valve

Abstract

The valve (10) of one embodiment of the present application has a valve body (1) having a space in which a valve stem (3) and a ball (4) are housed, and a middle cover (60) that fixes the ball (4) in the space liquid-tightly divides a portion of the space in which the valve stem (3) is housed and a portion of the space in which the ball (4) is housed.

Description

TECHNICAL FIELD

[0001] The present application relates to a valve, for example, a valve through which a very low temperature fluid such as liquid hydrogen flows. BACKGROUND

[0002] For a valve through which a very low temperature fluid such as liquid hydrogen (-253°C) flows, a valve stem connecting an operating portion of the valve and a valve core is lengthened so as to minimize heat conduction and heat transfer from the fluid, thereby having a cold insulation effect, and is configured so that a low temperature resistant member (packing or the like) is as far as possible from the fluid. In addition, a valve for a very low temperature is configured so as to be inside a jacket (vacuum jacket) that is maintained in a vacuum in order to maintain a low temperature, and in this case, the valve body is disposed inside the vacuum jacket and the operating portion is disposed outside the vacuum jacket. For example, in Patent Literature 1, a vacuum jacket type butterfly valve having a vacuum jacket and a butterfly valve and a valve stem configured to be long is disclosed.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 59-37382 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] From the viewpoint of preventing leakage, the valve body of the valve for liquid hydrogen among low temperature fluids is preferably an integrated structure in which a plurality of parts constituting the valve body are joined to each other by welding. In addition, the valve for liquid hydrogen is desired to have the vacuum jacket described above provided in a region from a valve core tank for housing the valve core to an operating portion for operating the opening and closing of the valve core. Therefore, it is necessary to house the valve stem connecting the valve core and the operating portion in the integrated structure of the valve body. For this reason, the diameter of the valve body needs to be able to pass the valve core.

[0008] On the other hand, in the case of such a configuration, a member for preliminarily holding the valve core at a prescribed position is required. In this regard, in Patent Literature 1, it is described that a valve core tank fixing shaft (reference numeral 6 in Patent Literature 1) is provided, the valve core tank fixing shaft has a small diameter cylinder through which a valve core rod is inserted, and a hollow chamber is formed outside the small diameter cylinder thereof.

[0009] However, in the structure described in Patent Literature 1, in order to preliminarily hold the valve core at a prescribed position, the valve core tank fixing shaft having a complicated structure is required, and therefore there is a problem that the manufacturing cost and the maintenance cost increase. In addition, there is a problem that the temperature on the valve core side is easily transferred to the hand wheel due to heat conduction of the valve core tank fixing shaft itself.

[0010] Therefore, an object of one embodiment of the present application is to realize a valve that suppresses an increase in manufacturing cost and maintenance cost and is applicable to an extremely low temperature fluid.

[0011] Technical solution to solve the problem

[0012] To solve the above problem, a valve according to one aspect of the present application includes a valve body having a plurality of first opening portions for allowing fluid to pass therethrough and a second opening portion opening in a direction intersecting with directions in which the plurality of first opening portions face and allowing a valve spool to pass therethrough, the valve spool housed in the valve body via the second opening portion and capable of opening and closing a fluid passage, a valve stem connected to the valve spool and extending to a position further outward than the second opening portion, a valve cover sealing the second opening portion in a manner allowing the valve stem to operate, and a middle cover body dividing a space in the valve body into a space on the valve cover side and a space on the valve spool side in a manner allowing the valve stem to operate and in a liquid-tight or gas-tight manner.

[0013] Effect of the invention

[0014] According to one aspect of the present application, a valve that suppresses an increase in manufacturing cost and maintenance cost and makes it difficult for heat on the valve spool side to be transmitted to a hand wheel can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a perspective view showing an external appearance of a push-in valve according to one embodiment of the present application.

[0016] Figure 2 is a sectional view showing a state after the valve is cut along a cutting line A-A' shown in Figure 1 .

[0017] Figure 3 is a sectional view showing a state after a vacuum jacket is attached to the valve shown in Figure 1 . Figure 1

[0018] Figure 4 Figure 2 is an enlarged sectional view of a frame portion B shown by a single-dot chain line.

[0019] Figure 5 is an enlarged sectional view of a frame portion C shown by a single-dot chain line. Figure 2

[0020] Figure 6 is a sectional perspective view showing a structure of a part of a push-in valve according to another embodiment of the present application.

[0021] ​​​Figure 7 is a sectional view illustrating a structure of a portion of the valve of

[0022] Figure 8 is a sectional view illustrating a structure of a portion of the valve of Figure 7 DETAILED DESCRIPTION

[0023] [Embodiment 1]

[0024] Hereinafter, one embodiment of the present application will be described with reference to FIGS. 1 to 8. The valve of one embodiment of the present application is generally exemplified by a poppet valve configured to be arranged in the middle of a flow path formed in a horizontal direction, but this does not limit the present embodiment and can be a valve other than a poppet valve. Figures 1 to 5 The valve of the present embodiment can cause a fluid flowing in the flow path from a position more upstream than the valve element to flow to a position more downstream than the valve element or cut off the fluid. As the fluid flowing in the flow path, a well-known liquid or a well-known gas can be used. However, the valve of one embodiment of the present application can be used as a valve for the above-described extremely low temperature fluid, and can be preferably used as a valve for liquid hydrogen.

[0025]

[0026] is an appearance perspective view of the valve 10 in one embodiment of the present application. Figure 1 is a sectional view illustrating a state after the valve is cut along the cutting line A-A' shown in FIG. 1. Note that in FIGS. 1 and 2, a three-dimensional coordinate system in which a horizontal plane is set as an XY plane and a zenith direction is set as a Z direction is illustrated. Figure 2 Figure 1 Figure 1 Figure 2

[0027] The valve 10 of the present embodiment is configured as a so-called ball valve. Thus, the valve 10 includes a valve body 1, a ball 4 (valve element) of a ball valve, a valve stem 3, a valve cover 2, and an operation portion 9.

[0028] The valve body 1 has a plurality of first opening portions (pipe structure portions 7) for passing a fluid and an upper end opening portion 6b (second opening portion) through which the ball 4 can pass, and the upper end opening portion 6b is opened in a direction (Z-axis direction described later) intersecting a direction (X-axis direction described later) in which the plurality of first opening portions (pipe structure portions 7) are directed, and the valve body 1 constitutes a flow path of the fluid. In addition, the valve stem 3 constitutes a flow path of the fluid along the Z-axis direction. Figure 2 ​​​​​The valve spool shaft extending in the vertical direction is connected to the ball 4 (valve spool) of the ball valve and extends to a position further outward than the upper end opening 6b. In addition, the bonnet 2 seals the upper end opening 6b in a manner that allows the valve stem 3 to operate. The bonnet 2 closes the upper end opening 6b (second opening) and is detachably connected to the upper end of the valve body 1 by a bolt or the like. An operation portion 9 is fixed to the bonnet 2, and operation by the operation portion 9 is transmitted to the ball 4 via the valve stem 3. The operation is performed by a hand wheel 99 Figure 1 ) provided on the bonnet 2. Specifically, the ball 4 is rotated about the center axis O ( Figure 2 ) extending in the vertical direction in accordance with the amount of rotation of the hand wheel 99. In the present embodiment, the opening and closing of the flow path by the ball 4 can be changed from the closed state to the open state by rotating 90°. Figure 2 The state illustrated in the figure is a state in which the ball 4 is in the open state, the pipe structure portion 7 on the left side of the paper with respect to the ball 4 is in communication with the pipe structure portion 7 on the right side of the paper, and fluid can flow from the left side of the paper to the right side, for example. Note that the operation portion 9 (for example, the hand wheel 99) can be provided with an arrow indicating the direction of rotation of the hand wheel 99 and / or a mark indicating which state the ball is currently in.

