JP7527009B2 - Weeding equipment - Google Patents

Description

The present invention relates to a weeding device that removes weeds from flooded rice paddies.

There is high consumer demand for pesticide-free or reduced-pesticide rice, which offers added value such as safety and security. In pesticide-free or reduced-pesticide rice cultivation, weeding is sometimes done using machinery instead of spraying herbicides.
For example, Patent Document 1 discloses a weeding brush that is attached to a traveling machine body that moves through rice paddies to remove weeds. This weeding brush removes weeds by rotation and includes multiple linear elastic bodies and a base body to which the linear elastic bodies are fixed. The multiple linear elastic bodies extend in an elongated manner in the direction of the rotation center line and are arranged to surround a vertically long space, forming a cage-shaped structure with an open tip.
Patent Document 2 also discloses a paddy field weeding machine that includes a running machine and a weeder that is arranged on the running machine and whose height relative to the running machine can be adjusted by a height adjustment mechanism that is arranged between the running machine, the weeder having a weeding claw device that scrapes off weeds between rice stalks by reciprocating in a direction perpendicular to the running direction of the running machine using a drive device, and a grass cutting device arranged behind the weeding claw device, the weeding claw device having a claw base and a number of weeding claws arranged on the claw base, the grass cutting device having a number of cutters that rotate vertically and are each provided at positions that will become the spaces between the rows of rice stalks during weeding work, the cutters scraping and cutting weeds between the rows of rice stalks and cutting weeds that float to the surface of the water by scraping them off with the weeding claw device.

JP 2020-43843 A JP 2014-76004 A

Currently, most rice paddy weeding machines use weed removal techniques to remove weeds by floating them away, but this can lead to problems such as weeds re-establishing themselves in the soil after being removed.
However, Patent Document 1 does not disclose any means for preventing re-establishment of weeds that have been removed.
Furthermore, Patent Document 2 describes a method in which weeds floating on the water surface are not left as they are, but are instead cut to prevent them from re-rooting in the soil on the rice field. However, because the weeds are cut within the water on the rice field surface, there is a concern that the weeds may not be cut into small pieces depending on their floating position or height.
As a measure to prevent weeds from re-establishing, it is possible to continue water management at a depth of about 10 cm for a certain period of time, or to replace the water on the paddy field after weeding to remove the floating weeds. However, in order to make the water on the paddy field 10 cm deep, it is necessary to maintain ridges of a certain height, and replacing the water on the paddy field requires new water management work associated with the inflow and outflow of water, so there are many paddy fields for which it is difficult to apply these measures to prevent weeds from re-establishing.
SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a weeding device that effectively prevents re-establishment of weeds that have been detached from the soil in flooded paddy fields.

The weeding device of the present invention described in claim 1 is a weeding device that removes weeds 110 from a paddy field filled with water 100, and is equipped with floating means 10 that separates the weeds 110 from the soil 120 and suspends them in the water, suction means 20 that sucks in the weeds 110 suspended in the water together with the water 100, and weed treatment means 30 that captures or cuts the weeds 110 mixed in the sucked water 100, and is characterized in that the water 100 from which the weeds 110 have been removed, or the water 100 containing the cut weeds 110, is returned to the paddy field.
The present invention described in claim 2 is characterized in that, in the weeding device described in claim 1, the weed treatment means 30 is a filter 30A that is arranged in a flow path through which the water 100 and weeds 110 sucked by the suction means 20 flow, and captures the weeds 110 and the seeds of the weeds 110.
The present invention described in claim 3 is characterized in that, in the weeding device described in claim 1, the weed treatment means 30 is a mixer 30B having a cutting blade 32 rotatably arranged in a flow path through which the water 100 and weeds 110 sucked by the suction means 20 flow, and cutting the weeds 110 with the rotating cutting blade 32.
The present invention described in claim 4 is characterized in that, in the weeding device described in any one of claims 1 to 3, the floating means 10 has a sinking section 11 that sinks into the soil 120, and the weeds 110 are pulled out of the soil 120 by rotating the sinking section 11 and floated in the water.
The present invention as set forth in claim 5 is characterized in that, in the weeding device as set forth in claim 4, the recessing portion 11 has a predetermined flexibility.
The present invention as set forth in claim 6 is characterized in that the weeding device as set forth in claim 4 or 5 further comprises an entanglement elimination means 70 for removing the weeds 110 entangled in the recession portion 11 .
The seventh aspect of the present invention is characterized in that in the weeding device of the sixth aspect, the tangle-eliminating means 70 includes a rotation direction switching section that switches the rotation direction of the recessing section 11.
The present invention described in claim 8 is characterized in that, in a weeding device described in any one of claims 1 to 7, the suction means 20 has a tube 21 having one end immersed in water and an ejector 22 connected to the tube 21.
The present invention as described in claim 9 is characterized in that, in the weeding device as described in any one of claims 1 to 8, it is provided with a weed position detection means 40 which detects the position of weeds 110 growing in the soil 120, and the flotation means 10 is moved to the position of the detected weeds 110.
The present invention according to claim 10 is characterized in that the weeding device according to claim 9 further comprises backflow prevention means 50 for preventing the weeds 110 and water 100 sucked into the suction means 20 from flowing back.

