Work vehicles

Abstract

To provide a work vehicle which can reduce a work load of attaching a work machine to a travel vehicle body even when a worker is alone.SOLUTION: An agricultural work vehicle comprises: a travel vehicle body; a work machine which is detachably attached to the travel vehicle body; a vehicle body positioning device which measures the position of the travel vehicle body; a work machine positioning device which measures the position of the work machine and acquires position information; a control device which makes the travel vehicle body automatically travel; and first input operation means which is used by a worker to input an instruction signal of bringing the travel vehicle body close to the position of the work machine to the control device. The control device records the current position information of the work machine as the position information indicating the detachment position of the work machine under such a condition that the position of the travel vehicle body measured by the vehicle body positioning device and the position of the work machine measured by the work machine positioning device are apart from each other by a preset distance, and makes the travel vehicle body automatically travel with the detachment position as the target when the instruction signal is input by using the first input operation means.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a work vehicle equipped with a work implement for performing agricultural work. [Background technology]

[0002] Conventionally, work vehicles have been known in which a work implement for performing agricultural work is attached to a traveling body that travels through a field. In this specification, the work vehicle is also referred to simply as a "vehicle," and the traveling body is also referred to simply as a "vehicle body."

[0003] For example, Patent Document 1 discloses a work vehicle configured so that a work machine can be attached via a hitch to a three-point link mechanism provided at the rear of the traveling vehicle body.

[0004] To attach a work implement to a traveling vehicle body, the two must be aligned with each other. Generally, work implements are very heavy, making it difficult for an operator to move the work implement to the appropriate position relative to the traveling vehicle body by himself. For this reason, when there is only one operator performing the attachment work, the operator must drive the traveling vehicle body, move the traveling vehicle body to the appropriate position relative to the work implement, and then attach the work implement to the traveling vehicle body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2016-029924 Summary of the Invention [Problem to be solved by the invention]

[0006] However, precise alignment is required when attaching the work equipment, and therefore, if the worker is not skilled in driving the traveling vehicle, the attachment work can be a significant burden for the worker, as the worker may have to turn the vehicle back and forth multiple times to move the traveling vehicle to the appropriate position relative to the work equipment.

[0007] In light of this situation, an object of the present invention is to provide a work vehicle that can reduce the workload of a single worker when attaching a work implement to a traveling vehicle body. [Means for solving the problem]

[0008] The object of the present invention is to An agricultural work vehicle, a traveling vehicle body having a transmission for changing the vehicle speed and a steering mechanism for changing the traveling direction of the vehicle body; a work machine removably attached to the traveling vehicle body; a vehicle positioning device for measuring the position of the traveling vehicle; a work machine positioning device that measures the position of the work machine and acquires position information; a control device that controls the transmission and the steering mechanism to automatically drive the traveling vehicle body; a first input operation means used by an operator to input to the control device an instruction signal for moving the traveling vehicle body closer to the position of the work machine, The control device records the current position information of the work machine as position information indicating the removal position of the work machine, on the condition that the position of the traveling vehicle body measured by the vehicle body positioning device and the position of the work machine measured by the work machine positioning device are separated by more than a preset distance, and then This is achieved by a work vehicle characterized in that when an instruction signal is input using the first input operation means, the position information indicating the removal position is referenced and the traveling body is automatically driven to target the removal position.

[0009] According to the present invention, when an instruction signal is input to the control device using the first input operation means, the control device is configured to automatically drive the traveling vehicle body toward the removal position, so that the traveling vehicle body can be easily brought close to the work machine and the workload of attaching the work machine to the traveling vehicle body can be reduced.

[0010] Furthermore, according to the present invention, the control device is configured to record the current position information of the work machine as position information indicating the removal position of the work machine, provided that the traveling vehicle body and the work machine are further away from each other than a predetermined set distance. Therefore, the worker does not need to record the removal position of the work machine by performing some kind of operation, thereby reducing the burden on the worker.

[0011] In a preferred embodiment of the present invention, An orientation acquisition means for acquiring an orientation in which the traveling vehicle body is facing; a traveling direction acquisition means for acquiring a traveling direction of the traveling vehicle body, After recording the position information of the removal position, the control device records the orientation of the traveling vehicle body acquired by the orientation acquisition means and the traveling direction acquired by the traveling direction acquisition means, on the condition that the position of the traveling vehicle body measured by the vehicle body positioning device has moved away from the position of the work machine measured by the work machine positioning device, and then The control device is configured to automatically drive the vehicle body toward the removal position, pass the removal position, and then automatically drive the vehicle body to a driving reference line set parallel to the direction of travel, and then automatically drive the vehicle body in the opposite direction to the direction of travel while facing in approximately the same direction as the recorded direction.

[0012] According to this preferred embodiment of the present invention, the orientation and direction of travel of the vehicle body when it leaves the work machine are recorded, and when the vehicle body is automatically driven toward the removal position, the vehicle body is configured to travel in the opposite direction to the recorded direction of travel while facing in approximately the same orientation as the recorded orientation, so that the vehicle body can be moved to the left or right position of the vehicle body when it leaves the position of the work machine.

[0013] Furthermore, according to this preferred embodiment of the present invention, the traveling vehicle body is automatically driven in the direction opposite to the forward direction on the condition that the traveling vehicle body has moved away from the position of the work machine, thereby reducing the risk of the traveling vehicle body coming into contact with some kind of obstacle.

[0014] In a further preferred embodiment of the present invention, When the traveling vehicle body reaches a point that is a predetermined distance away from the removal position, the control device is configured to stop the traveling vehicle body.

[0015] According to this preferred embodiment of the present invention, the vehicle stops moving when it reaches a point a predetermined distance away from the removal position of the work machine, allowing the worker to check the distance between the traveling vehicle body and the work machine, thereby improving safety.

[0016] In a further preferred embodiment of the present invention, a second input operation means used by an operator to input to the control device an instruction signal for causing the traveling vehicle body to further automatically travel in the opposite direction to the traveling direction after the traveling vehicle body has stopped traveling, the control device is configured to record the vehicle speed when the traveling vehicle body is automatically driven to a point separated by the predetermined distance, When an instruction signal is input using the second input operation means, the control device causes the traveling vehicle body to automatically travel at a speed lower than the speed at which the traveling vehicle body automatically travels to a point that is the predetermined distance away.

