Transplanter

Abstract

To provide a transplanter which can improve safety when an operator attempts to manually rotate a planting rotary body in a stopped state in a configuration where the planting rotary body is rotationally driven by an electric motor.SOLUTION: A transplanter comprises: a traveling machine body 2; a planting section which is supported by the traveling machine body 2 and has a planting rotary body that supports planting claws 92 and is rotatably provided; an electric motor 42 which rotationally drives the planting rotary body; and a controller 50 which controls the electric motor 42. The controller 50 performs torque reduction control in which a torque limit value of the electric motor 42 during the travel stop of the traveling machine body 2 is set smaller than a torque limit value during the travel of the traveling machine body 2.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a transplanter having a configuration in which a planting rotor is rotated by an electric motor. [Background technology]

[0002] In a conventional rice transplanter that continuously plants seedlings in a field using a planting device, a plate-shaped seedling mat placed on a seedling carrier that slopes downward at the rear is fed horizontally and vertically, and the planting claws of the planting device continuously scrape off the seedling mat one portion at a time to plant the seedlings. This type of rice transplanter is equipped with a rotary-type planting device as the planting device, which has a planting transmission case, a rotary case that is a planting rotor provided on both the left and right sides of the planting transmission case, and a planting claw device that includes planting claws supported by the rotary case.

[0003] Among such rice transplanters, there is one in which the rotary case is rotated using the driving force of an electric motor (see, for example, Patent Document 1). Patent Document 1 discloses a configuration in which a pair of left and right rotary cases are rotated by one electric motor, and a configuration in which one electric motor is provided for each rotary case. Patent Document 1 also describes, with regard to rotary case operation control, a control in which the rotary case is stopped at a phase where the planting tines are away from the field surface (the so-called upper stop position) by driving control of the electric motor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5335446 Summary of the Invention [Problem to be solved by the invention]

[0005] The upper stop position of the rotary case is a phase set from the viewpoint of preventing the planting claws from contacting the ground when the planting device is lowered or from interfering with the seedling tray when the seedling tray is fed laterally. In a configuration in which the rotary case is driven to rotate using the driving force of an electric motor, for example, by performing a predetermined stopping operation on the rotation of the rotary case, the rotary case is controlled to move (rotate) from the phase at the time of the operation to the upper stop position and stop rotation.

[0006] When the rotary case is stopped at the upper stop position by the control of the electric motor, a torque is applied to stop the rotation of the rotary case by the drive control of the electric motor. In other words, when the rotary case is stopped at the upper stop position, it is receiving torque from the electric motor as a drive source.

[0007] On the other hand, workers may attempt to manually rotate the stopped rotary case to clear seedling jams or perform maintenance on the rotary case or planting claw device. When such an operation is performed, the rotary case, which is stopped at the upper stop position, attempts to return to the commanded upper stop position due to torque from the electric motor. This automatic rotation of the rotary case can be unexpected for the worker, and there is a risk that the worker's hand may be caught in the rotary case or the rotary case may hit the worker, so there is room for improvement in terms of safety.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a transplanter that is configured to rotate the planting rotor using an electric motor, and that can improve safety when an operator attempts to manually rotate a planting rotor that is in a stopped state. [Means for solving the problem]

[0009] The transplanter of the present invention comprises a running body, a planting unit supported on the running body and having a planting rotor that supports the planting claws and is rotatably arranged, an electric motor for driving the planting rotor to rotate, and a control unit for controlling the electric motor, wherein the control unit performs torque reduction control to reduce the torque limit value of the electric motor when the running body is stopped compared to the limit value when the running body is running.

[0010] The transplanter of the present invention comprises a running body, a planting unit supported on the running body and having a planting rotor that supports planting claws and is rotatably arranged, an electric motor for driving the planting rotor to rotate, and a control unit for controlling the electric motor, wherein the control unit performs torque reduction control to reduce the torque limit value of the electric motor when the planting unit is in a non-working position relative to the limit value when the planting unit is in a working position.

[0011] The transplanter of the present invention comprises a running body, a planting unit supported on the running body and having a planting rotor that supports the planting claws and is rotatably arranged, an electric motor for driving the planting rotor to rotate, and a control unit for controlling the electric motor, and the control unit performs torque reduction control to reduce the torque limit value of the electric motor when the running body is stopped compared to the limit value when the planting unit is being raised and lowered.

[0012] The transplanter of the present invention comprises a running body, a planting unit supported on the running body and having a planting rotor that supports planting claws and is rotatably arranged, an electric motor for driving the planting rotor to rotate, and a control unit for controlling the electric motor, and the control unit performs torque reduction control to reduce the torque limit value of the electric motor compared to the limit value while the running body is running, on the condition that it detects that an external force has acted on the planting rotor while the running body is stopped.

[0013] In the transplanter of the present invention, the control unit releases the torque reduction control under at least one of the following conditions: the start of movement of the running body is detected while the running body is stopped; an operation to raise or lower the planting unit is performed; and an operation to rotate the planting rotor is performed. [Effects of the Invention]

[0014] According to the present invention, in a configuration in which a planting rotor is driven to rotate by an electric motor, safety can be improved when an operator attempts to manually rotate a planting rotor that is in a stopped state. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a left side view of a rice transplanter according to an embodiment of the present invention. [Figure 2] FIG. 1 is a plan view of a rice transplanter according to an embodiment of the present invention. [Figure 3] FIG. 1 is a plan view showing a power transmission configuration provided in a rice transplanter according to one embodiment of the present invention. [Figure 4] FIG. 1 is a block diagram showing the power and power transmission configuration of a rice transplanter according to one embodiment of the present invention. [Figure 5] FIG. 2 is a block diagram showing a control configuration of the rice transplanter according to one embodiment of the present invention. [Figure 6] FIG. 1 is a left side view showing the configuration of a seedling planting device and its surroundings according to an embodiment of the present invention. [Figure 7] FIG. 2 is a left side view of the lower structure of the planting device according to one embodiment of the present invention. [Figure 8] FIG. 2 is a plan view of the lower structure of the planting device according to one embodiment of the present invention. [Figure 9] 10A and 10B are explanatory diagrams of upper stop control according to an embodiment of the present invention. [Figure 10] FIG. 4 is an explanatory diagram of torque reduction control according to an embodiment of the present invention. [Figure 11]4 is a flowchart showing an example of a control mode of torque reduction control according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention aims to improve safety when an operator tries to manually rotate the planting rotor to clear seedling jams, etc., by devising a control method for the electric motor in a configuration in which the planting rotor is rotated by an electric motor. The following describes an embodiment of the present invention.

[0017] The configuration of a rice transplanter 1 as a transplanter according to this embodiment will be described with reference to Figures 1 to 8. In the following description, the left side (left side in Figure 2) and the right side (right side in Figure 2) when facing the front of the rice transplanter 1 will be referred to as the left side and right side of the rice transplanter 1, respectively.

[0018] As shown in Figures 1 and 2, the rice transplanter 1 of this embodiment is a riding rice transplanter that performs planting work while traveling with an operator inside, and is used to plant seedlings sequentially in a field.

[0019] The rice transplanter 1 comprises a traveling body 2 that constitutes a self-propelled traveling section, and a planting device 3 that serves as a planting section that is provided behind the traveling body 2. The planting device 3 is connected to the rear of the traveling body 2 so that it can be raised and lowered via a lifting link mechanism 4 that includes multiple links. While traveling on the traveling body 2, the rice transplanter 1 plants seedlings in a paddy field 6 that serves as a farm scene in a field 5 using the planting device 3.

[0020] The traveling machine body 2 has a machine body frame 7, left and right front wheels 8, and left and right rear wheels 9. The machine body frame 7 is configured in a framework shape using multiple frame members, and has a front frame section 11 that forms a horizontal frame portion, and a rear frame section 12 that forms a stepped section that is one step higher behind the front frame section 11. The left and right front wheels 8 are provided below the front frame section 11, and the left and right rear wheels 9 are provided below and behind the rear frame section 12. The machine body frame 7 is supported on the field by the left and right front wheels 8 and the left and right rear wheels 9. For convenience, the rear wheels 9 are shown in FIG. 1 by virtual lines (chain double-dashed lines).

