JP2000088139A - Shaft seal part structure of valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the shaft seal part structure of a valve capable of holding a bush at a member on the valve casing side and eliminating screw machining in a paint spot. SOLUTION: A through-hole 14 in which a valve spindle 13 is inserted is formed in a valve casing cover 11, the peripheral edge of the through-hole 14 is formed at a seat part 15 supporting a flange part 13a formed at the valve spindle 13, and a bush 16 is arranged in a state to be fitted in the valve spindle 13. A bush housing part 17 disposed to surround the bush 16 is formed integrally with the valve casing cover 11 and O-rings 19a for the valve spindle 13 and the bush housing part 17 are arranged on the inner and outer peripheries of the bush 16. A radially externally protruding moving tongue part 20 is arranged at the peripheral edge part of the bush 16, and a radially internally protruding fixed tongue part 21 axially engaged with a moving tongue part 20 and a crawling part 22 allowing axial passage of a moving tongue part 20, are provided at the opening peripheral edge of the bush housing part 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for stopping water at a valve stem penetration portion of a gate valve or the like, and relates to a valve shaft sealing structure.

[0002]

2. Description of the Related Art As a structure of a shaft sealing portion in a conventional gate valve, for example, there is one as shown in FIG. In FIG. 7, a valve element 3 that moves in and out of the axial direction by screwing with a valve rod 2 is disposed inside a valve box cover 1 provided in a valve element storage portion of the valve box. The flange 2 a is received by the valve box lid 1 by the thrust collar 4. A bush 5 is fitted on the distal end side of the flange 2 a of the valve stem 2, and a packing box 6 is arranged so as to cover the bush 5. In the bush 5, O-rings 7 for stopping water between the valve stem 2 and the packing box 6 are arranged in annular grooves 5a and 5b provided on the inner peripheral surface and the outer peripheral surface. The packing box 6 is fixed to the valve box cover 1 with fixing bolts 8 at the flange portion 6a.
A gasket 6b is interposed between the gasket 6 and the valve box lid 1. Further, the packing box 6 is provided with a dust seal 9 for sealing between the packing box 6 and the valve stem 2, and a cap 10 is provided at the tip of the valve stem 2.

[0003]

In the construction described above, the packing box 6 for holding the bush 5 is fixed to the fixing bolt 8.
The packing box 6
In addition, a flange 6a for disposing the fixing bolt 8 on the valve box cover 1 is required, so that the shapes of the packing box 6 and the valve box cover 1 are inevitably increased, and the overall size of the valve is reduced. The above was an obstacle. Further, the reliability of rust prevention is improved by coating the entire surface of the valve box lid 1, but the screw hole of the fixing bolt 8 cannot be coated, and there is a problem that it takes time to cure this portion. Was.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a valve shaft sealing structure which can hold a bush in a valve box side member and does not require threading at a painted portion. I have.

[0005]

According to a first aspect of the present invention, there is provided a valve shaft sealing structure for a valve, wherein a valve stem is inserted into a canopy portion of a valve box lid mounted on a valve box. The through-hole is formed, and the periphery of the through-hole is formed in a seat for receiving the flange formed on the valve stem, and a bush is fitted and mounted on the distal end side from the flange of the valve stem, and the bush is surrounded. The bush storage part to be installed is formed integrally with the canopy part, the valve rod and the seal material for the bush storage part are arranged on the inner and outer circumferences of the bush, and a movable tongue projecting radially outward is provided on the peripheral edge of the bush. A fixed tongue projecting radially inward and engaging with the movable tongue in the axial direction, and a dive portion allowing passage of the movable tongue in the axial direction, at the peripheral edge of the opening of the bush housing portion. It is.

With the above construction, the bush housing for holding the bush has an integral structure with the canopy, and the movable tongue and the fixed tongue engage with each other to prevent the bush from coming off.
By consolidating the parts that require machine processing such as screw holes into the bush, the screw structure as a connecting means in the canopy part is eliminated, and the space such as the flange part for arranging screws is not required, and the size is reduced. In addition, the canopy part can be easily painted over the entire surface without leaving unpainted parts such as screw parts, and the reliability against rust can be increased. In addition, the height of the valve can be reduced by integrating the bush housing portion.

According to a second aspect of the present invention, there is provided a shaft sealing portion structure of a valve, wherein a detent bolt is provided on the movable tongue, and the detent bolt is allowed to pass through the fixed tongue in the axial direction of the bush. In which a notch portion to be locked is formed.

With this configuration, the bush is prevented from rotating with the valve stem. The shaft sealing portion structure of the valve according to the third aspect of the present invention is configured such that a ventilation hole that communicates the closed space surrounded by the bush and the bush housing portion around the valve stem to the outside is formed by the valve stem, the bush, and the bush housing portion. In any one of them, a plug is detachably provided at the opening of the ventilation hole.