[0017] According to this preferred embodiment of the present invention, after the traveling vehicle body has stopped traveling, when it approaches further to the removal position of the work implement, it is configured to automatically travel at a speed lower than the vehicle speed before it stopped traveling, so that the worker can monitor the traveling of the traveling vehicle body with peace of mind. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a work vehicle that can reduce the workload of an operator when attaching a work implement to a traveling vehicle body, even when the operator is working alone. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic left side view of a work vehicle according to a preferred embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view of the work vehicle shown in FIG. [Figure 3] FIG. 3 is a schematic plan view showing the vicinity of the lower part of the steering mechanism. [Figure 4] FIG. 4 is a schematic perspective view showing a part of an operating unit arranged near the steering wheel. [Figure 5] FIG. 5 is a control block diagram of the work vehicle shown in FIG. [Figure 6] FIG. 6 is a schematic left side view of the vicinity of the attachment hitch, showing a state in which the working implement has been removed from the traveling vehicle body. [Figure 7] FIG. 7 is an exploded perspective view of the rear portion of the work vehicle. [Figure 8] FIG. 8 is a flowchart relating to the detection of removal of the work implement by the removal detection unit while the control device is operating. [Figure 9] FIG. 9 is a schematic plan view showing the traveling vehicle body moving away from the work implement after the work implement has been removed. [Figure 10] FIG. 10 is a diagram showing a driving instruction screen displayed on the operation terminal. [Figure 11] FIG. 11 is a flowchart relating to the control of moving the traveling vehicle body toward the removal position of the work implement. [Figure 12] FIG. 12 is a schematic plan view showing the positional relationship when the traveling vehicle body is brought close to the detachment position of the work implement. [Figure 13] FIG. 13 is a schematic plan view showing the positional relationship between the vehicle body and the working implement when the traveling vehicle body is stopped at the midpoint. [Figure 14] FIG. 14 is a schematic left side view showing the positional relationship between the vehicle body and the working machine when the traveling vehicle body is stopped at the midpoint. [Figure 15] FIG. 15 is a diagram showing a restart instruction screen displayed on the operation terminal after the travel stop control is performed. [Figure 16] FIG. 16 is a schematic left side view showing how a work machine is attached to the traveling vehicle body that is in the attachment position. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic left side view of a work vehicle 1 according to a preferred embodiment of the present invention, and FIG. 2 is a schematic plan view of the work vehicle 1 shown in FIG.

[0021] In this specification, unless otherwise specified, the forward side in the traveling direction of the work vehicle 1 is referred to as the "front" and the opposite side as the "rear", and the left side as viewed from the forward side in the traveling direction of the work vehicle 1 is referred to as the "left" and the opposite side as the "right". The forward side in the traveling direction of the work vehicle 1 is the horizontal direction from the driver's seat 18 toward the steering wheel 15a.

[0022] The work vehicle 1 comprises a running body 2 having running wheels 13, 14, a work implement 3 attached to the rear of the running body 2 via a three-point linkage mechanism 7 and an attachment hitch 53 and used for agricultural work, a control device 5 for controlling the work vehicle 1, a vehicle body positioning device 11 attached to the running body 2, a work implement positioning device 12 attached to the work implement 3, and an operation terminal 60 (see Figure 10) capable of sending and receiving various information via wireless communication with the control device 5.

[0023] The traveling vehicle body 2 is equipped with a pair of left and right front wheels 13 that are steered wheels, a pair of left and right rear wheels 14, a driver's seat 18 in which the operator sits, a steering mechanism 15 that steers the pair of front wheels 13 to change the direction of travel of the vehicle body 2, a cabin 51 in which the driver's seat 18 is provided, an engine 4 as a power source for the work vehicle 1, a hood 10 that covers the engine 4, a transmission case 19 that changes the speed of the rotational power output from the engine 4, an operating section 16 (see FIG. 5) on which operating tools for operating various devices of the vehicle 1 are arranged, and a three-point linkage mechanism 7 that allows a work implement 3 to be attached to the rear of the vehicle body 2. The traveling vehicle body 2 according to this embodiment is configured as a tractor, and is capable of both automatic traveling by a control device 5 and manual traveling by a worker W.

[0024] The steering mechanism 15 includes a steering wheel 15a (hereinafter referred to as "SW") arranged inside the cabin 51 and a steering shaft 15b (hereinafter referred to as "SS") connected to the SW 15a. As will be described in detail later, the direction of the pair of front wheels 13 is changed by the steering mechanism 15, thereby changing the direction of travel of the vehicle body 2. The SW 15a and the SS 15b rotate integrally.

[0025] The transmission case 19 has inside it a hydrostatic continuously variable transmission (hereinafter referred to as "HST") that receives rotational power from the engine 4 to change speed, and an auxiliary transmission mechanism (not shown) that receives rotational power from the HST and changes speed to a speed according to the operating position of the auxiliary transmission lever 16e of the operating unit 16.

[0026] The HST starts, stops, increases, decreases, or reverses the rotational output to the auxiliary transmission mechanism by adjusting the trunnion opening angle through the drive of the HST servo motor 43 shown in FIG. 5. As a result, during automatic travel or manual travel by the operator W, the travel of the traveling vehicle body 2 is started, stopped, the vehicle speed is changed, or the vehicle body 2 is switched between forward and reverse. The forward and reverse travel of the vehicle body 2 can be switched by swinging the linear shift lever 16d, which is part of the operation unit 16. The transmission case 19 and the HST servo motor 43 are an example of a "transmission device" in the present invention. The rotational power changed in speed within the transmission case 19 is transmitted to the front wheels 13 and rear wheels 14 via the front axle 23 and rear axle 24, and to the work implement 3 via the PTO shaft 25.

[0027] In addition, by operating a switching lever located near the cockpit 18, the vehicle can be switched between a two-wheel drive state in which only the pair of rear wheels 14 are driven, and a four-wheel drive state in which the front wheels 13 and rear wheels 14 are driven.

[0028] Various types of implements can be attached to the rear of the traveling body 2, but in this embodiment, the explanation will be given using an implement 3 configured as a rotary tiller as an example. The implement 3 can till the field by rotating the tiller tines 3a using power transmitted from the PTO shaft 25.

[0029] The three-point link mechanism 7 comprises a top link 8 and a pair of left and right lower links 9 to which lift arms 27 (see Figure 1) extending from the rear of the traveling body 2 are attached, and is rotated by the extension and contraction of a pair of left and right lifting cylinders 26 provided at the rear of the traveling body 2.

