Valve device
The valve device stabilizes the operating diaphragm operation by positioning the passage opening outside the fluid ejection direction and using heat-resistant sealing members to prevent fluid ingress, addressing instability and wear issues in conventional designs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- BEN CO LTD
- Filing Date
- 2023-01-13
- Publication Date
- 2026-06-29
AI Technical Summary
Conventional valve devices experience unstable operation of the operating diaphragm due to fluctuations in pressure differences between chambers caused by fluid ejection directly hitting the passage openings and entering through gaps between the valve stem and bearing, leading to wear and durability issues.
The valve device incorporates a passage design where the opening at one end is positioned outside the fluid ejection direction and equipped with a heat-resistant sealing member on the bearing to prevent fluid ingress, stabilizing the operating diaphragm operation and reducing wear.
This design stabilizes the operating diaphragm operation, prevents hunting, and enhances durability by minimizing pressure fluctuations and reducing wear on the valve body and sliding parts, even with high-temperature fluids.
Smart Images
Figure 0007881271000001 
Figure 0007881271000002 
Figure 0007881271000003
Abstract
Description
Technical Field
[0001] The present invention mainly relates to a valve device provided in a piping system through which a high-temperature fluid such as steam flows. In particular, the present invention relates to a valve device such as a pressure reducing valve that includes a diaphragm and opens and closes a flow path based on the pressure difference between both sides of the diaphragm.
Background Art
[0002] Conventionally, as this type of valve device, for example, the technology of a pressure reducing valve for steam described in Japanese Patent No. 3660339 (Patent Document 1) is known. As shown in FIG. 8, this valve device Sa includes a main body 100 having an inlet 101 and an outlet 102 and forming a flow path through which a fluid that is steam flows. In this main body 100, a primary chamber 104 on the inlet 101 side and a secondary chamber 105 on the outlet 102 side are provided by partitioning the flow path with a partition wall 103. A valve port 106 through which the fluid can pass is formed in the partition wall 103. A valve body 107 for opening and closing the valve port 106 is provided on the primary chamber 104 side. A valve rod 109 is provided on the secondary chamber 105 side, one end of which supports the valve body 107 and the other end of which is linked to an operating diaphragm 108. In the main body 100, an operating chamber 112 is provided which is separated from the secondary chamber 105 by a partition wall 111 facing the valve port 106 and in which the operating diaphragm 108 is housed. This operating chamber 112 is composed of an upper chamber 113 on the partition wall 111 side and a lower chamber 114 partitioned by the operating diaphragm 108. The valve rod 109 is provided so as to penetrate through the partition wall 111 in a reciprocating manner. The valve body 107 is biased by a coil spring 115 in a direction to close the valve port 106. Further, in this valve device Sa, a bearing 116 for supporting the valve rod 109 in a reciprocating manner is provided on the partition wall 111. In the vicinity of the valve rod 109 and outside the bearing 116, a narrow passage 117 communicating the secondary chamber 105 and the upper chamber 113 of the operating chamber 112 is formed. The valve rod 109 is reciprocated through the operating diaphragm 108 by the pressure difference between the fluid flowing from the secondary chamber 105 through the passage 117 into the upper chamber 113 of the operating chamber 112 and the fluid in the lower chamber 114, and the valve port 106 is opened and closed by the valve body 107.
[0003] This valve device Sa includes a control unit 120 that controls the operation of the operating diaphragm 108. When the pressure on the secondary chamber 105 side drops below a predetermined pressure, the control unit 120 allows fluid from the primary chamber 104 to flow in through the inlet 121 of the lower chamber 114 of the operating chamber 112, causing the operating diaphragm 108 to advance the valve stem 109 against the biasing force of the spring 115, opening the valve port 106 with the valve body 107, and allowing fluid to flow out from the primary chamber 104 through the valve port 106 to the secondary chamber 105 side. When the pressure on the secondary chamber 105 side exceeds a predetermined pressure, the control unit 120 stops the fluid from the primary chamber 104 from flowing into the lower chamber 114 of the operating chamber 112, causing the operating diaphragm 108 to retract the valve stem 109 due to the biasing force of the spring 115, closing the valve port 106 with the valve body 107, and stopping the outflow of fluid from the primary chamber 104 to the secondary chamber 105 side. This ensures that the fluid pressure in the secondary chamber 105 is maintained at a predetermined pressure lower than the fluid pressure in the primary chamber 104. [Prior art documents] [Patent Documents]
[0004] [Patent Document 1] Patent No. 3660339 [Overview of the project] [Problems that the invention aims to solve]
[0005] By the way, in this conventional valve device Ta, when the pressure on the secondary chamber 105 side falls below a predetermined pressure, the valve body 107 opens the valve port 106, allowing fluid to flow from the primary chamber 104 through the valve port 106 to the secondary chamber 105 side. At this time, the fluid on the primary chamber 104 side is ejected from the valve port 106 into the secondary chamber 105. In this case, the opening 117a of the passage 117 is the ejection region of the fluid ejected from the valve port 106 to the secondary chamber side 105 and is opposite to the ejection direction. As a result, this ejected flow hits the opening 117a of the passage 117 and attempts to flow into the upper chamber 113 of the working chamber 112. In this case, the pressure difference between the upper chamber 113 and the lower chamber 114 of the working chamber 112 fluctuates greatly, making the operation of the working diaphragm 108 unstable.
