Work vehicle

Abstract

To provide a work vehicle which can suppress decrease in work accuracy when a vehicle body is slipped.SOLUTION: A work vehicle according to one aspect of the embodiment includes: a vehicle body having a drive wheel; a planting device attached to the vehicle body; a drive source for generating power for rotating the drive wheel; a clutch for switching a transmission state of the power generated by the drive source to the planting device; a motor for driving the planting device; and a control device for controlling the clutch and the motor. When the slippage of the vehicle body is not detected, the control device turns the transmission state into ON state and drives the planting device by the power generated by the drive source. When the slippage of the vehicle body is detected, the control device turns the transmission state into OFF state and drives the planting device by the power generated by the motor.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] Conventionally, there is known a work vehicle that outputs power generated by an engine to a traveling device and a planting device that is a working unit via a transmission case (see, for example, Patent Document 1). The work vehicle can drive the planting device in accordance with the vehicle speed of the traveling vehicle body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a field where the work vehicle performs work, when the traveling vehicle body slips, in the conventional work vehicle, for example, the interval between the seedlings transplanted in the field by the planting device may deviate from the interval when the traveling vehicle body is not slipping. That is, in the conventional work vehicle, when the traveling vehicle body slips, the working accuracy may decrease.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a work vehicle that suppresses a decrease in working accuracy even when the traveling vehicle body slips.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, a work vehicle (1) according to an aspect of the embodiment includes a traveling vehicle body (2) having drive wheels (10, 11), a planting device (55) attached to the traveling vehicle body (2), a drive source (30) that generates power for rotating the drive wheels (10, 11), a clutch (27a) that switches the transmission state of the power generated by the drive source (30) to the planting device (55), a motor (110) capable of driving the planting device (55), and a control device (100) that controls the clutch (27a) and the motor (110). When slip of the traveling vehicle body (2) is not detected, the control device (100) sets the transmission state to the engaged state and drives the planting device (55) with the power generated by the drive source (30). When slip of the traveling vehicle body (2) is detected, the control device (100) sets the transmission state to the disengaged state and drives the planting device (55) with the power generated by the motor (110).

Effect of the Invention

[0007] According to an aspect of the embodiment, the work vehicle can suppress a decrease in work accuracy when the traveling vehicle body slips.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

DETAILED DESCRIPTION OF THE INVENTION

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

[0010] In the following description, the front-rear direction is the traveling direction when the work vehicle 1 travels straight, and the front side in the traveling direction is defined as "front" and the rear side as "rear". The traveling direction of the work vehicle 1 is the direction from the driver's seat 41 toward the steering wheel 35 (steering device) when traveling straight (see FIGS. 1 and 2).

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

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

[0013] In the embodiment, the work vehicle 1 will be described as a riding-type seedling transplanter 1 that includes a seedling planting unit 4 as a working device and receives seedlings in the field. As shown in FIGS. 1 and 2, the seedling transplanter 1 includes a liftable seedling planting unit 4 that plants seedlings in the field via a lift link mechanism 3 on the rear side of the traveling vehicle body 2.

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

[0015] The traveling body 2 is a four-wheel drive vehicle equipped with left and right front wheels 10 and rear wheels 11 which are wheels and drive wheels. On the front side of the main frame 15 that constitutes the body skeleton of the traveling body 2, there are provided a transmission case 13 that transmits power to the seedling planting unit 4 and other components, and a hydraulic continuously variable transmission 14 that outputs the rotation generated by the engine 30 to the transmission case 13.

[0016] The engine 30 generates power to rotate the front wheels 10 and the rear wheels 11. Further, the power generated by the engine 30 is transmitted to the seedling planting unit 4 via a planting clutch 27a described later, and drives the seedling planting unit 4.

[0017] The continuously variable transmission 14 is a hydrostatic continuously variable transmission called a so-called HST (Hydro Static Transmission). Hereinafter, the case where the continuously variable transmission is the HST 14 will be described.

[0018] Inside the transmission case 13, there is provided a sub-transmission mechanism 16 that switches the traveling mode of the traveling body 2 during road travel in high speed mode, during seedling planting in low speed mode, etc. Front wheel final cases 10a are provided on the left and right sides of the transmission case 13, and the front wheels 10 are attached to left and right front axles 10b that project outward from front wheel support portions capable of changing the steering direction of the left and right front wheel final cases 10a.

[0019] Also, on the rear side of the main frame 15, rear wheel gear cases 11a are attached to both the left and right sides of a rear frame 22 (see FIG. 2) provided in the lateral direction, and the rear wheels 11 are respectively attached to left and right rear axles 11b that project outward from the rear wheel gear cases 11a.

[0020] In addition, on the upper part of the rear frame 22, left and right link support frames 23 for supporting the lifting link mechanism 3 project upward. On the lower sides of the left and right link support frames 23 and between the left and right, a pair of left and right lower link arms 24 are provided. Between the left and right lower link arms 24, a lifting cylinder 25 that operates hydraulically is provided.

[0021] Above the lifting cylinder 25, an upper link arm 26 is provided, and the lifting link mechanism 3, which is a parallel link mechanism, is configured. Note that one end of each of the left and right lower link arms 24, the lifting cylinder 25, and the other end side of the upper link arm 26, which are each connected to the traveling vehicle body 2 side, are attached to the front part of the seedling planting part 4.

[0022] Also, an engine 30 is mounted on the main frame 15. The rotational power of the engine 30 is transmitted to the transmission case 13 via the belt transmission device 21 and the HST 14. The rotational power transmitted to the transmission case 13 is shifted by the sub-shifting mechanism 16 in the transmission case 13 and then divided into traveling power and externally extracted power. That is, the traveling power output from the transmission case 13 is transmitted to the front wheels 10 and the rear wheels 11.

[0023] Also, the externally extracted power taken out from the rotational power transmitted to the transmission case 13 is transmitted to the planting clutch case 27 provided at the rear part of the traveling vehicle body 2. Then, the externally extracted power is transmitted from the planting clutch case 27 to the seedling planting part 4 via the first planting transmission shaft 67 and the planting clutch 27a (see FIG. 4).