[0029] The valve 10 of the present embodiment has the flow path P in the X-axis direction (first direction) provided at the lower end portion and is configured to have the ball 4 ( Figure 2 ) disposed in the middle of the flow path P. The axis direction of the valve stem 3 is parallel to the vertical direction (Z direction), and the ball 4 is connected at the lower end and the bonnet 2 is connected at the upper end.

[0030] As shown in Figure 1 , the valve 10 has a cylindrical appearance in which the valve body 1 is longer in the vertical direction (second direction) and the diameter is almost constant from the lower end portion to the upper end portion. In this regard, as shown in Figure 2 , although the valve stem 3 is a thin rod, the inner diameter of the portion of the valve body 1 that surrounds the valve stem 3 is much larger than the diameter of the valve stem 3. The reason for this will be described later.

[0031] <Valve Body 1>

[0032] The valve body 1 is a welded structure in which the valve spool is housed in the lower portion of the housing space and the valve stem connected to the valve spool is housed in the upper portion. Specifically, the valve body 1 has a valve spool housing portion 5 that houses the ball 4 ( Figure 2 ), a valve stem housing portion 6 that houses the valve stem 3 ( Figure 2 ), and a pipe structure portion 7 that extends in the horizontal direction from the side surface of the valve spool housing portion 5.

[0033] (Valve Spool Housing Portion 5)

[0034] The valve core housing portion 5 has a hollow central region 51 in which the ball 4 is rotatably disposed.

[0035] The central region 51 has an inner surface that contacts the lower surface of the ball 4, and a recessed portion 51a is provided in the inner surface for fitting a protruding portion 4b provided on the lower surface of the ball 4. In addition, a communication port 6a is provided in the upper portion of the central region 51 to communicate the hollow portion of the central region 51 with the interior space of the valve stem housing portion 6.

[0036] The valve core housing portion 5 also has an end region 52 between the central region 51 and the pipe structure portion 7 that communicates the hollow portion of the central region 51 with the pipe interior of the pipe structure portion 7. The end region 52 has a circular tube-shaped inner periphery that has a pipe axis extending in the paper left-right direction, and a support mechanism 80 is provided in the inner periphery to support the ball 4 from the side. The support mechanism 80 is described later. Figure 2

[0037] (Ball 4)

[0038] Here, the ball 4 is described. The ball 4 is a spherical body with a flow path 4a formed therethrough. The diameter of the flow path 4a is equal to the pipe diameter (length in the Z-axis direction) of the pipe structure portion 7 extending in the horizontal direction (X-axis direction) from the side of the valve core housing portion 5. In this way, the diameter of the flow path 4a of the ball 4 is the same as the pipe diameter of the pipe structure portion 7, so the ball 4 does not become an obstacle to the flow of fluid in the flow path formed by the pipe structure portion 7, and thus large-volume fluid flow can be performed well at high pressure.

[0039] The ball 4 has an upper surface connected to the valve stem 3 and a lower surface on the opposite side from the upper surface, and a protruding portion 4b is provided in the lower surface that protrudes downward. In addition, the diameter of the tip portion (protruding end 4b') of the protruding portion 4b on the side farther from the valve stem 3 is smaller than the diameter of the portion (base portion) on the side closer to the valve stem 3. By making the protruding end 4b' small in this way, the protruding end 4b' of the protruding portion 4b functions as a guide for fitting into the recessed portion 51a of the valve core housing portion 5, so the fitting operation of the ball 4 during valve assembly is easy.

[0040] (Valve stem housing portion 6)

[0041] ​The valve stem housing 6 is a tubular structure having a tube axis in the vertical direction (Z direction), and a communication port 6a that communicates with the hollow portion of the central region 51 is provided at the lower end portion thereof. The opening diameter of the communication port 6a in the horizontal direction is larger than the diameter of the ball 4 in the horizontal direction. The upper surface of the ball 4 and the connecting portion of the valve stem 3 are located in the communication port 6a. Further, an upper end opening portion 6b (opening portion) that is larger in diameter than the ball 4 in the horizontal direction is provided at the upper end portion of the valve stem housing 6. Further, the inner diameter of the intermediate portion 6c sandwiched between the lower end portion and the upper end portion of the valve stem housing 6 is also larger than the diameter of the ball 4 in the horizontal direction. Further, as shown in Figure 2 , the inner diameters of the upper end opening portion 6b and the intermediate portion 6c are larger than the communication port 6a. The inner diameter of the intermediate portion 6c can also be uniform in the vertical direction, but as shown in Figure 2 , it can also be tapered toward the end portions at the upper end portion and the lower end portion.

[0042] In this way, by making the inner diameter of the valve stem housing 6 (including the communication port 6a and the upper end opening portion 6b) larger than the diameter of the ball 4 in the horizontal direction, the ball 4 can be lifted together with the valve stem 3 and taken out to the outside of the valve body 1. Thus, maintenance of the ball 4 can be performed. Further, conversely, by lowering the ball 4 from the upper end opening portion 6b into the valve body 1, the ball 4 can be disposed in the valve core housing 5. In this specification, this type in which the valve core is inserted into and extracted from the upper portion of the valve body is referred to as a "top entry (type)".

[0043] Therefore, in consideration of the operability of the top entry, the inner diameter of the intermediate portion 6c is made much larger than the diameter of the ball 4 in the horizontal direction. Further, as will be described later, the intermediate portion 6c is provided with a middle cover 60 that presses the ball 4 from above, and the inner diameter of the intermediate portion 6c is made large in consideration of the form of the arrangement of the middle cover 60. As an example, the valve 10 of the present embodiment has the inner diameter of the intermediate portion 6c set to a length close to the length in the horizontal direction of the valve core housing 5.

[0044] Further, the thickness of the tube wall of the valve stem housing 6 can be made thin, for example, about one-twentieth, with respect to the inner diameter of the valve stem housing 6. This is because the fluid pressure force is not applied to the valve stem housing 6, and thus the internal pressure is not as high as that of the valve core housing 5. As an example, the thickness of the tube wall of the valve stem housing 6 can be set to 4 cm to 7 cm. Further, Figure 2 , the outer diameter of the valve stem housing 6 is substantially equal to the length in the horizontal direction of the valve core housing 5. Therefore, in general, the outer form of the valve 10 can be said to be a cylinder as described above.

[0045] Here, for example, as shown in Figure 3As shown, the valve 10 of the present embodiment can be provided with a vacuum jacket 100 that is hermetically closed on the outside of the valve body 1. By providing the vacuum jacket 100, the liquid hydrogen flowing in the flow path can be kept at an appropriate temperature by the heat insulating effect of the vacuum jacket 100. The vacuum jacket 100 is installed on the flange portion 6d that is provided on the upper end portion of the valve stem housing portion 6 to project laterally, and the valve cover 2 is exposed to the outside of the vacuum jacket 100 in the present embodiment. As described above, the valve 10 is of the top entry type, and thus the vacuum jacket 100 can cover the entire portion except the valve cover 2. Note that the valve 10 of the present embodiment can include the vacuum jacket 100 as a constituent element, or can not include the vacuum jacket 100 as a constituent element. Figure 2 As shown, the valve 10 of the present embodiment can be provided with a vacuum jacket 100 that is hermetically closed on the outside of the valve body 1. By providing the vacuum jacket 100, the liquid hydrogen flowing in the flow path can be kept at an appropriate temperature by the heat insulating effect of the vacuum jacket 100. The vacuum jacket 100 is installed on the flange portion 6d that is provided on the upper end portion of the valve stem housing portion 6 to project laterally, and the valve cover 2 is exposed to the outside of the vacuum jacket 100 in the present embodiment. As described above, the valve 10 is of the top entry type, and thus the vacuum jacket 100 can cover the entire portion except the valve cover 2. Note that the valve 10 of the present embodiment can include the vacuum jacket 100 as a constituent element, or can not include the vacuum jacket 100 as a constituent element.

