JP2022098846A - Work vehicle - Google Patents

Abstract

To provide a work vehicle capable of travelling stably by automated travelling even when a state of a farm field is bad.SOLUTION: A work vehicle that can execute automated travelling includes: a steering device for steering right and left travelling wheels; an actuator for driving the steering device; position information acquisition means for acquiring position information on the vehicle; a differential gear for distributing driving force to axles of the right and left travelling wheels; a controller for controlling permission and restriction of differential rotation of the right and left axles by the differential gear; and a work machine provided at the rear part of the vehicle, which can be elevated and lowered. When the travelling wheels are idling, the controller restricts the differential rotation of the right and left axles.SELECTED DRAWING: Figure 13

Description

The present invention relates to a work vehicle such as a rice transplanter.

Conventionally, work vehicles such as rice transplanters and combines that automatically repeat straight running and turning are known in the field.

For example, Patent Document 1 discloses a work vehicle that automatically steers a steering handle and automatically travels in a field based on position information (position coordinates) acquired by a GNSS (Global Navigation Satellite System) receiver. ..

The work vehicle described in Patent Document 1 is provided with a differential mechanism (differential device), and is located on the outer side of the left and right traveling wheels based on the load applied to each of the left and right traveling wheels when turning. A large amount of driving force (torque) is distributed to the traveling wheel located on the inner side, and the number of rotations of the traveling wheel located on the inner side is suppressed, so that the vehicle can turn smoothly.

JP-A-2018-117564

However, when the work vehicle is traveling, if the condition of the field is poor and one of the left and right traveling wheels is slipping (slip), the differential mechanism functions and the rotation of the other traveling wheel that is not idling. In a state where the number is suppressed, the driving force is transmitted to one of the spinning wheels, which may be difficult to drive.

Further, as described above, when one of the left and right traveling wheels idles, the traveling wheels continue to idle at the same place, so that there is a problem that the field becomes rough.

Therefore, an object of the present invention is to provide a work vehicle capable of stably traveling by automatic traveling even when the condition of the field is bad.

Such an object of the present invention is
A steering device that steers the left and right running wheels,
The actuator that drives the steering device and
Location information acquisition means to acquire vehicle location information,
A differential device that distributes the driving force to the axles of the left and right traveling wheels,
A controller that controls the tolerance and limitation of the differential rotation of the left and right axles by the differential device,
It is a work vehicle that can run automatically and is equipped with a work machine that can be raised and lowered provided at the rear of the vehicle.
When the traveling wheel is idling, the controller is achieved by a work vehicle characterized by limiting the differential rotation of the left and right axles.

According to the present invention, when the traveling wheels are idling while the work vehicle is traveling, the differential rotation of the axles of the left and right traveling wheels is restricted. Of the traveling wheels of the above, it is possible to prevent the situation where the driving force (torque) is continuously transmitted due to the uneven weight on the idling traveling wheels, and the driving force can be sufficiently transmitted to the traveling wheels that are not idling. The vehicle can run stably by automatic running.

In a preferred embodiment of the invention
When there is an output from the hydrostatic continuously variable transmission that changes the rotational speed of the traveling wheels and the position information of the vehicle acquired by the position information acquisition means has not changed, the controller , It is determined that the traveling wheel is idling, and the differential rotation of the left and right axles is restricted.

According to this preferred embodiment of the present invention, there is an output from the hydrostatic continuously variable transmission in limiting the differential rotation of the left and right axles, and the position (position information, position coordinates) of the work vehicle. By making a total of two points that have not changed, it is possible to prevent a situation in which the differential rotation of the left and right axles is accidentally restricted when it is not necessary.

In a more preferred embodiment of the invention
When the vehicle is turning, if the ratio of the higher rotation speed to the lower rotation speed of the left and right axle rotation speeds within a predetermined time is equal to or more than a predetermined value, the controller runs. It is determined that the wheels are idling, and the differential rotation of the axles of the left and right traveling wheels is restricted.

According to this preferred embodiment of the present invention, even when the position information acquisition means composed of a GNSS receiver or the like does not function due to radio wave conditions or the like, the number of rotations of the axles of the left and right traveling wheels is detected. By calculating the ratio, it is possible to detect the idling of the traveling wheels.

Further, according to this preferred embodiment of the present invention, the idling of the traveling wheels can be detected only by detecting the rotation speeds of the axles of the left and right traveling wheels and calculating the ratio thereof, so that the configuration can be simplified. can do.

In a more preferred embodiment of the invention
The traveling wheel is a front wheel.
If the position information of the vehicle acquired by the position information acquisition means has not changed after the differential rotation of the axles of the left and right front wheels is restricted, the controller is further transmitted to the rear wheels. It is a clutch that can be switched between the state and the disengaged state that is not transmitted to the rear wheels, and the clutch that is in the disengaged state is switched to the on state.

According to this preferred embodiment of the present invention, when the position of the vehicle has not changed even though the left and right front wheel axles are diff-locked, the rear wheel clutch in which the transmission of the driving force is cut off is engaged. Since it is configured to be in a state, it is possible to eliminate the idling of the front wheels by using the traction force of both the left and right rear wheels.

In a more preferred embodiment of the invention
If the position of the vehicle acquired by the position information acquisition means has not changed after the clutch in the disengaged state is switched to the on state, the controller further advances the steering device straight by the actuator. Steer to the position and lower the work machine to a work position where work is possible.

According to this preferred embodiment of the present invention, if the position of the work vehicle does not change even after the rear wheel clutch is switched to the engaged state, the steering device is steered to the straight-ahead position, so that the front wheels slip. It is possible to easily eliminate the state.

Further, according to this preferred embodiment, by lowering the work equipment to the work position, a part of the power of the work vehicle is directed toward traveling without being devoted (directed) to the purpose of continuing to lift the work equipment. Can be increased to facilitate the elimination of the idling state of the front wheels.

In a more preferred embodiment of the invention
The controller determines whether or not the vehicle deviates from the work area if the vehicle travels a predetermined distance while the steering device is steered to a straight-ahead position and the work machine is lowered to the work position. As a result of the determination, the output is output from the hydrostatic continuously variable transmission only when the work area is not deviated.

According to this preferred embodiment of the present invention, the controller is static only when the work vehicle does not deviate from the work area as a result of determining whether or not the work vehicle deviates from the work area when the work vehicle travels a predetermined distance. Since it is configured to output from a hydraulic continuously variable transmission and run, safety can be ensured and the aircraft can be protected.

According to the present invention, it is possible to provide a work vehicle capable of stably traveling by automatic traveling even when the condition of the field is poor.

FIG. 1 is a substantially left side view of a seedling transplanting machine according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view of the seedling transplanting machine shown in FIG. FIG. 3 is a schematic plan view showing a transmission mechanism in the vicinity of the mission case of the seedling transplanter shown in FIG. FIG. 4A is a partial plan view in the vicinity of the hydrostatic continuously variable transmission, and FIG. 4B is a partial side view in the vicinity of the hydrostatic continuously variable transmission. FIG. 5 is a block diagram of a control system, a detection system, an input system, a display system, and a drive system of the seedling transplanter shown in FIG. 6 (a) is an exploded perspective view of the upper part of the steering mechanism of the seedling transplanter shown in FIG. 1, and FIG. 6 (b) is a horizontal sectional view of the vicinity of the internal gear of the steering mechanism. FIG. 7 is a schematic plan view showing a route on which the seedling transplanter automatically travels in the field. FIG. 8 is an explanatory diagram showing a flow from when the seedling transplanter automatically starts turning to when the front wheels slip. FIG. 9 is a flowchart showing a control flow until the controller detects the idling of the traveling wheel while the seedling transplanting machine shown in FIG. 1 is automatically traveling and further eliminates the idling. FIG. 10 is an explanatory diagram showing an increase / decrease in the number of rotations of the left and right front wheels when the seedling transplanting machine shown in FIG. 1 turns in a field having different hardness. FIG. 11 is a flowchart for controlling the increase in the engine speed when the automatic running start operation is performed in the seedling transplanting machine shown in FIG. 1. FIG. 12 is a drawing relating to the control of the steering motor shown in FIG. 6 (a). FIG. 13 is a flowchart showing a flow of control regarding detection and elimination of idling of traveling wheels by a controller after the seedling transplanting machine according to another preferred embodiment of the present invention is energized. FIG. 14 is a block diagram of a control system, a detection system, an input system, a display system, a drive system, and a communication system of a seedling transplanter according to another preferred embodiment of the present invention. FIG. 15 is a flowchart showing a control flow until the controller detects the idling of the traveling wheel and further eliminates the idling of the traveling wheel when the seedling transplanting machine shown in FIG. 14 turns by automatic traveling.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a substantially left side view of the seedling transplanting machine 1 according to a preferred embodiment of the present invention, and FIG. 2 is a schematic plan view of the seedling transplanting machine 1 shown in FIG.

In the present specification, as shown by arrows in FIGS. 1 and 2, the side facing the traveling direction of the seedling transplanting machine 1 (an example of the work vehicle according to the present invention) is the front, and unless otherwise specified, the seedlings are seedlings. The left side of the transplanting machine 1 in the direction of travel is called "left", and the opposite side is called "right".

As shown in FIGS. 1 and 2, the seedling transplanting machine 1 according to the present embodiment includes a traveling vehicle 2 and a seedling planting portion 63 attached to the rear portion of the traveling vehicle 2 (an example of a working machine according to the present invention). ) Is provided.

As shown in FIG. 1, the traveling vehicle 2 is attached to a main frame 3 arranged substantially in the center of the traveling vehicle 2 and a rear end portion of the main frame 3, and extends in the width direction of the seedling transplanting machine 1. 6 is provided with a pair of left and right front wheels 8 (steering wheels) and a pair of left and right rear wheels 9 (see FIG. 2) as traveling wheels (driving wheels).

As shown in FIGS. 1 and 2, a floor step 60 is provided above the main frame 3, and above the floor step 60, a front cover 47 arranged at the front of the traveling vehicle 2 and a front surface are provided. A control unit 49 arranged behind the cover 47, a controller 87 (see the left side of the drawing in FIG. 1, control unit) covered with the front cover 47 and controlling the seedling transplanting machine 1, and a control unit 49 arranged behind the control unit 49. There is also a driver's seat 48.

In the seedling transplanting machine 1 according to the present embodiment, the controller 87 automatically performs straight running at the center of the field and turning running at the edge of the field (near the shore) (hereinafter, seedling transplanting machine). The state in which 1 automatically travels based on the control of the controller 87 is referred to as "automatic traveling"), and the state in which the seedling transplanting machine 1 travels based on the operator's control (hereinafter, the seedling transplanting machine 1 travels based on the operator's control). This is called "manual driving") and is configured to be switchable. In the case of manual driving, the controller 87 is configured to be able to execute straight-ahead assist that automatically controls the steering angle of the steering handle 56 when traveling straight-ahead.

The control unit 49 automatically sets the running state of the seedling transplanting machine 1, the steering mechanism 66 including the steering handle 56 that steers the pair of left and right front wheels 8, the forward / backward lever 35 that moves the traveling vehicle 2 forward, backward, or stops. It is equipped with an automatic traveling lever 79 that switches between traveling and manual traveling.

The automatic traveling lever 79 is used when acquiring the position information of the seedling transplanting machine 1 by using the GNSS receiver 130 provided at the front of the seedling transplanting machine 1, and when starting and stopping the automatic traveling and straight-ahead assist. Be manipulated.

As shown in FIGS. 1 and 2, a fertilizer application device 26 for supplying fertilizer to the field is provided behind the cockpit 48.

As shown in FIG. 1, the fertilization device 26 includes a fertilization hopper 27 for storing fertilizer, a feeding device 34 for feeding out the fertilizer in the fertilizing hopper 27 downward, and a fertilization hose 40 for supplying the fed fertilizer to the field. I have.

As shown in FIG. 1, a central leveling rotor 31 is provided behind the rear wheel 9, and a pair of left and right leveling rotors 32 are provided behind the central leveling rotor 31.

FIG. 3 is a schematic plan view showing a transmission mechanism in the vicinity of the mission case 30 of the seedling transplanting machine 1 shown in FIG.

Further, FIG. 4A is a partial plan view in the vicinity of the hydrostatic continuously variable transmission 25, and FIG. 4B is a partial side view in the vicinity of the hydrostatic continuously variable transmission 25.

As shown in FIG. 1, an engine 7 is provided below the driver's seat 48, and the driving force output from the engine 7 is a belt-type power transmission mechanism 4 provided below the floor step 60 and static. After being transmitted to the mission case 30 via the hydraulic continuously variable transmission 25 (also referred to as HST, also see FIG. 3), the speed is changed by the auxiliary transmission mechanism 20 (see FIG. 3) in the transmission case 30 to make a pair of left and right. The power for traveling to the front wheels 8 and the pair of left and right rear wheels 9 and the power for driving the seedling planting portion 63 (power for driving) are transmitted separately.

As shown in FIG. 3, the hydrostatic continuously variable transmission 25 includes a trunnion shaft 120, and the output to the transmission case 30 can be adjusted by controlling the opening degree of the trunnion shaft 120. There is.

For example, when it is necessary to adjust the traveling speed of the traveling vehicle 2 as in the case where the forward / backward lever 35 shown in FIG. 2 is operated, the controller 87 controls the HST servomotor shown in FIG. 4 (b). The 150 is driven and the rotation angle of the trunnion arm 121 is changed via the gear 124 with the lining and the rod 123 shown in FIGS. 4 (a) and 4 (b).

As a result, the opening degree of the trunnion shaft 120 shown in FIG. 3 becomes large or small, and the traveling vehicle 2 accelerates, decelerates, or stops. At this time, the rotation of the traveling wheels 8 and 9 is accelerated, decelerated, or stopped. In this embodiment, the controller 87 is based on the positions of the potentiometer 122 and the forward / backward lever 35 (detection signal of the forward / backward lever sensor) for detecting the rotation angle of the tranny arm 121 shown in FIG. 4 (b). , Determines the drive range of the HST servomotor 150.

After being output from the hydrostatic continuously variable transmission 25, the running power (torque) shifted by the auxiliary transmission mechanism 20 shown in FIG. 3 is a differential mechanism based on the difference in load applied to the left and right front wheels 8. It is distributed to the left and right front wheel axles 17 and 18, respectively by 15 (corresponding to the differential device of the present invention), and is transmitted to the pair of left and right front wheels 8 via the front wheel final case 13 (see FIG. 1). That is, the left and right front wheel axles 17 and 18 are configured to be rotatable at different rotation speeds based on the difference in the load applied to the left and right front wheels 8 (hereinafter, the left and right front wheel axles 17 and 18 or the left and right traveling wheels). When 8 and 9 are rotated at different rotation speeds between the left and right, it is called "differential rotation").