[0021] A horizontal floor 13 made of a vehicle body cover or the like is provided above the front frame 11 of the traveling body 2. A driver's unit 10 for driving and operating the traveling body 2 and the planting device 3 is provided on the floor 13. A driver's seat 15 is provided in the center of the left and right rear of the driver's unit 10. A fuel tank (not shown) is provided below the seat 15.

[0022] An operating unit 16 is provided in front of the driver's unit 10 and is operated by an operator seated in a seat 15. The operating unit 16 is provided with a dashboard 18 on which a steering wheel 17 and the like are arranged, various operation pedals such as an accelerator pedal 105 (see FIG. 5) and a brake pedal, and various operation levers such as a speed change lever including a main speed change lever, a planting clutch lever, and a lift operation lever 104 (see FIG. 5).

[0023] An engine 20 serving as a drive source is provided in the center of the left and right sides of the front of the machine frame 7. The engine 20 is covered by a hood 21. The engine 20 is mounted on the front of the front frame portion 11 via vibration-isolating rubber or the like. The engine 20 is, for example, a diesel engine. Note that a motor or the like may also be mounted as a drive source for the rice transplanter 1.

[0024] A transmission 22, which has a power transmission mechanism including gears, brakes, etc. built into a transmission case, is provided behind the engine 20 on the underside of the traveling body 2. The power of the engine 20 is transmitted to the transmission 22 and used to drive the front wheels 8 and rear wheels 9.

[0025] Front axle cases 25 are attached to both the left and right sides of the transmission 22. A front axle 26 is rotatably supported by the front axle case 25, and front wheels 8 are attached to the front axle 26. A power transmission mechanism provided within the front axle case 25 transmits the rotational power of the transmission 22 to the front axle 26, thereby driving the front wheels 8 to rotate.

[0026] A rear axle case 28 is provided behind the transmission 22. The rear axle case 28 is connected to the transmission 22 via a connecting frame 29 that extends in the front-to-rear direction. The rear axle case 28 receives power from the transmission 22 via a transmission shaft 31 that extends from the rear of the transmission 22 and is arranged parallel to the connecting frame 29.

[0027] The rear axle case 28 has protruding case sections 28a on both the left and right sides that protrude rearward relative to the case main body. A rear axle 32 is rotatably supported by the left and right case sections 28a, and a rear wheel 9 is attached to the rear axle 32. A power transmission mechanism provided within the rear axle case 28 transmits the rotational power of the transmission 22 to the rear axle 32, thereby driving the rear wheel 9 to rotate.

[0028] In the traveling body 2, multiple stages (three stages in the example shown in FIG. 1) of spare seedling trays 33 are provided at positions on the left and right outer sides of the hood 21. Supplementary seedling mats are placed on the spare seedling trays 33.

[0029] As shown in Figures 3 and 4, the rice transplanter 1 is configured as a hybrid rice transplanter, and includes, in addition to the engine 20, a motor generator 41 as a first rotating electric machine, an electric motor 42 as a second rotating electric machine, and a battery 43. In Figure 4, thick solid lines connecting elements indicate power lines, and thick dashed lines connecting elements indicate signal lines. Also, the outline arrows indicate the direction of power transmission.

[0030] The motor generator 41 is connected to the engine 20 via a power transmission unit so that power can be transmitted thereto. This power transmission unit is configured to directly or indirectly connect the rotating shaft of the motor generator 41 to the output shaft of the engine 20. A transmission, a clutch for switching between on and off of power, and the like are appropriately interposed between the motor generator 41 and the engine 20.

[0031] The motor generator 41 has both a function as a motor that provides power to the output of the engine 20 to assist the output of the engine 20, and a function as a generator that generates electricity by rotating with the output of the engine 20. The motor generator 41 functions as a three-phase AC motor when three-phase AC power is input, and rotates when power is input and functions as a three-phase AC generator. The motor generator 41 is controlled by a control device 50 (see FIG. 5) provided in the rice transplanter 1 via a first inverter 46.

[0032] The electric motor 42 supplies driving force to the planting device 3. In other words, the electric motor 42 is a power source provided separately from the engine 20 as a configuration for supplying power to drive the planting device 3. The electric motor 42 is a three-phase AC motor driven by three-phase AC power. The electric motor 42 is controlled by a control device 50 provided in the rice transplanter 1 via a second inverter 47. The configuration of the electric motor 42 (type of motor) is not particularly limited.

[0033] The battery 43 is supported at a predetermined location on the vehicle frame 7. The battery 43 is formed of a secondary battery such as a lead-acid battery or a lithium-ion battery. The battery 43 is formed, for example, by unitizing a plurality of battery modules each made of a secondary battery. The battery 43 is electrically connected to the motor generator 41 and the electric motor 42.

[0034] The battery 43 is electrically connected to the motor generator 41 via the first inverter 46 and supplies power to the motor generator 41 via the first inverter 46. The motor generator 41 can supply power to the battery 43 via the first inverter 46. In other words, the motor generator 41 can charge the battery 43. The first inverter 46 converts DC power output from the battery 43 into AC power and supplies it to the motor generator 41. The first inverter 46 also converts AC power output from the motor generator 41 into DC power and supplies it to the battery 43.

[0035] Furthermore, the battery 43 is electrically connected to the electric motor 42 via the second inverter 47, and supplies power to the electric motor 42 via the second inverter 47. The second inverter 47 converts DC power output from the battery 43 into AC power and supplies it to the electric motor 42. Note that, although the present embodiment employs a configuration in which an inverter is provided for each of the motor generator 41 and the electric motor 42, a configuration in which one inverter is shared by both may also be employed.

[0036] A junction box 48 is provided between the battery 43 and the first inverter 46 (motor generator 41) and the second inverter 47 (electric motor 42) (see FIG. 4). The junction box 48 has relays for switching the electrical connections between the battery 43 and each of the first inverter 46 and the second inverter 47 between a connected state and a disconnected state.

[0037] Junction box 48 also has a relay for switching between a connected state and a disconnected state the electrical connection between first inverter 46 and second inverter 47, in other words, the electrical connection between motor generator 41 and electric motor 42. When motor generator 41 and electric motor 42 are electrically connected to each other, it becomes possible to supply electric power generated by motor generator 41 to electric motor 42. Note that a configuration may be adopted in which each relay is provided individually, without providing junction box 48.

[0038] In the above configuration, the electric motor 42 is driven by power supplied from at least one of the battery 43 and the motor generator 41. The motor generator 41 can supply power to the electric motor 42 while charging the battery 43. The battery 43 can supply power to the motor generator 41 and the electric motor 42 simultaneously. The first inverter 46, the second inverter 47, and the junction box 48 are provided in predetermined locations in the traveling machine body 2.

[0039] The motor generator 41 is connected to the transmission 22 so as to be able to transmit power thereto. The motor generator 41 is disposed behind the transmission 22. However, the location of the motor generator 41 is not particularly limited.

[0040] When functioning as a motor, the motor generator 41 assists the output of the engine 20 via the transmission 22. When functioning as a generator, the motor generator 41 generates electricity by rotating using the driving force from the engine 20 transmitted via the transmission 22. Power is transmitted from the engine 20 to the motor generator 41, for example, so that the rotation speeds of both are the same. The electric power generated by the motor generator 41 is supplied to at least one of the battery 43 and the electric motor 42 via a first inverter 46 and a junction box 48.

[0041] The electric motor 42 is disposed above the rear axle case 28 at a position to the right of the center in the left-right direction, and is supported by the vehicle frame 7 or the like. However, the position where the electric motor 42 is disposed is not particularly limited.

[0042] The motor generator 41 and the electric motor 42 may be connected to each other so that power can be transmitted between them via a switching mechanism such as a clutch that switches between on and off of power. With this configuration, for example, if a problem occurs with the electric motor 42, the planting device 3 can be driven using the output of the engine 20 instead of the output of the electric motor 42. Furthermore, the driving force of the electric motor 42 can assist the output of the engine 20 in addition to the assistance of the engine 20 by the motor generator 41.

[0043] The planting device 3 will now be described. The planting device 3 is supported on the rear side of the traveling body 2 and functions as a ground working unit that plants seedlings in the paddy field surface 6 of the farm field 5. The planting device 3 is connected to the rear of the traveling body 2 via a lifting link mechanism 4 (see Figure 1) to the machine frame 7 so that it can be raised and lowered.

