Work vehicle

Abstract

To appropriately stop automatic steering according to a state of an operator.SOLUTION: A work vehicle includes: an operation seat; a vehicle body capable of traveling either by manual steering by a steering wheel or automatic steering by a steering wheel performing steering in an advancing direction so as to match with a traveling planned line parallel to a traveling reference line; a positioning device capable of detecting a position of the vehicle body; a reference line setting switch for setting the position of the vehicle body detected by the positioning device to a start position and an end position of the traveling reference line; a steering changeover switch for changing the steering between the automatic steering and the manual steering; a seating detection device for detecting seating of an operator; a control device for permitting the automatic steering when the seating detection device detects seating and a changeover operation from the manual steering to the automatic steering is made by the steering changeover switch; and a notification device for notifying that the operator has left the operation seat. When the automatic steering is performed, the control device stops the automatic steering when the seating detection device does not detect seating.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, Patent Document 1 is known as an agricultural work machine. The agricultural work machine of Patent Document 1 includes a traveling body capable of switching between manual traveling by manual steering and automatic traveling by automatic steering along a set traveling line set parallel to a reference traveling line, and a switching switch capable of switching between manual traveling and automatic traveling. Further, in the agricultural work machine, after the right instruction button is pressed during traveling along the ridge, the starting point of the reference traveling line is set, and the ending point of the reference traveling line is set by pressing the left instruction button during traveling. That is, the reference traveling line is set before automatic steering.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the agricultural work machine of Patent Document 1, automatic traveling can be easily performed by switching from manual traveling to automatic traveling by a switching switch. Regarding the start and end of automatic traveling, it is necessary to reflect the driver's intention, and it is necessary to stably steer in response to the driver's request even during automatic traveling. Further, it is required that the driver perform automatic traveling in an appropriate state, and it is desirable that the driver be in an appropriate state also regarding the start and end of automatic traveling.

[0005] Therefore, in view of the above problems, an object of the present invention is to provide a work vehicle capable of appropriately performing automatic steering according to the driver's state.

Means for Solving the Problems

[0006] The technical means of the present invention for solving this technical problem is characterized by the following points.

[0007] The work vehicle includes a driver's seat, a steering wheel, manual steering by the steering wheel, a vehicle body capable of traveling either by manual steering of the steering wheel or by automatic steering of the steering wheel to perform steering in the traveling direction so as to coincide with a planned traveling line parallel to the traveling reference line, a prime mover provided on the vehicle body, a traveling device that travels the vehicle body by the power of the prime mover, a positioning device capable of detecting the position of the vehicle body, a reference line setting switch that sets the position of the vehicle body detected by the positioning device to the start position and the end position of the traveling reference line, a steering changeover switch that switches between the automatic steering and the manual steering, a seating detection device that detects the seating of the driver, a control device that permits the automatic steering when the seating detection device detects the seating and there is a switching operation from manual steering to automatic steering by the steering changeover switch, and a notification device that notifies that the driver has left the driver's seat. The control device stops the automatic steering when the seating detection device does not detect the seating while the automatic steering is being performed.

[0008] When the automatic steering is being performed, the control device performs the notification by the notification device when the seating detection device changes from a seating detection state in which the seating is detected to a leaving detection state in which the seating is not detected, and stops the traveling of the vehicle body when the elapsed time of the leaving detection state exceeds a predetermined determination threshold.

[0009] The notification device increases the notification intensity as the elapsed time of the leaving detection state becomes longer.

Advantages of the Invention

[0010] According to the present invention, it is possible to appropriately stop the automatic steering according to the state of the driver.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12A

Figure 12B

Figure 13

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] FIG. 13 is a side view showing an embodiment of the work vehicle 1, and FIG. 13 is a plan view showing an embodiment of the work vehicle 1. In this embodiment, the work vehicle 1 is a tractor. However, the work vehicle 1 is not limited to a tractor, and may be an agricultural machine (agricultural vehicle) such as a combine or a transplanter, or a construction machine (construction vehicle) such as a loader working machine.

[0014] Hereinafter, the front side (in the direction of arrow A1 in FIG. 13) of the driver sitting in the driver's seat 10 of the tractor (work vehicle) 1 is defined as the front, the rear side (in the direction of arrow A2 in FIG. 13) of the driver as the rear, the left side of the driver as the left, and the right side of the driver as the right for description. Also, the horizontal direction, which is the direction orthogonal to the front-rear direction of the work vehicle 1, is described as the vehicle body width direction.

[0015] As shown in FIG. 13, the tractor 1 includes a vehicle body 3, a prime mover 4, and a transmission 5. The vehicle body 3 has a traveling device 7 and is capable of traveling. The traveling device 7 is a device having front wheels 7F and rear wheels 7R. The front wheels 7F may be of a tire type or a crawler type. Also, the rear wheels 7R may be of a tire type or a crawler type.

[0016] The prime mover 4 is a diesel engine, an electric motor, etc., and is configured by a diesel engine in this embodiment. The transmission 5 can switch the driving force of the traveling device 7 by shifting gears, and can also switch the traveling device 7 between forward and reverse. A driver's seat 10 is provided on the vehicle body 3.

[0017] In addition, a connecting portion including a lifting device 8 is provided at the rear of the vehicle body 3. A work device can be detachably attached to the connecting portion. By connecting the work device to the connecting portion, the vehicle body 3 can tow the work device. The work device includes a tilling device for tilling, a fertilizer spreading device for spreading fertilizer, a pesticide spraying device for spraying pesticides, a harvesting device for harvesting, a mowing device for mowing grass, a spreading device for spreading grass, a grass collecting device for collecting grass, a forming device for forming grass, etc.

[0018] As shown in Fig. 1, the transmission 5 includes a main shaft (propulsion shaft) 5a, a main transmission section 5b, an auxiliary transmission section 5c, a shuttle section 5d, a PTO power transmission section 5e, and a front transmission section 5f. The propulsion shaft 5a is rotatably supported by the housing case (transmission case) of the transmission 5, and the power from the crankshaft of the engine 4 is transmitted to the propulsion shaft 5a. The main transmission section 5b has a plurality of gears and a shifter for changing the connection of the gears. The main transmission section 5b changes and outputs (shifts) the rotation input from the propulsion shaft 5a by appropriately changing the connection (meshing) of the plurality of gears with the shifter.

[0019] Similar to the main transmission section 5b, the auxiliary transmission section 5c has a plurality of gears and a shifter for changing the connection of the gears. The auxiliary transmission section 5c changes and outputs (shifts) the rotation input from the main transmission section 5b by appropriately changing the connection (meshing) of the plurality of gears with the shifter.

[0020] The shuttle section 5d has a shuttle shaft 12 and a forward / reverse switching section 13. The power output from the auxiliary transmission section 5c is transmitted to the shuttle shaft 12 via gears and the like. The forward / reverse switching section 13 is composed of, for example, a hydraulic clutch or the like, and switches the rotation direction of the shuttle shaft 12, that is, the forward and reverse of the tractor 1, by engaging and disengaging the hydraulic clutch. The shuttle shaft 12 is connected to the rear-wheel differential device 20R. The rear-wheel differential device 20R rotatably supports the rear axle 21R to which the rear wheels 7R are attached.

