JPS63126403A - Automatic control apparatus of tractor working machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a device for controlling the plowing depth and horizontal inclination angle of a working machine such as a rotary tiller mounted on an agricultural tractor to a constant value.

(B) Prior Art Conventionally, it is known that a working machine is attached to the rear of a tractor, and a plowing depth sensor and an inclination sensor are attached to the working machine to perform plowing depth control and inclination control. For example, Japanese Patent Application Laid-Open No. 117705/1983.

(c) Problems to be Solved by the Invention In the prior art, the left and right tilting of the work implement is performed by an angle control cylinder provided on one lift link, and the pivot point of the other lift link is the rotation center. This is the result.

Therefore, when plowing depth control and inclination control are operated at the same time, if one of the running wheels falls into a depression on the ground surface or rides on a protrusion, the finished state of the work machine will be uneven.

For example, when the angle control hydraulic cylinder is installed on the right side of the rotary tiller for horizontal control, if the right running wheel falls into the recess (Fig. 5), while raising the right side to control the inclination angle, Since the rear cover, which is the plowing depth sensor, rotates upward, a signal is sent that the plowing depth is deep, and the plowing depth control cylinder in the hydraulic case of the entire working machine is raised. However, in reality, simply raising the right side of the work equipment will make it level. In such a case, in the conventional structure, the working machine is lowered again after it becomes horizontal, so the plowing depth is not constant during that time and the finish is poor.

Therefore, the operating speed and dead zone width of the tillage depth control cylinder, the operating speed and dead zone width of the angle control cylinder, etc. should be adjusted in consideration of the case where either the left or right falls into a recess or rides on a convex portion. It is necessary to switch accordingly.

(d) Means for solving the problem In view of the above points, the present invention is constructed as follows.

In a device that is equipped with both plowing depth control and left/right tilt angle control of a working machine, the signal to the plowing depth control cylinder that rotates the lift arm and the signal to the angle control cylinder provided on one side of the lift link are In the case where the two signals are transmitted at the same time, a judgment mechanism is provided for both signals, and the width of the dead zone for tillage depth control is automatically switched based on the judgment result.

Furthermore, the system is configured to automatically switch the operating speed of the plowing depth control cylinder based on the judgment.

Further, based on the judgment, the operating speed of the angle control cylinder is automatically switched.

Further, based on the judgment, the dead zone width of the left/right tilt angle control is automatically switched.

Also, based on this judgment, the dead band width for tillage depth control, the operating speed of the tillage depth control cylinder, the operating speed of the angle control cylinder, and the dead band width for tilt angle control should be appropriately combined and automatically switched. (This is what I composed.

(E) Embodiments of the Invention The objects of the present invention are as described above, and the present invention will be described in detail based on the configuration of the embodiments shown in the accompanying drawings.

FIG. 1 is a plan view of a tractor equipped with the automatic control device of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a plan view of an operation box, and FIG. 4 is an electric circuit diagram of the automatic control device.

M is the transmission case, 7 is the rear wheel, 20 is the handle, 2
4 is a seat. Mission case M at the rear of the tractor
A hydraulic case N is placed on top, and lift arms 8 are protruded from the hydraulic case N, with a lift link 13L at the tip.
・13R is pivotally connected. The lift arms 8, 8 are rotated by expansion and contraction of a plowing depth control cylinder (not shown) in the hydraulic case N, and are expanded and contracted by switching a hydraulic pressure switching valve 17 provided on the side. The hydraulic switching valve 17 is controlled and switched by a lift switch 10 and a control device, which will be described later. Further, a lift angle sensor 4 is disposed at the rotation base of the lift arms 8, 8, and detects the rotation angle of the lift arms 8, 8. An angle control cylinder 26 is interposed on one side of the lift link (the right side in this embodiment), and is expanded and contracted under control by another hydraulic switching valve disposed in the same area as the hydraulic switching valve 17. The rotary tiller R connected to the rear end of the rotary tiller R is tiltable.

