JPH1142006A - Lifting motion control mechanism for rice-transplanting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject mechanism capable of lifting a planting section on a detected value obtained in such a manner as to mount liftably the planting section on a running vehicle, support axially a float at the lower part of the planting section, and hence improve a detecting precision of an inclination angle of the float. SOLUTION: This mechanism is provide with such a constitution as to support elastically the front section of a float 34 by an expandable member, detect an expansion amount of the expandable member by a sensor 71, and lift a planting section 15 correspondingly to the expansion amount, wherein a hardness of a field surface is detected by using the resistance in the field surface measured by thrusting a detecting member disposed at the lower part of the planting section 15 into the field surface, an inclination angle of the float to activate the lifting mechanism is changed corresponding to the detected value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice transplanter in which a planting portion is moved up and down by using an elevating mechanism in accordance with unevenness of a planting surface, and the sensitivity of a sensor for detecting the unevenness is adjusted according to the hardness of the planting surface. Configuration.

[0002]

2. Description of the Related Art Conventionally, a planting section of a rice transplanter has been suspended from the rear of a traveling vehicle using a lifting mechanism so as to be movable up and down, and a plurality of flattening floats formed below the planting section. The front part of each float is arranged so as to be able to rotate up and down, and a sensor for detecting the downward inclination is arranged in the center float arranged in the center of the left and right of each float, and the detection sensitivity by the sensor On a planting surface having a high hardness, the sensor was adjusted to be insensitive so as to detect only large irregularities, and on a planting surface having a soft hardness, the sensor was sensitively adjusted so that even small irregularities could be detected. Further, the sensitivity of the sensor has been switched by an operator so as to be manually adjusted to the planting surface.

[0003]

However, in order to adjust the sensitivity manually by the conventional method, the frequency of changing the sensitivity increases in response to the diversification of conditions (surface hardness, unevenness, etc.) due to the large compartment, and the There has been a problem that it is almost impossible for an operator to always perform appropriate sensitivity adjustment according to the conditions.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, in a configuration in which a planting portion is attached to a traveling vehicle so as to be able to move up and down, a float is pivotally supported at a lower portion of the planting portion, and the planting portion is moved up and down according to a tilt angle of the float. Elastic support. Further, the float front portion is elastically supported by an elastic member,
The amount of expansion and contraction of the elastic member is detected by a sensor, and the planting section is moved up and down according to the amount of expansion and contraction. In addition, a detection member is arranged below the planting portion, the detection member is made to protrude into the surface of the field, the hardness of the field surface is detected from the resistance of the surface of the field, and an elevating mechanism is operated according to the detected value. The tilt angle of the float to be operated is changed. Further, an impeller is pivotally supported on the float, the outer peripheral end of the impeller is pushed into the field surface, the impeller is rotated by receiving resistance from the field surface, and the lifting mechanism is moved in accordance with the rotation speed. The tilt angle of the float that activates is changed. Further, a speed sensor for detecting a vehicle speed is provided, an impeller is pivotally supported on the float, an outer peripheral end of the impeller is pushed into a field surface, and the impeller is rotated by receiving resistance from the field surface. Thus, the inclination angle of the float for operating the lifting mechanism is changed according to the rotation speed and the traveling speed of the impeller. Further, two gears having different rotational torques are pivotally supported on the float, the outer peripheral ends of the respective gears are pushed into the field surface, and the gears are rotated by receiving resistance from the field surface. The tilt angle of the float that operates the lifting mechanism is changed according to the difference between the two.

