JP7768209B2 - Work vehicles - Google Patents

Description

The present invention relates to a work vehicle.

Conventionally, there are known work vehicles that output power generated by an engine via a transmission case to a traveling device and a planting device, which is a working unit (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.

JP 2014-70653 A

However, if the vehicle body of a conventional work vehicle slips in a field where it is working, there is a risk that the spacing between seedlings transplanted into the field by a planting device may deviate from the spacing that would be present if the vehicle body were not slipping. In other words, if the vehicle body of a conventional work vehicle slips, there is a risk that the work accuracy will decrease.

The present invention was made in consideration of the above, and aims to provide a work vehicle that prevents a decrease in work accuracy even when the traveling vehicle body slips.

To solve the above-mentioned problems and achieve the objectives, a work vehicle (1) according to one embodiment includes a traveling body (2) having drive wheels (10, 11), a planting device (55) attached to the traveling body (2), a drive source (30) that generates power to rotate 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 slippage of the traveling body (2) is not detected, the control device (100) switches the transmission state to an on state to drive the planting device (55) with power generated by the drive source (30), and when slippage of the traveling body (2) is detected, switches the transmission state to a off state to drive the planting device (55) with power generated by the motor (110).

According to one aspect of the embodiment, a work vehicle can prevent a decrease in work accuracy when the traveling vehicle body slips.

FIG. 1 is a side view showing a work vehicle. FIG. 2 is a plan view showing the work vehicle. FIG. 3 is a schematic diagram showing a part of the seedling planting device. FIG. 4 is a block diagram showing a control system centered on the control device of the seedling transplanter. FIG. 5 is an explanatory diagram of autonomous travel of the seedling transplanter in a farm field. FIG. 6 is a flowchart illustrating the drive control of the seedling planting device according to the embodiment. FIG. 7 is a flowchart illustrating the setting control of the reference end point according to the embodiment. FIG. 8 is a diagram showing a path along which the seedling transplanter automatically moves straight in a field having a concave shape. FIG. 9 is a diagram showing a path along which the seedling transplanter automatically moves straight in a field having a concave shape.

First, an overview of the work vehicle 1 according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a side view showing the work vehicle 1. Figure 2 is a plan view showing the work vehicle 1.

In the following description, the fore-and-aft direction refers to the direction of travel of the work vehicle 1 when traveling straight, with the forward side of the traveling direction being defined as "front" and the rear side being defined as "rear." The traveling direction of the work vehicle 1 is the direction from the driver's seat 41 toward the handlebars 35 (steering device) when traveling straight (see Figures 1 and 2).

The left-right direction is the direction that is horizontally perpendicular to the front-to-rear direction, and defines left and right facing the "front." In other words, when the operator (also called the worker) is seated in the operator's seat 41 and facing forward, the left-hand side is the "left" and the right-hand side is the "right."

The up-down direction refers to the vertical direction. The front-to-back, left-to-right, and up-down directions are perpendicular to each other. Each direction is defined for the convenience of explanation, and the present invention is not limited to these directions.

In this embodiment, the work vehicle 1 is described as a riding seedling transplanter 1 equipped with a seedling planting unit 4 as a work machine and adapted to receive seedlings in a field. As shown in Figures 1 and 2, the seedling transplanter 1 is equipped with a seedling planting unit 4 that can be raised and lowered via a lifting link mechanism 3 on the rear side of the traveling vehicle body 2 to plant seedlings in the field.

The main body of the fertilizer applicator 5 is located on the upper rear of the traveling vehicle body 2. Note that if the work vehicle 1 is not a seedling transplanter 1, it may be equipped with a seed sowing device or other work equipment that supplies seeds.

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

The engine 30 generates power to rotate the front wheels 10 and rear wheels 11. The power generated by the engine 30 is transmitted to the seedling planting unit 4 via the planting clutch 27a (described below), driving the seedling planting unit 4.

The continuously variable transmission 14 is a hydrostatic continuously variable transmission known as an HST (Hydro Static Transmission). The following describes the case where the continuously variable transmission is an HST 14.

The transmission case 13 contains an auxiliary transmission mechanism 16 that switches the driving mode of the vehicle body 2 between high-speed mode for road driving and low-speed mode for planting seedlings. Front wheel final cases 10a are provided on the left and right sides of the transmission case 13, and front wheels 10 are attached to left and right front axles 10b that protrude outward from front wheel support sections that can change the steering direction of the left and right front wheel final cases 10a.

Furthermore, rear wheel gear cases 11a are attached to the left and right sides of the rear frame 22 (see Figure 2) that is arranged laterally at the rear side of the main frame 15, and rear wheels 11 are attached to left and right rear axles 11b that protrude outward from the rear wheel gear cases 11a.

In addition, left and right link support frames 23 that support the lifting link mechanism 3 protrude upward from the upper part of the rear frame 22. A pair of left and right lower link arms 24 are provided below and between the left and right link support frames 23. A hydraulically operated lifting cylinder 25 is provided between the left and right lower link arms 24.