The power to the rotary tilling device R is provided by the mission case M.
The signal is transmitted to the gear box 22 via the PTO shaft 2, the 3 universal joints 8, and 8 that protrude from the first surface. A rear cover 1 pivotally supported at the rear of the rotary tillage device R serves as a sensor for detecting the plowing depth, and rotation of the rear cover 1 is controlled via a sensor wire 12 arranged on the side of the hydraulic case N. The plowing depth is inputted to the plowing depth control sensor 5. The plowing depth control sensor 5 is composed of a potentiometer or the like. Further, a tilt angle sensor 27 consisting of a rotary encoder or the like is placed on the tilling cover 29 of the rotary tilling device R.
The left and right angle of inclination is being detected. Further, a main unit sensor 42 is arranged on the body side of the tractor, and transmits a signal that is used as a target for comparison control when the working machine is brought into alignment with the tractor and brought into a normal state.

A traveling speed change lever 3 and a position lever 2 through which the operator manually sets the height of the rotary tilling device R are arranged on the side of the seat 24, and the base of the traveling speed change lever 3 indicates a state in which the speed has been changed to the reverse position. A back switch 19 for detection is disposed, and a position sensor 6 for displaying the set value is disposed at the pivot base of the position lever 2.

Further, an operation box 11 is fixedly installed at the rear of the dashboard 25, and on the operation box 11, as shown in FIG.
0, Tilling depth setting dial 9 for setting the tilling depth, Lifting switch 1 for manually raising and lowering the rotary tilling device R
0, a rising lamp 31 that indicates that the movement is rising, and a sensitivity switching dial 32 that sets the sensitivity of the rising and falling speed. An automatic/manual changeover switch 33 for tilt control, a manual lever 34 for manually performing tilt control, a swing dial 35 for setting the tilt angle, a mode changeover switch 36 for selecting various control modes, and a switch after selection. A mode display lamp 37 is provided to display the mode.

An auto-off switch 28 is provided at the "off" position when the tilling depth setting dial 9 is turned all the way to "deep", and when the tilling depth setting dial 9 is turned to this position, manual operation is performed.

These switches, sensors, etc. are connected to a controller 16 as shown in FIG. Solenoids 41a and 41b attached to the hydraulic switching valve of the control cylinder 26 are operated to perform lifting, tilting, lamp display, etc.

(F) Function of the Invention The present invention uses the rear cover 1 as a tillage depth control sensor, transmits a signal to the tillage depth control sensor 5, extends and retracts the tillage depth control cylinder in the hydraulic case N, and lifts the lift arms 8 and 8. By moving up and down, plowing depth is automatically controlled.

In addition, in the left and right tilt control, a signal is obtained from the tilt angle sensor 27, and control is performed by expanding and contracting the angle control cylinder 26 installed in one of the lift links, and both plowing depth control and angle control are operated at the same time. The present invention relates to a control device that may be provided.

The angle control cylinder 26 installed on one of the lift links 13L is expanded and contracted to control the horizontal inclination angle of the work equipment, so the rear cover 1 also inclines, and normally it lands horizontally on the soil surface. If the rear cover 1, which serves as a sensor for controlling the plowing depth, is tilted, an incorrect plowing depth signal will be detected.

Figure 5 is a rear view of the tractor's right wheel stuck in the groove and the right side of the implement is buried; Figure 6 is the tractor's left wheel stuck on a hill and the left side of the implement is floating. Rear view, Figure 7 is a rear view of the tractor's left wheel falling into the groove and the left side of the work equipment being buried; Figure 8 is a rear view of the tractor's right wheel running up a hill and the right side of the work equipment being buried. FIG. 9 is a rear view of the vehicle in a raised state, and is a list of selection control elements in the four postures described above.

The drawings in the above state are all explained on the premise that the angle control cylinder 26 is interposed in the right lift link 13R.

The states in Figures 5 and 7 and the states in Figures 6 and 8 are as follows:
Since the positions are symmetrical, it would seem that the problem could be solved with similar control, but since the angle control cylinder 26 is only installed on the right lift link 13R, it is not possible to perform the same control. be.

