JPH0761203B2 - Tractor-Work machine automatic control device - Google Patents

Description

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

(B) Conventional Technology It has been conventionally known that a working machine is mounted on the rear part of a tractor and a working depth sensor and a tilt sensor are attached to the working machine to control the working depth and the tilt. For example, it is as disclosed in JP-A-56-117705.

(C) Problems to be Solved by the Invention In the prior art, the work machine is tilted left and right by an angle control cylinder provided on the lift link on one side, and the pivot point of the lift link on the other side is rotated. It is at the center.

Therefore, when the plowing depth control and the tilt control are operated at the same time, one of the running wheels falls into a recess on the ground surface, or
When riding on the convex part, the finished state by the working machine was uneven.

For example, when the angle control hydraulic cylinder is mounted on the right side of the rotary tiller in horizontal control, and the right running wheel falls into the recess (Fig. 5),
While raising the right side for tilt angle control, the rear cover, which is the working depth sensor, is rotating upward, so a signal is issued that the working depth is deep, and the working machine as a whole is controlled in the hydraulic case. Raise the cylinder for use.

However, in reality, it will be horizontal only by raising the right side of the work machine. In such a case, in the conventional configuration, the working machine is leveled and then lowered again, so that the tilling depth is not constant and the finish is poor until then.

Therefore, the operating speed and dead band width of the working depth control cylinder, and the operating speed and dead band width of the angle control cylinder should be considered in consideration of the case where either the left or right falls into the concave part or when riding on the convex part. It is necessary to switch according to.

(D) Means for Solving the Problem In view of such a point, the present invention is configured as follows.

In the device equipped with both the working depth control of the working machine and the horizontal tilt angle control, the signal to the working depth control cylinder that rotates the lift arm and the signal to the angle control cylinder provided on one of the lift links are When the signals are transmitted at the same time, a determination mechanism for both signals is provided, and the dead zone width of the tilling depth control is automatically switched based on the determination result.

Further, the working speed of the tilling depth control cylinder is automatically switched based on the above judgment result.

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

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

Further, based on the above judgment result, the dead zone width of the plowing depth control,
The working speed of the tilling depth control cylinder, the working speed of the angle control cylinder, and the dead band width of the tilt angle control are appropriately combined and automatically switched.

(E) Embodiment of the Invention The object of the present invention is as described above, and the structure of the present invention will be described based on the structure of the embodiment 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 a mission case, 7 is a rear wheel, 20 is a steering wheel, and 24 is a seat. A hydraulic case N is placed on the transmission case M at the rear of the tractor, lift arms 8 and 8 are projected from the hydraulic case N, and lift links 13L and 13R are pivotally connected to the tips.

The lift arms 8 and 8 are rotated by expansion and contraction of a tilling depth control cylinder (not shown) in the hydraulic case N, and expanded and contracted by switching the hydraulic switching valve 17 provided on the side surface.

The hydraulic pressure switching valve 17 is switched by being controlled by the lifting switch 10 and a control device described later.

Further, the lift angle sensor 4 is arranged at the rotation base of the lift arms 8 and 8, and the rotation angle of the lift arms 8 and 8 is detected. An angle control cylinder 26 is provided on one side of the lift link (the right side in this embodiment), and the lower link is controlled to expand and contract by another hydraulic pressure switching valve arranged at the same portion as the hydraulic pressure switching valve 17. The rotary tiller R, which is connected to the rear end of 14, is tiltable.

Power to the rotary tiller R is transmitted from the PTO shaft 23 protruding from the rear surface of the mission case M to the gear box 22 via the universal joint 18.

Rear cover 1 pivotally supported at the rear of the rotary tiller R
Plays the role of a sensor for detecting the working depth, and the rotation of the rear cover 1 is input via a sensor wire 12 to a working depth control sensor 5 arranged on the side of the hydraulic case N.

