Patent Description:
Conventionally, the working vehicle disclosed in <CIT> has been known.

The working vehicle disclosed in <CIT> has a vehicle body capable of traveling using either manual steering or automatic steering, the manual steering being performed with operation by the operator and the automatic steering being automatically performed without operation by the operator.

In the working vehicle disclosed in <CIT>, an operation member to perform an operation relating to automatic steering is disposed in the vicinity of the steering wheel forward of the operator's seat. Thus, there is a problem in which it is difficult to perform operation relating to automatic steering when the operator looks rearward to perform a work.

<CIT> discloses an electronic control system for autonomous driving which autonomously drives a vehicle body, the system comprising: an obstacle detection module which detects whether an obstacle is present; and a contact avoidance control unit which, when the obstacle detection module has detected an obstacle, carries out contact avoidance control for avoiding contact with the obstacle.

As described in <CIT>, a seat has a backrest arranged in a longitudinal direction of a seat surface, and an armrest arranged parallel to the seat surface. An arm support and an operating element arranged in rear and front regions of the armrest in the longitudinal direction. The arm support is supported over a guiding device at a base part of the armrest. The guiding device is formed such that the arm support is freely movable in a limited longitudinal displacement region along the longitudinal direction and/or in a limited side displacement region with respect to the base part.

<CIT> relates to a work vehicle with an inertia measurement device that measures inertia information of the vehicle body; a rear axle that supports a rear wheel for traveling; and a transmission case that turnably supports the rear axle. The inertia measurement device is disposed in a location overlapping with the transmission case in plan view.

<CIT> discloses a work vehicle comprising an electronic control system for vehicle automatic operation in which a vehicle is automatically operated. The electronic control system includes: a plurality of obstacle detection modules for detecting whether an obstacle is present or not; and a contact avoidance control unit for performing contact avoidance control for avoiding coming into contact with the obstacle when the obstacle is detected by the obstacle detection modules. The obstacle detection modules include a plurality of obstacle search instruments that are arranged to be separated into a front-end part of the vehicle and right and left side parts of the vehicle so that a front side and right and left sides of the vehicle can be areas to be searched.

<CIT> addresses the problem of how to provide a combine harvester which can improve the operability of the first and second switches while preventing the misoperation of those switches, and can improve the operability of a steering lever. A combine harvester is characterized by disposing the steering lever for steering a machine frame in the front portion of a cab and disposing the first and second switches for operating in mutually opposite directions on the different surfaces of an operation portion for the steering lever.

<CIT> pertains to a work vehicle provided with a vehicle body capable of travelling; a steering handle which is rotated to steer the vehicle body; and a steering switch for steering the vehicle body, which is provided separately from the steering handle. The steering switch may be a switch which is pressed or slid to steer the vehicle body.

In view of the above-described problem, an object of the present invention is to provide a working vehicle in which the operator can easily perform operation relating to automatic steering even while looking rearward. For solving the problem, a working vehicle according to independent claim <NUM> is provided. Further embodiments are disclosed in dependent claims.

A working vehicle according to one aspect of the present invention includes an operator's seat on which an operator sits, a vehicle body configured to travel selectively using either manual steering or automatic steering, the manual steering being performed manually by the operator, and the automatic steering being performed on the basis of a position of the vehicle body detected by a positioning device without manual operation by the operator, and a first operation member disposed on a lateral side of the operator's seat operably to perform an operation relating to the automatic steering, the first operation member being configured to be operated to selectively start or terminate the automatic steering during rearward traveling of the vehicle body or to correct the position of the vehicle body during rearward traveling of the vehicle body.

Also, the working vehicle further includes a second operation member disposed in front of the operator's seat operably to perform an operation relating to the automatic steering, the second operation member having the same function as that of the first operation member.

Also, the working vehicle further includes a console disposed on the lateral side of the operator's seat; and an armrest disposed between the console and the operator's seat, wherein the first operation member is disposed on an upper portion of the console and at a position higher than the armrest.

Also, the first operation member is disposed outward in a vehicle width direction from a fore-and-aft central portion of the armrest or the vicinity thereof.

Also, the first operation member is configured to be operated by the operator sitting on the operator's seat with his/her elbow on the armrest.

Also, the first operation member is disposed rearward relative to a front end of the operator's seat and forward relative to a rear end of the operator's seat.

Also, the second operation member is disposed on an opposite side of a central portion of the operator's seat from the first operation member.

Also, the first operation member is configured to be operated to selectively start or terminate the automatic steering during forward traveling of the vehicle body or to correct the position of the vehicle body during forward traveling of the vehicle body.

According to the above-described structure, since the first operation member is disposed on the lateral side of the operator's seat, the operator can easily perform operation relating to automatic steering even while looking rearward.

In the following, one embodiment of the present invention is described with reference to the drawings as appropriate.

<FIG> is a side view depicting one embodiment of a working vehicle <NUM>. In the present embodiment, the working vehicle <NUM> is a tractor. However, the working vehicle <NUM> is not limited to a tractor but may be an agricultural machine (agricultural vehicle), such as a combine or a transplanter, or may be a construction machine (construction vehicle) such as a loader, or the like.

