JPH09269076A - Swinging check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the increase of the amplitude of a valve element, and prevent occurrence of a noise by arranging in a valve box, a regulating member by which the valve opening angle of the valve element is regulated at a predetermined angle. SOLUTION: A valve element 14 is pushed up from a valve seat 13 by the flow of a fluid forward direction so as to be opened, and pushed to the valve seat 13 by the flow of a fluid reverse direction 5o as to be closed. Hereat, if the valve element 14 receives external disturbance and starts its vibration by fluid flow change and so on, the valve element 14 absorbs energy from fluid flow so as to increase its amplitude, however it is brought in contact with a screw member 20, thereby its amplitude may not be increased any more, and its vibration is damped, thus occurrence of a noise can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing type check valve.

[0002]

2. Description of the Related Art As is well known, a check valve is used to prevent a backflow by allowing a fluid to flow to one side in various pipes. A swing-type check valve, which is one type of check valve, has a valve box in which a fluid flow path is formed, and a swingable shaft support with one end (usually the upper end) inside the valve box. And a valve body that is formed. In this swing type check valve, the valve body is opened by being pushed up by the forward flow of fluid, and the valve body is pressed against the valve seat by the reverse flow of fluid to prevent the reverse flow.

The swing-type check valve is suitable for a pipe through which gas flows because it has a small pressure loss.
Used for vacuum system piping of vacuum cooling device. As is well known, a vacuum cooling device stores an object to be cooled in a cooling tank, and suctions and evacuates this cooling tank with a vacuum pump to reduce the pressure, thereby lowering the saturated vapor temperature in the cooling tank to cool the object to be cooled. By evaporating the water inside, the latent heat of vaporization at that time is used to cool the object to be cooled. In the vacuum system piping of such a vacuum cooling device, the check valve prevents the air and steam evacuated by the vacuum pump from flowing back into the cooling tank. The backflow of the working fluid is prevented. As the vacuum pump, a water-sealed vacuum pump or a water ejector is generally used, and water is supplied as a working fluid. is there.

If a swing type check valve is used in such a vacuum piping system, a problem may occur in that the valve element vibrates and noise continues to occur. That is, as described above, since the valve body of the swing check valve is structurally a single pendulum as described above, when the valve body starts to vibrate, it is easy to perform unless the damping force acts. The situation will not stop.
When this swing check valve is used for liquids such as water, the liquid itself acts as a damping element,
Such vibration is rarely continued. But,
When the swing type check valve is used for a liquid such as water against the flow of gas (air or steam) as described above, the force by which the gas suppresses the vibration of the valve body is very weak. When the valve element starts to vibrate due to some disturbance, it initially vibrates at a state close to the natural frequency, but absorbs energy from the flow and increases its amplitude, and finally this valve element collides with the valve seat. Like It is under such conditions that the above-mentioned noise problem occurs, and after the valve body collides with the valve seat, it is lifted by the repulsive force, and during the process, energy is also received from the flow for about several hertz. Vibration with noise is repeated (so-called chattering phenomenon).

[0005]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide a swing type check valve which prevents the generation of noise.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a valve box having a fluid passage formed therein and a valve seat pivotally supported in the valve box and formed in the valve box. A regulating member for regulating the valve opening angle of the valve element to a predetermined angle in the valve box, the valve element opening by the forward flow of the fluid and closing by the reverse flow of the fluid. The above configuration solves the above-mentioned problems.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is applied to a swing type check valve, and is particularly suitable for a swing type check valve used in a pipe through which gas flows. According to the present invention, a regulating member for regulating the valve opening angle of the valve element to a predetermined angle is provided in the valve box. That is, a swing check valve has a valve seat formed in a valve box that forms a fluid flow path, and a valve body (usually the upper end side) whose one end is axially supported is housed in this valve box. The valve body comes into contact with the valve seat to block the flow path. This valve body swings around an axis by the flow of fluid, and the valve body is pushed up from the valve seat by the forward flow of the fluid to open the valve, and the valve body is rotated by the reverse flow of the fluid. It is pressed against and closes the valve. The swing check valve according to the present invention prevents vibration and noise of the valve body by regulating the valve opening angle of the valve body. That is, according to the present invention, the valve body that has started to vibrate due to disturbance absorbs energy from the flow and increases its amplitude. Since the pressure is suppressed and the vibration is attenuated, the generation of noise can be prevented. Here, the valve opening angle of the valve body is the angle at which the valve body is pushed up from the valve seat by the fluid flowing in the forward direction and at that time. The predetermined angle regulated by the regulation member is set to be an angle slightly larger than the angle at which the valve body is pushed up when the fluid is flowing in a normal state. That is, as described above, the valve element that has started to vibrate does not increase its amplitude but regulates it to an angle at which it can be attenuated. The regulation member regulates the swing angle by the abutment of the valve body inside the valve box. Even if the regulation member is provided integrally with the valve box, it is a separate member. It may be configured with.

