JPS62165072A - Butterfly valve - Google Patents

Abstract

PURPOSE:To prevent the drive transmitting part of a valve body from being subjected to concentrated load by inserting a cylindrical seal ring which is brought into contact with a cutout part provided on said valve body, into a part of a body liner through which a rotary shaft is inserted. CONSTITUTION:In a butterfly valve 1, all of a body liner 2, valve body 3, seal rings 4a, 4b, and two-divided rotary shafts 5a, 5b are fixed by two-divided housings 6a, 6b. The body liner 2 has a circular inner face while having holes 7a, 7b for fitting in cylindrical seal rings 4a, 4b on the top and bottom ends respectively. The seal rings 4a, 4b are pressed against cutout parts 9a, 9b which are the opposite flat faces of the valve body 3, by means of coned disk springs 8a, 8b. Thereby, the valve 1 is always kept liquid tight in the axial direction in spite of the opening/closing operation of the valve body 3.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a butterfly valve, and more particularly to a butterfly valve whose wetted parts are made of ceramic with excellent wear resistance and chemical resistance. be.

(Prior Art) FIG. 5 is an assembly diagram showing an embodiment of a conventional butterfly valve in partial cross section. In FIG. 5, a conventional butterfly valve 21 is constructed by fixing a ceramic body liner 22, a ceramic valve body 23, and a rotating shaft 24 that transmits rotational force to the valve body 23 with two housings 25a and 25b. There is. For valves that handle corrosive liquids,
Liquid leakage from the shaft to the outside generally corrodes the external parts of valves that are not made of highly corrosion-resistant materials, and also pollutes the environment, so the sealing performance of this shaft is important for valves. Needless to say, it is a function. Therefore, a configuration in which the entire body liner is made of an elastic material such as rubber and the shaft portion is closed, including the closure in the direction of the flow path, is shown in Japanese Patent Publication No. 57-23827, for example.
For valves whose wetted parts are made of ceramic and have improved wear and chemical resistance, it is not a suitable configuration to use elastic materials such as rubber, which have lower wear and chemical resistance than ceramics. Therefore, in order to increase the contact area for the shaft part, a body liner 2 is installed as shown in FIG.
The inner surface of 2 has a non-circular cross section consisting of flat parts 22a and 22b, an arcuate cross section, and a small diameter roundness (hereinafter referred to as R) connecting the two surfaces to prevent stress concentration at the acute angle inner edge part of the ceramic. , the flat portion 22a.

22b comes into contact with the valve body 23, so that even when the valve body 23 is opened or closed, the axial direction is always liquid-tight, and the structure is excellent in the liquid sealing performance of the shaft portion. On the other hand, if the inner surface of the body liner 22 has a circular cross-section, the outer diameter of the valve body that opens and closes the fluid passage will be the same as the body liner at any valve opening degree with respect to the circular cross-section of the body liner 22. In order to avoid interference, it is necessary to make the valve body a part of the spherical shape. However, as mentioned above, the outer periphery of the valve body and the inner surface of the body liner are only in line contact at the shaft portion, but this structure does not provide sufficient sealing performance. As disclosed in the publication, the body liner is also required to be part of the spherical shape, but machining the inner spherical surface is extremely difficult when it is made of ceramic. Furthermore, the connection between the valve body 23 and the rotation @ 24 can be achieved by, for example, installing a square hole 23a with a square cross section perpendicular to the axis in the ceramic valve body 23, as shown in FIG. 7, and inserting the rotation shaft 24 into this square hole 23a. ,
They fit together and transmitted rotational force.

(Problems to be Solved by the Invention) In the conventional butterfly valve 21 described above, since the inner surface of the body liner 22 serves as a sealing surface, high dimensional accuracy and surface finishing accuracy are required. If you try to manufacture this sealing surface by machining, there will be a mixture of curved and flat surfaces, so if you use an NG milling machine, for example, a grinding wheel with a diameter twice the radius of the small diameter R that connects the flat surface and the arc-shaped cross section will be used. If you rotate it, you can process it. However, the diameter of the grinding wheel is generally as small as 2 On+mφ or less, making high-speed grinding impossible due to the circumferential speed of the grinding wheel, and because the rigidity of the grinding wheel is low, chatter often occurs. Furthermore, in order to eliminate this drawback, it is conceivable to increase the diameter of the radius R. This R can be expanded to the inscribed circle of the shape formed by the flat parts 22a and 22b and the arcuate cross section, but in order to form the shape of the valve body corresponding to this shape, For example, processing by NC is required, and the oval body liner shape has the disadvantage that polishing is extremely difficult in any case.

