Ride-type rice transplanter

Abstract

To provide a sulky rice transplanter capable of solving problems that operation of a handle during turning is complicated, there is no composure for correctly aligning a center position of a machine body to a work path line, and it is difficult for an operator to apply to lowering operation of a planting implement and planting drive turn-in operation.SOLUTION: A control part comprises mode switching means for switching a control mode of a travel steering unit between a small turn turning mode for independently steering each wheel so that the wheel is orthogonal to a line connecting a machine body turning center which is separated from a planting position on an innermost side in a turning direction by a distance almost equal to a half of a distance between planting rows and a drive rotation center of each wheel, in plan view, by a prescribed or greater amount of operation of a steering operation tool, and independently driving the wheels so as to make a peripheral speed ratio of the respective wheels equal to a plane distance ratio of drive rotation centers of the respective wheels, and an arbitrary turning mode for, in proportion to an operation amount of the steering operation tool, directing the respective wheels to tangential directions of circles where the same one point is a turning center, by steering, and independently driving the wheels so as to set the peripheral speed ratio of the respective wheels to be equal to a ratio of the plane distance between the same one point and the drive rotation center of the respective wheels.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a riding rice transplanter that controls the steering angle and travel drive of four wheels. [Background technology]

[0002] A riding rice transplanter is known in the past that has front and rear wheels mounted so as to be steerable by separate actuators, and is provided with a steering angle adjustment means consisting of a sensor that detects the steering angle of the steering handle and a controller that automatically operates the actuator based on information from the sensor (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-206574 Summary of the Invention [Problem to be solved by the invention]

[0004] In the riding rice transplanter shown in Patent Document 1 mentioned above, the steering angle adjustment means automatically adjusts the steering angle of the front and rear wheels in accordance with the operating angle of the steering handle, with the center of rotation being a point to the outside of the inner end working position of the paddy field working device, a distance approximately half the working row spacing of the paddy field working device.As a result, operating the steering handle while turning is cumbersome, and there is no time to accurately align the center of the riding rice transplanter on the working path line, or to concentrate on lowering the planting machine and driving it in for planting, which is inconvenient.

[0005] In addition, in the past, when changing direction at the four corners of a field, the riding rice transplanter had to move back and forth over the same spot multiple times, which caused problems such as roughening the field surface and the plow bed.

[0006] Furthermore, in a curved field, when the riding rice transplanter moves from the curved planting path to a straight planting path, there is a risk that the rows of planted seedlings will meander.

[0007] Furthermore, in the past, when the left and right wheels were steered, if they were not steered to the same angle, the treads of the left and right wheels would change. Furthermore, there was a limit to the steering angle of the wheels, which limited the turning and driving methods. [Means for solving the problem]

[0008] In a riding rice transplanter in which a planting implement is connected to the rear of a traveling body having left and right front wheels and rear wheels, a traveling steering device is provided that drives and steers each of the left and right front wheels and rear wheels independently, and the traveling steering device is operated via a control unit by operating a steering operation tool, the control unit changes the control mode of the traveling steering device to a mode that is perpendicular to a line connecting the turning center of the machine body, which is approximately half the distance between rows from the innermost planting position in the turning direction in a plan view, and the driving rotation center of each wheel, by operating the steering operation tool by a predetermined or more degree. and an arbitrary turning mode in which, in proportion to the amount of operation of the steering operating tool, each of the wheels is steered so as to face a tangent to a circle whose turning center is the same point, and each wheel is independently driven so that the peripheral speed ratio of each wheel is the same as the ratio of the planar distance between the turning center and the drive rotation center of each wheel.

[0009] A second feature of the mode switching means is that it can switch the control mode of the traveling steering device to an in-place rotation mode in which, by operating the steering operating tool to a predetermined level or more, each wheel is independently steered so that it is perpendicular to a line connecting the center of rotation of the vehicle body, which is located on the left-right center line of the vehicle body in a plan view, and the drive rotation center of each wheel, and each wheel is independently driven so that the peripheral speed ratio of each wheel is the same as the ratio of the planar distances between the center of rotation of the vehicle body and the drive rotation center of each wheel.

[0010] A third feature of the present invention is that the mode switching means can switch the control mode of the travel steering device to a diagonal steering mode in which each of the wheels is steered by the same amount in the same direction in proportion to the amount of operation of the steering operating tool, and is driven so that the peripheral speed ratio of each wheel is the same.

[0011] The fourth feature is that the axle cases that support each of the wheels are configured to be rotatable relative to the vehicle body via vertical pivot shafts, and in a plan view, the intersection of the lateral center lines of the wheel's contact area and the axis of the axle coincides with the pivot shaft. [Effects of the Invention]

[0012] According to the invention of claim 1, a driving and steering device is provided that drives and steers each wheel independently, and by operating the driving and steering device via the control unit by operating the steering operating tool, it becomes possible to freely control the rotation direction, rotation speed, steering direction and steering angle of the left and right front and rear wheels, and the driving and steering device can be switched between multiple modes.

[0013] In addition, the device is provided with a mode switching means that can switch between a tight turn mode and an arbitrary turn mode, and by selecting the tight turn mode, it is easy to operate the steering operation tool while turning, allowing the operator to concentrate on the work of accurately aligning the center of the riding rice transplanter on the work route line, lowering the planting machine, and turning on the planting drive.

[0014] According to the invention of claim 2, by providing the mode switching means of claim 1 with an on-the-spot rotation mode, it is possible to change direction in a narrower range than any other turning mode in places where the turning range is narrow, such as the four corners of a field. This eliminates the need for the riding rice transplanter to move back and forth when changing direction at the four corners of a field, as is the case with conventional riding rice transplanters, thereby shortening working time and minimizing the extent of disturbance to the field.

[0015] According to the invention of claim 3, by providing the mode switching means of claim 1 or claim 2 with a diagonal traveling mode, when the riding rice transplanter is switched from straight traveling to diagonal traveling or from diagonal traveling to straight traveling in a curved field, the diagonal traveling mode can be switched from straight traveling to diagonal traveling without changing the direction of the riding rice transplanter, and the planting machine can be accurately aligned next to a curved row or a straight row after planting has been completed.

[0016] Furthermore, in a curved field, when the riding rice transplanter moves from a curved planting path to a straight planting path, there is no risk of the rows of planted seedlings meandering.

[0017] Furthermore, by providing the diagonal traveling mode in the mode switching means of claim 2, the turning mode, rotation mode, and traveling mode can be selectively used depending on the field conditions, the place to turn, and the operator's specifications.

[0018] According to the invention of claim 4, the axle cases that support each wheel (wheel) are configured to be rotatable relative to the body via vertical pivot shafts, and in a plan view, the intersection of the left and right center lines of the wheel's contact area and the axis of the axle is configured to coincide with the pivot shaft.As a result, when the wheels are steered, the wheel's contact position does not change, and the treads of the left and right wheels do not change even when the wheels are steered 360 degrees, so the area of ​​the field that is roughened can be reduced, and the wheels can travel between the rows, which is a unique feature of rice transplanters. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is an overall side view of a riding rice transplanter according to the present invention. [Figure 2] FIG. 1 is a power transmission diagram of a riding rice transplanter according to the present invention. [Figure 3] 1A and 1B are a front view and a plan view showing a travel steering device for a riding rice transplanter according to the present invention. [Figure 4] FIG. 10 is a front view showing another power transmission method of the traveling steering device of the riding rice transplanter according to the present invention. [Figure 5]FIG. 2 is an explanatory diagram showing the planting process and the turning process of the riding rice transplanter according to the embodiment. [Figure 6] FIG. 2 is a plan view showing the operation amount of the steering operation tool according to the embodiment. [Figure 7] 1A and 1B are explanatory diagrams illustrating the operation of the riding rice transplanter according to the embodiment, showing (a) a tight turning mode and (b) an arbitrary turning mode. [Figure 8] 1A and 1B are explanatory views showing the operation of the riding rice transplanter according to the embodiment, showing (a) on-the-spot turning mode A and (b) oblique traveling mode. [Figure 9] 1A and 1B are explanatory diagrams illustrating the operation of the riding rice transplanter according to the embodiment in (a) on-the-spot turning mode B, (b) pivot turning mode, and (c) left-right traveling mode. [Figure 10] FIG. 1 is a control block diagram showing a riding rice transplanter of the present invention. [Figure 11] FIG. 1 is a plan view showing a mode switching device for a riding rice transplanter of the present invention. [Figure 12] FIG. 1 is a flowchart of the main control of the riding rice transplanter of the present invention. [Figure 13] FIG. 2 is a flowchart showing (a) the travel mode selection control and (b) the turning mode selection control of the riding rice transplanter of the present invention. [Figure 14] FIG. 1 is a flowchart showing steering control of the riding rice transplanter of the present invention. [Figure 15] FIG. 1 is a flowchart showing the operation control of the work machine of the riding rice transplanter of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is an overall side view of a riding rice transplanter 1 according to the present invention. As shown in Fig. 1, reference numeral 2 denotes a traveling body of the riding rice transplanter 1, which is a transplanter. The traveling body 2 is supported by left and right front wheels 4, 5 and rear wheels 6, 7. A center marker 8 is provided at the center of the front end of the traveling body 1, and a hood 9 is erected behind it. Above this, an operation panel 10 and a steering operation device (steering handle) 11 are provided. Below this, a machine travel stop pedal 12 is provided. Below this, a step surface 13 forming the floor of the operation section is provided, and above this, a driver's seat 14 is provided.

