Rice transplanter

Abstract

To accurately control a planting timing.SOLUTION: A rice transplanter includes: a PTO shaft 27 for transmitting power as rotation power; a seedling table on which matted seedlings are placed, which is fed longitudinally and transversely by the power transmitted through the PTO shaft 27; a seedling planting mechanism 16 for taking out the seedlings from the matted seedlings and planting them in a farm field; a rotation amount sensor 31 for measuring a rotation amount 43 of the PTO shaft 27; an initialization timing acquisition part 37 for acquiring a start timing for the rotation amount sensor 31 to start the measurement of the rotation amount 43; and a controller 34 for controlling the seedling planting mechanism 16 on the basis of the rotation amount 43 measured by the rotation amount sensor 31 from the start timing acquired by the initialization timing acquisition part 37.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a rice transplanter for planting seedlings in a field. [Background technology]

[0002] As disclosed in Patent Document 1, the rice transplanter is equipped with a seedling planting mechanism that removes seedlings from a seedling carrier and plants them in a field. The seedling planting mechanism is controlled in synchronization with the vehicle speed, and the planting timing is also controlled to adjust the spacing between plants. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-170316 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a demand for rice transplanters to control the planting timing with greater precision. Therefore, an object of the present invention is to control the planting timing with greater precision. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, a rice transplanter according to one embodiment of the present invention comprises a PTO shaft that transmits power as rotational power, a seedling carrier on which mat-shaped seedlings are placed and which is fed vertically and horizontally by the power transmitted via the PTO shaft, a seedling planting mechanism that removes the seedlings from the mat-shaped seedlings and plants them in a field, a rotation amount sensor that measures the amount of rotation of the PTO shaft, an initialization time acquisition unit that acquires the start time at which the rotation amount sensor begins measuring the amount of rotation, and a controller that controls the seedling planting mechanism based on the amount of rotation measured by the rotation amount sensor from the start time acquired by the initialization time acquisition unit.

[0006] With this configuration, the rice transplanter can easily control the seedling planting mechanism based on the rotation amount of the PTO shaft. Furthermore, by measuring the rotation amount based on the specific start time acquired by the initialization time acquisition unit, the rotation amount can be measured with high precision in small increments, allowing for accurate control of the planting mechanism. As a result, planting timing can be controlled with high precision.

[0007] The rotation amount sensor may also have a plurality of markers arranged along the periphery of the PTO shaft and a measuring instrument that measures the number of the markers that pass through a fixed point around the PTO shaft, and may measure the number of the markers measured by the measuring instrument as the amount of rotation.

[0008] This configuration allows the amount of rotation of the PTO shaft to be measured with an accuracy that divides one rotation by the number of markers. As a result, the seedling planting mechanism can be precisely controlled, allowing for more accurate control of planting timing.

[0009] The markings may also be protrusions.

[0010] With this configuration, the amount of rotation can be easily measured, and the planting timing can be easily and accurately controlled.

[0011] The seedling carrier may also be provided with an edge-pushing switch that detects that the seedling carrier has been moved laterally to at least one of the left and right ends, and the initialization time acquisition unit may acquire the time when the edge-pushing switch detects that the seedling carrier has been moved laterally to the end as the start time, and the controller may control the seedling planting mechanism based on the amount of rotation measured after the edge-pushing switch detects that the seedling carrier has been moved laterally to the end.

[0012] This configuration allows the initialization timing acquisition unit to easily acquire the start timing. Furthermore, the seedling carrier is fed horizontally and vertically, allowing the seedlings to be removed and planted in order, starting from the mat-like seedlings. Vertical feeding also occurs when the seedling carrier reaches the left and right ends. Therefore, it is appropriate for the timing of seedling planting to be related to the timing when the seedling carrier reaches the left and right ends. With this configuration, the amount of rotation is measured based on the timing when the seedling carrier reaches the left and right ends, and the seedling planting mechanism is controlled based on this amount of rotation, allowing for more accurate control of the planting timing.

