Work vehicle

Abstract

To make workability during a swing motion better than that in prior arts while securing a yield of crops on a farm field.SOLUTION: A work vehicle comprises a swing member (61) which is supported by a vehicle body (10) and which supports the vehicle body (10) in a grounded state in such a manner as to be swingable with respect to a farm field surface, and a movement member (63) which moves the swing member (61) in the direction of grounding it on a farm field or separating it from the farm field. Thus, workability during a swing motion can be better than that in prior arts while securing a yield of crops on the farm field.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] Among work vehicles used for tasks such as transplanting seedlings into fields and tilling, a seedling transplanter is known that moves on wheels while transplanting seedlings into furrows, working by moving back and forth across multiple furrows (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3965000 Summary of the Invention [Problem to be solved by the invention]

[0004] As with the technology described in Patent Document 1, work in farm fields typically involves a work vehicle turning along a linear ridge or travel path to make reciprocating movements. To increase crop yields in farm fields, ridges are formed right up to the edge of the field, widening the area in which crops can be planted. Therefore, if a sufficient area is left unridged to facilitate turning, this can result in a reduction in crop yield, and so the area where ridges are not formed is narrowed to allow turning at the edge of the field. Therefore, the work vehicle described in Patent Document 1 has problems such as breaking up the edges of the ridges when turning, having to turn back and forth multiple times in narrow spaces to turn without coming into contact with the edges of the ridges, and having to lift the front or rear wheels while turning, which increases the burden on the worker when turning.In other words, the work vehicle described in Patent Document 1 has a problem of poor workability when turning.

[0005] The present invention has as its technical object to improve workability during turning compared to conventional techniques while ensuring crop yield in a field. [Means for solving the problem]

[0006] The above-mentioned problems of the present invention are solved by the following means. The invention described in claim 1 is a work vehicle (1) characterized by comprising a vehicle body (10), a work implement (20, 30) supported by the vehicle body (10) and operated when working in a field, a swivel member (61) supported by the vehicle body (10) and supporting the vehicle body (10) so that it can swivel relative to the field while in a grounded state, and a moving member (63) that moves the swivel member (61) in a direction to touch down on the field or move away from the field.

[0007] The invention described in claim 2 is a work vehicle (1) described in claim 1, characterized in that it comprises a ridge detection sensor (71) that detects ridges (102) in a field, a rotation angle sensor (72) that detects the rotation angle of the vehicle body (10) relative to the rotating member (61), and a control unit (300) that causes the moving member (63) to ground the rotating member (61) when a predetermined time has elapsed since the ridge detection sensor (71) stopped detecting the ridge (102), and that causes the moving member (63) to move the rotating member (61) away from the ground when the rotation angle detected by the rotation angle sensor (72) after the ridge detection sensor (71) stopped detecting the ridge (102) reaches a predetermined angle. [Effects of the Invention]

[0008] According to the invention described in claim 1, by providing a swivel member (61) that is supported by the vehicle body (10) and supports the vehicle body (10) so that it can swivel relative to the field while in a grounded state, and a moving member (63) that moves the swivel member (61) in a direction to touch the field or move away from the field, it is possible to ensure crop yield in the field while improving workability during turning compared to conventional technology.

[0009] According to the invention of claim 2, in addition to the effects of the invention of claim 1, when a predetermined time has elapsed since the ridge detection sensor (71) stopped detecting the ridge (102), the moving member (63) brings the swivel member (61) into contact with the ground, and when the rotation angle detected by the rotation angle sensor (72) after the swivel member (61) has touched the ground reaches a predetermined angle, the moving member (63) moves the swivel member (61) away from the ground, thereby automatically touching and separating the swivel member (61) from the ground, thereby improving workability. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a left side view showing a seedling transplanter according to an embodiment. [Figure 2] FIG. 2 is a top view showing the seedling transplanter of FIG. 1. [Figure 3] FIG. 2 is a rear view of the seedling transplanter of FIG. 1 with some parts omitted. [Figure 4] 4A and 4B are explanatory diagrams of the elevation of the swivel member in the embodiment, with FIG. 4A being an explanatory diagram of a state where it has been moved to the separated position, and FIG. 4B being an explanatory diagram of a state where it has been moved to the grounded position. [Figure 5] FIG. 5 is a functional block diagram of the control unit according to the embodiment. [Figure 6] Figure 6 is an explanatory diagram of the operation of the embodiment, where Figure 6(A) is an explanatory diagram of the seedling transplanter when traveling forward, Figure 6(B) is an explanatory diagram of the seedling transplanter when turning, and Figure 6(C) is an explanatory diagram of the seedling transplanter when traveling backward. [Figure 7] Figure 7 is an explanatory diagram of conventional turning operations, where Figure 7(A) is an explanatory diagram of the case where sufficient turning area is secured at the end of the ridge, and Figure 7(B) is an explanatory diagram of the case where the turning area is narrow. [Figure 8] Figure 8 is an explanatory diagram of an embodiment of the seedling transplanter when moving from a completed ridge to the next ridge, Figure 8(A) is an explanatory diagram of moving to the next ridge after rotating 180 degrees, and Figure 8(B) is an explanatory diagram of moving to the next ridge after rotating 90 degrees. [Figure 9] FIG. 9 is an explanatory diagram of another type of seedling transplanter, where FIG. 9(A) is a schematic diagram and FIG. 9(B) is an explanatory diagram of the seedling transplanter during rotation. [Figure 10] FIG. 10 is an enlarged view of the seedling planting device according to the embodiment. [Figure 11] FIG. 11 is an explanatory diagram of another embodiment of the seedling transplanter. [Figure 12] FIG. 12 is an explanatory diagram of the main part of a seedling planting tool for climbing seedlings, in which FIG. 12(A) is an explanatory diagram of another embodiment 2, and FIG. 12(B) is an explanatory diagram of the prior art. [Figure 13] 13A and 13B are explanatory diagrams of modified examples of FIG. 12, with FIG. 13A being an explanatory diagram of modified example 1 and FIG. 13B being an explanatory diagram of modified example 2. In FIG. [Figure 14] Figure 14 is an explanatory diagram of the operating part of the pressure wheel in the seedling transplanter shown in Figure 11, Figure 14(A) is an explanatory diagram of the cam shape, and Figure 14(B) is a graph of the profile of the arm rotation angle when the cam of Figure 14(A) is used. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1 to 3, a seedling transplanter 1, which is an example of a work vehicle of the present invention, is a transplanter that transfers and plants vegetable seedlings or the like in a field 100. The seedling transplanter 1 is equipped with a drive unit, such as an engine 11 and a transmission 12, mounted at the front of a vehicle body (an example of a vehicle body) 10, and a pair of front and rear wheels 13 and 14, which are part of a traveling unit that allows the seedling transplanter 1 to travel in the field 100, are provided at the front and rear of the vehicle body 10. The front wheels 13 are driven to rotate, while the rotational power of the engine 11 is transmitted to the rear wheels 14 via the transmission 12 and a transmission case 15 to drive the seedling transplanter 1. Reference numeral 10a in FIG. 1 denotes an upper cover, also called a bonnet, that covers the engine 11, transmission 12, and the like.