[0044] The lifting link mechanism 4 has a top link 61 extending in the front-rear direction and a pair of left and right lower links 62. The front side of each link is rotatably connected to a vertical link frame 63, and the rear side of each link is rotatably connected to a hitch bracket 64 provided on the front side of the planting device 3. The vertical link frame 63 is erected on the rear axle case 28 at the rear end of the traveling body 2 and is connected to the rear of the rear frame section 12.

[0045] The base end (front side) of a hydraulic lifting cylinder 65 is supported on the upper side of the connecting frame 29 so as to be able to rotate up and down (see Figure 1). The lifting cylinder 65, together with the lifting link mechanism 4, constitutes a lifting device that raises and lowers the planting device 3 relative to the traveling body 2. The tip end (rear side) of the lifting cylinder 65 is connected to the front end of the lower link 62. As the lifting cylinder 65 extends and retracts, each link of the lifting link mechanism 4 rotates up and down, raising and lowering the planting device 3. That is, as the lifting cylinder 65 extends, the planting device 3 descends, and as the lifting cylinder 65 retracts, the planting device 3 rises. The extension and retraction of the lifting cylinder 65 is controlled by controlling the hydraulic flow rate discharged from a hydraulic pump driven by power output from the engine 20.

[0046] The planting device 3 comprises a planting frame 71 connected to the rear side of the lifting link mechanism 4, a planting transmission case 72, a seedling carrier 73 supported by the planting frame 71, and a seedling planting device 80 driven by power transmitted from the planting transmission case 72.

[0047] The planting frame 71 is composed of multiple frame members, such as multiple vertical frames and horizontal frames, and is configured to have a roughly frame-like shape when viewed from the front. The planting frame 71 has a main frame 75 as a horizontal frame attached to its lower part. The main frame 75 is a linear frame member with a rectangular cylindrical outer shape with a roughly square cross section, and is installed horizontally so as to extend in the left-right direction. The main frame 75 is located below the seedling carrier 73 and is installed across almost the entire left-right range of the planting device 3.

[0048] The planting transmission case 72 is provided in the center of the left and right sides of the main frame 75. The planting transmission case 72 is provided in an overhanging shape so that its rear portion is positioned on the rear side of the main frame 75, and has an overhanging portion to the rear.

[0049] The planting transmission case 72 receives the driving force of the electric motor 42 via a transmission shaft 76. The planting transmission case 72 incorporates a power transmission mechanism composed of a gear train including gears such as bevel gears, and the input shaft 72a protrudes forward. The electric motor 42 has its output shaft 42a protrude toward the rear.

[0050] The front end of the transmission shaft 76 is connected to the output shaft 42a of the electric motor 42 via a universal joint 77. The rear end of the transmission shaft 76 is connected to the input shaft 72a of the planting transmission case 72 via a universal joint 78. A transmission device composed of speed increasing / decreasing gears, a speed change mechanism, etc. may be provided between the electric motor 42 and the planting transmission case 72.

[0051] The seedling carrier 73 is located above the planting transmission case 72 and behind the planting frame 71. The seedling carrier 73 has a surface on its front side (upper rear side) for receiving a seedling mat (not shown), and the surface is sloped downward toward the rear. The planting device 3 according to this embodiment has an eight-row planting configuration and has eight seedling carrier sections 79 lined up in the left-right direction (see Figure 2).

[0052] The seedling carrier 73 supplies seedling mats placed on each seedling carrier section 79 to each planting unit. The seedling carrier 73 is configured to be able to move back and forth in the left and right direction by a drive mechanism (lateral feed mechanism) not shown in the figure, so that the seedling mats are continuously fed back and forth in the left and right direction. A vertical feed mechanism is provided for the seedling carrier 73, which feeds the seedling mats on each seedling carrier section 79 vertically downward when the seedling carrier 73 reaches the left and right ends of its reciprocating movement. These horizontal feed mechanisms and vertical feed mechanisms are driven by power transmitted to the planting transmission case 72.

[0053] The seedling planting device 80 is a rotary-type planting device that has a planting transmission case 81, two rotary cases 82 as planting rotors supported on both the left and right sides of the planting transmission case 81, and a planting claw device 90 provided for each rotary case 82. The planting device 3 has eight rotary cases 82, corresponding to an eight-row planting configuration. On both the left and right sides of the planting transmission case 81, the rotary cases 82 and the two planting claw devices 90 form a planting unit.

[0054] The planting transmission case 81 has a cylindrical outer shape with the longitudinal direction being the front-to-rear direction, and its front end is fixed to the rear surface of the main frame 75, extending horizontally from the rear side of the main frame 75 toward the rear. A planting transmission case 81 is provided for every two rows, and there are four planting transmission cases 81 in the eight-row planting rice transplanter 1. The four planting transmission cases 81 are arranged at approximately equal intervals in the left-to-right direction.

[0055] The planting transmission case 81 receives power from the planting transmission case 72 via a planting transmission shaft 85 whose axial direction is in the left-right direction. In other words, the planting transmission shaft 85 interlocks and connects the power transmission mechanisms in each of the planting transmission cases 72 and 81. The planting transmission shaft 85 is rotatably supported relative to the planting transmission case 72 at a position behind the main frame 75, passing through the rear of the planting transmission case 72. The planting transmission shaft 85 is installed between the front parts of the four planting transmission cases 81, and is rotatably supported relative to the planting transmission cases 81, passing through each planting transmission case 81, extending in the left-right direction.

[0056] A pair of rotary cases 82 (two rows) are provided on both the left and right sides of the rear of the planting transmission case 81. The rotary cases 82 are rotatably attached to the planting transmission case 81 by a drive shaft 86 whose axial direction is in the left-right direction (see Figure 6). The drive shaft 86 protrudes to the left and right sides from the planting transmission case 81, and supports the left and right rotary cases 82 rotatably relative to the planting transmission case 81.

[0057] The rotary case 82 has a longitudinal outer shape, and its longitudinal center is axially supported by the planting transmission case 81. Two planting claw devices 90 are attached to the left and right outer sides of the rotary case 82. The two planting claw devices 90 are arranged on opposite sides of the rotary case 82 with respect to the position of the drive shaft 86, and are provided at both longitudinal ends of the rotary case 82.

[0058] The planting claw devices 90 are supported on both longitudinal ends of the rotary case 82 so as to be rotatable about a rotation axis 87 whose rotation axis is in the left-right direction (see Figure 6). The planting claw devices 90 are connected to the rotary case 82 so as to be linked to the rotation of the rotary case 82 relative to the planting transmission case 81. The planting claw devices 90 are configured to perform a predetermined planting operation in conjunction with the rotation of the rotary case 82. By performing the planting operation, the planting claw devices 90 sequentially scrape off the seedling mat placed on the seedling carrier 73 one by one and plant them in the field. With one rotation of the rotary case 82, the two planting claw devices 90 cut seedlings one by one from the seedling mat placed on the seedling carrier 73 and plant them in the paddy field 6.

[0059] As shown in FIG. 6, the planting claw device 90 has an arm 91, a planting claw 92 fixed to the arm 91, and a pusher member 93 movable relative to the arm 91. The planting claw device 90 has a base 90a as the connection portion to the rotary case 82, and an extension portion in which the arm 91, planting claw 92, etc. extend linearly from the base 90a in a predetermined direction, with the tip of the planting claw 92 being the tip of the extension portion. Hereinafter, the direction along the extension direction of the extension portion of the planting claw device 90 will be referred to as the "claw extension direction." In addition, in the planting claw device 90, the tip side of the planting claw 92 in the claw extension direction will be referred to as the front side, and the opposite side will be referred to as the rear side.

[0060] The arm portion 91 is a substantially cylindrical portion whose cylindrical axis direction is the claw extension direction of the planting claw device 90. The arm portion 91 is an integral part of the base portion 90a and extends from the base portion 90a in the claw extension direction.

[0061] The planting claw 92 has a roughly rectangular plate-shaped claw base 92a and a bifurcated claw body 92b extending forward from one longitudinal side of the claw base 92a along the claw extension direction. The planting claw 92 has a roughly constant width overall, with the width direction being the left-right direction and the length direction being aligned with the claw extension direction. The planting claw 92 has the claw base 92a fixed to the upper side of the arm 91 by two fixing parts 96. The fixing parts 96 are fastening fixing parts that protrude upward from the arm 91 and have male threads that penetrate the claw base 92a and have nuts threaded into them. The planting claw 92 has a sharpened tip 92c of the claw body 92b.

