JP6803227B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle such as a tractor and a passenger rice transplanter, and more particularly to an automatic control of an elevating device for raising and lowering the work machine.

Conventionally, in work such as tilling and planting performed in a field, a work vehicle equipped with automatic control of a turning work machine that operates when turning at the field edge has been proposed (Patent Document 1). In this work vehicle, when the aircraft reaches the field edge and the front wheels are steered, the distance sensor starts to integrate the mileage of the aircraft and the work equipment is raised, and the mileage of the aircraft reaches the set distance. Then, the working device is lowered. Further, conventionally, a riding type seedling transplanter having an automatic turning mode for lowering the work machine when the number of rotations of the rear wheels inside the turning reaches a preset number of times after the start of turning at the field edge has been proposed. (Patent Document 2). This passenger-type 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 predetermined intervals when the calculation of the mileage after the start of turning is started.

Japanese Patent No. 4605622 Japanese Patent No. 5751314

However, in the above-mentioned Patent Documents 1 and 2, if the operator does not drive the work vehicle along a predetermined route when turning at the field edge, the width of the headland from the ridge is set to a predetermined width. It was difficult to align with.

Therefore, according to the present invention, the traveling machine turns at an arbitrary route at the field edge, the working machine is lowered after the turning is completed, and the operator can be instructed in the direction in which the traveling machine should be steered to complete the turning. The purpose is to provide a work vehicle.

The present invention relates to a traveling machine body (2) supported by a traveling device (5, 6), a steering unit (13) for steering the traveling machine body (2), and an elevating device for raising and lowering a working machine (3). In the work vehicle (1) provided with (16) and
The work machine descent start line is set on the coordinate system with the position at the start of turning of the traveling machine (2) as the origin, and the working machine descent start line is reached in the state where the traveling machine (2) has completed turning. Then, the control means (52) capable of executing the turning control for starting the descent of the work machine (3) by the elevating device (16),
A front-rear direction display unit (51b) capable of displaying whether the working machine descent start line is located in front of or behind the traveling machine (2) at the current position, and the traveling machine on the working machine descent start line. (2) Preparations to give a, a display unit (51) having a left-right direction display section (51c), which indicates the lateral direction of the steering unit to be steered (13) in order to reach,
The left-right display unit (51c) should steer the steering unit (13) to the left and the steering unit (13) to the right, indicating that the steering unit (13) should be steered to the left. It has a right display unit, which indicates that
The front-rear direction display unit (51b) is located between the left side display unit and the right side display unit in the left-right direction.
It is characterized by that.

For example, with reference to FIGS. 6, 7 and 18, the front-rear direction display unit (51b) can display that the distance from the traveling machine body (2) to the working machine descent start line is not more than a predetermined distance. It is provided.

For example with reference to FIGS. 6, 7 and 18, the left-side display unit and said right display unit includes a traveling direction of the traveling machine body in a state of complete swivel (2), the traveling machine body at the current position ( It has a plurality of scales (51i) that stepwise indicate the relationship with the traveling direction of 2) .

For example, with reference to FIGS. 7, 8, 9, 10, 10, 11, 12 and 13, the notification means (53) for notifying by sound that the work equipment descending start line is set. )
The notification means (53) starts notifying that the working machine descending start line is set by a short sound repeated from the start of turning, and the working machine descending start line is set. The traveling direction of the traveling machine (2) in the state where the change in the distance from the current position of the traveling machine (2) in the state to the lowering start line of the working machine and the turning are completed, and the traveling machine (2) at the current position. ) Is provided so that the relationship with the traveling direction can be notified by a change in the interval of short sounds.

The reference numerals in parentheses are for comparison with the drawings, but do not limit the configuration of the present invention.

According to the first aspect of the present invention, a working machine descending start line is set at the start of turning, and turning control is executed to start lowering of the working machine when the traveling machine reaches the working machine lowering start line in a state where the turning is completed. Since it is provided with a possible control means and a display means capable of displaying the relationship between the position of the work equipment descent start line and the traveling machine at the current position, the operator can select an arbitrary route at the field edge and select the traveling machine. It is possible to turn, and it is possible to know the direction in which the traveling machine should be steered in order to head toward the work machine descent start line .

Further , since the display means has a front-rear direction display unit capable of displaying whether the work machine lowering start line is located in front of or behind the traveling machine at the current position, the operator can start lowering the work machine. It is possible to know the front-rear direction in which the traveling aircraft should be steered to go to the line . Further, since the display means has a left-right direction display unit indicating the left-right direction of the steering unit to be steered in order for the traveling machine to reach the work machine lowering start line, the operator can start lowering the work machine. You can know the direction in which the traveling aircraft should be steered to go to the line.

According to the second 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 working machine descending start line is not more than a predetermined distance, so that the operator can work on the traveling machine body. It is possible to know whether or not the arrival at the aircraft descent start line is near.

According to the third aspect of the present invention, since the left side display unit and the right side display unit each have a plurality of scales, the operator should generally change the traveling direction of the traveling machine to move toward the work machine descent start line . You can know the angle of.

Furthermore, operator can tell at a glance the change in the horizontal direction display unit.

According to the present invention according to claim 4, operator does not need to keep watching the display means when performing turning of the traveling machine body, it is possible to reduce the operation load of the operator.

The side view which shows the tractor which concerns on this embodiment. The perspective view which shows the rear part of the driving part. A perspective view showing a side panel. Top view showing the side panel. The perspective view which shows the front part of the driving part. The perspective view which shows the front panel. Block diagram of the control unit. The flow diagram which shows the main routine of auto down control. Flow diagram of control state processing. Flow chart of aircraft information acquisition processing. Flow chart of airframe angle processing. Flow diagram of angle calculation. Flow diagram of position calculation. Flow diagram of position flag processing. Flow diagram of position determination processing. Flow chart of descent start processing. Flow diagram of automatic termination processing. It is a figure which shows the content displayed on the liquid crystal display device, (a) is a figure which shows the auto-down release state display, (b) is a figure which shows display at the time of the auto-down execution state, (c) is the figure which shows the auto-down control. The figure which shows the display when the lowering of a rotary tiller is stopped by, (d) is the figure which shows the display when the lowering of a rotary tiller by auto down control is paused, (e) is an auto down A diagram showing a display when the rotary tiller is descending due to control, (f) a diagram showing an auto-down control position notification display, (g) a diagram showing an auto-down control position release display, and (h) a diagram showing an aircraft body. An enlarged view showing the display when the angle is within the first angle range, (i) is an enlarged view showing the display when the aircraft angle is within the second angle range, and (j) is an enlarged view showing the display when the aircraft angle is within the third angle range. An enlarged view showing the display when the inside is inside, (k) is an enlarged view showing the display when the body angle is within the turning completion angle range and the Y coordinate of the traveling machine is out of the predetermined range, (m) is the body angle. Is an enlarged view showing the display when is within the fourth angle range, (n) is an enlarged view showing the display when the aircraft angle is within the fifth angle range, and (p) is an enlarged view showing the display when the aircraft angle is within the turning completion angle range. An enlarged view showing a display when the Y coordinate of the traveling aircraft is within a predetermined range. The schematic diagram which shows the traveling path of a tractor.

<Overall configuration>
Hereinafter, the present embodiment will be described with reference to the drawings. As shown in FIG. 1, the tractor 1 as a work vehicle according to the present embodiment is a work machine having a traveling machine body 2 and a rotating rotary 3b and being vertically connected to the rear portion of the traveling machine body 2. It has a rotary tiller 3. The traveling machine body 2 has a control unit 52 as a 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. The front wheels 5 and the rear wheels 6 are arranged on the left and right sides and provided in pairs, and the traveling aircraft 2 is steered by steering the front wheels 5 to the left and right. Further, the traveling machine body 2 has a body frame 7 supported by the front wheels 5 and the rear wheels 6, and a driving unit 10 having a driver's seat 23 on which the operator rides. In the present embodiment, unless otherwise specified, the front direction toward which the operator seated on the driver's seat 23 of the tractor 1 placed on the horizontal plane faces is the front direction, which is the direction of the traveling machine body 2. Define the front-back and left-right directions based on. On the output side of the control unit 52, a notification buzzer 53 is provided as a notification means capable of transmitting various information to the operator by sound emission, and operates by the output signal from the control unit 52.

