JP6654420B2 - High pressure check valve and hydrogen station using it - Google Patents

Description

  The present invention relates to a non-return valve for high pressure, and more particularly to a non-return valve for high pressure used as an in-line check in a flow path such as a hydrogen station through which a high-pressure fluid such as hydrogen flows, and a hydrogen station using the same.

  In recent years, the supply infrastructure of hydrogen stations for fuel cells for automobiles is becoming widespread, and a check valve that is an in-line check is usually used as piping equipment for the hydrogen stations, in addition to valves for flow control. In this case, in the hydrogen station, for example, high-pressure hydrogen of about 99 MPa may flow, so that the check valve needs to be able to withstand an ultra-high pressure like the flow control valve.

  As a check valve for a high-pressure fluid, for example, a high-pressure check valve disclosed in Patent Document 1 is known. The check valve has a structure in which a poppet valve is fitted to the center of the valve body so as to be movable left and right with a spring interposed, and a meson having a center water hole at both ends thereof. The poppet valve reciprocates in the valve body while being guided by the center hole of the valve body. When the valve is opened, fluid flows through a vertical groove formed on the outer periphery of the poppet valve, and when the valve is closed, the poppet valve and The ends of the meson are in planar contact with each other, and the valve is closed.

  On the other hand, in the check valve of Patent Literature 2, a valve element is resiliently spring-urged in a valve closing direction, and a distal end side of the valve element is formed in a tapered shape, and an O-ring attached to the distal end has a tapered valve seat. The structure is such that the valve is kept closed by sitting on the seat. Further, in the check valve of Patent Document 3, a bent portion that can be in close contact with the O-ring of the valve body is formed in the valve seat, and the first inclined portion and the second inclined portion are formed starting from the bent portion. When the valve is closed, a valve body having an O-ring mounted on the valve seat side is seated to hermetically seal high-pressure fluid to extend the life of the seal member.

  Further, a check valve shown in FIG. 7 has also been proposed, which is formed by screwing an external thread portion 2 of a body 1 having a cylindrical space portion 3 and an internal thread portion 5 of a cap 4 to seal the body 1. The portion 6 and the seal portion 7 of the cap 4 are externally sealed with a metal touch, and a poppet valve element 8 attached to the end of the flow passage opening of the cap 4 via a spring is provided at the bottomed portion of the cylindrical space 3. The valve seat 9 is configured to be brought into contact with the valve seat 9 to seal the valve seat.

Japanese Utility Model Publication No. 60-85670 JP 2011-80571 A Japanese Patent No. 4791196

  However, in the check valve disclosed in Patent Literature 1, since the ends of the poppet valve and the intermediate element are sealed by planar contact, when these ends are metal surfaces, a gap is generated between the flat surfaces at high pressure. Leakage may occur. Further, the check valve is limited to a case where the pressure range is relatively high, and when a low-pressure fluid flows, a gap may be formed in a plane contact portion and a leak may occur.

  In a check valve using a rubber material such as an O-ring for a valve seat seal as disclosed in Patent Documents 2 and 3, when used as a check valve for ultra-high pressure in a hydrogen station or the like, it is durable due to erosion due to a high differential pressure flow rate. Worse. As a countermeasure against this erosion, it is conceivable to use a metal seal valve seat structure for the check valve. However, the sealing performance at low pressure of about 5 MPa is deteriorated, and as a result, the fluid has a wide range of pressure from low pressure to ultra-high pressure. Therefore, it is difficult to exhibit the non-return performance. In addition, in the case of a rubber seal, durability due to repeated opening / closing operations is deteriorated, and sealing performance is deteriorated due to a small number of opening / closing operations of several thousand times, which may cause leakage. In order to improve the durability, it is conceivable to increase the hardness by welding another material to the stainless steel valve body. However, in this case, it is difficult to carry out the method because the problem of hydrogen embrittlement newly occurs in the welded portion. Although it is conceivable to mold the entire valve body from a high-hardness material, in this case, there is a problem that it becomes expensive.

  Furthermore, non-return valves are originally provided at various locations in the piping system for various purposes, as well as in hydrogen stations. In particular, in recent years, there has been remarkable progress in technology development related to hydrogen stations. For this reason, in a system including a piping system for a high-pressure fluid such as a hydrogen station, a check valve that is more compact and simple while maintaining the above-described high sealing performance and durability is eagerly desired. Among them, a demand for a compact check valve having a reduced inter-valve dimension of a valve is particularly increasing.

  On the other hand, the applicant has proposed a high-pressure check valve in Japanese Patent Application No. 2012-136204 in order to solve the above-mentioned problem, but in recent years, as described above, a more compact and simpler structure has been realized. A check valve was desired.

