Electric actuator

Abstract

To provide an electric actuator that allows easy manual operation of a water supply control device in emergencies and the like.SOLUTION: An electric actuator 16 includes an actuator body 40 and a mounting section 42. The actuator body can be switched between a fixed state, where it is non-rotatably secured to the mounting section, and a rotatable state, where it can rotate 360 degrees or more around the mounting section in the circumferential direction. In the rotatable state, the actuator body can rotate around the mounting section in the circumferential direction while being prevented by a guide bolt 82 from detachment from the mounting section in the vertical direction.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an electric actuator, and more particularly to an electric actuator that is attached to a water supply control device that has a displacement mechanism for controlling the supply of water to or drainage from a farm field, for example, and operates the displacement mechanism. [Background technology]

[0002] An example of a water supply control device equipped with a conventional electric actuator is disclosed in Patent Document 1. With the technology of Patent Document 1, by attaching an electric actuator to a water supply control device such as a water faucet or a water outlet to drive the device, it is possible to perform irrigation management of a farm field by remote control or automatic control. When attaching the electric actuator to the water supply control device, the valve shaft (or connecting shaft) of the water supply control device and the rotating shaft of the electric actuator are connected.

[0003] Another example of a conventional electric actuator is disclosed in Patent Document 2. The electric actuator in Patent Document 2 is an electric valve actuator that is attached to the input side of a reducer that drives a part-turn valve, and reduces the rotation of a motor by a worm and a worm wheel to drive the reducer. In this electric actuator, a drive sleeve is provided inside the worm wheel, and an output shaft that is connected to the reducer is provided inside the drive sleeve. In addition, one end of a clutch is provided on the drive sleeve or the output shaft, and a manual handle is provided on the other end of the clutch. The clutch is disengaged when the motor is started, and is engaged when the motor is stopped, so that the valve can be opened and closed simply by rotating the manual handle when the motor is stopped. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-103099 A [Patent Document 2] JP 2016-160969 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the event of a breakdown in the electric actuator, it becomes necessary to manually displace (open / close) the displacement mechanism of the water supply control device. With the technology of Patent Document 1, when manually operating the water supply control device, it is necessary to disconnect the valve shaft (or connecting shaft) of the water supply control device from the rotating shaft of the electric actuator, and then attach a handle to the valve shaft and turn it, which makes manual operation time-consuming.

[0006] On the other hand, the technology of Patent Document 2 requires a clutch mechanism for disconnecting the motor shaft and a mechanism for transmitting the rotation of the manual handle to the rotating shaft of the electric actuator, which makes the structure of the electric actuator complex. The more complex the structure, the larger the electric actuator becomes, and the higher the price becomes.

[0007] SUMMARY OF THE PRESENT EMBODIMENTS Therefore, a primary object of the present invention is to provide a novel electric actuator.

[0008] Another object of the present invention is to provide an electric actuator that enables easy manual operation of a water supply control device in an emergency or the like. [Means for solving the problem]

[0009] A first invention is an electric actuator that is attached to a water supply control device having a displacement mechanism for controlling water supply to or drainage from a farm field, and operates the displacement mechanism, the actuator comprising: an actuator body having a drive mechanism for driving the displacement mechanism and a main body case for accommodating the drive mechanism; and an attachment portion for attaching the actuator body to the water supply control device, the main body case having a first bolt hole formed in a lower end portion of the main body case and a second bolt hole formed in the lower end portion of the main body case at a height position different from that of the first bolt hole, the attachment portion having a side wall portion fitted with the lower end portion of the main body case, a side wall portion fitted with the lower end portion of the main body case, and a bolt hole formed in the side wall at a position corresponding to the first bolt hole. the side wall portion has a through hole formed in the first bolt hole and a ring-shaped guide groove formed in the side wall portion at a position corresponding to the second bolt hole and extending in the circumferential direction of the side wall portion, the actuator body being switchable between a fixed state in which the actuator body is fixed non-rotatably with respect to the mounting portion and a rotatable state in which the actuator body can rotate 360 ​​degrees or more in the circumferential direction relative to the mounting portion in the rotatable state, and is rotatable in the circumferential direction relative to the mounting portion in a state in which the actuator body is prevented from coming loose in the vertical direction relative to the mounting portion by the guide bolt.