Further, in the present embodiment, the differential mechanism 15 has a diff lock function, and the diff lock motor 16 shown in FIG. 3 is driven to cause a difference in the rotation speeds of the left and right front wheel axles 17 and 18. It is configured to be preventable (hereinafter, by using the diff lock function, making the left and right front axles 17 and 18 have the same number of rotations is "restricting differential rotation", "deflocking" or "activating the diff lock". It is called "allowing differential rotation" or "releasing the diff lock" to allow a situation in which the rotation speeds of the left and right front wheel axles 17 and 18 are opened by the differential mechanism 15.).

Specifically, as shown in FIG. 3, a diff lock arm 19 is attached to the diff lock motor 16, and when the diff lock motor 16 is driven, the on / off pin 22 connected to the diff lock arm 19 moves. The differential clutch 23 is engaged, and as a result, the differential rotation of the left and right front wheel axles 17 and 18 is restricted.

Therefore, even though one of the left and right front wheels 8 is idling, the driving force is transmitted only to the idling front wheel 8 among the pair of left and right front wheels 8 to prevent the seedling transplanting machine 1 from becoming difficult to run. can do.

Further, the power transmitted to the pair of left and right rear wheels 9 is taken out from the rear part of the mission case 30, and then the pair of left and right rear wheel transmission shafts 14, the pair of left and right rear wheel gear cases 51, and the axles shown in FIG. It is transmitted to the pair of left and right rear wheels 9 via 82 (see FIG. 1).

As described above, the traveling wheels 8 and 9 are rotated by the power transmitted from the engine 7, and the traveling vehicle 2 moves forward or backward.

In this embodiment, a side clutch (not shown, also referred to as a rear wheel clutch) that transmits (transmits) the driving force to the left and right rear wheel axles 82 is provided, and the seedling transplanting machine 1 turns. At that time, the side clutch of the rear wheel 9 located inside is disengaged (switched to the disengaged state). With this configuration, it is possible to make a smooth and small turn without damaging the field.

Further, a part of the driving force transmitted to the rear wheel gear case 51 is transmitted to the fertilization device 26.

Further, the rotational power of the engine 7 is transmitted to a hydraulic pump (not shown), and the hydraulic pump drives and rotates in proportion to the rotation speed of the engine 7, and the power steering of the steering mechanism 66 (see FIG. 1) (see FIG. 1). (Not shown in FIGS. 1 to 4), hydraulic pressure is supplied to the hydrostatic stepless transmission 25, the elevating hydraulic cylinder 12 (see FIG. 1), and the like.

On the other hand, the driving power is transmitted to a planting clutch (not shown) provided at the rear of the traveling vehicle 2, and is transmitted to the seedling planting unit 63 when the planting clutch is engaged.

As shown in FIG. 1, the seedling planting portion 63 is connected to the traveling vehicle 2 via the elevating link device 5. The elevating link device 5 includes an upper link arm 85 and a pair of left and right lower link arms 86, and is configured to be able to elevate the seedling planting portion 63.

The front ends of the upper link arm 85 and the lower link arm 86 are attached to the link base frame 10 fixed to the rear frame 6, and the other end is attached to the upper and lower link arms 11 located at the lower part of the seedling planting portion 63. Has been done.

The controller 87 is configured to control an electro-hydraulic valve (not shown in FIGS. 1 to 3), the electro-hydraulic valve is controlled by the controller 87, and the elevating hydraulic cylinder 12 (see FIG. 1) is hydraulically contracted. Then, the upper link arm 85 is rotated and the seedling planting portion 63 is raised to the non-working position. Further, when the elevating hydraulic cylinder 12 is hydraulically extended, the upper link arm 85 is rotated, and the seedling planting portion 63 is lowered to a work position where seedling planting work is possible. When the seedling planting portion 63 is in the non-working position, its lower end is located at substantially the same height as the bottom of the main frame 3, and when the seedling planting portion 63 is in the working position, its lower end is located. Ground.

As shown in FIGS. 1 and 2, the seedling planting section 63 is provided with a table 65 on which a mat-shaped seedling with soil (hereinafter referred to as “seedling mat”) is leaned against, and behind and below the table 65. It is provided with three planting devices 64, a center float 38 provided at the lower part of the seedling planting portion 63, and a pair of left and right side floats 39 arranged on the left and right sides of the center float 38.

As shown in FIG. 2, three planting devices 64 are provided side by side in the width direction of the seedling transplanting machine 1, and each planting device 64 includes two pairs of left and right planting tools 69 arranged in the front-rear direction. When the drive shaft 67 shown in FIG. 1 is rotated, the front planting tool 69 and the rear planting tool 69 shown in FIGS. 1 and 2 are alternately rotated around the drive shaft 67. The seedlings located at the lower end of the table 65 are taken out and planted in the field.

The center float 38 and the pair of left and right side floats 39 each slide on the field as the seedling transplanting machine 1 travels, and are configured to be able to level the ground, and are leveled by the center float 38 and the pair of left and right side floats 39. Seedlings are planted in the field using each planting device 64. The front portions of the center float 38 and the pair of left and right side floats 39 are configured to be swingable according to the unevenness of the field.

As shown in FIGS. 1 and 2, a spare seedling mounting table 74 for accommodating a seedling mat to be replenished in the table 65 is provided at the front portion of the seedling transplanting machine 1 to support the preliminary seedling mounting table 74. It is attached to the traveling vehicle 2 via the frame 77.

FIG. 5 is a block diagram of a control system, a detection system, an input system, a display system, and a drive system of the seedling transplanting machine 1 shown in FIG.

As shown in FIG. 5, the control system of the seedling transplanting machine 1 includes a controller 87 that controls the operation of the seedling transplanting machine 1 as a whole, and a timer 105 that measures the time.

The controller 87 includes a processing unit 89 having a CPU (Central Processing Unit), a storage unit 93 having a ROM (Read Only Memory) and a RAM (Random Access Memory), and the storage unit 93 controls the seedling transplanting machine 1. Various programs and data are stored.

As shown in FIG. 5, the detection system of the seedling transplanter 1 includes a steering sensor 58 having an encoder (not shown) for detecting the steering angle of the steering handle 56 (an example of the steering device according to the present invention) and steering. A torque sensor 111 attached to the upper shaft 83 of the mechanism 66 (see FIG. 6A) to detect the input torque (steering amount at that time) to the steering handle 56, and the engine rotation to detect the rotation speed of the engine 7. A sensor 96, a link sensor 90 that detects the relative angle of the upper link arm 85 with respect to the link base frame 10, a GNSS receiver 130 that functions as a position information acquisition means and receives radio waves from an artificial satellite, and left and right front wheels. A front wheel rotation sensor 21 that counts the rotation speeds of the axles 17 and 18 (see FIG. 3), a rear wheel rotation sensor 29 that counts the rotation speeds of each of the left and right axles 82 connected to the pair of left and right rear wheels 9, and a center. By detecting the movement of the float sensor 33, the orientation sensor 80, and the differential lock arm 19 that detect the vertical position of the front part of the float 38, the differential lock (limitation of differential rotation) of the pair of front wheel axles 17 and 18 is mechanically applied. It is provided with a limit switch 59 for detecting the rotation angle of the tranny arm 121 and a potentiometer 122 for detecting the rotation angle of the tranny arm 121.

The float sensor 33 is provided on the front portion of the center float 38, and detects the vertical position of the front portion of the center float 38 when the front portion of the center float 38 is swung according to the unevenness of the field, and is a controller. It is configured to output to 87.

As shown in FIG. 5, the seedling transplanting machine 1 includes a control unit 49 that functions as an input system, and the control unit 49 moves forward / backward and forward / backward lever 35 for changing the vehicle speed of the seedling transplanting machine 1 (FIG. 1). And the forward / backward lever sensor 36 that detects the position of (see FIG. 2), the automatic driving changeover switch 78 (see FIG. 2) that switches between automatic driving and manual driving, and acquisition of position information, automatic driving, and straight travel. The automatic traveling lever sensor 81 for detecting the swinging operation of the automatic traveling lever 79 (see FIGS. 1 and 2) operated when starting and stopping the assist is provided.

In the present embodiment, the automatic traveling lever 79 can be swung up and down, and after being swung up or down in either direction, the spring automatically returns to the original up and down position. It is configured.

As shown in FIG. 5, the display system of the seedling transplanting machine 1 includes a monitor 61 that displays various information.

As shown in FIG. 5, the drive system of the seedling transplanting machine 1 includes a throttle motor 97 for adjusting the intake amount of the engine 7 provided below the cockpit 48 and a seedling planting portion 35 when the seedling planting portion 35 is moved up and down. The HST servo motor 150 that adjusts the opening degree of the electro-hydraulic valve 88 that expands and contracts the elevating hydraulic cylinder 12 and the tranny shaft 120 in the hydrostatic stepless transmission 25 to change the forward / backward movement and vehicle speed of the seedling transplanter 1. The steering motor 57 (an example of the "actuator" according to the present invention) for rotating the steering handle 56 and the differential clutch 23 (see FIG. 3) are turned on and off to perform differential rotation of the left and right front wheel axles 17 and 18. It includes a differential lock motor 16 that switches between an allowable state and a limiting state (diff lock), an electromagnetic valve 103 that turns on and off the side clutch of the rear wheel 9, and a power steering 108.

The controller 87 shown in FIG. 1 is configured to be able to calculate the current height (vertical position) of the seedling planting portion 35 based on the output signal from the link sensor 90.

In addition, the controller 87 controls the electro-hydraulic valve 88 based on the detection signal from the float sensor 33 to expand and contract the elevating hydraulic cylinder 12 shown in FIG. 1, and the seedling planting portion shown in FIG. By raising and lowering 63, the planting depth of seedlings in the field can be kept constant.

Further, the controller 87 is configured to display the diff lock status of the pair of front wheel axles 17 and 18 on the monitor 61 based on the detection signal of the limit switch 59. With this configuration, the operator can grasp the failure of the automatic diff lock by the controller 87, and can easily predict the behavior of the seedling transplanting machine 1 to ensure safety. can.

6 (a) is an exploded perspective view of the upper part of the steering mechanism 66 of the seedling transplanting machine 1 shown in FIG. 1, and FIG. 6 (b) is a horizontal sectional view of the vicinity of the internal gear of the steering mechanism 66. be.

As shown in FIG. 6A or FIG. 6B, the steering mechanism 66 is attached to an upper shaft 83 having a universal joint 107 (an example of a steering shaft according to the present invention) and an upper end portion of the upper shaft 83. On the steering handle 56, the internal gear 106 attached to the lower part of the upper shaft 83, the lower shaft 84, the power steering 108 attached to the lower shaft 84 and configured by the torque generator, and the upper part of the lower shaft 84. A fixed motor-side gear 109, a hub damper 110 mounted inside the internal gear 106, a steering motor 57 that rotationally drives the motor-side gear 109 (and steering handle 56), a gearbox 112, and a pitman arm. It also has a pair of left and right tie rods (not shown).

In the steering mechanism 66 according to the present embodiment, the steering handle 56 to the pitman arm are mechanically connected, and when the steering handle 56 is steered (torque is input), the torque sensor 111 (see FIG. 6). ) Detects the steering amount.

As a result, steering control, that is, adjustment of the directions of the left and right front wheels 8 is performed so that the input torque is increased by the power steering 108. When the seedling transplanting machine 1 is automatically traveling, the steering handle 56 is automatically steered by the steering motor 57. In this case, the motor side gear 109 is rotationally driven by the steering motor 57, and the rotation of the motor side gear 109 is transmitted to the steering handle 56 via the internal gear 106 and the upper shaft (steering shaft) 83.

In the present embodiment, when the input torque value (detected by the torque sensor 111) to the steering handle 56 is equal to or higher than a certain value while the seedling transplanting machine 1 is automatically traveling, the controller 87 reduces the torque. It is configured to drive the steering motor 57 in the direction, stop the automatic steering of the steering handle 56, and then switch to manual driving. With this configuration, the operator can operate the steering handle 56 with a strong force at the discretion of the operator and switch to manual driving. Since something is caught in the steering handle 56, the steering motor 57 automatically drives the motor in a direction in which the torque sensor value decreases when the input torque value is equal to or higher than a certain value. It may be configured to stop steering.

On the other hand, while the seedling transplanting machine 1 is manually traveling, the controller 87 drives the steering motor 57 in a direction in which the input torque value to the steering handle 56 decreases, and further, the input torque to the steering handle 56 ( It is configured to change the drive speed, drive time, and drive amount of the steering motor 57 according to the operation speed, time, and magnitude).

With this configuration, the operator can delicately operate the steering handle 56 with a weak force, and in addition, perform quick steering only when the steering handle 56 is rotated with a strong force. Can be done. The controller 87 may be configured to drive the steering motor 57 to assist the operator in torque input during manual driving, and the operator may turn on / off the drive of the steering motor 57. It may be configured to be switchable. With this configuration, the operator can turn off the drive of the steering motor 57 and perform a more delicate rotation operation of the steering handle 56.

In the present embodiment, the torque sensor 111 is attached to a position above the universal joint 107 on the upper shaft 83, and by configuring in this way, the input torque from the steering handle 56 can be easily detected. However, the position of the torque sensor 111 may be provided inside the upper shaft 83 with less change on the machine body side as a layout, or may be provided in the gear box 112 so as to suppress the deflection according to the motor reference. You may. When provided in the gear box 112, the space can be effectively used.

In the present embodiment, the power steering 108 is configured by a hydraulic electronically controlled power steering capable of electrically input operation from the controller 87, but is configured by a hydraulic power steering not based on electronic control. It may be configured as an EPS that does not depend on hydraulic pressure.

As shown in FIG. 6A or FIG. 6B, the internal gear 106 attached to the upper shaft 83 and the motor side gear 109 attached to the lower shaft 84 mesh with each other via the hub damper 110. There is. Therefore, the rotation is transmitted from the upper shaft 83 to the lower shaft 84 when the seedling transplanting machine 1 manually travels, and from the lower shaft 84 to the upper shaft 83 when the seedling transplanting machine 1 automatically travels.

In the present embodiment, the hub damper 110 is made of resin, and the internal gear 106 and the motor side gear 109 mesh with each other via the hub damper 110, so that the steering handle 56 and the pitman arm are mechanically connected. Even if there is, it is possible to suppress the vibration generated from the steering motor 57 from being transmitted to the steering handle 56.

Further, since the hub damper 110 is used, it is possible to prevent the steering mechanism 66 from being damaged even when the steering handle 56 is suddenly operated by the operator.

Further, in the present embodiment, the hub damper 110 is located below the universal joint 107, and the gear that meshes with the motor side gear 109 is configured as the internal gear 106, whereby the steering motor 57 is configured. The resistance between the motor side gear 109 and the internal gear 106 can be made relatively large during driving, and the vibration of the steering handle 56 is further suppressed.

On the other hand, the seedling transplanting machine 1 according to the present embodiment can plant seedlings in the field while automatically traveling in the field as follows, based on the control of the controller 87.

FIG. 7 is a schematic plan view showing a route through which the seedling transplanting machine 1 automatically travels in the field.

