JP2010244362A - Pressure reducing valve - Google Patents

Abstract

A pressure reducing valve that has a relief function and can be reduced in size with a simple structure.
A pressure reducing valve includes a communication means for communicating a secondary chamber with the outside by an operation of a diaphragm when a fluid pressure in the secondary chamber exceeds a predetermined value F4. With this configuration, the pressure reducing valve 26 has a relief function and can be reduced in size with a simple structure.
[Selection] Figure 2

Description

  The present invention relates to a pressure reducing valve, and more particularly to an improvement in the structure of a pressure reducing valve having a relief function.

  The pressure reducing valve is a device that keeps the fluid pressure on the secondary side lower than the fluid pressure on the primary side and keeps it constant. Such a pressure reducing valve is known to have a relief function to prevent an abnormal increase in fluid pressure on the secondary side.

  Patent Document 1 below discloses a pressure regulator that is integrally provided with a relief valve portion in a main body of a pressure regulator (corresponding to a pressure reducing valve). The pressure regulator body has a partition that partitions the primary side and the secondary side of the fluid flow path, and an opening that communicates the primary side and the secondary side is formed in the partition. The pressure regulator body includes a pressure regulating unit that regulates the opening of the opening according to the magnitude of the fluid pressure on the secondary side and regulates the fluid pressure on the secondary side. The relief valve part is provided so as to face the pressure regulating part with the fluid flow path in between. The relief valve unit performs a relief operation for discharging the secondary side fluid to the outside when an abnormal increase in the secondary side fluid pressure is detected.

  The following Patent Document 2 discloses a sensor that detects the pressure of air flowing through an air-driven valve, a sensor that detects a stroke of the valve, a sensor that detects the operation of a drive source that drives the valve, and an operation that is transmitted to the valve. A sensor for detecting force and a sensor for detecting the operation of a limit switch for monitoring the open / closed state of the valve, and an air driven valve for diagnosing an abnormality of the air driven valve based on the detection results of these sensors. A diagnostic device is disclosed.

JP 2005-310040 A JP-A-11-210921

  The pressure reducing valve as described in Patent Document 1 is configured so that a pressure regulating portion that is a mechanism for reducing the fluid pressure and a relief valve portion that is a mechanism having a relief function are opposed to each other with a fluid flow path therebetween. Is provided. With such a configuration, it is possible to save space in the direction of the flow path, rather than installing the pressure reducing valve and the safety valve in series with the fluid flow path. However, a place where the installation space for the devices is limited, for example, a pressure reducing valve installed in a vehicle, is required to be further downsized. In addition, when the pressure reducing valve is maintained or inspected or repaired, it is required to further reduce the number of parts and assembly man-hours in order to simplify the work.

  An object of the present invention is to provide a pressure reducing valve having a relief function, which can be reduced in size with a simple structure.

  The present invention communicates with a primary chamber into which a fluid flows from a primary side pipe line, a secondary chamber that communicates with the primary chamber through a communication hole and outflows into a secondary side pipe line, and the outside. A housing having an atmospheric chamber; a diaphragm provided in the housing and defining the secondary chamber and the atmospheric chamber; and a pressure difference between the fluid pressure of the secondary chamber and the atmospheric pressure of the atmospheric chamber connected to the diaphragm When the fluid pressure in the secondary chamber exceeds a predetermined value, the secondary chamber communicates with the outside by the operation of the diaphragm when the fluid pressure in the secondary chamber exceeds a predetermined value. It has a communication means.

  In addition, the communication means is formed in the housing, and is provided in contact with the external communication path that communicates the atmospheric chamber and the outside, and the surface on the atmospheric chamber side of the diaphragm, and is a seal that fits and seals the external communication path When the fluid pressure in the secondary chamber exceeds a predetermined value, a gap is formed between the external communication path and the secondary chamber by being deformed so that the sealing member is crushed by being pushed by the diaphragm. In this way, the secondary chamber can communicate with the outside.