[0006] Furthermore, the opening of the bearing 116 of the valve stem 109 is also in the fluid ejection region and faces the ejection direction. Therefore, the ejected flow attempts to enter to some extent not only through the passage 117 but also through the gap between the valve stem 109 and the bearing 116. In this respect as well, it affects fluctuations in the pressure difference between the upper chamber 113 and the lower chamber 114 of the working chamber 112, making the operation of the working diaphragm 108 unstable. When the operation of the working diaphragm 108 becomes unstable, it can cause so-called hunting, and because the valve body 107 moves in small increments, wear on the valve body 107 itself and the sliding parts of the valve stem 109 accelerates, which is an undesirable problem as it impairs durability.
[0007] The present invention has been made in view of the above-mentioned problems, and aims to provide a valve device that prevents the fluid ejected from the valve port into the secondary chamber from directly hitting the passage, and also prevents ingress from the sliding part of the valve stem, thereby suppressing fluctuations in the pressure difference between the upper and lower chambers in the operating chamber of the operating diaphragm and stabilizing the operation of the operating diaphragm. [Means for solving the problem]
[0008] To achieve this objective, the valve device of the present invention comprises a body having an inlet and an outlet and forming a fluid passage through which fluid flows, the body having a primary chamber on the inlet side and a secondary chamber on the outlet side formed by partitioning the passage with a partition wall, a valve opening through which fluid can pass, a valve body for opening and closing the valve opening provided in the primary chamber, a valve stem with one end supporting the valve body and the other end connected to an operating diaphragm provided on the secondary chamber side, the body having an operating chamber separated from the secondary chamber by a partition wall facing the valve opening and housing the operating diaphragm, the operating chamber comprising an upper chamber on the partition wall side and a lower chamber partitioned by the operating diaphragm, and the valve stem provided so as to penetrate the partition wall so as to be able to move back and forth. In a valve device in which a passage is provided with one end opening to the secondary chamber and the other end opening to the upper chamber of the operating chamber, the valve stem is moved back and forth via the operating diaphragm by the pressure difference between the fluid flowing from the secondary chamber through the passage to the upper chamber of the operating chamber and the fluid in the lower chamber, the valve body opens and closes the valve port, A bearing on which the valve stem can slide is provided in the above-mentioned partition wall, and a seal portion having a heat-resistant sealing member that the valve stem slides against is provided in the bearing. The opening at one end of the above passage is formed so as not to face the direction of fluid ejection from the valve opening toward the secondary chamber.
[0009] In other words, the opening at one end of the above passage is formed outside the ejection area of the fluid ejected from the valve port to the secondary chamber, or it is formed within the ejection area of the fluid ejected from the valve port to the secondary chamber so as not to face the ejection direction. The ejection direction of the fluid from this valve port is the linear direction within the ejection area of the fluid that is expanded and ejected from the valve port, as shown in Figure 4. The opening at one end may be located outside this ejection area, and even if it is within the ejection area, it is sufficient as long as the opening does not face the ejection direction.
[0010] Examples of heat-resistant sealing members include braided packing, metal packing, laminated packing, graphite packing, fluororesin packing, etc., which are formed by butting both ends together to form a ring shape, or by integrally forming a continuous ring shape, or by using a ring-shaped oil seal packing with an internal spring.
[0011] As a result, when fluid is introduced into the lower chamber of the working chamber, the working diaphragm advances the valve stem, the valve body opens the valve port, and the fluid flows out from the primary chamber through the valve port to the secondary chamber, the fluid is ejected from the valve port and directed towards one end opening of the passage. However, this end opening is formed so as not to be opposed to the direction of the fluid ejection from the valve port. Therefore, the situation in which the ejected fluid flow directly hits the end opening of the passage and attempts to flow into the upper chamber of the working chamber is prevented, and thus the fluctuation in the pressure difference between the upper and lower chambers of the working chamber can be made extremely small.
[0012] Furthermore, the opening of the valve stem bearing faces the direction of fluid ejection, and the ejected fluid flow into the secondary chamber attempts to enter through the gap between the valve stem and the bearing. However, the bearing has a sealing portion with a sealing member that the valve stem slides against, preventing fluid from entering from the sliding part of the valve stem. In this respect as well, fluctuations in the pressure difference between the upper and lower chambers of the working chamber can be kept extremely small.
[0013] As a result, the operation of the operating diaphragm can be stabilized, preventing so-called hunting, and the wear on the valve body itself and sliding parts can be reduced, thereby improving durability. In particular, since the sealing member that the valve stem slides against is heat-resistant, deformation of the sealing member can be prevented when the fluid is high-temperature steam, and wear on the sliding parts of the valve stem and bearing is further reduced, thereby improving durability. In this case, since one end opening of the passage is not blocked, communication between the secondary chamber and the upper chamber of the operating chamber is ensured by the passage, and therefore it does not affect the normal operation of the operating diaphragm.
