JPH11315956A - Fixing structure for valve box bearing cylindrial part and valve stem sealing bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase reliability by increasing productivity, protecting the environment of an assembling work site, facilitating assembling/disassembling and surely preventing the slackening or pulling-out of a valve stem sealing bush. SOLUTION: A washer 14 is fitted around a projected part 13 hexagonal in outer surface, which is provided to be projected in a valve stem sealing bush 6, and the rotation preventing parts 15 and 15 of the washer 14 are allowed to about to the rotation regulating surfaces 16A of projected parts 16 and 16 provided in a bearing cylindrical part 5 and t interfere each other. Further, the bearing cylindrical part 5 is covered with a washer presser 17 made of a synthetic resin, and the plurality of hooking parts 18, 18 and 18 of the washer presser 7 are elastically hooked in hooking grooves 5A recessed in the outer periphery of the bearing cylindrical part 5 in a horizontal direction. Thus, the washer 14 is pressed by an annular pressing part 17A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing structure for a valve case-side bearing cylinder portion and a valve shaft sealing bush applicable to a gate valve and the like.

[0002]

2. Description of the Related Art For example, as shown in FIG.
A valve case 1, a valve rod 2 and a valve body 3 are provided. The upper end opening of the valve box 1 is removably closed by a valve box cap 4, and a valve stem shaft sealing bush 6 screwed into a bearing cylinder 5 of the valve box cap 4 can freely rotate around the axis C <b> 2. The valve stem 2 is sealed. The valve stem 2 is provided with a flange portion 2A that protrudes radially outward, and thrust bearing members 7A and 7B are disposed on both axial sides of the flange portion 2A.

[0003] The upper end of the valve stem 2 protrudes above the valve box cap 4, where a head 2B having a polygonal cross section is formed. A lead screw (trapezoidal male screw) 2C is formed below the flange 2A toward the lower end.
A female screw top 8 screwed into C is incorporated at the upper end of the valve body 3. Therefore, by fitting a box spanner formed at the lower end of the opening / closing operation handle (not shown) into the head 2B having a polygonal cross section, and rotating the opening / closing operation handle in the forward and reverse directions, The valve body 3 moves up and down along the guide member 9 and can be held in a fully open state, a fully closed state, or an intermediate opening degree. In the figure, reference numeral 10 denotes an O-ring (seal ring), which is inscribed in the valve stem 2. An O-ring (seal ring) 11 is also provided between the bearing cylinder 5 and the valve stem shaft sealing bush 6. C1 indicates the axis of the valve box 1.

By the way, the head 2B having a polygonal cross section of the valve stem 2
When the operation handle box spanner is fitted to the valve body 3 and the valve body 3 is fully closed by, for example, rotating in the forward direction and tightening the valve body 2, an upward reaction force is generated on the valve rod 2. Since this upward reaction force is generated by the rotation of the valve stem 2 around the axis C2, the frictional force between the flange portion 2A and the upper thrust bearing member 7A and the friction force between the upper thrust bearing member 7A and the valve stem shaft sealing bush 6 are increased. A push-up force and a rotational force are applied to the valve shaft sealing bush 6 via frictional force, and a screw-in type gate valve in which the valve shaft sealing bush 6 is screwed into the bearing cylinder portion 5 of the valve housing 4 as shown in the figure. Then, the valve shaft seal bush 6 is
There is a possibility that the screw may be loosened in the screwed state.

For this reason, conventionally, the bearing cylinder portion 5 and the valve shaft sealing bush 6 in which a set pin or a set screw member 12 is attached to the inner peripheral portion of the bearing cylinder portion 5 and the outer peripheral portion of the valve shaft sealing bush 6 are used. The fixing structure is designed to prevent the valve stem shaft sealing bush 6 from loosening due to the rotational force.

