JP2018102219A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work vehicle capable of instructing to an operator, a direction to which a traveling machine body is to be steered, when turning the traveling machine body on an optional route on a field end.SOLUTION: Control means provided on a work vehicle sets an implement lowering start area of a traveling machine body 2 at the turning start time on a field end, and starts lowering of the implement, when reaching the implement lowering start area in the state where turning of the traveling machine body 2 is finished, and allows display means to display a relation between the position of the implement lowering start area and the traveling machine body 2 on the present position.SELECTED DRAWING: Figure 19

Description

  The present invention relates to a work vehicle such as a tractor or a riding rice transplanter, and more particularly to automatic control of a lifting device that lifts and lowers the work machine.

  2. Description of the Related Art Conventionally, in work such as tilling and planting performed in a farm field, a work vehicle equipped with a turning work machine automatic control that operates when turning at the field end has been proposed (Patent Document 1). In this work vehicle, when the airframe reaches the end of the field and the front wheels are steered, the distance sensor starts to accumulate the travel distance of the airframe and the work device is raised so that the travel distance of the airframe reaches the set distance. Then, the working device is lowered. Conventionally, a riding seedling transplanter has been proposed in which an automatic turning mode is provided in which the working machine is lowered when the number of rotations of the rear wheels inside the turning reaches a preset number of times after starting turning at the field end. (Patent Document 2). This riding seedling transplanter is provided so as to be able to notify that it is in the automatic turning mode by operating a notification buzzer at a predetermined interval when calculation of the travel distance after the start of turning is started.

Japanese Patent No. 4605622 Japanese Patent No. 5751314

  However, in the above-described Patent Document 1 and Patent Document 2, the headland width from the heel is set to a predetermined width if the operator does not drive the work vehicle along a predetermined route when turning at the field end. It was difficult to align.

  Therefore, the present invention enables the traveling machine body to turn along an arbitrary route at the end of the field, and the work machine is lowered after the turning is completed, and the operator can be instructed in the direction to steer the traveling machine body to complete the turning. The purpose is to provide a simple working vehicle.

The present invention provides a working vehicle (1) comprising: a traveling machine body (2) supported by the traveling device (5, 6); and a lifting device (16) that lifts and lowers the working machine (3).
A work implement lowering start area is set at the start of turning, and when the traveling machine body (2) reaches the working machine lowering start area in a state where the turning is completed, the elevating device (16) lowers the working machine (3). Control means (52) capable of executing the turning control to start
Display means (51) capable of displaying a relationship between the position of the work implement lowering start area in the state where the work implement lowering start area is set and the traveling machine body (2) at the current position. ,
It is characterized by that.

  For example, referring to FIGS. 6, 7, and 18, the display means (51) indicates whether the work implement lowering start region is located in front of or behind the traveling aircraft body (2) at the current position. It has a displayable front-rear direction display part (51b).

  For example, referring to FIGS. 6, 7, and 18, the front-rear direction display unit (51 b) can display that the distance from the traveling machine body (2) to the work implement lowering start area is not more than a predetermined value. It is provided.

  For example, referring to FIGS. 6, 7, and 18, in the display unit (51), the work implement lowering start region is located on either the right side or the left side of the traveling machine body (2) at the current position. It has a left-right direction display part (51c) which can display these.

  For example, referring to FIGS. 6, 7, and 18, the left-right direction display unit (51 c) displays the traveling direction of the traveling machine body (2) at the start of the turn and the traveling machine body (2) at the current position. Different displays are provided depending on the difference in angle between the traveling direction and the traveling direction.

  For example, referring to FIGS. 6, 7, and 18, the left-right direction display unit (51 c) includes a plurality of display units (51 i) provided to be able to switch between a display state and a non-display state.

For example, referring to FIGS. 7, 8, 9, 10, 11, 12, and 13, notification means (53 for notifying by sound that the work implement lowering start area is set) )
The notification means (53) starts notification that the work implement lowering start area is set by a short sound repeated from the start of turning, and the work implement lowering start area is set. Change of the distance from the current position of the traveling machine body (2) in the state to the work machine lowering start region, the traveling direction of the traveling machine body (2) at the start of turning, and the traveling direction of the traveling machine body at the current position The change of the angle formed by and can be notified by the change of the interval of the short sound.

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, it does not limit the structure of this invention at all.

  According to the first aspect of the present invention, the work implement lowering start area is set at the start of turning, and the turning control for starting the lowering of the working machine is executed when the traveling machine body reaches the work machine lowering start area in a state where the turning has been completed. Control means, and display means capable of displaying the relationship between the position of the work implement lowering start region and the traveling machine body at the current position, so that the operator selects an arbitrary route at the field edge and selects the traveling machine body It is possible to turn and to know the direction in which the traveling machine body should be steered to go to the work machine lowering start region.

  According to the second aspect of the present invention, the display means has the front-rear direction display unit capable of displaying whether the work implement lowering start region is located in front of or behind the traveling machine body at the current position. The operator can know the front-rear direction in which the traveling machine body should be steered in order to go to the work machine lowering start region.

  According to the third aspect of the present invention, the front-rear direction display unit is provided so as to be able to display that the distance from the traveling machine body to the work machine lowering start area is equal to or less than a predetermined value. It is possible to know whether or not the aircraft descending start area is almost reached.

  According to the fourth aspect of the present invention, the display means has a left-right direction display unit capable of displaying whether the work implement lowering start region is located on the right side or the left side of the traveling machine body at the current position. Therefore, the operator can know the direction in which the traveling machine body should be steered in order to go to the work machine lowering start region.

  According to the fifth aspect of the present invention, the left-right direction display unit is provided so as to be able to display differently depending on the difference between the traveling direction of the traveling vehicle body at the start of turning and the traveling direction of the traveling aircraft body at the current position. Therefore, the operator can know the approximate angle at which the traveling direction of the traveling machine body should be changed in order to go to the work machine lowering start region.

  According to the sixth aspect of the present invention, since the left-right direction display unit has a plurality of display units that can be switched between the display state and the non-display state, the operator can change the left-right direction display unit. You can tell at a glance.

  According to the seventh aspect of the present invention, it is started to notify that the work implement lowering start area is set by a short sound repeated from the start of turning, and the work implement lowering start area is started from the current position of the traveling machine body. There is provided a notification means capable of notifying the change in the angle formed by the change in the distance to and the traveling direction of the traveling aircraft at the start of turning and the traveling direction of the traveling aircraft at the current position by a change in the interval of short sounds. Therefore, the operator does not need to continue to look at the display means when turning the traveling machine body, and the operation burden on the operator can be reduced.

The side view which shows the tractor which concerns on this Embodiment. The perspective view which shows the rear part of a driving | running part. The perspective view which shows a side panel. The top view which shows a side panel. The perspective view which shows the front part of a driving | running part. The perspective view which shows a front panel. The block diagram of a control part. The flowchart which shows the main routine of auto down control. FIG. 5 is a flowchart of control state processing. FIG. 5 is a flowchart of machine information acquisition processing. The flow diagram of airframe angle processing. Flow chart of angle calculation. The flowchart of a position calculation. The flowchart of a position flag process. The flowchart of a position determination process. The flowchart of a descent | fall start process. The flowchart of an automatic end process. 4A and 4B are diagrams illustrating contents displayed on the liquid crystal display device, where FIG. 5A is a diagram illustrating an auto-down cancel state display, FIG. 5B is a diagram illustrating a display when the auto-down execution state is performed, and FIG. The figure which shows the display when the descent of the rotary tiller by the stop is stopped, (d) is the figure which shows the display when the descent of the rotary tiller by the auto-down control is paused, (e) is the auto down The figure which shows a display when the rotary tiller is going down by control, (f) is a figure which shows an automatic down control position alerting | reporting display, (g) is a figure which shows an automatic down control position cancellation | release display, (h) is an airframe The enlarged view showing the display when the angle is within the first angle range, (i) is the enlarged view showing the display when the aircraft angle is within the second angle range, and (j) is the third angle range when the aircraft angle is Enlarged view showing the display when inside (K) is an enlarged view showing a display when the aircraft angle is within the turn completion angle range and the Y coordinate of the traveling aircraft is outside the predetermined range, and (m) is a display when the aircraft angle is within the fourth angle range. (N) is an enlarged view showing the display when the aircraft angle is within the fifth angle range, (p) is the aircraft angle within the turn completion angle range, and the Y coordinate of the traveling aircraft is within the predetermined range The enlarged view which shows a display when it is. Schematic which shows the driving | running route of a tractor.

<Overall configuration>
Hereinafter, the present embodiment will be described with reference to the drawings. As shown in FIG. 1, a tractor 1 as a working vehicle according to the present embodiment includes a traveling machine body 2 and a rotating rotary 3b, and is connected to the rear part of the traveling machine body 2 so as to be movable up and down. A rotary cultivator 3. The traveling machine body 2 includes a control unit 52 as control means shown in FIG. 7 for controlling input / output of each electric signal, and front wheels 5 and rear wheels 6 as traveling devices. A pair of front wheels 5 and rear wheels 6 are provided on the left and right, respectively, and the traveling machine body 2 is steered by steering the front wheels 5 to the left and right. The traveling machine body 2 includes a machine body frame 7 supported by the front wheels 5 and the rear wheels 6, and a driving unit 10 having a driving seat 23 on which an operator gets. In the present embodiment, unless otherwise specified, the front direction facing the operator seated on the driver's seat 23 of the tractor 1 placed on the horizontal plane is the front which is the direction of the traveling machine body 2 as the traveling direction. Define the front-rear and left-right directions based on On the output side of the control unit 52, a notification buzzer 53 is provided as a notification unit capable of notifying the operator of various types of information by sound emission, and operates according to an output signal from the control unit 52.

