JPH0611204B2 - Working depth control device for ground work equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an automatic tilling depth control means for controlling elevation so as to maintain a relative distance between a ground work device and a rear ground of the ground work device at a target set value. The present invention relates to a working depth control device for a ground working device provided with a forced raising means for forcibly raising the ground working device in preference to the control by the automatic working depth control means.

[Conventional technology]

For example, considering plowing work using a rotary tiller, when plowing a field using a rotary tiller, in order to maintain a constant tilling depth of the rotary tiller,
Activate the automatic tilling depth control means as described above. Further, when a vehicle body such as a tractor equipped with the rotary tilling device reaches a headland during the work for plowing the field in this way, the forcible raising means as described above is operated to turn the vehicle body so as to rotate the rotary body. Raising the tiller (no references listed).

[Problems to be solved by the invention]

Here, consider the case where the rotary tiller, which has been raised by the operation of the forcible raising means as described above, is lowered after turning of the vehicle body. This lowering operation is performed by stopping the operation of the forcible raising means. , When the operation of the forcible raising means is stopped in this way, the rotary tiller moves toward the direction in which the relative distance between the uncultivated ground and the rotary tiller is maintained at the target set value. Since the operation is started, the tillage depth with respect to the untilled ground becomes deeper than the tillage depth before turning of the vehicle body, and the engine may be overloaded.

In other words, when plowing the field using the rotary tiller, the automatic plowing depth control is performed based on the field scene that rises due to plowing, so the automatic plowing depth on the untilled ground is used. When the control is started, the plow depth becomes deeper if the target value before turning of the vehicle body is maintained.

Therefore, as described above, when the automatic tillage depth control is started on the non-tilled ground, the control target of the automatic tillage depth control means is set to be shallower than the original tillage depth, and this tilling work proceeds. It is possible to return the control target to the original plowing depth at the time when control based on the ground raised by plowing becomes possible, but there is a difference between the original plowing depth and the shallow plowing depth. When the difference is large, it is also conceivable that the fluctuation of the plowing depth at the time when the control target is returned to the original plowing depth is abruptly changed, which causes the plowing ground to be rough.

An object of the present invention is to perform control by bringing the tilling depth close to the original tilling depth at the start of the automatic tilling depth control on the unplowed ground, as in the case of restarting the automatic tilling depth control at the headland. Even if there is a large difference in the target working depth when the actual working depth is switched from the control to the original control, the working depth control device does not suddenly change. .

[Means for solving problems]

A feature of the present invention is that in the plowing depth control device for a ground working device described at the beginning, a control target of the automatic plowing depth controlling device until the predetermined condition is satisfied from the descent of the ground working device due to the release of the control of the forcible raising means. Is a correction means for correcting to a correction value shallower than the target set value, and the plowing depth value of the ground work device at the time when the predetermined condition is satisfied, a difference of a predetermined value or more with respect to the target set value. In the case where it occurs, there is provided a slow-returning means for performing a raising / lowering operation for bringing the working depth of the ground work device close to the target set value at a low speed, and its action and effect are as follows.

[Action]

When the ground work device is lifted by the forcible lifting means to turn the headland, and then the operation of the forcible lifting means is canceled to lower the ground working device in order to restart the work, the correction means causes the automatic plowing depth to increase. The control target in the control is corrected to a value (correction value) that is shallower than the target setting value, so it prevents the depth of plowing that is deeper than the set value at the start of work when there is no rising soil due to plowing. If the predetermined condition is satisfied (for example, the set time has elapsed), swelling soil due to plowing will be generated, so the control target is returned to the original set value. When there is a difference between the plowing depth in the correction state and the set value by a predetermined value or more, the ground work device is gradually moved up and down toward the original set value.

〔The invention's effect〕

Therefore, even when the plowing work is restarted on the headland, the plowing depth can be brought close to the original plowing depth, so that the load on the engine is not increased and the plowing depth becomes too deep with respect to the set value. Even if there is a large difference between the actual working depth and the target working depth at the time of switching to the original set working depth, the plowing ground will be roughened because the changing of the working depth is performed at a low speed. A plowing depth control device with few problems was obtained.

