JP2000184810A - Ground working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground working machine so designed as to be equipped with a means for altering the rate of actuating a hydraulic cylinder by a specific method so as to ensure a relevant operator to discriminate operational mode, thereby enable steering operability to be improved in turning at a levee edge in a misoperation condition. SOLUTION: This ground working machine which has a hydraulic cylinder functioning to ascendingly/descendingly drive a ground working device mounted on a traveling machine body, a height sensor 14 for detecting the height of the ground working device above the ground, and a solenoid valve V for the hydraulic cylinder, is such one as to be also equipped with a lift control means A functioning to ascendingly/descendingly drive the ground working device through operating the valve V so as to maintain the device at a set height above the ground based on the detection by the sensor 14 and a means 26 functioning to alter the rate of actuating the hydraulic cylinder through changing the duty ratio for pulse drive current with respect to the solenoid valve V.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grounding device which is connected to a rear portion of a traveling body by a driving mechanism so as to be driven up and down by a driving mechanism, and a grounding position where a work clutch is engaged and a lowering position where a work clutch is disengaged. A neutral position where the position is held as it is, and an artificial lifting lever for the ground working device that is operable to be switched to each of a forced ascending position where the ground working device is raised to a predetermined position, and a state where the ground working device is forcibly raised to a predetermined position. The present invention relates to a ground working machine provided with an elevating operation switch that can be switched between a state in which it is lowered and touched down.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned ground working machine, as shown in, for example, Japanese Patent Application No. 4-50157 by the present applicant, the artificial lifting lever is operated to a "working position" or a "down position". Only when it is, there is a structure that allows the lifting operation by the lifting operation switch, in this case, for example, after turning off the main switch, when the artificial lifting lever is restarted the `` work position '' or If it is set to the "lower position", there is a risk that the raising and lowering operation by the raising and lowering operation switch may be performed at the same time as the starting operation, so when performing such a starting operation, once the artificial raising and lowering lever is once turned to the "neutral position" Then, safety measures were taken so that the raising / lowering operation by the raising / lowering operation switch was permitted.

[0003]

The above-described lifting and lowering operation structure is different from the conventional lifting and lowering operation structure by the swinging operation of the lifting and lowering lever, in which the traveling speed of the airframe is reduced when turning on a ridge in a field. In addition to the low-speed switching operation and the handle rotation operation, the lifting lever operation must be performed within a short time, and there is a drawback that the work load on the operator is large, so in addition to the lifting operation by swinging the lifting lever, ,
The lifting and lowering operation of the working device at the time of the turn on the ridge can be performed by a switch operation that is easy to perform. However, as described above, it is necessary to return the artificial elevating lever to the `` neutral position '' once in order to avoid an unexpected elevating operation of the working device accompanying turning on and off of the main switch, and there is still troublesome operation. There was room for improvement. An object of the present invention is to eliminate the above disadvantages.

[0004]

According to a feature of the present invention, in the ground working machine described at the beginning, the artificial lifting lever is configured to be operable to another operation position different from each of the operation positions. The present invention is characterized in that a mode switching means is provided for setting a control mode in which the raising / lowering operation by the raising / lowering operation switch is permitted only when operated to the operation position.

[0005]

[Action] By switching the artificial lifting lever to the “planting”, “down”, “neutral”, and “up” operating positions, a predetermined operating state can be realized in a swing operation type operation mode. Thus, a manual operation without an operation error becomes possible. Also, in the case of work such as turning around a ridge during ground work traveling in the field,
In order to reduce the maneuvering operation, by setting the artificial elevating lever to the other operation position, always operate the elevating operation switch in the operation mode regardless of the on / off operation of the main switch. By doing so, the lifting and lowering operation of the ground working device becomes possible.

[0006]

Accordingly, by switching between a manual operation state by manual switching by an artificial lifting lever and an automatic operation state by switch operation by a lifting and lowering operation switch based on the intention of the pilot, the operation mode by the pilot can be determined. Can be performed reliably, and it is possible to improve the maneuverability when turning around a ridge with few operation errors.

