JPS58149474A - Sealing mechanism for eccentric-type butterfly valve - Google Patents

Abstract

PURPOSE:To enable to obtain a uniform and sufficient sealing effect irrespective of the flowing direction of a fluid, by a method wherein an inner sealing part of a seal ring is located at a position between an outside peripheral sealing surface of a valve plate and a tapered surface of a main body of the valve. CONSTITUTION:The seal ring 5 is composed of an outer sealing part 51 and the inner sealing part 52, and the outer sealing part 51 is rigidly clamped between a side face of the main body 1 of the valve and an annular retainer 4, while the inner sealing part 52 is located at a position between the outside peripheral sealing surface 31 of the valve plate 3 and the tapered surface 11 of the main body 1. Accordingly, whether the fluid flows in the direction of an arrow A or in the direction of an arrow B, the inner sealing part 52 of the seal ring 5 is pressed against the sealing surface 31 of the valve plate 3 by the pressure of the fluid itself, and a uniform and sufficient sealing effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing mechanism for an eccentric butterfly valve.

As part of the eccentric butterfly valve is shown in FIG. 1, the eccentric butterfly valve is composed of an annular valve body 1 and a valve 112 with a valve plate 3 fixed thereon, which is rotatably mounted on the annular valve body 1. The valve plate is disposed at a position shifted from the valve plate, and the outer circumferential sealing surface 61 of the valve plate is a truncated circular plumbum surface or a similar one that converges at a point on the downstream side in the fluid flow direction on the central axis of the valve. It is usually formed on a toric surface.

With this configuration, there is nothing on the outer peripheral sealing surface of the valve plate that obstructs the sealing action, making it easy to achieve uniform sealing over the entire circumference. Since the outer peripheral sealing surface of the valve plate is formed on a converging circular m-plane, etc., when fluid flows in the direction of the arrow in Figure 1, the fluid pressure in the pipe causes the valve plate to be in the closed position as shown in the figure. The valve plate 6 tends to be pushed downstream, and the valve plate outer cylinder sealing surface '31 is firmly pressed against it by the ring made of rubber or other elastic material, which is advantageous because the sealing action is strengthened. be.

However, if the fluid is flowing from the direction of arrow B in FIG. They tend to separate, resulting in insufficient sole action and a tendency to leak. If the sole ring is made of rubber-like elasticity or a large, flexible material, it is relatively easy to overcome this drawback, and many jokes have already been made regarding this point. .

However, it is difficult or undesirable to use a sealing material such as rubber due to the nature of the fluid to be controlled, and when using a seal link made of metal, metal is much more elastic or smaller than rubber, and the seal Since the amount of compression caused by the compression of the valve plate at the time was small, it lacked ability to follow changes in fluid pressure and displacement of the valve plate, and sufficient sealing performance could not be obtained. Attempting to increase the compressibility to obtain sealing performance in both directions increases the rotational torque of the valve, which adversely affects the performance and life of the valve drive device.

This invention aims to eliminate the above-mentioned drawbacks when using a gold MW seal ring in an eccentric butterfly valve. An annular elastic member is integrally provided, and even when fluid is applied from any direction, the seal ring is pressed against the outer sealing surface of the valve plate by the fluid pressure itself, and the seal ring itself is more firmly attached to the valve plate. The purpose of the present invention is to provide a seal rod structure which not only produces a sufficient sealing effect by being pressed against the valve, but also can reduce as much as possible the rotational torque during valve operation.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a 11-sided view showing the essential parts of an eccentric butterfly valve equipped with a sealing mechanism according to the present invention, in which a valve shaft 2 to which a valve plate 3 is fixed is attached to a block-shaped valve body 1. It is attached so that it can be rotated freely. A sole ring 5 is provided on one side of the valve body 1.
An annular retainer 4 is provided to support the valve body 1, and this retainer 4 is fixed to the valve body 1 by bolts or other suitable means, and between the valve body -0Ili surface and this retainer 4, there is a The sole link 5 having such a structure is fixed, and its radially inner side 111 and end sealing portion press against the sealing surface 61 of the valve plate 3 formed in the shape of a truncated chime as described above to provide a sealing effect. shall be played.

In the illustrated embodiment, five seal rings have the configuration shown in FIGS. 1 and 2.

As you can see from Konera's TzI, there are 5 sole rings, j
One bullet f4. It is made of ring-shaped gold pine wood with a radial cross section 1, whose radial cross section is approximately circular) ÷ circular group 8] 1!・Seal part 51 is within 1 (
An inner rail portion 52 formed in the r↓[b1 phase is formed on each side of the ill, and one or several (in the illustrated embodiment, one rail portion) is formed between the two seal portions as necessary. ) A connecting portion 56 having an uneven cushion portion 54 is formed, and these seal portions and cushion portions are all arranged concentrically. In the illustrated embodiment, an annular coil spring 55,56 is tightly fitted inside each seal 51,52 over its entire circumference in order to adjust the elasticity of each seal.

