Overflow prevention valve device and valve assembly

Abstract

An overflow prevention valve (18) is provided with: a valve seat (41) provided in a valve body housing section (53) of a gas flow path and having a valve port (56); a valve body (42) configured so as to be slidably housed in the valve body housing part (53); and a biasing member (43) configured to bias the valve body in a direction in which the valve body is separated from the valve seat. The valve body is provided with: a head part (64) configured so as to block the valve port by seating on the valve seat; and a protruding portion (65) configured to protrude from the head portion and be inserted into the valve port. A movement range of the spool between the open position and the closed position includes a first transition range and a second transition range. The first transition range is a range in which the valve body moves in a state in which the entire protrusion is disposed in the valve body housing portion. The second transition range is a range in which the valve body moves in a state in which at least a portion of the protrusion is disposed within the valve port.

Description

Technical Field

[0001] The present disclosure relates to an overcurrent prevention valve device and a valve assembly. Background Art

[0002] For example, Patent Document 1 discloses a valve assembly for controlling the flow of gas. Such a valve assembly is installed in, for example, a gas tank of a fuel cell vehicle to control the flow of hydrogen.

[0003] The valve assembly of Patent Document 1 includes a main body having a gas flow path and a plurality of valve sub-assemblies installed on the main body. The valve sub-assembly includes an overcurrent prevention valve that restricts the flow of hydrogen so that the flow rate of the gas when hydrogen is sent out does not exceed a predetermined specified amount.

[0004] Such an overcurrent prevention valve includes: a valve seat provided in the middle of the gas flow path; a valve element slidably housed in the gas flow path; and a spring that biases the valve element in a direction to move the valve element away from the valve seat. The valve element slides in the gas flow path according to the force corresponding to the pressure difference between the upstream side pressure and the downstream side pressure of the valve element and the preload of the spring. For example, if the pipe connected to the overcurrent prevention valve is normal and the pressure difference is within the normal range, the preload of the spring is greater than the force corresponding to the pressure difference. Therefore, normally, the valve element moves away from the valve seat, and the overcurrent prevention valve is in an open state. On the other hand, for example, when the pressure difference becomes too large due to pipe damage, the force corresponding to the pressure difference becomes greater than the preload of the spring. As a result, in the abnormal state, the valve element seats on the valve seat, and the overcurrent prevention valve is in a closed state. Thereby, it is possible to prevent the flow rate of hydrogen from exceeding the specified amount.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-523509 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The overcurrent prevention valve as described in Patent Document 1 preferably stably maintains an open state normally, and can quickly switch from the open state to the closed state, for example, when an abnormality in the pipe occurs.

[0010] Means for Solving the Problems

[0011] An overcurrent prevention valve device according to one aspect of the present disclosure includes: a flow path forming member having a gas flow path; and an overcurrent prevention valve configured to restrict the flow of gas when the flow rate of the gas flowing through the gas flow path in a predetermined direction exceeds a predetermined amount. The gas flow path has a spool housing portion that houses at least a part of the overcurrent prevention valve. The overcurrent prevention valve includes: a valve seat provided in the spool housing portion and having a valve port; a spool configured to be slidably housed in the spool housing portion; and a biasing member configured to bias the spool in a direction to move the spool away from the valve seat. The spool has: a head configured to block the valve port by seating on the valve seat; and a protrusion configured to protrude from the head and be inserted into the valve port. The position of the spool farthest from the valve seat is an open position, and the position where the spool seats on the valve seat is a closed position. The movement range of the spool between the open position and the closed position includes a first transition range and a second transition range. The first transition range is the range in which the spool moves in a state where the entire protrusion is disposed in the spool housing portion, and the second transition range is the range in which the spool moves in a state where at least a part of the protrusion is disposed in the valve port.

[0012] A valve assembly according to another aspect of the present disclosure includes: a body having a gas flow path including a first flow path and a second flow path; and an overcurrent prevention valve configured to restrict the flow of gas when the flow rate of the gas flowing through the second flow path in a predetermined direction exceeds a predetermined amount. The first flow path is configured to be connected to a gas cylinder that stores gas, and the second flow path is configured to be selectively connected to any one of a plurality of external devices. The plurality of external devices include a supply source of gas to be filled into the gas cylinder and a consumption device that consumes the gas sent out from the gas cylinder. The second flow path has a spool housing portion that houses at least a part of the overcurrent prevention valve. The predetermined direction is the direction in which gas is sent to the consumption device. The overcurrent prevention valve includes: a valve seat provided in the spool housing portion and having a valve port; a spool configured to be slidably housed in the spool housing portion; and a biasing member configured to bias the spool in a direction to move the spool away from the valve seat. The spool has: a head configured to block the valve port by seating on the valve seat; and a protrusion configured to protrude from the head and be inserted into the valve port. The position of the spool farthest from the valve seat is an open position, and the position where the spool seats on the valve seat is a closed position. The movement range of the spool between the open position and the closed position includes a first transition range and a second transition range. The first transition range is the range in which the spool moves in a state where the entire protrusion is disposed in the spool housing portion, and the second transition range is the range in which the spool moves in a state where at least a part of the protrusion is disposed in the valve port. Description of the Drawings

[0013] Figure 1 is a cross-sectional view showing a schematic structure of a valve assembly according to an embodiment.