[0007]

Embodiments will be described below with reference to the drawings. FIG.
2 shows a riding rice transplanter which is an example of a ground work machine.
This rice transplanter is configured such that a seedling planting device 3 [an example of a ground working device] can be driven up and down by a lift cylinder 4 [an example of a driving mechanism] and a front-rear shaft via a link mechanism 2 at a rear portion of a riding type traveling machine body 1. It is configured so that it can be rolled freely around the core so that seedlings can be planted on the mud surface while the aircraft is running. An engine 5 is mounted on a front portion of the traveling body 1, and the power of the engine 5 is transmitted to front and rear wheels 8 and 9 via a belt-type continuously variable transmission 6 and a transmission case 7. The transmission system is configured such that an output synchronized with the vehicle speed is transmitted to the seedling planting device 3 via the planting clutch 11 (an example of a work clutch) that is turned on and off. The seedling placement device 3 includes a seedling rest 12 and a seedling rest 1 that reciprocate and move laterally in a horizontal direction at a constant stroke.
2, a planting mechanism 13 for taking out seedlings one by one from a lower end and planting the seedlings in a field, a plurality of grounding floats 14 for performing a leveling action while following a grounding on a mud surface, and a right and left side of the seedling planting device 3. It is provided with a drawable marker 15 and the like which can be moved back and forth to draw a running index line in the unplanted area in accordance with the planting work. The wire marker is automatically stored in conjunction with the raising operation of the seedling planting device 3. In a retracted state, it is configured to be automatically held by a lock mechanism (not shown), and as shown in FIG. 1, is used for a vertical operation of a marker operation lever 17 which is swingably operated below the steering handle 16. Accordingly, the two-point switchable marker switch 18 is operated, and the locked state of the lock mechanism is selectively released by the electromagnetic solenoid SL. Came marker 15 are configured to switch to the working attitude. The marker switch 18 is urged to return to the neutral state, and based on an operation in any direction, energizes the corresponding electromagnetic solenoid SL for a certain period of time to perform an unlock operation. The raising and lowering operation of the seedling planting device 3 is configured to be manually operable based on the operation of a forward / backward swing operation type artificial lifting / lowering lever 20 disposed on the side of the driver's seat 19 of the aircraft operation unit. The amount of forward / backward operation of the artificial lifting / lowering lever 20 is detected by a potentiometer-type lever sensor 21, and the output thereof is discriminated by a control device 22 equipped with a microcomputer for each set level so that an operation state corresponding to each operation position is obtained. The switching control of the electromagnetic hydraulic control valve V for the lift cylinder 4 is performed. That is, when the elevating lever 20 is operated to the “elevated position”, the seedling planting device 3 is forcibly elevated to the maximum position. still,
At this time, the link mechanism 2 detects that the seedling planting device 3 has risen to the maximum ascending position by contacting the upper limit switch SW2 attached to the rear wheel fender 23. When operated to the "neutral position", the seedling planting device 3 holds the current level, and when operated to the "down position", the seedling planting device 3 descends until it touches the mud surface. Also, `` planting position ''
To lower the seedling planting device 3 to the ground,
The electric motor 10 is driven so that the planting clutch 11 is engaged, and the planting operation state is set. In addition, a swing lever type raising / lowering operation switch SW1 is provided below the steering handle 16, and a state in which the seedling planting device 3 is forcibly raised to the maximum raising position and a state in which the seedling lowering contact is lowered based on the operation of the switch SW1. It is configured to be switchable between and. An automatic lifting / lowering control means A for controlling the driving of the lift cylinder 4 is provided so that the seedling planting depth, that is, the height of the seedling planting device 3 against the mud surface is always kept constant. That is, the grounding float 1 located at the center in the left and right direction among the grounding floats 14 provided vertically swingably around the rear horizontal axis X.
A potentiometer type float sensor 2 for detecting the amount of vertical swing caused by a change in ground height is provided above the front side of the sensor 4.
The control device 22 controls the switching of the electromagnetic hydraulic control valve V of the lift cylinder 4 so that the detection value of the float sensor 24 matches the set value of the potentiometer type sensitivity adjuster 25. It should be noted that this automatic raising / lowering control operates only when the raising / lowering lever 20 is set to the “planting position” or the “lowering position”. There is provided a changeover switch 26 for changing the elevating speed of the lift cylinder 4 in the elevating control operation according to the work situation. When the switch 26 is switched to “2”, the lift cylinder 4
Is set to a standard value, and when it is switched to "1", the ascending speed becomes faster than the standard value and the descending speed becomes slower than the standard value. When switching to "3", the ascending speed becomes slower than the standard value, and the descending speed becomes faster than the standard value. In the normal operation, the position is set to the “2” position, and when an additional work machine such as a medicine spraying device is added and the work device weight is heavy, the position is set to the “1” position. When the headland should be strongly leveled, the position is switched to the "3" position. This change of the elevating speed is performed by appropriately changing and controlling the duty ratio of the pulse drive current to the electromagnetic control valve V.