[0024] Also, the rotational power of the engine 30 is transmitted to a hydraulic pump (not shown). The hydraulic pressure generated by the hydraulic pump is supplied to the HST 14, the power steering mechanism 88 (see FIG. 4) of the handle 35, the lifting cylinder 25, and the like.

[0025] At the rear of the transmission case 13, left and right drive shafts 42 are provided. The rotational power from the engine 30 is transmitted to the left and right rear wheel gear cases 11a via the transmission case 13 and the drive shafts 42.

[0026] Note that a side clutch 44 (see FIG. 4) for engaging and disengaging the power transmission to the left and right drive shafts 42 is arranged on the upstream side in the transmission direction from the left and right drive shafts 42. As shown in FIG. 1, a side clutch pedal 43a for engaging and disengaging the left and right side clutches 44 is provided at the lower front side of the driver's seat 41 and on one side of the left and right.

[0027] When the side clutch pedal 43a on the inner side of the turn is depressed to disengage the side clutch 44 and then the steering wheel 35 is operated to perform a turning drive, the driving rotation of the rear wheel 11 on the inner side of the turn can be completely blocked.

[0028] At the upper front side of the traveling vehicle body 2, a bonnet 39 with an operation panel 38 for operating each part arranged at the upper part is provided. A monitor 86 (see FIG. 4) and the like are provided on the operation panel 38.

[0029] In addition, on the bonnet 39, a steering wheel 35 for steering the traveling vehicle body 2, a shift operation lever 36 for operating the HST 14 and the seedling planting part 4, a sub-shift operation lever 37 for operating the sub-transmission mechanism 16, and the like are provided.

[0030] In addition, an openable and closable front cover 40 is provided on the front side of the bonnet 39. Inside the front cover 40, a fuel tank, a battery, and an interlocking mechanism for rotating the lower sides of the left and right front wheels 10 and the left and right front wheel final cases 10a in response to the steering of the steering wheel 35 are provided. The front wheels 10 are, for example, steering wheels that steer in response to the steering of the steering wheel 35.

[0031] Behind the bonnet 39 and above the engine 30, an engine cover 30a that covers the upper and side portions of the engine 30 is provided, and a driver's seat 41 on which the operator sits is provided on the upper part of the engine cover 30a.

[0032] A fertilizer applicator 5 is provided on the rear side of the driver's seat 41 and on the rear end side of the main frame 15. The power of the fertilizer applicator 5 is transmitted by a fertilizer transmission mechanism provided so as to face the fertilizer applicator 5 from one side of the left and right rear wheel gear cases 11a.

[0033] On both the left and right sides at the lower parts of the engine cover 30a and the bonnet 39, substantially horizontal floor steps 33 are formed. As shown in FIG. 2, the floor steps 33 are partially lattice-shaped. For example, even if mud adhering to, for example, the shoes of the operator walking on the floor steps 33 falls, the fallen mud and the like fall onto the field.

[0034] Also, as shown in FIG. 2, a rear step 330 is connected to the rear of the floor step 33. It is preferable that the surface of the rear step 330 is subjected to an anti-slip process in which, for example, a plurality of protrusion patterns are formed so that the feet are less likely to slip during work.

[0035] Also, on the front side of the traveling vehicle body 2 and on both the left and right sides, a spare seedling frame 50 for arranging a plurality of spare seedling placing tables 52 at intervals in the vertical direction on the seedling frame support 51 is provided respectively, and work materials such as seedlings and fertilizer bags to be replenished to the seedling planting part 4 can be placed.

[0036] Also, at the rear end part of the lift link mechanism 3, a seedling tank 53 for loading seedlings to be planted in the field is mounted together with a sliding mechanism for sliding in the left - right direction. In the seedling tank 53, long seedling partition fences 54 in the vertical direction are respectively arranged at predetermined intervals in the left - right direction. Below the seedling tank 53, a seedling planting device 55 (planting device) for scraping the loaded seedlings and planting them in the field is arranged.

[0037] The seedling planting device 55 is configured to plant simultaneously in the same number of rows as the number of planting operation rows partitioned by the seedling partition fence 54, that is, eight rows at the same time. Four planting transmission cases 56 are arranged at intervals below the seedling tank 53 in the seedling planting device 55. Mounted on the left and right sides of each planting transmission case 56 are planting rotaries 57 that rotate to pick up seedlings by the planting rods 58 and plant them in the field.

[0038] When the planting clutch 27a is engaged, in the seedling planting unit 4, the transmission state of the power generated by the engine 30 becomes the on state, and the externally extracted power taken out from the transmission case 13 is transmitted to the seedling planting device 55. On the other hand, when the planting clutch 27a is disengaged (not engaged), in the seedling planting unit 4, the transmission state of the power generated by the engine 30 becomes the off state, and the externally extracted power taken out from the transmission case 13 is not transmitted to the seedling planting device 55.

[0039] Specifically, when the planting clutch 27a is engaged, the externally extracted power taken out from the transmission case 13 is transmitted to the seedling planting device 55 by the first planting transmission shaft 67 (first drive shaft) as shown in FIG. 3. That is, the first planting transmission shaft 67 transmits the power generated by the engine 30 to the seedling planting device 55. FIG. 3 is a schematic diagram showing a part of the seedling planting device 55.

[0040] The first planting transmission shaft 67 is connected so as to be able to transmit power to the power transmission mechanism 68 of the seedling planting device 55. The power transmission mechanism 68 is configured to transmit power to the planting rotary 57. The power transmission mechanism 68 includes gears, rotating shafts, and belt mechanisms, etc.

[0041] In addition, the seedling planting device 55 can be driven by a planting motor 110 (motor). Specifically, the power generated by the planting motor 110 is transmitted to the seedling planting device 55 by a second planting transmission shaft 111 (second drive shaft). The second planting transmission shaft 111 is connected to the power transmission mechanism 68 so as to be able to transmit power thereto. That is, the second planting transmission shaft 111 transmits the power generated by the planting motor 110 to the seedling planting device 55. The first planting transmission shaft 67 and the second planting transmission shaft 111 are connected to the power transmission mechanism 68 and are configured to transmit power to the seedling planting device 55.