[0005]

Next, an embodiment of the present invention will be described. 1 is an overall side view of a riding rice transplanter, FIG. 2 is a plan view of the same, FIG. 3 is a side view showing a raising and lowering mechanism of a planting section, and FIG. 4 is a block diagram of a raising and lowering control mechanism of the planting section of the present invention. 5 is an explanatory view showing a configuration for adjusting sensitivity, FIG. 6 is a plan view of a center float provided with a detecting member for detecting hardness in a field, FIG. 7 is a partial sectional view of the same side view, and FIG. 8 is a detecting member for detecting hardness. FIG. 9 is a side view of a gear as a detection member, FIG. 10 is a cross-sectional view of the gear,
11 is a side view of a gear as a detection member, FIG. 12 is a cross-sectional view of the gear, FIG. 13 is a block diagram of a sensitivity adjustment mechanism, and FIG.
15 is a side view of the first embodiment for detecting the inclination of the center float, FIG. 15 is a rear sectional view thereof, FIG. 16 is a side view of the third embodiment of the detecting member for detecting the hardness, and FIG. FIG. 18 is a side view of the second embodiment for detecting the inclination of the center float, and FIG. 19 is a side view of the detection member of the second embodiment.

First, a riding rice transplanter is used in this embodiment as a traveling vehicle equipped with an electronic governor mechanism. The riding rice transplanter is configured as shown in FIGS. An engine E with an electronic governor mechanism is mounted above a front portion of a body frame 3 of a traveling vehicle on which an operator or the like rides, and a transmission case 4 is arranged at a rear portion of the body frame 3. A front wheel 6 is supported in front of the transmission case 4 via a front axle case 5, and a rear axle case 7 is connected to a rear portion of the transmission case 4 to support a rear wheel 8. A spare seedling mounting table 10 is provided above the hood 9 covering the engine E.
10 is disposed, the transmission case 4 and the like are covered by a vehicle body cover 2 on which an operator or the like rides via a step 11, and a driver's seat 13 is mounted on the vehicle body cover 2;
A steering handle 14 is provided at the rear of the hood 9 in front of the driver's seat 13.

[0007] The planting section 15 is a seedling mounting table 1 for six-row planting.
6 and a plurality of planting claws 17 and the like. The planting table 16 disposed at the front and rear heights is supported by the planting case 20 via the lower rail 18 and the guide rail so as to be reciprocally slidable left and right. A rotary case 2 that rotates at a constant speed in one direction
1 is rotatable on the planting case 20, and a pair of claw cases 22 are arranged at symmetrical positions about the rotation axis of the rotary case 21. The attachment claws 17 are fixedly provided.

As shown in FIG. 3, a support frame 24 is provided at the front of the planting case 20, and
5 and a link mechanism 27 including a lower link 26, which is connected to a rear portion of the work vehicle, and an elevating cylinder 28 for raising and lowering the planting section 15 via the link mechanism 27 is connected to the lower link 2.
6. The front wheels 6 and the rear wheels 8
8 is configured such that the seedlings for one plant are taken out from the seedling mounting table 16 which can reciprocate to the left and right at the same time as the drive 8 is moved and moved by the planting claws 17 and the seedlings are continuously planted. .

An arm 121 is fixed to the front end of the lower link 26 of the link mechanism 27, and an angle sensor 120 such as a potentiometer is provided on the rear part of the body frame 3, and a sensor arm 120a of the angle sensor 120 is provided. A long hole at the tip is connected to the arm 121. As shown in FIG. 4, the angle sensor 120 can be connected to the controller C to detect the height of the planting section 15 and confirm the elevation position of the planting section 15.

[0010] In addition, in the driving section in which the driver's seat 13 and the like are installed, a traveling speed change lever 29, an auxiliary speed change lever 30 for planting up / down and work traveling speed change, a planting sensitivity adjusting lever 31, a main clutch pedal 32, a left and right brake pedal 33, 33, a leveling center float 34 and a leveling side float 35 are disposed below the planting section 15, and a six-row fertilizer section 36 is disposed behind the driver's seat 13. Have been. The accelerator lever 1 is disposed on the hood 9.