[0046] (Valve Stem 3)

[0047] Next, the valve stem 3 housed in the valve stem housing portion 6 will be described. The valve stem 3 functions to connect the operation portion 9 and the ball 4 as described above, but in order to distance the components that are susceptible to low temperatures from the ball 4 through which the fluid passes, a so-called long valve stem is used. One of the reasons for this is that the valve 10 of the present embodiment is a top entry type valve for liquid hydrogen. When liquid hydrogen flows through the flow path P, the valve core housing portion 5 including the ball 4 becomes the same temperature as the liquid hydrogen (-253°). On the other hand, the portion of the valve cover 2 is provided with a packing seal 23 that prevents leakage of the fluid from around the axis of the valve stem 3, but if the temperature of the packing seal 23 is too low, the valve stem can not operate normally. In addition, if the operation portion 9 is also too cold, operation failure can occur. Therefore, in the present embodiment, a countermeasure is taken to suppress the temperature drop of these portions by distancing the valve cover 2, the operation portion 9, and the ball 4. Furthermore, a structure is adopted in which these portions are connected by the valve stem 3, and even in the distanced state, the operation of the operation portion 9 is transmitted to the ball 4 located at a remote position.

[0048] The length of the valve stem housing 6 in the vertical direction (Z direction) can be determined by the length of the valve stem 3, which can be determined in accordance with the operability of the valve. For example, if the valve is for a fluid such as liquid hydrogen that is extremely low in temperature, the length of the valve stem 3 can be appropriately determined based on calculated or experimental values within a range in which the coldness or heat of the fluid does not substantially limit the operation of the operation portion of the valve. In addition, the length of the valve stem 3 can be determined by, for example, the material and structure of the valve stem 3 within a range in which the mechanical strength and the like required for operation of the valve core are ensured. For example, if the heat transfer property of the material of the valve stem 3 is low, or if the valve stem 3 is of a porous structure, or if it has a structure such as fins that improves heat dissipation, it is expected that the length of the valve stem 3 will be shorter. The preferred length of the valve stem 3 varies depending on these various conditions, but, for example, in the case where the fluid is liquid hydrogen, it is preferable to set the length of the valve body to a temperature at which the operation portion and the packing (packing seal 23) do not freeze (preferably -20°C to 0°C, more preferably -10°C to 0°C, and particularly preferably about 0°C) and to set the length of the valve stem accordingly.

[0049] Note that in the valve 10 of the present embodiment, even for a valve stem housing 6 that is long and realizes a push-in type, in order to reliably house the ball 4 within the valve core housing 5, in the present embodiment, the middle cover body 60 is attached to the communication port 6a of the valve stem housing 6. Hereinafter, the middle cover body 60 will be described.

[0050] (Middle Cover Body 60)

[0051] The middle cover body 60 is attached to the inner surface of the housing space of the valve body 1 to divide the space on the ball 4 side (valve core housing 5) in the valve body 1 in a liquid-tight or gas-tight manner so that the valve stem 3 can operate. Specifically, the middle cover body 60 is housed in the valve stem housing 6, seals the communication port 6a from the valve stem housing 6 side in a state in which the valve stem 3 penetrates therethrough, divides the housing space of the valve body 1, and houses the ball 4 in the valve core housing 5 so as to be rotatable. The middle cover body 60 has, in order from the side closer to the valve core housing 5, an trunnion plate 61 (first plate) and a valve yoke plate 62 (second plate). In the valve 10 of the present embodiment, in this way, in the valve body 1, the valve core housing 5 and the valve stem housing 6 are divided only by the middle cover body 60, and in particular, only the middle cover body 60 is disposed between the valve core, i.e., the ball 4, and the valve stem housing 6. That is, in the present embodiment, the valve core housing 5 and the middle cover body 60 constitute a so-called valve core box, and the ball 4 is exposed to the valve stem housing 6 if the middle cover body 60 is not present. In addition, the middle cover body 60 is constituted by a plate structure of the trunnion plate 61 and the valve yoke plate 62, and is compactly attached within the valve body 1, and thus the entire valve 10 can also have a compact outer shape.

[0052] The trunnion plate 61 and the valve yoke plate 62 are both circular plate bodies. A through-hole 61a through which the valve stem 3 passes is provided in the center of the trunnion plate 61, and a through-hole 62a through which the valve stem 3 passes is also provided in the center of the valve yoke plate 62.

[0053] Further, a threaded structure is provided on the outer peripheral surface 62b of the valve yoke plate 62, and is screwed with a threaded structure provided on a portion of the inner peripheral surface of the valve stem housing portion 6, so that the valve yoke plate 62 can be fixed at a desired position in the valve stem housing portion 6 by screwing. Note that the portion that is fitted with the middle cover body 60 is the lower end portion of the intermediate portion 6c in the inner peripheral surface of the valve stem housing portion 6, and corresponds to the portion in which the inner diameter is reduced. That is, the thickness of the tube wall of this portion is made thicker than the tube wall of the other portions of the valve stem housing portion 6. Thus, the load in the radial direction accompanying the fitting of the middle cover body 60 can be borne. Note that, instead of being fixed by such a threaded structure, the valve yoke plate 62 can be fixed using, for example, a prescribed fixing unit that is detachable with respect to the valve body 1, such as a bolt, fixed to the valve body 1. In view of the ease of assembly and the like, it is preferable to be screwed with the valve body by a threaded structure.

[0054] On the other hand, the trunnion plate 61 is fitted with the inner peripheral surface of the valve stem housing portion 6, but, unlike the valve yoke plate 62, is not fixed to the valve body 1 using any fixing unit such as screwing. The trunnion plate 61 is fixed in the position shown in the drawing by being pressed toward the ball 4 side by the valve yoke plate 62. Figure 2 This will be further described below. Figure 4 Further, the trunnion plate 61 is fitted with the inner peripheral surface of the valve stem housing portion 6, but, unlike the valve yoke plate 62, is not fixed to the valve body 1 using any fixing unit such as screwing. The trunnion plate 61 is fixed in the position shown in the drawing by being pressed toward the ball 4 side by the valve yoke plate 62.

[0055] Figure 4 is Figure 2 is an enlarged sectional view of the single-dotted-line frame portion B shown in the drawing. In Figure 4 , the vicinity of the ball 4, the trunnion plate 61, and the valve yoke plate 62 is shown enlarged. The trunnion plate 61 is disposed on the upper portion of the ball 4, and the valve yoke plate 62 is disposed thereon. The trunnion plate 61 has a reduced-diameter portion that is fitted with the communication port 6a, and an enlarged-diameter portion that is located on the intermediate portion 6c side compared with the communication port 6a and is larger in diameter than the reduced-diameter portion. Further, the trunnion plate 61 is supported so as not to move further toward the ball 4 side by the lower surface of the step portion between the enlarged-diameter portion and the reduced-diameter portion abutting against the upper surface of the reduced-diameter portion of the communication port 6a on the inner diameter side of the valve body 1. Moreover, the trunnion plate 61 is supported by the reduced-diameter portion of the communication port 6a in this way, so that the surface on the ball 4 side is kept apart from the ball 4 and the valve stem 3, and they do not come into contact with each other. Thus, the trunnion plate 61 does not slide between the ball 4 and the valve stem 3 at the time of opening and closing of the ball 4, and in addition to being able to reduce the opening and closing torque, wear of the ball 4 and the like caused by sliding is prevented.