[0062] The pusher member 93 is provided on the front side of the arm portion 91 and is configured to move back and forth along the claw extension direction relative to the arm portion 91. The pusher member 93 is provided below the claw body portion 92b of the planting claw 92. The pusher member 93 has a push rod portion 93a and a pressing piece portion 93b provided on the tip side of the push rod portion 93a.

[0063] The push rod portion 93a is a rod portion that forms a cylinder mechanism together with the arm portion 91, with the arm portion 91 serving as the cylinder portion, and extends from the tip of the arm portion 91 in the claw extension direction. The push rod portion 93a moves back and forth relative to the arm portion 91 so as to change the amount of protrusion from the arm portion 91. The pressing piece portion 93b is a portion that moves integrally with the push rod portion 93a relative to the arm portion 91, and is the portion that applies pressure to the seedling blocks scraped from the seedling mat.

[0064] The pusher member 93 is arranged to move back and forth relative to the arm portion 91 between a holding position, which is the rear end position, and a pushing position, which is the front end position. The holding position of the pusher member 93 is the standby position of the pusher member 93 in the planting claw device 90, where it holds the picked seedlings. The pushing position of the pusher member 93 is the forward end position of the pusher member 93 relative to the arm portion 91, where the planting claw device 90 has pushed out (released) the seedling blocks. The pusher member 93 is arranged to move forward relative to the arm portion 91 with a biasing force, pushing out the seedling blocks in a manner that ejects them.

[0065] In the above configuration, the rotational power generated by the electric motor 42 is transmitted to the rotary case 82 via the transmission shaft 76, the planting transmission case 72, the planting transmission shaft 85, and the planting transmission case 81. That is, the planting device 3 receives driving force from the electric motor 42 via the transmission shaft 76 in the planting transmission case 72, and the driving force input to the planting transmission case 72 is transmitted to the planting transmission shaft 85 by a power transmission mechanism within the planting transmission case 72. The rotational driving force of the planting transmission shaft 85 is distributed to the four seedling planting devices 80 and transmitted to the drive shafts 86 of the rotary cases 82 on both the left and right sides of the planting transmission case 81 via multiple transmission shafts, gears, etc. provided within the planting transmission case 81. The rotational driving of the drive shafts 86 rotates the left and right rotary cases 82, allowing the planting claw devices 90 to continuously plant seedlings. In this embodiment, eight rotary cases 82 for eight rows rotate synchronously, and eight rows are planted simultaneously.

[0066] As shown by the dashed line in Figure 6, each planting claw device 90 rotates along a trajectory A1 at the tip 92c of the planting claw 92 as the rotary case 82 rotates, scraping the seedling mat and planting the seedling blocks in one cycle. The trajectory A1 is a closed (loop-shaped) trajectory with a vertically elongated, approximately elliptical shape. The trajectory A1 is the trajectory of the body of the rice transplanter 1, i.e., it does not take into account the movement of the planting claw 92 relative to the field as the body moves forward, and is a stationary trajectory based on the body.

[0067] In the left side view shown in Figure 6, the tip 92c of the planting claw 92 moves counterclockwise on trajectory A1 (see arrow B1). Trajectory A1 is a common trajectory for the two planting claw devices 90 supported on the rotary case 82. The rotary case 82 rotates as the machine body moves forward, planting seedlings continuously in a line with a predetermined spacing between plants (seedling planting intervals) using the two planting claw devices 90.

[0068] As shown in Figures 7 and 8, the planting device 3 is equipped with a plurality of floats 110 for leveling the rice field surface, which are located below the seedling planting device 80 in a side view. Note that the planting units (the rotary case 82 and the planting claw device 90) are not shown in Figures 7 and 8. Also, the floats 110 are not shown in Figure 2.

[0069] The floats 110 are provided in a height-adjustable manner on the planting device 3 that plants seedlings in the field 5. The rice transplanter 1 according to this embodiment has the following floats 110: a center float 111 located in the center in the left-right direction, inner side floats 112 provided on the left and right sides of the center float 111, and outer side floats 113 provided on the left and right outer sides of the inner side float 112. These five floats 110 are arranged symmetrically. These floats 110 support various components of the planting device 3, such as the planting transmission case 81, above the rice field surface 6.

[0070] The center float 111 and the inner side float 112 have front wide portions 111a, 112a that are roughly horizontally elongated rectangular in plan view and rear narrow portions 111b, 112b that are roughly vertically elongated rectangular in plan view, and are configured as a roughly "T" shape in plan view as a whole (see Figure 8). The outer side float 113 has a front wide portion 113a that is roughly horizontally elongated rectangular in plan view and a rear narrow portion 113b that extends rearward from a position biased to the left or right inner side of the front wide portion 113a.

[0071] The planting depth of the seedlings relative to the rice field surface 6 is adjusted by adjusting the height of the float 110, i.e., by adjusting its vertical position. In the planting device 3, a float support shaft 115 is provided below the front end of the planting transmission case 81. The float support shaft 115 is supported so as to be rotatable about its axis and extends left and right so as to cover the range in which all of the floats 110 are arranged. The float support shaft 115 is located above the front wide portions 111a, 112a, 113a of each float 110 in the front-rear direction.

[0072] A plurality of planting depth arms 120 that rotate integrally with the float support shaft 115 extend rearward. Each planting depth arm 120 supports a corresponding float 110. The tip of each planting depth arm 120 is rotatably connected to a support bracket 125 provided on the corresponding float 110.

[0073] The planting depth arm 120 has a pair of left and right arm main bodies 121 that are parallel to each other. The support bracket 125 is provided on the rear narrow portion (111b, 112b, 113b) of each float 110 and has a pair of support pieces that face each other in the left-right direction. The tip of each arm main body 121 of the planting depth arm 120 is connected and supported by a support shaft 126 that is installed between the left and right support pieces of the support bracket 125. As a result, the float 110 is supported by the planting depth arm 120 so that it can swing around the support shaft 126.

[0074] A sensing arm 128 of an elevation sensor unit 130, which is a float angle detector, is attached to the front end of the center float 111. The elevation sensor unit 130 detects changes in the float inclination angle (planting depth). A float accommodation mechanism 129 that restricts the up and down movement range of the front end of each float 110 is attached to the front end of each of the inner side float 112 and outer side float 113.

[0075] The lifting / lowering sensor unit 130 functions as a working state detection means that detects the working state of the planting device 3. The lifting / lowering sensor unit 130 has a float angle detection sensor 131 that forms a sensor body that detects the amount of rotation of the detection rotation shaft (see FIG. 8). The float angle detection sensor 131 is, for example, a rotary potentiometer. The float angle detection sensor 131 is connected to the control device 50 by a cable that includes signal lines and the like (see FIG. 5). The float angle detection sensor 131 functions as a ground detection unit that detects the ground contact of the planting device 3 with the field 5.

[0076] The lifting / lowering sensor unit 130 detects that the planting device 3 is in contact with the paddy field surface 6 (in contact mode), which indicates that the planting device 3 is performing planting work. When the float angle detection sensor 131 in the lifting / lowering sensor unit 130 detects that the depression angle of the center float 111 is equal to or greater than a predetermined value, the control device 50 determines that the planting device 3 is not in contact with the paddy field surface 6 (in non-contact mode), i.e., that the planting device 3 is not performing planting work. Here, when the depression angle of the center float 111 is equal to or greater than the predetermined value, the center float 111 is at an angle where it does not contact the paddy field surface 6, and in this state the center float 111 is in non-contact mode.

[0077] In this way, the control device 50 uses a predetermined value for the depression angle of the center float 111 as a reference and determines that a state in which the planting device 3 is in a planting operation state when the depression angle is less than the predetermined value and part of the planting device 3 is in contact with the rice field surface 6, and a state in which the depression angle is greater than the predetermined value and the planting device 3 is not in contact with the rice field surface 6 is determined to be a non-planting operation state.

[0078] The float angle detection sensor 131, which detects the float angle, also constitutes part of a control mechanism that controls the planting depth so that the planting depth of seedlings by the planting device 3 is maintained at a set depth. To control the planting depth, a planting depth adjustment member is used. The planting depth adjustment member is connected to a part that moves due to a drive source such as a motor and rotates around the float support shaft 115 as a pivot point to adjust the planting depth. The planting depth adjustment member rotates together with the float support shaft 115. The rotation of the float support shaft 115 rotates the planting depth arms 120 that support each float 110, changing the vertical position of each float 110, i.e., the planting depth. This planting depth adjustment is performed based on a setting operation using a planting depth setting operation unit (e.g., a dial operation unit) provided on the operation unit 16.

