JPS6017482B2 - Combine cutting height adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combine harvester that automatically adjusts the cutting height using a hydraulic device that responds to a command from a detection device that detects the height above the ground.

Conventionally, this type of adjustment device existed in which a detection device for detecting the height above the ground was located behind the cutting blade.
Since reaping and threshing work is normally performed when the machine is moving forward, the cutting blade moves forward before the detection device.

Therefore, with conventional structures like this, if there is a protrusion in the field, the cutting blade will collide with the protrusion in the field, or it will sink into the field and cut the mud, causing significant wear on the cutting blade. There was a drawback that it could be damaged or damaged. On the other hand, if there is a recess, after the cutting blade has cut the grain,
Since this concave portion is detected, there is a drawback that the cutting height becomes high and it is extremely difficult to maintain a constant cutting height. In addition, conventionally, there was a device in which a ground height detection device was located in front of the lifting start end of the lifting device, but with such a structure, when the grain stalks are collapsed and tangled, Due to the influence of the lodging grains, the height above the ground relative to the field cannot be accurately detected, and the cutting height also cannot be maintained constant.
Alternatively, there is a method that solves the above-mentioned problem by installing a height-above-the-ground detecting device between the cutting blade and the pulling device, but the conventional height-above-the-ground detecting device installed there uses a sensing sled body, etc. Because the sled used was a contact type, it had the disadvantage that in soft fields, the sled body would sink into muddy soil, causing malfunctions, and would be prone to breakdowns because it was constantly pressed against the field.

Another problem with conventional cutting height adjustment devices is that the so-called dead zone, which prevents the cutting height from being adjusted as long as the cutting height is within an appropriate range, remains unchanged. Therefore, there was the following drawback.

That is, although it is possible to adjust high or low cutting by changing the appropriate cutting height up or down within the range, conventionally, the height above ground detection device itself is mechanically provided so that its vertical position can be changed freely. Therefore, it required a fairly complicated position change fixing device, and furthermore, it had the disadvantage that adjustment operations were troublesome.

Furthermore, when the appropriate cutting height range is set narrowly, when unevenness in the field becomes short and continues at a pitch, the cutting height is repeatedly adjusted in a short period of time. Therefore, while it is preferable for the original cutting height adjustment,
The shock associated with the vertical movement of the pre-processing section tends to cause fatigue to the operator, and on the other hand, if the cutting height is set widely within the appropriate cutting height range, there is no point in automatically controlling the cutting height adjustment. . The present invention eliminates such drawbacks of the conventional art, and provides practicality that allows mowing height setting operations to be performed relatively simply and easily, and allows stable and highly accurate cutting height adjustment to be performed at all times with fewer failures. It is an object of the present invention to provide a high cutting height adjustment device.

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

In FIG. 1, 1 is a combine harvester for reaping and threshing grains in a standing position, and 2 is a lifting device installed obliquely at the front of the machine, which raises the standing grains to a substantially upright position.

Reference numeral 3 denotes a cutting blade that performs a reaping action at the stock base of the grain stake pulled up by the pulling device 2, and this cutting blade 3 is located rearward from the lifting start end of the lifting device 2. and 4 is a conveyance device for conveying the harvested hardwood. Next, reference numeral 5 is a hydraulic cylinder, and the operation of this hydraulic cylinder 5 moves the pretreatment section 7, which includes the above-mentioned lifting device 2, cutting blade 3, conveying device 4, etc., toward the main body of the machine about the pivot point A. Move it up and down to change the cutting height. 8 is an ultrasonic type non-contact ground height detection device, which includes a transmitter that transmits ultrasonic waves, and a receiver that generates a voltage by receiving the reflected waves from the transmitted ultrasonic waves that hit the field. The cutting height detection value based on the height above the ground is output as a voltage Vs which becomes higher as the height above the ground is lower.

In particular, in the present invention, the detection device 8 is located between the lifting start end of the lifting device 2 and the cutting blade 3 in side view. Note that this detection device 8 is configured such that the lower the height from the ground, the higher the detection voltage Vs.

In addition, as a non-contact type detection device, instead of the ultrasonic type described above, a capacitive method (for example, a voltage is applied to the field and the sensing body through a chain hanging over the field, and the capacitance change between the field and the sensing body is detected) It is possible to use a photoelectric type (converting to a voltage value) or a photoelectric type.

