JPH0789768B2 - Desera controller for ground work machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a descending grounding speed control device for a ground work machine that travels while being towed by a towing vehicle such as a tractor. This is called control, in which the ground work implement is raised and then lowered, and in the case where it is grounded, the descending speed of the ground work implement is sharply reduced from immediately before the touchdown to a predetermined depth extremely slowly. The present invention relates to a descending ground contact speed control device that can be lowered.

[Conventional technology]

Conventionally, for example, a ground working machine such as a rotary machine automatically moves up and down the ground working machine so that the working depth set by an operator is maintained during rotary work. The hydraulic lifting mechanism is controlled to move up and down based on the difference between the depth setting value and the cultivation depth detection value detected by the cultivation depth sensor, so that the lift arm can be moved up and down. Then, when such a ground work machine is moved up and down at a constant speed, for example, in the case of lowering the ground work machine that has risen to ground it, if it is grounded at a normal speed. Especially, in the case of a rotary, when it comes into contact with the ground, the reaction force may cause a dashing phenomenon and the rotary work may not be performed. Therefore,
In order to prevent this dusting phenomenon, the desera control as described above is performed. This de-sera control raises the lift arm and then lowers it to ground the work implement (especially the rotary) to the ground. In order to prevent the above-mentioned dashing phenomenon, the descending speed is drastically reduced just before the grounding of the rotary. The grounding was performed very slowly, the ground was lowered to a predetermined depth, and thereafter the rotary operation was performed by the depth control.

[Problems to be solved by the invention]

During the above-mentioned rotary work, when performing the de-sera control when descending from the raised position and then shifting to the depth control, if the depth control moves to the depth control when the plowing depth sensor operates, it will be rapid until the set plowing depth is reached. Therefore, the detection from the tilling depth sensor will be deeper than the depth specified by the tilling depth setting device. So at that point,
If the control shifts from the Desera control to the Depth control, the Depth control will be delayed, and a defect that the rotary becomes too deep will occur. Therefore, there arise problems that must be technically solved in order to overcome these deficiencies.

[Means for solving problems]

The present invention has been proposed as a solution to the above problems in view of the above problems, and a plowing depth sensor for detecting the plowing depth of a ground working machine provided to be vertically movable by a hydraulic lifting mechanism, and a plowing depth. A hydraulic lifting mechanism having a tilling depth setting device and a sensor for detecting the angle of the lift arm, and performing a lifting operation according to the difference between the detection value of the tilling depth sensor and the setting value of the tilling depth setting device. A working unit having a control unit configured to perform up-and-down control, and the ground work machine, the working depth by depth control performed according to the difference between the detection value of the working depth sensor and the setting value of the working depth setter. When performing work, raise the ground work implement to a position near the upper limit by using the position lever or lift switch, then cut the depth control and lower the ground work implement. When making it, the land crop In a descending speed control device in which the descending speed is gradually decelerated so as to minimize the descending speed near the position where the machine comes in contact with the ground, and the machine descends gradually below the grounding position, Provided is a control unit configured to start the depth control at a point where the descending speed by the depth control based on the detection of the sensor becomes lower than the descending speed by the decera control, and by a command from the control unit,
It is an object of the present invention to provide a de-sera controller for a ground work machine configured such that the ascending proportional solenoid valve and the descending proportional solenoid valve are respectively excited to operate the hydraulic lifting mechanism.

[Action]

