Work vehicle

Abstract

In order to stably and safely perform automatic steering when a work vehicle (1) is backing up, the work vehicle (1) is provided with: a vehicle body (3) capable of traveling forward and backward by either manual steering by a steering wheel (30) or automatic steering; a power machine (4) provided to the vehicle body; a work device (2) supported by the vehicle body; a PTO shaft (16) that transmits power of the power machine to the work device; and a control device (60) that controls the automatic steering and driving of the PTO shaft, wherein the control device permits the automatic steering when the vehicle body is backing up when the PTO shaft is stopped, and the control device prohibits the automatic steering when the vehicle body is backing up when the PTO shaft is driven.

Description

TECHNICAL FIELD

[0001] The present application relates to a work vehicle such as a tractor. BACKGROUND

[0002] In the past, a work vehicle of Patent Literature 1 is known. The work vehicle of Patent Literature 1 is provided with: a vehicle body capable of traveling forward and backward by either one of manual steering by a steering wheel and automatic steering; a PTO (Power Take Off) shaft that transmits power of a power machine provided to the vehicle body to a work device supported at a rear of the vehicle body; and a control device that controls driving of the automatic steering and the PTO shaft.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Publication Gazette "Patent No. 2020-54316" SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In the work vehicle of Patent Literature 1, in a state where the rotational speed of the PTO shaft is rising, in the case of backing up by the automatic steering, depending on the work state of the work device, it can be difficult to stably perform the automatic steering, or it can cause a danger to a driver who looks back from a driver's seat of the vehicle body toward the rear.

[0008] Therefore, the present application aims to stably and safely perform the automatic steering at the time of backing up of the work vehicle in view of the above-described problems.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The technical means of the present application for solving the above-described technical problems is characterized by the points shown below.

[0011] A work vehicle of one embodiment of the present application is provided with: a vehicle body capable of traveling forward and backward by either one of manual steering by a steering wheel and automatic steering; a power machine provided to the vehicle body; a work device supported to the vehicle body; a PTO (Power Take Off) shaft that transmits power of the power machine to the work device; and a control device that controls driving of the automatic steering and the PTO shaft, the control device permitting the automatic steering at the time of backing up of the vehicle body when the PTO shaft is stopped, and the control device prohibiting the automatic steering at the time of backing up of the vehicle body when the PTO shaft is driven.

[0012] In addition, in one embodiment of the present application, the work vehicle is provided with a PTO operation member that is an operation member for operating driving of the PTO shaft, is capable of being switched from a neutral position to a driving position, the PTO shaft is stopped when the PTO operation member is in the neutral position, the control device permits automatic steering when the vehicle body is backed up, the control device prohibits automatic steering when the vehicle body is backed up when the PTO operation member is switched to the driving position, and the PTO shaft is capable of being driven.

[0013] In addition, in one embodiment of the present application, the work vehicle is provided with a positioning device that is capable of detecting a position of the vehicle body, a setting switch that is operated for setting of a travel reference line that is a reference of automatic steering, and a steering switch that is operated for indicating start and stop of automatic steering, the control device sets the travel reference line based on the position of the vehicle body detected by the positioning device at the time of travel of the vehicle body by manual steering in accordance with operation of the setting switch, starts automatic steering in accordance with start operation of the steering switch in a case where automatic steering when the vehicle body is backed up is permitted, performs automatic steering based on the travel reference line and the position of the vehicle body detected by the positioning device, and stops automatic steering in accordance with stop operation of the steering switch, and the control device does not perform start and stop of automatic steering in accordance with operation of the steering switch in a case where automatic steering when the vehicle body is backed up is prohibited.

[0014] In addition, in one embodiment of the present application, the work vehicle is provided with a notification device that notifies of a case where automatic steering when the vehicle body is backed up is prohibited.

[0015] In addition, in one embodiment of the present application, the notification device further notifies of guidance that prompts the PTO shaft to be stopped.

[0016] In addition, in one embodiment of the present application, in a case where automatic steering when the vehicle body is backed up is prohibited, the notification device performs the above notification at the time of indicating start of automatic steering.

[0017] Effects of the Invention

[0018] According to the present application, it is possible to stably and safely perform automatic steering when the work vehicle is backed up. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a control block diagram of the work vehicle.

[0020] Figure 2 is a detailed view of the PTO shift lever.

[0021] Figure 3 is an explanatory view of automatic steering.

[0022] Figure 4This is a diagram showing the actions of a work vehicle traveling straight based on automatic steering.

[0023] Figure 5 It is a diagram showing the automatic steering status of the working vehicle when it is moving forward and backward.

[0024] Figure 6 This is a diagram showing the control panel located in front of the driver's seat.

[0025] Figure 7 It is a 3D view of the work vehicle.

[0026] Figure 8 This is a 3D view of the area near the second operating section.

[0027] Figure 9 This is a flowchart illustrating the actions of the work vehicle.

[0028] Figure 10 This is a detailed diagram of a PTO switch.

[0029] Figure 11 This is a diagram showing another example of the second operating unit.

[0030] Figure 12 This is a side view of the work vehicle. Detailed Implementation

[0031] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0032] First, the appearance of the work vehicle 1 in this embodiment will be described. Figure 12 This is a side view of the work vehicle 1. The work vehicle 1 in this embodiment is a tractor. However, the work vehicle of the present invention is not limited to... Figure 12 The tractor shown can also be agricultural machinery (agricultural vehicles) such as combine harvesters and transplanters, or construction machinery (construction vehicles) such as loaders.

[0033] The following will describe the area in front of the driver, who is seated in the driver's seat 10 of the work vehicle 1. Figure 12 (Arrow A1 direction) is set forward, and the driver's rear side ( Figure 12 The direction of arrow A2 is defined as rear, the driver's left side as left, and the driver's right side as right. Additionally, the direction perpendicular to the front-rear direction of the work vehicle 1, i.e., the horizontal direction, is defined as the vehicle's width direction.

[0034] like Figure 12As shown, the work vehicle 1 is provided with a vehicle body 3, a power machine 4, and a traveling device 7. The vehicle body 3 is able to travel forward and backward by the traveling device 7. The traveling device 7 has front wheels 7F and rear wheels 7R. The front wheels 7F can be of a tire type or a track type. Also, the rear wheels 7R can be of a tire type or a track type. The power machine 4 is constituted by a diesel engine. As other examples, the power machine 4 can be constituted by an electric motor or the like.

[0035] A driver's seat 10 is provided at an upper portion of the vehicle body 3. A hitch portion (omitted from illustration) including a lifting device 8 is provided at a rear portion of the vehicle body 3. The work device 2 is able to be attached to and detached from the hitch portion. By hitching the work device 2 to the hitch portion, the work device 2 is supported at a rear of the vehicle body 3, and the vehicle body 3 is able to tow the work device 2. The work device 2 is a tiller device that tills, a fertilizer spreading device that spreads fertilizer, a pesticide spreading device that spreads pesticide, a harvester device that harvests, a mower device that mows grass or the like, a spreader device that spreads grass or the like, a grass collector device that collects grass or the like, a shaper device that shapes grass or the like, or the like.

[0036] An operation platform 9F is provided at a front of the driver's seat 10 of the vehicle body 3. Operation portions such as a steering wheel 30, levers, switches, and the like are provided at the operation platform 9F. An operation platform 9L is provided at a left side of the driver's seat 10, and an operation platform 9R is provided at a right side (see FIG. 2) thereof. Operation portions such as levers, switches, and the like are also provided at the operation platforms 9L, 9R, respectively. Figure 7 ) thereof. Operation portions such as levers, switches, and the like are also provided at the operation platforms 9L, 9R, respectively.

[0037] A safety frame 6 is provided at a position of the vehicle body 3 that is rearward of the driver's seat 10. The safety frame 6 is an example of a protection mechanism that protects a driver seated at the driver's seat 10 when the work vehicle 1 overturns, for example.

[0038] Next, the structure of the work vehicle 1 will be described. Figure 1 is a control block diagram of the work vehicle 1. The work vehicle 1 is provided with a transmission device 5, differential devices 20F, 20R, the lifting device 8, a steering device 11, a control device 60, a positioning device 40, a display device 45, work valves 25 to 29, and switches 23, 24, 50 to 54.

[0039] The transmission 5 is capable of switching the propulsive force of the traveling device 7 by shifting gears, and is capable of switching forward and reverse of the traveling device 7. The transmission 5 is provided with a propeller shaft (main shaft) 5a, a main transmission portion 5b, a sub-transmission portion 5c, a shuttle portion 5d, a PTO power transmission portion 5e, and a front transmission portion 5f. The propeller shaft 5a is rotatably supported to a case (transmission case) of the transmission 5. The power from the crankshaft of the power unit 4 is transmitted to the propeller shaft 5a. The main transmission portion 5b has a plurality of gears and a shift lever that changes the connection of the gears. The main transmission portion 5b changes and outputs (shifts) the rotation input from the propeller shaft 5a by appropriately changing the connection (meshing) of the plurality of gears using the shift lever.

