JP3271356B2 - Tillage depth control mechanism of tractor working machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for controlling the working depth of a working machine mounted on a tractor.

[0002]

2. Description of the Related Art Conventionally, the same applicant has an electronic governor mechanism for controlling an engine and a position control mechanism for a working machine, and positions the working machine so that the detected load factor is detected by an electronic control section. The control technology has been filed. For example, Japanese Patent Application No. 3-80105.

[0003]

In the above prior art, the load is adjusted by adjusting the position of the working machine based on the load ratio detected by the electronic control unit to detect the work state.
However, in this case, the work machine is raised and lowered due to a change in load, but this is draft control controlled based on the load factor detection value, and the actual plowing depth changes more than necessary, There were inconveniences such as deterioration of the condition. The present invention is configured such that the control performed based on the load factor detection value is performed not by the draft control but by the plowing depth control.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. In a tractor having an electronic governor mechanism for controlling an engine and a depth control means for controlling a working machine according to claim 1, a load factor setting device 17 for setting a load factor by an operator is provided. 1
7 and the electronic governor mechanism GV
To control by comparing the load factor detection value A detected by the
And the load factor set value B set in the load factor setter 17
When the signal is ON, the electronic governor mechanism G
Load factor detection value A detected from V is input as a control signal
However, in the case of OFF, the load set in the load factor setting unit 17 is negative.
Intermittent control to input the signal of the load factor set value B as it is
The lift control electromagnetic valves V1 and V2 are controlled from the electronic control unit.
Then, the rotary tillage device R is moved up and down to control the tillage depth .

[0005] According to claim 2, the tiger according to claim 1 is provided.
The load factor set value B is
The smaller the time, the shorter the ON time and the longer the OFF time
On the contrary, when the load factor set value B is large, the ON time
Are controlled to be long and the OFF time is shortened .

[0006]

Next, the operation will be described. That is, since the present invention is configured as in the present invention, it is possible to control the plowing depth by the load factor detection value A even when the operation by the tractor is light. In addition, since the load factor control is intermittent control, hunting caused by a delay in the signal of the load factor detection value A can be avoided. Also, in the mechanism for controlling the plowing depth based on the load factor, the smaller the load factor, the smaller the control amount of the plowing depth control, to avoid hunting that occurs when the load factor is small,
The engine stall that occurs when the load factor is large can be avoided.

[0007]

Next, an embodiment will be described. FIG. 1 is a side view of a tractor equipped with a rotary tilling device as a working machine, FIG. 2 is a schematic diagram of a control mechanism of a cultivating depth control mechanism of the tractor working machine of the present invention, and FIG. FIG. 4 is a side sectional view of the electronic governor mechanism GV.
FIG. 5 is a side sectional view of the electronic governor mechanism GV, and FIG.
FIG. 7 is a drawing showing an example of a control map by the electronic governor mechanism GV, and FIG. 7 is a hydraulic circuit diagram of a working machine lifting mechanism B having lift lifting / lowering solenoid valves V1 and V2.

Referring to FIG. 1, the structure of the tractor will be described.
An engine E is arranged inside the hood of the tractor, and an electronic governor mechanism GV is attached to a side surface of the engine E. An accelerator lever 14 for setting the number of revolutions of the engine E by an operator is rotatably supported by a dashboard portion of the hood. An accelerator lever sensor 5 is arranged at the base of the accelerator lever 14. The accelerator lever sensor 5 detects how much the operator has turned the accelerator lever 14 and how much rotation speed the operator desires to set.

A work machine control panel 15 is provided on the side of the tractor seat.
, An automatic / manual changeover switch 8 for switching between automatic control and manual control of the work implement, a load factor setting device 6 for setting the load factor of the work implement, and setting the position of the work implement during position control. A work implement position setting device 7 is provided. The rotary tillage device R mounted on the rear of the tractor is provided with a tillage depth sensor 4 for detecting the tillage depth of the rotary tillage device R when controlling the working depth of the work implement. Further, a lift angle sensor 3 is arranged at the base of the lift arm 13 for position control.

