JPH089859B2 - Water pressure controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water pressure control device that can be used as a safety valve or a pressure reducing valve by reducing the pressure in a pipe for a waterway to a constant pressure in the fields of irrigation, water supply and the like.

[0002]

2. Description of the Related Art Conventionally, there is no suitable water pressure control device for agricultural water, etc., in which dust is floating, so in order to obtain the required water pressure, place a water tank at the nearest high place or on a steel tower. There has been adopted a method in which a constant water level valve such as a so-called ball tap is used to temporarily reduce the flowing water in a pipe for a waterway to atmospheric pressure and obtain a required water pressure by natural pressure. In addition, when a steel tower was not possible, a high-pressure pipe was used to withstand the high pressure delivered to the end of the waterway. in this way,
If there is no high place in the vicinity, there is no other way than to construct a tower or use a pipe, and it is unavoidable that it will be extremely uneconomical.

By the way, at the diversion point of the pipe for the waterway,
By installing a pressure reducing valve with specifications and standards similar to those used in hydraulic equipment, when dividing running water flowing at high pressure in the pipe, the water pressure is reduced to keep the water pressure in the downstream pipe constant. Can be Actually, it is sufficient if the amount of running water in the pipe is an appropriate amount, but if water is not used at all in the downstream, or if water is not required for agricultural water etc., if there is water leakage from the pressure reducing valve Since the pipe is destroyed, a safety valve is also required to release part of the water into the atmosphere when the water pressure inside the pipe becomes abnormally high.

Here, the pressure reducing valve and the safety valve will be described with reference to a balance piston type which is found in the field of hydraulic pressure. First, the structure of the safety valve will be described with reference to FIG. A safety valve 2 is provided at an intermediate position of a pipe 1 in which a pump is connected to the upstream side and a piston or the like is connected to the downstream side, and a piston 3 included in the safety valve 2 is attached to the inside of the pipe 1 so as to be movable back and forth. Further, the return pipe 4 is opened and a valve seat 5 is formed on the inner peripheral surface of the pipe 1 on the advancing side of the piston 3. Further, a secondary pressure chamber 6 for containing oil liquid is formed behind the piston 3, and a spring 7 is mounted in a recess formed in the rear portion of the piston 3. Normally, the tip of the piston 3 is pressed against the valve seat 5 by the spring 7 and the hydraulic pressure of the secondary pressure chamber 6. The secondary pressure chamber 6 and the inside of the downstream side of the pipe 1 are communicated with each other by a choke 8 which is a small-diameter hole formed in the piston 3. Further, the inside of the secondary pressure chamber 6 is communicated with the inside of the return pipe 4 via the needle valve 10 crimped by the force of the spring 9 and the drain hole 11 penetrating the piston 3. Next, the operation of the safety valve 2 will be described. When the hydraulic pressure on the downstream side of the pipe 1 becomes higher than a predetermined pressure, the needle valve 10 is pushed by the hydraulic pressure and the spring 9 contracts, so that the oil liquid in the secondary pressure chamber 6 passes through the drain hole 11 and the return pipe 4 to the tank. Since the choke 8 has a small diameter, the pressure in the secondary pressure chamber 6 decreases, the piston 3 is pushed up by hydraulic pressure, and the tip of the piston 3 moves away from the valve seat 5 and the oil on the upstream side of the pipe 1 is removed. Part of the liquid is returned to the inside of the tank through the return pipe 4, and the hydraulic pressures on the upstream side and the downstream side of the pipe 1 decrease and become normal.

Next, the structure of the pressure reducing valve will be described with reference to FIG. A pressure reducing valve 14 is provided at the connecting portion between the primary pipe 12 and the secondary pipe 13, and a piston 15 is slidably attached. The piston 15 has an intermediate outer peripheral portion cut to form a flow passage 16 therein, and a spring 17 is housed therein. Also,
A valve portion 18 is formed on the outer periphery of the front portion of the piston 15, and a small diameter choke 19 that communicates with the secondary pipe 13 and the flow path 16 is formed.
Then, the valve portion 18 expands or contracts the diameter of the flow path from the primary pipe 12 to the secondary pipe 13. The flow path 16 communicates with the inside of a secondary pressure chamber 20 provided on the left side of the piston 15 in the drawing, and the secondary pressure chamber 20 communicates with a return pipe 22 via a drain hole 21. A needle valve 23 is arranged at the outlet of the secondary pressure chamber 20 and is pressed and closed by the force of a spring 24. Next, the operation of the pressure reducing valve 14 will be described. When the pressure in the secondary pipe 13 becomes higher than a predetermined value, the needle valve
23 is pressed by the hydraulic pressure and the spring 24 contracts, the oil in the secondary pressure chamber 20 flows out into the return pipe 22 through the drain hole 21, and the choke 19 has a small diameter. The pressure of
The piston 15 is pushed leftward in the figure by the hydraulic pressure, the gap between the valve portion 18 and the primary pipe 12 is squeezed, the flow rate is reduced, the pressure in the secondary pipe 13 is reduced, and the pressure returns to normal. The spring 17 is the piston 15.
This is to prevent instability of the position of.