[0021] In addition, a link mechanism 15 is supported at the rear of the traveling body 2 so that it can be raised and lowered freely, and a single-acting hydraulic cylinder 16 is provided to drive the link mechanism 15 up and down, and a planting machine 3 is connected to the rear of the link mechanism 15.

[0022] An auxiliary speed change lever 17 is provided on the right side of the steering operation tool 11, and a main speed change lever 18 is provided on the left side.

[0023] The main speed change lever 18 has a forward position at the front side of the main speed change lever guide, a neutral position approximately in the center, and a reverse position at the rear side, with a travel drive stop position at the neutral position, and acceleration / deceleration ranges between the forward position and the neutral position, and between the neutral position and the reverse position, and the main speed change lever 18 is configured to be operable between the forward position and the reverse position on either side of the neutral position, and a position detection potentiometer 20 is provided at the base end of the main speed change lever 18 for detecting the forward position, neutral position, and reverse position.

[0024] The sub-speed change lever 17 has a driving speed position for high speed travel suitable for movement on the road at the front side of the sub-speed change lever guide, a neutral position (where the wheels are stopped) at approximately the center, and a working speed position for low speed travel suitable for planting seedlings at the rear side, and is configured to be operable to the driving speed position and the working speed position on either side of the neutral position, and the base end of the sub-speed change lever 17 is equipped with a position detection potentiometer 19 that detects the driving speed position, neutral position and working speed position.

[0025] To explain the planting work machine 3 in more detail, it has a seedling carrying table 21 tilted forward and a planting device 22 below the seedling carrying table 21 for planting the seedlings, and a float 23 below the planting device 22 for leveling the surface of the planting field, but all of these basic configurations are conventional.

[0026] Next, an embodiment of the riding rice transplanter 1 of the present invention will be described. As shown in Figures 2 to 4 and 10, Figure 2 is a power transmission diagram of the riding rice transplanter according to the present invention, Figure 3 is (a) a front view and (b) a plan view showing the travel steering device of the riding rice transplanter according to the present invention, Figure 4 is a front view showing another power transmission method of the travel steering device of the riding rice transplanter according to the present invention, and Figure 10 is a control block diagram of the riding rice transplanter. The power transmission diagram is a diagram of a power generating device 24 having an engine 25, generators 26, 26, 26, a regulator 27, and a storage battery (battery) 28, a control device (microcomputer) 29, motor drivers 31a, 31b, 31c, 31d for travel drive motors, motor drivers 31e, 31f, 31g, 31h for steering drive motors, travel drive motors 32a, 32b, 32c, 32d, steering drive motors 33a, 33b, 33c, 33d, pivot shafts 34, 34, 34, 34, axles The system is composed of a wheel case 50, steering angle detection sensors 35a, 35b, 35c, 35d for the left and right front wheels 4, 5 and the left and right rear wheels 6, 7, rotation speed detection sensors 36a, 36b, 36c, 36d for the left and right front wheels 4, 5 and the left and right rear wheels 6, 7, power transmission systems 48, 48, 48, 48, and each of the travel steering devices 30 that drive the left and right front wheels 4, 5 and the rear wheels 6, 7, and a planting drive device 37 having a planting drive motor 38 and a motor driver 39 that drives the planting device 22 of the planting work machine 3.

[0027] The control device (microcomputer) 29 will now be described in detail. The microcomputer 29 inputs (INPUT) detection data from the multiple detection switches, sensors, potentiometers, and motor drivers of the riding rice transplanter 1 to the microcomputer 29, controls them using the microcomputer 29, and outputs (OUTPUT) operation data from the microcomputer 29 to the power generating device 24, the traveling steering devices 30, 30, 30, 30, and the planting drive device 37.

[0028] The power generating device 24 will now be described in detail. The power generating device 24 is composed of an engine 25, a plurality of generators 26, 26, 26, a regulator 27, and a storage battery 28, and is configured such that the driving force produced by the engine 25 is used to generate electricity by the plurality of generators 26, 26, 26, and the voltage is kept constant by the regulator 27, and the electricity is charged into the storage battery 28.

[0029] The travel steering device 30 will be described in detail. The travel steering device 30 includes motor drivers 31a, 31b, 31c, and 31d for travel drive motors 32a, 32b, 32c, and 32d, motor drivers 31e, 31f, 31g, and 31h for steering drive motors 33a, 33b, 33c, and 33d, travel drive motors 32a, 32b, 32c, and 32d, steering drive motors 33a, 33b, 33c, and 33d, and left and right front wheels 4 and 5. and steering angle detection sensors 35a, 35b, 35c, 35d for the left and right rear wheels 6, 7 (each wheel 53), brake devices 40..., pivot shafts 34, 34, 34, 34, drive shafts 43a, 43a, 43a, 43a, drive shafts 43b, 43b, 43b, 43b, steering gears 44..., drive cases 42, 42, 42, 42, and drive devices 41, 41, 41, 41 having drive cases 42, 42, 42, 42, and each of the wheels. A power transmission system 48, 48, 48, 48, consisting of axles 47, 47, 47, 47, axle cases 50, 50, 50, 50, and axle cases 51, 51, 51, 51. and each wheel 53 having elastic wheels (tires) 53e, 53e, 53e, 53e each having boss portions 53a, 53a, 53a, 53a, pins 53b, 53b, 53b, 53b, spokes 53c, reinforcing plates 53h, 53h, 53h, 53h, rim portions 53d, 53d, 53d, 53d, blade lugs 53f, and running lugs 53g.

[0030] Furthermore, as shown in the power transmission diagram of Figure 2, the front view of the traveling steering device of Figure 3(a), the plan view of the traveling steering device of Figure 3(b), and the front view of Figure 4 showing another power transmission method of the traveling steering device, the axle cases 50, 50, 50, 50 that support each of the wheels 53... are configured to be rotatable relative to the vehicle body via vertical pivot shafts 34, 34, 34, 34, and in a plan view, the intersection of the left and right center lines of the ground contact portions 71 of the wheels 53, 53, 53, 53 and the axis lines of the axles 47, 47, 47, 47 coincides with the axis lines of the pivot shafts 34, 34, 34, 34.

[0031] The ground contact portion 71 is the portion of the outer peripheral surface of the elastic wheels (tires) 53e, 53e, 53e, 53e that comes into contact with the tillage bed of the field, and the blade lugs 53f..., whose size and protruding direction vary depending on the type of wheel 53, are not included in the outer peripheral surface of the elastic wheels 53e, 53e, 53e, 53e.

[0032] As shown in Figures 3 and 4, the aforementioned rotating support shafts 34, 34, 34, 34 may be configured such that drive shafts 43a, 43a, 43a, 43a of the travel drive motors 32a, 32b, 32c, 32d are used as the rotating support shafts 34, 34, 34, 34, or such that power is transmitted from the drive shafts 43a, 43a, 43a, 43a of the travel drive motors 32a, 32b, 32c, 32d to the rotating support shafts 34, 34, 34, 34 via a plurality of gears 45...

[0033] A detailed description will be given of the drive device 41. The drive device 41 has the traveling drive motors 32a, 32b, 32c, and 32d and the steering drive motors 33a, 33b, 33c, and 33d arranged side by side in a drive case 42, and operates the rotational drive and drive stop of the traveling drive motors 32a, 32b, 32c, and 32d and the steering drive motors 33a, 33b, 33c, and 33d via motor drivers 31a, 31b, 31c, and 31d for the traveling drive motors and motor drivers 31e, 31f, 31g, and 31h for the steering drive motors, using power supplied from the storage battery 28 and control data from the microcomputer 29.

[0034] Further, holes 54a, 54b are provided in the bottom surface of the drive case 42 to allow the tip ends of the drive shaft (rotating support shaft 34) 43a of the traveling drive motor 32 and the drive shaft 43b of the steering drive motor 33 to rotatably protrude outward from the bottom of the drive case 42, and the tip ends of the drive shafts 43a, 43b of the traveling drive motor 32 and the steering drive motor 33 are passed through the holes 54a, 54b, and the tip end of the drive shaft 43a (rotating support shaft 34) of the traveling drive motor 32 is rotatably passed through a hole 55 in the top surface of the axle case 50 described below and is connected to a gear 45 of a power transmission system 48 inside the axle case 50. A steering gear 44 for steering is attached to the tip end of the drive shaft 43b of the steering drive motor 33.

[0035] The transmission device 52 will now be described in detail. As shown in Figure 3, the shape and structure of the axle case 50 of the transmission device 52 is formed in an upside-down L shape so as to bypass one of the upper left and right sides of the wheels 53, and a steering gear 49 for steering is provided on the outer side of the upper part of the axle case 50, and the steering gear 44 and the steering gear 49 are configured to mesh together, so that the steering gear 44 is rotationally driven by the driving of the steering drive motor 33, and the rotational drive rotates the steering gear 49, thereby rotating the axle case 50 and enabling the wheels 52 to be steered.

