JP2023057190A - Water level sensor installation structure - Google Patents

Abstract

To provide a water level sensor installation structure that enables improved detection accuracy of a water level sensor.SOLUTION: A water level sensor installation structure 60 includes: a water level sensor 50 including a sensor part 54 and a vertically cylindrical cabinet 52 storing the sensor part; a protection cylinder 62 that includes a plurality of holes 70a penetrating it in a thickness direction, and stands erect on a field 100 with its bottom buried in it, so as to surround the cabinet; and an installation table 64 including a sensor holder to hold the cabinet.SELECTED DRAWING: Figure 4

Description

There is an application for the application of Article 30, Paragraph 2 of the Patent Act Explanatory meeting for trial installation (Hokuriku Agricultural Administration Bureau, Sekikawa Water Supply Office) February 16, 2021 [Publications] Explanatory meeting for users of trial installation (Niigata Prefecture) Joetsu City) Held on March 1, 2021 [Publications, etc.] Installed on April 26, 2021 in Joetsu City, Niigata Prefecture

TECHNICAL FIELD The present invention relates to a water level sensor installation structure, and more particularly to a water level sensor installation structure for detecting the water level of a field.

An example of a conventional installation structure of this type of water level sensor is disclosed in Patent Document 1. In the technique of Patent Document 1, a single pipe (a rod-shaped fixture) is pierced into a field, and a housing of a water level sensor (sensor terminal) is connected and fixed to the single pipe using a universal clamp or the like. A sensor is erected in the field.

Japanese Patent Application Laid-Open No. 2020-103099

In the technique of Patent Document 1, there are cases where the reading of the water level sensor oscillates due to the influence of waves generated in the water when water is supplied from a hydrant or during strong winds, making it impossible to accurately measure (detect) the water level in the field. there were. In addition, since the water level sensor is thrust into the field, soil may enter the housing of the water level sensor and adhere to the sensor, resulting in erroneous measurement.

SUMMARY OF THE INVENTION Therefore, a primary object of the present invention is to provide a novel water level sensor installation structure.

Another object of the present invention is to provide a water level sensor installation structure capable of enhancing the detection accuracy of the water level sensor.

A first invention is an installation structure for a water level sensor for detecting the water level of a field, the water level sensor comprising a sensor section for detecting the water level of the field, and a vertical cylindrical housing for housing the sensor section, and a thickness direction of the water level sensor. A water level sensor, comprising: a protective cylinder having a plurality of holes penetrating through the body, and erected with its lower end buried in the field so as to surround the housing; installation structure.

In the first invention, the installation structure for the water level sensor includes the water level sensor, the protection tube and the installation base. The water level sensor includes a sensor section that detects the water level of the field, and a vertically cylindrical housing that houses the sensor section. Further, the protection tube is erected in the field by embedding the lower end portion in the field, and is provided so as to surround the casing of the water level sensor. A plurality of holes are formed through the protection cylinder in the thickness direction, and these holes are used as inlets and outlets for water. Also, the installation table has a sensor holder that holds the housing.

According to the first aspect of the invention, since the water level sensor is surrounded by the protective cylinder, the water level sensor is less susceptible to the effects of waves generated during water supply and strong wind, and the reading of the water level sensor can be stabilized. . Moreover, by surrounding the water level sensor with the protection tube and holding it with the installation table, the water level sensor is prevented from being buried in the soil, and erroneous measurement due to the soil adhering to the sensor section can be prevented. Therefore, the detection accuracy of the water level sensor can be enhanced.

A second invention is according to the first invention, and a lower end portion of the housing is detachably fitted into the sensor holding portion.

According to the second invention, the water level sensor can be installed accurately only by fitting the lower end portion of the housing into the sensor holding portion. In other words, installation of the water level sensor is facilitated, and installation accuracy of the water level sensor can be enhanced. Further, the water level sensor can be removed simply by pulling out the lower end portion of the housing from the sensor holding portion. In other words, it becomes easy to remove the water level sensor.

A third invention is according to the second invention, and the protection tube is formed in a bottomed tube shape having a side wall and a bottom wall. Also, the installation table is attached to the bottom wall.

A fourth invention is according to the second or third invention, and the installation table is provided so as to be able to adjust the height position of the sensor holder.

According to the fourth invention, the water level sensor can be installed more accurately.

A fifth invention is according to any one of the second to fourth inventions, and is provided so as to connect the upper end portion of the protective cylinder and the upper end portion of the housing, and prevents lateral displacement of the housing with respect to the protective cylinder. A positioning member is further provided.

According to the fifth aspect of the present invention, it is possible to reliably prevent lateral deviation (inclination) of the upper end portion of the water level sensor, so that installation accuracy and detection accuracy of the water level sensor can be further enhanced.

