JP2002005310A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a ring contacting a hub seal ring in a butterfly valve. SOLUTION: This butterfly valve is provided with a seat 12 formed around a circumference of a disk-like valve element 11, and a boss 13 formed on a center part of the valve element 11 to accommodate a valve rod 22. The boss 13 is formed in a large size than the seat 12 along a thickness direction of the valve element 11. A part wherein the seat 12 intersecting the boss 13 is formed as a recessed part 17 wherein neither the seat 12 nor the boss 13 exists. The hub seal ring 29 is positioned around the valve rod 22 accommodated in the boss 13 through the recessed part 17. A tip part of the hub seal ring 29 is constituted in such a manner to be got into the recessed part 17 and capable of pressing against and coming into contact with the inner circumference thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a butterfly valve.

[0002]

2. Description of the Related Art A butterfly valve has a disk-shaped valve element, and the valve element is rotated around a valve rod to open and close the valve. 2 to 5 show an example of a configuration of a valve body of a conventional concentric butterfly valve. As shown in the figure, the disc-shaped valve body 11 is formed in a hollow convex lens shape having a thick central portion and a thin peripheral portion, and a pointed sheet 12 is formed on the peripheral edge. A boss 13 for accommodating a valve stem is formed in the center of the valve body 11 along the radial direction of the valve body 11. This boss 13
Is formed with a size larger than the sheet 12 along the thickness direction of the valve body 11.

The seat 12 must be precisely machined to have a predetermined shape and dimensions in order to ensure a tight seal with the valve seat formed on the valve box of the butterfly valve. For this reason, generally, as shown in FIG.
The valve body 11 is horizontally supported on a rotary table 15 by leg portions 14 integrally formed of the same material, and the rotary table 15 rotates the horizontal valve body 11 about a vertical axis. As shown in FIGS. 4 and 5, the cutting tool 16 is applied to the periphery to perform machining.

At this time, since the dimension of the boss 13 along the thickness direction of the valve body 11 is larger than that of the seat 12 as described above, as shown by phantom lines in FIGS.
The boss 13 is provided at a portion where the sheet 12 and the boss 13 intersect.
Is present during the machining of the sheet 12, the cutting tool 16
Interfere with the boss 13. Therefore, in order to avoid such interference, the intersection between the sheet 12 and the boss 13 is formed as a concave portion 17 where the boss 13 is not formed.
Since the valve stem is housed inside the boss 13, in order to avoid interference with the valve stem, the boss 1 is provided at the intersection.
Not only the sheet 3 but also the sheet 12 is not formed.

FIG. 6 shows a configuration of a main part of a butterfly valve using such a valve element 11. Here, 21 is a valve box, 2
2 is a valve stem. A cylindrical bearing 23 is interposed between the valve stem 22 and the valve box 21. 24 is a bearing bush, 25
Is a packing. A rubber valve seat 2 is provided on the inner periphery of the valve box 21.
6 are provided. A rubber lining layer 1 for contacting the valve seat 26 is provided on the outer periphery of the sheet 12 of the valve body 11.
8 are formed.

[0006] Before the valve body 11 is housed in the valve box 21, a ring 27 is fitted into the recess 17, and the recess 17 is filled. The ring 27 is fixed to the boss 13 by a bolt 28, and is machined thereon so that the end face is formed in a flat shape. A hub seal ring 29 is provided between the bearing 23 and the ring 27 along the axial direction of the valve stem 22. When the hub seal ring 29 is pressed against the end face of the ring 27 on the valve body 11 side, the penetrating portion of the valve rod 22 is sealed from the fluid inside the valve box 21.

[0007]

However, as described above, the recess 17 must be provided to escape the cutting tool 16. Therefore, if a separately manufactured ring 27 is not fitted into the recess 17, it must be mounted. A seal surface in contact with the hub seal ring 29 cannot be formed.

Accordingly, an object of the present invention is to improve such a conventional butterfly valve so that a ring for contact with a hub seal ring may not be used.

[0009]

To achieve this object, the present invention provides a seat formed on the periphery of a disc-shaped valve element,
A boss formed at the center of the valve body for accommodating the valve stem, the boss is formed with a dimension larger than the sheet along the thickness direction of the valve body, and the seat and the boss in the valve body are In a butterfly valve in which an intersecting portion is formed as a concave portion having neither a seat nor a boss, a hub seal ring is disposed around a valve stem passing through the concave portion and housed in the boss, and a tip portion of the hub seal ring is formed as It is configured so as to be able to penetrate and press against the inner edge thereof.