The plowing depth control sensor 5 is composed of a potentiometer or the like. Further, a tilt angle sensor 27 composed of a rotary encoder or the like is mounted on the tilling cover 29 of the rotary tiller R to detect the right and left tilt angle of the rotary tiller R.

Further, the machine sensor 42 is arranged on the machine side of the tractor, and sends a signal to be subjected to comparison control when the working machine and the tractor are made to coincide with each other and in a normal state.

Then, on the side of the seat 24, a traveling gear shift lever 3 and a position lever 2 for the operator to manually set the height of the rotary tiller R are arranged, and at the base of the traveling gear shift lever 3, a state in which the gear is shifted to a reverse position is provided. A back switch 19 for detecting is arranged, and a position sensor 6 for detecting a set value thereof is arranged at the rotation base of the position lever 2.

Further, an operation box 11 is fixedly mounted on the rear part of the dashboard 25, and as shown in FIG.
Level indicator 30 that indicates the working depth of the rotary tiller R, tilling depth setting dial 9 that sets the reverse movement, lift switch 10 for manually raising and lowering the rotary tiller R, and a rising lamp that indicates that it is rising 31, a sensitivity switching dial 32 for setting the sensitivity of the lifting speed, an automatic / manual switch 33 for tilt control, a manual lever 34 for manually performing tilt control,
A swing dial 35 for setting an inclination angle, a mode changeover switch 36 for selecting various control modes, and a mode display lamp 37 for displaying the selected mode are provided.

In addition, an automatic off switch 28 is provided at the "off" position where the plowing depth setting dial 9 is fully turned to the "deep" side, and when the plowing depth setting dial 9 is turned to this position, a manual operation is performed.

These switches, sensors, etc. are connected to the controller 16 as shown in FIG. 4, and the operation of the controller 16 causes the solenoids 40a, 40b for raising and lowering control attached to the hydraulic switching valve 17 for the working depth control cylinder, and the angles. The solenoids 41a and 41b attached to the hydraulic pressure switching valve of the control cylinder 26 are operated to move up and down, incline, and display lamps.

(F) Operation of the invention In the present invention, the rear cover 1 is used as a sensor for controlling the working depth, a signal is transmitted to the working depth control sensor 5, and the working depth control cylinder in the hydraulic case N is expanded / contracted to lift arms 8,8. By rotating up and down, the plowing depth is automatically controlled.

Moreover, in the left and right tilt control, a signal is obtained from the tilt angle sensor 27, and the control is performed by expanding and contracting the angle control cylinder 26 mounted on one lift link, and both the working depth control and the angle control are activated simultaneously. The present invention relates to a control device provided as much as possible.

Then, the angle control cylinder 26 provided on one of the lift links 13L is expanded / contracted to control the left / right tilt angle of the working machine, so that the rear cover 1 is also tilted, and is normally grounded horizontally on the soil surface. If the rear cover 1 which is a sensor for controlling the working depth is tilted on the premise that the working depth is being controlled, an erroneous working depth signal will be detected.

Fig. 5 is a rear view of the tractor on the right side of the wheel when the right side of the tractor is buried in the groove, and Fig. 6 is on the left side of the tractor when the left side of the tractor is raised. Rear view, Fig. 7 is a rear view in which the left wheel of the tractor has fallen into the groove, and the left side of the work implement is buried. Fig. 8 is the right wheel of the tractor is riding on a mound, and the right side of the work implement FIG. 9 is a list of selection control elements in the above-mentioned four postures, with the rear view showing a state in which is raised.

The drawings in the above state are all premised on the configuration in which the angle control cylinder 26 is interposed in the right lift link 13R,
It is to explain.

The states shown in FIGS. 5 and 7 and the states shown in FIGS. 6 and 8 are
Since it is a symmetrical posture, it seems that the same control can be solved, but since the angle control cylinder 26 is interposed only in the lift link 13R on the right side, the same control cannot be performed. is there.

