JPH0587268A - Water control unit for pipe line - Google Patents

Abstract

PURPOSE:To embody the following advantages: 1) heat loss is little, 2) cavitation is hard to occur and 3) ease of dust handling, in a unit which is set up in a pipe line (water pipe). CONSTITUTION:A needle body 22b of a needle valve 22 less in head loss is clamped to a water pipe 23, installing a housing 22a free of slide motion, and this housing 22a is connected to a piston rod 32c of an on-off device 32, and there is provided a pilot valve 24 which imposes hydraulic pressure to both sides or one side of a piston 32b clamped to the piston rod 32c and operating it. Since this pilot valve 24 utilizes hydraulic pressure and atmospheric pressure in the water pipe 23 at the upstream side of the needle valve 22, it operates this needle valve 22 with certainty. In addition, during stoppage of the needle valve 22, water will not flow in a conduit 26, and since a strainer 28 is attached to a tip of this conduit 26 receiving this flowing water in the water pipe 23 in parallel with this flowing water, any possible effect of dust of the pilot valve is very little. Moreover, if control over the pilot valve 24 is carried out with hydraulic pressure at the downstream side, it serves as a pressure regulating valve as well as if it is controlled by hydraulic pressure in a venturi pipe part 51 and other parts, it serves as a constant flow valve the other way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, like agricultural water,
In a pipe channel through which water containing a large amount of water and a large amount of dust passes,
The present invention relates to a water control device for a pipeline, which is unmanned and unpowered, and is installed to keep the water pressure in the downstream pipeline, the water pressure in the upstream pipeline, or the maximum flow rate constant.

[0002]

2. Description of the Related Art In general, it has been attempted to measure the stool of an area by equipping a waterway branched from an upstream river with a water control device. The water control device 1 shown in FIG. 8 is installed in a farm pond or the like, and has a cap 3 provided to face the opening 2a of the upstream water distribution pipe 2 and a cylindrical shape extending the end of the opening 2a. A piston 4 having a valve portion 4a, an operating device 5 for adjusting the flow rate, a pilot valve 6 for applying upstream water pressure to the front and rear surfaces of the piston 4, and a running water level having a free water surface for the pilot valve 6 mechanically. And a detection device 7 for transmitting the The pilot valve 6 of the water control device 1 has a pair of pistons 8, and the piston rod 9 moves in the cylinder 10 according to the detected water level, so that one of the front and rear surfaces of the piston 4 of the operating device 5 or It is designed to apply water pressure to both.

When the pilot valve 6 is operated, the water in the piston 4 is slightly discharged into the water having a free water surface. In addition, the blockage of the pilot valve 6 due to dust and the cylinder 10
A strainer 11 is attached to the connecting portion of the upstream water channel in order to prevent the accumulation of sediment inside. In this way, the piston 8 of the pilot valve 6 moves and the cylindrical valve portion 4a moves toward or away from the cap 3 to open or close the operating device 5, thereby adjusting the upstream water level or the downstream flow rate. it can. At this time, as the water level fluctuates, opening and closing will be repeated continuously, and water will be continuously discharged from the pilot valve 6.

When the water channel branched from the upstream river has a pipe structure, the globe valve 12 shown in FIG. 6 may be used.
The globular valve 12 is a pilot valve connected to the downstream side of the water distribution pipe 2.
It is installed with 13 and operates based on the running water on the downstream side. A cylinder chamber 14 is disposed inside the globe valve 12 at right angles to the axis of the external water pipe 2, a valve body 15 is slidably provided, and the head loss is increased inside the globe valve 12. The water pressure difference between the upper surface and the lower surface of the valve body 15 is increased so that the valve body 15 can be moved up and down, and the pressure in the cylinder chamber 14 is adjusted by the pilot valve 13 to operate the valve body 15 to open and close the pipeline. .. At this time, the inflow amount or the discharge amount can be adjusted by the pilot valve 13 and the adjusting shaft 16. In addition, tamagata valve
Even if the valve bodies 15 of 12 are stationary, running water will pass through the cylinder.