[0010] According to the first aspect of the present invention, by simply setting the actuator body in a rotatable state, the displacement mechanism of the water supply control device can be displaced by rotating the actuator body in a circumferential direction without releasing the connection between the displacement mechanism of the water supply control device and the drive mechanism of the electric actuator, and without providing a complex mechanism such as a clutch structure in the electric actuator. Therefore, the water supply control device can be easily manually operated in an emergency. Furthermore, since the actuator body can be rotated smoothly and stably, the water supply control device can be manually operated more easily.

[0011] A second invention is according to the first invention, and the fixing bolt is a fall-off prevention bolt having a thread only on the tip portion.

[0012] A third invention is according to the first or second invention, and the actuator body has a ring-shaped or rod-shaped handle portion that protrudes outward from an outer surface of the body case.

[0013] According to the third aspect of the present invention, the actuator body can be easily rotated by gripping the handle portion, so that the water supply control device can be manually operated more easily. Effect of the Invention

[0014] According to this invention, the water supply control device can be easily manually operated in an emergency without releasing the connection between the displacement mechanism of the water supply control device and the drive mechanism of the electric actuator, and without providing a complex mechanism such as a clutch structure in the electric actuator.

[0015] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing a field water management system using an electric actuator according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing the internal structure of a water faucet. [Diagram 3] FIG. 2 is a diagram illustrating an internal structure of the electric actuator. [Figure 4] FIG. 2 is a diagram showing an actuator main body. [Diagram 5] FIG. [Figure 6] FIG. 1 is a diagram showing a water faucet equipped with an electric actuator. [Figure 7] 13 is an enlarged schematic view showing a connection portion between the actuator body and a mounting portion in a fixed state; FIG. [Figure 8] 13 is an enlarged schematic view showing a connecting portion between the actuator body and a mounting portion in a rotatable state; FIG. [Figure 9]FIG. 11 is a schematic diagram showing an electric actuator according to another embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 1, an electric actuator 16 according to an embodiment of the present invention is attached to a water supply control device such as a water faucet 12 and a water outlet 14 installed in a farm field 100, and operates a displacement mechanism of the water supply control device. As will be described in detail later, the electric actuator 16 comprises an actuator body 40 and an attachment portion 42 provided on its lower side, and the connecting portion between the actuator body 40 and the attachment portion 42 has a structure that can be switched between a fixed state and a rotatable state.

[0018] In this embodiment, the electric actuator 16 is used in a field water management system 10. First, an example of the configuration of the field water management system 10 will be briefly described below. However, the configuration of the field water management system 10 (such as the specific configurations of the water supply tap 12, the water outlet 14, and the electric actuator 16) is not limited to this example and can be changed as appropriate.

[0019] As shown in Fig. 1, the field water management system 10 is a field facility that manages water in a field 100 by remote control or automatic control based on a pre-stored program. In this embodiment, the field water management system 10 includes a water supply tap 12 and a water outlet 14, and an electric actuator 16 is attached to each of the water supply tap 12 and the water outlet 14. In other words, electric actuators 16 having the same structure are used as the electric actuators that drive the displacement mechanisms of the water supply tap 12 and the water outlet 14.

[0020] Although not shown in the figure, the field 100 is appropriately provided with sensor terminals such as a water level sensor such as an ultrasonic sensor that detects the field water level, various temperature sensors that detect air and water temperatures, a pressure sensor that detects air pressure, and a soil moisture sensor that detects soil moisture. The sensor terminals are connected to the electric actuator 16 via wiring.

[0021] In this embodiment, the field water management system 10 is a system including a plurality of cultivated areas divided by ridges 102. The water supply taps 12 and the water outlets 14 are installed in each cultivated area, and the electric actuators 16 attached thereto are wirelessly connected to a repeater (parent device) by a wireless communication method conforming to a specific low-power wireless standard (920 MHz band). Each electric actuator 16 is wirelessly connected to a remote control terminal such as a smartphone, tablet terminal, PDA, or PC owned by a user via the repeater and a management server or the like installed on the network. 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.