<Power transmission structure>
The fuselage frame 7 is a mission (not shown) arranged between 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 the left and right rear wheels 6. It has a case and.

Inside the transmission case, a traveling transmission (not shown) that shifts the power of the engine is housed. The traveling transmission has a main transmission mechanism (not shown) that shifts the power of the engine in multiple stages and a main transmission mechanism. An auxiliary transmission mechanism (not shown) for shifting the power in multiple stages and a PTO transmission mechanism (not shown) for shifting the power to the PTO shaft (not shown) are incorporated. The rotation of the PTO shaft is transmitted to the rotary tiller 3, and the rotary 3b rotates around the rotary shaft 3a to cultivate the field.

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

Power via the main transmission mechanism and the auxiliary transmission mechanism is distributed to the left and right rear wheels 6 by a rear wheel drive shaft (not shown) via a rear wheel differential mechanism (not shown), and the front wheel transmission mechanism (not shown) and the front wheel drive shaft (not shown) are distributed. It is distributed to the left and right front wheels 5 via a front wheel differential mechanism (not shown), and allows a difference in the number of rotations of the inner and outer wheels when the traveling machine body 2 turns left and right by steering the front wheels 5 so as to be smooth. It is configured so that it can run smoothly.

The rear wheel differential mechanism transmits power from the rear wheel drive shafts to the left and right rear wheels 6 via a pair of left and right brake mechanisms (not shown) capable of independently braking the left and right rear wheels 6. 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 per unit time of the rear wheel drive shaft and either the left or right rear wheel 6. The vehicle speed of the traveling machine 2 is calculated based on the number of rotations of. Here, as shown in FIG. 19, the vehicle speed is the moving distance per unit time of the aircraft reference point 2a, which is the center point of the left and right rear wheels 6 on the rotation axis of the rear wheels 6. The vehicle speed information at the calculated time point is transmitted to the control unit 52 by an electric signal. Further, the control unit 52 integrates the vehicle speed with time to obtain the moving distance of the aircraft reference point 2a, that is, the traveling distance of the traveling aircraft 2.

The front wheel transmission mechanism is provided with a friction multi-plate type hydraulic clutch (not shown), and when the hydraulic clutch is engaged and disconnected, the traveling machine body 2 makes the average peripheral speeds of the left and right front wheels 5 relative to the average peripheral speeds of the left and right rear wheels 6. Front wheel double speed on 4WD mode in which front wheel double speed control is executed to increase speed, and front wheel double speed off 4WD in which the average peripheral speed of the left and right front wheels 5 is driven at approximately 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 switchable.

<Steering device>
A steering device 12 is arranged on the airframe frame 7. The steering device 12 includes a steering wheel 13 that is rotated by an operator to steer the front wheels 5, a steering column 14 shown in FIG. 6 that rotates integrally with the steering wheel 13, and a steering column 14 that extends to the left and right. It has a steering mechanism (not shown) that converts the rotation of the steering wheel into a substantially linear motion in the left-right direction, and a tie rod (not shown) that connects both ends of the steering mechanism and the left and right front wheels 5. When the operator rotates the steering wheel 13, the steering column 14 rotates, and the tie rods move left and right based on the rotation angle and rotation direction of the steering column 14, and the left and right front wheels 5 are steered.

The steering device 12 is provided with stoppers (not shown) that restrict the rotation of the steering wheel 13 in one direction by a predetermined amount or more 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 in which 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 rotated from the neutral position by a predetermined angle α2 or more slightly smaller than the maximum rotation angle α1, the steering sensor 15 shown in FIG. 7 is turned on and the steering wheel 13 is rotated by α2 or more. And the rotation direction of the steering wheel 13 is detected. Further, when the rotation 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 rotation 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 electric signal.

<Elevating link mechanism>
At the rear of the traveling machine body 2, the machine body frame 7 and the rotary cultivator 3 are connected, and a lifting link mechanism 16 as a lifting device for raising and lowering the rotary cultivator 3 is provided. The elevating link mechanism 16 includes a link bracket (not shown) projecting from the rear portion of the traveling machine body 2, a top link 17 that is pivotally supported so as to swing up and down with respect to the link bracket and extends rearward, and a top. It has a pair of left and right lower links 18 that are provided below the link and are axially supported and extend rearward with respect to the link bracket, and the top link 17 and the rear ends of the left and right lower links 18 , A three-point link mechanism is formed by being pivotally supported by the rotary tiller 3 so as to swing up and down. 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 front end of the lift arm is pivotally supported by the link bracket so that it can swing up and down, and the lower link 18 swings up and down as the lift arm swings up and down as the lift arm cylinder expands and contracts, and the rotary tiller 3 goes up and down. The swing angle of the lift arm is detected by the lift arm sensor 21 provided on the lift arm and shown in FIG. 7, and is transmitted to the control unit 52 by an electric signal.

<Driving unit>
Next, the operation unit 10 will be described with reference to FIG. On the left side of the driver's seat 23, there is an auxiliary transmission lever 27 that is swingably supported to shift the auxiliary transmission mechanism, and below the driver's seat 23, a rotary tiller 3 is lowered by being rotatably supported. A work equipment descent speed adjusting knob 29 capable of operating a descent speed adjusting valve (not shown) for adjusting the speed is provided. The auxiliary shift lever 27 is operably provided at three shift positions of high speed, medium speed, and low speed, and when the shift position of the auxiliary shift lever 27 is located at the high speed, the engine speed is increased. The reduction ratio divided by the rotation speed of the wheel drive shaft is the smallest of the three stages, the low speed stage has the largest reduction ratio, and the medium speed stage has a reduction ratio between the high speed stage and the low speed stage. ing. Further, when the working machine lowering speed adjusting knob 29 is rotated clockwise by the operator, the lowering speed adjusting valve is operated to reduce the lowering speed of the rotary cultivator 3 and rotate it counterclockwise. And the descending speed increases. Information on the shift position of the auxiliary shift lever 27 and information on the rotation position of the work equipment descending speed adjusting knob 29 are transmitted to the control unit 52 by an electric signal.

<Side panel>
As shown in FIGS. 2, 3 and 4, a side panel 26 on which various operating tools and lamps are arranged is provided on the right side of the driver's seat 23. On the side panel 26, a main speed change lever 30 that is swingably supported to shift the main speed change mechanism, a position lever 31 that raises and lowers the rotary cultivator 3, and a raising that sets the maximum rising height of the rotary cultivator 3 are set. The height volume 32 and the auto down timing volume 33 are arranged.

The shift operation of the main shift mechanism by the main shift lever 30 can be performed independently of the shift operation of the auxiliary shift mechanism by the auxiliary shift lever 27, and the shift position and power of 8 steps from 8 steps to 1 step can be changed. It is operably provided at a neutral position that does not transmit to the front wheels 5 and the rear wheels 6 and at an accelerator shift position that automatically shifts from 8 to 4 steps by operating an accelerator pedal (not shown). The eight gears have the smallest reduction ratio due to the main transmission mechanism, and the 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 electric signal.

The position lever 31 is supported so as to be swingable back and forth, and is configured to hold the swing position when the operator releases the operation hand. When the position lever 31 is swung back and forth, the rotary cultivator 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 electric signal.

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

The auto-down timing volume 33 is rotatably supported, and is mutably provided between an on position and an off position provided in a predetermined rotation range. Auto-down timing When the rotation position of the volume 33 is in the on position, the lowering start timing of the rotary cultivator 3 can be adjusted in accordance with the rotation position in the 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 electric signal. Further, the side panel 26 is provided with an automatic on lamp 48, and the automatic on lamp 48 is turned off when the auto down timing volume 33 is in the off position and is turned off when the auto down timing volume 33 is in the on position. Lights or blinks when the auto-down permission condition described later is satisfied or not satisfied.

