JP2024040311A - Overflow prevention valve - Google Patents

Abstract

[Problem] To provide an overflow prevention valve that closes the valve while avoiding malfunction, prevents excess fluid over the normal flow rate from flowing to the secondary side, maintains sufficient sealing performance even when the temperature of the fluid changes, and reliably prevents external leakage, and has a simple internal structure that makes it easy to manufacture. [Solution] A tubular body member 1 and a cap member 2 are joined to form a main body 10 with a fluid flow path 11 inside. A storage space S is formed near the opposing surfaces of the main body, and first and second valve bodies 5, 6, which are resiliently biased in the valve opening direction by a spring member 4, are attached to the first and second sides of the holder member so that the valve can be closed by fluid pressure. The storage space is formed by an annular step 21 with an enlarged diameter on either or both of the opposing surfaces of the cap member and the body member, and the holder member is fitted into the annular step for positioning. The first and second valve bodies are attached to the holder member in series on the first and secondary sides, respectively, and the secondary side of the second valve body is loosely fitted into an attachment portion 14 formed on the primary side of the fluid flow path. [Selected Figure] Figure 1

Description

The present invention prevents excessive fluid from flowing to the secondary side by blocking the flow path when the flow rate attempts to exceed the normal flow rate due to damage to equipment etc. connected to the secondary side. Regarding overflow prevention valve.

For example, in the hydrogen supply piping equipment of a hydrogen station for automobile fuel cells, many devices are connected through valves and piping, such as manual valves and automatic valves, and after passing through these, high-pressure hydrogen is sent to the discharge side for filling. It is supplied from the nozzle to the car's on-board tank. In such equipment where high-pressure hydrogen (high-pressure fluid) flows, even if a small portion of equipment, valves, piping, etc. is damaged or malfunctions, there is a risk of excessive high-pressure fluid leaking from the secondary side. For this reason, in order to prevent excess fluid from flowing out to the secondary side beyond normal use, an overflow prevention valve that shuts off fluid is generally connected within the flow path.

As this type of overflow prevention valve, for example, an overflow prevention valve disclosed in Patent Document 1 is disclosed. In this overflow prevention valve, a second tubular member is joined by screwing to a first tubular member having a valve chamber, and a single valve body is movably mounted in the valve chamber along the flow path direction. There is. This type of overflow prevention valve is formed into a substantially tubular shape and is connected in series with the flow path, and under normal conditions, the valve remains open and the normal flow rate flows, but on the other hand, if the flow rate decreases due to damage to equipment or piping. When the flow rate becomes extremely larger than the normal flow rate, the valve body moves to the secondary side and closes the valve, cutting off the flow path. This valve has a so-called one-stage structure in which a single valve element is mounted within the main body, and the flow path is closed by the operation of this single-stage valve element.

On the other hand, as shown in FIG. 6(a), there is also known an overflow prevention valve 100 having a so-called two-stage structure in which two valve bodies are mounted within the main body. This overflow prevention valve 100 includes a tubular body 101 and a cap 102, and a cylindrical portion 103 is formed on the front side of the cap 102, and an enlarged diameter cylindrical portion 104 whose diameter is larger than that of the cylindrical portion 103 is formed on the rear side. A male threaded portion 105 is provided on the outer periphery of this enlarged diameter cylindrical portion 104 . A sealing O-ring 106 is attached to the outer periphery of the cylindrical portion 103 near the boundary with the enlarged-diameter cylindrical portion 104 . On the other hand, the body 101 is formed with an insertion hole 110 into which the cylindrical part 103 is inserted, and a mounting recess 111 into which the enlarged diameter cylindrical part 104 is mounted. A female screw portion 112 is provided to which the screw is screwed.

The cap 102 is attached to the body 101 by screwing the male threaded portion 105 and the female threaded portion 112 together, and after the attachment, the cylindrical portion 103 is inserted into the insertion hole 110 and these are sealed with an O-ring 106. The distal end surface 104a on the distal end side of the enlarged diameter cylindrical portion 104 contacts the bottom surface 111a of the mounting recess 111 and is positioned and fixed to the body 101. A cylindrical holder 120 is accommodated in the insertion hole 110 on the forward side of the cylindrical portion 103, and this holder 120 is positioned between the cylindrical portion tip end surface 103a and the abutment surface 110a of the insertion hole 110. It is fixed at A first poppet valve body 121 is attached to the primary side of the holder 120, and a second poppet valve body 121 is attached to the secondary side of the holder 120. As shown in FIG. The poppet valve bodies 122 are each provided so as to be movable in the valve closing direction against the elastic force of a spring 123 mounted therein.
An annular elastic member 124 is attached to the distal end side of the cylindrical portion 103, and the elastic member 124 is pressed against the holder 120 when the cap 102 is screwed in.