[0022] It is advisable to use cloud computing for this wireless communication. For example, information acquired by each electric actuator 16 (information on the status of the water supply tap 12 and the water outlet 14, such as the valve opening degree of the water supply tap 12 and the outlet height of the water outlet 14, and sensor information such as the field water level received from the sensor terminal) is transmitted as needed to a cloud server, which is an example of a management server, and stored therein. A user can access the cloud server from a remote control terminal to check the information acquired by each electric actuator 16 and remotely control each electric actuator 16 using the remote control terminal, thereby managing the water in the field 100.

[0023] The water supply faucet 12 is a water supply device for controlling the water supply to the farm field 100, and has a displacement mechanism including a valve stem, a valve body, etc. In this embodiment, a water supply faucet 12 of the type that is widely used and in which the valve stem and the valve body move up and down in response to the rotation of the valve stem is used.

[0024] Briefly described with reference to FIG. 2, the water faucet 12 includes a cylindrical valve box 20. The upper half of the valve box 20 is covered with a dome-shaped splash-proof cover 22, and a plurality of water outlets 24 are formed in the upper part of the side wall of the valve box 20 so as to be aligned in the circumferential direction. A bearing 26 having a female thread formed on the inner peripheral surface is provided at the upper end of the valve box 20, and a valve shaft 28 having a male thread formed on the outer peripheral surface is screwed into this bearing 26 so as to penetrate the splash-proof cover 22. A disc-shaped valve body 30 having a water stop rubber 30a on the lower surface is provided at the lower end of the valve shaft 28. A valve seat 32 having a water passage port 32a is provided at approximately the center inside the valve box 20. In such a water faucet 12, when a rotational force about the axis is applied to the valve shaft 28, the valve shaft 28 and the valve body 30 move up and down by the feed screw mechanism, and the water passage port 32a of the valve seat 32 is opened and closed. That is, the water faucet 12 of this embodiment is provided with a displacement mechanism including a valve body 30 that moves up and down as the valve shaft 28 rotates.

[0025] Returning to Figure 1, such a water supply faucet 12 is placed in a water supply basin 104 provided on a ridge 102, and is attached to the downstream end of a branch pipe 108 that branches off from an irrigation pipeline 106 laid under the ridge 102 and extends into the field 100. An electric actuator 16 is attached above the water supply faucet 12, and the displacement mechanism of the water supply faucet 12 (the valve shaft 28 and the valve body 30) is operated by the electric actuator 16.

[0026] On the other hand, the water outlet 14 is a drainage device for controlling drainage from the farm field 100, and has a displacement mechanism including a partition. In this embodiment, a water outlet 14 having a water level setting function is used. Simply put, the water outlet 14 has a cylindrical partition 34 whose upper opening functions as a water outlet, and the partition 34 moves up and down to adjust the height of the drain outlet.

[0027] Such a water outlet 14 is disposed in a catch basin 110 provided on the ridge 102, and is attached to the upstream end of a drainage pipe 114 that extends to a drainage channel 112. An electric actuator 16 is attached to the water outlet 14, and a displacement mechanism (partition body 34) of the water outlet 14 is moved up and down by the electric actuator 16. However, when attaching the electric actuator 16 to the water outlet 14, an adapter 36 is used that can convert the rotational force of the rotating shaft 66 of the electric actuator 16 into a force in the up and down direction (axial direction) and transmit it to the partition body 34.

[0028] Referring to Figure 3 together with Figure 1, the electric actuator 16 is a device for operating the displacement mechanism of a water supply control device such as the water tap 12 and the water outlet 14 using the driving force of a motor 60, and is equipped with an actuator body 40 and an attachment portion 42 (mounting base) for attaching the actuator body 40 to the water supply control device.

[0029] 3 and 4, the actuator body 40 includes a cylindrical body case 50 made of synthetic resin such as hard polyvinyl chloride. The body case 50 constitutes the upper housing of the electric actuator 16. Furthermore, a plurality of first bolt holes 50a into which the fixing bolts 80 are screwed are formed at a lower end of the body case 50 at predetermined intervals in the circumferential direction. In this embodiment, four first bolt holes 50a are formed at 90 degree intervals.