[0014] Figure 2 is Figure 1 a magnified cross-sectional view near the backflow prevention valve in the valve assembly of , and is a magnified cross-sectional view of the state where the valve core of the backflow prevention valve is in the open position.

[0015] Figure 3 is a perspective view of the valve core of the backflow prevention valve Figure 2 viewed from the first side.

[0016] Figure 4 is a perspective view of the valve core of the backflow prevention valve Figure 2 viewed from the second side.

[0017] Figure 5 is Figure 2 a magnified cross-sectional view near the backflow prevention valve of the state where the valve core of the backflow prevention valve is in the first transition range.

[0018] Figure 6 is Figure 2 a magnified cross-sectional view near the backflow prevention valve of the state where the valve core of the backflow prevention valve is in the second transition range.

[0019] Figure 7 is Figure 2 a magnified cross-sectional view near the backflow prevention valve of the state where the valve core of the backflow prevention valve is in the closed position. Detailed Embodiment

[0020] Hereinafter, an embodiment of a backflow prevention valve device and a valve assembly will be described with reference to the drawings.

[0021] In this specification, "annular" only needs to be regarded as annular as a whole, and also includes a structure formed by combining a plurality of components or parts to form an annular shape, and a structure having a notch in a part such as a C shape. The shape of "annular" includes, but is not limited to, a circular shape, an elliptical shape, and a polygon with sharp corners or rounded corners when viewed axially.

[0022] (Overall Structure)

[0023] Figure 1The illustrated valve assembly 1 is installed, for example, on a gas tank 2 of a fuel cell vehicle. High-pressure hydrogen gas of about 72.5 MPa is stored in the gas tank 2. In addition, the valve assembly 1 is selectively connected to any one of a plurality of external devices 3. The plurality of external devices 3 includes a supply source 4 for filling hydrogen gas into the gas tank 2 and a consumption device 5 that consumes the hydrogen gas sent out from the gas tank 2. The supply source 4 is, for example, a hydrogen refueling station and is connected to the valve assembly 1 via a pipe 6. The consumption device 5 is, for example, a fuel cell mounted on a vehicle and is connected to the valve assembly 1 via a pipe 7. The valve assembly 1 controls the flow of the hydrogen gas filled in the gas tank 2 and the hydrogen gas sent out from the gas tank 2.

[0024] The valve assembly 1 includes a body 11 having a gas flow path and a plurality of valve sub-assemblies assembled to the body 11. The gas flow path includes a first flow path 12 connected to the gas tank 2 and a second flow path 13 connected to the external device 3. The plurality of valve sub-assemblies includes, for example, a manual valve 14, a combined valve 15, a safety valve 16, a check valve 17, and an overcurrent prevention valve 18. The plurality of valve sub-assemblies may also include any valve assembly based on or instead of these valve sub-assemblies.

[0025] (Body)

[0026] The body 11 includes a main body 21 and a joint 22. The main body 21 is made of, for example, a metallic material. The main body 21 is, for example, in the shape of a rectangular parallelepiped with a part thereof protruding. The outer surface of the main body 21 includes a first side surface 21a, a second side surface 21b, a third side surface 21c, and a fourth side surface 21d. The first side surface 21a and the third side surface 21c are, for example, parallel to each other. The second side surface 21b and the fourth side surface 21d are, for example, parallel to each other. The first side surface 21a and the third side surface 21c are, for example, orthogonal to the second side surface 21b and the fourth side surface 21d.

[0027] The main body 21 has a plurality of mounting holes corresponding to the components mounted on the main body 21. The plurality of mounting holes includes, for example, a joint mounting hole 24 for mounting the joint 22, a manual valve mounting hole 25 for mounting the manual valve 14, a combined mounting hole 26 for mounting the safety valve 16 and the check valve 17, and a combined valve mounting hole 27 for mounting the combined valve 15. The joint mounting hole 24 is, for example, a round hole and opens on the first side surface 21a. The manual valve mounting hole 25 is, for example, a round hole and opens on the second side surface 21b. The combined mounting hole 26 is, for example, a round hole and opens on the third side surface 21c. The combined valve mounting hole 27 is, for example, a round hole and opens on the fourth side surface 21d.

