JP2002209412A - Paddy field working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the oil pressure sensitivity of a float to be controlled depending on the change of the revolution of an engine and the running speed of a machine body, and improve the followability to the surface of a field. SOLUTION: A riding-type rice transplanter 10 has the following construction: the posture of a transplanting part 24 vertically moved and supported by an oil hydraulic cylinder 30 is perceived by the buoyancy acting upon a float 27; and an oil pressure controlling valve 32 for controlling the cylinder 30 is linked to the float 27 via a cooperation mechanism 35 to control the valve 32 by the change of the posture of the float 27. The cooperation mechanism 35 has an oil pressure sensitivity-controlling lever 31 which can control the oil pressure sensitivity of the float 27. The lever 31 is linked to an engine throttle lever 20 and a main speed-changing lever 23 so that the oil pressure sensitivity of the float 27 can be changed according to the change of the revolution of the engine and the running speed of the machine body, and the followability of the float 27 to the surface of an field is not damaged even on the speeding up of working.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paddy field working machine such as a riding rice transplanter, and more particularly, to a lifting / lowering control of a working section via a hydraulic control valve based on a buoyancy acting on a grounding body, thereby enabling a proper transplanting operation. Rice field work machine.

[0002]

2. Description of the Related Art A transplanting machine such as a riding rice transplanter is provided with an elevating control lever which can be operated manually and automatically. The operating position of the planting section is controlled by manual operation of the lever, and the automatic position of the lever is controlled. In, the buoyancy (earth pressure, water pressure, etc.) acting on the float of the planting section is sensed, and automatic elevation control is performed by hydraulic pressure so that the planting section is at an appropriate planting position.

[0003] When the mud in the field is soft, the front part of the float generally falls down and penetrates into the soil to cause mud pushing, so that the planting portion sinks and the planting depth becomes too deep. On the other hand, when the mud in the field scene is hard, the front part of the float rises and the planting part floats up and the planting depth becomes shallow, and the rock tends to be frequently swung up and down due to the soil mass and the like.

[0004] As a means for solving this, for example, when the mud is soft, the urging force for urging the float in the direction of the field scene is reduced so that the float can move upward even with a slight buoyancy, and the float can be moved with sharp sensitivity. The vertical movement can be controlled, and when the mud is hard, the urging force is increased to increase the float's upward movement resistance, and the float is moved up and down with a low sensitivity so that the float will not move unless it has a large buoyancy. For example, there is a method in which the sensing load of the float is changed by changing the magnitude thereof, such as by controlling the movement.

[0005] For example, Japanese Patent Application Laid-Open No.
As described in JP-A-1-113332, a hydraulic control valve is connected to a throttle lever via a return spring and a sensitivity adjusting lever, and the sensitivity adjusting lever is connected to a float. When the sensitivity is increased, the return load increases the perceived load of the float, and the vertical position of the front part of the float can be changed by operating the sensitivity adjustment lever. As a result, even when the vehicle traveling speed increases, the float is prevented from floating on the rice field, thereby preventing the occurrence of floating seedlings.

[0006]

By the way, in order to prevent the float from rising above the rice field when the running speed of the airframe increases, generally, a method of increasing the load perceived by the float and a method of increasing the float attitude are described. There are two ways to change the hydraulic control valve to make it easier to operate in the downward direction. However, according to the conventional technology, the hydraulic control valve and the sensitivity adjusting lever are linked to the throttle lever, so that the work speed is increased. It was difficult to respond.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to adjust the oil pressure sensitivity of a ground contact body in accordance with a change in an engine speed and a body running speed. An object of the present invention is to provide a paddy working machine capable of stabilizing and improving work accuracy without impairing the ability of a grounded body to follow a rice field surface.