Japanese Patent Application Publication No. 2010-266000

The former excessive flow prevention valve of Patent Document 1 has a one-stage valve body structure, so when the pressure of the fluid flowing through the piping equipment to which this valve is connected suddenly increases (for example, immediately after turning on the power, etc.) ), even though there is no excessive outflow beyond normal use, the rapid flow may cause one valve body to move in the closing direction and cause a malfunction, and this malfunction may close the flow path. .

On the other hand, the latter overflow prevention valve 100 shown in FIG. 6 is provided with poppet valve bodies 121 and 122 of a two-stage structure, so that the first poppet valve body 121 in the first stage may malfunction due to a sudden pressure increase, causing the valve to open. Even if the valve is closed, a small amount of fluid continues to flow to the second poppet valve body 122 of the second stage when the valve is closed, which prevents sudden overflow prevention valves like the one-stage overflow prevention valve of Patent Document 1. It is now possible to avoid blockage of the flow path.
However, this excessive flow prevention valve 100 has a configuration in which the enlarged diameter cylindrical portion 104 is screwed into the mounting recess 111 and the outer periphery of the cylindrical portion 103 and the inner periphery of the insertion hole portion 110 are sealed in the circumferential direction by the O-ring 106. Therefore, for example, when the O-ring 106 expands or contracts due to a change in the temperature of the fluid, the sealing performance decreases. In particular, when low-temperature high-pressure fluid flows, the O-ring 106 may contract and cause external leakage. be.

In addition, the cap 102 is positioned and fixed to the body 101 by bringing the distal end surface 104a of the enlarged diameter cylindrical portion 104 into contact with the bottom surface 111a of the mounting recess 111, thereby creating a space C in which the holder 120 of the insertion hole portion 110 is accommodated. Because of this setting, the length of this space C in the flow path direction is constant. Therefore, if the elastic member 124 that is pressed between the holder 120 and the cylindrical portion distal end surface 103a deteriorates over time, or becomes short in the flow path direction due to shrinkage or damage, the cap 102 and the holder 120, resulting in insufficient fixation of the holder 120.

As mentioned above, since the space C of the holder 120 is set by the contact between the distal end surface 104a of the enlarged diameter cylindrical portion and the bottom surface 111a of the mounting recess, precise dimensional accuracy is required during manufacturing, and the internal structure is also complicated. It also has the problem of being difficult to process.

The present invention was developed to solve the conventional problems, and its purpose is to close the valve and prevent excess fluid above the normal flow rate from flowing out to the secondary side while avoiding malfunction. To provide an overflow prevention valve that prevents leakage from the outside by maintaining sufficient sealing performance even when a temperature change occurs in a fluid, and that is easy to manufacture due to a simple internal configuration.

In order to achieve the above object, the invention according to claim 1 is such that a tubular body member and a cap member are joined to form a body body having a fluid flow path therein, and a body body having a fluid flow path therein is configured. An accommodation space is formed that communicates with the fluid flow path and accommodates a cylindrical holder member, and the first and second sides of the holder member accommodated in this accommodation space are each elasticized in the valve opening direction by spring members. The energized first valve element and second valve element are installed in a state where the valve can be closed by fluid pressure, and the housing space is configured to allow fluid flow to either or both of the facing surfaces of the cap member and the body member. The outer periphery of the holder member is fitted into the annular step portion for positioning, and the first valve body and the second valve body are installed in series on the primary side and the secondary side, respectively, and the second valve body is loosely fitted into the installation part formed on the primary side of the fluid flow path. It is.

The invention according to claim 2 is an overflow prevention valve in which a long cylindrical portion is formed on the secondary side of the second valve body, and this long cylindrical portion is formed in an outer shape that can be inserted into the mounting portion.

The invention according to claim 3 is an overflow prevention valve, wherein the mounting portion is formed in a secondary flow path forming a secondary side of the fluid flow path, with the diameter slightly expanding toward the primary side. .