<Power transmission structure>
The body frame 7 includes an engine (not shown) that generates power for driving the front wheels 5 and the rear wheels 6, an engine room 9 in which the engine is housed, and a mission (not shown) arranged between the left and right rear wheels 6. And a case.

  A transmission (not shown) for shifting the power of the engine is housed inside the transmission case. The traveling transmission is shifted by a main transmission (not shown) for shifting the power of the engine in multiple stages, and the main transmission. A sub-transmission mechanism (not shown) for shifting the motive power in a multistage manner and a PTO transmission mechanism (not shown) for shifting the power to the PTO shaft are incorporated. The rotation of the PTO shaft is transmitted to the rotary cultivator 3, and the rotary 3b rotates about the rotary shaft 3a to cultivate the field.

  The inside of the transmission case is filled with lubricating oil, and this lubricating oil is supplied to a hydraulic pump (not shown) that is driven by the power of the engine. The hydraulic pressure generated by the hydraulic pump is rotated by operating the lift arm valve 20 shown in FIG. It is transmitted to a lift arm cylinder (not shown) that moves the tiller 3 up and down.

  The power passing through the main transmission mechanism and the sub-transmission mechanism is distributed to the left and right rear wheels 6 via a rear wheel differential mechanism (not shown) by a rear wheel drive shaft (not shown), and a front wheel transmission mechanism (not shown) and a front wheel drive shaft (not shown). Is distributed to the left and right front wheels 5 via a front wheel differential mechanism (not shown), and when the traveling vehicle body 2 turns left and right by turning the front wheels 5, a difference is allowed in the number of revolutions of the inner and outer wheels. It is configured so that it can travel smoothly.

  The rear wheel differential mechanism transmits power from the rear wheel drive shaft to the left and right rear wheels 6 via a pair of left and right brake mechanisms (not shown) that can brake the left and right rear wheels 6 independently. The number of revolutions per unit time of the rear wheel drive shaft and either the left or right rear wheel 6 is independently detected by the vehicle speed sensor 11 and is determined per unit time of the rear wheel drive shaft or the left or right rear wheel 6. The vehicle speed of the traveling machine body 2 is calculated on the basis of the number of rotations. Here, the vehicle speed is a movement distance per unit time of the airframe reference point 2a which is the center point of the left and right rear wheels 6 on the rotation axis of the rear wheel 6 as shown in FIG. Information on the vehicle speed at the calculated time point is transmitted to the control unit 52 by an electrical signal. Further, the control unit 52 integrates the vehicle speed with time to obtain the travel distance of the airframe reference point 2a, that is, the travel distance of the travel airframe 2.

  The front wheel speed change mechanism includes a friction multi-plate hydraulic clutch (not shown), and the hydraulic clutch is connected and disconnected, so that the traveling machine body 2 sets the average peripheral speed of the left and right front wheels 5 to the average peripheral speed of the left and right rear wheels 6. Front wheel double speed on 4WD mode in which front wheel double speed control for increasing speed drive is executed, and front wheel double speed off 4WD that drives the average peripheral speed of the left and right front wheels 5 at substantially the same speed as the average peripheral speed of the left and right rear wheels 6 A mode and a 2WD mode in which power is not transmitted to the front wheels 5 are provided to be switchable.

<Steering device>
A steering device 12 is disposed on the body frame 7. The steering device 12 includes a steering wheel 13 that an operator rotates to steer the front wheels 5, a steering column 14 shown in FIG. 6 that rotates together with the steering wheel 13, and a steering column 14 that extends to the left and right. And a tie rod (not shown) for connecting the both ends of the steering mechanism and the left and right front wheels 5 to each other. When the operator rotates the steering wheel 13, the steering column 14 rotates, and the tie rod moves to the left and right based on the rotation angle and direction of the steering column 14 to steer the left and right front wheels 5.

  The steering device 12 is provided with a stopper portion (not shown) that restricts the steering wheel 13 from rotating in one direction beyond a predetermined direction in each of the left and right rotation directions. The maximum rotation angle α1 in one direction from the neutral position of the steering wheel 13 where the traveling machine body 2 travels substantially straight is configured to be substantially the same as the maximum rotation angle in the other direction. When the steering wheel 13 is turned from the neutral position by a predetermined angle α2 slightly smaller than the maximum turning angle α1, the steering sensor 15 shown in FIG. 7 is turned on, and the steering wheel 13 is turned by α2 or more. And the rotation direction of the steering wheel 13 is detected. When the turning angle of the steering wheel 13 is less than α2 from the neutral position, the steering sensor 15 is turned off, and it is detected that the turning angle of the steering wheel 13 is less than α2. Information on the on or off state of the steering sensor 15 and the rotation direction of the steering wheel 13 is transmitted to the control unit 52 by an electrical signal.

<Elevating link mechanism>
At the rear of the traveling machine body 2, an elevator link mechanism 16 is provided as an elevator device for connecting the machine frame 7 and the rotary tiller 3 and raising and lowering the rotary tiller 3. The elevating link mechanism 16 includes a link bracket (not shown) protruding from the rear of the traveling machine body 2, a single top link 17 that is pivotally supported so as to swing up and down with respect to the link bracket, and extends rearward. A pair of left and right lower links 18 which are provided below the links and are pivotally supported so as to be swingable up and down with respect to the link bracket and extend rearward. The rear ends of the top link 17 and the left and right lower links 18 are The rotary tiller 3 is pivotally supported so as to swing up and down to form a three-point link mechanism. The left and right lower links 18 are suspended by lift arms (not shown) via lift rods (not shown) provided on the left and right, respectively. The lift arm is pivotally supported by the link bracket so that the front end of the lift arm can swing up and down, and the lower link 18 swings up and down as the lift arm moves up and down as the lift arm cylinder expands and contracts. 3 goes up and down. The swing angle of the lift arm is detected by a lift arm sensor 21 shown in FIG. 7 provided on the lift arm, and is transmitted to the control unit 52 by an electric signal.

<Operation part>
Next, the operation unit 10 will be described with reference to FIG. On the left side of the driver's seat 23, an auxiliary transmission lever 27 that is swingably supported and shifts the auxiliary transmission mechanism is supported. Below the driver's seat 23 is rotatably supported and the rotary tiller 3 is lowered. A work machine lowering speed adjusting knob 29 capable of operating a lowering speed adjusting valve (not shown) for adjusting the speed is provided. The sub-shift lever 27 is provided so that it can be operated at three shift positions of high speed, medium speed, and low speed. When the shift position of the sub-shift lever 27 is at the high speed, the engine speed is reduced. The reduction ratio divided by the rotational speed of the wheel drive shaft is the smallest of the three stages, the low speed stage is the largest, and the medium speed stage is configured so that the reduction ratio is between the high speed stage and the low speed stage. ing. Further, when the work implement lowering speed adjusting knob 29 is rotated clockwise by the operator, the lowering speed adjusting valve is operated, so that the lowering speed of the rotary cultivator 3 is lowered and rotated counterclockwise. And the descending speed increases. Information on the shift position of the sub-shift lever 27 and information on the rotation position of the work implement lowering speed adjustment knob 29 are transmitted to the control unit 52 by an electrical signal.

<Side panel>
As shown in FIGS. 2, 3, and 4, a side panel 26 on which various operation tools and lamps are arranged is provided on the right side of the driver seat 23. On the side panel 26, a main transmission lever 30 that is supported in a swingable manner to shift the main transmission mechanism, a position lever 31 that moves the rotary tiller 3 up and down, and a lift that sets the maximum raising height of the rotary tiller 3 is set. A height volume 32 and an auto down timing volume 33 are arranged.

  The speed change operation of the main speed change mechanism by the main speed change lever 30 can be performed independently of the speed change operation of the sub speed change mechanism by the sub speed change lever 27. A neutral position that does not transmit to the front wheels 5 and the rear wheels 6 and an accelerator shift position that automatically shifts gears from the 8th to the 4th by operating an accelerator pedal (not shown) are provided. The eighth gear is configured such that the speed reduction ratio by the main transmission mechanism is the smallest, and the speed reduction ratio increases as the number of gears decreases. Information on the shift position of the main shift lever 30 is transmitted to the control unit 52 by an electrical signal.

  The position lever 31 is supported so as to be able to swing back and forth, and is configured to hold the swinging position when the operator releases the operating hand. When the position lever 31 is swung back and forth, the rotary tiller 3 moves up and down to a height corresponding to the position where the position lever 31 is held. Information on the position where the position lever 31 is held is transmitted to the control unit 52 by an electrical signal.

  The raising height volume 32 is rotatably supported, and is provided so that a raising height adjusting position provided in a predetermined turning range and a hydraulic pressure taking-out position can be selected depending on the turning position. . When the turning position of the raising height volume 32 is located at the raising height adjustment position, the upper limit height when the rotary tiller 3 moves up and down when the operator turns the raising height volume 32 clockwise. The upper limit height is reduced when it is enlarged and rotated counterclockwise. When the turning position of the raised height volume 32 is located at the hydraulic pressure take-out position, the traveling machine body 2 is in a state where the hydraulic pressure is transmitted from a hydraulic take-out port (not shown) so that, for example, a front loader can be operated. At the same time, the hydraulic pressure to the lift cylinder is cut off, and the rotary tiller 3 does not move up and down. Information on the rotational position of the raised height volume 32 is transmitted to the control unit 52 by an electrical signal.

  The auto-down timing volume 33 is supported so as to be rotatable, and is provided so as to be changeable between an on position and an off position provided in a predetermined rotation range. When the rotation position of the auto down timing volume 33 is in the on position, the descent start timing of the rotary tiller 3 can be adjusted in accordance with the rotation position in auto down control described later. Information on the rotation position of the auto-down timing volume 33 is transmitted to the control unit 52 by an electrical signal. Further, the side panel 26 is provided with an automatic on lamp 48. The automatic on lamp 48 is turned off when the auto down timing volume 33 is located at the off position, and is located at the on position. Lights or blinks when an automatic down permission condition described later is satisfied or not satisfied.

