JPH09313012A - Control device for tilling height - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for tilling height, capable of lifting and lowering a tiller based on a laser beam and making an operator recognize the attainment of a tiller to a lifting or a lowering limit. SOLUTION: An automatic control system for lifting and lowering a tiller is constituted so as to pass a standard light into a target incidence position at the middle position in the vertical direction of a receiving part S attached to the tiller. When the attainment of the tiller to an upper limit position preset based on a body is detected by the lifting and lowering operation of the system, a restraining means for stopping the control operation of the tiller at a point after the detection and an informing means F for operating an information device so as to make an operator recognize the state are installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilling device that can be raised and lowered with respect to a vehicle body, and is provided with a receiving unit for receiving a reference light beam horizontally transmitted from a transmitting unit installed on the ground. The target position of incidence of the reference ray is set at an intermediate position in the vertical direction with respect to this receiving part, and when the reference ray is incident on the upper side of this incident target position, the tilling device is operated to move upward and below this incident target position. Regarding the improvement of the tilling height control device that performs the control operation of lowering the tilling device when the reference light beam enters the side and stopping the lifting operation of the tilling device when the reference light beam enters this incident target position .

[0002]

2. Description of the Related Art Conventionally, as a tilling height control device constructed as described above, there is one disclosed in JP-A-54-117708. In this conventional example, a vehicle body of a tractor is provided so as to be able to move up and down. A laser that is horizontally transmitted from a transmitting mechanism fixedly installed on the ridge, with a receiving mechanism as a receiving unit via a pillar-shaped member to a machine frame of a tilling rotary (rotary tilling device) as a tilling device. Based on the reception result of the light receiving mechanism, the tilling rotary is moved up and down to keep the working depth constant.

[0003]

Considering the operation at the time of control in the structure of the conventional example, the size of the receiving area in the vertical direction capable of receiving the laser light in the receiving mechanism is limited. For example, when performing work by traveling the car body in a direction descending the inclined surface at the time of work, the tilling device is raised with respect to the car body even if the control of the laser light incident on the incident target position of the receiver is continued. As a result of continued operation, the tiller may rise to the climb limit. In such a case, the subsequent raising control becomes impossible, and the tilling device cannot be maintained at the required height, and there is room for improvement.

Further, as described above, by moving the vehicle body in the direction of descending the inclined surface during the work, the tiller is raised to the upper limit, and after that, the vehicle body is also driven to move upward from the reception area of the receiving mechanism. There is also a case where the laser light falls off and falls out of control. Even in such a case, the height of the tiller cannot be maintained at the required height, and there is room for improvement. Further, as another reason, the laser light may not be emitted from the transmitter due to the voltage drop of the power source in the transmitter, the breakdown of the transmitter, etc. Since it is not possible to receive, the working depth deviates from the target value and there is room for improvement.

In particular, when a trouble occurs in which the laser light cannot be received by the receiving unit, abnormal operation is prevented and at the same time,
It is also useful to promptly let the operator recognize that he is out of control, and an appropriate means is desired.

An object of the present invention is to prevent improper control operation when the tilling device is raised to the limit and when the receiving section cannot receive the reference light beam, and at the same time, it falls into such a state. The reason for this is to reasonably configure the control device that allows the operator to quickly recognize that there is an error.

[0007]

The first feature of the present invention (Claim 1) is, as described at the beginning, a transmitting section installed on the ground for a tiller equipped to be movable up and down with respect to a vehicle body. With a receiving unit for receiving the reference light beam horizontally transmitted from, the incident target position of the reference light beam is set at an intermediate position in the vertical direction with respect to this receiving unit, and the reference light beam is above the incident target position. When it is incident, the tiller is actuated upward, when the reference ray is incident below this target position, the tiller is actuated downward, and when the reference ray is incident at this incident target position, the tiller is actuated. In the tilling height control device that performs a control operation to stop the lifting operation of, when it is detected that the tilling device has reached a preset upper limit position with respect to the vehicle body by the control operation, after this detection time, Tillage equipment Located that it includes a restraining means for stopping the control operation, the action is as follows.

