JPH028681B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a working vehicle such as a tractor, and more specifically, it proposes a working vehicle that automatically raises a working machine when moving around in a field.

In agricultural work using a tractor with a working machine attached to the rear, such as rotary tillage, it is necessary to raise the rotary when moving around a headland. In this case, it is necessary to operate the operating levers in sequence to rotate the machine and raise and lower the rotary, and there is a risk of erroneous operation for some reason, which could damage the work equipment or cause the machine to fall. There was a problem that there was a risk of this happening.

The present invention has been made in view of the above circumstances, and uses an optical sensor arranged to detect the presence or absence of cultivated land on the side of the aircraft body to determine one end where work such as plowing should be started and the other end where work such as plowing should be completed. The purpose of the present invention is to provide a work vehicle that improves operability and convenience when moving around by detecting and automatically lowering and raising the work equipment based on the detection results.
The present invention will be explained in detail below based on drawings showing embodiments thereof.

FIG. 1 is an external view of a tractor according to the present invention, and FIG.
The figure is a plan view of the machine of the present invention, and FIG. 3 is a schematic diagram of the automatic elevation control device for the working machine. In the figure, reference numeral 50 denotes a rotary attached to the rear of tractor A as a working machine, and the top arm 51 and lower arms 52, 52 of the rotary 50 are connected to one top link 21 and one lower link 22, 22 on the left and right sides, respectively. Furthermore, the PTO shaft 23 of the tractor A and the drive shaft 53 of the rotary 50 are interlocked and connected by a universal joint 54.

The rotary 50 is raised by actuation of a hydraulic cylinder 23 disposed at the rear of the machine body, and lowered by deactivation of the hydraulic cylinder 23. That is, lower links 22,2
2 is interlocked and connected to a piston rod (not shown) of the hydraulic cylinder 23 via lift links 24, 24, etc., and when pressurized oil is supplied to the hydraulic cylinder 23 and operated as described later, the lower link 2
2, 22 are indexed upwards, resulting in rotary 5
0 is raised, and when pressure oil is not supplied to the hydraulic pump 23, the rotary 50 is designed to descend by its own weight to a position where it is regulated by the field surface.

1l and 1r are optical sensors;
They are arranged to be located on the left and right outer sides of the upper parts of the rear wheels 20, 20, respectively. That is, the pivot shafts 10, 1 are installed upright on the fenders 201, 201 of the rear wheels 20, 20.
The left side with its base end attached so that it can rotate horizontally around 0.
Optical sensors 1l and 1r are attached to the ends of the right arms 11l and 11r using ball joints so that the detection direction can be adjusted. When the tractor A is working, the arms 11l and 11r are fixed by stoppers or the like with their tips extending horizontally to the left and right sides of the rear wheels 20 and 20, respectively, as shown by solid lines in FIG. When the work is finished or when driving on the road, the device is rotated rearward as shown by the two-dot chain line and fixed to a stopper or the like and stored.

The left and right optical sensors 1l and 1r are for detecting the presence or absence of cultivated land CTDs located on the left and right sides of the aircraft, respectively, and are equipped with an infrared light emitting element and a light receiving element, and are used to detect the presence or absence of cultivated land CTD located on the left and right sides of the aircraft, respectively. It consists of an optical sensor that projects infrared rays onto a test object, captures the reflected infrared rays from the test object, converts them into electrical signals, and outputs them. In addition, optical sensor 1
l and 1r are the centers of their respective detection areas, that is, the detection direction is the field surface several 10 cm outward from the left and right sides of the rear wheels 20 and 20, respectively, with the arms 11l and 11r extended as described above. It is set so that it faces
The detection direction relative to the machine body in the longitudinal direction is determined by taking into account the plowing speed, the descending speed and ascending speed of the rotary 50, etc., but the detection direction may be approximately directly below. And cultivated land CTD
is on the left side of the aircraft, the left optical sensor 1
When the cultivated field CTD is located on the right side of the aircraft body, the right optical sensor 1r is used by switching between analog switches 9l and 9r using a select switch 5, which will be described later. That is, in the former case, turn on analog switch 9l and turn on analog switch 9r.
In the latter case, the analog switch 9l is turned off and the analog switch 9r is turned on, so that the output signal of the optical sensor 1l or 1r is selectively applied to the comparison circuit 30.

Figures 3 and 4 show a state in which the cultivated land CTD is located on the right side of the aircraft, and the uncultivated land UCT adjacent to the left side of the cultivated land CTD is being cultivated. Like, select switch 5
The analog switch 9l is turned off and the analog switch 9r is turned on.

