JPH07109258B2 - Automatic shutoff valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention automatically introduces the pressure of the fluid flowing in the primary side inflow passage of the valve main body into the control chamber and controls the pressure in the pressure control chamber. It relates to an automatic shutoff valve that operates the valve mechanically and is used for large-scale watering systems such as upland irrigation systems.

[Prior Art] Conventionally, a generally used automatic shutoff valve is, for example, Japanese Patent Publication No.
-2884.

This divides the center of the main body to form an inflow path and an outflow path,
In addition, a valve that moves up and down over these inflow and outflow passages to open and close the flow passage is provided, and a diaphragm that operates via a pilot valve that is separately provided above the inside of the inflow passage is installed to cause the valve to flow through the inflow passage. It is controlled to open and close by pressure.

[Problems of Prior Art] Such a conventional automatic shutoff valve has the following problems.

That is, in the water sprinkling system, when water is supplied to a plurality of sprinklers via the automatic shutoff valve, the amount of water supplied from the sprinklers changes depending on the number of operating sprinklers.

This is because water is supplied to the automatic shutoff valve by a pump or the like having a constant discharge pressure, and water is supplied to the sprinkler through the primary side inflow passage, the main valve seat, and the secondary side outflow passage of the automatic shutoff valve. Supplied.

Now, assuming that a sprinkler system with 20 sprinklers operates 10 sprinklers,
Comparing when all sprinklers are operated, when 20 sprinklers are operated, the amount of water supplied from each sprinkler is supplied from each sprinkler when compared to when 10 sprinklers are operated. The amount of water drops significantly. This is due to the fact that the water pressure flowing in the secondary outflow passage decreases (approaches the atmospheric pressure).

That is, no correction means is taken for the change in water pressure flowing in the secondary outflow passage.

Therefore, it is difficult to supply water evenly, and this is not preferable especially in the cultivation of plants that require uniform supply.

[Means for Solving Problems] [Operation] The present invention has been made in view of the above problems, and the secondary side is always uniform even when the pressure in the secondary side outflow passage decreases or rises. The main purpose of the invention is to provide an automatic shutoff valve capable of maintaining the pressure in the outflow passage, and in order to achieve the above-mentioned purpose, it is divided into a primary side inflow passage and a secondary side outflow passage by the main valve seat. A main valve that corresponds to the valve main body and the main valve seat that opens to the primary side inflow path, is formed integrally with the partition body and controls the opening and closing of the main valve seat, and covers the upper part of the partition body and the upper part of the partition body. A cover forming a pressure control chamber, a pilot inflow passage connecting the primary side inflow passage and the pressure control chamber, a pilot outflow passage connecting the pressure control chamber and the secondary outflow passage, and a pilot outflow passage. It consists of a solenoid valve that controls opening and closing, and the main In an automatic shutoff valve that opens and closes the valve seat with the main valve, the solenoid valve that is controlled to open and close by the solenoid valve in the pilot outflow passage faces the pilot outflow passage on the secondary outflow passage side, facing the secondary outflow passage side. A secondary pressure control valve seat is provided, and the secondary pressure control valve seat divides the pilot outflow passage into a first pilot outflow passage on the solenoid valve seat side and a second pilot outflow passage on the secondary side outflow passage side. The secondary pressure control valve seat is provided with a secondary pressure control valve seat that controls the effective valve seat area of the secondary pressure control valve seat according to the pressure fluctuation in the second pilot outflow passage. When opened, the secondary pressure control valve seat is opened to a certain degree by the secondary pressure control valve, and when the pressure in the second pilot outflow passage rises, the secondary pressure control valve is the effective valve of the secondary pressure control valve seat. The seat area is reduced, while the secondary pressure control valve is used when the pressure in the second pilot outflow passage drops. The effective valve seat area of the secondary pressure control valve seat is increased.

Embodiment An embodiment of the automatic shutoff valve according to the present invention will be described below with reference to FIGS. 1 and 2.

1 has a primary valve seat 2 provided at an intermediate portion and a primary inlet 3
And the secondary side outflow passage 4 is a valve body. Reference numeral 5 denotes a main valve that opens and closes the main valve seat 2. The main valve 5 is integrally attached to a partition body 6 such as a diaphragm or a labyrinth piston, and the outer peripheral end of the partition body 5 is attached to the valve body 1. The partition 5 is arranged on the end face and is sandwiched between the end face and the cover 7. Therefore, the partition body 5 and the cover 7 form a pressure control chamber 8 which is isolated from the primary-side inflow passage 3.