In addition, if the non-circular cross-sectional shape of the body liner is formed by press molding, casting, etc. in the unfired state of Reramix without performing machining after firing the ceramics, the non-circular cross-sectional shape as described above will occur. Since the cross section is a sealing part, it is clear that both dimensional accuracy and surface accuracy do not satisfy the sealing performance of the valve.

On the other hand, the connection between the valve body 23 and the rotating shaft 24 is achieved by installing a square hole 23a with a square cross section perpendicular to the axis in the ceramic valve body 23, and inserting and fitting the rotating shaft 24 into this square hole 23a to apply rotational force. Because of the transmission structure, the rotational force applies intensive Ai4 to the portion where the rotating shaft 24 and the valve body 23 are in contact with each other.

For this reason, for example, if a valve is closed with liquid crystals attached to the outer circumference of the valve body, the rotational force to close the valve will be large.
Particularly, the ceramic is damaged at the portion where the rotating shaft 24 and the valve body 23 are in contact with each other.

In order to avoid this problem, increasing the wall thickness of the cylindrical hole portion of the valve body has the drawback of reducing the cross-sectional area of the flow path of the valve and increasing the fluid resistance of the valve.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems and provide a butterfly valve having a simple structure in which the main parts are machined by lathe processing and other circular cross-sectional shapes.

Still another object of the present invention is to provide a ceramic butterfly valve in which ceramics are less likely to be damaged due to concentrated loads in the driving force transmission section of the valve body, and the flow rate of fluid can be reliably adjusted by opening and closing the valve. be.

(Means for Solving the Problems) The butterfly valve of the present invention has a body liner inner surface as a fluid flow path, a valve body that opens and closes the fluid flow path on the inner surface to adjust the flow rate, and a In a butterfly valve having a rotating shaft centered at two points and transmitting rotational force for opening and closing to the valve body, the inner surface of the body liner is circular, and a portion of the body liner through which the rotating shaft passes through the butterfly valve. A cylindrical seal ring that contacts a notch provided in the body is inserted through the valve body, and the contact between the valve body and the seal ring makes the valve body highly liquid-tight in the axial direction even when the valve body is opened and closed. It is something.

(Function) In the structure described above, the body liner is circular;
Since the part corresponding to the flat part of the conventional body liner is formed by one end surface in the axial direction of the cylindrical seal ring, each part can be easily processed. In addition, since the rotating shaft is connected via a metal sleeve inserted and fixed into a cylindrical hole opened in the axial direction from the notch of the valve body,
It is possible to reduce the occurrence of damage to ceramics due to concentrated loads at the driving force transmission portion of the valve body.

(Embodiment) FIG. 1 is an assembly diagram showing, in partial cross section, one embodiment of the butterfly valve of the present invention. Butterfly valve 1 of this embodiment
are body liner 2, valve body 3, seal rings 4a, 4
b, and a housing 5a in which the entire rotating shaft 5a, 5b is divided into two parts.

It is formed by fixing with 6b. The body liner 2 has a circular inner surface, and has holes 7a and 7b at its upper end and opposing lower end into which cylindrical seal rings 4a and 4b are fitted. The cylindrical seal rings 4a, 4b fitted in the holes 7a, 7b are cut out by the elastic force of disc springs 8a, 8b provided on the pedestals in the housings 6a, 6b, so that the notches 9a, which form opposing planes of the valve body 3,
9b is pressed. Therefore, the seal ring 4a.

4b and the notches 9a and 9b always come into contact with each other in a flat plane no matter what position the valve body 3 is rotated, and the axial direction is always kept liquid-tight regardless of whether the valve body 3 is opened or closed. It will be done. Also, a seal ring 4a.