[0006]

As described above, simplification is expected by using the pressure reducing valve and the safety valve used in the oil system. However, dust is floating in agricultural water, etc., and even if the conventional pressure reducing valve and safety valve are simply used, it is sufficiently predicted that dust will be caught in the gap of the sliding part of the piston, and it will be practically used. I was in difficulty.

It is an object of the present invention to provide a water pressure control valve capable of reducing the pressure even in agricultural water containing dust.

[0008]

In order to achieve the above object, the present invention installs a diaphragm valve, which is opened and closed by expansion and contraction of a diaphragm chamber, at the end of a water discharge pipe branched from a main flow pipe waterway to be controlled. the pressure sensing device having a wall surface of the diaphragm with providing the atmosphere the diaphragm chamber
Alternatively disposed a control valve having a valve chamber for communicating the water discharge pipe, the valve body in the valve chamber, expansion and contraction of the diaphragm
To the atmosphere and when the diaphragm expands
It is characterized in that it is provided so as to communicate with the diaphragm chamber .

Depending on the purpose, a diaphragm valve that opens and closes by expansion and contraction of the diaphragm chamber is attached to the end of the water dividing pipe branched from the main flow, and the tip of the water dividing pipe and the diamond valve are attached.
Surround the flam valve with a water diversion tank that is shielded from the outside air.
One, in communication with the tube waterway to be controlled, providing a hydraulic sensing device having a wall of da <br/> Iyafuramu the partial water tank, the da
A control valve having a valve chamber for communicating the ear diaphragm chamber with the water diversion pipe or the water diversion tank is provided, and a valve element in the valve chamber is provided.
To the expansion and contraction of the diaphragm , and
When the yafram expands, the water dividing pipe and the diaphragm chamber
Is provided so as to communicate with each other.

[0010]

[Operation] First, the discharge pipe is branched into the pipe to be controlled.
And, providing the water pressure sensing device to the water discharge pipe, the diaphragm is inflated by increasing the pressure of the tube waterways. As a result, the valve body moves, the diaphragm chamber communicates with the atmosphere, and the diaphragm
Since the pressure in the ram chamber becomes lower than the water pressure in the discharge pipe, the diaphragm valve opens and reduces the pressure in the pipe water passage. When the water pressure is sufficiently normal, the diaphragm contracts, the valve body returns to its original position , and the die
The diaphragm chamber is in communication with the water discharge pipe and the diaphragm valve is closed.
Jijiru Further, when a water flow is obtained from the water dividing pipe through the diaphragm valve, similarly, when the diaphragm expands due to the increase of the water pressure, the water pressure of the water dividing pipe is introduced into the diaphragm chamber via the valve chamber. Here, the diaphragm chamber inflation opening becomes minute water tank and narrow diaphragm valve by the
It prevents the high pressure from being transmitted to the pipe channel .

Next, the commonly constructed diaphragm valve has no sliding portion, so dust cannot be caught therein. Even if the dust is caught between the valve body and the valve seat of the diaphragm valve, the dust is released when the valve body is opened due to an increase in the amount of water used thereafter. Further, by widening the width of the valve chamber accommodating the valve body of the control valve, dust is not caught laterally of the valve body. Further, although dust may be caught between the valve body and the valve seat, even if it is caught, the dust is released if the valve body separates. Needless to say, the diaphragm does not hinder dust. Also, since the diaphragm position originally responds very sensitively to changes in water pressure, the control valve and diaphragm valve may constantly open and close, but the weight of the connecting rod is supported by a spring with an appropriate spring constant. Therefore, the diaphragm valve will not open and close without meaning. Since it is a common practice to install a strainer at the supply port of the water discharge pipe or the water distribution pipe, large dust particles in the sidestream can be removed.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As described above, the water pressure control device targets the pressure reducing valve, but also the similar safety valve. First, a safety valve whose description is relatively simple will be described. As shown in FIG. 1, a water discharge pipe 26 is branched from a water supply pipe 25 through which agricultural water or the like flows, and a safety valve 29 including a diaphragm valve 27 and a control valve 28 is connected in series.

