Excess flow valve device and valve assembly

Abstract

An excess flow valve (18) restricts the flow of a gas flowing in a specific direction through a gas flow passage when the flow rate of the gas exceeds a predetermined flow rate. The excess flow valve has a valve seat (41), a valve body (42), a biasing member (43), and a stopper (44). The valve body (42) has a valve portion (61), a receiving portion (64), and a valve body flow passage (65). The stopper is an annular member having a cutout (44A) in a part of the ring, and is attached inside a valve body housing portion (53) such that the gas passes through the cutout. The cutout is configured so that when the gas flows through the gap between the outer peripheral surface of the valve body and the inner peripheral surface of the valve body housing portion in a direction opposite to the specific direction, the action of the gas passing through the cutout causes an imbalance of pressure distribution around the valve body. The gap between the outer peripheral surface of the valve body and the inner peripheral surface of the valve body housing portion is set to a size such that the valve body is pressed against the inner peripheral surface of the valve body housing portion when radial force acts on the valve body due to the imbalance of pressure distribution around the valve body.

Description

Excess flow valve device and valve assembly

[0001] The present disclosure relates to excess flow valve devices and valve assemblies.

[0002] Conventionally, there are valve devices that control the flow of gas. For example, the valve device disclosed in Patent Document 1 is installed in a gas tank of a fuel cell vehicle. The valve device controls the flow of high-pressure hydrogen gas filled in the gas tank. The valve device has a body, a check valve, and an excess flow valve. The body has a gas flow path that connects the inside and outside of the gas tank. The check valve prevents the backflow of hydrogen gas supplied from the gas supply path to the gas tank. The excess flow valve prevents the hydrogen gas in the gas tank from suddenly leaking out if an abnormality occurs in the check valve.

[0003] The excess flow valve has a valve seat provided in the gas supply passage, a valve element that moves toward and away from the valve seat, and a coil spring that biases the valve element toward the valve seat. When filling the gas tank with hydrogen gas, hydrogen gas is supplied from the supply passage. The pressure of the hydrogen gas causes the valve element to move away from the valve seat against the biasing force of the coil spring. This allows hydrogen gas supplied through the supply passage to fill the gas tank. Furthermore, when hydrogen gas is not being filled into the gas tank, hydrogen gas is not supplied from the supply passage. Therefore, the biasing force of the coil spring causes the valve element to seat on the valve seat.

[0004] The valve body has microscopic holes that penetrate the valve body in the axial direction. Therefore, even when the valve body is seated on the valve seat, the flow of hydrogen gas is not completely blocked. A small amount of hydrogen gas can flow from the gas tank through the microscopic holes to the supply path and ultimately to the outside of the body. Therefore, even if an abnormality occurs in the check valve, the hydrogen gas in the gas tank is gradually released to the outside of the body through the microscopic holes. In other words, the hydrogen gas in the gas tank is prevented from suddenly leaking to the outside of the body. An abnormality could be, for example, the check valve being stuck in the open position.

[0005] Japanese Patent Application Laid-Open No. 2019-190516

[0006] In the excess flow prevention valve of Patent Document 1, there is a risk that the valve body will vibrate when a large flow rate of hydrogen gas is filled into the gas tank.

[0007] An excess flow valve device according to one aspect of the present disclosure includes a flow path forming member having a gas flow path and an excess flow valve configured to restrict the flow of gas when the flow rate of gas flowing through the gas flow path in a specific direction exceeds a predetermined flow rate. The gas flow path includes a valve element housing portion that houses the excess flow valve. The excess flow valve includes a valve seat provided in the valve element housing portion, the valve seat having a valve opening, a valve element movably housed in the valve element housing portion, a biasing member configured to bias the valve element in a direction away from the valve seat, and a stopper configured to define one end of a movement range of the valve element. The valve element includes a valve portion configured to seat on the valve seat to close the valve opening, a receiving portion configured to support the biasing member, and a valve element flow path that penetrates the valve element in the movement direction of the valve element, the valve element flow path being disposed between the valve portion and the receiving portion in a direction perpendicular to the movement direction. The stopper is an annular member having a notch in a portion of the annulus, and is attached inside the valve body accommodating portion so that gas passes through the notch. The notch is configured so that, when gas flows through the gap between the outer circumferential surface of the valve body and the inner circumferential surface of the valve body accommodating portion in a direction opposite to the specific direction, the gas passing through the notch causes a bias in the pressure distribution around the valve body. The gap between the outer circumferential surface of the valve body and the inner circumferential surface of the valve body accommodating portion is set to a size such that, when a radial force acts on the valve body due to a bias in the pressure distribution around the valve body, the valve body is pressed against the inner circumferential surface of the valve body accommodating portion.

[0008] A valve assembly according to one 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 excess flow valve configured to restrict the flow of gas when the flow rate of gas flowing in a specific direction through the second flow path exceeds a predetermined flow rate. The first flow path is configured to be connected to a gas tank that stores 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 gas supply source for filling the gas tank and a consumer device that consumes gas released from the gas tank. The second flow path has a valve body housing that houses the excess flow valve. The specific direction is the direction in which gas is released to the consumer device. The excess flow valve includes a valve seat provided in the valve body housing, the valve seat having a valve port, a valve body movably housed in the valve body housing, a biasing member configured to bias the valve body in a direction away from the valve seat, and a stopper configured to define one end of a range of movement of the valve body. The valve element includes a valve portion configured to close the valve port by seating on the valve seat, a receiving portion configured to support the biasing member, and a valve element flow path that penetrates the valve element in the movement direction of the valve element and is disposed between the valve portion and the receiving portion in a direction perpendicular to the movement direction. The stopper is an annular member having a notch in a portion of the ring and is attached to the inside of the valve element accommodating portion so that gas passes through the notch. The notch is configured to cause a bias in the pressure distribution around the valve element by the action of the gas passing through the notch when gas flows through the gap between the outer circumferential surface of the valve element and the inner circumferential surface of the valve element accommodating portion in a direction opposite to the specific direction. The gap between the outer circumferential surface of the valve element and the inner circumferential surface of the valve element accommodating portion is set to a size such that the valve element is pressed against the inner circumferential surface of the valve element accommodating portion when a radial force acts on the valve element due to a bias in the pressure distribution around the valve element.

