Valve device

Abstract

To provide a valve device from which a cover can be easily removed, and in which a valve port can be easily cleaned when the cover is removed.SOLUTION: A valve device 1 comprises: a valve seat 101a on which a valve port 101c is formed; a valve body 55 which is seated on the valve seat from a first side in an axial line direction to the valve port separably in an axis line O1 direction of the valve port; a valve shaft 45 to which the valve body is fixed; a yoke 10 which is fixed to the valve seat and movably supports the valve shaft in an axial line direction; a first cover 70 which is fixed to the yoke; and a second cover 80 which is detachable from at least one of the first cover and the yoke, and covers a valve seat end 101d, which is an end on a first side in the axial line direction in the valve seat, from outside, where an end on a second side on the opposite side on the first side in the axial line direction in the first cover is arranged closer to the first side in the axial line direction than the valve seat end, and an end part on the first side in the axial line direction in the second cover overlaps the first cover in the axial line direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a valve device. [Background technology]

[0002] BACKGROUND ART Conventionally, a valve device has been used to open and close a pipe in a piping structure such as an agricultural water supply pipe (see, for example, Patent Document 1). The valve device of Patent Document 1 includes a valve seat and a valve body. The valve seat has a first frame and a second frame that are annular in plan view. A water intake pipe is disposed inside the first frame. A valve port is formed in the second frame. The second frame is fixed to the upper surface of the first frame.

[0003] The valve disc is seated on the valve seat so as to be releasable. The valve disc is disk-shaped in plan view. The lower surface of the outer periphery of the valve disc abuts against the upper surface of the second frame part of the valve seat, thereby closing the valve orifice. The valve disc moves upward away from the upper surface of the second frame part, thereby opening the valve orifice. When the valve opening is released, the water that flows through the valve opening in the valve seat hits the underside of the valve body and flows out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-159009 Summary of the Invention [Problem to be solved by the invention]

[0005] The water that hits the underside of the valve disc flows along the underside of the valve disc and may splash around the valve disc. To prevent the water from splashing, the valve device may be equipped with a cover that covers the valve seat, valve disc, etc. from the outside. The cover is fixed to a yoke or the like that movably supports the valve stem fixed to the valve disc. In this case, the water splashing off the valve body hits the cover and flows downward. However, if the cover is fixed to a yoke or the like, it becomes difficult to clean the valve port.

[0006] The present invention has been made in consideration of the above problems, and has as its object to provide a valve device in which the cover can be easily removed and the valve port can be easily cleaned when the cover is removed. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention proposes the following means. a valve seat having a valve orifice formed therein; a valve disc seated on the valve seat from a first axial side relative to the valve orifice so as to be movable in the axial direction of the valve orifice; a valve stem to which the valve disc is fixed; a yoke fixed to the valve seat and supporting the valve stem so as to be movable in the axial direction; a first cover fixed to the yoke; and a second cover detachable from at least one of the first cover and the yoke and covering from the outside a valve seat end which is the end of the valve seat on the first axial side, wherein an end of the first cover on the second axial side opposite to the first axial side is positioned closer to the first axial side than the valve seat end, and an end of the second cover on the first axial side overlaps with the first cover in the axial direction.

[0008] In this invention, for example, the valve device is arranged so that the valve seat side (second axial side) of the valve disc faces downward. In the valve device, the valve stem supported by the yoke can be moved axially relative to the valve seat, and the valve disc can be seated on the valve seat from the first axial side (upper side) so as to be movable axially. The valve seat end of the valve seat is covered from the outside by the second cover, and the end of the second cover on the first axial side (upper side) overlaps with the first cover in the axial direction. As a result, water that flows out of the valve opening of the valve seat, hits the valve disc, and changes direction toward the outside is prevented from flowing outward between the first and second covers, thereby preventing the water from splashing around the valve disc. Furthermore, while the first cover is fixed to the yoke, the second cover is detachable from at least one of the first cover and the yoke. Therefore, the second cover can be easily removed from the valve device. When the second cover is removed, the end of the first cover on the second axial side (lower side) is positioned on the first axial side (upper side) of the valve seat end. Therefore, for example, the first cover is less likely to get in the way when an operator extends their hand toward the valve orifice, making it easy to clean the valve orifice.