[0056] Further, the trunnion plate 61 and the valve yoke plate 62 do not contact each other on the opposite faces thereof, but contact via the seal members 69a, 69c. Specifically, the inner periphery of the through-hole 61a of the trunnion plate 61 and the outer peripheral face of the trunnion plate 61 and the inner peripheral face of the valve body 1 (valve stem housing portion 6) are sandwiched by the seal members 69a, 69c, respectively, and the portions are sealed. The valve yoke plate 62 has a protruding portion 62c protruding toward the trunnion plate 61 on the outer peripheral portion thereof, and presses the seal member 69c from above. Further, a grommet member 68 is arranged below the end portion of the through-hole 62a of the valve yoke plate 62, and the grommet member 68 pushes the seal member 69a downward. The seal members 69a, 69c contact each other on tapered faces of the trunnion plate 61, and are pushed downward from above by the valve yoke plate 62 in this state, whereby a wedge-shaped force is generated, and the inner and outer peripheries of the trunnion plate 61 are reliably closed by the seal members 69a, 69c, as a result of which a very high sealability is exerted.

[0057] As described above, the movement of the trunnion plate 61 downward (toward the ball 4) is structurally restricted, but the movement in directions other than this (upward or rotational direction) is possible. For example, the fluid flowing through the flow path 4a is turned around to the position of the trunnion plate 61, and is sealed by the seal members 69a, 69c, but in the case where the fluid pressure rises to exceed the holding force of the seal members 69a, 69c, the trunnion plate 61 is pushed upward. In the present embodiment, thus, the movement of the trunnion plate 61 in a free state substantially not fixed to the valve body 1 upward is restricted by the valve yoke plate 62 fixed to the valve body 1. Also in the present embodiment, the seal (shaft seal) by the seal member 69a around the valve stem 3 and the seal (outer peripheral seal) by the seal member 69c of the outer peripheral portion of the trunnion plate 61 are each a so-called pressure seal structure in which the more the fluid pressure pushes the trunnion plate 61 upward, the more the seal force is increased by the force applied to each seal member 69a, 69c, and thus the sealability can be sufficiently exerted even in a state in which only the outer peripheral portion of the valve yoke plate 62 is fixed.

[0058] Further, the outer ring 67 is sandwiched between the lower face (end portion on the side close to the ball 4) in the trunnion plate 61 and the ball seat 81 of the support mechanism 80 described later.

[0059] By thus mounting the middle cover body 60 to the valve stem housing portion 6, the ball 4 can be reliably housed in the valve core housing portion 5. Also, since the communication port 6a is closed by the middle cover body 60, the case in which the ball 4 is improperly ejected upward can be avoided, and leakage of liquid hydrogen to the valve stem housing portion 6 can be prevented.

[0060] Further, the valve yoke plate 62 is screwed with the threaded structure 6e of the valve stem housing 6, thereby pressing and fixing the trunnion plate 61 to the periphery of the communication port 6a. That is, the trunnion plate 61 is not screwed toward the ball 4 in a manner that the screwing force is transmitted to the ball 4 via the trunnion plate 61. Further, particularly, the trunnion plate 61 and the valve yoke plate 62 do not directly contact each other at the opposing faces thereof, and thus the screwing force of the valve yoke plate 62 is not transmitted to the ball 4 via the trunnion plate 61.

[0061] Further, referring to Figure 3 In the present embodiment, the valve 10 is configured to provide the middle cover 60 of the plate structure in the hollow portion of the valve stem housing 6 (valve body 1), and no structure other than the valve stem 3 is provided between the middle cover 60 and the valve cover 2. Therefore, compared to the case where another structure is provided in the hollow portion, the heat conduction between the ball 4 and the valve cover 2 can be limited to the heat conduction by the valve body 1 and the valve stem 3. Therefore, the heat of the valve cover 2 or the operation portion 9 does not excessively spread to the flow path P through which the liquid hydrogen flows. In contrast, the extremely low temperature of the fluid P does not excessively transmit from the flow path P to the valve cover 2 and the operation portion 9 to cause the above-described problem.

[0062] (Support mechanism 80)

[0063] The support mechanism 80 supports the ball 4 from the side. Hereinafter, the support mechanism 80 will be described using Figure 5 The support mechanism 80 will be described. Figure 5 is Figure 2 is an enlarged sectional view of the frame portion C shown by the single-dot chain line.

[0064] The support mechanism 80 is configured with a ball seat 81, a race 82, and a race retainer gland 83 from the ball 4 side. The race retainer gland 83 is urged to the ball 4 side by a spring 84. A stepped portion 82a is provided on the outer diameter side of the race 82. The outer diameter side of the race retainer gland 83 protrudes to the ball 4 side at the position of the stepped portion 82a of the race 82, and presses the end face of the stepped portion 82a of the race 82 via a seat packing 85. That is, the force of the spring 84 acts in a manner that it is sequentially transmitted to the race retainer gland 83, the seat packing 85, the race 82, and the ball seat 81, and presses the ball seat 81 against the ball 4. By this structure, the ball 4 and the ball seat 81, and the ball seat 81 and the race 82 are tightly adhered to each other, and these portions function as seals to prevent the fluid from leaking to the outside from the flow path. The ball seat 81 is configured of a resin material or the like that is softer than metal. Therefore, the outer diameter side thereof is supported by the outer ring 67 to maintain the shape without being deformed in the case where the fluid pressure is applied. The ball seat 81 and the outer ring 67 are fixed to each other by embedding a C ring 90 into grooves provided on the opposing faces of both.

[0065] <Valve cover 2>

[0066] like Figure 1 and Figure 2 As shown, the valve cover 2 is threaded to the upper end of the valve body 1 (valve stem receiving portion 6) at multiple locations. This threaded fastening closes the upper opening 6b of the valve stem receiving portion 6, and the valve cover 2 can be removed from the valve body 1 (valve stem receiving portion 6) by unscrewing the threaded fasteners. In summary, the valve cover 2 is detachably fixed to the upper end of the valve body 1 (valve stem receiving portion 6).

[0067] The valve cover 2 has a through portion 2a that fixes the upper end of the valve stem 3 through it. Additionally, the upper end of the valve cover 2 has a pressure plate 22 connected to the upper end of the valve stem 3. An operating part 9 is connected to the pressure plate 22.

[0068] The valve cover 2 has a purge valve 21, which purges the fluid in the space (the hollow portion of the valve stem housing 6) divided by the middle cover 60 and the valve cover 2 in the valve body 1. In the case of the valve 10 for liquid hydrogen as in this embodiment, it is undesirable for air to remain in the hollow portion of the valve stem housing 6. Therefore, the air in the hollow portion can be purged during valve assembly by using the purge valve 21. Alternatively, the hollow portion can be made into a vacuum or injected with hydrogen. In the event that liquid hydrogen from the flow path P leaks into the hollow portion and expands, it can also be purged by the purge valve 21 to ensure safety. In short, the fluid purged by the purge valve 21 may include at least one of liquid and gas.