[0036] The internal structure of the axle case 50 is configured such that a power transmission system 48 consisting of a plurality of gears 45 that transmit the driving force of the traveling drive motor 32 and a transmission shaft 46 is arranged from the top to the bottom of the axle case 50, and the base end of an axle 47 for rotating a wheel 53 is connected to the downstream gear 45 of the power transmission system 48, and the axle 47 protrudes outward from the axle case 50 at the bottom of the axle case 50, and the wheel 53 is attached to a predetermined position on the axle 47.

[0037] The tip end of the axle 47 is attached to the upper side of the axle case 50 by attaching the upper side of a support member 51, and the tip end of the axle 47 is rotatably supported and fixed to the lower part of the support member 51.

[0038] In addition, the clutch and brake device 40 on the traveling drive motor 32 side may be provided on the traveling drive motor 32 side or in the power transmission system 48 inside the axle case 50, and the clutch and brake device 40 on the steering drive motor 33 side may be provided on the steering drive motor 33 side or between the steering drive motor 33 and the steering gear 44.

[0039] In plan view, the center of the rotation support shaft 34 (drive shaft 43a of the traveling drive motor 32) and the center of the steering gear 49 are arranged so as to coincide with each other.

[0040] The shape and structure of the axle case 50 of the transmission device 52 is formed in a bifurcated U-shape when viewed from the front so as to bypass both the upper left and right sides of the wheels (each wheel 53), and a steering gear 49 for steering is provided on the outer side of the upper part of the axle case 50, and the steering gear 44 and the steering gear 49 are configured to mesh with each other. The internal structure of the axle case 50 is configured so that a plurality of gears that transmit the driving force of the traveling drive motors 32a, 32b, 32c, and 32d extend from the top to the bottom of the axle case 50. A power transmission system 48 consisting of gears 45... and transmission shafts 46... is arranged, and the power transmission system 48 is branched into two left and right branches at the center of the upper left and right of the axle case 50, and the multiple gears 45 and transmission shafts 46 are connected to the power transmission system 48 toward the lower part of the axle case 50, and a reverse rotation mechanism that reverses the transmission direction is provided on either the left or right side of the power transmission system 48, and the left and right ends of an axle 47 that rotates and drives the wheels are connected to the gears 45 downstream of the power transmission system 48 on the left and right sides at the lower left and right sides of the axle case 50.

[0041] The axle 47 may be configured to have a wheel integrally connected to it at a predetermined position on the axle 47, or to have a wheel that can be detachably separated and connected to it.

[0042] The wheel 53 will now be described in detail. As shown in Figures 1, 3, and 4, the wheel 53 has a boss 53a in the center for mounting the axle 47. The base ends of spokes 53c are arranged at equal intervals on the outer periphery of this boss 53a (three spokes 53c are arranged at equal intervals in this embodiment), the outer periphery of the boss 53a and the base ends of the spokes 53c are fixed by welding, and the tip ends of the spokes 53c are fixed by welding to the inner periphery of an annular rim 53d, and the outer periphery of the rim 53d is covered with an elastic material such as rubber, forming the elastic ring 53e.

[0043] In addition, the outer periphery of the boss portion 53a and the spokes 53c are firmly connected by welding and securing a round or triangular reinforcing plate 53h, and the wheel 53 is prevented from coming off the axle 47 by fitting the axle 47 into the boss portion 53a and inserting mounting pins 53b, 53b from the outer periphery of the boss portion 53a to the axle 47.

[0044] The basic configuration of the lugs (blade lugs 53f, running lugs 53g) of the elastic ring body is the same as that of the conventional ones, and detailed description thereof will be omitted.

[0045] Next, the travel mode and turning mode of the riding rice transplanter 1 according to the embodiment of the present invention will be described with reference to Figures 5 to 9. Figure 5 is an explanatory diagram showing the planting process and the turning process, Figure 6 is a plan view showing the operation amount of the steering operation tool, Figure 7(a) is an explanatory diagram of the operation of the small turn mode, Figure 7(b) is an explanatory diagram of the operation of the arbitrary turn mode, Figure 8(a) is an explanatory diagram of the operation of the on-the-spot rotation mode A, Figure 8(b) is an explanatory diagram of the operation of the diagonal steering mode, Figure 9(a) is an explanatory diagram of the operation of the on-the-spot rotation mode B, Figure 9(b) is an explanatory diagram of the operation of the pivot turn mode, and Figure 9(c) is an explanatory diagram of the operation of the left-right travel mode.

[0046] The driving modes are comprised of an arbitrary turning mode, a diagonal steering mode, and a left-right driving mode, and the turning modes are comprised of a small turning mode, an arbitrary turning mode, a spot turning mode A, a spot turning mode B, and a pivot turning mode.

[0047] The running mode and turning mode are used during transport running, seedling planting running (planting process) 59 and turning running (turning process) 58, and the configuration of each mode will be explained below, including a fixed condition ω, a fixed condition μ, turning centers (rotation centers or steering centers) Oa, Ob, Oc, Od, Oe, Of, Og, distance ratios L1, L2, L3, L4 from the turning centers Oa, Ob, Oc, Od, Oe, Of, Og to each wheel (wheel) 53, steering angle ratios θa, θb, θc, θd of each wheel 53, peripheral speed ratios v1, v2, v3, v4 of each wheel 53, steering control, and running drive control.

[0048] The above-mentioned certain condition ω is described in detail below. The certain condition ω is constituted by a state in which the timer T1 reaches 0 seconds after the start of planting, a state in which the drive of the planting work machine 3 has stopped, and a state in which the lift position of the planting work machine 3 is at a non-working height.

[0049] The certain condition μ is described in detail below. The certain condition μ is constituted by a state in which the driving of the planting implement 3 is stopped, a state in which the elevation position of the planting implement 3 is at a non-working height, and a state in which the riding rice transplanter 3 is stopped.

[0050] 5, 6, and 7(a), a detailed description will be given of the configuration of the tight turn mode of the riding rice transplanter 1. The tight turn mode is used when turning on the headland 56 of a paddy field.

[0051] In addition, the center of rotation for the tight turning mode is configured as the point Oa where two lines meet at the front of a position that is a width equivalent to half the planting row spacing of the planting device and below the front end of the seedling carrying table, laterally outward from the end planting position that corresponds to the inner side of the turning among the multiple planting positions on the planting device 22.

[0052] The steering control of the tight turn mode is configured so that, when the steering handle 11 is operated to the right or left θ1 while the certain condition ω is satisfied, the steering angle ratios θa, θb, θc, θd of each wheel 53 consisting of the left and right front wheels 4, 5 and the left and right rear wheels 6, 7 of the riding rice transplanter 1 are steered so that they point in the tangential direction from the turning center Oa to the position of each wheel 53, and the steering angle ratios θa, θb, θc, θd are maintained; and when the operation amount of the steering handle 11 is in the position of θ1 to the right or left and the certain condition ω is not satisfied, the steering control of the tight turn mode is switched to steering control of the arbitrary turn mode described below.

[0053] Furthermore, the running drive control in the tight turning mode is configured so that peripheral speed ratios v1, v2, v3, and v4 of the wheels 53 are set to the same ratios as the ratios L1, L2, L3, and L4 of the distances from the turning center Oa to the wheels 53, and when the operation amount of the steering handle 11 is operated to the right or left side θ1 while the certain condition ω is satisfied, the wheels 53 are driven by the operation amount of the main shift lever 18 and the peripheral speed ratios v1, v2, v3, and v4, and when the operation amount of the steering handle 11 does not satisfy the position of θ1 to the right or left side and the certain condition ω, the running drive control in the tight turning mode is switched to running drive control in an arbitrary turning mode, which will be described later.

[0054] The configuration of the optional turning mode will be described in detail with reference to Figures 5, 6, and 7(b). The optional turning mode is used when the riding rice transplanter 1 travels, travels to plant seedlings (planting process) 59, and changes direction at headlands 56 and corners 57 of the field.

[0055] In addition, the turning center of the arbitrary turning mode is located laterally outward from the turning center Oa of the tight turning mode, and the turning center Ob of the arbitrary turning mode is configured to change position from laterally outward from the turning center Oa of the tight turning mode to the side of the riding rice transplanter 1 depending on the amount of operation of the steering handle 11 to the right or left side by θ1 or more.

[0056] The steering control in the arbitrary turning mode is configured so that when the amount of operation of the steering wheel 11 is equal to or greater than θ1 to the right or left, the wheels 53 are steered in the tangent direction from the turning center Ob, which changes position depending on the amount of operation of the steering wheel 11, to the position of each wheel 53, and when the amount of operation of the steering wheel 11 is θ2 to the right or left, the steering control is configured so that the steering angle ratios θa, θb, θc, θd of each wheel 53 are maintained at 0 degrees.