[0009] In the valve device, an end portion of the second cover on the first side in the axial direction may be fitted from outside into an end portion of the first cover on the second side in the axial direction. In this invention, the end portion of the second cover on the first side (upper side) in the axial direction can be easily fitted from the outside into the end portion of the first cover on the second side (lower side) in the axial direction.

[0010] In addition, in the valve device, the second cover may have a plurality of cover pieces that are arc-shaped when viewed in the axial direction, and the ends of the plurality of cover pieces on the first side in the axial direction may each be fitted from the inside into the ends of the first cover on the second side in the axial direction. In this invention, the cover pieces are arranged inside the first cover in a state where they are elastically deformed so that the radius of the cover pieces is reduced, for example. Then, by elastically restoring the shape of the cover pieces, the end of the second cover on the first side (upper side) in the axial direction can be easily fitted from the inside to the end of the first cover on the second side (lower side) in the axial direction.

[0011] In the valve device, a pair of the cover pieces adjacent to each other around the axis may partially overlap each other in a direction intersecting the axis. In this invention, the water can be prevented from flowing out of the pair of cover pieces through the gap between the pair of cover pieces adjacent to each other around the axis. [Effects of the Invention]

[0012] In the valve device of the present invention, the cover can be easily removed, and the valve port can be easily cleaned when the cover is removed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a partially cutaway front view of a valve device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a partially cutaway side view of the valve device. [Figure 3] FIG. 6 is a partially cutaway front view of a valve device according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a partially cutaway front view of a valve device according to a third embodiment of the present invention. [Figure 5] 5A and 5B are diagrams illustrating a fitted state of the first cover and the second cover of the valve device. [Figure 6] FIG. 10 is a partially cutaway front view of a valve device according to a fourth embodiment of the present invention. [Figure 7] FIG. 2 is a partially cutaway side view of the valve device. DETAILED DESCRIPTION OF THE INVENTION

[0014] (First embodiment) A first embodiment of a valve device according to the present invention will be described below with reference to FIGS. 1 and 2, a valve device 1 of this embodiment is used to open and close a pipe 101 that constitutes a piping structure 100 such as an agricultural water supply pipe. The pipe 101 is formed into a cylindrical shape from a synthetic resin such as polyvinyl chloride resin. Although not shown, the piping structure 100 has, in addition to the pipe 101, a manhole body that houses the piping structure 100, a water supply pipe for supplying the water (water) in the manhole body to the farm field, and the like.

[0015] The valve device 1 includes a valve seat 101a, a yoke 10, a valve stem 45, a valve body 55, a first cover 70, and a second cover 80. The valve seat 101a is the end of the pipe 101. That is, the valve seat 101a is cylindrical. A groove 101b is formed around the entire outer periphery of the valve seat 101a. The valve seat 101a is formed with a valve port 101c. The valve port 101c is the conduit of the pipe 101 at the end of the pipe 101.

[0016] Here, the valve seat 101a and the second cover 80 are formed in a cylindrical shape, the valve stem 45 is formed in a rod shape, the valve element 55 is formed in a disk shape, and the first cover 70 is formed in a top-closed cylindrical shape. The central axes (axial lines) of the valve seat 101a, the valve stem 45, the valve element 55, the first cover 70, and the second cover 80 are arranged coaxially with a common axis. Hereinafter, the common axis will be referred to as axis O1. The axis O1 is also the axis of the valve port 101c. For example, the valve device 1 is disposed so that the axis O1 is aligned in the vertical direction and the valve seat 101a side relative to the valve body 55 is downward (the second side in the direction of the axis O1). Note that the valve device 1 may also be disposed so that the axis O1 is inclined relative to the vertical direction. When the valve device 1 is viewed from above and below, the direction perpendicular to (intersecting with) the axis O1 is called the radial direction, and the direction going around the axis O1 is called the circumferential direction. Hereinafter, the upper end (first side in the direction of the axis O1, opposite to the second side in the direction of the axis O1) of the valve seat 101a will be referred to as a valve seat end 101d.

