JPH11103623A - Earth pressure sensing device in transplanter - Google Patents

Abstract

(57) Abstract: A link ratio adjusting section is provided in the middle of a sensing link mechanism for connecting a hydraulic control valve and a float, and the earth pressure sensing sensitivity is adjusted by the link ratio adjusting section. SOLUTION: In the riding rice transplanter 1, a working unit 10 having a float 14 is supported by a hydraulic cylinder device 19 so as to be able to move up and down. A hydraulic control valve 35 for controlling the hydraulic cylinder device 19 includes a sensing link mechanism 15. Is connected to the float 14. This hydraulic control valve 35
Is controlled based on the earth pressure load acting on the float 14, and the sensing link mechanism 15 has a link ratio adjusting section 20 in the middle thereof. The link ratio on the input / output side can be changed by the link ratio adjusting unit 20, and the hydraulic control valve 35 is controlled by the moved amount after the change, so that the earth pressure sensing sensitivity can be changed according to the hardness of the rice field. Adjustable

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transplanting machine such as a rice transplanter for riding, and more particularly to a transplanting machine such as a rice transplanting machine. The present invention relates to an earth pressure sensing device in a transplanter.

[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 to a manual position and an automatic position.
At the automatic position of the lever, earth pressure acting on the float of the planting part is sensed, and the planting part is automatically raised and lowered by hydraulic pressure so as to be at the proper planting position.

[0003] When the mud in the field is soft, the front part of the float generally falls and becomes muddy, so that the planting part 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 means for solving this, for example, by changing the sensing point of the earth pressure acting on the float, if the mud is soft, the earth pressure is detected early by lowering the sensing point, and if the mud is hard, Can be considered as a means for detecting the earth pressure with the sensing point up (hereinafter, the former conventional example) and a means for changing the float sensing load to a larger or smaller size (hereinafter, the latter conventional example).

In the former prior art, the front part of the float is forcibly changed in the vertical position to change the sliding posture of the float, and the float sensing point is changed in the vertical direction to correspond to the field conditions. Things are known.

[0006] Further, as the latter conventional example, by controlling the vertical movement of the float with high sensitivity in accordance with the hardness of the field scene, or by controlling the float with a reduced sensitivity, the sensing load of the float is changed to respond. For example, the techniques described in Japanese Patent Publication No. 2-58892 and Japanese Utility Model Publication No. 59-30659 are known.

According to the latter conventional example, when the mud is soft, the tension of the spring for urging the float in the direction of the field is reduced, and the float can move upward even with a slight earth pressure. The float can be controlled up and down with sensitivity, and when the mud is hard, the tension of the spring is increased to increase the float's upward movement resistance. Thus, the vertical movement of the float is controlled with low sensitivity.

[0008]

However, according to the former conventional example described above, the front point of the float is forcibly adjusted up and down in accordance with the hardness of the field scene to change the sensing point. In the case of extremely soft mud, the float's front will sink and push the mud, even if the front of the float is lowered and the earth pressure is sensed as soon as possible. However, there was a risk that it would go underground more and more.

According to the latter conventional example, a spring for urging the float in the field direction is disposed near the float, the urging force of the spring is connected to the float via a link mechanism, and the operation of the adjusting lever is further performed. Therefore, there is a problem that the number of parts increases and the structure becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a link ratio adjusting section in a sensing link mechanism for connecting a hydraulic control valve and a grounding body, It is an object of the present invention to provide an earth pressure sensing device in a transplanting machine which can change an earth pressure sensing sensitivity and a sensing load acting on a grounded body by operating the link ratio adjusting unit.

[0011]

According to one aspect of the present invention, there is provided a working unit (10) having a traveling body (5) having a grounding body that moves while being grounded on a field scene.
Is supported by a hydraulic cylinder device (19) via a lifting link mechanism (8), and a hydraulic control valve (35) for controlling the hydraulic cylinder device (19) is connected via a sensing link mechanism (15). A transplanter (1) that is connected to the grounding body, controls the hydraulic control valve (35) based on an earth pressure load acting on the grounding body, and transplants seedlings to a field scene in the working unit (10); In the above, the sensing link mechanism (15) has a link ratio adjusting section (20) at an intermediate portion, and based on an earth pressure load acting on the ground contact body based on a change in the link ratio of the link ratio adjusting section (20). The vertical movement amount of the ground contact body is changed to a predetermined ratio, and the hydraulic control valve (35) is controlled based on the changed movement amount.