[0040] The sub-transmission portion 5c, like the main transmission portion 5b, has a plurality of gears and a shift lever that changes the connection of the gears. The sub-transmission portion 5c changes and outputs (shifts) the rotation input from the main transmission portion 5b by appropriately changing the connection (meshing) of the plurality of gears using the shift lever.

[0041] The shuttle portion 5d has a shuttle shaft 12 and a forward-reverse clutch 13. The power output from the sub-transmission portion 5c is transmitted to the shuttle shaft 12 via gears and the like. The forward-reverse clutch 13 is constituted by, for example, a hydraulic clutch or the like. An oil passage is connected to the forward-reverse clutch 13, and a working valve 28 is connected to the oil passage. The working oil discharged from a hydraulic pump 33 is supplied to the working valve 28. The forward-reverse clutch 13 is switched to a connected state and a disconnected state according to the opening degree of the working valve 28. The working valve 28 is, for example, a two-position switching valve with a solenoid. The forward-reverse clutch 13 is switched to the connected state or the disconnected state by exciting or de-exciting the solenoid of the solenoid of the working valve 28.

[0042] The forward-reverse clutch 13 switches the rotation direction of the shuttle shaft 12 by being switched to the connected state or the disconnected state. The shuttle shaft 12 is connected to the rear wheel differential device 20R. The rear wheel differential device 20R rotatably supports a rear axle 21R on which the rear wheel 7R is mounted.

[0043] The PTO (Power Take Off) power transmission portion 5e has a PTO propeller shaft 14 and a PTO clutch 15. The PTO propeller shaft 14 is rotatably supported and is capable of transmitting the power from the propeller shaft 5a. The PTO propeller shaft 14 is connected to a PTO shaft 16 via gears and the like.

[0044] The PTO clutch 15 is constituted by a hydraulic clutch, for example. An oil passage is connected to the PTO clutch 15, and a work valve 27 is connected to the oil passage. Work oil discharged from a hydraulic pump 33 is supplied to the work valve 27. The PTO clutch 15 is switched to a connected state and a disconnected state in accordance with the opening degree of the work valve 27. The work valve 27 is a two-position switching valve with a solenoid, for example. By energizing or de-energizing the solenoid of the solenoid of the work valve 27, the PTO clutch 15 is switched to the connected state or the disconnected state.

[0045] The PTO clutch 15 is switched to a state in which the power of the propeller shaft 5a is transmitted to the PTO propeller shaft 14 and a state in which the power of the propeller shaft 5a is not transmitted to the PTO propeller shaft 14 by being switched to the connected state or the disconnected state. The power of the power machine 4 is transmitted to the PTO shaft 16 via the propeller shaft 5a, the PTO clutch 15, and the PTO propeller shaft 14, so that the PTO shaft 16 is rotationally driven. The lift device 8 and the work device 2 are coupled to the PTO shaft 16. The driving force of the PTO shaft 16 is transmitted to the lift device 8 and the work device 2, whereby the lift device 8 and the work device 2 are operated.

[0046] The front transmission section 5f has a first clutch 17 and a second clutch 18. The first clutch 17 and the second clutch 18 can transmit the power from the propeller shaft 5a, for example, to transmit the power of the shuttle shaft 12 via a gear 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 a front transmission shaft 22. Specifically, the front transmission shaft 22 is connected to a front wheel differential 20F that supports the front axle 21F on which the front wheel 7F is mounted so as to be rotatable.

[0047] The first clutch 17 and the second clutch 18 are constituted by hydraulic clutches, for example. An oil passage is connected to the first clutch 17, and a work valve 25 is connected to the oil passage. Work oil discharged from the hydraulic pump 33 is supplied to the work valve 25. The first clutch 17 is switched to a connected state and a disconnected state in accordance with the opening degree of the work valve 25. An oil passage is connected to the second clutch 18, and a work valve 26 is connected to the oil passage. Work oil discharged from the hydraulic pump 33 is supplied to the work valve 26. The second clutch 18 is switched to a connected state and a disconnected state in accordance with the opening degree of the work valve 26. The work valves 25, 26 are two-position switching valves with solenoids, for example. By energizing or de-energizing the solenoids of the solenoids of the respective work valves 25, 26, the corresponding clutches 17, 18 are switched to the connected state or the disconnected state.

[0048] In a case where the first clutch 17 is in the disengaged state and the second clutch 18 is in the engaged state, the power of the shuttle shaft 12 is transmitted to the front wheels 7F through the second clutch 18. Thereby, the front wheels 7F and the rear wheels 7R are driven, and the rotational speeds of the front wheels 7F and the rear wheels 7R are substantially the same (4WD equal speed state). On the other hand, in a case where the first clutch 17 is in the engaged state and the second clutch 18 is in the disengaged state, the front wheels 7F and the rear wheels 7R are driven, but the rotational speed of the front wheels 7F becomes faster than that of the rear wheels 7R (4WD speed-up state). In addition, in a case where the first clutch 17 and the second clutch 18 are in the disengaged state, the power of the shuttle shaft 12 is not transmitted to the front wheels 7F, and thus, a two-wheel drive (2WD) in which only the rear wheels 7R are driven is established.

[0049] That is, the power of the power machine 4 is transmitted to the shuttle shaft 12 via the propeller shaft 5a, the main transmission 5b, the sub-transmission 5c, and the forward / reverse clutch 13, and the shuttle shaft 12 rotates in the forward direction or the reverse direction, whereby the rear differential 20R is driven, and the rear axle 21R and the rear wheels 7R rotate in the forward direction or the reverse direction. In addition, the power of the power machine 4 is transmitted from the shuttle shaft 12 to the front transmission shaft 22 via the clutches 17, 18, and the front transmission shaft 22 rotates in the forward direction or the reverse direction, whereby the front differential 20F is driven, and the front axle 21F and the front wheels 7F rotate in the forward direction or the reverse direction. Thereby, the vehicle body 3, that is, the work vehicle 1 advances or retreats.

[0050] The lifting device 8 has a lift arm 8a, a lower link 8b, an upper link 8c, a lift rod (omitted from the drawing), and a lift cylinder 8e. The front end portion of the lift arm 8a is swingably supported upward or downward at the rear upper portion of the housing (transmission case) of the transmission 5. The lift arm 8a is swung (lifted and lowered) by the drive of the lift cylinder 8e. The lift cylinder 8e is constituted by a hydraulic cylinder. The lift cylinder 8e is connected to the hydraulic pump 33 via a control valve 29. The control valve 29 is an electromagnetic valve or the like, and causes the lift cylinder 8e to extend or retract.

[0051] The front end portion of the lower link 8b is swingably supported upward or downward at the rear lower portion of the transmission 5. The front end portion of the upper link 8c is swingably supported upward or downward at the rear portion of the transmission 5 at a position higher than that of the lower link 8b. The lift arm 8a and the lower link 8b are linked by the lift rod. The work device 2 is linked at the rear portion of the lower link 8b and the rear portion of the upper link 8c. When the lift cylinder 8e is driven (extended or retracted), the lift arm 8a is lifted and lowered, and the lower link 8b linked to the lift arm 8a via the lift rod 8d is lifted and lowered. Thereby, the work device 2 swings (lifts and lowers) upward or downward with the front portion of the lower link 8b as a fulcrum. Note that the work vehicle 1 has an automatic lifting device that lifts the lifting device 8 with the vehicle body 3 in the retreat state as a working condition. In the present embodiment, the automatic lifting device includes the lift cylinder 8e and the control valve 29.

[0052] 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, QZSS, Galileo, and Beidou. That is, the positioning device 40 receives a satellite signal (position of the positioning satellite, time of transmission, correction information, and the like) 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 signal receiving device 41 and an inertial measurement device (IMU: Inertial Measurement Unit) 42. The signal receiving device 41 has an antenna or the like, and receives a satellite signal transmitted from the positioning satellite. The signal receiving device 41 is mounted to the safety frame 6 Figure 12 ), for example.

[0053] The inertial measurement device 42 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. Based on the detection results of the inertial measurement device 42, a roll angle, a pitch angle, a yaw angle, and the like of the vehicle body 3 can be detected.

[0054] The steering device 11 is a device that can perform manual steering in which the vehicle body 3 is steered by the driver seated on the driver's seat 10 operating the steering wheel (steering wheel) 30, and automatic steering in which the vehicle body 3 is automatically steered without depending on the operation of the driver.