[0042] Returning to FIGS. 1 and 2, in the fertilizer application device 5, a fertilizer application hopper 70 (fertilizer tank) in which fertilizer is stored is partitioned into the same number as the number of working rows of the seedling planting section 4 (in the example shown in FIG. 2, for 8 rows). Note that since the fertilizer application hopper 70 for 8 rows is long in the left-right direction, the convenience of fertilizer input and attachment / detachment is reduced. Thus, a so-called side fertilizer application structure in which those partitioned into 4 rows each are arranged side by side may be used.

[0043] Below the fertilizer application hopper 70, a feeding device 71 having a feeding section for supplying a set amount of fertilizer is provided for each row. The feeding section is driven by a feeding motor 71a. For example, the feeding section rotates by the feeding motor 71a. The feeding section has a recess capable of accommodating fertilizer. When the recess faces upward, fertilizer enters from the fertilizer application hopper 70, and when it faces downward, the fertilizer is discharged downward. By rotating the feeding section by the feeding motor 71a, fertilizer is discharged from the fertilizer application hopper 70.

[0044] Below the feeding device 71, a ventilation duct 72 through which a conveying wind for moving fertilizer passes is provided in the left-right direction. Below the feeding device 71, a fertilizer application hose 73 for guiding fertilizer to the vicinity of the seedling planting position of the seedling planting section 4 is provided. Further, at one end of the ventilation duct 72, a blower 74 that operates by a blower electric motor 76 to generate a conveying wind is provided.

[0045] As shown in FIGS. 1 and 2, below the seedling planting section 4, a center float 62C that contacts the field surface and slides, and two left and right side floats 62L and 62R are provided so as to be rotatable about an axis. Note that the center float 62C and the left and right side floats 62L and 62R may be collectively referred to as the float 62.

[0046] Also, below the seedling planting section 4 and on the front side of the float 62, a leveling rotor 63 for leveling the unevenness of the field surface is provided. Power is transmitted to the leveling rotor 63 from the rear wheel gear case 11a on the left and right other sides via a rotor transmission shaft 63a.

[0047] As shown in FIG. 1, on both the left and right sides of the seedling planting section 4, line markers 65 are provided, with either the left or the right side contacting the field surface to form a groove as a guide for traveling in the next working strip (next process). When either the left or right side of the left and right line markers 65 contacts the ground, the other side is spaced upward. When the seedling planting section 4 is lifted during turning, both the left and right sides are spaced upward. When the seedling planting section 4 descends after turning, one side is spaced upward and the other side contacts the ground.

[0048] As shown in FIGS. 1 and 2, at the left and right center portions of the traveling vehicle body 2 and in front of the bonnet 39, a center mascot 66 that is long in the vertical direction is provided. By aligning the center mascot 66 with the groove formed in the field by the left and right line markers 65, it becomes possible to travel in accordance with the working position of the immediately preceding working strip, improving the working accuracy and preventing the occurrence of non-working.

[0049] Depending on the soil quality of the field, the guide lines formed by the left and right line markers 65 may be buried immediately, and the straight-ahead guide may disappear. In such a case, it is advisable to use the left and right side markers 19 provided in front of the left and right line markers 65. That is, by moving the left and right side markers 19 outward and positioning the side markers 19 above the planted seedlings, it becomes possible to perform a planting operation in accordance with the planting of the seedlings in the previous working strip.

[0050] Further, as shown in FIG. 1, the seedling transplanter 1 is provided with a position detection device 150. The position detection device 150 detects the current position and orientation of the seedling transplanter 1. That is, the position detection device 150 detects information regarding the position and orientation of the traveling vehicle body 2. The position detection device 150 includes, for example, an orientation sensor and positioning means such as GPS (Global Positioning System) or GNSS (Global Navigation Satellite System). The position detection device 150 may be constituted by a plurality of devices. The position detection device 150 may include a camera and an ultrasonic sensor, and may acquire the turning position in the field and detect the distance to the turning position.

[0051] For example, the position detection device 150 receives positioning information from the positioning means, creates current position information and orientation information of the traveling vehicle body 2 based on the received positioning information, and detects the current position and orientation. The position detection device 150 is attached to, for example, the attachment stay 59 and disposed above the traveling vehicle body 2.

[0052] The straight-ahead control program and the turning control program created based on the position information by the position detection device 150 are stored in different locations from each other. The straight-ahead control program is stored, for example, in the straight-ahead control ECU (Electronic Control Unit) 100a in the position detection device 150, and the turning control program is stored, for example, in the turning control ECU 100b housed in the bonnet 39. Note that the straight-ahead control ECU 100a and the turning control ECU 100b are included in the control device 100 (see FIG. 4) described later. The straight-ahead control ECU 100a and the turning control ECU 100b may be stored in the same ECU.

[0053] Next, the control system of the seedling transplanter 1 will be described with reference to FIG. 4. FIG. 4 is a block diagram showing a control system centered on the control device 100 of the seedling transplanter 1. The seedling transplanter 1 is capable of controlling each part by electronic control and includes a control device (hereinafter referred to as a controller) 100 for controlling each part.

[0054] The controller 100 is provided with a processing unit having a CPU (Central Processing Unit) and the like, a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an input / output unit, and these are connected to each other and can transfer signals to each other. A computer program for controlling the seedling transplanter 1 and the like is stored in the storage unit. The controller 100 exhibits each function by reading a computer program and the like stored in the storage unit.

[0055] To the controller 100, for example, as actuators, a throttle motor 80, hydraulic control valves 81, 82, a planting clutch operating solenoid 83, and a side clutch operating solenoid 84 are connected. Further, an HST motor 85, a wire drawing marker lifting motor 87, a steering motor 95 (steering motor), a differential lock switching motor 96, a planting motor 110, a feeding motor 71a, and the like are connected to the controller 100.

[0056] The throttle motor 80 increases or decreases the rotational speed of the output shaft of the engine 30 by operating a throttle that adjusts the intake air amount of the engine 30. The hydraulic control valve 81 controls the telescopic operation of the lifting cylinder 25. The hydraulic control valve 82 controls the power steering mechanism 88. The power steering mechanism 88 changes the direction of the front wheels 10 which are the steering wheels of the traveling vehicle body 2. The planting clutch operating solenoid 83 operates the planting clutch 27a. That is, the controller 100 controls the planting clutch 27a by controlling the planting clutch operating solenoid 83.