<Around the steering wheel>
As shown in FIG. 5, a steering wheel 13 is arranged in front of the driver's seat 23, and a brake pedal 25 and an accelerator pedal for operating the left and right brake mechanisms are arranged below the steering wheel 13. Around the wheel 13, there is a starter switch 34 which is the main switch of the traveling machine 2, a shuttle lever 35 which the operator switches between forward and reverse of the traveling machine 2, and a preset upper limit height and lower limit height. A quick-up lever 36 for raising and lowering the rotary tiller 3 is arranged.

The shuttle lever 35 is operably provided in the forward position, the neutral position, and the reverse position. When the shuttle lever 35 is in the forward position, the traveling aircraft 2 advances, and when the shuttle lever 35 is in the neutral position, the traveling aircraft 2 moves forward. The traveling is stopped, and when the vehicle is in the reverse position, the traveling aircraft 2 moves backward. Information on the operating position of the shuttle lever 35 is transmitted to the control unit 52 by an electric signal.

The quick-up lever 36 is swingably supported between the raising position, the center position, and the lowering position, and is operated after the operator raises the quick-up lever 36 to the raising position or lowers it to the lowering position. An urging member (not shown) is provided so that the lever returns to the central position when the lever is released. When the quick-up lever 36 is short-raised while the rotary cultivator 3 is stopped, the rotary cultivator 3 rises to the upper limit height, and when the rotary cultivator 3 is short-lowered, the rotary cultivator 3 has the lower limit height. It descends to a height corresponding to the swing position of the position lever 31. The operation direction and operation time of the quick-up lever 36 are transmitted to the control unit 52 by an electric signal.

<Front panel>
As shown in FIG. 6, a front panel 24 having various operating tools, a display device, and a lamp is arranged in front of the steering wheel 13. The front panel 24 includes a backup changeover switch 37 for switching between an on state and an off state of the backup mode of the traveling machine body 2, and a turn-up changeover switch 39 for switching between an on state and an off state of the turn-up mode. When the traveling machine 2 is in the backup mode on, the backup lamp 40 is lit, and the shuttle lever 35 is switched from the neutral position to the reverse position while the rotary cultivator 3 is not located at the upper limit height. When this is done, the rotary cultivator 3 rises to the upper limit height. When the turning up mode is on, the turning up lamp 41 lights up, and when the steering sensor 15 is switched from the off state to the on state while the rotary cultivator 3 is not located at the upper limit height, the rotary cultivator 3 is turned on. It rises to the upper limit height. The switching information of the backup changeover switch 37 and the turn-up changeover switch 39 is transmitted to the control unit 52 by an electric signal.

Further, the front panel 24 includes a 4WD changeover switch 42 for engaging and disengaging the hydraulic clutch, and a turning double speed changeover switch 43 for performing the disconnection and disconnection operation of the hydraulic clutch and the braking operation by the brake mechanism. Each time the operator operates the 4WD changeover switch 42, the traveling machine body 2 switches between a 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 mode transmits power to the front wheels 5. In the mode, the 4WD switching lamp 45 lights up. Information on the switching operation by the 4WD changeover switch 42 and the turning double speed changeover switch 43 is transmitted to the control unit 52 by an electric signal.

While the 4WD changeover lamp 45 is lit, each time the turning double speed changeover switch 43 is operated, the traveling machine 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 lights up, and in the autobrake mode, the front wheel double speed control is executed and the rear wheel 6 inside the turning is automatically braked by the control unit 52. Is executed, and the autobrake turning lamp 47 lights up.

The front panel 24 has an automatic changeover switch 49 that can switch between a work mode for the traveling machine 2 to perform tilling work in the field and a running mode for traveling on the road or the like outside the field, and the traveling machine 2 is a work mode. It is provided with an automatic switching lamp 50 that indicates which of the driving modes is used. Each time the operator operates the Omakase changeover switch 49, the work mode and the travel mode of the traveling machine 2 are alternately switched. When the traveling machine 2 switches from the working 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 autobrake mode is set, the front wheel double speed off 4WD mode is set. When in the drive mode, the 2 drive mode is maintained, the raising and lowering of the rotary tiller 3 by the quick-up lever 36 is restricted, and when the main shift lever 30 is in the accelerator shift position, the accelerator pedal is operated. As a result, the speed change operation of the main speed change mechanism becomes possible. When the traveling machine 2 switches from the traveling mode to the working mode, it changes to one of the backup mode, the turning up mode, the front wheel double speed on 4WD mode, the autobrake mode and the 2WD mode before switching from the working mode to the driving mode. As a result, the rotary cultivator 3 can be raised and lowered by the quick-up lever 36, and the shift operation of the main transmission mechanism by the operation of the accelerator pedal is restricted. Information on switching between the work mode and the traveling mode by the automatic changeover switch 49 is transmitted to the control unit 52 by an electric signal.

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

<Block diagram>
FIG. 7 shows a control block diagram according to the present embodiment, and the control unit 52 capable of executing the 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 shift lever 30, an auxiliary shift lever 27, a position lever 31, an automatic changeover switch 49, an auto-down timing volume 33, and an increase height. Micros based on signals input from the volume 32, shuttle lever 35, swivel double speed changeover switch 43, 4WD changeover switch 42, backup changeover switch 37, turn up changeover switch 39, work equipment descent speed adjustment knob 29, and starter switch 34. A signal is output by the calculation of the computer 52a to operate the lift arm valve 20 and the notification buzzer 53, 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 lamp 41, and the backup. The lighting and extinguishing of the lamp 40, the autobrake turning lamp 47 and the automatic on lamp 48 are controlled, and various information is displayed on the liquid crystal display device 51.

<Auto down control>
Next, regarding the auto-down control as the turning control executed by the control unit 52, the flowcharts of FIGS. 8 to 17, the notification contents by the liquid crystal display device 51 of FIG. 18, and an example of the traveling path of the tractor 1 in the tilling work of the field H. This will be described with reference to a schematic diagram of FIG. In the auto-down control, the tractor 1 that has reached the field edge J raises the rotary cultivator 3 in the cultivating work of the field H, which is performed while the traveling machine 2 repeatedly travels straight and turns at the field edge J to reciprocate. This is a control that automatically starts the descent of the rotary cultivator 3 when the descent start line as the boundary of the work machine descent start area is reached after the turning.

<Main routine>
FIG. 8 is a flowchart showing the main routine of the auto down control. When the operator turns on the starter switch 34, the main routine is started, and as shown in FIG. 18A, the liquid crystal display device 51 shows the temperature / fuel display of the auto-down state display unit 51a and the notification display unit 51e. The auto-down release status display, which consists of the 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 tillage work while reciprocating in the field H in the directions of the path L1 and the path L2 shown in FIG. Specifically, for example, the work of bringing the right end or the left end of the rotary tiller 3 close to the ridge E and traveling along the ridge E to mark the width of the tillage by the rotary cultivator 3. ..

Next, the operator makes various settings as a preliminary preparation for the tillage work. First, the Omakase changeover switch 49 is operated to set the traveling machine body 2 to the work mode, and after adjusting the rotation position of the raised height volume 32 to the raised height adjustment position, the rotating position of the auto down timing volume 33 By changing the position 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 auto brake mode, and shifts the main shift lever 30 and the auxiliary shift lever 27. By operating and setting the total reduction ratio determined by the combination of the shift stage by the main transmission mechanism and the shift stage by the auxiliary transmission mechanism to a state larger than the predetermined auto down reduction ratio, the auto down permission condition is satisfied and automatic. The on lamp 48 lights up. In addition, the operator keeps the traveling aircraft 2 in the turning-up mode or the backup mode on by operating the turning-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 is a switching from the neutral position of the shuttle lever 35 to the reverse position in the state where the backup mode is on and the rotary cultivator 3 is not located at the upper limit height, and the turning up mode is on. In addition, when the rotary cultivator 3 is not located 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 shortened by a predetermined time t1 or more when the rotary cultivator 3 is stopped ascending / descending. It is a raising operation.