An upper link arm 26 is provided above the lifting cylinder 25, forming the lifting link mechanism 3, which is a parallel link mechanism. The left and right lower link arms 24, the lifting cylinder 25, and the other end of the upper link arm 26, each of which has one end connected to the traveling vehicle body 2, are attached to the front of the seedling planting section 4.

An engine 30 is also mounted on the main frame 15. The rotational power of the engine 30 is transmitted to the transmission case 13 via the belt transmission 21 and the HST 14. The rotational power transmitted to the transmission case 13 is changed in speed by the sub-transmission mechanism 16 inside the transmission case 13, and then separated into driving power and externally extracted power. In other words, the driving power output from the transmission case 13 is transmitted to the front wheels 10 and rear wheels 11.

In addition, the externally extracted power extracted from the rotational power transmitted to the transmission case 13 is transmitted to the planting clutch case 27 located at the rear of the traveling body 2. The externally extracted power is then transmitted from the planting clutch case 27 to the seedling planting section 4 via the first planting transmission shaft 67 and the planting clutch 27a (see Figure 4).

The rotational power of the engine 30 is also transmitted to a hydraulic pump (not shown). The hydraulic pressure generated by the hydraulic pump is supplied to the HST 14, the power steering mechanism 88 of the handle 35 (see Figure 4), the lift cylinder 25, etc.

Left and right drive shafts 42 are provided at the rear of the transmission case 13. 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.

In addition, a side clutch 44 (see Figure 4) that switches power transmission to the left and right drive shafts 42 is located upstream of the left and right drive shafts 42 in the transmission direction. As shown in Figure 1, a side clutch pedal 43a that switches the left and right side clutches 44 on and off is provided at the lower front of the cockpit 41, on either the left or right side.

By depressing the inside side clutch pedal 43a of the left and right side clutch pedals 43a to disengage the side clutch 44 and then operating the steering wheel 35 to make a turn, the drive rotation of the rear wheel 11 on the inside of the turn can be completely interrupted.

A hood 39 is provided at the upper front of the vehicle body 2, and has a control panel 38 on top for operating each section. The control panel 38 is equipped with a monitor 86 (see Figure 4) and other devices.

The hood 39 also includes a handlebar 35 for steering the traveling vehicle body 2, a speed change control lever 36 for operating the HST 14 and the seedling planting unit 4, and an auxiliary speed change control lever 37 for operating the auxiliary speed change mechanism 16.

In addition, an openable front cover 40 is provided in front of the hood 39. Inside the front cover 40, a fuel tank, a battery, and an interlocking mechanism that rotates the left and right front wheels 10 and the lower sides of the left and right front wheel final cases 10a in response to steering of the handlebars 35 are provided. The front wheels 10 are, for example, steerable wheels that turn in response to steering of the handlebars 35.

An engine cover 30a that covers the top and sides of the engine 30 is provided behind the hood 39 and above the engine 30, and a pilot's seat 41 where the pilot sits is provided above the engine cover 30a.

The fertilizer applicator 5 is mounted behind the driver's seat 41, at the rear end of the main frame 15. Power for the fertilizer applicator 5 is transmitted by a fertilizer transmission mechanism mounted on one side of the left or right rear wheel gear case 11a, facing the fertilizer applicator 5.

Approximately horizontal floor steps 33 are formed on both the left and right sides of the lower part of the engine cover 30a and hood 39. As shown in Figure 2, the floor steps 33 are partially lattice-shaped, so that even if mud gets on the shoes of an operator walking on the floor steps 33, it will fall into the field.

Furthermore, as shown in Figure 2, a rear step 330 is connected to the rear of the floor step 33. The surface of the rear step 330 is preferably treated with an anti-slip finish, for example, with a pattern of multiple protrusions, to prevent feet from slipping during work.

In addition, spare seedling frames 50 are provided on both the left and right sides of the front of the traveling vehicle body 2, with multiple spare seedling loading platforms 52 arranged at intervals in the vertical direction on seedling frame supports 51, allowing work materials such as seedlings and fertilizer bags to be placed on them to be replenished in the seedling planting section 4.

A seedling tank 53 for carrying seedlings to be planted in the field is attached to the rear end of the lifting link mechanism 3, along with a sliding mechanism for sliding it left and right. Seedling partition fences 54, which are long in the vertical direction, are placed on the seedling tank 53 at predetermined intervals left and right. A seedling planting device 55 (planting device) is placed below the seedling tank 53 to pick up the loaded seedlings and plant them in the field.

The seedling planting device 55 simultaneously plants eight rows, the same number as the number of rows separated by the seedling partition fence 54. The seedling planting device 55 has four planting transmission cases 56 arranged at intervals below the seedling tank 53. Each planting transmission case 56 is fitted with a planting rotary 57 that rotates on both the left and right sides of the planting transmission case 56 to pick up seedlings using a planting rod 58 and plant them in the field.

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

Specifically, when the planting clutch 27a is engaged, the externally extracted power taken 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 Figure 3. In other words, the first planting transmission shaft 67 transmits the power generated by the engine 30 to the seedling planting device 55. Figure 3 is a schematic diagram showing a portion of the seedling planting device 55.