On the other hand, a needle valve 17 as shown in FIG. 7 may be used for a pipe water channel. Needle valve 17 is upstream part
It is composed of a streamlined needle body 18 in which 18a and a downstream portion 18b are divided and fitted together, and a housing 19 which forms and covers a flow path around the needle body 18. The housing 19 is connected to the water distribution pipe 2, and the upstream portion 18a of the needle body 18 is fixed to the housing 19 by a support member 20. This device adjusts the inflow amount or outflow amount of the flowing water flowing into the needle body 18 to adjust the water pressure in the needle body 18, and allows the downstream portion 18b of the needle body 18 to move in and out to move the housing 1
It adjusts the gap between the downstream surface of 9 and opens and closes the pipeline. The shape of the needle valve 17 has been studied in detail, and as can be inferred from the streamlined shapes of the needle body 18 and the housing 19, the head loss is the smallest among the valves that can be provided in the middle of the pipeline. Therefore, the height of the dam and the pump head can be reduced, or the gradient of the entire pipeline can be made steep to reduce the diameter and save the construction cost.

By the way, in the structure of the pipe water passage, since the pipe diameter is remarkably larger than that of hydraulic equipment, for example, the head loss of the portion other than the valve is small, and the predetermined pressure is infinitely low. Therefore, if the head loss of the valve is not as low as possible, the proportion of the head loss of the valve in the total head loss is large. Therefore, the head loss of the valve is, for example, 2m.
If it is large, the height of the dam will be nearly 2m higher, and the economic loss will be tremendously large.

Therefore, it is not suitable to install the ball valve 12 in the pipe channel because the head loss is large. Further, a large head loss and a low secondary pressure tend to cause cavitation. In addition, when the needle valve 17 with a small head loss is used, if the conduit is opened abruptly, the resistance of the downstream portion 18b of the needle body 18 is small because it is dynamic friction resistance, and it opens to a state close to full opening. When the conduit is closed from this state, the downstream portion 18b of the needle body 18 cannot move upstream due to the large static friction resistance, and the conduit is not blocked. Under such circumstances, the sphere valve 12 is used in some places in the water, and the electric valve that opens and closes the valves with electric power is used in almost all places, forcing the construction of distribution lines. ..

[0008]

As described above, in the pipe water channel, the spherical valve 12 has a problem that the head loss is large, and since the water pressure downstream of the valve is low, cavitation is likely to occur and There is a problem that it vibrates to make noise and erodes. Further, in the needle valve 17,
When moving the downstream portion 18b in the valve opening direction, the water pressure inside the needle body 18 needs to be considerably lower than that at the downstream side, and therefore there is a problem that it cannot be used if the water pressure at the downstream side is low. Further, there is an uneconomical aspect that the water in the needle body 18 is discharged into the atmosphere. In addition, the electric valve has a problem that its function is lost in the event of a power failure.

If the pilot valve 6 as shown in FIG. 8 is used as an existing valve in the pipe water passage, the hydraulic pressure applied to the sliding portion (the front and rear portions of the piston) is offset, and the hydraulic sleeve valve and cone sleeve are used. Since it is limited to valves or Howell-Banger valves, its application was limited to water (downstream running water) to water or air. Further, since the sleeve valve and the cone sleeve valve are valves that discharge water into water, they are not suitable for a pressure reducing valve or a constant flow valve provided in the middle of a pipe water passage. Also, the Howell Banger valve seems to be suitable as a safety valve because it is a valve that discharges water in the air, but it is a valve for spreading the water flow in the air and raising the water temperature, so it collects the diffused water You need a pond for it. Therefore, there is no pilot valve suitable for the pipeline, so there is a problem that the existing valve with low efficiency must be used as it is.

Further, in the pilot valve 13 used in the conventional spherical valve 12, the valve is opened and closed by adjusting the inflow amount or the outflow amount of the flowing water which is constantly flowing, and the pilot valve 13 is also used. However, there is a problem that the pilot valve 13 is likely to be blocked by dust and is difficult to repair because the valve body is built in. Further, even if the strainer 11 that filters water containing a large amount of dirt and dust is equipped with the strainer 11 because the water constantly passes through the strainer 11 even when the valve is stationary, the strainer 11 is easily clogged. There is a problem that it is difficult to clean because it is stored in the pipe.

According to the present invention, a pilot valve that operates reliably even if the head loss is small and discharges a small amount of flowing water is used in combination.
It is an object of the present invention to provide an unmanned and unpowered water control system for pipe waterways, which is less affected by dust.