In the end, it is necessary to change the control state depending on each of the cases shown in FIGS. 5, 6, 7, and 8.

The drive map changes to A- according to the four states shown in FIGS. 5 to 8.
It is predetermined as B-C-D.

In FIG. 9, a list shows what kind of control is performed for each state.

That is, drive map A is selected from the state in which the right wheel of the tractor is stuck in the groove and the right side of the working machine is buried, as shown in FIG.

In this case, if you want to return the state to the normal state, reduce the angle control cylinder 26, raise the right side of the work implement, and return it to its original position. There is no need to expand or contract. Select "Raise" for the plowing depth control cylinder, and press the angle control cylinder 26.
selects "lower right" and gives priority to angle control.

Also, since the plowing depth control cylinder does not need to move much, the operating speed is set to "slow".

In addition, in order to prevent the movement of the angle control cylinder 26 from becoming unstable due to excessive elevation and descent of the tillage depth control cylinder, the width of the dead zone of the tillage depth control sensor 5 is set to "wide" and controlled to stabilize quickly. That's what I do.

Furthermore, since the operating speed of the angle control cylinder 26 is to raise the working machine that has dug into the ground, the degree of burying is large and rapid correction cannot be made, so "slow" is selected.

Next, when the left wheel of the tractor as shown in Fig. 6 rides on a small hill and the left side of the work equipment is lifted up,
Drive map B is selected according to the flowchart.

In this case, since the work equipment is floating, simply reducing the angle control cylinder 26 will cause the work equipment to rise. Therefore, at the same time as the angle control cylinder 26 is raised to the right, the plowing depth control cylinder is ``Lowering'' is necessary.

In addition, the plowing depth control cylinder has a large descending range, and in order to quickly correct the floating state, the operating speed is set to "fast".

Furthermore, the width of the dead zone of the plowing depth control sensor 5 is selected to be "narrow", which is the one with higher accuracy, since its position is mainly determined by the expansion and contraction of the plowing depth control cylinder.

In addition, the operating speed of the angle control cylinder 26 is such that the working machine is not buried underground, so even if the angle is quickly corrected,
We choose "fast" because there are no negative effects.

Next, as shown in FIG. 7, when the left wheel of the tractor falls into the groove and the left side of the work implement is buried, drive map C is selected.

In this case as well, if only the angle control cylinder 26 is operated to "lower to the right", the entire working machine will be removed, so the "raise" of the tillage depth control cylinder is also used for control. There is a need.

In addition, since the reduction range in which the plowing depth control cylinder moves is large, it must be operated quickly, and the operating speed is "fast".
choose.

Furthermore, since the position is mainly determined by the position of the plowing depth control cylinder, the width of the dead zone of the plowing depth control sensor 5 is selected to be "narrow", which is the one with higher accuracy.

In addition, since the angle control cylinder 26 is highly buried in the working machine at this time, if the inclination is corrected immediately, the working machine will be strained, so the "slow" operating speed is selected.

Next, when the right wheel of the tractor rides on a hill and the right side of the working machine is lifted up as shown in FIG. 8, drive map D is selected.

The left side of the work equipment is in a position close to its normal state, and the normal state can be obtained by simply operating the right angle control cylinder 26 "down to the right," so there is no need to change the plowing depth control cylinder that much. Instead, the angle control cylinder 26 is set to "lower right" and the plowing depth control cylinder is selected to "lower".

In addition, since the plowing depth control cylinder hardly changes, the operating speed is selected to be "slow".

In addition, the width of the dead zone of the plowing depth control sensor 5 is set so as not to adversely affect the inclination control by the angle control cylinder 26.
Choose "wide".

In addition, since the angle control cylinder 26 has a low degree of burying of the working machine, it does not damage the working machine, and a "fast" operating speed is selected.

In the description of FIG. 9, the description about the dead zone width of the angle control cylinder 26 is omitted, but the dead zone width of the angle control cylinder 26 is "wide" like the dead zone width of tillage depth control. and "narrow".

