Agricultural work vehicle

Abstract

To provide a work vehicle lifting control system mounted on an agricultural work vehicle that is configured at low costs as compared with a conventional product.SOLUTION: In an agricultural work vehicle 10 mounted with a work machine 17 which can be lifted with a lifting device 33, a machine body altitude of the agricultural work vehicle 10 is measured by a satellite positioning device 7; a work machine height difference from the satellite positioning device 7 to the work machine 17 is calculated by altitude calculation means 31; an altitude of the work machine 17 is calculated from the machine body altitude and the work machine height difference; and the work is performed by keeping the work machine 17 at a desired height by controlling the lifting device 33.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine that is attached to the rear of an agricultural work vehicle and plows the ground. [Background technology]

[0002] One technology for an agricultural work vehicle is described in JP 2021-193899 A. This agricultural work vehicle has a work implement attached to the vehicle body via a lifting device, and the lifting device is controlled by satellite positioning devices installed on both the vehicle body and the work implement to maintain the work implement at a constant altitude while cultivating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-193899 Summary of the Invention [Problem to be solved by the invention]

[0004] A satellite positioning device receives radio waves from multiple positioning satellites orbiting the Earth and measures the altitude along with the vehicle's position on a map. The agricultural work vehicle's work implements are equipped with advanced satellite positioning devices on both the vehicle body and the implement to control the lifting and lowering of the implement, which makes the lifting and lowering control system for the implement expensive.

[0005] An object of the present invention is to provide a work machine lifting control system that is less expensive than conventional systems. [Means for solving the problem]

[0006] The above-mentioned object of the present invention is achieved by the following technical means.

[0007] The invention of claim 1 is an agricultural work vehicle in which a work implement 17 is attached to the agricultural work vehicle 10 so that it can be raised and lowered by a lifting device 33, the vehicle altitude of the agricultural work vehicle 10 is measured by a satellite positioning device 7, the difference in work implement altitude from the satellite positioning device 7 to the work implement 17 is calculated by an altitude calculation means 31, the altitude of the work implement 17 is calculated from the vehicle altitude and the difference in work implement altitude, and the lifting device 33 is controlled to maintain the work implement 17 at a desired altitude while it works.

[0008] The invention of claim 2 is a ground leveling machine for an agricultural work vehicle as described in claim 1, characterized in that a lifting device 33 is formed by connecting a lifting lower link 28b, a reference lower link 28c, and the lifting lower link 28b, which connect the body of the agricultural work vehicle 10 and the work implement 17, with a lift rod 28a that connects the lifting lower link 28b to a lift arm 27 of the body, and the height difference of the work implement 17 is detected by detecting the rotation angle of the lift arm 27.

[0009] The invention of claim 3 is the ground leveling implement for an agricultural vehicle according to claim 2, characterized in that a horizontal sensor 35 for detecting the horizontal position of the implement 17 is provided on the reference lower link 28c. [Effects of the Invention]

[0010] In the invention of claim 1, the altitude of the work implement 17 is calculated by correcting the vehicle altitude measured by the satellite positioning device 7 installed on the agricultural work vehicle 10 with the difference in work implement altitude calculated by the altitude calculation means 31, and the lifting device 33 is controlled to raise and lower so that the work implement 17 is maintained at the desired altitude, so that work can be carried out with just one expensive satellite positioning device 7 and the work implement 17 at the desired altitude.

[0011] In the invention of claim 2, the body of the agricultural work vehicle 10 and the work implement 17 are connected by a lift rod 28a which connects the lifting lower link 28b, the reference lower link 28c and the lifting lower link 28b to the lift arm 27 of the body to form a lifting device 33, so that the difference in elevation of the work implement 17 relative to the body of the agricultural work vehicle 10 is calculated from the rotation angle of the lift arm 27, simplifying the height calculation means 31 of the work implement 17.