A second feature of the present invention (claim 2) is that the restraining means includes an informing means for detecting this state and activating the informing device when the raising / lowering operation of the tilling device is stopped. And its action is as follows.

As described at the beginning, the third feature of the present invention (claim 3) is that the cultivating device provided to be movable up and down with respect to the vehicle body is horizontally transmitted from the transmitting portion installed on the ground. In addition to having a receiving unit for receiving the reference light beam, the target position of the reference light beam is set at an intermediate position in the vertical direction with respect to this receiving unit, and when the reference light beam is incident on the upper side of the incident target position, it is cultivated. When the reference beam is incident on the lower side of the incident target position, the tiller is lowered, and when the reference beam is incident on the incident target position, the raising and lowering operation of the tiller is stopped. In the tilling height control device that performs a control operation, when it is determined that the receiving portion cannot receive the reference light beam, the control unit of the tilling device is stopped after this determination. To the point Ri, the action is as follows.

A fourth feature of the present invention (claim 4) is that the restraining means includes an informing means for detecting the state when the lifting operation of the tilling device is stopped and operating the informing device. And its action is as follows.

[Operation] According to the first feature described above, when it is detected that the tilling device has risen to the preset upper limit, the restraint means stops the control operation of the tilling device, and thereafter, the tilling device is operated. It does not go up and down.

According to the second feature, when the restraining means stops the control operation of the tilling device, the notifying means operates the notifying device, so that it is necessary to check that the tilling device has reached the preset upper limit. At the same time, the operator is made aware that the lifting and lowering of the tilling device will stop thereafter.

According to the third feature, when the receiving unit determines that the reference light beam cannot be received, the restraint means stops the control operation of the tiller, and thereafter the elevator is moved up and down. Will not be done.

According to the fourth feature, when the restraint means stops the control operation of the tilling device, the notifying means actuates the notifying device, so that the receiving unit cannot receive the reference light beam. At the same time as making the operator recognize, the operator is made aware that the lifting and lowering of the tilling device thereafter will stop.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an engine 4 is mounted on a front portion of a traveling vehicle body 3 having front wheels 1 and rear wheels 2, and a mission case 5 to which power from the engine 4 is transmitted to a rear portion of the traveling vehicle body 3. A steering handle 6 and a driver's seat 7 are provided at the center of the traveling vehicle body 3, and a rotary cultivator 9 is movably connected to the rear end position of the traveling vehicle body 3 via a link mechanism 8 to form an agricultural tractor. .

A pair of left and right lift arms 11 which are lifted and lowered by a lift cylinder 10 arranged on the upper part of the mission case 5 and the link mechanism 8 are connected via a lift rod 12, and the lift cylinder 10 is operated to operate a rotary tiller. 9, a lift arm 11 is provided with a potentiometer-type lift arm sensor 13 for measuring the height of the rotary tiller 9 with respect to the vehicle body from the swing amount of the lift arm 11 at the base end portion of the lift arm 11. A level sensor S as a receiving unit is provided on the upper surface of the cultivating device 9 through a pillar 14.
It has. The rotary tiller 9 includes a large number of plowing claws 9A that are driven to rotate, and a rear cover 9B that grounds the ground after plowing so that it can swing about a lateral axis. Also, a rotary tiller 9 is provided on the side of the driver's seat 7.
A position lever 16 for controlling the elevation of the rotary cultivating device 9 is provided, a compulsory elevating lever 18 for forcibly raising and lowering the rotary cultivating device 9 is provided near the steering handle 6, and a side of the driver's seat 7 is provided with It has a control box 19 for controlling elevation.

As shown in FIGS. 7 and 8, the level sensor S is 4 in plan view with respect to the outer surface of the case 21 in a vertically long posture.
In this position, a large number of light receiving elements 22 are arranged in the vertical direction over 250 mm to have the ability to detect a laser beam L as a reference beam emitted on a horizontal plane.
Since the plurality of light receiving elements 22 are arranged in the vertical direction, the incident position of the laser light L on the level sensor S is recognized with a resolution of 5 mm in the vertical direction, and the detection result is converted into a voltage signal and output. Is configured to. As shown in FIG. 6, the position lever 16 is configured to be swingable around a lateral axis, and a position setter 23 for measuring the swing operation position of the position lever 16 is provided at the base end thereof. The position lever 16 is configured to be freely operable in a position control area PO for vertically moving the rotary tiller 9 with the traveling vehicle body 3 as a reference, and a tilling depth control area DE for performing a tilling depth control based on a laser beam L described later. Has been done.