After all, it is necessary to change the control state according to each case of FIG. 5, FIG. 6, FIG. 7, and FIG.

According to the four states of FIGS. 5 to 8, the drive map is A.
It is predetermined as B, C and D.

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

That is, the drive map A is selected from the state in which the wheels on the right side of the tractor shown in FIG. 5 are fitted in the grooves and the right side of the working machine is buried.

In this case, in order to return the state to the normal state, the angle control cylinder 26 is reduced, the right side of the working machine is raised, and if it is returned to the original state, the working depth control cylinder is not so much. There is no need to expand or contract. The tilling depth control cylinder is selected to be "raised", the angle control cylinder 26 is selected to be "to the right", and the angle control is prioritized and controlled.

Further, since the working depth control cylinder does not need to move much, the operating speed is selected as "slow".

Also, in order not to make the movement of the angle control cylinder 26 unstable by excessively raising and lowering the tilling depth control cylinder, the dead zone width of the tilling depth control sensor 5 is selected to be "wide" and controlled to stabilize quickly. To do.

Further, since the working speed of the angle control cylinder 26 raises the working machine that has penetrated into the ground, the degree of burial is large and rapid correction cannot be performed, and “slow” is selected.

Next, when the left wheel of the tractor shown in FIG. 6 rides on a small mountain and the left side of the working machine is lifted, the drive map B is selected by the flowchart.

In this case, since the work implement is lifted up, the work implement is lifted up only by reducing the angle control cylinder 26. "Lowering" is necessary.

Further, the working speed of the tilling depth control cylinder is selected to be "fast" in order to increase the descending width which is the moving width and to quickly correct the floating state.

The dead zone width of the tilling depth control sensor 5 is mainly determined by the expansion and contraction of the tilling depth control cylinder, so that the dead zone width is selected to be "narrow", which has a higher accuracy.

Since the working speed of the angle control cylinder 26 is low in the degree of burial of the working machine in the ground, even if the angle is corrected quickly, no adverse effect is produced, so "fast" is selected.

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

Also in this case, since the working machine is completely buried by only the "right lowering" operation by the angle control cylinder 26, it is necessary to simultaneously control the "up" of the working depth control cylinder. There is.

In addition, since the reduction width, which is the movement width, of the working depth control cylinder is large, it is necessary to operate immediately, and the operating speed is “fast”.
Is selected.

Further, since the position is mainly determined by the position of the tilling depth control cylinder, the dead zone width of the tilling depth control sensor 5 is selected to be "narrow" which has a higher accuracy.

Further, the angle control cylinder 26 has a high degree of burial of the working machine at this time, and if the correction is urgently made, the working machine will be overloaded. Therefore, the operating speed is selected as "slow".

Next, the drive map D is selected when the right wheel of the tractor rides on a small mountain and the right side of the work implement is raised as shown in FIG.

And the left side of the work machine is in a position close to the normal state, and by only "right lowering" the angle control cylinder 26 on the right side,
Since the almost normal condition can be obtained, the working depth control cylinder does not need to change so much, and the angle control cylinder 26
Is "down right", and the cylinder for controlling the working depth is "down"
Is selected.

Moreover, since the working depth control cylinder hardly changes, the operating speed is selected as "slow".

In addition, the dead zone width of the tilling depth control sensor 5 does not adversely affect the tilt control by the angle control cylinder 26.
Select "wide".

Further, since the angle control cylinder 26 has a small degree of burial of the working machine, the working speed is selected to be “fast” without damaging the working machine.

Although the description of the dead zone width of the angle control cylinder 26 is omitted in the description of FIG. 9, the dead zone width of the angle control cylinder 26 is “wide” like the dead zone width of the plowing depth control. And "narrow".

The selection of the drive maps A, B, C, D described above is performed according to the flowchart disclosed in FIG.