The first planting transmission shaft 67 is connected to the power transmission mechanism 68 of the seedling planting device 55 so as to transmit power. The power transmission mechanism 68 is configured to transmit power to the planting rotary 57. The power transmission mechanism 68 includes gears, a rotating shaft, a belt mechanism, and the like.

The seedling planting device 55 can be driven by a planting motor 110 (motor). Specifically, 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 that power can be transmitted. In other words, 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.

Returning to Figures 1 and 2, the fertilizer applicator 5 has a fertilizer hopper 70 (fertilizer tank) that stores fertilizer, which is divided into the same number of sections as the number of working rows in the seedling planting section 4 (eight rows in the example shown in Figure 2). Since an eight-row fertilizer hopper 70 is long in the left-right direction, making it less convenient to add fertilizer and to attach and detach it, it may instead have a so-called side fertilizer structure, with four-row sections lined up on each side.

A dispensing device 71 is provided for each row below the fertilizer hopper 70. The dispensing unit has a dispensing section that supplies a set amount of fertilizer. The dispensing section is driven by a dispensing motor 71a. For example, the dispensing section is rotated by the dispensing motor 71a. The dispensing section has a recess that can hold fertilizer. When the recess faces upward, fertilizer enters from the fertilizer hopper 70, and when the recess faces downward, fertilizer is discharged downward. Fertilizer is discharged from the fertilizer hopper 70 when the dispensing section is rotated by the dispensing motor 71a.

A ventilation duct 72 is provided below the dispensing device 71, extending laterally, through which the air carrying the fertilizer passes. A fertilizer application hose 73 is provided below the dispensing device 71 to guide the fertilizer near the seedling planting position in the seedling planting section 4. A blower 74 is provided at one end of the ventilation duct 72, and is operated by an electric blower motor 76 to generate the air carrying the fertilizer.

As shown in Figures 1 and 2, below the seedling planting section 4, a center float 62C that slides on the field surface and two side floats 62L and 62R are provided that can rotate freely around their axes. Note that the center float 62C and the left and right side floats 62L and 62R are sometimes collectively referred to as floats 62.

Furthermore, below the seedling planting section 4, and forward of the float 62, a ground leveling rotor 63 is provided to level any unevenness in the field. Power is transmitted to the ground leveling rotor 63 from the rear wheel gear case 11a on the other left or right side via a rotor transmission shaft 63a.

As shown in Figure 1, line-drawing markers 65 are provided on both the left and right sides of the seedling planting unit 4; one side touches the ground on the field surface to form a groove that serves as a guide for traveling in the next work row (next process). When one side of the line-drawing markers 65 touches the ground, the other side moves upward; when the seedling planting unit 4 is raised during rotation, both sides move upward; and when the seedling planting unit 4 descends after rotation, one side moves upward and the other side touches the ground.

As shown in Figures 1 and 2, a vertically long center mascot 66 is provided in the left-right center of the traveling vehicle body 2, in front of the hood 39. By aligning the center mascot 66 with the grooves formed in the field by the left and right line markers 65, traveling can be aligned with the work position of the previous work row, improving work accuracy and preventing non-working situations.

Depending on the soil quality of the field, the guide lines formed by the left and right line-drawing markers 65 may quickly become buried, causing the guide for going straight to disappear. In such cases, it is a good idea to use the left and right side markers 19, which are located forward of the left and right line-drawing markers 65. In other words, by moving the left and right side markers 19 outward and positioning them above the planted seedlings, planting work can be coordinated with the planting of seedlings in the previous work row.

As shown in FIG. 1, the seedling transplanter 1 is also equipped 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 related to the position of the traveling vehicle body 2 and the orientation of the traveling vehicle body 2. The position detection device 150 includes, for example, a direction sensor and positioning means such as a GPS (Global Positioning System) or a GNSS (Global Navigation Satellite System). The position detection device 150 may be composed of multiple devices. The position detection device 150 may include a camera or an ultrasonic sensor, and may acquire a turning position in the field and detect the distance to the turning position.

For example, the position detection device 150 receives positioning information from the positioning means, creates current position information and direction information for the traveling vehicle body 2 based on the received positioning information, and detects the current position and direction. The position detection device 150 is attached to the mounting stay 59, for example, and positioned above the traveling vehicle body 2.

The straight-line control program and the turning control program, which are created based on position information from the position detection device 150, are stored in separate locations. The straight-line control program is stored, for example, in a straight-line control ECU (Electronic Control Unit) 100a in the position detection device 150, and the turning control program is stored, for example, in a turning control ECU 100b housed in the hood 39. The straight-line control ECU 100a and the turning control ECU 100b are included in the control device 100 (see Figure 4), which will be described later. The straight-line control ECU 100a and the turning control ECU 100b may also be stored in the same ECU.

Next, the control system of the seedling transplanter 1 will be described with reference to Figure 4. Figure 4 is a block diagram showing the control system, centered around the control device 100 of the seedling transplanter 1. The seedling transplanter 1 is capable of controlling each part electronically, and is equipped with a control device (hereinafter referred to as a controller) 100 that controls each part.

