JPH0160213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reaping harvester, and more specifically, to control the reaping height, the present invention has a sensor for detecting the height of the reaping section above the ground, and the height above the ground detected by this sensor is controlled. The present invention relates to a reaping harvester including means for automatically controlling the elevation of the reaping section to maintain it at a target value.

Conventionally, in this type of reaping and harvesting machine, the cutting height is adjusted to a predetermined height by raising and lowering the reaping section based on the height above the ground detected by the height above the ground sensor. control is in place. In order to prevent hunting in the control response to the set mowing height, that is, the control target, a predetermined tolerance (dead zone) is provided, but if this tolerance is a constant value with a relatively wide range, As a result, there were the following inconveniences.

That is, at the start of the reaping operation, the actual height of the reaping section above the ground is often significantly different from the normal control target value, and the reaping section is controlled by raising and lowering to match the target value. If the detected height above the ground matches the target value within the relatively wide tolerance range mentioned above, the elevation is stopped, so the actual height detected above the ground does not match the target value, and the position is lower than the target value. When the reaping section is stopped, there is an inconvenience that the reaping section may plunge into the ground in some cases.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a reaping harvester equipped with a control means that allows the actual height of the reaping section to match the target height above the ground from the start of the reaping operation. Our goal is to provide the following.

In order to achieve the above object, the reaping harvester according to the present invention is provided with a sensor that detects the presence or absence of grain culm introduced into the reaping section, and based on the detection result of the presence or absence of grain culm introduction by this sensor. Start of reaping work
Means for automatically narrowing the control tolerance with respect to the target ground height when controlling the reaping section up and down during the non-operation after determining the stoppage and until a predetermined time has elapsed from the start of the operation than during the subsequent reaping operation. It is characterized by the fact that it is provided with.

Because of the above characteristics, the following excellent effects have been achieved.

In other words, until a predetermined period of time has elapsed from the start of reaping work, the control tolerance for the target value is narrow, so the actual height above the ground of the reaping section at the beginning of reaping matches the target value better, resulting in optimal reaping. Since you can start work at a certain height, you can not only prevent the danger of accidentally pushing the cutting part into the ground, but also be able to work at a predetermined cutting height from the start of work, which allows you to adjust the cutting height. This made it possible to avoid unevenness. In addition, after a predetermined period of time has elapsed, the reaping section is raised and lowered using normal tolerances, so there is no need to directly follow small irregularities on the ground.
Therefore, the maintainability and controllability of the target height above the ground has been extremely improved without causing hunting.

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

FIG. 1 is a side view of a reaping section 1 at the front of a combine as a reaping/harvesting machine. A weeding tool 5 is provided in front of the weeding tool 5, and the lower end tip of the weeding tool 5 is fixed to a support frame 6 of the reaping device 1. An ultrasonic sensor 9 as a ground height detection sensor consisting of a transmitter 7 and a receiver 8 is mounted behind the weeding tool 5 and above the support frame 6 to prevent malfunctions caused by grain culms. By operating the hydraulic cylinder 10 based on the height detection result from the ground by the ultrasonic sensor 9 and swinging the reaping section 1 around the horizontal axis P. It is configured to adjust the cutting height.

Furthermore, a switch is provided as a sensor that detects the start and stop of the reaping work by detecting the presence/absence of the grain culm introduced from the front into the lower part of the lifting device 2, which is turned on and off as the grain culm comes into contact with the grain culm. A stock sensor S ₀ configured as follows is provided.

A control system for controlling the cutting height based on the height above the ground detected by the ultrasonic sensor 9 will be described below.

As shown in FIG. 2, the control system inputs the signal from the receiver 8 of the ultrasonic sensor 9 to a control device 11 whose main part is a microcomputer, and also sets the cutting height (height above the ground) in advance. The output signal of the potentiometer 12 and the output signal of the stock sensor _S0 as a means for
The electromagnetic valve 13 is driven so that the height H above the ground detected by the receiver 8 becomes the reference target value H ₀ set by the potentiometer 12, and the reaping part 1 is automatically operated by the hydraulic cylinder 10. It is designed to be raised and lowered in a controlled manner.