[0012] The seedling transplanter 1 is also provided with a control handle 90 that protrudes rearward from the vehicle body 10 and extends to the left and right. The seedling transplanter 1 is used by an operator who walks behind the machine and grips the control handle 90 to steer the machine. Between the left and right control handles 90 is an operation unit 91, which is configured by arranging various parts such as control levers, switches, and displays.

[0013] Furthermore, the seedling transplanter 1 is provided with a seedling supply device 20, a seedling planting device 30, etc. at the rear of the vehicle body 10. As a result, the seedling transplanter 1 is able to plant seedlings in the ridges 102 of the field 100 while moving across the ridges 102 using the left and right front wheels 13 and the left and right rear wheels 14.

[0014] The transmission case 15 has an input shaft 16, which is a drive output shaft that projects from the transmission 12 and extends in the left-right direction of the vehicle body 10, and houses therein transmission means 17 such as gears, sprockets, and a drive chain for transmitting the rotational power input from the input shaft 16 to the axle 14a of the rear wheel 14. The input shaft 16 is housed in a cylindrical support cover and is firmly attached to the vehicle body 10. The transmission case 15 also rotates vertically around the input shaft 16 as a fulcrum, thereby supporting the rear wheel 14 so that it can move up and down relative to the vehicle body 10. This transmission case 15 also serves as a support member for supporting the rear wheel 14, and is therefore constructed as a robust case made of a material such as metal.

[0015] The seedling transplanter 1 is also provided with a lifting cylinder 18 between the transmission 12 of the vehicle body 10 and the seedling planting device 30, which raises and lowers the machine body by moving the rear wheels 14 up and down via the transmission case 15. In this seedling transplanter 1, by operating the lifting cylinder 18 by extending and retracting, the transmission case 15 rotates so as to move up and down around the input shaft 16, and as a result, the left and right rear wheels 14 rise and fall in the same direction and by the same amount relative to the vehicle body 10. This allows the vehicle height of the seedling transplanter 1 to be adjusted. The seedling transplanter 1 is also equipped with a sensor plate 19 that comes into contact with the ridges 102 to detect the height of the ridges 102. In this seedling transplanter 1, the operation of the lifting cylinder 18 is controlled according to the detection results of the sensor plate 19 to automatically keep the vehicle body 10 in an almost horizontal position relative to the surface of the ridges 102, thereby maintaining a constant planting depth for the seedlings.

[0016] In addition, the seedling transplanter 1 for two-row planting in this embodiment is equipped with a so-called rolling mechanism, which operates the lifting cylinder 18 when there is a difference in height between the left and right sides of the ridge 102 (or its furrow), adjusting the amount of rotation around the input shaft 16 of at least one of the left and right transmission cases 15 as a fulcrum, thereby keeping the vehicle body 10 in an approximately horizontal position relative to the surface of the ridge 102.

[0017] The seedling supply device 20 supplies seedlings to be transplanted to the seedling planting device 30. As shown in Figures 1 to 3, this seedling supply device 20 is provided with a support frame 29 that rises upward from the rear of the vehicle body 10, and an endless chain 21 for transporting seedling storage cups that is arranged to protrude and extend in the left and right directions of the vehicle body 10 and can rotate around the support frame 29. This endless chain 21 is made up of a row of connected cylindrical cup holders 22, each fitted with a plurality of seedling storage cups 23, and is arranged so that some of them move around, passing above the seedling planting device 30. The seedling storage cups 23 are a plurality of cups with an open bottom structure for temporarily storing seedlings. In addition, the seedling supply device 20 is provided with a container holding mechanism 26, for example near the front of the endless chain 21, for holding a seedling container 25 containing seedlings to be put into the seedling storage cup 23.

[0018] In this seedling supply device 20, an operator or a dedicated worker sequentially places seedlings in the seedling container 25 into empty seedling storage cups 23 that are moved around by the endless chain 21. Meanwhile, in the seedling supply device 20, when the seedling storage cups 23 transported by the endless chain 21 pass a position above the seedling planting device 30, the bottom of the cup holding portion 22 of the seedling storage cups 23 that pass by is opened. As a result, the seedling supply device 20 is configured to drop the seedlings contained in the plurality of seedling containing cups 23 into the seedling planting device 30 and supply them.

