JPH059042B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rice transplanter in which a planting section is attached to a traveling machine body so as to be movable up and down.

[Prior art]

Rice transplanters plant seedlings in rows at predetermined intervals, but recent rice transplanters are designed to maintain a constant planting depth regardless of the unevenness of the field. FIG. 8 schematically shows the main parts of such a rice transplanter. Usually, in a rice transplanter, the planting part is attached to the traveling machine body so that it can be raised and lowered by a lifting device, and the float 21 in the planting part is attached to the seedling planting device 37 etc. so that it can freely rotate in the vertical direction. Utilizing the vertical movement of the float 21 relative to the seedling planting device 37 due to the unevenness of the field surface, the planting section is raised and lowered based on the rotation.

That is, a rotation rod 23 extending in the left-right direction is attached to the seedling planting device 37, and the base end of a connecting rod 24 extending rearward and downward is fixed to the rotation rod 23, and the tip end thereof is fixed to the rotation rod 23. is the pin 24 at the rear of the float 21.
It is pivoted at a. Further, the base end of a first link arm 25 extending forward is fixed to the rotating rod 23, and the lower end of a second link arm 26 extending in the vertical direction is pivotally supported at the tip thereof. is,
Further, the upper end of the second link arm 26 is pivotally supported by the rear end of a third link arm 27 extending in the front-rear direction. The front end of the third link arm 27 is rotatably attached to a support shaft 28 connected to the seedling planting device 37, and the front end of the third link arm 27 is attached to the back of a link element 29 extending in the front-rear direction. The front end of the link element 29 is fitted with a connecting shaft 31 into an elongated hole 30a formed in the middle of a connecting tool 30 whose lower end is pivotally supported at the tip of the float 21. It is slidably locked. and the link element 2
One end of a wire 32 is attached to the front end of the wire 9 . Furthermore, one end of a sleeve 33 that is fitted around the wire 32 is fixed to the upper end of the connector 30 that is pivotally supported at the tip of the float 21 . sleeve 3
The other end of 3 is attached to the appropriate location on the traveling aircraft,
The other end of the wire 32 fitted into the sleeve 33 is
It extends from the other end of the sleeve 33 and is locked to a control rod 34 of a hydraulic valve 40 that controls the supply and discharge of pressure oil to and from a hydraulic cylinder for raising and lowering the planting section.

With this configuration, the float 21 is connected to pin 2.
4a, and when the tip of the float 21 is rotated upward (or downward), the sleeve 33 is pushed (or pulled) upward (or downward), and the rotation of the float 21 is The wire 32 attached to the seedling planting device 37, which does not change its position due to movement, is pulled (or pressed) relatively downward (or upward), and the operating rod 34 is rotated backward (or forward). The hydraulic valve 40 is operated, the entire planting section is raised (or lowered), and the float 21 is controlled to be in a substantially horizontal state due to the pressure from the field surface.

In the conventional rice transplanter having such a configuration, when the traveling body itself enters a front up (or front down) state, the planting section also follows the traveling machine and enters a front up (or front down) state. However, float 21
follows the field surface and is in a substantially horizontal state, so even though the float 21 is in a horizontal state, the seedling planting device 37 is in a front up (or front down) state, and the float 21 is lowered (or raised). ), the wire 32 is pressed (or pulled), the planting part is lowered (or raised), and the float 21 is therefore lowered (or raised).

The phenomenon in this case will be explained in more detail. Now, when the traveling body goes forward upward, it is positive, and when it goes forward downward, it is negative.
1 is positive when the front is upward, and negative when the front is downward, and the hydraulic valve 40 for each angle is
The operating position of is shown in the graph of FIG.

As mentioned above, the hydraulic valve 40 operates as follows.
Regardless of the longitudinal tilt of the traveling body, the float 21 is within a predetermined range (0.5° to 1°) with respect to the seedling planting device 37.
In this case, when the traveling body goes up (for example, 3 degrees) and the seedling planting device also goes up, the float 21 moves with the seedling planting device 37 in order to maintain a substantially horizontal state. The relative angle of the float 21 is the same as the tilt of the traveling aircraft (-3 degrees) (see double circle in Figure 9). For this reason, the hydraulic valve 40 operates to lower the planting section, and the planting section is lowered, but in this case, the forward tilting of the traveling body is due to rotation around the grounding point of the rear wheels. The float 21 is pressed against the rice field due to the forward tilt of the traveling body, and as the planting section descends, the float 21 is further pressed and sinks, causing the seedlings to be planted at a deeper depth, resulting in buried seedlings. do.