The present invention can effectively prevent weeds that have been detached from the soil in flooded rice paddies from re-establishing their roots.

FIG. 1 is a diagram showing a main part of a weeding device according to an embodiment of the present invention, illustrating a state in which weeds are separated from soil. A diagram showing the state in which the sucked water is returned to the paddy field. FIG. 13 shows the state of water flow generation using the ejector. FIG. 2 shows the floating means. FIG. 1 is a schematic diagram of a weed treatment means in a weeding device according to another embodiment of the present invention;

The weeding device according to the first embodiment of the present invention is a weeding device for removing weeds from flooded rice paddies, and is equipped with flotation means for separating the weeds from the soil and suspending them in the water, suction means for sucking in the weeds suspended in the water together with the water, and weed treatment means for capturing or cutting weeds mixed in the sucked water, and returns the water from which weeds have been removed, or water containing the cut weeds, to the rice paddy.
According to this embodiment, weeds suspended in the water can be sucked up and collected or cut, which effectively prevents weeds from regrowing. In addition, by returning the sucked up water to the paddy field, new water management work associated with water inflow and outflow is not required.

In a second embodiment of the present invention, in the weeding device according to the first embodiment, the weed treatment means is a filter that is disposed in a flow path through which the water and weeds sucked by the suction means flow and that captures weeds and weed seeds.
According to this embodiment, it is possible to collect weeds to effectively prevent them from re-establishing, and also to collect the seeds to suppress the proliferation of weeds.

In the third embodiment of the present invention, in the weeding device of the first embodiment, the weed treatment means is a mixer having a cutting blade rotatably arranged in a flow path through which the water sucked by the suction means and the weeds flow, and which cuts the weeds with the rotating cutting blade.
According to this embodiment, the weeds can be cut into small pieces and effectively prevented from re-establishing.

A fourth embodiment of the present invention is a weeding device according to any one of the first to third embodiments, in which the floating means has a sinking part that sinks into the soil, and the sinking part rotates to pull out the weeds from the soil and float them in the water.
According to this embodiment, it becomes easier to pull out weeds together with their roots from the soil and suspend them in water.

A fifth embodiment of the present invention is characterized in that in the weeding device according to the fourth embodiment, the sinking portion has a predetermined flexibility.
According to this embodiment, the recessed portion bends when it comes into contact with the soil, making it difficult for weeds to become entangled.

A sixth embodiment of the present invention is a weeding device according to the fourth or fifth embodiment, further comprising entanglement elimination means for removing weeds entangled in the recession portion.
According to this embodiment, when weeds become tangled, the tangle-removing means can be used to quickly remove the weeds, thereby preventing a decrease in weed-removing efficiency.

A seventh embodiment of the present invention is such that the weeding device according to the sixth embodiment further includes, as tangle-eliminating means, a rotation direction switching section for switching the rotation direction of the recessing section.
According to this embodiment, the rotation direction switching part rotates the embedding part in the direction opposite to the rotation direction used for pulling out weeds from the soil, thereby making it possible to remove tangled weeds.