By using <FIG> and so forth, the tractor (working vehicle) <NUM> is described. In the following, description is made by taking a front side of an operator sitting on an operator's seat <NUM> of the tractor <NUM> as forward, a rear side of the operator as rearward, a left side of the operator as leftward, and a right side of the operator as rightward. Also, description is made by taking a horizontal direction, which is a direction orthogonal to a fore-and-aft direction of the working vehicle <NUM>, as a vehicle body width direction. Also, description is made by taking a direction from a central portion toward a right portion or a left portion of the tractor <NUM> in the vehicle body width direction as outward in a vehicle width direction. In other words, the outward in the vehicle width direction is one vehicle body width direction away from the width directional center of the tractor <NUM>. A direction opposite to outward in the width direction is described as inward in the vehicle width direction. In other words, the inward in the vehicle width direction is the other vehicle body width direction approaching the width directional center of the tractor <NUM>.

As depicted in <FIG>, the tractor <NUM> includes a vehicle body <NUM>, a prime mover <NUM>, a transmission <NUM>. The vehicle body <NUM> has a traveling device <NUM> and is capable of traveling. The traveling device <NUM> is a device having front wheels 7F and rear wheels 7R. The front wheels 7F may be of a tire type or a crawler type. Also, the rear wheels 7R may be of a tire type or a crawler type.

The prime mover <NUM> is a diesel engine, electric motor, or the like and, in this embodiment, is configured of a diesel engine. The speed shifter <NUM> is capable of switching the driving force of the traveling device <NUM> by speed shifting, and is also capable of switching between forward traveling and rearward traveling of the traveling device <NUM>. A cabin <NUM> is mounted on the vehicle body <NUM>. Also, the operator's seat <NUM> is provided on the vehicle body <NUM>. The operator's seat <NUM> is disposed at a rear portion of the cabin interior. A steering wheel <NUM> is provided forward of the operator's seat <NUM>.

Also, a coupling portion <NUM> is provided at a rear portion of the vehicle body <NUM> configured of a three-point linkage mechanism or the like. The working device <NUM> is attachable to and detachable from the coupling portion <NUM>. By coupling the working device <NUM> to the coupling portion <NUM>, the working device <NUM> can be towed by the vehicle body <NUM>. The working device <NUM> is a tiller for tilling, a fertilizer spreader for spreading fertilizer, an agricultural chemical spreader for spreading agricultural chemicals, a harvester for harvesting, a mower for mowing grass or the like, a ridger for ridging, or the like, and is a device for performing a work (ground work) on a land such as an agricultural field.

As depicted in <FIG>, the transmission <NUM> includes a main shaft (propeller shaft) 5a, a main speed shifting unit 5b, a sub-speed shifting unit 5c, a shuttle unit 5d, a PTO power transmission unit 5e, and a front speed shifting unit 5f. The propeller shaft 5a is rotatably supported by a housing case (transmission case), and power from the crank shaft of the prime mover <NUM> is transmitted to the propeller shaft 5a. The main speed shifting unit 5b has a plurality of gears and a shifter for changing connection of the gears. By changing the connection (engagement) of the plurality of gears as appropriate with the shifter, the main speed shifting unit 5b changes and outputs rotation inputted from the propeller shaft 5a (changes speed).

Similar to the main speed shifting unit 5b, the sub-speed shifting unit 5c has a plurality of gears and a shifter for changing connection of the gears. By changing the connection (engagement) of the plurality of gears as appropriate with the shifter, the sub-speed shifting unit 5c changes rotation speed and outputs the speed-changed rotation inputted from the main speed shifting unit 5b.

The shuttle unit 5d has a shuttle shaft <NUM> and a forward-rearward traveling switching unit <NUM>. The power outputted from the sub-speed shifting unit 5c is transmitted to the shuttle shaft via gears and the like. The forward-rearward traveling switching unit <NUM> includes, for example, a hydraulic clutch or the like, which is clutched on and off to switch the rotating direction of the shuttle shaft <NUM>, that is, set whether forward traveling or rearward traveling of the tractor <NUM>. The shuttle shaft <NUM> is connected to a rear-wheel differential device 20R. The rear-wheel differential device 20R rotatably supports rear axles 21R to which the rear wheels 7R are attached.

The PTO power transmission unit 5e has a PTO propeller shaft <NUM> and a PTO clutch <NUM>. The PTO propeller shaft <NUM> is rotatably supported, and is capable of transmitting power from the propeller shaft 5a. The PTO propeller shaft <NUM> is connected to a PTO shaft <NUM> via gears or the like. The PTO clutch <NUM> is, for example, a hydraulic clutch or the like, which is configured to be engaged and disengaged to switch a transmission state between a state of transmitting power of the propeller shaft 5a to the PTO propeller shaft <NUM> and a state of not transmitting power of the propeller shaft 5a to the PTO propeller shaft <NUM>.

The front speed shifting unit 5f has a first clutch <NUM> and a second clutch <NUM>. The first clutch <NUM> and the second clutch <NUM> are capable of transmitting power from the propeller shaft 5a and power from the shuttle shaft <NUM> is transmitted via gears and a line shaft. Power from the first clutch <NUM> and the second clutch <NUM> can be transmitted via a front line shaft <NUM> to a front axle shaft 21F. Specifically, the front line shaft <NUM> is connected to a front-wheel differential device 20F, and the front-wheel differential device 20F rotatably supports the front axle shafts 21F to which the front wheels 7F are attached.