[0009] FIG. 1 is a cross-sectional view showing the configuration of a valve assembly of one embodiment. FIG. 2 is an enlarged cross-sectional view of the vicinity of the excess flow valve of the valve assembly of FIG. 1. FIG. 3 is a perspective view of the valve body of the excess flow valve of FIG. 2, seen from the first end side of the fitting. FIG. 4 is a perspective view of the valve body of the excess flow valve of FIG. 2, seen from the second end side of the fitting. FIG. 5 is a schematic diagram showing the flow of hydrogen gas passing through the excess flow valve of FIG. 2 when filling hydrogen gas. FIG. 6 is a cross-sectional view of the excess flow valve of FIG. 5, taken along line 6-6. FIG. 7 is a cross-sectional view of the excess flow valve of FIG. 5, taken along line 7-7, showing the first initial position of the valve body before starting to fill the gas tank with hydrogen gas. FIG. 8 is a cross-sectional view of the excess flow valve of FIG. 5, taken along line 7-7, showing the second initial position of the valve body before starting to fill the gas tank with hydrogen gas. FIG. 9 is a cross-sectional view of the excess flow valve of FIG. 5, taken along line 7-7, showing the third initial position of the valve body before starting to fill the gas tank with hydrogen gas. FIG. 10 is a cross-sectional view of the excess flow valve taken along line 7-7 of FIG. 5, showing the position of the valve body after starting to fill the gas tank with hydrogen gas.

[0010] An excess flow valve device and a valve assembly according to one embodiment will now be described. <Overall Configuration> As shown in FIG. 1 , the valve assembly 1 is attached to a gas tank 2 of, for example, a fuel cell vehicle. The gas tank 2 stores high-pressure hydrogen gas, for example, about 72.5 MPa. The valve assembly 1 is selectively connected to one of a plurality of external devices 3. The external device 3 includes a supply source 4 and a consumer device 5. The supply source 4 is a facility that supplies hydrogen gas to be filled into the gas tank 2, such as a hydrogen station. The supply source 4 is connected to the valve assembly 1 via a first pipe 6. The consumer device 5 is a device that consumes hydrogen gas released from the gas tank 2, such as a fuel cell installed in the vehicle. The consumer device 5 is connected to the valve assembly 1 via a second pipe 7. The valve assembly 1 controls the flow of hydrogen gas filled into the gas tank 2 and the flow of hydrogen gas released from the gas tank 2.

[0011] The valve assembly 1 includes a body 11 and a plurality of valve subassemblies. The valve assembly 1 is formed by assembling the body 11 and a plurality of valve subassemblies so that they can be handled as a single unit. The valve subassemblies are subassemblies. A subassembly is formed by assembling components that constitute a specific functional part so that they can be handled as a single unit. The body 11 has a gas flow path. The gas flow path includes a first flow path 12 connected to a gas tank 2 and a second flow path 13 connected to an external device 3. The valve subassemblies include a manual valve 14, a combined valve 15, a safety valve 16, a check valve 17, and an excess flow valve 18. The valve subassembly may include any valve subassembly in addition to or instead of these valve subassemblies.

[0012] <Body 11> Next, a detailed description will be given of the configuration of the body 11. As shown in FIG.

[0013] The main body 21 is made of, for example, metal. The main body 21 is, for example, a box-shaped body having a rectangular cross-sectional shape, with a portion of the main body 21 protruding laterally. 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 extend, for example, in a direction perpendicular to the second side surface 21b and the fourth side surface 21d.

[0014] The main body 21 has a plurality of mounting holes. The mounting holes are provided according to the components to be mounted to the main body 21. The mounting holes include a fitting mounting hole 24, a manual valve mounting hole 25, an integrated mounting hole 26, and a combined valve mounting hole 27. The fitting mounting hole 24 is a hole for mounting the fitting 22. The fitting mounting hole 24 is a hole with a circular cross-sectional shape and opens to the first side surface 21a. The manual valve mounting hole 25 is a hole for mounting the manual valve 14. The manual valve mounting hole 25 is a hole with a circular cross-sectional shape and opens to the second side surface 21b. The integrated mounting hole 26 is a hole for mounting the safety valve 16 and the check valve 17. The integrated mounting hole 26 is a hole with a circular cross-sectional shape and opens to the third side surface 21c. The combined valve mounting hole 27 is a hole for mounting the combined valve 15. The combined valve mounting hole 27 is a hole having a circular cross section and opens to the fourth side surface 21d.

[0015] The first flow path 12 includes a filling portion 31 and a discharge portion 32. The filling portion 31 is a portion of the first flow path 12 that connects the integrated mounting hole 26 and the gas tank 2. The filling portion 31 opens to the inner circumferential surface of the integrated mounting hole 26. The safety valve 16 and the check valve 17 are connected to the gas tank 2 via the filling portion 31. The discharge portion 32 is a portion of the first flow path 12 that connects the combined valve mounting hole 27 and the gas tank 2. The discharge portion 32 opens to the inner circumferential surface of the combined valve mounting hole 27. The combined valve 15 is connected to the gas tank 2 via the discharge portion 32. The filling portion 31 and the discharge portion 32 may be flow paths independent of each other.

[0016] The second flow passage 13 includes a first portion 33, a second portion 34, a third portion 35, a fourth portion 36, and a joint flow passage 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 passage 37 is provided in the joint 22.

[0017] The first portion 33 opens to the inner end surface of the joint mounting hole 24. The first portion 33 extends linearly in the depth direction of the joint mounting hole 24. The first portion 33 connects the joint mounting hole 24 and the second portion 34.

[0018] The second portion 34 opens to the inner end surface of the manual valve mounting hole 25. The second portion 34 extends linearly in the depth direction of the manual valve mounting hole 25. The second portion 34 is perpendicular to the first portion 33. The inner diameter of the portion of the second portion 34 further back than the intersection with the first portion 33 is smaller than the inner diameter of the portion in front of the intersection. The back side is the side farther from the manual valve mounting hole 25. The front side is the side closer to the manual valve mounting hole 25.

[0019] The third portion 35 opens to the bottom surface of the integrated mounting hole 26. The third portion 35 extends linearly in the depth direction of the integrated mounting hole 26. The third portion 35 is perpendicular to the second portion 34. More specifically, the third portion 35 is perpendicular to the small diameter portion of the second portion 34. The third portion 35 communicates with the second portion 34 and the integrated mounting hole 26. However, the third portion 35 may be coaxial with the first portion 33. The third portion 35 may also be perpendicular to the large diameter portion of the second portion 34.