According to a second aspect of the present invention, the grounding body is a float (14), and an earth pressure load acting on the float (14) is changed to a predetermined ratio via the link ratio adjusting section (20). The hydraulic control valve (35) is controlled by the changed float sensing load.

According to a third aspect of the present invention, the float (1)
4) A float posture changing unit (50) is connected to the float posture changing unit (50) via a wire member (71). The earth pressure load acting on (14) is changed to a predetermined ratio via the link ratio adjusting unit (20), and the hydraulic control valve (35) is changed with the changed load.
Is controlled.

According to a fourth aspect of the present invention, the float (1)
4), the float attitude converting section (50) is connected via a wire member (71), and the float attitude converting section (50) is urged to bias the hydraulic control valve (35) in one direction. Connected to the sensing link mechanism (15) via a force setting means (45),
By the operation 0), the vertical position of the front part of the float can be changed, and the setting force of the return force setting means (45) can be changed in conjunction with the operation of the float posture conversion unit (50). , Characterized in that.

According to a fifth aspect of the present invention, the float (1)
The earth pressure load acting on the link ratio adjusting unit (2)
0) via the hydraulic control valve (3
5) so that the operation dead band of the float (14) can be set large, and the link ratio adjustment unit (20)
Hydraulic control valve (35) with a large link ratio via
And the operation dead zone of the float (14) can be set small. (Action) By the above-mentioned invention specifying matter, the transplanter (1)
A working unit (10) having a grounding body (14) is supported by a hydraulic cylinder device (19) so as to be able to move up and down. A hydraulic control valve (35) for controlling the hydraulic cylinder device (19) is provided with a sensing link mechanism. It is connected to the grounding body (14) via (15), and is controlled based on the earth pressure load acting on the grounding body (14).

The sensing link mechanism (15) has a link ratio adjusting section (20) in the middle thereof, and operates the link ratio adjusting section (20) to link the input side and the output side. The ratio can be changed, and the grounding body (1
The vertical movement amount of the grounding body (14) based on the earth pressure load acting on 4) can be changed to a predetermined ratio by operating the link ratio adjusting unit (20), and the hydraulic amount is changed by the changed movement amount. The control valve (35) is controlled. Then, by changing the link ratio, it is possible to freely adjust the earth pressure sensing sensitivity according to the hard and soft field scene.

Note that the reference numerals in parentheses described above are shown for reference to the drawings, and do not limit the configuration of the present invention at all.

[0018]

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.
The vehicle has a traveling body 5 supported by the front wheels 2 and the rear wheels 3. The traveling body 5 has an engine 6 mounted on a front portion thereof.
The driver's seat 9 having the following is provided. The driver's seat 9 is provided with an engine throttle lever 74 for controlling the running speed of the machine body and a planting clutch lever 70 for engaging and disengaging the planting clutch (see FIG. 2).

Behind the traveling machine body 5, a planting section (working section) 10 is supported by a lifting link mechanism 8 having an upper link 8a and a lower link 8b so as to be vertically movable. Planting rod 11, float (grounding body) 1
4 and a seedling mounting table 12 on which mat seedlings can be mounted. The planting section 10 can be rolled freely by a rolling shaft (not shown) installed on a link support frame 55 (see FIG. 2) at the rear end of the lifting link mechanism 8.

A hydraulic cylinder device 19 is disposed between a transmission case 16 provided at the front of the traveling machine body 5 and the lifting link mechanism 8, and the hydraulic cylinder device 19 controls the hydraulic pressure. The planting part 10 is controlled to move up and down by expanding and contracting based on the operation of the valve 35.