A sixth invention is according to the first invention, wherein the installation table has a sensor holding portion that holds the upper end of the housing, and a connecting portion that connects the sensor holding portion and the upper end of the protection cylinder.

A seventh invention is according to any one of the first to sixth inventions, and further includes a mud-blocking filter provided on the inner peripheral surface of the protective cylinder for preventing mud from entering the protective cylinder through a plurality of holes. Prepare.

According to the seventh aspect of the invention, it is possible to prevent mud from entering the protective tube, thereby preventing erroneous measurement due to mud adhering to the sensor portion of the water level sensor.

An eighth invention is according to any one of the first to seventh inventions, and further includes an anchor projecting outward from the protection tube.

According to the eighth aspect of the invention, even when the protective tube is installed upright in a soft field, it is possible to prevent the protective tube from floating and tilting, etc., and the installation accuracy of the protective tube (and thus the water level sensor) to the field can be improved. can improve.

A ninth invention is according to any one of the first to eighth inventions, and further includes a cover that covers an upper opening of the protection cylinder.

According to the ninth invention, even if foreign matter such as cut grass and soil scatter due to weeding and tilling, the scattered foreign matter is prevented from entering the protective cylinder. Therefore, it is possible to prevent erroneous measurement due to foreign matter such as cut grass and soil adhering to the sensor portion of the water level sensor, and to further improve the detection accuracy of the water level sensor.

A tenth invention is according to any one of the first to ninth inventions, and the farm field includes a farm field extension section provided on a ridge that divides the farm field. And the installation structure of this water level sensor is provided in the agricultural field expansion part.

According to the tenth invention, since the water level sensor is less susceptible to water level fluctuations during water supply, the detection accuracy of the water level sensor can be further enhanced. In addition, since the installation state of the protection tube and installation stand is stable, even if the water level sensor is removed and reinstalled during off-seasons for agriculture, the water level sensor can be installed at the same position more accurately. Furthermore, since the water level sensor does not protrude into the cultivated area of the field, the water level sensor and the like are less likely to interfere with agricultural work.

According to the present invention, it is less likely to be affected by waves generated during water supply or strong wind, and erroneous measurement due to soil adhering to the sensor section can be prevented, so the detection accuracy of the water level sensor can be improved. can.

The above object, other objects, features and advantages of the present invention will become more apparent from the detailed description of embodiments given below with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is an illustration figure which shows the agricultural field water management system to which the installation structure of the water level sensor which is one Example of this invention is applied. It is a sectional view showing an internal structure of an electric actuator. It is an illustration figure which shows a water level sensor. It is sectional drawing which shows the installation structure of a water level sensor. FIG. 4 is a cross-sectional view showing a protection cylinder and an installation base; It is a perspective view which shows the external appearance of a protection cylinder. FIG. 5 is a cross-sectional view showing an installation structure of a water level sensor according to another embodiment of the present invention; FIG. 5 is a cross-sectional view showing an installation structure of a water level sensor according to still another embodiment of the present invention; FIG. 5 is a cross-sectional view showing an installation structure of a water level sensor according to still another embodiment of the present invention;

Referring to FIG. 1, a water level sensor installation structure 60 (hereinafter simply referred to as "installation structure 60") according to one embodiment of the present invention includes a field water management system 10 (hereinafter simply referred to as "system 10"). ), it is applied when the water level sensor 50 is installed. As will be described later in detail, this installation structure 60 includes a water level sensor 50 that detects the water level of the field 100. The water level sensor 50 is surrounded by a protection tube 62 and held by an installation base 64, thereby preventing the water level sensor 50 from It improves detection accuracy.

First, prior to specific description of the installation structure 60, an example of the configuration of the system 10 will be briefly described. However, the configuration of the system 10 (the configuration of the water tap 12, the water outlet 14, the electric actuator 16, etc.) is not limited to this, and can be changed as appropriate.

As shown in FIG. 1, the system 10 is field equipment that performs water management in a field 100 by remote control or automatic control based on a pre-stored program. In this embodiment, system 10 includes a water tap 12 and a water outlet 14, each of which has an electric actuator 16 attached thereto. In other words, the electric actuator 16 having the same structure is used as the electric actuator for driving the displacement mechanisms of the water tap 12 and the water outlet 14 .

Moreover, in this embodiment, the system 10 is a system including a plurality of cultivated plots partitioned by ridges 102 . Each of the water tap 12 and the water outlet 14 is installed in each cultivated area, and each electric actuator 16 attached to these is connected to a repeater (master unit) by a wireless communication method according to the specified low-power wireless standard (920 MHz band). ) for wireless communication. Each electric actuator 16 is connected to a remote control terminal such as a smartphone, tablet terminal, PDA, or PC owned by the user so as to be able to communicate wirelessly via this repeater and a management server provided on the network. be done. However, the electric actuator 16 may wirelessly communicate with an external device such as a management server or a remote control terminal without using a repeater.