The seal ring 5 described above shall be mounted on the valve as shown in Figure 1. That is, the outer seal portion 51 of the seal link 5 is firmly sandwiched between one side of the valve body 1 and the annular retainer 4 fixed thereto, and the inner seal portion 52 holds the valve plate 6 when the valve is closed. It comes into contact with the outer peripheral sealing surface 31. In the illustrated embodiment, since the cushion portion 54 protrudes outward, the retainer is provided with a concave portion PjT41 in order to receive this portion.
is profitable. It is natural that the recess 41 will be irregular in a mating case in which the cushion portion protrudes only in the direction opposite to that shown in the figure.

The retainer 4 is inserted radially inwardly into the inner part of the seal ring.
'l/-ru part 52J reaches 6'1'! , and the inner side 11H42 or the 7-le link connecting portion 56 comes into contact with a part of the inner 1-knoll portion 52 from one of the bevel surfaces, and in the vicinity of the 7-le link portion 52. Go and insert a small piece between the connecting part 53 and the inner surface of the retainer 42.
1, there is a gap, and the seal portion 52 has the horizontal force 1#11 shown in the figure.
It has become a meeting.

Further, at the inner end of the one surface of the valve body 1, there is a 1-slot.
Small fruit M! In example i, a truncated circular pattern 11 (hereinafter referred to as a tapered surface) is formed so as to converge at a point on the central axis of the valve, on the left side of the well shown in the drawing, etc. (The 11u seal portion 52 comes into contact with this tapered surface.

Sole # by Kitoko using sole links like previous 8 [1]! Since it is structured as explained above,
8! In Fig. 1, when the fluid flows in the direction of the arrow, when the cypress is held in its closed position as shown in Fig. x
t+ 52 is decorated in the inner space f"h, and the inner seal part 52 comes into pressure contact with the outer circumferential surface of the valve plate to shut off the fluid. At this time, the seal link 5 connects the valve body 1 and the retainer 4. Since the outer seal portion 51 is firmly clamped by the retainer, leakage of fluid from between the valve body and the retainer into the valve array is prevented.

Furthermore, the inner seal portion 52 is connected to the outer seal portion 51 which is clamped and fixed to the plate-shaped connecting portion 5 including the cushion portion 54.
5, the valve plate outer sealing surface 31 in the shape of a round button (may be a part of a spherical surface) is connected to the inner sealing portion 5.
2, even if there is a slight eccentricity between the two, the position of the outer seal part relative to the valve plate is automatically corrected, and the outer seal part is pressed against the outer peripheral sealing surface of the valve plate uniformly. It provides an even sealing effect. When the valve is closed, upstream 9111 (left side in the diagram)
When this fluid pressure is applied to the seal portion 52, the seal portion 52 is restrained by the retainer inner surface 42 and its movement toward the downstream side is restricted. On the other hand, the valve root 6 receives pressure in the direction of arrow A, the valve shaft 2 bends, and the valve plate tends to be displaced in the downstream direction. Therefore, the seal portion 52 is connected to the inner surface 42 of the retainer and the outer peripheral surface 61 of the valve plate.
Seal f'+, III is performed while being sandwiched between. This sealing action is basically the same as that of known eccentric butterfly valves.

When the At body is in the opposite direction to the above, that is, in the direction of the arrow B in Figure A1, we pray about this according to Figure 6. 1 lees 1 shows the relationship between the inner 1 seal portion 52 in FIG. For simplicity, the annular coil spring 56 installed in the inner seal portion is omitted.

If fluid pressure exists in the direction of arrow B when Ime-1 is completed, jT
&3 moves i! from the seal portion 52 to the left in the figure due to fluid pressure.
On the other hand, due to this pressure, the connecting portion 53 of the 7-ring 5 is removed from the inner surface 42 of the retainer 4 by l1F1.
The inner seal part 52 is bent in the direction of 1#, and the inner seal part 52 has a force of 4V 3
There is a tendency to move in the direction of J/C chasing LY゛, but outside I^
After only 1 seal, I felt a little disappointed. At this time, Kito fil
In l, the inner 1111 seal part 52 is formed on the valve body 1 (1/(because it comes into pressure contact with the taper part 11), when the reaction force by the taper 1a1 is absorbed, the taper surface contacts the seal part 52. The applied reaction force is a component force P in the direction perpendicular to the tapered surface of the fluid pressure in the direction of arrow B.

This component force P is a component force Q in the direction perpendicular to the valve plate outer cylinder sealing surface,
The force can be divided into a component force H in a direction perpendicular to the inner surface of the retainer 4. The component force Q deforms the inner seal portion 52 of the seal ring 5 into an elliptical shape extending in the direction of the component force Q within the annular space surrounded by the taper portion 11, the retainer inner surface 42, and the valve plate outer peripheral sealing surface 61. As a result, the inner seal portion 52, which had been floating above the valve plate outer circumferential seal surface 31, is more firmly pressed against the valve plate outer circumferential seal surface 31, and the fluid blocking effect becomes stronger. Figures 1 and 6
As can be seen from the figure, the tapered surface 11 and the valve plate outer peripheral sealing surface 3
By appropriately determining the direction of arrow 1, the suppressing action based on the fluid pressure exerted by the inner seal portion 52 on the outer circumferential sealing surface of the valve plate is made approximately equal even when fluid flows from either direction of arrows A and B. I believe that it is easy to understand that this can be done (by aligning the direction of arrow C in FIG. 1 with the direction of arrow Q in FIG. 6).