[0013] In addition, the initialization timing acquisition unit may have an initial identification unit provided on the PTO shaft and a detector that detects the initial identification unit when it moves to a predetermined position as the PTO shaft rotates, and acquires the time when the initial identification unit is detected as the start timing, and the controller may control the seedling planting mechanism based on the amount of rotation measured after the detector detects the initial identification unit.

[0014] This configuration allows the initialization time acquisition unit to easily acquire the start time. The amount of rotation is then measured based on the acquired start time, and the seedling planting mechanism is controlled based on this amount of rotation, allowing for accurate control of planting timing.

[0015] The seedling planting mechanism may also have a pair of rotary planting arms that alternately remove the seedlings from the mat of seedlings and plant them in the field, and the controller may control the seedling planting mechanism so that the planting arms plant the seedlings at each predetermined rotation amount.

[0016] The seedlings to be planted in the field are removed from the seedling carrier as the planting arm rotates and transported to the field. With this configuration, the planting arm is controlled based on the amount of rotation, allowing for precise control of planting timing. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a left side view illustrating the overall configuration of a rice transplanter. [Figure 2] FIG. 10 is a schematic diagram illustrating a configuration for transmitting power to the seedling planting device. [Figure 3] FIG. 2 is a diagram illustrating the configuration of a rotation amount sensor; [Figure 4] FIG. 10 is a diagram illustrating a configuration for controlling a seedling planting mechanism. [Figure 5] FIG. 10 is a diagram illustrating a flow for controlling the seedling planting mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0018] The rice transplanter of the present invention will be described below with reference to the drawings. In the following description, with respect to the traveling body (body) of the rice transplanter, the direction of arrow F shown in Figure 1 will be referred to as the "forward body," the direction of arrow B as the "rearward body," the direction of arrow U as the "upward body," the direction of arrow D as the "downward body," the direction toward the front of the page as the "leftward body," and the direction toward the back of the page as the "rightward body."

[0019] [Overall configuration of the rice transplanter] First, the overall configuration of the rice transplanter will be described using Figure 1.

[0020] The rice transplanter is equipped with a traveling machine body on which a pair of left and right front wheels 1 (traveling devices) are steerable and drivable, and a pair of left and right rear wheels 2 (traveling devices) are drivable. An engine 3 is disposed at the front of the traveling machine body. At the rear of the traveling machine body, a driver's seat 5, a steering wheel 6 for steering the front wheels 1, and a ride-on driver's section 7 having a fixed or detachable information terminal 4 are formed. The information terminal 4 displays (announces) various information to notify (output) the operator (driver / worker), and also accepts input of various information.

[0021] A seedling planting device 10 is supported at the rear of the machine frame 8 of the traveling machine body via a link mechanism 9. The link mechanism 9 is supported on the machine frame 8 in a state in which it can swing up and down relative to the machine frame 8. The seedling planting device 10 is raised and lowered between a lowered working state and an raised non-working state by the up and down swing of the link mechanism 9. A fertilizer applicator 11 is provided at the rear of the traveling machine body to supply powdered fertilizer to the seedlings planted by the seedling planting device 10.

[0022] As an example, the seedling planting device 10 is configured as an eight-row planting type. The eight-row planting type seedling planting device 10 includes four planting transmission cases 14, a total of eight seedling planting mechanisms 16 provided on both sides of the rear of each planting transmission case 14, and a seedling carrier 17. The seedling carrier 17 is moved back and forth (laterally fed) left and right in conjunction with the seedling planting movement of the seedling planting mechanisms 16, supplying mat-shaped seedlings placed on the seedling carrier 17 to each seedling planting mechanism 16. When the seedling carrier 17 reaches the end of the horizontal feed, it vertically feeds the mat-shaped seedlings and supplies them to the seedling planting mechanisms 16. Note that this seedling planting device 10 can be changed to a two-row, four-row, six-row, or other type of planting by controlling the individual row clutches (not shown).

