JPS6353431B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic shutoff valve that closes the automatic valve by allowing a portion of liquid upstream of the automatic valve to flow into the valve operating liquid chamber.

This type of automatic shutoff valve is conventionally known, and its structure, as shown in FIG. It is divided into a main flow path 2A on the side and a main flow path 2B on the downstream side, and an automatic valve 4 is arranged corresponding to the main valve seat 3.

A flexible membrane 5 made of an elastic member such as rubber is connected to the automatic valve 4, and a valve operating liquid chamber 7 is formed between the flexible membrane 5 and the upper lid 6.
is connected to the main flow path 2A on the upstream side by a pilot flow path 8, and is also connected to a drain path 10 in which an operating valve 9 such as a solenoid valve or a ball tap is arranged.

Reference numeral 11 denotes a constriction section provided in the pilot flow path 8, and the pilot flow path 8 on the upstream side of the constriction section 11
A strainer 12 is provided inside.

According to such a conventional automatic shutoff valve, the orifice diameter (φA) of the orifice portion 11 disposed within the pilot flow path 8
The selection was difficult.

That is, if the throttle diameter (φA) of the throttle part 11 is set large, when the operating valve 9 in the liquid drain path 10 is closed to close the automatic valve 4, there will be a large amount of water inside the main flow path 2A on the upstream side in the operating liquid chamber 7. Since the liquid suddenly flows in from the pilot channel 8 through the constriction part 11, the automatic valve 4 is suddenly closed.

If the automatic valve 4 suddenly closes in this way, the main flow path 2
A water hammer phenomenon occurred inside the device, inducing vibration and noise, which caused problems in practical use. On the other hand, if the throttle diameter (φA) of the throttle part 11 is set small, when the operation valve 9 is closed, liquid is gradually supplied from the pilot flow path 8 into the operating liquid chamber 7, so that the automatic valve 4 The blockage occurs slowly and the water hammer phenomenon described above does not occur. However, on the other hand, when the operating valve 9 is opened and the liquid in the operating liquid chamber 7 is discharged from the drain path 10, and the automatic valve 4 is in the open state where the automatic valve 4 is brought into contact with the stopper S, the drain path 10 Inside is aperture part 11
A small amount of liquid, which is limited by
Since the diameter is larger than the throttle diameter (φA) of the constriction part 11, the liquid flowing in the drain path 10 causes an air lock phenomenon, which causes the flow of the liquid in the drain path 10 to be intermittent. This caused instability and caused vibration and noise, which was also a practical problem.

Furthermore, a strainer 12 is disposed upstream of the throttle part 11 to remove foreign substances such as dust contained in the liquid flowing into the throttle part 11, and the automatic valve 4 is opened and closed reliably. Since liquid always flows into the strainer 12 in a fixed direction (from the pilot flow path 8 to the valve operating liquid chamber 7), foreign matter adheres to the strainer 12 over time, making it necessary to periodically clean the strainer 12, which is troublesome. It was hot.

The present invention has been made in view of these drawbacks, and its object is to provide an automatic shutoff valve that is free from water hammer and air lock phenomena.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 2. (Those with the same structure as the conventional one shown in FIG. 1 will be omitted from description and the same reference numerals will be used.) 20
is a pilot flow path that connects the main flow path 2A on the upstream side and a drain path 21 having an operating valve 9 therein. Reference numeral 22 denotes a sub-flow path which branches from the pilot flow path 20 and communicates the pilot flow path 20 with the valve actuation liquid chamber 7 constituted by the flexible membrane 5 and the upper lid 6. A throttle section 23 is provided to control the opening/closing time of the automatic valve 4, and a strainer 24 is provided in the sub-flow path 22 on the upstream side of the throttle section 23.

Note that 25 is a stop ring for fixing the strainer 24, and 26 is a closing screw.

