the armature 60 and the stator core 18 are magnetized, the armature 60 is attracted to the stator core 18. As a result, the movable body 70 moves to the stator core 18 side against the urging force of the compression spring 22.

  The valve body 50 constitutes an intermediate portion of the movable body 70 and faces the seat surface 34 s of the valve seat 34. The valve body 50 is formed with a plurality of grooves 52 arranged in the circumferential direction. The groove 52 of the valve body 50 connects the through hole 60 a of the armature 60 and the through hole 30 a of the valve housing 30 to each other, and is a part of the gas flow path 20. The valve body 50 is provided with a flexible seal member 54 at a position facing the seat surface 34s. The seal member 54 can be formed of a rubber material or a resin material. When the movable body 70 moves toward the valve seat 34, the valve body 50 comes into contact with the seat surface 34 s of the valve seat 34. At this time, the gas flow path 20 is closed. When the movable body 70 moves to the stator core 18 side, the valve body 50 is separated from the seat surface 34 s of the valve seat 34. At this time, the gas flow path 20 is opened.

The valve shaft 40 extends from the valve body 50 toward the downstream side of the gas flow path 20. The valve shaft 40 passes through the through hole 34 a of the valve seat 34 and extends to the vicinity of the open end 38 e of the guide nozzle 38. The diameter of the valve shaft 40 is smaller than the diameter of the through hole 34a of the valve seat 34 and the through hole 38a of the guide nozzle 38, and hydrogen gas is contained in the through hole 34a of the valve seat 34 and the through hole 38a of the guide nozzle 38. A flowing space is secured.
As shown in FIGS. 1 and 2, the valve shaft 40 is formed with a plurality of sliding protrusions 42 at two locations in the axial direction. The plurality of sliding protrusions 42 extend radially from the valve shaft 40 toward the guide nozzle 38. The top portion 42 a of the sliding protrusion 42 is slidably in contact with the wall surface of the through hole 38 a of the guide nozzle 38. Thereby, the valve shaft 40 is supported so as to be movable along the through hole 38 a of the guide nozzle 38. That is, the movable body 70 is supported so as to be movable along the gas flow path 20. A space 43 through which hydrogen gas passes is secured between two adjacent sliding protrusions 42.
All the sliding protrusions 42 are provided on the downstream side of the unreacted gas introduction groove 38b of the guide nozzle 38 constituting the second gas flow path. That is, all of the sliding portions where the sliding protrusion 42 and the guide nozzle 38 slide are located on the downstream side of the position where the unreacted gas is supplied into the through hole 38 a of the guide nozzle 38.

  The configuration of the gas supply valve 10 has been described in detail above. Next, the operation of the gas supply valve 10 will be described. While the electromagnetic coil 72 is not energized, the valve body 50 is maintained at a position where it contacts the valve seat 34 by the compression spring 22. The valve body 50 is pressed against the seat surface 34s of the valve seat 34, and the gas flow path 20 is closed. At this time, the hydrogen gas (primary supply gas) supplied from the hydrogen gas supply source is not discharged from the gas supply valve 10.

  When the electromagnetic coil 72 is energized, the electromagnetic coil 72 generates a magnetic field, and the stator core 18 and the armature 60 are excited. The stator core 18 and the armature 60 attract each other, and the armature 60 moves to the stator core 18 side together with the valve body 50. The valve body 50 is separated from the seat surface 34s of the valve seat 34, and the gas flow path 20 is opened. Thereby, the primary supply gas is discharged from the gas supply valve 10.

  As the gas supply valve 10 is opened and closed, the sliding protrusion 42 of the valve shaft 40 slides against the wall surface of the through hole 38 a of the guide nozzle 38. Therefore, when the opening and closing operation of the gas supply valve 10 is repeated, the wall surfaces of the sliding protrusion 42 of the valve shaft 40 and the through hole 38a of the guide nozzle 38 are worn. However, in the gas supply valve 10 of the present embodiment, unreacted gas discharged from the fuel cell 82 is supplied into the through hole 38 a of the guide nozzle 38. The unreacted gas discharged from the fuel cell 82 contains a relatively large amount of water due to water generated in the fuel cell 82 and cooling water flowing in the fuel cell 82. Therefore, by supplying the unreacted gas discharged from the fuel cell 82 to the sliding portion between the sliding protrusion 42 and the guide nozzle 38, the moisture in the unreacted gas functions as a lubricant. Thereby, abrasion of those sliding parts can be suppressed significantly. Further, the unreacted gas is supplied downstream from the valve body 50 and the seat surface 34s with which the valve body 50 abuts. Therefore, the valve body 50 and the seat surface 34s are not corroded by moisture contained in the unreacted gas.