FIG. 2 is a block diagram showing the operating sequence of cutting height adjustment.
p,, Comp2, where it is compared with a preset signal (setting value), and this comparison circuit Comp,,C
A mowing height adjustment signal is generated through omp2, and this signal is sent to a solenoid valve 9 of a hydraulic device 6, which will be described later, to operate a hydraulic cylinder 5 to adjust the mowing height. Third
The figure shows an electric circuit that operates a solenoid valve 9 based on a signal detected by the non-contact detection device 8, and a hydraulic device 6 that adjusts the cutting height in accordance with the operation of the solenoid valve 9. It is an explanatory diagram.

In the figure, the first and second comparison circuits Comp,,C
The detection voltage Vs detected by the non-contact detection device 8 is applied to the positive terminal of omp2, and the negative terminal thereof is
The constant voltage yst is divided by the variable resistors R, , R2 (which is an example of a set value adjuster), and the voltage V, .
V2 is applied. In this embodiment, the voltage V applied to the first comparator circuit Comp, divided by the variable resistor R, is applied to the second comparator circuit Comp2, which is also divided by the variable resistor R2. It is set in advance to be smaller than the applied voltage V2 (V.<V2). Also,
The comparison circuits Comp, Comp2 each operate to generate an output voltage only when the voltage applied to the positive terminal is higher than the voltage applied to the negative terminal. Therefore, for example, in the first comparison circuit Comp, the variable resistor R,
The voltage V divided by
An output voltage is generated when the voltage Vs applied to the positive terminal is higher than the voltage Vs applied to the positive terminal. On the other hand, when the cutting height adjustment signal is applied to one of the solenoids SOL, SOL of the electromagnetic valve 9, the hydraulic system 6 switches the oil passage and operates the hydraulic cylinder 5 to move the pre-processing section 7 to the pivot point. The mowing height is changed by raising and lowering the machine body centering on point A.Next, the operation of the above embodiment will be explained.

Ultrasonic waves are emitted toward the field from the transmitting section of the height above ground detection device 8, and the reflected waves are received by the receiving section to generate voltage Vs, and this detected voltage Vs is sent to the first and second comparison circuits Co.
mp, , is applied to the positive side terminal of Comp2. Voltages y and V2, which are obtained by dividing the constant voltage yst by variable resistors R and R2, respectively, are applied to the other member side terminal. (
Incidentally, as mentioned above, in this embodiment, it is determined that V<V2. ) this V, to V2 range (V.
<Vs<V2) is the appropriate cutting height range as described later, the upper limit of which can be set by the voltage V, and the lower limit of which can be set by the voltage V2.In other words, the variable resistor is The correct cutting height range setting means R, , R2 allows the set values of the upper and lower limits to be easily changed by changing the divided voltages V, , V2. In other words, by changing the divided voltages V and V2, the set values of the upper and lower limits of the appropriate cutting height range can be changed.

Therefore, by changing the voltages V and V2 to the same value, the appropriate cutting height range can be changed up or down without changing, and the cutting height can be adjusted to high or low cutting. .

By changing the voltage value of either one of the voltages V, , V2, the setting value of either the upper limit or the lower limit can be changed, and of course, the voltage value of both voltages V, , V2 can be changed. Both the upper and lower set values can be changed by using the variable resistors R, , R2, and the appropriate mowing height range can be moved up and down while remaining within the range. or even narrower or wider the top and bottom.

Moreover, the above setting value changing operation is performed using the variable resistors R, .
This can be done simply and easily by adjusting the partial pressure for R2. Next, “the comparison circuit Comp, , Comp
Detection voltage Vs applied to 2 and divided voltage V,,V
The relationship between ■ V. <V2<detection voltage Vs, ■V. <Detection voltage Vs<V2, ■Detection voltage Vs<V. <V2, two cases will be explained below.

■V. <V2<detection voltage Vs, that is, when the height above the ground is too low, the first and second comparison circuits Comp. ，
An output voltage is issued to Comp2, and the transistors Tr,
, Tr2 are energized to relays Ry, , Ry2, so that relay switch SW, is opened and relay switch SW2 is closed.