According to the first aspect of the invention, an annular stepped portion is formed on the opposing surfaces of the cap member and the body member, and the outer periphery of the holder member is fitted into the annular stepped portion for positioning. The body member and the cap member can be easily integrated in a state in which the first valve body, the second valve body, and the spring member are temporarily assembled.
Furthermore, since the annular stepped portion is provided to form a housing space, and the holder member is fixed in this housing space by clamping, the space for mounting the holder member can be minimized. , it is possible to simplify the structure and make it more compact.
A mounting portion is formed in the secondary flow path provided on the inner peripheral side of the body member, and a second valve body is loosely fitted between the holder member and the mounting portion of the body member within the secondary flow path. In this state, when fluid pressure is applied from the first valve body side, the second valve body can be brought into the valve closed state.

According to the invention set forth in claim 2, by inserting the elongated cylindrical part on the secondary side of the second valve element into the mounting part, the second valve element can be mounted in the holder in the secondary side flow path of the body member. It can be placed between the member and the mounting portion of the body member.

According to the invention set forth in claim 3, the second valve body can be attached to the secondary flow path formed in the body member, and the second valve body can be abutted and sealed on the valve seat formed in the secondary flow path. The valve can be closed by closing the valve.

1 is a sectional view showing an embodiment of an overflow prevention valve of the present invention. FIG. 2 is an isolated perspective view of the overflow prevention valve of FIG. 1; FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1. FIG. FIG. 4 is an enlarged sectional view of a main part of the first valve body in FIG. 3 in a closed state. FIG. 4 is an enlarged cross-sectional view of a main part showing the first valve body and the second valve body of FIG. 3 in a closed state. FIG. 2 is a sectional view showing a conventional overflow prevention valve.

EMBODIMENT OF THE INVENTION Below, embodiment of the overflow prevention valve in this invention is described in detail based on drawing. The overflow prevention valve of the present invention is particularly suitable as an overflow prevention valve used in hydrogen supply piping equipment at a hydrogen station. FIG. 1 shows an embodiment of the overflow prevention valve of the present invention, and shows the valve in an open state. 2 is an exploded perspective view of the overflow prevention valve of FIG. 1, and FIG. 3 is an enlarged cross-sectional view of the essential parts of the overflow prevention valve of FIG. 1 in an open state.

In the figure, the overflow prevention valve includes a body member 1, a cap member 2, a cylindrical holder member 3, a spring member 4 consisting of a coil spring, a first valve body 5, a second valve body 6, a buffer member 7, and a seal member. It is equipped with a gasket 8 and is configured by combining these, and maintains the valve open state at normal flow rate, and closes the valve when the flow rate exceeds normal flow rate to prevent excessive flow to the secondary side. do. In addition, in the overflow prevention valve of FIG. 1, the left side is the primary side, and the right side is the secondary side.

The body member 1 and the cap member 2 are formed in a tubular shape, for example, from stainless steel or a stainless steel alloy, and are joined together to form a body body 10, and a fluid flow path 11 is provided inside this body body 10.

In the body main body 10, a side wall portion 10a is formed on the side where the body member 1 is joined to the cap member 2 (left side in the figure), and the vicinity of its outer periphery rises toward the primary side. A screw 12 is formed. A secondary flow path 13 that is a secondary side of the fluid flow path 11 is formed on the inner periphery of the center side of the body member 10, and the secondary flow path 13 is wider on the side opposite to the cap member 2. It is formed with a diameter. A mounting portion 14 whose diameter is slightly enlarged toward the primary side is formed in the secondary flow path 13, and a valve seat portion 15 is formed on the inner peripheral side of the primary side of this mounting portion 14. A diameter-reduced abutment and locking surface 16 is formed on the secondary side (right side) of the mounting portion 14, and this abutment and locking surface 16 has one end side (right side end portion) of the spring member 4 elastically biased. ) is provided so as to be able to abut and lock.

On the inside of the side wall portion 10a of the body member 1, an opposing surface 20 is provided on the joint end surface side of the cap member 2, and the inner diameter side of the opposing surface 20 near the fluid flow path 11 has a diameter larger than that of the mounting portion 14. An annular step portion 21 is formed with a predetermined depth. This annular stepped portion 21 is provided with a slightly larger diameter than the outer diameter of the holder member 3.