[0020] The fourth portion 36 opens to the bottom surface of the combined valve mounting hole 27. The fourth portion 36 extends linearly in the depth direction of the combined valve mounting hole 27. The fourth portion 36 is provided coaxially with the second portion 34. The fourth portion 36 communicates between the second portion 34 and the combined valve mounting hole 27. However, the fourth portion 36 may be provided perpendicular to the second portion 34.

[0021] The joint 22 is made of metal. The joint 22 is a cylindrical body with a circular cross section and has a joint flow path 37, which is a gas flow path. The joint flow path 37 extends linearly in the axial direction of the joint 22 and opens at both axial end faces of the joint 22. The joint 22 is fixed to the main body 21 by being screwed into the joint mounting hole 24. The joint flow path 37 communicates with the first portion 33.

[0022] The joint 22 is connected to the first pipe 6 or the second pipe 7. As a result, the second flow path 13 is connected to the supply source 4 or the consumer device 5 via the joint flow path 37. The excess flow valve 18 is provided inside the joint flow path 37. The joint 22 corresponds to a flow path forming member. The assembly of the joint 22 and the excess flow valve 18 corresponds to an excess flow valve device. The valve assembly 1 includes the excess flow valve device.

[0023] <Valve Subassembly> Next, the valve subassembly will be described. As shown in Fig. 1 , the manual valve 14 is fixed to the main body 21 by being screwed into the manual valve mounting hole 25. The manual valve 14 controls the flow of hydrogen gas between the first portion 33 and the second portion 34 of the second flow path 13. The manual valve 14 can be manually switched between a closed state and an open state. The closed state is a state in which the flow of hydrogen gas between the first portion 33 and the second portion 34 is blocked. The open state is a state in which the flow of hydrogen gas between the first portion 33 and the second portion 34 is permitted.

[0024] The safety valve 16 is fixed to the main body 21 by being screwed into the integrated mounting hole 26. The safety valve 16 prevents the pressure of the hydrogen gas in the gas tank 2 from reaching excessive pressure. The safety valve 16 switches between a closed state and an open state depending on the temperature of the safety valve 16. When the temperature of the safety valve 16 is equal to or lower than a threshold temperature, the safety valve 16 is maintained in the closed state. The closed state is a state in which hydrogen gas in the gas tank 2 is not released to the outside. When the temperature of the safety valve 16 exceeds the threshold temperature, the safety valve 16 irreversibly transitions from the closed state to an open state. The open state is a state in which hydrogen gas in the gas tank 2 is released to the outside.

[0025] The check valve 17 is fixed to the main body 21 by being screwed into the integrated mounting hole 26. The check valve 17 is disposed on the rear side of the integrated mounting hole 26 relative to the safety valve 16. The rear side is the side farther from the third side surface 21c of the main body 21. The check valve 17 prevents backflow of hydrogen gas filled in the gas tank 2. That is, the check valve 17 regulates the flow of hydrogen gas from the filling portion 31 of the first flow path 12 to the third portion 35 of the second flow path 13, while allowing hydrogen gas to flow from the third portion 35 to the filling portion 31. The check valve 17 controls the flow of hydrogen gas in a manner different from that of the safety valve 16.

[0026] The combined valve 15 is fixed to the main body 21 by being screwed into the combined valve mounting hole 27. The combined valve 15 has a solenoid valve portion that functions as a solenoid valve and a check valve portion that functions as a check valve. The combined valve 15 controls the flow of hydrogen gas between the release portion 32 of the first flow path 12 and the fourth portion 36 of the second flow path 13 by opening and closing the solenoid valve portion. The solenoid valve portion opens when energized, thereby allowing the flow of hydrogen gas between the release portion 32 and the fourth portion 36. The solenoid valve portion closes when energized, thereby blocking the flow of hydrogen gas between the release portion 32 and the fourth portion 36. The check valve portion allows the flow of hydrogen gas from the release portion 32 to the fourth portion 36 and restricts the flow of hydrogen gas from the fourth portion 36 to the release portion 32. This prevents high-pressure hydrogen gas from acting on the solenoid valve portion when hydrogen gas is being filled into the gas tank 2 from the supply source 4.

[0027] The excess flow valve 18 restricts the flow of hydrogen gas when the flow rate of hydrogen gas flowing in a specific direction through the joint flow path 37 of the second flow path 13 exceeds a predetermined flow rate. The predetermined direction is the direction of hydrogen gas from the gas tank 2 toward the consumer device 5. The excess flow valve 18 does not restrict the flow of hydrogen gas in the direction opposite to the predetermined direction. In other words, the excess flow valve 18 allows hydrogen gas to flow from the supply source 4 toward the gas tank 2. The predetermined flow rate is a threshold flow rate. Details of the excess flow valve 18 will be described later.

[0028] <Operation of Valve Assembly 1> Next, the operation of the valve assembly 1 will be described. When filling the gas tank 2 with hydrogen gas, the supply source 4 is connected to the fitting 22 via the first pipe 6. Hydrogen gas supplied from the supply source 4 flows into the check valve 17 via the fitting flow path 37, the first portion 33, the second portion 34, and the third portion 35 of the second flow path 13. The check valve 17 allows hydrogen gas to flow from the third portion 35 to the filling portion 31 of the first flow path 12. That is, the pressure of the hydrogen gas from the supply source 4 switches the check valve 17 from a closed state to an open state. Therefore, the hydrogen gas flowing into the check valve 17 fills the gas tank 2 via the filling portion 31. At this time, hydrogen gas also flows from the second portion 34 of the second flow path 13 to the check valve portion of the combined valve 15 via the fourth portion 36. However, the check valve portion restricts the flow of hydrogen gas from the fourth portion 36 to the release portion 32. Therefore, hydrogen gas does not flow from the second flow path 13 into the discharge portion 32 of the first flow path 12 .