[0012] In the invention of claim 3, the reference lower link 28c connecting the agricultural work vehicle 10 and the work implement 17 is less likely to tilt left or right, and the horizontal sensor 35 installed there can detect the left and right horizontality of the work implement 17 in a stable state with little fluctuation. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a right side view of a tractor as an agricultural work vehicle according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram showing the elevation of a work implement; [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description of the embodiment, the left and right directions facing the forward direction of the aircraft are referred to as left and right, respectively, and the forward direction is referred to as front and the backward direction is referred to as rear, but this does not limit the configuration of the present invention.

[0015] Figure 1 shows a tractor 10 as an agricultural work vehicle, and its overall configuration will be described. The tractor 10 is equipped with a diesel engine E inside the hood 11. The rotational power of this engine E is appropriately reduced by various transmissions inside a transmission case 18 and transmitted to two wheels (left and right rear wheels 2R, 2L) or four wheels (left and right front and rear wheels 1R, 1L, 2R, 2L) that serve as the traveling gear, for propulsion. A PTO shaft 15 protruding from the rear of the vehicle drives a work implement 17. A satellite positioning device 7 is mounted on the roof of the cabin 12 and receives radio waves from multiple positioning satellites to determine the tractor 10's location on a map and its altitude. Placing the satellite positioning device 7 near the mounting portion of the lifting device 33 that connects the work implement 17 to the tractor 10 simplifies the altitude calculation means 31, as the altitude of the tractor 10 is closer to that of the work implement 17. Furthermore, when the work implement 17 is a tillage implement, if the altitude of the work implement 17 is taken as the tillage shaft position, the tillage shaft position becomes the altitude of the work implement 17.

[0016] In addition, a steering handle 16 for steering the left and right front wheels 1R, 1L is provided in front of a driver's seat 20 installed inside the cabin 12, protruding upward from an operation box 13. Below this are provided a lift lever 14 for raising and lowering a work implement 17 with a single touch, a forward / reverse lever 19 for switching the vehicle between forward and reverse, and an accelerator lever (illustration omitted) for adjusting the engine E rotation speed. A forward switch and a reverse switch for detecting the operator's forward / reverse operation and neutral position operation are provided at the rotation base of the forward / reverse lever 19, and a lever holding mechanism made of a friction material is provided at the rotation base of the accelerator lever, which is connected via a wire or the like to a governor mechanism installed on the side of the engine E. In addition, a front wheel turning angle sensor is provided at the linkage portion of the steering handle 16, more specifically, at the pitman arms of the front wheels 1R, 1L, as a means for detecting the vehicle's turning operation.

[0017] A meter panel controller is mounted on the back side above and in front of the steering handle 16, and a meter panel 22 equipped with various pilot lights, an engine tachometer, an LCD display, etc. is provided on the front, allowing the user to input the type of agricultural work to be performed by the work implement 17. Also, below the meter panel 22 are a work changeover dial, a PTO on / off switch that turns on and off the rotation of the PTO shaft 15 protruding from the rear of the vehicle, and an independent PTO control on / off switch that selects whether the rotation of the PTO shaft 15 is turned on and off manually or automatically in conjunction with the elevation or lowering state of the work implement, etc. A PTO rotation sensor 29 is provided on the PTO shaft 15 to detect rotation.

[0018] Furthermore, below the steering wheel 16 are provided a clutch pedal 24, left and right brake pedals, and an accelerator pedal 23. The base of the accelerator pedal 23 is provided with a biasing mechanism that returns the engine speed to the deceleration side, and the engine speed is adjusted by stepping on this mechanism or by rotating the accelerator lever back and forth, and the engine speed is detected by an engine speed sensor provided on the engine output shaft.

[0019] In addition, a position lever 21 is provided on the side of the operator's seat 20 to change the height of the tillage equipment, which is the work equipment 17 at the rear of the vehicle body, and a potentiometer is provided at the base of this position lever 21 to detect the operating position.The working equipment (tilage equipment) 17 is raised and lowered by matching the operating angle of this lever with the operating angle of the lift arm 27, which will be described later.