An obtuse edge seal part 22 is formed on the outer diameter side of the annular step part 21 of the body member side facing surface 20 so as to bulge in a substantially tapered shape in the inner diameter direction, and further on the outer diameter side than this edge seal part 22. On the radial side, a diameter-enlarged annular recess 23 is formed following the edge seal portion 22 .

On the other hand, in the cap member 2, a male thread 30 that can be screwed into the female thread 12 is formed on the outer periphery of the side where it is joined to the body member 1 (the right side in the figure). A primary side flow path 31 forming the primary side of the fluid flow path 11 is formed on the inner periphery of the center side of the cap member 2, and this primary side flow path 31 has a larger diameter on the side facing the body member 1. It is formed.

An opposing surface 32 is provided on the end surface of the cap member 2 that is connected to the body member 1, and a stepped portion having a diameter larger than that of the fluid channel 11 is formed on the inner diameter side of the opposing surface 32 near the fluid channel 11. In this example, the annular step portion 33 is formed deeper in the flow path direction than the annular step portion 21 of the body member 1. The annular step part 33 is provided at a predetermined depth with a diameter that is approximately the same as the outer diameter of the holder member 3, and in this embodiment, the inner diameter of the annular step part 33 is set to the holder member so that a very small gap is provided between them. It is formed slightly larger than the outer diameter.

Further, on the outer diameter side of the annular step portion 33 of the cap member side facing surface 32, an obtuse edge seal portion 34 is protruded in a substantially tapered shape in the inner diameter direction so as to face the body member side edge seal portion 22. is formed to have a substantially symmetrical shape with the body side edge seal portion 22.

The edge seal portions 22 and 34 on the body member 1 side and the cap member 2 side described above are preferably formed with an angle α1 and an angle α2 of appropriate angles in the range of 160 to 178 degrees, respectively. In this embodiment, both angles α1 and α2 are obtuse angles of 170°.

The facing surface 20 and the facing surface 30 are spaced apart from each other on the outer diameter side of the respective edge seal portions 22 and 34, particularly on the outer diameter side of the gasket 8, and have a clearance G1. This clearance G1 allows further tightening of the cap member 2 and body member 3, and enables additional tightening when the sealing performance is degraded.

After the body member 1 and the cap member 2 are integrated, a housing space S of a predetermined width is formed near the opposing surface of the body main body 1 by the annular step portions 21 and 33, and inside this housing space S. , a holder member 3 is provided so as to be accommodated therein.
At the primary side (cap member 2 side) end of the body main body 10, there is a primary side joint 35 with a female thread, and at the secondary side (body member 1 side) end, there is a secondary side joint 36 with a female thread. An overflow prevention valve is provided so as to be connectable to a predetermined position of the piping equipment through the primary side joint portion 35 and the secondary side joint portion 36, respectively.

The holder member 3 is formed in a size that can be installed in the housing space S, and an annular groove 40 is formed on the outer diameter side of the holder member 3 facing the facing surface 20 of the body member 1. The buffer member 7 is attached to 40 by fitting. On the side of the holder member 3 that faces the facing surface 32 of the cap member 2, V-shaped notch grooves 41 are formed at two equal intervals from the center side to the outer circumferential side, and fluid passes through the notch grooves 41. It is now possible.

An accommodating portion 42 consisting of a communicating hole is formed on the inner diameter side of the notch groove 41, and the spring member 4 is provided in this accommodating portion 42 so as to be attachable thereto. In the figure, a diameter-reduced abutting and locking surface 43 is formed on the right side of the accommodating portion 42, and one end (right end) of the spring member 4 elastically biased comes into contact with this abutting and locking surface 43. It is provided so that it can be connected and locked. A valve seat portion 44 against which the first valve body 5 can abut and seal is formed on the left open end side of the accommodating portion 42 .

The buffer member 7 is made of a fluororesin material such as PTFE, and has an outer diameter and a thickness that allows it to come into contact with the opposing surface of the annular stepped portion 21 . This buffer member 7 is accommodated in the accommodation space S in a state in which it can be contracted between the holder member 3 and the body member 1 in accordance with the force of pressing them together. This buffer member 7 can be contracted according to the joining force when the cap member 2 and the body member 1 are joined together. It also has the function of fixing the holder member 3 to the main body 10.