Further, with respect to the regulating member, by providing a cushioning member at a portion in contact with the valve body, an impact sound due to a collision with the valve body is reduced, and an increase in amplitude due to rebound of the valve body is prevented. be able to. This cushioning member
Like rubber (natural rubber, synthetic rubber), synthetic resin, etc., it has appropriate elasticity and shock absorbing function. The cushioning member is provided at a portion of the regulating member that comes into contact with the valve body, but this means that at least this portion is sufficient, and the entire regulating member is
It also includes a cushioning member.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the swing type check valve according to the present invention will be described in detail below with reference to FIG. 1 is a drawing for explaining the vertical cross-sectional shape of an embodiment of the swing type check valve according to the present invention. In FIG.
The swing check valve 10 includes a valve box 11 having a fluid passage 12 formed therein. In this embodiment, the flow path 12 for the fluid is defined as the flow from the left side to the right side in FIG. 1 as the forward flow of the fluid and the flow from the right side to the left side in FIG. 1 as the reverse flow of the fluid. is there. In the valve box 11, a partition wall 15 that crosses the fluid flow passage 12 is formed at a position upstream of the flow passage 12 in the forward direction (a position on the left side in FIG. 1). And this partition wall 15
By forming an opening in a part of the, the flow path 12 is communicated. Further, a valve seat 13 is formed on the surface of the partition wall 15 on the downstream side of the forward flow of the fluid. Therefore, in the swing check valve 10, the valve body 14 is pushed up from the valve seat 13 by the forward flow of the fluid to open the valve, and the valve body 14 is pressed against the valve seat 13 by the reverse flow of the fluid. To close the valve. A support shaft 16 is arranged above the valve seat 13, and the support shaft 16 supports the valve element 14 so as to be swingable. Here, the valve seat 13 has a surface on the side of the support shaft 16 slightly inclined to a surface on the downstream side of the forward flow of the fluid so that the valve seat 14 comes into contact with the valve seat 13 by its own weight. Configured.

Further, the valve body 14 is provided in the valve box 11.
A screw member 20 is provided as a restricting member that restricts the valve opening angle. In the illustrated embodiment, the screw member 20 has a screw hole 17 formed in the valve box 11 on the side where the valve body 14 is opened, and the screw hole 17 is utilized to make the valve box 1
The screw member 20 is attached by screwing the screw member 20 into the inside from the bottom outer side. The valve opening angle of the valve body 14 regulated by the screw member 20 is set to be slightly larger than the angle at which the valve body 14 is pushed up when the fluid flows in a normal state. That is, as described above, the valve body 14 that started to vibrate does not increase its amplitude but is set to an angle at which it attenuates. Further, at the portion of the screw member 20 projecting into the valve box 11, the cushioning member 2 is provided at the contact portion with the valve body 14.
1 is provided. In the illustrated embodiment, the cushioning member 21 covers most of the screw portion exposed inside the valve box 11, and its material is rubber (natural rubber, synthetic rubber), synthetic resin, or the like. And a shock absorbing function, for example, a tube made of vinyl or the like is covered or a tape is wrapped around the tube.

In the swing check valve 10 having the above structure, the valve body 14 is pushed up from the valve seat 13 by the forward flow of the fluid to open the valve, and the valve body 14 is opened by the reverse flow of the fluid. It is pressed against the valve seat 13 to close the valve. If the valve body 14 starts to vibrate due to disturbance due to changes in the flow rate of the fluid, the valve body 14 absorbs energy from the flow of the fluid and increases its amplitude. By touching 20, there is no more increase in the amplitude and the vibration is attenuated, so that the generation of noise can be prevented. Further, since the screw member 20 is provided with the shock absorbing member 21, when the valve body 14 collides with the shock absorbing member 21, the shock absorbing member 21 absorbs the shock, thereby suppressing generation of shock noise at this time. Further, since it is possible to prevent the increase in the amplitude due to the rebound of the valve body 14 after the collision, the vibration of the valve body 14 is suppressed. Moreover, since the present invention can be applied to an existing swing type check valve by a simple operation, it is possible to easily prevent generation of noise.