On the other hand, if the aircraft is tilted forward and downward,
A phenomenon opposite to the above explanation occurs, and the float is separated from the field surface, resulting in floating seedlings where the seedlings cannot be reliably planted on the field surface.

In particular, in multi-row rice transplanters, the weight of the planting section is increased, which tends to cause the above-mentioned front-up condition, and providing a control member in the planting section makes it even more difficult to plant. This increases the weight of the planting section, and there are disadvantages in that it is troublesome to attach and detach the traveling body and the planting section.

〔the purpose〕

The present invention was made in view of the above circumstances, and its purpose is to prevent the possibility of burying or floating seedlings even if the traveling body is tilted in the front-back direction, and to prevent the planting part from being buried or floating. The objective is to provide a rice transplanter that stabilizes the weight balance without adding unnecessary weight.

〔composition〕

The present invention provides a seedling planting device for planting seedlings on a rice field, and a rice transplanter in which a planting section having a float attached to the seedling planting device so as to be swingable in the vertical direction is attached to the traveling machine so as to be movable up and down. , an elevating device that controls the elevation of the planting section based on the relative swinging position between the seedling planting device and the float in the planting section; and a lifting device that operates to change the relative swinging position between the seedling planting device and the float. The apparatus comprises a position change device and a horizontal sensor that is provided at a portion whose front-back posture with respect to the horizontal changes due to the operation of the position change device and detects the front-back posture with respect to the horizontal, and based on the detection result of the horizontal sensor. The method is characterized in that the position changing device is operated.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a partially cutaway left side view of a riding rice transplanter according to the present invention. In the diagram, A is front wheel 1
4. The traveling body supported by the rear wheels 15, B is the planting part attached to the 3-point linkage mechanism 11 at the rear of the traveling body A, and the entire planting part B is raised and lowered by raising and lowering the 3-point linkage mechanism 11. be done.

The planting section B includes a seedling platform 22 attached to the upper side of the seedling planting device 37 attached to the three-point link mechanism 11 at the rear of the traveling body A, and the seedling planting device 7
It consists of three floats 21 attached to the lower side of the float so as to be swingable in the vertical direction.

FIG. 2 is a plan view of the center and left floats 21;
Figure 3 is a schematic front view of the central float 21;
The figure is a schematic diagram of the main parts of the machine of the present invention shown together with a side view thereof. Each float 21 is attached to one rotating rod 23 that is pivotally supported at the bottom of the seedling planting device 37 and extends in the left-right direction. That is, the base end portions of a pair of left and right connecting rods 24 extending rearward and downward are fixed to the center, left, and right sides of the rotation rod 23, and the tip portions of the connecting rods 24 are attached to pins 24a on the upper surface of each float 21. It is rotatably mounted. Accordingly, each float 21 is raised and lowered relative to the seedling planting device 37 by the rotation of the turning rod 23, and the planting depth of the seedlings is changed and adjusted. A base end portion of an adjustment lever 38 extending forward and upward is fixed to a portion of the rotating rod 23 corresponding to between the center float 21 and the left float 21, and by rotating the adjusting lever 38, the rotating rod 23 is rotated, and all the floats 21 are raised and lowered relative to the seedling planting device 37.

A base end of a first link arm 25 extending forward is fixed to the left side of the center of the rotation rod 23, and a second link arm 26 extending vertically is attached to the distal end of the first link arm 25. The lower end of the second link arm 26 is pivotally supported, and the upper end of the second link arm 26 is pivotally supported by the rear end of a third link arm 27 extending in the front-rear direction.

