JPH073B2 - Depth control device for ground work machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a depth control device for a ground work machine that is run by being pulled by a tractor, and in particular, a ground work machine is raised by a manual operation. The present invention relates to a depth control cut when descending after being made to move.

[Conventional technology]

Conventionally, the depth control device for this type of ground working machine has issued an operation command from the control unit so as to perform respective raising and lowering operations according to the difference between the detection value by the tilling depth sensor and the tilling depth setting value by the tilling depth setting device. Output and raise and lower the lift arm via the proportional solenoid valve for raising or the proportional solenoid valve for lowering,
The rotary work was done by controlling the working depth.

[Problems to be solved by the invention]

When performing the rotary work of the conventional ground work machine under the depth control (plow depth control), the operator manually moves the ground work machine to raise it to the vicinity of the raising position and then lowers it. While the rear cover of the rotary is in contact with the ground, the rear cover swings due to inertia or wind pressure and becomes extremely unstable. Then, in this unstable state, when the rear cover rises around the hinged part at the upper end, the working depth sensor detects the action of the rear cover, and as a result, based on the raising command from the control unit, the ground is grounded. The work machine automatically changes to a rising motion. That is, even though the ground work implement is lowered by manual operation, the ground work implement is changed to be raised by the operation command of the depth (plowing depth) control unit based on the swing of the rear cover. For example, it causes a so-called hunting phenomenon. Then, there arises a problem to be solved in order to prevent such a hunting phenomenon from occurring.

[Means for solving problems]

The present invention has been proposed as a solution to the above problems, and a plowing depth sensor for detecting the plowing depth of a ground working machine that is connected to a rear portion of a tractor so as to be vertically movable by a hydraulic lifting mechanism. And a vertical movement to the rear part of the ground work machine so that it can be moved up and down according to the difference between the value detected by the tilling depth sensor and the value set by the tilling depth setting device. In the tractor having a depth control unit, which is constructed so that the tilling depth sensor is configured to detect the tilling depth in accordance with the rotational position of the rear cover that is formed so as to be in sliding contact with the cultivated soil surface, When the ground work implement that has been lifted to the vicinity of the raised position is lowered, a depth control device for the ground work implement provided with means for restraining the rising output of the ground work implement based on the swinging of the rear cover for a fixed time. Is shall.

[Action]

This invention is for depth control rotary work.
When the operator manually raises the ground work implement to a position close to the raising position and then further lowers the ground work implement by hand, the rear cover of the rotary is almost unmoving due to the suspended wind The working depth sensor is in equilibrium with the condition and stops working. When descending in this way, even if the rear cover swings during descent and becomes unstable, in such a case, the movement of the rear cover is controlled by means for restraining the rising output of the ground work machine only for a certain period of time. Since the tilling depth control based on the above is not performed, the ground work machine can be lowered at a constant lowering speed. In addition, in detail, when the ground work implement rises up to the vicinity of the raised position and is lowered, the rear cover oscillates due to inertia or wind pressure, and even if the plowing depth control based on this oscillation tries to operate, Since the plowing depth control is cut for a certain period of time, the hunting phenomenon of the ground working machine based on the plowing depth control does not occur at all, and the landing can be smoothly performed to shift to the rotary work.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the attached drawings. As shown in FIG. 2, a ground work implement (2) such as a rotary is attached to the rear part of the tractor (1) as a towing vehicle to a pair of left and right lift arms (3) and (3), and left and right lift rods (4) ( Left and right lower links (5) and (5) swinging up and down via 4) and the top link (6) in the upper center
Is connected by a working machine connecting link (7), and the working machine connecting link (7) is lifted and lowered by a lift cylinder (8) using the hydraulic pressure of its lift arms (3) (3). The lifting / lowering operation is performed by a hydraulic lifting / lowering mechanism (9) that rotates. In addition, in order to control the pressure oil supply / discharge to / from the lift cylinder (8), the operation command of the control unit (10) configured by a microcomputer or the like is accompanied by the operation of the lifting switch (S ₃ ). The lift proportional drive solenoid valve (13) or the lift proportional drive solenoid valve (14) is opened and closed by being amplified by the drive drive unit (11) or the drive drive unit (12) for lowering the lift cylinder. The pressure oil of the pump (15) is supplied to the (8) to lift the lift arms (3) and (3), or the lift cylinder (8).
The pressure oil is discharged and the lift arms (3) and (3) descend.