[0055] The steering device 11 has the steering wheel 30, a steering shaft (rotating shaft) 31 that supports the steering wheel 30 so as to be rotatable, and an assist mechanism (power steering device) 32. The assist mechanism 32 assists the rotation of the steering shaft 31 and the steering wheel 30 by hydraulic pressure or the like. The assist mechanism 32 includes a control valve 34 to which working oil discharged from a hydraulic pump 33 is supplied, and a steering cylinder 35 that operates 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 is switched in correspondence with the steering direction (rotating 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 wheel 7F.

[0056] By the driver rotating the steering wheel 30 to one direction or the other direction, the switching position and the opening degree of the control valve 34 are switched in correspondence with the rotating direction of the steering wheel 30, and in accordance with the switching position and the opening degree of the control valve 34, the steering cylinder 35 is extended or contracted to the left or right, and the steering direction of the front wheel 7F can be changed. That is, by the manual steering of the steering wheel 30, the traveling direction of the vehicle body 3 can be changed left or right.

[0057] Further, the turning device 11 has an automatic turning mechanism 37. The automatic turning mechanism 37 is a mechanism that performs automatic turning of the vehicle body 3, and automatically turns the vehicle body 3 based on the position of the vehicle body 3 detected by the positioning device 40. The automatic turning mechanism 37 is provided with a turning motor 38 and a gear mechanism 39. The turning motor 38 is a motor that can control the direction of rotation, the speed of rotation, the angle of rotation, and the like based on the position of the vehicle body. The gear mechanism 39 includes a gear provided to the turning shaft 31 and rotating integrally with the turning shaft 31, and a gear provided to a rotating shaft of the turning motor 38 and rotating integrally with the rotating shaft.

[0058] By rotating the rotating shaft of the turning motor 38 in the positive direction, the turning shaft 31 is automatically rotated (turned) in the positive direction via the gear mechanism 39, and it is possible to turn the front wheels 7F in one of the left and right directions. Further, when the rotating shaft of the turning motor 38 is rotated in the reverse direction, the turning shaft 31 is automatically rotated in the reverse direction via the gear mechanism 39, and it is possible to turn the front wheels 7F in the other of the left and right directions.

[0059] The control device 60 is constituted by a CPU and a memory, and the like. The control device 60 controls the operation of each part of the work vehicle 1. The display device 45 is provided to an operation table 9F (operation member) located in front of the driver's seat 10. Figure 12 ) of the work vehicle 1, and various other information related to the work vehicle 1. Further, the display device 45 is also a notification device that performs notification related to the automatic turning of the vehicle body 3.

[0060] The switches 50 to 54 are automatic turning operation switches (operation members) operated by the driver of the work vehicle 1. Among them, the mode switch 50 is a switch for instructing switching of the set mode of the setting of the automatic turning in the direction. The set mode is a mode in which various settings related to the automatic turning are performed before the automatic turning is started. For example, the setting of the start point and the end point of the travel reference line described later, and the like can be performed in the set mode.

[0061] The setting switch 51 is a switch for instructing the setting of the travel reference line for executing the automatic turning when the set mode is valid. The turning switches 52 and 54 are switches for instructing the start or stop of the automatic turning of the vehicle body 3 based on the travel reference line. The correction switch 53 is a switch for instructing the correction of the position of the vehicle body 3 detected by the positioning device 40. That is, the position of the vehicle body 3 calculated from the satellite signal (the position of the positioning satellite, the time of transmission, correction information, and the like) and the measured information (acceleration, angular velocity) measured by the inertial measurement device 42 can be corrected by operating the correction switch 53. The control device 60 detects the operation state of each switch 50 to 54.

[0062] The PTO shift lever 24 is an operating component for the PTO operated by the driver of the work vehicle 1. Figure 2 This is a detailed drawing of the PTO shift lever 24. The PTO shift lever 24 is a lever operated to switch the rotation direction of the PTO shaft 16 or change the speed of the PTO shaft 16. The PTO shift lever 24 is located on the control panel 9L on the left side of the driver's seat 10 (see reference). Figure 12 , Figure 7 The PTO shift lever 24 is operated by swinging from... Figure 2 The neutral position Qn shown can be switched to any one of the following driving positions: forward first position Q1, forward second position Q2, forward third position Q3, and reverse position Qb.

[0063] When the PTO shift lever 24 is inactive, it is in the neutral position Qn. The movable terminal 24f, which is linked to the lever 24, is connected to the fixed terminal 24a. A signal is input from the power supply to the input port 60a of the control device 60 via the terminals 24f and 24a and the input line 62a. Thus, the control device 60 detects that the PTO shift lever 24 is in the neutral position Qn. At this time, the PTO shaft 16 is in a stopped state.

[0064] When the PTO shift lever 24 is swung forward A1 in a first-stage operation to switch its position to the first forward position Q1, the movable terminal 24f connects to the fixed terminal 24b, and a signal is input from the power supply to the input port 60b of the control device 60 via terminals 24f and 24b and input line 62b. Furthermore, when the PTO shift lever 24 is swung forward A1 in a second-stage operation to switch its position to the second forward position Q2, the movable terminal 24f connects to the fixed terminal 24c, and a signal is input from the power supply to the input port 60c of the control device 60 via terminals 24f and 24c and input line 62c. Finally, when the PTO shift lever 24 is swung forward A1 in a third-stage operation to switch its position to the third forward position Q3, the movable terminal 24f connects to the fixed terminal 24d, and a signal is input from the power supply to the input port 60d of the control device 60 via terminals 24f and 24d and input line 62d.

[0065] The control device 60 detects the case where the PTO shift lever 24 is switched to the forward rotation first position Ql, the second position Q2, or the third position Q3 when inputting a signal to each of the input ports 60b, 60c, 60d. When the PTO shift lever 24 is switched to the forward rotation first position Ql, the PTO shaft 16 is rotationally driven in the forward direction at a prescribed first rotational speed by the operation of the transmission 5. In addition, when the PTO shift lever 24 is switched to the forward rotation second position Q2, the PTO shaft 16 is rotationally driven in the forward direction at a prescribed second rotational speed that is greater than the first rotational speed by the operation of the transmission 5. Furthermore, when the PTO shift lever 24 is switched to the forward rotation third position Q3, the PTO shaft 16 is rotationally driven in the forward direction at a prescribed third rotational speed that is greater than the second rotational speed by the operation of the transmission 5.

[0066] In addition, when the PTO shift lever 24L is swung rearward A2 to switch the position of the lever 24 to the reverse rotation position Qb, the movable terminal 24f is connected to the fixed terminal 24e, and a signal is input from the power supply to the input port 60e of the control device 60 via the terminals 24f, 24e and the input line 62e. As a result, the control device 60 detects the case where the PTO shift lever 24 is located at the reverse rotation position Qb. At this time, the PTO shaft 16 is rotationally driven in the reverse direction at a prescribed rotational speed by the operation of the transmission 5.

[0067] Next, automatic steering of the work vehicle 1 will be described. Figure 3 is a view for explaining automatic steering of the work vehicle 1. Before automatic steering is performed, first, a travel reference line Ll for performing automatic steering is set. After the travel reference line Ll is set, automatic steering can be performed by performing setting of a travel intended line L2 that is parallel to the travel reference line Ll. In automatic steering, steering of the travel direction of the vehicle body 3 of the work vehicle 1 is automatically performed so that the position of the vehicle body 3 measured by the positioning device 40 coincides with the travel intended line L2.

[0068] Specifically, before automatic steering is performed, the driver drives the work vehicle 1 to move the work vehicle 1 to a prescribed position within a field (Sl), and operates the mode switch 50 at the prescribed position. As a result, the control device 60 shifts to the setting mode. Next, when the driver performs a start point registration operation by the setting switch 51 (S2), the control device 60 sets the position of the vehicle body 3 measured by the positioning device 40 at that time as the start point P10 of the travel reference line Ll (S3).

[0069] Next, the driver manually steers the work vehicle 1 from the starting point P10 of the driving reference line L1 (S4) and stops it at the designated position. Then, when the driver performs the endpoint registration operation via the setting switch 51 (S5), the control device 60 sets the position of the vehicle body 3, measured by the positioning device 40 at this time, as the endpoint P11 of the driving reference line L1 (S6). Thus, the straight line connecting the starting point P10 and the endpoint P11 is set as the driving reference line L1.