4b has O-rings 16a and 16, respectively.
A groove is provided for fixing the body liner 2, and the gap between the body liner 2 and the holes 7a and 7b for fitting the seal rings 4a and 4b of the body liner 2 is liquid-tight. Also, a seal ring 4a.

4b is fixed to the body liner 2 by the frictional force in the circumferential direction of the O-rings 16a and 16b, but if necessary, seal rings 4a and 4b (not shown)
An axial groove is provided on the outer periphery of the cylindrical portion of the housings 6a, 6.
Rotation in the circumferential direction may be prevented by using a set screw, key, etc. between the

Seal rings 4a, 4b and notch 9a of valve body 3.

9b is suppressed liquid-tight by the elastic force of the disc springs 8a and 8b as described above, but if the corresponding contact surface is damaged,
O-rings 16a and 16b are used as secondary seals to prevent the rotating shaft 5a from coming into contact with liquid.
, 4b is installed on the inner diameter side of the contact surface with the valve body.

In this embodiment, the rotary shaft that transmits the driving force to the valve body 3 is divided into two parts, and the rotary shaft 5a is inserted and fitted into a metal sleeve 10 provided coaxially inside the valve body 3. The metal sleeve 10 is inserted into a cylindrical hole opened in the axial direction from the notch 9a of the valve body 3, and the outer diameter of the sleeve 10 and the inner diameter of the cylindrical hole are bonded with resin or bonded with a low melting point. For small valves that are fixed with metal, but have small rotational torque or small valve rotation force due to uneven fluid pressure in the valve body, the inner diameter of the metal sleeve and the inner diameter of the cylindrical part of the valve body. by brazing metal and ceramics, or by making the inner diameter of the cylindrical part smaller than the outer diameter of the metal sleeve, heating the valve body to make it larger than the outer diameter of the metal sleeve, and then removing the metal sleeve. A shrink fit method may also be used, in which the valve body is inserted and fixed as it cools.

Further, the outer diameter of the metal sleeve may be provided with a knurl or the like to prevent slipping if necessary, and the inner diameter of the metal sleeve is square in cross section perpendicular to the axis in this embodiment, so that the tip of the rotating shaft 5a to be inserted and fixed is also Correspondingly, the cross-sectional shape is square, but it is of course possible to use a transmission structure such as a key or spline. Further, the rotating shaft 5a may be supported by either the seal ring 4a or the housing 6a. Further, the rotating shaft 5b is configured to be inserted into a cylindrical hole 11 opened in the axial direction from a notch 9b provided at the lower part of the valve body 3, and the rotating shaft 5b is supported by either the seal ring 4b or the housing 6b. You can go. Further, the sliding portion of the rotating shaft 5b may be connected to the cylindrical hole 11 of the valve body and the rotating shaft 5b, or to the rotating shaft 5b and the bottom of the housing 6b. The entire structure described above has two housings 6a and 6b connected to bolts 12a,
The butterfly valve 1 is constituted by fixing with 12b.

FIG. 2 is an assembled view, partially in section, of another embodiment of the butterfly valve of the present invention. In this embodiment, the same members as those shown in FIG. 1 are given the same reference numerals, and their explanations will be omitted. The difference between this embodiment and the embodiment shown in FIG. 1 is that the rotating shaft is not divided into two parts, but a single rotating shaft 13 is fixed by a metal sleeve 14 provided over the entire center of the valve body 3. be. In this case, the rotating shaft 13 and the metal sleeve 14 are also fixed by any of the methods described above.

FIG. 3 is a diagram showing the relationship between the body liner 2 and seal rings 4a and 4b used in the butterfly valve of the present invention. As is clear from FIG. 3, the inner surface of the body liner 2 of the present invention is circular and has holes 7a at positions through which the seal rings 4a and 4b are inserted.

7b, the processing of the body liner 2, particularly the processing of the inner surface, which requires strict dimensional accuracy and surface finishing accuracy, can be made much easier than in conventional methods. In addition, the seal rings 4a and 4b also have holes 7
It is only necessary to have a cylindrical shape that can be inserted into holes a and 7b, and the processing is simple. By combining the body liner 2 with the seal rings 4a, 4b, a flat surface that comes into contact with the planar cutouts 9a, 9b of the valve body 3 can be created.