The operator aligns 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 edge J along the path L1. When the traveling machine 2 approaches the field edge J, the operator continues the tilling work while visually confirming 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, the auto-down start flag is set.

In the present embodiment, the routes L1, T, and L2 shown in FIG. 19 will be described, but the traveling route at the time of turning at the field edge J is not limited to this, and for example, the traveling aircraft 2 reaches the ridge E. After that, the operator may rotate the steering wheel 13 clockwise by α2 or more, and while the backup mode is on, the traveling aircraft 2 may be turned while moving backward to align the direction of the traveling aircraft 2 with the path L2. Further, when the rotary shaft 3a reaches the work boundary C at the field edge J, the operator rotates the steering wheel 13 counterclockwise by α2 or more to move the traveling machine body 2 forward and turn it approximately 90 ° to the left. With the rotation angle of the steering wheel 13 returned to the neutral position, the traveling machine body 2 is moved straight forward and backward to an appropriate position, and then the steering wheel 13 is rotated counterclockwise by α2 or more and moved forward to the left. The direction of the traveling machine 2 may be aligned with the path L2 by turning 90 °.

<Control state processing>
Next, the control unit 52 performs a control state process (step S2) for determining whether or not to permit execution of a process for calculating the current position of the traveling aircraft 2 and the descending start line. FIG. 9 shows a subroutine of control state processing (step S2). When the control state processing (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 the 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 for calculating the position of the traveling aircraft 2 during turning, the descent start line, and the like, and is in the auto-down on state. For the sake of convenience, the state in which the auto-down execution flag is set is called the auto-down release state. When the auto-down execution flag is set (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 set (NO in step S203), the control unit 52 returns the process to the main routine, and when the auto-down start flag is set (YES in step S203), control is performed. The unit 52 lowers the auto-down start flag (step S204), and determines whether or not the auto-down permission condition is satisfied (step S205).

When the auto-down permission condition is not satisfied (NO in step S205), the control unit 52 returns the process to the main routine, and when the auto-down permission condition is satisfied (YES in step S205), the control unit 52 returns. , The auto-down execution flag is set to enter the auto-down execution state, and the front-rear direction display unit 51b, the left-right direction display unit 51c, and the warning display unit 51d are formed on the auto-down state display unit 51a, and the warning display unit 51d is shown in the figure. The contents shown in 18 (b) are displayed on the front-rear direction display unit 51b and the left-right direction display unit 51c with the design shown in FIG. 18 (h), and the notification buzzer 53 is repeatedly notified by a short sound at intervals of a predetermined time t5. Is started (step S206), and the process is returned to the main routine. Here, the time when the state where the auto-down execution flag is set changes to the state where the auto-down execution flag is set is referred to as a turning start time. Further, the front-rear direction display unit 51b and the left-right direction display unit 51c are displayed in FIGS. 18 (h) to 18 (p) based on the results from the aircraft information acquisition process (step S3) to the position flag process (step S10), which will be described later. One of the symbols shown in 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), and the auto-down permission condition is set. When it is not satisfied (NO in step S207), that is, the traveling machine 2 has once performed turning or tilling work in the auto-down execution state, but for some reason, the auto-down permission condition is not satisfied. At that time, the control unit 52 blinks the automatic on lamp 48 to notify the operator that the auto down permission condition is not satisfied (step S208), and as an auto down reset process, an auto down execution flag and an auto down start flag. (Step S210), and the auto-down is released. This may be the case, for example, when the operator operates the Omakase changeover switch 49 to switch the traveling machine body 2 from the working mode to the traveling mode when the tilling work is completed.

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

<Aircraft information acquisition process>
FIG. 10 is an aircraft information acquisition process (step S3) in which information such as the type and setting of the tractor is read, and the descending reference line F, which is a reference for determining the descending start line, is calculated based on the position of the traveling aircraft 2 at the start of turning. ) Subroutine is shown. When the aircraft information acquisition process is started, the control unit 52 reads the maximum engine output (step S301) stored in advance in the control unit 52 to acquire the horsepower setting, and the front wheels 5 and the rear wheels to acquire the tire settings. The type and dimensions of the traveling device including 6 mag are read (step S302). Types of traveling devices include a pair of front wheels 5 and a pair of rear wheels 6, a pair of front wheels 5 and a pair of crawlers and a pair of crawlers, and the dimensions of the traveling device include the length of the crawlers or the front wheels 5. There is a distance between the axes with the rear wheel 6, a distance between the left and right traveling devices, and the like. Therefore, the traveling device is not limited to the present embodiment, and may be a combination of the front wheels 5 and the crawler, or may be 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 the turning inner circumference and the turning outer circumference corresponding to various combinations of the results of steps S301, step S302, and step S303, and the control unit 52 has the turning inside corresponding to the combination of the above results. The circumference and the turning circumference are read (step S304). Here, the turning inner circumference and the turning outer circumference refer to the rear wheels 6 inside and outside the turning when the traveling machine body 2 turns 360 ° in a state where the steering wheel 13 is rotated to either the left or right maximum rotation angle. The distance traveled by.

Next, the control unit 52 calculates the turning circumference, which is the average value of the turning inner circumference and the turning outer circumference, based on the turning inner circumference and the turning outer circumference read in step S304 (step S305), and based on this turning circumference. To calculate the turning radius r (step S306). The turning radius r is the radius of the arc locus drawn by the machine reference point 2a when the traveling machine body 2 turns in a state where the steering wheel 13 is rotated to either the left or right maximum rotation angle, and the turning radius r is the turning circumference. It is calculated by dividing by twice the circumference ratio.

Next, the control unit 52 reads the hitch length A, which is the distance in the plan view between the rotation shaft of the rear wheel 6 and the rotary shaft 3a at the time of landing of the rotary 3b, which is stored in advance in the control unit 52 (step S307). ), The vehicle speed measured by the vehicle speed sensor 11 is read (step S308), the rotation position of the dashing height, the raising height volume 32, and the rotating position of the work equipment lowering speed adjusting knob 29 are read, and based on the vehicle speed. The descent mileage D in which the aircraft reference point 2a moves from the start of descent of the rotary cultivator 3 to the landing is calculated (step S309). Here, the dashing height is the descending speed after the rotary cultivator 3 has descended to a predetermined height so that the traveling machine 2 does not suddenly accelerate due to the rotational force of the rotary 3b when the rotary 3b touches the ground while rotating. It is the height that becomes the change point of the descent speed that is set in advance when it is reduced and slowly grounded.

As shown in FIG. 19, the control unit 52 has the position of the aircraft reference point 2a at the start of turning, that is, the turning start position as the origin O, and the horizontal axis X which is the rotation axis of the rear wheels 6 at this time. And, a two-dimensional orthogonal coordinate system with a vertical axis Y with the rear side of the traveling aircraft 2 at the start of turning as a positive direction is set by passing through the origin O while being orthogonal to the horizontal axis X, and the aircraft information acquisition process (step S3). ) Is performed, and a descending reference line F defined only by the Y coordinate and used as a reference for calculating the descending start line is set on the coordinate system based on the results of steps S307 to S309 (step S310). Further, the position of the traveling aircraft 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 aircraft reference point 2a.

The position of the rotary shaft 3a of the rotary cultivator 3 that landed after the turn coincides with the work boundary C that is the position of the rotary shaft 3a of the rotary cultivator 3 in the landed state at the start of the turn, that is, the running at the start of the turn. The rotary cultivator 3 lands at the work restart position G where the Y coordinate of the aircraft reference point 2a is equal to twice the hitch length A while the orientation of the aircraft 2 and the orientation of the traveling aircraft 2 after turning are opposite. Then, when the cultivating work is resumed, the cultivating work can be performed by aligning the headland width M from the ridge E. When the traveling aircraft 2 is traveling along the route L2 and the descending starts before the descending mileage D from the work restart position G, the traveling aircraft 2 travels when the traveling aircraft 2 turns at the field edge J. The tilling work can be restarted from the work restart position G without stopping. In this case, the Y coordinate obtained by subtracting the descending mileage D from the Y coordinate of the work restart position G becomes the Y coordinate of the descending reference line F. When the control unit 52 calculates the descending reference line F, the control unit 52 returns the process to the main routine. Further, the operator adjusts the Y coordinate of the position where the rotary cultivator 3 starts descending with respect to the descending reference line F by operating the auto-down timing volume 33 from the minimum −S using S which is a predetermined length. It is possible to set a descending setting line adjusted in the range of maximum + S.