[0029] When releasing hydrogen gas from the gas tank 2 to the consumer device 5, the consumer device 5 is connected to the joint 22 via the second pipe 7. Hydrogen gas in the gas tank 2 flows into the combined valve 15 via the release portion 32 of the first flow path 12. When the solenoid valve portion of the combined valve 15 switches from a closed state to an open state, the hydrogen gas flows into the check valve portion. The check valve portion allows hydrogen gas to flow from the release portion 32 to the fourth portion 36 of the second flow path 13. Therefore, the hydrogen gas flows into the second pipe 7 through the fourth portion 36, the second portion 34, the first portion 33, and the joint flow path 37 of the second flow path 13. The hydrogen gas flowing into the second pipe 7 is supplied to the consumer device 5. At this time, the hydrogen gas also flows into the check valve 17 from the second portion 34 through the third portion 35 of the second flow path 13. However, the check valve 17 is maintained in a closed state due to the pressure of hydrogen gas in the gas tank 2. Therefore, hydrogen gas does not flow from the third portion 35 into the filling portion 31 of the first flow path 12 .

[0030] In this way, the second flow path 13 is used as both a hydrogen gas filling path and a hydrogen gas supply path, that is, a part of the hydrogen gas filling path and a part of the hydrogen gas supply path are shared.

[0031] <Excessive Flow Valve Device> Next, the excessive flow valve device will be described in detail. As shown in FIG. 2 , the excessive flow valve device includes a fitting 22 and an excessive flow valve 18. The excessive flow valve 18 is provided in the fitting flow path 37 of the fitting 22. The excessive flow valve 18 includes a valve seat 41, a valve element 42, and a compression coil spring 43. The valve seat 41 is provided midway through the fitting flow path 37. The valve element 42 is movably housed in the fitting flow path 37. The compression coil spring 43 is a biasing member that biases the valve element 42 in a direction away from the valve seat 41. The excessive flow valve 18 also includes a stopper 44, a filter 45, a retaining member 46, and a sealing member 47. The stopper 44 defines one end of the movement range of the valve element 42 (the movement end in the valve opening direction).

[0032] The joint flow path 37 extends linearly in the axial direction of the joint 22. The joint flow path 37 has a circular cross-sectional shape. The joint flow path 37 has a stepped shape in which the inner diameter decreases in steps from the first end to the second end of the joint 22. The first end is the end of the joint 22 that is connected to the first portion 33 of the second flow path 13. The second end is the end of the joint 22 that is connected to the second pipe 7.

[0033] The joint flow path 37 has, in order from the first end side of the joint flow path 37, a seal member accommodating portion 51, a filter accommodating portion 52, a valve body accommodating portion 53, and a small diameter flow path portion 54. The inner diameters of the joint flow path 37 decrease in the order of the seal member accommodating portion 51, the filter accommodating portion 52, the valve body accommodating portion 53, and the small diameter flow path portion 54.

[0034] The inner circumferential surface of the valve body accommodating portion 53 has a locking groove 55. The locking groove 55 is disposed at a first end of the valve body accommodating portion 53. The first end is the end of the valve body accommodating portion 53 closer to the filter accommodating portion 52. The locking groove 55 is an annular groove provided around the entire periphery of the inner circumferential surface of the valve body accommodating portion 53.

[0035] A step 56 is provided in the joint 22 at the boundary between the valve element accommodating portion 53 and the small-diameter flow path portion 54. The step 56 is an annular flat surface that extends radially of the joint 22. The inner peripheral edge of the step 56 is used as a valve seat 41 on which the valve element 42 is seated. A first end of the small-diameter flow path portion 54 is used as a valve port 57. The first end is the end of the small-diameter flow path portion 54 on the valve element accommodating portion 53 side. The valve seat 41 is a part that is seamlessly continuous with other parts of the joint 22. In other words, the joint 22 is an integrated product that has the valve seat 41 together with the joint flow path 37. The inner peripheral edge of the step 56, i.e., the inner peripheral edge of the valve seat 41, may be chamfered in a tapered shape.

[0036] The filter 45 is, for example, a metallic mesh body having a circular cross section and is housed inside the filter housing portion 52. The filter 45 removes foreign matter contained in the hydrogen gas passing through the filter 45.

[0037] The pressing member 46 is made of, for example, metal and has a circular cross-sectional shape. The pressing member 46 is fitted inside the filter accommodating portion 52. The pressing member 46 presses the filter 45 against the inner end surface of the filter accommodating portion 52 in the axial direction. This fixes the filter 45 inside the filter accommodating portion 52.

[0038] The seal member 47 is made of, for example, rubber or resin. The seal member 47 is a cylindrical body having a circular cross-sectional shape. The seal member 47 is fitted into the seal member accommodating portion 51. When the fitting 22 is attached to the fitting mounting hole 24, the seal member 47 is compressed in the axial direction by the inner end surface of the seal member accommodating portion 51 and the inner end surface of the fitting mounting hole 24. The first end surface of the seal member 47 is maintained in axial contact with the inner end surface of the fitting mounting hole 24. The second end surface of the seal member 47 is maintained in axial contact with the inner end surface of the seal member accommodating portion 51. This ensures airtightness between the first end surface of the seal member 47 and the inner end surface of the fitting mounting hole 24, and between the second end surface of the seal member 47 and the inner end surface of the seal member accommodating portion 51. The outer peripheral surface of the seal member 47 may be in contact with the inner peripheral surface of the seal member accommodating portion 51 .

[0039] The valve element 42 is, for example, a metal columnar body having a circular cross-sectional shape. The axial direction of the valve element 42 is also the axial direction of the joint 22. The valve element 42 is housed inside the valve element housing portion 53. The valve element 42 is able to move axially inside the valve element housing portion 53. The valve element 42 moves between a valve open position and a valve closed position. The valve open position is a position of the valve element 42 where the valve element 42 is separated from the valve seat 41 in the axial direction. The valve closed position is a position of the valve element 42 where the valve element 42 is seated on the valve seat 41 and where the valve element 42 closes the valve port 57.

[0040] The compression coil spring 43 is interposed between the valve body 42 and the stepped portion 56. The compression coil spring 43 is maintained in an axially compressed state by the valve body 42 and the stepped portion 56. That is, the compression coil spring 43 constantly biases the valve body 42 in the valve-opening direction. The valve-opening direction is the direction from the second end toward the first end of the joint 22, that is, the direction in which the valve body 42 moves away from the valve seat 41.