<Steering wheel around>
As shown in FIG. 5, a steering wheel 13 is disposed in front of the driver seat 23, and a brake pedal 25 and an accelerator pedal for operating the left and right brake mechanisms are disposed below the steering wheel 13. Around the wheel 13, there are a starter switch 34 that is a main switch of the traveling machine body 2, a shuttle lever 35 that is operated by the operator to switch between forward and backward movement of the traveling machine body 2, and a preset upper limit height and lower limit height. A quick up lever 36 for moving the rotary tiller 3 up and down is arranged.

  The shuttle lever 35 is provided so that it can be operated at a forward position, a neutral position, and a reverse position. When the shuttle lever 35 is located at the forward position, the traveling machine body 2 moves forward, and when the shuttle lever 35 is located at the neutral position, the traveling machine body 2 is moved. The traveling stops and the traveling machine body 2 moves backward when it is in the reverse position. Information on the operation position of the shuttle lever 35 is transmitted to the control unit 52 by an electrical signal.

  The quick up lever 36 is supported so as to be swingable between the raised position, the center position, and the lowered position, and is operated by the operator after the operator raises or lowers the quick up lever 36 to the raised position. An urging member (not shown) is provided so as to return to the central position when released. In the state where the raising / lowering of the rotary tiller 3 is stopped, the rotary tiller 3 is raised to the upper limit height when the quick up lever 36 is shortened, and the rotary tiller 3 is the lower limit height when the shortening operation is performed. The position lever 31 is lowered to a height corresponding to the swing position. The operation direction and operation time of the quick up lever 36 are transmitted to the control unit 52 by an electrical signal.

<Front panel>
As shown in FIG. 6, a front panel 24 including various operation tools, a display device, and a lamp is disposed in front of the steering wheel 13. The front panel 24 includes a backup changeover switch 37 that switches between ON and OFF states of the backup mode of the traveling machine body 2 and a turn-up changeover switch 39 that switches between ON and OFF states of the turnup mode. When the traveling machine body 2 is in the backup mode on state, the backup lamp 40 is turned on, and the reverse operation in which the shuttle lever 35 is switched from the neutral position to the reverse position while the rotary tiller 3 is not positioned at the upper limit height is performed. When done, the rotary tiller 3 rises to the upper limit height. When the turning up mode 41 is in the on state, the turning up lamp 41 is lit, and when the steering sensor 15 is switched from the off state to the on state when the rotary tiller 3 is not positioned at the upper limit height, the rotary tiller 3 is turned on. It rises to the upper limit height. The switching information of the backup changeover switch 37 and the turning up changeover switch 39 is transmitted to the control unit 52 by an electrical signal.

  Further, the front panel 24 includes a four-wheel drive changeover switch 42 for connecting / disconnecting a hydraulic clutch, and a turning double speed changeover switch 43 for connecting / disconnecting the hydraulic clutch and a braking operation by a brake mechanism. Each time the operator operates the 4WD selector switch 42, the traveling machine body 2 switches between each mode in which power is transmitted to the front wheels 5 and a 2WD mode in which power is not transmitted to the front wheels 5, and each of which transmits power to the front wheels 5. In the mode, the 4WD switching lamp 45 is lit. Information on the switching operation by the 4-wheel drive switch 42 and the turning double speed switch 43 is transmitted to the control unit 52 by an electric signal.

  Each time the turning double speed changeover switch 43 is operated in a state in which the 4WD switching lamp 45 is lit, the traveling machine body 2 switches between the front wheel double speed OFF 4WD mode, the front wheel double speed ON 4WD mode, and the autobrake mode. In the front wheel double speed on 4WD mode, the turning double speed lamp 46 is lit, and in the auto brake mode, the front wheel double speed control is executed and the control unit 52 automatically brakes the rear wheel 6 on the inside of the turn. Is executed and the autobrake turning lamp 47 is lit.

  The front panel 24 includes an automatic selector switch 49 capable of switching between a working mode for the traveling machine body 2 to perform a plowing operation on a farm field and a traveling mode for traveling on a road or the like outside the farm field, and the traveling machine body 2 has a working mode. There is an automatic switching lamp 50 that displays which one of the driving modes is selected. Each time the operator operates the automatic selector switch 49, the work mode and the travel mode of the traveling machine body 2 are alternately switched. When the traveling body 2 is switched from the work mode to the traveling mode, both the backup mode and the turning up mode are turned off, and when the front wheel double speed on 4WD mode or the auto brake mode is set, the front wheel double speed off 4WD mode is set. In the case of the driving mode, the two-wheel driving mode is maintained, and the raising and lowering of the rotary tiller 3 by the quick up lever 36 is restricted, and when the main transmission lever 30 is at the accelerator shifting position, the operation of the accelerator pedal is performed. Thus, the shift operation of the main transmission mechanism is enabled. When the traveling machine body 2 is switched from the traveling mode to the working mode, the state is any of the backup mode, the turning-up mode, the front wheel double speed on 4WD mode, the auto brake mode, and the 2WD mode before switching from the working mode to the traveling mode. Thus, the rotary tiller 3 can be moved up and down by the quick up lever 36, and the speed change operation of the main speed change mechanism by the operation of the accelerator pedal is restricted. Switching information between the work mode and the travel mode by the automatic selector switch 49 is transmitted to the control unit 52 by an electrical signal.

<Liquid crystal display device>
Further, the front panel 24 includes a liquid crystal display device 51 as display means for displaying various information related to the state of the traveling machine body 2 and tilling work, and the liquid crystal display device 51 includes an auto-down state display unit as shown in FIG. 51a and a notification display part 51e. The auto-down state display unit 51a displays engine temperature display and temperature / fuel display including fuel remaining amount display or information related to auto-down control to be described later. The notification display unit 51e displays engine speed display. In addition, an engine speed / usage time display composed of a total use time display or a notice regarding auto-down control is displayed.

<Block diagram>
FIG. 7 shows a control block diagram according to the present embodiment. A control unit 52 capable of executing auto-down control described later includes a microcomputer 52a having a CPU 52b, a ROM 52c, a RAM 52d, an interface 52e, and the like. The control unit 52 includes a steering sensor 15, a lift arm sensor 21, a vehicle speed sensor 11, a quick up lever 36, a main transmission lever 30, a sub transmission lever 27, a position lever 31, an automatic selector switch 49, an auto down timing volume 33, a raising height. Micro based on signals input from the volume 32, shuttle lever 35, turning double speed changeover switch 43, 4WD changeover switch 42, backup changeover switch 37, turnup changeover switch 39, work implement lowering speed adjustment knob 29 and starter switch 34. A signal is output by the calculation of the computer 52a, and the lift arm valve 20 and the notification buzzer 53 are operated, and the lift up lamp 22, the automatic switching lamp 50, the turning double speed lamp 46, the 4WD switching lamp 45, the turning up run 41, the backup lamp 40, and controls the turning on and off of the auto brake swivel lamp 47 and automatic entrance ramp 48, and displays various information on a liquid crystal display device 51.

<Auto-down control>
Next, the auto-down control as the turning control executed by the control unit 52 is an example of the flowcharts of FIGS. 8 to 17, the notification contents by the liquid crystal display device 51 of FIG. This will be described with reference to a schematic diagram of FIG. In the automatic down control, the tractor 1 that has reached the field end J raises the rotary cultivator 3 in the tilling work of the field H performed while the traveling machine body 2 repeats straight traveling and reciprocating while turning at the field end J. After turning, the rotary tiller 3 is automatically started to descend when reaching a descending start line as a boundary of the work implement descending start area.

<Main routine>
FIG. 8 is a flowchart showing a main routine of auto-down control. When the starter switch 34 is turned on by the operator, the main routine is started. As shown in FIG. 18A, the temperature / fuel display of the auto-down state display unit 51a and the notification display unit 51e are displayed on the liquid crystal display device 51. An auto-down cancel status display consisting of an engine speed and usage time display is displayed. During execution of the main routine, the data acquisition process (step S1) to the automatic end process (step S9) are sequentially repeated until the starter switch 34 is turned off. First, the operator measures an appropriate headland width M when performing a tilling operation while reciprocating the field H in the directions of the paths L1 and L2 shown in FIG. Specifically, for example, the right end or the left end of the rotary cultivator 3 is brought close to the ridge E and travels along the ridge E to mark the width of the cultivated by the rotary cultivator 3. .

  Next, the operator performs various settings as preparations for performing tilling work. First, the traveling machine body 2 is set to the operation mode by operating the automatic selector switch 49, and after the rotational position of the raised height volume 32 is set to the raised height adjusting position, the rotational position of the auto down timing volume 33 is set. By changing from the off position to the on position, the control unit 52 changes from the auto down off state to the auto down on state, and the automatic on lamp 48 starts blinking. Further, the operator operates the turning double speed changeover switch 43 and the 4WD changeover switch 42 to set the traveling machine body 2 to the front wheel double speed ON 4WD mode or the autobrake mode, and shifts the main transmission lever 30 and the auxiliary transmission lever 27. By operating and setting the total reduction gear ratio determined by the combination of the gear stage by the main transmission mechanism and the gear stage by the sub-transmission mechanism to be larger than the predetermined auto-down reduction ratio, the auto-down permission condition is satisfied and the automatic The on lamp 48 lights up. In addition, the operator puts the traveling machine body 2 in the turn-up mode or the backup mode on by operating the turn-up changeover switch 39 and the backup changeover switch 37 as necessary.

  When the main routine is started, the control unit 52 performs a data acquisition process for detecting the presence or absence of a predetermined turning start operation (step S1). Here, the turning start operation refers to switching from the neutral position to the reverse position of the shuttle lever 35 in the backup mode on state and the rotary tiller 3 not positioned at the upper limit height, and the turning up mode on state. In addition, when the rotary tiller 3 is not positioned at the upper limit height, the steering sensor 15 is switched from the off state to the on state, and the quick up lever 36 is stopped for a predetermined time t1 or longer when the rotary tiller 3 is stopped. This is a lifting operation.