The lifting lever 20 is configured to be operable to another "automatic position" different from each of the operation positions, and the lifting operation by the lifting / lowering operation switch SW1 is performed only when the lever is operated to the "automatic position". A mode switching means B for setting an allowable control mode is provided. More specifically, as shown in FIG. 4, the operation path of the series of lifting levers 20 for each of the operation positions is operated from the “neutral position” to the “automatic position” via a path extending laterally outward. The switching to the “automatic position” is similarly determined by the control device 22 by zone determination of the detection value of the lever sensor 21. That is,
The mode switching means B is provided in the control device 22 in the form of a control program, and the control device 22 executes control as follows.

As shown in FIGS. 2 and 3, when the control is started, the detected value of the lever sensor 21 is discriminated as a zone, and it is determined whether or not the automatic position is operated [Step 1]. If it is set, the raising / lowering operation switch SW1 is operated, and if the seedling planting device 3 is not at the upper limit position, it is moved up to reach the upper limit position, and if it is at the upper limit position, it is determined from the detection information of the float sensor 24. Ground float 14
The seedling planting device 3 is moved down until it touches the ground [steps 2 to 8]. If the marker switch 18 is operated when the seedling planting device 3 is lowered, the electric motor 10 is driven to turn on the planting clutch 11, and the mode is shifted to the automatic elevating control mode (steps 9 to 11). If the elevating lever 20 is set to the "automatic position", the above control steps are repeated, and the elevating operation by the elevating operation switch SW1 becomes possible. Next, if the elevating lever 20 is not in the "automatic position", the operating state is operated based on the functions of "neutral position", "elevating position", "down position", and "planting position". ”, The operation to enter the planting clutch 11 is possible in conjunction with the operation of the marker switch 18, and the“ down position ”,
At each of the “planting positions”, the seedling planting device 3 descends on the ground, and is set to the automatic raising and lowering control mode (steps 12 to 27).
If the changeover switch 26 is set to the position "3" in the state where the switch 26 is operated to the "down position", the leveling by pressing with the ground float 14 on the headland can be performed. Step 1 constitutes the mode switching means B.

[0010] In the claims, reference numerals are provided to facilitate comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a control block diagram.

FIG. 2 is a control flowchart.

FIG. 3 is a control flowchart.

FIG. 4 is an operation path diagram of a lifting lever.

FIG. 5 is a side view of the rice transplanter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling body 3 Ground working device 4 Drive mechanism 11 Work clutch 20 Artificial elevating lever B Mode switching means SW1 Elevating operation switch

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[Procedure amendment]

[Submission date] March 7, 2000 (200.3.7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Ground work machine

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction for raising and lowering a ground working device in a ground working machine.

[0002]

2. Description of the Related Art In a ground work machine, a hydraulic cylinder for vertically moving a ground work device provided in a traveling machine body, a height sensor for detecting a height from the ground to the ground work device, and an electromagnetic control valve for the hydraulic cylinder Based on the detection of the height sensor, the control valve is operated to operate the hydraulic cylinder so that the ground work device is maintained at the set height from the ground, and the ground work device is driven up and down It is configured to be.

[0003]

SUMMARY OF THE INVENTION In a riding type rice transplanter which is an example of a ground working machine, a seedling planting apparatus is maintained at a set height from a rice field based on detection of a height sensor.
When the seedling planting device is driven up and down, the water on the surface of the rice field is low, such as when there is little water and mud clumps are scattered and there are relatively many irregularities. There are various states. The present invention relates to a ground work machine, wherein a ground work device is driven up and down by a hydraulic cylinder so as to be maintained at a set height from the ground based on a height sensor detecting a height from the ground to the ground work device. It is an object of the present invention to make it possible to drive the ground working device up and down in accordance with various states of the ground when configured as described above.