[0006]

However, in the conventional fixing structure of the valve case side bearing cylinder and the valve stem shaft sealing bush, after the assembly work in which the valve stem shaft sealing bush is screwed into the valve case side bearing cylinder, The productivity is inferior because a blind hole for fitting the stop pin or a blind hole for screwing the set screw member must be provided by co-machining. Further, since the cutting powder is scattered by the co-machining work after the assembling work, the environment of the assembling work place is deteriorated. Furthermore, since the coating around the blind hole or blind screw hole is discolored due to thermal effects due to the execution of the cutting process,
Repair painting is required, further reducing productivity.
In addition, since the set pin or set screw member, the valve case side bearing cylinder and the valve stem shaft sealing bush, etc. are exposed, a small gap between the set pin or set screw member and the blind through hole or blind blind screw hole or the valve is provided. Rainwater, solid foreign matter, and the like enter into a small gap between the box-side bearing cylinder portion and the threaded portion between the valve shaft sealing bush and make it difficult to disassemble.

Accordingly, the present invention improves productivity, protects the environment of an assembly work place, and can easily assemble and disassemble, and also reliably prevents loosening and detachment of a valve stem sealing bush. It is another object of the present invention to provide a structure for fixing a valve case side bearing cylinder portion and a valve stem shaft sealing bush that can improve reliability.

[0008]

In order to achieve the above-mentioned object, the present invention provides a structure for fixing a valve case side bearing cylinder and a valve stem shaft sealing bush to a valve case side bearing cylinder and a valve case. A fixed structure with a valve shaft sealing bush that rotatably seals a valve stem provided with a valve element that is screwed into a side bearing cylinder portion around an axis thereof, wherein an axial outer end of the valve stem shaft sealing bush is provided. The outer surface surrounding the center hole at the portion and projecting in the axial direction is a polygonal projection, and the axially outer end surface of the valve stem shaft sealing bush is fitted to the polygonal projection and the valve box side bearing cylinder. The washer contacting both surfaces of the axially outer end surface of the portion and having a rotation preventing portion, and the washer interfering with the rotation preventing portion of the washer provided on the axially outer end surface of the valve case-side bearing cylinder portion. A rotation restricting portion for restricting rotation around the axis of the valve stem; and a seat detachably attached to a valve box side bearing cylinder. Is characterized in that it comprises a washer retainer to prevent disengaged of the seat gold presses the.

According to the present invention, even when a rotational force is applied to the valve stem sealing bush, the rotating force is applied to the projection having a polygonal outer surface protruding from the valve stem sealing bush. The washer is transmitted to the rotation restricting portion of the valve case-side bearing cylinder via the path of the rotation restricting portion provided on the washer, and the rotation restricting portion interferes with the rotation restricting portion, so that the washer rotates around the axis of the valve stem. , The rotation of the valve stem shaft sealing bush can be prevented. In addition, it is possible to prevent the washer from coming off from the projection of the valve stem shaft sealing bush by the washer presser, and to conceal a small gap in the threaded portion between the valve box side bearing cylinder and the valve stem shaft sealing bush. Therefore, it is possible to prevent rainwater, solid foreign matter, and the like from entering the small gap of the screwed portion.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. The structure of the valve box, the structure of the valve body, and the connection structure between the valve stem and the valve body are the same as those of the conventional example shown in FIG. The description is given with the same reference numerals. FIG. 1 is an enlarged longitudinal sectional view of a main part, and FIG. 2 is a plan view showing a state where a washer retainer is removed. An outer hexagonal projection 13 surrounds the projection 13. A washer 14 is fitted on the projection 13 and is placed on both the upper end face in the axial direction of the valve stem shaft sealing bush 6 and the upper end face of the bearing cylinder 5. As shown in FIG. 3, the washer 14 has a regular hexagonal center hole 14A whose outer surface fits the regular hexagonal projection 13 and a straight line CA parallel to a straight line C passing through the center O of the center hole 14A. C
A pair of rotation preventing portions 15, 15 formed by cutting the peripheral portion along B is provided.