In the above description, the screw member 20 is used as the regulating member, and the valve body 1 is provided inside the valve box 11.
The contact angle with 4 regulates the swing angle.
This regulating member may be provided integrally with the valve box 11 or may be a separate member.

Next, the swing type check valve 1 according to the present invention.
FIG. 2 shows the case where 0 is applied to the aforementioned vacuum cooling device.
This will be described with reference to FIG. 2 is a diagram for explaining an example of use of the swing check valve. In FIG. 2, the vacuum cooling device includes a cooling tank 1 for containing an object to be cooled,
A vacuum system pipe 2 and an outside air introduction pipe 3 connected to this cooling tank are provided. A vacuum pump 4 is connected to the vacuum system pipe 2, and the check valve 10 is connected between the vacuum pump 4 and the cooling tank 1. A filter 5 is connected to the upstream end of the outside air introducing pipe 3, and an outside air introducing valve 6 is connected between the filter 5 and the cooling tank 1. The outside air introducing pipe 3 is for returning the inside of the cooling tank 1 to the atmospheric pressure and taking out the object to be cooled after the completion of the vacuum cooling. Here, when the lifting angle of the valve element 14 in the swing check valve 10 is about 30 degrees during steady operation of the vacuum cooling device, the valve opening angle of the valve element 14 regulated by the regulation member 20 is: It is assumed that the valve body 14 swings slightly larger than during steady operation (for example, about 40 degrees). In such a vacuum cooling device, at the time of vacuum exhaust, the vacuum pump 4 is started, the air in the cooling tank 1 is removed by the vacuum system pipe 2, and the vapor evaporated from the object to be cooled accompanying this is exhausted. . At this time, these air and steam pass through the check valve 10. Here, in the case of the conventional check valve, when the valve body 14 starts to vibrate due to some disturbance, it vibrates in a state close to the natural frequency at first, absorbs energy from the flow, and increases its amplitude. Finally, it collides with the valve seat and produces noise. But,
According to the swing check valve 10 of the present invention, the valve body 1
Even if 4 starts to vibrate due to disturbance and further increases its amplitude, the collision with the screw member 20 will not increase the amplitude any more, and the vibration will be attenuated, thus preventing the generation of noise. it can. Moreover, the shock absorbing member 21 provided on the screw member 20 absorbs the shock caused by the collision between the screw member 20 and the valve body 14, so that the shock noise at this time is suppressed and the valve body 14 after the collision is further suppressed. Since it is possible to prevent an increase in the amplitude due to the rebound of B, the vibration of the valve body 14 is suppressed.

[0014]

As described above, according to the swing type check valve of the present invention, even if the valve body which has been disturbed starts to vibrate and absorbs energy from the flow to increase its amplitude, Since the increase of the amplitude is suppressed by the restriction member, the generation of noise can be prevented. Furthermore, by providing a shock-absorbing member at the contact portion of the regulating member with the valve body, it is possible to reduce the impact noise due to the collision with the valve body and prevent the increase in the amplitude due to the rebound of the valve body. Further, according to the present invention, it is possible to prevent noise from being generated even with an existing swing check valve by a simple operation.

[Brief description of drawings]

FIG. 1 is a drawing for explaining a vertical cross-sectional shape of an embodiment of a swing type check valve according to the present invention.

FIG. 2 is a diagram for explaining an example of use of a swing check valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Swing-type check valve 11 Valve box 12 Flow path 13 Valve seat 14 Valve body 17 Screw hole 20 Screw member (regulating member) 21 Buffer member

Claims (2)

[Claims] 1. A valve box 11 having a fluid passage 12 formed therein, and a valve seat 13 pivotably supported in the valve box 11 and formed in the valve box 11 A valve body 14 which is opened by a flow in the forward direction and closed by a flow in the reverse direction of the fluid.
A swing-type check valve, which is provided with a regulating member 20 for regulating the valve opening angle of the valve to a predetermined angle. 2. The swing-type check valve according to claim 1, wherein the regulating member 20 includes a cushioning member 21 at a portion in contact with the valve body 14.