The left end of a support shaft 28 that extends in the left-right direction and is integrally attached to the seedling planting device 37 is rotatably attached to the front end of the third link arm 27. The rear end portions of a pair of left and right link elements 29, which are integral with the third link arm 27 extending in the front-rear direction, are rotatably attached to 28. The front end of each link element 29 is pivotally supported by the left and right ends of a single connecting shaft 31 extending in the left-right direction.
Reference numeral 1 denotes a long hole 30a extending in the vertical direction, which is formed in each left and right side of a connector 30, which has a downward U-shape when viewed from the front, and whose left and right lower ends are pivotally supported on the front upper surface of the float 21. is slidably engaged with. Further, one end of a wire 32 is locked to the left-right center portion of the connecting shaft 31, and the wire 32 is connected to the connecting tool 3.
0, and extends to the traveling body A through a sleeve 33 fixed at one end to the upper part of the connector 30.

With such a configuration, the float 21 is connected to the seedling planting device 3.
7, the sleeve 33 fixed to the connector 30 is pressed or pulled when the front part rotates upward or downward. Since the connecting shaft 31 engaged with the elongated hole 30a of the connecting tool 30 is connected to the seedling planting device 37, its position is not changed, so that the wire 32 fitted inside the sleeve 33 is relatively downward. or pulled or pushed upward.

The other end of the wire 32 passes through the upper center of the connector 30, is fitted into the sleeve 33, and is connected to the traveling aircraft body A.
3 at the rear of traveling aircraft A.
It is locked to the upper end of a control rod 34 of a hydraulic valve 40 that controls the supply and discharge of pressure oil to and from a hydraulic cylinder that raises and lowers the point linkage mechanism 11. control rod 34
is arranged so that the middle protrusion 34a is in contact with the spool 41 of the hydraulic valve 40, and the protrusion 34a
A slightly lower portion is rotatably supported by a pin 35. The spool 41 of the hydraulic valve 40 is moved in the direction in which the spool 41 advances (three-point linkage mechanism 1
1), and a tension spring 36 is attached to the lower end of the control rod 34, so that the control rod 34 is moved by the tensile force of the wire 32. The lower end of the control rod 34 is urged in a direction opposite to the direction in which it is rotated. The three-point link mechanism 11 of the hydraulic valve 40 is configured to move downward when the spool 41 advances, and rise when the spool 41 moves backward.

On the other hand, the wire 3 is placed at a suitable location in the traveling body A.
A sleeve position changing mechanism 50 for changing the relative position of the sleeve 33 with respect to the sleeve 33 is provided.

This sleeve position changing mechanism will be explained below. The upper end of an L-shaped seat 55 is pivotally supported at the end of the sleeve 33 on the side of the traveling machine body A. catch seat 5
5 has a bent portion pivotally supported at an appropriate position on the traveling body A, and consists of a portion extending upward from the bent portion and a portion extending rearward, and the upper end portion of the connecting link 54 is pivotally supported at the rear end. ing. The lower end of the connecting link 54 is pivotally supported by the front end of the mounting arm 53. The mounting arm 53 has a mounting portion 5 extending in the front-rear direction.
3a, and a driving part 53b extending downward from the rear end of the mounting part 53a, and pivotally supports the upper part of the driving part 53b in an appropriate position in the fuselage. and mounting part 5
A horizontal sensor 60, which will be described later, is attached to the upper surface of 3a.

The lower end of the drive portion 53b is pivotally supported by a block body 52, which has a screw thread 51 formed with a thread groove on its outer periphery and arranged so that its axial direction coincides with the moving direction of the wire 32. It is screwed onto the outside. The screw rod 51 is rotatably supported by a bracket 56 attached at a suitable position on the body, and the output shaft of a motor 57 is connected to one end of the bracket 56.

Therefore, by normal rotation (or reverse rotation) of the motor 57, the block body 52 is moved forward as shown by the solid line (or broken line) in FIG. connected link 54
moves upward (or downward), the seat 55 is rotated, and the sleeve 33 is pulled (or pushed) forward (or backward). Mounting part 53a of mounting arm 53
is horizontal when the block body 52 is located at the center of the screw rod 51 in the axial direction. On the bracket 56 to which the screw rod 51 is attached, normally closed limit switches 58 and 59, whose operating rods face the movement range of the block body 52, are arranged at rear and forward movement limit positions of the block body 52, respectively.