The above selection of drive maps A-B-C-D is performed according to the flowchart shown in FIG.

In FIG. 9, when a "raise" command is input to the plowing depth control sensor 5 whose sensor is the rear cover 1 after the control starts, that is, when a part of the work implement is buried too much,
Next, a signal from the inclination angle sensor 27 causes the horizontal state to collapse, and it is determined whether a "right up" command or a "right down" command has been issued.

As a result of this judgment, if the plowing depth control sensor 5 issues a command to "raise" and the inclination angle sensor 27 issues a command to "raise to the right", the drive map A will be used when the right wheel falls into the groove, as shown in Figure 5. It is.

Next, when the plowing depth control sensor 5 is "up" and the inclination angle sensor 27 is "down to the right", this means that the left wheel has fallen into the groove as shown in Fig. 7, and the state is in drive map C. It is.

Next, if the plowing depth control sensor 5 is "down" and the inclination angle sensor 27 is "up right", this means that the left wheel has run onto a small hill as shown in Fig. 6, and drive map B is selected. It will be done.

Next, if the plowing depth control sensor 5 is "down" and the inclination angle sensor 27 is commanding "down to the right", this means that the right wheel of the tractor has run onto a small hill as shown in FIG.
Drive map D is selected.

In FIG. 9, the operating speed of the plowing depth control cylinder, the dead zone width of the plowing depth control sensor 5, and the operating speed of the angle control cylinder 26 are shown in a table (dead zone of tilt angle control). Regarding width switching, it is based on the dead zone width of plowing depth control), and it is not necessary to control all of these at once, but it is possible to control each element individually, or by combining two or three elements. It is a good choice.

FIG. 10 is a drawing showing the relationship between the lift angle equivalent deviation and the OFF time of the elevation control solenoids 40a and 40b when the operating speed of the plowing depth control cylinder is set to "fast".
FIG. 1 is a diagram showing the relationship between the lift angle equivalent deviation and the OFF time of the elevation control solenoids 40a and 40b when the operating speed is "slow".

The lift angle equivalent deviation is the angle of difference between the actual position of the lift arm 8 and the position of the lift arm 8 after the control commanded by the controller 16. Furthermore, the longer the OFF time is, the shorter the time for the pressure oil to flow through the hydraulic switching valve 17 becomes, and the operating speed of the cylinder becomes slower.

The width of the dead zone in FIGS. 10 and 11 shows the case where the dead zone width is narrow and the "standard" setting of the sensitivity switching dial 32 is selected.

The width of the dead zone is changed as shown in FIGS. 12 and 13.

FIG. 12 is a diagram showing the relationship between the lift angle and the dead zone width when the dead zone width is "wide", and FIG. 13 is a diagram showing the relationship between the lift angle and the dead zone width when the dead zone width is "narrow".

The dead zone width indicates the dead zone width in which no switching signal is generated when comparing the value of the tillage depth control sensor 5 and the value set by the tillage depth setting dial 9. Even if you move above or below the position of , it changes gradually. Lift angle O when lift arm 8 is in the highest position
The width of the dead zone is the largest at the time of , and the width of the dead zone is the smallest near the lift angle of 75 degrees when descending to the working state.

Then, the width of the dead band width is set to 3 by using the sensitivity switching dial 32 as shown in the 3 diagonal lines shown in FIGS. 12 and 13.
It can be changed in stages.

Furthermore, in the present invention, the dead zone map is
Two types, ``wide'' in the figure and ``narrow'' in Figure 13, are easily selected and automatically switched according to the drive map.A similar map is configured for tilt angle control. .

FIG. 14 shows that the operating speed of the angle control cylinder 26 is "
Swing angle deviation when “fast” and solenoid 41a/4
Figure 15, a drawing showing the relationship between the OFF times of 1b, is conversely
It is a drawing showing the relationship between the swing angle and the OFF time of the solenoids 41a and 41b in the case of "slow".