[0057] The side clutch operating solenoid 84 operates a side clutch 44 that switches the power transmission state to the rear wheels 11 (see FIG. 1). The side clutches 44 are provided on the left and right rear wheels 11 respectively, and two side clutch operating solenoids 84 are provided corresponding to each side clutch 44.

[0058] The HST motor 85 changes the tilt angle of the swash plate of the HST 14 by changing the rotation angle of the trunnion of the HST 14. The marking marker lifting motor 87 raises and lowers the marking marker 65.

[0059] The steering motor 95 rotates the steering wheel 35. The steering motor 95 is a motor that drives the steering wheel 35 to adjust the steering amount (steering angle) of the front wheels 10 (see FIG. 1) when the traveling vehicle body 2 executes automatic straight running.

[0060] The differential lock switching motor 96 is a motor that switches the operation and the stop of the differential lock mechanism 97 (hereinafter referred to as the differential lock mechanism) that rotates the left and right traveling wheels, specifically, the left and right front wheels 10, at the same rotational speed. When the differential lock mechanism 97 is in the engaged state, the left and right traveling wheels rotate at the same rotational speed.

[0061] The planting motor 110 drives the seedling planting device 55 via the second planting transmission shaft 111. Specifically, the planting motor 110 rotates the planting rotor 57. Note that the planting motor 110 functions as a generator when the transmission state of the power generated by the engine 30 is in the engaged state, that is, when the planting clutch 27a is engaged. Specifically, the planting motor 110 generates electricity when the externally extracted power taken out from the transmission case 13 is transmitted via the power transmission mechanism 68 and the second planting transmission shaft 111.

[0062] The planting motor 110 is supplied with power from the storage battery 112 (see FIG. 3). Further, the power generated by the planting motor 110 is supplied to the storage battery 112. That is, the storage battery 112 is charged by the power generation by the planting motor 110. The storage battery 112 is, for example, a lithium ion battery, a nickel hydrogen battery, or the like.

[0063] The feeding motor 71a drives a feeding unit that discharges fertilizer from the fertilizer hopper 70 by a set amount below the feeding device 71. The feeding motor 71a is supplied with power from the storage battery 112, for example.

[0064] The controller 100 is connected with a rotation speed sensor 90, a steering amount sensor 91, an inclination sensor 92, etc., which are detection devices. Two rotation speed sensors 90 are provided corresponding to the left and right rear wheels 11 to detect the rotation speeds of the left and right rear wheels 11 respectively. Note that the rotation speed sensors 90 may also detect the rotation speeds of the left and right front wheels 10.

[0065] The steering amount sensor 91 detects the operation position of the steering wheel 35, which is a steering device, that is, the steering amount (steering angle) of the front wheels 10. The steering amount sensor 91 is provided, for example, on a shaft connected to the pitman arm. Note that the steering amount is detected in each of the left and right directions with the value when the steering wheel 35 is in the preset straight-ahead position as the reference value. The inclination sensor 92 detects the inclination angle of the traveling vehicle body 2 in the front-rear direction.

[0066] The line drawing marker detection sensor 93 is provided for each of the left and right line drawing markers 65 to detect the positions of the line drawing markers 65. The line drawing marker detection sensor 93 detects that the line drawing marker 65 is in a non-working state when the line drawing marker 65 is in a predetermined raised position. The line drawing marker detection sensor 93 detects that the line drawing marker 65 is in contact with the ground and is in a working state when the line drawing marker 65 descends from the predetermined raised position.

[0067] In addition, signals are input to the controller 100 as operation signals from a shift operation lever 36, a sub-shift operation lever 37, a straight-ahead mode switch 46, a planting unit lift switch 47, a reference line setting switch 48, etc.

[0068] The straight-ahead mode switch 46 is a switch for switching whether to execute automatic straight-ahead. Specifically, the straight-ahead mode switch 46 is a switch for selecting whether to perform a manual operation in which the operator operates the steering wheel 35 or an automatic straight-ahead operation in which the steering motor 95 is controlled to operate the steering wheel 35. When the straight-ahead mode switch 46 is "ON", automatic straight-ahead can be executed. When the straight-ahead mode switch 46 is "OFF", automatic straight-ahead is not performed and a manual operation is performed.

[0069] The planting unit lifting switch 47 is a switch for switching whether to lift the seedling planting unit 4 or not. The planting unit lifting switch 47 is changed to the "up" and "down" positions.

[0070] When the planting unit lifting switch 47 is in the "up" position, the seedling planting unit 4 rises to a predetermined upper position (non-working position), and the seedling planting device 55 stops. When the planting unit lifting switch 47 is in the "down" position, the seedling planting unit 4 descends to a predetermined lower position (working position), and the seedling planting device 55 operates.

[0071] The reference line setting switch 48 is a switch for setting a reference line R0 that serves as a running reference for automatic straight running. When the reference line setting switch 48 is "ON", the setting of the reference line R0 becomes possible. The method for setting the reference line R0 will be described later.

[0072] Also, current position information of the machine body and the like are input from the position detection device 150 to the controller 100. The controller 100 executes an autonomous running mode in which the machine body performs work while automatically running.

[0073] Here, with reference to FIG. 5, the autonomous running of the seedling transplanter 1 in the field will be described. FIG. 5 is an explanatory diagram of the autonomous running of the seedling transplanter 1 in the field. The controller 100 (see FIG. 4) has an automatic straight running mode as the autonomous running mode, in which the steering amount of the front wheels 10 (see FIG. 1) is fed back while controlling the steering motor 95 (see FIG. 4) to operate the steering wheel 35 (see FIG. 4). Note that the seedling transplanter 1 may be capable of executing an automatic turn in which the turning run is automatically performed along the turning run path R2.

[0074] As shown in FIG. 5, in the automatic straight running mode, the seedling transplanter 1 automatically performs the work of planting seedlings while going straight along, for example, a planned running path in the field.

