JPS5953001B2 - Tiller with automatic lifting control mechanism - Google Patents

Description

[Detailed Description of the Invention] In recent years, for cultivating machines in which a tilling device is attached to a traveling machine body so that the tilling device can be raised and lowered, two types of automatic raising and lowering of the tilling device have been proposed, as described below. There is.

That is, based on the detection result of the tilling load, automatic elevation control is performed so that the plowing depth approaches the target set plowing depth, or automatic elevation control is performed so that the target height and the actual height of the machine body become zero.

In the case of the former control, even if the amount of sinking of the traveling machine into the ground changes due to changes in the softness of the ground and the actual plowing depth changes, this is detected as a change in the tilling load. Since the lifting and lowering control is performed by controlling the plowing depth, it has the characteristic that it is possible to perform plowing work close to the target plowing depth without being affected by changes in the amount of sinking of the traveling machine into the ground.

In addition, in the case of the latter control, since the tilling device is always supported at a constant height relative to the traveling machine, for example, the ground has a substantially constant hardness, and it is difficult for the traveling machine to sink into the ground. It is effective when the amount is approximately constant.

In other words, if the above-mentioned control is performed based on the tillage load when the ground has approximately constant hardness, the tillage may suddenly change due to local hardness or softness of the ground, regardless of changes in the amount of subsidence of the traveling machine into the ground. Even if the load fluctuates, the tilling equipment will be raised and lowered accordingly, causing the actual ground action depth to vary greatly locally. It is better to maintain the plow at a constant height to obtain a stable plowing depth.

In addition, when cultivating radish, etc., or when cultivating soil near the ground surface and soil in the deep layer, so-called top and bottom soil reversal, etc., the tiller must be operated more fully than in normal tillage operations. It will be located deep underground.

Conventionally, when performing this type of tilling work, the tilling device is automatically raised and lowered based on the above-mentioned tilling load so that it approaches the target plowing depth, and the target plowing depth itself is changed. In this case, the maximum tillage load was increased to the maximum allowable, that is, the maximum plowing depth was obtained while making the most effective use of the engine power. Setting the target plowing depth itself is extremely difficult.

In other words, in the field, the tillage load can vary significantly even at the same plowing depth due to changes in soil quality, soil hardness, etc. Therefore, it is important to accurately understand the field conditions such as soil quality and soil hardness. It is difficult, even for a highly skilled person, to quickly set an appropriate target plowing depth. Therefore, if the target plowing depth is too shallow, it will be difficult to quickly set the appropriate target plowing depth. There is the inconvenience of not being able to obtain a sufficiently deep plowing depth, and conversely, if the plowing depth is too deep, the tilling device will be raised and lowered automatically in a state where an unreasonable tilling load is constantly being applied to the engine power, so the tilling device must be raised and lowered frequently. This method has the disadvantage that it tends to cause a bunching phenomenon in control.

Furthermore, if you try to change the target plowing depth itself, the plowing depth setting device for setting the target plowing depth should include a setting range for obtaining a plowing depth suitable for normal tilling work, and In order to obtain a sufficiently larger plowing depth than the previous plowing depth, it became necessary to have a function that greatly enlarged the range in which the target plowing depth could be set. There is also the disadvantage of having to use .

The technical problem to be solved by the present invention is to solve the problem of control bunching by simply partially improving the control form of the automatic control mechanism that is originally provided in this type of automatic lift control mechanism. It is possible to quickly obtain a sufficiently deep plowing depth while making the most effective use of the engine power, without the risk of causing problems such as The goal is to make it possible to use only a relatively narrow settable range.