[0069] <Operation Section 9>

[0070] The operating unit 9 has a handwheel 99 ( Figure 1 It can transmit the rotational motion of the handwheel 99 to the valve stem 3. As this transmission mechanism, a well-known operating mechanism can be used.

[0071] As described above, the valve 10 of this embodiment is used as a top-entry type valve for liquid hydrogen. Therefore, it is preferable that the valve core housing 5 (ball 4 and support mechanism 80), valve stem housing 6 (excluding valve stem 3 and middle cover 60), and piping structure 7, which constitute the outer shell elements of the valve body 1, are arranged within the vacuum jacket and do not have any joints other than welding. An integral structure refers to a completely integral structure that does not use other jigs such as bolts or screws for connection, or even if there are joints, multiple parts (components) are joined only by welding. Here, when joining by welding, the valve core housing 5 can be welded to the valve stem housing 6, and the valve core housing 5 can be welded to the piping structure 7, but it is not limited to this. For example, in this embodiment, as Figure 2As shown, welding is performed between the valve element housing portion 5 and the pipe structure portion 7, but the valve stem housing portion 6 is welded from three parts, the lower part of which is implemented by one member in a manner that there is no welded joint between the valve element housing portion 5. In any case, the parts constituting the housing element of the valve body 1 are integrated by welding multiple parts.

[0072] By forming an integrated structure in this way, a valve body 1 can be provided that is highly reliable and does not leak even for liquid hydrogen. In addition, compared to a method of connecting using a jig, there is no need to provide a jig on the outer surface of the valve body 1, and the outer surface can be made into a surface with less irregularities. This contributes to simplifying the inner surface structure of the vacuum jacket 100 described above, and enables good installation of the vacuum jacket.

[0073] In addition, since multiple parts are connected only by welding in this way, the structural strength of the valve body 1 is high. Therefore, a larger flow path can be constituted and a large amount of liquid hydrogen can flow. Regarding the flow rate, it can be appropriately set based on the pipe diameter of the pipe structure portion 7, and the size of the ball 4 and the diameter of the flow path 4a. For example, the valve 10 of the present embodiment can implement the pipe diameter of the pipe structure portion 7 and the diameter of the flow path 4a (the diameter of the first opening portion) with a large diameter of 25 cm or more. For example, the pipe diameter and the diameter can be constituted with about 10 inches to 24 inches (about 25 cm to 65 cm). As shown in the present embodiment, by adopting a ball valve, pressure loss can be reduced, so the same Cv value can be achieved with a smaller diameter compared to other types of valves (stop valves or butterfly valves) used as cryogenic valves. For example, if the ball valve of the present embodiment is 24 inches, the same degree of Cv value as a 36-inch butterfly valve can be achieved.

[0074] Finally, the material of each constituent element will be described. The valve body 1, the ball 4, the trunnion plate 61, the valve yoke plate 62, the outer ring 67, the race 82, the spring 84, and the race cover 83, which are implemented by the integrated structure described above, can be constituted by, for example, stainless steel. In addition, the valve stem 3 can be constituted by heat-resistant steel. In addition, the seal members 69a, 69c can be constituted by graphite. In addition, the ball seat 81 can be constituted by a resin having heat resistance and wear resistance. In addition, the valve cover 2 can be constituted by stainless steel.

[0075] In the assembly of the valve 10 of the present embodiment, the upper portion of the valve stem 3 is held in a state where the valve stem 3 is connected to the ball 4, and the ball 4 is introduced into the valve core housing portion 5 in the valve body 1 from the upper end opening portion 6b. At this time, the support mechanism 80 can be previously provided in the valve core housing portion 5 in the valve body 1, or can be simultaneously introduced into the valve core housing portion 5 along the ball 4. By so doing, when the ball 4 and the support mechanism 80 are housed in the valve core housing portion 5, then the trunnion plate 61 is introduced into the valve body 1 from the upper end opening portion 6b by hanging it with a prescribed fixing tool or the like, and is lowered to the communication port 6a. Then, after the fixing tool of the trunnion plate 61 is removed, the valve yoke plate 62 is similarly introduced into the valve body 1 from the upper end opening portion 6b. Further, the valve yoke plate 62 is rotated in the valve body 1 using a fixing tool, other rotation jig, or the like, so that the screw structure provided to the outer periphery is screwed with the screw structure provided to the inner surface of the valve stem housing portion 6 in the valve body 1. Thereby, the valve yoke plate 62 is fixed to the valve body 1 and presses the trunnion plate 61 toward the ball 4. After the ball 4, the support mechanism 80, and the middle cover body 60 are thus housed in the valve body 1, the valve cover 2 is attached to the upper end portion of the valve body 1, and the operation portion 9 or the like is provided, whereby the assembly of the valve 10 is completed. By this assembly method, the valve 10 of the present embodiment can be easily assembled even though the valve body 1 is a cylindrical shape that is long in the vertical direction, and further, the extraction of the components in the valve body at the time of maintenance or the like becomes easy.

[0076] (Variants)

[0077] (Variant 1)

[0078] In the above-described embodiment, a globe valve is constituted, but one aspect of the present application is not limited to this. For example, pop-in type valves that constitute stop valves and butterfly valves are also included in one aspect of the present application. As the valve of the present application, a valve core having a shape in which the diameter of at least one direction is larger than the diameter of the valve stem that supports the valve core (i.e., exceeds the diameter of the valve stem) can effectively exert the effects in the structure of the present application. In addition, the present application is particularly suitable for globe valves and butterfly valves that switch between opening and closing by rotating the valve core by 90° in conjunction with the rotation of the valve stem.

[0079] Note that in the above-described embodiment, the pipe structure portion 7 on the upstream side and the pipe structure portion 7 on the downstream side sandwiching the ball 4 are provided as opening portions of the flow path, and the flow path extends in one direction. However, not only this form in which the flow path opens in two directions, but also a form in which the flow path opens in three or more directions can be adopted.

[0080] (Variant 2)

[0081] Instead of the above-described embodiment, the valve cover 2 can be constituted of a heat insulating material, or a heat insulator can be attached to the valve cover 2. These aspects are also included in one aspect of the present application.

[0082] (Variant 3)

[0083] In the above-described embodiment, the valve stem housing 6 is a hollow portion, but a heat insulator can be provided in the hollow portion. These aspects are also included in one aspect of the present application.

[0084] (Modified Example 4)

[0085] In the above-described embodiment, the grommet 60 is provided with the trunnion plate 61, the valve yoke plate 62, the seal members 69a, 69c, and the gland member 68, but other structures can also be included. For example, a sheet-like thrust washer can be provided between the trunnion plate 61 and the valve yoke plate 62 and / or between the trunnion plate 61 and the ball 4. In addition, a curl hair ring can be provided between the inner peripheral surface of the through-hole 62a of the valve yoke plate 62 and the outer peripheral surface of the valve stem 3. In addition, a sheet-like thrust washer can also be provided between the gland member 68 and the valve yoke plate 62.

[0086] (Modified Example 5)

[0087] In the above-described embodiment, a valve of a top entry type in which the extension direction of the valve stem 3 is set to be parallel to the vertical direction is described, but one aspect of the present application is not limited to this, and a structure in which the extension direction (axial direction) of the valve stem 3 is inclined with respect to the vertical direction can also be used.

[0088] (Modified Example 6)

[0089] In the above-described embodiment, the valve body 1 is a welded structure, but the plurality of parts can be connected by a method other than welding. Note that, in this modified example, in a case where the valve stem housing 6 is configured by connecting a plurality of tubular parts using a jig such as a bolt, the length of the valve stem housing 6 (also referred to as the length of the valve body 1) can be adjusted by changing the number of parts connected.