[0012]

In order to achieve the above object, the present invention provides a housing for fixing a needle body between water pipes divided into an upstream and a downstream via a supporting member to cover the needle body. A needle valve slidably provided on the upstream and downstream water distribution pipes and a pair of small pistons connected to a small piston rod are slidably fitted in a small cylinder, and are located close to the inside of the pair of small pistons. And a pilot valve provided with a pair of joining chambers surrounding the outer circumference of a pair of slits circulated and drilled in the small cylinder, inside the water pipe upstream of the needle valve, and the pair of pilot valves. A control device for communicating the inside of a small piston with a small cylinder inside by a water conduit to operate the small piston rod is provided, and has a pair of the joining chambers and a cylinder divided into an upstream side and a downstream side by the piston. The upstream side and the downstream side of the cylinder of the opening / closing device are respectively connected by water pipes, and the piston housed in the cylinder of the opening / closing device and the housing of the needle valve are connected via a piston rod. To do.

Further, the control device is provided with a water pressure detecting chamber which communicates with the inside of the water pipe downstream or upstream of the needle valve, and the water pressure detecting piece and the spring, which are mounted on the water pressure detecting chamber and are composed of a diaphragm or a piston, are connected to the pilot valve. The small piston rod is connected to the small piston rod in accordance with the moving direction of the small piston rod. further,
The water pipe is provided with a Benlyuri pipe section that is narrower than the water pipe, and a water pressure detection chamber that communicates with the Benlyuri pipe unit and the upstream water pipe of the Benlyuri pipe unit is arranged, and a diaphragm attached to each water pressure detection chamber or It is also possible to adopt a configuration in which each water pressure detection piece composed of a piston and a spring are connected to the small piston rod in accordance with the moving direction of the small piston rod of the pilot valve.

Further, the tip of the water guiding pipe inserted into the water distribution pipe is formed parallel to the water flow, and the parallel leading end is closed at its tip to form a plurality of water guiding ports on the outer circumference. It is characterized in that the ring is fixed and a cloth strainer is stretched around the ring with the upstream end and the downstream end being tightly bound to the tip of the water conduit.

[0015]

With the above structure, the small piston in the pilot valve is moved when the water pressure or flow rate of the flowing water in the water distribution pipe is changed by the control device.
One slit is exposed in the air. When the slit is exposed, the water pressure on one side of the piston of the switchgear disappears, and the housing of the needle valve moves due to the water pressure in the upstream water pipe to expand or contract the water pipe passage. Therefore, even if a needle valve with less head loss is provided in the middle of the pipeline, the needle valve operates reliably regardless of the water pressure difference between the upstream and downstream sides of the needle valve. Further, since the streamline shape between the needle body and the housing is uniform, cavitation is unlikely to occur.

When the needle valve is stationary, there is no operating force of the opening / closing device, but since the diameter of the contact portion between the housing and the needle body is equal to the diameter of the upstream end, the water pressure acting on the housing is almost canceled out. , A slight unbalanced force works. Further, since frictional force is exerted on the housing, the stationary state can be safely maintained. Therefore, it does not repeat opening and closing insignificantly, and is only discharged from the cylinder when the piston moves. Moreover, in a large-scale water supply facility where the head loss of the valve becomes a problem, the fluctuation of the water pressure is remarkably slow. Therefore, the amount of water discharged is extremely small.

Further, when the water pressure in the downstream or upstream water distribution pipe is transmitted to a water pressure detecting piece composed of a diaphragm or a piston and a small piston rod supported by a spring is operated, the needle valve operates in accordance with the water pressure in the downstream or upstream. Since it opens and closes, it can be used as a pressure reducing valve or a safety valve.

If a small piston rod supported by a spring is operated by applying water pressure in a venturi pipe having a narrow water distribution pipe and water pressure in the water distribution pipe upstream of the venturi pipe, the needle can be operated according to the flow rate. Since the valve opens and closes, it can be used as a constant flow valve.

