JPH08312833A - Gate valve - Google Patents

Abstract

PURPOSE: To carry out replacement work of a seal material such as the packing material in a packing box in a pressurizing condition without draining a fluid inside. CONSTITUTION: A gate valve is provided with a packing box B1, and the packing box B1 is provided with a first seal material 30 such as a packing material positioned so as to enclose the outer peripheral side of a valve rod 26 in the packing box main body 32, and a first seal material retaining member 44 for pushing the first seal material 30 from an upper side. A second seal material 33 is positioned on the down side of the first seal material 30 such as the packing material so as to enclose the outer peripheral side of the valve rod 26. The second seal material 33 is arranged so as to position a second seal material retaining member 36 for tightly fit on the outer peripheral surface of the valve rod 26 by push-pressing it from the upper side of the second seal material 33 between the side part outer surface of the first seal material and the inner surface of the packing box main body 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate valve.

[0002]

2. Description of the Related Art As shown in FIG. 5, a sluice valve includes a valve box B, a valve lid F that covers the upper portion of the valve box B, and a flow path of the valve box B. And a valve body (not shown) for opening and closing, and a valve rod 2 connected to the valve body.
By rotating the valve body in a predetermined direction or in the opposite direction with its central axis as a rotation center, the valve body is moved to the valve box B.
The channel is opened and closed in a direction substantially orthogonal to the channel to open or block the channel.

By the way, in the conventional sluice valve, the packing box 1 is provided above the valve lid F to prevent the fluid in the valve box B from spouting out of the valve lid F. That is, the packing box 1 is composed of a cylindrical main body portion 1a having an insertion hole Y through which the valve rod 2 is inserted in the center of the inner bottom portion, and a brim portion 1b provided on the outer periphery of the upper portion of the main body portion 1a. A box body is provided, and a plurality of stages of packing materials 4 are provided in the body portion 1a so as to surround the outer peripheral portion of the valve rod 2.
4 are arranged.

On the other hand, a packing pressing member 5 for pressing the packing materials 4 and 4 is arranged above the main body 1a of the packing box 1, and the packing pressing member 5 is provided.
Is fitted into the cylindrical main body 1a,
It is provided with a cylindrical holding body 5a having an insertion hole R for inserting the valve rod 2 in the central portion, and a brim portion 5b provided on the outer periphery of the upper portion of the cylindrical holding body 5a. Then, in the flange portion 5b of the packing pressing member 5 and the flange portion 1b of the packing box 1, through holes 5c, 5c and screw holes 1c,
1c are provided respectively, and these through holes 5c, 5c
And the screw holes 1c, 1c have male screw portions 7a, 7
The bolts 7 provided with b are passed through, and the male screw portions 7
Nuts 8 and 8 are fastened to a and 7a from above.

Therefore, the packing materials 4 and 4 in the body portion 1a of the packing box 1 are pressed toward the inner bottom portion of the body portion 1a by the holding body 5a of the packing holding member 5 to be packed around the valve rod 2. . As a result, the packing materials 4 and 4 in the main body 1a of the packing box 1 prevent the fluid substance from jetting out of the valve lid F through the insertion hole Y.

However, in the sluice valve, as described above, the packing materials 4 and 4 are packed around the valve rod 2 so that the valve rod 2 is
When is rotated, the packing materials 4 and 4 are worn and damaged. Therefore, after the packing materials 4 and 4 have been used for a certain period of time, it is necessary to replace them, but especially when the sluice valve is attached to a position lower than the river bottom, for example, during use. When the packing materials 4 and 4 are taken out from the main body 1a of the packing box 1,
Due to the fluid pressure of the fluid, the fluid flows through the insertion hole Y of the valve rod 2 and is jetted upward in the main body 1a of the packing box 1, and the packing materials 4 and 4 are refilled in such a state. Was difficult.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to keep the inside of the packing box in a pressurized state without removing the fluid material inside. An object of the present invention is to provide a sluice valve that enables replacement work of sealing materials such as packing materials.

[0008]

The sluice valve according to the present invention has the following constitution in order to achieve the above object. That is, the packing box is provided to prevent the fluid substance from being ejected through the insertion portion of the valve rod, and the packing box is placed inside the packing box body so as to surround the outer periphery of the valve rod. Also, a first seal material such as a packing material and a first seal material retainer that presses the first seal material from above is provided. A second sealing material is placed below the first sealing material so as to surround the outer circumference of the valve rod, and the second sealing material is pressed from above to closely contact the outer circumferential surface of the valve rod. A second seal member retainer is provided on the packing box for the purpose.

