JPH1052129A - Sulky type rice transplanter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the judgment about the hardness of muddy soil in a field, the regulation (a change in setting of the reference posture of a land grading float) of a detection sensitivity of a float sensor based on the judgment by control operations of a controlling means and further a reduction in labor of an operator when performing transplanting operations and simplify the constitution required therefor. SOLUTION: This sulky type rice transplanter is equipped with a float sensor S6 for detecting the extent of the vertical shaking displacement of a land grading float, brought into contact with the ground and urged with an urging means when performing transplanting operations, and a controlling means 13 for automatically controlling the lifting and lowering of a seedling transplanting device relatively to a mobile device so as to return the land grading float to the prescribed reference posture. In this case, a torque sensor S4 for detecting the operating torque when performing steering operations is installed and the controlling means 13 is capable of regulating the detection sensitivity of the float sensor S6 to the insensitive side with increasing operating torque sensed by the torque sensor S4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a float sensor for detecting the amount of vertical swing displacement during planting work of a leveling float urged to touch the ground by an urging means, and based on a detection value from the float sensor. The present invention relates to a riding type rice transplanter having control means for automatically controlling the raising and lowering of a seedling planting device with respect to a traveling machine so that a leveling float returns to a predetermined reference posture.

[0002]

2. Description of the Related Art In a riding rice transplanter as described above,
The control means, based on a detection value from the float sensor,
By automatically raising and lowering the seedling planting device with respect to the traveling machine so that the leveling float returns to the predetermined reference posture, the seedling planting device can set a suitable planting depth regardless of changes in the undulations of the field. To be planted with high accuracy. The reference posture of the leveling float is to be appropriately changed according to the hardness of the mud in the field, and the setting change is as follows.
An operator judges the hardness of the mud in the field and operates the manual setting device based on the judgment. However, depending on the field, the hardness of the field mud frequently changes in one of the fields. In such a case, it is necessary to frequently change the setting of the reference posture of the terrain float during the planting operation, so that the worker is forced to work considerably during the planting operation.

Therefore, conventionally, for example, JP-A-8-14
As disclosed in Japanese Patent No. 0433, etc., a groove mark depth detecting means for detecting a groove mark depth formed after the leveling float has passed through the mud surface is provided, and a detection value from the groove mark depth detecting means is provided. Based on the above, the control means automatically determines the hardness of the mud in the field, and based on the determination, changes the setting of the reference posture of the leveling float, thereby reducing the labor of the worker during the planting operation. There was something that could be reduced.

[0004] Incidentally, since the rocking fulcrum of the leveling float is set at the rear side of the leveling float, the reference attitude of the leveling float depends on the hardness of the mud when the field mud is hard, for example. By lowering the seedling planting device so that the contact pressure of the leveling float is increased, it is changed to the upward direction by lowering the seedling planting device. If the field mud is soft, the contact pressure of the leveling float is reduced according to the mud hardness. Thus, the raising operation of the seedling-planting device causes the seedling-planting device to change in the forward-downward direction. Since the leveling float becomes more difficult to swing up and down with the ups and downs of the field as the contact pressure becomes higher, it is also difficult to detect the vertical swing displacement amount of the leveling float by the float sensor. Conversely, the leveling float becomes more likely to swing up and down with the ups and downs of the field as the contact pressure becomes lower, and accordingly, the amount of up and down swing displacement of the leveling float by the float sensor becomes easier. That is, when the field mud is hard, the sensing sensitivity of the float sensor is changed to the insensitive side by changing the reference posture of the leveling float, and when the field mud is soft, the float sensor is changed by changing the reference position of the leveling float. Is changed to the sensitive side.

[0005]

However, according to the above-mentioned prior art, when configuring the groove mark depth detecting means, a ground contact body that follows the surface of a field mud through which a leveling float does not pass, or a leveling float is used. It is necessary to provide a ground contact body that follows the bottom of the groove trace formed in the field mud after passing, and a configuration for avoiding damage due to the entry of the ground body into the field mud during reverse movement, etc. Because of the necessity, the configuration has been complicated.