[0041] The stopper 44 is a metal annular member. The stopper 44 is, for example, a snap ring. The snap ring has a C-shape with a notch cut out in part of the ring. The outer periphery of the stopper 44 fits into the locking groove 5. The stopper 44 restricts movement of the valve body 42 in the valve opening direction. The movement of the valve body 42 in the valve opening direction is restricted when a first end of the valve body 42 abuts against the stopper 44 in the axial direction. The first end is the end of the valve body 42 on the stopper 44 side.

[0042] The valve element 42 is subjected to a differential pressure biasing force. The differential pressure biasing force is a force corresponding to the pressure difference between the upstream pressure and the downstream pressure acting on the valve element 42. The valve element 42 moves axially inside the valve element accommodating portion 53 in response to the differential pressure biasing force and the elastic force of the compression coil spring 43. The elastic force of the compression coil spring 43 is a mechanical biasing force exerted by the compression coil spring 43. The moving direction of the valve element 42 coincides with the axial direction of the joint 22.

[0043] The excess flow valve 18 is a so-called normally open valve. That is, the valve element 42 is basically maintained away from the valve seat 41, i.e., in the open position. When filling the gas tank 2 with hydrogen gas, the first end of the joint flow path 37 is downstream, and the second end of the joint flow path 37 is upstream. Therefore, the valve element 42 is urged in a direction away from the valve seat 41 by both the differential pressure biasing force and the elastic force of the compression coil spring 43. Movement of the valve element 42 in the valve opening direction is restricted by the first end of the valve element 42 abutting against a stopper 44 in the axial direction. This maintains the valve element 42 away from the valve seat 41. The excess flow valve 18 is maintained in an open state.

[0044] When releasing hydrogen gas to the consumer device 5, the first end of the joint flow path 37 is the upstream side, and the second end of the joint flow path 37 is the downstream side. The elastic force of the compression coil spring 43 is set to be greater than the differential pressure biasing force corresponding to the pressure difference, provided that there is no abnormality in the second piping 7 connected to the excess flow valve 18 and the pressure difference between the upstream and downstream sides of the valve body 42 is within a set range. Therefore, the elastic force of the compression coil spring 43 keeps the valve body 42 separated from the valve seat 41. The excess flow valve 18 is maintained in an open state.

[0045] In contrast, if the downstream pressure on the valve element 42 suddenly drops due to damage to the second pipe 7, for example, the pressure difference between the upstream and downstream sides of the valve element 42 becomes excessive. As a result, the differential pressure biasing force corresponding to the pressure difference between the upstream and downstream sides becomes greater than the elastic force of the compression coil spring 43. As a result, the valve element 42 moves toward the second end of the joint flow path 37 against the elastic force of the compression coil spring 43 and seats on the valve seat 41. In other words, the excess flow valve 18 is closed.

[0046] <Configuration of Valve Body 42> Next, a detailed description will be given of the configuration of the valve body 42. As shown in Figures 2, 3, and 4, the valve body 42 has, in order from the second end side of the joint flow path 37, a valve portion 61, a base portion 62, and a cylindrical portion 63.

[0047] The valve portion 61 is a cylindrical body with a circular cross-sectional shape. The shape of the valve body 61 is, for example, a truncated cone shape. The outer diameter of the valve portion 61 decreases toward the second end of the joint flow path 37. The minimum diameter of the valve portion 61 is smaller than the inner diameter of the small-diameter flow path portion 54, i.e., the inner diameter of the valve port 57. The maximum diameter of the valve portion 61 is larger than the inner diameter of the small-diameter flow path portion 54, i.e., the inner diameter of the valve port 57. Therefore, by seating the valve portion 61 on the valve seat 41, it is possible to close the valve port 57. When the valve portion 61 is seated on the valve seat 41, the tip of the valve portion 61 is inserted into the valve port 57.

[0048] The base 62 is a cylindrical body with a circular cross-sectional shape. The base 62 is arranged coaxially with the valve portion 61. The base 62 has a receiving portion 64. The receiving portion 64 is a portion of the base 62 that supports the coil spring 43. The receiving portion 64 has a smaller diameter than the rest of the base 62 and faces the second end of the joint flow path 37. The end of the coil spring 43 is attached to the outer periphery of the receiving portion 64. The outer diameter of the receiving portion 64 is larger than the maximum diameter of the valve portion 61. The outer diameter of the large-diameter portion of the base 62 is larger than the outer diameter of the receiving portion 64 and slightly smaller than the inner diameter of the valve body accommodating portion 53. The outer diameter of the large-diameter portion of the base 62 is the maximum diameter of the base 62.

[0049] The base 62 has a plurality of valve element flow paths 65. The number of valve element flow paths 65 is, for example, four. The plurality of valve element flow paths 65 are arranged at equal angular intervals in the circumferential direction of the base 62. The valve element flow paths 65 penetrate the base 62 in the axial direction. The shape of the valve element flow paths 65 is, for example, fan-shaped when viewed in the axial direction of the valve element 42. When viewed in the axial direction of the valve element 42, the valve element flow paths 65 are arranged between the valve portion 61 and the receiving portion 64 in the radial direction of the valve element 42.

[0050] The total cross-sectional area of ​​the multiple valve element flow paths 65 is larger than the cross-sectional area of ​​the small-diameter flow path portion 54. Each of the multiple valve element flow paths 65 has, for example, the same cross-sectional area. However, each of the multiple valve element flow paths 65 may have a different cross-sectional area. Furthermore, the cross-sectional area of ​​each of the multiple valve element flow paths 65 may be larger or smaller than the cross-sectional area of ​​the small-diameter flow path portion 54.

[0051] The cylindrical portion 63 is a cylindrical body having a circular cross-sectional shape. The cylindrical portion 63 is arranged coaxially with the base portion 62. The outer diameter of the cylindrical portion 63 is equal to the outer diameter of the large-diameter portion of the base portion 62. The outer peripheral surface of the cylindrical portion 63 is continuous with the outer peripheral surface of the large-diameter portion of the base portion 62 without any steps. In other words, the outer peripheral surfaces of the cylindrical portion 63 and the large-diameter portion of the base portion 62 form a single cylindrical surface. The outer diameter of the cylindrical surface is slightly smaller than the inner diameter of the valve element accommodating portion 53. Therefore, the valve element 42 is movable axially and radially within the valve element accommodating portion 53.