FIG. 4 is a view of the valve body used in the butterfly valve shown in FIG. 1 of the present invention, viewed from the end in the direction of the rotation axis. In this embodiment, the metal sleeve 1 provided in the notch 9a of the valve body 3
An example is shown in which the inner surface of 0 is a square hole 15. in this case,
The end of the rotating shaft 5a connected to the square hole 15 of the metal sleeve 10 is also inserted into the square hole 15 in a square shape.

In the above-described embodiment, the body liner 2, the valve body 3, and the seal rings 4a, 4b are preferably made of ceramics such as zirconia, alumina, silicon nitride, and silicon carbide, but the materials are limited thereto. The functions and effects of the present invention can be achieved using any material.

(Effects of the Invention) As is clear from the detailed explanation above, according to the butterfly valve of the present invention, all parts are processed in a circular shape, and each part requires high dimensional accuracy and surface roughness. can be easily done in a short time. In addition, a seal ring and a disc spring are combined to press the notch of the valve body.
Since it has a structure that is liquid-tight in the axial direction, even if the seal ring and the notch of the valve body wear out, a suitable sealing surface can still be obtained, resulting in good durability. Furthermore, since a metal sleeve with a circular outer periphery is attached to the valve body, and this metal sleeve and the valve body are joined, the driving force from the rotating shaft is evenly distributed and transmitted to the valve body, and the driving force is transmitted to the valve body partially. It is possible to provide a valve with small pressure loss without the need to increase the thickness of the rotating shaft portion of the valve body, and without reducing the degree of opening in the direction of the flow path. can.

[Brief explanation of drawings]

FIG. 1 is an assembly diagram showing an embodiment of the butterfly valve of the present invention in partial cross section, FIG. 2 is an assembly diagram showing another embodiment of the butterfly valve of the present invention in partial cross section, and FIG. Figure 4 is a diagram showing the relationship between the body liner and seal ring used in the butterfly valve; Figure 4 is a view of the valve body used in the butterfly valve shown in Figure 1 of the present invention viewed from the end; The figure is an assembly diagram showing a partial cross section of an example of a conventional butterfly valve. Figure 6 is a diagram showing a body liner used in a conventional butterfly valve. Figure 7 is a valve body used in a conventional butterfly valve. FIG. 1...Butterfly valve 2...Body liner 3
... Valve body 4a, 4b... Seal ring 5a, 5b, 13-11 rotation N 6a, 5b... Housing 7a, 7b, 11-... Hole 8a, 8b
-11n wings 9a, 9b...notch 10.14
...Metal sleeves 12a, 12b...Bolts
15... Square hole 16a, 16b-0 ring 17
a, 17b-0 ring Patent applicant: Chubu Electric Power Co., Ltd. Applicant: Nippon Insulators Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4'/at-An Katochashi P Figure 5

Claims (1)

[Scope of Claims] 1. A valve element whose inner surface of the body liner is used as a fluid flow path, and which opens and closes the fluid flow path on the inner surface to adjust the flow rate; In a butterfly valve having a rotating shaft that transmits rotational force for opening and closing, the inner surface of the body liner is circular, and a part of the body liner through which the rotating shaft is inserted comes into contact with a notch provided in the valve body. A butterfly valve, characterized in that a cylindrical seal ring is inserted therethrough, and the valve body and the seal ring are in contact with each other to make the axial direction liquid-tight. 2. The butterfly valve according to claim 1, wherein the body liner, valve body, and seal ring are made of one or more of zirconia, alumina, silicon nitride, and silicon carbide. 3. The valve body is provided with a cylindrical hole in the axial direction from the notch, and a metal sleeve having a rotational force transmission structure in the inner diameter portion is inserted and fixed into the cylindrical hole, and the rotating shaft is inserted into the metal sleeve. The butterfly valve according to claim 1, wherein the butterfly valve is configured to transmit rotational force by being connected to the inner diameter portion of the sleeve. 4. The scope of claims in which the cylindrical hole provided in the notch of the valve body and the metal sleeve are fixed by any one of adhesion with resin or low-melting point metal, brazing of metal and ceramics, or shrink fit. The butterfly valve described in item 3.