As shown in FIG. 5, the forced elevating lever 18 is configured to return to the neutral position N by a spring (not shown), and its base end portion U is raised above the neutral position N. Ascending switch 24 for detecting that it has been operated by U
And a lowering switch 25 for detecting that the lowering position D has been operated on the basis of the neutral position N. FIG.
As shown in FIG. 3, the control box 19 is provided with a potentiometer-type tilling depth setting device 27 that is rotated by a dial 26, a setting change lamp 28, an alarm 29, and an alarm lamp 30. Dial 26 for setting the working depth
Is configured to be freely operable in the area between the "shallow" position and the "deep" position, and is mechanically moved to the "standard" position in the center of the setting area by a detent mechanism (not shown) as shown in the figure. It is configured to be held in, and after making artificial setting changes,
"Standard" due to the action of the detent mechanism even when returning
The position can be accurately recognized with the feeling of operation. Further, even when the dial 26 for setting the plowing depth is operated in the entire operation area, the incident target position A described later is 50% of the detection area of the level sensor S (area C of A ′ to A ′ shown in FIG. 9).
The change amount is set to fall within the range.

As shown in FIG. 4, a fuel level meter 33, an engine tachometer 34, a cooling water thermometer 35, and a plurality of lamps indicating a work mode are provided on a meter panel 32 in front of the driver's seat 7. 36, and the working depth control lamp 36A is turned on during the work in which the level sensor S receives the laser light L.

As shown in FIG. 1, a laser lighthouse T is constructed as a device for emitting a laser beam L to be received by the level sensor S. The laser lighthouse T is a tripod 37.
The main body 38 supported by the main body 38 is provided with a light source (not shown) that horizontally emits the beam-shaped laser light L, and the reflecting mirror or prism in the main body 38 is driven by an electric motor (not shown). It is configured to rotate the beam-shaped laser light L from the light emitting source 600 times per minute by rotating the vertical axis Y about 600 (600 rpm) per minute. Further, when the laser light L cannot be emitted to the laser lighthouse T, or when the voltage of the battery as the power source is lowered and the laser light L cannot be emitted, the situation is imminent. A transmitter 39 for transmitting this state to the tractor by radio waves is provided.

Then, when the plowing height in the rotary tiller 9 is set to a required value, the laser light from the laser lighthouse T with respect to the incident target position A set at the vertical center of the level sensor S. By starting the work in a state in which the height of the laser lighthouse T against the field is adjusted so that L is incident, the control device 40 as the tilling height control device provided in the vehicle body 3 causes the laser light L to act as the level sensor S. As a result of raising and lowering the rotary tilling device 9 so as to receive at the incident target position A, it is possible to cultivate a wide field in a horizontal plane with high accuracy.

As shown in FIG. 2, the control device 40 comprises a microprocessor (not shown). For the control device 40, the level sensor S, the working depth setting device 27, and the position are set. An input system of signals from each of the setting device 23, the lift arm sensor 13, the raising switch 24, and the lowering switch 25 is formed, and
Solenoid valve V for controlling the lift cylinder 10, the setting change lamp 28, the alarm 29, the alarm lamp 3
An output system for each 0 is formed (the output system to the meter panel 32 is not shown), and further, an input / output system for the memory 41 and an input from the receiver 42 that receives radio waves from the transmitter 39 of the laser lighthouse T. The system is formed.
Further, as the solenoid valve V, a so-called solenoid proportional type valve that obtains an opening degree corresponding to the supplied electric power value is used.
0 is configured such that the electric power supplied to the solenoid valve V can be adjusted by changing the duty ratio of the intermittent signal supplied to the solenoid valve V (PWM type control).