[0021] The PTO power transmission section 5e has a PTO propulsion shaft 14 and a PTO clutch 15. The PTO propulsion shaft 14 is rotatably supported and the power from the propulsion shaft 5a can be transmitted thereto. The PTO propulsion shaft 14 is connected to the PTO shaft 16 via gears and the like. The PTO clutch 15 is composed of, for example, a hydraulic clutch or the like, and switches between a state where the power of the propulsion shaft 5a is transmitted to the PTO propulsion shaft 14 and a state where the power of the propulsion shaft 5a is not transmitted to the PTO propulsion shaft 14 by engaging and disengaging the hydraulic clutch.

[0022] The front transmission section 5f has a first clutch 17 and a second clutch 18. The first clutch 17 and the second clutch are capable of transmitting the power from the propulsion shaft 5a. For example, the power of the shuttle shaft 12 is transmitted via gears and a transmission shaft. The power from the first clutch 17 and the second clutch 18 can be transmitted to the front axle 21F via the front transmission shaft 22. Specifically, the front transmission shaft 22 is connected to the front wheel differential device 20F, and the front wheel differential device 20F rotatably supports the front axle 21F to which the front wheels 7F are attached.

[0023] The first clutch 17 and the second clutch 18 are composed of a hydraulic clutch or the like. An oil passage is connected to the first clutch 17, and the oil passage is connected to a first operation valve 25 to which the hydraulic oil discharged from a hydraulic pump is supplied. The first clutch 17 is switched between a connected state and a disconnected state according to the opening degree of the first operation valve 25. An oil passage is connected to the second clutch 18, and the oil passage is connected to a second operation valve 26. The second clutch 18 is switched between a connected state and a disconnected state according to the opening degree of the second operation valve 26. The first operation valve 25 and the second operation valve 26 are, for example, two-position switching valves with solenoid valves, and are switched to a connected state or a disconnected state by exciting or demagnetizing the solenoids of the solenoid valves.

[0024] When the first clutch 17 is in the disconnected state and the second clutch 18 is in the connected state, the power of the shuttle shaft 12 is transmitted to the front wheels 7F through the second clutch 18. As a result, it is four-wheel drive (4WD) in which the front wheels and the rear wheels are driven by power and the rotational speeds of the front wheels and the rear wheels are substantially the same (4WD constant speed state). On the other hand, when the first clutch 17 is in the connected state and the second clutch 18 is in the disconnected state, it becomes four-wheel drive and the rotational speed of the front wheels becomes faster than the rotational speed of the rear wheels (4WD speed increase state). Also, when the first clutch 17 and the second clutch 18 are in the disconnected state, the power of the shuttle shaft 12 is not transmitted to the front wheels 7F, so it becomes two-wheel drive (2WD) in which the rear wheels are driven by power.

[0025] As shown in FIG. 8, the lifting device 8 has a lift arm 8a, a lower link 8b, a top link 8c, a lift rod 8d, and a lift cylinder 8e. The front end of the lift arm 8a is supported so as to be swingable upward or downward at the upper rear part of a case (transmission case) that houses the transmission 5. The lift arm 8a swings (moves up and down) by the drive of the lift cylinder 8e. The lift cylinder 8e is composed of a hydraulic cylinder. The lift cylinder 8e is connected to a hydraulic pump via a control valve 29. The control valve 29 is an electromagnetic valve or the like and expands and contracts the lift cylinder 8e.

[0026] The front end of the lower link 8b is supported so as to be swingable upward or downward at the lower rear part of the transmission 5. The front end of the top link 8c is supported so as to be swingable upward or downward at the rear part of the transmission 5 above the lower link 8b. The lift rod 8d connects the lift arm 8a and the lower link 8b. The working device 2 is connected to the rear parts of the lower link 8b and the top link 8c. When the lift cylinder 8e is driven (expands and contracts), the lift arm 8a moves up and down, and the lower link 8b connected to the lift arm 8a via the lift rod 8d moves up and down. Thereby, the working device 2 swings (moves up and down) upward or downward with the front part of the lower link 8b as a fulcrum.

[0027] The tractor 1 is provided with a positioning device 40. The positioning device 40 can detect its own position (positioning information including latitude and longitude) by a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, and QZSS. That is, the positioning device 40 receives a satellite signal (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellite and detects a position (for example, latitude and longitude) based on the satellite signal. The positioning device 40 has a receiving device 41 and an inertial measurement unit (IMU) 42. The receiving dev The receiving device 41 is a device that has an antenna or the like and receives satellite signals transmitted from positioning satellites, and is attached to the vehicle body 3 separately from the inertial measurement device 42. In this embodiment, the receiving device 41 is attached to a roof rack provided on the vehicle body 3. Note that the attachment location of the receiving device 41 is not limited to the embodiment.

[0028] The inertial measurement device 42 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. It is provided below the vehicle body 3, for example, below the driver's seat 10, and the inertial measurement device 42 can detect the roll angle, pitch angle, yaw angle, etc. of the vehicle body 3.

[0029] As shown in FIG. 1, the tractor 1 is equipped with a steering device 11. The steering device 11 is a device capable of performing manual steering for steering the vehicle body 3 by the driver's operation and automatic steering for automatically steering the vehicle body 3 without depending on the driver's operation.

[0030] The steering device 11 has a steering wheel 30 and a steering shaft 31 that rotatably supports the steering wheel 30. Further, the steering device 11 has an auxiliary mechanism (power steering device) 32. The auxiliary mechanism 32 assists the rotation of the steering shaft 31 (steering wheel 30) by hydraulic pressure or the like. The auxiliary mechanism 32 includes a hydraulic pump 33, a control valve 34 to which the working fluid discharged from the hydraulic pump 33 is supplied, and a steering cylinder 35 that is actuated by the control valve 34. The control valve 34 is, for example, a three-position switching valve that can be switched by the movement of a spool or the like, and switches corresponding to the steering direction (rotation direction) of the steering shaft 31. The steering cylinder 35 is connected to an arm (knuckle arm) 36 that changes the direction of the front wheels 7F. The hydraulic oil is supplied to a control valve 34 and a steering cylinder 35 actuated by the control valve 34. The control valve 34 is, for example, a three-position switching valve that can be switched by the movement of a spool or the like, and switches corresponding to the steering direction (rotation direction) of the steering shaft 31. The steering cylinder 35 is connected to an arm (knuckle arm) 36 that changes the direction of the front wheels 7F.

[0031] Therefore, if the driver grips the steering wheel 30 and operates it in one direction or the other, the switching position and opening degree of the control valve 34 will change corresponding to the rotation direction of the steering wheel 30, and the steering cylinder 35 will expand and contract left or right according to the switching position and opening degree of the control valve 34, so that the steering direction of the front wheels 7F can be changed. That is, the vehicle body 3 can change its traveling direction left or right by manually steering the steering wheel 30.

[0032] Next, the automatic steering will be described.

[0033] As shown in FIG. 2, when performing automatic steering, first, a traveling reference line L1 is set before performing automatic steering. After setting the traveling reference line L1, automatic steering can be performed by setting a planned traveling line L2 parallel to the traveling reference line L1. In automatic steering, the steering of the traveling direction of the tractor 1 (vehicle body 3) is automatically performed so that the vehicle body position measured by the positioning device 40 coincides with the planned traveling line L2.

