KR20130040852A - Valve element of butterfly valve - Google Patents

Abstract

An object of this invention is to provide the valve body of a butterfly valve which raises the rigidity of a valve body, and also reduces the operation torque of a valve and makes valve operation easy.
A cylindrical portion extending in the radial direction at the center of the disk-shaped substrate constituting the valve body is formed by raising the front and back surfaces of the substrate, and a valve rod insertion hole is formed in the cylindrical portion, and a plurality of circular ribs intersecting the cylindrical portion. It is characterized in that formed on the front and back of the substrate by concentrically raised. Moreover, the outermost rib was provided along the edge of the board | substrate, and the outer diameter of the center of a cylindrical part was made larger than the outer diameter of an edge part. It is characterized by the above-mentioned.

Description

Valve body of butterfly valve {VALVE ELEMENT OF BUTTERFLY VALVE}

The present invention relates to a valve body of a butterfly valve used for opening and closing of a pipeline through which fluids such as water, gas, oil and the like pass in a piping system.

Conventionally, a circular valve body is pivotally supported in a cylindrical valve box so as to be rotatable, and a pipe line is opened and closed by folding a seat ring made of an elastic member mounted on an inner circumferential surface of the valve box and an outer circumferential surface of the valve body. Butterfly valves are widely used for flow control of various fluids because of their simple structure. In general, a butterfly valve drives and rotates a valve rod by an actuator such as an electric motor or a pressure cylinder to rotate the valve body, thereby folding the valve body outer circumference with a seat ring mounted on the valve box inner circumference to open and close the pipeline. It has a function of adjusting the flow rate of the fluid by changing the flow path area depending on the size of the gap between the valve body outer peripheral portion and the seat ring.

Valve closing is achieved by compression of the valve body outer peripheral portion and the seat ring which is an elastic body. However, in the process of opening and closing the valve body, the interaction force caused by the contact of the valve body outer peripheral portion and the seat ring causes one of the valve operating torques. Therefore, by reducing this interaction force, the operating torque of the valve is reduced and the valve operation becomes easy. In addition, the valve body is under pressure of the fluid passing through the conduit, and at the position where the flow path is completely closed, the entire fluid pressure in the conduit is loaded on the surface of the valve body, and the pressure of the fluid applied to the valve body is maximized. . Since the valve body subjected to fluid pressure is deformed, in order to completely close the conduit, the valve seat seal position of the valve body and the seat ring due to the deformation of the valve body requires a minimum overlapping portion (seal belt), and the valve seat seal In order to maintain the stiffness, high rigidity of the valve body is required.

The method of increasing the rigidity of the valve body can generally be coped by increasing the thickness of the valve body. However, since the mass of the valve body also increases, the cost increases and the weight increases, which causes inconvenience in handling. Then, in order to solve this problem, the method of providing a rib on the valve body surface along the fluid passage direction (patent document 1), and the method of securing rigidity structurally by making hollow inside the valve body (patent document) Document 2) and the like have been proposed. However, in the method of providing the rib in the valve body, the rigidity is high with respect to the stress in the arrangement direction of the rib, but the rigidity of the valve body is lowered in the direction having a predetermined angle with respect to the rib. For example, in the case where the ribs are arranged in the valve body in the same direction as the passage direction of the fluid, the valve body bends when the pressure is received from a direction different from the passage direction (for example, a direction of 45 ° with respect to the ribs), There exists a possibility that a shift | offset | difference may arise in the seal position of a seat ring, and valve seat sealability may fall. In addition, when a butterfly valve is small, since the size of a valve body is restrict | limited, the structural body shape which forms a cavity inside a valve body may not be able to apply to a valve body.

On the other hand, the frictional force generated when the valve body outer peripheral portion presses and slides on the seat ring affects the rotational torque of the valve shaft that rotates the valve body. In particular, when the rigidity of the valve body is low and the valve body is easily deformed, the airtightness must be maintained and the contact area between the valve body outer periphery and the seat ring needs to be increased, so that the frictional force increases and the rotational torque increases. Therefore, in order to improve the operability of the butterfly valve to reduce the energy of the motor that rotates the valve shaft, the rigidity of the valve body is improved, and the shape of the outer peripheral portion of the valve body is improved to reduce the frictional force with the seat ring, thereby reducing the rotational torque of the valve shaft. It is important to suppress it. Therefore, it is proposed that the shape of the mountain seat portion provided on the inner circumferential surface of the seat ring in which the valve body outer circumferential surface contacts is a curved shape of a cosine function starting from the boss portion toward the center between the boss portions through which the valve rod penetrates (patent document). 3).