[0017] The configuration of the yoke 10 is not particularly limited as long as it can be fixed to the valve seat 101a and can support the valve stem 45 movably in the direction of the axis O1. For example, the yoke 10 has a support base 11, a plurality of legs 12, and a base portion 13. The support base 11 has a plurality of support pieces 16A, 16B and a connecting member 17. In this embodiment, the configuration of support piece 16A and the configuration of support piece 16B are identical to each other. Therefore, the configuration of support piece 16A is indicated by adding the capital letter "A" to the number or number and lowercase letter of the symbol. The configuration of support piece 16B corresponding to support piece 16A is indicated by adding the capital letter "B" to the same number or number and lowercase letter of the symbol of support piece 16A. This avoids redundant explanation. For example, a support plate 20A of the support piece 16A and a support plate 20B of the support piece 16B, which will be described later, have the same configuration. The same applies to the legs 12A, 12B, etc., which will be described later.

[0018] The support piece 16A has a support plate 20A, a flange 21A, and a seat portion 22A. The support plate 20A has a rectangular shape in plan view, and has a semicircular notch 20aA formed on one side (hereinafter referred to as the notch side) of the outer periphery of the support plate 20A in plan view. The support piece 16A has a plurality of (three in this embodiment) flanges 21A. The plurality of flanges 21A protrude in the thickness direction (downward) of the support plate 20A from three of the four sides of the support plate 20A that do not have the notch 20aA formed thereon. The seat portions 22A are provided at both ends of the cutout side. Note that one of the pair of seat portions 22A is not shown. In the following, there are cases where only a portion of the multiple components is shown, such as the pair of seat portions 22A. A through hole (not shown) is formed in the seat portion 22A. The seat portion 22A is a member for attaching the connecting member 17 to the support plate 20A.

[0019] The peripheral edge of the notch 20aA in the support plate 20A is fitted into the groove 101b in the valve seat 101a. The seat portion 22A of the support piece 16A and the seat portion 22B of the support piece 16B face each other. In this specification, facing also means being in contact with each other. In this embodiment, the support pieces 16A and 16B have the same shape. That is, in the valve device 1, the support pieces 16A and 16B allow for commonality of parts. The support pieces 16A and 16B sandwich the valve seat 101a in the left-right direction, which is one of the radial directions. Hereinafter, the other radial direction, which is perpendicular to the left-right direction, will be referred to as the front-rear direction.

[0020] For example, the connecting member 17 includes a bolt and a nut (not shown). The shank of the bolt is passed through the through-hole of the seat portion 22A of the support piece 16A and the through-hole of the seat portion 22B of the support piece 16B. The nut is fitted onto the shank of the bolt. The head of the bolt and the nut sandwich the seat portions 22A and 22B in the left-right direction. In this manner, the support base 11 is fixed to the valve seat 101a on the radially outer side of the valve seat 101a. The valve seat 101 a protrudes upward from the support base 11 .

[0021] In this embodiment, the yoke 10 has a pair of legs 12A and 12B as the plurality of legs 12. The leg portion 12A extends upward from the support base 11. A cross section of the leg portion 12A perpendicular to the axis O1 is U-shaped. The leg portion 12A has a back plate 25A, a pair of side plates 26A, a first folded piece 27A, and a second folded piece 28A. The back plate 25A extends in the direction of the axis O1 and is disposed so that the thickness direction of the back plate 25A is along the left-right direction. A ridge 25aA extending in the direction of the axis O1 is formed on the surface of the back plate 25A on the axis O1 side. Each side plate 26A protrudes from each circumferential edge of the back plate 25A in the thickness direction (diametrically outward) of the back plate 25A. The pair of side plates 26A face each other in the front-rear direction. The pair of side plates 26A protrude downward beyond the back plate 25A.

[0022] Each of the first folded pieces 27A protrudes from the lower end of the side plate 26A toward the inside of the pair of side plates 26A. The pair of first folded pieces 27A are fixed to the support plate 20A of the support piece 16A (support base 11) with screws or the like. Each second folded piece 28A protrudes from the upper end of the side plate 26A toward the inside of the pair of side plates 26A.

