Work vehicles

Abstract

To provide a work vehicle that can reduce the labor involved in supplying seedlings to seedling tanks. [Solution] A work vehicle according to one embodiment comprises a vehicle body that travels on a field, a seedling tank provided at the rear of the vehicle body on which seedlings are loaded, an extension seedling tank provided on top of the seedling tank, a seedling planting unit that plants seedlings taken from the seedlings loaded in the seedling tank into the field, a seedling transport device provided above the vehicle body that transports seedlings to the extension seedling tank, and a control device that controls the operation of the seedling tank, the seedling planting unit and the seedling transport device. The seedling transport device is provided every other row for half the number of planting rows in the seedling planting unit, the tip of the extension seedling tank approaches the rear end of the seedling transport device when the seedling tank is raised, and the control device moves the seedling tank to one side in the left-right direction to supply seedlings to the even-numbered rows of the seedling planting unit by the seedling transport device, and moves the seedling tank to the other side in the left-right direction to supply seedlings to the odd-numbered rows of the seedling planting unit by the seedling transport device.

Description

Technical Field

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

Background Art

[0002] Conventionally, there is known a work vehicle in which a seedling planting device is connected to the rear part of a passenger-type traveling body having front wheels and rear wheels so as to be able to move up and down via a parallel four-link mechanism driven by a hydraulic cylinder (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above prior art, when the seedlings loaded on the seedling tank (seedling stand) are consumed, it is necessary to perform an operation of supplying the seedlings to the seedling tank. Therefore, labor saving in the operation of supplying the seedlings to the seedling tank has been demanded.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a work vehicle capable of saving labor in the operation of supplying seedlings to a seedling tank.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, a work vehicle (1) according to one embodiment includes a vehicle body (2) that travels in a field, a seedling tank (53) provided behind the vehicle body (2) on which seedlings are loaded, an extended seedling tank (54) provided above the seedling tank (53), a seedling planting unit (4) that plants seedlings taken from the seedlings loaded in the seedling tank (53) in the field, and a seedling transport device (110) provided above the vehicle body (2) that transports seedlings to the extended seedling tank (54). The system includes a control device (100) that controls the operation of (110), and the seedling transport device (110) is provided every other row for half the number of planting rows of the seedling planting section (4). The tip of the extended seedling tank (54) is positioned close to the rear end of the seedling transport device (110) when the seedling tank (53) is raised. The control device (100) moves the seedling tank (53) to one side in the left-right direction to supply seedlings to the even-numbered rows of the seedling planting section (4) by the seedling transport device (110), and moves the seedling tank (53) to the other side in the left-right direction to supply seedlings to the odd-numbered rows of the seedling planting section (4) by the seedling transport device (110). [Effects of the Invention]

[0007] According to one embodiment, the work vehicle can reduce the labor required for supplying seedlings to the seedling tank. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a side view showing a work vehicle according to the first embodiment. [Figure 2] Figure 2 is a front view showing a work vehicle according to the first embodiment. [Figure 3] Figure 3 is a block diagram showing the control system, centered around the control device of the seedling transplanter. [Figure 4] Figure 4 is a rear view showing the seedling transport device, the extended seedling tank, and the seedling tank. [Figure 5] Figure 5 is a side view showing the seedling transport device. [Figure 6] Figure 6 is a front view showing the seedling transport device. [Figure 7] Figure 7 is a plan view showing the seedling transport device. [Figure 8] FIG. 8 is a side view showing a seedling conveying device, an extended seedling tank, and a seedling tank. [Figure 9] FIG. 9 is a view showing the inner width of the seedling conveying device and the inner width of the extended seedling tank. [Figure 10] FIG. 10 is a side view showing a seedling conveying device, an extended seedling tank, and a seedling tank. [Figure 11] FIG. 11 is a rear view showing a situation where the seedling tank is shifted to one side in the left - right direction to supply seedlings. [Figure 12] FIG. 12 is a rear view showing a situation where the seedling tank is shifted to the other side in the left - right direction to supply seedlings. [Figure 13] FIG. 13 is a front view showing the seedling conveying device in a stored state. [Figure 14] FIG. 14 is a front view showing a second seedling conveying device switching from an unfolded state to a stored state. [Figure 15] FIG. 15 is a front view showing a third seedling conveying device switching from an unfolded state to a stored state. [Figure 16] FIG. 16 is a plan view showing a work vehicle according to the second embodiment. [Figure 17] FIG. 17 is a plan view showing a work vehicle according to the second embodiment. [Figure 18] FIG. 18 is a side view showing a work vehicle according to the second embodiment. [Figure 19] FIG. 19 is a side view showing a seedling pick - up plate, a seedling box placement, a seedling conveying device, an extended seedling tank, and a seedling tank. [Figure 20] FIG. 20 is a side view showing a step extending in front of the traveling vehicle body. MODE FOR CARRYING OUT THE INVENTION

[0009] First, referring to FIGS. 1 and 2, an overview of a work vehicle 1 according to an embodiment will be described. FIG. 1 is a side view showing a work vehicle 1 according to the first embodiment. FIG. 2 is a front view showing a work vehicle 1 according to the first embodiment.

[0010] In the following description, the front-rear direction is the traveling direction when the work vehicle 1 is moving straight forward. The front side in the traveling direction is defined as "front", and the rear side as "rear". The traveling direction of the work vehicle 1 is, when moving straight forward, the direction from the driver's seat 41 towards the steering wheel 35 (steering device) (see Fig. 1).

[0011] The left-right direction is the direction that is horizontally orthogonal to the front-rear direction, and the left and right are defined towards the "front" side. That is, when the operator (also referred to as the worker) is seated in the driver's seat 41 and facing forward, the left hand side is "left" and the right hand side is "right".

[0012] The up-down direction is the vertical direction. The front-rear direction, the left-right direction, and the up-down direction are mutually orthogonal. Each direction is defined for the convenience of explanation, and the present invention is not limited by these directions.

[0013] In the embodiment, the work vehicle 1 is described as a riding type seedling transplanter 1 that includes a seedling planting unit 4 as a working device and receives seedlings in a field. As shown in Figs. 1 and 2, the seedling transplanter 1 includes a vertically movable seedling planting unit 4 that plants seedlings in a field via a lifting link mechanism (not shown) on the rear side of the traveling vehicle body 2.

