JP3773646B2 - Tractor depth control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for preventing hunting in a case where a rotary tiller is attached to a rear portion of a tractor via an elevating mechanism and the tilling depth is controlled using a rear cover of the rotary tiller as a sensor.
[0002]
[Prior art]
Conventionally, a rotary tiller is mounted on the lifting mechanism at the rear of the tractor, a rear cover is pivotally supported at the rear of the tiller cover, and a rod that moves back and forth is provided along with the rear cover, and pushed to the end of the rod. Tighten one end of the pull wire, connect the other end of the push-pull wire to the rear cover sensor located at the rear of the tractor, detect the amount of rotation of the rear cover, and control the lifting means by the controller such as controller Had gone.
[0003]
An elastic coupling member such as rubber is disposed on the pivotal support portion of the rear cover, and the rear cover is urged so as not to be swung by a small unevenness in a farm scene so that the small swing is not transmitted to the rear cover sensor. .
[0004]
Further, in the controller, a dead zone is provided so that the lifting / lowering operation is not performed when the rear cover swings slightly. The width of the dead zone is configured to be changeable. When hunting is likely to occur, the width of the dead zone is widened to suppress hunting.
[0005]
[Problems to be solved by the invention]
However, in the technology that prevents the rear cover from rotating with respect to small irregularities by using an elastic connecting member, in the tractor that enables high-speed tillage, the elastic connecting member allows the rear cover to be swung slightly. Cannot be sufficiently absorbed, and is transmitted to the rear cover sensor as vibration in a high frequency range, hunting occurs in the lifting means, and the control performance is degraded.
[0006]
Moreover, when the dead zone was increased, the tilling depth control performance was lowered and the depth of the tilled soil was varied.
[0007]
[Means for Solving the Problems]
In order to eliminate such problems, the present invention is configured as follows.
In the configuration in which the rotary tiller 10 is mounted to the rear of the tractor so as to be movable up and down, the tilling depth is detected by the rear cover 7 of the rotary tiller 10, and the tilling control is performed by raising and lowering the rotary tiller 10. A feedback link 23 is pivotally supported, and the other end of the feedback wire 22 connected to the rear cover 7 is connected to the feedback link 23, and one end of a connection link 24 is pivotally supported in the middle of the feedback link 23. The other end of the link 24 is pivotally supported by a sensing arm 18a of the rear cover sensor 18 via a spring 26. Further, a damper 25 as a buffer member supported on the tractor side is connected to the tip of the sensing arm 18a, A throttle valve 30 is interposed in the hydraulic circuit of the damper 25 to match the hardness of rice stocks and cultivated soil in the field. Adjust the narrowed Riben 30 Te is a force to dampen the expansion and contraction speed of the damper 25 obtained by adjustable.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The problems to be solved by the present invention and the means for solving the problems are as described above. Next, the configuration of the embodiment shown in the accompanying drawings will be described.
FIG. 1 is a side view of a tractor equipped with a rotary tiller that performs plowing depth control, FIG. 2 is a side view of a means for detecting plowing depth having a buffer member of the present invention, and FIG. FIG. 4 is a block diagram of the tilling depth control, and FIG.
[0009]
In FIG. 1, a lifting link mechanism 1 including an upper link and a lower link is attached to the rear part of the tractor, and a rotary tiller 10 is mounted on the lifting link mechanism 1. In the lift link mechanism 1, the lift arm 9 is lifted and lowered by the lift cylinder 6, and the rotary tiller 10 is lifted and lowered. A lift angle sensor 14 composed of a potentiometer or the like is disposed at the rotation base of the lift arm 9. The height of the rotary tiller 10 is detected from the angle of the lift arm 9, and the lift angle sensor 14 is located below the seat 11. It is connected to the arranged controller 5.
[0010]
An elevating operation lever 12 is arranged on the side of the seat 11 of the tractor, and a sensor (not shown) composed of a potentiometer or the like for detecting the operation position is arranged at the base of the elevating operation lever 12. The sensor detects the operating position of the elevating operation lever 12 and drives the electromagnetic solenoid of the elevating cylinder 6 to rotate the lift arm 9 so that the rotary tiller 10 reaches the set height.