[0034] Specifically, before performing automatic steering, the tractor 1 (vehicle body 3) is moved to a predetermined position in the field (S1). When the driver operates the steering switch 52 provided on the tractor 1 at the predetermined position (S2), the vehicle body position measured by the positioning device 40 is set to the starting point P10 of the traveling reference line L1 (S3). Also, when the tractor 1 (vehicle body 3) is moved from the starting point P10 of the traveling reference line L1 (S4) and the driver operates the steering switch 52 at a predetermined position (S5), the vehicle body position measured by the positioning device 40 is set to the end point P11 of the traveling reference line L1 (S6). Therefore, the straight line connecting the starting point P10 and the end point P11 is set as the traveling reference line L1.

[0035] After setting the traveling reference line L1 (after S6), for example, when the tractor 1 (vehicle body 3) is moved to a location different from the location where the traveling reference line L1 was set (S7) and the driver operates the steering switch 52 (S8), a planned traveling line L2, which is a straight line parallel to the traveling reference line L1, is set (S9). After setting the planned traveling line L2, automatic steering is started and the traveling direction of the tractor 1 (vehicle body 3) is changed to follow the planned traveling line L2. For example, when the current vehicle body position is on the left side of the planned traveling line L2, the front wheels 7F are steered to the right, and when the current vehicle body position is on the right side of the planned traveling line L2, the front wheels 7F are steered to the left. During automatic steering, the traveling speed (vehicle speed) of the tractor 1 (vehicle body 3) can be changed by the driver manually changing the operation amount of the accelerator member (accelerator pedal, accelerator lever) provided on the tractor 1 or by changing the gear position of the transmission.

[0036] Also, after starting automatic steering, if the driver operates the steering switch 52 at an arbitrary location, automatic steering can be terminated. That is, the end point of the planned traveling line L2 can be set by terminating the automatic steering by operating the steering switch 52. In other words, the length from the start point to the end point of the planned traveling line L2 can be set to be longer or shorter than the traveling reference line L1. In other words, the planned traveling line L2 is not associated with the length of the traveling reference line L1, and with the planned traveling line L2, it is possible to travel while automatically steering a distance longer than the length of the traveling reference line L1.

[0037] As shown in FIG. 1, the steering device 11 has an automatic steering mechanism 37. The automatic steering mechanism 37 is a mechanism for automatically steering the vehicle body 3, and automatically steers the vehicle body 3 based on the position of the vehicle body 3 (vehicle body position) detected by the positioning device 40. The automatic steering mechanism 37 includes a steering motor 38 and a gear mechanism 39. The steering motor 38 is a motor whose rotation direction, rotation speed, rotation angle, etc. can be controlled based on the vehicle body position. The gear mechanism 39 includes a gear provided on the steering shaft 31 and rotating together with the steering shaft 31, and a gear provided on the rotation shaft of the steering motor 38 and rotating together with the rotation shaft. When the rotation shaft of the steering motor 38 rotates, the steering shaft 31 automatically rotates (pivots) via the gear mechanism 39, and the steering direction of the front wheels 7F can be changed so that the vehicle body position coincides with the planned travel line L2.

[0038] As shown in FIG. 1, the tractor 1 is provided with a display device 45. The display device 45 is a device capable of displaying various information regarding the tractor 1, and can display at least the driving information of the tractor 1. The display device 45 is provided in front of the driver's seat 10.

[0039] As shown in FIG. 1, the tractor 1 is provided with a setting switch 51. The setting switch 51 is a switch for switching to a setting mode for performing at least the settings before starting the automatic steering. The setting mode is a mode for performing various settings regarding the automatic steering before starting the automatic steering, for example, a mode for setting the start point and end point of the travel reference line L1.

[0040] The setting switch 51 can be switched to ON or OFF. When it is ON, it outputs a signal indicating that the setting mode is valid, and when it is OFF, it outputs a signal indicating that the setting mode is invalid. Also, when the setting switch 51 is ON, it outputs a signal indicating that the setting mode is valid to the display device 45, and when it is OFF, it outputs a signal indicating that the setting mode is invalid to the display device 45.

[0041] The tractor 1 is equipped with a steering mode switch 52. The steering mode switch 52 is a switch for switching the start or end of automatic steering. Specifically, the steering mode switch 52 can be switched from the neutral position upward, downward, forward, and backward. When it is switched downward from the neutral position in a state where the setting mode is valid, it outputs the start of automatic steering. When it is switched upward from the neutral position in a state where the setting mode is valid, it outputs the end of automatic steering. Also, when the steering mode switch 52 is switched backward from the neutral position in a state where the setting mode is valid, it outputs setting the current vehicle body position to the starting point P10 of the travel reference line L1. When the steering mode switch 52 is switched forward from the neutral position in a state where the setting mode is valid, it outputs setting the current vehicle body position to the end point P11 of the travel reference line L1. That is, the steering mode switch 52 also serves as a reference line setting switch for setting the start position (starting point P10) and the end position (end point P11) of the travel reference line L1. Note that the steering mode switch 52 for switching the start or end of automatic steering and the reference line setting switch may be configured separately.

[0042] The tractor 1 is equipped with a correction switch 53. The correction switch 53 is a switch for correcting the vehicle body position (latitude, longitude) measured by the positioning device 40. That is, the correction switch 53 is a switch for correcting the vehicle body position (referred to as the calculated vehicle body position) calculated from the satellite signal (position of the positioning satellite, transmission time, correction information, etc.) and the measurement information (acceleration, angular velocity) measured by the inertial measurement device 42.

[0043] The correction switch 53 is composed of a push switch that can be pressed or a slide switch that can be slid. Hereinafter, the cases where the correction switch 53 is a push switch and a slide switch respectively will be described.

[0044] When the correction switch 53 is a push switch, the correction amount is set based on the number of operations of the push switch. The correction amount is determined by the formula: correction amount = number of operations × correction amount per operation. For example, as shown in FIG. 3A, each time the push switch is operated, the correction amount increases by several centimeters or several tens of centimeters. The number of operations of the push switch is input to the first control device 60A, and the first control device 60A sets (calculates) the correction amount based on the number of operations.

[0045] Also, when the correction switch 53 is a slide switch, the correction amount is set based on the operation amount (displacement amount) of the slide switch. For example, the correction amount is determined by the formula: correction amount = displacement amount from a predetermined position. For example, as shown in FIG. 3B, each time the displacement amount of the slide switch increases by 5 mm, the correction amount increases by several centimeters or several tens of centimeters. The operation amount (displacement amount) of the slide switch is input to the first control device 60A, and the first control device 60A sets (calculates) the correction amount based on the displacement amount. Note that the above-described method of increasing the correction amount and the rate of increase are not limited to the above-described numerical values.

[0046] Specifically, as shown in FIGS. 4A and 4B, the correction switch 53 includes a first correction unit 53A and a second correction unit 53B. The first correction unit 53A is a part that commands the correction of the vehicle body position corresponding to one side in the width direction of the vehicle body 3, that is, the left side. The second correction unit 53B is a part that commands the correction of the vehicle body position corresponding to the other side in the width direction of the vehicle body 3, that is, the right side.