Further, the pilot valve operates the piston of the opening / closing device by air and upstream water pressure, and the operation of the piston, by extension, the needle valve becomes agile, the flow of water in the water conduit is small, and the pilot valve becomes dusty. Hard to be blocked. Further, when the valve is stationary, there is no water flow through the pilot valve, so the amount of water passing through the strainer is significantly reduced, and the effect of dust is eliminated. The strainer attached to the outer circumference of the tip of the water pipe has resistance against running water by the ring, but the crossing angle between the water flow and the strainer is also small, and the force to push dust to the strainer is small, and it is applied to the pilot valve. The dust of running water is removed and the strainer is easily cleaned.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the pipe water control device 21
First, the needle valve 22 is connected to the water distribution pipe 23, and the pilot valve 24 is connected to the water distribution pipe 23 upstream of the needle valve 22 via the water supply device 25. One end of the water conduit 26 of the water supply device 25 is inserted into the water distribution pipe 23 upstream of the needle valve 22.
The tip of the is bent inside the water pipe 23 along the flow of running water and is attached with a sufficient length. As shown in FIG. 2, the tip of the water guide pipe 26 is closed at its tip end, and a water guide port 26a composed of a large number of holes or grooves is formed in the outer periphery. Further, a ring 27 is fixed in the middle of the tip part, a strainer 28 made of cloth is tensioned and supported on the outer periphery of the ring 27, and the upstream end and the downstream end of the strainer 28 are tightly bound to the straight portion of the water conduit 26 to form an intermediate portion. The parts are appropriately wrinkled and loosened. The size of the ring 27 is
From the viewpoint of resistance to water flow and that dust does not accumulate,
It is made smaller.

In the small cylinder 24a of the pilot valve 24, a pair of small pistons 24c fixed to a small piston rod 24b.
Are slidably fitted together, and the other end of the water guiding pipe 26 is opened between the pair of small pistons 24c, that is, in the center of the small cylinder 24a via a shutoff valve 29. In addition, a pair of narrow slits are placed close to the inside of the pair of small pistons 24c.
24d is engraved all around, and the outer circumference is a pair of bonding chambers.
It is surrounded by 24e. The difference between the intervals of the small piston 24c and the slit 24d is set so that the opening / closing frequency does not become excessive within a limit in which fluctuations in water level, water pressure, or flow rate are allowable. The small piston rod 24b is a control device 30 for moving depending on the upstream water level or the downstream water level.
Is connected with.

In the pair of joining chambers 24e of the pilot valve 24, one end of the water pipe 31 is opened, and the other end is opened at the upstream and downstream ends of the cylinder 32a of the opening / closing device 32 for directly operating the needle valve 22. is doing. The height difference between the pilot valve 24 and the cylinder 32a of the opening / closing device 32 is minimized. The posture of the pilot valve 24 is arbitrary, but in the embodiment, the pilot valve 24 is placed in the upstream and downstream directions, and the water pipe
The pilot valve 24 and the opening / closing device 32 are in communication with each other without intersecting 31.

The cylinder 32a is annularly installed on the outer circumference of the water distribution pipe 23, and the piston 32b is slidably fitted in the cylinder 32a. Although it is possible to divide the cylinder 32a and the piston 32b into three or more pieces, in the embodiment, for convenience, they are formed in a single ring. In addition, three piston rods 32c (two shown) fixed to the piston 32b penetrate the side wall of the cylinder 32a, and the needle valve 22
Is coupled to the housing 22a of the. The piston 32
Packing 33 is attached to the outer circumference of b, and cylinder 32
A pair of drain pipes 34 are open on the lower surfaces of both ends of a, and the other end is open to the atmosphere by connecting a pair of cocks 35 on the way.

The needle valve 22 provided in the middle of the water distribution pipe 23 is provided so that both ends of the housing 22a are slidable around the outer circumference of the water distribution pipe 23, and the needle body 22b has three or four needle bodies at the front and rear ends with respect to running water. Blades (support members) 36 are attached and fixed to the inner surface of the water distribution pipe 23 at the upstream and downstream sides. A stopper 37 is fixed to the inner surface of the upstream end of the housing 22a,
Further, a metal 38 is mounted on the outer side so that the position is adjustable, and a V packing 39 is mounted between the stopper 37 and the metal 38. The diameters of the upstream end and the downstream end of the housing 22a are made equal. In the fully closed state, it is optional whether the needle body 22b and the housing 22a are brought into contact with each other on the upstream side or the downstream side. The contact is made at the reduced position.
In the fully opened state, the cylinder 32a and the piston 32b are held in contact with each other.