An object of the present invention is to determine the hardness of field mud,
In addition, the adjustment of the sensitivity of the float sensor based on the determination (change of the setting of the reference posture of the leveling float) can be performed by the control operation of the control means, so that the labor of the worker during the planting operation can be reduced. Therefore, the configuration required for that purpose can be simplified.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a vertical swing displacement amount at the time of planting work of a leveling float urged to be grounded by an urging means is provided. And a control means for automatically controlling the raising and lowering of the seedling planting device with respect to the traveling machine so that the leveling float returns to a predetermined reference posture based on a detection value from the float sensor. In the rice transplanter, a torque sensor for detecting an operation torque at the time of steering operation is provided, and as the operation torque detected by the torque sensor increases, the control means adjusts the sensitivity of the float sensor to the insensitive side. Configured.

According to the first aspect of the present invention, when the steering operation at the time of headland turning or the like becomes heavy and the operating torque at the time of the steering operation detected by the torque sensor increases, the control means: Based on the detected value, it is determined that the mud in the field has hardened, and the seedling planting device is lowered so that the ground pressure of the leveling float according to the mud hardness is obtained, and the ground pressure of the leveling float is increased. The reference attitude of the leveling float is changed in a certain direction (generally, a forward ascending direction). As a result, the sensitivity of the float sensor is adjusted to the sensitivity on the insensitive side according to the detection value from the torque sensor. Further, when the steering operation at the time of headland turning or the like becomes lighter and the operating torque at the time of the steering operation detected by the torque sensor becomes smaller, the control means makes the mud of the field softer based on the detected value. And raising the seedling planting equipment so that the ground pressure of the leveling float according to the mud hardness can be obtained,
The reference attitude of the leveling float is changed in the direction in which the ground pressure of the leveling float decreases (generally, in the forward descending direction). Thereby, the sensitivity of the float sensor is adjusted to the sensitivity on the sensitive side according to the detection value from the torque sensor. That is, by the control operation of the control means based on the detection value from the torque sensor, the determination of the hardness of the mud in the field and the adjustment of the sensitivity of the float sensor based on the determination (change of the reference attitude setting of the leveling float) are automatically performed. Since it is possible to perform the planting work, the labor of the worker at the time of planting work can be reduced.

[0009] Further, as the field mud becomes harder, the steering operation during headland turning becomes heavier, and conversely, as the field mud becomes softer, the steering operation becomes lighter during headland turning. By making effective use of, the simple configuration of only providing a torque sensor that detects the operating torque at the time of steering operation, to determine the hardness of the mud in the field, and to change the setting of the reference attitude of the leveling float based on the determination Since it can be performed by the control operation of the control means, such as when equipped with a groove mark depth detection means, a ground contact body that follows the surface of the field mud where the leveling float does not pass, or after the leveling float passes It is no longer necessary to provide a ground contact body that follows the bottom of the groove trace formed in the mud of the field. Also, with this, it is possible to prevent such a situation that the ground contact bodies enter the field mud, etc. and break when the vehicle reverses.
A configuration for avoiding such a situation becomes unnecessary. That is,
A configuration for determining the hardness of the field mud and adjusting the sensing sensitivity of the float sensor based on the determination by the control operation of the control unit is compared with a case where the groove mark depth detecting unit is provided. Can be simplified.

Therefore, the determination of the hardness of the field mud, and
Adjustment of the sensitivity of the float sensor based on the judgment
Since it can be performed by the control operation of the control means based on the detection value from the torque sensor, the labor of the worker at the time of planting work can be reduced, and the configuration required for that can be simplified.

In the invention according to claim 2 of the present invention,
In the first aspect of the present invention, the torque sensor provided in the electric power steering device is also used as the torque sensor for adjusting the sensing sensitivity.

According to the second aspect of the present invention, a rice transplanter provided with an electric power steering device is provided with a torque sensor for detecting an operation torque at the time of steering operation. Since the torque sensor of (1) is also used as the torque sensor for adjusting the sensitivity, it is not necessary to newly provide a torque sensor for adjusting the sensitivity.

