Seedling transplanter

Abstract

To provide a seedling transplanter allowing a reliable and easy operation for starting planting of seedlings from a ridge edge.SOLUTION: A seedling transplanter includes a traveling vehicle body, a seedling planting part, and a lifting / lowering control part. The traveling vehicle body can travel in a farm field. The seedling planting part is liftably / lowerably provided at the rear of the traveling vehicle body. The seedling planting part in a lowered state, plants seedlings on a soil surface of the farm field, while the traveling vehicle body is moving forward. The lifting / lowering control part controls lifting / lowering of the seedling planting part. When the seedling planting part is moved to a ridge edge side in the farm field and then the traveling vehicle body is moved backward toward the ridge edge in order to start the planting of the seedlings, the lifting / lowering control part executes special lifting / lowering control for positioning the seedling planting part at a height close to the soil surface without grounding the seedling planting part to the soil surface.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This invention relates to a seedling transplanter. [Background technology]

[0002] Conventionally, in seedling transplanters that have a retractable seedling planting unit at the rear of the machine and plant seedlings on the soil surface of a field while the machine is moving forward with the seedling planting unit lowered, in order to start planting seedlings from the edge of the field ridge, for example, when the machine is moving forward and approaches the ridge, the machine is turned with the seedling planting unit raised, and then the machine is reversed with the seedling planting unit raised to bring the seedling planting unit closer to the edge of the ridge (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-139374 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, conventional seedling transplanters, as described above, sometimes require skilled operators to lower the seedling planting unit to the appropriate position at the edge of the ridge, and there was room for improvement in the operation of starting seedling planting from a position as close to the ridge as possible (at the edge of the ridge). Furthermore, if the seedling planting unit is not lowered to the appropriate position at the edge of the ridge, if it is far from the ridge, for example, fewer seedlings may be planted in the field, potentially reducing the yield of the crop (rice). If it is too close to the ridge, for example, the descending seedling planting unit may collide with the ridge, potentially causing the ridge to collapse or the seedling planting unit to be damaged.

[0005] The present invention has been made in view of the above, and aims to provide a seedling transplanter that can reliably and easily perform the operation of starting the planting of seedlings from the edge of the ridge. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the object, the seedling transplanter (1) according to the embodiment includes a traveling vehicle body (2) capable of traveling in a field (F), and a lifting mechanism provided behind the traveling vehicle body (2) and capable of being lifted and lowered. When the traveling vehicle body (2) is in a lowered state and moving forward, a seedling planting unit (3) for planting seedlings on the soil surface (FS) of the field (F), and a lifting control unit (100) for controlling the lifting and lowering of the seedling planting unit (3). The lifting control unit (100) performs special lifting and lowering control to position the seedling planting unit (3) at a height close to the soil surface (FS) without contacting the soil surface (FS) when the traveling vehicle body (2) is reversely traveled toward the ridge edge (FS R ) in the field (F) in order to start planting seedlings after moving the seedling planting unit (3) closer to the ridge edge (FS R ) in the field (F). [Effect of the Invention]

[0007] According to the seedling transplanter according to the embodiment, the operation of starting to plant seedlings from the ridge edge can be performed reliably and easily. [Brief Description of the Drawings]

[0008] [Figure 1] FIG. 1 is a schematic side view showing a seedling transplanter according to the embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of a control system of the seedling transplanter according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram of a seedling planting operation by the seedling transplanter according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram (Part 1) of special lifting and lowering control by the lifting control unit. [Figure 5] FIG. 5 is an explanatory diagram (Part 2) of special lifting and lowering control by the lifting control unit. [Figure 6] FIG. 6 is an explanatory diagram (Part 3) of special lifting and lowering control by the lifting control unit. [Figure 7] FIG. 7 is a diagram showing a transmission configuration to a fertilizer drive shaft. [Figure 8] FIG. 8 is an explanatory diagram (Part 1) of the configuration of an electric rotor. [Figure 9] Figure 9 is an explanatory diagram (part 2) of the configuration of the electric rotor. [Figure 10] Figure 10 is an explanatory diagram (part 3) of the configuration of the electric rotor. [Figure 11] Figure 11 is an explanatory diagram (part 1) of the configuration related to the electrification of the seedling transplanter. [Figure 12] Figure 12 is an explanatory diagram (part 2) of the configuration related to the electrification of the seedling transplanter. [Figure 13] Figure 13 is an explanatory diagram (part 3) of the configuration related to the electrification of the seedling transplanter.

Embodiment for Implementing the Invention

[0009] Hereinafter, embodiments of the seedling transplanter disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments shown below.

[0010] <Overview of the Seedling Transplanter> The overview of the seedling transplanter 1 according to the embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic side view showing the seedling transplanter 1 according to the embodiment.

[0011] In addition, in each figure including FIG. 1, a three-dimensional orthogonal coordinate system including the Z axis with the vertically upward (upward) direction as the positive direction may be shown. Hereinafter, for convenience of explanation, the positive direction of the X axis is defined as the leftward direction, the negative direction of the X axis is defined as the rightward direction, the positive direction of the Y axis is defined as the forward direction, the negative direction of the Y axis is defined as the backward direction, and the X axis direction is referred to as the left-right direction, the Y axis direction is referred to as the front-back direction, and the Z axis direction is referred to as the up-down direction.

[0012] Also, hereinafter, the seedling transplanter 1 and the traveling vehicle body 2 described later may be referred to as the "machine body". The seedling transplanter 1 performs an operation of planting seedlings on the soil surface FS of the field F while traveling forward in the field F.

[0013] As shown in Figure 1, the seedling transplanter 1 comprises a vehicle body 2 and a seedling planting unit 3. The vehicle body 2 is capable of traveling within the field F. The seedling planting unit 3 is a working unit in the seedling transplanter 1 and is mounted on the vehicle body 2. The seedling planting unit 3 plants seedlings on the soil surface FS of the field F. The seedling transplanter 1 is a ride-on type operated by a driver (hereinafter also referred to as an operator). The seedling transplanter 1 may also be a so-called robotic rice transplanter that autonomously travels along a pre-set work path and automatically performs seedling planting work.

[0014] The vehicle body 2 comprises a pair of front wheels 11 and a pair of rear wheels 12. In the vehicle body 2, for example, the pair of front wheels 11 are the steering wheels, and the pair of rear wheels 12 are the drive wheels. In 4WD mode, for example, both the pair of front wheels 11 and the pair of rear wheels 12 become the drive wheels.

[0015] Furthermore, the front of the main frame 13, which forms the body frame of the vehicle body 2, is provided with a transmission case 14 that transmits driving force to the seedling planting unit 3 (described later) and other components, and a hydraulic continuously variable transmission (not shown) that outputs rotational power supplied from a drive source such as the engine E (see Figure 2) to the transmission case 14. The continuously variable transmission is, for example, a hydrostatic continuously variable transmission called an HST (Hydro Static Transmission).