[0052] The valve element 42 has a pore 66. The pore 66 penetrates the valve portion 61 and the base portion 62 in the axial direction of the valve element 42. The interior of the pore 66 is in communication with the interior of the tubular portion 63. Therefore, even when the valve element 42 is seated on the valve seat 41, hydrogen gas can pass through the excess flow valve 18. However, the cross-sectional area of ​​the pore 66 is narrower than the flow path cross-sectional area of ​​the small-diameter flow path portion 54. The flow path cross-sectional area of ​​the pore 66 is also narrower than the cross-sectional area of ​​each of the valve element flow paths 65. Therefore, the flow rate of hydrogen gas when the excess flow valve 18 is closed is less than the flow rate of hydrogen gas when the excess flow valve 18 is open.

[0053] <Flow of Hydrogen Gas> Next, the flow of hydrogen gas passing through the excess flow valve 18 will be described. As shown in FIG. 5 , when hydrogen gas is being filled into the gas tank 2, the excess flow valve 18 is kept open by the elastic force of the compression coil spring 43. At this time, hydrogen gas from the supply source 4 flows through the joint flow path 37 in a direction from the second end of the joint 22 to the first end. As shown by the arrows in FIG. 5 , the hydrogen gas flows from the small-diameter flow path portion 54 into the valve body accommodating portion 53. The hydrogen gas flowing into the valve body accommodating portion 53 mainly flows through the valve body flow path 65 into the first portion 33 of the second flow path 13. Furthermore, a portion of the hydrogen gas flowing into the valve body accommodating portion 53 flows into the first portion 33 of the second flow path 13 through the gap between the outer circumferential surface of the valve body 42 and the inner circumferential surface of the valve body accommodating portion 53. A small amount of hydrogen gas flows into the first portion 33 of the second flow path 13 through the pore 66. The gap will be described in detail later.

[0054] When hydrogen gas is released from the gas tank 2, the excess flow valve 18 is kept open by the elastic force of the compression coil spring 43. At this time, hydrogen gas from the gas tank 2 flows through the fitting flow path 37 in a direction from the first end to the second end of the fitting 22. The hydrogen gas passes through the seal member accommodating portion 51 and the filter accommodating portion 52 and flows into the valve body accommodating portion 53. The hydrogen gas flowing into the valve body accommodating portion 53 mainly flows into the small diameter flow path portion 54 through the valve body flow path 65. Furthermore, a portion of the hydrogen gas flowing into the valve body accommodating portion 53 flows into the small diameter flow path portion 54 through the gap between the outer peripheral surface of the valve body 42 and the inner peripheral surface of the valve body accommodating portion 53. A small amount of hydrogen gas flows into the small diameter flow path portion 54 through the pores 66.

[0055] When releasing hydrogen gas from the gas tank 2, if the pressure downstream of the valve element 42 suddenly drops due to, for example, an abnormality in the second pipe 7 or the check valve 17, the excess flow valve 18 switches from an open state to a closed state against the elastic force of the compression coil spring 43. An abnormality in the second pipe 7 may be, for example, damage to the second pipe. Damage includes rupture of the second pipe. An abnormality in the check valve 17 may be, for example, the check valve 17 being stuck in the open position. At this time, a small amount of hydrogen gas flows through the pores 66 into the small-diameter flow passage portion 54. Because the valve element flow passage 65 is located on the outer periphery of the valve portion 61, hydrogen gas does not flow through the valve element flow passage 65 into the small-diameter flow passage portion 54. This prevents a sudden release of hydrogen gas from the gas tank 2. Furthermore, releasing a small amount of hydrogen gas can alert the user to the occurrence of an abnormality.

[0056] <Behavior of Valve Disk 42> Next, the behavior of the valve disk 42 when filling the gas tank 2 with hydrogen gas will be described. When filling the gas tank 2 with hydrogen gas, hydrogen gas from the supply source 4 flows through the joint flow path 37 in a direction from the second end to the first end of the joint 22. The direction from the second end to the first end of the joint 22 is opposite to the direction of hydrogen gas flow from the gas tank 2 to the consumer device 5. The action of hydrogen gas passing through the joint flow path 37, particularly the notch 44A of the stopper 44, causes an uneven pressure distribution around the valve disk 42 in the circumferential direction of the valve disk 42. As a result, a radial force acts on the valve disk 42, pressing the valve disk 42 against the inner circumferential surface of the valve disk accommodating portion 53. This suppresses vibration of the valve disk 42.

[0057] The phenomenon in which the valve element 42 becomes eccentric due to a bias in the pressure distribution around the valve element 42 and the valve element 42 is pressed strongly against the inner circumferential surface of the valve element accommodating portion 53 is called hydraulic lock. In this embodiment, the hydraulic lock phenomenon is intentionally caused to occur.

[0058] <Configuration for Generating Hydraulic Lock Phenomenon> In this embodiment, the following configuration is adopted for the excess flow valve 18 in order to generate the hydraulic lock phenomenon.

[0059] As shown in FIG. 6 , the stopper 44 is an asymmetric member. The stopper 44 is symmetric with respect to a first axis of symmetry perpendicular to the axial direction of the stopper 44 and asymmetric with respect to a second axis of symmetry perpendicular to the axial direction of the stopper 44. The first and second axes of symmetry are perpendicular to each other. The stopper 44 has, for example, a C-shape with a notch 44A in a portion of the annular ring. Both ends of the stopper 44 in the circumferential direction have protrusions 44B. The protrusions 44B protrude radially inward from the stopper 44. Therefore, when viewed from the axial direction of the valve body 42, a portion of the protrusions 44B may overlap the valve body flow paths 65. In the example of FIG. 5 , the protrusions 44B overlap one of the four valve body flow paths 65.

[0060] The flow rate of hydrogen gas flowing through the valve element flow path 65 where the protrusion 44B overlaps is smaller than the flow rate of hydrogen gas flowing through the valve element flow path 65 where the protrusion 44B does not overlap. This is because the cross-sectional area of ​​the valve element flow path 65 where the protrusion 44B overlaps is narrower than the cross-sectional area of ​​the valve element flow path 65 where the protrusion 44B does not overlap by the amount of the overlapping protrusion 44B.