  The housing has a housing main body and a cover that covers the opening of the housing main body, and the diaphragm has a seal portion that is inserted into a joint portion where the housing main body and the cover are joined to improve airtightness in the housing. The sealing member is preferably provided in contact with the surface of the seal portion on the atmosphere chamber side.

  Further, the external communication path can be formed at a joint portion of the housing.

  The housing has a housing main body, a cover that covers the opening of the housing main body, and a fastening bolt in which the shaft portion slidably penetrates the cover and the tip of the shaft portion is screwed into the housing main body. The housing body and the cover are inserted into the joining portion, and have a seal portion that improves the airtightness in the housing, and covers the opening of the housing body so that the housing body side has the secondary chamber and the cover side. The communication chamber is an elastic member that is provided between the neck of the fastening bolt and the cover and biases the cover toward the housing body, and the fluid pressure in the secondary chamber has a predetermined value. If it exceeds, the elastic member pushed by the diaphragm through the cover shrinks to form a gap between the seal part and the joint part, and the secondary chamber communicates with the outside. It is possible.

  In addition, the diaphragm spring is provided in the atmosphere chamber and biases the diaphragm in the direction of opening the communication hole with respect to the valve body; And a position detection sensor for detecting the position of the diaphragm holding portion.

  According to the pressure reducing valve of the present invention, it is possible to cope with downsizing with a simple structure while having a relief function.

It is a figure which shows schematic structure of the fuel cell system mounted in the fuel cell vehicle in this embodiment. It is sectional drawing which shows the structure of the pressure-reduction valve of this embodiment. It is a figure which shows the principal part of a pressure-reduction valve when discharge | releasing the fluid of a secondary side outside. It is a figure which shows the principal part of a pressure-reduction valve when detecting the abnormality of the fluid pressure of the secondary side. It is sectional drawing which shows the structure of the pressure-reduction valve of another aspect. It is a figure which shows the principal part of a pressure-reduction valve when discharge | releasing the fluid of a secondary side outside.

  Hereinafter, an embodiment of a pressure reducing valve according to the present invention will be described with reference to the drawings. As an example, a fuel cell system mounted on a fuel cell vehicle will be described, and a pressure reducing valve installed in a fuel gas conduit through which the fuel gas flows will be described. The present invention can be applied not only to the fuel gas pipe of the fuel cell system but also to a pressure reducing valve installed in a pipe through which a fluid flows.

  First, a fuel cell system 10 mounted on a fuel cell vehicle will be described with reference to FIG. The fuel cell system 10 includes a fuel cell 12 that generates electricity by causing an electrochemical reaction between a fuel gas and an oxidizing gas. The fuel gas used in the fuel cell system 10 is hydrogen, and the oxidizing gas is air.

  The fuel cell 12 includes a fuel gas line 14 that supplies fuel gas to an anode (not shown) of the fuel cell 12, and an oxidant gas line 16 that supplies oxidant gas to the cathode (not shown) of the fuel cell 12. Is connected.

  Further, in the fuel cell 12, the exhaust fuel gas exhausted from the anode is returned to the fuel gas conduit 14, and the exhaust fuel gas exhausted from the cathode is connected to the circulation conduit 18 for circulating the exhaust fuel gas to the fuel cell 12. Is connected to the discharge pipe 20.

  The fuel cell 12 is a solid polymer fuel cell having an electrolyte membrane which is a proton conductive membrane formed of a polymer material such as a fluororesin. A unit cell (not shown) of the battery is configured by further sandwiching a membrane electrode assembly (MEA) formed by sandwiching an electrolyte membrane between an anode and a cathode between two separators. The fuel cell 12 is configured by stacking a plurality of the unit cells.

  The fuel cell system 10 includes a tank 22 as a supply source for supplying fuel gas to the fuel cell 12. The tank 22 stores the fuel gas in a high pressure state. The tank 22 and the fuel cell 12 are connected by a fuel gas pipe 14.