[0030] Specifically, when hydraulic oil is supplied to the pair of left and right lift cylinders 26 by controlling lift valves 26c (see FIG. 5) that supply and discharge hydraulic oil to the lift cylinders 26, the pair of left and right lift arms 27 are rotated rearward and upward about axis AX extending laterally. The rear ends of each lift arm 27 are connected to the upper ends of a pair of left and right lift rods 52, the lower ends of which are connected to lower links 9. As the pair of lift arms 27 are rotated rearward and upward, the pair of lower links 9 are also rotated rearward and upward, and the work machine 3 is raised.

[0031] In contrast, when hydraulic oil is discharged from the lift cylinder 26 by controlling the lift valve 26c, the lift arm 27 is rotated rearward and downward about the axis AX, which in turn rotates the pair of lower links 9 rearward and downward, thereby lowering the work machine 3. The three-point linkage 7 is fixed to the rear of the transmission case 19.

[0032] 1 and 2, the vehicle body positioning device 11 is attached to the cabin roof 51a of the traveling vehicle body 2. The vehicle body positioning device 11 amplifies the GNSS signals from the GNSS satellites, acquires information on the transmission times of the GNSS signals, and then uses triangulation to measure (=locate) its own position, i.e., the position of the traveling vehicle body 2.

[0033] The work equipment positioning device 12 is attached to a bracket 3b located on the top of the work equipment 3, and in the same way as the vehicle body positioning device 11, it can measure (=position) its own position, i.e., the position of the work equipment 3, and obtain position information of the work equipment 3.

[0034] The work implement positioning device 12 is provided with a battery that stores power supplied from the vehicle body 2 through a connector (not shown) when the work implement 3 is attached to the vehicle body 2, and a communication unit that is capable of wireless communication with an autonomous driving ECU 30 (see FIG. 5 ) of the control device 5, which will be described in detail later. The work implement positioning device 12 and the communication unit are driven by power supplied from the battery. Therefore, even after the work implement 3 is detached from the vehicle body 2 and the supply of power from the vehicle body 2 is cut off, the work implement positioning device 12 can continue to transmit position information of the work implement 3 to the autonomous driving ECU 30 through the communication unit. Note that the calculation of the positions of the vehicle body 2 and the work implement 3 based on the information acquired by the vehicle body positioning device 11 and the work implement positioning device 12 may be configured to be performed by the control device 5.

[0035] The operation terminal 60 is equipped with a display 63 (see FIG. 10) equipped with a touch panel. The operation terminal 60 can display various operation screens on the display 63 based on a display instruction signal transmitted from the control device 5, and can also transmit an instruction signal to the control device 5 based on touch panel operation. FIG. 3 is a schematic plan view showing the vicinity of the lower part of the steering mechanism 15. As shown in FIG.

[0036] When the steering wheel 15a and the steering wheel 15b shown in FIG. 1 rotate together, the amount of rotation of the steering wheel 15b is detected by the steering sensor 21, and a hydraulic distributor (not shown) extends or retracts the power cylinder 15c shown in FIG. 3 in response to the amount of rotation of the steering wheel 15b. Tie rods 15d are connected to the left and right ends of the power cylinder 15c, respectively. When the power cylinder 15c extends or retracts, the left and right tie rods 15d slide left and right. Each tie rod 15d is connected to a knuckle arm 15e that is connected to a front final case 15f that rotatably supports the front wheel axle 23. Therefore, when the left and right tie rods 15d slide left and right, the left and right knuckle arms 15e and the front final case 15f rotate, changing the orientation of the pair of front wheels 13. 5, and during automatic driving, the steering motor 15g is driven by the control device 5 to rotate the SS 15b, thereby automatically changing the direction of travel of the vehicle body 2. The steering mechanism 15 is composed of the SW 15a, SS 15b, power cylinder 15c, a pair of left and right tie rods 15d, front final case 15f, steering motor 15g, etc.

[0037] 4 is a schematic perspective view showing a portion of the operating unit 16 disposed near the SW 15a. A fingertip lever 16a for raising and lowering the work implement 3, a turn signal lever 16b for indicating the traveling direction of the vehicle 1, and a throttle lever 16c for adjusting the rotation speed of the engine 4 are disposed substantially below the SW 15a. A position lever is also provided inside the cabin 51, and the work implement 3 can be raised and lowered by operating this position lever. The fingertip lever 16a is used to lower the work implement 3 or to raise it to the operating position of the position lever. The raising and lowering of the work implement 3 by operating the fingertip lever 16a or the position lever is performed by the control device 5 controlling the opening and closing of the lift valve 26c.

[0038] FIG. 5 is a control block diagram of the work vehicle 1 shown in FIG. The control device 5 includes a vehicle ECU 40 that controls the driving of the work vehicle 1, an automatic driving ECU 30 that sends control signals to the vehicle ECU 40 during automatic driving, and a work machine ECU 6 arranged in the work machine 3.

[0039] The automatic driving ECU 30 includes a recording unit 33 in which various information is recorded, a route calculation unit 31 that calculates the planned driving route, an automatic driving unit 32 that automatically drives the traveling vehicle body 2, and a removal detection unit 34 that detects the removal of the work equipment 3 from the traveling vehicle body 2.

[0040] The recording unit 33 records information such as the planned driving route, field shape information, position information of the vehicle body 2 and the work implement 3, the maximum attachment distance Dp, which will be described in detail later, the attachment position, and the distance from the removal position R to the intermediate point I.

[0041] In what is called teaching, the route calculation unit 31 calculates a planned driving route based on field shape information acquired by driving the vehicle 1 around the field under the control of the operator, and information on the working width of the work implement 3. The planned driving route can be calculated and set by the route calculation unit 31, or it can be acquired and set by the control device 5 from a server provided separately.

[0042] During automatic driving, the automatic driving unit 32 performs steering control to adjust the direction of travel of the vehicle body by controlling the steering mechanism 15, vehicle speed control to adjust the vehicle speed by controlling the HST etc., and driving stop control to stop the driving of the vehicle body 2.

[0043] In the steering control, the automatic driving unit 32 transmits steering information, which is information on a target steering angle of the SW 15a, to the vehicle ECU 40. Upon receiving the steering information, the vehicle ECU 40 controls the driving of the steering motor 15g based on the detection signal of the encoder 44 that detects the steering angle of the SW 15a and the steering information, and adjusts the steering angle of the SW 15a to the target steering angle.