The technical means of the present invention taken to solve the above problems are as follows:
an actual rotation detector that detects the actual rotation speed of the engine; a rotation speed setting device that transmits a signal corresponding to the reference rotation speed of the engine; and a level detector that detects the actual height of the tilling device relative to the traveling aircraft; A plowing depth setting device that sends a signal corresponding to a target set plowing depth is incorporated into an automatic lifting control mechanism of a tilling device that is attached to a traveling machine so that it can be raised and lowered, and this automatic lifting control mechanism is the rotation speed setter, the actual rotation detector, the plowing depth setter, and
Based on the signals from each of the level detectors, the plowing depth setter is set in a state where the tilling load, which is represented by the deviation between the signal from the rotation speed setter and the signal from the actual rotation detector, is within a predetermined range. A control mode for automatically raising and lowering the tilling device so that a plowing depth deviation represented by a deviation between a signal from the plowing depth setter and a signal from the level detector is reduced, and a control mode for automatically raising and lowering the tilling device so as to reduce a plowing depth deviation represented by a deviation between a signal from the plowing depth setter and a signal from the level detector. A control mode for automatically raising and lowering the tilling device based on the deviation from the plowing depth so that the plowing depth deviation becomes zero; According to this technology, the tilling device is configured to be able to switch freely to a control mode in which the tilling device is automatically raised and lowered so that the tilling device is positioned at a sufficiently deeper tilling depth than the target set tilling depth within a predetermined tilling load range based on the signal. The effects of the present invention obtained by taking the measures are as follows.

In other words, there is a control mode that controls the tilling depth deviation to be small while the tilling load is within a predetermined range, or a control form that controls the tilling depth deviation to be zero based on the deviation between the signal from the tilling depth setter and the signal from the level detector. In addition to the control mode in which the tillage device is automatically raised and lowered based on the detection results of the tillage load and the actual plowing depth, the automatic lifting control mechanism is configured to be switchable. Therefore, by simply switching the automatic lift control mechanism to this control mode, a sufficiently deep plowing depth can be quickly obtained while making the most effective use of engine power, regardless of the target plowing depth set by the plowing depth setting device. Moreover, in this control form, since there is no target plowing depth per se, the raising and lowering control of the tiller is performed within the range of allowable tilling load, which prevents unreasonable loads from continuing to act on the engine or from hunting. There is also little risk of causing a phenomenon.

Furthermore, it is advantageous that a plowing depth setting device having a relatively narrow settable range that is sufficient to set a plowing depth suitable for normal tilling work can be used.

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

FIG. 1 shows a tiller in which a rotary tiller 1 is attached to the rear of a tractor 2 so as to be able to rise and fall freely, and the rear propulsion wheels 4, 4 and the rotary tiller 1 are powered by an engine 3 mounted on the tractor 2. It is also configured to drive a hydraulic pump (not shown) that drives a single-acting hydraulic cylinder 5 for raising and lowering the rotary tilling device 1.

The tilling device 1 is suspended and supported by a lifting arm 6 that is interlocked with the hydraulic cylinder 5, and is driven up and down by controlling an electromagnetic control valve of the hydraulic cylinder 5 as described below. It is configured.

Next, a mechanism for automatically controlling the raising and lowering of the tilling device 1 will be explained with reference to the block diagram shown in FIG. 2.

That is, the signal E from the actual rotation detector 7 that detects the actual rotation speed of the engine 3 and the signal A from the rotation speed setter 8 that sets the engine maximum rotation speed according to the accelerator setting are sent to the first subtractor 9. is applied to the engine load (in other words, the tilling load) by the amount of decrease in engine rotational speed (A-E
).

Further, the signal from the first subtractor 9 and the signal H from the plowing depth setting device 10 for adjusting the target for the tilling device 10 and the tractor 2-j and changing the target plowing depth as a result are sent to the adder 1.
1, and the output signal from this adder 11 and the signal from the level detector 12 which detects the actual height of the tilling device 1 with respect to the tractor 2 are applied to the second subtractor 13.
is configured to be applied to.

Then, the signal from this second subtracter 13 is transmitted to the first and second discriminators 14.15.
4.15, the ascending valve 16 and descending valve 17 of the hydraulic cylinder 5 are opened as described later.