[0057] Further, the travel drive control in the arbitrary turning mode is configured to set peripheral speed ratios v1, v2, v3, v4 of each of the wheels 53 to the same ratios L1, L2, L3, L4 as the ratios of the distances from the turning center Ob, the position of which is changed, to each of the wheels 53, in accordance with the amount of operation of the steering handle 11 to the right or left side of θ1 or more, and when the amount of operation of the steering handle 11 is θ1 or more, each of the wheels 53 is driven by the peripheral speed ratios v1, v2, v3, v4 of each of the wheels 53 in accordance with the amount of operation of the main speed change lever 18 and the amount of operation of the steering handle 11, and when the amount of operation of the steering handle 11 is θ2 to the right or left side, each of the wheels 53 is rotated at the same rotation speed in accordance with the amount of operation of the main speed change lever 18.

[0058] The configuration of the in-place rotation mode will be described in detail with reference to Figures 5, 6 and 8(a). In-place rotation mode A is used when changing direction at the four corners 57 of the field.

[0059] The rotation center Oc of the on-the-spot rotation mode A is configured as the point where the front-to-back center line and the left-to-right center line of the riding rice transplanter 1 intersect in a plan view.

[0060] Then, in the steering control of the on-the-spot rotation mode A, when the operation amount of the steering wheel 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, the steering wheel 11 is steered in accordance with the operation direction of the steering wheel 11 so that the steering angle ratio θa of the right front wheel 4 is oriented in the tangent direction from the rotation center Oc to the position of the right front wheel 4, the steering angle ratio θb of the left front wheel 5 is steered in accordance with the operation direction of the steering wheel 11 so that the steering angle ratio θc of the right rear wheel 6 is oriented in accordance with the rotation center Oc to the tangent direction from the rotation center Oc to the position of the left front wheel 5, and the steering angle ratio θc of the right rear wheel 6 is steered in accordance with the operation direction of the steering wheel 11 so that the steering angle ratio θa of the right front wheel 4 is oriented in the tangent direction from the rotation center Oc to the position of the left front wheel 5. The steering angle ratio θd of the left rear wheel 7 is steered so as to face the tangent direction at the position of the right rear wheel 6 from the center Oc, and the steering angle ratio θd of the left rear wheel 7 is steered so as to face the tangent direction at the position of the left rear wheel 7 from the rotation center Oc, and the steering angle ratios θa, θb, θc, θd of each wheel 53 are maintained, and when the operation amount of the steering handle 11 is at a position of θ1 or more on the right or left side and when the certain condition μ is not satisfied, the steering control of the on-the-spot rotation mode A is switched to the steering control of the arbitrary turning mode described above.

[0061] The running drive control of the on-the-spot rotation mode A is configured so that the peripheral speed ratios v1, v2, v3, and v4 of each of the wheels 53 are set to the same ratios as the ratios L1, L2, L3, and L4 of the distances from the rotation center Oc to each of the wheels 53, and when the operation amount of the steering handle 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, each of the wheels 53 is driven by the operation amount of the main shift lever 18 and the peripheral speed ratios v1, v2, v3, and v4, and when the operation amount of the steering handle 11 is at a position of θ1 or more to the right or left and the certain condition μ is not satisfied, the running drive control of the on-the-spot rotation mode A is switched to the running drive control of the arbitrary turning mode described above.

[0062] The configuration of the diagonal steering mode will be described in detail with reference to Figures 5, 6, and 8(b). The diagonal steering mode is used when traveling diagonally to plant seedlings in fields of various shapes, and when it is necessary to correct the position after turning around the headland.

[0063] In addition, the steering center for the diagonal steering mode is configured as the point where the line connecting the right front wheel 4 and the left rear wheel 7 of the riding rice transplanter 1 intersects with the line connecting the left front wheel 5 and the right rear wheel 6, which is the steering center Od for the diagonal steering mode.

[0064] The steering control of the diagonal steering mode is configured so that when the steering handle 11 is operated to a position of θ1 or more to the right or left, each of the wheels 53 is steered at the same steering angle ratio θa, θb, θc, θd according to the amount of operation of the steering handle 11, and when the steering handle 11 is in the range of θ2 to the right or left, the steering control of the diagonal steering mode is switched over to the steering control of the arbitrary turning mode described above.

[0065] Further, the traveling drive control of the diagonal steering mode is configured so that the peripheral speed ratios v1, v2, v3, and v4 of each of the wheels 53 are set to the same ratio, and when the operation amount of the steering handle 11 is operated to the right or left side within the range of θ1 and equal to or greater than θ2, each of the wheels 53 is rotated at the same rotation speed with the same peripheral speed ratios v1, v2, v3, and v4 of each of the wheels 53 in accordance with the operation amount of the main speed change lever 18, and when the operation amount of the steering handle 11 is within the range of θ2 to the right or left side, the traveling drive control of the diagonal steering mode is switched over to the traveling drive control of the arbitrary turning mode described above.

[0066] 5, 6, and 9(a), the configuration of the in-place rotation mode A will be described in detail. The in-place rotation mode B is used when changing direction at the four corners 57 of the field.

[0067] The rotation center Oe of the in-place rotation mode B is configured as the point where the line connecting the right front wheel 4 and the left rear wheel 7 intersects with the line connecting the left front wheel 5 and the right rear wheel 6.

[0068] Then, in the steering control of the on-the-spot rotation mode B, when the operation amount of the steering wheel 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, the steering wheel 11 is steered in accordance with the direction in which the steering wheel 11 is operated, so that the steering angle ratio θa of the right front wheel 4 is oriented in the tangential direction from the rotation center Oe to the position of the right front wheel 4, the steering angle ratio θb of the left front wheel 5 is steered in accordance with the direction in which the steering wheel 11 is operated, so that the steering angle ratio θc of the right rear wheel 6 is oriented in accordance with the rotation center Oe to the tangential direction from the rotation center Oe to the position of the left front wheel 5, The steering angle ratio θd of the left rear wheel 7 is steered so as to face the tangential direction at the position of the right rear wheel 6 from the rotation center Oe, and the steering angle ratio θd of the left rear wheel 7 is steered so as to face the tangential direction at the position of the left rear wheel 7 from the rotation center Oe, and the steering angle ratios θa, θb, θc, θd of each wheel 53 are maintained, and when the operation amount of the steering handle 11 is at a position of θ1 or more on the right or left side and when the certain condition μ is not satisfied, the steering control of the on-the-spot rotation mode B is switched to the steering control of the arbitrary turning mode described above.

[0069] Furthermore, the running drive control of the on-the-spot rotation mode B is configured so that peripheral speed ratios v1, v2, v3, and v4 of each of the wheels 53 are set to the same ratios as the ratios L1, L2, L3, and L4 of the distances from the rotation center Oe to each of the wheels 53, and when the operation amount of the steering handle 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, each of the wheels 53 is driven by the operation amount of the main shift lever 18 and the peripheral speed ratios v1, v2, v3, and v4, and when the operation amount of the steering handle 11 is at a position where θ1 is at least on the right or left side and the certain condition μ is not satisfied, the running drive control of the on-the-spot rotation mode B is switched to the running drive control of the arbitrary turning mode described above.

[0070] In the on-the-spot rotation mode A, the rotation center Oc is set at the center of the riding rice transplanter 1, so there is no risk of the riding rice transplanter 1 coming into contact with the ridge during rotation and being damaged.

[0071] In addition, in in-place rotation mode B, the center of rotation Oe is the point where the line connecting the right front wheel 4 and left rear wheel 6 of the riding rice transplanter 1 intersects with the line connecting the left front wheel 5 and right rear wheel 7, so the wheel trace after rotation is only one circle, which has the advantage of causing less damage to the field than in-place rotation mode A, and therefore either in-place rotation mode A or in-place rotation mode B may be adopted in the in-place rotation mode of the present invention.

[0072] The configuration of the pivot turning mode will be described in detail with reference to Figures 5, 6 and 9(b). The pivot turning mode is used when changing direction at the four corners 57 of the field.

[0073] In addition, the center of rotation of the pivot rotation mode is configured as the axis of the rotating support shaft 34 of the rear wheel (right rear wheel 6 or left rear wheel 7) that corresponds to the inside of the direction change of the riding rice transplanter 1 when viewed in a plane.

[0074] Then, in the steering control of the pivot turning mode, when the operation amount of the steering wheel 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, the steering wheel 11 is steered in accordance with the direction in which the steering wheel 11 is operated, so that the steering angle ratio θa of the right front wheel 4 is oriented in the tangent direction from the turning center Of to the position of the right front wheel 4, and the steering angle ratio θb of the left front wheel 5 is steered in accordance with the direction in which the steering wheel 11 is operated, so that the rear wheel (right rear wheel) on the inside of the turn is oriented in accordance with the direction in which the steering wheel 11 is operated. The steering angle (θc or θd) of the outer rear wheel (right rear wheel 6 or left rear wheel 7) is maintained at 0 degrees while the riding rice transplanter 1 is changing direction, and the steering angles θa, θb of the left and right front wheels 4, 5 are maintained while the riding rice transplanter 1 is changing direction.When the amount of operation of the steering handle 11 is at a position equal to or greater than θ1 and the certain condition μ is not satisfied, the steering control of the pivot turning mode is switched to the steering control of the arbitrary turning mode described above.