The second sealing material retainer is provided so as to be located between the outer surface of the side portion of the first sealing material and the inner surface of the packing box body, and on the inner surface of the packing box body. A female screw portion is formed, and a male screw portion that is screwed with the female screw portion is formed on the outer surface of the side portion of the second seal member retainer, while the male screw portion and the female screw portion are screwed together. By screwing in the second seal material retainer, when the second seal material retainer is in the pressing position, the second seal material retainer is pressed and adheres to the outer peripheral surface of the valve rod, and the second seal material retainer is screwed in. By loosening, when the second seal material retainer is in the non-pressing position, the pressure is relaxed and the second seal material does not adhere to the outer peripheral surface of the valve rod.

The second seal member retainer is composed of a cylindrical main body portion and a retainer portion provided in a lower portion of the main body portion and having a central portion having an insertion hole through which the valve rod is inserted. desirable. Further, it is preferable that a hooking portion for hooking a dedicated tool is provided on the outer periphery of the upper portion of the second seal member retainer.

[0011]

The second seal member is pressed from the upper side by the second seal member retainer so as to be in close contact with the outer peripheral surface of the valve rod and prevent the fluid from entering the packing box body.

Further, when the female thread portion on the inner surface of the packing box body and the male thread portion on the outer surface of the side portion of the second seal material retainer are screwed together and the second seal material retainer is screwed into the body of the packing box, (2) Since the pressing of the sealing material advances to the pressing position, the second sealing material is pressed and comes into close contact with the outer peripheral surface of the valve rod. As a result, the second seal material prevents the fluid substance from entering the packing box body.

On the contrary, if the screwing of the second sealing material retainer is loosened, the second sealing material retainer returns to the non-pressing position, the pressure of the second sealing material is relaxed, and the second sealing material retainer is released. Does not adhere to the outer peripheral surface of the valve rod.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the sluice valve of the present invention will be described below with reference to FIGS.

The sluice valve 12 is, for example, a valve rod rising type sluice valve, and as shown in FIG. 1, a valve box 14, a valve lid 16 covering the upper part of the valve box 14, and a flow path 18. It is equipped with a valve body 20 for opening and closing.
The valve rod 20 connected via the valve shaft 20 is moved up and down about its central axis as a center of rotation, thereby moving the valve body 20 up and down in a direction substantially orthogonal to the flow path 18 of the valve box 14. The flow path 18 is opened or closed.

A stand S is provided on the upper side of the valve lid 16, and an upper portion of the stand S has a manual handle H projecting to one side and an electric motor installed so as to project to the opposite side. Valve rod rotating part 2 consisting of M etc.
8 are provided. Further, insertion holes S1 and 16a, which are insertion portions, are formed at the top of the valve lid 16 and the center of the bottom of the stand S so as to communicate the inside of the stand S and the inside of the valve lid 16, respectively. , 16a,
The valve rod 26 is inserted into the valve lid 16 from inside the stand S.

Since the valve rod rotating portion 28 is connected to the valve rod 26 via a power transmission mechanism, an operator can rotate the handle H or drive the electric motor M. In this case, the valve rod rotating portion 28 rotates the valve rod 26 to move the valve body 20 up and down.

By the way, the sluice valve 12 is provided with a packing box B1 for preventing ejection of a fluid substance in the lower inside of the stand S as an example. As shown in FIG. 2, the packing box B1 is placed inside the packing box main body 32 so as to surround the outer periphery of the valve rod 26. For example, a first seal such as a plurality of stages of packing material is provided. Material 30
And the first seal member 30 is pushed from the upper side thereof.
The seal member holder 44 is provided.

Specifically, the packing box main body 32 comprises a cylindrical main body portion 32a formed by rising from the inner bottom portion of the stand S, and a brim portion 32b provided on the outer periphery of the upper portion of the main body portion 32a. , The cylindrical main body 32
In a, for example, a first packing material such as asbestos
The sealing material 30 is arranged vertically so as to surround the outer periphery of the valve rod 26.

The first seal member retainer 44 has a cylindrical retainer main body 44b having an insertion hole 44a for inserting the valve rod 26 in the center thereof, and an outer periphery of an upper portion of the cylindrical retainer main body 44b. The brim portion 44c is provided. Then, the brim portion 44c of the first seal member retainer 44
Also, a through hole 44 is formed in the brim portion 32b of the packing box body 32.
d and a screw hole T are provided respectively, and the through hole 44d and the screw hole T are provided with male screw portions 46a, 4a on both end sides.
Bolts 46, 46 provided with 6b are passed through, and the male screw portions 46a, 46a, 46b, 46b are fitted with nuts 48,
48, 50, 50 are tightened from above and below. Nut 5
By omitting 0 tightening, as in the conventional example shown in FIG.
The nut 48 may be tightened only on the upper end side of the bolt 46.