Furthermore, a lift arm angle sensor (S ₁ ) formed by connecting a position lever (I ₁ ) provided near the cockpit and a detection axis of a rotary potentiometer to the lift arm (3).
Are respectively connected to the control section (10), and the height detection value detected by the lift arm angle sensor (S ₁ ) is added to the set value set by the operation of the position lever (I ₁ ). The control unit (10) sends an elevating command to the ascending drive unit (1
1) Or, the output is output to the descending drive section (12), and the elevation control (position control) is performed by this.

For automatic control of the working depth, the working depth setting value (I ₂ ) made of a volume-like device is used to set the working depth setting value to the working depth sensor (S ₂ ) of the ground work machine (2). The solenoid valve for raising (1
3) and the descending solenoid valve (14) use proportional solenoid valves that open and close the flow oil opening area in proportion to the amount of current applied to the solenoid. A control current having a magnitude proportional to the difference is output from the control unit (10), and a pulse current having a pulse width proportional to the control current value is applied to the solenoid valve to raise and lower the ground work implement (2). The operation is performed to control the working depth.

Further, the tilling depth sensor (S ₂ ) in the illustrated example is one in which the movement of the cover (17) sliding on the surface of the cultivated soil is detected by, for example, a linear movement type potentiometer (18). The rear cover (17) hinged to the rear part of the body of the ground working machine (2) so as to be vertically rotatable is fixed by the lifting rod (19) in the lifting posture in which no tilling work is performed. It is held at the height of the
When it touches the ground as it descends, it turns upward, and the working depth corresponding to this turning position is detected by the potentiometer (18).

Further, in the embodiment of FIG. 1, a mix control unit for position control and plowing depth (depth) control is shown, but the control unit (10) is also applied to other mix control. It should not be limited to control only. The mix control of this embodiment is operated via the work mode switching board (T). That is, the work mode switching board (T) can be switched to the position control and the plowing depth control, respectively. Further, a lift switch (S ₃ ) is provided near the driver's seat, and the lift switch (S ₃ ) is manually operated by an operator, and the ground work machine (S ₃ ) is operated based on this operation. 2) can be raised and lowered. Therefore, the ground work machine (2) is lifted or lowered by the operator manually operating the position lever (I ₁ ) or the lifting switch (S ₃ ). In addition, it automatically moves up and down by controlling the working depth, controlling the draft, and controlling the draft.

As described above, the operator operates the position lever (I ₁ )
Alternatively, when the ground work implement (2) is lifted up to the vicinity of the lifted position by the lifting switch (S ₃ ) and then manually lowered, the rear cover (17) of the rotary (20) has a butterfly at the upper end. Rotate downwards through the attachment, and the working depth sensor (S ₂ )
Are in a balanced state, and when the ground work implement (2) is lowered from this state, a fixed time (about 0.3 seconds to 0.8 seconds)
The control section (10) is provided with a plowing depth cut control section (10a) so as not to update the detection result of the rear cover (17).

Therefore, this embodiment will be described with reference to the flow chart of FIG. First, it is determined in step whether or not the working mode switching board (T) has switched to the working depth control work. When the working depth control work is being performed, the operator manually operates the lifting switch (S ₃ ) or the position lever (I ₁ ) at the step to raise the ground work implement (2). It is judged whether or not the position has been raised close to the position (step). If the ground work implement (2) is raised to the vicinity of the raised position, a depth control invalidation request (step) is set by an operation command from the control unit (10a), and the lift position and the lift arm angle are set. Therefore, the operation of the lift arm is determined (step), and the ground work machine (2) moves up and down. When the ascending operation (step) is manually performed and further the descending operation is manually performed, it is determined by the step whether or not there is a depth control invalidation request. Needless to say, this depth control invalidation request is made by outputting an operation command from the tilling depth cut control section (10a) as in the step. When the depth control invalidation request is made, the depth invalidation request is reset by the step, and then the depth invalidation request is cultivated by the step for a fixed time, that is, for about 0.3 seconds to 0.8 seconds. Since the depth control is cut off, and therefore the plowing depth control is not performed for the above-mentioned fixed time, even if the rear cover (17) makes an unstable rocking motion while the ground work implement (2) is descending. The operation of the rear cover (17) does not operate the plowing depth sensor at all, and accordingly, the hunting phenomenon of the ground working machine (2) does not occur at all, and the rear cover (17) and the ground working machine (2) land smoothly. Then, when the fixed time has elapsed by the step, the counting of the timer is stopped, and thereafter, it becomes possible to shift to the rotary work by the plowing depth control.