[0016] The transmission case 14 is equipped with a sub-transmission mechanism (not shown) that switches between driving modes, such as when driving on roads or when planting seedlings. In the vehicle body 2, front wheel final drive cases 15 are provided on the left and right sides of the transmission case 14, and the front wheels 11 are attached to the left and right front axles that protrude outward from support parts that can change the steering direction of the left and right front wheel final drive cases 15.

[0017] Furthermore, at the rear of the main frame 13, rear wheel gear cases 16 are provided on the left and right sides of the rear frame which extends in the left-right direction, and rear wheels 12 are attached to the left and right rear axles which protrude outward from the rear wheel gear cases 16.

[0018] Furthermore, the upper part of the rear frame has left and right link support frames 18 that extend upward to support the lifting link 17, which will be described later, located between the vehicle body 2 and the seedling planting section 3. Between the left and right link support frames 18 are left and right upper links 19 and left and right lower link arms 20. Between the left and right upper links 19 and left and right lower link arms 20 in the left and right directions is a hydraulically driven lifting cylinder 21.

[0019] The left and right upper links 19 and left and right lower link arms 20 form a parallel link mechanism called a lifting link 17. The left and right upper links 19, left and right lower link arms 20 and lifting cylinder 21 are each connected at one end to the vehicle body 2 and at the other end to the seedling planting section 3.

[0020] Furthermore, the engine E, which is the drive source, is mounted on the main frame 13. The rotational power of the engine E is transmitted to the transmission case 14 via a belt drive system (not shown) and a continuously variable transmission. The rotational power transmitted to the transmission case 14 is shifted by a sub-transmission mechanism inside the transmission case 14, and then divided into driving power and power to be taken out externally.

[0021] Furthermore, the rotational power of engine E is transmitted to a hydraulic pump (not shown). The hydraulic pressure generated by the hydraulic pump is supplied to the continuously variable transmission, the power steering mechanism 23 of the steering wheel 22 (see Figure 2), the lifting cylinder 21, and the like.

[0022] External power extracted from the rotational power transmitted to the transmission case 14 is transmitted to the planting clutch 24 (see Figure 2) located at the rear of the vehicle body 2, and from the planting clutch 24 to the seedling planting unit 3 via a planting transmission shaft (not shown). Left and right drive shafts (not shown) are provided at the rear of the transmission case 14. Rotational power from the engine E is transmitted to the left and right rear wheel gear cases 16 via the transmission case 14 and the drive shafts.

[0023] Furthermore, upstream of the left and right drive shafts, side clutches 25 (see Figure 2) are provided to engage and disengage power transmission to the left and right drive shafts. As shown in Figure 1, for example, side clutch pedals (not shown) for engaging and disengaging the left and right side clutches 25 are provided at the front lower part of the driver's seat 26 and on the left and right sides.

[0024] By depressing the side clutch pedal on the inside of the turn to disengage the side clutch 25, and then operating the steering wheel 22 to turn, the drive rotation of the rear wheel 12 on the inside of the turn can be interrupted.

[0025] A bonnet 28 housing the engine E is provided in front of the floor step 27 of the vehicle body 2. A control panel 29 is provided at the rear of the bonnet 28. The control panel 29 is equipped with an instrument panel and various controls such as switches. A steering wheel 22 is also provided at the rear of the bonnet 28.

[0026] The bonnet 28 is also equipped with a rotatable steering handle (hereinafter referred to as the handle) 22 for adjusting the steering amount of the front wheels 11, a main transmission lever 30 for operating the continuously variable transmission and seedling planting unit 3, and a sub-transmission lever 31 for operating the sub-transmission mechanism (see Figure 2).

[0027] Furthermore, the hood 28 contains a fuel tank, a battery, and an interlocking mechanism that rotates the left and right front wheels 11 and the lower parts of the left and right front wheel final drive cases 15 in response to the operation of the steering wheel 22. The front part of the hood 28 is covered by an openable and closable front cover 28a.

[0028] A fertilizer application device 40, described later, is provided behind the cockpit 26 and at the rear of the main frame 13. The driving force for the fertilizer application device 40 is transmitted by a fertilizer transmission mechanism, which includes a fertilizer drive shaft 80 (see Figure 7), described later, and is provided so as to face the fertilizer application device 40 from one side of the left and right rear wheel gear cases 16.

[0029] Floor steps 27 are formed on the left and right sides of the lower part of the bonnet 28. The floor steps 27 are approximately horizontal and partially lattice-shaped, so that even if mud from the shoes of the operator (worker) walking on the floor steps 27 falls onto the floor steps 27, the fallen mud will fall into the field F.

[0030] Furthermore, at the front of the vehicle body 2, and on both sides, there is a spare seedling frame 34 in which multiple spare seedling trays 33 are arranged vertically at intervals on seedling frame support columns 32. The spare seedling frame 34 can hold work materials such as seedling mats and fertilizer bags that are supplied to the seedling planting section 3.

[0031] The seedling planting unit 3 is provided at the rear of the vehicle body 2 so as to be able to move up and down. When the seedling planting unit 3 is lowered, it makes contact with the soil surface FS, enabling the planting of seedlings on the soil surface FS. The seedling planting unit 3 does not plant seedlings when it is raised (for example, as shown in the uppermost diagram in Figure 4). The seedling planting unit 3 comprises a seedling tank 35 and a planting device 36.

[0032] The seedling tank 35 holds seedling mats containing seedlings to be planted on the soil surface FS. The seedling tank 35 is connected to the rear end of the lifting link 17. The seedling tank 35 is equipped with fences to divide its upper surface (the surface on which the seedling mats are placed) into multiple sections in the left-right direction. Below the seedling tank 35 is a planting device 36, which includes planting claws 38 that pick up seedlings from the loaded seedling mats and plant the picked-up seedlings on the soil surface FS.

[0033] The planting device 36 comprises a planting transmission case 37, planting claws 38, and a planting rotary 39. In the planting device 36, the planting transmission case 37 is provided below the seedling tank 35 at intervals, and the planting rotary 39 that rotates the planting claws 38 is provided on the left and right sides of the planting transmission case 37. In the planting device 36, the planting claws 38 rotate to pick up seedlings from the seedling mat and plant the picked-up seedlings on the soil surface FS.

[0034] In this manner, the seedling planting unit 3 plants seedlings that have been picked up from the seedling mats transported in the seedling tank 35 by the planting claws 38 onto the soil surface FS while the traveling vehicle body 2 (seedling transplanter 1) is moving forward.

[0035] The fertilizer application device 40 comprises a fertilizer hopper 41, a dispensing device 42, a duct 43, a fertilizer hose (not shown), and a blower (not shown). The fertilizer hopper 41 stores fertilizer. The fertilizer hopper 41 is divided into the same number of sections as the number of working rows in the seedling planting section 3. Note that if the fertilizer hopper 41 is long in the left-right direction, for example, the convenience of loading and unloading fertilizer may be reduced. Therefore, it may also be a so-called side fertilization structure in which the fertilizer hopper 41 is divided into sections representing half of all rows (for example, four rows each in the case of eight rows) and arranged on the left and right sides.