[0004]

A feature of the present invention resides in that a ground working machine is configured as follows. [1] A hydraulic cylinder for raising and lowering a ground working device provided on a traveling machine body, a height sensor for detecting a height from the ground to the ground working device, and an electromagnetic control valve for the hydraulic cylinder are provided. A lift control means for operating the control valve to drive the ground work device up and down so that the ground work device is maintained at a set height from the ground based on the detection of the sensor, and a pulse drive for the control valve is provided. There is provided changing means for changing the duty ratio of the current to change the operating speed of the hydraulic cylinder.

[2] In the configuration of the preceding paragraph [1], a first state in which the operating speed on the ascending side of the hydraulic cylinder is set to a high speed and the operating speed on the descending side of the hydraulic cylinder is set to a slow speed, and a hydraulic cylinder And a second state in which the operating speed on the ascending side of the hydraulic cylinder is set to be slow and the operating speed on the descending side of the hydraulic cylinder is set to be fast.

[0006]

[I] A hydraulic cylinder for raising and lowering a ground working device provided on a traveling machine body, a height sensor for detecting a height from the ground to the ground working device, and an electromagnetic control valve for the hydraulic cylinder are provided. Based on the detection of the sensor
According to a feature of the present invention, in the case where there is provided a lifting control means for operating the control valve so that the ground work device is maintained at a set height from the ground and driving the ground work device up and down, the pulse drive for the control valve is provided. The time during which the control valve is operated at the current duty ratio (the supply position where hydraulic fluid is supplied to the hydraulic cylinder (the oil discharge position where hydraulic oil is discharged from the hydraulic cylinder)) and the time during which the control valve is operated at the shut-off position ) To change the operating speed of the hydraulic cylinder.

When a pulse drive current is applied to the control valve at a predetermined duty ratio as in the first aspect, a supply position for supplying hydraulic oil to the hydraulic cylinder (an oil discharge position for discharging hydraulic oil from the hydraulic cylinder) ) And the shut-off position, the control valve is operated alternately and repeatedly at high speed. When the control valve is alternately operated at a high speed alternately between the supply position (oil discharge position) and the shutoff position in this manner, the hydraulic oil intermittently becomes a predetermined amount (the control valve is set at the supply position (drain position) when viewed microscopically). It seems that oil is supplied (discharged) by an amount corresponding to the operation time of the oil supply), but from a macro perspective, the operating oil is continuously supplied (discharged).

Therefore, according to the first aspect of the present invention, by changing the duty ratio of the pulse drive current to the control valve, the supply amount of hydraulic oil to the hydraulic cylinder per unit time (unit of hydraulic oil from the hydraulic cylinder) The operating speed of the hydraulic cylinder can be changed by changing the amount of oil discharged per hour (for example, the duty ratio is set such that the proportion of time during which the control valve is operated to the supply position (oil discharge position) increases. When the ratio is changed, the supply amount of hydraulic oil to the hydraulic cylinder per unit time (the amount of hydraulic oil discharged from the hydraulic cylinder per unit time) increases, and the operating speed of the hydraulic cylinder increases When the duty ratio is changed to the side where the ratio of the time during which the control valve is operated to the supply position (oil discharge position) becomes smaller, the unit time of the hydraulic oil to the hydraulic cylinder is reduced. Rino supply amount (oil discharge amount per unit of time the hydraulic fluid from the hydraulic cylinder) is low, the operating speed of the hydraulic cylinder is changed to the low speed side).

[II] When the operating speed of the hydraulic cylinder can be changed as described in the first aspect (see the latter half of the preceding item [I]), according to the state of the ground on which the ground work machine travels, The operating speed of the hydraulic cylinder (elevation speed of the ground work device) can be set to an appropriate speed.

Further, since the duty ratio of the pulse drive current to the control valve can be easily changed by an electric process or software as in the first aspect of the present invention, the hydraulic pressure can be changed by using a flow control valve or the like. The operation speed of the hydraulic cylinder can be easily changed as compared with a configuration in which the supply amount of hydraulic oil to the cylinder per unit time (the amount of hydraulic oil discharged from the hydraulic cylinder per unit time) is changed.