The hydraulic control valve 35 is composed of a rotary pool valve. As shown in FIGS. 1 and 2, the hydraulic control valve 35 is disposed below the driver's seat 9 and has an arm 37 attached to a shaft 35a integral with the spool. ing. The arm 37 is connected to the float 14 via a sensing link mechanism 15 described later, and the hydraulic control valve 35 is automatically controlled based on a change in the earth pressure acting on the float 14, and the hydraulic cylinder device 19 expands and contracts.

The float 14 is, as shown in FIG.
The rear part is connected to a shaft 58 provided below the transmission case 61.
Are pivotally mounted via arms 57 and 59 which can be integrally rotated about the sensor plate.
2 is pivoted and connected. The transmission case 61
The fulcrum shaft 67 provided at the bottom is provided with a planting depth adjusting lever 6.
8 and the bracket 66 are integrally fixed, and furthermore, the bracket 66 and the arm 57 are pin-connected, and by manually operating the planting depth adjusting lever 68, the vertical position of the float 14 is adjusted. It is possible.

Although detailed description is omitted, when the float 14 is adjusted upward or downward by operating the planting depth adjusting lever 68 up and down, the fulcrum shaft 67 rotates and the connecting rod 65 moves. Thereby, the pivot 60 of the swing arm 75 is connected to the connecting shaft 21 of the lifting link mechanism 8.
Move up and down around.

As shown in FIG. 3, the sensing plate 62 has a lower end pivotally supported on the float 14 by a connecting pin 62a, and has an elongated hole 62b formed near the upper end thereof. A Bowden wire 71 is fixed to an upper end portion of the sensing plate 62, and a pin 72 fixed to an inner wire 71a of the wire 71 is fitted in the long hole 62b.

Here, in the present embodiment, the sensing link mechanism 15 has a link ratio adjusting section 20 at an intermediate position, and the grounding body (float) is provided based on a change in the link ratio of the link ratio adjusting section 20. The vertical movement amount of the grounding body (float) 14 based on the earth pressure load acting on the 14 is changed to a predetermined ratio, and the hydraulic control valve 35 is controlled based on the changed movement amount.

That is, in FIG. 3, the sensing link mechanism 15 includes the sensing plate 62 and the sensing rod 3 connected to the sensing plate 62 via a swing arm 75.
9 and a continuous traction link 42 connected to the sensing rod 39 via the link ratio adjusting unit 20.
The other side is connected to the hydraulic control valve 35.

The swing arm 75 is a bifurcated arm 75a, 7 that can swing integrally about the pivot 60.
5b, the arms 75a, 75b are brought close to the connecting shaft 21 by a connecting plate 23 mounted on a connecting shaft 21 connecting the lower links 8b, 8b on the left and right sides of the body at the rear of the lifting link mechanism 8. Are located. For this reason,
The rotation fulcrum 60 is rotatable with respect to the connection shaft 21 of the lifting link mechanism 8 with a radius equal to the dimension between the rotation fulcrum 60 and the connection shaft 21.

The sensing plate 62 and one arm 75a are connected via a pin 72 fitted in a long hole 62b of the sensing plate 62.
5a is formed in an arc shape so as not to abut on the connecting shaft 21. The sensing rod 39 is connected to the tip of the other arm 75b via a pin 32.

As described above, the tip of one arm 75a of the swing arm 75 is connected to the sensing plate 62 via the pin 72, and the tip of the other arm 75b is connected to the sensing plate 62 via the pin 32. The two connecting portions 72, 32 are connected to the sensing rod 39, and are arranged substantially vertically apart from the connecting shaft 21.

On the other hand, the above-mentioned Bowden wire 71 is connected to the pin 72, and a spring 76 is stretched between the wire connecting pin 72 and the float connecting pin 62a. The spring 76 stretches the inner wire 7la. hand,
The working length of the sensing plate 62, which is the length between the wire connecting pin 72 and the float connecting pin 62a, is set.