On the other hand, as shown in FIG. 4, a straight line C parallel to a straight line C passing through the center O of the center hole is provided on the upper end surface of the bearing cylinder portion 5.
A pair of protrusions 16, 16 having a rotation regulating surface 16A rising along A, CB is provided. These protrusions 1
The opposing interval of the rotation restricting surfaces 16A at 6 and 16 is set to a value slightly larger than the opposing interval of the rotation preventing portions 15 and 15 at the washer 14, and as shown in FIG.
When the outer surface of the regular hexagonal center hole 14A protruding from the upper end of the valve stem shaft sealing bush 6 is fitted to the regular hexagonal projection 13, the rotation preventing parts 15, 15 The rotation restricting surface 16A is configured to contact and interfere with the rotation restricting surface 16A. The outer diameter of the upper end surface of the bearing cylinder 5 and the outer diameter of the washer 14 are set to substantially the same value.

On the other hand, the washer presser 17 shown in FIGS.
Is formed of a synthetic resin, has an annular pressing portion 17A protruding downward on the lower surface of the central portion in the radial direction, and has a hook portion 18 bent radially inward at, for example, three places on the outer peripheral edge. 18, 18 are provided (however,
In FIG. 1, only two hook portions 18 are shown), and the hook portions 18, 18 are provided on the outer periphery of the upper end portion of the bearing cylinder portion 5 with the valve rod 2 inserted through the center hole 17 </ b> B. The washer 17 is pressed against the washer 14 by an annular pressing portion 17A in a state where the washer 17 is put on the bearing cylinder 5 by being elastically removably engaged with the engaging groove 5A which is provided in the lateral direction.

In the assembled state shown in FIGS. 1 and 2 with the above-described configuration, even if a rotational force is applied to the valve shaft sealing bush 6 at the time of, for example, fully closing the valve body 3, this rotating force is applied to the valve shaft sealing. An outer surface protruding from the bush 6 has a hexagonal projection 13, a washer 14 externally fitted to the hexagonal projection 13, and a rotation preventing portion 15, 15 provided on the washer 14. It is transmitted to the rotation regulating surface 16A. The rotation preventing portions 15, 15 abut against the rotation restricting surfaces 16 </ b> A of the protrusions 16, 16 to interfere with each other, thereby restricting the rotation of the washer 14 about the axis C <b> 2 of the valve stem 2, and thereby controlling the valve stem axis. It is possible to reliably prevent the sealing bush 6 from rotating around the axis C2. Further, the washer 1 is provided by an annular pressing portion 17A of a washer presser 17 which is detachably hooked and mounted in a state of covering the bearing cylinder portion 5.
4 is pressed, it is possible to prevent the washer 14 from being detached upward in the axial direction. Therefore, the bearing cylinder 5
The reliability of the structure for fixing the valve stem and the valve shaft sealing bush 6 can be improved.

That is, according to the present invention, the valve stem shaft sealing bush 6 is attached to the bearing cylinder portion 5 like the conventional fixing structure of the valve case side bearing cylinder portion and the valve shaft sealing bush described with reference to FIG. It is not necessary to provide a blind through hole for fitting a set pin or a blind through hole 12 for screwing a set screw member after the screwed assembly work by co-machining. For this reason, productivity can be improved and the cutting powder is not scattered during the assembling work, so that the environment of the assembling work place can be protected. Furthermore, since the cutting process can be omitted, discoloration of the coating film due to thermal influence can be avoided, so that repair painting is not required, which can further improve productivity.