In FIG. 9, after the control is started, when the “raising” command is input to the tilling depth control sensor 5 having the rear cover 1 as a sensor, that is, when a part of the working machine is buried too much,
Next, it is determined whether the “horizontal state” is broken by a signal from the tilt angle sensor 27 and a “right-up” command is issued or a “right-down” command is issued.

If a command is issued that the tilling depth control sensor 5 is "up" and the tilt angle sensor 27 is "upright" by this determination,
As shown in FIG. 5, the drive map A is obtained when the right wheel falls into the groove.

Next, the plowing depth control sensor 5 is "up" and the tilt angle sensor
When 27 is "right-down", it means that the left wheel has fallen into the groove as shown in FIG. 7, and the state of the drive map C is reached.

Next, when the plowing depth control sensor 5 is "down" and the inclination angle sensor 27 is "upright", this is the case where the left wheel has climbed up a mountain as shown in FIG. 6, and the drive map B is selected. Is done.

Next, when the plowing depth control sensor 5 is “down” and the inclination angle sensor 27 is “down right” command, as shown in FIG. 8, it is a case where the right wheel of the tractor rides on a small mountain. D is selected.

In FIG. 9, the operating speed of the working depth control cylinder, the dead zone width of the working depth control sensor 5, and the operating speed of the angle control cylinder 26 are shown in a list (the dead zone of the tilt angle control is shown in FIG. Regarding the switching of the width, according to the dead zone width of tilling depth control), including all of these, it is not necessary to control at once, in each one of them, or by combining two elements or three elements, You can choose it.

Fig. 10 shows that the operating speed of the working depth control cylinder is "fast".
Equivalent deviation of lift angle and lift control solenoid
FIG. 11 is a drawing showing the relationship between the OFF times of the 40a and 40b, and FIG. 11 is a drawing showing the relationship between the lift angle equivalent deviation and the OFF time of the lift control solenoids 40a and 40b when the operating speed is “slow”.

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

The dead band widths in FIGS. 10 and 11 show the case where the dead band width is narrow and the "standard" sensitivity switch dial 32 is selected.

The dead band width is changed as shown in FIGS. 12 and 13.

FIG. 12 is a drawing showing the relationship between the lift angle and the dead band width when the dead band width is “wide”, and FIG. 13 is a drawing showing the relationship between the lift angle and the dead band width when the dead band width is “narrow”.

The dead band width refers to a dead band width that does not generate a switching signal when the value of the tilling depth control sensor 5 and the setting value of the tilling depth setting dial 9 are compared, and the dead band width is the lift arms 8 and 8. It also changes gradually depending on the position above and below. When the lift arm 8 has the lift angle of 0 at the highest position, the dead zone width is the largest, and is the smallest near the lift angle of 75 degrees when descending to the working state.

Further, the width of the dead zone can be changed in three steps by the sensitivity switching dial 32 as shown by the three diagonal lines in FIGS. 12 and 13.

Further, in the present invention, two types of dead zone maps, "wide" in FIG. 12 and "narrow" in FIG. 13, are prepared and automatically switched according to the drive map. A similar map is constructed for the tilt angle control.

FIG. 14 shows the swing angle deviation when the operating speed of the angle control cylinder 26 is “fast” and the OFF state of the solenoids 41a and 41b.
On the contrary, FIG. 15 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”, on the contrary.

The swing angle is a deviation between the signal from the tilt angle sensor 27 and the swing dial 35, and the tilt control is not always controlled to obtain a horizontal state, but is controlled by the swing dial 35.
As a result, a tilted state may be obtained along the field scene on the sloping land.

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

(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 has both the plowing depth control and the angle control at the same time, due to the inclined posture of the working machine, when both controls are simultaneously advanced in parallel, the working machine moves up and down so as to wavy. Alternatively, it may take a long time to focus the control.

When the body gradually inclines, this is not so much, but when one of the wheels fits in a groove or climbs a small mountain, this problem occurs remarkably.