  In the gas supply valve 10 described above, the valve shaft 40 and the guide nozzle 38 can be formed of a porous material such as a sintered material or a foamed material. When the valve shaft 40 and the guide nozzle 38 are formed of a porous material, moisture supplied to the sliding portion between the valve shaft 40 and the guide nozzle 38 is retained by the pores of the porous material. Even if the unreacted gas supplied to the sliding portion is temporarily reduced, the slidability in the sliding portion is stably secured. When the porous material is employed as described above, it is not necessary to form the entire valve shaft 40 and the guide nozzle 38 with the porous material. At least the sliding portion between the valve shaft 40 and the guide nozzle 38 may be formed of a porous material. That is, it is sufficient to form at least one of the top part 42a of the sliding protrusion 42 of the valve shaft 40 and the wall surface of the through hole 38a of the guide nozzle 38 with a porous material.

  In the gas supply valve 10 described above, it is also effective to perform a surface treatment that increases hydrophilicity on the surfaces of the valve shaft 40 and the guide nozzle 38 that slide on each other. As the surface treatment for improving hydrophilicity, for example, a treatment for depositing titanium oxide is suitable. In this case, titanium oxide may be vapor-deposited on the entire surface of the valve shaft 40 and the guide nozzle 38, or titanium oxide may be vapor-deposited only in a range where they slide relative to each other. The surface treatment for increasing the hydrophilicity is preferably performed on both the valve shaft 40 and the guide nozzle 38, but if only one of the valve shaft 40 and the guide nozzle 38 is performed, the slidability of both can be improved. .

The configuration and function of the gas supply valve 10 have been described in detail above. Next, the fuel cell system 100 using the gas supply valve 10 will be described. As shown in FIG. 4, the fuel cell system 100 is mainly configured using a fuel cell 82 and a gas supply valve 10.
A hydrogen gas supply source (not shown) is connected to the gas supply valve 10 through a primary supply passage 96. The primary supply passage 96 is connected to the open end 16 e of the inflow pipe 16 of the gas supply valve 10, and the primary supply gas supplied from the hydrogen gas supply source is supplied from the open end 16 e of the inflow pipe 16 to the gas supply valve 10. To be introduced. The gas supply valve 10 adjusts the amount of primary supply gas supplied to the fuel cell 82 and adjusts the amount of power output from the fuel cell 82.

The fuel cell system 100 is provided with a circulation passage 90 for returning unreacted gas discharged from the fuel cell 82 to the fuel cell 82. The circulation passage 90 includes an upstream portion 92 that sends unreacted gas discharged from the fuel cell 82 to the gas supply valve 10, and a downstream that sends the unreacted gas and the primary supply gas discharged from the gas supply valve 10 to the fuel cell 82. A portion 94 is provided. A pump 84 that pumps unreacted gas is provided in the upstream portion 92 of the circulation channel 90.
The upstream portion 92 of the circulation passage 90 is connected to the unreacted gas introduction hole 38 b of the nozzle holder 36 in the gas supply valve 10. Thereby, the unreacted gas discharged from the fuel cell 82 is introduced into the through hole 38a of the guide nozzle 38 (see FIG. 1). That is, moisture contained in the unreacted gas is supplied to the through hole 38 a of the guide nozzle 38.
The downstream portion 94 of the circulation passage 90 is connected to the open end 38 e of the through hole 38 a of the guide nozzle 38 in the gas supply valve 10. Thereby, the primary supply gas and the unreacted gas discharged from the through hole 38 a of the guide nozzle 38 are sent to the fuel cell 82.

  In this fuel cell system 100, unreacted gas discharged from the fuel cell 82 is supplied to the through hole 38 a of the guide nozzle 38. That is, the unreacted gas discharged from the fuel cell 82 is supplied to the sliding portion between the sliding protrusion 42 and the guide nozzle 38. As a result, moisture in the unreacted gas functions as a lubricant, and wear of the sliding portion can be significantly suppressed.

  As shown in FIG. 5, in the fuel cell system 100, a gas-liquid separator 86 that removes moisture from hydrogen gas and a drain that drains water removed by the gas-liquid separator 86 are disposed in the downstream portion 94 of the circulation passage 90. A discharge valve 87 may be provided. Thereby, excess water can be removed from the hydrogen gas supplied to the fuel cell 82. Since moisture itself is not a harmful impurity for the fuel cell 82, it does not cause malfunction of the fuel cell 82. However, when the moisture concentration in the hydrogen gas becomes excessive, the concentration of the hydrogen gas supplied to the fuel cell 82 may be relatively lowered, and the output of the fuel cell 82 may be lowered. Therefore, by providing the gas-liquid separator 86 at a position downstream of the gas supply valve 10, the output of the fuel cell 82 can be stabilized.