Therefore, the solenoid SOL2 of the electromagnetic valve 9 is energized by the power source E to switch the oil path, and the pretreatment section 7 is raised relative to the main body of the aircraft about the pivot point A by the operation of the hydraulic cylinder 5. As this increase continues, the detection voltage Vs detected by the height above the ground detection device 8 decreases, but when this detection voltage Vs falls within the range of V, < Vs < V2, due to the reason described in the next The lifting of the processing section 7 will be stopped. ■V. <Detection voltage Vs<V2
In this case, that is, when the height above the ground is within a preset range (within the appropriate cutting height range), the second comparator circuit Comp2 determines that the voltage V2 applied to the negative terminal is higher than the voltage V2 applied to the positive terminal. Since it is larger than the applied detection voltage Vs, no output voltage is generated.

Therefore, relay Ry2 is energized and shear switch SW2
remains open. On the other hand, the first comparison circuit Comp,
Since Vs>V, an output voltage is generated. Therefore, relay Ry is energized via transistor Tr, and relay switch SW is opened. Therefore, both relay switches SW, SW2 are opened, so the electromagnetic valve 9 is not energized and the hydraulic cylinder 5 is not operated, so the pre-processing section 7
will be held in the same position.

■ Detection voltage Vs<V. <V2, that is, when the height from the ground is too high. In this case, no output voltage is generated in the first and second comparison circuits Comp, Comp2.

This is because the voltages (V and V2) both applied to the negative terminals are larger than Vs. Therefore, relay Ry
, , Ry2 are both not energized. Relay switch SW2
is a so-called a contact and remains open when there is no signal, but the relay switch SW is a so-called b contact and remains closed when there is no signal. Therefore, the solenoid SOL of the electromagnetic valve 9 is energized by the power source E to switch the oil path, and the pretreatment section 7 is lowered about the pivot point A by the operation of the hydraulic cylinder 5. As this downward movement continues, the height above ground detection device 8 also continues to fall, and the detection voltage Vs also increases. If this detection voltage Vs is within a preset range, that is, V, Vs<
When the temperature falls within the range of V2, the lowering of the pre-processing section 7 is stopped for the reason stated in section (3). In this way, the cutting height of the grain stalk is adjusted. The detection device 8 is located between the starting end of the lifting device 2 and the cutting blade 3, and the detection device 8 is located between the starting end of the lifting device 2 and the cutting blade 3, , is configured to detect the height above the ground before the cutting blade 3, so even if the field is uneven, or if the grasses are lying down and intertwined,
The mowing height can always be adjusted at a constant level, and since the detection device 8 is of a non-contact type, the height above the ground can be accurately detected even in soft fields, and the cutting height can be stabilized without malfunction. control.

The mowing height setting operation is also performed by the comparison circuit Comp.
, Comp2 can be simply and easily done by changing the voltages V, , V2 to Comp2.

In other words, when the irregularities in the field are short and continue at a pitch,
If the upper and lower portions of the appropriate cutting height range are short, the cutting height is adjusted repeatedly in a short period of time, which is good for the original cutting height adjustment, but the upper and lower shocks tend to cause fatigue to the operator. In such a case, by widening the upper and lower middle of the appropriate cutting height range (preferably by increasing the upper limit set value in order to prevent wear of the cutting blade 3), the cutting height adjustment may be slightly sacrificed, but operation will be made easier. If you are forced to cut, or if the pitch of unevenness is large and the situation is relatively gentle, you can easily adjust the cutting height by reducing the upper and lower middle of the appropriate cutting height range. Therefore, it is possible to adjust the cutting height and take a control form suitable for operation depending on the field conditions.

