JPH0527363B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a cutting height control device for a combine harvester, and particularly to a cutting height control device using a non-contact type sensor using wave motion such as ultrasonic waves. More specifically, the present invention relates to a cutting height control device that can freely set the cutting height using a cutting height target setting device.

(b) Conventional technology Conventionally, the height of the cutting section above the ground is detected by measuring the reflection delay time from the field using ultrasonic waves, and the cutting is performed so that the height above the ground becomes the target setting value. A cutting height control device has been devised to control the elevation of the cutting height. The mowing height control device can freely set the target mowing height using the setting device;
Even if the target value is set at the mowing position using the setting device, or when the target value is set at the low mowing position,
The reaping section is configured to move up and down at the same constant speed.

(c) Problems to be solved by the invention For this reason, when the reaping section is set at a low mowing position and the mowing is performed at a low traveling speed, such as when reaping fallen timber, the reaping section has to reduce the vertical movement and cut the rice field. Although it is desirable to be controlled so as to slide, the reaping section is controlled to move up and down at a high speed, and it often jumps over fallen materials, resulting in uncut material. In addition, if the vertical movement speed of the reaping section is set to be slow for low mowing, when reaping at a certain high cutting speed, such as vertical culm reaping, the vertical movement of the reaping section will be too small, resulting in a control delay. There is a possibility that this may occur.

(d) Means for solving the problem The present invention aims to solve the above-mentioned problem, and the present invention is aimed at solving the above-mentioned problems, and it is a method of changing the speed of a solenoid valve or the like that drives the reaping section by a pulse signal whose pulse width is changed. and a dead zone width changing means, and these speed changing means and dead zone width changing means are linked to a mowing height target setter, and when the target value of the setter is at the low mowing position, the speed is controlled. The speed changing means is set to become slower and the dead zone width becomes narrower, and when the target value is at a high cutting position, the speed changing means is set to become faster and the dead zone width becomes wider. be.

(E) Effect Based on the above configuration, when in the low cutting state, the reaping section is controlled to rise and fall at a slow speed, and is controlled to lick the field area in accordance with the low speed movement of the combine, and the dead zone width is also controlled to be at the low speed. In addition, when the mowing section is in a high-mowing state, the reaping section is controlled to move up and down at a high speed, and the dead zone width is also widened, so that the control is performed without delay in accordance with the high-speed running of the combine harvester.

(f) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the combine 1 has a body 3 suspended by a crawler 2.
The aircraft body 3 is provided with a driver's seat 5 and the like. Furthermore,
At the front of the machine body 3, a reaping section 6 is supported by a hydraulic cylinder 7 (FIG. 1) so as to be movable up and down, and a large number of weeding bodies 9 are installed in the reaping section 6 so as to protrude forward. Direction sensors 10 and 11 each having a sensor arm protruding inward of the machine are disposed on the right side, that is, the already-mowed side grass divider 9a, and the left side, that is, the already-mown side grass divider 9b. , 11 are automatically switched based on the difference in the operation of the intermediate changeover switch and the sensors during row mowing and horizontal mowing, so that the direction sensor 11 on the non-mow side operates during row mowing, and when horizontal mowing The direction sensor 10 on the mowed side is activated, and the direction sensor 11 on the unmown side is configured to be activated during splitting. Also, the right side or left side (first
(shown illustratively on the right side in the figure)
A non-contact cutting height sensor 12 consisting of an ultrasonic sensor is installed behind the sensors a and 9b, and the sensor 12 includes a transmitter 12a that emits ultrasonic waves toward the field and It has a receiver 12b for receiving reflected waves (see FIG. 3).

Further, a dial-type mowing height target setting device 13 is installed in the driver's seat 5, as shown in FIG. The setting device 13 has an OFF region at the end of the low mowing position, and the low region x from the low mowing position C to the predetermined high mowing position A is defined as the OFF region from the low mowing position C direction to the predetermined high mowing position, as shown in FIG. This is a pulse width changing region where the on-pulse width increases proportionally in the A direction (T _C < T _B < T _A ), and in the pulse width changing region x, the dead band width also increases proportionally. (N _C < N _B < N _A ). In addition, the predetermined height mowing position A
In the upper high region y, the on-pulse width is held constant to be the maximum pulse width T _A in the changing region, and the dead band width is also the maximum dead band width N _A in the changing region.
is held constant so that Note that H in FIG. 1 is the uppermost position of the reaping section.

