JPH0837865A - Vertical motion controlling apparatus for working vehicle - Google Patents

Abstract

PURPOSE:To provide a vertical motion controlling apparatus for a working vehicle capable of performing the control of a vertical motion in an adequate state when the vehicle moves even on a non-working ground having vigorous unevenness before it begins running on a working field. CONSTITUTION:The working vehicle is provided with a controlling apparatus 12 for a hydraulic cylinder CY driving a vertical motion so that the height of a working apparatus from the ground is adjusted to a predetermined height based on information obtained by an ultrasonic sensor S1. The working vehicle is also provided with a plant-root ultrasonic sensor S0 for distinguishing a working state from a nonworking state of the working apparatus. During the sensor S0 is detecting a non-working state or during a predetermined period of time after the sensor S0 detected the shift from the non-working state to a working state, the control sensitivity for a vertical controlling motion based on the information detected by the supersonic sensor S1 is set high. When the predetermined period of time has passed after the shift, the control sensitivity is set low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting control device for a working vehicle such as a combine and other agricultural working vehicles, and more specifically, to an actuator for lifting and lowering the working device and a ground height of the working device. Work vehicle provided with ground height detection means and control means for controlling the actuator so that the ground height of the working device becomes a target height based on the detection information of the ground height detection means. Lifting control device.

[0002]

2. Description of the Related Art Conventionally, in a lifting control apparatus for a work vehicle, a lifting control operation based on a detection result of a ground height detecting means is executed with high accuracy with respect to slight unevenness of the ground during work traveling. As a result, the work device frequently repeats unnecessary lifting and lowering operations, and there is a disadvantage in that smooth control cannot be executed, such as when the vehicle body fluctuates.
The control sensitivity of the lifting control operation was set to be insensitive.

[0003]

By the way, for example, in an agricultural work vehicle, in a work site where work such as mowing work and ground work is performed, the work is usually performed while the vehicle body travels straight in one work stroke. In many cases, the ground is not roughened, but in a headland where the vehicle body turns and runs, there is a great possibility that the ground surface is roughened due to the turning motion of the vehicle body and there are many irregularities.

Therefore, when the work in the work stroke is started next time while traveling on the non-work ground such as the headland where the ground is thus rough, the above-described insensitive lifting control operation is executed. Then, the lifting control operation may not be able to follow up and down the work device to the ground caused by the unevenness of the ground, and the work device may accidentally contact the ground, damaging the work device or causing damage to the ground. There were some disadvantages such as roughening, and there was room for improvement.

The present invention has been made paying attention to such a point, and an object thereof is to start the work traveling.
An object of the present invention is to provide a lifting control device for a work vehicle that can perform the lifting control operation in an appropriate state even when the vehicle body travels on a non-working ground where the ground is highly uneven.

[0006]

The features of the first invention are as follows:
Based on the actuator for operating the work device up and down, the ground height detection means for detecting the ground height of the work device, and the detection information of the ground height detection means, the ground height of the work device is the target height. As described above, a lifting control device for a work vehicle provided with a control means for controlling the actuator, the working state detecting means for detecting whether the working device is in a working state or a non-working state. The control means is provided, while the working state detecting means detects the non-working state, and from when the non-working state is switched to the working state for a set time period. Or, until the vehicle travels the set distance, the control sensitivity of the lifting control operation based on the detection information of the ground height detecting means is sensitively changed and set, and the working state detecting means switches from the non-working state to the working state. From the time it is detected that the Wow,
After the set time has elapsed, or after traveling the set distance, the control sensitivity of the lifting control operation is set to be insensitive.

The characteristic configuration of the second invention specifies a configuration suitable for carrying out the first invention, and vehicle speed detection means for detecting the traveling speed of the work vehicle is provided, and the control means is
If the traveling speed detected by the vehicle speed detecting means is equal to or lower than a set speed, from the time when the working state detecting means detects that the working state is switched to the working state, after a set time has passed, or The point is that the control sensitivity of the lifting control operation is sensitively changed and set after traveling the set distance.