In particular, the throttle diameter (φC) of the throttle section 23 is selected to be an appropriate diameter (for example, around 1 mm) so that the water hammer phenomenon does not occur in the main flow path 2 when the automatic valve 4 is closed. The flow path diameter (φD) of the flow path 20 is selected to be an appropriate diameter (for example, around 5 mm) so that an air lock phenomenon does not occur in the drain path 21.

According to this configuration, when the automatic valve 4 is closed, the operating valve 9 in the drain path 21 is closed, and the liquid in the upstream main channel 2A flows from the pilot channel 20 into the sub channel 22. After the foreign matter is removed by the strainer 24, the amount of foreign matter to be supplied is controlled by the throttle section 23, and the fluid is supplied into the working fluid chamber 7.

At this time, in particular, the throttle diameter (φC) of the throttle part 23 was selected to be an appropriate diameter so that the water hammer phenomenon would not occur in the main flow path 2 when the automatic valve 4 was closed. The liquid flows into the valve operating liquid chamber 7, and the automatic valve 4 slowly closes the main valve seat 3. Therefore, no water hammer phenomenon occurs in the main flow path 2, and vibrations and
Noise can be completely removed.

Next, when opening the automatic valve 4, the drain path 21
The operation valve 9 in the valve is opened to cause the liquid stored in the valve operating liquid chamber 7 to flow out from the sub flow path 22 through the pilot flow path 20 and into the drain path 21. Channel diameter of channel 20 (φD)
is selected to have an appropriate diameter so that no air lock phenomenon occurs in the discharge passage 21, and when the automatic valve 4 is opened, the liquid from the upstream main passage 2A and the liquid in the valve operating liquid chamber 7 are piloted. Since the liquid flows into the drain path 21 through the flow path 20, no air lock phenomenon occurs in the drain path 21.

In addition, in the open state of the automatic valve 4 in which the automatic valve 4 is in contact with the stopper S, the pilot flow path 20
Since the liquid in the main flow path 2A on the upstream side flows into the drain path 21, and sufficient liquid flows out into the drain path 21, an air lock phenomenon does not occur in the drain path 21, and the drainage is completed. The liquid flow in the liquid path 21 is continuous and stable, and there is no vibration or noise.

In addition, a strainer 2 disposed within the sub-channel 22
4, when the automatic valve 4 is closed, the direction of liquid flow is from the pilot flow path 20 to the sub flow path 2.
2. Liquid flows into the valve operating liquid chamber 7 and foreign matter adheres to the upper surface of the strainer 24 in the figure.On the other hand, when the automatic valve 4 is opened, the liquid in the valve operating liquid chamber 7 flows backward from the sub-flow path 22 into the pilot flow path 20 with discharge pressure,
The foreign matter attached to the upper surface of the strainer 24 is peeled off from the strainer 24, and this peeled foreign matter is
A large volume of liquid flowing through the pilot channel 20 is discharged from the drain channel 21. Therefore, the strainer 24 can reliably perform a self-cleaning function of foreign matter when the automatic valve 4 is opened and closed.
Furthermore, the occurrence of water hammer phenomenon in the main flow path 2 when the automatic valve 4 is opened/closed is relatively less likely to occur during the opening operation than when the automatic valve 4 is closed, so the opening time of the automatic valve 4 is equal to the closing time. compared,
It is required to open the valve as soon as possible and quickly supply liquid into the main flow path 2. In order to satisfy this requirement, an automatic valve is constructed with the structure shown in Figs. 3 and 4. It is possible to provide a time difference in the opening/closing operation time of No. 4.

That is, in the figure, 27 is the pilot flow path 2.
This is an annular sub-flow chamber for branching to the sub-flow path 22 provided at 0, and an annular strainer 28 connected to the sub-flow path 22 is disposed in the annular sub-flow chamber. A check valve 30 having a small diameter constriction part 29 for controlling the closing time of the automatic valve 4 is provided in the flow path 22, and the check valve is connected to the valve operating liquid chamber 7.
The valve seat 31 is movably disposed on a sub-flow passage valve seat 31 that opens inward and has a larger diameter than the throttle part 29 that controls the opening time of the automatic valve 4.