[0079] As shown in Figure 5, the rice transplanter 1 is equipped with a control device 50 as a control unit. The control device 50 controls each unit of the rice transplanter 1 based on input signals from various sensors and the like equipped in the rice transplanter 1. The control device 50 is configured by connecting, via a bus or the like, a CPU (Central Processing Unit) as an arithmetic processing device that constitutes an arithmetic unit that executes various arithmetic processes and controls, a storage device that constitutes a storage unit such as a RAM (Random Access Memory) or a ROM (Read Only Memory), an input / output device (input / output circuit) that constitutes an input / output unit such as an input / output interface for data input / output, and peripheral circuits such as a clock circuit. The CPU of the control device 50 performs arithmetic processes according to various programs stored in the ROM or the like.

[0080] The control device 50 is configured to include, for example, a plurality of microcomputer units connected to each other so that they can communicate with each other via a controller area network (CAN). However, the configuration of the control device 50 is not particularly limited. The control device 50 is provided in a predetermined location in the rice transplanter 1, such as the machine frame 7.

[0081] 5, the rice transplanter 1 has, in addition to the float angle detection sensor 131 described above, an operation device 101, a phase detection sensor 102 as a phase detection unit, a vehicle speed sensor 103, a lift operation lever 104, and an accelerator pedal 105, all of which are electrically connected to the input device (input circuit) of the control device 50. The control device 50 receives input signals from these devices and sensors, and generates control signals based on the signals.

[0082] The operation device 101 is a device operated by an operator, and includes, for example, operation tools such as levers, switches, dials, and pedals provided on the operation unit 16. When the operation device 101 receives a predetermined operation, it outputs a signal to the control device 50 according to the operation content.

[0083] The phase detection sensor 102 is a sensor for detecting the phase of rotation of the rotary case 82. The phase detection sensor 102 is, for example, a proximity sensor (magnetic sensor) that detects the presence or absence of metal, and detects the phase of rotation of the rotary case 82 (hereinafter simply referred to as "phase") by detecting a protrusion provided on a rotating body such as a rotating shaft that is linked to a transmission mechanism provided inside the planting transmission case 81.

[0084] The phase of the rotary case 82 detected by the phase detection sensor 102 is the angular position of the rotation around the axis of the drive shaft 86 of the rotary case 82 relative to the planting transmission case 81. The control device 50 detects the phase of the rotary case 82 by receiving the detection signal input from the phase detection sensor 102. The control device 50 can detect the phase of the rotary case 82 as an angular position (amount of rotation) relative to a predetermined reference position (rotation angle = 0°).

[0085] The vehicle speed sensor 103 is a sensor for detecting the vehicle speed, which is the traveling speed of the traveling machine body 2. The vehicle speed sensor 103 detects the vehicle speed by detecting the rotation speed of a rotating body such as a shaft in a drive device related to the traveling of the machine body, for example.

[0086] The control device 50 receives an input of a detection signal from the vehicle speed sensor 103 and detects the vehicle speed. The control device 50 controls the vehicle speed based on the detection signal from the vehicle speed sensor 103. The control device 50 receives an input of a detection signal regarding the amount of operation of a gear shift operating member such as a gear shift lever or a gear shift pedal, generates control information based on the detection signal, and controls the vehicle speed based on the generated control information.

[0087] The lifting operation lever 104 is an operation unit for lifting and lowering the planting device 3. Based on an operation signal from the lifting operation lever 104, the control device 50 controls the operation of the lifting cylinder 65 (see FIG. 1) via a control valve or the like (not shown), thereby lifting and lowering the planting device 3. For example, by tilting the lifting operation lever 104 in one direction, the lifting cylinder 65 extends and the planting device 3 descends, and by tilting the lifting operation lever 104 in the other direction, the lifting cylinder 65 contracts and the planting device 3 ascends. Note that the operation unit for lifting and lowering the planting device 3 may be configured with an operation tool other than a lever, such as a configuration provided with switches (lift switch, lower switch) for performing each operation to lift and lower the planting device 3.

[0088] Accelerator pedal 105 is an example of an accelerator operation unit for adjusting the rotation speed of engine 20, and is provided on floor 13 in operation unit 16 (see FIG. 2).

[0089] As shown in FIG. 5 , a first inverter 46 for controlling the motor generator 41 and a second inverter 47 for controlling the electric motor 42 are connected to the control device 50. The control device 50 controls the first inverter 46 and the second inverter 47. That is, the first inverter 46 controls the operation of the motor generator 41 under the control of the control device 50, and the second inverter 47 controls the operation of the electric motor 42 under the control of the control device 50. The control device 50 obtains information about the motor generator 41 via the first inverter 46 and obtains information about the electric motor 42 via the second inverter 47. The control device 50 controls the operation of various relays included in a junction box 48.

[0090] The control device 50 controls the electric motor 42, which serves as the drive source for the planting device 3, and basically controls the rotation speed of the electric motor 42 in accordance with the amount of operation of a speed change operating member such as a speed change lever. In other words, when the control device 50 controls the drive of the electric motor 42, the rotational power input from the electric motor 42 to the drive shaft 86 of the rotary case 82 in the power transmission system of the planting device 3 changes speed together with the vehicle speed in accordance with the amount of operation of the speed change operating member.

[0091] Therefore, the rotation speed of the rotary case 82, i.e., the planting speed of the planting device 3, changes depending on the vehicle speed. In detail, the faster the vehicle speed, the shorter the rotation period of the rotary case 82, and the slower the vehicle speed, the longer the rotation period of the rotary case 82. This maintains a constant spacing between plants regardless of the traveling speed of the traveling body 2.

[0092] In this way, the control device 50 issues a rotation instruction (rotation speed instruction) according to the vehicle speed to the electric motor 42. With regard to the spacing between rows, the rotation speed of the rotary case 82 can be changed by controlling the rotation speed of the electric motor 42 relative to the vehicle speed, thereby changing the spacing between rows.

[0093] As described above, the rice transplanter 1 comprises a planting device 3 having a rotary case 82 that supports the planting claws 92 and is rotatably arranged, an electric motor 42 for driving the rotary case 82 to rotate, a phase detection sensor 102 for detecting the phase of the rotary case 82, and a control device 50.

[0094] The control device 50 controls the electric motor 42 based on the phase of the rotary case 82 detected by the phase detection sensor 102 in relation to the operation control of the rotary case 82 .

[0095] The control device 50 controls the rotary case 82 to stop rotation by controlling the drive of the electric motor 42, thereby stopping the rotation of the rotary case 82 at a predetermined phase where the planting claws 92 move away from the field surface (paddy field surface 6). Hereinafter, with regard to the control of stopping the rotary case 82 by the control device 50, the phase where the rotation of the rotary case 82 stops is referred to as the "upper stop position."

[0096] FIG. 6 shows the rotary case 82 in the upper stop position. When the rotary case 82 is in the upper stop position, its longitudinal direction is approximately horizontal. When the rotary case 82 is in the upper stop position, the front and rear planting claw devices 90 position the planting claws 92 in the vertically intermediate portion of their rotation range, which forms a loop-shaped trajectory. The upper stop position of the rotary case 82 is set to prevent the planting claws 92 from contacting the ground when the planting device 3 is lowered or from interfering with the seedling carrier 73 when the seedling carrier 73 is fed laterally when the planting device 3 is in a drive-stopped state (when all rows are stopped), which could result in damage to the planting claws 92 or the seedling carrier 73. Furthermore, by stopping the rotary case 82 in the upper stop position, the planting claws 92 can be prevented from dragging in the soil of the field 5 when the planting device 3 is in the operating position.

[0097] 6, the upper stop position of the rotary case 82 is the phase of the rotary case 82 when one of the two planting claw devices 90 (front and rear) has its tip 92c positioned within a predetermined phase range C1 at the front and middle of the upper and lower parts of the trajectory A1. In other words, one rotation of the rotary case 82 corresponds to one rotation of the planting claws 92 of the planting claw device 90 along the trajectory A1, and the upper stop position of the rotary case 82 is the phase when one of the two planting claw devices 90 has its tip 92c of the planting claw 92 positioned within the phase range C1.