[0028] The first flow path 12 includes a filling portion 31 that connects the integrated mounting hole 26 to the gas tank 2 and a delivery portion 32 that connects the mounting hole 27 for the composite valve to the gas tank 2. The filling portion 31 opens, for example, on the inner peripheral surface of the integrated mounting hole 26. Accordingly, the safety valve 16 and the check valve 17 are connected to the gas tank 2 via the filling portion 31. The delivery portion 32 opens, for example, on the inner peripheral surface of the mounting hole 27 for the composite valve. Thereby, the composite valve 15 is connected to the gas tank 2 via the delivery portion 32. As shown in the figure, the filling portion 31 and the delivery portion 32 may also be independent flow paths from each other.

[0029] The second flow path 13 includes a first portion 33, a second portion 34, a third portion 35, a fourth portion 36, and a joint flow path 37. The first portion 33, the second portion 34, the third portion 35, and the fourth portion 36 are provided in the main body 21. The joint flow path 37 is provided in the joint 22 as will be described later.

[0030] The first portion 33 opens at the bottom surface of the mounting hole 24 for the joint. The second portion 34 opens at the bottom surface of the mounting hole 25 for the manual valve. The first portion 33 and the second portion 34 extend, for example, linearly. The second portion 34 is orthogonal to the first portion 33. The inner diameter of the portion of the second portion 34 that is closer to the inside than the crossing position with the first portion 33 is smaller than the inner diameter of the portion near the crossing position. The third portion 35 opens, for example, at the bottom surface of the integrated mounting hole 26. The third portion 35 connects the second portion 34 to the integrated mounting hole 26. The fourth portion 36 opens, for example, at the bottom surface of the mounting hole 27 for the composite valve. The fourth portion 36 connects the second portion 34 to the mounting hole 27 for the composite valve. The third portion 35 and the fourth portion 36 extend, for example, linearly.

[0031] As shown in the figure, the third portion 35 is orthogonal to, for example, the small-diameter portion of the second portion 34. The fourth portion 36 is provided coaxially with the second portion 34, for example. In addition, the structure of the second flow path 13 is not limited to the illustrated example and can be appropriately changed. For example, the third portion 35 may be orthogonal to the large-diameter portion of the second portion 34 in such a manner as to be arranged coaxially with the first portion 33. Also, the fourth portion 36 may be orthogonal to the second portion 34, for example.

[0032] The joint 22 is made of a metal material, for example. The joint 22 is cylindrical in shape, for example. The joint 22 has a joint flow path 37 that serves as a gas flow path. The joint flow path 37 extends linearly along the axial direction of the joint 22, for example, and opens at both end faces of the joint 22. The joint 22 is fixed to the joint mounting hole 24 by any fixing method such as screw fastening or press-fitting. Thus, the joint flow path 37 communicates with the first part 33. Either the pipe 6 or 7 is connected to the joint 22. Thus, the second flow path 13 is connected to the supply source 4 or the consumption device 5. An overcurrent prevention valve 18 is provided in the joint flow path 37. That is, the joint 22 corresponds to a flow path forming member, and the assembly composed of the joint 22 and the overcurrent prevention valve 18 corresponds to an overcurrent prevention valve device. Therefore, the valve assembly 1 includes an overcurrent prevention valve device.

[0033] (Multiple valve sub-assemblies)

[0034] The manual valve 14 is fixed to the manual valve mounting hole 25 by any fixing method such as screw fastening or press-fitting. The manual valve 14 is configured to be able to block the second part 34 of the second flow path 13 by the operation of the user.

[0035] The safety valve 16 is configured to be in a closed state when the temperature of the safety valve 16 is below the threshold temperature. The safety valve 16 does not release the hydrogen in the gas cylinder 2 to the outside in the closed state. On the other hand, the safety valve 16 is configured to irreversibly change from the closed state to the open state when the temperature of the safety valve 16 exceeds the threshold temperature. The safety valve 16 releases the hydrogen in the gas cylinder 2 to the outside in the open state. The threshold temperature is preset in such a way that the pressure of the hydrogen in the gas cylinder 2 does not become too high and the gas cylinder 2 is not damaged.

[0036] The check valve 17 is configured to prevent the hydrogen filled in the gas cylinder 2 from flowing back. Specifically, the flow of hydrogen from the filling part 31 of the first flow path 12 to the third part 35 of the second flow path 13 is restricted, and the flow of hydrogen from the third part 35 to the filling part 31 is allowed.