[0044] In vehicle speed control, the automatic driving unit 32 transmits vehicle speed information, which is information on a target vehicle speed, to the vehicle ECU 40. Upon receiving the vehicle speed information, the vehicle ECU 40 drives a throttle motor 42 that adjusts the intake amount of the engine 4 and an HST servo motor 43 that adjusts the trunnion opening of the HST, based on a detection signal from a vehicle speed sensor 41 that detects the actual traveling speed of the traveling vehicle body 2, thereby controlling the actual vehicle speed to the target vehicle speed.

[0045] In the travel stop control, the automatic travel unit 32 outputs a travel stop signal to the vehicle ECU 40. Upon receiving the travel stop signal, the vehicle ECU 40 drives the HST servo motor 43 to cut off the travel output of the HST, and at the same time, sends a control signal to a brake control mechanism 47 that controls the supply and discharge of hydraulic oil to a brake cylinder (not shown) that operates the brake, thereby stopping the travel of the traveling vehicle body 2.

[0046] Meanwhile, based on a detection signal from lower link sensor 28 that detects the rotation angle of lower link 9 shown in FIG. 1, vehicle ECU 40 sends a control signal to lift valve 46 that controls the supply and discharge of hydraulic oil to lift cylinder 26, thereby raising or lowering mounting hitch 53 and work implement 3 to the target height position.

[0047] Here, the vehicle ECU 40 is configured to transmit a maximum distance signal to the autonomous driving ECU 30 when, with the work implement 3 attached to the traveling vehicle body 2, the lower link 9 first assumes an angle at which it extends substantially horizontally, i.e., when the work implement 3 first assumes a posture at which it is farthest from the traveling vehicle body 2 in the horizontal direction. Upon receiving the maximum distance signal from the vehicle ECU 40, the autonomous driving ECU 30 calculates a maximum attachment distance Dp, which is the distance between the position of the vehicle body 2 and the position of the work implement 3 at that time, based on the position information output from the positioning devices 11 and 12. The information on the maximum attachment distance Dp is then linked to the ID of the work implement 3 and recorded and set in the recording unit 33. The maximum attachment distance Dp is an example of a "set distance" in the present invention. The ID of the work implement 3 is transmitted from the work implement ECU 6 to the autonomous driving ECU 30 every time the work implement 3 is attached to the traveling vehicle body 2 and the work implement ECU 6 is connected to the autonomous driving ECU 30. It is not necessarily required to configure the maximum attachment distance Dp to be set when the lower link 9 rotates, and the maximum attachment distance Dp may be recorded in the recording unit 33 or the work implement ECU 6 at the time of factory shipment, or may be downloaded and set from a separate server. Also, a distance greater than the maximum attachment distance Dp may be set as the "set distance," which is the threshold value of the distance between the traveling vehicle body 2 and the work implement 3 at which the work implement 3 is regarded as having been detached from the vehicle body 2 and the position information of the work implement 3 is recorded as the detachment position R.

[0048] In the work vehicle 1 of this embodiment configured as described above, when changing the type of work implement attached to the traveling body 2, the work implement 3 can be removed from the traveling body 2 as follows.

[0049] Fig. 6 is a schematic left side view of the vicinity of the mounting hitch 53 showing the state in which the work implement 3 has been removed from the traveling body 2, and Fig. 7 is an exploded perspective view of the rear of the work vehicle 1. For convenience, the work implement positioning device 12 has been omitted from Fig. 7.

[0050] The mounting hitch 53 has a first fixing portion 53b to which the top link 8 of the three-point link mechanism 7 is fixed, a second fixing portion 53c to which the lower link 9 is fixed, a first engagement recess 53d that engages with a first bar 3c extending left and right and provided on the bracket 3b of the work machine 3, and a second engagement recess 53e that engages with a pair of left and right second bars 3d extending left and right and provided on the work machine 3.

[0051] When the work implement 3 is to be removed from the traveling body 2 at a placement location of the work implement 3, first, the worker W pulls the lock release lever 53a of the mounting hitch 53 forward and upward, thereby releasing the engagement between the second engagement recess 53e and the second bar 3d.

[0052] Next, when the worker W lowers the work implement 3 using the finger-up lever 16a or the position lever, the pair of lower links 9 are rotated rearward and downward, and the mounting hitch 53 is lowered. As a result, the engagement between the first engagement recess 53d and the first bar 3c is released.

[0053] When the engagement at the two points is thus released and the work implement 3 is removed from the traveling body 2, the traveling body 2 moves forward by manual driving under the control of the worker W, away from the work implement 3, and moves to a location where another work implement is located, etc. At this time, the removal detection unit 34 of the automatic driving ECU 30 detects the removal of the work implement 3 from the vehicle body 2 in the following manner.

[0054] Figure 8 is a flowchart related to the detection of the removal of the work implement 3 by the removal detection unit 34 while the control device 5 is operating, and Figure 9 is a schematic plan view showing the traveling vehicle body 2 moving away from the work implement 3 after the work implement 3 has been removed.

[0055] The removal detection unit 34 first acquires the position information of the vehicle body 2 measured by the vehicle body positioning device 11 and the position information of the work implement 3 measured by the work implement positioning device 12 (step s1).

[0056] Next, based on the acquired position information, the removal detection unit 34 calculates the distance D between the position of the vehicle body 2 and the position of the work implement 3 (hereinafter referred to as the "separation distance"), and then determines whether or not the separation distance D exceeds the maximum attachment distance Dp set in advance as described above (step s2).

[0057] If the result of the determination is that the separation distance D is equal to or less than the maximum attachment distance Dp, the removal detection unit 34 repeats steps s1 and s2 until the separation distance D exceeds the maximum attachment distance Dp.

[0058] On the other hand, if the determination result shows that the separation distance D exceeds the maximum attachment distance Dp, it is recognized that the work implement 3 has been detached from the traveling body 2, and the detachment detection unit 34 stores (=records) the current position information of the work implement 3 as position information indicating the detachment position R of the work implement 3, linked to the ID of the work implement 3, in the recording unit 33 (step s3).