[0090] [Embodiment 2]

[0091] Other embodiments of the present application will be described below. Note that, for convenience of explanation, components having the same function as the components described in the above-described embodiment are attached with the same reference numerals and the description thereof will not be repeated.

[0092] In the above-described Embodiment 1, the grommet 60 is fixed to the valve stem housing 6 by screwing the threaded structure provided in the outer peripheral surface 62b of the valve yoke plate 62 to the threaded structure 6e of the valve stem housing 6 of the valve body 1. Figure 4). However, the fixing method of the middle cover 60 is not limited to this, and for example, the fixing method using a bolt as described above can also be used. Therefore, the following description is given in the form of the fixing method using a bolt. Note that the following description only describes the points different from those of the above-described embodiment 1. The following description of the points not described below is the same as that described in the above-described embodiment 1.

[0093] Figure 6 is an enlarged sectional view taken around the fixing portion of the middle cover 60 and the valve stem housing portion 6. In the present embodiment, the outer peripheral surface of the valve yoke plate 62 and the inner peripheral surface of the valve stem housing portion 6 opposite thereto are not provided with a threaded structure, and the middle cover 60 is fixed to the valve stem housing portion 6 using a bolt 200 (fixing unit).

[0094] Specifically, as shown in Figure 6 , a bolt through-hole 62d is provided in the valve yoke plate 62, and a bolt through-hole 61d is provided in the trunnion plate 61, and the bolt 200 is inserted through these through-holes. The bolt 200 is further inserted into and fixed to a bolt recess 6g provided in the upper surface of a reduced diameter portion 6f, which is a portion in which the inner diameter of the communication port 6a provided in the lower end portion of the intermediate portion 6c of the valve stem housing portion 6 is reduced.

[0095] Here, a threaded cutting is provided in the tip end portion 200a of the bolt 200. The tip end portion 200a is screwed with a threaded cutting provided in the inner peripheral surface of the bolt recess 6g. By screwing in this way, the valve yoke plate 62 can be fixed to the valve stem housing portion 6 of the valve body 1.

[0096] The bolt 200 is further provided with a groove in the enlarged head portion 200b. The lower surface of the enlarged head portion 200b is configured to be caught in the bolt through-hole 62d of the valve yoke plate 62. Therefore, the bolt through-hole 62d has an enlarged counterbore portion on the side of the upper end opening portion 6b of the valve stem housing portion 6. In the example shown in Figure 6 , the enlarged head portion 200b of the bolt 200 is configured to be completely buried in the bolt through-hole 62d.

[0097] As in Embodiment 1 described above, in the present embodiment, the trunnion plate 61 is not directly joined to the valve yoke plate 62 either, but a seal member 69a, 69b is interposed therebetween. In addition, the inner peripheral surface of the bolt through-hole 61d of the trunnion plate 61 is configured in a structure corresponding to the portion 200c of the bolt 200 that does not have a thread cut, and a slight gap is provided therebetween. Therefore, in a state where the bolt 200 is inserted to a prescribed position and the trunnion plate 61 is closed to the communication port 6a via the valve yoke plate 62, as in the trunnion plate 61 of Embodiment 1 described above, the trunnion plate 61 is in a form that is slightly pushed upward by the rise in fluid pressure. Thus, even in the case of fixation using the bolt 200 as shown in the present embodiment, the sealing effect due to the air pressure sealing structure that results from the upward pushing of the trunnion plate 61 by the fluid pressure is easily exerted.

[0098] The positions at which the fixation using such a bolt 200 is performed are provided at a plurality of positions in the circumferential direction centered on the valve stem 3 (two positions are illustrated in Figure 6 FIG. 6).

[0099] The tightening of the bolt 200 is performed by inserting a hexagonal wrench or the like from the upper end opening 6b side of the valve stem housing 6 and inserting the slot of the enlarged diameter head 200b.

[0100] In Embodiment 1 described above, in order to screw the threaded structure provided to the outer peripheral surface 62b of the valve yoke plate 62 to the threaded structure of the valve body 1, it is necessary to introduce into the valve stem housing 6 while maintaining the valve yoke plate 62 in a horizontal state, etc., it is necessary to finely adjust the position of the valve yoke plate 62, and sometimes time is required. In this regard, according to the present embodiment, by adopting the fixation method of the bolt, it is relatively easy to align the positions of the trunnion plate 61 and the valve yoke plate 62 inside the valve stem housing 6, and the work efficiency is improved. In addition, for the same reason, it is easy to detach the trunnion plate 61 and the valve yoke plate 62, and therefore, it is also a favorable structure when maintenance such as replacement of the ball seat 81 is performed, for example.

[0101] 〔Embodiment 3〕

[0102] Another fixation method of the cover body 60 is described. Figure 7 and Figure 8 is described.

[0103] Figure 7is an enlarged sectional view centered on the fixed portion of the middle cover 60 and the valve stem housing portion 6 of the valve body 1. As with the above-described embodiment 2, this embodiment also does not have a threaded structure on the outer peripheral surface of the valve yoke plate 62 and the inner peripheral surface of the valve stem housing portion 6 opposite thereto. In this embodiment, the valve yoke plate 62 and the trunnion plate 61 are integrated by the plate connecting bolt 300, which is different from the above-described embodiment 2. In addition, the stopper portion 500 (fixing unit) for pressing and fixing the middle cover 60 to the communication port 6a is provided on the valve yoke plate 62 side, which is different from the above-described embodiment 2.

[0104] Specifically, as shown in Figure 7 the plate connecting bolt 300 penetrates the connecting through-hole 62e provided in the valve yoke plate 62 and further is inserted into the connecting recess 61e provided in the upper surface of the trunnion plate 61.

[0105] The plate connecting bolt 300 can use a so-called stud bolt having a cutting thread at both ends 300a, 300b and no cutting thread at the middle portion 300c. One end 300a provided with a cutting thread is screwed with a cutting thread provided on the inner peripheral surface of the connecting recess 61e. The other end 300b provided with a cutting thread protrudes to the upper surface side of the valve yoke plate 62 and a nut 400 is screwed therewith. In this way, by screwing the nut 400 and the plate connecting bolt 300, the valve yoke plate 62 is pressed and fixed to the trunnion plate 61. In this embodiment, the bolt fixation by the plate connecting bolt 300 is provided at a plurality of positions (three positions are illustrated in Figure 7 the middle) along the circumferential direction centered on the through-hole 62a through which the valve stem 3 penetrates.

[0106] Here, as with the above-described embodiment, in this embodiment, the trunnion plate 61 and the valve yoke plate 62 are not directly joined but are integrated by the sealing members 69a, 69b interposed therebetween by the plate connecting bolt 300. Therefore, in this embodiment, in the state where the stopper portion 500 is not provided, the trunnion plate 61 and the valve yoke plate 62 can move up and down within the valve stem housing portion 6. In other words, the stopper portion 500 suppresses this up and down movement and a form in which the communication port 6a is closed by the trunnion plate 61 and the valve yoke plate 62 is achieved. In addition, the connecting through-hole 62e in the valve yoke plate 62 is provided so as to have a slight gap with the bolt 300, whereby the up and down movement of the trunnion plate 61 with respect to the valve yoke plate 62 is not restricted and can move to the valve yoke plate 62 side in the case where fluid pressure is applied. Thus, even in the case where the integration of the two plates 61, 62 by the bolt 300 is performed as in this embodiment, it is easy to exert the sealing effect by the air pressure sealing structure due to the upward pressing of the trunnion plate 61 by the fluid pressure.