The first clutch <NUM> and the second clutch <NUM> are hydraulic clutches or the like. A fluid passage connected to the first clutch <NUM> is connected to a first actuation valve <NUM> which is supplied with hydraulic fluid delivered from a hydraulic pump <NUM>. The first clutch <NUM> is switched between a clutch-on state and a clutch-off state depending on the opening degree of the first actuation valve <NUM>. A fluid passage connected to the second clutch <NUM> is connected to a second actuation valve <NUM>. The second clutch <NUM> is switched between a clutch-on state and a clutch-off state depending on the opening degree of the second actuation valve <NUM>. The first actuation valve <NUM> and the second actuation valve <NUM> are, for example, solenoid two-position change-over valves having solenoids each of which is excited and unexcited to switch the corresponding first or second actuation valve <NUM> or <NUM> between the clutch-on state and the clutch-off state.

When the first clutch <NUM> is in the clutch-off state and the second clutch <NUM> is in the clutch-on state, power of the shuttle shaft <NUM> is transmitted via the second clutch <NUM> to the front wheels 7F. This makes a four-wheel drive (4WD) mode in which the front wheels 7F and the rear wheels 7R are driven by the driving power, and the rotation speeds of the front wheels 7F and the rear wheels 7R are substantially equal to each other (an equal-speed 4WD state). On the other hand, when the first clutch <NUM> is in the clutch-on state and the second clutch <NUM> is in the clutch-off state, the vehicle is set in a four-wheel drive mode in which the rotation speed of the front wheels 7F becomes faster than the rotation speed of the rear wheels 7R (am acceleration 4WD state). Also, when the first clutch <NUM> and the second clutch <NUM> are in the clutch-off state, power of the shuttle shaft <NUM> is not transmitted to the front wheels 7F, and thus the vehicle is set in a two-wheel drive (2WD) mode in which only the rear wheels 7R are driven by the driving power.

As depicted in <FIG>, the tractor <NUM> includes a positioning device <NUM>. The positioning device <NUM> is capable of detecting its own position (positioning information including latitude and longitude) with a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, HO-KUTO, GALILEO, and MICHIBIKI. That is, the positioning device <NUM> receives a satellite signal transmitted from the positioning satellite (such as the position of the positioning satellite, transmission time, and correction information), and detects the position (for example, latitude and longitude) based on the satellite signal. The positioning device <NUM> has a receiver <NUM> and an inertial measurement unit (IMU: Inertial Measurement Unit) <NUM>. The receiver <NUM> is a device having an antenna or the like to receive satellite signals transmitted from the positioning satellite, and is attached to the vehicle body <NUM> separately from the inertial measurement unit <NUM>. In this embodiment, the receiver <NUM> is disposed above the roof of the cabin <NUM> and is attached to the cabin <NUM> via a supporting component. Note that the attachment location of the receiver <NUM> is not limited by the embodiment.

The inertial measurement unit <NUM> has an acceleration sensor to detect acceleration, a gyro sensor to detect angular velocity, and so forth. The vehicle body <NUM> is provided, for example, below the steering wheel <NUM>, below the operator's seat <NUM>, or the like. By the inertial measurement unit <NUM>, the roll angle, pitch angle, yaw angle, and so forth of the vehicle body <NUM> can be detected.

As depicted in <FIG>, the tractor <NUM> includes a steering device <NUM>. The steering device <NUM> is a device capable of performing manual steering of the vehicle body <NUM> with steering operation by the operator and automatic steering of the vehicle body <NUM> without steering operation by the operator. Therefore, the vehicle body <NUM> is capable of traveling by using either manual steering with steering operation by the operator or automatic steering without steering operation by the operator.

The steering device <NUM> has the steering wheel <NUM> and a steering shaft (rotation shaft) <NUM> rotatably supporting the steering wheel <NUM>. Also, the steering device <NUM> has an assist mechanism (power steering device) <NUM>. The assist mechanism <NUM> assists the rotation of the steering shaft <NUM> (steering wheel <NUM>) with hydraulic pressure or the like. The assist mechanism <NUM> includes the hydraulic pump <NUM>, a control valve <NUM> to which a hydraulic fluid delivered from the hydraulic pump <NUM> is supplied, and a steering cylinder <NUM> which is actuated by the control valve <NUM>. The control valve <NUM> is, for example, a three-position change-over valve that is switchable with the movement of a spool or the like, and is switched in accordance with the steering direction (rotating direction) of the steering shaft <NUM>. The steering cylinder <NUM> is connected to an arm (knuckle arm) for changing the orientation of the front wheels 7F.

Therefore, when the operator holds and operates the steering wheel <NUM> in one direction or the other direction, the switching position and the opening degree of the control valve <NUM> are switched in accordance with the rotating direction of the steering wheel <NUM> and, with the steering cylinder <NUM> extending or contracting to left or right in accordance with the switching position and the opening degree of the control valve <NUM>, the steering direction of the front wheels 7F can be changed. That is, in the vehicle body <NUM>, the forwarding direction can be changed to left or right by manual steering of the steering wheel <NUM>.

As depicted in <FIG>, the steering device <NUM> has an automatic steering mechanism <NUM>. The automatic steering mechanism <NUM> is a mechanism for automatic steering of the vehicle body <NUM>, automatically steering the vehicle body <NUM> based on the position of the vehicle body <NUM> (vehicle-body position) detected by the positioning device <NUM>. The automatic steering mechanism <NUM> includes a steering motor <NUM> and a gear mechanism <NUM>. The steering motor <NUM> is a motor capable of controlling the rotating direction, rotation speed and rotation angle, and so forth based on the vehicle-body position. The gear mechanism <NUM> includes a gear, which is provided on the steering shaft <NUM> to rotate together with the steering shaft <NUM>, and a gear, which is provided on the rotation shaft of the steering motor <NUM> to rotate together with the rotation shaft. When the rotation shaft of the steering motor <NUM> rotates, the steering shaft <NUM> is automatically rotated (revolved) via the gear mechanism <NUM> to change the steering direction of the front wheels 7F so that the vehicle-body position matches a scheduled traveling line L2 (refer to <FIG>).