[0059] Next, immediately after the work implement 3 is detached, the detachment detection unit 34 acquires information on the heading V of the traveling vehicle body 2 while the traveling vehicle body 2 is manually traveling a predetermined distance (in other words, when the traveling vehicle body 2 moves away from the work implement 3), and information on the traveling direction M of the traveling vehicle body 2, and records these in the recording unit 33 (step s4). Hereinafter, the heading V of the traveling vehicle body 2 recorded immediately after the work implement 3 is detached is referred to as the "post-detachment vehicle body heading," and the direction M in which the traveling vehicle body 2 travels immediately after the work implement 3 is detached is referred to as the "post-detachment traveling direction." In this embodiment, the heading acquisition means is configured such that the heading sensor 45 acquires information on the heading of the traveling vehicle body 2, and the traveling direction acquisition means is configured such that the detachment detection unit 34 acquires information on the post-detachment traveling direction M of the vehicle body 2 by connecting multiple pieces of position information measured by the vehicle body positioning device 11 while the vehicle body 2 moves a predetermined distance, but the heading acquisition means and the traveling direction acquisition means are not limited to these. For example, an acceleration sensor such as an IMU can be used as the traveling direction acquisition means.

[0060] On the other hand, in this embodiment, the working implement 3 can be easily attached to the vehicle body 2 by moving the traveling vehicle body 2 closer (=approaching) to the removal position R where the working implement 3 is estimated to be located, using the following procedure.

[0061] FIG. 10 is a diagram showing a travel instruction screen displayed on the operation terminal 60, and FIG. 11 is a flowchart relating to control for moving the traveling vehicle body 2 closer to the removal position R of the work implement 3.

[0062] The operation terminal 60 is provided with a travel instruction screen that displays a list of work machines that have been attached to the traveling body 2 and whose IDs have been sent from the work machine ECU to the control device 5. On the travel instruction screen, travel instruction switches 61, 62 that the worker W uses to input instruction signals to the control device 5 for moving the traveling body 2 closer to the removal position of each work machine are displayed below the icons i1, i2 of each work machine, including the work machine 3 configured as a rotary tiller. Hereinafter, the instruction signal for moving the traveling body 2 closer to the removal position of each work machine is referred to as the "travel instruction signal."

[0063] When the worker W presses the travel instruction switch 61 to install the work implement 3, a travel instruction signal is sent from the operation terminal 60 together with the ID of the work implement 3 and input to the control device 5. At this time, the worker W may be inside the cabin 51 or outside the vehicle body 2.

[0064] In this embodiment, the driving instruction switches 61, 62, which are an example of the "first input operation means" of the present invention, are configured to be displayed on the operation terminal 60. However, the operation means for inputting driving instruction signals to the control device 5 may be arranged on the traveling body 2, on each work machine including the work machine 3, or on a separately provided remote controller. The operation means may be configured as a switch displayed on a display, or may be arranged as a mechanical switch. When arranged on the traveling body 2 as a mechanical switch, the driving instruction signal is configured to be input to the control device 5 when the driving instruction switch is operated. In this case, it is preferable to arrange the driving instruction switch on a lever guide (not shown) on the right side of the traveling body 2. When the driving instruction switch is arranged on the work machine 3, it is preferable that the driving instruction signal be transmitted (i.e., input) to the control device 5 via a communication unit of the work machine 3. The same applies to the configuration and arrangement of the re-driving instruction switch 64, which will be described in detail later.

[0065] 12 is a schematic plan view showing the positional relationship when the traveling vehicle body 2 is brought closer to the removal position R of the work implement 3. In FIG. 12, the movement of the vehicle body 2 in steps S5 and S6 shown in FIG. 11 is indicated by arrows, and the left end of the arrow for step S5 and the entire arrow for step S6 are drawn slightly away from the traveling reference line L to distinguish them from the traveling reference line L. However, in reality, these should overlap with the traveling reference line L.

[0066] When receiving a driving instruction signal transmitted by pressing the driving instruction switch 61 (step S1), the autonomous driving ECU 30 calculates the angle difference between the current orientation of the traveling vehicle body 2 acquired by the orientation sensor 45 and the post-detachment vehicle body orientation V (see step s4 in Fig. 9 and Fig. 8), and then determines whether the angle difference is equal to or smaller than a predetermined allowable angle (step S2).

[0067] If the determination result shows that the differential angle exceeds the allowable angle, the autonomous driving ECU 30 calculates the value of the vehicle body orientation change angle, which is the angle obtained by subtracting the value of the allowable angle from the value of the differential angle (step S3). In other words, the vehicle body orientation change angle is the minimum angle at which the orientation of the traveling vehicle body 2 must be changed so that the differential angle between the current orientation of the traveling vehicle body 2 and the post-removal vehicle body orientation V becomes equal to or smaller than the allowable angle at which automatic traveling to the traveling reference line L, which will be performed later, can be started.

[0068] When the vehicle body heading change angle is calculated, the autonomous driving ECU 30 transmits a display instruction signal together with information about the vehicle body heading change angle, and displays a message on the display 63 of the operation terminal 60 requesting a certain number of degrees (= vehicle body heading change angle) and a direction to change the direction of the traveling vehicle body 2 (step S4). For example, if the current direction of the traveling vehicle body 2 is 40 degrees off to the right (= clockwise in plan view) with respect to the post-detachment vehicle body heading V (= differential angle is 40 degrees) and the allowable angle is 30 degrees, the vehicle body heading change angle is 10 degrees, so the display of the operation terminal 60 displays a message saying, "Please change the direction of the vehicle body to the left by 10 degrees or more." Thereafter, the calculation of the differential angle, the determination of whether the angle is below the allowable angle, the calculation of the vehicle body heading change angle, and the display on the operation terminal 60 are repeated until the differential angle becomes below the allowable angle.

[0069] On the other hand, if the result of the judgment in step S2 is that the differential angle is less than or equal to the allowable angle, the automatic driving unit 32 of the automatic driving ECU 30 reverses the traveling vehicle body 2 by automatic driving until it passes through the removal position R recorded in step s4 of Figure 8 and reaches a virtual traveling reference line L that is set parallel to the post-removal traveling direction M (step S5).