<Aircraft angle processing>
FIG. 11 shows a subroutine of the aircraft angle processing (step S4) that calculates the change in the direction of the traveling aircraft 2 in the auto-down execution state and determines the completion of turning based on the calculation result. The control unit 52 determines whether or not all of the conditions that the auto-down execution flag is set, the vehicle speed of the traveling body 2 is other than 0, and the steering sensor 15 is on (step S401) are satisfied, and all of them are satisfied. When (YES in step S401), the change in the direction of the traveling aircraft 2 in the minute time dt, that is, the amount of angle change is calculated based on the vehicle speed and the turning radius r (step S403), the amount of angle change is accumulated, and the turning is started. The aircraft angle, which is the angle formed by the orientation 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). In step S401, when any of the above conditions is not satisfied (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 axis to the rotary cultivator 3 is cut off, the rotary cultivator 3 rises to the upper limit height, and the auto down on state and the auto down start condition are satisfied. When all the auto-down permission conditions are satisfied, the auto-down execution state is set, and the calculation of the position and orientation of the traveling machine 2 in the field H is started. At this time, the notification buzzer 53 starts notification by a short sound repeated at intervals of a predetermined time t5, and the warning display unit 51d displays the auto-down caution display “AUTODOWN / descent caution” shown in FIG. 18 (b). The design of FIG. 18H is 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 the arcuate path T whose radius is the turning radius r.

Next, the control unit 52 determines whether or not the airframe angle is 90 ° or more (step S405), and when the airframe angle is less than 90 ° (NO in step S405), the control unit 52 does not reach the turn. If it is judged to be in a state and the aircraft angle is less than 20 °, the front-rear direction display unit 51b and the left-right direction display unit 51c are displayed with the design shown in FIG. The symbol shown in FIG. 18 (i) is displayed on the 51b and the left-right direction display unit 51c (step S406), and the process is returned to the main routine. The left-right direction display unit 51c has a rectangular display unit 51i that can switch 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. Three pieces are arranged in the left-right direction on each of the left and right sides of the part 51b, and when the display part 51i in the display state is displayed only on the right side, the operator rotates the steering wheel 13 clockwise. Running 2 means that the descent start line can be approached. Further, when the symbol displayed on the front-rear direction display unit 51b is in the direction 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 on 51b is in the direction shown in FIG. 18J, it means that the descending start line is in front of the traveling machine body 2. The operator continues to turn the traveling machine body 2 along the path 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 machine body angle is 90 ° or more (YES in step S405), the control unit 52 determines that the turning state has been completed (step S407), and determines whether or not the turning angle condition is satisfied. (Step S408). Achievement of the turning angle condition means that the aircraft angle is within a predetermined turning completion angle range in which it is determined that the turning is completed. The turning completion angle range is 180 ° after the aircraft angle changes from outside the range of 180 ° ± α3 to within the range of 180 ° ± α3 using the predetermined angles α3 and α4 where α3 <α4. ° ± α4, and after the aircraft angle changes from within the range of 180 ° ± α4 to outside the range of 180 ° ± α4, the turning completion angle range becomes 180 ° ± α3. In this way, by changing the turning completion angle range depending on whether or not the aircraft angle is within the turning completion angle range, the processing is frequently switched when the aircraft angle is near the upper limit or the lower limit of the turning 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 is 270 ° or less, 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 more than 270 ° and less than 300 °, the design shown in FIG. 18 (n) is displayed on the front-rear direction display unit 51b and the left-right direction display unit 51c, and the turning angle condition flag is turned off ( 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 has the coordinates of the aircraft reference point 2a at the time of calculation on the coordinate system, that is, the Y coordinate of the current position is the descending start line. When the distance is within a predetermined distance in the minus direction from the above, the design shown in FIG. 18 (p) in which the front-rear direction display unit 51b and the front-rear direction display unit 51b adjacent to the left and right display units 51i are both displayed is displayed. The interval of short sounds by the notification buzzer 53 is changed to t6, which is shorter than t5, to notify the operator that the descent start line is near, and in cases other than the above, the front-rear direction display unit 51b and the left-right direction display are displayed. The symbol shown in FIG. 18K is displayed on the unit 51c, the turning angle condition flag is set (step S410), and the process is returned to the main routine.

The operator confirms that the design shown in FIG. 18 (k) is displayed on the left-right direction display unit 51c, returns the steering wheel 13 to the neutral position, and displays the design shown in FIG. 18 (p) on the left-right direction display unit 51c. The traveling aircraft 2 is driven straight along the route L2 in parallel with the route L1 until it is displayed.

<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 machine body angle, and the vehicle speed (step S501), and changes the position of the traveling machine body 2 on the coordinate system in the minute time dt based on the angle change amount, the machine body angle, and the vehicle speed, that is, The amount of coordinate change is calculated (step S502). Next, the control unit 52 determines whether or not the vehicle speed of the traveling machine 2 is other than 0 (step S503), and when the vehicle speed is 0 (YES in step S503), the control unit 52 maintains the current position (step). S504) The process is returned to the main routine, and when the vehicle speed is other than 0 (NO in step S503), the coordinate change amount is accumulated at the current position to calculate a new current position (step S505), and the process is performed in the main routine. Return to.

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

In the auto-down execution state, the control unit 52 starts descending when the Y coordinate of the descending reference line F exceeds the Y coordinate of the descending 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 is returned to the main routine. In the auto-down execution state, when the Y coordinate of the current position exceeds the Y coordinate of the descending setting line and is less than the Y coordinate of the descending reference line F (NO in step S607), the steering sensor It is determined whether or not 15 is in the ON state or the shuttle lever 35 is located in the reverse position (step S609). When the steering sensor 15 is on or the shuttle lever 35 is in the reverse position (YES in step S609), the control unit 52 sets a predetermined hysteresis value at the Y coordinate of the current position as the Y coordinate of the descending start line. The value to which γ is added is adopted (step S610), and the process is returned to the main routine. In step S609, when neither the steering sensor 15 is on nor the shuttle lever 35 is in the reverse position (NO in step S609), the process is returned to the main routine. As described above, in the auto-down execution state, the state in which the descending start line is set is maintained while the Y coordinate of the descending start line changes with the change of the current position and the Y coordinate of the descending setting line.

The operator travels forward while traveling the traveling aircraft 2 straight along the route L2, 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 show FIG. The symbol shown in (p) is displayed, and it is confirmed that the interval between the short sounds of the notification buzzer 53 has become smaller, and it is known that the rotary tiller 3 is about to start descending.

<Position flag processing>
Even when the current position reaches the descent start line, the traveling aircraft 2 will move when the aircraft angle deviates significantly from the path L2, when the steering sensor 15 is on, and when the traveling aircraft 2 is moving backward. It is not determined that the descent start line has been properly reached, and the descent of the rotary cultivator 3 is not started. FIG. 14 shows a subroutine of position flag processing (step S10) for determining whether or not the position condition for determining that the traveling aircraft 2 has properly reached the descent 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 lowers the position condition flag and sets the position passing condition flag (YES in step S11). 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 the descent flag to start the descent of the rotary tiller 3 in the position determination process described in detail later, and the current position is set to the descent start line. It is a flag indicating that it has been reached. Further, the position passing condition flag is a flag indicating that the current position has reached the descending start line, but the conditions for descending the rotary cultivator 3 have not been met and the vehicle has passed the descending start line.