[0023] Base 13 extends in the left-right direction and connects the tips of legs 12A and 12B. Base 13 has a back plate 31, a pair of side plates 32, a female screw member 33, and fixing plates 34 and 35. Back plate 31 and the pair of side plates 32 form a connecting portion 36. The back plate 31 extends in the left-right direction and is disposed so that the thickness direction of the back plate 31 is along the front-rear direction. Each side plate 32 protrudes in the thickness direction (forward) of the back plate 31 from each edge of the back plate 31 in the axis O1 direction. The pair of side plates 32 face each other in the axis O1 direction. Hereinafter, of the pair of side plates 32, the side plate 32 located lower will also be referred to as side plate 32A, and the side plate 32 located upper will also be referred to as side plate 32B. A through-hole (reference numeral omitted) penetrating in the direction of the axis O1 is formed in each side plate 32. The through-holes of the pair of side plates 32 are each formed on the axis O1.

[0024] The female screw member 33 has a screw body 38 and a flange portion 39 . The screw body 38 is cylindrical. An internal thread 38a is formed on the inner peripheral surface of the screw body 38. The screw body 38 is disposed in the through-holes of the pair of side plates 32 along the axis O1. The flange 39 is annular and protrudes radially outward from the lower end of the screw body 38 around the entire circumference of the screw body 38. The flange 39 contacts the side plate 32A from below the side plate 32A. The screw body 38 and the flange portion 39 that constitute the female screw member 33 are integrally formed from brass or the like. The female screw member 33 is supported by a support mechanism (not shown) so as to be rotatable about the axis O1 relative to the connecting portion 36 but not movable in the direction of the axis O1.

[0025] A through-hole (reference numeral omitted) is formed in the center of the fixed plate 34. The fixed plate 34 contacts the side plate 32A from below the side plate 32A. The fixed plate 34 is fixed to the side plate 32A. The flange 39 of the female screw member 33 is disposed within the through-hole of the fixing plate . A through-hole (reference numeral omitted) is formed in the center of the fixed plate 35. The fixed plate 35 contacts the side plate 32B from above the side plate 32B. The fixed plate 35 is fixed to the side plate 32B.

[0026] The valve shaft 45 is disposed on the axis O1. The valve shaft 45 has a shaft body 46, a small diameter portion 47, and a large diameter portion 48. The shaft body 46, the small diameter portion 47, and the large diameter portion 48 are each cylindrical. The shaft body 46, the small diameter portion 47, and the large diameter portion 48 are disposed coaxially in this order from top to bottom. A male screw (not shown) is formed on the outer circumferential surface of the shaft body 46. The male screw of the shaft body 46 is fitted into the female screw 38a of the female screw member 33. The outer diameter of the small diameter portion 47 is smaller than the outer diameter of the shaft body 46. The outer diameter of the large diameter portion 48 is larger than the outer diameter of the small diameter portion 47.

[0027] A handle 49 is connected to an upper portion of the valve shaft 45 via a known rotation suppressing portion (not shown). The handle 49 has a grip 49a and a shaft portion 49b. The handle 49a and the shaft portion 49b are arranged coaxially with the axis O1. The handle 49a is arranged higher than the shaft portion 49b. The outer diameter of the handle 49a is larger than the outer diameter of the shaft portion 49b. The grip 49a is the part of the handle 49 that is directly gripped by the operator. The shaft 49b is connected to the rotation suppression part. When the handle 49 is rotated in a first direction about the axis O1, the rotation suppression portion prevents the valve stem 45 from rotating about the axis O1, and the valve stem 45 moves downward relative to the yoke 10. On the other hand, when the handle 49 is rotated in a second direction opposite to the first direction about the axis O1, the rotation suppression portion prevents the valve stem 45 from rotating about the axis O1, and the valve stem 45 moves upward relative to the yoke 10. As described above, the yoke 10 supports the valve stem 45 so that the valve stem 45 is movable in the direction of the axis O1.