In addition, the washer 14 has a center hole 14A corresponding to an upper surface of a regular hexagonal projection 13 provided on the valve shaft sealing bush 6 and a pair of rotation preventing parts 15, 15 formed in a bearing cylinder. A pair of protrusions 16, 1 provided on the upper end surface of the portion 5
6 In a state corresponding to the respective rotation regulating surfaces 16A, the assembling is completed by simply dropping, and the washer presser 17 is inserted into the center hole 17B of the valve stem 2 and the retaining groove 5A of the bearing cylinder 5 is formed. A plurality of hooks 18, 18,
By pressing down in this state, each of the plurality of engaging portions 18, 18, 18 is brought into sliding contact with the outer peripheral surface of the bearing tube portion 5, and once elastically expanded outward in the radial direction. After that, by further pushing down, a procedure for elastically hooking the respective hooking portions 18, 18, 18 individually into the hooking grooves 5A, that is, assembling is completed by a simple operation of simply pushing down, so that assembly is completed. It is easy to disassemble because the washer presser 17 and the washer 14 can be removed by the reverse procedure at the time of assembly.

Further, the bearing cylinder 5 is provided by a washer presser 17.
A small gap between the screwing portion (screw portion) 20 between the screw shaft portion and the valve shaft sealing bush 6 is concealed, so that rainwater and solid foreign matter can be prevented from entering the small gap between the screwing portion 20 and screwing. Since the rusting of the portion 20 can be avoided, the disassembly work for removing the valve shaft sealing bush 6 from the bearing cylinder portion 5 at the time of maintenance and inspection of the gate valve can be facilitated.

In the above-described embodiment, a projection 13 having a regular hexagonal outer surface protrudes from the upper end in the axial direction of the valve stem shaft sealing bush 6, and a regular hexagonal center hole 14 A fitted externally to the projection 13 is provided. Although the explanation is made using the washer 14, a polygonal protrusion having a shape of a triangle or more protrudes from the upper end in the axial direction of the rod shaft sealing bush 6, and a triangle which can be fitted to the polygonal protrusion having the shape of the triangle or more. A washer 14 having the above-described polygonal center hole may be used. Further, the number of corners of the center hole 14A of the washer 14 that is fitted to the polygonal protrusion having a shape of a triangle or more of the valve stem sealing bush 6 is limited to only the same number of angles as the number of the outer surfaces of the polygonal protrusion 13. Instead, a central hole may be formed in which outer fitting corners (see FIG. 5) corresponding to an integral multiple of the number of corners of a polygonal projection of a triangle or more are formed at equal intervals in the circumferential direction.

As a specific example, in the case where the projection 13 having a regular hexagonal outer surface protrudes from the valve stem shaft sealing bush 6 as described above, as shown in FIG. Can be used. The washer 14 is provided with a center hole 14A in which twelve outer fitting corner portions 21, 21... By using such a washer 14, the center hole 14A is made to correspond to the upper side of the projection 13 of the valve stem shaft sealing bush 6, and the pair of rotation preventing parts 15, 15 is formed on the upper end surface of the bearing cylinder part 5. If it is attempted to drop the pair of projections 16, 16 provided in such a manner as to correspond to the respective rotation restricting surfaces 16A, the rotation preventing portions 15, 15, and 1 of the washer 14 will be described.
Even if a relative displacement occurs in the circumferential direction with respect to the rotation restricting surface 16A of each of the pair of protrusions 16, 16, the relative displacement in the circumferential direction causes the valve stem shaft sealing bush 6 to move in the counter-screw direction. , And the outer fitting positions of the twelve outer fitting corners 21, 21,... With respect to the protrusion 13 of the valve stem shaft sealing bush 6 can be corrected by shifting one by one in the circumferential direction. 5, without significantly reducing the amount of screwing of the valve stem shaft sealing bush 6 into the washer 14.
Can be brought into contact with the rotation regulating surfaces 16A of the projections 16 and 16 to cause interference.