Next, the elevation control of the rotary tiller 9 by the controller 40 will be described. As shown in the flowchart of FIG. 12, a main lifting control routine is set. In this lifting control routine, a signal from the position setter 23 is first input to determine whether the position lever 16 is in the position control area PO or the plowing depth control area. It is determined whether it is in the DE (steps # 101 and # 102).

That is, by operating the position lever 16 in the position control area PO as shown in FIG. 6, the position control for raising and lowering the rotary tiller 9 to the vehicle height corresponding to the operating position of the position lever 16 is performed. In addition to making it possible, the plowing depth based on the laser beam L is set as described below by setting the plowing depth control region DE formed at the descending side end of the rotary tiller 9 in this position control region PO as described below. It is configured to allow control.

Specifically, when it is determined that the position lever 16 is set in the working depth control area DE, the processes of the forced rising routine, the forced lowering routine, the sampling routine, the check routine, and the working depth control routine are executed. Perform sequentially (# 200, # 300, # 400, # 500, # 6
(00 step) or when the position lever 16 is set in the position control area PO, the processing of the position control routine (# 700 step) is performed.

As shown in the flow chart of FIG. 13, in the forced ascending routine (step # 200), the ascending flag is discriminated, and if the flag is "0", the ascending switch 24
The solenoid valve V is operated to the ascending position only when is turned on, and the ascending operation is continued until it is determined that the rotary tiller 9 has reached the upper limit based on the signal from the lift arm sensor 13, and the ascending operation is performed. When is completed, the solenoid valve V is returned to the neutral position and the rising flag is set to "1" (steps # 201 to # 207). The ascending flag is set to "1" only when the ascending operation is performed in the forced ascending routine, and is otherwise set to "0".

As shown in the flow chart of FIG. 14, in the forced lowering routine (# 300 step), the rising flag is discriminated, and when the flag is "1", the lowering switch 25
When the level sensor S is in the state of sensing the laser beam L only when is turned on, and when it is not in the sensing state, the solenoid valve V is selected based on the initial map data selected based on the stored data. To start the control of. In this control, as shown in the graph of FIG. 11, first, electric power having a duty ratio of 100% is supplied to the solenoid valve V only for the time T1, and the solenoid valve V is supplied.
Is kept open at the lowered position to start the high speed lowering of the rotary tiller 9, and the solenoid valve V
The characteristic is set such that the duty ratio of the intermittent signal for operating is reduced to reduce the opening of the solenoid valve V (operate in the throttle direction) to reduce the descending speed (#
Steps 301 to # 304). Note that the stored data indicates the height of the rotary tiller 9 with respect to the vehicle body when the tilling depth is controlled based on the laser light L, as described later.
The average value is stored in the memory 41. The initial map data is a table of the target opening degree of the solenoid valve V (which has a relationship proportional to the target lowering speed) over time, and the initial map data is a relative value between the rotary tiller 9 at the upper limit position and the ground. Corresponding to the value of the distance, multiple types are set so that the larger the relative distance is, the higher the descending speed becomes, and as described above, one of the multiple types of initial map data is stored based on the stored data. By selecting, the time until the rotary tiller 9 comes into contact with the ground can be maintained substantially constant.

Next, whether the level sensor S is already in a state of detecting the laser beam L when the lowering switch 25 is turned on, or whether the rotary tiller 9 according to the initial map data is used.
When the level sensor S reaches the state of detecting the laser light L when the vehicle is descending, the intermediate map data is selected at this timing (the position of T2 in the graph), and the solenoid valve V is operated based on this data to operate the rotary tiller. The descent control is continued. In addition, the intermediate map data selected reduces the opening degree of the solenoid valve V by reducing the duty ratio of the intermittent signal for operating the solenoid valve V with the lapse of time similarly to the above-mentioned initial map data (operating in the throttle direction). ) To reduce the descending speed, and if the level sensor S is already in the state of sensing the laser beam L when the descending switch 25 is turned on, the signal of the lift arm sensor 13 is detected. Intermediate map data is selected based on the value or the incident position of the laser light L on the level sensor S, and when the level sensor S senses the laser light L when the rotary tiller 9 is descending, the solenoid valve V at that timing is selected. Intermediate map data in which the opening degree and the opening degree of the solenoid valve V at the start of control coincide with each other are selected.

