KR20230047067A - Working vehicle - Google Patents

Abstract

The present invention provides a working vehicle which, when a vehicle body approaches a target position, allows an operator to realize before unnecessary operations or driving are performed. The working vehicle, which includes a steering member (35) steering a vehicle body, a position information acquisition device (200) acquiring the position coordinates of the vehicle body, and an automatic straight driving device (205) operating the steering member (35) to drive the body straight, comprises: a single operating member (207) which acquires a reference position that serves as a basis of straight driving and performs the on and off operation of the automatic straight driving device (205), wherein the reference position includes a first reference point (A) and a second reference point (B), and the straight driving by the automatic straight driving device (205) is performed along a baseline (R) connecting the first reference point (A) and the second reference point (B).

Description

WORKING VEHICLE}

The present invention relates to a work vehicle that travels in a field and performs ground work with a work device that travels on a vehicle body.

In a conventional work vehicle, the coordinates of the work start position and work end position are acquired, and when the machine reaches the coordinates matching the work start position and work end position of each work group, a notification device is operated to inform the operator of the work start position and work end position. There is a device provided with notification of arrival at the work end position (Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-7196

However, in the work vehicle of Patent Literature 1, the notification device operates when reaching the work end position, so unless the operator notices the operation of the notification device, the machine travels beyond the work end position while working on the ground.

At the work end position, the work of the working device is stopped or a turning run is started to move the machine to the next work group. will be thrown away

Accordingly, when the paving end is driven for work, work is performed again at an already worked part, causing a problem of excessive consumption of working materials.

In addition, in order to match the work end position before turning with the work start position after turning, it is necessary to reverse the machine to the work end position and once stop before turning, so extra travel is required and the work time becomes longer. there is a problem.

An object of the present invention is to solve the above problems and to provide a work vehicle capable of allowing an operator to notice before unnecessary work or travel is performed when a machine approaches a target position.

The invention described in claim 1 includes a steering member 35 for steering the aircraft, a positional information acquisition device 200 for acquiring positional coordinates of the aircraft, and an automatic straight-going device for driving the aircraft straight by operating the steering member 35. In the work vehicle provided with 205, acquisition of a reference position serving as a standard for straight-line driving and on/off of automatic straight-going device 205 are performed by one operation member 207, and the reference position is , Including the first reference point (A) and the second reference point (B), according to the reference line (R) connecting the first reference point (A) and the second reference point (B), to the automatic straight ahead device 205 It was set as a work vehicle characterized in that straight running by is performed.

The invention of claim 2 according to claim 1, wherein when the operating member 207 is operated in the first direction W1, the reference position is obtained, and when the operating member 207 is operated in the second direction W2, the automatic straight ahead device ( 205) was turned on and off as a working vehicle.

The invention of claim 3 is the work vehicle according to claim 1 or 2, characterized in that the deletion of the acquired reference position is performed by operating the operation member 207 .

According to the inventions of claims 1 and 2, since the machine can be automatically moved in a straight line based on the reference position obtained by operating the operating member 207, the running trajectory is aligned in a straight line and the work precision is improved.

In addition, since there is no need to operate the steering member 35 to maintain straight driving, the labor force of the operator is reduced.

In addition, since acquisition of the reference position and on/off of the automatic straight-ahead device 205 can be performed with one operating member 207, the number of parts can be reduced.

According to the invention of claim 3, in addition to the effect of the invention of claim 1 or claim 2, the operation of deleting the reference position can be simplified, so that the change of the reference position of automatic straight-line driving is facilitated and work precision is improved.

1 is a side view of a seedling transplanter.
2 is a plan view of the seedling transplanter.
3 is a rear view of a main part of a steering unit including a steering member.
Fig. 4 is a block diagram showing members related to various types of control.
Fig. 5 is a flow chart showing control for correcting the acquired positional coordinates according to the inclination of the body and the like.
6 is a flowchart showing automatic straight-ahead control by an automatic straight-ahead device.
Fig. 7 is a flow chart showing acquisition of first and second reference positions by operation of an operating member, and on/off of automatic straight-going control.
8 is a flowchart showing an operation of erasing the first reference position and the second reference position.
Fig. 9 is a flowchart showing control for canceling the first reference position by steering member operation after obtaining the first reference position.
Fig. 10 is a schematic diagram of an operation of indicating a target position as well as showing a first reference position, a second reference position, and a reference line.
Fig. 11 is a flowchart showing the operation of the notification device and automatic deceleration control when the stop operation of the automatic straight ahead device is not performed after the operation of the notification device.