  A main stop valve 24 and a pressure reducing valve 26 are sequentially attached to the fuel gas pipe 14 from the tank 22 toward the fuel cell 12.

  The main stop valve 24 is an electromagnetic valve that opens and closes the valve by driving an electromagnet with an electric signal. The main stop valve 24 is closed when the automobile is stopped, specifically when the ignition switch is off, and is opened when the automobile is operating, specifically when the ignition switch is on. Be controlled. Further, as will be described in detail later, the main stop valve 24 opens and closes the valve by an electrical signal from a position detection sensor 28 (shown in FIG. 3) built in the pressure reducing valve 26.

  When the pressure of the fuel gas supplied to the fuel cell 12 rises abnormally together with the function of the pressure reducing valve for reducing the pressure of the fuel gas supplied from the tank 22 to the fuel cell 12, the pressure reducing valve 26 of the present embodiment This is a valve device having a function of a safety valve for releasing fuel gas to the outside. The detailed structure of the pressure reducing valve 26 will be described later.

  Further, a circulation pipe 18 is connected to the fuel gas pipe 14 on the downstream side of the pressure reducing valve 26. In the circulation line 18, a gas-liquid separation device 30 and a pump 32 are sequentially provided between the fuel cell 12 and the portion connected to the fuel gas line 14. The exhaust fuel gas discharged from the fuel cell 12 includes unreacted fuel gas and water (including water vapor) generated by an electrochemical reaction. The gas-liquid separator 30 separates water contained in the exhaust fuel gas. A drain valve 34 for draining the separated water is connected to the gas-liquid separator 30, and the discharge pipe 20 described above is connected to the drain valve 34. The pump 20 sends the exhaust fuel gas discharged from the fuel cell 12 to the fuel gas conduit 14.

  An end portion of the oxidizing gas pipe 16 connected to the cathode of the fuel cell 12 is opened to the outside. A filter 36 and an air pump 38 are provided in this order from the end of the oxidizing gas pipe 16 toward the fuel cell 12. By the operation of the air pump 38, external air is purified by the filter 36 and supplied to the fuel cell 12. Supplied.

  Next, the configuration of the pressure reducing valve 26 will be described with reference to FIG. The pressure reducing valve 26 has a housing 40. The housing 40 includes a housing main body 42 and a cover 44 that can be attached to and detached from the housing main body 42.

  The housing main body 42 has an opening 46 formed on the upper surface of the housing main body 42 in consideration of assembly of the pressure reducing valve 26 or workability for maintenance and inspection. Around the opening 46, there is an end face of the housing main body 42 so as to border the opening 46. As will be described later, this surface is a surface that is bonded to the cover 44, and this is hereinafter referred to as a housing body bonding surface 42a.

  The housing body 42 includes a primary port 48 connected to the fuel gas conduit 14 (primary conduit) communicating with the tank 22 and a fuel gas conduit 14 (secondary conduit) communicating with the fuel cell 12. A secondary port 50 connected to the road) is attached. The housing main body 42 includes a primary chamber 52 into which fuel gas flows from the primary side port 48 and a secondary chamber 54 into which fuel gas flows out to the secondary side port 50. The housing body 42 is formed with a communication hole 56 that allows the primary chamber 52 and the secondary chamber 54 to communicate with each other, and a valve seat 58 on the opening side of the communication hole 56.

  A valve body 60 is provided in the primary chamber 52 and the secondary chamber 54 so as to penetrate the communication hole 56. The valve body 60 has a shape corresponding to the valve seat 58, and operates in a state in which the valve seat 58 comes into contact with the valve seat 58 and closes, and in a state in which the valve seat 58 leaves the valve seat 58 and opens. A valve spring 62 is installed on the wall surface of the primary chamber 52 facing the communication hole 56. One end of the valve spring 62 is in contact with the wall surface of the primary chamber 52, and the other end is in contact with the valve body 60. The valve spring 62 closes the valve seat 58 by the valve spring 62, that is, from the primary chamber 52. A biasing force is applied to bias the secondary chamber 54 in the direction toward the secondary chamber 54 (direction of arrow X1 in FIG. 2) through the communication hole 56.