[0023] The seedling planting mechanism 16 is driven by power transmitted from the engine 3 to the planting transmission case 14. The seedling planting mechanism 16 is equipped with a pair of rotary planting arms 16B. As the planting arms 16B are driven to rotate, the planting arms 16B alternately pick up seedlings for planting from a mat of seedlings placed on the seedling carrier 17, lower the picked seedlings for planting into the field, transport them to the field, and once planting is complete, return them to the seedling carrier 17 to perform the seedling planting movement.

[0024] The seedling carrier 17 is equipped with a push-button switch 18 on at least one of the left and right ends. The push-button switch 18 detects that the seedling carrier 17 has been fed laterally to the end where the push-button switch 18 is provided and outputs a push-button signal. Specifically, when the seedling carrier 17 is fed laterally to the end where the push-button switch 18 is provided, the push-button switch 18 comes into contact with the seedling carrier 17 and turns on, detecting that the seedling carrier 17 has been fed laterally to the end. Thereafter, when the seedling carrier 17 is fed vertically and starts to be fed laterally in the opposite direction, the push-button switch 18 turns off.

[0025] The seedling carrier 17 is also provided with a seedling quantity sensor 19 that detects the amount of seedlings used that are loaded on the seedling carrier 17. The seedling carrier 17 is divided into eight sections in the width direction (left and right direction of the machine body) to correspond to eight rows of planting, and a mat-shaped seedling is placed in each of the eight divided areas. Furthermore, one or more mat-shaped seedlings are placed vertically (front and rear and up and down directions of the machine body) in each of the eight divided areas.

[0026] The seedling quantity sensor 19 is a sensor that detects whether or not a mat of seedlings is present on the seedling tray 17. When the seedling quantity sensor 19 no longer detects the presence of a mat of seedlings, it can detect that the amount of seedlings placed on the seedling tray 17 is less than a predetermined amount.

[0027] The traveling vehicle is equipped with a positioning unit 12. The positioning unit 12 outputs positioning data for calculating the position and orientation of the traveling vehicle. The positioning unit 12 includes a satellite positioning module that receives radio waves (satellite signals) from satellites of global navigation satellite systems (GNSS such as GPS, GLONASS, Galileo, Michibiki, and BeiDou satellite navigation system), and an inertial measurement module that detects the tilt and acceleration of the three axes of the traveling vehicle.

[0028] [Power transmission configuration] Next, the configuration for transmitting power from the engine 3 to the seedling planting device 10 will be described using FIG. 2 while referring to FIG.

[0029] The power output from the engine 3 is input to a transmission case 21. The transmission case 21 includes a hydrostatic continuously variable transmission 22 (HST: Hydro Static Transmission), an auxiliary transmission 24, and an inter-section transmission 25.

[0030] The continuously variable transmission 22 changes the speed of the power (rotational power) output from the engine 3 in response to an operation performed on a main transmission lever (not shown) or the like provided on the driving unit 7, and outputs the power. The auxiliary transmission 24 changes the speed of the power output from the continuously variable transmission 22 in response to an operation performed on an auxiliary transmission lever (not shown) or the like provided on the driving unit 7, and outputs the power to the front wheels 1 and the rear wheels 2. The row spacing transmission 25 changes the speed of the power output from the continuously variable transmission 22 in response to an operation performed on a row spacing transmission lever (not shown), and outputs the power. By changing the speed of the power output from the continuously variable transmission 22 by the row spacing transmission 25, the row spacing during seedling planting work can be adjusted.

[0031] The power (rotational power) is changed in speed by the inter-row transmission 25 of the transmission case 21 and transmitted to the seedling planting device 10 via the PTO shaft 27. The power transmitted via the PTO shaft 27 is input to the feed case 28 and then transmitted from the feed case 28 to the seedling planting mechanism 16 and the seedling carrier 17. The seedling planting mechanism 16 uses the transmitted power to drive the planting transmission case 14, which rotates the planting arm 16B. The time required for the planting arm 16B to make one rotation is controlled based on the rotation amount 43 (see Figure 4) of the rotational power input to the planting arm 16B. The seedling planting mechanism 16 is controlled based on the power changed in speed by the continuously variable transmission 22, and is therefore controlled according to the traveling speed. The seedling carrier 17 is fed horizontally or vertically by the transmitted power. The timing of the horizontal feed of the seedling carrier 17 is controlled based on the rotation amount 43 of the rotational power input to the seedling carrier 17.