[0047] As shown in FIG. 4A, when the correction switch 53 is a push switch, the first correction unit 53A and the second correction unit 53B are ON or OFF switches that automatically return every time an operation is performed. The switch constituting the first correction unit 53A and the switch constituting the second correction unit 53B are integrated. Note that the switch constituting the first correction unit 53A and the switch constituting the second correction unit 53B may be arranged apart from each other. As shown in FIG. 3A, every time the first correction unit 53A is pressed, the correction amount (left correction amount) corresponding to the left side of the vehicle body 3 increases. Also, every time the second correction unit 53B is pressed, the correction amount (right correction amount) corresponding to the right side of the vehicle body 3 increases.

[0048] As shown in FIG. 4B, when the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B include a knob portion 55 that moves left or right along the longitudinal direction of the long hole. When the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B are arranged apart from each other in the width direction. As shown in FIG. 3B, when the knob portion 55 is gradually displaced to the left from a predetermined reference position, the left correction amount increases according to the displacement amount. Also, when the knob portion 55 is gradually displaced to the right from a predetermined reference position, the right correction amount increases according to the displacement amount. Note that, as shown in FIG. 4B, in the case of a slide switch, the first correction unit 53A and the second correction unit 53B may be integrally formed, the reference position of the knob portion 55 may be set at the center, the left correction amount may be set when moving to the left from the reference position, and the right correction amount may be set when moving the knob portion 55 to the right from the intermediate position.

[0049] Next, the relationship between the correction amounts (left correction amount, right correction amount) by the correction switch 53, the planned travel line L2, and the behavior (travel locus) of the tractor 1 (vehicle body 3) will be described.

[0050] FIG. 5A shows a state where the calculated vehicle position W1 has shifted to the right while the vehicle is going straight during automatic steering. As shown in FIG. 5A, when the automatic steering is started, if the position of the actual tractor 1 (vehicle body 3) (actual position W2) coincides with the calculated vehicle position W1, and the actual position W2 coincides with the planned travel line L2, the tractor 1 travels along the planned travel line L2. That is, in the section P1 where there is no error in the positioning of the positioning device 40 and the vehicle position (calculated vehicle position W1) detected by the positioning device 40 is the same as the actual position W2, the tractor 1 travels along the planned travel line L 2. Incidentally, when there is no error in the positioning of the positioning device 40 and no correction is performed, the calculated vehicle position W1 and the corrected vehicle position (corrected vehicle position) W3 corrected by the correction amount have the same value. The corrected vehicle position W3 is given by corrected vehicle position W3 = calculated vehicle position W1 - correction amount.

[0051] Here, near position P20, even though the actual position W2 is not deviated from the planned travel line L2, due to various influences, an error occurs in the positioning of the positioning device 40, and the vehicle body position W1 detected by the positioning device 40 is shifted to the right with respect to the planned travel line L2 (actual position W2), and it is assumed that the deviation amount W4 is maintained. Then, the tractor 1 determines that a deviation has occurred between the calculated vehicle body position W1 and the planned travel line L2, and steers the tractor 1 to the left so as to eliminate the deviation amount W4 between the calculated vehicle body position W1 and the planned travel line L2. Then, the actual position W2 of the tractor 1 shifts to the planned travel line L2 by the left steering. After that, it is assumed that the driver notices that the tractor 1 is deviated from the planned travel line L2 and steers the second correction unit 53B at position P21 to increase the right correction amount from zero. A right correction amount is added to the calculated vehicle body position W1, and the corrected vehicle body position (corrected vehicle body position) W3 can be made substantially the same as the actual position W2. That is, by setting the right correction amount by the second correction unit 53B, the vehicle body position of the positioning device 40 can be corrected in the direction of eliminating the deviation amount W4 generated near position P20. As shown in position P21 of FIG. 5A, when the actual position W2 of the tractor 1 is separated from the planned travel line L2 to the left after the correction of the vehicle body position, the tractor 1 is steered to the right, and the actual position W2 of the tractor 1 can be made to coincide with the planned travel line L2.

[0052] FIG. 5B shows a state where the calculated vehicle body position W1 is shifted to the left during straight travel while automatic steering is in progress. As shown in FIG. 5B, in a state where automatic steering has been started, when the actual position W2 and the calculated vehicle body position W1 coincide with each other, and the actual position W2 and the planned travel line L2 coincide with each other, the tractor 1 travels along the planned travel line L2 in the same manner as in FIG. 5A. That is, similar to FIG. 5A, in section P2 where there is no error in the positioning of the positioning device 40, the tractor 1 travels along the planned travel line L2. Also, similar to FIG. 5A, the calculated vehicle body position W1 and the corrected vehicle body position W3 have the same value.

[0053] Here, at position P22, due to various influences, an error occurs in the positioning of the positioning device 40, and the vehicle body position W1 detected by the positioning device 40 is shifted to the left with respect to the actual position W2, and it is assumed that the shift amount W5 is maintained. Then, the tractor 1 steers the tractor 1 to the right so as to eliminate the shift amount W5 between the calculated vehicle body position W1 and the planned travel line L2. After that, it is assumed that the driver notices that the tractor 1 has deviated from the planned travel line L2, and the driver steers the first correction unit 53A at position P23 to increase the left correction amount from zero. Then, a left correction amount is added to the calculated vehicle body position W1, and the corrected vehicle body position (corrected vehicle body position) W3 can be made substantially the same as the actual position W2. That is, by setting the left correction amount by the first correction unit 53A, the vehicle body position of the positioning device 40 can be corrected in the direction of eliminating the shift amount W5 generated in the vicinity of position P22. As shown in position P23 of FIG. 5B, when the actual position W2 of the tractor 1 is separated from the planned travel line L2 to the right after the correction of the vehicle body position, the tractor 1 is steered to the left, and the actual position W2 of the tractor 1 can be made to coincide with the planned travel line L2.

[0054] Next, the setting switch 51 and the correction switch 53 will be described.

[0055] As shown in FIG. 6, the outer periphery of the steering shaft 31 is covered by the steering post 180. The outer periphery of the steering post 180 is covered by the cover 177. The cover 177 is provided in front of the driver's seat 10. The cover 177 includes a panel cover 178 and a column cover 179.

[0056] The panel cover 178 supports the display device 45. A support portion 178e for supporting the display device 45 is provided on the upper plate portion 178a of the panel cover 178. The support portion 178e supports the display device 45 in front of the steering shaft 31 and below the steering wheel 30. Further, the upper plate portion 178a has an attachment surface 178f to which the setting switch 51 and the correction switch 53 are attached. The attachment surface 178f is provided behind the support portion 178e and below the steering wheel 30. The support portion 178e and the attachment surface 178f are continuous, the support portion 178e is located at the front portion of the upper plate portion 178a, and the attachment surface 178f is located at the rear portion of the upper plate portion 178a. The setting switch 51 and the correction switch 53 are attached to the attachment surface 178f. Thereby, the setting switch 51 and the correction switch 53 are arranged around the steering shaft 31.