EMBODIMENT OF THE INVENTION Embodiment of this invention is described based on drawing.

As shown in FIGS. 1 and 2 , the rice transplanter, which is an example of the working vehicle in this case, is a seedling planting unit for planting seedlings via a lifting link device 3 on the rear side of the traveling vehicle body 2 and a seeding device for supplying seeds. The working device 4 of the back is provided so that it can move up and down.

A transmission case 13 and a continuously variable transmission device 14 that outputs driving force supplied from the engine 30 to the transmission case 13 are installed in the main frame 15 of the traveling vehicle body 2 .

As shown in FIGS. 1 and 2 , on the front side of the running vehicle body 2, a steering member 35 for steering the body, a shift control lever 36 for operating the continuously variable transmission device 14 and the work device 4, and traveling A bonnet 39 having a sub-shift control lever 37 for manipulating a sub-shift switching device (not shown) for switching driving power of the vehicle body 2 and a control panel 38 for manipulating each part of the body on the top thereof. install A front cover 40 that can be opened and closed is installed on the front side of the bonnet 39, and inside the front cover 40, the left and right front wheels 10 and the left and right front wheel transmission cases 10a are connected to the steering of the steering member 35. An interlocking mechanism (not shown) for rotating the lower side is incorporated.

Further, as shown in FIGS. 1 and 2 , a center float 62C and left and right side floats 62L and 62R are provided below the working device 4 to slide while being grounded on the pavement surface, and the center float A stop device 63, which is a ground work device for stopping the pavement surface, is installed on the front side of the body from 62C and the left and right side floats 62L and 62R. The driving force to the stop device 63 is transmitted by a stop transmission shaft 65 installed in the left and right rear wheel transmission case 11a. A stop clutch for turning on/off transmission to the stop device 63 is installed in the rear wheel transmission case 11a.

In addition, the stop device 63 is composed of both left and right ends of the center rotor 63a for stopping the front of the center float 62C and the left and right side rotors 63b for stopping the front of the left and right side floats 62L and 62R. It is configured by connecting the inner ends of the aircraft to the stationary transmission case 67, respectively.

When using the work device 4 to plant seedlings, sow seeds, or perform operations such as fertilizing or weeding after seedling growth, it is driven straight from one side of the field to the other side. However, there are cases where it moves in a direction deviated from the straight direction due to the unevenness of the pavement or the viscosity of the topsoil. In addition, there is a case where the travel direction is shifted from the straight travel direction due to operator's manipulation.

As a result, the work trajectory becomes oblique, and the place where planting and sowing of seedlings is possible becomes an empty space, so planting and seeding work must be performed from the rear, which requires extra labor, and between planting and sowing. There is a problem that it is narrower than the jaws of the working device 4, so that pests and diseases easily occur. Or, when performing post-planting or seeding operations such as weeding or fertilizing, there is a problem of crushing the seedlings, resulting in a decrease in yield, or reducing work efficiency by carefully maneuvering to avoid seedlings.

In order to solve the above problem, a so-called automatic straight-going system may be installed, which automatically steers the running vehicle body 2 to maintain a straight-running posture.

As shown in FIGS. 1 and 2 , a door-shaped antenna frame 201 when viewed from the front is installed on the traveling vehicle body 2 to which a positional information acquisition device 200 for receiving a GPS signal is mounted. In the antenna frame 201, the left and right bases are attached to the left and right antenna stays 202 installed on the front side of the main frame 15, and the bonnet 39 is attached to the rear of the space of the door-shaped antenna frame 201. or the steering seat 41 is arranged.