Japanese Patent Laid-Open No. 2004-239343 Japanese Patent Application Laid-Open No. 9-60751 Japanese Patent Laid-Open No. 55-142169

An object of this invention is to provide the valve body of a butterfly valve which raises the rigidity of a valve body, and also reduces the operation torque of a valve and makes valve operation easy.

1st invention WHEREIN: In the valve body of a butterfly valve, the cylindrical part extended radially in the center of the disk-shaped board | substrate which comprises a valve body is formed in the front and back surface of a board | substrate, and a valve rod insertion hole is formed in this cylindrical part. And a plurality of circular ribs in contact with the cylindrical portion are formed by concentrically raising the front and back surfaces of the substrate.

2nd invention provided the outermost rib along the edge of the board | substrate, It is characterized by the above-mentioned.

3rd invention made the outer diameter of the center of a cylindrical part larger than the outer diameter of an edge part. It is characterized by the above-mentioned.

4th invention makes the thickness of a board | substrate center part largest, the thickness of an outer peripheral part smallest, and the inclination angle of the substrate surface divided by the concentric circular rib to below the inclination angle of the substrate surface adjacent to a center side. It is characterized by one.

The outer periphery of the valve body is composed of a part of the spherical surface, and the outer periphery of the valve body, which is composed of the outermost circular rib and the spherical surface, is connected to the tangent of the outermost peripheral end of the outer periphery part by a straight line having an angle of 30 ° to 50 °. .

According to the present invention, since the cylindrical portion extending in the radial direction at the center of the substrate constituting the valve body is formed by being raised from the front and back surfaces of the substrate, the cylindrical portion becomes a skeleton bearing the strength of the valve body and is also concentric. Since a plurality of circular ribs extending in the shape are raised on the front and back surfaces of the substrate while intersecting the cylindrical portion, a substantially uniform cross-sectional coefficient can be obtained in any cross section at any angle with respect to the valve body center line of the valve body. Since the rigidity of the valve body becomes almost uniform throughout the valve body, a valve body with high rigidity can be obtained. The cylinder is only a very slight deformation since it is the point of the circular rib with respect to the pressure received. Moreover, since the rigidity of the valve outer periphery in the vicinity of the valve rod hole can be improved by the intersection between the cylindrical portion and the circular rib of the valve outer periphery, the sealing stability of the seat ring around the valve rod can be improved.

By making the thickness of the substrate center largest, making the thickness of the outer peripheral portion smallest, and making the inclination angle of the substrate surface partitioned by the concentric circular ribs smaller than the inclination angle of the substrate surface adjacent to the center side, The inclination of the flat portion becomes conical from the center of the valve body toward the outer circumference between the ribs, and since the inclination is the largest in the center and gradually decreases toward the outer circumference, the weight can be reduced while equalizing the cross-sectional strength against pressure. Become.

When the valve body moves from open to closed or from closed to open by connecting the outer periphery of the valve body composed of the outermost circular rib and the spherical surface with a straight line having an angle of 30 ° to 50 ° with the tangent of the outermost peripheral end of the outer periphery. By pressing the elastic body constituting the seat ring, the resistance of the valve body due to the protrusion of the elastic body surface can be eliminated, and the torque resistance due to the interaction between the valve body and the seat ring can be reduced. In addition, the fatigue of the elastic body due to the dragging of the elastic body by the edge portion of the valve body can be minimized, and the opening and closing durability of the valve can be improved. Moreover, since the contact area of a valve body and a seat ring can be enlarged, even if a deformation | transformation arises in a seat ring by contact with a valve body over time, sealing can be maintained.

