JP2000083423A - Working machine for paddy field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rationally constitute a rice transplanter capable of accurately carrying out a steering operation by simplifying an operation for rotating a machine body on a butt. SOLUTION: This rice transplanter is equipped with a forced lifting and lowering lever 26 for disengaging a planting clutch C by an operation to an ascending position to raise a seedling planting apparatus to the upper limit, dropping the seedling planting apparatus to a ground level while maintaining the disengaged state of the planting clutch C by an operation to a descending position and carrying out the operation to the descending position again in the ground state so as to perform the engaging operation of the planting clutch C and with a control apparatus 38 for controlling the seedling planting apparatus so as to drop to the ground level by the returning operation of a steering wheel to the direct advance direction after the rotation of the machine body and, after the dropping, carrying out the engaging operation of the planting clutch C by operating the forced lifting/lowering lever 26 in the descending position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a working device which can be driven up and down with respect to a traveling machine body, and a clutch which is switchable between a state of transmitting power to the working device and a state of shutting off the power. A forced lifting operation tool that is held at a neutral position during operation and that can be freely switched between an ascending position and a descending position based on the neutral position is provided. The working device is raised to a level away from the field scene with the disengagement operation, and the working device is lowered to the field scene while maintaining the disengaged state of the clutch by operating the forcible lifting / lowering operating tool to the lowered position. The present invention relates to an improvement of a paddy working machine including a control device for performing an operation of engaging the clutch by operating a forcible lifting / lowering operation tool to the lowered position again after the descent.

[0002]

2. Description of the Related Art Conventionally, there is a paddy field working machine configured as described above as disclosed in Japanese Patent Application Laid-Open No. 9-23, and in this conventional example, raising and lowering of a working device such as a seedling planting device, and the like. A switching lever (forcible lifting / lowering operation tool) for performing a clutch engagement operation is arranged near the steering handle.

[0003]

Taking a rice transplanting machine as an example, if the machine reaches a headland during operation, after raising the seedling planting device, the machine is operated by a steering operation (steering operation). When the turning of the fuselage is completed, the seedling planting device is lowered, and the planting clutch is set at the timing when the seedling planting device reaches a predetermined position while performing alignment by steering operation. , And an inexperienced operator also performs an operation to reduce the traveling speed when the body turns. For this reason, a plurality of types of operations must be performed in a short time when the body turns on the headland, and the operations are complicated. Therefore, as in the conventional example, the switching lever is disposed in the vicinity of the steering handle so that the raising and lowering of the seedling planting apparatus and the operation of engaging the clutch can be easily performed without almost releasing the hand from the steering handle. However, there is a need to accurately operate the steering handle so as not to disturb the planted row of seedlings at the time of turning the body, and it is desired to further reduce the types of operations performed by the operator.

[0004] An object of the present invention is to rationally construct a paddy working machine capable of accurately performing a steering operation by simplifying an operation for turning on a headland.

[0005]

According to a first feature of the present invention, as described at the outset, a working device is provided so as to be able to drive up and down with respect to a traveling machine body, and power is supplied to the working device. Equipped with a clutch that can be switched between a transmitting state and a state in which power is shut off, is held at a neutral position when not operated, and has a forced lifting / lowering operating tool that can be switched between an ascending position and a descending position based on this neutral position. By operating the forced lifting operation tool to the ascending position, the working device is raised to a level away from the field scene with the clutch disengagement operation, and the forced lifting operation tool is operated to the lowered position by operating the forced lifting operation tool to the lowered position. A control device is provided for lowering the working device to the field scene while maintaining the clutch disengaged state, and after this lowering, operating the forcible raising / lowering operating tool to the lowering position again to perform the engagement operation of the clutch. In the paddy field working machine, the traveling body is turned by the steering operation of the steered wheels in a state where the working device is raised to a predetermined height, and thereafter, the steered wheels are returned to the straight traveling direction. Is detected, the control device is controlled to lower the working device to the field scene, and after the lowering, the control mode of the control device is set so that the clutch is engaged by operating the forcible lifting operation tool to the lowering position. The operation and effect are as follows.