Reference numeral 9 denotes a spring that is contracted in the pressure control chamber 8 between the cover 7 and the partition 6, and the main valve 5 is constantly urged toward the main valve seat 2 by the spring force of the spring 9.

Reference numeral 10 is a pilot inflow path connecting the primary side inflow path 3 and the pressure control chamber 8, and 11 is a pilot outflow path connecting the pressure control chamber 8 and the secondary side outflow path 4.

An electromagnetic valve seat 12 whose opening and closing is controlled by the electromagnetic valve S is formed in the pilot outflow passage 11. (The solenoid valve S is a general type, so its explanation is omitted.) 2 from the solenoid valve seat 12
In the pilot outflow passage 11 on the secondary outflow passage 4 side, for example, a secondary pressure control valve seat 13 having a tapered surface facing the secondary outflow passage 4 side is provided, and the secondary pressure control valve seat 13 and the solenoid valve seat 12 are provided. A first pilot outflow passage 14 is formed in the pilot outflow passage 11 between
A second pilot outflow passage 15 is formed in the pilot outflow passage 11 between the secondary pressure control valve seat 13 and the secondary side outflow passage 4 side.

Reference numeral 16 is a secondary pressure control valve that corresponds to the secondary pressure control valve seat 13 and controls the opening and closing of the valve seat. The secondary pressure control valve 16 enters the first pilot outflow passage 14 and a diaphragm 17 is integrated at its end. The upper part of the diaphragm 17 is covered with the atmospheric cover 18.

Thus, the first pilot outflow passage 14 is closed by the one surface A of the diaphragm 17, and the other surface B of the diaphragm 17 and the atmosphere cover 18 form an atmosphere chamber 19. And the atmosphere chamber 19
A spring 20 is contracted therein, and the secondary pressure control valve 16 is biased in a direction away from the secondary pressure control valve seat 13 by this.

Then, the effective pressure receiving area C in the opening / closing direction of the secondary pressure control valve seat 13 of the diaphragm 17 that opens to the first pilot outflow passage 14 is the secondary pressure of the secondary pressure control valve 16 that opens to the first pilot outflow passage 14. It is larger than the effective pressure receiving area D in the opening / closing direction of the control valve seat 13.

An example in which the automatic shutoff valve V of the present invention having such a configuration is used in a sprinkling system is shown in FIG. 3. Reference numeral 30 denotes a plurality of sprinklers connected to the secondary outflow passage 4 of the automatic shutoff valve V. The operation will be described.

First, when the solenoid valve S holds the solenoid valve seat 12 closed (non-energized state) in a state where water is supplied to the primary side inflow passage 3 by a pump or the like (not shown), the pilot outflow passage 11 is closed. Therefore, the water flowing through the primary-side inflow passage 3 is stored in the pressure control chamber 8 via the pilot inflow passage 10, and the pressure in the pressure control chamber 8 is increased. According to this, the spring 9
And the pressure difference between the partition 6 and the pressure control chamber 8 side surface on the primary side inflow path 3 side of the partition 6 pushes the partition 6 downward in the drawing, so that the main valve 5 moves the main valve seat 2 Hold blocked. Therefore, there is no outflow of water into the secondary outflow passage 4, and there is no discharge of water from the sprinkler 30. This state is shown in FIG.

Next, in this state, when the solenoid valve S is energized, the solenoid valve S opens the solenoid valve seat 12. According to this, the water that has been stored in the pressure control chamber 8 and has flowed in from the primary-side inflow passage 3, the pilot outflow passage 11, the solenoid valve seat 12, the first pilot outflow passage 14, and the secondary pressure control valve seat 13 The pressure in the pressure control chamber 8 is reduced even though it escapes into the secondary outflow passage 4 via the pilot outflow passage 11. According to this, the pressure applied to the primary-side inflow passage 3 side of the partition body 6 becomes larger than the pressing force of the partition body 6 toward the main valve seat 2 side. Move upward to open the main valve seat 2.
According to this, the water in the primary-side inflow passage 3 flows out into the secondary-side outflow passage 4 via the main valve seat 2, so that water is ejected from the five sprinklers 30 as an example.