[0008]

According to one aspect of the present invention, there is provided a hydraulic cylinder device (30).
, The working unit (24) supported by the traveling body (15) so as to be able to move up and down is sensed by the buoyancy acting on the grounding body (27) that moves while being grounded on the field scene, and the hydraulic cylinder device (30) ) Is controlled by a hydraulic control valve (32) via a connecting mechanism (35).
7) controlling the hydraulic control valve (32) based on the buoyancy acting on the grounding body (27) to control the hydraulic cylinder device (30) to raise and lower the working unit (24). In the paddy field working machine (10) for transplanting seedlings to a field, the connecting mechanism (35) has a hydraulic sensitivity adjusting means (31) capable of adjusting the hydraulic sensitivity of the grounding body (27). Engine speed adjusting means (20) for adjusting the engine speed in the sensitivity adjusting means (31)
And speed change operation means (23) for adjusting the vehicle running speed, and the hydraulic sensitivity is adjusted based on operation of at least one of the engine speed adjustment means (20) and the speed change operation means (23). It is made possible.

According to a second aspect of the present invention, the amount of adjustment of the oil pressure sensitivity of the grounding body (27) based on the operation of the speed change operating means (23) is controlled based on the operation of the engine speed adjusting means (20). The hydraulic pressure sensitivity of the ground contact body (27) is larger than the adjustment amount.

The invention according to claim 3 is characterized in that the adjustment of the hydraulic sensitivity is performed by adjusting the posture of the grounding body (27).

According to the present invention, the connecting mechanism (3) for connecting the hydraulic control valve (32) to the grounding body (27).
5) has a hydraulic sensitivity adjusting means (31) capable of adjusting the hydraulic sensitivity of the grounding body (27).
By linking the engine speed adjusting means (20) and the speed change operating means (23) to 1), at least one of the engine speed adjusting means (20) and the speed change operating means (23) can be operated. For example, the hydraulic sensitivity of the grounding body (27) can be adjusted. For this reason, the hydraulic sensitivity of the grounding body (27) is adjusted according to changes in the engine speed and the body running speed, and the grounding body (27) follows the rice field surface even when the work speed is increased. The working accuracy can be stabilized and improved without impairing the workability.

Note that the reference numerals in parentheses described above are for reference to the drawings, and do not limit the present invention in any way.

[0013]

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

FIG. 1 is an overall side view of a riding rice transplanter to which the present invention is applied. As shown in FIG.
Is the traveling body 1 supported by the front wheels 12 and the rear wheels 14.
The traveling body 15 has an engine 1 at the front.
6, a transmission 17 is mounted on the rear part thereof, and a driver's seat 19 having a seat 18 is disposed substantially at an intermediate position between the front and rear wheels 12, 14. The driver's seat 19 includes a steering wheel 21, a main shift lever 23 for switching between forward and rearward movements to the side, an engine throttle lever 20 (see FIG. 2) for controlling an aircraft traveling speed on an operation panel portion, and a seat 18. A planting clutch lever (oil pressure / planting lever) 22 (see FIG. 2) for engaging and disengaging the planting clutch is provided on the right side, and a hydraulic sensitivity adjusting lever 31 is provided on the left side.

Behind the traveling body 15, a planting part 24 as a working part is provided with an upper link 25 a and a lower link 2.
5b is supported by a lifting link mechanism 25 having a lifting mechanism 5b. The planting portion 24 has a large number of planting rods 26, a float 27 as a grounding body, and a seedling mounting table 28 on which mat seedlings can be placed. Is provided. In addition, this planting part 24
Can be rolled freely by a rolling shaft (not shown) installed on a link support frame 29 at the rear end of the lifting link mechanism 25.

A hydraulic cylinder 30 is disposed between the rear portion of the front axle supporting the front wheels 12 and the elevating link mechanism 25.
Is a hydraulic control valve 32 disposed below the driver's seat 19.
The planting section 24 is controlled to move up and down by expanding and contracting based on the operation of.