[0014] The main body portion of the fertilizer applicator 5 is arranged on the upper rear part of the traveling vehicle body 2. When the work vehicle 1 is not the seedling transplanter 1, it may include a seeding device that supplies seeds as a working device.

[0015] The traveling vehicle body 2 is a four-wheel drive vehicle including left and right front wheels 10 which are wheels and drive wheels, and rear wheels (not shown). On the front side of the main frame 15 that constitutes the vehicle body skeleton of the traveling vehicle body 2, there are provided a transmission case 13 that transmits driving force to the seedling planting unit 4 etc., and a hydraulic continuously variable transmission 14 that outputs the driving force supplied from the engine 30, that is, the rotation generated by the engine 30, to the transmission case 13.

[0016] The continuously variable transmission 14 is a hydrostatic continuously variable transmission known as an HST (Hydro Static Transmission). The following explanation will describe the case where the continuously variable transmission is an HST 14.

[0017] The transmission case 13 is equipped with a sub-transmission mechanism 16 that switches the driving mode of the vehicle body 2, such as when driving on the road in high speed mode or when planting seedlings in low speed mode. Front wheel final cases (not shown) are provided on the left and right sides of the transmission case 13, and the front wheels 10 are attached to left and right front axles (not shown) that protrude outward from front wheel support parts that can change the steering direction of the left and right front wheel final cases.

[0018] Furthermore, rear wheel gear cases (not shown) are attached to both the left and right sides of a rear frame (not shown) that is provided laterally on the rear side of the main frame 15, and rear wheels are attached to the left and right rear axles (not shown) that protrude outward from the rear wheel gear cases, respectively.

[0019] Furthermore, left and right link support frames 23, which support the lifting link mechanism, are provided projecting upward from the upper part of the rear frame. A pair of left and right lower link arms (not shown) are provided on the lower side of the left and right link support frames 23 and between them. A hydraulically operated lifting cylinder 25 (see Figure 3) is provided between the left and right lower link arms.

[0020] An upper link arm (not shown) is provided above the lifting cylinder 25, forming a lifting link mechanism which is a parallel link mechanism. The left and right lower link arms, each with one end connected to the vehicle body 2, the lifting cylinder 25, and the other end of the upper link arm are mounted on the front of the seedling planting section 4.

[0021] Furthermore, an engine 30 is mounted on the main frame 15. The rotational power of the engine 30 is transmitted to the transmission case 13 via a belt drive system (not shown) and an HST 14. The rotational power transmitted to the transmission case 13 is shifted by a sub-transmission mechanism 16 inside the transmission case 13, and then divided into driving power and externally extracted power.

[0022] Furthermore, the rotational power of the engine 30 is transmitted to a hydraulic pump (not shown). The hydraulic pressure generated by the hydraulic pump is supplied to the HST 14, the power steering mechanism 88 of the steering wheel 35 (see Figure 3), the lifting cylinder 25, and the like.

[0023] External power extracted from the rotational power transmitted to the transmission case 13 is transmitted to a planting clutch case (not shown) located at the rear of the vehicle body 2, and from the planting clutch case to the seedling planting unit 4 via a planting transmission shaft (not shown).

[0024] Meanwhile, the left and right drive shafts 42 are provided at the rear of the transmission case 13. The rotational power from the engine 30 is transmitted to the left and right rear wheel gear cases via the transmission case 13 and the drive shafts 42.

[0025] Furthermore, a side clutch 44 (see Figure 3) for switching power transmission to the left and right drive shafts 42 is positioned upstream of the left and right drive shafts 42 in the transmission direction. As shown in Figure 1, a side clutch pedal (not shown) for operating the left and right side clutches 44 is provided on the front lower part of the driver's seat 41, on one side.

[0026] By depressing the side clutch pedal on the inside of the turn to disengage the side clutch 44, and then operating the steering wheel 35 to turn, the drive rotation of the inner rear wheel can be completely shut off.

[0027] A bonnet 39 is provided on the upper front of the vehicle body 2, with a control panel 38 for operating various parts positioned on top. The control panel 38 is equipped with a monitor 86 (see Figure 3), etc.

[0028] The bonnet 39 is also equipped with a steering wheel 35 for steering the vehicle body 2, a main transmission lever 36 for operating the HST 14 and seedling planting unit 4, and a sub-transmission lever 37 for operating the sub-transmission mechanism 16. When the main transmission lever 36 is operated, the vehicle body 2 can be switched between forward and reverse.

[0029] Furthermore, a front cover 40 that can be opened and closed is provided on the front of the bonnet 39. Inside the front cover 40 are the fuel tank, battery, and an interlocking mechanism that rotates the left and right front wheels 10 and the lower parts of the left and right front wheel final cases in response to the steering of the steering wheel 35. The front wheels 10 are, for example, steering wheels that turn in response to the steering of the steering wheel 35.

[0030] An engine cover 30a is provided behind the bonnet 39 and above the engine 30, covering the top and sides of the engine 30, and a cockpit 41 where the driver sits is provided on top of the engine cover 30a.

[0031] A fertilizer application device 5 is provided behind the cockpit 41 and at the rear end of the main frame 15. The driving force for the fertilizer application device 5 is transmitted by a fertilizer transmission mechanism, which is provided so as to face the fertilizer application device 5 from one side of the left and right rear wheel gear cases.

[0032] On both the left and right sides of the lower part of the engine cover 30a and bonnet 39, a roughly horizontal floor step 33 is formed. The floor step 33 is partially lattice-shaped, so that, for example, if mud from the driver's shoes falls onto the floor step 33, the fallen mud will fall onto the field.

[0033] Furthermore, a rear step (not shown) is connected to the rear of the floor step 33. Preferably, the surface of the rear step is treated with an anti-slip finish, such as having multiple protrusion patterns, to prevent feet from slipping during work.

[0034] Furthermore, a seedling transport device 110 is provided above the vehicle body 2, enabling the transport of seedlings to the extended seedling tank 54.

[0035] Furthermore, a seedling tank 53 for loading seedlings to be planted in the field is attached to the rear end of the lifting link mechanism, along with a sliding mechanism that allows it to slide in the left-right direction. Long seedling partition fences are arranged on the seedling tank 53 at predetermined intervals in the left-right direction. Below the seedling tank 53 is a seedling planting device 55 that scoops up the loaded seedlings and plants them in the field. For example, the seedling tank 53 is configured to reciprocate from side to side in conjunction with the planting operation of the seedling planting device 55. An extension seedling tank 54 is provided above the seedling tank 53, and is configured to extend the area in which the work vehicle 1 loads seedlings upwards.