[0070] At this time, the automatic driving unit 32 first generates steering information each time so as to shorten the distance between the driving reference line L and the position of the vehicle body 2 measured by the vehicle body positioning device 11, and transmits this information to the vehicle ECU 40. Thereafter, when the position of the vehicle body 2 approaches the driving reference line L to a predetermined distance, the automatic driving unit 32 generates steering information and adjusts the steering angle of the SW15a so that the position of the traveling vehicle body 2 comes onto the driving reference line L and the orientation of the traveling vehicle body 2 coincides with the post-detachment vehicle body orientation V. In the work vehicle 1 according to this embodiment, the work implement 3 is attached to the rear of the traveling vehicle body 2, so the traveling vehicle body 2 is moved backward in step S4, but if the work implement were attached to the front of the traveling vehicle body, the traveling vehicle body would be moved forward in step S4.

[0071] Next, the automatic driving unit 32 refers to the position information of the removal position R recorded in the recording unit 33, and starts automatic driving of the traveling vehicle body 2 in a direction opposite to the post-removal traveling direction M, with the removal position R as the target, while facing in approximately the same direction as the post-removal vehicle body orientation V (step S6). At this time, the automatic driving unit 32 generates steering information each time so as to shorten the distance between the position of the vehicle body 2 acquired by the vehicle body positioning device 11 and the driving reference line L, and transmits the steering information to the vehicle ECU 40, thereby causing the vehicle body 2 to travel along the driving reference line L. At the same time, the automatic driving unit 32 outputs an instruction signal to the vehicle ECU 40 to cause the vehicle speed sensor 41 to acquire vehicle speed information during automatic driving and transmit it to the automatic driving ECU 30. The obtained vehicle speed information is then recorded in the recording unit 33.

[0072] Next, based on the positioning results of the vehicle body positioning device 11, the automatic driving unit 32 determines whether the vehicle body 2 has reached an intermediate point I located on the driving reference line L and a predetermined distance Ds away from the removal position R (step S7). If the result of the determination is that the vehicle body 2 has not reached the waypoint I, the automatic driving unit 32 repeats the determination until the vehicle body 2 reaches the waypoint I.

[0073] On the other hand, if the determination result indicates that the vehicle body 2 has reached the waypoint I, the automatic driving unit 32 performs travel stop control and stops the vehicle body 2 at the waypoint I (step S8). At the same time, the vehicle ECU 40 sends a control signal to the lift valve 46 to lower the position of the attachment hitch 53. The target lowering position of the attachment hitch 53 at this time is a position where the first engagement recess 53d of the attachment hitch 53 is located lower than the first bar 3c of the work implement 3 that has been detached from the vehicle body 2. When the vehicle body 2 is stopped, the traveling vehicle body 2 is in the positional relationship with the work implement 3 shown in FIGS. 13 and 14. Note that in step S6, it is not necessarily necessary to automatically drive the traveling vehicle body 2 in the direction opposite to the traveling direction M after detachment, with the detachment position R as the target. The traveling vehicle body 2 may also be configured to automatically drive in the direction opposite to the traveling direction M after detachment, with the waypoint I as the target.

[0074] Figure 13 is a schematic plan view showing the positional relationship between the vehicle body 2 and the work equipment 3 when the traveling vehicle body 2 is stopped at the intermediate point I, and Figure 14 is a schematic left side view showing the positional relationship between the vehicle body 2 and the work equipment 3 when the traveling vehicle body 2 is stopped at the intermediate point I.

[0075] When the traveling vehicle body 2 has stopped, as shown in Figures 13 and 14, the vehicle body 2 is in a position close to the work implement 3, but there is still a horizontal distance between the mounting hitch 53 and the work implement 3. The worker W can get off the vehicle body 2 and check the relative positions of the traveling vehicle body 2 and the work implement 3.

[0076] When the vehicle body 2 stops, the autonomous driving ECU 30 transmits a display instruction signal to the operation terminal 60, causing the operation terminal 60 to display a restart instruction screen shown in Fig. 15 (step S9). Fig. 15 is a diagram showing the restart instruction screen displayed on the operation terminal 60 after the running stop control has been performed.

[0077] As shown in Fig. 15, the re-travel instruction screen is provided with a re-travel instruction switch 64 used to input an instruction signal to the control device 5 to cause the stopped traveling vehicle body 2 to automatically travel again in the direction opposite to the traveling direction after removal, and a process end switch 65. The re-travel instruction switch 64 is an example of the "second input operation means" of the present invention. When the process end switch 65 is pressed, an end instruction signal to end the process shown in Fig. 11 is transmitted from the operation terminal 60 to the control device 5, and the process by the control device 5 ends. In this case, the worker W manually drives the vehicle body 2 backward to the attachment position.

[0078] The attachment position refers to the position of the traveling body 2 when the first engagement recess 53d of the attachment hitch 53 is located below the first bar 3c of the work implement 3. When the traveling body 2 is in the attachment position, as will be described in detail later, the work implement 3 can be attached to the traveling body 2 simply by raising the attachment hitch 53. Even when the processing end switch 65 is pressed, as described above, the body 2 is automatically moved to the intermediate point I close to the removal position R, so the worker W can easily reverse the body 2 to the attachment position while checking what is behind.

[0079] On the other hand, when the re-travel instruction switch 64 is pressed, a re-travel instruction signal for automatically traveling the traveling vehicle body 2 to the attachment position is transmitted from the operation terminal 60 to the control device 5. When the re-travel instruction signal is input to the control device 5 (step S10), the automatic traveling unit 32 automatically travels backward the vehicle body 2 to the attachment position along the traveling reference line L in the direction opposite to the post-removal traveling direction M, with the vehicle body 2 facing in approximately the same direction as the post-removal vehicle body orientation V (step S11).

[0080] Here, information on the attachment position of the traveling vehicle body 2 is recorded in advance in the recording unit 33 as distance information of a predetermined length from the position of the work implement 3, and the automatic traveling unit 32 reads out the distance information of the predetermined length from the recording unit 33 when a re-travel instruction signal is input to the control device 5. Then, the automatic traveling unit 32 is configured to set a position that is the predetermined distance away from the removal position R in the post-removal traveling direction M as the attachment position, and to automatically travel the vehicle body 2 to the attachment position.