  As shown in FIG. 6, in the fuel cell system 100, an ejector 88 can be used instead of the pump 84. In this case, it is preferable to provide a branch passage 98 in the primary supply passage 96 and supply the primary supply gas supplied from the hydrogen gas supply source to the ejector 88. Thereby, the ejector 88 can send the unreacted gas discharged from the fuel cell 82 to the gas supply valve 10 using the jet of the primary supply gas. The primary supply gas ejected by the ejector 88 can be sufficiently reduced as compared with the unreacted gas discharged from the fuel cell 82. Accordingly, the primary supply gas ejected by the ejector 88 does not greatly affect the supply amount of the hydrogen gas supplied to the fuel ionization 82.

(Second embodiment)
Next, the gas supply valve 110 of the second embodiment will be described. FIG. 7 is a longitudinal sectional view of the gas supply valve 110 of the second embodiment. FIG. 8 is an enlarged view of the vicinity of the guide nozzle 38 of the gas supply valve 110. In the gas supply valve 110 of the second embodiment, the configuration of the guide nozzle 38 is changed compared to the gas supply valve 10 of the first embodiment. Further, the shape of the nozzle holder 36 that holds the guide nozzle 38 is changed in accordance with the change in the configuration of the guide nozzle 38. About another structure, it is the same as the gas supply valve 10 of 1st Example, attaches | subjects the same code | symbol and abbreviate | omits the description.

The guide nozzle 38 of this embodiment is entirely formed of a sintered metal that is a porous material. Thereby, a large number of fine cavities are formed inside the guide nozzle 38. The cavities in the guide nozzle 38 are connected to each other, and many fine passages are formed in the guide nozzle 38. The guide nozzle 38 of the present embodiment is formed thinner than the guide nozzle 38 of the first embodiment. That is, the outer diameter of the guide nozzle 38 of this embodiment is smaller than that of the guide nozzle 38 of the first embodiment. Accordingly, the inner diameter of the nozzle holder 36 that holds the guide nozzle 38 is also reduced. Here, the guide nozzle 38 is not limited to a sintered metal, and may be formed of another porous material such as a non-metallic sintered material or a metal or non-metallic foam material.
The nozzle holder 36 of the present embodiment has a shorter axial length than the nozzle holder 36 of the first embodiment. Thereby, the outer peripheral surface 38c of the guide nozzle 38 is exposed relatively widely. In particular, in the present embodiment, the length of the guide nozzle 38 is fixed on the upstream side of the sliding protrusion 42 provided on the upstream side of the valve shaft 40.

  On the other hand, unlike the guide nozzle 38 and nozzle holder 36 of the first embodiment, the guide nozzle 38 and nozzle holder 36 of the present embodiment introduce an unreacted gas introduction groove 38b for introducing unreacted gas and unreacted gas introduction. The hole 36b is not formed. As described above, many fine passages are formed in the guide nozzle 38 of this embodiment. This fine passage functions as a passage for introducing unreacted gas. Therefore, it is not always necessary to provide a groove or hole for introducing unreacted gas.

The gas supply valve 110 of the present embodiment can be employed in the fuel cell system 100 in the same manner as the gas supply valve 10 of the first embodiment. However, in the gas supply valve 110 of the present embodiment, the guide nozzle 38 may be disposed in the circulation passage 90 in the fuel cell system 100 as shown in FIG. It is not necessary to connect the upstream portion 92 and the downstream portion 94 of the circulation passage 90 to different positions of the guide nozzle 38, respectively.
The arrangement method of the gas supply valve 110 shown in FIG. 7 can also be applied to the gas supply valve 10 of the first embodiment. That is, even when the gas supply valve 10 of the first embodiment is employed in the fuel cell system 100, the gas supply valve 10 may be attached on the circulation passage 90 and the guide nozzle 38 may be disposed in the circulation passage 90. Even in this case, the unreacted gas is introduced into the through hole 36a of the nozzle holder 36 through the unreacted gas introduction hole 36b of the nozzle holder 36 and the unreacted gas introduction groove 38b of the guide nozzle 38.