[0107] As shown in Figure 8As shown, the limit portion 500 is a rod-shaped support body having one end connected to the upper surface of the valve yoke plate 62 and the other end connected to the lower surface of the valve cover 2. The limit portion 500 has a prescribed length, and in a state where the valve cover 2 closes the upper end opening portion 6b of the valve stem housing portion 6, the valve yoke plate 62 is fixed at a prescribed position of the valve stem housing portion 6. As with the plate connecting bolt 300, the limit portion 500 is provided at a plurality of positions along the circumferential direction of the through-hole 62a through which the valve stem 3 passes (two positions are illustrated in Figure 7 , and three positions are illustrated in Figure 8 ). Note that recesses or the like for receiving the limit portion 500 can also be provided on the valve yoke plate 62 and the valve cover 2. The limit portion 500 can be a single body, but can also be a structure fixed to the valve cover 2 or the valve yoke plate 62.

[0108] According to the present embodiment, as with the above-described embodiment 2, compared with embodiment 1, the screwing between the valve yoke plate 62 and the valve stem housing portion 6 is not required, and in this regard, work efficiency can be improved. Furthermore, according to the present embodiment, the trunnion plate 61 and the valve yoke plate 62 can be fixed in a unit after being disposed, and the limit portion 500 can be provided on the valve stem housing portion 6. Therefore, it is easy to interpose the seal members 69a, 69b between the trunnion plate 61 and the valve yoke plate 62, and other than this, the valve yoke plate 62 does not need to be fixed to the valve body, and after the valve yoke plate 62 is disposed, fixing using the limit portion 500 is performed, so it is easy to align the positions of the respective plates 61, 62 with respect to the valve body, and compared with embodiment 2, work efficiency for disposing the trunnion plate 61 and the valve yoke plate 62 on the valve stem housing portion 6 can be improved.

[0109] 〔Embodiment 4〕

[0110] Other embodiments of the present application will be described below. For example, in each of the above-described embodiments, the valve yoke plate 62 is fixed to the valve body using screwing of the outer peripheral portion or fixing using a bolt, but is not limited thereto, and for example, the valve yoke plate 62 and the valve body 1 can be fixed by a bayonet structure. Also, an integral plate is used as the trunnion plate 61, but a split structure in which a member around the valve stem 3 and a member on the outer peripheral side thereof are combined to become one plate can also be used. In this case, the shaft seal by the seal member 69a and the outer peripheral seal by the seal member 69c of the trunnion plate 61 are respectively constituted by separate members, so it is easy to respectively obtain better sealability.

[0111] 〔Summary〕

[0112] The valve 10 of Aspect 1 of the present application has: a valve body 1 that constitutes a flow path of a fluid, and has a plurality of first opening portions (pipe structure portions 7) for allowing the fluid to flow therethrough, and second opening portions (upper end opening portions 6b) that open in a direction (Z-axis direction) intersecting with a direction (X-axis direction) in which the plurality of first opening portions are directed, and that allow a valve element (ball 4) to pass therethrough; the valve element (ball 4) that is housed in the valve body via the second opening portions, and that can open and close the flow path P of the fluid; a valve stem 3 that is connected to the valve element, and that extends to a position further outside than the second opening portions; a valve cover 2 that seals the second opening portions in a manner allowing the valve stem 3 to operate; and a middle cover body that divides a space in the valve body 1 into a space on the valve cover side and a space on the valve element side in a manner allowing the valve stem 3 to operate and in a liquid-tight or gas-tight manner.

[0113] According to the structure of Aspect 1 described above, the space in the valve body is divided into the space on the valve cover 2 side and the space on the valve element (ball 4) side in a liquid-tight or gas-tight manner by the middle cover body 60, and the valve element can be housed in a housing position in the valve body 1. Thus, the valve stem 3 can be long, and the valve element and the valve cover 2 can be distantly separated from each other, and even if an extremely low temperature fluid such as liquid hydrogen is used as the fluid, the temperature of the cooled valve element is difficult to be transmitted to the operation portion 9 and the like. In any case, by such a simple structure of lengthening the valve stem 3, a valve 10 that makes it difficult for the heat of the fluid to be transmitted to the valve cover 2 side can be provided. Therefore, an increase in manufacturing cost and maintenance cost can be suppressed, and a valve 10 that can be used for an extremely low temperature fluid can be realized.

[0114] Further, according to the structure of Aspect 1 described above, a top entry type in which the valve element is extracted from the second opening portions along the axial direction of the valve stem 3 connected to the valve element can be realized.

[0115] Further, the valve of Aspect 2 of the present application can be, in Aspect 1 described above, the middle cover body 60 has a first plate (trunnion plate 61) and a second plate (valve yoke plate 62) in order from the side closer to the valve element, the second plate is fixed to the valve body by a fixing unit, the first plate is not fixed with respect to the valve body, and movement of the first plate to the space on the valve cover side is restricted by fixing the second plate to the valve body.

[0116] Further, the valve of Aspect 3 of the present application can be, in Aspect 2 described above, a threaded structure is provided on the outer peripheral surface of the second plate, the threaded structure is screwed with a threaded structure 6e provided on the inner peripheral surface of the valve body 1, and the first plate is pressed toward the valve element side by screwing the second plate with the valve body.

[0117] According to the structure of the above-described aspect 3, the second plate presses the first plate toward the spool side. That is, the first plate is not in a form of being screwed into the spool in conjunction with the screwing of the second plate. Therefore, it is possible to not transmit the screwing force of the second plate to the spool via the first plate.

[0118] Further, the valve of aspect 4 of the present application can be the valve of the above-described aspect 2, wherein a through-hole for a bolt is provided in each of the second plate and the first plate, a bolt as the fixing unit passes through the through-holes for the bolt of the second plate and the first plate and fixes the tip end side of the bolt to the valve body, and the other end side of the bolt abuts against the second plate, whereby the movement of the second plate toward the space of the bonnet side is restricted.

[0119] Further, the valve of aspect 5 of the present application can be the valve of the above-described aspects 2 to 4, wherein the first plate and the second plate are in contact via a sealing member 69a, 69c, the second plate presses the sealing member 69a, 69c toward the first plate, and the sealing member is pressed by the second plate to seal between the first plate and the inner peripheral surface of the valve body and press the first plate toward the spool side.

[0120] According to the structure of the above-described aspect 5, the first plate and the second plate are not in direct contact, and therefore it is possible to not transmit the screwing force of the second plate to the spool via the first plate. Further, the first plate is in a so-called floating state and is not in a form of being directly linked to the valve body, but by providing the sealing member 69a, 69c, it is possible to prevent the fluid from leaking from the flow path to the valve rod housing portion.

[0121] Further, the valve of aspect 6 of the present application can be the valve of the above-described aspect 1, wherein the middle cover body has the first plate and the second plate in this order from the side close to the spool, the movement of the second plate toward the space of the bonnet side is restricted by a stopper 500 connected to the lower surface of the bonnet and the upper surface of the second plate, the first plate is not fixed with respect to the valve body, and the movement of the first plate toward the space of the bonnet side is restricted by the second plate.

[0122] Further, the valve of aspect 7 of the present application can be the valve of the above-described aspects 1 to 6, wherein a convex portion 4b is provided on the spool at a position on the side opposite to the valve rod, a recessed portion 51a into which the convex portion 4b is fitted is provided in the valve body 1, and the diameter of the protruding tip end portion of the convex portion 4b is smaller than the diameter of the base portion.