[0070] Next, the driver moves the work vehicle 1 to a location different from the location where the driving baseline L1 was set (S7), via the turn switch 52 (or turn switch 54). Figure 1 The start operation is initiated (S8). Then, the control device 60 sets a straight line parallel to the driving reference line L1, i.e., the predetermined driving line L2 (S9). Afterwards, the control device 60 activates the automatic steering mechanism 37, initiating automatic steering, and the driver operates the driving control components installed on the vehicle body 3. Figure 1 Accelerator pedal 182, brake pedal 183, Figure 6 (e.g., the shuttle rod 181), thereby causing the work vehicle 1 to travel along the predetermined travel line L2. The travel reference line L1 and the predetermined travel line L2 are displayed by the display device 45, which allows the driver to visually confirm them.

[0071] For example, when the vehicle body 3 is positioned to the left of the predetermined driving line L2, the control device 60 activates the automatic steering mechanism 37, turning the front wheels 7F to the right. Conversely, when the vehicle body 3 is positioned to the right of the predetermined driving line L2, the control device 60 activates the automatic steering mechanism 37, turning the front wheels 7F to the left. During automatic steering, the driver can change the speed of the work vehicle 1 by altering the amount of operation of the accelerator pedal 182, etc., or by changing the gear of the transmission device 5.

[0072] Furthermore, after automatic steering begins, when the driver stops the automatic steering at any point using the steering switch 52, the control device 60 stops (ends) the automatic steering. That is, the end point of the predetermined driving line L2 is set by stopping the automatic steering based on the stop operation of the steering switch 52. In other words, the length from the start point to the end point of the predetermined driving line L2 can be set to be longer or shorter than the driving reference line L1. In other words, the length of the predetermined driving line L2 is not related to the length of the driving reference line L1, allowing the driver to travel a longer distance than the driving reference line L1 while automatically steering along the predetermined driving line L2.

[0073] During the operation of the work vehicle 1 based on automatic steering, the position of the vehicle body 3 detected by the positioning device 40 sometimes deviates from the actual position of the vehicle body 3. This position deviation of the vehicle body 3 can be corrected by the driver operating the correction switch 53.

[0074] Next, the relationship between the operation of the correction switch 53 at the time of automatic steering and the behavior (traveling trajectory) of the work vehicle 1 will be described. Figure 4 is a view showing an example of the behavior of the work vehicle 1 in straight running based on automatic steering. In Figure 4 , for example, for a certain period of time after the work vehicle 1 starts automatic steering, the position of the actual vehicle body 3 (actual position) W2 coincides with the position of the vehicle body 3 (calculated vehicle body position) Wl detected by the positioning device 40, and the actual position W2 coincides with the traveling predetermined line L2. In this case, the work vehicle 1 travels along the traveling predetermined line L2. That is, in the section Pl in which the positioning of the positioning device 40 has no error and the calculated vehicle body position Wl coincides with the actual position W2, the work vehicle 1 travels along the traveling predetermined line L2.

[0075] Note that, in the case where the positioning of the positioning device 40 has no error and no correction is performed, the calculated vehicle body position Wl and the vehicle body position (corrected vehicle body position) W3 corrected by the correction switch 53 are the same value. The corrected vehicle body position W3 is found by subtracting the correction amount input by the correction switch 53 from the calculated vehicle body position Wl (corrected vehicle body position W3 = calculated vehicle body position Wl - correction amount).

[0076] For example, in the vicinity of the position P20, Figure 4 , although the actual position W2 is not offset with respect to the traveling predetermined line L2, an error occurs in the positioning of the positioning device 40 due to various influences, the calculated vehicle body position Wl detected by the positioning device 40 is offset to the right with respect to the traveling predetermined line L2 (actual position W2), and this offset amount W4 is maintained. In this case, the control device 60 determines that an offset has occurred between the calculated vehicle body position Wl and the traveling predetermined line L2, and turns the vehicle body 3 to the left to eliminate the offset amount W4 between the calculated vehicle body position Wl and the traveling predetermined line L2. As a result, the actual position W2 of the vehicle body 3 is displaced in such a manner as to deviate to the left from the traveling predetermined line L2.

[0077] After that, the driver notices that the position of the vehicle body 3 is offset to the left from the traveling predetermined line L2, operates the correction switch 53 at the position P21, and inputs a correction amount that brings the calculated vehicle body position Wl close to the actual position W2. As a result, the calculated vehicle body position Wl is added by this correction amount, and the corrected vehicle body position W3 substantially coincides with the actual position W2. That is, by inputting the above-described correction amount by the correction switch 53, it is possible to correct the position of the vehicle body 3 detected by the positioning device 40 in the direction to eliminate the offset amount W4 that occurs in the vicinity of the position P20.

[0078] Note that, as Figure 4As shown, after the position of the vehicle body 3 is corrected (position P21), in the case where the actual position W2 is offset to the left from the travel predetermined line L2, the vehicle body 3 is turned to the right by automatic steering, whereby the actual position W2 of the vehicle body 3 is made to follow the travel predetermined line L2.

[0079] Further, in the above Figure 3 , the case where the work vehicle 1 performs automatic steering while advancing is shown, but the work vehicle 1 can also perform automatic steering while retreating.

[0080] Figure 5 is a diagram showing the state of automatic steering when the work vehicle 1 is advancing and when the work vehicle 1 is retreating. For example, in the field H1, automatic steering is performed, and each time a start operation is performed by either one of the steering switches 52, 54, the control device 60 sets a straight line portion SLn (n = 1, 2, 3,...) of a plurality of travel predetermined lines L2 that are parallel to the reference travel line L1. For example, when a start operation is performed by the steering switch 52 at a start position ST1 to indicate the start of automatic steering, the first straight line portion SL1 is set. Next, the control device 60 controls the transmission mechanism 5 and the automatic steering mechanism 37, whereby automatic steering is performed while the vehicle body 3 is made to advance along the straight line portion SL1. Further, when a stop operation is performed by the steering switch 52 at an end position EN1 to indicate the stop of automatic steering, the control device 60 controls the automatic steering mechanism 37, whereby automatic steering during advancement of the vehicle body 3 along the straight line portion SL1 is ended (stopped).

[0081] After that, for example, in order to perform work using the work device 2 mounted to the work vehicle 1, after the automatic steering during advancement at the first straight line portion SL1 is ended, the driver wants to perform automatic steering while making the vehicle body 3 retreat without turning the work vehicle 1.

[0082] In this case, for example, when a start operation is performed by the steering switch 54 at a start position ST2 to indicate the start of automatic steering, the control device 60 sets the second straight line portion SL2. Next, the control device 60 controls the transmission mechanism 5 and the automatic steering mechanism 37, whereby automatic steering is performed while the vehicle body 3 is made to retreat along the straight line portion SL2. Specifically, when a start operation is performed by the steering switch 54 to start automatic steering, in order to make the vehicle body 3 retreat along the straight line portion SL2, the control device 60 controls the driving of the steering motor 38 of the automatic steering mechanism 37 to rotate the steering shaft 31, thereby steering the front wheels 7F. Next, when a stop operation is performed by the steering switch 54 at an end position EN2 to indicate the stop of automatic steering, the control device 60 controls the automatic steering mechanism 37, whereby automatic steering during retreat of the vehicle body 3 along the straight line portion SL2 is ended.

[0083] Next, the operation platform 9F will be described. Figure 6 is a view showing a state of the operation platform 9F located in front of the driver's seat 10 as viewed from the driver's seat 10 side. The operation platform 9F is provided with a steering wheel 30 and a steering shaft 31 coupled to the steering wheel 30. The outer periphery of the steering shaft 31 is covered by a steering column 180. The outer periphery of the steering column 180 is covered by a cover 177. The cover 177 includes a panel cover 178 and a column cover 179.

[0084] The panel cover 178 supports a display device 45. A support portion 178e that supports the display device 45 is provided on an 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. A mounting surface 178f of the upper plate portion 178a is provided behind the support portion 178e and below the steering wheel 30. The support portion 178e is continuous with the mounting surface 178f. The support portion 178e is located at a front portion of the upper plate portion 178a, and the mounting surface 178f is located at a rear portion of the upper plate portion 178a. A mode switch 50 and a correction switch 53 are provided on the mounting surface 178f. The mode switch 50 and the correction switch 53 are arranged around the steering shaft 31.

[0085] A shuttle lever 181 protrudes from a 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 to the front A1 or the rear A2. In detail, by operating (swinging) the shuttle lever 181 to the front A1 (upper side in FIG. 6), the forward / reverse clutch 13 becomes a state of outputting forward power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the front A1. In addition, by operating the shuttle lever 181 to the rear A2 (lower side in FIG. 6), the forward / reverse clutch 13 becomes a state of outputting reverse power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the rear A2. When the shuttle lever 181 is located at a neutral position, no power is output to the traveling device 7. Figure 6 Figure 6 The column cover 179 is arranged 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 square cylindrical shape and protrudes upward from the mounting surface 178f of the panel cover 178. That is, the mounting surface 178f is provided around the column cover 179. Therefore, the mode switch 50 and the correction switch 53 mounted to the mounting surface 178f are arranged around the column cover 179.