[0011]
Further, a control box is disposed on the side portion of the seat 11, and a plowing depth setting dial 15 and an automatic plowing depth mode switch 16 are disposed in the control box, and the plowing depth setting dial 15 and the automatic plowing depth mode are arranged. The switch 16 is connected to the controller 5 to set the working depth in the automatic control mode.
[0012]
Further, a tillage cover 8 is disposed on the upper part of the rotation trajectory of the tillage claw of the rotary tiller 10, and a rear cover 7 is pivotally supported on the rear part of the tillage cover 8. A support plate 21 is fixed to the tillage cover 8 via a bracket (not shown), and a slide rod 20 is supported on the support plate 21 so as to be slidable forward and backward. Are pivotally connected to the rear cover 7, and the sliding rod 20 slides as the rear cover 7 rotates. A feedback wire 22 is connected to the other end of the sliding rod 20, and the feedback wire 22 is pushed and pulled inside the outer case, and the rotation of the rear cover 7 is transmitted to the rear cover sensor 18 including a potentiometer disposed at the rear of the tractor. And the tilling depth transmission means is formed.
[0013]
Further, the rear cover sensor 18 is connected to the controller 5, and as shown in FIG. 3, the plowing depth setting (target) value set by the plowing depth setting dial 15 is input to the controller 5. Further, the value detected by the rear cover sensor 18 is fed back to the controller 5 and compared with the working depth setting value. For example, when the actual working depth is shallower than the working depth setting value, the lift arm 9 is lowered and rotated. The tilling depth setting value and the detection value from the rear cover sensor 18 are lowered.
[0014]
In the present invention, as shown in FIG. 2, a feedback link 23 is pivotally supported at the rear of the tractor body, and the other end of the feedback wire 22 is connected to the feedback link 23.
[0015]
One end of a connection link 24 is pivotally supported in the middle of the feedback link 23, and the other end of the connection ring 24 is pivotally supported by a sensing arm 18 a of the rear cover sensor 18 via a spring 26.
Furthermore, a damper 25 as a buffer member supported on the tractor side is connected to the tip of the sensing arm 18a.
[0016]
In such a configuration, when the rotary plowing device 10 plows a field having a continuous uneven surface, such as a rice plant, at high speed, the rear cover 7 repeats small up and down swings to generate a so-called high-frequency vibration. This high-frequency vibration is transmitted to the feedback link 23 via the feedback wire 22, and a coil spring 26 is interposed between the feedback link 23 and the sensing arm 18a, and between the sensing arm 18a and the fuselage. Since the damper 25 is interposed, the high frequency component is buffered by the coil spring 26 and the damper 25, and only the low frequency component necessary for control is transmitted to the sensing arm 18a.
[0017]
That is, high frequency vibrations that cause hunting cannot be transmitted to the rear cover sensor 18, only the low frequency range of the rear cover 7 is transmitted to the rear cover sensor 18, and the amount of rotation of the rear cover is fed back to the controller 5 to cause hunting. Without plowing control.
[0018]
In addition, by adjusting the throttle valve 30 in the hydraulic circuit in the damper 25, the expansion / contraction operation speed of the damper 25 and the buffering force can be adjusted, and the hardness of the rice stock and the soil in the field can be adjusted. The vibrations caused by the disturbance caused by the earth lump or the rice plant that works on the rear cover 7 can be effectively reduced.
[0019]
Next, another configuration for preventing hunting will be described.
As shown in FIG. 3, the rotation change of the rear cover 7 is transmitted to the rear cover sensor 18 without providing a damper, and the output of the rear cover sensor 18 is fed back to the controller 5 via a low-pass filter 28. However, the high frequency can be cut by software.
[0020]
The low-pass filter 28 has the frequency characteristics shown in FIG. 4, the output is substantially zero in a high frequency range above a certain frequency (cut-off frequency fc), and the input signal is passed as it is at a frequency below the cut-off frequency fc. I try to let them. This cut-off frequency fc (Hz) is changed according to the traveling speed of the tractor and is obtained by the formula fc = v / L, where v is the vehicle speed (m / s) and L is the reference length (m). . L is the distance from the rotary tiller 10 to the contact surface of the rear cover 7.