As shown in FIG. 7, the field 200 in which the seedling transplanting machine 1 according to the present embodiment automatically travels has a substantially rectangular shape in a plan view, and has two sides 201 and 203 extending in the north-south direction and 2 extending in the east-west direction. It is a paddy field having two sides 202 and 204, four peripheral regions 211 to 214 extending along each side 201 to 204, and a central region 210 surrounded by four peripheral regions 211 to 214. The four peripheral areas 211 to 214 are so-called headland.

In order to plant seedlings in the field while the seedling transplanting machine 1 automatically runs in the field 200, first, the automatic running changeover switch 78 is pressed and the controller 87 automatically runs with the automatic running turned on. The position information about the four corners of the field 200 and the position information of the reference line which becomes the reference when traveling straight is acquired.

Specifically, based on the maneuvering of the operator, the seedling transplanting machine 1 covers the peripheral regions 211 to 213 (three sides in the field 200) along the three sides 201 to 203 in the field 200 forming a substantially rectangular shape. While manually traveling in order, the automatic traveling lever 79 is swung downward at each of the four corners of the field 200, and the position information of the four corners of the field 200 is acquired. Here, manual running in order to acquire the position information of the four corners of the field 200 is called "teaching".

In the present embodiment, when the peripheral regions 211 to 213 are manually driven in order, the automatic traveling lever 79 is swung downward at the southwest corner of the field 200, and as soon as the position information is acquired, the automatic traveling lever 79 is swung downward. It is configured to display the position of the start point (first point) on the monitor 61. Similarly, in the northwest corner, the northeast corner, and the southeast corner, each time the automatic traveling lever 79 is swung downward, the monitor 61 is attached to the northwest corner (second point) and the northeast. The positions of the corner (third point) and the southeast corner (fourth point) are additionally displayed.

Therefore, since the operator can visually check the current teaching status on the monitor 61, if the position information (coordinates) cannot be obtained, the operator immediately redoes the swing operation of the automatic traveling lever 79. be able to.

Further, in the present embodiment, when the automatic traveling lever 79 is swung upward when manually traveling in the peripheral region 213 for teaching, the southwest corner and the northwest of the field 200 acquired before that are operated. It is configured to perform straight-ahead assist based on the position information of a total of two points in the corner of. That is, the steering motor 57 is automatically driven so as to be able to travel straight on the peripheral region 213 parallel to the straight line (reference line) connecting the southwest corner and the northwest corner of the field 200.

Next, the controller 87 calculates an automatic traveling route based on the position information of the four corners of the field 200 acquired by the GNSS receiver 130 when traveling on three sides in the field 200, and stores the data in the storage unit 93. do.

In the present embodiment, the data of the automatic traveling path includes straight running in the central region 210 (shown by the alternate long and short dash line in FIG. 7) and turning in the peripheral regions 212 and 214 (shown by the alternate long and short dash line in FIG. 7). Data of a route to be repeated (hereinafter referred to as "first route") and a route traveling through the peripheral regions 211 to 214 in order after traveling the first route (shown by a gray arrow in FIG. 7 below. , "Second route") and the first planting start position 205 (shown by a broken line in FIG. 7) to start planting seedlings when traveling straight from south to north on the first route. ) And the data of the second planting start position 206 (shown by the broken line in FIG. 7) where the planting of seedlings is started when traveling straight from north to south.

That is, the route that travels in the field 200 in a zigzag manner is called the "first route", the route that travels in the peripheral regions 211 to 214 in order is called the "second route", and the data of the automatic travel route includes , Data on the "first route" and data on the "second route" are included.

After the data of the automatic traveling route is stored in the storage unit 93, the seedling transplanting machine 1 manually travels to the position 207 where the seedling planting is started when traveling straight through the first row of the first route.

In this way, when the position 207 to start planting the seedlings is reached, the automatic traveling lever 79 is swung upward by the operator, and the seedling transplanting machine 1 automatically travels on the first route and to the central region 210. Start planting seedlings.

In the automatic traveling on the first route, the seedling transplanter 1 includes the detection signal output from the orientation sensor 80 and the steering sensor 58, and the current position information of the seedling transplanter 1 output from the GNSS receiver 130. , The HST servomotor 150 and the steering motor 57 are driven based on the automatic travel path, and as shown in FIG. 7, while traveling straight north in the "first row" located at the western end of the central region 210. When the seedlings are planted and reach the peripheral area 212, they turn and run straight south on the adjacent row (“second row”), and when they reach the peripheral area 214, they turn and turn. Seedlings are planted while traveling straight north on adjacent rows (“third row”), and similarly, the seedling transplanter 1 is located at the eastern end of the central region 210 in the “nth row”. The seedlings are planted in the central area 210 while automatically traveling until.

Finally, the seedling transplanting machine 1 plants seedlings in the peripheral regions 211 to 214 while automatically traveling on the second route in order, and ends the automatic traveling.

In this embodiment, the controller 87 properly steers while evaluating the actual traveling locus (automatic traveling locus) acquired by the GNSS receiver 130 while the seedling transplanting machine 1 turns by automatic traveling. It is configured to be.

Specifically, when the field 200 is in a state of large turn (understeer), the controller 87 drives the steering motor 57 with a slight oversteer (the steering angle of the steering handle 57 is large) and makes a small turn (understeer). In the case of oversteer), the steering motor 57 is driven with a slight understeer (the steering angle of the steering handle 57 is made smaller). With this configuration, proper turning can be performed. In addition, since the state of the field may differ from shore to shore, the appropriateness of steering drive may be configured to be corrected on the seedling splicing side and the opposite side, respectively. In this case, It is possible to prevent the headland from becoming rough. Further, the automatic traveling locus at the time of the previous turn (automatic traveling locus at the time of turning adjacent to the west side in FIG. 7) may be evaluated to optimize the steering, and the automatic traveling at the time of turning at the nearest place may be performed. The trajectory may be evaluated and the steering may be corrected.

The automatic running on the field 200 has been described above, but in the case of manual running with straight-ahead assist, seedlings are planted in the field 200 as follows.

First, the automatic traveling changeover switch 78 shown in FIG. 1 is pressed to turn off the automatic traveling, and then the position information of the start point of the reference line, which is the reference for traveling straight ahead, is acquired (step 1).

Specifically, the seedling transplanting machine 1 is moved to the northern end of the peripheral region 211 of the field 200 shown in FIG. 7, and the automatic traveling lever 79 is swung downward based on the maneuvering of the operator. As a result, the position information of the start point 218 of the reference line is acquired. At this time, the position information of the start point 218 is displayed on the monitor 61.

Then, based on the operator's maneuver, the seedling transplanter 1 is moved to the southern end of the peripheral region 211, as shown by the dashed line 208 with an arrow in FIG. 7, and the automatic traveling lever 79 swings downward. By being operated, the position information of the end point 219 of the reference line is acquired (step 2). At this time, the position information of the end point 219 is displayed on the monitor 61.

In this embodiment, for example, after the automatic driving is started, the manual driving with the straight-ahead assist is performed before the manual driving is performed, for example, when the automatic driving is switched to the manual driving by the operation of the automatic driving switching switch 78. When the automatic driving changeover switch 78 is turned on and the teaching to acquire the position information about the four corners of the field 200 and the position information of the reference line which is the reference when traveling straight is already performed, the automatic driving changeover switch 78 is performed. When is turned off, the first two points (two corners) from the position information of the four corners of the field acquired by teaching are configured to be used as the start point and end point of the reference line used for straight-ahead assist. There is.

In the present embodiment, at the time of teaching, first, before and after moving northward on the peripheral region 211, the position information of the southwestern and northwestern ends of the field 200 is acquired by the downward swinging operation of the automatic traveling lever 79. Therefore, when the vehicle is switched to manual driving, the position information of these two points is used as the position information of the start point and the end point of the reference line in the straight-ahead assist.

With this configuration, when the operator switches to manual driving during automatic driving, it is possible to save the trouble of acquiring the position information of the start point 218 and the end point 219 of the reference line of the straight-ahead assist. From, it is possible to smoothly shift to manual driving. In addition, during manual driving, seedlings can be planted in parallel with the seedling row planted during automatic driving.

The two points used as the start point and the end point of the reference line may not be the first two points in the acquired position information of the four corners, but may be two points on the immediately preceding straight path. In this case, the position information of the two points of the northeast and southeast corners acquired by the downward swing operation of the automatic traveling lever 79 before and after going south on the peripheral region 213 is used as the start point and the end point of the reference line. It will be used. Further, the two points used as the start point and the end point of the reference line may be configured to be selectable from the position information of each of the four corners acquired at the time of teaching for automatic driving.

Further, in the seedling transplanting machine 1 according to the present embodiment, when the automatic traveling changeover switch 78 is operated and the automatic traveling is switched to the manual traveling, the position information regarding the four corners of the field 200 and the reference for traveling straight ahead. While retaining the memory data related to the position information of the reference line, the manual driving is performed and the planted data is continuously updated. With this configuration, in places where it is clear that automatic driving is difficult, such as when driving near an underdrain, automatic driving is switched to manual driving, and then automatic driving is switched again. At that time, it is possible to smoothly return to automatic driving. Further, when the automatic running changeover switch 78 is operated to switch between automatic running and manual running, immediately before the position information regarding the four corners of the field 200 and the position information of the reference line as a reference when running straight. It may be configured to delete the previous data while retaining the memory data of. With this configuration, it is possible to continue the work even when the automatic traveling changeover switch 78 is erroneously operated, while avoiding the strain on the system due to the increase in memory data.

In this way, after the position information of the start point and the end point of the reference line is acquired, the seedling transplanting machine 1 is turned based on the maneuvering of the operator, and at the position of the planting start position 207 in the first row shown in FIG. The automatic traveling lever 79 is swung upward (step 3).

As a result, the straight-ahead assist is started, and the steering motor 57 is driven when the seedling transplanter 1 is planting the seedlings in the central region 210 while traveling straight to the north in the "first row" shown in FIG. The steering handle 56 is automatically steered so that the vehicle can travel straight in parallel to the line.

When the seedling transplanting machine 1 travels straight to the vicinity of the second planting start position 206, the operator swings the automatic traveling lever 79 upward (step 4). As a result, since the straight-ahead assist is stopped, the steering handle 56 is manually steered to the right by the operator, and the seedling transplanting machine 1 is turned to the "second row" position.

Hereinafter, in the same manner, the seedling transplanting machine 1 plantes seedlings in the central region 210 while repeating a straight running with a straight running assist in the central region 210 and a manual turning running in the peripheral region 214.

Finally, the seedling transplanting machine 1 plantes seedlings in the peripheral regions 211 to 214 while manually traveling on the second route in order, and ends the manual traveling.

When the automatic running changeover switch 78 shown in FIG. 2 is operated to switch from manual running with straight-ahead assist to automatic running, the seedling transplanting machine 1 is located in or near the same field 200. If so, the position information of the reference line acquired in step 1 is stored (stored) in the storage unit 93. Therefore, when the manual driving is switched to again, the manual driving can be smoothly performed.

On the other hand, FIG. 8 is an explanatory diagram showing a flow from when the seedling transplanting machine 1 automatically starts turning to when the front wheels slip.

When the seedling transplanter 1 turns at the end of the field 200 by automatic running, the differential mechanism 15 usually increases the rotation of the outer front wheel 8 once, as shown in the process (i) in FIG. However, gradually, the resistance of the front wheel 8 on the outer side of the turn increases, and the differential mechanism 15 shown in FIG. 3 reduces the number of rotations of the front wheel 8 on the outer side of the turn, which is not idling, as shown by the process (ii). , The driving force may be transmitted to the front wheel 8 on the inner side of the turn by being biased. In this case, the side clutch of the rear wheel 9 on the inner side of the turn may be disengaged, and as shown in the process (iii), the torque (traction force) for pulling the seedling transplanting machine 1 is insufficient, and the traveling wheel. 8 and 9 slip and the seedling transplanting machine 1 cannot run.

On the other hand, even when the vehicle automatically travels in the central part of the field, for example, when an underdrain or the like is in the central part of the field, when the steering handle 56 is turned immediately before that, the traveling wheels 8, 9 may slip and the seedling transplanting machine 1 may not be able to run.

In light of such a situation, in the seedling transplanting machine 1 according to the present embodiment, even when the traveling wheels 8 and 9 slip on the first route by automatic traveling, even if the traveling wheels 8 and 9 slip. By automatically detecting the idling indicated as the process (iii) and diff-locking the pair of left and right front wheels 8 in the following manner, it is possible to continue running automatically and stably.

FIG. 9 is a flowchart showing a control flow until the controller 87 detects the idling of the traveling wheels 8 and 9 while the seedling transplanting machine 1 shown in FIG. 1 automatically travels, and further eliminates the idling.

As shown in FIG. 9, first, the controller 87 determines whether or not the traveling wheels 8 and 9 are idling (step s1).

In the present embodiment, the controller 87 sets the rotation speed of the left front wheel axle 17 within the calculated predetermined time (per predetermined time, per unit time) based on the detection signal of the front wheel rotation sensor 21 to L, and sets the predetermined time. If the absolute value of the difference between L and R is less than the predetermined value when the number of revolutions of the front wheel axle 18 on the right side (per predetermined time, per unit time) is R, the traveling wheel 8, It is determined that 9 is not idling, and if it is equal to or more than a predetermined value, it is determined that the traveling wheels 8 and 9 are idling.

In this way, by determining that the traveling wheels 8 and 9 are idling when the difference between the rotation speeds L and R of the left and right front wheel axles 17 and 18 is opened to a predetermined value or more, idling detection at low speed traveling is detected. It is possible to reduce the sensitivity of the wheel and suppress false detection of idling. In this embodiment, the predetermined value is set to 500.

By detecting the rotation speeds of the left and right front wheel axles 17 and 18 using the front wheel rotation sensor 21, it is possible to directly detect the idling of the front wheels 8 of the front and rear traveling wheels 8 and 9. However, when the front wheels 8 are idling, it is presumed that the traction force is insufficient and the rear wheels 9 are also idling.

As a result of determining whether or not the traveling wheels 8 and 9 are idling, if the traveling wheels 8 and 9 are not idling, the controller 87 determines that the traveling wheels 8 and 9 are idling. Acquisition and determination of the detection signal of the front wheel rotation sensor 21 are repeated.

On the other hand, as a result of the determination, when the traveling wheels 8 and 9 are idling, the controller 87 drives the diff lock motor 16 (see FIG. 3) and limits the differential rotation of the left and right front wheel axles 17 and 18. (Step s2).

As a result of limiting the differential rotation of the left and right front wheel axles 17 and 18, the driving force is also applied to the front wheel 8 of the pair of left and right front wheels 8 to which the driving force for traveling is hardly transmitted. Since it is sufficiently transmitted, the seedling transplanting machine 1 can automatically return to running.

In this way, when the differential rotation of the left and right front wheel axles 17 and 18 is restricted (the differential lock is operated), the controller 87 determines whether or not the idling of the traveling wheels 8 and 9 is eliminated (step s3).

