JPH0211201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tillage depth control device for a tractor that detects the height of a working machine such as a rotary relative to the ground and maintains a constant tillage depth.

Conventionally, plowing depth control devices have controlled plowing depth by using a rear cover that also serves as a leveling plate and is pivotally supported behind the rotary cover as a ground height detector, but due to the unevenness of the field in fields, pastures, etc. When the tractor running surface and the plowing surface are no longer parallel, it is not possible to maintain a constant plowing depth on the left and right sides.

Therefore, the present invention configures at least one of the lift rods to be extendable and retractable using a hydraulic cylinder, and also installs detection bodies consisting of left and right rear covers on the left and right parts of the tilling machine, respectively, which can detect the height of the machine above the ground. By connecting these detection bodies to both ends of a balance bar that is rotatably supported at the center and slidably supported in the front and back direction,
The lift arm is controlled to move up and down to a fixed plowing depth position based on signals based on the detected amounts of both the left and right detectors, and the hydraulic cylinder of the lift rod is controlled to expand and contract based on the difference in the detected amounts of both the left and right detectors. It is an object of the present invention to provide a plowing depth control device for a tractor that eliminates the above-mentioned drawbacks.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the tractor 1 has a body 3 supported by wheels 2, and at the rear of the body 3 are a top link 6 and left and right lower links that are pivotally supported via a bracket 5. A rotary 9 is attached by 7. Rotary 9 is tilling blade 1
0, rotary cover 11 and the rotary cover 1
Consisting of a rear cover 12 etc. which is pivotally supported by 1,
Power is transmitted to the tiller blade 10 from the machine body 3 via a universal joint 13 and a transmission device such as a chain. In addition, left and right lift arms 14 that are moved up and down by hydraulic cylinders are arranged at the rear of the fuselage 3, and these lift arms 14 are connected to the left and right lower links 7 via lift rods 15, respectively. At least one of them is constituted by a hydraulic cylinder 15a, the length of which can be adjusted.

Further, as shown in FIG. 2, the rear cover 12, which also serves as a ground leveling plate, is divided into three parts: a center cover 12a, a left cover 12l, and a right cover 12r. The left and right arm plates 17l and 17r are arranged at the ends and have a relatively narrow width, and are connected to left and right arm plates 17l and 17r via L-shaped brackets 16, respectively. Further, as shown in FIGS. 3 to 5, the rotary cover 11 has two
Two rods 21, 20 are fixed across these plates 19, 20.
21 are arranged. Also, these rods 21
A slide plate 22 is slidably supported on the slide plate 22, and a mounting plate 23 having a U-shaped cross section is welded to the slide plate 22, and a bar 25 of a predetermined length is attached to the plate 23. It is slidably supported in a scale-like manner by a pin 26 press-fitted into the center of the holder. And the balance bar 25
The left and right arm plates 17l and 17r are connected to both ends of the arm plate 17 through ball pushers 27, respectively.
Depending on the movement of the levers 1 and 17r, the balance bar 25 can slide back and forth along the rod 21 and rotate about the pin 26. Furthermore, a potentiometer 29 is fixed above the mounting plate 23 via a bracket 28, and an input shaft 29a of the meter 29 is connected to the pin 2 by a push bolt 30.
6 in a coaxial manner. Further, a potentiometer 32 is fixed to the rear plate 20 via a bracket 31 with its input shaft 32a lying horizontally, and the input shaft 32a is connected to the arms 33 and 3.
5 to the mounting plate 23.

As shown in FIG. 6, a tilling depth setting device 36 operated by a tilling depth setting lever or dial disposed on the driver's seat and a tilling depth sensor consisting of a potentiometer 32 are both connected to the lift arm 14. It is connected to comparators 37 and 39 for raising and lowering commands. Further, both the left and right plowing depth setter 40 and the left and right plowing depth sensors comprising a potentiometer 29 are connected to comparators 41 and 42 for commanding the extension and contraction of the hydraulic cylinder 15a constituting the lift rod 15. Note that the left and right plowing depth setting device 40 is set to 0 in the case of normal plowing depth control in which tilling is carried out parallel to the ground surface, but it is possible to obtain a plowing depth that is inclined to the ground surface with different plowing depths on the left and right. You can also set it as appropriate if you wish to do so.

Next, the operation based on this embodiment will be explained. When the tractor 1 is traveling on flat ground or the like and the tractor running surface is parallel to the rotary tilling surface, if the tilling blade 10 tills deeper than the set tilling depth,
The rear cover 12 is divided into three parts, that is, the center cover 12a and the left and right covers 12l, 12 are integrated.
r moves upward by the same amount. Then, the left and right arm plates 17l and 17r move by the same amount in the direction of arrow A, and the slide plate 22 moves the balance bar 25 in parallel in the direction of arrow A, and the potentiometer constituting the plowing depth sensor is moved through the arms 35 and 33. meter 3
Rotate 2. As a result, the signal from the plowing depth sensor 32 is compared with the signal from the setting device 36 by the comparator 37, and the switching valve is controlled to control the lift arm 14.
and the rotary 9 is raised to maintain a predetermined plowing depth. Similarly, when the plowing depth by the rotary 9 becomes shallower than the set plowing depth, the rear cover 12 rotates downward as a unit, and the balance bar 25 is moved in parallel in the opposite direction of the arrow via the left and right arm plates 17l and 17r. Then, the plowing depth sensor 32 is rotated in the opposite direction, the lift arm 14 is lowered via the comparator 39, and the rotary 9 is maintained at a predetermined plowing depth.