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 descending start line (NO in step S11), the control unit 52 determines that the Y coordinate of the current position is the descending 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 of (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 passing condition flag. Both are dropped (step S13), and the process is returned 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 descending start line (NO in step S12), the control unit 52 determines whether or not the position passing condition flag is set. (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 dropped. When the cage (NO in step S15) and 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 the position condition flag (step S18). In step S16, when the Y coordinate of the current position is equal to or greater than the Y coordinate of the descending start line (NO in step S16), and in step S17, when the Y coordinate of the current position is equal to or less than the Y coordinate of the descending start line (NO). NO) in step S17, the control unit 52 returns the process to the main routine.

<Position judgment processing>
FIG. 15 shows a subroutine of the position determination process (step S7) that issues a lowering request for the rotary cultivator 3 based on the result of the position flag process (step S10). First, the control unit 52 determines whether or not the vehicle speed is other than 0 (step S701), returns the process to the main routine when the vehicle speed is 0 (NO in step S701), and returns the process to the main routine when the vehicle speed is not 0 (step S701). YES) determines whether or not the steering sensor 15 is in the off state and the shuttle lever 35 is located in 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 in the off state 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 set (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 descent delay operation is a long-up operation in which the operator holds the quick-up lever 36 for a predetermined time t2 or more longer than t1 in the auto-down execution state, and the descent delay operation is performed. In the state, as shown in FIG. 18D, the temporary pause symbol 51g is displayed on the warning display unit 51d, the rotary cultivator 3 is in a temporary pause state for restricting the descent, and the rotary cultivator 3 starts descending. The position of the upper limit height of the rotary cultivator 3 is maintained even if other conditions are satisfied. In the descent delay operation, when the operator holds the quick-up lever 36 for a long time and exceeds a predetermined time t3 longer than t2, the descent delay operation times out. When the descending delay operation is timed out in step S704 (YES in step S704), the control unit 52 sets an auto-down release flag as a time-out process, and as shown in FIG. 18C, the warning display unit 51d The stop symbol 51f is displayed until the predetermined time t4 elapses (step S707), and the process is returned to the main routine. In step S704, when the descent delay operation has not timed out (NO in step S704), the control unit 52 sets a working machine descent flag to start descent of the rotary cultivator 3 and issues a descent request (step 706). , Return the process to the main routine. Further, if the operator releases the operation from the quick-up lever 36 within a predetermined time t3 after the descent delay operation, the descent delay operation is canceled and the rotary cultivator 3 can be started to descend again, and the warning display unit 51d Is the display shown in FIG. 18 (b).

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

The operator continues the forward traveling of the traveling machine 2 with the rotary cultivator 3 started to descend, the power transmission from the PTO axis to the rotary cultivator 3 is restarted, the rotary 3b rotates, and the rotary 3b lands. Then the tilling work is resumed.

<Automatic termination processing>
FIG. 17 shows a subroutine of automatic termination processing for canceling the auto-down execution state based on the travel path of the traveling machine 2 in the auto-down execution state. As a condition for canceling the auto-down execution state, the control unit 52 is provided with an auto-down end condition for the auto-down off state and an auto-down release condition for the auto-down release state.

First, the control unit 52 processes the auto-down end position condition, which is the first auto-down end condition. The control unit 52 is defined by the X coordinate <-ε1 or ε1 <X coordinate and the Y coordinate <-ε1 or ε1 <Y coordinate based on the predetermined end distance ε1 in the auto-down execution state. It is determined whether or not the current position is in the end position range outside the square to be formed (step S901). In step S901, when the current position is in the end position range (YES in step S901), the control unit 52 displays the auto-down control position release display “automatically due to position limitation” shown in FIG. 18 (g) on the notification display unit 51e. Is displayed for a predetermined time t4, the automatic end process of setting the control unit 52 to the auto down / off state is executed (step S902), and the process is returned to the main routine. After the lapse of the predetermined time t4, the control unit 52 displays the engine speed / use 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. In this way, when the auto-down-off state is entered due to the auto-down end condition, the control unit 52 is set to the work mode after the auto-down timing volume 33 is once rotated to the off position in order to return to the auto-down on state again. The rotation position of the auto down timing volume 33 does not need to be changed from the off position to the on position again in a state where both the presence and the rotation position of the raising height volume 32 are located at the raising height adjusting position. Must not be.

In step S901, when the current position is not in the end position range (NO in step S901), the control unit 52 determines the -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 in 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 within the notification position range (YES in step S903), the auto-down control position notification display "exceeds the position limit" shown in FIG. 18 (f) on the notification display unit 51e as the position notification process. 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 sets −ε3 <X <ε3 based on the notification distance ε2 and the predetermined reset distance ε3 smaller than the notification distance ε2. In addition, it is determined whether or not the current position is within the end position reset range inside the square defined by −ε3 <Y <ε3 (step S905). In step S905, when the current position is in the end position reset range (YES in step S905), the control unit 52 displays the engine speed on the notification display unit 51e as the end position reset process as shown in FIG. 18A. The usage time display is displayed (step S906).

Next, the control unit 52 performs processing for the auto-down end angle condition, which is the second auto-down end condition. The control unit 52 determines whether or not the machine body angle in the auto-down execution state exceeds the predetermined end angle λ1 (step S907), and when the machine body angle exceeds the end angle λ1 (YES in step S907). , The control unit 52 displays the auto-down angle release display "turn off automatic due to angle limitation" on the notification display unit 51e for a predetermined time t4, and executes an automatic end process that puts the control unit 52 in the auto-down-off state. Then (step S902), the process is returned to the main routine. After the predetermined time has elapsed, the control unit 52 displays the engine speed / use time display on the notification display unit 51e and the temperature / fuel display on the auto-down status display unit 51a as shown in FIG. 18A.

In step S907, when the airframe angle does not exceed the end angle λ1 (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 based on a predetermined notification angle λ2. It is determined whether or not the notification angle range is defined by λ2 <airframe angle ≤ λ1 (step S908). In step S908, when the aircraft angle is within the notification angle range (YES in step S908), the auto-down angle notification display "exceeds the angle limit" is displayed on the notification display unit 51e as the angle notification process, and the operator is automatically set. A notice of cancellation of the down execution state is given (step S909).

In step S908, when the aircraft angle is not within the notification angle range (NO in step S908), the control unit 52 determines whether or not the aircraft angle is less than a predetermined reset angle λ3 smaller than the notification angle λ2 (NO). Step S910). In step S910, when the airframe angle is less than the reset angle λ3 (YES in step S910), the control unit 52 displays the engine speed on the notification display unit 51e as the end angle reset process as shown in FIG. 18A. The usage time display is displayed (step S911).

Next, the control unit 52 processes the third auto-down end condition, that is, the auto-end integrated distance condition. The control unit 52 determines whether or not the integrated mileage from the auto-down execution state to the end of the auto-down execution state exceeds the predetermined end integrated distance ξ1 (step S912). Here, the integrated mileage refers to all the moving distances of the aircraft reference point 2a from the auto-down execution state to the end of the auto-down execution state, regardless of the presence or absence of forward movement, reverse movement, and temporary stoppage. It is the added distance. In step S912, when the total mileage exceeds the end total distance ξ1 (YES in step S912), the control unit 52 displays the auto-down total distance release display "automatically turns off due to travel restriction" on the notification display unit 51e. Is displayed for a predetermined time t4, an automatic end process for setting the control unit 52 to the auto down / off state is executed (step S902), and the process is returned to the main routine. After the predetermined time t4 has elapsed, the control unit 52 displays the engine speed / use time display on the notification display unit 51e and the temperature / fuel display on the auto-down status display unit 51a as shown in FIG. 18A.