[0037] The composite valve 15 has an electromagnetic valve part that functions as an electromagnetic valve and a check valve part that functions as a check valve. The composite valve 15 controls the flow of hydrogen between the delivery part 32 of the first flow path 12 and the fourth part 36 of the second flow path 13 by opening and closing the electromagnetic valve part. The check valve part allows the hydrogen to flow from the delivery part 32 to the fourth part 36 and restricts the flow of hydrogen from the fourth part 36 to the delivery part 32. Thus, when filling hydrogen from the supply source 4 into the gas cylinder 2, the high-pressure hydrogen acting on the electromagnetic valve part is suppressed.

[0038] The overcurrent prevention valve 18 is configured to restrict the flow of hydrogen when the flow rate of hydrogen flowing in the joint flow path 37 (second flow path 13) in a specified direction exceeds a predetermined specified amount. The specified direction is the direction in which hydrogen is sent from the gas tank 2 to the consuming device 5. The overcurrent prevention valve 18 does not restrict the flow rate of hydrogen in the direction opposite to the specified direction, that is, the direction in which hydrogen is filled from the supply source 4 into the gas tank 2. The details of the overcurrent prevention valve 18 will be described later.

[0039] (Operation of the valve assembly)

[0040] When filling hydrogen into the gas tank 2, the supply source 4 is connected to the joint 22 via the pipe 6. When hydrogen is supplied from the supply source 4, the hydrogen flows into the check valve 17 via the joint flow path 37, the first part 33, the second part 34, and the third part 35 of the second flow path 13. As described above, the check valve 17 is configured to allow hydrogen to flow from the third part 35 to the filling part 31, so it is in an open state. Therefore, hydrogen is filled into the gas tank 2 via the filling part 31. At this time, hydrogen also flows from the second part 34 of the second flow path 13 into the check valve part of the composite valve 15 via the fourth part 36. However, the check valve part is configured to restrict the flow of hydrogen from the fourth part 36 to the delivery part 32, so it is in a closed state. Thereby, hydrogen does not flow from the second flow path 13 into the delivery part 32.

[0041] When sending hydrogen to the consuming device 5, the consuming device 5 is connected to the joint 22 via the pipe 7. The hydrogen in the gas tank 2 flows into the composite valve 15 via the delivery part 32 of the first flow path 12. When the solenoid valve part of the composite valve 15 is controlled to be in an open state, hydrogen flows into the check valve part. The check valve part is configured to allow hydrogen to flow from the delivery part 32 to the fourth part 36, so it is in an open state. Thereby, hydrogen flows into the fourth part 36, the second part 34, the first part 33, and the joint flow path 37 of the second flow path 13, and is sent to the consuming device 5 via the pipe 7. At this time, hydrogen also flows from the second part 34 of the second flow path 13 into the check valve 17 via the third part 35. However, the check valve 17 is configured to restrict the flow of hydrogen from the filling part 31 to the third part 35, so it is in a closed state. Thereby, hydrogen does not flow from the third part 35 into the filling part 31.

[0042] In this way, the second flow path 13 is used as a hydrogen filling path and a hydrogen supply path. In other words, a part of the hydrogen filling path and a part of the hydrogen supply path are shared.

[0043] (Overcurrent prevention valve device)

[0044] As Figure 2As shown, an overcurrent prevention valve 18 is provided in the joint flow path 37 of the joint 22. The overcurrent prevention valve 18 includes: a valve seat 41 provided in the middle of the joint flow path 37; a valve element 42 slidably accommodated in the joint flow path 37; and a biasing member 43 that biases the valve element 42 in a direction away from the valve seat 41. As shown in the figure, the overcurrent prevention valve 18 may also include a stopper 44 that defines the movement range of the valve element 42. In addition, the overcurrent prevention valve 18 may include a filter 45 and a pressing member 46 regardless of the presence or absence of the stopper 44. Moreover, the overcurrent prevention valve 18 may include a sealing member 47 regardless of the presence or absence of the stopper 44, and also regardless of the presence or absence of the filter 45 and the pressing member 46. In the following description, the side of the joint flow path 37 connected to the first part 33 of the second flow path 13 is referred to as the first side, and the opposite side thereof, that is, the side of the joint flow path 37 connected to the pipe 7, is referred to as the second side.