With such a configuration, the concave portion functions as an escape portion when machining the seat portion of the valve body. However, a distal end portion is formed on the hub seal ring, and the distal end portion is formed as a concave portion. Are pressed into contact with each other so that the through portion of the valve shaft can be sealed by the pressed portion. That is, the penetrating portion of the valve stem can be reliably sealed without filling the recess with a ring, which is a separate component.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with respect to a butterfly valve according to an embodiment of the present invention, the same members as those shown in FIGS. ,
This will be described in detail. That is, the concave portion 17 is formed from the top of the seat 12 in the valve body 11 to a position where the concave portion 17 enters the boss 13 to a certain depth along the axial direction of the boss 13. In other words, the recess 17 has an inner edge formed only in the portion of the sheet 12 where the sheet 12 is formed along the circumferential direction. That is, the inner edge is formed only at two positions 180 degrees apart from each other along the circumferential direction. In contrast,
In the portion of the boss 13, since the boss 13 is cylindrical, an inner edge is formed over the entire circumference. The inner edge of the concave portion 17 is formed in a tapered shape whose diameter increases outward. The sheet 12 is provided on the inner surface of the recess 17.
A lining layer 31 made of rubber is formed so as to be continuous with the lining layer 18 on the outer periphery.

A hub seal ring 29 provided at the tip of the bearing 23 is formed so as to enter the recess 17. A rubber lining layer 32 is formed on the outer periphery of the hub seal ring 29. It is preferable that the surface of the lining layer 32 is treated with, for example, a fluorinated ethylene resin. The outer periphery of the distal end portion of the hub seal ring 29 formed by the lining layer 32 is formed in a tapered shape capable of contacting the inner edge of the concave portion 17.

[0013] The hub seal ring 29 is tightened with a bolt or the like for fixing the bearing 23 to the valve box 21.
It is pressed in the axial direction. Then, based on this pressing force, the tapered tip portion is pressed against the inner edge of the concave portion 17. As a result, the space between the recess 17 and the hub seal ring 29 is sealed over the entire circumference.

At this time, since the sealing is performed by pressing the tapered surfaces, a reliable sealing effect can be achieved with only a small pressing force by the wedge effect. Instead of performing the pressure contact by such a tapered surface, a structure in which the distal end surface of the hub seal ring 29 and the rear end surface of the recess 17 are pressed against each other, or another sealing structure may be employed.

Therefore, according to the above configuration, since the tip of the hub seal ring 29 fits into the recess 17 to seal the two, a separate member such as a ring for filling the recess 17 is used. Without the stem 22
Can be reliably sealed. Therefore, the number of parts can be reduced, and it is not necessary to machine the internal threads for the bolts for fixing the ring as in the case of using the conventional ring, and therefore, the number of machining steps can be reduced. Further, since it is not necessary to process the end face of the ring after attaching the ring as in the related art, the number of processing steps can be reduced from this point as well.

[0016]

As described above, according to the present invention, in a butterfly valve in which a portion of a valve body where a seat and a boss intersect is formed as a concave portion having neither a seat nor a boss.
A hub seal ring is arranged around the valve stem housed in the boss through the recess, and the tip of the hub seal ring is
Because it is configured so that it can enter the recess and press against the inner edge,
The through-hole of the valve stem can be sealed by this press-contact portion, so that the through-hole of the valve stem can be reliably sealed without filling the recess with a ring, which is a separate component.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a butterfly valve according to an embodiment of the present invention.

FIG. 2 is a front view of a valve body of a conventional butterfly valve.

FIG. 3 is a plan view of the valve body of FIG. 2;

FIG. 4 is a view showing a state in which the seat of the valve body shown in FIGS. 2 and 3 is machined;

FIG. 5 is a perspective view showing how the seat portion of the valve body is machined.

FIG. 6 is a sectional view of a main part of a conventional butterfly valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Valve body 12 Seat 13 Boss 17 Recess 22 Valve stem 29 Hub seal ring

Claims (1)

[Claims] 1. A valve having a seat formed on a peripheral edge of a disc-shaped valve element and a boss formed at a central portion of the valve element for accommodating a valve stem. A butterfly valve formed with a larger dimension than the seat along the valve body, and a portion where the seat and the boss intersect in the valve body is formed as a concave portion where neither the seat nor the boss exists, and the valve is housed in the boss through the concave portion A butterfly valve, wherein a hub seal ring is disposed around a rod, and a distal end portion of the hub seal ring is configured to be able to enter a recess and press against an inner edge thereof.