On the other hand, in the secondary pressure control valve 16, water flows in the first pilot outflow passage 14
The pressure inside 14 rises, and due to this pressure rise, the secondary pressure control valve 16 moves upward in the figure against the spring force of the spring 20 and moves to the closed side of the secondary pressure control valve seat 13. To reduce the opening area. (The secondary pressure control valve seat 13 is not closed.) The upward movement of the secondary pressure control valve 16 causes the diaphragm 17 in the opening / closing direction of the secondary pressure control valve seat 13 opening in the first pilot outflow passage 14. The effective pressure receiving area C is set to be larger than the effective pressure receiving area D in the first pilot outflow passage 14 of the secondary pressure control valve 16 in the opening / closing direction of the secondary pressure control valve seat 13.

Next, as shown in FIG. 3, ten sprinklers are arranged.
When all 30 are opened, the pressure of the water flowing through the secondary side outflow passage 4 is significantly reduced due to the large consumption by the sprinkler 30 (close to the atmospheric pressure). According to this, the secondary pressure control valve 16 is provided with the secondary pressure control valve seat 13 at the second side of the secondary side outflow passage 4 side.
Since the pressure in the pilot outflow channel 15 will decrease, 2
The pressure applied to the lower portion G of the secondary pressure control valve 16 from the secondary pressure control valve seat 13 on the secondary pilot outlet channel 15 side of the secondary outlet channel 4 side (that is, the secondary pressure control valve 16 is the secondary pressure control valve). Since the pressure applied to the seat 13) decreases, the position of the secondary pressure control valve 16 moves in a direction away from the secondary pressure control valve seat 13 to increase the effective opening area of the secondary pressure control valve seat 13. It is a thing.

According to this, the holding pressure in the pressure control chamber 8 escapes from the pilot outflow passage 11 into the secondary side outflow passage 4, and the pressure in the pressure control chamber 8 decreases.

Therefore, the balance state of the partition body 6 which has been held until now is broken, and the partition body 6 moves upward to increase the opening area of the main valve seat 2.

Thus, the pressure in the primary-side inflow passage 3 becomes 2 via the main valve seat 2.
By being provided to the secondary outflow passage 4, the pressure drop in the secondary outflow passage 4 can be immediately suppressed and the pressure can be increased, so that the decrease in the amount of water supplied from all the sprinklers 30 can be suppressed. It is a thing.

Next, a case where only one sprinkler 30 is used from the state where the five sprinklers 30 are used will be described.

The pressure of the water flowing through the secondary side outflow passage 4 increases significantly (becomes high pressure) due to the small consumption by the sprinkler 30. According to this, since the pressure in the second pilot outflow passage 15 on the secondary outflow passage 4 side from the secondary pressure control valve seat 13 of the secondary pressure control valve 16 rises, the secondary pressure control valve 16 2 Pressure applied to the lower part G of the second pilot outflow passage 15 side of the secondary outflow passage 4 side of the secondary pressure control valve seat 13 (that is, the pressure for pressing the secondary pressure control valve 16 to the secondary pressure control valve seat 13) Therefore, the position of the secondary pressure control valve 16 moves toward the secondary pressure control valve seat 13 to reduce the effective opening area of the secondary pressure control valve seat 13.

According to this, the holding pressure in the pressure control chamber 8 is less likely to escape from the pilot outflow passage 11 into the secondary side outflow passage 4, and the pressure in the pressure control chamber 8 rises.

Therefore, the balance state of the partition body 6 which has been held until now is broken, and the partition body 6 moves downward to reduce the opening area of the main valve seat 2.

Thus, the pressure in the primary-side inflow passage 3 becomes 2 via the main valve seat 2.
Since the amount of water added to the secondary outflow passage 4 is reduced, the pressure rise in the secondary outflow passage 4 can be immediately suppressed and the pressure can be reduced, so that the amount of water supplied from all the sprinklers 30 can be reduced. It is possible to suppress the increase.

Further, the first pilot outflow passage 14 and the pilot outflow passage 11 on the pressure control chamber 8 side of the solenoid valve seat 12 are connected by the bypass pilot outflow passage 40 without the solenoid valve seat 12 and the bypass pilot outflow passage is connected. Manual on-off valve that opens and closes mechanically
When 41 is provided, the automatic shutoff valve V can be operated even when a power failure or the solenoid valve S is not operated.

If the minimum passage area of the pilot inflow passage is smaller than the minimum passage area of the pilot outflow passage, the pilot outflow passage
The pressure change in 11 can be sensitively transmitted into the pressure control chamber 8, and the pressure control of the secondary side outflow passage 4 can be performed extremely reliably.

[Effects of the Invention] As described above, the automatic shutoff valve according to the present invention has the following effects.