Next, a configuration for automatically raising and lowering the planting section 15 will be described. As shown in FIG. 5, the planting unit 15 detects unevenness on the surface of the field, and
8 is expanded and contracted, so that the planting portion 1 is
5 was going up and down. As a configuration for detecting irregularities on the surface of the field, an inclination detecting means is provided on the center float 34. A bracket 90 is provided on the rear upper surface of the center float 34, and a base end of a planting depth adjusting link 92 is fixedly mounted on a planting depth adjusting fulcrum shaft 91 which is rotatably supported by the planting case 20; The bracket 90 is pivotally supported at the tip of the planting depth adjusting link 92 via a fulcrum shaft 93, and the center float 34 is rotatably supported.

Then, the middle of a link 95 is pivotally supported on a support shaft 94 fixedly supported on the planting case 20 side,
An arm 9 having a base end fixed to the planting depth adjusting fulcrum shaft 91.
The rear end of the link 95 is pivotally connected to the tip of No. 6. A planting depth lever 85 is fixed to the planting depth adjusting fulcrum shaft 91 so that the planting depth can be set. An engagement pin is provided at the front end of the link 95, and is inserted into the long hole of the sensor link 98. The lower end of the sensor link 98 is pivotally supported at the front of the center float 34.

An outer wire 99a of a sensor wire 99 is connected to an upper end of the sensor link 98,
The inner wire 99b is connected to a locking pin of the link 95. The other end of the outer wire 99a is connected to the planting sensitivity adjusting lever 31, and the inner wire 9a
The other end of 9b is connected to an arm 87, which is in contact with the spool of the elevating valve 86. Pressure oil is supplied to the lift cylinder 28 via the lift valve 86. Therefore, when the planting sensitivity adjustment lever 31 is tilted backward, the slack of the inner wire 99b is reduced, and the elevation valve 86 is switched to the elevation side with a slight rise of the center float 34 to increase the sensitivity. When the planting sensitivity adjustment lever 31 is tilted forward, the inner wire 9
The slack of 9b becomes large, and does not respond to the slight rise of the center float 34, so that the sensitivity becomes dull. A position sensor 31a for detecting the lever position is provided at the base of the planting sensitivity adjusting lever 31, and the position sensor 31a is connected to the controller C as shown in FIG.

Further, a sector gear 82 is fixed to the base of the planting sensitivity adjusting lever 31. A sensitivity correction motor 80 is linked to the sector gear 82 via a gear 81. The sensitivity correction motor 80 is connected to the controller C via a relay as shown in FIG. In this case, the controller C stores the position of the planting sensitivity adjusting lever 31 with respect to the hardness of the field surface in advance as a map. In this map, when the hardness of the field surface is high, the sensitivity correction motor 80 is driven to tilt the lever 31 forward, thereby reducing the sensitivity. When the hardness of the field surface is weak, the sensitivity correction motor 80 is driven to operate the lever 31.
Is tilted backwards, increasing sensitivity.

FIG. 6 and FIG. 7 show a first embodiment for detecting the hardness of the field surface. An arrangement port 34a is opened at the center of the center float 34 in the front-rear direction, and an impeller 60 is disposed as a detection member in the sensor arrangement port 34a. The rotating shaft 60a of the impeller 60
Are pivotally supported on the left and right side surfaces of the arrangement port 34a. A plurality of blades are fixed radially on the outer peripheral surface of the rotation shaft 60a. The blade of the impeller 60 is the center float 3
When the surface of the field is leveled by the center float 34, the blades of the impeller 60 protrude into the surface of the field. Further, the rotating shaft 60
A rotation speed sensor 61 is provided at one end of the line a. The rotation speed sensor 61 is connected to the controller C as shown in FIG.

Therefore, when the center float 34 advances along the surface of the field, mud on the surface of the field hits the blades and rotates the impeller 60. The rotation speed of the impeller 60 is Is increased or decreased by the resistance of the mud to the blades. When the hardness of the surface of the field is hard, the impeller 6
The impeller 60 is rotated at a high speed by giving a large resistance to zero. Conversely, when the hardness of the surface of the field is soft, the resistance applied to the impeller 60 is small, and the impeller 60 is rotated at a low rotation. That is, the hardness of the surface of the field is hard, the faster the center float 34 travels, the greater the resistance given to the impeller 60, the high rotation of the impeller 60 is rotated, and the hardness of the surface of the field is soft,
The lower the traveling speed of the center float 34, the lower the rotation of the impeller 60.