Next, when the rotary tiller 9 is lowered by controlling the solenoid valve V based on the intermediate map data, the tilling depth control by the laser light L described later is performed based on the signal from the level sensor S. And the opening degree (target speed) of the solenoid valve V in the case of assuming that, the opening degree (target speed) of the solenoid valve V controlled based on the intermediate map data is compared,
If the results of this comparison match (the position of T3 in the graph), the solenoid valve V is controlled with the same characteristics as the plowing depth control by the laser light L while the operation of the solenoid valve V to the upside is blocked. (Steps # 305 to # 308).

By this descending control, the rotary tiller 9 descends to a height at which the laser beam L is incident on the target incident position A of the level sensor S, or a predetermined time has elapsed since the descending control was switched to the descending control based on the intermediate map data. At the timing (the position of T4 in the graph) which has passed, the ascending flag is set to "0" and the forced descending routine is ended (# 309, # 310 steps).

The graph shown in FIG. 11 represents the opening degree of the solenoid valve V in the forced lowering routine in the vertical axis direction and the elapsed time in the horizontal axis direction. At the time of control, the target rotary tillage is performed. The descending speed of the device 9 and the opening degree of the solenoid valve V have a direct proportional relationship. Further, as shown in the graph, the process of the descending control from time "0" to time "T3" is called a high-speed descending mode, and the process of the descending control from time "T3" to time "T4" is called the final descending mode. I am calling it.

As shown in the flow chart of FIG. 15, in the sampling routine (# 400 step), the signal from the level sensor S is sent to the controller 40 at a cycle equal to or shorter than the cycle (10 hertz) at which the level sensor S senses the laser beam L.
If it is in the receiving state, the sensing position of the laser beam L detected by the level sensor S is written in the memory 41 to set the receiving flag to "1", and if the level sensor S is not in the receiving state. The reception flag is set to "0". If the reception state continues, the data is updated by overwriting the same address in the memory 41.

As shown in the flow chart of FIG. 16, in the check routine (# 500 step), when the reception flag based on the sampling routine (# 400 step) is "1", the normal reception state continues. Therefore, the signal from the lift arm sensor 13 is input, and the check routine is exited (steps # 501 to # 503) unless the rotary tiller 9 has reached the upper limit, and conversely, the reception flag is "0". If it is, it is not in the receiving state, so it is judged whether the state in which the receiving flag is "0" continues for a set time (a relatively short time set to 1 second or less), and if it does not continue. , It is considered that this is a temporary phenomenon, so exit the check routine (#
504 steps). Even if the reception flag is "1", if it is detected from the signal from the lift arm sensor 13 that the rotary tiller 9 has reached the upper limit, it can be determined that the ascending operation is impossible. Case and
If the reception flag is "0" for the set time (relatively short time set to 1 second or less), it can be determined that there is an abnormal condition. In such a case, the solenoid valve V is neutralized. The lamp 3 which is operated to the position to stop the lifting and lowering operation of the rotary tiller 9, activate the alarm 29, turn on the alarm lamp 30, and show the working mode of the meter panel 32.
The alarm operation of blinking the working depth control lamp 36A by the laser light L of 6 is continued until the release operation is performed (# 5
05- # 507 steps). This release operation is performed by operating the position lever 16 to the upper limit position, or
This is to operate the forcible lifting lever 18 to the raised position "U". When this operation is performed, the restraint is released, the alarm operation is stopped, and the rotary tiller 9 is raised to the upper limit (elevation control. The operation is not detailed).