A characteristic configuration of the third invention is to specify a configuration suitable for carrying out the first or second invention, wherein the control means is based on an average value of detection values of the ground height detection means. Is configured to obtain the detected ground height of the working device, and the amount of detection information of the detection value of the ground height detecting means for obtaining the average value is changed to control the lifting control operation. It is configured to change the sensitivity to be sensitive or insensitive.

The characteristic configuration of the fourth invention is to specify a configuration suitable for carrying out the first, second or third invention, and the ground height detecting means intermittently executes the detecting operation. The control means, when obtaining the average value of the plurality of detection values in the ground height detection means, by changing the parameter, the control sensitivity of the lifting control operation, sensitive or insensitive. It is configured to be changed and set.

The characteristic configuration of the fifth aspect of the invention specifies a configuration suitable for carrying out the first, second or third aspect of the invention, in which the ground height detecting means detects an operation every set unit time. Is configured to execute, the control means, the average value for each set time of the detection value in the ground height detection means, or based on the average value for each set distance traveled, the detection ground of the working device. The height is set to obtain the average value, the setting time or the setting distance for obtaining the average value is shortened, the control sensitivity of the lifting control operation is sensitively changed and set, and the setting time or the setting distance is set. Is made longer, and the control sensitivity of the lifting control operation is set to be insensitive.

The characteristic constitution of the sixth invention is that the first, second and third
Or, a configuration suitable for carrying out the fifth aspect of the invention is specified, wherein the control means detects an average value of detection values in the ground-height detection means for each set time or each time the vehicle travels a set distance. The height is determined as the ground height, and the elevation control is executed based on the detected ground height so that the control sensitivity of the elevation control operation is sensitively changed and set, and the detection by the ground height detection means is performed. A plurality of values obtained in the second set time or in the time set to travel the second set distance by obtaining the average value of the values for each set first time or each time the set distance travels Of the first average values except the maximum value and the minimum value, the average value of the other first average values is obtained as the second average value, and the lifting control is executed based on the second average value. Insensitive to the control sensitivity of the lifting control operation In that it is configured to change settings.

The characteristic configuration of the seventh invention is to specify a configuration suitable for carrying out the first invention, wherein the control means is
By setting the operating speed of the actuator to the high speed side, the control sensitivity of the lifting control operation is sensitively changed and set,
By setting the operating speed of the actuator to the low speed side, the control sensitivity of the elevation control operation is insensitively changed and set.

[0013]

According to the characterizing feature of the first aspect of the invention, the set time is set while the work state detecting means detects the non-work state and when the change from the non-work state to the work state is detected. While the vehicle is running, or until it travels the set distance, that is, when the work vehicle travels on the non-working ground and starts working in the working stroke until it enters the working ground, the height of the ground is detected. The control sensitivity of the lifting control operation based on the detection information of the means is set sensitively. As a result, even when the work equipment moves up and down frequently due to changes in the posture of the work vehicle on the non-working ground, the lift control sensitivity becomes sensitive. Can be maintained at the target height as much as possible.

Then, after the set time has elapsed or after the set distance has been traveled, that is, when the work travel at the work site is being performed, the lift control sensitivity is set to be insensitive and unnecessary. It is possible to perform smooth control by avoiding the simple elevation control as much as possible.

According to the characteristic construction of the second invention, the following operation is provided in addition to the operation of the characteristic construction of the first invention. After the set time has elapsed, or after traveling the set distance, that is, even when the work traveling at the work site is performed,
In a place with a lot of unevenness on the ground, the traveling speed will be slowed down from the viewpoint of work safety, so if such a traveling speed is low, raising and lowering control sensitivity will make the work speed sensitive. The ground height of the device can be maintained at the target height as much as possible.