The controller 100 is equipped with a processing unit including a CPU (Central Processing Unit), a memory unit including ROM (Read Only Memory) and RAM (Random Access Memory), and an input/output unit, all of which are interconnected to allow signals to be exchanged between them. The memory unit stores computer programs that control the seedling transplanter 1. The controller 100 performs each function by reading out the computer programs stored in the memory unit.

The controller 100 is connected to actuators such as a throttle motor 80, hydraulic control valves 81 and 82, a planting clutch actuation solenoid 83, and a side clutch actuation solenoid 84. The controller 100 is also connected to an HST motor 85, a line-drawing marker lifting motor 87, a steering motor 95, a differential lock switching motor 96, a planting motor 110, and a payout motor 71a.

The throttle motor 80 increases or decreases the rotation speed of the output shaft of the engine 30 by operating a throttle that adjusts the amount of air intake into the engine 30. The hydraulic control valve 81 controls the extension and retraction of the lift 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 actuation solenoid 83 actuates the planting clutch 27a. In other words, the controller 100 controls the planting clutch 27a by controlling the planting clutch actuation solenoid 83.

The side clutch actuation solenoid 84 actuates the side clutch 44, which switches the state of power transmission to the rear wheels 11 (see Figure 1). A side clutch 44 is provided on each of the left and right rear wheels 11, and two side clutch actuation solenoids 84 are provided, one for each side clutch 44.

The HST motor 85 changes the rotation angle of the trunnion of the HST 14, thereby changing the inclination angle of the swash plate of the HST 14. The line drawing marker lift motor 87 raises and lowers the line drawing marker 65.

The steering motor 95 rotates the steering wheel 35. The steering motor 95 is a motor that drives the steering wheel 35, which adjusts the steering amount (steering angle) of the front wheels 10 (see Figure 1) when the traveling vehicle body 2 performs automatic straight-ahead driving.

The differential lock switching motor 96 is a motor that switches between operating and deactivating a differential lock mechanism 97 (hereinafter referred to as the differential lock mechanism), which rotates the left and right running wheels, specifically the left and right front wheels 10, at the same rotational speed. When the differential lock mechanism 97 is engaged, the left and right running wheels rotate at the same rotational speed.

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 rotary 57. When the power generated by the engine 30 is transmitted in the engaged state, i.e., when the planting clutch 27a is engaged, the planting motor 110 functions as a generator. Specifically, the planting motor 110 generates electricity by transmitting external power extracted from the transmission case 13 via the power transmission mechanism 68 and the second planting transmission shaft 111.

The planting motor 110 is supplied with power from a storage battery 112 (see Figure 3). Furthermore, the power generated by the planting motor 110 is supplied to the storage battery 112. In other words, the storage battery 112 is charged by the power generated by the planting motor 110. The storage battery 112 is, for example, a lithium-ion battery or a nickel-metal hydride battery.

The dispensing motor 71a drives the dispensing unit, which discharges a set amount of fertilizer from the fertilizer hopper 70 below the dispensing device 71. The dispensing motor 71a is supplied with power, for example, from the storage battery 112.

Detection devices such as a rotation speed sensor 90, a steering amount sensor 91, and an inclination sensor 92 are connected to the controller 100. Two rotation speed sensors 90 are provided, one for each of the left and right rear wheels 11, and 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.

The steering amount sensor 91 detects the operating position of the steering wheel 35, which is the steering device, i.e., the steering amount (steering angle) of the front wheels 10. The steering amount sensor 91 is mounted, for example, on a shaft connected to a pitman arm. The steering amount is detected in both the left and right directions, with the value when the steering wheel 35 is in a preset straight-ahead position used as a reference value. The tilt sensor 92 detects the tilt angle of the vehicle body 2 in the fore-and-aft direction.

A line drawing marker detection sensor 93 is provided for each of the left and right line drawing markers 65 and detects the position of the line drawing marker 65. 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 a non-working state. When the line drawing marker 65 descends from the 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.

In addition, signals are input to the controller 100 as operation signals from the speed change operation lever 36, the auxiliary speed change operation lever 37, the straight-line mode switch 46, the planting section lift switch 47, the reference line setting switch 48, etc.

The straight-ahead mode switch 46 is a switch that switches whether or not automatic straight-ahead driving is performed. Specifically, the straight-ahead mode switch 46 is a switch that selects whether to perform manual operation in which the operator operates the steering wheel 35, or automatic straight-ahead driving 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 driving can be performed. When the straight-ahead mode switch 46 is "OFF," automatic straight-ahead driving is not performed and manual operation is performed.

The planting section lift switch 47 is a switch that switches whether or not the seedling planting section 4 is raised or lowered. The planting section lift switch 47 can be changed to the "raise" or "lower" position.

When the planting unit lift switch 47 is in the "up" position, the seedling planting unit 4 rises to a predetermined raised position (non-working position) and the seedling planting device 55 stops. When the planting unit lift switch 47 is in the "down" position, the seedling planting unit 4 descends to a predetermined lowered position (working position) and the seedling planting device 55 operates.

The reference line setting switch 48 is a switch for setting the reference line R0, which serves as the driving reference for automatic straight-ahead driving. When the reference line setting switch 48 is "ON," it becomes possible to set the reference line R0. The method for setting the reference line R0 will be described later.