  The operator aligns the direction of the traveling machine body 2 with the path L1 shown in FIG. 19, and performs the tilling work while moving the traveling machine body 2 straight toward the field end J along the path L1. When the traveling machine body 2 approaches the field end J, the operator continues the tilling work while visually checking the position of the rotary shaft 3a, and when the rotary shaft 3a reaches the work boundary C marked with the headland width M. When any one of the turning start operations is performed, an auto-down start flag is set.

  In the present embodiment, the description will be made with reference to the routes L1, T, and L2 shown in FIG. 19, but the traveling route at the time of turning at the field end J is not limited to this, for example, the traveling machine body 2 reaches the shore E. Then, the operator may turn the steering wheel 13 clockwise by α2 or more, and turn the traveling machine body 2 while moving it backward in the backup mode on state so that the direction of the traveling machine body 2 matches the path L2. Further, when the rotary shaft 3a reaches the work boundary C at the field end J, the operator turns the steering wheel 13 counterclockwise by α2 or more and turns the traveling machine body 2 forward by turning approximately 90 ° to the left. Then, with the turning angle of the steering wheel 13 returned to the neutral position, the traveling machine body 2 is moved straight back and forward to an appropriate position, and then the steering wheel 13 is advanced counterclockwise and rotated forward by α2 or more to the left. You may turn 90 degrees and you may match | combine the direction of the traveling body 2 with the path | route L2.

<Control status processing>
Next, the control unit 52 performs control state processing (step S2) for determining whether or not to permit execution of processing for calculating the current position of the traveling machine body 2 and the descending start line. FIG. 9 shows a subroutine of control state processing (step S2). When the control state process (step S2) is started, the control unit 52 first determines whether or not the control unit 52 is in the auto down on state (step S201).

  When the control unit 52 is in the auto-down on state (YES in step S201), the control unit 52 determines whether or not an auto-down execution flag is set (step S202). Here, the auto-down execution flag is a flag that stands when the control unit 52 is in the auto-down execution state in which the position of the traveling vehicle body 2 that is turning, the calculation of the descent start line, and the like are standing. For convenience, the state in which the auto-down execution flag is off will be referred to as an auto-down cancel state. When the auto-down execution flag is off (NO in step S202), the control unit 52 determines whether or not the auto-down start flag is set (step S203).

  In step S203, when the auto-down start flag is cleared (NO in step S203), the control unit 52 returns the processing to the main routine, and when the auto-down start flag is set (YES in step S203), the control is performed. The unit 52 drops the auto-down start flag (step S204), and determines whether or not the auto-down permission condition is satisfied (step S205).

  When the automatic down permission condition is not satisfied (NO in step S205), the control unit 52 returns the process to the main routine, and when the automatic down permission condition is satisfied (YES in step S205), the control unit 52 The auto-down execution flag is set to enter the auto-down execution state, and the auto-down state display unit 51a is formed with the front-rear direction display unit 51b, the left-right direction display unit 51c, and the warning display unit 51d. 18 (b), the symbols shown in FIG. 18 (h) are displayed on the front-rear direction display unit 51b and the left-right direction display unit 51c, and the notification buzzer 53 is notified by a short sound repeated at a predetermined time t5. Is started (step S206), and the process returns to the main routine. Here, the time when the auto-down execution flag is changed to the state where the auto-down execution flag is set is referred to as a turn start time. Further, in the front-rear direction display unit 51b and the left-right direction display unit 51c, based on the results from the airframe information acquisition process (step S3) to the position flag process (step S10) described later, FIG. One of the symbols shown in the above is displayed.

  When the auto-down execution flag is set in step S202 (YES in step S202), the control unit 52 determines whether or not the auto-down permission condition is satisfied (step S207). When not established (NO in step S207), that is, the traveling machine body 2 has once performed turning or tilling work in the auto-down execution state, but for some reason, an operation that does not satisfy the auto-down permission condition is performed. When this happens, the control unit 52 blinks the automatic on lamp 48 to notify the operator that the automatic down permission condition is not satisfied (step S208), and performs an automatic down execution flag and an automatic down start flag as the automatic down reset processing. Are dropped (step S210), and the automatic down cancel state is entered. This may be the case, for example, when the plowing work is completed and the operator operates the automatic selector switch 49 to switch the traveling machine body 2 from the working mode to the traveling mode.

  When the automatic down permission condition is satisfied in step S207 (YES in step S207), the control unit 52 determines whether or not an automatic down release flag is set (step S209). The auto-down cancel flag is a flag that is set when an auto-down cancel condition (to be described later) is satisfied in the automatic end process (step S9) or the like in the auto-down execution state. When the auto-down cancel flag is off (NO in step S209), the control unit 52 returns the process to the main routine. When the auto-down-off state is set in step S201 (NO in step S201) or the auto-down cancel flag is set in step S209 (YES in step S209), the control unit 52 performs auto-down. Both the execution flag and the auto-down start flag are dropped, the auto-down execution state is canceled as an auto-down reset process to enter the auto-down release state (step S210), and the process returns to the main routine.

<Aircraft information acquisition processing>
FIG. 10 is a machine information acquisition process for reading information such as the type and setting of the tractor and calculating a descent reference line F as a reference for determining a descent start line based on the position of the traveling machine 2 at the start of turning (step S3). ) Subroutine. When the body information acquisition process is started, the control unit 52 reads the maximum output of the engine stored in advance in the control unit 52 as acquisition of horsepower settings (step S301) and acquires the front wheels 5 and rear wheels as acquisition of tire settings. The type and dimensions of the travel device composed of 6 etc. are read (step S302). The types of traveling devices include only a pair of front wheels 5 and a pair of rear wheels 6, a pair of front wheels 5, a pair of crawlers and a pair of crawlers, etc. The dimensions of the traveling device include the length of the crawler or the front wheels 5 and the like. There are an inter-axis distance with the rear wheel 6, a distance between the left and right traveling devices, and the like. For this reason, the traveling device is not limited to the present embodiment, and may be a combination of the front wheel 5 and the crawler or only the crawler. Next, the control unit 52 reads whether the traveling machine body 2 is in the front wheel double speed off 4WD mode, the front wheel double speed on 4WD mode, or the autobrake mode (step S303).

  The control unit 52 stores in advance a turning inner periphery and a turning outer periphery corresponding to various combinations of the results of Step S301, Step S302, and Step S303. The circumference and the turning circumference are read (step S304). Here, the turning inner periphery and the turning outer periphery refer to the rear wheels 6 inside and outside the turning when the traveling machine body 2 turns 360 ° with the steering wheel 13 turned to either the left or right maximum turning angle. It is the movement distance.

  Next, the control unit 52 calculates a turning circumference that is an average value of the turning inner periphery and the turning outer periphery based on the turning inner periphery and the turning outer periphery read in step S304 (step S305), and based on the turning circumference. The turning radius r is calculated (step S306). The turning radius r is a radius of an arc trajectory drawn by the body reference point 2a when the traveling body 2 turns in a state where the steering wheel 13 is turned to either the left or right maximum turning angle. Calculated by dividing by 2 times the circumference.

  Next, the control unit 52 reads the hitch length A, which is stored in the control unit 52 in advance, which is the distance in plan view between the rotary shaft of the rear wheel 6 and the rotary shaft 3a when the rotary 3b is landed (step S307). ), The vehicle speed measured by the vehicle speed sensor 11 is read (step S308), and the rotational position of the dashing height and the raised height volume 32 and the rotational position of the work implement lowering speed adjustment knob 29 are read and based on the vehicle speed. A descending travel distance D in which the machine body reference point 2a moves from when the rotary tiller 3 starts descending to when it lands is calculated (step S309). Here, the dashing height refers to the descending speed after the rotary tiller 3 is lowered to a predetermined height so that the traveling machine body 2 does not suddenly accelerate by the rotational force of the rotary 3b when the rotary 3b is grounded. This is the height that becomes the changing point of the descent speed that is set in advance when it is decreased and grounded slowly.

  As shown in FIG. 19, the control unit 52 uses the position of the airframe reference point 2a at the start of turning, that is, the turning start position as the origin O in a plan view, and the horizontal axis X that is the rotation axis of the rear wheel 6 at this time. And a two-dimensional orthogonal coordinate system with a vertical axis Y that passes through the origin O and passes through the origin O and has a rearward direction of the traveling machine body 2 at the start of turning as a plus direction, and obtains machine information (step S3). ) Is set on the coordinate system based on the results of steps S307 to S309 performed as a reference for calculating the descent start line defined by only the Y coordinate (step S310). The position of the traveling machine body 2 on the coordinate system is specified by the X coordinate in the horizontal axis X direction and the Y coordinate in the vertical axis Y direction of the machine body reference point 2a.

  The position of the rotary shaft 3a of the rotary tiller 3 that has landed after turning coincides with the work boundary C that is the position of the rotary shaft 3a of the rotary tiller 3 in the landing state at the start of turning, that is, travel at the start of turning. The rotary cultivator 3 lands at the work resuming position G where the Y coordinate of the machine reference point 2a is equal to twice the hitch length A in the state where the direction of the machine body 2 and the direction of the traveling machine body 2 after turning are opposite. Then, when the tilling work is resumed, the tilling work can be performed by aligning the headland width M from the shoreline E. When the traveling machine body 2 is traveling along the route L2, if the traveling machine body 2 turns at the field end J before the descent traveling distance D before the work resuming position G starts, the traveling machine body 2 travels. The tilling work can be resumed from the work resuming position G without stopping. In this case, the Y coordinate obtained by subtracting the descent travel distance D from the Y coordinate of the work resuming position G becomes the Y coordinate of the descent reference line F. When calculating the descending reference line F, the control unit 52 returns the processing to the main routine. In addition, the operator operates the auto down timing volume 33 to set the Y coordinate of the position where the rotary tiller 3 starts to descend with respect to the descending reference line F from the minimum −S using S having a predetermined length. It is possible to set a descent set line adjusted within a range of maximum + S.