According to this structure, when the automatic valve 4 which closes the operating valve 9 is closed, liquid flows into the valve operating liquid chamber 7 from the pilot flow path 20 and the sub flow path 22, and the check valve is closed by the liquid pressure. 30 is pressed against the sub-channel valve seat 31, so that a small amount of liquid, which is restricted by the small-diameter constriction part 29 of the check valve 30, flows into the valve operating liquid chamber 7, and the automatic valve 4 is slowly activated. There is no possibility that water hammer phenomenon will occur in the main flow path 2 due to blockage.

On the other hand, when the automatic valve 4 is opened by opening the operation valve 9, the liquid in the valve operation liquid chamber 7 flows out from the sub flow path 22 to the pilot flow path 20, and at this time, the check valve 30 is activated. The liquid pressure from the liquid chamber 7 separates the sub-flow path valve seat 31 from the sub-flow path valve seat 3.
Since the restricted liquid increased in step 1 flows out, the automatic valve 4 immediately opens the main valve seat 3 and can quickly supply liquid into the main flow path 2. Moreover, the pressure of the liquid flowing through the pilot flow path 20 is
It fluctuates greatly due to pressure changes in the upstream main channel 2A and pressure changes in the drain channel 21, and this pressure change causes a change in the flow rate of the liquid flowing into the valve operating liquid chamber 7 from the sub channel 22. This causes a large change in the closing time of the automatic valve 4, inducing a water hammer phenomenon, and making it difficult to use the valve. In order to solve this problem, a constant flow restrictor is arranged in the sub-flow path 22 as shown in FIG.

An example of this will be explained with reference to FIG.
is a constant flow restrictor disposed within the sub-flow path 22,
This constriction part is made of an elastic member such as rubber, and has a constriction part 33 bored in its center.

Then, the throttle part 33 supplies the set flow rate when the normal hydraulic pressure is acting in the sub-channel 22, and then when the liquid pressure in the sub-channel 22 increases, the throttle part 33 increases the rising pressure. The valve is compressed inward to reduce the diameter of the orifice, and automatically adjusts according to changes in liquid pressure to always supply a substantially constant flow rate of liquid flowing into the valve operating liquid chamber 7 regardless of the pressure difference. It is.

Therefore, a constant amount of liquid can always be supplied into the valve operating liquid chamber 7 regardless of changes in the pressure of the liquid flowing through the pilot flow path 20, so that the closing time of the automatic valve 4 can always be kept constant, and water hammer etc. The problem can be completely resolved.

As detailed above, according to the automatic shutoff valve of the present invention, the drain path 21 connected to the operation valve 9 and the main flow path 2A upstream of the automatic valve 4 are connected through the pilot flow path 20, and the pilot flow path Liquid chamber 7 for valve operation
The automatic valve 4 is provided with a branched sub-flow path 22 leading to
When the automatic valve 4 is closed, the closing operation liquid is supplied from the sub flow path 22 into the valve operation liquid chamber 7, while the automatic valve 4 is closed.
Since the liquid was supplied from the pilot flow path 20 to the drain path 21 when the automatic valve 4 was opened, the closing time of the automatic valve 4 had no relation to the opening time and was simply determined by the throttle diameter (φC ) can be set independently, so the water hammer phenomenon when the automatic valve 4 is closed can be completely eliminated.Furthermore, when the automatic valve 4 is opened, the water from the pilot flow path 20 to the drain path 21 is completely independent of the sub flow path 22. Since sufficient liquid was supplied, no air lock phenomenon occurs in the drain path 21, and problems caused by water hammer phenomenon, vibration and noise accompanying the air lock phenomenon when opening and closing the automatic valve 4 are completely eliminated, making it practical. It has great effects. In addition, in the invention of claim 1, since the strainer 24 is provided in the sub-flow path 22 on the upstream side of the constriction section 23 provided in the sub-flow path 22, the strainer 24 is provided during the opening/closing operation of the automatic valve 4. Since the reciprocating flow reliably flows, foreign matter adhering to the strainer 24 is removed, and the removed foreign matter is discharged from the pilot flow path 20 through the drainage path 21, so the strainer 24
has a self-cleaning effect, and there is no need to periodically clean the strainer 24, which is effective for use.