  Further, the conventional check valve shown in FIG. 7 has a point that the seal part 6 and the seal part 7 are metal-touch-sealed, a point that the length of the screw connection part of the male screw part 2 and the female screw part 5 is long, It has such a drawback. In other words, if the outer seal structure is a metal touch seal instead of a gasket seal, the sealing performance is inferior.To ensure a reliable external seal with high durability and sealing performance against ultra-high pressure fluid such as 99 MPa hydrogen fluid, The threaded connection between the external thread 2 and the internal thread 5 must be lengthened. Actually, the length of the screw connection portion of the check valve in FIG. 7 is substantially equal to the fitting length of the body 1 and the cap 4, and is provided almost over the entire fitting portion.

  However, if the check valve is required to have further pressure resistance and it is necessary to increase the external seal to cope with this, if the length of the screw connection portion is approximately the same as the fitting length, the screw connection is not possible. It is not possible to change the design to increase the length of the joint to increase the external sealing force. Therefore, it must be said that the structure has low versatility and, hence, low usability, which is difficult to cope with design changes.

  Accordingly, the present invention has been developed to solve the above problems, and has as its object the high pressure resistance, durability and high pressure required for a high-pressure fluid such as ultra-high-pressure hydrogen in a hydrogen station. It is an object of the present invention to provide a high-pressure check valve which is simpler than conventional products, has a smaller face-to-face dimension, and has a compact structure, and a hydrogen station using the same, while having an accurate sealing property.

In order to achieve the above object, according to the first aspect of the present invention, a valve chamber having a cylindrical space portion is provided in a body that is a short cylindrical body having a predetermined thickness, and a spring force of a spring is provided in the valve chamber. in a built-in poppet valve body for closing, among the fitting length of the state fitted to the cap member on the outer peripheral surface of the body having a valve seat sealing surface with a U-shaped section, the body and the cap a portion of the length A threaded joint for screwing the body to the body via a metal gasket , an obtuse edge seal at the tip end surface of the body, and an obtuse edge seal at the back end of the cap body. A gasket is narrowed by the two edge seal portions to form an external seal portion, and the outer diameter portion of the front end surface and the inner end surface of the outer diameter side of the rear end surface facing the outer diameter portion are provided. is high-pressure check valve as a gap is formed between

  According to a second aspect of the present invention, the flat portion provided at the tip of the poppet valve body is brought into contact with the valve seat sealing surface, and the valve seat sealing surface is provided with an obtuse edge having an obtuse edge shape. Formed from a material with a lower flat surface hardness, the seal width between the obtuse edge portion and the flat portion is narrow at low pressure, and the flat portion deforms and seals the obtuse edge portion and the flat portion at high pressure. This is a high-pressure check valve with a wider width.

The invention according to claim 3 is a hydrogen station using a high-pressure check valve in a high-pressure hydrogen supply line.

  According to the first aspect of the present invention, a valve chamber is provided in a body that is a short cylindrical body having a predetermined thickness, and a poppet valve body that is closed by the elastic force of a spring is incorporated in the valve chamber. Since the cap body having a U-shaped cross section and having a valve seat sealing surface was fitted to the outer peripheral surface of the body, the operating area of the poppet valve body and the outer shell of the valve chamber having a sufficient thickness capable of supporting a high pressure were secured. However, the length of the cap body in the length direction of the flow path can be minimized. For this reason, it is possible to exhibit a check performance capable of closing the high-pressure fluid with a reliable sealing property, and to configure a compact check valve between small surfaces.

Further, since a screw connection portion for screw-connecting the body and the cap body via a gasket is provided in a part of the fitting length in a state where the cap body is fitted to the body, The length of the threaded joint and the body thickness can be changed according to the maximum operating pressure required for the stop valve. Versatility and usability can be improved. Furthermore, an obtuse edge seal portion is provided on the front end surface of the body, and an obtuse edge seal portion is also provided on the rear end surface of the cap body. The cap body can be attached to the body while receiving the outer diameter of the gasket on the entire gasket mounting surface and reliably preventing fluid leakage. Thus, a wide sealing surface utilizing the step surface of the cap body By doing so, high sealing performance can be exhibited even when the cap body is downsized in the radial direction, especially when the mounting of the body and the cap body is completed, such that the front end surface does not abut against the inner end surface. The extra space allows the body and cap body to be tightened and the gasket to be pinched, improving sealability. It is possible to achieve reduction.

  According to the invention as set forth in claim 2, the valve seat sealing surface is provided with an obtuse edge portion having an obtuse angle and an edge shape, and is formed of a material having a flat portion having a lower hardness than the obtuse angle edge portion. The seal width between the obtuse edge and the flat part is narrow, and at high pressure, the flat part is deformed so that the seal width between the obtuse edge and the flat part is widened. Leakage is reliably prevented and excellent check performance is achieved.When the valve is opened, a large flow rate is secured to increase the valve capacity. The limit of the number of times of operation can be extended, and in particular, it can be used as an in-line check suitable for an application fluid such as high-pressure hydrogen.