[0028] The valve element 55 has a valve body 56 , a protrusion 57 , and an attachment member 58 . The valve body 56 is a rectangular plate in plan view. The valve body 56 is arranged coaxially with the axis O1 and above the valve seat 101a. The lower surface of the valve body 56 is a facing surface 56a that faces the valve seat 101a in the direction of the axis O1. The facing surface 56a is flat. The upper surface of the valve body 56 is a non-facing surface 56b that is opposite the facing surface 56a of the valve body 56. An accommodation hole 56c is formed in the non-opposing surface 56b of the valve body 56. The accommodation hole 56c is formed on the axis O1. The accommodation hole 56c is cylindrical. The accommodation hole 56c does not penetrate the valve body 56 in the direction of the axis O1, but is formed only in the non-opposing surface 56b. The large diameter portion 48 of the valve shaft 45 is disposed within the accommodation hole 56c of the valve body 56. The large diameter portion 48 and the accommodation hole 56c are circumferentially engaged with each other by an engagement mechanism (not shown). That is, the valve shaft 45 is restricted from rotating around the axis O1 relative to the valve body 56.

[0029] A groove 56d is formed around the entire outer periphery of the opposing surface 56a. A sealing member 61 such as an O-ring is disposed in the groove 56d. The lower end of the sealing member 61 protrudes downward from the opposing surface 56a. The protrusion 57 is provided radially outward of the groove 56d (sealing member 61) on the outer circumferential edge of the opposing surface 56a. The protrusion 57 is annular, and is provided on the opposing surface 56a over the entire circumference around the axis O1. The protruding portion 57 protrudes downward beyond the opposing surface 56 a and the sealing member 61 .

[0030] A pair of ridges 62 extending in the direction of the axis O1 is formed on each of the left-right side surfaces of the valve body 56. That is, the valve device 1 of this embodiment includes two pairs of ridges 62, with each pair of ridges 62 forming one set. The pair of ridges 62 constituting each set are spaced apart in the front-to-rear direction. The ridge 25aA of the leg 12A is disposed between the pair of ridges 62 of one set, and the ridge 25aB of the leg 12B is disposed between the pair of ridges 62 of the other set. With this configuration, the valve element 55 is movable in the direction of the axis O1 relative to the yoke 10, but is restricted from rotating around the axis O1.

[0031] In this embodiment, the mounting member 58 has a first mounting piece and a second mounting piece (reference numerals omitted). Each mounting piece is plate-shaped. However, the shape of each mounting piece is not limited to a plate-like shape. The pair of mounting pieces may be integrally formed. Each mounting piece has a rectangular shape in plan view, and a semicircular notch (not shown) is formed on one side of the outer periphery of each mounting piece in plan view.

[0032] Each mounting piece is detachably attached to the non-opposing surface 56b of the valve body 56 with a bolt or the like. The small diameter portion 47 of the valve stem 45 is disposed in a notch in each mounting piece. The small diameter portion 47 and the notch in each mounting piece are circumferentially engaged by an engagement mechanism (not shown). In other words, the valve stem 45 is restricted from rotating around the axis O1 relative to the mounting member 58. The large diameter portion 48 of the valve stem 45 engages with the mounting member 58 from below, thereby restricting the valve stem 45 from moving upward relative to the valve body 56 . In this manner, the valve body 56 is fixed to the lower end of the valve shaft 45.

[0033] When the handle 49 is rotated in a first direction about the axis O1, the valve element 55 moves downward relative to the valve seat 101a, and the opposing surface 56a of the valve element 55 comes into contact with the valve seat 101a via the sealing member 61. The valve element 55 seats on the valve seat 101a. At this time, water does not flow through the valve opening 101c of the valve seat 101a, and the valve opening 101c is closed, resulting in a closed state. At this time, the protrusion 57 of the valve element 55 is positioned radially outward relative to the valve seat 101a so as to surround the valve seat 101a from the radially outer side. On the other hand, when the handle 49 is rotated in the second direction around the axis O1 from the closed state of the valve port 101c, the valve element 55 moves upward relative to the valve seat 101a, and the valve element 55 moves upward away from the valve seat 101a. At this time, the water flows through the valve port 101c of the valve seat 101a, and the valve port 101c enters an open state. As described above, the valve element 55 is seated on the valve port 101c from above so as to be movable away from the valve seat 101a in the direction of the axis O1.