Accordingly, the determination of the hardness of the field mud, and
The configuration required for automatically adjusting the sensitivity of the float sensor based on the determination by the control operation of the control means can be further simplified.

According to the third aspect of the present invention,
A float sensor for detecting the amount of vertical swing displacement at the time of planting the leveling float that is grounded and biased by the biasing means, and the leveling float is returned to a predetermined reference posture based on a detection value from the float sensor. In a riding type rice transplanter provided with control means for automatically controlling the raising and lowering of the seedling planting device with respect to the traveling machine body, load detecting means for detecting an engine load is provided, and the engine load detected by the load detecting means is large. The control means adjusts the sensitivity of the float sensor to be less sensitive.

According to the third aspect of the invention, when the engine load detected by the load detecting means during planting and running increases, the control means determines that the mud in the field has become hard based on the detected value. Judgment and lowering the seedling planting equipment so that the ground contact pressure of the leveling float according to the mud hardness is obtained, and leveling in the direction in which the leveling pressure of the leveling float increases (generally in the upward direction). The reference position of the float will be changed. As a result, the sensitivity of the float sensor is adjusted to the insensitive sensitivity in accordance with the value detected by the load detecting means. Further, when the engine load detected by the load detecting means during planting and running decreases, the control means determines that the mud in the field has become soft based on the detected value, and according to the mud hardness. Raise the seedling planting equipment so that the ground pressure of the leveling float can be obtained,
The reference attitude of the leveling float is changed in the direction in which the ground pressure of the leveling float decreases (generally, in the forward descending direction). As a result, the sensitivity of the float sensor is adjusted to the sensitivity on the sensitive side according to the detection value from the load detection means. That is, the control operation of the control means based on the detection value from the load detection means determines the hardness of the mud in the field and adjusts the sensitivity of the float sensor based on the determination (changes the setting of the reference attitude of the leveling float). Since the operation can be performed automatically, the labor of the operator during the planting operation can be reduced.

Further, the effect that the engine load at the time of planting and running is increased as the hardness of the field mud becomes harder, and conversely, the engine load at the time of planting and running is reduced as the hardness of the field mud becomes softer is effectively used. By this means, the control means can determine the hardness of the mud in the field and change the setting of the reference attitude of the leveling float based on the determination with a simple configuration that simply provides load detection means for detecting the engine load during planting and running. Since it can be performed by control operation, as in the case of equipping the groove mark depth detecting means, a ground contact body that follows the surface of the field mud where the leveling float does not pass, or a field mud after the leveling float passes There is no need to provide a grounding body or the like that follows the bottom of the groove trace formed in the ground. In addition, a situation in which the grounding bodies enter the field mud or the like and are damaged when the vehicle travels backward does not occur, so that a configuration for avoiding such a situation is not required. That is, a configuration for enabling the determination of the hardness of the mud in the field and the adjustment of the sensitivity of the float sensor based on the determination by the control operation of the control means is provided when the groove mark depth detection means is provided. It can be simplified in comparison.

Accordingly, the determination of the hardness of the field mud, and
Adjustment of the sensitivity of the float sensor based on the judgment
Since it can be performed by the control operation of the control means based on the detection value from the load detection means, the labor of the worker during the planting operation can be reduced, and the configuration required for that can be simplified.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an overall side view of a riding type rice transplanter. This riding type rice transplanter includes a riding type traveling machine 1 and
A seedling planting device 4 for eight-row planting is connected to the rear of the traveling machine body 1 via a lifting link mechanism 2 so as to be movable up and down by the operation of a hydraulic lift cylinder 3. An engine 5 is mounted on a front part of the traveling body 1, and power taken out of the engine 5 is transmitted to a hydrostatic continuously variable transmission 6 and a gear type transmission 7 provided at a rear part of the traveling body 1. Via the front wheel 8, the rear wheel 9, and the seedling planting device 4, the transmission is performed. The front wheel 8
The steering operation is performed by a steering handle 10 provided on the control section 1A of the traveling body 1.