[0036] The seedling planting device 55 plants the same number of seedlings as the number of planting rows separated by seedling partition fences, i.e., 8 rows simultaneously. Four planting transmission cases 56 are arranged at intervals below the seedling tank 53, and planting rotary tools 57 are attached to both the left and right sides of the planting transmission cases 56, which rotate and pick up seedlings with planting rods 58 to plant in the field.

[0037] The fertilizer application device 5 has a fertilizer hopper 70 in which fertilizer is stored, and this hopper is divided into the same number of sections as the number of planting rows in the seedling planting section 4 (eight sections in the example shown in Figure 2). However, since an eight-section fertilizer hopper 70 is long in the left-right direction, it reduces the convenience of adding and removing fertilizer. Therefore, a so-called side fertilization structure may be used, where sections divided into four sections are arranged on the left and right sides.

[0038] At the bottom of the fertilizer hopper 70, a dispensing device 71 is provided for each row to supply a set amount of fertilizer. Below the dispensing device 71, a ventilation duct 72 is provided in the left-right direction through which the airflow that moves the fertilizer passes. Below the dispensing device 71, a fertilizer hose (not shown) is provided to guide the fertilizer to the vicinity of the seedling planting position in the seedling planting section 4. In addition, a blower 74 is provided at one end of the ventilation duct 72, which is operated by an electric motor 76 to generate the airflow for transporting the fertilizer.

[0039] As shown in Figure 1, below the seedling planting section 4, a center float 62C that makes contact with and slides on the field surface, and two side floats 62L and 62R on each side are provided so as to be rotatable around an axis.

[0040] Furthermore, below the seedling planting section 4, in front of the float 62, a leveling rotor (not shown) is provided to smooth out any unevenness in the field surface. Driving force is transmitted to the leveling rotor from the rear wheel gear cases on the left and right sides via rotor transmission shafts (not shown).

[0041] Furthermore, as shown in Figure 1, line markers 65 (see Figure 2) are provided on both the left and right sides of the seedling planting unit 4. One of these markers touches the field surface, forming a groove that serves as a guide for travel in the next work row (next process). When one side of the line markers 65 touches the ground, the other side moves upward and apart. When the seedling planting unit 4 is raised during a turn, both sides move upward and apart. After the turn, when the seedling planting unit 4 is lowered, one side moves upward and the other side touches the ground.

[0042] Furthermore, as shown in Figure 1, a vertically elongated center mascot 66 is provided at the left-right center of the vehicle body 2 and in front of the bonnet 39. By aligning the center mascot 66 with the grooves formed in the field using the left and right line markers 65, 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 unworked areas.

[0043] Depending on the soil type of the field, the guide lines formed by the left and right line markers 65 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 (not shown) which are positioned in front of the left and right line markers 65. That is, by moving the left and right side markers outward and positioning them above the planted seedlings, it becomes possible to perform planting work in line with the planting of seedlings in the previous work row.

[0044] Furthermore, the seedling transplanter 1 is equipped with a position acquisition device 150 (see Figure 3). The position acquisition device 150 detects the current position and orientation of the seedling transplanter 1. That is, the position acquisition device 150 detects information regarding the position and orientation of the traveling vehicle body 2. The position acquisition device 150 includes, for example, an orientation sensor and positioning means such as GPS (Global Positioning System) or GNSS (Global Navigation Satellite System). The position acquisition device 150 may be composed of multiple devices. The position acquisition device 150 may also include a camera and an ultrasonic sensor, and may acquire the turning position in the field and detect the distance to the turning position.

[0045] Next, the control system of the seedling transplanter 1 will be described with reference to Figure 3. Figure 3 is a block diagram showing the control system of the seedling transplanter 1, centered on the control device 100. The seedling transplanter 1 is capable of controlling each part by electronic control and is equipped with a control device 100 that controls each part.

[0046] The control device 100 is equipped with 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, which are connected to each other and can exchange signals with each other.

[0047] The memory unit stores computer programs and other data that control the seedling transplanter 1. The control device 100 performs its functions by reading the computer programs and other data stored in the memory unit.

[0048] The control device 100 is connected to actuators such as a throttle motor 80, hydraulic control valves 81 and 82, planting clutch operating solenoid 83, side clutch operating solenoid 84, HST motor 85, line drawing marker lifting motor 87, steering motor 95, differential lock switching motor 96, and transport motor 111.

[0049] The throttle motor 80 increases or decreases the rotational speed of the engine 30's output shaft by operating a throttle that adjusts the intake volume of the engine 30. The hydraulic control valve 81 controls the extension and retraction of the lifting cylinder 25. The hydraulic control valve 82 controls the power steering mechanism 88. The power steering mechanism 88 changes the direction of the front wheels 10, which are the steering wheels of the vehicle body 2. The planting clutch operating solenoid 83 operates the planting clutch 27a.

[0050] The side clutch operating solenoid 84 activates the side clutch 44, which switches the power transmission state to the rear wheels (see Figure 1). Note that there are side clutches 44 on each of the left and right rear wheels, and two side clutch operating solenoids 84 are provided, one for each side clutch 44.

[0051] The HST motor 85 changes the tilt angle of the swash plate of the HST14 by changing the rotation angle of the trunnion of the HST14. The steering motor 95 is a motor that drives the handle 35, which is a steering device that adjusts the amount of steering (steering angle) of the front wheels 10 (see Figure 1) when automatic turning control is performed. The steering motor 95 rotates the handle 35. The line marking marker lifting motor 87 lifts and lowers the line marking marker 65.

[0052] The differential lock switching motor 96 is a motor that switches the operation and deactivation of the differential lock mechanism 97 (hereinafter referred to as the differential lock mechanism), which rotates the left and right driving wheels, for example, the left and right front wheels 10, at the same rotational speed. When the differential lock mechanism 97 is engaged, the left and right driving wheels rotate at the same rotational speed.

[0053] The conveying motor 111 drives the conveying belt 112 of the seedling conveying device 110 to transport seedlings to the seedling tank 53.