Note that cloud computing may be used in this wireless communication. For example, information acquired by each electric actuator 16 (information related to the state of the water tap 12 and the water outlet 14, such as the valve opening degree of the water tap 12 and the height of the water outlet 14, and the information received from the water level sensor 50 100 sensor information such as water level) is transmitted to a cloud server, which is an example of a management server, and stored. The user accesses the cloud server from the remote control terminal to check the information acquired by each electric actuator 16, and remotely controls each electric actuator 16 using the remote control terminal to perform water management for the field 100. It can be performed.

The water tap 12 is a water supply device for controlling water supply from the water pipeline 106 to the cultivated area (field 100), and has a displacement mechanism including a valve shaft and a valve body. In this embodiment, a widely used water tap 12 is used in which the valve shaft and the valve body move up and down as the valve shaft rotates. Such a water tap 12 is arranged in a water supply pit 104 provided in the ridge 102, and is downstream of a branch pipe 108 that branches from a water pipeline 106 laid under the ridge 102 and extends into the field 100. Attached to the side edge. An electric actuator 16 is attached to the water faucet 12 , and the electric actuator 16 operates a displacement mechanism (valve shaft and valve body) of the water faucet 12 .

On the other hand, the drain port 14 is a drainage device for controlling drainage from the field 100, and has a displacement mechanism including a partition and the like. In this embodiment, a water fall port 14 having a water level setting function is used. Briefly, the water outlet 14 has a cylindrical partition 18 whose upper end opening functions as a drain port, and the partition 18 moves up and down to adjust the drain port to an arbitrary height. Is possible. Such a water outlet 14 is arranged in a drainage basin 110 provided in the ridge 102 and attached to the upstream end of a drainage pipe 114 extending to the drainage channel 112 . An electric actuator 16 is attached to the water outlet 14 , and the displacement mechanism (partition) of the water outlet 14 is vertically moved by the electric actuator 16 . However, when the electric actuator 16 is attached to the water outlet 14, the adapter 20 is capable of converting the rotational force of the rotating shaft 46 (see FIG. 2) of the electric actuator into vertical (axial) force and transmitting it to the partition. is used.

Referring to FIG. 2 together with FIG. 1, the electric actuator 16 includes a cylindrical body case 30. As shown in FIG. A solar cell panel 32 is detachably attached on the body case 30 . The solar cell panel 32 is supported at a predetermined angle by a bent plate-shaped metal holder 34 .

Further, inside the body case 30, an electronic board 36, a storage battery 38, and a driving mechanism including a motor 40, a main gear 42, and the like are housed.

Although not shown, the electronic board 36 is provided with a control section including a CPU, a memory, and the like, a wireless communication section including a wireless communication module, and the like. The control unit is electrically connected to the motor 40, the operation panel 48, the wireless communication unit, the water level sensor 50, and the like. The CPU of the control unit manages the overall control of the electric actuator 16 and controls the driving of the motor 40 and the like. The memory comprehensively indicates ROM, RAM, HDD, etc., and stores a control program for controlling the operation of the electric actuator 16, and functions as a work area when the CPU operates. Also, the wireless communication unit is connected to an antenna (not shown), and wirelessly communicates with an external device such as a repeater via this antenna.

The storage battery 38 stores electric power generated by the solar panel 32 . Motor 40 is driven by electric power stored in storage battery 38 . A small gear 44 is provided at the tip of the output shaft 40a of the motor 40, and the main gear 42 is connected to the small gear 44 to receive driving force from the motor 40 and rotate around the axis. Rotate.

The main gear 42 is a double-boss type gear, and a substantially cylindrical rotating shaft 46 is inserted through the shaft portion of the main gear 42 . A coupling portion 46 a that is connected to the valve shaft of the water tap 12 is formed at the lower end portion of the rotating shaft 46 . A key groove 42a extending in the axial direction is formed on the inner peripheral surface of the shaft portion of the main gear 42, and a sliding key 46b fitted in the key groove 42a is formed on the outer peripheral surface of the rotating shaft 46. It is formed so as to extend along the direction. As a result, the rotation shaft 46 rotates together with the rotation of the main gear 42 and is slidable in the axial direction with respect to the shaft portion of the main gear 42 .

An operation panel 48 for manually (electrically) operating the motor 40 is provided on the outer surface of the main body case 30 . The operation panel 48 is appropriately provided with a main power switch, an up button, a down button, and a selection button for switching the operation mode (remote mode, automatic mode, manual mode, etc.) of the electric actuator 16 . The operation panel 48 is also provided with connection terminals and the like for connecting wiring 58 extending from the water level sensor 50 .