Next, the sensing rod 39 has an elongated rod member at the center in the longitudinal direction, a link fitting 40 is integrally attached to a rear portion of the rod member, and a pin joint is provided at a front portion. The part 38 is attached. In the link fitting 40, a pin 40a is erected near the center of one side,
A long hole 40b is formed at the other end. A pin 32 fixed to the tip of a swing arm 75b is fitted into the long hole 40b, and this pin 32 and the pin 40a
A spring 41 is stretched between them.

The link ratio adjusting section 20 includes the sensing rod 3
And a conversion lever 22 for connecting the link 9 and the continuous traction link 42. The swing-side end of the conversion lever 22 and the pin joint 38 of the sensing rod 39 are pivotally mounted on the pin 27 with the pin 27. . The base end of the conversion lever 22 is pivotally connected to the lower link 8b by a pivotal connection 17.

The conversion lever 22 is provided with a plurality of holes 22a along its longitudinal direction.
One end of the link 42 is attached by a pin 46 inserted into the link. Although the insertion position of the pin 46 can be freely changed by insertion and removal, the insertion position of the pin 46 can be automatically changed and controlled via an actuator, for example.

The other end of the continuous traction link 42 is connected to the arm 37 of the hydraulic control valve 35 via the pin 43 as described above. Further, a pin 44 is implanted in an intermediate portion of the continuous traction link 42, and a return spring 45 is stretched on the pin 44, and the continuous traction link 42 is always lowered by the return spring 45. Biased in the direction.

As described above, when the connection point between the conversion lever 22 and the continuous traction link 42 is changed by inserting and removing the pin 46 in the link ratio adjustment unit 20, the amount of rotation of the sensing rod 39 about the pivot connection unit 17 ( The amount of vertical movement of the float 14) and the amount of rotation of the continuous traction link 42 are changed according to the connection point.

For example, in FIG. 3, the distance between the pivotal connection 17 on the base side of the conversion lever 22 and the pin 27 at the tip is R, and the distance between the pivotal connection 17 and the intermediate pin 46 is r.
Then, the ratio between the amount of rotation of the sensing rod 39 (the amount of vertical movement of the float 14) and the amount of rotation of the continuous traction link 42 is R / r
The rotation amount of the sensing rod 39 is transmitted to the continuous traction link 42 as a reduced movement amount. Then, the hydraulic control valve 35 is controlled by the changed movement amount changed to the predetermined ratio.

Further, in the present embodiment, the earth pressure load acting on the float 14 is
And the hydraulic control valve 35 is controlled by the float sensing load after the change.

That is, when the connecting point between the conversion lever 22 and the continuous traction link 42 is changed by inserting and removing the intermediate pin 46 in the link ratio adjusting section 20, the pivotal connecting section 1
The load applied to the sensing rod 39 centered at 7 (the float 14 sensed load) and the load transmitted to the continuous traction link 42 are changed according to the connection point.

For example, as described above, if the distance between the pivotal connection 17 of the conversion lever 22 and the pin 27 at the tip is R, and the distance between the pivotal connection 17 and the intermediate pin 46 is r, the sensing rod The ratio between the load applied to the link 39 (the load sensed by the float 14) and the load transmitted to the continuous traction link 42 is r / R, which is opposite to the above, and the load applied to the sensing rod 39 is enlarged and applied to the continuous traction link 42. Is transmitted.

From the viewpoint of the load sensed by the float 14, when the biasing force of the return spring 45 biasing the float 14 in the downward direction is P, the sensing rod 39 has a P · r / R And the load proportional to this load (P · r / R) acts in the lowering direction of the float 14 (however, excluding the weight of the float itself and the friction between the links).

On the other hand, when the link ratio in the link ratio adjusting unit 20 is not changed (link ratio = R / R),
The urging force P of the return spring 45 is applied to the sensing rod 3 as it is.
Therefore, when the link ratio is changed as described above, a smaller load acts on the float 14 in a lowering direction than when the link ratio is not changed. Therefore, when the link ratio is changed, the float 14 can move upward even with a small earth pressure load, and thus the float sensing load is changed.

In the above description, even if the earth pressure sensing sensitivity or the float sensing load is changed by the link ratio adjustment of the link ratio adjusting unit 20, the sliding posture of the float 14 does not change at all.