[0019] 1 and 3, the seedling planting device 30 is equipped with a seedling receiving mechanism 31 and a seedling planting tool 35 that are supported so as to move up and down relative to a support frame 39 that is provided behind the vehicle body 10 and in the space below the seedling supply device 20. This seedling planting device 30 is configured, for example, as a two-row planting device.

[0020] The seedling receiving mechanism 31 is provided with a pair of left and right hoppers 32A, 32B that receive seedlings supplied from the seedling supply device 20. The pair of left and right hoppers 32A, 32B are arranged so that their upper openings face the two seedling storage cups 23 in the seedling supply device 20.

[0021] In this seedling receiving mechanism 31, a pair of left and right hoppers 32A, 32B are raised to approach the seedling supply device 20 according to the seedling planting season. The raised hoppers 32A, 32B each receive one seedling that is dropped from each of the two seedling storage cups 23. At this time, the seedlings received in the hoppers 32A, 32B drop into the seedling planting tool 35 located below the seedling receiving mechanism 31 and are transferred thereto.

[0022] The seedling planting tools 35 are arranged as a pair of left and right seedling planting tools 35A, 35B below the seedling receiving mechanism 31. Each of these seedling planting tools 35A, 35B is made up of a set of members that are split vertically into two parts, each shaped like an inverted cone tapering downwards, and are attached to a support frame 39 so that the lower ends of the set of members can open and close left and right, moving away from and toward each other.

[0023] This pair of left and right seedling planting tools 35A, 35B are first raised together with the seedling receiving mechanism 31 to approach the seedling supply device 20 in accordance with the planting season, and the seedlings received by the hoppers 32A, 32B of the seedling receiving mechanism 31 are then handed over. Next, the seedling planting tools 35A, 35B move downward toward the ridge 102, inserting their lower ends into the ridge 102 to a predetermined depth, and then the lower ends are separated and opened, allowing the seedlings to drop and land in the soil of the ridge 102. Thereafter, the seedling planting tools 35A, 35B bring their lower ends close together and move upward again to return to their original positions, and then operate in the same manner. As a result, the seedling planting tools 35A and 35B are configured to plant two rows of seedlings into the furrows 102 at a time.

[0024] 1 and 3, the seedling planting device 30 is also provided with a compacting device 40 that compacts the soil in the ridges 102 around the seedlings planted by the seedling planting tool 35. The crushing device 40 is composed of a pair of crushing wheels 41A, 41B arranged side by side on either side of a pair of seedling planting tools 35A, 35B. The crushing wheels 41A, 41B are attached to a support frame 42 below the crushing wheels 41A, 41B so that they rotate in an inclined position so that they approach each other. The seedling planting device 30 compacts the soil around the seedlings, thereby keeping the planted seedlings in a stable state.

[0025] 4A and 4B are explanatory diagrams of the elevation of the swivel member in the embodiment, with FIG. 4A being an explanatory diagram of a state where it has been moved to the separated position, and FIG. 4B being an explanatory diagram of a state where it has been moved to the grounded position. 1 and 4, the seedling transplanter 1 of the embodiment has a swivel plate 61, which is an example of a swivel member, disposed at the bottom of the vehicle body 10. The swivel plate 61 is disposed between the front wheels 13 and the rear wheels 14 in the fore-and-aft direction of the vehicle body 10. Specifically, the swivel plate 61 is disposed below the center of gravity of the seedling transplanter 1. The swivel plate 61 has a vertically extending swivel shaft 61a rotatably supported by a bearing 62, which is an example of a bearing. Therefore, when the swivel plate 61 is in a grounded state as shown in FIG. 4(B), the front wheels 13 and rear wheels 14 are separated from the field surface (they are suspended in mid-air). Therefore, an operator can manually rotate the seedling transplanter 1 around the swivel shaft 61a by operating the control handle 90. While the embodiment illustrates a manual rotation, this is not limiting. For example, a gear or a motor can be mounted on the bearing 62, and the motor can be used to automatically rotate the seedling transplanter 1 around the swivel shaft 61a.

[0026] The bearing 62 is supported by a lifting cylinder 63, which is an example of a moving member. The lifting cylinder 63 can move the bearing 62 and the swivel plate 61 in a direction to approach (contact) or move away from the surface (ground) of the field 100. Therefore, by operating the lifting cylinder 63, the swivel plate 61 can move between a position in contact with the field 100 as shown in Fig. 4(B) and a position away from the field 100 as shown in Fig. 4(A). In the embodiment of the seedling transplanter 1, the front wheels 13 and rear wheels 14 are moved away from the field when the rotating plate 61 touches the ground, but at this time, it is also possible to move the front wheels 13 and rear wheels 14 upward using a motor, cylinder, etc., so that they are reliably moved away from the field.

[0027] A ridge detection sensor 71 that detects ridges 102 is disposed at the front end of the vehicle body 10. The ridge detection sensor 71 emits electromagnetic waves (laser light, for example) downward and can detect the presence or absence of ridges 102 based on the waves reflected from the ridges 102. Therefore, it is possible to detect that the end of a ridge 102 has been passed by detecting that the ridge 102 has changed from present (detected) to absent (not detected) or from absent to present. Further, a rotation angle sensor 72 is disposed on the bearing 62 to detect the amount of rotation (rotation angle, rotation angle) of the rotation shaft 61a. Furthermore, a positioning unit 73, which is an example of a positioning device that detects the current position of the seedling transplanter 1, is disposed on the upper cover 10a.