As shown in FIG. 2, the hydrostatic continuously variable transmission 6 includes a trunnion shaft 6 a driven by an electric cylinder 11.
The switching operation of forward / backward movement and the speed change operation in forward / backward movement can be performed steplessly. The electric cylinder 11 is a speed setting device 1 disposed on the right side of the steering handle 10 in the control section 1A.
The operation is controlled by a control device 13 as a control means including a microcomputer mounted on the traveling body 1 so that the target speed manually set by the control unit 2 is obtained. That is, the control unit 13 provides the traveling body 1 based on the target speed set by the speed setting unit 12.
Speed control means 13A for controlling the traveling speed of the vehicle is provided as a control program. The speed setting device 12 includes an accelerator lever 12A that is swingably operated in the front-rear direction, and a lever sensor S1 that detects an operation position of the accelerator lever 12A. The electric cylinder 11 is provided with a stroke sensor S2 for detecting the actual expansion / contraction operation amount. The vehicle speed control means 13A provides a target expansion / contraction operation amount of the electric cylinder 11 corresponding to a target speed manually set by the speed setting device 12. And the feedback control that controls the operation of the electric cylinder 11 so that the actual expansion / contraction operation amount of the electric cylinder 11 detected by the stroke sensor S2 matches.

The engine 5 is provided with a rotation sensor S3 for detecting the engine speed. The control unit 13 controls the engine 5 to determine the appropriate speed according to the target speed manually set by the speed setting unit 12 and the speed. The actual speed of the engine 5 detected by the sensor S3 is compared with the actual speed. If the actual speed of the engine 5 is lower than the appropriate speed corresponding to the target speed, the optimum speed at which the actual speed becomes the appropriate speed is obtained. Is controlled so that the traveling speed is reduced by controlling the operation of the electric cylinder 11. If the actual rotation speed of the engine 5 detected by the rotation sensor S3 increases after the deceleration, the increased actual rotation speed falls within the range of the target speed manually set by the speed setting device 12. Electric cylinder 1 so that the optimal speed
1 is controlled to increase the traveling speed. That is, the load setting means A configured to detect the engine load fluctuating due to the hardness of the field mud is configured from the speed setting device 12 and the rotation sensor S3, and the control device 1
3, a load vehicle speed control means 13B for controlling the traveling speed of the traveling machine 1 based on the engine load detected by the load detection means A is provided as a control program.
The load vehicle speed control means 13B can be switched between a state in which the control operation is executed and a state in which the control operation is not executed by turning on / off a vehicle speed control switch 14 provided in the control section 1A.

The operating shaft 10A of the steering handle 10
Is equipped with a torque sensor S4 for detecting an operation torque at the time of steering operation, and a gear type transmission mechanism 1
The control device 13 controls the operation of the electric motor 16 by controlling the operation of the electric motor 16 so as to obtain an assist force corresponding to the operation torque detected by the torque sensor S4 at the time of steering operation. The shaft 10A is rotated auxiliary. That is, the control device 13 includes, as a control program, an assist force control unit 13C that controls the assist force on the steering handle 10 based on the detection value from the torque sensor S4 during the steering operation. Then, the assist force control means 13C, the gear type transmission mechanism 15, the electric motor 1
6, and an electric power steering device B configured to reduce the steering operation force at the time of steering operation by the torque sensor S4.

As shown in FIGS. 3 and 4, the seedling planting apparatus 4 has a two-part structure that can be separated into a left-side planting unit 4A and a right planting unit 4B. With
The longitudinal axis P1, of each of the left and right seedling planting devices 4A, 4B.
By the swinging operation around P2, the working posture (see FIG. 3) in which the left and right seedling planting units 4A and 4B are connected in a state of being lined up in a forward and horizontal line, respectively, The configuration is such that the attitude can be changed to a storage attitude (see FIG. 4) in which each of 4A and 4B faces sideways and faces each other. By changing the posture of the seedling planting device 4 from the working posture to the storage posture, the amount of the seedling planting device 4 projecting in the machine lateral width direction can be reduced. In other words, when the rice transplanter is driven on a road or transported by being loaded on a carrier such as a truck, the seedling placement device 4 is switched to the retracted position to reduce the amount of overhang in the lateral direction of the machine. When traveling on a road or transporting by truck or the like, it is possible to suppress the occurrence of such a problem that the seedling planting device 4 that protrudes greatly from the lateral width direction of the traveling body 1 comes into contact with other objects.