As shown in FIG. 7, when the tractor running surface C and the tilling surface D of the rotary 9 are not in a parallel relationship due to irregularities in the field, the tilling depth on the left side becomes deeper and the tilling depth on the right side increases. It becomes shallow. Then, the left cover 12l of the rear cover 12 rotates upward, the right cover 12r rotates downward, the left arm plate 17l moves in the direction of arrow A, and the right arm plate 17r moves in the opposite direction of arrow A. do. As a result, the balance bar 25 rotates around the center pin 26 from the neutral position F to the G position shown by the broken line in FIG. . Then, the signal from the left and right plowing depth sensor 29 is compared with the 0 signal from the setting device 40, and the hydraulic cylinder 15a that constitutes the left lift rod 15 is contracted via the comparator 42, and the rotary 9 is moved to the left with respect to the machine body 3. It slopes upward and is kept parallel to the tilling surface D. Similarly, when the tilling surface D is tilted downward to the left with respect to the running surface C, the balance bar 25 rotates to the E position, and the left lift rod hydraulic cylinder is activated based on the signal from the left and right plowing depth sensor 29. 15a is extended. In addition, when controlling the horizontal plowing depth adjustment based on the rotation of the balance bar 25, the plowing depth is also controlled at the same time based on the parallel sliding of the balance bar 25 by the slide plate 22, based on the average value of the amount of movement of the left and right covers 12l, 12r. The rotary 9 is maintained parallel to the tilling surface D and at the set tilling depth.

In the above-mentioned embodiment, the rotation of the balance bar 25 was detected by the potentiometer 29 to control the left and right plowing depth, but as shown by the chain line in FIG.
Left and right limit switch 2 on slide plate 22
9'l and 29'r may be installed, and the rotation of the balance bar 25 may be detected by turning these switches on and off to control the expansion and contraction of the lift rod hydraulic cylinder 15a. In addition, a balance bar 22 is connected to the left and right detectors 12l and 12r for detecting the height of the rotary 9 above the ground.
The connection is not limited to the arm plates 17l, 17r, and may be connected by wire or electrically.

As explained above, according to the present invention, the detection bodies 12l and 12r capable of detecting the ground height of the tillage machine 9 are installed on the left and right parts of the tillage machine 9, respectively, and a signal is generated based on the detection amount of both the left and right detection bodies. The lift arm 14 is raised and lowered to the set plowing depth position by
Since the hydraulic cylinder 15a is configured to expand and contract, the tilling machine 9 can not only control the plowing depth, but also adjust and control the left and right plowing depths to a predetermined setting value. Even when the tractor running surface C and the tilling surface D of the tilling machine are not in a parallel relationship, an appropriate left and right plowing depth can be maintained.

Further, ground height detecting bodies 12l and 12r consisting of left and right rear covers and pins 2 to which these detecting bodies are respectively connected and slidably supported at both ends thereof are provided.
Even with an extremely simple mechanical configuration consisting of a take-up bar 25 that is swingably supported at a lever 6, and an extremely simple control device based on the amount of sliding and rocking of the take-up bar 25, the set plowing depth can be adjusted. It is possible to perform elevation control to the position and adjustment control of the left and right plowing depth, and it is possible to obtain a tillage control device that is easy to maintain, and is reliable and highly reliable.

Furthermore, it is sufficient to replace the rear cover 12, provide a hydraulic cylinder 15a on one side of the lift rod 15, and attach any tillage control device such as a balance bar 25, a swing amount detection means 29, a sliding amount detection means 32, etc. It can also be easily attached to a tractor as an adapter.

[Brief explanation of drawings]

Fig. 1 is an overall side view showing a tractor to which the present invention is applied, Fig. 2 is a perspective view showing its tilling machine, Fig. 3 is a perspective view showing the tilling depth control device, and Fig. 4 is a plan view thereof. , FIG. 5 is a sectional view taken along the line V-V in FIG. 4, FIG. 6 is a circuit diagram for controlling plowing depth, and FIG. 7 is a rear view showing the tractor in a twisted field situation. 1... Tractor, 3... Body, 6... Top spring, 7... Lower link, 9... Tilling machine (rotary), 12... Rear cover, 12l, 12
r...Ground height detector (left and right cover), 14...
Lift arm, 15...Lift rod, 15a...
...Hydraulic cylinder, 22...Slide plate, 2
5... Balance bar, 26... Pin, 29... Rocking amount detection means, 32... Sliding amount detection means.

Claims (1)

[Scope of Claims] 1. A tractor in which a tiller is attached to the rear of the machine body via a top link and left and right lower links, and left and right lift arms capable of lifting and lowering are respectively connected to the lower links via lift rods, A hydraulic cylinder interposed in at least one of the lift rods to extend and retract the lift rod, and left and right rear covers rotatably supporting the left and right parts of a rear cover that covers the rear of the tilling machine, respectively, left and right detectors each detecting the height above the ground at A balance bar connected to each other, a swing amount detection means for detecting the amount of swing of the balance bar about the pin, and a sliding amount detection means for detecting the amount of sliding of the pin supporting the balance bar. A plowing depth control device for a tractor, wherein the hydraulic cylinder of the lint rod is controlled to expand and contract based on the swing amount detection means, and the left and right lift arms are controlled to move up and down based on the sliding amount detection means.