[0036] The dispensing device 42 is provided at the bottom of the fertilizer hopper 41 for each row and supplies fertilizer in set amounts. The duct 43 is provided below the dispensing device 42 and allows the conveying air that moves the fertilizer to pass through. The fertilizer hose is provided below the dispensing device 42 and guides the fertilizer to the vicinity of the seedling planting position in the seedling planting section 3. The blower is provided at one end of the duct 43 and generates the conveying air using the driving force of an electric motor for the blower (not shown).

[0037] A float 44 is provided below the seedling planting section 3. The float 44 comprises a central float 44a and left and right side floats 44b. The center float 44a and the left and right side floats 44b make contact with the soil surface FS of the field F and slide on the soil surface FS as the vehicle body 2 moves forward.

[0038] Furthermore, the seedling planting unit 3 is located in front of the float 44 and is equipped with a leveling rotor 45 for leveling the unevenness of the soil surface FS. The leveling rotor 45 comprises a central rotor 45a and left and right side rotors 45b. The central rotor 45a is located in front of the central float 44a. The side rotors 45b are located in front of each of the left and right side floats 44b. The seedling planting unit 3 plants seedlings on the soil surface FS leveled by the leveling rotor 45. Driving force is transmitted to the leveling rotor 45 via a rotor drive shaft (not shown).

[0039] A fertilizer furrower 46 is provided on the float 44. The fertilizer furrower 46 is connected to a fertilizer hose. The fertilizer furrower 46 forms furrows on the soil surface FS as the vehicle body 2 moves forward. While forming furrows on the soil surface FS, the fertilizer furrower 46 discharges fertilizer from the fertilizer hose into the formed furrows.

[0040] On the left and right sides of the seedling planting unit 3, there are line marking markers that, when one of them touches the soil surface FS of the field F, form a groove (guide line) to serve as a guide for travel in the next work row (next process). When one of the line marking markers lowers and touches the ground, the other rises. Also, when the seedling planting unit 3 is raised during a machine turn, both the left and right line marking markers rise, and when the seedling planting unit 3 is lowered after the machine turn, one of the left or right markers rises while the other lowers (touches the ground).

[0041] Furthermore, a center mascot 47 is erected in the center of the vehicle body 2 in the left-right direction, and in front of the bonnet 28, extending upward. By aligning the center mascot 47 with the guide lines formed on the soil surface FS of the field F by the left and right line markers, it becomes possible to travel in accordance with the working position of the immediately preceding work row, thereby improving work accuracy and preventing the occurrence of non-work.

[0042] Depending on the soil type in field F, the guide lines formed by the left and right line markers may quickly become buried, causing the straight-line guide to disappear. In such cases, it is advisable to use the left and right side markers, which are positioned in front of the left and right line markers. That is, by moving the left and right side markers outwards and positioning them above the seedlings planted in the previous step, it becomes possible to perform planting work in conjunction with the planting of seedlings in the previous work row.

[0043] As shown in Figure 1, the seedling transplanter 1 is equipped with a position information acquisition unit 50. The position information acquisition unit 50 acquires the current position (position information) of the traveling vehicle body 2 (seedling transplanter 1). The position information acquisition unit 50 acquires the current position information of the seedling transplanter 1 using, for example, a satellite positioning system such as GPS (Global Positioning System) or GNSS (Global Navigation Satellite System). The position information acquisition unit 50 may be composed of multiple devices. The position information acquisition unit 50 is supported by, for example, an antenna frame 51 and is positioned above the traveling vehicle body 2.

[0044] The straight-line control program and the turning control program, created based on the position information from the position information acquisition unit 50, are stored in separate locations. The straight-line control program is stored, for example, in the straight-line control ECU (Electronic Control Unit), and the turning control program is stored, for example, in the turning control ECU. The straight-line control ECU and the turning control ECU are included in the control unit 100 (see Figure 2), which will be described later.

[0045] <Control system for seedling transplanter> An example of the control system of the seedling transplanter 1 (see Figure 1) will be described with reference to Figure 2. Figure 2 is a block diagram showing an example of the control system of the seedling transplanter 1 according to an embodiment. As shown in Figure 2, the seedling transplanter 1 (see Figure 1) is capable of controlling each part by electronic control and includes a control unit 100 that controls each part.

[0046] The control unit 100 includes, for example, a processing unit having a CPU (Central Processing Unit), a storage unit such as ROM (Read Only Memory) and RAM (Random Access Memory), and an input / output unit, all of which are connected to each other and can exchange signals. The storage unit stores computer programs for controlling the seedling transplanter 1. The control unit 100 performs its various functions by reading the computer programs stored in the storage unit and other units.

[0047] The control unit 100 is connected to actuators such as a throttle motor 60, hydraulic control valves 61 and 62, a planting clutch operating solenoid 63, a side clutch operating solenoid 64, an HST motor 65, a steering motor 66, a line drawing marker lifting motor 67, and a differential lock switching motor 68.

[0048] The throttle motor 60 increases or decreases the rotational speed of the output shaft of the engine E by operating a throttle that adjusts the intake volume of the engine E. The hydraulic control valve 61 controls the extension and retraction of the lifting cylinder 21. The lifting cylinder 21 drives the lifting link 17, thereby driving the seedling planting unit 3 up and down via the lifting link 17. The hydraulic control valve 62 controls the power steering mechanism 23. The planting clutch operating solenoid 63 operates the planting clutch 24.

[0049] The side clutch operating solenoid 64 operates the side clutch 25, which switches the power transmission state to the rear wheels 12 (see Figure 1). The HST motor 65 changes the tilt angle of the swash plate of the continuously variable transmission (HST) by changing the rotation angle of the HST trunnion. The steering motor 66 steers the front wheels 11 (see Figure 1), which are the steering wheels. The steering motor 66 is the motor that drives the handle 22, which adjusts the amount of steering (also called steering angle or steering angle) of the front wheels 11. The line marking marker lifting motor 67 lifts and lowers the line marking marker.

[0050] The differential lock switching motor 68 is a motor that switches the operation and deactivation of the differential lock mechanism (hereinafter referred to as the differential lock mechanism) 69, which rotates the left and right driving wheels (for example, the left and right front wheels 11) at the same rotational speed. When the differential lock mechanism 69 is activated, the vehicle can be forced into four-wheel drive (4WD mode), and the left and right driving wheels rotate at the same rotational speed.

[0051] Furthermore, the control unit 100 is connected to a rear wheel rotation speed sensor 70, a steering amount sensor 71, a second sensor which is a tilt sensor 72, and a first sensor which is a height sensor 77. Two rear wheel rotation speed sensors 70 are provided, one for each of the left and right rear wheels 12, and each detects the rotation speed of the left and right rear wheels 12.

[0052] The steering amount sensor 71 detects the rotation of the steering wheel 22, that is, the amount of steering of the front wheels 11 (see Figure 1). The steering amount sensor 71 is mounted, for example, on an axis connected to the pitman arm. The control unit 100 controls the steering wheel 22 via the steering motor 66 based on the detection result of the steering amount sensor 71. While controlling the steering wheel 22, the control unit 100 performs straight-line control and turning control of the vehicle body 2 based on the position information of the vehicle body 2 acquired by the position information acquisition unit 50.

