JPH034085A - Butterfly valve - Google Patents

Abstract

PURPOSE:To suppress the generation of cavitation with a flow speed of fluid decreased by providing a valve unit side fluid control piece in a valve unit and a valve case side fluid control piece in a valve case, in the case of a butterfly valve in which the valve unit is turnably provided through a valve shaft in the valve case. CONSTITUTION:In a butterfly valve 1, a valve unit 3, formed in a disk unit, is supported by a central valve shaft 4 and turnably arranged in a cylindrical valve case 2. A seal member 5 is peripherally provided in the valve case. A valve unit side fluid control piece 6, in which a flow path for guide-dividing a flow of fluid is formed in the peripheral edge part of a surface in an opposite side to a direction of valve open action of the valve unit 3, is provided in the valve unit 3, and a valve case side fluid control piece 7, in which a flow path connected to the flow path of the valve unit 3 is formed in the side of a direction of valve unit open action in the internal periphery of the valve case 2, is provided in the valve case 2. As a result, a pressure is smoothly decreased, and the generation of cavitation can be suppressed with noise and vibration reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a butterfly valve that has an enhanced effect of suppressing cavitation occurring on the secondary side of a valve body.

[Conventional technology]

Conventionally, during throttling operation (small opening degree) of a butterfly valve, cavitation occurs on the secondary side (downstream side) of the valve body, and there is a risk of damaging the valve body.
As shown in the publication, comb-like protrusions are provided on the periphery of the valve body to divide and guide the flow of fluid, converting the fluid into a fine jet flow through the slits between the protrusions, and distributing the fluid on the downstream side of the valve body. In addition to dispersing the cavitation that occurs in the air, the growth of cavitation is suppressed as much as possible.

[Problem to be solved by the invention]

However, even with the butterfly valve having the above-described structure, the effect of suppressing cavitation is not necessarily sufficient, and there has been a desire to develop a butterfly valve with further excellent cavitation resistance characteristics.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a butterfly valve that enhances the effect of suppressing cavitation, allows good throttling operation, and achieves low noise and vibration.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a butterfly valve in which a valve body is rotatably provided in a valve body via a valve shaft, in which the valve body is rotated in a direction opposite to the valve opening operation direction. A valve body side fluid control piece is provided on the peripheral edge of the side surface, the valve body side fluid control piece having a flow path for dividing and guiding the fluid flow, and on the valve body side of the inner periphery of the valve box in the valve opening operation direction,
The present invention is characterized in that a valve box-side fluid control piece is provided that forms a flow path that is continuous with the flow path of the valve body when the valve body is opened.

[For production]

With this configuration, the fluid flow is divided and guided and flows through the continuous valve body side flow path and the valve box side flow path, so the flow velocity of the fluid is reduced and the occurrence of cavitation can be suppressed.

[Example〕 Embodiments of the present invention will be described below based on the drawings.

1 to 5 show a first embodiment of the present invention,
The butterfly valve 1 has a disk shaped like a convex lens in cross section inside a cylindrical valve box 2 which is interposed in a conduit (not shown) with the left side facing upstream in FIGS. 1, 3 and 4. A valve body 3 formed in the body is rotatably supported by a valve shaft 4 passing through the center thereof.

Further, a sealing member 5 is disposed around the inside of the valve body 2, and a sealing portion 3a on the periphery of the valve body 3 is seated on the sealing member 5 to block the flow of fluid. is the first
The valve is opened by rotating clockwise in FIGS. 3 and 4.

The valve body 3 has a surface opposite to the valve opening operation direction, that is, FIG.
In FIGS. 3 and 4, with the valve stem 4 as the center, the valve body side fluid is placed at the periphery of the left side surface on the upper side, which is the upstream side, and on the periphery of the right side surface, which is the downstream side, on the lower side. A control piece 6 is provided.

The valve body side fluid control piece 6 has a comb-teeth shape having a plurality of teeth 6a formed long in the direction of fluid flow,
The slit 6b between the adjacent teeth 6g and 6a is used as a flow path that divides and guides the flow of fluid.

The valve body side fluid control piece 6 may be formed separately from the valve body 3 and attached to the valve body 3, or may be formed integrally with the valve body 3.

In addition, inside the valve box 2, the valve body 3 is located on the side where the valve is opened, that is, in FIGS. On the upstream side, a valve box side fluid 11111 piece 7 is provided, respectively.