[0057] A shuttle lever 181 protrudes from the left plate portion 178b of the panel cover 178. The shuttle lever 181 is a member that performs an operation of switching the traveling direction of the vehicle body 3. More specifically, by operating (swinging) the shuttle lever 181 forward, the forward-reverse switching unit 13 outputs forward power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the forward direction. Further, by operating (swinging) the shuttle lever 181 backward, the forward-reverse switching unit 13 outputs reverse power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the reverse direction. When the shuttle lever 181 is in the neutral position, no power is output to the traveling device 7.

[0058] The column cover 179 is disposed below the steering wheel 30 and covers the periphery of the upper portion of the steering shaft 31. The column cover 179 is formed in a substantially rectangular tube shape and protrudes upward from the attachment surface 178f of the panel cover 178. That is, the attachment surface 178f is provided around the column cover 179. Therefore, the setting switch 51 and the correction switch 53 attached to the attachment surface 178f are arranged around the column cover 179.

[0059] Next, the arrangements of the setting switch 51, the steering changeover switch 52, and the correction switch 53 will be described in detail. As shown in FIG. 6, the setting switch 51, the steering changeover switch 52, and the correction switch 53 are arranged around the steering shaft 31.

[0060] The setting switch 51 is arranged on one side (left side) of the steering shaft 31. The steering changeover switch 52 is arranged on one side (left side) of the steering shaft 31. In the case of this embodiment, the steering changeover switch 52 is composed of a swingable lever. The steering changeover switch 52 is swingable with the base end portion provided on the steering shaft 31 side as a fulcrum. The base end portion of the steering changeover switch 52 is provided inside the column cover 179. The steering changeover switch 52 protrudes to one side (left side) of the column cover 179.

[0061] The correction switch 53 is arranged on the other side (right side) of the steering shaft 31. More specifically, the correction switch 53 is arranged on the right side and the rear side (diagonally right rear) of the steering shaft 31. In terms of the positional relationship with the column cover 179, the correction switch 53 is arranged on the right side and the rear side (diagonally right rear) of the column cover 179. In terms of the positional relationship with the mounting surface 178f of the panel cover 178, the correction switch 53 is arranged at the right rear part of the mounting surface 178f. By arranging the correction switch 53 at the rear part of the inclined mounting surface 178f, the distance between the correction switch 53 and the steering wheel 30 can be ensured to be long. Thereby, the unintentional operation of the correction switch 53 and the steering of the steering wheel 30 can be more reliably prevented.

[0062] As described above, the setting switch 51, the steering changeover switch 52, and the correction switch 53 are arranged around the steering shaft 31. In other words, the setting switch 51, the steering changeover switch 52, and the correction switch 53 are concentrated and present around the steering shaft 31. Therefore, the driver can clearly grasp the positions of the respective switches at a glance. In addition, the driver can operate each switch without changing the posture while remaining seated in the driver's seat 10. Therefore, the operability is improved, and malfunction can be prevented. Also, the harness (wiring) routed from each switch can be shortened.

[0063] Incidentally, regarding the arrangement of the switches described above, the left and right may be swapped and arranged. That is, one side may be the left side and the other side may be the right side, or one side may be the right side and the other side may be the left side. Specifically, for example, the setting switch 51 and the steering changeover switch 52 may be arranged on the right side of the steering shaft 31, and the correction switch 53 may be arranged on the left side of the steering shaft 31.

[0064] As shown in FIG. 1, the tractor 1 includes a plurality of control devices 60. The plurality of control devices 60 are devices that perform control of the traveling system, control of the working system, calculation of the vehicle body position, etc. in the tractor 1. The plurality of control devices 60 are the first control device 60A, the second control device 60B, and the third control device 60C.

[0065] The first control device 60A receives the satellite signal (received information) received by the receiving device 41 and the measurement information (acceleration, angular velocity, etc.) measured by the inertial measurement device 42, and determines the vehicle body position based on the received information and the measurement information. For example, when the correction amount by the correction switch 53 is zero, that is, when the correction of the vehicle body position by the correction switch 53 is not commanded, the first control device 60A does not correct the calculated vehicle body position W1 calculated from the received information and the measurement information, and determines the calculated vehicle body position W1 as the vehicle body position to be used during automatic steering. On the other hand, when the correction of the vehicle body position by the correction switch 53 is commanded, the first control device 60A sets the correction amount of the vehicle body position based on either the number of operations of the correction switch 53 or the operation amount (displacement amount) of the correction switch 53, and determines the corrected vehicle body position W3 obtained by correcting the calculated vehicle body position W1 by the correction amount as the vehicle body position to be used during automatic steering.

[0066] The first control device 60A sets a control signal based on the vehicle body position (calculated vehicle body position W1, corrected vehicle body position W3) and the planned travel line L2, and outputs the control signal to the second control device 60B. The second control device 60B has an automatic steering control unit 200. The automatic steering control unit 200 is composed of an electric / electronic circuit provided in the second control device 60B, a program stored in a CPU, etc. The automatic steering control unit 200 controls the steering motor 38 of the automatic steering mechanism 37 so that the vehicle body 3 travels along the planned travel line L2 based on the control signal output from the first control device 60A.

[0067] As shown in FIG. 7, when the deviation between the vehicle body position and the planned travel line L2 is less than the threshold value, the automatic steering control unit 200 maintains the rotation angle of the rotation shaft of the steering motor 38. When the deviation between the vehicle body position and the planned travel line L2 is greater than or equal to the threshold value and the tractor 1 is located on the left side of the planned travel line L2, the automatic steering control unit 200 rotates the rotation shaft of the steering motor 38 so that the steering direction of the tractor 1 becomes the right direction. When the deviation between the vehicle body position and the planned travel line L2 is greater than or equal to the threshold value and the tractor 1 is located on the right side of the planned travel line L2, the automatic steering control unit 200 rotates the rotation shaft of the steering motor 38 so that the steering direction of the tractor 1 becomes the left direction. In the above-described embodiment, the steering angle of the steering device 11 is changed based on the deviation between the vehicle body position and the planned travel line L2. However, when the azimuth of the planned travel line L2 and the azimuth (vehicle body azimuth) F1 of the traveling direction (travel direction) of the tractor 1 (vehicle body 3) are different, that is, when the angle θg of the vehicle body azimuth F1 with respect to the planned travel line L2 is greater than or equal to the threshold value, the automatic steering control unit 200 may set the steering angle so that the angle θg becomes zero (the vehicle body azimuth F1 coincides with the azimuth of the planned travel line L2). Further, the automatic steering control unit 200 may set the final steering angle in automatic steering based on the steering angle obtained based on the deviation (position deviation) and the steering angle obtained based on the azimuth (azimuth deviation). The setting of the steering angle in the automatic steering in the above-described embodiment is an example and is not limited. The steering angle may be set so that the angle θg becomes zero (the vehicle body azimuth F1 coincides with the azimuth of the planned travel line L2). Further, the automatic steering control unit 200 may set the final steering angle in automatic steering based on the steering angle obtained based on the deviation (position deviation) and the steering angle obtained based on the azimuth (azimuth deviation). The setting of the steering angle in the automatic steering in the above-described embodiment is an example and is not limited.