[0020] Further, an upper portion of the transmission case 18 is provided with an elevator cylinder 26 incorporating a hydraulic cylinder for lifting and lowering a work implement that constitutes a work implement lifting device 33. A lift arm 27 is rotated up and down by extension and retraction of a piston of this elevator cylinder 26, and a left-side lower elevator link 28b and a right-side lower reference link 28c that connect the transmission case 18 and the work implement 17 are connected to the lift arm 27 by a lift rod 28a. The lift rod 28a includes a double-acting horizontal control hydraulic cylinder 28d, and extension and retraction of this horizontal control hydraulic cylinder 28d raises and lowers the left-side lower elevator link 28b of the work implement 17, thereby maintaining it horizontally. Further, the top link 34 is connected to the work implement 17 via a top link bracket 31a. In this way, the lifting device 33 is configured to raise and lower various types of work implement 17 (a rotary tiller in the illustrated example) via the lifting device 33 (three-point linkage) which connects the work implement 17 to the traveling body 2 so that it can be raised and lowered by the lower links 28b, 28c and the top link 34. In addition, an altitude sensor 30 which detects the height of the work implement 17 is provided at the base of the lift arm 27.

[0021] Furthermore, the height sensor 30 may be provided on the pivot shaft that is the base end of the right-side reference lower link 28c opposite the left-side lower lift link 28b connected to the lift rod 28a. Note that a weight sensor may be provided on the lower lift link 28b to detect the weight of the work machine.

[0022] In this way, by raising the work implement 17, the work implement 17 is moved to a non-working position. The non-working position is a position where the work implement 17 is raised when, for example, the machine body is moving backward, turning, or traveling on a road. In addition, by lowering the work implement 17, the work implement 17 is moved to a ground work position.

[0023] When the tractor 10 is horizontal from front to back, the height of the work implement 17 is detected by the altitude sensor 30 as the height relative to the tractor 10, but when the tractor 10 is tilted forward, as shown in Figure 2, the altitude of the work implement 17 approaches the altitude of the machine body, so the height of the work implement 17 is corrected by the fore-and-aft tilt angle α of the machine body, and the lifting device 33 is controlled so that the work implement 17 reaches the set altitude.

[0024] In addition, the height of the work implement 17 is calculated using the horizontal tilt angle β from a distance sensor 45 such as an infrared sensor installed on the satellite positioning device 7 of the tractor 10 toward the target point 46 of the work implement 17 and the distance L between the distance sensor 45 and the target point 46, and correction is made to use this as the altitude of the work implement 17.

[0025] Figure 3 is a block diagram of the automatic control, in which the altitude of the tractor 10 body from the satellite positioning device 7, the fore-aft tilt angle of the tractor 10 from the body tilt sensor 55, the height difference of the work implement 17 from the altitude sensor 30, the left-right levelness of the work implement 17 from the horizontal sensor 35, and the distance between the tractor 10 and the work implement 17 from the distance sensor 45 are input to the control device 5, and a signal to correct the lift height of the work implement 17 is output to the lifting cylinder 26, and a signal to correct the left-right level of the work implement 17 is output to the horizontal control hydraulic cylinder 28d.

[0026] FIG. 4 is a side view of the connection between the transmission case 18 of the tractor 10 and the work implement 17. The left side of the transmission case 18 is connected to the left side of the frame of the work implement 17 by a lower lifting link 28b, and the right side of the transmission case 18 is connected to the right side of the frame of the work implement 17 by a reference lower link 28c (not shown). The tip of the lift arm 27 of the transmission case 18 is connected to the lower lifting link 28b by a top link 28a equipped with a leveling control hydraulic cylinder 28c, so that the work implement 17 is controlled to be level from side to side. The pivotal shaft of the lift arm 27 is provided with a lifting sensor 30 that detects the height of the work implement 17 relative to the tractor 10 by the rotation angle. Incidentally, if a level sensor 35 that detects the horizontal level of the work implement 17 is attached to the reference lower link 28c, fluctuations in inclination are reduced. Furthermore, if the rear end of the reference lower link 28c is attached to the target point 46 of the work implement 17, it serves as a reference for calculating the level of the work implement 17 even if the work implement is replaced.

