JPS62190010A - Plowing depth automatic controller of tractor - 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 an automatic tillage depth control device for controlling the tillage depth of a working machine such as a rotary tiller mounted on a tractor to a constant value.

(B) Prior Art Techniques for automatically controlling the plowing depth to a constant value using a rotary tillage device mounted on a tractor have been well known. For example, Japanese Patent Publication No. 5B-26927 and Japanese Patent Publication No. 54
This is as in Publication No.-75309.

(c) Problems to be Solved by the Invention The purpose of the present invention is that when a tractor is equipped with an automatic plowing depth control device, the operator does not have to concentrate so much on the rotary tilling device, and can rely on the automatic device. Even though the rotary tiller is in working condition, the operator shifts the gear into reverse and goes backwards, causing an accident that destroys the work equipment. This condition is particularly likely to occur in the automatic control state, ``auto mode,'' so in the present invention, when the travel gear shift lever is placed in reverse, the lift arm is automatically moved to the highest position only in the ``auto mode.'' It is configured with a ``lift-up mode when reversing'' that raises the vehicle up to the maximum height.

However, in the method of using a tractor, there are times when the soft soil after tilling is filled with soil during reverse tillage work, and the rotary tiller is moved backward at a height that does not touch the soil without raising it too much. There is also a work method in which the area of the headland is narrowed by starting plowing from that position, so in the case of "position mode" other than "auto mode", the traveling gear shift lever is set to the bank. The structure is such that even if the person enters the room, there is no need to raise the lift arm.

(d) Means for Solving the Problems The objects of the present invention are as described above. Next, the configuration for achieving the objects will be explained.

In an automatic tilling depth control device that detects the tilling depth of a work implement by a rear cover sensor 5, detects the position of a lift arm 8 by a lift angle sensor 4, and sets a target value of tilling depth by a tilling depth setting dial 9, the automatic only during control,
A "bank lift-up mode" is configured to raise and hold the lift arm 8 when the travel gear shift lever 3 is shifted to the reverse position.

(E) Structure of the Embodiment The object and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings will be explained.

FIG. 1 is a side view showing an automatic tillage depth control device for a tractor according to the present invention, FIG. 2 is a plan view of the same, and FIG. 3 is a plan view of an operation box 11 section.

The configuration will be explained with reference to FIGS. 1, 2, and 3.

A hydraulic case N is placed on top of the tractor's transmission case. Left and right lower links 14 protrude from the rear end side of the mission case M so as to be movable up and down. Further, a top link hinge 21 protrudes from the rear surface of the hydraulic case N, and a top link 15 is pivotally supported at the rear end of the top link hinge 21. The two lower links 1
4 and 14 and one top link 15, the rotary tiller R is mounted so as to be movable up and down. Power is transmitted through a bevel gear box 22 of a rotary tiller R, two PTO shafts of a hemi- sion case M, and three universal joint shafts.

The rotary tilling device R is configured to till the soil by rotating the tilling claws 7 and to level the tilled soil using the rear cover 1.

In the present invention, the rear cover 1 is also used as a sensor for detecting the plowing depth, and the vertical rotation state of the rear cover 1 is detected through a sensor wire 12 arranged on the side of the hydraulic case N. It is input to the rear cover sensor 5. In this embodiment, the rear cover sensor 5 is constituted by a potentiometer.

Further, a hydraulic cylinder and a piston are arranged inside the hydraulic case N, and lift arms 8, 8, which are moved up and down by the device, protrude rearward. Lift links 13, 13 are pivotally connected to the rear ends of the lift arms 8, 8, and the lower ends of the lift links 13, 13 are connected to the lower links 14,
It is pivoted in the middle of 14.

A lift angle sensor 4 for detecting the rotation angle of the lift arm 8 is arranged at the rotation base of the lift arm 8 .

Further, a seat 24 is arranged above the hydraulic case N, and on the side of the seat 24 there is a position lever 2 for the operator to manually set the height of the rotary tiller R.
is located.

A position setting device 6 for detecting a value set by the position lever 2 is disposed at the rotation base of the position lever 2.

Also, the controller 16 is connected between the seat 24 and the hydraulic case N.
A microcomputer, an A/D converter, etc. as a control device are arranged within the controller 16.

Further, a hydraulic switching valve 17 using a solenoid valve as a pilot valve is disposed inside or on the side of the hydraulic case N. The output signal after the control decision by the controller 16 is sent to the solenoid valve of the hydraulic switching valve 17 and fed back.

Further, a travel gear shift lever 3 for operating a forward/reverse transmission disposed inside the mission case M is rotatably arranged for speed change operation, and at the base of the travel gear shift lever 3,
A back switch 19 is arranged to detect the state in which the traveling speed change lever 3 is shifted to the reverse position.