  As shown in FIG. 8, in the gas supply valve 110, the outer peripheral surface 38 c of the guide nozzle 38 is exposed to unreacted gas flowing through the upstream portion 92 of the circulation passage 90. Here, the arrows in FIG. 8 schematically show the flow of the unreacted gas. The guide nozzle 38 is formed of sintered metal, and a large number of minute passages are formed therein. Accordingly, as shown in FIG. 9, the unreacted gas and moisture contained therein penetrate into the guide nozzle 38 from the outer peripheral surface 38 c of the guide nozzle 38 and reach the through hole 38 a of the guide nozzle 38. Here, the arrows in FIG. 9 schematically show the flow of unreacted gas and moisture that permeate the inside of the guide nozzle 38. Thereby, the sliding part of the valve shaft 40 and the guide nozzle 38, that is, the top part 42a of the sliding protrusion 42 of the valve shaft 40 and the wall surface of the through hole 38a of the guide nozzle 38 are lubricated by moisture. Further, since the guide nozzle 38 is a porous material, the guide nozzle 38 can hold a sufficient amount of moisture. As a result, the slidability in the sliding portion between the valve shaft 40 and the guide nozzle 38 is ensured stably regardless of the flow rate of the unreacted gas.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The longitudinal cross-sectional view of the gas supply valve of 1st Example. II-II sectional view taken on the line in FIG. III-III sectional view taken on the line in FIG. The figure which shows the structure of a fuel cell system. The figure which shows the structure of the 1st modification of a fuel cell system. The figure which shows the structure of the 2nd modification of a fuel cell system. The longitudinal cross-sectional view of the gas supply valve of 2nd Example. The figure which expands and shows the guide nozzle vicinity of the gas supply valve of 2nd Example. The figure which expands and shows the sliding part of the valve shaft of a gas supply valve of 2nd Example, and a guide nozzle.

Explanation of symbols

10: Gas supply valve 12: Main body 16: Inflow pipe 18: Stator core 20: Gas flow path 22: Compression spring 24: Nonmagnetic bush 30: Valve housing 34: Valve seat 34s: Seat surface 36: Nozzle holder 36b: Unreacted gas Introduction hole (part of second gas flow path)
38: Guide nozzle 38b: Unreacted gas introduction groove (a part of the second gas flow path)
40: Valve shaft 42: Sliding protrusion 50 of the valve shaft 50: Valve body 60: Armature 82: Fuel cell 86: Gas-liquid separator 90: Circulation passage 100: Fuel cell system 110: Gas supply valve of the second embodiment

Claims (9)

A gas supply valve that adjusts the supply amount of hydrogen gas supplied to the fuel cell;
A main body having a gas flow path through which hydrogen gas flows;
A valve body that is disposed in the gas flow path and opens and closes the gas flow path with a valve seat provided on the gas flow path;
The valve body is provided with a shaft portion extending along the gas flow path,
The main body is provided with a support portion that slidably supports the shaft portion of the valve body,
An unreacted hydrogen gas discharged from the fuel cell is supplied to a sliding portion that slides between the support portion of the main body and the shaft portion of the valve body. The shaft portion of the valve body extends toward the downstream side of the gas flow path,
The support portion of the main body is provided on the downstream side of the valve seat portion,
2. The gas supply valve according to claim 1, wherein unreacted hydrogen gas discharged from the fuel cell is supplied downstream of the valve body and the valve seat portion. The main body further includes a second gas flow path to which unreacted hydrogen gas discharged from the fuel cell is supplied,
The second gas flow path is joined to the gas flow path at a position downstream of the valve seat portion and upstream of the sliding portion. The gas supply valve described.   The gas supply valve according to any one of claims 1 to 3, wherein at least one of the support portion of the main body and the shaft portion of the valve body is formed of a porous material.   The support portion of the main body is formed of a porous material, and unreacted hydrogen gas discharged from the fuel cell is supplied to the outer peripheral surface of the support portion. The gas supply valve according to any one of the above.   The gas supply according to any one of claims 1 to 5, wherein a treatment for increasing hydrophilicity is performed on at least one surface of the support portion of the main body and the shaft portion of the valve body. valve. The shaft portion of the valve body is formed with a plurality of projecting portions projecting toward the support portion of the main body in at least two locations in the axial direction thereof,
The gas supply valve according to any one of claims 1 to 6, wherein the plurality of projecting portions are slidably in contact with a support portion of the main body. A fuel cell;
The gas supply valve according to any one of claims 1 to 7, wherein a supply amount of hydrogen gas supplied to the fuel cell is adjusted.
A circulation passage for returning unreacted hydrogen gas discharged from the fuel cell to the fuel cell;
A fuel cell system, wherein sliding portions of the support portion of the main body and the shaft portion of the valve body that slide relative to each other are disposed in the circulation passage.   9. The fuel cell system according to claim 8, wherein a gas-liquid separator is provided in the circulation passage on the downstream side of the gas supply valve.

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