Then, in response to the ON/OFF state of the stock sensor S ₀ , the control tolerance Δ with respect to the target value H ₀ is changed from the normal tolerance D ₁ until a predetermined time t has elapsed from the start of the reaping operation. The vertical movement of the reaping section 1 is controlled by automatically switching to the narrow tolerance _D2 .

That is, when the signal from the stock sensor S ₀ is checked and this sensor S ₀ is OFF, the flag (AHC mode) is set to "1" until a predetermined time τ has elapsed after changing from ON to OFF. ” to set the tolerance Δ to a tolerance D ₂ that is narrower than normal, and when the sensor S ₀ is ON and a predetermined time τ has elapsed, the flag (AHC mode) is reset to “0” and the normal state is set. This will restore the tolerance D to ₁ .

Therefore, until the predetermined time τ has elapsed from the start of the reaping operation, the reaping unit 1 is automatically raised and lowered with a narrow tolerance D ₂ for the cutting height control, so that the target value H ₀ of the reaping unit 1 is maintained. The consistency of the actual ground height H with respect to
Since it is controlled by _D1 , hunting does not occur in the control response.

By the way, in the cutting height control in this embodiment,
In order to optimize the control response, the drive gain of _the electromagnetic valve 13 (intermittent drive pulse current
By automatically changing the ON/OFF ratio, etc., into multiple stages, the larger the deviation ΔH, the faster the mowing unit 1 can be moved up and down. This drive gain G, together with the tolerances D ₁ and D ₂ , is stored in a table in advance in a memory (not shown) in the control device 11 .

FIG. 3 is a flowchart showing the operation of the control device 11 described above, which not only controls the cutting height but also checks the status of other sensors (threshing switch, automatic/manual changeover switch, etc.). Control flags for other controls are also set using the control flag.

Moreover, FIG. 4 shows the drive gain G and tolerance Δ
This is the table.

By the way, as for the predetermined time τ, since the stock sensor S ₀ is turned on and off by contact with the grain culm, as the aircraft moves,
Since the ON signal is output intermittently by repeating ON and OFF intermittently, the time is set to be longer than the time corresponding to the period of repetition.
In order to prevent malfunctions, the setting may be based on the traveling speed, the planting interval of grain culms, etc.

In addition, after the detected height H above the ground converges within a narrow tolerance _D2 with respect to the target value _H0 , it is configured to automatically return to the normal tolerance _D1 , so that the target value _H0 is substantially reduced.
It may also be set to the time required for control to collect data.

[Brief explanation of drawings]

The drawings show an embodiment of the reaping harvester according to the present invention, FIG. 1 is a front side view of the combine, FIG. 2 is a block diagram of the control system, FIG. 3 is a flowchart showing the operation of the control device, and , FIG. 4 is a table of control gains and tolerances. 1... Reaping section, 9... Ground height detection sensor,
S ₀ ... Grain culm detection sensor, τ... Predetermined time, H ₀
...Target height above ground, H...Detected height above ground, Δ...
tolerance.

Claims (1)

[Claims] 1 In order to control the cutting height, a sensor 9 that detects the height of the cutting section 1 from the ground is provided, and this sensor 9
The reaping/harvesting machine is equipped with means for automatically controlling the elevation of the reaping section ₁ in order to maintain the height H above the ground detected by - A sensor S ₀ is provided to detect the presence of grain culms, and based on the detection result of presence/absence of grain culms by this sensor S ₀ , it is determined whether to start or stop the reaping operation, and the operation is performed during non-operation and until a predetermined time τ has elapsed from the start of the operation. is the target value H ₀ when controlling the elevation of the reaping section 1
A reaping/harvesting machine characterized by being provided with means for automatically narrowing a control tolerance Δ during subsequent reaping operations.