- As explained above, by using the sealing mechanism according to the present invention, even when a metal seal ring is used, it can be used against fluid flowing in either the forward or reverse direction without increasing the torque valve operating torque. A substantially uniform sealing action can be obtained, and an even sealing action can be obtained over the entire outer periphery of the valve plate against the flow in any direction, so this combined with the fact that the seal ring is made of metal, The applicable range of eccentric butterfly valves has been greatly expanded,
Furthermore, the present invention has a remarkable effect in that it can be applied to places where other types of valves have been used in the past, allowing the butterfly valve to be replaced.

FIG. 4 shows another application example of the sealing mechanism according to the present invention.
In this device, the inner seal portion 52 in FIG. 1 and 5ν1 is not brought into contact with the tapered portion 11 of the face valve body 1, but is formed in the direction of the valve shaft of the valve body. An auxiliary ring 6 made of bullet ++ gold powder is placed on the four-step portion 12 and is brought into contact with the ring portion 52. In this case, the inner seal portion is approximately circular in radial cross section. The position and shape of the recessed step 12 and the auxiliary ring B are determined so that the common contact kP between the sleeve auxiliary ring 6 and the tapered part 11 is an annular surface that is inclined in the same direction as the tapered part 11. shall be.

By using such an auxiliary ring, the i
'' type 1, the seal portion 52 does not directly contact the tapered portion 11 of the valve body, which is a rigid material, but comes into pressure contact with the sleeve support ring 6, which is an elastic material, so it becomes smaller for a constant fluid pressure, increasing durability. Of course, the elastic action of the auxiliary ring B is not essential.

In the embodiment described above, the valve plate external sealing surface 61
In the above case, the taper on the valve body side is formed into a truncated nail shape, but these surfaces are radial! ! It is not necessary that the conical part is straight when viewed from the + side, but it should be formed as part of a spherical surface with the applicable rotation radius.In short, the valve plate outer cylinder sealing surface 61, of both 4111 surfaces of the valve plate, the radius of the surface closer to the valve shaft is made larger than that of the opposite surface, and a smooth toric surface is formed between them, and the tapered portion 11 is 1. On the other hand, make the radius on the side closer to the valve stem smaller and farther away t.
1] It is obvious that the force relationship as shown in FIG. 6 can be established even if the distances in 1 are made larger and a smooth curved surface is used to connect them.

In addition, both the inner and outer seal parts of the seal ring are
The collar-shaped coil spring inserted in the jk is used to adjust the elasticity of the seal portion and the ring, and depending on the pressure of the fluid, there is no particular difference in operation and effect even if part or all of it is removed.

In addition, in the one shown in Figure 4, a tapered part as shown in Figure 1 is formed between both wall surfaces of the four-step portion 12, and the auxiliary ring is configured to abut and lock on the tapered surface. You can also do that.

- In the embodiment shown in Figure C/Small, the connecting portion 56 is provided with an annular cushion portion 54, but if the connecting portion 56 itself has a predetermined elasticity, the cushion portion 54 may be Of course, there is no need to make a profit.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main parts of an eccentric butterfly valve equipped with a sealing mechanism according to the present invention, FIG. 2 is a partially cutaway perspective view of a seal ring, and FIG.
FIG. 4 is an explanatory diagram showing the sealing action of the seal ring. FIG. 4 is a sectional view of the main part showing another embodiment of the present invention. 1... Valve body, 2... Valve shaft, 6... Valve plate, 4m.
・ Retainer, 5...Seal ring, 6...Auxiliary ring, 11...Taper part, 12・e・Concave step part, 61
・Book・Valve plate outer periphery seal surface, 51...Outer seal part, 5
2...Inner seal portion, 56...Connecting portion, 54...
Cushion Department - Representative Patent Attorney Akira Irie

Claims (1)

[Claims] (1) An annular retainer is fixed to one side of the valve body, and an annular inner seal portion having a substantially circular radial cross section is provided between the side surface of the valve body and the inner surface of the retainer. In an eccentric type valve formed by clamping and fixing the outer periphery of the wall plate-like connecting part of a seal ring having a buried plate-like connecting part on the outside of the inner seal part, the inner seal part of the seal ring is Among both sides of the valve plate, the radius of the side closer to the valve stem is larger than that of the gAII side closer to the retainer, so that a shape b'y L is formed between the two sides.
an outer peripheral sealing surface and a retainer of the valve body.
The radius on the side closer to the retainer is made larger than that on the side closer to the valve stem at the inner end of one plane, and the tapered part formed therebetween is located in a --shaped space formed by a part of the taper and the inner surface of the retainer. Seal mechanism of eccentric butterfly valve. (2. In the sealing mechanism according to claim 1, the tapered portion formed on the valve body is connected to an auxiliary ring disposed at the inner end of the valve body on the retainer side and an inner seal portion of the seal ring. Eccentric butterfly valve sealing machine 11° formed by a common tangent