[0081] While the traveling vehicle body 2 is automatically traveling to the attachment position, the automatic traveling unit 32 causes the vehicle body 2 to move backward to the attachment position at a speed (in simple terms, at a very slow speed) that is much slower than the speed at which the vehicle body 2 was automatically traveling to the waypoint I in step S6. At the same time, the automatic driving ECU 30 sends a display instruction signal to display a traveling stop switch (not shown) on the display of the operation terminal 60 to instruct the execution of traveling stop control. This allows the worker W to safely monitor the automatic traveling of the vehicle body 2 and, in the unlikely event of an emergency, to stop the traveling of the vehicle body 2 by pressing the traveling stop switch. It is not necessarily necessary to display a traveling stop switch that instructs the execution of traveling stop control on the operation terminal 60. A separate remote controller for sending an instruction signal to the control device 5 may be provided, and a mechanical traveling stop switch may be arranged on the remote controller. It is to be noted that in a configuration in which the work machine is attached to the front of the traveling vehicle body, the traveling vehicle body is moved forward to the attachment position in step S6. When the traveling vehicle body 2 reaches the attachment position, the automatic traveling unit 32 performs traveling stop control and stops the vehicle body 2 at the attachment position (step S12).

[0082] Figure 16 is a schematic left side view showing how the work implement 3 is attached to the traveling body 2 which is in the attachment position. More specifically, Figure 16(a) is a schematic left side view showing the state before the attachment hitch 53 is raised, and Figure 16(b) is a schematic left side view showing the state when the attachment hitch 53 is in the middle of being raised.

[0083] 11, when the traveling body 2 is moved to the attachment position, the worker W operates the finger-up lever 16a or the position lever, thereby rotating the lower link 9 rearward and upward, and raising the attachment hitch 53. As a result, as shown in FIG. 16(b), the first engagement recess 53d of the attachment hitch 53 engages with the first bar 3c of the work implement 3.

[0084] After the upper part is engaged in this manner, the mounting hitch 53 is further raised, lifting the work implement 3, and as shown in Figure 16(b), the shift in the center of gravity causes the work implement 3 to rotate clockwise around the first bar 3c as viewed from the left side. As a result, the pair of left and right second bars 3d of the work implement 3 are inserted into and engaged with the second engagement recesses 53e of the mounting hitch 53, completing the attachment of the work implement 3.

[0085] As described above, in the work vehicle 1 according to this embodiment, the travel instruction switch 61 is pressed, then the re-travel instruction switch 64 is pressed, and then the fingertip lever 16a or the position lever is simply operated to attach the work implement 3 to the vehicle body 2. <Technical significance of this embodiment>

[0086] According to this embodiment shown in Figures 1 to 16, when a travel instruction signal is input to the control device 5 by pressing a travel instruction switch 61 (see Figure 10), which is an example of the "first input operation means" of the present invention, the control device 5 is configured to automatically travel the traveling body 2 to the removal position R (see Figure 12), thereby reducing the workload of attaching the work implement 3 to the traveling body 2.

[0087] Furthermore, according to this embodiment, the control device 5 is configured to record the current position information of the work machine 3 as position information indicating the removal position R of the work machine 3, provided that the traveling vehicle body 2 and the work machine 3 are farther apart than the predetermined maximum attachment distance Dp. Therefore, the worker W does not need to record the removal position of the work machine 3 by performing some kind of operation, thereby reducing the burden on the worker W.

[0088] In addition, according to this embodiment, the post-removal vehicle body orientation V and post-removal traveling direction M (see Figure 9), which are the orientation and traveling direction of the vehicle body 2 when the traveling body 2 leaves the work machine 3, are recorded, and when the traveling body 2 is automatically driven to the removal position R of the work machine 3, the vehicle body 2 is configured to travel in the opposite direction to the recorded post-removal traveling direction M while facing in approximately the same orientation as the recorded post-removal vehicle body orientation V, so that the traveling body 2 can be moved to the left or right position of the vehicle body 2 when it leaves the position of the work machine 3.

[0089] Furthermore, according to this embodiment, the traveling body 2 is automatically driven in the opposite direction to the post-detachment traveling direction M, which is the traveling direction when the traveling body 2 leaves the work machine 3, thereby reducing the risk of the traveling body 2 coming into contact with some kind of obstacle.

[0090] Furthermore, according to this embodiment, the traveling body 2 stops traveling when it reaches an intermediate point I that is a predetermined distance away from the removal position R of the work implement 3, so that the worker W can check the distance between the traveling body 2 and the work implement 3, thereby improving safety.

[0091] In addition, according to this embodiment, after the traveling vehicle body 2 stops traveling at the intermediate point I, when it is automatically caused to travel further in the direction of the work implement 3, it is configured to automatically travel at a vehicle speed lower than the vehicle speed before it stopped traveling, so that the worker W can monitor the traveling of the traveling vehicle body 2 with peace of mind.

[0092] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these modifications are also included within the scope of the present invention.

[0093] For example, in the above embodiment, the running body 2 is configured as a tractor, but it is not necessarily required that the running body 2 be configured as a tractor, and the type is not limited as long as the working machine 3 that performs agricultural work can be detachably attached.

[0094] Furthermore, in the above embodiment, the work implement 3 is constituted by a rotary tiller, but the type of work implement according to the present invention is not limited to this and may be a brush cutter, laser leveller, cultivator, ridger, broadcaster, transplanter, etc.

[0095] Additionally, in the above embodiment, the work implement 3 is configured to be mountable to the rear side of the traveling body 2, but the work implement 3 may also be mountable to the front side of the traveling body 2. In this case, when the work implement is mounted, the traveling body can be moved forward by automatic travel in the opposite direction to the traveling direction when the work implement was detached, so that the traveling body can easily approach the work implement.

[0096] Furthermore, in the above embodiment, the work machine 3 is provided with a communication unit capable of wireless communication and a power source constituted by a battery, but it is not necessarily required that the work machine be provided with wireless communication means and a power source. For example, when the work machine is detached and communication with the control unit is lost, the position information of the work machine 3 last received from the work machine 3 side can be recorded as the detachment position, and the traveling vehicle body can be configured to approach the detachment position by automatic travel.

[0097] Furthermore, in the above embodiment, vehicle ECU 40 is configured to rotate lower link 9 and raise or lower mounting hitch 53 and work implement 3 by sending a control signal to lift / lower valve 46 based on a detection signal from lower link sensor 28 that detects the rotation angle of lower link sensor 28, but a sensor that detects the rotation angle of lift arm 27 may be provided instead of lower link sensor 28, and a control signal may be sent to lift / lower valve 46 based on a detection signal from the sensor to rotate lower link 9 and raise or lower mounting hitch 53 and work implement 3. In this case, vehicle ECU 40 can be configured to send a maximum distance signal to autonomous driving ECU 30 when work implement 3 is at an angle that is farthest apart horizontally from traveling vehicle body 2 based on the detection signal from the sensor.

