JP2002213622A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a butterfly valve which can grasp small amount of water (fluid) when water flows down, at flooding work time or the like to downstream of a pipeline. SOLUTION: A pair of protrusions 20, 20, provided with a sphere 19 opposed through a small clearance 18 to a valve element seat 2A in the external periphery of a valve element 2 in a small opening region of about 30 degrees, are provided in an inner surface of a valve casing 1, a single through-hole 21 is provided in these protrusions 20, 20. In the case of opening the valve element 2 by a small degree of opening, a small amount of water is made to flow down from the upstream to the downstream side of the valve casing 1 through the through-hole 21. The small amount of water flowing down is grasped by the sum of a passage sectional area of the through-hole 21 in the protrusions 20, 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve and, more particularly, to grasping a flow rate when a small amount of water (fluid) flows down at the time of filling water downstream of a pipe. It relates to a butterfly valve that can be used.

[0002]

2. Description of the Related Art As shown in FIGS. 3 and 4, a butterfly valve comprises a valve box 1, a valve body 2 and a valve rod 3, and a valve rod
Is attached to the valve body 2 and the axis C is orthogonal to the axis C1 of the valve box 1.
The valve body 2 is accommodated in the valve box 1 so as to be rotatable around the axis C2 of the valve rod 3 at the same time as the valve rod 3, and the rotation of the valve body 2 causes the valve sheet 2A of the valve body 2 to be rotated. 1, specifically, it is configured to open and close while being in contact with or separated from the valve box sheet 1A. The inner surface of the valve box 1 has a uniform inner diameter and extends in the axial direction, and its cross-sectional shape is a perfect circle.

[0003] In the butterfly valve configured as described above,
When the valve body 2 is rotated clockwise from the fully closed position shown by the solid line in FIG. 4 to the fully open position shown by the two-dot chain line, the valve seat 1A of the valve box 1 and the valve Body 2
The distance from the rotation locus of the valve sheet 2A is increased, and the cross-sectional area of the fluid flowing down is enlarged, so that the flow rate can be increased. When the valve body 2 is rotated counterclockwise from the fully open position shown by the two-dot chain line to the fully closed position shown by the solid line, the valve body sheet 1A of the valve box 1 and the valve body 2
The distance from the rotation locus of the valve sheet 2A is reduced, and the cross-sectional area of the fluid flowing down is reduced, so that the flow rate can be reduced or made zero. Therefore, from the state of the flow rate 0 where the valve body 2 is positioned at the fully closed position indicated by the solid line of the rotation angle 0 °, the valve body 2 is positioned within the range of the maximum flow rate positioned at the fully open position indicated by the two-dot chain line of the rotation angle 90 ° The flow rate can be adjusted according to the rotation angle.

[0004]

However, in the above-mentioned conventional butterfly valve, the valve body 2 is opened, for example, by an opening .theta. However, even when a small amount of water (fluid) was allowed to flow down while being held at a small opening degree of about 30 degrees, the flow rate could not be grasped.

On the other hand, there is a butterfly valve with a built-in sub-valve shown in FIGS. 5 and 6 as a butterfly valve capable of grasping a flow rate when a small amount of water flows down during a water filling operation or the like. This type of butterfly valve with a built-in sub-valve includes a valve box 1 having an axis C1, a main valve body 2 housed in the valve box 1 so as to be openable and closable, and a sub-valve housed in the main valve body 2 so as to be openable and closable. The main valve body 2 includes an upper valve stem 3 having an axis C2.
A is fixed to the lower valve rod 3B. Upper valve stem 3A is axis C
It is a cylindrical one provided with a through hole 5 in two directions, and is rotatably and airtightly supported around an axis C2 by an upper shaft support 6 of the valve box 1 and protrudes above the upper shaft support 6. The lower valve stem 3B is rotatably and air-tightly supported around the axis C2 by the lower shaft supporting portion 7 of the valve box 1, and is rotated by the rotation of the upper valve stem 3A and the lower valve stem 5 around the axis C2 in the forward and reverse directions. The main valve body 2 opens and closes the valve box 1.