For example, in FIG. 2, by manually operating the planting clutch lever 22 to each of the "up", "fixed", "down", and "planting" positions along a guide groove (not shown), the hydraulic pressure is increased. The cam 34 rotates around a cam shaft (not shown), and the hydraulic control valve 32 composed of a rotary pool valve is rotationally controlled, so that the planting section 24 is controlled to move up and down.
Further, the hydraulic control valve 32 has an arm 33 attached to a shaft 32 a integral with the spool. The arm 33 is connected to the float 27 via a linking mechanism 35, and In the "automatic" position, the hydraulic control valve 32 is automatically controlled based on fluctuations in buoyancy such as earth pressure and water pressure acting on the float 27, the hydraulic cylinder 30 expands and contracts, and the planting section 24 automatically moves up and down. Is done.

The float 27 has a rear portion pivotally mounted on a shaft 37 provided at a lower portion of a transmission case 36, and a sensing plate 38 is pivotally mounted at a front portion thereof.
Are linked. As shown in FIG. 2, the sensing plate 38 has a lower end pivotally supported on the float 27 by a connecting pin 39, and a long hole 38a formed near the upper end thereof. A float sensitivity adjusting wire 40 is connected to an upper end portion of the sensing plate 38.
A pin 41 fixed to the 0 inner wire 40a is fitted into the long hole 38a.

Here, in this embodiment, the connecting mechanism 35 has a hydraulic sensitivity adjusting means 31 capable of adjusting the hydraulic sensitivity of the grounding body 27, and the hydraulic sensitivity adjusting means 31 adjusts the engine speed. The engine speed adjusting means for adjusting the vehicle speed and the speed change operating means 23 for adjusting the running speed of the vehicle are linked.

In FIG. 2, the linking mechanism 35 has a hydraulic sensitivity adjusting lever (hydraulic sensitivity adjusting means) 31 capable of adjusting the hydraulic sensitivity of the float 27, and has the above-described sensing plate 38 and the swinging motion of the sensing plate 38. Moving arm 4
And a hydraulic control valve 32 connected to the sensing rod 43 via a link ratio adjuster 44.
And a continuous traction link 45 connected to the vehicle. The continuous traction link 45 is connected to the hydraulic sensitivity adjustment lever 31 via a return spring 46 and a valve interlocking wire 47. The hydraulic sensitivity adjustment lever 31 is connected to the float sensitivity adjustment wire 40 via a connector 75. Is connected.
The biasing pressure of the return spring 46 can be adjusted by operating the hydraulic sensitivity adjustment lever 31. Also,
A sensing spring 53 is stretched between the swing arm 42 and the sensing rod 43.

The swing arm 42 is a bifurcated arm 42a, 4 which can swing integrally about a pivot 57.
2b, and the arms 42a and 42b are connected to the lower link 2 disposed on the left and right sides of the body at the rear of the lifting link mechanism 25.
It is arranged close to a connecting shaft 58 connecting the 5b and 25b.

The sensing plate 38 and one arm 42
a is connected via a pin 41 fitted into a long hole 38a of the sensing plate 38, and the arm 42a is
It is curved in an arc shape so as not to contact the connection shaft 58. The sensing rod 43 is connected to the tip of the other arm 42b via a pin 60.

That is, the tip of one arm 42a of the swing arm 42 is connected to the sensing plate 38 via the pin 41, and the tip of the other arm 42b is
The connecting rods 41 and 60 are connected to the sensing rod 43 via a pin 60, and are disposed substantially vertically apart from the connecting shaft 58.

On the other hand, a float sensitivity adjusting wire 40 is connected to a pin 41 connecting the swing arm 42a and the sensing plate 38, and a spring is connected between the wire connecting pin 41 and the float connecting pin 39. A spring 61 stretches the inner wire 40a to position and set the working length of the sensing plate 38, which is the length between the wire connecting pin 41 and the float connecting pin 39.

Next, the sensing rod 43 has an elongated rod member extending in the longitudinal direction, a link fitting 62 is integrally attached to a rear portion of the rod member, and a pin joint is attached to a front portion. The part 63 is attached. The link fitting 62 has a pin 62a planted near the center on one side and an elongated hole 62b formed at the other end. A pin 60 fixed to the tip of the swing arm 42b is fitted into the elongated hole 62b, and a sensing spring 53 is stretched between the pin 60 and the pin 62a.