[0068] As described above, the control device 60 can automatically steer the tractor 1 (vehicle body 3).

[0069] The third control device 60C performs various controls related to the tractor 1. The third control device 60C can perform manual lifting control, auto-up control, double-speed control, etc. In the manual lifting control, it is the control to lift or lower the lifting device 8 based on the operation of the lift switch 101 connected to the third control device 60C. Specifically, the lift switch 101 is provided around the driver's seat 10 and is a three-position changeover switch. When the lift switch 101 is switched from the neutral position to one side, an upward signal for raising the lifting device 8 (lift arm 8a) is input to the third control device 60C. Also, when the lift switch 101 is switched from the neutral position to the other side, a downward signal for lowering the lifting device 8 (lift arm 8a) is input to the third control device 60. The third control device 60C outputs a control signal to the control valve 29 when it acquires the upward signal to raise the lifting device 8, and outputs a control signal to the control valve 29 when it acquires the downward signal to lower the lifting device 8. That is, the third control device 60 can perform manual lifting control to raise or lower the lifting device 8 according to the manual operation of the lift switch 101.

[0070] Also, in the auto-up control, when the tractor 1 (vehicle body 3) reverses, it is the control to raise the working device 2 by automatically operating the lifting device 8. Specifically, a reverse detection device 102 for detecting reverse is connected to a control device 60 such as the control device 60C. The reverse detection device 102 is a sensor for detecting the rotation of the front axle 21F, a sensor for detecting the rotation of the rear axle 21R, a sensor for detecting the switching position of the shuttle lever 181, etc. That is, the reverse detection device 102 detects the reverse of the tractor 1 (vehicle body 3) when the rotation directions of the front axle 21F and the rear axle 21R are rotation directions corresponding to reverse, or when the switching position of the shuttle lever 181 is on the reverse side. When the third control device 60C detects the reverse of the tractor 1 (vehicle body 3) by the reverse detection device 102, it performs auto-up control to automatically raise the lifting device 8 by outputting a control signal to the control valve 29. Note that the above-described reverse detection device 102 is an example and is not limited.

[0071] Also, in the double-speed control, when the steering angle of the steering device 11 is equal to or greater than a predetermined value, for example, the steering angle corresponding to turning, the connection of the first clutch 17 and the second clutch 18 is automatically changed to make the rotational speed of the front wheels 7F faster than the rotational speed of the rear wheels. Specifically, a steering angle detection device 205 for detecting the steering angle of the steering device 11 is connected to a control device 60 such as the control device 60C. When the steering angle detected by the steering angle detection device 205 is equal to or greater than the steering angle corresponding to turning, the control device 60C outputs a control signal to the first operation valve 25 and the second operation valve 26 to connect the first clutch 17 and disconnect the second clutch 18, thereby making the rotational speed of the front wheels 7F faster than the rotational speed of the rear wheels.

[0072] As described above, the control device 60C can perform controls related to the tractor 1, such as manual lifting control, auto-up control, and double-speed control.

[0073] Now, as described above, automatic steering can be performed by switching the steering changeover switch 52. However, the tractor 1 changes the control related to automatic steering according to the seating situation of the operator (driver) in the driver's seat 10.

[0074] A seating detection device 110 is connected to a control device 60 such as the control device 60B. The seating detection device 110 is a device capable of detecting that the driver is seated in the driver's seat 10. The seating detection device 110 is, for example, a load sensor provided in the seat portion 10a or the backrest portion 10b of the driver's seat 10. When the seating detection device 110 is a load sensor provided in the seat portion 10a, if the load applied to the seat portion 10a is equal to or greater than a predetermined value (threshold value or more), the control device 60 determines that the driver is seated in the driver's seat 10. On the other hand, if the load applied to the seat portion 10a is less than the threshold value, the control device 60 determines that the driver is not seated in the driver's seat 10.

[0075] Alternatively, even when the seating detection device 110 is a load sensor provided in the backrest portion 10b, if the load applied to the backrest portion 10b is equal to or greater than a predetermined value (threshold value or more), the control device 60B determines that the driver is seated in the driver's seat 10. On the other hand, if the load applied to the backrest portion 10b is less than the threshold value, the control device 60B determines that the driver is not seated in the driver's seat 10. In the above-described embodiment, the seating detection device 110 is configured by a load sensor, but the present invention is not limited thereto, and any device can be used as long as it can detect the seating on the driver's seat 10.

[0076] FIG. 9 is an operation flow showing the relationship between the seating state and the automatic steering.

[0077] In a situation where the start position (starting point P10) and the end position (ending point P11) are not set, if the setting mode is valid by the setting switch 51 (S21, Yes), the second control device 60B monitors the detection status of the seating detection device 110. When the seating detection device 110 detects seating (S22, Yes) and an operation of the starting point (operation from the neutral position to the rear) is performed by the steering switch 52 (S23, Yes), the current vehicle body position is set to the starting point P10 of the travel reference line L1 (S24: starting point registration). Note that the second control device 60B does not set the starting point P10 even if the operation of the starting point is performed while the seating detection device 110 does not detect seating. At the time of starting point registration, when the driver is not seated in the driver's seat 10, the display device 45 performs a display prompting seating.

[0078] Also, when the seating detection device 110 detects seating (S22, Yes) and an operation of the end point (operation from the neutral position to the front) is performed by the steering switch 52 (S25, Yes), the current vehicle body position is set to the end point P11 of the travel reference line L1 (S26: end point registration). Note that the second control device 60B does not set the end point P11 even if the operation of the end point is performed while the seating detection device 110 does not detect seating. Also, at the time of end point registration, when the driver is not seated in the driver's seat 10, the display device 45 performs a display prompting seating.

[0079] Therefore, when the driver is seated in the driver's seat 10, the starting point P10 and the ending point 11 of the driving reference line L1 can be set.

[0080] After setting the starting point P10 and the ending point P11 of the driving reference line L1, when the switching of the start of automatic steering by the steering switch 52 is performed (S27, Yes), the second control device 60B determines whether the seating detection device 110 has detected seating. If seating is detected (S28, Yes), permission for automatic steering is given (S29). When permission for automatic steering is given, the second control device 60B sets a planned travel line L2 parallel to the driving reference line L1 and executes automatic steering as described above (S30).

[0081] On the other hand, when the seating detection device 110 has not detected seating (S28, No), the second control device 60B does not give permission for automatic steering, that is, even if the switching of the start of automatic steering by the steering switch 52 is performed, automatic steering is not permitted (S31). In the case where automatic steering is not permitted, the display device 45 displays a prompt to be seated.

[0082] The second control device 60B monitors the detection status of the seating detection device 110 even during automatic steering. When, during automatic steering, the seating detection device 110 changes from a seating detection state in which seating is detected to a departure detection state in which seating is not detected (S33, Yes), the second control device 60B stops (ends) automatic steering (S34: automatic steering stop). In the case of automatic steering stop, the second control device 60B switches from automatic steering to manual steering, for example, by stopping the output of a control signal to the steering motor 38.