  The cover 44 is a lid that covers the opening 46 of the housing body 42. The cover 44 has a shape in which a portion corresponding to the opening 46 is raised. A cover joint surface 44a is formed on the outer periphery of the cover 44 so as to face the housing body joint surface 42a and to be joined thereto. The cover joint surface 44a and the housing main body joint surface 42a are joined, and the cover 44 and the housing main body 42 are fastened by the fastening bolts 64, whereby the cover 44 is fixed to the housing main body 42 and covers the opening 46. Here, a portion where the cover joint surface 44a and the housing body joint surface 42a are joined, that is, a portion where the cover 44 and the housing body 42 are joined is referred to as a joint portion 66 hereinafter.

  The housing 40 includes a diaphragm 68 formed in a film shape using an elastic material such as rubber or soft resin or a metal as a base material. The diaphragm 68 covers the opening 46 and is attached by being sandwiched between the housing main body 42 and the cover 44. As described above, since the portion of the cover 44 corresponding to the opening 46 is raised, the portion covering the opening 46 is formed by the diaphragm 68 and the cover 44 arranged at a predetermined interval with respect to this. Composed. With this configuration, a space is formed between the cover 44 and the diaphragm 68. This space communicates with the outside through a through-hole 70 formed in the cover 44 and is always in an atmospheric pressure state. Therefore, this space is hereinafter referred to as an atmospheric chamber 72. In this way, the diaphragm 68 covers the opening 46 to partition the secondary chamber 54 on the housing body 42 side and the atmospheric chamber 72 on the cover 44 side.

  The diaphragm 68 has a seal portion 74 on the outer peripheral portion thereof, and the seal portion 74 is inserted into the joint portion 66. Since the seal portion 74 is tightly adhered to the cover joint surface 44a and the housing body joint surface 42a by tightening the fastening bolt 64, the airtightness of the housing 40 is improved.

  A diaphragm holding portion 76 for holding the diaphragm 68 is provided in the central area of the diaphragm 68. The diaphragm holding unit 76 includes a first holding unit 78 located on the atmosphere chamber 72 side and a second holding unit 80 located on the secondary chamber 54 side, and these holding units 78 and 80 sandwich the diaphragm 68. To do. The diaphragm 68 of the present embodiment has a hole formed in the central region thereof, and has a seal portion 81 at the edge of the hole. The seal portion 81 is inserted between the first and second holding portions 78 and 80, and the first and second holding portions are tightened by tightening the first and second holding portions 78 and 80 with bolts (not shown). Close contact with 78, 80 without gap. The size of the hole formed in the central region of the diaphragm 68 is larger than the diameter of the shaft portion of the bolt that fastens the first and second holding portions 78, 80, and the first and second holding portions 78, 80. If it is smaller, it can be of any size.

  A valve body 60 is connected to the second holding unit 80. A diaphragm spring 82 is provided in the atmospheric chamber 72. One end of the diaphragm spring 82 is in contact with the wall surface of the cover 44 facing the communication hole 56, and the other end is in contact with the first holding portion 78, and the diaphragm spring 82 passes through the diaphragm 68 and the diaphragm holding portion 76. The valve body 60 is applied with a biasing force that biases the valve seat 58 in the direction in which the valve seat 58 is opened, that is, the direction from the secondary chamber 54 to the primary chamber 52 through the communication hole 56 (the direction of the arrow X2 in FIG. 2). That is, the diaphragm spring 82 exerts a biasing force in the opposite direction with respect to the valve spring 62. The spring load of the diaphragm spring 82 is set larger than the spring load of the valve spring 62. For this reason, in a state where no fluid is introduced into the pressure reducing valve 26, the valve body 60 moves in the X2 direction, and the communication hole 56 is in an open state.

