JP2021185895A - Weeder in paddy-like cultivated land - Google Patents

Abstract

To provide a weeder configured to stably eradicate weeds in paddy-like cultivated land, while reducing a burden of a worker.SOLUTION: A weeder 10 for eradicating weeds in paddy-like cultivated land formed by filling a muddy medium with water, causing crops to spread roots in the muddy medium and rearing the crops, includes a moving body 20 with a navigation device for navigating the paddy-like cultivated land, and a gas injection nozzle 30 for injecting gas from the moving body toward soil at the water bottom. The weeder 10 in the paddy-like cultivated land eradicates weeds by agitating the muddy medium by the gas injected from the gas injection nozzle.SELECTED DRAWING: Figure 1

Description

The present invention relates to a weeding device in a paddy field-like cultivated land for growing crops such as paddy rice in a muddy medium filled with water, and particularly to a weeding device in a paddy field-like cultivated land in which weeding is performed by a jet gas flow.

In rice cultivation, "medium-cultivation weeding" is performed in which the topsoil of the roots of vegetated rice plants is cultivated shallowly and weeding is performed at the same time. Such medium-cultivation weeding is carried out by moving a wheelbarrow-type weeder in the paddy field, or by navigating a passenger-type weeder with paddy pain, and further, navigating an unmanned navigation weeding device such as a boat in the paddy field. It is also done to make it.

Regarding weeding using an unmanned navigation weeding device such as a boat, the applicant of the present application has proposed Patent Document 1 (Japanese Unexamined Patent Publication No. 2007-151481). In Patent Document 1, a radio-controlled hovercraft that is equipped with a pesticide tank for filling a hovercraft body with a liquid pesticide or the like and a spraying device for spraying the pesticide, and can operate the spraying device and the hovercraft body by remote control. Proposes technology related to.

Further, in Patent Document 2 (Japanese Unexamined Patent Publication No. 2019-83708), it is a small robot for agricultural management of paddy fields, which is a hull, a propulsion device, a swivel device, and a water ejection device that ejects water toward the bottom of the water. And the control device that controls the propulsion device and the turning device based on the detection result of the environment detection device so that the hull can navigate in the paddy field while avoiding obstacles. A small hull-shaped robot has been proposed.

Further, in the past, regarding a paddy field weeder having a weeding function between strains, in Patent Document 3 (Japanese Unexamined Patent Publication No. 2008-22722), a weight member is provided at the tip of a gas ejector having at least a part of flexibility. We also propose a paddy field weeder in which a ejection hole is provided in the weight member. And in this document 3, the weeds to be removed are just before germination, or because the roots have not yet reached sufficiently, the soil surface of the rice field is stirred by the gas ejection such as air, and the weeds are separated from the soil, or the soil surface itself. Discloses that weeds are removed because the roots of the weeds soar into the water.

Japanese Unexamined Patent Publication No. 2007-151481 Japanese Unexamined Patent Publication No. 2019-83708 Japanese Unexamined Patent Publication No. 2008-22722

The above-mentioned Patent Document 1 proposes to use hovercraft for weeding paddy fields, but this hovercraft is intended for spraying pesticides and is not suitable for pesticide-free rice cultivation that does not use herbicides. Further, in Patent Document 2, it is proposed that a hull is used and water is sprayed toward the bottom of the water by a water ejection device to achieve weeding. It is also feared that the water ejection device may be clogged. In Patent Document 3, it is proposed to perform inter-strain weeding by ejecting a gas such as air, but a weeding rotor for weeding Jouma is required separately, and since it is a hand-push type weeder, the operator is in the paddy field. Had to move.

Therefore, the present invention solves the above-mentioned problems in the conventional technique, and while realizing rice cultivation without pesticides, it is possible to perform weeding work by unmanned operation without the need for workers to move in the paddy-like cultivated land. The first task is to provide a weeding device in a cultivated land.

The second aspect of the present invention is to provide a weeding device in a paddy-like cultivated land, which eliminates the clogging of the fluid used for weeding in the paddy-like cultivated land and enables stable weeding work. It is an issue of.

Furthermore, the third aspect of the present invention is to provide a weeding device in a paddy-like cultivated land that can prevent weeds from coming off while removing weeds when weeding with the injected gas. Make it an issue.