The tip of the water discharge pipe 26 is opened to form a valve seat 30 of the diaphragm valve 27, and a frame body 32 having a substantially truncated cone shape is installed above the valve seat 30 for communicating with the control valve 28. Thus, a diaphragm chamber 34 is formed by stretching a diaphragm 33 on the outer periphery of the lower portion of the frame body 32. A valve body 35 is horizontally fixed to the lower surface of the diaphragm 33, and a cap 36 made of a part of a spheroid whose horizontal diameter is substantially equal to the inner diameter of the water discharge pipe 26 is fixed to the lower portion of the valve body 35. ing.

A water supply pipe 37 communicating with the control valve 28 is connected to the peripheral wall of the water discharge pipe 26, and the diameter of the opening is enlarged to provide a strainer 38. Further, the inside of the water pressure detecting device 41 in which the diaphragm 40 is stretched over the water pressure detecting tank 39 having an opening at the upper side is communicated with the inside of the water discharge pipe 26 via the water pressure detecting pipe 42.

The control valve 28 is provided above the water pressure detecting device 41, and an upper valve cylinder 43, a valve chamber 44 and a lower valve cylinder 45 are vertically connected to each other, and an upper valve seat 46 and a lower valve seat 47 are connected to the connecting portion. Has been formed. The upper valve cylinder 43 communicates with the water supply pipe 37, the wide valve chamber 44 communicates with the diaphragm chamber 34 through the water communication pipe 31, and the lower valve cylinder 45 is opened to the atmosphere in the vicinity thereof. A drainage pipe 48 is connected. Further, a connecting rod 49 penetrates through the upper valve cylinder 43 and the lower valve cylinder 45 and protrudes in the air above and below, and a water pressure adjusting handle 50 is fitted with a screw near the upper end of the connecting rod 49, and in between A spring 51 is interposed between the diaphragm 51 and the diaphragm 40 is fixed to the lower end of the connecting rod 49. Then, the valve body 52 is built in the valve chamber 44 by being fixed to the connecting rod 49, and the upper packing 53 and the lower packing 54 are provided near the ends of the upper valve cylinder 43 and the lower valve cylinder 45 of the connecting rod 49, respectively. Is fixed and made watertight.

In addition, when the diaphragm valve 27 opens and closes,
The heights of the valve chamber 44, the upper valve seat 46 and the lower valve seat 47 are made sufficiently small so that the movements of the valve body 52 and the diaphragm 40 are minimized, while the valve body 52 slides and its resistance is reduced. The width is made large enough so that the dust does not become large or dust is not caught on its side. Further, the spring constant of the spring 51 is preferably adjusted in consideration of both the water pressure difference between the start and end of the operation of the diaphragm valve 27 being as small as possible and the number of times of repeating opening / closing operations being as small as possible. The weight of the connecting rod 49 is set so that the spring 51 is loaded.

Next, the operation will be described. When the water pressure in the water discharge pipe 26 is lower than the predetermined value, the diaphragm 40 of the water pressure detection device 41 has shrunk, so the valve body 52 of the control valve 28 is crimped to the lower valve seat 47, and the diaphragm 33 of the diaphragm valve 27.
Is inflated, and the valve element 35 is crimped to the valve seat 30 at the opening of the water discharge pipe 26. Therefore, there is no water discharge from the discharge pipe 26 and no drainage from the drain pipe 48. Further, the water pressure adjusting handle 50 of the control valve 28 allows the diaphragm of the water pressure detecting device 41 to be controlled.
The downward load of the connecting rod 49 on the 40 can be adjusted. It goes without saying that the diaphragm 40 has little resistance to changes in water pressure. Since the valve body 52 of the control valve 28 does not slide as described above, the resistance of the valve body 52 is also small. Furthermore, the movement of the valve body 52 is also small. When the amount of water used downstream of the water supply pipe 25 decreases and the water pressure in the water discharge pipe 26 becomes slightly higher than a predetermined value, the diaphragm 40 of the water pressure detection device 41 swells, and the connecting rod of the control valve 28.
49 is pushed up, the valve body 52 approaches the upper valve seat 46, and the valve chamber
The inlet to 44 is pinched, the amount of inflow from the water discharge pipe 26 into the valve chamber 44 is reduced, and the water pressure in the valve chamber 44 is reduced. Therefore, the water in the diaphragm chamber 34 of the diaphragm valve 27 is discharged, the diaphragm 33 is shrunk, the valve body 35 is pushed up by the water pressure in the water discharge pipe 26 and rises, and the water in the water discharge pipe 26 is discharged to the atmosphere. As a result, the water pressure in the water discharge pipe 26 decreases.