[0053] The second sensor, the tilt sensor 72, detects the tilt angle (including at least the pitch angle) of the seedling transplanter 1 (traveling vehicle body 2). The first sensor, the height sensor 77, is installed on the lifting link 17 and detects the height of the movable seedling planting section 3.

[0054] Furthermore, the control unit 100 receives signals as operation signals from, for example, the main speed shift lever 30, the sub-speed shift lever 31, the seedling planting unit lifting switch 73, the line marking marker automatic lifting switch 74, the automatic rotation switching switch 75, the mode switching switch 76, the first operating device, the ridge-gathering switch 78, and the second operating device, the lifting lever 79.

[0055] The seedling planting unit lifting switch 73 is a switch that switches the seedling planting unit 3 up and down. The seedling planting unit lifting switch 73 can be changed to an "up" or "down" position. When the seedling planting unit lifting switch 73 is in the "up" position, the seedling planting unit 3 rises to a predetermined non-working position, and the planting device 36 (see Figure 1) stops, resulting in a non-working state (seedling planting unit 3 is off). When the seedling planting unit lifting switch 73 is in the "down" position, the seedling planting unit 3 lowers to a predetermined working position, and the planting device 36 operates, resulting in a working state (seedling planting unit 3 is on). In other words, the seedling planting unit lifting switch 73 is a switch that can detect the working state of the seedling planting unit 3.

[0056] The automatic line marking marker lifting switch 74 is a switch that toggles whether or not to automatically raise and lower the line marking marker in conjunction with the steering amount of the steering wheel 22 (i.e., the steering amount of the front wheels 11). When the automatic line marking marker lifting switch 74 is "ON", control is performed to automatically raise and lower the line marking marker in conjunction with the steering amount. On the other hand, when the automatic line marking marker lifting switch 74 is "OFF", control is not performed to automatically raise and lower the line marking marker in conjunction with the steering amount.

[0057] The automatic turning switch 75 is a switch that enables or disables automatic turning when the operator (worker) manually operates the seedling transplanter 1. When the automatic turning switch 75 is "ON", automatic turning is enabled. When the automatic turning switch 75 is "OFF", automatic turning is disabled. The mode switch 76 is a switch that enables or disables autonomous driving of the seedling transplanter 1 (vehicle body 2).

[0058] The first operating device, the ridge-feeding switch 78, is, for example, a button switch provided on the control panel 29. The ridge-feeding switch 78 is pressed by the operator when raising or lowering the seedling planting unit 3 via the lifting link 17. The ridge-feeding switch 78 is also pressed by the operator when causing the control unit 100 to perform the special lifting and lowering control of the seedling planting unit 3, which will be described later.

[0059] The second operating device, the lifting lever 79, is, for example, a finger lever switch provided on the grip of the main speed shift lever 30, which can be operated by the operator (worker) with their fingers. The lifting lever 79 switches the raising and lowering of the seedling planting unit 3 in substantially the same way as the seedling planting unit lifting switch 73. That is, the lifting lever 79 can be changed to an "up" and "down" position. When the lifting lever 79 is raised, the seedling planting unit 3 rises to a predetermined non-working position, and the planting device 36 (see Figure 1) stops, resulting in a non-working state (seedling planting unit 3 off). Conversely, when the lifting lever 79 is lowered, the seedling planting unit 3 lowers to a predetermined working position, and the planting device 36 operates, resulting in a working state (seedling planting unit 3 on).

[0060] Here, during the seedling planting process, in order to plant as many seedlings as possible in field F, the plants should be planted as close as possible to the ridge R (see Figure 3), that is, at the edge of the ridge FS on the soil surface FS (see Figure 3). R (See Figure 3) The operation to start planting seedlings is performed, but the seedling planting unit 3 is at the edge of the ridge FS R Operating the device to lower it to the appropriate position may require, for example, skill. In this embodiment, the operator (worker) moves the seedling planting unit 3 to the edge of the ridge FS R This configuration makes it easy to move the object towards the object.

[0061] As described above, the control unit 100 controls the raising and lowering of the seedling planting unit 3. In other words, the control unit 100 functions as a lifting and lowering control unit. The control unit 100, which is the lifting and lowering control unit, moves the seedling planting unit 3 to the edge FS R To begin planting seedlings after moving them closer, the vehicle body 2 is positioned at the edge of the ridge (FS). R When the vehicle is moving in reverse towards the destination, a special lifting control is performed to control the raising and lowering of the seedling planting unit 3.

[0062] <Seedling planting using a seedling transplanter> The seedling planting operation using the seedling transplanter 1 according to this embodiment will be explained with reference to Figure 3. Figure 3 is an explanatory diagram of the seedling planting operation using the seedling transplanter 1 according to this embodiment.

[0063] As shown in Fig. 3, in the operation of planting seedlings by the seedling transplanter 1, when the seedling transplanter 1 that plants seedlings on the soil surface FS while moving forward in the field F approaches the ridge R, the operator operates the handle 22 (see Fig. 1) in front of the ridge R, so that the seedling planting part 3 rises and rotates in the state where the seedling planting part 3 has risen. When the turning of the seedling transplanter 1 is completed, the seedling planting part 3 is moved backward while rising to approach the edge FS of the ridge R of the seedling planting part 3 to the edge FS of the ridge. Then, at the appropriate position of the edge FS R of the ridge, the seedling planting part 3 is lowered and the forward movement is started, thereby starting the planting of seedlings in the next working row.

[0064] The control unit 100 (see Fig. 2) performs special lifting and lowering control of the seedling planting part 3 when the seedling planting part 3 that has completed the turning of the seedling transplanter 1 moves backward toward the edge FS of the ridge while in the raised state R of the ridge.

[0065] <Special lifting and lowering control by the lifting and lowering control unit> The special lifting and lowering control of the seedling planting part 3 by the control unit 100, which is the lifting and lowering control unit, will be described with reference to Figs. 4 to 6. Figs. 4 to 6 are explanatory diagrams of the special lifting and lowering control by the lifting and lowering control unit (control unit 100).

[0066] In the special lifting and lowering control of the seedling planting part 3 by the control unit 100, when the operator operates the ridge approaching switch 78 on the operation panel 29 as shown in Fig. 4 when the seedling transplanter 1 that has completed the turning at the side of the ridge R moves backward toward the edge FS of the ridge on the soil surface FS R of the ridge, the control unit 100 first grounds the seedling planting part 3 on the soil surface FS, and then positions (raises) the seedling planting part 3 at a height close to but not in contact with the soil surface FS.

[0067] In this case, when the height sensor 77, which is the first sensor, detects the height of the seedling planting unit 3 when it is lowered and touches the soil surface FS by the operator's operation of the ridge-raising switch 78, the control unit 100 raises the seedling planting unit 3 to a position that is a predetermined amount (predetermined height) H from the height detected by the height sensor 77. The predetermined height H is at least lower than the position where the seedling planting unit 3 has risen to a predetermined non-working position.