[0075] The pivot turning mode running drive control is configured so that, when the amount of operation of the steering handle 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, the peripheral speed ratios v1, v2, v3, v4 of each of the wheels 53 are set to the same ratios as the ratios L1, L2, L3, L4 of the distances from the turning center Of to each of the wheels 53, and each of the wheels 53 is rotated with respect to the peripheral speed ratios v1, v2, v3, v4 of each of the wheels 53 in accordance with the amount of operation of the main shift lever 18; when the amount of operation of the steering handle 11 is in a position of θ1 or more and the certain condition μ is not satisfied, the running drive control is switched from the pivot turning mode running drive control to the arbitrary turning mode running drive control described above.

[0076] The configuration of the left-right traveling mode will be described in detail with reference to Figures 5, 6, and 9(c). The left-right traveling mode is used when storing the vehicle in a warehouse.

[0077] In addition, the steering center for the left and right running mode is configured as the point where the line connecting the right front wheel 4 and the left rear wheel 7 of the riding rice transplanter intersects with the line connecting the left front wheel 5 and the right rear wheel 6, which is the steering center Og for the left and right running mode.

[0078] The steering control of the left / right running mode is configured so that, when the steering handle 11 is operated to the right or left by an amount equal to or greater than θ1 while the certain condition μ is satisfied, each of the wheels 53 is steered 90 degrees around the rotation support shafts 34, 34, 34, 34 in accordance with the direction in which the steering handle 11 is operated, and the steering angles θa, θb, θc, θd are maintained; and when the operation amount of the steering handle 11 is in a position equal to or greater than θ1 and the certain condition μ is not satisfied, the steering control of the left / right running mode is switched to the steering control of the arbitrary turning mode described above.

[0079] Furthermore, the running drive control in the left-right running mode is configured so that peripheral speed ratios v1, v2, v3, and v4 of each of the wheels 53 are set to the same ratios as the ratios L1, L2, L3, and L4 of the distances from the steering center Og to each of the wheels 53, and when the operation amount of the steering handle 11 is operated to the right or left by θ1 or more while the certain condition μ is satisfied, each of the wheels 53 is driven by the operation amount of the main shift lever 18 and the peripheral speed ratios v1, v2, v3, and v4, and when the operation amount of the steering handle 11 is in a position where θ1 is equal to or greater than θ1 and the certain condition μ is not satisfied, the running drive control in the left-right running mode is switched to the running drive control in the arbitrary turning mode described above.

[0080] Next, the mode switching means will be described with reference to Fig. 10 to Fig. 15. The mode switching means is composed of a control block diagram, a mode switching device, a main control flowchart, a travel mode selection control flowchart, a swing mode selection control flowchart, a steering control flowchart, and a work implement operation control flowchart. Fig. 10 is a control block diagram of the riding rice transplanter 1, and the input side (INPUT) of the control device (microcomputer) 29 is provided with a travel / steering mode selection switch 60, a mode selection switch 61, a steering handle potentiometer 62, a planting work lift position detection sensor 63, a steering handle torque sensor 64, rotation speed detection sensors 36a, 36b, 36c, 36d for each wheel 53, steering angle detection sensors 35a, 35b, 35c, 35d for each wheel 53, a brake detection potentiometer 65, a main transmission position detection potentiometer 20, a secondary Arranged on the output side are a gear position detection potentiometer 19, a work preparation switch 66, an operating tool (work machine operating tool) 67, etc., and on the output side are arranged travel drive motors 32a, 32b, 32c, 32d for each wheel 53, steering drive motors 33a, 33b, 33c, 33d for each wheel 53, motor drivers 31a, 31b, 31c, 31d for the travel drive motors, motor drivers 31e, 31f, 31g, 31h for the steering drive motors, a planting motor driver 38, a planting drive motor 39, and a steering handle motor driver 68.

[0081] As shown in Figures 10 and 11, the running / steering mode selection switch 60 is configured so that a mode can be selected from the running modes by pressing the front side of the running / steering mode selection switch 60, and so that a mode can be selected from the turning modes by pressing the rear side of the running / steering mode selection switch 60, allowing the operator to switch to a mode that suits his or her purpose from among the multiple running modes or turning modes selected by the running / steering mode selection switch 60. The steering wheel torque detection sensor 64 detects the operating torque of the steering wheel 11. The steering wheel potentiometer 62 detects the amount of operation (turn angle) of the steering wheel 11. The brake detection potentiometer 65 detects the amount of depression of the vehicle running / stop pedal 12.

[0082] The rotation speed detection sensors 36a, 36b, 36c, and 36d for the left and right front wheels 4, 5 and the left and right rear wheels 6, 7 constantly detect the rotation speeds of the left and right front wheels 4, 5 and the left and right rear wheels 6, 7. Vehicle speed and travel distance are calculated based on the detection signals from the rotation speed detection sensors 36a, 36b, 36c, and 36d for the left and right front wheels 4, 5 and the left and right rear wheels 6, 7. The steering angle detection sensors 35a, 35b, 35c, and 35d for the left and right front wheels 4, 5 and the left and right rear wheels 6, 7 constantly detect the steering angles θa, θb, θc, and θd of the left and right front wheels 4, 5 and the left and right rear wheels 6, 7. The main shift position detection potentiometer 20 detects the operating angle of the main shift lever 18. The auxiliary shift position detection potentiometer 19 detects the operating angle of the auxiliary shift lever 17. The planting implement lifting detection sensor 63 detects the lifting angle of the planting implement 3 in the working position or non-working position.

[0083] The motor drivers for each wheel output data to operate the steering drive motors 33a, 33b, 33c, and 33d and travel drive motors 32a, 32b, 32c, and 32d of the travel drive device 30 for each wheel 53 to target values ​​for the rotation direction, rotation speed, rotation angle, and peripheral speed ratios v1, v2, v3, and v4 in accordance with the mode set by the control device (microcomputer) 29. The steering drive motors 33a, 33b, 33c, and 33d for each wheel 53 are driven to rotate based on the data for the rotation direction and rotation angle output from the motor drivers 31e, 31f, 31g, and 31h for each wheel 53. The travel drive motors 32a, 32b, 32c, and 32d for each wheel 53 are driven to rotate based on the data for the rotation direction, rotation speed, and peripheral speed ratios v1, v2, v3, and v4 output from the motor drivers 31a, 31b, 31c, and 31d for each wheel 53.

[0084] Next, a detailed description will be given of the operation for selecting the travel mode and the swing mode by the microcomputer 29. The main control is performed based on the main control flowchart (flow) shown in Fig. 12, and the main control flow includes a travel mode / swing mode selection control for selecting and controlling a plurality of travel modes and swing modes, a steering control for operating each wheel 53 at a predetermined steering angle and predetermined peripheral speed ratios v1, v2, v3, v4 when the certain condition (ω or μ) of the selected mode is met, and a work machine operation control for automatically raising and lowering the planting work machine 3 and planting seedlings.

[0085] When the power is turned on and the main control flow starts, first, in the travel mode / turning mode selection control of step S1, the travel mode or turning mode is selected by operating the travel / turning mode selection switch 60, and the mode is set from the multiple modes of the selected travel mode or turning mode by operating the mode selection switch 61. The steering angle ratios θa, θb, θc, θd of each wheel 53, peripheral speed ratios v1, v2, v3, v4, and the turning centers (centers of rotation) Oa, Ob, Oc, Od appropriate for the selected mode are set, and the flow proceeds to steering control of step S2. If multiple setting conditions for the selected mode are met, the steering angle ratios θa, θb, θc, θd of each wheel 53 corresponding to the amount of operation of the steering handle 11 are set, or each wheel 53 is steered to the target steering angle ratios θa, θb, θc, θd, and the flow proceeds to work machine operation control of step S3, and the lifting and lowering of the planting work machine 3 is controlled.

[0086] The details of the travel mode selection control will be described. The travel mode selection control is performed based on the flow chart of the travel mode selection control as shown in FIG. 13(a). First, in the determination of "Is the mode selection switch 61 operated?" in step S101, if the result is YES, the process proceeds to the determination of "Travel mode selection: optional turning mode?" in step S102. If the result is YES in step S102, the process proceeds to step S103, where "the travel mode is set to diagonal travel, the maximum right turning angle of the steering wheel is set to +θa to +θd, and the maximum left turning angle is set to -θa to -θd," and the process returns to the determination of step S101 via RETURN. Also, if the determination of "Travel mode selection: optional turning mode?" in step S102 is NO, the process proceeds to step S104, where the planting travel mode is set to optional turning, the maximum right turning angle of the steering wheel is set to +θa to +θd, and the maximum left turning angle is set to -θa to -θd, and the process returns directly to the determination of step S101 via RETURN. If the determination in step S101 is NO, the process returns to the determination in step S101 via RETURN.