In this configuration, when the bush is mounted, the plug is removed and inserted into the bush storage portion. At this time, the air in the closed space flows out to the outside through the ventilation holes, so that it can be easily mounted without being hindered by the air pressure in the closed space.

When the bush is used, the movable tongue is locked by the engagement of the movable tongue with the fixed tongue of the bush accommodating portion, and the movable tongue receives the pressure in the valve box leaking around the valve stem. Is pressed against the part. For this reason, when pulling out the bush from the bush storage portion, the plug is removed, and the pressure in the closed space surrounded by the bush and the bush storage portion around the valve stem is released to the outside through the ventilation hole, and the movable tongue portion is removed. By releasing the pressure contact state with the fixed tongue, the rotation of the bush is facilitated, and the engagement between the movable tongue and the fixed tongue is released to pull out the bush.

According to a fourth aspect of the present invention, there is provided a valve shaft sealing structure in which a cover covering an opening around a valve stem is detachably mounted on a top portion of a bush accommodating portion. With this configuration, it is possible to prevent foreign matter from entering through the opening of the bush housing portion, improve dustproofness, and increase the reliability of the shaft sealing portion.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, a valve box cover 11 constituting a canopy portion of a valve box is arranged so as to cover an opening of a valve body storage section of the valve box. Has been arranged.

A through hole 14 through which the valve rod 13 is inserted is formed in the valve box cover 11.
A seat portion 15 for receiving a flange portion 13a formed on the valve stem 13 is formed, and a thrust collar 15a is disposed on the seat portion 15. A bush 16 is fitted and mounted on the distal end side of the flange 13 a of the valve stem 13, and a bush housing portion 17 that surrounds and holds the bush 16 is formed integrally with the valve box cover 11.

The bush 16 has annular grooves 18a on the inner and outer peripheral surfaces, and an O-ring 19a for sealing between the valve rod 13 and the bush housing 17 is disposed in each annular groove 18a. The bush 16 has a dust seal 19b disposed in an annular groove 18b formed on the inner peripheral surface on the upper end side.

A movable tongue 20 protruding radially outward is provided at the peripheral edge at the upper end of the bush 16, and a movable tongue 20 protruding radially inward and movable in the axial direction is provided at the peripheral edge of the opening of the bush housing 17. A fixed tongue 21 engaging with the tongue 20,
A dive portion 22 is provided to allow the movable tongue portion 20 to pass in the axial direction.

The movable tongue 20 is screwed with a locking bolt 23 having a hexagonal hole. The fixed tongue 21 allows the rotation locking bolt 23 to pass in the axial direction of the bush 16, A notch 24 for locking the rotation stop bolt 23 is formed. A cap 25 is attached to the tip of the valve stem 13.

The operation of the above configuration will be described. In order to mount the bush 16, with the cap 25 and the locking bolt 23 removed, the valve rod 13 is fitted and inserted and pushed in the axial direction, and the movable tongue 20 is dipped in the opening of the bush housing 17. The bush 16 is disposed in the bush storage section 17 through the passage 22. Thereafter, the bush 16 is rotated about the axis to fix the movable tongue 20 to the fixed tongue 2.
1, are placed in the axial direction so as to overlap with each other, and the locking bolt 23 is attached and fixed to the movable tongue 20 through the notch 24 of the fixed tongue 21.

In this state, the thrust force applied to the valve rod 13 is received by the seat 15 of the valve box cover 11 and the movable tongue 20
The bush 16 is prevented from coming off by the engagement of the fixed tongue 21 with the fixed tongue 21 in the axial direction. In addition, the locking bolt 23 is inserted into the notch 2
Locking the bush 16 prevents the bush 16 from rotating.

FIG. 3 shows another embodiment of the present invention, in which a ventilation hole 31 surrounding the valve rod 13 and communicating the outside of the closed space A surrounded by the bush 16 and the bush housing portion 17 is formed. The plug 32 is formed on the bush 16, and the plug 32 is detachably provided at the opening of the ventilation hole 31.

With this configuration, when the bush 16 is mounted, the bush housing portion 17 is removed with the plug 32 removed.
Insert At this time, the air in the closed space A is
The bush 16 can be easily mounted without being hindered by the air pressure inside the closed space A.

In use, the bush 16 is prevented from coming off by the engagement of the movable tongue 20 with the fixed tongue 21 of the bush accommodating portion 17, and receives the pressure in the valve box leaking around the valve rod 13. The movable tongue 20 is fixed tongue 2
It is pressed against 1.

In the case where the packing 19a is replaced in a state where water is not interrupted, that is, in a state where water pressure acts inside the valve box,
The valve body 12 is fully opened, the valve body 12 is brought into contact with the upper inside surface of the valve box lid 11, and the thrust collar 15a is pressed against the seat 15 by the flange 13a to stop water. At this time, the pressure in the valve box remains in the closed space A, and the movable tongue portion 20 is in pressure contact with the fixed tongue portion 21, so that it is difficult to rotate the bush 16.