The present invention provides a weeding device in a paddy-like cultivated land that can perform weeding in a paddy field by effectively utilizing the force used for the navigation when a boat is used as an unmanned navigation weeding device. This is the fourth issue.

In the present invention, in order to solve at least one of the above problems, weeds can be weeded by using a moving body such as a boat that can navigate in a paddy field and injecting gas from the moving body. We provide a weeding device for paddy-like cultivated land.

That is, the weeding device in the paddy field-like cultivated land according to the present invention is a weeding device for removing weeds in the paddy field-like cultivated land where the crop is grown by filling the muddy medium with water and letting the muddy medium take root. It is equipped with a moving body equipped with a navigation device for navigating the paddy field-like cultivated land, and a gas injection nozzle for injecting gas from the moving body toward the soil at the bottom of the water, and is injected from the gas injection nozzle. Provided is a weeding device in a paddy field-like cultivated land, which removes weeds by stirring a muddy medium with a gas.

As the moving body, a moving body that can move on a paddy-like cultivated land formed by filling a muddy medium with water can be used, and a moving body that can float and move on the filled water, particularly preferably an air cushion boat. You can use a boat that includes. It is desirable that the mobile body can be navigated unmanned, and in addition to those capable of autonomous navigation, those that can be remotely controlled regardless of whether they are wired or wireless, in particular, those that can be remotely controlled by a wireless system such as radio control can be used. .. The moving body also includes a gas injection nozzle for injecting gas toward the muddy medium in the moving paddy-like cultivated land. In many cases, air sent by a blower such as a fan can be used as the gas, but air contained in a pressurized cylinder or a pressurized gas such as nitrogen, argon or oxygen can also be used.

In the weeding device in the paddy field-like cultivated land of the present invention, the gas ejected from the gas injection nozzle has a wind speed of 4.5 m / s or more and 8.0 m / s or less, particularly 5.0 m / s or more and 7.0 m. It is desirable that the wind speed is / s or less. Therefore, in the weeding device in the paddy field-like cultivated land of the present invention, the wind speed of 4.5 m / s or more and 8.0 m / s or less, particularly 5.0 m / s or more and 7.0 m / s or less, from the gas injection nozzle. It is desirable to provide a gas supply means for weeding that injects gas at the wind speed. It is desirable that the wind speed is approximately equal in the plurality of gas injection nozzles, and the wind speed of the gas ejected from at least one of the gas injection nozzles is twice the wind speed of the gas ejected from the other gas injection nozzles. Below, it is particularly desirable that it is 1.5 times or less. Further, it is desirable that the opening diameter of the gas injection nozzle is 3 mm or more and 13 mm or less, particularly 4 mm or more and 9 mm or less. By satisfying any or all of these requirements, the muddy medium can be effectively agitated by the air discharged from the gas injection nozzle, and a higher herbicidal effect can be obtained.

Further, it is desirable that the gas injection nozzle is present in the vicinity of the muddy medium or in the muddy medium in the paddy-like cultivated land. In particular, the gas injection nozzle may be present at a distance of 7 cm or less from the surface of the muddy medium, or 1 cm within the muddy medium, particularly within 3 cm, or 0.5 cm within the muddy medium. desirable. Therefore, it is desirable that the gas injection nozzle is provided with an injection port adjusting means for adjusting the gas injection position to a position where the distance from the surface of the muddy medium is within 7 cm or the position is 1 cm into the muddy medium. The injection port adjusting means can also be formed by a hose having a different interchangeable length, a stretchable tube, or the like.

The gas injection nozzle can be formed as a tip opening of a hose that guides gas, or can be formed as a detachable attachment nozzle at the tip opening. The attachment nozzle is an injection nozzle that narrows the opening diameter in order to increase the flow velocity of the guided gas, a diffusion nozzle that widens the opening diameter in order to diffuse the guided gas, and further, water is discharged by the flow of the gas. An ejector nozzle having an ejector effect for taking in and a spiral nozzle for discharging the guided gas as a vortex can be used. Further, a spiral protrusion may be formed on the inner surface of the hose that guides the gas, and the hose may be formed so as to be jetted from the opening at the tip of the hose (gas injection nozzle) as a vortex when flowing in the hose.