Specifically, the controller 87 starts after the differential rotation of the left and right front wheel axles 17 and 18 is restricted, and the front wheel axles 17 and 18 are rotated by a predetermined rotation based on the detection signal of the front wheel rotation sensor 21. Determine if it is. As a result, when the front wheel axles 17 and 18 are rotated by a predetermined rotation, it is considered that the idling of the traveling wheels 8 and 9 has already been eliminated, and when the front wheel axles 17 and 18 are not rotated by a predetermined rotation at the time of determination. , It is configured to consider that the idling of the traveling wheels 8 and 9 has not been eliminated.

As a result of the determination, when the front wheel axles 17 and 18 are rotated by a predetermined rotation and the idling of the traveling wheels 8 and 9 is eliminated, the controller 87 drives the differential lock motor 16 (see FIG. 3) to drive the left and right wheels. The differential rotation of the front wheel axles 17 and 18 is allowed (step s4). In this embodiment, the controller 87 considers that the idling of the traveling wheels 8 and 9 has been eliminated when 50 pulses are counted at the sensor position of the front wheel rotation sensor 21, and the left and right front wheel axles 17 Although it is configured to allow the differential rotation of 18, it may be configured to correct the rotation amount depending on the recent turning condition (diff sensor value at the time of normal turning). With such a configuration, it is possible to eliminate unnecessary diff locks and facilitate the return to the automatic traveling route.

On the other hand, if the front wheel axles 17 and 18 have not been rotated by a predetermined rotation and the idling of the traveling wheels 8 and 9 has not been eliminated, the controller 87 determines until the front wheel axles 17 and 18 are rotated by a predetermined rotation. Is repeated.

As described above, the seedling transplanting machine 1 according to the present embodiment automatically returns to running by limiting the differential rotation of the front wheel axles 17 and 18 even when the traveling wheels 8 and 9 slip. can do.

On the other hand, FIG. 10 is an explanatory diagram showing an increase / decrease in the number of rotations of the left and right front wheels 8 when the seedling transplanting machine 1 shown in FIG. 1 turns in a field having different hardness, and is shown in FIG. 10 (a). 1 is an explanatory diagram showing an increase / decrease in the number of rotations of the left and right front wheels 8 when the seedling transplanting machine 1 turns in a hard field A, and FIG. 10B is an explanatory diagram in a field B where the seedling transplanting machine 1 is soft. It is explanatory drawing which shows the increase / decrease of the number of rotations of the left and right front wheels 8 at the time of turning travel.

In the present embodiment, the controller 87 is configured to detect the state of each field (particularly the depth and hardness of the field) when the seedling transplanting machine 1 turns and travel, and reflect it in various controls. First, a detailed explanation will be given below on how to detect the condition of each field.

When the seedling transplanting machine 1 travels straight, the traveling power (torque) distributed substantially equally to the left and right front wheel axles 17 and 18 is usually generated by the differential mechanism 15 when traveling in a field. , It is distributed to the front wheel axle 17 or 18 located on the outer side in a biased manner.

Here, in the case of turning in a soft (deep) field, the load applied to the front wheel 8 (outer ring) located on the outside is larger than in the case of turning in a hard (shallow) field. As a result, as shown in FIGS. 10 (a) and 10 (b), the rotation speeds of the left and right front wheel axles 17 and 18 are higher in the case of turning in the soft field B than in the hard field A. The amount of increase / decrease increases.

Therefore, the rotation speeds of the left and right front wheel axles 17 and 18 to which the driving force is transmitted by the differential mechanism 15 when the seedling transplanting machine 1 is turning are detected and compared by using the front wheel rotation sensor 21. Thereby, the controller 87 can detect the hardness (depth) of the traveling field without separately providing a hardness sensor, a rake sensor, a ring sensor, or the like for detecting the hardness of the field.

Further, the controller 87 is configured to reflect the hardness (depth) of the field detected in this way in various controls as follows.

First, the controller 87 is configured to automatically change the angle of attack of the center float 38, i.e., the sensitivity of the float sensor 33, according to the detected field hardness.

Secondly, the controller 87 is configured to change the heights of the central leveling rotor 31 and the left and right leveling rotors 32 according to the detected hardness of the field.

Specifically, when the field is soft and the resistance is high, the controller 87 adjusts the position of the rotor low, and conversely, when the field is hard and the resistance is low, the controller 87 adjusts the position of the rotor high. It is configured in.

Thirdly, the controller 87 increases the amount of fertilization applied to the field by the fertilization device 26 when the detected field hardness is hard, and the fertilization device 26 when the detected field hardness is soft. It is configured to reduce the amount of fertilization applied to the field. With such a configuration, variable fertilization can be performed inexpensively without separately providing an expensive hardness detecting means such as an ultrasonic sensor.

Fourth, the controller 87 automatically adjusts the seedling planting depth deeply when the detected field hardness is hard, and seedling planting when the detected field hardness is soft. It is configured to automatically adjust the depth to shallow.

As described above, the controller 87 of the seedling transplanting machine 1 according to the present embodiment detects the depth (hardness) of each field detected when the seedling transplanting machine 1 turns and travels, and reflects it in various controls. However, it may be configured to correct the steering time (pulse) and the drive rotation (pulse) in the turning assist according to the detected hardness of the field. With this configuration, it is possible to perform turning as set in any field.

On the other hand, FIG. 11 is a flowchart relating to the control of increasing the engine speed when the automatic running start operation is performed in the seedling transplanting machine 1 shown in FIG.

With the automatic travel path data stored in the storage unit 93 and with the automatic travel changeover switch 78 turned on, the automatic travel lever 79 is swung upward (that is, the seedling transplanter 1). (The operation to start automatic driving is performed), as shown in FIG. 11, first, the controller 87 determines that the rotation speed of the engine 7 per predetermined time is less than a predetermined value based on the detection signal of the engine rotation sensor 96. It is determined whether or not there is (step S1). Note that step S1 is performed regardless of whether or not the seedling transplanting machine 1 is running.

As a result of the determination, when the rotation speed of the engine 7 per predetermined time is equal to or higher than the first predetermined value, the controller 87 determines that the steering motor 57 causes the seedling transplanting machine 1 to travel along the automatic traveling path. The drive is started, and the steering of the steering wheel is started (step S2). At this time, when the seedling transplanting machine 1 is stopped, the controller 87 drives the HST servomotor 150 at the same time as driving the steering motor 57 to start the running of the seedling transplanting machine 1.

In this embodiment, the controller 87 is configured to drive the steering motor 57 at a speed proportional to the output of the hydrostatic stepless transmission 25, and the output of the hydrostatic stepless transmission 25. When the seedling transplanter 1 is traveling at high speed, the steering motor 57 is driven quickly to rotate the steering handle 56 quickly, the output of the hydrostatic stepless transmission 25 is low, and the seedling transplanter When 1 is traveling at a low speed, the driving speed of the steering motor 57 is slowed down and the steering handle 56 is rotated at a low speed. With such a configuration, the seedling transplanting machine 1 can smoothly change the direction such as turning, and it is not necessary to correct the automatic traveling route.

On the other hand, as a result of the determination, when the rotation speed of the engine 7 per predetermined time is less than the first predetermined value, the controller 87 uses the throttle motor 97 until the rotation speed of the engine 7 becomes equal to or more than the first predetermined value. (Step S3).

In this way, when the rotation speed of the engine 7 is increased to the first predetermined value or more, the controller 87 controls the steering motor so that the seedling transplanting machine 1 travels along the automatic traveling path as shown in FIG. 57 is driven and the steering handle 56 is steered (step S2).

As a result, based on the detection signal of the torque sensor 111, the input torque is converted into a larger torque by the power steering 108, and the direction of the front wheel 8 is changed. In addition, at this time, when the seedling transplanting machine 1 is stopped, the controller 87 drives the HST servomotor 150 to start the running of the seedling transplanting machine 1.

As described above, after the automatic running start operation is performed, the rotation speed of the engine 7 is secured before the steering handle 56 as the steering device is steered, which causes the insufficient hydraulic pressure in the power steering 108. It is possible to prevent the behavior of the steering mechanism 66 from becoming unstable, and to enable smooth automatic steering (including turning of the seedling transplanting machine 1) and automatic running by the controller 87 and the steering mechanism 66. Further, this makes it possible to rotate the hydraulic pump and secure the hydraulic pressure of the power steering 108, especially when the wet field is turning and while traveling at a relatively low speed.

In the present embodiment, in the automatic traveling, as described above, after the engine 7 rotation speed is secured, the controller 87 steers the steering handle 56, and when the vehicle is stopped, the HST servomotor 150 is further operated. Is configured to start the running of the seedling transplanting machine 1, but if the rotation speed of the engine 7 is secured prior to the steering of the steering handle 56, the steering of the steering handle 56 and the HST servo Both timings of departure by driving the motor 150 may be configured first, and steering of the steering steering wheel 56 and departure timing may be simultaneous.

In the present embodiment, the controller 87 is configured to correct the output of the HST servomotor 150 in consideration of the increase in the vehicle speed of the seedling transplanting machine 1 due to the increase in the rotation speed of the engine 7. The change in vehicle speed due to the increase in the number of revolutions of the engine is suppressed.

Further, as in the case where the output of the hydrostatic continuously variable transmission 25 is increased or the output is increased before the steering handle 56 as the steering device is steered after the automatic traveling start operation is performed. , There is no need to correct the automatic driving route.

In this embodiment, the first predetermined value is determined so that sufficient hydraulic pressure is supplied from the hydraulic pump to the power steering 108, but a means for detecting the rotation speed of the hydraulic pump is separately provided. When the rotation speed of the hydraulic pump is less than the specified value of the rotation speed at which sufficient hydraulic pressure can be supplied to the power steering 108, the controller 87 drives the throttle motor 97 to reduce the rotation speed of the engine 7 to the specified value. Alternatively, it may be configured to increase above the specified value.

As described above, the controller 87 of the seedling transplanting machine 1 configured to secure the rotation speed of the engine 7 and enable stable automatic steering to start requires hydraulic pressure during automatic traveling as follows. At the timing, the proper determination of the rotation speed of the engine 7 is performed, and as a result, when the rotation speed of the engine 7 is less than the required value, the throttle motor 97 is driven to drive the rotation speed of the engine 7 (and by extension, the rotation speed of the engine 7). It is configured to increase the rotation speed of the hydraulic pump).

First, when the turning operation of the seedling transplanting machine 1 is scheduled on the automatic traveling path, the controller 87 increases the rotation speed of the engine 7 before the seedling transplanting machine 1 turns. It is configured. With this configuration, the behavior of the airframe can be smoothed.

Second, if there is a plan to turn immediately after raising and lowering the seedling planting section 63 on the automatic traveling path, the controller 87 will perform the rotation speed of the engine 7 before raising and lowering the seedling planting section 63. Is configured to increase to the numerical value (rotational speed) required for the turning operation. With this configuration, the behavior of the aircraft can be smoothed from the end of planting in a certain row on the field to the turning and the beginning of planting in an adjacent row.

The rotation speed of the engine 7 is increased at the above timing, and after the seedling transplanting machine 1 turns, the controller 87 returns the rotation speed of the engine 7 to the value corresponding to the operation position of the forward / backward lever 35. It is configured.

Here, in the present embodiment, when the rotation speed of the engine 7 is returned, the rate of change is kept low (the rotation speed of the engine 7 is slowly lowered) to prevent the vehicle speed from suddenly changing and accelerating. It is configured. With such a configuration, the behavior of the airframe can be smoothed, and it is possible to suppress the occurrence of pitching of the airframe when the planting of seedlings is started after turning.

On the other hand, when the seedling transplanting machine 1 manually travels based on the maneuvering of the operator, the controller 87 appropriately determines the rotation speed of the engine 7 at the following timings when hydraulic pressure is required, and as a result, the result is When the rotation speed of the engine 7 is less than the required value, the throttle motor 97 is driven to increase the rotation speed of the engine 7 (and thus the rotation speed of the hydraulic pump).

First, when turning is detected based on the detection signal of the steering sensor 58, the controller 87 determines whether or not the accelerator rotation is equal to or higher than the specified value, and when the accelerator rotation is less than the specified value. Is configured to increase the rotation speed of the engine 7, whereby the seedling transplanting machine 1 can smoothly turn.

Secondly, when the rise of the seedling planting portion 63 is detected based on the detection signal of the link sensor 90, the controller 87 determines whether or not the accelerator rotation is equal to or higher than the specified value, and the accelerator rotation is specified. If it is less than the value, it is configured to increase the rotation speed of the engine 7, whereby the hydraulic lift is increased and smooth operation can be performed. When the rise of the seedling planting portion 63 is detected, the controller 87 may be configured to raise the engine speed to the speed required for turning. When the seedling planting portion 63 is raised, the seedling transplanting machine 1 often turns immediately after that. Therefore, by configuring in this way, it is possible to prevent a shortage of oil pressure immediately after the turning is started. can do.

By increasing the rotation speed of the engine 7 at the above timing, the seedling transplanting machine 1 can prevent insufficient oil pressure even in manual running, and can realize smooth behavior of the machine. ..

On the other hand, FIG. 12 is a drawing relating to the control of the steering motor 57 shown in FIG. 6A.

Here, in the conventional seedling transplanting machine, there is a problem that the vibration generated by the transient response is transmitted from the steering motor that drives the steering handle to the steering handle, and the steering handle rattles.

In light of such a situation, in the present embodiment, the steering handle 56 is steered while the seedling transplanting machine 1 is automatically traveling. Therefore, when driving the steering motor 57, the controller 87 uses the automatic traveling path. Instead of outputting the control signal corresponding to the control target value of the motor rotation angle calculated from the orientation sensor 80 to the steering motor 57 from the beginning, the control target value of the motor rotation angle is intentionally set. A control signal corresponding to a provisional target value (control amount) corresponding to the values before and after is output to the steering motor 57. In this embodiment, PI control is used as a method for calculating the control amount.

For example, when the control target value shown in FIG. 12 is 100, the controller 87 dares to set 105, which is one of the front and rear (upper and lower) values, as the first provisional target value, and the first provisional target value. A control signal corresponding to the target value is output to the steering motor 57.

Next, the controller 87 is the other before and after the control target value (upper and lower other), and the difference from the control target value 100 is smaller than the control amount 105 (first provisional target value) output last time. 97 is set as the second provisional target value, and the control signal corresponding to the second provisional target value is output to the steering motor 57.

Further, the controller 87 is one before and after the control target value (one above and below), and the difference from the control target value 100 is smaller than the control amount 97 (second provisional target value) output last time. 102 is set as the third provisional target value, and the control signal corresponding to the third provisional target value is output to the steering motor 57.

Next, the controller 87 is the other before and after the control target value (upper and lower other), and the difference from the control target value 100 is smaller than the control amount 102 (third provisional target value) output last time. 99 is set as the fourth provisional target value, and the control signal corresponding to the fourth provisional target value is output to the steering motor 57.