FIG. 5 is a longitudinal sectional view of the horizontal sensor 60. The horizontal sensor 60 has a support shaft 62 installed in the left-right direction inside the casing 61, and a fan-shaped light shielding plate 63 hanging rotatably from the center of the support shaft 62. Light emitting diodes 64 and 65 are arranged at an appropriate length apart in the front-rear direction. Phototransistors 66 and 67 are disposed on the right side of the casing 61 at front and rear positions facing each light emitting diode 64 and 65, respectively, and when the horizontal sensor 60 is in a horizontal state, each light emitting diode 64 , 65 is received by each phototransistor 66, 67 and turned on, and when the horizontal sensor 60 tilts forward downward (or forward upward), the casing 61 also tilts forward downward (or forward upward). However, since the light shielding plate 63 is vertical, the light emitted from the front (or rear) light emitting diode 64 (or 65) is blocked by the light shielding plate 63, and the phototransistor 6
6 (or 67) turns off.

FIG. 6 shows the electrical circuit of the present invention. In the figure, 71 is a battery whose negative electrode is connected to body ground, and its normal state is connected to one end of a key switch 72. It is connected to a common terminal 74d of a changeover switch 74 via a planting switch 73 that is turned on and off in conjunction with engagement and disengagement. The changeover switch 74 has three changeover terminals, and one of the terminals 74a changes the rotational state of the seedling planting device 37 and the float 21 in the planting section B, that is, the above-mentioned motor 57 to the detection result of the horizontal sensor 60. When automatically controlling based on the common terminal 74d
The other two terminals 74b and 74c are terminals that are connected to the common terminal 74d when the motor 57 is directly controlled by manual operation. The terminal 74c is connected when the motor 57 is rotated in the reverse direction.

The switching terminal 74a of the changeover switch 74 is connected to the constant voltage circuit 75, and is also connected to the excitation coil 81C of the electromagnetic relay 81 via the normally closed limit switch 59 and the switch transistor 77, and is further connected to the normally closed limit switch 58 and the excitation coil 81C of the electromagnetic relay 81. It is connected to the excitation coil 82C of the electromagnetic relay 82 via the switch transistor 79.

The output of the constant voltage circuit 75 is applied to a series circuit of light emitting diodes 64 and 65 arranged in a horizontal sensor 60 interposed between the resistor and body ground, and is also applied to a switch via a phototransistor 66 and a resistor. The signal is applied to a transistor 76, and is further applied to a switch transistor 78 via a phototransistor 67 and a resistor.

Light emitting diode 64 in horizontal sensor 60
The light emitted from the phototransistor 66 (or 67) is received by the phototransistor 66 (or 67).
is turned on by receiving the light, and turned off when the light shielding plate 63 blocks the light. The output of phototransistor 66 (or 67) is applied to the base of switch transistor 76 (or 78). The collector of the switch transistor 76 (or 78) is connected to the limit switch 59 (or 58) and the electromagnetic relay 81.
(or 82) is connected to the base of a switch transistor 77 (or 79) interposed between the excitation coil 81C (or 82C), and when the phototransistor 66 (or 67) is turned on, the switch transistor 76 (or 78) is turned on, and the switch transistor 77 (or 79) is turned off.
Conversely, when the phototransistor 66 (or 67) is turned off, the switch transistor 76 (or 78) is turned off.
turns off, switch transistor 77 (or 79) turns on, and excitation coil 81C (or 82C)
is excited.

The electromagnetic relay 81 has a normally open contact 81a and a normally closed contact 8.
1b, and the normally open contact 81a is connected to the aforementioned motor 57.
The normally closed contact 81b is interposed between one terminal of the motor 57 (the terminal connected to the battery when rotating the motor 57 in the forward direction) and the planting switch 73, and the normally closed contact 81b is connected between the terminal of the motor 57 and body ground. is interposed in.

Similarly, the electromagnetic relay 82 has a normally open contact 82a and a normally closed contact 82b, and the normally open contact 82a is connected to the other terminal of the motor 57 (the terminal connected to the battery when reversing the motor 57). It is interposed between the attached switch 73 and the normally closed contact 82.
b is interposed between the same terminal of the motor 57 and body ground.

Therefore, the normally open contact 81 is energized by the excitation coil 81C (or 82C) of the electromagnetic relay 81 (or 82).
a (or 82a) is a closed circuit, normally closed contact 81b (or 8
2b) is opened and the motor 57 rotates forward (or reverse)
do.