According to the third aspect of the present invention, the high-pressure check valve functions as an in-line check to prevent leakage of fluid from low pressure to ultra-high pressure, exhibit excellent check performance, and secure a large flow rate when the valve is opened. Reduce the frequency of maintenance by extending the limit of the number of times of operation of the valve element of this high-pressure check valve while improving the valve capacity and dramatically improving the durability and ensuring the sealing performance. Can provide a hydrogen station that can

It is the perspective view which showed the check valve for high pressures of this invention. It is sectional drawing which showed the valve opening state of the check valve for high pressures of this invention. It is sectional drawing which showed the valve closing state of the check valve for high pressures of this invention. FIG. 3 is a partially enlarged sectional view of FIG. 2. (A) is an enlarged sectional view of a main part showing a sealing state at low pressure, and (b) is an enlarged sectional view of a main part showing a sealed state at high pressure. It is a block diagram showing an example of a hydrogen station. It is sectional drawing which showed the conventional non-return valve.

  Hereinafter, an embodiment of a check valve for high pressure in the present invention is described in detail based on a drawing. The non-return valve for high pressure of the present invention is particularly suitable as a non-return valve for ultra-high pressure hydrogen fluid in a hydrogen station. FIG. 1 is an external perspective view of a high-pressure check valve of the present invention, FIG. 2 is a sectional view of the high-pressure check valve of the present invention in an open state, and FIG. 3 is a high-pressure check valve of the present invention. It is sectional drawing of the valve closing state of a check valve.

  1 to 3, the body 10 is formed in a substantially cylindrical shape by, for example, a stainless alloy (SUS316). One end of the body 10, on the right side in the figure, is formed with a pipe joint composed of a female screw 12, and a male screw of an external joint (not shown) can be screwed into the pipe joint 12. A reduced-diameter hole 13 is formed following the pipe joint 12, and a cylindrical space portion 14 (valve chamber) that communicates with the reduced-diameter hole 13 and has a larger diameter than the reduced-diameter hole 13 is provided in the body 10. I have.

  As shown in FIG. 4, an obtuse edge seal portion 16 is provided on the distal end surface 15 which is on the opening side of the cylindrical space portion 14 of the body 1 and which is opposed to the rear end surface 29 of the cap body 20 described later. The angle α1 of the edge seal portion 16 is about 160 to 178 degrees, and in the present embodiment, the angle α1 is an obtuse angle of 170 degrees. The gasket 17 can be sealed by the edge seal portion 16. An inspection hole 18 for airtightness inspection is provided between the pipe joint 12 and the reduced diameter hole 13 in the body 10.

  As shown in FIGS. 2 and 3, the body 10 has a predetermined pressure resistance against a high-pressure fluid. Therefore, the body 10 has a short, substantially cylindrical shape in the flow path direction. For this reason, as shown in FIG. 1, the check valve of the present invention is also thick and has a compact inter-plane dimension M. A part of the outer peripheral surface of the body 10 is provided with a male screw portion 19 having a length L.

  1 to 3, the cap body 20 is formed in a substantially cylindrical shape, for example, by a stainless alloy (SUS316), like the body 10. On one end side (left side in the figure) of the cap body 20 is formed a pipe joint composed of a female screw 22. A male screw of an external joint (not shown) can be screwed into the pipe joint 22. A reduced diameter hole 23 is formed following the pipe joint portion 22, and the reduced diameter hole 23 communicates with a fitting portion 24 which is a cylindrical space for fitting and attaching the body 10. An internal thread 25 having a length L is provided on a part of the inner peripheral surface of the fitting portion 24. Inspection holes 26 for airtightness inspection are provided as appropriate between the pipe joint 22 and the reduced diameter hole 23 and near the bottomed portion on the inner side of the fitting portion 24.

  As shown in FIG. 4, a rear end surface 29 of the cap body 20 (an opening end surface in which the reduced-diameter hole 23 opens toward the internal fitting portion 24 (a surface facing the poppet valve body 40 described later)) is provided. The valve seat sealing surface 27 is formed with an obtuse edge portion 28 having an obtuse edge shape.

  Here, as described later, in the high-pressure check valve of the present invention, the poppet valve element 40 is mainly housed in the cylindrical space portion 14 of the body 10 and the valve seat closed by the poppet valve element 40. A sealing surface 27 is provided on a rear end surface 29 of the cap body 20. As described above, the valve seat sealing surface 27 having the obtuse edge portion 28 formed in a specific shape is not formed inside the cylindrical space portion 14 (the body 10 side) where the space is narrow and is difficult to process, but is widely opened and easily processed. Since it is provided on the side end surface 29 (on the side of the cap body 20), the valve seat sealing surface 27 (the obtuse edge portion 28) can be easily formed.