In the water faucet 12 to which the electric actuator 16 as described above is attached, for example, the user accesses the management server using a remote control terminal, and the water faucet 12 is fully closed, fully opened, or opened to an arbitrary degree. When an operation instruction (control signal) is transmitted, a control signal corresponding to this operation instruction is transmitted from the management server to the electric actuator 16 via the relay machine. The controller of the electric actuator 16 drives the motor 40 according to the received control signal. The driving force of the motor 40 is transmitted to the main gear 42, and the rotating shaft 46 rotates together with the main gear 42. As shown in FIG. Thereby, a rotational force is applied to the valve shaft of the water tap 12 fixedly connected to the rotating shaft 46 . The valve shaft to which the rotational force is applied is moved up and down by the feed screw mechanism, and the valve body is moved to a fully open position, a fully closed position, and the like.

Similarly, in the water outlet 14 to which the electric actuator 16 is attached, when the user transmits an operation instruction for setting the height of the water outlet 14 (the height position of the partition 18), the electric actuator 16 is controlled. The section drives the motor 40 in accordance with the control signal to change the height of the water outlet 14 .

Returning to FIG. 1 , the field 100 is provided with a water level sensor 50 (sensor terminal) in the vicinity of the water tap 12 and the water outlet 14 . As the water level sensor 50, for example, it is preferable to use a sensor that measures the field water level using changes in the capacitance or pressure of service water (field water).

Briefly, as shown in FIG. 3, the water level sensor 50 has a vertical cylindrical housing 52 made of synthetic resin such as rigid vinyl chloride. The nominal diameter (inner diameter) of the housing 52 is, for example, 40 mm. A sensor unit 54 (sensor substrate) for detecting the water level of the field 100 is accommodated in the housing 52 in a state of being fixed by screws or the like. A slit 52a serving as an inlet/outlet for water is formed in the lower end of the housing 52 so as to extend in the vertical direction. In addition, an annular mark line 52b is provided on the outer peripheral surface of the lower end of the housing 52, and when installing the water level sensor 50, the height position of this mark line 52b and the height of the upper surface (field surface) of the field 100 aligned with the position. Furthermore, a cap 56 (see FIG. 4) is provided at the upper end of the housing 52 to seal the upper end opening of the housing 52 .

Although not shown, the field 100 includes a water temperature sensor that detects the temperature of water, an air temperature sensor that detects air temperature, a humidity sensor that detects humidity, a pressure sensor that detects air pressure, and a soil moisture sensor that detects soil moisture. A sensor, such as a soil temperature sensor that detects the temperature of the soil, may be provided as appropriate. As the water level sensor 50 of this embodiment, a water level and water temperature sensor capable of detecting not only the water level of the field 100 but also the water temperature is used.

Such a water level sensor 50 is connected to the electronic board 36 of the electric actuator 16 by wiring 58 (signal cable) conforming to the RS-485 standard, for example. Sensor information regarding the water level and water temperature detected by the water level sensor 50 is input to the electronic board 36 of the electric actuator 16 . Electric power stored in the storage battery 38 of the electric actuator 16 is used as a power source for operating the sensor portion 54 of the water level sensor 50 , and this electric power is supplied from the electronic board 36 to the water level sensor 50 . By using the solar panel 32 and the storage battery 38 included in the electric actuator 16 as the power source for the water level sensor 50, there is no need to separately provide a power source such as a dry battery for the water level sensor 50, eliminating the need for battery replacement.

Here, since the water level sensor 50 is connected to the electric actuator 16 by the wiring 58 as described above, it is preferable to install the water level sensor 50 near the electric actuator 16 . However, if the water level sensor 50 is installed near the water tap 12, the reading of the water level sensor 50 may oscillate due to waves generated during water supply, and the water level of the field 100 may not be detected accurately. The same can be said for waves generated during strong winds. In addition, soil may enter the housing 52 through the slit 52a and adhere to the sensor unit 54, resulting in erroneous measurement of the water level. Furthermore, since the water level sensor 50 is installed in unstable soil, there is also a demand for increasing the installation accuracy of the water level sensor 50 .

Therefore, in this embodiment, the detection accuracy of the water level sensor 50 is improved by adopting the installation structure 60 described below. The configuration of the installation structure 60 will be specifically described below with reference to FIGS. 4 to 6. FIG.

As shown in FIG. 4 , the installation structure 60 includes a water level sensor 50 , a protection cylinder 62 erected in the field 100 so as to surround the water level sensor 50 , and a protection cylinder 62 provided in the protection cylinder 62 to hold the water level sensor 50 . An installation table 64 is provided.