In addition, the vertical height of the antenna frame 201 is the highest among aircraft. The upper end of the antenna frame 201 is located about 2.5 to 3.5 m from the ground to prevent contact with the operator's head and to improve reception accuracy.

This makes it easier for the operator to move on the floor step 33, improving work efficiency, and also improving reception accuracy by spacing the positional information acquisition device 200 upward.

In addition, the mounting position of the positional information acquisition device 200 is near the front and back of the bonnet 39 and the steering seat 41, and is near the center of the traveling vehicle body 2 in the front and rear direction.

Since the location information acquisition device 200 is arranged near the center of the body in the front-back and left-right directions, the acquisition accuracy of the coordinates of the traveling vehicle body 2 is improved, so that the straight-running position setting by the automatic straight-going system becomes appropriate, and the work precision is improved. do.

In addition, since the control seat 41 is located at the rear of the space of the antenna frame 201, it is possible to prevent the operator's field of view from being obstructed, so visibility is improved, positioning before traveling straight is accurate, and the packaging in front of the aircraft is improved. Since anomalies and obstacles can be detected quickly, shifting by manual operation can be performed to suppress shifting of the work position while ensuring safety.

As shown in FIG. 4 , an IMU (inertial measurement unit) 203 is installed in addition to the positional information acquisition device 200 . The IMU 203 determines the height from the surface of the ground to the positional information acquisition device 200 when the traveling vehicle body 2 is inclined and the height from the surface of the ground to the positional information acquisition device 200 when it is not inclined. Based on the difference, the positional coordinates acquired by the positional information acquisition device 200 are corrected by the control device 100.

In addition, the height from the surface of the earth to the positional information acquisition device 200 is calculated by measuring the behavior of the vehicle body 2, such as inclination, with a 3-axis acceleration sensor and an angular velocity sensor built into the IMU 203.

In addition to this, an orientation sensor 204 is provided in order for the controller 100 to reliably determine whether or not the running direction of the aircraft by the automatic straight ahead system is correct.

Correction of the positional coordinates at this time is as shown in S1 to S5 in FIG. 5 .

As a result, since the course of the machine can be determined according to the direction, the accuracy of straight running is further improved.

Positional information acquired by the positional information acquisition device 200 is corrected by the control device 100 based on information detected by the IMU 203 and the orientation sensor 204 . Then, the control device 100 compares the current location information with the previously obtained location information, and if the difference in the location information exceeds the allowable range, the left and right front wheels 10 are moved in the left and right directions in order to return the aircraft to the straight driving position. steering with

In order to automate the steering of the left and right front wheels 10, an automatic straight-ahead device 205 for rotating the steering member 35 with a steering actuator 206 is installed. As shown in S6 to S9 of FIG. 6, the automatic straight-going device 205 determines the difference between the X coordinate of the current location information calculated by the control device 100 and the X coordinate of the previously acquired standard location information. Based on this, the operation amount of the steering actuator 206 is controlled, so that the steering member 35 is turned left and right to direct the aircraft to the straight travel position, and when it comes to the straight travel position, the steering actuator 206 is stopped and the steering member is stopped. Stop the automatic steering of (35).

Since the steering member 35 is automatically steered according to the difference in the X coordinate of the positional information calculated as described above to automatically move the body to the straight traveling position, it is difficult for the working position of the working device 4 to shift in the left and right directions. It is prevented and the occurrence of a place where work is not performed is prevented. Thereby, there is no need to perform the work manually from the back, and the labor force of the operator is reduced.

In addition, since it is possible to prevent overlapping of the working positions of the previous working group and the current working group, the unnecessary consumption of work materials such as seedlings, seeds, and fertilizers is prevented, thereby reducing the work cost and promoting the reduction of work materials. The occurrence of poor growth due to overfeeding is prevented.