Here, the facing surfaces of the holder member 3 and the body member 1, which face each other via the buffer member 7, are separated by a predetermined clearance G2. This clearance G2 needs to be provided at least as much as the amount required for tightening the cap member 2 and the body member 1 using the clearance G1, and may be set to the same extent as the clearance G1 at most.

Furthermore, if the amount of protrusion of the holder member 3 from the groove 40 toward the annular step 21 is too large, an excessive tightening force is required between the body member 1 and the cap member 2, while if it is too small, the annular step 21, and the holder member 3 cannot be fixed. Therefore, the amount of protrusion of the buffer member 7 needs to be at least large enough to allow the body member 1 and the cap member 2 to come into contact with each other in a tightened state. On the other hand, in order to eliminate the need for excessive tightening, the cushioning member 7 should be in contact with the annular stepped part 21, or not even slightly, with the edge seal part 22 and the edge seal part 34 in contact with the gasket 8. It is preferable that

A gasket 8 formed to have a larger diameter than the outer peripheral side of the holder member 3 is attached to the annular recess 23 . The gasket 8 is made of copper or a copper alloy, for example, and is inserted into the annular recess 23 and sandwiched between the annular recess 23 and the facing surface 32 on the cap member 3 side.
With this mounting structure, the holder member 3 is in a state where the gasket 8 is attached between the opposing surfaces 20 and 32 at the outer peripheral position, and the holder member 3 is placed in the housing space S so as to pass through the inner diameter side of the gasket 8. It is sandwiched between the body member 1 and the cap member 2 inside.

Since the cutout groove 41 is disposed between the holder member 3 and the cap member 2, a communication path T is formed near the primary side of the body 10 by the holder member 3 and the cap member 2. In this case, the opposing surface 32 of the cap member 2 and the holder member 3 are communicated through the notch groove 41 in the inner and outer circumferential directions, and following the notch groove 41, the inner circumference of the cap member 2 and the outer circumference of the holder member 3 are connected. A communication path T is provided by the very small gap provided. In this way, the communication path T extends from the primary side of the first valve body 5 through the gap with the annular stepped portion 21 on the outer peripheral side of the holder member 3 to the location where the buffer member 7 is attached. Provided in a communicating range.

A first valve body 5 and a second valve body 6 each formed in the shape of a poppet valve are mounted in series on the primary side and the secondary side of the holder member 3 housed in the housing space S, respectively. The first valve body 5 and the second valve body 6 constitute a two-stage overflow prevention valve.

The first valve body 5 and the second valve body 6 are formed of a resin material such as polyetheretherketone (PEEK) or polyimide (PI), which belong to super engineering plastics, for example. Disk portions 50 and 51 each having an enlarged diameter are formed in some of these portions, and seal portions 52 and 53 are formed at the secondary outer peripheral positions of these disk portions 50 and 51. are provided in the valve seat portions 44 and 15 described above so as to be able to abut and seal, respectively.

In both the first valve body 5 and the second valve body 6, short cylindrical portions 54 and 55 are formed on the primary side of each seal portion 52 and 53, and each short cylindrical portion 54 and 55 is formed on the primary side of each seal portion 52 and 53. The end face 56 of the primary flow path and the end face 57 of the secondary side of the holder member 3 are brought into contact with each other on the side. Each of the short cylindrical parts 54 and 55 is partially cut out to form a plurality of communication ports 58 and 59, respectively. Fluid flows in the state of contact. Long cylindrical portions 60 and 61 are formed on the secondary side of the seal portions 52 and 53 of each valve body, respectively, and a plurality of communicating holes are formed on the disk portions 50 and 51 side of each long cylindrical portion 60 and 61. 62 and 63 are formed, respectively. On the secondary side of the communication holes 62 and 63, diameter-reduced contact and locking surfaces 64 and 65 are formed, respectively, and each contact and locking surface 64 and 65 is provided with an elastically biased spring member. One end side (left side end portion) of 4 is provided so as to be able to abut and lock.

The long cylindrical portion 60 of the first valve body 5 is formed to have an outer diameter that can be inserted into the housing portion 42, and the long cylindrical portion 61 of the second valve body 6 is formed to have an outer diameter that can be inserted into the mounting portion 14. .
A through hole 70 is formed in the center of the disk portion 50 of the first valve body 5, and the seal portion 52 of the first valve body 5 contacts the valve seat portion 44 through this through hole 70. Even in this state (valve closed position), fluid flows to the secondary side with its flow rate being restricted. On the other hand, no through hole is formed in the disk portion 51 of the second valve body 6, and when the second valve body is closed, fluid flow to the secondary side is prevented.