The link ratio adjusting section 44 includes a sensing rod 4
A conversion lever 64 for connecting the link 3 and the continuous traction link 45 is provided. A pivoting end of the conversion lever 64 and a pin joint 63 of the sensing rod 43 are pivotally mounted on the pin 65 by a pin 65. . The base end of the conversion lever 64 is rotatably mounted on the lower link 25b by a pivot connecting portion 66. A plurality of holes are formed in the conversion lever 64 along the longitudinal direction thereof.
7, one end of the continuous traction link 45 is attached. The insertion position of the pin 67 can be freely changed by insertion and extraction.

The other end of the link 45 is connected to the arm 33 of the hydraulic control valve 32 via the pin 68 as described above. Further, a pin 69 is implanted in an intermediate portion of the continuous traction link 45, and a return spring 46 is stretched on the pin 69, and the continuous traction link 45 is always lowered by the return spring 46. Biased in the direction.

In the above, the oil pressure sensitivity adjusting lever 31 is connected to the engine throttle lever (engine speed adjusting means) 20 for adjusting the engine speed by the wire 71 via the connecting member 75 and the body running speed by the wire 73. A main shift lever (shift operation means) 23 to be adjusted is linked. Further, the connecting member 75 is connected to the float sensitivity adjusting wire 40, so that the hydraulic sensitivity of the float 27 can be adjusted based on the operation of at least one of the engine throttle lever 20 and the main shift lever 23. Has become.

That is, as shown in FIGS. 3 to 5A and 5B, the hydraulic sensitivity adjusting lever 31 has a horizontal shaft 31b above a bracket 31a having a substantially U-shaped lower end. A substantially L-shaped lever arm 31 'is fixed, and the bracket 31a and the lever arm 31' swing back and forth about a shaft 31c.
The connecting member 75 includes a hook-shaped plate 75a fixed to the bracket 31a and a U-shaped plate 7 inside the hook-shaped plate 75a.
5b and an L-shaped plate 75c, and these plates 75b and 75c are provided so as to be movable in the extending direction of the wires 40, 71 and 73. The hydraulic sensitivity adjusting lever 31 and the connecting member 75 are configured such that the horizontal shaft 31b of the lever arm 31 'is rotatably mounted on the hook-shaped plate 75a, and the horizontal shaft 31b has a U-shaped free end. The protruding side of the shaft 77, which is slidably fitted into the long hole 76 of the plate 75b,
It is slidably fitted in the elongated hole 78 of the shaped plate 75c.

An inner wire 40a of the float sensitivity adjusting wire 40 is fixed to the U-shaped plate 75b.
The inner wire of the wire 71 is fixed to the shaft 77 provided horizontally on the U-shaped plate 75b, and the inner wire of the wire 73 is fixed to the L-shaped plate 75c. Although not shown, the lever arm 31 ′
The inner wire of the valve interlocking wire 47 is fixed to the horizontal shaft 31b.

For this reason, when the hydraulic sensitivity adjustment lever 31 is swung in the direction of arrow A in FIG. 5A about, for example, the shaft 31c, the float sensitivity adjustment wire 40 is pulled and moved in the same direction. The valve interlocking wire 47 is relaxed and moves in the same direction. Further, from this state, when the engine throttle lever 20 is operated to pull the inner wire of the wire 71 in the direction of arrow C, the float sensitivity adjusting wire 40 is pulled in the same direction, and the shaft disposed horizontally on the U-shaped plate 75b. The reference numeral 77 moves to the position where it slides in the elongated hole 78. At this time, the hydraulic sensitivity adjustment lever 3
The one horizontal shaft 31b slides in the long hole 76 and stops at an intermediate position.

