JPH0738763B2 - Lift control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a lifting control for raising and lowering a ground work device in order to maintain a relative distance between the ground work device and a rear ground of the ground work device at a target set value. More specifically, the present invention relates to control when lowering a ground work device in a non-grounded state.

[Conventional technology]

As the control performed when lowering the ground working device configured as described above, there is, for example, the control shown in JP-A-63-148907, and in this conventional example, when the ground working device is lowered. In order to prevent the plowing depth from deviating to a value deeper than the desired value, when descending the ground work device, the post-life is performed so as to temporarily deviate the control target to a shallow example. .

[Problems to be Solved by the Invention]

Here, considering the form of control, as described above,
In the control for maintaining the relative distance between the ground work device and the rear ground of the ground work device at the target set value, if the ground work device is present within a predetermined range based on the control target, the lifting control is not performed. By forming a so-called dead zone, control caused by slight vibration such as rocking of the vehicle body and turbulence of the ground is suppressed, and a smooth lifting operation is ensured.

Therefore, even in the control device of the conventional example, a dead zone is formed immediately after the ground work device is lowered with reference to the control target deviated to the shallow side. Will be allowed to float up and down.

However, even if the control target is deviated to the shallow side in order to make the working depth shallow when the ground working device descends, if the ground working device is allowed to float vertically due to the formation of the dead zone as described above, This leads to uneven plowing depth.

An object of the present invention is to provide a control device that reliably prevents the ground work device from being displaced to a side deeper than a desired working depth when lowering the ground work device in a non-grounded state by rational modification. There is a point in configuring.

[Means for Solving the Problems]

The feature of the present invention is, in the lifting control device that maintains the relative distance between the ground work device and the ground as described above,
When lowering the ground work device in the non-grounded state, while temporarily shifting the control target level from the target set value to the shallow side until a predetermined timing after the ground work device is lowered,
Based on this control target level, the side that performs the rising control,
And a control means for narrowing the width of the dead zone on the side for performing the raising control among the dead zones formed with a predetermined width on the side for performing the lowering control to a predetermined timing after the descent of the ground work device. It has the following features and effects.

[Work]

According to the above feature, when the ground work device in the non-grounded state descends, the control target level deviates from the target setting to the shallow side until the predetermined timing after the descending, and the width of the dead zone on the side where the ascending control is performed is narrow. Therefore, the descending of the ground working device to the deep side is suppressed despite the descending with respect to the flat ground in the unplowed state, and at the same time, the ascending control is performed more frequently. The floating of the ground work device can be suppressed. Further, in this way, the deviation of the control target level and the narrowing of the dead zone are completed at a predetermined timing after the descending of the ground work device, and therefore, after this control, the plowing depth and the width of the dead zone are appropriately adjusted. Enables easy lifting control.

〔The invention's effect〕

Therefore, when lowering the ground working apparatus in the non-grounded state, the plowing depth desired by the ground working apparatus is lowered by a relatively simple modification by changing the control target level and providing control means for adjusting the width of the dead zone. The control device was constructed so that it could be prevented from being displaced to a deeper side.

Particularly, in the present invention, the control means can be configured by software, and when configured by software in this way, the above effect can be achieved by a very simple modification of changing the program.

〔Example〕

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

As shown in FIGS. 2 to 4, a lift arm (3) that moves up and down by the operation of the hydraulic cylinder (2) is provided at the rear of the vehicle body (1) of the agricultural tractor, and is lifted and lowered by this lift arm (3). A rotary tiller (5) as an example of a ground work device is connected via a three-point link mechanism (4).

As shown in the figure, on the right side of the driver's seat (6) of the vehicle body (1), there is provided a control box (7) for controlling the raising and lowering of the rotary tiller (5). The tilling depth setting device (9) operated by the dial (8) to arbitrarily set the tilling depth of the rotary tiller (5), and the rotary tiller (5) as the ground (G) during the plowing work. Elevating switches (10) for forcibly raising to a predetermined level to be separated from each other are provided.

In addition, at the base end of the lift arm (3), a potentiometer type anti-vehicle level detector (11) for detecting the anti-vehicle level of the rotary tiller (5) based on the swing angle of the lift arm (3). ) Is provided and the rotary tiller (5)
Is a potentiometer-type working depth detector (12) for detecting the relative distance between the rotary tiller (5) and the rear ground of the rotary tiller (5) based on the swinging posture of the rear cover (5a). Is provided.