[0068] The control unit 100 sets a predetermined height H to a height at which the fertilizer furrower 46 (see Figure 1) does not come into contact with the soil surface FS. This allows the seedling planting unit 3 to be positioned at the edge of the ridge FS. R When the vehicle body 2 is moved in reverse to move closer to the fertilizer, it is possible to suppress mud clogging in the fertilizer furrower 46 and fertilizer clogging due to mud clogging.

[0069] Then, after the operator performs special lifting and lowering control of the seedling planting unit 3 by the control unit 100, the operator moves the seedling transplanter 1 to the edge of the ridge FS. R Drive in reverse towards that direction.

[0070] With this configuration, the seedling planting section 3 is located at the edge of the ridge FS. R To begin planting seedlings, move vehicle body 2 to the edge of the ridge (FS). R When moving the machine in reverse, the operator positions the seedling planting unit 3 at the edge of the ridge FS. R The vehicle body 2 can reverse while comparing the seedling planting unit 3 with the ridge R, allowing the operator to move the seedling planting unit 3 to the edge of the ridge FS. R This makes it easier to move the plant closer to the edge of the ridge (FS). R This allows for reliable and easy planting of seedlings from a position as close as possible to the ridge (ridge edge FS). R By planting seedlings from the field F, it becomes possible to plant many seedlings in the field F, thereby increasing the yield of crops (rice) relative to the area of ​​field F.

[0071] Furthermore, the height of the seedling planting unit 3 is detected when it descends and touches the soil surface FS. By raising the seedling planting unit 3 to a position where it has changed by a predetermined amount (predetermined height) H from the detected height, an appropriate height for the seedling planting unit 3 can be set with respect to the soil surface FS. This stabilizes the height of the seedling planting unit 3, allowing the vehicle body 2 to move along the edge of the ridge FS. R It allows for safe reverse movement towards the destination and improves work efficiency.

[0072] The control unit 100 can adjust a predetermined height H for raising the seedling planting unit 3 in special lifting control. That is, the control unit 100 can adjust the predetermined height H according to the condition of the field F (for example, the unevenness of the soil surface FS).

[0073] Thus, since the predetermined amount (predetermined height) H (i.e., the amount of change) that raises the seedling planting section 3 can be adjusted, the adaptability to field F can be improved by adjusting this amount of change.

[0074] After the ridge-feeding switch 78 is operated to switch to special lifting control, as shown in Figure 5, the control unit 100 performs special lifting control by lowering the seedling planting unit 3 using the lifting lever 79, which is the second operating tool of the main speed shift lever 30, by the operator. That is, the control unit 100 lowers the seedling planting unit 3 by lowering it with the lifting lever 79, causing it to touch the soil surface FS, and then raises the seedling planting unit 3 to a position that has changed to a predetermined height H.

[0075] This configuration makes it possible to suppress erroneous operation of the operating device (mainly the first operating device, the ridge switch 78) after transitioning to special lifting control, thereby improving safety.

[0076] Furthermore, as shown in Figure 6, the control unit 100 can detect, for example, unevenness in the soil surface (for example, steps FS). SWhen the rear wheels 12 ride up onto the ) and the vehicle body 2 (seedling transplanter 1) tilts in the front-to-back direction, the seedling planting section 3 is raised and lowered so that the height of the seedling planting section 3 from the soil surface FS maintains a predetermined height H.

[0077] When the seedling planting unit 3 is raised to a predetermined height H, the control unit 100 controls the raising and lowering of the seedling planting unit 3 based on the amount of change in the tilt detected by the tilt sensor 72 (see Figure 2), which is the second sensor, when the vehicle body 2 subsequently moves forward or backward, so that the height from the soil surface FS becomes the predetermined height H.

[0078] With this configuration, the unevenness of the soil surface FS (step FS) S The height of the seedling planting section 3 can be stabilized against the tilt of the vehicle body 2 in the front-rear direction caused by factors such as the above.

[0079] <Transmission configuration to the fertilizer drive shaft> The transmission configuration to the fertilizer drive shaft 80 for driving the fertilizer applicator 40 (see Figure 1) will be explained with reference to Figure 7. Figure 7 is a diagram showing the transmission configuration to the fertilizer drive shaft 80.

[0080] The fertilizer applicator 40 is driven by rotational power from the fertilizer drive shaft 80. The seedling transplanter 1 is equipped with a transmission configuration for transmitting rotational power to the fertilizer drive shaft.

[0081] As shown in Figure 7, the power transmission configuration to the fertilizer drive shaft 80 includes a drive motor 81, a driven shaft 82, a gear 83, a torque limiter 84, and a one-way clutch 85. One drive motor 81 is provided. The drive motor 81 includes a motor output shaft 81a. The motor output shaft 81a is mounted coaxially with respect to the fertilizer drive shaft 80. The motor output shaft 81a provides rotational power to the fertilizer drive shaft 80.

[0082] The driven shaft 82 is mounted parallel to the motor output shaft 81a and the fertilizer drive shaft 80, respectively. The gear 83 consists of four gears, each having an arbitrary number of teeth. The gear 83 comprises a large gear 83a with a larger diameter and a small gear 83b with a smaller diameter than the large gear 83a. The gear 83 is mounted on the motor output shaft 81a, the fertilizer drive shaft 80, and the driven shaft 82, and transmits rotational power between the motor output shaft 81a and the driven shaft 82, and between the fertilizer drive shaft 80 and the driven shaft 82.

[0083] The torque limiter 84 is provided between the motor output shaft 81a and the fertilizer drive shaft 80. The one-way clutch 85 is provided between the torque limiter 84 and the fertilizer drive shaft 80.

[0084] In the power transmission configuration to the fertilizer drive shaft 80, the rotational power output from the motor output shaft 81a of the drive motor 81 is transmitted to the torque limiter 84 and also to the driven shaft 82 by the gears 83 (large gear 83a, small gear 83b). The rotational power transmitted to the torque limiter 84 is then transmitted to the fertilizer drive shaft 80. The rotational power transmitted to the driven shaft 82 is then transmitted to the fertilizer drive shaft 80 by the gears 83 (large gear 83a, small gear 83b). In the power transmission configuration to the fertilizer drive shaft 80, the rotational power transmitted to the fertilizer drive shaft 80 is switched on and off by the one-way clutch 85.

[0085] With this configuration, the fertilizer drive shaft 80 is rotationally driven by a single drive motor 81, making it possible to change the reduction ratio between the drive motor 81 and the fertilizer drive shaft 80. For example, if the load on the fertilizer drive shaft 80 increases due to fertilizer clogging in the fertilizer applicator 40, the speed will shift to a larger reduction ratio. This makes it easy to secure torque that can cope with the increased load on the fertilizer drive shaft 80.

[0086] Furthermore, by arranging four gears 83 (large gear 83a, small gear 83b) that transmit rotational power between the motor output shaft 81a and the driven shaft 82, and between the fertilizer drive shaft 80 and the driven shaft 82, a configuration is created that generates rotational power with a reduced rotational speed of the motor output shaft 81a. This makes it possible to provide two different outputs with a single drive motor 81.