[0014] Furthermore, as necessary, the above-mentioned passage is constructed by providing one end opening in the wall of the main body near the outlet or in the wall of the connecting pipe connected to the outlet, and connecting the one end opening and the other end opening with a pipe routed outside the main body. This ensures that the one end opening is positioned away from the valve opening, thereby reliably preventing the fluid jet from directly hitting the one end opening of the passage and flowing into the upper chamber of the working chamber, and thus minimizing fluctuations in the pressure difference between the upper and lower chambers of the working chamber.
[0015] Furthermore, the passage is provided on the valve stem as needed. More specifically, one end opening of the passage is formed on the side surface of the valve stem, and the other end opening of the passage is also formed on the side surface of the valve stem. The two end openings are connected by a through hole drilled from the other end of the valve stem along the axis of the valve stem. As a result, the passage is formed on the valve stem, making it easier to manufacture and simplifying the structure.
[0016] Furthermore, if necessary, a rod is provided in the secondary chamber, erected on the partition wall, and the passage is formed on the rod with the one-end opening at its tip. one One side passage and the other end opening formed in the partition wall. Others that possess It is configured with a passage on one side. By creating a rod in advance and installing it in the bulkhead, the passage can be easily constructed.
[0017] Furthermore, as necessary, the seal portion may be configured to include a plurality of overlapping ring-shaped seal members that slide against the valve stem, and a holding portion that is connected to the secondary chamber side of the bearing and protrudes into the secondary chamber, and which houses and holds the plurality of seal members in an overlapping manner. The holding portion may be configured to include a housing having a support surface for supporting the lower seal member of the plurality of seal members and a recess having an inner surface into which the outer surface of each seal member can abut, a nut having an insertion hole through which the valve stem is inserted and a female thread that screws onto a male thread formed on the outside of the housing, and a retaining ring that is inserted onto the valve stem and provided on the upper seal member of the plurality of seal members, and which presses and holds the plurality of seal members when the nut is screwed onto the male thread.
[0018] As a result, multiple sealing members are pressed and held in place via a retaining ring by screwing in a nut, ensuring a secure seal between the valve stem and the bearing, and reliably preventing fluid from entering from the sliding part of the valve stem. Therefore, it is possible to reliably prevent fluctuations in the pressure difference between the upper and lower chambers of the working chamber.
[0019] In this case, it is effective to form a male threaded portion on the outer circumference of the bearing, while forming a female threaded portion in the partition wall into which the male threaded portion screws, and then screwing the male threaded portion into the female threaded portion to install the bearing in the partition wall. Since the bearing can be attached and detached by screwing, the assembly of the seal and the bearing can be made easier.
[0020] Furthermore, if necessary, the primary chamber may be provided with a valve spring that biases the valve body in the retraction direction of the valve stem and in the direction that closes the valve opening, and a control unit that controls the operation of the operating diaphragm, the control unit being configured to include an operating pipeline provided between the primary chamber and the lower chamber of the operating chamber, and a pilot valve provided in the middle of the operating pipeline that opens the operating pipeline when the pilot pressure on the secondary chamber side falls below a predetermined pressure and closes the operating pipeline when the pilot pressure exceeds a predetermined pressure, When the pilot valve of the control unit opens the operating pipeline, the operating diaphragm advances the valve stem against the biasing force of the valve body spring, opening the valve port with the valve body and allowing fluid to flow from the primary chamber through the valve port to the secondary chamber. When the pilot valve of the control unit closes the operating pipeline, the operating diaphragm retracts the valve stem due to the biasing force of the valve body spring, closing the valve port with the valve body and stopping the outflow of fluid from the primary chamber to the secondary chamber. This configuration can accommodate an operating diaphragm that is operated by pilot pressure. [Effects of the Invention]
[0021] As described above, according to the valve device of the present invention, when fluid is ejected from the valve port, the fluid is directed towards one end opening of the passage. However, this one end opening is formed so as not to face the direction of fluid ejection from the valve port. Therefore, the situation in which the ejected fluid flow directly hits the one end opening of the passage and attempts to flow into the upper chamber of the working chamber is prevented, and thus the fluctuation in the pressure difference between the upper and lower chambers of the working chamber can be made extremely small. Furthermore, the opening of the valve stem bearing faces the direction of fluid ejection, and the ejected fluid flow that has been ejected into the secondary chamber attempts to enter through the gap between the valve stem and the bearing. However, the bearing has a sealing portion with a sealing member that the valve stem slides against, which prevents fluid from entering from the sliding part of the valve stem. In this respect as well, the fluctuation in the pressure difference between the upper and lower chambers of the working chamber can be made extremely small.
[0022] As a result, it is possible to stabilize the operation of the operating diaphragm, prevent a situation where so-called hunting occurs, and make it difficult for the valve body itself and the sliding part to wear, thereby improving durability. In particular, the seal member that slidably contacts the valve rod has heat resistance. Therefore, when the fluid is high-temperature steam, it is possible to prevent deformation of the seal member and further make it difficult for the sliding parts of the valve rod and the bearing to wear, thereby improving durability even more.
