Work vehicle

Abstract

To solve the problem that it is not always easy to utilize a convenient function in a conventional work vehicle, and specifically manual operation that is performed accompanying turning often requires considerable experience, in the conventional work vehicle.SOLUTION: A tractor is equipped with: a work mode selecting part 20 that selects at least a work mode; a tuning instructing part 30 that performs an instruction for at least starting turning; and a controller 10 that when the work mode is selected by the work mode selecting part 20 and when the instruction for starting turning is performed by the turning instructing part 30, starts turning control of making a wheel steering angle match a predetermined turning wheel steering angle.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to work vehicles such as tractors. [Background technology]

[0002] A known work vehicle includes a vehicle body having steering wheels, a steering wheel operated by a driver, a steering sensor that detects the amount of steering wheel operation, a steering device that steers the steering wheels, a control unit that controls the steering device in accordance with the detection value of the steering sensor, a work implement attached to the vehicle body, a lifting device that raises and lowers the work implement, and a lifting sensor that detects the lifting position of the lifting device, and when the lifting position of the lifting device detected by the lifting sensor is raised to or above a predetermined position, the control unit increases the steering ratio of the steering wheels by the steering device relative to the detection value of the steering sensor compared to when the lifting position of the lifting device is below the predetermined position (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-158461 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the inventor believes that the trend of considering the various needs of users and successively implementing convenient functions into work vehicles will continue to accelerate.

[0005] However, the inventors have noticed that conventional work vehicles are not necessarily easy to use when using convenient functions.

[0006] More specifically, the inventors have found that with conventional work vehicles, manual operations associated with turning often require considerable experience.

[0007] SUMMARY OF THE INVENTION In consideration of the above-mentioned problems inherent in the prior art, the present invention has an object to provide a work vehicle that can improve usability. [Means for solving the problem]

[0008] A first aspect of the present invention is a method for controlling a work mode selection unit that selects at least a work mode; a turn instruction unit that issues an instruction to start at least a turn; a controller that starts turning control to make a wheel steering angle coincident with a predetermined turning wheel steering angle when the turning instruction unit issues the instruction to start the turning operation in a case where the work mode is selected by the work mode selection unit; The work vehicle is characterized by being equipped with:

[0009] A second aspect of the present invention is the work vehicle according to the first aspect of the present invention, wherein the turning instruction unit is a switch that issues the instruction to turn at least one of left and right.

[0010] The third aspect of the present invention is a switch that issues the instruction to one of the left turn, the right turn, and turn-off, This is a second work vehicle of the present invention, characterized in that when the work mode is selected by the work mode selection unit, the instruction for either the left turn or the right turn is given by the turning instruction unit, and then the instruction for turning off is given by the turning instruction unit, the controller terminates the turning control and performs straight-ahead wheel steering angle recovery control to match the wheel steering angle with the straight-ahead wheel steering angle.

[0011] A fourth aspect of the present invention further includes a steering wheel, A third work vehicle of the present invention is characterized in that, when the work mode is selected by the work mode selection unit, when the instruction for either the left turn or the right turn is given by the turning instruction unit, the controller performs steering wheel angle cancellation control to ignore changes in the angle of the steering wheel, and then, when the instruction for turning off is given by the turning instruction unit, the controller completes the straight-ahead wheel steering angle recovery control to match the angle of the steering wheel with the straight-ahead steering wheel angle, and then releases the steering wheel angle cancellation control.

[0012] The fifth aspect of the present invention further includes a steering wheel, A third work vehicle of the present invention is characterized in that, when the work mode is selected by the work mode selection unit, when the instruction for either the left turn or the right turn is given by the turning instruction unit, the controller performs steering wheel angle lock control to fix the angle of the steering wheel at the straight-ahead steering wheel angle, and then, when the instruction for turning off is given by the turning instruction unit, the controller completes the straight-ahead wheel steering angle recovery control and then releases the steering wheel angle lock control.