According to the characterizing feature of the third invention, the following effect is obtained in addition to the effect of the characterizing feature of the first or second invention.
The detected ground height of the work device is obtained based on the average value of the detection values detected by the ground height detection means. Then, the detection information amount of the detection value for obtaining the average value, that is, the length of the detection time of the averaged detection value, the number of detection values, etc. are changed, and the control sensitivity is set to be sensitive or insensitive. Of.

According to the characteristic configuration of the fourth invention, the first and second aspects are provided.
Alternatively, the following operation is provided in addition to the operation according to the characteristic configuration of the third invention. The detection operation by the ground height detecting means is performed intermittently, and when obtaining the average value of the plurality of detection values thus detected, the parameter, that is, the number of averaged detection values is changed. Thus, the control sensitivity is set to be sensitive or insensitive. For example, by increasing the number of parameters, even if a large value is detected locally, by changing the number of parameters, the average value is averaged, and smooth detection value information with little fluctuation can be obtained. As a result, the control sensitivity of the lifting control operation becomes insensitive. Also, if you reduce the parameter,
The followability of the lifting control to the detection information is improved, and the control sensitivity becomes sensitive.

According to the characteristic constitution of the fifth invention, the first and second
Alternatively, the following operation is provided in addition to the operation according to the characteristic configuration of the third invention. The detection operation by the ground height detecting means is performed every set unit time, and the average value of the detected values for each set time, or
The detected ground height of the work device is obtained based on the average value every time the vehicle travels the set distance. Then, for obtaining the average value, by shortening the set time or the set distance, the control sensitivity is sensitively changed and set, and by increasing the set time or the set distance, the control sensitivity is It is set to be insensitive.

As a result, when the control sensitivity is set sensitively, the operation control timing of the elevating operation means becomes short, and the elevating control with a small response delay can be performed.

According to the characterizing feature of the sixth invention, there is the following function in addition to the function of the characterizing feature of the first, second, third or fifth invention.

The control sensitivity of the ascent / descent control operation is performed by using the average value of the detection values at the ground height detecting means for each set time or each time the vehicle travels the set distance as it is as the detected ground height data and performing the ascent / descent control. Is set sensitively.

As a result, the ascending / descending control is executed in a state in which the followability is good corresponding to the change in the ground height of the work device.

Then, the average value of the detection values in the ground height detecting means is obtained as the first average value every time the first set time is traveled or each time the vehicle travels the first set distance. Within each of the plurality of first average values obtained within the two set time periods or the time period during which the second set distance is longer than the first set distance, the respective first average values other than the maximum value and the minimum value are excluded. The average value is obtained as the second average value. Then, the control sensitivity of the elevation control operation is set to be insensitive by executing the elevation control using the second average value as the detected ground height data.

As a result, among the detected values obtained at short intervals, the maximum and minimum values are excluded, and the average value is obtained within a long interval, thereby making the control sensitivity of the lifting control operation insensitive. In the state where abnormal data that locally changes is removed as much as possible, smooth elevation control is executed.

According to the characterizing feature of the seventh invention, in addition to the function of the characterizing feature of the first invention, there is the following effect. By setting the operating speed of the actuator to the high speed side, if the ground height of the work equipment fluctuates from the target height, it can be returned to the target height as quickly as possible, and the control sensitivity of the lifting control operation can be changed sensitively. Will be done. Moreover, by lowering the operating speed of the actuator, the lifting operation of the work device by the actuator becomes slow, and as a result, the control sensitivity of the lifting control operation is set to be insensitive.

[0026]

According to the characterizing feature of the first invention, while the work is running, unnecessary lifting operation can be suppressed and smooth lifting control can be executed, but the work is started from the non-work site. Even when the non-working ground has a lot of irregularities, the ground height of the working equipment can be maintained at the target height as much as possible, and the working equipment is in contact with the ground. Thus, it has become possible to provide a lifting control device for a work vehicle capable of preventing the above.

