JP2568206Y2 - Anti-chattering device for dual plate check valve - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a dual plate (two-valve plate) comprising two semi-circular valve plates which are rotatably supported by a shaft on a main body and urged in a valve closing direction by a spring force. The check valve is used for a wide range of applications from 50 to 1000 mm in diameter.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, the above-mentioned dual plate check valve has two semicircular valves rotatably supported by a shaft (shaft) 2 on a main body (valve main body) 1. The plates (plates) 3 and 4 are wound around the shaft 2 and the coil springs 5 in which both ends 5a, 5a abut against the inner surfaces of the two valve plates, respectively, are used to close the valve (two plates). (The valve plate itself is opened). In the drawing, reference numeral 6 denotes a stop pin provided at a position sandwiched between the back surfaces of the two semicircular valve plates 3 and 4 when the valve is opened, and 7 denotes a pipe.

[0003] With the above construction, the piping 7
When the fluid does not flow through the inside, the two semi-circular valve plates 3 and 4 are spread 180 ° by the expanding force of the coil spring 5 to completely close the pipeline.

Then, when a fluid flows in the pipe 7 in the direction of arrow A, the two semi-circular valve plates 3 and 4 resist the force of the coil spring 5 by the fluid pressure, as shown in the drawing. The pipe is opened, and at a predetermined flow rate, both valve plates 3 and 4 are closed and kept fully open until they come into contact with the stop pin 6 at the center.

[0005] When the water supply in the pipe 7 is suddenly cut off due to an emergency stop of the pump or the like, the two valve plates 3 and 4 are quickly and reliably operated (closed) by the spring force, and the backflow shock wave (water hammer) is provided. ) To protect the piping system, and constitutes a check valve that is compact, lightweight, durable and has excellent corrosion resistance.

[0006]

In the conventional dual plate check valve described above, when the check valve is installed near the pump outlet or immediately after the control valve in order to make piping design and equipment compact, The swirling flow or turbulent flow flows into the check valve, and the two semicircular valve plates 3 and 4 supported by the common shaft 2 and urged by the coil spring 5 cause the swirling flow and turbulent flow to cause the arrow B to flow. As shown in FIGS. 3 and 4, there is a problem in that the spring 5 becomes unstable and chattering (flapping) occurs, and the spring 5 is damaged and the shaft 2 is worn.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dual-plate check valve in which chattering does not occur between two semicircular valve plates under the above-mentioned use conditions.

[0008]

In order to achieve the above object, the present invention provides two semi-circular valve plates which are rotatably supported by a main body and urged by a spring force in a valve closing direction. In the dual plate check valve consisting of, when fully opened, at the position sandwiched between the back surfaces of both semicircular valve plates, stoppers are installed so as to be in contact with the back surfaces of both valve plates, respectively. On the back side of the valve plate, an inlet and an outlet are connected to the upstream and downstream sides of the main fluid flowing inside the main body, respectively, and a passage that reduces the passage cross-sectional area of the intermediate portion and increases the flow velocity of the portion is provided. When the valve is fully opened, a pressure difference is generated between the static pressure of the fluid flowing through the passage and the static pressure of the main fluid flowing inside the main body, and the back surfaces of both valve plates are drawn toward the stopper surface. I have.

[0009]

Since the present invention is constructed as described above, when the check valve is fully opened, the two semi-circular valve plates open the conduit against the spring force, and the back surfaces of both valve plates are closed. In the passage formed on the front surface of the stopper or the back surface of the valve plate, a part of the upstream main fluid flowing inside the main body is taken in from the inlet portion, and a reduced portion that comes into contact with the back surface of the valve plate in the middle portion is provided in the passage formed on the stopper surface or the valve plate back surface. Then, a flow that flows out of the outlet portion to the downstream side of the main fluid again occurs, and in the above-described reduced portion of the flow, the flow velocity increases, the static pressure decreases, and a pressure difference occurs between the static pressure and the main fluid. As a result, both valve plates are drawn to the stopper, and the stopper prevents the fluid from flowing to the back surfaces of both valve plates.

In this way, it is possible to prevent a chattering phenomenon that is likely to be caused by a swirling flow or a turbulent flow flowing into the check valve when the valve is fully opened.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a dual plate check valve according to an embodiment of the present invention, which is orthogonal to a shaft supporting a valve plate. In FIG. 1, the same reference numerals as those shown in FIG. Shall be shown.

In the drawing, two semicircular valve plates 3 and 4 rotatably supported by a main body 1 by a shaft 2 are wound around the shaft 2 and both ends 5a, 5a are formed by the two plates. There is no difference from the conventional example (FIG. 2) in that the coil springs 5 abut against the inner surfaces of the valve plates 3 and 4 in the valve closing direction.

In this embodiment (the present invention), when fully opened, stoppers 11 are provided at positions sandwiched between the back surfaces of the two semicircular valve plates 3 and 4 so as to be in contact with the back surfaces of the two valve plates. . The front surface of the stopper 11 is in contact with the back surfaces of the valve plates 3 and 4 and the inlet and outlet portions are respectively connected to the upstream and downstream sides of the main fluid flowing inside the main body 1 to reduce the cross-sectional area of the passage of the intermediate portion. A groove-like passage 12 is formed so as to slightly increase the flow velocity in the portion.