Next, from this state, the main transmission lever 23
Is operated to pull the inner wire of the wire 73 in the direction of arrow C, the L-shaped plate 75c moves in the same direction, and the protruding portion of the shaft 77 laid sideways on the U-shaped plate 75b slides in the elongated hole 78. Move to the position where the
Abut on the end. Subsequently, when the inner wire of the wire 73 is further pulled, both the L-shaped plate 75c and the U-shaped plate 75b move in the same direction, the float sensitivity adjustment wire 40 is pulled in the same direction, and the hydraulic sensitivity adjustment lever 31 The horizontal shaft 31b slides in the long hole 76 of the U-shaped plate 75b and stops at the position of the end.

Therefore, for example, when the engine throttle lever 20 is operated to the low rotation speed side, the float sensitivity adjusting wire 40 is tensioned via the connecting member 75, and the float 27 is adjusted to the forward descending posture (sensitive). Hydraulic sensitivity). Further, when the engine throttle lever 20 is operated toward the high rotation speed side, the float sensitivity adjusting wire 40 is relaxed via the connecting member 75, and the float 27 is adjusted to the forward-upward posture (insensitive hydraulic sensitivity).

Similarly, when the main transmission lever 23 is operated to the low-speed running side, the float sensitivity adjusting wire 40 is tensioned via the connecting member 75, and the float 27 is adjusted to the forward descending posture (sensitive hydraulic sensitivity is obtained). ). Also, the main shift lever 2
When the operator moves the float 3 toward the high-speed running side, the float sensitivity adjusting wire 40 is relaxed via the connecting member 75, and the float 27 is adjusted to the front-up position (insensitive hydraulic sensitivity).

FIGS. 6A and 6B are views showing the float posture at this time. That is, when the main transmission lever 23 is operated to the high-speed running side or the engine throttle lever 20 is operated to the high rotation speed side, the float 27 is adjusted to the forward ascending posture (see FIG. 6A). When the main transmission lever 23 is operated to the low speed running side or the engine throttle lever 20 is operated to the low rotation speed side, the float 27 is adjusted to the forward descending posture (see FIG. 6B).

When the hydraulic pressure sensitivity adjusting lever 31 is operated, the connecting member 75 is moved back and forth accordingly, and the float sensitivity adjusting wire 40 is operated. That is, for example,
When the hydraulic sensitivity adjusting lever 31 is tilted in the direction B about the shaft 31c, the connecting member 75 is slid in the same direction, the float sensitivity adjusting wire 40 is relaxed, and the valve interlocking wire 47 is pulled. An urging force acts in a direction of pressing the rear portion of the float 27 downward through the continuous traction link 45 or the like. Therefore, the float 27 is adjusted to the forward-upward posture, and the sense load acting on the float 27 increases.

When the hydraulic pressure sensitivity adjusting lever 31 is tilted in the direction A, an urging force acts in the direction opposite to the above, so that the float 27 is adjusted to the forward descending posture, and the sense load acting on the float 27 is adjusted. Decreases. Thus, the operation of the hydraulic sensitivity adjustment lever 31 changes the sensing load and the float posture of the float 27.

By the way, in general, when the traveling speed of the airframe increases, the front part of the float 27 is raised with respect to the rice field, so that floating seedlings are generated. To solve this problem, it is necessary to adjust the hydraulic sensitivity. Performed by In this case, the oil pressure sensitivity increases the sensing load of the float 27 and increases the float 2
A method of adjusting the load to suppress the rise of the float 7 and a method of adjusting the float posture to change the posture of the float 27 so that the hydraulic control valve 32 can easily work in the downward direction can be considered. In the present embodiment, It was decided to adjust the float posture as the hydraulic sensitivity.

In this embodiment, the main shift lever 2
The amount of adjustment of the hydraulic sensitivity of the float 27 based on the operation 3 is
The adjustment amount of the hydraulic pressure sensitivity of the float 27 based on the operation of the engine throttle lever 20 is set to be larger than that shown in FIG.
(B)). Thus, when the engine throttle lever 20 is operated, the float posture changes according to the amount of operation, and when the main shift lever 23 is operated, the float posture can be further greatly changed.

Next, the operation will be described.

