JPS583642B2 - Automatic cutting height control device for combine harvesters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a device for controlling the height of a reaping section in a combine harvester that automatically reaps grain rods of rice, wheat, etc.

In recent years, small combine harvesters suitable for small-scale agriculture in Japan have been developed and are being put into practical use one after another.Generally, they have a structure shown in the side view in Figure 1, and a weed cover 2 is installed in front of the combine 10 body. and clippers. A shaped reaping section 3 is integrally provided, and a height sensor 4 is provided below the reaping section 3 to detect the distance from the ground and determine the height of the reaping section 3.
Hydraulic mechanism 5
The height of the entire tip including the grass cover 2 and the cutting section 3 is controlled.

The height of the tip is controlled in a pulse-like manner, that is, in a step-like manner, by the control device described later, in order to avoid hunting phenomena during control, damage to various parts due to rapid movement, and instability of the control action. There is.

However, the above-mentioned stepwise control has disadvantages in the following cases.

That is, as shown in Fig. 2, at corner 12 of field 11, it becomes necessary to turn from the direction shown by arrow 13 to direction 14, and in this case, first make a curve in direction 15, and then
Move backward in the direction of 16, then move forward in the direction of 14.

Therefore, in this case, the area around the field is likely to be disturbed by the crawler 6 shown in FIG.
There was also a risk that the reaping part 3 would be pushed into the ground, causing damage to these parts.

In addition, Fig. 3 A is just before starting to move forward from 16 to 14 in Fig. 2, B is on the protrusion 21 on the ground, and C is climbing over the protrusion 21 and thrusting the grass cover 2 into the ground. At A, the height sensor 4 detects a large distance from the ground, and controls the height of the tip to be small, and at B, the height sensor 4 detects a large distance from the ground, and at B, the height sensor 4 detects a large distance from the ground and controls the height of the tip to be small. Start mowing at a height, but the tip is lower than the preferred height on horizontal ground.

At C, even if the height sensor 4 detects a small ground clearance,
Coupled with the excessive lowering of the tip at point B, the control to increase the height of the tip was not done in time, and the weed cover 2 plunged into the ground.

As mentioned above, although the conventional supp-like control has the advantage of being able to perform stable control, it lacks quick response and has the major drawback of being particularly inconvenient when dealing with uneven ground.

The present invention has an object of solving the above-mentioned conventional deficiencies at once, and in the automatic cutting height control device for the above-mentioned combine harvester, the height sensor of the receptacle that determines the height of the reaping part has an abnormally small ground clearance. The invention is characterized in that a control circuit is provided that continuously controls the height of the tip section including the reaping section in the direction of height when the height of the tip section is detected, so that the tip section can be raised quickly even if the ground is uneven. The present invention provides an extremely effective automatic cutting height control device for a combine harvester, which prevents damage to the grass cover etc. due to the cutting of the grass by pushing it into the ground.

The details of the present invention will be explained below with reference to FIG. 4 and subsequent figures showing embodiments.

FIG. 4 shows a side view of the height sensor 4, in which an actuator 33 is always urged toward the ground 34 and protrudes rotatably from the side of the switch box 32 from which the cord 31 is led out, and the distance between the actuator 33 and the ground is When G is normal, it is within the range of rotation angle θn, and when G is large, the rotation angle θd,
When the ground clearance G is small, the rotation angle is θu, and if the ground clearance G exceeds the rotation angle θu and becomes abnormally small, the rotation angle is within the range θe, and the rotation angle in the switch box 32 corresponds to each of these rotation angles. The switch described below is activated,
Sends a signal to raise or lower the tip.

However, within the range of rotation angle θn, none of the switches operates and no signal is sent.

A predetermined cam mechanism is still interposed between the switch and the actuator 33, and the switch operates as described below.

FIG. 5 shows a block diagram of an automatic mowing height control device including a height sensor 4, a control unit CTU using an electronic circuit, and solenoids SOL-U and SOL-D for driving the valves of the hydraulic mechanism 5. Based on the signals given by the on/off switches Ku and Kd in the control unit CTU, the solenoid SOL-U
Or, by passing current to SOL-D, solenoid SOL-U
When the solenoid SQL-D is energized, the tip rises, and when the solenoid SQL-D is energized, the tip falls, and in both cases a predetermined current is passed from the power source B.

