JPH0475508A - Tractor for agricultural use - Google Patents

Abstract

PURPOSE:To enable stable lifting operation by providing a sensitivity-changing means to change the lift-controlling sensitivity to dull side when the angle of a 2nd cover attached to a 1st cover of a rotary tiller is changed to the lowering side and to change the sensitivity to sensitive side when the angle is changed to lifting side. CONSTITUTION:A 1st cover 9 is attached in a state freely tiltable around a horizontal shaft P1 at the rear end of a rotary cover 8 of a rotary tiller 4. The inclination angle of the 1st cover 9 relative to the rotary cover 8 is detected by an angle sensor 11. A 2nd cover 10 is attached to the lower end of the 1st cover 9 in a state freely tiltable in vertical direction. The tilting angle of the 2nd cover 10 relative to the 1st cover 9 is set by an electric cylinder 12. When the angle of the 2nd cover 10 is changed to the lowering side, the lift-controlling sensitivity is operated to the dull side by a sensitivity changing means interlocked with the change of the angle. Conversely, when the angle is changed to the lifting side, the lift-controlling sensitivity of the controlling means is changed to the sensitive side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an agricultural tractor in which a rotary tiller is connected to the rear of a traveling body so as to be operable to raise and lower the tractor.

[Conventional technology]

As for agricultural tractors such as those mentioned above, for example,
As disclosed in Publication No. 80207, a cover that can freely swing up and down and is in contact with the ground is provided at the rear of the rotary tillage device, and a sensor (corresponding to the detection means) that detects the vertical angle of the cover with respect to the rotary tillage device is installed. ). Thereby, the rotary tiller is operated up and down so that the vertical angle of the cover is maintained at the set value, and the plowing depth of the rotary tiller is maintained at the set value.

[Problem to be solved by the invention]

In the above structure, for example, if the tilling depth of the rotary tiller is set to be shallow, the position of the rotary tiller will be higher than the ground, so the cover at the rear of the rotary tiller will hang down and take a nearly vertical posture. Therefore, in this state, even if the rotary tiller moves up and down slightly relative to the ground, the angle of the cover that follows the ground will change significantly.
If the rotary tiller is moved up and down in accordance with this large angle change, a so-called hunting phenomenon will occur.

Conversely, if the tilling depth of the rotary tiller is set to be deep, the position of the rotary tiller will be lowered, so the cover at the rear of the rotary tiller will be lifted up and placed in a nearly horizontal position. Therefore, even if the rotary tiller moves up and down with respect to the ground in this state, the angle change of the cover that follows the contact with the ground will be small, so if the rotary tiller is operated up and down according to this small angle change, the up and down operation will be Accurate lifting and lowering operations are not performed due to delays.

SUMMARY OF THE INVENTION An object of the present invention is to provide an agricultural tractor that uses the above-mentioned cover to raise and lower a rotary tiller, so that stable raising and lowering operations can be performed regardless of the plowing depth.

[Means to solve the problem]

The feature of the present invention is that the agricultural tractor as described above is configured as follows. In other words, the first cover is attached to the rear of the rotary tiller so that it can swing up and down around the horizontal axis, the second cover is attached to the lower end of the first cover so that the angle can be changed and fixed up and down, and the rotary tiller A detection means for detecting the angle of the first cover with respect to the tilling device, and a control means for raising and lowering the rotary tilling device so that the angle of the first cover is maintained at a set value, and the second cover is When the angle is changed to the downward side, the sensitivity of the elevation control of the control means is operated to the insensitive side, and conversely, when the angle of the second cover is changed to the upward side, the sensitivity of the elevation control of the control means is operated to the sensitive side. The function and effect of the sensitivity change means are as follows.

[For production]

With the above configuration, if the plowing depth is shallow, the second cover (lO) is lowered, for example, as shown by the solid line in FIG. As a result, the second cover (10) touches the ground, the first cover (9) appears to be longer, and the first cover (9) changes from a nearly vertical hanging position to an oblique position. Therefore, the angle change of the first cover (9) when the rotary tiller (4) moves up and down is smaller than when it is in a nearly vertical hanging position.

Coupled with the fact that the lift control sensitivity of the rotary tiller is also operated to the insensitive side, the rotary tiller is smoothly operated up and down without being significantly moved up and down.

Conversely, if the plowing depth is deep, the second cover (10) is raised, for example, as shown by the two-dot chain line in FIG. As a result, the first cover (9) comes into contact with the ground, and the first cover (9) appears to be shorter than in the above-mentioned state.
Since the cover (9) changes from a nearly horizontal position to an oblique position, the angle change of the first cover (9) when the rotary tiller (4) moves up and down becomes larger than when it is in a nearly horizontal position.