  An operation in which the pressure reducing valve 26 reduces the fluid pressure will be described. The fuel gas that has flowed into the primary chamber 52 from the fuel gas conduit 14 via the primary port 48 passes through the communication hole 56 and is decompressed and flows into the secondary chamber 54. Thus, the diaphragm 68 receives a force F1 in the X1 direction based on the pressure difference between the pressure of the fuel gas in the secondary chamber 54 and the pressure in the atmospheric chamber 72. At this time, the diaphragm 68 receives a force F2 from the valve spring 52 through the valve body 60 in the X1 direction and a force F3 from the diaphragm spring 82 in the X2 direction. The diaphragm 68 is elastically deformed in the X1 or X2 direction by these forces, and the valve body 60 is held when the sum of the forces F1 and F2 in the X1 direction and the force F3 in the X2 direction are balanced. By this balance, the opening degree of the communication hole 56 is determined. On the other hand, when the force toward the X1 direction and the force toward the X2 change, the diaphragm 68 is elastically deformed and the position at which the valve body 60 is balanced changes, so that the opening degree of the communication hole 56 changes. For example, as the pressure of the fuel gas in the secondary chamber 54 increases, the force F1 in the X1 direction increases, so that the diaphragm 68 operates in the X1 direction, and the valve body 60 closes the communication hole 56 (X1 direction). Moving. On the other hand, as the pressure of the fuel gas in the secondary chamber 54 decreases, the force F1 directed in the X1 direction decreases, so that the diaphragm 68 operates in the X2 direction, and the valve body 60 moves in the direction in which the communication hole 56 is opened (X2 direction). Moving. By such an operation of the diaphragm 68, the pressure reducing valve 26 can reduce the fluid pressure and keep the secondary side fluid pressure constant.

  The pressure reducing valve 26 according to the present embodiment includes communication means 84 that causes the secondary chamber 54 to communicate with the outside by the operation of the diaphragm 68 when the fluid pressure in the secondary chamber 54 exceeds a predetermined value F4. With this configuration, the pressure reducing valve 26 has a relief function and can be reduced in size with a simple structure. Hereinafter, the communication means 84 will be described in detail. Here, the predetermined value F4 is a value that may damage the secondary system due to the pressure of the fuel gas on the secondary side.

  The communication means 84 is formed in the housing 40 and is provided in contact with the external communication path 86 that communicates the atmosphere chamber 72 with the outside, and the surface of the diaphragm 68 on the atmosphere chamber 72 side. And a sealing member 88 for sealing.

  The external communication path 86 is formed in the joint portion 66 of the housing 40. Specifically, a groove is formed on the cover joint surface 44a of the cover 44 from the outside toward the atmosphere chamber 72, and the housing body joint surface 42a covers the opening of the groove to form the external communication path 86. .

  The sealing member 88 is provided between the deformation member 90 that deforms so as to be crushed when a force exceeding a predetermined force F4 is applied, and between the deformation member 90 and the diaphragm 68, and the uniform between the diaphragm 68 and the deformation member 90. A plate-like member 92 that secures the surface pressure and seals the external communication path 86. The deformation member 90 is a member having plasticity, for example, a pipe made of metal. The plate-like member 92 is provided in contact with the surface on the atmosphere chamber 72 side of the seal portion 74 of the diaphragm 68. The deformable member 90 may be, for example, a leaf spring that has an elasticity that deforms when a force exceeding a predetermined force F4 is applied and returns to the original shape when the force falls below the force F4. Further, the sealing member 88 is not required to have the plate-like member 92 as long as a uniform surface pressure is secured between the diaphragm 68 and the deforming member 90 and the deforming member 90 seals the external communication path 86. Good.

  Next, the operation in which the pressure reducing valve 26 releases the fuel gas to the outside when the pressure of the fuel gas in the secondary chamber 54 exceeds the predetermined value F4 will be described with reference to FIG. FIG. 3 is a view showing a main part of the pressure reducing valve 26 when the secondary fluid is discharged to the outside.