Therefore, the normal growth condition of grass on uncultivated land UCT, unevenness,
Although there are differences depending on the degree of wetness, uncultivated land UCT generally has a higher reflectance than cultivated land CTD, so the amount of light received by the optical sensor 1r (or 1l), in other words, the output electrical signal Qr (or Ql) will be lower than that of uncultivated land UCT. When the detection target is CTD of cultivated land, the level is high as shown in FIG. 5A, and on the other hand, when the cultivated land CTD is the detection target, the level is low as shown in FIG. 5A. The output electrical signal Qr (or Ql) of the optical sensor 1r (or 1l) is input to the comparison circuit 30 via the analog switch 9r (or 9l), and the output electrical signal Qr (or Ql) is input to the comparison circuit 30 in advance. If it is lower than the set comparison reference potential Es (the intermediate value between the typical level of the output electrical signal Qr or Ql when detecting uncultivated land and the typical level when detecting cultivated land is selected), that is, the right side of the aircraft Already cultivated land on the left side (or left side)
If CTD is present and detected,
The output P of the comparator circuit 30 is set to the "L" level as shown in FIG.
When the UCT exists and is detected, the output P of the comparator circuit 30 is “H” as shown in FIG.
level. That is, the comparison circuit 30 binarizes the detection output of the optical sensor 1r or 1l into an "H" level or an "L" level depending on whether the field is uncultivated or cultivated. Note that an amplifier circuit may be provided at a stage before the comparison circuit 30.

The output P of the comparison circuit 30 is the solenoid control circuit 3
1. Specifically, it is provided in the pressure oil supply path to the hydraulic cylinder 23 and allows the piston rod to advance;
It is applied to a solenoid drive circuit of an electromagnetic directional control valve for switching oil passages for retracting or stopping. This solenoid control circuit 31 is a comparison circuit 3.
While the output P of 0 is at the "H" level as described above, the hydraulic cylinder 23 is activated to raise the rotary 50.
Supply pressure oil to the “L” level,
The electromagnetic directional control valve is controlled to change the oil passage ratio so as to release the pressure oil from the hydraulic cylinder 23. Note that the supply of pressure oil to the hydraulic cylinder 23 is also performed by manually operating a lever 5 for lifting and lowering the working machine disposed near the driver's seat DS.

When rotary tilling is performed using the machine of the present invention configured as described above, the first step is to move the rotary 50, which has been raised in advance, to the work machine lift lever without relying on the automatic lift control device of the work machine. Manually operate 5 to lower the cultivated land parallel to the ridge.
Tractor A is driven to perform plowing work so as to form a CTD. Then, when completing one stroke of plowing and moving around the headland, the automatic lifting control device of the working machine is started. In this case, in the next step, the cultivated land CTD is located on the right side of the machine body, so the select switch 5 turns off the analog switch 9l and turns on the analog switch 9r to activate the right optical sensor 1r. Therefore, while the detection area of the optical sensor 1r is on a field that does not require cultivation such as a headland, that is, on uncultivated land UCT, its output signal Qr is at a high level as shown in Fig. 5A. Since the output of the comparator circuit 30 is also at the "H" level, the rotary 50 remains in the raised and retracted state, as understood from the foregoing.

Next, the aircraft is rotated and CTD of the cultivated land is carried out as mentioned above.
When the uncultivated land CTD is entered into the uncultivated land UCT from one end where cultivation should start in the manner shown by the dashed line in Fig. 4, the cultivated land CTD enters into the detection area of the optical sensor 1r. , the output signal Qr changes from high level to low level as shown in Figure 5A,
Therefore, the output P of the comparator circuit 30 also changes from the "H" level to the "L" level, and as a result, as understood from the above, the rotary 50 is automatically lowered and the rotary plowing by the tractor A is resumed. Ru. Then, when the tractor A reaches the position shown by the two-dot chain line in Fig. 4, that is, near the other headland where plowing should be completed, the detection area of the optical sensor 1r reaches the already cultivated land CTD formed in the previous step. When exiting from the longitudinal end of the uncultivated land UCT, the output signal Qr
As shown in Figure A, the level changes from low to high, so the rotary 50 is automatically raised. After the manual operation, the new cultivated land CTD' will be located on the left side of the aircraft, so the analog switch 9l is turned on and the analog switch 9r is turned off using the select switch 5, and the optical sensor on the left side is turned on. When 1l is activated, the rotary 50 is automatically lowered at one end where tilling should start, and the rotary 50 is automatically raised at the other end where tilling should be finished, in the same way as described above. Then, the rotary plowing by the tractor A continues, and in the above operation, the optical sensors 1r and 1
l is located at the rear of the aircraft, so it can be used on uncultivated land.
The distance between the machine traveling position where the UCT is detected by the optical sensors 1r and 1l and the position where the rotary 50 is raised and no longer tilling is performed is short, and therefore the distance between the position of the longitudinal end of the cultivated land, i.e. The edges of the headland will be aligned, allowing for orderly work.