When the valve plates 3 and 4 are fully opened, the upstream main fluid is introduced into the passage 12 through an intake port 12a formed on the upstream side of each valve plate base through which the shaft 5 passes. The passage 12 flows in the direction indicated by the arrow D and flows downstream from the outlet end 12b.

[0015] With the above configuration, the piping 7
When the fluid is not flowing through the inside, the two semicircular valve plates 3 and 4 are spread 180 ° by the expanding force of the coil spring 5 to completely close the pipeline. When the main fluid is fully closed, the main fluid intake port 12a is in a closed state, so that no fluid flows into the passage 12.

Next, when the fluid is flowing smoothly in the direction of the arrow A in the pipe 7, the two valve plates 3 and 4 are pressed against the spring force of the coil spring 5 by the fluid pressure. Thus, at a predetermined flow rate, the valve plates 3 and 4 are closed until they come into contact with the stopper 11 to keep the pipe line fully open.

At this time, a part of the upstream main fluid flowing through the inside of the main body 1 is taken into the passage 12 formed on the surface of the stopper 11 through the intake port 12a, and the back surface of the valve plates 3 and 4 at the intermediate portion is taken into the passage 12a. A flow that flows out of the outlet end portion 12b to the downstream side of the main fluid again through the contacting reduced portion occurs. In the reduced portion of the flow, the flow velocity increases, the static pressure decreases, and the static pressure of the main fluid decreases. Since a pressure difference is generated between the pressure and the pressure, an action of drawing the back surfaces of the valve plates 3 and 4 toward the surface of the stopper 11 is generated. Also, a stopper 1 is provided on the back surface of the valve plates 4 and 5.
1 is installed so as to be pinched when fully opened, the flow in the pipe is not smooth, and even when the swirling flow or turbulent flow is flowing into the check valve, the stopper 11 makes the two valve plates 3 and 4 open. Of the valve plates are prevented from wrapping around to the back surfaces, and the back surfaces of both valve plates are attracted to the stopper 11 by a pressure difference, so that chattering does not occur in the valve plates 3 and 4.

Accordingly, both valve plates are stable in the fully opened state, abnormal noise generated when metal strikes is prevented, durability of the spring is improved, and damage to parts such as the shaft 2 and the spring 5 is prevented. .

In the above-described embodiment, the reduced portion of the cross-sectional area of the passage 12 formed on the surface of the stopper 11 reduces the circumferential width of the passage or the radial depth. It is formed by doing. The passage 12
May be provided on the back side of the valve plates 3 and 4 where the stopper 11 and the valve plates 3 and 4 are in contact with each other.

[0020]

[Effects of the Invention] As described above, according to the present invention,
A dual-plate check valve comprising two semi-circular valve plates rotatably supported by a main body and urged in a valve closing direction by a spring force. The stoppers are installed so as to be in contact with the back surfaces of the two valve plates, respectively, and the inlet and outlet are located on the surface of the stoppers that are in contact with each other or the back surface of the valve plate, with the upstream side of the main fluid flowing inside the main body. Each passage is connected to the downstream side to form a passage that reduces the cross-sectional area of the passage at the intermediate portion and increases the flow velocity of the passage, and when fully opened, the static pressure of the fluid flowing through the passage and the main fluid flowing inside the main body. By creating a pressure difference between the valve and the static pressure and drawing both valve plate back surfaces toward the stopper surface, the stopper not only prevents the fluid from flowing to the valve plate back surface when the valve body is fully opened. , Back of valve plate formed on stopper surface Due to the suction action based on the static pressure drop in the passage in contact with the valve, the back surface of the valve plate is drawn to the stopper, so that even when the flow of fluid in the pipe is not smooth and a swirl flow or turbulent flow is flowing into the check valve, No chattering phenomenon occurs.

Therefore, the valve plate is stable in the fully opened state, not only preventing abnormal noise generated when metal is hit, but also improving the durability of the spring and improving the parts such as the shaft supporting the spring and the valve plate. Damage is prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a dual plate check valve according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 axis 3, 4 Semicircular valve plate 5 Coil spring 11 Stopper 12 Passage

Claims (1)

(57) [Scope of request for utility model registration] 1. A dual plate check valve comprising two semicircular valve plates rotatably supported by a main body and urged in a valve closing direction by a spring force. At the position sandwiched between the backs of the plates, stoppers are installed so as to be in contact with the backs of the two valve plates, and the inlet and outlet flow through the main body inside the surface of these stoppers or the back of the valve plate. It communicates with the upstream and downstream sides of the body, respectively.
A passage is formed to reduce the cross-sectional area of the passage at the intermediate portion to increase the flow velocity of the passage. When the passage is fully opened, the pressure between the static pressure of the fluid flowing through the passage and the static pressure of the main fluid flowing inside the main body is increased. A chattering preventing device for a dual plate check valve, wherein a difference is generated so that the back surfaces of both valve plates are drawn toward a stopper surface.