Therefore, the first sealing material 30 such as the packing material is attached to the inside of the packing box main body 32 by the lower end portion of the pressing main body 44b of the first sealing material presser 44, which will be described later. Since the first sealing material 30 such as the packing material is packed so as to be pushed toward the inner bottom portion of the valve 36, a large amount of fluids entering through the insertion holes 16a and S1 to the outside of the valve lid 16. Prevent spouting. However, this first seal member retainer 44
Is a pressure at which the first sealing material 30 such as a packing material does not completely adhere to the outer peripheral surface of the valve rod 26. It is preferable that the pressure is adjusted so that the first sealing material 30 is pushed toward the inner bottom portion of the second sealing material retainer 36 with a pressure that allows the first sealing material 30 to pass through. This is because the infiltrating fluid substance passing between the valve rod 26 and the first sealing material 30 alleviates the friction between them and prevents the deterioration of the first sealing material 30 as much as possible.

In addition, in the packing box B1, a second sealing material 33 is placed below the first sealing material 30 such as the packing material so as to surround the valve rod 26, and the second sealing material 33. The second seal member retainer 36 located between the outer side surface of the first seal member 30 such as the packing member and the inner surface of the packing box body 32 is pressed from the upper side to be brought into close contact with the outer peripheral surface of the valve rod 26. And are provided.

Therefore, the first sealing material 3 such as packing material is used.
When replacing 0, the first sealing material 3 such as packing material in use
Even if 0 is taken out from the packing box main body 32, when the second seal material 33 is pressed from the upper side by the second seal material retainer 36 and is in close contact with the outer peripheral surface of the valve rod 26, the fluid substance is packed. It is possible to prevent entry into the box body 32. That is, in the illustrated embodiment, the second
Since the sealing material 33 is made of, for example, soft synthetic rubber or other synthetic resin, it is elastically deformed by the pressing by the second sealing material retainer 36 and is brought into close contact with the outer peripheral surface of the valve rod 26, and the outer periphery of the valve rod 26 This is because the gap P1 provided between the surface and the inner surface of the second sealing material 33 is closed. At this time (when the first sealing material 30 such as a packing material is replaced), the valve rod 26 is in a stationary state, so that even if the second sealing material 33 comes into close contact with the outer peripheral surface of the valve rod 26, There is no concern about wear of the second sealing material 33.

Then, when the second sealing material retainer 36 moves upward from the pressed state in the packing box main body 32 to release the pressing of the second sealing material 33, the second sealing material 33 is shaped. Returns to its original state, and the outer peripheral surface of the valve rod 26 is no longer in close contact, and the gap P1 is formed again (state shown in FIG. 2).

More specifically, the second seal member retainer 36
Is composed of a cylindrical main body portion 36a and a pressing portion 34 provided in the lower portion of the main body portion 36a and having a central portion provided with an insertion hole Y1 through which the valve rod 26 is inserted. However, the second seal member retainer 36 does not necessarily need to be integrally formed with the body portion 36a and the retainer portion 34 as in the above-described embodiment, and for example, as shown in FIG. The part 34 may be formed as a separate body. In that case, it is desirable that the pressing portion 34 be made of gun metal, for example. Even if the main body portion 36a and the pressing portion 34 are separate bodies, when the second sealing material pressing member 36 moves up and down by a certain length, the pressing portion 34 also moves up and down along with the movement. However, as shown in FIG. 4, the pressing portion 34 may not necessarily interlock.

On the outer periphery of the brim portion 36b of the second seal member retainer 36, a plurality of notches D, D, etc. for hanging a dedicated tool are provided, and the packing box body 3 is provided.
Since the female screw portion 38 is formed on the inner surface of 2, and the male screw portion 40 that is screwed with the female screw portion 38 is formed on the outer surface of the side portion of the main body portion 36a of the second seal member retainer 36, While the male screw portion 40 and the female screw portion 38 are screwed together, a special tool (not shown) for tightening and removing is applied to the hooking portions of the notches D, D, and the second seal member retainer 36 is screwed. Can be crowded.

Therefore, when the second sealing material retainer 36 is located on the lower side in the packing box body 32, that is, when it is in the pressing position, the second sealing material 33 is pressed and the valve is pressed as described above. When the second sealing material retainer 36 is located on the upper side in the packing box body 32 by contacting the outer peripheral surface of the rod 26 and loosening the screwing of the second sealing material retainer 36, that is, the non-pressed position. When the pressure is on, the pressure is released, and the second seal material 33 does not come into close contact with the outer peripheral surface of the valve rod 26.