Referring to FIGS. 4 and 5, the electronic governor mechanism G
V will be described. The electronic governor mechanism GV is attached to the side of the engine E, and the camshaft 16 of the fuel pump is provided.
The magnetic rotator 12 is fixed to the rotator. The rotation of the camshaft 16 is detected by the rotation speed detection sensor 1 of the magnetic rotating body 12 to obtain the rotation speed of the engine E. Also, the fuel rack 10
The fuel supply amount of the electronic governor mechanism GV is adjusted by the left and right movement of the electronic governor mechanism GV. The rack actuator 9 drives the fuel rack 10 by the control command signal. Also, the fuel rack 1 is controlled by the rack actuator 9.
The rack position sensor 2 detects the position of “0” and detects the fuel supply amount. A rack bar 11 connected to a fuel rack 10 is inserted through the rack position sensor 2 and the rack actuator 9.

Referring now to FIG. 6, an electronic governor mechanism GV
The control curve of the engine E will be described. In the engine E, the engine output and the shaft torque are determined by the injection amount and the injection timing of the fuel injection pump and the engine speed.
The fuel injection amount is adjusted by sliding the fuel rack 10 by the rack actuator 9. And it is obtained by measuring the injection amount based on the position of the fuel rack 10 and the engine speed. The injection timing is adjusted by a timing adjustment actuator (not shown). The engine speed is detected by a speed detection sensor 1.

When the operator turns the accelerator lever 14 to the electronic control unit, the accelerator lever sensor 5
The instruction of the number of revolutions is made via the. The electronic control unit uses a microcomputer, and a program ROM storing a control program is arranged. In addition, a data ROM storing various data required for control calculation such as speed fluctuation rate characteristics is arranged.

In the data rom, what is the set value of the engine speed arbitrarily set according to the position of the accelerator lever 14 operated by the operator himself and the actual speed (actual value) according to the load. The speed variation characteristic is stored in the form of an arithmetic expression or a numerical table for each different work content. Regarding the speed fluctuation rate, the set value and the actual value of the engine speed are recognized, then the mode set by the operator is recognized, and the target rack position to be set is calculated by the droop rate map according to the mode. . A signal for changing the actual rack position to the corrected target rack position is output to the rack actuator 9, the fuel rack 10 is automatically adjusted, and the operation is performed within a predetermined speed fluctuation range.

Normally, in order to recognize a predetermined speed fluctuation, FIG.
Is performed along the map d of the droop control, the fuel rack 10 changes, and the shaft torque changes. However, the speed variation characteristic is selected according to the mode of the work content, and the constant rotation operation is required. In such a case, constant speed operation is performed along the map i of the isochronous control so as to increase or decrease the fuel consumption and keep the load factor constant. In addition, even in the case of isochronous control, especially in the case of special work, reverse droop to increase engine speed and increase shaft torque to prevent engine stall, in a state where the load increases and it is close to the maximum shaft torque It is also possible to select a control map r.

FIG. 7 shows a hydraulic circuit diagram of the working machine elevating mechanism. Lift arm 13 to hydraulic cylinder 2
A lift angle sensor 3 that rotates up and down by expansion and contraction of 0 and detects the position of the lift arm 13 is provided. The lift hydraulic control valves V1 and V2 control the pressure oil to the hydraulic cylinder 20, and the lift electromagnetic valve V1 and the downward magnetic valve V2
Is transmitted from the lift electronic control unit C.

FIG. 8 is a drawing showing the basic structure of control combining the electronic governor mechanism GV and the plowing depth control system, FIG.
9 is a flowchart of the control in FIG. In this control, an electronic governor mechanism GV that controls the engine E
And the control means for controlling the tillage depth of the rotary tillage device R, thereby controlling the tillage depth of the rotary tillage device R at a load ratio at each rotational speed of the engine E from the electronic governor mechanism GV. As the load factor detection value A in the electronic governor mechanism GV, the fuel injection amount corresponding to the rotation speed at that time is read and used as the load factor detection value A. Conventionally, in the case of such a control, at the time of the rated rotation speed of the engine E, it is detected whether the rotation of the engine E has decreased or increased, and control of the plowing depth is performed by a change in the rotation speed. It was. Therefore, in the above-described conventional control configuration, the control cannot be used unless the accelerator lever 14 is always in the full rotation state.