The structure of the seedling planting apparatus 4 will be described in detail.
The seedling planting device 4 includes a fixed frame 17 connected to a rear end of the lifting link mechanism 2, and a swing frame 18 connected to both left and right ends of the fixed frame 17 so as to be able to swing left and right around a vertical axis P 1. A feed case 20 connected to the swing end of each swing frame 18 via a support bracket 19 so as to be able to swing left and right around a longitudinal axis P2, and a corner extending from the feed case 20 to the left and right. A pipe-shaped support frame 21, a planting transmission case 22 extending rearward from both left and right ends of each support frame 21, and a rotary planting mechanism pivotally supported on the left and right sides of the rear of each planting transmission case 22. 23. In the working posture, four right and left four seedling rests 24 connected to each planting mechanism 23 so as to be able to reciprocate and laterally move with a constant stroke, the working posture Oite is constituted by such three leveling float 25 to perform ground leveling effect previously with respect to seedling planting places due to the planting mechanism 23.

As shown in FIGS. 3 to 7, a floating fulcrum shaft made of a pipe material which extends horizontally across the right and left planting transmission cases 22 is provided at a lower front portion of each planting transmission case 22 in the seedling planting apparatus 4. 26 is rotatably mounted around a horizontal axis P3 which is its axis. Float fulcrum shaft 26
Is a left float fulcrum shaft part 2 belonging to the left seedling planting device part 4A.
6A and a right float fulcrum shaft 26B belonging to the right seedling planting device 4B. The left and right float fulcrum shaft portions 26A, 26B are connected to the seedling planting device 4.
In the working posture (1), the connecting members 26a and 26b provided at the respective divided ends are connected so as to be integrally rotatable. Left and right float fulcrum shafts 26A,
From 26B, a plurality of swing arms 27 that swing up and down around the horizontal axis P3 with the rotation of the float fulcrum shaft 26 around the horizontal axis P3 extend rearward. At the rear end (free end) of each swing arm 27, a leveling float 2 is connected via a connection fitting 25A attached to the rear of each leveling float 25.
5 is connected so as to be able to swing up and down around the horizontal axis P4.
The leveling float 25, which is located at the center in the working posture of the seedling planting device 4, is a swinging member extending from the left end side of the right float fulcrum shaft portion 26B so as to belong to the right seedling planting device portion 4B. It is connected to the arm 27. The right float fulcrum shaft 26B swings up and down around the horizontal axis P3 with the rotation of the float fulcrum shaft 26 around the horizontal axis P3. An operation arm 28 which is extended toward the traveling body 1 is mounted. On the other hand, the right frame rod 29 which supports the upper side of the seedling mounting table 24 belonging to the right seedling planting device section 4B so as to be able to reciprocate and move laterally, faces the traveling machine 1 in the working posture of the seedling planting device 4. An operating lever 30 which is extended to be swingably operated in the left-right direction around the horizontal axis P5, and a locking member 31 for fixing and holding the operating lever 30 at an arbitrary operating position by engagement with the operating lever 30 Are provided. The operating lever 30 is linked to the operating arm 28 of the right float fulcrum shaft 26B via a linking mechanism 32 including a linking rod 32A.

With the above configuration, when the operating lever 30 is swung in the left-right direction around the horizontal axis P5 in the working posture of the seedling planting device 4, the left and right float fulcrum shaft portions 26A, 26
B rotates integrally with the horizontal axis P3 and the swing arm 2 extended from each of the float fulcrum shaft portions 26A and 26B.
7 swings up and down integrally around the horizontal axis P3, and the leveling float 25 supported by each swing arm 27 moves up and down integrally around the horizontal axis P3. That is, the height position of each leveling float 25 with respect to each planting mechanism 23 can be integrally changed by the left and right swing operation of the operation lever 30 in the working posture of the seedling planting device 4.
Is engaged and fixedly held by the locking tool 31 at an arbitrary operation position, so that each planting mechanism 23 of each leveling float 25 is
Can be set to a desired height position. The depth of planting seedlings in the field by the planting mechanisms 23 can be integrally adjusted by the above operation.