[0028] (Explanation of the control unit of the seedling transplanter) FIG. 5 is a functional block diagram of the control unit according to the embodiment. The seedling transplanter of this embodiment has a control unit 300 that controls each function. The control unit 300 has an input / output interface I / O that performs input and output of signals from and to the outside. The control unit 300 also has a read-only memory (ROM) that stores programs and information for performing necessary processing. The control unit 300 also has a random access memory (RAM) for temporarily storing necessary data. The control unit 300 also has a central processing unit (CPU) that performs processing according to the programs stored in the ROM or the like. Therefore, the control unit 300 of this embodiment is configured as a small information processing device, a so-called microcomputer. Therefore, the control unit 300 can realize various functions by executing programs stored in the ROM or the like.

[0029] The control unit 300 receives signals from signal input elements such as the operation unit 91, the ridge detection sensor 71, the turning angle sensor 72, the positioning unit 73, and various other sensors (not shown).

[0030] The ridge detection sensor 71 detects the ridges 102 . The turning angle sensor 72 detects the turning angle around the turning axis 61a. The positioning unit 73 has a GNSS (Global Navigation Satellite System) receiver 73a and an IMU (Inertial Measurement Unit, an example of an inclination measurement component) 73b. The GNSS receiver 73a receives positioning signals from artificial satellites and can measure the current position of the seedling transplanter 1. The IMU 73b measures acceleration and angular velocity and can measure the direction (direction of travel) and attitude (left-right tilt and front-back tilt) of the seedling transplanter 1. Therefore, by correcting the measurement results of the GNSS receiver 73a with the measurement results of the IMU 73b, the current position can be measured more accurately than when the current position is measured using only the GNSS method.

[0031] The control unit 300 sends control signals to the power supply circuit E, which is an example of a controlled element, the engine 11, the transmission 12, the seedling supply device 20, the seedling planting device 30, the lifting cylinder 63, etc., to control the running / stopping and running speed of the seedling transplanter 1, the operation / stopping of the seedling supply device 20, the operation / stopping of the seedling planting device 30, the lifting and lowering of the swivel plate 61, etc. Furthermore, the control unit 300 can output a control signal to a display monitor (one example of a display unit, not shown) of the operation unit 91 to display work information, work status, and the like.

[0032] The control unit 300 has the following functional means (functional modules, program modules) 301 to 305. The positioning means 301 measures the current position of the seedling transplanter 1 based on the measurement results of the positioning unit 73. The ridge discrimination means 302 detects the presence or absence of the ridges 102 and the ends of the ridges 102 based on the detection results of the ridge detection sensor 71 .

[0033] The travel control means 303 controls the engine 11 and the transmission 12 to control the travel (acceleration / deceleration, steering, braking) of the seedling transplanter 1. During manual travel (when working in manual travel mode), the travel control means 303 controls the engine 11 and the transmission 12 in accordance with input to the operation unit 91 to control the travel (acceleration / deceleration, stopping) of the seedling transplanter 1. During automatic travel (when working in automatic travel mode), the travel control means 303 controls the engine 11, the transmission 12, etc. to automatically travel (acceleration / deceleration, braking) the seedling transplanter 1 in a straight line at a predetermined travel speed.

[0034] The work machine control means 304 controls the seedling supply device 20 and the seedling planting device 30 to control seedling supply and planting work. When work starts during manual or automatic travel, the work machine control means 304 in this embodiment controls the seedling supply device 20 and the seedling planting device 30 according to the travel speed to supply / stop seedlings or plant / stop seedlings. It is preferable to provide the seedling transplanter 1 with a sensor for detecting obstacles, and during automatic travel, the travel control means 303 stops automatic travel when it detects an obstacle or a bank (the edge of the field 100), and resumes automatic travel when it no longer detects an obstacle, thereby enhancing safety. Here, when automatic travel is stopped, it is preferable for the work machine control means 304 to control the seedling supply device 20, etc. to stop until automatic travel resumes, thereby reducing unnecessary power consumption. It is preferable to use an alarm means such as a buzzer, lamp, or voice guide to alert those around while an obstacle is detected.

[0035] The turning control means 305 controls the turning of the seedling transplanter 1 at the end of the ridge 102. In this embodiment, the turning control means 305 includes a turning time determination means 305a, a ground contact control means 305b, and a turning completion determination means 305c. In this embodiment, the turning control means 305 controls the turning when an input to select the automatic turning mode is made to the operation unit 91. Note that the turning control is not limited to when the automatic turning mode is selected; for example, a turning button may be provided on the operation unit 91, and turning control may be performed when an input is made from the turning button.

[0036] The turning time determination means 305a determines whether it is time for the seedling transplanter 1 to turn. In the embodiment, the turning time determination means 305a determines that it is time to turn when a predetermined time (turning determination time t1) has elapsed since the ridge determination means 302 passed the outer edge of the ridge 102. In the embodiment, the turning determination time t1 is set as an example of the time it takes for the seedling transplanter 1 to advance so far as to reach the distance between the ridge detection sensor 71 and the rear end of the rear wheels 14. In other words, it is determined that it is time to turn when the rear end of the rear wheels 14 reaches a position outside the edge of the ridge 102. Note that in the embodiment, the turning time is determined based on the turning determination time t1, but this is not limiting. For example, it is possible to determine that it is time to turn when the current position measured by the positioning means 301 is a predetermined distance from the edge of the ridge 102, or to determine the turning time by calculating the forward distance from the rotation speed of the front wheels 13 or the rear wheels 14. The turning determination time t1 and forward distance are not limited to the examples given above, and can be set to allow some leeway for the edge of the ridge 102, or the rear end of the turning plate 61 can reach the edge of the ridge 102 if the height lifted by the turning plate 61 is sufficient (if the lower end of the rear wheel 14 is lifted higher than the top surface of the ridge 102).