When the planting clutch lever 22 is operated to the "automatic" position, the hydraulic control valve 32 is automatically controlled via the linkage mechanism 35 based on the buoyancy acting on the float 27. That is, when the planting unit 24 is at the proper planting position,
The hydraulic control valve 32 is held to hold the planting section 24 at that position.

From this state, when the posture of the float 27 is disturbed due to the condition of the field during the planting operation, for example, when the planting part 24 rises with respect to the field surface and the buoyancy acting on the float 27 decreases, the float The forward movement of the arm 27 is lowered, and the movement is transmitted to the swing arm 42a as a counterclockwise rotation about the rotation fulcrum 57 through the pin 41 positioned at a predetermined position of the sensing plate 38 and the slot 38a. (See FIG. 2), the swing arm 42b also rotates in the same direction and presses the sensing rod 43 to the left in FIG.

As a result, the conversion lever 64 rotates counterclockwise in FIG. 2 around the pivotal connection portion 66, and moves the continuous traction link 45 leftward in the drawing. The movement amount at this time is transmitted to the arm 33 via the pin 68, and the operating shaft 32a of the hydraulic control valve 32 is rotated clockwise to discharge the oil in the hydraulic cylinder 30 from the hydraulic control valve 32. And the cylinder 30 is contracted to
Lower 4.

On the contrary, the planting part 24 descends and the float 2
When the buoyancy acting on the float 7 increases, the front of the float 27 is lifted, and the movement is detected by the sensing plate 38 and the swing arm 42.
The conversion lever 64 is rotated clockwise in FIG. The rotation of the conversion lever 64 causes the continuous traction link 45 to move rightward in the drawing. The movement amount at this time is transmitted to the arm 33 via the pin 68, and the operating shaft 32a of the hydraulic control valve 32 is rotated in the counterclockwise direction.
The hydraulic control valve 32 is switched so as to pump the hydraulic oil to the hydraulic cylinder 30, and the cylinder 30 is extended to
4 is raised.

On a relatively soft rice field,
By increasing the sensing sensitivity of the float 27,
Can be controlled by operating the hydraulic sensitivity adjustment lever 31 in a direction to increase the sensitivity from a predetermined position, thereby making it possible to appropriately control the raising and lowering of the planting portion 24, and at the same time, the posture of the float 27 The adjusted and more appropriate elevation control of the planting section 24 is performed.

On a relatively hard rice field, the sensitivity of the float 27 can be lowered to control the raising and lowering of the planting section 24.
Is operated in a direction of lowering the sensitivity from a predetermined position, it is possible to perform appropriate elevation control of the planting section 24, and at the same time, adjust the attitude of the float 27, thereby performing more appropriate elevation control of the planting section 24. Will be

Next, according to the present embodiment, when the engine speed is changed by operating the engine throttle lever 20, the attitude of the float 27 is changed in conjunction with this, and the operation of the main shift lever 23 is performed. Accordingly, when the vehicle traveling speed is changed, the attitude of the float 27 is changed in conjunction with the change. At this time, since the main shift lever 23 is larger than the engine throttle lever 20 as a margin for adjusting the vehicle running speed, the change in the float posture based on the operation of the main shift lever 23 is considered from the viewpoint of the change amount of the float posture. The amount was made larger than the amount of change in the float posture based on the operation of the engine throttle lever 20. In this way, according to changes in the engine speed and the vehicle running speed,
The float posture can be adjusted, and the stabilization of the planting accuracy can be achieved without impairing the followability of the float 27 to the rice field surface even when the work speed is increased.

[0048]

As described above, according to the first aspect of the present invention, the oil pressure sensitivity adjusting means is linked with the engine speed adjusting means and the speed change operating means. Since the oil pressure sensitivity of the grounding body can be adjusted based on the operation of at least one of the means, the oil pressure sensitivity of the grounding body is adjusted in accordance with changes in the engine speed and the vehicle running speed. Even when the speed is increased, it is possible to stabilize and improve the working accuracy without impairing the ability of the grounding body to follow the rice field.