As shown in FIGS. 4 to 6, the protection tube 62 is formed in a bottomed tube shape having a cylindrical side wall 70 and a disk-shaped bottom wall 72, and the lower end portion is embedded in the field 100, thereby 100. A plurality of holes 70a penetrating in the thickness direction are formed in the side wall 70 and the bottom wall 72 of the protective cylinder 62, distributed over the entire tube wall. A plurality of holes 70a are used as inlets and outlets for water. The diameter of hole 70a is, for example, 3 mm to 20 mm. Furthermore, the bottom wall 72 is formed with a plurality of insertion holes (not shown) for inserting bolts 82a, which will be described later, so as to be arranged at predetermined intervals in the circumferential direction. Moreover, an annular marked line 70 b is provided on the outer peripheral surface of the side wall 70 . This marked line 70b is provided at the same height position as the marked line 52b of the water level sensor 50 installed on the installation table 64, and when the protective cylinder 62 is erected in the field 100, the marked line 70b The height position and the height position of the upper surface of the field 100 are matched.

The nominal diameter of the protection tube 62 is not particularly limited as long as it is a size that allows the housing 52 of the water level sensor 50 to be inserted thereinto, but is set to 150 mm to 200 mm, for example. In addition, the height dimension (axial length) of the protection tube 62 is set so that the upper end surface of the protection tube 62 is at a height position equal to or slightly higher than the maximum water level of the irrigation water stored in the field 100. For example, It is set to 350-450mm. In this embodiment, the upper end of the water level sensor 50 protrudes above the upper end surface of the protective cylinder 62, but the upper end surface of the protective cylinder 62 is at the same height position or water level as the upper end surface of the water level sensor 50 or the water level. It may be located above the upper end surface of the sensor 50 . In addition, the axial length of the portion below the marked line 70b of the protective cylinder 62 (the portion buried in the field 100) is set to, for example, 100 mm to 200 mm so that the protective cylinder 62 can be firmly fixed to the agricultural field 100. .

Such a protection tube 62 can be formed, for example, by bonding a perforated pipe made of synthetic resin such as rigid polyvinyl chloride or polyethylene and a short cylindrical cap member with a bottom by adhesive bonding. However, the perforated pipe and the cap member may simply be detachably fitted together. That is, the side walls 70 may be detachably connected to the bottom wall 72 . The size, shape and material of the protection tube 62 are not particularly limited as long as they can be erected to cover the periphery of the water level sensor 50 and have a predetermined strength to withstand strong winds.

An anchor 74 projecting outward is provided at the lower end of the protection cylinder 62 . The anchor 74 is provided, for example, by fixing a stainless steel angle member to the lower end portion of the outer surface of the protection cylinder 62 using a fastening member such as a bolt. By providing such an anchor 74 to the protective cylinder 62, even when the protective cylinder 62 is erected in a soft field 100, the protective cylinder 62 can be prevented from floating and tilting, etc., and the field 100 can be protected. Installation accuracy of the tube 62 (and thus the water level sensor 50) can be improved.

As shown in FIGS. 4 and 5 , the installation table 64 has a sensor holding portion 76 that holds the housing 52 of the water level sensor 50 and is attached to the bottom wall 72 of the protection tube 62 . In this embodiment, the sensor holding portion 76 is formed in the shape of a short cylinder, and the lower end portion of the sensor holding portion 76 is formed with an inwardly protruding annular projection-shaped engaging portion 76a. The inner diameter of the sensor holding portion 76 is set to be substantially the same as the outer diameter of the housing 52 so that the housing 52 can be attached and detached without tilting. be. In addition, the axial length of the portion above the locking portion 76a of the sensor holding portion 76 is set to, for example, 40 mm to 70 mm so that the mounted housing 52 does not tilt.

Further, the mounting base 64 is formed with a brim-shaped fixing portion 80 projecting outward from the lower end portion of the sensor holding portion 76 . A plurality of insertion holes (not shown) for inserting bolts 82a, which will be described later, are formed in the fixing portion 80 so as to be arranged at predetermined intervals in the circumferential direction.

Fastening members such as bolts 82a and nuts 82b are used to attach the mounting base 64 to the bottom wall 72 of the protection tube 62. As shown in FIG. That is, by inserting a bolt 82a through an insertion hole formed in the bottom wall 72 of the protection tube 62 and the fixing portion 80 of the installation table 64 and tightening it with a nut 82b, the installation table 64 is attached to the bottom wall 72 of the protection tube 62. fixed. At this time, a cylindrical spacer 84 having a predetermined axial length is fitted onto the bolt 82a. By changing the axial length of the spacer 84, the height position of the sensor holding portion 76 can be adjusted. That is, the installation table 64 is provided so that the height position of the sensor holding portion 76 can be adjusted.