  In FIG. 4, the obtuse edge portion 28 has a cross section having a mountain shape, and the angle θ of the mountain is provided at about 160 to 178 degrees. In the present embodiment, the angle between the inner diameter side and the outer diameter side of the obtuse angle edge portion 28 is set. The taper angles are different. In FIG. 4, the inner diameter side taper angle θ1 is formed at 5 ° and the outer diameter side taper angle θ2 is formed at 2 °, and the angle θ of the obtuse edge portion 28 is set at an obtuse angle of 173 ° by these taper angles θ1 and θ2. Have been. The outer diameter side taper angle θ2 is formed to be smaller than the inner diameter side taper angle θ1 because the seal diameter (seal edge diameter Ds) described later is reduced when the pressure is low, and the poppet valve body 40 is set when the pressure is high. This is for widening the seal width with the flat portion 41 described later in the outer diameter direction. Thereby, it is possible to reliably seal from low pressure to high pressure. The vicinity 28a of the apex of the obtuse edge portion 28 does not need to be sharp, and may have a section R shape with a small radius. The outer diameter side taper angle θ2 may be set to be larger than 0 °, for example, 1 °. In the present embodiment, 0 ° <θ2 <5 °, and more preferably, 1 ° <θ2 <3. It is better to set in the range of °.

  In FIG. 4, a rear end surface 29, which is a position facing the distal end surface 15 of the body 10, is formed on the outer diameter side of the valve seat seal surface 27 of the cap body 20. An inner end surface 36 is formed, and the gasket 17 can be mounted on the inner end surface 36 on the inner end surface 29. An obtuse edge seal portion 30 is formed on the rear end surface 29, and the angle α2 of the edge seal portion 30 is, for example, about 160 to 178 ° like the edge seal portion 16 of the body 10. In the present embodiment, the angle α2 is provided at the same obtuse angle of 170 ° as the angle α1.

  As shown in the figure, in the present embodiment, when the mounting of the body 10 and the cap body 20 by screwing is completed, the gap between the outer diameter portion of the distal end surface 15 and the inner end surface 36 facing this outer diameter portion is obtained. A gap G (0.2 mm or the like) is formed in the gap. When the mounting of the body 10 and the cap body 20 is completed, a margin is provided so that the front end face 15 does not abut on the inner end face 36, so that the body 10 and the cap body 20 are tightened and the gasket 17 To improve the sealing performance. Although the gap G shown in FIG. 4 shows only the lower side, the gasket 17 and the gap G have a symmetric structure, and only the lower side is shown in FIG.

  FIGS. 2 and 3 show a state in which the body 10 is fitted to the fitting portion 24 of the cap body 20, and the male thread 19 of the body 10 and the female thread 25 of the cap 20 are screwed and attached. As shown in the figure, the cap body 20 has a U-shaped cross section including a cylindrical portion 31 and a thick shield portion 32, and the length L ′ is the length of the cylindrical portion 31 (the depth of the fitting portion 24). ), The length l indicates the thickness of the shielding thick part 32. By setting the length L ′ and the thickness l to the minimum necessary according to various characteristics such as pressure resistance required for the check valve of the present invention, the inter-surface dimension M and the wall thickness are minimized. The check valve can be made more compact.

  The length of the screw connection portion for screwing the body 10 and the cap body 20 through the gasket 17 is the screw length of the screw portion where the male screw portion 19 and the female screw portion 25 are screwed. , Equal to the shorter of the screw length of the external thread 19 or the internal thread 25. In the present embodiment, the male screw portion 19 and the female screw portion 25 are both provided with a length L, and each is screwed with the entire length, so that the length of the screw connection portion is also L. As shown in the attached state in FIGS. 2 and 3, the screw connection portion starts from the outer end 33 of the cap body 20 (the end on the opening side of the fitting portion 24), and the inner peripheral surface of the fitting portion 24. The length of the fitting between the body 10 and the cap body 20 is the same as the depth L ′ of the fitting portion 24. Since they are equal, the length L of the screw connection portion is a part of the fitting length L ′ of the body 10 and the cap body 20 starting from the right end in FIG. In the figure, the length L of the screw connection portion is set to be equal to or less than の of the fitting length L ′. However, since the length L can be freely set under predetermined conditions, For example, the length may be set to 2/3 or less of the length L '.