Further, the moving body may be various devices capable of moving in the paddy-like cultivated land, but preferably, an air cushion boat that ejects air at a high pressure toward the moving surface and floats and advances is used. The air cushion boat is provided with a navigation gas supply means for ejecting air that floats and / or moves the aircraft, and the air cushion boat is used as a weeding gas supply means for supplying gas to the gas injection nozzle. It is desirable to use the navigation gas supply means of. With such a configuration, it is not necessary to separately install a gas supply means for weeding, the manufacturing cost can be suppressed, the structure can be simplified, and the overall weight can be reduced. Further, if the gas used for the floating and moving of the air cushion boat and the injection from the gas injection nozzle is supplied by one fan, the manufacturing cost can be reduced and the weeding device can be simplified and reduced in weight. It will be more desirable.

As described above, when the navigation gas supply means is used or also used as the weeding gas supply means, at least the gas used for the floating and moving of the air cushion boat and the injection from the gas injection nozzle. It is also possible to provide a gas supply amount adjusting means for adjusting any of the supply amounts. The gas supply amount adjusting means can be performed by changing the opening area of the gas intake port output from the navigation gas supply means with a flap or the like, or by changing the opening area of the gas exhaust port.

Further, in the present invention, in order to solve at least one of the above-mentioned problems, weeds in the paddy field-like cultivated land where the crops are grown are removed by filling the muddy medium with water and letting the muddy medium take root. It is a weeding method. Provided is a method for weeding in a paddy-like cultivated land in which a weed device according to the present invention is navigated to remove weeds in the muddy medium.

In such a weeding method, weeding by the weeding apparatus according to the present invention is carried out within a period of 4 days or more and 15 days or less, particularly 7 days or less and 10 days or less after the crop is cultivated on the paddy-like cultivated land. It is desirable to do it in. This is to enhance the weeding effect of the weeding device in the paddy-like cultivated land and to prevent the vegetated seedlings from coming out.

The weeding device in the paddy field-like cultivated land according to the present invention includes a moving body provided with a navigation device for navigating the paddy field-like cultivated land, and a gas injection nozzle for injecting gas from the moving body toward the soil at the bottom of the water. Since it is configured to remove weeds by stirring the muddy medium with the gas ejected from the gas injection nozzle, there is no need to use pesticides such as herbicides. It is possible to realize rice cultivation with pesticides. In addition, if the moving object is capable of autonomous navigation or can be remotely controlled regardless of whether it is wired or wireless, the worker can control it from outside the paddy-like cultivated land. Can be used as a weeding device in paddy-like cultivated land, which can perform weeding work by unmanned operation without having to move in the paddy-like cultivated land.

Further, since the weeding device in the paddy field-like cultivated land of the present invention can perform weeding using the gas ejected from the gas injection nozzle, it is not affected by foreign substances in the water stretched on the paddy field-like cultivated land. It can be used as a weeding device in paddy field-like cultivated land that can eliminate clogging of gas and perform stable weeding work. Furthermore, since the muddy medium is agitated by the gas ejected from the gas injection nozzle to perform weeding, air can be sent into the muddy medium and water during the agitation, which also contributes to the growth of vegetated crops. can do.

Then, in the weeding apparatus in the paddy field-like cultivated land according to the present invention, the wind velocity from the gas injection nozzle is 4.5 m / s or more and 8.0 m / s or less, particularly 5.0 m / s or more and 7.0 m / s or less. If a gas supply means for weeding that injects gas at the wind speed of is provided, it is possible to prevent weeds from coming off while removing weeds when weeding with the injected gas. It can be used as a weeding device in cultivated land. As a result, by navigating the weeding device in the field, weeds growing between the vegetated seedlings can be weeded, and a so-called inter-strain weeding can be performed as a weeding device in a paddy-like cultivated land. ..

Further, when a boat, particularly an air cushion boat, is used as the moving body, and a navigation gas supply means used for floating and / or moving the air cushion boat is used or also used as the mowing gas supply means. It can be used as a weeding device in paddy field-like cultivated land that can weed in paddy fields by effectively utilizing the force used for navigation.