As depicted in <FIG>, to perform automatic steering, a traveling reference line L1 is first set by a multi switch <NUM> before performing automatic steering. After the traveling reference line L1 is set, the scheduled traveling line L2 parallel to the traveling reference line L1 is set, thereby allowing automatic steering to be performed. In automatic steering, steering of the tractor <NUM> (vehicle body <NUM>) in the forwarding direction is automatically performed so that the vehicle-body position measured by the positioning device <NUM> matches the scheduled traveling line L2.

As depicted in <FIG>, the cabin <NUM> has a plurality of front pillars <NUM>, rear pillars <NUM>, and quarter pillars (center pillars) <NUM>. The plurality of front pillars <NUM> include a first front pillar <NUM> and a second front pillar 71R disposed at a front portion of the cabin <NUM> so as to be spaced in a machine width direction. The plurality of rear pillars <NUM> include a first rear pillar <NUM> and a second rear pillar 72R disposed at a rear portion of the cabin <NUM> so as to be spaced in the machine width direction. The plurality of quarter pillars <NUM> include a first quarter pillar <NUM> and a second quarter pillar 73R disposed between the front pillars <NUM> and the rear pillars <NUM> and spaced from each other in the machine width direction. A front glass <NUM> is provided between the first front pillar <NUM> and the second front pillar 71R. A rear glass <NUM> is provided between the first rear pillar <NUM> and the second rear pillar 72R. Loading/unloading doors <NUM> are provided between the front pillars <NUM> and the quarter pillars <NUM>. Rear side glasses <NUM> are provided between the quarter pillars <NUM> and the rear pillars <NUM>.

The operator's seat <NUM> has a seat portion 10a on which the operator sits and a backrest portion 10b which the operator sits with his/her back against. On a lateral side (rightward) of the operator's seat <NUM>, an armrest <NUM> and a console <NUM> are disposed so as to be aligned laterally. The armrest <NUM> is disposed between the console <NUM> and the operator's seat <NUM>. The armrest <NUM> has an armrest portion <NUM> at a rear portion thereof. The armrest <NUM> is provided at a front portion thereof with a position lever <NUM> for raising and lowering the working device <NUM> and a speed-shift member <NUM> for performing operation of changing a speed stage of the transmission <NUM>. The console <NUM> is an interior cover formed as a part of the interior of the cabin <NUM>. Various switches <NUM> are disposed on the console <NUM>.

As depicted in <FIG>, on the lateral side of the operator's seat <NUM>, a first operation member <NUM> for performing operation relating to automatic steering is disposed. The lateral side of the operator's seat <NUM> is, as indicated by a one-dot-chain line X1 in <FIG>, an outward side relative to the operator's seat <NUM> in the vehicle width direction. In the present embodiment, the first operation member <NUM> is disposed rightward of the operator's seat <NUM>. Note that the first operation member <NUM> may be disposed leftward of the operator's seat <NUM>.

As depicted in <FIG>, the first operation member <NUM> is disposed on the console <NUM>. The console <NUM> has a front portion positioned outward of the steering wheel <NUM> in the vehicle width direction and a rear end portion positioned rearward relative to the second rear pillar 72R and in the vicinity of the rear glass <NUM>. The first operation member <NUM> is disposed between a front end 77a and a rear end 77b of the console. In the present embodiment, the first operation member <NUM> is disposed in the vicinity of the fore-and-aft center (including the center, and the same goes for the following) of the console <NUM>. On an assumption that the member includes, for example, a front portion, a rear portion, and an intermediate portion between the front portion and the rear portion, the vicinity of the center is a portion corresponding to the intermediate portion.

Note that the first operation member <NUM> may be disposed at a front portion or a rear portion of the console <NUM>.

As depicted in <FIG>, the first operation member <NUM> is disposed on an upper portion of the console <NUM>. In detail, the first operation member <NUM> is disposed on an upper surface side of the console <NUM>. Note that the first operation member <NUM> may be disposed on a surface on an inner side of the console <NUM> in the vehicle width direction. Also, the upper portion of the console <NUM> is at a position higher than the seat portion 10a and higher than the armrest <NUM>. That is, the first operation member <NUM> is disposed above the seat portion 10a and above the armrest <NUM>.

As depicted in <FIG>, the first operation member <NUM> is disposed rearward relative to a front end (front end of the seat portion 10a) 10c of the operator's seat <NUM> and forward relative to a rear end 10d (rear end of the backrest portion 10b) of the operator's seat <NUM>. In detail, the first operation member <NUM> is disposed rearward relative to the front end 10c of the operator's seat 10a and forward relative to a rear end 10e of the seat portion 10a. In the present embodiment, the first operation member <NUM> is positioned outward in the vehicle width direction (rightward) from a portion in the vicinity of the fore-and-aft center of the seat portion 10a. Note that the first operation member <NUM> may be disposed outward in the vehicle width direction of a front portion of the seat portion 10a or outward in the vehicle width direction of a rear portion of the seat portion 10a. Also, the first operation member <NUM> may be disposed forward from the operator's seat <NUM> or rearward from the operator's seat <NUM>.