[0030] A solar cell panel 52 is detachably attached to the top of the main body case 50. The solar cell panel 52 is supported at a predetermined angle by a metal holder 54 in the form of a bent plate.

[0031] Inside the main body case 50, an electronic board 56, a storage battery 58, and a drive mechanism including a motor 60, a main gear 62, etc. are housed.

[0032] Although not shown, the electronic board 56 is provided with a control unit including a CPU and memory, and a wireless communication unit including a wireless communication module. The motor 60, the operation panel 68, the wireless communication unit, the sensor terminal, and the like are electrically connected to the control unit. The CPU of the control unit is responsible for the overall control of the electric actuator 16 and controls the driving of the motor 60, etc. The memory is a comprehensive reference to ROM, RAM, HDD, etc., and stores a control program that controls the operation of the electric actuator 16 and functions as a work area when the CPU is operating. The wireless communication unit is connected to an antenna and performs wireless communication with external devices such as a repeater via the antenna.

[0033] The storage battery 58 stores the power generated by the solar panel 52. The motor 60 is driven by the power stored in the storage battery 58. A small gear 64 is provided at the tip of an output shaft 60a of the motor 60, and the main gear 62 is connected to the small gear 64 to receive driving force from the motor 60 and rotate around its axis.

[0034] The main gear 62 is a double-boss type gear, and a substantially cylindrical rotating shaft 66 is inserted into the shaft portion of the main gear 62. A coupling portion 66a is formed at the lower end of the rotating shaft 66, which is connected to the upper end of the valve shaft 28 of the water faucet 12, etc. Also, a key groove 62a extending along the axial direction is formed on the inner peripheral surface of the shaft portion of the main gear 62, and a sliding key 66b engaging with the key groove 62a is formed on the outer peripheral surface of the rotating shaft 66 so as to extend along the axial direction. As a result, the rotating shaft 66 rotates together with the rotation of the main gear 62, and is able to slide in the axial direction relative to the shaft portion of the main gear 62.

[0035] Further, an operation panel 68 is provided on the outer surface of the main body case 50 to receive operation instructions from the user, that is, to allow the user to directly operate the electric actuator 16. The operation panel 68 is appropriately provided with a main power switch, an up button, a down button, a selection button for switching the operation mode of the electric actuator 16 (remote mode, automatic mode, manual mode, etc.), and the like. The operation panel 68 is also provided with connection terminals for connecting wiring extending from the sensor terminals, and the like.

[0036] 5, the mounting portion 42 constitutes the lower part of the housing of the electric actuator 16, and includes a cylindrical side wall portion 70 and a bottom plate portion 72 provided at the lower end portion of the side wall portion 70. The side wall portion 70 is formed from a synthetic resin such as hard polyvinyl chloride, and the bottom plate portion 72 is formed from a metal such as aluminum or stainless steel.

[0037] The side wall portion 70 is formed with an inspection port 70a (see FIG. 3) for checking the operation of the rotating shaft 66 and other components and for performing maintenance work such as cleaning. In addition, a plurality of holes 70b are formed at the upper end of the side wall portion 70, which are arranged at a predetermined interval in the circumferential direction. In this embodiment, four holes 70b are formed at 90 degree intervals. The mounting portion 42 is fixed to the lower end of the main body case 50 by fastening a fixing bolt 80 to the first bolt hole 50a of the main body case 50 through this hole 70b. Meanwhile, a through hole 72a is formed in the center of the bottom plate portion 72, through which the upper end of the valve shaft 28 of the water supply valve 12 and other components are inserted. In addition, a plurality of holes 72b are formed in the bottom plate portion 72, which are arranged in the circumferential direction and the radial direction around the through hole 72a, and the mounting portion 42 (and thus the electric actuator 16) is bolted to the upper surface of the water supply valve 12 and other components using this hole 72b.