On the other hand, in the case of the control of the present invention,
The output of the load rate of the electronic governor mechanism GV intercepts a signal from the harness transmitted to the load display, and replaces the signal from the tillage depth position sensor 4 which has conventionally detected the tillage depth signal with this electronic signal. The signal of the load factor of the governor mechanism GV is input. If the cultivation depth is controlled by this method, the control based on the load factor can be performed even when the tractor is lightly operated. In FIG. 9, the control flowchart of FIG. 6 is separately illustrated for the electronic governor control portion and the tillage depth control portion. In the electronic governor mechanism GV, the engine output state at the operation speed of the load factor is displayed on the load factor display 18 as a bar graph. The load factor display 18
Is 10 graduations, and when illuminated at the front, indicates that it is the maximum output at that rotation speed,
The lighting degree indicates how much the load of the work implement is relative to the maximum output, and the margin of the engine load can be determined.

The flowchart of FIG. 9 will be described. The operator reads the load factor detection value A indicated on the load factor indicator 18 and, as shown in FIG. By comparing the value A with the load factor set value B,
The electronic control unit controls the lift elevating solenoid valves V1 and V2,
The rotary tiller R is moved up and down.

FIG. 10 is a basic block diagram of control for intermittently controlling the plowing depth based on the load factor detection value A and the load factor set value B. FIG. 11 is a drawing showing the pulse width of the intermittent control.
2 is a flowchart of the control in FIG. The control shown in FIGS. 10, 11, and 12 corresponds to the load factor detection value A shown in FIGS.
And the control by the load factor set value B is performed intermittently. That is, as described above, since the load factor detection value A is used by replacing the fuel injection amount with respect to the rotation speed at that time, it is assumed that the rotary tilling apparatus R slightly moves up and down for control based on the calculation result. Also, the change in the load factor is slow to appear due to the calculation result of the electronic governor, and a hunting state in which control does not easily converge occurs. In order to solve this problem, intermittent control is performed.

As shown in FIG. 10, the intermittent control is turned on.
In the case of, the load factor detection value A is input as a control signal,
When the intermittent control is OFF, the signal of the load factor set value B used for normal plowing depth control is input as it is.
Thus, when the intermittent control is OFF, the load factor set value B
This signal is input in order to avoid an abnormal mode when the signal of the load factor detection value A is not input, although the signal from the load factor set value B is output. If the signal from the tillage depth position sensor 4 is given in this way, since both of them have the same load factor set value B, the rotary tillage device R does not go up and down.

When the rotary tilling device R is in the highest state, the intermittent control is turned off, and the load factor set value B is directly input instead of the load factor detection value A, whereby the rotary tilling device is rotated. The device R does not move up and down. Further, in the above intermittent control configuration, as shown in FIG. 11, when the load factor set value B is small, the ON time is controlled to be short and the OFF time is lengthened, and conversely, when the load factor set value B is large. Is controlled so that the ON time is long and the OFF time is short.

FIG. 13 is a control block diagram of control in which the control amount is proportional to the magnitude of the load factor detection value A, and FIG.
3 is a flowchart of control of FIG. Although FIG. 11 is configured to change the length of ON-OFF according to the magnitude of the load factor set value B, in the embodiment shown in FIGS. , Control amount ON-O
It is configured to change in proportion to the size of the FF time. When the load factor detection value A is small, it reacts too sensitively to the change in the plowing depth. Therefore, there is a possibility of hunting if the control amount is increased once, and when the load factor detection value A is large, This is because, since it reacts insensitively to a change in tillage depth, a small control amount at one time may cause engine stall. A flowchart of the control of the time is disclosed in FIG. The control amount SR is calculated by multiplying the constant by the load factor detection value A, and the control ON time is calculated by multiplying the time t by the control amount SR.

