JPH0614808B2 - Feedback type automatic tilling depth control device - Google Patents

Description

The present invention relates to a feedback type automatic tilling depth control device.

[Conventional technology]

Taking a rotary tiller as an example of the ground work device, the conventional automatic tiller control device detects the tiller depth of the rotary tiller from the positive position of the rear cover of the rotary tiller and detects the tiller depth of the rotary tiller. A tilling depth control system is configured by linking the rear cover and a lifting control system so that the rear cover maintains a predetermined swinging posture in order to maintain the device at a set working depth (not described in the reference).

[Problems to be solved by the invention]

Also, when considering the lifting operation of the ground work device, normally,
The ascending speed of the ground work device is lower than that of the descending operation, and the heavier the ground work device, the slower the speed.

However, since the conventional tilling depth control system was constructed without paying much attention to the weight of the ground work device, the movement in the ascending direction at the time of work could not follow the fluctuation of the working depth and the plowing surface could be roughened. There is also.

An object of the present invention is to reasonably configure a control device that is less likely to cause an operation delay in the upward direction due to the weight of the ground work device.

[Means for solving problems]

The feature of the present invention resides in that the heavier the ground work device, the more the correction means for increasing the control sensitivity in the ascending direction is provided, and the action and effect are as follows.

[Work]

The heavier the ground work device, the more the correction means
The control sensitivity on the ascending control side in the working depth control operation is enhanced. For example, the dead zone width on the rising control side is narrowed as the weight of the ground work device is larger, or is corrected so that the gain on the rising control side of the working depth detection signal for feeding back the actual working depth is increased. As a result, the control sensitivity on the rising side is increased, so that sensitive control is performed on the rising side.

〔The invention's effect〕

Regardless of the weight of the ground work device, the movement in the ascending direction is sensitive to changes in the plowing depth during plowing work, preventing adverse effects such as roughening the plowing surface due to delay in tracking. In addition, it has become possible to provide an automatic tilling depth control device that can perform a smooth tilling depth control operation.

〔Example〕

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

As shown in FIG. 4, a pair of left and right lift arms (3) that swing up and down by the operation of the hydraulic cylinder (2) are provided at the rear of the vehicle body (1) of the agricultural tractor, and at the rear end of the vehicle body (1). A rotary tiller (5), which is an example of a ground working device, via a link mechanism (4) that is vertically moved by the lift arm (3).
Are connected.

As shown in the figure, the rotary tiller (5) is swingable at the chain case (5a), a large number of tillage claws (5b) ..., the upper cover (5c), and the rear end of this upper cover (5c). Provided on the rear cover
(5d) The upper cover (5c) is provided with a cover sensor (6) for detecting the working depth of the rotary tiller (5) from the swing amount of the rear cover (5d).

As shown in FIGS. 1 and 4, the lift arm (3)
A weight sensor (7) consisting of a strain gauge is attached to the support shaft of the to detect the weight of the ground work device from the amount of twist, and the weight sensor (7) is attached to the agricultural tractor.
There is provided a feedback-type automatic tilling depth control device (A) including a correction means (C) for increasing the control sensitivity in the ascending direction as the weight of the ground work device detected by (1) increases.

That is, the plowing depth control system includes a plowing depth setting device (9) operated by the plowing depth setting dial (8), the cover sensor (6), and a weight sensor.
(7), the automatic tilling depth control device (A), in which signals from these are input, and which comprises a microprocessor, this control device
Operated by a signal from (A), and the hydraulic cylinder (2)
Solenoid valve (10) for controlling the
(C) is a detection signal from the weight sensor (7) and is a rotary tiller
As the weight of (5) is determined to be larger, the dead band width on the rising control side is set narrower, and operation is performed to increase the control sensitivity,
This correction means (C) is # 3, # in the flowchart of FIG.
It consists of 4 steps.

Then, at the time of automatic tilling depth control, the tilling depth setting signal and the weight sensor signal are respectively inputted (steps # 1 and # 2), and the dead zone width to the ascending control side based on the weight sensor signal.
(α) is obtained by calculation (# 3 step). Incidentally, the dead zone width (α) is set narrower as the weight of the rotary tiller (5) is larger.

When the dead zone width (α) is obtained in this way, the control target (D) is then determined based on the tilling depth control signal, and the third
As shown in the figure, the dead band width (β) on the descending control side and the dead band width (α) on the ascending control side are added based on the control target (D) (# 4 step).

It should be noted that the sum of the two dead band widths (α) and (β) becomes a neutral region where the raising / lowering control is not performed, and an ascending operating region and a descending operating region are formed with the neutral region sandwiched therebetween, so that FIG. As shown in, each control is performed by the rocking end of the rear cover (5d) entering into each area. Incidentally, each area is given as a voltage value and is held in a memory (not shown) as a digital signal corresponding to this voltage value, and this digital signal and the voltage value from the cover sensor (6) are converted. The control direction is determined as follows by the digital signal thus obtained.

When the dead band width is set in step # 4, the cover sensor
While inputting the signal (L) from (6) (# 5 step), the control direction is discriminated based on this dead zone width (# 6, # 7 steps), after which three types of control are performed ( # 8, # 9,
# 10 steps).

The automatic working depth control device (A) is installed in a control box (12) provided on the right side of the driver's seat (11), and the working depth setting dial (8) is provided on the upper surface of the control box (12).
Is provided.

Also, in the plowing depth control system, the magnitude of the force changes to raise the rotary tiller (5) depending on the swinging posture of the lift arm (3), but the force is changed at the position of the support shaft of the lift arm (3). Since the magnitude of the force is detected, the control sensitivity is adjusted in association with the change in the magnitude of the force.

[Another embodiment]

The present invention may be implemented, for example, by including a system for artificially inputting the weight of the ground work device via a switch or the like in addition to the above-described embodiment, and when the system for inputting such a weight is provided, the lift can be lifted. Even better control can be performed by adjusting the control sensitivity in accordance with the swing angle of the arm.

Further, the present invention can be applied to the control of the plow, and the automatic tilling depth control device may be configured by a hard circuit such as a comparator and a logic gate, and a means for enhancing the control sensitivity. Alternatively, the signal from the cover sensor can be configured to adjust the gain.

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 THE DRAWINGS The drawings show an embodiment of a feedback type automatic tilling depth control device according to the present invention, FIG. 1 is a block diagram showing the configuration of the control device, and FIG. 2 is an operation of the control device. FIG. 3 is a diagram showing a control target for the rear cover, a dead zone, etc., and FIG. 4 is an overall side view of the agricultural tractor. (5) …… Ground work device, (C) …… Correction means.

Claims (3)

[Claims] 1. A feedback type automatic tilling depth control device comprising a correction means (C) for increasing the control sensitivity in the ascending direction as the weight of the ground work device (5) increases. 2. The feedback type automatic tilling depth control device according to claim 1, further comprising a system for artificially inputting the weight of the ground work device (5). 3. A sensor for detecting the weight of the ground work device (5).
The feedback type automatic tilling depth control device according to claim 1, further comprising a system for inputting a signal from the sensor (7) and the sensor (7).