JP2575130Y2 - 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 disposed in a cylindrical valve body by pivotally supporting the valve body at a center of rotation thereof, 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 in the width direction as shown in FIG. 3 under the pressure of a flowing fluid or a contact pressure caused by opening and closing of a valve element. It is known that the surface layer or the inside of the seat ring (3) is displaced due to the viscoelasticity of the rubber, and as a result, the sealing performance is impaired and the opening / closing torque of the valve body (2) increases. I have.

Therefore, as shown in FIG. 4, 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). ) or is formed (Fig. 4 a),
A rigid plate (6) may be embedded in the seat ring (3) (see FIG. 4).
B), or to form engaging projections and recesses which mutually engages the contact surface of the seat ring (3) and the valve body (1) (Fig. 4 C), in the width direction of the seat ring (3) A device that prevents movement has been proposed, and is disclosed in, for example, JP-A-55-86965 and JP-A-60-220271.

[0005] However, when the seat ring made of a soft elastic material such as rubber is completely prevented from moving in the width direction at the time of contact with the valve body, the sealing performance is improved.
There is a problem that the torque for driving the valve element is increased, and an excessive force is required for driving the valve element. The conventional structure cannot sufficiently satisfy such contradictory elements.

[0006]

This invention allows the seat ring to move to some extent in the width direction at the time of contact with the valve body so that the torque required for driving the valve body is not increased more than necessary. In addition, a large widthwise movement that impairs the sealing performance is prevented so as to prevent the sealing performance from being deteriorated.

[0007]

Means for Solving the Problems To solve the above problems, a means adopted by the present invention is to form a groove on the inner peripheral surface of the valve body.
Formed into a shape, and the projection inserted into the groove is
Formed annularly on the outer peripheral surface, between both sides of the projection and the inner surface of the groove
The springs are arranged separately for each
A large displacement is prevented while permitting the displacement .

[0008]

[Operation] The spring inserted between the seat ring and the valve body can be compressed with a small force for a small displacement, but requires a large force for a large displacement. The slight movement of the seat ring in the width direction due to the contact is easily permitted, and the torque of the valve body is not increased, and the movement of the seat ring in the large width direction which impairs the sealing performance is sufficient. A resistance force is generated, and the movement of the seat ring in the width direction can be prevented.

[0009]

According to the invention, a groove is formed on the inner peripheral surface of the valve body.
Is formed in an annular shape, and the projection inserted into the groove is
Ring formed on the outer peripheral surface of
Since springs are separately arranged between the
Allow for small displacement in the width direction of the ring
While reducing the torque of the valve body, the seat ring
For a large displacement in the width direction, the change is
Position and apply the restoring force required for the seal to the seat ring.
And it is possible to prevent a decrease in sealing performance.

[0010]

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 sealing performance is projected in the circumferential direction. Also, on both sides of the outer peripheral surface, the valve body (14)
A flange portion (12) to be fitted is formed on both sides of the valve body, and a projection (13) to be inserted into a groove (15) on the inner peripheral surface of the valve body is formed at the center of the outer peripheral surface. The protrusion (13) and the groove (15) preferably extend continuously in the circumferential direction.

This invention is based on the projection (1) inserted into the groove (15).
A spring (16) is provided on both sides of (3), and the spring (16) is compressed via a projection (13) from the movement of the seat ring (10) in the width direction. The springs (16) are preferably arranged at appropriate intervals in the circumferential direction as shown in FIG.
However, it goes without saying that they may be arranged continuously in the circumferential direction. Further, the spring (16) is not limited to the coil spring as shown in the figure, but may be another elastic body. Reference numeral (17) denotes a valve body, which is rotatably supported in the valve body at the center of rotation, and comes into contact with and separates from the inner peripheral surface middle and high portion (11) of the seat ring (10).

As shown in FIG. 2, when the valve element (17) comes into contact with the middle / high portion (11) of the seat ring (10), the spring (16) is compressed in the width direction of the compressed seat ring (10). Allow movement. Spring
In (16), the force when it is slightly displaced is small,
Since a large force is required for a large displacement, the valve
(17) The seat ring (1
The small movement in the width direction of (0) is allowed with a small force, and the valve body (1)
The torque applied to 7) becomes smaller. On the other hand, when the seat ring (10) is to be largely moved in the width direction, the force for compressing the spring (16) requires a large force, and the movement of the seat ring (10) in the large width direction is large. In this case, sufficient resistance is generated. As a result, the torque of the valve element is reduced, and a large movement of the seat ring that impairs the sealing performance is prevented, and the sealing performance is maintained.

[Brief description of the drawings]

FIG. 1 is a front view of a seat ring.

FIG. 2 is a sectional view

FIG. 3 is a sectional view showing contact with a valve body.

FIG. 4 is a cross-sectional view of a conventional seat ring.

[Explanation of symbols]

 (10) Seat ring (11) Mid-high section (12) Flange section (13) Protrusion (14) Valve body (15) Groove (16) Spring (17) Valve element

Claims (1)

(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 at the center of rotation in the valve body. In the center type butterfly valve, an annular groove is formed on the inner peripheral surface of the valve body
Then, insert the projection inserted into the groove on the outer peripheral surface of the seat ring.
Formed annularly, between each side of the projection and the inner surface of the groove
Separate springs are provided to allow slight displacement of the seat ring.
A seat ring for a butterfly valve, wherein a large displacement is prevented while accommodating .