Next, in this embodiment, a float posture changing unit is connected to the float 14 via a wire member 71, and the vertical position of the front part of the float can be freely changed by operating the float posture changing unit. And the earth pressure load acting on the float 14 is
The ratio is changed to a predetermined ratio via 0, and the hydraulic control valve 35 is controlled with the changed load.

That is, the slot 6 of the sensing plate 62
2b is connected to the sensitivity adjusting lever (float attitude changing unit) via the inner wire 71b.
It is connected to the actuating part 50a on the base side of the part 50. The operation of the sensitivity adjusting lever 50 causes the operating portion 50a to rotate about the rotation fulcrum 51, whereby the inner wire 71b is expanded and contracted. Thus, the vertical position of the front part of the float 14 is changed, and the float 14
Is changed.

Accordingly, the sliding posture of the float 14 can be changed by operating the sensitivity adjusting lever 50,
If the earth pressure load acting on the float 14 is changed to a predetermined ratio by the link ratio adjusting unit 20, and the hydraulic control valve 35 is controlled with the changed float load,
The float posture can be set freely according to the float sensing load.

Further, in the present embodiment, the float attitude converting section 50 is connected to the float 14 via a wire member 71 and the float attitude converting section 50 is connected to the float 14.
Is connected to the sensing link mechanism 15 via a return force setting means for returning the hydraulic control valve 35 in one direction,
The vertical position of the front portion of the float 14 can be changed by the operation of the float posture changing unit 50, and the setting force of the return force setting unit can be changed in conjunction with the operation of the float posture changing unit 50. .

In FIG. 3, a wire 24 is connected to the sensitivity adjusting lever 50, and the other end of the wire 24 is erected on the continuous traction link 42 via a return spring (return force setting means) 45. Connected to pin 44. The return spring 45 plays a role of constantly urging the hydraulic control valve 35 in the direction in which the float 14 is lowered.

That is, as shown in FIG. 4, the wire 24 has an inner wire 24a inside, a connection fitting 25 is attached to one end of the inner wire 24a, and a hinge 26 is attached to the other end. A round hole 28 and an oblong hole 29 are formed in the connection fitting 25, and the connection fitting 25 is locked to the projection 50 b of the sensitivity adjustment lever 50 via the oval hole 29.

One end of a throttle wire 73 is connected to the round hole 28, and the other end of the wire 73 is connected to an engine throttle lever 74.

As described above, when the sensitivity adjusting lever 50 is tilted, the operating portion 50a also swings about the pivot 51, so that the float 14 is connected via the Bowden wire 71 connected to the operating portion 50a. The vertical position of the front is changed. At the same time, when the wire 24 locked to the projection 50b of the sensitivity adjusting lever 50 moves within the length range of the oblong hole 29 of the connection fitting 25, the urging force of the return spring 45 is changed. Is done.

The change in the urging force of the return spring 45 is transmitted to the float 14 via the continuous traction link 42, the link ratio adjusting section 20, the sensing rod 39 and the like, and the float sensing load is changed.

This makes it possible to change the sliding posture of the float 14 and change the sensing load of the float 14 by the return spring 45. For example, on a soft rice field, the float sensing load is reduced, and the sensing point is quickly set. However, by increasing the float sensing load and delaying the sensing point on a hard rice field, it is possible to extend the applicable range from a hard rice field to a soft rice field.

Further, in the present embodiment, the earth pressure load acting on the float 14 is
To the hydraulic control valve 35 with a small link ratio through the link ratio to enable the operation dead zone of the float 14 to be set large, and to the hydraulic control valve 35 with a large link ratio through the link ratio adjusting unit 20. And float 1
The operation dead zone of No. 4 can be set small.

In other words, when the vertical movement amount of the float 14 is fixed, if the link ratio is set to a smaller value for adjusting the link ratio adjusting unit 20, the hydraulic control valve 3
A movement amount smaller than the vertical movement amount of the float 14 is transmitted to 5. Thus, even if the float 14 moves up and down by a predetermined amount, only a small amount of displacement is transmitted to the hydraulic control valve 35, so that the hydraulic control valve 35 is slightly displaced, and the operation dead zone of the float 14 is increased. .