The lower end of the housing 52 is detachably fitted into the sensor holding portion 76, and the lower end of the housing 52 is locked by the locking portion 76a. maintained in state. When attaching the installation base 64 to the protection cylinder 62, the water level sensor 50 is temporarily attached to the sensor holding part 76, and the height position of the marked line 52b of the water level sensor 50 and the height of the marked line 70b of the protective cylinder 62 It is preferable to adjust the height position of the sensor holding portion 76 so that it matches the height position. As a result, the water level sensor 50 can be installed simply by fitting the lower end of the housing 52 into the sensor holding portion 76 of the installation table 64 after the protective tube 62 to which the installation table 64 is attached is erected in the field 100 . complete.

In such an installation structure 60, the surroundings of the water level sensor 50 are covered by the protective cylinder 62, so that waves generated during water supply and strong wind can be prevented from reaching the water level sensor 50 (that is, the water level fluctuates). can be mitigated), enabling accurate and stable water level measurement. In addition, the water level sensor 50 is held by the installation table 64, and the protective tube 62 prevents the lower end of the water level sensor 50 from being buried in the soil, so that the sensor section 54 is prevented from being erroneously measured due to the soil adhering to it. prevented. In particular, by raising the mounting base 64 from the bottom wall 72 of the protective cylinder 62 using the spacer 84 (that is, by keeping the lower end of the water level sensor 50 floating from the lower end of the protective cylinder 62), Even if foreign matter such as mud enters, the foreign matter accumulates on the bottom wall 72 and adversely affects the water level sensor 50 .

In addition, the protective tube 62 and the installation table 64 as described above are preferably installed permanently in the field 100 regardless of the season. On the other hand, the water level sensor 50 is preferably removed from the farm field 100 and stored in a storehouse or the like during off-seasons such as winter. Since the water level sensor 50 can be removed simply by pulling out the lower end portion from the sensor holding portion 76, the removal work can be easily performed. Also, once the protection tube 62 and the installation base 64 are firmly installed, the water level sensor 50 can be installed accurately at the same position simply by fitting the lower end of the housing 52 into the sensor holding portion 76 . That is, it is possible to easily perform the removal work and installation work of the water level sensor 50, and to improve the installation accuracy of the water level sensor 50 in the field 100 as well.

If the side wall 70 of the protection tube 62 is detachably connected to the bottom wall 72, the side wall 70 of the protection tube 62 is also removed from the field 100 and stored in a storage room or the like during the off-season such as winter. You can also keep it. In addition, when foreign matter accumulates on the bottom wall 72, the foreign matter on the bottom wall 72 can be easily removed by removing the side wall 70 portion.

As described above, according to this embodiment, since the water level sensor 50 is surrounded by the protective cylinder 62, the water level sensor 50 is less likely to be affected by waves generated during water supply and strong winds, and the sensor section 54 is protected. Reading stabilizes. In addition, by surrounding the water level sensor 50 with the protection tube 62 and holding it with the installation base 64, the water level sensor 50 is prevented from being buried in the soil, and erroneous measurement due to soil adhering to the sensor section 54 can be prevented. . Therefore, the detection accuracy of the water level sensor 50 can be improved.

In the above-described embodiment, a perforated pipe having a plurality of holes 70a distributed in the pipe wall is used as the side wall 70 of the protection tube 62. However, the shape, size, formation position and number of the holes 70a , can be changed as appropriate. For example, the side wall 70 of the protection tube 62 can be formed of a Netron (registered trademark) pipe having a mesh structure with numerous holes formed in the pipe wall.

Further, as in the embodiment shown in FIG. 7, a mud-blocking filter 90 can be provided on the inner surface side of the protective tube 62. As shown in FIG. The mud-shielding filter 90 has countless small holes smaller than the holes 70 a of the protection tube 62 , and is formed, for example, in a cylindrical shape so as to cover the inner peripheral surface of the side wall 70 . As the mud-shielding filter 90, it is preferable to use synthetic resin non-woven fabric or the like.

In this way, by providing the mud-blocking filter 90 on the inner peripheral surface of the side wall 70 of the protection tube 62, it is possible to prevent mud from entering the protection tube 62 through the hole 70a of the side wall 70. It is possible to prevent erroneous measurement due to mud adhering to the sensor section 54 . Therefore, the detection accuracy of the water level sensor 50 can be further improved. Further, if the mud-shielding filter 90 is detachable from the side wall 70 of the protective cylinder 62, when the mud-shielding filter 90 is clogged, the mud-shielding filter 90 can be removed from the protective cylinder 62 and washed. It becomes possible to use the mud-shielding filter 90 repeatedly many times.

7, illustration of the water level sensor 50 is omitted for the sake of clarity. In addition, the same reference numerals are given to the parts that are common to the above-described embodiment, and overlapping descriptions are omitted or simplified. Omitting redundant descriptions is the same for other embodiments described later.