<Airframe angle processing>
FIG. 11 shows a subroutine of the aircraft angle process (step S4) for calculating the change in the direction of the traveling vehicle 2 in the auto-down execution state and determining the completion of the turn based on the calculation result. The control unit 52 determines whether or not the auto-down execution flag is set, the vehicle speed of the traveling machine body 2 is other than 0, and the steering sensor 15 is on (step S401). When (YES in step S401), based on the vehicle speed and the turning radius r, a change in the direction of the traveling vehicle body 2 in a minute time dt, that is, an angle change amount is calculated (step S403), and the angle change amount is accumulated to start turning. An aircraft angle that is an angle formed by the direction of the traveling aircraft 2 at the time and the orientation of the traveling aircraft 2 at the time of calculation is calculated (step S404). If any of the above conditions is not satisfied in step S401 (NO in step S401), the angle change amount is set to 0 (step S402), and the aircraft angle is calculated (step S404).

  When any of the turning start operations is performed by the operator, the power transmission from the PTO shaft to the rotary tiller 3 is cut off, and the rotary tiller 3 rises to the upper limit height, is in the auto down on state and the auto down start condition And when all the automatic down permission conditions are satisfied, it will be in an automatic down execution state, and the calculation of the position and direction of the traveling machine body 2 in the field H will be started. At this time, the notification buzzer 53 starts notification by a short sound repeated at an interval of a predetermined time t5, and the warning display section 51d displays an auto-down caution display “AUTODOWN / Descent caution” shown in FIG. The symbols in FIG. 18H are displayed on the front-rear direction display unit 51b and the left-right direction display unit 51c. The operator rotates the steering wheel 13 clockwise to the maximum rotation angle, and causes the traveling machine body 2 to travel along an arcuate path T whose radius is the turning radius r.

  Next, the control unit 52 determines whether or not the aircraft angle is 90 ° or more (step S405), and when the aircraft angle is less than 90 ° (NO in step S405), the control unit 52 does not reach the turn. If the aircraft angle is less than 20 °, the design shown in FIG. 18 (h) is displayed on the front / rear direction display unit 51b and the left / right direction display unit 51c. The symbols shown in FIG. 18 (i) are displayed on 51b and the horizontal display 51c (step S406), and the process returns to the main routine. The left-right direction display unit 51c is a rectangular display unit 51i capable of switching between a non-display state in which only the outline is displayed and a display state in which the inside of the outline is displayed in the same color as the outline. When the three display units 51i are arranged on the left and right sides of the part 51b and the display state display part 51i is displayed only on the right side, the traveling body with the operator turning the steering wheel 13 clockwise. It means that it can approach the descent start line when driving 2. Further, when the symbols displayed on the front-rear direction display unit 51b are oriented as shown in FIG. 18 (h), it means that there is a descending start line behind the traveling machine body 2, and the front-rear direction display unit When the symbol displayed in 51b is in the direction shown in FIG. 18 (j), it means that there is a descending start line in front of the traveling machine body 2. The operator continues to turn the traveling machine body 2 along the route T while maintaining the state in which the steering wheel 13 is rotated clockwise to the maximum rotation angle while looking at the front-rear direction display unit 51b and the left-right direction display unit 51c. To do.

  In step S405, when the aircraft angle is 90 ° or more (YES in step S405), the control unit 52 determines that the vehicle has been turned (step S407), and determines whether the turning angle condition has been achieved. (Step S408). The achievement of the turning angle condition means that the airframe angle is within a predetermined turning completion angle range in which it is determined that the turning has been completed. The turn complete angle range is α3 <α4, using predetermined angles α3 and α4, and after the aircraft angle changes from outside the range of 180 ° ± α3 to within the range of 180 ° ± α3, the turn complete angle range is 180. After the vehicle body angle changes from within the range of 180 ° ± α4 to outside the range of 180 ° ± α4, the turn completion angle range becomes 180 ° ± α3. In this way, by changing the turn completion angle range depending on whether or not the airframe angle is within the turn completion angle range, the process is frequently switched when the airframe angle is near the upper limit or lower limit of the turn completion angle range. Is preventing.

  When the turning angle condition is not achieved in step S408 (NO in step S408), the control unit 52 displays the front-rear direction display unit 51b and the left-right direction display unit 51c when the turning angle is smaller than the turning completion angle range. When the symbol shown in FIG. 18 (j) is displayed and the turning angle is larger than the turning completion angle range and not more than 270 °, the symbol shown in FIG. 18 (m) is displayed on the front-rear direction display unit 51b and the left-right direction display unit 51c. When the turning angle is over 270 ° and less than 300 °, the symbols shown in FIG. 18 (n) are displayed on the front / rear direction display unit 51b and the left / right direction display unit 51c, and the turning angle condition flag is cleared ( Step S409), the process is returned to the main routine.

  When the turning angle condition is achieved in step S408 (YES in step S408), the control unit 52 determines that the coordinates of the airframe reference point 2a at the time of calculation on the coordinate system, that is, the Y coordinate of the current position is a descending start line. When the distance is within a predetermined distance in the minus direction, the front and rear direction display part 51b and the display part 51i adjacent to the left and right of the front and rear direction display part 51b both display the design shown in FIG. 18 (p) and The notice buzzer 53 changes the short sound interval to a predetermined time t6 shorter than t5 to notify the operator that the arrival at the descending start line is near, and in other cases, the front / rear direction display unit 51b and the left / right direction display 18c is displayed on the part 51c, a turning angle condition flag is set (step S410), and the process returns to the main routine.

  The operator confirms that the symbol shown in FIG. 18 (k) is displayed on the left / right direction display portion 51c, returns the steering wheel 13 to the neutral position, and the symbol shown in FIG. 18 (p) appears on the left / right direction display portion 51c. Until it is displayed, the traveling machine body 2 is caused to travel straight along the route L2 in parallel with the route L1.

<Angle calculation>
FIG. 12 shows a subroutine of angle calculation (step S5) for calculating the current position based on the aircraft angle. First, the control unit 52 reads the angle change amount, the airframe angle, and the vehicle speed (step S501), and based on the angle change amount, the airframe angle, and the vehicle speed, the change in the position of the traveling airframe 2 on the coordinate system in the minute time dt, A coordinate change amount is calculated (step S502). Next, the control unit 52 determines whether or not the vehicle speed of the traveling machine body 2 is other than 0 (step S503). When the vehicle speed is 0 (YES in step S503), the current position is maintained (step S503). S504) The process is returned to the main routine. When the vehicle speed is other than 0 (NO in step S503), a new current position is calculated by accumulating the coordinate change amount at the current position (step S505), and the process is performed in the main routine. Return to.

<Position calculation>
FIG. 13 shows a subroutine for position calculation (step S6) for calculating a descent start line based on the descent reference line F, the current position, and the descent setting line. First, the control unit 52 determines whether or not it is in an auto-down execution state (step S601), and when not in an auto-down execution state (NO in step S601), adopts a lowering setting line as a lowering start line (step S602). ) Return the processing to the main routine. Here, the descent start line is a variable defined only by the Y coordinate. The descent reference line F, the descent setting line, the current descent line are calculated by the position calculation (step S6) and the position determination process (step S7) described later in detail. It is a straight line that changes depending on the result of the calculation based on the position, the machine body angle, and the path of the traveling machine body 2 and starts the descent of the rotary tiller 3 when the current position is reached. In the automatic down execution state (YES in step S601), the control unit 52 determines that the Y coordinate of the lowering setting line is greater than or equal to the Y coordinate of the lowering reference line F (YES in step S603) and the lowering setting line. When the Y coordinate is equal to or greater than the Y coordinate of the current position and less than the Y coordinate of the descent reference line F (YES in step S605), the Y coordinate of the descent setting line is adopted as the Y coordinate of the descent start line (step S606). Return to the main routine.

  In the automatic down execution state, the control unit 52 starts the descent when the Y coordinate of the descent reference line F exceeds the Y coordinate of the descent setting line and is equal to or less than the Y coordinate of the current position (YES in step S607). The Y coordinate of the descending reference line F is adopted as the Y coordinate of the line (step S608), and the process returns to the main routine. In the auto-down execution state, when the Y coordinate of the current position exceeds the Y coordinate of the descent setting line and is less than the Y coordinate of the descent reference line F (NO in step S607), the control unit 52 It is determined whether 15 is on or the shuttle lever 35 is in the reverse position (step S609). When the steering sensor 15 is in the on state or the shuttle lever 35 is positioned at the reverse position (YES in step S609), the control unit 52 sets a predetermined hysteresis value as the Y coordinate of the descent start line to the Y coordinate of the current position. A value obtained by adding γ is adopted (step S610), and the process returns to the main routine. In step S609, when the steering sensor 15 is neither in the on state nor in the state in which the shuttle lever 35 is in the reverse position (NO in step S609), the process returns to the main routine. Thus, in the auto-down execution state, the state where the descent start line is set while the Y coordinate of the descent start line changes with the change of the Y coordinate of the current position and the descent setting line is maintained.

  The operator causes the traveling machine body 2 to travel forward while traveling straight along the route L2, and the Y coordinate of the current position reaches within a predetermined distance β from the descending start line, and the front-rear direction display unit 51b and the left-right direction display unit 51c are shown in FIG. The symbol shown in (p) is displayed, and it is confirmed that the interval of the short sound of the notification buzzer 53 is reduced, and it is known that the start of the descent of the rotary tiller 3 is near.