Next, the operation will be described. The embodiment shown in FIG. 1 has a configuration common to a constant water level valve, a pressure reducing valve, a safety valve, and a constant flow valve. Therefore, the action concerning each application will be described in detail later. First,
The operation of opening and closing the needle valve 22 will be described. Water pipe 23
If the internal water pressure or flow rate changes and becomes improper, the control device 30 that detects and transmits this will cause the small piston rod 24b of the pilot valve 24 to slide, exposing the slit 24d on one side in the air. This allows the piston of the switchgear 32 to
The water pressure on one side that worked on 32b disappears, and piston 32b and housing 22a slide in the upstream or downstream direction,
The needle body 22b and the needle valve 22 open or close to correct the water pressure or flow rate. Further, since the height difference between the pilot valve 24 and the cylinder 32a is made as small as possible, there is no influence of water in the water pipe, and the opening / closing device 32 operates due to the difference between the water pressure upstream of the needle valve 22 and the atmospheric pressure. , Even if there is almost no head loss, no problem will occur.

Next, the problem of cavitation will be described. It is well known that cavitation is likely to occur when the secondary pressure is low, and cavitation is most likely to occur in a safety valve that releases excess water into the atmosphere. However, the needle body 22b and the housing 22a of the needle valve 22 are streamlined, and the diameters of the upstream side and the downstream side of the housing 22a are made equal and have a relatively uniform shape. Is also suitable. It is also suitable as a pressure reducing valve or a constant flow valve provided in the middle of the pipeline.

Next, the general operation of the pilot valve 24 and the opening / closing device 32 when the needle valve 22 is at rest will be described. When the needle valve 22 is stationary, there is no actuation force on the pilot valve 24 and the opening / closing device 32. Therefore, in order to prevent the needle valve 22 from repeatedly opening and closing to change the water pressure and the flow rate and constantly discharge the water, it is necessary that the water pressure applied to the sliding portion is offset. Since the upstream and downstream diameters of 22a are the same, when the valve is open, the housing 22
The water pressure on a is offset. In addition, the needle body 22b
Since the shapes of the upstream and downstream sides of the housing 22a are almost targeted, there is almost no influence of moving water.

Even in the fully closed state, the needle body 22
Since the contact point between b and the housing 22a is the smallest downstream diameter, at least the housing 22a
The same applies to the portion facing the needle body 22b. However, in the fully closed state, no water pressure is applied to the V packing 39 on the downstream side of the needle 22, and only the V packing 39 on the upstream side is applied with water pressure toward the upstream side. However, the water pressure applied to the upstream V packing 39 is
The water pressure exerted on the upstream surface of the stopper 37 in contact with 39 is offset. Moreover, frictional force acts on the metal 38 and the V packing 39. Therefore, it is impossible for the housing 22a to move meaninglessly and continuously and to repeat the opening / closing operation.

Further, as understood from the above description, in the device according to the present invention, when the needle valve 22 is stationary, no water is discharged. Therefore,
Although the amount of water lost is only the amount of water displaced by the movement of the piston 32b, in a large valve in which the head loss is important, the law of large numbers works, so the change in water pressure is extremely slow. Further, since the difference in the distance between the small piston 24c and the slit 24d is set so that the opening / closing frequency does not become excessive, the opening / closing frequency is extremely low. Therefore, FIG.
Unlike the prior art shown in, the economic loss caused by discarding water is not a problem at all.

The pilot valve used in the present invention
24 and the opening / closing device 32 also have a unique structure in which the housing 22a of the needle valve 22 is slid, so that the head loss is small and cavitation is unlikely to occur, and when both are combined, the outstanding effect of expanding the application at once is obtained. It was Further, when the water pressure is high, the resistance of the watertight device such as the V packing becomes large. Therefore, in the prior art, the needle valve (17) shown in FIG. 7 uses the difference between the primary water pressure and the secondary water pressure to cause loss. Although it is unavoidable to increase the head of water or increase the diameter of the device, in the pilot valve 24 according to the present invention, in the case of high pressure, high pressure primary water pressure can be used without waste,
Conversely, the higher the pressure, the more advantageous it is, and the switchgear 32 can be made smaller.