When the diaphragm valve 27 is slightly opened and the water pressure in the water discharge pipe 26 becomes normal, the diaphragm 40 of the water pressure detecting device 41 is shrunk and the connecting rod 49 of the control valve 28 and the valve body 52 are lowered. Since the water pressure in the valve chamber 44 rises, the outflow of the diaphragm valve 27 from the diaphragm chamber 34 is stopped, the valve body 35 stands still, and water discharge is continued. However, when the amount of water used downstream of the water supply pipe 25 increases again and the water pressure in the water discharge pipe 26 falls below a predetermined value, the diaphragm of the water pressure detection device 41
It goes without saying that the diaphragm valve 27 closes when 40 is deflated. Also, by selecting the spring constant of the spring 51 of the control valve 28, even if the water pressure in the discharge pipe 26 constantly fluctuates, the fluctuation of the water pressure will be left too large, while the diaphragm will be too sensitive. The opening and closing of the valve 27 is not constantly repeated.

Next, the operation of the cap 36 of the diaphragm valve 27 will be described. If the diaphragm valve 27 is closed abruptly, a water hammer may occur in the water supply pipe 25 and the water discharge pipe 26, causing an abnormal rise in water pressure and breaking the pipe. In order to prevent a water hammer when manually closing, it is necessary to sufficiently slow the closing speed from the time of approaching the state close to the fully closed state, and this can be executed. However, it goes without saying that, on the other hand, changes in water pressure should be dealt with as soon as possible. Therefore, in order to satisfy the above-mentioned two requirements, it is necessary to increase the descending speed of the valve element 35 at the beginning and slow it at the end, but the mechanism for controlling the descending speed is extremely complicated. Therefore, in the present invention, the cap 36 is provided instead of controlling the descending speed. cap
Since the rate of increase in the horizontal cross-sectional area of 36 is large in the lower part and small in the upper part, it will close very slowly at the end of operation, so water hammer will be prevented without controlling the descending speed of valve body 35. You can

Next, the structure of the pressure reducing valve will be described. Only the points that differ from the above-described safety valve 29 in the operation as well as the configuration will be described. As shown in FIG.
The pressure reducing valve 55 is a water dividing pipe branched from the high pressure main pipe water passage 56.
A water supply pipe 25 for water supply is provided at 57. The diaphragm valve 27 has the same configuration, but is surrounded by the water diversion tank 58 including the valve seat 30 of the water diversion pipe 57. This water tank
The water pipe 25 is connected to 58. In addition, the water pressure detection device 41
The water pressure detection pipe 42 is opened in the water diversion tank 58 on the downstream side of the pressure reducing valve 55.

Further, in the case of the above safety valve 29, the water pressure on the upstream side is controlled, whereas in the case of the pressure reducing valve 55, the water pressure on the downstream side is controlled. Therefore, the movement of the pressure reducing valve 55 depends on the above safety valve 29.
And the opposite. Therefore, the water supply pipe 37 is connected to the lower valve cylinder 45 instead of the upper valve cylinder 43 of the control valve 28, the drain pipe 48 is attached to the upper valve cylinder 43, and the other end is connected to the water diversion tank 58.