[0098] As shown in FIG. 6, for example, with respect to the upper stop position, if the lowest point on the locus A1 is set to a reference point P1 where the phase of the rotary case 82 (hereinafter referred to as the "rotary phase") is 0°, the phase range C1 corresponding to the upper stop position is set to a range of 240° to 300°. That is, for the points on the locus A1 shown in FIG. 6, point Pa, which defines the position of the start point of the phase range C1, corresponds to a rotary phase of 240°, and point Pb, which defines the position of the end point of the phase range C1, corresponds to a rotary phase of 300°. Note that, for the points on the locus A1, points P2, P3, and P4 correspond to points where the rotary phase is 90°, 180°, and 270°, respectively. FIG. 6 shows a state where the rotary phase is 290°.

[0099] Therefore, when using the example of angles in the locus A1 shown in Figure 6, the rotary phase in which one of the two planting claw devices 90 positions the tip 92c of the planting claw 92 within the phase range C1 is set to the ranges of 60° to 120° and 240° to 300°. These two ranges of rotary phases become the upper stop positions of the rotary case 82.

[0100] The control device 50 controls the rotary case 82 to stop based on the operation of the operating device 101. That is, the control device 50 controls the rotary case 82 to stop when the operating device 101 performs a predetermined stop operation to stop the drive of the planting device 3. When the operating device 101 performs a predetermined operation to stop the drive of the planting device 3, a signal is output from the operating device 101 to the control device 50. The control device 50 starts to execute the control device 82 to stop when the signal input from the operating device 101 is used as a trigger.

[0101] The operation of the operating device 101 to control the stop of the rotary case 82, that is, the stop operation of the operating device 101, is functionally equivalent to the operation of turning off the planting clutch using a planting clutch lever in a configuration that has a planting clutch for switching the connection / disconnection of rotational power in the power transmission path for the rotary case 82. Therefore, the stop operation of the operating device 101 can be assigned to the "off" operation of an existing planting clutch lever, for example.

[0102] The control device 50 performs stop control (hereinafter referred to as "planting section stop control") to stop the rotation of the rotary case 82 by moving the rotary case 82 to an upper stop position, which is a predetermined target phase set as the stop position of the rotary case 82 for the phase of the rotary case 82, and then performing upper stop control to stop the rotation of the rotary case 82.

[0103] As shown in graph G1 in Figure 9, in this embodiment, the control device 50 performs planting unit stop control by decelerating the motor rotation speed at a predetermined deceleration rate from a state in which the motor rotation speed is maintained at a constant value, and stopping the rotation of the rotary case 82. Graph G1 shows the change in the rotation speed command from the control device 50 to the electric motor 42.

[0104] In graph G1 shown in FIG. 9, the vertical axis represents the motor rotation speed [min^-1] (rpm). In graph G1, the horizontal axis represents the passage of time. In the upper stop control, the target phase value is a phase value corresponding to the upper stop position, and is set and stored in advance in a storage device or the like in the control device 50. The target phase value is set as a predetermined value within the range of, for example, 60° to 120°, or 240° to 300°. In graph G1, the intersection of the vertical axis and the horizontal axis represents a state where the motor rotation speed is 0, and the electric motor 42 is stopped, i.e., the rotary case 82 is stopped from rotating.

[0105] As shown in Figure 9, the planting unit stop control is initiated, for example, during planting work by the planting device 3, while the motor rotation speed is maintained at a constant rotation speed r1 corresponding to the vehicle speed (see section S0). That is, in section S0, the electric motor 42 rotates at a constant rotation speed r1 based on a rotation command corresponding to the vehicle speed from the control device 50. The end point of section S0, i.e., the control start time t1 of the planting unit stop control, is the timing when the stop operation of the operating device 101 is performed as a trigger to start the control.

[0106] When a stop operation is performed on the operating device 101, the control device 50 decelerates the motor rotation speed at a predetermined deceleration rate from the control start time t1 so that the rotation of the rotary case 82 stops at a preset target position, thereby stopping the rotation of the rotary case 82. In other words, the control device 50 decelerates the rotation of the rotary case 82 at a predetermined deceleration rate from the control start time t1 so that the rotation of the rotary case 82 stops when the actual difference, which is the difference between the target phase value and the phase value actually detected by the phase detection sensor 102, becomes zero.

[0107] [Torque reduction control] In the configuration in which the planting section stop control is performed to stop the rotary case 82 at the upper stop position as described above, the control device 50 is basically configured to perform torque reduction control to make the torque limit value (torque limit value) of the electric motor 42 when the rotary case 82 is stopped at the upper stop position smaller than the limit value in other states of the rice transplanter 1.

[0108] The control device 50 limits the current flowing from the second inverter 47 to the electric motor 42, thereby limiting the torque generated by the electric motor 42. By limiting the torque of the electric motor 42, the torque generated by the electric motor 42 is limited by limiting the current, even if the load on the electric motor 42 changes, as shown in graph G01 in Fig. 10. In the graph shown in Fig. 10, the horizontal axis represents time, and the vertical axis represents the torque of the electric motor 42 [N·m (Newton·meter)].

[0109] Graph G01 in Fig. 10 shows an example in which the torque limit value is limited to a predetermined first torque limit value T1. As the load on the electric motor 42 changes, a situation may arise in which the torque exceeds the first torque limit value T1, as shown in graph G03 indicated by the two-dot chain line, for example. However, by limiting the torque, the torque is limited so that it does not exceed the first torque limit value T1. In other words, the torque limit represented by graph G01 in Fig. 10 is a limit function that limits the torque to the first torque limit value T1.

[0110] In this control mode in which torque is limited for the electric motor 42, the control device 50 performs torque reduction control based on predetermined conditions to reduce the torque limit value for the electric motor 42 when the rotary case 82 is in a rotation-stopped state to less than the first torque limit value T1. Fig. 10 shows an example in which the torque limit value for the electric motor 42 is changed from the first torque limit value T1 in graph G01 to a second torque limit value T2 that is smaller than the first torque limit value T1 as graph G02 (see arrow D1).

[0111] The torque reduction control is not limited to control of changing the torque limit value from the first torque limit value T1 to a smaller second torque limit value T2, but may also be control of changing the torque limit value from the first torque limit value T1 to 0 (zero), that is, control of stopping output to the electric motor 42. In this way, making the torque limit value of the electric motor 42 smaller than the limit value (first torque limit value T1) in another state of the rice transplanter 1 includes setting the torque limit value to 0. The first torque limit value T1 and the second torque limit value T2 are set and stored in advance in a storage device or the like in the control device 50.

[0112] (First control mode) The control device 50 performs the following control as a first control mode of the torque reduction control: That is, the control device 50 performs torque reduction control to reduce the torque limit value of the electric motor 42 while the traveling machine body 2 is stopped relative to the torque limit value while the traveling machine body 2 is traveling.

[0113] In the first control mode, the torque limit value while the traveling machine body 2 is traveling corresponds to the first torque limit value T1 of the graph G01 shown in Fig. 10. That is, according to the graph shown in Fig. 10, the control device 50 controls the torque limit value of the electric motor 42 while the traveling machine body 2 is stopped so that it changes from the first torque limit value T1 while traveling to the second torque limit value T2 of the graph G02.

[0114] In the configuration in which rotation instructions are given to the electric motor 42 according to the vehicle speed as described above, the rotary case 82 is in a stopped state of rotation while the traveling vehicle body 2 is stopped. Therefore, as torque reduction control, the control device 50 performs control to change the torque limit value of the electric motor 42 from the first torque limit value T1 to the second torque limit value T2 on the condition that the traveling vehicle body 2 has stopped traveling while the traveling vehicle body 2 is traveling. Note that as torque reduction control, instead of changing the torque limit value to the second torque limit value T2, control to stop output from the electric motor 42 may be performed.

[0115] The control device 50 detects the stoppage of the traveling machine body 2, for example, based on the input of a detection signal from the vehicle speed sensor 103. The stopped traveling state of the traveling machine body 2 detected by the control device 50 is not limited to the stopped state of the rice transplanter 1, but may also be the almost stopped state (extremely slow speed state) of the rice transplanter 1. In other words, a state in which the vehicle speed is equal to or less than a predetermined threshold may be detected as the stopped traveling state of the traveling machine body 2. In this case, the threshold value for the vehicle speed is set to a value within the range of 0.2 to 0.5 [m / s], for example.