[0087] The details of the turning mode selection control will be explained. The turning mode selection control is performed based on the flowchart of the turning mode selection control as shown in Figure 13(b). First, in the determination of "Is the mode selection switch 61 operated downward?" in step S201, if the determination is YES, the process proceeds to the determination of "Turning mode selection: arbitrary turning mode?" in step S202, and if the determination in step S202 is YES, the process proceeds to step S203, where "the turning mode is set to a tight turn, and the target turning angle of each wheel 53 is set to θa to θd (-θa to -θd) in relation to the direction of operation of the steering wheel to the right or left", and then returns to the determination in step S201. Furthermore, if the determination of "Turning mode selection: arbitrary turning mode?" in step S202 is NO, the process proceeds to the determination of "Turning mode selection: sharp turn mode?" in step S204, and if the determination of step S204 is YES, the process proceeds to step S205, "Set the turning mode to on-the-spot turning, and set the target turning angle of the right or left side of the steering wheel to θa to θd (-θa to -θd)," and returns to the determination of step S201 via RETURN. Then, if the determination of "Turning mode selection: sharp turn mode?" in step S204 is NO, the process proceeds to step S206, "Set the turning mode to arbitrary turning, and set the target turning angle of the right or left side of the steering wheel to θa to θd (-θa to -θd)," and returns to the determination of step S201 via RETURN.

[0088] Furthermore, if the determination in step S201 of "Has the mode selection switch 61 been operated downward?" is NO, the process proceeds to step S207 of determining "Has the mode selection switch 61 been operated upward?", and if the determination in step S207 is YES, the process proceeds to step S208 of determining "Turning mode selection: optional turning mode?", and if the determination in step S208 is YES, the process proceeds to step S209 of "Set the turning mode to on-the-spot turning, and set the target turning angle of the right or left side of the steering wheel to θa to θd (-θa to -θd)", and then returns to the determination in step S201 via return. If the determination of "Turning mode selection: arbitrary turning?" in step S208 is NO, the process proceeds to the determination of "Turning mode selection: turning on the spot?" in step S210, and if the determination of step S210 is YES, the process proceeds to step S211, "Set the turning mode to tight turning, and set the target turning angle of the right or left side of the steering wheel to θa to θd (-θa to -θd)," and returns to the determination of step S201. Also, if the determination of "Turning mode selection: turning on the spot?" in step S210 is NO, the process proceeds to step S212, "Set the turning mode to arbitrary turning mode, and set the target turning angle of the right or left side of the steering wheel to θa to θd (-θa to -θd)," and returns to the determination of step S201. Then, in the determination of "Has the mode selection switch 61 been operated?" in step S207, if the result of step S207 is NO, the process returns to the determination in step S201.

[0089] Next, details of the steering control will be explained. The steering control is performed based on the flowchart of the steering control shown in Figure 14. First, in step S301, if the answer is YES in the determination of "Is the steering wheel 11 operation angle ≥ |θ1|?", the process proceeds to step S302 to determine "Is the turning mode a tight turn?" If the answer is YES in step S302, the process proceeds to step S303 to determine "Is the planting drive off?" If the answer is YES in step S303, the process proceeds to step S304 to determine "Is the planting timer T2 = 0?" If the answer is NO in step S304, the process proceeds to step S305 to determine "Is the planting timer T1 = 0?" If the answer is YES in step S305, the process proceeds to step S306 to determine "Is the planting timer T2 = 0?" The process then proceeds to step S306, which asks, "Is the steering direction of the steering wheel 11 to the right?" If the answer to step S306 is YES, the process proceeds to step S307, which asks, "Drive each of the steering motors 33a, 33b, 33c, 33d to the target turning angle +α1, +α2, +α3, +α4 of each wheel 53, set the peripheral speed ratios v1, v2, v3, v4 of each wheel 53 to the distance ratios L1, L2, L3, L4 from the turning center Oa to each wheel 53, and drive the steering wheel motor 68 in accordance with the steering amount," and the process then proceeds to step S308, where the process sets "turn on the automatic turning flag" and returns to the determination of step S301 via RETURN.

[0090] Regarding the planting timer T1 and planting timer T2, planting timer T1 is a predetermined time (seconds) from the planting drive on operation after the headland turns, and planting timer T2 is a predetermined time (seconds) from the planting drive off operation.

[0091] The process then proceeds to the determination of step S306, "Is the steering direction of the steering wheel 11 to the right?", and if the determination in step S306 is NO, the process proceeds to step S309, "driving each of the steering motors 33a, 33b, 33c, 33d to the target turning angles -α1, -α2, -α3, -α4, and setting the peripheral speed ratios v1, v2, v3, v4 of each wheel 53 to the distance ratios L1, L2, L3, L4 from the turning center Oa to each wheel 53, and driving the steering wheel motor 68 in accordance with the steering amount," and then the process goes to step S308, "turning the automatic turning flag ON," and returns to the determination in step S301 via RETURN.

[0092] Then, if the answer to the question "Is planting drive off?" in step S303 is NO, or if the answer to the question "Is planting timer T2=0?" in step S304 is YES, or if the answer to the question "Is planting timer T1=0?" in step S305 is NO, the process returns to the decision in step S301.

[0093] If the answer to the question "Is the turning mode a tight turn?" in step S302 is NO, the process proceeds to step S310 to determine "Is the turning mode a turn on the spot?", and if the answer to the question is YES in step S310, the process proceeds to step S311 to determine "Is the planting implement 3 at a predetermined height or above?", and if the answer to the question is YES in step S311, the process proceeds to step S312 to determine "Has the machine stopped traveling?", and if the answer to the question is YES in step S312, the process proceeds to step S313 to determine "The direction of operation of the steering handle 11 is determined." If the answer to step S313 is YES, the process proceeds to step S314, where "the steering motors 33a, 33b, 33c, and 33d are driven to the target turning angles θa to θd of the wheels 53, the peripheral speed ratios v1, v2, v3, and v4 of the wheels 53 are set to the same value, and the steering wheel motor 68 is driven in accordance with the steering amount," and the process proceeds to step S308, where the "automatic turning flag is turned ON" is set, and the process returns to the decision of step S301 via RETURN.

[0094] Then, the process proceeds to the determination of "Is the steering wheel 11 turned to the right?" in step S313, and if the determination in step S313 is NO, the process proceeds to step S315, in which "each steering motor 33a, 33b, 33c, 33d is driven to the target turning angle -θa to -θd of each wheel 53, peripheral speed ratios v1, v2, v3, v4 of each wheel 53 are set to the same value, and the steering wheel motor 68 is driven in accordance with the steering amount," and the process proceeds to step S308, in which "the automatic turning flag is set to ON," and the process returns to the determination in step S301 via RETURN.

[0095] Furthermore, if the determination in step S310 of "Is the turning mode turning on the spot?" is NO, or if the determination in step S311 of "Is the planting work machine 3 above a predetermined height?" is NO, or if the determination in step S312 of "Has the machine stopped running?" is NO, the process returns to the determination in step S301 via RETURN.

[0096] If the determination in the aforementioned step S301 of "Is there an operation to the steering wheel 11 operation angle ≧|θ1|?" is NO, the process proceeds to step S316 of determining "Is the steering wheel 11 operation angle ≧|θ2|?" If the determination in step S316 is YES, the process proceeds to step S317 of determining "Is the automatic turn flag ON?" If the determination in step S317 is YES, the process proceeds to step S318 of determining "Is the value of the torque detection sensor 64 ≧b?" If the determination in step S318 is YES, the process proceeds to step S319 of "setting the automatic turn flag OFF, and driving the steering wheel motor 68," and in step S320 of "turning the direction of each wheel 53 in the tangential direction around the same turning center Ob in accordance with the amount of operation of the steering wheel 11, and setting the peripheral speed ratios v1, v2, v3, and v4 of each wheel 53 to the distance ratios L1, L2, L3, and L4 from the turning center Ob to each wheel 53," and then returns to the determination in step S301.

[0097] Regarding the value b of step S318 above or the value a of step S321 below, the value a of "value of torque detection sensor 64 ≧ a?" in step S321 above is a slow operation with a small operating force on the steering wheel 11, and the value of the torque detection sensor 64 is the set value (small), and the value b of "value of torque detection sensor 64 ≧ b?" in step S318 below is a fast operation with a large operating force on the steering wheel 11, and the value of the torque detection sensor 64 is the set value (large).

[0098] Also, if the determination in step S318 "Is the value of the torque detection sensor 64 ≧ b?" is NO, the process returns to the determination in step S301 via RETURN.

[0099] If the determination of "Is the automatic turning flag ON?" in step S317 is NO, the process proceeds to step S321, where it determines "Is the value of the torque detection sensor 64 ≧ a?" If the determination of step S321 is YES, it operates "to drive the steering wheel motor 68" in step S322, and proceeds to step S323, where it determines "The operating angle of the steering wheel 11 ≧ |θ1|?" If the determination of step S323 is NO, it proceeds to step S324, where it determines "Is the driving mode a diagonal driving mode?" If the determination of step S324 is YES, it proceeds to step S325, where in step S325 "the direction of each wheel 53 is operated by the same amount in accordance with the amount of operation of the steering wheel 11, and the peripheral speed ratios v1, v2, v3, v4 of each wheel are set to the same value," and then it returns to the determination of step S301 via RETURN.