In step S912, when the integrated mileage does not exceed the end integrated distance ξ1 (NO in step S912), the control unit 52 determines that the integrated mileage is smaller than the end integrated distance ξ1 based on the predetermined notification integrated distance ξ2. , Ξ2 <Integrated mileage ≤ ξ1. It is determined whether or not the vehicle is within the notification integrated distance range defined by (step S913). In step S913, when the integrated mileage is within the notification integrated distance range (YES in step S913), the control unit 52 displays the auto-down integrated distance notification display “exceeding the travel limit” 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 the release forward / backward advance condition, which is the auto-down release condition, is satisfied (step S915). Here, the fulfillment of the release forward / backward movement condition means that the steering sensor 15 has never been turned on between the time when the control unit 52 is in the auto-down execution state and the time when the auto-down execution state is stopped. When the straight-ahead backward movement distance, which is the backward movement distance in which 2 is continuously moved only in the forward / backward direction, exceeds the predetermined release forward / backward movement distance ρ1 which is smaller than the reset distance ε3, or the control unit 52 is in the auto-down execution state. It means that the straight forward movement distance, which is the forward movement distance continuously performed only by forward and backward movement before the steering sensor 15 is turned on even once, exceeds the release front-back movement distance ρ1. .. When the release forward / backward movement condition is satisfied in step S915 (YES in step S915), the control unit 52 executes the automatic release process, and the notification display unit 51e displays the auto-down integrated distance release display "By travel restriction. "Release control" is displayed for a predetermined time t4, the auto-down release flag is set (step S916), the auto-down release state is set, and the process is returned to the main routine. After the predetermined time t4 has elapsed, the control unit 52 displays the engine speed / use time display on the notification display unit 51e and the temperature / fuel display on the auto-down status display unit 51a as shown in FIG. 18A.

When the release forward / backward movement condition is not satisfied in step S915 (NO in step S915), the control unit 52 determines that the straight-ahead backward movement distance or the straight-ahead forward movement distance is from the release front-rear advance distance ρ1 and the release front-rear advance distance ρ1. Based on a small predetermined notification forward / backward movement distance ρ2, it is determined whether or not the notification is within the notification forward / backward movement range defined by ρ2 <straight forward movement distance or straight forward movement distance ≤ ρ1 (step S917). In step S917, when either the straight backward movement distance or the straight forward movement distance is in the notification forward / backward movement range (YES in step S917), the control unit 52 automatically displays the notification display unit 51e as forward / backward notification processing. Down integrated distance notification display "Exceeds travel limit" is displayed, the operator is notified of the cancellation of the auto-down execution state (step S918), and the process is returned to the main routine.

In step S917, when both the straight-ahead backward movement distance and the straight-ahead forward movement distance are not within the notification forward / backward movement range (NO in step S917), the control unit 52 determines that the straight-ahead backward movement distance or the straight-ahead forward movement distance is the notification front-rear movement distance. It is determined whether or not it is less than the predetermined reset forward / backward advance distance ρ3, which is smaller than ρ2 and the notification forward / backward advance distance ρ2 (step S919). In step 919, when both the straight-ahead backward movement distance and the straight-ahead forward movement distance are less than the reset front-back movement distance ρ3 (YES in step S919), a notification is displayed as a release front-back movement distance reset process as shown in FIG. The engine speed / use time display is displayed on the unit 51e (step S920), and the process is returned to the main routine.

Further, in step S1, the control unit 52 processes the quick-up release condition, which is the auto-down release condition. When the quick-up lever 36 is lowered for a predetermined time of t7 or more in the auto-down execution state, the control unit 52 starts lowering the rotary cultivator 3, sets the auto-down release flag, and enters the auto-down release state. .. Further, when the quick-up lever 36 is raised for less than a predetermined time t2 in the auto-down execution state, the control unit 52 puts the stop symbol 51f shown in FIG. 18C on the warning display unit 51d for a predetermined time t4. It is displayed until it is displayed, the auto-down release flag is set, and the auto-down release state is set.

<Effect of this embodiment>
From the above, the control unit 52 sets the descending start line on the coordinate system with the turning start position of the traveling aircraft 2 as the origin O, and descends the rotary cultivator 3 when the current position of the traveling aircraft 2 reaches the descending start line. Therefore, when the tractor 1 reciprocates to cultivate the field H, the operator can select an arbitrary route to turn the traveling machine 2 and the timing to start the descent of the rotary cultivator 3. It is not necessary to judge by oneself, and the headland width M from the ridge E can be easily aligned. In addition, it is possible to prevent erroneous operations such as the operator erroneously starting the descent of the rotary tiller 3 and the formation of an uncultivated portion of the field H and the double tillage work, so that the efficient tillage work can be performed.

Further, since the traveling aircraft 2 includes a liquid crystal display device 51 capable of displaying the direction of the traveling aircraft 2 at the current position with respect to the position of the descending start line, the operator operates the traveling aircraft 2 to move toward the descending start line. You can know the direction you should go. Further, in the liquid crystal display device 51, the front-rear direction display unit 51b capable of displaying the positional relationship of whether the descending start line is located in front of or behind the traveling machine 2 at the current position, and the descending start line are at the current position. Since it has a left-right direction display unit 51c capable of displaying the positional relationship of whether the traveling aircraft 2 is located on the right side or the left side of the traveling aircraft 2, the operator operates the traveling aircraft 2 in order to move toward the descending start line. It is possible to know the front-back direction and the left-right direction to be turned.

Further, since the front-rear direction display unit 51b is provided so as to be able to display that the distance from the traveling aircraft 2 to the descending start line is equal to or less than a predetermined distance, the operator is close to reaching the descending start line of the traveling aircraft 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 by the orientation of the traveling aircraft 2 at the start of turning and the orientation of the traveling aircraft 2 at the current position, the operator can display the display unit 51c. It is possible to know the approximate angle at which the traveling aircraft 2 should be turned in order to approach the descent start line. Further, since the left-right direction display unit 51c has a plurality of display units 51i provided so as to be able to switch between a lit state and a non-lighting state, the operator can recognize the change of the left-right direction display unit 51c at a glance. Can be done.

Further, when the auto down execution state is entered, the control unit 52 starts notifying the operator by a 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. Since the interval between the short sounds of the notification buzzer 53 is shortened when the distance becomes β or less, the operator can know in advance that the auto-down execution state is in progress and that the descending start line is near. The operator can predict the difference between the tillage restart position due to the automatic descent of the rotary tiller 3 with auto-down control and the tillage restart position desired by the operator.

Further, in the auto-down release state, the shuttle lever 35 is switched from the neutral position to the reverse position when the backup mode is on and the rotary cultivator 3 is not located at the upper limit height, and the turning up mode is on. At least one of the switching from the off state to the on state of the steering sensor 15 and the raising operation of the quick-up lever 36 for a predetermined time t1 or more when the rotary cultivator 3 is not located at the upper limit height. Is detected, the auto-down execution state is entered, and the descending start line is set on the coordinate system with the turning start position as the origin O, so that it is possible to respond to various turning operation procedures that differ depending on the operator's preference, etc. It is possible to improve the degree of freedom of operations to be performed, reduce unnecessary operation procedures, and reduce the operation burden on the operator.

Further, when the machine body angle does not satisfy the turning angle condition, the control unit 52 does not lower the rotary cultivator 3 even if the traveling machine body 2 reaches the descent start line, so that the rotary cultivator is not intended by the operator. It is possible to prevent the aircraft 3 from descending. Further, since the descending start line is defined only by the coordinates in the front-rear direction of the aircraft reference point 2a at the start of turning, the operator can freely select the position of the traveling aircraft 2 in the left-right direction at the time of resuming work. For example, since the tilling work can be performed every other row, the degree of freedom of operation can be improved and the processing load of the control unit 52 can be reduced.

Further, the control unit 52 previously stores the turning inner circumference and the turning outer circumference 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 circumference corresponding to the selected mode. And since the current position is calculated based on the turning circumference, 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 error from the ridge is reduced. The headland width M can be aligned to a predetermined width with high accuracy.