In this way, the controller 87 does not output the control signal corresponding to the control target value of the motor rotation angle from the beginning, but intentionally outputs the value before and after (up and down) the control target value as a tentative target value, and the target. Since it is configured to gradually converge to the target value from before and after (up and down) the controlled amount, the transient response of the steering motor 57 and the vibration generated by the transient response can be suppressed.

In the present embodiment, the steering motor 57 is configured by a stepping motor, and the control target value of the steering motor 57 is calculated based on PI control. However, the steering motor 57 is configured by the stepping motor. This is not always necessary, and the control target value may be configured to be calculated based on PID control or PD control.

Further, the PI control may increase the ratio (gain) of the I control for eliminating the residual deviation when approaching the provisional target value and the control target value, and the integral control time for eliminating the residual deviation may be long. As a result, the rate of change of the control amount of the steering motor 57 can be lowered, and the vibration generated from the steering motor 57 can be further suppressed.

When the integral control time for eliminating the residual deviation is configured to be long, the target value of the control amount is changed from the first tentative target value to the second tentative target, especially when counting from the timing of the start of driving of the steering motor 57. The target value of the control amount changes from the first provisional target value to the second provisional target value rather than the control speed up to T1 (see FIG. 12) when the value is switched to (the timing when the second provisional target value is determined). The time required from the switching timing T1 to the timing at which the target value of the control amount is switched to the original control target value (100 in the above example) (the timing at which the original control target value is set as the target value) is configured to be long. Thereby, the vibration generated from the steering motor 57 can be effectively suppressed.

According to this embodiment, if the traveling wheels 8 and 9 are idling while the seedling transplanting machine 1 is traveling, the differential rotation of the left and right front wheel axles 8 and 9 is restricted. Since it is configured, it prevents the situation where the driving force (torque) is continuously transmitted to the front wheels 8 that are idling among the left and right front wheels 8, and the driving force is sufficiently transmitted to the traveling wheels that are not idling. Therefore, the seedling transplanting machine 1 can be stably run by the automatic running.

Further, according to the present embodiment, when the automatic running of the seedling transplanting machine 1 is started, if the rotation speed of the engine 7 is less than the first predetermined value, the rotation speed of the engine 7 is increased. Since the steering of the steering handle is started later, the force for steering the pair of left and right front wheels 8 as the steering wheels does not fall below the resistance force of the road surface due to the lack of hydraulic pressure in the power steering 108, and is stable. , The steering mechanism 66 and the controller 87 can start automatic steering.

Further, according to the present embodiment, since the driving speed (steering speed) of the steering handle 56 by the steering motor 57 is configured to be proportional to the output of the hydrostatic continuously variable transmission 25, the seedling transplanting machine 1 It is possible to smoothly change the direction of travel such as turning, and therefore it is not necessary to make corrections to the automatic traveling path.

In addition, according to the present embodiment, when the controller 87 drives the steering motor 57, the controller 87 does not drive the steering motor 57 with the control target value as the control amount from the beginning, but sets a value around the control target value. Since it is set as a tentative target value and the control amount of the steering motor 57 is configured to gradually converge to the control target value, the vibration generated by the transient response of the steering motor 57 and the vibration transmitted to the steering handle 56. Can be suppressed.

Further, according to the present embodiment, the internal gear 106 provided on the upper shaft 83 and the motor side gear 109 driven by the steering motor 57 mesh with each other via the hub damper 110, so that the steering motor 57 to the steering handle 56 It is possible to suppress the transmission of vibration to the gear.

FIG. 13 is a flowchart showing a flow of control regarding detection and elimination of slipping of the traveling wheels 8 and 9 by the controller 87 after the seedling transplanting machine 1 according to another preferred embodiment of the present invention is energized.

In this embodiment, when the key is inserted into the key cylinder (not shown) for starting the engine 7 (see FIG. 1) and the seedling transplanting machine 1 is energized, the controller 87 is as shown in FIG. First determines whether or not there is an output of the hydrostatic continuously variable transmission (HST) 25 (step ss1).

Specifically, the controller 87 determines the presence / absence of the output of the hydrostatic continuously variable transmission 25 based on the detection signal of the potentiometer 122 (see FIG. 4B) that detects the rotation angle of the trunnion arm 121. .. The output of the hydrostatic continuously variable transmission 25 may be determined based on the detection signal of the forward / backward lever sensor 36 that detects the position of the forward / backward lever 35, or based on the detection signal of the rear wheel rotation sensor 29. You may go.

As a result of the determination, if there is no output, the presence / absence of the output of the hydrostatic continuously variable transmission 25 is determined based on the detection signal of the potentiometer 122 until the output of the hydrostatic continuously variable transmission (HST) 25 is output. Repeated.

On the other hand, as a result of the determination, when there is an output of the hydrostatic continuously variable transmission 25, the controller 87 changes the position information (position coordinates) of the seedling transplanter 1 acquired by the GNSS receiver 130. It is determined whether or not it is (step ss2).

As a result, when the position information of the seedling transplanting machine 1 has not changed, the controller 87 determines whether or not the traveling wheels 8 and 9 are idling based on the ratio of the rotation speeds of the pair of left and right front wheels 8. (Step ss3).

Specifically, the number of revolutions of the left front wheel axle 17 within a predetermined time calculated based on the detection signal of the front wheel rotation sensor 21 is L, and the number of revolutions of the left front wheel axle 17 within the predetermined time (per unit time) is set to L. When the rotation speeds of the right front wheel axles 17 and 18 (per predetermined time) are R, the value of L / R (ratio of the rotation speeds of the left and right front wheels 8 per predetermined time) is 1/50 <L /. When R <50, the controller 87 determines that the traveling wheels 8 and 9 are not idling, and otherwise determines that the traveling wheels 8 and 9 are idling. In other words, when the ratio of the larger rotation speed to the smaller rotation speed of the left and right front wheel axles 17 and 18 is 50 or more, the controller 87 idles the traveling wheels 8 and 9. If the ratio is less than 50, the controller 87 determines that the traveling wheels 8 and 9 are not idling.

Here, the ratio of the rotational speeds of the left and right front wheel axles 17 and 18 by the differential mechanism 15 is usually less than 10 times at the maximum. On the other hand, when the differential mechanism 15 biases the driving force to one of the left and right front wheels 8 that is idling, and the driving force is hardly transmitted to the other front wheels 8 of the left and right that are not idling, the left and right The ratio of the rotational speeds of the front wheel axles 17 and 18 is 100 times or more. In light of such a situation, in the present embodiment, when the ratio of the rotation speeds of the left and right front wheel axles 17 and 18 exceeds 50 times, it is determined that the traveling wheels 8 and 9 are idling. It is configured as follows. By limiting the number of revolutions of the left and right front wheel axles 17 and 18 by the minimum number of revolutions, the sensitivity of slip detection of the traveling wheels 8 and 9 during low-speed running is lowered, for example, when the vehicle turns continuously. It is possible to prevent the malfunction of the diff lock due to the false detection of slipping.

As a result of determining whether or not the traveling wheels 8 and 9 are idling, if the traveling wheels 8 and 9 are not idling, the process returns to the determination of the output of the hydrostatic continuously variable transmission (HST) 25 (step). See ss1).

On the other hand, as a result of the determination, when the traveling wheels 8 and 9 are idling, the controller 87 drives the diff lock motor 16 (see FIG. 3) and limits the differential rotation of the left and right front wheel axles 17 and 18. (Step ss4).

As a result of limiting the differential rotation of the left and right front wheel axles 17 and 18, the driving force is also applied to the front wheel 8 of the pair of left and right front wheels 8 to which the driving force for traveling is hardly transmitted. Since the seedling transplanting machine 1 is sufficiently transmitted, the seedling transplanting machine 1 can automatically return to running (straight running or turning running). When the differential rotation of the left and right front wheel axles 17 and 18 is restricted, the position information at that point may be stored in the storage unit 93 or the online storage. With such a configuration, the stored position information can be effectively used at the time of the next work or the next passage. Further, in the case of online storage, it can be used on other aircraft, statistical processing and management can be easily performed, and it is not necessary to provide an online interface.

In this way, when the differential rotation of the left and right front wheel axles 17 and 18 is restricted (the differential lock is operated), the controller 87 determines whether or not the idling of the traveling wheels 8 and 9 is eliminated (step ss5).

In the present embodiment, the controller 87 eliminates the idling of the traveling wheels 8 and 9 when the seedling transplanting machine 1 moves a predetermined distance (for example, 1 m) within the time counting from the start of the operation of the diff lock. If the seedling transplanting machine 1 has not moved a predetermined distance within the time, it is determined that the idling of the traveling wheels 8 and 9 has not been eliminated. When the traveling wheels 8 and 9 slip and the left and right front wheels 8 are differentially locked when the seedling transplanting machine 1 makes a turning run, the determination of the slipping cancellation of the traveling wheels 8 and 9 is made on the inner side of the turning. It may be performed depending on whether or not the rotation pulse (rotation speed) of the rear wheel 9 with which the clutch is disengaged per predetermined time is equal to or more than a predetermined value. That is, when the traveling wheels 8 and 9 slip and the seedling transplanting machine 1 cannot travel, the driving force is not transmitted to the rear wheels 9 on the inside of the turning, and the rear wheels 9 are almost non-rotating. It can be determined that the idling of the traveling wheels 8 and 9 is not eliminated only when the rotation pulse of the rear wheels 9 (and the rotation pulse of the rear wheel axle 82 is less than a predetermined value). Since it is not necessary to use the position information in the slip elimination determination method, it may be configured to be applied only to the situation where it is difficult to acquire the position information by the GNSS receiver.

As a result of the determination, when the idling of the traveling wheels 8 and 9 is eliminated, the controller 87 drives the diff lock motor 16 (see FIG. 3) and allows the differential rotation of the left and right front wheel axles 17 and 18. (Step ss6).

On the other hand, if the idling of the traveling wheels 8 and 9 is not resolved as a result of the determination, the controller 87 determines whether or not the seedling transplanting machine 1 is turning (step ss7).

Specifically, the controller 87 acquires the detection value of the steering angle of the steering handle 56 from the steering sensor 58, and when the steering angle of the current steering handle 56 exceeds a predetermined angle (for example, 225 degrees). Determines that the seedling transplanter 1 is swiveling, and if not, determines that the seedling transplanter 1 is not swiveling. In addition, in order to determine whether or not the vehicle is turning, the torque sensor 111 may be configured to check the input torque.

As a result of the determination, when the seedling transplanting machine 1 is turning, as described in the above embodiment, the side clutch of the rear wheel 9 inside the turning is normally in the disengaged state, and the traction force of the rear wheel 9 is used. Therefore, the controller 87 drives the solenoid valve 103 to switch the side clutch of the rear wheel 9 on the inside of the turn to the engaged state (step ss8). In this embodiment, the side clutch of the rear wheel 9 on the inner side of the turn is intermittently engaged (intermittently turned on), and the seedling transplanting machine 1 is configured in this way. Can smoothly turn while utilizing the traction force of the rear wheel 9 on the inside of the turn (hereinafter, when the seedling transplanting machine 1 turns, the side clutch of the rear wheel 9 located inside is intermittently engaged. Disengagement is called "pumping clutch"). While the pumping clutch is engaged, the side clutches of the left and right rear wheels 9 are both engaged (engaged). In step ss8, the side clutch of the rear wheel 9 may be configured to be continuously engaged instead of the pumping clutch to further increase the traction force, and in the pumping clutch, as a pumping turn. , The on / off timing and length of the side clutch may be automatically optimized.

In this way, after the pumping clutch is started, the seedling transplanting machine 1 determines whether or not the idling of the traveling wheels 8 and 9 is eliminated (step ss9).

In the present embodiment, the controller 87 eliminates the idling of the traveling wheels 8 and 9 when the seedling transplanting machine 1 moves a predetermined distance (for example, 1 m) in time, counting from the start of the pumping clutch. If the seedling transplanting machine 1 has not moved a predetermined distance within the time, it is determined that the idling of the traveling wheels 8 and 9 has not been eliminated. It should be noted that the determination of the idling cancellation of the traveling wheels 8 and 9 is made at the timing when the side clutch of the rear wheel 9 on the inside of the turn is disengaged in the pumping clutch, and the rotation pulse (rotation) of the rear wheel 9 on the inside of the turn per predetermined time. The number) may be determined depending on whether or not the value is equal to or higher than a predetermined value. In this case, the rotation pulse (rotation speed) per predetermined time of the rear wheel 9 on the inside of the turning where the side clutch is disengaged is predetermined. Only when it is less than the value, it is determined that the idling of the traveling wheels 8 and 9 is not resolved. According to this slip elimination determination method, even when the acquisition of the GNSS radio wave fails, the effect of the diff lock of the front wheel 8 and the pumping clutch of the rear wheel 9 can be determined (determination of slip elimination).

As a result of the determination, when the idling of the traveling wheels 8 and 9 is eliminated, the controller 87 drives the diff lock motor 16 (see FIG. 3) and allows the differential rotation of the left and right front wheel axles 17 and 18. ..

On the other hand, if the idling of the traveling wheels 8 and 9 is not eliminated as a result of the determination, the controller 87 stops the output of the hydrostatic continuously variable transmission 25 and drives the steering motor 57. The steering handle 56 is steered to a straight-ahead position, and the seedling planting portion 63 is lowered to a working position (step ss10).

In this way, by steering the steering handle 56 to the straight-ahead position (turning the steering handle 56 so that the seedling transplanting machine 1 which is an example of the work vehicle goes straight), the idling state of the traveling wheels 8 and 9 is eliminated. It can be made easier. Further, by lowering the seedling planting portion 63 to the working position, a part of the power of the engine 7 is directed to the driving power without being divided into the driving power (hydraulic lift of the seedling planting portion 63). , The traction force can be increased. In addition, in the wet field, there is an effect that the buoyancy can be utilized by lowering the seedling planting portion 63.

Next, in the controller 87, if the seedling transplanting machine 1 travels a predetermined distance (1 m in the present embodiment), the position of the seedling transplanting machine 1 is set to the working area (in the present embodiment, the working vehicle is). Since it is configured as a seedling transplanting machine 1 for planting seedlings, it is determined whether or not the seedling planting unit 63 deviates from the central region 210 and the peripheral regions 211 to 214) where the seedlings are planted (step ss11).

As a result of the determination, when the position of the seedling transplanter 1 deviates from the work area, the controller 87 ends the control with the output of the hydrostatic continuously variable transmission 25 (HST) stopped.

On the other hand, if the position of the seedling transplanter 1 does not deviate from the work area as a result of the determination, the controller 87 causes the hydrostatic continuously variable transmission 25 to output a fixed amount and performs four-wheel torque running ( Step ss12). The fixed amount of the hydrostatic continuously variable transmission 25 is configured to be 200 pulses of the front wheel rotation sensor 21 (predetermined rotation of the front wheel 8) in this embodiment.