[0086] The mode switch 50 is arranged below the left of the steering shaft 31. The mode switch 50 is configured by a push-button type switch. The mode switch 50 is electrically connected to the control device 60 through an electric wiring 70 (shown in FIG. 1) arranged inside the operation platform 9F.

[0087] The mode switch 50 is arranged below the left of the steering shaft 31. The mode switch 50 is configured by a push-button type switch. The mode switch 50 is electrically connected to the control device 60 through an electric wiring 70 (shown in FIG. 1) arranged inside the operation platform 9F. Figure 1

[0088] ​​The correction switch 53 is located on the lower right side of the steering shaft 31. The correction switch 53 is connected via electrical wiring 73 located inside the control panel 9F. Figure 1 It is electrically connected to the control device 60. The correction switch 53 has a pressable left correction button 53L and a right correction button 53R. By pressing the left correction button 53L, a left correction amount to correct the position of the vehicle body 3 to the left is input to the control device 60. Similarly, by pressing the right correction button 53R, a right correction amount to correct the position of the vehicle body 3 to the right is input to the control device 60.

[0089] By increasing the number of times each correction key 53L and 53R is pressed, the left and right correction amounts can be increased. Each correction amount is calculated by multiplying the number of times each correction key 53L and 53R is pressed by a predetermined unit amount (correction amount = number of presses × unit amount). That is, each time each correction key 53L and 53R is pressed, the correction amount increases by a unit amount (e.g., a few centimeters or tens of centimeters). The control device 60 detects the number of times the correction switch 53 is pressed and calculates the correction amount based on the number of presses.

[0090] The automatic steering lever 56 is positioned to the left of the steering shaft 31, protruding to the left. The automatic steering lever 56 can swing upwards, downwards, forwards, and backwards from a neutral position, using its base end located on the side of the steering shaft 31 as a fulcrum. The base end of the automatic steering lever 56 is located inside the pillar cover 179. The aforementioned setting switch 51 and steering switch 52 are located inside the pillar cover 179. Figure 1 (Detailed illustrations omitted). The setting switch 51 and the direction switch 52 are connected via electrical wiring 71, 72 arranged inside the control panel 9F. Figure 1 Each of them is electrically connected to the control device 60.

[0091] With the mode switch 50 activated and the setting mode enabled, swinging the automatic steering lever 56 from the neutral position to the rearward position activates the setting switch 51, indicating that the position of the vehicle body 3 detected by the positioning device 40 is set as the starting point P10 of the driving reference line L1. Furthermore, swinging the automatic steering lever 56 from the neutral position to the forward position activates the setting switch 51, indicating that the position of the vehicle body 3 detected by the positioning device 40 is set as the ending point P11 of the driving reference line L1, and this is also input to the control device 60.

[0092] Subsequently, by swinging the automatic steering lever 56 downward from the neutral position, the steering switch 52 is activated, and an automatic steering start indication is input to the control device 60. Furthermore, by swinging the automatic steering lever 56 upward from the neutral position, the steering switch 52 is activated, and an automatic steering stop indication is input to the control device 60.

[0093] The mode switch 50, correction switch 53, and automatic steering lever 56 are centrally located around the steering shaft 31. Therefore, the driver can easily see the positions of the switches 50, 53, and lever 56. Furthermore, the driver can operate the switches 50, 53, and lever 56 without changing their posture while seated in the driver's seat 10. As a result, the operability of the automatic steering switches 50, 51, 52, and 53 is improved when the vehicle body 3 is moving forward while automatically steering, and accidental operation of the switches 50, 51, 52, and 53 is prevented. Switches 50 to 53 are located on the first operating section of the control panel 9F in front of the driver's seat 10.

[0094] It should be noted that the configuration of switches 50-53 and lever 56 is not limited to the above configuration and can be any configuration. Alternatively, the switch 51 and turn switch 52 can be operated via different levers, buttons, or other operating knobs.

[0095] Figure 7 This is a perspective view of the work vehicle 1 from the front. On the control panel 9L located to the left of the driver's seat 10, there is a PTO shift lever 24 for operating the aforementioned PTO shaft 16. A safety frame 6 is located A2 behind the driver's seat 10. The safety frame 6 consists of a pair of left and right support pillars 6L and 6R and a beam 6b. The support pillars 6L, 6R, and beam 6b are made of steel. The support pillar 6L is erected on the left rear of the vehicle body 3, and the support pillar 6R is erected on the right rear of the vehicle body 3. The beam 6b connects the upper ends of the support pillars 6L and 6R to each other.

[0096] A switch box 19 is mounted on the front surface of the support column 6L located on the left side. The mounting surface 19b of the switch box 19, which contacts the support column 6L, is... Figure 7 The back of switch box 19, facing rearward (A2), will be described later. Figure 8 A magnet (not shown) is fixed to the switch box 19. Using the magnetic force of this magnet, the switch box 19 can be mounted and dismounted relative to the support column 6L.

[0097] A turn signal switch 54 is provided on the front surface 19f facing forward A1, other than the mounting surface 19b of the switch box 19. The turn signal switch 54 is a second operating unit for automatic steering that can be installed behind the driver's seat 10, and has the same function as the turn signal switch 52 included in the first operating unit provided on the control panel 9F.

[0098] The steering switch 54 has an on-key 54a and an off-key 54b. Inside the switch box 19, contacts of the steering switch 54, electric wiring, and the like are provided. The switch box 19 is a frame of the second operation section. The steering switch 54 is electrically connected to the control device 60 via the electric wiring 74 (see also FIG. 6) arranged from the switch box 19 located at the rear of the driver's seat 10 to the operation table 9F through the inside of the left side portion of the vehicle body 3. Figure 1 ) with the control device 60.

[0099] By pressing operation of the on-key 54a, the steering switch 54 becomes a state in which a start operation is performed, and a start instruction of automatic steering is input to the control device 60. By pressing operation of the off-key 54b, the steering switch 54 becomes a state in which a stop operation is performed, and a stop instruction of automatic steering is input to the control device 60.

[0100] When the work vehicle 1 performs automatic steering while backing up, the driver seated on the driver's seat 10 turns his head to the rear A2 in order to confirm safety of the rear A2. In this turning posture, the driver can visually recognize the on-key 54a and the off-key 54b. Therefore, the driver starts automatic operation at the time of backing up by pressing operation of the on-key 54a, and stops automatic steering at the time of backing up by pressing operation of the off-key 54b. That is, the steering switch 54 is an operation section for automatic steering at the time of backing up, which is operated in order to start and stop automatic steering at the time of backing up of the vehicle body 3.

[0101] However, the steering switches 52, 54 are usable (effective) at the time of forward travel and at the time of backing up of the vehicle body 3. That is, by performing start operation or stop operation of either one of the steering switches 52, 54, the control device 60 starts or stops automatic steering, regardless of the time of forward travel or the time of backing up of the vehicle body 3. However, when the control device 60 starts automatic steering in a case where the steering switch of one of the steering switches 52, 54 is started to be operated, the control device 60 inactivates the other steering switch before stopping (ending) automatic steering in a case where the steering switch of the one is stopped to be operated.

[0102] Specifically, for example, when the control device 60 starts automatic steering at the time of backing up in a case where the steering switch 54 located at the rear A2 is started to be operated, the control device 60 inactivates the steering switch 52, that is, does not accept operation of the steering switch 52, before stopping automatic steering in a case where the steering switch 54 is stopped to be operated. Also, for example, when the control device 60 starts automatic steering at the time of forward travel in a case where the steering switch 52 located at the front Al is started to be operated, the control device 60 inactivates the steering switch 54, that is, does not accept operation of the steering switch 54, before stopping automatic steering in a case where the steering switch 52 is stopped to be operated.

[0103] Figure 8is a perspective view of the switch box 19 and the pillar 6L viewed from the rear. The switch box 19 provided with the steering switch 54 is prevented from falling off the pillar 6L by a falling prevention mechanism 57. The falling prevention mechanism 57 is composed of a wire 58 and a snap ring 59. The wire 58 penetrates the upper portion of the switch box 19 left and right and surrounds the pillar 6L. Through holes 58a, 58b are formed in both end portions of the wire 58 located at the rear of the pillar 6L. The snap ring 59 is disposed at the rear of the pillar 6L and penetrates the through holes 58a, 58b of the wire 58. Thus, the switch box 19 is restrained by the wire 58 and the snap ring 59 so as not to move away from the vicinity of the pillar 6L.