[0032] [PTO shaft rotation sensor] As described above, the seedling planting device 10 (seedling planting mechanism 16) and the seedling carrier 17 are controlled based on the PTO shaft 27. Next, the configuration of the rotation amount sensor 31 that measures the rotation amount 43 (see FIG. 4) of the PTO shaft 27 will be described with reference to FIG. 3.

[0033] The rotation amount sensor 31 has a plurality of teeth 31A that serve as indicators and a measuring device 31B. The teeth 31A, for example 24 teeth, are arranged at equal intervals around the periphery of the PTO shaft 27 and rotate integrally with the PTO shaft 27 as the PTO shaft 27 rotates. The measuring device 31B counts the number of teeth 31A that pass through predetermined fixed points around the PTO shaft 27 as the PTO shaft 27 rotates. This allows the rotation amount sensor 31 to count the number of teeth 31A measured by the measuring device 31B as the amount of rotation 43 of the PTO shaft 27.

[0034] The measuring instrument 31B may be equipped with any type of sensor, such as a contact sensor, a sonar sensor, or an imaging device and an image analyzer, as long as it is capable of identifying teeth 31A passing by a fixed point and counting the number of teeth 31A passing by. For example, if a sonar sensor is equipped, the sonar is reflected when irradiated onto teeth 31A, but is not reflected when irradiated onto an area without teeth 31A. Therefore, the measuring instrument 31B detects the presence of one tooth 31A when a reflected wave is detected after no reflected wave has been detected, and counts the number of detected teeth 31A.

[0035] [Seedling planting mechanism control] Next, a configuration for controlling the seedling planting mechanism 16 based on the rotation amount 43 of the PTO shaft 27 measured by the rotation amount sensor 31 will be described with reference to FIGS.

[0036] The seedling planting mechanism 16 is controlled by a controller 34. The controller 34 is equipped with a processor such as a CPU, and each functional block of the controller 34 operates under the control of the processor. The controller 34 is connected in a manner that allows communication with the rotation amount sensor 31, the edge-pushing switch 18, the seedling planting mechanism 16, and a memory unit 35. The memory unit 35 stores various types of information.

[0037] The controller 34 has an initialization time acquisition unit 37, a rotation amount acquisition unit 38, and a planting control unit 39.

[0038] The initialization time acquisition unit 37 acquires a push-up signal indicating that the seedling carrier 17 has been moved laterally to one of the left and right ends by the push-up switch 18. The initialization time acquisition unit 37 sets the time when the push-up signal is received (the time when the seedling carrier 17 has been moved laterally to one of the left and right ends by the push-up switch 18) as the start time when the rotation amount sensor 31 starts measuring the rotation amount 43.

[0039] The rotation amount acquiring unit 38 acquires the number of teeth 31A measured by the measuring device 31B, which is the rotation amount 43 measured by the rotation amount sensor 31.

[0040] The planting control unit 39 controls the seedling planting mechanism 16 based on the rotation amount 43 from the start time. That is, the planting control unit 39 sets the start time acquired by the initialization time acquisition unit 37, which is the time when the edge-moving switch 18 detects that the seedling carrier 17 has been moved laterally to one of the left and right ends, as 0, and acquires the number of teeth 31A measured by the rotation amount sensor 31 as the rotation amount 43 (corresponding to rotation amount 43A described below). Then, the planting control unit 39 uses the acquired rotation amount 43 as a reference and outputs a control signal 44 that controls the operation timing of the seedling planting mechanism 16.