As shown in FIG. 1, a speed sensor 113 is provided on the axle of the rear wheel 8 to detect a traveling speed. The speed sensor 113 is also connected to the controller C as shown in FIG. The speed sensor 113 and the rotation speed sensor 61 are constituted by the same rotary encoder or the like. And it is controlled by the controller C as shown in FIG. An angle sensor 120 disposed on the link mechanism 27 for extending and retracting the elevating cylinder 28 detects that the planting section 15 is located at the working position. Next, by calculating the ratio of the detection value of the rotation speed sensor 61 to the detection value of the speed sensor 113, the ratio of the rotation speed of the impeller 60 to the vehicle speed is compared. The hardness of the field surface is determined.

When the controller C determines the hardness of the field surface, the position of the sensitivity adjustment lever 31 is determined based on the position of the sensitivity adjustment lever 31 for the field surface hardness stored in the controller C in advance. Is done. Next, the sensitivity correction motor 80 is driven. The sensitivity adjustment motor 31 is driven to rotate the sensitivity adjustment lever 31, and the rotation position of the sensitivity adjustment lever 31 is determined by the position sensor 31a. When it is detected that the sensitivity adjustment lever 31 has been rotated to the determined proper position, the drive of the sensitivity correction motor 80 is stopped, and the slack of the inner wire 99b is adjusted and controlled.

FIG. 8 shows a second embodiment for detecting the hardness of the field surface. Gears 63 and 64 as detection members are disposed at front and rear positions on the left and right sides of the center float 34. The gear 63
64 rotation shafts 63 a and 64 a are supported on the side surface of the center float 34. The teeth forming the outer peripheral surfaces of the gears 63 and 64 project below the bottom surface of the center float 34.

The gear 63 on one side of the left and right gears 63 and 64 has a large number of teeth and a large tooth width as shown in FIGS. When the teeth of the gear 63 protrude into the surface of the field, the teeth of the gear 63 can receive much resistance such as mud in the field, and the gear 63 is rotated at high speed. Also, the other gear 64
As shown in FIG. 11 and FIG. 12, the number of teeth of the gear 63 is smaller than that of the gear 63, and the tooth width of the gear 64 is tapered such that the tip end side is narrowed. When the teeth of the gear 64 protrude into the surface of the field, the resistance received by mud or the like in the field is reduced. Therefore, when the center float 34 advances, the gear 63 receives a large resistance and rotates at a high speed, while the gear 64 receives a small resistance and rotates at a low speed.

The difference between the rotation speeds of the gear 63 and the gear 64 is that when the surface hardness of the field is high, there is no difference in the rotation speed, but when the surface hardness of the field becomes soft. , The difference in the number of rotations is large. Further, the difference in the number of revolutions changes according to the traveling speed of the center float 34. As the traveling speed increases, the difference in the number of revolutions increases.

The ends of the rotating shafts 63a and 64a are connected to rotation sensors 65 and 66, respectively. The rotation sensors 65 and 66 are connected to the controller C as shown in FIG.

Further, a value detected by the speed sensor 113 disposed on the axle such as the rear wheel 8 is input to the controller C. The output values from the rotation sensors 65 and 66 are input to the controller C, and the output values from the speed sensor 113 are input to the controller C. Based on the current running speed and the difference between the rotation speeds of the left and right gears 63 and 64, the field scene is calculated. Judgment of hardness. As described above, the sensitivity correction motor 80 is driven based on this determination result, and the sensitivity adjustment control is performed.

The gears 63 and 64 have different shapes so that the resistance received from the surface of the field is different. However, the gears 63 and 64 having the same shape are used, and one of the gears 63 and 64 is used. It is also possible to provide a configuration in which a resistance is provided in advance to the rotating shaft 63a (64a) so that even if the gears 63 and 64 receive the same resistance from the field scene, a difference occurs in the rotation speed of the gears 63 and 64.

