JP2539037Y2 - Inclination control device for working unit in work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tilt control device for a working unit in a working vehicle such as a tractor.

[Problems to be Solved by the Related Art and the Invention] In general, in this type of working vehicle, the working unit at the ascending position is returned by returning the left-right inclined posture of the working unit to the parallel posture based on the rising of the working unit. There is a type which performs so-called parallel return control for preventing interference between the vehicle and the traveling body and interference between links in the lifting link mechanism.

By the way, in work in which the working part is greatly inclined, such as on a sloped work or plow work, there is a concern that the working part that has returned to the parallel state will not return to the original inclined posture when the work is resumed, and the work accuracy will be reduced. For this reason, the parallel return control is actually released, but in this case, it is impossible to prevent the occurrence of interference at the ascending position.

Therefore, when canceling the parallel return control, it is conceivable to restrict the inclination setting range of the working unit to a safe inclination range that does not cause interference. Is limited.

[Means for Solving the Problems] The present invention has been conceived in view of the above-described circumstances and to provide an inclination control device for a working unit in a working vehicle that can eliminate these disadvantages. Then, the inclination control unit for controlling the left-right inclination posture of the working unit,
A work vehicle provided with parallel return control means for returning a horizontally inclined working part to a parallel posture based on the rise of the working part, and parallel return control releasing means for releasing the parallel return control based on a predetermined operation. In the tilt control unit, further, when there is a command to raise the working unit to the non-working position while the parallel return control is cancelled, it is determined whether the working unit tilt is out of a preset safety tilt range. It is characterized in that inclination posture correction control means for judging and immediately correcting the working unit posture to a safe inclination posture within the safe inclination range based on the result of the judgment that it is deviated is provided.

According to the present invention, with this configuration, it is possible to reliably prevent the interference at the time of ascending without restricting the inclination setting range at the time of canceling the parallel return control.

Next, an embodiment of the present invention will be described with reference to the drawings.
In the drawing, reference numeral 1 denotes a traveling body of a tractor, and a working unit is provided at a rear portion of the traveling body 1 through a three-point lifting link mechanism 4 including a single top link 2 and a pair of left and right lower links 3. 5 is connected so as to be able to move up and down, and the working unit 3 is moved up and down by a vertical swing of a pair of left and right lift arms 7 accompanying expansion and contraction of a hydraulic cylinder 6, while a left and right lift rod connecting the lift arm 7 and the lower link 3. Although the left and right are inclined by the expansion and contraction of the lift cylinder 9 which constitutes one of the components 8, all of these basic configurations are the same as the conventional one.

Reference numeral 10 denotes a side panel disposed on the side of the driver's seat 11. The side panel 10 includes a shift lever 12 for performing forward / reverse switching and the like, and an elevating operation lever for performing an elevating operation of the working unit 5. 13, a raising / lowering operation switch 14, a cultivation depth setting volume 15 for setting the cultivation depth of the cultivation depth automatic control, an automatic switching switch 16 for changing the automatic control, and a raising regulation for setting the upper limit of the working unit 5. Setting volume 17, tilt setting volume 1 for performing tilt setting for automatic tilt control
8, a mode switching switch 20 for performing control mode switching of the control unit 19 described later, sensitivity adjustment switches 21 and 22 for adjusting the sensitivity of the automatic control, and a circular arc having a center substantially at the tilling claw shaft 5a. Operating tools such as a rear cover manual switch 24 for manually operating the rotatable rear cover 23 and a lift arm manual switch 25 for manually operating the lift arm 7 are provided.

The control unit 19 is configured using a so-called microcomputer (CPU, ROM, RAM) or the like, and is disposed below the side panel 10. The control unit 19 receives an operation signal from the operating tools. At the same time, a lever angle detection sensor 26 for detecting the lever angle of the lifting operation lever 13, a reverse operation detection switch 27 for detecting that the shift lever 12 has been operated backward, and an arm angle detection sensor for detecting the swing angle of the lift arm 7 28, cylinder length detection sensor that detects the cylinder length of lift cylinder 9
29, detection signals are input from sensors such as an inclination sensor 30 for detecting the left-right inclination of the traveling machine 1 and a tillage depth detection sensor 31 for detecting the swing angle of the rear cover 23, and a determination is made based on these input signals. Thus, an operation signal is output to an actuator such as the hydraulic cylinder 6, the lift cylinder 9, and the like. That is, in the control unit 19, manual lifting control for raising and lowering the working unit 5 based on the operation of the lifting operation lever 13 and the lifting operation switch 14, the set value of the plowing depth setting volume 15 and the detection value of the plowing depth detection sensor 29 are performed. Automatically raising and lowering the working unit 5 based on the plowing depth control, automatically raising the working unit 5 based on the reverse operation of the machine, reverse control for raising the working unit 5, parallel return switching control, parallel return control, safety tilt return described later. Various controls such as control and automatic tilt control are performed.

The parallel return switching control is a control for turning ON / OFF the parallel return control for returning the working unit 5 to the parallel posture based on the rising of the working unit, but this control is not based on a dedicated switching switch. On / off switching of the parallel return control is performed based on the switching position of the mode switching switch 20. That is, whether or not the parallel return control is necessary for each mode (each work machine) is determined in advance, and the parallel return control is automatically turned on and off automatically at the same time as the switching operation of the mode switching switch 20. I'm sorry.