A second feature of the present invention (claim 2) is that, in claim 1, when the steering wheel is steered from a straight running posture to a turning posture while the working device is maintained at a field scene level. The control mode of the control device is set so as to raise the working device to a level away from the field scene, and the operation and effect are as follows.

According to a third feature of the present invention, as described at the beginning, a working device is provided to be capable of driving up and down with respect to a traveling machine body, and a state of transmitting power to the working device and shutting off the power. Equipped with a clutch that can be switched between
The clutch is held at a neutral position when not operated, and is provided with a forcible lifting / lowering operating tool that can be freely switched between an ascending position and a descending position with reference to the neutral position. The working device is raised to a level separated from the field scene with the disengagement operation, and the working device is lowered to the field scene while maintaining the disengaged state of the clutch by operating the forcible lifting / lowering operating tool to the lowered position, After the descent, in a paddy working machine provided with a control device for performing the engagement operation of the clutch by operating the forcible lifting / lowering operation tool to the lowered position again, the steering is performed in a state where the working device is raised to a predetermined height. The turning of the traveling body is performed by the steering operation of the wheels, and thereafter, when it is detected that the steered wheels are returned to the straight traveling direction, the work device is lowered to the field scene. In addition, the control mode of the control device is set so that the clutch is engaged by operating the forcible lifting / lowering operating tool twice to the lowered position after the descent, and its operation, and The effects are as follows.

According to a fourth feature of the present invention (claim 4), when the steering wheel is steered from a straight running posture to a turning posture in a state where the working device is maintained at a field scene level. The control mode of the control device is set so as to raise the working device to a level away from the field scene, and the operation and effect are as follows.

According to the first feature, the traveling machine is turned by an operation such as raising the working device by some means and operating the steering handle large, and the turning of the traveling machine is completed and the steering handle is turned off. When the steered wheels are returned to the straight running direction by an operation such as returning the work device, the control device performs control to lower the work device to the field scene. Thus, by operating the forcible lifting / lowering operating tool to the lowered position after the working device is automatically lowered, the control device can perform the clutch engagement operation at an arbitrary timing. In other words, since the lowering of the working device is performed in conjunction with the operation (returning operation) for finishing the turning of the traveling machine body, not only the lowering operation is canceled but also the timing of the lowering becomes appropriate, and the clutch engaging operation is performed. Since the clutch engagement operation is performed by operating the forcible lifting lever, the operation feeling is not uncomfortable.

According to the second feature, since the control device starts to raise the working device in conjunction with the start of turning of the traveling body, the working device can be raised without performing any special operation, and the timing of starting the rising No wonder.

According to the third feature, the working unit is lifted by some means, the turning of the traveling body is performed by an operation such as greatly operating the steering handle, and the turning of the traveling body is completed and the steering handle is returned. When the steering wheel is returned to the straight running direction by an operation such as the operation, the control device performs control to lower the working device to the field scene, so that the operator needs to perform a special operation of lowering the working device. In this way, by operating the forced lifting / lowering operation tool twice to the lowered position after the working device has been automatically lowered, the control device can perform the clutch engagement operation at an arbitrary timing. In other words, since the lowering of the working device is performed in conjunction with the operation (return operation) for finishing the turning of the traveling body, not only the lowering operation is canceled but also the timing of the lowering becomes appropriate. In the case of a device provided with a forced lifting operation tool, when the forced lifting operation device is operated to the lower position, 1
With the second operation, the working device is lowered, and the clutch is operated for the second time, and the clutch operation is performed by operating the forced lifting / lowering operation tool twice to the lowered position. There is no sense of incongruity.

According to the fourth feature, the control device starts to raise the working device in conjunction with the start of turning of the traveling body, so that the working device can be raised without performing any special operation, and the timing of starting the rising. No wonder.