As a third embodiment for detecting the hardness of the field surface, an inclination sensor 67 shown in FIG. 16 can be used. The tilt sensor 67 is suspended integrally with a weight 68 as a detecting member. The weight body 68 is formed in a conical shape, has a top suspended downward, a bottom surface of the cone facing upward, and an inclination sensor 67 mounted on the bottom surface. The weight 68 is suspended from the planting section 15 or the center float 34 using an arm 69, and the top of the weight 68 is protruded into the surface of the field.
The tilt sensor 67 is connected to the controller C as shown in FIG.

The weight body 68 travels as the traveling vehicle travels, receives resistance from the surface of the field, and travels in an inclined manner as shown by a two-dot chain line 68 'in FIG. The resistance of the weight 68 changes depending on the hardness of the surface of the field, and when the hardness is high, the resistance increases and the weight 68
The slope of is increased. When the hardness is soft, the resistance is small, and the inclination of the weight body 68 is small. This inclination is detected by the inclination sensor 67,
Output to controller C.

Further, a value detected by the speed sensor 113 disposed on the axle such as the rear wheel 8 is input to the controller C. An output value from the tilt sensor 67 is input to the controller C, and the speed sensor 1
13, the hardness of the field scene is determined from the running speed at the current time and the inclination angle of the weight 68.
As described above, the sensitivity correction motor 80 is driven based on the result of this determination to adjust the sensitivity.

The hardness of the surface of the field is detected by using the detecting members shown in the first, second and third embodiments.
By automatically controlling the sensitivity adjustment lever 31 with respect to the detected value, the operator does not need to know the state of the hardness in the field, and the burden on the operator is reduced. In addition, the planting section can be raised and lowered appropriately in accordance with the condition of the field without manually adjusting the sensitivity, and an accurate planting operation can be performed.

The direction in which the pressurized oil is supplied to the raising / lowering cylinder 28 for raising and lowering the planting section 15 is switched by the raising / lowering valve 86. In the elevating valve 86, the forward-downward inclination of the center float 34 was detected via the sensor wire 99. In the present invention, the solenoid of the lift valve 86 is connected to the controller C as shown in FIG. The controller C
In addition, means for detecting the inclination angle of the center float 34 is connected, and the elevation valve 86 is expanded and contracted by using the controller C in accordance with the inclination of the center float 34, and the planting section 15 is controlled to elevate and lower.

A first embodiment of another embodiment for detecting the inclination angle of the center float 34 will be described with reference to FIGS. An elastic member 70 is provided at the front end of the link 95 instead of the sensor link 98. The expansion / contraction member 70 is composed of a rod 70a and a cylindrical portion 70b for loosely fitting the rod 70a in a stretchable manner, and urges the rod 70a toward the extending side via an urging member (not shown) in the cylindrical portion 70b. The elastic member 70 is configured like a damper. The end of the tubular portion 70b of the elastic member 70 is pivotally supported at the distal end of the link 95, and the end of the rod 70a is pivotally supported at the front of the center float 34. When the center float 34 is advanced along the surface of the field, and the surface is uneven, the expandable member 70 expands and contracts, and the center float 34 is inclined.

Further, an angle sensor 71 is provided immediately behind the elastic member 70. The angle sensor 71 is
A stay 72 is erected on the upper surface of the center float 34, and an angle sensor 71 is fixed on a side surface of the stay 72.
The sensing arm of the angle sensor 71 is in contact with the bottom of the cylinder 70b. Therefore, when the front part of the center float 34 is rotated upward while the elastic member 70 is contracted, the angle sensor 71 is also integrally raised, and the sensing arm is rotated downward while abutting on the bottom surface of the cylindrical part 70b. I have. The expansion / contraction of the elastic member 70 is detected by the angle sensor 71.

