JP2619009B2 - Work vehicle ground height control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a work device provided on a machine body so as to be vertically movable, and a ground height detection sensor for detecting a ground height of the work device is provided by the work device. Lifting control means for automatically raising and lowering the working device so that the ground height of the working device is maintained at the target ground height based on the detection information of the ground height detection sensor. The present invention relates to a work vehicle ground height control device provided.

[Conventional technology]

The above-described work vehicle ground height control device is configured to quickly reach the target ground height when the ground height of the work device is greatly apart from the target ground height,
After reaching the target ground height, based on the deviation between the detected ground height and the target ground height, in order to prevent unnecessary lifting and lowering of the work equipment due to vibration of the aircraft and fine irregularities on the ground, etc. The lifting operation is performed at a higher lifting speed as the deviation increases.

[Problems to be solved by the invention]

Therefore, if there is a sharp unevenness on the ground in a state where the deviation between the detected ground height and the target ground height is small, the state cannot follow the sudden unevenness change because the ascending and descending speed is small. .

Therefore, it is conceivable to increase the lifting speed of the mowing part as a whole so as to be able to follow sudden irregularities on the ground, but in this case, there are disadvantages described below. That is,
In an actual field, a local dent such as a footprint of a person may be formed on the ground, and conversely, simply increasing the lifting speed may cause a local dent such as a footprint of a person. However, there is a possibility that the control may be unnecessarily followed and the control may become unstable. In other words, it is desirable to ignore local dents such as human footprints even if they are detected by the ground height detection sensor. In practice, it is necessary to minimize the amount of elevation. Desirably, a high lifting speed has the disadvantage that unnecessary lifting is performed in large amounts.

The present invention has been made in view of the above circumstances,
The purpose is to accurately follow sharp irregularities on the ground, but not to follow local dents such as human footprints.

[Means for solving the problem]

The work vehicle ground height control device according to the present invention, the work device is provided in the body so as to be vertically movable, the ground height detection sensor for detecting the ground height of the work device is provided in the work device, A device provided with elevation control means for automatically elevating and lowering the working device based on detection information of the sensor for detecting the height of the ground so that the height of the working device is maintained at a target height. And the characteristic configuration is as follows.

That is, there is provided an inclination angle sensor for detecting an inclination angle of the body in the front-rear direction, and pitching speed detection means for detecting a pitching speed of the body based on information detected by the inclination angle sensor. Is based on the deviation between the detected ground height and the target ground height and the detection information of the pitching speed detection means, when the deviation is large, it is faster than when it is small, and the deviation is the same. However, when the pitching speed is high, the ascent / descent speed is determined so as to be faster than when the pitching speed is low, and the ascent / descent operation is performed.

[Action]

When the deviation between the detected ground height and the target ground height is large, a higher ascending and descending speed is obtained than when the deviation is small, and when the ground height of the working device is far from the target ground height,
While the target ground height is quickly reached, after the target ground height is reached, unnecessary lifting and lowering of the working equipment is prevented from being performed due to vibration of the aircraft or fine irregularities on the ground. .

Then, even if the deviation is the same, when the pitching speed is high, the working device is raised and lowered to obtain a higher lifting speed than when it is low, so that there are sudden irregularities on the ground, If the aircraft is pitched at a high pitching speed due to the, the work equipment is operated up and down at a high elevating speed, and the following to the sudden unevenness becomes faster,
For example, when local unevenness such as a human footprint is on the ground and the aircraft is pitched at a slow pitching speed, the working device is operated up and down at a slow lifting speed, and the tracking of the local unevenness is slow. Become.

In addition, when the ascent / descent speed of the reaper is obtained based on the pitching speed and the deviation between the detected ground height and the target ground height, even if the deviation is small, the ascent / descent speed is not increased with the sudden increase in the pitching speed. If the detected ground height is within a set range with respect to the target ground height as described in claim 2, the speed may be raised or lowered based on the deviation regardless of the pitching speed. When the speed is calculated and the lifting operation is performed, when the deviation is small, there is little possibility that the lifting speed is unnecessarily increased with an abrupt increase in the pitching speed.

〔The invention's effect〕

Thus, it is possible to accurately follow the sudden unevenness of the ground while not following the local unevenness.

〔Example〕

An embodiment in which the present invention is applied to a cutting height control device of a reaper will be described below with reference to the drawings.

As shown in FIG. 3, a mowing part (2) as a working device is connected to a front part of the traveling machine body (1) by a single-acting hydraulic cylinder (3) so as to be able to be driven up and down freely. As a self-propelled combine.

The cutting unit (2) includes a weeding implement (4), a device (5) for causing a stem culm to be introduced from the front side as the vehicle travels, and a clipper-type cutting blade for cutting the stem of the stem culm ( 6) and a transport device (9) for transferring the cut stems to the feed chain (8) of the threshing device (7) mounted on the body (1) while changing the posture of the cut stem to the sideways posture. ing.