As depicted in <FIG>, the armrest <NUM> is disposed rearward relative to a front end 77a of the console <NUM> and forward relative to a rear end 77b of the console <NUM>. A front end 76a of the armrest <NUM> is positioned forward relative to the front end 10c of the seat portion 10a, and a rear end 76b of the armrest <NUM> is positioned outward in the vehicle width direction of a lower portion of the backrest portion 10b. The first operation member <NUM> is disposed outward in the vehicle width direction of the armrest <NUM>. In detail, the first operation member <NUM> is disposed outward in the vehicle width direction (rightward) from a portion the vicinity of the fore-and-aft center of the armrest <NUM>. The armrest portion <NUM> extends from a rear portion of the armrest <NUM> to the vicinity of the fore-and-aft center thereof.

Note that the first operation member <NUM> may be provided on the armrest <NUM>. In this case, the first operation member <NUM> is disposed forward relative to the armrest portion <NUM> and on an upper surface side of the armrest <NUM>. This is not meant to be restrictive.

By the operator gripping the steering wheel <NUM> with one hand (left hand), the first operation member <NUM> is operable with the other hand (right hand). Also, the first operation member <NUM> is operable by the operator sitting on the operator's seat <NUM> even in a state where the operator puts his or her elbow on the armrest portion <NUM> of the armrest <NUM>. This allows the operator to easily operate the first operation member <NUM>.

The first operation member <NUM> is, in the present embodiment, a first steering switching member which either starts or terminates automatic steering. Also, the first steering switching member <NUM> is a switch to be switched between a manual steering position and an automatic steering position. The first steering switching member <NUM> is formed of, for example, an ON/OFF switch such as a push button switch or seesaw switch, which is configured to output a signal of start of automatic steering when undergoing ON operation (turn-on operation) and outputting a termination of automatic steering when undergoing OFF operation (turn-off operation). That is, an automatic steering function becomes active by turn-on operation of the first steering switching member <NUM>, and the automatic steering function becomes not active by turn-off operation of the first steering switching member <NUM> to enable manual steering.

Note that the automatic steering function is active when a mode switch <NUM>, which will be described further below, is turned on and operated, and is not active even with turn-on operation of the first steering switching member <NUM> when the mode switch <NUM> is turned off.

Since the first steering switching member <NUM> is disposed on the lateral side of the operator's seat <NUM>, the operation of start or termination of automatic steering can be easily performed when the operator faces forward to perform a work, and also when the operator looks rearward to perform a work. Also, when a ground work is performed, this may be performed in one way (in one direction without swiveling at <NUM> degrees). In this case, during rearward traveling by automatic steering when the operator looks rearward, the operator can easily perform an operation of starting or terminating automatic steering with the first steering switching member <NUM>.

As depicted in <FIG>, a front cover (operation console cover) <NUM> and a steering column <NUM> are disposed forward of the operator's seat <NUM>. As depicted in <FIG>, the front cover <NUM> is provided with a display (automatic steering monitor) <NUM> and a meter panel <NUM>. The display <NUM> is capable of displaying various information regarding the tractor <NUM> (at least driving information regarding driving of the tractor <NUM>). Also, by using the display <NUM>, it is possible to set a work type, which is a type of the working device <NUM>; a work width, which is the width of the working device <NUM>; a wrap width, which is an overlap width of an adjacent worked land, and so forth. The meter panel <NUM> is capable of displaying the driving information such as fuel, water temperature, engine rotation speed, and so forth.

As depicted in <FIG>, a plurality of second operation members <NUM> for performing operation relating to automatic steering are provided forward of the operator's seat <NUM>. The plurality of second operation members <NUM> are disposed in the vicinity of the steering wheel <NUM>. As depicted in <FIG>, the plurality of second operation members <NUM> include a second steering switching member <NUM>, the mode switch <NUM>, the multi switch <NUM>, and a correction switch <NUM>. The second steering switching member <NUM>, the multi switch <NUM>, and the correction switch <NUM> are disposed on the steering column <NUM>, and the mode switch <NUM> is disposed on the front cover <NUM>.

The second steering switching member <NUM> is an operation member having a function identical to a function of the first steering switching member <NUM>. That is, the second steering switching member <NUM> is a switch which selectively starts or terminates automatic steering. Therefore, starting and terminating automatic steering (switching between manual steering and automatic steering) can be performed with either of the first steering switching member <NUM> and the second steering switching member <NUM>. The second steering switching member <NUM> is formed of a lever-type switch turnable between two positions in a vertical direction, and outputs a signal for start of automatic steering when switched downward (undergoing ON operation) and outputs a signal for termination of automatic steering when switched upward (undergoing OFF operation).

Note that the automatic steering function is not active even with turn-on operation of the second steering switching member <NUM> when the mode switch <NUM> undergoes turn-off operation.

As depicted in <FIG>, the second steering switching member <NUM> is disposed forward of a left portion of the operator's seat <NUM>. That is, the second steering switching member <NUM> is disposed on a side opposite to the first operation member <NUM> with respect to a vehicle body width directional central portion of the operator's seat.

Therefore, while the operator can easily perform the operation of the second steering switching member <NUM> with the left hand, since the first steering switching member <NUM> is disposed rightward of the operator's seat <NUM>, the operator can easily perform the operation of the first steering switching member <NUM> with the right hand. That is, the operator can easily perform operations of start and termination of automatic steering with either of the left hand and the right hand. Also, the operations of start and termination of automatic steering can be performed with either of the first steering switching member <NUM> and the second steering switching member <NUM> for automatic steering at the time of forward traveling and automatic steering at the time of rearward traveling, thereby allowing various orientations and states of the operator to be supported.