The angle sensor 71 is connected to a controller C as shown in FIG. The angle sensor 71 outputs the amount of expansion and contraction of the expansion member 70 to the controller C, and the controller C calculates the inclination angle of the center float 34. The controller C
Accordingly, when it is determined that the tilt angle of the center float 34 has been rotated beyond a certain range, the solenoid of the lift valve 86 is excited to expand and contract the lift cylinder 28,
The planting section 15 is moved up and down to a predetermined position. When the planting section 15 is moved up and down, and the angle sensor 71 detects that the center float 34 has returned to the original inclination angle, the solenoid of the elevating valve 86 is excited, and the driving of the elevating cylinder 28 is stopped. Elevation control for stopping the elevation of the planting section 15 at a predetermined position is performed. Note that the planting section 15 is controlled by the angle sensor 120 disposed on the link mechanism 27 described above.
, The height of the planting section 15 can be confirmed, and the driving of the lifting cylinder 28 can be stopped.

FIGS. 18 and 19 show a second embodiment of another embodiment for detecting the inclination angle of the center float 34. FIG.
This will be described with reference to FIG. In the second embodiment, the front of the center float 34 is suspended from the front end of the link 95 via a sensor link 98. An upper portion of a stay 73 is pivotally supported at a rear portion of the link 95, and a position detecting sensor 74 is fixed to a lower portion of the stay 73.

The position detecting sensor 74 comprises a sensing rod 74a and a storage portion 74b for storing the sensing rod 74a in an extendable and retractable manner. A spring 75 is wound between the bottom surface of the housing 74b and the tip of the sensing rod 74a to urge the lower part of the sensing rod 74a downward. The position detecting sensor 74
Detects the amount of movement of the object with which the tip of the sensing rod 74a contacts by detecting the amount of expansion and contraction of the sensing rod 74a. Further, a thread groove is formed in the outer peripheral surface of the lower part of the storage portion 74b, and a predetermined position in the thread groove is engaged with the stay 73, and the position detecting sensor 74 is provided.
The vertical position of is adjusted.

The stay 73 includes a position detecting sensor 7.
When fixing the sensor rod 4, the lower end of the sensing rod 74 a contacts the upper surface of the center float 34, and the sensing rod 7
A position detecting sensor 74 is provided at a position where the position 4a is slightly contracted.
Is fixed to the stay 73. When the front part of the center float 34 is rotated, the position detecting sensor 74 is rotated.
The inclination angle of the center float 34 is determined by the expansion and contraction of the sensing rod 74a. If it is determined that the tilt angle has been rotated beyond a certain range, the solenoid of the elevating valve 86 is excited to extend and retract the elevating cylinder 28, thereby moving the planting portion 15 up and down to a predetermined position.

A third embodiment of another embodiment for detecting the inclination angle of the center float 34 will be described with reference to FIG. In the third embodiment, the front wheels 6 and 6 and the rear wheels 8
-A center float 34 'is disposed at the center of the abdomen of the traveling vehicle between the position 8 and the left and right. The support arm 76 projects substantially below the front and rear part of the body frame 3, and a pivot arm 77 is pivotally supported below the support arm 76. On the other hand, a bracket 90 is erected at the center of gravity of the center float 34 in the front-rear direction, and a fulcrum shaft 93 on the upper portion of the bracket 90 is fixed. The pivot arm 77 is pivotally supported by the fulcrum shaft 93.

An angle sensor 123 composed of a potentiometer or the like is provided below the support arm 76, and a sensing arm 123a of the angle sensor 123 is connected to a long hole provided in the rotating arm 77.

When the center float 34 is moved up and down due to irregularities on the surface of the field, the turning arm 77 turns, and the angle sensor 123 detects the turning amount of the turning arm 77. Center float 34 '
And the flying height. When the amount of rotation exceeds a certain range, that is, when the floating amount of the center float 34 'is rotated from a certain range, after a certain time, the solenoid of the elevating valve 86 is excited to expand and contract the elevating cylinder 28, The planting section 15 is moved up and down to a predetermined position.