According to the characterizing structure of the second invention, in addition to the effect of the characterizing structure of the first invention, there are the following effects. Even if the work is running, if the ground is uneven and the running speed is slowed down, the lift control sensitivity should be made sensitive to maintain the ground height of the work equipment at the target height as much as possible. Therefore, it is possible to prevent problems such as the working device coming into contact with the ground.

According to the characterizing structure of the third invention, the following effect is obtained in addition to the effect of the characterizing structure of the first or second invention.
Since the control sensitivity of the lifting control operation is changed by changing the detection information amount of the detection value for obtaining the detection ground height of the work device, without changing the detection method of the ground height detection means, The data processing described above can be used, and the control sensitivity can be easily changed and set.

According to the characteristic configuration of the fourth invention, the first and second
Alternatively, there are the following effects in addition to the effects of the characteristic configuration of the third invention. When the average value of a plurality of detection values is obtained, the control parameter is changed by changing the parameter, so that only the change in the number of data is required and the processing can be easily performed.

According to the characterizing structure of the fifth invention, the following effects are obtained in addition to the effects of the characterizing structure of the first, second, third or fourth invention. When the control sensitivity is set sensitively, it is possible to execute the lifting control with a small response delay.

According to the characterizing structure of the sixth invention, the following effects are obtained in addition to the effects of the characterizing structure of the first, second, third, fourth or fifth invention. When the control sensitivity is set sensitively, the lifting control is executed in a state of good followability corresponding to the change in the ground height of the work equipment, and when the control sensitivity is set insensitive, it is as much as possible. , Smooth lifting control is executed.

According to the characterizing structure of the seventh invention, in addition to the effects of the characterizing structure of the first invention, there are the following effects. Since it is not necessary to change the detection height information in the ground height detecting means, and accurate information can always be obtained as the height detection information, there is no fear that the followability of the lifting control with respect to the height variation of the working device is deteriorated. .

[0033]

Embodiments will be described below with reference to the drawings. Figure 7
The front part of the combine as an example of the work vehicle is shown in FIG. This combine is configured to be able to travel by including a pair of left and right crawler traveling devices 1 and 1, and a cutting pretreatment unit as a working device for cutting planted grain culms (an example of planted stem culms) in the front part of the machine body. 2 is provided so as to be able to move up and down, and a rear side is provided with a threshing device 3 for threshing the cut culms, a grain tank 4 for storing the threshed grains, a boarding operation unit 5, and the like.

The pre-cutting processing section 2 includes a weeding tool 6 for allocating and dividing the planted culms of the strip to be cut, a raising device 7 for raising the planted culms in a standing posture, and a plant of the raised culms. Hair clipper type cutting device 8 for cutting the original side, vertical transfer device 9 for transferring the cut grain culm backward while gradually changing its posture to a sideways posture.
Etc., and is pivotally supported so as to be able to move up and down around a horizontal axis with respect to the machine body. Further, the hydraulic cylinder CY as an actuator is configured to be driven up and down by an expansion / contraction operation.

A work for determining whether or not the pre-mowing processing unit 2 is in the mowing work state by detecting whether or not a mowing grain culm is present at the carrying entrance of the vertical carrying device 9. The stock origin sensor S0 which is a state determination means is provided.
Further, an ultrasonic sensor S1 as a ground height detecting means for detecting the ground height is provided at a position on the rear side of the weeding tool 6. This ultrasonic sensor S1 is composed of a transmitter 10 for transmitting ultrasonic waves downward and a receiver 11 for receiving ultrasonic waves reflected on the ground, and the time from transmission to reception It is configured in a non-contact manner so as to detect the height above ground by measuring. To add an explanation,
In determining the reception of ultrasonic waves, it is determined that "reception" is performed on condition that the reception intensity is higher than the set intensity, and the receiver 11 directly transmits from the transmitter 10. For the purpose of avoiding erroneous detection due to reception of waves, the set strength is configured to gradually decrease with the lapse of time after transmission. Therefore, in the present ultrasonic sensor S1, when the reflected object of the ultrasonic wave is distant or extremely close, it is not judged to be received, and the detected data has a large value close to the maximum value.