Further, between the adder 11 and the second subtracter 13, between the level detector 12 and the second subtracter 13, and between the power supply V and the valve 16,
, 17, and between the plowing depth setter 10 and the adder 11, there are interlocking switches 22a, 2 which are operated by one rotary operating tool 22 provided on the operation panel 24 of the control section.
2b, 22C, and 22d are interposed, and as the switches 22a... are operated, the tilling device 1 is controlled to move up and down as described below.

In other words, if the switch 22a is connected to the R contact point, the structure is designed to automatically control the elevation so that the plowing depth approaches the target set plowing depth based on the detection result of the engine load (plowing load). has been done.

In other words, the signal voltage (A-E) from the first subtractor 9 increases as the engine speed decreases, and the plowing depth setting device 10
The signal voltages H and L from the level detector 12 are set to decrease as the tilling depth increases, and when the tilling device 1 is located at a shallower position than the set tilling depth position while the engine rotation speed is decreasing. If the amount of rotational speed reduction (engine load) (A-E>o) and the amount of deviation from the set plowing depth of the tilling device 1 (H-L<0) are equal, the output voltage from the second subtractor 13 becomes zero, and it is determined that there is no need to raise or lower the tilling device 1. From this state, the engine rotation speed decrease amount (A-E)
increases, the output voltage from the second subtractor 13 becomes positive, and the first discriminator 14 indicates that the tilling device 1 needs to be raised.
, and conversely, the engine speed reduction amount (A-E
) decreases, the output voltage from the second subtractor 13 becomes negative, and the second discriminator 1 indicates that the tilling device 1 needs to be lowered.
It is determined by 5.

Then, the raising and lowering of the tilling device 1 is controlled so that a balanced relationship is established based on the change in the amount of reduction in engine rotational speed and the change in the signal from the level detector 12 as the tilling device 1 is raised and lowered.

In other words, if the output voltage from the second subtractor 13 is positive,
The lifting valve 16 of the hydraulic cylinder 5 is opened to drive the lift arm 6 to swing upward, and conversely, when the output voltage is negative, the hydraulic cylinder 5 is opened so that the lift arm 6 and the tilling device 1 are lowered by their own weight. It is configured to open the descending valve 17.

Incidentally, a switch 19 is provided in the output circuit of the tillage depth setting device 10 and can be connected to the setting device 18 to which a sufficiently large positive constant signal is set.
By inputting the fixed signal from the setting device 18 into the adder 11 instead of the signal H from the setting device 10 through the operation of It is configured so that it can be operated upward, and if the switch 19 is returned to its original state, it can return to the above-mentioned control again.

In other words, this switch 19 is configured as a manual operation mechanism for pulling out the tilling device 1 from the ground when turning the machine during plowing work under automatic control, and returning it to plowing work under single-motion control after turning. There is.

This switch 19 is operated by a snap lever 21 provided on the column of the control handle 20.

Moreover, if the switch 22a is connected to the contact point P, automatic elevation control is performed so that the plowing depth deviation represented by the deviation between the target height and the actual height with respect to the tractor 1 becomes zero. will be revealed.

In other words, the signal H from the plowing depth setter 10 and the level detector 1
The second subtractor 13 subtracts and compares only the signals from the second subtractor 13, and the tilling device 1 is controlled to move up and down based on the result.

That is, the tilling device 1 is configured to be dynamically controlled to move up and down to a height set by the setting device 10 and then stopped.

Further, when the switches 22a... are connected to the contact M, all inputs to the second subtractor 13 are cut off and the automatic control is canceled, and the lift valves 16 and 17 are switched to the respective changeover switches. It becomes operational only by the operation of 23.

This switch 23 is disposed on the front panel 24 of the control section together with the tilling depth setting device 10.
The tilling device 1 is configured to be able to be moved up and down as desired and fixed in accordance with the switching direction of No. 3 and the operating time thereof.

In addition, if the switch 22a is connected to the contact R, the actual rotation is adjusted so that the working state is sufficiently deeper than the target plowing depth when the switch 22a is connected to the contact R. The structure is such that the tilling device 1 is automatically controlled to move up and down based on the results of tilling load detected by the detector and rotational speed setter 8 and the signal from the level detector 12.