By arranging the center float 34 on the abdomen of the body, it is possible to detect irregularities in the field scene at a position in front of the planting section 15, and then drive the elevating cylinder 28 after detecting the irregularities. By doing so, it is possible to eliminate a time lag until the planting section 15 is moved up and down to an appropriate position.
Furthermore, it is possible to adopt a configuration in which the center float 34 is not provided among the plurality of floats provided in the planting section 15, and the weight of the planting section 15 can be reduced.

[0040]

As described above, the present invention has the following advantages. That is, as described in claim 1, the float is pivotally supported at the lower part of the planting portion and the front portion of the float is elastically supported by the elastic member. The field scene has been leveled by. The float inclines only the unevenness of the field scene necessary for raising and lowering the planting part, accurately detects the unevenness of the field scene, can raise and lower the planting part, and malfunctions the elevating mechanism. Without the need for accurate planting work.

Further, the front part of the float is elastically supported by an expandable member, the amount of expansion and contraction of the expandable member is detected by a sensor, and the planting portion is moved up and down in accordance with the amount of expansion and contraction. The unevenness amount of the field scene where the planting section is raised and lowered can be accurately detected, the detection accuracy is improved, and the planting operation can be performed accurately according to the field scene.

Further, as described in claim 3, a resistance is generated on the detecting member from the surface of the field during the planting operation, and the hardness of the surface of the field can be detected by detecting the resistance. The tilt angle of the float that activates the lifting mechanism can be automatically changed, eliminating the need for the operator to grasp the state of the field hardness, reducing the burden on the operator and, at the same time, the operator manually adjusting the sensitivity. Without this, the planting section can be raised and lowered appropriately in accordance with the condition of the field, and an accurate planting operation can be performed.

Further, as described in claim 4, the impeller is pivotally supported on the float, the outer peripheral end of the impeller is pushed into the field surface, and the impeller is rotated by receiving resistance from the field surface. It is possible to detect the hardness of the surface of the field by this rotation speed, and to change the inclination angle of the float for operating the elevating mechanism according to this rotation speed, so that the operator needs to grasp the state of the hardness of the field. This eliminates the burden on the operator, and at the same time allows the operator to appropriately raise and lower the planting section in accordance with the condition of the field without manually adjusting the sensitivity, thereby performing an accurate planting operation.

According to a fifth aspect of the present invention, the impeller is pivotally supported on the float, the outer peripheral end of the impeller is pushed into the field surface, and the impeller is rotated by receiving resistance from the field surface. Calculate the hardness of the surface of the field from the rotation speed, correct the calculated value by the value of the speed sensor that detects the vehicle speed,
The hardness of the surface of the field becomes accurate according to the traveling speed, and the change of the inclination angle of the float for operating the elevating mechanism can be performed more accurately. Therefore, it is not necessary for the operator to grasp the condition of the field hardness, and the burden on the operator is reduced, and at the same time, the operator appropriately raises and lowers the planting section according to the condition of the field without manually adjusting the sensitivity. Can be performed, and an accurate planting operation can be performed.

Further, as described in claim 6, two gears having different rotational torques are pivotally supported on the float, and the outer peripheral ends of the respective gears protrude into the field surface, and the gears receive resistance from the field surface and receive resistance. By rotating the gears, the hardness of the surface of the field can be detected from the difference between the rotation speeds of the two gears, and the inclination angle of the float for operating the elevating mechanism is changed according to the difference between the rotation speeds. By obviating the need to grasp the state of the hardness of the field, the burden on the operator is reduced, and at the same time, the operator can raise and lower the planting section appropriately according to the state of the field without manually adjusting the sensitivity, Accurate planting work can be performed.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the same.

FIG. 3 is a side view showing an elevating mechanism of the planting section.

FIG. 4 is a block diagram of a raising and lowering control mechanism of the planting section according to the present invention.

FIG. 5 is an explanatory diagram showing a sensitivity adjustment configuration.

