JPH0337064B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a sealing device for a butterfly valve that can reliably seal between the outer circumference of the valve body and the inner circumference of the valve body when the valve body is closed. Regarding.

[Conventional technology]

Conventional butterfly valves of this type have a structure in which the outer periphery of the valve body, which is simply a single plate-like member, is simply pressed against the sheet metal on the inner periphery of the valve body, making it watertight. .

[Problem that the invention seeks to solve]

However, with such a structure, if strong water pressure is applied to the butterfly valve, or if the water pressure or water flow changes, or if it is used for many years, the seal structure with only fixed pressure welding may not have sufficient sealing performance. However, there were problems in that leakage often occurred and repair and adjustment required a lot of cost, effort, and time.

[Means for solving problems]

The present invention solves such problems and makes it possible to maintain highly accurate sealing performance.Therefore, the inner peripheral surface of the valve body, which is the outer peripheral side of the valve body, is A sheet metal is formed that is inclined in the axial direction of the valve body, and a seal ring whose outer peripheral surface is curved so that it can come into contact with the inner peripheral surface of the sheet metal can be slid freely in the radial groove formed on the outer periphery of the valve body. At the same time, the inner peripheral surface of the seal ring is integrally formed with a bent portion in the shape of a disc spring that can be fitted into the peripheral groove with both sides approaching the inner surface of the peripheral groove. be.

[Effect]

Therefore, since the disc spring-like bent part has a strong internal stress that tends to spread outward, the seal ring strongly presses against the sheet metal due to its elastic force, and the ring has self-aligning properties. In this state, the bent portion comes into contact with the inner surface of the circumferential groove to prevent the seal ring from falling down, and a highly accurate watertight seal can be achieved.

〔Example〕

Next, the embodiment shown in the drawings will be described.

Fig. 2 shows a front view of the entire butterfly valve, and a valve body A, which is a main valve with a built-in subvalve a in the center, is fitted inside a cylindrical valve box B. The auxiliary valves a are each rotatable by vertical valve shafts, and are installed so that they can be opened and closed by the main valve operating shaft 6 and the auxiliary valve operating shaft 7 above the upper operating case 5. It is configured similarly.

On the inner periphery of the valve body B, which is the outer periphery side of the valve body A,
With a constant width, the inner circumferential surface 1a is θ in the axial direction of the valve body B.
A sheet metal 1 that is inclined by an angle is integrally formed, and a holding plate 8 is provided around the end face side of the valve body A.
is fixed with bolts 9, and a circumferential groove 2 having a uniform width and radial direction is formed inside the circumferential groove 2, and an outer circumferential surface 3a within the circumferential groove 2 is curved and slightly narrower than the circumferential groove 2. The seal ring 3 is fitted, and on the inner circumference side of the seal ring 3, there is an outer circumference of a bent portion 3b that forms a disc spring shape with both sides approaching the inner surface of the circumferential groove 2 and maintaining a gap C. Formed integrally by connecting the sides,
A bottom portion 3c that can be closely fitted to the bottom of the circumferential groove 2 is integrally formed in series on the inner peripheral side of the bent portion 3b.

Note that the outer peripheral side of the sub-valve a can also be constructed in the same manner as the structure described above.

Therefore, the seal ring 3 and the bent portion 3b
can slide within the circumferential groove 2, and the bent portion 3b
This means that the seal ring 3 can be pressed outward with a strong internal stress as it expands outward, and when the valve body A is rotated to the closed state,
When the outer circumferential surface 3a of the seal ring 3 starts to come into contact with the inner circumferential surface 1a of the sheet metal 1, the seal ring 3 automatically aligns its center with the sheet metal 1.
This results in self-aligning contact, and in this state, both sides of the bent portion 3b come into contact with the inner surface of the circumferential groove 2, thereby preventing the seal ring 3 from falling.

〔Effect of the invention〕

In this way, the present invention allows the seal ring to be brought into pressure contact with the inclined inner circumferential surface of the sheet metal by the elastic pressure of the bent portion having strong internal stress. The self-aligning properties allow for close contact, ensuring highly accurate watertightness, further improving the watertight effect, and allowing for a simple structure that allows the seal ring to operate well, making it suitable for implementation. It has characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of an embodiment of the present invention.
FIG. 2 is a front view of the entire butterfly valve, and FIG. 3 is an exploded explanatory view of FIG. 1. A... Valve body, B... Valve box, 1a... Inner circumferential surface, 1... Sheet metal, 2... Circumferential groove, 3a... Outer circumferential surface, 3... Seal ring, 3b... Bent part.

Claims (1)

[Claims] 1. In an eccentric or concentric opening/closing butterfly valve, a sheet metal whose inner peripheral surface is inclined in the axial direction of the valve body is formed on the inner periphery of the valve body, which is the outer peripheral side of the valve body, and a sheet metal is formed on the outer periphery of the valve body. A seal ring whose outer circumferential surface has a curved surface that can come into contact with the inner circumferential surface of the sheet metal is slidably fitted into the circumferential groove in the radial direction. 1. A sealing device for a butterfly valve, characterized in that a bent portion in the shape of a disc spring is integrally formed with both sides of the inner surface close to each other and can be fitted into a circumferential groove.