<Position flag processing>
Even when the current position reaches the descending start line, when the aircraft angle is greatly deviated from the route L2, when the steering sensor 15 is on and when the traveling aircraft 2 is moving backward, the traveling aircraft 2 is It is not determined that the descent start line has been properly reached, and descent of the rotary tiller 3 is not started. FIG. 14 shows a subroutine of a position flag process (step S10) for determining whether or not a position condition for determining that the traveling machine body 2 has properly reached the descending start line is satisfied. When the Y coordinate of the current position exceeds the value obtained by adding the hysteresis value γ to the Y coordinate of the descending start line (YES in step S11), the control unit 52 clears the position condition flag and sets the position pass condition flag ( Step S14), the process is returned to the main routine. Here, the position condition flag is one of the conditions for the control unit 52 to set a lowering flag for starting the lowering of the rotary tiller 3 in the position determination process described in detail later, and the current position is set to the lowering start line. It is a flag indicating that it has been reached. The position passing condition flag is a flag indicating that the current position has reached the descent start line, but has passed the descent start line because the conditions for lowering the rotary tiller 3 are not satisfied.

  In step S11, when the Y coordinate of the current position is equal to or less than the value obtained by adding the hysteresis value γ to the Y coordinate of the descent start line (NO in step S11), the control unit 52 determines that the Y coordinate of the current position is the descent start line. It is determined whether or not the value is less than the value obtained by subtracting the hysteresis value γ from the Y coordinate (step S12). In step S12, when the Y coordinate of the current position is less than the value obtained by subtracting the hysteresis value γ from the Y coordinate of the descending start line (YES in step S12), the control unit 52 sets the position condition flag and the position pass condition flag. Both are dropped (step S13), and the process returns to the main routine. In step S12, when the Y coordinate of the current position is equal to or greater than the value obtained by subtracting the hysteresis value γ from the Y coordinate of the descent start line (NO in step S12), the control unit 52 determines whether or not the position passing condition flag is set. Is determined (step S15).

  In step S15, when the position passing condition flag is set (YES in step S15) and the Y coordinate of the current position is less than the Y coordinate of the descending start line (YES in step S16), the position passing condition flag is lowered. When the Y coordinate of the current position exceeds the Y coordinate of the descending start line (YES in step S17), the control unit 52 sets a position condition flag (step S18). When the Y coordinate of the current position is greater than or equal to the Y coordinate of the descent start line at step S16 (NO at step S16) and when the Y coordinate of the current position is less than or equal to the Y coordinate of the descent start line (step S16) In step S17 NO), the controller 52 returns the process to the main routine.

<Position determination process>
FIG. 15 shows a subroutine of position determination processing (step S7) that issues a lowering request for the rotary tiller 3 based on the result of the position flag processing (step S10). First, the control unit 52 determines whether or not the vehicle speed is other than 0 (step S701). When the vehicle speed is 0 (NO in step S701), the process returns to the main routine, and when the vehicle speed is not 0 (step S701). Is YES), it is determined whether or not the steering sensor 15 is in an off state and the shuttle lever 35 is located at the forward position (step S702). In step S702, when the steering sensor 15 is on or the shuttle lever 35 is not in the forward position (NO in step S702), the control unit 52 returns the process to the main routine. In step S702, when the steering sensor 15 is off and the shuttle lever 35 is in the forward position (YES in step S702), the control unit 52 determines whether or not the position condition flag and the turning angle condition flag are set. Is determined (step S703).

  In step S703, when at least one of the position condition flag and the turning angle condition flag is off (NO in step S703), the control unit 52 returns the process to the main routine, and the position condition flag and the turning angle condition flag are set. When standing together (YES in step S703), the control unit 52 determines whether or not the descending delay operation has timed out (step S704). Here, the descending delay operation is a lengthening operation in which the operator holds the quick up lever 36 in the auto-down execution state and holds it for a predetermined time t2 longer than t1, and the descending delay operation is performed. In the state, as shown in FIG. 18 (d), a temporary pause symbol 51 g is displayed on the warning display portion 51 d, and a temporary pause state is established that restricts the lowering of the rotary tiller 3, and the lowering of the rotary tiller 3 is started. Even if the other conditions are satisfied, the rotary tiller 3 is maintained at the upper limit height position. In the descending delay operation, the descending delay operation is timed out when a predetermined time t3 longer than t2 is exceeded in a state where the operator raises and holds the quick up lever 36. In step S704, when the descending delay operation has timed out (YES in step S704), the control unit 52 sets an auto-down cancel flag as the time-out process, and as shown in FIG. 18C, the warning display unit 51d. Until the predetermined time t4 has elapsed (step S707), and the process returns to the main routine. In step S704, when the descent delay operation has not timed out (NO in step S704), the control unit 52 raises the work implement lowering flag for starting the lowering of the rotary tiller 3 and issues a lowering request (step 706). Return the process to the main routine. In addition, if the operator releases the operation from the quick-up lever 36 within the predetermined time t3 after the descent delay operation, the descent delay operation is canceled, and the descent of the rotary tiller 3 can be started again, and the warning display section 51d. Is displayed as shown in FIG.

<Descent start processing>
FIG. 16 shows a subroutine of a descent start process (step S8) in which the descent of the rotary tiller 3 is started when the lift arm valve 20 is operated based on the descent request. First, the control unit 52 determines whether or not the work implement lowering flag is set (step S801). When the work implement lowering flag is set (NO in step S801), the process returns to the main routine, and the work implement lowering flag is set. When the descent flag is set (YES in step S801), it is determined whether or not a descent delay operation is not performed by the operator (step S802). In step S802, when the downward delay operation is performed by the operator (NO in step S802), the control unit 52 returns the processing to the main routine, and when the downward delay operation is not performed (YES in step S802), the control unit 52 drops the work implement lowering flag (step S803), starts to lower the rotary tiller 3 (step S804), and displays the lowering symbol 51h on the warning display 51d as shown in FIG. 18 (e). The operator is informed that the rotary tiller 3 is descending by sound emission from the notification buzzer 53 (step S805), and the process returns to the main routine.

  The operator continues the forward traveling of the traveling machine body 2 with the rotary tiller 3 started to descend, the power transmission from the PTO shaft to the rotary tiller 3 is resumed, the rotary 3b rotates, and the rotary 3b lands. Then, tillage work is resumed.

<Automatic termination processing>
FIG. 17 shows a subroutine for automatic termination processing for releasing the auto-down execution state based on the travel route of the traveling machine body 2 in the auto-down execution state. As conditions for canceling the auto-down execution state, there are provided an auto-down end condition for the control unit 52 to be in an auto-down off state and an auto-down cancel condition for being in an auto-down cancel state.

  First, the control unit 52 performs a process for an auto-down end position condition that is a first auto-down end condition. In the auto-down execution state, the control unit 52 is defined by X coordinate <−ε1 or ε1 <X coordinate and Y coordinate <−ε1 or ε1 <Y coordinate based on a predetermined end distance ε1. It is determined whether or not the current position is in the end position range that is outside the square to be set (step S901). In step S901, when the current position is in the end position range (YES in step S901), the control unit 52 displays an automatic down control position release display “automatically by position restriction” shown in FIG. ”Is displayed for a predetermined time t4, an automatic end process for setting the control unit 52 to the automatic down-off state is executed (step S902), and the process returns to the main routine. After the predetermined time t4 has elapsed, the control unit 52 displays the engine speed / usage time display shown in FIG. 18A on the notification display unit 51e, and the temperature shown in FIG. 18A on the auto-down state display unit 51a.・ Display the fuel display. As described above, when the auto-down-off condition is entered due to the auto-down termination condition, in order to set the auto-down-on state again, after the auto-down timing volume 33 is once turned to the off position, the control unit 52 is in the work mode. There is no need to change the rotation position of the auto-down timing volume 33 from the off position to the on position again in a state where both the existence and the rotation position of the raising height volume 32 are in the height adjustment position. Must not.

  In step S901, when the current position is not in the end position range (NO in step S901), the control unit 52 determines -ε1 ≦ X coordinate <based on the end distance ε1 and the predetermined notification distance ε2 smaller than the end distance ε1. It is determined whether or not the current position is within the notification position range defined by −ε2, or ε2 <X coordinate ≦ ε1, and −ε1 ≦ Y coordinate <−ε2, or ε2 <Y coordinate ≦ ε1. (Step S903). In step S903, when the current position is in the notification position range (YES in step S903), as the position notification process, the automatic down control position notification display “over position limit” shown in FIG. Is displayed, and the operator is notified of the cancellation of the auto-down execution state (step S904).

  In step S903, when the current position is not in the notification position range (NO in step S903), the control unit 52 determines -ε3 <X <ε3 based on the notification distance ε2 and the predetermined reset distance ε3 that is smaller than the notification distance ε2. In addition, it is determined whether or not the current position is in the end position reset range that is inside the square defined by −ε3 <Y <ε3 (step S905). In step S905, when the current position is within the end position reset range (YES in step S905), the control unit 52 displays the engine speed / number on the notification display unit 51e as shown in FIG. The usage time display is displayed (step S906).

  Next, the control unit 52 performs processing for an auto-down end angle condition that is a second auto-down end condition. The control unit 52 determines whether or not the aircraft angle in the auto-down execution state exceeds a predetermined end angle λ1 (step S907), and when the aircraft angle exceeds the end angle λ1 (YES in step S907). The control unit 52 displays on the notification display unit 51e the auto-down angle release display “turns off automatically when the angle is limited” for a predetermined time t4, and executes an automatic end process for setting the control unit 52 in the auto down-off state. (Step S902), and the process returns to the main routine. After the predetermined time has elapsed, the control unit 52 displays the engine speed / usage time display on the notification display unit 51e and the temperature / fuel display on the auto-down state display unit 51a as shown in FIG.