Of course, the second seal member retainer 36
Does not necessarily have to be configured as in the above embodiment, and may have another shape and structure as long as it can press the second sealing material 33 or loosen the pressing. Further, the relationship between the packing box main body 32 and the second seal member retainer 36 does not necessarily have to be the connection relationship by screws.

Incidentally, the female screw portion 3 of the packing box main body 32.
A play portion A1 in which a female screw is not formed below 8
Is provided, and an O-ring R1 is provided below the play portion A1 to prevent a fluid substance from entering the threaded portion between the female screw portion 38 and the male screw portion 40.

Next, in this embodiment, a method of mounting the first sealing material 30 such as packing material and the second sealing material 33 on the packing box main body 32, and a method of replacing the first sealing material 30 such as packing material. Will be described.

First, a method of mounting the first sealing material 30 and the second sealing material 33 such as packing material in the packing box main body 32 will be described. With the bolts 46, 46 standing on the brim portion 32b, The nuts 50, 50 are fastened to the male screw portions 46b, 46b from below. Then, the second sealing material 33 is placed so as to surround the outer circumference of the valve rod 26. However, after the second sealing material 33 is placed, the bolts 46, 46
May be erected on the brim portion 32b.

Then, the female screw portion 3 of the packing box main body 32
The second seal member retainer 36 is attached to the inside of the packing box main body 32 by screwing the male thread portion 40 of the second seal member retainer 36 onto the screw 8.

After that, the first sealing material 30 such as the packing material coated with grease for preventing seizure is attached to the valve rod 26.
Is inserted into the space between the outer peripheral surface of the second seal member holder 36 and the inner surface of the main body portion 36a of the second seal member retainer 36, and is placed so as to surround the valve rod 26. Then, the male screw portions 46a, 46 of the bolts 46, 46
With a being inserted into the insertion hole 44b of the first seal member retainer 44, the nuts 48, 48 are attached to the male screw portions 46a, 4
By tightening 6a from the upper side respectively, the first
The lower end portion of the sealing material retainer 44 presses the first sealing material 30 such as a packing material into the packing box body 32 from the upper side thereof.

After that, a dedicated tool for tightening and removing is hung on the hooking portions of the notches D, D, etc. of the second seal material holder 36 to rotate the second seal material holder 36 of the packing box body 32. By moving to the upper side, that is, the non-pressing position, the pressing of the pressing portion 34 with respect to the second sealing material 33 is loosened. This is because the second sealing material 33 may deteriorate if it is kept pressed for a long time. Therefore, when the first sealing material 30 such as packing material is not replaced, the pressing portion 34 is not pressed. Loosen the second sealing material 33
This is because it is necessary to prevent the deterioration of

Then, when a fluid substance flows through the sluice valve in a state where the pressure of the pressing portion 34 is loosened, the insertion holes 16a, S
The fluid substance penetrates into the packing box main body 32 through No. 1. This infiltrating fluid substance passes through the gap P1 and
As described above, it passes between the valve rod 26 and the first sealing material 30 such as a packing material, and further flows out of the packing box B1 through the insertion hole 44a of the first sealing material retainer 44.
If the left and right nuts 48, 48 are tightened loosely with respect to the male screw portions 46a, 46a, the amount of fluid passing between the valve rod 26 and the first sealing material 30 such as packing material increases. The passing amount of the invading fluid is adjusted by appropriately adjusting the tightening degree.

When the operator observes the state of the invading fluid flowing out through the insertion hole 44a, the pair of left and right nuts 48 and 4 for the male screw portions 46a and 46a are observed.
Since the biased tightening of 8 can be understood, the amount of the invading fluid flowing out can be the same around the valve rod 26.
The tightening degree of each nut 48, 48 is adjusted.

Next, a method of replacing the first seal material 30 such as packing material will be described. First, a special tool for tightening and removing is engaged with the notches D, D of the second seal material retainer 36. The second seal member retainer 36 is moved to the lower side of the packing box main body 32, that is, the pressing position by rotating the second seal member retainer 36 by rotating it. Then, the pressing portion 34 of the second sealing material pressing member 36 presses the second sealing material 33 against the inner bottom portion of the packing box B1 and closes the gap P1, so that the fluid substance enters the packing box B1. Prevent.