In the weeding method in the paddy field cultivated land according to the present invention, after the crop is cultivated in the paddy field cultivated land, within a period of 4 days or more, 15 days or less, preferably 7 days or less and 10 days or less. Since the weeds of the muddy medium are removed by navigating the weeding device of the present invention in the paddy field-like cultivated land, the worker can easily and efficiently weed the paddy field without entering the paddy field-like cultivated land. It is possible to carry out the work, perform inter-strain weeding while preventing the withdrawal of rice seedlings, and further blow air into water and muddy medium to support the growth of crops.

A side view showing a weeding device in a paddy-like cultivated land according to the first embodiment. Rear view of the weeding device according to the first embodiment Bottom view of the weeding device according to the first embodiment Vertical sectional view showing an embodiment of a gas injection nozzle (A) side view, (B) plan view, (C) rear view, (D) front view of the weeding device according to the second embodiment. (A) side view, (B) plan view showing the weeding apparatus according to the third embodiment. A plan view showing (A) a test body and a schematic view showing (B) a test method in Examples.

Hereinafter, the weeding device 10 in the paddy-like cultivated land according to the present embodiment will be specifically described with reference to the drawings. In particular, the weeding device 10 according to the present embodiment is suitable for weeding in a paddy field, and shows a weeding device 10 using a boat as a moving body 20, but the weeding device 10 is not limited to this. Of course, it is also possible to embody what can be used in the cultivated land of the above, and the weeding device 10 using the moving body 20 other than the boat.

FIG. 1 is a side view showing a mowing device 10 in a paddy-like cultivated land according to the first embodiment, FIG. 2 is a rear view of the mowing device 10, and FIG. 3 shows a bottom view of the mowing device 10. ing. In FIGS. 2 and 3, the skirt described later is omitted. In particular, the weeding device 10 according to the first embodiment uses an air cushion boat as a moving body 20 that moves in a paddy field, and the air cushion boat 20 is formed so that it can be remotely controlled by radio control. ..

The air cushion boat 20 includes a hull 28 having a plurality of exhaust ports 21 on its side surface, a fan 22 that floats the hull 28 during navigation and sends wind for propulsion, and an engine 23 that drives the fan 22. It is provided with a navigation device including a rudder 24 that changes the blowing direction of the fan 22 in order to change the traveling direction, and a skirt 27 that inflates by taking in the gas injected from the exhaust port 21. Of course, the air cushion boat 20 as the moving body may have other configurations, and an air flow that floats and propels the hull 28 is sent by a blower, or a motor is used to drive the fan 22. You can also do it. Further, the air flow for floating the hull 28 and the air flow for propelling the hull 28 may be performed by different fans 22 or blowers, and the formation position of the exhaust port 21 provided on the hull 28 may be arbitrarily changed.

In particular, in the weeding device 10 according to the present embodiment, the air flow supplied from the fan 22 is divided into one toward the rudder 24 and one toward the inside of the ship. That is, the component toward the air intake port existing in the traveling direction of the air flow blown from the fan 22 enters the internal space of the hull 28, and this is used to levitate the hull 28. On the other hand, the components that did not enter the air intake will be used for propulsion (and for weeding) toward the rudder 24. By adjusting the amount of air distributed, the amount of air used for levitation, propulsion, and weeding of the hull can be adjusted. Therefore, it is desirable to provide a gas supply amount adjusting means such as a variable wing that controls the distribution amount of the air flow. Further, the gas supply amount adjusting means can also control the distribution of the amount of air used for floating the hull and the amount of air used for weeding ejected from the gas injection nozzle.

In the weeding device 10 according to the present embodiment, a hose 31 for discharging the supplied air toward the muddy medium of the paddy field is provided at the exhaust port 21 existing on the rear side of the air cushion boat 20 described above. It is attached, and the tip of the hose 31 is a gas injection nozzle 30. With this configuration, the air flow supplied from the fan 22 and entering the hull 28 from the air intake port is used to float the hull 28, and a part thereof is passed through the hose 31 to the gas injection nozzle 30. Will be sprayed from.

