JPS6011328Y2 - butterfly valve - Google Patents

Description

[Detailed Description of the Invention] The present invention particularly relates to a butterfly valve with an improved valve seat shape.

Conventionally, even under harsh usage conditions as a water stop valve seat material,
Butterfly valves are well known, which employ metal materials with excellent corrosion resistance in order to ensure stable water-tightness over a long period of time.

This type of conventional butterfly valve, for example, JP-A-53-493
The butterfly valve as disclosed in the 3rd publication is the first
As shown in Fig. 2, the valve seat 3' of the valve body 3 is brought into close contact with the valve seat 1' of the valve body 1 by a predetermined area to shut off water.
The contact state between the valve body valve seat 3' and the valve body valve seat 1' is a surface contact, and under the same axial torque, the surface pressure per unit area is lower than in the case of a line contact, and therefore the water-stopping property is reduced. Inferior.

Further, as the neck portion 3a of the valve body 3 is approached, the valve seat 1',
Since the angle 3' becomes smaller, contact pressure between the valve seats 1' and 3' due to the rotation of the valve body 3 around the shaft 4 is less likely to occur, so water is stopped due to the influence of the bulge of the valve body 1 due to internal pressure. becomes difficult.

Further, since the valve seats 1' and 3' are in surface contact, there are other problems such as a large torque being required to open and close the valve body.

This invention was made to solve the above problems.
It is an object of the present invention to provide a butterfly valve that easily generates contact surface pressure of a valve seat on the outer periphery near the neck of a valve body to improve water-stopping performance and has a small water-stop torque.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

FIG. 3 is a side view of this embodiment, and FIGS. 4a and 4b are sectional views taken along lines IV--IV and --- in FIG. 3, respectively.

In this figure, the same members as those of the conventional example shown in FIGS. 1 and 2 are given the same reference numerals.

In the figure, xx' indicates the central axis of the cylindrical valve box 1 to which the valve of the present invention is attached.

In addition, E1 in the same figure has its central axis GG' as the central axis X-
An imaginary cylinder having a shape of a valve box valve seat 1' and inclined at an angle Q1 with respect to the X' axis and having a diameter, and the valve box valve seat 1' is formed in the same shape as the outer periphery of this imaginary cylinder E1. Ru.

Furthermore, E2 is its central axis) 1-H' is the central axis X-X'
An imaginary cylinder on the valve body valve seat 3' shape having an angle θ2 (here, θ2<θ□) and a diameter D2 (here, D2>D□) with respect to the axis, and this virtual cylinder E2. A valve body valve seat 3' is formed in the same shape as the outer periphery.

The central axis G of the virtual cylinders E1 and E2 shown in FIG.
When -G' and H-H' are concentrically polymerized, the polymerization axis is expressed as ni-ni' as shown in FIG.

In this Fig. 5, the elliptical outer circumference of the virtual cylinder E1 cut along the -c' line is tilted at an angle of θ The long P1 is
Virtual cylinder E1 in FIG. E2 is the virtual cylindrical E work shown in Fig. 3,
Since this is simply a replacement of the coordinates of E2, it corresponds to the outer circumferential length of the valve body valve seat 1' when fully closed as shown in FIG.

Similarly, an imaginary cylinder E cut along line 33-B' inclined at an angle of 02 in the side direction from the Ya-Y'a axis.
The outer circumferential length P2 of the ellipse 2 indicates the outer circumferential length of the valve body valve seat 3' when the valve body is fully closed.

Also, along the Y-Y' axis in Fig. 3, virtual cylinders E and E
2 (valve box valve seat 1' and valve body valve seat 3') has an elliptical shape as shown in FIG.

In this case, in the z-z'' direction, the diameter of the valve body valve seat 3' is larger than the diameter of the valve body valve seat 1', and in the Y-Y' axis direction, the diameter of the valve body valve seat 3' is larger than the diameter of the valve body valve seat 1'. It is smaller than the diameter of the box valve seat 1'.

Therefore, when determining the shapes of the valve body valve seat 3' and the valve body valve seat 1' in order to bring the valve body valve seat 3' into close contact with the valve body valve seat 1' to stop water, it is necessary to In the approximate expression for the elliptical outer circumference length P□ of valve body valve seat 3' and the approximate expression for the elliptical outer circumference length P2 of the valve body valve seat 3', first set Dl and 01, then set D2, and P□=P2. Then, calculate 02.