Note that the second valve body 6 may also be configured to allow a slight amount of fluid to flow out to the secondary side in the valve closed position, depending on the case. As a means for this, it is possible to provide a through hole similar to that of the first valve body 5, or to provide a groove in the seal portion 53 or valve seat portion 15 of the second valve body 6, which may cause damage to the secondary side. It can also be set according to the amount of leakage from the second valve body 6 that is allowed during this time. By doing so, the second valve body 6 can quickly return to the valve open state after the cause of the excessive flow on the secondary side is eliminated.

The first valve body 5 is disposed within the primary flow path 31 of the cap member 2 between the cap member 2 and the accommodating portion 42 of the holder member 3, and its secondary side is loosely fitted into the accommodating portion 42. There is. A spring member 4 is housed between the abutment and locking surface 64 of the first valve body 5 and the abutment and locking surface 43 of the holder member 3 in an elastically biased state. 1 valve body 5 is resiliently biased toward the primary side (leftward in the figure) to maintain the valve open state. On the other hand, when fluid pressure is applied from the primary side, the first valve body 5 moves to the secondary side (rightward in the figure) against the elastic bias of the spring member 4, and the fluid pressure is applied to the spring member 4. When the spring force is exceeded, the seal portion 52 contacts and seals against the valve seat portion 44, and the valve is closed.

The second valve body 6 is disposed within the secondary flow path 13 of the body member 1 between the holder member 3 and the mounting portion 14 of the body member 1, and its secondary side is loosely fitted into the mounting portion 14. ing. The spring member 4 is accommodated between the abutment and locking surface 65 of the second valve body 6 and the abutment and locking surface 16 of the body member 1 in a spring-locked state, similar to the case of the first valve body 5. Under normal conditions, the second valve body 6 is elastically biased by the spring member 4 toward the primary side (leftward in the figure) to maintain the valve open state. On the other hand, when fluid pressure is applied from the first valve body 5 side, the second valve body 6 moves to the secondary side (rightward in the figure) against the elastic bias of the spring member 4, and the fluid pressure increases. When the elastic urging force of the spring member 4 is exceeded, the seal portion 53 contacts and seals against the valve seat portion 15, and the valve is closed.

In this case, if the spring force applied to the first valve body 5 by the spring member 4 is FA, and the force applied to the second valve body by the spring member 4 is FB, then these force FA<bounce force The relationship is set to be that of the biasing force FB. As a result, the first valve body 5 operates first, and then the second valve body 6 operates in two steps according to the differential pressure between the primary side and the secondary side of the body 10 centered on the holder member 3. It is now possible.

In the above embodiment, the buffer member 7 is attached to the holder member 3 on the side facing the opposing surface 20 of the body member 1. It is sufficient if it is mounted on the side opposite to the facing surfaces 20 and 32 of the side, and it may be provided so as to face the facing surfaces 20 and 32 of both the body member 1 and the cap member 2.

Further, the buffer member 7 may be fixed by providing a groove in the body member 1 or the cap member 2 instead of providing a groove on the holder member 3 side, or may be simply sandwiched therein. Furthermore, the buffer member does not necessarily have to be annular, and may be divided into a plurality of members, for example.

Furthermore, although the holder member 3 is fitted into and positioned in the annular step portions 33 and 21 provided on both the cap member 2 and the body member 1, it is possible to An annular stepped portion may be formed on one side, and the outer periphery of the holder member 3 may be fitted into this annular stepped portion for positioning.

The cutout grooves 41 of the holder member 3 may be formed in one place or in three or more places, and even when they are formed in three or more places, they are preferably formed radially at equal intervals from the center side to the outer circumferential side. . The notch groove 41 may be provided in a cross-sectional shape other than the V-shape, and for example, a notch groove with a rectangular cross-section may be formed.