[0013] The sixth aspect of the present invention is the work vehicle according to the fourth or fifth aspect of the present invention, characterized in that the time period from when the turning control is started until the wheel steering angle is made to coincide with the predetermined turning wheel steering angle is adjustable.

[0014] The seventh aspect of the present invention is the work vehicle according to the sixth aspect of the present invention, wherein said turning instruction unit is a blinker switch. [Effects of the Invention]

[0015] The first aspect of the present invention makes it possible to improve usability.

[0016] According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, it is possible to improve convenience.

[0017] According to the third aspect of the present invention, in addition to the effects of the second aspect of the present invention, it is possible to further improve convenience.

[0018] According to the fourth aspect of the present invention, in addition to the effect of the third aspect of the present invention, it is possible to reduce the burden on the worker.

[0019] According to the fifth aspect of the present invention, in addition to the effect of the third aspect of the present invention, it is possible to improve reliability.

[0020] According to the sixth aspect of the present invention, in addition to the effects of the fourth or fifth aspect of the present invention, it is possible to improve practicality.

[0021] According to the seventh aspect of the present invention, in addition to the effect of the sixth aspect of the present invention, it is possible to simplify the configuration. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a left side view of a tractor according to an embodiment of the present invention; [Figure 2] FIG. 1 is a left side view of a tractor according to another embodiment of the present invention. [Figure 3] FIG. 1 is a partial front view of a tractor according to an embodiment of the present invention; [Figure 4] FIG. 10 is a partial front view of a tractor according to another embodiment of the present invention. [Figure 5] 1 is a plan view of a tractor according to another embodiment of the present invention; [Figure 6] (a) A partial perspective view (part 1) of a tractor according to an embodiment of the present invention, (b) A partial perspective view (part 2) of a tractor according to an embodiment of the present invention, and (c) A partial perspective view (part 3) of a tractor according to an embodiment of the present invention. [Figure 7](a) An explanatory diagram (part 1) of the turning control of a tractor according to an embodiment of the present invention, (b) An explanatory diagram (part 2) of the turning control of a tractor according to an embodiment of the present invention, (c) An explanatory diagram (part 3) of the turning control of a tractor according to an embodiment of the present invention, (d) An explanatory diagram (part 4) of the turning control of a tractor according to an embodiment of the present invention, (e) An explanatory diagram (part 5) of the turning control of a tractor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

[0024] Similarly, some components may not be shown in the drawings, or may be shown in perspective or in simplified form.

[0025] While explaining the operation of the tractor according to the embodiment of the present invention, a work vehicle operation control method according to an invention related to the present invention, which is realized by the controller 10 and the like, will also be explained.

[0026] Such a tractor is a specific example of a work vehicle according to the present invention.

[0027] (1) First, the configuration and operation of a tractor according to an embodiment of the present invention will be specifically described with reference to mainly FIGS. 1 to 5.

[0028] Here, Figure 1 is a left side view of a tractor according to an embodiment of the present invention, Figure 2 is a left side view of a tractor according to another embodiment of the present invention, Figure 3 is a partial front view of a tractor according to an embodiment of the present invention, Figure 4 is a partial front view of a tractor according to another embodiment of the present invention, and Figure 5 is a plan view of a tractor according to another embodiment of the present invention.

[0029] The tractor according to an embodiment of the present invention is equipped with a rotary encoder that uses a steering wheel rotation angle sensor that detects the steering wheel rotation angle, which is the angle of the steering wheel 40 as the number of steering wheel rotations, and the steering angle control as the control of the wheel steering angle of the steered wheels 501 is performed by an actuator in accordance with the detection value of the steering wheel rotation angle sensor.

[0030] As shown in Figure 1, a steering wheel 40, a forward / reverse lever 102, a clutch pedal 103, etc. are provided near a dashboard cover 101 in front of a seat 104. The inclination of the vehicle body 100 in the left-right direction is measured by an inclination sensor 105. The work implement 113 is a rotary tiller equipped with a tilling depth sensor 111 and a rotating cover 112, etc. The work implement 113 is connected to the tractor by a top link 108 and a lower link 109, and the work implement is raised and lowered by a main cylinder 110 via a lift arm 107, with the lift arm sensor 106 detecting the raised and lowered state of the work implement.