〔Example〕

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

As shown in FIG. 4, a lift arm (3) that moves up and down by the operation of a hydraulic cylinder (2) is provided at the rear part of the vehicle body (1) of an agricultural tractor, and a three-point link mechanism that is lifted and lowered by this lift arm (3). A rotary tiller (6) is connected as an example of a ground work device via (4).

As shown in the figure, on the right side of the driver's seat (5) provided in the vehicle body (1), a position lever (7) for arbitrarily setting the level of the rotary tiller (6) against the vehicle body, and a rotary tiller ( 6)
Control box for automatically controlling the working depth
(8), also, in the rotary cultivator (6), in order to measure the relative distance between the rotary cultivator (6) and the rear ground of the rotary cultivator (6), the swing cover (6a) A plowing depth sensor (9) for electrically detecting the swing angle is provided.

As shown in FIG. 1, the control box (8) has a plowing depth setting device (10) operated by a dial (not shown).
Further, each of the rising switches (11) for switching operation is provided on the upper surface of the box, and the tilling depth control device (A) is incorporated.

As shown in the figure, the tilling depth control device (A) is an automatic tilling depth control means (B) forced raising means (C), correction means (D), restraining means (E),
It consists of slow speed recovery means (F), solenoid valve drive circuit (G), timer (H), and these five means (B), (C), (D), (E), (F) and timer ( H) is configured by a program set in a microprocessor (not shown), and is configured to drive and operate the solenoid valve (12) for the hydraulic cylinder (2) according to this program.

The tilling depth control device (A) compares the set tillage depth value (target setting value) set by the tillage depth setter (10) with the signal value from the tillage depth sensor (9), and is a rotary tiller device. Forced to raise the rotary tiller (6) to a set position away from the ground in priority to the automatic tilling depth control mode that raises and lowers (6) and when the raising switch (11) is turned on. It can be switched to the ascending mode, and its operation follows the flowchart shown in FIG.

That is, when the working depth control device (A) starts operating, the set working depth value is input (# 1 step), and the correction value (d) is calculated based on this set working depth value (# 2 step). .

Incidentally, the correction value (d) thus obtained is, as shown in FIG. 4, changed from the tilling depth value (J) based on the rising ground (13) raised by tilling to the untilted ground (14). This value is the same as the value obtained by subtracting the value (K) of the difference from the rising ground (13), and this correction value (d) is set proportionally larger as the working depth is set deeper.

Next, determine the state of the up switch (11) (# 3 step),
If it is in the OFF state, the flag to be described later is determined (# 4 step).

In the tilling depth control device (A), it is turned off in the initial state of control.
Since it is set to the state, the control flow from the # 4 step leads to the automatic working depth control of the # 5 step.

In normal plowing work, the control mode is set to the automatic plowing depth control mode by this # 5 step, and when the raising switch (11) is turned ON in this control mode, the flag is set to the ON state. , Forcibly raise the rotary tiller (6) to the set position (# 6, # 7 steps).

This raising operation is performed when the vehicle body (1) reaches a headland during the plowing work, and when the vehicle body (1) is turned on the headland and the rotary tiller (6) is lowered, the operation shown in FIG. As shown in Fig. 4, while avoiding the phenomenon that the plowing depth becomes deep due to the contact of the rocking cover (6a) with the unplowed ground (14), the rotary plowing (6 The cultivating depth control device (A) operates as follows so that the cultivating depth of) does not become too shallow.

By the way, the control mode performed in step # 7 is the forced rising mode, and in this control mode, when the rising switch (11) is turned OFF, the flag is set to the ON state. Branch to activate the timer (# 8 step).