[Effects of the Invention] Therefore, when turning on a headland, it is not necessary to perform a lowering operation of the working device, so that the steering operation can be performed accurately over a long time, and the operation of engaging the clutch can be sensed. The paddy field working machine that can be quickly and easily operated without difficulty is rationally configured (claim 1). or,
The turning operation of the traveling machine body can be performed more easily without specially performing the lifting operation of the working device (claim 2). Furthermore, when turning on a headland, there is no need to perform a special lowering operation of the working device, so that the steering operation can be performed with a long time and accurately, and the operation of engaging the clutch can be easily and sensuously sensed. The paddy field working machine was rationally configured (claim 3). Further, the turning of the traveling body can be performed more easily without specially performing the lifting operation of the working device (claim 4).

[0014]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a drive-type front wheel 1 and a drive-type rear wheel 2 that are steered.
The engine 4 is mounted on the front part of the traveling body 3 provided with a belt-type continuously variable transmission V to which power from the engine 4 is transmitted and the transmission case 5 are arranged at the front part of the traveling body 3. In addition, a steering handle 6 for steering the front wheels 1 and a driver seat 7 on which an operator sits are disposed at the center of the traveling body 3, and are driven up and down by a lift cylinder 8 with respect to the rear end of the traveling body 3. A seedling planting device A as a working device is connected via a link mechanism 9 to constitute a rice planting machine as a paddy working machine.

The seedling planting apparatus A includes a planting mechanism 1 having a planting arm from the lower end of a mat-like seedling W placed on a seedling mounting table 10.
1 is configured to cut out seedlings one by one and plant and operate the same in the field scene S. The lower part is provided with a plurality of leveling floats 12, and the leading end thereof enters the field scene S at the left and right positions. The line marker 13 is configured to be switchable between a posture and a non-acting posture separated upward from the field scene S.

On the right side of the driver's seat 7, the seedling planting device A is lifted and the planting clutch C built in the transmission case 5 is mounted.
The raising and lowering lever 15 performs the control of the above, as shown in FIG. 4, the raising and lowering lever 15 is set to the "down" position in the path formed in the guide 16 to lower the seedling planting apparatus A, By setting the seedling planting device A at the "up" position, the seedling planting device A is raised, and at the "neutral" position, the seedling planting device A is linked with a control system to maintain the planting device A at that level. When it is set to the “in” position, the planting clutch C is operated and the leveling float 1 provided in the seedling planting device A is set.
2 is linked with the control system so as to perform an automatic elevating control for maintaining a predetermined height with respect to the field in a state of touching the field scene S, and when the position is set to the “off” position, the planting clutch C is turned off. When the raising and lowering lever 15 is set to the "automatic" position, the raising and lowering of the seedling planting apparatus A is permitted in accordance with the operation of the compulsory raising and lowering lever described later, and at the same time, the planting clutch C
Enables automatic cutting operation. As shown in FIG. 1, a potentiometer type lever sensor 17 for measuring the operation position of the elevating lever 15 is provided at the base end of the elevating lever 15.

As shown in FIG. 5, one of the plurality of leveling floats 12 which is positioned at the center in the left-right direction is supported so as to be swingable about a lateral axis P with respect to the seedling planting apparatus A, A potentiometer type float provided with a spring (not shown) for urging the front position downward, and measuring the amount of swing of the leveling float 12 from the vertical displacement of the front of the leveling float 12 A sensor 18 is provided. At the time of automatic raising / lowering control of the seedling planting apparatus A, the seedling planting apparatus A is controlled so that the signal from the float sensor 18 and the signal from the potentiometer type sensitivity setting device 20 (see FIG. 5) operated by the dial 19 are balanced. The control operation is set so that the lifting and lowering is performed. Also, as shown in FIG.
At the base end of the link mechanism 9, there is provided a potentiometer type level sensor 21 for measuring the level of the seedling planting apparatus A from the swinging posture of the link mechanism 9, and as shown in FIG. The clutch 22 is configured to be turned on and off by the operation of the motor 22 and is linked to a planting clutch sensor 23 that determines the state of the clutch C.