[0061] Furthermore, for example, when the flow rate of hydrogen gas flowing into the joint flow path 37 is the same, the flow rate of hydrogen gas passing through the valve element flow path 65 is determined by the cross-sectional area of ​​the valve element flow path 65. The narrower the cross-sectional area, the faster the flow rate. Therefore, the flow rate of hydrogen gas passing through the valve element flow path 65 where the protrusions 44B overlap is faster than the flow rate of hydrogen gas passing through the valve element flow path 65 where the protrusions 44B do not overlap. Due to the difference in the flow rate of hydrogen gas passing through the four valve element flow paths 65, a pressure distribution that is biased in the circumferential direction of the valve element 42 occurs around the valve element 42.

[0062] First of all, by installing the stopper 44, which is an asymmetric member, inside the joint flow path 37, the shape of the hydrogen gas flow path becomes asymmetric when viewed from the axial direction of the valve body 42. Therefore, the action of the hydrogen gas passing through the cutout 44A causes a difference in the flow rate of the hydrogen gas passing through the joint flow path 37. As a result, a pressure distribution that is biased in the circumferential direction of the valve body 42 occurs around the valve body 42.

[0063] 2 , in order to generate an uneven pressure distribution around the valve disc 42 in the circumferential direction of the valve disc 42, it is also necessary to provide a gap δ sufficient for hydrogen gas to flow between the outer peripheral surface of the valve disc 42 and the inner peripheral surface of the valve disc accommodating portion 53. The gap δ is, for example, the gap between the outer peripheral surface of the large diameter portion of the valve disc 42 and the inner peripheral surface of the valve disc accommodating portion 53 when the valve disc 42 is positioned coaxially with the valve disc accommodating portion 53.

[0064] The gap δ is set larger than normal. "Normal" refers to a case where the gap δ is set strictly small, for example, to suppress tilt of the valve body 42. As shown in the following equations (1) and (2), the first gap δ1, which is the gap δ in this embodiment, is set to a value approximately 10 times larger than the second gap δ, which is the normal gap δ.

[0065] δ1 = 400 μm (1) δ2 = 40 μm (2) When the gap δ is the normal second gap δ2, the flow rate of hydrogen gas flowing around the valve disc 42 is small. Therefore, a force acting in the radial direction of the valve disc 42 is unlikely to be generated. Therefore, hydraulic lock is unlikely to occur. In contrast, when the gap δ is the first gap δ1, a sufficient flow rate of hydrogen gas flowing around the valve disc 42 is ensured. Therefore, a sufficient force acting in the radial direction of the valve disc 42 is likely to be generated. Therefore, hydraulic lock is likely to occur. However, the gap δ is set to a size that allows the valve disc 42 to be pressed against the inner circumferential surface of the valve disc accommodating portion 53 when a radial force acts on the valve disc 42 due to an imbalance in the pressure distribution around the valve disc 42.

[0066] The hydraulic lock phenomenon occurs due to the action of hydrogen gas passing through the notch 44A, regardless of the radial position of the valve body 42 relative to the stopper 44. For example, consider a case where hydrogen gas from the supply source 4 flows into the joint flow path 37 when the valve body 42 is in the first to third initial positions P1 to P3.

[0067] As shown in Fig. 7, the first initial position P1 is a position of the valve disc 42 where the valve disc 42 is arranged coaxially with the stopper 44, as viewed in the axial direction of the valve disc 42. As shown in Fig. 8, the second initial position P2 is a position of the valve disc 42 where the valve disc is eccentric to the 6 o'clock position, as viewed in the axial direction of the valve disc 42.

[0068] As shown in Figure 9, the third initial position P3 is a position of the valve disc 42 where the valve disc is eccentric to the 3 o'clock position when viewed in the axial direction of the valve disc 42. As shown in Figure 10, regardless of which of the first to third initial positions P1 to P3 the valve disc 42 is in, when hydrogen gas from the supply source 4 flows into the joint flow path 37, a hydraulic lock phenomenon occurs. When viewed in the axial direction of the valve disc 42, the valve disc 42 is eccentric to, for example, the 12 o'clock position and pressed against the inner circumferential surface of the valve disc accommodating portion 53. The 12 o'clock position is, for example, a position radially opposite the notch 44A of the stopper 44 when viewed in the axial direction of the valve disc 42. The 12 o'clock position is an example of a specific radial position P0 within the valve disc accommodating portion 53 where the valve disc 42 is fixed.

[0069] <Effects of this embodiment> This embodiment provides the following effects. (1) The notch 44A is configured to cause a bias in the pressure distribution around the valve element 42 due to the action of the hydrogen gas passing through the notch 44A when the hydrogen gas flows through the gap δ between the outer peripheral surface of the valve element 42 and the inner peripheral surface of the valve element accommodating portion 53 in a direction opposite to the specific direction. The specific direction is the direction in which the hydrogen gas is released to the consumer device 5. The direction opposite to the specific direction is the flow direction of hydrogen gas from the supply source 4 toward the gas tank 2 when the gas tank 2 is filled with hydrogen gas. Furthermore, the gap δ between the outer peripheral surface of the valve element 42 and the inner peripheral surface of the valve element accommodating portion 53 is set to a size such that when a radial force acts on the valve element 42 due to a bias in the pressure distribution around the valve element 42, the valve element 42 is pressed against the inner peripheral surface of the valve element accommodating portion 53.

[0070] Therefore, when hydrogen gas flows through the gap δ between the outer peripheral surface of the valve element 42 and the inner peripheral surface of the valve element accommodating portion 53 in a direction opposite to the specific direction, the valve element 42 is pressed against the inner peripheral surface of the valve element accommodating portion 53. This fixes the valve element 42 at a specific radial position P0 within the valve element accommodating portion 53. This suppresses vibration of the valve element 42. It also reduces pressure pulsation caused by vibration of the valve element 42. This also improves noise and vibration (NV) performance. It is also possible to shorten the time it takes to fill the gas tank 2 with hydrogen gas.

[0071] (2) A stopper 44 is disposed downstream of the valve body 42. The downstream side is the side through which hydrogen gas flows when the gas tank 2 is filled with hydrogen gas. Because the stopper 44 has the notch 44A, the shape of the stopper 44 is asymmetric when viewed in the axial direction of the stopper 44. By attaching the stopper 44 inside the joint flow path 37, the shape of the hydrogen gas flow path becomes asymmetric when viewed in the axial direction of the valve body 42. Therefore, when hydrogen gas flows through the gap δ between the outer circumferential surface of the valve body 42 and the inner circumferential surface of the valve body accommodating portion 53 in a direction opposite to the specific direction, a difference in the flow rate of the hydrogen gas can be generated.