In addition, the controller 100 receives input of the current location information of the vehicle from the position detection device 150. The controller 100 executes an autonomous driving mode in which the vehicle performs work while driving automatically.

Now, referring to Figure 5, we will explain autonomous driving in a field by the seedling transplanter 1. Figure 5 is an explanatory diagram of the autonomous driving of the seedling transplanter 1 in a field. The controller 100 (see Figure 4) has an automatic straight-line mode as an autonomous driving mode in which the steering motor 95 (see Figure 4) is controlled to operate the handlebars 35 (see Figure 4) while feeding back the steering amount of the front wheels 10 (see Figure 1). Note that the seedling transplanter 1 may also be capable of automatic turning, in which turning driving is performed automatically along the turning driving path R2.

As shown in Figure 5, in the automatic straight-line mode, the seedling transplanter 1 automatically performs seedling planting work in a field while moving straight along a planned travel route, for example.

The seedling transplanter 1 plants seedlings while traveling back and forth within a specified work area in the field. When the controller 100 is in automatic straight-line mode, it automatically travels along the set straight-line travel route R1 by performing straight-line assistance.

The straight-line travel path R1 is parallel to a reference line R0, which serves as the travel reference. The reference line R0 is set in the field to match the planting direction of the seedlings. The controller 100 acquires the starting position of the straight-line travel as a reference start point (point A), which is the start reference point. The controller 100 also acquires the ending position of the straight-line travel as a final reference end point (point B), which is the end reference point.

The controller 100 sets the position where the reference line setting switch 48 is turned "ON," i.e., the position where the reference line setting switch 48 is changed from "OFF" to "ON," as the reference start point. The method for setting the final reference end point will be described later. The reference line setting switch 48 may include switches for setting the reference start point and the final reference end point.

The controller 100 then stores the line segment connecting the reference start point (point A) and the final reference end point (point B) as reference line R0.

The reference start point and reference end point include information about direction and location. That is, the reference line R0 includes information about direction and location. Furthermore, the straight-ahead driving path R1 includes information about direction and location.

The reference line R0 is updated when the reference start point (point A) and the final reference end point (point B) for straight-ahead driving are updated. Furthermore, the straight-ahead driving path R1 in the next process is set parallel to the updated reference line R0.

Next, the drive control of the seedling planting device 55 according to the embodiment will be described with reference to Figure 6. Figure 6 is a flowchart illustrating the drive control of the seedling planting device 55 according to the embodiment.

The drive control of the seedling planting device 55 described below is performed when the seedling planting unit 4 has been lowered to a predetermined lowered position.

The controller 100 calculates the first vehicle speed (S100). The controller 100 calculates the first vehicle speed based on information related to the position of the traveling vehicle body 2. Specifically, the controller 100 acquires information related to 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.

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

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 of the first and second vehicle speeds from the larger one. The controller 100 then determines whether the difference between the first vehicle speed and the second vehicle speed is equal to or greater than a predetermined value. The predetermined value is a vehicle speed at which it can be determined that the traveling vehicle body 2 has slipped in the field. In other words, the controller 100 determines whether the traveling vehicle body 2 is slipping.

The controller 100 determines that the traveling vehicle body 2 is slipping if the difference between the first vehicle speed and the second vehicle speed is equal to or greater than a predetermined value. Furthermore, the controller 100 determines that the traveling vehicle body 2 is not slipping if the difference between the first vehicle speed and the second vehicle speed is less than a predetermined value.

If the controller 100 determines that the difference between the first vehicle speed and the second vehicle speed is less than a predetermined value and that the traveling vehicle body 2 is not slipping (S102: No), it engages the planting clutch 27a (S103). That is, the controller 100 switches the transmission state of the power generated by the engine 30 to the seedling planting device 55 to the on state, and switches the state in which the externally extracted power extracted from the transmission case 13 is transmitted to the seedling planting device 55. As a result, the externally extracted power extracted from the transmission case 13 is transmitted to the seedling planting device 55, and the planting rotary 57 rotates using the externally extracted power extracted from the transmission case 13.

If the controller 100 determines that the difference between the first vehicle speed and the second vehicle speed is equal to or greater than a predetermined value and that the traveling vehicle body 2 is slipping (S102: Yes), it disengages the planting clutch 27a (S104). That is, the controller 100 cuts off the transmission of power generated by the engine 30 to the seedling planting device 55, and prevents the externally extracted power extracted from the transmission case 13 from being transmitted to the seedling planting device 55.

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 rotation speed (rotational speed) of the rotary shaft of the planting motor 110 based on the first vehicle speed so that the seedling planting device 55 plants seedlings in the field at a predetermined spacing between plants. As a result, power is transmitted from the planting motor 110 to the seedling planting device 55, and the planting rotary 57 rotates using the power generated by the planting motor 110.

In this way, when the controller 100 detects slippage of the traveling vehicle body 2, it controls the planting motor 110 based on the first vehicle speed, thereby allowing the seedling planting device 55 to perform planting in accordance with the movement of the traveling vehicle body 2. Therefore, even if the traveling vehicle body 2 slips, fluctuations in the spacing between plants due to slippage are suppressed.