When assembling the above excessive flow prevention valve, the body member 1 is arranged so that the surface 20 facing the cap member 2 faces upward, and the secondary side flow path 13 of the body member 20 is The spring member 4 and the second valve body 6 are attached, and the center part of the holder member 3 is placed on the second valve body 6, with the outer diameter side thereof being placed on the annular step part 21, and the holder member 3 is placed on the annular stepped part 21. The primary side spring member 4 is disposed in the accommodating part 42, and the long cylindrical part 60 of the first valve body 5 is inserted into the accommodating part 42 from above. At the same time, the gasket 8 is fitted into the annular recess 23 of the body member 1.

In this state, the female thread 12 and the male thread 30 are screwed together to join the body member 1 and the cap member 2. As a result, the holder member 3 is positioned in the housing space S, and the first valve body 5 and the second valve body 5 are elastically elasticized by the spring member 4 on the primary side and the secondary side of the holder member 3, respectively. It is attached in a biased state.

After the main body 10 is constructed, the body member 1 and the cap member 2 are sealed by the gasket 8. At this time, the gasket 8 is sandwiched between the obtuse-angled edge seal portions 22, 34, and the narrow sealing surfaces increase the clamping pressure, improving the sealing performance.

Next, the operation and effect of the above embodiment of the overflow prevention valve of the present invention will be explained.
In FIGS. 1 and 3, the first valve body 5 and the second valve body 6 are resiliently biased to the left by the spring member 4, and the end surfaces 56 and 57 of each valve body 5 and 6 are pressed against the cap member 2. , shows a state in which the holder member 3 is in contact with the opposing contact surfaces. In this case, the communication port 58, the communication hole portion 62, and the through hole 70 of the first valve body 5 and the communication port 59 and the communication hole portion 63 of the second valve body are connected to the primary flow path 31, the secondary flow path 13, The valves are kept open.

As a result, when high-pressure hydrogen (high-pressure fluid) flows from the left side of the figure at a normal flow rate, this fluid flows into the holder member 3 through the communication port 58 and the communication hole 62 on the cap member 2 side, and then this fluid The fluid flows to the secondary side through the communication port 59 and the communication hole portion 63 on the body member 1 side, and the fluid at the normal flow rate flows out. At this time, the communication ports 58, 59 and the communication holes 62, 63 have an opening area sufficient for the normal flow rate to flow, and prevent a pressure difference between the primary side and the secondary side from occurring. There is.

If damage occurs to equipment, valves, piping, etc. (not shown) on the secondary side of the overflow prevention valve, and the secondary flow rate becomes extremely larger than the normal flow rate, the fluid may not be able to flow through the opening area (nozzle area). A pressure difference occurs between the primary and secondary sides.

When this differential pressure increases, as shown in FIG. 4, from the relationship of elastic urging force FA applied to the first valve element 5 < elastic urging force FB applied to the second valve element, first, as shown in FIG. The first valve body 5, which has a smaller value, moves to the right in the figure, and the seal portion 52 seats on the valve seat portion 44, resulting in the valve being in a closed state. At this time, in order to maintain the state in which the through hole 70 communicates with the housing portion 42 of the holder member 3, the fluid continues to flow from the primary side to the secondary side through the through hole 70 at a constant flow rate smaller than the normal flow rate. . As a result, the through hole 70 becomes an orifice, the flow rate is restricted, and the fluid pressure on the primary side and the secondary side is reduced.

Furthermore, as the secondary flow rate of the overflow prevention valve increases, the pressure in the secondary flow path 13 also increases, but as the pressure in the secondary flow path 13 recovers, the pressure in the primary flow path 31 increases. The amount of fluid supplied from the side cannot keep up with the pressure difference, and the second valve body 6 moves to the right as shown in FIG. The flow path is blocked.

In this way, the overflow prevention valve has a two-stage structure including the first valve body 5 and the second valve body 6, and the first valve body 5 operates first, and then the second valve body 5 operates. By doing so, when excessive outflow occurs on the secondary side, each valve element 5, 6 can operate to reliably close the flow path while preventing damage or failure. On the other hand, if a primary rapid flow other than an excessive flow on the secondary side occurs, for example, such as a flow immediately after power is turned on, the first valve body 5 enters the valve closed state while ensuring a predetermined flow rate. This prevents the valve from becoming completely closed and prevents malfunction of the overflow prevention valve as a whole. Moreover, by not being in a completely closed state, when the temporary rapid flow is resolved, the first valve body 5 quickly returns to the open state.