[0054] The control device 100 is connected to detection devices such as a rotation speed sensor 90, a steering amount sensor 91, and a position acquisition device 150. Two rotation speed sensors 90 are provided, one for each of the left and right rear wheels, and each detects the rotation speed of the left and right rear wheels. The rotation speed sensors 90 may also detect the rotation speed of the left and right front wheels 10.

[0055] The steering amount sensor 91 detects the steering angle of the steering wheel 35, which is part of the steering device. In other words, the steering amount sensor 91 detects the operating position of the steering wheel 35, that is, the amount of steering (steering angle) of the front wheels 10. The steering amount sensor 91 is mounted, for example, on an axis connected to the pitman arm. The steering angle is detected in both the left and right directions, with the value when the steering wheel 35 is in a preset straight-ahead position being used as the reference value (0 degrees). For example, the steering angle is detected in conjunction with the turning direction of the steering wheel 35.

[0056] Furthermore, the control device 100 receives signals as operation signals from the main gear shift lever 36, the sub-gear shift lever 37, the autonomous driving selector switch 46, the seedling planting unit lifting switch 47, and the automatic turning selector switch 48, among others. At least one of these switches may be a button.

[0057] The autonomous driving selector switch 46 is a switch that switches whether or not to perform autonomous driving. Specifically, the autonomous driving selector switch 46 is a switch that switches the driving mode between manual driving mode and autonomous driving mode (automatic driving mode). Manual driving mode is a mode in which the vehicle is driven by the operator's manual operation. Autonomous driving mode is a mode in which the vehicle is driven automatically without the operator's manual operation.

[0058] The seedling planting unit lifting switch 47 is a switch that toggles whether or not to raise or lower the seedling planting unit 4. The seedling planting unit lifting switch 47 can be changed to the "up" and "down" positions.

[0059] When the seedling planting unit lift switch 47 is in the "up" position, the seedling planting unit 4 enters a non-working state where the seedling planting device 55 stops and the seedling planting unit 4 rises to a predetermined non-working position. When the seedling planting unit lift switch 47 is in the "down" position, the seedling planting unit 4 lowers to a predetermined working position (predetermined planting work position) and enters a working state where the seedling planting device 55 operates.

[0060] The automatic turning switch 48 is a switch that toggles whether or not automatic turning is enabled. When the automatic turning switch 48 is set to "ON", the turning assist function is enabled and automatic turning can be performed. When the automatic turning switch 48 is set to "OFF", the turning assist function is disabled and automatic turning cannot be performed. When the automatic turning switch 48 is set to "OFF", automatic turning will not be performed even if the conditions for performing automatic turning are met. Note that when the automatic turning switch 48 is set to "ON", the automatic planting switch 49 is also set to "ON".

[0061] The control device 100 switches the driving mode between manual driving mode and autonomous driving mode in response to the operation of the autonomous driving switch 46, the automatic straight-ahead driving switch 45, and the automatic turning switch 48.

[0062] Furthermore, the control device 100 receives information from the position acquisition device 150 regarding the current position of the vehicle body 2. The control device 100 then executes an autonomous driving mode in which the vehicle body 2 automatically drives and performs tasks.

[0063] Furthermore, the control device 100 receives various information from the remote control device 170 (hereinafter referred to as "remote control"). For example, the control device 100 receives various information from the remote control 170 via a receiver. The receiver is, for example, mounted on a mounting bracket and positioned above the front of the vehicle body 2. Multiple receivers may be provided. The mounting bracket is attached to the vehicle body 2.

[0064] The remote control 170 can remotely operate the seedling transplanter 1. The remote control 170 may also be a terminal device such as a smartphone. The remote control 170 transmits control signals in response to the operator's operations. The remote control 170 is connected to the control device 100 via short-range wireless communication such as Wi-Fi (registered trademark) or BLE (Bluetooth (registered trademark) Low Energy), but is not limited to this, and may be connected via a communication network in addition to or instead of short-range wireless communication.

[0065] Next, the seedling conveying device 110 will be described with reference to Figures 4 to 12. Figure 4 is a rear view showing the seedling conveying device 110, the extension seedling tank 54, and the seedling tank 53. Figure 5 is a side view showing the seedling conveying device 110. Figure 6 is a front view showing the seedling conveying device 110. Figure 7 is a top view showing the seedling conveying device 110. Figure 8 is a side view showing the seedling conveying device 110, the extension seedling tank 54, and the seedling tank 53. Figure 9 shows the inner width L1 of the seedling conveying device 110 and the inner width L2 of the extension seedling tank 54. Figure 10 is a side view showing the seedling conveying device 110, the extension seedling tank 54, and the seedling tank 53. Figure 11 is a rear view showing the seedling tank 53 being moved to one side in the left-right direction to supply seedlings. Figure 12 is a rear view showing the seedling tank 53 being moved to the other side in the left-right direction to supply seedlings. In this embodiment, the case where the seedling planting unit 4 has 8 planting rows is described, but the number of planting rows in the seedling planting unit 4 is not particularly limited. Also, the seedlings are supplied as a seedling mat, which is made up of multiple seedlings gathered together.

[0066] As shown in Figure 4, the seedling transport devices 110 are arranged every other row, with half the number of devices being used for planting rows being placed. For example, if the seedling planting section 4 has 8 planting rows, 4 seedling transport devices 110 are arranged. This allows the system to be composed of half the number of seedling transport devices 110 as planting rows, thus simplifying the seedling transport device 110.

[0067] As shown in Figures 5 to 7, the seedling conveying device 110 has a plurality of conveying motors 111, a plurality of conveying belts 112, and side frames 113. The seedling conveying device 110 is configured such that the plurality of conveying belts 112 are arranged linearly in the front-rear direction, and each conveying motor 111 drives each conveying belt 112, thereby conveying the seedling mat placed on the conveying belts 112 toward the seedling tank 53 at the rear. The side frames 113 are provided on both the left and right sides of the seedling conveying device 110, and the conveying motors 111 are attached to them.

[0068] As shown in Figure 8, the tip of the extended seedling tank 54 is configured to rise when the seedling planting section 4 is raised, bringing it closer to the rear end of the seedling conveying device 110. For example, when the seedling planting section 4 is raised, the tip of the extended seedling tank 54 is configured to come within approximately 10 mm of the rear end of the belt of the seedling conveying device 110. This prevents the seedling mat from sagging and tearing, and allows seedlings to be supplied to the seedling tank 53.

