JPH0448125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a water level control device for cultivated land using a pressure reducing valve for pressure-feeding water for irrigation in underground irrigated cultivated land.

``Conventional technology'' Conventionally, in cultivated fields using underground irrigation methods, irrigation water was supplied above and below the rice field through underground pipes, timbered culverts, and bullet culverts. Then, the underground pipe was connected to a water level control weir, and the water level in the cultivated land was controlled by raising and lowering the weir door (Japanese Patent Application Laid-Open No. 185214/1982).In addition, when supplying pressurized water to the underground pipe, a discharge water tank was used. A pressure reducing valve was installed in the water tank, and the opening and closing of the valve was adjusted by raising and lowering a float in the tank (Japanese Patent Application No. 60-90394 (Japanese Patent Application No. 61-250215)).
Japanese Patent Application No. 60-147019 (Japanese Unexamined Patent Publication No. 62-6618).
However, the response of the float and pressure reducing valve to fluctuations in the rice field water level is poor. Therefore, an invention was made to transport water from the water source to underground pipes with a pump, install a water level or moisture detector in the cultivated land, and maintain the water level by operating a valve, but this required power and a large amount of equipment (especially Hope
No. 60-59897 (Japanese Unexamined Patent Publication No. 61-219322)).

"Problems to be Solved by the Invention" The present invention uses a simple equipment for underground irrigation using pressurized water, does not require power, has good responsiveness to the water level of the cultivated land, and uses a highly safe pressure reducing valve. The purpose is to obtain a control device.

"Means for Solving the Problems" The present invention supplies irrigation water to cultivated land from underground pipes through bullet culverts and timbered culverts installed in the same,
In an underground irrigation system in which a pressure water pipe is opened upward in a water tank connected to the buried pipe and a pressure reducing valve is provided in the opening, the pressure reducing valve is fitted into the opening and has an upward cylindrical shape that can be raised and lowered. The valve and a downward valve seat fixed above the opening are facing each other so as to be openable and closable, and the upward cylindrical valve is connected via a rod to a float placed above the valve to raise and lower the water level of the water tank. The pressure reducing valve is closed and opened by the rise and fall of the float, and a cylinder is provided on the downward valve seat,
The lower piston chamber of the cylinder is communicated with the opening, the upper end of the piston rod is formed to push up the float through the rod, and the lower piston chamber and the upper chamber are connected by piping to form a three-way valve. The switching rod of the three-way valve is connected to the water level sensing float in the cultivated land, and when the sensing float rises, the three-way valve is switched and the communication between the upper and lower chambers is closed. At the same time, only the piping connected to the upper chamber is opened, and the lowering of the sensing float switches the three-way valve to communicate the upper chamber with the lower chamber. Ru.

``Function'' Therefore, the pressure water fed from the pressure water pipe 6 is discharged into the water tank 5 from between the downward cylindrical valve 9 and the downward valve seat 10, the water level rises, and the water is stored. At the same time, irrigation water 22 is supplied to the cultivated land 1 from the underground pipe 4 via the wood culvert 3 and the bullet culvert 2. Until the water level of the irrigation water 22 reaches a predetermined water level, the water level sensing float 20 is lowered, so the piston upper and lower chambers 14,1
Since the pipes 17 and 18 of 5 are opened and communicated in the three-way valve 19, the piston upper and lower chambers 14 and 15 are filled with pressurized water that entered from the opening 7, and the water pressure in the piston upper and lower chambers 14 and 15 is Since it becomes uniform, the piston 23 does not operate. When the predetermined water level is reached, the upward cylindrical valve 9 rises via the rods 12 and 20 due to the rise of the float 11 and the water level sensing float 21 in the water tank 5, and comes into contact with the downward valve seat 10 to open the pressure reducing valve. 8 is closed and the communication of the three-way valve 19 is closed, so the piping 17 connected to the piston upper chamber 14 is connected to the three-way valve 19.
The water pressure in the upper chamber 14 decreases, and the water pressure in the lower chamber 15 overcomes, raising the piston 23 and lifting the float 11 at the upper end of the piston rod 16, so that the upward cylindrical valve 9 also exerts an upward force. The opening 7 of the pressure water pipe 6 is connected to the pressure reducing valve 8.
is sufficiently occluded by When the water level in the cultivated land 1 falls, the sensing float 21 descends and connects the pipes 17 and 18 connected to the three-way valve 19. Therefore, the water pressure in the upper and lower piston chambers 14 and 15 is distributed at equal pressure, and the driving force of the piston 23 disappears. Then, since the float 11 in the water tank 5 also descends, the upward cylindrical valve 9 is lowered,
The predetermined water level can be maintained by repeating the operation of opening the pressure reducing valve 8 and releasing pressurized water from the opening 7 to raise the water level in the water tank 5 and the cultivated land 1 to a predetermined water level.

