JPH1026235A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate processing and assembly, try to reduce cost down and make accuracy high, and exhibit excellent water stopping performance for the application of high pressure by making use of fluid pressure. SOLUTION: When a valve body 5 is in its entirely closed position, a ring shaped seal member 12 roughly in a numerical number 7 shape in cross section provided with an outer circumferential surface part 12c which is deformed outward in the radial direction while being subjected to the pressure of fluid flowing in a flow passage 1A, and is pressed against the oblique seat surface 7a of a seat surface part 7A at the side of a valve box so as to be closely adhered thereto, is mounted to the outer circumference side of the circular valve body 5 corresponding to the seat surface part 7A at the valve box side, which is formed in the inner circumferential surface of the flow passage 1A in the valve box 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve. More specifically, the present invention relates to a butterfly valve having a cylindrical valve body. The present invention relates to a butterfly valve configured to close the flow path by closely contacting the valve box side seat surface at the fully closed position of the valve body.

[0002]

2. Description of the Related Art FIGS. 5 and 6 are a vertical sectional side view and a semi-cross sectional plan view of a general butterfly valve of this type. In each of these figures, an axial direction of a cylindrical flow path 1A in a valve box 1 is shown. The valve stems 2A and 2B, which are divided into upper and lower portions, respectively, are located at substantially vertical central positions opposed to each other in the radial direction, and are perpendicular to the axis b of the flow path 1A and pass through the center of the flow path 1A. A coupling 4 is rotatably supported around a, and a coupling 4 which can be coupled to a rotation operating mechanism (not shown) via a key 3 is connected to an upper end of the upper valve stem 2A.

[0003] A circular valve element 5 disposed in the flow path 1A.
Are fixedly connected to the valve stems 2A and 2B via connecting pins 6 and 6, respectively.
The valve element 5 rotates in the flow path 1A with the rotation of A and 2B to open and close the flow path 1A. A valve body-side seat surface portion 5A is formed on the outer peripheral side of the valve body 5 and the valve box 1 corresponding to the valve body-side seat surface portion 5A.
On the inner peripheral surface of the flow path 1A, a valve box side seat surface portion 7A described later is formed.

FIG. 7 shows a specific configuration of the valve box side seat surface portion 7A which has been conventionally employed in the butterfly valve having the above configuration, and has a substantially T-shaped cross section formed on the valve box 1. As shown in FIG. Ring-shaped elastic sheet 9 having a substantially Ω-shaped cross section in annular concave groove 8
The two side legs 9a, 9a of the ring-shaped elastic sheet 9 are elastically engaged, and the inner surface 9b of the ring-shaped elastic sheet 9 is inclined with respect to the axial direction to slightly protrude into the flow path 1A. A part of the box-side sheet surface 7a is configured. A pressure fluid C can be supplied from the outside into a space S formed by the ring-shaped elastic sheet 9 and the annular groove 8. When the valve element 5 is rotated to the fully closed position, the pressure fluid C is supplied into the space S so that the seat surface 5a of the valve element-side seat surface portion 5A is changed to the seat surface of the valve box-side seat surface portion 7A. The channel 1A is closed so that the fluid leaks well by elastically pressing and closely contacting the channel 7a.

[0005]

In the conventional butterfly valve having the above-described structure, the above-described annular groove 8 having a substantially T-shaped cross section is formed as the structure of the valve box side seat surface portion 7A, and It is necessary to engage and hold a ring-shaped elastic sheet 9 having a substantially Ω-shaped cross section in the annular groove 8.
They are made on the inside of the valve box 1 which is originally narrow,
Because of the assembling, processing and assembling are very complicated and difficult, and increase in manufacturing cost and decrease in manufacturing accuracy are inevitable. In addition, when the fluid pressure is high, the fluid pressure deforms the inner surface 9b of the ring-shaped elastic sheet 9 protruding into the flow path 1A, thereby deforming the seat surface 5A of the valve body side seat surface portion 5A.
a and the seat surface 7a of the valve box side seat surface portion 7A are reduced, and as a result, there is a problem that the water stopping performance is deteriorated.

The present invention has been made in view of the above circumstances, and simplifies the configuration by eliminating the need for processing inside the valve box.
It is an object of the present invention to provide a butterfly valve capable of remarkably improving the water stoppage against a high-pressure fluid while reducing the cost.