Next, the reference end point setting control according to the embodiment will be described with reference to Figure 7. Figure 7 is a flowchart illustrating the reference end point setting control according to the embodiment.

The controller 100 determines whether the reference start point (point A) has been set (S200). Specifically, the controller 100 determines whether the reference line setting switch 48 has been changed from "OFF" to "ON." The controller 100 determines that the reference start point has been set if the reference line setting switch 48 has been changed from "OFF" to "ON."

If the reference start point has not been set (S200: No), i.e., if the reference line setting switch 48 is kept "OFF," the controller 100 ends this processing.

When the reference start point has been set (S200: Yes), the controller 100 determines whether the operator has performed a manual termination operation 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." The controller 100 determines that a manual termination operation has been performed when the reference line setting switch 48 has been changed from "ON" to "OFF."

When a manual termination operation is 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.

If a manual termination operation has not been performed (S201: No), the controller 100 determines whether a turning operation has started (S203). For example, the controller 100 determines that a turning operation has started when the planting unit lift switch 47 is changed to the "up" position. The controller 100 may also determine that a turning operation has 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 preset value that allows determination that the traveling vehicle body 2 has started turning.

If a turning operation has not been initiated (S203: No), the controller 100 measures the distance traveled by the traveling vehicle body 2 (S204). Specifically, the controller 100 measures the distance traveled by 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 yet started measuring the distance traveled by the traveling vehicle body 2, the controller 100 starts measuring the distance traveled. For example, the controller 100 starts measuring the distance traveled immediately after the reference start point is set.

Next, the controller 100 determines whether the measured travel distance of the traveling vehicle body 2 is equal to or greater than a predetermined distance (S205). The predetermined distance is a preset distance, for example, 5 m.

If the travel 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 processing.

If the travel distance of the traveling vehicle body 2 is equal to or greater than a 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 each time the traveling vehicle body 2 travels a predetermined distance. In other words, the controller 100 updates the reference end point each time the traveling vehicle body 2 travels a predetermined distance. In this way, the controller 100 automatically sets the reference end point.

Next, the controller 100 resets the measured movement distance (S207). After resetting the movement distance, the controller 100 returns to step S201 and repeats the above process. Note that if the process proceeds to step S204 after the movement distance is reset, measurement of the movement distance will begin again.

When a turning operation is initiated (S203: Yes), the controller 100 sets the current reference end point as the final reference end point (point B) (S206). This allows the final reference end point to be automatically set when a turning operation is initiated, even if the operator forgets to turn the reference line setting switch 48 "OFF."

If a manual termination operation is performed when the reference end point has been automatically set, the automatically set reference end point is reset (deleted), and the position of the traveling vehicle body 2 at the time of the manual termination operation is set as the final reference end point. Furthermore, if a manual termination operation is performed while the travel distance is being measured, or if a turning operation is initiated while the travel distance is being measured, the travel distance is reset.

The above-mentioned predetermined distance may also be configurable. For example, the predetermined distance may be set by the worker. The worker can set the predetermined distance to suit the field, for example.

The seedling transplanter 1 comprises 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 to rotate the front wheels 10 and 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 slippage of the traveling vehicle body 2 is not detected, the controller 100 switches the transmission state to the on state and drives the seedling planting device 55 with the power generated by the engine 30. When slippage of the traveling vehicle body 2 is detected, the controller 100 cuts off the transmission and drives the seedling planting device 55 using the power generated by the planting motor 110.

As a result, even if the traveling body 2 of the seedling transplanter 1 slips, the planting motor 110 can drive the seedling planting device 55 to plant the seedlings in the field, preventing a decrease in work accuracy.

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 power generated by the engine 30 to the seedling planting device 55. The second planting transmission shaft 111 transmits power generated by the planting motor 110 to the seedling planting device 55.

This allows the seedling transplanter 1 to transmit power from the engine 30 and the planting motor 110 to the seedling planting device 55 via different paths. As a result, the seedling transplanter 1 can prevent the power transmission paths from the engine 30 and the planting motor 110 to the seedling planting device 55 from becoming complicated, thereby preventing costs from increasing.

The seedling transplanter 1 is equipped with a position detection device 150 and a rotation speed sensor 90. The position detection device 150 detects information related to the position of the traveling body 2. The rotation speed sensor 90 detects the rotation speed of the rear wheels 11. The controller 100 detects slippage of the traveling body 2 when the difference between a first vehicle speed calculated based on information related to the position of the traveling body 2 and a second vehicle speed calculated based on the rotation speed is equal to or greater than a predetermined value. If the controller 100 does not detect slippage of the traveling body 2, it does not drive the planting motor 110.

This allows the seedling transplanter 1 to reduce the power consumed by the planting motor 110 when no slippage is detected.

When the controller 100 detects slippage of the traveling vehicle body 2, it controls the planting motor 110 based on the first vehicle speed, causing the seedling planting device 55 to perform planting.