Since the optical sensors 1r and 1l are installed on the machine body, there is less vibration compared to when they are installed on the work machine.
It is possible to stably detect cultivated land and uncultivated land. 6th
The figure is a partial rear view schematically showing another embodiment of the tractor according to the present invention. In this embodiment, instead of the arms 11l and 11r used in the above embodiment, a vertical shaft 10' is provided upright on the fender 201.
It uses a support 11'r that is attached to the body and can be extended and retracted toward the outside of the fuselage. . The support 11'r is a series of pantograph-like links, and an optical sensor 1r is attached to the tip of the support 11'r so that its attachment angle can be adjusted. The supports 11'l, 11'r are
When in use, extend it as shown by the solid line in Figure 6,
The rear wheels 20, 20 are fixed horizontally on the left and right outer sides thereof by appropriate means, and when not in use, they are retracted as shown by the two-dot chain line, fixed by appropriate means, and stored away. It is set as.

As described above, the work vehicle according to the present invention is a work vehicle equipped with a work machine that can be raised and lowered at the rear, and is equipped with an optical system that captures reflected light from a detection target and outputs an electrical signal according to the level of the reflected light. A sensor is disposed near the extension line of the center of the rear wheels in plan view to detect the presence or absence of cultivated land on the rear side of the machine body, and when the output of the optical sensor indicates the absence of cultivated land, the working machine is raised. For example, when the rotary plowing is carried out by a tractor, as long as the machine is traveling along the cultivated land, the rotary is automatically raised and lowered, allowing the driver to make the rounds. Only the operation is required, and the operation is simplified, which improves operability and convenience, reduces the driver's labor burden, and prevents damage to the work machine and overturning of the machine. In addition, in the case of a structure in which the work equipment is raised and lowered depending on the presence or absence of cultivated land as in the present invention, in the case of a work vehicle equipped with an automatic steering device, the rotation sequence is started in accordance with the rise of the work equipment. In addition, it becomes possible to enter the automatic steering sequence for operating the work machine again as the work machine descends. In this type of work vehicle, the boundary between cultivated and uncultivated land is often used as a reference point for automatic steering, but the work machine is lowered when the optical sensor detects the presence of cultivated land. There is an advantage that steering is started in a stable state. Further, according to the present invention, the edges of the headland are automatically aligned without providing special facilities in the field, allowing for orderly work. Furthermore, if the construction is such that the power transmission to the PTO shaft is cut off and the rotation of the rotary is stopped when the work equipment is raised, safety is further increased. Since the optical sensor is placed near the extension line of the center of the rear wheel in plan view, even when plowing in a meandering state, the tractor, etc. changes its direction around the rear wheels, so it is possible to move the Since cultivated land is detected in a small number of positions, for example, a tractor equipped with an automatic steering device can detect the boundary line between uncultivated land and cultivated land. It can also be used as a sensor.

In addition, in the above-mentioned embodiment, the lowering of the rotary 50,
The signals from the optical sensors 1l and 1r necessary for controlling the ascent are taken in and used by switching the analog switches 9l and 9r, respectively, using the select switch 5. However, the present invention is not limited to this. Process each signal of 1l and 1r simultaneously,
For example, it is of course possible to control the lowering and raising of the rotary 50 depending on the magnitude of the potential difference between the respective output signals.

Further, in the embodiment described above, the optical sensors 1l, 1
Although it was decided to use an infrared light-emitting element and a light-receiving element built-in for r, the present invention is not limited to this.
Of course, it is also possible to use an optical sensor that includes a built-in light-receiving element that captures sunlight or field illumination light reflected from the test object, converts it into an electrical signal, and outputs it.

[Brief explanation of drawings]

The drawings show examples of the present invention, in which Fig. 1 is an external view of the inventive machine, Fig. 2 is a plan view thereof,
Fig. 3 is a schematic diagram of the automatic lift control device, Fig. 4 is an explanatory diagram of the operation of the machine of the present invention, Fig. 5 is a timing chart for explaining the operation of the main parts of the machine of the present invention, and Fig. 6 is a diagram of the optical sensor. FIG. 7 is a partial rear view schematically showing another embodiment in an attached state. 1l, 1r...Optical sensor, 5...Select switch, 9l, 9r...Analog switch, 1
0, 10... Pivot shaft, 11l, 11r... Arm, 20, 20... Rear wheel, 201, 201... Fender, 23... Hydraulic cylinder, 30... Comparison circuit, 31... Solenoid control circuit, 11'r...
Support.

Claims (1)

[Claims] 1 In a work vehicle equipped with a work equipment that can be raised and lowered at the rear, an optical sensor that captures the reflected light from the detection target and outputs an electrical signal according to the level of the reflected light is installed on the cultivated land on the side of the rear of the vehicle. A working vehicle characterized in that the optical sensor is arranged near an extension line of the rear wheel center in a plan view to detect the presence or absence of cultivated land, and is configured to raise a working machine when the output of the optical sensor indicates that there is no cultivated land.