In addition, a non-contact type sensor for detecting the height of the ground (S ₁ ) using a reflection type ultrasonic sensor and a transport start end of the transport device (9) are transported to the reaper (2). A switch-type stock sensor (S ₀ ) is provided to detect whether or not the cutting stem is in contact with the stock of the stem.

Further, the machine body (1) is the tilt angle sensor for detecting the inclination angle in the vehicle body front-rear direction (S ₂₎ is provided.

The tilt angle sensor (S ₂ ) will be described. For example, a weight is pivotally supported around the horizontal axis in the longitudinal direction of the machine, and the rotation angle of the weight around the horizontal axis is determined by a potentiometer. Thus, it is configured to detect the inclination angle of the body (1).

A control structure for raising and lowering the mowing unit (2) will be described. As shown in FIG. 1, a neutral return biasing type control valve (10) for the lifting hydraulic cylinder (3) is used.
And a solenoid (11) for switching the control valve (10). Then, the conjunction on the basis of the inclination angle detection information of the sensor (S ₂₎ for detecting the pitching rate of the machine body (1), and detected by the pitching velocity information, detection of the ground height detecting sensor (S ₁₎ Based on the information, the mowing unit (2) is maintained at a target ground height set by a potentiometer-based target height setting device (12), and the lifting speed of the mowing unit (2) is adjusted to Determining the elevating speed so that when the deviation from the target ground height is large, it is faster than when it is small, and when the pitching speed is large, it is faster than when it is small, and the solenoid (11) A control device (13) using a microcomputer for intermittently driving the microcomputer is provided.

That is, using the control device (13), the lifting control means (100) for automatically raising and lowering the cutting unit (2)
And a pitching speed detecting means (101) for detecting a pitching speed of the body (1).

In FIG. 1, reference numeral (14) denotes a neutral return biasing type lifting / lowering operation lever which is manually operated, and is interlocked to the control valve (10) via a link mechanism (15). The control valve (11) is configured to be manually switched with priority to the solenoid (11).

However, although not described in detail, in the link mechanism, a flexibility is formed that allows the valve operation by the solenoid (11) in a state where the lifting / lowering operation lever (14) is at the neutral position (N). .

(S ₃ ) is an automatic switch for selecting whether to automatically move the reaping unit (2) up or down, or (S ₄ )
Lowering switch for detecting that the lift control lever (14) is operated in the down position (D) side, that is operated to the (S ₅₎ the lifting operation lever (14) is a raised position (U) A thrust switch for detecting, (S ₆ ), threshing for detecting that an operation lever (16) for a threshing clutch (not shown) for turning on / off the power transmission to the threshing device (7) is operated to the entrance side Switch.

If the elevation control is added, basically, as the detected ground height falls within the set dead zone with respect to the set target ground height, the raising and lowering of the reaper (2) is stopped, If it is outside the setting dead zone, it is determined whether the detected ground height is to be lowered or raised from the magnitude relationship with respect to the target ground height, and the solenoid (11) is driven in the determined vertical direction. Become.

The ON time (T _ON ) and the OFF time (T _OFF ) for intermittently driving the solenoid (11) are set such that the ascending / descending speed increases as the deviation between the detected ground height and the target ground height increases. The ratio is automatically set in accordance with the deviation and intermittent driving is performed.

However, when the airframe (1) pitches violently due to a large amount of unevenness on the ground, a setting is made in accordance with the deviation between the detected ground height and the target ground height in order to be able to follow the change in the ground unevenness. And the ON time (T _ON ) for intermittently driving the solenoid (11)
The value of the FF time (T _OFF ) is determined based on the information of the pitching speed (Δθ) detected from the detection information of the inclination angle sensor (S ₂ ), as the pitching speed (Δθ) increases, the lifting speed decreases. In such a case, automatic correction is performed.

Next, the operation of the control device (13) will be described in detail based on the flowchart shown in FIG.

However, in the automatic lifting control, the automatic switch (S ₃ ) is turned on and the automatic mode is selected, and the stock sensor (S ₀ ) and the threshing switch (S ₆ )
When both are in the ON state and the mowing work is being performed, the processing is repeatedly executed at set time intervals.

When the control operation is started, a deviation between the ground height detected by the ground height detecting sensor (S ₁ ) and the target ground height is obtained, and based on the obtained deviation, the larger the deviation is, the larger the deviation becomes. The ON time (T _ON ) and the OFF time (T _OFF ) of the solenoid (11) are read from a table for setting the elevating speed which is set and stored in advance so as to obtain the elevating speed.