[0069] The extension seedling tank 54 may have a vertical tip and a gently curved radius connecting to the seedling tank 53. Alternatively, the extension seedling tank 54 may be positioned so that the upper surface (rear surface) of its tip aligns with the tangent T of the rear end of the belt. This ensures that when the extension seedling tank 54 receives a seedling mat, the mat slides into the seedling tank 53 without getting caught on the extension seedling tank 54.

[0070] As shown in Figure 9, the extension seedling tank 54 is provided with guides 54a on both sides in the left-right direction to assist in the sliding of seedling mats from the conveyor belt 112 into the seedling tank 53. The guides 54a may have a shape that protrudes in the front-rear direction. In addition, in the area where the seedling conveying device 110 and the extension seedling tank 54 are in close proximity, the inner width L2 of the extension seedling tank 54 is wider than the inner width L1 of the seedling conveying device 110. The inner width L1 of the seedling conveying device 110 is the distance between the inner surfaces of the side frames 113 on both sides in the left-right direction. The inner width L2 of the extension seedling tank 54 is the distance between the inner surfaces of the guides 54a on both sides in the left-right direction. As a result, by regulating the left-right direction when loading seedling mats, the seedling mats slide smoothly into the seedling tank 53, allowing for smooth loading of seedling mats from the seedling conveying device 110 into the seedling tank 53.

[0071] As shown in Figure 10, the joint between the extension seedling tank 54 and the seedling tank 53 may be configured with a pivot shaft 54b, and the extension seedling tank 54 may be made to stand upright in the upward direction by a spring. Alternatively, projections 54c may be provided on both the left and right sides of the tip of the extension seedling tank 54, so that when the seedling tank 53 is raised, these projections 54c come into contact with the lower surface of the side frame 113 of the seedling conveying device 110. This prevents damage to the tip of the extension seedling tank 54 even if it comes into contact with the seedling conveying device 110 due to the rolling of the seedling planting unit 4. In addition, the positional relationship between the conveying belt 112 of the seedling conveying device 110 and the tip of the extension seedling tank 54 can be kept constant, thus stabilizing the supply of seedling mats.

[0072] As shown in Figures 11 and 12, when the seedling planting unit 4 has 8 planting rows, the control device 100 moves the seedling tank 53 to the leftmost position and supplies seedling mats to rows 2, 4, 6, and 8 of the seedling tank 53 (see arrow A). The control device 100 also moves the seedling tank 53 to the rightmost position and supplies seedling mats to rows 1, 3, 5, and 7 of the seedling tank 53 (see arrow B). In other words, the control device 100 moves the seedling tank 53 to one side in the left-right direction and supplies seedlings to the even-numbered rows of the seedling planting unit 4 by the seedling transport device 110, and moves the seedling tank 53 to the other side in the left-right direction and supplies seedlings to the odd-numbered rows of the seedling planting unit 4 by the seedling transport device 110. This allows the seedling transport device 110 to be simplified because it can be configured with half the number of rows in the seedling planting unit 4.

[0073] The control device 100 operates the seedling transport device 110 with the seedling planting unit 4 raised while the vehicle body 2 is turning or stopped, supplying seedling mats to the seedling tank 53. The control device 100 stores the lateral position (hereinafter referred to as the lateral position) of the seedling tank 53 when the planting rod 58 last rotated before the seedling planting unit 4 was raised. This allows the control device 100 to move the seedling tank 53 to its furthest right or furthest left position for supplying seedlings to the seedling tank 53, and then return it to the lateral position of the seedling tank 53 just before the seedling planting unit 4 was raised. Therefore, the planting rod 58 can take seedlings from the position of the seedling mat just before the seedling planting unit 4 was raised and plant them in the field.

[0074] Furthermore, in order for the control device 100 to recognize the lateral position of the seedling tank 53, a sensor is provided to detect the number of rotations of the planting rod 58. Specifically, the control device 100 counts the number of rotations of the planting rod 58 using the sensor after a switch for detecting the lateral position of the seedling tank 53, which is a conventional technology, is pressed. This allows the control device 100 to remember the lateral position of the seedling tank 53 at the time the planting rod 58 last rotated before the seedling planting unit 4 was raised. In addition, after raising the seedling tank 53 and moving its lateral position to the far right or far left to supply seedlings, the control device 100 can adjust the lateral position of the seedling tank 53 to the most recent continuous position when planting is resumed.

[0075] Furthermore, the seedling transport device 110 may be positioned with a downward-sloping orientation towards the front. This makes it easier for the operator to supply the seedlings.

[0076] Next, the storage of the seedling conveying device 110 will be explained with reference to Figures 13 to 15. Figure 13 is a front view showing the seedling conveying device 110 in the stored state. Figure 14 is a front view showing the second seedling conveying device 110b switching from the deployed state to the stored state. Figure 15 is a front view showing the third seedling conveying device 110c switching from the deployed state to the stored state.

[0077] Figure 14(a) is a front view showing the second seedling conveying device 110b in its deployed state. Figure 14(b) is a front view showing the second seedling conveying device 110b in the process of switching from the deployed state to the stored state. Figure 14(c) is a front view showing the second seedling conveying device 110b in the stored state. Figure 15(a) is a front view showing the third seedling conveying device 110c in its deployed state. Figure 15(b) is a front view showing the third seedling conveying device 110c in the process of switching from the deployed state to the stored state. Figure 15(c) is a front view showing the third seedling conveying device 110c in the stored state.

[0078] As shown in Figure 13, when the number of planting rows in the seedling planting section 4 is 8, the configuration is such that two seedling transport devices 110 in the center in the left-right direction can be accommodated. Specifically, the seedling transport device 110 has a first seedling transport device 110a, a second seedling transport device 110b, a third seedling transport device 110c, and a fourth seedling transport device 110d in order from one side to the other in the left-right direction (see Figure 2). As shown in Figure 14, the seedling transplanter 1 is provided with a first frame 116 fixed to the traveling vehicle body 2. The first frame 116 has a first support point 114a located at one end of the first frame 116 and a second support point 114b located at the other end of the first frame 116. Furthermore, the first frame 116 is connected to both ends of the first frame 116, respectively, to a first arm 115a that rotates around the front-rear direction as the axis of rotation at a first pivot point 114a, and a second arm 115b that rotates around the front-rear direction as the axis of rotation at a second pivot point 114b.