As a result, even if the traveling body 2 slips, the seedling transplanter 1 can plant seedlings in the field in accordance with the actual movement of the traveling body 2, and the spacing between the plants can be kept uniform. Therefore, even if the traveling body 2 slips, the seedling transplanter 1 can use the seedling mat in the field as planned. Furthermore, the seedling transplanter 1 can prevent the spacing between plants from being too narrow, i.e., the seedlings from being planted too closely, improving seedling growth.

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

This allows the seedling transplanter 1 to charge the storage battery 112 while driving the seedling planting device 55 using power generated by the engine 30.

The seedling transplanter 1 is equipped with a fertilizer applicator 5. The fertilizer applicator 5 is mounted on the traveling vehicle body 2 and supplies fertilizer to the field. The fertilizer applicator 5 is equipped with a delivery motor 71a that drives a delivery unit that delivers fertilizer from the fertilizer hopper 70. The delivery motor 71a is supplied with power from a storage battery 112.

This allows the seedling transplanter 1 to efficiently use the electricity generated by the planting motor 110.

The seedling transplanter 1 is equipped with 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 performs automatic straight-line driving. The controller 100 updates the reference end point (point B) each time the traveling vehicle body 2 travels a predetermined distance.

As a result, when setting the reference line R0, which serves as the driving reference for automatic straight-line driving, the seedling transplanter 1 can automatically set the reference end point to match the straight-line driving of the traveling vehicle body 2. Furthermore, by updating the reference end point, the seedling transplanter 1 can set the reference line R0 to be longer to match the driving of the traveling vehicle body 2 when the straight-line driving required to set the reference line R0 becomes longer. As a result, the seedling transplanter 1 can improve the accuracy of the reference line R0.

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.

This allows the seedling transplanter 1 to set the final reference end point in accordance with the operator's operation. For example, even if the seedling transplanter 1 automatically sets the reference end point, it can prioritize the operator's operation and set the position where the manual end operation was performed as the final reference end point.

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

This allows the seedling transplanter 1 to set the final reference end point even if, for example, the operator forgets to turn the reference line setting switch 48 to "OFF."

The seedling transplanter 1 in this modified example may have the following configuration, etc.

The seedling transplanter 1 may be provided with a clutch on the second planting transmission shaft 111. The clutch is disengaged when the planting motor 110 is not driving the seedling planting device 55. In other words, the clutch is disengaged when the traveling body 2 is not slipping. The clutch is engaged when the planting motor 110 is driving the seedling planting device 55. In other words, the clutch is engaged when the traveling body 2 is slipping. The clutch is engaged and disengaged by a solenoid or the like.

In this way, when the traveling body 2 is slipping, the seedling transplanter 1 engages the clutch and drives the seedling planting device 55 with the planting motor 110. When the traveling body 2 is not slipping, the seedling transplanter 1 disengages the clutch, thereby reducing the load on the engine 30.

When the seedling transplanter 1 sets the reference start point (point A), it displays on the monitor 86 that it is acquiring the reference end point (point B). This allows the seedling transplanter 1 to inform the operator that the reference end point is being acquired.

When the seedling transplanter 1 sets a reference end point (point B) after setting a reference start point, i.e., when the traveling vehicle body 2 moves a predetermined distance and automatically sets the reference end point, the monitor 86 displays that the reference end point has been set. This allows the seedling transplanter 1 to inform the operator that the reference end point has been set.

When a manual termination operation is performed and the final reference end point (point B) is set, the seedling transplanter 1 stops the above display on the monitor 86. In other words, the seedling transplanter 1 stops displaying on the monitor 86 that the reference end point (point B) is being acquired, or that the reference end point has been set.

The seedling transplanter 1 may be able to change the reference start point and final reference end point after setting the reference line R0, i.e., after setting the reference start point (point A) and final reference end point (point B). For example, the monitor 86 displays the reference line R0, including the reference start point and the final reference end point. The operator can change the reference start point and the final reference end point by manipulating the reference start point and the final reference end point displayed on the monitor 86. For example, the operator can extend the reference line R0 by changing the final reference end point.

This allows the worker to set the reference line R0 to match the actual field. For example, if 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 worker can change the reference start point or the final reference end point to set the reference line R0 to match the length of the other path.

After setting the reference line R0, the seedling transplanter 1 can add information about the shape of the field. For example, as shown in Figure 8, if part of the field is concave in plan view, position information for the concave shape can be set. Figure 8 is a diagram showing the path that the seedling transplanter 1 automatically follows in a straight line in a field with a concave shape.

The seedling transplanter 1 may also be able to change the distance of the straight travel path R1 from the reference line R0 after setting the reference line R0. The seedling transplanter 1 may also be able to set an area in the field where the straight travel path R1 is to be changed. In other words, the seedling transplanter 1 may be able to set the distance (width) by which the length of the straight travel path R1 is changed in a direction perpendicular to the straight travel path R1 (left-right direction). For example, the area where the straight travel path R1 is to be changed is set by inputting position information for the area where the straight travel path R1 is to be changed.

For example, the operator can set a straight driving route R1-1 that is shorter in distance than the straight driving route R1 set according to the reference line R0, in accordance with the shape of the field. For example, the monitor 86 or a terminal device displays the shape of the field, the reference line R0, the straight driving route R1, etc., allowing the operator to set the straight driving route R1-1 while checking the display screen. This allows the operator to easily set the straight driving routes R1, R1-1 according to the shape of the field.