[0007]

In order to achieve the above object, a butterfly valve according to the present invention comprises: a valve box having a cylindrical flow path; And, a valve stem held in the valve box in a rotatable state around an axis passing through the center of the streamline, and the inside of the flow passage is rotated by rotation of the valve stem to form the flow passage. A valve body having a circular valve body that opens and closes, a seat surface inclined with respect to the axis of the flow path of the valve box, and a valve box side seat surface formed on an inner peripheral surface of the flow path of the valve box; A butterfly valve having a seat surface inclined relative to the seat surface and having a valve body-side seat surface formed on the outer peripheral side of the valve body; At the fully closed position of the valve body, receiving the fluid pressure and deforming radially outward, thereby causing the inclined seat surface of the valve surface on the valve box side to be inclined. A ring-shaped seal member having a substantially 7-shaped cross section to be pressed is mounted, and the seal member is deformed to exhibit a function of preventing fluid leakage when the valve body is in a fully closed position. At the stage before assembly into the valve box, it is mounted on the valve body side seat surface that is entirely exposed so that a wide working space can be secured freely. Since it is only necessary to form a simple seat surface inclined with respect to the axis,
Processing and assembling inside the valve box in a narrow space becomes unnecessary, and therefore, processing and assembling are very easy, and it is possible to reduce manufacturing cost and improve manufacturing accuracy. In addition, the ring-shaped seal member mounted on the valve body-side seat surface portion has a larger amount of radially outward deformation as the fluid pressure increases, and the pressing force of the valve box-side seat surface portion against the inclined seat surface, Since the adhesion is strengthened, it is possible to exhibit extremely excellent water stopping performance even for a high-pressure fluid.

Further, in the butterfly valve having the above structure,
As described in claim 2, annular recesses are respectively formed on the outer peripheral side of the valve body toward the outside in the radial direction and toward the downstream side of the flow path, and the ring-shaped seal member is formed in the annular recesses. And a member for backing up the seal member by contacting the downstream side surface of the ring-shaped seal member is fixed to the valve body. The deformation to the side is prevented by the backup member, and the amount of deformation of the ring-shaped seal member outward in the radial direction can be increased by that amount, so that the water stopping performance can be further improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged cross-sectional plan view of a main part of a butterfly valve according to the present invention. Since the basic overall configuration of the butterfly valve is as shown in FIGS. 5 and 6, description of the overall configuration is omitted. I do. In FIG. 1, the same reference numerals are given to the same or corresponding components as those shown in FIGS. 5 to 7, and detailed description thereof will be omitted.

In FIG. 1, a valve body-side seat surface 5A formed on the outer peripheral side of the valve body 5 is provided with
Annular recesses 11 each open toward the downstream side of A
Are formed. Reference numeral 12 denotes a ring-shaped seal member having a substantially 7-shaped cross section that is opened radially inward, and is fitted into the annular recess 11 so that its front hanging portion 12a is located on the upstream side of the flow path 1A. In addition, the annular base portion 12b of the ring-shaped seal member 12 is in contact with the backup auxiliary valve body 14 fixed to the downstream side surface of the valve body 5 via the annular gasket 13, so that there is no downstream deformation. Have been backed up. When the ring-shaped seal member 12 thus attached is subjected to fluid pressure at the fully closed position of the valve body 5, its outer peripheral surface portion 12c is deformed radially outward and the inclination of the valve box side seat surface portion 7A. It is made of a material that is pressed against and adheres to the sheet surface 7a. In order to make the outer peripheral surface 12c easily deformable, as shown in FIG. A notch 15 is formed along the radial direction. Note that a simple annular backup member may be used in place of the backup auxiliary valve element 14.

In the butterfly valve configured as described above, the valve element 5 is moved to the fully closed position via the valve rods 2A and 2B such that the outer peripheral seat surface 5A faces the valve box side seat surface 7A. When rotated to close the flow path 1A, as shown in FIG.
1, a fluid pressure P acts on the inner surface 1 and the outer peripheral surface portion 12c of the ring-shaped seal member 12 is deformed radially outward in response to the fluid pressure P, so that the inclined seat surface 7a of the valve box side seat surface portion 7A.
Is pressed into close contact. Here, as the fluid pressure P is higher, the outer peripheral surface portion 12c of the ring-shaped seal member 12 is greatly deformed radially outward, and is strongly pressed and adhered to the inclined sheet surface 7a. Reliable water stopping performance is exhibited.