In more detail, when the ground work implement (2) is manually moved up to a position near the raised position and is also lowered manually, the rear cover (1
7) has a constant inclination angle and the working depth sensor (S ₂ ) is almost inoperative, but when the ground working machine (2) is lowered from this state, the rear cover (17) has inertia or wind pressure. Therefore, there is a case where it is rotated upward through the hinged portion, or it is rotated downward due to its own weight. In this way, the rear cover (17) oscillates and causes unstable movement. The plowing depth sensor (S ₂ ) operates based on this unstable movement, and the lifting command from the control unit (10) is output. Ground work machine (2)
Causes a so-called hunting phenomenon during its descending.

Therefore, in this embodiment, as described above, when the ground work implement (2) is manually lowered, it takes a certain time, that is, 0.
The plowing depth control based on the plowing depth sensor (S ₂ ) was cut only in the time zone of 3 seconds to 0.8 seconds. The fixed time, which is the depth control invalidation request time, is determined by the weight of the ground work implement (2) and the flow path resistance of the hydraulic lifting mechanism (9). Since there is a tendency to quickly descend from the upper position of hoisting to the surface of the earth, the fixed time can be set shorter for a heavy ground work implement (2). After this fixed time has passed, that is, almost all the ground working machine (2)
During the descent, the ground work implement (2) is lowered to a position where there is no fear of causing a hunting phenomenon, then the depth control invalidation request is stopped, and it is possible to shift to rotary work by the working depth control. . Thus, the operation procedure of them can be understood by referring to the flow chart of FIG.

〔The invention's effect〕

As described in detail in one embodiment of the preceding paragraph, when the ground work implement is lowered in the automatic plowing mode during the depth work by the ground work implement, the rear cover does not cause hunting and smoothly It is possible to lower the ground work machine and improve work efficiency.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a block diagram of a control unit, FIG. 2 is a side view of a tractor to which a ground work implement is attached, and FIG. 3 is a flow chart. Explanation of code (1) …… Tractor, (2) …… Ground work machine (3) …… Lift arm, (4) …… Lift rod (5) …… Lower link, (6) …… Toplink (7)… … Work machine connection link, (8) …… Lift cylinder (9) …… Hydraulic lifting mechanism, (10) (10a) …… Control unit (11) …… Rise drive unit, (12) …… Driving drive Part (13) …… Raising proportional solenoid (14)… Descent proportional solenoid (15) …… Pump (I ₁ ) …… Position lever (I ₂ ) …… Tillage depth setting device (S ₁ ) …… Lift arm angle sensor (S ₂ ) …… Plowing depth sensor (T) …… Work mode switching board

Claims (1)

[Claims] 1. A rear part of the tractor is provided with a tilling depth sensor for detecting a working depth of a ground working machine which is vertically movable by a hydraulic lifting mechanism, and a detection value by the tilling depth sensor and a tilling depth setting device are provided. The rear cover is formed so as to move up and down according to the difference from the set value, is screwed to the rear part of the body of the ground working machine so as to be vertically rotatable, and is formed so as to be in sliding contact with the cultivated soil surface. In a tractor having a depth control unit configured such that the tilling depth sensor detects the tilling depth in accordance with the rotating position, when the ground work implement that has been lifted to the vicinity of the maximum rising position is lowered, A depth control device for a ground work machine, comprising means for restraining the rising output of the ground work machine based on the swing of the rear cover for a fixed time.