According to the present invention, when the rotary work is performed by the depth control and the de-sera control, and when the ground work implement (rotary) is lifted by the position lever or the elevating switch, for example, the lift arm is moved from the upper limit to a predetermined value. When the rotary is lowered from the raised position, when the rotary is lowered from the raised position, when the rotary is lowered from the raised position, the lifter is moved up to an angle (about 5 degrees) and the lift arm is lowered from that position. The descending speed is gradually decelerated so as to be the minimum, and gradually increases when it becomes below the ground contact position, and the depth control is performed at the point where the speed detected by the tilling depth sensor becomes lower than the decera control speed. Get started. That is, the speed by the de-sera control is compared with the speed by the depth control, and when the speed by the de-sera control becomes larger than the speed by the depth control, the transition from the de-sera control to the depth control is smooth, and the workability is good. It becomes.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the attached drawings. For the sake of convenience of description, a configuration which is conventionally known will be described at the same time. As shown in FIG. 2, at the rear of the tractor (1) as a towing vehicle, a ground work implement (2) such as a rotary is provided to a pair of left and right lift arms (3) (3),
Connected by a work implement connecting link (7) consisting of left and right lower links (5) and (5) swinging up and down via left and right lift rods (4) and (4), and a top link (6) in the upper center. And, the working machine connecting link (7) is lifted and lowered by a hydraulic lifting mechanism (9) that lifts and lifts the lift arms (3) and (3) by using hydraulic pressure or a lift cylinder (8). Is configured to operate.
Further, in controlling the supply / discharge of pressure oil to / from the lift cylinder (8), the operation command of the control unit (11), which is constituted by something like a microcomputer, rises as the lift switch (10) is operated. The rising proportional solenoid valve (14) or the descending proportional solenoid valve (15) is opened and closed by being amplified by the driving unit (12) or the lowering driving unit (13), and the lift cylinder (8 ) Is supplied with the pressure oil of the pump (16) to raise the lift arms (3) and (3), or the pressure oil of the lift cylinder (8) is discharged to lower the lith arms (3) and (3). Is configured.

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 (11), 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 (11) sends an elevating command to the ascending drive unit (1
2) or output to the descending drive unit (13), and the ascending / descending control is performed by this.

For depth control, the working depth sensor (S ₂ ) of the ground work machine (2) detects the working depth setting value set by the operator using the working depth setting device (I ₂ ) consisting of a volume control. The rising solenoid valve (1
4) and the lowering solenoid valve (15) are 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 section (11), 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). It is doing the action.

Further, the tilling depth sensor (S ₂ ) in the illustrated example uses one that detects the movement of the rear cover (17) that is in sliding contact with the cultivated soil surface by, for example, a linear movement type potentiometer (18), The rear cover (17), which is hinged to the rear part of the body of the ground work machine (2) so as to be able to rotate up and down, is fixed by the lifting rod (19) when it is in a lifting posture where no tilling work is performed. Although it is held at the height, it is grounded from the lifting posture (2)
When it touches the ground as it descends, it rotates upward and the working depth corresponding to this rotational position is detected by the potentiometer (18).

Further, as described above, the ground work machine (2) is used by using a structure in which the rotation angle of the tractor (1) of the lift arm (3) with respect to the machine body is detected by a rotary potentiometer. ) Ascends and then descends and immediately before the start of touchdown, the descent speed is rapidly decelerated to make contact with the ground very gently to reach a certain depth, and then normal Teps control is automatically performed. A speed throttle device (referred to as decera control) is used. And, such control has been generally adopted conventionally, and is carried out by inserting a throttle valve into an oil passage for returning the pressure oil in the lift cylinder (8) into the tank. It should not be limited.

When a ground work machine (2) such as a rotary towed by the tractor (1) having such an electrohydraulic mechanism is operated for depth work and decera control, rotary work is performed. When using the position lever (I ₁ ) or the lifting switch (10) to raise the lift arm (3) above the ground surface by about 65 degrees or more, that is, when the lift arm (3) rises up to about 65 degrees. When the lift arm (3) is raised within a range of about 5 degrees below the position and then lowered from that position to the inside of the cultivated soil of a certain depth, the ground work machine (2) is controlled by the de-sera control.
To lower. Then, the descending speed of the ground work implement (2) is gradually decelerated so as to become the minimum at the ground contact position, and gradually increases when it becomes below the ground contact position, based on the detection of the tilling depth sensor (S ₂ ). The control unit (11) is provided so that the depth control is started at a point lower than the descending speed by the depth control. A program for such an operating procedure is incorporated in advance in the control section (11) as shown in the flow chart of FIG.