As shown in FIG. 3, a cutting height target setter 13 consisting of a click variable resistor is connected to an A/D1 port of a microcomputer (CPU) 15.
Further, a cutting height rotation pilot lamp 16 and cutting height manual operation switches 17u and 17d are provided, respectively.
Connected to CPU15. Further, the transmitter 12a of the cutting height sensor 12 is connected to the OUT2 port of the CPU 15 via the ultrasonic transmitter 19 and the drive circuit 20, and the receiver 12b is connected to the amplification detection circuit 2.
1 and is connected to the IN3 port of the CPU 15 via a level conversion circuit 22 that shapes the pulses and converts them into digital pulses. Further, an automatic direction pulse width setter 23, an automatic direction pilot lamp 25, a mid-cut changeover switch 26, and an already-cut side direction sensor 1 are provided.
0 and the uncut side direction sensor 11 are connected to each port of the CPU 15. In addition, the CPU 15 is connected to each solenoid of the cutting height control valve 27, which is a pulse width changing solenoid valve.
The output is from the OUT3 and OUT4 ports of the CPU 15, and each solenoid of the directional solenoid valve 29 and the check valve 30 is also
output from the port. Pressure oil from the pump 31 is introduced to the cutting height control valve 27, and the check valve 3 is further fed from the control valve 27.
0 to the hydraulic cylinder 7 for raising and lowering the reaping section, and to left and right side clutches 32L and 32R via a directional solenoid valve 29.

Next, the operation of this embodiment will be explained along the flow shown in FIG.

First, the operator selects manual or automatic cutting height control (F1), and in the case of manual operation, turns off the setting device 13 and switches the manual operation switches 17u, 17.
d, a continuous signal is issued to the reaping section 6 to control its elevation (F2), and in the case of automatic control, the mowing height target setter 13 is set to an arbitrary value (F3). At this time, the CPU
The ON signal enters the A/D1 port of 15 and the pilot lamp 16 lights up (F4), but if it is OFF,
The lamp 16 does not light up and automatic control is stopped (F5, F6). Then, the target set value of the setter 13 is determined in the pulse width change region x (F7), and the target setting value of the setter 13 is
, the on-pulse widths T _C to T _B are set according to the position of the setter 13 (F8), and the dead band widths N _C to N _A are set (F9). Further, in the high cutting height region y outside the pulse width changing region x, the predetermined pulse width T _A and dead band width N _A are set (F10). Ultrasonic waves are emitted from the transmitter 12a of the cutting height sensor 12 for a certain period of time, and the ultrasonic waves are reflected on the field and received by the receiver 12b. 6's ground position, that is, the actual cutting height is detected, and the input signal is sent to CPU1.
5 (F11), and after a certain period of time, the transmission of ultrasonic waves is stopped (F12). Then, the actual detection data by the sampling-controlled cutting height sensor 12 is averaged (F13), and the actual detection average value and the target value by the setting device 13 are made variable at the target setting value. The comparison is made taking into account the dead zone width α. That is, when the target value is larger than the sum of the detected average value and the dead band width α (F14), a pulse signal consisting of an on-pulse width corresponding to the target setting value is output from the OUT3 port of the CPU 15 and the cutting height control valve 27 is outputted from the OUT3 port of the CPU 15. is controlled intermittently, pressure oil is sent to the hydraulic cylinder 7, and the cutting section 6 is raised at a speed corresponding to the cutting height (F15). If the target value is smaller than the detection average value minus the dead band width α (F16), a pulse signal with a predetermined pulse width is output from the OUT4 port of the CPU 15, and the cutting height control valve 27 is controlled intermittently. Check valve 3
0 is also driven, the oil in the hydraulic cylinder 7 is discharged, the reaping unit 6 is lowered at a speed corresponding to the cutting height (F17), and the target value is within the range of the detection average value plus or minus the dead zone width α. If it is within, the cutting height control valve 27 remains stopped and the reaping section 6 also stops (F18).

That is, when there is a lot of fallen material and the setting device 13 is set to the low mowing position C, the on-pulse width T _C is small;
In addition, the dead band width N _C is set small. Therefore,
The lifting speed of the reaping section 6 is slow, and the reaping section 6 is controlled to lick the field in response to the slow running speed of the combine harvester 1.The reaping section 6 is controlled with high sensitivity due to the fine response due to the small dead zone width _N. Accurate elevation control is performed even in the slightest change, and accurate cutting height control is performed without overcutting fallen materials and leaving uncut material. In addition, if the field is in a standing culm state, the setting device 13
When set to high mowing position A, on-pulse width
T _A is set large, and dead band width N _A is set large. Therefore, the lifting speed of the reaping section 6 is fast, and the cutting height control is not delayed in response to the fast traveling speed of the combine harvester 1, and the reaping section 6 is quickly controlled up and down.
In addition, based on the large dead band width N _A , the elevation control is properly performed so that hunting does not occur even with rapid elevation control, and the aircraft does not shake and cause discomfort to the operator.