[0087] Furthermore, by positioning a torque limiter 84 between the motor output shaft 81a and the fertilizer drive shaft 80, the torque limiter 84 will slip when a load is applied to the fertilizer drive shaft 80, causing a mechanical speed change. This allows for a mechanical speed change when the load on the fertilizer drive shaft 80 increases, eliminating the need to control the drive motor 81.

[0088] <Configuration of an electric rotor (ground leveling rotor)> The configuration of the electric rotor, the leveling rotor 45, will be explained with reference to Figures 8-10. Figures 8-10 are explanatory diagrams of the configuration of the electric rotor (leveling rotor 45). Figure 8 is a schematic perspective view of the leveling rotor 45 from above, Figure 9 is a schematic plan view of the leveling rotor 45, and Figure 10 is a schematic side view (left side view) of the leveling rotor 45.

[0089] In the seedling transplanter 1 (see Figure 1), the soil leveling rotor 45 is driven by the driving force from the rotary drive motor 91 (see Figure 8) and the lifting drive motor 92 (see Figure 9), which will be described later. Thus, the soil leveling rotor 45 is an electric rotor. As described above, the electric soil leveling rotor 45 comprises a center rotor 45a and left and right side rotors 45b.

[0090] The seedling transplanter 1 is equipped with an actuator 90 for driving the soil leveling rotor 45.

[0091] As shown in Figure 8, the actuator 90 comprises a rotary drive motor 91 and a lifting drive motor 92 (see Figure 9). The rotary drive motor 91 provides rotational driving force to the center rotor 45a and the side rotors 45b of the leveling rotor 45, respectively. The rotary drive motor 91 is located behind the center rotor 45a. The rotary drive motor 91 is located above the center rotor 45a.

[0092] Furthermore, the rotary drive motor 91 is installed on either the left or right side of the side rotor 45b. The rotary drive motor 91 is located closer to the center of the aircraft in the left-right direction than the side rotor 45b on which the rotary drive motor 91 is installed. The rotary drive motor 91 is located above the side rotor 45b on which the rotary drive motor 91 is installed.

[0093] Furthermore, as shown in Figure 9, the rotary drive motor 91 is located on the opposite side of the lifting drive motor 92, with the center of the machine in the left-right direction in between. In other words, the rotary drive motor 91 and the lifting drive motor 92 are located on opposite sides of the center of the machine in the left-right direction to one of the two.

[0094] With this configuration, the rotary drive motor 91 is located behind the center rotor 45a, allowing for efficient use of space. Also, because the rotary drive motor 91 is located above the center rotor 45a, it is possible to prevent water from entering the rotary drive motor 91. Furthermore, because the rotary drive motor 91 is located towards the center of the machine in the left-right direction compared to the side rotors 45b, efficient use of space is possible. Also, because the rotary drive motor 91 is located above the side rotors 45b, it is possible to prevent water from entering the rotary drive motor 91. In addition, the arrangement of the rotary drive motor 91 and the lifting drive motor 92 on opposite sides of the center of the machine in the left-right direction results in good weight balance.

[0095] As shown in Figure 10, when the leveling rotor 45 is set to level a position deeper than the standard position on the soil surface FS, the control unit 100 (see Figure 2) controls the rotary drive motor 91 (see Figure 8) so that the leveling rotor 45 rotates at a faster rotational speed than the rotational speed at the standard position. This suppresses mud pushing by the leveling rotor 45 when leveling deeper than the standard position.

[0096] Furthermore, if the leveling rotor 45 is set to a position deeper than the standard position, the control unit 100 controls the rotary drive motor 91 so that it rotates with the same circumference as the contact point of the virtual circle that contacts the soil surface FS at a position deeper than the standard position. This suppresses mud pushing by the leveling rotor 45 when it is deeper than the standard position.

[0097] Furthermore, if a switch is provided that rotates the leveling rotor 45 using the rotational power of the PTO (Power Take-Off), the control unit 100 rotates the leveling rotor 45 at a specified rotational speed when the switch is operated. This makes it possible to rotate the leveling rotor 45 while the seedling transplanter 1 is stopped during cleaning, thus facilitating the cleaning of the leveling rotor 45.

[0098] Furthermore, if a switch is provided to switch the rotation direction of the leveling rotor 45 using the rotational power of the PTO, the control unit 100 will rotate the leveling rotor 45 at a specified rotational speed in the reverse direction when the switch is operated. This makes it possible to easily remove any debris that has become entangled in the leveling rotor 45 by rotating it in the reverse direction.

[0099] Furthermore, when the control unit 100 sets the continuously variable transmission (HST) to the forward position using the PTO, it rotates the leveling rotor 45 in the forward direction in accordance with the opening of the continuously variable transmission (HST). This makes it possible to rotate the leveling rotor 45 while the seedling transplanter 1 is stopped during cleaning, thus facilitating the cleaning of the leveling rotor 45.

[0100] Furthermore, when the PTO sets the continuously variable transmission (HST) to the reverse position, the control unit 100 reverses the rotation of the leveling rotor 45 in accordance with the opening of the HST. This makes it easy to remove any debris that becomes entangled in the leveling rotor 45 by reversing its rotation.

[0101] Furthermore, if the "cleaning mode" for the leveling rotor 45 is set, the control unit 100 operates a predetermined switch to repeatedly rotate the rotor in both forward and reverse directions at high speed. This suppresses the lifting of mud by the leveling rotor 45, thereby reducing the amount of mud adhering to the leveling rotor 45 and making it easier to clean the leveling rotor 45.

[0102] <Configuration related to the electrification of seedling transplanters> The configuration of the motorization of the seedling transplanter 1 will be explained with reference to Figures 11-13. Figures 11-13 are explanatory diagrams of the configuration of the motorization of the seedling transplanter 1. Figure 11 is a schematic front view of the seedling transplanter 1, Figure 12 is a schematic rear view of the seedling transplanter 1, and Figure 13 is a schematic perspective view of the seedling transplanter 1 from above.

[0103] As shown in Figure 11, in the seedling transplanter 1, for example, the all-solid-state battery may be placed inside the bonnet 28 at the front of the machine. This minimizes changes in the machine's weight balance. Alternatively, in the seedling transplanter 1, for example, the all-solid-state battery may be placed in place of the weight at the front of the machine where the weight would normally be located. This reduces the number of parts.

[0104] Furthermore, as shown in Figure 12, in the seedling transplanter 1, for example, the seedling feeding in the seedling tank 35 may be motorized by driving an ultrasonic motor. This makes it possible to miniaturize the seedling tank 35. In this case, by arranging the ultrasonic motor at either the left or right end of the seedling tank 35, all rows in the seedling tank 35 can be driven by a single motor. Alternatively, for example, by arranging an ultrasonic motor on the seedling feeding drive shaft for each row, the feeding of each row can be controlled individually.

[0105] Furthermore, the seedling transplanter 1 may be configured to reverse the rotation of the seedling feed belt 35a for any row in the seedling tank 35 to pull up the seedling mat to a position where the seedlings will not be picked up. This eliminates the need for control by the ridge clutch and allows planting of seedlings in any row to be stopped even when all planting claws 38 are operating.