Further, the cause of the phenomenon that the state in which the reception flag is "0" continues to be in the abnormal state for the set time (short time set to 1 second or less) is that the laser light is emitted from the level sensor S. It is conceivable that the vehicle body 3 is running at a high level or a low level where L cannot be received, or that the cause of the inability to emit the laser light L to the laser lighthouse T side is caused. In such a case, the lifting and lowering operation is not performed, and the lifting and lowering of the rotary tiller 9 is stopped at the timing when this abnormal state is judged, thereby preventing an unexpected lifting and lowering of the rotary tiller 9 and simultaneously performing an alarm operation. It is intended to make the worker recognize that he is in an uncontrollable state. In the case of an abnormality on the side of the laser lighthouse T, the radio signal from the transmitter 39 can also be received at the side of the tractor at the same time. Therefore, although not shown in the flow chart in this case as well, the solenoid valve V is used as described above. By operating to the neutral position, the lifting and lowering operation of the rotary tiller 9 is stopped, the alarm 29 is activated, and the alarm lamp 3
The alarm operation of turning on 0 and blinking the working depth control lamp 36A among the lamps showing the working mode of the meter panel 32 is continued until the cancel operation is performed. The restraint routine comprises the restraint means E of Claims 1 and 2 and the notification means F, and an alarm 29, an alarm lamp 30, and a working depth control lamp 3 are provided.
Each of 6A corresponds to the notification device of claims 2 and 4.

As shown in the flow chart of FIG. 17, in the working depth control routine (# 600 step) by the laser beam L, the signal is input from the working depth setting device 27 only when the rising flag is "0" and the level is set. The incident target position A in the sensor S is set. The incident target position A is set in the vertical direction of the level sensor S when the dial 26 for setting the plowing depth is set at the center position of the setting area, as shown in FIG. The incident target position A is set at the center position of
A dead zone B (having a total width of 10 mm) of 5 mm is formed in each of the upper and lower regions having the same width. Further, when the dial 26 for setting the working depth is operated to the "deep" side, the incident target position A is displaced to the upper side of the level sensor S to deepen the working depth, and the dial 2 for setting the working depth is set.
When 6 is operated to the "shallow" side, the control operation is set so that the incident target position A is displaced to the lower side of the level sensor S to make the working depth shallow (steps # 601 to # 603). Further, even if the incident target position A is changed by operating the dial 26 for setting the working depth, the dead zone B is formed equally on the ascending side and the lower side with the incident target position A as a reference. When the dial 26 for setting the working depth is changed from the center position of the setting area to either side, the setting change lamp 28 is turned on and the operator is asked to set the current target working depth at the start of working. It is possible to recognize that it is different from depth.

Next, the sampling routine (# 40
The sensing value is set based on the data obtained based on (0 step). In this step, when the reception flag is "1", the laser light L is normally received by the level sensor S, so the memory data is set to the sensing value, and even when the reception flag is "0", as described above. When it is determined that it is a temporary phenomenon, based on the memory data,
It is determined whether this memory data is located above or below the center position of the level sensor S,
If it is in the upper position, the laser beam L is not received by the level sensor S, but it can be judged that the laser beam L is temporarily deviated upward from the level sensor S. Therefore, the value at the upper end of the level sensor S is sensed. If the value is set to the lower position and the laser beam L is not received by the level sensor S if it is in the lower position, it can be judged that the laser beam L is temporarily deviated downward from the level sensor S. The value of the copy is set as the sensing value (# 604 step).

That is, in this process, even when the level sensor S does not receive the laser beam L, if the unreceivable state is extremely short, FIG.
As shown in (b) and (c), the laser light L moves upward with respect to the level sensor S in a short time due to, for example, shaking of the vehicle body 3 and exceeds the sensing range of the level sensor S. If it goes out upward, it may be considered that the raising and lowering operation of the rotary tiller 9 cannot follow. Therefore, in such a case, the detected value M at the level sensor S immediately before the reception becomes impossible is stored in the memory 41. It is determined whether the rotary tiller 9 has been controlled to the ascending side or the descending side by reading from (from whether the memory data is at the upper position or the lower position based on the central position of the level sensor S). By determining the sensing position at the end position L ′ on the side where the control is performed in the sensing area of the level sensor S, the control is performed at high speed (the deviation is large as will be described later, so the ascending speed is increased). Max) low The control operation is set so that the laser beam L is not lost by controlling the rising of the tarry tiller 9.