[0083] In addition, when the second control device 60B changes from the seated detection state to the vacated detection state, as shown in FIG. 10, if the elapsed time in the vacated detection state (the elapsed time since the seated detection state ended) T1 exceeds a predetermined threshold value (determination time), the automatic steering may be stopped. In this case, when the vacated state is entered, it is preferable to notify the driver that the driver has vacated the driver's seat 10 by the notification device 80. Specifically, the notification device 80 is connected to a control device 60 such as the second control device 60B. The notification device 80 is a speaker, a lamp, etc., and is provided near the driver's seat 10. As shown in FIG. 10, the notification device 80 starts (turns on) the notification at the time point P25 when the vacated state is entered, and notifies the driver that the driver has vacated the driver's seat 10 by outputting voice, warning sound, lighting or flashing of the lamp, etc. from the speaker. Note that as the elapsed time in the vacated state becomes longer, the notification device 80 increases the output time of the voice and the warning sound, shortens the flashing speed of the lamp, increases the brightness of the lighting of the lamp, or increases the notification intensity.

[0084] According to the above, the second control device 60B permits automatic steering when the seating detection device 110 detects seating and the start of automatic steering is switched by the steering changeover switch 52, and does not permit automatic steering when the seating detection device 110 does not detect seating and the start of automatic steering is switched by the steering changeover switch 52. Therefore, it is possible to cause the automatic steering to start by operating the steering changeover switch 52 in a state where the driver is surely seated on the driver's seat 10.

[0085] When the automatic steering is being performed, the second control device 60B stops (ends) the automatic steering when the seating detection device 110 changes from the seated detection state in which the seating is detected to the vacated detection state in which the seating is not detected. Therefore, it is possible to stop the automatic steering at the time when the driver leaves the driver's seat 10 during the automatic steering.

[0086] Now, in the above-described embodiment, when the second control device 60B changes from the seated detection state to the leaving-seat detection state, it stops the automatic steering. In addition to this, the manual steering may also be stopped. FIG. 11 shows an operation flow in which the manual steering is also stopped. In FIG. 11, S21 to S33 are the same as those in FIG. 9.

[0087] As shown in FIG. 11, when the second control device 60B changes from the seated detection state to the leaving-seat detection state (S33, Yes), it stops the drive of the prime mover 4 (S35: Prime mover stop). That is, the second control device 60B stops the prime mover 4 by turning off the ignition or by outputting a stop signal for the drive of the prime mover 4 to the control device that controls the drive of the prime mover 4. When the prime mover 4 stops, the power from the prime mover 4 is no longer transmitted to the traveling device 7, so that the tractor 1 (the vehicle body 3) can be stopped.

[0088] The work vehicle 1 includes a driver's seat 10, a steering wheel 30, a vehicle body 3 that can travel by either manual steering by the steering wheel 30 or automatic steering of the steering wheel 30 based on a traveling reference line, a steering changeover switch 52 that switches between starting and ending the automatic steering, a seating detection device 110 that detects that the driver is seated on the driver's seat 10, and when the seating detection device 110 detects seating and the automatic steering start is switched by the steering changeover switch 52, permits the automatic steering, and when the seating detection device 110 does not detect seating and the automatic steering start is switched by the steering changeover switch 52, does not permit the automatic steering and a control device 60 (the second control device 60B). According to this, when the driver operates the steering changeover switch 52 to switch to the start of automatic steering in a situation where the driver is surely seated on the driver's seat 10, the start of automatic steering can be performed. That is, it becomes possible to appropriately perform the automatic steering according to the state of the driver.

[0089] When the control device 60 (second control device 60B) detects a change from the seating detection state in which the seating detection device 110 detects seating to the departure detection state in which seating is not detected during automatic steering, the automatic steering is stopped. According to this, during automatic steering, when the driver leaves the driver's seat 10, it is possible to automatically switch from automatic steering to manual steering.

[0090] The work vehicle 1 includes a prime mover 4 provided on the vehicle body 3 and a traveling device 7 that causes the vehicle body 3 to travel by the power of the prime mover 4. When the control device 60 (second control device 60B) detects a change from the seating detection state to the departure detection state, the drive of the prime mover 4 is stopped. According to this, when the driver leaves the driver's seat 10, it is possible to stop both automatic steering and manual steering, and the work vehicle 1 can also be stopped.

[0091] The work vehicle 1 includes a positioning device 40 capable of detecting the position of the vehicle body 3 and a reference line setting switch that sets the position of the vehicle body 3 detected by the positioning device 40 at the start position and the end position of the travel reference line L1. According to this, the start position and the end position of the travel reference line L1 can be easily set by operating the reference line setting switch.

[0092] The work vehicle 1 includes a correction switch 53 that commands correction of the position of the vehicle body 3 detected by the positioning device 40, a corrected vehicle body position (corrected position) W3 that is the position of the vehicle body 3 corrected by operating the correction switch 53, and a steering device 11 that steers the vehicle body 3 based on a planned travel line L2 set based on the travel reference line L1. According to this, while correcting the position of the vehicle body 3 by operating the correction switch 53, the vehicle body 3 can be made to travel along the planned travel line L2 by the steering device 11.

[0093] Now, the third control device 60C of the tractor 1 can limit the operation of the operating device provided on the tractor 1 when the automatic steering is being performed under the control of the second control device 60B. In other words, the third control device 60C restricts controls such as auto-up control and double-speed control when automatic steering is performed under the control of the second control device 60B.

[0094] The third control device 60C operates the operating device when the operating conditions predetermined for the operation of the operating device are satisfied in a state where automatic steering is not being performed (manual steering state), while it does not operate the operating device when the operating conditions are satisfied in a state where automatic steering is being performed.

[0095] Hereinafter, the restriction of the operation of the operating device will be described in detail.

[0096] The operating device is, for example, a double-speed device or an auto-up device. The double-speed device is a device that makes the rotational speed of the front wheels 7F faster than the rotational speed of the rear wheels 7R on the condition that the steering angle of the steering wheel 30 is equal to or greater than a predetermined value (steering angle corresponding to turning) by the double-speed control in the third control device 60C. In this embodiment, the double-speed device includes a first clutch 17, a second clutch 18, a first operation valve 25, and a second operation valve 26.

[0097] The auto-up device is a device that raises the lifting device 8 on the condition that the vehicle body 3 has moved backward. In this embodiment, the auto-up device includes a lift cylinder 8e and a control valve 29.

[0098] FIG. 12A is an operation flow showing the relationship between the double-speed device and automatic steering when the operating device is the double-speed device. Note that the tractor 1 is provided with a changeover switch for switching the double-speed control between effective and ineffective, and the description of the operation flow of FIG. 12A will be advanced on the premise that the double-speed control is effective by the changeover switch.

[0099] After setting the start position (starting point P10) and the end position (ending point P11) of the traveling reference line L1, in a state where automatic steering is not being performed, that is, in a state where the start of automatic steering is not commanded by the steering changeover switch 52 (S40, No), the second control device 60B outputs stop information indicating that automatic steering has stopped to the third control device 60C (S41). On the other hand, when the third control device 60C acquires the stop information (S42), it monitors the steering angle detected by the steering angle detection device 205 (S43). When the steering angle detected by the steering angle detection device 205 is equal to or greater than a predetermined value (S44, Yes), the third control device 60C outputs a control signal to the first operation valve 25 and the second operation valve 26 to make the rotational speed of the front wheels 7F faster than the rotational speed of the rear wheels 7R (S45).