[0104] In Figure 7 and Figure 8 , the switch box 19 provided with the steering switch 54 is mounted to the front surface of the pillar 6L on the left side of the safety frame 6, but the switch box 19 can be mounted to the pillar 6R on the right side. As shown in Figure 7 , the electric wiring 74 of the switch box 19 extends to the outside (upper side) of the vehicle body 3 from the rear of the driver's seat 10, and therefore, the electric wiring 74 does not interfere with the driving operation. In addition, the electric wiring 74 has a length that enables the switch box 19 to be mounted to either one of the pillars 6L, 6R from the rear of the driver's seat 10, and therefore, the replacement operation of the switch box 19 from one of the pillars 6L, 6R to the other can be easily performed. In addition, the switch box 19 can also be mounted to any side surface of either one of the pillars 6L, 6R, any side surface of the beam 6b, and any position of the vehicle body 3. Note that, in view of the operability of the steering switch 54, it is not recommended to mount the switch box 19 to the beam 6b Figure 7 ) located at a position higher than the driver seated on the driver's seat 10.

[0105] Next, the control of automatic steering in conjunction with the PTO shaft 16 of the work vehicle 1 will be described. Figure 9 is a flowchart showing the operation of the work vehicle 1. Figure 9 Each process of

[0106] First, the control device 60 detects the states of the PTO shift lever 24 and the PTO shaft 16 (T1). The state of the PTO shaft 16 is detected, for example, based on the opening degree of the work valve 27. Alternatively, a sensor that detects the rotational state of the PTO shaft 16 can be provided, and the control device 60 detects the state of the PTO shaft 16 based on the output signal from the sensor.

[0107] If the PTO shift lever 24 is in the neutral position Qn and the PTO shaft 16 is in the stopped state (T2: YES), the control device 60 permits automatic steering at the time of backing up (T3). Note that automatic steering at the time of going forward is always permitted. Also, after the mode switch 50, the setting switch 51 are operated to set the travel reference line Ll, if there is a start operation in any one of the steering switches 52, 54 (T4: YES), the control device 60 controls the automatic steering mechanism 37 to start automatic steering (T5). Thus, in the work vehicle 1, automatic steering at the time of going forward or automatic steering at the time of backing up is performed in accordance with the direction of travel of the vehicle body 3.

[0108] In addition, the control device 60 notifies the driver of the work vehicle 1 of the state of automatic steering being performed, guidance related to automatic steering, and the like by causing the display device 45 to display automatic steering information (T6). At this time, it is also possible to display, for example, the travel reference line Ll, the travel intended line L2, the position of the work vehicle 1, and the like in the field Hl as shown in the drawing by the display device 45. Alternatively, it is also possible to notify the state of automatic steering and guidance related to automatic steering in an audible or visual manner by means of a buzzer, a speaker, an illumination device, or the like provided in the work vehicle 1. Figure 5

[0109] In addition, the control device 60 invalidates the steering switch that is not being operated (T7). Thus, for example, even if the steering switch that is not being operated is mistakenly operated, automatic steering is not stopped or restarted in accordance with the mistaken operation.

[0110] After that, when the same steering switch for which a start operation was detected in the process T4 has a stop operation (T8: YES), the control device 60 controls the automatic steering mechanism 37 to stop automatic steering (T9). In addition, the control device 60 also stops notification based on the automatic steering information of the display device 45 (T10), and cancels invalidation of the steering switch that is not being operated (Tll).

[0111] On the other hand, in the case where the PTO shift lever 24 is not in the neutral position Qn or in the case where the PTO shaft 16 is in the driven state (T2: NO), the control device 60 prohibits automatic steering at the time of backing up (T12). At this time, automatic steering at the time of going forward is not prohibited.

[0112] Also, when there is a start operation in any one of the steering switches 52, 54 (T13: YES), the control device 60 controls the automatic steering mechanism 37 based on the shuttle lever 181 ( Figure 6 ​The system detects the operating status of the shuttle lever 181 and the rotation status of the wheels 7F and 7R to determine the driving direction of the vehicle body 3. It should be noted that sensors can also be installed to detect the operating status of the shuttle lever 181 and the rotation status of the wheels 7F and 7R. If the driving direction of the vehicle body 3 is forward A1 (T14: No), the control device 60 controls the automatic steering mechanism 37 to begin automatic steering for forward movement (T5). Then, the control device 60 executes processing after T6.

[0113] Furthermore, if the direction of travel of the vehicle body 3 is rearward A2 (T14: Yes), the control device 60 does not initiate automatic steering when reversing, but instead displays a message on the display device 45 indicating that automatic steering is prohibited when reversing, thereby informing the driver (T15). Additionally, the control device 60 informs the driver by displaying a prompt on the display device 45 to switch the PTO shift lever 24 to the neutral position Qn (T16).

[0114] The notifications based on the display device 45 during processes T15 and T16 can continue until the PTO shift lever 24 is switched to the neutral position Qn and the PTO shaft 16 comes to a stop, or they can only last for a certain period of time. Alternatively, during processes T15 and T16, the automatic steering being disabled during reversing and the guidance for switching the PTO shift lever 24 to the neutral position Qn can be provided audibly or visually using a buzzer, speaker, or lighting device provided by the work vehicle 1. That is, a notification device other than the display device 45 capable of providing visual, auditory, or tactile notifications can also be used. Furthermore, it can replace process T16, for example, by providing guidance to stop the PTO shaft 16.

[0115] Furthermore, in the above embodiment, when the PTO shift lever 24 is not in the neutral position Qn or when the PTO shaft 16 is in the driving state ( Figure 9 (T2: No), the control device 60 prohibits automatic steering when reversing, but it may also prohibit automatic steering when reversing based on whether the conditions of the PTO shift lever 24 and the PTO shaft 16 are appropriate.

[0116] Furthermore, in the above embodiment, when automatic steering begins as indicated by the operation of steering switches 52 and 54 and the vehicle body 3 reverses ( Figure 9the automatic turning is started by the operation of the turning switches 52, 54 and the vehicle body 3 is advancing (process T13: YES, process T14: NO), the prohibition of the automatic turning at the time of backing up and the switching guidance of the PTO shift lever 24 can also be informed by the display device 45. Note that in this case, in the case where the automatic turning is performed while backing up, it is preferable to inform the guidance to switch the PTO shift lever 24 to the neutral position Qn by the display device 45 or the like.

[0117] In addition, in the above-described embodiment, the PTO shift lever 24 is provided as the operation member that operates the driving of the PTO shaft 16, but in order to improve safety or the like, in addition to this lever 24, for example Figure 10 the PTO switch 23 as shown in FIG. 8 can also be provided.

[0118] Figure 10 is a detailed view of the PTO switch 23. The PTO switch 23 is a switch that is operated in order to instruct the driving and the stop of the PTO shaft 16. The PTO switch 23 is provided in an operable manner at, for example, the operation table 9L located on the left side of the driver's seat 10. The PTO switch 23 can be switched from the neutral position Qx to either one of the off position Qy and the on position (driving position) Qz.

[0119] In the unoperated state, the PTO switch 23 is located at the neutral position Qx, the movable terminal 23d of this switch 23 is connected to the fixed terminal 23a, and a signal is input from this switch 23 to the input port 60g of the control device 60 through the input line 61a. Due to this, the control device 60 detects the case where the PTO switch 23 is located at the neutral position Qx. At this time, the PTO shaft 16 is in the stopped state, and for example, even if the PTO shift lever 24 is switched to any one of the driving positions Q1, Q2, Q3, Qb, the PTO shaft 16 is not rotationally driven. Figure 2 ) the PTO shaft 16 is not rotationally driven.

[0120] When the PTO switch 23 is operated and switched to the on position Qz, the movable terminal 23g is connected to the fixed terminal 23c, and a signal is input from this switch 23 to the input port 60i of the control device 60 through the input line 61c. Due to this, the control device 60 detects the case where the PTO switch 23 is switched to the on position Qz. At this time, the PTO shaft 16 is able to be driven by the operation of the transmission 5. That is, by switching the PTO shift lever 24 to any one of the driving positions Q1, Q2, Q3, Qb, the PTO shaft 16 is rotationally driven in the forward direction or the reverse direction at a prescribed rotational speed.

[0121] Further, when the PTO switch 23 is operated to switch to the off position Qy, the movable terminal 23g is connected to the fixed terminal 23b, and a signal is input from the switch 23 to the input port 60h of the control device 60 through the input line 61b. Thus, the control device 60 detects the case where the PTO switch 23 is switched to the off position Qy. At this time, the PTO shaft 16 becomes a stopped state by the operation of the transmission 5.