Further, since the control unit 52 does not enter the auto-down execution state when the 2WD mode unsuitable for the tilling work in the field H or the high-speed stage with a predetermined reduction ratio or less is selected, the operator It is possible to prevent the rotary tiller 3 from unintentionally descending. Further, since the control unit 52 sets the descent start line based on the upper limit height of the rotary cultivator 3 and the vehicle speed in the auto-down execution state, the time required from the start of the rotary cultivator 3 to the ground contact. It is possible to prevent variations in the ground contact position due to the difference between the above and to align the headland width M from the ridge to a predetermined width with high accuracy.

Further, since the control unit 52 sets the descent start line based on the upper limit height of the rotary cultivator 3 adjusted by the operation of the raising height volume 32, the rotary cultivator 3 touches down after starting the descent. It is possible to prevent variations in the ground contact position due to the difference in the time required for the process, and to align the headland width M from the ridge to a predetermined width with high accuracy. Further, the lowering speed of the rotary cultivator 3 can be adjusted by the operation of the working machine lowering speed adjusting knob 29, and the control unit 52 sets the lowering start line based on the lowering speed of the rotary cultivator 3. Therefore, the convenience is improved, and the variation in the contact position due to the difference in the time required from the start of descent of the rotary tiller 3 to the contact with the ground is prevented, and the headland width M from the ridge is increased to a predetermined width. It can be aligned with precision. Further, since the Y coordinate of the descending start line can be adjusted by the auto-down timing volume 33, an error may occur in the descending start line due to slippage of traveling devices such as the front wheels 5 and the rear wheels 6, or a field that is not rectangular. For example, it is possible to easily cope with the case of cultivating in a field such as a trapezoid, improving convenience, and it is possible to align the headland width M from the ridge to a predetermined width with high accuracy.

Further, 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 more in the auto-down execution state, the operator can slip the front wheels 5 or the rear wheels 6. When it is predicted that the timing at which the lowering of the rotary cultivator 3 by the auto-down control is started is earlier than the timing at which the operator desires the lowering due to the operator making a mistake in the steering operation, the rotary cultivator 3 The start of the descent can be temporarily paused. In addition, the operator can know in advance the timing at which the rotary cultivator 3 starts descending by the advance notice that the interval between short sounds from t5 to t6 is changed by the notification buzzer 53, and the rotary cultivator 3 is based on the advance notice. When it is determined that the timing at which 3 starts descending is too early, the rotary cultivator 3 can be temporarily suspended, and the rotary cultivator 3 can be started descending while visually confirming the restart position of the work. .. Further, in the auto-down execution state, the auto-down execution state is released by a short raising operation of the quick-up lever 36 for less than a predetermined time t2, so that the lowering of the rotary cultivator 3 can be easily interrupted and further quick-up. Since the auto-down execution state can be re-established by raising the lever 36, the operator can easily redo the turning, and the convenience can be improved.

Further, the control unit 52 calculates the current position and the body angle of the traveling machine 2 in the auto-down execution state, and when the traveling machine 2 is separated from the turning start position by more than a predetermined distance ε1, the turning angle is determined from 180 °. When the space is opened more than an angle or when the total mileage of the traveling machine 2 exceeds the predetermined distance ξ1, the auto down-off state is set. Therefore, when traveling on the headland after finishing the tilling work performed while reciprocating the field H. It is possible to prevent the rotary tiller 3 from being lowered unintentionally by the operator after going out of the field.

Further, when the straight-ahead backward movement distance exceeds a predetermined forward / backward movement release distance ρ, or when the straight-ahead forward movement distance exceeds the front-back movement 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 cultivator 3 from being lowered unintentionally by the operator, and it is possible to re-enter the auto-down execution state with a small number of operations.

Further, the position of the traveling machine 2 in the auto-down execution state is calculated by the steering sensor 15 and the vehicle speed sensor 11 which can use an inexpensive contact switch, an optical sensor, etc. without using an expensive gyro sensor, GPS, or the like. Therefore, the cost can be suppressed. In the auto-down control, the current position and the body angle of the traveling machine 2 are calculated based on the value of the turning radius r which differs depending on the maximum output of the engine and the type and dimensions of the traveling devices such as the front wheels 5 and the rear wheels 6, so that the turning radius The control unit 52 can be shared between traveling aircraft 2 having different radii. Further, the turning radius r of the traveling machine 2 is calculated based on whether or not the front wheel double speed control and the auto brake control are executed, and the current position and the body angle of the traveling machine 2 are calculated from this turning radius r. The calculation accuracy of the current position of the machine body 2 is improved, and the headland width M from the ridge can be aligned to a predetermined width with high accuracy.

Although the vehicle speed is determined to detect the rotation of one of the rear wheels 6 and the rotation of the rear wheel drive shaft, the rotation of the other part 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 auxiliary transmission mechanism are multi-stage transmission mechanisms, but if the total reduction ratio, which is the ratio of the engine speed to the rotation speed of the rear wheels 6, can be detected, The main transmission mechanism and the auxiliary transmission mechanism may be a continuously variable transmission mechanism, or may be configured to include only one of them. As the turning start operation, the rotary tiller 3 may be lifted by operating the position lever 31.

Although the visual notification to the operator is based on a change in the design or notification text of the liquid crystal display device 51, an organic EL display other than the liquid crystal display or a dot matrix display device of the LED lamp may be used instead, or light emission. Notification may be given by a change in the color or position of the display device. The various operating tools for inputting to the control unit 52 may be a touch panel provided on the liquid crystal display device 51 instead, or an input device provided outside the traveling machine body 2 capable of wireless communication. There may be. The structure may include a remote control device for operating the tractor 1 from a distance without the operator getting on the vehicle, and the steering device may be driven by a motor, flood control, or the like to steer the front wheels 5. 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. The control unit 52 may be configured to be able to calculate based on the turning radius r calculated according to the operating angle. The operation of the steering wheel 13 may be directly detected by the rotation of the steering wheel 13, or may be detected by 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.

Although the tractor 1 provided with the rotary cultivator 3 has been described in the above embodiment, the working machine is not limited to this, and the working machine may be a puddling work machine, a plow, or the like, or a work that can be raised and lowered to the traveling machine 2 such as a rice transplanter. It is also applicable to other work vehicles equipped with a machine.

1 Work vehicle (tractor)
2 Traveling machine 3 Working machine (rotary cultivator)
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-back direction display 51c Left-right direction display 51i Display 52 Control means (control unit)
53 Notification means (notification buzzer)

Claims (4)

In a work vehicle including a traveling machine supported by a traveling device, a steering unit for steering the traveling device, and an elevating device for raising and lowering the working device.
When the work machine descent start line is set on the coordinate system with the position at the start of turning of the traveling machine as the origin and the working machine descending start line is reached with the traveling machine completed turning, the elevating device causes the work machine to descend . A control means capable of executing turning control for starting the descent of the work machine, and
A front-rear direction display unit capable of displaying whether the working machine descent start line is located in front of or behind the traveling machine at the current position, and an operation for the traveling machine to reach the working machine descent start line. e Bei right and left direction display unit showing the lateral direction of the steering unit should Kosu, a display unit having a, a,
The left-right direction display unit includes a left-side display unit indicating that the steering unit should be steered to the left side and a right-side display unit indicating that the steering unit should be steered to the right side. Have and
The front-rear direction display unit is located between the left side display unit and the right side display unit in the left-right direction.
A work vehicle characterized by that. 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 working machine descending start line is not more than a predetermined distance.
The work vehicle according to claim 1 . The left side display unit and the right side display unit each have a plurality of scales that stepwise indicate the relationship between the traveling direction of the traveling aircraft in a state where turning is completed and the traveling direction of the traveling aircraft at the current position .
The work vehicle according to claim 1 or 2 . A notification means for notifying by sound that the work equipment descent start line is set is provided.
The notification means starts notifying that the work equipment descending start line is set by a short sound repeated from the start of turning, and in a state where the work equipment descending start line is set. A short sound about the relationship between the traveling direction of the traveling machine in the state where the change in the distance from the current position of the traveling machine to the lowering start line of the working machine and the turning is completed and the traveling direction of the traveling machine at the current position. It is provided so that it can be notified by the change of the interval of
The work vehicle according to any one of claims 1 to 3 .

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