In the present embodiment, the hose 31 forming the gas injection nozzle 30 is provided in a part of the exhaust port 21 existing on the rear side in the traveling direction of the air cushion boat 20, and the hose 31 is not provided in the exhaust port 21. 21 can be used to levitate the hull 28 as before. That is, in the weeding device 10 according to the present embodiment, at least a part (preferably a part on the rear side) of the exhaust port 21 for levitation in the air cushion boat 20 used as a moving body is the gas injection. It is used to form the nozzle 30. The number and ratio of the exhaust ports 21 forming the gas injection nozzle 30 (that is, providing the hose 31) can be appropriately adjusted depending on the amount of air for floating the hull 28 and the amount of air required for weeding. In the present embodiment, about half of the exhaust ports 21 formed on the rear side of the hull 28 are used as the exhaust ports 21 for forming the gas injection nozzle 30 (that is, providing the hose 31). According to the air cushion boat 20 formed as described above, the original levitation force can be secured and the navigation in the paddy field can be performed. Further, the exhaust port 21 provided with the hose 31 may be provided with an attachment 25 for inserting the hose into the exterior or the hose, so that the hose can be easily attached. Such an attachment can be formed, for example, by a tube inserted into the exhaust port 21 and exteriorizing the hose.

Further, in the weeding apparatus 10 according to the present embodiment, it is desirable that the hose 31 is made of a material having flexibility enough to be deformed when it comes into contact with a rice plant vegetated in a paddy field. The hose 31 can be formed by using a metal or a hard resin, but in that case, when the air cushion boat 20 is navigated and the weeding work is performed, the vegetated rice plant is extracted. Therefore, it is desirable that the hose 31 has enough flexibility to be deformed when it collides with a rice plant.

Further, the gas injection nozzle 30 secured at the tip of the hose 31 is located at a distance of 7 cm or less from the surface of the muddy medium or 1 cm into the muddy medium, particularly within 3 cm, or 0 in the muddy medium. It is present at a position that is 5.5 cm deep. Therefore, it is desirable that the length of the hose 31 can be adjusted. In particular, it is desirable that the length of the hose 31 is appropriately adjusted according to the water volume of the paddy field, or that the hose 31 having a different length is attached.

The gas injection nozzle 30 secured on the hull 28 of the hose 31 has a wind speed of 4.5 m / s or more and 8.0 m / s or less, particularly 5.0 m / s or more and 7.0 m / s or less. It is desirable to inject a gas. Therefore, in the weeding device 10 according to the present embodiment, the wind speed is adjusted according to the number of the gas injection nozzles 30 (that is, the total opening area). However, the wind speed of the gas ejected from the gas injection nozzle 30 adjusts the output of the fan 22 or the amount of air supplied from the fan 22 (for example, the distribution ratio), or the opening diameter or opening of the gas injection nozzle 30. It can also be done by adjusting the area.

Further, it is desirable that the gas injection nozzle 30 provided at the tip of the hose 31 is formed so as to inject gas into the muddy medium at an intersection angle Θ in the range of 75 ° or more and 90 ° or less. It is conceivable to form the gas injection nozzle 30 so as to inject gas into the muddy medium at an crossing angle Θ of less than 75 °, but in this case, in relation to the propulsion movement of the air cushion boat 20. This is because it becomes difficult to sufficiently stir the muddy medium, and effective weeding work becomes difficult.

According to the weeding device 10 according to the present embodiment formed as described above, the fan 22 originally provided in the air cushion boat 20 for levitation and propulsion is used, and one of the gases blown from the fan 22 is used. The portion can be sprayed onto the mud medium of the paddy field. As a result, the muddy medium is agitated and weeds growing on it can be removed. In particular, according to the weeding device 10 according to the present embodiment, one fan 22 can secure an air flow for levitation, propulsion, and weeding of the air cushion boat 20, so that the configuration can be simplified. It can also be made lighter.

In the weeding device 10 according to the present embodiment, the gas injection nozzle 30 is secured at the tip of the hose 31, but the gas injection nozzle 30 may be another embodiment. For example, it is also possible to guide the air flow supplied from the fan 22 by a hose 31 or a duct, and form a gas injection nozzle 30 at the tip thereof to inject gas in a band shape in a direction intersecting the traveling direction of the air cushion boat 20. .. Further, a plurality of openings that open toward the muddy medium may be formed on the bottom surface of the hull 28, and the openings may be used as the gas injection nozzle 30. At that time, when the exhaust port 21 formed on the side surface of the hull 28 is closed and the exhaust port 21 is formed on the entire bottom surface, the exhaust port 21 contributes to the floating of the air cushion boat 20 and weeding. Can be done. In this case, the hose 31 and the like can be eliminated.