Brief Description of the Drawings
[0023] [Figure 1] It is a perspective view showing a valve device according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view taken along line A-A in FIG. 1 showing a valve device according to an embodiment of the present invention. [Figure 3] It is a cross-sectional view taken along line B-B in FIG. ..... [Figure 4] It is an enlarged cross-sectional view showing a main part of a valve device according to an embodiment of the present invention. [Figure 5] It is a cross-sectional view equivalent to FIG. 2 showing a valve device according to another embodiment of the present invention. [Figure 6] It is a cross-sectional view equivalent to FIG. 2 showing a valve device according to still another embodiment of the present invention. [Figure 7] It is a cross-sectional view equivalent to FIG. 2 showing a valve device according to yet another embodiment of the present invention. [Figure 8] It is a cross-sectional view showing an example of a conventional valve device. <00001ll>
Embodiments for Carrying Out the Invention
[0024] Hereinafter, based on the accompanying drawings, a valve device according to an embodiment of the present invention will be described in detail. As shown in Figures 1 to 4, the valve device S according to an embodiment of the present invention is a pressure reducing valve for steam and comprises a main body 1 having an inlet 2 and an outlet 3 that form a fluid flow path. The main body 1 comprises a pipe 4 formed such that the axes of the inlet 2 and outlet 3 are located on a one-way centerline P. The pipe 4 has a lower opening 5 and an upper opening 6 formed on a two-way centerline Q perpendicular to the one-way centerline P. A lower body 8 is attached to the lower opening 5, which has a partition wall 7 that closes the lower opening 5 and provides an operating chamber 30 for an operating diaphragm 18 (described later) separated by this partition wall 7. An upper body 10 is attached to the upper opening 6, which constitutes a control unit 60 (described later) and has a base wall 11 that closes the upper opening 6. The main body 1 is composed of the pipe 4, the lower body 8 and the upper body 10.
[0025] Inside the pipe body 4, a partition wall 12 is provided that crosses the unidirectional centerline P and separates the inlet 2 and upper opening 6 side from the outlet 3 and lower opening 5 side. As a result, the main body 1 is formed by dividing the flow path with the partition wall 12, and has a primary chamber 13 on the inlet 2 side and a secondary chamber 14 on the outlet 3 side. A valve port 15 is formed in the partition wall 12, through which a fluid with the other-directional centerline Q as its axis can pass. The valve port 15 is formed in a valve seat body 16 that is attached to the partition wall 12 by screw connection. In addition, a valve body 17 that opens and closes the valve port 15 is provided in the primary chamber 13.
[0026] On the secondary chamber 14 side, a valve stem 20 is provided, with one end supporting the valve body 17 and the other end linked to an operating diaphragm 18, with the other-direction centerline Q as its axis. Furthermore, the primary chamber 13 is provided with a valve body spring 21, which is a coil spring that biases the valve body 17 in the retraction direction of the valve stem 20 and in the direction that closes the valve opening 15. The valve body spring 21 has the other-direction centerline Q as its axis, with one end held by a spring holder 22 provided on the base wall 11 and the other end locked to the valve body 17.
[0027] Furthermore, the lower body 8 that constitutes the main body 1 is provided with an operating chamber 30 that houses the operating diaphragm 18, separated from the secondary chamber 14 by a partition wall 7 of the lower body 8 facing the valve port 15. The operating chamber 30 consists of an upper chamber 31 on the partition wall 7 side and a lower chamber 32 separated by the operating diaphragm 18. The valve stem 20 is provided so as to penetrate the partition wall 7 so as to be able to move back and forth.
[0028] Furthermore, in this embodiment, a passage R is provided, with one end opening Ra opening towards the secondary chamber 14 and the other end opening Rb opening towards the upper chamber 31 of the working chamber 30. The one end opening Ra of this passage R is formed so as not to be opposed to the direction of fluid ejection from the valve port 15 towards the secondary chamber 14. The one end opening Ra is provided protruding from the wall of the connecting pipe 33 connected to the outlet 3, and is formed outside the ejection region E (Figure 4) of the fluid ejected from the valve port 15 towards the secondary chamber 14. The other end opening Rb is formed on the wall of the lower body 8 on the outlet 3 side. Specifically, on the outlet 3 side of the pipe body 4, a plate-shaped, ring-shaped outlet side flange 34 is formed protruding around the outlet 3, while the end of the connecting pipe 33 is provided with a connecting flange 35 that is joined to the outlet side flange 34. The connecting pipe 33 is connected to the pipe body 4 by joining the outlet side flange 34 and the connecting flange 35 and fastening them with bolts and nuts (not shown).
[0029] The opening at one end Ra and the opening at the other end Rb are connected by a pipe 36 that is routed to the outside of the main body 1. One end of the pipe 36 is connected to the opening at one end Ra via an adapter 37. The adapter 37 consists of a tubular bush 37a that is screwed into the opening at one end Ra, and a nut 37b that is screwed into the bush 37a and holds the end of the pipe 36 together with the bush 37a via a cone 38. The other end of the pipe 36 is also connected to the opening at the other end Rb via an adapter 37. The adapter 37 at the other end of this pipe 36 also consists of a tubular bush 37a that is screwed into the opening at the other end Rb, and a nut 37b that is screwed into the bush 37a and holds the other end of the pipe 36 together with the bush 37a via a cone 38.