In the above-described embodiment, as shown in FIGS. 3 and 4, the washer 14 is provided with the center O of the center hole 14A.
A pair of rotation preventing portions 15, formed by cutting the peripheral portion along straight lines CA, CB parallel to the straight line C passing through
15 is provided, and the center O of the center hole is
Are provided with a pair of protrusions 16, 16 provided with rotation control surfaces 16A rising up along straight lines CA, CB parallel to the straight line C passing through, and as shown in FIG.
6A is configured to come into contact with and cause interference.
As shown in the figure, downward bent portions 14B are provided at, for example, a plurality of locations on the outer peripheral edge of the washer 14, and these bent portions 14B are fitted into grooves 16B formed in the upper end surface of the bearing cylinder portion 5. By combining, the bent portion 14
B, 14B are made to interfere with the grooves 16B, 16B, that is, the bent portions 14B, 14B function as the rotation preventing portions 15, 15 of the washer 14, and the arc-shaped groove 16
You may comprise so that B and 16B may function as a rotation control part similarly to the protrusion parts 16 and 16.

Further, in the above embodiment, the plurality of rotation preventing portions 15 and 15 and the protrusions 16 and 16 or the plurality of bent portions 14B and 14B and the grooves 16B and 16B are provided. The number of the portions 16, the bent portions 14B, and the arc-shaped grooves 16B may be one each.

[0021]

As described above, the present invention prevents the washer from rotating around the axis of the valve stem even when a rotational force is applied to the valve stem sealing bush at the time of fully closing the valve body. Regulate,
The rotation of the valve stem sealing bush can be reliably prevented. In addition, since the washer is pressed by the annular pressing portion of the washer presser which is detachably hooked and mounted in a state where the washer is put on the bearing cylinder portion, it is possible to prevent the washer from being detached upward in the axial direction. it can. Moreover, as in the conventional fixing structure of the valve body side bearing cylinder and the valve shaft sealing bush, after the assembly work, the blind through hole for fitting the set pin or the blind hole for screwing the set screw member is made by co-machining. Since there is no need to provide them, productivity can be increased, and the environment of the assembly work place can be protected because the cutting powder does not scatter during the assembly work. Furthermore, since the cutting process can be omitted, discoloration of the coating film due to thermal influence can be avoided, so that repair painting is not required, which can further improve productivity. On the other hand, assembling is completed by simply dropping the washer and assembling is completed by a simple operation of pressing down the washer presser, so that assembling is easy, and the washer presser and washer can be removed by a reverse procedure at the time of assembling. Therefore, the disassembly can be easily performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a plan view showing the washer presser shown in FIG. 1 with a washer removed;

FIG. 3 is a plan view showing an embodiment of a washer.

FIG. 4 is a plan view showing an embodiment of a bearing cylinder portion.

FIG. 5 is a plan view showing a modification of the center hole of the washer.

FIG. 6 is a cross-sectional view showing a modification of the rotation preventing section and the rotation restricting section.

FIG. 7 is a half-sectional vertical sectional side view showing a conventional valve open state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 2 Valve stem 3 Valve body 5 Bearing cylinder part (valve cylinder side bearing cylinder part) 6 Valve stem shaft sealing bush 6A Center hole 13 External hexagonal projection (polygonal external projection) 14 Washer 15 Rotation prevention part 16 Protrusion (rotation restriction part) 16A Rotation restriction surface (rotation restriction part) 17 Washer holder C2 Valve stem axis

Claims (1)

[Claims] 1. Fixing of a valve body side bearing cylinder portion and a valve stem shaft sealing bush for rotatably sealing a valve stem provided with a valve body which is screwed into the valve case side bearing cylinder portion around its axis. An axially outer end surrounding the center hole at an axially outer end of the valve stem shaft sealing bush, and an outer surface protruding in the axial direction. A washer contacting both surfaces of an axial outer end surface of a rod-shaft sealing bush and an axial outer end surface of the valve case-side bearing cylinder, and a washer provided with a rotation preventing portion, and an axial outer end surface of the valve case-side bearing cylinder. A rotation restricting portion provided to prevent rotation of the washer around the axis of the valve stem by interfering with a rotation blocking portion of the washer; and A valve case-side bearing cylinder portion and a valve stem shaft sealing block, comprising: a washer press for pressing the washer to prevent the washer from being removed. Fixed structure with the shoe.