Two-way ball valve

Abstract

To provide a two-way ball valve capable of reducing the load applied to a sealing member when reducing operating torque for switching a valve body from a closed state to an open state.SOLUTION: A two-way ball valve 100 comprises: a body 1 including a valve body 2, a valve body housing part 10, and two flow passages 11, two seat rings 4, two seal members 5, and two fluid passing parts 6. Each fluid passing part 6, when in a closed state and when a pressure in a primary-side flow passage 11 is higher than that in a secondary-side flow passage 11, assumes a communication state in which a primary-side seal member 5 is moved within a seal housing space 8 toward the valve body 2 along a pressurizing direction at closure, thereby allowing communication between the primary-side flow passage 11 and the valve body housing part 10 and reducing a pressure difference between the primary-side flow passage 11 and the valve body housing part 10. At the same time, the fluid passing part assumes a shut-off state in which the secondary-side seal member 5 is moved within the seal housing space 8 in a direction opposite to the valve body 2 along the pressurizing direction at closure, thereby blocking communication between the secondary-side flow passage 11 and the valve body housing part 10.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a two-way ball valve. [Background technology]

[0002] BACKGROUND ART Conventionally, two-way ball valves capable of switching between a primary side and a secondary side are known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a two-way ball valve including two flow paths, a ball plug (valve element) disposed between the two flow paths, and a seat ring and an O-ring disposed in each of the two flow paths. The seat ring and the O-ring are a pair disposed on the primary and secondary sides of the ball plug (valve element). The O-ring seals between the flow paths and a ball cavity (valve element housing). When the ball plug is closed and pressure in the primary flow path increases, the two-way ball valve releases the O-ring's seal between the primary flow path and the ball cavity (valve element housing), allowing fluid to flow from the primary flow path into the ball cavity (valve element housing), thereby equalizing the pressure in the primary flow path and the ball cavity (valve element housing).

[0004] Specifically, the space between the seat ring and the valve body, where the O-ring is located, is configured to expand radially outward. When the ball plug is closed and pressure in the primary flow path increases, the O-ring is pressed radially outward by the pressure in the primary flow path, causing the O-ring to elastically deform radially outward, expanding in the radial direction. By creating a gap between the O-ring, the seat ring, and the valve body, fluid flows from the primary flow path into the ball cavity (disk housing), equalizing the pressure in the primary flow path and the pressure in the ball cavity (disk housing). As a result, the ball plug (disk) is released from the load caused by the pressure difference between the primary flow path and the ball cavity (disk housing), reducing the force pressing the ball plug (disk) against the secondary seat ring. In this way, the two-way ball valve reduces the operating torque required to rotate the ball plug (disk) and switch from the closed state to the open state. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-114116 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the two-way ball valve of Patent Document 1, in order to release the O-ring sealing between the primary flow path and the ball cavity (valve body accommodating portion), the O-ring is temporarily elastically deformed radially outward, that is, in the expanding direction, thereby expanding the inner diameter. Therefore, there is a problem in that excessive load is placed on the O-ring when reducing the operating torque for switching the ball plug (valve body) from the closed state to the open state.

[0007] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a two-way ball valve that can reduce the load on the seal member when reducing the operating torque required to switch the valve body from a closed state to an open state. [Means for solving the problem]

[0008] A two-way ball valve according to one aspect of the present invention is a two-way ball valve capable of switching between a primary side and a secondary side, and includes a valve element that switches between a closed state and an open state by rotation, a valve element accommodating section that accommodates the valve element, a body including two flow paths, one on the primary side and one on the secondary side of the valve element accommodating section, two seat rings configured to abut against the valve element and one on the primary side and one on the secondary side of the valve element accommodating section, two seal members that are arranged in a seal accommodating space at the interface between the seat ring and the body and one on the primary side and one on the secondary side of the valve element accommodating section, and a seal member that is disposed in the primary side of the valve element accommodating section. and two fluid passing sections, one on the primary side and one on the secondary side, when the pressure in the primary side flow path is greater than the pressure in the secondary side flow path in the closed state, the fluid passing sections move the primary side seal member toward the valve body inside the seal accommodating space along the closing pressurization direction to enter a communicating state in which the primary side flow path and the valve body accommodating section are in communication with each other, thereby reducing the pressure difference between the primary side flow path and the valve body accommodating section, and move the secondary side seal member toward the side opposite to the valve body inside the seal accommodating space along the closing pressurization direction to enter a blocking state in which the secondary side flow path and the valve body accommodating section are blocked.

[0009] In one aspect of the present invention, the two-way ball valve includes a fluid passage that, when the pressure in the primary flow passage is greater than the pressure in the secondary flow passage in the closed state, moves the primary seal member toward the valve disc within the seal housing space along the closing pressurization direction to establish a communication state between the primary flow passage and the valve disc housing portion, thereby reducing the pressure difference between the primary flow passage and the valve disc housing portion. As a result, when the valve disc is in the closed state and the pressure in the primary flow passage increases, the pressure difference between the primary flow passage and the valve disc housing portion can be reduced by moving the primary seal member toward the valve disc within the seal housing space along the closing pressurization direction, rather than by elastically deforming the seal member in the diameter-expansion direction to expand the inner diameter, as in the conventional method. In other words, the primary flow passage and the valve disc housing portion can be established in communication simply by moving the primary seal member toward the valve disc within the seal housing space while maintaining the inner diameter without expanding the primary seal member. Therefore, since there is no need to expand or contract the seal member as in the conventional case, the load on the seal member can be reduced when the operating torque required to switch the valve disc from the closed state to the open state is reduced. Furthermore, the fluid passing portion is in a blocking state in which it blocks the secondary flow path from the valve disc housing portion when the secondary-side seal member is moved within the seal housing space in the closing pressure direction toward the side opposite the valve disc. This allows the fluid passing portion to prevent fluid from flowing from the valve disc housing portion to the secondary flow path in the closed state.

[0010] In the two-way ball valve according to the above aspect, the seal accommodating space is preferably an annular recess provided on the outer peripheral surface of the seat ring and extending circumferentially of the seat ring, and the fluid passage is recessed in the outer peripheral portion of the seat ring, the inner peripheral portion of the body, or the seal member. With this configuration, simply providing a recessed fluid passage in the outer peripheral portion of the seat ring, the inner peripheral portion of the body, or the seal member can easily reduce the load on the seal member when reducing the operating torque required to switch the valve disc from the closed state to the open state.

[0011] In this case, the fluid passage is preferably formed by a recess or groove provided in the seal accommodating space. With this configuration, the fluid passage can be formed simply by providing a recess or groove in the seal accommodating space, making it easy to form the fluid passage.

[0012] In the configuration in which the fluid passage is formed by a recess or groove provided in the seal accommodating space, the recess is preferably formed in a circular shape when viewed from the direction along the recess direction. With this configuration, the recess serving as the fluid passage is formed in a circular shape, which makes it possible to easily form the fluid passage using a cutting tool such as a drill or an end mill.