[0041] Specifically, the initialization time acquisition unit 37 detects that the seedling carrier 17 has been fed laterally to one of the left and right ends and the edge-pushing switch 18 has been turned on by receiving an edge-pushing signal (step #1 in Figure 5), and sets the time when the edge-pushing signal was received as the start time. Then, when the start time is set, the initialization time acquisition unit 37 turns on the start flag 41 stored in the memory unit 35.

[0042] The rotation amount acquisition unit 38 acquires the number of teeth 31A, which is the rotation amount 43 measured by the rotation amount sensor 31. When the start flag 41 is turned on, the rotation amount 43 at that time is set to 0, and the rotation amount 43 acquired thereafter is corrected to the rotation amount 43A and stored in the memory unit 35. In other words, the rotation amount acquisition unit 38 starts measuring the rotation amount 43A (the number of teeth 31A) of the PTO shaft 27 after the seedling carrier 17 is fed laterally to one of the left and right ends and the edge-aligning switch 18 is turned on (step #2 in Figure 5). The rotation amount 43A corresponds to the rotation amount 43 of the PTO shaft 27 after the seedling carrier 17 is fed laterally to one of the left and right ends and the edge-aligning switch 18 is turned on. When the rotation amount acquisition unit 38 starts measuring the rotation amount 43A, it turns off the start flag 41.

[0043] The planting control unit 39 controls various operations of the seedling planting mechanism 16 based on the rotation amount 43A measured after the edge-shifting switch 18 detects that the seedling carrier 17 has been moved laterally to the edge (step #3 in Figure 5). Specifically, the planting control unit 39 controls the speed change mechanism 46 based on the rotation amount 43A, and transmits the power changed in speed by the speed change mechanism 46 to the seedling planting mechanism 16. The planting control unit 39 controls the seedling planting mechanism 16 in units of the number of teeth 31A, allowing for accurate control of the seedling planting mechanism 16.

[0044] For example, each planting arm 16B plants a seedling in the field during one rotation. Therefore, the spacing between plants is determined by the vehicle's travel speed and the rotational speed of the planting arm 16B. In other words, the spacing between plants can be controlled by controlling the rotational speed of the planting arm 16B. The rotational speed of the planting arm 16B is controlled based on the power transmitted via the PTO shaft 27. In this embodiment, the speed change mechanism 46 controls the rotational power transmitted to the planting arm 16B based on the rotational amount 43A of the PTO shaft 27, which begins when the seedling carrier 17 is moved laterally to one of the left and right ends and the edge-aligning switch 18 is activated. This controls the planting control unit 39 to control the seedling planting mechanism 16 so that the planting arm 16B plants seedlings every predetermined rotational amount 43A.

[0045] Generally, the rotation speed of the planting arm 16B is controlled in rotation speed units based on the rotation speed of the PTO shaft 27. In this embodiment, the rotation amount acquisition unit 38 acquires the rotation amount 43A corresponding to the number of teeth 31A provided around the PTO shaft 27. Therefore, the planting control unit 39 can control the rotation speed of the planting arm 16B in units of the number of teeth 31A, accurately controlling the rotation speed of the planting arm 16B and accurately controlling the planting timing.

[0046] Specifically, if the rotation speed of the planting arm 16B were controlled based on the rotation speed of the PTO shaft 27, it would only be possible to control the planting arm 16B to rotate once per one rotation of the PTO shaft 27, and it was difficult to control the planting arm 16B to rotate once per 1 / 2 or 1 / 3 rotation of the PTO shaft 27. Because the rotation speed of the planting arm 16B can be controlled in units of the number of teeth 31A, the planting arm 16B can be rotated once in increments of less than one rotation depending on the number of teeth 31A provided on the PTO shaft 27. For example, if 24 teeth 31A are provided, it is easy to rotate the planting arm 16B once per 1 / 2 or 1 / 3 rotation of the PTO shaft 27, and it is even possible to rotate the planting arm 16B once per 1 / 24 rotation of the PTO shaft 27.