As shown in FIG. 1, the hydraulic cylinder CY.
Is a single-acting type cylinder, and the hydraulic oil CY supply state is changed to a rising position (ON
State), a neutral stop position (OFF state), and a supply position to the hydraulic device for the others, and a three-position switching type electromagnetic rising control valve V1 is provided.
1 is configured to be switched and controlled by a control device 12 as an elevating control means.

In addition, a pair of drain oil passages L2, L3 branched in parallel from the middle of the pressure oil supply passage L1 for the hydraulic cylinder CY have orifices 13, 13 having different throttle diameters.
14 is provided, and each of the drain oil passages L2 and L3 is provided with two-position switching type open / close lowering control valves V2 and V3.

The boarding operation unit 5 has a mowing height setting device 15 for setting the set height of the mowing pretreatment unit 2 during mowing work.
And an elevating lever 16 for elevating and lowering the pre-mowing processing unit 2 based on manual operation. When the elevating lever 16 is operated from the neutral position to the ascending position, the ascending switch SW1 is turned on and operated to the descending position. Then the lowering switch S
W2 is turned on and each switch SW1, S
The detection state of W2 is input to the control device 12. Further, the detection state of the stock source switch S0 is also input to the control device 12. Although not illustrated, the pre-mowing processing unit 2
There is provided height-to-body detecting means for detecting the height with respect to the body. Further, the traveling drive system for the crawler traveling device 1 is provided with a revolution speed sensor S2 for detecting the revolution speed of the traveling output shaft, and the control device 12 is based on this revolution speed information.
The present traveling speed and traveling distance are calculated. Therefore, the rotation speed sensor S2 constitutes the vehicle speed detecting means of the vehicle body.

The control device 12 automatically turns on and off on the condition that the height of the pre-cutting processing unit 2 is lower than the set height based on the information of the height detecting means for the body. With the ON operation of the switch SW3, the automatic raising / lowering control for controlling the operation of the hydraulic cylinder CY is performed so that the ground height of the pre-mowing processing unit 2 becomes a set value. And at the beginning and end of the mowing work,
Even when the automatic raising / lowering control is executed to raise / lower the reaping pretreatment unit 2 preferentially based on the instruction of the raising / lowering lever 16, if the instruction of the raising / lowering lever 16 is issued, the raising / lowering lever 16
The manual lifting operation based on the command is configured to be executed prior to the automatic lifting control. Incidentally, the raising / lowering operation by the raising / lowering lever 16 is executed by “high speed ascent” or “high speed lowering” described later.

Then, the controller 12 controls the stock sensor S0.
Is in the OFF state (non-working state), and OFF
While the set time (4 seconds) elapses from the time when the switch from the state to the ON state (working state) is detected,
The control sensitivity of the lifting control operation based on the detection information of the ultrasonic sensor S1 is sensitively changed and set, and the set time (4 seconds) starts from the time when it is detected that the stock sensor S0 is switched from the OFF state to the ON state. After the lapse of time, the control sensitivity of the lifting control operation is set to be insensitive.

Further, the plant splitting state discrimination means 100 for discriminating that the ultrasonic sensor S1 is in the plant splitting state in which it has entered the planted culm based on the detection information of the ultrasonic sensor S1 is in a control program format. Equipped with the stock split status determination means 1
00 is configured to control the hydraulic cylinder CY in a state where the normal lift control mode is switched to the stock split control mode when it is determined that the stock split state is set.

Hereinafter, the control operation of the control device 12 will be described in detail with reference to the control flowcharts of FIGS.
If the automatic on / off switch SW3 is turned on and the automatic raising / lowering control is activated, if the stock origin sensor S0 is in the off state, 4 seconds elapse after switching from the off state to the on state even in the on state. If not, the vehicle speed is 0.2
If the speed is less than or equal to meters / second (step 1 to
4) The control sensitivity of the lifting control operation is sensitively changed and set.