[0075] The seedling transplanter 1 performs seedling planting while reciprocating within a predetermined work area in the field. Regarding straight running, when the controller 100 executes the automatic straight running mode, it performs automatic running along the set straight running path R1 by executing straight assist.

[0076] The straight running path R1 is parallel to the reference line R0 that serves as the running reference. The reference line R0 is set in the field in accordance with the seedling planting direction. The controller 100 acquires the starting position of the straight running as the reference starting point (point A), which is the starting reference point. Also, the controller 100 acquires the ending position of the straight running as the final reference ending point (point B), which is the ending reference point.

[0077] The controller 100 sets the position where the reference line setting switch 48 is turned "ON", that is, the position where the reference line setting switch 48 is changed from "OFF" to "ON" as the reference starting point. Note that the method for setting the final reference ending point will be described later. The reference line setting switch 48 may include each switch for setting the reference starting point and the final reference ending point.

[0078] Then, the controller 100 stores the line segment connecting the reference starting point (point A) and the final reference ending point (point B) as the reference line R0.

[0079] The reference starting point and the reference ending point include information regarding azimuth and information regarding position. That is, the reference line R0 includes information regarding azimuth and information regarding position. Also, the straight running path R1 includes information regarding azimuth and information regarding position.

[0080] The reference line R0 is updated when the reference starting point (point A) and the final reference ending point (point B) of the straight running are updated. Also, the straight running path R1 in the next process is set parallel to the updated reference line R0.

[0081] Next, with reference to FIG. 6, the drive control of the seedling planting device 55 according to the embodiment will be described. FIG. 6 is a flowchart for explaining the drive control of the seedling planting device 55 according to the embodiment.

[0082] Note that the drive control of the seedling planting device 55 described below is executed in a state where the seedling planting unit 4 has descended to a predetermined lowering position.

[0083] The controller 100 calculates a first vehicle speed (S100). The controller 100 calculates the first vehicle speed based on information regarding the position of the traveling vehicle body 2. Specifically, the controller 100 acquires information regarding the position of the traveling vehicle body 2 detected by the position detection device 150, and calculates the first vehicle speed of the traveling vehicle body 2 based on the acquired information.

[0084] Next, the controller 100 calculates a second vehicle speed (S101). The controller 100 calculates the second vehicle speed of the traveling vehicle body 2 based on the rotational speed of the rear wheels 11 detected by the rotational speed sensor 90. For example, the controller 100 calculates the second vehicle speed from the average of the rotational speeds of the left and right rear wheels 11.

[0085] Next, the controller 100 determines whether the difference between the first vehicle speed and the second vehicle speed is equal to or greater than a predetermined value (S102). For example, the controller 100 calculates the difference between the first vehicle speed and the second vehicle speed by subtracting the smaller vehicle speed from the larger vehicle speed among the first vehicle speed and the second vehicle speed. Then, the controller 100 determines whether the difference between the first vehicle speed and the second vehicle speed is equal to or greater than a preset predetermined value. The predetermined value is a preset value and is a vehicle speed at which it can be determined that the traveling vehicle body 2 has slipped in the field. That is, the controller 100 determines whether the traveling vehicle body 2 is slipping.

[0086] When the difference between the first vehicle speed and the second vehicle speed is equal to or greater than the predetermined value, the controller 100 determines that the traveling vehicle body 2 is slipping. Also, when the difference between the first vehicle speed and the second vehicle speed is less than the predetermined value, the controller 100 determines that the traveling vehicle body 2 is not slipping.

[0087] When the controller 100 determines that the difference between the first vehicle speed and the second vehicle speed is less than a predetermined value and the traveling vehicle body 2 is not slipping (S102: No), the planting clutch 27a is engaged (S103). That is, the controller 100 sets the transmission state of the power generated by the engine 30 to the seedling planting device 55 to the engaged state, and the external extraction power taken out from the transmission case 13 is transmitted to the seedling planting device 55. As a result, the external extraction power taken out from the transmission case 13 is transmitted to the seedling planting device 55, and the planting rotary 57 rotates by the external extraction power taken out from the transmission case 13.

[0088] When the controller 100 determines that the difference between the first vehicle speed and the second vehicle speed is greater than or equal to a predetermined value and the traveling vehicle body 2 is slipping (S102: Yes), the planting clutch 27a is released (S104). That is, the controller 100 sets the transmission state of the power generated by the engine 30 to the seedling planting device 55 to the disengaged state, and the external extraction power taken out from the transmission case 13 is not transmitted to the seedling planting device 55.

[0089] Next, the controller 100 drives the planting motor 110 (S105). The controller 100 controls the planting motor 110 based on the first vehicle speed. Specifically, the controller 100 controls the rotational speed (rotation speed) of the rotating shaft of the planting motor 110 based on the first vehicle speed so that seedlings are planted in the field by the seedling planting device 55 at preset plant spacings. As a result, power is transmitted from the planting motor 110 to the seedling planting device 55, and the planting rotary 57 rotates by the power generated by the planting motor 110.

[0090] In this way, when the controller 100 detects the slip of the traveling vehicle body 2, by controlling the planting motor 110 based on the first vehicle speed, the planting by the seedling planting device 55 can be executed in accordance with the movement of the traveling vehicle body 2. Therefore, even when the traveling vehicle body 2 slips, the variation in plant spacing due to the slip is suppressed.

[0091] Next, the setting control of the reference end point according to the embodiment will be described with reference to FIG. 7. FIG. 7 is a flowchart for explaining the setting control of the reference end point according to the embodiment.

[0092] The controller 100 determines whether the setting of the reference start point (point A) has been executed (S200). Specifically, the controller 100 determines whether the reference line setting switch 48 has been changed from "OFF" to "ON". When the reference line setting switch 48 is changed from "OFF" to "ON", the controller 100 determines that the setting of the reference start point has been executed.

[0093] If the setting of the reference start point has not been executed (S200: No), that is, if the reference line setting switch 48 is maintained at "OFF", the controller 100 ends the current process.

[0094] If the setting of the reference start point has been executed (S200: Yes), the controller 100 determines whether a manual end operation has been performed by the operator for the reference end point (S201). Specifically, the controller 100 determines whether the reference line setting switch 48 has been changed from "ON" to "OFF". When the reference line setting switch 48 is changed from "ON" to "OFF", the controller 100 determines that a manual end operation has been performed.