Coupled with the fact that the sensitivity of the lift control of the rotary tiller is also operated to the sensitive side, the a-tary tiller is operated sensitively up and down as the plowing depth changes.

〔Effect of the invention〕

As described above, even if the tilling depth setting is changed, the hunting phenomenon and control delay are reduced, and the rotary tiller can be operated stably and accurately.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figure 1 shows the rear of an agricultural tractor. A pair of left and right lower links (2) are provided at the bottom of the mission case (1), and a top link (3) is provided at the top, forming a three-point link mechanism. A rotary tiller (4) is connected to this three-point linkage mechanism. Mission case (1)
) is a rod (7) extending between the lift arm (6) and lower link (2) connected to this hydraulic cylinder (5).
has been erected. Thereby, by expanding and contracting the hydraulic cylinder (5), the rotary tilling device (4) is raised and lowered.

In the rotary tillage device (4), as shown in Fig. 1, the horizontal axis (P
1) A first cover (9) is attached around the rotary cover (9) so as to be able to freely swing up and down, and an angle sensor (11) detects the vertical angle of the first cover (9) with respect to the rotary cover (8).
(corresponding to the detection means) is provided. 1st cover (9
A second cover (10) is attached to the lower end of the second cover (10) so as to be able to swing vertically, and an electric cylinder (12) for setting the vertical angle of the second cover (10) with respect to the first cover (9) is attached. .

Next, the lifting and lowering operation of the rotary tiller (4) will be explained. As shown in Fig. 2, a working state setting device (13) is provided on the agricultural tractor side, and a first switch (13)
Suppose that you press a) to set "shallow rise". In this case, as shown in Fig. 3, a set value (A1) of a shallow plowing depth (for example, 5 to 8 ann) and a relatively wide dead zone (B1) are set in the control device (not shown). , the second cover (10) is lowered by the electric cylinder (I2) as shown by the solid line in FIG. This allows the second cover (
10) comes to touch the ground, and the first cover (9) is lifted from a nearly vertical hanging position to an oblique position.

After this, based on the detected value from the angle sensor (11),
A control valve (not shown) for the hydraulic cylinder (5) or a control device is operated to move the rotary tiller (4) up and down so that this detected value falls within the dead zone (B1).

Next, it is assumed that the second switch (13b) of the setting device (13) is pressed to set "deep rise". In this case, as shown in FIG. 3, a set value (A2) for a deep plowing depth (for example, 15 an or more) and a relatively narrow dead zone (B2) are set in the control device, and the two-dot chain line in FIG. As shown in , the second cover (10) is raised by the electric cylinder (12). As a result, the first cover (9) comes to touch the ground, and the first cover (9) descends from a nearly horizontal position to an oblique position.

After this, based on the detected value from the angle sensor (11),
The control valve for the hydraulic cylinder (5) is operated by the control device, and the rotary tilling device (4) is raised and lowered so that this detected value falls within the range (B2).

The set value (A3) and dead zone (B, ) in Fig. 3 can be set by pressing the third switch (13C) of the setting device (13) in Fig. 2.
This is a case where "General tillage" is set, which is an intermediate state between "Shallow tillage" and "Deep tillage".

In the above embodiment, the electric cylinder (12) automatically expands and contracts based on the signal from the setting device (13) to set the angle of the second cover (10). The operator may manually set the angle of the second cover (10).

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the agricultural tractor according to the present invention.
The figure is a side view of the rear half of the agricultural tractor and the rotary tillage device, FIG. 2 is a plan view of the tiller setting device, and FIG. 3 is a diagram showing the setting value of the tillage depth and the dead zone. (4)...Rotary tillage device, (9)...
...First cover, (10) ...Second cover, (
11)...Detection means, (P1)...Horizontal axis center.

Claims (1)

[Scope of Claims] An agricultural tractor in which a rotary tilling device (4) is connected to the rear of the traveling machine so as to be operable to raise and lower, the rotary tilling device (4) being movable up and down around the transverse axis (P_1) at the rear of the rotary tilling device (4). a first cover (9) that is swingably attached;
A second cover (10) is attached to the lower end of the first cover (9) so that the angle can be changed and fixed up and down, and a detection means for detecting the angle of the first cover (9) with respect to the rotary tiller (4). (11) and a rotary tiller (4) so that the angle of the first cover (9) is maintained at a set value.
and control means for raising and lowering the second cover (10), and when the angle of the second cover (10) is changed to the lowering side, the sensitivity of the raising and lowering control of the control means is operated to the insensitive side in conjunction with this, and conversely, when the angle of the second cover (10) is changed to the lowering side, the sensitivity of the raising and lowering control of the control means is operated to the insensitive side. 2. An agricultural tractor comprising a sensitivity changing means for controlling the sensitivity of the elevation control of the control means to a sensitive side when the angle of the cover (10) is changed to the rising side.