Next, a pitching speed (Δθ) is detected based on the detection information of the inclination angle sensor (S ₂ ). If you add a description,
The pitching speed (Δθ) is calculated based on the difference between the previous detection value of the inclination angle sensor (S ₂ ) and the current detection value.

Then, based on the pitching speed (Δθ), the ON time (T _ON ) and OFF of the solenoid (11) are set so that the higher the determined pitching speed (Δθ), the higher the elevating speed.
The time (T _OFF ) is corrected based on the following equations (i) and (ii), and as the deviation from the target ground height increases, the ascending and descending speed increases, and the detected pitching speed (Δ
The solenoid (11) is intermittently driven so as to control the raising and lowering of the reaping unit (2) so that the raising and lowering speed increases as θ) increases.

T _ON = A · Δθ · T _ON (i) T _OFF = B · Δθ · T _OFF (ii) where A and B are proportional constants, respectively.

(Another embodiment)

In the above-described embodiment, the case where the ascending and descending speed of the mowing unit (2) is constantly corrected according to the magnitude of the obtained pitching speed (Δθ) is exemplified. If the height is within the set range, the vertical movement may be performed based on the deviation between the detected ground height and the target ground height, regardless of the pitching speed.

In addition, a table of the ascending and descending speeds in which the ascending and descending speeds are made different in two stages, large and small, with respect to the deviation between the same ground height and the target ground height is prepared in advance.

Then, as shown in FIG. 4, a deviation between the detected ground height and the target ground height, and a pitching speed (Δθ) are obtained.

Next, it is determined whether or not the deviation is smaller than a preset set value (α). If the deviation is smaller, a table with a smaller elevation speed is selected and the solenoid (11) is selected. of
Set each of ON time (T _ON ) and OFF time (T _OFF ).

That is, when the deviation is within a range smaller than the set value (α), a table having a small elevation speed is selected regardless of the pitching speed (Δθ), and the elevation speed is obtained based on the deviation. .

On the other hand, if the deviation is equal to or greater than the set value (α), it is determined whether the obtained pitching speed (Δθ) is equal to or greater than a set value (β) for determining that the pitching is large. I do.

When the pitching speed (Δθ) is equal to or greater than the set value (β), a table having a large elevation speed is selected, and the ON time (T _ON ) and the OFF time (T _OFF ) of the solenoid (11) are selected. ), And set the pitching speed (Δ
If θ) is smaller than the set value (β), the table with the lower elevation speed is selected, and the table of the solenoid (11) is selected.
The ON time (T _ON ) and the OFF time (T _OFF ) are set.

Further, in the above-described embodiment, the case where the sensor for detecting the ground height (S ₁ ) is constituted by using the ultrasonic sensor is exemplified. However, for example, the ground that moves up and down according to the ground height of the reaper (2) is used. A contact-type sensor using a body or the like may be used, and the specific configuration of each part such as the specific configuration of the sensor for detecting the height of the ground (S ₁ ) may be variously changed.

INDUSTRIAL APPLICABILITY The present invention can be applied to ground height control of a work vehicle other than a reaper.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[Brief description of the drawings]

Drawings show an embodiment of a work vehicle ground height control device according to the present invention, FIG. 1 is a block diagram of a control configuration, FIG. 2 is a flowchart of a control operation, FIG. 3 is a schematic side view of a reaper,
FIG. 4 is a flowchart of a control operation in another embodiment. (S ₁ ): A sensor for detecting the height of the ground, (S ₂ ): An inclination angle sensor, (1): Airframe, (2): Working device, (100)
... Elevation control means, (101)… pitching speed detection means.

Claims (2)

(57) [Claims] A working device (2) is provided on a body (1) so as to be vertically movable, and a ground height detecting sensor (S ₁ ) for detecting a ground height of the working device (2) is provided with the working device. (2), based on the detection information of the ground height detection sensor (S ₁ ), the working device (2) so that the ground height of the working device (2) is maintained at the target ground height. 2) A work vehicle ground height control device provided with a lift control means (100) for automatically raising and lowering a vehicle body (2), wherein a tilt angle sensor for detecting a tilt angle of the body (1) in a front-rear direction. (S ₂ ) and pitching speed detecting means (101) for detecting the pitching speed of the body (1) based on the detection information of the inclination angle sensor (S ₂ ), and the elevation control means (100) The deviation between the detected ground height and the target ground height, and the pitching speed detection Based on the detection information of the means (101), when the deviation is large, it is faster than when it is small, and even when the deviation is the same, when the pitching speed is large, it is faster than when it is small. Height control device for a working vehicle configured to calculate the lifting speed and perform the lifting operation. 2. The work vehicle ground height control device according to claim 1, wherein the elevation control means (100) has the detected ground height within a set range with respect to the target ground height. In this case, a work vehicle height control device configured to obtain a lifting speed based on the deviation and perform a lifting operation regardless of the pitching speed.