As shown in FIG. 3, on the right side of the post portion 25 of the steering handle 6, there is provided a forced lifting / lowering lever 26 as a forced lifting / lowering operation tool for forcibly lifting / lowering the seedling planting apparatus A. Is urged by a spring (not shown) to a neutral position N which is in a substantially horizontal posture, and the seedling planting device A is in a posture in which its end is directed upward with respect to the neutral position N.
Position U for raising the height of the seedling to the upper limit, a lowering position D for lowering the seedling planting apparatus A to a working height for automatically raising and lowering the seedling planting device A in a posture in which the end is directed downward with respect to the neutral position N, and a neutral position N as a reference. The right marker position R at which the right line marker 13 is switched to the operating posture with its end directed rearward.
And a left marker position L for switching the left line marker 13 to the operating posture with its end portion facing forward with respect to the neutral position N. Incidentally, the lowering position D is also used as a position for engaging and operating the planting clutch C, as described later.

At the base end of the forcible raising / lowering lever 26, an ascending switch 27 for detecting that the forcibly raising / lowering lever 26 has been operated to the ascending position U, and a descending switch for detecting that the forcibly raising / lowering lever 26 has been operated to the descending position D. 28, and a pair of marker switches 29, 29 for detecting operation to the right marker position R or the left marker position L. The left and right line markers 13, 13 are operated to the storage position by the pulling force of the wire in conjunction with the raising of the seedling planting device A, and when the storage position is reached, a lock mechanism (not shown) is used. It is to be held in the storage position,
When the forcible raising / lowering lever 26 is operated to the left marker position L or the right marker position R, the holding by the corresponding lock mechanism is electrically released, and the operating posture is switched.

As shown in FIG. 2, a pitman arm 32 is provided at a lower end of a handle shaft 30 linked to the steering handle 6 via a gear reduction mechanism 31, and the pitman arm 32 and the front wheels 1 are mechanically linked. Thus, a system for steering the front wheel 1 in conjunction with the operation of the steering handle 6 is configured, and the steering operation amount of the front wheel 1 is measured on the swing axis of the pitman arm 32 from the swing amount. A potentiometer type steering sensor 33 is provided. A load sensor 34 for measuring the torque acting on the handle shaft 30 and the direction in which the torque acts is provided on the handle shaft 30.
During operation of the handle shaft 3 via a gear interlocking mechanism 35 provided on the handle shaft 30 based on the detection result of the load sensor 34.
DC motor type assist motor 36 that transmits driving force to zero
And the power steering mechanism is configured.

In this rice transplanter, a control system is constructed at the edge of the ridge as shown in FIG. That is, a control device 38 including a microprocessor (not shown) is provided with the lever sensor 17, the sensitivity setting device 20 operated by the dial 19, the float sensor 18, the up switch 27 and the down switch. A switch 28, the left and right marker switches 29, 29, the level sensor 21, the steering sensor 33, the load sensor 34, and a speed sensor 3 that measures the speed of the traveling body 3 from the number of rotations of wheels.
An input system for inputting a signal from the planting clutch sensor 23 and the planting clutch sensor 23 is formed, and an electromagnetic proportional solenoid valve 4 for controlling the lift cylinder 8 from the control device 38 is formed.
0, the clutch motor 22, a display device 41 such as a lamp type or a liquid crystal display type provided on a panel at a position in front of the driver's seat 7, electromagnetic solenoids 42 for releasing the lock mechanism, and the assist motor. A system for outputting a control signal is formed between the control device and the control device.