[0031] As shown in FIG. 2, the work implement 113 may not be a rotary tiller, but may be a fertilizer spreader also known as a broadcaster.

[0032] As shown in Figure 3, the tractor position and other information are measured by a communication unit 202 connected to an external GPS (Global Positioning System) unit 201. Turning operations are performed using a steering cylinder 304 driven by a steering solenoid 203, and are controlled by a travel control unit 205 of the controller 10 based on the wheel steering angle detected by a wheel steering angle sensor 204, also known as a turning angle sensor.

[0033] As shown in FIG. 4, the turning operation may be performed using an automatic steering motor 301 and a steering cylinder 304 driven by a steering hydraulic unit 302 that supplies hydraulic oil according to the direction and amount of rotation via an oil passage 303.

[0034] As shown in FIG. 5, in a farm field in which a headland area 401 and a work area 402 are formed, work is carried out by the work implement 113 while the vehicle body 100 repeatedly moves forward in a straight line and turns.

[0035] (2) Next, the configuration and operation of the tractor according to the embodiment of the present invention will be described in more detail, mainly with reference to FIGS. 6(a) to 6(c) and 7(a) to 7(e).

[0036] Here, Figures 6(a) to 6(c) are partial perspective views (parts 1 to 3) of a tractor according to an embodiment of the present invention, and Figures 7(a) to 7(e) are explanatory diagrams (parts 1 to 5) of the turning control of a tractor according to an embodiment of the present invention.

[0037] When the work mode is selected by the work mode selection unit 20 and an instruction to start turning is given by the turning instruction unit 30, the controller 10 starts turning control to match the wheel steering angle with a predetermined turning wheel steering angle.

[0038] As shown in Figures 6(a) and 6(b), in this embodiment, the work mode selection value of the work mode selection unit 20, which is like a dial for switching modes, is selected from "work" which means tilling work, and "non-work."

[0039] When the work mode selection value of the work mode selection unit 20 is "work," steering angle control is performed so that the wheel steering angle of the steering wheel 501 on the same side as the turning operation side instructed by the turning instruction unit 30 is made to match the so-called full-lock turning wheel steering angle.

[0040] The turning instruction unit 30 is a blinker switch.

[0041] In this embodiment, by utilizing an existing member such as a turn signal lever as a turn signal switch for multiple purposes, a dedicated member as the turning instruction unit 30 is not required, which promotes a reduction in the number of parts.

[0042] The turn instruction unit 30 issues an instruction to turn left, turn right, or turn off.

[0043] When the work mode is selected by the work mode selection unit 20, an instruction to turn left or right is given by the turning instruction unit 30, and then an instruction to turn off is given by the turning instruction unit 30, the controller 10 ends the turning control and performs straight-ahead wheel steering angle recovery control to match the wheel steering angle with the straight-ahead wheel steering angle.

[0044] That is, in a configuration in which the above-described steering angle control is performed, when an instruction that is neither a left turn instruction nor a right turn instruction, such as an instruction to switch off the turn signal, is given by the turn instruction unit 30, the wheel steering angle is returned to the straight-ahead wheel steering angle.

[0045] When the work mode is selected by the work mode selection unit 20, and either a left turn or a right turn is commanded by the turn command unit 30, the controller 10 performs steering wheel angle cancellation control to ignore changes in the angle of the steering wheel 40, and then, when a turn-off command is given by the turn command unit 30, the controller 10 completes the straight-ahead wheel steering angle recovery control to match the angle of the steering wheel 40 with the straight-ahead steering wheel angle, and then releases the steering wheel angle cancellation control.