[III] According to the feature of the second aspect, similar to the case of the first aspect, the "action" described in the above [I] and [II] is provided, and in addition to this, the following "action" is provided. "
It has. According to the features of the second aspect, the first state in which the operating speed of the hydraulic cylinder on the ascending side is set to be high and the operating speed of the hydraulic cylinder on the descending side is set to be slow, and the operating speed of the hydraulic cylinder on the ascending side Is set to be slow, and the second state in which the operating speed on the descending side of the hydraulic cylinder is set to be fast can be made to appear by the changing means.

In a riding type rice transplanter, which is an example of a ground working machine, when a separate planting machine such as a chemical spraying device is added to increase the weight of the seedling planting device, or the mud on the rice field becomes extremely If it is soft, the first state may be set. In this way, by setting the operating speed of the hydraulic cylinder on the ascending side to a high speed and setting the operating speed of the hydraulic cylinder on the descending side to a low speed in the first state, the ground float provided in the seedling planting device is set. Can be prevented, and stable seedling planting work can be performed.

Conversely, for example, when there is little water and mud clumps are scattered and there are relatively many irregularities, or when turning on a ridge (headland), the land surface is pressed by a ground float to level the ground, The second state may be set. By setting the operating speed on the rising side of the hydraulic cylinder to a low speed and setting the operating speed on the descending side of the hydraulic cylinder to a high speed in the second state in this way, the grounding float tends to be pressed against the rice field surface. Then, the field surface is pressed by the grounding float and leveled.

[0014]

According to the first aspect of the present invention, in the ground working machine, based on the detection of the height from the ground to the ground working device by the height sensor, the ground working machine is maintained at the set height from the ground. When the working device is configured to be driven up and down by a hydraulic cylinder, by changing the duty ratio of the pulse drive current to the control valve, the operating speed of the hydraulic cylinder (ground speed) is changed according to the state of the ground on which the ground work machine travels. As a result, the working performance of the ground working machine can be improved. According to the first aspect of the present invention, changing the duty ratio of the pulse drive current to the control valve can be easily performed by electrical processing or software, so that the changing means for changing the operating speed of the hydraulic cylinder is simplified. This has made it possible to simplify the structure.

According to the feature of claim 2, the "effect of the invention" of the above-mentioned claim 1 is provided similarly to the case of the claim 1. In addition to the "effect of the invention", the following "invention" is provided. Of the effect. According to the features of the second aspect, the first state in which the operating speed of the hydraulic cylinder on the ascending side is set to be high and the operating speed of the hydraulic cylinder on the descending side is set to be slow, and the operating speed of the hydraulic cylinder on the ascending side Is set to a low speed, and a second state in which the operating speed on the descending side of the hydraulic cylinder is set to a high speed can be appeared, so that the ground work machine can further cope with various states, The work performance of the work machine could be further improved.

[0016]

Embodiments will be described below with reference to the drawings. FIG.
2 shows a riding rice transplanter which is an example of a ground work machine.
The riding type rice transplanter is connected to a rear portion of the riding type traveling machine body 1 via a link mechanism 2 so that the seedling planting device 3 can be driven up and down by a lift cylinder 4 and can be freely rolled around a longitudinal axis. It is configured to plant seedlings on the rice field while running the machine body 1. An engine 5 is mounted on a front portion of the traveling body 1, and the power of the engine 5 is transmitted to a front wheel 8 and a rear wheel 9 via a belt-type continuously variable transmission 6 and a transmission case 7. , Planting clutch 11 operated by electric motor 10
The transmission system is configured such that power synchronized with the vehicle speed is transmitted to the seedling planting device 3 via the.

As shown in FIG. 5, the seedling placement device 3 comprises a seedling rest 12, which reciprocates sideways with a constant stroke in the horizontal direction.
A planting mechanism 13 for taking out seedlings one by one from the lower end of the seedling rest 12 and planting them on a rice field, a plurality of grounding floats 14 for leveling while following the grounding on the rice field, and a right and left side of the seedling planting device 3 are provided. It is provided with a drawable marker 15 and the like that can be moved back and forth to draw a travel index line in an unplanted area with the planting operation.