The work vehicle travels to the pavement end of the work group, turns about 180°, and moves to the next work group. If the automatic straight-ahead system is operating while turning, it is determined that the aircraft is displaced from the position where it is supposed to travel straight, and the steering actuator 206 is actuated to disturb the turning trajectory. Therefore, the automatic straight ahead system needs to be turned off when turning the aircraft. Turning the steering member 35 can also turn off the automatic straight ahead system. At this time, the automatic straight-ahead system turns off, so the automatic steering system must be turned on again in the middle of a straight-ahead, which increases the labor of the operator, and the aircraft travels while the working position is misaligned because the automatic straight-ahead system is off. There is a problem of deterioration of precision.

In addition, it is considered to turn on the automatic straight-going system in the operation of returning the steering member 35 from turning to straight-going, but when returning from turning to straight-going, in order to adjust the machine to the straight-going position in the next work group, delicate steering It is necessary to perform steering operation of the member 35. If the automatic steering system is turned on during this operation, if the controller 100 determines that the aircraft is displaced from the straight-travel position, the steering actuator 206 will operate so that the aircraft's position cannot be adjusted to the original straight-travel position. there is a problem

An automatic straight-going system capable of preventing this problem from occurring, allowing the aircraft to travel straight in an appropriate direction, and operating in an appropriate section will be described with reference to FIGS. 4 and 6 to 9 .

In addition, positional coordinates in the forward and backward direction of the traveling vehicle body 2 are taken as Y coordinates, and position coordinates in a direction orthogonal to the forward and backward directions of the traveling vehicle body 2, that is, in the left and right directions are taken as X coordinates.

First, an operating member 207 for turning on/off the automatic straight-going system is installed in the traveling vehicle body 2, acquiring the coordinates of one side of the pavement, which is the starting point of automatic straight-going, and the other side of the pavement, which is the end point of automatic straight-going. do. As the operating member 207, at least one member capable of being operated in at least two directions, such as up-down direction, left-right direction, pressing state and return state, is attached, or two or more operating members are attached.

As the operating member 207 in the present application, as shown in Fig. 3, a finger-up lever operable in the vertical direction is provided, but a toggle switch, a push switch, a joystick, or the like may be used.

In this way, while reducing the number of parts is achieved, the acquisition operation of the reference position (first reference position (A), second reference position (B)) and the on/off operation of the automatic straight ahead device 205 are performed on the same side Since it is only necessary to operate the operation member 207 with one's hand, the operability is improved.

As shown in FIG. 3 , when the operation member 207 is operated in the first direction W1, in the present application, upwards of the aircraft, the positional information acquisition device 200 is obtained from the operated position, and the IMU 203 and the orientation sensor 204 are acquired. The positional coordinates calculated by the control device 100 using the detection result of ) are recorded. Further, the operation of the operation member 207 in the first direction W1 corresponds to the operation of the reference position obtaining member.

When the operating member 207 is operated, if no other position coordinates are recorded, the calculated position coordinates are recorded as the first reference point (A), and when the first reference point (A) is recorded, the calculated position coordinates are recorded. 2 Record as the reference point (B). When the operating member 207 is operated while the first reference point A and the second reference point B are recorded, the positional coordinates are not recorded.

In addition, since it is necessary to re-acquire the first reference point A and the second reference point B when, for example, automatic straight-going is not performed with high accuracy during work in the pavement, as shown in FIG. ) is operated in the first direction (W1) over a predetermined time (eg, 2 to 3 seconds), the recorded first reference point (A) and the second reference point (B) may be set to be erased. Alternatively, a record erasing button (not shown) may be provided to delete the first reference point A and the second reference point B when operated.

The distance between the first reference point (A) and the second reference point (B), which are the reference positions for straight driving of the automatic straight ahead system, is smaller as the distance is shorter, but if the distance between the two points is short, the automatic straight ahead is not used. driving is possible. Also, when the distance between the two points becomes short, a situation is considered in which the operator unintentionally touches the operating member 207 and acquires the second reference point B.

In order to prevent this problem from occurring, when the operation member 207 is operated to obtain the second reference point B, the distance from the position where the first reference point A is acquired is less than a predetermined distance, for example, 8 to 12 m. When it is less than, the control device 100 deletes the second reference point B and does not record it. After that, if the distance from the position where the operation member 207 is operated again to acquire the first reference point A is equal to or greater than a predetermined distance, the control device 100 records the second reference point.

