JP2557797Y2 - Butterfly valve seat structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve seat structure for a butterfly valve which handles a high-temperature fluid or a low-temperature fluid.

[0002]

2. Description of the Related Art FIG . 3 shows a conventional butterfly valve .
There is something like that. In this butterfly valve, an annular metal sheet 3 for sealing between both the valve box 1 and the valve body 2 is provided, and the annular metal sheet 3 is attached to the valve body 2.
The outer peripheral portion 3a is formed into a disc spring shape that is deformed so as to be relatively displaced in the axial direction with respect to the inner peripheral portion 3b with the valve opening operation. Metal sheet 3 against displacement caused by temperature difference between
Are deformed and follow to maintain the sealing property.

[0003]

However, according to the above-described conventional structure, the annular metal sheet 3 is formed so as to be able to bend and deform, so that it has poor rigidity, and the fluid to be handled has a high pressure. In such a case, there is a problem that the sealing property is impaired.

[0004] The present invention solves the above-mentioned problems and provides a butterfly valve which can follow displacement caused by temperature changes of a valve box and a valve body and can maintain a sealing property even under high pressure. It is an object to provide a valve seat structure.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a butterfly valve in which a seal member is provided around a valve port of a valve box to seal between the valve body and the valve body. Forming a curved surface that expands from one side to the other and forming a tapered surface that circumscribes the curved surface of the valve body in the seal material, and supports a thin cylindrical seal portion and the minimum diameter portion of the seal portion. And a pressure adjusting plate having elasticity that urges the minimum diameter portion of the seal portion toward the peripheral portion of the valve body in the valve box. A pressing force adjusting portion for pressing the pressing member toward the peripheral edge portion of the valve body is screwed to the valve box side so as to be provided so as to be able to move back and forth.

[0006]

According to the above construction, when the valve element is in the open state, the outer peripheral edge of the support portion is supported by the valve box, and the seal portion is in a free end state. Deformable. Further, in the closed state of the valve body, the thin seal portion of the sealing material comes into close contact with the peripheral edge of the valve body by its own elastic force, and stops water around the valve body at the valve port.

[0007] When watertightness is impaired due to a failure in the close contact between the sealing portion of the sealing material and the peripheral portion of the valve element,
The pressing force adjusting part is pushed toward the valve body by screwing with the valve box side, the minimum diameter part of the seal part is pressed via the pressing force adjusting plate, and the supporting part is bent to seal the peripheral part of the valve body. Strengthen the pressing force of the part. Therefore, even when the valve box and the valve body have a shape error due to a dimensional error and a temperature change at the time of manufacture, the support portion and the seal portion of the thin seal material can absorb the above-mentioned change by bending. it can.
In addition, the strength of the supporting portion supporting the seal portion can be appropriately reinforced by the pressing force adjusting plate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a valve body 13 that opens and closes a valve port 12 is provided inside a valve box 11 so as to be rotatable around the axis of a valve stem (not shown). The valve body 13 is formed in an arc shape along the rotation direction, and has a curved surface whose diameter increases from one side surface to the other side surface of the valve body 13.

Further, an annular sealing member 15 for sealing between the valve body 13 and the valve port 13 of the valve box 11 sandwiches an outer peripheral edge between the valve box 11 and the annular sealing member pressing portion 16. The seal holding portion 16 is fixed to the valve box 11 by bolts 17. Also, sealing material 15 and valve box 11
A ring seal 18 is interposed therebetween.

The seal member 15 has an annular support portion 15a extending in the radial direction of the valve port 12, and a cylindrical seal portion 15b formed at the tip of the support portion 15a.
12 is formed so as to be deformable in the flow direction and the radial direction. Further, the sealing portion 15b of the sealing material 15 is formed in a tapered surface circumscribing the curved surface of the valve body 13, and the supporting portion 15a
Supports the minimum diameter portion of the seal portion 15b.