The seedling transplanter 1 may also be capable of automatically traveling straight across a concave area A (e.g., a ridge), as shown in Figure 9. Figure 9 is a diagram showing a path along which the seedling transplanter 1 automatically travels straight in a concave field. Note that area A can be set after setting the reference line R0. For example, area A is set by inputting position information for area A. Area A may also be set by distance. For example, area A may be set by the distance along the straight travel path R1 and the distance in a direction perpendicular to the straight travel path R (left-right direction).

When traveling through area A, the seedling transplanter 1 raises the seedling planting unit 4 to a predetermined raised position. This prevents the seedling planting unit 4 from coming into contact with ridges, etc., when traveling through area A. The seedling transplanter 1 may also be able to set a vehicle speed for area A when traveling through area A. The seedling transplanter 1 may also be able to set a judgment value for preventing the traveling body 2 from tipping over when traveling through area A. For example, the seedling transplanter 1 executes safety control, such as stopping the traveling body 2, when the tilt angle of the traveling body 2 exceeds the judgment value.

In addition, when traveling through area A, the seedling transplanter 1 may cancel automatic straight-line travel and switch to manual operation. Furthermore, when entering area A, the seedling transplanter 1 may ask the operator whether to switch from automatic straight-line travel to manual operation, allowing the operator to choose whether to travel through area A using automatic straight-line travel or manual operation.

The seedling transplanter 1 determines whether it is possible to travel through 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, and the inclination angle of the traveling vehicle body 2 detected by the inclination sensor 92.

If the seedling transplanter 1 cannot travel automatically through area A, it switches to manual operation. If the seedling transplanter 1 cannot travel automatically through area A, it may bypass area A, set a route that can be traveled automatically, and travel automatically along the set route. If the seedling transplanter 1 cannot travel automatically through area A, it may stop the traveling vehicle body 2. The seedling transplanter 1 may allow the operator to select whether to travel automatically along the set route or to stop the traveling vehicle body 2. Alternatively, a remote control that can remotely operate the seedling transplanter 1 may allow the operator to select whether to travel automatically along the set route or to stop the traveling vehicle body 2. Alternatively, the selection of whether to travel automatically along the set route or to stop the traveling vehicle body 2 may be displayed on the user's terminal device. In this case, various information is transmitted to the terminal device via a communication line circuit such as 5G, for example.

Further advantages and modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

1. Seedling transplanter (work vehicle)
2 Traveling vehicle body 4 Seedling planting unit 5 Fertilizer application device 10 Front wheel (drive wheel)
11 Rear wheels (drive wheels)
27a Planting clutch (clutch)
30 Engine (power source)
35 Handle 55 Seedling planting device (planting device)
67 First planting transmission shaft (first drive shaft)
70 Fertilizer hopper (fertilizer tank)
71a: Feed motor 90: Rotation speed sensor 95: Steering motor
100 Controller (control device)
110 Planting motor (motor)
111 Second planting transmission shaft (second drive shaft)
112 Storage battery 150 Position detection device

Claims (11)

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,
The control device
When slippage of the traveling vehicle body is not detected, the transmission state is switched to an ON state to drive the planting device using the power generated by the drive source;
When slippage of the traveling vehicle body is detected, the transmission state is switched off and the planting device is driven by the power generated by the motor. A first drive shaft that transmits power generated by the drive source to the planting device;
The work vehicle according to claim 1 , further comprising: a second drive shaft that transmits power generated by the motor to the planting device. 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,
The control device
detecting the slip when a difference between a first vehicle speed calculated based on the information relating to the position of the traveling vehicle body and a second vehicle speed calculated based on the number of revolutions is equal to or greater than a predetermined value;
The work vehicle according to claim 1 , wherein the motor is not driven when the slip is not detected. The work vehicle described in claim 3, wherein, when the control device detects the slip, the control device controls the motor based on the first vehicle speed and causes the planting device to perform planting. The motor functions as a generator when the planting device is driven by the power generated by the drive source,
The work vehicle according to claim 1 , wherein the electric power generated by the motor is stored in a storage battery. a fertilizer applicator provided on the traveling vehicle body and configured to supply fertilizer to the field;
The fertilizer application device is
a delivery motor that drives a delivery unit that delivers fertilizer from the fertilizer tank,
The work vehicle according to claim 5 , wherein the payout motor is supplied with power from the storage battery. A handle provided on the traveling vehicle body;
a steering motor that drives the steering wheel when the traveling vehicle body performs automatic straight traveling;
The control device
The work vehicle according to claim 1 , wherein a reference end point of a reference line that serves as a travel reference for the automatic straight-line travel is updated every time the traveling vehicle body travels a predetermined distance. The work vehicle described in claim 7, wherein the predetermined distance is variable. The work vehicle described in 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 was performed as the final reference end point. The work vehicle described in claim 7, wherein the control device sets the current reference end point as the final end point when the turning operation of the traveling vehicle body is initiated without the operator having performed an operation to set the reference end point. A work vehicle as described in 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.