In addition, in the above-mentioned embodiment, the pulse width is changed on both the upward and downward sides of the cutting height control valve 27, but especially when cutting at a low level, the cutting section 6 rises significantly and jumps over the fallen material. Since the purpose is to prevent this, the pulse width on the rising side, i.e.
The purpose can be sufficiently achieved by simply changing the output from the OUT3 port of the CPU 15 according to the set value.

Furthermore, for the same reason, a certain degree of accuracy is required on the ascending side, but not so much on the descending side, so there is no need to use an expensive inching valve on the descending side, and instead of the check valve 30, an inching valve can be used. If a fixed throttle valve 30' shown in FIG. 3 is provided and the throttle is used for control, there is no need to use an expensive inching valve for both raising and lowering, and the cost becomes low. Note that when using the throttle valve 30',
Instead of directly inputting the output of the OUT4 port, the aperture is switched only when the cutting area is in the low cutting area x, and the descending speed is changed between low cutting and high cutting. Also,
If the diaphragm for low mowing is a variable diaphragm, the descending speed can be changed proportionally according to the set cutting height, and the same effect as pulse width control can be achieved.

Further, in the above-described embodiment, the vertical speed of the reaping section 6 is controlled by changing the on-pulse width, but the off-pulse width, that is, the frequency, may also be changed, and furthermore, both the on-pulse width and the off-pulse width may be changed for control. Of course, this is a good thing.

(G) Effects of the Invention As explained above, according to the present invention, the rising (lowering) speed of the reaping section 6 is changed in conjunction with the cutting height target setting device 13, so that it is possible to reduce When mowing at low speed, the reaping section 6 is controlled to slowly rise (lower) and lick the field.
It is possible to reliably prevent the occurrence of uncut material by jumping over fallen materials, and when moving at high speed with a high mowing such as when reaping vertical culms, the reaping section 6 quickly rises (descends), causing a control delay. Therefore, the cutting height can be controlled appropriately. In addition, since the adjustment of the vertical speed of the reaping section 6 is automatically performed by the target setting device 13, there is no possibility of poor control due to poor or forgotten adjustment, and the mowing height can always be controlled reliably and accurately. It can be carried out. Furthermore,
At the same time as adjusting the vertical speed of the reaping section 6, the width of the dead zone can be adjusted.
Since it is configured to change N _C ~ N _A , by setting the dead zone width small when mowing at low levels,
Corresponding to the slow lifting and lowering speed of the reaping unit 6, even minute changes in the field can be controlled with high sensitivity, and by setting a large dead zone width during high cutting, even if the reaping unit 6 is quickly controlled up and down. , the reaping section can always be appropriately controlled to raise and lower without causing hunting.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the relationship between the cutting height target setter and the elevation control of the reaping section, Fig. 2 is a perspective view showing a combine harvester to which the present invention can be applied, and Fig. 3 is a diagram showing the connections of each operating device. 4 are diagrams showing the flow of the present invention. DESCRIPTION OF SYMBOLS 1... Combine harvester, 6... Reaping part, 12... Cutting height sensor, 13... Target setter, 15...
CPU, 27... Speed changing means (solenoid valve), 30, 30'... Dead band width changing means (check valve, throttle valve), x... Pulse width changing area,
y... Constant pulse width region.

Claims (1)

[Claims] 1. A mowing height sensor and a target setting device are provided, and a target value by the setting device is compared with a detection value by the cutting height sensor to automatically control the elevation of the reaping section to match the target value. In the cutting height control device for a combine, a speed changing means for changing at least the rising speed of the lifting speed of the reaping section and a dead band width changing means for changing the dead zone width are provided, and the speed changing means and the dead zone width changing means are combined with each other. The mowing height target setter is linked with the mowing height target setter, and when the target value of the setter is at the low mowing position, the speed changing means is set to become slower and the dead zone width is narrower, and the target value is A mowing height control device for a combine harvester, characterized in that when the combine harvester is at a high mowing position, the speed changing means is set to become faster and the dead zone width becomes wider. 2. The cutting height control device for a combine harvester according to claim 1, wherein the speed changing means comprises changing means for changing both the ascending speed and descending speed of the cutting section. 3. The cutting height control device for a combine harvester according to claim 1 or 2, wherein the speed changing means is a solenoid valve driven by a pulse signal whose pulse width is changed. 4. The speed changing means according to claim 2, wherein the speed changing means is a solenoid valve driven by a pulse signal whose pulse width is changed on the ascending side, and a throttle valve interposed in the hydraulic circuit on the descending side. Combine cutting height control device.