[0038] 6, when mounting the electric actuator 16 on the water faucet 12, the electric actuator 16 is placed on the splash prevention cover 22 of the water faucet 12, and then the splash prevention cover 22 and the bearing 26 are bolted to the bottom plate portion 72 of the mounting portion 42. In addition, the upper end portion of the valve shaft 28 of the water faucet 12 and the coupling portion 66a of the rotating shaft 66 of the electric actuator 16 are non-rotatably connected.

[0039] In the water faucet 12 to which the electric actuator 16 is attached, for example, when a user accesses a management server using a remote control terminal and transmits an operation instruction (control signal) to fully close, fully open, or open the water faucet 12 to an arbitrary degree, a control signal corresponding to the operation instruction is transmitted from the management server to the electric actuator 16 via a repeater. The control unit of the electric actuator 16 drives the motor 60 in response to the received control signal. The driving force of the motor 60 is transmitted to the main gear 62, and the rotating shaft 66 rotates together with the main gear 62. As a result, a rotational force is applied to the valve shaft 28 of the water faucet 12, which is fixedly connected to the rotating shaft 66. The valve shaft 28 to which the rotational force is applied is moved up and down by the screw mechanism, and the valve element 30 is moved to a fully open position, a fully closed position, or the like.

[0040] Similarly, although not shown, when mounting the electric actuator 16 above the water outlet 14, the electric actuator 16 is placed on a base provided on the water outlet 14 and bolted, and the upper end of the connecting shaft of the adapter 36 is non-rotatably connected to the coupling part 66a of the rotating shaft 66. In the water outlet 14 to which the electric actuator 16 is mounted, when the user transmits an operation command to set the drain height of the water outlet 14 (the height position of the partition body 34), the control part of the electric actuator 16 drives the motor 60 in response to the control signal to change the drain height of the water outlet 14.

[0041] As described above, in a water supply control device (water supply faucet 12 or water outlet 14) to which an electric actuator 16 is attached, the displacement mechanism of the water supply control device is normally electrically displaced (operated) by the electric actuator 16. However, when a failure (malfunction) occurs in the electric actuator 16, it becomes necessary to manually displace the displacement mechanism of the water supply control device. At this time, it is time-consuming to disconnect the valve shaft 28 of the water supply faucet 12 from the rotating shaft 66 of the electric actuator 16 and to attach a handle to the valve shaft 28 to perform manual operation.

[0042] In this embodiment, the following configuration is adopted for the electric actuator 16, and the following manual operation method is adopted to allow the water supply control device to be easily operated manually. This will be specifically described below with reference to Figs. 3 to 8.

[0043] 3 to 8, in the electric actuator 16 of this embodiment, a structure that enables the actuator body 40 to be switched between a fixed state and a rotatable state is provided at the connecting portion between the actuator body 40 and the mounting portion 42. In other words, the actuator body 40 is provided so as to be switchable between a fixed state in which it is fixed non-rotatably to the mounting portion 42, and a rotatable state in which it is rotatable in the circumferential direction relative to the mounting portion 42.

[0044] As described above, a plurality of first bolt holes 50a are formed at a predetermined interval in the circumferential direction at the lower end of the main body case 50 of the actuator main body 40. Meanwhile, a plurality of holes 70b are formed at an upper end of the side wall portion 70 of the mounting portion 42 at a predetermined interval in the circumferential direction. Then, as can be clearly seen from FIG. 7, the mounting portion 42 is fixed to the lower end of the main body case 50 by screwing the fixing bolt 80 into the first bolt hole 50a through the hole 70b. In other words, the actuator main body 40 is fixed to the mounting portion 42 so as not to rotate.

[0045] On the other hand, as shown in Fig. 8, by removing (unscrewing) the fixing bolt 80 from the first bolt hole 50a, the fixing of the mounting part 42 to the main body case 50 is released. In other words, the actuator body 40 is placed in a rotatable state in which it is rotatable in the circumferential direction relative to the mounting part 42. In this embodiment, a fall-off prevention bolt having a thread 80a formed only at the tip portion is used as the fixing bolt 80. This prevents the fixing bolt 80 from falling off from the mounting part 42 when the fixing bolt 80 is unscrewed from the first bolt hole 50a, and prevents the fixing bolt 80 from being lost.