An eighth embodiment of the present invention is a weeding device according to any one of the first to seventh embodiments, wherein the suction means has a tube having one end immersed in water and an ejector connected to the tube.
According to this embodiment, by using an ejector that has no mechanically moving parts, it is possible to reduce the possibility of problems caused by clogging with sucked impurities.

A ninth embodiment of the present invention is a weeding device according to any one of the first to eighth embodiments, which is provided with a weed position detection means for detecting the position of weeds growing in the soil, and the flotation means is moved to the position of the detected weeds.
According to this embodiment, localized weed control can be achieved by detecting the position of the weeds and then weeding them.

A tenth embodiment of the present invention is characterized in that the weeding device according to the ninth embodiment further comprises backflow prevention means for preventing backflow of the weeds and water sucked into the suction means.
According to this embodiment, since the backflow prevention means is provided, even if suction is stopped, the sucked up weeds will not flow back into the rice paddy. Therefore, unnecessary suction can be stopped and energy consumption can be reduced.

Hereinafter, a weeding device according to an embodiment of the present invention will be described.
Figures 1, 2 and 3 show the main parts of the weeding device according to this embodiment, with Figure 1 showing the state where weeds are separated from the soil, Figure 2 showing the state where sucked water is returned to the paddy field, and Figure 3 showing the state where a water flow is generated using an ejector. The arrows in Figures 1 and 3 indicate the direction of the water flow during sucking. Figure 4 shows the flotation means according to this embodiment.
The weeding device is used to remove weeds 110 in a paddy field filled with water (paddy surface water) 100. The weeding device includes: floating means 10 for separating the weeds 110 from the soil 120 and floating them in the water; suction means 20 for sucking the weeds 110 suspended in the water together with the water 100; weed treatment means 30 for treating the weeds 110 mixed in the sucked water 100; weed position detection means 40 for detecting the position of the weeds 110 growing in the soil 120; and backflow prevention means 50 for preventing the sucked weeds 110 and water 100 from flowing back.

The levitation means 10 is attached to the tip of a robot arm 60 which is mounted on a mobile cart (not shown) or the like.
The flotation means 10 has a submerged portion 11 that submerges at least a part of the soil 120, a base portion 12 to which the submerged portion 11 is attached, a support portion 13 that supports the base portion 12, and a fixing nut 14. FIG. 4(a) shows the base portion 12 to which the submerged portion 11 is attached, FIG. 4(b) shows the support portion 13, FIG. 4(c) shows the fixing nut 14, and FIG. 4(d) shows a state in which the base portion 12 to which the submerged portion 11 is attached and the support portion 13 are combined and fixed with the fixing nut 14. The support portion 13 has a first ring portion 13a and a second ring portion 13b having a smaller diameter than the first ring portion 13a. The first ring portion 13a is provided with a plurality of arm connection portions 13c for connecting to the tip of the robot arm 12. The support portion 13 also has a cylindrical portion 13d having a circular cross section that is provided to penetrate the first ring portion 13a and the second ring portion 13b. Of the tubular portion 13d, the outer periphery of the end protruding toward the second ring portion 13b is formed with a threaded portion 13e with a thread for engaging with the fixing nut 14, and the outer periphery of the opposite end is formed with a stepped portion 13g used for connecting to the pipe 21.

The embedding portion 11 is composed of a plurality of rod-shaped bodies. The rod-shaped bodies are made of metal or resin, and each has, for example, a diameter of 1 to 3 mm and a total length of 20 to 30 mm. At least a part of the rod-shaped bodies penetrates the soil 120, but if the amount of the rod-shaped bodies that penetrates the soil 120 is less than about 1/3 of the total length, the weeds 110 cannot be sufficiently pulled out of the soil 120 and suspended in the water, and if the amount that penetrates is more than about 2/3 of the total length, there is a possibility that the weeds 110 will be pushed into the soil 120. For this reason, it is preferable that about 1/3 to 2/3 of the total length of the rod-shaped bodies penetrates the soil 120 from the tip.
The base portion 12 has a hole 12a through which the cylindrical portion 13d passes, and a wall portion 12b is provided on the periphery of one surface of the base portion 12. The recessed portion 11 is attached to the other surface of the base portion 12. A ball bearing 16 is attached to the hole 12a of the base portion 12.
The base part 12 is rotatably attached to the support part 13 such that one surface on which the wall part 12b is provided is covered by the second ring part 13b of the support part 13. At this time, the part of the cylindrical part 13d on which the threaded part 13e is provided protrudes beyond the other surface of the base part 12 through the hole 12a, and a fixing nut 14 is fitted therein.
In addition, a sliding member such as a plain bearing may be attached to the hole 12 a of the base portion 12 instead of the ball bearing 16 .