As shown in the flowchart of FIG. 6, in the elevating control routine, a signal value from the lever sensor 17 is input to determine the operating position of the elevating lever 15, and when the operating position is the "elevating" position, the electromagnetic The control for raising the seedling planting apparatus A by operating the valve 40 to the rising position is performed, and the planting clutch C is set to the disengaged state (if it is already disengaged, the disengagement is maintained) (# 101 to # 104) Steps),
If it is in the "down" position, the automatic ascent / descent routine is executed, and the planting clutch C is set to the disengaged state (if it is already in the disengaged state, the disengagement is maintained) (# 105, # 200,
(Step # 106) If the switch is in the "ON" position, the automatic lifting / lowering routine is executed, and the planting clutch C is set to the ON state (if it is already in the ON state, the OFF state is maintained) (# 106).
107, # 200, and # 108 steps), if the position is the automatic position, the first forced lifting / lowering routine and the second forced lifting / lowering routine are executed (# 109, # 300, and # 400 steps). Since the lifting lever 15 can be determined to be in the "neutral" position, the planting clutch C is set to the disengaged state (if it is already in the disengaged state, the disconnection is maintained) (# 110 step).

In the automatic raising / lowering routine (step # 200), a control form is set as shown in the flowchart of FIG. 7. In this routine, a signal from the sensitivity setting unit 20 is input and set as a control target. A signal from the float sensor 18 is input, and when the respective deviations are within a dead zone set based on the control target, the elevation control is not performed. When the respective deviations are outside the dead zone, the electromagnetic valve 40 is used.
By supplying a current proportional to the deviation, the valve opening corresponding to the deviation is set, and the larger the deviation, the faster the ascending and descending (steps # 201 to # 205). This control is performed by raising and lowering the seedling planting apparatus A so that the target posture of the leveling float 12 measured by the float sensor 18 is maintained at the posture set by the sensitivity setting device 20, thereby setting the seedling planting apparatus A in the field scene. It moves up and down following S.

In the first forcible raising / lowering routine (step # 300), as shown in the flow chart of FIG. 8, when the raising switch 27 is turned on by the operation of the forcible raising / lowering lever 26, the level is measured by the level sensor 21. As long as the level of the seedling planting device A is not the upper limit, the planting clutch C is turned off, and an alarm is displayed on the display device 41 for allowing the operator to recognize that the planting clutch C is in the off state,
Control for raising the seedling planting device A to the upper limit is performed (steps # 301 to # 305). When the down switch 28 reaches the ON state, the level sensor 2
When it is determined based on the signal from 1 that the seedling planting device A is not at the upper limit position, the planting clutch C is turned on to stop the alarm display on the display device 41, and conversely,
When it is determined that the seedling planting device A is at the upper limit position when the descending switch 28 reaches the ON state, the descending control of the seedling planting device A is started, and after the leveling float 12 has touched down, the automatic climbing and descending routine is performed. (# 306 to # 3
10 steps). In this control, the lifting lever 15 is "automatic".
When the seedling planting device A is in the lowered position, the planting device A is forcibly raised and lowered by operating the forced raising / lowering lever 26 when it is in the position. The control for engaging and disengaging the attached clutch C is performed.

In the second forcible raising / lowering routine (step # 400), as shown in the flow chart of FIG. 9, when a signal from the steering sensor 33 is input and the steering operation angle (steering angle) is equal to or more than α, seedlings are planted. Only when the device A is in the automatic raising / lowering control state, the planting clutch C is turned off, and an alarm is displayed on the display device 41 for recognizing the worker that the planting clutch C is in the off state, Control for raising the seedling planting device A to the upper limit is performed (steps # 401 to # 406). Also, if the steering operation angle is returned to β or less after the steering operation in this way, only when the level of the seedling planting device A measured by the level sensor 21 is at the upper limit position, The descending control of the seedling planting apparatus A is started, and the leveling float 12 is set in the field scene
After the touchdown, the routine goes to an automatic lifting / lowering routine (steps # 407 to # 409). In this control, by setting the angle β smaller than the angle α as shown in FIG. 10, it is possible to reliably determine that the returning operation has been performed.