[0034] The first cover 70 is formed in a cylindrical shape with a top. The first cover 70 has a top wall 71, an outer peripheral wall 72, and a flange 73 (a lower end portion of the first cover 70). The top wall 71 is disk-shaped and is disposed coaxially with the axis O1. A through-hole (not shown) is formed in the top wall 71 on the axis O1. The shaft 49b of the handle 49 is disposed in the through-hole of the top wall 71. For example, the top wall 71 is fixed to the connecting portion 36 of the yoke 10 with a bolt or the like.

[0035] The outer peripheral wall 72 is formed in a cylindrical shape and extends downward from the outer peripheral edge of the top wall 71. The flange 73 is formed in an annular shape and protrudes radially outward from the lower end of the outer peripheral wall 72. The flange 73 is formed on the outer peripheral wall 72 around the entire circumference of the outer peripheral wall 72. The lower end of the flange 73 (first cover 70) is disposed above the valve seat end 101d. The first cover 70, which has a top wall 71, an outer peripheral wall 72, and a flange 73, is integrally formed by, for example, pressing a stainless steel plate. The first cover 70 covers the upper portion of the yoke 10 from the radially outer side.

[0036] The second cover 80 has a first outer peripheral wall 81 and a flange 82 (the upper end portion of the second cover 80). The first outer peripheral wall 81 is formed in a cylindrical shape and is disposed coaxially with the axis O1. The flange 82 is formed in an annular shape and protrudes radially inward from the upper end of the first outer peripheral wall 81. The flange 82 is formed on the first outer peripheral wall 81 around the entire circumference of the first outer peripheral wall 81. The inner diameter of the first outer peripheral wall 81 is larger than the outer diameter of the flange 73 of the first cover 70 . The inner diameter of the flange 82 is smaller than the outer diameter of the flange 73 and larger than the outer diameter of the outer peripheral wall 72 . The second cover 80 having the first outer peripheral wall 81 and the flange 82 is manufactured in the same manner as the first cover 70 .

[0037] The flange 82 of the second cover 80 contacts the flange 73 of the first cover 70 from above the flange 73. The flange 82 of the second cover 80 is fitted (engaged) with the flange 73 of the first cover 70 from the radially outer side. The flange 82 of the second cover 80 overlaps with the first cover 70 in the direction of the axis O1. The second cover 80 covers the valve seat end 101d of the valve seat 101a and the valve body 55 from the radially outer side.

[0038] When the second cover 80 is moved upward relative to the first cover 70, the flanges 73, 82 are disengaged, and the second cover 80 can be removed from the first cover 70. On the other hand, when the second cover 80 is moved downward from above the first cover 70, the top wall 71 and outer peripheral wall 72 of the first cover 70 pass through the flange 82 of the second cover 80, and the flange 82 of the second cover 80 fits into the flange 73 of the first cover 70 from above the flange 73. As described above, the second cover 80 is detachable from the first cover 70.

[0039] In the valve device 1 configured as above, when the valve port 101c is in an open state, irrigation water that flows from the pipe 101 of the piping structure 100 into the manhole body through the valve port 101c is supplied to the field through the water supply pipe. On the other hand, when the operator detects that the water level (groundwater level) in the field is equal to or higher than a predetermined height, the operator closes the valve port 101c, thereby stopping the supply of water to the field.

[0040] As described above, in the valve device 1 of this embodiment, the valve stem 45 supported by the yoke 10 can be moved in the direction of the axis O1 relative to the valve seat 101a, and the valve disc 55 can be seated on the valve seat 101a from above so as to be movable in the direction of the axis O1. The valve seat end 101d of the valve seat 101a is covered from the outside by the second cover 80, and the flange 82 of the second cover 80 overlaps with the first cover 70 in the direction of the axis O1. Therefore, the water that flows out of the valve port 101c of the valve seat 101a, hits the valve disc 55, and changes direction toward the outside is prevented from flowing outward between the first cover 70 and the second cover 80, and splashing of the water around the valve disc 55 can be prevented. Furthermore, the first cover 70 is fixed to the yoke 10, but the second cover 80 is detachable from the first cover 70. Therefore, the second cover 80 can be easily removed from the valve device 1. When the second cover 80 is removed, the lower end of the first cover 70 is positioned above the valve seat end 101d, so that, for example, the first cover 70 is unlikely to get in the way when an operator extends their hand toward the valve orifice 101c, making it easy to clean the valve orifice 101c.