[0013] In the above-described configuration in which the seal accommodating space is provided on the outer peripheral surface of the seat ring, the fluid passing portion is preferably recessed into the outer peripheral surface of the seat ring, the annular recessed seal accommodating space having a valve-disc-side inner surface on the valve-disc side, a non-valve-disc-side inner surface on the opposite side from the valve-disc side, and a bottom surface connecting the valve-disc-side inner surface and the non-valve-disc-side inner surface, and the fluid passing portion includes a first recessed passing portion provided on the bottom surface and a second recessed passing portion provided on the valve-disc-side inner surface and communicating with the first passing portion. With this configuration, the primary-side flow path and the valve-disc accommodating space can be communicated with each other via a path along the seal accommodating space by the first recessed passing portion provided on the bottom surface and the second recessed passing portion provided on the valve-disc-side inner surface and communicating with the first passing portion.

[0014] In this case, the first passing portion is preferably disposed offset toward the valve-disc-side inner surface of the bottom surface and is provided so as to reach the valve-disc-side inner surface. With this configuration, when the seal member moves to the side of the bottom surface opposite to the valve-disc-side inner surface, reliable contact between the seal member and the bottom surface is ensured, thereby reliably blocking the passage on the secondary side from the valve-disc accommodating portion.

[0015] In the above-described configuration in which the fluid passing portion includes a first passing portion and a second passing portion, preferably, when the pressure in the primary flow path is greater than the pressure in the secondary flow path in the closed state, the primary seal member moves within the seal accommodating space toward the valve body and is pressed against the valve body-side inner surface, and with the primary seal member pressed against the valve body-side inner surface, the end of the first passing portion opposite the valve body side is open without being blocked by the seal member. With this configuration, fluid in the primary flow path can flow into the first passing portion through the open end. Therefore, the primary flow path and the valve body accommodating portion can be communicated with each other via the open end.

[0016] In the above-described configuration in which the seal accommodating space is provided on the outer peripheral surface of the seat ring, the fluid passing portion is preferably recessed into the inner peripheral portion of the body, and includes, in the closing pressurization direction, an overlapping portion that overlaps with a part of the seal accommodating space, and a non-overlapping portion that is positioned closer to the valve disc than the overlapping portion and does not overlap with the seal accommodating space. With this configuration, the fluid passing portion allows fluid in the primary flow path from the seal accommodating space to flow in through the overlapping portion, and allows fluid to flow out to the interface on the valve disc accommodating portion side through the non-overlapping portion.

[0017] In the above-described configuration in which the seal accommodating space is provided on the outer peripheral surface of the seat ring, the fluid passing portion is preferably a seal groove provided on the outer peripheral side of the seal member, and an adjacent portion of the seal member adjacent to the seal groove on the outer peripheral side of the primary side is deformed by the pressure of the primary-side flow path and moves toward the valve disc, thereby achieving a communicated state, and an adjacent portion of the seal member on the outer peripheral side of the secondary side is deformed by the pressure of the valve disc accommodating portion and moves away from the valve disc, thereby achieving a blocked state. With this configuration, the fluid passing portion can be formed by the seal member, so that the fluid passing portion can be formed without providing a recessed shape for forming the fluid passing portion in the body and the seat ring. [Effects of the Invention]

[0018] According to the present invention, as described above, it is possible to reduce the load applied to the seal member when reducing the operating torque for switching the valve element from the closed state to the open state. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing the overall configuration of a two-way ball valve of a first embodiment, showing a valve body in an open state. FIG. [Figure 2] 1 is an enlarged cross-sectional view showing a main part of the two-way ball valve of the first embodiment, illustrating a valve body in a closed state. FIG. [Figure 3] 1 is a side view showing a seat ring provided with a fluid passage portion of the two-way ball valve of the first embodiment. FIG. [Figure 4] FIG. 3 is an enlarged view of a portion A1 shown in FIG. 2. [Figure 5] 5 is a cross-sectional view taken along line VV in FIG. 4, showing the fluid passing portion, the seat ring, and the seal member disposed in the seal accommodating space. [Figure 6] FIG. 3 is an enlarged view of a portion B1 shown in FIG. [Figure 7] FIG. 10 is an enlarged cross-sectional view showing a main part of a two-way ball valve according to a second embodiment, illustrating the valve body in a closed state. [Figure 8] FIG. 8 is an enlarged view of a portion A2 shown in FIG. [Figure 9] 9 is a cross-sectional view taken along line IX-IX in FIG. 8, illustrating the fluid passing portion, the seat ring, and the seal member disposed in the seal accommodating space. [Figure 10] FIG. 8 is an enlarged view of a portion B2 shown in FIG. [Figure 11] FIG. 10 is an enlarged cross-sectional view showing a main part of the two-way ball valve of the third embodiment, illustrating the valve body in a closed state. [Figure 12] FIG. 10 is a cross-sectional view showing a fluid passage provided in a body of a two-way ball valve of a first modified example. [Figure 13] FIG. 10 is a cross-sectional view showing a fluid passage formed by a groove portion of a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0021] (First embodiment) The configuration of a two-way ball valve 100 according to a first embodiment will be described with reference to FIGS.

[0022] (Overall configuration of two-way ball valve) The two-way ball valve 100 shown in Figures 1 and 2 is capable of controlling the flow of both gas and liquid. The two-way ball valve 100 is configured to be switchable between a primary side, which is the side into which the fluid flows, and a secondary side, which is the side from which the fluid flows out. That is, the two-way ball valve 100 is configured to be switchable between a state in which the X2-direction flow path 11 and the X1-direction flow path 11 serve as the primary side and the secondary side, respectively, and a state in which the X2-direction flow path 11 and the X1-direction flow path 11 serve as the secondary side and the primary side, respectively. Note that the state in which the X2-direction flow path 11 and the X1-direction flow path 11 serve as the primary side and the secondary side, respectively, will be described below.

[0023] A driving means (not shown), such as a pneumatic actuator, an electric motor, or a handle, is provided on the valve stem 3 of the valve element 2 of the two-way ball valve 100. The driving means is configured to generate an operating torque for rotating the valve element 2 via the valve stem 3.

[0024] The flow paths 11 have a circular shape. The primary and secondary flow paths 11 share a common central axis C1 and extend linearly along the central axis C1. In the drawings, the direction in which the central axis C1 extends is indicated as the X direction. Within the X direction, the direction from one flow path 11 to the other flow path 11 is indicated as the X1 direction, and the opposite direction is indicated as the X2 direction. When the flow path 11 on the X2 side and the flow path 11 on the X1 side are the primary side and the secondary side, respectively, the X1 direction coincides with the closing pressurization direction. The "closing pressurization direction" is the direction in which the valve disc 2 is pressurized by the fluid from the primary side to the secondary side when the valve disc 2 is closed. In the drawings, the direction in which the valve stem 3 extends is indicated as the Y direction. The Y direction is (approximately) perpendicular to the X direction. The radial direction of the flow paths 11 is indicated as the R direction.