Further, the switch SW is used to manually control the height of the tip, and the switch ACH is an automatic control switch that determines whether or not to operate based on a signal from the height sensor 4.

FIG. 6 is a circuit diagram showing the electronic circuit in the control unit CTU, and the area surrounded by broken lines is the continuous control circuit according to the present invention, but the conventional intermittent control will be explained first.

First, after turning on the switch ACH, when the switch SW is turned from N to D, the input of the inverter V1 becomes a low level (hereinafter referred to as "L"), its output becomes a high level (hereinafter referred to as "H"), and the transistor Q1 , Q2 turns on and grounds the falling output HSD.

Therefore, the solenoid SOL-D shown in FIG. 5 is energized, and the tip of the solenoid SOL-D is rapidly lowered.

Note that when the reaping section 3 is in the non-working position, the actuator 33 of the height sensor 4 is within the rotation angle θd, and the switch Kd is on.

Also, the output of inverter IV1 simultaneously sets flip-flop circuit FF1, and even if the switch SW is returned to N, transistors Q1 and Q2 remain unchanged as flip-flop circuit FF1.
In order to maintain the on state by the output of , the lowering operation of the tip continues.

When the actuator 33 of the height sensor 4 comes into contact with the ground 34 due to the lowering of the tip and rotates to the range of rotation angle θn, the switch Kd is turned off, and the inverter 2
The input becomes “H” and its output changes to “L”, and the NOR
Since both inputs of gate R1 are “L”, its output is “H”
becomes.

As a result, flip-flop circuit FF2 is set,
The output turns on transistors Q3 and Q4, producing an output DH, which turns on the lamp PL in FIG. 5 to indicate that the automatic cutting height control circuit is in operation.

Furthermore, the flip-flop circuit FF1 is reset by the output of the flip-flop circuit FF2, and the transistor Q
1 and Q2 are turned off and the lowering output HSD is turned off, so the lowering of the tip also stops.

On the other hand, from the other output of flip-flop circuit FF2, “
L” is applied to NOR gates R2 and R3, and switches Ku,
A circuit from Kd to transistors Q1 and Q5 is prepared to enable automatic cutting height control.

If the height sensor 4 enters a depression, the switch Kd is turned on and "L" is given to the NAND gate A1 and the NOR gate R2, and the output of the NAND gate A1 becomes "H".
This output, the "H" output of the NAND gate A3, and the fixed "H" level via the resistor r result in a NAND
The output of gate A2 becomes "L".

As a result, the reset state of the reset terminal R of the counter CUT is released, and the counter CUT is connected to the pulse generator CP.
The clock pulses from G are counted, and when, for example, 32 pulses are counted, the output terminal Q6 becomes "H".

Therefore, the output of inverter ■V3 becomes "L",
As a result, all inputs of NOR gate R2 become "L", so its output becomes "H" and transistor Q1,
Turn on Q2 and lower the tip.

Then, when the counter CUT counts two more pulses, the output terminal Q2 becomes "H", and both inputs of the NAND gate A30 become "H", so its output becomes "L".
becomes.

As a result, the output of NAND gate N2 becomes "H", counter CUT is reset, and both output terminals Q2 and Q6 become "L", but as a result, the N4ND gate voltage becomes "H", and the output of NAND gate A2 becomes "L"
Therefore, the reset is released again and the counter CUT starts counting clock pulses.

Similarly, while the switch Kd is on, the transistors Q1 and Q2 are on for only 2 pulses every 32 clock pulses, and automatic step-like lowering is performed intermittently, causing the tip to become small. When the actuator 33 contacts the ground 34 and rotates to the range of the rear rotation angle θn, the switch Kd is turned off, so that each circuit returns to its initial state and stops.

On the other hand, when the height sensor 4 enters a convex area, the actuator 33
is pushed by the ground 34 and rotates to a range of rotation angle θu, and the switch Ku is turned on.