In this way, after the hydrostatic continuously variable transmission 25 outputs a fixed amount, the controller 87 starts the output, and based on the detection signal of the front wheel rotation sensor 21, the front wheel axles 17 and 18 rotate by a predetermined amount. It is determined whether or not it has been rotated (step ss13).

As a result, when the front wheel axles 17 and 18 are rotated by a predetermined rotation, it is estimated that the idling of the traveling wheels 8 and 9 has already been eliminated, so that the controller 87 drives the diff lock motor 16. Allows differential rotation of the left and right front wheel axles 17 and 18. In the present embodiment, the predetermined rotation amount is until 200 pulses are counted at the sensor position of the front wheel rotation sensor 21.

On the other hand, when the front wheel axles 17 and 18 have not been rotated by a predetermined rotation, the determination by the controller 87 is repeated until the front wheel axles 17 and 18 are rotated by a predetermined rotation.

On the other hand, as a result of determining whether or not the seedling transplanting machine 1 is swiveling in step ss7, if the seedling transplanting machine 1 is not swiveling, the process proceeds to step ss10 as shown in FIG. In this case, the work area in step ss11 may be configured to include only the central area 210.

According to this embodiment, if the traveling wheels 8 and 9 are idling while the seedling transplanting machine 1 is traveling, the differential rotation of the left and right front wheel axles 8 and 9 is restricted. Since it is configured, it prevents the situation where the driving force (torque) is continuously transmitted to the idling front wheels 8 among the left and right front wheels 8, and the driving force is sufficiently transmitted to the traveling wheels that are not idling. Therefore, the work vehicle can be stably traveled by the automatic traveling.

Further, according to the present embodiment, the controller 87 confirms that the position of the seedling transplanter 1 acquired by the GNSS receiver 130 does not change despite the output of the hydrostatic continuously variable transmission 25. Since it is configured to determine whether or not the traveling wheels 8 and 9 are idling, it is possible to effectively prevent the malfunction of the differential locks of the pair of left and right front wheels 8.

Further, according to the present embodiment, even with a simple configuration, it is possible to electrically detect the idling of the traveling wheels 8 and 9 at all times when the seedling transplanting machine 1 is energized. The front wheel axles 17 and 18 can be diff-locked even in a place, and running stability and work continuity can be improved.

Further, according to the present embodiment, even when the GNSS receiver 130 functioning as the position information acquisition means does not function due to radio wave conditions or the like, the rotation speeds of the left and right front wheel axles 17 and 18 are detected and the ratio is determined. By calculating, it is possible to detect the idling of the traveling wheels 8 and 9 (the idling of the front wheels 8 is directly detected, but the idling of the rear wheels 9 is naturally estimated due to insufficient traction force). ..

Further, according to the present embodiment, the idling of the traveling wheels 8 and 9 can be detected only by detecting the rotation speeds of the left and right front wheel axles 17 and 18 and calculating the ratio thereof. Can be simplified.

Further, according to the present embodiment, when the positions of the seedling transplanting machine 1 have not changed even though the left and right front wheel axles 17 and 18 are differentially locked, the transmission of the driving force is cut off during turning. Since the rear wheel clutch is configured to be switched to the on state, the traction force of both the left and right rear wheels 9 can be used to eliminate the idling of the front wheels 8 and 9. Further, by switching the rear wheel clutch to the engaged state only when the slip is not eliminated by the diff locks of the left and right front wheels 8, it is possible to eliminate the slip while minimizing the deviation from the planned route. can.

In addition, according to the present embodiment, if the position of the seedling transplanting machine 1 does not change even after the rear wheel clutch is switched to the engaged state, the steering handle 56 is steered to the straight-ahead position, so that the front wheels are steered. It is possible to easily eliminate the idling state of the 8 and the rear wheel 9.

Further, according to the present embodiment, by lowering the seedling planting unit 63 to the working position, a part of the power of the seedling transplanting machine 1 is not divided into the lift of the seedling planting unit 63, and the power for running is not used. It is possible to increase the traction force and make it easier to eliminate the idling state of the front wheels 8 and the rear wheels 9.

Further, according to the present embodiment, the controller 87 deviates from the working area (in the present embodiment, the central area 210 and the peripheral areas 211 to 214) when the seedling transplanting machine 1 travels a predetermined distance. As a result of the determination as to whether or not the work area is not deviated, the hydrostatic continuously variable transmission 25 is configured to output output and run, so that safety is ensured and the machine body is protected. be able to.

FIG. 14 is a block diagram of a control system, a detection system, an input system, a display system, a drive system, and a communication system of the seedling transplanting machine 1 according to another preferred embodiment of the present invention.

In this embodiment, in addition to the above-described embodiment, the communication system of the seedling transplanting machine 1 includes a communication unit 99 that exchanges data with the communication unit 101 of the mobile terminal 100 by wireless connection.

The seedling transplanting machine 1 according to the present embodiment calculates the slip ratio of the rear wheel 9 while automatically traveling on the field 200, and uses the slip ratio as the frequency of turning on and off the side clutch of the rear wheel 9 in the pumping clutch. , It is configured to feed back to the operation interval of the differential locks of the front wheel axles 17 and 18. First, the method of calculating the slip ratio of the rear wheel 9 will be described in detail below.

In the present embodiment, the controller 87 of the seedling transplanting machine 1 manually travels through the peripheral regions 211 to 213 of the field 200 in order, when traveling straight through the central region 210 of the field 200, and when traveling straight through the central region 210 of the field 200, and the southern part of the field 200. And when turning around the peripheral areas 212 and 214 in the north, the slip ratio of the rear wheels 9 is calculated, and when traveling straight, in the central part of the central area 210 and the part close to the shore, respectively. , Calculate the slip ratio of the rear wheel 9.

Specifically, the controller 87 normally moves the actual moving distance of the seedling transplanting machine 1 calculated from the change in the position information acquired by the GNSS receiver 130 at each timing of teaching, straight running, and turning. Is divided by the moving distance of the seedling transplanting machine 1 estimated from the detection signal (rotation number) of the rear wheel rotation sensor 29, and the value calculated is subtracted from 1.

Further, when the radio wave cannot be acquired by the GNSS receiver 130 at the time of turning, the controller 87 determines that the steering handle 56 is in the end-turning state (the steering wheel cannot be turned any more and is determined by the steering sensor 58). The slip ratio is calculated based on the rotation speed of the rear wheel 9 (the rotation speed of the rear wheel axle 82) detected by the rear wheel rotation sensor 29. In this way, by counting the number of rotations of the rear wheels 9 only in the end-off state, the influence of the speed at which the steering handle 56 is steered can be eliminated. The rotation speed of the rear wheel 9 is counted at a position where the direction of the aircraft is changed by 90 degrees from the orientation of the aircraft at the planting end position (detected by the directional sensor 80), that is, at the turning center position, and then turning. The latter half may be configured to be corrected. Further, by detecting the change in the steering angle of the steering handle 56 per the rotation speed of the rear wheels 9, the slip ratio of the rear wheels 9 can be calculated without using the GNSS receiver 130 at the time of turning.

In the present embodiment, the slip ratio calculated as described above is configured to be fed back to various controls as described below during traveling.

First, the controller 87 is configured to automatically adjust the timing and operation interval of the operation start of the pumping clutch according to the slip ratio. For example, since the slip ratios tend to be similar between the north shore of the "first row" and the north shore of the "third row" shown in FIG. 7, the vehicle ran in the "first row". Immediately after, if the slip ratio of the rear wheel 9 calculated when turning around the peripheral region 212 on the north side is high, immediately after traveling north on the "third row", turning around the peripheral region 212 on the north side. At that time (that is, at the time of turning two times ahead of the turning when the slip ratio is calculated), the operation start timing and the operation interval are adjusted so that the pumping clutch is operated for a long time. In this way, smooth turning is achieved by taking a large amount of time for the driving force to be transmitted to the rear wheels 9 inside the turning.

Secondly, the controller 87 is configured to calculate between the actual stocks according to the calculated slip ratio of the rear wheels 9 and change the fertilization amount by the fertilization device 26 according to the calculated gaps between the actual stocks. With this configuration, even in a place having a high slip ratio in the field 200, the fertilizer can be sprayed in an appropriate amount over the entire field 200 without sprinkling too much fertilizer.

Thirdly, the controller 87 is configured to appropriately adjust the seedling amount according to the calculated slip ratio of the rear wheel 9.

Fourth, the controller 87 corrects the steering speed, that is, the rotation of the engine 7 and the speed of the motor, and further corrects the steering amount and the steering time (number of pulses) of the steering handle 56 to improve the steering accuracy. It is configured to let you.

Fourth, the controller 87 is configured to change the rotation speed of the central leveling rotor 31 and the pair of left and right leveling rotors 32 (see FIG. 1) according to the slip ratio of the rear wheels 9. With this configuration, it is possible to prevent the central leveling rotor 31 and the pair of left and right leveling rotors 32 from sneaking into the surface of the field 200 when the slip ratio is high, and when the slip ratio is low, the central leveling rotor 31 and It is possible to prevent a situation in which a pair of left and right leveling rotors 32 pushes mud.

Fifth, the controller 87 sets the operating interval of the diff locks of the left and right front wheels 8 when the traveling wheels 8 and 9 slip while turning the seedling transplanting machine 1 when the seedling transplanting machine 1 turns two times before (FIG. FIG. It is configured to be adjusted according to the slip ratio of the rear wheel 9 calculated at the time of the previous turn adjacent to the west side in No. 7.

Here, in the present embodiment, if the traveling wheels 8 and 9 slip while the seedling transplanting machine 1 is turning, the diff locks of the left and right front wheels 8 are intermittently operated. By adjusting the operation interval so that the diff lock time becomes longer, it is possible to prevent an excessive load from being applied to the left and right front wheel axles 17 and 18 and the left and right front wheels 8. Regarding the diff locks of the left and right front wheels 8, not only the operation interval but also the operation start timing may be further adjustable.

Further, the controller 87 measures the slip ratio of the rear wheels 9 in the peripheral regions 211 to 214 of the field 200 calculated at the time of teaching on the second route (shown by the gray arrow in FIG. 7) and the seedlings. It is configured to be used for planting. With this configuration, even when the peripheral regions 212 and 214 are roughened by turning, the influence thereof can be eliminated.

FIG. 15 is a flowchart showing a control flow until the controller 87 detects the idling of the traveling wheels 8 and 9 when the seedling transplanting machine 1 shown in FIG. 14 turns by automatic traveling and further eliminates the idling. be.

As shown in FIG. 15, in the present embodiment, the controller 87 first determines whether or not the seedling transplanting machine 1 is turning (step sss1).

Specifically, the controller 87 acquires the detection value of the steering angle of the steering handle 56 from the steering sensor 58, and when the steering angle of the current steering handle 56 exceeds a predetermined angle, the seedling transplanting machine. It is determined that 1 is turning, and if not, it is determined that the seedling transplanting machine 1 is not turning.

As a result of the determination, when it is determined that the seedling transplanting machine 1 is not turning, the controller 87 determines that the value detected by the controller 87 from the steering sensor 58 until the steering angle of the steering handle 56 exceeds a predetermined angle. Acquisition and judgment are repeated.

On the other hand, when it is determined that the seedling transplanting machine 1 is turning as a result of the determination, the controller 87 determines whether or not the traveling wheels 8 and 9 are idling (step sss2).

In the present embodiment, between the process (ii) and the process (iii) shown in FIG. 8, the number of rotations of the front wheel 8 located on the outside during a predetermined time during turning is determined by the number of rotations of the front wheel 8 located on the inside. When the number of revolutions becomes substantially the same as the number of revolutions in time, the controller 87 determines that the traveling wheels 8 and 9 are idling (toward the idling state). With such a configuration, slipping of the traveling wheels 8 and 9 can be detected earlier and more accurately than in the case of the above embodiment, and therefore, a situation such as the traveling wheels 8 and 9 getting stuck in the culvert can be prevented. can do. As in the case of the above embodiment, depending on this determination, it is possible to directly detect the idling of the front wheels 8 of the front and rear traveling wheels 8 and 9, but when the front wheels 8 are idling. It is presumed that the traction force is insufficient and the rear wheel 9 is also idling.

Further, in the present embodiment, in the vicinity of the portion where the slip ratio of the rear wheel 9 is increased during teaching, the sampling rate of slip detection of the traveling wheels 8 and 9 when planting seedlings is made finer. It is configured to be set. With such a configuration, slipping of the traveling wheels 8 and 9 can be detected and dealt with at an early stage in step sss2, and a situation in which the tillage board is damaged can be prevented. In addition to teaching, when traveling in the vicinity of the place where the idling has occurred by using the past idling data on the online storage, the sampling rate of the idling detection of the traveling wheels 8 and 9 is set to the normal sampling rate. It may be configured to be set more finely than when traveling.

As a result of determining whether or not the traveling wheels 8 and 9 are idling, if the traveling wheels 8 and 9 are not idling, as shown in FIG. 15, whether or not the seedling transplanting machine 1 is turning. Return to the judgment of.

On the other hand, as a result of the determination, when the traveling wheels 8 and 9 are idling, the controller 87 drives the diff lock motor 16 (see FIG. 3) and differentially rotates the left and right front wheel axles 17 and 18. (Step sss3). In this embodiment, as described above, the differential rotations of the left and right front wheel axles 17 and 18 are intermittently restricted, and the interval between them is two times before the turn (adjacent to the west side in FIG. 7). It is determined according to the slip ratio of the rear wheel 9 calculated at the time of the previous turn).

Next, the controller 87 determines whether or not the idling of the traveling wheels 8 and 9 has been eliminated (step sss4).

In the present embodiment, the controller 87 eliminates the idling of the traveling wheels 8 and 9 when a predetermined time elapses after the differential rotation of the left and right front wheel axles 17 and 18 is restricted. If the predetermined time has not elapsed, it is determined that the idling of the traveling wheels 8 and 9 has not been resolved. With this configuration, the effect of auto differential can be suppressed when traveling at low speed.

As a result of the determination, if the idling of the traveling wheels 8 and 9 is not resolved, the determination by the controller 87 is repeated until a predetermined time elapses.

On the other hand, when the idling of the traveling wheels 8 and 9 is eliminated, the controller 87 drives the diff lock motor 16 and allows the differential rotation of the left and right front wheels 17 and 18 (step sss5).

On the other hand, in the present embodiment, in order to detect the contact of an intruder in a place where the seedling planting work has not been performed yet when automatically traveling on the first route, the floor step 60 of the seedling transplanting machine 1 Below the front is a bumper and a movable extension (not shown) attached to the bumper. A limit sensor is attached to the extension portion, and the controller 87 is configured to stop the HST output when the contact is detected by the limit sensor.

The extension is configured to be retractable below the front of the floor step 60 when not in use, and by the operator after teaching has been performed and before automatic driving on the first path has begun. , Pulled out in front of the seedling transplanting machine 1. When the limit sensor detects that the extension portion is housed below the front portion of the floor step 60, the controller 87 is configured not to perform automatic traveling.