Next, the dead zone B formed on the basis of the incident target position A is compared with the sensing value, and when the sensing value is in the dead zone B, the solenoid valve V is operated to the neutral position and the rotary tiller is operated. When the lifting operation of 9 is stopped and the sensing value is on the rising control side not in the dead zone B, the duty ratio is set in proportion to the deviation value from the incident target position A to the sensing value and the solenoid valve V is moved to the rising position. The larger the deviation, the larger the opening of the solenoid valve V, so that the return operation to the target working depth can be quickly performed by the high speed rise.
If the sensing value is not in the dead zone and is on the descent control side, the duty ratio is set in proportion to the value of the deviation from the incident target position A to the sensing value and the solenoid valve V is operated to the descent position to reduce the deviation. The larger the opening, the larger the opening degree of the solenoid valve V, and the quicker the return operation to the target tillage depth by the high speed rise (steps # 605 to # 612). Furthermore, the value of the lift arm sensor 13 during the elevation control based on the laser beam L is input every 200 msec, and the average of eight input values is stored in the memory 41. (Step # 613).

As shown in the flowchart of FIG. 18, in the position control routine (step # 700), the control target is set based on the signal from the lever sensor 23,
A dead zone is set based on this control target, and then a signal from the lift arm sensor 13 is input for comparison processing (#
701 to # 703 steps). As a result of this comparison processing, when the signal value from the lift arm sensor 13 is in the dead zone, the solenoid valve V is operated to the neutral position, and when the lift arm sensor 13 value is not in the dead zone and is on the rising control side, the control target To the sensing value, set the duty ratio proportional to the value of the deviation from the sensing value to operate the solenoid valve V to the up position, and if the lift arm sensor value is not in the dead zone and is on the down control side, the sensing value from the control target The duty ratio is set in proportion to the value of the deviation up to and the solenoid valve V is operated to the down position (steps # 704 to # 710).

As described above, in this lifting control, the height of the laser light L from the laser lighthouse T is set to a required height in advance, and the position lever 16 is operated to the end on the deepest side at the start of work. The plowing depth control by the laser light L is automatically started at the plowing depth setting dial 2
It is possible to change the working depth by the operation of 6.
Further, when it is desired to raise the rotary cultivating device 9 to the upper limit as in the case where the vehicle body 3 reaches the end of the field during this control, the rotary cultivating device 9 is operated by operating the forced elevating lever 18 to the raising position "U". When the rotary tiller 9 is lowered after the vehicle body 3 has been turned and the cultivation depth control by the laser light L has been temporarily suspended and the vehicle body 3 has been turned up, the forced lift lever 18 is operated to the lowered position "D". Therefore, the plowing depth control by the laser light L is restarted, and by operating the solenoid valve V based on the map data during this descent, the descent does not take time and the shock does not occur at the time of touchdown. It is made possible. Further, as in the case where the vehicle body 3 sways during work, the lifting and lowering operation of the rotary tiller 9 cannot follow the displacement of the level sensor S caused by the vehicle body sway, and the level sensor S cannot temporarily receive the laser light L. Even if it falls into the state, it is possible to receive the laser beam L again by setting the raising / lowering direction of the rotary tiller 9 based on the data of the memory 41 and raising / lowering the rotary tiller 9. On the contrary, when the level difference in the field is so large that the laser light L cannot be received by the level sensor S, or because the laser lighthouse T falls over, the battery of the power source is exhausted, or the like, the laser light L is lost. When it is not possible to receive, the lifting and lowering operation of the rotary tiller 9 is stopped and the alarm is activated.

In particular, according to the present invention, when the rotary tiller 9 is raised to the upper limit during the tilling depth control based on the laser light L, the lifting and lowering operation of the rotary tiller 9 thereafter is stopped and the alarm is activated. The operator can easily grasp the situation and can take appropriate measures such as adjusting the height of the laser lighthouse T. The stopped state of the lifting operation can also be released by the lifting operation by the position lever 16 or the forced lifting lever 18. Further, when the level sensor S temporarily cannot receive the laser light L, the tilling depth control is continued, but when the laser light L is continuously unreceivable, the following operation is performed. Since the lifting and lowering operation of the rotary tiller 9 is stopped and the alarm is activated, the operator can easily grasp the situation and can take appropriate measures such as adjusting the height of the laser lighthouse T.
The stopped state of the lifting operation can also be released by the lifting operation by the position lever 16 or the forced lifting lever 18.

