JPH0326355Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a main/sub valve sealing device for a butterfly valve that can provide a high degree of sealing when the main valve and sub valve are closed.

[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, is pressed against a sheet metal on the outer periphery side for sealing.

[Problem that the invention attempts to solve]

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 is only fixed pressure welding, and the sealing performance may be insufficient. This has led to problems in that it often leaks, and that repairing and adjusting it requires a large amount of cost, effort, and time.

[Means for solving problems]

The present invention solves this problem and makes it possible to achieve a high degree of sealing between the main valve and the auxiliary valve. A seat with an inclined surface is formed on the inner circumferential surface of the main valve, and a watertight ring with a curved outer circumferential surface is fitted into the circumferential groove on the outer circumference of the main valve and the circumferential groove on the outer circumference of the auxiliary valve. Elastic rings each containing a spring are fitted into both circumferential grooves on the bottom side of the ring.

[Effect]

Therefore, when the main valve and the sub-valve are rotated and closed, each watertight ring is well pressed in the outer circumferential direction by the elastic ring and is pressed against the outer circumferential seat with self-aligning property. This means that highly accurate seals can be made.

〔Example〕

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

FIG. 3 shows a front view of the entire butterfly valve. Inside the valve box 3, a main valve 1 that can be rotated around a central main valve shaft is mounted. A sub-valve 2 that can be rotated around a sub-valve shaft 10 is mounted inside the water passage hole 9 formed in the main valve operating shaft 12 and a sub-valve operating shaft 12 that protrude above the upper operation case 11. The valve operating shaft 18 allows the main valve 1 and the sub valve 2 to be opened and closed, respectively, and is constructed in the same manner as the conventional structure.

The inner periphery of the valve box B, which is the outer periphery of the main valve 1, and the inner periphery of the water passage hole 9 have slopes 14a, 14.
Seats 4a and 4b are respectively formed, and around the end surfaces of the main valve 1 and the sub valve 2, presser plates 15a and 15b are fixed with bolts 16a and 16b, and circumferential grooves 5a and 5b are formed inwardly. Watertight rings 6a and 6b whose outer peripheral surfaces are curved are slidably fitted into both circumferential grooves 5a and 5b, respectively, and the inner circumferential bottom surfaces of both rings 6a and 6b are connected to the circumferential groove 5.
There are springs 7a and 7 between the bottom surfaces of a and 5b.
B is internally installed and has a slit on the side part, and the cross section is approximately C.
It is constructed by fitting elastic rings 8a and 8b into each other.

Therefore, when the main valve 1 and the auxiliary valve 2 are closed while water pressure is applied to them as shown by arrows a and b, the elastic rings 8a and 8b backed up by the springs 7a and 7b close together. 6
The rings 6a and 6b are pressed in the outer circumferential direction, and the rings 6a and 6b have self-aligning properties and are in close contact with the sheets 4a and 4b.
This means that highly accurate watertightness can be achieved.

[Effect of idea]

In this way, the present invention allows the watertight rings 6a, 6b fitted around the outer peripheries of the main valve 1 and the auxiliary valve 2 to be pressed toward the seats 4a, 4b by the elastic rings 8a, 8b inside the springs 7a, 7b. As a result, when the valve is closed, the rings 6a and 6b have self-aligning properties and come into close contact with the seats 4a and 4b, and there are elastic rings 8 in the circumferential grooves 5a and 5b.
A and 8b are in pressure contact with each other to ensure watertightness with high accuracy regardless of the water pressure, and it has a feature that it can be suitably implemented with a simple structure of the so-called metal touch type.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main part of an embodiment of the present invention.
Figure 2 is a sectional view of other important parts, Figure 3 is a front view of the entire butterfly valve, Figure 4 is an exploded view of Figure 1, and Figure 5
The figure shows an exploded view of FIG. 1...Main valve, 2...Sub-valve, 3...Valve box, 4a,
4b... Sheet, 5a, 5b... Circumferential groove, 6a, 6
b...Ring, 7a, 7b...Spring, 8
a, 8b...Elastic ring.

Claims (1)

[Scope of utility model registration request] In a butterfly valve configured by incorporating a width valve 2 in the center of the main valve 1, the inner circumferential surface of the valve box 3, which is the outer circumferential side of the main valve 1, and the inner circumferential surface of the main valve 1, which is the outer circumferential side of the auxiliary valve 2. Seats 4a and 4b each having an inclined surface are formed on the circumferential surface, and watertight rings 6a and 6b having curved outer circumferential surfaces are fitted into the circumferential groove 5a on the outer circumference of the main plate 1 and the circumferential groove 5b on the outer circumference of the sub-valve 2, respectively. In both circumferential grooves 5a, 5b, which are on the bottom side of both rings 6a, 6b, are elastic rings 8 with springs 7a, 7b installed inside.
A main/sub valve sealing device, characterized in that the elastic rings (a) and (8b) are fitted into each other, and the slit-like cut in the elastic ring is configured to open in the direction in which water pressure is applied.