[0027] By displaying a bar on the altitude display monitor provided on the meter panel 22, with the midpoint representing the altitude of the work implement 17, and if the value is higher than that, the area above the midpoint line is filled in by that value, and if the value is lower, the area below the midpoint line is filled in by that value, it is possible to visually grasp the height of the work implement 17, and even if automatic control is turned off, it becomes possible to manually control the altitude of the work implement.

[0028] Figure 5 is an exploded perspective view showing the connection of the steering handle 16 to the operation mechanism. The steering handle 16 is connected from above to the orbit roll 43 via a universal joint 40, a steering motor 41, and a gear box 42 on the outside of the operation box case 13a, which is inside the cabin 12. This means that the knees of the operator sitting in the cockpit 20 are inside the operation box case 13a, and movement of the legs is not restricted.

[0029] In agricultural tractors equipped with a steering motor, if a solenoid or electromagnetic clutch is used to connect or disconnect the motor and steering, the operating load when manually operating the steering wheel will be lighter.

[0030] Furthermore, if an electrostatic sensor is installed on the handle and the solenoid or electromagnetic clutch is turned on and off depending on whether or not the handle is touched, it becomes possible to control the operation so that it is manual when the handle is held and automatic when the hands are released from the handle. In an emergency, gripping the handle will cut off power from the motor, thereby increasing safety.

[0031] In a tractor with straight-line assist, if a static electricity sensor is mounted on the handle and if static electricity is detected, the steering will be automatically turned off, if static electricity is not detected but the conditions for automatic steering are met, the automatic steering will be turned on, and if static electricity is not detected but the conditions for starting steering are not met, a warning sound will be sounded, making operation easier for the driver.

[0032] As described above, if the conditions for starting automatic steering are displayed on a monitor such as an instrument panel using an icon, color, or text to indicate whether or not the conditions for starting automatic steering are met, the driver will be informed that automatic steering is possible, and the driver will be less likely to take their hands off the steering wheel when automatic steering is not possible.

[0033] In addition, if a vibration motor is installed in the steering wheel, the steering wheel will vibrate when the conditions for automatic steering are met, informing the user that they can take their hands off the steering wheel. This will let the driver know that automatic steering is possible, and reduce the number of times the driver takes their hands off the steering wheel when automatic steering is not possible. [Explanation of symbols]

[0034] 7 Satellite positioning equipment 10 Agricultural vehicles 17 Work equipment 27 Lift arm 28a Lift Rod 28b Lower lift link 28c standard lower link 31 Altitude calculation means 33 Lifting device

Claims

1. In an agricultural work vehicle (10) having a work implement (17) mounted thereon so that it can be raised and lowered by a lifting device (33), the vehicle altitude of the agricultural work vehicle (10) is measured by a satellite positioning device (7), the difference in altitude between the satellite positioning device (7) and the work implement (17) is calculated by an altitude calculation means (31), the altitude of the work implement (17) is calculated from the vehicle altitude and the difference in altitude between the vehicle altitude and the work implement, and the lifting device (33) is controlled to maintain the work implement (17) at a desired altitude while working.

2. The agricultural work vehicle according to claim 1, characterized in that a lifting device (33) is formed by connecting a lifting lower link (28b), a reference lower link (28c), and the lifting lower link (28b) that connect the body of the agricultural work vehicle (10) and the work implement (17) with a lift rod (28a) that connects the lifting lower link (28b) to a lift arm (27) of the body, and the height difference of the work implement (17) is detected by detecting the rotation angle of the lift arm (27).

3. 3. The agricultural work vehicle according to claim 2, wherein a horizontal sensor (35) for detecting the horizontality of the work implement (17) is provided on the reference lower link (28c).

Images