[0025] The two-way ball valve 100 comprises a body 1 including a valve body accommodating portion 10 and two flow paths 11, a valve body 2, a valve stem 3, two seat rings 4, two seal members 5, and two fluid passages 6.

[0026] The two-way ball valve 100 is a ball valve having a so-called floating structure in which the valve stem 3 is disposed on only one side of the valve element 2, not on both sides. The two flow paths 11, two seat rings 4, two seal members 5, and two fluid passages 6 are each provided as a pair on the primary side and secondary side of the valve element 2.

[0027] In a conventional two-way ball valve, when the pressure in the primary flow path is greater than the pressure in the secondary flow path in the closed state of the valve disc, a relatively large pressing force is applied to the valve disc against the secondary seat ring in the closing pressurization direction, resulting in a relatively large operating torque for rotating the valve disc. In a conventional two-way ball valve, this pressing force is primarily generated by the sum of two pressures: the pressure exerted by the fluid directly pressing the valve disc against the secondary seat ring in the closing pressurization direction, and the pressure exerted by the fluid indirectly pressing the valve disc against the secondary seat ring via the primary seat ring in the closing pressurization direction. The two-way ball valve 100 of the first embodiment is configured to reduce the pressing force exerted by the fluid passage 6 pressing the valve disc 2 against the secondary seat ring 4, thereby reducing the operating torque for the valve disc 2. Details will be described later.

[0028] (Body configuration) As shown in FIGS. 1 and 2, the body 1 includes a main body 12 and a body cap 13 fixed to the main body 12.

[0029] The main body 12 is provided with a flow path 11 and a valve element accommodating portion 10 on the X2 direction side. The main body 12 has a valve element introduction opening 12a for introducing the valve element 2 into the valve element accommodating portion 10. The valve element introduction opening 12a is located at the end of the main body 12 in the X1 direction. The main body 12 is provided with a through-hole extending in the Y direction for arranging the valve stem 3. One seat ring 4 is installed on an inner circumferential surface 14 of the main body 12 (body 1). A step portion 15 is provided on the inner circumferential surface 14 of the main body 12 (body 1) to restrict movement of the one seat ring 4 in the X direction.

[0030] The body cap 13 is provided with a flow path 11 on the X1 direction side. The body cap 13 is fixed to the main body 12 from the X1 direction side with bolts B. The other seat ring 4 is installed on an inner peripheral surface 14 of the body cap 13 (body 1). A step portion 15 that restricts movement of the other seat ring 4 in the X direction is provided on the inner peripheral surface 14 of the body cap 13 (body 1).

[0031] The valve element accommodating portion 10 of the body 1 is a space for accommodating the valve element 2. The valve element accommodating portion 10 is located between the primary and secondary flow paths 11 in the X direction. A flange portion F is provided at each end of the body 1 in the X direction for connecting piping (not shown) to the two-way ball valve 100.

[0032] (Valve body configuration) The valve element 2 is spherical. It has a circular through-hole 20 that extends linearly in a direction perpendicular to the Y direction. For example, the inner diameter of the through-hole 20 is approximately the same as the inner diameter of the primary and secondary flow paths 11. The valve element 2 is configured to switch between a closed state and an open state by rotating it via the valve stem 3. The "closed state" refers to a state in which no fluid flows from the primary flow path 11 to the secondary flow path 11, and the "open state" refers to a state in which fluid flows from the primary flow path 11 to the secondary flow path 11 via the through-hole 20. The valve element 2 switches from the closed state to the open state by rotating it approximately 90 degrees in one direction around the central axis C2 of the valve stem 3. The valve element 2 returns from the open state to the closed state by rotating it approximately 90 degrees in the opposite direction. In the open state, the central axis of the circular through-hole 20 substantially coincides with the central axis C1 of the primary and secondary flow paths 11.

[0033] (Valve stem configuration) The valve stem 3 is a beam member extending linearly in the Y direction. The valve stem 3 is a torque transmission member for transmitting the operating torque of the drive means (not shown) described above to the valve element 2. In detail, the drive means is provided at one end of the valve stem 3 located outside the body 1, and the valve element 2 is fixed to the other end of the valve stem 3 located in the valve element accommodating portion 10 inside the body 1. The valve stem 3 is configured to be rotated together with the valve element 2 within an angular range of approximately 90 degrees around the central axis C2 of the valve stem 3 by the drive means.

[0034] (Seat ring configuration) The seat ring 4 is annular and disposed along the inner circumferential surface 14 of the body 1. The central axis of the seat ring 4 substantially coincides with the central axis C1 of the primary and secondary flow paths 11. An annular disc spring S is provided on the side of the seat ring 4 opposite the valve disc 2 in the X direction. The disc spring S abuts against the seat ring 4. The disc spring S biases the seat ring 4 toward the valve disc 2, pressing the seat ring 4 against the valve disc 2. As a result, the seat ring 4 maintains abutment against the valve disc 2. The seat ring 4 has an annular protrusion 40 at the point where it abuts against the valve disc 2. The annular protrusion 40 functions to seal the gap between the valve disc 2 and the seat ring 4, preventing fluid from passing between them. The inner diameter of the annular protrusion 40 is larger than the inner diameter of the through-hole 20 in the valve disc 2. The seat ring 4 is made of a metal material. The seat ring can also be made of a non-metallic material such as Teflon (registered trademark).

[0035] (Configuration of sealing member) 1 and 2 is disposed (housed) in a seal housing space 8 at an interface 7 between the seat ring 4 and the body 1. A small gap is present at the interface 7 between the seat ring 4 and the body 1, and is filled with a fluid.

[0036] The interface 7 includes a flow path side interface 70 that communicates with the flow path 11, and a valve body side interface 71 that communicates with the valve body accommodating portion 10. In principle, the seal member 5 isolates the flow path side interface 70 (flow path 11) from the valve body side interface 71 (valve body accommodating portion 10) so that no fluid is transferred between the flow path side interface 70 (flow path 11) and the valve body side interface 71 (flow path 11). As an example, the seal member 5 is made of an O-ring.

[0037] The seal accommodating space 8 is an annular recess provided in the outer peripheral surface 41 of the seat ring 4 and extending circumferentially around the seat ring 4. The seal accommodating space 8, which is an annular recess provided in the seat ring 4, has a valve disc-side inner surface 80 on the valve disc 2 side, a non-valve disc-side inner surface 81 on the opposite side from the valve disc 2 side, and a bottom surface 82 connecting the valve disc-side inner surface 80 and the non-valve disc-side inner surface 81.

[0038] The bottom surface 82 is a surface extending in the X direction and is a cylindrical surface with a constant inner diameter centered on the central axis C1. The bottom surface 82 is a surface that is constantly pressed by the seal member 5 from the outside in the radial direction (R direction). The valve body side inner surface 80 and the non-valve body side inner surface 81 are surfaces that extend in a direction perpendicular to the X direction and face each other in the X direction. The outer peripheral end of the valve body side inner surface 80 is connected to the valve body side interface 71. The outer peripheral end of the non-valve body side inner surface 81 is connected to the flow path side interface 70. The seal member 5 is arranged in the seal accommodating space 8 in a compressed state in contact with the bottom surface 82 of the seal accommodating space 8 and the inner peripheral surface 14 of the body 1 in the Y direction.

[0039] When the valve body 2 switches from an open state to a closed state, if the pressure in the primary side flow path 11 is greater than the pressure in the secondary side flow path 11 in the closed state, the seal member 5 moves within the seal accommodating space 8.

[0040] Specifically, when the valve element 2 switches from the open state to the closed state, the primary-side seal member 5 moves in the X1 direction (the pressure direction when closing) toward the valve element 2 within the seal accommodating space 8 and is pressed against the valve element-side inner surface 80. In other words, the primary-side seal member 5 moves in the X direction toward the valve element accommodating portion 10, where the pressure is lower than that of the primary-side flow path 11, and is positioned in the seal accommodating space 8 so as to be biased toward the X1 direction (the pressure direction when closing).

[0041] Furthermore, when the valve disc 2 switches from the open state to the closed state, the secondary-side seal member 5 moves in the seal accommodating space 8 toward the X1 direction (the pressure direction when closing), which is the opposite side to the valve disc 2 side, and is pressed against the non-valve disc-side inner surface 81. In other words, the secondary-side seal member 5 moves in the X direction toward the secondary-side flow path 11, where the pressure is lower than in the valve disc accommodating section 10, and is positioned biased toward the X1 direction (the pressure direction when closing) within the seal accommodating space 8. In other words, when one seal member 5 moves toward the valve disc 2 within the seal accommodating space 8 in the X direction, the other seal member 5 moves toward the opposite side from the valve disc 2 within the seal accommodating space 8. Furthermore, when one seal member 5 moves in the X direction away from the valve disc 2 within the seal accommodating space 8, the other seal member 5 moves toward the valve disc 2 within the seal accommodating space 8.

[0042] (Configuration of fluid passage section) 2 is configured to reduce the pressure difference between the primary flow path 11 and the valve element accommodating portion 10 when the valve element 2 is in the closed state. As a result of reducing the pressure difference, the operating torque required to rotate the valve element 2 is reduced.

[0043] 4 and 5, when the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 with the valve disc 2 in the closed state, the fluid passing section 6 is in a communicating state where the primary-side flow path 11 communicates with the valve disc accommodating section 10 with the primary-side seal member 5 moved within the seal accommodating space 8 toward the valve disc 2 in the closing pressurization direction (X1 direction), thereby reducing the pressure difference between the primary-side flow path 11 and the valve disc accommodating section 10, and is in a blocking state where the secondary-side seal member 5 is moved within the seal accommodating space 8 toward the valve disc 2 in the closing pressurization direction (X1 direction), thereby blocking the secondary-side flow path 11 from the valve disc accommodating section 10. The specific configuration of the fluid passing section 6 will be described below.

[0044] As shown in FIG. 3, the fluid passing portion 6 is recessed into the outer periphery of the seat ring 4. The fluid passing portion 6 is formed by a recess provided in the seal accommodating space 8 of the seat ring 4. When the fluid passing portion 6 is viewed from the outside in the radial direction (direction R), the recess serving as the fluid passing portion 6 is formed in a circular shape when viewed from the direction along the recess direction (viewed from the outside in the radial direction). As an example, the circular recess serving as the fluid passing portion 6 is formed by machining using a cutting tool such as a drill or an end mill. Only one fluid passing portion 6 is provided in the circumferential direction.

[0045] The fluid passing portion 6 includes a concave first passing portion 60 provided on the bottom surface 82 of the seal accommodating space 8. The first passing portion 60 extends in the X direction along the bottom surface 82. The fluid passing portion 6 also includes a semicircular second passing portion 61 that communicates with the first passing portion 60 and is provided on the valve-disc-side inner surface 80 of the seal accommodating space 8. The second passing portion 61 extends in the radial direction (R direction) along the valve-disc-side inner surface 80.

[0046] The first passing portion 60 is provided radially inward (in the R direction) of the bottom surface 82 of the seal accommodating space 8. The seal member 5 arranged in the seal accommodating space 8 is arranged along the bottom surface 82, and is therefore (almost) not arranged inside the first passing portion 60. For this reason, the first passing portion 60 is not blocked by the elastically deformed seal member 5 that enters the interior. As an example, the first passing portion 60 is a conical recess formed by the tip of a cutting tool such as a drill.

[0047] 4, the first passing portion 60 is disposed offset toward the valve disc 2 side of the bottom surface 82 of the seal accommodating space 8 (the valve disc 2 side), and is provided so as to reach the valve disc 2 side inner surface 80 of the seal accommodating space 8. That is, the valve disc 2 side end 60a of the first passing portion 60 is located closer to the valve disc 2 than the valve disc side inner surface 80. The end 60b of the first passing portion 60 on the opposite side from the valve disc 2 side does not reach the non-valve disc side inner surface 81 of the seal accommodating space 8. That is, the end 60b of the first passing portion 60 on the opposite side from the valve disc 2 side is located closer to the valve disc 2 than the non-valve disc side inner surface 81.

[0048] The second passing portion 61 is provided closer to the valve disc 2 than the valve disc-side inner surface 80 of the seal accommodating space 8. The seal member 5 arranged in the seal accommodating space 8 is arranged along the valve disc-side inner surface 80, and is therefore (almost) not arranged inside the second passing portion 61. For this reason, the second passing portion 61 is not blocked by the elastically deformed seal member 5 that penetrates into the interior. As one example, the second passing portion 61 is a recessed portion that is formed by the side surface of a cutting tool such as an end mill so as to extend in the radial direction (R direction), and has an arc shape when viewed from the outside in the radial direction (R direction).

[0049] An inner end 61a in the radial direction (R direction) of the second passing portion 61 is connected to an end 60a on the valve body 2 side of the first passing portion 60. An outer end 61b in the radial direction (R direction) of the second passing portion 61 is connected to the valve body side interface 71. Therefore, the first passing portion 60, the second passing portion 61, the valve body side interface 71, and the valve body accommodating portion 10 are connected so as to be able to transfer fluid between each other at all times.

[0050] An example of the size of the fluid passing portion 6 will be described. The size of the fluid passing portion 6 in the X direction is smaller than the size of the seal accommodating space 8 in the X direction. The size of the fluid passing portion 6 in the X direction is larger than half the size of the seal accommodating space 8 in the X direction. The size of the fluid passing portion 6 in the X direction is larger than the diameter of the cross section of the seal member 5 in a state where it is not elastically deformed. The width of the first passing portion 60 is larger than the width of the second passing portion 61 (see FIG. 5). The size of the first passing portion 60 in the X direction is larger than the size of the second passing portion 61 in the X direction.

[0051] (Details of the communication and blocking states of the fluid passages) The following describes in detail the connected and blocked states of the fluid passage 6. When the pressure in the primary flow path 11 is greater than the pressure in the secondary flow path 11 with the valve element 2 in the closed state, the two-way ball valve 100 operates as follows.

[0052] First, the primary side will be described with reference to Figures 4 and 5. When the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 with the valve disc 2 in the closed state, the primary-side seal member 5 moves toward the valve disc 2 within the seal accommodating space 8 along the closing pressurization direction (X1 direction). The primary-side seal member 5 is then pressed against the valve-disc-side inner surface 80. In other words, the primary-side seal member 5 is positioned biased toward the valve disc 2 within the seal accommodating space 8. As a result, with the primary-side seal member 5 pressed against the valve-disc-side inner surface 80, the end 60b of the first passing portion 60 opposite the valve disc 2 side is open without being blocked by the seal member 5. In other words, an opening OP is formed in the end 60b.

[0053] As a result, the open end 60b of the first passing portion 60 is connected to a space portion 83 of the seal accommodating space 8 that is closer to the X2 direction than the primary-side seal member 5 (the opposite side from the valve body 2 side). This space portion 83 is a space connected to the flow path-side interface 70. Therefore, the first passing portion 60 is connected to the primary-side flow path 11 via the space portion 83 of the seal accommodating space 8 and the flow path-side interface 70. By connecting the first passing portion 60 to the primary-side flow path 11, the fluid passing portion 6 is brought into a communicating state that communicates the primary-side flow path 11 and the valve body accommodating portion 10. As a result, fluid temporarily flows from the primary-side flow path 11 toward the valve body accommodating portion 10 via the fluid passing portion 6, and the pressure difference between the primary-side flow path 11 and the valve body accommodating portion 10 is reduced. In this case, "the pressure difference becomes smaller" is a broad concept that includes both the pressure P1 in the primary flow path 11 and the pressure P2 in the valve body accommodating section 10 being the same (P1 = P2) and being close to each other (P1 ≒ P2).

[0054] Next, the secondary side will be described with reference to FIG. 6 . When the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 when the valve disc 2 is closed, the secondary-side seal member 5 moves in the closed-state pressurization direction (X1 direction) within the seal accommodating space 8 toward the side opposite the valve disc 2. The secondary-side seal member 5 is then pressed against the non-valve-disc-side inner surface 81. In other words, the secondary-side seal member 5 is positioned in the seal accommodating space 8 toward the side opposite the valve disc 2. As a result, with the secondary-side seal member 5 pressed against the non-valve-disc-side inner surface 81, the end 60b of the first passing portion 60 opposite the valve disc 2 is blocked and closed by the seal member 5. That is, the entire circumferential length of the seal member 5 abuts against the bottom surface 82 of the seal accommodating space 8 and the inner circumferential surface 14 of the body 1, and is compressed between the bottom surface 82 and the inner circumferential surface 14. This creates a blocking state in which the secondary-side flow path 11 and the valve disc accommodating portion 10 are blocked. That is, the fluid cannot be transferred between the secondary flow path 11 and the valve body accommodating portion 10.

[0055] The two-way ball valve 100 shown in FIG. 2 has a fluid passage 6 that is in a communicating state on the primary side and in a blocked state on the secondary side, which makes it possible to reduce the operating torque required to rotate the valve element 2 compared to the conventional two-way ball valve described above.

[0056] In detail, when the two-way ball valve 100 is in a communication state on the primary side, the pressure is (almost) equalized between the primary-side flow path 11 and the valve element accommodating portion 10, and therefore the primary-side seal member 5 is not subjected to pressure in the closing pressurization direction (X1 direction) from the fluid. Therefore, the pressure with which the fluid indirectly presses the valve element 2 via the primary-side seal member 5 in the closing pressurization direction becomes (almost) zero.

[0057] As a result, the two-way ball valve 100 is able to reduce the pressing force (a force that causes an increase in the operating torque of the valve disc 2) that presses the valve disc 2 against the secondary-side seal member 5 by having the fluid passing portion 6 in a communicating state on the primary side and in a blocked state on the secondary side. Note that even in this case, as with conventional two-way ball valves, the two-way ball valve 100 is subject to a pressure in which the fluid directly presses the valve disc 2 toward the secondary-side seal member 5 in the closed-time pressurization direction. This is because a pressure difference remains between the secondary-side flow path 11 and the valve disc accommodating portion 10 even if the pressures in the primary-side flow path 11 and the valve disc accommodating portion 10 are (almost) equalized.

[0058] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0059] In the first embodiment, as described above, when the pressure in the primary-side flow path 11 is higher than the pressure in the secondary-side flow path 11 in the closed state, the fluid passing portion 6 is provided, which is in a communicating state in which the primary-side flow path 11 and the valve element accommodating portion 10 are communicated with each other in a state in which the primary-side seal member 5 is moved within the seal accommodating space 8 toward the valve element 2 along the closing-time pressurization direction, thereby reducing the pressure difference between the primary-side flow path 11 and the valve element accommodating portion 10. As a result, when the valve element 2 is in the closed state and the pressure in the primary-side flow path 11 increases, in order to reduce the pressure difference between the primary-side flow path 11 and the valve element accommodating portion 10 by elastically deforming the seal member in the diameter-expansion direction and stretching it so that its inner diameter expands, as in the conventional method, the primary-side seal member 5 can be moved within the seal accommodating space 8 toward the valve element 2 along the closing-time pressurization direction to communicate between the primary-side flow path 11 and the valve element accommodating portion 10. That is, the primary-side flow path 11 and the valve element accommodating portion 10 can be brought into communication with each other simply by moving the primary-side seal member 5 toward the valve element 2 within the seal accommodating space 8 while maintaining its inner diameter without stretching the primary-side seal member 5. This eliminates the need to stretch or contract the seal member as in the past, thereby reducing the load on the seal member 5 when reducing the operating torque required to switch the valve element from the closed state to the open state. Furthermore, the fluid passing portion 6 is in a blocking state in which it blocks the secondary-side flow path 11 and the valve element accommodating portion 10 when the secondary-side seal member 5 is moved within the seal accommodating space 8 toward the opposite side from the valve element 2 along the closing pressurization direction. This allows the fluid passing portion 6 to prevent fluid from flowing from the valve element accommodating portion 10 to the secondary-side flow path 11 in the closed state.

[0060] In the first embodiment, as described above, the seal accommodating space 8 is an annular recess provided in the outer peripheral surface 41 of the seat ring 4 and extending in the circumferential direction of the seat ring 4, and the fluid passing portion 6 is recessed in the outer peripheral portion of the seat ring 4. Thus, simply by providing the recessed fluid passing portion 6 in the outer peripheral portion of the seat ring 4, it is possible to easily reduce the load on the seal member 5 when reducing the operating torque for switching the valve disc 2 from the closed state to the open state.

[0061] In the first embodiment, as described above, the fluid passing portion 6 is formed by a recess or a groove provided in the seal accommodating space 8. This allows the fluid passing portion 6 to be formed simply by providing a recess or a groove in the seal accommodating space 8, making it possible to easily form the fluid passing portion 6.

[0062] In the first embodiment, as described above, the recessed portion is formed in a circular shape when viewed from the direction along the recessed portion direction. As a result, the recessed portion that is the fluid passing portion 6 is formed in a circular shape, and therefore the fluid passing portion 6 can be easily formed using a cutting tool such as a drill or an end mill.

[0063] In the first embodiment, as described above, the fluid passing portion 6 is recessed into the outer circumferential portion of the seat ring 4, and the seal accommodating space 8, which is an annular recess, has a valve-disc-side inner surface 80 on the valve disc 2 side, a non-valve-disc-side inner surface 81 on the opposite side from the valve disc 2 side, and a bottom surface 82 connecting the valve-disc-side inner surface 80 and the non-valve-disc-side inner surface 81. The fluid passing portion 6 includes a recessed first passing portion 60 provided on the bottom surface 82 and a recessed second passing portion 61 provided on the valve disc-side inner surface 80 and communicating with the first passing portion 60. This allows communication between the primary-side flow path 11 and the valve disc accommodating portion 10 via a path along the seal accommodating space 8, via the recessed first passing portion 60 provided on the bottom surface 82 and the recessed second passing portion 61 provided on the valve disc-side inner surface 80 and communicating with the first passing portion 60.

[0064] In the first embodiment, as described above, the first passing portion 60 is disposed on one side of the bottom surface 82, toward the valve body-side inner surface 80, and is provided so as to reach the valve body-side inner surface 80. This ensures reliable contact between the seal member 5 and the bottom surface 82 when the seal member 5 moves on the secondary side to the side of the bottom surface 82 opposite to the valve body-side inner surface 80, thereby reliably blocking the passage 11 on the secondary side from the valve body accommodating portion 10.

[0065] In the first embodiment, as described above, when the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 in the closed state, the primary-side seal member 5 moves within the seal accommodating space 8 toward the valve body 2 and is pressed against the valve-body-side inner surface 80. With the primary-side seal member 5 pressed against the valve-body-side inner surface 80, the end 60a of the first passing portion 60 opposite the valve body 2 side is open without being blocked by the seal member 5. This allows the fluid in the primary-side flow path 11 to flow into the first passing portion 60 from the open end 60a (opening OP). Therefore, the primary-side flow path 11 and the valve body accommodating portion 10 can be communicated with each other via the open end 60a (opening OP).

[0066] (Second embodiment) A second embodiment will be described with reference to Figures 7 to 10. Unlike the first embodiment in which the fluid passing portion 6 is provided in the seat ring 4, which is configured to provide the seal accommodating space 8 for the seal member 5, this second embodiment describes an example in which the fluid passing portion 206 is provided in the body 1 rather than in the seat ring 4, which is configured to provide the seal accommodating space 8 for the seal member 5. Note that in the figures, components similar to those in the first embodiment are denoted by the same reference numerals.

[0067] 7 includes two fluid passages 206, one on the primary side and one on the secondary side of the valve element accommodating portion 10. The two fluid passages 206 are a pair, one on the primary side and one on the secondary side of the valve element 2.

[0068] As shown in FIGS. 8 and 9 , when the pressure in the primary flow path 11 is greater than the pressure in the secondary flow path 11 in the closed state, the fluid passing portion 206 communicates the primary flow path 11 with the valve element housing portion 10 by moving the primary seal member 5 toward the valve element 2 within the seal housing space 8 along the closing pressurization direction (X1 direction), thereby reducing the pressure difference between the primary flow path 11 and the valve element housing portion 10. Also, as shown in FIG. 10 , the fluid passing portion 206 blocks the secondary flow path 11 from the valve element housing portion 10 by moving the secondary seal member 5 along the closing pressurization direction within the seal housing space 8 toward the valve element 2. In FIG. 8 , the seal member 5 before moving along the closing pressurization direction is indicated by a two-dot chain line. The specific configuration of the fluid passing portion 206 will be described below.

[0069] As shown in FIGS. 8 to 10 , the fluid passing portion 206 is recessed in the inner periphery of the body 1. The fluid passing portion 206 is formed by a groove provided in the seal accommodating space 8. The fluid passing portion 206 formed by the groove has a rectangular cross section. The fluid passing portion 206 formed by the groove has a constant width and extends linearly in the X direction. The fluid passing portion 206 includes an overlapping portion 260 that overlaps with a part of the seal accommodating space 8 in the closing pressurization direction (X1 direction). The fluid passing portion 206 also includes a non-overlapping portion 260 that is positioned closer to the valve disc 2 than the overlapping portion 260 and does not overlap with the seal accommodating space 8. An end 261a of the non-overlapping portion 261 on the valve disc 2 side is connected to the step portion 15. The end 261a is connected to the valve disc-side interface 71. An end 260a of the overlapping portion 260 on the opposite side from the valve disc 2 side is formed in a semicircular shape. The end 260a does not reach the non-valve-disc-side inner surface 81 of the seal accommodating space 8. In other words, the end 260a is located closer to the valve disc 2 than the non-valve-disc-side inner surface 81.

[0070] (Details of the communication and blocking states of the fluid passages) The following describes in detail the connected and blocked states of the fluid passage 6. When the pressure in the primary flow path 11 is greater than the pressure in the secondary flow path 11 with the valve element 2 in the closed state, the two-way ball valve 100 operates as follows.

[0071] First, the primary side will be described with reference to FIGS. 8 and 9. When the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 when the valve disc 2 is closed, the primary-side seal member 5 moves toward the valve disc 2 within the seal accommodating space 8 along the closed-state pressurization direction (X1 direction). The primary-side seal member 5 is then pressed against the valve-disc-side inner surface 80. In other words, the primary-side seal member 5 is positioned biased toward the valve disc 2 within the seal accommodating space 8. As a result, with the primary-side seal member 5 pressed against the valve-disc-side inner surface 80, the end 260a of the overlapping portion 260 on the side opposite to the valve disc 2 side is open without being blocked by the seal member 5. In other words, an opening OP is formed at the end 260a. As a result, the fluid passing portion 206 is in a communicating state in which the primary-side flow path 11 and the valve disc accommodating portion 10 communicate with each other.

[0072] Next, the secondary side will be described with reference to FIG. 10 . When the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 when the valve disc 2 is closed, the secondary-side seal member 5 moves in the closed-time pressurization direction (X1 direction) within the seal accommodating space 8 toward the side opposite the valve disc 2. The secondary-side seal member 5 is then pressed against the non-valve-disc-side inner surface 81. In other words, the secondary-side seal member 5 is positioned offset toward the side opposite the valve disc 2 within the seal accommodating space 8. As a result, with the secondary-side seal member 5 pressed against the non-valve-disc-side inner surface 81, the end 260a of the overlapping portion 260 opposite the valve disc 2 is blocked by the seal member 5 and closed. As a result, the fluid passing portion 206 enters a blocked state in which it blocks the secondary-side flow path 11 and the valve disc accommodating portion 10.

[0073] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0074] In the second embodiment, as described above, when the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 in the closed state, the primary-side seal member 5 is moved within the seal accommodating space 8 toward the valve disc 2 in the closing pressurization direction, and the fluid passing portion 206 is provided to establish a communication state between the primary-side flow path 11 and the valve disc accommodating portion 10, thereby reducing the pressure difference between the primary-side flow path 11 and the valve disc accommodating portion 10. This reduces the load on the seal member 5 when reducing the operating torque for switching the valve disc 2 from the closed state to the open state, as in the first embodiment. In addition, the fluid passing portion 206 can also prevent fluid from flowing from the valve disc accommodating portion 10 to the secondary-side flow path 11 in the closed state.

[0075] As described above, in the second embodiment, the seal accommodating space 8 is an annular recess provided in the outer peripheral surface 41 of the seat ring 4 and extending in the circumferential direction of the seat ring 4, and the fluid passing portion 206 is recessed in the inner peripheral portion of the body 1. Thus, simply by providing the recessed fluid passing portion 206 in the inner peripheral portion of the body 1, it is possible to easily reduce the load on the seal member 5 when reducing the operating torque for switching the valve disc 2 from the closed state to the open state.

[0076] In the second embodiment, as described above, the fluid passing portion 206 is recessed into the inner circumferential portion of the body 1, and includes, in the direction along the pressurization direction at closing, an overlapping portion 260 that overlaps with a portion of the seal accommodating space 8, and a non-overlapping portion 261 that is positioned closer to the valve disc 2 than the overlapping portion 260 and does not overlap with the seal accommodating space 8. This allows the fluid in the primary flow path 11 to flow in from the seal accommodating space 8 via the overlapping portion 260, and allows the fluid to flow out to the interface 7 on the valve disc accommodating portion 10 side via the non-overlapping portion 261.

[0077] (Third embodiment) A third embodiment will be described with reference to Fig. 11. Unlike the first embodiment in which the fluid passing portion 6 is provided in the seat ring 4, which is configured to provide the seal accommodating space 8 of the seal member 5, the third embodiment describes an example in which the fluid passing portion 306 is provided in a seal member 305, rather than in the seat ring 4, which is configured to provide the seal accommodating space 8 of the seal member 5. Note that in the drawings, components similar to those in the first embodiment are denoted by the same reference numerals.

[0078] 11 includes two seal members 305 and two fluid passages 306, one on the primary side and one on the secondary side of the valve element accommodating section 10. The two fluid passages 306 are a pair, one on the primary side and one on the secondary side of the valve element 2.

[0079] When the pressure in the primary flow path 11 is greater than the pressure in the secondary flow path 11 in the closed state, the fluid passing portion 306 is in a communicating state where the primary flow path 11 communicates with the valve element accommodating portion 10 with the primary side seal member 305 moved within the seal accommodating space 8 toward the valve element 2 along the closing pressurization direction, thereby reducing the pressure difference between the primary side flow path 11 and the valve element accommodating portion 10, and is in a blocking state where the secondary side seal member 305 is moved within the seal accommodating space 8 toward the opposite side from the valve element 2 along the closing pressurization direction, thereby blocking the secondary side flow path 11 from the valve element accommodating portion 10. The specific configuration of the fluid passing portion 306 will be described below.

[0080] The fluid passage 306 is recessed in the seal member 305. The fluid passage 306 is a seal groove provided on the outer periphery of the seal member 305. The fluid passage 306 is in a communicating state when an adjacent portion 305a of the seal member 305 adjacent to the seal groove on the outer periphery of the primary side is deformed by the pressure of the primary-side flow path 11 and moves (flexes) toward the valve disc 2, and the fluid passage 306 is in a blocked state when the adjacent portion 305a of the seal member 305 on the outer periphery of the secondary side is deformed by the pressure of the valve disc accommodating portion 10 and moves (flexes) away from the valve disc 2. The adjacent portion 305a is located on the opposite side of the fluid passage 306, which is a seal groove, from the valve disc 2. The adjacent portion 305a is a thin-walled portion of the seal member 305 formed by the fluid passage 306, which is a seal groove.

[0081] The primary-side adjacent portion 305a changes from a state in contact with the non-valve-disc-side inner surface 81 to a state in which it is separated from the non-valve-disc-side inner surface 81, forming a gap between the inner circumferential surface 14 of the body 1 and the seal member 305, and the fluid passing portion 306 enters a communicating state in which it communicates between the primary-side flow path 11 and the valve disc accommodating portion 10. The secondary-side adjacent portion 305a enters a contacting state with the inner circumferential surface 14 of the body 1, the bottom surface 82 of the seal accommodating space 8, and the non-valve-disc-side inner surface 81. That is, the entire circumferential direction of the secondary-side seal member 305 abuts against the bottom surface 82 of the seal accommodating space 8 and the inner circumferential surface 14 of the body 1, and is compressed between the bottom surface 82 and the inner circumferential surface 14, and the fluid passing portion 306 enters a blocking state in which it blocks the secondary-side flow path 11 and the valve disc accommodating portion 10.

[0082] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0083] In the third embodiment, as described above, when the pressure in the primary-side flow path 11 is greater than the pressure in the secondary-side flow path 11 in the closed state, the primary-side seal member 305 is moved within the seal accommodating space 8 toward the valve disc 2 in the closing pressurization direction, and the fluid passing portion 306 is in a communicating state that connects the primary-side flow path 11 and the valve disc accommodating portion 10, thereby reducing the pressure difference between the primary-side flow path 11 and the valve disc accommodating portion 10. This reduces the load on the seal member 305 when reducing the operating torque for switching the valve disc 2 from the closed state to the open state, as in the first embodiment. In addition, the fluid passing portion 306 can also prevent fluid from flowing from the valve disc accommodating portion 10 to the secondary-side flow path 11 in the closed state.

[0084] In the third embodiment, as described above, the seal accommodating space 8 is an annular recess provided in the outer peripheral surface 41 of the seat ring 4 and extending in the circumferential direction of the seat ring 4, and the fluid passing portion 306 is recessed in the seal member 305. Thus, simply by providing the recessed fluid passing portion 306 in the seal member 305, it is possible to easily reduce the load applied to the seal member 305 when reducing the operating torque for switching the valve disc 2 from the closed state to the open state.

[0085] In the third embodiment, as described above, the fluid passing portion 306 is a seal groove portion provided on the outer periphery of the seal member 305, and an adjacent portion 305a of the seal member 305 adjacent to the seal groove portion on the outer periphery on the primary side is deformed by the pressure of the primary-side flow path 11 and moves toward the valve disc 2, thereby establishing a communicating state, and an adjacent portion 305a of the seal member 305 on the outer periphery on the secondary side is deformed by the pressure of the valve disc accommodating portion 10 and moves away from the valve disc 2, thereby establishing a blocked state. In this way, the fluid passing portion 306 can be formed by the seal member 305, and therefore the fluid passing portion 306 can be formed without providing a recessed shape for forming the fluid passing portion 306 in the body 1 and the seat ring 4.