  When the airframe angle does not exceed the end angle λ1 in step S907 (NO in step S907), the control unit 52 determines that the airframe angle is smaller than the end angle λ1 and the end angle λ1, and a predetermined notification angle λ2. It is determined whether or not the notification angle range defined by λ2 <airframe angle ≦ λ1 is satisfied (step S908). In step S908, when the aircraft angle is within the notification angle range (YES in step S908), an automatic down angle notification display “over angle limit” is displayed on the notification display unit 51e as angle notification processing, and the operator is automatically notified. A notice of the cancellation of the down execution state is given (step S909).

  When the aircraft angle is not in the notification angle range in step S908 (NO in step S908), the control unit 52 determines whether the aircraft angle is less than a predetermined reset angle λ3 that is smaller than the notification angle λ2 ( Step S910). When the airframe angle is less than the reset angle λ3 in step S910 (YES in step S910), the control unit 52 displays the engine speed / number on the notification display unit 51e as shown in FIG. The usage time display is displayed (step S911).

  Next, the control unit 52 performs processing for an automatic end integrated distance condition that is a third auto-down end condition. The control unit 52 determines whether or not the cumulative travel distance from when the auto-down execution state is reached until when the auto-down execution state is reached exceeds the predetermined end cumulative distance ξ1 (step S912). Here, the cumulative travel distance refers to all the travel distances of the airframe reference point 2a from the auto-down execution state until the auto-down execution state disappears, regardless of whether there is forward, reverse, or temporary travel stoppage. The added distance. In step S912, when the accumulated travel distance exceeds the end accumulated distance ξ1 (YES in step S912), the control unit 52 causes the notification display unit 51e to display an auto-down accumulated distance cancel display “automatically with travel limit”. ”Is displayed for a predetermined time t4, the automatic end process for setting the control unit 52 to the automatic down-off state is executed (step S902), and the process is returned to the main routine. After the elapse of the predetermined time t4, the control unit 52 displays the engine speed / usage time display on the notification display unit 51e and the temperature / fuel display on the auto-down state display unit 51a as shown in FIG. 18 (a).

  In step S912, when the integrated travel distance does not exceed the end integrated distance ξ1 (NO in step S912), the control unit 52 is based on a predetermined notification integrated distance ξ2 in which the integrated travel distance is smaller than the end integrated distance ξ1. , Ξ2 <integrated travel distance ≦ ξ1, it is determined whether or not it is within the notification integrated distance range (step S913). In step S913, when the integrated travel distance is in the notification integrated distance range (YES in step S913), the control unit 52 displays the auto-down integrated distance notification display “travel limit exceeded” on the notification display unit 51e as the integrated distance notification process. Is displayed, and the operator is notified of the cancellation of the auto-down execution state (step S914).

  Next, the control unit 52 determines whether or not a canceling forward / backward traveling condition that is an automatic down canceling condition is satisfied (step S915). Here, the establishment of the release forward / reverse travel condition means that the traveling vehicle body is in a state in which the steering sensor 15 is never turned on until the control unit 52 is in the auto-down execution state and is not in the auto-down execution state. When the straight backward movement distance, which is the backward movement distance 2 continuously performed only in the forward / reverse direction, exceeds a predetermined release forward / backward travel distance ρ1 smaller than the reset distance ε3, or the control unit 52 is in the auto down execution state When the steering sensor 15 has not been turned on once, the straight forward travel distance, which is the forward travel distance continuously performed only by forward / reverse travel, exceeds the release forward / backward travel distance ρ1. . In step S915, when the release forward / backward travel condition is satisfied (YES in step S915), the control unit 52 executes an automatic release process, and the notification display unit 51e displays an auto-down integrated distance release display “running restriction”. "Release control" is displayed for a predetermined time t4, an auto-down cancel flag is set (step S916), an auto-down cancel state is entered, and the process returns to the main routine. After the elapse of the predetermined time t4, the control unit 52 displays the engine speed / usage time display on the notification display unit 51e and the temperature / fuel display on the auto-down state display unit 51a as shown in FIG. 18 (a).

  In step S915, when the release forward / backward travel condition is not satisfied (NO in step S915), the control unit 52 determines that the straight backward travel distance or the straight forward travel distance is greater than the release forward / backward travel distance ρ1 and the release forward / backward travel distance ρ1. Based on the small predetermined notification forward / backward travel distance ρ2, it is determined whether or not the notification forward / backward travel range defined by ρ2 <straight forward backward travel distance or straight forward travel distance ≦ ρ1 (step S917). In step S917, when either one of the straight-ahead backward movement distance and the straight-ahead forward movement distance is within the notification forward / backward travel range (YES in step S917), the control unit 52 causes the notification display unit 51e to automatically The down integrated distance notification display “travel limit exceeded” is displayed, the operator is notified of the cancellation of the auto-down execution state (step S918), and the process returns to the main routine.

  In step S917, when both the rectilinear backward travel distance and the rectilinear forward travel distance are not within the notification forward / backward travel range (NO in step S917), the control unit 52 determines whether the rectilinear backward travel distance or the rectilinear forward travel distance is the notification forward / backward travel distance. It is determined whether or not the predetermined reset forward / reverse travel distance ρ3 is smaller than ρ2 and the notification forward / backward travel distance ρ2 (step S919). In step 919, when both the rectilinear backward travel distance and the rectilinear forward travel distance are both less than the reset forward / backward travel distance ρ3 (YES in step S919), a notification display as shown in FIG. The engine speed / usage time display is displayed on the part 51e (step S920), and the process is returned to the main routine.

  In Step S1, control part 52 performs processing about quick up cancellation conditions which are automatic down cancellation conditions. When the operation of lowering the quick up lever 36 for a predetermined time t7 or more is performed in the auto down execution state, the control unit 52 starts to descend the rotary tiller 3, sets the auto down release flag, and enters the auto down release state. . Further, when the raising operation of the quick up lever 36 is performed for less than the predetermined time t2 in the auto-down execution state, the control unit 52 passes the stop symbol 51f shown in FIG. 18C on the warning display unit 51d after the predetermined time t4. Is displayed until the auto-down cancel flag is set and the auto-down cancel state is set.

<Effects of the present embodiment>
As described above, the control unit 52 sets the descent start line on the coordinate system with the turning start position of the traveling machine body 2 as the origin O, and lowers the rotary tiller 3 when the current position of the traveling machine body 2 reaches the lowering start line. Therefore, when the tractor 1 travels back and forth and plows the field H, the operator can select an arbitrary route to turn the traveling machine body 2 and start the descent of the rotary tiller 3. The headland width M from the heel E can be easily aligned. Further, it is possible to prevent an erroneous operation such as an error in the timing at which the operator starts to descend the rotary tiller 3, a formation of an uncultivated portion of the field H, a redundant tillage work, and the like, and an efficient tillage work can be performed.

  In addition, since the traveling machine body 2 includes the liquid crystal display device 51 that can display the direction of the traveling machine body 2 at the current position with respect to the position of the descending start line, the operator operates the traveling machine body 2 to move toward the descending start line. You can know the direction to go. Further, the liquid crystal display device 51 includes a front-rear direction display unit 51b that can display a positional relationship of whether the descent start line is located in front of or behind the traveling machine body 2 at the current position, and the descent start line indicates the current position. Since the left and right direction display portion 51c capable of displaying the positional relationship between the right side and the left side of the traveling machine body 2 at the left side is provided, the operator operates the traveling machine body 2 to move toward the descending start line. It is possible to know the front-rear direction and the left-right direction to be directed.

  Further, since the front-rear direction display unit 51b is provided so as to be able to display that the distance from the traveling machine body 2 to the descending start line is not more than a predetermined value, the operator is close to reaching the descending start line of the traveling machine body 2 You can know whether or not. Further, since the left-right direction display unit 51c is provided so as to be able to display differently depending on the difference in the angle formed between the direction of the traveling aircraft body 2 at the start of turning and the orientation of the traveling aircraft body 2 at the current position, It is possible to know an approximate angle at which the direction of the traveling machine body 2 should be changed in order to go to the descending start line. Moreover, since the left-right direction display part 51c has the some display part 51i provided so that a lighting state and a non-lighting state can each be switched, an operator can distinguish the change of the left-right direction display part 51c at a glance. Can do.

  In addition, when the auto-down execution state is entered, the control unit 52 starts notifying the operator by the short sound of the notification buzzer 53, the aircraft angle is within the turning completion angle range, and the Y coordinate of the aircraft reference point 2a is before the descending start line. When the distance becomes less than or equal to the predetermined distance β, the interval of the short sound of the notification buzzer 53 is shortened, so that the operator can know that it is in the auto-down execution state and know in advance that the descending start line is near Thus, the operator can predict the difference between the tilling restart position by the automatic lowering of the rotary tiller 3 with automatic down control and the tilling restart position desired by the operator.

  Further, in the auto-down release state, the switch from the neutral position to the reverse position of the shuttle lever 35 in the backup mode on state and the rotary tiller 3 not positioned at the upper limit height, the turn-up mode on state In addition, at least one of switching the steering sensor 15 from the off state to the on state and the raising operation of the quick up lever 36 for the predetermined time t1 or more when the rotary tiller 3 is not positioned at the upper limit height. Triggered by the auto-down execution state upon detection of this, and a descent start line is set on the coordinate system with the turning start position as the origin O, it is possible to cope with various turning operation procedures that vary depending on the operator's preference, etc. In addition to improving the degree of freedom of operations to be performed, it reduces the burden on the operator by reducing unnecessary operation procedures. It can be.

  Further, in a state where the machine body angle does not achieve the turning angle condition, the control unit 52 does not lower the rotary cultivator 3 even when the traveling machine body 2 reaches the lowering start line. The descent of the machine 3 can be prevented. Further, since the descending start line is defined only by the front-rear direction coordinates of the airframe reference point 2a at the start of turning, the operator can freely select the horizontal position of the traveling airframe 2 when the work is resumed. For example, tillage work can be performed every other row, so that the degree of freedom of operation can be improved and the processing load on the control unit 52 can be reduced.