[Other Embodiments] In addition to the above-described embodiments, the present invention can also be configured, for example, with a hard circuit that is a combination of logic gates, comparators, and the like.

[0043]

Therefore, when the tiller is raised to the limit, a control device for preventing an inappropriate control operation is rationally constructed (claim 1), and it is possible to promptly confirm that such a state is encountered. Can be recognized by the operator (Claim 2). In addition, a control device is reasonably configured to prevent an inappropriate control operation when the receiving unit cannot receive the reference light beam (claim 3), and it is possible to promptly work to prevent such a state. It has become possible for the person to recognize it (Claim 4).

[Brief description of drawings]

FIG. 1 is a side view showing the arrangement of a tractor and a laser lighthouse.

FIG. 2 is a block circuit diagram of a control system.

FIG. 3 is a plan view of a control box.

FIG. 4 is a plan view of a meter panel.

[Figure 5] Side view of the forced lift lever

[Fig. 6] Side view of the position lever

FIG. 7 is a perspective view of a level sensor.

FIG. 8 is a sectional view of a level sensor.

FIG. 9 is a schematic diagram showing a sensing area of a level sensor.

10 (a), (b), and (c) are schematic diagrams showing changes in the laser beam incident position on the level sensor.

FIG. 11 is a graph showing changes in the solenoid valve during forced lowering control.

FIG. 12 is a flowchart of a lift control routine.

FIG. 13 is a flowchart of a forced rising routine.

FIG. 14 is a flowchart of a forced lowering routine.

FIG. 15 is a flowchart of a sampling routine.

FIG. 16 is a flowchart of a check routine.

FIG. 17 is a flowchart of a working depth control routine.

FIG. 18 is a flowchart of a position control routine

[Explanation of symbols]

 3 vehicle body 9 tilling device A incident target position E restraint means F notification means L reference ray S receiver section T transmitter section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Yakusaku 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd.

Claims (4)

[Claims] 1. A cultivating device that is vertically movable with respect to a vehicle body, includes a receiving unit that receives a reference light beam horizontally transmitted from a transmitting unit installed on the ground, and a vertical direction with respect to the receiving unit. The target position of incidence of the reference ray is set to the intermediate position in, and when the reference ray is incident on the upper side of the incident target position, the tiller is operated to rise, and the reference ray is incident on the lower side of the incident target position. A tilling height control device that performs a control operation to stop the tilling device when the reference beam is incident on the incident target position, and the tilling height control device that performs the control operation when the reference light beam is incident on the incident target position. A tilling height control device comprising a restraining means for stopping the control operation of the tilling device after the detection of that the device reaches a preset upper limit position with respect to the vehicle body. 2. The tilling height control device according to claim 1, wherein the restraint means includes an informing means for detecting this state and activating the informing device when the raising / lowering operation of the tiller is stopped. 3. A tilling device that is vertically movable with respect to a vehicle body is provided with a receiving unit that receives a reference light beam horizontally transmitted from a transmitting unit installed on the ground, and a vertical direction with respect to the receiving unit. The target position of incidence of the reference ray is set to the intermediate position in, and when the reference ray is incident on the upper side of the incident target position, the tiller is operated to rise, and the reference ray is incident on the lower side of the incident target position. A tilling height control device that performs a control operation of lowering the tilling device when it does, and stopping the raising and lowering operation of the tilling device when a reference light beam is incident on this incident target position, wherein the receiving unit is a reference A tilling height control device having a restraining means for stopping the control operation of the tilling device after it is determined that the light beam cannot be received. 4. The tilling height control device according to claim 3, wherein the restraint means includes an informing means for detecting this state and activating the informing device when the lifting operation of the tilling device is stopped.