Further, as shown in FIG. 9 , in the state where the first reference point A is obtained, without acquiring the second reference point B, the steering member 35 is operated by a predetermined amount or more within a predetermined time to move the traveling vehicle body 2. When turned, the control device 100 deletes the recorded first reference point A. Then, when the operating member 207 is operated in the first direction W1, the control device 100 records the positional coordinates of the place acquired by the positional information acquisition device 200 as a first reference point A, A configuration may be employed to prevent the line connecting the Y-coordinate of the first reference point A and the Y-coordinate of the second reference point B from becoming a straight line.

Accordingly, there is a predetermined position where one end and the other end of the pavement are located, for example, a position where the traveling car body 2 starts turning after the straight running ends, and a position where the working device 4 is lowered and starting the straight running after turning ends. The first reference point (A) and the second reference point (B) can be set, and the automatic straight ahead system is operated at the position where the work device 4 is lowered and travels straight so that the working position does not shift in the left and right directions with respect to the traveling direction. High-density work is possible.

In addition, since it is possible to prevent the second reference point (B) from being different from the position to be actually set due to operator's erroneous operation, it is necessary to acquire the first reference point (A) and the second reference point (B) again in the next work team. There is no, and the number of working teams using automatic straight ahead can be increased to further improve the precision of work in the pavement.

In addition, in a work crew that performs work first after entering the packaging, the operation member 207 is operated in the first direction W1 at a predetermined position to obtain the first reference point A and the second reference point B. Since the work is essential, the operator operates the steering member 35 to drive the aircraft straight without using automatic straight-going.

As described above, if the first reference point (A) and the second reference point (B) are obtained by operating the operating member 207, each Y coordinate of the first reference point (A) and the second reference point (B) is connected. The reference line R becomes a target line for automatic straight ahead, and it is determined whether or not the X coordinate of the positional coordinates of the aircraft during travel coincides with the X coordinate of the target line for automatic straight ahead, and if it does not match, the automatic straight ahead device ( By automatically steering the steering member 35 in the matching direction by 205, automatic straight running can be realized.

The automatic straight-line travel is initiated by operating the operating member 207 toward the second direction W2, in this case, downwardly, with the first reference point A and the second reference point B recorded. When the operating member 207 is operated in the second direction W2, the control device 100 compares the Y coordinate of the positional coordinates acquired by the positional information acquisition device 200 with the Y coordinate of the reference line R to obtain a steering actuator. 206 is actuated to rotate the steering member 35 in the left-right direction and start control to move the traveling vehicle body 2 to the position to travel straight. Further, the operation of the operation member 207 in the second direction W2 corresponds to the operation of the on/off member.

This automatic steering control ends when the steering member 35 is operated to an angle that turns the traveling vehicle body 2 within a predetermined time, or when the operating member 207 is operated in the second direction W2. The steering angle of the steering member 35 is detected by the potentiometer 35a.

Further, when the traveling vehicle body 2 arrives at a place matching the Y coordinate of the first reference point A or the second reference point B, the automatic straight-going control may end.

As described above, the automatic straight-going control is terminated by operating the steering member 35 to turn or reaching the vicinity of the start point of the turning run at the pavement end. Since the position at which the driving vehicle body 2 turns and travels is a position close to the pavement edge, if the operator performs work other than steering by entrusting the automatic straight-ahead control, if the turning operation is delayed, seedlings are planted at an unexpected position, and the traveling vehicle body (2) moves to the pavement end, and it is necessary to move backward to the turning position, resulting in a decrease in work efficiency.

10 is a schematic diagram showing the first reference position (A), the second reference position (B), the reference line (R), the target position, and the current position of the aircraft.

In order to prevent this problem, as shown in FIGS. 4 and 11 , an operation detecting member 209 for detecting on/off of the stopping device 63 by turning on (actuating) and turning off (stopping) the stopping clutch is provided. , When the operation detecting member 209 detects that the stop device 63 is turned on (operated), the control device 100 sets the position coordinates (X coordinate and Y coordinate) of the traveling vehicle body 2 to the target position coordinate (end reference position) is acquired. In addition, at least two target position coordinates can be held simultaneously in the control device 100 or a memory area associated with the control device 100.