  As shown in FIGS. 2 and 3, the outer peripheral side surface of the body 10 on the tip end surface 15 side other than the male screw portion 19 is a cylindrical fitting portion 10 a. Further, a short large-diameter portion 25b having an increased diameter is formed on the inner side following the female thread portion 25 of the cap body 20, and inserted into the fitting portion 24 on the inner side following the large-diameter portion 25b. A tapered portion 25a through which the inserted body 10 can be inserted and guided is formed. Following the tapered portion 25a, a cylindrical deep-side small-diameter portion 24a, which is a bottom side surface of the inner peripheral side surface of the fitting portion 24, is provided behind the tapered portion 25a. Is formed. The rear-side small-diameter portion 24a is positioned opposite to the fitting portion 10a when the mounting of the body 10 is completed, and a space X is formed between the body 10 and the large-diameter portion 25b and the tapered portion 25a. Has become.

  The length a in the body 10 shown in FIGS. 2 and 3 is equal to the length (L′−L) obtained by subtracting the length L of the screw connection portion from the fitting length L ′, and the length in the cap body 20. b is equal to the length obtained by subtracting the length (depth) of the inner small-diameter portion 24a from the fitting length L '.

  Further, as shown in FIGS. 1 to 3, in a state where the body 10 and the cap body 20 are screwed together, the outer end face 33 of the cap body 20 is located outside the pipe joint 12 side (the right side in the drawings) of the body 10. By being substantially coplanar with the end face 35 (the outer end faces 33 and 35 are flush), the length L 'is as long as possible, so that future specification changes as will be described later can be made. In addition to being able to cope with the problem, the shape is such that the overall thickness is M and the dimension M between the surfaces gives a compact impression.

  It should be noted that the body and the cap body in the present invention are relative positions, and it is naturally possible to name the body as the cap body and the cap body as the body. Further, the high-pressure check valve having the body, the cap structure, and the outer seal structure according to the present invention can of course be applied to a high-pressure filter by using a filter structure as an internal structure.

  Here, the pressure resistance of the check valve formed by screwing and connecting the body 10 and the cap body 20 depends on the thickness of the body 10 forming the valve chamber and the screwing length of the screw of the screw connection portion. However, since the non-return valve of the present invention is externally sealed via the gasket 17, it has a higher sealing property than the non-return valve which is externally sealed by the metal touch shown in FIG. 7, and has a maximum working pressure (99 MPa). Therefore, it is not necessary to provide the length of the screw connection portion about the entire length as in the fitting length of the body 1 and the cap 4, and as described above, the length of the fitting portion L 'is one. The length L of the part is sufficient. For this reason, when further high pressure is required in the future, it is necessary to increase the thickness of the body 10 and the length of the screw connection portion. It can be extended to about L '. Therefore, it is only necessary to change the body thickness and screw fitting for high pressure, and since there is a design margin under the condition of the same surface spacing, future specification changes are possible. The structure is easy to handle.

  In particular, the check valve according to the present invention is designed such that the length L of the screw connection portion (the length of the male screw portion 19 and the female screw portion 25) is limited to the fitting length L ', and the required maximum withstand pressure and the like are required. Accordingly, when the lengths a and b are set to a> b, for example, when the body 10 is inserted into the cap body 20 at the time of assembling the check valve, the body 10 is fitted. The distal end of the insertion side of the portion 10a reaches the tapered portion 25a before the male screw portion 19 meshes with the female screw portion 25, and can start screwing in a state in which the fitting portion 10a is inserted and guided by the back side small diameter portion 24a. Therefore, the screw connection of the screw connection portion can be easily performed. In addition, when the length a for guiding the insertion is longer than the screw length b, the holding force of the shaft center of the body 10 by the fitting portion 10a increases, so that the male screw portion 19 and the female screw portion 25 are advanced by the screw advance. The distal end surface 15 that advances toward the side can reliably pinch the gasket 17 in a state in which the shaft center is not shaken or rattled by the screw advancement, and the sealing performance of the external seal portion 34 is improved. Can be.

Also, although not shown, in the present embodiment, the length of the screw of the male screw portion 19 is set to be longer than the length of the screw of the female screw portion 25 by a predetermined length (for example, 2 mm). The length L of the screw connection portion can be ensured even if the screwing of the screw member into the cap body 20 is slightly shifted. The space X shown in FIGS. 2 and 3 is a space capable of accommodating an increase in the screw length of the male screw portion 19 with respect to the screw length of the female screw portion 25 when the attachment of the body 10 and the cap body 20 is completed. I have.

  In order to attach the body 10 to the cap body 20, the gasket 17 is attached to the rear end face 29 of the cap body 20, and then the female thread 25 of the cap body 20 is screwed and connected to the male thread 19 of the body 10. As a result, the external seal portion 34 is provided between the cap body 20 and the body 10. The outer seal portion 34 is formed by sandwiching and sealing the metal gasket 17 with both the edge seal portion 16 on the body 10 side and the edge seal portion 30 on the cap body 20 side.