The swing angle is the deviation between the signal from the inclination angle sensor 27 and the swing dial 35.Instead of controlling the inclination to always obtain a horizontal state, the swing angle is a deviation between the signal from the inclination angle sensor 27 and the swing dial 35. In some cases, it is possible to obtain an inclined state along the .

The machine sensor 42 shown in FIG. 4 generates a signal for comparison in order to return the working machine to its normal state parallel to the tractor body.

(G) Effects of the Invention Since the present invention is configured as described above, it has the following effects.

In the case of an automatic control device that is equipped with depth control and angle control at the same time, due to the inclined posture of the work equipment, when both controls are performed in parallel at the same time, the work equipment may move up and down in a undulating manner. In other cases, it may take a long time for control to converge.

This problem may not be as serious if the aircraft gradually tilts, but it is more likely to occur if one of the wheels gets stuck in a groove or runs over a small hill.

In the present invention, by determining the tilt posture, the operating speed of the plowing depth control cylinder,
This problem can be solved by selecting the dead zone width of the plowing depth control sensor 5 and the operating speed of the angle control cylinder 26 individually or in combination.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a tractor equipped with the automatic control device of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a plan view of the operation box, Fig. 4 is an electric circuit diagram of the automatic control device, and Fig. 5 The figure shows a rear view with the right wheel of the tractor stuck in the groove and the right side of the implement buried. Figure 6 shows the rear view with the left wheel of the tractor running on a hill and the left side of the implement floating. Figure 7 is a rear view with the left wheel of the tractor in the groove and the left side of the implement is buried;
The figure shows a rear view of the tractor's right wheel riding on a small hill and the right side of the work equipment floating, Figure 9 is a list of selection control elements in the above four positions, and Figure 10 shows the plowing depth control cylinder. A drawing showing the relationship between the lift angle equivalent deviation and the OFF time of the elevation control solenoids 40a and 40b when the operating speed is "fast", and Figure 11 shows the relationship between the lift angle equivalent deviation and the elevation when the operating speed is "slow". A drawing showing the relationship between the OFF times of control solenoids 40a and 40b,
Figure 12 is a diagram showing the relationship between the lift angle and dead zone width when the dead zone width is "wide", Figure 13 is a diagram showing the relationship between the lift angle and dead zone width when the dead zone width is "narrow", and Figure 14 is a diagram showing the relationship between the lift angle and dead zone width when the dead zone width is "narrow". A drawing showing the relationship between the swing angle deviation and the OFF time of the solenoids 41a and 41b when the operating speed of the control cylinder 26 is "fast", and FIG. FIG. 16, which is a diagram showing the time relationship, is a flowchart for selecting a drive map based on the plowing depth control cylinder signal and the output signal of the angle control cylinder 26. 1... Rear cover 5... Tilling depth control sensor 8... Lift arm 9... Tilling depth setting dial 11... Operation box 13... Lift link

Claims (5)

[Claims] (1). In a device that is equipped with both plowing depth control and left/right tilt angle control of a working machine, the signal to the plowing depth control cylinder that rotates the lift arm and the signal to the angle control cylinder provided on one side of the lift link are If they are transmitted at the same time, a mechanism for determining both signals is provided, and based on the determination result,
An automatic control device for a tractor working machine, characterized in that it is configured to automatically switch the width of a dead zone in plowing depth control. (2). An automatic control device for a tractor working machine, characterized in that it is configured to automatically switch the operating speed of a plowing depth control cylinder based on the determination as set forth in claim 1. (3). An automatic control device for a tractor working machine, characterized in that it is configured to automatically switch the operating speed of the angle control cylinder based on the determination set forth in claim 1. (4). An automatic control device for a tractor working machine, characterized in that the automatic control device for a tractor working machine is configured to automatically switch the width of a dead zone in left and right tilt angle control based on the determination as set forth in claim 1. (5). Based on the judgment described in claim 1, the width of the dead zone for tilling depth control, the operating speed of the tilling depth control cylinder, the operating speed of the angle controlling cylinder, and the dead zone width of tilt angle control are appropriately combined. An automatic control device for a tractor working machine, characterized in that it is configured to automatically switch.