FIG. 15 shows load factor control and tillage position sensor 4.
Block diagram of control that allows you to select tillage depth control by
FIG. 16 is a flowchart of the control in FIG.
In the case of roughing work for rice cultivation, efficiency is more important than accuracy of cultivation depth, load factor control is effective, and we hate pressing the soil with the rear cover of the rotary tilling device R, In the case of plowing upland cultivation soil, the unevenness of the surface is a problem, so that the normal plowing depth control by the plowing depth position sensor 4 is desired. In such a case, a switch is provided to enable switching between load factor control and normal plowing depth control.

FIG. 17 is a control block diagram of a mechanism for performing mixed control of load factor control and plowing depth control, and FIG. 18 is a flowchart of the control of FIG. In this case, the rotary tilling device R is configured to be moved up and down in a state where the load factor control and the plowing depth control are mixed, and the mixing degree according to the state of the working machine can be set. As shown in FIG. 18, the mixing ratio S is read, and the tillage depth position sensor 4 and the load ratio detection value A are read.
Is divided into this mixture ratio and controlled as detection.

FIG. 19 is a control block diagram for performing position control without performing load factor control when the detected load factor A does not exceed a preset value, and FIG.
9 is a flowchart in the case of the control of FIG. The purpose of this control is that if only the load factor control is performed, it becomes impossible to stop the rotary tilling device R halfway while raising or lowering the rotary tilling device R in a non-working state.
When the load factor detection value A is equal to or greater than a certain load factor, the load factor control is performed when it is determined that work is being performed.

FIG. 21 is a control block diagram in which the position control is performed when the rotary tilling device R is at the high position, and the load factor control is performed when the rotary tilling device R is in the low position. FIG. 22 is a flowchart of the control in FIG. In this control, the position of the rotary tilling device R is detected and automatically controlled. With this configuration, it is possible to prevent engine stall when the rear wheel of the tractor suddenly falls into a groove or the like accidentally while working at a relatively shallow plowing depth. FIG. 22 discloses a flowchart of the above control.

FIG. 23 is a block diagram of control for performing load factor control when the cultivation depth is deep, and performing normal cultivation depth control when the cultivation depth is shallow. FIG. 24 is a flowchart of the control of FIG. As described above, the control switching based on the depth of tillage is
The configuration may be such that it is automatically determined and controlled, or the determination may be made according to the set value. The purpose of this control is to control the depth of the cultivation rather than maintaining the cultivation depth, since the depth of the cultivation is important when the cultivation depth is shallow, and when the cultivation depth is deep, the work is performed at the maximum engine power. This is because it is more important to control so as not to do so. The control is performed according to the flowchart of FIG.

FIG. 25 is a control block diagram of a control for temporarily interrupting or stopping the load factor control when the set value of the engine speed is changed in the load factor control.
Is a control flowchart of FIG. When the rotation speed is increased by the accelerator lever 14, the fuel is increased at the rack position of the fuel injection device. Therefore, in the load ratio control in which the fuel is read as the load factor, the rotary tilling device R is raised. When the number of revolutions is reduced, the rack position reduces the fuel, so that it is determined that the load has decreased and the rotary tilling device R is lowered.
Since such a trouble occurs, the accelerator lever 14
When the engine speed is changed by rotating the, the load factor control is stopped until the rack position returns to the control position.

[0029]

As described above, the present invention has the following advantages. That is, as in claim 1,
It has an electronic governor mechanism that controls the engine, and a plowing depth control unit that controls the work machine.
Since the tillage depth is controlled based on the load factor, the tillage depth can be controlled by the load factor detection value A even when the operation by the tractor is light. In addition, the load factor control is performed by setting the load factor set value B set in the load factor
When the signal is ON, the electronic governor mechanism G
Load factor detection value A detected from V is input as a control signal
However, in the case of OFF, the load set in the load factor setting unit 17 is negative.
Input the signal of the load factor set value B as is, ON-OFF
Since the intermittent control is performed , hunting caused by a delay in the signal of the load factor detection value A can be avoided.