[0100] Also, in a state where the start of automatic steering is commanded by the steering changeover switch 52 (S40, Yes), the second control device 60B outputs operation information indicating that automatic steering is operating to the third control device 60C (S46). When the third control device 60C acquires the operation information (S47), it sets the double-speed control from effective to ineffective (S48), and does not perform double-speed control even if the steering angle detected by the steering angle detection device 205 is equal to or greater than a predetermined value. Further, the third control device 60C waits until it acquires stop information indicating that automatic steering has stopped (ended) from the second control device 60B (S49).

[0101] Next, when it becomes a state where the end of automatic steering is commanded by the steering changeover switch 52 (S50), the second control device 60B outputs stop information to the third control device 60C (S51). When the third control device 60C acquires the stop information (S49, Yes), it switches the double-speed control from ineffective to effective (S52), returns to S43, and executes the double-speed control.

[0102] That is, the third control device 60C starts the operation of the double-speed device when the operating conditions are satisfied in a state where automatic steering is not being performed, and does not start the operation of the double-speed device when automatic steering is being performed and the operating conditions are satisfied.

[0103] Figure 12B is an operation flow showing the relationship between the auto-up device and the automatic steering when the operating device is the auto-up device. Note that the tractor 1 is provided with a changeover switch for switching the auto-up control between effective and ineffective. Assuming that the auto-up control is effective by the changeover switch, the description of the operation flow in Figure 12B will be advanced.

[0104] After setting the start position (starting point P10) and the end position (ending point P11) of the traveling reference line L1, in a state where the automatic steering is not performed, that is, in a state where the start of the automatic steering is not commanded by the steering changeover switch 52 (S60, No), the second control device 60B outputs stop information to the third control device 60C (S61). On the other hand, when the third control device 60C acquires the stop information (S62), it determines whether the vehicle body 3 is moving backward based on the detection information by the backward movement detection device 102. If the vehicle body 3 is moving backward (S63, Yes), it outputs a control signal to the control valve 29 to automatically raise and lower the lifting device 8 (S64).

[0105] Also, in a state where the start of the automatic steering is commanded by the steering changeover switch 52 (S60, Yes), the second control device 60B outputs operation information to the third control device 60C (S65). When the third control device 60C acquires the operation information (S66), it sets the auto-up control from effective to ineffective (S67). Even when the backward movement detection device 102 detects backward movement, the au to-up control is not performed. Also, the third control device 60C waits until it acquires the stop information transmitted from the second control device 60B (S68).

[0106] Next, when it becomes a state where the end of the automatic steering is commanded by the steering changeover switch 52 (S69), the second control device 60B outputs stop information to the third control device 60C (S70). When the third control device 60C acquires the stop information (S68, Yes), it switches the double-speed control from ineffective to effective (S71), returns to S63, and executes the auto-up control.

[0107] That is, when the operating conditions are satisfied in a state where automatic steering is not being performed, the third control device 60C starts the operation of the auto-up device, and when automatic steering is being performed and the operating conditions are satisfied, the third control device 60C does not start the operation of the auto-up device.

[0108] The work vehicle 1 includes a steering wheel 30, a vehicle body 3 that can travel by either manual steering with the steering wheel 30 or automatic steering of the steering wheel 30 based on a traveling reference line L1, an operating device provided on the vehicle body 3, and a control device 60 (third control device 60C) that restricts the operation of the operating device when automatic steering is being performed. According to this, when automatic steering is performed, the operation of the operating device can be restricted, so the influence of the operation of the operating device on automatic steering can be reduced, and automatic steering can be performed smoothly.

[0109] The control device 60 (third control device 60C) operates the operating device when the operating conditions predetermined for the operation of the operating device are satisfied in a state where automatic steering is not being performed, and does not operate the operating device when the operating conditions are satisfied in a state where automatic steering is being performed. According to this, when the operating conditions are satisfied, automatic steering can be given priority over the operation of the operating device.

[0110] The work vehicle 1 includes a traveling device including front wheels and rear wheels. The operating device is a speed doubling device that makes the rotational speed of the front wheels faster than the rotational speed of the rear wheels with the steering angle of the steering wheel 30 being equal to or greater than a predetermined value as the operating condition. The control device 60 (third control device 60C) starts the operation of the speed doubling device when the operating conditions are satisfied in a state where automatic steering is not being performed, and does not start the operation of the speed doubling device when automatic steering is being performed and the operating conditions are satisfied. According to this, when performing automatic steering, the steering angle can be made equal to or greater than the predetermined value at which the speed doubling device operates, and even when there is a speed doubling device, more accurate automatic steering can be performed.

[0111] The work vehicle 1 includes a working device provided at the rear of the vehicle body 3 and a lifting device that raises and lowers the working device. The operating device is an auto-up device that raises the lifting device on the condition that the vehicle body 3 has reversed. The control device 60 (third control device 60C) starts the operation of the auto-up device when the operating condition is satisfied in a state where automatic steering is not being performed, and does not start the operation of the auto-up device when automatic steering is being performed and the operating condition is satisfied. According to this, it is possible to perform automatic steering not only when the vehicle body 3 moves forward but also when the vehicle body 3 moves backward.

[0112] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Signs

[0113] 1 Work vehicle 3 Vehicle body 4 Prime mover 10 Driver's seat 11 Steering device 30 Steering wheel 40 Positioning device 52 Steering changeover switch 53 Correction switch 60 Control device 60B Second control device 60C Third control device 101 Lifting switch 102 Reverse detection device 110 Occupancy detection device 205 Steering angle detection device L1 Travel reference line L2 Planned travel line

Claims

1. The driver's seat and A steering handle, A vehicle body capable of traveling by either manual steering using the steering wheel or automatic steering of the steering wheel that steers the traveling direction so as to coincide with a planned traveling line that is parallel to a traveling reference line; A prime mover provided on the vehicle body; a traveling device that causes the vehicle body to travel using the power of the prime mover; A positioning device capable of detecting the position of the vehicle body; a reference line setting switch for setting the vehicle body position detected by the positioning device to the start position and end position of the travel reference line; a steering changeover switch for changing over between the automatic steering and the manual steering; A seating detection device for detecting whether a driver is seated; a control device that permits the automatic steering when the seating detection device detects the seating and when a switching operation from manual steering to automatic steering is performed by the steering changeover switch; An alarm device that notifies the driver that the driver is away from the driver's seat; Equipped with The control device of the work vehicle stops the automatic steering when the automatic steering is being performed and the seating detection device does not detect the seating.

2. The control device of the work vehicle described in claim 1, wherein when the automatic steering is being performed, if the seating detection device changes from a seating detection state in which the seating is detected to an absence detection state in which the seating is not detected, issues the notification through the alarm device, and if the progression of the absence detection state exceeds a predetermined judgment threshold, stops the movement of the vehicle body.

3. The work vehicle according to claim 1 or 2, wherein the notification device increases a notification intensity as the time period during which the absence from the seat is detected increases.

Images