[0046] In this embodiment, by performing the steering wheel angle cancellation control, not only does the operator not need to worry about adverse effects on the turning operation caused by inappropriate operation of the steering wheel 40, but the turning operation is completed with the angle of the steering wheel 40 reliably matching the straight-ahead steering wheel angle. Therefore, manual operation, which often requires considerable experience when turning, is not required, and the burden on the operator can be reduced.

[0047] When the work mode is selected by the work mode selection unit 20, when either a left turn or a right turn is commanded by the turning command unit 30, the controller 10 performs steering wheel angle lock control to fix the angle of the steering wheel 40 at the straight-ahead steering wheel angle, and then when a turn-off command is given by the turning command unit 30, the controller 10 completes the straight-ahead wheel steering angle recovery control and then releases the steering wheel angle lock control.

[0048] In this embodiment, the steering wheel angle lock control not only eliminates the need for the operator to worry about adverse effects on the turning operation caused by inappropriate operation of the steering wheel 40, but also ensures that the turning operation is completed with the angle of the steering wheel 40 reliably aligned with the straight-ahead steering wheel angle. Therefore, manual operation, which often requires considerable experience, is not required when turning, thereby improving reliability.

[0049] The time period after the turning control is initiated until the wheel steering angle matches the predetermined turning wheel steering angle is adjustable.

[0050] As shown in Figures 6(a) and 6(c) and 7(a) through 7(e), in such an embodiment, the time it takes for the road wheel steering angle to match the turning wheel steering angle is variably adjusted based on the adjustment of the steepness or steepness of the turn control slope in response to the dial position of the steering angle speed adjuster 502.

[0051] (3) Next, the configuration and operation of the tractor according to the embodiment of the present invention will be described in more detail, mainly with reference to FIGS.

[0052] Even if a steering wheel rotation speed smaller than the normal turning steering wheel rotation speed when driving on the road, the steering help function, which assumes steering angle control at the normal turning steering wheel rotation speed, can be used when the work mode selection value of the work mode selection unit 20 is "work."

[0053] In a configuration in which such steering angle control is performed, the condition under which a steering wheel rotation speed smaller than the normal turning steering wheel rotation speed is regarded as the normal turning steering wheel rotation speed can be set using a dial or the like, and for example, the full-lock assumed steering angle ratio for providing a steering wheel rotation speed at which full-lock steering angle control is assumed can be freely set.

[0054] When the inclination of the vehicle body 100 in the left-right direction exceeds a predetermined level, the steering help function is automatically turned off.

[0055] Furthermore, the height of the attached work implement is monitored, and a steering help function cancel switch or the like is provided to cancel the steering help function when the height of the work implement is lower than a predetermined height. This is because if the steering angle control is performed at a large wheel steering angle even when the work implement is lowered, work implement trouble is likely to occur.

[0056] When the left and right brake pedals are disconnected, the vehicle is not traveling on the road but is engaged in plowing, so the steering help function is automatically turned on.

[0057] Therefore, in such a case, when only one brake pedal is depressed in a so-called one-sided braking operation, steering angle control is performed using the steering help function.

[0058] When only one brake pedal is depressed, steering wheel operations that instruct steering toward the opposite side to the brake pedal are ignored. By ignoring steering wheel operations in this way, problems caused by incorrect operation are reduced.

[0059] For tractor models equipped with a mechanism in which the brake application force is controlled by an actuator in accordance with the amount of brake pedal depression, it is desirable, from the standpoint of safety etc., that when only one brake pedal is depressed, any steering wheel operation that commands steering towards the side opposite the side on which the brake pedal is depressed be ignored.

[0060] For example, when a conflict occurs between left and right brake pedal operation and steering wheel operation, a switch may be provided to select the operation that will be used preferentially, and operations not selected by the switch may be ignored.

[0061] When the distance from the ridge to the tractor, measured by GPS or other devices, is within D meters, and the angle of the tractor's central axis relative to the ridge line is within ±θ degrees from 90 degrees, steering angle control is performed using the steering help function. The values ​​of D and θ can be set using a dial or other device.