[0030] As a result, the pressure difference between the fluid flowing from the secondary chamber 14 through the passage R into the upper chamber 31 of the working chamber 30 and the fluid in the lower chamber 32 causes the valve stem 20 to move back and forth via the working diaphragm 18, thereby opening and closing the valve port 15 by the valve body 17.
[0031] Furthermore, as shown in Figure 4, the partition wall 7 is provided with a bearing 40 having an insertion hole 41 through which the valve stem 20 is inserted so as to be able to move back and forth, with the other-direction centerline Q as its axis. The bearing 40 is composed of a male threaded portion 42 with the other-direction centerline Q as its axis on the working chamber 30 side and a base portion 43 protruding on the secondary chamber 14 side. The partition wall 7 has a female threaded portion 44 with the other-direction centerline Q as its axis, and the bearing 40 is attached to the partition wall 7 by screwing its male threaded portion 42 into the female threaded portion 44.
[0032] Furthermore, the bearing 40 is provided with a seal portion 50 having a heat-resistant seal member 51 that slides against the valve stem 20. In this embodiment, the seal member 51 may be made of, for example, a braided packing, a metal packing, a laminated packing, a graphite packing, a fluororesin packing, etc., and may be formed in a ring shape by butting both ends together, or as a packing integrally formed in a continuous ring shape, or as a ring-shaped oil seal packing with a spring built inside. In this embodiment, a Teflon® packing made of a single material and formed in a continuous ring shape is used. Specifically, as shown in Figure 4, the seal portion 50 is configured to include a plurality of overlapping seal members 51 (three in this embodiment) that slide against the valve stem 20, and a holding portion 52 that is connected to the secondary chamber 14 side of the bearing 40 and protrudes into the secondary chamber 14, and houses and holds the plurality of overlapping seal members 51. The holding portion 52 is composed of a housing 53 made up of a base 43 of a bearing 40 which is integrally formed with the bearing 40 and has a recess having a support surface for supporting the lower seal member 51 of the plurality of seal members 51 and an inner surface that can contact the outer surface of each seal member 51; a nut 56 which has an insertion hole through which the valve stem 20 is inserted and has a female thread 55 that screws onto a male thread 54 formed on the outside of the housing 53; and a retaining ring 57 which is inserted on the valve stem 20 and is provided on the upper seal member 51 of the plurality of seal members 51, and presses and holds the plurality of seal members 51 by screwing the nut 56 onto the male thread 54.
[0033] Furthermore, the device is equipped with a control unit 60 that controls the operation of the operating diaphragm 18. As shown in Figures 2 and 3, the control unit 60 is configured to include an operating pipeline 61 provided between the primary chamber 13 and the lower chamber 32 of the operating chamber 30, a pilot valve 62 provided in the middle of the operating pipeline 61 that opens the operating pipeline 61 when the pilot pressure on the secondary chamber 14 side falls below a predetermined pressure and closes the operating pipeline 61 when the pilot pressure exceeds the predetermined pressure, and a relief pipeline 63 (Figure 1) provided on the lower chamber 32 side of the pilot valve 62 that releases the fluid in the operating pipeline 61 to the secondary chamber 14.
[0034] More specifically, the upper body 10 houses a pilot valve 62 and is provided with a valve chamber 64 separated from the primary chamber 13 by a base wall 11. A connecting passage 65 (Figure 3) is formed in the base wall 11, connecting the primary chamber 13 and the valve chamber 64. Outside the main body 1, there is a first pipe 66 (Figures 1 and 3) piped between the valve chamber 64 and the inlet 32a of the lower chamber 32 of the operating chamber 30, and a second pipe 67 that branches off from the first pipe 66 and is piped to the secondary chamber 14 of the pipe body 4. The operating pipeline 61 is composed of the passage formed by the connecting passage 65 - valve chamber 64 - first pipe 66, and the relief pipeline 63 is composed of the passage formed by the second pipe 67.
[0035] In the control unit 60, a pilot valve port 68 is formed in the valve chamber 64 with the other-direction centerline Q as its axis. The pilot valve 62 is provided on the communication passage 65 side and is held at the other end of a first spring 69, which is a coil spring with one end supported by a spring holder 22 of the base wall 11. The pilot valve 62 is constantly biased by this first spring 69 in the direction of closing the pilot valve port 68. Above the pilot valve 62 of the upper body 10, a drive unit 70 for opening and closing the pilot valve 62 is provided. The drive unit 70 is slidably mounted on a bearing body 71 provided above the pilot valve 62 and includes a rod 72 with the other-direction centerline Q as its axis, the tip of which is constantly in contact with the pilot valve 62.