[0122] As described above, the PTO shaft 16 can also be driven or stopped by the operation of the PTO switch 23. Therefore, instead of the position of the PTO shift lever 24, it is possible to permit or prohibit automatic steering at the time of backing up based on the position of the PTO switch 23. Specifically, for example, in the process Tl, instead of the PTO shift lever 24, the state of the PTO switch 23 is detected, and in the process T2, it is only necessary to confirm whether the PTO switch 23 is positioned at the neutral position Qx. The PTO shift lever 24 can also be constituted by a shift lever or a selection lever, or the like, which can be operated to swing forward and backward and left and right. Figure 9

[0123] Further, in the above embodiment, the switch box 19 (see FIG. 1) which can be installed at the rear A2 of the driver's seat 10 is provided with the steering switch 54 as the operation section for automatic steering, but is not limited thereto, and for example, as shown in FIG. 6, the correction switch 63 can also be provided in the switch box 19 as the operation section for automatic steering. The correction switch 63 has the same function as the correction switch 53 (see FIG. 2) provided in the operation platform 9F. Figure 7 Figure 11 Figure 6

[0124] Further, other operation sections for automatic steering such as the mode switch 50 and the setting switch 51 can also be provided in at least any one of the operation platforms 9F, 9L, 9R located at the front Al or the side of the driver's seat 10 and the switch box 19 which can be installed at the rear A2 of the driver's seat 10. Furthermore, the operation section for automatic steering can not only be a push switch, but also other types of switches such as a slide switch, a toggle switch, or the like, and can also be constituted by a key, a lever, or the like other than a switch.

[0125] The work vehicle 1 of the present embodiment has the following effects. ​​​​

[0126] The work vehicle 1 of the present embodiment is provided with: a vehicle body 3 that is capable of traveling forward and backward by either manual steering by a steering wheel 30 or automatic steering; a driver's seat 10 provided to the vehicle body 3; operation platforms 9F, 9L, 9R provided in front of or to the side of the driver's seat 10; first operation portions 50 to 53 for automatic steering provided to the operation platform 9F; and second operation portions 54, 63 for automatic steering capable of being installed to the rear of the driver's seat 10.

[0127] According to the above structure, in the work vehicle 1, when automatic steering is performed while the vehicle body 3 is being moved forward, the first operation portions 50 to 53 for automatic steering provided in front of or the like of the driver's seat 10 can be operated, and when automatic steering is performed while the vehicle body 3 is being moved backward, the second operation portions 54, 63 for automatic steering provided to the rear of the driver's seat 10 can be operated. Therefore, when automatic steering is performed, the driver does not need to move the operation portions 50 to 54, 63 for automatic steering according to the traveling direction of the vehicle body 3, and it is possible to reduce the situation in which the operation becomes complicated.

[0128] In addition, in the present embodiment, the first operation portions 50 to 53 and the second operation portions 54, 63 include steering switches 52, 54 that are operated in order to indicate the start and stop of automatic steering. Thereby, when automatic steering is performed while the vehicle body 3 is being moved forward, the steering switch 52 provided in front of the driver's seat 10 is operated, and when automatic steering is performed while the vehicle body 3 is being moved backward, the steering switch 54 provided to the rear of the driver's seat 10 is operated, and thus it is possible to start and stop automatic steering, and the operability is improved.

[0129] In addition, in the present embodiment, the work vehicle 1 is provided with a positioning device 40 capable of detecting the position of the vehicle body 3, and at least the first operation portions 50 to 53 among the first operation portions 50 to 53 and the second operation portions 54, 63 include: a setting switch 51 that is operated in order to indicate the setting of a traveling reference line L1 that becomes a reference for automatic steering; and a correction switch 53 that is operated in order to indicate the correction of the position of the vehicle body 3 detected by the positioning device 40. Thereby, after the traveling reference line L1 is set by operating the setting switch 51, it is possible to operate the steering switches 52, 54 corresponding to the traveling direction of the vehicle body 3 to perform automatic steering. In addition, when automatic steering is performed, it is possible to operate the correction switch 53 to correct the position of the vehicle body 3 detected by the positioning device 40, and to appropriately perform automatic steering.

[0130] In addition, in the present embodiment, the work vehicle 1 is provided with a positioning device 40 capable of detecting the position of the vehicle body 3, and at least the first operation portions 50 to 53 among the first operation portions 50 to 53 and the second operation portions 54, 63 include: a setting switch 51 that is operated in order to indicate the setting of a traveling reference line L1 that becomes a reference for automatic steering; and a correction switch 53 that is operated in order to indicate the correction of the position of the vehicle body 3 detected by the positioning device 40. Thereby, after the traveling reference line L1 is set by operating the setting switch 51, it is possible to operate the steering switches 52, 54 corresponding to the traveling direction of the vehicle body 3 to perform automatic steering. In addition, when automatic steering is performed, it is possible to operate the correction switch 53 to correct the position of the vehicle body 3 detected by the positioning device 40, and to appropriately perform automatic steering. Figure 11In the illustrated embodiment, the second operation section 54, 63 includes a correction switch 63 that is operated for instructing correction of the position of the vehicle body 3 detected by the positioning device 40. Thus, the correction switches 53, 63 corresponding to the travel direction of the vehicle body 3 can be operated to correct the position of the vehicle body 3 detected by the positioning device 40, and automatic steering can be appropriately performed, and the situation in which the operation of the driver becomes complicated can be further alleviated.

[0131] In addition, in the present embodiment, the work vehicle 1 is provided with the control device 60 that controls automatic steering, and at the start and stop of travel of the vehicle body 3 by manual steering, if the setting switch 51 is operated, the control device 60 sets a travel reference line Ll based on the position of the vehicle body 3 detected by the positioning device 40, if the steering switches 52, 54 are started to be operated, the control device 60 starts automatic steering, if the steering switches 52, 54 are stopped to be operated, the control device 60 stops automatic steering, if the correction switches 53, 63 are operated, the control device 60 corrects the position of the vehicle body 3, and if one of the switches having the same function (the steering switches 52, 54, the correction switches 53, 63) provided in the first operation section 50 to 53 and the second operation section 54, 63 is operated, the control device 60 inactivates the other switch until the end of automatic steering.

[0132] Thus, automatic steering can be appropriately performed while the vehicle body 3 is advanced or retreated. In addition, in the steering switches 52, 54, the correction switches 53, 63 having the same function, in the case where automatic steering or correction of the position of the vehicle body 3 is started by one of the switches, the other switch can be prevented from being mistakenly operated to cause the driver to accidentally stop automatic steering or correction of the position of the vehicle body 3, and safety can be ensured.

[0133] In addition, in the present embodiment, the second operation section 54 is electrically connected to the control device 60 through the electric wiring 74 arranged from the rear of the driver's seat 10 to the operation platform 9F via the side portion of the vehicle body 3. Thus, an input signal corresponding to the operation of the second operation section 54 can be transmitted from the second operation section 54 to the control device 60 through the electric wiring 74, and automatic steering can be performed in accordance with the operation of the second operation section 54.

[0134] In addition, in the present embodiment, the protection mechanism 6 that protects the driver's seat 10 is provided, and the second operation section 54, 63 is detachable with respect to the protection mechanism 6. Thus, the driver can install the second operation section 54, 63 at a preferable position of the protection mechanism 6, and the operability of the second operation section 54, 63 can be improved.

[0135] Further, in the present embodiment, the protection mechanism 6 has struts 6L, 6R each of which is erected at the rear of the vehicle body 3 on the left and right, and a beam 6b that links upper end portions of the struts 6L, 6R to each other, and the second operation portion 54, 63 includes: a housing (switch box) 19 that is detachable with respect to either of the struts 6L, 6R; and operable keys 54a, 54a, 63L, 63R provided on a surface (front surface) 19f of the housing 19 other than a mounting surface 19b that is in contact with the strut 6L.

[0136] As described above, when the automatic steering is performed while the vehicle body 3 is being backed up, even if the driver turns his head rearward A2 in order to confirm safety, the driver's field of view can be prevented from being narrowed by the protection mechanism 6 and the second operation portion 54, 63. Further, since the driver who turns his head rearward A2 can visually confirm the keys 54a, 54b, 63L, 63R of the second operation portion 54, 63 while confirming safety of the rearward A2, the operability of the keys 54a, 54b, 63L, 63R can be improved.

[0137] Further, in the present embodiment, the work vehicle 1 is provided with a detachment prevention member 57 that prevents the second operation portion 54 from detaching from the protection mechanism 6. Thereby, the second operation portion 54 can be prevented from detaching from the protection mechanism 6 due to vibration or the like transmitted from the work vehicle 1, and thus the second operation portion 54 can be prevented from being lost or damaged.