  The gasket 17 is formed of, for example, copper or a copper alloy, and is sandwiched between the edge seal portions 16 and 30 by screwing the external thread portion 19 of the body 10 and the internal thread portion 25 of the cap body 20. I have. The gasket 17 prevents leakage between the body 10 and the cap body 20.

  The poppet valve body 40 shown in FIGS. 2 and 3 has a flat portion 41 at the tip, and a cylindrical portion 42 that is continuous in the axial direction of the flat portion 41, and an outer periphery and a cylindrical portion 42 of the poppet valve member 40. And a flow passage hole 43 for communicating the same. Four flow path holes 43, which are communication paths, are arranged on the outer peripheral side of the poppet valve body 40 between the flat portion 41 and the cylindrical portion 42 at every 90 ° in the radial direction. The reduced diameter hole 13 and the reduced diameter hole 23 can communicate with each other. An outer peripheral opening in the flow passage hole 43 is provided on an inclined surface 44 provided on the outer periphery of the poppet valve element 40. Although not shown, the outer diameter D3 of the cylindrical portion of the flat portion 41 and the outer diameter D4 of the cylindrical portion of the cylindrical portion 42 are set to have a relationship of outer diameter D3 <outer diameter D4. The valley of the inclined surface 44 of the present embodiment is set to have a smaller diameter than the outer diameter D3 of the flat portion 41. Thereby, a concave portion is formed in the outer periphery of the poppet valve body 40 near the inclined surface 44, and the fluid is efficiently guided. The poppet valve body 40 is mounted on the cylindrical space portion 14 of the body 10 via a spring 45 formed of a coil spring, and the spring portion 45 allows the flat portion 41 to abut on the valve seat sealing surface 27. .

  The poppet valve body 40 is formed of a material having a relatively low hardness so that the flat portion 41 has a lower hardness than the obtuse edge portion 28. In the present embodiment, the material of the poppet valve body 40 is a resin, and this resin is a material having a hardness lower than the hardness of the cap body 20 having the obtuse edge portion 28 and has a high strength necessary for sealing the high-pressure fluid. It is made of material. The resin is, for example, polyetheretherketone (PEEK) or polyimide (PI) belonging to super engineering plastic. In the present embodiment, a poppet valve body is formed using a mixture of PEEK and 30% graphite. did. In the present embodiment, “the flat portion 41 is lower than the hardness of the obtuse edge portion 28” means that the seal width between the flat portion 41 and the valve seat seal surface 27 of the obtuse edge portion 28 is increased with an increase in fluid pressure. The hardness is such that the flat portion 41 is elastically deformed so that the seal width becomes narrower as the fluid pressure decreases while the fluid pressure decreases.

  Due to the poppet valve element 40 having such a low hardness, the seal width W1 between the obtuse edge portion 28 and the flat portion 41 at the time of low pressure is reduced as shown in FIG. As shown in FIG. 5B, the flat portion 41 is deformed, and the seal width W2 between the obtuse edge portion 28 and the flat portion 41 is increased. Four flow passage holes 43 communicating with the inner peripheral side are provided at equal intervals, and when the valve is opened, the diameter-reduced hole 13 and the diameter-reduced hole 23 can be communicated via the flow path hole 43.

The poppet valve element 40 is built in the valve chamber so as to be closed by the resilience of the spring 45, is guided in the cylindrical space portion 14 of the body 10 so as to be reciprocally movable in a state of being loosely fitted thereto. It is urged in the direction of the cap body 20 by the generated force. In this case, by providing the cylindrical portion of the poppet valve element 40 to be approximately twice as long as the cylindrical portion, the poppet valve element 40 slides inside the body 10 while maintaining the sealed state while preventing the inclination. It is movable.
The hole areas of the four flow passage holes 43 of the poppet valve element 40 and the valve seat opening area of the cap body 20 when the poppet valve element 40 is opened (the opening area of the diameter-reducing hole 23) are determined by the diameter-reducing holes of the body 10. 13 is larger than the area.

  When installing the high-pressure check valve, the poppet valve body 40 is mounted on the cylindrical space portion 14 of the body 10 in a resilient state by a spring 45, and the cap body 20 is screwed onto the body 10 to be integrated. The gasket 17 is interposed between the distal end face 15 of the body 10 and the rear end face 29 of the cap body 20 as described above, and is screwed to the external thread 19 of the body 10 and the internal thread 25 of the cap body 20. As a result, the gasket 17 is sandwiched between the edge seal portions 16 and 30.