Thus, the descending speed by the de-sera control and the descending speed by the depth control are shown in the graphs of FIGS. 3A and 3B, respectively. The descending speed by the depth control shown in FIG. Immediately after that, it reaches the target point of constant plowing depth more slowly. That is, the rear cover (17) of the ground work machine (2)
After touching the ground, the descending speed by the depth control changes rapidly and reaches the target point of the working depth. Moreover, the same figure (A)
The descending speed by the de-sera control shown in (1) is extremely slow near the ground so that the descending speed is minimized at the grounding position, and gradually increases after the grounding. Therefore, as shown in FIG. 4 showing the descending speed by the de-sera control and the descending speed by the depth control, when descending from the above-mentioned raised position of the ground working machine (2) by the de-sera control, the ground working machine is used. At the point of contact (2) (almost immediately before), the speed is gradually reduced so that the descending speed is minimized. When that happens,
By the de-sera control, the dashing of the ground work machine (2) can be prevented. Therefore, the descending speed is gradually increased from this point, and the intersection point with the curve of the descending speed by the depth control shown by the chain line in the figure ( From 0), the target cultivating depth is slowly reached by changing over to the depth control curve. Thus, such an operating procedure is fully understood by the flow chart shown in FIG. 5 as described above. Especially, at the step, the position of the ground working machine (2) depends on its descending speed. If it is below the minimum position of the descending speed, it is judged whether it is above or below the minimum position.If the position is below the minimum position of the descending speed, whether the descending speed by the de-sera control is higher than the descending speed by the depth control at the next step. If it is large, the flag is set during depth control in step, and the descending speed and direction are set by the working depth sensor (S ₂ ) in step, and the rotary work is performed by normal depth control. Therefore, the transition is carried out extremely smoothly, which contributes to the improvement of workability.

〔The invention's effect〕

As described in detail in the above-mentioned one embodiment, the present invention, in the control of simultaneously operating the de-sera control and the depth control (rotary tilling work), hoists the ground work machine to the vicinity of the upper limit of the lift arm and grounds from this position. It is made to descend quickly to the vicinity, and the descending speed is gradually reduced so that the descending speed is minimized at the grounding point to make contact with the ground. Therefore, it is possible to prevent the dashing of the ground working machine such as the rotary, and accelerate the descending speed again from this ground contact point to switch to the depth control curve from the point where it intersects with the depth control curve and slow down to the target plowing depth control. Come to reach. That is, the descending speed by the de-sera control is compared with the descending speed by the depth control, and when the descending speed by the de-sera control becomes higher than the descending speed by the depth control, the de-sera control shifts to the depth control. The effect of the de-sera control can be fully exerted so that the operation by the depth control is not delayed or delayed, and accordingly, the defect that the rotary etc. becomes too deep can be eliminated and the great effects of various kinds are achieved. It is an invention to play.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a control circuit diagram, FIG. 2 is a side view of a tractor, and FIGS. 3 (A) and 3 (B) are graphs of respective descending speeds by decera control and depth control. , FIG. 4 is a graph for explaining the transition from the decera control to the depth control, and FIG. 5 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) …… Lift switch (11) …… Control unit, (12) …… Lift drive unit (13)… … Driving unit for lowering (14) …… Proportional solenoid for raising (15) …… Proportional solenoid for lowering (16) …… Pump, (I ₁ ) …… Position lever (I ₂ ) …… Plumage depth setting device, (S ₂ ) …… Plowing depth sensor (S ₁ ) …… Lift arm angle sensor

Claims (1)

[Claims] 1. A tillage depth sensor for detecting the tilling depth of a ground working machine, which is provided so as to be vertically movable by a hydraulic lifting mechanism, and a tilling depth setting device for setting the tilling depth and a sensor for detecting an angle of a lift arm. Having a control unit configured to control up and down the hydraulic lifting mechanism to perform a lifting operation according to the difference between the detection value of the working depth sensor and the setting value of the working depth setting device, and When the ground working machine is performing the working depth by the depth control that is performed according to the difference between the detection value of the working depth sensor and the setting value of the working depth setter, the position lever or the elevating switch is used to raise the vicinity of the upper limit. After raising the ground work implement to the position, cut the depth control and lower the ground work implement.When lowering the ground work implement by the de-sera control, the descending speed is minimum near the position where the ground work implement touches the ground. Gradually so that In the descending speed control device which is adapted to be grounded at a high speed, the descending speed by the depth control based on the detection of the plowing depth sensor is gradually increased when the position is below the grounding position, and the descending speed by the decera control. A control unit configured to start the depth control at a smaller point is provided, and an ascending proportional solenoid valve and a descending proportional solenoid valve are each excited by a command from the control unit, and a hydraulic lifting mechanism is provided. A de-sera control device for a ground work machine, which is configured to operate.