Moreover, in the above-described embodiment, the lower end of the water level sensor 50 is simply held by the mounting table 64, but a positioning member 92 can be further provided as in the embodiment shown in FIG. The positioning member 92 is a member for restricting the lateral movement of the housing 52 of the water level sensor 50 and preventing the lateral displacement of the housing 52 with respect to the protection cylinder 62 . It is provided so as to connect the water level sensor 50 to the upper end of the housing 52 . For example, the positioning member 92 includes a ring-shaped holding portion 92 a that is externally fitted to the upper end of the housing 52 and a connecting portion 92 b that connects the holding portion 92 a and the upper end of the side wall 70 of the protection tube 62 . The end portion of the connecting portion 92b on the protection tube 62 side is fixed to the upper end portion of the side wall 70. As shown in FIG. The inner diameter of the holding portion 92a is preferably set substantially equal to the outer diameter of the housing 52 so that the housing 52 can be attached and detached in the axial direction. Accordingly, removal work and installation work of the water level sensor 50 can be easily performed by simply inserting and removing the water level sensor 50 from above the positioning member 92 to the holding part 92 a and the sensor holding part 76 of the installation base 64 .

In this way, by providing the positioning member 92 that connects the upper end of the protection tube 62 and the upper end of the water level sensor 50 and restricts the horizontal movement of the water level sensor 50, the water level sensor 50 can be prevented from moving even in strong winds. Since the lateral displacement (inclination) of the upper end is reliably prevented, the installation accuracy and detection accuracy of the water level sensor 50 can be further improved.

Although illustration is omitted, the holding portion 92a of the positioning member 92 can be formed so that its diameter can be reduced (clampable). For example, a notch may be formed in a portion of the holding portion 92a in the circumferential direction, and a configuration may be adopted in which the diameter of the holding portion 92a is reduced by tightening the tightening portion. As a result, the inner peripheral surface of the holding portion 92a and the outer peripheral surface of the housing 52 can be brought into close contact with each other by tightening the housing 52 by the holding portion 92a. Directional movement can also be controlled. Therefore, the water level sensor 50 can be appropriately positioned in the vertical direction (particularly, prevented from coming off), and the installation accuracy and detection accuracy of the water level sensor 50 can be further enhanced.

Furthermore, as in the embodiment shown in FIG. 8, a cover 94 may be provided to cover the upper opening of the protection tube 62. As shown in FIG. The cover 94 is, for example, tapered downward from the central portion toward the peripheral portion (that is, the diameter of the cover 94 decreases as it goes upward), and is placed on the protection tube 62 . In this embodiment, since the upper end of the water level sensor 50 protrudes above the upper end surface of the protection tube 62, an opening through which the water level sensor 50 is inserted is formed in the center of the cover 94.

By providing the cover 94 covering the upper opening of the protection tube 62 in this manner, even if foreign matter such as cut grass and soil scatters during weeding or tilling, the scattered foreign matter can be prevented from entering the protection tube 62. is prevented. Therefore, it is possible to prevent erroneous measurement due to foreign objects such as cut grass and soil adhering to the sensor portion 54 of the water level sensor 50, and the detection accuracy of the water level sensor 50 can be further improved. By forming the connecting portion 92b of the positioning member 92 in the shape of an annular plate, the positioning member 92 (connecting portion 92b) can also be used as a cover.

Further, in the above-described embodiment, as an example of the installation table, the installation table 64 that holds the lower end portion of the housing 52 of the water level sensor 50 was illustrated, but the mode of the installation table is not limited to this. For example, as in the embodiment shown in FIG. 9, a mounting base 96 that holds the upper end of the housing 52 may be used. Briefly, the installation table 96 includes a ring-shaped sensor holding portion 96 a fitted to the upper end portion of the housing 52 . The sensor holding portion 96a has a notch in a part in the circumferential direction, and can be reduced in diameter by tightening the tightening portion 96b. The installation base 96 also includes a connecting portion 96c that connects the sensor holding portion 96a and the upper end portion of the side wall 70 of the protective cylinder 62. The end portion of the connecting portion 96c on the side of the protective cylinder 62 fixed to Then, the upper end portion of the housing 52 of the water level sensor 50 is fitted into the sensor holding portion 96a, and the upper end portion of the housing 52 is tightened by the sensor holding portion 96a. The water level sensor 50 is held in an upright state by the installation base 96 by tightly contacting the outer peripheral surface of the

In the embodiment shown in FIG. 9 as well, the water level sensor 50 is surrounded by the protection tube 62 and held by the mounting table 96, as in the above-described embodiment, so the water level sensor 50 is generated during water supply and strong wind. Less susceptible to waves. Moreover, since the water level sensor 50 is prevented from being buried in the soil, erroneous measurement due to soil adhering to the sensor section 54 is prevented. Therefore, the detection accuracy of the water level sensor 50 can be improved.

