JPS5813177Y2 - non-return valve - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a versatile check valve for use in membrane fluid pipelines.

It has been known for a long time that when a backflow occurs in a fluid pipeline and the check valve is suddenly closed due to the backflow, a water hammer phenomenon occurs in the pipeline.

In order to prevent this, various structures such as those with a dashpot installed inside the valve box or in the pipeline have been considered. There is a type of check valve (in which the valve rotates) in which a buffer chamber is formed around the valve opening when the valve body is closed (see Japanese Utility Model Publication No. 158930/1983).

As shown in FIG.
An annular groove 21 is provided around 0, and a protrusion 23 provided integrally with the valve body 22 is fitted into the groove 21 as the valve body 22 is closed, and a buffer chamber is formed by the groove 21 and the protrusion 23. This is how it was done.

However, the above-mentioned valve has a problem in that it hardly exerts the necessary buffering effect when the valve body is closed due to back pressure.

That is, the valve body of the above-mentioned check valve is a swing type that is directly supported by the valve shaft, and the protrusion that is to be fitted into the annular groove is provided on the valve body, so that the valve body closes. Accordingly, the protrusion of the valve body starts to fit from a part of the annular groove,
From that position, it is sequentially inserted in the direction of both sides of the circumference of the annular groove.

Therefore, the fluid in the groove is freely discharged from the unfitted portion without resistance when the protrusion is fitted, and is not sealed in a certain chamber.

Therefore, it is not possible to generate a force to counter sudden occlusion of the valve body.

In the above check valve, if the inclination of the valve body is changed so that its protrusions fit into the entire annular groove at the same time, the valve body will completely block the valve port at once, resulting in a water hammer phenomenon. There is a risk.

Therefore, the technical problem of this invention is to prevent the buffer fluid from being discharged without resistance and to enable the buffering action to correspond appropriately to the downstream fluid pressure.

The technical measures taken to solve the above technical problems are as follows.

That is, a groove is provided in the valve body part around the valve port, an annular member is fitted into the groove to form a buffer chamber, a bolt is inserted into the annular member while keeping it watertight, and one end of this bolt is inserted into the valve body. The annular member is fixed to the buffer chamber, and the annular member is biased in the direction of pushing out by an elastic body provided in the buffer chamber, and the annular member has a passage connecting the buffer chamber and the valve chamber, and the outside of the portion protruding from the buffer chamber when the valve is open. An auxiliary valve port that communicates with the side surface and the inner surface is provided, a flow rate control passage that communicates with the groove upstream of the valve port, and a flow rate control valve that can adjust the flow rate of the passage from outside the valve box, and a flow rate control valve that abuts the annular member and controls the flow rate of the passage. A valve body that closes the passage is provided in the valve chamber,
In addition, a valve seat is provided on the outer periphery of the groove to which the valve body is pressed.

The effects of the above technical means are as follows.

That is, when the valve body moves in the closing direction due to backflow pressure and comes into contact with the annular member, the valve body closes the passage provided in the annular member,
Prevent fluid from exiting the passageway.

Further, at the same time as the passage is closed, the valve body closes most of the valve port.

In this state, the downstream side and the upstream side communicate with each other through the auxiliary valve port and are not completely shut off.

Subsequently, the annular member is pushed into the annular groove by the counter pressure acting on the valve body, and the auxiliary valve port is closed by the inner circumferential wall of the groove.

At this time, the fluid in the buffer chamber is discharged according to the amount adjusted by the external flow rate control valve, so the auxiliary valve port is closed at a corresponding speed.

Therefore, since the fluid in the buffer chamber is not pushed out without resistance, the downstream side and the upstream side are completely shut off without causing a water hammer phenomenon.

Further, the buffer chamber is configured by fitting an annular member into an annular groove,
Since the passage of the annular member is closed by the valve body, there is no problem that the fluid in the buffer chamber is discharged without resistance.

This invention produces the following unique effects.

In other words, since the flow rate adjustment passage communicates the inside of the buffer chamber with the upstream side of the valve opening, the inside of the buffer chamber does not become under negative pressure when the valve body is opened.
Therefore, the responsiveness of the valve body during the valve opening operation is good.

Next, an embodiment of this invention will be described based on FIGS. 1 and 2 of the accompanying drawings.

In the figure, 1 is a valve box connected to a pipe line, and fluid usually flows into the upstream side A and flows out to the downstream side B.

A swing arm 3 is attached to the valve body 1 by a valve shaft 2, and a valve body 5 is supported on the arm 3 by a pivot hinge 4.

A stepped portion 6 into which the annular member 7 fits is formed on the inner surface of the valve body 5 .

The annular member 7 is fitted into an annular groove 9 provided around the valve port 8 of the valve case 1, and the groove 9 and the annular member I form a buffer chamber 10.

As shown in FIG. 2, a plurality of bolts 11 are freely inserted around the circumference of the annular member 7 while keeping it watertight.