In addition to using the tip opening of the hose 31, the gas injection nozzle 30 can be formed as a detachable attachment nozzle at the tip opening. FIG. 4 is a vertical sectional view showing an embodiment of the gas injection nozzle 30. The gas injection nozzle 30 uses the tip opening of a general hose 31, and also has a tip opening 31a of a spiral hose provided with a spiral protrusion 32 on the inner peripheral surface of the hose 31 as shown in FIG. 4 (A). can do. Further, as shown in FIG. 4B, a spiral nozzle 31b (that is, an attachment nozzle) having a spiral protrusion 32 on the inner surface can be attached to the tip opening of a general hose 31. When these gas injection nozzles 30 are used, the guided gas can be discharged in a spiral direction in a spiral direction, so that the effect of expanding sales of the muddy medium can be enhanced. Further, as shown in FIG. 4C, the gas injection nozzle 30 uses a discharge nozzle 31c (that is, an attachment nozzle) whose opening diameter is narrowed so that the gas can be discharged not only in the traveling direction but also to the side. Further, as shown in FIG. 4D, a diffusion nozzle 31d having a wide opening diameter can be used to diffuse the guided gas. Further, although not shown, it is also possible to use an ejector nozzle that takes in and discharges surrounding water by increasing the flow velocity of the gas.

Next, with reference to FIG. 5, the weeding device 10 in the paddy-like cultivated land according to the second embodiment will be specifically described. FIG. 5 shows (A) a side view, (B) a plan view, (C) a rear view, and (D) a front view of the weeding device 10 according to the second embodiment. The weeding device 10 according to this embodiment uses a hull 28 configured to float on a paddy field. The hull 28 is equipped with a drive device such as an engine 23 or a motor and a fan 22 that is rotationally driven by the drive device 23 for propulsion (hereinafter, these are referred to as "propulsion mechanism 26"). That is, it differs from the air cushion boat 20 in that it does not require an air flow for levitation. In this embodiment, the drive device 23 and the fan 22 are used as the propulsion mechanism 26, but other blowers may be used.

The hull 28 can be formed so as to float on the water surface by using a resin such as foamed resin, wood, or the like, and even if at least the propulsion mechanism 26 (drive device 23, fan 22, etc.) is loaded, the hull 28 floats on the water surface. It is formed by the buoyancy that can be done. Further, the bottom surface is preferably formed as a smooth surface without unevenness. This is to prevent the vegetated rice plants from being pulled out while navigating the paddy fields. Although the hull 28 is formed in the shape of a ship in the present embodiment, it does not necessarily have to be in the shape of a ship and may be a quadrangular or circular plate.

The hull 28 is provided with a propulsion mechanism 26. The weeding device 10 according to the present embodiment is configured so that a part of the air flow output from the propulsion mechanism 26 can be used for weeding. That is, a gas is provided on the downstream side of the air flow discharged from the propulsion mechanism to take in the air flow, and the air taken in from the air intake 51 is ejected toward the muddy medium. It is formed so as to include an injection nozzle 30. More specifically, a duct 52 forming an air intake port is provided on the downstream side of the propulsion mechanism 26, and a hose 31 provided with a gas injection nozzle 30 on the tip side of the gun is connected to the lower surface of the rear end of the duct. is doing.

In the weeding device 10 formed in this way, by driving the propulsion mechanism 26 when the hull 28 is navigating, the air intake port of the duct existing on the downstream side of the air flow sent out from the propulsion mechanism 26 takes in the air flow. Can be discharged from the gas injection nozzle 30 of the hose 31 that protrudes from the bottom surface of the hull 28 and extends. As a result, by navigating the weeding device 10 in the paddy field to be weeded, the muddy medium is agitated by the jetted air flow, and weeds growing from the muddy medium can be removed.

FIG. 6 is a side view (A) and a plan view (B) showing the weeding device 10 according to the third embodiment. The weeding device 10 according to this embodiment is for weeding that outputs an air flow for weeding, in addition to the propulsion mechanism 26 (hereinafter, also referred to as “navigation gas supply means”) in the second embodiment. The weeding device 10 is provided with the gas supply means 61. The weeding device 10 according to this embodiment can be attached to an existing boat and can therefore be provided as a weeding module for the gas flow weeding device 10.

The weeding device 10 according to the present embodiment includes a boat main body provided with a propulsion mechanism 26 (that is, "navigation gas supply means") on the hull 28, and a weeding module 60 attached to the boat main body. The existing boat body can be used, and as shown in the first embodiment, the one propelled by the air flow from the fan 22, the one using another blower, and the screw or the water wheel type. The outer ring may be provided as the propulsion mechanism 26.

The weeding module is composed of a weeding gas supply means 61 composed of a fan 22 driven by a drive device 23 such as an engine or a motor, and a hose or a duct for guiding an air flow output from the weeding gas supply means 61. The flow path 62 is composed of a flow path 62 and a gas injection nozzle 30 provided on the downstream side of the flow path 62. In particular, in the present embodiment, the gas injection nozzle 30 is formed at the tip of a hose 31 connected to the flow path 62. However, the flow path 62 is not always necessary, and the mowing gas supply means 61 can be installed on the rear side of the hull 28, and air is directly sent from the mowing gas supply means 61 to the gas injection nozzle 30. If the flow can be output, the flow path 62 may be omitted.

It is desirable that the flow path is formed in a shape and an inner diameter that does not attenuate the air flow according to fluid dynamics, and the air flow is distributed so that the air can be injected from the gas injection nozzle 30 at a uniform wind speed. It is also possible to provide a constituent member for this purpose.

According to the weeding device 10 formed as described above, the hull 28 is navigated by the navigation gas supply means (that is, the propulsion mechanism 26 as the navigation device) provided on the hull 28, and the weeding gas supply means 61. The air flow supplied from the gas jet nozzle 30 can be jetted onto the muddy medium to stir the muddy medium. As a result, weeds growing in the muddy medium are also extracted into the water, so that the paddy field can be weeded.

Experimental Example 1

In this experiment, the output of the air flow in the weeding device 10 using the air cushion boat 20 was confirmed. Specifically, in the air cushion boat 20 shown in the first embodiment, the wind pressure of the gas ejected from the gas injection nozzle 30 was confirmed. The air cushion boat 20 used in this experiment uses an engine 23 with an output of 2.4 ps, and has 49 circular exhaust ports 21 having an opening diameter of 20 mm all around the side surface of the hull 28, and is provided on the rear side. A tube was attached to 6 exhaust ports 21 out of all 11 exhaust ports 21 provided in the above, and the tip opening thereof was used as a gas injection nozzle 30. Then, the wind speed was confirmed using an anemometer (HOLDPEAK 826A).

As a result, the wind speed of the air flow output from each gas injection nozzle 30 was 6.0 to 7.0 m / s. Therefore, it was confirmed that the wind pressure was 22.05 to 30.01 Pa under the standard atmosphere (1.225 kg / m ^{3) environment.}

Experimental Example 2

In this experiment, the weeding effect of air flow was confirmed. Specifically, three test specimens shown in FIG. 6 (A) were prepared, and in a test site prepared by filling water on a muddy medium or sand in the same manner as in paddy-like cultivated land, 3 while changing the water volume. The depth of the ditch formed on the bottom of the paddy-like cultivated land in one test piece was confirmed. In this experiment, the weeding work in the paddy field is generally to stir the muddy medium to a depth of about 5 mm to 10 mm in order to weed the weeds such as Pontederia vaginalis, Awa, and Japanese millet, and these weeds. It was confirmed that if the seedlings could be removed, a sufficient weeding effect could be obtained in the subsequent raising of seedlings, and therefore the depth of the groove formed on the bottom of the paddy-like cultivated land was confirmed.

The test piece used is as shown in FIG. 7. The test piece 1 and 2 are provided with seven gas injection nozzles 30 on each side of the pipe having an inner diameter of 30 mm and a length of 1,120 mm, and the test piece 3 is provided with five gas injection nozzles 30 on each side. The gas injection nozzles 30 are provided. Then, in the test piece, the gas injection nozzle 30 (nozzle 1) at the position closest to the air flow inlet, the gas injection nozzle 30 (nozzle 3) at the position farthest from the air flow inlet, and the nozzle 1 and the nozzle. The flow velocity of the gas flow ejected from the gas injection nozzle 30 (nozzle 3) located in the middle of 2 was measured. The structure of each test piece and the wind speed of each nozzle are shown in Table 1 below. The wind pressure in the table is a value calculated from the wind speed based on the density of the standard atmosphere.