In the automatic shutoff valve, when the pressure fluctuation in the secondary outflow passage occurs, the pressure change is detected and the opening degree of the main valve is automatically adjusted to keep the pressure in the secondary outflow passage constant. Since it can be held, it is possible to supply a constant amount of fluid at all times, which is very industrially effective, such as uniform distribution of water in the sprinkling system.

By controlling the secondary pressure control valve with the diaphragm, friction during the operation of the secondary pressure control valve can be reduced, so the dynamic characteristics of the secondary pressure control valve, that is, the pressure controllability of the secondary side outflow passage. Can be further improved.

Because the effective pressure receiving area of the diaphragm is larger than the effective pressure receiving area of the secondary pressure control valve, when the main valve of the automatic shutoff valve is opened, the secondary pressure control valve is immediately against the secondary pressure control valve seat. It can be maintained at a constant opening that can be set, and then the secondary pressure control valve can be corrected based on the constant opening, so that it is possible to quickly respond to pressure rise and fall in the secondary side outflow passage. Is.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an automatic shutoff valve according to the present invention, FIG. 2 is an enlarged view of a main part of a secondary pressure control valve portion of FIG. 1, and FIG. 3 is an automatic shutoff for a watering system. It is a system diagram which arranged the valve. 2 ... Main valve seat, 3 ... Primary side inflow passage, 4 ... Secondary side outflow passage, 5 ... Main valve, 6 ... Partition body, 8 ... Pressure control chamber, 10
...... Pilot inflow channel, 11 …… Pilot outflow channel, 12…
… Electromagnetic valve seat, 13 …… Secondary pressure control valve seat, 14 …… First pilot outflow passage, 15 …… Second pilot outflow passage, 16 …… Secondary pressure control valve, 17 …… Diaphragm, 19 …… Atmosphere chamber, 40 ……
Detour pilot outflow passage, 41 …… Manual open / close valve,

Claims (3)

[Claims] 1. A main valve seat, which corresponds to a valve body divided into a primary-side inflow passage and a secondary-side outflow passage, and a main valve seat which opens to the primary-side inflow passage, and which is integral with a partition body. Main valve for controlling the opening and closing of the main valve seat, a cover for covering the upper part of the partition and forming a pressure control chamber in the upper part of the partition, and a pilot for connecting the primary side inflow passage and the pressure control chamber It consists of an inflow passage, a pilot outflow passage that connects the pressure control chamber and the secondary outflow passage, and a solenoid valve that controls the opening and closing of the pilot outflow passage. The main valve is opened and closed by the solenoid valve. In an automatic shutoff valve that opens and closes the seat with the main valve, the secondary valve that faces the secondary outflow channel side is the pilot outflow channel on the secondary outflow channel side of the solenoid valve seat that is controlled to open and close by the solenoid valve on the pilot outflow channel. A pressure control valve seat is provided so that the pilot outflow passage can be controlled by the secondary pressure control valve seat. It is divided into a first pilot outflow passage on the solenoid valve seat side and a second pilot outflow passage on the secondary side outflow passage side, and the secondary pressure control valve seat is secondary in accordance with pressure fluctuations in the second pilot outflow passage. A secondary pressure control valve that controls the effective valve seat area of the pressure control valve seat is arranged, and when the solenoid valve seat is opened by the solenoid valve, the secondary pressure control valve seat is opened by a certain degree by the secondary pressure control valve. At the same time, when the pressure in the second pilot outflow passage increases, the effective valve seat area of the secondary pressure control valve seat is reduced by the secondary pressure control valve, while the secondary pressure decreases when the pressure in the second pilot outflow passage decreases. An automatic shutoff valve in which the effective valve seat area of the secondary pressure control valve seat is increased by the control valve. 2. The secondary pressure control valve seat is arranged such that one surface faces the first pilot outflow passage and the other surface faces the atmosphere chamber and is elastically biased toward the first pilot outflow passage. The automatic shutoff valve according to claim 1, wherein the automatic shutoff valve is formed integrally with the diaphragm. 3. In the secondary pressure control valve, the effective pressure receiving area of the diaphragm in the opening / closing direction of the second control valve seat opening in the first pilot outflow passage 14 is defined as the secondary pressure in the opening / closing direction of the second control valve seat. The invention according to claim 2, wherein the effective pressure receiving area of the control valve in the first pilot outflow passage is larger than the effective pressure receiving area.
The automatic shutoff valve described in the item.