In other words, the voltage from the tillage depth setter 10 becomes zero, and automatic elevation control is performed with the tillage device 1 inserted as deeply into the ground as possible.

In this control form, the output signal (A
-E-L) becomes zero when the signal (A-E) from the first subtractor 9 is equal to the signal from the level detector 12,
The signal (A-E) from the first subtractor 9 is sent to the level detector 12.
If the signal is larger than the tillage load, it will be positive, and in the opposite case, it will be negative.
While the signal (A-E) from the level detector 12 increases as the engine speed decreases, the signal from the level detector 12 is set to decrease as the plowing depth increases, as described above. Since the switch 22a is connected to the contact R in a balanced state, the switch 22a is connected to the contact R.
When a is switched to contact and this control mode is adopted, the signal H from the plowing depth setter 10 momentarily becomes zero, so that the signal from the adder 11 (A-E>O) changes from the original. (A-E+H), the output signal (A, -E-L) from the second subtractor 13 becomes a negative signal, and a lowering command for the tilling device 1 is issued. Accordingly, as the plowing depth by the tilling device 1 increases, the signal from the first subtractor 9 side (
The value of A-E) changes in the direction of increasing, and the signal from the level detector 12 changes in the direction of decreasing (decreases as the plowing depth increases).
In this case, balance is achieved in a state where the plowing depth is deeper than in the case of the control mode connected to the contact point R.

Also, if the switch 22a... is connected to the contact T, the lifting valve 16 is opened and the tilling device 1 is lifted.
Furthermore, when the tiller 1 is raised to the stroke end, the switch 25 that is brought into contact and pressed by the lifting arm 6 is opened, and the raising of the tilling device 1 is stopped.

That is, the tilling device 1 is raised to the stroke end,
and maintained in that position, the tractor 1
When attaching a front loader (not shown) to the front of the
Used to keep the aircraft balanced.

Furthermore, if the switch 22a is connected to the OFF contact point, all controls for raising and lowering the tilling device 1 described above are stopped, and when the engine is started, the tilling device 1 is configured to perform the above-mentioned control. It has a safety effect to prevent accidental lifting and lowering.

[Brief explanation of the drawing]

The drawings show an embodiment of the tiller with an automatic lift control mechanism according to the present invention, in which FIG. 1 is a side view of the tiller, FIG. 2 is a block diagram, and FIG. 3 is a front view of the operating tool. 1... Cultivation device, 2... Traveling machine, 3
...Engine, 7...Actual rotation detector,
8... Rotation speed setting device, 10... Cultivating depth setting device, 12... Level detector.

Claims (1)

[Claims] 1 Actual rotation detector 7 that detects the actual rotation speed of the engine 3
, a rotation speed setting device 8 that transmits a signal corresponding to the reference rotation speed of the engine 3, and a tilling device 1 for the traveling machine body 2.
A tilling device 1 is equipped with a level detector 12 that detects the actual height of the soil and a tilling depth setting device 10 that sends a signal corresponding to the target set tilling depth. This automatic elevation control mechanism is incorporated into the automatic elevation control mechanism of A, E, H. Based on L, the tilling depth is set in a state where the tilling load represented by the deviation (A-E) between the signal A from the rotation speed setter 8 and the signal E from the actual rotation detector 7 is within a predetermined range. A control mode for automatically raising and lowering the tilling device 1 so that the tilling depth deviation represented by the deviation (H-L) between the signal H from the level detector 10 and the signal line from the level detector 12 becomes small, and the tilling depth setting device signal from 10 and level detector 12
A control form in which the tilling device 1 is automatically raised and lowered based on the deviation from the signal from Based on the signal from the level detector 12, the tilling device 1 is automatically raised and lowered so that the tilling device 1 is positioned at a sufficiently deeper tilling depth than the target tilling depth within a predetermined tilling load range. A tiller with an automatic lifting control mechanism.