[0037] In the embodiment of the seedling transplanter 1, when the turning time determination means 305a determines that it is time to turn, the turning control means 305 sends a control signal to the travel control means 303 to stop the seedling transplanter 1 from traveling, and also sends a control signal to the work machine control means 304 to stop the work machine (seedling supply device 20 and seedling planting device 30).

[0038] When the turning time determination means 305a determines that it is time to turn, the ground contact control means 305b controls the lifting cylinder 63 to lower the turning plate 61 and make it touch the ground. When the turning plate 61 touches the ground, the seedling transplanter 1 is supported on the field surface by the turning plate 61, and the front wheels 13 and rear wheels 14 are suspended in the air above the field surface. From the viewpoint of preventing accidents and ensuring safety, it is preferable to notify the operator that the lifting cylinder 63 is about to operate by, for example, using voice guidance, a display, a buzzer, or the lighting of a lamp before or during control of the lifting cylinder 63.

[0039] The rotation completion determination means 305c determines that the rotation of the seedling transplanter 1 is complete when the rotation angle measured by the rotation angle sensor 72 reaches a predetermined angle while the rotating plate 61 is in contact with the ground. That is, when the operator manually rotates the seedling transplanter 1 around the rotation axis 61a while the rotating plate 61 is in contact with the ground, the rotation is determined to be complete when the amount of rotation (rotation angle) around the rotation axis 61a reaches a predetermined angle. For example, the rotation is determined to be complete when the rotation angle reaches 180 degrees. The rotation angle is not limited to the illustrated values. For example, the rotation angle may be determined to be complete when the rotation angle is within the range of 170 degrees to 190 degrees. The rotation angle is not limited to 180 degrees. For example, the rotation angle may be 90 degrees. Alternatively, the operator may select between 90 degrees and 180 degrees. Alternatively, the operator may input and set any desired rotation angle via the operation unit 91.

[0040] In the seedling transplanter 1 of this embodiment, when the turning completion determination means 305c determines that turning is complete, the lifting cylinder 63 is controlled to raise the turning plate 61 and move the turning plate 61 away from the field. Therefore, the front wheels 13 and rear wheels 14 of the seedling transplanter 1 contact the ground and become ready to travel. As mentioned above, from the viewpoint of preventing accidents, it is preferable to notify the operator that the lifting cylinder 63 is about to operate before or during control of the lifting cylinder 63. Then, when the lifting of the swivel plate 61 is completed, the swivel control means 305 sends a control signal to the travel control means 303 to resume travel of the seedling transplanter 1, and sends a control signal to the work machine control means 304 to resume operation of the work machines (seedling supply device 20 and seedling planting device 30). The timing for resuming operation of the work machines is when the seedling planting device 30 reaches the ridge 102 after travel has resumed and the edge of the ridge 102 has been detected. The timing for resuming operation of the work machines can also be set manually by the operator.

[0041] (Operation of the embodiment) Figure 6 is an explanatory diagram of the operation of the embodiment, where Figure 6(A) is an explanatory diagram of the seedling transplanter when traveling forward, Figure 6(B) is an explanatory diagram of the seedling transplanter when turning, and Figure 6(C) is an explanatory diagram of the seedling transplanter when traveling backward. In the seedling transplanter 1 of the embodiment having the above configuration, in automatic travel mode, the seedlings are transplanted into the ridge 102 while automatically traveling in a straight line along the ridge 102. In FIG. 6, when the ridge 102 is wide and can accommodate four rows of seedlings, and seedlings are transplanted using a two-row seedling transplanter 1, the seedlings 103 are planted in two rows on one side of the ridge 102 on the outbound path shown in FIG. 6(A). When the seedling transplanter 1 reaches the end of the ridge 102, the turning plate 61 touches the ground, and the seedling transplanter 1 turns as shown in FIG. 6(B). Then, on the return path shown in FIG. 6(C), the seedlings 103 are planted in the remaining two rows on the other side of the ridge 102.

[0042] Figure 7 is an explanatory diagram of conventional turning operations, where Figure 7(A) is an explanatory diagram of the case where sufficient turning area is secured at the end of the ridge, and Figure 7(B) is an explanatory diagram of the case where the turning area is narrow. In the prior art, when a sufficient turning area 02 is secured at the end of the ridge 01, as shown in Figure 7(A), the seedling transplanter can be turned by moving forward and steering. However, securing a sufficient turning area 02 narrows the area of ​​the ridge 01 in the field, which poses a problem of reduced crop yield. On the other hand, when the turning area 02' at the end of the ridge 01 is narrow, the seedling transplanter must turn back and forth several times, as shown in the turning path 03 in Figure 7(B), or the operator must turn while lifting the front or rear wheels by pushing down or lifting the operating handle of the seedling transplanter 1. This results in poor workability when turning.

[0043] In contrast, in the present embodiment, the seedling transplanter 1 is provided with a swivel plate 61. When the swivel plate 61 is lowered and touches the ground, the front and rear wheels 13 and 14 are suspended in midair. In this state, the seedling transplanter 1 is rotatable around the swivel shaft 61a. Therefore, the operator can turn the seedling transplanter 1 by operating the steering handle 90. Therefore, compared to the conventional embodiment shown in FIG. 7(A), turning is possible even in a narrow turning area, and workability during turning is improved. Therefore, even in a narrow turning area, the seedling transplanter 1 can turn, and the ridges 102 can be extended to the very edge of the field. Therefore, the seedling transplanter 1 of the present embodiment can ensure crop yield in the field 100 while improving workability during turning compared to conventional techniques.