[0106] Furthermore, as shown in Figure 13, the seedling transplanter 1 may use solar panels to secure power, for example. In this case, for example, the uppermost of the multiple spare seedling trays 33 may be made into a solar panel. Alternatively, for example, the lid of the fertilizer hopper 41 may be made into a solar panel. Alternatively, for example, the auxiliary seedling frame of the seedling tank 35 may be made into a solar panel.

[0107] Based on the embodiments described above, the following seedling transplanter 1 is realized.

[0108] (1) The vehicle comprises a vehicle body 2 capable of traveling within a field F, a seedling planting unit 3 mounted at the rear of the vehicle body 2 so as to be able to move up and down, and which, when lowered, plants seedlings on the soil surface FS of the field F while the vehicle body 2 is moving forward, and a lifting control unit 100 that controls the raising and lowering of the seedling planting unit 3, the lifting control unit 100 controls the seedling planting unit 3 to the edge FS of the field F R To begin planting seedlings, the vehicle body 2 moves to the edge of the ridge FS. R A seedling transplanter 1 that performs special lifting control to position the seedling planting unit 3 at a height close to the soil surface FS without touching it when moving in reverse toward the soil surface FS.

[0109] With this type of seedling transplanter 1, the seedling planting section 3 is placed at the edge of the ridge FS. R To begin planting seedlings, move vehicle body 2 to the edge of the ridge (FS). R When moving the machine in reverse, the operator positions the seedling planting unit 3 at the edge of the ridge FS. R The vehicle body 2 can reverse while comparing the seedling planting unit 3 with the ridge R, allowing the operator to move the seedling planting unit 3 to the edge of the ridge FS. RThis makes it easier to move the plant closer to the edge of the ridge (FS). R This allows for reliable and easy planting of seedlings from a position as close as possible to the ridge (ridge edge FS). R By planting seedlings from the field F, it becomes possible to plant many seedlings in the field F, thereby increasing the yield of crops (rice) relative to the area of ​​field F.

[0110] (2) The seedling transplanter 1, wherein the lifting control unit 100 is provided between the traveling vehicle body 2 and the seedling planting unit 3 and drives the seedling planting unit 3 up and down, a lifting link 17 provided on the lifting link 17 and a first sensor 77 for detecting the height of the seedling planting unit 3, and a first operating tool 78 which is operated when the seedling planting unit 3 is raised or lowered via the lifting link 17, and in special lifting control, when the height of the seedling planting unit 3 when the seedling planting unit 3 is lowered by the operation of the first operating tool 78 and touches the soil surface FS is detected by the first sensor 77, the lifting control unit 100 raises the seedling planting unit 3 to a position that has changed by a predetermined amount H from the height detected by the first sensor 77.

[0111] With this type of seedling transplanter 1, in addition to the effects of (1) above, the height of the seedling planting unit 3 is detected when the seedling planting unit 3 descends and touches the soil surface FS, and the seedling planting unit 3 is raised to a position that has changed by a predetermined amount H from the detected height, thereby setting an appropriate height for the seedling planting unit 3 with respect to the soil surface FS. This stabilizes the height of the seedling planting unit 3, and allows the traveling vehicle body 2 to reach the edge of the ridge FS R It allows for safe reverse movement towards the destination and improves work efficiency.

[0112] (3) In the above (2), when the lifting control unit 100 raises the seedling planting unit 3 to a position that has changed by a predetermined amount H from the height detected by the first sensor 77, the predetermined amount H to raise the seedling planting unit 3 is adjustable, the seedling transplanter 1.

[0113] With this type of seedling transplanter 1, in addition to the effects of (2) above, the predetermined amount H (i.e., the amount of change) that raises the seedling planting section 3 can be adjusted, and by adjusting this amount of change, the adaptability to field F can be improved.

[0114] (4) The seedling transplanter 1, wherein the seedling transplanter 1 is equipped with a second operating tool 79 which is different from the first operating tool 78 and is operated when raising or lowering the seedling planting section 3 via the lifting link 17, and after the first operating tool 78 is operated in order to transition to special lifting control, the lifting control unit 100 lowers the seedling planting section 3 by operating the second operating tool 79 to lower the seedling planting section 3 and brings it into contact with the soil surface FS, and raises the seedling planting section 3 to a position where it has changed by a predetermined amount H.

[0115] With this seedling transplanter 1, in addition to the effects of (3) above, it is possible to suppress erroneous operation of the operating device (mainly the first operating device 78) after transitioning to special lifting control, thereby improving safety.

[0116] (5) The seedling transplanter 1, wherein the seedling transplanter 1 comprises a float 44 provided at the lower part of the seedling planting section 3, and a fertilizer applicator 40 that discharges fertilizer to the soil surface FS via a fertilizer furrower 46 provided on the float 44 when planting seedlings with the seedling planting section 3, and the lifting control unit 100 raises the seedling planting section 3 by a predetermined amount H to a height at least such that the fertilizer furrower 46 does not come into contact with the soil surface FS.

[0117] With this type of seedling transplanter 1, in addition to the effects of (4) above, the seedling planting section 3 is positioned at the edge of the ridge FS. R When the vehicle body 2 is moved in reverse to move closer to the fertilizer, it is possible to suppress mud clogging in the fertilizer furrower 46 and fertilizer clogging due to mud clogging.

[0118] (6) In any of the above (3) to (5), a second sensor 72 is provided to detect the tilt of the vehicle body 2 in the front-rear direction, and the lifting control unit 100 controls the lifting of the seedling planting unit 3 so that the height from the soil surface FS becomes a predetermined amount H, based on the amount of change in the tilt of the vehicle body 2 when the vehicle body 2 moves forward or backward, in addition to the tilt detected by the second sensor 72 when the vehicle body 2 is raised by a predetermined amount.

[0119] With this type of seedling transplanter 1, in addition to any of the effects of (3) to (5) above, the unevenness of the soil surface FS (step FS) is also improved. S The height of the seedling planting section 3 can be stabilized against the tilt of the vehicle body 2 in the front-rear direction caused by factors such as the above.

[0120] (7) The seedling transplanter 1, as described in (1) above, comprising: a fertilizer drive shaft 80 for driving a fertilizer applicator 40 that discharges fertilizer onto the soil surface FS when seedlings are planted by the seedling planting unit 3; a drive motor 81 having a motor output shaft 81a for supplying rotational power to the fertilizer drive shaft 80; a driven shaft 82 provided parallel to the motor output shaft 81a and the fertilizer drive shaft 80; four gears 83 (83a, 83b) each having an arbitrary number of teeth, provided on the motor output shaft 81a, the fertilizer drive shaft 80 and the driven shaft 82, and for transmitting power between the motor output shaft 81a and the driven shaft 82, and between the fertilizer drive shaft 80 and the driven shaft 82; and a torque limiter 84 provided between the motor output shaft 81a and the fertilizer drive shaft 80.