Since the mode of the elevation control is set in this manner, when the traveling body 3 reaches the edge of the ridge and the steering handle 6 is largely operated to turn the traveling body 3 during work, the planting clutch is automatically set. By raising the seedling planting device A to the upper limit by performing the cutting operation of C, the labor of the operator is reduced, and the turning of the traveling machine body 3 is completed by the operation of the steering handle 6. When the steering handle 6 is operated to return, the seedling planting apparatus A descends until the leveling float 12 comes into contact with the field scene S and performs automatic elevating control. Since the planting clutch C is maintained in the disengaged state after A has descended, the display device 41 indicates on the display device 41 that the planting clutch C is in the disengaged state so as to call attention of the operator. Has a shall, has become shall perform operations to work seedling planting enters the clutch C planting at any time by operating the forcible lift lever 26 in the lowered position D. When the planting device A is to be forcibly lifted because the forcible raising / lowering lever 26 is provided, the planting clutch C is disengaged by operating the forcible lifting / lowering lever 26 to the ascending position U, thereby raising the seedling. The forcing device A is forcibly raised, and by operating the forcibly raising and lowering lever 26 to the lowering position D in this raised state, the seedling planting device A can be lowered to a level at which the automatic raising and lowering control is performed. After the seedling planting apparatus A descends in this manner, the operation of engaging the planting clutch C can be performed by operating the forcible raising / lowering lever 26 to the descending position D in the same manner as described above.

In this rice transplanter, control is performed to set the assist force of the power steering mechanism on the basis of the traveling speed of the traveling machine body 3 and the amount of sinking of the wheels 1 and 2 with respect to the field scene S during work. The control mode of the control device 38 is set. That is, as shown in the flowchart of FIG. 11, when the signal from the speed sensor 39 is input to set a coefficient (J) that is inversely proportional to the traveling speed, and when the seedling planting apparatus A is not in the automatic elevating control state, Sets the coefficient (K) to "1". Conversely, if it is determined that the seedling planting device A8 is in the automatic elevating control state, the seedling planting device A is set based on the signal from the level sensor 21. The height of the wheel 1,
2 can be determined to be deeply sunk, so a coefficient (K) that is directly proportional to this height is set, and a value obtained by multiplying this coefficient (K) by the coefficient (J) is set as a control parameter, and By supplying an intermittent signal based on the duty ratio to the assist motor 36, the power supplied to the assist motor can be adjusted in a PWM manner to adjust the assist force (steps # 501 to # 507).

[Other Embodiments] In the present invention, besides the above-described embodiment, for example, the control form of the first forcible lifting / lowering routine can be set as shown in the flowchart of FIG. That is, when the raising switch 27 reaches the ON state by the operation of the forcible raising / lowering lever 26, the planting clutch C is disengaged unless the level of the seedling planting device A measured by the level sensor 21 is the upper limit, The display device 4
For example, an alarm is displayed for the worker to recognize that the planting clutch C is in the disengaged state, and control is performed to raise the seedling planting device A to the upper limit (# 601 to # 601).
605 steps). When the descending switch 28 has reached the ON state, if it is determined that the seedling plant A is not at the upper limit position based on the signal from the level sensor 21, the number of times the descending switch 28 has reached the ON state is 2 times. If it is the first time, the planting clutch C is engaged and the display device 41 is operated.
Is stopped, and conversely, when the descending switch 28 reaches the ON state, when it is determined that the seedling planting device A is at the upper limit position, the descending control of the seedling planting device A is started and the leveling float is started. After the grounding of the ground 12, the automatic lifting and lowering routine is executed (steps # 606 to # 611). In this control, when the raising and lowering lever 15 is in the "automatic" position, the forcible raising and lowering of the seedling planting apparatus A is performed by operating the forcible raising and lowering lever 26. When the operation is performed to the lowering position, the control for engaging and operating the planting clutch C is performed.