[0100] Furthermore, if the determination in step S323 of "Is the steering wheel 11 operating angle ≧|θ1|?" is YES, the process proceeds to step S320, where "the orientation of each wheel 53 is operated in the tangential direction around the same turning center Od in accordance with the amount of operation of the steering wheel 11, and the peripheral speed ratios v1, v2, v3, and v4 of each wheel 53 are set to the distance ratios L1, L2, L3, and L4 from the turning center Od to ​​each wheel 53," and the process returns to the determination in step S301.

[0101] If the determination in step S324 "Is the selected driving mode the diagonal driving mode?" is NO, the process proceeds to step S320, where "the direction of each wheel 53 is operated in the tangential direction around the same turning center Od in accordance with the amount of operation of the steering wheel 11, and the peripheral speed ratios v1, v2, v3, and v4 of each wheel 53 are set to the distance ratios L1, L2, L3, and L4 from the turning center Od to ​​each wheel 53," and the process returns to the determination in step S301.

[0102] Furthermore, if the determination in step S316 of "Is the operation angle of the steering wheel 11 ≧|θ2|?" is NO, the process proceeds to step S326, where "When the operation angle of the steering wheel 11 is ≦|θ2|, the steering angle of each wheel 53 is set to be maintained at 0 degrees, and the peripheral speed ratios v1, v2, v3, v4 of each wheel 53 are set to be the same" is executed, and the process returns to the determination in step S301.

[0103] If the determination in step S321 of "Is the value of the torque detection sensor 64 ≧ a?" is NO, the process proceeds to step S326, where "when the operating angle of the steering wheel 11 is ≦|θ2|, the steering angle of each wheel 53 is set to be maintained at 0 degrees, and the peripheral speed ratios v1, v2, v3, v4 of each wheel 53 are set to be the same", and the process returns to the determination in step S301.

[0104] Next, details of the work machine operation control will be explained. As shown in Fig. 15, the work machine operation control can perform the lifting and lowering operation of the planting work machine 3 of the riding rice transplanter 1, the lifting and stopping operation, and the drive on / off operation of the planting device 22 by turning on / off the work preparation switch 66 and by operating the operation tool (work machine operation tool) 67 downward or upward.

[0105] The ON / OFF operation of the work preparation switch will now be described. When the work preparation switch 66 is turned ON, the planting work machine 3 can be raised and lowered, the lifting stop operation can be performed, and the planting device 22 can be driven on and off by operating the operating tool 67 downward or upward. When the work preparation switch 66 is turned OFF, the planting work machine 3 can be raised and lowered and the lifting stop operation can be performed, other than the planting device 22 being driven on and off, by operating the operating tool 67 downward or upward.

[0106] Based on the flowchart (flow) of the work machine operation control shown in Figure 15, we will explain the lifting operation, lowering operation, planting drive operation, planting drive stop operation, lifting and lowering stop operation when lifting, and lifting and lowering stop operation when lowering of the planting work machine 3 of the riding rice transplanter 1.

[0107] The planting work implement 3 is lowered by first operating the operating tool 67 downward once while the work preparation switch 66 is turned ON, and based on the work implement operation control flowchart, in step S401, the determination of "Is the operating tool 67 operated downward?" is made. If step S401 returns YES, the process proceeds to step S402. In step S402, the determination of "work preparation switch 66" is made. If step S402 returns ON, the process proceeds to step S403. In step S403, the determination of "work implement 3: rising?" is made. If the planting work implement 3 is rising, the determination in step S403 returns YES, and the process proceeds to step S421. In step S421, the setting of "work implement 3: fixed" stops the planting work implement 3 from rising, and returns to step S401 via return. Furthermore, if the planting work machine 3 has stopped rising, step S403 is judged as NO and the process proceeds to step S404. In step S404, when the question "Work machine 3: automatic lift (lowering)?" is asked, the planting work machine 3 has stopped rising, so step S404 is judged as NO and the process proceeds to step S405. In step S405, when the question "Work machine 3: planting?" is asked, the planting work machine 3 has stopped rising and the planting device 22 has stopped driving, so step S405 is judged as NO and the process proceeds to step S406. In step S406, the question "Work machine 3: automatic lift (lowering)" is asked, so the planting work machine 3 begins to lower, the planting work machine 3 is set to the automatic lift (lowering) state, and the process returns to step S401 via RETURN.

[0108] Then, based on the work machine operation control flowchart, the drive stop state of the planting device 22 and the automatic raising and lowering state of the planting work machine 3 are maintained until the next operation of the operating tool 67 is performed. In the determination of "Is the operating tool 67 operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and the process sets NO in step S401 and proceeds to step S407. In the determination of "Is the operating tool 67 operated upward?" in step S407, it is determined that the operating tool 67 has not been operated upward, and the process sets NO in step S407 and proceeds to step S408. In the determination of "Is the planting clutch waiting to engage?" in step S408, it is determined that the planting clutch is not waiting to engage because the "planting clutch waiting to engage" state in step S411 in the work machine operation control flowchart for the lowering operation of the planting work machine 3 has not been passed, and the process sets NO in step S408 and returns to step S401, repeatedly repeating the determination process.

[0109] The planting drive operation of the planting work machine is performed by first operating the operating tool 67 downward once while the work preparation switch 66 is turned ON, the planting drive is stopped, and the planting work machine 3 is in the automatic raising / lowering state, and based on the work machine operation control flowchart, in the determination of "Is the operating tool 67 operated downward?" in step S401, it is determined that the operating tool 67 has been operated downward, and step S401 judges YES and proceeds to step S402, in the determination of "work preparation switch 66" in step S402 it is determined that step S402 is in the ON state and proceeds to step S403, and in the determination of "Work machine: rising?" in step S403, it is determined that the planting work machine 3 is automatically raised / lowered (or lowered), ) so step S403 is judged as NO and the process proceeds to step S404, and in the determination of "Working machine 3: automatic lifting (lowering)?" in step S404, the planting working machine 3 is in the automatic lifting (lowering) state so step S404 is judged as YES and the process proceeds to step S409, and in the determination of "Working machine 3 lowering operation stopped?" in step S409, if the planting working machine 3 is in the state where its lowering operation has stopped then step S409 is judged as YES and the process proceeds to step S410, and in step S410 "Working machine 3: planting" and "timer T1: set" drive the planting device 22 of the planting working machine 3 and start planting the seedlings, and at the same time set (start) the planting timer T1, and then return via RETURN to step S401.

[0110] Furthermore, based on the above-mentioned work machine operation control flowchart, in order to maintain the automatic raising / lowering state of the planting work machine 3, the drive state of the planting device 22, and the measurement of the planting timer T1 until the next operation of the operating tool 67, in the determination of "Is the operating tool 67 operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and the process proceeds to step S407 with "NO" in step S401, and in the determination of "Is the operating tool 67 operated upward?" in step S407, it is determined that the operating tool 67 has not been operated downward. 7 has not been operated upward, so step S407 is judged as NO and the process proceeds to step S408, and in the judgment of "Is the planting clutch in a waiting state?" in step S408, since the "planting clutch in a waiting state" of step S411 in the flowchart of the work machine operation control for the lowering operation of the planting work machine 3 and the drive-on operation of the planting device 22 has not been passed, step S408 is judged as NO and the process goes through return and the judgment to return to step S401 is repeated.

[0111] If the planting implement 3 is in the process of descending, in the determination of "Has the implement 3 been lowered?" in step S409, the result of step S409 is determined to be NO, the process proceeds to step S411, the state is set to "waiting for the planting clutch to engage" in step S411, and the process returns to step S401 via the return process.

[0112] Furthermore, when the planting implement 3 stops descending from the state in which it was in the process of descending, based on the flowchart of the implement operation control, in the determination of "Is the operating tool 67 operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and the process proceeds to step S407 with a NO decision in step S401, and in the determination of "Is the operating tool 67 operated upward?" in step S407, it is determined that the operating tool 67 has not been operated upward, and the process proceeds to step S408 with a NO decision in step S407, and in the determination of "Is the planting clutch engaged?" in step S408, it is determined that "the planting clutch is engaged?" in step S411. Since the state is set to "waiting for a switch input", step S408 is judged as YES and the process proceeds to step S412, and in the determination of "Has work implement 3 lowering operation stopped?" in step S412, if the work implement 3 is in the process of lowering, the determination is made as NO and the process returns to step S401, and the process is repeated; if the work implement 3 has stopped lowering, the process proceeds to step S413, and the planting device 22 of the planting work implement 3 is driven by "Work implement 3: planting" and "Timer T1: set" in step S413, and the planting timer T1 is set (started) at the same time as the start of seedling planting, and the process returns to step S401.