  When the pressure of the fuel gas in the secondary chamber 54 exceeds a predetermined value F4, the force is applied to the diaphragm 68 in the X1 direction, and at the same time, the force is also applied to the sealing member 88 via the diaphragm 68. As described above, the sealing member 88 includes the deformation member 90 that deforms so as to be crushed when a force exceeding the predetermined force F4 is applied. For this reason, the sealing member 88 is pushed by the diaphragm 68 in the X1 direction and is crushed in the X1 direction. At this time, since the seal portion 74 of the diaphragm 68 moves in the X1 direction, a gap is generated between the seal portion 74 and the housing body joining surface 42a. By this gap, the secondary chamber 54 and the external communication path 86 communicate with each other, and the fuel gas in the secondary chamber 54 is discharged to the outside.

  According to the pressure reducing valve 26 of the present embodiment, by adding a simple structure of the communication means 84 to the structure of the conventional pressure reducing valve having only the pressure reducing function, an abnormal increase in the pressure of the fuel gas on the secondary side can be ensured. Can be prevented. Moreover, since the communication means 84 is attached inside the housing of the conventional pressure-reduction valve which has only a pressure reduction function, it can respond to size reduction. Further, since the communication means 84 has a small number of parts, when the pressure reducing valve 26 is inspected or repaired, the number of assembling steps can be reduced, and the work can be simplified.

  Further, the pressure reducing valve 26 of the present embodiment has a position detection sensor 28 that detects the position of the diaphragm holding portion 78. The configuration of the position detection sensor 28 will be described with reference to FIG.

  The position detection sensor 28 is provided on the inner wall of the cover 44. The position detection sensor 28 has a rod-shaped contact 28a that extends from the sensor main body toward the atmosphere chamber 54 and is rotatable in the X1 or X2 direction. The contact 28a has a length that the tip of the contact 28a extends over the movable range of the diaphragm holding portion 76, and when the pressure of the fuel gas in the secondary chamber 54 is a predetermined value F5 lower than the predetermined value F4, the diaphragm holding portion 76. Is set to touch. Here, the predetermined value F5 is the pressure value of the fuel gas that can be allowed by the secondary system, that is, the upper limit value of the secondary fluid pressure.

  The operation of the position detection sensor 28 will be described. As the pressure of the fuel gas in the secondary chamber 54 increases to the predetermined value F5, the diaphragm 68 and the diaphragm holding portion 76 move in the X1 direction. When the pressure of the fuel gas in the secondary chamber 54 reaches the predetermined value F5, the first holding portion 78 of the diaphragm holding portion 76 and the contact 28a come into contact with each other, and the contact 28a rotates in the X1 direction. By the operation of the contact 28a, the electric circuit in the position detection sensor 28 is closed, and the position detection sensor 28 detects the position of the diaphragm holding portion 76 when the fuel gas pressure in the secondary chamber 54 is a predetermined value F5. can do. That is, the position detection sensor 28 can detect a preset secondary fuel gas pressure value.

  According to such a configuration, the position detection sensor 28 can detect the allowable upper limit value F5, which is the pressure value of the fuel gas on the secondary side, so that the second upper limit value F5 is detected in order to detect the same upper limit value F5. The pressure sensor installed in the fuel gas pipe 14 on the next side can be omitted. When the pressure of the secondary side fuel gas reaches the upper limit value F5, the main stop valve 24 of the fuel cell system 10 is closed based on the detection signal of the position detection sensor 28, whereby the primary side fuel gas conduit Thus, the fuel gas flowing into the pressure reducing valve 26 from 14 can be stopped, and the malfunction of the fuel cell system 10 can be prevented in advance.

  In the present embodiment, the case where the contact point 28a of the position detection sensor 28 is in contact with the diaphragm holding unit 76 to detect the position of the diaphragm holding unit 76 has been described, but the present invention is not limited to this configuration. It is also possible to detect the position of the diaphragm holding unit 76 by using a non-contact position sensor with a built-in coil and detecting a change in magnetic flux.