[0046] In this embodiment, the actuator body 40 is rotatably provided in a rotatable state in a state where it is prevented from coming off in the up-down direction with respect to the mounting portion 42. Specifically, an annular guide groove 70c extending in the circumferential direction is formed on the inner surface of the upper end portion of the side wall portion 70 of the mounting portion 42 at a height position lower than the hole 70b. However, the height position of the guide groove 70c may be below or above the hole 70b as long as it is close to the hole 70b. Meanwhile, one or more second bolt holes 50b are formed on the lower end portion of the main body case 50 of the actuator body 40 at a height position corresponding to the guide groove 70c. For example, two second bolt holes 50b are formed at 180 degree intervals. A guide bolt 82 is attached to this second bolt hole 50b. At this time, the guide bolt 82 is provided so that its tip portion protrudes from the outer surface of the main body case 50, and the tip portion (protruding portion) of the guide bolt 82 is used as a guide protrusion 82a that engages with the guide groove 70c.

[0047] When the actuator body 40 is rotated, the guide protrusion 82a fitted in the guide groove 70c moves along the guide groove 70c, so that the actuator body 40 is rotated in a state where it is prevented from coming off (movement is restricted) in the vertical direction relative to the mounting portion 42. In this way, the actuator body 40 can rotate in a state where it is prevented from coming off in the vertical direction relative to the mounting portion 42, so that the actuator body 40 can be rotated smoothly and stably. Therefore, the water supply control device can be manually operated more easily.

[0048] Furthermore, a handle portion 86 (grip portion) that protrudes outward from the outer surface is provided at the upper end of the main body case 50. In this embodiment, the handle portion 86 is formed in a circular plate shape (brim shape) from synthetic resin such as hard polyvinyl chloride, and is fixed to the outer surface of the main body case 50 by an appropriate method such as welding. However, the shape of the handle portion 86 can be changed as appropriate, and the handle portion 86 can also be formed into a rod shape, etc. By providing such a handle portion 86, it becomes easier for the operator to apply force and rotate the actuator main body 40. Therefore, the water supply control device can be manually operated more easily.

[0049] Furthermore, in this embodiment, the circumferential position of the actuator body 40 in the fixed state can be changed. As described above, in this embodiment, the first bolt holes 50a are formed at 90 degree intervals, so that the circumferential position of the actuator body 40 relative to the mounting portion 42 (i.e., the installation direction) can be changed in four directions. In this way, by making the circumferential position of the actuator body 40 in the fixed state changeable, the orientation (installation direction) of the solar cell panel 52 can be adjusted to face south, for example. Note that by increasing the number of the first bolt holes 50a, the circumferential position of the actuator body 40 (and thus the orientation of the solar cell panel 52) can be adjusted more finely.

[0050] Next, a manual operation method of the water supply control device to which the electric actuator 16 is attached as described above will be briefly described. For example, when it becomes necessary to manually operate the water supply faucet 12 to which the electric actuator 16 is attached, as shown in FIG. 8, the fixing bolt 80 is released from the first bolt hole 50a to make the actuator body 40 rotatable. If a sensor terminal such as a water level sensor is connected to the electric actuator 16, the connector is removed. Then, without disconnecting the valve shaft 28 of the water supply faucet 12 from the rotating shaft 66 of the electric actuator 16 (i.e., while the displacement mechanism of the water supply control device and the drive mechanism of the electric actuator 16 are still connected), the handle portion 86 is gripped and the actuator body 40 is rotated in the circumferential direction (clockwise or counterclockwise). In other words, the entire actuator body 40 is rotated relative to the mounting portion 42 while the mounting portion 42 is fixed to the water supply faucet 12. When the actuator body 40 is rotated, the valve shaft 28 of the water supply tap 12 also rotates together with the rotating shaft 66, and the valve shaft 28 to which a rotational force is applied is moved up and down by the screw mechanism, and the valve body 30 is moved to a fully open position, a fully closed position, etc. (i.e., the displacement mechanism is displaced).