Next, the operation of the high-pressure check valve of the above-described embodiment will be described.
FIG. 2 shows a valve open state of the check valve. In the drawing, when a high-pressure fluid flows from the left, the poppet valve body 40 is pressed rightward against the resilience of the spring 45 by the fluid pressure, and the valve seat seal surface 27 of the cap body 20 is opened. As shown by the arrow, the fluid flows from the reduced diameter hole 23 to the cylindrical space portion 14, is guided into the poppet valve body 40 through the flow passage hole 43, and is transmitted from the reduced diameter hole 13 through the bopet valve body 40. It flows outside the body 10. As described above, the hole area of the flow path hole 43 and the valve seat opening area of the cap body 20 are provided to be larger than the flow area of the body 10, thereby ensuring a high Cv value.

  In FIG. 3, when the fluid is going to flow backward, the poppet valve body 40 is pushed to the left by the fluid pressure, and the flat portion 41 is pressed against the valve seat sealing surface 27. At this time, the flat portion 41 is elastically deformed according to the increase of the check pressure, and abuts and seals on the valve seat seal surface 27 while increasing the contact area.

FIG. 5 illustrates the change in the contact state of the valve seat due to the difference in the magnitude of the check pressure at this time.
When a check pressure is applied to the poppet valve element 40, first, the flat portion 41 contacts the obtuse edge portion 28 of the valve seat sealing surface 27, and then the flat portion 41 follows the obtuse valve seat sealing surface 27. So that it abuts. The smaller the seal edge diameter Ds when the obtuse edge portion 28 seals, the smaller the load required for sealing, the smaller the seal edge diameter Ds.

  At the time of this sealing, at the time of low pressure, as shown in FIG. 5A, the flat portion 41 abuts and seals on the valve seat sealing surface 27 with a sealing width W1. In this case, since the force with which the poppet valve body 40 is pushed toward the cap body 20 is weak, the seal width W1 between the obtuse edge portion 28 and the flat portion 41 is narrow. Since the valve seat sealing surface 27 and the flat portion 41 are sealed by the narrow sealing width W1, high sealing performance is exhibited.

  On the other hand, at the time of high pressure, as shown in FIG. 5B, the flat portion 41 abuts and seals on the valve seat seal surface 27 with a seal width W2. In this case, since the force with which the poppet valve body 40 is pushed toward the cap body 20 is strong, the seal width W2 is wider than the seal width W1. Since the valve seat seal surface 27 and the flat portion 41 are sealed with such a wide seal width W2, the sealing performance is enhanced and the high-pressure fluid can be reliably stopped. In addition, since the force applied per unit area of the flat portion 41 can be reduced by increasing the seal width, the durability is improved, so that high sealing performance can be maintained for a long period of time.

  In this case, by setting the seal edge diameter Ds of the poppet valve body 40 to the minimum size and providing the oblique edge portion 28 with the inner side taper angle θ1 of 5 ° and the outer side taper angle θ2 of 2 °, particularly high pressure In some cases, the flat portion 41 is deformed while the seal width W3 is formed so as to spread outward, and high sealing performance can be exhibited, and the durability is further improved. For example, by adjusting the taper angles θ1 and θ2 and providing a gap C at which the elastic deformation amount of the flat portion 41 becomes 0.03 mm on the inner diameter side of the obtuse edge portion 28, the seal width W2 can be set to about 1.2 mm. The seal width W2 makes it possible to withstand a high check pressure. As described above, it is desirable to set the angle of the valve seat sealing surface 27 so as to be within the elastic displacement of the poppet valve body 40.

  As described above, in the check valve of the present invention, the male thread is formed on the side of the body member in which the valve chamber is formed, and the thickness required for a predetermined pressure resistance is mainly secured on the side of the body member. In addition, a female screw is formed on the cap member side, and when the screw member is screwed together, the cap member covers the body member with a minimum necessary thickness so that the cap member has a U-shaped cross section including a cylindrical portion and a shield thick portion. It is formed in a shape. With this structure, the check area can be made compact by minimizing the face-to-face dimension while maintaining the operating area of the poppet valve element and the required pressure resistance. Further, since the sleeve 10 and the like are not used, when the body 10 and the cap body 20 having the valve seat sealing surface 27 are each formed by a single member, the number of parts and the productivity and workability are reduced. High value.