After that, the nuts 48, 48 are loosened and removed from the bolts 46, 46 standing on the brim 32b, and the first seal member retainer 44 is pulled out upward to be removed, and a packing is used with a tool. The used first seal material 30, 30 is pulled out from the second seal material retainer 36 in the box body 32 (see FIG. 3), and instead,
Put the new first sealing materials 30, 30 into the packing box body 32.
It is inserted into the second seal member retainer 36 inside. Then, by the procedure described above, the first sealing material 30 is pressed and fixed from the upper side of the packing box body 32 toward the upper surface of the pressing portion 34 by the lower end portion of the pressing body 44a of the first sealing material pressing member 44. To do.

The sluice valve according to the present invention is not necessarily limited to the above embodiment, and various modifications can be made. For example, the second sealing material 33 is made of a soft material as described above. It is preferably made of synthetic rubber or other synthetic resin, but it may be made of other materials such as soft natural rubber, and its shape, material and the like can be arbitrarily changed. In addition, the main body 32 of the packing box B1,
The first seal material retainer 44 and the second seal material retainer 36 are
A shape other than a cylindrical shape, for example, a rectangular tube shape may be used. Furthermore, the first sealing material 30 such as packing material may be an oil seal, and may be made of leather, hemp, or the like. Although it is preferable to pack them, this embodiment is not always necessary, and for example, one layer may be used. On the contrary, the second sealing material 33 may be packed in plural stages.

As a mechanism for raising and lowering the valve body 20, other than the valve rod raising type shown in the illustrated embodiment, the valve rod 26 does not move up and down but rotates at a fixed position so that only the valve body 20 moves up and down. The valve rod non-elevation type may be used. Further, the manual handle H or the electric motor M used as a part of the valve rod rotating portion 28.
Need not necessarily be both, and for example, a mechanism that utilizes the driving force of either one of both may be adopted. Further, the mounting position of the packing box B1 does not necessarily have to be provided on the valve lid as in the above-described embodiment, but may be mounted inside the valve lid, for example.

[0041]

As is clear from the above description, according to the sluice valve according to the present invention, the second sealing material is provided below the first sealing material such as the packing material and the second sealing material is provided. By pressing the sealing material with the second sealing material pressing member, the second sealing material can be brought into close contact with the outer peripheral surface of the valve rod, and the fluid substance can be prevented from entering the packing box body. Therefore, even if the first seal material is taken out of the packing box body, the fluid material does not enter the packing box body, and therefore the first seal material such as the packing material is not removed without draining the fluid material in the flow path of the valve box. Material replacement work becomes possible.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a gate valve according to the present invention in a partial cross section.

FIG. 2 is an enlarged sectional view showing a packing box portion of the sluice valve.

FIG. 3 is an enlarged cross-sectional view of a packing box portion with a first sealing material such as a packing material taken out.

FIG. 4 is a view corresponding to FIG. 2, showing another embodiment of the sluice valve according to the present invention.

FIG. 5 is an enlarged front view showing a cross section of a part of a conventional gate valve.

[Explanation of symbols]

12 Gate valve 26 Valve rod 30 First seal material such as packing material B1 Packing box 32 Packing box body 33 Second
Seal material 36 Second seal material holder 38 Female screw portion 40 Male screw portion 44 First
Sealing material retainer 16a, S1 insertion hole (insertion part)

Claims (2)

[Claims] 1. A sluice valve having a packing box for preventing a fluid substance from being jetted out through an insertion portion of the valve stick, wherein the packing box has an outer periphery of the valve stick in a packing box body. A first sealing material such as a packing material placed so as to surround the first sealing material, and a first sealing material retainer that pushes the first sealing material from above, and below the first sealing material. Has a second seal member placed so as to surround the outer circumference of the valve rod, and a second seal member pressing member for pressing the second seal member from the upper side to bring the second seal member into close contact with the outer peripheral surface of the valve rod. Is provided in the packing box. 2. The second seal material retainer is provided so as to be located between the side outer surface of the first seal material and the inner surface of the packing box body, and on the inner surface of the packing box body, A female screw portion is formed, and a male screw portion that is screwed with the female screw portion is formed on an outer side surface of the second seal member retainer. While the male screw portion and the female screw portion are screwed together, By screwing in the second seal member retainer, when the second seal member retainer is in the pressing position, the second seal member retainer is pressed and closely adheres to the outer peripheral surface of the valve rod,
Further, by loosening the screwing of the second seal material retainer, when the second seal material retainer is in the non-pressing position, the pressure is released and the second seal material does not come into close contact with the outer peripheral surface of the valve rod. The gate valve according to claim 1, wherein: