Seeder and seeding method

Abstract

Provided are a seeding machine and a seeding method with which a travel position can be easily ascertained and seeds can be sown at a predetermined position even in a field that is flooded.　A seeding machine 1, 9, 10, 12, 13, 16 includes a base body 2 supported on wheels 3, 3R, 3L, 4R, 4L configured to be capable of traveling in a field that is flooded, the base body 2 being provided with a seeder 5 that sows seeds in the field. The seeding machine includes a position detection device 6, 15 provided on the base body 2, which uses at least one of the following as a guide and engages with the guide: ruts formed in the field by wheels 3, 3R, 3L, 4R, 4L, water channels formed in advance in the field, linear grooves formed in advance in the field, and a flexible linear body 14 stretched in advance in a straight line on the field.

Description

[Technical field]

[0001] The present invention relates to a seeder and a method for sowing seeds in a field, and more particularly to a seeder and a method for sowing seeds at regular intervals in a flooded field. [Background technology]

[0002] With the aging of agricultural workers and the globalization of agricultural product distribution, labor saving in agricultural work and reduction of agricultural production costs have become issues to be resolved. To resolve these issues, for example, in rice cultivation, direct seeding, in which seeds are directly sown in fields (hereinafter sometimes referred to as paddy fields) is becoming more widespread in order to save the labor of raising seedlings and transplanting. Among direct seeding methods, Patent Document 1 describes an example of a manufacturing method for iron powder-coated rice seeds used in the flooded direct seeding method, in which seeds are directly sown in a flooded field. The iron powder-coated rice seeds are composed of rice seeds coated with iron powder, which has a high specific gravity, and therefore tend to sink in water. Therefore, in the flooded direct seeding method, the use of the seeds described in Patent Document 1 has attracted attention because it has the advantages of preventing or suppressing the floating or flowing out of seeds in flooded paddy fields and preventing or suppressing bird damage.

[0003] Patent Document 2 describes an example of a flooded direct seeder that sows seeds in a flooded field, and the flooded direct seeder is configured to prevent dirt on the power transmission part from mud scattered from the field when traveling in the field. Patent Document 3 describes a seeder that can control the burial depth of seeds in a flooded rice field. Patent Document 4 describes a seeder equipped with a rotary puddling device called a harrow device that enables flooded direct seeding. Patent Document 5 describes an autonomous driving system for a work vehicle that acquires position information of a work vehicle such as a rice transplanter based on radio waves received from a positioning satellite of the Global Navigation Satellite System (GNSS) and uses the position information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4441645 [Patent Document 2] JP 2013-21943 A [Patent Document 3] Patent No. 6559978 [Patent Document 4] JP 2021-180650 A [Patent Document 5] Patent Publication No. 2022-111121 Summary of the Invention [Problem to be solved by the invention]

[0005] When a seeder is driven through a flooded paddy field to perform row or spot seeding, the track marks formed by the seeder as it drives through the paddy field and the lines formed by a marker may be used as a guide for the running position of the seeder. However, in the flooded direct seeding method, the track marks and lines are located below the water surface and are difficult to see, making it difficult to grasp the running position of the seeder, and therefore difficult to sow seeds in the specified position. In addition, when mud is stirred up by the running of the seeder, it becomes even more difficult to confirm the track marks and lines, and therefore it becomes even more difficult to sow seeds in the specified position. Therefore, in the past, in order to sow seeds in the specified position in a flooded paddy field, it was necessary to drain the water once to expose the soil surface of the paddy field. In addition, when the soil of the paddy field is exposed by draining the water, weeds may grow in the drained paddy field or weeds may easily grow, which may impair the above-mentioned advantages of the flooded direct seeding method. Therefore, after sowing in a flooded paddy field, it was necessary to quickly rehydrate the paddy field. In other words, in the past, even if the iron powder coated rice seeds described in Patent Document 1 were used in the flooded direct seeding method, it was necessary to drain and rehydrate the water, and this required extra water resources to be used, so there was still room for improvement in these respects.

[0006] Furthermore, even when row or spot seeding is performed in a flooded paddy field using the flooded direct seeder described in Patent Document 2 or the seeder described in Patent Document 3 or Patent Document 4, the water must be drained in order to check the running position of the flooded direct seeder or the seeder and sow in the specified position. Therefore, there are the same problems as those in Patent Document 1 mentioned above.

[0007] For example, if the autonomous driving system described in Patent Document 5 is installed in a seeder that sows seeds in a flooded field, and if a situation occurs in which the system is unable to receive signals from a positioning satellite, the position of the seeder cannot be identified, and there is a possibility that the seeder may sow seeds in areas that have already been sown, or that some areas may remain unsown. As a result, there is a possibility that the system may not be able to sow seeds regularly over the entire field.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide a seeder and a sowing method that allow the travelling position to be easily grasped even in a flooded field, and that enables seeds to be sowed in a specified position. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides [1] A seeder having a base supported by wheels configured to be capable of running through a flooded field, and a seeder for sowing seeds in the field, wherein at least one of the following is used as a guide: a rut formed in the field by the wheels, a waterway formed in advance in the field, a linear groove formed in advance in the field, and a flexible linear body pre-stretched in a straight line in the field, and the seeder is equipped with a position detection device provided on the base that engages with the guide. [2] The seeder described in [1], wherein the position detection device uses at least one of the following as a guide: ruts formed in the field by the wheels, a waterway pre-formed in the field, and a linear groove pre-formed in the field, and deforms in the left-right direction or oscillates in the left-right direction as the base moves in the left-right direction relative to the guide in the direction of travel. [3] A seeder described in [2], wherein the position detection device is configured in a rod shape, and a support mechanism configured to support the position detection device with a predetermined distance between the position detection device and the base in the left-right direction is provided on the base. [4] The seeder described in [1], wherein the position detection device uses a flexible linear body that is pre-stretched in a straight line in the field as a guide, and is engaged with the linear body so as to be movable relative to the linear body. [5] The seeder described in [4], wherein the position detection device has either a slit configured to engage the linear body so as to be able to move relative to one another, or a hole formed through the position detection device in the thickness direction so as to engage the linear body so as to be able to move relative to one another. [6] The seeder according to [1], further comprising a position information acquisition device that acquires position information based on a signal acquired from a satellite positioning system. [7] A sowing method for sowing seeds using a sowing machine described in any one of [1] to [5]. [8] The seeds are coated with a seed coating agent containing a metal material and have a specific gravity of 1.2 g / cm 3 More than 4.0g / cm 3 The sowing method described in [7] below. Effect of the Invention

[0010] According to the present invention, in a flooded field, at least one of the ruts formed by the wheels of the seeding machine, a waterway formed in advance in the field, a linear groove formed in advance in the field, and a flexible linear body stretched in a straight line in the field is used as a guide. When the seeding machine is made to travel along the guide, a position detection device is engaged with the guide. When the seeding machine is traveling along the guide, the position detection device moves together with the seeding machine while maintaining a substantially constant distance from the guide, so it does not deform or swing in the left-right direction relative to the traveling direction. Alternatively, such deformation or swing is smaller than when the seeding machine moves in the left-right direction to approach and move away from the guide. In contrast, when the seeding machine moves in the left-right direction to approach and move away from the guide, the distance between the guide and the position detection device changes, and the position detection device deforms or swings in the left-right direction accordingly. Therefore, the current position of the seeding machine relative to the guide in the left-right direction can be grasped based on the amount of deformation and the magnitude of swing of the position detection device. That is, it is possible to determine whether or not the seeder is traveling along the guide. When the seeder travels using the linear body as a guide, as the seeder moves left or right relative to the direction of travel, the linear body bends at the point where the linear body engages with the position detection device. The position of the seeder relative to the linear body can be determined from the bending angle of the linear body. As a result, even in a flooded field, the seeder can be made to travel along the guide and seeds can be sown in a specified position. In addition, since the position detection device is provided on the base of the seeder, it is easy to determine the traveling position of the seeder in the left or right direction relative to the guide and to correct the traveling position of the seeder. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of a seed sowing machine according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the seeding machine shown in FIG. [Diagram 3] 11A and 11B are diagrams for explaining the deflection deformation of the position detection device accompanying the movement of the seed drill in the left-right direction. [Figure 4]FIG. 11 is a diagram showing an example of a seeding machine according to a second embodiment of the present invention. [Diagram 5] FIG. 5 is a side view of the seed sowing machine shown in FIG. [Figure 6] FIG. 11 is a diagram showing an example of a seeding machine according to a third embodiment of the present invention. [Figure 7] FIG. 7 is a side view of the seed sowing machine shown in FIG. [Figure 8] FIG. 11 is a diagram showing an example of a seeding machine according to a fourth embodiment of the present invention. [Figure 9] FIG. 9 is a side view of the seed sowing machine shown in FIG. 8. [Figure 10] FIG. 13 is a diagram showing an example of a seeding machine according to a fifth embodiment of the present invention. [Figure 11] FIG. 11 is a side view of the seed sowing machine shown in FIG. [Figure 12] FIG. 11 is a diagram showing an example of a seeding machine according to a third embodiment of the present invention. [Figure 13] FIG. 13 is a side view of the seed sowing machine shown in FIG. [Figure 14] FIG. 1 is a diagram for explaining the state in which seeds are regularly sown over the entire field. [Figure 15] FIG. 1 is a diagram for explaining a state in which seeds are not sown regularly over the entire field. [Figure 16] FIG. 13 is a diagram showing an example of a seed sowing machine according to a seventh embodiment of the present invention. [Figure 17] FIG. 17 is a side view of the seeder shown in FIG. 16. [Figure 18] FIG. 2 is a diagram illustrating an example of a configuration of a mobile terminal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described. The seeding machine according to the embodiment of the present invention is configured to travel using a groove-like rut or waterway (open channel) formed in a flooded field, a line formed in the field by a conventionally known marker, a linear groove, a flexible linear body stretched in a straight line in advance in the field, and the like as a guide for the travel position in the field. That is, it is configured to travel as a guide. Also, the seeding machine according to the embodiment of the present invention is configured to sow seeds while traveling along a guide in a flooded field. Specifically, the above seeding machine includes, as main components, wheels configured to be able to travel in a flooded field, a base supported by the wheels, a seeder provided on the base and configured to sow seeds in the field along the traveling direction, and a position detection device that detects the travel position of the seeding machine in the left-right direction relative to the guide. That is, the seeding machine according to the embodiment of the present invention is configured to travel and sow seeds while detecting the current travel position relative to the guide in the left-right direction when traveling along a guide in a flooded field. The above-mentioned seeding machine may be either a powered type equipped with a driving power source that outputs power for traveling, or a manual type that does not have a driving power source. In addition, there is no restriction on the wheels configured to be able to travel in the above-mentioned flooded field as long as they can travel in a paddy field.

[0013] (First embodiment) (Seeding machine) FIG. 1 is a diagram showing an example of a sowing machine according to the first embodiment of the present invention. The sowing machine 1 shown in FIG. 1 is a manual four-wheel type sowing machine 1, in which left and right front wheels 3R, 3L are provided on the front side of the base body 2 in the traveling direction of the sowing machine 1, and left and right rear wheels 4R, 4L are provided on the rear side of the base body 2 in the traveling direction. The base body 2 is supported by those wheels 3R, 3L, 4R, 4L, and a seeder 5 is provided on the base body 2. The sowing machine 1 may have a driving force source that generates a driving force for traveling. In addition, a steering device (not shown) may be provided at the rear of the sowing machine 1, and the operator may be able to change the traveling direction of the sowing machine 1 by operating the steering device. However, if the traveling direction of the sowing machine can be controlled without the steering device, a special steering device such as a steering wheel is not essential.

[0014] The seeder 5 may be a conventionally known seeder. In the example shown in FIG. 1, the seeder 5 is preferably configured to operate in conjunction with the rotation of the front wheels 3R, 3L and the rear wheels 4R, 4L when the seeding machine 1 travels in the field, and to perform any one of spot seeding, row seeding, and broadcast seeding. Specifically, the seeder 5 may be, for example, a drum seeder configured to have seeds filled inside a cylindrical container (not shown) and to drop the seeds from holes formed in the container in the plate thickness direction to sow at regular intervals. Alternatively, the seeder 5 may be a broadcaster that includes a seed storage section (not shown) and sows the seeds supplied from the storage section by flicking them off with the rotation of a rotor (not shown). Furthermore, the seeder 5 may be a seeder that includes a measuring device (not shown) and is configured to sow the seeds measured by the measuring device in the field. Alternatively, the seeder 5 may be a seeder that is configured to sow seeds in the field using magnetic force, centrifugal force, or the like. The seeder 5 may also be a seeder equipped with a motor (not shown) and configured so that the timing of sowing can be freely controlled by the motor without being linked to the wheels 3R, 3L, 4R, and 4L. The seeder 5 may be configured so that when the seeder 1 travels in the field, it sows seeds in the field in conjunction with the travel of the seeder 1.

[0015] For the sake of simplicity, the number of rows for spot seeding and row seeding is shown as two in FIG. 1, but it is of course possible to use a device configuration with more than two rows. For example, 3 to 20 rows. As long as there are no operational problems, more than 20 rows is acceptable and falls within the scope of the present invention. There is no particular limit to the width of the scattering, and it can be about 0.1 to 10 meters as long as there are no operational problems.

[0016] (Position detection device and support mechanism) A position detector 6 configured to engage with the above-mentioned guide is provided on the front side of the base 2 in the travel direction of the sower 1. In the example shown in FIG. 1, the position detector 6 is configured in a rod shape and is supported on the base 2 via a support mechanism. The support mechanism has a first arm 7 that protrudes from approximately the center of the front end of the base 2 toward the front of the sower 1, and a second arm 8 that extends to the left from the tip of the first arm. The protruding length of the first arm 7 from the front end of the base 2 in the travel direction is set to a length such that one end of the first arm 7 (hereinafter referred to as the tip of the first arm 7) is located forward of the front wheels 3R ​​and 3L. The other end of the first arm 7 in the length direction is integrally connected to the base 2 by a connecting means. The connecting means may be a conventionally known connecting means, and may be, for example, an adhesive, welding, riveting, or bolting. One end in the longitudinal direction of the second arm portion 8 is connected to the tip portion of the first arm portion 7 so as to be rotatable about the axis of the first arm portion 7 as a central axis of rotation.

[0017] In the case where an operator is positioned behind the seeder 1 to control the travel direction of the seeder 1, it is preferable to place the position detection device 6 on the front side of the seeder 1, since this makes it easier to grasp the traveling position of the seeder 1. However, as long as the traveling position of the seeder 1 can be grasped, the mounting position of the position detection device 6 may be anywhere. For example, even if the position detection device 6 is mounted behind the operator, it is within the scope of the present invention as long as it is configured to be able to grasp the amount of deformation of the position detection device 6, which will be described later, using a mirror, camera, position sensor, etc.

[0018] Furthermore, when the seeder 1 is made to travel by switching back without turning the head, it is sufficient for the first arm portion 7 to be positioned on one side in the width direction of the base body 2. Therefore, it does not matter if it cannot rotate left and right.

[0019] In the example shown in FIG. 1, the second arm portion 8 extends to the left side (upper side in FIG. 1) with respect to the traveling direction of the seeder 1, that is, toward the rut side used as a guide. In the example shown here, the length of the second arm portion 8 in the left-right direction with respect to the traveling direction of the seeder 1 or in the width direction of the seeder 1 is set to a length such that the other end of the second arm portion 8 (hereinafter referred to as the tip of the second arm portion 8) is approximately at the same position as the left front wheel 3L or the left rear wheel 4L in the left-right direction. Note that the second arm portion 8 may have a length greater than or less than the set length described above as long as it can grasp the traveling position. The length of the second arm portion 8 may be set to a length that allows the position detection device 6 attached to the second arm portion 8 to engage with the guide when traveling using ruts, stripes, etc. as a guide, that is, a length that allows the position detection device 6 to reach the guide in the left-right direction.

[0020] In the example shown in FIG. 1, the rod-shaped position detector 6 is connected to the tip of the second arm 8 so that it can rotate around the axis of the second arm 8 as a rotation center axis and can be selectively fixed while extending in the traveling direction. For example, one end of the position detector 6 is connected to the tip of the second arm 8 via a joint that can rotate around the arm 8. In addition, the other end of the position detector 6 (hereinafter referred to as the tip) is arranged lower than one end of the position detector 6 in the vertical direction of the sower 1 so as to engage with ruts, lines, water channels, grooves, etc. that function as guides. In other words, the position detector 6 is attached to the second arm 8 so as to incline downward from the front to the rear in the traveling direction. The shape of the tip of the position detector 6 is configured to fit inside ruts, lines, water channels, grooves, etc.

[0021] Here, the rigidity of the position detection device 6 and the rigidity of each arm section 7, 8 will be described. In the first embodiment, the rigidity of the position detection device 6 is set to a rigidity that allows bending and deformation in the left-right direction according to the amount of left-right movement of the seeder 1 when the seeder 1 moves in the left-right direction with the tip of the position detection device 6 engaged with the guide. In contrast, the rigidity of each arm section 7, 8, which is a support mechanism, is set to be higher than the rigidity of the position detection device 6, since it supports the position detection device 6. Note that rigidity means the resistance to deformation.

[0022] Examples of materials that constitute the position detection device 6 include natural materials such as bamboo, reeds, and wood, synthetic resin materials, and metal wires. In addition, since the tip of the position detection device 6 moves along the guide while being engaged with the guide, the position detection device 6 may be made of a material that is excellent in wear resistance and sliding properties. Examples of materials that are excellent in wear resistance and sliding properties include polyolefins such as ultra-high molecular weight polyethylene, synthetic resin materials including fluorine-based resins such as polyoxymethylene, polyamide, and PTFE, polyphenylene sulfide, polyether ether ketone, polyester, polyurethane, phenolic resin, and composite materials thereof. The position detection device 6 may be made of any of the above-mentioned materials, but natural materials such as bamboo, reeds, and wood are preferable in terms of ease of availability. In addition, the metal wire may be any material that can be bent and deformed, such as piano wire.

[0023] Examples of materials that may be used to form the first arm unit 7 and the second arm unit 8 include metal materials, wood, and resin materials. Each of the first arm unit 7 and the second arm unit 8 may be made of a material that is less prone to bending deformation than the material that forms the position detection device 6.

[0024] (guide) Examples of the guide include groove-like ruts and waterways (open channels) formed in a flooded field, and lines formed in the field using conventionally known markers. It is preferable to form them by waiting until the soil surface hardens to a certain extent after plowing the flooded field. This can increase the strength of the grooves, ruts, waterways, etc. to a certain extent, making them easier to trace by the position detection device 6. In other words, it becomes easier to maintain the engagement with the guide. In addition, a drainage waterway can be formed in the field as designed. If a waterway or a groove is formed in the field before plowing and then plowing is performed, the waterway or the groove formed before plowing can function as a waterway or a groove even after plowing, the groove or the waterway may be formed before plowing. As another example of the guide, a ridge or a rail can be used. In addition, a flexible linear body such as a rope that is stretched in a straight line in the field in advance can be used. Although the use of one form of guide is effective, combinations of different forms of guides, such as a groove and rope combination, may be equally effective and are within the scope of the present invention.

[0025] These guides are preferably located near the seeder 1, but may be located at a distance of at least the wheel width of the seeder 1. For example, the second arm portion 8 may be long, and the guide may be not only the rut of the most recent run, but also the ruts or grooves of the run two, three or more runs prior, and this is within the scope of the present invention. Also, the position detection device 15 may have a movable mechanism, and the seeder may run multiple times while the position information can be confirmed even with the linear body fixed, and this is within the scope of the present invention.

[0026] The period required for the soil to be compacted and the soil surface to become somewhat hard after plowing in a flooded field can be determined by experiment or experience. The above-mentioned furrows, ruts, water channels, etc. formed on the soil surface of the field are preferably linear, but the shapes of the furrows, ruts, water channels, etc. are not limited. In seed cultivation, it is essentially important to make the sowing intervals uniform. Therefore, as long as the sowing intervals are uniform, for example, the furrows, ruts, water channels, etc. may have an appropriate shape such as a partially curved shape, a meandering shape, a zigzag shape, etc., instead of a linear shape. The strength of the furrows, ruts, water channels, etc. means their resistance to breakage.

[0027] (seed) The seeds used in the embodiment of the present invention are preferably rice. There are no limitations on the variety of rice, and any of japonica rice, indica rice, and javanica rice can be applied. Rice is often cultivated in paddy fields in hot and humid regions, so the effects of the present invention can be achieved. In place of rice, any seeds that are sown in a flooded state can be preferably applied.

[0028] As the above-mentioned seeds, seeds that are coated with a seed coating agent and have a higher specific gravity than seeds in a dry state that are not coated with the seed coating agent (hereinafter, referred to as coated seeds) are preferred. This is because the coated seeds can be submerged in water in a flooded field and the coated seeds can be prevented from being washed away. There are no limitations on the seed coating agent that increases the specific gravity of the seeds, but a seed coating agent that has a higher specific gravity than the seeds is preferred. For example, a seed coating agent that contains a metal material or a high specific gravity material such as iron (Fe), silicon (Si), magnesium (Mg), calcium (Ca), aluminum (Al), manganese (Mn), copper (Cu), zinc (Zn), phosphorus (P), or molybdenum (Mo) is preferred.

[0029] From the viewpoint of the effect of increasing the specific gravity of the seed and the effect of the seed coating agent on the soil, it is preferable that the seed coating agent mainly contains an iron material. In the embodiment of the present invention, coated seeds called iron-coated seeds can be preferably applied. Examples of the iron material include iron oxide, iron powder, and slag. In addition, the seed coating agent may be a seed coating agent that combines one or two or more of the above-mentioned metal materials or high specific gravity materials.

[0030] The specific gravity of dry seeds not coated with seed coating agents is 1.1 g / cm 3 The specific gravity of iron-coated seeds is about 0.1 g / cm3 lower than that of dry seeds not coated with a seed coating agent. 3 More specifically, the specific gravity of the iron-coated seeds is preferably 1.2 g / cm 3 It is preferable that the content is equal to or more than 1.3 g / cm. 3 This is to prevent the coated seeds from sinking into the mud when sowing in a flooded field, to locate them near the soil surface, and to prevent the coated seeds from being washed away from the field. This also allows the iron-coated seeds to germinate and grow where they are sown. There is no upper limit on the specific gravity of the iron-coated seeds, but it is recommended that they be no more than 4.0 g / cm3. 3 This is to suppress an increase in material costs that would accompany an increase in the amount of seed coating agent used, and to suppress burial of the coated seeds in mud due to an increase in the specific gravity of the seeds.

[0031] (Method of producing coated seeds) There is no limitation on the method of coating the seeds with the above-mentioned iron material. For example, as shown in the "Iron-Coated Flooded Direct Seeding Manual 2010 (compiled by Kinki Chugoku Shikoku Agricultural Research Center, National Agriculture and Food Research Organization)", any method may be used, including manual coating and using a conventionally known mixer.

[0032] When using a mixer to coat the seed coating agent, a mixing blade type mixer or a container rotation type mixer can be used as the mixer. In addition, a concrete mixer with the mixing blade removed can also be preferably used as the mixer. Examples of mixing blade type mixers include a Henschel mixer and a concrete mixer. Examples of container rotation type mixers include a V-type mixer, a double cone mixer, an inclined rotation type pan mixer, and a rotary hoe type mixer.

[0033] A specific method for coating seeds with a seed coating agent is to appropriately charge and mix the seeds, iron powder or iron oxide powder as an iron material, calcined gypsum or polyvinyl alcohol resin as a binder, silica gel as an additive, a seed treatment agent, and fertilizer components in a mixer. Another method is to coat the seeds while spraying water or a treatment liquid mainly made of water. A similar method can be applied when coating seeds with other materials having a higher specific gravity than the seeds. Examples of other materials include materials containing iron oxide, slag, calcium, etc. Also applicable are methods of solidifying with rust, or with binders such as resin and lime.

[0034] (action) The operation of the seeder 1 according to the first embodiment will be described. The flooded field is plowed to level the soil surface. After the soil is compacted and the soil surface becomes somewhat hard, the seeder 1 is made to travel along, for example, ridges or furrows such as open channels formed around the field. In other words, the seeder 1 is made to travel using the ridges or furrows as a guide. As a result, furrow-like ruts are formed in the field. In addition, as the seeder 1 travels, iron-coated seeds are sown by the seeder 5 along the direction of travel of the seeder 1.

[0035] After the seeder 1 has traveled a specified distance, the direction of the seeder 1 is reversed by a steering device (not shown) and the seeder 1 turns around. In order to prevent the seeder 1 from re-seeding the area where the seeder 1 had traveled before turning around, the position where the seeder 1 travels is shifted by the width of the seeder 1 from the travel path of the seeder 1 before turning around. At this time, the travel path before turning around and the planned travel path after turning around are overlapped by the width of the wheels. This is to engage the position detection device 6 with the ruts formed by the travel before turning around.

[0036] In this manner, the seeder 1 is allowed to travel adjacent to the travel path before turning back and along the travel path before turning back. Then, the tip of the position detector 6 is pressed against and engaged with the rut formed by the travel before turning back. The rigidity of the position detector 6 is lower than the rigidity of each of the arm portions 7 and 8 of the position detector 6. Therefore, when the tip of the position detector 6 is pressed against the rut, it is curved so as to be convex toward the front in the traveling direction, as shown in FIG. 2. Then, the seeder 1 is caused to travel in the state shown in FIG. 1 and FIG. 2.

[0037] When the seeder 1 travels along the wheel tracks, that is, when the seeder 1 travels along the guide, the position detection device 6 extends along the traveling direction of the guide and the seeder 1, and the position detection device 6 is hardly deformed in the left-right direction relative to the traveling direction. Alternatively, the amount of deformation of the position detection device 6 in the left-right direction is smaller than when the seeder 1 moves in the left-right direction, as described later.

[0038] For example, when the seeder 1 moves to the right with respect to the guide (wheel rut) in the travel direction, one end of the position detection device 6 moves to the right together with the seeder 1. The tip of the position detection device 6 is pressed against and engaged with the wheel rut as described above, and so maintains that state. Even if the tip of the position detection device 6 moves slightly to the right, the tip comes into contact with the edge or side wall rising from the bottom of the wheel rut, preventing or suppressing further movement to the right.

[0039] As a result, the position detector 6 is in a cantilever state, and a bending moment corresponding to the amount of movement of the sower 1 to the right is generated in the position detector 6. The bending moment causes the position detector 6 to bend and deform so that it becomes convex toward the opposite direction (left side) to the movement direction (right side) of the sower 1. FIG. 3 shows this state. The amount of deformation of the bending deformation of the position detector 6 changes according to the amount of movement of the sower 1 in the left-right direction. In other words, when the deviation of the running position of the sower 1 relative to the guide in the left-right direction increases, the above-mentioned bending moment increases and the amount of deformation of the position detector 6 increases. On the other hand, when the deviation decreases, the bending moment decreases and the amount of deformation of the position detector 6 decreases. The amount of deformation of the position detector 6 can be confirmed, for example, by visual inspection.

[0040] Then, after traveling a predetermined distance in the field, the direction of the seeder 1 is reversed again in the same manner as above. Since the first arm portion 7 of the position detection device 6 is rotatably connected to the second arm portion 8, the first arm portion 7 is rotated about the axis of the second arm portion 8 as the central axis of rotation to position the position detection device 6 on the opposite side in the width direction of the seeder 1. Then, the tip of the position detection device 6 is pressed against and engaged with the ruts formed by traveling before turning back, and the seeder 1 is run in this state to sow seeds.

[0041] Thus, according to the embodiment of the present invention, the current travel position of the seeding machine 1 relative to the guide in the left-right direction can be easily grasped based on the deformation amount of the position detection device 6. Therefore, it is possible to quickly correct the travel position, and the seeding machine can be made to travel along the guide. In addition, since the position detection device 6 is exposed above the water surface, it is easy to check, and even when it is difficult to check the ruts due to mud being stirred up by traveling through a flooded field, the seeding machine can be made to travel along the guide. As a result, it is possible to prevent or suppress re-seeding in a place where seeds have already been sown, and also to prevent or suppress the occurrence of a part of the field that is not sown, and seeds can be sown in a predetermined position.

[0042] Second embodiment FIG. 4 is a diagram showing an example of a sowing machine according to a second embodiment of the present invention. FIG. 5 is a side view of the sowing machine shown in FIG. 4. The sowing machine 9 shown in FIGS. 4 and 5 is a manual three-wheel type sowing machine, in which a front wheel 3 is provided on the front side of the base body 2 in the traveling direction of the sowing machine 9, and left and right rear wheels 4R, 4L are provided on the rear side of the base body 2 in the traveling direction. The base body 2 is supported by those wheels 3, 4R, 4L, and a seeder 5 is provided on the base body 2. Since the other configurations are the same as those shown in FIG. 1, the same reference numerals as those in FIG. 1 are used and the description thereof is omitted. The operation of the second embodiment will be described together with the operation of the third embodiment.

[0043] Third embodiment Fig. 6 is a diagram showing an example of a seeding machine according to a third embodiment of the present invention. Fig. 7 is a side view of the seeding machine shown in Fig. 6. The seeding machine 10 shown in Figs. 6 and 7 is a manual two-wheel type seeding machine, and wheels 11R and 11L are provided on both the left and right sides of the base body 2 in the traveling direction of the seeding machine 10. The base body 2 is supported by the wheels 11R and 11L, and a seeder 5 is provided on the base body 2. Since the other configurations are the same as those shown in Fig. 1, the same reference numerals as those in Fig. 1 are used and the description thereof is omitted.

[0044] (Functions of the second and third embodiments) Even in the second and third embodiments, the seeding machines 9 and 10 are first driven along furrows such as ridges or open channels in a flooded field after plowing to form tracks. After driving a predetermined distance, the direction of the seeding machines 9 and 10 is reversed by operating the steering device in the same manner as in the first embodiment, and the driving position is shifted by the width of the seeding machines 9 and 10. Then, the position detection device 6 is pressed against and engaged with the track formed by the driving before turning back, and the seeding machines 9 and 10 are driven in this state to drive in the field. In Figs. 4 and 6, the reversal of the seeding machines 9 and 10 is shown as a method of turning the seeding machines 9 and 10, but a method of switching back and moving backwards may also be used.

[0045] When the sower 9, 10 is traveling along the rut, that is, along the guide, the position detection device 6 extends along the traveling direction of the guide and the sower 9, 10, and the position detection device 6 does not bend or deform in the left-right direction relative to the traveling direction. Alternatively, the amount of deformation of the position detection device 6 in the left-right direction is smaller than when the sower 1 moves in the left-right direction. On the other hand, when the sower 9, 10 moves in the left-right direction relative to the guide, the position detection device 6 is bent or deformed according to the above-mentioned principle. Since the amount of deformation of the position detection device 6 changes depending on the amount of movement of the sower 9, 10 in the left-right direction, the current traveling position of the sower 9, 10 relative to the guide in the left-right direction can be easily grasped based on the amount of deformation of the position detection device 6. As a result, the traveling position of the sower 9, 10 can be corrected to make the sower 9, 10 travel along the guide. In this way, even in the second embodiment and the third embodiment, the same action and effect as the first embodiment can be obtained.

[0046] (Fourth embodiment) FIG. 8 is a diagram showing an example of a sowing machine according to the fourth embodiment of the present invention. FIG. 9 is a side view of the sowing machine shown in FIG. 8. In the example shown here, the rigidity of the position detection device 6 is increased more than that of the position detection device 6 of the first to third embodiments, and the position detection device 6 is configured to be swingable in the left and right direction with the movement of the sowing machine 12 in the left and right direction. Specifically, the position detection device 6 shown in FIG. 8 and FIG. 9 is made of the same metal material as the arm parts 7 and 8. Therefore, compared with the position detection device 6 of the first to third embodiments, the position detection device 6 of the fourth embodiment is less likely to bend and deform. In addition, one end of the position detection device 6 is connected to the tip of the second arm part 8 so as to be swingable in the left and right direction. The position detection device 6 may be connected to the second arm part 8 so as to be swingable in the left and right direction, and for example, the tip of the second arm part 8 and one end of the position detection device 6 are connected via a universal joint, a hook joint, a ball joint, or the like. 8 and 9 show a two-wheel type seeder 12, but a three-wheel type seeder or a four-wheel type seeder may be used instead. Since the other configurations are the same as those shown in Fig. 1, the same reference numerals as in Fig. 1 are used and the description thereof is omitted.

[0047] (Function of the Fourth Embodiment) In a flooded field after plowing, the seeder 12 is first driven along a furrow such as a ridge or an open channel to form a wheel track. After driving a predetermined distance, the direction of the seeder 1 is reversed by operating the steering device in the same manner as in the first to third embodiments, and the driving position is shifted by the width of the seeder 1. Then, the tip of the position detection device 6 is pressed against the wheel track formed by the driving before turning back, and the seeder 1 is driven in this state through the field. The rigidity of the position detection device 6 in the fourth embodiment is increased compared to the rigidity of the position detection device 6 in the first to third embodiments. Therefore, even if the tip of the position detection device 6 is pressed against the wheel track, the position detection device 6 is hardly deflected or deformed.

[0048] When the seeder 1 runs along the track, i.e., the guide, the position detection device 6 extends along the traveling direction of the seeder 12, and the position detection device 6 does not swing left or right relative to the traveling direction. Alternatively, the angular range of swinging of the position detection device 6 in the left or right direction is smaller than the angular range in the case where the seeder 1 moves left or right, as described below. Therefore, the angle θ formed by the position detection device 6 and the second arm portion 8 on a plane parallel to the field is maintained approximately constant. In the fourth embodiment, it is maintained at approximately 90 degrees. In this way, the angle θ formed by the position detection device 6 and the second arm portion 8 on the plane when the seeder 12 runs along the guide is referred to as the reference angle θ. 0 Let us assume that.

[0049] On the other hand, when the seeder 12 moves left and right relative to the guide, one end of the position detection device 6 moves left and right together with the seeder 12. Meanwhile, the tip of the position detection device 6 is pressed against the wheel rut and maintains an engaged state. One end of the position detection device 6 is connected to the tip of the second arm portion 8 so as to be swingable left and right. Therefore, the angle θ between the position detection device 6 and the second arm portion 8 due to the movement of the seeder 12 left and right changes from the above-mentioned reference angle θ 0 Specifically, as shown in FIG. 8, when the sower 12 moves away from the wheel track, the angle θ changes from the reference angle θ 0 On the other hand, when the sower 12 moves left and right so as to approach the wheel track, the angle θ becomes larger than the reference angle θ 0 will be smaller than

[0050] Such a reference angle θ 0 The amount of change in the angle θ from the guide changes according to the amount of movement of the seeder 12 in the left-right direction. Therefore, the current running position of the seeder 12 relative to the guide in the left-right direction can be easily grasped based on the angle θ between the position detection device 6 and the second arm portion 8. As a result, the seeder 12 can be made to run along the guide as in the first to third embodiments. In this way, even in the fourth embodiment, the same actions and effects as in the first to third embodiments can be obtained.

[0051] Fifth embodiment FIG. 10 is a diagram showing an example of a seeding machine according to the fifth embodiment of the present invention. FIG. 11 is a side view of the seeding machine shown in FIG. 10. The example shown in FIG. 10 and FIG. 11 is an example in which a flexible linear body 14 stretched in advance in a flooded field is used as a guide, and the seeding machine 13 is configured to travel along the linear body 14. Specifically, the seeding machine 13 shown in FIG. 10 and FIG. 11 is a manual two-wheel type seeding machine, and position detection devices 15 are provided at the center parts in the width direction at the front end and the rear end of the base body 2 of the seeding machine 1. The position detection device 15 shown here is configured in a plate shape as an example. A slit that is approximately the same as the outer diameter of the linear body 14 or slightly wider than the outer diameter of the linear body 14 is formed in the plate. The linear body 14 is configured to be engaged with the slit so as to be relatively movable. In FIG. 11, linear body 14 is shown lifted up by position detection device 15, but linear body 14 may be positioned slightly above position detection device 15 and stretched in a straight line so as not to touch position detection device 15.

[0052] The position detector 15 may be fixed to the base 2, or may be configured to be movable in the width direction (left and right direction) of the base 2. Figures 10 and 11 show a case where the position detector 15 is fixed to the base 2. When the position detector 15 is fixed to the base 2, the relative position of the sower 13 with respect to the guide can be grasped by the bending angle of the linear body 14. When the position detector 15 is configured to be movable in the width direction (left and right direction) of the base 2, the relative position of the sower 13 with respect to the guide can be grasped by reading the amount of displacement in the left and right direction with respect to a preset reference position or an initial position. The sower 13 is an example of the fifth embodiment, and the position detector 15 is attached to a drum seeder 5. Note that a handle for operating the drum seeder is omitted for simplification.

[0053] It is preferable that linear body 14 be made straight by applying tension, and there are no limitations on the material that constitutes linear body 14, so long as it is such a linear body 14. Examples of materials that constitute linear body 14 include rope, line, string, thread, fishing line, resin wire, wire rope, steel wire, and metal wire. Since linear body 14 only needs to be made straight by tension, it may be located on or underwater.

[0054] A plurality of linear bodies 14 may be placed in the field at a predetermined sowing interval. Alternatively, one linear body 14 is stretched in a straight line in the field, and the seeding machine 13 is made to run along the linear body 14 to sow seeds. Thereafter, one linear body 14 is stretched in a straight line in the field at a predetermined sowing interval, and the seeding machine 13 is made to run along the linear body 14 to sow seeds. This may be repeated. There is no limit to the number of linear bodies 14 stretched in the field.

[0055] (Operation of the fifth embodiment) In a flooded field after plowing, at least one linear body 14 is stretched in a straight line along the planned line along which the seeding machine 13 will travel. The linear body 14 is passed through a slit in the position detection device 15 of the seeding machine 13, and in this state, the seeding machine 13 is made to travel along the linear body 14 to sow seeds. After traveling a predetermined distance, the direction of the seeding machine 13 is reversed or switched back in the same manner as in the first to fourth embodiments, and the traveling position is shifted by the width of the seeding machine 13. Then, the linear body 14 is stretched in a straight line again in the field. The linear body 14 is passed through a slit in the position detection device 15 of the seeding machine 13, and in this state, the seeding machine 13 is made to travel along the linear body 14 to sow seeds. This is repeated. The planned line of travel mentioned above means the planned path along which the seeding machine 13 is to travel.

[0056] When the sower 13 travels along the linear body 14, both the linear body 14 on the front side and the linear body 14 on the rear side in the traveling direction of the sower 13 maintain a straight line. Therefore, the linear body 14 does not deform in the left-right direction. Alternatively, the bending angle of the linear body 14 becomes smaller compared to when the sower 1 moves in the left-right direction, as described later.

[0057] As shown in Figs. 10 and 11, a case where the position detection device 15 is fixed to the base 2 will be described. When the sowing machine 13 moves to one side in the left-right direction, the part of the linear body 14 that is passed through the slit of the position detection device 15 moves to one side in the left-right direction together with the sowing machine 13. Therefore, the linear body 14 bends with the slit of the position detection device 15 as an inflection point. The bending angle of the linear body 14 on a plane parallel to the field changes according to the amount of movement of the sowing machine 13 in the left-right direction, and gradually becomes smaller as the amount of movement of the sowing machine 13 in the left-right direction increases. In other words, the bending of the linear body 14 becomes larger. The bending angle of the linear body 14 is visually confirmed. In addition, when the linear body 14 is positioned slightly above the position detection device 15 and stretched in a straight line so as not to touch the position detection device 15, the linear body 14 is used as a marker and the deviation of the position detection device 15 from the linear body 14 in the left-right direction is visually confirmed.

[0058] A case will be described where the position detection device 15 is configured to be movable in the width direction (left-right direction) of the base 2. When the seeder 13 moves to one side in the left-right direction, the position detection device 15 moves relative to a reference position. The relative position of the seeder 13 with respect to the linear body 14, which is the planned traveling line, can be grasped based on the amount of displacement of the position detection device 15 relative to this reference position. Then, by changing the course of the seeder 13 so as to return the position detection device 15 to the reference position, the seeder 13 can be returned to the planned traveling line.

[0059] Therefore, based on the bending angle of the linear body 14, the deviation of the position detection device 15 from the linear body 14 in the left-right direction, and the displacement of the position detection device 15 from the reference position, the current running position of the seeder 13 with respect to the planned running line in the left-right direction can be easily grasped. As a result, the seeder 13 can be run in the same way as in the first to fourth embodiments. In this way, even in the fifth embodiment, the same actions and effects as in the first to fourth embodiments can be obtained.

[0060] To stretch the linear body 14 in a straight line in a vast farm field requires a considerable amount of tension, and the guide rope or the like is prone to bending. For this reason, the interval at which the linear body 14 is stretched, i.e., the length of the linear body 14 stretched in a straight line, may be appropriately adjusted, or relay sections may be provided to suppress bending of the linear body 14. This can reduce the tension required to stretch the linear body 14 in a straight line, and also suppress bending of the linear body 14.

[0061] Sixth embodiment FIG. 12 is a diagram showing an example of a sowing machine according to the sixth embodiment of the present invention. FIG. 13 is a side view of the sowing machine shown in FIG. 12. The sowing machine 16 shown in FIGS. 12 and 13 is a manual two-wheel type sowing machine, similar to the sowing machine 10 of the third embodiment. The handle 17 as a steering device of the sowing machine 16 is attached to the base body 2 or the seeder 5 so that the handle 17 is positioned on the front side in the front-rear direction of the sowing machine 16 or on the rear side in the front-rear direction. Specifically, the handle 17 shown in FIGS. 12 and 13 is in the shape of a rectangular ring, and among the four sides of the handle 17, the first side 17a extends in a direction substantially parallel to the width direction of the sowing machine 16. The first side 17a of the handle 17 is attached in a manner that allows it to rotate with respect to the rotation axis (not shown) of the base body 2, the seeder 5, or the wheel 11. For example, the handle 17 may be rotatably attached to the base body 2 via a hinge (not shown). Alternatively, a sleeve (not shown) configured to place the rotation shaft of the wheel 11 inside with a predetermined gap may be attached to the rotation shaft, and the handle 17 may be attached to the rotation shaft via the sleeve. Figures 12 and 13 show an example in which the handle 17 is attached to the rotation shaft of the wheel 11 via a sleeve. In the above-mentioned seeding machine 16, the operator uses the second side 17b of the handle 17, which is substantially parallel to the first side 17a, to push or pull the seeding machine 16. In the example shown in Figure 12, the seeding machine 16 is pulled using the handle 17. In addition, in order to simplify the drawing, the seeder 5 is omitted in Figure 12, but the seeder 5 is a cylindrical device with holes that also serves as the base 2, and is configured to store and sow seeds.

[0062] One end in the longitudinal direction of the second arm portion 8 is fixed to the end on the left side in the traveling direction of the seeder 16 of the second side 17b of the handle 17. The second arm portion 8 extends in a direction substantially parallel to the width direction of the seeder 16. The fixing means for the second arm portion 8 to the handle 17 may be a conventionally known fixing means, such as adhesive, welding, riveting, bolting, etc. The other configuration is similar to the configuration shown in Figure 8, so the same reference numerals as in Figure 8 are used and the description thereof will be omitted.

[0063] (Operation of the sixth embodiment) In a flooded field after plowing, the seeder 16 is first driven along a furrow such as a ridge or an open channel to form a wheel track. After driving a predetermined distance, the seeder 16 is stopped once, and the handle 17 is rotated backward in the traveling direction with the wheel axis as the rotation center, as shown in FIG. 13. The traveling position is shifted by the width of the seeder 16, and the position detection device 6 is pressed against and engaged with the wheel track formed by the traveling before (hereinafter, referred to as immediately before) the handle 17 is rotated. Then, the seeder 16 is driven in the opposite direction to the traveling direction of the seeder 16 immediately before the handle 17 is rotated. That is, in the example shown in FIG. 12, the seeder 16 is switched back.

[0064] When the sower 16 is traveling along the rut, that is, along the guide, the interval between the position detection device 6 and the guide is almost constant, and the position detection device 6 extends along the traveling direction of the guide and the sower 16. In other words, the position detection device 6 does not bend or deform in the left-right direction relative to the traveling direction. Alternatively, the amount of deformation of the position detection device 6 in the left-right direction is smaller than when the sower 1 moves in the left-right direction. On the other hand, when the sower 16 moves in the left-right direction relative to the guide, the position detection device 6 is bent or deformed according to the above-mentioned principle. The amount of deformation of the position detection device 6 changes depending on the amount of movement of the sower 16 in the left-right direction. Therefore, based on the amount of deformation of the position detection device 6, the current traveling position of the sower 16 relative to the guide in the left-right direction can be easily grasped. As a result, the traveling position of the sower 16 can be corrected to make the sower 16 travel along the guide. In this way, even in the sixth embodiment, the same actions and effects as those of each of the above-mentioned embodiments can be obtained.

[0065] Seventh embodiment When the seeding machines 1, 9, 10, 12, 13, 16 are caused to travel along the guide, there may be a slight deviation (hereinafter, sometimes referred to as an error or azimuth) between the direction along the guide and the direction along the actual travel direction. In addition, the above-mentioned guide is not always constant, but is different every time the seeding machines 1, 9, 10, 12, 13, 16 travel back and forth in the field. Therefore, when the seeding machines 1, 9, 10, 12, 13, 16 travel back and forth multiple times in the field, the above-mentioned errors gradually accumulate, and there is a possibility that the seeding cannot be regularly performed over the entire field. Here, regularly performing seeding over the entire field means that the multiple rows formed by the seeds sown in the field are approximately parallel to each other. It also means that the travel direction (hereinafter referred to as the reference direction) when the seeding machine first travels in the field and the travel direction when the seeding machine travels in the field thereafter are almost parallel to each other, that is, the azimuth angle, which is the angle between these travel directions, is equal to or less than a predetermined angle. As an example, the azimuth angle is preferably 6° or less, and more preferably 3° or less. For example, when the azimuth angle is 6° and the seeding machine travels 10 m from the specified position, the distance between the line along the reference direction and the seeding machine, that is, the deviation width, is about 1.0 m. When the azimuth angle is 3° and the seeding machine travels 10 m from the specified position, the deviation width is about 0.5 m. For these reasons, in order to make the deviation width as small as possible, it is preferable that the azimuth angle is as small as possible. Therefore, it is preferable that the azimuth angle is as small as possible in order to sow seeds regularly throughout the field. In addition, the deviation width means the distance between the intersection of a line along the reference direction with a line perpendicular to the line along the reference direction and passing through a point where the seeder has traveled 10 m from the specified position, and the above-mentioned point.

[0066] Specifically, Fig. 14 is a diagram for explaining the state where seeds are regularly sown over the entire field, and shows the direction of travel of the seeding machine when it travels back and forth across the field multiple times. In the example shown in Fig. 14, the directions of travel of the seeding machine when it travels back and forth across the field multiple times are almost parallel to each other. In other words, the azimuth angle formed by the direction of travel of the seeding machine on the first outward trip, i.e., the reference direction D1, and the direction of travel of the seeding machine on the fifth outward trip, D2, is almost 0°.

[0067] Fig. 15 is a diagram for explaining a state where seeds are not regularly sown over the entire field, and shows the direction of travel of the seeding machine when it travels back and forth over the field multiple times. In the example shown in Fig. 15, the directions of travel of the seeding machine when it travels back and forth over the field multiple times are not nearly parallel to each other. In other words, the azimuth angle formed by the direction of travel of the seeding machine on the first outward trip, i.e., the reference direction D1, and the direction of travel of the seeding machine on the fifth outward trip, D2, is not nearly 0°.

[0068] Therefore, the seeding machine according to the seventh embodiment of the present invention is configured to acquire a signal from a positioning satellite of a satellite positioning system, and calculate the position of the seeding machine (hereinafter, referred to as position information) and an azimuth angle based on the acquired signal. Then, the running position of the seeding machine, that is, the running direction, can be corrected based on the above-mentioned position information and azimuth angle. FIG. 16 is a diagram showing an example of a seeding machine according to the seventh embodiment of the present invention. FIG. 17 is a side view of the seeding machine shown in FIG. 16. The seeding machine 18 shown in FIG. 16 and FIG. 17 is a manual two-wheel type seeding machine configured almost similarly to the seeding machine 16 of the sixth embodiment, and a holder (not shown) is installed in the center of the handle 17 in the width direction. A mobile terminal 19 configured to be able to acquire a signal from the satellite positioning system is detachably attached to the holder. The above-mentioned mobile terminal 19 corresponds to the position information acquisition device in the present invention.

[0069] The satellite positioning system may be a global positioning system (GPS) or a global navigation satellite system (GNSS). The GNSS is preferable because it receives signals from positioning satellites used in other satellite positioning systems in addition to the positioning satellites used in GPS, and may be able to obtain position information with higher accuracy than GPS. The satellite positioning system may be a real time kinematic (RTK, hereinafter referred to as GNSS-RTK) or a differential global positioning system (DGPS, hereinafter referred to as GNSS-DGPS) among the GNSSs. These include a fixed station that can receive signals from the positioning satellites and whose position coordinates are accurately known and installed on the ground, and a mobile station that can receive signals from the positioning satellites and is configured to be movable. The position information based on the signals from the positioning satellites received by the fixed station is used to correct the position information based on the signals from the positioning satellites received by the mobile station, thereby improving the accuracy of the position information of the mobile station. When using GNSS-RTK or GNSS-DGPS as the satellite positioning system, the mobile terminal 19 attached to the handle 17 functions as a mobile station. Note that in Fig. 16 and Fig. 17, the position detection device 6 is omitted in order to simplify the drawings. Since the other configuration is similar to the configuration shown in Fig. 13, the same reference numerals as in Fig. 13 are used for the same configuration as in Fig. 13, and the description thereof will be omitted.

[0070] FIG. 18 is a diagram showing an example of the configuration of a mobile terminal 19. The mobile terminal 19 shown in FIG. 18 includes a receiver 21, a controller 22, a memory 23, a display 24, and an operation unit 25. The receiver 21 is configured to receive signals from a plurality of positioning satellites 20, and may be a conventionally known antenna, for example. In order to obtain highly accurate position information, it is preferable that the receiver 21 receives signals from a plurality of positioning satellites 20. Specifically, it is preferable that the receiver 21 receives signals from four or more positioning satellites 20. This is because the difference between the calculated current position and the actual position can be reduced by calculating the current position based on position information based on signals from three positioning satellites 20 and the time of reception from the fourth positioning satellite 20. The signal received by the receiver 21 is input to the controller 22.

[0071] The control unit 22 is mainly composed of a microcomputer, and is configured to perform calculations based on input data, pre-stored data, and calculation formulas, and output the results. The control unit 22 shown in Fig. 18 performs calculations based on signals received by the receiving unit 21, and calculates the position information, travel trajectory, reference direction, and azimuth angle of the sowing machine 18 in the field.

[0072] The storage unit 23 is, for example, a part that stores various information calculated by the control unit 22, and map information may be stored in advance in the storage unit 23. The map information may be configured to be acquired via wireless communication from a server connected to an Internet line. The display unit 24 is a part that displays various information and map information calculated by the control unit 22, and the above-mentioned various information and map information are displayed on the display unit 24 so that an operator can visually confirm them. It is preferable to display the position information, travel trajectory, reference direction, and azimuth angle of the sowing machine 18 superimposed on the map information. The display unit 24 may be a conventionally known monitor.

[0073] The operation unit 25 is configured to be operated by an operator, and to read out various information stored in the memory unit 23 and display it on the display unit 24, for example.

[0074] (Operation of the Seventh Embodiment) In a flooded field, the operator drives the seeder 18 along a guide that is currently used as a guide for driving. The mobile terminal 19 receives signals from multiple positioning satellites 20, and calculates the current position information, driving trajectory, reference direction, and azimuth angle of the seeder 18 in the field based on the received signals. The information is stored in a memory unit 23 of the mobile terminal 19 and is displayed on a display unit 24. In addition, each piece of information is updated every time signals are received from multiple positioning satellites 20. In other words, the information stored in the memory unit 23 is updated, and the updated information is displayed on the display unit 24.

[0075] Therefore, even when the sower 18 is caused to travel back and forth multiple times in a flooded field, the operator can always check with the latest information whether the sower 18 is traveling along the reference direction. Even if the deviation of the sower 18 in the left-right direction relative to the guide is small and not problematic, when such deviation accumulates and the azimuth angle becomes larger than a predetermined angle, the operator can steer the handle 17 to correct the traveling direction of the sower 18. As a result, the azimuth angle can be made as small as possible, and the multiple rows formed by the seeds sown in the field can be made almost parallel to each other even if the sower 18 travels back and forth multiple times. Thus, in the sower 18 of the seventh embodiment, compared to the sowers 1, 9, 10, 12, 13, and 16 of the above-mentioned embodiments, even if the sower 18 travels back and forth multiple times in the field, the sower 18 can regularly sow the seeds over the entire field as shown in the above-mentioned FIG. 14.

[0076] Furthermore, the seeder 18 of the seventh embodiment is equipped with a position detection device 6. Therefore, even if it is difficult to receive a signal from the positioning satellite 20 due to, for example, bad weather, radio interference, or a malfunction of the mobile terminal 19, the seeder 18 can be made to travel along a guide based on the deformation amount of the position detection device 6, so that seeds can be sown at a predetermined position. In other words, it is possible to obtain substantially the same functions and effects as those of the sixth embodiment.

[0077] The present invention is not limited to the first to seventh embodiments described above. For example, in the first to third, fifth, sixth, and seventh embodiments, the deviation of the travel position of the seeding machines 1, 9, 10, 13, 16, and 18 at the present time relative to the planned travel line is grasped by visual inspection. Instead of this, the deformation amount of the position detection device 6 and the linear body 14 may be detected by a strain sensor, a laser distance meter, or the like. When the change amount of the position detection device 6 or the linear body 14 detected by a strain sensor, a laser distance meter, or the like exceeds a preset threshold value, a warning may be issued to the operator of the seeding machines 1, 9, 10, 13, 16, and 18. By doing so, the travel position of the seeding machines 1, 9, 10, 13, 16, and 18 may be prompted to be corrected. Alternatively, the steering device may be controlled based on the change amount of the position detection device 6 described above, and the travel position of the seeding machines 1, 9, 10, 13, 16, and 18 may be automatically corrected.

[0078] In the above-mentioned fourth embodiment, the angle θ between the position detection device 6 and the second arm unit 8 may be detected by a laser distance meter, an angle sensor, or the like. When the angle θ detected by the laser distance meter, the angle sensor, or the like exceeds a preset threshold value, a warning may be issued to the operator of the seeder 12 to prompt the operator to correct the traveling position of the seeder 12. Alternatively, the steering device may be controlled based on the above-mentioned angle θ, and the traveling position of the seeder 12 may be automatically corrected.

[0079] In addition, the detection of the traveling position by the position detection device 6, 15 described above may be used in combination with the detection of the traveling position by a strain sensor, a laser distance meter, an angle sensor, or the like. For example, even when it is difficult to detect the laser of the laser distance meter on a fine day, the traveling positions of the seeding machines 1, 9, 10, 12, 13, 16, 18 can be detected and grasped by the position detection device 6, 15 according to this embodiment. In addition, even when the strength of the rut is low and it is difficult to trace the rut or to engage the position detection device 6 with the rut by the position detection device 6 of the first to fourth, sixth, and seventh embodiments, the traveling position can be detected by the laser distance meter. As a result, compared with the case where the position detection device 6 is used alone, the detection accuracy of the traveling position of the device as a whole can be improved, and it becomes easier to run the seeding machines 1, 9, 10, 12, 13, 16, 18 along the rut. Furthermore, the traveling position may be detected while checking the rut underwater using underwater box glasses or polarized glasses. When the strength of the ruts is low or the tension of the linear body 14 is low, making it difficult to detect the traveling position using the position detection devices 6, 15, and when the water in the field is highly transparent, the traveling position can be detected using underwater goggles or polarized glasses. Therefore, compared to when the position detection devices 6, 15 are used alone, the detection accuracy of the traveling position of the device as a whole can be improved, making it easier to run the seeders 1, 9, 10, 12, 13, 16, 18 along the ruts.

[0080] In addition, when the seeding machines 1, 9, 10, 12, 13, 16, and 18 are provided with a driving force source, the driving force source may be a small driving force that assists the operation of the seeding machines 1, 9, 10, 12, 13, 16, and 18 by the operator. Even when the driving force generated by the driving force source is small, the labor load can be reduced. In addition, since a driving force source with a small driving force can be used, the cost related to the driving force source can be reduced.

[0081] In the fifth embodiment, the linear body 14 functioning as a guide is engaged with the position detection device 15 provided in the seeder 13, so the seeder 13 can also be configured with a small boat, hovercraft, drone, or the like that does not directly contact the soil surface. Even in a seeder 13 configured in this way, by providing a position detection device 15 according to an embodiment of the present invention, the traveling position of the seeder 13 can be grasped based on the deformation amount of the linear body 14 or the displacement amount of the position detection device 15 relative to the base 2. Therefore, the same actions and effects as those of the first to sixth embodiments can be obtained. EXAMPLES

[0082] Next, examples 1 to 17 of the invention and comparative examples 1 to 6 carried out to confirm the effects of the seeding machines 1, 9, 10, 12, 13, and 16 and the seeding method according to the present invention will be described.

[0083] (Example 1) Inventive Example 1, a four-wheel type seeding machine is used, and a position detection device configured in substantially the same manner as the position detection device 6 of the first embodiment is attached to it. In addition, in order to make the position detection device flexible, the position detection device is configured in the shape of a rod made of ultra-high molecular weight polyethylene (described as a flexible rod in Table 1 described later). Rice seeds to be sown have a specific gravity of 1.5 g / cm 3 The seeding machine having the above-mentioned configuration was driven through a flooded field to spot sow the iron-coated seeds.

[0084] (Example 2) In Example 2, a two-wheel type seeding machine was used, and a position detection device configured in a manner similar to that of the position detection device 15 of the fifth embodiment was attached to the seeding machine. In addition, the seeding machine was run along a rope that had been installed in advance in the field, and spot seeding was performed. The rice seeds used were the same as those in Example 1.

[0085] (Example 3) In Example 3, a three-wheel type seeding machine was used, and a position detection device configured in a manner similar to that of the position detection device 6 of the first embodiment was attached to it. In addition, the position detection device was configured using piano wire, i.e., high-tensile steel wire. The seeding machine configured as described above was run through a flooded field with shallow water management and partial water fall, and iron-coated seeds were spot-sown. The rice seeds used were the same as those used in Example 1.

[0086] (Example 4) Inventive Example 4, a two-wheel type seeding machine is used, and a position detection device constructed in a manner similar to the position detection device 6 of the first embodiment is attached to it. In addition, this is an example in which the position detection device is constructed from split bamboo. The rice seeds are coated with iron oxide and have a specific gravity of 1.3 g / cm 3 The seed sowing machine having the above-mentioned configuration was driven through a flooded field to spot sow the iron oxide coated seeds.

[0087] (Example 5) In the fifth example of the invention, reeds are used as the position detection device 6, and rice seeds are covered with slag, and the specific gravity is 1.2 g / cm 3 In this example, slag-coated seeds were used. Other than that, the same procedure as in Example 4 was followed and the slag-coated seeds were spot-sown in a flooded field.

[0088] (Example 6) Inventive Example 6, a two-wheel type seeder is used, to which a position detection device configured in substantially the same manner as the position detection device 6 of the fourth embodiment is attached so as to be swingable left and right. The position detection device is, as an example, configured from the same metal material as the arm sections 7, 8. As rice seeds, iron-coated seeds similar to those in the first embodiment were used, and the seeder configured as described above was driven through a flooded field to seed the iron-coated seeds in rows.

[0089] (Example 7) Inventive Example 7, a two-wheel type seeding machine is used, and a position detection device constructed in a manner similar to the position detection device 6 of the first embodiment is attached to it. The position detection device is made of polyoxymethylene resin. 3 The iron-coated seeds were used and seeded by the above-described seeding machine.

[0090] (Example 8) In the eighth example of the invention, the position detection device is made of polyamide resin, and the specific gravity of the rice seed is 3.0 g / cm 3 This is an example in which iron-coated seeds were spot-sown. The rest of the experiment was the same as in Example 7.

[0091] (Example 9) In the ninth example of the invention, the position detection device is made of polyester resin, and the specific gravity of the rice seed is 4.0 g / cm 3 This is an example in which iron-coated seeds having the above properties were spot-sown using a seeder configured in the same manner as in Example 1 of the present invention. The rest of the experiment was the same as in Example 7 of the present invention.

[0092] (Example 10) In the example 10 of the invention, the position detection device was made of polyethylene resin, and iron-coated seeds were scattered in a field. The rest of the example was the same as the example 1 of the invention.

[0093] (Example 11) In Example 11, a fishing line was used as a guide instead of the rope used in Example 2, and iron-coated seeds were spot-sown in a field. The rest of the experiment was the same as Example 2.

[0094] (Example 12) Example 12 is an example in which a stainless steel wire was used as a guide instead of the fishing line of Example 11. Other than that, it was the same as Example 11.

[0095] (Example 13) Inventive Example 13, a position detection device configured in a manner similar to that of the position detection device 15 of the fifth embodiment is attached to a small boat. In addition, this is an example in which iron-coated seeds are scattered in a field using a wire rope previously installed in the field as a guide.

[0096] (Example 14) Inventive example 14, a two-wheel type seeding machine is used, and a handle configured in a similar manner to the handle 17 described in the sixth embodiment is attached to the drum seeder of the seeding machine. In addition, a position detection device configured in a similar manner to the position detection device 6 of the first embodiment is attached to the handle. In other words, this is an example of a seeding machine configured to switch back. The operator can check the status of the position detection device by pulling the handle backwards or by pushing the handle. This is an example of a simplified device configuration. In addition, the position detection device is made of ultra-high molecular weight polyethylene, and iron-coated seeds are seeded in rows in the field as the seeding machine travels.

[0097] (Example 15) Example 15 of the invention is an example in which a two-wheel type seeding machine is used, to which a position detection device configured in substantially the same manner as the position detection device 6 of the first embodiment, and a mobile terminal using GNSS-RTK as a satellite positioning system are attached. Also, correction information for correcting position information based on signals received by the mobile terminal is obtained from an Internet line connected by wireless communication. Furthermore, in order to make the position detection device flexible, this is an example in which the position detection device is configured in the shape of a rod made of synthetic resin material (referred to as a flexible rod in Table 1 described later). Rice seeds to be sown have a specific gravity of 1.5 g / cm 3 The seeding machine having the above-mentioned configuration was driven through a flooded field to sow the iron-coated seeds in rows.

[0098] (Example 16) Example 16 of the invention is an example in which a mobile terminal using GNSS-RTK as a satellite positioning system is attached to the seeder of Example 2 of the invention. In addition, correction information for correcting the position information based on the signal received by the mobile terminal is obtained from an Internet line connected by wireless communication. Other than that, it is the same as Example 2 of the invention.

[0099] (Example 17) Example 17 of the invention is an example in which a mobile terminal using GNSS-RTK as a satellite positioning system is attached to the seeder of Example 6 of the invention. In addition, correction information for correcting the position information based on the signal received by the mobile terminal is obtained from an Internet line connected by wireless communication. Other than that, it is the same as Example 6 of the invention.

[0100] Comparative Example 1 Comparative Example 1 is an example in which a conventionally known rotary marker was attached to a four-wheel type seeder, and the seeder was driven along the lines formed in the field by the rotary marker as a guide to perform spot sowing. In addition, uncoated rice seeds that were not coated with the above-mentioned seed coating agent were used as the rice seeds. Furthermore, the seeder configured as described above was driven through a field in a drained state to spot sow rice seeds.

[0101] Comparative Example 2 Comparative Example 2 is an example in which a two-wheel type seeder was used, a rod having approximately the same rigidity as each of the arms 7, 8 was attached to the tip of the second arm 8 of the seeder so as not to swing left and right, and the rod traced the tracks. Uncoated rice seeds were used, and the seeder configured as described above was run on a water-logged field to spot sow the rice seeds.

[0102] Comparative Example 3 Comparative Example 3 is an example in which rice seeds were spot-sown in a flooded field by running a seeder configured in the same manner as in Comparative Example 1. Other than that, the comparative example was the same as Comparative Example 1.

[0103] Comparative Example 4 In Comparative Example 4, the specific gravity of the rice seed is 1.5 g / cm 3This is an example in which iron-coated seeds were used. Other than that, the same as in Comparative Example 1.

[0104] Comparative Example 5 In Comparative Example 5, the specific gravity of the rice seed is 1.5 g / cm 3 In this example, iron-coated seeds having the same structure as in Comparative Example 2 were used, and rice seeds were spot-sown in a flooded field by running a seeder having the same structure as in Comparative Example 2. The rest of the experiment was the same as in Comparative Example 2.

[0105] Comparative Example 6 Comparative Example 6 is an example in which a two-wheel type seeding machine is used and a mobile terminal using GNSS-RTK as a satellite positioning system is attached to it. In other words, Comparative Example 6 is an example in which the above-mentioned position detection device is not mounted on the seeding machine. In addition, correction information for correcting the position information based on the signal received by the mobile terminal is obtained from an Internet line connected by wireless communication. The rice seeds to be sown have a specific gravity of 1.5 g / cm. 3 The seeding machine having the above-mentioned configuration was driven through a flooded field to sow the iron-coated seeds in rows.

[0106] Coating of the seeds with iron powder (dust dressing) was carried out according to the method described in the above-mentioned "Iron-Coated Direct Seeding Manual for Flooded Water 2010." Materials other than iron powder, specifically iron oxide and slag, were coated on the rice seed surface using a binder.

[0107] (Evaluation method and evaluation) (Position accuracy) When the seeder was driven about 10m along the track or linear body that acted as a guide, the positional accuracy was evaluated based on the maximum deviation in centimeters of the center line of the seeder from the center axis of the track or linear body to the left or right. In other words, the positional accuracy was evaluated based on the distance the center line of the seeder moved from the center axis of the track or linear body to the left or right. The judgment was as follows. The symbol "◎" in Table 1 indicates that the deviation was 3cm or less. The symbol "〇" indicates that the deviation was more than 3cm and less than 10cm. The symbol "△" indicates that the deviation was more than 10cm and less than 20cm. The symbol "×" indicates that the deviation was more than 20cm.

[0108] (Azimuth) The azimuth angle means the angle between the reference direction and the direction in which the seeder is currently traveling. Specifically, the seeder was made to travel 10m in a straight line from a specified position, then turned around and traveled another 10m in a straight line. This round trip was performed five times. The direction in which the seeder traveled on the first outward trip was set as the reference direction, and the angle between this and the direction in which the seeder traveled on the fifth outward trip was set as the azimuth angle. The azimuth angle was judged as follows. The symbol "◎" indicates that the azimuth angle was 1° or less. The symbol "〇" indicates that the azimuth angle was greater than 1° and less than 3°. The symbol "△" indicates that the azimuth angle was greater than 3° and less than 6°. The symbol "×" indicates that the azimuth angle was greater than 6°.

[0109] (Row resistance) Washout resistance refers to the difficulty of seeds sown in a flooded field to move. It was evaluated based on the distance the seeds moved from the sowing position a specified time after sowing in the field with a seeder. In the case of sowing in a water-repellent field, it was the distance the seeds moved after the field was returned to flooded after sowing. The evaluation was made as follows. The symbol "◎" in Table 1 indicates that the above-mentioned movement distance was 3 cm or less. The symbol "◯" indicates that the movement distance was more than 3 cm and less than 10 cm. The symbol "△" indicates that the movement distance was more than 10 cm and less than 20 cm. The symbol "×" indicates that the movement distance was more than 20 cm.

[0110] (Water usage) The amount of drainage for sowing was evaluated. One drainage is roughly equivalent to draining water from a paddy field with a flood depth of 5cm. The judgment was made as follows. The symbol "◎" in Table 1 indicates that the amount of drainage was 0.2 or less. The symbol "〇" indicates that the amount of drainage was more than 0.2 and less than 0.5. The symbol "△" indicates that the amount of drainage was more than 0.5 and less than 1.0. The symbol "×" indicates that the amount of drainage was more than 1.0.

[0111] (Amount of weeds) 1m after sowing, 2 weeks later 2 The number of weeds per area was evaluated. The judgment was as follows. The symbol "◎" in Table 1 indicates 50 or less weeds. The symbol "〇" indicates more than 50 and less than 100 weeds. The symbol "△" indicates more than 100 and less than 200 weeds. The symbol "×" indicates more than 200 weeds.

[0112] The evaluation results of the above-mentioned invention examples 1 to 17 and comparative examples 1 to 6 are shown together in Table 1. Note that the seeder position shown in Table 1 means the position where the seeder is located. [Table 1]

[0113] According to the seeding machine and seeding method of the present invention, as shown in Table 1, in the invention examples 1 to 17, the seeding machine can be easily positioned in a flooded field, that is, the seeds can be regularly sown at regular intervals throughout the field, as compared with the comparative examples 1 to 6. In addition, since iron-coated seeds, iron oxide-coated seeds, slag-coated seeds, etc., which have a higher specific gravity than uncoated seeds, are used, they are less likely to be washed away compared with uncoated seeds. Furthermore, since the seeds can be sown in a flooded field, there is no need to drain the water once when sowing, and as a result, the amount of water used can be reduced compared with the conventionally known flooded direct seeding method. Moreover, since the field is kept flooded, the growth and overgrowth of weeds can be suppressed compared with a drained field, and bird damage can be suppressed. [Explanation of symbols]

[0114] 1, 9, 10, 12, 13, 16, 18 Seeding machine 2 Base 3, 3R, 3L front wheel 4R, 4L rear wheel 5. Cedar 6, 15 Position detection device 7 First arm section, support mechanism 8 Second arm section, support mechanism 11 wheels 14 Linear body 17 Handle 17a, 17b One side of the handle 19 Mobile Devices 20 Positioning satellites 21 Receiving section 22 Control section 23 Memory section 24 Display section 25 Control section

Claims

1. A seeder that sows seeds in a flooded field is provided on a base supported by wheels configured to be able to travel in the field, a position detection device that uses at least one of a wheel rut formed in the field by the wheels, a waterway formed in advance in the field, and a linear groove formed in advance in the field as a guide and engages with the guide; a support mechanism provided on the base for supporting the position detection device with a predetermined gap between the position detection device and the base in a left-right direction relative to a traveling direction, The position detection device is configured in a rod shape, One end of the rod-shaped position detection device is engaged with the guide, A seeder, wherein the other end of the rod-shaped position detection device is connected to the support mechanism so that the rod-shaped position detection device deforms in the left-right direction or oscillates in the left-right direction when the base moves in the left-right direction relative to the guide.

2. A seeder comprising a base supported by wheels configured to be capable of traveling through a flooded field, and a seeder for sowing seeds in the field, a flexible linear body stretched in a straight line in advance in the field serves as a guide, and a position detection device is provided on the base and engages with the guide, The position detection device is a plate, A seeder, wherein the plate has a slit configured to engage with the linear body so that the linear body can move relative to the plate.

3. The seeder according to claim 1 or 2, further comprising a position information acquisition device that acquires position information based on a signal acquired from a satellite positioning system.

4. A sowing method comprising sowing seeds using the sowing machine according to claim 1 or 2.

5. A method for sowing seeds using the seeder according to claim 3.

6. The seeds are coated with a seed coating agent containing a metal material and have a specific gravity of 1.2 g / cm ３ 4.0g / cm or more ３ 5. The method of claim 4, wherein:

7. The seeds are coated with a seed coating agent containing a metal material and have a specific gravity of 1.2 g / cm ３ 4.0g / cm or more ３ 6. The method of claim 5, wherein:

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