[0045] For example, as shown in the figure, the joint flow path 37 is linear along the axial direction of the joint 22. The joint flow path 37 of the present embodiment has a stepped shape in which the inner diameter decreases stepwise from the first side toward the second side. Specifically, the joint flow path 37 sequentially has a sealing member accommodation portion 51, a filter accommodation portion 52, a valve element accommodation portion 53, and a small-diameter flow path portion 54 from the first side. The inner diameter of the joint flow path 37 decreases in the order of the sealing member accommodation portion 51, the filter accommodation portion 52, the valve element accommodation portion 53, and the small-diameter flow path portion 54. A circumferentially extending locking groove 55 is provided at the end on the first side of the inner peripheral surface of the valve element accommodation portion 53. The stepped portion between the valve element accommodation portion 53 and the small-diameter flow path portion 54 is used as the above-mentioned valve seat 41 on which the valve element 42 seats. And, the end on the first side of the small-diameter flow path portion 54 is used as the valve port 56. That is, a part of the joint 22 that is seamlessly continuous with other parts constitutes the valve seat 41. In other words, the joint 22 is an integral one-piece having the joint flow path 37 and the valve seat 41. As shown in the figure, the inner peripheral edge of the valve seat 41 may be chamfered into a conical shape. The axial length of the small-diameter flow path portion 54 is set to be substantially equal to the axial length of the valve element accommodation portion 53. In other embodiments, the axial length of the small-diameter flow path portion 54 may also be set to be shorter or longer than the axial length of the valve element accommodation portion 53.

[0046] The sealing member 47 is made of, for example, a rubber material or a resin material. The sealing member 47 is annular. In the present embodiment, the sealing member 47 has a circular shape when viewed in the axial direction. The sealing member 47 is fitted into the sealing member accommodation portion 51. Moreover, by installing the joint 22 in the joint mounting hole 24, the sealing member 47 is in close contact with the bottom surface of the joint mounting hole 24. Thereby, the space between the main body 21 and the joint 22 is sealed.

[0047] The filter 45 is made of, for example, a wire mesh or the like. The filter 45 has a circular shape when viewed axially. The pressing member 46 is made of, for example, a metallic material. The pressing member 46 has an annular shape. In the present embodiment, the pressing member 46 has a circular shape when viewed axially. The filter 45 is disposed within the filter housing portion 52. Further, the filter 45 is fixed within the filter housing portion 52 by being pressed from the first side by the pressing member 46 that is fitted into the filter housing portion 52.

[0048] The stopper 44 is made of, for example, a metallic material. The stopper 44 has an annular shape. In the present embodiment, the stopper 44 has a C-shaped configuration when viewed axially. The stopper 44 is, for example, a snap ring. The stopper 44 is fixed within the valve element housing portion 53 by engaging with the engagement groove 55 of the valve element housing portion 53.

[0049] As Figure 2 , Figure 3 and Figure 4 shown, the valve element 42 is a lift valve having a substantially columnar shape. The valve element 42 is housed within the valve element housing portion 53 such that its axial direction is along the length direction of the joint flow path 37. Additionally, the valve element housing portion 53 is sometimes referred to as a valve chamber. The valve element 42 is made of, for example, a metallic material. The valve element 42 has a base portion 61, a plurality of leg portions 62 that are continuous with the first side of the base portion 61, a mounting portion 63 that is continuous with the second side of the base portion 61, a head portion 64 that is continuous with the second side of the mounting portion 63, and a protrusion portion 65 that is continuous with the second side of the head portion 64.

[0050] Specifically, the base portion 61 has a quadrangular plate shape. The leg portions 62 are provided at each corner of the base portion 61. That is, the valve element 42 has four leg portions 62. Each leg portion 62 has a quadrangular prism shape. The ridge line portions corresponding to the corners of the base portion 61 in each leg portion 62 may be chamfered as shown in the figure. The ridge line portions contact the inner peripheral surface of the valve element housing portion 53 in a slidable manner. The mounting portion 63 has a cylindrical shape. The outer diameter of the mounting portion 63 is set to be one size smaller than the diameter of the circle inscribed in the base portion 61. The head portion 64 has a conical shape whose outer diameter decreases toward the second side. The protrusion portion 65 has a cylindrical shape. The protrusion portion 65 protrudes from the front end of the head portion 64 toward the second side. The outer diameter of the protrusion portion 65 is set to be smaller than the inner diameter of the small-diameter flow path portion 54, that is, the inner diameter of the valve port 56. Thereby, the head portion 64 seats on the valve seat 41, thereby closing the valve port 56. In a state where the head portion 64 seats on the valve seat 41, the protrusion portion 65 is inserted into the valve port 56.

[0051] Further, the valve element 42 of the present embodiment has a through-hole 66 penetrating axially therethrough. The through-hole 66 extends throughout the base portion 61, the head portion 64, and the protrusion portion 65. Thus, even when the valve element 42 is seated on the valve seat 41, hydrogen is sent out from the joint 22. That is, the check valve 18 is configured to allow hydrogen to flow through the check valve 18 even when the valve element 42 is seated on the valve seat 41, i.e., in the closed state. In addition, the inner diameter of the through-hole 66 is set to be smaller than the inner diameter of the small-diameter flow path portion 54. Therefore, the flow rate of hydrogen when the check valve 18 is in the closed state is smaller than the flow rate of hydrogen when the check valve 18 is in the open state.