In the machine of the present invention having such a configuration, the raising and lowering of the planting section is controlled as follows. When the planting section B is lowered so that its float 21 touches the rice field surface and the traveling body A is made to travel forward, the seedling planting device 37 of the planting section B is driven to perform the planting work. The aircraft A runs on the plowing platform, and the float 21 slides on the rice field.

Now, when the traveling aircraft A is in a substantially horizontal state,
When the float 21 follows the unevenness on the rice field and its front part moves upward (or downward), the float 2
The sleeve 33 attached to the first connector 30 is pushed (or pulled) upward (or downward), and the wire 32 fitted within the sleeve 33 is pulled (or pushed) downward (or upward). , control rod 3
4 is rotated backward (or forward) to open the hydraulic valve 4.
The spool 41 of 0 moves back (or moves forward), the three-point linkage mechanism 11 rises (or falls), the entire planting section B rises (or falls), and the float 21 also rises (or falls). The front portion of the float 21 is lowered (or raised) relative to the seedling planting device 37, and the float 21 is returned to a substantially horizontal state. float 2
As the front part of 1 lowers (or rises), the sleeve 3
3 is pulled (or pushed) downward (or upward),
The wire 32 is relatively pushed (or pulled) upward (or downward) and the spool 4 of the hydraulic valve 40
1 advances (or retreats), and when the float 21 becomes approximately horizontal, the hydraulic valve 40 becomes neutral and the raising and lowering of the planting section B is stopped.

When the traveling machine A is tilted forward downward (or forward upward) due to unevenness of the tiller, etc., the light emitting diode 64 provided on the front side of the horizontal sensor 60
(or 65) is blocked by the light shielding plate 63, and the light emitted from the phototransistor 66 (or 65) is blocked by the light shielding plate 63.
7) is turned off, and as a result, the excitation coil 81C (or 82C) of the electromagnetic relay 81 (or 82) is excited.
The motor 57 is rotated forward (or reversed). As a result, the screw rod 51 is rotated forward (or reversed), and the screw rod 51 is rotated forward (or reversely).
1 is moved in the direction of the solid line (or broken line) in the direction of the white arrow in FIG. The sleeve 53 is moved forward (or backward).

On the other hand, when the traveling body A is tilted forward down (or front up), the entire planting section B is also tilted forward down (or front up), but the float 2
1 maintains a substantially horizontal state because it is in contact with the field surface, and the connecting shaft 31 at the tip of the link element 29 attached to the front part of the float 21 and the seedling planting device 37
(Therefore, the lower end of the wire 32) is close to (or apart from)
The power works to do so. However, as mentioned above,
Since the sleeve 33 moves forward (or backward) as the traveling body A tilts, the sleeve 33 moves backward as the seedling planting device in the planting section B tilts with respect to the float 21. No pulling (or pressing) force is applied to the wire 32 fitted therein, so the hydraulic valve 40 is not operated and the wire 32 is not raised or lowered into the planting section B. That is, as the traveling body A tilts, the rotation angle of the float 21 with respect to the seedling planting device 37 becomes smaller (or larger), and therefore the distance between the lower end of the sleeve 33 and the lower end of the wire 32 becomes larger (or smaller). No force is applied to wire 30 and control rod 34 is not operated.

The mounting arm 53 is rotated as the block body 52 is moved by the rotation of the motor 57, and when the mounting portion of the mounting arm 53 is in a substantially horizontal state, the light emitted from the light emitting diode 64 (or 65) of the horizontal sensor 60 is Phototransistor 66 (or 67)
The phototransistor 66 (or 67) is turned on, the excitation coil 81C (or 82C) of the electromagnetic relay 81 (or 82) is demagnetized, and the rotation of the motor 57 is stopped.

Therefore, while the traveling body is tilted forward down (or forward up), the rotation angle of the float 21 relative to the seedling planting device 37 in the planting section B is reduced (or increased) to perform the planting work. . Even during such work, if the float 21 is not level and a force acts on the float 21 from the field surface, the vertical swing of the float 21 presses and pulls the wire 32, causing the entire planting section B to descend. , and the float 21 is brought into a substantially horizontal state.

FIG. 7 shows the relationship between the longitudinal tilt angle of the traveling body A with respect to the horizontal, the rotation angle of the float 21 with respect to the seedling planting device 37, and the operating state of the hydraulic valve 40.