[0079] The second seedling transport device 110b is connected to the end of the first arm 115a and the end of the second arm 115b, respectively, on the side opposite to the first frame 116. The second seedling transport device 110b can be switched between an unfolded state, where it is located to the side of the first seedling transport device 110a (for example, on the right side), and a retracted state, where it is located above the first seedling transport device 110a, by the rotation of the first arm 115a and the second arm 115b (for example, by rotating to the left). This allows the second seedling transport device 110b to be retracted without the seedling mat falling off, even when it is loaded with seedling mats.

[0080] As shown in Figure 15, the second frame 118 has a third pivot point 114c located at one end of the second frame 118 and a fourth pivot point 114d located at the other end of the second frame 118. Furthermore, the second frame 118 has a third arm 115c that rotates around the front-rear direction as the axis of rotation at the third pivot point 114c, and a fourth arm 115d that rotates around the front-rear direction as the axis of rotation at the fourth pivot point 114d, which are connected to both ends of the second frame 118.

[0081] The third seedling transport device 110c is connected to the end of the third arm 115c and the end of the fourth arm 115d, respectively, on the opposite side of the second frame 118. The third seedling transport device 110c can be switched between an extended state, where it is located to the side (for example, on the left side) of the fourth seedling transport device 110d, and a retracted state, where it is located above the fourth seedling transport device 110d, by the rotation of the third arm 115c and the fourth arm 115d (for example, by rotating to the right). This allows the third seedling transport device 110c to be retracted without the seedling mat falling off, even when a seedling mat is loaded onto it. Furthermore, because the two seedling transport devices 110 are moved to the center of the vehicle body 2, the second seedling transport device 110b and the third seedling transport device 110c do not obstruct the operator when they are riding on the vehicle.

[0082] The second seedling transport device 110b and the third seedling transport device 110c are deployed (in use) to supply seedlings to the seedling tank 53 during planting operations. When an operator is riding in the work vehicle 1, such as when moving between fields other than during planting operations, the second seedling transport device 110b and the third seedling transport device 110c are used in their stored state. This ensures that when the seedling transport device 110 is equipped on a remotely monitored seedling transplanter 1, the second seedling transport device 110b and the third seedling transport device 110c do not obstruct the operator's riding in the work vehicle 1 when moving between fields other than during planting operations.

[0083] Next, a second embodiment of the work vehicle 1 will be described with reference to Figures 16 to 20. Figures 16 and 17 are plan views showing the work vehicle 1 according to the second embodiment. Figure 18 is a side view showing the work vehicle 1 according to the second embodiment. Figure 19 is a side view showing the seedling tray 122, seedling tray holder 123, seedling transport device 120, extended seedling tank 54, and seedling tank 53. Figure 20 is a side view showing the step 121 extending forward of the vehicle body 2.

[0084] Figure 19(a) is a side view showing the seedling transport device 120, the extended seedling tank 54, and the seedling tank 53. Figure 19(b) is an enlarged side view of the vicinity of the front end of the seedling transport device 120. Figure 19(c) is an enlarged side view of the vicinity of the rear end of the seedling transport device 120. Furthermore, in the following, components common to the first embodiment described above are denoted by the same reference numerals and their descriptions are omitted.

[0085] As shown in Figure 16, the work vehicle 1 is equipped with a seedling transport device 120 configured on rails that transports seedlings from the front of the vehicle body 2 to the seedling tank 53. The seedling transport device 120 is arranged in parallel in a number equal to half the number of planting rows and moves left and right relative to the seedling tank 53, supplying seedling mats to the seedling tank 53 every other row. In seedling supply, the work vehicle 1 is equipped with detection means (for example, sensing switches SW6, SW7) that detects when the seedling tank 53 has been moved to one end in the left-right direction, and when the seedling mats have been supplied every other row, and when the supply is complete. When the control device 100 detects that the supply of half of the seedlings has been completed by the detection means, it automatically moves the seedling tank 53 to the opposite end with the planting clutch 27a disengaged and continues supplying seedlings. This configuration reduces the burden of seedling supply.

[0086] The work vehicle 1 is equipped with a guide device 128 (see Figure 19(c)) at the rear end of the seedling transport device 120 for transferring seedling mats to the seedling tank 53. With this configuration, seedling mats made of soft soil can be transported to the seedling tank 53 without collapsing.

[0087] The guide device 128 is configured to bend towards the seedling tank 53 due to the load of the seedling mat, and the bent guide device 128 is configured to come into contact with the extended seedling tank 54 (see arrow G in Figure 19(c)). With this configuration, the guide device 128 only guides the seedlings to the seedling tank 53 during seedling transport, so as not to obstruct the lateral movement of the seedling tank 53 during operation.

[0088] The guide device 128 is set so that when it is not operating, its rear end is higher than the position where the seedling mat is being transported. This configuration prevents the seedling mat from falling even if it is placed on the guide device 128, as long as the guide device 128 is not operating.

[0089] The guide device 128 is configured to be long enough so that when seedlings are placed on the guide device 128, the seedling tank 53 descends to a certain height, causing the seedling mat to reach the seedling tank 53. This ensures that the seedling mat falls reliably towards the seedling tank 53 while the guide device 128 is in operation.

[0090] The seedling transport device 120 may be configured to be movable in the left-right direction (see arrow C). The amount of left-right movement of the seedling transport devices 120b and 120c on the inside of the vehicle body 2 and the seedling transport devices 120a and 120d on the outside of the vehicle body 2 may be different, and the amount of lateral movement of the seedling transport devices 120b and 120c on the inside of the vehicle body 2 may be greater than the amount of lateral movement of the seedling transport devices 120a and 120d on the outside of the vehicle body 2, so that the vehicle body 2 can be moved outwards in the left-right direction. With this configuration, as shown in Figure 17, the seedling transport devices 120b and 120c on the inside of the vehicle body 2 can be moved by a larger amount so as not to interfere with the operator when boarding.