[0113] Then, based on the work machine operation control flowchart, the automatic raising / lowering state of the planting work machine 3, the drive state of the planting device 22, and the measurement of the planting timer T1 are maintained until the next operation of the operating tool 67 is performed. In the determination of "Has the operating tool 67 been operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and step S401 is set to NO, and the process proceeds to step S407. In the determination of "Has the operating tool 67 been operated upward?" in step S407, it is determined that the operating tool 67 has not been operated upward, and step S407 is set to NO, and the process proceeds to step S408. In the determination of "Is the planting clutch on-waiting state?" in step S408, since the planting clutch is on as described above, it is determined that the planting clutch is not on-waiting state, and step S408 is set to NO, and the process returns to step S401, and the process is repeated.

[0114] The planting clutch disengagement operation is performed by first operating the operating tool 67 upward once while the work preparation switch 66 is turned ON, the planting implement 3 is in the automatic lifting (lowering) state, and the planting drive is in the "ON" state. Based on the work implement operation control flowchart, in the determination of "Is the operating tool 67 operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and the process enters NO in step S401 and proceeds to step S407. In the determination of "Is the operating tool 67 operated upward?" in step S407, it is determined that the operating tool 67 has been operated upward, and the process enters YES in step S407 and proceeds to step S414. In the determination of "Is the planting implement: raised?" in step S414, the planting implement 3 is in the automatic lifting (lowering) state, so the process enters NO. It is determined that this is the case and the process proceeds to step S415, and in the determination of "Work implement 3: automatic lift (lower)?" in step S415, when the planting clutch is engaged, the planting implement lift detection sensor 63 of the float (center float) 23 indicates that it is grounded on the field, so the result is NO and the process proceeds to step S416, and in the determination of "Work implement 3: planting?" in step S416, the planting clutch is engaged, so the result is YES and the process proceeds to step S417, and in step S417, "Work implement 3: automatic lift (lower)" and "Timer T2: set" are set so that the planting implement 3 is in the automatic lift (lower) state, the planting device 3 is stopped, and the planting drive stop timer T2 is set (started) simultaneously with the planting device 22 stopping, and the process returns to step S401 via RETURN.

[0115] In addition, based on the work machine operation control flowchart, the drive stop state of the planting device 22, the automatic raising / lowering state of the planting work machine 3, and the measurement of the planting drive stop timer T2 are maintained until the next operation of the operating tool 67 is performed, so that in the determination of "Has the operating tool 67 been operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and step S401 is set to NO, and the process proceeds to step S407, in the determination of "Has the operating tool 67 been operated upward?" in step S407, it is determined that the operating tool 67 has not been operated upward, and step S407 is set to NO, and the process proceeds to step S408, in the determination of "Is the planting clutch on-waiting state?" in step S408, it is determined that the planting clutch is not on-waiting state, and step S408 is set to NO, and the process returns to step S401, and the determination is repeated.

[0116] The operation of raising the planting implement is performed by first operating the operating tool 67 upward once when the planting drive is stopped and the planting implement 3 is in the automatic raising (lowering) state, and based on the implement operation control flowchart, in the determination of "Is the operating tool 67 operated downward?" in step S401, it is determined that the operating tool 67 has not been operated downward, and the answer to step S401 is NO, and the process proceeds to step S407, in the determination of "Is the operating tool 67 operated upward?" in step S407, it is determined that the operating tool 67 has been operated upward, and the answer to step S407 is YES, and the process proceeds to step S414, in the determination of "Is the implement 3 raised?" in step S414, it is determined NO because the planting implement 3 is in the automatic raising (lowering) state, and the process proceeds to step S415, in the determination of "Is the implement 3: raised?" in step S415, it is determined NO, and the process proceeds to step S415, In the determination of "Lifting (lowering)?", the planting work machine 3 is in the automatic lifting (lowering) state, so a YES is determined and the process proceeds to step S418. In the determination of "Work machine 3 lowering operation stopped?" in step S418, if the planting work machine 3 is descending, a YES is determined in step S418 and the process proceeds to step S420. In step S420, the "Work machine 3: fixed" setting is set to stop the descent of the planting work machine 3 that is descending. If the planting work machine 3 is in the automatic lifting (lowering) state, a NO is determined in step S418 and the process proceeds to step S419. In step S419, the "Work machine 3: rising?" setting is set to stop the planting work machine 3 that is automatically lifting (lowering) at the raised and non-working height, and the process returns to step S401 via RETURN.

[0117] Furthermore, based on the work machine operation control flowchart, the drive stop state of the planting device 22, the raised and stopped state of the planting work machine 3, and the measurement of the planting drive stop timer T2 are maintained until the next operation of the operating tool 67 is performed, so that in the determination of "Is the operating tool 67 operated downward?" in step S401, if it is determined that the operating tool 67 has not been operated downward, step S401 is judged as NO and the process proceeds to step S407, in the determination of "Is the operating tool 67 operated upward?" in step S407, if it is determined that the operating tool 67 has not been operated upward, step S407 is judged as NO and the process proceeds to step S408, and in the determination of "Is the planting clutch waiting to engage?" in step S408, since the planting work machine 3 is in the raised state, it is determined that it is not in the planting clutch waiting to engage, and step S408 is judged as NO and the process returns to step S401, repeatedly repeating the determination. [Explanation of symbols]

[0118] 1. Riding rice transplanter (machine) 2 Running body 3 Planting machine 4,5 front wheels 6,7 rear wheels 11 Steering operation device (steering handle) 29 Control unit (microcomputer) 30 Traveling steering device 31a, 31b, 31c, 31d Motor drivers for travel drive motors 31e, 31f, 31g, 31h Motor drivers for steering drive motors 32a, 32b, 32c, 32d Travel drive motor 33a, 33b, 33c, 33d Steering drive motor 34 Rotation support shaft 35a, 35b, 35c, 35d Steering angle detection sensors 36a, 36b, 36c, 36d Rotation speed detection sensors 37 Planting drive device 47 axles 50 Axle Case 53 Each wheel (wheel) Oa, Ob, Oc, Od, Oe, Of, Og Center of rotation (center of rotation) v1,v2,v3,v4 Peripheral speed ratio L1, L2, L3, L4 distance ratio θa, θb, θc, θd Steering angle ratio (maximum steering angle, target steering angle) θ1, θ2 Amount of steering wheel operation

Claims

1. In the riding rice transplanter (1), a planting implement (3) is coupled to the rear of a traveling body (2) having left and right front wheels (4, 5) and rear wheels (6, 7), and a traveling steering device (30) is provided for independently driving and steering each wheel (53) of the left and right front wheels (4, 5) and the rear wheels (6, 7), and the riding rice transplanter (1) operates the traveling steering device (30) via a control unit (29) by operating a steering operation tool (11). In this riding rice transplanter (1), the control unit (29) changes the control mode of the traveling steering device (30) to steer each wheel (53) perpendicular to a line connecting a turning center (Oa) of the body (1) approximately half the row spacing from the innermost planting position in the turning direction in a plan view and the driving rotation center of each wheel (53), by operating the steering operation tool (11) to a predetermined value or more. The riding rice transplanter (1) is characterized by being equipped with a mode switching means that can switch between a tight-turning mode in which the wheels (53) are steered independently and driven independently so that the peripheral speed ratios (v1, v2, v3, v4) of the wheels (53) are the same as the ratios (L1, L2, L3, L4) of the planar distances between the turning center (Oa) and the drive rotation centers of the wheels (53), and an arbitrary turning mode in which the wheels (53) are steered in proportion to the amount of operation of the steering operating device (11) so as to face the tangent direction of a circle with the same point as the turning center (Ob) and driven independently so that the peripheral speed ratios (v1, v2, v3, v4) of the wheels (53) are the same as the ratios (L1, L2, L3, L4) of the planar distances between the same point and the drive rotation centers of the wheels (53).

2. Turn-in-place mode The mode switching means can switch the control mode of the traveling steering device (30) to an on-the-spot rotation mode by operating the steering operating device (11) at a predetermined level or more, in which each wheel (53) is independently steered so that it is perpendicular to a line connecting the rotation center (Oc or Oe) of the body (1) located on the left-right center line of the body (1) in a plan view and the drive rotation center of each wheel (53), and the peripheral speed ratio (v1, v2, v3, v4) of each wheel (53) is the same as the ratio (L1, L2, L3, L4) of the planar distance between the rotation center (Oc or Oe) of the body (1) and the drive rotation center of each wheel (53).

3. Diagonal driving The riding rice transplanter (1) according to claim 1 or 2, characterized in that the mode switching means can switch the control mode of the traveling steering device (30) to a diagonal steering mode in which each wheel (53) is steered in the same direction by the same amount in proportion to the amount of operation of the steering operating device (11), and driven so that the peripheral speed ratios (v1, v2, v3, v4) of each wheel (53) are the same.

4. Wheel and axle relationship A riding rice transplanter (1) as described in claim 1, claim 2, or claim 3, characterized in that the axle cases (50) that support each of the wheels (53) are configured to be rotatable relative to the body (1) via vertical pivot shafts (34), and in a plan view, the intersection of the left-right center line of the ground contact portion (71) of the wheel (53) and the axis of the axle (47) is configured to coincide with the pivot shaft (34).

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