JPS5856463Y2 - butterfly valve - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a butterfly valve having a shaft-sealed structure with extremely low external liquid leakage despite its simple structure, and whose fluid contact surfaces are all covered with fluororesin.

A butterfly valve that opens and closes a fluid passage by pressing the valve body against the valve seat or separating it from the valve seat by rotating the rotary shaft that is fixed integrally with the valve body, has a special feature in the shaft sealing mechanism of the rotary shaft. Regarding the butterfly valve, the present applicant previously filed Utility Model Application No. 52-8330 (Japanese Utility Model Application No. 53-103942).

This is a butterfly valve that has a relatively excellent shaft sealing effect when the fluid pressure is relatively low or when used for a short period of time, but when the fluid pressure used is high,
Alternatively, when used for a long period of time, external liquid leakage may occur.

This is because the cone link, which is inserted into the rotating shaft and has a recess in the corner, is in line contact with the rotating shaft or the body, so it is subject to extremely high wear. Even if the recess is inserted, the high pressure tightening caused by wear at the opening end of the recess will actually expand the opening of the O-ring or cone ring and the corrosion-resistant coating layer, so if the fluid pressure used is high as described above, Alternatively, external liquid leakage may occur during long-term use.

The present invention is based on the above-mentioned earlier application, Utility Model Application No. 52-833.
This is an improved idea that solved the drawback of No. In a butterfly valve that opens and closes a passage, a seal ring with a notch at the corner and a roughly triangular cross section is inserted into a pair of upper and lower rotating shafts fixed to the upper and lower central parts of the valve body, and the seal ring is pressed. is performed by the tightening force of the sleeve via the holding ring and the elastic body, and the height of the notch of the seal ring in the direction of the rotation axis is larger than the diameter of the O-ring, and the end thereof is larger than the diameter of the O-ring. It is a butterfly valve characterized by having a shaft sealing structure that is smaller than the smaller structure, and despite its simple structure, it has extremely low external liquid leakage, especially the fluororesin coating that has an excellent shaft sealing mechanism for the rotating shaft. To provide butterfly valves.

A more detailed configuration of the present invention will be explained based on FIGS. 1 and 2 showing one specific example.

The inner surface of the metal body 1 is coated with silicone rubber,
A corrosion-resistant body liner 3 made of fluororesin is applied to an elastic body 2 such as ethylene propylene rubber to form a valve seat.

On the other hand, the surface of the valve body 4 is also coated with a corrosion-resistant coating 5 made of fluororesin.
The corrosion-resistant coating 5 extends onto the surfaces of a pair of vertical rotation shafts 6, 6' which are integrally fixed to the valve body 4.

A seal ring 7.7' made of fluororesin and having a substantially triangular cross section is inserted through the pair of upper and lower rotating shafts 6, 6'.

This sealing ring 7,7' has cutouts 8,8' at the corners, into which O-rings 9,9' are inserted.

Note that the notches 8, 8' of the seal rings 7, 7' are closer to the rotating shafts 6, 8' than the diameters d of the O-rings 9, 9', as shown in FIG.
The height H in the 6' direction is preferably about 1.2 to 2.5 times larger, and the width of the notches 8, 8' is larger than that of the O-rings 9, 9'.
It is preferably formed to be about 0.9 to 0.7 times smaller than the diameter d of.

Then, on the back surface of the seal ring 7.7', a presser ring 12.12', as shown in FIG. With the interposition of an elastic body 13.13' such as a metal disc spring, the seal ring 7.7' is attached to the corrosion-resistant coating 5 on the rotating shafts 6, 6' and the body body by the tightening force of the sleeve 14.14'. The shaft is sealed by making surface contact with the body liner 3 on the inner surface of the shaft.

Note that the concave groove 11 of the inclined surface 10 of the retaining ring 12.12' allows the seal ring 7.7 to fit into the concave groove 11 after tightening.
This is to prevent the rotation of the seal rings 7 and 7' due to the rotation of the rotary shafts 6 and 6' due to biting.

In addition, 15 is a bearing that smoothes the rotation of the rotating shafts 6, 6', and 16 is an asbestos plate or metal plate provided on the back surface of the body liner 3 on the inner surface of the body main body 1 corresponding to the shoulder of the valve body 4. It is a sim consisting of etc.