[0041] The flange 82 of the second cover 80 is fitted into the flange 73 of the first cover 70 from the radially outer side. Therefore, the flange 82 of the second cover 80 can be easily fitted into the flange 73 of the first cover 70 from the radially outer side.

[0042] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 3. The same components as those in the above embodiment are designated by the same reference numerals, and a description thereof will be omitted. Only the differences will be described. As shown in FIG. 3, the valve device 2 of this embodiment includes a second cover 120 instead of the second cover 80 in the valve device 1 of the first embodiment. The second cover 120 is formed in a cylindrical shape with a top. The second cover 120 has a top wall 121, a second outer peripheral wall 122, the flange 82, and the first outer peripheral wall 81. The top wall 121 is disk-shaped and is disposed coaxially with the axis O1. A through-hole 121a is formed on the axis O1 in the top wall 121. The inner diameter of the through-hole 121a is larger than the outer diameter of the grip 49a of the handle 49. The second outer peripheral wall 122 is formed in a cylindrical shape and extends downward from the outer peripheral edge of the top wall 121. The flange 82 protrudes radially outward from the lower end of the second outer peripheral wall 122 . .

[0043] The top wall 121, second outer peripheral wall 122, and flange 82 of the second cover 120 are fitted to the first cover 70 from the outside in the radial direction. The top wall 121, second outer peripheral wall 122, and flange 82 of the second cover 120 overlap with the first cover 70 in the direction of the axis O1. When the second cover 120 is moved upward relative to the first cover 70, the engagement is released, and the handle 49 passes through the through-hole 121a of the top wall 121, making it possible to remove the second cover 120 from the first cover 70. On the other hand, when the second cover 120 is moved downward from above the first cover 70, the handle 49 passes through the through-hole 121a of the top wall 121, and the top wall 121, second outer peripheral wall 122, and flange 82 of the second cover 120 engage with the first cover 70 from above the first cover 70. As described above, the second cover 120 is detachable from the first cover 70.

[0044] As described above, in the valve device 2 of this embodiment, the second cover 120 can be easily removed, and the valve port 101c can be easily cleaned when the second cover 120 is removed.

[0045] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 4 and 5. The same components as those in the previous embodiment are designated by the same reference numerals, and a description thereof will be omitted. Only the differences will be described. As shown in FIGS. 4 and 5, the valve device 3 of this embodiment includes a first cover 125 and a second cover 130 instead of the first cover 70 and the second cover 80 in the valve device 1 of the first embodiment. In the first cover 125, a flange 73 projects radially inward from the lower end of the outer peripheral wall 72 of the first cover 70. The flange 73 is formed on the outer peripheral wall 72 around the entire periphery of the outer peripheral wall 72.

[0046] The second cover 130 has a plurality of (two in this embodiment) cover pieces 131A, 131B. The cover pieces 131A, 131B are arc-shaped when viewed in the direction of the axis O1. The number of cover pieces that the second cover 130 has is not limited to two, and may be three or more. The cover piece 131A has a peripheral wall piece 132A and a flange piece (upper end portion of the cover piece) 133A. The peripheral wall piece 132A has an arc shape when viewed in the direction of the axis O1. The central angle of the peripheral wall piece 132A preferably exceeds 180°. The flange piece 133A protrudes radially outward from the upper end of the peripheral wall piece 132A and is formed on the peripheral wall piece 132A over the entire range of the peripheral wall piece 132A in the circumferential direction. The cover pieces 131A and 131B are adjacent to each other around the axis O1.

[0047] The flange piece 133A of the cover piece 131A contacts the flange 73 of the first cover 125 from above the flange 73. The flange pieces 133A and 133B are fitted to the flange 73 of the first cover 125 from the radially inner side. The circumferential ends of the cover pieces 131A and 131B overlap each other in the radial direction.

[0048] As described above, in the valve device 3 of this embodiment, the second cover 130 can be easily removed, and the valve port 101c can be easily cleaned when the second cover 130 is removed. Furthermore, for example, the cover pieces 131A, 131B are elastically deformed so that the radius of the cover pieces 131A, 131B becomes smaller, and then the cover pieces 131A, 131B are placed inside the first cover 125. Then, by elastically restoring the shape of the cover pieces 131A, 131B, the flange pieces 133A, 133B of the second cover 130 can be easily fitted into the flange 73 of the first cover 125 from the radially inner side.