That is, the controller 12 controls the ultrasonic sensor S
1, the ultrasonic wave is transmitted every 20 msec, and if the ultrasonic sensor S1 receives the reflected wave, that is, if the measurement is completed, the time from the transmission to the reception is converted into the ground height data. (Steps 5 and 6). If the detected ground height data is 1500 mm or more, it is determined to be an abnormal value, error processing is executed, and if 1500 mm or less, the data is stored in the memory (steps 7-).
9). At this time, if it is abnormal, the counter is incremented.

Thus, the detected ground height data is 1500
If the value is greater than or equal to mm, it is determined to be an abnormal value.
If the measurement distance (distance from the ground) of the ultrasonic sensor S1 is less than or equal to a set value, measurement becomes impossible due to its characteristics.
Although the reflected wave cannot be properly received and the detection distance becomes a large value close to the upper limit value on the contrary, it does not become such a large value during the mowing operation, and is therefore treated as an abnormal value.

Then, every time the past five data are stored, an average value of them is obtained, and the average value is used as the detected ground height data, and the output process for the hydraulic cylinder CY is executed (steps 10 and 11). In this mean value calculation process, if the number of data does not reach 5, the process returns. In this way, the average value of the five detection values is calculated about every 100 msec, and the elevation control is executed sensitively based on this average value.

Then, after the stock origin sensor S0 is switched from the OFF state to the ON state for 4 seconds and the vehicle speed is 0.2 m / sec or more (steps 1 to 4), the elevator is moved up and down. The control sensitivity of the control operation is set to be insensitive. That is, the ultrasonic sensor S1
At 20 msec, an ultrasonic wave is transmitted, and if the ultrasonic sensor S1 receives a reflected wave, the time from the transmission to the reception is converted into ground height data (step 1
2, 13). If the detected ground height data is a value of 1500 mm or more, it is determined to be an abnormal value and error processing is executed. If it is 1500 mm or less, the data is stored in the memory (steps 14 to 16). If there is an abnormality at this time, the counter is incremented.

If the detected ground height data is a value of 1500 mm or more, it is determined that the value is an abnormal value if the distance to be detected by the ultrasonic sensor S1 is smaller than the minimum detectable value. Becomes impossible, and as a result, the detected ground height becomes a very large value, so in such a case,
It is treated as abnormal data.

After that, every time the traveling distance becomes 5 cm, 5
Find the first average value of the data during the cm travel (step 1
7, 18). The number of data n is the maximum number of memory buffers n
_When it becomes ₀ , the process returns to avoid overflow (step 19).

Then, every time the vehicle travels 30 cm, the average value (second average value) of the remaining data excluding the maximum value and the minimum value is obtained from the data obtained every 5 cm travel (step 20). If the second average value H ₂ is larger than the previous second average value data H ₁ by 100 mm or more, it is determined that the data is abnormal data, and the abnormality processing is performed (steps 21 and 22).
When the difference between the second average value H _{2 and the} previous second average value data H ₁ is not larger than 100 mm, the output process is executed with the second average value H ₂ as the detected ground height data (step 23, 24).

Next, the output process will be described. As shown in FIG. 4, a deviation between the ground height data obtained as described above and the target height set by the cutting height setting unit 15 is obtained (step 25), and the deviation falls within the dead zone. For example, based on the magnitude of the deviation, the operating condition of the hydraulic cylinder CY is determined so that the operating speed increases as the deviation increases (steps 26 and 27).

That is, as shown in FIG. 5 and FIG. 6, the descending speed and the ascending speed can be switched in three stages, respectively, depending on the switching condition of the descending control valves V2, V3 based on the magnitude of the deviation. It has become. In FIG. 5, V2 is a descending control valve with a large throttle diameter (small flow rate), and
Reference numeral 3 is a descending control valve having a small throttle diameter (large flow rate). Also, FIG.
Medium (duty) is intermittent ON / OFF of the down control valve
Showing operation. Specifically, in the "low speed descent", the descent control valve V3 is set to 15 msec ON and 40 msec OF.
In the "medium speed descent", the descent control valve V2 is turned on for 35 msec ON and 20 mse.
It is configured to repeat cOFF alternately.