As shown in FIGS. 1 and 2, the control unit 1A
On the right side of the driver's seat 33, a planting clutch lever 34 is provided so as to be able to swing back and forth. A lever sensor S5 for detecting the operating position of the planting clutch lever 34 is provided at the swing fulcrum of the planting clutch lever 34, and the control device 13 determines that the planting clutch lever 34 has been lifted by the lever sensor S5. ”“ Neutral ”
The operation of the electromagnetic control valve 35 that switches the flow state of the hydraulic oil to the lift cylinder 3 that drives the seedling planting device 4 up and down according to each of the operation positions of “down”, “in (planting)”, and “off (planting)” In addition to the control, the operation of the planting clutch 36 for switching the transmission state to the seedling planting apparatus 4 is controlled. That is, the control device 13
Manual lifting control means 13D for controlling the raising and lowering and operation of the seedling planting device 4 based on the manually operated operating position of the planting clutch lever 34 detected by the lever sensor S5.
Is provided as a control program.

As shown in FIGS. 2 to 7, the seedling planting device 4 is provided with biasing means 37 for biasing the ground leveling float 25, which is positioned at the center in the working posture of the seedling planting device 4, to the ground.
The seedling planting device 4 in the working posture is lowered and the leveling float 2
In the planting operation state in which the ground 5 is grounded, the horizontal axis P with the change in the undulation of the field of the leveling float 25 located at the center in the center
Float sensor S6 for detecting the amount of vertical swing displacement around 4
And is equipped with. The float sensor S6 converts the detected vertical swing displacement amount of the leveling float 25 into a voltage level as a detection value and outputs the voltage level to the control device 13. The control device 13 is configured to set the reference voltage of the float sensor S6 in advance based on the voltage level (the amount of vertical swing displacement of the leveling float 25) from the float sensor S6 that fluctuates with the ups and downs of the field during the planting work. The raising and lowering of the seedling planting apparatus 4 is controlled so that the level (a control target value for defining the reference posture of the leveling float 25) and the voltage level detected by the float sensor S6 match, and the leveling float 25 is controlled. The posture is returned to a predetermined reference posture set in advance.

More specifically, the controller 13 compares, for example, a preset reference voltage level of the float sensor S6 with a voltage level from the float sensor S6, and obtains a reference voltage level from the comparison result. Leveling float 2 for a predetermined reference attitude of leveling float 25
If it is determined that the actual swinging posture of the fifth sensor 5 is in the forward rising direction, the operation of the electromagnetic control valve 35 is controlled so that the reference voltage level matches the voltage level detected by the float sensor S6, and the seedling is planted. By raising the attachment device 4,
The leveling float 25 is returned to a predetermined reference posture. In addition, a float sensor S6 set in advance
Is compared with the voltage level from the float sensor S6, and based on the comparison result, the actual swing posture of the leveling float 25 with respect to the predetermined reference position of the leveling float 25 at which the reference voltage level is obtained. Is determined to be in the forward decreasing direction, the operation of the electromagnetic control valve 35 is controlled so that the seedling planting device 4 is lowered so that the reference voltage level matches the voltage level detected by the float sensor S6. Thereby, the leveling float 25 is returned to the predetermined reference posture. That is, the control device 1
3, based on the detection value from the float sensor S6,
An automatic elevating control means 13E is provided as a control program for automatically controlling the elevating and lowering of the seedling planting apparatus 4 with respect to the traveling machine 1 so that the leveling float 25 returns to a predetermined reference posture. By the control operation of the automatic raising and lowering control means 13E, the seedling planting apparatus 4 can be maintained at a predetermined ground height regardless of the ups and downs of the field, and the planting mechanism at a predetermined predetermined seedling planting depth is set. 23 can stably plant the seedlings.