In the butterfly valve having the above-described structure, the ring-shaped sealing member 12, which exhibits the above-described high water stopping performance, is mounted on the valve body-side seat surface 5A, and is provided on the valve box-side seat surface 7A. Is a simple inclined sheet surface 7a
Is formed, and it is not necessary to process or assemble the inside of the valve box 1 in a narrow space. Therefore, machining and assembling of the butterfly valve as a whole is very easy. It is possible to improve the manufacturing accuracy.

FIG. 4 is an enlarged cross-sectional plan view of a main part showing another embodiment of the butterfly valve according to the present invention. In this example, the ring-shaped sealing member 12 is provided on the outer peripheral side of the upstream side surface of the valve body 5. Is directly fixed and held, and does not require the use of a backup member such as the backup auxiliary valve element 14 used in the above-described embodiment, thereby simplifying the structure. In addition, the outer peripheral surface 12c of the ring-shaped seal member 12 is effectively
Can be radially outwardly deformed so as to secure good water stopping performance such as pressing against the inclined seat surface 7a of the valve box-side seat surface portion 7A and closely contacting it.

[0014]

As described above, according to the present invention, the sealing member for exhibiting the function of preventing fluid leakage when the valve element is in the fully closed position is completely covered before the assembly into the valve box. Is mounted on the valve body side seat surface that can freely secure a wide work space in the exposed state, and the valve box side seat surface has a simple seat surface inclined with respect to the axis of the flow path. Therefore, it is not necessary to process or assemble the inside of the valve box in a narrow space, so that the entire valve can be easily processed and assembled, and the production cost can be reduced and the production accuracy can be improved. In addition, the ring-shaped seal member mounted on the valve body-side seat surface portion is deformed more radially outward as the fluid pressure becomes higher, so that the ring-shaped seal member is strongly pressed against the inclined seat surface of the valve box-side seat surface portion to make close contact. Therefore, there is an effect that very excellent water stopping performance can be exhibited even for a high-pressure fluid.

In particular, by adopting the configuration as described in claim 2, deformation of the ring-shaped seal member to the downstream side when receiving fluid pressure is prevented by the backup member, and the ring-shaped seal member is accordingly reduced. The amount of deformation of the seal member in the radially outward direction can be increased, and the water stopping performance can be further improved.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional plan view of a main part of a butterfly valve according to the present invention.

FIG. 2 is a front view of a ring-shaped sealing member in the butterfly valve.

FIG. 3 is an enlarged cross-sectional plan view of a main part illustrating an operation state of the butterfly valve.

FIG. 4 is an enlarged cross-sectional plan view of a main part showing another embodiment of the butterfly valve according to the present invention.

FIG. 5 is a vertical sectional side view showing an entire configuration of a general butterfly valve.

FIG. 6 is a half-cross-sectional plan view showing the entire configuration of the butterfly valve.

FIG. 7 is an enlarged cross-sectional plan view of a main part of a conventional butterfly valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 1A Flow path 2A, 2B Valve stem 5 Valve body 5A Valve body side seat surface part 7A Valve box side seat surface part 7a Valve box side inclined seat surface 11 Annular recess 12 Ring-shaped seal member P Fluid pressure a Rotating shaft b flow Road axis

Claims (2)

[Claims] 1. A valve box having a cylindrical flow path, wherein the valve box is rotatable about an axis perpendicular to the axis of the flow path of the valve box and passing through the center of the stream line. A valve stem held by the valve box, a circular valve element that rotates in the flow path with the rotation of the valve stem to open and close the flow path, and a shaft center of the flow path of the valve box. Having a sloping seat surface, a valve box side seat surface portion formed on the inner peripheral surface of the flow path of the valve box, and a seat surface sloping corresponding to the sloping seat surface;
A butterfly valve having a valve body-side seat surface formed on the outer peripheral side of the valve body, wherein the valve is opened radially inward on the outer peripheral side of the valve body, and the fluid pressure is set at a fully closed position of the valve body. A butterfly valve, which is provided with a ring-shaped sealing member having a substantially 7-shaped cross section which is deformed radially outward in response to the pressure and pressed against the inclined seat surface of the valve box side seat surface. 2. An annular recess which is opened radially outward and downstream of the flow path is formed on the outer peripheral side of the valve body, and the ring-shaped seal member is fitted into the annular recess. 2. The butterfly valve according to claim 1, wherein a member that abuts on a downstream side surface of the ring-shaped seal member and backs up the seal member is fixed to the valve body.