JP2549234Y2 - Butterfly valve seat ring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve, and more particularly, to a seat ring of a center type butterfly valve having a valve stem disposed at a rotation center of a valve body.

[0002]

2. Description of the Related Art Conventionally, a valve body is rotatably arranged in a cylindrical valve body by pivotally supporting a valve rod about its rotation center, and a soft elastic material such as rubber provided on an inner peripheral surface of the valve body. 2. Description of the Related Art A center type butterfly valve which opens and closes a flow path by contacting and separating a seat ring made of a material and a valve body is known.

In such a butterfly valve, a rubber seat ring (3) moves as shown in FIG. 7 in response to a pressure of a flowing fluid or a contact pressure caused by opening and closing of a valve element. As shown in Fig. 8, the viscoelasticity of rubber makes the seat ring
It is known that the surface layer and the inside of (3) are displaced, and as a result, the sealing performance is impaired and the opening / closing torque of the valve body (2) increases.

Therefore, as shown in FIG. 9, a groove (4) is formed on the inner peripheral surface of the valve body (1), and a projection (5) fitted into the groove (4) is formed on the outer peripheral surface of the seat ring (3). ) Has been proposed, and the shapes of the grooves and projections have been proposed to be modified as in JP-A-55-86965 and JP-A-60-220271. Although the movement of the seat ring itself can be suppressed by the fitting of the groove and the projection, the displacement inside the seat ring cannot be prevented.

As a means for preventing the deviation inside the seat ring, as shown in FIG. 10, there has been proposed a structure in which a rigid backup material is annularly embedded inside the seat ring. The structures disclosed in JP-A Nos. 52-98229 to 98231 and 60-111170 aim at the same effect. However, if an annular rigid body is embedded inside the seat ring, it becomes impossible to twist or bend the seat ring and incorporate it into the valve body, and a complicated structure for assembly such as dividing the valve body into two parts is required. Comes needed.

[0006] The structure disclosed in Japanese Patent Application Laid-Open No. 63-135,666 is to allow the seat ring to be bent while a reinforcing material is inserted inside the seat ring. When viewed, since the reinforcing material is intermittently arranged, the sealing point of the valve body to be sealed becomes intermittent, and a difference in the compression ratio partially occurs. As a result, there is a disadvantage that the performance of the sealing performance is reduced.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to effectively prevent the inside of the seat ring from being displaced while maintaining the flexibility of the seat ring, and also to improve the sealing performance. Is what you do.

[0008]

Means for Solving the Problems To solve the above-mentioned problems, a means adopted by the present invention is to dispose an annular seat ring on the inner peripheral surface of a cylindrical valve body, and provide an inner peripheral surface of the seat ring. In a central butterfly valve in which a valve body that comes in contact with and separates from the valve body is pivotally supported in a valve body by a valve rod at the center of rotation, a stud is provided in a seat ring, and the stud is removed from a seal point of the seat ring. It is characterized in that a plurality are arranged at intervals in the circumferential direction.

[0009]

[Operation] The studs arranged intermittently in the inner circumferential direction of the seat ring can prevent the inside of the seat ring from being displaced, and since it is intermittent, there is no possibility that the flexibility is impaired.
Moreover, since the embedded studs are arranged so as to avoid the sealing point with the valve body, there is no possibility that the sealing property is deteriorated. The movement of the seat ring is reliably prevented by fitting the projection provided on the outer peripheral surface of the seat ring with the groove on the inner peripheral surface of the valve body.

[0010]

According to the present invention, the internal displacement and movement of the seat ring can be effectively prevented without impairing the ease of incorporation into the valve body, and the sealing performance can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. In the figure, (10) is a seat ring according to the present invention, which is an annular member formed of a soft elastic material such as rubber, and is in contact with the outer peripheral surface of the valve body (17) at the center of the inner peripheral surface. A middle and high part (11) for providing a sealing property is projected in the circumferential direction. Flanges (12) are formed on both sides of the outer peripheral surface so as to fit on both sides of the valve body (15), and projections ( 13) is formed.

Further, a valve shaft hole (14) through which a valve stem (18) is inserted is bored at a diametrically opposed position of the seat ring (10). The shape and structure of the seat ring (10) are as follows. Conventionally known.

This invention is characterized in that a thin cylindrical stud (19) is disposed inside the seat ring (10). Tack (19)
Are arranged so as to extend in the diameter direction, and are arranged at appropriate intervals in the circumferential direction. The studs (19) are arranged so as to avoid the seal point (20) where the seat ring (10) and the valve element (17) come into pressure contact with each other to provide a seal, and the seal point ( A difference is not caused in the compression ratio of 20). In the illustrated embodiment, the studs (19) are arranged at intervals of four in the width direction of the seat ring (10), and the length of the studs (19) differs according to the arrangement position. However, this is merely an example and not a limitation. The studs (19) are buried in the seat ring (10) or driven in from the outside.

The material of the tack (19) may be any material as long as it is a rigid body capable of preventing the internal deviation of the seat ring (10) and does not adversely affect the material of the seat ring (10). Metal or hard plastic can be used.

Since the studs (19) disposed in the seat ring (10) are intermittently arranged, they do not interfere with the elastic bending property, so that the entire seat ring is twisted or bent. And can be incorporated into the valve body (15). Tack
Due to the presence of (19), the seat ring (10) does not undergo internal displacement even when subjected to stress at the time of pressure contact with the valve body (17),
The fitting of the projection (13) and the groove (16) also prevents the seat ring (10) from shifting. In addition, since the stud (19) is arranged so as to be separated from the seal point with the valve body (17), there is no adverse effect on the sealing performance.

[Brief description of the drawings]

 FIG. 1 is a perspective view of the seat ring. FIG. 2 is an enlarged perspective view of a part of the seat ring. FIG. 3 is a front view of the seat ring. FIG. 4 is a cross-sectional view showing contact with the valve body. FIG. 7 is a cross-sectional view of a conventional seat ring. FIG. 8 is a cross-sectional view of a conventional seat ring. FIG. 9 is a cross-sectional view of a conventional seat ring.

[Explanation of symbols]

 (10) Seat ring (11) Mid-high section (12) Flange section (13) Projection (14) Valve shaft hole (15) Valve body (16) Groove (17) Valve (18) Valve stem (19) Tack

Claims (3)

(57) [Scope of request for utility model registration] An annular seat ring is disposed on an inner peripheral surface of a cylindrical valve body, and a valve body that comes into contact with and separates from the inner peripheral surface of the seat ring is pivotally supported in the valve body by a valve rod at the center of rotation. A butterfly valve, wherein a stud is disposed in a seat ring, and a plurality of the studs are arranged at intervals in a circumferential direction by removing a seal point of the seat ring. Seat ring. 2. The seat ring according to claim 1, wherein the studs are arranged at a plurality of intervals in a width direction of the seat ring. 3. The seat ring according to claim 1, wherein a projection that fits into a groove formed on an inner peripheral surface in the valve body is formed on an outer peripheral surface of the seat ring.