[0047] [Another embodiment] (1) In the above embodiment, the start time is not limited to the time when the edge shifting switch 18 detects that the seedling carrier 17 has been moved laterally to one of the left and right ends, but the start time for starting to measure the rotation amount 43A may also be determined using an initial identification unit provided on the PTO shaft 27.

[0048] Specifically, a depression 32 is provided as an initial identification part on one of the teeth 31A, and a detector 45 is further provided to detect the depression 32 that moves to a predetermined position as the PTO shaft 27 rotates. The detector 45 determines the start time as the point in time when it detects the depression 32. The rotation amount acquisition unit 38 then controls the seedling planting mechanism 16 based on the rotation amount 43 measured after the detector 45 detects the depression 32.

[0049] With this configuration, the rotation amount acquisition unit 38 can determine the start time and measure the rotation amount 43A in accordance with the rotation of the PTO shaft 27 without using the edge-pushing switch 18. Furthermore, for each rotation of the PTO shaft 27, the rotation amount 43A can be measured in units that are equally divided according to the number of teeth 31A, allowing for accurate control of the rotation speed of the planting arm 16B and accurate control of the planting timing.

[0050] (2) In each of the above embodiments, the rotation amount sensor 31 is not limited to the teeth 31A, and may be provided with any marking such as a protrusion (projection) or pattern that can measure the rotation amount 43 of the PTO shaft 27 in units smaller than one rotation of the PTO shaft 27 as the PTO shaft 27 rotates. With this configuration, the rotation amount sensor 31 can accurately measure the rotation amount 43 (rotation amount 43A) using a marking that is suitable for measuring the rotation amount 43 (rotation amount 43A) of the PTO shaft 27 depending on the PTO shaft 27 and the conditions around the PTO shaft 27.

[0051] (3) In each of the above-described other embodiments, the rotation amount sensor 31 is not limited to a configuration including the teeth 31A and the measuring device 31B, but may have any configuration that can measure the rotation amount 43 of the PTO shaft 27 in units smaller than one rotation of the PTO shaft 27. With such a configuration, the rotation amount sensor 31 can measure the rotation amount 43 (rotation amount 43A) of the PTO shaft 27 with high accuracy, in a configuration that is suitable for measuring the rotation amount 43 (rotation amount 43A) of the PTO shaft 27 depending on the conditions of the PTO shaft 27 and the surrounding area of ​​the PTO shaft 27.

[0052] (4) In each of the above-described other embodiments, the control based on the rotation amount 43A is not limited to a configuration that controls the rotation speed of the planting arm 16B, but may also be a configuration that controls the lateral feed speed of the seedling carrier 17, other operations of the seedling planting mechanism 16, or operations of other devices of the rice transplanter. This allows various controls of the rice transplanter to be performed with high precision.

[0053] (5) In each of the above-described other embodiments, the edge shifting switch 18 may be provided on only one of the left and right sides of the seedling carrier 17, or may be provided on both the left and right sides. This makes it possible to detect when the seedling carrier 17 has been fed laterally to both the right and left ends.

[0054] As a result, the rotation amount 43A of the PTO shaft 27 can be measured starting from the point when the seedling carrier 17 is fed laterally to both the left and right ends. This increases the start time for measuring the rotation amount 43A of the PTO shaft 27, allowing for more accurate control of the rotation speed of the planting arm 16B and more accurate control of planting timing.

[0055] Here, the seedling removal amount associated with the seedling planting work may be calculated using the edge-removal switch 18. The seedling removal amount is used to estimate the number of mat-shaped seedlings that need to be prepared for planting seedlings in the field, to plan the timing of seedling replenishment, and to make adjustments to these.