The setting of the reference voltage level of the float sensor S6 (the control target value for defining the reference attitude of the leveling float 25) is performed by manually operating a dial-type setting device 38 provided in the control section 1A. 38 guidelines are "1"
To "7". The control device 13 includes the setting device 3
By changing the ground height of the seedling planting device 4 during the planting operation based on the operation position 8, the reference posture of the leveling float 25 is changed. For example, the control device 13 raises the seedling planting device 4 so that when the setting device 38 is operated to the “1” side of the operation position, the reference posture of the leveling float 25 is changed in the forward downward direction. Has become. Conversely, when the setting device 38 is operated to the “7” side of the operation position, the seedling planting device 4 is lowered so that the reference posture of the leveling float 25 is changed to the forward rising direction. . As the reference posture of the leveling float 25 is changed in the forward and downward directions by the raising of the seedling planting device 4, the grounding bias by the biasing means 37 decreases and the grounding pressure decreases. It is easy to swing up and down. In addition, the float sensor S
6, the vertical swing displacement of the leveling float 25 can be easily detected. Conversely, as the reference posture of the leveling float 25 is changed in the forward ascending direction by the lowering of the seedling planting device 4, the grounding urging by the urging means 37 is increased and the grounding pressure is increased. It becomes difficult to swing up and down with the undulation. In addition, the float sensor S
6 makes it difficult to detect the vertical swing displacement amount of the leveling float 25.

That is, the sensitivity of the float sensor S6 is changed to the more sensitive side as the setter 38 is operated to the "1" side of the operating position, and the more the setter 38 is operated to the "7" side, the more the float sensor S6 is operated. Is changed to the insensitive side. Thereby, for example, when the mud in the field is soft, the pointer of the setting device 38 is positioned at the operation position on the “1” side corresponding to the softness, and the sensing sensitivity of the float sensor S6 is adjusted to the sensitive side. By
The seedling planting apparatus 4 can be smoothly moved up and down along the undulation of the soft mud, so that the stable planting of the seedling by the planting mechanism 23 in the soft field of mud can be realized. When the mud in the field is hard, the pointer of the setting device 38 is positioned at the operation position on the “7” side corresponding to the hardness, and the sensing sensitivity of the float sensor S6 is adjusted to the insensitive side. The float sensor S6 can detect the slight undulation of the hard mud too sensitively and prevent the seedling planting apparatus 4 from going up and down frequently, so that the planting mechanism 2 in the hard muddy field can be prevented.
3 can produce stable seedlings.

The control section 1A has a "manual" position and an "automatic" position.
When the switch 39 is set to the "manual" position, the control device 13 controls the automatic lifting and lowering control means 13E during the planting operation. The control operation is performed based on the sensitivity of the float sensor S6 set by the setting device 38. Also,
When the changeover switch 39 is set to the “automatic” position,
The control device 13 controls the automatic raising and lowering control means 13E during the planting operation based on the detection value from the torque sensor S4 of the power steering device B.

More specifically, when the steering operation at the time of headland turning or the like becomes lighter and the operating torque at the time of steering operation detected by the torque sensor S4 becomes smaller, the controller 13 sets the detected value to the detected value. Based on this, it is determined that the mud in the field has softened, and the seedling planting device 4 is raised so that the ground contact pressure of the leveling float 25 according to the mud hardness is obtained, so that the ground pressure of the leveling float 25 decreases. By changing the reference posture of the leveling float 25 in the forward descending direction, the sensitivity of the float sensor S6 is adjusted to the sensitivity on the sensitive side according to the detection value from the torque sensor S4. Further, when the steering operation at the time of headland turning and the like becomes heavy and the operating torque at the time of the steering operation detected by the torque sensor S4 increases, it is determined that the mud on the field has become hard based on the detected value. At the same time, the seedling planting apparatus 4 is lowered so that the contact pressure of the leveling float 25 according to the mud hardness is obtained, and the reference posture of the leveling float 25 in the upward direction in which the contact pressure of the leveling float 25 increases. By changing the setting, the sensitivity of the float sensor S6 is adjusted to the sensitivity on the insensitive side according to the detection value from the torque sensor S4. That is, the control device 13 includes the torque sensor S4 during the steering operation.
The automatic sensitivity adjusting means 13F for judging the hardness of the mud on the field based on the detection value from the above and automatically adjusting the sensing sensitivity of the float sensor S6 to a sensing sensitivity corresponding to the mud hardness is provided as a control program. By performing the control operation of the automatic sensitivity adjusting means 13F, the operator can determine the hardness of the field mud during the planting operation, and can set the float by the setting unit 38 every time the hardness of the field mud changes. It is possible to avoid troublesome work such as adjusting the sensitivity of the sensor S6.