As shown in Fig. 1, the tube 21 of the suction means 20 can be attached so as to protrude from the other surface of the base 12. In this case, the length by which one end of the tube 21 protrudes from the other surface of the base 12 is made shorter than the length of the rod-shaped body. Also, one end of the tube 21 can be fixed to the step portion 13g shown in Fig. 4. In this case, water 100, weeds 110, etc. are sucked in from the lower end of the tube portion 13d.
It is preferable that the size (horizontal size) of the submerged part 11 when viewed from above is set smaller than the spacing between rows and between plants. For example, when the spacing between rows is 30 cm and the spacing between plants is 15 cm, the size is set to a size that fits within a square of about 5 cm to 10 cm. This makes it easier to move the submerged part 11 between the plants as well as between the rows, and allows the weeds 110 to be removed from the soil 120 without damaging the cultivated plants such as rice. It is preferable to perform the weeding work using the weeding device while the weeds 110 are as small as possible. For example, by assuming that the weeds 110 to be removed are about 1 to 2 cm in size, the floating means 10, the suction means 20, etc. can be made small.

1 has one arm, it is also possible to use a so-called parallel link robot arm 60 in which three arms made up of link mechanisms and joint mechanisms work together to control the movement of the arm tips. Figure 4(e) shows a state in which a ball joint 13f for this parallel link is provided at each arm connection portion 13c.
Fig. 4(f) is a cross-sectional view of Fig. 4(e). The levitation means 10 is provided with a rotation drive unit 15 that rotates the base part 12. The rotation drive unit 15 has a rotation drive magnet 15a arranged in a circular shape inside the base part 12, and a rotation drive coil 15b that is cylindrically provided on the support part 13 so as to face the rotation drive magnet 15a at a predetermined distance, and when a current flows through the rotation drive coil 15b, the base part 12 rotates together with the recessed part 11.
The embedding unit 11 can perform a raking operation in which it reciprocates approximately horizontally within the soil 120 without rotating, and a rotation operation in which it rotates within the soil 120, to entangle the weeds 110 together with their roots and pull them out of the soil 120. Which operation is selected depends on the state of the roots of the weeds 110, etc., but basically, if the weeds are small, about 2 cm in size, the rotation operation is performed, and if the weeds have grown large, the raking operation is performed.

The recession unit 11 may be configured to perform only one of the scraping operation and the rotating operation.
When the submerged portion 11 performs a rotating operation, the rod-shaped bodies are arranged at equal distances from the rotation center of the base portion 12, i.e., lined up on a circumference. They may also be arranged in double rows concentrically, and in this case, the distance between the rows is preferably about 20 mm. The submerged portion 11 performing the rotating operation is preferably circular when viewed from above.
On the other hand, if the recessed portion 11 does not rotate, i.e., if it only performs a scraping operation, the rod-shaped bodies may be directly attached to the support portion 13. The rod-shaped bodies may also be arranged in a single linear row or in double rows. In the case of double rows, it is preferable that the distance between the rows is about 20 mm, as described above.