Furthermore, in the invention of claim 2, the throttle diameter (φC) of the throttle portion 23 disposed in the sub-channel 22 is made smaller than the flow path diameter (φD) of the pilot flow path 20, so that the automatic valve 4 is The automatic valve 4 can quickly open the main valve seat 3 without causing a water hammer phenomenon in the main flow path 2 due to gradual blockage, and can quickly supply liquid into the main flow path 2.

Further, in the invention as claimed in claim 3, a constant flow restricting section 32 made of an elastic member such as rubber and having a restricting section 33 in the center thereof is disposed in the sub flow path 22, so that the flow through the pilot flow path 20 is arranged. Since a substantially constant amount of liquid is supplied into the valve operating fluid chamber 7 regardless of changes in the pressure of the liquid, the closing time of the automatic valve 4 can be maintained constant regardless of changes in the pressure of the pilot flow path 20, thereby preventing water hammer phenomena and the like. This eliminates the problem that this occurs and causes no problems, and furthermore, the disadvantage of limiting the applications is also eliminated.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a conventional automatic shut-off valve, FIG. 2 is a vertical cross-sectional view showing one embodiment of the automatic shut-off valve according to the present invention, and FIG. 3 is a cross-sectional view of main parts showing another embodiment. , FIG. 4 is a cross-sectional view along the line of FIG. 3,
FIG. 5 is a sectional view of a main part showing another embodiment. 2... Main channel, 4... Automatic valve, 7... Valve operation liquid chamber, 20... Pilot channel, 21... Drain channel, 22... Sub-channel, 23... Throttle section, 24... …
Strainer, 32...constant flow restrictor.

Claims (1)

[Scope of Claims] 1. In an automatic shutoff valve that closes the automatic valve by allowing a part of the liquid upstream of the automatic valve to flow into the valve operating liquid chamber, the automatic valve and the drain passage 21 connected to the operating valve 9 are provided. The main flow path 2A on the upstream side of 4 is the pilot flow path 2.
0, and branches a sub-flow path 22 leading from the pilot flow path into the valve actuation liquid chamber 7, and a throttle section 23 is disposed in the sub-flow channel 22, and the sub-flow on the upstream side of the throttle section branches. An automatic shutoff valve having a strainer 24 disposed in a passage 22. 2. In an automatic shutoff valve that closes the automatic valve by allowing a part of the liquid upstream of the automatic valve to flow into the valve operating liquid chamber, the liquid drain path 21 connected to the operating valve 9 and the main stream upstream of the automatic valve 4 passage 2A and pilot passage 2
0, and branches a sub-flow path 22 that leads from the pilot flow path into the valve-operating liquid chamber 7, and also arranges a throttle part 23 in the sub-flow path 22, and connects the sub-flow path 22 to the valve-operating liquid chamber 7. An automatic shutoff valve in which the throttle diameter of the throttle part when liquid flows into the liquid chamber 7 is smaller than the throttle diameter of the throttle part when liquid flows out from the working liquid chamber 7 to the sub flow path 22. 3. In an automatic shutoff valve that closes the automatic valve by allowing a part of the liquid upstream of the automatic valve to flow into the valve operating liquid chamber, the liquid drain path 21 connected to the operation valve 9 and the main stream upstream of the automatic valve 4 passage 2A and pilot passage 2
0, the automatic shutoff valve has a branched sub-flow path 22 that communicates with the pilot flow path and communicates with the valve-actuating liquid chamber 7, and a constant flow restrictor 32 is disposed within the sub-flow path 22.