In the embodiment shown in FIG. 9, the water level sensor 50 is held by tightening the upper end of the housing 52 with the sensor holding portion 96a. The water level sensor 50 can also be held by providing the protruding portion and engaging the upper end of the sensor holding portion 96a. Further, by forming the connection portion 96c of the installation table 96 in the shape of an annular plate, the installation table 96 (connection portion 96c) can also be used as a cover for covering the upper opening of the protection tube 62. FIG.

Furthermore, in the above-described embodiment, the installation structure 60 is provided within the cultivated area of the field 100 partitioned by the ridge 102, but the present invention is not limited to this. Although not shown, it is also possible to excavate the ridge 102 to provide a farm field expansion portion that communicates with the cultivated area of the farm field 100 in the ridge 102, and to provide the installation structure 60 in this farm field expansion portion.

By providing the installation structure 60 in the farm field extension part, it becomes less susceptible to water level fluctuations during water supply, and the detection accuracy of the water level sensor 50 can be further enhanced. In addition, since the installation state of the protection cylinder 62 and the installation bases 64, 96 is stable, the water level sensor 50 can be installed at the same position more accurately even if the water level sensor 50 is removed and re-installed during off-season. That is, the installation accuracy of the water level sensor 50 can be further improved, and the detection accuracy of the water level sensor 50 can be further improved. Furthermore, since the installation structure 60 does not protrude into the cultivated area of the field 100, it is less likely to interfere with farm work.

Furthermore, in the above-described embodiment, the installation table 64 is fixed to the bottom wall 72 of the protection tube 62, but the installation table 64 can be installed independently (separated) from the protection tube 62. For example, when the installation structure 60 is provided in the farm field extension section, the farm field extension section can be made of concrete or the like. Then, it is preferable to fix the installation table 64 to the concrete forming the farm field expansion portion without providing the bottom wall 72 to the protection tube 62 . By separating the protective tube 62 and the installation table 64, even if the protective tube 62 is hit by an agricultural machine or the like and the protective tube 62 tilts a little, the installation table 64 and the water level sensor 50 can be prevented from that situation. You can prevent it from being affected.

It should be noted that the specific numerical values such as the dimensions and the specific shapes given above are merely examples, and can be appropriately changed according to the needs such as the specifications of the product.

DESCRIPTION OF SYMBOLS 10...Field water management system 12...Water faucet 14...Water fall opening 16...Electric actuator 50...Water level sensor 52...Casing 54...Sensor part 60...Installation structure of water level sensor 62...Protective tube 64, 96...Installation stand 76...Sensor Holding part 90 Mud shield filter 92 Positioning member 94 Cover 100 Field

Claims (10)

An installation structure for a water level sensor that detects the water level of a field,
A water level sensor comprising a sensor unit for detecting the water level of the farm field and a vertical cylindrical housing that houses the sensor unit;
A protective tube having a plurality of holes penetrating in the thickness direction, the lower end of which is embedded in the field so as to surround the housing and is erected, and an installation table having a sensor holding portion that holds the housing. A water level sensor installation structure. 2. The water level sensor installation structure according to claim 1, wherein a lower end portion of said housing is detachably fitted into said sensor holding portion. The protection tube is formed in a bottomed tube shape having a side wall and a bottom wall,
3. The water level sensor installation structure according to claim 2, wherein said installation base is attached to said bottom wall. 4. The water level sensor installation structure according to claim 2, wherein said installation table is provided so as to be able to adjust the height position of said sensor holding portion. 5. The apparatus according to any one of claims 2 to 4, further comprising a positioning member provided so as to connect an upper end portion of said protection tube and an upper end portion of said housing and preventing lateral displacement of said housing with respect to said protection tube. installation structure of the water level sensor. 2. The installation base for the water level sensor according to claim 1, wherein said installation table has said sensor holding portion for holding an upper end portion of said housing, and a connecting portion for connecting said sensor holding portion and an upper end portion of said protective cylinder. structure. 7. The water level sensor installation structure according to any one of claims 1 to 6, further comprising a mud-blocking filter provided on the inner surface side of said protection tube for preventing mud from entering said protection tube through said plurality of holes. The installation structure of the water level sensor according to any one of claims 1 to 7, further comprising an anchor protruding outward from said protection tube. The water level sensor installation structure according to any one of claims 1 to 8, further comprising a cover that covers an upper opening of said protection cylinder. The farm field includes a farm field extension section provided on a ridge that divides the farm field,
The installation structure of the water level sensor according to any one of claims 1 to 9, wherein the installation structure of the water level sensor is provided in the agricultural field extension section.

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