  Next, the configuration of the pressure reducing valve 26 according to another aspect will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the same component as the said embodiment, and detailed description is abbreviate | omitted.

  The housing main body 42 is formed with a hole 42b for a fastening bolt 64 that engages with a screw thread formed in the shaft portion 64a. And the hole 44b for the fastening bolt 64 is formed in the cover 44 so that a space | interval may be provided with respect to the shaft part 64a when the shaft part 64a penetrates. The holes 42b and 44b are formed so that the total length of these holes 42b and 44b is shorter than the length of the shaft portion 64a of the fastening bolt 64. By inserting the shaft portion 64a of the fastening bolt 64 in the X2 direction into the holes 42b and 44b configured as described above, the fastening bolt 64 penetrates the shaft portion 64a slidably into the cover 44, and the shaft portion 64a. The front end of the housing is screwed into the housing body 42. At this time, the neck portion 64 b of the fastening bolt 64 is positioned with a space from the surface of the cover 44.

  The communication means 94 in this embodiment is an elastic member that is provided between the neck portion 64b of the fastening bolt 64 and the cover 44 and biases the cover 44 in the direction of the housing body 42 (X2 direction). The elastic member is, for example, a coil spring wound around the outer periphery of the shaft portion 64 b with a space therebetween, and is provided so that one end of the coil spring contacts the neck portion 64 b and the other end contacts the cover 44. . This coil spring has a characteristic of contracting in the axial direction when a force exceeding the above-described predetermined force F4 is applied. Under normal conditions, the cover 44 is pressed against the housing body 42 by the biasing force of the coil spring, and the cover 44 is fixed to the housing body 42. At this time, the seal portion 74 of the diaphragm 68 inserted into the joint portion 66 is closely attached to the cover joint surface 44a and the housing body joint surface 42a by the urging force of the communication means 94, so that the airtightness of the housing 40 is improved. To do.

  Next, the operation in which the pressure reducing valve 26 releases the fuel gas to the outside when the pressure of the fuel gas in the secondary chamber 54 exceeds the predetermined value F4 will be described with reference to FIG. FIG. 6 is a diagram illustrating a main part of the pressure reducing valve 26 when the secondary fluid is discharged to the outside.

  When the pressure of the fuel gas in the secondary chamber 54 exceeds the predetermined value F4, the force is applied to the diaphragm 68 in the X1 direction, and at the same time, the force is applied from the diaphragm 68 to the communication means 94 through the cover 44. Specifically, as shown in the figure, when the pressure of the fuel gas in the secondary chamber 54 exceeds a predetermined value F4, the diaphragm 68 and the diaphragm holding portion 76 that have received the force move in the X1 direction, and the diaphragm The end portion of the first holding portion 78 of the holding portion 76 contacts the inner wall of the cover 44. The force received by the diaphragm 68 and the diaphragm holding portion 76 is applied to the communication means 94 via the cover 44.

  As described above, the communication means 94 is a coil spring that deforms so as to contract when a force exceeding a predetermined force F4 is applied. For this reason, the communication means 94 is pushed in the X1 direction by the cover 44 pushed by the diaphragm 68 and contracts. At this time, since the seal portion 74 of the diaphragm 68 moves in the X1 direction, a gap is generated between the seal portion 74 and the housing body joint surface 42a, and also between the housing body joint surface 42a and the cover joint surface 44a. A gap is created. By these gaps, the secondary chamber 54 communicates with the outside, and the fuel gas in the secondary chamber 54 is released to the outside.

  According to the pressure reducing valve 26 of this embodiment, the communication means 94 having a simple structure is added to the structure of the conventional pressure reducing valve having only the pressure reducing function, which is less than the communication means 84 of the above-described embodiment, thereby An abnormal increase in the pressure of the secondary fuel gas can be reliably prevented. Moreover, since the communication means 94 is attached between the neck part 64b of the fastening bolt 64 and the cover 44, it can respond to size reduction. Further, since the communication means 94 has a small number of parts, when the pressure reducing valve 26 is inspected or repaired, the number of assembling steps can be reduced, and the work can be simplified.