The drawing marker 15 is linked with a wire so as to be automatically stored in conjunction with the raising drive of the seedling planting apparatus 3, and is automatically held in a storage position by a lock mechanism (not shown). It is configured as follows. As shown in FIG. 1, a two-point switch type marker switch 18 is operated in accordance with an up and down operation of a marker operation lever 17, which is disposed below the steering handle 16 so as to swing freely. The locked state of the lock mechanism is selectively released by the solenoid SL, and the drawing marker 15 on the desired side is switched to the operating position with the downward drive of the seedling planting device 3. . Marker switch 18
Is energized to return to the neutral state, and based on an operation in any direction, the corresponding electromagnetic solenoid SL is energized for a certain period of time to perform an unlocking operation.

As shown in FIG. 1, the raising and lowering drive of the seedling planting apparatus 3 is performed manually based on the operation of an artificial rocking lever 20 of a back-and-forth swing operation type arranged on the side of the driver's seat 19 of the body control section. It is configured to be operable. Artificial lifting lever 2
0 operation position is a potentiometer type lever sensor 21
The control device 22 including the microcomputer determines the detection value of the lever sensor 21 for each set level in a zone, and sets the lift cylinder so as to be in the operating state corresponding to each operation position of the artificial lifting lever 20. The electromagnetic hydraulic control valve V for 4 is operated.

As shown in FIGS. 1 and 4, when the artificial lifting lever 20 is operated to the raised position, the seedling planting device 3 is forcibly driven to be raised to the maximum raised position. The detection that the seedling planting device 3 has risen to the maximum ascending position is detected by the rear wheel fender 2.
3 is configured so that the link mechanism 2 comes into contact with the upper limit switch SW2 attached to the upper limit switch SW2. When the artificial raising / lowering lever 20 is operated to the neutral position, the seedling planting device 3 is maintained at the current level, and when the artificial raising / lowering lever 20 is operated to the lowering position, the seedling planting device 3 is driven down until it touches the rice field. When the artificial raising / lowering lever 20 is operated to the planting position, the seedling planting device 3 is driven to descend until it touches the rice field, and the planting clutch 11 is engaged by the electric motor 10 to be in a planting operation state.

As shown in FIG. 1, a swing lever type lifting operation switch SW 1 is provided below the steering handle 16.
The ascending state in which the seedling planting device 3 is forcibly driven up to the maximum ascending position based on the operation of the elevating operation switch SW1, and the descending position in which the seedling planting device is driven down until it touches the rice field surface. The state is configured to take place.

As shown in FIG. 1, the planting depth of the seedlings (the height of the seedling planting device 3 relative to the rice field) is always kept constant.
Elevation control means A for controlling the drive of the lift cylinder 4 is provided. Of the grounding floats 14 supported so as to be able to swing up and down around the horizontal axis X at the rear, the amount of up and down swing caused by a change in the height of the paddle surface is located above the front side of the grounding float 14 located at the left and right center. Is provided by the control device 22 so that the detection value of the float sensor 24 coincides with the set value of the potentiometer type sensitivity adjuster 25.
Is operated. The above elevating control operates only when the artificial elevating lever 20 is operated to the planting position and the descending position.

The lift cylinder 4 in the above-described elevation control
Is provided with a changeover switch 26 for changing the ascending / descending speed according to the work situation. When the changeover switch 26 is operated to “2”, the elevating speed of the lift cylinder 4 is set to a standard value. When the changeover switch 26 is operated to “1”, the ascent speed of the lift cylinder 4 becomes faster than the standard value. Then, the lowering speed of the lift cylinder 4 becomes slower than the standard value. When the changeover switch 26 is operated to “3”, the lifting speed of the lift cylinder 4 becomes slower than the standard value, and the lowering speed of the lift cylinder 4 becomes faster than the standard value.

Thus, in normal work, the changeover switch 26 is operated to "2", and an additional work machine such as a chemical spraying device (not shown) is added to increase the weight of the seedling planting device 3. In this case, the changeover switch 26 is operated to “1”. If you want to level the headland strongly, the changeover switch 26
To "3". Such a change in the lifting speed of the lift cylinder 4 is performed by changing and controlling the duty ratio of the pulse drive current to the hydraulic control valve V.