[0044] In particular, in the seedling transplanter 1 of the embodiment, when the automatic turning mode is selected, the turning plate 61 descends and touches the ground when it passes the end of the ridge 102 and it is time to turn. Then, when turning is completed, the turning plate 61 rises and the front wheels 13 and rear wheels 14 touch the ground. Therefore, the turning plate 61 can be raised and lowered automatically without the operator having to operate it during turning, which improves the workability of turning compared to when the turning plate 61 does not rise and fall automatically. In addition, in this embodiment, the rotation shaft 61a is supported by the bearing 62, and there is no need to exert force to lift the seedling transplanter 1 when rotating. This reduces the burden on the operator and improves the workability of rotation.

[0045] Figure 8 is an explanatory diagram of an embodiment of the seedling transplanter when moving from a completed ridge to the next ridge, Figure 8(A) is an explanatory diagram of moving to the next ridge after rotating 180 degrees, and Figure 8(B) is an explanatory diagram of moving to the next ridge after rotating 90 degrees. 8, in the seedling transplanter 1 of the embodiment, when moving to the adjacent ridge 102, for example, as shown in FIG. 8(A), the rotating plate 61 can be rotated 180 degrees with the ground in place, and then automatically travel along the ridge transition path 401 based on the positioning results of the positioning means 301, thereby moving to the adjacent ridge 102-2. Alternatively, as shown in FIG. 8(B), the rotating plate 61 can be rotated 90 degrees with the ground in place, and then travel along the ridge transition path 401', thereby moving to the adjacent ridge 102-2.

[0046] FIG. 9 is an explanatory diagram of another type of seedling transplanter, where FIG. 9(A) is a schematic diagram and FIG. 9(B) is an explanatory diagram of the seedling transplanter during rotation. In the seedling transplanter 1' shown in Figure 9, as shown in Figure 9(A), the left and right front wheels 13R, 13L are each supported by a slider 501 on the vehicle body 10 so as to be movable in the front-rear direction, and are also supported by the slider 501 so as to be able to move up and down around an elevation shaft 502. The left and right rear wheels 14 are also configured so as to be able to be driven and stopped individually by a clutch (not shown). In FIG. 9(B), when transitioning to the adjacent ridge 102-2, the front wheel 13L on the inner periphery of the turn is raised above the height of the top surface of the ridge 102, and the rear wheel 14L on the inner periphery of the turn is stopped. Then, the front wheel 13R on the outer periphery of the turn is moved back and forth so that the distance between the front wheel 13R on the outer periphery and the rear wheel 14L on the inner periphery matches the distance L1 between the ridges 102. Then, by driving the rear wheel 14R on the outer periphery of the turn, it is possible to turn along an arc-shaped trajectory 503 with the distance L1 as its radius and the rear wheel 14L on the inner periphery as its center. Therefore, by applying the configuration shown in FIG. 9, it is possible to transition to the adjacent ridge 102-2 without using the turning plate 61.

[0047] The distance L1 between the ridges 102 can be registered in advance in the operation unit 91, or a camera or the like can be installed on the vehicle body 10 and the distance L1 can be calculated by image analysis. 9, the vehicle body 10 is supported by three wheels 13R, 14L, and 14R when turning, which makes it more unstable than when supported by four wheels 13L, 13R, 14L, and 14R. Therefore, it is preferable to mount a weight on the vehicle body 10 and make the position of the weight changeable with a cylinder, motor, or the like, so that the position of the weight can be changed when turning to move the center of gravity of the vehicle body 10 to a position where driving is more stable.

[0048] FIG. 10 is an enlarged view of the seedling planting device according to the embodiment. 10 shows only one row of the seedling planting device 30 according to the embodiment. In the seedling planting device 30 of this embodiment, springs 602, which are an example of multiple buffer members, are arranged between a base 601 at the bottom of the hopper 32, which moves upward to approach the seedling supplying device 20, and the upper surface of the support frame 39. The springs 602 are arranged at the four corners of the base 601. A limit switch 603 is also arranged below the base 601. Therefore, when planting seedlings by inserting the seedling planting tool 35 into the ridge 102 from above, if the height of the ridge 102 is locally high, a load is placed on the seedling planting tool 35, which may cause damage. In contrast, in this embodiment, the spring 602 expands and contracts, which can cushion the load or weight applied to the seedling planting tool 35, preventing damage to the seedling planting tool 35.

[0049] In particular, since the springs 602 are provided at the four corners, even if the load received from the ridges 102 is biased to either the front, back, left or right, the four springs 602 can distribute and receive the load evenly. It is preferable to set the elastic modulus of the spring 602 high so that it does not expand or contract under normal loads during normal operation, but expands and contracts when a load higher than a predetermined value is applied. This prevents the spring 602 from expanding or contracting during normal operation, thereby preventing excessive fluctuations in the vertical position of the seedling planting tool 35, i.e., the planting depth.

[0050] In the seedling transplanter 1 according to the embodiment, the current location is measured by the positioning unit 73 during operation, enabling the location where the seedlings were planted to be determined. Therefore, this work history information can be saved (stored) in the control unit 300 and used for analyzing the crop growth status or as a reference for work in the following years. While the work history information can be saved in the control unit 300 of the seedling transplanter 1, it is also possible to install a communication module capable of communicating with a server, an example of an external information processing device (computer), and manage (register, update, etc.) the work history information on the server. While wireless communication with the server is preferred, wired communication is also possible, in which a cable is connected after operation is completed. For wireless communication, any method, such as a mobile phone line, wireless LAN (Local Area Network), or Bluetooth (registered trademark), can be used.