  DESCRIPTION OF SYMBOLS 10 Fuel cell system, 12 Fuel cell, 14 Fuel gas line, 22 Tank, 24 Main stop valve, 26 Pressure reducing valve, 28 Position detection sensor, 40 Housing, 42 Housing main body, 44 Cover, 52 Primary chamber, 54 Secondary chamber , 56 Communication hole, 60 Valve body, 64 Fastening bolt, 66 Joint part, 68 Diaphragm, 72 Air chamber, 74 Seal part, 76 Diaphragm holding part, 82 Diaphragm spring, 84, 94 Communication means, 86 External communication path, 88 Sealing Stop member.

Claims (6)

A primary chamber into which fluid flows from the primary side pipe line, a secondary chamber that communicates with the primary chamber through a communication hole and fluid flows out to the secondary side pipe line, and an atmospheric chamber that communicates with the outside. A housing having
A diaphragm provided inside the housing and defining a secondary chamber and an atmospheric chamber;
A valve body connected to the diaphragm, which opens and closes the communication hole by the operation of the diaphragm elastically deformed by a pressure difference between the fluid pressure in the secondary chamber and the atmospheric pressure in the atmospheric chamber;
In a pressure reducing valve having
A pressure reducing valve comprising a communication means for communicating the secondary chamber and the outside by operation of a diaphragm when the fluid pressure in the secondary chamber exceeds a predetermined value. The pressure reducing valve according to claim 1,
Communication means
An external communication path formed in the housing and communicating between the atmospheric chamber and the outside;
A sealing member that is provided in contact with the surface of the diaphragm on the atmosphere chamber side, fits in the external communication path, and seals it;
Have
When the fluid pressure in the secondary chamber exceeds a predetermined value, a gap is formed between the external communication path and the secondary chamber by being deformed so that the sealing member is crushed by being pushed by the diaphragm, and the secondary chamber and Communicating with the outside,
A pressure reducing valve characterized by that. The pressure reducing valve according to claim 2,
The housing has a housing body and a cover that covers the opening of the housing body,
The diaphragm is inserted into a joint portion where the housing body and the cover are joined, and has a seal portion that improves airtightness in the housing,
The sealing member is provided in contact with the surface on the atmosphere chamber side of the seal portion.
A pressure reducing valve characterized by that. The pressure reducing valve according to claim 3,
The external communication path is formed at the joint portion of the housing.
A pressure reducing valve characterized by that. The pressure reducing valve according to claim 1,
The housing includes a housing main body, a cover that covers the opening of the housing main body, and a fastening bolt that the shaft portion slidably penetrates the cover and the tip of the shaft portion is screwed into the housing main body.
The diaphragm is inserted into a joint portion where the housing main body and the cover are joined, and has a seal portion that improves airtightness in the housing, and covers the opening of the housing main body, so that the secondary chamber and the cover are provided on the housing main body side. An air chamber is formed on the side,
The communication means is an elastic member that is provided between the neck of the fastening bolt and the cover and urges the cover toward the housing body.
When the fluid pressure in the secondary chamber exceeds a predetermined value, the elastic member pushed by the diaphragm through the cover shrinks, so that a gap is formed between the seal portion and the joint portion. Communicate,
A pressure reducing valve characterized by that. The pressure reducing valve according to any one of claims 1 to 5,
A diaphragm spring that is provided in the atmospheric chamber and biases the diaphragm with a biasing force in a direction to open the communication hole with respect to the valve body;
A diaphragm holding portion that abuts against one end of the diaphragm spring and receives a biasing force of the diaphragm spring, and holds the diaphragm;
A position detection sensor for detecting the position of the diaphragm holding portion;
Having
A pressure reducing valve characterized by that.

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