Furthermore, an operation box 11 for automatic reverse control is fixedly installed on the lower surface of the rear part of the dash board 25. A plowing depth setting dial 9 and a lift switch 10 are arranged on the top surface of the operation box 11.

The plowing depth setting dial 9, lift angle sensor 4, rear cover sensor 5, and position setting device 6 are all constituted by potentiometers whose voltage values change when rotated.

In addition, the lift switch 10 is turned ON only when the operator operates it to the upward or downward direction, and turns ON when the operator releases it.
It is composed of switches serving as FF.

Further, an auto-off switch 28 is arranged, which is turned on when the plowing depth setting dial 9 is fully rotated in the direction of increasing depth. When the plowing depth setting dial 9 is rotated to a position other than "off", the auto-off switch 28 is OFF and in an automatic control state.

1) Operation of the embodiment Next, the operation of the automatic tillage depth control device of this embodiment will be explained with reference to the drawings shown in FIGS. 4 to 8.

Fig. 4 is a drawing showing an overview of the control flowchart, Fig. 5 is a drawing of the flowchart with parts of "position mode", "auto mode", and "lift-up mode when reversing", Fig. 6, Fig. 7, FIG. 8 is a drawing in which the entire flowchart of the present invention is divided into a first stage, a middle stage, and a second stage.

First, in FIG. 4, an overall outline of this control flowchart is shown.

That is, first, when the tractor's engine start key is turned ON, the control is started and the switches such as the auto-off switch 28, lift switch 10, and reverse switch 19 are turned on and off.
The F state is detected and stored every 811 seconds. Since the 087414 time of the switches is set to 24 mm seconds and the OFF delay time is set to 24 msec, it is stipulated that the ON-OFF state is recognized only when the ON-OFF time continues for 24 seconds. By providing the OFF delay time of 087414 hours, the effects of chattering and noise are prevented when switching is unstable.

Next, the tilling depth setting dial 9 in the operation box 11 is rotated to set the tilling depth. O in conjunction with the tilling depth setting dial 9.
The auto cut switch 28, which is turned off, is turned off, and the plowing depth value is set using the plowing depth setting dial 9. Furthermore, signals from the shaft angle sensor 4, rear cover sensor 5, and position setting device 6 are also stored.

The control mode is selected with the various signals stored.

There are the following types of control modes:

"Auto mode", "Position mode", "Lift up mode when reversing", "Safety mode"
- There are 6 modes: ``Lift-up mode'' and ``Abnormal mode.''

Then, when one of the six modes is selected and the control flow of one flowchart is completed, a self-diagnosis flowchart (S-D) and a monitor communication flowchart)C
MC) to return to the starting position again.

Selection of control mode based on each sensor value is performed automatically. Therefore, the actual operation is performed by always selecting one of the six modes mentioned above.

The entire flowchart is disclosed in the drawings from FIG. 6 to FIG. 8, and the details can be understood by following the flow, but it would be redundant to explain each flow one by one. The functions will be explained as a whole.

The "safety mode" is a mode to ensure safety when the tractor starts operating, and may be selected only at the moment the engine start key is turned on, and is selected under the following conditions.

That is, when the engine start key of the tractor engine is turned on, if the travel gear shift lever 3 is in reverse and the back switch 19 is turned on, or similarly when the engine start key is turned on, the position lever 2 This is a case where the set position is lower than the position of the lift arm 8.

i Explain the control operation when entering "safety mode". The above two conditions are dangerous if the lift arm 8 is operated as it is when the tractor starts operating, so the lift arm 8 is not rotated. That is, when the travel gear shift lever 3 enters reverse, the "reverse lift-up mode" is activated and the rotary tiller R is immediately activated.
is configured to rotate upward, and if the position lever 2 is lower than the position of the lift arm 8, the present invention is configured to lower the rotary tiller R to the position set by the position lever 2. This is because it has been done. If this control is continued as it is, an action that is not intended by the operator will suddenly occur, leading to an accident.

In order to cancel the "safety mode", it is necessary to operate the travel gear shift lever 3 to a position other than reverse, and also rotate the position lever 2 so that it is on the upward side compared to the position of the lift arm 8. . Automatic control will not start unless these operations are performed, so when the "safety mode" is entered, the operation for canceling is illustrated near the dash board or supported by an audio device.

Next, the conditions for selecting "abnormal mode" are: lift angle sensor 4, rear cover sensor 5, position setting device 6,
This mode is given priority when the plowing depth setting dial 9 and lift switch 10 generate abnormal signals and when the mode is other than the "safety mode". An abnormal value of each sensor is a case where the output value shows a value of O to 0.2v.