[0123] According to the structure of the above-described aspect 7, the valve core can be fixed to the valve body 1 by fitting the protruding portion 4b of the valve core into the recessed portion 51a of the valve body 1. Further, according to the structure, the protruding end of the protruding portion 4b of the valve core is smaller in diameter than the base of the protrusion. Thus, the protruding end of the protruding portion 4b functions as a guide for fitting into the recessed portion 51a. The valve body of the valve of one embodiment of the present application can have a relatively long valve rod receiving portion that receives a long valve rod. Even in this case, if the protruding portion 4b has a guide function, the valve core can be easily fixed at the time of valve assembly.

[0124] Further, the valve of aspect 8 of the present application can be the valve of any one of aspects 1 to 7 described above, wherein the valve cover 2 is further provided with a purge valve 21 that purges gas in a hollow portion of the valve body 1 that receives the valve rod 3.

[0125] In the case of a valve for liquid hydrogen, it is undesirable for air to remain in the hollow portion of the valve rod receiving portion. In this regard, according to the structure of aspect 8 described above, air in the hollow portion can be purged at the time of valve assembly. Further, the hollow portion can be made vacuum or hydrogen can be injected. Further, in the event that liquid hydrogen from the flow path leaks into the hollow portion and expands, safety can be ensured by purging with the purge valve 21.

[0126] Further, the valve of aspect 9 of the present application can be the valve of any one of aspects 1 to 8 described above, wherein the valve core is a ball 4 of a ball valve.

[0127] According to the structure of aspect 9 described above, by making the diameter of the flow path of the ball valve coincide with the pipe diameter of the pipe structure portion 7, it is possible to make the flow path of the pipe structure portion 7 free of obstacles due to the valve core, and it is possible to make a large volume of fluid flow well at high pressure. Further, it is possible to house the ball 4 of such a ball valve in a valve body 1 that is only slightly larger in diameter than the ball 4, and by dividing the space in the valve body 1 into a valve core side space and a valve cover side space by the middle cover body 60 that is fixed to the inner peripheral surface of the valve body 1, the overall shape can also be compact.

[0128] Further, the valve of aspect 10 of the present application can be the valve of any one of aspects 1 to 9 described above, wherein the valve body 1 is a one-piece valve body that does not have a joint portion formed by means other than welding.

[0129] According to the structure of aspect 10 described above, it is possible to apply to a valve for liquid hydrogen.

[0130] Further, the valve of aspect 11 of the present application can be the valve of any one of aspects 1 to 10 described above, wherein the valve body further has a vacuum jacket that is hermetically sealed on the outside.

[0131] According to the structure of the above-described aspect 11, in the case where the fluid is low-temperature such as liquid hydrogen, the fluid can be kept at low-temperature, and a valve 10 with high reliability can be provided.

[0132] Further, the valve of aspect 12 of the present application can be one in which the caliber of the first opening portion is 25 cm to 65 cm in the above-described aspects 1 to 11.

[0133] According to the structure of the above-described aspect 12, a valve that can be applied to a flow path with a larger caliber can be realized.

[0134] The present application is not limited to the above-described embodiments and modifications, and various changes can be made within the scope of the claims, and embodiments obtained by appropriately combining the disclosed technical means in each of the embodiments and modifications are also included in the technical scope of the present application.

[0135] BRIEF DESCRIPTION OF DRAWINGS

[0136] 1: valve body

[0137] 2: valve cover

[0138] 3: valve stem

[0139] 4: ball (valve element) (ball of ball element)

[0140] 4a: flow path

[0141] 4b: convex portion

[0142] 5: valve element housing portion

[0143] 6: valve stem housing portion

[0144] 6b: upper end opening portion

[0145] 6d: flange portion

[0146] 6e: threaded structure

[0147] 7: pipe structure portion

[0148] 9: operation portion

[0149] 10: valve

[0150] 21: purge valve

[0151] 51a: recessed portion

[0152] 60: middle cover body

[0153] 61: trunnion plate (first plate)

[0154] 62: valve yoke plate (second plate)

[0155] 62b: outer peripheral surface

[0156] 62c: protrusion

[0157] 69a, 69c: seal member

[0158] 80: support mechanism

[0159] 99: hand wheel

[0160] 100: vacuum jacket

Claims

1. A valve, characterized in that has: a valve body having a plurality of first opening portions for allowing fluid to pass therethrough and second opening portions which open in a direction intersecting with a direction in which the plurality of first opening portions face and through which a valve spool can pass; a valve spool accommodated in the valve body via the second opening portions and capable of opening and closing a fluid passage; a valve stem connected to the valve spool and extending to a position further outward than the second opening portions; a valve cover sealing the second opening portions in a manner allowing the valve stem to operate; and a middle cover body dividing a space in the valve body into a space on the valve cover side and a space on the valve spool side in a manner allowing the valve stem to operate and in a liquid-tight or air-tight manner, the valve body has a valve spool accommodating portion accommodating the valve spool and a valve stem accommodating portion accommodating the valve stem, a communication port communicating with a hollow portion of the valve spool accommodating portion is provided at a lower end portion of the valve stem accommodating portion, the middle cover body has a first plate and a second plate in order from a side close to the valve spool, both the first plate and the second plate are located at the communication port of the lower end portion of the valve stem accommodating portion, the second plate is fixed to the valve body by a fixing unit, the first plate is not fixed with respect to the valve body and movement of the first plate to the space on the valve cover side is restricted by the second plate being fixed to the valve body.

2. The valve according to claim 1, wherein a threaded structure is provided on an outer peripheral surface of the second plate and is screwed with a threaded structure provided on an inner peripheral surface of the valve body, the first plate is pressed toward the valve spool side by screwing the second plate with the valve body.

3. The valve according to claim 1, wherein the second plate and the first plate are each provided with a bolt through hole, a bolt passes through the bolt through hole of the second plate and the bolt through hole of the first plate, the tip side of the bolt is fixed to the valve body, and the other end side of the bolt abuts against the second plate, whereby movement of the second plate to the space on the valve cover side is restricted.

4. The valve according to any one of claims 1 to 3, wherein the first plate and the second plate contact via a sealing member, the second plate presses the sealing member toward the first plate, the sealing member is pressed by the second plate, closes between the first plate and the inner peripheral surface of the valve body, and presses the first plate toward the valve spool side.

5. The valve according to claim 1, wherein the middle cover body has a first plate and a second plate in order from a side close to the valve spool, movement of the second plate to the space on the valve cover side is restricted by a stopper portion connected to a lower surface of the valve cover and an upper surface of the second plate, the first plate is not fixed with respect to the valve body and movement of the first plate to the space on the valve cover side is restricted by the second plate.

6. The valve according to any one of claims 1 to 3, wherein a protrusion is provided in the valve spool at a position on a side opposite to the valve stem, A recess into which the convex portion is fitted is provided in the valve body, In the convex portion, the diameter of the tip portion protruding is smaller than the diameter of the base portion.

7. The valve according to any one of claims 1 to 3, wherein The valve cover further has a purge valve that purges fluid in a space in the valve body partitioned by the middle cover body and the valve cover.

8. The valve according to any one of claims 1 to 3, wherein The valve core is a ball of a ball valve.

9. The valve according to any one of claims 1 to 3, wherein The valve body is a one-piece valve body that does not have a joint formed by means other than welding.

10. The valve according to any one of claims 1 to 3, wherein A vacuum jacket that is hermetically closed is further provided on the outside of the valve body.

11. The valve according to any one of claims 1 to 3, wherein The caliber of the first opening portion is 25 cm to 65 cm.

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