FIG. 6 is a plan view of a center float provided with a detection member for detecting hardness in a field.

FIG. 7 is a partial sectional view of the same side view.

FIG. 8 is a plan view of a center float provided with a second embodiment of a detecting member for detecting hardness.

FIG. 9 is a side view of a gear as a detection member.

FIG. 10 is a sectional view of a gear.

FIG. 11 is a side view of a gear as a detection member.

FIG. 12 is a sectional view of a gear.

FIG. 13 is a block diagram of a sensitivity adjustment mechanism.

FIG. 14 is a side view of the first embodiment for detecting the inclination of the center float.

FIG. 15 is a rear sectional view of the same.

FIG. 16 is a side view of a third embodiment of a detecting member for detecting hardness.

FIG. 17 is a side view of a third embodiment for detecting the inclination of the center float.

FIG. 18 is a side view of the second embodiment for detecting the inclination of the center float.

FIG. 19 is a side view of the detection member of the second embodiment.

[Explanation of symbols]

 15 Planting part 28 Elevating cylinder (elevating mechanism) 34 (Center float) Float 70 Telescopic member 60 Impeller 63/64 Gear 113 Speed sensor

Claims (6)

[Claims] 1. A structure in which a planting portion is attached to a traveling vehicle so as to be able to move up and down, a float is pivotally supported below the planting portion, and the planting portion is moved up and down in accordance with a tilt angle of the float. A lifting and lowering control mechanism for a rice transplanter, characterized in that is is elastically supported by a telescopic member. 2. A structure in which a planting portion is attached to a traveling vehicle so as to be able to move up and down, a float is pivotally supported below the planting portion, and the planting portion is moved up and down in accordance with a tilt angle of the float. Characterized in that the elastic member is elastically supported by an expandable member, the amount of expansion and contraction of the expandable member is detected by a sensor, and the planting portion is raised and lowered according to the amount of expansion and contraction. 3. The planting part according to claim 1, wherein the planting part is attached to the traveling vehicle so as to be able to move up and down, the float is pivotally supported below the planting part, and the planting part is moved up and down according to the inclination angle of the float. A detection member is arranged at a lower portion, the detection member is made to protrude into the surface of the field, the hardness of the field surface is detected from the resistance of the surface of the field, and the float inclination angle for operating the elevating mechanism according to the detected value. The lifting and lowering control mechanism of the rice transplanter, characterized in that 4. A configuration in which a planting portion is attached to a traveling vehicle so as to be able to move up and down, a float is pivotally supported below the planting portion, and the planting portion is moved up and down in accordance with an inclination angle of the float. The float is tilted to pivotally support the car, to make the outer peripheral end of the impeller protrude into the field surface, to rotate the impeller by receiving resistance from the field surface, and to operate the elevating mechanism according to the number of rotations. An elevation control mechanism for rice transplanters characterized by changing the angle. 5. A vehicle speed is detected in a configuration in which a planting portion is attached to a traveling vehicle so as to be able to move up and down, a float is pivotally supported at a lower portion of the planting portion, and the planting portion is moved up and down according to a tilt angle of the float. Arrange a speed sensor, pivot the impeller to the float,
The outer peripheral end of the impeller protrudes into the field surface, the impeller is rotated by receiving resistance from the field surface, and the inclination angle of the float for operating the elevating mechanism is adjusted to the rotation speed and the traveling speed of the impeller. A raising and lowering control mechanism for a rice transplanter, which has been changed accordingly. 6. A configuration in which a planting portion is mounted on a traveling vehicle so as to be able to move up and down, a float is pivotally supported at a lower portion of the planting portion, and the planting portion is moved up and down in accordance with a tilt angle of the float. Two gears with different torques are pivotally supported, the outer peripheral edge of each gear is pushed into the field surface, the gears are rotated by receiving resistance from the field surface, and the gears are raised and lowered according to the difference in the number of rotations of both gears A raising and lowering control mechanism for a rice transplanter, wherein a tilt angle of a float for operating the mechanism is changed.