In the figure, when the traveling body A is tilted forward upward, it is positive, when it is tilted forward downward, it is negative, and when the float 21 rotates forward upward relative to the seedling planting device 37, it is positive, and forward downward. The case of rotation is defined as negative, and the range of the rotation angle of the float 21 relative to the seedling planting device 37 in which the hydraulic valve 40 operates changes in accordance with the tilt angle of the traveling body A. As is clear from this figure, when the traveling body A is in a horizontal state, when the float 21 rotates outside the dead zone (0.5° to -1°) with respect to the seedling planting device 37, the hydraulic valve 40 is activated. However, when the traveling body A is tilted forward by 3 degrees, the sleeve position changing mechanism 50 is driven, and the float 21 is rotated by −3 degrees forward and downward relative to the seedling planting device 37 in the planting section B. It will be done. In such a state, the float 21 is connected to the seedling planting device 37.
Rotation of 0.5° to -1° or more with respect to the seedling planting device 3
The hydraulic valve 40 will not operate unless the rotation angle of the float relative to 7 is -25° to -4° or more (see double circle in Figure 7), and therefore the planting part B will not descend and the float 21 will not move. The planting operation is performed in a state where the seedling planting device 37 is rotated by −3° (approximately horizontal with respect to the field surface), and the float 21 does not sink. In other words, the relative angle between the seedling planting device 37 and the float 21, which is a dead zone for the control of the hydraulic valve 40, changes with the tilt angle of the traveling machine in the front-back direction. The dead zone is changed in accordance with the tilting of the traveling aircraft.

〔effect〕

According to the present invention, since the planting section is controlled to rise and fall based on the vertical movement of the float relative to the seedling planting device in order to keep the planting depth constant, the seedlings are raised relative to the field surface. The implantation device is always located at a constant height. In addition, when the traveling body is tilted in the front-back direction, the rotation angle of the float relative to the seedling planting device in the planting section is changed.
There is no risk that the float will sink into the rice field or float above the rice field even when the machine body is tilted in the front and rear directions, and this will not cause buried or floating seedlings. Furthermore, in the present invention, since the horizontal sensor is attached to the connecting member that is tilted forward and backward with respect to the horizontal direction by the movement of the block body, there is no need to detect the tilt angle of the body forward and backward in an analog manner, and the control circuit It becomes possible to simplify.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway left side view of the inventive machine, Fig. 2 is a plan view of the float in the planting section, Fig. 3 is a front view of its main parts, and Fig. 4 is the invention shown together with the side surface of the float. Fig. 5 is a schematic diagram of the main parts of the machine, Fig. 5 is a vertical cross-sectional view of the horizontal sensor, Fig. 6 is an electrical circuit diagram of the main parts of the machine of the present invention, and Fig. 7 is the longitudinal tilt angle of the traveling machine with respect to the horizontal and the seedling planting device. Graph showing the relationship between the tilting angle of the float and the operation of the hydraulic valve, No. 8
The figure is a schematic diagram of the main parts of a conventional rice transplanter, and FIG. 9 is a graph for explaining the operation of the conventional rice transplanter. A... Traveling body, B... Planting section, 11... Three-point link mechanism, 13... Horizontal sensor, 21... Float, 32
...Wire, 33...Sleeve, 34...Control rod, 37
... Seedling planting device, 40... Hydraulic valve, 50... Sleeve position changing mechanism, 51... Screw rod, 52... Block body,
53...Mounting arm, 55...Catch, 57...Motor,
60... Horizontal sensor, 63... Light shielding plate.

Claims (1)

[Claims] 1. A seedling planting device for planting seedlings on a rice field, and a rice transplanter in which a planting part having a float attached to the seedling planting device so as to be able to swing vertically is attached to the traveling machine so as to be able to move up and down. A lifting device that controls the raising and lowering of the planting section based on the relative swinging position between the seedling planting device and the float in the attached section; and a position changing device that operates to change the relative swinging position between the seedling planting device and the float. and a horizontal sensor that is provided at a portion whose longitudinal orientation with respect to the horizontal changes due to the operation of the position changing device and detects the longitudinal orientation with respect to the horizontal, and the position is changed based on the detection result of the horizontal sensor. A rice transplanter characterized by operating a device.