JPS6244146B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a spherical valve, and particularly to a spherical valve suitable as a large diameter, high water pressure spherical valve used as an inlet valve for a hydroelectric power plant. [Prior art] In recent years, in hydroelectric power generation, there has been a remarkable development of pump turbines that utilize surplus electricity at night, and with this, the single output of a water turbine is determined by the amount of surplus electricity, so large-output It has become possible to construct power plants, and spherical valves with large diameters and high water pressure are required as inlet valves used there. FIGS. 1A to 1C are explanatory diagrams respectively showing conventional spherical valves, in which bearings are provided on both sides of a valve body 1, valve shafts 2 are provided on both sides,
It supports a valve body 3 in which a cylindrical flow path and a sealing ring are formed. An operating lever 4 is connected to the end of the valve shaft 2,
The valve body 3 is set to a predetermined opening position by an operating lever 4. In these spherical valves, the valve body, the valve stem 2, and the valve body 3 are formed as individual strong parts, and each part has an escape area so that the parts do not interfere with each other when changing their positions. It is given and collected. That is, in the spherical valve shown in FIG. 1A, the thrust ring 5A attached to the valve shaft 2 protruding to the left in the figure is fixed to the valve body 1 with a fastening bolt 6, and the thrust ring 5A is fixed to the valve body 1 with a fastening bolt 6. The valve body 1 and the valve stem 2 are allowed to move relative to each other. Furthermore, in the spherical valve shown in FIG. 1B,
Thrust rings 5B are installed between both sides of the valve body 3 and the left and right inner surfaces of the valve body 1, so that the left and right valve shafts 2 are movable toward the center of the valve body 1. Furthermore, in the spherical valve shown in FIG. can be moved relative to the left. [Problems to be Solved by the Invention] However, in these conventional spherical valves, as the capacity of the valve increases, the installation size and weight increase, and the amount of leakage from the water sealing part tends to increase. . In addition, in a spherical valve as shown in FIGS. 1A and 1C, the valve stem 2 on either side of the valve body 3 is movable with respect to the valve body 1, and the upstream seal or the downstream seal At the time of sealing, the valve body 3 is
is expanded or contracted in the valve axis direction, so that the valve body 1
However, since the valve stem 2 changes in the axial direction, the sealing mechanism between the valve body side and the valve body side becomes misaligned, and the amount of leakage increases. Furthermore, in a spherical valve as shown in FIG. As the valve body contracts and deforms, and the valve body deforms outward from the valve shaft, the sealing mechanism between the valve body side and the valve body side becomes unstable, resulting in an increase in the amount of leakage. The present invention has been made in view of the above-mentioned conventional problems, and can be used for both upstream seal type and downstream seal type, and can be made smaller and lighter.
It is an object of the present invention to provide a spherical valve that can prevent leakage from a water sealing part. [Means for Solving the Problems] The present invention provides a valve body in which a cylindrical flow path is formed, and a pair of valves provided on both sides of the valve body and substantially perpendicular to the cylindrical flow path. In a spherical valve having a shaft and a valve body formed with a bearing portion rotatably supporting the pair of valve shafts and housing the valve body, the valve body of the valve shaft and the valve body A pair of inner and outer thrust rings are provided between the valve body and the outside of the bearing portion, respectively, and when the upstream side is sealed, the valve body is deflected toward the outside of the valve shaft due to water pressure applied to the surface of the valve body on the upstream side. When the inner thrust ring presses the bearing part to disperse the deflection force acting on the valve body and seal the downstream side, internal water pressure causes the valve body to move in a direction perpendicular to the valve shaft. A spherical valve characterized in that when the valve body deflects in an outward direction of the valve stem, the outer thrust ring presses the bearing portion to cancel the deflection force acting on the valve body and the valve body. It is. [Function] In the present invention configured as described above, when the upstream side is sealed, the water pressure acting on the upstream surface of the valve body is dispersed to the valve body by pressing the bearing part with the inner thrust ring, In addition, when the downstream side is sealed, the external thrust ring prevents the deflection deformation in which the valve body contracts inward in the valve shaft direction and the valve body expands outward in the valve shaft direction due to the water pressure that acts inside. The above purpose is achieved by pressing the two so that they cancel each other out. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIGS. 2 and 3 are explanatory diagrams showing one embodiment of the spherical valve according to the present invention. Bearing portions 11 provided on both sides of the valve body 11
A valve shaft 12 is supported through the valve body 11, and a valve body 13 that is integrated with the valve shaft 12 is housed inside the valve body 11. An operating lever 14 is fixed to the end of one valve shaft 12, and the operating lever 14 is connected to a servo motor 15.