Note that when setting θ□ and D2, θ1 is usually 4 to
It is set appropriately within the range of 10 degrees, and D2 is expressed as D2=D1+δ, where δ is the amount of bulge that the valve box deforms due to the water pressure of the pipe connected to the butterfly valve, etc.
Although it varies depending on the size of Dl and the water pressure of the pipe, it is usually set appropriately in the range of 0.015 to 0.2 rrrm.

As described above, in this embodiment, the valve body valve seat 3' can be closely attached to the valve body valve seat 1', and the virtual cylinder E1 is inclined at angles θ1 and θ2 from the central axis x-x' axis of the valve body 1. and the valve body valve seat 1' and the valve body valve seat 3 so that they are the same as the outer circumference of E2.
', and also θ□〉θ2, diameter D1 < D2, and the outer circumferential length on the Y-Y' axis cut plane including the valve shaft perpendicular to the valve body center axis X-X' were made equal, so the valve body valve seat As shown in FIG. 3, the valve body 1' and the valve seat 3' do not come into close contact with each other in a full-surface contact state, but come into close contact with each other in a line contact state to stop water.

In general, the amount of bulge caused by water pressure in a cylindrical valve box made of a rigid material such as metal is small;
Elastic deformation of the cylinder can easily occur due to the concentrated load in the direction of the valve axis due to the bearing presser.

This means that the curvature changes easily with little change in the length of the valve body, and the valve body as a cylinder is easily elastically deformed by the rotation of the valve body. When the valve body is rotated to the reference position, that is, the y-y'' position containing the valve shaft orthogonal to the central axis X-X' of the valve body, the valve body can be brought into close contact with the valve seat. The valve box is in contact with the valve seat so as to completely block it, and the water-stopping properties are extremely high.

In summary, the present invention provides a butterfly valve in which the valve body valve seat and the valve body valve seat are made of a rigid material such as metal, with respect to the central axis X-X' axis of the cylindrical valve body to which the valve body is attached. are tilted at different angles θ1 and θ2 in the same direction, and have a diameter D1.
Of the first and second imaginary cylinders each having D2, the valve body valve seat is formed to be the same as the outer periphery of the first imaginary cylinder, and the valve body valve seat is formed to be the same as the outer periphery of the second imaginary cylinder, and 1. y including the valve axis perpendicular to the central axis X-X' axis of the second virtual cylinder
- Since the outer circumferential lengths P□ and P2 on the -y' axis cutting plane are made to be approximately equal, the valve body valve seat and the valve body valve seat are uniquely in close contact with each other through line contact to stop water. Compared to the conventional surface contact case, the surface pressure per unit area of the valve seat is higher even at the same torque, resulting in extremely high water-stopping properties, and it is easier to generate surface pressure near the neck of the valve body. Since it is a line contact, although the surface pressure is high, the torque required to open and close the valve body is small, which has important practical effects.

[Brief explanation of drawings]

FIG. 1 is a side view of a conventional butterfly valve, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a side view showing an embodiment of the butterfly valve according to the present invention. Figure 4 a and b
are sectional views taken along the lines ■-■ and V-V in FIG. 3, respectively, and FIG. 5 is a cross-sectional view of the virtual cylinders E□ and E2 shown in FIG. 3 in a concentric arrangement. The front view, FIG. 6, shows the virtual cylinder E1. shown in FIG. E2 is y including the valve stem
It is a figure which shows the outer peripheral shape on the cut surface cut along the -y' axis. 1... Valve box, 1'... Valve box valve seat, 3.
... Valve body, 3' valve body valve seat, 4... Valve stem,
X-X'... Central axis of the valve box, θ1. θ2...
...First. Second virtual cylinder E□. Inclination angle of E2 with respect to the x-x' axis: 1. Second virtual cylinder E1. Diameter of E2. D□. D2......th

Claims (1)

[Scope of utility model registration request] In a butterfly valve equipped with a valve body valve seat and a valve body valve seat made of a rigid material such as metal, the central axis of the cylindrical valve body
Different angles θ1. in the same direction with respect to X'. As θ2 tilts, the diameter D1. The first one having D2 respectively. In the second virtual cylinder, the valve body valve seat is formed to be the same as the outer periphery of the first virtual cylinder, the valve body valve seat is formed to be the same as the outer periphery of the second virtual cylinder, and the valve body valve seat is formed to be the same as the outer periphery of the second virtual cylinder. A butterfly valve characterized in that the outer circumferential lengths P1 and P2 of the second virtual cylinder in a y-y' axis cutting plane including the valve axis orthogonal to the central axis xx' are substantially equal.