As shown in FIG. 2, the raising / lowering control system in this agricultural tractor includes the tilling depth setting device (9), the tilling depth detector (12), the vehicle body level detector (11), and the raising switch (10). Has a control device (13) to which a signal of (1) is input, and the control device (13) (an example of control means) is configured to output an operation signal to the solenoid valve (14) for the hydraulic cylinder (2). Further, the control device (13) operates according to the flowchart of FIG.

That is, in the operation of the control device (13), the flag is set to "0" at the start of control, the state of the rising switch (10) is determined, and if it is in the OFF state, the flag is determined (# 1, # 2 , # 3
Step).

Immediately after the control is started, since the flag is "0", next, the dead zone (S) on the rising control side and the dead control side,
After setting the width of (S) to a normal value as shown in FIG. 1 (a), a signal from the tilling depth setting device (9) is set as a control target,
Automatic depth control is performed by feeding back the signal from the depth detector (12) (# 4, # 5 steps).

As shown in FIG. 4, this automatic tillage depth control keeps the relative distance between the upper surface level of the ground raised by the tillage of the rotary tiller (5) and the rotary tiller (5) constant. In this control, the rotary tiller (5) is moved up and down in the direction in which the rear cover (5a) maintains its swinging posture.

Further, at the time of work, every time the vehicle body (1) reaches the headland on the edge of the ridge, the automatic tilling depth control is interrupted to raise the rotary tiller (5) to a non-ground level to turn the vehicle body (1). It is also necessary to turn on the raising switch (10) when performing this raising operation.

In other words, the raising switch (10) turns on during the automatic plowing control.
When operated, raise the rotary tiller (5) until a predetermined level is detected by the vehicle body level detector (11),
The flag is set to "1"(# 2, # 6, # 7 steps).

This raising operation continues until the raising switch (10) is turned off. When the raising switch (10) is turned off, the flag is set to "1", so after branching in step # 3, first start the timer, then , The widths of the dead zones (S), (S) on the ascending control side and the descending control side are set to narrow values as shown in Fig. 1 (b), and the signal from the working depth setting device (9) is set to the shallow side. 80%
After eccentricity, this deviated signal is set as a control target, and automatic tilling depth control that feeds back the signal from the tilling depth detector (12) is performed, and this automatic tilling depth control is performed until the timer counts up. Continue and set the flag to "0" (steps # 2, # 3, # 8, # 9, # 10, # 11, # 12, # 13).

As shown in FIG. 3, this automatic plowing depth control is started after lowering the rotary tiller (5) on the flat ground in the unplowed state. Until the cover (5a) comes into contact, the control target is deviated to the shallow side as described above, and the dead zones (S) and (S) are narrowed to reduce the width of the rotary tiller (5). The floating is suppressed.

Then, the program is set so that this control is continued until it is reset (# 14 step).

[Another embodiment]

In addition to the above-described embodiment, the present invention can narrow only the width of the dead zone on the side of raising control when lowering the ground work device, and the control means is software or hardware. Any of these may be used.

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 lifting control device according to the present invention.
Figure (a) is a side view showing the dead zone of normal width, Figure 1 (b) is a side view showing the dead zone of the narrowed width, Figure 2 is a block circuit diagram of the control system, and Figure 3 is rotary tillage. FIG. 4 is a side view of the rear part of the vehicle body immediately after the device is lowered, FIG. 4 is a side view of the rear part of the vehicle body during work, and FIG. 5 is a flowchart showing the operation of the control device. (5) …… Ground work device, (13) …… Control means, (S)
...... Dead zone.

Claims (1)

[Claims] 1. A ground work device (5) and a ground work device (5).
Is a lifting control device that lifts and lowers the ground work device (5) in order to maintain the relative distance to the rear ground of the target value.
When lowering the ground work device (5) in a non-grounded state, the control target level is temporarily deviated from the target set value to a shallow side until a predetermined timing after the ground work device (5) is lowered. Based on the control target level, one of the dead zones (S) and (S) formed with a predetermined width on the side that performs the ascending control and the side that performs the descending control, respectively An elevating control device comprising a control means (13) for narrowing the width of the dead zone (S) to a predetermined timing after the descent of the ground work device (5).