As is clear from the above description, the cutting height adjusting device for a combine harvester according to the present invention has a detection mechanism that detects the ground height between the pulling start end of the pulling device and the cutting blade when viewed from the side. Because it is positioned in the same position as the conventional structure mentioned at the beginning, there are no drawbacks such as the cutting blade colliding with the convex part of the field and being damaged, or the cutting height becoming uneven. This allows stable cutting height adjustment at all times. In addition, since the detection device is a non-contact type, stable adjustment can be made without malfunction even in weak fields, and its durability is dramatically increased. be able to. Furthermore, a comparison circuit is provided for comparing a detection signal from the detection device with a setting signal from a setting value adjuster whose upper and lower limit settings of the appropriate cutting height range can be changed and adjusted. The mowing height is adjusted by operating a solenoid valve, so by setting the appropriate mowing height range appropriately according to field conditions, it is possible to place emphasis on operability or mowing height. As a result, it has become possible to take control forms such as An important point in the present invention is that the operating signal given to the solenoid valve from the comparison circuit is the pressure oil that raises the pre-treatment section when the detection value of the detection device is greater than the upper limit set value of the appropriate cutting height range. Conversely, when the detected value is smaller than the lower limit set value of the appropriate cutting height range, the supply circuit is switched to the side that forms the pressure oil supply circuit that lowers the pretreatment section, and the detected value is set to the upper limit set value. When the pressure is between the pre-treatment part and the lowering set value, both of the pressure oil supply circuits for raising and lowering the pre-treatment section are closed. The pretreatment section is raised and lowered along these irregularities with high precision, and thereby the above-mentioned advantages can be obtained even more effectively.

In other words, unlike paved roads, the degree of unevenness in the field is very frequent and in small steps, and in short, the field is a series of unevenness all over, and a phenomenon in which depressions appear during the rise of the pre-treatment section based on the detection of the protrusions. is frequently seen.
Therefore, in a combine harvester that is forced to work under such special conditions, if the detected value exceeds the upper and lower limit settings, as shown in Utility Model Application Publication No. 49-57796, the upper and lower limits will be exceeded. If you try to adjust the cutting height by using a control means that brings the controlled object close to the median of the lower limit set values, for example, based on the detection of a convex part, the pre-processing device will adjust the height to the median of the upper and lower limit set values. When the next concavity appears, the detection value becomes much lower than the lower limit set value, causing a delay in the descending control of the pre-processing section. As a result, the pre-treatment unit is raised and lowered with a delay in response to the actual unevenness changes in the field, making it difficult to perform highly accurate cutting height control. This means that only devices with similar inconveniences can be provided. However, in the present invention, as described above, the preprocessing section is moved up and down only when the detected value is outside the range of the upper and lower set values, and when the detected value is within the range of the upper and lower set values, the preprocessing is performed. Since the pre-treatment section is prevented from moving up and down, the inconveniences seen in the above-mentioned conventional technology do not occur, and the pre-treatment section can be moved up and down to follow the actual irregularities of the field, allowing for highly accurate cutting height adjustment. This has the special effect of making it possible to achieve the above-mentioned advantages even more effectively. BRIEF DESCRIPTION OF THE DRAWINGS The drawings show one embodiment of the present invention, in which Fig. 1 is an overall side view of the combine, Fig. 2 is a block diagram, and Fig. 3 shows an electric/hydraulic circuit controlling the operation of the main part. It is a diagram.

1... Combine harvester, 2... Pulling device, 3... Cutting blade, 6... Hydraulic device, 7...
...Pre-processing section, 8...Detection device, 9...
····solenoid valve.

Figure 2 Figure 3 Figure 1

Claims (1)

[Claims] 1. A pre-processing section which has a cutting blade 3 for reaping the base of the grain culm and a pulling device 2 whose starting end is positioned in front of the cutting blade 3, and which is pivotally supported on the main body of the machine. 7, a detection device 8 that detects the ground height, and a hydraulic device 6 that adjusts the cutting height by raising and lowering the pretreatment section 7 in accordance with the operation of a solenoid valve 9. In this case, the detection device 8 is located between the lifting start end of the lifting device 2 and the cutting blade 3 in a side view, and the detection device 8 is configured as a non-contact type detection device. A comparison circuit Comp_ that compares the detection signal from the detection device 8 with the setting signal from the setting value regulators R_1 and R_2, in which the setting value of at least one of the upper limit and the lower limit of the cutting height range can be changed and adjusted.
1, Comp_2 is provided, and this comparison circuit comp_1,
In configuring the solenoid valve 9 to operate based on the signal from Comp_2 to adjust the cutting height,
From the comparison circuits Comp_1 and Comp_2 to the solenoid valve 9
The signal given to energizes the pre-processing part rising side solenoid SoL_2 only when the mowing height detection value by the detection device 8 falls below the lower limit mowing height setting value, and the mowing height by the detection device 8 is increased. Only when the detected value exceeds the upper limit cutting height setting value, the pre-processing section lowering side solenoid So
A cutting height adjustment device for a combine harvester, characterized in that it is configured to excite L_1.