With such a configuration, when the seedling transplanting machine 1 automatically travels on the field 200, the contact of an intruder can be reliably detected and the HST output can be stopped.

Further, in the present embodiment, communication is periodically performed between the machine body and the mobile terminal 100 (pins are skipped), and when communication is not possible, the controller 87 causes the traveling vehicle 2 that automatically travels to stop. It is configured in. With such a configuration, it is possible to prevent the seedling transplanting machine 1 from becoming uncontrollable when there is no observer (worker or manager).

Further, in the present embodiment, the seedling transplanting machine 1 detects the communication distance with the mobile terminal 100, and when the mobile terminal 100 is approaching at a speed equal to or higher than a predetermined speed (the change in the approaching distance is constant). In the above cases), the HST output is configured to be suppressed or stopped. Therefore, when the worker or the manager of the field 200 approaches the seedling transplanting machine 1 with the mobile terminal 100 in order to confirm the error state and the working condition of the machine, the seedling transplanting machine automatically runs. The traveling speed of 1 can be suppressed or stopped.

Further, when a communication error occurs between the seedling transplanting machine 1 and the mobile terminal 100, the mobile terminal 100 is configured to display an alert on the display and notify the operator or the administrator. ..

Further, the seedling transplanting machine 1 can detect an intruder on the automatic traveling route in the field 200 by communicating with a smartphone or other communication device (different from the mobile terminal 100) approaching the machine body. In this embodiment, the detection range (communication range) is set only in front of the seedling transplanting machine 1, so that a small-scale configuration can be achieved.

In the present embodiment, before determining the idling of the traveling wheels 8 and 9, it is determined in advance whether or not the seedling transplanting machine 1 is turning, and traveling is performed only when the seedling transplanting machine 1 is turning. Since it is configured to determine the idling of the wheels 8 and 9, it prevents the front wheel 8 from diff-locking while planting the seedlings, and hinders small turning running near obstacles accompanied by planting the seedlings. You can prevent the situation.

Further, in the present embodiment, since the seedling transplanting machine 1 is configured to sense (detect) the idling of the traveling wheels 8 and 9 only when the seedling transplanting machine 1 is turning, the tightness of the system is suppressed. The load on the controller 87 can be reduced.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

For example, in each of the embodiments shown in FIGS. 1 to 15, a seedling transplanter is mentioned as an example of a work vehicle, but the work vehicle according to the present invention may be composed of a combine, a tractor, or the like. good. In addition, the work machine attached to the work vehicle can be configured not only as a seedling planting unit 63 but also as a tiller, a ground leveling machine, or the like.

Further, in each of the embodiments shown in FIGS. 1 to 15, the front wheel rotation sensor 21 is configured to be able to detect the rotation speeds of the front wheel axles 17 and 18, but the rotation speeds of the front wheel axles 17 and 18 are determined. It may be configured to detect.

Further, in each of the embodiments shown in FIGS. 1 to 15, the differential rotation of the front wheel axles 17 and 18 (and the front wheels 8) is limited when idling of the traveling wheels 8 and 9 is detected. Although it is configured, it may be configured to limit the differential rotation of the left and right rear wheel axles 82, and limit the differential rotation of both the front wheel axles 17 and 18 and the rear wheel axle 82, respectively. It may be configured.

Further, in each of the embodiments shown in FIGS. 1 to 15, the traveling wheels 8 and 9 are configured to detect idling based on the rotation speeds L and R of the left and right front wheel axles 17, but traveling. The slip detection means for the wheels 8 and 9 is not particularly limited. For example, the actual travel distance of the seedling transplanter 1 acquired by the GNSS receiver 130 and the travel distance estimated based on the detection signal of the rear wheel rotation sensor 29 are corrected based on the detection value of the steering sensor 58. If the actual travel distance is equal to or less than a predetermined ratio of the estimated travel distance, the controller 87 may determine that the traveling wheels 8 and 9 are idling. Further, the rotation speeds of the front wheel axles 17 and 18 are differentiated, and when the differentiation result (change amount) becomes 0 or the same value as the rear wheel rotation speed, the traveling wheels 8 and 9 slip. It may be determined that it is. In this case, since the rotation speed detection on the front wheel side can be performed in one place, even if one of the left and right front wheel rotation sensors 21 fails, the front wheel 8 (and extension) can be detected only by the other front wheel rotation sensor 21. Therefore, it is possible to detect the idling of the rear wheel 9). Furthermore, the number of revolutions of the front wheels 8 within a fixed time is differentiated, and when the amount of increase turns negative, it is assumed that the traveling wheels 8 and 9 are heading for idling, and the left and right front wheel axles 17 and 18 are diff-locked. It may be configured. With such a configuration, it is possible to accurately detect immediately before idling. Further, while comparing the rotation speed of one of the left and right front wheel axles 17 and 18 with the rotation speed of the left and right rear wheels 9 having the higher rotation speed, the ratio is determined to be above or below a certain level. If this happens, it may be determined that the traveling wheels 8 and 9 are idling. In this case, the front wheel rotation sensor 21 can be attached only to the left and right sides of the front wheel axles 17 and 18.

In addition, in each of the embodiments shown in FIGS. 1 to 15, the front wheel 8 is diff-locked, the rear wheel clutch is switched to the engaged state, the steering handle 56 is steered to the straight-ahead position, and the seedling planting portion 63 is lowered. After various torque recovery operations (operations for recovering the traction force by the traveling wheels 8 and 9) such as are performed, the position information of the seedling transplanting machine 1 changes, the amount of rotation of the left and right front wheel axles 17 and 18 and the like. However, the means for detecting the elimination of the idling of the traveling wheels 8 and 9 is not limited to these. For example, the distance between the left and right front wheels 8 before the diff lock and after the diff lock (actual movement distance) is equal to or greater than a predetermined ratio (50%) of the movement distance assumed when the traveling wheels 8 and 9 do not slip. In the case of the above), it may be considered that the idling state has been eliminated, and the torque recovery operation such as the diff lock may be terminated. With this configuration, the amount of deviation from the automatic traveling route can be minimized. Further, the means for detecting the elimination of the idling of the traveling wheels 8 and 9 after the torque recovery operation such as the differential lock of the front wheel 8 and the switching of the rear wheel clutch to the on state is performed is not limited to the controller 87. After the torque recovery operation is stopped by 87, the effect of torque recovery may be entrusted to the operator, and the controller may be configured to move to the next control based on a reliable judgment and input by the operator. In this case, the connection time (time in the on state) of the rear wheel clutch (side clutch) may be configured to be performed by the input of the operator, and the torque recovery operation is executed by the operation from the remote controller provided separately. Alternatively, it may be configured to be stoptable.

Further, in each of the embodiments shown in FIGS. 1 to 15, the automatic traveling path data is stored in the storage unit 93, and the automatic traveling lever 79 swings upward in a state where the automatic traveling switching switch 78 is turned on. The method of starting the automatic running of the seedling transplanting machine 1 by the operator (instructing the machine to start the automatic running) is configured so that the automatic running based on the control of the controller 87 is started by the dynamic operation. The method) is not particularly limited to this.

Further, in each of the embodiments shown in FIGS. 1 to 15, changes in the position information (position coordinates) of the seedling transplanting machine 1 acquired by the GNSS receiver 130 and the rotation speeds of the left and right front wheels 8 are detected. As a result, slipping of the traveling wheels 8 and 9 is detected, the left and right front wheels 8 are diff-locked, the rear wheels 9 are switched to the engaged state, the steering handle 56 is steered to the straight-ahead position, and the planting portion 63 is lowered. It is configured to automatically eliminate the idling of the traveling wheels 8 and 9 by executing various torque recovery operations, but similarly, the idling of the traveling wheels 8 and 9 is detected and various torques are detected. By performing the recovery operation, it is possible to prevent the seedling transplanting machine 1 from sinking in the field 200. In this case, the GNSS receiver 130 is normally configured to be used, and when radio waves cannot be acquired, the steering angle of the steering handle 56 does not change, and the rotation speed of the front wheels 8 or the rear wheels 9 is increased. When the number is increasing, it may be determined that the seedling transplanting machine 1 is sunk, and various torque recovery operations may be performed. Further, the means for detecting idling of the traveling wheels 8 and 9 is not particularly limited, and for example, it is determined whether or not the left and right rear wheels 9 are rotating during turning, and as a result, the result is determined. When one of the left and right rear wheels 9 is not rotating, it is presumed that the traveling wheels 8 and 9 are idling and the seedling transplanting machine 1 is sunk. It may be configured to do everything or selectively. Further, the content of the torque recovery operation may be automatically selected according to the location in the field 200 when the sinking of the seedling transplanting machine 1 is detected. Specifically, when the sinking of the seedling transplanting machine 1 is detected while traveling straight, the left and right front wheels 8 are diff-locked over a constant pulse to suppress the deviation in the traveling direction. be able to. On the other hand, if the sinking of the seedling transplanter 1 is detected during the turning, only the pumping clutch is applied in the first half of the turning, and the left and right front wheels 8 are referred to by the diff locks of the left and right front wheels 8 in the second half of the turning. By operating the diff lock and the pumping clutch in a coordinated manner, the driving force is transmitted to all the traveling wheels 8 and 9 to increase the behavior of the aircraft, not only to escape from the sunken state but also to cross the shore. It is possible to prevent the aircraft from advancing and ensure the safety of the seedling transplanting machine 1. Further, an escape mode for forcibly performing various torque recovery operations may be configured to be executable, and an escape mode button for executing this escape mode may be separately provided in the vicinity of the cockpit 48. In this case, the escape mode may be provided. Various torque recovery operations may be performed only while the button is pressed. Further, the operation content of the escape mode may be configured so that the forward mode when moving forward and the reverse mode when moving backward are different from each other. Specifically, the escape mode button is pressed during reverse movement. While the seedling planting portion 63 is raised (to protect the seedling planting portion 63), the front wheel 8 is differentially locked (the differential rotation of the left and right front wheel axles 17 and 18 is restricted), and the steering handle 56 goes straight. Steering to the position, both the left and right rear wheel 9 side clutches are in the on state (four-wheel drive state), configured to output from the HST25, and while the escape mode button is pressed when moving forward, the seedlings The planting part 63 is lowered (to obtain buoyancy and the force to keep lifting the seedling planting part is directed for running), and the front wheel 8 is diff-locked (the differential rotation of the left and right front wheel axles 17 and 18 is restricted. ), The steering handle 56 may be steered to a straight-ahead position, both the left and right rear wheel 9 side clutches may be in the on state (four-wheel drive state), and the HST 25 may be configured to output. Further, the torque recovery operation performed while the escape mode button is pressed may be configured to be arbitrarily selectable from various torque recovery operations.

Further, in each of the embodiments shown in FIGS. 1 to 15, the left and right front wheels 8 are configured to be diff-locked when the traveling wheels 8 and 9 are detected to slip, but the left and right wheels 8 are left and right. If the position of the seedling transplanter 1 acquired by the GNSS receiver deviates from the set work area while the front wheel 8 is diff-locked, the output of the hydrostatic continuously variable transmission 25 is stopped. It may be configured as follows. With such a configuration, it is possible to protect the airframe and eliminate the need for correction work such as supplementary planting.

Further, in each of the embodiments shown in FIGS. 1 to 15, when slipping of the traveling wheels 8 and 9 is detected, the left and right front wheels 8 are automatically diff-locked. Further, an auto on / off switch for switching whether or not to allow the differential lock by the controller 87 may be provided in the vicinity of the driver's seat 48, and further, the front wheel axle is forcibly operated by being operated at any time. A differential actuation switch that limits or allows differential rotation of 17, 18 may be provided. Further, when the diff operation switch is provided, the operation state of the diff lock may be compared with the operation state to identify an error portion and display it on the monitor 61. Specifically, when the diff locks of the pair of front wheel axles 17 and 18 are actually operated or released and the operation or release operation is not performed, an electrical error is displayed on the monitor 61 or the diff lock motor. It may be configured to display so as to prompt the inspection from 16 to the diff lock arm 19. With such a configuration, when a problem occurs, it is possible to easily grasp whether it is an electrical system trouble or a mechanical trouble, and it is possible to improve safety. Further, the error notification may be performed on the monitor 61 or the like when the target value of the diff lock motor 16 is switched between the released state and the operating state. By configuring in this way, it is possible to specify the timing of error notification and eliminate the need to perform error notification from beginning to end. Furthermore, if the diff lock is actually operating even though the diff lock is released, or if the diff lock is not actually operating even though the diff lock is operated. After waiting for the specified amount of drive rotation, it is determined whether or not it will be released or activated again, and if it is not released or activated, a wording indicating a mechanical error or a wording prompting an inspection inside the transmission, or The wording urging the vehicle to stop may be displayed on the monitor 61, or a signal may be sent to the remote controller provided separately. With this configuration, it is possible to notify the operator of mechanical troubles in the traveling system of high importance. Further, when the signal is sent to the remote controller side, an important error can be notified to the operator even in the remote control state in the unmanned operation. It should be noted that the specified amount of drive rotation can be adjusted to the manual operation feeling by configuring the amount at the time of release to be larger than the amount at the time of operation.

Further, in each of the embodiments shown in FIGS. 1 to 15, when slipping of the traveling wheels 8 and 9 is detected, a torque recovery operation such as automatically diff-locking the left and right front wheels 8 is performed. However, if the steering handle 56 is steered to a specified value (180 °, etc.) while the output is being output from the hydrostatic continuously variable transmission 25, the torque recovery operation is stopped. , May be configured to return to the default control. With this configuration, stop control can be performed in the same manner even when the automatic driving and the manual driving are switched or when the position information cannot be acquired by the GNSS receiver.

Further, in each of the embodiments shown in FIGS. 1 to 15, the diff locks of the left and right front wheels 8 are configured to be continued until the idling of the traveling wheels 8 and 9 is eliminated, but intermittently. By activating the diff locks of the left and right front wheels 8, the load can be released especially when turning. In this case, the idling of the traveling wheels 8 and 9 may be determined immediately after the intermittent operation.

Further, in the embodiment shown in FIGS. 1 to 12, the diff lock state of the front wheels 8 is monitored by the limit switch 59 that mechanically detects the diff lock (limitation of differential rotation) of the pair of front wheel axles 17 and 18. Although it is configured to be displayed on the 61, the diff lock of the front wheels 8 is detected based on the rotation speeds of the left and right front wheel axles 17 and 18, and the diff lock is displayed on the monitor 61 without a time lag. Can be detected, and the limit switch 59 can be omitted.

In addition, in the embodiment shown in FIGS. 1 to 12, when the rotation speed of the engine 7 is less than the first predetermined value when the automatic running start operation is performed, the first It is configured to drive the throttle motor 97 so as to be equal to or more than a predetermined value, but when it is less than the first predetermined value, the rotation speed of the engine 7 is a second predetermined value different from the first predetermined value. It may be configured to raise to.