[0052] The biasing member 43 is, for example, a helical spring. The biasing member 43 is compressed between the base portion 61 and the outer peripheral edge of the valve seat 41 in a state of being mounted on the outer periphery of the mounting portion 63. Thus, the biasing member 43 always biases the valve element 42 in the first side, i.e., the direction in which the valve element 42 moves away from the valve seat 41.

[0053] The valve element 42 is subjected to a force corresponding to the pressure difference between the pressure on its upstream side and the pressure on its downstream side (hereinafter, differential pressure preloading force). Therefore, the valve element 42 slides in the joint flow path 37 according to the differential pressure preloading force and the mechanical preloading force of the biasing member 43.

[0054] When sending hydrogen to the consuming device 5, the first side of the valve element 42 becomes the upstream side, and the second side of the valve element 42 becomes the downstream side. Therefore, the valve element 42 is subjected to the upstream pressure on the side surface of the first side of the base portion 61 and the end surfaces of the respective leg portions 62 and is biased toward the downstream side (the second side). In addition, the valve element 42 is subjected to the downstream pressure on the side surface of the second side of the base portion 61, the tapered surface of the head portion 64, and the end surface of the protrusion portion 65 and is biased toward the upstream side (the first side). At this time, in the portion of the valve element receiving portion 53 where the base portion 61 of the valve element 42 is disposed, the flow path cross-sectional area is smaller than that of other portions. Therefore, with the position of the base portion 61 as the boundary, the pressure in the space on the second side in the valve element receiving portion 53 becomes smaller than the pressure in the space on the first side. In addition, the flow path cross-sectional area of the valve port 56 is smaller than the flow path cross-sectional area of the valve element receiving portion 53, so the pressure in the valve port 56 is smaller than the pressure in the valve element receiving portion 53. That is, the differential pressure preloading force when sending hydrogen to the consuming device 5 biases the valve element 42 in the direction approaching the valve seat 41 (the downstream side).

[0055] Here, the mechanical pre-tightening force of the force-applying member 43 is set such that, for example, if there is no abnormality in the pipe 7 connected to the overcurrent prevention valve 18 and the pressure difference is within the normal range, it becomes larger than the differential pressure pre-tightening force corresponding to this pressure difference. Therefore, the valve element 42 moves away from the valve seat 41, and thus the overcurrent prevention valve 18 becomes an open state. At this time, by the leg portion 62 abutting against the stopper 44, the further movement of the valve element 42 toward the first side is restricted. The position of this valve element 42 is the position farthest from the valve seat 41 and is the open position of the valve element 42. On the other hand, for example, when the pressure on the downstream side decreases sharply due to damage to the pipe 7 and the pressure difference becomes too large, the differential pressure pre-tightening force corresponding to this pressure difference becomes larger than the mechanical pre-tightening force. As a result, the valve element 42 slides toward the second side and seats on the valve seat 41, whereby the overcurrent prevention valve 18 becomes a closed state. Thus, the position where the valve element 42 seats on the valve seat 41 is the closed position of the valve element 42.

[0056] The overcurrent prevention valve 18 of the present embodiment is configured such that the movement range of the valve element 42 between the open position and the closed position includes a first transition range and a second transition range. The first transition range is the range in which the valve element 42 moves in a state where the entire protrusion 65 is disposed within the valve element receiving portion 53. The second transition range is the range in which the valve element 42 moves in a state where at least a part of the protrusion 65 is disposed within the valve port 56. In the present embodiment, the size of the valve element 42 is set such that the size of the first transition range is substantially equal to the size of the second transition range.

[0057] Specifically, the length of the valve element 42 along the axial direction is set to be shorter than the length along the axial direction from the valve seat 41 to the stopper 44 in the valve element receiving portion 53. In addition, the length of the protrusion 65 along the axial direction is set to be the length at which the front end of the protrusion 65 is inserted into the valve port 56 when the axial distance between the head 64 and the valve seat 41 and the axial distance between the leg portion 62 and the stopper 44 are substantially equal.

[0058] (Operation of the overcurrent prevention valve device)

[0059] The operation of the overcurrent prevention valve device when the valve element 42 moves from the open position to the closed position due to an abnormality in the pipe 7 during the delivery of hydrogen will be described.

[0060] When the valve element 42 is in the open position or within the first transition range, the head 64 and the entire protrusion 65 of the valve element 42 are disposed within the valve element receiving portion 53. Therefore, the differential pressure pre-tightening force is determined only by the pressure within the valve element receiving portion 53. As described above, although the pressure in the space on the second side in the valve element receiving portion 53 becomes smaller than the pressure in the space on the first side, the pressure difference is difficult to become relatively large under normal conditions. That is, the force in the direction of bringing the valve element 42 closer to the valve seat 41, i.e., the differential pressure pre-tightening force, is difficult to become large.