According to the second aspect of the present invention, the adjustment amount of the hydraulic sensitivity by operating the shift operation means is made larger than the adjustment amount of the hydraulic sensitivity by operating the engine speed adjusting means,
In other words, since the amount of adjustment of the hydraulic sensitivity by the speed change operation means having a larger speed adjustment allowance than the engine speed adjustment means is increased, it is possible to prevent instantaneous jumping of the ground contact body, for example, during high-speed running.

According to the third aspect of the present invention, the hydraulic sensitivity is adjusted by adjusting the attitude of the grounding body, so that, for example, during high-speed running, the grounding body is raised forward (the rear part of the grounding body is lowered). ), The hydraulic control valve can be easily operated in the downward direction, and floating seedlings can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a riding rice transplanter to which the present invention is applied.

FIG. 2 is a side view of a state where the float and a hydraulic control valve are connected by a linking mechanism.

FIG. 3 is a side view showing a connection relationship between a hydraulic sensitivity adjustment lever, an engine throttle lever, a main speed change lever, and the like.

FIG. 4 is a plan view of the same.

FIG. 5A is a perspective view of a connection relationship between a hydraulic sensitivity adjustment lever, an engine throttle lever, a main shift lever, and the like, and FIG. 5B is a diagram illustrating an adjustment amount of hydraulic sensitivity by the main shift lever and an engine throttle lever. FIG. 4 is a diagram illustrating a relationship with an adjustment amount of hydraulic pressure sensitivity.

FIGS. 6A and 6B show the attitude control of the float, in which FIG. 6A is a diagram showing a forward ascending state, and FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Riding rice transplanter 15 Running body 20 Engine throttle lever (engine rotation speed adjusting means) 23 Main shift lever (shift operation means) 24 Planting part (working part) 27 Float (grounding body) 30 Hydraulic cylinder 31 Hydraulic sensitivity adjusting lever ( Hydraulic sensitivity adjusting means) 31 'lever arm 31a bracket 31b horizontal axis 31c axis 32 hydraulic control valve 35 connecting mechanism 40 float sensitivity adjusting wire 42 swing arm 43 sensing rod 46 return spring 47 valve interlocking wire 75 connecting tool 75a hook-shaped plate 75b U-shaped plate 75c L-shaped plate

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2B062 AA05 AB01 BA62 CA02 CA04 CA06 CA12 2B063 AA08 AB01 AB08 BB08 BB21 CA04 CA07 CA10 CA12 CB11 2B304 KA13 LA02 LA09 LB05 LB16 MA02 MB02 MC06 PA01 PA11 PB02 PC02 PD17 RA01 RA07

Claims (3)

[Claims] 1. A posture of a working unit supported by a hydraulic cylinder device so as to be able to move up and down on a traveling machine body is sensed by buoyancy acting on a ground contacting body that moves while being grounded on a field scene, and controls the hydraulic cylinder device. By connecting a hydraulic control valve to the grounding body via a linking mechanism and controlling the hydraulic control valve based on buoyancy acting on the grounding body, the working unit controlled to be raised and lowered by the hydraulic cylinder device In a paddy field working machine for transplanting seedlings to a field, the linking mechanism has a hydraulic sensitivity adjusting means capable of adjusting the hydraulic sensitivity of the grounding body, and the hydraulic sensitivity adjusting means has an engine speed for adjusting the engine speed. The number adjusting means and the shift operating means for adjusting the vehicle running speed are linked, and based on the operation of at least one of the engine speed adjusting means and the shift operating means. , The hydraulic sensitivity is adjustable. 2. An adjustment amount of a hydraulic sensitivity of the grounding body based on an operation of the speed change operation means is made larger than an adjustment amount of a hydraulic sensitivity of the grounding body based on an operation of the engine speed adjusting means. The paddy field working machine according to claim 1, characterized in that: 3. The paddy working machine according to claim 1, wherein the adjustment of the hydraulic sensitivity is performed by adjusting a posture of the grounding body.