The butterfly valve of the present invention has the above-mentioned configuration, and in particular, as mentioned above, the seal ring 7.7'
The height H of the notches 8, 8' in the direction of the rotating shafts 6, 6' is 0.
It is larger than the diameter d of the rings 9, 9' and its width is O.
Since it has a specific structure smaller than the diameter d of the rings 9, 9', even if the seal rings 7, 7' are pressed against each other by tightening the sleeves 14, 14', the O-rings 9, 9'
No unreasonable force acts on 9', and even if a large force were applied to O
Even if the O-rings 9, 9' are applied to the O-rings 9, 9', the O-rings 9, 9' will move freely within the notches 8, 8' in the direction of the rotation axis 6° 6' and escape. No excessive force is applied to 9'.

Therefore, the seal of the seal ring 7.7' is prevented from being pushed apart by the O-rings 9, 9' or the seal ring 7.7', or by pushing out the opening of the body liner 3 provided on the inner surface of the body main body 1. It does not inhibit the effect at all.

In addition, since the width of the notch 89g is slightly smaller than the diameter d of the O-rings 9, 9', an appropriate tightening force is applied to the O-rings 9, 9' by the seal rings 7°7', so that the O-rings are By adding an appropriate tightening force in addition to the sealing effect, the tightening force in the direction of the rotating shafts 6, 6' becomes larger, so that the sealing effect is further improved.

Furthermore, seal ring 7.7' and presser ring 12°12
' are in full contact with each other on the inclined surface, so the pressing force acts uniformly on the seal ring 7.7', and therefore the corrosion-resistant coating 5 on the seal ring 7.7' and the rotating shafts 6, 6' Also, surface contact between the inner surface of the valve body 4 and the body liner 3 can be made more reliably.

In addition, the tightening force by the sleeves 14 and 14' is reduced by the elastic body 13.
, 13' to the seal ring 7.7', permanent deformation of the fluororesin such as the corrosion-resistant coating 5 on the surfaces of the seal ring 7.7' body liner 3 and valve body 4 due to compressive strain. Even if there is liquid leakage, it can be absorbed by the elastic force of the elastic body 13° and 13', and a stable pressing force can be applied, so that liquid leakage is extremely unlikely to occur.

Therefore, in the butterfly valve of the present invention, in the shaft sealing structure of the rotary shaft against external liquid leakage due to rotation of the rotary shaft, there is a gap between the body liner 3 on the inner surface of the body body 1 and the corrosion-resistant coating 5 on the surface of the valve body 4. , between the corrosion-resistant coating 5 on the surface of the valve body 4 provided up to the rotating shafts 6, 6 and the O-rings 9, 9', and between the corrosion-resistant coating 5 and the seal rings 7, 7'. Since the seal structure can be ensured, external liquid leakage can be completely prevented.

Moreover, a non-sliding seal is provided between the seal ring 7, 7' and the body liner 3 on the inner surface of the body main body 1, so that liquid leakage can be completely prevented.

As mentioned above, the butterfly valve of the present invention has a simple structure, but has very little external liquid leakage, and can be used stably for a long period of time, especially when the fluid pressure is high. Moreover, since all fluid contact surfaces are covered with fluororesin, it has excellent corrosion resistance, and can be used particularly for chemical industry, making it an extremely useful butterfly valve in industry.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing a cross section of the butterfly valve of the present invention, and FIG. 2 is an enlarged explanatory view of the shaft sealing portion of FIG.
FIG. 3 is an explanatory diagram schematically showing the relationship between the seal ring and the O-ring, and FIG. 4 is an explanatory diagram showing a partial cross section of one specific example of the presser ring. DESCRIPTION OF SYMBOLS 1... Body main body, 2... Elastic body, 3... Bottle liner, 4... Valve body, 5... Corrosion-resistant coating, 6,
6'...Rotating shaft, 1.7'...Seal ring, 8,
8'...notch, 9,9'...O-ring, 10...
- Inclined surface, 11... Concave groove, 12.12'... Presser foot nong, 13.13'... Elastic body! 4.14'...
Sleeve, 15...Bearing, 16...Shim, H
...height of notch, L...width of notch, d...O
IJ diameter.

Claims (1)

[Scope of utility model registration request] In a butterfly valve that opens and closes a fluid passage by separating the valve body from the valve seat or pressing it against the valve seat due to the rotation of a rotating shaft that is fixed integrally with the valve body, there are A seal ring 7.7 having a notch 8, 8' at the corner and having a roughly triangular cross section is inserted into the fixed pair of upper and lower rotating shafts 6, 6'.
12' and the elastic body 13.
13' by the tightening force of the sleeves 14, 14', and the notches 8, 8' of the seal ring 7.7'.
The height H in the direction of the rotating shafts 6, 6' of the O-rings 9, 9'
is larger than the diameter d of the O-rings 9, 9'
A butterfly valve having a shaft sealing structure having a diameter smaller than the diameter d of the butterfly valve.