Further, the operation of the pilot valve 24 and the opening / closing device 32 becomes quick, the amount of running water used is small, and the possibility of blockage due to dust becomes very low. Also, even if it gets blocked,
Since the small piston 24c is near the end of the small cylinder 24a, dust can be easily removed by closing the shutoff valve 29 and manually pulling the small piston 24c out of the small cylinder 24a.

Further, the amount of water passing through the strainer 28 is not at all in the stationary state, and is a small amount of water necessary for the movement of the piston 32b even during the operation. Further, if the length of the strainer 28 is increased without increasing the size of the ring 27, the area of the strainer 28 is increased, and the water passage speed and the water pressure difference between the inside and outside are reduced. The water pressure of the dam and pump changes very slowly, so the needle valve 22
The number of movements of is extremely small. Therefore, the amount of passing water that causes clogging of the strainer 28 is extremely small. Therefore, large dust will not get caught on the strainer 28
It is pushed downstream by the running water flowing through 23. Also, it is usually difficult to clean fine deposits such as silt, but since the strainer 28 has wrinkles and slack, the strainer 28 is fluttered in the vertical and horizontal directions by the water flow, so it is similar to rubbing and washing. The deposits are also washed away.

Although the dust is filtered by a strainer 28 made of cloth, the pilot valve 24 and the opening / closing device have been used for many years.
Deposit within 32. Since the pilot valve 24 is in a position where the small piston 24c can be seen from the outside, the dust can be easily removed by closing the shutoff valve 29 mounted on the water conduit 26 and pulling the small piston 24c out of the small cylinder 24a. In addition, the switchgear 32
Is designed to work together even if the cock 35 is opened,
The needle valve 22 does not open or close. Therefore, the foreign matter in the cylinder 32a can be discharged even during use.

Next, a concrete example of the control device 30 shown in FIG. 1 will be used to explain an application example in which a water control device is used as a pressure reducing valve for keeping a downstream water pressure constant or as a safety valve for keeping an upstream water pressure constant. To do. The water control device 40 shown in FIG. 4 is a pressure reducing valve, and the small piston rod 24b of the pilot valve 24 is lengthened to the upstream side, and its end portion changes depending on the pressure provided in the water pressure detection chamber 42 of the water pressure detection device 41. It is fixed to the water pressure detection piece 43. The water pressure detecting piece 43 is composed of a diaphragm or a piston. A pressure gauge 44 is attached to the water pressure detection chamber 42, and is connected to the inside of the water distribution pipe 23 downstream of the needle valve 22 via a water guide pipe 45 for detection. The tip portion of the water conduit 45 for detection is bent along the water flow like the water conduit 26 described above, the tip is closed, and a plurality of water holes 45a are formed in the outer periphery. A strainer 28 is attached to the bent front end via a ring 27. A safety valve can be obtained by installing the water conduit 45 for detection upstream of the needle valve 22.

Further, a spring support base 47 of a water pressure adjusting device 46 is fixed to the upstream end of the small cylinder 24a of the pilot valve 24, and a handle 48 is screwed into the small piston rod 24b, and a spring 49 is attached between them. Has been done. The length of the spring 49 is sufficiently long according to the allowable fluctuation value of the water pressure so that the change of the pressure of the spring 49 due to the movement of the small piston rod 24b can be ignored.

Next, the operation will be described. Spring 49
Is sufficiently long, if the water pressure in the water distribution pipe 23 downstream of the needle valve 22 becomes slightly high, the water pressure detection piece 43 pops out, the small piston rod 24b moves to the downstream side, and the cylinder 32a Since the slit 24d communicating with the upstream side is exposed in the air and the upstream side of the cylinder 32a communicates with the atmosphere, the piston 32b and the housing 22a move to the upstream side, the gap between the housing 22a and the needle body 22b becomes narrow, and the flow rate decreases. To do. As a result, the water pressure in the downstream water distribution pipe 23 becomes low. Therefore, the water pressure downstream is kept substantially constant. It should be noted that, if the water pressure in the water distribution pipe 23 downstream of the needle valve 22 becomes slightly low, the housing 22a moves to the downstream side and the flow rate is set to increase.

A pressure gauge 44 mounted in the water pressure detection chamber 42
Follow the instructions for the handle that holds the spring 49
By turning 48, the water pressure on the downstream side can be set arbitrarily.