[0051] Therefore, the seedling transplanter 1 can also acquire setting information such as the work area in the field, work route, running speed, planting interval (distance between plants), etc. as work information from the server, and after the work is completed, transmit historical information about the actual work. In addition, the server can communicate with multiple seedling transplanters 1, and can perform work by using the work history information of other seedling transplanters 1 of the same model that are registered on the server.

[0052] Furthermore, a drone, which is an example of an unmanned aerial vehicle, can be flown based on information on the location where the seedlings have been planted by the seedling transplanter 1. The drone can be equipped with a camera, objective sensor, color sensor, positioning unit, etc., to acquire images, size, color, etc. of the planted seedlings, and can be registered in association with work history information. The drone can also be flown periodically to acquire information on the growth status of the crops over time. It is also possible to mount a fertility sensor on a drone, hover the drone over an area where crop growth is poor, insert the two electrodes of the fertility sensor into the ridges 102, and measure the fertility level from the electrical resistance between the two electrodes. The fertility measurement results are sent to a server, and if the fertility level does not reach a predetermined value, it is desirable to issue a notification urging the worker to add fertilizer.

[0053] Note that, although a flying form such as a drone is preferable as a configuration for acquiring images of crops and fertility information, the present invention is not limited to this. It is also possible to use a wheeled work vehicle with a cart equipped with a camera, fertility sensor, etc. mounted thereon. It is also possible to mount a camera, etc. on a work vehicle or drone capable of fertilizing, watering, spraying pesticides, etc. In this case, it is also desirable to calculate the required amount of fertilizer, irrigation, and pesticide spray according to the growth status of the crops and perform fertilization, etc. from the work vehicle or drone.

[0054] Furthermore, while the seedling transplanter 1 in the embodiment is illustrated as being propelled by an engine 11, which is an example of an internal combustion engine, this is not limiting. It is also possible to use a motor, which is an example of an electric motor, as a configuration (a so-called electric vehicle) or a configuration that uses both the engine 11 and a motor (a so-called hybrid vehicle). In the seedling transplanter 1, the seedling supply device 20 and the seedling planting device 30 are located at the rear of the vehicle body 10, which tends to shift the center of gravity of the entire vehicle toward the rear. Using a motor requires a larger battery capacity. Therefore, it is preferable to install a large-capacity battery, a spare battery, or an additional battery at the front of the vehicle body 10 (in front of the upper cover 10a) to prevent the center of gravity from shifting toward the rear. In this case, it is preferable to make the battery detachable from the front of the vehicle body 10 for easy battery replacement.

[0055] FIG. 11 is an explanatory diagram of another embodiment of the seedling transplanter. In the embodiment shown in FIG. 1, a seedling transplanter 1 for root vegetables has been described, but the present invention is not limited to this. As shown in FIG. 11, the swivel plate 61 can also be applied to a seedling transplanter 1" for creeping seedlings such as sweet potato. Note that seedling transplanters for creeping seedlings are described in, for example, JP 2020-54259 A and are publicly known, so detailed description thereof will be omitted.

[0056] FIG. 12 is an explanatory diagram of the main part of a seedling planting tool for climbing seedlings, in which FIG. 12(A) is an explanatory diagram of another embodiment 2, and FIG. 12(B) is an explanatory diagram of the prior art. In Figure 12(A), seedling planting tool 35" for climbing seedlings has a pair of left and right claws 701 that can be opened and closed in the left-right direction. Each claw 701 has an inwardly protruding protrusion 702 on its inner surface. Each claw 701 has two protrusions 702 arranged vertically. The distance between the lower protrusions 702a is different from the distance between the upper protrusions 702b. In the form shown in Figure 12(A), the distance between the upper protrusions 702b is set wider than the distance between the lower protrusions 702a. It is preferable that protrusions 702 be made of an elastic material such as rubber so that they come into contact with seedlings 711 and are less slippery.

[0057] When planting a climbing seedling 711, the seedling planting tool 35" shown in Figure 12(A) opens the gap between the pair of claws 701 once for the seedling 711 held in the seedling transport section 721, allowing the seedling 711 to enter between the claws 701, and then closes the claws 701 to grasp the seedling 711.Then, as the seedling planting tool 35" moves toward the furrow 102, the seedling 711 is removed from the seedling transport section 721.

[0058] Here, seedlings 711 vary from one another, being either thick or thin. As shown in FIG. 12(B), in a conventional seedling planting tool 051, the spacing between the convex portions 052 is constant, so the gripping force on the seedlings is constant. When the seedlings are removed from the seedling transport unit, if the gripping force is too strong, the seedlings are torn off, and if the gripping force is too weak, the seedlings slip off, resulting in missing stalks in the furrows. In contrast, in the embodiment shown in FIG. 12(A), if the seedlings 711 are thin, they are firmly held by the lower convex portion 702a. If the seedlings 711 are thick, even if they are about to be gripped by the lower convex portion 702a, they will slide upward and be held by the upper convex portion 702b. Therefore, the seedlings 711 can be easily gripped with an appropriate gripping force depending on their condition, and missing stalks are easily prevented.