  Further, the control unit 52 stores in advance the turning inner periphery and the turning outer periphery in each of the front wheel double speed on 4WD mode, the front wheel double speed off 4WD mode, and the autobrake mode, and the turning inner periphery corresponding to the selected mode. Since the current position is calculated based on the turning periphery, the error between the calculation result of the descent start line due to the difference in these modes and the position where the operator expects the descent start of the rotary tiller 3 is reduced, and The headland width M can be aligned to a predetermined width with high accuracy.

  In addition, the control unit 52 does not enter the auto-down execution state when the two-wheel drive mode unsuitable for the plowing work on the field H or a high speed lower than a predetermined reduction ratio is selected. Unintentional rotary tiller 3 can be prevented from descending. Moreover, since the control part 52 sets a descent | fall start line based on the upper limit height of the rotary tiller 3, and the vehicle speed in an auto down execution state, it takes time until the rotary tiller 3 starts to descend and comes into contact with the ground. It is possible to prevent variations in the ground contact position due to the difference between the headlands and to align the headland width M from the edge with a predetermined width with high accuracy.

  Moreover, since the control part 52 sets a descent | fall start line based on the upper limit height of the rotary tiller 3 adjusted by operation of the raising height volume 32, it grounds after the rotary tiller 3 starts descent | fall. It is possible to prevent variations in the grounding position due to the difference in time required until the headland width M from the edge of the paddle is aligned with a predetermined width with high accuracy. Further, by operating the work implement lowering speed adjustment knob 29, the lowering speed of the rotary tiller 3 by the automatic down control can be adjusted, and the control unit 52 sets the lowering start line based on the lowering speed of the rotary tiller 3. Therefore, the convenience is improved and the variation in the contact position due to the difference in the time required from the rotary tiller 3 to descend to the contact with the ground is prevented, and the headland width M from the heel is increased to a predetermined width. Can be aligned with accuracy. In addition, since the Y coordinate of the descent start line can be adjusted by the automatic down timing volume 33, an error may occur in the descent start line due to slippage of the traveling devices such as the front wheels 5 and the rear wheels 6, For example, it is possible to easily cope with plowing work in a trapezoidal field and the like, improving convenience, and aligning the headland width M from the ridge with a predetermined accuracy with high accuracy.

  In addition, since the lowering of the rotary cultivator 3 can be temporarily suspended by the operation of raising the quick up lever 36 for a predetermined time t2 or longer in the auto-down execution state, the operator can slip the front wheel 5 or the rear wheel 6 When it is predicted that the descent of the rotary cultivator 3 by the automatic down control is started earlier than the timing of the descent desired by the operator due to an erroneous steering operation by the operator, the rotary cultivator 3 The start of descent can be paused temporarily. Further, the operator can know in advance the timing at which the rotary tiller 3 starts to descend by the notice of the short sound interval from t5 to t6 by the notice buzzer 53, and the rotary tiller based on the notice of notice. When it is determined that the timing at which 3 starts to descend is too early, the rotary tiller 3 can be temporarily stopped and the descending of the rotary tiller 3 can be started while visually confirming the work resuming position. . Further, in the auto-down execution state, the auto-down execution state is canceled by a short raising operation of the quick-up lever 36 less than the predetermined time t2, so that the lowering of the rotary tiller 3 can be easily interrupted, and further quick-up is performed. Since the auto-down execution state can be set again by the raising operation of the lever 36, the operator can easily perform turning again and the convenience can be improved.

  Further, the control unit 52 calculates the current position and the aircraft angle of the traveling machine body 2 in the auto-down execution state, and when the traveling machine body 2 is separated from the turning start position by a predetermined distance ε1, the turning angle is determined from 180 ° to a predetermined value. When it is opened more than an angle or when the accumulated travel distance of the traveling machine body 2 exceeds the predetermined distance ξ1, it is in an automatic down-off state. After going out of the field, the rotary tiller 3 can be prevented from descending unintended by the operator.

  Further, when the straight backward movement distance exceeds a predetermined forward / reverse release distance ρ or when the straight forward movement distance exceeds the forward / backward release distance ρ, the control unit 52 executes auto down while maintaining the auto down on state. Since the state is released, it is possible to prevent the rotary tiller 3 from being lowered unintentionally by the operator, and to set the auto-down execution state again with a small number of operations.

  Further, the position of the traveling machine body 2 in the auto-down execution state is calculated by the steering sensor 15 and the vehicle speed sensor 11 that can use an inexpensive contact switch, an optical sensor or the like without using an expensive gyro sensor or GPS. Therefore, cost can be suppressed. In the auto-down control, the current position and the body angle of the traveling machine body 2 are calculated on the basis of the value of the turning radius r that varies depending on the maximum output of the engine and the types and dimensions of the traveling devices such as the front wheels 5 and the rear wheels 6. The control unit 52 can be shared between the traveling bodies 2 having different r. Further, the turning radius r of the traveling machine body 2 is calculated based on whether front wheel double speed control or autobrake control is being executed, and the current position and the aircraft angle of the traveling machine body 2 are calculated based on the turning radius r. The calculation accuracy of the current position of the machine body 2 is improved, and the headland width M from the edge can be aligned with a predetermined width with high accuracy.

  Although the vehicle speed is detected by detecting the rotation of one rear wheel 6 and the rotation of the rear wheel drive shaft, the rotation of other parts may be detected instead. For example, instead of the rotation of the rear wheel drive shaft, The rotation of the drive shaft may be detected, or the rotation of both the left and right rear wheels 6 may be detected. The main transmission mechanism and the sub-transmission mechanism are multi-stage transmission mechanisms. However, if the total reduction ratio, which is the ratio between the engine speed and the rear wheel 6 speed, can be detected, The main transmission mechanism and the sub-transmission mechanism may be stepless transmission mechanisms, or may be configured to include only one of them. In addition, you may add the raising operation of the rotary tiller 3 by operation of the position lever 31 as turning start operation | movement.

  The visual notification to the operator is based on the change of the design and notification text of the liquid crystal display device 51. Alternatively, the display may be an organic EL display other than the liquid crystal or a dot matrix display device of an LED lamp, or light emission. You may alert | report by the change of the color and position of a display apparatus to perform. In addition, the various operation tools for performing input to the control unit 52 may be a touch panel provided in the liquid crystal display device 51 instead, or may be an input device provided outside the traveling machine body 2 capable of wireless communication. There may be. The remote control device that steers the tractor 1 from a place where the operator does not get on may be provided, and the front wheel 5 may be steered by driving the steering device by a motor, hydraulic control, or the like. The steering wheel 13 may be a lever or button that can swing or move horizontally, and the operation of the steering wheel 13 is not limited to detecting either the on state or the off state, and the operation angle can be detected numerically. It is good also as a structure in which the control part 52 can calculate based on the turning radius r calculated according to the operation angle. Note that the operation of the steering wheel 13 may directly detect the rotation of the steering wheel 13, or may be configured to detect the amount of movement of the tie rod or the amount of inclination of the front wheel 5. The control unit 52 may be formed by a discrete circuit or may be integrally formed as a semiconductor integrated circuit element.

  In addition, although the said embodiment demonstrated the tractor 1 provided with the rotary tiller 3, it is not restricted to this, A working machine may be a scraping work machine, a plow, etc., and the operation | work which can be raised / lowered to the traveling machine body 2, such as a rice transplanter, etc. The present invention can be similarly applied to other work vehicles provided with a machine.

1 Working vehicle (tractor)
2 traveling machine body 3 working machine (rotary tiller)
5 Traveling device (front wheel)
6 Traveling device (rear wheel)
16 Lifting device (lifting link mechanism)
51 Display means (liquid crystal display device)
51b Front-rear direction display unit 51c Left-right direction display unit 51i Display unit 52 Control means (control unit)
53 Notification means (notification buzzer)

Claims (7)

In a working vehicle comprising a traveling machine body supported by a traveling device and a lifting device that lifts and lowers the working machine,
A work implement lowering start area is set at the start of turning, and when the traveling machine body completes the turning and reaches the work machine lowering start area, the lifting device can execute the turning control for starting the lowering of the working machine. Control means;
Display means capable of displaying a relationship between the position of the work implement lowering start area in the state where the work implement lowering start area is set and the traveling machine body at the current position;
A working vehicle characterized by that. The display means includes a front-rear direction display unit capable of displaying whether the work implement lowering start area is located in front of or behind the traveling machine body at a current position.
The working vehicle according to claim 1. The front-rear direction display unit is provided so as to be able to display that the distance from the traveling machine body to the work implement lowering start area is not more than a predetermined value.
The working vehicle according to claim 2. The display means includes a left-right direction display unit capable of displaying whether the work implement lowering start region is located on the right side or the left side of the traveling machine body at a current position.
The working vehicle according to any one of claims 1 to 3. The left-right direction display unit is provided to enable different display depending on the difference in angle between the traveling direction of the traveling aircraft body at the start of the turn and the traveling direction of the traveling aircraft body at the current position.
The working vehicle according to claim 4. The left-right direction display unit has a plurality of display units provided to be able to switch between a display state and a non-display state, respectively.
The work vehicle according to claim 4 or 5. Informing means for notifying by sound that the work implement lowering start region is set,
The notification means starts notification that the work implement lowering start area is set by a short sound repeated from the start of turning, and the work implement lowering start area is set. A change in a distance from the current position of the traveling machine body to the work machine descent start region and a change direction of the traveling machine body at the start of the turn and a change in an angle formed by the traveling direction of the traveling machine body at the current position, It is provided so that it can be notified by a change in the interval of the short sound,
The working vehicle according to any one of claims 1 to 6.

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