Next, a description will be given of an application example in which a water control device is used as a constant flow valve for keeping the flow rate of water in the water distribution pipe 23 constant.
The water control device 50 shown in FIG. 5 is a constant flow valve, and the needle valve 22
A venturi pipe portion 51 narrowed from the water distribution pipe 23 is provided upstream of the water supply pipe 1 (or may be on the downstream side). When there is no risk of blockage due to dust, a small Venturi pipe is inserted into the water distribution pipe 23 with an emphasis on economy.

Similar to the one shown in FIG. 4, the pilot valve 24 is provided with a water pressure detecting device 41 at both ends of the small piston rod 24b, and a pair of water pressure detecting pieces 43 of the same structure and size are provided on the small piston rod 24b. It is fixed on both ends. The water pressure detection chamber 42 on the upstream side is connected to the inside of the water distribution pipe 23 on the upstream side of the venturi pipe portion 51 by the water guide pipe 52 for detection, and the water pressure detection chamber on the downstream side.
42 is connected to the inside of the Venturi pipe section 51 by the water guide pipe 53 for detection. The tip portions of the detection water conduits 52, 53 have the above-described configuration and are covered by the strainer 28.

A spring support base 47 of a water pressure adjusting device 46 is fixed to the upstream end of the small cylinder 24a of the pilot valve 24, and a spring 49 is provided between the small piston rod 24b and a handle 48 which is fitted with a screw. Is installed. Then, a reading plate on a disc fixed to the outer circumference of the handle 48
A flow rate display plate 55 is provided adjacent to 54. Further, the lengths of the spring 49 and the flow rate display plate 55 are sufficiently large so that the reading error of the flow rate display plate 55 due to the movement of the small piston rod 24b accompanying the opening and closing of the needle valve 22 can be ignored.

Next, the operation will be described. Since the flow rate in the Venturi pipe portion 51 is proportional to the square of the water pressure difference between the upstream and the narrowed portion, if the flow rate is determined, the water pressure difference between the pair of water pressure detection devices 41 is determined. Further, since the pair of water pressure detection pieces 43 has the same size as the structure, the set pressure of the spring 49 is determined by multiplying the water pressure difference between the upstream and the narrowed portions by the area of the water pressure detection piece 43. Once the set pressure is determined, the length of the spring 49 and the position of the reading plate 54 are determined from the free length of the spring 49 and the spring constant. Therefore, since the scale of the flow rate display plate 55 can be easily marked in advance, the maximum flow rate can be set by turning the handle 48 and aligning the reading plate 54 with the scale of the flow rate display plate 55.

After the flow rate is set as described above, if the amount of water used in the downstream is equal to or less than the maximum flow rate, the force of the spring 49 is larger than the water pressure difference between the upstream and the narrowed portion. The small piston rod 24b is biased to the slit 24d side communicating with the upstream side of the cylinder 32a. As a result, the slit leading to the downstream side of the cylinder 32a
Since 24d is exposed in the air and water pressure does not act on the downstream surface of the piston 32b, the piston 32b and the housing 22a are moved to the maximum downstream, and the needle valve 22 is kept fully open.

Next, if the upstream water pressure becomes high or the downstream water pressure becomes low and the flow rate increases, the spring
The length of 49 is long enough so that when the maximum flow rate is slightly exceeded, the small piston rod 24b will
It moves to the slit 24d side communicating with the downstream side of a, and the slit 24d communicating with the upstream side of the cylinder 32a is exposed in the air,
Since the water pressure on the upstream side of the piston 32b of the opening / closing device 32 is released, the piston 32b and the housing 22a move upstream and the needle valve 22 closes. Since this operation is performed every time the water pressure difference between the upstream and the downstream becomes large, the flow rate does not exceed the maximum flow rate by a predetermined error or more, and the flow rate can be suppressed to be substantially constant.

Further, when the water pressure difference between the upstream and downstream sides becomes small and the flow rate becomes slightly smaller than the predetermined maximum flow rate, the small piston rod 24b is connected to the upstream side of the cylinder 32a.
The slit 24d that moves to the 24d side and communicates with the downstream side of the cylinder 32a is exposed in the air, and the water pressure on the downstream side of the cylinder 32a is released, so that the piston 32b and the housing 22a move downstream and the needle valve 22 opens. This operation is performed each time the water pressure difference between the upstream and the downstream decreases, and finally the fully opened state described at the beginning is obtained.