In addition, the acquisition of the target position coordinates (end reference position) by the work detecting member 209 raises or lowers the work device 4 instead of turning on/off the stop device 63, or turns on the electric power to the work device 4. Or it is good also as a structure performed on the condition of off, turn start steering of the steering member 35, turn end steering, etc.

Then, in a work crew following the work crew having acquired the positional coordinates, when the automatic straight-going device 205 is actuated to cause the traveling vehicle body 2 to automatically travel straight ahead, the control device 100 allows the position information acquisition device 200 to acquire The distance from the Y-coordinate of the current position coordinate to the Y-coordinate of the target position coordinate acquired by the immediately preceding work team (immediately nearby work group) is gradually calculated. At this time, the control device 100 may be configured to correct the X coordinate of the target position coordinate to the X coordinate of the current position coordinate.

Then, when the traveling vehicle body 2 arrives at the notification position at which the distance from the current position coordinates to the target position coordinates is a predetermined distance, for example, 8 to 12 m, the traveling vehicle body 2 is approaching the pavement end, and the operation is performed. In order to notify the operator that it is necessary to terminate the automatic straight-ahead control by operating the member 207 in the second direction (W2), a buzzer, lamp, or notification device 208 displaying numerical values or characters on the screen operates. make up the composition.

In addition, a configuration in which a display panel (not shown) is installed on the traveling vehicle body 2 or a configuration in which information is transmitted and displayed on an information terminal carried by an operator can be considered for displaying numerical values or characters on the notification device 208. .

In addition, since the distance between the driving vehicle body 2 and the target position cannot be calculated in the case of a work crew that does not acquire target position coordinates, the operator visually checks the pavement end and controls the control member 207 at a position where automatic straight-ahead control is determined to be unnecessary. ) needs to be manipulated.

Regarding the distance from the current position coordinate to the target position coordinate, a rear wheel rotation sensor 210 for detecting the rotation of the left and right drive shafts 42 to the left and right rear wheels 11 is provided, and the stop device 63 is turned on. Based on the number of rotations detected by the rear wheel rotation sensor 210 from one position, the controller 100 calculates the movement distance, and the distance from the movement distance to the Y coordinate position of the position where the stop device 63 is turned on. It is good also as a structure which calculates and activates the notification device 208 if it is within a predetermined distance. Also, the rear wheel rotation sensor 210 is an example of a distance detecting member.

However, even if the notification device 208 operates, the traveling vehicle body 2 cannot be turned at an appropriate position unless the operator notices and terminates the automatic straight-going control. In order to cope with this, the running vehicle body 2 moves without the operation member 207 being operated in the second direction W2 over a predetermined distance (for example, 2 to 5 m) after the notification device 208 operates. When traveling forward, the control device 100 rotates the trunnion shaft 14a of the continuously variable transmission 14 to decelerate the traveling vehicle body 2.

Alternatively, the running vehicle body 2 moves without the operating member 207 being operated in the second direction W2 for a predetermined period of time (for example, 2 to 5 seconds) after the notification device 208 operates rather than the distance. When traveling forward, the control device 100 lowers the output of the continuously variable transmission device 14 to decelerate the traveling vehicle body 2.

The deceleration of the traveling vehicle body 2 operates the control motor 211 that rotates the trunnion shaft 14a of the continuously variable transmission 14 through a trunnion arm (not shown) to decelerate the trunnion shaft 14a. It is done by turning to the side.

Accordingly, when approaching the pavement end, the travel speed of the traveling vehicle body 2 is reduced, so that the operator can be recognized that the turning position of the pavement end is approaching, and the turning run is performed in an appropriate trajectory. Therefore, it is prevented that the work device 4 performs ground work in duplicate on the four sides of the outer periphery of the field, so-called dog seat, and consumes work materials (seedlings, fertilizers, chemicals, etc.) in excess.