[0061] Therefore, asFigure 5 As shown, for example, even if the pressure of the hydrogen gas sent out fluctuates and causes the valve element 42 to slide slightly toward the second side, it is difficult for the valve element 42 to slide beyond the first transition range and toward the second side.

[0062] In contrast, for example, if an abnormality occurs in the pipe 7 and the pressure in the pipe 7 suddenly decreases, the differential pressure preloading force increases. Then, as Figure 6 shown, the valve element 42 moves beyond the first transition range and into the second transition range. In this case, since the protrusion 65 is inserted into the valve port 56, the pressure in the valve port 56 rather than the pressure in the valve element receiving portion 53 acts on the protrusion 65. Therefore, within the second transition range, the differential pressure preloading force is determined by the pressure in the valve element receiving portion 53 and the pressure in the valve port 56. When hydrogen gas is sent out as described above, the pressure in the valve port 56 is less than the pressure in the valve element receiving portion 53, so the differential pressure is likely to increase. That is, the differential pressure preloading force is likely to increase.

[0063] Therefore, when the valve element 42 is within the second transition range, the valve element 42 is likely to slide to the closed position. In particular, the closer the valve element 42 is to the closed position, the smaller the gap between the head 64 of the valve element 42 and the valve seat 41, so the pressure in the valve port 56 further decreases. As a result, the differential pressure preloading force is more likely to increase. Consequently, the valve element 42 quickly moves toward the second side, and as Figure 7 shown, the valve element 42 moves toward the closed position, and the overcurrent prevention valve 18 becomes the closed state.

[0064] Next, the operation and effects of the present embodiment will be described.

[0065] (1) The movement range of the valve element 42 includes the first transition range that is continuous from the open position toward the second side and where the differential pressure preloading force is difficult to increase. Therefore, in order for the valve element 42 to move beyond the first transition range and into the second transition range, it is necessary to make the pressure difference between the pressure on the upstream side and the pressure on the downstream side of the valve element 42 large enough. Therefore, it is difficult for the valve element 42 to accidentally move into the second transition range, and the open state can be stably maintained during normal times. In addition, the movement range of the valve element 42 includes the second transition range that is continuous from the first transition range toward the second side and where the differential pressure preloading force is easy to increase. Therefore, after the pressure difference becomes large enough due to an abnormality in the pipe 7 or the like and the valve element 42 moves into the second transition range, the overcurrent prevention valve 18 can be quickly switched to the closed state.

[0066] (2) The size of the first transition range is approximately equal to the size of the second transition range. Therefore, compared with the case where the first transition range is smaller than the second transition range, the distance between the head 64 of the spool 42 and the valve seat 41 in the state where the spool 42 is in the open position can be increased. Thereby, it is possible to suppress, for example, an increase in the pressure loss between the head 64 and the valve seat 41 when hydrogen is sent out, and hydrogen can be appropriately sent to the consuming device 5.

[0067] (3) The overcurrent prevention valve 18 is configured to allow hydrogen to flow through the overcurrent prevention valve 18 in a state where the spool 42 is seated on the valve seat 41. Therefore, for example, in the case where the pipe 7 is damaged and an abnormality occurs in which the check valve 17 is fixed in the open state, a rapid leakage of hydrogen from the gas tank 2 can be suppressed.

[0068] This embodiment can be implemented with the following changes. This embodiment and the following modification examples can be implemented in combination with each other within a range where there is no technical contradiction.

[0069] · The spool 42 has a fine hole 66, and the overcurrent prevention valve 18 is configured to send out hydrogen even when the overcurrent prevention valve 18 is in the closed state. However, it is not limited thereto. For example, the overcurrent prevention valve 18 may be configured such that a groove is formed in at least one of the outer peripheral surface of the head 64 of the spool 42 and the inner peripheral surface of the valve port 56, so that hydrogen is sent out even when the overcurrent prevention valve 18 is in the closed state. In addition, the overcurrent prevention valve 18 may be configured not to send out hydrogen when the overcurrent prevention valve 18 is in the closed state.

[0070] · The structure of the spool 42 can be appropriately changed. For example, the base portion 61 may be formed in a disk shape, or the number of the leg portions 62 may be changed, etc., to change the shape and number of each part of the spool 42. In addition, as long as the spool 42 has at least the head 64 and the protrusion portion 65, for example, it may not have the base portion 61, the leg portions 62, and the mounting portion 63.

[0071] · The size of the first transition range can be set to be larger than the size of the second transition range, or can be set to be smaller than the size of the second transition range.