For this reason, when pulling out the bush 16 from the bush accommodating portion 17, the plug 32 is removed, the pressure in the closed space A is released to the outside through the ventilation hole 31, and the bush 16 is pushed down to allow the movable tongue portion 20 to move. The press-contact state with the fixed tongue 21 is released. As a result, the rotation of the bush 16 is facilitated, the engagement between the movable tongue 20 and the fixed tongue 21 is released, and the bush 16 is pulled out.

The ventilation hole 31 may be provided in the bush housing 17 as shown in FIG. 4, or may be provided in the valve rod 13 as shown in FIG. FIG. 6 shows another embodiment of the present invention, in which a cover 33 covering an opening around the valve rod 13 is detachably mounted on the top of the bush housing portion 17. The cover 33 is made of resin or rubber, has a projection 34 on the inner side surface of the lower peripheral edge, and is engaged with a groove 35 provided on the outer peripheral surface of the bush housing 17.

With this configuration, the cover 33 prevents foreign matter from entering through the opening of the bush housing portion 17 to enhance dustproofness, and prevents the foreign matter from impairing the water stopping property of the shaft sealing portion. , The reliability of the shaft seal is improved.

[0026]

As described above, according to the present invention, the bush accommodating portion for holding the bush is formed integrally with the valve box lid, and the movable tongue and the fixed tongue engage with each other to prevent the bush from coming off. By consolidating the parts that require machining, such as screw holes, into the bush, the screw structure as a connecting means in the valve box lid can be eliminated, and the space such as the flange part for arranging the screws is reduced. This is unnecessary, and the size can be reduced, and the valve box lid can be easily coated entirely without leaving unpainted portions such as screw portions, so that the reliability against rust can be increased.

Further, by providing a ventilation hole around the valve stem to communicate the bush and the closed space surrounded by the bush housing to the outside, the bush can be easily attached and detached. Furthermore, the cover is detachably mounted on the top of the bush storage section to prevent foreign matter from entering through the opening of the bush storage section, thereby improving dustproofness and improving the reliability of the shaft sealing section. Can be.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a shaft sealing portion structure according to an embodiment of the present invention.

FIG. 2 is a plan view of a coaxial sealing portion.

FIG. 3 is a longitudinal sectional view showing a shaft sealing portion structure according to another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a shaft sealing portion structure according to still another embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a shaft sealing portion structure according to still another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a shaft sealing portion structure according to still another embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing a conventional shaft sealing portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Valve box cover 12 Valve body 13 Valve rod 13a Flange part 14 Through hole 15 Seat part 16 Bush 17 Bush storage part 18a Annular groove 19a O-ring 20 Movable tongue 21 Fixed tongue 22 Diving part 23 Detent bolt 24 Notch 31 Ventilation hole 32 Plug body 33 Cover 34 Projection 35 Groove

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naomi Kasai 1-1-1, Nakamiya Oike, Hirakata City, Osaka Prefecture Inside Kubota Hirakata Manufacturing Co., Ltd. (72) Inventor Toshimitsu Kuraya 1-1-1, Nakamiya Oike, Hirakata City, Osaka Prefecture No. 1 Inside Kubota Hirakata Factory (72) Inventor Takayuki Miyazaki 1-12-19 Kitahorie, Nishi-ku, Osaka-shi, Osaka Prefecture Inside Kurimoto Ironworks Co., Ltd. (72) Inventor Yoshihito Naga 1 Kitahorie, Nishi-ku, Osaka-shi, Osaka No.12-19, Kurimoto Iron Works Co., Ltd.

Claims (4)

[Claims] 1. A through hole through which a valve stem is inserted is formed in a canopy portion of a valve box lid attached to a valve box, and a peripheral portion of the through hole is formed in a seat portion for receiving a flange formed in the valve stem. A bush is fitted and mounted on the tip end side from the flange of the valve stem, and a bush storage part disposed around the bush is formed integrally with the canopy part,
A valve rod and a sealing material for the bush storage portion are arranged on the inner and outer circumferences of the bush, and a movable tongue projecting radially outward is provided on a peripheral portion of the bush. A shaft sealing portion structure for a valve, comprising a fixed tongue projecting and engaging with a movable tongue in an axial direction and a dive portion allowing passage of the movable tongue in an axial direction. 2. The movable tongue is provided with a detent bolt, and the fixed tongue is formed with a notch for allowing the detent bolt to pass in the axial direction of the bush and locking in the radial direction. A valve shaft sealing structure according to claim 1. 3. A ventilation hole which communicates the closed space surrounded by the bush and the bush housing around the valve stem to the outside,
3. The valve shaft sealing structure according to claim 1, wherein the valve shaft is formed in any one of the valve stem, the bush, and the bush housing portion, and the plug is detachably provided in the opening of the ventilation hole. 4. The valve shaft seal according to claim 1, wherein a cover covering an opening around the valve stem is detachably mounted on a top portion of the bush housing portion. Part structure.