[0086] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0087] For example, in the first to third embodiments, the sealing member is an O-ring, but the present invention is not limited to this. In the present invention, the sealing member may be a so-called U-packing or an X-ring.

[0088] Furthermore, in the first to third embodiments, an example was shown in which the seat ring is provided with a seal accommodating space for accommodating an O-ring, but the present invention is not limited to this. In the present invention, as in a two-way ball valve 400 of a first modified example shown in Fig. 12, the body 1 may be provided with a seal accommodating space 8 for accommodating an O-ring. In this case, a fluid passage 406 can be provided in the seal accommodating space 8 of the body 1. In this case, the seat ring may also be provided with a fluid passage.

[0089] In the first embodiment, the fluid passage 506 is formed by a circular recess when viewed along the recess direction, but the present invention is not limited to this. In the present invention, as in the second modified example shown in FIG. 13 , the fluid passage 506 may be formed by a rectangular groove when viewed along the recess direction. The fluid passage 506 may be formed into an oval or elliptical shape instead of a rectangular shape when viewed along the recess direction. The fluid passage 506 formed by a groove has a rectangular cross section. Instead of a rectangular cross section, the fluid passage 506 may be formed into a U-shaped or V-shaped cross section.

[0090] In the first embodiment, the first passage portion of the fluid passing portion is formed by a conical recess, but the present invention is not limited to this. In the present invention, the first passage portion of the fluid passing portion may be formed by a cylindrical recess that extends in the depth direction with the same diameter.

[0091] In addition, in the first to third embodiments, examples have been shown in which only one fluid passing portion is provided in the circumferential direction, but the present invention is not limited to this. In the present invention, a plurality of fluid passing portions may be provided in the circumferential direction.

[0092] In the first embodiment, only the seat ring is provided with a fluid passage, in the second embodiment, only the body is provided with a fluid passage, and in the third embodiment, only the seal member is provided with a fluid passage, but the present invention is not limited to this. In the present invention, fluid passages may be provided in any two or three of the seat ring, the body, and the seal member.

[0093] In addition, although the flow paths are formed linearly in the first to third embodiments, the present invention is not limited to this. In the present invention, the flow paths may be formed in a shape other than linear, such as an L-shape. [Explanation of symbols]

[0094] 1 Body 2 Valve body 4 seat ring 5, 305 sealing material 6, 206, 306, 406, 506 Fluid passage section 7 Interface 8 Seal storage space 10 Valve body housing 11 Flow path 14 (Body) inner surface 41 (Seat ring) outer surface 60 1st passage part 60b (the end portion opposite to the valve body side of the first passage portion) 61 2nd passage part 80 (Seal accommodating space) valve body side inner surface 81 (Seal receiving space) non-valve body side inner surface 82 (Seal storage space) bottom 100, 200, 300, 400 two-way ball valve 260 (Fluid passage) overlapping portion 261 (Fluid passage) non-overlapping portion 305a (of the sealing member) adjacent part

Claims

1. A two-way ball valve that can switch between a primary side and a secondary side, a valve body that switches between a closed state and an open state by rotation; a body including a valve element accommodating portion that accommodates the valve element, and two flow paths provided on the primary side and the secondary side of the valve element accommodating portion; two seat rings configured to abut against the valve element, one on the primary side and one on the secondary side of the valve element accommodating portion; two seal members disposed in a seal accommodating space at an interface between the seat ring and the body, one on the primary side and one on the secondary side of the valve body accommodating portion; two fluid passing portions provided on the primary side and the secondary side of the valve body accommodating portion, a valve accommodating space for moving the primary-side seal member toward the valve disc in the seal accommodating space along the closing-time pressurization direction, the fluid passage portion being in a communicating state where the primary-side flow path communicates with the valve disc accommodating space, thereby reducing the pressure difference between the primary-side flow path and the valve disc accommodating space, when the pressure in the primary-side flow path is greater than the pressure in the secondary-side flow path in the closed state; and a valve accommodating space for moving the secondary-side seal member toward the valve disc in the seal accommodating space along the closing-time pressurization direction, the fluid passage portion being in a blocking state where the secondary-side flow path is blocked from the valve disc accommodating space.

2. the seal accommodating space is an annular recess provided in an outer peripheral surface of the seat ring and extending along a circumferential direction of the seat ring, 2. The two-way ball valve according to claim 1, wherein the fluid passage is recessed in the outer circumferential portion of the seat ring, the inner circumferential portion of the body, or the seal member.

3. 3. The two-way ball valve according to claim 2, wherein the fluid passage portion is formed by a recess or a groove provided in the seal accommodating space.

4. The two-way ball valve according to claim 3 , wherein the recessed portion is formed in a circular shape when viewed from a direction along the recessed portion.

5. the fluid passage is recessed in the outer circumferential portion of the seat ring, the seal accommodating space, which is the annular recess, has a valve body side inner surface on the valve body side, a non-valve body side inner surface on the opposite side from the valve body side, and a bottom surface connecting the valve body side inner surface and the non-valve body side inner surface, 3. The two-way ball valve according to claim 2, wherein the fluid passage portion includes a first concave passage portion provided on the bottom surface, and a second concave passage portion communicating with the first passage portion and provided on the valve body-side inner surface.

6. 6. The two-way ball valve according to claim 5, wherein the first passing portion is disposed on the bottom surface toward the valve body side inner surface and is provided so as to reach the valve body side inner surface.

7. When the pressure in the primary side flow path is greater than the pressure in the secondary side flow path in the closed state, the primary side seal member moves within the seal accommodating space toward the valve body and is pressed against the valve body side inner surface, 6. The two-way ball valve according to claim 5, wherein, when the primary-side seal member is pressed against the valve body-side inner surface, the end of the first passing portion opposite the valve body side is open without being blocked by the seal member.

8. the fluid passage is recessed in the inner circumferential portion of the body, 3. The two-way ball valve according to claim 2, wherein the fluid passage portion includes, in a direction along the closing pressurization direction, an overlapping portion that overlaps with a part of the seal accommodating space, and a non-overlapping portion that is positioned closer to the valve body than the overlapping portion and does not overlap with the seal accommodating space.

9. 3. The two-way ball valve according to claim 2, wherein the fluid passage portion is a seal groove portion provided on an outer circumferential side of the seal member, and an adjacent portion of the seal member adjacent to the seal groove portion on the outer circumferential side of the primary side is deformed by the pressure of the flow path on the primary side and moves toward the valve body, thereby achieving the communicating state, and the adjacent portion of the seal member on the outer circumferential side of the secondary side is deformed by the pressure of the valve body accommodating portion and moves toward the opposite side from the valve body, thereby achieving the blocked state.

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