Next, the operation of the pressure reducing valve will be described. The amount of water used downstream of the water pipe 25 is reduced, and
If the water pressure inside becomes slightly excessive, the diaphragm 40 of the water pressure detecting device 41 swells and pushes the connecting rod 49 upward. As a result, when the valve body 52 of the control valve 28 rises and approaches the upper valve seat 46, the outlet of the valve chamber 44 is pinched, and the water pressure inside the valve chamber 44 rises. Then, water flows into the diaphragm chamber 34 of the diaphragm valve 27, the valve body 35 descends, approaches the valve seat 30, and the water tank
The inflow into 58 decreases and the water pressure decreases. However, in the middle of the above closing operation, if the water pressure in the water diversion tank 58 decreases from the high pressure state in accordance with the downstream usage situation, the diaphragm 40 contracts, the valve body 52 descends, and the valve chamber
Since the water pressure in 44 decreases, the water pressure in the water diversion tank 58 becomes normal, and the diaphragm valve 27 remains stationary and the flow rate becomes constant.

If the amount of water used downstream of the water supply pipe 25 increases and the water pressure in the water diversion tank 58 drops slightly from normal, the diaphragm 40 of the water pressure detection device 41 will shrink and the valve body of the control valve 28 will shrink.
52 descends. Then, the inlet of the lower valve seat 47 is squeezed to reduce the water pressure in the valve chamber 44, the water in the diaphragm chamber 34 of the diaphragm valve 27 flows out, the diaphragm 33 is deflated, and the water pressure in the water dividing pipe 57 is increased. The valve body 35 is pushed up, the diaphragm valve 27 is opened, the amount of inflow into the water diversion tank 58 increases, and the pressure returns to normal. Of course, if the water pressure returns to normal, the diaphragm valve 27 will remain stationary. Further, since the diaphragm valve 27 is stored in the water diversion tank 58 and high pressure water pressure is applied to the valve body 35 from below, the water pressure in the diaphragm chamber 34 is always higher than that in the water diversion tank 58. Therefore, water that is no longer needed when the diaphragm valve 27 is opened is collected in the water diversion tank 58 through the drain pipe 48.

[0024]

As described above, the safety valve and the safety valve according to the present invention are
And the pressure reducing valve use a diaphragm valve to increase the valve seat opening.
Since it has been improved, it is resistant to floating dust in the water and highly reliable . With regard to the installation of the pressure reducing valve, it is possible to directly divide water from the high-pressure main pipe channel without installing a water tank at a high place as in the conventional case or using a high-pressure pipe. The safety valve and pressure reducing valve according to the present invention are
Since the basic structure is the same, it is easy to manufacture and can be installed in a waterway.
Installing a safety valve downstream of the pressure reducing valve is a simple
Therefore, double safety of the pressure reducing valve and the water pipe can be ensured . Thus, the water pressure control device of the present invention simplifies the installation work and reduces the cost.

[Brief description of drawings]

FIG. 1 is a side sectional view of a water pressure control device as a safety valve according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a water pressure control device as a pressure reducing valve according to an embodiment of the present invention.

FIG. 3 is a side sectional view showing a conventional safety valve.

FIG. 4 is a side sectional view showing a conventional pressure reducing valve.

[Explanation of sign]

 25 ... Water channel 26 ... Water discharge pipe 27 ... Diaphragm valve 28 ... Control valve 34 ... Diaphragm chamber 40 ... Diaphragm 41 ... Water pressure detection device 44 ... Valve chamber 52 ... Valve body 56 ... Water diversion pipe

Claims (2)

[Claims] The end portion of claim 1. A water discharge pipe which is branched from the main flow of the tube waterway to be controlled, providing a hydraulic sensing device having a wall surface of the diaphragm is attached to a diaphragm valve for opening and closing the expansion and contraction of the diaphragm chamber, the diaphragm chamber were disposed a control valve having a valve chamber for communicating the large <br/> air or water discharge pipe, the valve body in the valve chamber, Rise of the diaphragm
And contract with the atmosphere when the diaphragm expands.
A water pressure control device provided so as to communicate with the diaphragm chamber . 2. A diaphragm valve that opens and closes by expansion and contraction of the diaphragm chamber is attached to the end of the water diversion pipe branched from the main flow.
The outer part of the diversion pipe and around the diaphragm valve.
A pipe that is surrounded by a water diversion tank and that is controlled
Communicates with the water channel, the water pressure sensing device having a wall surface of the diaphragm to the partial water tank provided, arranged a control valve having a valve chamber for communicating the diaphragm chamber to said diversion pipe or minute water tank, the valve chamber Replace the valve body with the diaphragm
Linked to expansion and contraction, and at the time of expansion of the diaphragm,
Provided to connect the water dividing pipe and the diaphragm chamber.
A water pressure control device characterized in that