[0091] The seedling transport device 120 has multiple rails in the front-rear direction (the first seedling supply rail, second seedling supply rail, third seedling supply rail, and fourth seedling supply rail, which will be described later). As shown in Figure 18, the foremost rail (first seedling supply rail) can be stored in the front-rear direction (see arrow E), and when stored, it is positioned behind the foremost end of the vehicle body 2 (see operating position P1 and stored position P2). Furthermore, even when the foremost rail is stored, it is positioned so that the seedling transport surface faces upward. This configuration allows for a compact arrangement of rails during transport and storage. In addition, the foremost rail can be stored even if a seedling mat is placed on it.

[0092] The seedling transport device 120 is installed at a lower position than the GNSS sensor 117 even when stored. With this configuration, the seedling transplanter 1 can operate automatically even when stored.

[0093] As shown in Figure 19(a), the seedling tray holder 123 is positioned in front of the seedling transport device 120 and can be stored in the front-to-back direction (see arrow F). With this configuration, the seedling mat S, which has been unloaded from a transport means such as a light truck, can be placed on the seedling transplanter 1 without being placed on the ground, and the seedling mat S can be removed. In addition, the seedling tray holder 123 does not get in the way during storage or planting work.

[0094] As shown in Figure 19(b), the work vehicle 1 is equipped with a stopper 126 to prevent the seedling tray 122 from interfering with the conveyor belt 124 when seedlings are removed from the seedling trays using the seedling tray 122. With this configuration, the stopper 126 can receive the force applied by the seedling tray 122 when seedlings are removed from the seedling trays using the seedling tray 122.

[0095] The work vehicle 1 has a sensing switch SW1 positioned in front of the stopper 126. When a seedling tray (seedling mat S) is placed, the sensing switch SW1 detects it, allowing the drive of the conveyor belt 124 to start at the right time.

[0096] As shown in Figure 19(a), the seedling transport device 120 has four seedling supply rails in the front-rear direction. The first seedling supply rail is equipped with a transport motor M1 and a sensing switch SW2, the second seedling supply rail with a transport motor M2 and a sensing switch SW3, the third seedling supply rail with a transport motor M3 and a sensing switch SW4, and the fourth seedling supply rail with a transport motor M4 and a sensing switch SW5. The seedling transport device 120 has the sensing switch SW2 positioned after the sensing switch SW1. The sensing switch SW2 is positioned behind the leading edge of the first transport belt 124 and in front of the next transport belt. When there are three or more sensing switches (for example, sensing switches SW1 to SW7), the sensing switches are arranged at equal intervals. The position of the sensing switches makes it easier to detect the movement of one seedling mat S, and the device can be configured to transport the next seedling mat S to the seedling tank 53 side when one seedling mat S has been transported.

[0097] The conveyor belts are spaced at intervals longer than the length of one seedling mat S. This configuration ensures that each seedling mat S is conveyed individually, thus avoiding the problem of partially stacking the mats.

[0098] Furthermore, the conveyor belt is configured to be long enough so that when one seedling mat S passes through, seedlings are placed on both the destination belt and the source belt. This improves the conveying capacity of the seedling mat S. In addition, by installing guides between the conveyor belts, sagging of the conveyor belts due to their length can be prevented.

[0099] The conveyor belt positioned closest to the seedling tank 53 is configured such that when the seedling mat S leaves the conveyor belt, the seedling mat S rests on the guide device 128. This ensures that the seedling mats S are transported reliably without overlapping.

[0100] In the work vehicle 1, the sensing switch SW6 is positioned above the position where one seedling mat S is placed in the seedling tank 53, and a sensing switch SW7 is also positioned below the seedling tank 53. This configuration ensures that the seedling mats S are supplied reliably without overlapping.

[0101] As described above, the work vehicle 1 is equipped with a sensing switch SW1 in front of the stopper 126 (behind the seedling tray holder 123 (on the belt side)). With this configuration, the detection of the seedling mat S by the sensing switch SW1 can be used as a trigger to start the operation of the conveyor belt 124.

[0102] If the sensing switch SW1 of the seedling tray holder 123 is pressed, and the sensing switches SW2-7 located behind the sensing switch SW1 of the seedling tray holder 123 are not pressed, the control device 100 activates the drive motor for the conveyor belt behind the seedling tray holder 123. This configuration allows the conveyor belt 124 to transport the seedling mat S only when there is no seedling mat S behind it.

[0103] If the sensing switch on the seedling supply rail is not pressed, and the sensing switch in front of it is pressed, the control device 100 drives the drive motor of the conveyor belt whose front end is closest to the unpressed sensing switch. At the same time, the control device 100 drives the drive motor of the conveyor belt in front of the said conveyor belt. After this operation, if the sensing switch on the seedling tank 53 side that was not pressed is pressed, the control device has a mechanism to stop the driven conveyor belt. With this configuration, the seedling mat S can be conveyed toward an area where there is no seedling mat S, and when the seedling mat S is conveyed toward an area where there is no seedling mat S, the driven conveyor belt can be stopped.

[0104] The control device 100 is equipped with a control mechanism that stops the conveyor belt after a set time has elapsed since the sensing switch was pressed, and the set time can be changed for each position of the seedling conveying device 120. This allows the seedling mat S to be conveyed to the desired position even if the sensing switch that detects the arrival of the seedling mat S is not located at the edge of the seedling mat S.

[0105] The control device 100 operates the drive motor of the seedling conveyor belt closest to the seedling tank 53 if the sensing switches SW6 and SW7 on the seedling tank 53 side are not pressed, the seedling planting unit 4 is stopped, the seedling tank 53 is in a predetermined position, the height of the seedling planting unit 4 is at a predetermined height, and the position of the seedling supply rail is in a predetermined position. The control device 100 then operates the drive motor until the sensing switch SW6 on the upper side of the seedling tank 53 is pressed. This configuration ensures that seedlings are reliably supplied to the seedling tank 53.

[0106] The control device 100 may move the seedling transport device 120 in the left-right direction using an actuator. This configuration allows the row in which the seedling mat S is supplied to be changed.

[0107] The work vehicle 1 is equipped with a notification means that notifies whether or not the sensing switch SW6 on the top of the seedling tank 53 is pressed. With this configuration, the worker can confirm whether or not seedling supply is needed.

[0108] The work vehicle 1 may be equipped with a notification lamp as a means of notification. The notification lamp may be a lamp visible from the front of the traveling vehicle body 2 or a display on the monitor 86. With this configuration, since seedlings are supplied from the front, it becomes easier for the worker to notice the notification.