The mode switch <NUM> is a switch for enabling operation relating to automatic steering. Specifically, the mode switch <NUM> is a switch for enabling setting (registration) of the traveling reference line L1 with the multi switch <NUM> and the function (automatic steering function) of the first steering switching member <NUM> and the second steering switching member <NUM>. In detail, the mode switch <NUM> is switchable ON and OFF, so that the mode switch <NUM> outputs a signal for enabling setting of the traveling reference line L1 with the multi switch <NUM> and the function of the first steering switching member <NUM> and the second steering switching member <NUM> when being switched ON (undergoing turn-on operation) and outputs a signal for disabling setting of the traveling reference line L1 with the multi switch <NUM> and the function of the first steering switching member <NUM> and the second steering switching member <NUM> when being switched OFF (undergoing turn-off operation).

The multi switch <NUM> is a switch which allows a revolving operation and a push operation. The multi switch <NUM> is connected to the display device <NUM>, and can operate the display <NUM> when the mode switch <NUM> does not undergo turn-on operation. For example, any of various functional items can be selected by revolving (performing revolving operation of) the multi switch <NUM>, and the selected item can be executed by pushing (performing push operation of) the multi switch <NUM>.

Also, when the mode switch <NUM> is undergoing turn-on operation, the traveling reference line L1 can be set with the multi switch <NUM>. In detail, as depicted in <FIG>, the multi switch <NUM> outputs a signal for setting of a start point P10 of the traveling reference line L1 with a first push operation, and outputs a signal for setting of an end point P11 of the traveling reference line L1 with a second push operation. That is, the multi switch <NUM> also serves as a registration switch for setting a start position (start point P10) and an end position (end point P11) of the traveling reference line L1.

Here, with reference to <FIG>, a method of setting the traveling reference line L1 and switching of the automatic steering are described. To set the traveling reference line L1, before performing automatic steering, when the tractor <NUM> (vehicle body <NUM>) is first moved to a predetermined position in an agricultural field (S1) and the operator operates the multi switch <NUM> provided on the tractor <NUM> at the predetermined position (S2), the vehicle-body position measured by the positioning device <NUM> is set as the start point P10 of the traveling reference line L1 (S3). Next, when the tractor <NUM> (vehicle body <NUM>) is moved from the start point P10 of the traveling reference line L1 (S4) and the operator operates the multi switch <NUM> at a predetermined position (S5), the vehicle-body position measured by the positioning device <NUM> is set as the end point P11 of the traveling reference line L1 (S6). Therefore, a straight line connecting the start point P10 and the end point P11 is set as the traveling reference line L1.

After the traveling reference line L1 is set (after S6), for example, when the tractor <NUM> (vehicle body <NUM>) is moved to a location different from the location where the traveling reference line L1 is set (S7) and the operator performs turn-on operation of the first steering switching member <NUM> or the second steering switching member <NUM> (S8), the scheduled traveling line L2 is set, which is a straight line parallel to the traveling reference line L1 (S9). After the scheduled traveling line L2 is set, automatic steering is started, and the forwarding direction of the tractor <NUM> (vehicle body <NUM>) varies along the scheduled traveling line L2. For example, the front wheels 7F are steered to right when the current vehicle-body position is on the left side with respect to the scheduled traveling line L2, and the front wheels 7F are steered to left when the current vehicle-body position is on the right side with respect to the scheduled traveling line L2.

Note that during automatic steering, the traveling speed (vehicle speed) of the tractor <NUM> (vehicle body <NUM>) can be changed by the operator manually changing the operation amount of an accelerator (accelerator pedal, accelerator lever) <NUM> (refer to <FIG>) provided in the tractor <NUM> or changing the speed stage of the transmission <NUM> by using the speed-shift member (speed-shift lever, speed-shift switch) <NUM> (refer to <FIG>).

Also, after automatic steering starts, the operator can terminate automatic steering when performing turn-off operation of the first steering switching member <NUM> or the second steering switching member <NUM> at any location. That is, the end point of the scheduled traveling line L2 can be set by terminating automatic steering with turn-off operation of the first steering switching member <NUM> or the second steering switching member <NUM>. That is, the length from the start point to the end point of the scheduled traveling line L2 can be set longer or shorter than the traveling reference line L1. In other words, the scheduled traveling line L2 is not associated with the length of the traveling reference line L1, and the scheduled traveling line L2 allows traveling at a distance longer than the length of the traveling reference line L1 during automatic steering.

The correction switch <NUM> is a switch for correcting the vehicle-body position (longitude and latitude) measured by the positioning device <NUM>. That is, the correction switch <NUM> is a switch for correcting the vehicle-body position (referred to as calculated vehicle-body position) calculated with a satellite signal (position of the positioning satellite, transmission time, correction information, and so forth) and measurement information regarding measurement items (acceleration and angular velocity) measured by the inertial measurement device <NUM>.

For example, a pushable push switch serves as the correction switch <NUM>, and the correction amount is set based on the number of times of operation using the correction switch <NUM>. The correction switch <NUM> has a first portion for issuing an instruction for correction of the vehicle-body position corresponding to one width directional side, i.e., a left side, of the vehicle body <NUM>, and a second portion for issuing an instruction for correction of the vehicle-body position corresponding to the other width directional side, i.e., a right side, of the vehicle body <NUM>. Every time the first portion is pushed, the correction amount corresponding to the left side of the vehicle body <NUM> (left correction amount) is incremented. Every time the second portion is pushed, the correction amount corresponding to the right side of the vehicle body <NUM> (right correction amount) is incremented.