Then, "L" is applied to NAND gate A1 and NOR gate R3, and the NAND gate becomes "H". As a result, the output of NAND gate N2 becomes "L" because other inputs are also "H", and counter C
Release the reset of the UT and start counting clock pulses.

Counter CUT sets the output terminal Q6 to "H" after counting 32 pulses in the same way as described above, and sets the output of inverter V3 to "L". As a result, all the inputs of NOR gate R3 become "L", so the output becomes "H", turning on transistors Q5 and Q6.

Therefore, the rising output HSU is grounded and energized to the solenoid SOL-U shown in FIG. 5 to raise the tip.

Note that while the switch Ku is on, the transistors Q5 and Q6 are turned on for only 2 pulses every 32 pulses of the clock pulse, and automatic step-like raising is performed intermittently, and the ground distance G is increased. When the actuator 33 rotates within the range of the rotation angle θn due to the increase in the rotation angle θn, the switch Ku is turned off, so that each circuit is restored and the upward movement is also stopped.

Next, when moving the combine harvester 1 after the reaping work,
To raise the tip to the non-working position, press switch SW.
Move from N to U.

Then, the input of inverter IV4 becomes "L" and its output becomes "H", so transistors Q5 and Q6 are turned on and the tip rises continuously and rapidly.

At the same time, one input of NAND gate A4 is also set to “L”.
” to set its output to “H”, thereby resetting the flip-flop circuit FF2, transistors Q3 and Q4 are turned off, the lamp PL connected to the output DH is turned off, and automatic mowing height control is canceled. inform.

As described above, the automatic mowing height control device operates, and stepwise raising and lowering are performed by detecting the distance from the ground by the height sensor 4.

In contrast, in the present invention, when the rotation angle θe in FIG. 4 is reached, both switches Ku and Kd in FIG. 6 are turned on simultaneously by the cam mechanism in the switch box 32, as shown by the broken line. Both inputs of NOR gate R4 in
”, the “H” output is applied to the transistors Q5 and Q6 to turn them on, and while both switches Ku and Kd are on, the solenoid SOL-U is forcibly energized, and the reaping section 3
The height of the tip including the tip is continuously controlled in the direction of increasing the height, that is, in the rising direction, to quickly raise the tip.

Therefore, if the height sensor 4 detects an abnormally small ground clearance G in the posture shown in FIG. 3C, the tip will immediately rise, resulting in the situation shown in FIG. You will never lose part 3.

As for the height sensor 4, in addition to turning on the switches Ku and Kd simultaneously by a cam mechanism, a third switch is provided, which is turned on when the actuator 33 reaches the rotation angle θe, and is directly connected to the transistor shown in FIG. It is also possible to apply a forward bias to Q5 and θ6, and the height sensor 4
Also, various configurations of the control circuit can be selected and used.

As is clear from the above explanation, according to the present invention, there is no fear that the grass cover and the cutting part will fall into the ground due to unevenness of the ground, and the mowing work can always be done in a safe condition, so the combine harvester can be operated unmanned. Great effects can be obtained.

[Brief explanation of the drawing]

Figure 1 is a side view showing an example of a combine harvester, Figure 2 is a diagram showing direction change movement at a field corner, Figure 3 is a diagram showing changes in the attitude of the combine due to unevenness of the ground, and Figures 4 onwards are diagrams showing the present invention. FIG. 4 is a side view of the height sensor, FIG. 5 is a block diagram of the automatic cutting height control device, and FIG.
It is a circuit diagram showing the electronic circuit of the control unit in the figure. 1... Combine harvester, 3... Reaping section,
4...Height sensor, 5...Hydraulic mechanism,
32...Switch box, 33...
Actuator, G...Ground distance, CTU...
...Control unit, SQL-U, SQL-D
...Solenoid, Ku, Kd...Switch, R4...NOR gate, Q5, Qe
...Transistor.

Claims (1)

[Claims] 1. In an automatic cutting height control device that intermittently controls the height of the reaping section in a combine harvester that automatically reaps grain rods, the height sensor of the reap that determines the height of the reaping section has an abnormally small ground clearance. An automatic cutting height control device for a combine harvester, characterized in that a control circuit is provided for continuously controlling the height of the tip section including the cutting section in a vertical direction when the cutting section is detected.