[0109] The control device 100 is configured to allow selection so that the conveyor belt closest to the seedling tank 53 does not operate even if the sensing switch SW6 on the top of the seedling tank 53 is not pressed. The control device 100 controls whether or not the conveyor belt closest to the seedling tank 53 operates, which can be switched via the selection screen or switch on the monitor 86. With this configuration, it is possible to choose not to add seedling mats S when there is no need to add them, such as near the end of planting.

[0110] If a row is designated not to receive seedling mat S, the control device 100 switches to a control mode that supplies seedlings to the remaining rows of the other rows when the sensing switch SW5 on top of the seedling tank 53 of the other rows is pressed a predetermined number of times.

[0111] The last unit (seedling supply rail) of the seedling transport device 120, roughly the size of one seedling mat S, may be independent, and the control device 100 may be configured to detect whether the seedling tank 53 is to the right or left when supplying seedlings, and to move the above unit to a predetermined position in the left or right direction to transport the seedling mat S. This makes it possible to configure the seedling transport device 120 without moving the entire device.

[0112] In the configuration where the seedling tank 53 moves in the left-right direction, the control device 100 controls the supply of seedling mats S to the seedling supply rails that are moving in the left-right direction, after detecting that the seedling supply rail in front of the seedling tank 53 has returned to a predetermined position. With this configuration, seedling mats S will not be supplied unless the seedling supply rails are aligned in a single row.

[0113] The transport motors of the seedling transport devices 120a and 120d on the outside of the vehicle body 2 are located on the outside of the vehicle body 2 in the left-right direction. The transport motors of the seedling transport devices 120b and 120c on the outside of the vehicle body 2 are located on the inside of the vehicle body 2 in the left-right direction. This configuration prevents the transport motors from interfering with storage during storage.

[0114] As shown in Figure 20, the work vehicle 1 is equipped with a step 121 that extends forward of the vehicle body 2 beyond the conveyor belt of the seedling conveying device 120. The step 121 can be rotated in the front-rear direction and retracted (see arrow D). This configuration makes it easy for the worker to stand on the step 121 and place the seedling mat S when supplying seedlings. Also, when not supplying seedlings, the step 121 can be retracted so that it does not get in the way.

[0115] The seedling transport device 120 consists of units, each approximately the length of one seedling transport rail, which can be freely combined. This configuration allows the units to be freely arranged, enabling the transport direction of the seedling transport device 120 to be arbitrarily set.

[0116] 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]

[0117] 1. Seedling transplanter (work vehicle) 2. Running vehicle 4 Seedling planting department 53 Seedling Tank 54 Extended seedling tank 54a Guide 54b Rotary shaft 58 Studded rod 100 Control device 110 Seedling transport device 110a First seedling transport device 110b Second seedling transport device 110c Third seedling transport device 110d 4th seedling transport device 114a 1st fulcrum 114b Second fulcrum 114c 3rd fulcrum 114d 4th fulcrum 115a First Arm 115b Second Arm 115c Third Arm 115d 4th Arm 116 Frame 1 118 Frame 2 120 Seedling transport device 120a Seedling conveying device 120b Seedling transport device 120c Seedling Conveyor 120d Seedling transport device L1 inner width L2 inner width

Claims

1. A vehicle traveling through a field, A seedling tank is provided at the rear of the vehicle body, on which seedlings are loaded, An extension seedling tank is provided on top of the seedling tank, A seedling planting unit that plants seedlings taken from the seedlings loaded in the seedling tank into the field, A seedling conveying device is provided above the vehicle body and conveys seedlings to the extended seedling tank, The system includes a control device for controlling the operation of the seedling tank, the seedling planting unit, and the seedling transport device, The seedling transport device is provided with half the number of planting rows in the seedling planting section, with every other row being provided. The tip of the extended seedling tank approaches the rear end of the seedling transport device when the seedling tank is raised. The control device is The seedling tank is moved to one side in the left-right direction, and seedlings are supplied to the even-numbered rows of the seedling planting section by the seedling transport device. A work vehicle that moves the seedling tank to the other side in the left-right direction and supplies seedlings to the odd-numbered rows of the seedling planting section using the seedling transport device.

2. The control device is While the vehicle body is turning or stopped, the seedling transport device is operated with the seedling planting section raised to supply seedlings to the seedling tank. The work vehicle according to claim 1, which stores the left-right position of the seedling tank at the last time the planting rod of the seedling planting unit rotates before the seedling planting unit is raised.

3. Guides are provided on the sides of the extended seedling tank to assist seedlings from the seedling transport device in sliding into the seedling tank. The work vehicle according to claim 1, wherein, in the portion where the seedling transport device and the extension seedling tank are in close proximity, the inner width of the extension seedling tank is wider than the inner width of the seedling transport device.

4. If the number of planting rows in the seedling planting section is 8, The seedling conveying device has a first seedling conveying device, a second seedling conveying device, a third seedling conveying device, and a fourth seedling conveying device arranged in order from one side to the other in the left-right direction. The system comprises a first frame and a second frame fixed to the vehicle body, The first frame has a first support point located at one end of the first frame and a second support point located at the other end of the first frame, and the second frame has a third support point located at one end of the second frame and a fourth support point located at the other end of the second frame. The device comprises a first arm that rotates around the front-rear direction as the axis of rotation at the first pivot point, a second arm that rotates around the front-rear direction as the axis of rotation at the second pivot point, a third arm that rotates around the front-rear direction as the axis of rotation at the third pivot point, and a fourth arm that rotates around the front-rear direction as the axis of rotation at the fourth pivot point. The second seedling transport device is connected to the end of the first arm and the end of the second arm on the side opposite to the first frame, respectively, and the third seedling transport device is connected to the end of the third arm and the end of the fourth arm on the side opposite to the second frame, respectively. The second seedling transport device can be switched between an extended state, where it is located to the side of the first seedling transport device, and a retracted state, where it is located above the first seedling transport device, by the rotation of the first and second arms. The third seedling transport device can be switched between an extended state, where it is positioned to the side of the fourth seedling transport device, and a retracted state, where it is positioned above the fourth seedling transport device, by the rotation of the third and fourth arms. During planting, the seedling transport device in its deployed state supplies seedlings to the seedling tank. The work vehicle according to claim 1, wherein the seedling transport device is used in a stored state when the vehicle is being driven, other than during planting work.

Images