[0095] If a manual end operation has been performed (S201: Yes), the controller 100 sets the current position of the traveling vehicle body 2 as the final reference end point (point B) (S202). Specifically, the controller 100 sets the current position of the traveling vehicle body 2 detected by the position detection device 150 as the final reference end point.

[0096] When no manual end operation is performed (S201: No), the controller 100 determines whether a turning operation has been started (S203). For example, when the planting unit lifting switch 47 is changed to the "raise" position, the controller 100 determines that the turning operation has been started. Also, the controller 100 may determine that the turning operation has been started when the steering amount of the front wheels 10 becomes equal to or greater than a predetermined steering amount. The predetermined steering amount is a value set in advance and is a value that can determine that the traveling vehicle body 2 has started to turn.

[0097] When the turning operation has not been started (S203: No), the controller 100 measures the moving distance of the traveling vehicle body 2 (S204). Specifically, the controller 100 measures the moving distance of the traveling vehicle body 2 based on the position information of the traveling vehicle body 2 detected by the position detection device 150. If the controller 100 has not started measuring the moving distance of the traveling vehicle body 2, it starts measuring the moving distance. For example, the controller 100 starts measuring the moving distance immediately after the reference starting point is set.

[0098] Next, the controller 100 determines whether the measured moving distance of the traveling vehicle body 2 is equal to or greater than a predetermined distance (S205). The predetermined distance is a distance set in advance, for example, 5 m.

[0099] If the moving distance of the traveling vehicle body 2 is less than the predetermined distance (S205: No), the controller 100 returns to step S201 and repeats the above process.

[0100] If the moving distance of the traveling vehicle body 2 is equal to or greater than the predetermined distance (S205: Yes), the controller 100 sets a reference end point (point B) (S206). The controller 100 sets the current position of the traveling vehicle body 2 detected by the position detection device 150 as the reference end point (point B). The controller 100 sets the reference end point every time the traveling vehicle body 2 advances a predetermined distance. That is, the controller 100 updates the reference end point every time the traveling vehicle body 2 advances a predetermined distance. In this way, the controller 100 automatically sets the reference end point.

[0101] Next, the controller 100 resets the measured moving distance (S207). After the controller 100 resets the moving distance, it returns to step S201 and repeats the above process. Note that when the process proceeds to step S204 after the moving distance is reset, the measurement of the moving distance starts again.

[0102] When the turning operation is started (S203: Yes), the controller 100 sets the current reference end point to the final reference end point (point B) (S206). Thereby, even when the operator forgets to turn off the reference line setting switch 48, the final reference end point is automatically set when the turning operation is started.

[0103] Note that when a manual end operation is performed in a state where the reference end point is automatically set, the automatically set reference end point is reset (deleted), and the position of the traveling vehicle body 2 when the manual end operation is performed is set as the final reference end point. Also, when a manual end operation is performed while the moving distance is being measured, or when a turning operation is started while the moving distance is being measured, the moving distance is reset.

[0104] Also, the above-mentioned predetermined distance may be settable. For example, the predetermined distance may be settable by the operator. The operator can set, for example, a predetermined distance according to the field.

[0105] The seedling transplanter 1 includes a traveling vehicle body 2, a seedling planting device 55, an engine 30, a planting clutch 27a, a planting motor 110, and a controller 100. The traveling vehicle body 2 has front wheels 10 and rear wheels 11. The seedling planting device 55 is attached to the traveling vehicle body 2. The engine 30 generates power for rotating the front wheels 10 and the rear wheels 11. The planting clutch 27a switches the transmission state of the power generated by the engine 30 to the seedling planting device 55. The planting motor 110 can drive the seedling planting device 55. The controller 100 controls the planting clutch 27a and the planting motor 110. When no slip of the traveling vehicle body 2 is detected, the controller 100 sets the transmission state to the engaged state and drives the seedling planting device 55 with the power generated by the engine 30. When a slip of the traveling vehicle body 2 is detected, the controller 100 sets the transmission state to the disengaged state and drives the seedling planting device 55 with the power generated by the planting motor 110.

[0106] Thereby, even when the traveling vehicle body 2 slips, the seedling transplanter 1 can drive the seedling planting device 55 with the planting motor 110 to plant seedlings in the field, and can suppress a decrease in working accuracy.

[0107] The seedling transplanter 1 includes a first planting transmission shaft 67 and a second planting transmission shaft 111. The first planting transmission shaft 67 transmits the power generated by the engine 30 to the seedling planting device 55. The second planting transmission shaft 111 transmits the power generated by the planting motor 110 to the seedling planting device 55.

[0108] Thereby, the seedling transplanter 1 can transmit power to the seedling planting device 55 from the engine 30 and the planting motor 110 through different paths. Therefore, the seedling transplanter 1 can suppress the complication of the power transmission path from the engine 30 and the planting motor 110 to the seedling planting device 55, and can suppress an increase in cost.

[0109] The seedling transplanter 1 includes a position detection device 150 and a rotation speed sensor 90. The position detection device 150 detects information regarding the position of the traveling vehicle body 2. The rotation speed sensor 90 detects the rotation speed of the rear wheels 11. When the difference between a first vehicle speed calculated based on information regarding the position of the traveling vehicle body 2 and a second vehicle speed calculated based on the rotation speed is equal to or greater than a predetermined value, the controller 100 detects slip of the traveling vehicle body 2. When the controller 100 does not detect slip of the traveling vehicle body 2, the controller 100 does not drive the planting motor 110.

[0110] Thereby, when slip is not detected, the seedling transplanter 1 can suppress the power consumed by the planting motor 110.

[0111] When the controller 100 detects slip of the traveling vehicle body 2, the controller 100 controls the planting motor 110 based on the first vehicle speed to cause the seedling planting device 55 to perform planting.

[0112] Thereby, even when the traveling vehicle body 2 slips, the seedling transplanter 1 can plant seedlings in the field according to the actual movement of the traveling vehicle body 2 and can align the plant intervals. Therefore, even when the traveling vehicle body 2 slips, the seedling transplanter 1 can use the seedling mat in the field as planned. In addition, the seedling transplanter 1 can suppress the plant intervals from being narrow, that is, the seedlings from being densely planted, and can improve the growth of the seedlings.