[0036] Furthermore, the drive unit 70 is equipped with a control diaphragm 73 that contacts the base end of the rod 72 and presses and releases the rod 72 by the pilot pressure on the secondary chamber 14 side. The control diaphragm 73 is housed in an operating chamber 74 provided above the bearing body 71 of the upper body 10. The operating chamber 74 consists of a pressure receiving chamber 75 that receives the pilot pressure on the secondary chamber 14 side, and a spring chamber 76 that houses a second spring 77, which is a coil spring that is separated by the control diaphragm 73 and constantly presses the control diaphragm 73 with a predetermined biasing force. 78 is an adjustment unit that adjusts the biasing force of the second spring 77 and sets the pilot pressure to a predetermined pressure. In Figure 2, reference numeral 79 denotes a pilot pipe that supplies pilot pressure from the pipeline on the secondary chamber 14 side and downstream of the outlet 3 to the pressure receiving chamber 75.
[0037] As a result, when the pilot pressure falls below a set predetermined pressure, the biasing force of the second spring 77 causes the control diaphragm 73 to press against the rod 72, the rod 72 presses against the pilot valve 62, the pilot valve 62 opens the pilot valve port 68, and opens the operating pipeline 61. When the operating pipeline 61 is open, the fluid in the primary chamber 13 is supplied to the lower chamber 32 of the operating chamber 30 of the operating diaphragm 18 through the operating pipeline 61 (communication passage 65 → valve chamber 64 → first pipe 66). When fluid is supplied to the lower chamber 32 of the operating chamber 30, the operating diaphragm 18 advances the valve stem 20 against the biasing force of the valve body spring 21, and the valve body 17 opens the valve port 15, allowing the fluid to flow out from the primary chamber 13 through the valve port 15 to the secondary chamber 14 side.
[0038] On the other hand, when the pilot pressure exceeds a set predetermined pressure, the control diaphragm 73 is pushed up against the biasing force of the second spring 77, and the pressure on the rod 72 is released. As a result, the biasing force of the first spring 69 causes the pilot valve 62 to push up the rod 72, closing the pilot valve port 68 and closing the operating pipeline 61. When the operating pipeline 61 is closed, the supply of fluid to the primary chamber 13 is stopped, and the fluid in the lower chamber 32 of the operating chamber 30 of the operating diaphragm 18 is released to the secondary chamber 14 through the relief pipeline 63 (second pipe 67). This causes the operating diaphragm 18 to retract the valve stem 20 due to the biasing force of the valve body spring 21, closing the valve port 15 with the valve body 17, and stopping the outflow of fluid from the primary chamber 13 to the secondary chamber 14.
[0039] Therefore, according to the valve device S of this embodiment, it operates as follows. In Figure 2, P1 is the primary side pressure (set value), P2a is the pilot pressure (set value), P2b is the pressure of the secondary chamber 14, P3 is the pressure of the lower chamber 32, and P4 is the pressure of the upper chamber 31. The operating diaphragm 18 is activated by the differential pressure (P3-P4) between the pressure of the lower chamber 32 and the pressure of the upper chamber 31. That is, when the pilot pressure falls below a set predetermined pressure, the control unit 60 opens the operating pipe 61, and the fluid from the primary chamber 13 is supplied to the lower chamber 32 of the operating chamber 30 of the operating diaphragm 18 through the operating pipe 61. The operating diaphragm 18 advances the valve stem 20 against the biasing force of the valve body spring 21, and the valve body 17 opens the valve port 15, causing the fluid to flow out from the primary chamber 13 to the secondary chamber 14 through the valve port 15. On the other hand, if the pilot pressure exceeds a set predetermined pressure, the control unit 60 closes the operating pipeline 61, stopping the fluid supply to the primary chamber 13. The operating diaphragm 18 then retracts the valve stem 20 due to the biasing force of the valve body spring 21, causing the valve body 17 to close the valve port 15, stopping the outflow of fluid from the primary chamber 13 to the secondary chamber 14. As a result, the fluid pressure on the secondary chamber 14 side is maintained at a predetermined pressure lower than the fluid pressure on the primary chamber 13 side.
[0040] In this valve device S, when the pressure on the secondary chamber 14 side falls below a predetermined pressure, the valve body 17 opens the valve port 15, allowing fluid to flow from the primary chamber 13 through the valve port 15 to the secondary chamber 14 side. At this time, when the fluid from the primary chamber 13 side is ejected from the valve port 15 into the secondary chamber 14, the fluid is directed towards one end opening Ra of the passage R. However, this one end opening Ra is formed so as not to be opposed to the ejection direction of the fluid ejected from the valve port 15. In this embodiment, it is formed outside the ejection region E of the fluid ejected from the valve port 15 to the secondary chamber 14 side. Therefore, the situation in which the ejected fluid flow directly hits one end opening Ra of the passage R and attempts to flow into the upper chamber 31 of the working chamber 30 is prevented, and as a result, fluctuations in the pressure difference between the upper chamber 31 and the lower chamber 32 of the working chamber 30 can be made extremely small.