After the processing of this # 8 step, the control target of the automatic working depth control is changed to the correction value (d) obtained in the # 2 step (# 9 step), and this correction value (d) and the working depth sensor (9 ) Signal value is compared (# 10 step) to determine the control direction (# 11 step).

If the direction of up / down control of the rotary tiller (6) is descending based on this determination, automatic plowing depth control is performed as it is (step # 12). If the direction of up / down control is up, control is not performed and # 8 It is determined whether or not the elapse of the set time (T) has been measured by the timer that started operation in step (# 13 step).

Also, the set time (T) of this # 13 step is about 2 seconds, and the rocking cover (6a) rises when the vehicle body (1) moves forward and the ground (13) is detected during this set time (T). It almost coincides with the timing to do. When the set time (T) is measured in step # 13, the flag is turned off (# 14 step), the timer is turned off (# 15 step), and the set working depth value and working depth sensor (9 ) Is calculated (step # 15), and the difference value obtained by this calculation is compared with a predetermined value (# 1).
7 steps).

If the difference value is less than the specified value in step # 17, the control target is returned to the set working depth value input in step # 1 (step # 18), and the automatic working depth control state in step # 5 is entered. .

When it is determined that the difference value is equal to or larger than the predetermined value in step # 17, the difference value is divided by the set number (N) (step # 1), and the control target is once set to the working depth sensor (9). After replacing with the signal value from, the divided value is added or subtracted until it reaches N times at regular time intervals, and at the same time, the automatic tilling depth control device (6) is slowly returned to the original tilling depth. ing.

It is to be noted that FIG. 1 is a diagram in which the control described above is captured in a block form and the flow of control is diagrammed.

In addition, step # 5 of the flow chart is automatically plowing control means.
(B), # 7 step is forced rising means (C), # 9 step is correction means (D), # 11 and # 12 steps are restraining means (E), # 19 and # 20 steps are slow recovery means ( F) respectively.

[Another embodiment]

In addition to the above-described embodiment, the present invention can be configured, for example, as a hard circuit composed of a logic gate or the like as each means, and the working depth sensor is configured as a non-contact type. As a means for making a determination, instead of a timer, it may be configured to measure that the rotation amount of the wheel has reached a set amount.

Further, as the slow-speed returning means, for example, a variable throttle valve is provided in an oil passage of a hydraulic actuator for raising and lowering the ground work device, and the lowering speed of the ground work device is reduced by adjusting the throttle amount of the variable throttle valve. You can put it out.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a working depth control device for a ground working device according to the present invention, FIG. 1 is a block diagram showing the configuration of the working depth control device, and FIG. 2 is a flowchart showing the operation of the working depth control device. FIG. 3 is a side view showing the state at the start of the plowing work, and FIG. 4 is a side view showing the state of the plowing work. (6) …… Ground work device, (B) …… Automatic tilling depth control means, (C)
...... Forced rise means, (D) …… Correction means, (d) …… Correction value,
(F) …… Slow recovery means.

Claims (2)

[Claims] 1. Automatic plowing depth control means (B) for controlling elevation so that a relative distance between the ground working device (6) and the rear ground of the ground working device (6) is maintained at a target set value, and the automatic plowing. A plowing depth control device for a ground working device provided with a forced raising means (C) for forcibly raising the ground working device (6) in preference to the control by the depth control means (B), said forced raising means Until a predetermined condition is satisfied from the lowering of the ground work device (6) by releasing the control of (C), the control target of the automatic plowing depth control means (B) is set to a correction value (d) shallower than the target set value. Correcting means (D) to correct so that, and the working depth value of the ground work device (6) at the time when the predetermined condition is satisfied, a difference of a predetermined value or more with respect to the target set value In addition, the ground work that is provided with a slow-speed return means (F) that quickly performs a lifting operation to bring the working depth of the ground work device (6) close to the target set value. Location of tilling depth control device. 2. The working depth control device for a ground work apparatus according to claim 1, wherein the slow-moving speed of the ascending / descending returning means (F) is reduced by intermittent driving.