On the other hand, if the link ratio is set to a value larger than the adjustment of the link ratio adjusting section 20, a movement amount larger than the vertical movement amount of the float 14 is transmitted to the hydraulic control valve 35. Accordingly, when the float 14 moves up and down by a predetermined amount, a large displacement is also transmitted to the hydraulic control valve 35, so that the hydraulic control valve 35 is also largely displaced, and the operation dead zone of the float 14 is reduced.

In this manner, the operation dead zone is increased on a soft rice field, the hunting of the hydraulic control valve 35 is prevented without reacting to slight irregularities on the rice field, and the operation dead zone is reduced on a hard rice field. By increasing the contact pressure of the float 14, small irregularities can be leveled by the contact pressure of the float 14 by the contact pressure.

Next, the operation of the above-described embodiment will be described.

When the elevation control lever (not shown) is operated to the automatic position, the hydraulic control valve 35 is controlled by the sensing link mechanism 15 via the swing arm 75 based on the earth pressure acting on the float 14. That is, when the planting unit 10 is at the proper planting position, the control plate (not shown) is at the fixed position via the operating shaft 35a of the hydraulic control valve 35, and the planter 10 is held by holding the hydraulic control valve 35. Hold in that position.

In this state, when the planting section 10 rises with respect to the rice field surface and the earth pressure acting on the float 14 decreases, the front of the float 14 drops, and the movement is detected by the sensing plate 62.
And the pin 7 positioned at a predetermined position of the long hole 62b
The rotation is transmitted to the swing arm 75a via the rotation support 2 as a counterclockwise rotation, and the swing arm 75b is further rotated via the rotation fulcrum 60.
Also rotate in the same direction to press the sensing rod 39 to the left.

Prior to the planting operation, the link ratio of the link ratio adjusting unit 20 is adjusted in advance by inserting and removing the pin 46. In this example, the case where the paddle surface is soft is considered, and the pin 46 is moved in the longitudinal direction of the conversion lever 22. Is positioned at an intermediate position. For example, in FIG. 3, the distance between the pivotal connection portion 17 of the conversion lever 22 and the pin 27 at the tip is R,
The distance between the pivot connecting portion 17 and the intermediate pin 46 is represented by r.

The leftward pressing force of the sensing rod 39 at this time causes the conversion lever 22 to rotate counterclockwise about the pivotal connection 17. Then, the ratio of the amount of rotation of the sensing rod 39 in the counterclockwise direction about the pivotal connection portion 17 to the amount of rotation of the continuous traction link 42 in the same direction is R / r, and the amount of rotation of the sensing rod 39 is R / r. Is reduced and transmitted to the continuous traction link 42 as the amount of movement to the left in the drawing.

Further, the amount of movement to the left in the drawing transmitted to the continuous traction link 42 is transmitted to the arm 37 via the pin 43, and the operating shaft 35a of the hydraulic control valve 35 is rotated clockwise. The hydraulic control valve 35 is switched to discharge the oil in the hydraulic cylinder device 19, and the cylinder device 19 is contracted to lower the planting section 10.

On the contrary, when the planting portion 10 descends and the earth pressure acting on the float 14 increases, the front of the float 14 rises, and the movement is detected by the sensing plate 62 and the swing arm 7.
The conversion lever 22 is rotated clockwise about the pivot connection 17 via the sensing rods 5a and 75b. The rotation of the conversion lever 22 causes the continuous traction link 4
2 to the arm 37 via the continuous traction link 42 and the pin 43.
By rotating the operating shaft 35a of the hydraulic control valve 35 in a counterclockwise direction, the hydraulic control valve 35 is switched so as to pressurize the hydraulic oil to the hydraulic cylinder device 19, and the cylinder device 19
Is extended to raise the planting section 10 to an appropriate position.