[0041] Furthermore, the opening of the bearing 40 of the valve stem 20 faces the direction of fluid ejection, and the ejected fluid flow into the secondary chamber 14 attempts to enter through the gap between the valve stem 20 and the bearing 40. However, the bearing 40 has a sealing portion 50 with a sealing member 51 that the valve stem 20 slides against, which prevents fluid from entering from the sliding portion of the valve stem 20. In this respect as well, fluctuations in the pressure difference between the upper chamber 31 and the lower chamber 32 of the working chamber 30 can be made extremely small. In this case, in the sealing portion 50, multiple sealing members 51 are pressed and held in place via a retaining ring 57 by screwing in a nut 56, so that the seal between the valve stem 20 and the bearing 40 is secure, and the entry of fluid from the sliding portion of the valve stem 20 can be reliably prevented, thus reliably achieving fluctuation prevention.
[0042] As a result, the operation of the operating diaphragm can be stabilized, preventing so-called hunting, and the wear of the valve body 17 itself and its sliding parts can be reduced, thereby improving durability. In particular, since the seal member 51 that the valve stem 20 slides against is heat-resistant, deformation of the seal member 51 can be prevented when the fluid is high-temperature steam, and the wear of the sliding parts of the valve stem 20 and bearing 40 is further reduced, thereby improving durability. In this case, since the opening Ra at one end of the passage R is not blocked, communication between the secondary chamber 14 and the upper chamber 31 of the operating chamber 30 is ensured by the passage R, and therefore the normal operation of the operating diaphragm is not affected.
[0043] Figure 5 shows a valve device S according to another embodiment. This differs from the valve device S described above in how the passage R is provided. Specifically, in this valve device S, the passage R is provided on the valve stem 20. More specifically, multiple one-end openings Ra of the passage R are formed on the side surface of the valve stem 20, and multiple other-end openings Rb of the passage R are formed on the side surface of the valve stem 20. The one-end openings Ra and the other-end openings Rb are connected by through holes 80 drilled from the other end of the valve stem 20 along the axis of the valve stem 20. The one-end openings Ra have an axis perpendicular to the axis of the valve stem 20, and are formed so as not to face the direction of ejection even in the ejection region E of the fluid ejected from the valve port 15 to the secondary chamber 14. As a result, since the passage R is formed on the valve stem 20, its processing can be made easier and the structure can be simplified. Other functions and effects are the same as described above.
[0044] Figure 6 shows a valve device S according to another embodiment. This differs from the valve device S described above in how the passage R is provided. Specifically, in this valve device S, a rod 81 is provided in the secondary chamber 14, erected on the partition wall 7. The passage S is formed in the rod 81 and has an opening Ra at one end on its tip side. one One side passage 82 and the other end opening Rb formed in the partition wall 7 Others that possess It is configured with a side passage 83. The one-end opening Ra is formed so as not to face the direction of ejection, even in the ejection region E of the fluid ejected from the valve port 15 to the secondary chamber 14. As a result, the passage S can be formed by creating the rod 81 in advance and attaching it to the partition wall 7, making it easy to construct the passage S. Other functions and effects are the same as described above.
[0045] Figure 7 shows yet another embodiment of the valve device S. This differs from the valve device S described above in how the passage R is provided. Specifically, in this valve device S, the passage R is formed in the wall of the main body 1. Specifically, the passage R is formed in the pipe body 4 and has one end opening Ra on the outlet 3 side. one One side passage 84 and the other end opening Rb formed in the partition wall 7 Others that possessIt is configured with a side passage 85. The one-end opening Ra is formed outside the ejection region E of the fluid ejected from the valve port 15 to the secondary chamber 14. This valve device S also produces the same functions and effects as described above.
[0046] In the embodiment shown in Figure 2 above, in which a passage R is formed in an externally provided pipe 36, the one-end opening Ra is provided on the wall of the connecting pipe 33 connected to the outlet 3. However, it is not limited to this, and may be provided on the wall of the pipe body 4 constituting the main body 1 near the outlet 3, and can be modified as appropriate. Furthermore, although the above embodiment shows an example of applying the present invention to a pressure reducing valve, it is not limited to this, and of course, the present invention can be applied to any valve device S of the type in which the valve body 17 is actuated by a valve stem 20 linked to an operating diaphragm 18, forming a passage R and acting the operating diaphragm 18. Moreover, the present invention is not limited to valve devices S for steam, but may also be applied to valve devices S for high-temperature fluids other than steam. In short, those skilled in the art can easily make many modifications to these exemplary embodiments without substantially departing from the novel teachings and effects of the present invention, and many of these modifications are included within the scope of the present invention. [Explanation of Symbols]
[0047] S valve device 1 Main unit 2 entrance 3 exit P One-way center line Q Center line in other direction 4. Body 5. Lower opening 6. Upper opening 7 Bulkhead 8 Lower body 10 Upper body 11 Base Wall 12 Partition walls 13 Primary room 14 Secondary room 15 valve openings 16 Valve sac 17 Valve body 18. Operating diaphragm 20 valve stems 21 Valve body spring 22 Spring retainer 30 Working chamber 31 Upper chamber 32 Lower chamber 32a Inlet R aisle Ra open at one end Rb other end opening E Ejection area 33 connecting pipes 34 Outlet flange 35 Connection flange 36 pipes 37 Adapters 38 Corn 40 bearings 41 Through hole 42 Male threaded section 43 Base 44 Female thread section 50 Seal part 51 Sealing member 52 Holding part 53 Storage compartments 54 Male screw 55 Female thread 56 nuts 57 Retaining ring 60 Control Unit 61 Operating pipeline 62 Pilot valve 63 Relief pipeline 64 valve chambers 65 Communication path R 66 First Pipe 67. Second pipe 68 Pilot valve port 69 First Spring 70 Drive unit 71 Bearing body 72 rods 73 Control diaphragm 74 Operating room 75 Pressure-receiving room 76 Spring Chamber 77 2nd Spring 78 Adjustment section 79 Pilot tube 80 through hole 81 Rod 82 One-sided aisle 83 Other side aisle 84 One-sided aisle 85 Other side aisle