[0062] For example, the distance from the ridge of the field to the tractor and the angle of the tractor's central axis in the direction of travel relative to the ridge line are monitored by a camera.

[0063] The steering angle speed adjuster 502 can be used as a mode switch dial for binary or continuous selection of a steering mode to realize a user-friendly function such as a "gentle steering mode." Whether the tractor is located in a field is determined by using a so-called work switch or GPS, and when the user-friendly function is turned on and it is determined that the tractor is located in a field, the wheel steering speed, also called the steering wheel turning angular speed, to which the steering wheel rotation speed is assigned is reduced compared to the assignment according to the normal assignment relationship. By changing the assignment relationship between the steering wheel rotation speed and the wheel steering speed to be gentle in this way, specifications that are often considered to be friendly to elderly people are realized.

[0064] That is, when the steering mode selection value is "zero" or "off," the steering wheel rotation speed is assigned to the wheel steering speed in the normal assignment relationship, and when the steering mode selection value is "non-zero" or "on," the steering wheel rotation speed is assigned to the wheel steering speed in the assignment relationship according to the dial position of the steering angle speed adjuster 502.

[0065] For example, when the steering mode selection value is "non-zero" or "on," and the tractor is determined to be located in a field, the steering wheel rotation speed is assigned to the wheel steering speed in a gradual assignment relationship according to the dial position of the steering angle speed adjuster 502.

[0066] When the steering mode selection value is "non-zero" or "on," when it is determined that the tractor is located in a field, the turning wheel steering angle, which is the target steering wheel angle to which the final target turning steering wheel rotation speed is assigned, is increased, but it is often desirable to increase the time until the wheel steering angle matches the turning wheel steering angle by gradually decreasing the wheel steering speed, which is the steering speed until the turning wheel steering angle is reached.

[0067] Such an allocation relationship for reducing wheel steering speed can be set by a dial or the like.

[0068] When the steering mode selection value is "non-zero" or "on", and it is determined that the tractor is located in a field, steering angle control is performed using the steering help function described above, which not only reduces the steering wheel rotation speed at which full-lock steering angle control is assumed, but also, when the steering wheel rotation speed reaches the rotation speed corresponding to the full-lock turning wheel steering angle, after gentle steering, the wheel steering speed gradually increases, and as the steering wheel returns to the center position, it is often desirable that the steering wheels 501 are gently returned to the center position.

[0069] When the steering mode selection value is "non-zero" or "on," and it is determined that the tractor is located in a field, it is also possible to consider an embodiment in which the rate of change of the tractor's traveling direction center axis angle can be adjusted according to the dial position of the steering angle speed adjuster 502, etc., based on the above-mentioned allocation relationship for allocating the steering wheel rotation speed to the wheel steering speed and the left and right brake pedal operation.

[0070] When the work mode selection value of the work mode selection unit 20 is "Work," the inclination of the vehicle body 100 in the lateral direction is monitored, and under conditions where it is determined that the inclination exceeds a predetermined level, if a steering operation is performed toward an upward tilt that increases the inclination angle, the turning wheel steering angle is increased. This is expected to correct the vehicle body descent toward a downward tilt, which is likely to occur when working on a slope.

[0071] When the work mode selection value of the work mode selection unit 20 is "work," the so-called field conditions are monitored using camera images or slip ratio measurements, and if a steering operation is performed under conditions in which the work field is determined to be a wet paddy field, the turning wheel steering angle is increased. This is expected to correct the so-called steering time lag that is likely to occur due to wheel slippage when working in wet paddy fields.

[0072] The program of the invention related to the present invention is a program for causing a computer to execute all or part of the steps (or processes, operations and actions, etc.) of the work vehicle operation control method of the invention related to the present invention described above, and is a program that operates in cooperation with a computer.

[0073] Furthermore, the recording medium of the invention related to the present invention is a recording medium on which a program is recorded for causing a computer to execute all or some of the operations of all or some of the steps (or processes, operations and actions, etc.) of the work vehicle operation control method of the invention related to the present invention described above, and is a computer-readable recording medium in which the read program is used in cooperation with a computer.