In addition, since the stopping device 63 is turned on after turning and the position where the stopping work is started can be aligned with the position where the stopping work is finished before turning, occurrence and operation of a place where the stopping work by the stopping device 63 is not performed Occurrence of a place where ground work is not performed by the apparatus 4 is prevented. In this way, the occurrence of the problem that the planting depth of the seedlings is disturbed and the penetration state of the fertilizer is different, and the running is disturbed, is prevented from occurring in the place where the ground work is not performed, and the operator manually works in the place where the ground work is not performed. Since there is no need to perform work with the machine, the labor force of the operator is reduced.

The automatic deceleration is such that the travel speed gradually decreases over time, and when the control configuration is gradually decelerated, the ground work accuracy by the work device 4 and the stop accuracy of the stop device 63 are reduced, Workers are prevented from shaking.

Alternatively, if a control configuration is adopted in which rapid deceleration is performed once or multiple times at predetermined time intervals after the start of automatic deceleration, it is easy for the operator to notice the approach of the pavement end due to shaking of the traveling vehicle body 2.

In addition, if automatic straight-ahead control is canceled by operating the operation member 207 within a predetermined time (second predetermined time) during which automatic deceleration control is being performed, the controller 100 may maintain the running speed at that time. As a result, since work travel does not stop, it is possible to promptly shift to turning travel at the pavement edge, preventing work efficiency from deteriorating.

Alternatively, the controller 100 operates the control motor 211 of the continuously variable transmission 14 to move the trunnion shaft 14a to shift to the preset travel speed or the travel speed at the time when automatic deceleration starts. It is good also as a structure which rotates to the speed-up side.

By automatically increasing the traveling speed, the operator does not need to operate the shift control lever 36 to increase the traveling speed, so the operability is improved.

In addition to the operation of the notification device 208, it is expected that the traveling vehicle body 2 recognizes the turning position near the pavement end, specifically, the pavement end, by the automatic deceleration control of the traveling car body 2. It is assumed that the automatic reduction in travel speed is not noticed because the worker is immersed in the work of the driver or the operator faints.

Accordingly, the automatic deceleration control of the traveling vehicle body 2 is performed until the continuously variable transmission device 14 reaches a neutral state in which neither the traveling speed increases or decreases during forward or reverse travel. At this time, the engine 30 is not stopped. Accordingly, since the traveling vehicle body 2 can be stopped in place, it is prevented from advancing until the aircraft contacts the pavement edge, so-called headland, and damage to the aircraft or the distance to reverse the aircraft to return to work is suppressed.

When the traveling of the traveling vehicle body 2 is automatically stopped by approaching the pavement edge, it is controlled by returning the shift control lever 36 for controlling the increase and decrease of the traveling speed of the traveling vehicle body 2 and the forward/reverse movement to the neutral position. The device 100 is in a state of accepting an increase/decrease operation of the travel speed by the continuously variable transmission device 14 . In addition, when the shift control lever 36 is operated to the forward side, travel of the traveling vehicle body 2 is resumed. As a matter of course, in a state in which the subshift control lever 37 is operated to the neutral position and the driving force is not transmitted to the travel system, driving does not start until the subshift control lever 37 is operated to the position where driving transmission is performed. don't

Claims (3)

A steering member 35 for steering the aircraft, a position information acquisition device 200 for obtaining positional coordinates of the aircraft, and an automatic straight-line device 205 for operating the steering member 35 to drive the aircraft in a straight line. In the work vehicle,
Acquisition of a reference position serving as a reference for straight traveling and on/off of the automatic straight travel device 205 are configured to be performed by one operation member 207,
The reference position includes a first reference point (A) and a second reference point (B), and according to a reference line (R) connecting the first reference point (A) and the second reference point (B), the automatic straight ahead device A work vehicle characterized in that straight driving by (205) is performed. According to claim 1,
A work vehicle characterized in that a reference position is obtained when the operating member 207 is operated in a first direction, and the automatic straight-ahead device 205 is turned on and off when the operating member 207 is operated in the second direction. According to claim 1 or 2,
A work vehicle characterized in that the deletion of the acquired reference position is performed by manipulating an operating member (207).

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