The vehicle speed v for calculating the cutoff frequency fc is detected by a speed sensor 29 (in this embodiment, disposed on the axle and input to the controller 5 as shown in FIG. 1). Further, the cut-off frequency fc is changed at any time to a value proportional to the traveling speed.
[0021]
When configured in this way and a field having small irregularities is cultivated at high speed by the rotary cultivator 10, vibration in the high frequency region is generated in the rear cover 7 and detected by the rear cover sensor 18, but the signal is detected by the low-pass filter 28. The high frequency component is cut and input to the controller 5, and hunting does not occur.
Therefore, the calculation process in the controller 5 is smoothly calculated without being affected by disturbance, and the tilling depth control is performed accurately at the time of high speed tillage, the finishing after tilling can be improved, and the rice planting by the rice transplanter can be performed in the finished field. Even if the work is done, the rice transplanter goes straight forward, the planted seedlings are in good posture, and can be planted without any stock.
[0022]
【The invention's effect】
Since it comprised as mentioned above, this invention has the following effects.
In the configuration in which the rotary tiller 10 is mounted to the rear of the tractor so as to be movable up and down, the tilling depth is detected by the rear cover 7 of the rotary tiller 10, and the tilling control is performed by raising and lowering the rotary tiller 10. A feedback link 23 is pivotally supported, and the other end of the feedback wire 22 connected to the rear cover 7 is connected to the feedback link 23, and one end of a connection link 24 is pivotally supported in the middle of the feedback link 23. The other end of the link 24 is pivotally supported by a sensing arm 18a of the rear cover sensor 18 via a spring 26. Further, a damper 25 as a buffer member supported on the tractor side is connected to the tip of the sensing arm 18a, A throttle valve 30 is interposed in the hydraulic circuit of the damper 25 to match the hardness of rice stocks and cultivated soil in the field. Adjusting the narrowed Riben 30 Te and, since the force to dampen the expansion and contraction speed of the damper 25 to be adjusted, buffered with a buffer member without transferring vibrations of a high frequency band would cause hunting in the sensing arm Absorbing and cultivating depth can be controlled with high accuracy without causing hunting.
[0023]
In addition, since the buffering force of the buffer member can be adjusted, it can be adjusted according to the disturbance due to the soil block or rice stock, the vibration due to the disturbance can be effectively reduced, and the tilling depth is kept constant, The finish after tillage is greatly improved.
[Brief description of the drawings]
FIG. 1 is a side view of a tractor equipped with a rotary tiller that performs plowing depth control.
FIG. 2 is a side view of a means for detecting a tilling depth having the buffer member of the present invention.
FIG. 3 is a block diagram of tilling control having the low-pass filter of the present invention.
FIG. 4 is a diagram illustrating a characteristic of a cutoff frequency of a low-pass filter.
[Explanation of symbols]
10 Rotary tiller 18 Rear cover sensor (plowing depth detection means)
18a Sensing arm 25 Damper (buffer member)
26 Coil spring (elastic body)
28 Low-pass filter fc Cut-off frequency

Claims (1)

In the configuration in which the rotary tiller 10 is mounted on the rear portion of the tractor so as to freely move up and down, the tilling depth is detected by the rear cover 7 of the rotary tiller 10, and the tilling control is performed by raising and lowering the rotary tiller 10.
A feedback link 23 is pivotally supported at the rear part of the tractor body, the other end of the feedback wire 22 connected to the rear cover 7 is connected to the feedback link 23, and one end of the connection link 24 is pivoted to the middle part of the feedback link 23. And pivotally supported on the sensing arm 18a of the rear cover sensor 18 via the spring 26 at the other end of the connecting link 24.
Further, a damper 25 as a buffer member supported on the tractor side is connected to the tip of the sensing arm 18a, and a throttle valve 30 is interposed in the hydraulic circuit of the damper 25 so that rice stocks and cultivated soil in the field can be obtained. A tractor plowing depth control device , wherein the throttle valve 30 is adjusted in accordance with the hardness of the tractor so that the expansion / contraction speed of the damper 25 and the buffering force can be adjusted .

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