1 is a front view (A) and YY cross-sectional view (B) of a butterfly valve.
Fig. 2 is a perspective view of the valve body of the first embodiment.
3 is a center cross-sectional view of the cylindrical portion along a center line;
4 is a front view of the valve body of the first embodiment.
Fig. 5 is a center sectional view of the valve body at 90 degrees with respect to the center line of the first embodiment.
Fig. 6 is a center cross sectional view of the valve body at 45 ° with respect to the center line of the first embodiment.
Fig. 7 is a sectional view of the center of the valve body at 30 ° with respect to the center line of the first embodiment.
8 is a principle diagram for reducing a valve body turning torque.
9 is an enlarged cross-sectional view of a valve body outer peripheral portion.
Fig. 10 is a perspective view of the valve body of the second embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the code | symbol 1 is a butterfly valve main body which has a hollow cylindrical flow path, and is a hollow cylindrical flow path with the disk-shaped valve body 2 pivotally supported by the valve rods 3 and 4 rotatably. Is opened and closed. A seat ring 5 made of an elastic body is attached to the inner circumferential surface of the hollow cylindrical portion of the valve body 1, and the outer ring of the valve body 2 is folded to the seat ring 5 to open and close the valve.

2, the valve body 2 is comprised from the disk-shaped board | substrate 6, and has the cylindrical part 7 which inserts a valve rod in the center of the board | substrate 6. As shown in FIG. The cylindrical portion 7 is shaped to be raised from the front and back surfaces of the substrate 6. The shape of the cylindrical portion 7 can increase the cross-sectional coefficient in the direction of the valve body center line 8 and improve the rigidity of the valve body against pressure from the direction perpendicular to the valve body center line 8. The cylindrical portion 7 is hollowed from one end to the other end or hollowed at both ends. Either way, the center of this cylindrical part is easy to mold. In addition, sufficient rigidity can be obtained with a minimum amount of material, and the weight of the valve body can be reduced. In addition, although FIG. 2 is a shape which has the cylindrical part 7 which inserts a valve rod in the center of the board | substrate 6, it is not limited to this shape, The center line of the valve body 8 and the center line of a cylindrical part, ie, the axis of rotation of a valve rod, The so-called eccentric valve body having a certain distance may be used.

3 shows a center cross-sectional view along the valve body centerline 8 of the cylindrical portion 7. In order to improve the rigidity of the valve body 2, the cross-sectional shape of the cylindrical portion 7 is larger than the outer diameter 10 of the valve rod insertion hole, so that the inner diameter of the core portion is larger. (V) 11 is larger than the inner diameter 12 of the valve rod insertion hole. In addition, in the valve body center sectional view of 90 degrees with respect to the valve body center line 8, as shown in FIG. 5, since the cross section area of the cylindrical part 7 is large and a valve body cross section coefficient is large, it is a 90 degree direction with respect to a center line. It becomes possible to make the deformation | transformation of a valve body very small with respect to the force of (up or down direction in FIG. 3). Moreover, since the cross-sectional strength with respect to pressure becomes equal, it is not necessary to add an extra thickness and weight reduction of a valve body is possible.

Depending on the size of the valve body, the outer diameter of the core portion may be smaller than the outer diameter of the valve rod insertion hole. This is because the outer diameter of the core portion decreases with the size of the valve body, but the thickness of the valve rod needs to be maintained for a certain level or more from the viewpoint of strength. In this case, the inner diameter of the core portion is smaller than the inner diameter of the valve rod insertion hole, or the cavity of the core portion is lost.

The ribs 13 are provided in plural concentrically on the front and back surfaces of the substrate 6 (FIGS. 2 and 4), and the ends of each of the ribs 13 are joined to the side surfaces of the cylindrical portion 7, thereby providing uniform rigidity. It becomes a valve body. 5, 6, and 7 show center cross-sectional views of 30 °, 45 °, and 90 ° with respect to the valve body center line of the valve body of FIG. 4, but the section coefficients other than the cylindrical portion of each cross section are approximated, and the valve body is approximated. When the fluid pressure is applied to (2), since the stress of the valve body 2 becomes equal in the whole valve body, the valve body does not deform | transform.

The outermost rib 13 is provided along the edge of the substrate 6, and the ends of the ribs are joined to the cylindrical portion 7 side, whereby the force most applied when the valve rod is inserted, i.e., the valve body is rotated. The rigidity of the part can be improved, and the seal stability of the valve body 2 and the seat ring 5 can be improved.

