JPS6364167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting height control device for a cutting machine such as a combine harvester.

Conventionally, cutting height control devices detect the height of the cutting section from the ground, that is, the height of the cutting section from the field surface by grounding a sensor installed in the cutting section on the field, and based on the detection result, the height of the cutting section from the ground is detected. The mowing height was controlled by raising and lowering the mower. However, since the sensor cannot distinguish between a field scene and a stubble, it is easy for the sensor to ride on the stubble, especially during horizontal mowing work. , causing high mowing.

Therefore, the present invention is configured to detect the height of the stubble with a sensor, and to control the elevation of the reaping section by comparing the detection result with a set value, thereby achieving cutting height control that eliminates the above-mentioned drawbacks. The purpose is to provide a device.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the combine 1 has a traveling body 3 supported by crawlers 2.
A reaping section 5 is supported in front of the traveling body 3 so as to be movable up and down. The reaping section 5 is shown in FIGS. 1 to 3.
As shown in the figure, the cutting section has a frame 6, and the frame 6 has a divider 7 at the tip, a cutting blade 9 at the rear, and a cutting height sensor 10 fixed at the rear of the cutting blade 9. has been done. As shown in FIGS. 4 and 5, the sensor 10 has a sensor case 11. A shaft 12 is rotatably supported in the case 11, and a potentiometer 13 is connected to the case 11 by a threaded portion 13a. Fixed. Further, at the outer end of the case 11 of the shaft 12, there is a sensor arm 15 having a spatula-shaped tip.
is fixed, and an input shaft 13b of a potentiometer 13 is fixed to the inner end of the case 11 of the shaft 12. A predetermined portion of the shaft 12 is cut out to form a semicircular shape, and a rod 16 that is biased by a spring 14 is attached to the notched portion 12a.
contact, and the sensor arm 15 is
It is biased to the position shown in the figure. In addition, 17 in the figure
is a screw for adjusting the biasing force of the spring 15.

As shown in FIG. 6, the output of the potentiometer 13 is directly input to a differential amplifier 20 via a and a delay timer 19, and the output c of the amplifier 20 is input to comparators 21a and 21.
b and amplifier 22, and comparators 21a and 21b each have a minimum value setter 23a and a maximum value setter 23b which can be set arbitrarily.
Signals from the are also input. Furthermore, the outputs of the comparator 21a and the amplifier 22 are connected to an AND circuit 25.
a, and furthermore, the output e of the circuit 25a
is input to a solenoid valve 27a which raises the cutting section 5 via a transistor 26a.
On the other hand, the outputs of the comparator 21b and the amplifier 22 are input to an AND circuit 25b, and the output d of the circuit 25b is further input to a solenoid valve 27b that moves down the reaping section 5 via a transistor 26b.

In addition, in the figure, 30a is a standing grain culm, and 30b is a stubble. Further, as shown in FIG. 8, the spatula-shaped portion 15a of the sensor arm 15 is set to be slightly larger than the stubble interval L,
The sensor arm 15 is configured not to pass between adjacent stubbles 30b.

Since the present embodiment has the above-described configuration, the erect grain culm 30a is cut off by the cutting blade 9 as the combine harvester 1 travels, and the spatula-shaped sensor arm 15 is placed on top of the cut stubble 30b. Ganoru. Then, the sensor arm 15 is connected to the spring 1
4 in the direction of arrow A, and rotates the potentiometer 13 via the shaft 12, so that the meter 13
is output as shown in FIG. 7a. Further, the output signal a is branched and output as shown in FIG. 7b via the delay timer 19, and both output signals a and b
is input to the differential amplifier 20, and both output signals a, b
The difference is amplified and output as shown in FIG. 7c. Then, the output signal c is sent to the comparator 21
a, 21b. Now stubble 30b
is higher than the set value, so the above output signal c is c ₁
If the signal is larger as shown in FIG. 7, the comparator 21b outputs the signal compared with the signal from the maximum value setter 23b, and then the AND circuit 25b outputs the signal as shown in FIG. 7d based on the output signal and the output signal from the amplifier 22. do. The output signal d causes the transistor 26
The lowering solenoid valve 27b is energized via the lowering valve 27b, and the reaping section 5 is lowered. Since the output signal d is a pulse signal of a predetermined width based on the delay timer 19, the lowering of the reaping section 5 is stopped when the one pulse signal disappears. On the other hand, if the stubble 30b is lower than the set value and therefore the output signal c from the differential amplifier is small as shown in _c2 ,
The comparator 21a outputs the signal compared with the signal from the lowest value setter 23a, and the AND circuit 25a
outputs as shown in FIG. 7e. Then, the raising solenoid valve 27a is energized by the output signal e via the transistor 26a, and the reaping section 5 is raised by one pulse time. Further, when the stubble 30b is within the set value, the output signal c from the differential amplifier is as shown in _c3 .
between the signals from 23b and both comparators 2
Both 1a and 21b do not output. Therefore, both
The AND circuits 25a and 25b do not output any output, and the reaping section 5 maintains the same height.

As explained above, according to the present invention, the height of the stubble 30b is detected by the sensor 10, and the height of the cutting section 30b is increased by comparing the detection result with a set value.
Since the height of the stubble is controlled, unlike conventional methods, the stubble is not mistakenly detected as the field, it is possible to eliminate abnormally high mowing, and constant control is possible regardless of row mowing or horizontal mowing. Furthermore, the height of the stubble 30b becomes constant, and the stubble can be neatly arranged after cutting. Furthermore, since the height of the stubble immediately after cutting is detected and only one pulse is controlled based on the detection, hunting is prevented and stable control can be performed.

[Brief explanation of drawings]

Fig. 1 is a side view showing the reaping section of a combine harvester to which the present invention is applied, Fig. 2 is a plan view showing the cutting height sensor section, Fig. 3 is a side view thereof, and Fig. 4 is the cutting height. 5 is a front sectional view of the sensor, FIG. 5 is a side sectional view thereof, FIG. 6 is an electric circuit diagram according to an embodiment of the present invention, FIG. 7 is a time chart thereof, and FIG. 8 is a schematic plan view showing the reaping part. It is. DESCRIPTION OF SYMBOLS 1... Reaping work machine (combiner), 3... Traveling machine body, 5... Reaping part, 9... Cutting blade, 10... Cutting height sensor, 15... Sensor arm, 21a, 21b
…comparator.

Claims (1)

[Claims] 1. In a reaping work machine in which a reaping section having a reaping blade is supported on a traveling machine body so as to be movable up and down, a reaping height sensor is arranged at an appropriate position of the reaping section behind the reaping blade, and the stubble height detection result of the sensor is A mowing height control device configured to control the mowing section to move up and down by comparing the mowing height with a set value.