The valve box side fluid control piece 7 has a comb-teeth shape with a plurality of m 7 a formed long in the fluid flow direction, and divides and guides the fluid flow through the slit 7b between adjacent @7a, 7a. The slit 7b is
When the valve body 3 is in the open state, as shown in FIG. 5, it is formed so as to be continuous with the slit 6b of the valve body side fluid control piece 6 of the valve body 3.

The valve body side fluid control piece 6 and the valve body side fluid control piece 7 are arranged so that the teeth 6a and 7g of both slide when the valve body 3 is opened, and the valve body 3 is rotated by 90 degrees. Even in the fully open state, the slit 6b and the slit 7b are formed to be continuous.

Further, the valve box side fluid control piece 7 may also be formed separately from the valve box 2 and attached to the valve M2, or may be formed integrally with the valve box 2.

With this configuration, when the valve body 3 is opened,
The fluid flows through continuous slits 6b in the valve body side fluid control piece 6 and the valve body side fluid control piece 7.

7b and is guided in sections.

At this time, the pressure of the fluid decreases smoothly due to the resistance of the slits 6b and 7b, and especially during throttling operation where cavitation is likely to occur, the slits 6b and 7b move in the direction of fluid flow, as shown in Figure 3. Since it continues for a long time, the flow velocity of the fluid is further reduced, the occurrence of cavitation is suppressed, and noise and vibration can be reduced.

In addition, if a foreign object or the like gets caught in the valve body side fluid control piece 6, by rotating the valve body 3 by 90 degrees or more, the flow of fluid to the valve body side fluid control piece 6 will be reversed. can be easily removed.

6 and 7 show a second embodiment of the present invention,
A plurality of through holes IC1a are formed in the valve body side fluid control piece 10 provided in the valve body 3 to form a flow path for dividing and guiding the fluid, while a valve body provided inside the valve body 2 Also in the side fluid control piece 11, a plurality of long through holes 11a extending in the fluid flow direction are formed as channels for dividing and guiding the fluid.

The through hole 10a and the through hole 11a are formed so as to be continuous when the valve body 3 is opened, so that the fluid flows through the through hole 10a.
The flow rate decreases while flowing through a and lla, suppressing the occurrence of cavities and cheeks, as in the previous embodiment.

〔Effect of the invention〕

As described above, the present invention includes a valve body-side fluid control piece in which a flow path for dividing and guiding the flow of fluid is formed on the peripheral edge of the face of the valve body opposite to the valve opening operation direction of the butterfly valve. At the same time, a valve body-side fluid control piece is provided on the inner circumference of the valve body on the side of the valve body in the valve opening operation direction. When the valve body is opened, the fluid flowing inside the valve box is divided and guided, and the pressure decreases smoothly as it flows through the valve body side flow path and the valve body side flow path continuous to this, thereby preventing the occurrence of cavitation. This allows for good throttling operation, as well as low noise and vibration.

[Brief explanation of drawings]

1 to 5 show a first embodiment of the present invention,
Fig. 1 is a cross-sectional front view of the butterfly valve, Fig. 2 is a side view, Fig. 3 is a cross-sectional front view with the valve body slightly open, and Fig. 4 is a cross-sectional front view with the valve body fully open. Figure 5 is also a side view with the valve body fully open, No. 61! ! ! 7F and 7 show a second embodiment of the present invention, FIG. 6 is a cross-sectional front view of the butterfly valve, and FIG. 7 is a side view of the butterfly valve. 1... Butterfly valve 2... Valve box 3... Valve body 4... Valve shaft 6610... Valve body side fluid control piece 6a... Teeth 6b... Slit 7.11.
...Valve box side fluid 31411 piece 7a...teeth
7b...slib) 10a,
1 1m-... through hole) 1 factor 1 butterfly valve

Claims (1)

[Claims] 1. In a butterfly valve in which a valve body is rotatably provided in a valve body via a valve shaft, a flow that divides and guides the flow of fluid is provided at the peripheral edge of the face of the valve body opposite to the valve opening operation direction. A valve is provided with a fluid control piece on the valve body side in which a passage is formed, and a flow passage is formed on the inner periphery of the valve body on the valve opening operation direction side of the valve body, which is continuous with the flow passage of the valve body when the valve body is opened. A butterfly valve characterized by having a box-side fluid control piece.