In the above description, assuming that the urging force of the return spring 45 is P, the load acting on the sensing rod 39 to the left in FIG. 3 based on this urging force is P · r / R (= P
Smaller) and the load proportional to this is float 1
4 is urged downward. That is, the force for urging the float 14 in the downward direction is smaller than the urging force P of the return spring 45, and thus the float 14 is urged with a small sensed load.
Is controlled. Conversely, the link ratio adjusting unit 20
If the link ratio is set large, the float 14 is controlled with the larger float sensing load. Even if the float sensing load is changed by the link ratio adjustment of the link ratio adjusting unit 20, the float sliding posture does not change.

On the other hand, for example, when transplanting a seedling on an extremely soft paddy field and wishing to further reduce the float sensing load, it may not be possible to cope only by adjusting the link ratio. In such a case, the link ratio is adjusted, the sliding posture of the float 14 is changed, and the change of the float sensing load and the change of the sensing point of the float 14 are used together.

That is, for example, the sensitivity adjusting lever 50 is tilted in the direction of arrow A in FIG. Then, the operating portion 50a of the sensitivity adjustment lever 50 rotates rightward in the drawing around the rotation fulcrum 51. As a result, the Bowden wire 71
Of the inner wire 71a is loosened, the tension of the spring 76 on the sensing plate 62 side is reduced, and the force for lifting the front portion of the float 14 is reduced, so that the float 14 is lowered forward.

For this reason, the sensing point of the float 14 moves downward, and the earth pressure fluctuation is sensed earlier. as a result,
The earth pressure fluctuation is transmitted to the hydraulic control valve 35 at an early stage, and the planting section 10 is appropriately controlled to move up and down. In addition, contrary to the above,
When the sensitivity adjusting lever 50 is tilted in the direction of arrow B in FIG. 3, the front portion of the float 14 is lifted, and the sensing point of the float 14 is moved upward.

When the sensitivity adjusting lever 50 is tilted as described above, the urging force of the return spring 45 which urges the hydraulic control valve 35 in the downward direction fluctuates in conjunction with the tilting operation. That is, when the sensitivity adjusting lever 50 is tilted in the direction of arrow A in FIG. 3, the urging force of the return spring 45 via the wire 24 increases, and the force urging the float 14 in the downward direction increases. Thus, the float sensing load increases. Conversely, when the sensitivity adjusting lever 50 is tilted in the direction of arrow B in FIG. 3, the urging force of the return spring 45 via the wire 24 is reduced, and the float sensing load is reduced.

As described above, the operation of the link ratio adjustment unit 20 and the operation of the sensitivity adjustment lever 50 are selectively used as
An appropriate planting depth and planting posture can be maintained according to the hardness of the rice field.

[0071]

As described above, according to the first aspect of the present invention, the earth pressure sensing sensitivity can be arbitrarily changed by changing the link ratio, whereby the soil can be freely adjusted according to the hard and soft field scene. Good planting can be achieved by adjusting the pressure sensing sensitivity.

Further, since the vertical movement amount of the ground contact body can be reduced and transmitted to the hydraulic control valve by changing the link ratio, for example, hunting may occur in the hydraulic control valve due to movement of the float due to slight unevenness in the field scene. Stable running can be achieved by avoiding it.

According to the second aspect of the present invention, since the float sensing load is made variable by changing the link ratio, it is possible to cope with a wide range from a soft field scene to a hard field scene, and a good planting operation becomes possible. .

Further, since the float sensing load can be changed without changing the posture of the float, mud pushing is prevented even in a soft field scene, for example, and the float sliding posture can be improved. Therefore, the traveling speed of the aircraft can be increased, and the work efficiency can be improved.

Further, as compared with the conventional method, the contact pressure is changed by changing the tension of the spring disposed near the float.
The structure is simple and the number of parts is small.

According to the third aspect of the present invention, since the change of the float sensing load by the change of the link ratio and the change of the float posture by the operation of the float posture conversion unit are used together, the posture of the float is adjusted in accordance with the float sensing load. It can be set freely, and the work area can be greatly expanded according to the hardness of the field scene.