A threaded portion of the bolt 11 is screwed into the valve box 1 and fixed, and a spring 12 is fitted to the bolt 11 to provide elasticity in a direction that pushes the annular member 7 out of the buffer chamber 10 as well.

The head of the bolt 11 (the peeling-like member 7 is pulled out more than the specified value)
It acts as a stopper to prevent this.

Further, this head fits into a recess 13 of the annular member 7, and when the annular member 7 is pushed in against the spring 12, the bolt 11
There is also a recess 1 in the valve body 5 so that the head does not touch the valve body 5.
3' is provided.

Further, as shown in FIGS. 1 and 3, the annular member 7 is provided with a passage 14 that communicates with the buffer chamber 10 and the valve chamber 16, and is located at a position that does not intersect with the passage 14. ,
An auxiliary valve port 15 is provided that communicates in the radial direction of the annular member 7, that is, from the outer surface to the inner surface.

This auxiliary valve port 15 is provided.

The annular member 70 portion does not fit into the groove 9 when the valve body 5 is in the open state, but fits into the groove 9 when the valve body 5 is in the closed state.

A valve seat 17 is provided on the outer periphery of the opening end of the groove 9, and the surface of the valve body 5 on the outside of the stepped portion 6 comes into pressure contact with the valve seat 17.

A flow rate adjustment passage 18 communicates with the buffer chamber 10, one end of which is open to the pipe line on the upstream side A, and a flow rate adjustment valve 19 is provided in the middle of the passage.

In the embodiment of this invention described above, when fluid is flowing through the pipe, the pipe is opened as shown by the chain line in FIG. 1, allowing free passage of fluid.

In this case, the annular member 7 is pushed out by the pressing force of the spring 12 to a position where the volume of the buffer chamber 10 is maximized,
The passage 14 fills the buffer chamber 10 with the same flow of fluid and at the same pressure as in the valve chamber 16 .

In this case, the auxiliary valve port 15 is outside the groove 9.

Next, when the fluid in the pipe flows backward for some reason, the valve body 5 begins to close as shown by the solid line in the figure, and the stepped portion 6 of the valve body 5 first comes into contact with the end surface of the annular member 7, closing the passage 14. Obstruction.

In addition, even if the valve body 5 makes contact with the annular note I at the time of contact, the annular member 7 is not pushed in by the force of the spring 12 until the valve body 5 comes into full contact with the annular member 5. The passage 14 is reliably closed before the push-in step 7 is made.

Thereafter, the valve body 5 overcomes the pressure of the spring 12 and the fluid in the buffer chamber 10 by the action of the backflow fluid, and gradually compresses the buffer chamber 10.
At the same time, the fluid in the buffer chamber 10 gradually flows out depending on the degree of adjustment of the flow rate control valve 19.

As the valve body 5 compresses the buffer chamber 10, the auxiliary valve port 1
5 is also gradually closed, and the auxiliary valve port 15 is completely closed by the valve body 5 coming into contact with the valve seat 1T, and the upstream side A and the downstream side B are completely cut off.

As described above, due to the effects of the buffer chamber 10, the flow rate control valve 19, and the auxiliary valve port 150, the backflow fluid is not abruptly shut off, thereby preventing the occurrence of water hammer.

Next, when the fluid flow returns to normal, the valve body 5 returns to the chain line position in the figure, opens the valve port 8, and the annular member 7
It returns to its original state due to the pressing force.

Although the swing type check valve has been described above, in the case of a lift type check valve, the structure can be substantially the same as that described above, except that the supporting structure of the valve body 5 is a well-known lift type.

[Brief explanation of drawings]

FIG. 1 is a sectional view, FIG. 2 is an enlarged sectional view of the annular member mounting portion, FIG. 3 is a front view of the annular member, and FIG. 4 is a sectional view of a conventional example. 5... Valve body, 7... Annular member, 8...
... Valve port, 9 ... Groove, 10 ... Buffer chamber, 12 ... Spring, 14 ... Passage,
15... Auxiliary valve port, 18... Flow rate adjustment passage, 19... Control valve.

Claims (1)

[Scope of utility model registration request] A groove is provided in the valve box area around the valve port, an annular member is fitted into the groove to form a buffer chamber, a bolt is inserted into the annular member while keeping it watertight, and one end of this bolt is fixed to the valve box. The annular member is biased in the direction of pushing out by an elastic body provided in the buffer chamber, and the annular member is provided with a passage connecting the buffer chamber and the valve chamber, and an outer surface of the portion protruding from the buffer chamber in the valve open state. an auxiliary valve port that communicates with the inner surface; a flow rate control passage that communicates with the groove upstream of the valve port; and a flow rate control valve that can adjust the flow rate of the passage from outside the valve box; A check valve comprising a valve body that closes the valve chamber and a valve seat that is in pressure contact with the outer periphery of the groove.