On the other hand, if the embedding part 11 is rotated, the weeds 110 will remain entangled, and there is a high possibility that the weeding efficiency will decrease. Therefore, it is preferable that the rod-shaped body constituting the embedding part 11 has a certain degree of flexibility. This allows the rod-shaped body to bend when it comes into contact with the soil 120, making it difficult for the weeds 110 to remain entangled. Note that, since seedlings transplanted into paddy fields take root more strongly than smaller weeds in about a week, the certain flexibility of the rod-shaped body can be set to a strength that removes the weeds 110 but not the seedlings, thereby making it possible to efficiently remove only the weeds 110.
The weeding device further includes an entanglement elimination means 70 for removing the weeds 110 entangled in the recessing part 11. In this embodiment, the entanglement elimination means 70 includes a rotation direction switching unit for switching the rotation direction of the recessing part 11. When the weeds 110 are entangled in the recessing part 11, the rotation direction switching unit rotates the recessing part 11 in a direction opposite to the rotation direction when the weeds 110 are pulled out from the soil 120, thereby removing the entangled weeds 110. As a result, when the weeds 110 are entangled, the entanglement elimination means 70 can be used to quickly remove the weeds 110, thereby preventing a decrease in weeding efficiency. The rotation direction switching unit may be configured to switch the rotation direction of the recessing part 11 at regular intervals. This makes it easier to prevent the weeds 110 from remaining entangled in the recessing part 11.
As another example of the tangle-eliminating means 70, a push-out plate that can move up and down can be provided on a rod-shaped body, and the tangled weeds 110 can be pushed out and removed by moving the push-out plate up and down along the rod-shaped body.

The suction means 20 has a pipe 21 to which an ejector 22 is connected. With one end of the pipe 21 immersed in water, the suction means 20 injects high-pressure water supplied from a high-pressure water pipe 23 from a nozzle 24 in the ejector 22 at high speed, thereby sucking up the weeds 110 and the water 100 from one end of the pipe 21. The suction means 20 is provided near the flotation means 10, and the flotation means 10 floats the weeds 110 in water and the suction means 20 simultaneously performs suction, thereby making it possible to efficiently and reliably collect the floating weeds 110. Note that, although FIG. 1 shows a state in which one end of the pipe 21 is located approximately in the center of the submerged portion 11, it may also be located closer to the end of the submerged portion 11. For example, one end of the pipe 21 may be located outside the rod-shaped bodies arranged in the circumferential direction, that is, outside the outer periphery of the base portion 12, or outside the rod-shaped bodies arranged in a straight line. Also, one end of the pipe 21 may be branched to provide a plurality of suction ports.
In addition, the suction means 20 can also be configured to suck up the water 100 using a piston pump or the like, but since the water 100 to be sucked up also contains impurities such as soil particles 121 and weeds 110, by using an ejector 22 that has no mechanical moving parts, the possibility of malfunctions due to clogging with impurities can be reduced.
It is preferable to use water from the rice field 100 pumped up by a pump or the like and filtered by a liquid cyclone or the like as the high-pressure water.

The weed treatment means 30 in this embodiment is a filter 30A that is disposed in the flow path through which the water 100 and weeds 110 sucked by the suction means 20 flow and captures the weeds 110 and the seeds of the weeds 110. The water 100 sucked from one end of the tube 21 of the suction means 20 is returned to the paddy field from the other end of the tube 21 after the weeds 110 are separated by the filter 30A. Most of the particles 121 of the soil 120 are also not separated by the filter 30A and are returned to the paddy field together with the water 100. In this way, by collecting the weeds 110 suspended in the water, it is possible to effectively prevent the weeds 110 from re-establishing their roots. Furthermore, by returning the sucked water 100 to the paddy field, it is not necessary to carry out new water management work associated with inflow and outflow.
The filter 30A has the ability to remove weeds 110 that are mixed in the sucked water 100, and is made of, for example, a wire mesh. The wire mesh preferably has mesh sizes of about 5 to 10 mm. If it is anticipated that straw chips or the like may be mixed in with the water 100, a wire mesh with mesh sizes of about 20 mm may be provided in the front stage to prevent clogging.
Also, the mesh may be made finer so that the seeds of the weeds 110 can also be removed. This makes it possible to suppress the proliferation of the weeds 110. In addition, if the seeds of the weeds 110 can also be removed, it is preferable to provide a wire mesh with a mesh size of about 1 to 3 mm behind a wire mesh with a mesh size of about 5 to 10 mm. This makes it possible to separate the weeds 110 and the seeds from the water 100, and also to suppress clogging of the filter 30A and extend the regeneration or replacement cycle. Note that a nonwoven fabric or the like may be provided behind the wire mesh with a mesh size of about 1 to 3 mm as one of the filters 30A.
In addition, if the filter 30A is configured to remove weed seeds as well, it is also possible to remove rice seeds, so that when the type of rice being cultivated is changed, the seeds of the previous rice can be removed and the proliferation of plants other than the intended cultivated plant can be suppressed. This is because there may be cases where seeds of a variety different from the rice being cultivated this year remain in the soil 120, and if these seeds germinate and grow, they will be mixed into the harvested rice, which is inconvenient.