[0113] When the seedling planting device 55 is driven by the power generated by the engine 30, the planting motor 110 functions as a generator. The power generated by the planting motor 110 is stored in the storage battery 112.

[0114] Thereby, the seedling transplanter 1 can charge the storage battery 112 while driving the seedling planting device 55 by the power generated by the engine 30.

[0115] The seedling transplanter 1 is equipped with a fertilizer application device 5. The fertilizer application device 5 is provided on the traveling vehicle body 2 and supplies fertilizer to the field. The fertilizer application device 5 includes a feeding motor 71a that drives a feeding unit for feeding fertilizer from a fertilizer hopper 70. The feeding motor 71a is supplied with power from a storage battery 112.

[0116] Thereby, the seedling transplanter 1 can efficiently use the electric power generated by the planting motor 110.

[0117] The seedling transplanter 1 includes a handle 35 and a steering motor 95. The handle 35 is provided on the traveling vehicle body 2. The steering motor 95 drives the handle 35 when the traveling vehicle body 2 executes automatic straight running. The controller 100 updates the reference end point (point B) every time the traveling vehicle body 2 advances a predetermined distance.

[0118] Thereby, when setting the reference line R0 that serves as the traveling reference for automatic straight running, the seedling transplanter 1 can automatically set the reference end point in accordance with the straight running of the traveling vehicle body 2. Also, by updating the reference end point, when the straight running for setting the reference line R0 becomes longer, the seedling transplanter 1 can set the reference line R0 longer in accordance with the running of the traveling vehicle body 2. Therefore, the seedling transplanter 1 can improve the accuracy of the reference line R0.

[0119] When a manual end operation is performed, the controller 100 sets the position where the manual end operation was performed as the final reference end point.

[0120] Thereby, the seedling transplanter 1 can set the final reference end point according to the operation of the operator. For example, even when the seedling transplanter 1 is automatically setting the reference end point, it can prioritize the operation of the operator and set the position where the manual end operation was performed as the final reference end point.

[0121] When the turning operation of the traveling vehicle body 2 is started without a manual end operation being performed, the controller 100 sets the current final end point as the final reference end point.

[0122] Accordingly, even if an operator forgets to turn off the reference line setting switch 48, for example, the seedling transplanter 1 can set the final reference end point.

[0123] The seedling transplanter 1 according to the modification may have the following configuration or the like.

[0124] The seedling transplanter 1 may be provided with a clutch on the second planting transmission shaft 111. The clutch is released when the planting motor 110 does not drive the seedling planting device 55. That is, when the traveling vehicle body 2 is not slipping, the clutch is released. Further, the clutch is engaged when the planting motor 110 drives the seedling planting device 55. That is, when the traveling vehicle body 2 is slipping, the clutch is engaged. The clutch is released and engaged by a solenoid or the like.

[0125] In this way, when the traveling vehicle body 2 of the seedling transplanter 1 is slipping, the clutch is engaged to drive the seedling planting device 55 by the planting motor 110. When the traveling vehicle body 2 of the seedling transplanter 1 is not slipping, the load on the engine 30 can be reduced by releasing the clutch.

[0126] When the seedling transplanter 1 sets the reference start point (point A), it displays on the monitor 86 that the reference end point (point B) is being acquired. Thereby, the seedling transplanter 1 can notify the operator that the reference end point is being acquired.

[0127] After the seedling transplanter 1 sets the reference start point and then sets the reference end point (point B), that is, when the traveling vehicle body 2 advances a predetermined distance and automatically sets the reference end point, the monitor 86 displays that the reference end point has been set. Thereby, the seedling transplanter 1 can notify the operator that the reference end point has been set.

[0128] When a manual end operation is performed on the seedling transplanter 1 to set the final reference end point (point B), the display on the monitor 86 that was being shown is stopped. That is, the seedling transplanter 1 ends the display on the monitor 86 indicating that it is acquiring the reference end point (point B), or the display indicating that the reference end point has been set.

[0129] After the seedling transplanter 1 sets the reference line R0, that is, after setting the reference start point (point A) and the final reference end point (point B), the reference start point and the final reference end point may be changeable. For example, a reference line R0 including the reference start point and the final reference end point is displayed on the monitor 86. The operator can change the reference start point and the final reference end point by operating them on the monitor 86. For example, the operator can extend the reference line R0 by changing the final reference end point.

[0130] Thereby, the operator can set the reference line R0 according to the actual field. For example, when the length of the path traveled to set the reference line R0 is shorter than the length of another path corresponding to the straight-ahead travel path R1, the operator can change the reference start point or the final reference end point to set a reference line R0 that matches the length of the other path.

[0131] After the seedling transplanter 1 sets the reference line R0, information regarding the shape of the field can be added. For example, as shown in FIG. 8, when a part of the field is recessed in plan view, the position information of the recessed shape can be set. FIG. 8 is a diagram showing the path along which the seedling transplanter 1 automatically travels in a field with a recessed shape.

[0132] Further, after setting the reference line R0, the seedling transplanter 1 may be able to change the distance of the straight travel path R1 with respect to the reference line R0. Also, the seedling transplanter 1 may be able to set an area for changing the straight travel path R1 with respect to the field. In other words, the seedling transplanter 1 may be able to set a distance (width) for changing the length of the straight travel path R1 in a direction (left - right direction) orthogonal to the straight travel path R1. For example, by inputting the position information of the area for changing the straight travel path R1, the area for changing the straight travel path R1 is set.

[0133] For example, the operator can set a straight travel path R1 - 1 that is shorter in distance than the straight travel path R1 set according to the reference line R0 according to the shape of the field. For example, on the monitor 86 and the terminal device, the shape of the field, the reference line R0, the straight travel path R1, etc. are displayed, and the operator can set the straight travel path R1 - 1 while checking the display screen. Therefore, the operator can easily set the straight travel paths R1 and R1 - 1 according to the shape of the field.