[Other Examples] Hereinafter, other embodiments of the present invention will be listed. In the above embodiment, the seedling planting device 4 configured to be separable into the left seedling planting device unit 4A and the right seedling planting device unit 4B has been exemplified. The planting device unit 4A and the right seedling planting device unit 4B may be configured to be inseparable. In the above embodiment, the rice transplanter equipped with the seedling planting device 4 for eight-row planting is exemplified. However, as the seedling planting device 4, for example, for four-row planting, for five-row planting, for six-row planting, and for ten-row planting. It may be for planting or for twelve-row planting. In the above embodiment, a rice transplanter equipped with an electric power steering device B is exemplified, and the torque sensor S4 of the power steering device B is also used as the torque sensor S4 for automatic sensitivity adjustment of the float sensor S6. However, in a rice transplanter that is not equipped with the electric power steering device B, a torque sensor S4 for adjusting the automatic sensing sensitivity may be newly provided. In the above embodiment, the control means 13 (automatic sensitivity adjusting means 13F) is configured to automatically adjust the sensitivity of the float sensor S6 based on the detection value from the torque sensor S4 of the electric power steering device B. However, instead of this, the control means 13 (automatic sensitivity adjustment means 1)
3F) may be configured to automatically adjust the sensitivity of the float sensor S6 based on the engine load detected by the load detection means A. In this case, the control unit 13 (automatic sensitivity adjustment unit 13F) may be configured to adjust the sensitivity of the float sensor S6 to the insensitive side as the engine load detected by the load detection unit A increases.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a control configuration.

FIG. 3 is a plan view showing a working posture of the seedling planting device.

FIG. 4 is a plan view showing a storage posture of the seedling planting apparatus.

FIG. 5 is a rear view showing the storage posture of the seedling planting apparatus.

FIG. 6 is a side view of a main part of the seedling planting apparatus showing a configuration near a leveling float located at the center in the left and right directions.

FIG. 7 is a plan view of a main part of the seedling planting apparatus showing a configuration near a leveling float located at the center in the left and right directions.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 traveling body 4 seedling planting apparatus 5 engine 13 control means 25 leveling float 37 biasing means A load detecting means B power steering device S4 torque sensor S6 float sensor

Claims (3)

[Claims] 1. A float sensor for detecting an amount of vertical swing displacement at the time of planting a leveling float urged to touch the ground by a biasing means, and the leveling float is set to a predetermined reference based on a detection value from the float sensor. And a control means for automatically controlling the raising and lowering of the seedling planting device with respect to the traveling body so as to return to the posture. A riding type rice transplanter, comprising: a torque sensor for detecting an operating torque at the time of steering operation; A riding type rice transplanter configured such that the control means adjusts the sensitivity of the float sensor to the insensitive side as the operation torque detected by the control becomes larger. 2. The riding type rice transplanter according to claim 1, wherein a torque sensor provided in an electric power steering device is also used as the torque sensor for adjusting the sensing sensitivity. 3. A float sensor for detecting a vertical swing displacement amount at the time of planting a leveling float urged to touch the ground by an urging means, and the leveling float is set to a predetermined standard based on a detection value from the float sensor. Control means for automatically controlling the raising and lowering of the seedling planting device with respect to the traveling body so as to return to the attitude, provided with load detection means for detecting the load of the engine, and the load detection means A riding type rice transplanter wherein the control means adjusts the sensitivity of the float sensor to be less sensitive as the detected engine load increases.