The method of determining an abnormality is to check the value of each sensor every 8 seconds, and once a value of 0 to 0.2V is detected, check again 400 seconds later and if it is an abnormal value,
For the first time, it is determined to be abnormal. This determination is made using a self-diagnosis flowchart (S-D) to be described later.

In the operation in the "abnormal mode", the lift arm 8 is not raised or lowered. This is to prioritize safety and prevent accidents from occurring due to unintentional sudden lifting/lowering operations. The mode is canceled when the failure of each sensor or switch is normalized.

Next, the "lift-up mode" is selected under the following conditions. That is, when the lift switch 10 disposed on the top surface of the operation box 11 is tilted upward, the "lift-up mode" is entered preferentially in cases other than the "safety mode" and "abnormal mode".

The operation in the "lift-up mode" is to raise the lift arm 8 to the highest position and hold it there. This operation occurs when the tractor reaches the edge of the field and needs to go around, and the same operation is performed by rotating the position lever 2 to the highest position, but rotating the position lever 2 is a troublesome operation. When lowering the lever after rotating, it is necessary to reliably position the position lever 2 at the position before rotating, and these operations are omitted. This mode can be canceled by tilting the lift switch 10 to the lowering side, whereby the lift arm 8 is accurately lowered to the position before being lifted, and the mode is canceled. By rotating the lift switch 10 in the upward direction, the lift arm 8 will always rise to the highest position even if the switch is released and the switch returns to the neutral position. Similarly, when the lift switch 10 is turned to the lower side, even if the switch is not held, the lift switch 10 is lowered to the position before the lift switch 10 was turned to the upper side.

Next, I will explain the conditions under which "position mode" is selected.

Move the lift arm 8 to any position using the position lever 2.
■, If the auto-off switch 28 is turned on when the "safety mode", "abnormal mode", or "lift-up mode" is not selected.

(2) When the set position of the position lever 2 is above or equal to the position of the lift arm 8. It memorizes the lift angle at this time and enters "position mode."

If the value of the plowing depth setting dial 9 is smaller than or equal to the value of the position lever 2 when the mode is set to the "position mode" in (1) or (2), the mode remains in the "position mode". Further, if the plowing depth setting dial 9 is larger than the value of the position lever 2, and if the "position mode" is larger than or equal to the value of the lift angle sensor 4 stored in step (3), the "position mode" remains.

The operation of the "position mode" is as follows. That is, the position of the lift arm 8 and the set position of the position lever 2 correspond to 1 to 1, so that when the position lever 2 is moved, the lift arm 8 is also moved accordingly. Based on the conditions of ■■, once the "position mode" is entered, the "position mode" cannot be exited unless the position lever 2 is lowered to a position below the memorized lift angle when the mode was entered. In other words, only when the operator lowers the position lever 2 below the memorized lift angle based on the operator's will, the "position mode" is activated.
Remove the button and return to "auto mode". This is also an attempt to prioritize safety. Also position lever 2
Mix control is now possible in which the previous "auto mode" switches to "position mode" as the value increases. However, the switching point of the mix control is determined by the value of the position setting device 6 and the plowing depth setting dial 9.
The point where the value of the rising position setting device 6 and the value of the lift angle sensor 4 match is taken instead of the point where the set value of .

As a result, the points at which the setting value of the plowing depth setting dial 9 and the setting value of the position lever 2 change are no longer close to each other. If the switching occurs at the position where both settings and values match. The values that the lift angle sensor 4 uses as deviation targets are replaced at close positions, causing problems such as hunting in the control and a delay in convergence. By setting the target of the switching to a value that is the intersection of the value of the lift angle sensor 4 and the value of the position setting device 6, it is possible to perform the switching at a value that is different from the value of the plowing depth setting dial 9, thereby preventing hunting and non-operation. Convergence does not occur. Also, when returning to the "auto mode", the memorized lift angle at the time of the rise is used to create the same state, and when the position lever 2 is rotated downward beyond the memorized lift angle, the "auto mode" is returned. It returns to .

Next, we will show the conditions under which "Auto mode" is selected. “Safety Mort′”・“Lift Up Mode”・
Auto-off switch 28 is OFF in any mode other than "abnormal mode"
In this case, if at least one of the following conditions is satisfied, the system becomes "auto mode".

(a), position lever 2 is in the lowest position and 1.
When it is between 5 degrees above.

(b), the setting value of position lever 2 is lift arm 8
If it is below the position.・Even if the setting value of the plowing depth setting dial 9 is greater than the setting value of the position lever 2, and the memorized value of
when it is above the position of That is, this is the case when the operator once lowers the position lever 2 and enters the "auto mode".

The operation in "auto mode" is as follows. The lift arm 8 is raised and lowered depending on the deviation between the set value of the tilling depth setting dial 9 and the detected value of the rear cover sensor 5, and the value of the rear cover sensor 5 that is fed back is in the vicinity of the set value of the tilling depth setting dial 9. The plowing depth is controlled at a constant level.