The weeding device of the present invention is mounted on a movable cart and moves through the paddy field either by the operator's operation or automatically by a microcontroller. Weeding work may be performed on only weeds 110 found by visual inspection or a camera, but when weeding early-stage weeds 110 whose leaves have not yet emerged from the soil surface, it is necessary to work so as to paint in all spaces between plants and rows. An example of manual operation by an operator will be described below.
(1) When an operator visually finds a weed 110, he or she operates the control device to move the robot arm 60, moves the embedding portion 11 near the weed 110, and starts the suction means 20.
(2) Next, the diving part 11 is moved so as to scan the vicinity of the weed 110 while being lowered, or the diving part 11 is rotated to guide the diving part 11 around the weed 110. In either case, the rod-shaped body of the diving part 11 gets caught on the target weed 110 and pulls it out of the soil 120.
(3) The pulled out weeds 110 are suspended in the water on the surface of the paddy field, and the suction means 20 sucks up the weeds 110 together with the surrounding water 100, thereby removing the weeds 110 from the paddy field.
In addition, the operator may move along the rice rows while continuously driving the weeding device and steer the submerging section 11 toward weeds 110 detected by visual inspection, or steer the submerging section 11 so that it swings from side to side between the rice rows.

Next, an example of automatically controlling the weeding device will be described.
As shown in FIG. 1, the weed position detection means 40 has an underwater camera 41 that takes underwater images, and a detection unit 42 that processes the images taken by the underwater camera 41 to detect the positions of the weeds 110.
The weeding device operates the robot arm 60 to move the flotation means 10 and the suction means 20 to the position of the weed 110 detected by the weed position detection means 40, and separates the weed 110 from the soil 120 and suctions it together with the water 100. In this way, localized weed control can be achieved by detecting the position of the weed 110 and then performing weeding. In addition, by photographing the same position again after the flotation means 10 has finished pulling out the weed 110 growing in the soil 120, it is also possible to determine whether the weed 110 has been separated from the soil 120.
When the flotation means 10 is used to pull out the weeds 110, the surrounding water 100 becomes turbid, making it difficult to detect the position of the weeds 110; however, by sucking up the turbid water with the suction means 20, the turbidity is eliminated and detection of the position of the weeds 110 can be resumed quickly.

It is also preferable that the suction means 20 stop suction when suction is not necessary, such as while being moved to the position of the detected weeds 110. This makes it possible to reduce energy consumption. The suction means 20 is provided with backflow prevention means 50 that prevents the backflow of the sucked weeds 110 and water 100, so that even if suction is stopped, the sucked weeds 110 will not backflow back into the rice paddy. The backflow prevention means 50 is, for example, a valve that opens and closes depending on the water flow.

In the above embodiment, the flotation means 10 uses the submerged portion 11 to pull out the weeds 110 from the soil 120. However, the flotation means 10 may be configured to scrape the soil 120 and float the weeds 110 in the water by spraying air or the like at the soil 120 in the water. In this case, the flotation means 10 can float the weeds 110 in the water without touching the soil 120 or the weeds 110, so the weeds 110 are less likely to become entangled in the flotation means 10.