Further, in the embodiment shown in FIGS. 1 to 12, when the rotation speed of the engine 7 is less than the first predetermined value when the automatic running start operation is performed, the first predetermined value is obtained. It is configured to drive the throttle motor 97 so as to be equal to or higher than the value, but when the rotation speed of the engine 7 is less than the first predetermined value, the output of the hydrostatic continuously variable transmission 25 (HST) is reached. The operation or the operation of increasing the output may be performed so that the rotation speed of the engine 7 is increased prior to the steering of the steering handle 56 (an example of the steering device). This configuration also prevents the power steering 108 from insufficient oil pressure, and enables smooth automatic steering (rotation of the steering handle 56 and accompanying steering of the front wheels 8 as steering wheels). In this case, it may be necessary to recalculate (correct) the automatic traveling path by the output of the hydrostatic continuously variable transmission 25.

Further, in the embodiment shown in FIGS. 1 to 12, when the rotation speed of the engine 7 is less than the first predetermined value when the automatic running start operation is performed, the first predetermined value is obtained. It is configured to drive the throttle motor 97 so as to exceed the value, but when the rotation speed of the hydraulic pump does not reach the specified value when the automatic running start operation is performed, the steering handle 56 The engine 7 may be configured to increase the number of revolutions prior to steering. In this case as well, the hydraulic pressure in the power steering 18 can be secured, and therefore the automatic steering can be started smoothly.

Further, in the embodiment shown in FIGS. 1 to 12, the controller 87 sets a tentative target value so that the control amount of the steering motor 57 gradually approaches the control target value, and outputs a control signal. However, when the difference between the tentative target value and the control target value becomes less than a predetermined value, a control signal corresponding to the control target value itself is output to the steering motor 57. It may be configured as follows.

Further, in the embodiment shown in FIGS. 1 to 12, as shown in FIG. 6B, the motor side gear 109 and the internal gear 106 mesh with each other via the hub damper 110, whereby the steering motor The vibration of 57 is configured to travel through the upper shaft 83 and not be transmitted to the steering handle 56, but for example, the hub damper 110 is attached only to the lower part of the motor side gear 109, and the upper part thereof is not covered by the hub damper 110. In this state, a separate motor is provided so that the internal gear 106 (or the internal gear 106 and the upper shaft 83) can slide up and down, so that the internal gear 106 meshes with the motor side gear 109 via the hub damper 110 ( It may be possible to switch between a state in which the internal gear 106 is located below) and a state in which the internal gear 106 meshes with the motor side gear 109 without passing through the hub damper 110 (when the internal gear 106 is located above). With this configuration, vibration is not transmitted via the hub damper 110 while the seedling transplanting machine 1 is automatically running, and steering is performed without going through the hub damper 110 while the seedling transplanting machine 1 is manually running. The torque from the steering wheel 56 can be easily transmitted to the steering sensor 58 having the encoder.

Further, in the embodiment shown in FIGS. 1 to 12, by using the hub damper 110, vibration from the steering motor 57 to the steering handle 56 is performed even though the steering handle 56 to the pitman arm are mechanically connected. However, it is not always necessary to mechanically connect the steering handle 56 to the pitman arm, and the steering handle 56 and the upper shaft 83 are physically separated from the other steering mechanism 66. The rotation operation force of the steering handle 56 is not used as the steering force, the input torque due to the rotation operation is electrically detected by the torque sensor 111, and a pair of left and right front wheels are operated by a motor or the like according to the detected value. The orientation of 8 may be changed. With this configuration as well, it is possible to prevent vibration of the motor or the like from being transmitted to the steering handle 56. In addition, the handle layout can be performed without restrictions, and the productivity can be improved by eliminating the handle phase. Further, in this case, when the manual driving is switched to the automatic driving, the steering wheel 56 is set to the default position and automatically steered by the motor dedicated to the steering wheel, so that the steering wheel phase is taken into consideration. Can be done. The position (steering angle) of the steering handle 56 may be configured to be followed by a dedicated motor according to the automatic steering amount, whereby the state (orientation) of the front wheel 8 as the steering wheel can be changed. It can be monitored by the steering wheel 56.

Further, in the embodiment shown in FIGS. 1 to 12, when the traveling wheels 8 and 9 are idling, the differential rotation of the left and right front wheel axles 17 and 18 is restricted (differential lock). However, when the traveling wheels 8 and 9 are idling, the differential rotation of the left and right rear wheel axles 82 may be configured to be diff-locked, and the front and rear axles 17, 18 and 82 may be configured. Each of them may be configured to be diff-locked so that the left and right rotations are the same.

Further, in the embodiment shown in FIGS. 1 to 12, the controller 87 is configured to first detect the idling of the traveling wheels 8 and 9 in step s1 (see FIG. 9), but in step s1. Before entering, it may be determined in advance whether or not the seedling transplanting machine 1 is turning, and only when the seedling transplanting machine 1 is turning, the process may be configured to proceed to step s1.

Further, in each of the embodiments shown in FIGS. 1 to 13, when the driving force is transmitted to one of the left and right front wheels 8 in an unbalanced manner and the other is almost non-rotating, the step in FIG. 9 is performed. As shown in step SS3 in s1 and FIG. 13, the front wheel rotation sensor 21 is configured to detect it only once and diff lock the left and right front wheels 8, but the left and right front wheel axles 17, By configuring the number of slip detections by detecting the number of revolutions of 18 as a plurality of times, it may be configured to suppress the malfunction of the diff lock. Further, the idling of the traveling wheels 8 and 9 may be detected by detecting the rotation speeds of the left and right front wheel axles 17 and 18 at any place in the field input in advance.

Further, in the embodiment shown in FIG. 13, when there is an HST output and the seedling transplanting machine 1 is not allowed to move, the presence or absence of idling of the front wheel 8 is determined, and as a result of the determination, the front wheel 8 is determined. Is configured to diff-lock the left and right front wheels 8 when is idling, and return to the HST output determination (step ss1) when the front wheels 8 are not idling, but the front wheels 8 are idling. If not, the rear wheel clutch that has been disengaged may be engaged (switched to the on state). Even in this case, the traction force can be increased. When slipping of the traveling wheels 8 and 9 is detected, the left and right front wheels 8 are switched to the diff locks (the left and right front wheel axles 17 and 18 are diff locks) and the rear wheel clutches (side clutches) are switched to the engaged state. May be configured to be performed simultaneously, or may be configured to be performed alternately, and may be configured to find out which of the four wheels (traveling wheels 8 and 9) is the cause of the slip.

In the embodiment shown in FIG. 13, the front wheel axle 17, It is configured to detect the idling of the traveling wheels 8 and 9 based on the number of revolutions of 18, but there is no change in the position information of the seedling transplanter when there is an output of the hydrostatic continuously variable transmission 25. In this case, it is determined that the traveling wheels 8 and 9 are idling, and the front wheel axles 17 and 18 are differentially locked without determining the presence or absence of idling based on the rotation speeds of the front wheel axles 17 and 18. May be good. In this way, in limiting the differential rotation of the left and right front wheel axles 17 and 18, the two points of the output from the hydrostatic continuously variable transmission 25 and the position change of the work vehicle are also required. It is possible to prevent a situation in which the differential rotation of the left and right axles is accidentally restricted when it is not necessary.

Further, in the embodiment shown in FIG. 13, the rear wheel clutch is switched to the engaged state only when the slip is not eliminated by the diff locks of the left and right front wheels 8, but the vehicle travels. When the wheels 8 and 9 slip, first, the rear wheel clutch is switched to the on state, and the left and right front wheels 8 are diff-locked only when the slip of the traveling wheels 8 and 9 is not eliminated. It may be configured. In this way, by configuring the differential rotation mechanism 15 to allow the differential rotation of the left and right front wheels 8 as much as possible, it is easy to point the nose at the target, and it is easy to correct the trajectory after the idling is eliminated. Can be done.

Further, in the second embodiment shown in FIG. 13, the output amount of the hydrostatic continuously variable transmission 25 in the torque recovery operation shown in step ss12 is defined as a constant pulse amount (specified amount, fixed amount amount). Although it is configured, the output amount of the hydrostatic continuously variable transmission 25 is set as a variable value, and based on the acquired position information of the seedling transplanter 1 and the distance to the shore or the planted area of the seedlings. It may be configured to determine the output amount. With such a configuration, safety can be ensured and the airframe can be protected.

Further, in the embodiment shown in FIG. 13, the controller 87 determines whether or not the seedling transplanting machine 1 is moving based on the presence or absence of a change in the position information, and as a result, the seedling transplanting machine 1 is moved. Although it is configured to determine the idling of the traveling wheels 8 and 9 only when the seedling transplanting machine 1 is present, the rotation speeds of the front wheel axles 17 and 18 are determined without determining whether or not the seedling transplanting machine 1 is moving. As a result of determining whether or not the traveling wheels 8 and 9 are idling (see step ss3 in FIG. 13), if the traveling wheels 8 and 9 are idling, the front wheel axles 17 and 18 are diff-locked. It may be configured as. With this configuration, the rotation speeds of the left and right front wheel axles 17 and 18 (rotation of the front wheels 8) are detected, and the idling of the traveling wheels 8 and 9 (particularly the front wheels 8) is detected only by calculating the ratio. Therefore, the configuration of the work vehicle (seedling transplanter) can be simplified, and even when the GNSS radio wave cannot be received, the idling of the traveling wheels 8 and 9 can be detected. Further, in this case, since the sampling rate can be changed and the sensor slowness can be adjusted, an adjustment mechanism using a dial or the like can be easily provided.

Further, in the embodiment shown in FIG. 13, even though the left and right front wheels 8 are differentially locked, the idling of the traveling wheels 8 and 9 is not eliminated, and the seedling transplanting machine 1 is turning. Only in the case, the side clutch of the rear wheel 9 in the off state is configured to be switched to the on state, but when driving the solenoid valve 103 and switching the side clutch of the rear wheel 9 to the on state, seedling transplantation is performed. It is not always necessary that the machine 1 is turning.

1 Seedling transplanter 2 Traveling vehicle body 3 Main frame 4 Belt type power transmission mechanism 5 Elevating link device 6 Rear frame 7 Engine 8 Front wheels 9 Rear wheels 10 Link base frame 11 Elevating link arm 12 Elevating hydraulic cylinder 13 Front wheel final case 14 Rear wheel transmission Shaft 15 Differential mechanism 16 Diff lock motor 17 Front wheel axle 18 Front wheel axle 19 Diff lock arm 20 Auxiliary transmission mechanism 21 Front wheel rotation sensor 22 On / off pin 23 Diff clutch 24 Auxiliary shift lever 25 Hydrostatic continuously variable transmission 26 Fertilizer application device 27 Fertilizer hopper 28 Rotor cover 29 Rear wheel rotation sensor 30 Mission case 31 Central ground leveling rotor 32 Left and right ground leveling rotor 33 Float sensor 34 Feeding device 35 Forward / backward lever 36 Forward / backward lever sensor 37 Drive shaft 38 Center float 39 Side float 40 Fertilizer hose 41 Rotor blade 42 Planting Depth Frame 43 First Arm 44 Second Arm 45 Through Hole 46 Parallel Link 47 Front Cover 48 Driver's Seat 49 Control Unit
50 Push switch 51 Rear wheel gear case 52 Protruding part 53 Draining notch 54 Operation part 55 Main speed change lever 56 Steering handle 57 Steering motor 58 Steering sensor 59 Limit switch 60 Floor step 61 Monitor 62 Diff lock pedal 63 Seedling planting part 64 Planting device 65 units 66 Steering mechanism 67 Drive shaft 68 Transmission case 69 Planting tool 70 Planting case 71 Seedling outlet 72 Seedling tank 73 Output shaft 74 Spare seedling mounting stand 78 Automatic traveling changeover switch 79 Automatic traveling lever 80 Direction sensor 81 Automatic traveling lever sensor 82 Rear wheel axle 83 Upper shaft 84 Lower shaft 85 Upper link arm 86 Lower link arm 87 Controller 88 Electro-hydraulic valve 89 Processing unit 90 Link sensor 91 RAM
92 ROM
93 Storage unit 95 Planted transmission shaft 96 Engine rotation sensor 97 Throttle motor 99 Communication unit 100 Mobile terminal 101 Communication unit 103 Electromagnetic valve 105 Timer 106 Internal gear 107 Universal joint 108 Power steering 109 Motor side gear 110 Hub damper 111 Torque sensor 112 Gear box 120 Tranion Shaft 121 Tranion Arm 122 Potential Meter 123 Rod 124 Gear 130 GNSS Receiver 150 HST Servo Motor 200 Field 201 Field Side 202 Field Side 203 Field Side 204 Field Side 205 First Planting Start Position 206 Second Planting start position 207 Planting start position in the first row 208 Broken line with an arrow (reference line when straight-ahead assist)
210 Central area 211 Peripheral area 212 Peripheral area 213 Peripheral area 214 Peripheral area 218 Start point 219 End point

Claims (6)

A steering device that steers the left and right running wheels,
The actuator that drives the steering device and
Location information acquisition means to acquire vehicle location information,
A differential device that distributes the driving force to the axles of the left and right traveling wheels,
A controller that controls the tolerance and limitation of the differential rotation of the left and right axles by the differential device,
It is a work vehicle that can run automatically and is equipped with a work machine that can be raised and lowered provided at the rear of the vehicle.
A work vehicle, characterized in that the controller limits the differential rotation of the left and right axles when the traveling wheels are idling. When there is an output from the hydrostatic continuously variable transmission that changes the rotational speed of the traveling wheels and the position information of the vehicle acquired by the position information acquisition means has not changed, the controller The work vehicle according to claim 1, wherein it is determined that the traveling wheels are idling, and the differential rotation of the left and right axles is restricted. When the vehicle is turning, if the ratio of the higher rotation speed to the lower rotation speed of the left and right axle rotation speeds per predetermined time is equal to or higher than the predetermined value, the controller is running. The work vehicle according to claim 1, wherein it is determined that the wheels are idling, and the differential rotation of the axles of the left and right traveling wheels is limited. The traveling wheel is a front wheel.
If the position information of the vehicle acquired by the position information acquisition means has not changed after the differential rotation of the axles of the left and right front wheels is restricted, the controller is further transmitted to the rear wheels. 3. The work vehicle described. If the position of the vehicle acquired by the position information acquisition means has not changed after the clutch in the disengaged state is switched to the on state, the controller further advances the steering device straight by the actuator. The work vehicle according to claim 4, wherein the work vehicle is steered to a position and the work machine is lowered to a work position where work is possible. The controller determines whether or not the vehicle deviates from the work area if the vehicle travels a predetermined distance in a state where the steering device is steered to a straight-ahead position and the work machine is lowered to a work position. The work vehicle according to claim 5, wherein the output is output from the hydrostatic continuously variable transmission only when the result of the determination does not deviate from the work area.

Images