[0134] Also, as shown in FIG. 9, the seedling transplanter 1 may be able to automatically travel straight across a recessed - shaped area A (for example, a ridge). FIG. 9 is a diagram showing the path along which the seedling transplanter 1 automatically travels straight in a recessed - shaped field. Note that the area A can be set after setting the reference line R0. For example, by inputting the position information of the area A, the area A is set. The area A may be set by a distance. For example, the area A may be set by a distance along the straight travel path R1 and a distance in a direction (left - right direction) orthogonal to the straight travel path R.

[0135] When the seedling transplanter 1 travels in area A, the seedling planting unit 4 is raised to a predetermined raised position. Thereby, when the seedling transplanter 1 travels in area A, it is possible to prevent the seedling planting unit 4 from contacting a ridge or the like. Further, when the seedling transplanter 1 travels in area A, it may be possible to set the vehicle speed in area A. Further, when the seedling transplanter 1 travels in area A, it may be possible to set a determination value for suppressing the overturning of the traveling vehicle body 2. For example, when the inclination angle of the traveling vehicle body 2 becomes equal to or greater than the determination value, the seedling transplanter 1 executes safety control such as stopping the traveling vehicle body 2.

[0136] Further, when the seedling transplanter 1 travels in area A, it may cancel the automatic straight travel and change to manual operation. Further, when the seedling transplanter 1 enters area A, the operator may be asked whether to change from automatic straight travel to manual operation, and the operator may be allowed to select whether to travel in area A by automatic straight travel or to travel in area A by manual operation.

[0137] The seedling transplanter 1 determines whether it is possible to travel in area A based on the position information of the traveling vehicle body 2 detected by the position detection device 150, the second vehicle speed detected by the rotation speed sensor 90, the inclination angle of the traveling vehicle body 2 detected by the inclination sensor 92, and the like.

[0138] When the seedling transplanter 1 cannot travel through area A by automatic straight travel, it changes to manual operation. When the seedling transplanter 1 cannot travel through area A by automatic straight travel, it may detour around area A, set a route that can be traveled by automatic travel, and perform automatic travel along the set route. When the seedling transplanter 1 cannot travel through area A by automatic straight travel, it may stop the traveling vehicle body 2. The seedling transplanter 1 may be configured such that the operator can select whether to perform automatic travel along the set route or stop the traveling vehicle body 2. Further, it may be possible to select whether to perform automatic travel along the set route or stop the traveling vehicle body 2 by a remote controller capable of remotely operating the seedling transplanter 1. Further, it may be possible to display on a user's terminal device or the like whether to perform automatic travel along the set route or stop the traveling vehicle body 2. In this case, for example, various types of information are transmitted to the terminal device via a communication line circuit such as 5G.

[0139] Further effects and modifications can be easily derived by those skilled in the art. For this reason, the broader aspects of the present invention are not limited to the specific details and representative embodiments represented and described as above. Therefore, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Reference Numerals

[0140] 1 Seedling transplanter (working vehicle) 2 Traveling vehicle body 4 Seedling planting unit 5 Fertilizer applicator 10 Front wheels (drive wheels) 11 Rear wheels (drive wheels) 27a Planting clutch (clutch) 30 Engine (drive source) 35 Steering wheel 55 Seedling planting device (planting device) 67 First planting transmission shaft (first drive shaft) 70 Fertilizer hopper (fertilizer tank) 71a Pay-out motor 90 Rotation speed sensor 95 Steering motor 100 Controller 110 Planting motor 111 Second planting transmission shaft 112 Storage battery 150 Position detection device

Claims

1. A traveling vehicle body having drive wheels, A planting device attached to the traveling vehicle body, A drive source that generates power to rotate the drive wheels, A clutch that switches the transmission state of the power generated by the drive source to the planting device, A motor capable of driving the planting device, A control device that controls the clutch and the motor Comprising, The control device, When slip of the traveling vehicle body is not detected, the transmission state is set to the engaged state and the planting device is driven by the power generated by the drive source, When slip of the traveling vehicle body is detected, the transmission state is set to the disengaged state and the planting device is driven by the power generated by the motor, a work vehicle.

2. A first drive shaft that transmits the power generated by the drive source to the planting device, A second drive shaft that transmits the power generated by the motor to the planting device Comprising, the work vehicle according to claim 1.

3. A position detection device that detects information regarding the position of the traveling vehicle body, A rotation speed sensor that detects the rotation speed of the drive wheels Comprising, The control device, When the difference between a first vehicle speed calculated based on information regarding the position of the traveling vehicle body and a second vehicle speed calculated based on the rotation speed is equal to or greater than a predetermined value, the slip is detected, When the slip is not detected, the motor is not driven, the work vehicle according to claim 1.

4. The control device controls the motor based on the first vehicle speed and executes planting by the planting device when the slip is detected, the work vehicle according to claim 3.

5. The motor functions as a generator when the planting device is driven by the power generated by the drive source, The electric power generated by the motor is stored in a storage battery, the work vehicle according to claim 1.

6. A fertilizer application device provided on the traveling vehicle body for supplying fertilizer to a field Comprising, The fertilizer application device, A feeding motor that drives a feeding unit that feeds fertilizer from a fertilizer tank Comprising, The feeding motor is supplied with electric power from the storage battery, the work vehicle according to claim 5.

7. A steering wheel provided on the traveling vehicle body, A steering motor that drives the steering wheel when the traveling vehicle body executes automatic straight running Comprising, The control device, The control device updates a reference end point of a reference line serving as a traveling reference for the automatic straight running every time the traveling vehicle body advances a predetermined distance, the work vehicle according to claim 1. Claim 8 The work vehicle according to claim 7, wherein the predetermined distance is changeable. Claim 9 The work vehicle according to claim 7, wherein when a reference end point setting operation is performed by an operator, the control device sets the position where the setting operation is performed as the final reference end point. Claim 10 The work vehicle according to claim 7, wherein when the turning operation of the traveling vehicle body is started in a state where a reference end point setting operation is not performed by an operator, the control device sets the current reference end point as the final end point. Claim 11 The work vehicle according to claim 9 or 10, wherein the reference start point of the reference line and the final reference end point are changeable after the final reference end point is set.

Images