[0045]

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to reliably operate the needle valve by using the pilot valve utilizing the atmosphere, and to realize the needle valve with a small head loss in the pipe channel. Can be used. Further, when the needle valve is in the equilibrium state, there is almost no discharge of the running water, so there is an effect that it is economical and the influence of dust is small. Further, since the running water in the pipe water channel can be operated by the control device without any unmanned power and can be utilized as a pressure reducing valve, a safety valve, a constant flow valve, etc., its effect is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part of a water control device using a needle valve according to an embodiment of the present invention.

FIG. 2 is a side view of a water pipe tip portion used in the water control apparatus of the embodiment.

FIG. 3 is a cross-sectional view showing a housing front portion of a needle valve used in the water control system of the embodiment.

FIG. 4 is a configuration diagram in the case where the water control device of the embodiment is used as a pressure reducing valve that keeps a downstream water pressure constant.

FIG. 5 is a configuration diagram when the water control device of the embodiment is used as a constant flow valve.

FIG. 6 is a cross-sectional view of a pressure reducing valve used in a conventional pipe channel.

FIG. 7 is a sectional view of a pressure reducing valve using a conventional needle valve.

FIG. 8 is a configuration diagram of a conventional water control device used for a farm pond or the like.

[Explanation of symbols]

 22 Needle valve 22a Housing 22b Needle body 23 Water distribution pipe 24 Pilot valve 24a Small cylinder 24b Small piston rod 24c Small piston 24d Slit 24e Joining chamber 26 Water conduit 27 Ring 28 Strainer 30 Controller 31 Water conduit 32 Switchgear 32a Cylinder 32b Piston 32c Piston rod 36 Support member 42 Water pressure detection chamber 43 Water pressure detection piece 49 Spring 51 Benryuri pipe section

Claims (4)

[Claims] 1. A needle valve in which a needle main body is fixed between water pipes divided upstream and downstream via a support member, and a housing which covers the needle main body is slidably provided on the water pipes upstream and downstream. , A pair of small pistons slidably fitted in a small piston rod are fitted in the small cylinder, and a pair of slits formed around the small cylinder in the vicinity of the inside of the pair of small pistons. And a pilot valve provided with a pair of joining chambers surrounding the outer circumference, and the inside of the water distribution pipe upstream of the needle valve and the inside of a small cylinder inside the pair of small pistons of the pilot valve are connected by a water guiding pipe, A control device for operating the small piston rod is provided, and the pair of joining chambers and the upstream side and the downstream side of the cylinder of an opening / closing device having a cylinder divided into an upstream side and a downstream side by a piston, respectively. Communicated by the water pipe, the pipe water channel system water system, wherein a and accommodated a piston in the cylinder and the housing of the needle valve attached through the piston rod of the switchgear. 2. A water pressure detecting chamber communicating with the inside of a water pipe downstream or upstream of the needle valve is arranged, and a water pressure detecting piece and a spring, which are mounted on the water pressure detecting chamber and are composed of a diaphragm or a piston, and a spring, and a small piston rod of the pilot valve. The water control device for a pipe waterway according to claim 1, further comprising a control device configured to be connected to the small piston rod according to a moving direction of the pipe. 3. The water distribution pipe is provided with a Benlyuri pipe section narrowed from the water distribution pipe, and a water pressure detection chamber communicating with the Benlyuri pipe unit and an upstream water distribution pipe of the Benlyuri pipe unit is provided, and each water pressure detection chamber is provided. A control device is provided, in which each of the water pressure detection pieces including a diaphragm or a piston and a spring attached to the small piston rod of the pilot valve are connected to the small piston rod according to the moving direction of the pilot valve. Item 1. A water control device for a pipe channel according to item 1. 4. The tip of a water conduit inserted into a water distribution pipe is formed parallel to the water flow, and the parallel tip is closed at its tip to form a plurality of water inlets on the outer circumference. 4. A pipe waterway according to claim 1, wherein the ring is fixed and a cloth strainer is stretched around the ring with the upstream end and the downstream end being tightly bound to the front end of the water guide pipe. Water control device.