A disc spring-like pressing force adjusting plate 19 for urging the minimum diameter portion of the seal portion 15b toward the peripheral portion 14 of the valve body 13 is disposed inside the valve box 11. A pressing force adjusting unit 20 is provided behind the pressure adjusting plate 19 so as to be screwed into the sealing material pressing unit 16 and to be able to move back and forth. The pressing force adjusting portion 20 presses the pressing force adjusting plate 19 toward the peripheral portion 14 of the valve body 13.

The operation of the above configuration will be described below.
In the open state of the valve body 13, the seal member 15 has the outer peripheral edge of the support portion 15 a supported by the valve box 11, the inner peripheral edge of the support portion 15 a and the seal portion 15 b at a free end, and It is deformable in the radial direction and the flow path direction. And
When the valve body 13 is rotated around the axis of the valve rod 14 to perform the closing operation, the valve body 13 is
b, the water around the valve body 13 in the valve port 12 is stopped.

The sealing portion 15b of the sealing material 15 and the valve body
When the close contact state of the peripheral portion 14 of 13 is defective and the water stoppage is impaired, the pressing force adjusting portion 20 is pushed toward the valve body 13 by screwing with the sealing material pressing portion 16, and is pushed through the pressing force adjusting plate 19. The minimum diameter portion of the seal portion is pressed, and the support portion 15a is flexed to reinforce the pressing force of the seal portion 15b against the peripheral portion 14 of the valve body 13. Therefore, the pressing force of the seal portion 15 b against the peripheral portion 14 can be arbitrarily adjusted by the amount of movement of the pressing force adjusting portion 20. Further, even if the valve box 11 and the valve body 13 are changed in shape and size due to a dimensional error at the time of manufacture and a temperature change, the support portion 15a and the seal portion 15b of the sealing material 15 are formed.
The above-mentioned fluctuations can be absorbed by bending.
Further, the strength of the support portion 15a supporting the seal portion 15b can be appropriately reinforced by the elastic force of the pressing force adjusting plate 19, and the elastic force of the pressing force adjusting plate 19 can be adjusted by its plate thickness.

FIG. 2 shows another embodiment of the present invention.
Members that perform the same operations as in the previous embodiment are given the same reference numerals and description thereof is omitted. The pressing force adjusting plate 31 has an annular shape and is formed integrally with the pressing force adjusting unit 32, and a predetermined gap is formed between the pressing force adjusting plate 31 and the pressing force adjusting unit 32.

According to this configuration, by moving the pressing force adjusting portion 32, the support portion 15a for supporting the seal portion 15b is provided.
Can be appropriately reinforced by the elastic force of the pressing force adjusting plate 31, and the elastic force of the pressing force adjusting plate 31 can be adjusted by its thickness. Other functions and effects are the same as those of the previous embodiment.

[0016]

As described above, according to the present invention, the sealing material comes into close contact with the valve body while being reinforced by the elastic force of the pressing force adjusting plate. The sealability can be maintained even with the fluid, the rigidity of the support of the sealant is adjusted appropriately, and the shape error due to dimensional errors and temperature changes in the production of the valve box and valve body is reduced. Can be absorbed by bending. Further, the pressing force of the seal portion against the peripheral portion of the valve box can be arbitrarily adjusted by the amount of movement of the pressing force adjusting portion.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of the butterfly valve according to an embodiment of the present invention;

FIG. 3 is an overall vertical sectional view of a conventional butterfly valve.

[Explanation of symbols]

 11 Valve box 13 Valve element 14 Peripheral edge 15 Seal material 19, 31 Pressing force adjusting plate 20, 32 Pressing force adjusting section

Claims (1)

(57) [Scope of request for utility model registration] 1. A butterfly valve in which a sealing material for sealing a space between a valve body and a valve body is arranged around a valve port of a valve box. The seal member is provided with a thin cylindrical seal portion having a tapered surface circumscribing the curved surface of the valve body and an annular thin support portion for supporting a minimum diameter portion of the seal portion, and provided in the valve box. A pressing force adjusting portion that has an elastic pressing force adjusting plate that urges the minimum diameter portion of the seal portion toward the peripheral portion of the valve body and presses the pressing force adjusting plate toward the peripheral portion of the valve body Characterized in that the valve seat is screwed into the valve box side and is provided so as to be able to move back and forth.