If the operating condition is "high speed rise", if the abnormal value data counted in the steps 8 and 15 is 50% or more during the traveling of the vehicle body for 1 m, the ultrasonic sensor is used. It is determined that S1 is a stock splitting state in which the planted grain culm is plunging, and "1" is set in the flag (steps 28, 29, 30). If the flag is "1", the rising control valve V1 is set to, for example, 0.2.
The hydraulic cylinder CY is operated in a state in which it is intermittently switched to ON for 0.8 seconds and OFF for 0.8 seconds to reduce the rising speed (steps 33, 3).
4).

If the operating condition is other than "high speed increase", or if the ratio of the abnormal data is 20% or less even if it is "high speed increase", it is determined that the stock split condition has been eliminated. Reset the flag to "0",
The hydraulic cylinder CY is operated under the operating conditions determined in step 27 (steps 31, 32, 33, 3).
5). At this time, if the operating condition is “high speed rising”, the rising control valve V1 is kept “ON”, and the rising operation is executed at high speed.

When the hydraulic cylinder CY is actuated in the direction in which the deviation is reduced, even if the deviation falls within the dead zone, it falls within a set width narrower than the dead zone. Until then (see FIGS. 5 and 6), the output operation is continued (step 36). The output start condition is that the deviation exceeds the dead zone once it is within the set width.

As described above, when the stock splitting state is determined, the operating speed of the hydraulic cylinder CY is switched to the low speed side to suppress unnecessary ascending operation, and the ground level of the reaper 2 is set to the target as much as possible. Can be maintained at height.

[Other Embodiments] (1) In the above embodiment, the working state detecting means (share element sensor S0) detects that the working state is switched from the non-working state to the working state for a set time (4 seconds). ) Has passed, the control sensitivity of the lifting control operation is set sensitively, but the lifting control operation is performed during the set distance from the time when it is detected that the non-working state is switched to the working state. The control sensitivity of may be sensitively changed and set. (2) In the above embodiment, the control sensitivity is made sensitive when the traveling speed is equal to or less than the set value, but the control sensitivity becomes insensitive after traveling the set time or the set distance regardless of the traveling speed. It may be set. (3) In the above embodiment, the non-contact type ultrasonic sensor S1 is used as the ground height detecting means, but the present invention is not limited to this, and a ground follow-up type sensor may be used. For example, the configuration may be such that the amount of vertical swing of the grounding body that swings and moves up and down while following the ground contact around the horizontal axis is detected by a potentiometer. (4) In the above-described embodiment, the detection operation of the ground height detecting means is executed at regular time intervals (20 ms) to obtain an average value for each set time, and the control sensitivity is changed by changing the set time. However, the control sensitivity may be set to be insensitive or sensitive by changing the time interval at which the ground height detecting means executes the detection operation. (5) In the above embodiment, the control sensitivity is changed by calculating the detection value information of the ground height detecting means. However, the operating speed of the hydraulic cylinder CY is changed to the high speed side to increase the control sensitivity. The control sensitivity may be sensitively changed and set, and the operating speed of the hydraulic cylinder CY may be changed to a low speed side to insensitively change the control sensitivity.

It should be noted that reference numerals are added to the claims for facilitating the comparison with the drawings, but the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a control block diagram.

[Fig. 2] Control flowchart

FIG. 3 is a control flowchart.

FIG. 4 is a control flowchart.

FIG. 5 is a diagram showing an output processing state.

FIG. 6 is a diagram showing an output processing state with respect to a ground distance.

FIG. 7 is a side view of the front part of the combine.