A gasket made of copper or copper alloy that is attached to the holder member 3 with the buffer member 7 facing the opposing surface 20, and the holder member 3 is attached between the body member 1 and the cap member 2 at the outer peripheral position of the holder member 3. By sandwiching the gasket 8 in the accommodation space S through the gasket 8, the gasket 8 can be sandwiched between the body member 1 and the cap member 2 in the flow path direction and sealed. Therefore, even if a temperature difference occurs in the high-pressure fluid, such as when a low-temperature fluid flows, the gasket 8 is prevented from expanding or contracting, and the pressure contact force in the sandwiching direction maintains a state with sufficient sealing performance. Leakage can be reliably prevented.

Moreover, since the buffer member 7 is disposed between the holder member 3 and the body member 1, the tightening force between the body member 1 and the cap member 2 is adjusted through the elastic force of the buffer member 7, and the gasket 8 The body main body 10 can be assembled in a state where optimum sealing performance is exhibited, and the sealing performance can also be restored by retightening.

It is also possible to prevent an excessive gap between the holder member 3 and the accommodation space S through the buffer member 7, and to avoid chattering of the holder member 3 due to fluid.

Annular step portions 33 and 21 are formed on both opposing surfaces 32 and 20 of the cap member 2 and the body member 1, and the outer periphery of the holder member 3 is fitted between these annular step portions 33 and 21 for positioning. Therefore, with the first valve body 5, second valve body 6, and spring member 4 temporarily assembled through this holder member 3, the body member 1 and the cap member 2 can be easily integrated, and after assembly, the holder By locating the gasket 8 on the outer periphery of the member 3, the gasket 8 reliably prevents fluid leakage from the mounting side of the holder member 3.
Furthermore, since the annular stepped portions 33 and 21 are provided to form the housing space S, and the holder member 3 is fixed in the housing space S by clamping, a space for mounting the holder member 3 is required. It can be minimized, and the structure can be simplified and made more compact.

A communication path T is formed in the body main body 1, and this communication path T communicates the area from the primary side of the first valve body 5 to the outer peripheral side of the holder member 3 to the buffer member 7. When the first valve body 5 is in the open or closed state, the pressure between the primary flow path 31 and the buffer member 7 is equalized through the communication path T, and excessive fluid pressure to the buffer member 7 is removed. Avoid applying. Moreover, the communication path T is always ensured by the V-shaped notch groove 41 provided in the holder member 3 and the very small gap between the annular step portion 21 and the outer periphery of the holder member 3.

Note that a gap may also be provided between the buffer member 7 and the annular step portion 21 on the body member 1 side, as long as it has a structure that can block the secondary flow path 13 when the second valve body 6 is closed. , the flow path from the first valve body 5 side and the holder member 3 side to the second valve body 6 side may not be completely sealed.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and the present invention is not limited to the scope of the invention described in the claims of the present invention. It is possible to make various changes.

1 Body member 2 Cap member 3 Holder member 4 Spring member 5 First valve body 6 Second valve body 7 Buffer member 8 Gasket 10 Body main body 11 Fluid flow path 20, 32 Opposing surface 21, 33 Annular step portion S Accommodation space T Connection aisle

Claims (3)

A tubular body member and a cap member are joined to form a body body having a fluid flow path therein, and a cylindrical holder member communicating with the fluid flow path is accommodated near the opposing surface of the body body. A housing space is formed in which the holder member is housed, and a first valve body and a second valve body are elastically biased in the valve opening direction by a spring member, respectively, on the first and second sides of the holder member accommodated in this housing space. is attached in a state where the valve can be closed by fluid pressure, and the accommodation space is formed in one or both of the opposing surfaces of the cap member and the body member with a diameter larger than that of the fluid flow path. The outer periphery of the holder member is fitted into the annular step portion and positioned, and the first valve body and the second valve body are respectively on the primary side with respect to the holder member. and the second valve body is mounted in series on the secondary side, and the secondary side of the second valve body is loosely fitted into a mounting portion formed on the primary side of the fluid flow path. Prevention valve. 2. The excessive flow prevention valve according to claim 1, wherein a long cylindrical portion is formed on the secondary side of the second valve body, and the long cylindrical portion is formed to have an outer diameter that can be inserted into the mounting portion. The overflow prevention valve according to claim 1 or 2, wherein the mounting portion is formed in a secondary side flow path forming a secondary side of the fluid flow path, with the diameter slightly increasing toward the primary side.

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