[0072] (2) The valve element 42 moves in the valve closing direction only when the check valve 17 is stuck in the open position and the second pipe 7 is damaged. This prevents uneven wear of the valve element 42. <Other Embodiments> This embodiment may be modified as follows.

[0073] The stopper 44 may have a configuration in which the protrusion 44B is omitted. The stopper 44 may have the notch 44A. Although the coil spring 43 is used as the biasing member, this is not limiting, and for example, a disc spring or the like may be used as the biasing member.

[0074] The following configuration may be adopted instead of the pore 66 of the valve body 42. For example, a groove may be formed on at least one of the outer circumferential surface of the valve portion 61 of the valve body 42 and the inner circumferential surface of the valve port 57. Even in this case, a small amount of hydrogen gas is released even when the excess flow valve 18 is closed.

[0075] The valve element 42 may be configured without the fine hole 66. In this case, hydrogen gas is not released when the excess flow valve 18 is closed. The total cross-sectional area of ​​the valve element flow path 65 may be smaller than the cross-sectional area of ​​the small-diameter flow path portion 54.

[0076] The shape of the valve element flow path 65 may be a shape other than a sector, such as a circle, when viewed in the axial direction of the valve element 42. The number of valve element flow paths 65 may be changed as appropriate. The number of valve element flow paths 65 may be one.

[0077] The valve body 42 may be configured without the cylindrical portion 63. The excess flow valve 18 may be configured without the pressing member 46. In this case, the filter 45 may be pressed down by the sealing member 47, for example.

[0078] The excess flow valve 18 may be configured without the filter 45. Alternatively, the excess flow valve 18 may be configured without both the filter 45 and the seal member 47.

[0079] The valve seat 41 may be a separate member from the joint 22. The valve seat 41 is attached to the inside of the joint flow path 37. The excess flow valve 18 may be incorporated into the main body 21 instead of the joint 22.

[0080] The excess flow valve device may be used independently of the valve assembly 1. In this case, the flow path forming member that forms the gas flow path may be a member other than the joint 22. The valve assembly 1 controls the flow of high-pressure hydrogen gas, but is not limited to this and may control the flow of gases other than hydrogen gas.

[0081] In this specification, "annular" means that the entire structure can be considered to be annular, and includes a structure formed by combining multiple parts or portions into an annular shape, or a structure having a cutout such as a C-shape. "Annular" shapes include, but are not limited to, circular, elliptical, and polygonal shapes with sharp or rounded corners when viewed in the axial direction. "Cylindrical" means that the entire structure can be considered to be annular, and includes a structure formed by combining multiple parts or portions into an annular shape, or a structure having a cutout such as a C-shape when viewed in the axial direction. "Cylindrical" shapes include, but are not limited to, circular, elliptical, and polygonal shapes with sharp or rounded corners when viewed in the axial direction.

Claims

1. An excess flow valve device comprising: a flow path forming member having a gas flow path; and an excess flow valve configured to restrict the flow of gas when the flow rate of gas flowing through the gas flow path in a specific direction exceeds a predetermined flow rate, wherein the gas flow path has a valve body accommodating portion that accommodates the excess flow valve, and the excess flow valve comprises: a valve seat provided in the valve body accommodating portion, the valve seat having a valve opening; a valve body movably accommodated in the valve body accommodating portion; a biasing member configured to bias the valve body in a direction away from the valve seat; and a stopper configured to define one end of the movement range of the valve body, wherein the valve body has a valve portion configured to close the valve opening by seating on the valve seat; a receiving portion configured to support the biasing member; and a valve body flow path that penetrates the valve body in the movement direction of the valve body, and is positioned between the valve portion and the receiving portion in a direction perpendicular to the movement direction, and the stopper is an annular member having a notch in part of the ring, and is attached inside the valve body accommodating portion so that gas passes through the notch, the notch is configured to cause a bias in the pressure distribution around the valve body by the action of the gas passing through the notch when the gas flows through the gap between the outer peripheral surface of the valve body and the inner peripheral surface of the valve body accommodating portion in a direction opposite to the specific direction, and the gap between the outer peripheral surface of the valve body and the inner peripheral surface of the valve body accommodating portion is set to a size that allows the valve body to be pressed against the inner peripheral surface of the valve body accommodating portion when a radial force acts on the valve body due to the bias in the pressure distribution around the valve body.

2. A valve assembly comprising: a body having a gas flow path including a first flow path and a second flow path; and an excess flow valve configured to restrict the flow of gas when the flow rate of gas flowing in a specific direction through the second flow path exceeds a predetermined flow rate, wherein the first flow path is configured to be connected to a gas tank that stores gas, and the second flow path is configured to be selectively connected to any one of a plurality of external devices, wherein the plurality of external devices include a gas supply source for filling the gas tank and a consumer device that consumes gas released from the gas tank, and the second flow path has a valve body accommodating portion that accommodates the excess flow valve, and the specific direction is the direction in which gas is released to the consumer device, and the excess flow valve comprises: a valve seat provided in the valve body accommodating portion, the valve seat having a valve opening; a valve body movably accommodated in the valve body accommodating portion; an urging member configured to urge the valve body in a direction away from the valve seat; and a stopper configured to define one end of a movement range of the valve body, a valve portion configured to close the valve orifice by being seated on the valve seat; a receiving portion configured to support the biasing member; and a valve element flow path that penetrates the valve element in the movement direction of the valve element, the valve element flow path being positioned between the valve portion and the receiving portion in a direction perpendicular to the movement direction, wherein the stopper is an annular member having a notch in part of the ring, and is attached to the inside of the valve element accommodating portion so that gas passes through the notch, and the notch is configured to cause a bias in the pressure distribution around the valve element by the action of the gas passing through the notch when the gas flows through a gap between the outer circumferential surface of the valve element and the inner circumferential surface of the valve element accommodating portion in a direction opposite to the specific direction, and the gap between the outer circumferential surface of the valve element and the inner circumferential surface of the valve element accommodating portion is set to a size such that the valve element is pressed against the inner circumferential surface of the valve element accommodating portion when a radial force acts on the valve element due to the bias in the pressure distribution around the valve element.

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