[0056] The seedling quantity is calculated based on the time from when the mat-shaped seedlings are placed on the seedling tray 17 until the seedling quantity sensor 19 no longer detects the mat-shaped seedlings, and the distance from the seedling quantity sensor 19 to the position where the mat-shaped seedlings are placed on the seedling tray 17. If it is precisely known at which end, left or right, the seedling quantity sensor 19 no longer detects the mat-shaped seedlings, the amount of seedlings to be removed can be calculated with high accuracy. By providing edge adjustment switches 18 on both the left and right, it is possible to determine at which end, left or right, the seedling quantity sensor 19 detected the mat-shaped seedlings, thereby accurately calculating the amount of seedlings to be removed.

[0057] (6) In each of the above embodiments, the controller 34 is not limited to being configured with the above-described functional blocks, but may be configured with any functional blocks. For example, each functional block of the controller 34 may be further subdivided, or conversely, some or all of the functional blocks may be combined. At least one of the controller 34 and the storage unit 35 may be provided in the information terminal 4, an external management server, or the like. The functions of the controller 34 are not limited to the above-described functional blocks, but may be realized by a method executed by any functional block. Some or all of the functions of the controller 34 may be configured with software. A program related to the software is stored in any storage device, such as the storage unit 35, and executed by a processor, such as a CPU, provided in the controller 34 or a separately provided processor.

[0058] (7) In each of the above-mentioned other embodiments, the control performed based on the rotation amount 43A of the PTO shaft 27 is not limited to rice transplanters, and may be used in other agricultural machines and other implements that operate work equipment using power transmitted via the PTO shaft 27. [Industrial Applicability]

[0059] The present invention can be applied to various types of work machines, such as rice transplanters, which operate work implements using power transmitted via a PTO shaft. [Explanation of symbols]

[0060] 16 Seedling planting mechanism 16B Planting arm 17 Seedling stand 18 Edge switch 27 PTO shaft 31 Rotational amount sensor 31A Tooth (label) 31B Measuring Instruments 32 Depression (initial identification part) 34 Controller 35 Storage section 37 Initialization time acquisition section 43 Rotation amount 43A Rotation Amount

Claims

1. a PTO shaft that transmits power as rotational power; A seedling carrier on which mat-shaped seedlings are placed and which is fed vertically and horizontally by the power transmitted through the PTO shaft; a seedling planting mechanism for removing seedlings from the mat-like seedlings and planting them in a field; a rotation amount sensor that measures the rotation amount of the PTO shaft; an initialization timing acquisition unit that acquires a start timing at which the rotation amount sensor starts measuring the rotation amount; A rice transplanter comprising a controller that controls the seedling planting mechanism based on the amount of rotation measured by the rotation amount sensor from the start time acquired by the initialization time acquisition unit.

2. The rotation amount sensor a plurality of markers arranged along the circumference of the PTO shaft; a measuring instrument for measuring the number of the markers passing through a fixed point around the PTO axis; The rice transplanter according to claim 1, wherein the number of the markers measured by the measuring instrument is measured as the amount of rotation.

3. The rice transplanter according to claim 2, wherein the mark is a protrusion.

4. An edge shifting switch is provided to detect that the seedling carrier is fed laterally to at least one end in the left and right direction, The initialization time acquisition unit acquires the time when the edge shifting switch detects that the seedling tray has been laterally fed to the end as the start time, The rice transplanter according to claim 1, wherein the controller controls the seedling planting mechanism based on the amount of rotation measured after the edge shifting switch detects that the seedling carrier has been fed laterally to the end.

5. the initialization timing acquisition unit has an initial identification unit provided on the PTO shaft and a detector that detects the initial identification unit that has moved to a predetermined position as the PTO shaft rotates, and acquires the time point at which the initial identification unit is detected as the start timing; The rice transplanter according to claim 1 , wherein the controller controls the seedling planting mechanism based on the amount of rotation measured after the detector detects the initial identification portion.

6. The seedling planting mechanism has a pair of rotary planting arms, The pair of planting arms alternately remove the seedlings from the mat of seedlings and plant them in the field; The rice transplanter according to any one of claims 1 to 4, wherein the controller controls the seedling planting mechanism so that the planting arm plants the seedlings for each predetermined rotation amount.

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