  Further, the body 10 and the cap body 20 are screwed and connected via the gasket 17, the poppet valve body 40 is mounted in the cylindrical space portion 14 via the spring 45, and the poppet is mounted on the valve seat seal surface 27 of the cap body 20. The flat portion 41 of the valve body 40 is provided so as to be able to abut, the obtuse edge portion 28 is provided on the valve seat sealing surface 27, and the flat portion 41 is formed of a material having a hardness lower than that of the obtuse edge portion 28. I have. When the pressure is low, the seal width W1 between the obtuse edge portion 28 and the flat portion 41 is narrowed, and when the pressure is high, the flat portion 41 is deformed and the flat portion 41 and the obtuse edge portion 28 are deformed. , The flat portion 41 is deformed by a different deformation amount in accordance with the pressure to exhibit a necessary sealing surface pressure with respect to a fluid having a wide range of pressure from low pressure to high pressure. I do. Thereby, for example, the non-return performance can be reliably exerted in the case of a low-pressure fluid of 5 MPa or an ultra-high pressure fluid of 99 MPa, and even when used as a check valve for an ultra-high pressure, let alone a high pressure, a low pressure fluid. Even at times, it is possible to reliably exhibit the non-return performance and prevent leakage. In addition, since it can be provided by a simple combination with a small number of parts, it can be manufactured at low cost.

  In FIG. 4, an obtuse edge seal portion 16 is formed on the distal end surface 15 of the cylindrical space portion 14 of the body 10, and an obtuse angle edge seal portion 30 is formed on the back end surface 29 of the cap body 20. Since the metal gasket 17 is sandwiched between the seal portions 16 and 30 to form the external seal portion 34, these edge seal portions are formed similarly to the case of sealing the valve seat seal surface 27 and the flat portion 41. The body 10 and the cap body 20 can be sealed by exhibiting a high sealing surface pressure by means of 16 and 30.

  FIG. 6 shows a block diagram of a hydrogen station using the high-pressure check valve of the present invention. The hydrogen station includes, for example, a pressure accumulator 70, a compressor 71, a dispenser 72, a precool heat exchanger 73, a quick fitting 74, a filling hose 75, a filling nozzle 76, a vehicle tank 77, and a high-pressure hydrogen supply line 78. The system is configured as

  The valve body 85, which is a high-pressure check valve of the present invention, is provided, for example, as an in-line check at an appropriate location on the secondary side of the dispenser 72 (such as an inlet location of the supply line 78), or various other locations. The valve body 85 prevents hydrogen from leaking to the primary side and exhibits excellent non-return performance, while ensuring a large flow rate when the valve is opened, and has extremely high durability and sealing properties. .

  In addition, a manual valve 81 is provided at a connection portion of each unit of the hydrogen station, and an automatic valve 80 is appropriately provided on a primary side or a secondary side of each unit. The inside of the pressure accumulator 70 is divided into a plurality of tanks, and a predetermined pressure is set by appropriately switching a valve 80 connecting each tank to the compressor 71 and a valve 80 connecting each tank to the dispenser 72. While supplying hydrogen to the dispenser from the tank which has reached the predetermined pressure, the tank below the predetermined lower limit pressure is filled with hydrogen from the compressor 71 until the pressure reaches the predetermined pressure. In the supply line 78 provided in the hydrogen station, the supply of hydrogen is controlled by a predetermined program, and the supply of hydrogen can be controlled appropriately according to the supply amount of the vehicle.

  Further, the present invention is not limited to the description of the above embodiment, and various changes can be made without departing from the gist of the invention described in the claims of the present invention.

10 Body 14 Cylindrical space (valve chamber)
15 front end surface 16 edge seal portion 17 gasket 19 external thread portion 20 the cap member 25 because the screw portion 27 valve seat sealing surface 28 obtuse edge portion 29 inner side end face 30 edge seal portion 33 the outer end face 34 outside the sealing portion 40 the poppet valve body 41 flat portion 45 Spring 78 Supply line L Length of screw connection part L 'Fit length M Face-to-face dimension

Claims (3)

A valve chamber consisting of a cylindrical space is provided in a body that is a short cylindrical body having a predetermined thickness, and a poppet valve body that is closed by the elastic force of a spring is built in the valve chamber, and has a U-shaped cross section. of the fitting length of the state where the cap member fitted to the outer peripheral surface of said body having a valve seat sealing surface, a portion of the length of the body and cap that binds screwed through the metal gasket A threaded joint portion is provided , an obtuse edge seal portion is provided on the tip end surface of the body, and an obtuse edge seal portion is also provided on the rear end surface of the cap body. So that a gap is formed between the outer diameter portion of the front end surface and the outer diameter side inner end surface of the rear end surface facing the outer diameter portion. high-pressure check valve, characterized in that the.   The flat portion provided at the tip of the poppet valve body contacts the valve seat sealing surface, and the valve seat sealing surface is provided with an obtuse edge having an obtuse-angled edge shape. Formed from a material with low hardness, the seal width between the obtuse edge and the flat portion is small at low pressure, and the seal width between the obtuse edge and the flat portion is high at high pressure. The high-pressure check valve according to claim 1, wherein A hydrogen station using the high-pressure check valve according to claim 1 or 2 in a high-pressure hydrogen supply line.

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