[0059] 13A and 13B are explanatory diagrams of modified examples of FIG. 12, with FIG. 13A being an explanatory diagram of modified example 1 and FIG. 13B being an explanatory diagram of modified example 2. In FIG. The shape of the seedling planting tool 35" is not limited to the shape shown in Figure 12. For example, as shown in Figure 13(A), a similar effect can be expected by configuring one of a pair of left and right claw portions 701 (701-1) without a convex portion 702 and the other claw portion 701 (701-2) to have a convex portion 702. Furthermore, as shown in Figure 13(B), a similar effect can be expected by configuring one claw portion 701 (701-1) to have two convex portions 702 and the other claw portion 701 (701-2) to have a semicircular convex portion 706 that faces both of the two convex portions.

[0060] Figure 14 is an explanatory diagram of the operating part of the pressure wheel in the seedling transplanter shown in Figure 11, Figure 14(A) is an explanatory diagram of the cam shape, and Figure 14(B) is a graph of the profile of the arm rotation angle when the cam of Figure 14(A) is used. In Figure 14, pressure wheel 41, which covers seedlings 711 planted in ridge 102 and holds down the soil, moves up and down in conjunction with the raising and lowering (planting) of seedling planting tool 35". Pressure wheel 41 is connected to swing arm 732. Swing arm 732 is supported so as to be rotatable around rotation shaft 732a. Cam follower 733 is supported at one end of swing arm 732. Cam follower 733 is in contact with cam 734. In addition, spring 736 is connected to swing arm 732. Spring 736 applies an elastic force in a direction that presses cam follower 733 against cam 734.

[0061] The cam 734 is supported rotatably around a rotation shaft 737 in a rotation direction 738. The up and down movement of the seedling planting tool 35" is converted into rotation by a crank or the like (not shown) and transmitted to the rotation shaft 732a. The outer peripheral surface of the cam 734 has, in order along the rotation direction 738, a first enlarged diameter portion 734a, a first reduced diameter portion 734b, a first small diameter portion 734c, a second enlarged diameter portion 734d, a first large diameter portion 734e, a second reduced diameter portion 734f, and a second small diameter portion 734g. In the embodiment shown in FIG. 14, when the seedling planting tool 35" is located in the stop position (highest position), the cam follower 733 is set to contact the first small diameter portion 734c. In other words, the seedling planting tool 35" is set to grip the seedlings 711 in front of and behind the first small diameter portion 734c. When the cam follower 733 is in contact with the first large diameter portion 734e, the suppression wheel 41 is in the most raised state, and when the cam follower 733 is in contact with the second small diameter portion 734g, the suppression wheel 41 is set to press down on the upper surface of the ridge 102.

[0062] In the conventional configuration, the first diameter reducing portion 734b, the first small diameter portion 734c, and the second diameter increasing portion 734d were not provided, and the first diameter increasing portion 734a was followed by the first large diameter portion 734e. In this configuration, when the seedling planting tool 35'' grips the seedlings 711, the seedling planting tool 35'' moves quickly, which can damage the seedlings 711. In contrast, in the configuration shown in Figure 14, the first diameter reducing portion 734b and the first small diameter portion 734c are provided, which have diameters smaller than the first diameter increasing portion 734a and the first large diameter portion 734e, so the gripping speed is slowed down and damage to the seedlings 711 is reduced.

[0063] Furthermore, by providing the first diameter reduction portion 734b, the first small diameter portion 734c, and the second diameter expansion portion 734d, the cam follower 733 receives a force from the spring 736 that naturally moves it toward the first small diameter portion 734c. In a conventional configuration that does not include the first diameter reduction portion 734b, the first small diameter portion 734c, and the second diameter expansion portion 734d, the cam follower 733 tends to move toward the first diameter expansion portion 734a. When the seedling planting tool 35'' moves toward the first diameter expansion portion 734a, the seedling planting tool 35'' descends, causing the claws 701 to open apart. Therefore, even if the seedling planting tool 35'' is stopped in the stopped position, if the seedling planting tool 35'' descends due to the force of the spring 736, there is a risk that the seedlings 711 that were once gripped by the seedling planting tool 35'' may fall off. In contrast, in the form shown in Figure 14, the force of the spring 736 makes it easier for the seedling planting tool 35" to be held in the first small diameter portion 734c, making it easier for the seedling planting tool 35" to be held in the stopped position.As a result, the seedling planting tool 35" is easier to be held in a closed state, and the seedlings 711 that have been grasped by the seedling planting tool 35" are less likely to fall off. [Explanation of symbols]

[0064] 1...Work vehicle, 10... Vehicle body, 20,30...Work equipment, 61...swivel member, 63...moving member, 71...ridge detection sensor, 72...turning angle sensor, 102...ridge, 300...Control unit.

Claims

1. A vehicle body (10), a work implement (20, 30) supported on the vehicle body (10) and operable during work in a field; a swivel member (61) supported on the vehicle body (10) and supporting the vehicle body (10) swivelably relative to the field surface while in a grounded state; a moving member (63) that moves the rotating member (61) in a direction to bring the rotating member (61) into contact with or away from the field; A work vehicle (1) comprising:

2. a ridge detection sensor (71) for detecting a ridge (102) in a field; a turning angle sensor (72) for detecting a turning angle of the vehicle body (10) relative to the turning member (61); a control unit (300) that causes the moving member (63) to bring the rotating member (61) into contact with the ground when a predetermined time has elapsed since the ridge detection sensor (71) stopped detecting the ridge (102), and that causes the moving member (63) to move the rotating member (61) away from the ground when the rotation angle detected by the rotation angle sensor (72) after the ridge detection sensor (71) has grounded reaches a predetermined angle; A work vehicle (1) according to claim 1, characterized in that it comprises:

Images