According to a second aspect of the present invention, there is provided a mechanism having an electronic governor mechanism for controlling an engine and a tillage depth controlling means for controlling a working machine, wherein the working depth is controlled based on a load factor in a working state of the working machine. The negative value set in the load factor setting unit 17
By setting the control amount of the plowing depth control smaller as the load factor set value B is smaller, hunting that occurs when the load factor is smaller is avoided, and engine stall that occurs when the load factor set value B is larger is avoided. It became possible.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor equipped with a rotary plow as a working machine.

FIG. 2 is a schematic diagram of a control mechanism of a plowing depth control mechanism of the tractor working machine according to the present invention.

FIG. 3 is a diagram showing an instrument arrangement of a dashboard section of the tractor.

FIG. 4 is a side sectional view of the electronic governor mechanism GV.

FIG. 5 is a side sectional view of the electronic governor mechanism GV.

FIG. 6 is a drawing showing an example of a control map by the electronic governor mechanism GV.

FIG. 7 is a hydraulic circuit diagram of a working machine lifting mechanism B including lift lifting / lowering solenoid valves V1 and V2.

FIG. 8 is a diagram showing a basic configuration of control in which an electronic governor mechanism GV and a tillage depth control system are combined.

FIG. 9 is a flowchart of the control of FIG. 8;

FIG. 10 is a basic block diagram of control for intermittently performing plowing depth control based on the load factor detection value A and the load factor set value B.

FIG. 11 is a diagram showing a pulse width of intermittent control.

FIG. 12 is a flowchart of the control in FIG. 10;

FIG. 13 is a control block diagram of control in which the control amount is proportional to the magnitude of the load factor detection value A.

FIG. 14 is a flowchart of the control in FIG. 13;

FIG. 15 is a block diagram of control in which the load factor control and the plowing depth control by the plowing depth position sensor 4 can be freely selected.

FIG. 16 is a flowchart of the control in FIG. 15;

FIG. 17 is a control block diagram of a mechanism that performs mixed control of load factor control and plowing depth control.

FIG. 18 is a flowchart of the control in FIG. 17;

FIG. 19 is a control block diagram when position control is performed without performing load factor control when the load factor detection value A does not exceed a preset value.

FIG. 20 is a flowchart for the control in FIG. 19;

FIG. 21 is a control block diagram in which position control is performed when the rotary tilling device R is at a high position, and load factor control is performed when the rotary tilling device R is at a low position.

FIG. 22 is a flowchart of the control in FIG. 21;

FIG. 23 is a block diagram of control for performing load factor control when the tillage depth is deep and performing normal tillage depth control when the tillage depth is shallow.

FIG. 24 is a flowchart of the control in FIG. 23;

In Figure 25 the load factor control, when there is a change in the engine speed set value, control gob lock diagram of a control for one interrupt or stop the load factor control.

26 is a control flowchart of FIG. 25.

[Explanation of symbols]

 A Load ratio detection value B Load setting value GV Electronic governor mechanism 1 Rotation speed detection sensor 2 Rack position sensor 3 Lift angle sensor 4 Plowing depth position sensor 5 Accelerator lever sensor 17 Load setting device 18 Load ratio display

Claims (2)

(57) [Claims] 1. A tractor having an electronic governor mechanism for controlling an engine and a cultivation depth control means for controlling a working machine, comprising a load factor setting device 17 for an operator to set a load factor. And a load factor detection value A detected by the electronic governor mechanism GV .
In response to the signal of the load factor set value B set to
In this case, the load factor detected by the electronic governor mechanism GV
Detected value A is input as a control signal, and when it is OFF,
The signal of the load factor set value B set in the load factor setter 17 is
Perform intermittent control by inputting as is, and lift from the electronic control unit.
By controlling the lifting / lowering solenoid valves V1 and V2, the rotary tilling device R
A cultivation depth control mechanism for a tractor working machine, wherein the cultivation depth is controlled by raising and lowering . 2. Tillage control of a tractor working machine according to claim 1.
In the control mechanism, the smaller the load factor set value B, the higher the ON
Time is short, the OFF time is controlled to be long,
The larger the constant value B, the longer the ON time and the OFF time
A cultivation depth control mechanism for a tractor working machine, characterized in that control is performed to shorten the interval .