[0074] It should be noted that the above-mentioned "some steps (or processes, operations, actions, etc.)" means one or some steps among the plurality of steps.

[0075] Furthermore, the above-mentioned "operations of steps (or processes, operations, actions, etc.)" means the operations of all or part of the above-mentioned steps.

[0076] Furthermore, one mode of use of the inventive program related to the present invention may be in the form of being transmitted through a transmission medium such as the Internet, light, radio waves, or sound waves, being read by a computer, and operating in cooperation with the computer.

[0077] The recording medium also includes a ROM (Read Only Memory).

[0078] Furthermore, a computer is not limited to pure hardware such as a CPU (Central Processing Unit), and may also include firmware, an OS (Operating System), and even peripheral devices.

[0079] As described above, the configuration of the present invention may be realized in software or hardware. [Industrial Applicability]

[0080] The work vehicle of the present invention can improve usability and is useful for use as a work vehicle such as a tractor. [Explanation of symbols]

[0081] 10 Controllers 20 Work mode selection section 30 Turn indicator 40 Steering Wheel 100 body 101 Dashboard Cover 102 Forward / reverse lever 103 Clutch pedal 104 seats 105 Tilt sensor 106 Lift arm sensor 107 Lift arm 108 Top Link 109 Lower Link 110 Main cylinder 111 tillage depth sensor 112 Rotating cover 113 Work equipment 201 External GPS unit 202 Communication Unit 203 Steering solenoid 204 Wheel steering angle sensor 205 Travel control unit 301 Automatic Steering Motor 302 Steering hydraulic unit 303 Oil road 304 Steering cylinder 401 Headland area 402 Work area 501 Steering wheel 502 Steering angle speed adjuster

Claims

1. a work mode selection unit that selects at least a work mode; a turn instruction unit that issues an instruction to start at least a turn; a controller that starts turning control to make a wheel steering angle coincident with a predetermined turning wheel steering angle when the turning instruction unit issues the instruction to start the turning operation in a case where the work mode is selected by the work mode selection unit; A work vehicle characterized by comprising:

2. 2. The work vehicle according to claim 1, wherein the turn instruction unit is a switch that issues the instruction to turn at least one of left and right.

3. the turning instruction unit is a switch that issues the instruction to turn left, turn right, or turn off, 3. The work vehicle according to claim 2, wherein, when the work mode is selected by the work mode selection unit, the instruction for either the left turn or the right turn is given by the turning instruction unit, and then the instruction for turning off is given by the turning instruction unit, the controller terminates the turning control and performs straight-ahead wheel steering angle recovery control to match the wheel steering angle with the straight-ahead wheel steering angle.

4. It also has a steering wheel, 4. The work vehicle according to claim 3, wherein, when the work mode is selected by the work mode selection unit, when the instruction for either the left turn or the right turn is given by the turning instruction unit, the controller performs steering wheel angle cancellation control to ignore changes in the angle of the steering wheel, and thereafter, when the instruction for turning off is given by the turning instruction unit, the controller completes the straight-ahead wheel steering angle recovery control to make the angle of the steering wheel coincide with the straight-ahead steering wheel angle, and then releases the steering wheel angle cancellation control.

5. It also has a steering wheel, 4. The work vehicle according to claim 3, wherein, when the work mode is selected by the work mode selection unit, when the instruction for either the left turn or the right turn is given by the turning instruction unit, the controller performs steering wheel angle lock control to fix the angle of the steering wheel at a straight-ahead steering wheel angle, and thereafter, when the instruction for turning off is given by the turning instruction unit, the controller completes the straight-ahead wheel steering angle recovery control and then releases the steering wheel angle lock control.

6. 6. The work vehicle according to claim 4, wherein the time until the wheel steering angle is made to coincide with the predetermined turning wheel steering angle after the turning control is started is adjustable.

7. 7. The work vehicle according to claim 6, wherein the turning instruction unit is a blinker switch.

Images