The valve body 13 is connected to a predetermined opening position to set the valve body 13 at a predetermined opening position. An inner thrust ring 21 externally fitted onto the valve shaft 12 is interposed between the valve body 11 and the valve body 13 on the inner side of the bearing portions 11A on both sides. Furthermore, an outer thrust ring 22 that is fitted into a circumferential groove of the valve shaft 12 is provided on the outer side of the bearing portions 11A on both sides. The inner thrust ring 21 and the outer thrust ring 22 are connected to a bearing portion 11A in order to position the valve body 11 and the valve body 13 at predetermined positions and to distribute and bear the external force acting on the valve body 13 on the valve body 11. The valve shaft 12 is coupled so as not to move relative to the valve shaft 12 in the axial direction. Next, the operation of the above embodiment will be explained with reference to FIGS. 4 and 5. FIG. 4 is an explanatory diagram showing the water pressure-displacement state during upstream sealing. As shown in Figure 4, when the upstream side is sealed,
Water pressure W acts on the upstream surface of the valve body 13 from the water channel, and the valve body 13 receives a force that bends the valve shaft 12 outward. At this time, the inner thrust ring 21 provided between the valve body 11 and the valve body 13
touches the inside of the As a result, the valve body 13 is prevented from deforming from the shape shown by the solid line to the shape shown by the two-dot chain line, and the deflection force acting on the valve body 13 is transferred to the valve body 11 through the inner thrust ring 21 and the bearing portion 11A.
distributed and alleviated. FIG. 5 is an explanatory diagram showing the water pressure-displacement state during downstream sealing. As shown in FIG. 5, when the valve body 13 seals the downstream side, water pressure W acts on the inner surface of the valve body 13 and also on the inner surface of the valve body 11. Therefore, the valve body 13 receives a force that bends in a direction perpendicular to the valve shaft 12, and the reaction force D causes the valve shaft 12 to bend.
is moved inward, and the valve body 11 is deflected in the outward direction of the valve shaft 12. Therefore, the outer thrust ring 22 provided on the valve stem 12 presses the bearing portion 11A inward. As a result, the valve body 13 is prevented from deforming from the shape shown by the solid line to the shape shown by the two-dot chain line, and the valve body 11 is prevented from deforming outward from the valve shaft, and the valve body 13 and the valve body 13 are prevented from deforming outward from the valve shaft. The deflection force acting on the shell 11 is offset. According to the above embodiment, the valve body 11, the valve shaft 12, and the valve body 13 are integrated so as not to move relative to each other by the inner thrust ring 21 and the outer thrust ring 22, so the configuration of each component is set small. However, since the overall configuration can be enlarged,
The spherical valve can be made lighter and smaller. In addition, it is possible to mutually disperse or offset the loads (flexural forces) that act on each component when an external force is applied, thereby reducing deformation of the valve body 11 and valve body 13, stabilizing the sealing mechanism, and reducing the amount of leakage. can. Note that the outer thrust ring will now be described.Next, specific effects of the spherical valve according to the embodiment will be explained. As a concrete spherical valve, the valve diameter is 2m and the head is 500.
Assuming a spherical valve for m, the inner radius of the valve body _R1 is 160
cm, the valve body plate thickness t ₁ is 10 cm, the valve orifice radius R ₂ is 100 cm, and the valve body cylinder plate thickness t ₂ is 5 cm. Here, if the spring constant of the valve body is K ₁ and the spring constant of the valve body is K ₂ , then the composite spring constant K ₀ when the valve body and the valve body are combined as shown in FIG.
is K ₀ = K ₁ + K ₂ ...(1). In addition, in general, the spring constant K of a curved beam is given by the following: load is W, deflection is δ, bending radius is R, longitudinal elastic modulus is E, and moment of inertia is: becomes. Here, the second moment of area per unit width is I=t ³ /12 (3). Also, the deflection of the ring in the x and y directions δx
and δy is δx≒WR ³ /EI(2/π-1/2)...(4
) δy≒WR ³ /EI(π/4-2/π)……(5
) becomes. That is, C in equation (2) is a constant, and therefore, the spring constant K is expressed as K∝EI/R ³ (6). Therefore, K ₁ ∝E/12 (t ₁ /R ₁ ) ³ = E/12× 2.44×10 ^-4 (Kg/cm) ...(7) K ₂ ∝E/12 (t ₂ /R ₂ ) ³ =E/12× 1.25×10 ^-4 (Kg/cm) ……(8) K ₀ =K ₁ +K ₂ ∝E/12× 3.69×10 ^-4 (Kg/cm) ……(9) . That is, for both the upstream seal and the downstream seal, the rigidity ratio between the spherical valve having the structure according to the embodiment and the spherical valve having a structure in which the valve body alone supports water pressure as in the conventional example is K ₀ /K. ₂ = 2.95 (10) According to the example, the displacement of the valve body can be reduced to 1/3, making it possible to manufacture a spherical valve with excellent sealing performance. Further, in the downstream seal, according to the spherical valve according to the embodiment, it is possible to offset or reduce the state in which the valve body tends to expand due to internal pressure by the opposite reaction force acting on the valve body. Therefore, the stiffness ratio of the valve body is K ₀ /K ₁ = 1.5 (11). Furthermore, for a conventional spherical valve with the same capacity, it is possible to reduce the rigidity of the valve body by 2/3 and the valve body by 1/3, and converting this into weight, the valve weight is approximately