In the present invention, in such a state, when a signal to the tilling depth control cylinder that rotates the lift arm and a signal to the angle control cylinder provided on one of the lift links are simultaneously started, A signal judgment mechanism is provided, and based on the judgment result, the working speed of the tilling depth control cylinder, the dead zone width of the tilling depth control, the dead zone width of the left and right tilt angle control,
By selecting the operating speed of the angle control cylinder 26 for each single element or in combination, it is possible to eliminate the above-mentioned control problems.

[Brief description of drawings]

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, FIG. 4 is an electric circuit diagram of the automatic control device, and FIG. The figure shows the rear view of the wheel on the right side of the tractor in the groove, and the right side of the work machine is buried. Figures and 7 are rear views of the tractor with the wheels on the left side dropped into the groove, and the left side of the work implement buried.
The figure shows the rear view of the right side of the tractor when the right wheel of the tractor rides on a small mountain, and the right side of the work implement floats up.
In the posture, a list of selection control elements, FIG. 10 shows the relationship between the lift angle equivalent deviation and the OFF time of the elevation control solenoids 40a, 40b when the working speed of the tilling depth control cylinder is set to “fast”. The drawing and Fig. 11 also show the lift angle equivalent deviation and the lift control solenoid 40 when the operating speed is "slow".
Drawing showing the relationship between a and 40b OFF time, Fig. 12 is a drawing showing the relationship between lift angle and dead zone width when the dead zone width is "wide",
Similarly, FIG. 13 is a drawing showing the relationship between the lift angle and the dead zone width in the case of “narrow”, and FIG. 14 is the swing angle deviation and the solenoid when the operating speed of the angle control cylinder 26 is “fast”.
Drawing showing the relationship between the OFF time of 41a, 41b, Fig. 15 is a drawing showing the relationship between the swing angle in the case of "slow" and the OFF time of the solenoids 41a, 41b, and Fig. 16 is the cylinder signal for controlling the working depth. 7 is a flowchart for selecting a drive map according to an output signal from 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, 26 ... angle control cylinder, A, B , C, D …… Drive map

Claims (5)

[Claims] 1. A device having both a working depth control of a working machine and a horizontal tilt angle control, wherein a signal to a working depth control cylinder for rotating a lift arm and an angle control provided on one of the lift links. When the signals to the cylinders are transmitted at the same time, a determination mechanism for both signals is provided, and based on the determination result, the dead zone width of the working depth control is automatically switched, and the automatic tractor working machine is characterized. Control device. 2. A mechanism for determining both signals when a signal to a tilling depth control cylinder for rotating a lift arm and a signal to an angle control cylinder provided on one of the lift links are simultaneously transmitted. An automatic control device for a tractor working machine, which is configured to automatically switch an operating speed of a tilling depth control cylinder based on the determination result. 3. A mechanism for judging both signals when a signal to a tilling depth control cylinder for rotating a lift arm and a signal to an angle control cylinder provided on one of the lift links are simultaneously transmitted. An automatic control device for a tractor working machine, which is configured to automatically switch the operating speed of the angle control cylinder based on the result of the determination. 4. A mechanism for judging both signals when a signal to a tilling depth control cylinder for rotating a lift arm and a signal to an angle control cylinder provided on one of the lift links are simultaneously transmitted. An automatic control device for a tractor work machine, characterized in that it is configured to automatically switch a dead band width for left / right tilt angle control based on the result of the determination. 5. A mechanism for determining both signals when a signal to a tilling depth control cylinder for rotating a lift arm and a signal to an angle control cylinder provided on one of the lift links are simultaneously transmitted. Based on the result of the judgment, the dead zone width of the tilling depth control, the working speed of the tilling depth control cylinder, the working speed of the angle controlling cylinder, and the dead zone width of the tilt angle control should be appropriately combined to automatically switch. An automatic control device for a tractor work machine characterized by being configured.