Note that a slidable slide switch may serve as the correction switch <NUM>. In this case, the correction amount is set based on the operation amount of the correction switch <NUM>.

For example, if an error occurs in positioning by the positioning device <NUM> due to various influences even though an actual position of the tractor <NUM> is not deviated with respect to the scheduled traveling line L2 and the vehicle-body position detected by the positioning device <NUM> is deviated rightward from the scheduled traveling line L2 (actual position) and the deviation amount is kept, the tractor <NUM> determines that a deviation occurs between the calculated vehicle-body position and the scheduled traveling line L2, and the tractor <NUM> is steered leftward so as to eliminate the deviation amount between the calculated vehicle-body position and the scheduled traveling line L2. Then, the actual position of the tractor <NUM> is shifted leftward from the scheduled traveling line L2. In this case, assume that the operator notices that the tractor <NUM> is deviated leftward from the scheduled traveling line L2 and operates the correction switch <NUM> to increment the right correction amount from zero. Then, the right correction amount is added to the calculated vehicle-body position, so that the vehicle-body position after correction (corrected vehicle-body position) becomes substantially identical to the actual position. That is, by using the correction switch <NUM>, the vehicle-body position by the positioning device <NUM> can be corrected so as to eliminate the occurring deviation amount. Also, by operating the correction switch <NUM>, steering can be performed separately from the steering wheel <NUM>. That is, the correction switch <NUM> also serves as a steering member for steering the vehicle body <NUM>.

Description has been made above to the case in which the vehicle-body position detected by the positioning device <NUM> deviates rightward from the scheduled traveling line L2. On the other hand, when the vehicle-body position detected by the positioning device <NUM> deviates leftward from the scheduled traveling line L2, the correction switch <NUM> is operated to increment the left correction amount from zero, thereby adding the left correction amount to the calculated vehicle-body position and making the vehicle-body position after correction (corrected vehicle-body position) substantially identical to the actual position.

While the first operation member <NUM> is a first steering switching member in the above description, this is not meant to be restrictive. For example, the first operation member <NUM> may be a correction switch (another correction switch) having the same function as that of the correction switch <NUM>. That is, the correction switch <NUM> may be provided forward of the operator's seat <NUM> and another correction switch may be provided on a lateral side of the operator's seat <NUM>. Also, the first operation member <NUM> may be a switch (another mode switch) having the same function as that of the mode switch <NUM> or a switch (another multi switch) having the same function as that of the multi switch <NUM>. Also, a plurality of said first operation members <NUM> may be provided. In this case, the plurality of first operation members <NUM> include two or more switches from among the first steering switching member, another correction switch, another mode switch, and another multi switch.

As depicted in <FIG>, the tractor <NUM> includes a plurality of controllers <NUM>. The plurality of controllers <NUM> are devices to perform control over a traveling system, control over a working system, calculation of the vehicle-body position, and so forth in the tractor <NUM>. The plurality of controllers <NUM> are a first controller 60A, a second controller 60B, and a third controller 60C.

The first controller 60A receives a satellite signal (reception information) received by the receiver <NUM> and measurement information (acceleration and angular velocity) obtained by measurement by the inertial measurement device <NUM> and finds the vehicle-body position based on the received information and the measurement information.

Also, the first controller 60A has a reference registering unit <NUM>. The reference registering unit <NUM> includes an electric or electronic circuit provided in the first controller 60A, a program stored in a CPU or the like, and/or so forth. As described above, the reference registering unit <NUM> registers the traveling reference line L1, that is, sets the start point P10 and the end point P11. In a situation in which the tractor <NUM> is caused to travel by manual steering with the mode switch <NUM> undergoing turn-on operation, when the multi switch <NUM> is first operated to be pushed, the reference registering unit <NUM> sets the vehicle-body position as the start point P10 of the traveling reference line L1 and, next, when the multi switch <NUM> is operated to be pushed, sets the vehicle-body position as the end point P11 of the traveling reference line L1.

The second controller 60B has an automatic steering control unit <NUM>. The automatic steering control unit <NUM> includes an electric or electronic circuit provided in the second controller 60B, a program stored in a CPU or the like, and/or so forth. The automatic steering control unit <NUM> controls the steering motor <NUM> of the automatic steering mechanism <NUM> so that the vehicle body <NUM> travels along the scheduled traveling line L2.

As depicted in <FIG>, when the first steering switching member <NUM> or the second steering switching member <NUM> is operated to be turned on, the automatic steering control unit <NUM> sets the scheduled traveling line L2 parallel to the traveling reference line L1. After setting the scheduled traveling line L2, the automatic steering control unit <NUM> keeps the rotation angle of the rotation shaft of the steering motor <NUM> when a deviation between the vehicle-body position and the scheduled traveling line L2 is smaller than a threshold value. When the deviation (positional deviation) between the vehicle-body position and the scheduled traveling line L2 is equal to or larger than the threshold value and the tractor <NUM> is positioned on the left side with respect to the scheduled traveling line L2, the automatic steering control unit <NUM> rotates the rotation shaft of the steering motor <NUM> so as to steer the tractor <NUM> rightward. That is, the automatic steering control unit <NUM> sets a rightward steering angle such as to zero the positional deviation. When the deviation between the vehicle-body position and the scheduled traveling line L2 is equal to or larger than the threshold value and the tractor <NUM> is positioned on the right side with respect to the scheduled traveling line L2, the automatic steering control unit <NUM> rotates the rotation shaft of the steering motor <NUM> so as to steer the tractor <NUM> leftward. That is, the automatic steering control unit <NUM> sets a leftward steering angle such as to zero the positional deviation.