[0098] Additionally, in the above embodiment, when a driving instruction signal is input, the control device 5 is configured to first calculate the differential angle between the current orientation of the traveling vehicle body 2 and the post-removal vehicle body orientation V, and to start automatic driving of the traveling vehicle body 2 on the condition that the differential angle is equal to or less than a predetermined allowable angle. However, instead of or in addition to the above condition, automatic driving may be started on the condition that the linear shift lever 16d is operated to set the vehicle body 2 to a reverse position, or on the condition that the auxiliary shift lever 16e is operated to an operating position other than high speed. This prevents unintentional start of automatic driving of the vehicle body 2 and improves safety during automatic driving. Furthermore, when a driving instruction signal is received, it is not necessarily required to start automatic driving on the condition that the differential angle between the orientation of the vehicle body 2 and the post-removal vehicle body orientation is equal to or less than the allowable angle. Automatic driving may be started unconditionally when a driving instruction signal is input. Furthermore, when a driving instruction signal is input, the distance between the current position of the traveling vehicle body 2 and the driving reference line L may be calculated, and the traveling vehicle body 2 may be configured to start automatic driving on the condition that the distance is less than a predetermined allowable distance.

[0099] Furthermore, in the above embodiment, the control device 5 is configured to automatically reverse the traveling body 2 to the attachment position where the first engagement recess 53d of the attachment hitch 53 is located below the first bar 3c of the work implement 3 when a re-travel instruction signal is input, but it may also be configured to record the position of the traveling body 2 when recording the removal position R of the work implement 3, and to automatically reverse the traveling body 2 to the recorded position of the traveling body 2 when a re-travel instruction signal is input.

[0100] Furthermore, in the above embodiment, the work implement 3 is configured to be attached to the traveling body 2 via the attachment hitch 53, but the work implement 3 may also be configured to be attached directly to the traveling body 2 without the attachment hitch 53.

[0101] Additionally, in the above embodiment, after the traveling body 2 has been moved to the attachment position by automatic travel under the control of the control device 5, the attachment hitch 53 is raised by the operation of the worker W, thereby attaching the work implement 3 to the body 2. However, the control device 5 may be configured to automatically raise the attachment hitch 53 when the traveling body 2 stops at the attachment position. This further reduces the workload of the worker W.

[0102] Furthermore, in the above embodiment, the work vehicle 1 is provided with a transmission case 19 and an HST servo motor 43 as an example of a transmission, but an electric motor or the like may be provided as another example of a transmission. When changing the vehicle speed using an electric motor, the vehicle can be configured as a so-called EV vehicle in which the front and rear axles 23, 24 are rotated by driving the electric motor, and the vehicle speed can be changed by changing the rotational speed of the electric motor. [Explanation of symbols]

[0103] 1 Work vehicle 2 Running vehicle 3 Work equipment 4 Engine 5. Control device 6 Work machine ECU 7 Three-point linkage mechanism 8 Top Links 9 Lower Link 10. Hood 11 Vehicle positioning device 12 Work equipment positioning device 13 Front wheel 14 rear wheels 15 Steering mechanism 16 Control section 18 cockpit 21 Steering sensor 23 Front axle 24 rear wheel axle 25 PTO shaft 26 Lifting cylinder 27 Lift arm 30 Autonomous Driving ECU 32 Automatic driving unit 33 Recording Section 34 Removal detection unit 40 Vehicle ECU 41 Vehicle speed sensor 42 Throttle motor 43 HST servo motor 44 Encoder 45 Orientation sensor 46 Lifting valve 47 Brake control mechanism 51 Cabin 52 Lift Rod 53 Mounting hitch 60 Operation terminal D Separation distance Dp Maximum installation distance I Midpoint L Travel reference line M Direction of movement after removal R Removal position V Vehicle orientation after removal

Claims

1. An agricultural work vehicle, a traveling vehicle body having a transmission for changing the vehicle speed and a steering mechanism for changing the traveling direction of the vehicle body; a work machine removably attached to the traveling vehicle body; a vehicle positioning device for measuring the position of the traveling vehicle; a work machine positioning device that measures the position of the work machine and acquires position information; a control device that controls the transmission and the steering mechanism to automatically drive the traveling vehicle body; a first input operation means used by an operator to input to the control device an instruction signal for moving the traveling vehicle body closer to the position of the work machine, The control device records the current position information of the work machine as position information indicating the removal position of the work machine, on the condition that the position of the traveling vehicle body measured by the vehicle body positioning device and the position of the work machine measured by the work machine positioning device are separated by more than a preset distance, and then When an instruction signal is input using the first input operation means, the work vehicle automatically travels the traveling body to the removal position by referring to position information indicating the removal position.

2. An orientation acquisition means for acquiring an orientation in which the traveling vehicle body is facing; a traveling direction acquisition means for acquiring a traveling direction of the traveling vehicle body, After recording the position information of the removal position, the control device records the orientation of the traveling vehicle body acquired by the orientation acquisition means and the traveling direction acquired by the traveling direction acquisition means, on the condition that the position of the traveling vehicle body measured by the vehicle body positioning device has moved away from the position of the work machine measured by the work machine positioning device, and then The work vehicle according to claim 1, characterized in that, when the control device automatically drives the traveling body toward the removal position, the control device automatically drives the traveling body past the removal position and onto a traveling reference line that is set parallel to the traveling direction, and then automatically drives the traveling body in a direction that is approximately the same as the recorded direction.

3. 3. The work vehicle according to claim 1, wherein the control device is configured to stop the traveling body from traveling when the traveling body reaches a point that is a predetermined distance away from the removal position.

4. a second input operation means used by an operator to input to the control device an instruction signal for causing the traveling vehicle body to further automatically travel in the opposite direction to the traveling direction after the traveling vehicle body has stopped traveling, the control device is configured to record the vehicle speed when the traveling vehicle body is automatically driven to a point separated by a predetermined distance, 3. The work vehicle according to claim 2, wherein when an instruction signal is input using the second input operation means, the control device automatically drives the traveling vehicle body at a speed lower than the speed at which the traveling vehicle body automatically drives to a point a predetermined distance away.

Images