Further, even if the sensing point slightly changes due to a change in the float sensing load due to a change in the link ratio, the change can be corrected by changing the float attitude, so that the float attitude does not change as a whole and the planting performance can be stabilized. Connect.

Further, since both the change of the float sensing load and the change of the float posture can be performed, it is possible to cover a wide range from a hard field scene to a soft field scene.

According to the fourth aspect of the invention, it is possible to change both the sensing point by changing the attitude of the float and the float sensing load by changing the return load of the return load setting means. In this case, the float sensing load is reduced and the float position is changed to increase the sensing point.In hard field scenes, the float sensing load is increased and the float position is changed to delay the sensing point. It can cover a wide area up to the surface, and the planting performance is also improved.

Further, since the float posture can be freely selected in accordance with the float sensing load, mud pushing is prevented even in a soft field scene, and an appropriate planting depth and planting posture can be obtained.

According to the fifth aspect of the present invention, when the float sensing load is small, the float dead zone becomes large, and when the float sensing load is large, the float dead zone becomes small. The operation dead zone is increased, and hunting of the hydraulic control valve can be prevented without reacting to slight irregularities. Also, in a hard field scene, the float sensing load is large,
Small irregularities are floated and the planting depth is kept constant.

[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 showing the whole earth pressure sensing device according to the present invention.

FIG. 3 is a side view showing a main part of the earth pressure sensing device.

FIG. 4 is an explanatory diagram of a wire connecting a sensitivity adjusting lever and a return spring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Riding rice transplanter 5 Running body 8 Elevating link mechanism 10 Planting part 14 Float 15 Sensing link mechanism 19 Hydraulic cylinder device 20 Link ratio adjusting part 21 Connecting shaft 22 Conversion lever 35 Hydraulic control valve 39 Sensing rod 45 Return spring 50 Sensitivity adjusting lever 62 Sensing plate 70 Planting clutch lever 71 Bowden wire 74 Engine throttle lever

Claims (5)

[Claims] 1. A hydraulic control valve for controlling a hydraulic cylinder device while supporting a working unit having a grounded body which is grounded and moved on a field scene by a hydraulic cylinder device via a lifting link mechanism. Is connected to the grounding body via a sensing link mechanism, the hydraulic control valve is controlled based on an earth pressure load acting on the grounding body, and a transplanter for transplanting seedlings to a field scene in the working unit. The sensing link mechanism has a link ratio adjustment unit in the middle,
Based on the link ratio change of the link ratio adjusting unit, the vertical movement amount of the grounding body based on the earth pressure load acting on the grounding body is changed to a predetermined ratio, and the hydraulic control valve is controlled with the changed movement amount. An earth pressure sensing device in a transplanter, characterized in that: 2. The float as the grounding body, wherein the earth pressure load acting on the float is changed to a predetermined ratio via the link ratio adjusting section, and the hydraulic control valve is operated with the changed float sensing load. The earth pressure sensing device in the transplanting machine according to claim 1, wherein the earth pressure sensing device is controlled. 3. A float posture changing part is connected to the float via a wire member, and the float front part can be vertically moved by operating the float posture changing part, and the soil acting on the float can be changed. The soil in the transplanting machine according to claim 2, wherein the pressure load is changed to a predetermined ratio via the link ratio adjusting unit, and the hydraulic control valve is controlled with the changed load. Pressure sensing device. 4. The float attitude conversion unit is connected to the float via a wire member, and the float attitude conversion unit is connected to the float via return force setting means for urging the hydraulic control valve in one direction. By connecting to the sensing link mechanism, the vertical position of the float front part can be changed by the operation of the float posture changing part, and the setting force of the return force setting means is linked with the operation of the float posture changing part. The earth pressure sensing device in the transplanter according to claim 3, wherein the earth pressure sensing device can be changed. 5. An earth pressure load acting on the float is transmitted to the hydraulic control valve via the link ratio adjusting section at a small link ratio so that the float dead zone can be set to a large value. The earth pressure sensing device for an implanting machine according to claim 2, wherein the operation dead band of the float can be set to be small by transmitting to the hydraulic control valve with a large link ratio via a ratio adjusting unit.