[0049] The circumferential ends of the cover pieces 131A and 131B overlap each other in the radial direction, which prevents the water from flowing out radially outward from the cover pieces 131A and 131B through the gap between the cover pieces 131A and 131B. The circumferential ends of the cover pieces 131A and 131B do not have to overlap with each other in the radial direction.

[0050] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same components as those in the above embodiment are designated by the same reference numerals, and a description thereof will be omitted. Only the differences will be described. As shown in FIGS. 6 and 7, the valve device 4 of this embodiment includes a second cover 135 instead of the second cover 130 in the valve device 3 of the third embodiment. In this example, the first cover 125 does not necessarily have to have the flange 73. The second cover 135 is formed in an elliptical cylindrical shape. The outer diameter of the second cover 135 in the left-right direction is longer than the outer diameter in the front-rear direction. The second cover 135 has a plurality of (two in this embodiment) cover pieces 136A, 136B. The cover piece 136A has a known attachment / detachment mechanism 137A instead of the flange piece 133A of the cover piece 131A. The attachment / detachment mechanism 137A is attachable to and detachable from the leg portion 12A of the yoke . The attachment / detachment mechanism may be detachable from the first cover 125 and the leg 12A of the yoke 10, respectively.

[0051] As described above, the valve device 4 of this embodiment can achieve the same effects as the valve device 3 of the third embodiment.

[0052] Although the first to fourth embodiments of the present invention have been described above in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes modifications, combinations, deletions, etc. of the configurations within the scope of the gist of the present invention. Furthermore, it goes without saying that the configurations shown in each embodiment can be used in appropriate combinations. For example, in the first embodiment, the outer peripheral wall 72 of the first cover 70 and the first outer peripheral wall 81 of the second cover 80 are each formed in a cylindrical shape. However, these outer peripheral walls may be formed in polygonal tubular shapes corresponding to each other. For example, if the outer peripheral wall of the first cover is formed in a hexagonal tubular shape, the first outer peripheral wall of the second cover is also formed in a hexagonal tubular shape. The second to fourth embodiments are similar to the first embodiment.

[0053] The valve body 55 may not have the protrusion 57 and the attachment member 58 . The valve seat 101 a may be formed from a member other than the end of the pipe 101 . The valve device 1 may be provided with an automatic water supply valve, instead of the valve body 55, that automatically opens and closes the valve port 101c. [Explanation of symbols]

[0054] 1,2,3,4 valve gear 10 York 45 Valve stem 55 Valve body 70,125 1st cover 80,120,130,135 Second cover 101a Valve seat 101c Benguchi 101d Valve seat end 131A, 131B, 136A, 136B cover pieces O1 axis

Claims

1. a valve seat having a valve port formed therein; a valve body that is seated on the valve seat from a first side in the axial direction of the valve port so as to be movable in the axial direction of the valve port; a valve stem to which the valve body is fixed; a yoke fixed to the valve seat and supporting the valve stem movably in the axial direction; a first cover fixed to the yoke; a second cover that is detachable from at least one of the first cover and the yoke and that covers, from the outside, a valve seat end that is an end of the valve seat on the first side in the axial direction; Equipped with an end of the first cover on a second side opposite to the first side in the axial direction is disposed closer to the first side in the axial direction than the valve seat end; The valve device, wherein an end portion of the second cover on the first side in the axial direction overlaps with the first cover in the axial direction.

2. The valve device according to claim 1 , wherein an end portion of the second cover on the first side in the axial direction is fitted from outside into an end portion of the first cover on the second side in the axial direction.

3. the second cover has a plurality of cover pieces that are arc-shaped when viewed in the axial direction, The valve device according to claim 1 , wherein end portions of the cover pieces on the first side in the axial direction are fitted from inside to end portions of the first cover on the second side in the axial direction.

4. The valve device according to claim 3 , wherein a pair of the cover pieces adjacent to each other around the axis of the plurality of cover pieces partially overlap each other in a direction intersecting the axis.

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