[0051] As described above, according to this embodiment, the actuator body 40 is provided switchably between a fixed state and a rotatable state with respect to the mounting portion 42, and the displacement mechanism of the water supply control device is displaced by rotating the actuator body 40 in the circumferential direction, so that the water supply control device can be easily manually operated. In other words, the water supply control device can be easily manually operated in an emergency, etc., without releasing the connection between the displacement mechanism of the water supply control device and the drive mechanism of the electric actuator 16, and without providing the electric actuator 16 with a complex mechanism such as a clutch structure.

[0052] In the above embodiment, the electronic board 56, the storage battery 58, the motor 60, the main gear 62, etc. are accommodated inside the main body case 50, but this is not limited thereto. For example, as in the embodiment shown in FIG. 9, only the drive mechanism such as the motor 60 and the main gear 62 can be accommodated inside the main body case 50, and the electronic board 56 and the storage battery 58 can be arranged in another case provided outside the main body case 50. That is, the electric actuator 16 can be divided into a drive device including a drive mechanism and a control device including the electronic board 56 (control unit), and the actuator body 40 attached to the water supply control device can be composed of only the drive device. In this case, the motor 60 is preferably electrically connected to the electronic board 56 via wiring 88 or the like.

[0053] 9, by accommodating only the drive mechanism such as the motor 60 and main gear 62 inside the main body case 50, that is, by configuring the actuator body 40 attached to the water supply control device with only the drive device, it is possible to reduce the size and weight of the actuator body 40. This makes it easy to rotate the actuator body 40 in the circumferential direction relative to the mounting part 42, and makes it easier to manually operate the water supply control device in an emergency, etc.

[0054] In the above embodiment, the electric actuator 16 is provided with the solar cell panel 52, but if a large-capacity storage battery 58 is used, it is not necessary to provide the solar cell panel 52. If the field water management system 10 is applied to an environment where other power sources such as commercial power sources can be used, the electric actuator 16 is not necessarily required to provide the solar cell panel 52 and the storage battery 58.

[0055] It should be noted that the specific values ​​of the dimensions and the specific shapes given above are merely examples and can be changed as appropriate according to the needs of the product specifications, etc. [Explanation of symbols]

[0056] 10... Field water management system 12...Water supply valve (water supply control device) 14 ... Water outlet (water supply control device) 16 … Electric actuator 40...Actuator body 42 …Mounting part 50 ... Main body case 70c ... Guide groove 80 ... Fixing bolt 82 ... Guide bolt 82a ... Guide protrusion 86 ... Handle 100 ... field

Claims

1. An electric actuator attached to a water supply control device having a displacement mechanism for controlling water supply to or drainage from a farm field, the electric actuator actuating the displacement mechanism, an actuator body having a drive mechanism that drives the displacement mechanism and a body case that houses the drive mechanism; and a mounting portion for mounting the actuator body to the water supply control device; The main body case includes: A first bolt hole formed in a lower end portion of the main body case, and a second bolt hole formed in a lower end portion of the main body case at a height position different from that of the first bolt hole; The mounting portion is a side wall portion fitted to a lower end portion of the main body case; a through hole formed in the side wall portion at a position corresponding to the first bolt hole; and a guide groove is formed in the side wall portion at a position corresponding to the second bolt hole and extends in a circumferential direction of the side wall portion; A fixing bolt screwed into the first bolt hole through the through hole; and a guide bolt that is screwed into the second bolt hole and has a tip portion engaged with the guide groove, The actuator body is switchable between a fixed state in which it is fixed non-rotatably relative to the mounting portion and a rotatable state in which it can rotate 360 ​​degrees or more in a circumferential direction relative to the mounting portion, and in the rotatable state, it can rotate in the circumferential direction relative to the mounting portion while being prevented from coming loose in the vertical direction relative to the mounting portion by the guide bolt.

2. 2. The electric actuator according to claim 1, wherein the fixing bolt is a fall-off prevention bolt having a screw thread formed only at a tip portion.

3. 3. The electric actuator according to claim 1, wherein the actuator body has a handle portion in the shape of an annular plate or a rod, the handle portion protruding outward from an outer surface of the main body case.

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