[0116] There is no limitation on the method for detecting the stopped state of the traveling machine body 2. The stopped state of the traveling machine body 2 may be detected, for example, by detecting the operation of a drive mechanism such as a transmission in a traveling drive system that transmits power from the engine 20.

[0117] (Second control mode) The control device 50 performs the following control as a second control mode of the torque reduction control: That is, the control device 50 performs torque reduction control to reduce the torque limit value of the electric motor 42 when the planting device 3 is in the non-working position relative to the torque limit value when the planting device 3 is in the working position.

[0118] In the second control mode, the torque limit value when the planting device 3 is in the working position corresponds to the first torque limit value T1 of graph G01 shown in Fig. 10. That is, according to the graph shown in Fig. 10, the control device 50 controls the torque limit value of the electric motor 42 when the planting device 3 is in the non-working position so as to change from the first torque limit value T1 when the planting device 3 is in the working position to the second torque limit value T2 of graph G02.

[0119] When the planting device 3 is in the non-working position, the rotary case 82 is stopped from rotating. Therefore, as torque reduction control, the control device 50 controls the torque limit value of the electric motor 42 from the first torque limit value T1 to the second torque limit value T2 on the condition that it has detected that the planting device 3 is in the non-working position.

[0120] The control device 50 detects whether the planting device 3 is in the working position or the non-working position, for example, based on the input of a detection signal from the float angle detection sensor 131. That is, the control device 50 detects a state in which the float angle detection sensor 131 detects the ground contact mode of the planting device 3 as a state in which the planting device 3 is in the working position, and detects a state in which the float angle detection sensor 131 detects the non-ground contact mode of the planting device 3 as a state in which the planting device 3 is in the non-working position. In this way, the float angle detection sensor 131 functions as a position detector for the elevation and lowering of the planting device 3.

[0121] The method for detecting whether the planting device 3 is in the non-working position is not limited. For example, the detection of whether the planting device 3 is in the non-working position may be performed by detecting the operating state or angle state of the lifting cylinder 65.

[0122] (Third control mode) The control device 50 performs the following control as a third control mode of the torque reduction control: That is, the control device 50 performs torque reduction control to reduce the torque limit value of the electric motor 42 while the traveling body 2 is stopped relative to the torque limit value during the lifting and lowering operation of the planting device 3.

[0123] In the third control mode, the torque limit value during the lifting and lowering operation of the planting device 3 corresponds to the first torque limit value T1 of the graph G01 shown in Fig. 10. That is, according to the graph shown in Fig. 10, the control device 50 controls the torque limit value of the electric motor 42 while the planting device 3 is stopped from the first torque limit value T1 during the lifting and lowering operation to the second torque limit value T2 of the graph G02.

[0124] As torque reduction control, the control device 50 controls the torque limit value of the electric motor 42 from the first torque limit value T1 to the second torque limit value T2 on the condition that it detects that the traveling body 2 has stopped traveling during the lifting and lowering operation of the planting device 3. As with the first control mode, the traveling stopped state of the traveling body 2 detected by the control device 50 may be a state in which the rice transplanter 1 is approximately stopped. Furthermore, the method for detecting the traveling stopped state of the traveling body 2 is not limited.

[0125] (Fourth control mode) The control device 50 performs the following control as a fourth control mode of the torque reduction control. That is, the control device performs torque reduction control to reduce the torque limit value of the electric motor 42 relative to the torque limit value while the traveling vehicle body 2 is traveling, on the condition that it has detected that an external force has acted on the rotary case 82 while the traveling vehicle body 2 is stopped.

[0126] In the third control mode, the torque limit value while the traveling vehicle body 2 is traveling corresponds to the first torque limit value T1 of graph G01 shown in Fig. 10. That is, according to the graph shown in Fig. 10, when an external force acts on the rotary case 82 while the traveling vehicle is stopped, that is, when torque is applied to the rotary case 82 from the first torque limit value T1 while traveling, to the second torque limit value T2 of graph G02. Here, the external force acting on the rotary case 82 is related to torque, and is an external force mainly in the rotational direction of the rotary case 82.

[0127] As a torque reduction control, the control device 50 controls the torque limit value of the electric motor 42 from the first torque limit value T1 to the second torque limit value T2 on the condition that it detects that an external force has been applied that attempts to rotate the rotary case 82 while the traveling body 2 is stopped.

[0128] The control device 50 detects that an external torque has been applied to the rotary case 82, for example, by detecting that the rotary case 82 has rotated (the phase has changed) based on the input of a detection signal from the phase detection sensor 102.

[0129] There is no limitation on the method for detecting that an external torque has been applied to the rotary case 82. The detection of that an external torque has been applied to the rotary case 82 may be performed, for example, by providing a torque sensor on the rotary case 82 or the like.

[0130] (About canceling torque reduction control) Furthermore, when a predetermined condition is satisfied during the execution of torque reduction control performed by the various control modes as described above, the control device 50 cancels the torque reduction control and performs control to return the torque limit value of the electric motor 42 from the second torque limit value T2 to the first torque limit value T1.

[0131] The condition for canceling the torque reduction control is at least one of the following: detecting the start of travel of the traveling machine body 2 while the traveling machine body 2 is stopped (first condition); performing an operation to raise or lower the planting device 3 (second condition); and performing an operation to rotate the rotary case 82 (third condition). That is, the control device 50 cancels the torque reduction control when any one of the first to third conditions is satisfied during the torque reduction control.

[0132] Regarding the first condition, the control device 50 detects the start of traveling of the traveling machine body 2, for example, by detecting accelerator operation using the accelerator pedal 105, the main shift lever, etc. In other words, the control device 50 cancels the torque reduction control on the condition that the accelerator operation is performed during the torque reduction control.

[0133] Regarding the first condition, the control device 50 can also detect the start of traveling of the traveling machine body 2 by detecting that a vehicle speed has been generated based on the detection value of the vehicle speed sensor 103. In addition, the start of traveling of the traveling machine body 2 may be detected as the start of traveling when the detection value of the vehicle speed sensor 103 exceeds the threshold value related to the vehicle speed as described above.

[0134] Regarding the second condition, the control device 50 detects that the planting device 3 has been lifted or lowered by detecting the lifting or lowering operation of the planting device 3 using the lifting operation lever 104. That is, the control device 50 releases the torque reduction control on the condition that the planting device 3 has been lifted or lowered using the lifting operation lever 104 during the torque reduction control.

[0135] The second condition may be determined solely by lowering the planting device 3 using the lifting control lever 104. In this case, in the second control mode of the torque reduction control described above, for example, the lifting operation of the planting device 3 using the lifting control lever 104 may be detected as the planting device 3 being in the non-working position, and the torque limit value of the electric motor 42 may be reduced from the first torque limit value T1 when the planting device 3 is in the working position to the second torque limit value T2 when the planting device 3 is lowered. Then, the torque reduction control is released and the torque limit value is returned to the first torque limit value T1 when the planting device 3 is lowered as the second condition.

[0136] Regarding the third condition, the control device 50 detects that an operation to rotate the rotary case 82 has been performed by detecting the driving operation of the rotary case 82 by the operating device 101. That is, the control device 50 releases the torque reduction control on the condition that a predetermined driving operation to start driving the planting device 3 has been performed by the operating device 101 during the torque reduction control.

[0137] The operation of the operating device 101 to control the drive of the rotary case 82, that is, the drive operation of the operating device 101, is functionally equivalent to the operation of turning on the planting clutch using a planting clutch lever in a configuration that has a planting clutch for switching on / off the rotational power in the power transmission path for the rotary case 82. Therefore, the drive operation of the operating device 101 can be assigned to the "on" operation of an existing planting clutch lever, for example.

[0138] (An example of torque reduction control) An example of torque reduction control will be described with reference to the flowchart shown in Fig. 11. Fig. 11 is a flowchart showing an example of a control mode of torque reduction control and its release control.

[0139] The control described below is performed by the CPU of the control device 50 reading and executing a predetermined control program stored in a storage device such as a RAM. In this example, the torque reduction control will be described taking as an example a case where the control of the first control mode described above is performed.