[0138] Further, the work vehicle 1 of the present embodiment is provided with: the vehicle body 3 that is capable of traveling forward and backward by either of manual steering by the steering wheel 30 and automatic steering; the power machine 4 provided to the vehicle body 3; the work device 2 supported to the vehicle body 3; the PTO shaft 16 that transmits power of the power machine 4 to the work device 2; and the control device 60 that controls the automatic steering and driving of the PTO shaft 16, the control device 60 permitting the automatic steering at the time of backing up of the vehicle body 3 when the PTO shaft 16 is stopped, and prohibiting the automatic steering at the time of backing up of the vehicle body 3 when the PTO shaft 16 is driven.

[0139] According to the above structure, in the work vehicle 1, the automatic steering at the time of backing up is performed in the stop of the PTO shaft 16, and the automatic steering at the time of backing up is not performed in the driving of the PTO shaft 16, and thus the automatic steering at the time of backing up can be stably and safely performed.

[0140] Further, in the present embodiment, the work vehicle 1 is provided with the PTO operation member 24, 23 (PTO shift lever 24, PTO switch 23) which is an operation member for operating the drive of the PTO shaft 16, is capable of being switched from the neutral position Qn, Qx to the drive position Q1, Q2, Q3, Qb, Qz, and when the PTO operation member 24, 23 is in the neutral position Qn, Qx, the PTO shaft 16 is stopped, and the control device 60 permits automatic steering when the vehicle body 3 is backing up, and when the PTO operation member 24, 23 is switched to the drive position Q1, Q2, Q3, Qb, Qz, the control device 60 prohibits automatic steering when the vehicle body 3 is backing up, and the PTO shaft 16 is capable of being driven.

[0141] According to the above structure, when the PTO operation member 24, 23 is switched to the drive position Q1, Q2, Q3, Qb, Qz and the PTO shaft 16 is driven, automatic steering when backing up cannot be performed, and when the PTO operation member 24, 23 is in the neutral position Qn, Qx and the PTO shaft 16 is stopped, automatic steering when backing up can be performed. Therefore, automatic steering when the work vehicle 1 is backing up can be performed stably and safely.

[0142] Further, in the present embodiment, the work vehicle 1 is provided with the positioning device 40 which is capable of detecting the position of the vehicle body 3, the setting switch 51 which is operated for the setting of the travel reference line L1 which is to be a reference for automatic steering, and the steering switches 52, 54 which are operated for the start and stop of automatic steering, the control device 60 sets the travel reference line L1 based on the position of the vehicle body 3 detected by the positioning device 40 at the time of travel of the vehicle body 3 performed by manual steering in accordance with the operation of the setting switch 51, in the case where automatic steering when the vehicle body 3 is backing up is permitted, the control device 60 starts automatic steering in accordance with the start operation of the steering switches 52, 54, performs automatic steering based on the travel reference line L1 and the position of the vehicle body 3 detected by the positioning device 40, and stops automatic steering in accordance with the stop operation of the steering switches 52, 54, and in the case where automatic steering when the vehicle body 3 is backing up is prohibited, the control device 60 does not perform the start and stop of automatic steering in accordance with the operation of the steering switches 52, 54.

[0143] According to the above structure, by the operation of the setting switch 51 and the steering switches 52, 54, automatic steering when the work vehicle 1 is backing up can be performed reliably and stably. Further, in the case where automatic steering when backing up is prohibited, even if the steering switches 52, 54 are started to be operated, automatic steering when backing up is not started, and therefore, safety can be ensured.

[0144] Further, in the present embodiment, the work vehicle 1 is provided with a notification device (display device) 45 that notifies of a case where automatic steering at the time of rearward travel of the vehicle body 3 is prohibited. Thus, in a case where the work vehicle 1 prohibits automatic steering at the time of rearward travel, it is possible to prevent the driver of the work vehicle 1 from misinterpreting that a failure has occurred when the automatic steering is not performed.

[0145] Further, in the present embodiment, the notification device 45 also notifies of guidance to stop the PTO shaft 16. Thus, since the PTO shaft 16 is driven, it is possible to make the driver of the work vehicle 1 aware that automatic steering at the time of rearward travel is prohibited and that automatic steering at the time of rearward travel is permitted if the PTO shaft 16 is stopped.

[0146] Further, in the present embodiment, in a case where automatic steering at the time of rearward travel of the vehicle body 3 is prohibited, the notification device 45 performs the above notification at the time of instructing the start of automatic steering. Thus, at the time when the driver wants the work vehicle 1 to start automatic steering, it is possible to recognize that automatic steering at the time of rearward travel is prohibited and that the reason for the prohibition is the driving of the PTO shaft 16 or the like. Further, it is possible to suppress the frequency of notification by the notification device 45, prevent the driver from becoming complicated due to the notification, or reduce consumed electric power.

[0147] The present application has been described above, but the embodiments disclosed this time should not be understood as being all inclusive in terms of the scope of the present application. The scope of the present application is not represented by the above description, but is represented by the claims, and is intended to include all modifications equivalent in meaning and scope to the claims.

[0148] Explanation of Reference Numerals

[0149] 1 work vehicle

[0150] 2 work device

[0151] 3 vehicle body

[0152] 4 power machine

[0153] 16 PTO shaft

[0154] 23 PTO switch (PTO operation member)

[0155] 24 PTO shift lever (PTO operation member)

[0156] 30 steering wheel

[0157] 40 positioning device

[0158] 45 display device (notification device)

[0159] 51 setting switch

[0160] 52, 54 steering switch

[0161] 60 control device

[0162] L1 travel reference line

[0163] Q1 forward first position (drive position)

[0164] Q2 forward second position (drive position)

[0165] Q3 forward third position (drive position)

[0166] Qb reverse position (drive position)

[0167] Qn, Qx neutral position

[0168] Qz on position (drive position)

Claims

1. A work vehicle comprising: The work vehicle is provided with: a vehicle body capable of traveling forward and backward; a power machine provided to the vehicle body; a work device supported to the vehicle body; a PTO shaft transmitting power of the power machine to the work device; a steering wheel for manually steering the vehicle body; an automatic steering mechanism including an actuator for automatically steering the vehicle body; a positioning device detecting a position of the vehicle body; and a control device controlling the automatic steering mechanism and detecting a state of driving and stopping of the PTO shaft, the control device enabling automatic steering of the vehicle body by operating the automatic steering mechanism based on the position of the vehicle body detected by the positioning device and a travel reference line at the time of forward travel and backward travel of the vehicle body in which a change in vehicle speed is manually performed, the control device permitting the automatic steering at the time of backward travel of the vehicle body at the time of stopping of the PTO shaft, and performing the automatic steering at the time of instructing start of the automatic steering, the control device prohibiting the automatic steering at the time of backward travel of the vehicle body at the time of driving of the PTO shaft, and not performing the automatic steering even at the time of instructing start of the automatic steering.

2. The work vehicle according to claim 1, wherein the work vehicle is provided with a PTO operation member which is an operation member for operating driving of the PTO shaft, and is capable of being switched from a neutral position to a driving position, the PTO shaft is stopped at the time of the PTO operation member being located at the neutral position, and the control device permits the automatic steering at the time of backward travel of the vehicle body, the PTO shaft is capable of being driven at the time of the PTO operation member being switched to the driving position, and the control device prohibits the automatic steering at the time of backward travel of the vehicle body.

3. The work vehicle according to claim 1 or 2, wherein the work vehicle is provided with: a setting switch operated for the purpose of setting the travel reference line which is a reference of the automatic steering; and a steering switch operated for the purpose of instructing start and stop of the automatic steering, the control device sets the travel reference line based on the position of the vehicle body detected by the positioning device at the time of travel of the vehicle body by the manual steering in accordance with operation of the setting switch, the control device starts the automatic steering in accordance with start operation of the steering switch, performs the automatic steering based on the travel reference line and the position of the vehicle body detected by the positioning device, and stops the automatic steering in accordance with stop operation of the steering switch in the case of permitting the automatic steering at the time of backward travel of the vehicle body, the control device does not perform start and stop of the automatic steering in accordance with the operation of the steering switch in the case of prohibiting the automatic steering at the time of backward travel of the vehicle body.

4. The work vehicle according to claim 1 or 2, wherein ​ The work vehicle is provided with an informing device that informs of a case where the automatic steering is prohibited when the vehicle body is backed up.

5. The work vehicle of claim 4, wherein, The informing device also informs of guidance to cause the PTO shaft to stop.

6. The work vehicle of claim 4, wherein, The informing device performs the informing when a start of the automatic steering is instructed in the case where the automatic steering is prohibited when the vehicle body is backed up.

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