[0121] With this seedling transplanter 1, in addition to the effects of (1) above, the fertilizer drive shaft 80 is rotationally driven by a single drive motor 81, making it possible to change the reduction ratio between the drive motor 81 and the fertilizer drive shaft 80. For example, if the load on the fertilizer drive shaft 80 increases due to fertilizer clogging in the fertilizer device 40, the speed will shift to a larger reduction ratio. This makes it easy to secure torque that can cope with the increased load on the fertilizer drive shaft 80.

[0122] Furthermore, by arranging four gears 83 (83a, 83b) that transmit rotational power between the motor output shaft 81a and the driven shaft 82, and between the fertilizer drive shaft 80 and the driven shaft 82, a configuration is created that generates rotational power with a reduced rotational speed of the motor output shaft 81a. This makes it possible to provide two different outputs with a single drive motor 81.

[0123] Furthermore, by positioning a torque limiter 84 between the motor output shaft 81a and the fertilizer drive shaft 80, the torque limiter 84 will slip when a load is applied to the fertilizer drive shaft 80, causing a mechanical speed change. This allows for a mechanical speed change when the load on the fertilizer drive shaft 80 increases, eliminating the need to control the drive motor 81.

[0124] (8) The seedling transplanter 1 having, in the above (1), a center rotor 45a and left and right side rotors 45b provided on the left and right sides of the center rotor 45a, a leveling rotor 45 for leveling the soil surface FS when planting seedlings with the seedling planting unit 3, a rotary drive motor 91 for applying rotational driving force to the leveling rotor 45, and a lifting drive motor 92 for applying lifting driving force to the leveling rotor 45, an actuator 90 for driving the leveling rotor 45, wherein the rotary drive motor 91 is located behind and above the center rotor 45a, and is located on the left and right side of the machine body and above the side rotors 45b, and the rotary drive motor 91 and the lifting drive motor 92 are located on opposite sides of the left and right center of the machine body to one of them.

[0125] With this seedling transplanter 1, in addition to the effects of (1) above, space can be used effectively because the rotary drive motor 91 is located behind the center rotor 45a. Also, because the rotary drive motor 91 is located above the center rotor 45a, water entering the rotary drive motor 91 can be suppressed. Also, because the rotary drive motor 91 is located towards the center of the machine in the left-right direction compared to the side rotors 45b, space can be used effectively. Also, because the rotary drive motor 91 is located above the side rotors 45b, water entering the rotary drive motor 91 can be suppressed. Furthermore, because the rotary drive motor 91 and the lifting drive motor 92 are positioned on opposite sides of the center of the machine in the left-right direction, the weight balance is improved.

[0126] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0127] 1 Seedling transplanter 2. Running vehicle 3 Seedling planting department 17 Lifting Link 40 Fertilizer application equipment 44 floats 45. Ground leveling rotor 45a Center Rotor 45b Side Rotor 46 Fertilizer furrow equipment 72. Second sensor (tilt sensor) 77. First sensor (height sensor) 78. First operating device (ridge-side switch) 79. Second operating device (lifting lever) 80 Fertilizer drive shaft 81 Drive motor 81a Motor output shaft 82 Driven axis 83 Gears 84 Torque Limiter 90 Actuators 91 Rotary drive motor 92 Lifting drive motor 100 Lifting and Lowering Control Unit (Control Unit) Field F FS soil surface FS R Ridge edge H A predetermined amount (a predetermined height) R ridge

Claims

1. A vehicle capable of traveling within a field, A seedling planting unit is provided at the rear of the vehicle body so as to be able to move up and down, and when lowered, it plants seedlings on the soil surface of the field while the vehicle body is moving forward. A lifting control unit that controls the raising and lowering of the seedling planting unit, A lifting link is provided between the vehicle body and the seedling planting section, and drives the seedling planting section to move up and down. A first sensor is provided on the lifting link for detecting the height of the seedling planting section, A first operating tool that is operated when raising or lowering the seedling planting section via the aforementioned lifting link, Equipped with, The aforementioned lifting control unit, When the vehicle body is moved in reverse toward the edge of the field to begin planting seedlings after bringing the seedling planting unit close to the edge of the field, a special lifting control is performed to position the seedling planting unit at a height close to the soil surface without touching it. The aforementioned lifting control unit, In the special lifting control described above, when the height of the seedling planting unit when it has been lowered by the operation of the first operating tool and is in contact with the soil surface is detected by the first sensor, the seedling planting unit is raised to a position that has changed by a predetermined amount from the height detected by the first sensor. The aforementioned lifting control unit, When raising the seedling planting unit from the height detected by the first sensor to a position that has changed by a predetermined amount, the predetermined amount by which the seedling planting unit is raised is adjustable. A second sensor that detects the tilt of the vehicle body in the front-rear direction. Furthermore, The aforementioned lifting control unit, When the seedling planting unit is raised by the predetermined amount, the tilt detected by the second sensor changes as the vehicle body moves forward or backward. In such cases, the raising and lowering of the seedling planting unit is controlled based on the amount of change in the vehicle body's tilt so that the height from the soil surface becomes the predetermined amount. A seedling transplanter characterized by the following features.

2. A second operating tool, which is different from the first operating tool, and is operated when raising or lowering the seedling planting section via the lifting link. Equipped with, The aforementioned lifting control unit, After the first operating tool is operated to transition to the special lifting control, the seedling planting section is lowered by the operation of the second operating tool, bringing it into contact with the soil surface, and then the seedling planting section is raised to the predetermined position. The seedling transplanter according to feature 1.

3. A float is provided at the lower part of the seedling planting section, When planting seedlings using the seedling planting unit, a fertilizer applicator is provided on the float to discharge fertilizer onto the soil surface via a fertilizer furrower. Equipped with, The aforementioned lifting control unit, The predetermined amount by which the seedling planting section is raised is set to a height at least such that the fertilizer furrower does not come into contact with the soil surface. The seedling transplanter according to feature 2.

4. A fertilizer drive shaft for driving a fertilizer application device that discharges fertilizer onto the soil surface when planting seedlings using the seedling planting unit, A drive motor having a motor output shaft that provides rotational power to the fertilizer drive shaft, A driven shaft provided parallel to the motor output shaft and the fertilizer drive shaft, Four gears, each having an arbitrary number of teeth, are provided on the motor output shaft, the fertilizer drive shaft, and the driven shaft, and transmit power between the motor output shaft and the driven shaft, and between the fertilizer drive shaft and the driven shaft. A torque limiter is provided between the motor output shaft and the fertilizer drive shaft. Equipped with The seedling transplanter according to feature 1.

5. It has a center rotor and left and right side rotors provided on the left and right sides of the center rotor, and a leveling rotor that levels the soil surface when planting seedlings with the seedling planting unit, The system includes a rotary drive motor that provides rotational driving force to the leveling rotor, and a lifting drive motor that provides lifting driving force to the leveling rotor, and an actuator that drives the leveling rotor. Equipped with, The aforementioned rotary drive motor is Located behind and above the center rotor, and located towards the center of the aircraft and above the side rotors in the left-right direction, The aforementioned rotary drive motor and the aforementioned lifting drive motor are One is positioned on the opposite side of the aircraft's center in the left-right direction from the other. The seedling transplanter according to feature 1.

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