[0140] 11, during planting work by the rice transplanter 1, the operator operates the operating device 101 to perform a stop operation to stop the driving of the planting device 3 (S10). As a result, the rotary case 82 stops at the upper stop position (S20). In this state, the control device 50 sets the torque limit value of the electric motor 42 (simply referred to as the "torque limit value" in the description of this example) to a first torque limit value T1.

[0141] Thereafter, the control device 50 determines whether the traveling machine body 2 has stopped traveling (S30). In step S30, the control device 50 maintains the torque limit value at the first torque limit value T1 as long as the traveling machine body 2 is traveling (S30, NO).

[0142] On the other hand, in step S30, if the control device 50 determines that the traveling machine body 2 has stopped traveling (S30, YES), it reduces the torque limit value from the first torque limit value T1 to the second torque limit value T2 (S40). Note that in step S40, instead of the control to reduce the torque limit value to the second torque limit value T2, control to stop the output of the electric motor 42 may be performed.

[0143] Thereafter, the control device 50 determines whether or not at least one of the first to third conditions for canceling the torque reduction control is satisfied (S50). In step S50, the control device 50 maintains the torque limit value at the second torque limit value T2 unless at least one of the first to third conditions is satisfied (S50, NO).

[0144] On the other hand, in step S60, if the control device 50 determines that at least one of the first to third conditions is satisfied (S50, YES), it returns the torque limit value from the second torque limit value T2 to the first torque limit value T1 (S60) and cancels the torque reduction control. That is, in step S60, the control device 50 cancels the torque reduction control in response to at least one of the accelerator operation, the lifting / lowering operation of the planting device 3, and the driving operation of the rotary case 82.

[0145] According to the rice transplanter 1 of this embodiment having the above-mentioned configuration, in a configuration in which the rotary case 82 is driven to rotate by the electric motor 42, safety can be improved when an operator attempts to manually rotate the rotary case 82 that is in a stopped state.

[0146] In the rice transplanter 1, an operator may attempt to manually rotate the rotary case 82 while the rice transplanter 1 is stopped in order to clear seedling jams in the planting device 3 or to perform maintenance on the rotary case 82 or the planting claw device 90. In such cases, the rotary case 82, which is stopped at the upper stop position, attempts to return to the upper stop position, which is the commanded position, due to the torque from the electric motor 42. Such automatic rotation of the rotary case 82 may be unexpected for the operator, potentially compromising safety.

[0147] Therefore, according to the torque reduction control performed by the control device 50 as described above, the torque limit value when the traveling machine body 2 is stopped is reduced relative to the torque limit value when traveling. This allows the worker to manually rotate the rotary case 82 by accessing the rotary case 82 or the planting claw device 90 to clear seedling jams, etc., and allows the rotary case 82 to be rotated with less force, and the rotation of the rotary case 82 returning to the upper stop position to be slowed. This improves worker safety. Furthermore, by stopping the output of the electric motor 42 instead of lowering the torque limit value, it is also possible to perform tasks such as clearing seedling jams with less force, thereby improving worker safety.

[0148] Regarding torque reduction control, according to the configuration in which control is performed to reduce the torque limit value of the electric motor 42 by detecting a stop of driving, as in the first and third control modes described above, it is possible to detect a state in which the torque limit value of the electric motor 42 is reduced by utilizing existing configurations such as the vehicle speed sensor 103, and therefore torque reduction control can be easily realized.

[0149] Similarly, with regard to torque reduction control, according to the configuration in which the control to reduce the torque limit value of the electric motor 42 is performed by detecting the state in which the planting device 3 is in a non-working position, as in the second control mode described above, it is possible to detect the state in which the torque limit value of the electric motor 42 is reduced by utilizing existing configurations such as the float angle detection sensor 131, and therefore torque reduction control can be easily realized.

[0150] Similarly, with regard to the torque reduction control, if the configuration is such that control is performed to reduce the torque limit value of the electric motor 42 on the condition that external torque is applied to the rotary case 82 while the vehicle is stopped, as in the fourth control mode described above, the torque limit value of the electric motor 42 can be reduced depending on the situation in which the stopped rotary case 82 is actually being rotated manually, etc. This effectively improves the safety of the operator.

[0151] The control device 50 is also configured to perform control to cancel the torque reduction control on the condition that at least one of the accelerator operation, the lifting / lowering operation of the planting device 3, and the driving operation of the rotary case 82 has been performed. With this configuration, the reduced state of the torque limit value of the electric motor 42 can be canceled at an appropriate timing depending on the traveling state of the traveling body 2 and the operating state of the planting device 3. This makes it possible to automatically switch the torque limit value of the electric motor 42 depending on the traveling state and working state of the rice transplanter 1 while performing the stop control of the upper part of the rotary case 82, thereby improving safety.

[0152] The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment. Therefore, even if it is not the above-described embodiment, various modifications are possible depending on the design, etc., as long as they do not deviate from the technical idea of ​​the present invention. Furthermore, the effects described in this disclosure are merely examples and are not limited, and other effects may also be obtained.

[0153] In the above-described embodiment, the control device 50 is configured to execute planting unit stop control using the input of a signal resulting from the stop operation of the operating device 101 as a trigger, but the trigger for starting the planting unit stop control is not particularly limited. For example, if the rice transplanter 1 is configured to enable autonomous travel based on position information received from a positioning satellite, an input signal from a controller of a positioning unit (antenna unit) that receives radio waves from the positioning satellite to measure the position of the rice transplanter 1 may be used as a trigger for starting the planting unit stop control.

[0154] That is, with regard to the planting unit stop control, the instruction unit that instructs the driving of the electric motor 42 of the planting device 3 includes an operating device 101 such as a lever arranged on the operating unit 16, as well as a configuration that can input an instruction signal to a configuration (control device 50) that controls the driving of the electric motor 42, for example, when the rice transplanter 1 is running autonomously.

[0155] Similarly, with regard to the third condition for releasing the torque reduction control described above, in addition to the operation of driving the rotary case 82 by the operating device 101, the instruction unit that instructs the driving of the electric motor 42 of the planting device 3 includes a configuration that can input an instruction signal to a configuration (control device 50) that controls the driving of the electric motor 42, for example, when the rice transplanter 1 is running autonomously. [Explanation of symbols]

[0156] 1. Rice transplanter (transplanter) 2 Running body 3 Planting device (planting section) 42 Electric motor 50 Control device (control unit) 82 Rotary case (planting rotor) 92 Planting Claw 101 Operating device 102 Phase detection sensor 103 Vehicle speed sensor 104 Lifting control lever 105 Accelerator pedal 131 Float angle detection sensor

Claims

1. A running body and A planting unit supported by the traveling machine body, supporting the planting claws and having a rotatably provided planting rotor; An electric motor for rotating the planting rotor; a control unit that controls the electric motor, The control unit performs torque reduction control to reduce a limit value of the torque of the electric motor while the traveling machine body is stopped relative to the limit value while the traveling machine body is traveling. transplant machine.

2. A running body and A planting unit supported by the traveling machine body, supporting the planting claws and having a rotatably provided planting rotor; An electric motor for rotating the planting rotor; a control unit that controls the electric motor, The control unit performs torque reduction control to reduce a limit value of the torque of the electric motor when the planting unit is in a non-working position relative to the limit value when the planting unit is in a working position. transplant machine.

3. A running body and A planting unit supported by the traveling machine body, supporting the planting claws and having a rotatably provided planting rotor; An electric motor for rotating the planting rotor; a control unit that controls the electric motor, The control unit performs torque reduction control to reduce the limit value of the torque of the electric motor while the traveling machine body is stopped relative to the limit value during the lifting and lowering operation of the planting unit. transplant machine.

4. A running body and A planting unit supported by the traveling machine body, supporting the planting claws and having a rotatably provided planting rotor; An electric motor for rotating the planting rotor; a control unit that controls the electric motor, The control unit performs torque reduction control to reduce the torque limit value of the electric motor relative to the limit value while the traveling machine body is traveling, on the condition that it detects that an external force has acted on the planting rotor while the traveling machine body is stopped. transplant machine.

5. The control unit releases the torque reduction control under at least one of the conditions that the start of travel of the traveling machine body is detected while the traveling machine body is stopped, that an operation to raise or lower the planting unit is performed, and that an operation to rotate the planting rotor is performed. A transplanter according to any one of claims 1 to 4.

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