Further, according to the present invention, the seedling planting device A (working device) is raised to the upper limit by operating the forcible raising / lowering lever 26 (forcibly raising / lowering operation tool) to the raised position when the traveling machine body 3 turns, and When the operating direction of the traveling machine 3 is returned to the straight running state, the lowering of the seedling planting apparatus A is started, and after this lowering, the forced operation of the raising / lowering lever 26 is performed to perform the operation of engaging the planting clutch C. It is also possible to set the control mode to set the control operation of the device 38. Further, the present invention can be applied to a direct sowing machine other than the rice transplanter.

[Brief description of the drawings]

FIG. 1 is an overall side view of a rice transplanter.

FIG. 2 is a schematic diagram of a power steering mechanism.

FIG. 3 is a side view showing an arrangement of a forced lifting lever.

FIG. 4 is a plan view of an operation path of a lifting lever.

FIG. 5 is a block circuit diagram of a control system.

FIG. 6 is a flowchart of a lifting control routine;

FIG. 7 is a flowchart of an automatic elevating routine.

FIG. 8 is a flowchart of a first forced lifting / lowering routine;

FIG. 9 is a flowchart of a second forced lifting / lowering routine;

FIG. 10 is a graph showing a steering angle in a graph.

FIG. 11 is a flowchart of an assist force setting routine.

FIG. 12 is a flowchart of a first forcible lifting / lowering routine according to another embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steering wheel 3 Traveling body 26 Forced raising / lowering operation tool 38 Control device A Working device C Clutch D Lowering position N Neutral position S Field scene U Raising position

Claims (4)

[Claims] An operating device is provided to be able to drive up and down with respect to a traveling machine body, and a clutch is provided which can be switched between a state where power is transmitted to the operating device and a state where power is cut off, and is held at a neutral position when not operated. A forced lifting / lowering operation tool that can be freely switched between an ascending position and a descending position with respect to the neutral position is provided. By operating the forcible lifting / lowering operating device to the ascending position, the operation with the clutch disengagement operation is performed. By raising the device to a level away from the field scene and operating the forced lifting operation device to the lowered position, the working device is lowered to the field scene while maintaining the disengaged state of the clutch. A paddy field working machine provided with a control device for operating the clutch by operating the tool again to the lowered position, wherein the working device is raised to a predetermined height. The turning of the traveling body is performed by the steering operation of the steered wheels, and thereafter, when it is detected that the steered wheels have been returned to the straight traveling direction, the work device is controlled to descend to the field scene, and A paddy working machine in which the control mode of the control device is set so that the clutch is operated by operating the forced lifting / lowering operation tool to the lowered position after the lowering. 2. When the steering wheel is steered from a straight running posture to a turning posture while maintaining the work device at a field scene level, the work device is raised to a level separated from the field scene. The paddy field working machine according to claim 1, wherein a control mode of the control device is set. 3. A work device is provided to be able to drive up and down with respect to the traveling machine body, and a clutch is provided which can be switched between a state where power is transmitted to the work device and a state where power is cut off, and is held at a neutral position when not operated. A forced lifting / lowering operation tool that can be freely switched between an ascending position and a descending position with respect to the neutral position is provided. By operating the forcible lifting / lowering operating device to the ascending position, the operation with the clutch disengagement operation is performed. By raising the device to a level away from the field scene and operating the forced lifting operation device to the lowered position, the working device is lowered to the field scene while maintaining the disengaged state of the clutch. A paddy field working machine provided with a control device for operating the clutch by operating the tool again to the lowered position, wherein the working device is raised to a predetermined height. The turning of the traveling body is performed by the steering operation of the steered wheels, and thereafter, when it is detected that the steered wheels have been returned to the straight traveling direction, the work device is controlled to descend to the field scene, and A paddy working machine in which the control mode of the control device is set so that the clutch is operated by operating the forced lifting operation tool to the lowered position twice after the lowering. 4. When the steering wheel is steered from a straight running posture to a turning posture while maintaining the working device at a field scene level, the working device is raised to a level away from the field scene. The paddy working machine according to claim 3, wherein a control mode of the control device is set.