Next, the shape of the board | substrate 6 is demonstrated using FIG. 5 is a valve body center cross-sectional view of 90 ° with respect to the valve body center line 3. The cross-sectional shape of the board | substrate 6 is thicker, so that it is closer to a cylindrical part (center), and thinner, so that it is closer to an edge end (outer periphery). In addition, the surface of the board | substrate partitioned by the ribs 13 is surface 1, surface 2,... , Planes (n-1) and planes n, and the inclination angles with respect to the substrate center of each plane are denoted by α1, α2,. ,? (n-1) and? n, the inclination angle of the substrate is? 1?? 2? ?? N-1?? N? By setting it as such a shape, the cross-sectional strength with respect to pressure becomes equal and weight reduction becomes possible.

FIG. 8: shows the principle diagram explaining reduction of the rotational torque of a valve body according to the edge shape of the valve body outer peripheral surface. The valve body is closed in the arrow direction or open in the opposite direction. For example, when the operation of closing the valve body in the direction of the arrow in Fig. 8 is performed, the surface of the elastic body constituting the seat ring pressed by the edge portion 15 of the valve body protrudes to become a resistance of the valve body closing operation. The valve body edge portion 15 of the present invention connects the spherical machining portion and the rib of the outer peripheral portion 16 of the valve body by a straight line having an angle of 30 ° to 50 ° with a tangent of the outermost circumferential end of the outer peripheral portion 16, Protrusion of the elastic body behind the valve body edge was suppressed, and resistance by the protrusion of the elastic body was minimized. As a result, the resistance to the valve body was eliminated, thereby reducing the torque resistance due to the interaction force between the valve body and the seat ring. In addition, the fatigue of the elastic body due to the attraction of the elastic body by the edge portion of the valve body is minimized, and the opening and closing durability of the valve is improved.

Fig. 9 shows an enlarged cross section of the valve body outer peripheral portion. It shows the shape which connects the spherical-processed part and rib of the outer peripheral part 16 of a valve body with the straight line whose angle (alpha) of the tangent of the outermost circumferential end of the outer peripheral part 16 is 30 degrees-50 degrees. The angle α affects the protrusion of the elastic body by the edge portion 15 of the valve body. By setting this to 30 ° to 50 °, the resistance due to the protrusion of the elastic body is minimized while maintaining the airtightness of the valve body. It is. That is, when smaller than 30 degrees, resistance will increase, and when larger than 50 degrees, there exists a possibility that seal stability may not be maintained. Moreover, it is most preferable that angle (alpha) is 45 degrees.

1 body 2 valve body
3: upper valve rod 4: lower valve rod
5: sheeting 6: substrate
7: cylindrical portion 8: valve body centerline
9: outer diameter of core part 10: outer diameter of valve rod insertion hole
11: inner diameter of core part 12: inner diameter of valve rod insertion hole
13: rib 14: protrusion of the seat ring
15: edge portion 16: outer peripheral portion

Claims (5)

A cylindrical portion extending in the radial direction at the center of the disk-shaped substrate constituting the valve body is formed by raising the front and back surfaces of the substrate, and a valve rod insertion hole is formed in the cylindrical portion, and a plurality of circular ribs intersecting the cylindrical portion. The valve body of a butterfly valve, characterized in that it is formed by raising concentrically on the front and back of the substrate. The valve body of a butterfly valve according to claim 1, wherein an outermost rib is provided along an edge of the substrate. The butterfly valve valve according to claim 1 or 2, wherein an outer diameter at the center of the cylindrical portion is made larger than an outer diameter at an end portion. The inclination angle of the substrate surface according to any one of claims 1 to 3, wherein the thickness of the center portion of the substrate is the largest, the thickness of the outer peripheral portion is the smallest, and is partitioned by concentric circular ribs. The valve body of a butterfly valve characterized by below the inclination angle of the adjoining substrate surface. The valve outer periphery of any one of Claims 1-4 which comprises the outer peripheral part of a valve body by a part of spherical surface, and the tangent of the outer peripheral part of the outer peripheral part of a valve rib outer peripheral part which consists of a circular rib and an outer peripheral part 30 degree- A valve body of a butterfly valve, which is connected in a straight line having an angle of 50 °.

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