Next, a weeding device according to another embodiment of the present invention will be described. Note that the same functional members as those in the above embodiment are given the same reference numerals and the description thereof will be omitted.
FIG. 5 is a schematic diagram of the weed treatment means in this embodiment.
The weeding device of this embodiment is equipped with a mixer 30B for cutting weeds as a weed treatment means. The mixer 30B has a housing 31 arranged in a flow path through which the water 100 and weeds 110 sucked by the suction means 20 flow, and sharp cutting blades 32 arranged inside the housing 31. A plurality of cutting blades 32 are provided protruding from upstream to downstream on the outer periphery of a rotating rod 33 provided to penetrate the housing 31. The rotating rod 33 is rotated by a motor (not shown) or the like, and the cutting blades 32 also rotate accordingly. The rotating rod 33 and the cutting blades 32 may be rotated by utilizing a water flow.
The weeds 110 mixed in the water 100 sucked from one end of the pipe 21 of the suction means 20 are cut into small pieces by the rotating cutting blade 32 as they pass through the mixer 30B. The cut weeds 110 are returned to the paddy field together with the water 100 from the other end of the pipe 21. The soil particles 121 are also returned to the paddy field together with the water 100. In this way, by sucking up the weeds 110 suspended in the water and then cutting them into small pieces, it is possible to effectively prevent the weeds 110 from re-adhering. In addition, by returning the sucked water 100 to the paddy field, it is not necessary to perform new water management work associated with inflow and outflow. In addition, since there is no need to install a filter to remove the weeds 110 from the water 100, the effort required for filter regeneration or replacement can be saved.
In the mixer 30B shown in FIG. 5, the housing 31 is long horizontally and the rotating rod 33 is disposed horizontally, but the housing 31 may be long vertically and the rotating rod 33 may be disposed vertically.

10 Flotation means 11 Submersion section 12 Base section 12a Hole 12b Wall section 13 Support section 13a First ring section 13b Second ring section 13c Arm connection section 13d Cylinder section 13e Threaded section 13f Ball joint 13g Step section 14 Fixing nut 15 Rotation drive section 15a Rotation drive magnet 15b Rotation drive coil 16 Ball bearing 20 Suction means 21 Pipe 22 Ejector 23 High-pressure water piping 24 Nozzle 30 Weed treatment means 30A Filter 30B Mixer 31 Housing 32 Cutting blade 33 Rotating rod 40 Weed position detection means 41 Underwater camera 42 Detection section 50 Backflow prevention means 60 Robot arm 70 Tangle elimination means (rotation direction switching section)
100 Water 110 Weeds 120 Soil 121 Particles

Claims (10)

A weeding device for removing weeds from flooded rice paddies,
A floating means for separating the weeds from the soil and floating them in water;
a suction means for sucking the weeds suspended in the water together with the water;
a weed treatment means for capturing or cutting the weeds contained in the sucked water,
A weeding device which returns the water from which the weeds have been removed, or the water containing the cut weeds, to the paddy field. The weeding device according to claim 1, characterized in that the weed treatment means is a filter that is disposed in a flow path through which the water and weeds sucked by the suction means flow and that captures the weeds and their seeds. The weeding device according to claim 1, characterized in that the weed treatment means is a mixer having a cutting blade rotatably arranged in a flow path through which the water sucked by the suction means and the weeds flow, and cutting the weeds with the rotating cutting blade. The weeding device according to any one of claims 1 to 3, characterized in that the floating means has a sinking part that sinks into the soil, and the weeds are pulled out of the soil by rotating the sinking part and suspended in the water. The weeding device according to claim 4, characterized in that the recessed portion has a predetermined flexibility. The weeding device according to claim 4 or 5, characterized in that it is provided with an entanglement elimination means for removing the weeds entangled in the recessed portion. The weeding device according to claim 6, characterized in that the tangle-eliminating means includes a rotation direction switching unit that switches the rotation direction of the recessed portion. The weeding device according to any one of claims 1 to 7, characterized in that the suction means has a tube one end of which is inserted into the water and an ejector connected to the tube. The weeding device according to any one of claims 1 to 8, characterized in that it is provided with a weed position detection means for detecting the position of the weeds growing in the soil, and the floating means is moved to the detected position of the weeds. The weeding device according to claim 9, further comprising a backflow prevention means for preventing backflow of the weeds and water sucked into the suction means.