[Explanation of symbols]

 2 work device 12 control means CY actuator S0 work state detection means S1 ground height detection means S2 vehicle speed detection means

Claims (7)

[Claims] 1. An actuator (CY) for vertically moving a working device (2), a ground height detecting means (S1) for detecting a ground height of the working device (2), and a ground height detecting means ( Based on the detection information of S1),
An elevation control device for a work vehicle, comprising: a control means (12) for controlling the actuator (CY) so that the ground height of the work device (2) becomes a target height. Work state detection means (S0) for detecting whether (2) is in a work state or a non-work state is provided, and the control means (12) is configured such that the work state detection means (S0) is in a non-work state. While detecting, and from the time of detecting the switching from the non-working state to the working state, until the set time elapses or until the set distance travels, the ground height detecting means. The control sensitivity of the lifting control operation based on the detection information of (S1) is sensitively changed and set, and the set time is set from the time when the working state detecting means (S0) detects that the working state is switched to the working state. Or after the setting An elevating control device for a work vehicle configured to change the control sensitivity of the elevating control operation to insensitive after traveling a distance. 2. A vehicle speed detecting means (S2) for detecting the traveling speed of the work vehicle is provided, and the control means (12) is such that the traveling speed detected by the vehicle speed detecting means (S2) is equal to or lower than a set speed. For example, the work state detecting means (S0)
Is configured to sensitively change and set the control sensitivity of the lifting control operation after a set time elapses or after traveling a set distance from the time when it is detected that the switch from the non-working state to the working state. The lifting control device for a work vehicle according to claim 1. 3. The control means (12) is configured to obtain a detected ground height of the working device (2) based on an average value of detection values of the ground height detection means (S1), and The control sensitivity of the elevation control operation is changed to sensitive or insensitive by changing the amount of detection information of the detection value of the ground height detecting means (S1) for obtaining the average value. The lifting control device for a work vehicle according to claim 1 or 2. 4. The ground height detecting means (S1) is configured to intermittently perform a detection operation, and the control means (12) includes a plurality of ground height detecting means (S1). 4. The work vehicle according to claim 1, 2 or 3, wherein when obtaining an average value of detection values, a parameter is changed to change and set the control sensitivity of the lifting control operation to be sensitive or insensitive. Lift control device. 5. The ground height detecting means (S1) is configured to execute a detection operation at every set unit time, and the control means (12) is provided in the ground height detecting means (S1). Based on the average value of the detection value for each set time, or based on the average value every time the vehicle travels a set distance, it is configured to obtain the detected ground height of the working device (2), and for obtaining the average value, The setting time or the setting distance is shortened to sensitively change and set the control sensitivity of the lifting control operation, and the setting time or the setting distance is lengthened to change the control sensitivity of the lifting control operation to be insensitive. The lifting control device for a working vehicle according to claim 1, 2 or 3, wherein 6. The control means (12) obtains an average value of detection values at the ground height detecting means (S1) for each set time or each time the vehicle travels a set distance as a detected ground height, and The elevation control is executed based on the detected ground height, the control sensitivity of the elevation control operation is sensitively changed and set, and the first detection value of the ground height detection means (S1) is set. An average value for each set time or each time the vehicle travels the first set distance is obtained as a first average value, and a plurality of each of the plurality of each of the first set values obtained within the second set time or the time for the second set distance traveled Among the 1 average values, the maximum value and the minimum value are excluded, and the average value of each of the other 1st average values is obtained as the 2nd average value, and by performing the elevation control based on the 2nd average value,
The elevator control device for a work vehicle according to claim 1, 2, 3 or 5, wherein the control sensitivity of the elevator control operation is set to be insensitive. 7. The control means (12) sensitively changes and sets the control sensitivity of the elevation control operation by setting the operation speed of the actuator (CY) to a high speed side, and the operation of the actuator (CY). The elevator control device for a work vehicle according to claim 1, wherein the control sensitivity of the elevator control operation is insensitively changed and set by setting the speed to a low speed side.