In the above-described embodiment, the steering angle of the steering device <NUM> is changed based on the deviation between the vehicle-body position and the scheduled traveling line L2 in the above-described embodiment. Alternatively, when the azimuth of the scheduled traveling line L2 and an azimuth (vehicle-body azimuth) F1 of the tractor <NUM> (vehicle body <NUM>) in the forwarding direction (traveling direction) are different, that is, when an angle θg of the vehicle-body azimuth F1 with respect to the scheduled traveling line L2 is equal to or larger than a threshold value, the automatic steering control unit <NUM> may set a steering angle so that the angle θg becomes zero (the vehicle-body azimuth F1 matches the azimuth of the scheduled traveling line L2). Also, the automatic steering control unit <NUM> may set a final steering angle in automatic steering based on the steering angle calculated based on the deviation (positional deviation) and a steering angle calculated based on the azimuth (azimuth deviation). Setting of the steering angle in automatic steering in the above-described embodiment is one example and is not meant to be restrictive.

Also, while the automatic steering being performed by the automatic steering control unit <NUM>, when the accelerator <NUM> is operated, the second controller 60B changes the rotation speed of the prime mover <NUM> (prime mover rotation speed) in accordance with the operation amount of the accelerator <NUM>. Also, while the automatic steering is performed by the automatic steering control unit <NUM>, when the speed shift member <NUM> is operated, the second controller 60B changes the speed stage of the speed shifter <NUM>.

The third controller 60C causes the coupling portion <NUM> to be lifted up and down in accordance with the operation of an operating member provided on the periphery of the operator's seat <NUM>. Note that the first controller 60A, the second controller 60B, and the third controller 60C may be integrated. Also, the above-described control over the traveling system, control over the working system, and calculation of the vehicle-body position are not meant to be restrictive. As described above, by the controllers <NUM>, the tractor <NUM> (vehicle body <NUM>) can be automatically steered.

The above working vehicle <NUM> includes the operator's seat <NUM> on which the operator sits, the vehicle body <NUM> configured to travel selectively using either manual steering or automatic steering, the manual steering being performed manually by the operator, and the automatic steering being performed on the basis of a vehicle-body position detected by a positioning device without manual operation by the operator, and the first operation member <NUM> (first steering switching member) to perform an operation relating to the automatic steering, and the first operation member <NUM> is disposed on the lateral side of the operator's seat <NUM>.

According to this structure, since the first operation member <NUM> is disposed on the lateral side of the operator's seat <NUM>, the operator can easily perform operation relating to automatic steering even while looking rearward.

Also, the working vehicle includes the second operation member <NUM> disposed in front of the operator's seat <NUM> to perform an operation relating to automatic steering.

According to this structure, the operation relating to automatic steering can be performed with either of the first operation member <NUM> on the lateral side of the operator's seat <NUM> and the second operation member <NUM> forward of the operator's seat <NUM>.

Also, the first operation member <NUM> and the second operation member <NUM> have the same function.

According to this structure, regardless of whether the operator faces forward to work or looks rearward to work, the same operation relating to automatic steering can be performed with either of the first operation member <NUM> and the second operation member <NUM>.

Also, the first operation member <NUM> is an operation member to selectively start or terminate automatic steering.

According to this structure, the operator can easily select either start or termination of automatic steering even while looking rearward.

Also, the first operation member <NUM> may be a correction switch for making an instruction for correcting the position of the vehicle <NUM> detected by the positioning device <NUM>.

According to this structure, the operator can easily perform correction of the position of the vehicle <NUM> even while looking rearward.

Also, the first operation member <NUM> is disposed rearward relative to the front end of the operator's seat <NUM> and forward relative to the rear end thereof.

According to this structure, the first operation member <NUM> can be easily operated at the time of working by turning rearward.

Also, the second operation member <NUM> is disposed on an opposite side of the central portion of the operator's seat <NUM> from the first operation member <NUM>.

According to this structure, since the first operation member <NUM> and the second operation member <NUM> are distributed left and right with respect to the operator's seat <NUM>, for example, when the operation member <NUM> and the second operation member <NUM> are operation members having the same function, the operator can perform the same operation relating to automatic steering with either of the left hand and the right hand.

Claim 1:
A working vehicle, comprising:
- an operator's seat (<NUM>) on which an operator can sit; and
- a vehicle body (<NUM>) configured to travel selectively using either manual steering or automatic steering, the manual steering being performed manually by the operator, and the automatic steering being performed on the basis of a position of the vehicle body (<NUM>) detected by a positioning device (<NUM>) without manual operation by the operator;
characterized by comprising:
- a first operation member (<NUM>) disposed on a lateral side of the operator's seat (<NUM>) operably to perform an operation relating to the automatic steering, the first operation member (<NUM>) being configured to be operated to selectively start or terminate the automatic steering during rearward traveling of the vehicle body (<NUM>) or to correct the position of the vehicle body (<NUM>) during rearward traveling of the vehicle body (<NUM>).