Claims
1. The valve comprises a main body having an inlet and an outlet, forming a fluid passage through which fluid flows; the main body is provided with a primary chamber on the inlet side and a secondary chamber on the outlet side, formed by partitioning the passage with a partition wall; a valve opening through which fluid can pass is formed in the partition wall; a valve body for opening and closing the valve opening is provided in the primary chamber; a valve stem is provided on the secondary chamber side, one end of which supports the valve body and the other end of which is connected to an operating diaphragm; the main body is provided with an operating chamber separated from the secondary chamber by a partition wall facing the valve opening, in which the operating diaphragm is housed; the operating chamber is composed of an upper chamber on the partition wall side and a lower chamber partitioned by the operating diaphragm; and the valve stem is provided so as to penetrate the partition wall so as to be able to move back and forth. In a valve device in which a passage is provided with one end opening to the secondary chamber and the other end opening to the upper chamber of the operating chamber, the valve stem is moved back and forth via the operating diaphragm by the pressure difference between the fluid flowing from the secondary chamber through the passage to the upper chamber of the operating chamber and the fluid in the lower chamber, the valve body opens and closes the valve port, A bearing on which the valve stem can slide is provided in the above-mentioned partition wall, and a seal portion having a heat-resistant sealing member that the valve stem slides against is provided in the bearing. A valve device characterized in that one end opening of the above passage is formed so as not to face the direction of ejection of the fluid ejected from the valve port toward the secondary chamber.
2. The valve device according to claim 1, characterized in that the above passage is provided with one end opening in the wall of the main body near the outlet or in the wall of the connecting pipe connected to the outlet, and the one end opening and the other end opening are connected by a pipe that is routed outside the main body.
3. The valve device according to claim 1, characterized in that the above passage is provided on the above valve stem.
4. The valve device according to claim 3, characterized in that one end opening of the above passage is formed on the side surface of the valve stem, the other end opening of the above passage is formed on the side surface of the valve stem, and the one end opening and the other end opening of the passage are connected by a through hole drilled from the other end of the valve stem along the axis of the valve stem.
5. The valve device according to claim 1, characterized in that a rod is provided in the secondary chamber above, erected on the partition wall above, and the passage is configured to include one side passage formed on the rod and having the one end opening at its tip, and the other side passage formed on the partition wall and having the other end opening.
6. The valve device according to any one of claims 1 to 5, characterized in that the sealing portion comprises a plurality of overlapping ring-shaped sealing members that slide against the valve stem, and a holding portion that is connected to the secondary chamber side of the bearing and protrudes into the secondary chamber, and houses and holds the plurality of sealing members in an overlapping manner, the holding portion comprises a housing having a support surface for supporting the lower sealing member of the plurality of sealing members and a recess having an inner surface that can contact the outer surface of each sealing member, a nut having an insertion hole through which the valve stem is inserted and a female thread that screws onto a male thread formed on the outside of the housing, and a retaining ring that is inserted onto the valve stem and provided on the upper sealing member of the plurality of sealing members, and presses and holds the plurality of sealing members when the nut is screwed onto the male thread.
7. The valve device according to claim 6, characterized in that a male threaded portion is formed on the outer circumference of the bearing, and a female threaded portion is formed in the partition wall into which the male threaded portion is screwed, and the bearing is provided in the partition wall by screwing the male threaded portion into the female threaded portion.
8. The primary chamber is provided with a valve spring that biases the valve body in the retraction direction of the valve stem and in the direction that closes the valve opening, and a control unit that controls the operation of the operating diaphragm is provided, and the control unit is configured to include an operating pipeline provided between the primary chamber and the lower chamber of the operating chamber, and a pilot valve provided in the middle of the operating pipeline that opens the operating pipeline when the pilot pressure on the secondary chamber side falls below a predetermined pressure and closes the operating pipeline when the pilot pressure exceeds the predetermined pressure, The valve device according to claim 6, characterized in that when the pilot valve of the control unit opens the operating pipeline, the operating diaphragm advances the valve stem against the biasing force of the valve body spring, opening the valve port with the valve body, and allowing fluid to flow from the primary chamber through the valve port to the secondary chamber, and when the pilot valve of the control unit closes the operating pipeline, the operating diaphragm retracts the valve stem due to the biasing force of the valve body spring, closing the valve port with the valve body, and stopping the outflow of fluid from the primary chamber to the secondary chamber.