Using the above test specimens 1 to 3, eject from the gas injection nozzle 30 of each test specimen while changing the water volume in a test site prepared by filling water on a muddy medium or sand in the same manner as in paddy field-like cultivated land. An experiment was conducted on how deep a groove was formed by the resulting gas. In this experiment, the bottom surface, which is the medium, was tested on muddy soil and sand, respectively. Further, in the experiment, as shown in FIG. 6B, the experiment was carried out in a state where the bottom surface of the pipe to which the nozzle was attached in each test piece was fixed at a position in contact with the water surface. The results are shown in Table 2 below.

From the above experimental results, it was confirmed that the bottom medium can be agitated even in a paddy field-like cultivated land with a water depth of 90 mm by setting the wind speed of the gas injected from the gas injection nozzle 30 to 5 m / s or more. Further, as is clear from the experimental results of the test body 3, even if the gas injection nozzle 30 is brought close to the medium, it is difficult to sufficiently stir the medium when the wind speed is less than 4.5 m / s. It was confirmed. In addition, the results of the test piece 3 confirmed that it is also important that the wind speeds of the gas injected from each nozzle are uniform.

Further, the wind velocity of the gas output from each of the gas injection nozzles 30 in the test bodies 1 and 2 is output from the gas injection nozzle 30 in the weeding apparatus 10 shown in the first embodiment confirmed in the experimental example 1. Since the wind velocity is approximately the same as that of the gas, it was confirmed that the weeding device 10 shown in Experimental Example 1 can perform the weeding work in the paddy field.

The weeding device in the paddy-like cultivated land of the present invention can be used especially for the weeding work in the paddy field. In addition, since the weeding device can efficiently agitate soil such as a field, it can also be used for plowing work such as medium plowing work.

10 Weeding device 20 Mobile body (air cushion boat)
21 Exhaust port 22 Fan 23 Drive device (engine)
24 Rudder 25 Attachment 26 Propulsion mechanism 27 Skirt 28 Hull 30 Gas injection nozzle 31 Hose 60 Weeding module 61 Weeding gas supply means 62 Flow path

Claims (5)

It is a weeding device that removes weeds in paddy-like cultivated land where crops are grown by filling water on the muddy medium and rooting it in the muddy medium.
A mobile body equipped with a navigation device for navigating paddy-like cultivated land,
It is equipped with a gas injection nozzle that injects gas from the moving body toward the soil at the bottom of the water.
A weeding device in a paddy-like cultivated land, characterized in that weeding is removed by stirring a muddy medium with a gas ejected from the gas injection nozzle.
It is equipped with a gas supply means for weeding that injects gas from the gas injection nozzle at a wind speed of 4.5 m / s or more and 8.0 m / s or less.
The weeding apparatus in a paddy field-like cultivated land according to claim 1, wherein the gas injection nozzle is located within a distance of 7 cm from the surface of the muddy medium or at a position where the gas injection nozzle is 0.5 cm into the muddy medium.
The third aspect of the present invention, wherein the moving body is an air cushion boat, and the navigation gas supply means used for floating and / or moving the air cushion boat is used as the weeding gas supply means. Paddy-like weeding equipment in cultivated land.
The moving body is an air-cushion boat, and the gas used for the floating and moving of the air-cushion boat and the injection from the gas injection nozzle is supplied by one fan.
The paddy-like cultivated land according to claim 3, further comprising a gas supply amount adjusting means for adjusting at least the supply amount of any of the gases used for floating, moving, and injecting from the gas injection nozzle. Weeding equipment in.
It is a weeding method that removes weeds in paddy-like cultivated land where crops are grown by filling water on the muddy medium and rooting it in the muddy medium.
After cultivating crops on the paddy field-like cultivated land, within a period of 2 days to 7 days, the weeding device according to any one of claims 1 to 4 is navigated on the paddy field-like cultivated land. A method for weeding in a paddy-like cultivated land, which comprises removing weeds from the muddy medium.

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