[Formula] makes it possible to reduce the valve by 31%. Torso weight is approximately

〔Effect of the invention〕

As explained above, according to the present invention, a pair of thrust rings are provided on the inside and outside of the bearing, and the thrust rings disperse and cancel out the deflection force acting on the valve body and the valve body. Moreover, a spherical valve that is lightweight and can prevent leakage can be obtained.

[Brief explanation of the drawing]

1A to 1C are cross-sectional views showing a conventional spherical valve, FIG. 2 is a cross-sectional view showing a spherical valve according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along the line - in FIG. 2. 4 and 5 are explanatory diagrams showing the operating state of the embodiment, respectively, and FIG. 6 is an explanatory diagram showing the same spring system. DESCRIPTION OF SYMBOLS 11... Valve body, 11A... Bearing part, 12... Valve shaft, 13... Valve body, 21... Inner thrust ring, 22... Outer thrust ring.

Claims (1)

[Scope of Claims] 1. A valve body in which a cylindrical flow path is formed, a pair of valve shafts provided on both sides of the valve body and substantially perpendicular to the cylindrical flow path, and the pair of valves. In a spherical valve having a bearing portion rotatably supporting a shaft, and a valve body housing the valve body, the valve body includes a space between the valve body and the valve body of the valve shaft and an outer side of the bearing portion. are provided with a pair of inner and outer thrust rings, respectively, and when the valve body is deflected toward the outside of the valve shaft due to water pressure applied to the surface of the upstream valve body when the upstream side is sealed, the inner thrust ring is bent. By pressing the bearing part, the deflection force acting on the valve body is dispersed, and when the downstream side is sealed, the internal water pressure
When the valve body is bent in a direction perpendicular to the valve stem and the valve body is deflected in an outward direction of the valve stem, the outer thrust ring presses the bearing portion and acts on the valve body and the valve body. A spherical valve characterized by counterbalancing deflection forces.