On the other hand, the safety tilt return control is performed when the parallel return control is released.
When a lift arm elevating command is output by manual elevating control or reverse elevating control, it is determined whether the lift cylinder 9 is out of a preset safety tilt range. Is extended and retracted to within the safe inclination range. That is,
Even when the parallel return control is released, when the working unit 5 is raised to the non-working position, a safety inclination that can avoid interference between the working unit 5 and the traveling machine body 1 and interference between the links in the lifting link mechanism 4. The inclined posture of the working unit 5 is returned to the posture. In addition, the return operation to the safe inclination posture is not performed after the working unit 5 has been raised to the predetermined height, but is immediately performed based on the output of the lift arm lifting command in the manual lifting control or the reverse lifting control. Therefore, the working unit 5 can be surely returned to the safe inclination range before reaching the highest position, so that the interference can be prevented.

The automatic tilt control calculates the target cylinder length of the lift cylinder 9 based on the average value of the past n times of the tilt sensor value and the tilt set volume value, and then compares the target cylinder length and the detected cylinder length with a predetermined dead zone. By extending and retracting the lift cylinder 9 to match with the width α,
Although the inclination posture of the working unit 5 is maintained constant regardless of the change in the left-right inclination of the traveling body 1, the sensitivity adjustment in the control is not performed by the change of the dead zone width α.
This is performed by increasing or decreasing the number n of averaged samples of the inclination sensor value. That is, when the sensitivity adjustment switch 22 is operated to the sharp side, the control sensitivity is sharpened by reducing the number of averaged samples n, and the sensitivity adjustment switch 22 is operated.
Is operated on the dull side, the control sensitivity is made dull by increasing the number of averaged samples n.

In the embodiment of the present invention configured as described above, even if the parallel return control is cancelled, when the working unit 5 is raised, it is determined whether the working unit inclination is out of the safe inclination range, If it is determined that the work unit 5 is in the safe inclination range, it is possible to reliably prevent the work unit 5 from interfering with the traveling machine 1 and the link between the links in the lifting link mechanism 4. Therefore, as in the case where the inclination setting range of the working unit 5 is restricted within the safe inclination range where there is no fear of interference in the parallel return control released state, the inclination is not insufficient in the levee breaking operation or the like, and the entire inclination is not reduced. As a result, the inclination setting range can be used effectively, and as a result, the inconvenience of restricting the type of work can be eliminated and the versatility can be improved.

In addition, the returning operation to the safe inclination posture is performed immediately based on the output of the lift arm lifting command in the manual lifting control or the backward lifting control, without being performed based on the working unit 5 being raised to the predetermined height. Therefore, there is no trouble that the return to the safe inclination posture is not in time,
It is possible to quickly and surely return the working unit 5 to the safe tilting posture while reaching the highest position, thereby reliably preventing the interference.

Further, in the embodiment, the ON / OFF switching of the parallel return control is performed based on the switching operation of the mode switching switch 20, so that it is not necessary to provide a specially-dedicated switching switch. It is possible to reduce the number of points, or it is not necessary to perform the switching operation of the parallel return control in particular, so that it is possible to save labor. In addition, in this case, it is extremely convenient that the mode switching error can be recognized by confirming whether or not the working unit 5 returns to the parallel state.

Further, the sensitivity adjustment in the automatic inclination control is performed by increasing or decreasing the number n of averaged samples of the inclination sensor value without changing the dead band width α as in the related art, so that the dead band width α is increased. As a result, a reduction in work accuracy due to a decrease in sensitivity can be suppressed as much as possible as compared with a conventional device that prevents frequent operations and a so-called hunting phenomenon, and control can be simplified.

[Effects] In summary, since the present invention is configured as described above, even if the provisional parallel return control is cancelled, if there is a command to raise the working unit to the non-working position,
Based on the determination that the working unit inclination is out of the preset safe inclination range, the working unit posture is immediately corrected to a safe inclination posture within the safe inclination range. That is,
At the ascending position, it is possible to prevent a problem that interference between the working unit and the traveling machine body and interference between links in the elevating link mechanism occur. Therefore, the entire inclination setting range can be used effectively without causing the inclination to be insufficient in the levee collapse work, such as restricting the inclination setting range of the working unit within the safe inclination range when the parallel return control is released. As a result, it is possible to solve the problem that the type of work is restricted. Moreover,
The correction to the safe tilt position is not performed based on the fact that the working unit has risen to the predetermined height, but is performed immediately after the command to raise the working unit to the non-working position. The working unit posture can be corrected to the safe tilt posture before reaching the highest position without a problem that the above-mentioned interference occurs due to the return being delayed.

[Brief description of the drawings]

The drawings show an embodiment of a working unit inclination control device in a working vehicle according to the present invention, wherein FIG. 1 is a side view of a tractor, FIG. 2 is a rear view of the same, and FIG. FIG. 4 is a block diagram showing an outline of a control mechanism, FIG. 5 is a flowchart showing a main routine of control contents, FIG. 6 is a flowchart showing parallel return switching control, and FIG. FIG. 8 is a flowchart of the return control, FIG. 8 is a flow chart of the safety tilt return control, FIG. 9 is a flow chart of the automatic tilt control, and FIG. 10 is a graph showing the relationship between the work unit tilt and the lift cylinder length. In the figure, 1 is a traveling body, 4 is a lifting link mechanism, 5 is a working unit, 9 is a lift cylinder, and 19 is a control unit.

Claims (1)

(57) [Scope of request for utility model registration] A tilt control unit for controlling a left-right tilting posture of the working unit; a parallel return control means for returning the left-right tilting working unit to a parallel posture based on a rise of the working unit; A parallel return control canceling means for canceling the work based on the command, the tilt control unit further includes a command to raise the working unit to the non-working position during the parallel return control cancellation. A tilt position that determines whether the working unit tilt is out of a preset safety tilt range, and immediately corrects the working unit position to a safe tilt position within the safe tilt range based on the determination result that it is out of range. An inclination control device for a working unit in a work vehicle, comprising a correction control unit.