The artificial lifting lever 20 is configured to be operable to another automatic position different from each operation position, and the lifting operation by the lifting operation switch SW1 is performed only when the artificial lifting lever 20 is operated to the automatic position. And a mode switching means B for setting a control mode in which the descending operation is allowed. As shown in FIG. 4, of the operation paths for the respective operation positions of the series of artificial lifting levers 20,
The artificial elevating lever 20 is configured to be operable to the automatic position via an operation path extending laterally outward from the neutral position, and the operation of the artificial elevating lever 20 to the automatic position is similarly performed. The control unit 22 is configured to make a determination based on the zone determination of the detected value 21.
The mode switching means B is provided in the control device 22 in the form of a control program, and the control device 22 executes control as follows.

As shown in FIGS. 2 and 3, when the control is started, the detection value of the lever sensor 21 is discriminated as a zone.
It is determined whether or not the artificial lifting lever 20 has been operated to the automatic position (step # 1). Artificial lifting lever 20
Is operated to the automatic position, the lifting operation switch S
In accordance with the operation of W1, if the seedling planting device 3 is not at the maximum ascent position, the seedling planting device 3 is driven to move up to the maximum ascent position. The seedling planting apparatus 3 is driven to descend until the ground float 14 comes into contact with the rice field, as determined by the value detected by the sensor 24 (steps # 2 to # 8). If the marker switch 18 is operated when the seedling planting device 3 is driven downward, the planting clutch 11 is turned on by the electric motor 10 and operated.
The operation shifts to the automatic elevating control mode (steps # 9 to # 11).
When the artificial lifting lever 20 is operated to the automatic position, the above control steps are repeated, and the raising operation and the lowering operation by operating the lifting operation switch SW1 become possible.

Next, if the artificial lifting lever 20 is not operated to the automatic position, the operating state is based on the functions of the neutral position, the raising position, the lowering position, and the planting position. When the artificial raising / lowering lever 20 is operated to the planting position, the setting operation of the planting clutch 11 can be performed by operating the marker switch 18. When the artificial raising / lowering lever 20 is operated to the lowering position and the planting position, the seedling The planting apparatus 3 is driven down until it touches the rice field, and the automatic lifting control mode is set (steps # 12 to # 27). If the changeover switch 26 is operated to “3” in a state where the artificial lifting lever 20 is operated to the lowering position, the pressing and leveling by the grounding float 14 on the headland can be performed. The mode switching means B is constituted by the above step # 1.

In the claims, the reference numerals are used to facilitate comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control system.

FIG. 2 is a diagram showing a flowchart of a raising drive and a lowering drive of a seedling planting device by a raising / lowering operation switch in a state where an artificial lifting / lowering lever is operated to an automatic position.

FIG. 3 is a flowchart showing a state in which an artificial lifting lever is operated to an ascending position, a neutral position, a descending position, and a planting position.

FIG. 4 is a diagram showing an operation path of an artificial lifting lever.

FIG. 5 is an overall side view of a riding rice transplanter.

[Description of Signs] 1 Traveling Airframe 3 Ground Working Device 4 Hydraulic Cylinder 14 Height Sensor 26 Changing Means A Elevation Control Means V Control Valve

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (2)

[Claims] 1. A hydraulic cylinder (4) for lifting and lowering a ground working device (3) provided on a traveling body (1), and a height sensor for detecting a height from the ground to the ground working device (3). (14) and an electromagnetic control valve (V) for the hydraulic cylinder (4), and the ground working device (3) is set at a set height from the ground based on the detection of the height sensor (14). And lifting control means (A) for operating the control valve (V) to drive the ground working device (3) up and down so as to maintain the control valve (V), and a pulse drive current for the control valve (V). A ground working machine comprising changing means (26) for changing an operating speed of the hydraulic cylinder (4) by changing a duty ratio. 2. A first state in which the operating speed of the hydraulic cylinder (4) on the ascending side is set to a high speed and the operating speed of the hydraulic cylinder (4) on the descending side is set to a slow speed, and the hydraulic cylinder (4). The change means (26) is set so that a second state in which the operating speed on the ascending side of (4) is set to a slower one and the operating speed on the descending side of the hydraulic cylinder (4) is set to a faster one can appear. The ground work machine according to claim 1, wherein the ground work machine is configured.