The angle of 1.5 degrees in case (a) is "auto mode"
, the width is approximately the same as the width of the fuwaza zone provided near the setting value of the plowing depth setting dial 9, and within the width of about 1.5 degrees, the values of the position setting device 6 and lift angle sensor 4 are This interval makes it difficult to clearly compare the sizes. Therefore, if the position lever 2 is between 1.5 degrees, the configuration is such that the "auto mode" is directly set without comparing the sizes of the position setter 6 and the lift angle sensor 4.

Next, the conditions under which the "reverse lift-up mode", which is the main part of the present invention, is selected are as follows: the "auto mode" is selected, the travel gear shift lever 3 is in the reverse position, and the reverse switch 19 is turned on. This is the case.

In the operation of the "reverse lift-up mode", the lift arm 8 is raised to the highest position and held. This mode cannot be entered if the auto-off switch 28 is OFF.

The release is performed by setting the travel gear shift lever 3 to a position other than reverse or by tilting the lift switch 10 to the release side.

In the present invention, the conditions for entering the "reverse lift-up mode" are as follows: when the control is in "auto mode", the traveling gear shift lever 3 is in reverse and the bank switch 19 is in the OFF position.
This is limited to when N is reached. That is, even if the travel gear shift lever 3 is moved to reverse in the "position mode", the "reverse lift-up mode" is not entered.

This point is an important technical element. In particular, accidents such as driving backwards with the rotary tiller in the lowered position and destroying it due to incorrect operation are likely to occur if you are not paying attention to the rotary tiller in "auto mode".
This kind of accident is less likely to occur in "Position Mode" because the operator has to look back many times. Therefore, there is little need to perform a lift-up operation when reversing in "position mode".

Also, as explained in the purpose section, there are regions where bank tilling is required as a special method of work, and considering the use of other working machines such as snow blowers and rear blades, it is necessary to keep this possibility open. There is.

The present invention has been constructed with these points in mind.

Next, let me explain about the self-diagnosis flowchart (SD).

The flowchart of this embodiment is repeated every 8 seconds, and each time the self-diagnosis flowchart (SD) is passed through to diagnose abnormalities in each sensor or switch. If it is determined that there is an abnormality based on the flow, the system enters the "abnormal mode" and is dealt with.

Next, the monitor communication flowchart (MC) will be explained.

The values of each sensor, the ON-OFF status of the switch, and the presence or absence of output to the solenoid valve are serially transmitted to a separate monitor every 80 msec. The monitor receives this and displays the status on the panel. The monitor is used for repairs and inspections, so it is removed unless necessary. The monitor and the controller 16 are connected using a connector on the internal board of the controller 16.

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

Firstly, even if you put the rotary tiller in "auto mode" during tilling work and forget that the rotary tiller is lowered due to a mistake and try to shift gears into reverse and go backwards, the present invention can be used. By automatically switching from ``auto mode'' to ``lift-up mode when reversing,'' the rotary tiller is raised to the highest position, so the rotary tiller will not be destroyed even when reversing. .

Second, the "lift-up mode when reversing" is activated only when the work is put into reverse when in "auto mode", and even if the work is put into reverse when in "position mode" It is not a "mode". This configuration makes it possible to perform back tilling intentionally. With this configuration, it is possible to prevent back tilling due to a mistake, and allow it when back tilling is done intentionally.
This made it possible to create a system that matched the driving psychology of the operator.

[Brief explanation of drawings]

Fig. 1 is a side view showing the automatic tillage depth control device for a tractor of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a plan view of the operation box 11, and Fig. 4 is a drawing showing an outline of the control flowchart. , Figure 5 is a flowchart showing the parts of "position mode", "auto mode", and "lift-up mode when reversing", and Figures 6, 7, and 8 are flowcharts of the entire invention. This is a drawing showing a state in which it is divided into a front stage, middle stage, and rear stage. l...Rear cover 2...Position lever 3...Traveling speed change lever 4...Lift angle sensor 5...Rear cover sensor 6...Position setting device 7...Tilling claw 8...Lift arm 9...Plowing depth setting dial 10...Lift switch 19...Back switch Applicant Yanmar Diesel Co., Ltd. Agent Patent attorney Toshibe Yano Figure 4

Claims (1)

[Claims] In an automatic tilling depth control device that detects the tilling depth of a working machine by a rear cover sensor, detects the position of a lift arm 8 by a lift angle sensor 4, and sets a target value of tilling depth by a tilling depth setting dial 9, the automatic control Only in
An automatic plowing depth control device for a tractor, characterized in that it is configured to raise and hold a lift arm when a travel gear shift lever is shifted to a reverse position.