"Example" Multiple bullet culverts (woodless culverts) on cultivated land 1 such as rice fields
A deep timber culvert 3 (filled with rice husks, etc.) is provided to form the culvert 2 and communicate with the culvert 2 at right angles.
An underground pipe 4 is provided below, communicating with the pipe 4'. One end of this buried pipe 4 is connected to a discharge pipe 27 via a water tank 26 having a water level setting weir door 25 that can be raised and lowered, and the other end is connected to the lower part of the pressure water discharge water tank 5. As shown in Fig. 1, a pressure water pipe 6 is inserted into this water tank 5 and opened upward, and a pressure reducing valve 8 is provided in the opening 7, and a float 11 for opening and closing the valve 8 is provided underground. form an irrigation system; As shown in FIG. 2, the pressure reducing valve 8 faces an upward cylindrical valve 9 that fits into the opening 7 and is movable up and down, and a downward valve seat 10 fixed above the opening 7 so as to be openable and closable. Then, the upward cylindrical valve 9 and the float 11 are connected to the rod 1.
Connect by 2. An upright cylinder 13 is provided on the upper surface of the downward valve seat 10, and the lower chamber 15 of the piston 23 of the cylinder 13 is inserted into the opening 7 through the through hole 2.
8, the upper end of the piston rod 16 is in contact with the downward receiving surface 12' of the rod 12, and the float 1
1 is formed so as to push it up. The upper chamber 14 of the piston 23 is connected to the lower chamber 15 through piping 17, 18, and the tips of the piping 17, 18 are connected to two of the three-way valves 19.
Connecting to the inlets 17', 18' of the same inlet 17',
By opening 18', the pipes 17, 18 and the upper and lower chambers 1
4 and 15 are in communication with each other, and by closing the communication, the outlet 24 of the three-way valve 19 and the piston upper chamber 1 are connected.
This switching is performed by a lifting rod 20, and the water level sensing float 21 of the cultivated land 1 is connected to the same rod 20.
(Pilot float) is connected. This float 21
and the three-way valve 19 is an upright buried cylinder 2 with a hole shown in FIG.
The float 21 can be raised and lowered by changing the water level in the cylinder 29, and its rise closes the inlets 17' and 18', lowers the water pressure in the piston upper chamber 14, and lowers the water pressure in the lower chamber 15. The piston 23 is raised to raise the float 11 via the rod 12, the upward cylindrical valve 9 is raised, and the pressure reducing valve 8 is closed.
By communicating 8', the upper and lower piston chambers 1
4 and 15 and eliminate the sliding force of the piston 23, the float 11 also descends, lowers the upward cylindrical valve 9, and opens the pressure reducing valve 8 to open the pressure water pipe 6.
Pressure water is supplied from the opening 7 of the farmland 1, thereby increasing the water level on the farmland 1 side. The pilot valve (three-way valve 19 above) closes the pressure reducing valve 8 (main valve) at the upper limit set water level.
The lower limit set water level (the upper and lower limit width is approximately 5
cm), the main valve 8 can be opened, and the rice field reference water level can be easily changed from ±0 to -10 cm or -20 cm above the rice field. The number 30 in the figure is rod 1.
The spokes provided at the lower end of 2, 31 are the same spokes 3
0 and the upward cylindrical valve 9.

"Effect" Since the present invention is configured as described above, the three-way valve 19
The water level sensing float 21 serves as a pilot sensor for the water level in the cultivated land 1, and the piston rod 16 is used to control the float 11 by switching the three-way valve.
In order to push up the water level, the float 11 has a buoyant force based on the rise in the water level as well as the piston rod 1.
The pushing up force of 6 acts, which causes the pressure reducing valve 8 to
The responsiveness of the main valve by the float 11 can be improved, and therefore the water level setting range can be set within a small range, making it possible to perform water management according to the growth of crops. Furthermore, when the water level in the water tank 5 abnormally or suddenly rises above the water level in the cultivated land 1, the float 11 directly responds to close the pressure reducing valve 8, thereby preventing any influence on the rice field.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a cultivated land water level control device using a pressure reducing valve of the present invention, Fig. 2 is a vertical sectional view of the pressure reducing valve, Fig. 3 is a plan view of the same pressure reducing valve, and Fig. 4 is a state in which the above device is used. FIG. 1... Cultivated land, 2... Bullet culvert, 3... Material culvert, 4... Underground pipe, 5... Water tank, 6... Pressure water pipe, 7... Opening, 8... Pressure reducing valve, 9... ...Upward cylindrical valve, 10...Downward valve seat, 11...Float, 12
... Rod, 13 ... Cylinder, 14 ... Piston upper chamber, 15 ... Piston lower chamber, 16 ... Piston rod, 17, 18 ... Piping, 19 ... 3-way valve, 20 ... Lifting rod for switching, 21...Float for sensing water level.

Claims (1)

[Claims] 1. Irrigation water is supplied to the cultivated land from underground pipes through bullet culverts and material underdrains installed in the cultivated land, and a pressure water pipe is opened upward in the water tank connected to the buried pipe, and a pressure reducing valve is installed in the opening. In the underground irrigation system, the pressure reducing valve has an upward cylindrical valve that fits in the opening that can be raised and lowered, and a downward valve seat that is fixed above the opening, facing each other so as to be openable and closable; A cylindrical valve is connected to a float disposed above it via a rod, and the float is raised based on the rise and fall of the water level in the water tank;
The pressure reducing valve is closed and opened by descending, and a cylinder is provided on the downward valve seat, and a lower chamber of the piston of the cylinder is communicated with the opening,
The upper end of the piston rod is formed to push up the float through the rod, and the piston lower chamber and the upper chamber are connected via a three-way valve via piping, and an elevating rod for switching the three-way valve is provided. is connected to a float for sensing the water level of the cultivated land, and as the sensing float rises, the three-way valve is switched to close communication between the upper chamber and the lower chamber, and only the piping connected to the upper chamber is opened;
A cultivated land water level control device using a pressure reducing valve, which switches the three-way valve as the sensing float descends to communicate the upper chamber and the lower chamber.