An upper valve rod 8 and a lower valve rod 9 are fixed to the sub-valve element 3, and the upper valve rod 8 is pivoted around an axis C 2 by an upper shaft support 11 of an auxiliary valve box 10 provided on the main valve element 2. The lower valve rod 9 is rotatably and airtightly supported and protrudes above the upper shaft support portion 11, and the lower valve rod 9 is rotatably and airtightly supported around the axis C2 by the lower shaft support portion 12 of the sub-valve box 10. .

A through shaft 5 provided in the upper valve stem 3A in the direction of the axis C2 has a countershaft 1 having an upper end protruding above the upper valve stem 3A.
The lower end 3 of the sub shaft 13 and the upper end of the upper valve rod 8 of the sub valve body 4 are connected to each other via a coupling 14 so as to be able to rotate simultaneously.

A stand 15 is mounted and fastened to the upper shaft support 7 of the valve box 1, and a single shaft drive speed reducer 16 of the stand 15 is mounted and fastened.

According to the above construction, the main valve body 2 and the sub-valve body 4 accommodated in the main valve body 2 are decelerated in the forward and reverse directions by rotating one operating shaft 17, and these are driven. Can be opened and closed. That is, when the operating shaft 17 is rotated in the valve opening direction in a state where the main valve body 2 and the sub-valve element 4 are fully closed, first, the sub-shaft 13 is rotated 90 degrees in the valve-opening direction and the sub-valve body is rotated. 4 is fully opened.

When the operation shaft 17 continues to rotate in the valve opening direction while only the sub-valve 4 is open, the main valve 2 is rotated 45 degrees in the valve opening direction to open the valve to an intermediate opening. I do.
When the rotation of the operation shaft 17 in the valve opening direction is continued from this state, the main valve body 2 is further rotated 45 degrees in the valve opening direction and fully opened.

On the other hand, as described above, when one operating shaft 17 is rotated in the valve closing direction in a state where the main valve body 2 is fully opened, first, after the main valve body 2 is fully closed, Valve body 4
Is fully closed. That is, according to this type of butterfly valve with a built-in auxiliary valve, the opening / closing operation can be performed simply by specifying the rotation direction of one operating shaft 17 without considering the opening / closing operation order of the main valve body 2 and the auxiliary valve body 4. By rotating the main valve element 2 and the sub-valve element 4 based on the order, the main valve element 2 and the sub-valve element 3 can be opened and closed in the specified order.

In addition, when the valve opening operation is performed from a state in which the main valve body 2 and the sub-valve element 4 are fully closed, the sub-valve element 4 is fully opened first. By fully opening the body 4, a small amount of water can flow down,
It is possible to grasp the flow rate of a small amount of water flowing down according to the diameter of the sub-valve box 10, that is, the cross-sectional area of the passage.

However, the butterfly valve with a built-in sub-valve has a number of required parts and a complicated structure, and has a drawback that a single-shaft drive reducer (operating device) 16 is required.

Therefore, the present invention can reduce the number of necessary parts and simplify the structure, and can eliminate the need for a complicated operating device, as compared with a butterfly valve with a built-in sub-valve. An object of the present invention is to provide a butterfly valve capable of grasping a flow rate when a small amount of water (fluid), which has been made impossible by a valve, flows down.

[0015]

In order to achieve the above object, a butterfly valve according to the present invention is provided such that a valve body is mounted on a valve stem having an axis intersecting with an axis of a valve box, and the valve stem is simultaneously mounted on the valve stem. The butterfly valve is housed in the valve box so as to be rotatable about an axis, and the rotation of the valve body causes the outer periphery of the valve body to come into contact with and separate from the valve box sheet on the inner surface of the valve box to open and close the valve box. On the inner surface of the valve box, a projection having a spherical surface opposed to the outer periphery of the valve element via a slidable contact or a gap in the small opening area of the valve element is provided, and this projection is provided from the upstream side to the downstream side of the valve box. It is characterized in that a through hole is provided.

According to the present invention, when the valve is opened at a small opening, a small amount of water flows from the upstream side to the downstream side of the valve box through the through hole provided in the projection. Therefore, it is possible to grasp the flow rate of a small amount of water flowing down according to the passage sectional area of the through hole.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a butterfly valve according to an embodiment of the present invention in an open state, and FIG.
FIG. 4 is a sectional view taken along line AA of FIG. The same or corresponding parts as those in the conventional example shown in FIGS. 3 to 6 are denoted by the same reference numerals, and redundant description will be omitted.