[0072] · The stopper 44 is fixed within the spool housing portion 53, but it is not limited thereto, and the stopper 44 may be fixed outside the spool housing portion 53.

[0073] · In the overcurrent prevention valve 18, for example, the filter 45 may be pressed by the sealing member 47. In this case, the overcurrent prevention valve 18 may not have the pressing member 46 that is separate from the sealing member 47. In addition, the overcurrent prevention valve 18 may not have the filter 45. And the overcurrent prevention valve 18 may not have the sealing member 47.

[0074] · The joint 22 is an integral part having a joint flow path 37 and a valve seat 41. However, it is not limited thereto, and a valve seat formed of a member different from the joint 22 may be fixed within the joint flow path 37. The structure of the joint flow path 37 can be appropriately changed according to the structure of the overcurrent prevention valve 18.

[0075] · The overcurrent prevention valve 18 may be installed not within the joint 22 but within the main body 21.

[0076] · The overcurrent prevention valve device may be used independently of the valve assembly 1. In this case, the flow path forming member forming the gas flow path may also be a member other than the joint 22.

[0077] · The valve assembly 1 controls the flow of high-pressure hydrogen. However, it is not limited thereto, and it may also control the flow of gases other than hydrogen.

[0078] Next, the technical ideas that can be grasped based on the above-described embodiments and modified examples are additionally described below.

[0079] (Supplementary Note 1) The valve element is columnar and has a fine hole penetrating along the axial direction of the valve element, and the fine hole extends throughout the head portion and the protrusion portion.

[0080] (Supplementary Note 2) The overcurrent prevention valve includes a stopper that restricts the opening position of the valve element.

[0081] (Supplementary Note 3) The gas flow path has a small-diameter flow path portion that is continuous with the valve element housing portion and has a smaller flow path cross-sectional area than the valve element housing portion. The stepped portion between the valve element housing portion and the small-diameter flow path portion is used as the valve seat, and the end portion of the small-diameter flow path portion is used as the valve port.

Claims

1. An overcurrent prevention valve device, comprising: a flow path forming member having a gas flow path; and an overcurrent prevention valve configured to restrict the flow of gas when the flow rate of the gas flowing through the gas flow path in a specified direction exceeds a specified amount, wherein, the gas flow path has a valve element receiving portion that houses at least a part of the overcurrent prevention valve, the overcurrent prevention valve includes: a valve seat provided in the valve element receiving portion and having a valve port; a valve element configured to be slidably received in the valve element receiving portion; and a biasing member configured to bias the valve element in a direction away from the valve seat, the valve element has: a head configured to block the valve port by seating on the valve seat; and a protrusion configured to protrude from the head and insert into the valve port, the position of the valve element farthest from the valve seat is the open position, and the position where the valve element seats on the valve seat is the closed position, the movement range of the valve element between the open position and the closed position includes a first transition range and a second transition range, the first transition range is the range in which the valve element moves in a state where the entire protrusion is disposed in the valve element receiving portion, the second transition range is the range in which the valve element moves in a state where at least a part of the protrusion is disposed in the valve port.

2. The overcurrent prevention valve device according to claim 1, wherein, the size of the first transition range is equal to the size of the second transition range.

3. The overcurrent prevention valve device according to claim 1 or 2, wherein, the overcurrent prevention valve is configured to allow gas to flow through the overcurrent prevention valve in a state where the valve element seats on the valve seat.

4. A valve assembly, comprising: a body having a gas flow path including a first flow path and a second flow path; and an overcurrent prevention valve configured to restrict the flow of gas when the flow rate of the gas flowing through the second flow path in a specified direction exceeds a specified amount, wherein, the first flow path is configured to be connected to a gas tank storing gas, the second flow path is configured to be selectively connected to any one of a plurality of external devices, the plurality of external devices include a supply source of gas filled into the gas tank and a consumption device that consumes the gas sent out from the gas tank, the second flow path has a valve element receiving portion that houses at least a part of the overcurrent prevention valve, the specified direction is the direction of sending gas to the consumption device, the overcurrent prevention valve includes: a valve seat provided in the valve element receiving portion and having a valve port; a valve element configured to be slidably received in the valve element receiving portion; and a biasing member configured to bias the valve element in a direction away from the valve seat, the valve element has: a head configured to block the valve port by seating on the valve seat; and a protrusion configured to protrude from the head and insert into the valve port, the position of the valve element farthest from the valve seat is the open position, and the position where the valve element seats on the valve seat is the closed position, the movement range of the valve element between the open position and the closed position includes a first transition range and a second transition range, The first transition range is the range in which the valve element moves in a state where the protrusion is entirely disposed in the valve element receiving portion. The second transition range is the range in which the valve element moves in a state where at least a part of the protrusion is disposed within the valve port.

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