In FIGS. 1 and 2, on the inner surface of the valve box 1, a valve element 2 extends from a fully closed position shown by a solid line in FIG. 2 to a small opening range (opening θ is about 30 degrees) shown by a dashed line. During the valve opening operation and during the valve closing operation from the small opening position indicated by the alternate long and short dash line to the fully closed position indicated by the solid line, a pair of projections each having a spherical surface 19 opposed to the valve seat 2A with a small gap 18 therebetween. The projections 20 are provided with one through hole 21 parallel to the axis C1 of the valve box 1.

With such a configuration, when the valve body 2 is opened from the fully closed position shown by the solid line to the position shown by the dashed line, that is, from the small opening position where the opening .theta.
A small amount of water flows from the upstream side to the downstream side of the valve box 1 through the through hole 21 provided in the valve box 20. For this reason, the passage cross-sectional area of the through hole 21, that is, the protrusion 2 on one side
The flow rate of a small amount of water flowing down can be grasped by the sum of the passage cross-sectional area of the through hole 21 of 0 and the passage cross-sectional area of the through hole 21 of the projection 20 on the other side.

That is, according to the butterfly valve of the present invention, as compared with the butterfly valve with a built-in sub-valve described with reference to FIGS. 5 and 6, the number of required parts is reduced, the structure is simplified, and the operating device is simplified. In addition to making it unnecessary, it is possible to grasp the flow rate when a small amount of water flows down, which has been impossible with the conventional butterfly valve described with reference to FIGS.

In the above-described embodiment, the pair of protrusions is formed in the valve body sheet 2A through the small gap 18 during the valve opening operation and the valve closing operation of the valve body 2 in the small opening degree range where the opening degree θ is about 30 degrees. Although the description has been made of the configuration in which the spherical surfaces 19 of 20 and 20 face each other, the pair of projections 20 and 20 are formed on the valve element sheet 2A during the valve opening operation and the valve closing operation of the valve element 2 in the small opening degree range.
May be configured so that the spherical surface 19 of the sliding contact. Further, although one through hole 21 is provided in each of the pair of protrusions 20, 20, two or more through holes 21 may be provided in each of the pair of protrusions 20, 20.

[0022]

As described above, since the butterfly valve according to the present invention is constituted, the following special effects can be obtained.

That is, a projection having a spherical surface opposed to the valve body sheet through a small gap in a small opening area of the valve body is provided on the inner surface of the valve box. When the valve body is opened at a small opening by providing a through hole toward the side, a small amount of water flows down from the upstream side to the downstream side of the valve box through the through hole provided in the projection. Therefore, it is possible to grasp the flow rate of a small amount of water flowing down according to the passage sectional area of the through hole. In other words, compared to a butterfly valve with a built-in auxiliary valve, the number of required parts can be reduced, the structure can be simplified, a complicated operating device can be eliminated, and the conventional butterfly valve cannot be used. It is possible to grasp the flow rate when a small amount of water flows down.

[Brief description of the drawings]

FIG. 1 is a front view of a butterfly valve according to an embodiment of the present invention in a valve open state.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a schematic front view showing an example of a conventional butterfly valve.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a schematic front view showing an example of a butterfly valve with a built-in auxiliary valve.

FIG. 6 is a side view of FIG. 5, with a partial cross section.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 valve box 1A valve box sheet 2 valve element 2A valve element sheet (outer periphery of valve element) 3 valve rod 18 gap 19 spherical surface 20 protrusion 21 through hole C1 axis of valve box C2 axis of valve rod

Claims (1)

[Claims] A valve body is mounted on a valve stem having an axis intersecting the axis of a valve box, and is housed in the valve box so as to be rotatable about the axis at the same time as the valve stem. The outer periphery of the butterfly valve is configured to open and close the valve box by contacting and separating the valve box sheet on the inner surface of the valve box. A butterfly valve provided with a projection having a spherical surface facing through a sliding contact or a gap, and having a through-hole extending from the upstream side to the downstream side of the valve box.